Yasuhito Higashiyama

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The features of chronic airway diseases, including chronic bronchitis, cystic fibrosis, bronchiectasis, and diffuse panbronchiolitis, include chronic bacterial infection and airway obstruction by mucus. Pseudomonas aeruginosa is one of the most common pathogens in chronic lung infection, and quorum-sensing systems contribute to the pathogenesis of this(More)
Coinfections of bacteria and influenza are a major cause of excessive mortality during influenza epidemics. However, the mechanism of the synergy between influenza virus and bacteria are poorly understood. In this study, mice were inoculated with influenza virus, followed 2 days later by inoculation with Streptococcus pneumoniae. The kinetics of viral(More)
We investigated the role of inflammatory cytokines in a mouse model of chronic Pseudomonas aeruginosa infection mimicking diffuse panbronchiolitis (DPB), and determined the effects of clarithromycin therapy on the production of these cytokines. The concentrations of IL-1beta, IL-2, IL-4, IL-5, interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha(More)
We successfully isolated Cryptococcus neoformans from chicken faeces in suburban areas of Thailand. C. neoformans was isolated from 36/150 houses (24.0%) in the dry season and 6/150 (4.0%) in the rainy season. All environmental isolates were of serotype A. The high isolation rate of 24% from chicken faeces has never been reported previously. Our(More)
Biofilms play an important role in the establishment of chronic infection caused by Pseudomonas aeruginosa. It has been suggested that membrane vesicles (MVs) are released into the surrounding medium during normal growth and might supply the bacterial extracellular DNA that is required for early biofilm formation, as MVs released from the bacterial outer(More)
Adult T-cell leukemia (ATL) is endemic in Kyushu. Our study at Hirado island in Nagasaki prefecture revealed a higher incidence (35.9%) of HTLV-I carriers in villages with fishing than in those without (16.5%). HTLV-I carriers showed a higher incidence of abnormal findings on chest roentgenogram (21.7%) than non-carriers (16.5%), but most were lesions of(More)
We established a mouse model in which fatal pneumonia was induced by pneumococcal superinfection following influenza virus infection in chronic Pseudomonas aeruginosa infected mice. In this mouse model, influenza virus infection caused a significant increase in inflammatory cells, cytokines and severe tissue damage in the lungs of these P. aeruginosa(More)
The aim of the present study was to elucidate the effect of the macrolide antibiotic azithromycin on Pseudomonas aeruginosa. We studied the susceptibility to azithromycin in P. aeruginosa PAO1 using a killing assay. PAO1 cells at the exponential growth phase were resistant to azithromycin. In contrast, PAO1 cells at the stationary growth phase were(More)
OBJECTIVE To evaluate the clinical usefulness of sulbactam/ampicillin therapy for community-acquired pneumonia in the elderly. METHODOLOGY A randomized prospective clinical study was conducted in the elderly patients with moderate-to-severe community-acquired bacterial pneumonia. RESULTS Overall clinical efficacy of sulbactam/ampicillin therapy (6(More)
A novel, rapid, and noninvasive test (ODK0501) to detect Streptococcus pneumoniae antigen was evaluated in a Japanese multicenter study. ODK0501 uses polyclonal antibodies to detect C polysaccharide of S. pneumoniae from sputum samples by an immunochromatographic assay. The utility of ODK0501 was evaluated for 161 adult patients with lower respiratory tract(More)