Experience with the international standardization of the biological activity of the 3d Standard for streptomycin

The activity of the third International Standard of streptomycin was determined to be equal to 755 IU/mg with the use of accurately weighed amounts of streptomycin and 78037 IU with the use of streptomycin ampoules. The Standardization Center of the WHO decided to use the whole content of the ampoule of the Third International Standard of streptomycin, the activity of which is determined to be equal to 78500 IU per an ampoule.     

Thermal history of reef-associated environments during a record cold-air outbreak event

Summary Several polar continental air masses intruding into the south Florida/northern Bahama Bank region during January 1981 caused record low air temperatures and rapid chilling of extensive shallow-water carbonate systems. Numerous coral kills along the Florida reef tract and massive fish mortalities in Florida Bay were attributable to unusually cold waters generated at this time. Thermal evolution of Florida Bay/Florida reef tract and northern Bahama Bank waters from 8 to 21 January was assessed from thermal infrared data acquired by the NOAA-6 environmental satellite, in situ water temperatures, local meteorological data, and a computerized heat flux model. Field observations and laboratory experiments identify 16°C as a thermal stress threshold for most reef corals (Mayor 1915; Davis 1981). Temperaturecorrected digital satellite data indicated that water temperatures below 16°C were generated in Florida Bay and on Little and Great Bahama Banks during a 10-day period in January. Lowest temperatures on the Florida reef tract resulted from offshelf transport of Florida Bay water through major tidal channels. Offshelf movement of bay water is driven primarily by strong northerly winds, density gradients, and tidal pumping. Absence of reef development opposite major tidal passes along the Florida reef tract (Ginsburg and Shinn 1964) and aperiodic coral kills along bank margins can be attributed to this process, which has probably had a limiting influence on Holocene reef development in these areas.     

Treatment of Raynaud's phenomenon with the 5-HT2-receptor antagonist ketanserin.

The selective 5-hydroxytryptamine2-(5-HT2)-receptor-blocking agent ketanserin was given in a dose of 10 mg intravenously to nine patients with Raynaud''s phenomenon. The effect on blood flow was assessed by photopletysmography and measurments of skin temperature. Digital blood flow and skin temperature increased significantly after ketanserin injection, whereas the placebo (saline 9 g/l) had no such effect. This study suggests that ketanserin may be useful in the treatment of Raynaud''s phenomenon.     

Aspects of petroleum hydrocarbon metabolism in marine animals

Studies on hydrocarbon composition of Black Sea musselsMytilus galloprovincialis sampled from different habitats indicate that the quantity and composition of hydrocarbons distributed in the molluscs depend on season and sea-water quality. The data obtained under experimental conditions testify to the possibility of hydrocarbon concentration in mussel tissues after death. During filtration in sea water containing oil and oil products, these pollutants are bound into faeces and pseudofaeces which contain a greater percentage of aromatic compounds than the oil initially present in sea water. Quantitative data are presented on hydrocarbon changes in mussel excretory products during transfer from oil-polluted to clean sea water. When Black Sea crabsEriphia verrucosa are fed with mussels containing fuel-oil components accumulated from sea water, the pollutants concentrate in the whole body of the crab. This is in contrast to parenteral oil uptake, which leads to a concentration of most of the hydrocarbon in the muscles.     

Size of vasopressin receptors from rat liver and kidney

Specific vasopressin receptors in rat liver membranes were recently characterized [Cantau et al., Journal of Receptors Research, in the press]. They differ from the receptors characterized earlier in kidney membranes as regards coupling with adenylate cyclase and specificity towards vasopressin structural analogues [Rajerison et al. (1974) J. Biol. Chem. 249, 6390-6400; Butlen et al. (1978) Mol. Pharmacol. 14, 1006-1017]. The object of the present work was to see whether these differences reflect a difference in the molecular size of liver and kidney vasopresin receptors. For this purpose, rat liver and kidney membranes were incubated with [3H]vasopressin and solubilized with Triton X-100 (0.3%). The properties of the macromolecular components of soluble extracts to which labelled vasopressin remained bound were observed to resemble those of the intact membrane receptors as regards binding reversibility at 30-37 degrees C and sensitivity to guanyl nucleotides. The hydrodynamic parameters of the soluble hormone-receptor complexes were estimated from Utrogel column filtration experiments and from sucrose density gradient ultracentrifugation experiments. The following values were obtained for liver and kidney receptors respectively: Stokes' radii: 5.4 and 5.6 nm; standard sedimentation coefficients: 3.7 and 3.7 S; partial specific volumes: 0.75 and 0.78 ml x g-1; molecular weight: 83000 and 80000. These results indicate that the marked functional differences between liver and kidney receptors are not accompanied by appreciable differences in molecular size.     

Synthesis of pheromones by stereoselective carbonyl olefination: A unitised construction principle

A route of synthesis for the preparation of unsaturated pheromones is presented. It permits the synthesis of monounsaturated and diunsaturated compounds, with varying position and configuration of double bonds, by stereoselective carbonyl olefination. The choice of appropriate ω-functional aldehydes and phosphoranes makes possible the synthesis of (Z)-alkenols and alkenyl acetates with the double bond in any position desired. Bifunctional synthones are used in stereoselective Wittig reactions for the preparation of diunsaturated sex attractants.