室旁核在刺激猫肾神经传入纤维引起的血压效应中的作用

本研究的目的是在氯醛糖麻醉、颈动脉窦、主动脉弓去神经和切断迷走神经的猫中探讨室旁核和室旁核α_1肾上腺素受体在刺激肾神经传入纤维引起的升压反应中的作用。刺激肾神经中枢端可引起动脉血压明显升高。这种血压升高由两个成分组成。第一成分可被植物性神经阻断剂六烃季铵和阿托品所阻断,第二成分不能被植物性神经阻断剂所阻断。双侧室旁核毁损后,植物性神经阻断前、后刺激肾神经中枢端引起的升压反应都明显减弱。侧脑室和室旁核微量注射α_1肾上腺素受体拮抗剂哌唑嗪,可显著抑制刺激肾神经传入纤维引起的升压反应。这些结果表明,室旁核和中枢的,尤其在室旁核的α_1肾上腺素受体在刺激肾神经传入纤维引起的升压反应中起重要作用。     

苯胺嘧啶衍生物X-9通过下调整合素β1表达抑制肝细胞癌迁移侵袭

整合素在许多肿瘤细胞中高表达,并且参与肿瘤细胞的侵袭转移。在肝细胞癌中,整合素β1被报导高表达,并促进肿瘤细胞的侵袭。目前,对于整合素的表达调控癌细胞机制以及干预其表达进而抑制肿瘤细胞转移的研究较少。本研究探讨利用小分子化合物抑制整合素表达来抑制肿瘤细胞迁移和侵袭的可能。首先,对临床肝癌细胞患者癌组织和癌旁组织中的整合素β1的表达进行检测,发现其在癌组织中的表达显著高于癌旁组织（P<0.05）。对TCGA肿瘤数据库的生物信息学分析结果同样显示,整合素β1的高表达与肝癌的分期（P=0.019）和预后（P=0.013）相关。通过筛选发现,苯胺嘧啶衍生物X09可以抑制肝癌细胞中整合素β1的mRNA和蛋白质的表达（P<0.01）。细胞划痕愈合实验和细胞穿孔实验结果显示,苯胺嘧啶衍生物X-9能够抑制肝癌细胞的迁移和侵袭（P<0.01）。进一步的研究证实,在肝癌细胞中外源表达整合素β1可以逆转X-9对肝癌细胞迁移和侵袭的抑制;而在敲低整合素β1的细胞中,X-9对细胞的迁移和侵袭的抑制被消除。因此,鉴定出苯胺嘧啶衍生物X-9可以通过下调整合素β1表达,进而抑制肝癌细胞的迁移和侵袭。     

Differentiation of Extracutaneous Melanocytes in Embryos of the Turtle,Trionyx sinensis japonicus

The present study investigates the mode of differentiation of neural crest-derived melanocytes in the embryos of the soft-shell turtle, Trionyx sinensis japonicus. DOPA reaction-positive melanoblasts were first detected in 10-day-old embryos. Melanocyte differentiation in terms of pigmentation takes place from the day 16 of development. Melanin pigments were found in the dorsal integument as well as in various extracutaneous tissues such as skeletal muscle, dorsal aorta, peritoneum, blood vessels, choroid, lung, bone marrow, fat tissues and in the connective tissue of the nose. These results suggest the presence of a specific environmental regulation of the melanoblast differentiation in the soft-shell turtle.     

兔下丘脑室旁核刺激引起的肾交感神经传出活动的抑制

本实验用家兔,氯醛糖及尿酯混合静脉麻醉,制动,人工呼吸,颈部分离出三对神经——迷走、窦及主动脉神经,以备实验中切断。记录股动脉压、肾交感神经传出性放电活动(RSED)及其频率幅度直方图。借助脑立体定向仪刺激下丘脑室旁核,当刺激较强时,在交感神经放电短暂增加之后,可引起血压升高及RSED抑制。这一抑制过程可分为两个时相:血压不变期间的初期抑制时相及与血压升高同时并存的后期抑制时相。实验发现RSED总抑制时程及后期抑制时程均与血压变动具有正相关关系,而初期抑制时程与血压变动无相关关系。切断压力感受性神经前后,虽初期抑制时程的均值无显著差异,但在切断压力感受性神经后,总抑制时程及后期抑制时程的均值大大缩短。当用较弱刺激施于室旁核时,可不引起血压变化,但仍能引起RSED抑制。这个抑制亦可因切断压力感受神经而显著缩短。上述实验结果表明:(1) 在中枢内存在着一个室旁核-肾交感传出系统的抑制机制;(2) 初期抑制来源于中枢性抑制机制,而后期抑制时相主要来源于压力感受性反射,但亦有中枢抑制机制的参与;(3) RSED的中枢抑制可能并不是兴奋后压抑,而是自室旁核至脊髓交感节前神经元的主动性抑制。     

Turtle Lung Cells Produce a Melanization-Stimulating Activity That Promotes Melanocytic Differentiation of Avian Neural Crest Cells

We found previously that neural crest cells in turtle embryos migrated into the lung buds and melanocytes were located in the lungs. The finding suggested to us that the lungs provide a stimulatory factor(s) to the differentiation of neural crest cells into melanocytes. We have established lung cell lines to facilitate analysis of the interactions of neural crest cells with the environment in melanocyte development. One cell line, TLC-2, was found to produce a putative melanization-stimulating activity (MSA), which promoted the melanocyte differentiation in vitro of avian neural crest cells. The TLC-2-derived MSA was different from that of basic fibroblast growth factor (bFGF), α-melanocyte stimulating hormone (α-MSH), and steel factor (SLF). Its molecular weight was estimated to be within the range of 150 kD. Our findings suggest that MSA may be a novel factor exercising a positive control over melanocyte differentiation.     

大鼠中枢神经系统衰老的形态学研究—黑质突触岛的年龄性变化

对２．５、１２和２９个月雄性Ｓｐｒａｑｕｅ－Ｄａｗｌｅｙ大鼠黑质网状部突触岛的年龄性变化进行形态学和形态计量学研究,结果表明：随增龄,突触岛内终末数目明显减少,与幼年组比较,中年组减少２２％（Ｐ＜０．０５）,老年组减少３９％（Ｐ＜０．０５）,同时,终末及树突内出现一系列形态学改变,胶质鞘直接覆盖树突的面积也明显增加。     

来源于嗜热氢化杆菌的新型对苯二甲酸双(羟乙)酯水解酶的表达纯化与酶学性质

石化来源的聚对苯二甲酸乙二酯(polyethylene terephthalate,PET)被广泛用于矿泉水瓶、食品包装和纺织品等领域,因其在自然界中不易分解,大量使用后的PET废弃物造成了严重的环境污染与资源浪费。使用生物酶法对PET废弃物进行解聚,并对解聚产物进行升级循环利用是进行塑料污染治理的重要方向之一,其中关键的是PET水解酶的解聚效率。对苯二甲酸双(羟乙基)酯(bis(hydroxyethyl)terephthalate,BHET)是PET生物酶解的中间产物,其累积是限制PET水解酶催化效率的一个重要因素,BHET水解酶和PET水解酶的联用能提升PET的整体水解效率。来源于嗜热氢化杆菌(Hydrogenobacter thermophilus)的双烯内酯酶(HtBHETase)对BHET有显著水解效果,将该酶在大肠杆菌(Escherichia coli)中进行重组表达并纯化后,对其酶学性质进行了研究。结果显示,HtBHETase对短碳链的酯类如对硝基苯酚乙酸酯催化活性较高,HtBHETase以BHET为底物时的最适反应pH值和最适反应温度分别为5.0和55℃;该酶有较好的热稳定性,经80℃的条件处理1 h仍能保持80%以上活性,显示出了良好的热稳定性,HtBHETase有在PET塑料生物解聚中使用的潜力,本研究为推动生物酶法降解PET提供了新的参考。     

贵州核桃种质资源表型性状多样性研究

该研究以贵州省内的3个山脉(乌蒙山、苗岭山和武陵山)、19个核桃和泡核桃实生居群、245棵实生单株为研究材料,对坚果表型性状29个指标的多样性、相关性、聚类及变异进行分析,以揭示贵州核桃资源的表型遗传多样性水平,为贵州核桃资源的保存与利用及核心种质构建提供依据。结果显示：(1)核桃和泡核桃实生居群245份种质资源的18个表型质量性状Simpson指数为0.26～0.82,Shannon-Wiener指数为0.12～1.79;核桃小叶形状多样,易发生顶叶退化,坚果核壳表面特征、坚果形状及核仁皮色多样性丰富。(2)坚果表型变异系数为3.32%～47.67%,平均为21.28%且差异显著(P<0.05),居群间变异系数为9.42%～31.61%且差异显著(P<0.05);居群内和居群间变异均是核桃表型多样性的来源,但坚果性状在居群间差异显著性均高于居群内,说明居群间变异是该区域坚果表型变异的主要来源。(3)3个山脉区域核桃表型均有不同程度变异,其中,苗岭山核桃表型变异程度低,乌蒙山核桃表型变异程度高;UPGMA聚类结果显示,19个核桃实生居群依据贵州山脉区域划分为三类,表明贵州核...     

Cambrian lobopodians–ancestors of extant onychophorans?

This paper is a review of published information on fossil lobopodians, with addition of observations and ideas based on new material. It is also an analysis of the phytogeny of the group, and presents a new classification. A character shared by three or four families, yet not seen before, is a pair of enlarged sclerites covering the head. This forms an argument for re-orienting Hallucigenia once again. This genus no longer being enigmatic, a corner-stone in Stephen Jay Gould's evidence for extinct phyla is therefore gone. It is suggested that the lobopodians, phylum Lobopodia, are arranged in two classes, the extinct Xenusia for marine forms, and the Onychophora for terrestrial forms. The marine lobopodians are morphologically much more diverse than the extant onychophorans, a condition expressed in the classification. New taxa are: Hallucigenia fortis sp. nov., the families Luolishaniidae, Cardiodictyidae and Onychodictyidae, and the new orders Archonychophora, Scleronychophora and Paronychophora.     

激活淋巴细胞cDNA单链库的构建

介绍一种激活淋巴细胞cDNA单链库构建方法,此库具有良好的模板活性. 用PCR法从此库中克隆了多种中国人源性的细胞因子.