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Biomedical subjects

M Duchesne

Publications and source records attributed to M Duchesne.

25 records · Page 2Linked to original sources
PubMed1984

Localization of a neutralization epitope of foot-and-mouth disease virus using neutralizing monoclonal antibodies.

Neutralizing monoclonal antibodies raised against intact foot-and-mouth disease virus reacted with intact particles and with isolated VP1 from different strains from the same subtype. Prior treatment of the virus with either trypsin or with arginine-specific protease abolished recognition of both the virus and of VP1, suggesting the presence of a neutralization epitope in the central region of VP1 cleaved by these two enzymes. A synthetic peptide analogue of part of this region showed poor reactivity, however, with neutralizing antibody.

Animals↗
PubMed1981

The use of highly concentrated purified (by a large scale method) and long term liquid nitrogen stored foot-and-mouth disease viruses for the preparation of vaccines: physico-chemical quality controls and potency tests after storage.

In 1974 a new industrial technique for concentration and purification of FMD virus was presented at the OIE Conference. The bulk inactivated virus from this technique was stored in liquid nitrogen vapour until required for vaccine formulation. In 1981, having applied this technique regularly for seven years, we now describe the results obtained and the advantages gained in the field of trivalent O, A, C bovine vaccine production. Vaccines prepared from such bulk virus stocks after several years storage give good protection against virulent virus challenge.

Animals↗
PubMed1977

Phenylalanine ammonia-lyase in tobacco mosaic virus-infected hypersensitive tobacco. Density-labelling evidence of de novo synthesis.

A strong increase in phenylalanine ammonia-lyase (EC 4.3.1.5) activity occurs in tobacco mosaic virus-infected tobacco leaves developing necrotic local lesions. Comparison of physicochemical properties of the partially purified enzymes extracted from healthy and infected leaves showed that the hypersensitive reaction leads to an increase in the pool size of the same active enzyme molecules as those present in non-infected material. The molecular mechanism of enzyme formation was investigated by radiolabelling with [3H]leucine and by density labelling with 2H2O. Abnormal patterns of incorporation of radioactivity into all soluble proteins were found in infected leaves carrying local lesions. In contrast, uptake of deuterium into the amino acid pool was the same in healthy and infected leaves. Unstimulated phenylalanine ammonia-lyase was shown to be a long-lived enzyme (half-life: 25-35 h). Results of comparative density labelling experiments unequivocally demonstrated that the increased enzyme pool size arose from an increased rate of synthesis mediated by the hypersensitive reaction.

Acid Phosphatase↗
PubMedDate not supplied

The up-regulation of vascular endothelial growth factor in mutated Ha-ras HaCaT cell lines is reduced by a farnesyl transferase inhibitor.

The induction of tumor angiogenesis is mediated in particular by an increased production of VEGF. As ras oncogene is implicated in tumorigenesis, the inhibition of farnesyl transferase activity has recently been developed. The purpose of this study was to evaluate whether expression of mutated Ha-ras oncogene is associated with an altered expression of VEGF in an in vitro model of human skin carcinogenesis and to appreciate the effect of a new farnesyl transferase inhibitor on this VEGF expression. The amounts of VEGF secreted by an HaCaT cell line and two cell clones (metastatic or not) obtained after mutated c-Ha-ras transfection were compared. Our findings showed that the release of VEGF is greater for HaCaT-ras than for HaCaT cells and could be down-regulated using a protein farnesyl transferase inhibitor, in a reversible and dose-dependent manner. These results confirm that the Ha-ras oncogene can contribute to tumor development and progression of epidermal tumors through neoangiogenesis and that farnesyl transferase inhibitors as anticancer drugs may be efficient for the reduction of skin tumor growth.

Alkyl and Aryl Transferases↗