黄瓜幼苗的冷锻炼与低温引起的光抑制

黄瓜幼苗的冷锻炼与低温引起的光抑制李晓萍,陈贻竹,李平,郭俊彦（中国科学院华南植物研究所,广州５１０６５０）关键词：低温引起的光抑制,荧光猝灭,冷锻炼,黄瓜幼苗低温使植物利用光能的能力降低从而引起或加剧光抑制（ｈａｓ等１９８３）。在光抑制中常以叶绿素...     

一例智力低下患者7q~ 标记染色体的来源鉴定

以人类染色体显微切割、PCR技术构建的现有人类染色体特异性和染色体区带特异性探针池作为绘画探针,采用正向染色体绘画技术,结合染色体筛查方法,查明了一例7q~ 标记染色体患者的染色体附加片段来源于3q26→3qter。确定该患者的核型为46,XX,-7, der(7)t(7;3)(7pter→7q32::3q26→3qter)。应用这个策略,能够快速有效地鉴定标记染色体的来源。     

Insect-resistant transgenic cabbage plants and their progenies

An insecticidal crystal protein gene of Bacillus thuringiensis was transferred into cabbage genome with the method of Agrobacterium infection. Cotyledons with petioles as explants were cocultivated with Agrobacterial suspension. Calli generated at the basis of petiole were subjected to selection on the MS medium containing 15-30 mg/L kanamycin (Km). About 5% explants produced calli growing continuously on the selective medium. Green shoots appeared on these calli when they were transplanted onto medium with Km and 6-BA for plant differentiation. The shoots were separated and cultivated on medium with kanamycin. About 80% shoots were rooted. Non-transformed control calli could not give normal shoots and roots and brownized and died gradually. Larvae of Pieris rapae showed poisonous symptoms: growth inhibition and mortality when fed with the leaf of the transgenic plants. About 80% of regenerated plants showed positive hybridization bands when their DNA were probed with crystal protein sequence of Bacillu     

Investigations of peptide hydration using NMR and molecular dynamics simulations: A study of effects of water on the conformation and dynamics of antamanide

Summary The influence of water binding on the conformational dynamics of the cyclic decapeptide antamanide dissolved in the model lipophilic environment chloroform is investigated by NMR relaxation measurements. The water-peptide complex has a lifetime of 35 s at 250 K, which is longer than typical lifetimes of water-peptide complexes reported in aqueous solution. In addition, there is a rapid intracomplex mobility that probably involves librational motions of the bound water or water molecules hopping between different binding sites. Water binding restricts the flexibility of antamanide. The experimental findings are compared with GROMOS molecular dynamics simulations of antamanide with up to eight bound water molecules. Within the simulation time of 600 ps, no water molecule leaves the complex. Additionally, the simulations show a reduced flexibility for the complex in comparison with uncomplexed antamanide. Thus, there is a qualitative agreement between the experimental NMR results and the computer simulations.     

中国铜脚异丽金龟组及其分类问题讨论(鞘翅目:丽金龟科)(英)

新设的铜脚异丽金龟组包括中国异丽金龟属已知的大型、绿色种类,绝大多数为常见种,彼此形态十分近似。它们是:铜脚异丽金龟(新纪录)Anomala cupripes Hope new record,红脚异丽金龟(新种)A. rubripes sp. nov., 绿脚异丽金龟(新亚种)A. rubripes virescens ssp. nov., 彤脚异丽金龟(新种)A. ignipes sp. nov., 川直异丽金龟A. truncata Bates,滇直异丽金龟(新等级)A. truncata chlorochelys Arrow, stat, nov., 宽角异丽金龟A. expansa Bates,大绿异丽金龟(新种)A. virens sp. nov., 砂尾异丽金龟(新种)A. granuliformis sp. nov. 和檐角异丽金龟(新种)A. planicorna sp. nov.。其中红脚异丽金龟和绿脚异丽金龟是我国南部和台湾的重要害虫,国内外文献中长期误作铜脚异丽金龟引用至今。     

人类疱疹病毒6型可诱生TNF－α

用生物活性法和双抗体夹心桥联酶免疫吸附（ＥＬＩＳＡ）法检测了人类疱疹病素６型（ＨＨＶ－６）ＧＳ株和南京地方株ＣＮ５,８,１０感染的淋巴细胞培养上清中的肿瘤坏死因子（ＴＮＦ）的水平,发现培养２４ｈ即可检出高水平的ＴＮＦ,４８～７２ｈ述到峰值,此后逐渐下降,与未感染耐照组比较有及其显著的差异（Ｐ＜０．００１）。ＧＳ株与地方株同诱生ＴＮＦ水平无儿著性差异（Ｐ＞０．１）,三株地方株诱生ＴＮＦ也无显著性差异（Ｐ＞０．０５）。ＴＮＦ－α单抗可以完全中和培养上清中ＴＮＦ的活性,证实上清中有ＴＮＦ－α。与ＬＰＳ比较,ＨＨＶ－６诱生ＴＮＦ－α的能力要强得多。     

猪肝刺激物质pHSS对离体肝细胞DNA合成的影响

应用[~3H]TdR掺入离体培养大鼠肝细胞DNA的方法,测定由本室提取的pHSS的生物活性。结果表明,pHSS可显著促进原代培养大鼠肝细胞的DNA合成,其促进率约为对照组的10倍左右。培养液中血清浓度对pHSS的生物活性表达有显著影响,不同浓度血清可以使pHSS表现出不同的量效关系,这些结果在Buffello大鼠肝细胞系的实验中得到进一步证实。在低剂量pHSS的刺激下,不同年龄大鼠肝细胞的[~3H]TdR掺入率无显著差异。但高剂量时,pHSS对幼鼠作用不明显。     

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     

慢性心功能不全大鼠心脏和血淋巴细胞β-肾上腺素受体的改变

在主动脉与肾动脉缩窄造成的慢性心功能不全大鼠,血浆儿茶酚胺浓度增高;心脏β-肾上腺素受体(β-AR)数量增加,其中β_1-AR及其mRNA增加,而β_2-AR及其mRNA不变;左心房异丙基肾上腺素(ISO)浓度-收缩效应曲线右移;而心肌ISO浓度-cAMP蓄积曲线无显著改变;血淋巴细胞β-AR数量显著减少.结果提示心功能不全时心脏β_1-AR数量增多,但其介导的正性变力效应反而降低,在cAMP生成以后的信号转导过程或心肌收缩成分功能存在障碍,而血淋巴细胞β-AR的改变与心脏β-AR的功能改变平行.     

硬脂酸修饰超氧化物歧化酶的制备及其性质研究

报道了一种修饰ＳＯＤ的方法。所得硬脂酸修饰ＳＯＤ比活力为每毫克蛋白１００００单位,经鉴定已达均一程度。测得其分子量为３５０００．修饰ＳＯＤ和天然ＳＯＤ在紫外光区的最大吸收均在２６５ｎｍ。修饰ＳＯＤ对温度、ｐＨ、蛋白酶水解的稳定性比天然ＳＯＤ增强,且免疫原性消除。在低浓度的某些有机介质中活性比在水中高。