Differentiation of cells producing polypeptide hormones (ACTH,MSH, LPH, α- and β-endorphin,GH and PRL) in the fetal porcine anterior pituitary

Summary The aim of the present study on the fetal porcine pituitary was (1) to detect by means of the immunoperoxidase technique the earliest stages of cells producing polypeptide hormones: -MSH, ACTH, -LPH, - and -endorphin, growth hormone (GH) and prolactin (PRL), (2) to study the development of the synthesis and the storage of these hormones during fetal life, and (3) to detect whether several hormones can be located in one and the same cell.The corticotropic cells were revealed as the earliest functional elements of the fetal anterior pituitary. Our results indicate clearly that ACTH, -MSH, -LPH, - and -endorphin appear at 34 days in the same regular, round or ovoid cells; no differences in the time of their appearance could be observed. The ACTH-cells, irregular or angular in shape and endowed with cytoplasmic processes such as described in the adult pituitary, were not seen until day 50. The first GH-cells were detected between 40 to 45 days of fetal life. From day 45 to 90, the GH-cells greatly increased in number and in staining intensity of their progressively extending cytoplasmic area, but they displayed the same regular and round shape. The PRL-cells were the last cell type to appear in the fetal pituitary. The first PRL-cells, small in size and round or ovoid in shape with a high nucleus/cytoplasm ratio, were detected at day 70. At day 80, the PRL-cells increased in size and staining intensity. They displayed an irregular elongated or stellated shape and cytoplasmic processes resembling those characteristic of the adult pituitary. These data suggest that in the fetal porcine pituitary: (1) ACTH, -LPH and related peptides are synthesized and stored in the same cells, and (2) PRL and GH appear in individual cellular elements.     

Del11p13/nephroblastoma without aniridia

Summary A patient is reported with del11p13, low catalase level, nephroblastoma, chordee and cryptorchidism, no evident mental retardation, and with normal irides. This unique observation suggests the following order of loci in 11p13, from centromere to telomere: catalase, Wilms tumor, aniridia. The chromosomal origin of nephroblastoma may be more frequent than estimated on the basis of its association with aniridia.     

“Naked” spinal cord on a non-segmented baton-like bony structure in the tail of the electric fish Eigenmannia virescens (Gymnotoidei)

Summary The caudal spinal cord of Eigenmannia virescens is not enclosed in a neural canal of the vertebral column. In fact, a segmented vertebral column with neural and ventral arches is lacking and replaced by a non-segmented baton-like bony structure on which the free spinal cord is located. The baton consists of calcified bone tissue with bone cells. Individual differences exist as far as the length of the rod is concerned. The electromotor neurons of this caudal part of the spinal cord are histochemically acetylcholinesterase-positive. The electrocytes which surround this part of the spinal cord show strong enzymatic actitivity on the posterior innervated face. However, there is also activity on the non-innervated lateral and anterior faces.     

Interaction of peanut agglutinin,a lectin specific for nonreducing terminal d-galactosyl residues,with embryonal carcinoma cells

Peanut agglutinin (PNA), a lectin specific for terminal d-galactosyl residues, was found to react with embryonal carcinoma cells, but not with their differentiated derivatives. Receptors for PNA were detectable at the surface of all cells of the quasinullipotent F9 line and on only 50% of the multipotent PCC3/A/1 line. The fraction of the PCC3/A/1 population which expresses the F9 antigen was found to be included in the subpopulation carrying the PNA receptors. PNA⁺ and PNA^? subpopulations of PCC3/A/1 were separated by a PNA-mediated reversible agglutination of PNA⁺ cells with rabbit erythrocytes. These subpopulations were essentially F9⁺ and F9^?, respectively.     

Découverte de microfaunes de l'Albienmoyen et supérieur dans la vallée de Joux (Jura Vaudois,Suisse)

The discovery of Foraminifera and Ostracodesin the dark green, sandy-glauconitic marl clay in the Joux Valley (in the Vaudois Jura) suggests to date these sediments Middle and Upper Albian. The Ostracode associations are similar to those found in the Paris Basin, but different from those which characterize the subalpine region.     

Microcalorimetric evaluation of the efficacy of the alkaline treatment on the fermentation of straw

Summary A microcalorimetric study is proposed to follow the degradation of straw by a mixed bacterial culture. The effect of an alkali pretreatment of straw is described.     

Double helical arrangement of spread dinoflagellate chromosomes

Dinoflagellate chromosomes observed in thin section show regular patterns which have been shown to correspond to a liquid crystalline helicoidal arrangement of DNA. Peripheral DNA filaments form a system of loops in the surrounding nucleoplasm. When such chromosomes (studied in Prorocentrum micans) are in presence of water, they extend considerably and form a double helical bundle. At the periphery of these bundles, one observes numerous filaments, which are smooth and devoid of nucleosomes; their diameter is constant.This study, in phase contrast and in electron microscopy, allows statistical measurements. A geometrical model is proposed and shows the simplest way to pass from the intact to the extended form. The liquid crystalline character of the chromosome is probably involved in the extension mechanisms.     

Interaction of melittin with dimyristoyl phosphatidylcholine liposomes. Evidence for boundary lipid by raman spectroscopy

The interaction of melittin, a polypeptide consisting of 26 amino acid residues, with dimyristoyl phosphatidylcholine bilayers was investigated by vibrational Raman spectroscopy. Spectral peak height intensity ratios, involving vibrational transitions in both the 3000 cm^?1 acyl chain methylene carbon-hydrogen stretching mode region and the 1100 cm^?1 acyl chain carbon-carbon skeletal stretching mode interval, served as temperature profile indices for monitoring the bilayer order-disorder processes. For a lipid : melittin molar ratio of 14 : 1 two order-disorder transitions were observed. In comparison to a gel to liquid crystalline phase transition of 22.5°C for the pure lipid, the lower transition, exhibiting a 2°C width, is centered at 17°C and is associated with a depression of the main lipid phase transition of dimyristoyl phosphatidylcholine. The second thermal transition, displaying a 7°C interval, occurs at approx. 29°C and is associated with the melting behavior of approximately seven immobilized boundary lipids which surround the inserted hydrophobic segment of the polypeptide. For a lipid : melittin molar ratio of 10 : 1 two thermal transitions are also observed at 11 and 30°C. As before, they represent, respectively, the main gel to liquid crystalline phase transition and the melting behavior of approximately four boundary lipids attached to melittin. From these data alternative schemes are suggested for disposing the immobilized lipids around the hydrophobic portion of the polypeptide within the bilayer.     

Préparation de cellules isolées de mesophylle deValerianella olitoria Poll,et étude de leur aptitude à l’absorption du 3-O-méthyl-D-glucose

This paper describes a procedure for isolation and preservation of mesophyll cells, adapted toValerianella olitoria. We have tested the best conditions of temperature, pH, enzyme concentration, plasmolysis and the action of several adjuvants, dithioerythritol and mineral nutrients. The method described gives a high yield of viable cells. The ability of isolated cells and cellsin situ to take up methyl-glucose is compared.

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