Efficacy of Ginkgo biloba on Vaginal Estrous and Ovarian Histological Alterations for Evaluating Anti‐Implantation and Abortifacient Potentials in Albino Female Mice

Ginkgo extract, EGb 761 is known as a vasoregulatory variable for the conventional reproduction therapy. EGb 761 was orally administered in 0 (control), 3.7, 7.4, and 14.8 mg/kg bw/day for 28 days (thereafter mated with normal fertile male), from day 1 to day 7 of pregnancy or from the 10th to 18th day of pregnancy, respectively. Vaginal smears were performed daily. On 20th day of pregnancy, the females were killed by cervical dislocation and their kidneys, liver, brain, placenta, spleen and ovaries were removed and weighed. The ovaries were prepared for histological examinations, and then ovarian follicles were counted. Maternal toxicity, estrous cycle, reproductive hormones, ovarian follicle counts, resorption index, implantation index, fetal viability and fetuses, and placenta mean weights were evaluated. There was a dose‐dependent ovarian toxic effect of EGb 761. Ovarian follicle counts, resorption index, implantation index, fetal viability were significantly reduced in 14.8 mg/kg bw/day dose. Treatment with 14.8 mg/kg bw/day EGb 761 induced disruption of estrous cycle and caused maternal toxicity, in addition to fetal toxicity. Therefore, the data obtained indicate that Ginkgo biloba extract at 14.8 mg/kg bw/day dose level exhibit toxic effect on reproductive cyclicity and could have anti‐implantation and abotifacient properties in female mice.     

产L-乳酸米根霉PW352特性及低能离子注入诱变高产菌株研究

为了获得更适于工业生产的产乳酸菌株,以葡萄糖为碳源对PW352菌株特性进行了研究,并在此基础上采用离子束诱变方法,对米根霉PW352进行改良,获得高产L( )—乳酸菌株RE3303,产酸能力达131～136g／L,最高可达140g／L,糖转化率为86％～90％,产酸比PW352提高75％。     

Tight junction protein ZO-2 expression and relative function of ZO-1 and ZO-2 during mouse blastocyst formation

Apicolateral tight junctions (TJs) between epithelial cells are multiprotein complexes regulating membrane polarity and paracellular transport and also contribute to signalling pathways affecting cell proliferation and gene expression. ZO-2 and other ZO family members form a sub-membranous scaffold for binding TJ constituents. We investigated ZO-2 contribution to TJ biogenesis and function during trophectoderm epithelium differentiation in mouse preimplantation embryos. Our data indicate that ZO-2 is expressed from maternal and embryonic genomes with maternal ZO-2 protein associated with nuclei in zygotes and particularly early cleavage stages. Embryonic ZO-2 assembled at outer blastomere apicolateral junctional sites from the late 16-cell stage. Junctional ZO-2 first co-localised with E-cadherin in a transient complex comprising adherens junction and TJ constituents before segregating to TJs after their separation from the blastocyst stage (32-cell onwards). ZO-2 siRNA microinjection into zygotes or 2-cell embryos resulted in specific knockdown of ZO-2 mRNA and protein within blastocysts. Embryos lacking ZO-2 protein at trophectoderm TJs exhibited delayed blastocoel cavity formation but underwent normal cell proliferation and outgrowth morphogenesis. Quantitative analysis of trophectoderm TJs in ZO-2-deficient embryos revealed increased assembly of ZO-1 but not occludin, indicating ZO protein redundancy as a compensatory mechanism contributing to the mild phenotype observed. In contrast, ZO-1 knockdown, or combined ZO-1 and ZO-2 knockdown, generated a more severe inhibition of blastocoel formation indicating distinct roles for ZO proteins in blastocyst morphogenesis.     

转基因受体酵母菌的低能氩离子注入研究

通过不同剂量的低能Ar 注入酿酒酵母Ke-y,筛选出了一种较好的菌体保护液,获得了一系列Ar 注入参数。在该研究体系内,Ar 最佳注入剂量分别为9 0×1015 ions/cm2 或13 5×1015 ions/cm2(适于IBB Device 1 型离子注入机)和1 0×1016ions/cm2 或1 4×1016 ions/cm2(适于LZD1000型离子注入机),为离子束介导外源基因组DNA在酵母菌Ke-y中的遗传转化奠定了基础。     

离子注入选育高产木聚糖酶黑曲霉及其发酵条件研究

以黑曲霉A3为出发菌,利用离子注入技术选育出一株遗传性状稳定的木聚糖酶高产突变株AN497,其产酶水平较出发菌从野生型A3菌株的405.6IU/ml提高到586.2IU/ml,即酶产量增加了44.5%;对高产菌进行发酵条件优化,发现以玉米芯粉为主要碳源、用蔗糖代替葡萄糖作为附加碳源,对木聚糖酶的发酵具有明显的促进作用;采用复合的无机氮源 (NH4)2SO4和NaNO3,(1: 2)浓度以10g/L为宜;菌株对发酵通氧量具有较高的要求,摇瓶转速在230r/min时的产酶水平较200r/min要高;通过发酵条件的优化,高产菌株的产酶活力最高可达671.1IU/mL,比出发菌株的产酶量提高了65.5%。     

Tight junction biogenesis during early development

The tight junction (TJ) is an essential component of the differentiated epithelial cell required for polarised transport and intercellular integrity and signalling. Whilst much can be learnt about how the TJ is constructed and maintained and how it functions using a wide range of cellular systems, the mechanisms of TJ biogenesis within developmental models must be studied to gain insight into this process as an integral part of epithelial differentiation. Here, we review TJ biogenesis in the early mammalian embryo, mainly considering the mouse but also including the human and other species, and, briefly, within the amphibian embryo. We relate TJ biogenesis to inherent mechanisms of cell differentiation and biosynthesis occurring during cleavage of the egg and the formation of the first epithelium. We also evaluate a wide range of exogenous cues, including cell-cell interactions, protein kinase C signalling, gap junctional communication, Na⁺/K⁺-ATPase and cellular energy status, that may contribute to TJ biogenesis in the embryo and how these may shape the pattern of early morphogenesis.     

离子束注入对衣康酸生产菌种的改良

用10keV、剂量5.2×10~(14)～5.2×10~(15)ions/cm~2的氮离子注入衣康酸生产菌株土曲霉A9003,在2％LiCl抗性平板筛选到一株能在39℃发酵的衣康酸高产菌株。该菌株在30L发酵罐发酵产酸7.5％,转化率60.1％,发酵周期50h。     

玻璃化法对离子注入拟南芥幼苗过程中的冻害防护效应

离子注入过程中活体材料往往由于真空造成的冻害而不能存活.文章以拟南芥幼苗为对象,尝试了玻璃化法对注入过程中冻害的防护效应.结果显示,玻璃化处理的2 d龄幼苗经液氮冻融处理后存活率最高,达80%以上.2 d龄幼苗经玻璃化处理后进行离子注入,在一定剂量范围内成活率在90%以上;而未经玻璃化处理的幼苗离子注入后均不能成活.玻璃化后注入的幼苗成活率随注入剂量的增加而呈下降趋势,但受注入的离子能量的影响不大.显示玻璃化法对离子注入过程中活体材料遭受的冻害有较好的防护效果,在应用上有一定的意义.     

低能铁离子束对原卟啉IX二钠盐的辐照效应研究

110ke V Fe^ 离子注入原卟啉IX二钠盐薄膜亲品后的一些谱学分析结果表明,低能铁离子束辐照可以导致生物分子的损伤和化学改性,并且初步证实注入铁离子在样品分子中慢化沉积后形成含铁的金属络合物,即注入铁离子的质量沉积。     

低能铁离子束辐照氨基酸衍生物的红外光谱结构表征

利用傅里叶变换红外光谱（FTIR）技术研究了能量为110keV的Fe^ 离子束辐照L（ ）-半胱氨酸盐酸盐单晶水合物固态样品的结构变化情况。对辐照样品的两次红外光谱分析结果有所不同,表明固态样品不同部位受低能铁离子束作用后可发生不同的分子改性;但二者又具有一定的相似性,都反映了原分子中氨基、羧基和巯基等基团的受损及硝基和酰胺基团等的生成。