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Biomedical subjects

K Nishimura

Publications and source records attributed to K Nishimura.

At least 19 recordsLinked to original sources

Purification of branched-chain amino acid aminotransferase from Helicobacter pylori NCTC 11637.

Branched-chain amino acid aminotransferase was purified by several column chromatographies from Helicobacter pylori NCTC 11637, and the N-terminal amino acid sequence was analyzed. The enzyme gene was sequenced based on a putative branched-chain amino acid aminotransferase gene, ilvE of H. pylori 26695, and the whole amino acid sequence was deduced from the nucleotide sequence. The enzyme existed in a homodimer with a calculated subunit molecular weight (MW) of 37,539 and an isoelectric point (pI) of 6.47. The enzyme showed high affinity to 2-oxoglutarate (K (m) = 0.085 mM) and L-isoleucine (K (m) = 0.34 mM), and V (max) was 27.3 micromol/min/mg. The best substrate was found to be L-isoleucine followed by L-leucine and L-valine. No activity was shown toward the D-enantiomers of these amino acids. The optimal pH and temperature were pH 8.0 and 37 degrees C, respectively.

Amino Acid Sequence↗

Laser-induced microexplosion confined in the bulk of a sapphire crystal: evidence of multimegabar pressures.

Extremely high pressures (approximately 10 TPa) and temperatures (5 x 10(5) K) have been produced using a single laser pulse (100 nJ, 800 nm, 200 fs) focused inside a sapphire crystal. The laser pulse creates an intensity over 10(14) W/cm2 converting material within the absorbing volume of approximately 0.2 microm3 into plasma in a few fs. A pressure of approximately 10 TPa, far exceeding the strength of any material, is created generating strong shock and rarefaction waves. This results in the formation of a nanovoid surrounded by a shell of shock-affected material inside undamaged crystal. Analysis of the size of the void and the shock-affected zone versus the deposited energy shows that the experimental results can be understood on the basis of conservation laws and be modeled by plasma hydrodynamics. Matter subjected to record heating and cooling rates of 10(18) K/s can, thus, be studied in a well-controlled laboratory environment.

Journal Article↗

Retrospective study of the effects of cyclosporine in comparison with azathioprine on renal transplant recipients infected with hepatitis C virus.

A recent report noted that cyclosporine (CsA) inhibits replication of the hepatitis C virus (HCV) in vitro. Thus, CsA may be a superior immunosuppressant for renal transplant recipients infected with HCV. In the present retrospective study, we assessed whether CsA reduced the clinical impact of HCV infection among those patients. A total of 405 renal transplants were performed between 1973 and 2005, of whom we studied 189 who received CsA-based immunosuppression (CsA group) vs 108 who received an azathioprine-based regimen (AZA group). There were 44 HCVAb carriers and 145 noncarriers in the CsA group, and 41 carriers and 67 noncarriers in the AZA group. Our results showed that patient survival rate was significantly worse among HCVAb carriers than among noncarriers, as the overall survival rates were 82.9% and 90.9%, respectively, after 10 years and 71.5% and 85.7%, respectively, after 20 years (P = .0003). Patient survival rates were also significantly worse in HCVAb carriers than in noncarriers in both groups, which were 83.2% and 95.0%, respectively, after 10 years, and 74.7% and 88.8%, respectively, after 20 years (P = .0147) in the CsA group, and 82.9% and 83.6%, respectively, after 10 years and 70.7% and 80.6%, respectively, after 20 years (P = .0171) in the AZA group. Conversely, no significant difference was seen in patient survival rate for HCVAb carriers between the two groups (83.2% vs 82.9% at 10 years, and 74.7% vs 70.7% at 20 years, P = .8195). Our results confirmed that HCV infection has a negative impact on the long-term survival of renal transplant patients who receive either a CsA-based or an AZA-based regimen, suggesting that CsA does not have a positive impact on HCV carriers.

Adult↗

Kidney transplantation in patients receiving dialysis treatment for more than 10 years.

In the present single center study, we analyzed 277 kidney transplant patients (procedures performed between February 1984 and February 2006) to determine the impact of long-term dialysis on kidney transplant outcomes. Forty-four had been treated prior to renal transplantation with dialysis for more than 10 years (range, 10.0-32.5 years, average, 16.6 years; Group I), while the remaining 233 recipients showed an average end-stage renal disease period of 2.8 years (range, 0-9.8 years; Group II). There were no significant differences in patient survivals between the 2 groups: 97.3% vs 97.4% at 1 year; 85.7% vs 92.4% at 5 years; 85.7% vs 90.7% at 10 years (P = .2347). Five Group I patients died: 2 from infections, 2 from liver dysfunction, and 1 from cerebral bleeding. These causes of death were similar to those among Group II patients. Graft survival was not significantly different between the 2 groups: 95% vs 88.8% at 1 year; 75.5% vs 76.5% at 5 years; 75.5% vs 65.5% at 10 years (P = .6264). Our results suggested that dialysis treatment for more than 10 years did not have negative effects on posttransplantation patient and graft survival.

Adult↗

Subcutaneous hyalohyphomycosis due to Cephalotheca foveolata in an immunocompetent host.

We report the first case of subcutaneous hyalohyphomycosis caused by the genus Cephalotheca, which has not been reported to cause human infection. A 67-year-old immunocompetent farmer presented with a 10-year history of verrucous erythematous plaques on the right foot dorsum, great toe, heel and sole. Histopathology of the lesions revealed chronic granulomatous inflammation with numerous nonpigmented fungal spores in the dermis. Cultures of biopsy specimens on Sabouraud's dextrose agar for 2 weeks developed into yellowish brown, velvety colonies that subsequently turned black after 8 weeks because of the production of black cleistothecia indicating the teleomorph. On the basis of mycological features, scanning electron microscopic morphology and molecular analysis data, a new species of Cephalotheca was identified and designated Cephalotheca foveolata. Because there was no response to the antifungal agents administered, the patient was successfully treated by surgical excision with skin graft.

Aged↗

Lung health in Japan.

Japan appears to be one of the healthiest nations. However, each step of healthcare services is not excellent while macroscopic outcomes are exceptional. Globalization is also key concept in Japanese respiratory healthcare services. As international communication between physicians become more common, the reality that various gaps in respiratory healthcare services still remain in place is becoming clearer. Now, clinicians are paying attention to global sources of information. Respiratory medicine will also change from experience-based medicine to evidence-based science.

Delivery of Health Care↗

[Unusual total anomalous pulmonary venous connection; report of a case].

We report a case of a 7-hour-old infant with total anomalous pulmonary venous connection having abberant origin of the vertical vein. His clinical condition presented hemodynamically severe pulmonary vein obstruction as common pulmonary vein atresia. Without making the definitive diagnosis, he underwent the operation at 11 hours after birth under cardiopulmonary bypass. During the operation, we could not identify the drainage vein. Although we ligated the vessel sized less than 2 mm in diameter draining into superior vena cava which was suspected to be the vertical vein. After the operation pulmonary edema was severe, but his clinical condition improved by using nitric oxide without extracorporeal membrane oxygenation (ECMO) support. Postoperative cardiac catheterization showed normal cardiac function without pulmonary venous obstruction, and moreover identified the drainage vein originated from right upper pulmonary vein. To the best of our knowledge, this is the first case where the vertical vein originated from right upper pulmonary vein. Immediate surgical treatment before the circuratory exacerbation improve the outcome for this congenital anomaly.

Humans↗

Evaluation of Fusarium solani hyphae and conidia susceptibility to amphotericin B and itraconazole: study of a clinical case.

Fusarium species are hyaline moulds belonging to the hyalohyphomycosis group that are usually found in the soil and plants. This organism has emerged as a cause of disseminated invasive disease. The correlation between in vitro value and clinical efficacy is low and many patients remain unresponsive to treatment despite in vitro susceptibility. We determined growth control for Fusarium solani using the BioCell-Tracer system that measures the growth rate of a single fungal hypha, and the effect of different concentrations of amphotericin B and itraconazole. The MIC for these two drugs was also determined by a broth microdilution technique, using RPMI 1640. Different MICs for amphotericin B were obtained by the two different methods. This paper describes a case of infection due to Fusarium solani in an allogeneic bone marrow transplanted patient, the microbiological diagnostic, antifungal susceptibility tests for conidia and hypha and clinical correlation.

Adult↗

Antifungal susceptibility and pathogenic potential of environmental isolated filamentous fungi compared with colonizing agents in immunocompromised patients.

Infection is a major cause of morbidity and mortality in bone marrow transplant recipients and in patients with hematological malignancies. The source of infection is almost always endogenous flora or the hospital environment. The present study evaluated bone marrow transplant recipients and patients with hematological malignancies colonized and/or infected with filamentous fungi. During 1 year, environmental air samples were also taken from the bone marrow transplant unit by a modification of gravity air-setting plate (GASP) methodology. Fusarium spp. were the most prevalent genus in the fall and Cladosporium spp. in the winter. Clinically isolated strains grew better at 37 degrees C than environmental strains. According to NCCLS M-38P methods, environmental Aspergillus strains showed higher MICs to miconazol and itraconazol, and clinical Fusarium strains were less susceptible to fluconazole.

Air Microbiology↗

Health-related quality of life in patients with idiopathic pulmonary fibrosis. What is the main contributing factor?

The prognosis of patients with idiopathic pulmonary fibrosis (IPF) is generally considered to be poor. As the disease progresses, patients invariably become severely limited in their activities. Therefore, evaluating the health-related quality of life (HRQoL) in IPF patients is considered to be important. However, there have been few studies of this kind to date. We applied the St. George's Respiratory Questionnaire (SGRQ) to 41 consecutive IPF patients and examined various physiological variables to identify factors that were correlated with the HRQoL. Total lung capacity, transfer factor, arterial partial pressure of oxygen at rest, the lowest oxygen saturation during exercise test, and the baseline dyspnoea index (BDI) score were significantly correlated with the total SGRQ score. A similar tendency was observed in each component. Conversely, peak oxygen uptake, known as one of the important factors that determines HRQoL in chronic obstructive pulmonary disease (COPD), did not correlate with any SGRQ scores. In stepwise multiple regression analysis, the BDI score was selected as the only factor significantly contributing to the total SGRQ score. Dyspnoea was the most important factor determining HRQoL in IPF. The types of other variables that correlated with the HRQoL in IPF patients were different from those in COPD.

Carbon Dioxide↗

Antigenuria and antigenaemia in experimental murine paracoccidioidomycosis.

In this study, Swiss mice were experimentally infected with Paracoccidoides brasiliensis (Pb18) and we investigated the levels of gp43 in urine and plasma, anti-gp43 and IgG-gp43 immune complexes in plasma. These levels were correlated with the histopathological findings. Blood and urine samples were collected from mice at 7, 28, 56 and 84 days after intravenous inoculation of 10(5) yeast cells, and analysed by ELISA. The results showed increased levels of soluble gp43 in the plasma in all periods, and anti-gp43 IgG and immune complexes after day 28. High gp43 levels were detected in the urine, except for day 28, coincident with the presence of compact granulomas in lungs. All the infected mice showed fungal cells in the lungs, with initial granulomatous lesions at day 7, dissemination of lesions to other organs at day 56, and granulomas lacking the surrounding mononuclear cells infiltration, especially at days 56 and 84. Our results suggest that gp43 diffuses passively into the urine, and the determination of gp43 levels in urine samples may be a non-invasive alternative method for diagnosis and follow up of PCM. Further studies are needed to determine if the cellular immune response correlate with decreased urine gp43 levels.

Animals↗

Interdigital involvement in a case of primary cutaneous canine histoplasmosis in Japan.

A 5-year-old male Siberian husky bred outdoor in Tokyo had a swollen paw with interdigital granulomatous lesions in the left hindlimb. The dog had no apparent pulmonary or gastrointestinal involvement. Histopathological analysis of the skin lesions demonstrated yeast-like organisms predominantly within macrophages. Sequence analysis of fungal ribosome RNA gene isolated from a paraffin sample revealed a 100% homology with the teleomorph of Histoplasma capsulatum. The present case may support the concept of primary cutaneous canine histoplasmosis as an endemic phenotype recognized in Japan.

Animals↗

Oral Candida flora from Brazilian human immunodeficiency virus-infected patients in the highly active antiretroviral therapy era.

One of the main opportunistic fungal infections amongst immunocompromised individuals is oral candidosis, which has been found in up to 90% of human immunodeficiency virus (HIV)-infected patients. This study employed yeasts isolated from the saliva and oral cavities of 114 HIV-infected patients living in Campinas, São Paulo. Of the isolates, 57.8% were identified as Candida albicans and 42.1% as non-C. albicans. The latter isolates were subsequently identified as C. krusei (7.5%), C. lusitaniae (5.2%), C. tropicalis (4.6%), C. parapsilosis (4.6%), C. glabrata (2.8%), C. kefyr (1.7%), C. guilliermondii (1.7%), C. intermedia (1.1%), C. norvegensis (0.5%), and Rhodotorula rubra (1.7%). Susceptibility of the isolates to amphotericin B, fluconazole, miconazole, and itraconazole was also determined by a microdilution method adopted by the National Committee for Clinical Laboratory Standards. The isolates demonstrated various susceptibilities to the antifungal agents. In particular 29 C. albicans and 13 non-C. albicans isolates showed low susceptibility to FLCZ (> 64 micro g/ml). This study revealed huge diversity of Candida species, in particular the increasing emergence of non-C. albicans associated with the oral flora of HIV-infected patients.

AIDS-Related Opportunistic Infections↗

Nocardial infections in Japan from 1992 to 2001, including the first report of infection by Nocardia transvalensis.

In the period from 1992 to 2001, 303 cases of nocardioses were diagnosed in Japan, with the corresponding etiological agents isolated and characterized. Taxonomic analyses of these 303 strains showed that most nocardial infections were caused by members of the Nocardia asteroides group (72.3%). Speciation showed that 72 strains were N. asteroides, 31 strains were N. cyriacigeorgica, 2 strains were N. beijingensis, 81 strains were N. farcinica, and 33 strains were N. nova. Sixty-six strains of N. brasiliensis were the next most prevalent species of the total Nocardia isolates, followed by 14 strains of N. otitidiscaviarum. Infections by N. transvalensis (3 strains) and N. pseudobrasiliensis (1 strain) were also confirmed. The infections due to N. transvalensis, N. cyriacigeorgica, and N. beijingensis were the first reported in Japan. The most common factor that predisposed individuals to nocardial infection in Japan was therapy by immunosuppressive agents (22.4%), including SLE therapy (3.6%), followed by cancer (6.6%), diabetes (3.6%) and AIDS (2.0%). Nocardial infections occurred more commonly in the elderly, with most of the patients between the ages of 61 and 80 years of age. No significant difference regarding infectivity levels between the sexes was observed.

Adolescent↗

Longitudinal changes in health status using the chronic respiratory disease questionnaire and pulmonary function in patients with stable chronic obstructive pulmonary disease.

Long-term changes in health status have been less evaluated in patients with chronic obstructive pulmonary disease (COPD), in comparison to the changes in forced expiratory volume in 1 s (FEV1). Accordingly, we examined the clinical course of health status as well as pulmonary function in COPD patients, and investigated the relationship between the change in health status and the change in pulmonary function in a 3-year longitudinal study involving 224 patients with COPD. Health status using the Chronic Respiratory Disease Questionnaire (CRQ) and pulmonary function were measured at baseline and every six months over three years. We used the random effects model for the slopes to estimate the longitudinal changes. A total of 147 patients completed the 3-year study. The dyspnoea, fatigue, and emotional function domains of the CRQ declined slowly but significantly over 3 years (p = 0.001, 0.003, and 0.004, respectively) with a mean decline rate of 0.08/year. This means that it would take about 6 years to reach the minimal important change of 0.5 on the CRQ. The mean decline in post-bronchodilator FEV1 was 60 ml/year. None of the changes in any of the domains of the CRQ were significantly correlated with the changes in pulmonary function. We have found that, in comparison to the decline in pulmonary function, health status evaluated by the CRQ declined significantly but very slowly in three of four domains over three years in patients with COPD. Furthermore, we have demonstrated that there was no significant relationship between the change in health status and the change in pulmonary function.

Aged↗

Comprehensive expression analysis of a rat depression model.

Herein we report on a large-scale analysis of gene expression in the 'learned helplessness' (LH) rat model of human depression, using DNA microarrays. We compared gene expression in the frontal cortex (FC) and hippocampus (HPC) of untreated controls, and LH rats treated with saline (LH-S), imipramine or fluoxetine. A total of 34 and 48 transcripts were differentially expressed in the FC and HPC, respectively, between control and LH-S groups. Unexpectedly, only genes for NADH dehydrogenase and zinc transporter were altered in both the FC and HPC, suggesting limited overlap in the molecular processes from specific areas of the brain. Principal component analysis revealed that sets of upregulated metabolic enzyme genes in the FC and downregulated genes for signal transduction in the HPC can distinguish clearly between depressed and control animals, as well as explain the responsiveness to antidepressants. This comprehensive data could help to unravel the complex genetic predispositions involved in human depression.

Animals↗