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Biomedical subjects

J Tayot

Publications and source records attributed to J Tayot.

At least 55 records · Page 3Linked to original sources
PubMed1980

1-2 Dimethylhydrazine induced colonic tumours in rats.

1-2 dimethylhydrazine was injected subcutaneously on a weekly basis of 15 mg/kg, during periods ranging from one to twenty-eight weeks into five hundred Wistar rats. Glandular-mucin depletion appears as early as the second injection (sulfomucins disappear). From the sixth week, one observes dysplasia; if the animals are allowed to survive for a longer period all will develop colonic carcinomas, which were found mainly in the left colon. This dysplasia, which is first mild, then moderate, is finally severe in rat mucosa or in the area of polyps. Dysplastic polyps become less frequent when carcinomas increase in number and in size. The average length of survival after cessation of the exposure is inversely proportional to the total dose administered. The glandular mucin depletion-dysplasia-carcinoma sequence characterizes the types of formation of 1-2 DMH induced colonic carcinomas. One of the striking features is the early appearance of this sequence.

Animals↗
PubMed1978

Glial fibrillary acidic protein in tumours of the nervous system.

Glial fibrillary acidic protein (GFA) was assayed in nerve-tumour extracts and located in these tumours by indirect immunofluorescence study. We conclude that GFA is a specific marker of both malignant and normal astrocytes. Non-astrocytic tumours (oligodendroglioma, meningioma) do not contain GFA. Tumours with astrocytic differentiation potential (medulloblastoma) may contain GFA. Comparison of microscopic and GFA assays leads us to conclude that GFA concentration is proportional to the amount of malignant astrocytes in the tumour and inversely proportional to the necrotic area of a tumour. Normal tissue GFA and glioblastoma GFA were found to be immunologically identical.

Antigens↗
PubMed1978

[Stages of carcinogenesis of experimental colonic tumors induced with 1-2 dimethylhydrazine].

The authors poisoned 500 female Wistar rats with a dialy dose of 15 mg/kg, The total dose ranged from 15 mg/kg to 420 mg/kg, according to the group. The animals were either killed when the dose defined for each group and been reached, or allowed to live. In a first series of 6 groups (120 animals), the following facts were noted: tumours deeveloped in all animals left alive, after 28 weeks (total dose of 1/2 D.M.H. = 420 MG/KG). Changes in the mucosa were seen from the 40th day on with, in the descending colon, a punctate abnormality involving two or three glandular tubes, in general at the summit of the folds. This abnormality consisted of basophilia of the upper part of the tubes, with a loss of mucus secretion. All transitional stages were seen between this lesion, hyperplasia of the apex of the tubes, the formation of "polyp seeds" and the appearance of polyps. Carcinomas most frequently developed in polyps but sometimes in flat mucosa. In the ascending colon, changes in mucosecretion were seen after a similar time delay at the base of the glandular crypts.

Animals↗
PubMed1978

[Ultrastructure study of the preneoplastic colon (carcinogenesis with 1,2-dimethylhydrazine)].

100 Wistar rats, belonging to a series of 500 animals, were treated with increasing doses and for increasing periods of time with 1,2-dimethylhydrazine. A previous study has shown that tumors begin to appear only after the 19th week. Before this period there are abnormalities of mucin secretion (by the 2nd week), and then there are dysplasic lesions (after the 4th week). The ultrastructure study, done before the 19th week ("pretumor" phase) confirms some previous observations (increase in the zone of mitosis, secretory changes, mutation producing effects). These features are reminiscent of the histochemical characteristics of the human foetal colon. They show an epitheliomesenchymatous disorganisation unrelated to inflammation. There are abnormally early changes in the vasculature, there is loss of the (epithelial) coat, there is dissociation of the basal membrane and abnormal connections between it and the epithelial cells, collagen and fibroblasts; all this represents a disorganisation of the regeneration system of the colon mucosa. This loss of equilibrium between the parenchyma and the mesenchyma may represent a factor favoring excessive and disorganised growth of the mucosa.

Adenocarcinoma↗
PubMed1977

[Fatty infiltration of the heart and Uhl's disease. Apropos of a case of cardiac lipomatosis].

A case is reported of gross lipomatosis of the heart which caused death by gross circulatory failure. The clinical, haemodynamic and angiographic diagnosis was Uhl's disease, and it was the post mortem examination which revealed the massive fatty infiltration of the heart; this involved mainly the right ventricle, but also affected the left ventricle to a major degree. Although fatty deposits in the heart have been recognised for some time, it is surprising to find that there have been extremely few publications on this subject during the last ten years; It is possible that a certain number of case reports of Uhl's disease in adults are really cases of lipomatosis of the heart which have not been recognised as such.

Diagnosis, Differential↗