The saline soils of the ice free dry valleys of Victoria Land, Antarctica may provide the closest analog on Earth to Martian conditions. We have initiated a study aimed at examining microbial adaptations to the harsh environment of these dry valley soils. In this report we describe the characterization of one bacterium, strain A4a, isolated from Taylor Valley soil.
View Article and Find Full Text PDFStepwise modification of a conformationally stabilised analogue of the fragment of somatostatin which had been thought to be essential biologically active moiety has enabled us to synthesise the analogue H-(D) Phe-Cys-Phe-(D) Trp-Lys-Thr-Cys-Thr(ol) code-named SMS 201-995, which in vitro is three times more potent than the native hormone in inhibiting the secretion of growth hormone, which is highly resistant to degradation by pure enzymes and by tissue homogenates, which in vivo in rat and rhesus monkey is (depending on test system) at least 20 times more active than somatostatin, which is much longer acting, and which moreover in both species is much more selective in inhibiting the secretion of growth hormone than that of insulin. The compound is active by several routes of administration including the oral, is well tolerated both in laboratory animals and in man, and is currently undergoing preliminary clinical trial.
View Article and Find Full Text PDFOf the over 3000 people killed in Switzerland through accidents, some 1300 die on the roads, 600 to 700 lose their lives as a result of accidents in the home, and a further number are killed in sporting accidents. these nonindustrial accidents are described in terms of their epidemiology and causes. In addition measures are discussed for preventing accidents in these three areas.
View Article and Find Full Text PDFBrain Res Bull
June 1980
The stability of analogues of Met-enkephalin containing different chemical substitutions in the amino acid sequence to enzymatic degradation by a mouse brain extract and by rat striatal membranes have been compared. On incubation with the mouse brain extract, the naturally occurring Met-enkephalin was completely destroyed within 5 min and 50% of (D-Ala2)Met-enkephalinamide was degraded within 2 1/2 hr, with the release of Tyr, Phe, Met, D-Ala-Gly and partially (D-)Ala and Gly. (D-Ala2, MePhe4, Met(O)ol5) enkephalin (FK 33-824) was degraded to 50% within 5 hr, giving merely Tyr and the tetrapeptide D-Ala-Gly-MePhe-Met(O)ol as degradation products.
View Article and Find Full Text PDFA laboratory study of the interaction of H2O frost with samples of the minerals olivine (Mg,Fe)2SiO4 and pyroxene (Mg,Fe)SiO3 at -11 degrees C to -22 degrees C revealed that an acidic oxidant was produced. Exposure of the frost-treated minerals to liquie H2O produced a sudden drop in pH and resulted in the production of copious O2(g) (as much as approximately 10(20) molecules g-1). Exposure of frost-treated samples to 5 ml of 0.
View Article and Find Full Text PDFSurface oxidation irreversibly removes both oxygen and hydrogen from the martian atmosphere at a rate of 10(8) to 10(11) per square centimeter per second. This rate corresponds to a net loss of 10(25) to 10(28) per square centimeter (10(2) to 10(5) grams per square centimeter) of H(2)O, if it is assumed that the loss rate is uniform over geologic time. Heretofore, exospheric escape was considered to be the principal irreversible sink for H(2)O, but the loss rate was estimated to be only 10(8) per square centimeter per second.
View Article and Find Full Text PDFBull Mem Soc Med Hop Paris
May 2003