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116 results on '"Murayama, Somay Yamagata"'

3. Comparison Approach for Identifying Missed Invasive Fungal Infections in Formalin-Fixed, Paraffin-Embedded Autopsy Specimens

Author

Sadamoto, Sota, primary, Mitsui, Yurika, additional, Nihonyanagi, Yasuhiro, additional, Amemiya, Kazuki, additional, Shinozaki, Minoru, additional, Murayama, Somay Yamagata, additional, Abe, Masahiro, additional, Umeyama, Takashi, additional, Tochigi, Naobumi, additional, Miyazaki, Yoshitsugu, additional, and Shibuya, Kazutoshi, additional

Published
2022
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7. Construction and functional analysis of fatty acid desaturase gene disruptants in Candida albicans

Author

Murayama, Somay Yamagata, Negishi, Yumiko, Umeyama, Takashi, Kaneko, Aki, Oura, Takahiro, Niimi, Masakazu, Ubukata, Kimiko, and Kajiwara, Susumu

Subjects
Candida albicans -- Genetic aspects, Genetic code -- Research, Unsaturated fatty acids -- Research, Genetic research, Biological sciences
Abstract

Polyunsaturated fatty acids (PUFAs), including linoleic acid (C18:2) and [alpha]-linolenic acid (C18:3), are major components of membranes. PUFAs are produced from monounsaturated fatty acids by several fatty acid desaturases (FADs) in many fungi, but Saccharomyces cerevisiae, Schizosaccharomyces pombe and humans do not have these enzymes. Although the fungal pathogen Candida albicans produces C18:2 and C18:3, the enzymes that synthesize them have not yet been investigated. In this report, two ORFs, CaFAD2 and CaFAD3, were identified based on their homology to other yeast FADs, and CaFAD2 and CaFAD3 gene disruptants were constructed. Cafad2[DELTA] and Cafad3A lost their ability to produce C18:2 and C18:3, respectively. Furthermore, S. cerevisiae cells expressing CaFad2p converted palmitoleic acid (C16:1) and C18:1 to hexadecadienoic acid (C16:2) and C18:2, respectively, and CaFad3p-expressing cells converted C18:2 to C18:3. These results strongly supported that CaFAD2 encodes the [DELTA]12 FAD and that CaFAD3 encodes the [omega]3 FAD. However, phenotypic analysis demonstrated that the presence of these PUFAs did not affect the virulence to mice, or morphogenesis in the culture media used to induce morphological change of C. albicans.

Published
2006

15. Mouse Models for Assessing the Protective Efficacy ofLactobacillus gasseriSBT2055 againstHelicobacter suisInfection Associated with the Development of Gastric Mucosa-Associated Lymphoid Tissue Lymphoma

Author

Matsui, Hidenori, primary, Takahashi, Tetsufumi, additional, Øverby, Anders, additional, Murayama, Somay Yamagata, additional, Yoshida, Haruno, additional, Yamamoto, Yuji, additional, Nishiyama, Keita, additional, Seto, Yasuyuki, additional, Takahashi, Takashi, additional, Mukai, Takao, additional, and Nakamura, Masahiko, additional

Published
2015
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17. Histopathological Evaluation of the Efficacy of Antifungals for Experimental Trichosporon Bloodstream Infection

Author

Sasai, Daisuke, primary, Okubo, Yoichiro, additional, Ishiwatari, Takao, additional, Sugita, Takashi, additional, Kaneko, Takehiko, additional, Murayama, Somay Yamagata, additional, Shimamura, Tsuyoshi, additional, Shinozaki, Minoru, additional, Hasegawa, Chikako, additional, Mitsuda, Aki, additional, Tochigi, Naobumi, additional, Wakayama, Megumi, additional, Nemoto, Tetsuo, additional, and Shibuya, Kazutoshi, additional

Published
2013
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18. Development of a Peptide Nucleic Acid Probe to Trichosporon Species and Identification of Trichosporonosis by Use of In Situ Hybridization in Formalin-Fixed and Paraffin-Embedded (FFPE) Sections

Author

Shinozaki, Minoru, primary, Okubo, Yoichiro, additional, Sasai, Daisuke, additional, Nakayama, Haruo, additional, Murayama, Somay Yamagata, additional, Ide, Tadashi, additional, Wakayama, Megumi, additional, Ishiwatari, Takao, additional, Tochigi, Naobumi, additional, Nemoto, Tetsuo, additional, and Shibuya, Kazutoshi, additional

Published
2013
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29. Microcirculatory alteration in low-grade gastric mucosa-associated lymphoma byHelicobacter heilmanniiinfection: Its relation to vascular endothelial growth factor and cyclooxygenase-2

Author

Nakamura, Masahiko, primary, Takahashi, Shinichi, additional, Matsui, Hidenori, additional, Murayama, Somay Yamagata, additional, Aikawa, Chihiro, additional, Sekiya, Yukie, additional, Nishikawa, Kaori, additional, Matsumoto, Tsukasa, additional, Yamada, Haruki, additional, and Tsuchimoto, Kanji, additional

Published
2008
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33. “ Candidatus Helicobacter heilmannii” from a Cynomolgus Monkey Induces Gastric Mucosa-Associated Lymphoid Tissue Lymphomas in C57BL/6 Mice

Author

Nakamura, Masahiko, primary, Murayama, Somay Yamagata, additional, Serizawa, Hiroshi, additional, Sekiya, Yukie, additional, Eguchi, Masahiro, additional, Takahashi, Shinichi, additional, Nishikawa, Kaori, additional, Takahashi, Tetsufumi, additional, Matsumoto, Tsukasa, additional, Yamada, Haruki, additional, Hibi, Toshifumi, additional, Tsuchimoto, Kanji, additional, and Matsui, Hidenori, additional

Published
2007
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42. Molecular epidemiologic characteristics of Streptococcus pneumoniae isolates from children with meningitis in Japan from 2007 through 2009.

Author

Sakai, Fuminori, Chiba, Naoko, Ono, Akiko, Murayama, Somay Yamagata, Ubukata, Kimiko, Sunakawa, Keisuke, and Takahashi, Takashi

Subjects
STREPTOCOCCUS pneumoniae, PENICILLIN, MENINGITIS, CEREBROSPINAL fluid, ANTIBIOTICS
Abstract

We examined associations of serotypes with multilocus sequence typing (MLST) data for 7 housekeeping genes and the genotype concerning penicillin resistance based on penicillin-binding protein (PBP) alterations in Streptococcus pneumoniae isolates from children with meningitis. From throughout Japan, we collected 115 pneumococcal isolates from the cerebrospinal fluid of patients 15 years old or younger from January 2007 to December 2009. We then carried out serotyping, MLST, and genotypic classification. Isolates included 24 serotypes and 52 sequence types (STs) according to MLST, of which 18 were novel. The 4 predominant serotypes included a variety of STs: 14 STs in serotype 6B ( n = 24), 2 STs in 19F ( n = 17), 6 STs in 23F ( n = 14), and 5 STs in 14 ( n = 11). Resistance genotypes included 6 types: 44.3% for gPRSP ( pbp1a + 2x + 2b), 13.9% for gPISP ( pbp1a + 2x), 9.6% for gPISP ( pbp2x + 2b), 19.1% for gPISP ( pbp2x), 3.5% for gPISP ( pbp2b), and 9.6% for gPSSP. Interestingly, the most prevalent serotype of 6B included 7 newly identified STs and a variety of genotypes for resistance. STs in serotypes 23F and 14 were highly diverse, but not in 19F. These results suggest that various genetic elements in S. pneumoniae might be intrinsically susceptible to genetic mutations and recombination, with acceleration of emergence reflecting selection pressures such as antibiotic overuse. [ABSTRACT FROM AUTHOR]

Published
2011
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43. Increased apoptosis and angiogenesis in gastric low-grade mucosa-associated lymphoid tissue-type lymphoma by Helicobacter heilmannii infection in C57/BL6 mice.

Author

Nishikawa, Kaori, Nakamura, Masahiko, Takahashi, Shinichi, Matsui, Hidenori, Murayama, Somay Yamagata, Matsumoto, Tsukasa, Yamada, Haruki, and Tsuchimoto, Kanji

Subjects
APOPTOSIS, NEOVASCULARIZATION, GASTRIC mucosa, HELICOBACTER diseases, LABORATORY mice, IMMUNOHISTOCHEMISTRY
Abstract

Helicobacter heilmannii has been reported to cause gastric low-grade mucosa-associated lymphoid tissue-type (MALT) lymphoma, but its precise pathophysiological mechanism remains to be clarified. We recently established a model of gastric B-cell MALT lymphoma in C57BL/6 mice by means of peroral infection of H. heilmannii primarily obtained from cynomolgus monkeys. Using this model, macroscopic, immunohistochemical, and electron microscopic observations of MALT lymphomas were carried out in order to examine the development of apoptosis and angiogenesis. Enhancement of the microvascular network and an increase in vascular endothelial growth factor-A were detected in the central region of the MALT lymphoma tissue in the infected mouse stomach, while vascular endothelial growth factor-C was detected at the margins of the MALT lymphomas. In addition, many H. heilmannii-invaded parietal cells showed caspase-3 immunoreactivity in the fundic mucosal tissue surrounding the MALT lymphoma. In conclusion, in H. heilmannii-induced MALT lymphoma, enhanced immunoreactivity of vascular endothelial growth factor-A and factor-C was observed in areas encircled by increased parietal cell apoptosis, which indicates the pathophysiological relevance of both angiogenesis and apoptosis in MALT lymphoma formation. [ABSTRACT FROM AUTHOR]

Published
2007
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44. Development of a Peptide Nucleic Acid Probe to TrichosporonSpecies and Identification of Trichosporonosis by Use of In SituHybridization in Formalin-Fixed and Paraffin-Embedded (FFPE) Sections

Author

Shinozaki, Minoru, Okubo, Yoichiro, Sasai, Daisuke, Nakayama, Haruo, Murayama, Somay Yamagata, Ide, Tadashi, Wakayama, Megumi, Ishiwatari, Takao, Tochigi, Naobumi, Nemoto, Tetsuo, and Shibuya, Kazutoshi

Abstract

ABSTRACTIn order to identify Trichosporonspecies in formalin-fixed and paraffin-embedded sections from which visual discrimination of non-glabrata Candidaspecies is mostly ineffective but critical for the choice of antifungals, we tested the usefulness of a newly designed peptide nucleic acid probe (PNA) for in situhybridization (ISH). Results confirmed the usefulness of ISH with our PNA probe in identifying Trichosporonspecies from Candida albicans.

Published
2013
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45. Confirmatory diagnosis of invasive maxillary sinus aspergillosis by in situhybridization: Report of two cases in immunocompetent subjects

Author

Kiriyama, Takeshi, Murayama, Somay Yamagata, and Myoken, Yoshinari

Abstract

Invasive maxillary sinus aspergillosis (IMSA) is uncommon in immunocompetent patients. The infection could become life-threatening due to delayed or mistaken diagnosis as it may extend into the orbit and brain. Two cases of invasive maxillary sinusitis caused by Aspergillusare described in apparently healthy subjects. Identification of the causative fungi as Aspergillusspecies was established by in situhybridization of tissue samples, even though the culturing of tissue samples failed to isolate Aspergillusspecies. Surgical debridement of the infected sinus tissue and antifungal therapy with itraconazole resulted in a favorable outcome. For prompt and accurate diagnosis of IMSA, we highlight the usefulness of a new molecular diagnostic method, i.e., in situhybridization in tissue samples.

Published
2012
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46. Identification of FusariumSpecies in Formalin-Fixed and Paraffin-Embedded Sections by In SituHybridization Using Peptide Nucleic Acid Probes

Author

Shinozaki, Minoru, Okubo, Yoichiro, Sasai, Daisuke, Nakayama, Haruo, Murayama, Somay Yamagata, Ide, Tadashi, Wakayama, Megumi, Hiruta, Nobuyuki, and Shibuya, Kazutoshi

Abstract

ABSTRACTFusariumhas recently emerged as an opportunistic pathogen of humans, but the histological differentiation of Fusariumfrom Aspergillusand Scedosporiumis particularly difficult because these fungi may induce similar clinical features and exhibit filamentous development in host tissues. Thus, there is a need to establish rapid and reliable methods that are applicable to pathological diagnoses. The aim of this study was to evaluate and establish in situhybridization (ISH) using peptide nucleic acid (PNA) probes targeting the 28S rRNA to identify Fusariumspecies in tissue sections. This technique was validated using both formalin-fixed and paraffin-embedded pulmonary tissues from mice infected with seven different species of fungi and cell blocks from fungal cultures of 30 strains. As a result, strong positive signals were observed within fungal organisms present in tissues of the lung from mice infected with Fusarium solani. Furthermore, this probe reacted strongly with both F. solaniand Fusarium oxysporumin sections from cell blocks. Although some cross-reactivity occurred with the Pseudallescheria boydiiin sections from cell blocks, the signal intensity was low and most hyphae were not reactive. In conclusion, it was confirmed that ISH with PNA probes is accurate and is a valuable tool for identifying Fusariumspp. among organisms that have identical morphological features in formalin-fixed and paraffin-embedded sections.

Published
2011
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47. Capsular Type and Antibiotic Resistance in Streptococcus agalactiaeIsolates from Patients, Ranging from Newborns to the Elderly, with Invasive Infections

Author

Murayama, Somay Yamagata, Seki, Chizuko, Sakata, Hiroshi, Sunaoshi, Katsuhiko, Nakayama, Eiichi, Iwata, Satoshi, Sunakawa, Keisuke, and Ubukata, Kimiko

Abstract

ABSTRACTStreptococcus agalactiaeisolates (n= 189) from patients with invasive infections were analyzed for capsular type by PCR, for antimicrobial susceptibility, and for the presence of resistance genes. In contrast to the predominance of capsular type III in children, types Ib and V were most common among adults. All 45 levofloxacin-resistant strains had two amino acid substitutions, Ser81Leu in the gyrAgene and Ser79Phe in the parCgene, and showed similar pulsed-field gel electrophoresis patterns.

Published
2009
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48. “CandidatusHelicobacter heilmannii” from a Cynomolgus Monkey Induces Gastric Mucosa-Associated Lymphoid Tissue Lymphomas in C57BL/6 Mice

Author

Nakamura, Masahiko, Murayama, Somay Yamagata, Serizawa, Hiroshi, Sekiya, Yukie, Eguchi, Masahiro, Takahashi, Shinichi, Nishikawa, Kaori, Takahashi, Tetsufumi, Matsumoto, Tsukasa, Yamada, Haruki, Hibi, Toshifumi, Tsuchimoto, Kanji, and Matsui, Hidenori

Abstract

ABSTRACTBoth Helicobacter pyloriand “CandidatusHelicobacter heilmannii” infections are associated with peptic ulcers, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue (MALT) lymphomas. However, good animal models of H. pyloriclinical diseases are rare. In this study, we aimed to establish an animal model of “CandidatusHelicobacter heilmannii” gastric MALT lymphoma. We used a urease-positive gastric mucosal and mucus homogenate from a cynomolgus monkey maintained in C57BL/6 mouse stomachs. The bacterium in the homogenate was identified as “CandidatusHelicobacter heilmannii” based on a DNA sequence analysis of the 16S rRNA and urease genes. Mucosal and mucus homogenates were used to inoculate C57BL/6 mice, which were then examined for 24 months. We observed a gradual increase in the surface area of protrusive lesions in almost all infected C57BL/6 mouse fundic stomachs 6 months after infection. Light microscopic observations revealed an accumulation of B lymphocytes along with destruction of glandular elements and the presence of lymphoepithelial lesions consistent with low-grade MALT lymphomas. Electron microscopic observation revealed numerous “CandidatusHelicobacter heilmannii” bacilli in the fundic glandular lumen, the intracellular canaliculi, and the cytoplasm of intact cells, as well as damaged parietal cells. In conclusion, “CandidatusHelicobacter heilmannii” induced gastric MALT lymphomas in almost 100% of infected C57BL/6 mice after a 6-month period associated with the destruction of parietal cells.

Published
2007
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49. cDNA Cloning of an Aspartic Proteinase Secreted by Candida albicans

Author

Mukai, Hiroyuki, Takeda, Osamu, Asada, Kiyozo, Kato, Ikunoshin, Murayama, Somay Yamagata, and Yamaguchi, Hideyo

Abstract

cDNA of an aspartic proteinase secreted by Candida albicansNo. 114 was isolated using the polymerase chain reaction (PCR). The primary structure of the enzyme was deduced from the nucleotide sequence of the cDNA and compared with the structures of Saccharomyces cerevisiaeproteinase A and vacuolar aspartyl proteinase of C. albicans. The mature aspartic proteinase consisted of 341 amino acid residues, and was 17.6 and 15.3% identical with the proteinase A and the aspartyl proteinase, respectively. Two active aspartic acid sites and the amino acids near those sites were conserved in the aspartic proteinase. We also showed that there is another gene of aspartic proteinase than that of strain ATCC10231 reported by Hube et al (J. Med. Vet. Mycol. 29 (1991)) in the same C. albicansgenome, both in that strain and in No. 114.

Published
1992
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50. Comparison of Secretory Acid Proteinases from Candida tropicalis, C. parapsilosisand C. albicans

Author

Sono, Eiko, Masuda, Tomoko, Takesako, Kazutoh, Kato, Ikunoshin, Uchida, Katsuhisa, Murayama, Somay Yamagata, and Yamaguchi, Hideyo

Abstract

Acid proteinases secreted by Candida tropicalisand C. parapsilosiswere newly isolated. Their physico‐chemical and enzymatic properties of molecular weight, pH stability, isoelectric points, specific activity, and N‐terminal amino acid sequences were determined and compared with those of a C. albicansacid proteinase. The two acid proteinases secreted by C. parapsilosiswere found to be new enzymes in their molecular weights. The acid proteinases from C. tropicalisand C. parapsilosisshowed lower activity at neutral pH, less resistance to neutral and alkaline pH than that from C. albicans, and a half or a third of the specific activity of the C. albicansenzyme. These differences seemed to be associated with the difference of pathogenesis between Candidaspecies. Of the 31 N‐terminal amino acids, the enzymes of these three Candidaspecies revealed 12 homologous amino acids.

Published
1992
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