Endocrine and environmental aspects of sex differentiation in fish

This paper reviews the current knowledge concerning the endocrine and environmental regulations of both gonadal sex differentiation in gonochoristic and sex inversion in hermaphroditic fish. Within the central nervous system, gonadotropins seem to play a role in triggering sex inversion in hermaphroditic fish. In gonochorists, although potentially active around this period, the hypothalamo-pituitary axis is probably not involved in triggering sex differentiation. Although steroids and steroidogenic enzymes are probably not the initial triggers of sex differentiation, new data, including molecular approaches, have confirmed that they are key physiological steps in the regulation of this process. Environmental factors can strongly influence sex differentiation and sex inversion in gonochoristic and hermaphroditic fish, respectively. The most important environmental determinant of sex would appear to be temperature in the former species, and social factors in the latter. Interactions between environmental factors and genotype have been suggested for both gonochoristic and hermaphroditic fish.     

基于色氨酸的生物受体合成与阳离子识别研究

以胺羧配体EDTA、DTPA作为二价模板框架,利用简便方法设计合成了以色氨酸为核心识别单元、含有苯丙氨酸的开链式结构生物受体,并利用荧光光谱和质谱等技术研究了受体与碱土金属离子(Ca2+、Ba2+、Mg2+)和过渡金属离子(Cu2+、Fe2+、Co2+、Ni2+、Mn2+、Zn2+、Cd2+)以及碱金属离子(Li+、Na+、K+)之间的相互作用.结果发现,在水溶液中金属离子与吲哚环之间存在相互作用,这两个受体对多种具有重要生物学和环境保护意义的金属离子有着良好的选择性识别作用.     

四株肺癌细胞系的维甲酸受体表达的研究

目的：观察来源于不同组织学类型的人肺癌细胞系（肺巨细胞癌细胞系PLA-801,肺鳞状上皮细胞癌细胞系C-57,个旧肺腺癌细胞系GLC-82和肺腺癌细胞系PC-84045）的维甲酸受体的含量和分布特征。方法：作ELISA和免疫组化显色计算机图象分析方法,对4株具有不同侵袭潜能,不同组织学类型的肺癌细胞系的维甲酸受体（RARs、RAR和RXRs）进行检测。结果：4株细胞系的RARβ的表达极少,甚至缺如;RARs主要分布在癌细胞胞浆中,但RXRs主要位于细胞核内,表达水平较高;RARs和RXRs在PLA-801细胞中表达最低。结论：肺癌中普遍存在着RAR的表达分布异常,这些改变可能与肺癌的异常分化有关,亦可能是肺癌细胞对维甲酸诱导分化不敏感的重要原因。RXRs较高水平的表达且主要位于核内,提示用9-顺式维甲酸来诱导肺癌的分化效果可能会较好。     

Toll样受体2的研究进展

Toll样受体家族（TOU likereceptors,TLRs）是先天性免疫系统进化过程中形成的非常保守的模式识别受体家族,Toll样受体2（T011-likereceptors2,TLR2）是已经克隆的Toll样受体家族中表达范围最广,识别病原微生物种类最多的成员。它可单独或协同其他Toll样受体家族成员完成对病原体相关分子模式的识别,触发机体对致病微生物的级联免疫应答,尤其是针对细胞毒素的抗炎症反应具有重要的作用,已经成为多种疾病治疗的新靶点。文章对N-SL动物TLR2的分布,结构特征,配体识别,信号转导及其生物学功能的最新研究进展进行了综述。     

Blockade of GABAB receptors accelerates amygdala kindling development

The aim of this study was to investigate the putative role of GABA_B receptors in the development of amygdala kindling in rats. The effects of the GABA_B blocker CGP 35348 and the GABA_B agonist baclofen on the progressive development of behavioural seizure symptoms (stages 1–5 classified by Racine) and duration of afterdischarges (AD) were studied. CGP 35348 at a dose of 300 mg/kg i.p, which blocks central GABA_B receptors, moderately but consistently accelerated the development of behavioural seizure symptoms. CGP 35348 had no marked effect on the duration of ADs corresponding to the different seizure stages. L-baclofen (6 mg/kg i.p.) had a dual effect on kindling development. It retarded the development of the behavioural symptoms, but increased the duration of AD. In conclusion, the results suggest that synaptically-released GABA activated GABA_B receptors and thereby exerted a depressant effect on kindling development.     

Tissue-specific modulation of rat glucocorticoid receptor binding activity by melatonin

The effect of melatonin and 2-Iodomelatonin on nuclear and cytosolic glucocorticoid receptors in the brain, pituitary, thymus and liver has been examined. The results indicate that both melatonin and 2-Iodomelatonin administration is associated with marked changes in the density and the affinity of cytosolic and nuclear forms of glucocorticoid receptors. These observations are discussed in the context of a possible involvement of pineal melatonin in the mechanisms regulating the behaviour and metabolism of steroid receptors.     

液氧中浑浊物分析及处理

通过化学分析手段，分析了液氧浑浊的原因，排查了液氧浑浊可能存在的安全隐患，并根据分析结果，改变了局部工艺路线，达到了消除系统安全隐患、恢复液氧纯度的目的。     

Pituitary gonadotropin releasing hormone (GnRH) receptor levels in intact and ovariectomized-adrenalectomized female golden hamsters on a short photoperiod

Summary Both intact and ovariectomized+adrenalectomized hamsters on a short photoperiod, had a daily surge in plasma LH at approximately 16.00–18.00 h. The number of pituitary GnRH receptors was generally lower in ovariectomized+adrenalectomized hamsters than in intact animals, but both intact and ovariectomized+adrenalectomized hamsters had a decrease in the number of receptors just prior to the LH surge. These results show that gonadal steroids are not involved in regulating the pre-LH surge fall in the number of GnRH receptors.     

性激素诱导大鼠前列腺增生的免疫组织化学研究

Ｗｉｓｔａｒ雄性大鼠６５只分为正常对照组和实验组．后者均做双侧睾丸摘除术，术后３周根据不同的处理方法分为单纯阉割组、雄激素（Ｔ）处理组和不同比例雌雄激素处理组．以免疫组化ＡＢＣ法观察大鼠前列腺腹叶（ＲＶＰ）内雄激素受体（ＡＲ）和雌激素受体（ＥＲ）含量的变化。结果表明ＲＶＰ内ＥＲ变化不明显，ＡＲ含量在各实验组不同：单纯阉割组动物ＡＲ逐渐减少，雌激素（Ｅ２）与Ｔ同时处理较单用Ｔ处理ＡＲ增加更为显著，Ｅ２增加ＲＶＰ内ＡＲ含量的这种作用须在大鼠体内Ｔ大于一定含量时方能实现。提示Ｅ２可通过增加ＲＶＰ内ＡＲ的含量协同Ｔ对ＲＶＰ正常及异常生长的调节作用，本文对这种效应进行了讨论。