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Biomedical subjects

F Renaud

Publications and source records attributed to F Renaud.

108 records · Page 6Linked to original sources
PubMed1988

Characterization of two species of Lepeophtheirus (Copepoda, Caligidae) from flatfishes. Description of Lepeophtheirus europaensis sp. nov.

In the eastern Mediterranean, the copepod Lepeophtheirus thompsoni Baird, 1850, has been reported to infest turbot, brill and flounder. By combining several methods, including enzyme electrophoresis, we show that this species is found only in turbot. By contrast, brill and flounder are infested by a species of Lepeophtheirus that corresponds to no other species reported in the literature. We propose that the species be designated as L. europaensis and we describe the characteristics of the gravid female. This study was extended to the Atlantic populations of flatfishes and includes an investigation of L. pectoralis (Muller, 1776), which infects flounder in the North Sea; we also confirmed the presence of L. thompsoni (Baird, 1850) over the whole geographic range of turbot. Lastly, we discuss the specificity and distribution of these species along the European coasts.

Alleles↗
PubMed1988

Restriction endonuclease analysis of Staphylococcus epidermidis DNA may be a useful epidemiological marker.

We compared the epidemiological markers of 13 Staphylococcus epidermidis strains isolated from an adult inpatient during a febrile episode and 23 S. epidermidis strains isolated during a presumptive outbreak of nosocomial infection in a neonatal ward. The total DNA restriction endonuclease analysis (REA) was processed along with the following conventional markers: biotyping, serotyping, phage typing, antibiotic susceptibility profiles, and plasmid profiles. The REA method was reproducible, giving stable results both in vitro and in vivo. For the hospitalized adult patient, the conventional markers of the 13 strains were concordant and the restriction profiles were identical. Five restriction groups were demonstrated during the course of the outbreak. Within two of the groups, the identities of all of the markers were used to verify whether all of the isolates belonged to the same cell clone. In a third group, combined analysis of the conventional markers and REA had to be used to demonstrate isolate similarity. On the other hand, in another group, none of the markers were similar; interpretation was not easy. An epidemiological study of S. epidermidis infections in hospitals must take into account all of the epidemiological markers: biotypes, serotypes, phage types, antibiograms, plasmid profiles, and REA.

Bacterial Typing Techniques↗
PubMed1984

[The Bothriocephalus scorpii complex (Mueller, 1776). Differentiation of species of parasites of the turbot (Psetta maxima) and the brill (Scophthalmus rhombus). Study of protein fractions and antigen complexes].

Previous electrophoretic studies (Renaud et al., 1983) carried out on the Cestode Bothriocephalus scorpii (Mueller, 1776) showed that the populations parasiting the Turbot and the Brill on the Mediterranean coast, are two distinct species: Bothriocephalus (supra sp. scorpii) gregarius and Bothricephalus (supra sp. scorpii) barbatus respectively. This work has been done with the purpose of identifying these two species by using biochemical tests. The study of whole body proteins by electrophoresis of zones of acrylamide gel shows the existence of nineteen distinct protein fractions in both populations. Among those different protein fractions, two of them (Rf 53 and Rf 87) are present only in the Cestode of the Brill and one (Rf 42) seems to be specific of the Turbot. On the other hand, the fraction of Rf 27 is present only in the Cestodes of the Brill. The immunoelectrophoretic study of antigenic components shows seven or eight major fractions depending on the source of protein, five of them being common to both. The reactions of absorption of antiserum permitted characterization of three arcs of precipitation proper in the Cestodes of the Brill corresponding to protein fractions of Rf (27, 53, 87) and three arcs in the Cestodes of the Turbot, corresponding to protein fractions of Rf (42, 21, 66).

Animals↗
PubMed1983

On the role of serotonin and 5-methoxy-tryptamine in the regulation of cell division in sea urchin eggs.

The presence of serotonin in sea urchin eggs has been ascertained by high-performance liquid chromatography and thin-layer chromatography analysis of tissue-free bioamines. The results show the presence of both serotonin and 5-methoxytryptamine. The role of these substances in the cell division process has been studied by using the serotonin antagonists, gramine and metergoline. Both antagonists cause a significant delay of the cell division which, however, can be prevented by the addition of either 5-hydroxytryptophane, serotonin, or 5-methoxytryptamine. The effect of gramine on the different stages of the cell division process has also been investigated. Neither S phase nor mitosis are affected by the serotonin antagonist, while cleavage is delayed. The effect of serotonin seems mediated by calcium ions and cAMP. Gramine causes a marked increase in radio-calcium efflux from the fertilized egg, and at the same time lowers the cAMP level.

5-Methoxytryptamine↗
PubMed1975

Enzyme immunoassay of progesterone at the picogram level using beta-galactosidase as label.

We report here the first sensitive enzyme immunoassay of a hapten. A progesterone beta galactosidase conjugate was prepared using carbodiimide as a bifunctional reagent. Rabbit progesterone antisera were previously obtained. The separation of the bound from the free fraction of the label was performed with the help of polymerized anti rabbit gamma-globulins. The enzyme activity of the bound fraction was determined with O-nitrophenyl-beta-D-galactoside as substrate. Specificity and sensitivity (approximately 15 pg) of this enzyme immunoassay can be successfully compared with radioimmunoassay performances. It thus provides a non radioactive, inexpensive and reliable method of small molecule quantitation.

Animals↗
PubMedDate not supplied

Rapid isolation of DNA from Actinomyces.

DNA could not be quickly extracted from members of the genus Actinomyces by the usual methods of lysis. Treatment of 7 different actinomyces cells with lysozyme and achromopeptidase, both 5 mg/g wet cells, for 2 h, followed by SDS (0.2%), proteinase K (5 mg/g wet cells) and EDTA (lmM) for 1 h, lysed the cells. The yield obtained in one day was 337 micrograms per 200 mg of bacterial cells. The treatment was also found to work effectively on strains belonging to Veillonella, Staphylococcus, Fusobacterium and Bifidobacterium genera.

Actinomyces↗
PubMedDate not supplied

[Metazoan parasites of Boops boops (Linnaeus, 1758) (Teleostean Sparidae) in the "Golfe du Lion", faunistic and ecology (author's transl)].

A global study of the Metazoan parasites of Boops boops (L., 1758) have been made in the "golfe du Lion". Fourteen different species (eight Platyhelmintha, one Nematoda and five Crustacea) have been inventorized. Their respective localisation on the hosts, globals and specifics corresponding prevalences as well as their variations according to the size of the fish, and their abundance have been precised. Parasitics associations have also been examined.

Animals↗
PubMedDate not supplied

Reproductive and mate choice strategies in the hermaphroditic flatworm Echinostoma caproni.

Due to the important role that mating systems play in the evolution of species, we investigate the selfing rate and mate choice in the simultaneous hermaphroditic parasite Echinostoma caproni (Trematoda). The echinostomes were maintained in two situations in mice: (1) double infections where the two individuals do or do not belong to the same geographic area isolate, and (2) triple infections where two of the three individuals originate from the same isolate and the third one originates from a different isolate. This experimental design permits analysis of intra- and interisolate selfing rates and of mate preference. We predict, in the first experiment, no difference between intra- and interisolate selfing rates. In the second experiment we expect a preferential outcrossing between individuals originating from the same isolate in order to avoid hybrid breakdown. The results obtained corroborate our predictions and emphasize the important and synergistic roles of selfing, inbreeding depression, and hybrid breakdown in the evolution of echinostome reproductive strategies.

Animals↗
PubMedDate not supplied

Atypical strains of Candida albicans recovered from AIDS patients.

By using multilocus enzyme electrophoresis (MLEE) we have analyzed the genetic diversity encountered among chlamydospore-positive Candida albicans strains. While the type II strains of the former C. stellatoidea were genetically indistinguishable from those of C. albicans, type I strains constituted a distinct subgroup compared with C. albicans strains. Nevertheless, all these strains remained genetically very closely related compared with other species of Candida (e.g. C. tropicalis, C. krusei and C. glabrata). These results corroborate the synonymy between C. stellatoidea and C. albicans. Chlamydospore-positive C. albicans strains with atypical sugar assimilation patterns displayed a great genetic divergence from the cluster constituted by C. albicans and the strains of the former C. stellatoidea. However, these atypical strains were more closely related to C. albicans than they were to C. tropicalis, C. krusei or C. glabrata. These strains represent a genetically entity distinct from the typical C. albicans strains used in this study. The data also support the view that the atypical strains described here belong to the same genetic group as atypical C. albicans strains previously described by others.

AIDS-Related Opportunistic Infections↗