A method for tissue extraction and determination of prostate concentrations of endogenous androgens by radioimmunoassay

A method for simultaneously determining concentrations of major androgens in prostate has been developed. Extraction techniques used to isolate the androgens from minced tissue include homogenization with high-speed blades in Delsal's solvent mixture, adsorption to silica gel, followed by column and one thin-layer chromatography (TLC). Radioimmunoassays (RIA) of small aliquots of TLC eluates are used to quantitate picogram amounts of 5alpha-dihydrotestosterone (DHT) and 5alpha-androstanediols (Diol) and to estimate testosterone (T) and androstenedione (Ad). Contamination of blanks was reduced to RIA sensitivity limits primarily by treatment of glassware in a self-cleaning oven. The specificity of the method for each androgen was established by TLC separations of known prostate metabolites, antisera specificities, and parallelism of sample aliquots to androgen RIA standards. The overall precision, in terms of coefficients of variation, was 21% for DHT and 24% for Diol. T and Ad could not be measured with acceptable precision because their very low concentrations in prostate (less than or equal 0.5 ng/g tissue) were less than RIA sensitivity limits. Accuracy studies indicated recoveries ranging from 96% for Diol to 121% for DHT. In human benign hypertrophic prostate tissue, DHT averaged 153 ng/g soluble protein (5.8 ng/g tissue) which was 17 times higher than values obtained in human spleen and kidney; Diol in prostate showed no consistent differences from values noted in kidney or spleen.     

Environmental interventions for litter control.

In 2 experiments, customers entering a grocery store were given a handbill listing specially priced items, and later the disposal locations of handbills left in the store were recorded. Exp I showed that specific disposal instructions at the bottom of the handbill prompted about 30% of 1,146 handbill recipients to use a particular trash receptacle. Of the 1,231 customers who received no antilitter message on their handbill, only 9% disposed of their handbills in 1 of 2 available trash receptacles, and this percentage did not increase when other customers received specific disposal instructions within the same time period. In Exp II the store was systematically littered on alternate days with 140 handbills. For the littered-store condition a total of 32 out of 639 handbill recipients disposed of their handbills on the floor. However, when the store was free of handbill litter, only 6 of 616 customers dropped a handbill on the floor. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Detection of hepatitis C virus with RNA polymerase chain reaction in fulminant hepatic failure

The role of hepatitis C virus (HCV) infection in fulminant hepatic failure is controversial. The frequency of serum HCV RNA positivity in previously reported patients with fulminant hepatic failure (FHF) of indeterminate cause ranged from 0 to 12% in the United States and Europe and from 43% to 59% in Asia. We assessed serum HCV RNA using polymerase chain reaction (PCR) and oligoprimers from the 5'UTR of the HCV genome in 26 consecutive patients with FHF. Another laboratory independently performed PCR on 21 of the serum samples using different oligoprimers from the 5'UTR and NS3 region of the HCV genome. Serum HCV RNA was detected in two of seven (28%) patients with hepatitis B, 9 of 15 (60%) with an indeterminate cause, and in none with hepatitis A (n = 2) or drug-induced hepatotoxicity (n = 2). HCV RNA PCR results were concordant between both laboratories in 17 of 21 (81%) of samples. In patients with an indeterminate cause, HCV RNA positivity was significantly associated with the transmission risk factor of low socioeconomic status and Hispanic ethnicity. Eighteen patients underwent liver transplantation (LT) and 15 (83%) survived. Among patients with FHF of indeterminate cause, recurrent or acquired HCV infection after transplantation occurred in three of five (60%) and one of four (25%) patients, respectively. Three of four (75%) patients with hepatitis C virus infection post-LT also developed histologic hepatitis. HCV appears to be the causative agent of a substantial number of cases of FHF classified as indeterminate in the Los Angeles area. Differences in patient populations or risk factors may explain the discordant incidences of HCV infection in FHF observed among different programs.     

Influence of fluctuations of the heat-transfer coefficient on the temperature and thermal stresses in a plate quenched in a vibrating fluidized bed of a disperse material

The influence of fluctuations of the heat-transfer coefficient on the evolution of the temperature and thermal-stress fields in a plate is analyzed.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 46, No. 5, pp. 825–829, May, 1984.