Masafumi Seki

Publications (94)190.09 Total impact

• Article: TLR4 agonistic antibody promotes innate immunity against severe pneumonia induced by co-infection with influenza virus and Streptococcus pneumoniae.

  Akitaka Tanaka, Shigeki Nakamura, Masafumi Seki, Kenji Fukudome, Naoki Iwanaga, Yoshifumi Imamura, Taiga Miyazaki, Koichi Izumikawa, Hiroshi Kakeya, Katsunori Yanagihara, Shigeru Kohno
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  ABSTRACT: Co-infection with bacteria is a major cause of mortality during influenza epidemics. Recently, toll-like receptor (TLR) agonists have been shown to have immunomodulatory functions. In the present study, we investigated the effectiveness and mechanisms of the new TLR4 agonistic monoclonal antibody UT12 against secondary pneumococcal pneumonia induced by co-infection with influenza virus in a mouse model. Mice were intranasally inoculated with Streptococcus pneumoniae 2 days after influenza virus inoculation. UT12 was intraperitoneally administered 2 h before each inoculation. Survival rate and body weight loss were significantly improved by UT12 administration. Additionally, the production of inflammatory mediators was significantly suppressed by administration of UT12. In a histopathological study, pneumonia in UT12-treated mice was very mild compared to that in control mice. UT12 increased antimicrobial defense through acceleration of macrophage recruitment into the lower respiratory tract induced by c-Jun N-terminal kinase (JNK) and nuclear factor-kappaB (NF-κB) pathway-dependent monocyte chemoattractant protein (MCP)-1 production. Collectively, these findings indicated that UT12 promoted pulmonary innate immunity and may reduce the severity of severe pneumonia induced by co-infection with influenza virus and S. pneumoniae. This immunomodulatory effect of UT12 improves the prognosis of secondary pneumococcal pneumonia and makes it an attractive candidate for treating severe infectious diseases.
  Clinical and vaccine immunology: CVI 05/2013; · 2.37 Impact Factor
• Article: Identification of neutrophil extracellular traps in the blood of patients with systemic inflammatory response syndrome.

  Shigeto Hamaguchi, Tomoya Hirose, Yukihiro Akeda, Naoya Matsumoto, Taro Irisawa, Masafumi Seki, Hideo Hosotsubo, Osamu Tasaki, Kazunori Oishi, Takeshi Shimazu, Kazunori Tomono
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  ABSTRACT: Neutrophils are able to form 'neutrophil extracellular traps' (NETs), which they use to trap and kill pathogens such as bacteria and fungi at the foci of infection. This observational study investigated the presence of NETs in the blood from critically ill patients and healthy volunteers. Fluorescent triple-colour immunocytochemical analysis of blood smears collected from patients with systemic inflammatory response syndrome (SIRS; associated with various clinical conditions) who had been hospitalized in the intensive care unit, and healthy volunteers, was undertaken to identify NETs in the blood. Blood smears were stained for DNA, histone H1 and neutrophil elastase. NETs were identified in 10 of 21 (47.6%) blood samples from the study group compared with none of the blood samples from eight healthy volunteers. These data suggest that fluorescent triple-colour immunocytochemical staining of NETs in the blood could be used to simplify the early identification of critically ill patients with SIRS. Larger studies are required to clarify the pathophysiological role of NETs in this specific patient population.
  The Journal of international medical research 02/2013; 41(1):162-8. · 0.90 Impact Factor
• Article: [The role of neutrophil extracellular traps -a translational research between infection and allergy].

  Shigeto Hamaguchi, Masafumi Seki, Kazunori Tomono
  Arerugī = [Allergy] 12/2012; 61(12):1729-35.
• Article: [Infectious diseases: progress in diagnosis and treatment topics: I. Infectious diseases in unusual circumstances. 2. The issue raised by 2011 NHCAP guideline in Japan].

  Masafumi Seki, Kazunori Tomono
  Nihon Naika Gakkai Zasshi 11/2012; 101(11):3097-102.
• Article: Dynamic changes in the expression of neutrophil extracellular traps in acute respiratory infections.

  Tomoya Hirose, Shigeto Hamaguchi, Naoya Matsumoto, Taro Irisawa, Masafumi Seki, Osamu Tasaki, Hideo Hosotsubo, Kazunori Tomono, Takeshi Shimazu
  American Journal of Respiratory and Critical Care Medicine 05/2012; 185(10):1130-1. · 11.08 Impact Factor
• Article: Prediction of Requirement for Mechanical Ventilation in Community-Acquired Pneumonia with Acute Respiratory Failure: A Multicenter Prospective Study.

  Shigeru Kohno, Masafumi Seki, Koji Takehara, Yoshitsugu Yamada, Keishi Kubo, Akitoshi Ishizaka, Kazui Soma
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  ABSTRACT: Background: Several severity scoring systems for predicting mortality are established in community-acquired pneumonia (CAP). Objectives: The predictability of the aggravation such as requirement for mechanical ventilation in addition to mortality was examined in CAP patients with acute respiratory failure by using the age, dehydration, respiratory failure, orientation disturbance and blood pressure (A-DROP) scoring system which was proposed by the Japanese Respiratory Society. Methods: This study was a prospective, multicenter, observational cohort study. The severity of pneumonia was examined using A-DROP and Pneumonia Severity Index (PSI) which originated from the Infectious Disease Society of America. Requirement for mechanical ventilation and mortality were evaluated for 28 days. Results: 482 CAP patients with acute respiratory failure were enrolled in the study. The 28-day mortality and mechanical ventilation rates were 12.3 and 14.4%, respectively. There were no significant differences in the areas under the receiver-operator characteristic curves for prediction of mortality between A-DROP and PSI (χ(2) test; p = 0.3613). In the subgroup analyses by -severity, the A-DROP scoring system showed a severity-dependent increase of mortality (moderate 5.6%, severe 16.1%, extremely severe 27.1%, Cochran-Armitage trend test; p < 0.0001). Similar results were obtained for mechanical ventilation rate (moderate 9.8%, severe 16.7%, extremely severe 25.4%, Cochran-Armitage trend test; p = 0.0006). The compliance with scoring the A-DROP was higher than that with scoring the PSI (96.9 vs. 71.6%). Conclusions: The results of this study suggest that the A-DROP scoring system could be a simple CAP risk scoring system which could predict not only mortality, but also the requirement for mechanical ventilation.
  Respiration 02/2012; · 2.26 Impact Factor
• Article: Correlation between the consumption of meropenem or doripenem and meropenem susceptibility of Pseudomonas aeruginosa in a university hospital in Japan.

  Koji Miyawaki, Yoshihiro Miwa, Masafumi Seki, Seishi Asari, Kazunori Tomono, Nobuo Kurokawa
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  ABSTRACT: The appropriate use of carbapenems is essential in order to prevent resistance in Pseudomonas aeruginosa. We investigated the correlation between the consumption of meropenem or doripenem and the susceptibility of P. aeruginosa to meropenem in a Japanese university hospital from 2004 to 2009. The susceptibility data of P. aeruginosa and the annual consumption of meropenem or doripenem were analyzed. The consumption of meropenem or doripenem was calculated using the Anatomic Therapeutic Chemical classification and defined daily doses methodology. Meropenem consumption decreased and doripenem consumption increased and throughout the entire investigation period, total consumption of meropenem plus doripenem was stable. Although the annual number of isolated P. aeruginosa has not changed, the annual number of isolated multidrug resistant P. aeruginosa decreased by measures against nosocomial infection. The rate of meropenem resistant P. aeruginosa decreased in a time-dependent manner. Meropenem consumption was positively correlated with the meropenem resistance rate among P. aeruginosa (r = 0.9455, p<0.01). The total consumption of meropenem and doripenem was not correlated with the meropenem resistance rate (r = -0.6601, p>0.1). These results suggested that even if the total consumption of meropenem plus doripenem was not changed, meropenem susceptibility among P. aeruginosa improved by the decrease of meropenem consumption. Although meropenem and doripenem have been suggested to show cross-resistance with each other, the reduction of meropenem consumption might be effective for preventing an increase of meropenem-resistant P. aeruginosa.
  Biological & Pharmaceutical Bulletin 01/2012; 35(6):946-9. · 1.66 Impact Factor
• Article: Loading regimen required to rapidly achieve therapeutic trough plasma concentration of teicoplanin and evaluation of clinical features.

  Masafumi Seki, Kaori Yabuno, Koji Miyawaki, Yoshihiro Miwa, Kazunori Tomono
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  ABSTRACT: A trough concentration of >20 mg/L is considered the optimal dosage of teicoplanin required to ensure early therapeutic effects against methicillin-resistant Staphylococcus aureus (MRSA) infections including those in patients who develop febrile neutropenia after chemotherapy. This study determines appropriate initial doses during the first 2 days of administration and evaluates the therapeutic target teicoplanin trough concentration. A 2-day regimen was evaluated in patients treated with 600 mg and 1200 mg or 1200 mg and 600 mg (total 1800 mg, Group 1), 800 mg and 800 mg (total 1600 mg, Group 2), and 800 mg and 400 mg (total 1200 mg, Group 3) of teicoplanin on Days 1 and 2, respectively. We also compared the efficiency and adverse effects at trough concentrations of 15-20 mg/L (Group A, n = 28) with >20 mg/L (Group B, n = 27) of teicoplanin, and also compared them with those on the similar concentrations of vancomycin (Groups C and D, n = 50 and 34, respectively). The mean trough concentrations of teicoplanin on Days 4 or 5 were 22.2, 17.5, and 16.2 mg/L in Groups 1, 2, and 3, respectively. The clinical efficiency was 85.7%, 81.5%, 92.0%, and 91.5%, in Groups A, B, C, and D, respectively. The rates of adverse effects were not high in teicoplanin (nephrotoxicity, 7.1% and 3.7%, and hepatotoxicity, 14.3% and 11.1% in Groups A and B, respectively). However, more adverse effects tended to arise in patients who received vancomycin in nephrotoxicity (14.0% and 11.8%, in Groups C and D, respectively). These results suggest that the 2-day regimens with total 1800 mg achieved the most effective therapeutic trough plasma concentration of teicoplanin (20 mg/L). However, 15-20 mg/L might also be an effective trough target for initial teicoplanin treatment. These teicoplanin regimens might be safer in terms of renal function than vancomycin.
  Clinical Pharmacology: Advances and Applications 01/2012; 4:71-5.
• Article: Case of invasive nontypable Haemophilus influenzae respiratory tract infection with a large quantity of neutrophil extracellular traps in sputum.

  Shigeto Hamaguchi, Masafumi Seki, Norihisa Yamamoto, Tomoya Hirose, Naoya Matsumoto, Taro Irisawa, Ryosuke Takegawa, Takeshi Shimazu, Kazunori Tomono
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  ABSTRACT: Haemophilus influenzae type b was once the most common cause of invasive H. influenzae infection, but the incidence of this disease has decreased markedly with introduction of conjugate vaccines to prevent the disease. In contrast, the incidence of invasive infection caused by nontypable H. influenzae has increased in the US and in European countries. Neutrophil extracellular traps (NETs) are fibrous structures released extracellularly from activated neutrophils during inflammation, including in pneumonia, and rapidly trap and kill pathogens as a first line of immunological defense. However, their function and pathological role have not been fully investigated. Here, we report a case of fatal nontypable H. influenzae infection with severe pneumonia and bacteremia in an adult found to have a vast amount of NETs in his sputum. The patient had a two-day history of common cold-like symptoms and was taken to the emergency room as a cardiopulmonary arrest. He recovered temporarily, but died soon afterwards, although appropriate antibiotic therapy and general management had been instituted. Massive lobular pneumonia and sepsis due to nontypable H. influenzae was found, in spite of H. influenzae type b vaccine being available. His sputum showed numerous bacteria phagocytosed by neutrophils, and immunohistological staining indicated a number of NETs containing DNA, histone H3, and neutrophil elastase. This case highlights an association between formation of NETs and severe respiratory and septic infection. An increase in severe nontypable H. influenzae disease can be expected as a result of "pathogen shift" due to increased use of the H. influenzae type b vaccine in Japan.
  Journal of Inflammation Research 01/2012; 5:137-40.
• Article: [Blood test-importance of C-reactive protein].

  Masafumi Seki, Kazunori Tomono
  Nihon Naika Gakkai Zasshi 12/2011; 100(12):3522-6.
• Article: Functional characterization of the regulators of calcineurin in Candida glabrata.

  Taiga Miyazaki, Koichi Izumikawa, Yohsuke Nagayoshi, Tomomi Saijo, Shunsuke Yamauchi, Yoshitomo Morinaga, Masafumi Seki, Hiroshi Kakeya, Yoshihiro Yamamoto, Katsunori Yanagihara, Yoshitsugu Miyazaki, Shigeru Kohno
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  ABSTRACT: The serine-threonine-specific protein phosphatase calcineurin is a key mediator of various stress responses in fungi. Herein, we characterized functions of the endogenous regulators of calcineurin (RCNs), Rcn1 and Rcn2, in the pathogenic fungus Candida glabrata. Rcn1 exerted both inhibitory and stimulatory effects on calcineurin signaling, but Rcn2 displayed only inhibitory activity. Phenotypic analyses of C. glabrata strains lacking either RCNs, calcineurin, or both revealed that calcineurin requires Rcn1, but not Rcn2, for antifungal tolerance in C. glabrata.
  FEMS Yeast Research 12/2011; 11(8):621-30. · 2.40 Impact Factor
• Article: Increase of apoptosis in a murine model for severe pneumococcal pneumonia during influenza A virus infection.

  Kosuke Kosai, Masafumi Seki, Akitaka Tanaka, Yoshitomo Morinaga, Yoshifumi Imamura, Koichi Izumikawa, Hiroshi Kakeya, Yoshihiro Yamamoto, Katsunori Yanagihara, Kazunori Tomono, Shigeru Kohno
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  ABSTRACT: The mechanisms of severe pneumonia caused by co-infection of bacteria and influenza A virus (IAV) have not been fully elucidated. We examined apoptosis and inflammatory responses in a murine model for pneumococcal pneumonia during IAV infection. Inflammation, respiratory epithelium apoptosis, and inflammatory-cell infiltration increased in a time dependent manner in the lungs of mice co-infected with Streptococcus pneumoniae and IAV, in comparison with those infected with either S. pneumoniae or IAV. According to appearance of terminal deoxynucleotidyl transferase dUTP-mediated nick-end labeling positive cells, caspases-3 and -8 were activated 24 h after S. pneumoniae infection, and caspase-3 activation decreased after 48 h, whereas inflammatory cytokine levels continued to increase in co-infected mice. In contrast, in mice infected with either IAV or S. pneumoniae, apoptosis and activation of factors related to caspase-3 peaked at 48 h. Furthermore, Fas-associated death domain was significantly expressed in the lungs of co-infected mice 24 h after S. pneumoniae infection. These data suggest that early onset of apoptosis and its related factors play important roles in fulminant pneumonia resulting from bacterial pneumonia complicated by co-infection with influenza virus.
  Japanese journal of infectious diseases. 11/2011; 64(6):451-7.
• Article: The glycosylphosphatidylinositol‐linked aspartyl protease Yps1 is transcriptionally regulated by the calcineurin‐Crz1 and Slt2 MAPK pathways in Candida glabrata

  Taiga Miyazaki, Koichi Izumikawa, Shunsuke Yamauchi, Tatsuo Inamine, Yohsuke Nagayoshi, Tomomi Saijo, Masafumi Seki, Hiroshi Kakeya, Yoshihiro Yamamoto, Katsunori Yanagihara, Yoshitsugu Miyazaki, Akira Yasuoka, Shigeru Kohno
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  ABSTRACT: In the pathogenic fungus Candida glabrata, the YPS1 gene, which encodes a glycosylphosphatidylinositol-linked aspartyl protease, is required for cell wall integrity and virulence. Although the expression of YPS1 has been studied in Saccharomyces cerevisiae, the transcriptional regulation of this gene in C. glabrata is not well understood. Here, we report that C. glabrata Yps1 is required for cell growth at elevated temperatures, and that the heat-induced expression of YPS1 is regulated predominantly by the calcineurin-Crz1 pathway and partially by the Slt2 MAPK pathway. Although a total of 11 YPS genes are present in the C. glabrata genome, the loss of transcriptional induction in a calcineurin mutant was observed only for YPS1. The results of a YPS1 promoter-lacZ reporter assay using a series of constructs with mutated promoter elements indicated that the transcription factor Crz1 binds to multiple sites in the promoter region of YPS1. To date, as none of the putative Crz1 targets in C. glabrata have been characterized using a Δcrz1 mutant, monitoring the expression of YPS1 represents an effective method for measuring the activity of the calcineurin-Crz1 signaling pathway in this fungus.
  FEMS Yeast Research 05/2011; 11(5):449 - 456. · 2.40 Impact Factor
• Article: The glycosylphosphatidylinositol-linked aspartyl protease Yps1 is transcriptionally regulated by the calcineurin-Crz1 and Slt2 MAPK pathways in Candida glabrata.

  Taiga Miyazaki, Koichi Izumikawa, Shunsuke Yamauchi, Tatsuo Inamine, Yohsuke Nagayoshi, Tomomi Saijo, Masafumi Seki, Hiroshi Kakeya, Yoshihiro Yamamoto, Katsunori Yanagihara, Yoshitsugu Miyazaki, Akira Yasuoka, Shigeru Kohno
  [show abstract] [hide abstract]
  ABSTRACT: In the pathogenic fungus Candida glabrata, the YPS1 gene, which encodes a glycosylphosphatidylinositol-linked aspartyl protease, is required for cell wall integrity and virulence. Although the expression of YPS1 has been studied in Saccharomyces cerevisiae, the transcriptional regulation of this gene in C. glabrata is not well understood. Here, we report that C. glabrata Yps1 is required for cell growth at elevated temperatures, and that the heat-induced expression of YPS1 is regulated predominantly by the calcineurin-Crz1 pathway and partially by the Slt2 MAPK pathway. Although a total of 11 YPS genes are present in the C. glabrata genome, the loss of transcriptional induction in a calcineurin mutant was observed only for YPS1. The results of a YPS1 promoter-lacZ reporter assay using a series of constructs with mutated promoter elements indicated that the transcription factor Crz1 binds to multiple sites in the promoter region of YPS1. To date, as none of the putative Crz1 targets in C. glabrata have been characterized using a Δcrz1 mutant, monitoring the expression of YPS1 represents an effective method for measuring the activity of the calcineurin-Crz1 signaling pathway in this fungus.
  FEMS Yeast Research 04/2011; 11(5):449-56. · 2.40 Impact Factor
• Source

  Available from: nagasaki-u.ac.jp

  Article: High-dose tobramycin inhibits lipopolysaccharide-induced MUC5AC production in human lung epithelial cells.

  Shigeki Nakamura, Katsunori Yanagihara, Nobuko Araki, Koichi Yamada, Yoshitomo Morinaga, Koichi Izumikawa, Masafumi Seki, Hiroshi Kakeya, Yoshihiro Yamamoto, Shimeru Kamihira, Shigeru Kohno
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  ABSTRACT: Tobramycin inhalation therapy is an effective therapy for cystic fibrosis as well as severe bronchiectasis that is colonized with Pseudomonas aeruginosa. The mechanism responsible for the efficacy of tobramycin in the treatment of severe chronic infectious diseases has not been elucidated. We demonstrate that high-dose tobramycin decreases MUC5AC gene expression and protein production in NCI-H292 cell stimulated with lipopolysaccharide of P. aeruginosa. MUC5AC protein of NCI-H292 cell stimulated by lipopolysaccharide was analyzed by an enzyme-linked immunosorbent assay and MUC5AC expression at the mRNA level was analyzed by RT-PCR. Western blot was performed to examine a potential role for the signaling molecules upstream of NFκB. High-dose tobramycin (500μg/ml) decreased the level of MUC5AC protein released into the supernatant of the NCI-H292 cell line at 24h after lipopolysaccharide stimulation (P<0.001). The tobramycin treatment also inhibited MUC5AC mRNA expression at 12h after lipopolysaccharide stimulation (P<0.05) and suppressed NFκB activation 60min after lipopolysaccharide stimulation (P<0.001). Tobramycin suppressed the phosphorylation of extracellular signal-regulated protein kinase, p38 MAP kinase. These results suggest that high-dose tobramycin, such as inhalation therapy, can inhibit MUC5AC gene expression and MUC5AC protein production in NCI-H292 cells, in part through the mitogen-activated protein kinase pathway. Thus, the activation of TLR4 and the subsequent immune/inflammatory responses induced by chronic infections such as P. aeruginosa might be modulated by tobramycin. Our data may reveal one of the mechanisms responsible for the clinical effect of tobramycin inhalation therapy against severe chronic respiratory diseases due to P. aeruginosa.
  European journal of pharmacology 03/2011; · 2.59 Impact Factor
• Article: Evaluation of an assessment system for the JRS 2005: A-DROP for the management of CAP in adults.

  Shigeru Kohno, Masafumi Seki, Akira Watanabe
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  ABSTRACT: The Japanese Respiratory Society (JRS) last revised the guidelines for community-acquired pneumonia (CAP) in adults in 2005. These guidelines proposed new criteria (A-DROP) to assess the severity of pneumonia and to differentiate between typical bacterial pneumonia and atypical pneumonia. The goal of the present study was to evaluate the utility of the A-DROP criteria for these described purposes. An observational survey was conducted between July 2006 and March 2007, and patients with CAP were prospectively surveyed using consecutive enrollment methods. In total, 1,875 patients from 200 medical facilities throughout Japan were analyzed. The JRS 2005 A-DROP system was a good indicator of mortality in the patient population, and these results were significantly correlated with the Pneumonia Severity Index (PSI) of the Infectious Disease Society of America (IDSA). Among the various factors characterized, 'SpO(2) of 90% or less (PaO(2) of 60 Torr or less)' was the strongest predictor of mortality. In terms of the differential diagnosis between typical bacterial and atypical pneumonia, five of six JRS 2005 items were strongly and significantly correlated with a diagnosis of atypical pneumonia. The JRS 2005 A-DROP system was accurate and clinically useful for the assessment of the severity of pneumonia and for the differentiation between typical bacterial pneumonia and atypical pneumonia.
  Internal Medicine 01/2011; 50(11):1183-91. · 0.94 Impact Factor
• Article: Evaluation of the Cica Fungi Test Candida, a novel serum Candida mannan antigen kit, and its comparison with Cand-Tec in candidemia patients.

  Takahiro Takazono, Koichi Izumikawa, Yosuke Nagayoshi, Akitaka Tanaka, Tomo Mihara, Kosuke Kosai, Tomomi Saijo, Yoshifumi Imamura, Taiga Miyazaki, Masafumi Seki, Hiroshi Kakeya, Yoshihiro Yamamoto, Katsunori Yanagihara, Shimeru Kamihira, Shigeru Kohno
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  ABSTRACT: The Cica Fungi Test Candida is a novel immunoassay test that is used in Japan to detect Candida mannan antigens. A total of 130 samples from 89 cases in which the β-D-glucan assay (MK method) was positive were collected between July 2007 and August 2008 at Nagasaki University Hospital, and the Cica Fungi Test Candida and Cand-Tec were performed. Diagnosis of candidemia was based on a positive culture for Candida spp. from blood or other sterile clinical specimens. A total of 19 samples from 16 cases with candidemia, and 111 samples from 73 cases without microbiological evidence of candidemia, were obtained. The sensitivity and specificity of the Cica Fungi Test and Cand-Tec were 63.2 and 95.5%, and 52.6 and 50.5%, respectively. The Cica Fungi Test showed significantly higher specificity than Cand-Tec (P<0.01). The β-D-glucan assay values were significantly higher in the candidemia samples than in the non-candidemia samples (P=0.0003), a result that was well correlated with the Cica Fungi Test (P=0.0005). The Cica Fungi Test was thus found to be more reliable and specific than Cand-Tec, and the combined evaluation with the β-D-glucan assay was more efficient for diagnosis of candidemia.
  Japanese journal of infectious diseases. 01/2011; 64(2):116-20.
• Source

  Available from: nagasaki-u.ac.jp

  Article: Clinical features of bacteremia caused by methicillin-resistant Staphylococcus aureus in a tertiary hospital.

  Koichi Yamada, Katsunori Yanagihara, Yukiko Hara, Nobuko Araki, Yousuke Harada, Yoshitomo Morinaga, Junichi Matsuda, Koichi Izumikawa, Masafumi Seki, Hiroshi Kakeya, Yoshihiro Yamamoto, Shigeru Kohno, Shimeru Kamihira
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  ABSTRACT: Methicillin-resistant Staphylococcus aureus (MRSA) has become a leading cause of infections in both the community and in hospitals. MRSA bacteremia is a serious infection with a very high mortality rate. The aim of this study was to assess the clinical features of MRSA bacteremia and to evaluate predictors of mortality in patients with this infection. The medical records of 83 patients with MRSA bacteremia, who had been admitted to Nagasaki University Hospital between January 2003 and December 2007, were retrospectively reviewed. Underlying disease, presumed source, MRSA sensitivity, Staphylococcal cassette chromosome mec (SCCmec) types, virulence genes and prognosis were evaluated. Of the 83 patients (44 men and 39 women; mean age: 63.7 years) with MRSA bacteremia, 30 (36.1%) had malignancy and 25 (30.1%) had been treated with immunosuppressive drugs. Fifteen patients (18.1%) were intravascular catheter related. SCCmec typeII accounted for 80% of SCCmec types of MRSA isolates. The mortality rate was 39.8% (33/83), which is similar to that of previous reports. The ratio of males to females, the mean age or the body temperature did not differ between survivors and nonsurvivors. Independent predictors associated with mortality in the multivariate analyses are pneumonia (P = 0.016), treatment with VCM (P = 0.039), and transplantation (P = 0.021). We suggest that poor prognosis achieved with VCM is in part due to its low blood concentration and poor tissue penetration. VCM should not be selected when presumed source of MRSA bacteremia is pneumonia.
  The Tohoku Journal of Experimental Medicine 01/2011; 224(1):61-7. · 1.24 Impact Factor
• Source

  Available from: aspergillus.org.uk

  Article: Diagnostic significance of Aspergillus species isolated from respiratory samples in an adult pneumology ward.

  Takayoshi Tashiro, Koichi Izumikawa, Masato Tashiro, Takahiro Takazono, Yoshitomo Morinaga, Kazuko Yamamoto, Yoshifumi Imamura, Taiga Miyazaki, Masafumi Seki, Hiroshi Kakeya, Yoshihiro Yamamoto, Katsunori Yanagihara, Akira Yasuoka, Shigeru Kohno
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  ABSTRACT: Although the diagnostic significance of isolating Aspergillus spp. from respiratory cultures has been studied in immunocompromised hosts with invasive pulmonary aspergillosis (IPA), little is known of such infections in immunocompetent patients with other forms of aspergillosis. In this study of adult pneumology ward patients, we examined the association between Aspergillus spp. and disease prevalence. Laboratory records from April 1998 to March 2009 were reviewed to identify patients with Aspergillus spp. in respiratory samples. Correlations between the isolated species and clinical characteristics of patients were evaluated. During the study period, 165 Aspergillus spp. isolates were detected in the respiratory cultures of 139 patients. Of these patients, 62 (45%) were colonized with Aspergillus spp. and displayed no clinical symptoms of aspergillosis, while 77 (55%) had a form of pulmonary aspergillosis, characterized as either chronic necrotizing pulmonary aspergillosis (CNPA) (48%), aspergilloma (29%), IPA (13%), or allergic bronchopulmonary aspergillosis (ABPA) (10%). The dominant species were Aspergillus fumigatus (41%), A. niger (32%), and A. versicolor (12%). A. fumigatus was most commonly isolated in patients with IPA, aspergilloma, and CNPA, whereas A. niger was the dominant species in colonized patients and those with ABPA. Isolation of an Aspergillus spp. from respiratory samples does not confirm it as the etiologic pathogen because airway colonization by Aspergillus spp. is a common feature in several chronic lung diseases. Repeated isolation of the identical Aspergillus species and detection of anti-Aspergillus antibodies and/or Aspergillus antigens in sera are needed to determine the isolate represents the etiologic agent of disease.
  Medical mycology: official publication of the International Society for Human and Animal Mycology 01/2011; 49(6):581-7. · 2.13 Impact Factor
• Article: [Mechanisms and theraupeutic analysis for severe influenza-related pneumonia].

  Masafumi Seki, Akitaka Tanaka, Kosuke Kosai, Shigeru Kohno
  Kansenshogaku zasshi. The Journal of the Japanese Association for Infectious Diseases 11/2010; 84(6):689-93.