Biomedical subjects

Satoshi Kitamura

Publications and source records attributed to Satoshi Kitamura.

23 records · Page 2Linked to original sources

PubMed2002

Effect of magnetic field exposure on calcium channel currents using patch clamp technique.

Calcium influxes through the membrane of PC-12D cells were measured under exposure to DC biased AC magnetic fields in resonant conditions of the ion cyclotron and the ion parametric resonance hypotheses and compared with influxes in cells without exposure to the magnetic field. After cancellation of the geomagnetic field, the cells were exposed to the horizontal fields generated by a current sheet, a planar sheet of conductor which generated a satisfactorily homogeneous horizontal magnetic field on the stage of a microscope without hindering treatment of a cell under observation. At or near any resonant conditions, no change in calcium influx could be detected under standard patch clamp conditions.

Animals↗

PubMed2002

Evaluation of panipenem/betamipron (PAPM/BP) in pneumonia in elderly patients.

The present multicenter study evaluated the clinical and bacteriological efficacy and safety of panipenem/betamipron (PAPM/BP) for treating pneumonia in elderly patients. Forty-three episodes of pneumonia in 43 patients were treated with PAPM/BP as the sole antibiotic agent. All patients were 65 years of age or older, and were given PAPM/BP at a total daily dosage range of 0.5-2.0 g. The clinical efficacy rate, expressed as a percentage of the total number of excellent and good responses, was 56.4%. Of the 43 patients, 13 were evaluated bacteriologically. In these 13 patients, the eradication rate, expressed as a percentage of the total number of "eradicated" and "replaced" efficacies, was 30.8%. Adverse effects and abnormal laboratory findings occurred in 2 patients, which was 4.6% of the total number of patients evaluated. No serious adverse effects were observed. We concluded that PAPM/BP was well tolerated overall, and was effective and safe for most of the elderly patients.

Aged↗

PubMed2002

Trichosporon asahii-induced asthma in a family with Japanese summer-type hypersensitivity pneumonitis.

BACKGROUND: Trichosporon species frequently induce summer-type hypersensitivity pneumonitis (SHP), which is the most prevalent type of hypersensitivity pneumonitis (HP) in Japan, but have not been reported to induce asthma. OBJECTIVE: Evaluation of a case of asthma induced by Trichosporon asahii. METHODS AND RESULTS: This report describes a 46-year-old Japanese man who developed asthma induced by T. asahii, following symptoms of HP attributable to the same pathogen, in a case of familial occurrence of SHP. This patient lacked typical findings of HP in his radiograph but had an elevated level of eosinophils in his bronchoalveolar lavage fluid. Open lung biopsy, however, revealed typical pathologic findings of HP when he was free of asthmatic symptoms. His serum was also positive for anti-T asahii antibody, as are the sera of SHP patients. Nevertheless, provocation tests, including returning home and inhalations of T. asahii antigen, reproduced asthmatic features such as airway hyperresponsiveness and reversible bronchoobstruction, but not the features of HP. A skin test with the same antigen also evoked an immediate allergic reaction. An IgE mechanism was suspected but could not be proven by radioallergosorbent test. The patient's son and daughter displayed typical features of SHP, associated with compatible results in their radiographs, bronchoalveolar lavage fluid analysis, serologic and pathologic examinations, and provocation and skin tests. CONCLUSIONS: To our knowledge, this is the first case of extrinsic asthma, and of coexistent asthma and HP, induced by T. asahii. The patient initially displayed symptoms typical of SHP, which were subsequently replaced by more typical asthmatic symptoms.

Adolescent↗

PubMed2002

Effect of water content on the solid-state stability in two isomorphic clathrates of cephalosporin: cefazolin sodium pentahydrate (alpha form) and FK041 hydrate.

This study clearly demonstrates that clathrated water molecules can contribute to both chemical stabilization and destabilization of clathrates. The solid-state stabilities for two isomorphic clathrates of cephalosporin, cefazolin sodium and FK041, were investigated in terms of the effects of water content. The isomorphic ranges of water content were estimated to be 3.5-5 mol/mol for alpha-form cefazolin sodium and 2-4 mol/mol for FK041 hydrate. Upon the isomorphic dehydration, alpha-form cefazolin sodium was destabilized as the water content decreased below 4.25 mol/mol owing to the disruption of hydrogen bonding network in lattice channels. In this case, the hydration of clathrated water up to 4.25 mol/mol contributed to the physical and chemical stability of the crystals. On the contrary, the isomorphic hydration in FK041 hydrate contributed to the chemical destabilization owing to the high water activity. The difference in water activity between alpha-form cefazolin sodium and FK041 hydrate could be attributed to the size of water channels.

Cefazolin↗

PubMed1999

Effect of Pseudomonas aeruginosa exotoxin A on endotoxin-induced tumour necrosis factor production in murine lung.

The ability of several Pseudomonas aeruginosa exo-enzymes, including exotoxin A (ETA), to induce inflammation and their influence on endotoxin-induced tumour necrosis factor (TNF) production in murine lung were evaluated. Intratracheal administration of lipopolysaccharide (LPS; 0.1-10 microg/mouse), 2(-1) LD50 of P. aeruginosa alkaline protease (7.5 microg/mouse) and elastase (1.2 microg/mouse) elevated total cell number and the percentage of neutrophils in broncho-alveolar lavage fluid (BALF), whereas ETA (0.1 microg/mouse) did not. LPS induced TNF production in BALF in a dose-dependent manner, whereas the P. aeruginosa exo-enzymes did not. When ETA was inoculated into the respiratory tract before LPS, production of TNF in BALF was significantly suppressed in a dose-dependent manner. ETA also suppressed TNF production by alveolar macrophages (AMs) stimulated with LPS in vitro. Flow cytometric analysis showed that ETA markedly reduced the expression of CD14 and CD11c/CD18 on the surface of AMs. ETA also depressed partially the expression of TNF-alpha mRNA in AMs. These findings suggest that ETA regulates TNF production in murine lung by suppressing LPS receptor expression, mRNA expression and protein synthesis and/or secretion of TNF.

ADP Ribose Transferases↗