Seroprevalence of Kaposi's sarcoma-associated herpesvirus in healthy adults in Israel.

To determine if Kaposi's sarcoma-associated herpesvirus (KSHV) prevalence is correlated with the 9-fold difference in the incidence of classic Kaposi's sarcoma observed among Israeli Jewish populations, we conducted a cross-sectional KSHV seroprevalence survey in a population of 166 HIV-seronegative healthy subjects from the general population (26 women, 140 men). Eight individuals (4.8%) (all men) were seropositive for KSHV; differences between men and women were not statistically significant. If we consider the sensitivity and specificity of the assays, the corrected prevalence would be 6.1% (95% confidence interval 2.0-10.1). We noticed a non-statistically 5.5-fold difference between individuals above and below 40 years of age, but did not find an association with the incidence of classic KS among the Israeli Jewish sub-population, according to their origin. This suggests that KSHV is only necessary, albeit not sufficient, cause of classic Kaposi's sarcoma.

The relationship between glycolysis, mitochondrial respiration, protein-carboxyl methylation and motility in hamster epididymal spermatozoa.

Endogenous protein-carboxyl methylase activity can be measured in intact motile spermatozoa by using [3H]methionine as a precursor of the methyl donor, S-adenosylmethionine (SAM). Since the conversion of methionine to SAM requires ATP, the relationship between the energy metabolism of spermatozoa and methylation was investigated using inhibitors of glycolysis and mitochondrial respiration. When hamster spermatozoa from cauda epididymides were incubated in 12.2 mM glucose, glycolysis was progressively inhibited as concentrations of 2-deoxyglucose (2-DOG) increased. On the other hand, endogenous protein-carboxyl methylation showed a biphasic response being stimulated at low concentrations of 2-DOG and inhibited at higher concentrations. Sperm movement was also altered by 2-Dog. Increasing concentrations of 2-DOG in the incubation medium resulted in an increase in beat amplitude and a corresponding decrease in beat frequency. When the glucose concentration of the medium was reduced to 5 mM, protein methylation was inhibited at all concentrations of 2-DOG. The biphasic effect of 2-DOG on methylation at 12.2 mM and its monophasic effect at 5 mM suggested that this reaction was related to the effective glucose concentration. To investigate this possibility, endogenous protein-carboxyl methylation was measured after incubation of sperm in glucose concentrations ranging from 0-48.8 mM. Low glucose concentrations stimulated protein methylation (up to 6.1 mM for maximal effect), but further increases in the glucose concentration (10-48.8 mM) suppressed the rate of protein methylation to that observed in the absence of glucose. 2-Deoxyglucose decreased conversion of pyruvate to CO2 consistent with diminished mitochondrial respiration. The inhibition of mitochondrial respiration by antimycin A also inhibited endogenous methylation and motility. The results of these studies suggest that maximal endogenous protein-carboxyl methylation in intact spermatozoa from hamster epididymides depends upon active glycolysis as well as mitochondrial respiration.