Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0001430 (adenoma)
 21,222 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Gene-Tox Carcinogen Data Base is an evaluated source of cancer data on 506 chemicals selected in part for their previous assessment in genetic toxicology bioassays. This data base has been analyzed for the distribution of these chemicals into chemical classes. The major chemical classes (6% or greater of the total data base) are: acyl-, alkyl-, and aryl-halides; alcohols and phenols; aliphatic and aromatic amines, amides, and sulfonamides; benzene-ring-containing chemicals; organo-lead, -mercury, -phosphorous compounds, metals and derivatives, phosphoric acid esters, and phosphoramides; and polycyclic aromatic hydrocarbons. Cancer studies representing a subset of the Gene-Tox Carcinogen Data Base, 199 chemicals which were rated as Sufficient Positive/Negative or Limited Positive/Negative, were examined for distribution of those studies by animal species, gender, route of chemical administration, duration of study, major tumor sites, and major tumor types. These analyses revealed that the Gene-Tox Carcinogen Data Base contains a large number of lifetime studies involving the rat and mouse treated by oral routes of administration. The major organs that were targets were: liver, lung, skin, forestomach, bladder, and mammary gland, while the major tumor types were: carcinoma, sarcoma, papilloma, and adenoma. Chemicals in the data base have been assessed for species-specific carcinogenic effects, and these results indicate that for mice and rats there is a high correspondence (85%). This number is higher than that (71%) reported by Tennant et al. (1986) based on the recent results of 72 chronic cancer bioassays performed by the National Toxicology Program. This difference is probably based on the nature of the chemicals selected for inclusion in both data bases. Although the absolute value of this correspondence is unknown, it would seem to be within this range. When chemicals in the Gene-Tox Carcinogen Data Base were examined for their previous evaluation in 73 genetic toxicology bioassays, only 26 of these bioassays had 30 or more chemicals. In these 26 bioassays, the prevalence of positive chemicals was generally greater than 80-90%. This suggests that a thorough evaluation of genetic toxicology bioassays in regard to their ability to predict carcinogenic effects in animals is premature at this time.
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PMID:An analysis of the Gene-Tox Carcinogen Data Base. 328 89

Female Swiss mice were exposed to methylmercury in the drinking water for 15 weeks. The mice were administered concentrations of methylmercury ranging from 0 to 2.0 micrograms/mL mercury. After three weeks of the 15 week exposure period, the mice were administered urethan (1.5 mg/g) intraperitoneally. Pulmonary adenoma formation was evaluated 12 weeks later. Methylmercury exposures of 0.2 and 0.5 micrograms/mL did not affect the number of adenomas, but 2.0 micrograms/mL mercury caused a significant increase in adenoma production. A dose-dependent increase in the mean tumor diameter was seen at methylmercury exposures up to 0.5 micrograms/mL. No further increase in diameter was seen at higher exposures (2.0 micrograms/mL). The changes in adenoma production were seen at exposure levels of methylmercury which did not cause any clinical manifestations. Animal weight gains and water consumption were not affected. In addition, urethan-induced sleeping times which reflect the rate of urethan metabolism or excretion remained unchanged.
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PMID:Enhancement of urethan-induced adenoma formation in Swiss mice exposed to methylmercury. 647

Aldosterone-producing adenoma (aldosteronoma)--the most frequent form of primary hyperaldosteronism (PH)--is considered a specific form of diabetes mellitus (DM). In a previous study we demonstrated insulin resistance in patients with PH. We have therefore undertaken a study to evaluate the incidence of abnormalities of glucose metabolism in patients with PH (36 subjects) compared to control subjects with essential hypertension (EH) (21 patients). The following parameters were measured in all studied subjects: office blood pressure (by mercury sphygmomanometer in the sitting position), body mass index (BMI), plasma potassium, plasma glucose and insulin levels during oral glucose tolerance test (OGTT) (0, 60, 120 min), plasma renin activity and plasma aldosterone. Although patients with PH tended to have higher stimulated plasma glucose levels after 60 and 120 min compared to EH, these differences did not attain statistical significance. Patients with EH tended to have higher insulin levels at each measured interval, but due to a high variability these differences were again not significant. There were no significant differences between PH and EH in the proportion of diabetics (20% vs. 14%) or patients with impaired glucose tolerance (18% vs. 10%). In conclusion, we have found the absence of significant differences in the frequency of diabetes mellitus, impaired glucose tolerance and insulin resistance in patients with EH and PH. Our data thus do not support the idea of primary hyperaldosteronism as a specific type of diabetes mellitus. Furthermore, our results indicate that glucose metabolic characteristics in essential hypertension and primary hyperaldosteronism tend to be similar. The definitive conclusion with respect to the possible causal relationship between DM and PH, however, can be obtained only on larger groups of subjects, in particular after the evaluation of the effect of surgical/pharmacological treatment of primary hyperaldosteronism.
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PMID:Can primary hyperaldosteronism be considered as a specific form of diabetes mellitus? 1182 22

Mercuric chloride is an inorganic compound that has been used in agriculture as a fungicide, in medicine as a topical antiseptic and disinfectant, and in chemistry as an intermediate in the production of other mercury compounds. The widespread use of mercury has resulted in increased levels of mercury in rivers and lakes. Mercuric chloride was evaluated in toxicity and carcinogenicity studies because of its extensive use and its occurrence as an environmental pollutant, and because of the lack of adequate long-term rodent studies. Toxicology and carcinogenesis studies were conducted by administering mercuric chloride (greater than 99% pure) in deionized water by gavage to groups of F344 rats or B6C3F1 mice for 16 days, 6 months, and 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium (strains TA98, TA100, TA1535, and TA1537), in mouse lymphoma L5178Y cells, in Chinese hamster ovary cells, and in Drosophila melanogaster. 16-DAY STUDIES: Groups of five rats of each sex received 0, 1.25, 2.5, 5, 10, or 20 mg mercuric chloride/kg body weight and groups of five mice of each sex received 0, 5, 10, 20, 40, or 80 mg/kg in deionized water by gavage for 12 dose days. Two male rats in the 20 mg/kg group died in the first week, as did all male and four female mice from the 80 mg/kg group and one male mouse from the 40 mg/kg group. The final mean body weight of male rats receiving 20 mg/kg was 10% lower than that of the controls; the final mean body weight of 20 mg/kg females was 9% lower than that of the controls. Final mean body weights and body weight gains of dosed mice were similar to those of the controls. Absolute and relative kidney weights of male rats receiving 2.5 mg/kg or greater doses and of female rats administered 5 mg/kg or more were significantly greater than those of the controls. Absolute kidney weights of mice were significantly increased in all male dose groups and in the 40 mg/kg female dose group; relative kidney weights of dosed male and female mice were significantly greater than the controls. Analysis of kidney, liver, and brain tissues for mercury residues revealed that the highest mercury concentration was in the kidneys of rats and mice. Acute renal tubule nephropathy occurred in dosed rats and was slightly more severe in males than in females. Chemical-related lesions in mice included renal tubule necrosis, inflammation and necrosis of the forestomach, and necrosis of the glandular stomach. 6-MONTH STUDIES: Groups of 10 rats of each sex received 0, 0.312, 0.625, 1.25, 2.5, or 5 mg mercuric chloride/kg body weight in deionized water by gavage for 26 weeks. Groups of 10 mice of each sex received 0, 1.25, 2.5, 5, 10, or 20 mg/kg in deionized water by gavage for 26 weeks (males) or 27 weeks (females). No deaths related to mercuric chloride administration occurred in rats or mice. Mean body weight gains of male rats that received 5 mg/kg and all female rat dose groups that received 0.625 mg/kg or greater were significantly lower than the controls. The final mean body weight and body weight gain of male mice in the 20 mg/kg group were significantly lower than those of the controls; final mean body weights and body weight gains of other dosed male mice and all dosed female mice were similar to those of the controls. Absolute and relative kidney weights of all dosed male rats and of female rats that received 0.625 mg/kg or greater were significantly greater than those of the controls. In male mice, absolute kidney weights in the three highest dose groups were significantly increased; no biologically significant differences in organ weights occurred in female mice. Analysis of kidney, liver, and brain tissues for mercury residues revealed the highest mercury concentration in the kidneys of rats and mice. The severity of chronic nephropathy increased with dose in male rats. Cytoplasmic vacuolation of renal tubule epithelial cells was observed in male mice in the 5, 10, and 20 mg/kg groups. No histopathologic changes in female mice were related to chemical exposure. 2-YEAR STUDIES: Groups YEAR STUDIES: Groups of 60 rats of each sex received 0, 2.5, or 5 mg mercuric chloride/kg body weight and groups of 60 mice of each sex received 0, 5, or 10 mg/kg in deionized water by gavage 5 days per week for 2 years. The doses were based on decreased weight gains in rats receiving 10 and 20 mg/kg and the decreased weight in male mice receiving 40 mg/kg during the 16-day studies, and on the decreased weight gains and toxicity results seen in the 6-month studies. Increased absolute and relative kidney weights in rats and male mice in the 6-month studies and degenerative renal changes suggested that higher dose levels would result in inadequate survival rates for a 2-year study. 15-Month Interim Evaluations: Relative kidney weights were significantly increased in dosed rats and female mice. The severity of nephropathy was increased in male rats, but not in females. High-dose male and female rats had minimal to mild hyperplasia of the basal cell layer in the forestomach epithelium (diagnosed as acanthosis); this lesion was not found in control or low-dose rats. Male mice had an increased severity of vacuolation of the renal tubule epithelium; no chemical-related lesions occurred in the kidneys of females. The incidence of inflammation of the olfactory epithelium lining the nasal cavity increased in male and female high-dose mice. Survival, Body Weights, and Clinical Signs: Survival of dosed male rats was lower than that of the controls (26/50, 10/50, 5/50); survival of dosed female rats was similar to that of the controls (35/50, 28/49, 30/50). Although more than 60% of the mice in each dose group survived to study end, survival rates of high-dose male mice and dosed female mice were lower than those of the controls (males: 36/50, 36/50, 31/50; females: 41/50, 35/50, 31/50). The final mean body weights of high-dose male and female rats were 15% and 14% lower than controls, respectively. The mean body weight of low-dose female rats was generally similar to controls throughout the 2-year study; the mean body weight of low-dose male rats was similar to that of the control through week 89. In mice, mean body weights of all male and female dose groups were similar to those of the controls throughout the studies. Pathology Findings: Chronic nephropathy appeared to develop at an accelerated rate and led to decreased survival in both dosed male rat groups. Secondary effects of renal dysfunction in dosed male rats resulted in increased incidences of fibrous osteodystrophy of the bone, mineralization of various tissues, and parathyroid gland hyperplasia. Based on evaluations of single and step sections, the incidence of renal tubule hyperplasia was increased in high-dose male rats (control, 3/50; high-dose, 10/50), but the incidences of renal tubule adenoma in high-dose and control males were similar (4/50, 5/50). Renal tubule hyperplasia was also slightly increased in high-dose female rats (2/50, 5/50) and adenomas were seen in high-dose females, but not in controls (0/50, 2/50). Incidences of forestomach hyperplasia in rats were markedly increased in dosed males (3/49, 16/50, 35/50) and high-dose females (5/50, 5/49, 20/50). Squamous cell papillomas of the forestomach were found in 3 low-dose and 12 high-dose males and in 2 high-dose females. No squamous cell carcinomas were found. The incidence of thyroid follicular cell carcinoma was marginally increased in high-dose male rats (1/50, 2/50, 6/50). However, a corresponding increased incidence in follicular cell adenomas (1/50, 4/50, 0/50) or hyperplasia (2/50, 4/50, 2/50) in males did not occur, and the overall incidence of follicular cell neoplasms was not significantly increased (2/50, 6/50, 6/50). The incidence of nasal mucosa inflammation in male and female rats was increased in the high-dose groups (male: 9/50, 8/47, 18/50; female: 0/49, 5/49, 15/50) and may have been related to chemical administration. The incidences of mammary gland fibroadenomas were significantly decreased in dosed female rats (15/50, 5/48, 2/50). The incidence and severity of nephropathy were increased in dosed mice; secondary effects of renal dysfunction did not occur. Renal tubule hyperplasia was found in one control and two high-dose male mice. Two renal tubule adenomas and one renal tubule adenocarcinoma were seen in high-dose male mice. Additional step sections revealed focal hyperplasia in another control male; no additional renal tubule neoplasms were found in high-dose or control males. Proliferative lesions of the renal tubule epithelium were not found in female mice. The incidence of metaplasia of the olfactory epithelium increased with dose in male and female mice. No other biologically significant lesions were found. GENETIC TOXICOLOGY: Mercuric chloride was not mutagenic in Salmonella typhimurium strains TA100, TA1535, TA1537, or TA98 with or without exogenous metabolic activation (S9). Induction of sex-linked recessive lethal mutations in germ cells of male Drosophila melanogaster did not occur when mercuric chloride was administered in feed or by injection. However, positive results were obtained in mutagenicity tests with mammalian cells. In the absence of S9, mercuric chloride induced trifluorothymidine resistance in mouse L5178Y cells and chromosomal aberrations in Chinese hamster ovary cells. In the Chinese hamster ovary cell test for induction of sister chromatid exchanges, mercuric chloride produced a negative response without S9 and a weakly positive response in the presence of S9. CONCLUSIONS: Under the conditions of these 2-year gavage studies, there was some evidence of carcinogenic activity of mercuric chloride in male F344 rats based on the increased incidence of squamous cell papillomas of the forestomach. Marginally increased incidences of thyroid follicular cell adenomas and carcinomas may have been related to mercuric chloride exposure. There was equivocal evidence of carcinogenic activity of mercuric chloride in female F344 rats based on two squamous cell papillomas of the forestomach. There was equivocal evidence of carcinogenic activity of mercuric chloride in male B6C3F1 mice based on the occurrences of two renal tubule adenomas and one renal tubule adenocarcinoma. There was no evidence of carcinogenic activity of mercuric chloride in female B6C3F1 mice receiving 5 or 10 mg/kg. Nonneoplastic lesions associated with exposure to mercuric chloride included increased severity of nephropathy in male rats and male and female mice. There was an increased incidence of renal tubule hyperplasia in male rats. The incidence of forestomach hyperplasia was increased in dosed male and female rats. Increased incidences of nasal mucosa inflammation were associated with mercuric chloride administration in rats. Increased incidences of olfactory epithelial metaplasia in mice were also associated with mercuric chloride administration. Synonyms: Abavit B, calochlor, corrosive sublimate, dichloromercury, mercuric bichloride, mercury chloride, mercury (II) chloride, mercury bichloride, mercury perchloride, sublimate, sulem, bichloride of mercury, corrosive mercury chloride, perchloride of mercury, mercury dichloride Trade name: Fungchex
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PMID:Toxicology and Carcinogenesis Studies of Mercuric Chloride (CAS No. 7487-94-7) in F344 Rats and B6C3F1 Mice (Gavage Studies). 1262 22