Analysis of genetic and environmental sources of variation in serum cholesterol in Tecumseh, Michigan. I. Analysis of the frequency distribution for evidence of a genetic polymorphism.

Analyses of serum cholesterol measurements on 4,619 males and 4,730 females residing in the community of Tecumseh, Michigan, were conducted to estimate the contribution of sex, age, temporal variation, and bimodality to determining the normal variation among individuals sampled without regard to their health status. Female values had a higher mean (2.8 mg/100 ml greater) but smaller variance than males when adjusted by polynomial regression to a common age. Positive skew in the frequency distribution for both sexes was removed by natural logarithm (ln) transformation. Age variation accounted for 28.5% and 29.4% of the variance in a ln cholesterol measurement of males and females, respectively. Between 7% and 10% of the variance in a ln cholesterol value was estimated to be attributable to differences between age-adjusted replicate measurements of the same individual. The reduction in individual variability by adjustment for these contributions to variance will allow a more precise evaluation of the relative contribution of alternate genetic hypotheses as explanations for normal variation in cholesterol. Assuming bimodality, approximately one in 1,000 males and one in 1,000 females belong to a second mode of hypercholesterolemic individuals. The locus determining familial hypercholesterolemia is not a major source of normal phenotypic variation in the Tecumseh population.     

Pulmonary oedema without critical increase in left atrial pressure in acute myocardial infarction.

Twelve patients with acute myocardial infarction and radiological evidence of pulmonary oedema were observed in whom the left atrial pressure, measured indirectly as pulmonary artery end-diastolic pressure, was not critically increased (range 5-12 mm Hg with reference to sternal angle). Eight of the patients had been treated with frusemide, but only six had responded: hence in at least half of the series diuresis could not account for the anomalous finding. Six patients with low cardiac output were given infusions to expand plasma volume. Appreciable increments in mean values for cardiac index (1.6 to 2.0 1/min/m2), stroke index (18 to 23 ml/beat/m2), mean arterial pressure (65 to 86 mm Hg), and pulmonary artery end-diastolic pressure (8 to 15 mm Hg) were recorded. This group, and the remaining six patients with higher cardiac output, survived to leave hospital. Delay in radiographic clearing after a fall of left atrial pressure was a possible explanation for the relatively low pulmonary artery end-diastolic pressures, especially in the patients treated successfully with diuretics. Other mechanisms, such as alterations in pulmonary vascular permeability, might also have contributed to the syndrome. Pulmonary oedema without a critical increase in the left atrial pressure is unusual in acute myocardial infarction but the therapeutic implications are important. Withdrawal;of diuretics may be indicated, and in some cases expansion of plasma volume may lead to striking clinical improvement.     

Prolonged Corticotrophic Action of a Synthetic Substituted α1-18 ACTH

The adrenocorticotrophic effects of a synthetic corticotrophin analogue, α^1-18 ACTH with D-serine¹, lysine¹⁷, and lysine amide¹⁸ substitutions has been studied. It is effective after both intramuscular and subcutaneous administration and compared with tetracosactrin depot (Synacthen depot, Cortrosyn depot) it has a similarly prolonged time course of action—about 24 hours after 0·5 mg and 30 hours after 1 mg. Unlike tetracosactrin depot, however, it is well absorbed when given intranasally and does not produce painful reactions at the site of injection. Its prolonged time course of action does not depend on a formulation designed to delay its release from the injection site but most probably on a decreased rate of degradation in the circulation.     

Design,Synthesis and Antiviral Activity of α-L-Arabinofuranosyl Derivatives of 2-Substituted-5,6-dichlorobenzimidazoles

Abstract

A number of 2-substituted-5,6-dichloro-l-(α-L-arabinofuranosyl)benzimidazoles have been prepared by condensation of 2-bromo-5,6-dichlorobenzimidazole or 2,5,6-trichlorobenzimidazole with tetra-O-acetyl-L-arabinofuranose. 2-Alkylamino derivatives were prepared by a substitution of the 2-chloro group with the appropriate amines. All target compounds were evaluated for activity against HCMV and HSV-1. The 2-chloro and 2-bromo derivatives showed moderate activity against HCMV at non-cytotoxic concentrations.     

Effects of the winter beechmast crop on bird occurrence in British gardens

Capsule Woodland birds were significantly less likely to occur in gardens in years of high beechmast crop.

Aim To test the hypothesis that woodland species that feed on beechmast will have significantly lower occurrence rates at garden feeders in mast years.

Methods Weekly winter occurrence rates at garden feeders between 1970/71 and 1999/2000 for 40 species were analysed in relation to annual beechmast abundance, classified into low, medium and high years. A repeated-measures logistic regression model was used to assess whether beechmast abundance explained further significant variation additional to underlying seasonal and annual trends.

Results Seven species that commonly feed on beechmast showed significantly lower occurrence in gardens in years of highest beechmast abundance: Great Spotted Woodpecker Dendrocopos major, Woodpigeon Columba palumbus, Great Tit Parus major, Coal Tit Periparus ater, Nuthatch Sitta europaea, Jay Garrulus glandarius and Chaffinch Fringilla coelebs. Blackbird Turdus merula and Siskin Carduelis spinus, which showed similar significant patterns, are likely to take beechmast as elements of their diet. Pied Wagtail Motacilla alba was the only insectivorous species to show significant effects, but occurrence was lowest in years of intermediate beechmast abundance. For the latter species, this may have been due to confounding effects of temperature, but there were no such confounding effects of either temperature, or the number of bird feeders provided in gardens, for the other nine species.

Conclusion Use of artificial food sources by birds in gardens is influenced by resources in the surrounding countryside, suggesting that food provided in gardens may play a significant part in the population dynamics of these species, that population monitoring without consideration of the garden habitat may be deficient, and that volunteer-based garden bird recording may provide data that can be used as an indicator of changes in the wider countryside.