Search PubMed⌕ Search

Biomedical subjects

N Moreau

Publications and source records attributed to N Moreau.

At least 73 records · Page 4Linked to original sources
PubMed1982

[Value of silver staining technics for the analysis of nucleolar organizer regions and their morphological and functional variations].

Different aspects of nucleolus organizing materiel are found in acrocentric "variants", after specific Ag-staining. These various aspects being linked to the transcriptional activity of rRNA genes, the variant D and G chromosomes do not constitute a homogeneous group. Ag-staining shows also different types of satellite associations, some of them seems more dissociable than others.

Female↗
PubMed1981

Mechanism of action of a 16-membered macrolide. Binding of rosaramicin to the Escherichia coli ribosome and its subunits.

Rosaramicin is a new macrolide antibiotic with activity similar to that of erythromycin. In this paper, we describe the synthesis of [3H]dihydrorosaramicin and show by sucrose gradient centrifugation, gel exclusion chromatography and equilibrium dialysis that rosaramicin and its dihydroderivative bind specifically to the 70-S ribosome and 50-S ribosomal subunit of Escherichia coli. Binding to the 30-S subunit is not detectable. The parameters of the binding interaction were evaluated by equilibrium dialysis. The affinities of E. coli ribosomes for rosaramicin and dihydrorosaramicin are in good agreement with the minimal inhibitory concentration of these drugs for microorganisms.

Bacillus subtilis↗
PubMed1980

[Purification of the bacterial ribosome using chloramphenicol and erythromycin columns].

Chloramphenicol and erythromycin are antibiotics whose target is the bacterial ribosome. We have studied the possibility of isolating the bacterial ribosome by affinity chromatography on chloramphenicol and erythromycin columns. Several columns have been prepared using different spacers and methods of attachment of the ligands (cyanogen bromide, bis-expoxyde). The efficiency and specificity of these columns is discussed. Ethylene diamine is not always suitable as a spacer, because it presents non specific affinity for the ribosome. Pure tight ribosomes have been prepared by ultracentrifugation. They have been compared to ribosomes from affinity columns. These columns have no denaturing effect on ribosomes. They allow a good purification of ribosomes starting from crude bacterial extracts, but the separation of tight couples from loose subunits is not possible.

Chloramphenicol↗
PubMed1977

2"-O-phosphorylation of gentamicin components by a Staphylococcus aureus strain carrying a plasmid.

A wild-type strain of Staphylococcus aureus that inactivates the 4,6-glycosidically linked deoxystreptamine aminoglycoside antibiotics by a plasmid-mediated process was found to harbor two enzymes: an acetyltransferase of the AAC(6') type and a new phosphotranferase specific to the gentamicin components. The target of this last enzyme is the 2''-hydroxyl function of these antibiotics, since one inactivated compound is 2''-(O)-phosphorylsisomicin.

Acetyltransferases↗
PubMed1976

[Analysis of biospecific complexes by electrophoresis: antibiotics specific to bacterial ribosomes].

Electrophoresis is a widespread method in biochemistry. Apparently it has never been used in the study of interactions found in enzyme-substrates or drug-receptor complexes. The aim of this Note is to describe some possibilities given by this simple technique especially in the case of interactions found between some antibiotics and the bacterial ribosome. Chloramphenicol, pristinamycin are located in 50 S subunit whereas dihydrostreptomycin is found in 30 S particle (fig). Such results have been previously obtained by other methods. The distribution of the gentamicin and kanamycin components is quite different. This suggests that the mechanism of action of these molecules may be different from that of streptomycin group antibiotics.

Anti-Bacterial Agents↗
PubMed1976

[45,X/ 46,XX/ 46,XY Mosaic with female phenotype].

Report on a girl with female phenotype and 45,X/46,XX/46,XY mosaicism. The patient showed primary amenorrhea, low stature (1,47 m), but no other typical features of Turner's syndrome. Chromosome studies were carried out on cultures of blood lymphocytes, with usual methods and with R- G- and Q-banding: 43,3 % of cells were 46,XY ; 36,6 % were 45,X and 20 % were 46,XX. The chromosome Y is a non-fluorescent one. A comparison is made with other published cases.

Amenorrhea↗
PubMed1975

[Gonad development and differentiation in the golden hamster].

Development and gonadal differentiation in the Golden Hamster embryo are studied from day 9 of development to adult stages by means of histological, histochemical and cytogenetical techniques. The gonad appears on the day 9 of development and remains in an indifferentiated stage until day 11, testicular differentiation is carried out from day 12 with testicular cords and Leydig cells. Ovarian differentiation occurs later from day 14 of development and is practically recognizable after birth.

Animals↗