-
1
المؤلفون: Karen S. Blisard, Deborah A. Harrington
المصدر: Journal of comparative pathology. 103(4)
مصطلحات موضوعية: Central Nervous System, Male, medicine.medical_specialty, Pathology, Hematopoietic System, Biology, Kidney, Median lethal dose, Pathology and Forensic Medicine, Lethal Dose 50, Internal medicine, Testis, medicine, Animals, Blood urea nitrogen, Acute tubular necrosis, Cisplatin, General Veterinary, Dose-Response Relationship, Drug, Endoplasmic reticulum, Ovary, Rana pipiens, medicine.disease, medicine.anatomical_structure, Endocrinology, Liver, Apoptosis, Toxicity, Female, Digestive System, medicine.drug
الوصف: The toxicity of the anti-cancer drug cis-diamminedichloroplatinum (II) (cisplatin), at 2 to 40 mg per kg, was studied in the frog, Rana pipiens. The LD50 for the drug was approximately 17 mg per kg. Major non-nervous system toxicity occurred in the kidney. Renal failure was manifested as anasarca and increasing blood urea nitrogen (BUN). Histopathological changes included acute tubular necrosis and tubular dilatation, which were more severe at higher doses. Interstitial fibrosis occurred after prolonged survival after a single dose. Ultrastructurally, there was increased electron-dense material in tubular cells, but no specific changes in mitochondria or nuclear structures were seen. Gastro-intestinal toxicity was less severe than in other species and was more prominent at higher doses. Pathological changes consisted of epithelial nuclear atypia and apoptosis. By electron microscopy, there was increased separation of cell borders, depletion of chylomicrons and mucin granules and increases in electron-dense material. Again no specific mitochondrial or nuclear changes were seen. Relatively slight changes were seen in the liver, consisting of altered distribution of rough endoplasmic reticulum and dispersion of nuclear chromatin. Minimal pathology was demonstrated in the haematopoietic system or in the gonads. Thus toxicity of cisplatin in the frog is similar to that seen in mammals, including rodents and man.
-
2
المؤلفون: N.F. Suttle, D.G. Jones
المصدر: Journal of Comparative Pathology. 93:143-149
مصطلحات موضوعية: General Veterinary, Pasteurella Infections, Spleen, Organ Size, Superoxide dismutase activity, Biology, medicine.disease, Median lethal dose, Body Temperature, Pathology and Forensic Medicine, Microbiology, Lethal Dose 50, Mice, medicine.anatomical_structure, Liver, Pasteurella haemolytica, medicine, Animals, Female, Pasteurella, Disease Susceptibility, Copper deficiency, Copper, Subclinical infection
الوصف: Mice adjudged copper deficient on the basis of significantly decreased blood and tissue copper content and superoxide dismutase activity, but generally showing no clinical signs of deficiency, were infected intraperitoneally with Pasteurella haemolytica . In 3 separate experiments the LD 50 for deficient animals was significantly depressed below that of copper-sufficient controls. Furthermore, in mice surviving challenge at doses near to the LD 50 , spleen weights were significantly increased and body temperatures depressed in the copper-deficient animals. These results indicate that subclinical copper deficiency in the mouse is associated with an increased susceptibility to experimental infections with P. haemolytica .
-
3
المؤلفون: J.E. Peterson
المصدر: Journal of Comparative Pathology. 88:191-203
مصطلحات موضوعية: Mitotic index, Litter Size, medicine.medical_treatment, Intraperitoneal injection, Mitosis, Spleen, Biology, Kidney, medicine.disease_cause, Median lethal dose, Pathology and Forensic Medicine, Toxicology, Andrology, Pregnancy, medicine, Animals, Pancreas, Dose-Response Relationship, Drug, General Veterinary, Toxin, Lethal dose, Mycotoxins, Rats, Fatty Liver, medicine.anatomical_structure, Liver, Toxicity, Female, Mitosporic Fungi, Injections, Intraperitoneal
الوصف: The toxicity of a crude extract of Phomopsis leptostromiformis grown in lupin seed culture was examined in 2-week-old nursling rats. The extract (subsequently shown to contain approximately 4 per cent toxin on a dry weight basis) was administered as a single intraperitoneal injection. Lethal dose levels caused death in 4 to 8 days; a dose rate of 26·4 mg per kg body weight approximated the LD 50 (i.e. approximately 1 mg toxin per kg). The principal effect of low doses of toxin was metaphase arrest in liver parenchymal cells. At higher dose rates fatty changes and fibrosis developed in the liver and the rats became jaundiced, there was depletion of cortical cells in the thymus and of haemopoietic tissue in the spleen, gastric activity was reduced, and growth rate was depressed. Mitotic arrest was also produced in the kidney and in pancreatic acinar cells by high dose levels of toxin, but not in other tissues. Mitotic arrest in the liver parenchymal cells occurred as a single wave, which commenced within 1 h of the injection of toxin, reached its peak 2 to 4 days after injection and then rapidly declined. As measured by the mitotic index the dose-response relationship was not linear and the measured response was both dose and time dependent. The advantages of rapidly growing animals for toxin assay are discussed and an assay procedure based on the production of a standard mitotic response 18 h after injection of toxin is described.
-
4
المؤلفون: Leah Goldsmit, Erga Barzilai
المصدر: Journal of comparative pathology. 78(4)
مصطلحات موضوعية: Veterinary medicine, Sheep Diseases, Improved method, Chick Embryo, Biology, Median lethal dose, Bluetongue, Virus, Pathology and Forensic Medicine, Injections, Neutralization Tests, medicine, Animals, Yolk sac, Sheep, General Veterinary, Inoculation, Embryo, Isolation (microbiology), Virology, Titer, medicine.anatomical_structure, Virus Diseases, embryonic structures, Injections, Intravenous, Viruses, Cattle
الوصف: Twenty-eight samples from suspected field cases of bluetongue were titrated simultaneously in embryonating chicken eggs by the intravenous and by the yolk sac routes of inoculation. Type 16 virus was isolated from all the 28 samples inoculated intravenously. When they were inoculated into the yolk sac 19 samples tested were positive and 9 were negative. The highest titre of the virus in the intravenously inoculated eggs was 105·0 chicken embryo LD50 per 0·1 ml. The highest titre in the yolk sac was 10 1·7 C.E. LD 50 0·1 ml . Those samples which had a titre of 10 2·7 C.E. LD 50 0·1 ml . or lower after intravenous inoculation were negative by the yolk sac method. When the first egg passages were titrated simultaneously by the intravenous and yolk sac routes the difference between the LD50 titres of the virus in the intravenous and yolk sac inoculated eggs respectively was 3 logs. Embryo mortality following the intravenous inoculation was one hundred per cent. in the first egg passage. The time required for isolation and typing of the virus when this route was used was 10 days. When the yolk sac was used the mortality did not reach one hundred per cent. until the sixth or seventh consecutive egg passage. The time required for isolation and typing of the virus when this route was employed was 7 to 8 weeks.
إعادة تعيين المنقحات
عرض المنقحات (%%عد%%)