Biomedical subjects

M D Reuber

Publications and source records attributed to M D Reuber.

167 records · Page 10Linked to original sources

PubMedDate not supplied

Carcinomas of the liver in Osborne-Mendel rats ingesting DDT.

Osborne-Mendel male and female rats ingested 200, 400, 600, or 800 ppm DDT composed of 81.8% p,p isomer and 18.2% o,p isomer for periods up to 2 years. Male and female rats developed highly significant incidences of hepatocellular carcinomas. The carcinomas varied from well-differentiated to undifferentiated. There was a highly significant increase in carcinomas of the ovary in treated female rats. Lymphosarcomas were also increased in DDT-treated male rats.

Animals↗

PubMedDate not supplied

Carcinogenicity of captan.

Two studies on the carcinogenicity of the fungicide captan in animals were reviewed. The results and conclusions, which were based on my examination of the histological sections, showed that captan is highly carcinogenic in rats and mice. Neoplasms at all sites, as well as malignant neoplasms, were increased in both low and high dose captan-treated male and female rats. Benign and malignant neoplasms of the endocrine organs were increased in low and high dose male and female rats ingesting captan. Neoplasms of the adrenal and pituitary glands were increased. Increased incidences of benign and malignant neoplasms, and of malignant neoplasms only, were observed in the reproductive system of female rats ingesting captan. The incidence of these neoplasms was markedly increased in the mammary gland and ovary. Female rats given captan were more susceptible to the development of hepatic neoplasms than were male rats. Captan induced neoplasms of the duodenum in male and female mice. There also were toxic changes in rats. Captan-treated male rats were more susceptible to the induction of chronic renal disease than were female rats. Male rats also had a high incidence of particularly severe testicular atrophy as a result of the ingestion of captan. Such lesions interfere with the health of the rats and with the development of neoplasms.

Adrenal Gland Neoplasms↗

PubMedDate not supplied

Ultrastructure of liver tumors induced in F344 rats by methapyrilene.

Liver tumors induced in F344 rats by methapyrilene were studied by electron microscopy. The tumor cells constituting hepatocellular carcinomas showed a pronounced increase in the number of mitochondria and conformational changes of these organelles while the content of lipid, glycogen and smooth endoplasmic reticulum was greatly reduced. The cholangiocarcinomas consisted of bile duct epithelia at varying stages of squamous metaplasia.

Adenoma, Bile Duct↗

PubMedDate not supplied

Carcinogenicity of heptachlor and heptachlor epoxide.

Heptachlor and its metabolite heptachlor epoxide are unequivocally carcinogenic in rats and mice. The chemicals induced carcinomas of the liver, which were highly significant. There were neoplasms at other sites in rats. Neoplasms at all sites, as well as malignant tumors, were increased in heptachlor-treated male rats. There were similar increases in benign and malignant neoplasms of endocrine organs, particularly in female rats. Neoplasms of the thyroid and pituitary were increased in male rats and neoplasms of the reproductive system, including the ovary and uterus, in female rats given heptachlor. Mice also developed hepatic vein thrombosis and thrombosis of the atria of the heart. Nephritis, myocarditis, encephalitis, hepatitis, polyarteritis and atrophy of the testes were observed in rats.

Animals↗

PubMedDate not supplied

The carcinogenicity kepone.

Kepone is unmistakably carcinogenic in rats and mice. Kepone induced malignant tumors in the liver of rats and mice in the NCI studies and in the liver in rats in the Medical College of Virginia study. Malignant tumors were also found in organs other than the liver in rats in both studies, including the lowest dose administered. Female rats given Kepone were more susceptible to the development of malignant tumors than were male rats. There also were toxic changes, particularly in male rats, ingesting Kepone. These lesions include interstitial fibrisos of the kidney, polyarteritis of the mesenteric, pancreatic and other arteries; and atrophy of the testes. Such lesions generally interfere with the health of the rats and with the development of tumors. Atrophy of the testes would also prevent reproduction.

Animals↗