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In July 2009, the Medical Advisory Secretariat (MAS) began work on Non-Invasive Cardiac Imaging Technologies for the Assessment of Myocardial Viability, an evidence-based review of the literature surrounding different cardiac imaging modalities to ensure that appropriate technologies are accessed by patients undergoing viability assessment. This project came about when the Health Services Branch at the Ministry of Health and Long-Term Care asked MAS to provide an evidentiary platform on effectiveness and cost-effectiveness of noninvasive cardiac imaging modalities.After an initial review of the strategy and consultation with experts, MAS identified five key non-invasive cardiac imaging technologies that can be used for the assessment of myocardial viability: positron emission tomography, cardiac magnetic resonance imaging, dobutamine echocardiography, and dobutamine echocardiography with contrast, and single photon emission computed tomography.A 2005 review conducted by MAS determined that positron emission tomography was more sensitivity than dobutamine echocardiography and single photon emission tomography and dominated the other imaging modalities from a cost-effective standpoint. However, there was inadequate evidence to compare positron emission tomography and cardiac magnetic resonance imaging. Thus, this report focuses on this comparison only. For both technologies, an economic analysis was also completed.A summary decision analytic model was then developed to encapsulate the data from each of these reports (available on the OHTAC and MAS website).The Non-Invasive Cardiac Imaging Technologies for the Assessment of Myocardial Viability is made up of the following reports, which can be publicly accessed at the MAS website at: www.health.gov.on.ca/mas or at www.health.gov.on.ca/english/providers/program/mas/mas_about.htmlPOSITRON EMISSION TOMOGRAPHY FOR THE ASSESSMENT OF MYOCARDIAL VIABILITY: An Evidence-Based AnalysisMAGNETIC RESONANCE IMAGING FOR THE ASSESSMENT OF MYOCARDIAL VIABILITY: An Evidence-Based Analysis OBJECTIVE: The objective of this analysis is to assess the effectiveness and cost-effectiveness of cardiovascular magnetic resonance imaging (cardiac MRI) for the assessment of myocardial viability. To evaluate the effectiveness of cardiac MRI viability imaging, the following outcomes were examined: the diagnostic accuracy in predicting functional recovery and the impact of cardiac MRI viability imaging on prognosis (mortality and other patient outcomes). CLINICAL NEED: CONDITION AND TARGET POPULATION LEFT VENTRICULAR SYSTOLIC DYSFUNCTION AND HEART FAILURE: Heart failure is a complex syndrome characterized by the heart's inability to maintain adequate blood circulation through the body leading to multiorgan abnormalities and, eventually, death. Patients with heart failure experience poor functional capacity, decreased quality of life, and increased risk of morbidity and mortality. In 2005, more than 71,000 Canadians died from cardiovascular disease, of which, 54% were due to ischemic heart disease. Left ventricular (LV) systolic dysfunction due to coronary artery disease (CAD) () is the primary cause of heart failure accounting for more than 70% of cases. The prevalence of heart failure was estimated at one percent of the Canadian population in 1989. Since then, the increase in the older population has undoubtedly resulted in a substantial increase in cases. Heart failure is associated with a poor prognosis: one-year mortality rates were 32.9% and 31.1% for men and women, respectively in Ontario between 1996 and 1997. TREATMENT OPTIONS: IN GENERAL, THERE ARE THREE OPTIONS FOR THE TREATMENT OF HEART FAILURE: medical treatment, heart transplantation, and revascularization for those with CAD as the underlying cause. Concerning medical treatment, despite recent advances, mortality remains high among treated patients, while, heart transplantation is affected by the limited availability of donor hearts and consequently has long waiting lists. The third option, revascularization, is used to restore the flow of blood to the heart via coronary artery bypass grafting (CABG) or, in some cases, through minimally invasive percutaneous coronary interventions (balloon angioplasty and stenting). Both methods, however, are associated with important perioperative risks including mortality, so it is essential to properly select patients for this procedure. MYOCARDIAL VIABILITY: Left ventricular dysfunction may be permanent, due to the formation of myocardial scar, or it may be reversible after revascularization. Reversible LV dysfunction occurs when the myocardium is viable but dysfunctional (reduced contractility). Since only patients with dysfunctional but viable myocardium benefit from revascularization, the identification and quantification of the extent of myocardial viability is an important part of the work-up of patients with heart failure when determining the most appropriate treatment path. Various non-invasive cardiac imaging modalities can be used to assess patients in whom determination of viability is an important clinical issue, specifically: dobutamine echocardiography (echo),stress echo with contrast,SPECT using either technetium or thallium,cardiac magnetic resonance imaging (cardiac MRI), andpositron emission tomography (PET). DOBUTAMINE ECHOCARDIOGRAPHY: Stress echocardiography can be used to detect viable myocardium. During the infusion of low dose dobutamine (5 - 10 microg/kg/min), an improvement of contractility in hypokinetic and akentic segments is indicative of the presence of viable myocardium. Alternatively, a low-high dose dobutamine protocol can be used in which a biphasic response characterized by improved contractile function during the low-dose infusion followed by a deterioration in contractility due to stress induced ischemia during the high dose dobutamine infusion (dobutamine dose up to 40 ug/kg/min) represents viable tissue. Newer techniques including echocardiography using contrast agents, harmonic imaging, and power doppler imaging may help to improve the diagnostic accuracy of echocardiographic assessment of myocardial viability. STRESS ECHOCARDIOGRAPHY WITH CONTRAST: Intravenous contrast agents, which are high molecular weight inert gas microbubbles that act like red blood cells in the vascular space, can be used during echocardiography to assess myocardial viability. These agents allow for the assessment of myocardial blood flow (perfusion) and contractile function (as described above), as well as the simultaneous assessment of perfusion to make it possible to distinguish between stunned and hibernating myocardium. SPECT: SPECT can be performed using thallium-201 (Tl-201), a potassium analogue, or technetium-99 m labelled tracers. When Tl-201 is injected intravenously into a patient, it is taken up by the myocardial cells through regional perfusion, and Tl-201 is retained in the cell due to sodium/potassium ATPase pumps in the myocyte membrane. The stress-redistribution-reinjection protocol involves three sets of images. The first two image sets (taken immediately after stress and then three to four hours after stress) identify perfusion defects that may represent scar tissue or viable tissue that is severely hypoperfused. The third set of images is taken a few minutes after the re-injection of Tl-201 and after the second set of images is completed. These re-injection images identify viable tissue if the defects exhibit significant fill-in (> 10% increase in tracer uptake) on the re-injection images. The other common Tl-201 viability imaging protocol, rest-redistribution, involves SPECT imaging performed at rest five minutes after Tl-201 is injected and again three to four hours later. Viable tissue is identified if the delayed images exhibit significant fill-in of defects identified in the initial scans (> 10% increase in uptake) or if defects are fixed but the tracer activity is greater than 50%. There are two technetium-99 m tracers: sestamibi (MIBI) and tetrofosmin. The uptake and retention of these tracers is dependent on regional perfusion and the integrity of cellular membranes. Viability is assessed using one set of images at rest and is defined by segments with tracer activity greater than 50%. CARDIAC POSITRON EMISSION TOMOGRAPHY: Positron emission tomography (PET) is a nuclear medicine technique used to image tissues based on the distinct ways in which normal and abnormal tissues metabolize positron-emitting radionuclides. Radionuclides are radioactive analogs of common physiological substrates such as sugars, amino acids, and free fatty acids that are used by the body. The only licensed radionuclide used in PET imaging for viability assessment is F-18 fluorodeoxyglucose (FDG). During a PET scan, the radionuclides are injected into the body and as they decay, they emit positively charged particles (positrons) that travel several millimetres into tissue and collide with orbiting electrons. This collision results in annihilation where the combined mass of the positron and electron is converted into energy in the form of two 511 keV gamma rays, which are then emitted in opposite directions (180 degrees) and captured by an external array of detector elements in the PET gantry. Computer software is then used to convert the radiation emission into images. The system is set up so that it only detects coincident gamma rays that arrive at the detectors within a predefined temporal window, while single photons arriving without a pair or outside the temporal window do not active the detector. This allows for increased spatial and contrast resolution. CARDIAC MAGNETIC RESONANCE IMAGING: Cardiac magnetic resonance imaging (cardiac MRI) is a non-invasive, x-ray free technique that uses a powerful magnetic field, radio frequency pulses, and a computer to produce detailed images of the structure and function of the heart. (ABSTRACT TRUNCATED)
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Literature review Epidemiology Hepatocellular carcinoma (HCC) is the sixth most common cause of cancer worldwide with an annual incidence of over 711,000 new cases, and the third most common cause of cancer death with an annual mortality of 679,000 patients. Most commonly HCC develops in cirrhosis, irrespective of the etiology. In the western world, chronic alcohol abuse and nonalcoholic stratohepatitis are about the as important etiologic factors for cirrhosis as chronic hepatitis c. In chronic hepatitis C it is estimated that about 20% of patients will eventually develop cirrhosis after 20-30 years of infection. Once cirrhosis is established, the annual risk of developing HCC is estimated to be between 3 and 4 %, largely irrespective of the etiology of cirrhosis. Diagnosis of HCC HCC is mostly asymptomatic in early stage disease. Without proper surveillance programs of cirrhotic patients, diagnosis is only established in advanced stage disease. The efficacy of surveillance by Ultrasound (and to a lesser extent by alpha-fetoprotein measurement) has been established in prospective trials in the west as well in the east. surveillance by experienced sonographers makes curative treatment possible treatment possible in up to 75% of patients,while there is no curative treatment without proper surveillance. Surveillance is recommended for the following groups of patients: Hepatitis B carriers Asian males > 40 years, Asian females >50 years, All cirrhotic hepatitis B carriers, Family history of HCC, Africans over age 20. For non-cirrhotic hepatitis B carriers not listed above the risk of HCC varies depending on the severity of the underlying liver disease, the Long-Term Comprehensive National Plan for Science, Technology and Innovation inflammatory activity. Patients with high HBV DNA concentrations and those with ongoing hepatic inflammatory activity remain at risk for HCC. Non-hepatitis B cirrhosis Hepatitis C, Alcoholic cirrhosis, Genetic hemochromatosis, Primary biliary cirrhosis. Although the following groups have an increased risk of HCC no recommendations for or against surveillance can be made because a lack of data precludes an assessment of whether surveillance would be beneficial - Alpha1-antitrypsin deficiency ,Non-alcoholic steatohepatitis, Autoimmune hepatitis. Once a lesion is detected by ultrasound, the diagnosis can be established radiologically in lesions with typical appearance above 1 cm in diameter. Biopsy is mandated only in cases with atypical presentation on imaging. Staging of HCC Staging of HCC can be done using several systems. currently, the most widely used staging system is the Barcelona Clinic Liver Cancer (BCLC) staging system , which takes the underlying liver disease, tumor characteristics, as well as the general performance status into account . This staging system is popular as it is directly linked to treatment, making treatment decisions easy. Advanced stage HCC: the current role of medical therapies In western countries, about 30 % of patients are identified with an HCC in BCLC stage 0 or A, either through surveillance or by chance. For those patients curative options can be applied, which currently involve only surgical or interventional treatments. However , curatively treated patients , except for those who underwent transplantation, will have a tumor recurrence in 70 to 80 % of cases within 5 years of therapy and will eventually progress to BCLC B or BCLC C stage disease. Another 20 % of patients are diagnosed at very advanced stages BCLC D, being either symptomatic from the decompensated cirrhosis (Child-Pugh C) or having an advanced tumor. Those patients have a very short survival, which cannot be influenced by any therapeutic intervention and are only eligible to receive best supportive care. Currently, the domain of medical therapies for HCC is in the setting of advanced stage BCLC C. Conventional chemotherapy of any kind has never shown any meaningful therapeutic benefit, particularly in overall survival in randomized controlled trials in adult patients and cannot be recommended for the treatment of HCC today. Conventional cisplatin-based chemotherapy, Technology and Innovation without doxorubicine only has a place in the treatment of childhood hepatoblastoma, which is a distinctly different disease entity. In hepatoblastoma cisplatin-based chemotherapy does improve survival and can even provide a cure in over 80% of patients when combined with resection. Medical treatment of HCC changed dramatically in 2007 , when the first data from the successful use of targeted agents in advanced stage HCC, in particular tyrosine kinase inhibitors, were presented. Up-regulated signaling through the mitogen-activated protein kinase (MAPK) intracellular signal transduction pathway plays a crucial role in the development of hepatocellular carcinoma , as does tumor angiogenesis .The MAPK pathway comprises Raf ,MAPK kinase (MEK ) and extracellular signal-regulated Kinase (ERK), and is a mediator of tumor proliferation, differentiation and survival. The identification of pivotal pathways, such as the MAPK cascade, led to the development of targeted treatments, such as Sorafenib. Sorafenib is an orally active multikinase inhibitor that inhibits cell surface tyrosine kinases, as well as downstream intracellular Raf kinases in the MAPK cascade. Sorafenib is widely available for the use in the treatment of advanced renal cell carcinoma and has been reviewed in this indication previously. Recently, Sorafenib was also approved in the US and the EU for use in the treatment of hepatocellular carcinoma, the first systemic drug to be approved in this indication. Indeed, current US treatment guidelines recommend Sorafenib as the first-lone treatment option in patients with unresectable HCC who are Child-Pugh class A. Receptor tyrosine Kinases inhibited by Sorafenib include vascular endothelial growth factor receptor (VEGFR)-1, VEGFR-2, VEGFR-3, Platelet-derived growth factor receptor (PDGFR)-B, cKIT, FMS-like tyrosine kinase 3 (FLT-3) and RET. Intracellular Raf serine/threonine kinase isoforms inhibited by Sorafenib include Raf-1(or C-Raf), wild -type B-Raf and Mutant B-Raf. These kinases are involved in tumor cell proliferation and tumor angiogenesis. In vitro, dose-dependent inhibition of cell proliferation was seen with Sorafenib in the human hepatocellular carcinoma cell lines PLC/PRF/5 and HepG2. Moreover, dose dependent induction of apoptosis was seen after Sorafenib exposure, as assessed by TUNEL (terminal deoxynucleotide transferase d-uridine triphosphate nick end labeling) staining. Inhibition by Sorafenib of the Raf/MEK/ERK signaling pathway in PCL/PRF/5 and HepG2 cells was shown by, among other things, the inhibition of MEK and ERK phosphorylation. Sorafenib demonstrated Protocol number: 1.0 dated 01Aug2013 Short title: HCC - Sorafenib study Confidential Page 14 The Long-Term Comprehensive National Plan for Science, Technology and Innovation dose-dependent antitumor activity in murine xenograft model of PCL/PRF/5 human hepatocellular carcinoma. Significant tumor growth inhibition of 49% and 78% was seen in mice receiving oral Sorafenib 10 or 30 mg/kg/day for 16 or 21 days ( both P 16 weeks and 48 (35.0%) had progressive disease (the remaining 32 patients [23.4%] were not available for independent review). With Sorafenib, the median time to progression was 4.2 months (investigator assessment) or 5.5 months (independent assessment), and the median overall survival duration was 9.2 months. Phase III trial The clinical efficacy of oral Sorafenib was examined in patients with advanced HCC in a randomized, double-blind, placebo-controlled, multi center, phase III trial (the SHARP study) (22). Inclusion criteria were histologically proven, advanced hepatocellular carcinoma, with at least one measurable untreated lesion, an ECOG performance status of 0-2, Child-Pugh class A and no prior systemic treatment . 902 patients were screened and 602 were randomized to receive oral Sorafenib 400 mg twice daily (n=299) or placebo (n=303). The median duration of treatment was 23 weeks in Sorafenib recipients and 19 weeks in placebo recipients. Prior to randomization, patients were stratified according to macroscopic vascular invasion and/or extrahepatic spread, ECOG performance status and Geographical region. In terms of baseline characteristics, mean patient age was 65.5 years; 87% of patients were male; 87.5% of patients were from Europe; 96.5% of patients were Child-Pugh class A; 54%, 38.5% and 7.5% of patients had an ECOG performance status of 0, 1, 2 at baseline; 17.5% and 82.5% of patients had Barcelona Clinic Liver Cancer Group stage B and C cancer; and 70% of patients had vascular invasion and/or extrahepatic spread . The primary endpoints were overall survival and time to symptomatic progression (defined as the time from randomization to a 4-point decline from baseline in patient response to the Functional Assessment Of Cancer Treatment Hepatobiliary Symptom index [FHSI-8] confirmed at next visit , deterioration to ECOG performance status 4, or death). The time to progression (assessed by independent central review) was a pre-specified secondary endpoint. Tumor response rates were assessed using Response Evaluation Criteria in Solid Tumors (RECIST). Analyses were conducted in the intent-to-treat (ITT) population (22). Sorafenib significantly improved survival in patients with advanced hepatocellular carcinoma in the SHARP trial (22). The median duration of survival was 10.7 months with Sorafenib and 7.9 months with placebo, yielding a hazard ratio (HR) of 0.69 (95% CI 0.55, 0.88; P = 0.00058). Following the second planned interim analysis, the SHARP study was terminated early on the basis of this survival result. At the time of study termination, there was no significant difference between Sorafenib and placebo recipients in the time to symptomatic progression (assessed using FHSI-8 criteria). The median time to progression (assessed by independent central review) was significantly longer in patients receiving Sorafenib than those receiving placebo (5.5 vs. 2.8 months), with an HR of 0.58(95% CI 0.44, 0.74; P Overall study design Screening and Pre-Treatment Period Investigator/ Co-Investigator/Study Coordinator • Medical history • Biopsy and review of pathology • Physical examination and vital signs • Review of previous or concurrent medications and procedures • Child-Pugh assessment • ECOG assessment • Lesion(s) measurement • Determination of study eligibility • Written, signed and date informed consent Laboratory investigations • Hematology: CBC, Differential • Serology: HBV, HCV, and HIV • The levels of the Bimarkers: c-KIT, Soluble VEGFR-2,-3. • Coagulation: platelets, PT, PTT, INR • Liver function tests • Serum pregnancy test (as appropriate) Radiological investigations • CT scan (or MRI) of the chest • CT scan (or MRI) of the abdomen • PET Scan Patient • Review of patient information leaflet Treatment period Baseline Visit - Day 1 Investigator/ Co-Investigator/Study Coordinator • Review of concomitant medications and therapies • Review of ECOG • Prescription of Sorafenib Patient • Start of the Sorafenib 6-8 weeks cycle Sorafenib Cycle Week 0-6/8 Laboratory investigations to be done on a weekly basis • Hematology: CBC, Differential • Serology: HBV, HCV, and HIV • Coagulation: platelets, PT, PTT, INR results of laboratory investigations on a weekly basis • See patients every other week Patient • Takes the appropriate dose of Sorafenib • Goes for blood test every week • Consult with the investigator/co-investigator every other week Visit after first Sorafenib cycle (Week 5 + 1 week) Investigator/ Co-Investigator/Study Coordinator • Physical examination • Review of concomitant medications and therapies • Child-Pugh re-assessment • ECOG re-assessment • Lesion(s) measurement • Recording of Adverse events Laboratory investigations • Hematology: CBC, Differential • Coagulation: platelets, PT, PTT, INR • Liver function tests Radiological investigations • CT scan (or MRI) of the abdomen Follow-up Visits (Every 3 months)* Investigator/ Co-Investigator/Study Coordinator • Physical examination • Review of concomitant medications and therapies • Child-Pugh re-assessment • ECOG re-assessment • Lesion(s) measurement • Recording of Adverse events Laboratory investigations • Hematology: CBC, Differential • Coagulation: platelets, PT, PTT, INR • The Bio-markers: c-KIT, VEGFR -2,-3 at week 12. • Liver function tests Radiological investigations • CT scan (or MRI) of the abdomen *The patient is going to be followed up in the basis of either stable disease or partial response or progression this based on radiological profession (which is assessed by RECIST). For those with progression other Biopsy will be taken and the tissue to be evaluated further.
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Mitoxantrone (Novantrone), a synthetic anthracenedione derivative, is an antineoplastic, immunomodulatory agent. Its presumed mechanism of action in patients with multiple sclerosis (MS) is via immunomodulatory mechanisms, although these remain to be fully elucidated. Intravenous mitoxantrone treatment improved neurological disability and delayed progression of MS in patients with worsening relapsing-remitting (RR) [also termed progressive-relapsing (PR) MS] or secondary-progressive (SP) disease. In a pivotal randomised, double-blind, multicentre trial, mitoxantrone 12 mg/m(2) administered once every 3 months for 2 years provided significant improvements in neurological disability ratings, including Kurtzke Expanded Disability Status Scale (EDSS), Ambulatory Index (AI) and Standardised Neurological Status (SNS) scores, compared with placebo. The drug also significantly reduced the mean number of corticosteroid-treated relapses and prolonged the time to the first treated relapse, with the beneficial effects on disease progression supported by magnetic resonance imaging. Post hoc analyses suggest that the benefits associated with mitoxantrone treatment may be sustained for at least 12 months after cessation of treatment, mean changes from baseline at 36 months in EDSS, AI and SNS scores of 0.10, 0.61 and 0.19, respectively, in the mitoxantrone group versus 0.46, 1.13 and 3.38 with placebo. Concomitant intravenous mitoxantrone 20mg plus intravenous methylprednisolone 1g once every month for 6 months was more effective than intravenous methylprednisolone monotherapy in preventing the development of new gadolinium-enhanced lesions in patients with very active RRMS or SPMS. The drug was generally well tolerated in patients with MS. Adverse events were generally mild to moderate in severity and usually resolved upon discontinuation of treatment or with appropriate pharmacotherapy. At the recommended dosage, mitoxantrone appears to have a low potential to cause cardiotoxicity. In conclusion, intravenous mitoxantrone reduces the relapse rate and slows progression of the disease in patients with worsening RRMS, PRMS or SPMS; thus providing a new option for the management of these patients. The drug was generally well tolerated at the recommended dosage, although potential cardiotoxicity limits the total cumulative dose to 140 mg/m(2). Further studies are warranted to determine which patients with worsening RRMS, PRMS or SPMS are most likely to benefit from mitoxantrone treatment and to more fully define the long-term safety and tolerability of mitoxantrone, including the use of concomitant cardioprotectants to extend the therapeutic lifespan of the drug. Pharmacodynamic Profile. Mitoxantrone, a synthetic anthracenedione derivative, is an established cytotoxic, antineoplastic agent. Its presumed mechanism of action in multiple sclerosis (MS) is immunosuppression. In antineoplastic studies, the drug showed several immunomodulatory effects, inducing macrophage-mediated suppression of B-cell, T-helper and T-cytotoxic lymphocyte function. Currently, the pharmacodynamic properties of mitoxantrone have not been investigated to any extent in patients with MS. In one study, 6 months' treatment with intravenous mitoxantrone generally had no effect on the distribution of cytokine-positive peripheral blood monocyte cells in patients with MS. In an animal model of the disease, mitoxantrone suppressed the development and progression of both actively and passively induced acute experimental allergic encephalomyelitis (EAE). It appeared to be 10-20 times more effective than cyclophosphamide in the suppression of EAE. Moreover, mitoxantrone approximately doubled the mean time to onset of EAE versus control animals (279 vs 148 days after immunisation; p < 0.00005). In vitro, mitoxantrone 10 and 100 micro g/L inhibited myelin degradation by leucocytes and peritoneal macrophages derived from mice with acute EAE by approximately 60% and 100%. Pharmacokinetic Profile. Currently, there are no published pharmacokinetic data for intravenous mitoxantrone in pitoxantrone in patients with MS, paediatric patients or in those with renal impairment. All studies, to date, have been in patients with cancer receiving a single, approximately 30-minute intravenous infusion of mitoxantrone 5-14 mg/m(2). The drug exhibits triexponential pharmacokinetics, with a rapid initial distribution (alpha) phase, an intermediate distribution (beta) phase and a much slower elimination (gamma) phase. The mean half-life of the alpha phase appears to be 6-12 minutes and that of the beta phase 1.1-3.1 hours. Mitoxantrone has a high affinity for tissue, with a volume of distribution of up to 2248 L/m(2). Mitoxantrone persists for prolonged periods in tissues and was detectable in autopsy tissue from patients who last received the drug up to 272 days before death. At concentrations of 10-10000 ng/mL, the drug was 70-80 % bound to plasma proteins in dogs. Elimination of mitoxantrone occurs predominantly through biliary excretion and may be impaired in patients with hepatic dysfunction or third space abnormalities (e.g. ascites). The mean terminal elimination half-life of mitoxantrone ranged from 23 hours to 215 hours. Renal clearance accounts for 10 % of the total clearance of the drug. Total clearance of mitoxantrone ranged from 13 to 34.2 L/h/m(2) and renal clearance from 0.9 to 2.7 L/h/m(2). The drug appears to have a low potential for interaction with other concomitantly administered agents. Therapeutic Efficacy. Intravenous mitoxantrone (infusion of > or = 5 minutes), either as monotherapy or in combination with intravenous methylprednisolone, delayed the progression of the disease in patients with secondary-progressive (SP) or worsening relapsing-remitting (RR) MS (the latter is also termed progressive-relapsing MS) in comparative, randomised, multicentre trials. In a double-blind, monotherapy trial (Mitoxantrone In Multiple Sclerosis [MIMS] trial), mitoxantrone 12 mg/m(2) (n = 60) once every 3 months for 2 years significantly improved neurological disability relative to placebo (n = 64), as assessed by changes in mean Kurtzke Expanded Disability Status Scale (EDSS) score, mean Ambulatory Index (AI) score and mean Standardised Neurological Status (SNS) score. The drug also significantly reduced the mean number of corticosteroid-treated relapses per patient and prolonged the time to the first treated relapse. A Wei-Lachin multivariate analysis of these five efficacy variables indicated that the global difference between the two treatment groups was 0.30 (p < 0.0001). Mitroxantrone was also more effective than placebo according to secondary endpoints in this study, with fewer mitoxantrone recipients experiencing a relapse, a deterioration of > or =1 EDSS point or a confirmed deterioration in EDSS score over a 3-month period. Mitoxantrone recipients also showed less deterioration in quality-of-life ratings and had fewer hospital admissions, whereas more placebo recipients had new gadolinium-enhanced lesions at study end (the latter parameter was assessed using magnetic resonance imaging [MRI] in a subgroup of 110 patients, including 40 patients who received an exploratory 5 mg/m(2) dose). Furthermore, post hoc analyses indicated that the beneficial effects of mitoxantrone treatment on EDSS, SNS and AI scores were sustained for at least 12 months after cessation of treatment, with mean changes from baseline at 36 months in EDSS, AI and SNS scores of 0.10, 0.61 and 0.19, respectively, in the mitoxantrone group versus 0.46, 1.13 and 3.38 with placebo. Preliminary data from a cost-minimisation analysis based on results from the MIMS trial indicated that approximately half of the cost of mitoxantrone was offset by cost savings in other areas associated with the treatment of MS (direct and indirect major costs), with a total annual incremental cost for mitoxantrone of dollar 1661 per patient. Combination therapy once-monthly with intravenous mitoxantrone 20mg plus intravenous methylprednisolone 1g was more effective than intravenous methylprednisolone 1g once every month in preventing the development of gadolinium-enhanced lesions in patients with very active RRMS or SPMS (double-blind assessment using MRI scans). After 6 months, significantly more combination therapy recipients had no new gadolinium-enhanced lesions (90.5% vs 31.3% with monotherapy; p < 0.001) [primary endpoint]. There were also significant reductions in both the mean number of new enhancing lesions and the total number of gadolinium-enhanced lesions in patients receiving combination therapy versus methylprednisolone monotherapy.Tolerability. Mitoxantrone was generally well tolerated in patients with MS. Treatment-emergent adverse events occurring significantly more frequently with mitoxantrone (12 mg/m(2) once every 3 months for 2 years) than placebo were nausea, alopecia, menstrual disorders, urinary tract infection, amenorrhoea, leucopenia and elevated gamma-glutamyltranspeptidase levels. Adverse events were usually mild to moderate in severity and generally resolved with discontinuation of treatment or when treated with appropriate pharmacotherapy. Eight percent of patients discontinued treatment in the mitoxantrone 12 mg/m(2) group due to an adverse event versus 3% of placebo recipients. The incidence of drug-related acute myelogenous leukaemia was very low (0.12%) in a cohort of 802 patients with MS receiving mitoxantrone. Evidence suggests that the risk of cardiotoxicity is low in patients with MS. After 1 year of monotherapy, 3.4% of mitoxantrone recipients had a reduction in left ventricular ejection fraction (LVEF) to < or =50% compared with 0% of placebo recipients; at the end of the second year, respective incidences were 1.9% and 2.9% (total cumulative dose of mitoxantrone per patient was 96 mg/m(2) after 2 years' treatment). (ABSTRACT TRUNCATED)
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Several essential oils contain pulegone and are used for flavoring foods, drinks, and dental products, as fragrance agents, and in herbal medicines. Pulegone was nominated for study by the National Institute of Environmental Health Sciences based on the potential for human exposure and the absence of carcinogenicity data. Male and female F344/N rats and B6C3F1 mice received pulegone (approximately 96% pure) by gavage for 2 weeks, 3 months, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, Escherichia coli, and mouse peripheral blood erythrocytes. 2-WEEK STUDY IN RATS: Groups of five male and five female rats were administered 0, 37.5, 75, 150, 300, or 600 mg pulegone/kg body weight in corn oil by gavage, 5 days per week for 16 days. All male rats and nearly all female rats in the 300 and 600 mg/kg groups died prior to the end of the study. All moribund sacrifices and early deaths were attributed to liver toxicity. Mean body weight gains of males administered 37.5 or 150 mg/kg were significantly less than that of the vehicle controls. Clinical findings in 300 and 600 mg/kg rats included nasal/eye discharge, thinness, lethargy, and ruffled fur. Liver and kidney weights of dosed groups of females were generally significantly greater than those of the vehicle control group. The incidences of necrosis and cytoplasmic vacuolization of the liver in 300 and 600 mg/kg males and females were significantly greater than those in the vehicle control groups. 2-WEEK STUDY IN MICE: Groups of five male and five female mice were administered 0, 18.75, 37.5, 75, 150, or 300 mg pulegone/kg body weight in corn oil by gavage, 5 days per week for 16 days. Four females and one male in the 300 mg/kg groups died by study day 5. All early deaths were attributed to liver toxicity. Mean body weights of the dosed groups were similar to those of the vehicle controls. Clinical findings were observed only in 300 mg/kg mice and included thinness, lethargy, and ruffled fur. Liver weights of 300 mg/kg males were significantly greater than those of the vehicle controls. The incidences of cytoplasmic vacuolization and diffuse fatty change in 300 mg/kg females and necrosis in 300 mg/kg males were significantly greater than those in the vehicle controls. 3-MONTH STUDY IN RATS: Groups of 10 male and 10 female rats were administered 0, 9.375, 18.75, 37.5, 75, or 150 mg pulegone/kg body weight in corn oil by gavage, 5 days per week for 14 weeks. All rats survived until the end of the study except for one female in the 150 mg/kg group that died on day 9. Mean body weights of 75 and 150 mg/kg males and 150 mg/kg females were significantly less than those of the vehicle controls. At the end of the study, there was a small dose-related decrease in the erythron, evidenced by decreases in the hematocrit and hemoglobin values and the erythrocyte counts. An apparent erythroid response to the decreased erythron was evidenced by increased reticulocyte counts. Reduced and oxidized glutathione levels were generally increased in 75 and 150 mg/kg males and in 37.5 mg/kg or greater females. Absolute and relative liver weights of 75 and 150 mg/kg females and relative liver weights of males administered 18.75 mg/kg or greater were significantly greater than those of the vehicle controls. The absolute kidney weight of 150 mg/kg females and the relative kidney weights of all dosed groups, except 9.375 mg/kg males, were significantly greater than those of the vehicle controls. Absolute and relative thymus weights of 150 mg/kg males and females and the absolute thymus weight of 75 mg/kg males were significantly less than those of the vehicle controls. In the kidney, there was hyaline glomerulopathy in 75 mg/kg males and 150 mg/kg males and females. The incidence of renal tubule protein casts was significantly increased in the 150 mg/kg females. In the liver, incidences of bile duct hyperplasia and hepatocyte hypertrophy in 75 and 150 mg/kg males and 150 mg/kg females, hepatocyte focal necrosis in 150 mg/kg males, and oval cell hyperplasia and periportal fibrosis in 150 mg/kg males and females were increased. Incidences of bone marrow hyperplasia in 37.5 mg/kg males and 75 and 150 mg/kg males and females, heart mineralization in 150 mg/kg males, glandular stomach mineralization in 75 and 150 mg/kg females, and cellular histiocytic infiltration in the lung and ovarian cyst in 150 mg/kg females were significantly increased. 3-MONTH STUDY IN MICE: Groups of 10 male and 10 female mice were administered 0, 9.375, 18.75, 37.5, 75, or 150 mg pulegone/kg body weight in corn oil by gavage, 5 days per week for 14 weeks. All mice survived to the end of the study. Mean body weights of dosed mice were similar to those of the vehicle controls. Reduced and oxidized glutathione levels were generally greater than vehicle control levels in 150 mg/kg males and in 75 and 150 mg/kg females. Liver weights of 150 mg/kg males and 75 and 150 mg/kg females were significantly greater than those of the vehicle controls. No histopathologic lesions were observed that could be attributed to the administration of pulegone. 2-YEAR STUDY IN RATS: Groups of 50 male and 50 female rats were administered 0, 18.75 (males only), 37.5, 75, or 150 (females only) mg pulegone/kg body weight in corn oil by gavage, 5 days per week for up to 104 weeks. Due to excessive morbidity and mortality, 75 mg/kg males and 150 mg/kg females were not administered pulegone after week 60 (stop-exposure); these groups were administered the corn oil vehicle until the end of the study. Survival of 37.5 mg/kg males was significantly less than that of the vehicle controls; only two 75 mg/kg stop-exposure males survived, and no 150 mg/kg stop-exposure females survived to the end of the study. Compared to those of the vehicle controls, mean body weights were less in 75 mg/kg stop-exposure males after week 13 and in 75 mg/kg and 150 mg/kg stop-exposure females after weeks 21 and 9, respectively. Clinical findings included thinness, lethargy, and ruffled fur in the 75 mg/kg stop-exposure males and 150 mg/kg stop-exposure females. The incidences of urinary bladder papilloma and of papilloma or carcinoma (combined) were significantly increased in 150 mg/kg stop-exposure females. In the kidney, incidences of hyaline glomerulopathy were significantly increased in 37.5 mg/kg and 75 mg/kg stop-exposure males and in all dosed groups of females. The severity of chronic progressive nephropathy was increased in 37.5 mg/kg and 75 mg/kg stop-exposure males and in 75 mg/kg and 150 mg/kg stop-exposure females; the incidences of nephropathy were significantly increased in 75 mg/kg and 150 mg/kg stop-exposure females. The incidence of renal cyst was significantly increased in 75 mg/kg stop-exposure males. In the liver, incidences of diffuse hepatocyte cellular alteration were significantly increased in 37.5 mg/kg and 75 mg/kg stop-exposure males and 75 mg/kg and 150 mg/kg stop-exposure females. There were significant increases in the incidences of other liver lesions including fatty change, bile duct cyst, hepatocyte necrosis, oval cell hyperplasia, bile duct hyperplasia, and portal fibrosis. In the nose, 37.5 mg/kg and 75 mg/kg stop-exposure males and all dosed groups of females had significantly increased incidences of olfactory epithelium degeneration. All dosed groups of females had significantly increased incidences of respiratory metaplasia of the olfactory epithelium and nasal inflammation. In the forestomach, incidences of inflammation and ulcer were significantly increased in 37.5 mg/kg and 75 mg/kg stop-exposure males, and incidences of epithelial hyperplasia and perforation were increased in 75 mg/kg stop-exposure males. In the glandular stomach, the incidence of inflammation was significantly increased in 75 mg/kg stop-exposure males. 2-YEAR STUDY IN MICE: Groups of 50 male and 50 female mice were administered 0, 37.5, 75, or 150 mg pulegone/kg body weight in corn oil by gavage, 5 days per week for 105 weeks. Survival of all dosed groups was similar to that of the vehicle controls. Mean body weights of 150 mg/kg males and females were less than those of the vehicle controls after weeks 25 and 33, respectively. The incidences of multiple hepatocellular adenoma were significantly increased in all dosed groups of males, and the incidences of hepatocellular adenoma (includes multiple) and hepatoblastoma (includes multiple) were significantly increased in the 75 mg/kg males. The combined incidences of hepatocellular adenoma, hepatocellular carcinoma, or hepatoblastoma occurred with positive trends and were significantly increased in 75 mg/kg males and 150 mg/kg females. The incidence of hepatocellular adenoma was significantly increased in 150 mg/kg females. The incidences of several nonneoplastic liver lesions were significantly increased, primarily in the 75 and 150 mg/kg groups. These nonneoplastic lesions included clear cell, eosinophilic, and mixed cell foci; focal fatty change; centrilobular hepatocyte hypertrophy; intravascular hepatocyte; necrosis; pigmentation; bile duct cyst and hyperplasia; and oval cell hyperplasia. In the kidney, incidences of hyaline glomerulopathy were significantly increased in all dosed groups of males and 75 and 150 mg/kg females. The incidence of mineralization was significantly increased in 150 mg/kg females, and the incidence of nephropathy in 150 mg/kg females and severity of nephropathy in 150 mg/kg males were increased. Incidences of congestion of the glomerulus were increased in 150 mg/kg males and females. The incidence of osteoma or osteosarcoma (combined) in all organs of 75 mg/kg females exceeded the historical control ranges. One 150 mg/kg male and one 75 mg/kg female had nasal osteoma; no nasal osteomas have been observed in historical control mice. (ABSTRACT TRUNCATED)
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Hexachlorocyclopentadiene is an intermediate used in the manufacture of flame retardants, resins, and chlorinated cyclodiene pesticides. Toxicology and carcinogenesis studies were conducted by exposing male and female F344/N rats and B6C3F1 mice to atmospheres containing hexachlorocyclopentadiene (approximately 98% pure) for 6 hours per day, 5 days per week, for 13 weeks or 2 years. A stop-exposure evaluation was conducted in male B6C3F1 mice to determine the influence of exposure level and exposure duration on the development of nonneoplastic lesions of the respiratory tract and on their regression or progression after exposure was stopped. Genetic toxicology studies were conducted in Salmonella typhimunum, cultured Chinese hamster ovary cells, Drosophila melanogaster, and mouse peripheral blood samples were analyzed for frequency of micronucleated normochromatic erythrocytes. 13-WEEK STUDY IN RATS: Groups of 10 male and 10 female rats were exposed to atmospheres containing 0, 0.04, 0.15, 0.4, 1, or 2 ppm (equivalent to 0, 0.45, 1.67, 4.46, 11.14, and 22.28 mg/m(3)) hexachlorocyclopentadiene. Additional rats were exposed to 0, 0.04, 0.4, or 2 ppm hexachlorocyclopentadiene and evaluated for differences in clinical pathology parameters. All rats in the 1 and 2 ppm groups died during the first 4 weeks of the study. The final mean body weight and mean body weight gain of males exposed to 0.4 ppm were significantly lower than those of the controls. Listlessness was observed in 2 ppm rats from week 1, in 1 ppm rats from week 2, and in 0.4 ppm rats during week 3. Rats exposed to 1 or 2 ppm also experienced respiratory distress. No chemical-related differences in hematology, clinical chemistry, or urinalysis parameters were observed in male or female rats. Absolute and relative lung weights of 0.4 ppm males were significantly greater than those of the controls. Inflammation (necrotizing, chronic, or suppurative) of the nose, larynx, trachea, and lung was observed in 0.4, 1, and 2 ppm males and females. Squamous metaplasia of the epithelial lining of the nose of 0.4 ppm males and 1 and 2 ppm males and females was also observed. 13-WEEK STUDY IN MICE: Groups of 10 male and 10 female mice were exposed to atmospheres containing 0, 0.04, 0.15, 0.4, 1, or 2 ppm (equivalent to 0, 0.45, 1.67, 4.46, 11.14, and 22.28 mg/m(3)) hexachlorocyclopentadiene. Additional mice were exposed to 0, 0.04, 0.4, or 2 ppm and evaluated for differences in clinical pathology parameters. All 2 ppm mice died during the first week of exposure. All 1 ppm mice died during the first 5 weeks of exposure. Five males and two females in the 0.4 ppm group died during the first 2 weeks of exposure. Deaths in the other groups were not related to hexachlorocyclopentadiene exposure. Final mean body weights of males exposed to 0.15 and 0.4 ppm and the body weight gain of 0.4 ppm males were significantly lower than those of the controls. Treatment-related clinical findings included listlessness in 0.4 and 1 ppm males and females. No chemical-related differences in hematology, clinical chemistry, or urinalysis parameters were observed in male or female mice. Necrosis or inflammation of the nose, larynx, trachea, or lung occurred in mice exposed to 0.4,1, and 2 ppm hexachlorocyclopentadiene. Squamous metaplasia of the larynx or trachea was observed in 0.15, 0.4, and 1 ppm males and in 0.4 and 1 ppm females. 2-YEAR STUDY IN RATS: Survival, Body Weights, Clinical Findings, and Urinalysis Groups of 60 male and 60 female rats were exposed to atmospheres containing 0, 0.01, 0.05, or 0.2 ppm (equivalent to 0, 0.11, 0.56, and 2.28 mg/m(3)) hexachlorocyclopentadiene. Survival rates and mean body weights of exposed rats were similar to those of the controls. No chemical-related clinical findings were observed in male or female rats during the 2-year study. No differences in urinalysis parameters at the 15-month interim evaluation could be attributed to exposure to hexachlorocyclopentadiene. Pathology Findings: No increases in neoplasm incidences could be attributed to hexachlorocyclorocyclopentadiene. Toxicity was limited to the respiratory tract and included an increase in the incidence of pigmentation of the respiratory epithelium of the nose, trachea, and the bronchi and bronchioles of the lung in both males and females. Exposure to hexachlorocyclopentadiene also caused an increase in the incidence of squamous metaplasia of the laryngeal epithelium of exposed females; the incidences in 0.01 and 0.2 ppm females were significantly greater than that of the controls. The severity of squamous metaplasia was minimal in all exposed and control females. 2-YEAR STUDY IN MICE: Survival, Body Weights, Clinical Findings, and Urinalysis Groups of 60 male and 60 female mice were exposed to atmospheres containing 0, 0.01, 0.05, or 0.2 ppm (equivalent to 0, 0.11, 0.56, and 2.28 mg/m(3)) hexachlorocyclopentadiene. The 2-year survival rate of female mice in the 0.2 ppm group was marginally lower than that of the controls due to a higher incidence of ovarian inflammation in 0.2 ppm females. Mean body weights of 0.2 ppm males (weeks 62 to 103) and females (throughout the study) were lower than those of the controls. No clinical findings in male or female mice were attributed to chemical exposure during the 2-year study. There were no chemical-related differences in urinalysis parameters at the 15-month interim evaluation. Pathology Findings: The site of toxicity of hexachlorocyclopentadiene exposure in mice in the 2-year study was the respiratory tract. Chemical-related pigmentation of the respiratory epithelium of the nose, trachea, and lung and suppurative inflammation of the nose were observed. No increased neoplasm incidences in males or females could be attributed to hexachlorocyclopentadiene exposure. STOP-EXPOSURE EVALUATION: Survival, Body Weights, and Clinical Findings Groups of male mice were exposed to atmospheres containing 0.2 ppm hexachlorocyclopentadiene for 33 or 66 weeks or 0.5 ppm for 26 or 42 weeks followed by exposure to air until the end of the study. Fifty male mice from each stop-exposure group were evaluated at 2 years. Two-year survival rates of stop exposure groups were similar to that of the controls. Final mean body weights of stop-exposure groups were similar to that of the controls. No chemical related clinical findings were observed. Pathology Findings: Nonneoplastic respiratory tract lesions similar to those observed in the core study were observed in males in the stop-exposure groups. Chemical-related pigmentation and inflammation of the respiratory epithelium were persistent as indicated by their presence in many male mice after recovery periods of 62 to 78 weeks, and the incidence and severity of the lesions were related to exposure concentration and duration. GENETIC TOXICOLOGY: Hexachlorocyclopentadiene was not mutagenic in Salmonella typhimurium strains TA98, TA100, TA1535, and TA1537 when tested with and without S9. Hexachlorocyclopentadiene did induce sister chromatid exchanges and chromosomal aberrations in cultured Chinese hamster ovary cells, with and without S9. No induction of sex-linked recessive lethal mutations was observed in male Drosophila melanogaster treated with hexachlorocyclopentadiene by feeding or injection, and no increase in the frequency of micronucleated erythrocytes was seen in male or female B6C3F1 mice exposed to hexachlorocyclopentadiene by inhalation for 13 weeks. CONCLUSIONS: Under the conditions of these 2-year studies, there was no evidence of carcinogenic activity of hexachlorocyclopentadiene in male or female F344/N rats or B6C3F1 mice exposed to 0.01, 0.05, or 0.2 ppm. Exposure of rats to hexachlorocyclopentadiene produced pigmentation of the respiratory epithelium of the nose, trachea (males), and bronchi and bronchioles of the lung. Squamous metaplasia of the laryngeal epithelium occurred in female rats exposed to hexachlorocyclopentadiene. Suppurative inflammation of the nose as well as pigmentation of the respiratory mucosal epithelium occurred in mice exposed to hexachlorocyclopentadiene. Synonyms: Perchlorocyclopentadiene, hexachloro-1,3-cyclopentadiene, HEX, HCPD, HCCP, HCCPD Trade Name: C-56-Graphlox
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Triamterene is a potassium-sparing diuretic used in the treatment of edema associated with congestive heart failure, cirrhosis of the liver, and other diseases in which edema may occur. Toxicity and carcinogenicity studies were conducted by administering triamterene (greater than 99% pure) in feed to groups of male and female F344/N rats and B6C3F1 mice for 15 days, 13 weeks, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium and Chinese hamster ovary cells. 15-day Studies: Groups of five male and five female rats were fed diets containing 0, 1,000, 3,000, 10,000, 30,000, or 60,000 ppm triamterene. The diets containing 10,000 ppm or more were unpalatable, and feed consumption by the 3,000 ppm groups was reduced. Rats exposed to 1,000 or 3,000 ppm triamterene received approximate doses of 80 or 60 mg/kg body weight per day (males) or 70 or 50 mg/kg per day (females). One male rat and two female rats receiving 3,000 ppm died during the second week of the study. The final mean body weights of 3,000 ppm male and female rats were significantly lower than those of controls. Rats in the 3,000 ppm groups had renal tubule regeneration and cytoplasmic vacuolization of the zona glomerulosa of the adrenal gland. Groups of five male and five female mice were fed diets containing 0, 300, 1,000, 3,000, 10,000, or 30,000 ppm triamterene, but the diets containing 10,000 or 30,000 ppm were unpalatable. All mice receiving 3,000 ppm died by day 6. Mice exposed to 300 or 1,000 ppm triamterene received approximate doses of 40 or 155 mg/kg body weight per day (males) or 45 or 170 mg/kg body weight per day (females). The final mean body weights of mice in the 300 and 1,000 ppm groups were similar to those of the controls. Renal tubule degeneration and necrosis were observed in the kidney of 3,000 ppm mice. 13-Week Studies: Groups of 10 male and 10 female rats were fed diets containing 0, 150, 300, 600, 1,200, or 2,400 ppm triamterene. All rats receiving 2,400 ppm died before the end of the study; all other rats survived to the end of the study. Rats exposed to 150, 300, 600, or 1,200 ppm triamterene received approximate doses of 10, 20, 40, or 70 mg/kg body weight per day (males) or 10, 20, 40, or 80 mg/kg per day (females). Body weight gains and final mean body weights of rats in the 1,200 ppm groups were significantly lower than those of controls. There were no biologically significant differences in hematologic, clinical chemistry, or urinalysis parameters among exposed and control rats. Calculi were observed in the renal pelvis of four male rats in the 1,200 ppm group. Chemical-related lesions were observed in the kidney and adrenal gland of rats in the 1,200 and 2,400 ppm groups. These consisted of degeneration and regeneration of the renal tubule epithelium and cytoplasmic vacuolization of cells of the zona glomerulosa of the adrenal cortex. Depletion of hematopoietic cells from the bone marrow and of lymphocytes from the spleen and thymus of rats in the 2,400 ppm groups may have been related to debilitation and reduced feed consumption rather than chemical exposure. Groups of 10 male and 10 female mice were fed diets containing 0, 100, 200, 400, 800, or 1,600 ppm triamterene. All mice receiving 1,600 ppm, one 800 ppm female, one 200 ppm male, and four 100 ppm males died before the end of the study. Mice exposed to 100, 200, 400, or 800 ppm triamterene received approximate doses of 15, 25, 50, or 90 mg/kg body weight per day (males) or 15, 25, 50, or 115 mg/kg per day (females). The body weight gain and final mean body weight of male mice receiving 800 ppm were significantly lower than those of the controls. The total leukocyte and lymphocyte counts of males receiving 800 ppm and of females receiving 100, 400, or 800 ppm were significantly lower than those of controls. No other differences in hematologic, clinical chemistry, or urinalysis parameters were considered to be biologically significant. Necrosis of Lymphocytes was observed in the lymph node, spleen, and thymus of mice in the 800 and 1,600 ppm groups groups. 2-Year Studies: The doses selected for the 2-year studies were based on lower body weights, mortality, and chemical-related lesions observed in exposed animals during the 13-week studies. Groups of 70 male and 70 female rats were fed diets containing 0, 150, 300, or 600 ppm triamterene and groups of 70 male and 70 female mice were fed diets containing 0, 100, 200, or 400 ppm. Ten animals from each group were included for interim evaluations at 3 and 15 months. Because of a dosing error involving the high-dose mice at week 40, a second study was conducted with groups of 60 male and 60 female mice fed diets containing 0 or 400 ppm triamterene. In the 2-year studies, rats exposed to 150, 300, or 600 ppm triamterene received approximately 5,10, or 25 mg/kg body weight per day (males) and 5, 15, or 30 mg/kg (females) and mice exposed to 100, 200, or 400 ppm received approximately 10, 25, or 45 mg/kg (males) and 15, 30, or 60 mg/kg (females) per day. 3-Month and 15-Month Interim Evaluations in the 2-Year Studies: There were no biologically significant differences in hematologic, clinical chemistry, or urinalysis parameters between exposed and control rats or mice at the 3- or 15-month interim evaluations. At necropsy, the mean body weights of exposed rats and mice were similar to those of the controls. There were no chemical-related lesions in exposed rats at 3 months or in exposed mice at 3 or 15 months. At the 15-month evaluation, basophilic, clear cell, and mixed cell foci of the liver occurred in exposed male rats. No chemical-related lesions were observed in female rats at 15 months. Survival, Body Weights, Clinical Findings, and Feed Consumption in the 2-Year Studies: Survival of exposed rats was similar to that of controls (males: 0 ppm, 25/47; 150 ppm, 25/50; 300 ppm, 19/50; 600 ppm, 27/50; females: 29/50, 34/50, 34/50, 29/50). The mean body weights of 600 ppm rats were consistently lower than, but within 5% of, those of controls after week 49. Feed consumption by male and female rats was similar among exposed and control groups throughout the studies. There were no clinical findings of toxicity. Survival of 400 ppm male mice in the first study was lower than that of controls because of the dosing accident at week 40. Survival of 100 and 200 ppm male mice and of all exposed groups of female mice in the first study and of exposed males and females in the second study was similar to controls (males: first study, 0 ppm, 47/50; 100 ppm, 45/50; 200 ppm, 46/50; 400 ppm, 46/60; second study, 0 ppm, 43/50; 400 ppm, 39/50; females: first study, 38/50; 43/50; 43/50; 43/60; second study, 40/50; 38/51). Mean body weights of exposed mice were similar to those of controls throughout the first study with one exception; in the week following the dosing error, the mean body weight of 400 ppm males was 16% lower than that of controls. In the second study, mean body weights of 400 ppm mice were slightly lower than those of controls during the final 8 weeks. Feed consumption by exposed mice was similar to that by controls throughout the studies. There were no clinical findings of toxicity in exposed mice. Neoplasms and Nonneoplastic Lesions in the 2-Year Studies: The incidences of mixed cell foci and focal hyperplasia of the liver were significantly increased in 300 and 600 ppm male rats, and the incidences of clear cell and mixed cell foci were significantly increased in 300 and 600 ppm female rats. Hepatocellular adenomas occurred in all groups of exposed male rats, but none occurred in controls; the incidence of hepatocellular adenoma in the 150 ppm males was significantly higher than that of controls (O ppm, 0/50; 150 ppm, 6/50; 300 ppm, 4/50; 600 ppm, 3/49). Hepatocellular adenomas were observed in two 600 ppm female rats, but not in the lower exposure groups or in controls. No hepatocellular carcinomas were seen in exposed or control rats. The incidences of nephropathy in exposed rats were similar to those of controls, but the average severity of the lesion was marginally increased in male rats receiving 300 ppm and in female rats receiving 600 ppm (males: 47/50, 2.4; 49/50, 2.7; 50/50, 3.0; 49/50, 2.8; females: 38/50, 1.1; 45/50, 1.2; 45/50, 1.3; 45/50, 1.4). Although in the first study the incidences of hepatocellular adenoma in exposed male mice were similar to that of controls, the incidences of multiple adenomas were greater in the exposed groups, and the incidence of hepatocellular carcinoma in the 400 ppm group was marginally greater (hepatocellular adenoma: 0 ppm, 17/50; 100 ppm, 22/50; 200 ppm, 19/50; 400 ppm, 20/60; hepatocellular carcinoma: 5/50; 7/50; 3/50; 13/60). In the second study, the incidence of hepatocellular adenoma in the 400 ppm males was significantly higher than that of controls (hepatocellular adenoma: 0 ppm, 21/50; 400 ppm, 36/50; hepatocellular carcinoma: 9/50; 11/50). The incidences of hepatocellular adenoma in exposed female mice in the first and second studies were significantly greater than those of controls (hepatocellular adenoma, first study: 10/50; 22/50; 23/50; 36/60; second study: 7/50; 28/51). The incidences of multiple adenoma were also increased in the exposed groups. Although the incidences of hepatocellular carcinoma were similar among exposed and control female mice in the first study, the incidence of hepatocellular carcinoma in the 400 ppm females in the second study was marginally greater than that of controls (hepatocellular carcinoma, first study: 4/50; 4/50; 3/50; 8/60; second study: 5/50; 11/50). In both studies, hepatocellular foci (basophilic, eosinophilic, clear cell, or mixed cell) also occurred more frequently in exposed female mice than in controls. The incidences of thyroid gland follicular cell hyperplasia in the 200 and 400 ppm males and in all exposed groups of females were significantly greater than those of controls in the first study. These findings were confirmed in the second study (follicular cell hyperplasia: males, first study, 3/50, 8/50, 16/50, 20/60; second study, 0/50,16/50; females, first study, 4/49,17/49,18/50, 28/60; second study, 9/50, 32/51). The incidences of follicular cell neoplasms were similar among exposed and control mice in both studies. The incidences (28/50, 36/50, 43/50, 49/60) and average severity (0.56, 0.80, 1.00, 1.07) of nephropathy were marginally higher in exposed female mice than in controls in the first study. In the second study, the differences in incidence (15/50, 21/50) and severity (0.38, 0.55) were not as great. It is uncertain if these increases were related to the ingestion of triamterene. The incidences and severity of nephropathy were similar among exposed and control male mice in both studies. Genetic Toxicology: Triamterene was not mutagenic in Salmonella typhimurium strains TA98, TA100, TA1535, or TA1537 with or without exogenous metabolic activation (S9). It did not induce chromosomal aberrations in Chinese hamster ovary cells, with or without S9. Positive results were obtained for induction of sister chromatid exchanges in Chinese hamster ovary cells with and without S9. Conclusions: Under the conditions of these 2-year feed studies, there was equivocal evidence of carcinogenic activity of triamterene in male F344/N rats based on a marginal increase in the incidence of hepatocellular adenoma. There was no evidence of carcinogenic activity of triamterene in female F344/N rats administered 150, 300, or 600 ppm. There was some evidence of carcinogenic activity of triamterene in male B6C3F1 mice based on a marginal increase in the incidence of hepatocellular carcinoma in the first study and a significantly increased incidence of hepatocellular adenoma in the second study. There was some evidence of carcinogenic activity of triamterene in female B6C3F1 mice based on significantly increased incidences of hepatocellular adenoma and of adenoma and carcinoma (combined). Exposure to triamterene was associated with an increased incidence of hepatocellular foci, primarily mixed cell type, and an increase in the severity of nephropathy in female rats. In mice, exposure to triamterene was associated with an increased incidence of hepatocellular foci in females and an increased incidence of thyroid gland follicular cell hyperplasia in males and females. Synonyms: 6-Phenyl-2,4,7-pteridinetnamine; 6-phenyl-2,4,7-triaminopteridine; 2,4,7-triamino-6-phenypteridine; ademin; pterofen; pterophane; NSC-77625; SKF 8542 Trade names: Dyrenium, Dyazide, Dyren, Dytac, Jatropur, Maxzide, Noridyl, Triteren, Teriam, Urocaudal
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Rituximab is an anti-CD20 monoclonal antibody that has demonstrated efficacy in patients with various lymphoid malignancies, including indolent and aggressive forms of B-cell non-Hodgkin's lymphoma (NHL) and B-cell chronic lymphocytic leukaemia (CLL). While the optimal use of the drug in many clinical settings has yet to be clarified, two pivotal trials have established rituximab as a viable treatment option in patients with relapsed or refractory indolent NHL, and as a standard first-line treatment option when combined with cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) chemotherapy in elderly patients with diffuse large B-cell lymphoma (the most common type of aggressive NHL). The former was a noncomparative trial in relapsed indolent NHL (follicular and small lymphocytic subtypes) with clinical responses achieved in about half of patients treated with rituximab 375 mg/m(2) intravenously once weekly for 4 weeks, which was similar to some of the most encouraging results reported with traditional chemotherapeutic agents. The latter was a randomised comparison of eight cycles of CHOP plus rituximab 375 mg/m(2) intravenously (one dose per cycle) versus CHOP alone in previously untreated elderly patients (60 to 80 years of age) with diffuse large B-cell lymphoma. In this pivotal trial, 2-year event-free and overall survival were significantly higher with rituximab plus CHOP, and there was no increase in clinically significant adverse effects compared with CHOP alone. Treatment with rituximab is generally well tolerated, particularly in terms of adverse haematological effects and serious or opportunistic infections relative to standard chemotherapy. Infusion-related reactions occur in the majority of patients treated with rituximab; these are usually mild to moderate flu-like symptoms that decrease in frequency with subsequent infusions. In approximately 10% of patients, however, severe infusion-related reactions develop (e.g. bronchospasm, hypotension). These reactions are usually reversible with appropriate interventions and supportive care but there have been rare reports of fatalities. CONCLUSIONS: Clinical trials with rituximab indicate that the drug has broad application to B-cell malignancies, although further clarification is needed to determine its optimal use in many of these clinical settings. Importantly, rituximab in combination with CHOP chemotherapy has emerged as a new treatment standard for previously untreated diffuse large B-cell lymphoma, at least in elderly patients. Compared with conventional chemotherapy, rituximab is associated with markedly reduced haematological events such as severe neutropenia, as well as associated infections. Rituximab may be particularly suitable for elderly patients or those with poor performance status, and its tolerability profile facilitates its use in combination with cytotoxic drugs. PHARMACODYNAMIC PROPERTIES: Rituximab is a mouse/human chimaeric IgG(1)-kappa monoclonal antibody that targets the CD20 antigen found on the surface of malignant and normal B lymphocytes. Although treatment with rituximab induces lymphopenia in most patients, typically lasting about 6 months, a full recovery of B lymphocytes in the peripheral blood is usually seen 9-12 months after therapy, as CD20 is not expressed on haematopoietic stem cells. CD20 is, however, expressed on >90% of B-cell non-Hodgkin's lymphomas (NHL) and to a lesser degree on B-cell chronic lymphocytic leukaemia (CLL) cells. Although not fully elucidated, the cytotoxic effects of rituximab on CD20-positive malignant B cells appears to involve complement-dependent cytotoxicity, complement-dependent cellular cytotoxicity, antibody-dependent cellular cytotoxicity and induction of apoptosis. In addition, in vitro data indicate that rituximab sensitises tumour cells to the effects of conventional chemotherapeutic drugs. PHARMACOKINETIC PROPERTIES: Serum rituximab concentrations increased in proportion to dose across a wide range of single- and multiple-dose intravenous regimens in patients with B-cell NHL. When administll NHL. When administered at a dose of 375 mg/m(2) once weekly for 4 weeks in a pivotal trial in patients with relapsed or refractory indolent B-cell NHL (follicular or small lymphocytic subtypes), peak serum concentrations essentially doubled from the first (239.1 mg/L) to the fourth (460.7 mg/L) infusion, while elimination half-life (t(1/2)) increased from 76.3 to 205.8 hours (3.2 to 8.6 days). The concomitant increase in serum rituximab concentrations and t(1/2) with each successive infusion may be due, at least in part, to the elimination of circulating CD20-positive B cells and reduction or saturation of CD20-binding sites after the initial infusions of rituximab. The pharmacokinetic properties of rituximab are also characterised by wide inter-individual variability, and serum drug concentrations that are correlated with clinical response. Although pharmacokinetic data are limited in patients with aggressive forms of NHL, such as diffuse large B-cell lymphoma, rituximab appears to have a similar pharmacokinetic profile in these patients to that in patients with indolent B-cell NHL. The pharmacokinetics of rituximab are also reported to be similar whether the drug is administered with or without cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) chemotherapy. THERAPEUTIC USE: A number of studies have demonstrated efficacy of intravenous rituximab in patients with various lymphoid malignancies of B-cell origin, including indolent (e.g. follicular lymphoma) and aggressive (e.g. diffuse large B-cell lymphoma) forms of NHL, and CLL, but the drug has not yet been approved for use in CLL, and approved indications in NHL vary between countries. In the US, for example, rituximab is available for the treatment of patients with low-grade or follicular, relapsed or refractory, CD20-positive B-cell NHL. In Europe, the drug has similar approval for relapsed or refractory follicular NHL as in the US, but has also been approved for use in combination with CHOP chemotherapy for the most common aggressive form of NHL (CD20-positive, diffuse large B-cell lymphoma). Rituximab was approved for these indications primarily on the basis of results from two pivotal trials. In Japan, rituximab has been approved for indolent B-cell NHL and mantle cell lymphoma (an aggressive form of B-cell NHL), primarily on the basis of results of a Japanese phase II trial. Indolent NHL: Results of several studies evaluating rituximab 375 mg/m(2) once weekly for 4 weeks in patients with indolent forms of B-cell NHL (primarily follicular and small lymphocytic lymphomas) showed objective response (OR) rates ranging from approximately 40-60% in those receiving the drug for relapsed or refractory indolent B-cell NHL, and slightly higher (50-70%) for those receiving rituximab as first-line therapy. In a pivotal trial in 166 patients with relapsed or refractory low-grade or follicular B-cell NHL, intent-to-treat (ITT) analysis showed an OR rate of 48%, and a projected median time to progression of 13 months. Encouraging data are also emerging on the use of rituximab in combination with chemotherapeutic agents (e.g. CHOP, fludarabine-containing regimens) or other drugs (e.g. interferon-alpha2a) in previously untreated patients with indolent forms of B-cell NHL (primarily follicular and small lymphocytic subtypes). Rates for OR were consistently around 95%, with the majority being complete responses (CRs). Follow-up data from a study in 40 patients with low-grade or follicular B-cell NHL treated with rituximab plus CHOP as first-line therapy showed that responses were durable with a progression-free survival and median duration of response >5 years.Bcl-2 gene rearrangement (t14;18) occurs in malignant cells in up to 85% of patients with follicular lymphoma, and minimal residual disease in peripheral blood and bone marrow can be monitored using polymerase chain reaction (PCR). In several studies assessing blood and/or bone marrow, rituximab has achieved molecular response (conversion from PCR-positive to PCR-negative bcl-2 status) in at least half of the patients. Aggressive NHL: Studies with rituximab as monotherapy in aggressive B-cell NHL, a potentially curable disorder, have generally been restricted to patients with relapsed or recurrent disease, since CHOP has traditionally been the standard first-line treatment regimen. However, promising results from phase II monotherapy studies prompted further clinical investigation of rituximab in conjunction with chemotherapy. Thus, most studies with rituximab in patients with aggressive forms of B-cell NHL have involved combination therapy, including a pivotal randomised trial comparing eight cycles of standard CHOP therapy plus rituximab 375 mg/m(2) (one dose per cycle) versus CHOP alone in 399 previously untreated elderly patients (60-80 years of age) with diffuse large B-cell lymphoma. Results of the pivotal trial showed a clear advantage for rituximab plus CHOP versus CHOP in terms of event-free survival (primary endpoint) at 2 years (57% vs 38%, p < 0.001). Overall survival at 2 years (70% vs 57%, p < 0.01) and CR rate (76% vs 63%, p < 0.01) were also higher with the rituximab-CHOP combination. Other, smaller trials with rituximab in combination with CHOP or other chemotherapeutic regimens, either as first-line therapy or for patients with relapsed or refractory aggressive B-cell NHL, have also shown promising results in terms of clinical response rates.CLL: In relatively small trials (n < 40) conducted primarily in patients with relapsed or refractory B-cell CLL, rituximab monotherapy (various regimens) achieved OR rates of 23-45%, with median duration of response ranging from approximately 3-10 months. (ABSTRACT TRUNCATED)
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Nickel oxide (NiO) "sinters" are used in stainless steel and alloy steel production. Nickel oxide was nominated by the National Cancer Institute to the NTP for testing because exposure to this form of nickel is prevalent in the nickel industry. Increased incidences of lung and nasal sinus cancers have occurred among workers in certain nickel refining facilities, and nickel oxide was studied as part of a class study of nickel compounds. Male and female F344/N rats and B6C3F1 mice were exposed to nickel oxide (high temperature, green nickel oxide; mass median diameter 2.2 +/- 2.6 &mgr;m; at least 99% pure) by inhalation for 16 days, 13 weeks, or 2 years. Genetic toxicology studies were conducted in peripheral blood of B6C3F1 mice exposed to nickel oxide for 13 weeks. 16-DAY STUDY IN RATS: Groups of five male and five female F344/N rats were exposed to 0, 1.2, 2.5, 5, 10, or 30 mg nickel oxide/m(3)(equivalent to 0, 0.9, 2.0, 3.9, 7.9, or 23.6 mg nickel/m(3)) by inhalation for 6 hours per day, 5 days per week for a total of 12 exposure days during a 16-day period. Additional groups of five male and five female rats were exposed to 0, 1.2, 5, or 10 mg/m(3) for tissue burden studies. All core study rats survived until the end of the study, final mean body weights of exposed male and female rats were similar to those of the controls, and there were no clinical findings related to nickel oxide exposure. Absolute and relative lung weights of male and female rats exposed to 10 or 30 mg/m(3) were significantly greater than those of the controls. Pigment particles in alveolar macrophages or within the alveolar spaces were observed in the lungs of exposed groups of males and females. Chronic-active inflammation and accumulation of macrophages in alveolar spaces of the lungs and hyperplasia in the respiratory tract lymph nodes were most severe in 10 and 30 mg/m(3) males and females. Hyperplasia of bronchial lymph nodes occurred in 30 mg/m(3) rats. Atrophy of the olfactory epithelium was observed in one male and one female exposed to 30 mg/m(3). The concentrations of nickel oxide in the lungs of exposed groups of rats were greater than those in the lungs of control groups (males, 42 to 267 mg nickel/g lung; females, 54 to 340 mg/g lung). 16-DAY STUDY IN MICE: Groups of five male and five female B6C3F1 mice were exposed to 0, 1.2, 2.5, 5, 10, or 30 mg nickel oxide/m(3) by inhalation for 6 hours per day, 5 days per week for a total of 12 exposure days during a 16-day period. Additional groups of five male and five female mice were exposed to 0, 1.2, 2.5, or 5 mg/m(3) for tissue burden studies. No exposure-related deaths occurred among core study mice, and final mean body weights of exposed male and female mice were similar to those of the controls. There were no chemical-related clinical findings. Pigment particles were present in the lungs of mice exposed to 2.5 mg/m(3) or greater. Accumulation of macrophages in alveolar spaces was observed in the lungs of 10 and 30 mg/m(3)males and females. The concentrations of nickel oxide in the lungs of exposed groups of mice were significantly greater than those in the lungs of control animals (males, 32 to 84 mg nickel/g lung; females, 31 to 71 mg/g lung). 13-WEEK STUDY IN RATS: Groups of 10 male and 10 female F344/N rats were exposed to 0, 0.6, 1.2, 2.5, 5, or 10 mg nickel oxide/m(3) (equivalent to 0, 0.4, 0.9, 2.0, 3.9, or 7.9 mg nickel/m(3)) by inhalation for 6 hours per day, 5 days per week for 13 weeks. Additional groups of 18 male and 18 female rats were exposed to 0, 0.6, 2.5, or 10 mg/m(3) for tissue burden studies. No exposure-related deaths occurred among core study rats, final mean body weights of exposed male and female rats were similar to those of the controls, and no clinical findings in any group were related to nickel oxide exposure. Lymphocyte, neutrophil, monocyte, and erythrocyte counts; hematocrit values; and hemoglobin and mean cell hemoglobin concentrations in exposed rats were minimally to mildly greater than those of the controls; these differences were most pronounced ironounced in females. Mean cell volumes in exposed rats were generally less than those in the controls. Absolute and relative lung weights of exposed groups of males and females were generally significantly greater than those of controls. Chemical-related nonneoplastic lesions were observed in the lungs of male and female rats exposed to concentrations of 2.5 mg/m(3) or higher, and the severity of these lesions generally increased with exposure concentration. Accumulation of alveolar macrophages, many of which contained black, granular pigment, was generally observed in all exposed groups of males and females, and increased incidences of inflammation occurred in males and females exposed to 2.5 mg/m(3) or higher. In addition, lymphoid hyperplasia and pigment occurred in the bronchial and mediastinal lymph nodes of 2.5, 5, and 10 mg/m(3) males and females. The concentration of nickel oxide in the lungs of 0.6, 2.5, and 10 mg/m(3)males was greater than in the lungs of controls at 4, 9, and 13 weeks, and nickel continued to accumulate in the lung at the end of the 13-week exposures (4 weeks, 33 to 263 mg nickel/g lung; 9 weeks, 53 to 400 mg/g lung; 13 weeks, 80 to 524 mg/g lung). 13-WEEK STUDY IN MICE: Groups of 10 male and 10 female B6C3F1 mice were exposed to 0, 0.6, 1.2, 2.5, 5, or 10 mg nickel oxide/m(3) by inhalation for 6 hours per day, 5 days per week for 13 weeks. Additional groups of six male and six female mice were exposed to 0, 0.6, 2.5, or 10 mg/m(3) for tissue burden studies. No exposure-related deaths occurred among core study animals, final mean body weights of exposed male and female mice were similar to those of the controls, and no clinical findings in any group were related to nickel oxide exposure. Hematocrit values and erythrocyte counts in 5 and 10 mg/m(3) females were minimally greater than those of the controls, as was the hemoglobin concentration in 5 mg/m(3) females. Absolute and relative lung weights of 10 mg/m(3) males and females were significantly greater than those of controls, and absolute and relative liver weights of 10 mg/m(3) males were significantly less than those of controls. Accumulation of alveolar macrophages, many of which contained pigment particles, occurred in all groups of mice exposed to nickel oxide. Inflammation (chronic active perivascular infiltrates or granulomatous) occurred in 2.5, 5, and 10 mg/m(3) males and females. In addition, lymphoid hyperplasia and pigment occurred in the bronchial lymph nodes of males and females exposed to 2.5 mg/m(3) or higher. The concentration of nickel in the lung was greater than that of controls in 0.6, 2.5, and 10 mg/m(3) males at 13 weeks (42 to 736 mg nickel/g lung). 2-YEAR STUDY IN RATS: Survival, Body Weights, Clinical Findings, and Hematology Groups of 65 male and 65 female F344/N rats were exposed to 0, 0.62, 1.25, or 2.5 mg nickel oxide/m(3) (equivalent to 0, 0.5, 1.0, or 2.0 mg nickel/m(3)) by inhalation for 6 hours per day, 5 days per week for 104 weeks. Survival of exposed male and female rats was similar to that of the controls. Mean body weights of 1.25 mg/m(3) females and 2.5 mg/m(3) males and females were slightly lower than those of the controls during the second year of the study. No chemical-related clinical findings were observed in male or female rats during the 2-year study. No chemical-related differences in hematology parameters were observed in male or female rats at the 15-month interim evaluation. Pathology Findings: Absolute and relative lung weights of 1.25 and 2.5 mg/m(3) males and females were significantly greater than those of the controls at 7 and 15 months. At 2 years, there were exposure-related increased incidences of alveolar/bronchiolar adenomas alveolar/bronchiolar adenoma or carcinoma (combined) in males and females. Incidences of atypical alveolar epithelial hyperplasia in the lungs generally increased with increasing exposure concentration in male and female rats. Chronic inflammation of the lung was observed in most exposed rats at 7 and 15 months and at 2 years; the incidences in exposed males and females at 2 years were significantly greater than those in the controls, and the severity of the inflammation increased in exposed groups. The incidences of pigmentation in the alveolus of exposed groups of males and females were significantly greater than those of the controls at 7 and 15 months and at 2 years. Pigmentation in the bronchial lymph nodes similar to that in the lungs was observed in all exposure groups with the exception of 0.62 mg/m(3)males and females at 7 months. Lymphoid hyperplasia was observed in the bronchial lymph nodes of 1.25 and 2.5 mg/m(3) males and females at 7 and 15 months, and the incidence at 2 years generally increased with exposure concentration. At 2 years, there was an exposure-related increase in the incidence of benign pheochromocytoma in males and females. The incidences of benign pheochromocytoma and adrenal medulla hyperplasia in 2.5 mg/m(3) females and the incidence of benign or malignant pheochromocytoma (combined) in 2.5 mg/m(3) males were significantly greater than those in the controls. Tissue Burden Analyses: Nickel concentrations in the lungs of exposed rats were greater than those in the controls at 7 and 15 months (7 months, 173 to 713 mg nickel/g lung; 15 months, 262 to 1,116 mg/g lung), and nickel concentrations increased with increasing exposure concentration and with time. 2-YEAR STUDY IN MICE: Survival, Body Weights, Clinical Findings, and Hematology Groups of 74 to 79 B6C3F1 mice were exposed to 0, 1.25, 2.5, or 5 mg nickel oxide/m(3) by inhalation for 6 hours per day, 5 days per week for 104 weeks. Survival of exposed male and female mice was similar to that of the controls. Mean body weights of 5 mg/m(3) females were slightly lower than those of the controls during the second year of the study. No chemical-related clinical findings were observed in male or female mice during the 2-year study. No chemical-related differences in hematology parameters were observed in male or female mice at the 15-month interim evaluation. Pathology Findings: At 2 years, the incidence of alveolar/bronchiolar adenoma in 2.5 mg/m(3) females was significantly greater than that of the controls, as was the incidence of alveolar/bronchiolar adenoma or carcinoma (combined) in 1.25 mg/m(3) females. Generally, incidences of chronic inflammation increased with exposure concentration in males and females at 7 and 15 months. Bronchialization of minimal severity in exposed animals and proteinosis were first observed at 15 months. At 2 years, the incidences of chronic inflammation, alveolar epithelial hyperplasia, and proteinosis in exposed groups of males and females were significantly greater than those of the controls. The severity of chronic inflammation increased with exposure concentration in females, and proteinosis was most severe in 5 mg/m(3) males and females. Pigment occurred in the lungs of nearly all exposed mice at 7 and 15 months and at 2 years, and the severity increased with exposure concentration. Lymphoid hyperplasia occurred in two animals after 7 months; at 15 months, lymphoid hyperplasia occurred in males exposed to 2.5 and 5 mg/m(3) and in all exposed groups of females. At 2 years, lymphoid hyperplasia occurred in some control animals, but this lesion was still observed more often in exposed males and females and the incidence increased with exposure concentration. Pigmentation was observed in the bronchial lymph nodes of exposed males and females at 7 and 15 months and in nearly all exposed animals at 2 years. Tissue Burden Analyses: Nickel concentrations in the lungs of exposed mice were significantly greater than those in the controls at 7 and 15 months (7 months, 162 to 1,034 mg nickel/g lung; 15 months, 331 to 2,258 mg/g lung), and nickel concentrations increased with increasing exposure concentration and with time. GENETIC TOXICOLOGY: No increase in the frequency of micronucleated normochromatic erythrocytes was observed in peripheral blood samples from male or female mice exposed to nickel oxide. CONCLUSIONS: Under the conditions of these 2-year inhalation studies, there was some evidence of carcinogenic activity of nickel oxide in male F344/N rats based on increased incidences of alveolar/bronchiolar adenoma or carcinoma (combined) and increased incidences of benign or malignant pheochromocytoma (combined) of the adrenal medulla. There was some evidence of carcinogenic activity of nickel oxide in female F344/N rats based on increased incidences of alveolar/bronchiolar adenoma or carcinoma (combined) and increased incidences of benign pheochromocytoma of the adrenal medulla. There was no evidence of carcinogenic activity of nickel oxide in male B6C3F1 mice exposed to 1.25, 2.5, or 5 mg/m(3). There was equivocal evidence of carcinogenic activity of nickel oxide in female B6C3F1 mice based on marginally increased incidences of alveolar/bronchiolar adenoma in 2.5 mg/m(3) females and of alveolar/bronchiolar adenoma or carcinoma (combined) in 1.25 mg/m(3) females. Exposure of rats to nickel oxide by inhalation for 2 years resulted in inflammation and pigmentation in the lung, lymphoid hyperplasia and pigmentation in the bronchial lymph nodes, and hyperplasia of the adrenal medulla (females). Exposure of mice to nickel oxide by inhalation for 2 years resulted in bronchialization, proteinosis, inflammation, and pigmentation in the lung and lymphoid hyperplasia and pigmentation in the bronchial lymph nodes. Synonyms: Bunsenite; C.I. 77777; green nickel oxide; mononickel oxide; nickel monoxide; nickel oxide sinter 75; nickel protoxide; nickel (II) oxide; nickel (T+) oxide; nickelous oxide
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Toxicology studies of pentachlorophenol, a biocide used primarily as a wood preservative, were conducted by feeding diets containing a technical-grade composite, Dowicide EC-7 (a technical grade formulation), or pure pentachlorophenol to groups of B6C3F1 mice for 30 days. These three grades plus another commercial grade of pentachlorophenol (DP-2) were used in 6-month studies. These studies were followed by 2-year carcinogenicity studies of technical-grade pentachlorophenol and of Dowicide EC-7 in feed. Genetic toxicology studies were conducted in Salmonella typhimurium and in Chinese hamster ovary (CHO) cells. Thirty-Day and Sixteen-Month Studies: Groups of 19 male mice and 5-15 female mice were fed diets containing 0, 20, 100, 500, 2,500, or 12,500 ppm technical-grade pentachlorophenol, Dowicide EC-7, or pure pentachlorophenol for 30 consecutive days. Necropsies and histopathologic examinations were performed on all animals. Selected organs were weighed. Supplemental analyses included hematology, serum chemistry, urinalysis, immunology, and hepatic enzyme induction. Compound-related deaths were observed at the highest dose (12,500 ppm) with all three materials and at 2,500 ppm with EC-7 and pure pentachlorophenol (males only). Decreases in body weight gain were also observed in the groups in which deaths occurred. Diffuse centrilobular cytomegaly, karyomegaly, nuclear atypia, degeneration, or necrosis of the liver were compound-related lesions observed in all groups that received pure pentachlorophenol, technical-grade pentachlorophenol, or EC-7 at 500 ppm and above. Serum enzymes associated with liver injury were increased. In the 6-month studies, groups of 10 male and 10 female mice were given diets containing the various grades of pentachlorophenol at the following dietary concentrations: 200, 600, or 1,800 ppm technical-grade pentachlorophenol; 200, 600, or 1,200 ppm DP-2 (not used in the 30-day studies); 200, 600, or 1,200 ppm EC-7; or 200, 500, or 1,500 ppm pure pentachlorophenol for 26-27 weeks. Common control groups of 10 male and 10 female mice were fed control diets. Additional groups of male mice were examined for behavioral, histopathologic, clinical pathology, biochemical, and immunologic effects. All mice exposed at the highest dose of technical-grade pentachlorophenol died, as did 2/10 male mice exposed at the highest dose of DP-2. No deaths were observed in mice exposed to EC-7 or pure pentachlorophenol. Markedly lower final body weights were observed in the high dose groups only (all grades of pentachlorophenol). No chemical-relatedclinical signs were observed at sublethal doses. No major behavioral changes were observed after 5 weeks' exposure, but increased motor activity and heightened startle responses were present at the end of the study in female mice exposed to all four grades of pentachlorophenol. All grades of pentachlorophenol caused increases in serum enzymes associated with liver injury. All grades of pentachlorophenol also resulted in a dose-related induction of aryl hydrocarbon hydroxylase and an increase in cytochrome P450. However, the technical grade was a more powerful inducer than the other grades of pentachlorophenol. Pure pentachlorophenol had no effect on humoral or cell-mediated immunity. However, DP-2 and particularly technical-grade pentachlorophenol depressed humoral immune function. A dose-related increase in liver weight was observed in mice exposed to all grades of pentachlorophenol. A dose-related increase in spleen weight was observed in male mice exposed to all grades of pentachlorophenol; a decrease in spleen weight was observed in female mice exposed to all grades of pentachlorophenol except pure. After 6 months' exposure, histopathologic examination consistently revealed effects in the liver and urinary bladder. The liver lesions were present at all doses with all four grades of pentachlorophenol but were less severe at comparable doses in the mice exposed to pure pentachlorophenol; they consisted of hepatocellular karyomegaly, cytomegaly, and degeneration. The changes in the urinary bladder consisted of a brown granular pigment in the cells of the surface epithelium. No inflammation or proliferative response was associated with the pigment. Based primarily on the liver lesions observed in the 6-month studies, diets chosen for the 2-year studies contained 0, 100, or 200 ppm technical-grade pentachlorophenol or 0, 100, 200, or 600 ppm EC-7, fed to groups of 50 male and 50 female mice. DP-2 and pure pentachlorophenol were not chosen for the 2-year studies because of economic considerations and because the clinicopathologic syndrome observed in the 6-month studies was similar to that observed with EC-7. Body Weights and Survival in the Two-Year Studies: Mean body weights of mice exposed to technical-grade pentachlorophenol and EC-7 were comparable to those of controls until weeks 36-82. Thereafter, a 4%-22% dose-related decrease was observed in the mid and high dose mice exposed to EC-7 and in high dose mice exposed totechnical-grade pentachlorophenol. Females were more affected than males. Feed consumption by exposed mice was similar to that by controls. The average daily doses of technical-grade pentachlorophenol were approximately 17-18 or 35 mg/kg compared with 17-18, 34-37, or 114-118 mg/kg of EC-7. Survival of mice did not appear to be affected by exposure to either technical-grade pentachlorophenol or EC-7 at the doses used in these studies. Neoplastic and Nonneoplastic Effects in the Two-Year Studies: The incidences of hepatocellular adenomas and carcinomas were increased (dose related) in male and female mice exposed to either technical-grade pentachlorophenol or EC-7, although the increase was less marked in females exposed to technical-grade pentachlorophenol (adenomas or carcinomas, combined: technical-grade: male-- control, 7/32, 22%; low dose, 26/47, 55%; high dose, 37/48, 77%; female--3/33, 9%; 9/49, 18%; 9/50, 18%; EC-7: male--control, 6/35, 17%; low dose, 19/48, 40%; mid dose, 21/48, 44%; high dose, 34/49, 69%; female-- 1/34, 3%; 4/50, 8%; 6/49, 12%; 31/48, 65%). The incidences of pheochromocytomas in male mice were significantly greater than those in controls for both technical-grade pentachlorophenol (0/31; 10/45, 22%; 23/45, 51%) and EC-7 (1/34, 3%; 4/48, 8%; 21/48, 44%; 45/49, 92%). These neoplasms were also increased in female mice exposed to EC-7 at the highest dose (0/35; 2/49, 4%; 2/46, 4%; 38/49, 78%) but not in those exposed to technical-grade pentachlorophenol (2/33, 6%; 2/48, 4%; 1/49, 2%). Hyperplasia of the adrenal medulla was observed at increased incidences in mice that received either technical-grade pentachlorophenol (male: 1/31; 10/45; female: 0/33; 4/48; 2/49) or EC-7 (male: 1/34; 19/48; 13/48; 1/49; female: 2/35; 1/49; 5/46; 17/49). The incidences of hemangiosarcomas in the spleen and/or liver were significantly greater than those in controls for high dose female mice that received technical-grade pentachlorophenol (0/35; 3/50, 6%; 6/50, 12%) or EC-7 (0/35; 1/50, 2%; 3/50, 6%; 8/49, 16%). Compound-related nonneoplastic lesions occurred in the liver, spleen, and nose in mice exposed to either technical-grade pentachlorophenol or EC-7. The lesions in the liver included dose-related increased incidences of clear cell foci, chronic active inflammation, pigmentation, necrosis, cytomegaly, proliferation of hematopoietic cells, and bile duct hyperplasia. Increased amounts of extramedullary hematopoiesis of the splenic red pulp were observed at increased incidences in dosed male and high dose female mice that received technical-grade pentachlorophenol (male: 5/30; 15/23; 18/46; female: 2/33; 4/13; 11/47). Acutefocal inflammation of the nasal mucosa and focal metaplasia of the olfactory epithelium were observed at increased incidences in high dose mice that received EC-7 (inflammation--male: 4/35; 1/13; 3/16; 47/49; female: 0/35; 0/14; 2/5; 46/48; focal metaplasia-- male: 2/35; 1/13; 2/16; 46/49; female: 1/35; 0/14; 2/5; 45/48) but not in mice exposed to technical-grade pentachlorophenol. Genetic Toxicology: Pentachlorophenol (91.6% pure; equivalent in purity to the technical-grade pentachlorophenol used in the toxicology studies) was not mutagenic in S. typhimurium strains TA98, TA100, TA1535, or TA1537 when tested in the presence or absence of exogenous metabolic activation (S9). In cytogenetic studies with cultured CHO cells, pentachlorophenol produced an increase in chromosomal aberrations in the presence but not the absence of S9 metabolic activation; conversely, sister chromatid exchanges (SCEs) were induced only in the absence of S9. Audit: The data, documents, and pathology materials from the 2-year studies of pentachlorophenol have been audited. The audit findings show that the conduct of the studies is documented adequately and support the data and results given in this Technical Report. Conclusions: Under the conditions of these 2-year feed studies, there was clear evidence of carcinogenic activity for male B6C3F1 mice fed diets containing technical-grade pentachlorophenol, as shown by increased incidences of adrenal medullary and hepatocellular neoplasms. There was some evidence of carcinogenic activity for female B6C3F1 mice exposed to technical-grade pentachlorophenol, as shown by increased incidences of hemangiosarcomas and hepatocellular neoplasms. There was clear evidence of carcinogenic activity for male B6C3F1 mice exposed to pentachlorophenol, EC-7, as shown by increased incidences of adrenal medullary and hepatocellular neoplasms. There was clear evidence of carcinogenic activity for female B6C3F1 mice exposed to pentachlorophenol, EC-7, as shown by increased incidences of adrenal medullary and hepatocellular neoplasms and hemangiosarcomas. Chemically related increased incidences of nonneoplastic lesions in mice of each sex included hepatocellular cytomegaly, necrosis, inflammation, pigmentation, and clear cell foci and intrahepatic bile duct hyperplasia. Synonyms or Common Names: chlorophen; PCP; penchlorol; penta; pentachlorofenol; pentachlorofenolo; pentachlorphenol; 2,3,4,5,6-pentachlorophenol Trade Names: Acutox; Chem-Penta; Chem-Tol; Cryptogil ol; Dowicide 7; Dowicide EC-7; Dow Pentachlorophenol DP-2 Antimicrobial; Durotox; EP 30; Fungifen; Fungol; Glazd Penta; Grundier Arbezol; Lauxtol; Lauxtol A; Liroprem; Moosuran; Pentacon; Penta-Kil; Pentasol; Penwar; Peratox; Permacide; Permagard; Permasan;Permatox; Priltox; Permite; Santophen; Santophen 20; Sinituho; Term-i-Trol; Thompson's Wood Fix; Weedone; Witophen P
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Triethanolamine is widely used as an ingredient in emulsifiers, thickeners, wetting agents, detergents, and alkalinizing agents in cosmetic products; as a chemical intermediate for anionic and nonionic surfactants and surface active agents in household cleaning agents, textiles, herbicides, pharmaceutical ointments, and other products; as a vulcanization accelerator in the manufacture of rubber; and in many other industrial applications. The National Cancer Institute nominated triethanolamine for study because of its widespread use in cosmetics and other consumer products, its high potential for worker exposure due to its many industrial uses, and its potential for conversion to the carcinogen N -nitrosodiethanolamine. Dermal application was chosen as the route of exposure to mimic the principal means of human exposure to triethanolamine and because considerable systemic exposure is achieved with this route. Male and female F344/N rats and B6C3F1 mice received triethanol amine (purity 98% or greater) by dermal application for 13 weeks or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, cultured Chinese hamster ovary cells, Drosophila melano gaster, and mouse peripheral blood erythrocytes. 13-WEEK STUDY IN RATS: Groups of 10 male and 10 female rats were topically administered 0, 125, 250, 500, or 1,000 mg triethanolamine per kilogram body weight in acetone or 2,000 mg/kg neat triethanolamine, 5 days per week, for 13 weeks. All rats survived to the end of the study. Final mean body weights and weight gains of males and females administered 2,000 mg/kg and the mean body weight gain of females administered 1,000 mg/kg were significantly less than those of the vehicle controls. Clinical observations included irritation, scaliness, and crustiness of the skin at the site of application for males and females. Males also had discoloration, and two males administered 2,000 mg/kg had ulceration at the site of application. Changes in clinical pathology parameters were minor and consistent with inflammation at the site of application. Kidney weights were generally greater in males and females administered 500, 1,000, or 2,000 mg/kg than in the vehicle controls. Microscopic lesions attributed to triethanolamine administration included acanthosis and inflammation at the site of application, nephropathy in females, and hypertrophy of the pituitary gland pars intermedia in males and females. These lesions generally occurred with dose-related increases in incidence and severity in males and females. 13-WEEK STUDY IN MICE: Groups of 10 male and 10 female mice were topically administered 0, 250, 500, 1,000, or 2,000 mg triethanolamine per kilogram body weight in acetone or 4,000 mg/kg neat triethanolamine, 5 days per week, for 13 weeks. All mice survived to the end of the study. The final mean body weight and weight gain of males in the 250 mg/kg group were less than those of the vehicle controls. Clinical findings were observed only in mice in the 4,000 mg/kg groups and included scaliness, irritation, and discoloration at the site of triethanolamine application for males and females and skin erosion at this site in one male. The absolute kidney and liver weights of males and females administered 4,000 mg/kg were greater than those of the vehicle controls; relative kidney weights of males administered 1,000 mg/kg or greater and females in all dosed groups were also greater than those of the vehicle controls. Microscopic examination of the skin of dosed mice indicated acanthosis and inflammation at the site of application. Acanthosis occurred in all dosed groups and in one vehicle control female; the severity increased with increasing dose in males and females. Inflammation was observed in males and females in the 4,000 mg/kg groups and in one female in the 2,000 mg/kg group. 2-YEAR STUDY IN RATS: Based on the presence of acanthosis and inflammation at the site of application at the higher doses in the 13-week study, triethanolamine doses selected for the 2-year study in rats were 32, 63, and 125 mg/kg for malesr males and 63, 125, and 250 mg/kg for females. Groups of 60 male and 60 female rats were topically administered triethanolamine in acetone 5 days per week for 103 weeks. Ten male and ten female rats from each group were evaluated at 15 months for organ weights and histopathology. Survival, Body Weights, Clinical Findings, and Organ Weights: The survival rate of females in the 250 mg/kg group was slightly less than that of the vehicle controls. The mean body weight of females administered 250 mg/kg ranged from 9% to 12% less than that of the vehicle controls between weeks 73 and 93. Male and female rats receiving triethanolamine had irritated skin at the site of application; in dosed females, the site of application also had a crusty appearance. The number of animals in which these findings were observed increased with increasing dose. At the 15-month interim evaluation, the absolute left and right kidney weights and relative right kidney weight of females administered 250 mg/kg were significantly greater than those of the vehicle controls. Pathology Findings: The incidence of acanthosis at the site of application in males administered 125 mg/kg and the incidences of acanthosis, inflammation, and ulceration in dosed females were greater than in the vehicle controls at the 15-month interim evaluation and at the end of the 2-year study. Males in the 125 mg/kg group also had greater incidences of inflammation and ulceration than the vehicle controls, and females receiving 125 or 250 mg/kg had greater incidences of epidermal erosion than the vehicle controls at 2 years. There were no skin neoplasms at or away from the site of application that were considered related to treatment with triethanolamine. At the end of the study, renal tubule adenomas were observed in seven dosed males and in one vehicle control female and one female in the 63 mg/kg group. One male in the 125 mg/kg group and one female in the 250 mg/kg group had renal tubule hyperplasia. Extended (step-section) evaluation of the kidneys of all male rats revealed additional renal tubule adenomas in one vehicle control male, one male in the 32 mg/kg group, two males in the 63 mg/kg group, and three males in the 125 mg/kg group (including one male from the 15-month interim evaluation). An oncocytoma was also identified in one male in the 32 mg/kg group. Hyperplasia was identified in eight additional vehicle control males and in 19 additional dosed males. The total incidences (combined standard and extended evaluations) of renal tubule adenoma in dosed male rats were slightly greater than the vehicle control incidence (vehicle control, 1/50; 32 mg/kg, 2/50; 63 mg/kg, 6/49; 125 mg/kg, 4/50). The total incidence of hyperplasia in dosed and vehicle control males was similar (9/50, 8/50, 7/49, 6/50). The severity of hyperplasia in males in the 32 and 125 mg/kg groups was greater than that in the vehicle controls. 2-YEAR STUDY IN MICE: Based on dose-related inflammation at the site of application in the 13-week study, triethanolamine doses selected for the 2-year study in mice were 200, 630, and 2,000 mg/kg for males and 100, 300, and 1,000 mg/kg for females. Groups of 60 male and 60 female mice were topically administered triethanolamine in acetone 5 days per week for 103 weeks. Ten male and ten female mice from each group were evaluated at 15 months for organ weights and histopathology. Survival, Body Weights, Clinical Findings, and Organ Weights: Survival rates of all dosed groups of males and females were similar to those of the vehicle controls. The mean body weight of males administered 2,000 mg/kg ranged from 8% to 10% less than that of the vehicle controls from week 69 through the end of the study. Clinical findings included irritation and discoloration of the skin at the site of application for most males in the 2,000 mg/kg group and a few females in the 1,000 mg/kg group; males administered 200 or 630 mg/kg also had skin irritation. At the 15-month interim evaluation, the right kidney weights of male mice that received 630 or 2,000 mg/kg and the left kidney weights of males that received 2,000 mg/kg were significantly greater than those of the vehicle controls. Pathology Findings: Acanthosis and inflammation of the skin were observed at the site of application in male and female mice at the 15-month interim evaluation and at the end of the 2-year study. In males in the 2,000 mg/kg group, the incidences of both lesions were significantly greater than those in the vehicle controls at both time points; however, the severities of acanthosis and inflammation did not increase with dose. At the end of the study, the incidence of inflammation in females in the 1,000 mg/kg group was significantly greater than that in the vehicle controls. One vehicle control male and two males in each of the 630 and 2,000 mg/kg groups had ulcers at the site of application. At the 15-month interim evaluation, hepatocellular carcinomas were observed in dosed and vehicle control males and hepatocellular adenomas in dosed and vehicle control males and females; however, the incidences were not dose related. Nonneoplastic lesions observed at 15 months included foci of cellular alteration in a few dosed males and females; eosinophilic foci were also observed in two vehicle control females. At the end of the 2-year study, females in the 1,000 mg/kg group had significantly greater incidences of hepatocellular adenoma and multiple adenomas and a greater combined incidence of hepatocellular adenoma and carcinoma than the vehicle controls (adenoma: vehicle control, 22/50; 100 mg/kg, 22/50; 300 mg/kg, 24/50; 1,000 mg/kg, 40/50; multiple adenomas: 11/50, 9/50, 13/50, 29/50; combined adenoma and carcinoma: 23/50, 26/50, 28/50, 41/50). Females in the 300 mg/kg group had significantly greater incidences of hepatocellular carcinoma (1/50, 4/50, 7/50, 5/50) and eosinophilic foci (9/50, 10/50, 18/50, 16/50) than the vehicle controls. Incidences of hepatocellular adenoma and multiple adenomas in males in the 2,000 mg/kg group were significantly greater than those in the vehicle controls (adenoma: vehicle control, 27/50; 200 mg/kg, 27/50; 630 mg/kg, 29/50; 2,000 mg/kg, 37/50; multiple adenomas: 17/50, 18/50, 17/50, 29/50). Three males in the 2,000 mg/kg group had hepatoblastomas, and males in this group also had significantly greater incidences of hepatocellular neoplasms (combined) (adenoma, carcinoma, and hepatoblastoma: 31/50, 34/50, 33/50, 42/50) and eosinophilic foci (10/50, 17/50, 11/50, 23/50) than the vehicle controls. Male mice had a pattern of nonneoplastic liver lesions along with silver-staining helical organisms within the liver which suggested an infection with Helicobacter hepaticus. With polymerase chain reaction-based assays and culture, the presence of an organism compatible with H. hepaticus was confirmed. An increased incidence of hepatocellular neoplasms in male mice has been shown to be associated with H. hepaticus infection when hepatitis is also present. Therefore, interpretation of the increased incidence of hepatocellular neoplasms in mice was confounded. GENETIC TOXICOLOGY: Triethanolamine was not mutagenic in any of the in vitro or in vivo short-term tests performed by the NTP. It did not induce mutations in Salmonella typhimurium, and no induction of sister chromatid exchanges or chromosomal aberrations in cultured Chinese hamster ovary cells exposed to triethanolamine was noted. These in vitro tests were conducted with and without S9 metabolic activation. Triethanolamine did not induce sex-linked recessive lethal mutations in germ cells of adult male Drosophila melanogaster exposed by feeding or injection. No increase in the frequency of micronucleated erythrocytes was observed in peripheral blood samples of male and female mice that received dermal applications of triethanolamine for 13 weeks. CONCLUSIONS: Under the conditions of these dermal studies, there was equivocal evidence of carcinogenic activity of triethanolamine in male F344/N rats based on a marginal increase in the incidence of renal tubule cell adenoma. There was no evidence of carcinogenic activity in female F344/N rats receiving 63, 125, or 250 mg triethanolamine per kilogram body weight. The study in male and female B6C3F1 mice was considered inadequate, because the presence of a Helicobacter hepaticus infection complicated inter pretation of the relationship between triethanolamine administration and liver neoplasms in these animals. Dosed rats and mice had varying degrees of acanthosis and inflammation, dosed rats had ulceration, and dosed female rats had epidermal erosion at the site of skin application. Synonyms: Nitrilo-2,2',2"-triethanol; 2,2',2"-nitrilotriethanol; 2,2',2"-nitrilotrisethanol; TEA; triaethanolamin-NG; triethanolamin; triethylolamine; tri(hydroxyethyl)amine; 2,2',2"-trihydroxytriethylamine; trihydroxytriethylamine; tris(hydroxyethyl)amine; tris(2-hydroxyethyl)amine; triethylolamine; trolamine Trade Names: Daltogen; Sterolamide; Thiofaco T-35
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Nitromethane is used as a rocket and engine fuel; as a synthesis intermediate for agricultural fumigants, biocides, and other products; as a solvent; and as an explosive in mining, oil-well drilling, and seismic exploration. It has been detected in air, in surface and drinking water, and in cigarette smoke. Nitromethane was studied because of the potential for widespread human exposure and because it is structurally related to the carcinogens 2-nitropropane and tetranitromethane. Male and female F344/N rats and B6C3F1 mice received nitromethane (purity 98% or greater) by inhalation for 16 days, 13 weeks, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, cultured Chinese hamster ovary cells, and peripheral blood erythrocytes of mice. 16-DAY STUDY IN RATS: Groups of five male and five female rats were exposed to 0, 94, 188, 375, 750, or 1,500 ppm nitromethane by inhalation, 6 hours per day, 5 days per week, for 16 days. All rats survived until the end of the study. The mean body weight gain of male rats in the 1,500 ppm group was slightly but significantly less than that of the controls; the final mean body weights and mean body weight gains of exposed females were similar to those of the controls. Clinical findings in all male and female rats in the 1,500 ppm groups included increased preening, rapid breathing, hyperactivity early in the study, and hypoactivity and loss of coordination in the hindlimbs near the end of the study. The relative liver weights of all exposed groups of male rats and the absolute and relative liver weights of females exposed to 375 ppm or greater were significantly greater than those of the controls. Minimal to mild degeneration of the olfactory epithelium was observed in the nose of males and females exposed to 375 ppm or greater. Sciatic nerve degeneration was present in all male and female rats exposed to 375 ppm or greater; rats exposed to 750 or 1,500 ppm also had reduced myelin around sciatic axons. 16-DAY STUDY IN MICE: Groups of five male and five female mice were exposed to 0, 94, 188, 375, 750, or 1,500 ppm nitromethane by inhalation, 6 hours per day, 5 days per week, for 16 days. All mice survived to the end of the study. The final mean body weights and weight gains of exposed males and females were similar to those of the controls. Clinical findings included hypoactivity and tachypnea in male and female mice in the 1,500 ppm groups. Absolute and relative liver weights of male mice in the 750 and 1,500 ppm groups and female mice in all exposed groups and the relative liver weight of males in the 375 ppm group were significantly greater than those of the controls. Degeneration of the olfactory epithelium of the nose was observed microscopically in all males and females exposed to 375 ppm or greater; this lesion was of minimal severity in males and minimal to mild severity in females. 13-WEEK STUDY IN RATS: Groups of 10 male and 10 female rats were exposed to 0, 94, 188, 375, 750, or 1,500 ppm nitromethane by inhalation, 6 hours per day, 5 days per week, for 13 weeks. All rats survived to the end of the study. The final mean body weight and weight gain of male rats in the 1,500 ppm group were significantly less than those of the controls. Clinical findings included hindlimb paralysis in rats in the 750 and 1,500 ppm groups. Inhalation exposure of rats to nitromethane resulted in an exposure concentration-dependent, microcytic, responsive anemia; anemia was most pronounced in males and females exposed to 375 ppm or greater. The presence of schistocytes, Heinz bodies, and spherocytes and increased mean cell hemoglobin concentration and methemoglobin concentration were evidence that a hemolytic process was occurring; this hemolytic process could have accounted, in part, for the anemia. Thrombocytosis accompanied the anemia and would be consistent with a reactive bone marrow or could have been due to the erroneous inclusion of small erythrocyte fragments as part of the platelet count. On day 23, transient decreases in serum triiodothyronine, thyroxine, and fr and free thyroxine were observed in male rats exposed to 375 ppm or greater and female rats exposed to 750 or 1,500 ppm. There was little or no pituitary response to the thyroid hormone decreases, as evidenced by the lack of significantly increased concentrations of thyroid-stimulating hormone in exposed rats. No biologically significant differences in organ weights were observed. The forelimb and hindlimb grip strengths of males in the 1,500 ppm group were significantly less than those of the controls. The hindlimb grip strengths of females in the 750 and 1,500 ppm groups were also significantly less than the control value. Minimal to mild hyperplasia of the bone marrow was observed microscopically in male rats in the 750 and 1,500 ppm groups and in females exposed to 188 ppm or greater. Nasal lesions in exposed males and females included olfactory epithelial degeneration in males and females exposed to 375 ppm or greater and in one female exposed to 188 ppm and respiratory epithelial hyaline droplets and goblet cell hyperplasia in males and females in the 750 and 1,500 ppm groups; the severity of nasal lesions in males and females was minimal to mild. Males and females exposed to 375 ppm or greater had minimal to mild degeneration of the sciatic nerve and the lumbar spinal cord. 13-WEEK STUDY IN MICE: Groups of 10 male and 10 female mice were exposed to 0, 94, 188, 375, 750, or 1,500 ppm nitromethane by inhalation, 6 hours per day, 5 days per week, for 13 weeks. All mice survived to the end of the study. The final mean body weights and weight gains of exposed mice were generally similar to those of the controls. There were no treatment-related clinical findings. The absolute right kidney weights of all groups of exposed male mice except the 1,500 ppm group and of females exposed to 188 ppm or greater and the relative right kidney weights of all groups of exposed males and of females in the 750 and 1,500 ppm groups were significantly greater than those of the controls. The absolute liver weight of male mice in the 750 ppm group and the relative liver weights of males exposed to 375 ppm or greater were significantly greater than those of the controls. Olfactory epithelial degeneration and respiratory epithelial hyaline droplets were observed microscopically in all male and female mice exposed to 375 ppm or greater. Degeneration also occurred in females in the 188 ppm group, and hyaline droplets occurred in females in the 94 and 188 ppm groups. The average severity of the nasal lesions ranged from minimal to mild in males. In females, the average severity of olfactory epithelial degeneration ranged from minimal to mild and the severity of respiratory epithelial hyaline droplets ranged from minimal to moderate. All males and nine females in the 1,500 ppm groups also had minimal extramedullary hematopoiesis of the spleen. 2-YEAR STUDY IN RATS: Groups of 50 male and 50 female rats were exposed to 0, 94, 188, or 375 ppm nitromethane by inhalation, 6 hours per day, 5 days per week, for 103 weeks. Survival,Body Weights, and Clinical Findings: There were no significant differences in survival rates between exposed and control male or female rats. The mean body weight of females in the 375 ppm group was slightly greater than that of the control group; the mean body weights of exposed males were generally similar to the mean body weight of the controls throughout the study. Clinical findings were consistent with incidences of mammary gland neoplasms in females exposed to 188 or 375 ppm; no hindlimb paralysis, as occurred in rats in the 13-week study, was observed in male or female rats in the 2-year study. Pathology Findings: The incidences of mammary gland fibroadenoma and fibroadenoma, adenoma, or carcinoma (combined) in female rats in the 188 and 375 ppm groups were significantly greater than those in the controls. Additionally, the incidences of mammary gland carcinoma in the 375 ppm group were significantly greater than those in the controls. 2-YEAR STUDY IN MICE: Groups of 50 male and 50 female mice were exposed to 0, 188, 375, or 750 ppm nitromethane by inhalation, 6 hours per day, 5 days per week, for 103 weeks. Survival,Body Weights, and ClinicalFindings The survival rate of females in the 750 ppm group was marginally greater than that of the controls. The mean body weights of exposed females were generally slightly greater than the mean body weights of the controls during the study but were generally similar to the mean body weight of the controls at the end of the study. The mean body weights of exposed males were similar to those of the controls throughout the study. Clinical findings included swelling around the eyes and exophthalmos in exposed males and females; these findings were coincident with harderian gland neoplasms. Pathology Findings: The incidences of harderian gland adenoma and adenoma or carcinoma (combined) in exposed mice increased with increasing exposure concentration and were significantly greater in males and females in the 375 and 750 ppm groups than those in the controls. The incidences of harderian gland carcinoma in males and females in the 375 and 750 ppm groups were also slightly greater than those in the controls. Female mice in the 188 and 750 ppm groups had significantly greater incidences of hepatocellular adenoma and hepatocellular adenoma or carcinoma (combined) than the controls. The incidences of liver eosinophilic focus increased with increasing exposure concentration, and the incidences in the 375 and 750 ppm groups were significantly greater than the control incidence. The incidences of alveolar/bronchiolar carcinoma in male mice in the 750 ppm group and female mice in the 375 ppm group were significantly greater than those in the controls. Females in the 750 ppm group also had a significantly greater incidence of alveolar/bronchiolar adenoma or carcinoma (combined) and a slightly greater incidence of alveolar/bronchiolar adenoma than the controls. Females in the 375 ppm group had a significantly greater incidence of cellular infiltration of histiocytes in the lung than the controls. The incidences of degeneration and metaplasia of the olfactory epithelium and hyaline degeneration of the respiratory epithelium were significantly greater in exposed male and female mice than those in the controls. Additionally, males in the 375 and 750 ppm groups had significantly greater incidences of inflammation of the nasolacrimal duct than did the controls. GENETIC TOXICOLOGY: Nitromethane was not mutagenic in any tests performed by the NTP. It did not induce mutations in Salmonella typhimurium, with or without S9 metabolic activation, and no induction of sister chromatid exchanges or chromosomal aberrations in cultured Chinese hamster ovary cells exposed to nitromethane was noted with or without S9. No increase in the frequency of micronucleated erythrocytes was observed in peripheral blood samples of male and female mice at the end of the 13-week inhalation study of nitromethane. CONCLUSIONS: Under the conditions of these 2-year inhalation studies, there was no evidence of carcinogenic activity of nitromethane in male F344/N rats exposed to 94, 188, or 375 ppm. There was clear evidence of carcinogenic activity of nitromethane in female F344/N rats based on increased incidences of mammary gland fibroadenomas and carcinomas. There was clear evidence of carcinogenic activity of nitromethane in male B6C3F1 mice based on increased incidences of harderian gland adenomas and carcinomas. There was clear evidence of carcin ogenic activity in female B6C3F1 mice, based on increased incidences of liver neoplasms (primarily adenomas) and harderian gland adenomas and carcinomas. Increased incidences of alveolar/bronchiolar adenomas and carcinomas in male and female mice exposed to nitromethane were also considered to be related to chemical administration. Exposure to nitromethane by inhalation for 2 years resulted in increased incidences of nasal lesions including degeneration and metaplasia of the olfactory epithelium and degeneration of the respiratory epithelium in male and female mice. Synonym: Nitrocarbol
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4,4'-Thiobis(6- t -butyl- m -cresol) (TBBC) is used in the rubber and plastics industries as an antioxidant. TBBC is also used as a stabilizer in polyethylene and polyolefin packaging materials for foodstuffs. Toxicology and carcinogenesis studies were conducted by administering TBBC (99% pure) in feed to groups of male and female F344/N rats and B6C3F1 mice for 15 days, 13 weeks, and 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium and cultured Chinese hamster ovary cells. 15-DAY STUDY IN RATS: Groups of 10 male and 10 female F344/N rats were fed diets containing 0, 1,000, 2,500, 5,000, 10,000 or 25,000 ppm TBBC for 15 days. Rats given to 1,000, 2,500, 5,000, or 10,000 ppm received approximate doses of 95, 235, 335, or 365 mg TBBC per kilogram body weight per day (males) or 85, 220, 325, or 270 mg/kg per day (females). Approximate doses for rats receiving 25,000 ppm could not be calculated due to early deaths. All 25,000 ppm rats and three male and four female 10,000 ppm rats died. Surviving rats in the 10,000 ppm groups had a significant weight loss and the final mean body weights of 5,000 and 10,000 ppm male and female rats were significantly lower than those of the controls. Male and female rats exposed to 5,000, 10,000, or 25,000 ppm TBBC consumed markedly less feed than the controls. Diarrhea occurred in 5,000, 10,000, and 25,000 ppm males and females. The principal lesions attributed to the administration of TBBC were renal papillary and tubule necroses which occurred in 10,000 ppm rats. Focal necrosis or erosions of the glandular stomach also occurred in some 10,000 ppm rats. Changes observed in the thymus and spleen were attributed to debilitation or stress; bone marrow depletion was attributed to nutrient deficiency accompanying weight loss. 15-DAY STUDY IN MICE: Groups of 10 male and 10 female B6C3F1, mice were fed diets containing 0, 1,000, 2,500, 5,000, 10,000, or 25,000 ppm TBBC for 15 days. Mice given 1,000, 2,500, or 5,000 ppm received approximate doses of 285, 585, or 475 mg TBBC per kilogram body weight per day (males) or 360, 950, or 1,030 mg/kg per day (females). Approximate doses for mice given 10,000 or 25,000 ppm could not be calculated due to early deaths. All 10,000 and 25,000 ppm mice died, as did eight males and eight females given 5,000 ppm. A significant weight loss occurred in surviving 5,000 ppm males and females and the final mean body weights of 2,500 ppm females and 5,000 ppm males and females were significantly lower than those of the controls. Feed consumption by mice given 5,000, 10,000, or 25,000 ppm was markedly reduced. Diarrhea occurred in all 25,000 ppm mice and in most male and female mice given 5,000 or 10,000 ppm. Renal tubule necrosis occurred in eight males and three females in the 5,000 ppm groups. Lymphocytic depletion of Iymphoid tissues in many 5,000 ppm males and females was attributed to debilitation and stress or to nutrient deficiency accompanying weight loss. 13-WEEK STUDY IN RATS: Groups of 10 male and 10 female F344/N rats were fed diets containing 0, 250, 500, 1,000, 2,500, or 5,000 ppm TBBC for 13 weeks. These exposure levels delivered approximate doses of 15, 30, 60, 165, or 315 mg TBBC per kilogram body weight per day (males) or 15, 35, 70, 170, or 325 mg/kg per day (females). All rats survived to the end of the study. The final mean body weight of 5,000 ppm males was 40% lower than that of the controls; the final mean body weight of 5,000 ppm females was 27% lower than that of the controls. Feed consumption by male and female rats exposed to 5,000 ppm TBBC was markedly lower than that by the controls throughout the study. The absolute and relative liver weights of 5,000 ppm females were significantly greater than those of the controls. Serum alkaline phosphatase (ALP) levels were significantly higher in 2,500 and 5,000 ppm males and slightly higher in 5,000 ppm females. Serum alanine aminotransferase levels were significantly higher in 2,500 and 5,000 ppm males and females. Hematocrit and hemoglobin concentrations and mean erythroions and mean erythrocyte volume (MCV) values were significantly lower in 1,000, 2,500, and 5,000 ppm males than in controls; MCV values were also significantly lower in 5,000 ppm females. A dose-related significant increase in forelimb and hindlimb grip strength was observed in exposed male and female rats. Histopathologic findings in the liver of 2,500 and 5,000 ppm males and females included hypertrophy of Kupffer cells, bile duct hyperplasia, and individual cell necrosis of hepatocytes; centrilobular hepatocyte hypertrophy also occurred in males and females exposed to 5,000 ppm TBBC. Macrophages were increased in size and number in the mesenteric Iymph nodes of males and females exposed to 5,000 ppm, and to a lesser extent in 2,500 ppm male and female rats. Pigmentation and degeneration of the renal cortical tubule epithelial cells was also present in males and females in the 2,500 and 5,000 ppm groups; cortical tubule necrosis occurred in 5,000 ppm males and females. 13-WEEK STUDY IN MICE: Groups of up to 10 male and 10 female B6C3F1 mice were fed diets containing 0, 100, 250, 500, 1,000, or 2,500 ppm TBBC for 13 weeks. These exposure levels delivered approximate doses of 15, 30, 65, 145, or 345 mg TBBC per kilogram body weight per day (males) or 10, 35, 60, 165, or 340 mg/kg per day (females). All mice survived to the end of the study. The final mean body weights of 2,500 ppm males and of 500,1,000, or 2,500 ppm females were significantly lower than those of the controls. Feed consumption by 2,500 ppm males averaged 24% lower than that by controls through week 3 and was similar to that by controls for the remainder of the study. Feed consumption by females receiving 2,500 ppm averaged 27% less than that by the controls during most of the study. The absolute and relative liver weights of males and females exposed to 2,500 ppm TBBC were slightly but significantly greater than those of the controls. Males exposed to 500, 1,000, or 2,500 ppm and females exposed to 2,500 ppm had significantly increased absolute and relative spleen weights. No clinical findings in mice were considered chemical related. Hematocrit concentrations and erythrocyte counts of males receiving 1,000 or 2,500 ppm were significantly less than those of the controls; hemoglobin concentration in males receiving 2,500 ppm was significantly less and mean erythrocyte volume was significantly less in males receiving 2,500 ppm. Females in the 1,000 and 2,500 ppm groups had significantly decreased hematocrit concentrations and erythrocyte counts; 2,500 ppm females also had significantly decreased hemoglobin concentrations and mean erythrocyte volumes. Kupffer cell hypertrophy, bile duct hyperplasia, and an increase in size and number of macrophages in mesenteric Iymph nodes were present in 2,500 ppm male and female mice. 2-YEAR STUDY IN RATS: Doses selected for the 2-year study of TBBC were based on the lower body weights and liver and kidney toxicity observed at 5,000 ppm in the 13-week study. Groups of 115 male and 75 female F344/N rats were fed diets containing 0, 500, 1,000, or 2,500 ppm TBBC for 2 years. Based on average daily feed consumption, these exposure levels resulted in a daily ingestion of TBBC of approximately 20, 40, or 100 mg/kg body weight for males and 20, 45, or 120 mg/kg body weight for females. Hematology, clinical chemistry, and urinalysis evaluations were performed on 15 male and 15 female rats from each group at 3, 9, and 15 months. Also at 15 months, an additional 10 male and 10 female rats from each group were evaluated for histopathology, hematology, and clinical chemistry. Forty male rats per group were evaluated for neurotoxic effects. Survival, Body Weights, Feed Consumption, and Clinical Findings: Two-year survival rates and mean body weights of exposed male and female rats were generally similar to those of the controls. The mean body weights of 2,500 ppm male rats were slightly lower than those of the controls throughout the study. At week 65, the mean body weight of 2,500 ppm females was 14% lower than that of the controls, but the final mean body weight of this group was 6% lower than that of the control group. Feed consumption, behavior, and general health and appearance of exposed male and female rats were similar to those of the controls. Hematology and Clinical Chemistry: Results of the hematology evaluation were not uniformly consistent at 3, 9, and 15 months in one set of rats, nor were they consistent between the two sets of rats evaluated at 15 months. Slight but significant decreases in hematocrit levels, hemoglobin concentrations, and erythrocyte counts were observed in the 1,000 and 2,500 ppm groups in one set of males at 15 months. Similar significant decreases in hematocrit level and hemoglobin concentration occurred in 2,500 ppm females at 9 months. Mean erythrocyte hemoglobin and mean erythrocyte hemoglobin concentration of 2,500 ppm females were also significantly lower than those of controls at 9 months and in both sets of female rats evaluated at 15 months. Platelet counts of 2,500 ppm male and female rats were slightly but significantly higher than those of controls at 3 and 9 months. Platelet counts were also slightly but significantly increased in 2,500 ppm males of one set evaluated at 15 months, and in 2,500 ppm females of the second set evaluated at 15 months. Serum activities of alkaline phosphatase, alanine aminotransferase, and sorbitol dehydrogenase in 2,500 ppm males were significantly greater than those in the controls at 3, 9, and 15 months. Alkaline phosphatase activities in both sets of 1,000 ppm males evaluated at 15 months were also significantly greater than those of controls. Serum activities of alanine aminotransferase and sorbitol dehydrogenase in 2,500 ppm females were also significantly greater than those in controls at 3, 9, and 15 months. Neurotoxicity Findings: There were no significant inhibitory effects of TBBC on motor nerve excitability or conduction, neuromuscular transmission, or muscle contractility. There were no microscopic lesions in the sciatic nerve, quadriceps muscle, or teased nerve preparations of sciatic nerve that could be attributed to TBBC administration. Pathology Findings: At the 15-month interim evaluation, the absolute and relative liver weights of 2,500 ppm female rats were significantly greater than those of controls; at 15 months and at the end of the study, the incidences of Kupffer cell hypertrophy, hepatocyte cytoplasmic vacuolization, and mixed cell foci were also significantly increased. At the end of the study, the incidence of hepatocellular fatty change was significantly increased in 2,500 ppm females. The incidence of Kupffer cell hypertrophy was significantly increased in 2,500 ppm males at 15 months and at 2 years; the incidence of cytoplasmic vacuolization was significantly increased in all exposed males at 15 months but only moderately increased in 1,000 and 2,500 ppm males at 2 years; the incidence of basophilic foci was significantly increased in 2,500 ppm males at 15 months and the incidence of mixed cell foci was significantly increased in 1,000 and 2,500 ppm male rats at 2 years. The incidences of hepatocellular adenoma or carcinoma (combined) in exposed male rats were not significantly greater than that in the controls (0 ppm, 1/50; 500 ppm, 3/50; 1,000 ppm, 3/50; 2,500 ppm, 5/49), were within the historical control range, and were not considered chemical related. The severity of nephropathy was significantly increased in 2,500 ppm female rats. There was a significant negative trend in the incidence of mammary gland fibroadenoma, adenoma, or carcinoma (combined) in female rats (32/50, 24/50, 11/50, 16/50), and the incidences of fibroadenoma in 1,000 and 2,500 ppm females were significantly less than that of the controls. 2-YEAR STUDY IN MICE: Because of the reduction in body weights, the increase in liver and spleen weights, and the accompanying histopathologic changes in the liver of 2,500 ppm male and female mice in the 13-week study, the doses selected for the 2-year study were 250, 500, and 1,000 ppm. Groups of 80 male and 80 female mice were fed diets containing 0, 250, 500, or 1,000 ppm TBBC for 2 years. Based on average daily feed consumption, these exposure levels resulted in the daily ingestion of approximately 30, 60, or 145 mg TBBC/kg body weight for males and 45, 110, or 255 mg TBBC/kg body weight for females. Nine or 10 animals from each exposure group were evaluated at 3, 9, and 15 months. Survival, Body Weights, Feed Consumption, and Clinical Findings: Two-year survival rates of exposed male and female mice were similar to those of the controls. The final mean body weights of male and female mice exposed to 1,000 ppm were 8% and 18% lower than those of the controls, respectively. The final mean body weights of females exposed to 250 or 500 ppm were 8% to 9% lower than that of the controls. Feed consumption by exposed males was similar to that by controls, and there were no clinical findings attributed to TBBC administration. Hematology and Clinical Chemistry: Hematocrit level, hemoglobin concentration, and erythrocyte count in 1,000 ppm male mice were significantly lower than those in controls at the 15-month interim evaluation. Serum alkaline phosphatase activities in 1,000 ppm males were slightly but significantly greater than those in controls at 3 and 9 months, as was the serum alkaline phosphatase activity in 1,000 ppm females at 9 months. Serum levels of total bilirubin in all exposed groups of males were significantly greater than those in controls at 9 and 15 months. Pathology Findings: In the liver of male mice, negative trends in the incidences of fatty change, clear cell foci, and adenoma or carcinoma combined occurred at the end of the 2-year study. There were no compound-related increased incidences of neoplasms or nonneoplastic lesions in mice receiving TBBC for 2 years. A negative trend in the incidence of fatty change in the liver of male mice also occurred at 15 months. GENETIC TOXICOLOGY: 4,4'-Thiobis(6- t -butyl- m -cresol) was not mutagenic in Salmonella typhimurium strains TA98, TA100, TA1535, or TA1537 with or without exogenous metabolic activation (S9). Sister chromatid exchanges were induced in cultured Chinese hamster ovary cells treated with TBBC, with and without S9, but no increases in chromosomal aberrations were noted in cultured Chinese hamster ovary cells after treatment with TBBC. CONCLUSIONS: Under the conditions of these 2-year feed studies, there was no evidence of carcinogenic activity of 4,4'-thiobis(6- t -butyl- m -cresol) in male or female F344/N rats administered 500, 1,000, or 2,500 ppm or in male or female B6C3F1, mice administered 250, 500, or 1,000 ppm. Nonneoplastic lesions associated with exposure to TBBC included: Kupffer cell hypertrophy, cytoplasmic vacuolization, and mixed cell foci in the liver of male and female rats, fatty change in the liver of female, rats, and an increase in the severity of nephropathy in the kidney of female rats. In addition, decreased incidences of fibroadenoma, adenoma, or carcinoma (combined) were observed in the mammary gland of female rats. Decreases also occurred in the incidences of fatty change, clear cell foci, and adenoma or carcinoma (combined) in the liver of male mice. Synonyms: 4,4'-Thiobis(6- t -butyl-3-cresol); bis(3- t -butyl-4-hydroxy-6-methylphenyl)sulfide
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Scopolamine hydrobromide trihydrate is used in ophthalmic preparations and as a preanesthetic sedative. Its major use is in transdermal patches for the treatment of motion sickness. Scopolamine hydrobromide trihydrate was selected for study because of considerable human exposure resulting from its use in prescription and over-the-counter preparations. Scopolamine was a suspect carcinogen because it contains an aliphatic epoxide moiety which may act as a biological alkylating agent. Male and female F344/N rats and B6C3F1 mice received scopolamine hydrobromide trihydrate (89% pure) in distilled water by gavage for 16 days, 14 weeks, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, cultured Chinese hamster ovary cells, and mouse peripheral blood erythrocytes. 16-DAY STUDY IN RATS: Groups of five male and five female rats were administered 0, 75, 150, 300, 600, or 1,200 mg scopolamine hydrobromide trihydrate/kg body weight in distilled water by gavage for 16 days. All rats survived to the end of the study. The final mean body weights and body weight gains of males receiving 600 and 1,200 mg/kg and the mean body weight gain of males receiving 300 mg/kg were significantly lower than those of the control group. Clinical findings included bilateral pupillary dilation in all dosed animals and red eyelids in males and females receiving 1,200 mg/kg. There were no significant treatment-related gross or microscopic lesions. 16-DAY STUDY IN MICE: Groups of five male and five female mice were administered 0, 150, 250, 450, 900, or 1,800 mg scopolamine hydrobromide trihydrate/kg body weight in distilled water by gavage for 16 days. One male and two females receiving 1,800 mg/kg and one female receiving 150 mg/kg died during the study. The final mean body weights and body weight gains of dosed mice were similar to those of the control groups. Clinical findings related to scopolamine hydrobromide trihydrate administration included bilateral pupillary dilation and squinting in all dosed males and females. The relative liver weights of males receiving 1,800 mg/kg and of females in all dosed groups were significantly greater than those of the control groups. There were no significant treatment-related gross or microscopic lesions. 14-WEEK STUDY IN RATS: Groups of 10 male and 10 female rats were administered 0, 15, 45, 135, 400, or 1,200 mg scopolamine hydrobromide trihydrate/kg body weight in distilled water by gavage for 14 weeks. One female receiving 45 mg/kg, one male and one female receiving 135 mg/kg, six males and one female receiving 400 mg/kg, and eight males and seven females receiving 1,200 mg/kg died during the study. The final mean body weights and mean body weight gains of all dosed males and females were significantly lower than those of the control groups. Clinical findings included bilateral pupillary dilation in all dosed males and females and reddening of the eyes in 15 mg/kg males and 135, 400, and 1,200 mg/kg males and females. Hematocrit, hemoglobin concentration, and/or erythrocyte count in male and female rats receiving 45 mg/kg or greater were slightly higher than those of the control groups. In general, these changes were most prominent in rats in the 400 and 1,200 mg/kg groups. Higher hematocrit, hemoglobin concentration, and erythrocyte count were likely due to hemoconcentration from dehydration (relative erythrocytosis). A minimal to mild mature neutrophilia, evidenced by higher segmented neutrophil numbers than in the control group, occurred in all dosed male rats. Sperm morphology and vaginal cytology parameters in dosed rats were similar to those in the control groups. Nine male and five female dosed rats died from esophageal obstructions consisting of feed and bedding material in the posterior pharynx. Tracheal obstruction occurred concurrently with esophageal obstruction as a result of food build-up in the oropharyngeal region. This condition is considered to be secondary to the inhibitory effects of scopolamine hydrobromide trihydrate on salivary gland secretions and on esopon esophageal smooth muscle involved in swallowing. There were no other significant treatment-related gross or microscopic findings. 14-WEEK STUDY IN MICE: Groups of 10 male and 10 female mice were administered 0, 15, 45, 135, 400, or 1,200 mg scopolamine hydrobromide trihydrate/kg body weight in distilled water by gavage for 14 weeks. One male receiving 135 mg/kg and two males and one female receiving 1,200 mg/kg died during the study. The final mean body weights and mean body weight gains of all dosed male groups and females receiving 45 mg/kg and above were significantly lower than those of the control groups. Clinical observations included bilateral pupillary dilation, hyperactivity, and hypoactivity. A minimal to mild mature neutrophilia, similar to that which occurred in the 14-week rat study, occurred in male mice receiving 45 mg/kg or greater. As in the rat study, there was no microscopic evidence of inflammation that could account for the neutrophilia. The estrous cycle length of 1,200 mg/kg females was significantly greater than that in the control group. There were no significant treatment-related gross or microscopic lesions. 2-YEAR STUDY IN RATS: Groups of 60 male and 60 female rats were administered 0, 1, 5, or 25 mg scopolamine hydrobromide trihydrate/kg body weight in distilled water by gavage for 104 weeks. Ten males and ten females from each dose group, excluding the 1 mg/kg female group, were evaluated at 15 months. Survival, Body Weights, Clinical Findings, and Ophthalmic Examination Findings: The survival rates of female rats receiving 1 and 25 mg/kg were significantly lower than that of the control group. Mean body weights of 1 and 5 mg/kg males and females were similar to those of the controls throughout the study. However, mean body weights of 25 mg/kg males and females were generally lower than those of the control groups after about week 25. Clinical findings included bilateral pupillary dilation in all dosed males and females. Ophthalmic examination revealed no significant findings. Hematology: Compared to controls, hematocrit was slightly higher in the 25 mg/kg male rats, similar to the effects observed in the 14-week study; this is consistent with dehydration resulting in hemoconcentration. Reticulocyte numbers in the 25 mg/kg female rats were slightly lower than those in the controls. This result is consistent with the lower body weights, and thus a decreased nutritional status, exhibited by these animals. Plasma Scopolamine Determinations: The serum scopolamine concentrations were 6 ng scopolamine/mL serum for the 5 mg/kg female sample and 12 and 28 ng/mL for the 25 mg/kg male and female samples, respectively. The amounts of scopolamine in the other serum samples were below the minimum detection limit (4 ng/mL) of the analysis method. Neurobehavioral Findings: Horizontal motor activity of 25 mg/kg females was significantly greater than that of the control group on days 90, 180, and 360. Startle response of 5 and 25 mg/kg females was significantly lower than that of the control group on day 90. On day 180, passive avoidance of 25 mg/kg males was significantly lower than that of the control group. Pathology Findings: The incidences of adenoma of the pituitary gland pars distalis decreased with increasing dose in both male and female rats; however, this trend was only significant in males (males: vehicle control, 19/49; 1 mg/kg, 17/49; 5 mg/kg, 13/50; 25 mg/kg, 10/50; females: 20/50, 13/60, 14/50, 10/50). The incidences of adenoma of the pituitary gland pars distalis in 25 mg/kg males and all groups of dosed females were below the NTP historical control range. The incidences of hyperplasia were not significantly different from those in the control groups. The incidences of mononuclear cell leukemia in 25 mg/kg males and females were significantly lower than those of the control groups (males: 33/50, 21/50, 26/50, 24/50; females: 20/50, 6/60, 13/50, 4/50). The incidence of mononuclear cell leukemia in females receiving 25 mg/kg was well below the NTP historical range. 2-YEAR STUDY IN MICE: Groups of 70 male and 70 female mice were administered 0, 1, 5, or 25 mg scopolamine hydrobromide trihydrate/kg body weight in distilled water by gavage for 104 to 105 weeks. Ten control animals and ten animals from each dose level were evaluated at 15 months. Survival, Body Weights, Clinical Findings, and Ophthalmic Examination Findings Survival of dosed males and females was similar to that of the controls. The mean body weights of males and females receiving 1 mg/kg were similar to those of the control groups throughout the majority of the study. The mean body weights of 5 mg/kg males and females were slightly lower than those of the controls. The mean body weights of males and females receiving 25 mg/kg were lower than those of the control groups after week 13. Clinical findings included bilateral pupillary dilation in all dosed male and female groups. Ophthalmic examination revealed no significant findings. Hematology: Hematocrit, hemoglobin concentration, and erythrocyte count in 25 mg/kg female mice were slightly lower than those in the control group. These results are consistent with development of a minimal normocytic, normochromic nonresponsive anemia. The anemia may be related to the lower body weights exhibited by these animals and are presumed to be due to a decreased nutritional status. Pathology Findings: The combined incidences of hepatocellular neoplasms (adenoma or carcinoma) occurred with a significant negative trend in males and females (males: vehicle control, 30/50; 1 mg/kg, 33/50; 5 mg/kg, 14/50; 25 mg/kg, 15/50; females: 22/51, 21/50, 16/50, 9/51). The combined incidences of hepatocellular neoplasms in 5 and 25 mg/kg males were within the NTP historical control range. The incidences of clear cell foci and eosinophilic foci in dosed male groups, and eosinophilic foci in 25 mg/kg females, were significantly lower than those of the control groups. The incidences of many spontaneously occurring nonneoplastic lesions were significantly lower in dosed mice than in the control groups and usually decreased with increasing dose. These included kidney nephropathy, alveolar epithelial hyperplasia, hyperplasia of the pancreatic islets, bone marrow myelofibrosis, hyperplasia of the pituitary gland pars distalis, cystic hyperplasia of the uterus, and hematopoietic cell proliferation of the spleen. The decreased incidences of these spontaneous lesions were most likely a result of lower body weights in dosed animals. GENETIC TOXICOLOGY: Scopolamine hydrobromide trihydrate did not induce mutations in any of five strains of Salmonella typhi murium, with or without S9 metabolic activation enzymes, nor did it induce sister chromatid exchanges in cultured Chinese hamster ovary cells, with or without S9. A weakly positive response was obtained, however, in a chromosomal aberrations test conducted in cultured Chinese hamster ovary cells with very high doses of scopolamine hydrobromide trihydrate in the presence of S9; without S9, no increase in aberrations was noted. Despite the evidence for chromosomal damage observed in vitro, no increase in the frequencies of micronucleated normochromatic erythrocytes was observed in peripheral blood samples of male or female mice exposed to scopolamine hydrobromide trihydrate for 14 weeks by gavage. CONCLUSIONS: Under the conditions of these 2-year gavage studies, there was no evidence of carcinogenic activity of scopolamine hydrobromide trihydrate in male or female F344/N rats or B6C3F1 mice administered 1, 5, or 25 mg/kg. Synonyms: Scopolamine hydrobromide, 6,7-epoxytropan-3-yl, euscopol, hydroscine hydrobromide, hyoscine bromide, (-)-hyoscine hydrobromide, hysco, isoscopil, scopolammonium bromide, (s)-tropate hydrobromide trihydrate, lα-tropyl-a-scopine
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English Name Latin Name Job's tears seed Coicis Semen, Japanese Ardisia Herb Japanese Ardisia Herb, White Hyacinth Bean Semen Dolichoris Album, Spreading Hedyotis Herb Hedyotis diffusa, Willowleaf Swallowwort Rhizome Rhizoma Cynanchi Stauntonii, Large head Atractylodes Rh Rhizoma Atractylodis Macrocephalae, Sessile Stemona Root Japanese Stemona Root, Lily Lilium brownii var. viridulum, Seman Platycladi Seman, Isatis root Isatis tinctoria, Herba Lobeliae Chinensis Lobelia chinensis Lour, Pinellia ternata Pinellia ternata (Thunb.) Breit, Scutellaria barbata Scutellaria barbata, CoasiaI GIehnia Root Glehnia littoralis, Fritillary fritillary, Ficus pumila Linn Ficus pumila, Seed-coat of Hyacinth Dolichos, Areca Seed, Betel Nut Semen Arecae, Malaytea Scurfpea Fruit Fructus Psoraleae, Semen raphani , Silkworm shit Faeces Bombycis, Siberian Cocklour Fruit Fructus Xanthii, Rhizome of Swordlike Atractylodes Rhizoma Atractylodis, Root of Chinese Thorowax Radix Bupleuri, Radices paeoniae rubra Paeoniae Rubra Radix, Dan - shen Root Salviae Miltiorrhizae Radix, Tree Peony Root - bark Moutan Radicis Cortex, Chinese Goldthread Rhizome Coptidis Rhizoma, Skunk Bugbane Rhizome Cimicifugae Foetidae Rhizoma, Coix seed Semen Coicis Szechwan Chinaberry Fruit Fructus Meliae Toosendan, Radix Cyathulate Radix Cyathulae, Common Andrographis Herb Herba Andrographis, Radix et Caulis Acanthopanacis Senticosi Radix et Caulis Acanthopanacis Senticosi, Japanese Thistle Herbor Root Herba seu Radix Cirsii Japonici, Indigowoad Leaf, Leaf of Indigowoad Folium Isatidis, Danshen Root, Root of Dan-shen Salviae Miltiorrhizae Radix et Rhizoma, Root of Pilose Asiabell Radix Codonopsis, Fructus Oryzae Germinatus Fructus Oryzae Germinatus, Humifuse Euphorbia Herb Herba Euphorbiae Humifusae, Chinese Waxgourd Peel Exocarpium Benincasae, Waxgourd seed Semen Benincasae, Rabdosia rubesens,hamst Rabdosia rubescens, Rhioxma Curcumae Aeruginosae Rhizoma Curcumae, Divaricate Saposhnikovia RootRadix Saposhnikoviae, Indian Buead Poria, Pine among the Indian Bread, Blighted Wheat Fructus Tritici Levis, Radix Glycyrrhizae Radix Glycyrrhizae, Toad skin, Perfoliate Knotweed Herb Polygonum perfoliatum, Ligusticum sinense Oliv Rhizoma Ligustici, Barbary Wolfberry Fruit Fructus Lycii, Herba Pogostemonis Herba Pogostemonis, Sargassum Sargassum, Yerbadetajo Herb Herba Ecliptae Eclipta prostrala, Terminalia chebula Retz, Taxus chinensis Taxus chinensis (Pilger) Rehd, Flos Carthami Flos Carthami, Root of Kirilow Rhodiola Herba Rhodiolae, Figwortflower Picrorhiza Rhizome Rhizoma Picrorhizae, Polygonum cuspidatum Rhizoma Polygoni Cuspidati, Pricklyash Peel Pericarpium Zanthoxyli, Talcum Talcum, Exocarpium Citri Grandis Exocarpium Citri Grandis, Phellodendron Chinese Schneid Cortex Phellodendri, Manyflower Solomonseal Rhizome Rhizoma Polygonati, Radix Astragali Radix Astragali seu Hedysari, Radix Scutellariae, Flos Celosiae Cristae Flos Celosiae Cristatae, Suberect Spatholobus Stem Caulis Spatholobi, Rhizoma Curcumae Longae Rhizoma Curcumae Longae, Christina Loosestrife HerbHerba Lysimachiae, Japanese Honysuckle Flower Bud Flos Lonicerae, Cherokee Rose Fruit Fructus Rosae Laevigatae, Chrysanthemum flower Flos Chrysanthemi, Spikemoss Herba Selaginellae, Cassia seed Semen Cassiae, Lightyellow sophora root Radix Sophorae Flavescentis, Kelp Laminariae Thallus, Semen Litchi Semen Litchi, Chinese trumpet creeper Campsis grandiflora, Diverse Wormwood Herb Herba Artemisiae Anomalae, Radix Gentianae Gentiana Scabra Bunge, Reed Rhizome Stemmacanthae Unifori Radix, Caulis Trachelospermi Trachelospermi Jasminoidis Caulis, Lv Bean Spermodermis Phaseoli Radiati, European Verbena Herb Herba Verbenae Officinalis, Herba Portulacae Portulaca oleracea L, Radix Ophiopogonis Ophiopogonis Radix, Fructus Hordei Germinatus Hordei Germinatus Fructus, Concha Ostreae Concha Ostreae, Costustoot, Common Vladimiria Root Aucklandiae Radix, Fructus Ligustri Lucidi Ligustri Lucidi Fructus, Fortune Eupatorium Herb Eupatorii Fortunei Herba, Folium Eriobotryae Eriobotryae Japonicae Folium, Dandelion Herba Taraxaci, Flower of Shepherdspurse Capsella bursa-pastoris (L.)Medic), Rhizoma Homalomenae Rhizoma Homalomenae, Gordon Enryale Seed Euryales Semen, Radix Gentinae Gentianae Macrophyllae Radix, Cortex Fraxini Fraxini Cortex, Caulis SinomeniiI Caulis Sinomenii, Semen Celosiae Celosiae Argenteae Semen, Herba Dianthi Dianthi Superbi Herba, Caulis Lonicerae Lonicerae Caulis, Cortex CinnamoniCinnamomi Cassiae Cortex, Rhizoma Srarganii Rhizoma Sparganii, Sanchi Panax pseudo-ginseng var, Radix tetrastigme Tetrastigma hemsleyanum Diels et Gilg, Folium Mori Mori Folium, Chinese yam Dioscorea opposite, Amorphophallus rivieri Durieu Amorphophallus rivieri Durieu, Snake venom, Snake Slough Serpentis Periostracum, Rhizoma Belamcandae rhizoma belamcandae, Largetrifoliolious Bugbane RhizmomeRhizoma Cimicifugae, Radix Sanguisorbae SanguisorbaofficinalisL, Eucommia ulmoides Oliver Eucommia ulmoides, Rhizoma Zingiberis RecensZingiber officinale Roscoe, Salvia chinensis Benth Salvia chinensis Benth, Folium Photiniae Photinia serrulata Lindl, Lignum Sappan Lignum Sappan, Semen Persicae Semen Persicae, Radix Asparagi Radix Asparagi, Root of Nakedcaule Groundsel Radix Semiaquilegiae, Root of Common carpesium Herba Carpesii Abrotanoidis, Semen lepidii Semen Lepidii, Herb of Tuberculate Speranskia Phryma leptostachya L. subsp. asiatica (Hara), China Dodder Semen Cuscutae, Semen Vaccariae Semen Vaccariae, Herb of Coffee Senna Cassia occidentalis Linn, Fructus Mume Fructus Mume, Root of Combined Spicebush Radix Linderae, Fig Ficus carica Linn, Medicinal Evodia Fruit Evodia rutaecarpa (Juss.) Benth, Chinese Gall, Chinese Nut-gall Rhus chinensis Mill, Sessileflower Acanthopanax Bark Cortex Acanthopanax Radicis, All-grass of Bluecalyx Japanese Rabdosia, Fructus Foeniculi Fructus Foeniculi, Common Cephalanoplos Herb Cirsium setosum (Willd.) MB, Flos Magnoliae Flos Magnoliae, Paniculate Swallowwort Root Cynanchum paniculatum (Bunge) Kitagawa, Linseed,seed of Flax Linseed seed of Flax, Fructus Alpiniae Oxyphyllae Alpinia oxyphylla Miq, Job's tears seed Semen Coicis, Herba Artemisiae Scopariae ArtemisiacapillarisThunb, Folium Ginkgo Ginkgobiloba, Heartleaf Houttuymia Herb Houttuynia cordata Thunb, Turmeric Root-tuber Radix Curcumae, Akebia Fruit Foreknowledge, Hiraute Shiny Bugleweek Herb Aconitum gymnandrum Maxim, Rhizoma Paridis RhizomaParidis, Polyporus Polyporus, Root of Sinkiang Arnebia Lithospermum erythrorhizon Sieb. et Zucc, Herba Violae Viola yedoensis Makino, Fluoritum Fluoritum Caulis Perillae Perilla frutescens （L.）Britton
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C.I. Direct Blue 218 is a copper chelated dye used for cellulose, acetate, nylon, silk, wool, tissue, papers, and textile goods with a urea-formaldehyde finish. C.I. Direct Blue 218 is one of five chemicals/dyes that are part of the National Toxicology Program's Benzidine Dye Initiative, established to determine the toxicity and carcinogenicity of representative benzidine congeners, congener-derived dyes, and benzidine-derived dyes. Industrial grade C.I. Direct Blue 218 was selected for study because of its widespread use. Because of the high salt content, the dye was desalted prior to use. Toxicology and carcinogenesis studies were conducted by administering C.I. Direct Blue 218 in feed to groups of male and female F344/N rats and B6C3F1 mice for 14 days, 13 weeks, and 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, cultured Chinese hamster ovary cells, and Drosophila melanogaster. 14-DAY STUDY IN RATS: Groups of five male and five female F344/N rats were fed diets containing 0, 1,000, 3,000, 7,000, 15,000, or 30,000 ppm C.I. Direct Blue 218. All rats survived until the end of the study. Rats receiving 30,000 ppm lost weight, and the mean body weight gain of males receiving 15,000 ppm was significantly lower than that of the controls. Feed consumption by rats receiving 30,000 ppm was lower than that by the controls. Decreased organ weights at the 30,000 ppm level were related to the decreased body weights at this exposure level. 14-DAY STUDY IN MICE: Groups of five male and five female mice were fed diets containing 0, 1,000, 3,000, 7,000, 15,000, or 30,000 ppm C.I. Direct Blue 218. All mice survived until the end of the study. The final mean body weight of males receiving 30,000 ppm was 25% lower than that of controls and that of 30,000 ppm females was 20% lower than that of controls. Feed consumption by exposed and control groups was similar except for the 15,000 and 30,000 ppm groups. Feed spillage, due to reduced palatability, precluded the accurate determination of feed consumption by these two groups. Male and female mice receiving 30,000 ppm appeared hyperactive and emaciated during the last week of the study. Decreased organ weights were noted at 30,000 ppm and were attributed to the decreased mean body weights at this exposure level. 13-WEEK STUDY IN RATS: Groups of 10 male and 10 female rats were fed diets containing 0, 3,000, 10,000, or 20,000 ppm C.I. Direct Blue 218. All male and female rats survived until the end of the study. Rats exposed to 3,000,10,000, or 20,000 ppm C.I. Direct Blue 218 received approximate daily doses of 200, 600 or 1,300 mg dye/kg body weight (males) and 200, 800, or 1,400 mg/kg (females). The final mean body weight of male rats receiving 20,000 ppm was 24% lower than that of the controls and the final mean body weight of female rats receiving 20,000 ppm was 15% lower than that of the controls. Feed consumption by exposed and control groups was similar except in the 20,000 ppm groups where feed spillage was noted. Absolute and relative kidney weights of rats receiving 10,000 or 20,000 ppm were significantly greater than those of controls. Significantly decreased organ weights were noted, particularly in the 20,000 ppm groups, and were attributed to the lower mean body weights at this exposure level. The hematocrit, hemoglobin, mean erythrocyte volume, and mean erythrocyte hemoglobin values in male and female rats receiving 10,000 and 20,000 ppm were significantly lower than those of controls. Serum levels of alanine aminotransferase and sorbitol dehydrogenase in male and female rats receiving 20,000 ppm were significantly higher than those of controls, which is consistent with hepatocellular injury. Male rats receiving 10,000 ppm and male and female rats receiving 20,000 ppm had hepatic lesions consisting of intracytoplasmic pigment in periportal Kupffer cells, minimal to mild individual hepatocyte necrosis, increased numbers of binucleated and multinucleated hepatocytes, and minimal bile duct hyperplasia. Male and female rats receiving 20,000 ppm had ys receiving 20,000 ppm had yellow-green pigment within the cytoplasm of proximal convoluted tubules of the kidney. Microconcretions of mineral were observed along the corticomedullary junction of the kidney in most female rats, but the numbers of microconcretions in kidney sections were increased in females that received 20,000 ppm. 13-WEEK STUDY IN MICE: Groups of 10 male and 10 female B6C3F1 mice were fed diets containing 0, 3,000, 10,000, or 20,000 ppm C.I. Direct Blue 218. There were no deaths attributed to C.I. Direct Blue 218. Mice exposed to 3,000, 10,000, or 20,000 ppm C.I. Direct Blue 218 received approximate daily doses of 400, 1,500, or 3,600 mg dye/kg body weight (males) and 400, 1,800, or 4,000 mg/kg (females). The final mean body weight of males that received 20,000 ppm was 24% lower than that of the controls, and the final mean body weight of females that received 20,000 ppm was 14% lower than that of controls. Feed consumption by exposed mice was similar to that by controls except in the 20,000 ppm groups where feed spillage was noted. Significant differences in organ weights were noted at 20,000 ppm which were attributed primarily to the lower mean body weights in these exposure groups. The hematocrit, hemoglobin, mean erythrocyte volume, and mean erythrocyte volume, and mean erythrocyte hemoglobin values were significantly lower in males and females receiving 10,000 and 20,000 ppm. Serum levels of alanine aminotransferase and sorbitol dehydrogenase in male and female mice receiving 10,000 and 20,000 ppm were significantly higher than those of controls, indicating hepatic injury. Male and female mice receiving 20,000 ppm had hepatic lesions consisting of centrilobular hepatocyte hypertrophy and karyomegaly, multifocal individual hepatocyte necrosis, oval cell proliferation, and periportal Kupffer cells with intracytoplasmic pigment. Males and females receiving 20,000 ppm also had increased numbers of pigmented macrophages within the red pulp of the spleen. 2-YEAR STUDY IN RATS: The doses selected for the 2-year study of C.I. Direct Blue 218 were based on the lower final mean body weights and the occurrence of hepatic lesions in the 20,000 ppm groups in the 13-week study. Groups of 60 male and 60 female rats were fed diets containing 0, 1,000, 3,000, or 10,000 ppm C.I. Direct Blue 218 for 103 weeks. Nine or 10 rats from each group were evaluated after 15 months. Survival, Body Weights, Feed and Compound Consumption, and Clinical Findings: Survival of female rats receiving 10,000 ppm was slightly, but not significantly, lower than that of the controls. Mean body weights of male and female rats in the 10,000 ppm groups were approximately 5% to 14% lower than those of the controls after week 15, and the final mean body weights of male and female rats at this level were 11% and 9% lower than those of the controls, respectively. Feed consumption by exposed male and female rats was similar to that by the controls and was estimated to deliver daily doses of 40, 120, and 440 mg dye/kg body weight to males and 50, 140, and 470 mg/kg to females. No chemical-related clinical signs of toxicity were noted. Hematology and Clinical Chemistry: The hematocrit, hemoglobin, mean erythrocyte volume, and mean erythrocyte hemoglobin values in 10,000 ppm female rats were significantly lower than those of controls, while in males only the mean erythrocyte hemoglobin value was significantly lower. Serum levels of alanine aminotransferase and sorbitol dehydrogenase in male and female rats receiving 10,000 ppm were significantly higher than those of the controls at the 15-month interim evaluation. Pathology Findings: Squamous cell papillomas of the oral mucosa (pharynx) occurred in five males receiving 10,000 ppm but not in the lower exposure groups or in controls. A squamous cell carcinoma occurred in one 10,000 ppm male and a benign basosquamous tumor was observed in another. The incidence of oral mucosal neoplasms in the 10,000 ppm males was significantly greater than that in controls and exceeded the range observed in untreated historical controls (lO/l,253, 0.8%; range 0%-4%). These neoplasms were considered chemical related. Administration of C.I. Direct Blue 218 to rats produced significantly increased incidences of forestomach basal cell hyperplasia in males receiving 3,000 or 10,000 ppm (0 ppm, 0/50; 1,000 ppm, 2/50; 3,000 ppm, 10/50;10,000 ppm, 19/50) and in females receiving 10,000 ppm (1/50, 1/49, 5/50, 11/49). Further, there were marginal increased incidences of focal squamous hyperplasia in the 3,000 and 10,000 ppm males (1/50,1/50, 6/50, 4/50). Squamous cell papillomas of the forestomach were seen in two 3,000 ppm males and in one 10,000 ppm male; no papillomas were observed in the controls. A squamous cell carcinoma was also seen in one 3,000 ppm male. Because of the uncommon occurrence of forestomach neoplasms in untreated control male rats (4/1,253, 0.3%; range 0%-2%) and the slight increase in the incidence of focal hyperplasia, these neoplasms may have been chemical related. The incidence of uterine endometrial stromal polyps in each exposed group of female rats was significantly greater than that of the controls (1/50,12/50,10/50, 10/50). Because the incidences in the exposed groups did not increase in a dose-related manner and the incidence in the controls was unusually low (historical incidence: 205/1,251,16.4%; range 2%-30%), the higher incidence of stromal polyps in the exposed groups was not considered chemical related. 2-YEAR STUDY IN MICE: The dose selection for the 2-year study was based on the lower final mean body weights and the liver lesions observed at the 20,000 ppm level in the 13-week study. Groups of 60 male and 60 female mice were fed diets containing 0, 1,000, 3,000, or 10,000 ppm C.I. Direct Blue 218 for 103 weeks. Nine or 10 mice from each exposure group were evaluated after 15 months. Survival, Body Weights, Feed and Compound Consumption, and Clinical Findings: Survival of exposed male and female mice was similar to that of the controls. Mean body weights of male and female mice receiving 10,000 ppm were 10% to 29% lower than those of the controls during most of the study, and the final mean body weights in these groups were 19% lower than that of the controls for males and 27% lower than that of the controls for females. Feed consumption by exposed mice was similar to that by controls and the diets were estimated to deliver daily doses of approximately 120, 360, and 1,520 mg of dye/kg body weight to males and 140, 470, and 2,050 mg/kg to females. No chemical-related clinical signs of toxicity were noted. Hematology and Clinical Chemistry: Hematocrit, hemoglobin, and mean erythrocyte volume values in males and females receiving 10,000 ppm were significantly lower than those of the controls. Serum levels of alanine aminotransferase and/or sorbitol dehydrogenase values in male and female mice that received 10,000 ppm were significantly higher than those of controls, which is consistent with hepatocellular damage. Pathology Findings: The administration of C.I. Direct Blue 218 to mice produced significantly increased incidences of hepatocellular adenoma (0 ppm, 16/50; 1,000 ppm, 19/50; 3,000 ppm, 17/50; 10,000 ppm, 40/50) and hepatocellular carcinoma (7/50, 3/50, 8/50,17/50) in males receiving 10,000 ppm, and a significantly increased incidence of hepatocellular adenoma in females receiving 3,000 or 10,000 ppm (7/49, 12/50, 17/49, 41/49). In females that received 10,000 ppm, the incidence of hepatocellular carcinoma was marginally increased. Consistent with these findings, the incidence of hepatocellular foci of cytologic alteration, a preneoplastic lesion, was also increased in males and females in the 10,000 ppm groups. The increased incidences of hepatocellular foci, adenomas, and carcinomas were considered chemical related. Uncommon renal tubule neoplasms also occurred at low incidences in male mice receiving C.I. Direct Blue 218, but not in controls. Renal tubule adenomas were seen in two males receiving 1,000 ppm, one male receiving 3,000 ppm, and one male receiving 10,000 ppm. A renal tubule carcinoma was also seen in one male that received 1,000 ppm. Because renal tubule neoplasms are uncommon in male mice (4/1,366, 0.3%; range 0%-2%), these neoplasms may have been chemical related. Carcinomas of the small intestine occurred in four male mice receiving 10,000 ppm. One was observed at the 15-month interim evaluation, while the other three were observed in mice at the end of the study. One control male mouse also had a carcinoma of the small intestine. Because of the uncommon occurrence of small intestine neoplasms in untreated male mice (12/1,374, 0.9%; range 0%-4%), the slightly higher incidence of these neoplasms in males receiving 10,000 ppm may have been chemical related. Carcinomas of the small intestine also occurred in one 3,000 ppm and one 10,000 ppm female, but the low incidences precluded drawing an association with chemical administration. GENETIC TOXICOLOGY: C.I Direct Blue 218 was not mutagenic in Salmonella typhimurium strains TA98, TA100, TA1535, or TA1537 tested with and without exogenous metabolic activation (S9). It was also tested in a modified Salmonella test protocol which employed reductive metabolism supplied by flavin mononucleotide or rat cecal bacteria, followed by oxidative metabolism; results of this test using strain TA1538 were also negative. C.I. Direct Blue 218 induced a small but significant increase in sister chromatid exchanges in Chinese hamster ovary cells at the highest dose tested without S9. No increase in chromosomal aberrations were observed in Chinese hamster ovary cells with or without S9. C.I. Direct Blue 218 did not induce sex-linked recessive lethal mutations in germ cells of male Drosophila melanogaster. CONCLUSIONS: Under the conditions of these 2-year feed studies, there was some evidence of carcinogenic activity of C.I. Direct Blue 218 in male F344/N rats based on the occurrence of pharyngeal neoplasms. Squamous cell neoplasms of the forestomach may have been chemical related. There was no evidence of carcinogenic activity of C.I Direct Blue 218 in female F344/N rats given 1,000, 3,000, or 10,000 ppm. There was clear evidence of carcinogenic activity of C.I. Direct Blue 218 in male and female B6C3F1 mice based on increased incidences of hepatocellular adenomas and carcinomas. The occurrence of a few neoplasms of the kidney and small intestine in male mice may have been related to C.I. Direct Blue 218 treatment. The administration of C.I. Direct Blue 218 produced an increased incidence of forestomach basal cell hyperplasia in rats and hepatocellular foci of cytologic alteration in mice. Synonyms: cuprate(4-), [mu-[(3,3'-dihydroxy[1,1'-biphenyl]-4,4'-diyl)bis[5-amino-4-hydroxy- 2,7-naphthalnedisulfonato]](8-)]]di-, tetrasodium; copper, [tetrahydrogen-3,3'-[(3,3'-dihydroxy-4,4'-biphenylylene)bis(azo)]bis [5-amino-4-hdroxy-2,7-naphthalenedisulfonato](4-)]di-, tetrasodium salt; 1-naphthol-3,6-disulfonic acid, 2,2'-(3,3'-dihydroxy-4,4'-biphenylylenebisazo)bis [8-amino-, dicopper deriv., tetrasodium salt
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OBJECTIVES: This study describes up-to-date cancer incidence and survival in Italian paediatric and adolescent patients, based on data collected by the network of Italian cancer registries (AIRTUM). It updates the monograph published on the same topic in 2008. The main objective of this monograph is to present the statistics according to standard rigorous epidemiological methods and disseminate them to a wide range of readers, including the lay public. Given the deep impact of the 2008 monograph on the general public, in this update we complement descriptive statistics with additional data and commentaries on issues of importance for public health, in order to provide unambiguous criteria on how to interpret the statistics. The study is the result of the collaboration between AIRTUM and AIEOP (Italian Association of Paediatric Haematology and Oncology) with contributions from interested parties, including representatives of parent associations. The monograph is divided into three parts. The first part presents incidence rates, survival probabilities, and time trends, by sex, age, geographical area, and cancer site or type, by means of tables and graphs as in the previous monograph, to facilitate direct comparisons. Four articles summarize and comment the results. The second part uses data from AIRTUM and AIEOP to outline patient management and health care issues; it includes estimates of the number of new cases in the next decade and of young adults living after a paediatric cancer diagnosis. Health organizational aspects of treatment services for paediatric patients, based on the AIEOP database, are also discussed, along with long-term complications in cured patients. The third section describes the changes in mortality trends due to improving therapies and healthcare services, and discusses risk factors and prevention of childhood cancer, late adverse events in cured patients, and other related issues. MATERIAL AND METHODS: Data herein presented were provided by AIRTUM population-based cancer registries, covering 47%of the Italian population below age 20 years, in the period 2003-2008. Quality of cancer registration in Italy is elevated, with high proportions of microscopically verified diagnoses (91%in the 0-14 years age group and 96% between 15 and 19 years of age) and a very small proportion of cases collected through death certificate only (0.1%).The proportion of cases in diagnostic groups XI (other malignant epithelial neoplasms) and XII (other and unspecified neoplasms) of the International Classification for Childhood Cancer (ICCC), based on the third revision of the International Classification of Diseases for Oncology (ICD-O-3), were 7.0% in the 0-14 years age group and 26.0%in the 15-19 years age group.The ratio between mortality and incidence was 17.7% in both children and adolescents. Detailed results are presented in 24 fact sheets for the 12 major ICCC-3 diagnostic groups and 10 sub-groups of special interest; the series is completed by a sheet on all malignant tumours and one on all tumours including non-malignant neoplasms of the central nervous system. All sheets include results for three age groups (0-14, 15-19, and 0-19 years) and are followed by two commentaries on incidence in the recent period, one on trends and the other on survival. Incidence rates were age-standardized on the European population and presented per million children. Incidence rates are also presented by age group, sex, and geographical area. Incidence trends were evaluated for two periods, 1988-2008 and 1998-2008, using estimated annual percent changes, and survival estimates were calculated by age and period. Indicators and corresponding 95% confidence intervals are shown in forms of graphics and tables at the end of the monograph and online at http://www.registri-tumori.it. Geographical analyses were conducted rearranging cancer registries into four macroareas (North-West, North-East, Centre, and South and Islands). Age groups were the same used in descriptive studies on children worldwide (0, 1-4, 5-9, 10- 14 years for paediatric tumours and 15-19 years for adolescents). Incidence trend analyses included cancer registries with three or more years of registration in the 5-year period, using Poisson regression models. Observed survival was computed according to the Kaplan-Meier method. The estimate of expected cases in the next decade was based on observed incidence rates in the most recent period, extended to the Italian estimated population of children and adolescents in the periods 2011-2015 and 2016-2020. The AIEOP database (Modello 1.01) allowed us to compare the number of patients treated and followed-up in specialized centres with expected cases based on AIRTUM estimates. The AIEOP database also provided information regarding health care migration throughout Italian regions and the number of foreign (immigrated) children treated in Italian AIEOP centres. RESULTS: In the period 2003-2008, 31 cancer registries reported 4,473 incident malignant neoplasms, 2,855 in children and 1,618 in adolescents. Cancer incidence rates were 164 cases per million in children aged 14 years or below and 269 cases per million in patients aged 15-19 years. Limited geographical variations emerged. In children (0-14 years) a significant increase in malignant cancer incidence was observed until 1997 (APC: +3.2%), followed by a plateau (APC: -1.1%not statistically significant).Until the late Nineties, a statistically significant increase was also observed in the incidence of all leukaemias in males (APC: +5.7%), lymphoid leukaemias (APC: +5.6%), representing 80% of all leukaemias, Hodgkin and non- Hodgkin lymphomas (APC: +6.3%). A significant decrease emerged for lymphoid leukaemia starting in 1995 (APC: -1.9%), while no substantial change in cancer incidence rates was observed in the last decade of observation for all malignant neoplasms and lymphomas. In addition, no variation emerged for malignant (according to the most recent classification) central nervous system (CNS) neoplasms, while an annual increase of 1.8% (significant) was observed in the period 1988-2008, when non-malignant tumours were included. Increases in cancer incidence were observed throughout the study period for neuroblastoma (APC: +1.9%) and epithelial tumours or melanoma (APC: +4.1%). In the period 1998-2008, in addition to lymphoid leukaemias, a significant decrease was observed for all malignant neoplasms, lymphomas in girls, CNS tumours (males and females), and renal tumours in girls, while no increases were observed in this age group. In adolescents (15-19 years) between 1988 and 2008, a significant increase in incidence rates was observed (APC: +2.0%) for all malignant neoplasms, all lymphomas (APC: +2.9%; in particular Hodgkin lymphoma, APC: +3.6%), thyroid cancer (APC: +6.1%), and melanoma (APC: +8.1%). Conversely, lymphoid leukaemia is the only neoplasm showing a long-term decrease in adolescents. Recent trends (1998-2008) confirm the long-term increases only for all malignant neoplasms in girls and thyroid cancer (APC: +7.9%, boys and girls), while a decrease in bone tumour incidence emerged in girls, albeit based only on 46 cases. Cancer mortality in children showed a persistent decrease for all neoplasms and even for more frequent cancer sites or types, and mortality rates for cancer were three-fold higher in the early Seventies than in 2008. In addition, five-year survival after cancer diagnosis increased in the last three decades and was still increasing in the period 2003- 2008, reaching 82% in children and 86% in adolescents. In the period 2008-2010, 4,488 children (0-14 years) were treated in one of the AIEOP clinical centres and we estimate, based on the above-presented incidence rates, that they represented 92% of all cancer cases in Italy. However, in adolescents, the proportion of patients treated in AIEOP centres was only 25%. A migration of patients living in the South of Italy to Central and Northern Italy emerged from AIEOP information. The expected number of cancer cases in children aged between 0 and 14 years of age is approximately 7,000 in the period 2016- 2020, while the corresponding figure for adolescents between 15 and 19 years of age is 4,000, with no relevant variation in comparison with the previous five-year period. COMMENTS: The present findings update descriptive cancer epidemiology in children and adolescents in Italy based on data provided by an extensive network of general and specialized population-based cancer registries. Data obtained from cancer registries are supplemented by additional information collected by specialized clinical AIEOP centres and mortality reports collected by the National Institute of Statistics (ISTAT). Incidence rates reported in Italy were slightly higher in comparison to other developed Countries, but relatively consistent between different Italian areas. Our results also showed that the significant increase in cancer incidence observed until the end of Nineties has halted, with the exception solely of thyroid cancer in adolescents. Efficacy of therapeutic protocols has improved constantly since the Seventies, and recent findings confirm this trend in all age groups and, in particular, for rarer tumours and cancer types that have very poor prognosis. Findings derived from cross-analysis with AIEOP data suggest that it is possible to further improve the efficiency of our healthcare system, in particular for adolescents; migration can be reduced with a more rational use of hospitals throughout Italy.
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OBJECTIVE: The objective of this review was to assess the safety and effectiveness of metal on metal (MOM) hip resurfacing arthroplasty for young patients compared with that of total hip replacement (THR) in the same population. CLINICAL NEED: Total hip replacement has proved to be very effective for late middle-aged and elderly patients with severe degenerative diseases of the hips. As indications for THR began to include younger patients and those with a more active life style, the longevity of the implant became a concern. Evidence suggests that these patients experience relatively higher rates of early implant failure and the need for revision. The Swedish hip registry, for example, has demonstrated a survival rate in excess of 80% at 20 years for those aged over 65 years, whereas this figure was 33% by 16 years in those aged under 55 years. Hip resurfacing arthroplasty is a bone-conserving alternative to THR that restores normal joint biomechanics and load transfer. The technique has been used around the world for more than 10 years, specifically in the United Kingdom and other European countries. THE TECHNOLOGY: Metal-on-metal hip resurfacing arthroplasty is an alternative procedure to conventional THR in younger patients. Hip resurfacing arthroplasty is less invasive than THR and addresses the problem of preserving femoral bone stock at the initial operation. This means that future hip revisions are possible with THR if the initial MOM arthroplasty becomes less effective with time in these younger patients. The procedure involves the removal and replacement of the surface of the femoral head with a hollow metal hemisphere, which fits into a metal acetabular cup. Hip resurfacing arthroplasty is a technically more demanding procedure than is conventional THR. In hip resurfacing, the femoral head is retained, which makes it much more difficult to access the acetabular cup. However, hip resurfacing arthroplasty has several advantages over a conventional THR with a small (28 mm) ball. First, the large femoral head reduces the chance of dislocation, so that rates of dislocation are less than those with conventional THR. Second, the range of motion with hip resurfacing arthroplasty is higher than that achieved with conventional THR. A variety of MOM hip resurfacing implants are used in clinical practice. Six MOM hip resurfacing implants have been issued licences in Canada. REVIEW STRATEGY: A search of electronic bibliographies (OVID Medline, Medline In-Process and Other Non-Indexed Citations, Embase, Cochrane CENTRAL and DSR, INAHTA) was undertaken to identify evidence published from Jan 1, 1997 to October 27, 2005. The search was limited to English-language articles and human studies. The literature search yielded 245 citations. Of these, 11 met inclusion criteria (9 for effectiveness, 2 for safety). The result of the only reported randomized controlled trial on MOM hip resurfacing arthroplasty could not be included in this assessment, because it used a cemented acetabular component, whereas in the new generation of implants, a cementless acetabular component is used. After omitting this publication, only case series remained. SUMMARY OF FINDINGS: HEALTH OUTCOMES: The Harris hip score and SF-12 are 2 measures commonly used to report health outcomes in MOM hip resurfacing arthroplasty studies. Other scales used are the Oxford hip score and the University of California Los Angeles hip score. The case series showed that the mean revision rate of MOM hip resurfacing arthroplasty is 1.5% and the incidence of femoral neck fracture is 0.67%. Across all studies, 2 cases of osteonecrosis were reported. Four studies reported improvement in Harris hip scores. However, only 1 study reported a statistically significant improvement. Three studies reported improvement in SF-12 scores, of which 2 reported a significant improvement. One study reported significant improvement in UCLA hip score. Two studies reported postoperative Oxford hip scores, but no preoperative values were reported. None of the reviewed studies reported procedure-related deaths. Four studies reported implant survival rates ranging from 94.4% to 99.7% for a follow-up period of 2.8 to 3.5 years. Three studies reported on the range of motion. One reported improvement in all motions including flexion, extension, abduction-adduction, and rotation, and another reported improvement in flexion. Yet another reported improvement in range of motion for flexion abduction-adduction and rotation arc. However, the author reported a decrease in the range of motion in the arc of flexion in patients with Brooker class III or IV heterotopic bone (all patients were men). SAFETY OF METAL-ON-METAL HIP RESURFACING ARTHROPLASTY: There is a concern about metal wear debris and its systemic distribution throughout the body. Detectable metal concentrations in the serum and urine of patients with metal hip implants have been described as early as the 1970s, and this issue is still controversial after 35 years. Several studies have reported high concentration of cobalt and chromium in serum and/or urine of the patients with metal hip implants. Potential toxicological effects of the elevated metal ions have heightened concerns about safety of MOM bearings. This is of particular concern in young and active patients in whom life expectancy after implantation is long. Since 1997, 15 studies, including 1 randomized clinical trial, have reported high levels of metal ions after THR with metal implants. Some of these studies have reported higher metal levels in patients with loose implants. ADVERSE BIOLOGICAL EFFECTS OF COBALT AND CHROMIUM: Because patients who receive a MOM hip arthroplasty are shown to be exposed to high concentrations of metallic ions, the Medical Advisory Secretariat searched the literature for reports of adverse biological effects of cobalt and chromium. Cobalt and chromium make up the major part of the metal articulations; therefore, they are a focus of concern. RISK OF CANCER: To date, only one study has examined the incidence of cancer after MOM and polyethylene on metal total hip arthroplasties. The results were compared to that of general population in Finland. The mean duration of follow-up for MOM arthroplasty was 15.7 years; for polyethylene arthroplasty, it was 12.5 years. The standardized incidence ratio for all cancers in the MOM group was 0.95 (95% CI, 0.79-1.13). In the polyethylene on metal group it was 0.76 (95% CI, 0.68-0.86). The combined standardized incidence ratio for lymphoma and leukemia in the patients who had MOM THR was 1.59 (95% CI, 0.82-2.77). It was 0.59 (95% CI, 0.29-1.05) for the patients who had polyethylene on metal THR. Patients with MOM THR had a significantly higher risk of leukemia. All patients who had leukemia were aged over than 60 years. COBALT CARDIOTOXICITY: EPIDEMIOLOGICAL STUDIES OF MYOCARDIOPATHY OF BEER DRINKERS: An unusual type of myocardiopathy, characterized by pericardial effusion, elevated hemoglobin concentrations, and congestive heart failure, occurred as an epidemic affecting 48 habitual beer drinkers in Quebec City between 1965 and 1966. This epidemic was directly related the consumption of a popular beer containing cobalt sulfate. The epidemic appeared 1 month after cobalt sulfate was added to the specific brewery, and no further cases were seen a month after this specific chemical was no longer used in making this beer. A beer of the same name is made in Montreal, and the only difference at that time was that the Quebec brand of beer contained about 10 times more cobalt sulphate. Cobalt has been added to some Canadian beers since 1965 to improve the stability of the foam but it has been added in larger breweries only to draught beer. However, in small breweries, such as those in Quebec City, separate batches were not brewed for bottle and draught beer; therefore, cobalt was added to all of the beer processed in this brewery. In March 1966, a committee was appointed under the chairmanship of the Deputy Minister of Health for Quebec that included members of the department of forensic medicine of Quebec's Ministry of Justice, epidemiologists, members of Food and Drug Directorate of Ottawa, toxicologists, biomedical researchers, pathologists, and members of provincial police. Epidemiological studies were carried out by the Provincial Ministry of Health and the Quebec City Health Department. The association between the development of myocardiopathy and the consumption of the particular brand of beer was proven. The mortality rate of this epidemic was 46.1% and those who survived were desperately ill, and recovered only after a struggle for their lives. Similar cases were seen in Omaha (Nebraska). The epidemic started after a cobalt additive was used in 1 of the beers marketed in Nebraska. Sixty-four patients with the clinical diagnosis of alcoholic myocardiopathy were seen during an 18-month period (1964-1965). Thirty of these patients died. The first patient became ill within 1 month after cobalt was added to the beer, and the last patient was seen within 1 month of withdrawal of cobalt. A similar epidemic occurred in Minneapolis, Minnesota. Between 1964 and 1967, 42 patients with acute heart failure were admitted to a hospital in Minneapolis, Minnesota. Twenty of these patients were drinking 6 to 30 bottles per day of a particular brand of beer exclusively. The other 14 patients also drank the same brand of beer, but not exclusively. The mortality rate from the acute illness was 18%, but late deaths accounted for a total mortality rate of 43%. Examination of the tissue from these patients revealed markedly abnormal changes in myofibrils (heart muscles), mitochondria, and sarcoplasmic reticulum. In Belgium, a similar epidemic was reported in 1966, in which, cobalt was used in some Belgian beers. (ABSTRACT TRUNCATED)
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