笼养白头叶猴夏季水分摄入与消耗的初步研究

叶片中的水分含量是白头叶猴水分的主要来源,占水分需求总量的８３．６８％,其它的１６．３２％来自于自由水。在笼养条件下,白头叶猴可饮用自来水,野生状态下,动物饮用露水或雨水。尽管饮水行为不是每天都有,但能经常观察到,特别是在夏季雨后．除了体表和呼吸系统的水分蒸发外,白头叶猴通过尿和粪便丢失的水分含量分别是４４．６８％和５５．３２％。     

在小鼠胚胎干细胞进行基因打靶的策略

基因打靶技术是一种通过同源重组按预期方式改变生物活体的遗传信息的实验手段,与小鼠胚胎干细胞培养系统相结合,使得人们可以方便地将各种突变引入小鼠体内,得以从生物整体水平上研究高等真核生物基因的表达、调控及其生理功能.扼要介绍了近年来在小鼠胚胎干细胞进行基因打靶的研究进展.     

五个氨基酸磷光性质的研究

研究了5个氨基酸的磷光特性、光谱、寿命和最小检测量.以色氨酸(Trp)的磷光最强,在λ_ex/λ_em=290/438 nm,最小检测量为1 ng,酪氨酸(Tyr)其次(284/390 nm)为Trp的1/10,苯丙氨酸(Phe)在276/386 nm,脯氨酸(Pro)在308/454 nm,组氨酸(His)在320/466 nm,其磷光只有Trp的1%.Phe与Trp磷光寿命最长,在7 s左右;His最短,只有0.49 s;Tyr 2.8 s,Pro 1.34 s.另外研究氨基酸在甲醇,乙醇,丙醇,丁醇中及pH对氨基酸磷光性质的影响.还计算了Stokes位移能量及激化态pK^*_a值.     

博莱霉素-Ce(Ⅲ)对DNA的切断机理初探

根据外切核酸酶Ⅲ酶解博莱霉素-Ce(Ⅲ)［BLMA5-Ce(Ⅲ)］作用过的双链直线型DNA时, 酶解速率明显增大, 酶解产物除5′-dAMP、5′-dGMP、5′-dCMP和5′-dTMP 4种单核苷酸外, 还有其他成分存在的实验事实, 推测出BLMA5-Ce(Ⅲ)在DNA双链的特定部位沿5′→3′的方向切断磷酸二酯键, 使DNA的双链上形成多个暴露的3′-OH末端.     

Construction of a recombinant human GM-CSF/MCAF fusion protein and study on its in vitro and in vivo antitumor effects

A novel cytokine fusion protein was constructed by fusing granulocyte macrophage colony stimulat-ing factor (GM-CSF) with monocyte chemotactic activating factor (MCAF), which acts as a factor directing effector cells (monocytes) to a target site. The recombinant human GM-CSF/MCAF fusion protein could sustain the growth of GM-CSF-dependent cell line TF1 and was chemotactic for monocytes. The in vitro antitumor effect showed that rhGM-CSF/MCAF could activate monocytes to inhibit the growth of several human tumor cell lines, including a promyelocyte leukemia cell line HL-60, a lung adenocarcinoma cell line A549, a hepatoma cell line SMMC-7721 and a melanoma cell line Bowes. Furthermore, the cytotoxicity of monocytes activated by rhGM-CSF/MCAF against HL-60 and A549 was greater than that activated by GM-CSF or MCAF alone, even greater than that activated by a combina-tion of GM-CSF and MCAF, suggesting that the fusion protein has synergistic or enhanced effects. The in vivo anti-tumor effect indicated that     

Construction of a trivalent candidate Shigella vaccine strain with host-vector balanced-lethal system

A trivalent liveShigella vaccine candidate FSD01 against S.flexneri 2a, S.sonnei and S.dysenteriae I was constructed. This candidate strain was based on the S.flexneri 2a vaccine T32. By homologous recombination exchange, the chromosomalasd gene of T32 was site-specifically inactivated, resulting in the strain unable to grow normally in LB broth, while anotherasd gene of S.mutans was employed to construct an Asd⁺ complementary vector. This combination ofasd ^- host/Asd⁺ vector formed a balanced-lethal expression system in T32 strain. By use of this system, two important protective antigen genes coding for S.sonnei Form I antigen and Shiga toxin B subunit were cloned and expressed in T32, which led to the construction of trivalent candidate vaccine FSD01. Experimental results showed that this strain was genetically stable, but its recombinant plasmid was non-resistant. Moreover, it was able to effectively express trivalent antigens in one host and induce protective responses in mice against the challenges of the above threeShigella strains.     

母兔配种后10小时血清中若干生理指标与子代性比的相关

测定日本大耳白兔母兔配种后１０小时血清中的１０项生理指标,并与母兔所产每窝仔兔的性比（雄性个体所占比率）进行对应分析（窝仔数＜６的数据未参与此项分析）。结果表明：母兔血清中ＦＳＨ、Ｔ（睾酮）、 Ｎａ＋和Ｍ２＋的浓度在高、低两个性比组间有显著差异, Ｔ３（三碘甲状腺原氨酸）的差异接近显著水平（Ｐ＜０．１）;并且,ＦＳＨ和Ｔ３与子代性比里显著负相关（ｒ分别为－０．５０和－０．４６）,Ｍｇ２＋与子代性比里显著正相关（ｒ＝０．３９）;同时,Ｍｇ２＋／Ｃａ２＋、Ｍｇ２＋×Ｎａ＋、Ｍｇ２＋×Ｋ＋和Ｔ３×ＦＳＨ与子代性比的相关分别为０．４０、０．４３、０．３９和－０．５３（Ｐ＜０．０５）。     

神经生长因子家族及其受体研究进展

过去几年在神经营养因子、受体和神经元细胞程序性死亡的研究领域中取得了几项引人注目的进展：（１）神经生长因子（ＮＧＦ）基因家族的其他一些成员包括脑源性神经营养因子（ＢＤＮＦ）、神经营养素－３（ＮＴ－３）、神经营养素－４（ＮＴ－４）、神经营养素－５（ＮＴ－５）的发现;（２）神经生长因子三维结构及功能和进化之关系的阐明;（３）定性了两种神经生长因子受体Ｐ７５＾ＮＧＦＲ和原癌基因ｐ１４０＾ｔｒｋＡ以及相关     

榆绿毛萤叶甲寄生微粒子虫新种记述：微孢子门：微粒子科

本文记述寄生于榆绿毛萤叶甲的一种微粒子虫新种的光匀和电镜形态特征及寄生习性。并讨论了新种鉴别特性。     

东海黑潮锋面涡旋区浮游动物的分布

本文根据中日黑潮合作调查研究,１９８９年４月航次在东海北部黑潮及其邻近海域采集的浮游生物样品,分析黑潮锋面涡旋区饵料浮游动物的分布特点及其与海洋环境的关系。首次报道了在东海黑潮锋面涡的冷中心区发现冷水性桡足类,从而丰富了调查区浮游动物区系的冷水种成分,并为锋面涡涌升水的研究和黑潮潜流的研究提供了生物学证据。