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排序方式: 共有327条查询结果,搜索用时 15 毫秒
1.
Takashi Yutsudo Hisao Kurazono Chihiro Sasakawa Masanosuke Yoshikawa Makoto Iwaya Tae Takeda Yoshifumi Takeda 《FEMS microbiology letters》1987,48(1-2):273-276
Abstract A Vero toxin (VT2 or Shiga-like toxin II)-converting phage was isolated from Escherichia coli 0157: H7 strain J-2. Nontoxigenic E. coli C600 produced VT2 when lysogenized with the toxin-converting phage. Eco RI fragments of the phage DNA were ligated with Eco RI-digested pBR322 or pUC118 and were transformed into E. coli MC1061 or MV1184. Transformants exhibiting VT2 production commonly contained a 4.6 kb Eco RI fragment. It was found that a 2.3 kb Kpn I- Sph I fragment coded VT2 production and that this fragment hybridized weakly with the 2.1 kb fragment encoding VT1. 相似文献
2.
A repeating unit of the DYZ1 family on the human Y chromosome consists of segments with partial male-specificity 总被引:1,自引:0,他引:1
Y Nakagome S Nagafuchi S Seki Y Nakahori T Tamura M Yamada M Iwaya 《Cytogenetics and cell genetics》1991,56(2):74-77
An average-sized human Y chromosome contains about 3,000 copies of the repeating DNA family DYZ1. A major repeating unit of the family, pHY10, has been cloned and an entire 3,564-bp sequence has already been determined by Nakahori et al. (1986). In the present study, pHY10 was divided into six consecutive segments, A to F, which were independently amplified by the PCR technique to see if they were strictly male-specific. pHY10 appears to consist of segments of various male-specificity. The B segment was apparently male-specific; however, the use of additional techniques (Southern-blot analysis or second PCR amplification in combination with the standard PCR) revealed homologous sequences in some females. None of the six segments of pHY10 may be male-specific in a strict sense. Different segments appear to be conserved during evolution to different extents. The 323-bp E segment appears to be the least conserved and to be responsible for the generation of most variations within the DYZ1 family. 相似文献
3.
An NAD+-linked 17 beta-hydroxysteroid dehydrogenase was purified to homogeneity from a fungus, Cylindrocarpon radicicola ATCC 11011 by ion exchange, gel filtration, and hydrophobic chromatographies. The purified preparation of the dehydrogenase showed an apparent molecular weight of 58,600 by gel filtration and polyacrylamide gel electrophoresis. SDS-gel electrophoresis gave Mr = 26,000 for the identical subunits of the protein. The amino-terminal residue of the enzyme protein was determined to be glycine. The enzyme catalyzed the oxidation of 17 beta-hydroxysteroids to the ketosteroids with the reduction of NAD+, which was a specific hydrogen acceptor, and also catalyzed the reduction of 17-ketosteroids with the consumption of NADH. The optimum pH of the dehydrogenase reaction was 10 and that of the reductase reaction was 7.0. The enzyme had a high specific activity for the oxidation of testosterone (Vmax = 85 mumol/min/mg; Km for the steroid = 9.5 microM; Km for NAD+ = 198 microM at pH 10.0) and for the reduction of androstenedione (Vmax = 1.8 mumol/min/mg; Km for the steroid = 24 microM; Km for NADH = 6.8 microM at pH 7.0). In the purified enzyme preparation, no activity of 3 alpha-hydroxysteroid dehydrogenase, 3 beta-hydroxysteroid dehydrogenase, delta 5-3-ketosteroid-4,5-isomerase, or steroid ring A-delta-dehydrogenase was detected. Among several steroids tested, only 17 beta-hydroxysteroids such as testosterone, estradiol-17 beta, and 11 beta-hydroxytestosterone, were oxidized, indicating that the enzyme has a high specificity for the substrate steroid. The stereospecificity of hydrogen transfer by the enzyme in dehydrogenation was examined with [17 alpha-3H]testosterone. 相似文献
4.
The mechanism of replication of phi X174 single-stranded DNA. II. The role of viral proteins 总被引:17,自引:0,他引:17
We have studied the replication of φX174 DNA in Escherichia coli infected with various amber mutants (cistrons I to VII) of φX. Previous research showing that some of these mutants are able to form replicative form (RF) DNA but are unable to produce net amounts of viral progeny single-stranded DNA has been confirmed and extended. Evidence is presented that a defect in any one of four viral cistrons prevents the asymmetric replication of the RF to produce progeny viral DNA. At least four virus-coded proteins, three of which are part of the mature virion, must be present before single-stranded DNA synthesis can even be initiated; the possibility that single-stranded DNA is made and then degraded or converted to RF is eliminated. Mutants in one cistron (II) do permit the asymmetric replication of RF at late times, but the displaced viral strand is incorporated into a defective particle and subsequently may be partially degraded. Both RFI (superhelix) and RFII are present in roughly comparable amounts throughout the normal latent period in infections with wild-type phage or any of the phage mutants. 相似文献
5.
Yuzo Yamada Minako Matsuda Kozaburo Mikata 《Journal of industrial microbiology & biotechnology》1995,14(6):456-460
Summary Two strains ofEeniella nana were examined for their partial base sequences of 18S and 26S rRNAs. In the partial base sequences of 18S rRNA (prositions 1451 through 1618, 168 bases) the strains ofE. nana have five, five, four and eleven base differences with those ofDekkera bruxellensis (type species).D. anomala (andBrettanomyces anomalus),D. naardenensis andD. custersiana, respectively. In the 26S rRNA partial base sequencings (positions 1611 through 1835, 225 bases and positions 493 through 622, 130 bases) the base differences were 46, 43, 34 and 40 and the percent similarities were 53–54, 51–54, 56–57 and 51–53, respectively. The sequence data obtained are discussed phylogenetically and taxonomically, especially on retention of the generic nameEeniella.This paper is dedicated to Professor Herman Jan Phaff in honor of his 50 years of active research which still continues.Significance of the coenzyme Q system in the classification of yeasts and yeast-like organisms. Part LVIII. For part LVII, see ref. [20]. 相似文献
6.
Kohji Moriishi Minako Koura Fumio Amano 《FEMS immunology and medical microbiology》1996,16(3-4):213-222
Abstract Listeria monocytogenes replicates in a phagocytic cell following escape into the host cytoplasm. Listeriolysin O, secreted by L. monocytogenes , which belongs to the thiol-activated hemolysin family, is known to play an important role in the escape of the bacterium into the host cytoplasm. In this study, we demonstrated that expression of listeriolysin O by infecting L. monocytogenes was lightly induced in J774.1 macrophage-like cells pretreated with lipopolysaccharide, although the growth of the bacteria was suppressed. The number of viable L. monocytogenes decreased until 4 h post-infection and then increased between 4 and 8 h post-infection in untreated J774.1 host cells, but it decreased until 8 h post-infection in lipopolysaccharide-treated host cells. However, expression of listeriolysin O by L. monocytogenes was not induced in the untreated host cells, while it increased between 0 and 4 h post-infection in the lipopolysaccharide-treated host cells. Expression of listeriolysin O mRNA in the lipopolysaccharide-treated host cells was also induced at 2 h post-infection, suggesting that listeriolysin O was newly synthesized in the macrophage-like cells. These results suggest that macrophage activation induced with lipopolysaccharide could lead to the expression of the listeriolysin O gene and the synthesis of listeriolysin O protein under suppression of the intracellular growth of L. monocytogenes . 相似文献
7.
Ren Matsuba Kensuke Sakai Minako Imamura Yasushi Tanaka Minoru Iwata Hiroshi Hirose Kohei Kaku Hiroshi Maegawa Hirotaka Watada Kazuyuki Tobe Atsunori Kashiwagi Ryuzo Kawamori Shiro Maeda 《PloS one》2015,10(5)
AimWe performed a replication study in a Japanese population to evaluate the association between type 2 diabetes and 7 susceptibility loci originally identified by European genome-wide association study (GWAS) in 2012: ZMIZ1, KLHDC5, TLE1, ANKRD55, CILP2, MC4R, and BCAR1. We also examined the association of 3 additional loci: CCND2 and GIPR, identified in sex-differentiated analyses, and LAMA1, which was shown to be associated with non-obese European type 2 diabetes.MethodsWe genotyped 6,972 Japanese participants (4,280 type 2 diabetes patients and 2,692 controls) for each of the 10 single nucleotide polymorphisms (SNPs): rs12571751 in ZMIZ1, rs10842994 near KLHDC5, rs2796441 near TLE1, rs459193 near ANKRD55, rs10401969 in CILP2, rs12970134 near MC4R, rs7202877 near BCAR1, rs11063069 near CCND2, rs8108269 near GIPR, and rs8090011 in LAMA1 using a multiplex polymerase chain reaction invader assay. The association of each SNP locus with the disease was evaluated using a logistic regression analysis.ResultsAll SNPs examined in this study had the same direction of effect (odds ratio > 1.0, p = 9.77 × 10-4, binomial test), as in the original reports. Among them, rs12571751 in ZMIZ1 was significantly associated with type 2 diabetes [p = 0.0041, odds ratio = 1.123, 95% confidence interval 1.037–1.215, adjusted for sex, age and body mass index (BMI)], but we did not observe significant association of the remaining 9 SNP loci with type 2 diabetes in the present Japanese population (p ≥ 0.005). A genetic risk score, constructed from the sum of risk alleles for the 7 SNP loci identified by un-stratified analyses in the European GWAS meta-analysis were associated with type 2 diabetes in the present Japanese population (p = 2.3 × 10-4, adjusted for sex, age and BMI).ConclusionsZMIZ1 locus has a significant effect on conferring susceptibility to type 2 diabetes also in the Japanese population. 相似文献
8.
The role of the infecting viral strand in the replication of bacteriophage φX174 replicative form DNA was studied by [3H]thymidine pulse-labeling Escherichia coli cells infected with 2H15N density-labeled phage. The products of a round of semi-conservative replicative form replication (in light medium) do not contain the original heavy viral strand by 15 minutes after infection or later in the presence of chloramphenicol. Similar results were obtained at earlier times in the absence of chloramphenicol. We conclude that the parental viral strand need not be conserved in the replicating DNA structure in succeeding rounds of replication. 相似文献
9.
Polymorphisms of interferon-inducible genes OAS-1 and MxA associated with SARS in the Vietnamese population 总被引:9,自引:0,他引:9
Hamano E Hijikata M Itoyama S Quy T Phi NC Long HT Ha LD Ban VV Matsushita I Yanai H Kirikae F Kirikae T Kuratsuji T Sasazuki T Keicho N 《Biochemical and biophysical research communications》2005,329(4):1234-1239
We hypothesized that host antiviral genes induced by type I interferons might affect the natural course of severe acute respiratory syndrome (SARS). We analyzed single nucleotide polymorphisms (SNPs) of 2',5'-oligoadenylate synthetase 1 (OAS-1), myxovirus resistance-A (MxA), and double-stranded RNA-dependent protein kinase in 44 Vietnamese SARS patients with 103 controls. The G-allele of non-synonymous A/G SNP in exon 3 of OAS-1 gene showed association with SARS (p=0.0090). The G-allele in exon 3 of OAS-1 and the one in exon 6 were in strong linkage disequilibrium and both of them were associated with SARS infection. The GG genotype and G-allele of G/T SNP at position -88 in the MxA gene promoter were found more frequently in hypoxemic group than in non-hypoxemic group of SARS (p=0.0195). Our findings suggest that polymorphisms of two IFN-inducible genes OAS-1 and MxA might affect susceptibility to the disease and progression of SARS at each level. 相似文献
10.
Qizhi Fang Pamela Y. Mok Anila E. Thomas Daniel J. Haddad Shereen A. Saini Brian T. Clifford Neel K. Kapasi Olivia M. Danforth Minako Usui Weisheng Ye Emmy Luu Rikki Sharma Maya J. Bartel Jeremy A. Pathmanabhan Andrew A. S. Ang Richard E. Sievers Randall J. Lee Matthew L. Springer 《PloS one》2013,8(4)
Pleiotrophin (PTN) is a growth factor with both pro-angiogenic and limited pro-tumorigenic activity. We evaluated the potential for PTN to be used for safe angiogenic gene therapy using the full length gene and a truncated gene variant lacking the domain implicated in tumorigenesis. Mouse myoblasts were transduced to express full length or truncated PTN (PTN or T-PTN), along with a LacZ reporter gene, and injected into mouse limb muscle and myocardium. In cultured myoblasts, PTN was expressed and secreted via the Golgi apparatus, but T-PTN was not properly secreted. Nonetheless, no evidence of uncontrolled growth was observed in cells expressing either form of PTN. PTN gene delivery to myocardium, and non-ischemic skeletal muscle, did not result in a detectable change in vascularity or function. In ischemic hindlimb at 14 days post-implantation, intramuscular injection with PTN-expressing myoblasts led to a significant increase in skin perfusion and muscle arteriole density. We conclude that (1) delivery of the full length PTN gene to muscle can be accomplished without tumorigenesis, (2) the truncated PTN gene may be difficult to use in a gene therapy context due to inefficient secretion, (3) PTN gene delivery leads to functional benefit in the mouse acute ischemic hindlimb model. 相似文献