Structural studies of a specific polysaccharide isolated from non-agglutinable Vibrio

The purified, specific polysaccharide from Vibrio cholera type NAG, NV 384, O-antigen, 2A, 2B human, contains glucose (5.14%), galactose (4.21%), mannose (64.8%), xylose (3.16%), arabinose (1.98%), fucose (1.50%), mannuronic acid (14.3%), phosphate (0.32%), 2-amino-2-deoxy-D-glucose (2.9%), and 2-amino-2-deoxy-D-galactose (1.0%). Various reactions have shown that the material comprises a phosphoric diester-linked polysaccharide containing mainly ( 1 leads to 2)-linked mannopyranose residues that are highly branched with other sugar residues.

Isolation of a collagen fraction from the body-wall glycoproteins of the leech (Hirudo medicinalis), and characterization of its carbohydrate--amino acid portion

Fractionation of the leech (Hirudo medicinalis) body-wall glycoproteins yielded a collagen fraction containing only D-glucose and D-galactose as its carbohydrate constituents. Digestion of the collagen with trypsin and pronase, and alkaline degradation of the resulting glycopeptides, gave a product that contained a disaccharide linked to hydroxylysine. Mild, acid hydrolysis of the N-acetylated glycopeptides yielded a disaccharide consisting of a D-glucose and a D-galactose residue. Various chemical and enzymic reactions of the disaccharide, the glycosyloxylysine, and the glycopeptide fraction indicated that the disaccharide is 2-O-alpha-D-glucopyranosyl-D-galactose, and that this is beta-glycosidically linked to O-5 of the hydroxylysine residue in the collagen.

Smooth muscle relaxant properties and vasomotor actions of 2-amino-1-p-nitrophenylpropane-1,3-diol

Experiments with the guinea pig ileum, trachea, and vas deferens, the rat fundal strip, the rabbit jejunum and aortic strip, and the toad heart indicated that 2-amino-1-p-nitrophenylpropane-1,3-diol, the hydrolytic product of chloramphenicol, inhibited smooth muscles. Its action was direct and not through any mediators. After intravenous administration, the compound produced vasodepression followed by an overshooting rise of blood pressure. Vasodepression was not mediated by adrenergic, cholinergic, or histaminergic mechanisms. Hypertension was a sympathomimetic effect. Muscle relaxant and cardiovascular effects of the compound were similar to those of chloramphenicol, although it had no antibacterial effect.

Responses of the autonomic nervous system during acclimatization tp high altitude in man

A study has been conducted on 20 sojourners, between the ages of 20-30 years, to evaluate responses of the autonomic nervous system during acclimatization to high altitude. The responses measured consisted of heart rate (HR), blood pressure (BP), oral temperature (Tor), mean skin temperature (Tsk), cold pressor response (CPR), orthostatic tolerance to tilt, and urinary catecholamines. The subjects were tested initially at Delhi (altitude 260 m) and thereafter, on acute induction to an altitude of 3500 m periodically for 3 weeks. For comparison, the same responses were studied on 10 acclimatized lowlanders (AL) who had been staying at the same altitude for more than a year and on 10 high-altitude natives (HAN). The studies showed a rise in HR, BP, Tor, and urinary catecholamines, and a fall in Tsk, CPR, and orthostatic tolerance immediately on arrival at HA, indicating a relative hyperactivity of the sympathetic system. After a stay of 1 week, there was a gradual recovery in all the responses, though sympathetic hyperactivity was still maintained throughout the 3 weeks of stay. In AL also there was a preponderance of sympathetic activity, though of relatively lesser magnitude than that seen in sojourners. In HAN, on the other hand, there was a relative parasympathetic predomination. It has been concluded that in lowlanders it takes more than a year of stay at altitude for complete recovery of autonomic balance.

The influence of testosterone on brain cholesterol

Male sex hormone testosterone propionate induces esterification of brain cholesterol. Esterified cholesterol is absent in the brain of female rats, treatment with male hormone induces esterification. In castrated male rats the esterified cholesterol from brain disappears, whereas supplementation to those animals with testosterone helps in the re-appearance of esterified cholesterol.

Graded-hydrolysis studies on bael (Aegle marmelos) gum

Graded hydrolysis of purified bael gum afforded three neutral and two acidic oligosaccharides, together with monosaccharides. These sugars were identified through periodate oxidation, methylation, reduction with lithium aluminum hydride, co-chromatography, and preparation of crystalline derivatives. The neutral oligosaccharides were characterized as 3-0-beta-D-galactopyranosyl-L-arabinose, 5-0-beta-D-galactopyranosyl-L-arabinose, and 3-0-beta-D-galactopyranosyl-D-galactose, and the acidic oligosaccharides as 3-0-(beta-D-galactopyranosyluronic acid)-D-galactose and 3-0-(beta-D-galactopyranosyluronic acid)-3-0-beta-D-galactopyranosyl-D-galactose.

Partial purification and characterization of RNA polymerase from nuclei of Ehrlich ascites tumor cells

DNA-dependent RNA polymerase (nucleosidetriphosphate:RNA nucleotidyltransferase) was partially purified from nuclei of Ehrlich ascites tumor cells by the techniques of sonic disruption in the presence of 0.3 M ammonium sulfate, ultracentrifugation, salt fractionation, and dialysis. The purified enzyme had an absolute requirement for DNA and was inhibited by actinomycin D and other known inhibitors of DNA-dependent RNA polymerase, but not by rifamycin or rifampicin. The four ribonucleoside triphosphates and Mn2+ ions were also required for optimal activity. Optimal concentrations for Mn2+ and Mg2+ ions and (NH4)2SO4 were 2.4 mM, 6.0 mM, and 0.05 M, respectively. All the native and heat-denatured DNA's that were tested served as templates, but the relative activities with the two forms of DNA depended upon the composition of the reaction medium. Of the natural RNA's and 11 synthetic homo- and heteropolyribonucleotides that were tested, the RNA's, poly(A), poly(A,U), and poly(A,C) were slightly active, but less than 5% as efficient as calf thymus native DNA, with 3H-UTP as the labeled substrate.

Structural investigations of the araban from guava, Psidium guajava L

The pulp of guava, Psidium guajava L., contains an araban which can be enriched by extraction with 70% ethanol. Hydrolysis of the fully methylated pure araban, obtained during fractionation of the methylated polysaccharide, yielded 2,3,5-tri-, 2,3-di-, and 2-O-methyl-L-arabinofuranose in the molar ratio of 1 : 1.04 : 0.93, together with a small amount of arabinose. A structure has been suggested from these results which was corroborated by results from periodate oxidation studies. Sequence of branching has been confirmed from Barry degradation studies. Information about molecular size has been obtained from light scattering measurements.