Acid phosphatases in germinal and somatic cells of the testes

Four forms of acid phosphatase have been found in the testicular tissue of many mammalian species, but their exact cellular site has remained obscure. In this work, acid phosphatases have been studied in different reproductive organs of the male rat, in somatic cell lines derived by cloning from both rat and mouse testes, in primary cultures of rat Sertoli cells, and in isolated spermatogenic cells of the mouse. Among the reproductive organs, preputial glands show the highest specific activities with p-nitrophenyl phosphate as substrate, followed by the testicular tissue and the different regions of the epididymis. By contrast to that in other tissues, testicular activity with p-nitrophenyl phosphate is not influenced by tartrate and is activated markedly by cobalt (Co2+). Among the somatic cell lines, the highest hydrolysis rates are obtained with naphthyl substrates in the epithelial (TR-1) and myoid (TR-M) cell lines and marginally lower rates in the Leydig (TM3) and Sertoli (TM4) cell lines. With thymolphthalein phosphate, the latter two cell lines show very low activity. These activities are not influenced by different hormones and growth factors in the culture medium. The most marked Co2+-activated reaction with p-nitrophenyl phosphate is found in advanced stages of germinal cells and residual bodies. Primary cultures of Sertoli cells, prepared from rats 10 to 30 days of age, show a slight decrease in acid phosphatase levels; however, the activities are not influenced markedly by addition of follicle-stimulating hormone (FSH) and/or testosterone to the culture medium.(ABSTRACT TRUNCATED AT 250 WORDS)     

Enzymatic esterification in organic media: role of water and organic solvent in kinetics and yield of butyl butyrate synthesis

Summary The respective roles of organic solvent and of water in butyl butyrate synthesis from n-butanol and n-butyric acid in n-hexane by Mucor miehei lipase have been investigated by analysis of the kinetics and the reaction balances. Esterificaton was found to take place in both low water systems containing solid enzyme in hexane and in biphasic aqueous enzyme solution/hexane systems. In the solid enzyme system, the enzyme adsorbed the water produced, thus delaying the appearance of a discrete aqueous phase. As expected, the presence of some water was indispensable for this system, as its removal or exclusion by various means (adsorption, distillation) affected enzyme activity. However, water removal had little effect on the final yield of esterification. Reaction velocities were quite similar for the solid enzyme/hexane system and for the biphasic aqueous enzyme solution/hexane system. In the latter case, the butyl butyrate formed was almost exclusively found in the organic phase. Ethyl butyrate, a more polar compound, was synthesized with a lower yield. These results allow the conclusion that the reaction took place in a phase consisting of either solid hydrated enzyme with no discrete aqueous phase or of an aqueous enzyme solution by basically similar mechanisms according to the amount of water available to the system, the esterification being driven to completion by transfer of the ester into the organic phase because of a favourable partition coefficient. Offprint requests to: F. Monot     

尊重斯德哥尔摩的历史中心—骑士岛的激活改造

瑞典国家财产委员会拥有骑士岛的所有权与管理权，并计划对该岛上所有的公共空间进行更新和开发，以提高其可达性与吸引力。该项目的核心是找到一种更新和修复岛屿的方法，从而在尊重历史价值的同时满足现代功能需求。对骑士岛南部的改造是岛上公共空间更新的第一部分。设计的关键条件是沿滨水区域创造可以供人步行与停坐的大面积空间，并在保持开放海港氛围的同时，对旧的道路铺装进行管理。设计者设计了一套灵活使用公共空间的综合解决方案，将开放空间与之前的码头一样，沿着水滨的形态进行布局。     

Genetic and morphometric studies of the heterogeneity in the testicular defect of the Hre rat and the interaction between the Hre and grc genes

This study was undertaken to examine further the behavior of the Hre gene and its interaction with the growth and reproduction complex genes (grc) in the (Hre x BN)F2, Hre x (Hre x BN)F1 and (BIL/1 x Hre) F2 crosses. The blaze characteristic of rats carrying the Hre gene was linked to testicular weight but not to the body weight or to the major histocompatibility complex (MHC). The Hre defect was genetically unrelated to the testicular defect caused by the grc. The Hre gene had a variable effect on the testes of the rats in different crosses, and it could be categorized into three distinct stages of progressively greater severity. In the cross in which the parents carried the Hre/+ and grc/grc genes, respectively, there was a decreased litter size, an increased male:female ratio in the offspring and poor reproductive performance when compared to a similar cross in which the Hre/+ gene alone was segregating. There was, however, no effect on the severity of the testicular defect. Thus, the grc can interact with the Hre gene to cause embryonic death, which appears to be selective for females, but not to influence the severity of the testicular defect.