Comptes rendus des seances de l'Academie des sciences. Serie III, Sciences de la vie最新文献

The histocompatibility status of homozygous chicken for B14 and B19 haplotypes of Hy-line stock origin was compared by skin grafts and the mixed lymphocyte reaction. No differences in graft survival (33 days) could be recorded in H-B compatible grafts in either haplotype tested. Reciprocal allografts however (B14 in equilibrium B19) were rejected within 12 days in both haplotypes. A weak stimulation index (1.3-1.9) persisted in individuals serologically identical with respect to the H-B complex whereas a strong index of 10.4 was obtained in allogeneic lymphocyte cocultures.

Intravenous injection of four doses (75, 150, 300, 600 micrograms) of synthetic somatocrinin (GRF 44) greatly increases serum growth hormone concentrations in ten adult normal men in contrast to placebo. Mean peak values were identical. Plasma GH released under GRF stimulation was able to stimulate proliferation of NB2 cells.

The presence of thymulin (formerly called Facteur Thymique Sérique, FTS) in cultured human thymic epithelial cells was studied using a monoclonal anti-thymulin antibody in an immunofluorescence technique. The percentage of thymulin-containing cells increases gradually as a function of time, from 10% at day 4 to 90% at day 14. Furthermore, this increase can be prevented by the addition of thymulin in the culture medium. These data suggest a feedback control of thymulin secretion by thymic epithelial cells.

Turbot larvae were fed on rotifers (Brachionus plicatilis) which had been supplemented with fatty acids. The n-3 long chain polyunsaturated fatty acid (AGLPI n-3, C greater than or equal to 20) requirement of Turbot larvae was estimated above 1.3 g per 100 g dry weight of rotifers.

Efferent connections of the suprachiasmatic nucleus (SCN) in the Rat were evidenced using specific silver impregnation techniques designed to explore degenerating nerve fibers and terminals after a unilateral destruction of the suprachiasmatic nucleus. Suprachiasmatic efferences were confirmed and terminal buttons were identified in the septum, habenula and paraventricular nucleus of the thalamus. In addition suprachiasmatic fibers and nerve endings were revealed in the medial, cortical and central nuclei of the amygdala in the hippocampic subiculum, in different areas of the olfactory system and in the area parolfactoria.

New molecules are described in which an intercalating agent is covalently linked through a polymethylene chain to an oligodeoxynucleotide. Using an oligodT sequence covalently linked to an acridine dye, it is shown that these molecules bind in a specific way to their complementary sequence (poly (A] and that the stability is strongly enhanced by the intercalating agent as compared with the unmodified oligodT. Substitution of a phosphate group by a positively charged group strengthens complex formation and protects the neighboring phosphodiester bond against nuclease cleavage.

A monoclonal anti-MDP antibody was found to bind to "Slow Wave Sleep" factor. This result confirms that this factor is a muramyl peptide and furthermore shows that it contains a structure characteristic of the synthetic adjuvant and of the bacterial cell wall, i.e. an acetylated muramic acid bound to L-alanine. This antibody was also shown to specifically inhibit a biological activity of a purified human monokine which induces fever. Because of these results and other recent observations we propose that a bacterial structure is present in certain mammalian mediators.

Suspensions of motile human spermatozoa, plasma seminal-free, were incubated several days into synthetic medium (C2) with lactate, glucose and phosphate as principal components. Maintenance of forward motility was compared in C2 medium and in known B2 I.N.R.A. medium. C2 medium entertain survival of motile spermatozoa during some days at 20 degrees C. This method of conservation should allow many homologous artificial inseminations by ovulatory cycle avoiding injurious effects of repeated ejaculations or low-temperature conservation.

The biological activity of a synthetic fragment of choleric toxin. gamma Chain A subunit, was studied in vivo. This pentadecapeptide (10-24) was synthesized by solid phase method and finally purified by HPLC. Associated with the B subunit, the peptide inhibits the tissue water loss induced by commercial choleric toxin.

Kinetics and family transmission of antigen specific immune responses were investigated before and 7, 30 and 120 days after booster immunization with tetanus toxoid (TT) in 73 individuals from 12 families. The study of TT specific in vitro lymphocyte proliferative response and of TT antibody levels by radioimmunoassay were performed in parallel; the effect of booster immunization was detectable 7 and 30 days later and still 120 days later for antibody response. No influence of the sex of donors was found. Because of the significant influence on the level of responses of the time interval since last immunization, data were correspondingly adjusted for segregation and linkage analysis. Observations at day 30 were compatible with the hypothesis of control by a dominant genetic determinant for high proliferative responses closely linked to the major histocompatibility complex region.