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Biomedical subjects

M Ketkar

Publications and source records attributed to M Ketkar.

15 recordsLinked to original sources
PubMed1983

[Benzopyrene (BaP) implants into the glottic mucous membrane of hamsters].

For testing the effect of benzo (a) pyrene (BaP) on glottical epithelium European hamsters were used. With laryngofissure hamsters larynges had been opened and a mixture of tricaprilin, beewax and 1 mg BaP was implanted into a pocket formed by mucous membrane of one vocal fold. Compared to typical histology in smoker's larynx, squamous metaplasia and dysplasia and in one case papillary polyps could be described. No squamous cell carcinomata was found.

Animals↗
PubMed1982

A chronic study of praziquantel in Syrian golden hamsters and Sprague-Dawley rats.

Groups of Syrian golden hamsters and Sprague-Dawley rats received 100 mg or 250 mg praziquantel/kg body weight, intragastrically by oral gavage once weekly for 80 weeks and 104 weeks, respectively. In both hamsters and rats the observed differences in tumour incidence, latency and multiplicity revealed no positive dose response effect. Tumours observed corresponded in their origin and morphology to those which develop spontaneously in these species. Haematological and clinico-chemical values were normal. Whereas the average survival time was slightly shortened in rats, female hamsters showed reduced weight gains in the high dose level groups, although water intake and food consumption were increased.

Animals↗
PubMed1979

Investigations on the carcinogenic burden by air pollution in man. Intratracheal instillation studies with benzo[a]pyrene in a mixture of Tris buffer and saline in Syrian golden hamsters.

Syrian golden hamster received intratracheal instillations of 0.125, 0.25, 0.50 or 1.0 mg benzo[a]pyrene (B[A]P) in a mixture of Tris buffer and physiological saline once weekly for life. Papillary polyps, squamous cell papillomas and carcinomas developed in both the larynx and trachea. In addition, bronchiogenic adenomas, adenocarcinomas and squamous cell carcinomas were induced in the lung. The highest incidence of respiratory tract tumours (83%) was seen in hamsters receiving 0.25 mg B[a]P. The results of these investigations are statistically evaluated and discussed.

Air Pollutants↗
PubMed1978

The influence of diazepam and thiouracil upon the carcinogenic effect of diethylnitrosamine in gerbils.

N-diethylnitrosamine (DEN) was simultaneously administered with diazepam (DZP) or thiouracil (TU) once weekly for life to gerbils (Meriones unguiculatus). Additional DZP or TU treatment increased significantly average survival time and inhibited the development of cholangiocarcinomas, although cholangiomas were still observed in these groups. Tumor type and incidence in the nasal cavities were not influenced by DZP or TU. However, in comparison to DEN alone tumor latencies were prolonged.

Adenoma, Bile Duct↗
PubMed1978

Investigations on the carcinogenic burden by air pollution in man. Intratracheal instillation studies with benzo(a)pyrene in bovine serum albumin in Syrian hamsters.

The chronic effect of benzo(a)pyrene (B(a)P) administered intratracheally in bovine serum albumin was studied in Syrian golden hamsters. Dose levels of 0.1 mg, 0.33 mg and 1.0 mg of B(a)P induced papillomas and carcinomas of the trachea, stem bronchi and bronchioles. In addition to such tumours, the mucosa of the respiratory tract revealed a variety of atypical epithelial alterations. Although survival time exhibited a dose-dependency, tumour incidence did not. The incidence of respiratory tract tumours was higher in female hamsters than in males. The results of these investigations are statistically evaluated.

Air Pollutants↗
PubMed1978

Carcinogenic effect of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in European hamsters.

Laboratory-bred European hamsters received intragastric administrations of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) once weekly for 20 weeks. The animals showed mainly squamous cell papillomas and carcinomas of the fore-stomach. The tumour incidence was higher in males (80%) than in females (30%). The average tumour latency was comparatively short (25 weeks).

Animals↗
PubMed1977

The carcinogenic effect of beta-oxidized dipropylnitrosamine in mice. I. Dipropylnitrosamine and methyl-propylnitrosamine.

Di-n-propylnitrosamine (DPN) and methyl-n-propylnitrosamine (MPN) induced mainly respiratory tract neoplasms in female NMRI mice after subcutaneous administration. The majority of tumors occurred in the nasal cavities, although significant incidences were also found in the larynx, trachea and stem bronchi. Treatment with both substances additionally resulted in vascular neoplasms of the liver, while DPN only caused tumors in the pharynx, esophagus and forestomach.

Animals↗
PubMed1977

Tumors of the heart and stomach induced in European hamsters by intravenous administration of N-methyl-N-nitrosourea.

One hundred twenty captured European hamsters (Cricetus cricetus L.) were inoculated iv with 1/5, 1/10, or 1/20 the median lethal dose of N-methyl-N-nitrosourea (MNU) once weekly for 18 weeks. MNU induced mainly sarcomas in the heart and squamous cell carcinomas and sarcomas in the stomach. The highest incidence of such tumors was demonstrated by the lowest-dosage group. They were more frequent in males than in females. The effect of MNU was also localized at the site of administration and resulted in squamous cell carcinomas of the oral cavity. The possible fibroblastic or neurogenic origin of the sarcomas was explored.

Animals↗