Prostate androgen receptor: immunohistological localization and mRNA characterization

Four androgen receptor (AR) specific monoclonal antibodies were used for the immunohistochemical localization of AR in the human prostate tissue. The prostate tissue consisted of alveoli embedded in fibromuscular stroma and lined with a single layer of columnar secretory epithelial cells. The immunoreactive ARs were found predominantly in the nuclei of epithelial cell, suggesting ARs, like estrogen receptors and progesterone receptors, are mainly nuclear proteins. Northern blot hybridization showed that AR mRNA is about 9 kilobases (kb) and relative abundant in the androgen-sensitive organs, such as ventral prostate, dorsolateral prostate and seminal vesicle.     

Solubility of sickle hemoglobin measured by a kinetic micromethod.

We have developed a photolytic method to determine the concentration of reactive hemes in a solution in the presence of a trace amount of CO. By measurement of the bimolecular rate of CO binding, and by calibration of the rate constant under equivalent conditions, the concentration of the reactive hemes can be determined. In a solution of sickle hemoglobin, the molecules in the gel contribute negligibly to the recombination rate, allowing the concentration of the molecules in the solution phase to be determined. To optimize signal to noise, modulated excitation methods were employed, although the method could also be used with pulse techniques and suitable signal averaging. Because the optical method employs a microspectrophotometer, only a few microliters of concentrated Hb solution is required to reproduce the entire temperature dependence of the solubility previously determined by centrifugation using milliliter quantities of solutions of the same concentration. This should be especially useful for studies of site-directed mutants, and we present results obtained on one such HbS in which Leu 88 beta has been replaced by Ala. The free energy difference in the polymerization of the Leu 88 beta double mutant is consistent with known differences in the amino acid hydrophobicities. The calibration required for these experiments also provides an excellent determination of the activation energy for binding the first CO to deoxy Hb.     

甘蔗细平象的研究

甘蔗细平象Trockorhopalus humeralis Chevrolat是云南甘蔗上的一种毁灭性地下害虫,以幼虫和成虫在地下蔗头内为害,为害期8-10个月。据1989年调查,受害蔗每亩损失500-3000kg,严重的无收。此虫1年发生1代,以成虫在蔗头内越冬,有喜湿性,不能飞翔,主要通过沟河流水传播。在河川坝地,沙壤土中虫口较多;宿根年限越长的甘蔗受害越重。建议蔗稻轮作;缩短甘蔗宿根年限;早春翻挖有虫蔗蔸烧毁;结合新植蔗下种,宿根蔗松蔸培土施用甲基异柳磷或铁灭克等颗粒杀虫剂进行防治。     

人源性流行性出血热病毒的形态特征

本文报道流行性出血热病毒(汉坦病毒)H-114株的电镜形态。发现形态发生以内质网膜和胞浆膜芽生为主。病毒颗粒为圆形或卵圆形。具有双层膜结构,大小为90～120nm。提出了汉坦病毒形态发生的理论观点。     

Activation of a new proline transport system in Salmonella typhimurium.

Proline uptake can be mediated by three different transport systems in wild-type Salmonella typhimurium: a high-affinity proline transport system encoded by the putP gene and two glycine-betaine transport systems with a low affinity for proline encoded by the proP and proU genes. However, only the PutP permease transports proline well enough t allow growth on proline as a sole carbon or nitrogen source. By selecting for mutations that allow a putP mutant to grow on proline as a sole nitrogen source, we isolated mutants (designated proZ) that appeared to activate a cryptic proline transport system. These mutants enhanced the transport of proline and proline analogs but did not require the function of any of the known proline transport genes. The mutations mapped between 75 and 77.5 min on the S. typhimurium linkage map. Proline transport by the proZ mutants was competitively inhibited by isoleucine and leucine, which suggests that the ProZ phenotype may be due to unusual mutations that alter the substrate specificity of the branched-chain amino acid transport system encoded by the liv genes.