PubMed Health⌕ Search

Biomedical subjects

M Vasseur

Publications and source records attributed to M Vasseur.

65 records · Page 4Linked to original sources
PubMed1980

Isolation and characterization of polyoma virus mutants able to develop in embryonal carcinoma cells.

Embryonal carcinoma (EC) mouse cells have been shown to be resistant to infection by retroviruses and small oncogenic DNA viruses, including simian virus 40 and polyoma. When allowed to differentiate, in vitro or in vivo, EC cells become as susceptible to these viruses as differentiated mouse cell lines are. In order to study the relationships between differentiation of EC cells and viral expression, we have isolated and characterized several polyoma mutants that can express early and late functions in undifferentiated EC cells. These mutants, which arose spontaneously during high-multiplicity infection of PCD3 cells (a differentiated fibroblast-like cell line derived from PCC3 EC cells), were selected on PCC4 cells (undifferentiated EC cells) and twice plaque purified. Restriction enzyme analysis of the DNA from several mutants has shown that they all exhibit an additional sequence located in the Pvu II endonuclease fragment 4, close to the junction between Hpa II endonuclease fragments 3 and 5. The size of the insertion varies from 10 to 50 base pairs. The biological properties, including oncogenicity, transforming ability, host range, and burst size of the mutants so far analyzed are similar to those of wild-type virus.

Base Sequence↗
PubMed1979

Do low doses of deoxycholate modify the release of rat jejunal brush border hydrolases?

The in-vivo effects of sodium deoxycholate (DOC) at low concentrations on the release of protein and some brush border hydrolases, sucrase (SA), maltase (MA), leucine aminopeptidase (LA), alkaline phosphatase (AP), have been investigated in the rat by a jejunal perfusion technique. During perfusion with DOC (0.125 or 0.25 mmol/l), enzyme release was not enhanced. After removal of DOC from the perfusion solution with 0.125 mmol/l DOC, there was a steady release of SA, MA and AP although enzyme release was increased linearly in the control and the 0.25 mmol/l DOC groups. The results also confirm the deep localization of AP within the membrane.

Alkaline Phosphatase↗
PubMed1978

Rat intestinal brush border enzymes release by deoxycholate in vivo.

The release of proteins, sucrase (SA), maltase (MA), leucine aminopeptidase (LA) and alkaline phosphatase (AP) activity from rat jejunum by sodium deoxycholate (DOC) was studied by an in vivo perfusion technique. In our experimental conditions, a 2 mmol/1 DOC perfusion for 30 min induced a marked and reversible release of proteins and hydrolases. When specific activities were considered, each enzyme showed a distinct release pattern. Significantly, the SA release was largely increased, the AP release was decreased and there was no correlation between the releases of SA and AP. Furthermore, the various enzymes recovered into the lumen were solubilized at different extents. SA was chiefly present in a soluble and AP in a particular form. The microscopical appearances showed a slight exfoliation of the epithelial cells from the villous tips but no specific changes when compared to the control group. The results are discussed in terms of enzymic localization in the brush border membrane; SA would be located very superficially in the surface membrane and AP buried in the membrane and less accessible than the other enzymes.

Alkaline Phosphatase↗
PubMed1976

Processing of the 17-S Escherichia coli precursor RNA in the 27-S pre-ribosomal particle.

An RNase activity probably involved in the maturation of 16-S pre-ribosomal RNA in Escherichia coli has been partially purified from crude cell extracts. When 27-S ribosome precursor particles are incubated with this enzyme preparation in vitro, their 17-S RNA is converted to a product with the same electrophoretic mobility as mature 16-S rRNA. Fingerprint analysis of this product shows that it contains the 3'-OH but not the 5'-P terminus of mature 16-S rRNA. Generation of the normal 5'-P terminus seems to require a factor present in cell extracts since incubation of the 27-S precursor particle in an extract obtained after centrifugation at 30 000 x g causes conversion of the 17-S RNA to a 16-S species containing both termini of mature 16-S rRNA. Preliminary experiments suggest that correct maturation of the 5' end of the 17-S precursor RNA requires a system in which protein synthesis can take place.

Cell Fractionation↗
PubMedDate not supplied

[Prospective assessment of glycopeptides prescriptions in a general hospital].

OBJECTIVE: The authors had for aim to analyze the indications, quality, and volumes of glycopeptide (GP) prescriptions in all in-patient units of a general hospital. CLINICAL MATERIAL AND METHODOLOGY: A 4 month prospective study assessed the compliance of curative and prophylactic treatment prescriptions administered according to guidelines. The assessment criteria were as follows: prescription indicated or not, prescription modalities (administration of loading dose, performing of serum tests, dosage appropriateness, appropriateness with antibiogram data when available). RESULTS: Over the 46 assessed prescriptions, 84.7% were curative treatments (N = 39), whereas 15.2% (N = 7) were written out for surgical antibioprophylaxis. The prescription incidence and density were, respectively, 0.60 prescription/100 admissions and 20.8 DDJ/1000 hospitalization days, i.e. 24% of the total antibiotics budget. Prescriptions were always indicated for surgical antibioprophylaxis, but met standards in only 14% of cases. As for curative prescriptions, treatments were appropriate in 56.5% of cases, but only 18% met standards. GP use modalities proved incorrect at various levels: non existing load dose and lack of serum tests, subinhibiting daily doses, no dose lowering when possible, exaggerated duration of surgical antibioprophylaxis. Average GP serum levels were 16 mg/L and were higher than the target level in no more than 40% of properly prescribed treatments. CONCLUSION: Prescription modalities and treatment monitoring must be improved, given the development of bacterial resistance.

Anti-Bacterial Agents↗