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

The data presented concern the evolution of the contemporary increase of stature in eleven countries of Western Europe, at national level and, for some of them, at regional level. The data are based on the average stature of recruits 18-20 years of age. Over the last 20 years, an average increase of 2 to more than 4 cm has been observed according to the countries studied. Over the last one hundred years, the increase of stature is from 3,7 to more than 15 cm. Comparison between the regional means of the stature in four countries and annual rents per capita shows a close relation between stature and conditions of living in Western Europe.

From human plasma of healthy subject, an inhibitor of Na+, K+-ATPase was prepared, using a gel filtration followed by anion exchange chromatography and by HPLC on reverse phase. This low molecular weight (less than 1,500 dalton) inhibitor is a substance which possesses anionic charges, and is absorbed on reverse phase. It inhibits Na+, K+-ATPase activity and the 3H-ouabain binding on human red blood cells.

During the reproductive season in August, we administered to adult male and female Carp an LHRH analog (LHRH-A = D-trp6EA-LHRH) (50 micrograms/kg) alone or in association with pimozide, a dopamine inhibitor (10 mg/kg). LHRH-A caused the circulating portal level of gonadotropin to rise significantly in males and less in females. Spermiation was stimulated in the males and oocyte maturation in females but there was no ovulation. An infection of pimozide and then of LHRH-A 6 h later significantly increased c-GTH secretion and spermiation more than LHRH-A given alone, and induced ovulation in the females.

Esterase B of Escherichia coli has been purified 56 fold with recovery of 39%. The apparent molecular weight as determined by gel filtration was approximately 57000. The pI as determined by isoelectric focusing was 4.6. This enzyme exhibited Michaelis-Menton kinetics with apparent Km of 0.25 mM for l-naphtyl acetate. It remained stable at 60 degrees C but was sensitive to pH values below 6. The esterase activity was completely inhibited by Di-isopropyl-fluorophosphate (DFP) but was resistant to iodoacetamide and to EDTA.

In the MCF7 human breast cancer cells, estrogens stimulate in vitro cell proliferation and biosynthesis of specific proteins which are released into the culture medium; the most abundant of these is a 52,000 dalton glycoprotein. Conditioned media from E2-treated MCF7 cells stimulate the growth of E2-deprived MCF7 cells, whereas conditioned media from untreated control cells are ineffective. At protein concentration greater than 5 micrograms/ml, an inhibitory effect was also obtained with control media. The mitogenic factors of these conditioned media are non-dialysable, sensitive to temperature and proteases and adsorbed on Con A Sepharose. The cell surface of MCF7 cells, examined by scanning electron microscopy, is differentially affected by these two types of conditioned media. We conclude that estrogens may stimulate the growth of breast cancer cells indirectly via the induction of glycoproteins acting as growth factors.

A physiological and anatomical study of the dorsal lateral geniculate nucleus (dlGn) in pigmented C57BL/6 Mice is reported. Neurons responding to the ipsilateral eye are clustered in a region near the medial border of dlGn, and are surrounded by contralateral neurons. Electrode penetrations in this part of dlGn show the existence of contra/ipsi/contralateral projection lines. Practically only the contralateral field of vision is represented in each dlGn. Local HRP injections show evidence in the retina of a decussation line for contralateral retinogeniculate projections, the border of which follows the inner border of the region of ipsilateral projection. The mean diameter of ipsilateral retinogeniculate ganglion cells is larger than that of contralateral cells.

After transformation of Escherichia coli strains with plasmid pBR 322 and growth in rich L medium, the total amount of beta-lactamase produced, strongly decreased when the temperature was raised from 30 to 42 degrees C, but increased after addition of ampicillin or tetracycline to the medium. beta-lactamase was synthesized and exported into the periplasmic space of wild-type strain, but was not significantly released into the extracellular medium, after growth at low temperature. We have identified an E. coli mutant which excreted up to 90% of total amount of beta-lactamase activity, any temperature. This mutant has been used as an indicator strain, for the development of an in situ test allowing the detection of beta-lactamase excretion.