丙型肝炎病毒基因组部份NS5区蛋白基因在大肠杆菌中的表达

在大肠杆菌中表达了丙型肝炎病毒基因组ＮＳ５区Ａ段和部份Ｂ段蛋白。ＮＳ５Ａ蛋白溶于水,可经过ＧＳＴ亲和层析柱纯化;ＮＳ５Ｂ蛋白不溶于水,经ＰＢＳ－Ｔｒｉｔｏｎ Ｘ－１００洗涤,尿素溶解后,通过离子交换柱纯化。经ＳＤＳ－ＰＡＧＥ和Ｗｅｓｔｅｍｂｌｏｔ分析,ＮＳ５Ａ蛋白除在５７ｋＤ左右有条带外,还有不同程度的降解产物;ＮＳ５Ｂ蛋白主要在５８ｋＤ左右有条带出现。为查明表达蛋白抗体在病人血清中的分布,取９     

L－赖氨酸快速发酵新菌种及工艺研究

以我室选育的赖氨酸生产菌Ｓ－２１－２４为出发菌株,经硫酸二乙酯（ＤＥＳ）和紫外线（Ｕ．Ｖ．）的复合处理,选育到一株代谢速率高,发酵周期短的新菌株ＦＴＳ－１。对该菌的发酵条件作了研究,选择了最佳培养条件,该菌在５Ｌ发酵罐中发酵４８小时产酸８０ｇ／Ｌ以上,７２小时产酸可达１１０ｇ／Ｌ。     

复合氨基酸治疗眼角膜溃疡的研究

复合氨基酸在临床上的应用越来越被人们重视,我们利用水解猪血粉的方法得到含１７种氨基酸的复合液,配制成滴眼剂用于多种原因引起的眼角膜溃疡疾病的治疗研究取得了较好的效果。     

植食性同翅目昆虫寻找和接受植物韧皮部过程中的细胞与化学探试(英文)

植食性同翅目昆虫在最终接受其宿主植物的过程中,将感受从叶表层直到韧皮部筛管途中存在的多种化学物质,并导致不同的刺探和取食行为。本文就植物叶表层存在的糖类和生物碱类物质,叶肉层的多糖类、酸碱度和酚类物质以及韧皮部内的氨基酸、蛋白质、碳水化合物和植物次生物质等对昆虫寻找及取食韧皮部行为的影响作一综述,并且还探讨了植物叶肉层的细胞结构对昆虫刺探及取食行为的可能影响。此外,结合刺探电位(electrical penetration graphs,EPGs)的研究结果,还讨论了昆虫感受植物叶组织内部的各种化学和细胞结构信息的可能机制。     

儿童唾液中细菌总数的测定

本文将昆明地区１１－１５岁健康儿童９０名按不同的口腔条件分为三组,每组３０人。采用培养基表面主培养主数法,分别测定唾液中厌氧菌和需氧菌细菌总数。结果表明：儿童唾液中细菌总数,牙颌畸形组、正畸组、正常组,三组间结果在统计学无显著差异。     

植酸钠对黑曲霉柠檬酸发酵产酸的促进效应

研究了植酸钠对黑曲霉柠檬酸发酵产酸的促进效应。在葡萄糖全合成培养基中添加１％的植酸钠,可使产酸比对照提高２．４倍;在薯粉、玉米粉等天然培养基中添加１％植酸钠,柠檬酸产量分别提高１．７倍和１．３倍。酶活性测定分析表明,植酸钠对柠檬酸代谢途径中的几种关键酶的活性有影响。     

Translocation of N-terminal tails across the plasma membrane.

Previously we have shown that the first hydrophobic domain of leader peptidase (lep) can function to translocate a short N-terminal 18 residue antigenic peptide from the phage Pf3 coat protein across the plasma membrane of Escherichia coli. We have now examined the mechanism of insertion of N-terminal periplasmic tails and have defined the features needed to translocate these regions. We find that short tails of up to 38 residues are efficiently translocated in a SecA- and SecY-independent manner while longer tails are very poorly inserted. Efficient translocation of a 138 residue tail is restored and is Sec-dependent by the addition of a leader sequence to the N-terminus of the protein. We also find that while there is no amphiphilic helix requirement for N-terminal translocation, there is a charge requirement that is needed within the tail; an arginine and lysine residue can inhibit or completely block translocation when introduced into the tail region. Intriguingly, the membrane potential is required for insertion of a 38 residue tail but not for a 23 residue tail.     

Transformation of Mycoplasma gallisepticum with Tn916, Tn4001, and integrative plasmid vectors.

Mycoplasma gallisepticum causes respiratory disease in avian species, but little is known about its mechanism(s) of pathogenesis. These studies were undertaken in order to develop genetic systems for analysis of potential virulence factors. M. gallisepticum was transformed with plasmids containing one of the gram-positive transposons Tn916 or Tn4001, which inserted randomly into the mycoplasmal chromosome. Plasmids containing cloned chromosomal DNA were also constructed and tested for integration into regions of DNA homology derived either from chromosomal fragments or from the gentamicin resistance marker from Tn4001. These studies demonstrate that M. gallisepticum is amenable to transformation with both transposons and integrative vectors.     

Phylogenetic relationships among eutherian orders estimated from inferred sequences of mitochondrial proteins: Instability of a tree based on a single gene

The phylogenetic relationships among Primates (human), Artiodactyla (cow), Cetacea (whale), Carnivora (seal), and Rodentia (mouse and rat) were estimated from the inferred amino acid sequences of the mitochondrial genomes using Marsupialia (opossum), Aves (chicken), and Amphibia (Xenopus) as an outgroup. The overall evidence of the maximum likelihood analysis suggests that Rodentia is an outgroup to the other four eutherian orders and that Cetacea and Artiodactyla form a clade with Carnivora as a sister taxon irrespective of the assumed model for amino acid substitutions. Although there remains an uncertainty concerning the relation among Artiodactyla, Cetacea, and Carnivora, the existence of a clade formed by these three orders and the outgroup status of Rodentia to the other eutherian orders seems to be firmly established. However, analyses of individual genes do not necessarily conform to this conclusion, and some of the genes reject the putatively correct tree with nearly 5% significance. Although this discrepancy can be due to convergent or parallel evolution in the specific genes, it was pointed out that, even without a particular reason, such a discrepancy can occur in 5% of the cases if the branching among the orders in question occurred within a short period. Due to uncertainty about the assumed model underlying the phylogenetic inference, this can occur even more frequently. This demonstrates the importance of analyzing enough sequences to avoid the danger of concluding an erroneous tree.     

Regulation of μ-Opioid Receptor mRNA in Rat Globus Pallidus: Effects of Enkephalin Increases Induced by Short- and Long-Term Haloperidol Administration

Abstract: The mRNA encoding μ-opioid receptors is expressed in neurons of the globus pallidus, a region of the basal ganglia that receives a dense enkephalinergic innervation from the striatum. The regulation of the mRNAs encoding the opioid peptide enkephalin in the striatum and the μ-opioid receptor in the globus pallidus was examined with in situ hybridization histochemistry following short- or long-term haloperidol treatments, which alter striatal enkephalin mRNA levels. Animals were administered haloperidol daily for 3 or 7 days (1 mg/kg, s.c.) or continuously for 8 months (1 mg/kg, depot followed by oral). Enkephalin and μ-opioid receptor mRNA levels were unchanged after 3 days of haloperidol treatment. In contrast, the enkephalin mRNA level was increased in the striatum, and μ-opioid receptor mRNA levels were markedly decreased in the globus pallidus after 7 days of haloperidol administration. Similar effects were observed in rats treated with haloperidol for 8 months. The results provide the first evidence of regulation of μ-opioid receptor mRNA in vivo.