Are hypertensives less assertive? A controlled evaluation.

Assessed the performance of 12 male hypertensives (mean age 47.36 yrs) in increasingly demanding interpersonal interactions. 12 extended role-played scenes incorporating the expression of positive and negative emotional states were used. Behavioral, physiological, and subjective ratings were obtained. Performance of the hypertensives was compared to that of both patient and nonpatient normotensive Ss who were carefully matched with the hypertensives on a number of demographic variables. Results indicate that the hypertensives responded less assertively on a number of dimensions than did the nonpatient comparison group. However, the performance of the normotensive patient group was similar to that of the hypertensive patients. Physiological and subjective data indicated comparable responding across all 3 experimental groups. The discussion focuses on the existence of a chronic-illness syndrome that potentially has strong behavioral correlates. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Biosynthesis of mitochondrial DNA. Is 8 S DNA an artifact?

Sucrose density gradient fractionation of isolated rat liver mitochondrial DNA ordinarily yields two peaks, one at 39 S, the other at 27 S. However, when these mitochondria are first incubated with a labeled DNA precursor, a labeled peak at about 8 S is also observed. Is this low molecular weight 8 S DNA merely an artifact of contamination or breakdown, or is it a functioning part of the mitochondrial genome? That it is not a nuclear contaminant is shown by: (a) the absence of nuclei or nuclear fragments in active mitochondrial preparations; (b) the insensitivity of 8 S DNA synthesis to treatment of mitochondria with DNase and RNase; (c) the ability of inner membrane preparations to synthesize this DNA; (d) the ability of atractyloside to inhibit incorporation of [3H]dATP into 8 S and 39 S or 27 S DNA equally; (e) the labeling of 8 S DNA (as well as 39 S and 27 S DNA) but not of nuclear DNA after the administration in vivo of [3H]thymidine. The evidence that 8 S DNA is not an artifact resulting from DNA breakdown during mitochondrial incubation or DNA isolation is as follows: (a) 8 S DNA can be isolated from unincubated mitochondrial; (b) 8 S DNA becomes labeled when labeled DNA precursors are administered in vivo; (c) 8 S DNA biosynthesis continues in the complete absence of labeled 39 S or 27 S DNA (whose synthesis is repressed by ethidium bromide), making it unlikely that 8 S DNA is formed from the breakdown of 39 S or 27 S DNA; (d) substitution of milder methods of DNA extraction does not decrease 8 S DNA labeling; moreover, the usual conditions of extraction, when applied to purified 39 S and 27 S DNA, do not generate 8 S DNA, nor does an additional mitochondrial washing cycle; (e) the specific radioactivity of 8 S DNA is higher than that of 39 S or 27 S DNA, making it improbable that the latter forms are precursors of 8 S DNA. Since 8 S DNA is double-stranded, it is not identical to the 7 S fragment of D loop DNA. The hypothesis that the artifactual nicking of those DNA molecules which contain opposing D loops leads to the release of double-stranded fragments was tested. The DNA which was released was predominantly (and probably completely) single-stranded. We conclude that 8 S DNA is probably not an artifact and studies are in progress on its function.     

Volatile constituents of the black currant,Ribes nigrum L.: I. A commercial black-currant distillate

Investigations of a neutral extract of a commercial black-currant distillate by means of gas chromatography and infra-red spectroscopy has revealed approximately 150 components. the following twenty compounds have been identified: α-terpinene, β-phellandrene, γ-terpinene, p-methyliso-propenylbenzene, 1,8-cineole, 2-hexenal, methanol, ethanol, n-propanpl, n-butanol, isobutanol, isopentanol, 2-methylbut 3-en-2-ol, n-hexanol, cis- & trans-hex-2-en-l-ol, terpinen-4-ol, ethyl n-butyrate, methyl n-hexanoate, and methyl benzoate. a further 34 compounds were tentatively identified.     

Passive and active exercises increase cerebral blood flow velocity in young, healthy individuals

Zinc levels in seminal plasma were measured. The study was done on 122, random selected males from infertile couples. The atomic absorption spectrophotometer was used. Sperm density of ejaculate was also determined. These parameters were compared in subgroups: normospermic and oligospermic and in classes of variable oligospermic severity. Semen serum zinc levels in normospermic men was significantly increased as compared to oligospermic men. There were no significant differences in zinc levels between the different classes of oligospermia.     

Biological properties of recombinant alpha-interferons: 40th anniversary of the discovery of interferons

IFNs were first described as potent antiviral agents 40 years ago, and recombinant IFN-alpha2a and IFN-alpha2b were approved for the treatment of hairy cell leukemia just 11 years ago. Today, alpha-IFNs are approved worldwide for the treatment of a variety of malignancies and virologic diseases. Although the exact mechanism of action of IFN-alpha in the treatment of such diseases is not fully understood, many advances have been made in the characterization of the physicochemical and diverse biological properties of this highly pleiotropic cytokine. Here we review recent developments in our understanding of the antiviral and immunoregulatory properties of IFN-alpha, the nature of the multisubunit IFN-alpha receptor, and the molecular mechanisms of signal transduction. Where available, we have included comparative data on recombinant alpha-IFNs derived from both naturally occurring and nonnaturally occurring synthetic genes. We also review clinical data and data on the side effects and antigenicity of different sources of recombinant alpha-IFNs in humans. These latter topics are of clinical interest, because they may potentially affect the efficacy of these various products. Hopefully, what is already known about IFN will prompt further exploration into the mechanism(s) of action of IFN-alpha and thus deliver new applications for this prototypic cytokine, whose full therapeutic potential is yet to be realized.