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Biomedical subjects

M Lucas

Publications and source records attributed to M Lucas.

At least 235 records · Page 13Linked to original sources
PubMed1978

Four years' experience of antenatal chromosome diagnosis.

The culture of fetal cells obtained by amniocentesis has become a useful and often reassuring investigation for couples having an increased risk of giving birth to an abnormal child. The present report illustrates the experience at one center where the work has been carried out for a number of years.

Adult↗
PubMed1977

Distribution of human chromosomes on the metaphase plate using banding techniques.

This study deals with the problem of distribution of the 46 centromeres on the human metaphase plate after treatment with colchicine and hypotonic shock. The location of the centromeres was recorded for 400 metaphases in which the chromosomes were identified by bands. A quantitative analysis of chromosome distribution ascertains the absence of proximities between homologous chromosomes. The already known ones between acrocentric chromosomes are found at a very high level. The nature and intensity of these proximities vary from one sample to another as is the case between heterologues. A three-dimensional graphic technique is proposed to summarize all of the interchromosome proximities.

Cell Cycle↗
PubMed1977

Detection of rotavirus in experimentally infected piglets.

Scouring and vomiting was induced in piglets by experimental infection with a field strain of rotavirus. Virus or viral antigen was detected in the small intestine by the fluorescent antibody technique and virus could also be demonstrated in infected tissue culture cells by immuno-fluorescence. Progeny particles in the epithelial layer of the small intestine were identified by electron microscopy. Three morphological types could be distinguished, often associated with electron-dense inclusion, and infected cells, though small in number, were present throughout the length of the small intestine.

Animals↗
PubMed1975

[Influence of glyoxylic acid on properties of isolated mitochondria].

Glyoxalate is an effector of oxidative phosphorylation in isolated mitochondria : it slows down State 3 but does not affect State 4 respiration. This report presents the findings of our study on the mechanism of action of glyoxalate ; these findings are listed below. The inhibition of Stage 3 respiration by glyoxalate does not set in immediately, can be reversed in part by the addition of an uncoupling agent or a dithiol, is non-competitive against succinate and can be demonstrated with substrates requiring the involvement of other membrane transport systems. Glyoxalate prevents the increased oxygen uptake stimulated by 2,4-DNP or Sr++. Glyoxalate also inhibits phosphate transport and this inhibition can account for most of the effect observed. The inhibition of State 3 respiration is paralleled by a decrease in the mitochondrial accumulation of succinate : this decrease could arise from a direct effect of glyoxalate on dicarboxylic acid transport or could be the result of an inhibiton of the phosphate transport system, which is connected with the former. The decrease in the respiratory rate of uncoupled mitochondria placed in a phosphate free medium demonstrates that the effector acts directly at the substrate transport or/and electron transfer level. Phosphate, by delaying the respiratory inhibiton due to glyoxalate, has a protecting effect on mitochondrial functions. Glyoxalate is thus acting at several mitochondrial sites. It acts presumably by forming hemimercaptals, blocking sulfhydryl groups. Its effects can be accounted for by the unfolding of such (hemicercaptal) groups under the influence of ADP, Pi, uncoupling or others agents which bring about conformational changes in the internal mitochondrial membrane.

Animals↗