湖北省潜水蜂一新种（膜翅目：潜水蜂科）

潜水蜂属Agriotypus Curtis全世界共报道8种,其中我国已知4种。本文新添一采自湖北省房县的新种:郑氏潜水蜂A.zhengi sp.nov。     

水分胁迫导致小麦叶片光合作用下降的非气孔因素

小麦幼苗根部在不同渗透势溶液(PEG4000)中经受不同时间胁迫,叶片的RWC和水势下降、膜的RP、R_s和C_i升高。同时P_n下降。它还使叶肉细胞内的叶绿体排列发生紊乱、膜受到破坏、基粒间的连接松驰或消失、类囊体片层肿胀和解体、脂质小球增多和淀粉粒消失。相应地叶片的RuBPC活性下降和GO活性升高,从而促进了C_i的累积。此外MDA含量增多是自由基诱发脂质过氧化的结果。这些非气孔因素可能是造成小麦光合作用下降的重要原因。     

Vergleichende Karyologie der Gräser-SubtribenAristaveninae undAirinae (Poaceae — Aveneae)

The chromosome numbers of nearly all species of the grass subtribesAristaveninae andAirinae from Europe and northern Africa are presented. Among theAristaveninae the genusAristavena has 2n = 14 chromosomes, whereasDeschampsia forms a polyploid series with the basic number x = 13. In the subtribeAirinae the basic number x = 7 predominates.Avenella includes a polyploid series up to dekaploidy, whilst the lowest diploid value so far known in grasses — caused by descending dysploidy — exists in the annual generaAiropsis andPeriballia with 2n = 8.From both subtribes 12 different karyotypes are described and depicted as idiograms. The basic karyotypes ofCorynephorus, Periballia andVahlodea differ from each other by different chromosome length. SAT-chromosomes in theAirinae vary somewhat. Some marker chromosomes eludicate phylogenetic relationships. Amphiplasty appears in various genera and was studied particularly in the amphidiploidAira caryophyllea. Karyological and genomatic trends are considered in relation to evolutionary strategies of annuals and perennials.The nuclear DNA content of some species has been determined cytophotometrically. In subtribeAirinae a positive correlation exists between chromosome volume, pollen diameter, and DNA content. A comparison of the duration of microsporogenesis and microgametogenesis in annual and perennial species with their nuclear DNA content has shown that a primary nucleotypic influence is not recognizable.

     

Immunochemical studies on the large polypeptide of electrophorus electroplax (Na+ + K+)-ATPase.

Antibodies against Lubrol-solubilized Electrophorus electroplax (Na+ + K+)-ATPase (ATP phosphohydrolase, EC 3.6.1.3) and its 96 000-dalton polypeptide (P96) were raised in rabbits. The P96 antibody does not cross react with the (Na+ + K+)-ATPase from mammalian species and tissues, but it cross reacts with the (Na+ + K+)-ATPase from both Electrophorus electroplax and brain. The combination of enzyme with anti-P96 is found to inhibit phosphoryl enzyme formation to the same extent that it inhibits enzyme activity. The rate of K+-sensitive dephosphorylation of phosphoryl enzyme appears to be unchanged. These are also found to be true with the antibody against the whole enzyme. Upon tryptic digestion of the enzyme-anti-P96 complex only the large polypeptide of the enzyme is protected. In the case of enzyme-anti-Lubrol-solubilized enzyme complex, both the large and small polypeptides are protected, whereas preimmune sera are without any protecting effect. The data indicate that the phosphoryl acceptor polypeptide and the Lubrol-solubilized electroplax (Na+ + K+)-ATPase from which the polypeptide is derived are phylogenetically distinct from those of the mammalian (Na+ + K+)-ATPases. The selective tryptic resistance of the enzyme-anti-P96 complex indicates that the two polypeptides are spatially well separated, possibly on opposite sides of the membrane.     

Cold resistance of the brain during hibernation. Temperature sensitivity of the partial reactions of the Na+, K+-ATPase.

The regulatory effect of calcium added in vitro on 25-hydroxycholecalciferol metabolism was studied in kidney mitochondria and in renal tubules from vitamin D-deficient chicks. The addition of calcium (0.05 – 0.2 mm) to mitochondrial suspensions prepared with calcium-chelating agents caused a marked and dose-related stimulation of 1-hydroxylation. A sharp decline in the activity was induced by higher concentrations of calcium (0.3 – 0.7 mm). A similar but less striking biphasic effect of calcium on 1-hydroxylation was observed in mitochondria prepared in the absence of calcium chelating agents. The effect of calcium was not a consequence of accelerated mitochondrial translocation of either exogenous NADP or Mg²⁺ but was related to mitochondrial calcium content. The addition of inhibitors of the calcium uptake, i.e., LaCl₃ or ruthenium red, or a calcium ionophore (A 23187) significantly inhibited the calcium-induced stimulation of the 1-hydroxylation reaction. Similar calcium effects were also observed in renal tubules isolated from intact, but not from parathyroidectomized, vitamin D-deficient chicks. These data strongly suggest that mitochondrial calcium plays an important role in the regulation of 1-hydroxylase activity in kidney.     

Sodium + potassium-activated ATPase of mammalian brain. Regulation of phosphatase activity.

1. The K+-nitrophenylphosphatase activity associated with mammalian brain (Na+ + K+)-ATPase displays K+ activation curves that have intermediary plateaus and maxima in the presence of less than saturating concentrations of Na+. Zero Na+ and saturating Na+ produce sigmoid K+-activation curves with low and high K+ affinities respectively. 2. ATP inhibits K+-activated nitrophenylphosphatase through both competitive and non-competitive mechanisms. ATP is synergistic with Na+ in the mechanism which converts the enzyme from low to high K+ affinity. 3. The Na+ and K+ interactions can be accounted for by equations which describe a model with separate regulatory sites for Na+ and K+ and with K+- requiring catalytic site which is only accessible in one of the two principal conformational stages of the enzyme. 4. The effects of ATP can be accounted for by the same model through interactions at a single nucleotide binding site. Inhibition which is competitive with K+ and non-competitive with substrate arises from stabilization of the inactive enzyme conformation. Inhibition which is non-competitive with K+ and competitive with substrate results from interactions with the active enzyme conformation. The synergism between Na+ and ATP appears to arise as a consequence of the formation of phosphoryl enzyme. 5. A model for (Na+ + K+)-ATPase is discussed which involves in-phase coupling of subunit interactions as suggested by these studies.     

Interactions of lectins with (Na+ + K+)-ATPase of eel electric organ.

Interaction of lectins with a detergent-solubilized ATPase from eel electric organ was studied. Concanavalin A, which binds to alpha-mannosides, altered the rate of enzyme migration in agar and inhibited the formation of an antigen-antibody precipitate: other lectins had no such effects. Concanavalin A similar amounts partially inhibited (Na+ + K+)-ATPase; this inhibition was reversible by alpha-methylglucoside. There was no corresponding effect of concanavalin A on the potassium p-nitrophenylphosphatase. Concanavalin A also did not interfere with ouabain binding. Thus, concanavalin A binds to an antigenic region also involved in Na+ and/or ATP binding, but does not interact with a K+ site.     

The HIV epidemic in China： history, response, and challenge

The first case of AIDS was reported in 1985 in China, but by the early 21st century, the government estimated that there were 840,000 citizens living with HIV/AIDS. The number is increasing rapidly. The major risk groups are injection drug users （IDUSs; 43%） and former plasma donors （27%）, but rates among heterosexual groups are rising rapidly. Sentinel surveillance was initiated in 1986, and now includes IDUs, men-who-have-sex-with-men, sexually transmitted disease clinic attendees, antenatal women, long-distance truck drivers, and sex workers. Although the government was slow to respond to the epidemic in the late 20th century, it has made a vigorous response in the early 21st century. Components of that response include implementation and evaluation of harm reduction programs for IDUs, education to increase knowledge and reduce stigma, treatment and social support for rural and poor HIV/AIDS patients, widespread testing, and increased funding for HIV/AIDS programs. International agencies have been generous in their support of the government initiatives. To successfully combat the epidemic, China needs to develop and train the necessary infrastructure to implement its intervention programs, particularly in the rural areas, to vigorously combat stigma and discrimination, support research especially in the universities and research institutions other than the China Centers for Disease Control, develop a system for efficient exchange of research and program information, and update legislation to reflect the current situation.     

幽门螺杆菌致病岛CagL重组抗原的可溶性表达及其多克隆抗体的制备和分析*

目的:利用原核表达和蛋白质纯化技术获得高纯度的幽门螺杆菌致病岛CagL重组抗原(rCagL),利用其制备anti-CagL多克隆抗体,并分析抗体的特异性。方法:通过生物信息学软件分析rCagL的抗原结构;利用PCR长片段DNA合成技术合成不含有信号肽序列的幽门螺杆菌致病岛CagL基因,将其插入表达质粒pCzn1中,构建重组质粒pCzn1-rCagL。然后,将pCzn1-rCagL转入大肠杆菌Arctic Express中,经IPTG诱导表达后,通过Ni-IDA镍离子亲和层析纯化重组抗原rCagL,利用Western blot鉴定rCagL与His标签抗体和Anti-H. pylori抗体的免疫反应性;最后,通过rCagL辅以弗氏佐剂免疫BALB/c小鼠,制备anti-CagL多克隆抗血清,通过ELISA方法分析抗血清的特异性。结果:生物信息学软件表明重组抗原rCagL具有较好的抗原性质;重组质粒pCzn1-rCagL经双酶切和基因测序等技术鉴定,证实rCagL核苷酸序列与理论序列完全一致;基因工程菌株pCzn1-rCagL/Arctic Express在低温11℃条件经IPTG诱导表达。 SDS-PAGE实验结果证实:rCagL可实现相对高效地可溶性蛋白表达,可溶性蛋白约占包涵体的62.07%。经Ni-IDA亲和层析柱纯化,可获得高纯度rCagL,纯度约为96.6%。Western blot结果证实:重组抗原rCagL可特异性与His标签抗体和Anti-H. pylori抗体结合。ELISA结果证实:经rCagL免疫小鼠制备的多克隆抗体anti-CagL可特异性识别rCagL和H. pylori裂解物,具有较高的抗体特异性。结论:重组抗原rCagL在低温条件下可实现可溶性表达,经纯化可获得高纯度抗原蛋白;rCagL具有较好的抗原性,制备的多克隆抗体具有较好的免疫特异性,为发展H. pylori相关诊断试剂奠定了实验基础。     

基于Taqman-MGB探针的亚稀褶红菇实时荧光定量PCR检测方法

本研究建立了一种基于Taqman-MGB探针的亚稀褶红菇Russula subnigricans实时荧光定量PCR检测方法。根据亚稀褶红菇与其近似种的内转录间隔区（internal transcribed spacers,ITS）序列差异,设计合成1对引物和1条特异性Taqman-MGB探针,并用常见有毒红菇种类进行验证。结果显示,引物特异性良好,仅亚稀褶红菇出现荧光信号,完成整个检测过程只需2h。该法能够为毒蘑菇中毒的快速检测提供技术支持。