Histochemical demonstration of asparagine-linked oligosaccharides in glycoproteins of human placenta and umbilical cord tissues by means of almond glycopeptidase digestion

Almond glycopeptidase is an enzyme which cleaves specifically beta-aspartylglucosylamine linkages in glycoproteins with asialo-carbohydrate moieties. With this enzyme, it was possible to demonstrate the localization of asparagine-linked oligosaccharides in glycoproteins of human placenta and umbilical cord tissues. In these tissues, the oligosaccharides were shown to react positively for a series of histochemical procedures for neutral complex carbohydrates such as periodic acid-Schiff (PAS), peroxidase-labelled Ricinus communis agglutinin-I-diaminobenzidine (PO-RCA-DAB) and concanavalin A-peroxidase-diaminobenzidine (Con A-PO-DAB). The asparagine-linked carbohydrates were localized in the placental villi, blood vessels and perivascular tissues and the umbilical cord blood vessels and matrix. The results of previous biochemical analyses performed upon the same tissues (Takahashi et al., 1981) have corroborated the results of the histochemical studies. The present results appear to substantiate the usefulness of almond glycopeptidase for the histochemical demonstration of the particular oligosaccharides of glycoproteins in tissues in general.     

Intergenus cell fusion between L-form cells of Pseudomonas aeruginosa and Escherichia coli

Intergenus cell fusion of prokaryotic bacteria was demonstrated for the first time; namely, fusion products doubly resistant to streptomycin and tetracycline were produced by polyethylene glycol treatment of a mixture of the streptomycin-resistant L-form of Pseudomonas aeruginosa and tetracycline-resistant L-form of Escherichia coli.     

Stimulation of eicosapentaenoic acid metabolism in washed human platelets by 12-hydroperoxyeicosatetraenoic acid

Washed human platelets were not able to convert eicosapentaenoic acid (EPA) to thromboxane B3 (TXB3) and 12-hydroxyeicosapentaenoic acid (AA) to washed human platelets induced conversion of EPA to TXB3 and 12-HEPE. Esculetin, a specific inhibitor of 12-lipoxygenase, prevented the effect of AA, but cyclooxygenase inhibitor did not. The conversion of AA to TXB2 was not affected by the same dose of esculetin. These data suggest that products of AA formed by 12-lipoxygenase in human platelets have stimulatory effects on EPA metabolism. When AA was preincubated with washed human platelets, its effect on EPA conversion was reduced, suggesting that a labile product of AA formed by 12-lipoxygenase is involved in the facilitation of EPA metabolism. Addition of 12-hydroperoxyeicosatetraenoic acid directly to washed human platelets caused dose-dependent synthesis of TXB3 and 12-HEPE, while addition of 12-hydroxyeicosatetraenoic acid had no effect. Thus, 12-hydroperoxyeicosatetraenoic acid formed from AA promotes the metabolism of EPA in washed human platelets.     

Identification of Cytokinins in Root Exudate of the Rice Plant

Cytokinins, cis-zeatin and cis- and (trans-ribosylzeatin, wereidentified in the root exudate of the rice plant (Oryza sativa,indica cultivar IR-24) after several chromatographic separationsand combined gas-liquid chromatography-selected ion monitoring(GC-SIM) analysis. The presence of trans-zeatin ribotide wassuggested by enzyme hydrolysis, subsequent chromatographic separationand GC-SIM. The comparatively high content of the ribotide inthe root exudate suggests the form of cytokinins to be transportedfrom roots to other parts in the rice plant. (Received July 22, 1982; Accepted November 25, 1982)     

Thermal shock hemolysis in human red cells. I. The effects of temperature, time, and osmotic stress

Thermal shock is a form of hemolysis which occurs in human red cells exposed to greater than a critical level of osmotic stress of 1.4 Osm and subsequently cooled from above about 12 degrees C to below that temperature. Higher concentrations and higher cooling rates each increase the amount of hemolysis, within limits. Incubation for varying periods in hypertonic solutions and varying temperatures of incubation affect the amount of thermal shock. The effect of cooling rate on thermal shock is independent of the period of exposure to hypertonic solutions. Thermal shock is not the cause of freezing injury in human red cells, at least above -10 degrees C.     

Molecular cloning of the human gastrin gene.

A genomic clone that contains the human gastrin gene was isolated from a human gene library. Restriction endonuclease mapping and DNA sequencing analysis revealed that this gene is about 0.7 kb long, and has an intron. The intron is located at a position that separates the coding region into the peptide region essential for biological activities of gastrin and the non-essential, N-terminal peptide region.     

Release of LH after administration of an analog of synthetic LH-RH in cattle

The $\text{in vivo}$ effect of an analog of LH-RH, (Des-Gly-NH₂¹⁰, Proethylamide⁹)-LH-RH, on LH release, was studied in one bull with azooapermia, and one cow with cystic follicle. The single intravenous injection of 100 μg LH-RH analog caused abrupt and marked increase in serum LH and the high levels of LH were maintained for 3 hours. The highest levels of serum LH were 48 and 114 times as high as the pre-treatment levels in a bull and a cow, respectively. Further studies are being undertaken to evaluate this compound for improving reproductive function in cattle.