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M Rousset

Publications and source records attributed to M Rousset.

89 records · Page 5Linked to original sources
PubMed1977

[Immunological demonstration of large quantities of glycogen or of a glycogen-like substance in human embryonic colon cells and in colon carcinomas by means of rabbit antisera raised against a strain of Escherichia coli 013].

Rabbit antisera raised against a strain of E. coli 013, with a strong antiglycogen activity, were tested on human fetal and normal adult colons, on colon carcinomas, and on colon tumor cells in culture (HT29). Only very rare granules were present in adult normal colons when tested with the immunofluorescence method. In faetal colons, in 12 out of 14 carcinomas, and on HT29 cells, the immunofluorescent reactions were similar to those observed in normal liver. The reactions were negative after previous treatment with alpha-amylase. They were inhibited with glycogen, with phenol-alcohol, perchloric, and trichloroacetic extracts from faetal colons, and with a tumor trichloroacetic extract. The extracts precipitated with anti-E. coli 013 antisera. They had a strong inhibiting activity in a radioimmunoassay test with labeled glycogen. The extracts from normal adult colons did not precipitate with the antisera and they had no inhibiting activity in either immunofluorescence and radioimmunoassay tests.

Adult↗
PubMed1977

Radioimmunoassay of the WZ polymorphic antigens of normal human colon and their relationship with ABH antigenic determinants.

Heat resistant, high mol. wt glycoproteins of the three WZ phenotypes (W+Z+, W-Z+ and W-Z-) were extracted from normal human colonic mucosa and labelled with 125I. More than 80 per cent of the radioactivity of the W+Z+ antigens labelled with I125, was precipitated by natural or immune anti-W antibodies. About 60 per cent of the W-Z+ 125I-labelled antigens were precipitated by immune anti-Z antibodies. No specific precipitation could be detected with W-Z- 125I-labelled antigens. All the precipitin reactions were quantitatively inhibited with the crude antigen extracts of the corresponding phenotypes. The W and Z antigens were only found in the intestinal mucosa and there was a 100-fold increase in the relative concentrations between the small bowel and the rectum. As opposed to this, the ABH antigens were found in all the digestive secretions studied, except those of the rectum, and their relative concentrations progressively decreased by about 100 between the small intestine and the recutm. The decrease in ABH concentration seems to be correlated to a WZ increase in the same regions.

ABO Blood-Group System↗
PubMed1976

[Antiglycogen activity of rabbit antisera raised against a strain of Escherichia coli 013].

Rabbit antisera raised against a strain of E. coli 013 (Su 4321/41 013 K11 H11) contain high titres of antiglycogen antibodies. This activity was evidenced through positive immunofluorescent reactions observed on liver and muscle sections. Such reactions disappeared when the sections were previously treated with alpha-amylase. They were inhibited with Oyster glycogen, phenolalcohol, perchloric acid, and trichloroacetic liver extracts. These same substances had no inhibiting activity when treated with alpha-amylase. The immunofluorescent reactions were negative on livers from Mice treated with endotoxins and insulin which are known to deplete the stores of liver glycogen. The antisera gave interfacial precipitates with glycogen and liver extracts. The same substances, as well as the LPS from E. coli 013, had a specific inhibiting activity in a radioimmunoassay test using glycogen linked to bovine serumalbumine labeled with 125I.

Animals↗
PubMedDate not supplied

Glucose-dependent transcriptional regulation of the human sucrase-isomaltase (SI) gene.

We have previously shown that the transcription of the human sucrase-isomaltase (SI) gene was negatively regulated by glucose. Using two clonal metabolic variants of the human colon adenocarcinoma cell line Caco-2 we demonstrate here that: 1) although similar growth-related variations of phosphoenolpyruvate carboxykinase (PEPCK), frutose 1,6-diphosphatase (F1, 6-dPase), pyruvate kinase (PK) and SI mRNA levels are observed, only F1,6-dPase, PK and SI mRNA levels vary in the same way in response to modifications of glucose utilization; and 2) regulatory elements responsible for the glucose-dependent transcription of the SI gene are located within the -370/+30 region of the promoter.

Cell Differentiation↗
PubMedDate not supplied

Intestinal responses to xenobiotics.

The gastrointestinal tract represents the first barrier met by the exogenous compounds of food or orally delivered drugs. To be transferred to the whole body, drugs and xenobiotics have first to pass through the intestinal epithelium, where detoxification systems have to minimize the potential of damage from toxic xenobiotics. However, most studies on xenobiotic-metabolizing enzymes have focused on liver enzymes. Such a situation may be explained by the fact that this organ is the site of toxification/detoxification for both endogenous and exogenous compounds, and also because adequate in vitro hepatocytes models have been available for a long time. By contrast, normal cellular models for the in vitro study of the intestinal processes of biotransformation still remain difficult to obtain. In the present report we will thus focus on the most commonly used models, which are Caco-2 cells and their derivative clones, and we will report recent procedures that allow the isolation of normal enterocytes which maintain their functions and integrity for several hours or even several days. Their respective performance and advantages for the study of the induction of the drug-metabolizing enzymes will be discussed.

Animals↗
PubMedDate not supplied

[Polymorphic secretory antigens (WZ) of the human adult and fetal colon].

The present paper concerns further data about the WZ polymorphic antigens of the human colon. A population study conducted with the immunofluorescence technique on rectal biopsies from 150 subjects, confirmed the frequency of the three phenotypes : W+Z (0.65), W-Z+ (0;25), W-Z- (0.10). The same three phenotypes were observed with the immunofluorescence technique in the colon goblet cells of 20 foetuses ranging in ages from 20 to 36 weeks. In these foetuses a comparative study of the WZ and ABH antigens along the length of the gastrointestinal tract showed the same reverse distribution of the two kinds of antigens as previusly reported in the adult. The comparison of the inhibition activity of adult or foetal colon mucosa extracts in a radioimmunoassay test showed that the WZ antigens are similarly present in heated water, phenolalcohol, and perchloric acid extracts. The WZ antigens are present in the meconium.

Colon↗