246 results on '"Yokoyama, Eiji"'
Search Results
202. THE RESPIRATORY EFFECTS OF EXPOSURES TO SO2-NO2 MIXTURE ON HEALTHY SUBJECTS
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YOKOYAMA, Eiji, primary
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- 1972
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203. Geometrical lsomers of Pentachlorobenzaldehyde Oxime
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Shinoda, Kiichi, primary, Shida, Takafumi, additional, Ohtsuka, Takaaki, additional, Uzuki, Tadashi, additional, and Yokoyama, Eiji, additional
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- 1973
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204. THE OBSTRUCTION OF SMALL AIRWAYS, TECHNIQUES FUNCTIONALLY TO DETECT IT
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YOKOYAMA, Eiji, primary
- Published
- 1973
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205. Effect of short-term exposure to ozone on the lecithin metabolism ofrat lung
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Yokoyama, Eiji and Ichikawa, Isamu
- Subjects
- *
LUNGS , *OZONE , *RATS , *TOXICOLOGY - Published
- 1982
206. Gene encoding a replication initiator protein and replication origin of conjugative plasmid pSA1.1 of Streptomyces cyaneus ATCC 14921
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Yokoyama, Eiji, Matsuzaki, Yumi, Doi, Katsumi, and Ogata, Seiya
- Abstract
pSA1.1 is a 9.1-kb multicopy plasmid originally isolated from Streptomyces cyaneus (formerly S. azureus) ATCC 14921. This plasmid accumulates single-stranded DNA in S. lividans and is therefore considered to replicate by a rolling-circle replication. In the present work, the rep gene encoding the replication initiator protein and the replication origin ori of pSA1.1 were determined. The rep and ori are located on separate regions. The Rep protein of pSA1.1 belongs to superfamily I which includes A proteins of phages. Nucleotide sequence of the surrounding putative nicking site of pSA1.1 shows good agreement with those of the pC194 group plasmids and phages. The direction of replication was also determined.
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- 1998
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207. Detection of the single-stranded DNA of Streptomyces plasmid pSA1.1 and a binding histone-like protein
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Yokoyama, Eiji, Doi, Katsumi, Kimura, Makoto, and Ogata, Seiya
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Streptomyces plasmid pSA1.1 accumulated single-stranded DNA as replication intermediates in S. lividans; therefore, this plasmid was considered to replicate by a rolling-circle mechanism. A DNA-binding protein (pI > 9.7 and about 10 kDa) was purified on a denatured DNA-Cellulose column, then on a native DNA-Cellulose column. The N-terminal amino acid sequence of this protein has a high homology with bacterial histone-like proteins. In the gel retardation assay, this protein bound with the single-stranded DNA of pSA1.1. We propose that this protein may participate in the replication of pSA1.1.
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- 1996
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208. Whole-Genome Sequences of Two Closely Related Bacteria, Actinomyces sp. Strain Chiba101 and Actinomyces denticolens DSM 20671 T .
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Kanesaki Y, Ishige T, Sekigawa Y, Kobayashi T, Torii Y, Yokoyama E, Ishiwata H, Hamada M, Tamura T, Azuma R, and Murakami S
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Actinomyces sp. strain Chiba101, isolated from an arthritic leg joint of a pig raised in Japan, is a bacterium closely related to Actinomyces denticolens Here, we deciphered the complete genome sequence of Actinomyces sp. Chiba101 and the high-quality draft genome sequence of A. denticolens DSM 20671
T ., (Copyright © 2017 Kanesaki et al.)- Published
- 2017
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209. Single-Nucleotide Polymorphisms in the Whole-Genome Sequence Data of Shiga Toxin-Producing Escherichia coli O157:H7/H- Strains by Cultivation.
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Yokoyama E, Hirai S, Ishige T, and Murakami S
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- Escherichia coli O157 classification, Phylogeny, Shiga-Toxigenic Escherichia coli classification, Escherichia coli O157 genetics, Genome, Bacterial genetics, Polymorphism, Single Nucleotide genetics, Shiga-Toxigenic Escherichia coli genetics
- Abstract
Nine Shiga toxin-producing Escherichia coli O157:H7/H- (O157) strains were serially cultured three times on LB agar plates. After each sub-culture, five colonies were picked for DNA isolation and whole genome sequence (WGS) analysis. After exclusion of possible recombination-related SNPs, 11, 9, and 34 single-nucleotide polymorphisms (SNPs) were detected in genes in the backbone, O-island, and mobile elements gene categories. This suggested that those SNPs due to cultivation could influence the threshold value set for molecular epidemiological studies of O157. Significant differences were observed by the Kruskal-Wallis test (P < 0.01) when the number of the SNPs in a strain was compared to that in other strains. This indicated that a specific number of strains could be used for setting the threshold value in molecular epidemiological studies. Due to cultivation, the SNPs were also detected in genes in a few core genome or core gene sets, suggesting that those SNPs could affect studies of phylogeny as well as molecular epidemiology. To improve the accuracy of phylogenetic and molecular epidemiological studies, genes in which the SNPs have arisen due to cultivation should be excluded from WGS data.
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- 2017
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210. Comparative analysis of Mycobacterium tuberculosis Beijing strains isolated in three remote areas of Japan.
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Yokoyama E, Hachisu Y, Iwamoto T, Nakanishi N, Arikawa K, Wada T, Seto J, and Kishida K
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- Genes, Bacterial, Humans, Japan, Minisatellite Repeats, Molecular Typing, Mycobacterium tuberculosis isolation & purification, Phylogeny, Rural Population, Sequence Analysis, DNA, Mycobacterium tuberculosis genetics, Tuberculosis, Pulmonary microbiology
- Abstract
A quantitative and qualitative comparison was carried out of Mycobacterium tuberculosis Beijing strains isolated in three remote areas of Japan. A total of 452 strains from Chiba Prefecture, 75 from Yamagata Prefecture, and 315 from Kobe City were analyzed for 24 loci by variable number of tandem repeats typing (24(Beijing)-VNTR). All strains were classified in six Beijing subgroups (B(SUB)), B1 to B5 and T, based on a minimum spanning tree reconstructed using data of a standard set of 15 VNTR loci. No significant difference was found in the distribution of strains in the B(SUB) in the three areas, with one exception due to a B5 outbreak in Yamagata, indicating no significant quantitative difference in the B(SUB) in the three areas (P<0.01, Chi-square test). In addition, when strains in each B(SUB) isolated in the three areas were mixed and standardized index of association (I(A)(s)) and variance (Φ(PT)) values were calculated, no significant qualitative difference in the B(SUB) in the three areas was found. These results suggested that the B(SUB) diverged prior to the introduction of M. tuberculosis Beijing strains into Japan. Differences in the distribution of strains in each B(SUB) between Japan and continental Asian countries suggested there had been genetic drift in the continental Asian countries in which B4 had been dominant., (Copyright © 2015 Elsevier B.V. All rights reserved.)
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- 2015
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211. An evolutionary analysis of nitric oxide reductase gene norV in enterohemorrhagic Escherichia coli O157.
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Shimizu T, Hirai S, Yokoyama E, Ichimura K, and Noda M
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- Escherichia coli O157 classification, Escherichia coli O157 metabolism, Escherichia coli O157 virology, Gene Deletion, Genotype, Mutation, Nitric Oxide, Oxidative Stress, Polymorphism, Single Nucleotide, Virulence genetics, Escherichia coli O157 genetics, Evolution, Molecular, Oxidoreductases genetics
- Abstract
A novel virulence gene, norV, that encodes nitric oxide (NO) reductase, was examined to investigate the emergence of enterohemorrhagic Escherichia coli (EHEC) O157 subgroup C clusters 2 and 3 from subgroup C cluster 1. Deletion of norV occurred at a point between cluster 1 and cluster 2 just after or at the same time that an stx2 bacteriophage, which retains Shiga toxin 2 gene, was inserted into wrbA, which encodes a novel multimeric flavodoxin-like protein, in EHEC O157. Sensitivity of NO to anaerobic growth was correlated with the deletion of norV in all EHEC O157 individuals tested. The C467A mutation of fimH, which encodes minor component of type 1 fimbriae, occurred within cluster 1, not as a transition from cluster 1 to cluster 2, indicating that there is a cluster 1 minority branch that leads to cluster 2. These data refine the evolutionary history of an emerging EHEC O157., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2015
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212. A novel subpopulation of Salmonella enterica serovar Infantis strains isolated from broiler chicken organs other than the gastrointestinal tract.
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Yokoyama E, Ando N, Ohta T, Kanada A, Shiwa Y, Ishige T, Murakami K, Kikuchi T, and Murakami S
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- Animals, Anti-Bacterial Agents pharmacology, Bayes Theorem, DNA Fingerprinting, Drug Resistance, Multiple, Bacterial, Electrophoresis, Gel, Pulsed-Field, Japan epidemiology, Microbial Sensitivity Tests, Phylogeny, Plasmids drug effects, Poultry Diseases epidemiology, Salmonella Infections, Animal epidemiology, Salmonella enterica drug effects, Salmonella enterica genetics, Serogroup, Chickens microbiology, Poultry Diseases microbiology, Salmonella Infections, Animal microbiology, Salmonella enterica classification
- Abstract
Salmonella enterica subsp. enterica serovar Infantis strains were isolated from broiler chickens from six farms in Japan and the pathogenicity associated with the recently reported 280kbp mega plasmid was examined by possession of the plasmid and histopathology of tissues from these chickens. S. Infantis strains were isolated from 10 of 24 chickens. Phylogenetic, network and Bayesian cluster analyses were used to determine whether these strains were in the previously defined Clusters 1-5. Phylogenetic analysis classified the strains isolated in this study in two groups (Groups A and B). Both groups contained strains from gastrointestional contents, but only Group A also contained strains from spleen, liver, and lymphoid tissues. Histopathology showed suppurative splenitis in a spleen from which Group A strains were isolated. Although network and Bayesian cluster analyses were unable to differentiate Group A and B strains from the previously defined Clusters 1-5, population genetic analysis indicated that Group A was a different population from Cluster 5, indicating that Group A would be a subpopulation of Cluster 5. The irp2 gene, which is in the mega plasmid carried by a pathogenic S. Infantis strain recently isolated in Israel, was found in both Groups A and B strains and in the previously reported Clusters 4 and 5 strains. These results suggested that Group A would be a novel subpopulation of the previously defined Cluster 5, and presence of the mega plasmid may not be related whether S. Infantis strains can infect certain organs., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2015
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213. Phylogenetic and population genetic analysis of Salmonella enterica subsp. enterica serovar Infantis strains isolated in Japan using whole genome sequence data.
- Author
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Yokoyama E, Murakami K, Shiwa Y, Ishige T, Ando N, Kikuchi T, and Murakami S
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- Animals, Chickens, Cluster Analysis, Food Microbiology, High-Throughput Nucleotide Sequencing, Humans, Japan, Meat, Polymorphism, Single Nucleotide, Poultry Diseases microbiology, Salmonella Infections microbiology, Salmonella Infections, Animal microbiology, Genetics, Population, Genome, Bacterial, Phylogeny, Salmonella enterica classification, Salmonella enterica genetics
- Abstract
Salmonella enterica subsp. enterica serovar Infantis has been reported to be carried asymptomatically in chickens and isolated from some human patients with diarrhea. The aim of this study was to investigate the phylogeny of S. Infantis strains isolated in Japan from chicken meat, chicken egg shells, environmental samples from a grading and packing center for chicken eggs (GP center), diarrhea patients, and asymptomatic carriers based on whole genome sequence data. The S. Infantis strains were in five clusters in a phylogenetic tree reconstructed by the maximum likelihood method. The five clusters were confirmed by neighbor-net and Bayesian cluster analyses. Two of the five clusters formed a group containing all of the strains isolated from chicken meat and some of the strains isolated from diarrhea patients and asymptomatic carriers. The median-joining network reconstructed in this study showed that strains in one of these two clusters diverged from one node with similar relatively short branches, suggesting clonal dissemination of these strains. The other three clusters formed a group containing all of the strains isolated from chicken egg shells and the GP center, and the remaining strains from diarrhea patients and asymptomatic carriers. Interestingly, strains isolated from patients did not cluster in only one group, indicating that none of the S. Infantis strains in this study had significantly higher human pathogenicity. The population genetic analyses in this study showed the separation of the five clusters into two groups was concordant with the sources where the strains in the clusters were isolated. These results suggested that evolutionary groups with higher hierarchy than the clusters identified in this study may be present, although such groups could not be determined by phylogenetic, neighbor-net, and Bayesian analyses in this study. Determination of higher level S. Infantis evolutionary groups should be investigated using other types of genetic markers., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2014
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214. Evolutionary model of the divergence of enterohemorrhagic Escherichia coli O157 lineage I/II clades reconstructed from high resolution melting and Shiga-like toxin 2 analyses.
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Etoh Y, Hirai S, Ichihara S, Maeda E, Yokoyama E, Sera N, Horikawa K, and Yamamoto T
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- Biological Evolution, Enterohemorrhagic Escherichia coli classification, Escherichia coli Infections microbiology, Genes, Bacterial genetics, Virulence Factors genetics, Colitis microbiology, Enterohemorrhagic Escherichia coli genetics, Escherichia coli O157 classification, Escherichia coli O157 genetics, Shiga Toxin 2 genetics
- Abstract
We have studied 167 epidemiologically unlinked strains of enterohemorrhagic Escherichia coli O157 (O157) isolated from patients with hemorrhagic colitis (HC), 87 strains from patients not with HC and 35 asymptomatic carriers (the not HC group), and differentiated these strains into clades using high resolution melting analysis. In addition, lineage analysis was carried out using lineage-specific polymorphism assay-6 and analysis of the distribution of IS629 insertion sites was carried out using IS-printing. Most strains were correctly clustered by minimum spanning tree analysis, and strains in the major clades showed linkage disequilibrium, confirming the clade differentiation in this study. The number of O157 strains in the different clades isolated from HC patients and the not HC group was significantly different (Chi square test, P<0.05), indicating that strains in different clades had different pathogenicities for hemorrhagic colitis. Pairwise comparison of the number of strains in different clades isolated from HC patients indicated that clade 12 strains were weakly pathogenic for HC. Stx2 titers and the number of strains carrying an stx2 gene were significantly different for different clades (Kruscal-Wallis test and Chi square test, P<0.05). Pairwise comparison of the Stx2 titer and the number of strains with an stx2 gene in different clades showed that the weak HC pathogenicity of clade 12 strains would be related to the low number of clade 12 strains with an stx2 gene and the low Stx2 production in those strains. Interestingly, the Stx2 titer and the prevalence of strains with an stx2 gene were significantly higher among clade 6 and 8 strains compared to clade 7 strains, although clades 6, 7, and 8 were all in lineage I/II. These results were discordant with the O157 evolutionary model, suggesting that insertion of an stx2 gene in lineage I/II strains after divergence of each clade., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2014
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215. [Analytical procedure of variable number of tandem repeats (VNTR) analysis and effective use of analysis results for tuberculosis control].
- Author
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Hachisu Y, Hashimoto R, Kishida K, and Yokoyama E
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- Genotype, Humans, Japan, Molecular Epidemiology methods, Polymerase Chain Reaction methods, Polymorphism, Restriction Fragment Length genetics, Tuberculosis prevention & control, Minisatellite Repeats genetics, Tuberculosis microbiology
- Abstract
Variable number of tandem repeats (VNTR) analysis is one of the methods for molecular epidemiological studies of Mycobacterium tuberculosis. VNTR analysis is a method based on PCR, provides rapid highly reproducible results and higher strain discrimination power than the restriction fragment length polymorphism (RFLP) analysis widely used in molecular epidemiological studies of Mycobacterium tuberculosis. Genetic lineage compositions of Mycobacterium tuberculosis clinical isolates differ among the regions from where they are isolated, and allelic diversity at each locus also differs among the genetic lineages of Mycobacterium tuberculosis. Therefore, the combination of VNTR loci that can provide high discrimination capacity for analysis is not common in every region. The Japan Anti-Tuberculosis Association (JATA) 12 (15) reported a standard combination of VNTR loci for analysis in Japan, and the combination with hypervariable (HV) loci added to JATA12 (15), which has very high discrimination capacity, was also reported. From these reports, it is thought that data sharing between institutions and construction of a nationwide database will progress from now on. Using database construction of VNTR profiles, VNTR analysis has become an effective tool to trace the route of tuberculosis infection, and also helps in decision-making in the treatment course. However, in order to utilize the results of VNTR analysis effectively, it is important that each related organization cooperates closely, and analysis should be appropriately applied in the system in which accurate control and private information protection are ensured.
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- 2013
216. Linkage disequilibrium of the IS629 insertion among different clades of enterohemorrhagic Escherichia coli O157:H7/H-strains.
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Hirai S, Yokoyama E, and Yamamoto T
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- Escherichia coli Infections microbiology, Escherichia coli O157 classification, Evolution, Molecular, Genome, Bacterial, Humans, Linkage Disequilibrium, Phylogeny, DNA Transposable Elements, Escherichia coli O157 genetics
- Abstract
The distribution of insertion sequence (IS) 629 was investigated among enterohemorrhagic Escherichia coli O157:H7/H-(O157) strains in different clades. Minimum spanning tree analysis showed that most strains in each clade clustered in a separate branch, indicating biased distribution of the IS629 insertion in different clades. The standardized index of association of the IS629 distribution data showed linkage disequilibrium in the strains in every clade, indicating that IS629 distribution data could be used for population genetic analysis. For this population genetic analysis, the Φ(PT) value, an analogue of F(ST), was calculated and indicated that clade 7 strains could be split into two clades based on their lineages. The degree of pairwise linkage disequilibrium was quite different among these two groups. The clade 7 split was in agreement with the model of O157 paraphyletic evolution and a new designation of the lineage II clades was proposed. The prevalence of strains with an IS629 insertion in certain loci was significantly different in different clades. Some of these significant differences were in loci in strains in branches of clades that were close in the O157 phylogenetic model, suggesting that IS629 insertion/deletion was not directly related to the divergence of O157 clades., (Copyright © 2013 Elsevier B.V. All rights reserved.)
- Published
- 2013
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217. Tonsilliphilus suis gen. nov., sp. nov., causing tonsil infections in pigs.
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Azuma R, Ung-Bok B, Murakami S, Ishiwata H, Osaki M, Shimada N, Ito Y, Miyagawa E, Makino T, Kudo T, Takahashi Y, Yano I, Murata R, and Yokoyama E
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- Actinomycetales genetics, Actinomycetales isolation & purification, Animals, Bacterial Typing Techniques, Base Composition, DNA, Bacterial genetics, Fatty Acids analysis, Molecular Sequence Data, Nucleic Acid Hybridization, Phospholipids analysis, RNA, Ribosomal, 16S genetics, Sequence Analysis, DNA, Swine Diseases microbiology, Vitamin K 2 analogs & derivatives, Vitamin K 2 analysis, Actinomycetales classification, Palatine Tonsil microbiology, Phylogeny, Swine microbiology
- Abstract
A micro-organism resembling members of the genus Dermatophilus, strain W254(T), which was isolated from the submandibular lymph node of a pig, and an additional 16 strains isolated from swine tonsils, were studied to establish their taxonomic status. Although all 17 strains were isolated anaerobically under an atmosphere of 100 % CO2, all of them were aerotolerant anaerobes. The micro-organisms showed at least five cellular morphologies: (i) a radially protrusive thallus, which proliferated into tuber-like cells; (ii) segmentation in both tubers and thallus followed by multilocule formation, (iii) development of coccoid forms in the locules; (iv) a change from the coccoid forms to zoospores; (v) resting cells, which were able to develop into protrusive thalli again. The micro-organisms were positive for nitrate reduction, but negative for catalase, indole production, hydrolysis of urea and gelatin liquefaction. Milk was not decomposed and none of the strains was haemolytic. A total of 16 compounds, including glucose, were utilized as sole carbon sources and seven compounds, including l-arabinose, were not utilized. Three out of the 17 strains were subjected to further studies. The micro-organisms had meso-diaminopimelic acid in their peptidoglycan and galactose, glucose, madurose and a trace of mannose in their whole-cell sugar patterns. The major phospholipids were phosphatidylglycerol, diphosphatidylglycerol and phosphatidylinositol.Cellular fatty acids were C15 : 0 (35.7-23.1 %), C16 : 0 (5.9-2.4 %) C17 : 0 (62.9-39.5 %), C17 : 1 (24.4-0 %) and C18 : 0 (3-1.6 %). The predominant menaquinone was MK-8 (H4). The G+C content of the DNA was 69.6-71.8 mol%. Analysis of the 16S rRNA gene sequences showed that the strains clustered with the type strains of members of the family Dermatophilaceae. Based on the polyphasic taxonomic characterization carried out, all 17 strains are considered to belong to a novel species in a new genus, for which the name Tonsilliphilus suis gen. nov., sp. nov. is proposed. The type strain of the type species is W254(T) ( = ATCC 35846(T) = CCM 3774(T) = DSM 21880(T) = JCM 15727(T)).
- Published
- 2013
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218. Clade analysis of enterohemorrhagic Escherichia coli serotype O157:H7/H- strains and hierarchy of their phylogenetic relationships.
- Author
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Yokoyama E, Hirai S, Hashimoto R, and Uchimura M
- Subjects
- Escherichia coli O157 genetics, Genes, Bacterial, Humans, Japan, Phylogeny, Polymorphism, Single Nucleotide, Escherichia coli Infections microbiology, Escherichia coli O157 classification
- Abstract
Enterohemorrhagic Escherichia coli serotype O157:H7/H-(O157) strains isolated in Chiba prefecture, Japan, during 2002-2009 were studied by lineage, subgroup, cluster, and clade analysis. Lineage analysis of 470 O157 strains with no known epidemiological relationships using lineage specific polymorphism assay-6 showed that there were 242 lineage I strains, 160 lineage I/II strains, 67 lineage II strains, and 1 atypical strain. Clade analysis of these strains by single nucleotide polymorphism in eight loci showed that lineage I contained all the clade 1, clade 2, and clade 3 strains, and some of the clade 4/5 strains. In contrast, clade 7, clade 8, and the remaining clade 4/5 strains were divided between lineage I/II and II, and clade 6 was in lineage I/II, suggesting paraphyletic evolution of these lineages. Cluster and subgroup analysis of the stx phage insertion site showed that all lineage I strains were cluster 3 and all lineage I/II and II strains, with the exception of clade 9, were in cluster 1. Clade analysis also indicated that there were three phylogenetic groups of clade 4/5 strains: ancestral groups containing lineage I/IIand II strains and a descendant group containing lineages I. Analysis of stx2c gene distribution showed that stx2c was in ancestral clade 4/5 strains but not in descendant 4/5 strains, suggesting that the ancestral group may be clade 4 as reported by Manning et al. The results with the markers used in this study suggested that the hierarchy of O157 phylogenetic relationships was lineage as the upper level, followed by subgroup and then cluster, and clade as the lowest level. The need for refinement of clade definition and modification of the model of the O157 evolution have been discussed., (Copyright © 2012 Elsevier B.V. All rights reserved.)
- Published
- 2012
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219. Expression analysis of the spi gene in the pock-forming plasmid pSA1.1 from Streptomyces azureus and localization of its product during differentiation.
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Doi K, Ohyama Y, Yokoyama E, Nishiyama T, Fujino Y, Nagayoshi Y, Ohshima T, and Ogata S
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- Bacterial Proteins genetics, Cytosol chemistry, Gene Dosage, Microscopy, Confocal, Streptomyces cytology, Streptomyces genetics, Bacterial Proteins analysis, Gene Expression Profiling, Plasmids, Streptomyces chemistry, Streptomyces growth & development
- Abstract
The sporulation inhibitory gene spi in the pock-forming conjugative plasmid pSA1.1 of Streptomyces azureus was introduced into cells via a high or low copy number vector to examine the effect of gene dosage on the growth of Streptomyces lividans TK24 as a host. In transformants carrying a high spi copy number, nutrient mycelial growth was inhibited, as was morphological differentiation from substrate mycelium to aerial mycelium on solid media. The degree of inhibition depended on the spi gene dosage, but the presence of pSA1.1 imp genes, which encode negative repressor proteins for spi, relieved the inhibition. Confocal images of Spi tagged with enhanced green fluorescent protein in cells on solid media revealed that spi expression was initiated at the time of elongation of substrate mycelium, that its expression increased dramatically at septation in aerial hyphae, and that the expression was maximal during prespore formation. Expression of spi covered the whole of the hyphae, and the level of expression at the tip of the hyphae during prespore formation was about sixfold greater than during substrate mycelial growth and threefold greater than during aerial mycelial growth. Thus, localized expression of spi at particular times may inhibit sporulation until triggering imp expression to repress its inhibitory effects.
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- 2012
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220. Population genetic analysis of Mycobacterium tuberculosis Beijing subgroup strains.
- Author
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Yokoyama E, Hachisu Y, Hashimoto R, and Kishida K
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- DNA, Bacterial, Emigrants and Immigrants, Female, Genetic Variation, Humans, Male, Minisatellite Repeats, Mycobacterium tuberculosis isolation & purification, Phylogeny, Bacterial Typing Techniques, Multilocus Sequence Typing, Mycobacterium tuberculosis classification, Mycobacterium tuberculosis genetics
- Abstract
Population genetic analysis using variable-number tandem repeat (VNTR) data of 23 loci (15 "optimized MIRU" loci and eight "Beijing option" loci) was done on Mycobacterium tuberculosis Beijing lineage strains isolated in Japan. These strains were divided into Beijing subgroups (B(SUB)) B1-B5 and T2 by minimum spanning tree (MST) analysis. The Φ(PT) values among the B(SUB), a measure of their molecular variance, were significantly different from zero with 999 permutations, indicating the validity of B(SUB) classification using the 23 VNTR loci. Higher number of migrants (Nm) values were observed between B1 and T2, B4 and T2, B3 and T2, and B3 and B4 in a phylogenetic network model reconstructed from previously reported single-nucleotide polymorphism (SNP) data. These B(SUB) combinations, except B3 and B4, shared SNP types; i.e., ST19 was in B1 and T2 and in B4 and T2, and STK was in B3 and T2. These results taken together suggested that shared SNP types were not due to homoplasy, but to strong genetic relatedness between those B(SUB). Haploid genetic diversity and standardized index of association values were different in each B(SUB), indicating that the diversity of each B(SUB) was different. Although the differences in B(SUB) diversity were mostly in accordance with the relative divergence order of the B(SUB) in a phylogenetic network model, the diversity of B4 was biased by a significant increase in the number of strains in this study from patients born after 1964 (Fisher's exact test P<0.01). The different diversity of each B(SUB) indicated increased diversity of Beijing lineage strains, perhaps contributing to the survival and dissemination of these strains., (Copyright © 2011 Elsevier B.V. All rights reserved.)
- Published
- 2012
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221. Emergence of enterohemorrhagic Escherichia coli serovar O157 strains in clade 8 with highly similar pulsed-field gel electrophoresis patterns.
- Author
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Yokoyama E, Etoh Y, Ichihara S, Horikawa K, Konishi N, Kai A, Matsumoto Y, Kurosaki M, Kasahara H, Kurazono T, and Yoda K
- Subjects
- Bacterial Typing Techniques, Electrophoresis, Gel, Pulsed-Field, Escherichia coli Infections epidemiology, Food Microbiology, Genes, Bacterial, Humans, Japan epidemiology, Linkage Disequilibrium, DNA, Bacterial analysis, Escherichia coli Infections microbiology, Escherichia coli O157 classification, Escherichia coli O157 genetics, Polymorphism, Single Nucleotide
- Abstract
Enterohemorrhagic Escherichia coli serovar O157 (O157) strains with highly similar pulsed-field gel electrophoresis (PFGE) patterns were isolated in Japan during 2007 and 2008. Several genetic features related to O157 evolution were investigated to indicate whether homoplasy might have contributed to the highly similar PFGE patterns in these strains. The O157 strains were classified in lineage I/II, as defined by a lineage-specific polymorphism assay-6 with an atypical allele in Z5935 (code: 231111). Analysis of the insertion sites of stx(2) phage in these strains showed that the sites were "occupied" in yehV and "intact" in wrbA, indicating that the strains were derived from "Cluster 1" of "Subgroup C." When a specific single-nucleotide polymorphism in ECs2357 in clade 8 strains was investigated, all of the strains in the present study were confirmed to be clade 8 strains. These results indicated that the O157 strains in this study had common genetic features, suggesting that the highly similar PFGE patterns of these strains were not due to homoplasy. Because no common source of these strains could be identified in 2007 to 2008 in Japan, these strains may have emerged from a unique O157 clade 8 clone and then spread by dissemination in Japan.
- Published
- 2011
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222. Biased distribution of IS629 among strains in different lineages of enterohemorrhagic Escherichia coli serovar O157.
- Author
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Yokoyama E, Hashimoto R, Etoh Y, Ichihara S, Horikawa K, and Uchimura M
- Subjects
- Electrophoresis, Gel, Pulsed-Field, Escherichia coli O157 genetics, Genes, Bacterial, Linkage Disequilibrium, Minisatellite Repeats, Escherichia coli O157 classification
- Abstract
The distribution of insertion sequence (IS) 629 among strains of enterohemorrhagic Escherichia coli serovar O157 (O157) was investigated and compared with the strain lineages defined by lineage specific polymorphism assay-6 (LSPA-6) to demonstrate the effectiveness of IS629 analysis for population genetics analysis. Using pulsed-field gel electrophoresis and variable-number tandem repeat typing, 140 strains producing both VT1 and VT2 and 98 strains producing only VT2 were selected from a total of 592 strains isolated from patients and asymptomatic carriers in Chiba Prefecture, Japan, during 2003-2008. By LSPA-6 analysis, six strains had atypical amplicon sizes in their Z5935 loci and five strains had atypical amplicon sizes in their arp-iclR intergenic regions. Sequence analyses of PCR amplified DNAs showed that five of the six loci used for LSPA-6 analysis had tandem repeats and the allele changes were due to changes in the number of tandem repeats. Subculturing and long-term incubation was found to have no detectable effect on the lineages defined by LSPA-6 analysis, demonstrating the robustness of LSPA-6 analysis. Minimum spanning tree analysis reconstruction revealed that strains in lineage I, I/II, and II clustered on separate branches, indicating that the distribution of IS629 was biased among O157 strains in different lineages. Strains with LSPA-6 codes 231111, 211113, and 211114 had atypical amplicon sizes and were clustered in lineage I/II branch, and strains with LSPA-6 codes 212114, 221123, 221223, 222123, 222224, 242123, 252123, and 242222 had atypical amplicon sizes and clustered in lineage II branches. Linkage disequilibrium was observed in strains in every lineage when the standardized index of association was calculated using IS629 distribution data. Therefore, the distribution analysis of IS629 may be effective for population genetics analysis of O157 due to the biased IS629 distribution among strains in the three O157 lineages., (Copyright © 2010 Elsevier B.V. All rights reserved.)
- Published
- 2011
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223. Concordance of variable-number tandem repeat (VNTR) and large sequence polymorphism (LSP) analyses of Mycobacterium tuberculosis strains.
- Author
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Yokoyama E, Hachisu Y, Hashimoto R, and Kishida K
- Subjects
- DNA, Bacterial genetics, Evolution, Molecular, Linkage Disequilibrium, Phylogeny, Minisatellite Repeats, Mycobacterium tuberculosis classification, Mycobacterium tuberculosis genetics, Polymorphism, Genetic
- Abstract
Variable-number tandem repeat (VNTR) and large sequence polymorphism (LSP) analyses were compared to determine whether VNTR analysis was effective for population genetic analysis of Mycobacterium tuberculosis strains. A total of 682 strains, 510 Beijing genotype and 172 non-Beijing genotype strains, were studied. The number of repeats was investigated for 24 VNTR loci: the 15 loci of "optimized miru", the 8 loci of "Beijing option", and 1 locus for "JATA12". Six loci (miru31, Mtub4, QUB4156c, QUB3232, VNTR3820, and VNTR4120) showed significantly different median numbers of repeats in strains belonging to different lineages defined by LSP (P<0.01, Mann-Whitney U test). When a minimum-spanning tree (MST) was reconstructed using these 6 loci, most strains clustered in the expected branches in the MST branches. However, topology of the MST was not congruent with the evolutional hypothesis of M. tuberculosis, indicating that MST analysis using VNTR data should not use for phylogeny of the organism. When the standardized index of association (sI(A)) was calculated using data for the 6 VNTR loci, the value of sI(A) was significantly different from zero (Monte Carlo simulation with 10,000 resamplings) in every lineage, indicating the linkage disequilibrium in different lineage strains of M. tuberculosis. These results were consistent with the hypothesis that clonal evolution of lineages of the organism has occurred. Therefore, the 6 loci identified in this study would be effective for M. tuberculosis population genetic analysis due to their significantly different median numbers of repeat and linkage disequilibrium though VNTR data was not effective for phylogeny of the organism., (Copyright 2010 Elsevier B.V. All rights reserved.)
- Published
- 2010
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224. Short-term effects of crossover treatment with silodosin and tamsulosin hydrochloride for lower urinary tract symptoms associated with benign prostatic hyperplasia.
- Author
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Miyakita H, Yokoyama E, Onodera Y, Utsunomiya T, Tokunaga M, Tojo T, Fujii N, and Yanada S
- Subjects
- Adrenergic alpha-Antagonists adverse effects, Aged, Cross-Over Studies, Humans, Indoles adverse effects, Male, Middle Aged, Prostatic Hyperplasia complications, Quality of Life, Sulfonamides adverse effects, Tamsulosin, Treatment Outcome, Urination Disorders etiology, Adrenergic alpha-Antagonists therapeutic use, Indoles therapeutic use, Prostatic Hyperplasia drug therapy, Sulfonamides therapeutic use, Urinary Tract physiopathology, Urination Disorders drug therapy
- Abstract
Objectives: To compare the efficacy and safety of silodosin and tamsulosin in patients with lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH) by a randomized crossover method., Methods: BPH patients with the complaint of LUTS were included in this study, and were randomly divided into two groups: a silodosin-preceding group (4 weeks of twice-daily administration of silodosin at 4 mg, followed by 4 weeks of once-daily administration of tamsulosin at 0.2 mg) or a tamsulosin-preceding group (4 weeks' administration of tamsulosin, followed by 4 weeks' administration of silodosin). No drug withdrawal period was provided when switching the drug., Results: In the first treatment period, both drugs significantly improved the International Prostate Symptom Score total score, but the improvement by silodosin was significantly superior to that by tamsulosin. After crossover treatment, significant improvement was observed only with silodosin treatment. Moreover, intergroup comparison of changes revealed that silodosin showed significant improvement of straining and nocturia with first and crossover treatments, respectively, compared with tamsulosin. Silodosin also significantly improved quality of life (QOL) score in both treatment periods, while tamsulosin significantly improved QOL score only in the first treatment period. The most frequent adverse drug reaction was ejaculatory disorder with silodosin; however, the incidence of dizziness with silodosin was similar to that with tamsulosin., Conclusions: In BPH/LUTS patients, silodosin exhibits excellent efficacy in improving subjective symptoms in both initial and crossover treatment, and it appears to improve the QOL of patients., (© 2010 The Japanese Urological Association.)
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- 2010
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225. Mutational analysis of reduced telithromycin susceptibility of Streptococcus pneumoniae isolated clinically in Japan.
- Author
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Takaya A, Kitagawa N, Kuroe Y, Endo K, Okazaki M, Yokoyama E, Wada A, and Yamamoto T
- Subjects
- DNA Fingerprinting, DNA Mutational Analysis, Electrophoresis, Gel, Pulsed-Field, Genes, Bacterial, Genotype, Japan, Macrolides pharmacology, Microbial Sensitivity Tests, Recombination, Genetic, Streptococcus pneumoniae classification, Streptococcus pneumoniae genetics, Streptococcus pneumoniae isolation & purification, Transformation, Bacterial, Anti-Bacterial Agents pharmacology, Drug Resistance, Bacterial, Ketolides pharmacology, Pneumococcal Infections microbiology, Streptococcus pneumoniae drug effects
- Abstract
A total of 132 Streptococcus pneumoniae isolates collected between 2005 and 2006 in Japan were examined for susceptibility to telithromycin (TEL) and macrolide. The overall resistance to macrolide was 80%. Among the isolates, 128 strains had low-level TEL susceptibility (minimal inhibitory concentrations [MICs] 0.03-1 microg mL(-1)), suggesting that pneumococci with reduced susceptibility to TEL have appeared without prior exposure to the drug, although none of the isolates were assigned as TEL-resistant (breakpoint, > or = 4 microg mL(-1)). Eight of these isolates (MIC 0.5-1 microg mL(-1)) were analyzed for macrolide resistance determinants and genetic relatedness. They all carried mefE-mel, which encodes the macrolide efflux genetic assembly, and three also harbored ermB, which encodes rRNA methylase. Allele replacement mutagenesis of the corresponding genes in the clinical isolates revealed that reduced TEL susceptibility (MIC 1 microg mL(-1)) in S. pneumoniae may be caused by acquisition of the mefE-mel element only and additionally conferred by the ermB determinant.
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- 2010
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226. [Molecular epidemiology of Mycobacterium tuberculosis reviewed by molecular epidemiology of other pathogenic bacteria].
- Author
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Yokoyama E
- Subjects
- Disease Outbreaks, Escherichia coli Infections microbiology, Humans, Minisatellite Repeats, Tuberculosis microbiology, Escherichia coli Infections epidemiology, Escherichia coli O157 genetics, Molecular Epidemiology trends, Mycobacterium tuberculosis genetics, Tuberculosis epidemiology
- Published
- 2009
227. [Clinical significance of risedronate for patients with prostate cancer receiving androgen deprivation therapy].
- Author
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Kimura M, Satoh T, Okazaki M, Tabata K, Tsuboi T, Hyodo T, Yokoyama E, Matsumoto K, Soh S, Iwamura M, Hayakawa K, and Bab S
- Subjects
- Aged, Androgen Antagonists therapeutic use, Bone Density, Etidronic Acid administration & dosage, Fractures, Bone etiology, Fractures, Bone prevention & control, Humans, Male, Middle Aged, Prospective Studies, Prostatic Neoplasms complications, Risedronic Acid, Androgen Antagonists adverse effects, Bone Density Conservation Agents administration & dosage, Etidronic Acid analogs & derivatives, Osteoporosis etiology, Osteoporosis prevention & control, Prostatic Neoplasms drug therapy
- Abstract
Purpose: Androgen deprivation therapy (ADT) in patients with prostate cancer is associated with bone loss. We investigated the effectiveness of risedronate about a decreasing bone mineral density in patients with prostate cancer on ADT., Material and Method: A prospective study was conducted in Kitasato University Hospital from April 2004 to October 2006. A total of 69 men with prostate cancer were assigned to receive either oral risedronate or none during ADT (hormone naïve). The treatment group was 58 men and taking 2.5 mg risedronate per day. The control group was 11 men. At baseline, we assessed BMD (bone mineral density) by DEXA and urinary NTX, and measured for these changes every 6 months., Result: At baseline, each BMDs had no significant difference at the lumber and total hip. At the first 6-month stage, the change in BMD percentage between the 2 groups was statistically significantly different at lumber (p = 0.002) and total hip (p = 0.038). At the 12-month stage, the change in the BMD percentage between the 2 groups was statistically significantly different at the lumber (p = 0.038). And each difference made out that the risedronate group was preserving BMD. In urinary NTX, bone turn over was statistically significantly decreased with the risedronate group compared with the control group at the 12-month stage (p = 0.017)., Conclusion: We assure the beginning of bone loss at an early date (6 months) with ADT. Daily oral risedronate in patients with receiving ADT reduces bone mineral loss and maintain BMD.
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- 2008
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228. Variable number of tandem repeats and pulsed-field gel electrophoresis cluster analysis of enterohemorrhagic Escherichia coli serovar O157 strains.
- Author
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Yokoyama E and Uchimura M
- Subjects
- Animals, Base Sequence, Cluster Analysis, Disease Outbreaks, Electrophoresis, Gel, Pulsed-Field methods, Escherichia coli Infections epidemiology, Escherichia coli Infections transmission, Escherichia coli O157 classification, Escherichia coli O157 metabolism, Food Microbiology, Gene Frequency, Humans, Japan, Minisatellite Repeats, Phylogeny, Polymerase Chain Reaction methods, DNA, Bacterial analysis, Escherichia coli O157 genetics, Shiga Toxins biosynthesis, Tandem Repeat Sequences
- Abstract
Ninety-five enterohemorrhagic Escherichia coli serovar O157 strains, including 30 strains isolated from 13 intrafamily outbreaks and 14 strains isolated from 3 mass outbreaks, were studied by pulsed-field gel electrophoresis (PFGE) and variable number of tandem repeats (VNTR) typing, and the resulting data were subjected to cluster analysis. Cluster analysis of the VNTR typing data revealed that 57 (60.0%) of 95 strains, including all epidemiologically linked strains, formed clusters with at least 95% similarity. Cluster analysis of the PFGE patterns revealed that 67 (70.5%) of 95 strains, including all but 1 of the epidemiologically linked strains, formed clusters with 90% similarity. The number of epidemiologically unlinked strains forming clusters was significantly less by VNTR cluster analysis than by PFGE cluster analysis. The congruence value between PFGE and VNTR cluster analysis was low and did not show an obvious correlation. With two-step cluster analysis, the number of clustered epidemiologically unlinked strains by PFGE cluster analysis that were divided by subsequent VNTR cluster analysis was significantly higher than the number by VNTR cluster analysis that were divided by subsequent PFGE cluster analysis. These results indicate that VNTR cluster analysis is more efficient than PFGE cluster analysis as an epidemiological tool to trace the transmission of enterohemorrhagic E. coli O157.
- Published
- 2007
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229. Improved molecular epidemiological analysis of Mycobacterium tuberculosis strains using multi-locus variable number of tandem repeats typing.
- Author
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Yokoyama E, Kishida K, and Ichinohe S
- Subjects
- Humans, Japan epidemiology, Molecular Epidemiology methods, Polymorphism, Restriction Fragment Length, Tuberculosis epidemiology, Minisatellite Repeats, Mycobacterium tuberculosis genetics, Tuberculosis microbiology
- Published
- 2007
230. Prevalence and genetic properties of Salmonella enterica serovar typhimurium definitive phage type 104 isolated from Rattus norvegicus and Rattus rattus house rats in Yokohama City, Japan.
- Author
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Yokoyama E, Maruyama S, Kabeya H, Hara S, Sata S, Kuroki T, and Yamamoto T
- Subjects
- Animals, Anti-Bacterial Agents pharmacology, Bacteriophage Typing, Cluster Analysis, DNA Fingerprinting, DNA, Bacterial genetics, Deoxyribonucleases, Type II Site-Specific metabolism, Drug Resistance, Bacterial genetics, Feces microbiology, Genes, Bacterial, Integrons, Japan, Microbial Sensitivity Tests, Molecular Epidemiology, Prevalence, Rodent Diseases epidemiology, Salmonella Infections, Animal epidemiology, Salmonella typhimurium classification, Salmonella typhimurium drug effects, Salmonella typhimurium genetics, Disease Reservoirs, Rats microbiology, Rodent Diseases microbiology, Salmonella Infections, Animal microbiology, Salmonella typhimurium isolation & purification
- Abstract
Salmonella enterica serovar Typhimurium was isolated from the intestinal contents of Rattus rattus and Rattus norvegicus house rats captured at two buildings, designated buildings J and YS, in Yokohama City, Japan. From October 1997 to September 1998, 52 of 339 (15.3%) house rats were found to carry Salmonella serovar Typhimurium definitive phage type 104 (DT104). In building J, 26 of 161 (16.1%) house rats carried DT104 over the 1-year study period, compared to 26 of 178 (14.6%) rats in building YS. The isolation rates of DT104 from R. rattus and R. norvegicus were similar in the two buildings. Most DT104 strains from building J (24 of 26) showed resistance to ampicillin, chloramphenicol, streptomycin, sulfisoxazole, and tetracycline and contained both the 1.0- and 1.2-kbp integrons, carrying genes pse1, pasppflo-like, aadA2, sulI, and tet(G). All DT104 strains from building YS were resistant to ampicillin and sulfisoxazole, and had the 1.2-kbp integron carrying pse1 and sulI. Cluster analysis of pulsed-field gel electrophoresis patterns of BlnI-digested DT104 DNAs showed that 22 of 26 DT104 strains from building J and 24 of 26 strains from building YS could be grouped into separate clusters each specific for the building origin. These results indicated that DT104 strains were prevalent in house rat colonies in each building and suggest that house rats may play an important role in the epidemiology of DT104.
- Published
- 2007
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231. [Molecular epidemiological analysis of an outbreak of Campylobacter jejuni using restriction enzyme double-digestion technique for genotyping of isolates by pulsed-field gel electrophoresis].
- Author
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Yoda K, Yokoyama E, and Uchimura M
- Subjects
- Campylobacter Infections epidemiology, Campylobacter jejuni genetics, Child, Disease Outbreaks, Electrophoresis, Gel, Pulsed-Field, Foodborne Diseases epidemiology, Gastroenteritis epidemiology, Gastroenteritis microbiology, Genotype, Humans, Japan epidemiology, Restriction Mapping, Campylobacter Infections microbiology, Campylobacter jejuni isolation & purification, Foodborne Diseases microbiology
- Abstract
In an outbreak of gastroenteritis in elementary school students and their families in Chiba Prefecture, Japan, Campylobacter jejuni was isolated from the stools of 14 patients who developed diarrheal illness after a one-day bus trip. C. jejuni was also isolated from the stools of 3 patients not going on the bus trip. Pulsed-field gel electrophoresis (PFGE) analysis was done on 17 isolates of C. jejuni to study genetic relationships among them. PFGE profiles of isolates treated with restriction enzymes Sma I, Ksp I and Kpn I were separated into 9, 10, and 10 types, but the relationship between PFGE profiles and epidemiological profiles was unclear. Dendrograms of PFGE of isolates double-digested with both Sma I and Ksp I were typed into D1, D2, D3 and D4, and profiles compared to profiles of serotyping and flagellin typing of isolates and epidemiological profiles to evaluate genetical and epidemiological relationships. Thirteen isolates of PFGE type D1 possessed serotype G and flagellin type Al and were isolated from patients going on the bus trip. Type D2 isolated from a student going on the bus trip and type D3 isolates from two students not going on the bus trip had serotype B and flagellin type A2. C. jejuni of PFGE type D4, serotype UT, and flagellin type A3 was also isolated from a student not going on the trip. Our results show that at least two outbreaks of C. jejuni occurred simultaneously in people related to the school. Restriction enzyme double-digestion PFGE was thus useful in the molecular epidemiological analysis of the C. jejuni outbreak.
- Published
- 2006
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232. Phylogenetic and structural analyses of the mating-type loci in Clavicipitaceae.
- Author
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Yokoyama E, Arakawa M, Yamagishi K, and Hara A
- Subjects
- Hypocreales genetics, Mycological Typing Techniques, Phylogeny, DNA, Fungal analysis, Genes, Mating Type, Fungal, Hypocreales classification
- Abstract
Entomopathogens and other econutritional fungi belonging to Clavicipitaceae were phylogenetically analyzed on the basis of the 18S rRNA gene and mating-type genes (MAT1-1-1 and MAT1-2-1). The phylogenies of the mating-type genes yielded better resolutions than that of 18S rRNA gene. Entomopathogens (Cordyceps bassiana, Cordyceps brongniartii, Cordyceps militaris, Cordyceps sinclairii, Cordyceps takaomontana, Isaria cateniannulata, Isaria farinosa, Isaria fumosorosea, Isaria javanica, Lecanicillium muscarium and Torrubiella flava) were considered as a phylogenetically defined group, and were closely related to mycopathogens (Lecanicillium psalliotae and Verticillium fungicola). They located at more descendant positions in the mating-type trees than other fungi, and lacked the mating-type gene MAT1-1-3. The deletion of MAT1-1-3 was supposed to have occurred once in Clavicipitaceae, and a good indication for the evolution of Clavicipitaceae. Other entomopathogens (Cordyceps cylindrica, Cordyceps subsessilis, Metarhizium anisopliae and Nomuraea rileyi) and pathogens of plants, nematodes and slime molds, were relatively related to each other, and possessed MAT1-1-3, but were supposed to be heterogeneous. Root-associated fungi did not form any clade with other species.
- Published
- 2006
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233. Entomogenous fungi that produce 2,6-pyridine dicarboxylic acid (dipicolinic acid).
- Author
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Watanabe N, Hattori M, Yokoyama E, Isomura S, Ujita M, and Hara A
- Subjects
- Animals, Cordyceps genetics, Insecta microbiology, Species Specificity, Cordyceps classification, Cordyceps metabolism, Picolinic Acids metabolism
- Abstract
An inhibitor of the prophenoloxidase activation using extract from a silkworm pupa was isolated from a culture filtrate of Cordyceps militaris and identified as dipicolinic acid (DPA). The production of DPA in Clavicipitaceae fungi was examined. Entomogenous fungi that produce DPA were integrated into one group by a phylogenetic analysis based on 18S rDNA. It is suggested that the group acquired an ability to produce DPA during its evolution from plant pathogenic fungi to entomogenous fungi.
- Published
- 2006
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234. Comparison between agarose gel electrophoresis and capillary electrophoresis for variable numbers of tandem repeat typing of Mycobacterium tuberculosis.
- Author
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Yokoyama E, Kishida K, Uchimura M, and Ichinohe S
- Subjects
- Cluster Analysis, Disease Outbreaks, Electrophoresis, Agar Gel, Electrophoresis, Capillary, Humans, Mycobacterium tuberculosis genetics, Polymorphism, Restriction Fragment Length, Tuberculosis, Pulmonary epidemiology, Tuberculosis, Pulmonary microbiology, Bacterial Typing Techniques, Minisatellite Repeats genetics, Mycobacterium tuberculosis classification
- Abstract
Variable numbers of tandem repeat (VNTR) typing of Mycobacterium tuberculosis was performed on 54 strains including 23 strains derived from 9 outbreaks. PCR amplicon sizes of 12 mycobacterial interspersed repetitive unit tandem repeat loci were measured using both agarose gel electrophoresis and capillary electrophoresis. Similarities using agarose gel electrophoresis of Euclidian distances among the 23 strains derived from the 9 outbreaks were significantly lower than that using capillary electrophoresis (Wilcoxon signed ranks test, P < 0.01). By clustering analysis using unweighted pair group method using arithmetic averages, all of the 23 strains derived from the 9 outbreaks were each clustered with more than 90% similarities based on the distance using capillary electrophoresis. In contrast, differential clusters with more than 90% similarity were observed with only 7 strains derived from 3 outbreaks when analyzed by agarose gel electrophoresis. These results indicated that measurement of PCR amplicon size of tandem repeat loci should be carried out using capillary electrophoresis and that agarose gel electrophoresis is not suitable for clustering analysis of M. tuberculosis VNTR typing.
- Published
- 2006
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235. Extracellular trypsin-like proteases produced by Cordyceps militaris.
- Author
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Hattori M, Isomura S, Yokoyama E, Ujita M, and Hara A
- Subjects
- Amino Acid Sequence, Animals, Enzyme Activation, Extracellular Fluid enzymology, Molecular Sequence Data, Peptide Hydrolases biosynthesis, Peptide Hydrolases chemistry, Peptide Hydrolases isolation & purification, Sequence Homology, Amino Acid, Substrate Specificity, Trypsin isolation & purification, Cordyceps enzymology, Diptera microbiology, Trypsin biosynthesis, Trypsin chemistry
- Abstract
A trypsin-like protease, P-1-1, was purified from the culture supernatant of the fungus Cordyceps militaris by (NH(4))(2)SO(4) precipitation, chromatography on DEAE Bio-Gel Agarose, TSKgel CM-5PW, and gel-filtration with HiLoad 26/60 Superdex 75 pg, and its properties were examined. Purified P-1-1 showed a single band by SDS-PAGE and was estimated to have a molecular mass of 23,405 by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The optimum pH of the enzyme was between 8.5 and 12.0. It was inhibited strongly by leupeptin and diisopropyl fluorophosphate (DFP), and definitely did by N(alpha)-tosyl-L-lysine chloromethyl ketone hydrochloride (TLCK), phenylmethanesulfonyl fluoride (PMSF) and chymostatin. The carbonyl group sides of Arg and Lys were confirmed as the sites of cleavage by the enzyme toward cecropin B. These results indicate that P-1-1 is a trypsin-type serine protease. The N-terminal amino acid sequence of P-1-1 showed a high homology with those of trypsins or chymotrypsin derived from Diptera insects.
- Published
- 2005
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236. [Cluster analysis of restriction fragment length polymorphism patterns of Mycobacterium tuberculosis isolated in Chiba prefecture].
- Author
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Kishida K, Yokoyama E, Uchimura M, and Ichinohe S
- Subjects
- Cluster Analysis, Electrophoresis, Humans, Japan epidemiology, Mycobacterium tuberculosis isolation & purification, Tuberculosis epidemiology, Molecular Epidemiology, Mycobacterium tuberculosis genetics, Polymorphism, Restriction Fragment Length
- Abstract
Methods for cluster analysis of IS6110 based restriction fragment length polymorphism (RFLP) patterns of Mycobacterium tuberculosis isolates were studied for an epidemiological investigation in Chiba prefecture. To normalize patterns, external size markers were adopted instead of typical internal size markers used in the standard method. RFLP patterns were run on 1.4% agarose gels and external markers were applied to outside and middle lanes on each gel for precise comparison. The resulting RFLP patterns of 74 isolates were clustered by similarity. Similarity was calculated with the Dice coefficient using parameter settings at 0.8% tolerance and 0.5% optimization. Patterns of 19 isolates from 8 outbreaks showed high similarity within each outbreak. Cluster analysis, as described here, provides insights into epidemiological tracing of tuberculosis in Chiba prefecture.
- Published
- 2005
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237. The marked increase of Listeria monocytogenes isolation from contents of swine cecum.
- Author
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Yokoyama E, Saitoh T, Maruyama S, and Katsube Y
- Subjects
- Animals, Cecum microbiology, Culture Media, DNA, Bacterial chemistry, DNA, Bacterial genetics, Feces microbiology, Gastrointestinal Diseases microbiology, Hydrogen-Ion Concentration, Listeria monocytogenes genetics, Listeria monocytogenes isolation & purification, Listeriosis epidemiology, Listeriosis microbiology, Prevalence, Random Amplified Polymorphic DNA Technique veterinary, Serotyping veterinary, Swine, Swine Diseases epidemiology, Gastrointestinal Diseases veterinary, Listeria monocytogenes growth & development, Listeriosis veterinary, Swine Diseases microbiology
- Abstract
The actual prevalence of Listeria monocytogenes from contents of swine cecum was investigated. The efficiency of Listeria enrichment broth (LEB) for isolation was examined by the recovery of artificially inoculated L. monocytogenes in contents of swine cecum. The numbers of organisms did not increase after 48 h incubation, but increased when the rapid decrease in pH of the LEB was adjusted. Between 1991 and 1993, 250 contents of swine cecum were examined for the prevalence of L. monocytogenes using LEB enrichment, either with or without pH adjustment. L. monocytogenes was isolated from 74 samples in 1993 with pH adjustment, however, no organisms were isolated in 1991 and 1992. It was suggested that the marked rise of the L. monocytogenes isolation was due to the spread of the organism among swine. Furthermore, 67 out of the 74 isolates were identified as 1/2c by serotyping. The serovar 1/2c strains showed genetic diversity by random amplified polymorphic DNA.
- Published
- 2005
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238. [Comparison between biotype of Vibrio cholerae O1 and genotype using polymerase chain reaction].
- Author
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Yokoyama E, Koiwai K, and Uchimura M
- Subjects
- Bacterial Typing Techniques, Genotype, Hemolytic Plaque Technique, Vibrio cholerae O1 classification, Polymerase Chain Reaction, Vibrio cholerae O1 genetics
- Abstract
To compare between biotype of Vibrio cholerae O1 and genotype using polymerase chain reaction (PCR), 9 classical and 81 El Tor biovar strains were investigated for hemolysis, agglutination of avian erythrocytes, VP test reactivity, sensitivity to both polymyxin B and classical phage IV, and genotype using PCR amplification of hlyA, tcpA, rtxA and rtxC. One classical biovar strain showed atypical reaction upon agglutination of avian erythrocytes. Eighteen El Tor biovar strains showed atypical reactions, with the exception of sensitivity to polymyxin B. By PCR detection of hlyA, rtxA and rtxC amplifications, all classical biovar strains possessed only classical type hlyA, while all El Tor biovar strains possessed El Tor type hlyA, rtxA and rtxC. By PCR analysis of amplicons, all classical biovar strains possessed classical type tcpA. One ctx-negative El Tor biovar strain possessed degenerated classical type tcpA and 4 ctx-negative El Tor biovar strains had no detectable tcpA. These results indicated that genotype of V. cholerae O1 using PCR detection of hlyA, rtxA and rtxC was consistent with biotype of the organism, suggesting that analysis of the genotype of the organism was as effective as by biochemical properties. However, PCR detection of hlyA is most appropriate for the biotyping of V. cholerae O1, as compared to biochemical properties, since El Tor biovar was originally distinguished from classical biovar strains by the hemolytic reaction.
- Published
- 2005
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239. Influence of bacteriocin-like substance, generation times, and genetic profiles of Listeria innocua on the isolation of Listeria monocytogenes.
- Author
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Yokoyama E, Shibusawa Y, Maruyama S, Katsube Y, and Mikami T
- Subjects
- Bacteriocins metabolism, Colony Count, Microbial, DNA, Bacterial chemistry, DNA, Bacterial genetics, Listeria monocytogenes genetics, Listeria monocytogenes growth & development, Listeria monocytogenes metabolism, Random Amplified Polymorphic DNA Technique, Bacteriocins biosynthesis, Food Microbiology, Listeria monocytogenes isolation & purification
- Abstract
Inhibition of isolation of Listeria monocytogenes by bacteriocin-like substance (BLS)-producing Listeria innocua after enrichment culture was investigated. When 26 L. monocytogenes strains were examined in combination with eight L. innocua strains using the spot on lawn method, 52/208 (25.0%) combinations showed the growth inhibition of L. monocytogenes. When two Listeria species were cultured simultaneously in selective enrichment broth, inhibition of isolation of L. monocytogenes was observed in 12/52 of the combinations at 24h (23.1%), in 24/52 at 48h (46.2%) and in 30/52 (57.7%) after 7 days of incubation. The randomly amplified polymorphic DNA profiles showed no interstrain similarities between either strains of the BLS-producing L. innocua or the BLS-sensitive L. monocytogenes strains. Therefore inhibition by BLS-producing L. innocua of isolation of L. monocytogenes after enrichment culture is unlikely to be dependent upon a particular genetic profile.
- Published
- 2005
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240. Permeability of mouse oocytes and embryos at various developmental stages to five cryoprotectants.
- Author
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Pedro PB, Yokoyama E, Zhu SE, Yoshida N, Valdez DM Jr, Tanaka M, Edashige K, and Kasai M
- Subjects
- Acetamides pharmacokinetics, Animals, Blastocyst drug effects, Blastocyst metabolism, Blastomeres drug effects, Cell Membrane Permeability, Cell Size drug effects, Embryonic Development drug effects, Embryonic Development physiology, Ethylene Glycol pharmacokinetics, Female, Metaphase, Mice, Mice, Inbred ICR, Micromanipulation instrumentation, Morula drug effects, Oocytes drug effects, Propylene Glycol pharmacokinetics, Blastomeres metabolism, Cryopreservation methods, Cryoprotective Agents pharmacokinetics, Dimethyl Sulfoxide pharmacokinetics, Morula metabolism, Oocytes metabolism
- Abstract
To assess the permeability of mouse oocytes and embryos, matured oocytes and embryos at various stages of development were placed in five cryoprotectant solutions at 25 C for 25 min. From the cross-sectional areas of the oocytes/embryos, the relative change in volume was analyzed. In oocytes, shrinkage was least extensive and recovery was quickest in the propylene glycol solution, showing that propylene glycol permeates the oocytes most rapidly. Dimethyl sulfoxide, acetamide, and ethylene glycol permeated the oocytes slightly more slowly than propylene glycol. The oocytes in glycerol shrunk extensively and then expanded marginally, indicating slow permeation. The volume changes of 1-cell and 2-cell embryos were similar to those of oocytes, showing little change in permeability. In 8-cell embryos, the volume recovered much faster than in the earlier stages especially in glycerol and acetamide. In morulae, the volume recovery was much faster in glycerol and in ethylene glycol; in ethylene glycol, the extent of shrinkage was small and the recovery was fast, indicating an extremely rapid permeation. Although the permeability of oocytes/embryos generally increased as embryo development proceeded, the degree of increase varied greatly among the cryoprotectants. Interestingly, the volume change in propylene glycol was virtually unaffected by the stage of development. Such information will be valuable for determining a suitable protocol for the cryopreservation of oocytes/embryos at different stages of development.
- Published
- 2005
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241. [Isolation of Listeria monocytogenes from a patient with sealed ruptured thoracoabdominal aortic aneurysm].
- Author
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Yokoyama E, Tsuruoka S, Saitou Y, and Ichinohe S
- Subjects
- Aged, Humans, Male, Aortic Aneurysm, Abdominal microbiology, Aortic Aneurysm, Thoracic microbiology, Aortic Rupture microbiology, Listeria monocytogenes isolation & purification
- Abstract
We are reporting a case of sealed rupture of thoracoabdominal aortic aneurysm associated with the isolation of Listeria monocytogenes. The patient was a 75-year-old man with previous history of hypertension that had not required medication for the 3 years prior to hospital admission. He was admitted due to chest pain, but he was afebrile. There were no clinical findings indicating infection, although CRP was slightly elevated. During his clinical course, a sealed rupture of a thoracoabdominal aortic aneurysm was found and replaced with an artificial artery. After surgery, he was treated for 2 weeks with sultamicillin. He was discharged from hospital on the 43rd postoperative day. No bacteria were observed after microscopic examination of gram stained samples from the thrombus that was present in the sealed rupture of the aneurysm. However, a L. monocytogenes strain isolated from the thrombus only after enrichment culturing by HK medium at 37 degrees C for 4 days. By histopathology, there was a slight cellular infiltration of lymphocytes and neutrophils at the aperture of the aneurysm. Although L. monocytogenes strains possess major pathogenic genes, such as prfA, hlyA, plcA, plcB, mpl, inlA, inlB and actA that can be identified by PCR, none of the evidence indicated that this case was a mycotic aortic aneurysm due to L. monocytogenes.
- Published
- 2004
- Full Text
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242. Development of a PCR-based mating-type assay for Clavicipitaceae.
- Author
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Yokoyama E, Yamagishi K, and Hara A
- Subjects
- DNA Primers, DNA, Fungal classification, Fungal Proteins classification, Fungal Proteins genetics, Genotype, Hypocreales classification, Molecular Sequence Data, Phylogeny, RNA, Ribosomal, 18S genetics, Genes, Fungal, Genes, Mating Type, Fungal, Hypocreales genetics, Polymerase Chain Reaction methods
- Abstract
This study developed a PCR-based mating-type assay for Clavicipitaceae. PCR primer sets for the mating-type genes MAT1-1-1 and MAT1-2-1 were designed based on the amino acid sequences of the conserved alpha and HMG boxes, respectively. The PCR-based mating-type assay could be applied for various clavicipitaceous genera (Balansia, Claviceps, Cordyceps and Epichloë). Most of the clavicipitaceous fungi possessed either MAT1-1-1 or MAT1-2-1, and were supposed to be heterothallic. Although the PCR products obtained by the mating-type assay were short, the phylogenetic trees of the mating-type genes gave better resolutions than that of 18S rDNA and agreed well to their econutritional modes.
- Published
- 2004
- Full Text
- View/download PDF
243. Weekly paclitaxel plus estramustine combination therapy in hormone-refractory prostate cancer: a pilot study.
- Author
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Kuruma H, Fujita T, Shitara T, Egawa S, Yokoyama E, and Baba S
- Subjects
- Adenocarcinoma mortality, Administration, Oral, Aged, Aged, 80 and over, Antineoplastic Agents, Hormonal administration & dosage, Antineoplastic Agents, Hormonal adverse effects, Antineoplastic Agents, Phytogenic administration & dosage, Antineoplastic Agents, Phytogenic adverse effects, Antineoplastic Combined Chemotherapy Protocols adverse effects, Bone Neoplasms complications, Bone Neoplasms secondary, Drug Administration Schedule, Estramustine administration & dosage, Estramustine adverse effects, Humans, Infusions, Intravenous, Lymphatic Metastasis, Male, Middle Aged, Paclitaxel administration & dosage, Paclitaxel adverse effects, Pain drug therapy, Pain etiology, Pilot Projects, Prospective Studies, Prostate-Specific Antigen blood, Prostatic Neoplasms mortality, Treatment Outcome, Adenocarcinoma drug therapy, Antineoplastic Combined Chemotherapy Protocols administration & dosage, Prostatic Neoplasms drug therapy
- Abstract
Background: Paclitaxel used in combination with estramustine has been shown to exert synergistic cytotoxicity in patients with hormone-refractory prostate cancer (HRPC). There have been few reports of this therapy in an Asian male population., Methods: Nine patients with progressive metastatic HRPC completed at least one cycle of combination therapy employing weekly paclitaxel plus estramustine. Paclitaxel was given weekly for 3 weeks as a 2-h intravenous infusion at a dose of 100 mg/infusion. The cycle was repeated every 4 weeks. A dose of 280 mg of oral estramustine was administrated twice daily for 21 days from the first day of each cycle. Both efficacy and toxicity were recorded., Results: Grade 1 sensory neuropathy was seen in three patients (33%) and grade 4 thrombopenia/anemia was seen in one patient (11%). Performance status improved in three of seven patients (43%), while six patients (67%) showed a 50% or greater decline in prostate-specific antigen levels. Two of these patients experienced significant improvement in bone pain. One patient died of cardiac infarction during this trial and another died of disseminated intravascular coagulopathy subsequent to gastrointestinal bleeding. An additional patient suffered non-fatal pulmonary infarction. The one-year median survival rate was 22.2% and the overall survival period was 36 weeks., Conclusion: Although weekly paclitaxel plus estramustine may pose a significant risk, this combination may have a beneficial effect on the quality of life HRPC patients. A well-designed phase I-II trial in an Asian male population is highly recommended.
- Published
- 2003
- Full Text
- View/download PDF
244. Structures of the mating-type loci of Cordyceps takaomontana.
- Author
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Yokoyama E, Yamagishi K, and Hara A
- Subjects
- Base Sequence, Cordyceps physiology, Molecular Sequence Data, Polymerase Chain Reaction, Chromosome Mapping, Cordyceps genetics
- Abstract
Nucleotide sequences of the mating-type loci MAT1-1 and MAT1-2 of Cordyceps takaomontana were determined, which is the first such report for the clavicipitaceous fungi. MAT1-1 contains two mating-type genes, MAT1-1-1 and MAT1-1-2, but MAT1-1-3 could not be found. On the other hand, MAT1-2 has MAT1-2-1. A pseudogene of MAT1-1-1 is located next to MAT1-2.
- Published
- 2003
- Full Text
- View/download PDF
245. Xylosidases associated with the cell surface of Penicillium herquei IFO 4674.
- Author
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Ito T, Yokoyama E, Sato H, Ujita M, Funaguma T, Furukawa K, and Hara A
- Abstract
Penicillium herquei IFO 4674 is a filamentous fungus that produces a large amount of hydrolases for fibrous polysaccharides. We purified two beta-xylosidases, S1 and S2. The molecular masses of S1 and S2 determined by MALDI-TOF-MS were 103,700 and 37,460 Da. The optimum pHs of S1 and S2 were 4.0 and 6.5, respectively. By several kinds of alcohols, especially glycerol, S1 was activated while S2 was unaffected or inhibited. S1 had a transxylosylation activity, while S2 did not. The s2 gene encoding xylosidase S2 was cloned by PCR with primers designed on the basis of partial amino acid sequences of S2. The s2 consisted of 1005 by encoding 335 amino acids (37,433 Da) and had no secretion signal sequence. The deduced amino acid sequence shows a high identity to that of Bacteroides ovatus xylosidase/arabinosidase (56%), which is a member of the family 43 glycoside hydrolase.
- Published
- 2003
- Full Text
- View/download PDF
246. Group-I intron containing a putative homing endonuclease gene in the small subunit ribosomal DNA of Beauveria bassiana IFO 31676.
- Author
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Yokoyama E, Yamagishi K, and Hara A
- Subjects
- Amino Acid Sequence, Base Sequence, Endonucleases chemistry, Molecular Sequence Data, Phylogeny, DNA, Fungal genetics, DNA, Ribosomal genetics, Endonucleases genetics, Fungi enzymology, Fungi genetics, Introns genetics
- Published
- 2002
- Full Text
- View/download PDF
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