染色体研究的进展与植物分类学(下)

染色体研究的进展与植物分类学（下）徐炳声,张芝玉,陈家宽,洪德元（中国科学院植物研究所系统与进化植物学开放研究实验室北京１０００９３）（上海第二军医大学药学院上海２００４３３）（武汉大学生命科学学院武汉４３００７２）ＡＤＶＡＮＣＥＳＩＮＣＨＲＯＭＯＳ...     

以人工合成多肽为抗原的戊型肝炎病毒抗体检测方法的建立和评价

酶联法是ＨＥＶ感染的主要检测方法,多采用基因表达产物为抗原。近来由于人工合成多肽抗原克服了基因重组抗原制备复杂、非特异结构多、难以纯化的缺点,已广泛用于多种病毒感染的检测。根据已发表的ＨＥＶ氨基酸序列的保守性及亲水性等特点,设计合成了两个多肽ＥＳＰ１和ＥＳＰ２,分别位于ＯＲＦ２和ＯＲＦ３区,以此为混合抗原建立了检测ＨＥＶ抗体的间接ＥＬＬＳＡ法,与市售优质试剂比较,其阳性符合率为９７．７５％,阴性符合率为９９．４３％,总符合率为９８．８６％。该方法灵敏度高、特异性强、安全快速,是检测ＨＥＶ感染和流行病学调查的理想方法。     

结直肠癌P53蛋白定量分析及其与肿瘤生物学行为的关系

应用MD-20显微图象分析仪对30例结直肠癌的P53蛋白免疫组织化学反应产物进行定量测定,以观察P53蛋白相对含量与肿瘤生物学行为的关系.结果显示:结直肠癌P53蛋白MOD值与PCNA增殖指数呈正相关(P<0.05).P53蛋白MOD值大的肿瘤多里浸润性生长方式,且浸润至浆膜外者多(PM<0.01,P<0.05).淋巴结转移与MOD值无明显关系(P>0.05).结果提示:结直肠癌P53蛋白相对含量对肿瘤的生物学行为有重要影响.     

水稻叶片对模拟酸雨伤害的生理反应

水稻暴露于ｐＨ２．５～４．２的模拟酸雨中２个月后测定表明：叶片叶绿素含量下降,细胞液离子外渗率增加,气孔阻抗增高,蒸腾速率降低。不同叶位的水稻叶片对模拟酸雨的敏感性不同,杂交稻（汕优６３）对模拟酸雨的敏感性较粳稻（中粳８６４）高     

油麻藤凝集素的荧光光谱研究

用化学修饰、内源荧光和荧光淬灭等方法研究了油麻藤凝集素（ＭＳＬ）的溶液构象变化和微环境的构象特征。研究发现ＭＳＬ分子中总共有９个色氨酸（Ｔｒｐ）残基,它们的荧光能被丙烯酰胺淬灭,但不易为ＫＩ接近而淬灭,ＭＳＬ经Ｎ－溴代琥珀酰亚胺（ＮＢＳ）修饰后,其内源性荧光发射谱发生相应变化,结果表明ＭＳＬ分子中部分Ｔｒｐ残基埋藏于分子内部,而位于分子表面的Ｔｒｐ残基可能处于分子的疏水袋中。     

水稻巯基蛋白酶抑制剂的分子修饰与其对稻瘟病菌的抑制作用

水稻巯基蛋白酶抑制剂（ＣＰＩ）经用二硫苏糖醇,对氯汞苯甲酸和碘乙酸修饰后,对木瓜蛋白酶的抑制活性并无改变;用Ｎ－乙基顺丁烯二酰亚胺与ＣＰＩ反应,可以测出ＣＰＩ分子内有１９个巯基被修饰,被修饰后,抑制活性仍无改变,表明水稻ＣＰＩ的抑制活性不需要巯基参与;应用Ｎ－溴代丁二酰亚胺与ＣＰＩ反应,可测出ＣＰＩ分子内有２个Ｔｒｐ被修饰,修饰后,抑制活性全部丧失,表明Ｔｒｐ是保持抑制活性所必需的基团。水稻巯基蛋白酶抑制剂和丝氨酸蛋白酶抑制剂对稻瘟病菌丝体的生长均有抑制作用,但后者的抑制作用比前者更强,若将两种抑制剂混合使用,则对稻瘟病菌丝体的抑制作用非常强烈;当抑制剂加入量达７２μｇ时,即可产生明显的抑制作用。     

黄精凝集素Ⅱ分子稳定性与生物学活性研究

黄精凝集素Ⅱ分子稳定性与生物学活性研究鲍锦库,曾仲奎,周红（四川大学生物系,成都,６１００６４）本文在黄精凝集素Ⅱ纯化及性质研究的基础上,应用多种变性条件,研究其分子特性,同时对分子的巯基和色氨酸进行修饰,研究该凝集素分子保持其生物学活性与这些基团的...     

Use of moving aeration membrane bioreactor for the efficient production of tissue type plasminogen activator in serum free medium

A moving aeration-membrane (MAM) bioreactor was employed for the production of 2 μg/mL of tissue type Plasminogen Activator (tPA) in serum free medium from normal human fibroblast cells. This system could maintain high cell density for long periods of steady state conditions in perfusion cultivation. Under normal operating conditions, shear stress was as low as 0.65 dynes/cm² at the agitation speed of 80 rpm. Even though cell density gradually decreased with increasing agitation speed, tPA production increased linearly with increasing shear stress within a moderate range. This culture system allowed production of 2 μg tPA/mL while maintaining a high cell density of 1.0×10⁷ viable cells/mL.     

A NEW SPECIES OF GENUS HABROPHLEBIODES ULMER (EPHEMEROPTERA: LEPTOPHLEBIIDAE)

Abstract  The present paper deals with a new species Habrophlebiodes zijinensis sp. nov. collected in Nanjing, Jiangsu Povince, China.     

SEXUAL DIFFERENTIATION OF GRIFFITHSIA (CERAMIALES, RHODOPHYTA): NUCLEAR PLOIDY LEVEL OF MIXED-PHASE PLANTS IN G. JAPONICA1

Mixed-phase plants of Griffithsia japonica Okamura spontaneously occurred in a laboratory culture. Four female plants produced tetrasporangia and spermatangia in addition to their normal female reproductive structures (bisexual/mixed-phase plants), and four male plants produced tetrasporangia as well as spermatangia (male/mixed-phase plants). To determine the nuclear ploidy level of these mixed-phase plants, relative nuclear sizes of male, female, tetrasporangial, and mixed-phase plants were measured using a microscopic image analysis system. Haploid gametophytes could be distinguished from diploid tetrasporophytes by relative nuclear sizes, with the later having nuclei twice the size of the former. Relative nuclear sizes of the mixed-phase plants were similar to those of the haploid plants. Thus, the mixed-phase plants were determined to be haploid. Haploid mixed-phase plants of G. japonica have a potential to produce male, female and tetrasporangial reproductive structures. Sex determination models are discussed to explain "haploid" mixed-phase phenomena in red algae .