Science,medicine, and the future. Hypertension.

The abundance of drugs now available for treating hypertension, and evidence that small reductions in blood pressure reverse the associated risk of stroke have shifted clinical concerns away from hypertension. However, we do not understand the cause of hypertension in 95% of patients, fail to achieve a normal blood pressure in 50% of patients, and are unable fully to reverse the cardiac and vascular changes that predate the diagnosis and treatment of hypertension. Consequently, hypertension remains the commonest cause of strokes in Britain and of renal failure in the United States. Essential hypertension is a polygenic disease whose understanding can now be advanced through molecular genetic analyses. Several different syndromes are likely to be recognised; most will be due to interactions between genetic and environmental factors, but there are also likely to be further monogenic syndromes in families with multiple affected members. Recognition of these syndromes will permit accurate genetic prediction of prognosis and optimal treatment and perhaps lead to new and more powerful classes of antihypertensive treatment.     

Hybridization and recombination in the yeasts Pichia alni, P. bimundalis, P. finlandica, P. glucozyma, P. henricii, P. hostii, P. minuta var. nonfermentans, P. muscicola

A collection of genetic lines in 8 reproductively isolated Pichia species has been created. The above data have permitted realizing intraspecific hybridization and showing normal meiotic segregation of auxotrophic markers.     

Age, growth, and reproductive biology of the blackbelly rosefish from the Carolinas, U.S.A.

Otoliths and gonads of blackbelly rosefish Helicolenus dactylopterus dactylopterus were collected from the commercial fishery off the Carolinas in 1994–1997. Opaque bands on transverse sections of otoliths were determined to be annuli by analysis of marginal increments. Opaque zone formation occurs between July and January. Ages ranged from 7 to 30 years. Blackbelly rosefish have intraovarian gestation. Fertilization is internal, as free spermatozoa were found primarily in resting ovaries from July through early December with peak occurrence in September through November. There was a delay of 1–3 months before fertilization, as oocyte development did not begin until December. Occurrence during January through April of early-celled embryos, the most advanced stage observed, and postovulatory follicles indicated that oocyte development was rapid. Egg development occurs in a clear gelatinous matrix secreted into the ovarian cavity. The reproductive mode is a zygoparous form of oviparity, intermediate between oviparity and viviparity. Population sex ratio departed markedly from 1: 1 for most length intervals. Males were more abundant at lengths >250 mm L _T and the overall male: female ratio was 1 : 0·60.     

Genic variation in the coyote,Canis latrans,in Tennessee,U.S.A.

Protein variation, levels of heterozygosity, and interlocality gene variation were studied in the coyote, Canis latrans, using starch gel electrophoresis. Canis latrans were obtained from 27 counties in Tennessee. Eleven of 20 loci examined were found to be polymorphic with the remaining nine loci fixed for the same gene in all populations. Mean heterozygosity (\-H) varied from 0.0% to 1.9% with a mean of 0.9%. These values are low for a mammal. Significant heterozygote deficiencies occurred in most groups. Results of F-statistics indicated a significant degree of population differentiation at four loci (Gdh, Idh-1, Mdh-2, 6-Pgd). Rogers' coefficients of genetic similarity ranged from 0.950 to 1.000 and showed C. latrans to be genetically homogenous in that portion of the range investigated.