Effect of cyclic AMP on fructose utilization, progressive motility and protein synthesis by ram spermatozoa

Ejaculated washed ram spermatozoa showed consistent increases in the intracellular concentration of cyclic 3', 5'-adenosine monophosphate (cAMP) after incubation for 15 minutes with the phosphodiesterase (PDE)-inhibitors, theophylline and caffeine. In vitro addition of cAMP or PDE-inhibitors to ram semen also stimulated and maintained sperm motility and enhanced the rate of fructose utilization. The same doses of cAMP or theophylline significantly stimulated the rate of protein synthesis by the washed spermatozoa, while the PDE-stimulator, imidazole, inhibited protein synthesis significantly. The stimulatory effect of cAMP on sperm protein synthesis was not affected by cycloheximide, but was abolished by the mitochondrial inhibitor, chloramphenicol. The present results indicate a positive correlation between the intracellular concentration of cAMP and the rates of progressive motility, fructose utilization, and protein synthesis by ram spermatozoa. The results suggest that the effect of cAMP is associated with the synthesis of mitochndrial proteins which may be involved with the observed enhancement of sperm motility and metabolism. The data also indicate that cAMP map act either as a first or a second messenger in mature spermatoza.     

Human and rat chromosomal localization of two genes for 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase by analysis of somatic cell hybrids and in situ hybridization

Two genes encoding 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase were localized in human and rat chromosomes. PFKFB1 (previously PFRX), which encodes the liver and muscle isozymes, was assigned to Xq22-q31 in the rat and to Xq27–q28 in the human by in situ hybridization using probes generated by the polymerase chain reaction. PFKFB2, which encodes the heart isozyme of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase, was assigned to chromosome 13 in the rat and to chromosome 1 in the human by hybridization of DNA from somatic cell hybrids. By in situ hybridization, this gene was localized to the regions 13q24–25 in the rat and 1q31 in the human.     

Metal exchanges in the fauna-sediment system. The case of Nereis diversicolor and Scrobicularia plana in the Bou Regreg estuary (Morocco)

This study identifies the types and quantities of metals retained by Nereis diversicolor and Scrobicularia plana in a predominantly arid estuary environment.Certain abiotic parameters and a number of physiological processes linked to metabolic and reproductive functions play a decisive role in the seasonal influence of metal levels on the tissues of these organisms.Given the deposivoric diet of the organisms, the sedimentary bed would appear to be the principal source of metal accumulation.The following classification illustrates the bioaccumulation of metals: 209-1The possibility that these metals may be carried into the estuary by sewage water from the cities of Rabat and Sále should certainly not be ignored.     

Purification of 20α-hydroxysteroid oxidoreductase from bovine fetal erythrocytes

NADPH-dependent 20α-hydroxysteroid oxidoreductase (20α-HSD; EC 1.1.1.149) from bovine fetal erythrocytes was obtained for the first time free of hemoglobin by a new 2,500-fold purification scheme. This was achieved by a sequence of calcium phosphate gel adsorption, ammonium sulfate fractionation, and affinity chromatography. The present results lead us to believe that the NADPH-dependent 3β-hydroxysteroid oxidoreductase activity, which was co-purified with 20α-activity, may originate at the active site of 20α-HSD (2).     

Sulphated heteropolysaccharides from Padina pavonia

Extraction with hydrochloric acid (pH 2.5) of the brown alga Padina pavonia afforded water-soluble and water-insoluble polysaccharides comprising D-glucuronic acid, L-fucose, D-xylose, D-mannose, D-glucose and D- galactose residues. The water-soluble polysaccharide was fractionated by using ethanol, and cetylpyridinium chloride and by chromatography on DEAE-cellulose. A neutral laminaran-like glucan, a sulphated heteropolysaccharide composed of the aforementioned sugars and a protein moiety were obtained. The isolated heteropolysaccharide showed high anticoagulation activity.     

X-ray diffraction study of the molecular association in aqueous solutions of d-fructose, d-glucose,and sucrose

X-ray diffractograms of aqueous solutions of d-fructose, d-glucose, and sucrose, and of two amorphous “solid” forms of these carbohydrates are recorded in the angular range of O 2-16°. The formation, in these diffractograms, of one or two intensity maxima as the concentration is varied is interpreted in terms of modification of the molecular association. A model is proposed that takes account of the state of organization of the solutions of the three sugars as a function of the concentration. Sucrose shows an “anomaly”, as it is the only sugar to establish intramolecular bonds. The number of these intramolecular bonds also depends on the concentration.     

FAMILIAL VALVULAR PULMONIC STENOSIS INVOLVING THREE SIBLINGS

This report describes the cases of three mentally and physically well-developed siblings, 12, 10, and 8 years of age, with varying degrees of isolated valvular pulmonic stenosis not related to age. The severest lesion occurred in the middle patient and was associated with a right-to-left shunt through a patent foramen ovale. The three children had no other siblings, and there was no history of congenital heart disease among close relatives. These cases support the conclusion that genetic factors play a significant role in the development of certain congenital cardiac disorders.     

The length of the Y chromosome in Nubian males and its location in metaphase spreads

Summary A total of 242 metaphase plates from the peripheral blood of Nubian males living near Aswan, Egypt were studied with respect to the length of the Y chromosome and its location in metaphase spreads. The length of the Y was similar to that found in American Negroes, and the Y chromosome was peripherally located in 79 of the 242 cells.