大鳍Hu促性腺激素分泌调控的研究

用非洲鲶鱼促性腺激素放射免疫测定方法测定了Ｃｈａｎｇ科鱼类样品中的促性腺激素含量。用这种方法和鲤鱼促性腺激素β－亚基放射免疫测定法测定大鳍Ｈｕ同一批血清样品结果也相当吻合。通过注射促黄体素释放激素类似物和／或多巴胺的Ｄ２受体拮抗剂地欧酮后,定时取样测定血清促性腺激素含量,证明大鳍Ｈｕ促性腺激素的释放同时受到下丘脑分泌的促性腺激素释放激素和多巴胺的双重调节。但是,多巴胺只能抑制由促性腺激素释放激素诱     

大鳍促性腺激素分泌调控的研究

用非洲鲶鱼促性腺激素放射免疫测定方法测定了科鱼类样品中的促性腺激素含量。用这种方法和鲤鱼促性腺激素β亚基放射免疫测定法测定大鳍同一批血清样品结果也相当吻合。通过注射促黄体素释放激素类似物和／或多巴胺的Ｄ２受体拮抗剂地欧酮后,定时取样测定血清促性腺激素含量,证明大鳍促性腺激素的释放同时受到下丘脑分泌的促性腺激素释放激素和多巴胺的双重调节。但是,多巴胺只能抑制由促性腺激素释放激素诱导的促性腺激素分泌,而不能直接抑制基础的促性腺激素分泌,这与非洲鲶鱼相似而与金鱼和鲤鱼等鲤科鱼类明显不同。     

促性腺激素抑制激素与生殖轴的关系

下丘脑的促性腺激素释放激素((GnRH)对调控促性腺激素释放十分重要.10年前在鸟类中首先发现了促性腺激素抑制激素(GnIH),它的鉴定提示GnRH不是唯一能直接影响垂体促性腺激素释放的下丘脑神经肤.GnIH及其同系肽广泛存在于鸟类及哺乳动物体内,GnIH在脑部与GnRH神经接触,GnIH可以直接抑制垂体促性腺激素的合成和释放,GnIH及其受体在鸟类和哺乳动物的生殖腺存在.因此GnIH可以在多个水平直接影响生殖轴:脑部、垂体、生殖腺.     

多巴胺能药物对虎纹蛙GnRH和LH分泌活动的影响

利用在体注射实验和放射免疫测定法,研究了多巴胺能药物对性腺处于再发育期虎纹蛙的促性腺激素释放激素（GnRH)及促黄体激素（LH)分泌活动的影响。结果是：多巴胺（DA）及其激素剂阿扑吗啡（APO）可显著降低血浆LH水平;而多巴胺的拮抗剂－地欧酮（DOM）可显著增加垂体LH含量。DA对脑中cGnRH-Ⅱ的合成有抑制作用,而OM对其mGnRH的释放有一定的刺激作用。结果表明：DA可在脑及垂体水平分别抑制虎纹蛙GnRH和LH的释放,DA对LH释放的抑制作用很可能是通过D2受体实现的。     

大鼠颌下腺促性腺激素释放激素及其mRNA的免疫组织化学与原位杂交研究

用免疫组织化学及原位杂交法,研究了促性腺激素释放激素及其ｍＲＮＡ在大鼠颌下腺的分布。结果显示,大鼠颌下腺的浆液性腺泡的上皮细胞,各级导管的上皮细胞及副交感神经节细胞均呈促性腺激素释放激素免疫反应阳性,阳性反应物质分布在胞质,胞核呈阴性反应。颌下腺的浆液性腺泡上皮细胞,各级导管上皮细胞同样被检测到很强的促性腺激素释放激素ｍＲＮＡ杂交信号。以上结果提示,大鼠颌下腺能自身合成促性腺激素释放激素,促性腺激素释放激素对消化功能可能有重要调节作用。     

根田鼠下丘脑促性腺激素释放激素的放射免疫学测定

利用大鼠促性腺激素释放激素放射免疫学测定试剂检测了根田鼠下丘脑促性腺激素释放激素水平．测定线性范围为2.5 Pg至160pg/管,批内和批间差为1.7％ (n=10)和7.8%（n=4),样品平均标准回收率为108.2±8.4％。根田鼠下丘脑促性腺激素释放激素测定为0.28±0.04 ng/mg湿重组织。从根田鼠下丘脑提取物稀释曲线与大鼠(人工合成)促性腺激素释放激素有较好的平行关系判断, 可以推知根田鼠下丘脑促性腺激素释放激素结构活性类似于大鼠(人工合成)的活性。     

左旋十八甲基炔诺酮对大鼠卵巢颗粒细胞和垂体细胞激素合成及分泌的影响

研究了左旋十八甲基炔诺酮对大鼠卵巢颗粒细胞和垂体细胞激素合成及分泌的直接作用。结果显示左旋十八甲基炔诺酮单独作用于无血清培养的颗粒细胞时,抑制雌二醇的合成,但刺激孕酮的分泌;在与促卵泡素合并处理时,颗粒细胞雌二醇、孕酮的分泌量随着左旋十八甲基炔诺酮浓度的增加而增加。利用促性腺激素生物测定方法证明大鼠整体用左旋十八甲基炔诺酮处理后,垂体中促卵泡素和促黄体生成素活性明显下降;同时外周血清中促卵泡素的活性亦下降。培养的垂体单纯用左旋十八甲基炔诺酮处理后,其培养液经生物测定呈现抑制颗粒细胞雌二醇和孕酮的分泌,促性腺激素释放激素可减弱左旋十八甲基炔诺酮的抑制作用。提示左旋十八甲基炔诺酮除通过垂体卵巢轴系起作用外,还能直接作用于卵巢。     

哺乳动物促性腺激素对文昌鱼卵母细胞成熟的影响

在繁殖季节,将哺乳动物促性腺激素注射到性腺正在成熟文昌鱼体内,注射３６小时后,检查促性腺激素的生理效应,结果表明这两种激素均有效地诱发卵母细胞成熟和产卵。从而认为雌性文昌鱼的生殖活动,像脊椎动物一样,可能受促性腺激素的调控。     

外源激素对雄性黄鳝性类固醇激素分泌的影响

硬骨鱼类促性腺激素(GTH)的分泌受到双重调控,即促性腺激素释放激素(GnRH)的刺激和促性腺激素释放抑制因子(GRIF)的抑制1.       

雌性大鼠离体垂体前叶内在促黄体生成激素释放节律性现象

众所周知,下丘脑促性腺激素释放激素以脉冲形式驱使垂体前叶释放促黄体生成激素,但垂体前叶本身彼和ＬＨ的形式却遭忽略。直到Ｍａｒｃｏ Ｇａｍｂａｃｃｉａｎｉ和谢二发现人和大鼠离体垂体的ＬＨ释放呈节律性。本文目的在于进一步证实是否确定存在ＬＨ释放的内在节律。     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.