Heterotrimeric G protein signaling functions with dynein to promote spindle positioning in C. elegans.

Proper orientation and positioning of the mitotic spindle is essential for the correct segregation of fate determinants during asymmetric cell division. Although heterotrimeric G proteins and their regulators are essential for spindle positioning in many cell types, their mechanism of action remains unclear. In this study, we show that dyrb-1, which encodes a dynein light chain, provides a functional link between heterotrimeric G protein signaling and dynein activity during spindle positioning in Caenorhabditis elegans.

Control of embryonic spindle positioning and Galpha activity by C. elegans RIC-8.

Asymmetric spindle positioning is of fundamental importance for generating cell diversity during development. In the C. elegans 1 cell embryo, spindle positioning has been shown to depend on heterotrimeric G protein signaling.

Acute effects of drinking beer or wine on the steroid hormones of healthy men.

Plasma Testosterone, Dihydrotestosterone and Estradiol were determined in 72 healthy volunteers, divided into 36 beer and 36 wine drinkers, who consumed between 0.9-2.1 g ethanol/kg b.

Relations between sex hormone levels and sexual behavior in men.

Using a sample of 33 healthy young men, 6 blood samples were obtained in the course of 2 weeks, and testosterone, dihydrotestosterone, and estradiol levels determined. The amount of free testosterone in the saliva was also ascertained for 23 of the subjects. All participants kept a daily record of their sexual activity during the investigational period.

Comparisons of the intra- and inter-individual variability in sex hormone levels of men.

Six blood samples were taken from each of 33 healthy young men during the course of 2 weeks. From these, the testosterone, dihydrotestosterone, and oestradiol levels were determined. In addition, free testosterone was measured using saliva samples obtained from 23 of the subjects.

Sex hormones and stress in the human male.

Six blood samples were obtained from each of a group of 33 healthy males between the ages of 19 and 31, following which radioimmunoassays were used to determine the serum concentrations of testosterone (Tser), 5 alpha-dihydrotestosterone (DHT), and estradiol (E2). In addition, the free testosterone (Tsal) was also measured using saliva samples provided by 23 of the subjects. A questionnaire of our own design was administered together with the Sixteen Personality Factor Questionnaire (16 PF-Test) at the time of the first blood sample in order to check the long-term stress loads of our subjects as well as their abilities to deal with stress.

Fluorogenic substrate turnover in single living cells.

Intracellular diffusion properties and enzyme activities in single living cells can be analysed by means of fluorogenic substrates that diffuse into the cells where they are converted into a fluorescent product by an enzymic reaction. The reaction-kinetic analysis of this process as a system of consecutive reactions provides information on the diffusion of the substrate into the cells, on intracellular enzyme activities and on the efflux of the fluorescent product. Separation of diffusion and enzyme-mediated processes is obtained by inducing specific changes of the cellular membrane using gramicidin D.

[Effect of cromoglicinic acid on the degranulation of mast cells (author's transl)].

An interference microscopic method is described which allows quantitative measurements of the inhibiting effect of the di-sodium salt of 1,3-bis(3-carboxy-chroman-5-yl-oxy)-2-hydroxypropand (cromoglicinic acid; Intal; DSCG) on the degranulation of mast cells in vitro induced by polymixin B and Compound 48/80. The specific degranulation inhibiting effect of DSCG is increased in the presence of Ca++ and Mg++ ions.