Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0023380 (lethargy)
5,697 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 10-year-old, male beagle was presented for lethargy, anorexia, and straining to urinate. A mass was palpated in the caudal abdomen in the area of the bladder. Abdominal radiography revealed a gas-filled mass in the caudoventral abdominal quadrant. Subsequent positive-contrast cystography revealed that the mass was caudal to the bladder. Abdominal exploratory celiotomy resulted in the drainage of a prostatic abscess containing gas. The histopathological diagnosis of the prostate was a poorly differentiated tubular carcinoma with necrosis. To the authors' knowledge, this article is the first report of an emphysematous prostatitis in a dog.
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PMID:Emphysematous prostatitis and carcinoma in a dog. 1222 33

This paper outlines methods of therapy utilizing newer combinations of estrogens and progestins. The specific agent and length of treatment depends on the extent of disease, severity of symptoms, presence of infertility and response to pseudopregnancy. Structural formulas for 19 synthetic preparations are shown. Of 36 patients with proven endometriosis in which pseudopregnancy was induced by the use of these newer agents, satisfactory objective in 82%. Pregnancy occurred later in 6 of 10 patients who had previously been infertile and wished to become pregnant. The optimum maintenance dose is 4-6 mg of chlormadinone acetate or ethnodiol diacetate with .2 mg of mestranol and 5-10 mg of megestrol acetate with .2 mg of ethniyl estradiol. Dosage is increased only when break through bleeding occurs. Gain in weight occurred in almost 1/2 of the patients. The decidual reaction was just as great as that produced formerly by large doses of Enovid. In a more recent study 60 patients were treated with Norlestrin, 20 with Lyndiol and 20 with Ovral. Satisfactory objective and subjective remissions were obtained in 89%. Pregnancy has occurred subsequently in 17 to 43 patients who desired pregnancy. All infants have been normal. The optimum maintenance doses seem to be 10-15 mg if Norlestrin, 2.5-5 mg Lyndiol or .5-1 mg of Ovral. The most common side effect was weight gain in 35%. These agents may be used prior to conservative surgery in order to soften areas of fibrotic endometriosis or to pinpoint areas otherwise overlooked. The length of preoperative treatment depends on the extent of disease, 6 weeks being usual. The indication for prolonged pseudopregnancy is recurrent endometriosis following surgery, also proven vaginal endometriosis. Subsequent to conservative surgery, 12 to 24 weeks of therapy are given in order to inhibit ovulation and prevent reactivation of any remaining areas of endometriosis. Tables show commercial combinations and dosage regimens. Nausea, break through bleeding, breast soreness, acne, water retention, isoninia, irritability, lethargy, headaches or development of leiomyomas are side effects to be dealt with by modifying the treatment. Thromboembolic disease has not been a complication in over 500 patients but should be looked for as it has been reported by others. The effect of long-term use of these drugs has been shown to be entirely reversible without subsequent deleterious effects. Severe hepatic disease or previous mammary carcinoma are contraindications. Excessive side effects may necessitate other treatment but the newer drugs reduce this chance. The diagnosis of endometriosis should first be proven.
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PMID:Newer synthetic progestins for the treatment of endometriosis. 1233 29

2-Butoxyethanol is a member of a family of ethylene glycol monoalkyl ethers. It is used extensively as a solvent in surface coatings such as lacquers, enamels, varnishes, and latex paint; in paint thinners, paint stripping formulations, and inks; and in degreasers and industrial and household cleaners. 2-Butoxyethanol was nominated for study because of its widespread use in industrial and consumer applications, the potential for exposure to workers and the general population, and the absence of chronic toxicity data. Male and female F344/N rats and B6C3F1 mice were exposed to 2-butoxyethanol (greater than 99% pure) by inhalation (primary route of human exposure) for 14 weeks or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, cultured Chinese hamster ovary cells, and the bone marrow of male F344/N rats and B6C3F1 mice. 14-WEEK STUDY IN RATS: Groups of 10 male and 10 female rats were exposed to 2-butoxyethanol by inhalation at concentrations of 0, 31, 62.5, 125, 250, or 500 ppm, 6 hours per day, 5 days per week for 14 weeks. One female rat in the 250 ppm group was killed moribund during week 8; four females in the 500 ppm group were killed moribund during week 1 and one during week 5. Final mean body weights of females exposed to 500 ppm were significantly less than those of the chamber controls. Clinical findings included abnormal breathing, pallor, red urine stains, nasal and eye discharge, lethargy, and increased salivation and/or lacrimation. Due to vascular thrombosis and infarction in the tail vertebrae of 500 ppm female rats, the tails became necrotic and either sloughed off or were chewed off. The primary effect on the hematopoietic system was an anemia characterized as macrocytic, normochromic, and regenerative in males exposed to 125 ppm or greater and, to a greater extent, in all exposed groups of females. Compared to the chamber controls, kidney weights of males exposed to 500 ppm and females exposed to 125 ppm or greater and liver weights of males exposed to 250 or 500 ppm and females exposed to 125 ppm or greater were significantly increased, and thymus weights of females exposed to 500 ppm were significantly less. In female rats killed moribund, there was considerable histologic evidence of thrombosis in tissues and organs including the nasal cavity, incisors, liver, lung, and heart. In addition to thrombosis, infarction occurred in the vertebrae of the tail resulting in necrosis and loss of the distal portion of the tail. There were also inflammation, necrosis, and ulceration of the forestomach; necrosis and centrilobular degeneration of the liver; renal tubule degeneration; and atrophy of the spleen and thymus. Exposure-related increases in the incidences of Kupffer cell pigmentation, forestomach inflammation and epithelial hyperplasia, bone marrow hyperplasia, splenic hematopoietic cell proliferation, and renal tubule pigmentation were observed in male and/or female rats surviving to the end of the study. 14-WEEK STUDY IN MICE: Groups of 10 male and 10 female mice were exposed to 2-butoxyethanol by inhalation at concentrations of 0, 31, 62.5, 125, 250, or 500 ppm, 6 hours per day, 5 days per week for 14 weeks. Two male and two female mice exposed to 500 ppm died and two males and two females were killed moribund during the first 2 weeks of the study. Final mean body weights of 125, 250, and 500 ppm male mice were significantly less than those of the chamber controls. Clinical findings were observed only in 500 ppm males and females that died or were killed moribund and included abnormal breathing, red urine stains, and lethargy. Hematologic evaluation indicated an anemia that was characterized as normocytic, normochromic, and regenerative in mice exposed to 62.5 ppm or greater; the anemia was more pronounced in females. Liver weights of males exposed to 500 ppm were significantly greater than the chamber controls. In mice either dying early or killed moribund, there were inflammation, necrosis, and ulceration of the forestomach; mediastinal pleura and peritoneal inflammationmmation associated with the forestomach lesions; liver necrosis; renal tubule degeneration; atrophy of the spleen, thymus, and mandibular and mesenteric lymph nodes; and degeneration of the testis. Exposure-related increases in the incidences of hematopoietic cell proliferation and hemosiderin pigmentation of the spleen, Kupffer cell hemosiderin pigmentation of the liver, inflammation and epithelial hyperplasia of the forestomach, and renal tubule hemosiderin pigmentation occurred in male and/or female mice surviving to the end of the study. 2-YEAR STUDY IN RATS: Groups of 50 male and 50 female rats were exposed to 2-butoxyethanol by inhalation at concentrations of 0, 31.2, 62.5, or 125 ppm, 6 hours per day, 5 days per week for 104 weeks. For hematology and bone marrow analyses, additional groups of 27 male and 27 female rats were exposed to 0, 62.5, or 125 ppm for evaluation at 3, 6, and 12 months and nine male and nine female rats were exposed to 31.2 ppm for evaluation at 3 (hematology only) and 6 months. Survival and Body Weights: Survival of exposed male and female rats was similar to the chamber control groups. The mean body weights of females exposed to 125 ppm were generally less than the chamber control group. Hematology and Bone Marrow Cellularity: The most consistent exposure-related effect on the hematopoietic system was an exposure concentration-related mild macrocytic, normochromic, regenerative anemia present at 3, 6, and 12 months, with females more affected than males. Significant increases in bone marrow cellularity and decreases in the myeloid/erythroid ratio relative to the chamber controls were observed at all time points in females exposed to 125 ppm, and a decrease in the myeloid/erythroid ratio was observed in males exposed to 125 ppm at 12 months. Pathology Findings: The incidence of benign or malignant pheochromocytoma (combined) of the adrenal medulla in females exposed to 125 ppm was not significantly increased compared to the chamber controls but exceeded the historical control range. Exposure-related increases in the incidences of hyaline degeneration of the olfactory epithelium and Kupffer cell pigmentation of the liver were observed in male and female rats. 2-YEAR STUDY IN MICE: Groups of 50 male and 50 female mice were exposed to 2-butoxyethanol by inhalation at concentrations of 0, 62.5, 125, or 250 ppm, 6 hours per day, 5 days per week for 104 weeks. For hematology and bone marrow analyses, additional groups of 30 male and 30 female mice were exposed to 0, 62.5, 125, or 250 ppm for evaluation at 3, 6, and 12 months. Survival and Body Weights: Survival of male mice exposed to 125 or 250 ppm was significantly less than that of the chamber control group. The mean body weights of exposed males were generally less than those of the chamber control group during the last 6 months of the study. The mean body weights of exposed female mice were less than those of the chamber control group; the reductions were greater and occurred earlier than those observed in males. Hematology: The most consistent exposure-related effect on the hematopoietic system was an exposure concentration-related minimal normocytic, normochromic, regenerative anemia present at 3, 6, and 12 months, with females affected slightly more than males. Pathology Findings: In females exposed to 250 ppm, incidences of forestomach squamous cell papilloma and squamous cell papilloma or carcinoma (combined) were significantly increased relative to the chamber controls, and these incidences exceeded the ranges in historical chamber controls. In 2-butoxyethanol exposed males, there were possible exposure-related increases in the incidences of squamous cell papilloma of the forestomach, although the increases were not significant and the incidences were within the historical control range for chamber controls. Accompanying these neoplasms in females and, to a lesser extent, in males were exposure-related increases in the incidences of ulcer and epithelial hyperplasia of the forestomach. In male mice exposed to 250 ppm, the incidence of hemangiosarcoma of the liver was significantly increased relative to chamber controls and exceeded the range in historical controls; in addition, there were possible exposure-related increases in the incidence of hepatocellular carcinoma. Incidences of hemosiderin pigmentation in the Kupffer cells were significantly increased in 125 and 250 ppm males and all exposed groups of females. The incidences of splenic hematopoietic cell proliferation and hemosiderin pigmentation were generally increased in males and females, and the incidences of bone marrow hyperplasia were increased in males. The incidences of hyaline degeneration of the olfactory and respiratory epithelia of the nose were increased in female mice. GENETIC TOXICOLOGY: 2-Butoxyethanol did not induce mutations in any of the S. typhimurium strains tested, with or without induced hamster or rat liver S9. 2-Butoxyethanol induced cycle delay but did not induce either sister chromatid exchanges or chromosomal aberrations in cultured Chinese hamster ovary cells with or without S9. 2-Butoxyethanol did not induce micronuclei in bone marrow cells of male rats or mice administered the chemical by intraperitoneal injection three times at 24-hour intervals. CONCLUSIONS: Under the conditions of these 2-year inhalation studies, there was no evidence of carcinogenic activity of 2-butoxyethanol in male F344/N rats exposed to 31.2, 62.5, or 125 ppm. There was equivocal evidence of carcinogenic activity of 2-butoxyethanol in female F344/N rats based on the increased combined incidences of benign or malignant pheochromocytoma (mainly benign) of the adrenal medulla. There was some evidence of carcinogenic activity of 2-butoxyethanol in male B6C3F1 mice based on increased incidences of hemangiosarcoma of the liver. A marginal increase in the incidences of forestomach squamous cell papilloma and an increase in the incidences of hepatocellular carcinoma may have been exposure related. There was some evidence of carcinogenic activity of 2-butoxyethanol in female B6C3F1 mice based on increased incidences of fore stomach squamous cell papilloma or carcinoma (mainly papilloma). Increased incidences of forestomach neoplasms in male and female mice occurred in groups in which ulceration and hyperplasia were also present. Exposure to 2-butoxyethanol caused a mild regenerative anemia and effects secondary to the anemia. Synonyms: 2-Butoxy-1-ethanol; m-butyl ether; butyl glycol; ethylene glycol monobutyl ether Trade name: Butyl Cellosolve
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PMID:NTP Toxicology and Carcinogenesis Studies 2-Butoxyethanol (CAS NO. 111-76-2) in F344/N Rats and B6C3F1 Mice (Inhalation Studies). 1257 79

Primidone is used alone or with other anticonvulsants in the control of grand mal, psychomotor, and focal epileptic seizures. It may control grand mal seizures refractory to other anticonvulsant therapy. Primidone was nominated by the National Cancer Institute for 2-year toxicology and carcinogenicity studies due to its human use as an anticonvulsant. Male and female F344/N rats and B6C3F1 mice received primidone (greater than 99% pure) in feed for 14 days, 14 weeks, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, cultured Chinese hamster ovary cells, and mouse bone marrow cells. 14-DAY STUDY IN RATS: Five male and five female rats were exposed to 0, 1,250, 2,500, 5,000, 10,000 or 20,000 ppm primidone (equivalent to average daily doses of approximately 120, 240, 500, 970, or 1,100 mg primidone/kg body weight to males and 120, 240, 500, or 900 mg/kg to females) in feed for 14 days. All 20,000 ppm females died before the end of the study as did one 10,000 ppm male and two 20,000 ppm males. The mean body weights of 10,000 ppm males and females and 20,000 ppm males were significantly less than those of the controls. Feed consumption by all exposed rats was generally similar to that by the controls. Males and females in the 10,000 and 20,000 ppm groups were observed to have eye discharge, ataxia, and abnormal posture and were thin and lethargic. 14-DAY STUDY IN MICE: Five male and five female mice were exposed to 0, 625, 1,250, 2,500, 5,000 or 10,000 ppm primidone (equivalent to average daily doses of approximately 100, 200, 400, or 800 mg/kg body weight to males and 100, 250, 500, or 900 mg/kg to females) in feed for 14 days. All mice in the 10,000 ppm groups and one male and one female mouse in the 5,000 ppm groups died on day 3 of the study. The mean body weights of mice in the 625, 1,250, 2,500, and 5,000 ppm groups were similar to those of the controls. Feed consumption by all exposed mice was generally similar to that by the controls. Males and females in the 10,000 ppm groups were observed to have abnormal posture, ataxia, and lethargy. 14-WEEK STUDY IN RATS: Groups of 10 male and 10 female rats were exposed to 0, 300, 600, 1,300, 2,500, or 5,000 ppm primidone (equivalent to average daily doses of approximately 20, 40, 100, 200, or 400 mg/kg) in feed for 14 weeks. All rats survived to the end of the study. The mean body weights of male and female rats in the 2,500 and 5,000 ppm groups were significantly less than those of the controls. Feed consumption by all exposed rats was generally similar to that by the controls. A minimal to mild exposure-related thrombocytosis occurred on day 22 and at week 14 in all exposed groups of male rats and in females in the 1,300 ppm or greater groups. A minimal decrease in hemoglobin concentration occurred in 2,500 and 5,000 ppm male and female rats on day 22 and at week 14. The incidences of centrilobular hepatocyte hypertrophy in male rats exposed to 600 ppm or greater and in female rats exposed to 1,300 ppm or greater were significantly greater than those in the controls. The severity of chronic nephropathy in male rats exposed to 1,300 ppm or greater increased with increasing exposure concentration. 14-WEEK STUDY IN MICE: Groups of 10 male and 10 female mice were exposed to 0, 300, 600, 1,300, 2,500, or 5,000 ppm primidone (equivalent to average daily doses of approximately 50, 100, 200, 400, or 1,000 mg/kg to males and 60, 120, 220, 440, or 1,100 mg/kg to females) in feed for 14 weeks. Three male and two female mice in the 5,000 ppm group died during week 1 of the study. The final mean body weights of all exposed groups were similar to those of the controls. Feed consumption by male mice in the 5,000 ppm group was slightly greater than that by the controls; this may have been due to feed spillage. Male and female mice in the 5,000 ppm groups were ataxic and lethargic. Compared to controls, the estrous cycle lengths of females exposed to 1,300, 2,500, or 5,000 ppm were significantly longer. The liver weights of male and female mice exposed to 600 po 600 ppm or greater were significantly greater than those of the controls. The incidences of centrilobular hepatocyte hypertrophy in all exposed males and in females exposed to 600 ppm or greater and the incidences of cytoplasmic alteration of the adrenal gland and hematopoietic cell proliferation of the spleen in 2,500 and 5,000 ppm males and in 5,000 ppm females were significantly greater than in the controls. 2-YEAR STUDY IN RATS: Groups of 50 male and 50 female F344/N rats were exposed to 0, 600, 1,300, or 2,500 ppm primidone (equivalent to average daily doses of approximately 25, 50, or 100 mg/kg) in feed for 2 years. Survival, Body Weights, and Feed Consumption Survival of the 1,300 and 2,500 ppm males was sig nificantly less than that of the controls. The mean body weights of males and females in the 2,500 ppm groups were less than those of the controls, beginning at week 29 for males and week 17 for females; the mean body weights of 1,300 ppm males and females were less than those of the controls during the second year of the study. Feed consumption by all exposed groups of rats was generally similar to that by the controls. Pathology Findings Male rats exposed to primidone had increased inci dences of thyroid gland follicular cell neoplasms (adenoma and/or carcinoma). All exposed groups of male rats had follicular cell adenomas or carcinomas (combined) at incidences above the historical control range, with the highest incidence in the 1,300 ppm group. Hepatocyte cytoplasmic vacuolation and centrilobular hypertrophy were associated with primidone exposure in male and female rats. These changes were more severe in females than in males and the incidences in all exposed groups of females were significantly greater than those in the controls. Females in the 2,500 ppm group had an increased incidence of hepatocellular eosinophilic foci. In 2,500 ppm males, the incidence of renal tubule hyperplasia was greater than that in the controls in the standard evaluation. Additional hyperplasias were found in the extended evaluation, and the incidences in exposed groups of males were significantly greater than that in the controls. In the extended evaluation, the incidence of renal tubule adenoma in 2,500 ppm males was significantly increased. The incidence of adenoma or carcinoma (combined) in 2,500 ppm males in the combined standard and extended evaluations were marginally increased over those in the controls. Male rats had an exposure-related increase in the severity of chronic nephropathy, which probably accounted for the reduced survival in the 1,300 and 2,500 ppm groups. The incidences of kidney cysts were increased in 1,300 and 2,500 ppm males. Hyperparathyroidism, secondary to the loss of renal function, was present in many exposed male rats. The incidences of parathyroid gland hyperplasia in all groups of exposed males were significantly greater than that in the controls. 2-YEAR STUDY IN MICE: Groups of 50 male and 50 female mice were exposed to dietary levels of 0, 300, 600, or 1,300 ppm primidone (equivalent to average daily doses of approximately 30, 65, or 150 mg/kg to males and 25, 50, or 100 mg/kg to females) in feed for 2 years. Survival, Body Weights, Feed Consumption, and Clinical Findings Survival of the 1,300 ppm males was significantly less than that of the controls. During the second year of the study, the mean body weights of 1,300 ppm male and female mice were less than those of the controls. The final mean body weights of 600 ppm males and females were less than those of the controls. Feed consumption by all exposed groups of mice was similar to that by the controls. During the latter part of the study, a treatment-related increase in the number of animals with swelling of the abdominal area was observed; necropsy revealed that the swelling was due to liver nodules/masses. Pathology Findings The liver was a target organ in both male and female mice. The incidences and multiplicities of hepatocellular neoplasms (hepatocellular adenoma, hepatocellular carcinoma, and hepatoblastoma) in all exposed groups of males and females (except hepatoblastoma in females) were significantly greater than those in the controls. The incidences of hepatocellular adenoma or carcinoma (combined) and hepatocellular adenoma, hepatocellular carcinoma, or hepatoblastoma (combined) in all exposed groups exceeded the historical control ranges in 2-year NTP studies. The incidences of centrilobular hepatocyte hypertrophy were increased in exposed groups of males and females, and the severities increased with increasing exposure concentration. The incidences of cytoplasmic vacuolization were increased in all exposed groups of females and in 300 ppm males. Incidences of eosinophilic focus in all exposed groups of females were significantly greater than those in the controls. Proliferative changes occurred in the thyroid gland in an exposure-related manner in male and female mice. Incidences of follicular cell hyperplasia were increased in all exposed groups of males and in 600 and 1,300 ppm females, but incidences of follicular cell adenomas were increased only in male mice. GENETIC TOXICOLOGY: Primidone was mutagenic in Salmonella typhimurium strain TA1535 in the absence of S9 activation only; no mutagenicity was detected in strain TA98, TA100, or TA1537, with or without S9. Primidone did not induce sister chromatid exchanges or chromosomal aberrations in cultured Chinese hamster ovary cells, with or without S9. The single in vivo study with primidone, a mouse bone marrow micronucleus test, also gave negative results. CONCLUSIONS: Under the conditions of these 2-year feed studies, there was equivocal evidence of carcinogenic activity of primidone in male F344/N rats based on a marginal increase in thyroid gland follicular cell neoplasms, primarily adenomas, and a marginal increase in renal tubule neoplasms. There was no evidence of carcinogenic activity of primidone in female F344/N rats exposed to 600, 1,300, or 2,500 ppm. There was clear evidence of carcinogenic activity of primidone in male B6C3F1 mice based on the increased incidences of hepatocellular neoplasms, and the increased incidence of thyroid gland follicular cell adenomas was also considered to be chemical related. There was clear evidence of carcinogenic activity of primidone in female B6C3F1 mice based on the increased incidences of hepatocellular neoplasms. Exposure of rats to primidone resulted in increased incidences of hepatocyte cytoplasmic vacuolization and centrilobular hypertrophy in males and females and eosinophilic foci in females. The increased severity of nephropathy and increased incidence of renal tubule hyperplasia in male rats were related to primidone exposure. Exposure of male mice to primidone resulted in hepatocyte centrilobular hypertrophy and thyroid gland follicular cell hyperplasia. Exposure of female mice to primidone resulted in hepatocyte centrilobular hypertrophy and cytoplasmic vacuolization, eosinophilic focus, and thyroid gland follicular cell hyperplasia. Synonyms: 5-Aethyl-5-phenyl-hexahydropyrimidin-4,6-dion; 2-deoxyphenobarbital; 2-desoxyphenobarbital; desoxyphenobarbitone; 5-ethyldihydro-5-phenyl-4,6 (1H,5H)-pyrimidinedione; 5-ethylhexahydro-4,6-dioxo-5-phenylphrimidine; 5-ethylhexahydro-5-phenylpyrimidine-4,6-dione; 5-ethyl-5-phenylhexahydropyrimidine-4,6-dione Trade names: Cyral; Hexadiona; Hexamidine; Lepimidin; Lepsiral; Majsolin; Midone; Milepsin; Misodine; Misolyne; Mizodin; Mizolin; Mylepsin; Mylepsinum; Mysedon; Mysoline; Prilepsin; Primacione; Primaclone; Primacone; Primakton; Primadon; Prysoline; Pyrimidone; ROE 101; Sertan
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PMID:NTP Toxicology and Carcinogenesis Studies of Primidone (CAS No. 125-33-7) in F344/N Rats and B6C3F1 Mice (Feed Studies). 1257 87

Isobutyl nitrite is used to a limited extent as an intermediate in the syntheses of aliphatic nitrites. It is also an ingredient of various incenses or room odorizers and is used as a euphoric. The chemical has also been used as a jet propellant and in the preparation of fuels. Isobutyl nitrite was nominated by the Consumer Product Safety Commission to the NTP for toxicology and carcinogenicity studies because of its possible contribution to the high incidence of Kaposi's sarcoma among male homosexual acquired immune deficiency syndrome patients and because of the lack of available data on the potential carcinogenicity of isobutyl nitrite. Male and female F344/N rats and B6C3F1 mice were exposed to isobutyl nitrite (purity of 93% 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, Drosophila melanogaster, and mouse peripheral blood. 16-DAY STUDY IN RATS: Groups of five male and five female F344/N rats were exposed to 0, 100, 200, 400, 600, or 800 ppm (approximately 420, 840, 1,700, 2,500, or 3,300 mg/m(3)) isobutyl nitrite by inhalation for 6 hours per day, 5 days per week for a total of 12 exposures during a 16-day period. All males and females exposed to 600 or 800 ppm and one 400 ppm female died on the first day of the study. Final mean body weights and mean body weight gains of 400 ppm males and females were significantly lower than those of the controls. Clinical findings observed in 400 ppm males and females included ocular discharge, lethargy, hunched posture, and rough coats. Absolute and relative lung weights of all exposed groups of males and of 200 and 400 ppm females were less than those of the controls. Chemical-related hyperplasia of the bronchial epithelium was observed in 200 and 400 ppm males and females and hyperplasia of the nasal turbinate epithelium was observed in rats exposed to 400 ppm or less. Hemosiderin pigmentation was observed in the spleen of 200 and 400 ppm males and females and bone marrow hematopoietic hyperplasia was observed in rats exposed to 400 ppm or less. 16-DAY STUDY IN MICE: Groups of five male and five female B6C3F1 mice were exposed to 0, 100, 200, 400, 600, or 800 ppm (approximately 420, 840, 1,700, 2,500, or 3,300 mg/m(3)) isobutyl nitrite by inhalation for 6 hours per day, 5 days per week for a total of 12 exposures during a 16-day period. Three males and four females exposed to 800 ppm died before the end of the study. Final mean body weights and mean body weight gains of 600 and 800 ppm males and females were significantly lower than those of the controls. Mice exposed to 400 ppm or greater were lethargic and exhibited hunched posture and rough coats. Absolute and relative lung weights of 600 and 800 ppm males and the relative lung weight of 600 ppm females were significantly greater than those of the controls. Chemical-related hyperplasia of the bronchiolar epithelium was observed in all exposed groups of males and females. Lymphocytic atrophy of the spleen and thymus was observed in males and females exposed to 400 ppm or greater. 13-WEEK STUDY IN RATS: Groups of 10 male and 10 female F344/N rats were exposed to 0, 10, 25, 75, 150, or 300 ppm (approximately 42, 105, 315, 630, or 1,260 mg/m(3)) isobutyl nitrite by inhalation for 6 hours per day, 5 days per week for 13 weeks. All rats survived to the end of the study. Final mean body weights and mean body weight gains of 300 ppm males and females were significantly lower than those of the controls, as was the mean body weight gain of 150 ppm females. Clinical findings observed during the study included ruffled fur in 300 ppm males and females, hypoactivity in 300 ppm males, and hyperactivity in 150 and 300 ppm females. A very mild chemical-related methemoglobinemia and anemia occurred in male and female rats in the 75, 150, and 300 ppm groups. Hematopoietic hyperplasia occurred in the bone marrow of all exposed groups of males and females and was considered to be a secondary response to the anemia and methed methemoglobinemia. There was minimal hemosiderin pigment accumulation in the spleens of males and females exposed to 75 ppm or greater, mild to moderate epithelial cell hyperplasia of the nasal mucosa was observed in 300 ppm males and females, and minimal hyperplasia occurred in 150 ppm males and females. Hyperplasia of the bronchial epithelium was observed in 300 ppm males and females. 13-WEEK STUDY IN MICE: Groups of 10 male and 10 female B6C3F1 mice were exposed to 0, 10, 25, 75, 150, or 300 ppm (approximately 42, 105, 315, 630, or 1,260 mg/m(3)) isobutyl nitrite by inhalation for 6 hours per day, 5 days per week for 13 weeks. There were no chemical-related deaths. Final mean body weights and mean body weight gains of 150 and 300 ppm females were significantly less than those of the controls. Final mean body weights and mean body weight gains of exposed groups of males were similar to those of the controls. There were no chemical-related clinical findings. A very mild chemical-related methemoglobinemia occurred in male and female mice in the 150 and 300 ppm groups. A very mild anemia occurred in the 300 ppm groups. In the lung, increased incidences of mild to moderate hyperplasia of the bronchiolar epithelium occurred in males and females exposed to 300 ppm. Minimal hyperplasia occurred in males exposed to 75 ppm or greater and in females exposed to 150 ppm. Minimal epithelial cell hyperplasia of the nasal mucosa was observed in 300 ppm males. Increased hematopoiesis of the spleen, secondary to the hematotoxicity, occurred in males exposed to 75 ppm or greater and in females exposed to 150 or 300 ppm. Increased hemosiderosis of the spleen occurred in males exposed to 300 ppm and in females exposed to 75 ppm or greater. 2-YEAR STUDY IN RATS: Based on the low final mean body weights, anemia, and the mild to moderate nasal mucosal lesions and the hyperplastic bronchial lesions observed in 300 ppm males and females, isobutyl nitrite exposure concentrations selected for the 2-year inhalation study in rats were 37.5, 75, and 150 ppm. Groups of 56 male and 56 female rats were exposed to 0, 37.5, 75, or 150 ppm (equivalent to 0, 158, 315, or 630 mg/m(3)) isobutyl nitrite by inhalation for 6 hours per day, 5 days per week, for 103 weeks. Ten male and 10 female rats from each group were evaluated at 15 months for clinical pathology and histopathology. Survival, Body Weights, Clinical Findings, Hematology, and Clinical Chemistry: Survival rates of exposed groups of rats were greater than those of the controls, and the survival rates of 75 and 150 ppm males were significantly greater than that of the control. Mean body weights of 150 ppm males and females were 3% to 11% lower than those of the controls throughout the course of the study. There were no clinical findings considered to be related to isobutyl nitrite exposure. A very mild methemoglobinemia and anemia occurred in male and female rats exposed to 75 or 150 ppm. Pathology Findings: Incidences of alveolar/bronchiolar adenoma and alveolar/bronchiolar adenoma or carcinoma (combined) occurred with significant positive trends in exposed males and females, and the incidences of these neoplasms in 75 ppm males and in 150 ppm males and females were significantly greater than those in the controls. The incidence of alveolar/bronchiolar carcinoma was significantly greater in 150 ppm male rats than that in the controls. The incidences of alveolar epithelial hyperplasia were also increased in 75 and 150 ppm males and in all exposed groups of females. The incidences of mononuclear cell leukemia in exposed groups of males and females were significantly less than those in the controls. 2-YEAR STUDY IN MICE: Based on the low final mean body weight of 300 ppm females and the mild to moderate bronchiolar hyperplasia observed in 300 ppm males and females, isobutyl nitrite exposure concentrations selected for the 2-year inhalation study in mice were 37.5, 75, and 150 ppm. Groups of 60 male and 60 female mice were exposed to 0, 37.5, 75, or 150 ppm (equivalent to 0, 158, 315, or 630 mg/m(3)) isobutyl nitrite by inhalation for 6 hours per day, 5 days per week, for 103 weeks. As many as 10 male and 10 female mice from each group were evaluated at 15 months for clinical pathology and histopathology. Survival, Body Weights, Clinical Findings, and Hematology and Clinical Chemistry: Survival rates of exposed groups of males were similar to those of the controls. Survival rates of exposed groups of females were greater than those of the controls, and the survival rate in 37.5 ppm females was significantly greater than that of the controls. Mean body weights of exposed groups of males and of 37.5 and 75 ppm females were similar to those of the controls throughout the study. Mean body weights of 150 ppm females were lower than those of the controls from week 20 until the end of the study. There were no biologically significant clinical findings noted in the 2-year study in mice. A very mild methemoglobinemia and anemia occurred in male and female mice exposed to 75 or 150 ppm. Pathology Findings: Incidences of alveolar/bronchiolar adenoma and alveolar/bronchiolar adenoma or carcinoma (combined) occurred with significant positive trends in exposed males and females, and the incidences of these neoplasms were significantly greater than those in the controls in 75 ppm males and in 150 ppm males and females. Incidences of alveolar epithelial hyperplasia were significantly increased in 75 and 150 ppm male and female mice. Thyroid gland follicular cell adenoma occurred with a significant positive trend in male mice; the incidences of thyroid gland follicular cell hyperplasia were increased in all exposed groups of males, and the incidences in males exposed to 37.5 or 150 ppm were significantly greater than those in the controls. Incidences of serous exudate and olfactory epithelium atrophy in the nose of 150 ppm females were significantly greater than those in the controls. Incidences of minimal to mild hemosiderin pigment in the spleen of 75 and 150 ppm male mice were significantly greater than those in the controls. GENETIC TOXICOLOGY: Isobutyl nitrite was found to be mutagenic in vitro and in vivo. It induced base-pair substitution mutations in Salmonella typhimurim strains TA100 and TA1535 and sister chromatid exchanges and chromosomal aberrations in cultured Chinese hamster ovary cells. Positive responses in the S. typhimurium tests required S9 activation, but isobutyl nitrite induced chromosomal effects in cultured Chinese hamster ovary cells with and without S9. In vivo, no induction of sex-linked recessive lethal mutations was noted in the germ cells of male Drosophila melanogaster exposed to isobutyl nitrite via feeding or injection. However, significant increases in micronucleated normochromatic erythrocytes were observed in the peripheral blood of male and female mice treated with isobutyl nitrite for 90 days by inhalation. CONCLUSIONS: Under the conditions of these 2-year inhalation studies, there was clear evidence of carcinogenic activity of isobutyl nitrite in male and female F344/N rats based on the increased incidences of alveolar/bronchiolar adenoma and alveolar/bronchiolar adenoma or carcinoma (combined). There was some evidence of carcinogenic activity of isobutyl nitrite in male and female B6C3F1 mice based on the increased incidences of alveolar/bronchiolar adenoma and alveolar/bronchiolar adenoma or carcinoma (combined) in males and females. The increased incidence of thyroid gland follicular cell adenoma in male mice may have been related to isobutyl nitrite exposure. Exposure of rats and mice to isobutyl nitrite by inhalation for 2 years resulted in increased incidences of alveolar epithelial hyperplasia (male and female rats and mice), thyroid gland follicular cell hyperplasia and splenic hemosiderin pigmentation (male mice), and serous exudate and atrophy of the olfactory epithelium of the nose (female mice). Exposure of rats to isobutyl nitrite by inhalation for 2 years resulted in decreased incidences of mononuclear cell leukemia in males and females.
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PMID:NTP Toxicology and Carcinogenesis Studies of Isobutyl Nitrite (CAS No. 542-56-3) in F344 Rats and B6C3F1 Mice (Inhalation Studies). 1259 27

1-Trans-delta(9)-tetrahydrocannabinol (THC) was nominated by the National Cancer Institute to the NTP for study because it is the major psychoactive component of marijuana and a widely used Schedule I substance. Male and female F344/N rats and B6C3F1 mice received THC (97% pure) in corn oil by gavage for 13 weeks, 13 weeks with a 9-week recovery period, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, cultured Chinese hamster ovary cells, and mouse peripheral blood cells. 13-WEEK STUDY IN RATS: Groups of 10 male and 10 female rats received 0, 5, 15, 50, 150, or 500 mg THC/kg body weight in corn oil by gavage, 5 days per week for 13 weeks. Six male and six female rats receiving 500 mg/kg died before the end of the study. The final mean body weights and weight gains of all dosed groups of males and females, except 5 mg/kg females, were significantly lower than those of the controls. Feed consumption by dosed groups was similar to that by controls. Clinical findings observed during the study included lethargy, sensitivity to touch, convulsions, tremors, and aggressiveness. There were no clinical pathology differences considered to be directly related to the administration of THC. The absolute and relative uterus weights of 50, 150, and 500 mg/kg females were significantly lower than those of the controls. Treatment-related multifocal atrophy was observed in the testes of 150 and 500 mg/kg males; uterine and ovarian hypoplasia observed in 150 and 500 mg/kg females was also considered to be related to THC administration. Based on final mean body weights and mortality observed in the 13-week study, doses selected for the 2-year rat study were 12.5, 25, and 50 mg/kg. 13-WEEK STUDY IN MICE: Groups of 10 male and 10 female mice received 0, 5, 15, 50, 150, or 500 mg THC/kg body weight in corn oil by gavage, 5 days per week for 13 weeks. There were no treatment-related deaths. The final mean body weight and weight gain of 500 mg/kg males were significantly lower than those of the controls. Clinical findings included lethargy and aggressiveness, and both male and female mice in all dosed groups were easily startled. There were no absolute or relative organ weight differences, clinical pathology differences, or microscopic changes observed that were considered to be related to the administration of THC. Due to the minimal THC-related effects observed in the 13-week study, doses selected for the 2-year mouse study were 125, 250, and 500 mg/kg. 13-WEEK WITH 9-WEEK RECOVERY STUDY IN RATS: Groups of 10 male and 10 female rats received 0, 5, 15, 50, 150, or 500 mg THC/kg body weight in corn oil by gavage, 5 days per week for 13 weeks, and then were allowed to recover during a 9-week treatment-free period. Five male and eight female 500 mg/kg rats, five male and two female 150 mg/kg rats, and three male and two female 50 mg/kg rats died before the end of the study. During the 13-week dosing period, mean body weight gains of all dosed groups of rats were lower than those of the controls but returned to normal during the recovery period. Final mean body weights of all dosed groups were similar to those of the controls. Clinical findings observed during the recovery period included sensitivity to touch, convulsions, and aggressiveness. The absolute right testis weight of 500 mg/kg males was significantly lower than that of the controls. Treatment-related multifocal atrophy of the testis was observed in 150 and 500 mg/kg males. There were no treatment-related lesions observed in females administered THC. 13-WEEK WITH 9-WEEK RECOVERY STUDY IN MICE: Groups of 10 male and 10 female mice received 0, 5, 15, 50, 150, or 500 mg THC/kg body weight in corn oil by gavage, 5 days per week for 13 weeks, and then were allowed to recover during a 9-week treatment-free period. The final mean body weights of all dosed groups were similar to those of the controls. Clinical findings observed during the study included lethargy and aggressiveness, and both male and female mice in all dosed groups were easily startled. The absolutebsolute and relative uterus weights of 150 and 500 mg/kg female mice were significantly lower than those of the controls, as was the absolute uterus weight of 50 mg/kg females. 2-YEAR STUDY IN RATS: Groups of 62 vehicle control male rats, 60 low-dose male rats, 70 mid- and high-dose male rats, and 60 female rats were administered 0, 12.5, 25, or 50 mg THC/kg body weight in corn oil by gavage for 104 to 105 weeks. Nine or ten animals from each group were evaluated at 15 months. Survival, Body Weights, and Clinical Findings: Survival of all dosed groups was generally significantly greater than that of the controls. Mean body weights of dosed groups of males and females were lower than those of the controls throughout the study. Convulsions and seizures were observed in all dosed groups of male and female rats, usually following dosing or handling. Hematology and Clinical Chemistry: At the 15-month interim evaluation, total leukocyte and lymphocyte counts in all dosed groups of females were greater than those of the controls, and platelet counts in these groups were lower than that of the controls. Levels of follicle stimulating and luteinizing hormones in all dosed groups of males were significantly greater than those of the controls, as was the serum corticosterone level of 25 mg/kg females. Pathology Findings: No increased incidences of neoplasms were considered related to administration of THC. The incidences of mammary gland fibroadenoma and uterine stromal polyps were decreased in dosed groups of females, as were the incidences of pituitary gland adenomas, interstitial cell adenomas of the testis, and pancreatic adenomas in dosed males. 2-YEAR STUDY IN MICE: Groups of 62 vehicle control male mice, 60 low-dose male mice, 61 mid-dose male mice, and 60 high-dose male mice and 60 female mice were administered 0, 125, 250, or 500 mg THC/kg body weight in corn oil by gavage for 104 to 105 weeks (males) or 105 to 106 weeks (females). Survival, Body Weights, and Clinical Findings: Survival of 500 mg/kg males was significantly less than that of the controls; survival of all other groups of males and of all dosed groups of females was similar to that of the controls. Mean body weights of all dosed groups were markedly lower than those of the controls throughout the study. Clinical findings in dosed groups included hyperactivity, convulsions, and seizures which occurred following dosing or handling. Hematology: At the 15-month interim evaluation, total leukocyte and lymphocyte counts in all dosed groups of males were significantly lower than those of the controls. Pathology Findings: Increased incidences of thyroid gland follicular cell adenoma occurred in 125 mg/kg males and females, but the increase was not dose-related. Increased incidences of thyroid gland follicular cell hyperplasia occurred in all dosed groups of males and females. Increased incidences of forestomach hyperplasia and ulcers occurred in all groups of males administered THC. Incidences of hepatocellular adenoma and of hepatocellular adenoma or carcinoma (combined) occurred with a significant negative trend in male and female mice, as did incidences of eosinophilic foci and fatty change in the liver. GENETIC TOXICOLOGY: THC was not mutagenic in Salmonella typhimurium strains TA97, TA98, TA100, or TA1535 with or without rat and hamster liver S9 fractions. In cultured Chinese hamster ovary cells, THC induced sister chromatid exchanges at the highest dose tested in the presence of S9; at this dose level, cell cycle delay indicative of toxicity was observed. THC did not induce chromosomal aberrations in cultured Chinese hamster ovary cells with or without S9 metabolic activation enzymes. In vivo, no increase in the frequency of micronucleated erythrocytes was observed in the peripheral blood of male or female mice administered THC by gavage for 13 weeks. CONCLUSIONS: Under the conditions of these 2-year gavage studies, there was no evidence of carcinogenic activity of 1-trans-delta(9)-tetrahydrocannabinol in male or female F344/N rats administered 12.5, 25, or 50 mg/kg. There was equivocal evidence of carcinogenic activity of THC in male and female B6C3F1 mice based on the increased incidences of thyroid gland follicular cell adenomas in 125 mg/kg groups. Increased incidences of thyroid gland follicular cell hyperplasia occurred in male and female mice, and increased incidences of hyperplasia and ulcers of the forestomach were observed in male mice. The incidences of mammary gland fibroadenomas and uterine stromal polyps were decreased in dosed groups of female rats, as were the incidences of pancreatic adenomas, pituitary gland adenomas, and interstitial cell adenomas of the testis in dosed male rats and liver neoplasms in dosed mice. These decreases were likely related to lower body weights in dosed animals. Synonyms: 3-Pentyl-6,6,9-trimethyl-6a,7,8,10a-tetrahydro-6h-dibenzo(b,d)pyran-1-ol; delta1-tetrahydrocannabinol; (-)-delta1-3,4-trans- tetrahydrocannabinol; delta(9)-tetrahydrocannabinon; THC; delta1-THC; delta(9)-THC
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PMID:NTP Toxicology and Carcinogenesis Studies of 1-Trans-Delta(9)-Tetrahydrocannabinol (CAS No. 1972-08-3) in F344 Rats and B6C3F1 Mice (Gavage Studies). 1259 29

Oxazepam is one of a number of benzodiazepines used therapeutically as a sedative-hypnotic and antianxiety agent. Toxicology and carcinogenesis studies were performed by administering oxazepam (greater than 99% pure) in feed to male and female Swiss-Webster and B6C3F1 mice for 14 weeks, 57 weeks (Swiss-Webster), or 2 years (B6C3F1). Neurobehavioral assessments were performed during the studies. Genetic toxicology studies were conducted in Salmonella typhimurium and cultured Chinese hamster ovary cells, and peripheral blood samples were analyzed for frequency of micronucleated normochromatic erythrocytes. Supplemental studies were performed to compare the metabolism and toxicokinetics of oxazepam in the two mouse strains, to evaluate the effect on liver cell replication rates, to perform clinical pathology assessments, and to examine the mutation spectrum and frequency of activated H-ras oncogenes in liver neoplasms from the 2-year study with B6C3F1 mice. 14-WEEK STUDY IN SWISS-WEBSTER MICE: Groups of 10 male and 10 female Swiss-Webster mice received oxazepam in feed at concentrations of 0, 625, 1,250, 5,000, 10,000 ppm for 14 weeks. One 625 ppm male and one 10,000 female were killed moribund before the end of the study, and the condition of the female mouse was attributed to oxazepam exposure. Mean body weight gains of exposed groups were similar to those of the controls. Exposed mice displayed chemical-related sedation and lethargy during the first study week, but appeared normal thereafter. In the neurobehavioral studies, reductions in grip strength were evident in both male and female mice at week 2 and persisted in males through week 11. An antianxiety effect was detected in exposed mice in measures of motor activity, startle response, and reactions to thermal stimulus. At necropsy, absolute and relative liver weights were increased in an exposure-related manner and were approximately two-fold greater in 10,000 ppm mice than in controls. Centrilobular hepatocellular hypertrophy was present only in exposed mice, and the severity increased with dose. 14-WEEK STUDY IN B6C3F1 MICE: Groups of 10 male and 10 female B6C3F1 mice received oxazepam in feed at concentrations of 0, Groups of 10 male and 10 female Swiss-Webster mice 625, 1,250, 2,500, 5,000, or 10,000 ppm for 14 weeks. received oxazepam in feed at concentrations of 0, There were no deaths that were clearly related to 625,1,250, 2,500, 5,000, or 10,000 ppm for 14 weeks. oxazepam exposure. Mean body weight gains of One 625 ppm male and one 10,000 ppm female were exposed groups were similar to those of the controls. Exposed mice displayed chemical-related sedation and lethargy during only the first study week. In neurobehavioral studies, reductions in grip strength were evident in males at week 2 but were no longer observed at week 12. An antianxiety effect was noted in exposed mice in measures of motor activity, startle response, and reactions to a thermal stimulus (females). At necropsy, absolute and relative liver weights were increased in an exposure-related manner and were approximately two-fold greater in 10,000 ppm mice than in controls. Centrilobular hepatocellular hypertrophy was present only in exposed mice, and the severity increased with dose. CHRONIC STUDIES: Groups of 60 male and 60 female Swiss-Webster and B6C3F1 mice received oxazepam in feed at concentrations of 0, 2,500, or 5,000 ppm. Additional groups of 60 male and 60 female B6C3F1 mice received 125 ppm in feed to allow for study of a group with projected serum concentrations of oxazepam similar to those achieved in humans taking a therapeutic dose. Ten male and 10 female B6C3F1 mice per group were evaluated at 15 months. Average daily oxazepam consumption varied throughout the studies, and the overall daily average ranged from 10 to 29 mg/kg body weight for the 125 ppm groups, 234 to 512 mg/kg for the 2,500 ppm groups, and 444 to 1,085 mg/kg for the 5,000 ppm groups. Serum oxazepam concentrations determined at 57 weeks in Swiss-Webster mice and at the 15-month interim evaluation of B6C3F1 mice 1 mice were approximately 1 ug/mL in the 125 ppm groups, 4 to 7 μg/mL in the 2,500 ppm groups, and 7 to 10 μg/mL in the 5,000 ppm groups. Neurobehavioral assessments during the chronic studies of each strain of mice were confounded by the poor survival and deteriorating condition of mice with hepatic neoplasia. However, within the limitations of the studies, there were no notable changes in the types of behaviors observed compared to those observed in the 14-week studies, nor was there an enhancement in the degree to which they were exhibited. 57-Week Study in Swiss-Webster Mice: Survival, Body Weights, Feed and Compound Consumption, and Clinical Findings: At 57 weeks, survival of exposed mice was significantly lower than that of controls (males: O ppm, 45/60; 2,500 ppm, 19/60; 5,000 ppm, 10/60; females: 47/60, 28/59, 17/59), causing the study to be terminated. Mean body weights of exposed males were similar to controls until week 17; afterwards, mean body weights of exposed male groups were lower than those of controls. Final mean body weights of exposed males were 9% lower than that of the controls. The mean body weight of 2,500 ppm females was greater than that of the controls throughout the study. Females receiving 5,000 ppm had a mean body weight greater than that of the controls early in the study; after week 29, the mean body weight of this group was similar to that of the controls. Feed consumption by exposed males and females was slightly lower than that by the controls, and females in all groups, including controls, consumed slightly more feed than males throughout the study. Dietary levels of 2,500 and 5,000 ppm oxazepam resulted in average daily compound consumption levels of 270 and 570 mg/kg for males and 320 and 670 mg/kg for females. Hypoactivity and sedation were observed in exposed mice during the first week of the study. There were no other clinical findings associated with oxazepam exposure. Pathology Findings: Systemic amyloidosis was the principal cause of death in mice dying before the study was terminated. The lower survival of mice receiving oxazepam was attributed to an increase in the extent and severity of amyloid deposits in many organs, including the heart and kidney. Atrial thrombosis and pulmonary lesions consistent with chronic heart failure occurred at higher incidences and with greater severity in exposed mice. The incidence of hepatocellular adenomas (males: 1/60, 35/60, 50/60; females: 0/60, 22/59, 47/59) and carcinomas (males: 0/60, 5/60,19/60; females: 1/60, 1/59, 11/59) were increased in exposed mice. The incidences of eosinophilic foci were also increased in exposed mice (males: 0/60, 22/60, 22/60; females: 0/60, 20/59, 14/59), and there was evidence of increased centrilobular hepatocyte hypertrophy (males: 12/60, 46/60, 47/60; females: 3/60, 51/59, 53/59). 2-Year Study in B6C3F1 Mice: Survival, Body Weights, Feed and Compound Consumption, and Clinical Findings: Survival of mice receiving 2,500 and 5,000 ppm was significantly lower than that of controls (males: O ppm, 45/50; 125 ppm, 44/50; 2,500 ppm, 15/50; 5,000 ppm, 0/50; females: 39/50, 41/50, 2/50, 0/50). Mean body weight gains of exposed male and female mice were similar to controls until about week 15 when weight gains for mice exposed to 2,500 or 5,000 ppm slowed in relation to controls, resulting in weight gains approximately 30% to 40% lower than those of the controls throughout the remainder of the study. Mean body weight gain of male mice exposed to 125 ppm was similar to that of the controls, while that of female mice receiving 125 ppm was 10% to 15% lower than that of the controls after about week 45. Feed consumption by exposed males and females was similar to that by controls. Dietary levels of 125, 2,500, and 5,000 ppm resulted in average daily oxazepam consumption levels of 12, 310, and 690 mg/kg body weight for males and 15, 350, and 780 mg/kg for females. In the 5,000 ppm groups, lethargy and sedation were observed in a few mice during the first week of study. Pathology Findings: The early deaths of many of the B6C3F1 mice exposed to oxazepam were attributed to a marked increase in the incidences of hepatoblastoma (males: 0/49, 2/50, 21/50, 13/50; females: 0/50, 1/50, 8/50, 8/50), hepatocellular adenoma (males: 17/49,18/50, 34/50, 32/50; females: 25/50, 35/50, 35/50, 36/50), and hepatocellular carcinoma (males: 9/49, 5/50, 45/50, 50/50; females: 9/50, 5/50, 49/50, 44/50). Moderate hypertrophy of centrilobular hepatocytes occurred in mice receiving 2,500 and 5,000 ppm (males: 0/49, 2/50, 26/50, 43/50; females: 0/50, 2/50,11/50, 29/50). An increase in the incidence of follicular cell hyperplasia of the thyroid gland occurred in all exposed groups of mice (males: 4/49, 22/50, 49/50, 47/50; females: 16/50, 34/50, 49/50, 44/50), and thyroid gland follicular cell adenoma was increased in exposed females (0/50, 4/50, 5/50, 6/50). Testicular atrophy occurred in the 2,500 and 5,000 ppm groups (1/50, 0/50, 25/50, 38/50), and the incidence of epididymal Iymphocyte infiltration was increased in all exposed groups (2/50,14/50, 33/50, 21/50). The frequency of hepatocellular neoplasms with an activated H-ras oncogene in the B6C3F1 mice and the mutation spectrum of the H-ras gene were determined. The mutation spectrum of the H-ras genes in the relatively few neoplasms from exposed mice that did have an activated H-ras did not differ from the spectrum of mutations observed in neoplasms from controls, but the proportion of neoplasms with an activated H-ras gene decreased with increasing oxazepam dose. While 11 of 19 (58%) neoplasms from control mice had an activated H-ras gene, only 1 of 40 neoplasms from mice receiving 2,500 or 5,000 ppm oxazepam exhibited a similar molecular lesion. Thirteen of 37 (35%) neoplasms from mice in the 125 ppm group had an activated H-ras oncogene, suggesting that, although the incidence of all liver neoplasms was not statistically increased compared to controls, there was an increase in a similar subset of neoplasms (lacking an activated H-ras) that occurred with increased incidence at higher doses. SUPPLEMENTAL STUDIES: Because exposure to oxazepam caused increased incidences of liver neoplasms, supplemental short-term studies were performed. Oxazepam given in feed to male B6C3F1 mice at 25, 125, 2,500, or 5,000 ppm for up to 13 weeks was found to cause a dose-related increase in nuclear labeling index in studies measuring the incorporation of bromodeoxyuridine into replicating liver cells. This increase was statistically significant at all but the 25 ppm exposure level and was limited to mice evaluated at 15 days. Cell replication rates in most groups evaluated at 30 days and after were similar to control rates. There was minimal evidence suggestive of hepatocyte necrosis either by light microscopy or in clinical chemistry measures. There was, however, evidence of cholestasis, likely due to physical obstruction of bile canaliculi by swollen hepatocytes. The metabolic fate and toxicokinetics of oxazepam were evaluated in each strain of mice and were compared to published data from human studies. Both mice and humans form glucuronides of oxazepam and form 3- and 4-hydroxy and methoxy derivatives of the phenyl group. Oxidative metabolism of the phenyl group appears to be more prevalent in mice than is reported for humans. Elimination half-lives of parent compound do not differ between Swiss-Webster and B6C3F1 mice and are similar to values reported for humans. GENETIC TOXICOLOGY: Oxazepam was not mutagenic in any of several strains of Salmonella typhimurium, nor did it induce sister chromatid exchanges or chromosomal aberrations in cultured Chinese hamster ovary cells. These in vitro tests were performed with and without S9 metabolic activation. Results from an in vivo mouse peripheral blood micronucleus test performed on the B6C3F1 mice used in the 14-week study were also negative. CONCLUSIONS: Under the conditions of these feed studies, there was clear evidence of carcinogenic activity of oxazepam in male and female Swiss-Webster mice based on increased incidences of hepatocellular adenoma and carcinoma. There was clear evidence of carcinogenic activity of oxazepam in male and female B6C3F1 mice based on increased incidences of hepatoblastoma and hepatocellular adenoma and carcinoma. Increased incidences of hyperplasia of thyroid gland follicular cells in male and female B6C3F1 mice and of follicular cell adenomas in female B6C3F1 mice were also related to oxazepam exposure. Administration of oxazepam to Swiss-Webster mice resulted in centrilobular hepatocellular hypertrophy and increased incidences and severity of systemic amyloidosis. Administration of oxazepam to B6C3F1 mice also resulted in centrilobular hepatocellular hypertrophy. Synonyms: 7-Chloro-1,3-dihydro-3-hydroxy-5-phenyl-2 H - 1,4-benzodiazepin-2-one Trade Names: Tazepam, Wy-3498, Serax
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PMID:NTP Toxicology and Carcinogenesis Studies of Oxazepam (CAS No. 604-75-1) in Swiss-Webster and B6C3F1 Mice (Feed Studies). 1259 20

p-Nitrobenzoic acid is produced in large volumes for organic synthesis and as an intermediate in the manufacture of pesticides, dyes, and industrial solvents. Groups of male and female F344/N rats and B6C3F1 mice were exposed to p-nitrobenzoic acid (>99% pure) in feed for 14 days, 13 weeks, or 2 years for toxicity and carcinogenicity studies. Genetic toxicology studies were conducted in in vitro assays with Salmonella typhimurium and cultured Chinese hamster ovary cells, and in studies of erythrocyte micronucleus formation in mice in the 13-week study. 14-DAY STUDY IN RATS: Groups of five male and five female rats were given 0, 2,500, 5,000, 10,000, 20,000, or 40,000 ppm p-nitrobenzoic acid in feed for 14 days. All rats survived until the end of the study. Male and female rats given 20,000 and 40,000 ppm lost weight. The final mean body weights of 10,000, 20,000, and 40,000 ppm males were 82%, 60%, or 52% that of the controls, and the final mean body weights of 10,000, 20,000, and 40,000 ppm females were 87%, 68%, and 65% that of the controls. There were no clinical findings that were characteristic of organ-specific toxicity. Absolute and relative spleen weights were significantly increased in rats exposed to 10,000, 20,000, and 40,000 ppm. There were decreases in erythrocyte count and hemoglobin and hematocrit values and increases in reticulocyte count, nucleated erythrocytes, and methemoglobin concentration that were most pronounced in the 20,000 and 40,000 ppm groups. Congestion of the spleen occurred in 10,000 ppm males and in 20,000 and 40,000 ppm females. Hypertrophy of the follicular epithelium of the thyroid gland was present in male and female rats exposed to 10,000, 20,000, or 40,000 ppm p-nitrobenzoic acid, while follicular hyperplasia was observed in the 40,000 ppm males and females. Atrophy of the testis was observed in 20,000 and 40,000 ppm males. Other lesions observed in 20,000 and 40,000 ppm rats included atrophy of the thymus in males and atrophy of the ovary, bone marrow, and thymus in females. 14-DAY STUDY IN MICE: Groups of five male and five female mice were given 0, 2,500, 5,000, 10,000, 20,000, or 40,000 ppm p-nitrobenzoic acid in feed for 14 days. Three males and two females given 40,000 ppm died during the study. All other animals survived until the end of the study. Male mice given 20,000 and 40,000 ppm and females given 20,000 ppm lost weight. Mean body weight gains of 20,000 and 40,000 ppm males and 10,000, 20,000, and 40,000 ppm females were significantly lower than those of the controls. There were no clinical findings related to organ-specific toxicity although lethargy and ataxia were observed in 40,000 ppm mice. Relative liver weights were significantly increased in 20,000 and 40,000 ppm males and females and in 10,000 ppm females. Absolute and relative thymus weights of 20,000 and 40,000 ppm males and of 10,000, 20,000, and 40,000 ppm females were reduced. No significant differences in hematology parameters occurred in exposed mice. Testicular degeneration was observed in three 20,000 ppm and two 40,000 ppm males. Bone marrow hemorrhage and atrophy occurred in 40,000 ppm females. 13-WEEK STUDY IN RATS: Groups of 10 male and 10 female rats were given 0, 630, 1,250, 2,500, 5,000, or 10,000 ppm pnitrobenzoic acid in feed for 13 weeks resulting in approximate daily doses of 40, 70, 160, 310, or 660 mg/kg to males and 40, 80, 170, 340, or 680 mg/kg to females. All rats survived until the end of the study. Mean body weight gains and final mean body weights were significantly less than those of the controls in 2,500, 5,000, and 10,000 ppm males and in 5,000 and 10,000 ppm females. There were no clinical findings related to organ-specific toxicity. Differences in spleen weights and hematology parameters characteristic of regenerative anemia were observed in males and females, primarily in groups given 10,000 ppm. The absolute and relative spleen weights were significantly increased in 10,000 ppm males and females and the relative spleen weights were significantly increased in 5,000 ppm males hts were significantly increased in 5,000 ppm males and females. Methemoglobin, Heinz bodies, and reticulocyte counts were increased and erythrocyte counts, hemoglobin, and hematocrit values were decreased in 10,000 ppm males and females. Congestion, pigmentation, and accumulation of macrophages in the spleen and pigmentation in the kidney occurred in 2,500, 5,000, and 10,000 ppm males. Congestion and pigmentation of the spleen occurred in 10,000 ppm females. A yellowish brown pigment (hemosiderin) in the spleen and kidney was associated with hemolytic anemia. Mild cytoplasmic hyaline droplet accumulation was present in renal tubule epithelial cells in 10,000 ppm males while karyomegaly was present in male and female rats exposed to 2,500, 5,000, and 10,000 ppm p-nitrobenzoic acid. A chemical-related testicular lesion, consisting of atrophy of the seminiferous tubules, occurred in 10,000 ppm males. 13-WEEK STUDY IN MICE: Groups of 10 male and 10 female mice were given 0, 1,250, 5,000, 10,000, or 20,000 ppm pnitrobenzoic acid in feed for 13 weeks resulting in approximate daily doses of 170, 330, 670, 1,900, or 4,000 mg/kg body weight to males and 240, 460, 970, 2,500, or 4,900 mg/kg to females. All mice survived until the end of the study, except one 1,250 ppm female that was killed accidentally. Final mean body weights and mean body weight gains of all exposed males and of 5,000, 10,000, and 20,000 ppm females were significantly lower than those of the controls. No clinical findings or differences in organ weights or histopathology related to organ-specific toxicity were observed in exposed mice. 2-YEAR STUDY IN RATS: Groups of 60 male and 60 female rats were given 0, 1,250, 2,500, or 5,000 ppm p-nitrobenzoic acid in feed for 2 years. Ten males and 10 females from each exposure group were evaluated at 15 months. Survival, Body Weights, Feed Consumption, and Clinical Findings: Two-year survival rates of 1,250 and 2,500 ppm males were similar to that of the controls. Two-year survival of 5,000 ppm males was marginally greater than that of the controls and was attributed in part to a decrease in the severity of nephropathy and a decrease in the incidence of mononuclear cell leukemia. Survival of exposed females was similar to that of the controls. Mean body weights of 5,000 ppm males were 2% to 8% lower than those of the controls through week 80. Final mean body weights of exposed males were similar to that of the controls. Mean body weights of 5,000 ppm females were 2% to 9% lower than those of the controls during the first year of the study and were 10% to 16% lower during the second year of the study. Final mean body weights of exposed females were 97% (1,250 ppm), 92% (2;500 ppm), and 84% (5,000 ppm) that of the controls. Feed consumption by exposed males and females was similar to that by the controls. Dietary levels of 1,250, 2,500, or 5,000 ppm p-nitrobenzoic acid delivered approximately 50, 100, or 210 mg/kg body weight per day to males and 60, 125, or 250 mg/kg per day to females. There were no clinical findings attributable to organ-specific toxicity. Pathology Findings: There were increases in the incidences of clitoral gland adenoma and of clitoral gland adenoma or carcinoma (combined) (4/50, 14/49, 15/49, 15/50) in exposed females. The incidences of clitoral gland adenoma or carcinoma (combined) in the exposed groups (29% to 31%) exceeded the historical control mean incidence (11%) and range (2% to 21%) in female F344/N rats in recent 2-year NTP feed studies. The increased incidences of clitoral gland neoplasms were considered to be some evidence of carcinogenic activity in female rats exposed to p-nitrobenzoic acid. The incidences of hyperplasia of the clitoral gland in exposed females were marginally lower than that of the controls (10/50, 6/49, 6/ 49, 7/50). There was a chemical-related decrease in the severity of nephropathy in male rats. Male rat kidneys were examined using both single and step-section analyses, and the incidences of renal tubule neoplasms were not statistically greater than those of the controls. Mild hyaline droplet accumulation was observed in renal tubule epithelial cells in 10,000 ppm males in the 13-week study, but this effect was not severe enough to lead to a chemical-related neoplastic response in the 2-year study as has been observed with other chemicals. At the 15-month interim evaluation, hematologic parameters characteristic of a mild regenerative anemia and significant differences in spleen weights were noted in 5,000 ppm females. These differences included decreases in erythrocyte count, hemoglobin, and hematocrit, increases in spleen weights, and hemosiderin accumulation in splenic macrophages. At 2 years, significant decreases in the incidences of mononuclear cell leukemia were observed in 5,000 ppm males and 2,500 and 5,000 ppm females (males: 29/50, 35/50, 26/50, 2/50; females: 17/50, 11/50, 3/50, 0/50). While the mechanism for this decrease is unknown, decreases in the incidence of mononuclear cell leukemia have also been observed in 2year studies with other amine/nitro compounds. 2-YEAR STUDY IN MICE: Groups of 60 male and 60 female mice were given 0, 1,250, 2,500, or 5,000 ppm p-nitrobenzoic acid in feed for 2 years. Ten males and 10 females from each exposure group were evaluated at 15 months. Survival, Body Weights, Feed Consumption, and Clinical Findings: Two-year survival rates of exposed mice were similar to those of the controls. Mean body weights of 5,000 ppm males were 6% to 12% lower than those of the controls after week 17, and mean body weights of 5,000 ppm females were 12% to 24% lower than those of the controls after week 16. The final mean body weight of 5,000 ppm females was 19% less than that of the controls; final mean body weights of males were similar to that of the controls. Feed consumption by exposed mice was similar to that by the controls. Dietary levels of 1,250, 2,500, or 5,000 ppm p-nitrobenzoic acid delivered approximately 150, 300, or 675 mg/kg per day to males and 170, 365, or 905 mg/kg per day to females. There were no clinical findings of organ-specific toxicity. No chemical-related effects on hematology parameters were noted at the 15-month interim evaluation. Pathology Findings: There were no increases or decreases in neoplasms in male or female mice that were considered to be related to chemical administration. GENETIC TOXICOLOGY: p-Nitrobenzoic acid was mutagenic in Salmonella typhimurium strain TA100 with and without S9. No mutagenic activity was noted in strains TA98, TA1535, or TA1537, with or without S9. p-Nitrobenzoic acid induced sister chromatid exchanges and chromosomal aberrations in cultured Chinese hamster ovary cells in the absence of S9; with S9, results of both tests were negative. In vivo, no increase in micronuclei was observed in peripheral blood erythrocytes of male or female mice administered p-nitrobenzoic acid in dosed feed for 13 weeks. CONCLUSIONS: Under the conditions of these 2-year feed studies, there was no evidence of carcinogenic activity of p-nitrobenzoic acid in male F344/N rats exposed to 1,250, 2,500, or 5,000 ppm. There was some evidence of carcinogenic activity of p-nitrobenzoic acid in female F344/N rats based on increases in the incidences of clitoral gland adenoma and of clitoral gland adenoma or carcinoma (combined). There was no evidence of carcinogenic activity of p-nitrobenzoic acid in male or female B6C3F1 mice exposed to 1,250, 2,500, or 5,000 ppm. There were chemical-related decreases in the incidences of mononuclear cell leukemia in exposed male and female rats. p-Nitrobenzoic acid caused mild hematologic toxicity in female rats. Synonyms: 4-Nitrobenzoic acid; nitrodracylic acid; p-nitrobenzenecarboxylic acid; p-carboxynitrobenzene
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PMID:NTP Toxicology and Carcinogenesis Studies of p-Nitrobenzoic Acid (CAS No. 62-23-7) in F344/N Rats and B6C3F1 Mice (Feed Studies). 1259 21

Nitrofurazone is a synthetic furan derivative, active against a broad spectrum of bacteria, which has been widely used in veterinary and human medicine. Toxicology and carcinogenesis studies were conducted by feeding diets containing nitrofurazone (99% pure) to groups of F344/N rats and B6C3F1 mice of each sex for 14 days, 13 weeks, or 2 years. Fourteen-Day and Thirteen-Week Studies: Groups of five males and five females of each species were fed diets containing 0, 630, 1,250, 2,500, 5,000, or 10,000 ppm for 14 consecutive days. Early deaths occurred in all groups of rats receiving 5,000 or 10,000 ppm nitrofurazone. The surviving rats in the lower two dose groups gained weight, but weight gain was decreased as the dose of nitrofurazone was increased. Feed consumption by rats of each sex was decreased at all doses above 630 ppm. In all dosed groups, clinical signs of toxicity included rough hair coats and lethargy. At doses of 2,500 ppm and above, rats of each sex exhibited intermittent episodes of seizures and lethargy. All mice that received 2,500, 5,000, or 10,000 ppm nitrofurazone and 3/5 males that received 1,250 ppm died before the end of the 14-day studies; the surviving dosed mice (except females at 630 ppm) lost weight. A dose-related decrease in feed consumption was observed at all doses above 630 ppm. Clinical signs included rough hair coats and convulsive seizures. In the 13-week studies, groups of 10 rats of each sex were given diets containing 0, 150, 310, 620, 1,250, or 2,500 ppm nitrofurazone. No deaths were observed and all animals gained weight, but the magnitude of weight gain was dose dependent with decrements in final mean body weight for the highest dose group reaching 55% in males and 36% in females. Other evidence of chemically related toxicity included convulsive seizures, osteoporosis, degenerative arthropathy, and gonadal hypoplasia in both sexes at the two highest doses. Groups of 10 mice of each sex were given diets containing 0, 70, 150, 310, 620, or 1,250 ppm nitrofurazone for 13 weeks. Early deaths were observed in the two highest dose groups of each sex. The final mean body weights of male and female mice in the 1,250-ppm groups were about 20% lower than those of the controls; weight gains of the other dosed mice were comparable to those of the controls. Stimulus-induced convulsive seizures were observed for all mice in the two highest dose groups. Testicular hypoplasia was observed in the two highest dose groups of male mice. Body Weight and Survival in the Two-Year Studies: Dietary concentrations for the 2-year studies were 0, 310, or 620 ppm for rats and 0, 150, or 310 ppm for mice (50 animals per dose group). Mean body weights of high dose male rats were lower than those of the controls after week 39; mean body weights of low dose male rats and of the controls were comparable throughout the study. Final mean body weights of low and high dose female rats were 9% and 21% lower than those of the controls. Dosed rats consumed less feed than did the controls. The average amount of nitrofurazone consumed per day was approximately 11-12 or 24-26 mg/kg by low or high dose male and female rats. The survival of the high dose group of male rats was lower than that of the controls after week 92 (final survival-- male: control, 33/50; low dose, 30/50; high dose, 20/50; female: 28/50; 37/50; 31/50). Mean body weights of dosed mice were similar to or somewhat greater than those of controls throughout most of the studies. The average daily feed consumption by dosed mice was similar to that of controls. The average amount of nitrofurazone consumed per day was approximately 14-16 or 29-33 mg/kg for low or high dose male and female mice. The survival of the high dose group of male mice was lower than that of the controls after week 88 (final survival-- male: 39/50; 31/50; 27/50; female: 39/50; 40/50; 35/50). In mice of each sex, nitrofurazone administration induced stimulus-sensitive convulsive seizures beginning at week 4 or 5 for high dose mice and week 24 for low dose female mice. These seizures were low dose female mice. These seizures were observed primarily in the first year of the study. Nonneoplastic and Neoplastic Effects in the Two-Year Studies: Degenerative changes involving the vertebral and femoro-tibial (knee) joints were observed at increased incidences in dosed rats. The degenerative changes primarily affected the articular cartilage and were similar to those seen in the 13-week studies. Degeneration of the sternal synchondroses was increased in high dose female rats. The osteoporosis seen in the 13-week studies was not observed in the 2-year studies. Testicular degeneration, characterized by atrophy of the germinal epithelium and aspermatogenesis, was observed at increased incidences in dosed male rats (control, 12/50; low dose, 49/50; high dose, 47/50). Adenomas of the sebaceous glands and trichoepitheliomas or sebaceous adenomas (combined) of the skin were observed in high dose male rats (0/50; 0/50; 5/50). Carcinomas of the preputial gland were increased in dosed male rats (1/50; 8/50; 5/50). The incidences of preputial gland adenomas or carcinomas (combined) in dosed male rats were not statistically greater than that in the controls (9/50; 16/50; 7/50). However, in the low dose group, the incidence is greater than the highest incidence observed in historical untreated control groups (9/50). In addition, hyperplasia of the preputial gland was observed in six low dose male rats in which neither adenomas nor carcinomas occurred. The incidence of mesotheliomas of the tunica vaginalis in low dose male rats was greater than that in the controls (0/50; 7/50; 2/50). Fibroadenomas of the mammary gland occurred at markedly increased incidences in dosed female rats (8/49; 36/50; 36/50). Three adenocarcinomas were also observed (1/49; 0/50; 2/50). Ovarian atrophy (7/47; 44/50; 38/50) and tubular cell hyperplasia of the ovary (1/47; 23/50; 21/50) were observed at markedly increased incidences in dosed female mice. The incidences of benign mixed tumors (0/47; 17/50; 20/50), granulosa cell tumors (1/47; 4/50; 9/50), and granulosa cell tumors or luteomas (combined) (3/47; 6/50; 9/50) of the ovary were increased in exposed female mice. Mononuclear cell leukemia in rats occurred with negative trends (male: 21/50; 23/50; 6/50; female: 15/49; 2/50; 2/50). In female mice, the incidences of adenomas or carcinomas (combined) of the anterior pituitary gland occurred with a negative trend (10/50; 7/50; 2/49). The incidences of testicular interstitial cell tumors were decreased in dosed male rats (45/50; 30/50; 28/50). Genetic Toxicity: Nitrofurazone was mutagenic in Salmonella typhimurium strains TA98 and TA100 both with and without exogenous metabolic activation. The responses in strains TA1535 and TA1537 were more varied: nitrofurazone was mutagenic in strain TA1535 only in the presence of S9 and produced no consistent increase in gene reversions in strain TA1537 with or without S9. In the absence of metabolic activation, nitrofurazone induced forward mutations at the TK+/- locus of mouse L5178Y lymphoma cells; the chemical was not tested with S9. Treatment of cultured Chinese hamster ovary cells with nitrofurazone in the absence of S9 produced a dose-related increase in sister chromatid exchanges and chromosomal aberrations; with S9, sister chromatid exchanges were increased, but no induction of chromosomal aberrations was observed. Audit: The data, documents, and pathology materials from the 2-year studies of nitrofurazone were audited at the NTP Archives. 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 equivocal evidence of carcinogenic activity of nitrofurazone for male F344/N rats as shown by the occurrence of sebaceous gland adenomas and trichoepitheliomas of the skin, mesotheliomas of the tunica vaginalis, and preputial gland tumors. There was clear evidence of carcinogenic activity of nitrofurazone for female F344/N rats as shown by a markedly increased incidence of fibroadenomas of the mammary gland. There was no evidence of carcinogenic activity for male B6C3F1 mice fed diets containing nitrofurazone at concentrations of 150 or 310 ppm. There was clear evidence of carcinogenic activity of nitrofurazone for female B6C3F1 mice as shown by increased incidences of benign mixed tumors and granulosa cell tumors of the ovary. Administration of nitrofurazone was associated with decreased incidences of mononuclear cell leukemia in male and female rats, testicular interstitial cell tumors in male rats, and pituitary gland neoplasms in female mice. Convulsive seizures in mice of each sex, ovarian atrophy in female mice, testicular degeneration in rats, and degeneration of articular cartilage in rats were all associated with the administration of nitrofurazone. Synonyms: 5-nitro-2-furaldehyde semicarbazone; 2-[(5-nitro-2-furanyl)methylene]hydrazine carboximide Trade Names: Aldomycin; Amifur; Chemfuran; Coxistat; Furacin; Furacinetten; Furaplast; Furazol W; Furesol; Furracoccid; Mammex; Nefco; Nifuzon; Nitrofural; Vabrocid
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PMID:NTP Toxicology and Carcinogenesis Studies of Nitrofurazone (CAS No. 59-87-0) in F344/N Rats and B6C3F1 Mice (Feed Studies). 1273 99

Although recent trials have raised concerns about the toxicity of raltitrexed monotherapy in patients with advanced colorectal cancer (aCRC), similar concerns have also been raised with other chemotherapy regimens in aCRC. The lessons learnt form our previous experiences with raltitrexed are, therefore, still important as they offer practical guidances to optimise tolerability of chemotherapy for CRC in general. The aims of the study were to report the low-toxicity profile in 58 patients receiving raltitrexed when a rigorous patient information and education strategy was implemented together with an intensive supportive adjuvant drugs regimen from the start. After a discussion with the consultant, all patients received a further consultation with a specialist nurse, a series of bespoke information tools, including an information video and written guidelines on how to avoid, prevent and deal promptly with the side-effects of raltitrexed. They all received intravenous adjuvant ondansetron and dexamethasone, then oral domperidone, ranitidine and nystatin from cycle one. The dose intensity was 98% over 307 cycles. Toxicity associated with raltitrexed comprised grade 1/2 diarrhoea (31.6% of treatment cycles), nausea (12.4%) and vomiting (8.4%), with no grade 3/4 events; grade 1/2 alopecia (17.9%); grade 1 (only) stomatitis (2.3%) and grade 1/2/3 lethargy (70.3%, only 2.3% grade 3), anaemia (14.3%, only 0.3% grade 3) and neutropenia (3.3%, only 0.3% grade 3). There were no treatment-related deaths. The low toxicity, despite high-dose intensity, suggests that intensive supportive education and drugs should have a role in the future design of regimens containing raltitrexed and other chemotherapy regimens for colorectal carcinoma.
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PMID:Lessons learned from raltitrexed--quality assurance, patient education and intensive supportive drugs to optimise tolerability. 1292 50


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