拉萨郊区藏族跖纹主线走向分析

本文用茚三酮－味精法采集跖纹,体视显微镜下追踪跖纹主线走向,分析了２５０（男女各１２５人）拉萨效区藏族健康人的跖纹样本。结果显示：Ａ线主要走向１区,其次是７区;Ｂ线亦多止于１区和７区;Ｃ线主要止于和９区;Ｄ线止于１区 频率最高;Ｅ线主要走向１３区;Ｐ三叉缺失较多。Ｐｚ＾ｄ线止共位置较高（１３区和１１区）,而Ｐ＾ｆ线止区较低（７区）。在民族和人种间进行了比较,提示藏族践纹主线走向有自己的特点,又呈现     

精制白喉毒素加β—丙氨酸后脱毒效果观察

精制白喉毒素加０．０２Ｍβ—丙氨酸,再加甲醛溶液经适当的时间解毒,即可转化为完全类毒化且无毒性逆转的精制白喉类毒素。此精白类的脱毒试验、毒性逆转试验、安全试验及效力试验均符合《中国生物制品规程》要求。在脱毒过程中絮状单位的损失明显低于单纯甲醛脱毒者,纯度亦相应得到了提高。     

Atomic composition of the hydrophobic and hydrophilic membrane sides of self-assembled SC3p hydrophobin.

The hydrophobin SC3p of Schizophyllum commune self-assembles into a 10-nm-thick amphipathic membrane at hydrophilic-hydrophobic interfaces. X-ray photoelectron spectroscopy of the hydrophobic membrane side of SC3p, assembled in vitro, showed an atomic composition similar to the calculated composition of SC3p when glycosylation was taken into account. The atomic composition measured at the hydrophilic membrane side deviated from that at the hydrophobic side and indicated the presence of a lower number of peptide bonds. High levels of S and N were detected only on mycelia carrying hydrophobic aerial hyphae, as expected with assembled SC3p present at the surface of these hyphae.     

Capsid assembly and involved function analysis of twelve core protein mutants of duck hepatitis B virus.

The roles of different regions of the duck hepatitis B virus (DHBV) core protein on viral capsid assembly and related functions were examined. Twelve deletion and insertion mutations which covered 80% of the DHBV C open reading frame were constructed and expressed in Escherichia coli. The N-terminal region (amino acids 3 to 66) of DHBV core protein was important for its tertiary structure and function in E. coli. The expressed core mutants without this region apparently inhibited E. coli growth. The results of transmission electron microscopy of E. coli thin sections, capsid agarose gel, and sucrose gradient sedimentation demonstrated that a few DHBV core mutants with insertion in the N terminus and deletion in the C terminus retained the ability to form core-like particles in E. coli. However, other mutations in most of N-terminal and central regions strongly inhibited the self-assembly ability of DHBV core protein in E. coli. In addition, the mutant with a C-terminal region deletion (amino acids 181 to 228) lost most of the nucleic acid-binding activity of the DHBV core protein.     

Deletion mapping of the rotavirus metalloprotein NS53 (NSP1): the conserved cysteine-rich region is essential for virus-specific RNA binding.

NS53 (NSP1), the gene 5 product of the group A rotaviruses, is a minor nonstructural protein of 486 to 495 amino acids which binds zinc and contains an amino-terminal highly conserved cysteine-rich region that may form one or two zinc fingers. To study the structure-function of the gene 5 product, wild-type and mutant forms of NS53 were produced by using a recombinant baculovirus expression system and a recombinant vaccinia virus/T7 (vTF7-3) expression system. Analysis of the RNA-binding activity of the wild-type NS53 immobilized onto protein A-Sepharose beads with NS53-specific antiserum showed that the protein exhibited specific affinity for all 11 rotavirus mRNAs. The use of short virus-specific RNA probes indicated that NS53 specifically recognizes an element located near the 5' ends of viral mRNAs. Analysis of the RNA-binding activity of deletion mutants of NS53 showed that the RNA-binding domain resides within the first 81 amino acids of the protein and that the highly conserved cysteine-rich region within this region of the protein is essential for the activity. Gel electrophoresis and Western immunoblot analyses of intracellular fractions derived from infected cells revealed that large amounts of NS53 were present in the cytosol and in association with the cytoskeletal matrix. Indirect immunofluorescence analysis of cells programmed to transiently express mutant forms of NS53 using vTF7-3 indicated that the intracellular localization domain resides between amino acids 84 and 176 of NS53. Together, these data show that the RNA-binding domain and the intracellular localization domain lie upstream from the region of NS53 previously determined not to be essential for replication of rotaviruses in cell culture (J. Hua and J. T. Patton, Virology 198:567-576, 1994).     

Abscisic Acid-Induced Membrane Potential Changes in Barley Aleurone Protoplasts: a Possible Relevance for the Regulation of rab Gene Expression

The effect of ABA on the membrane potential of barley (Hordeumvulgare cv. Himalaya) aleurone protoplasts was studied by measuringthe distribution of the lipophilic cation tetraphenylphosphonium(TPP⁺). The resting membrane potential (E_m) according to ourmeasurements with TPP⁺ is about –53 mV and is in agreementwith membrane potential values as measured with intracellularmicroelectrodes (about –55 mV). The TPP⁺-measurementscould demonstrate a clear dependence of the resting E_m on theexternal pH (pH_e). Stimulation of the protoplasts with ABA induced a transienthyperpolarization of the membrane to –62 mV as measuredwith TPP⁺. The hyperpolarization was ABA-concentration dependent. Inhibition of the H⁺-ATPases with the specific proton pump inhibitorsdiethylstilbestrol (DES) or Micanozole effectively preventedhyperpolarization. This indicates that the hyperpolarizationis consistent with the activation of plasma membrane H⁺-ATPases.The K⁺-inward rectifier inhibitor BaCl₂ was able to prolongthe hyperpolarization. This result suggests that the hyperpolarizationcauses the opening of K⁺-channels. The ABA-induced proton-pump activation may be involved in ABA-inducedgene-expression, as DES was able to inhibit this gene expression.BaCl₂ did only show a slight inhibitory effect on ABA-inducedgene-expression. (Received January 4, 1994; Accepted April 12, 1994)     

厚叶景天组织传感器的研究

利用厚叶景天的叶和茎组织作为生物催化材料,分别同二氧化碳气敏电极和氨气敏电极组合,研制了L－精氨酸传感器及,L－赖氨酸传感器。两种传感器的线性范围分别为1.0×10^-4 1.O×10^-3mol/L和8．0×10^-5—3.0×10^-3mol/L．检测下限分别为3．2×10^-5mol／L和2.2×10^-5mol/L,响应斜率分别为42.2mV／dec和41．4mv／dec。考察了两种传感器的回收率．结果表明,L－精氨酸传感器和L－赖氨酸传感器的回收率平均值分别为98．6％和101.6％,标准偏差分别为4.6％和4.0％。     

软紫草愈伤组织的初步培养

外植体来源不同的软紫草愈伤组织产生紫草色素的能力各异。６０Ｃｏ－ｒ射线辐照处理后的Ｈ２无性系愈伤组织生长量和色素产生均属上乘。改良ＭＳ基本培养基添加１毫克／升ＫＴ,０．５毫克／升ＩＡＡ,５％（Ｗ／Ｖ）蔗糖对愈伤组织培养较为适宜。马铃薯提取液对愈伤组织生长有明显的促进作用。     

马蹄香大小孢子发生及雌雄配子体形成

马蹄香（Ｓａｒｕｍａｈｅｎｒｙｉ,Ｏｌｉｖ．）花药壁的发育属双子叶型。花粉母细胞减数分裂为同时型,四分体主要为四面体形,少数为左右对称式排列。腺质绒毡层,其细胞可排列为不规则的两层,双核或多核。到单细胞花粉阶段,绒毡层细胞内切向壁上出现许多乌氏体。成熟花粉为２细胞型,圆球状,具单萌发沟。雌蕊６心皮,上部彼此分离、下部联合。倒生胚珠,双珠被,厚球心。胚囊发育蓼型。成熟胚囊为七细胞结构,但两个助细胞退化较早。