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Biomedical subjects

J Nakamura

Publications and source records attributed to J Nakamura.

At least 199 records · Page 11Linked to original sources
PubMed1998

[Nosocomial pneumonia experienced in a community hospital].

To clarify the characteristic features of nosocomial pneumonia in a community hospital, we performed a clinical analysis of 147 patients (155 episodes) with nosocomial pneumonia. The following results were obtained. 1, Regarding the risk factors for nosocomial pneumonia, factors such as the patient whose age was over 65 years, a duration of admission of over one month, performance status 4 and underlying respiratory diseases associated with the appearance of nosocomial pneumonia. 2, The causative microorganism isolated from the sputum of the patient with nosocomial pneumonia was frequently a multi-drug resistant microorganism such as Methicillin-resistant Staphylococcus aureus (MRSA). 3, regarding treatment, although several antibiotics were administered for a long time, mechanical ventilation was used on 31% of the patients, and steroid pulse therapy was carried out on 24%. The clinical efficacy was poor with a 50% mortality rate. The reason why treatment of nosocomial pneumonia was difficult is thought to be been related to the general condition of these inpatients and to the appearance of a multi-drug resistant, polymicrobial microorganisms.

Adult↗
PubMed1998

[A case with chronic active EB virus infection accompanied with pulmonary candidiasis].

A 44-year-old woman with a history of intermittent fever for several years was admitted because of burn on her leg. On admission, she had hepatosplenomegaly and fever. Antibiotic therapy was started for bacterial infection of the burn. She lost her appetite and IVH was started. During the treatment, high fever appeared and chest X-ray films showed multiple nodular infiltrates throughout both lung fields. Candida albicans was isolated from IVH catheter culture and pulmonary candidiasis was suspected. Her fever and lung involvements were successfully treated with fluconazole. During the course, serum anti-EB-VCA-IgG antibody persisted at a high titer and anti-EBNA antibody remained negative. EB virus DNA was detected in the peripheral blood and bone marrow. Thus, she was diagnosed as chronic active EB virus infection.

Adult↗
PubMed1998

[A case of Listeria monocytogenes sepsis in an elderly who survived].

A 81-year-old man who complained of fever and disturbance of consciousness was admitted to our hospital. Listeria monocytogenes type 1/2aA was cultured from only the blood. He was treated with gamma-globrine and sensitive antibiotics (PAPM/BP, EM) immediately after admission, and recovered in spite of multiple organ failure due to septic shock. He was not an immunocompromised host and did not have complication of meningitis, but had rhabdomyolysis and liver dysfunction.

Aged↗
PubMed1998

[Clinical analysis of patients with severe pneumonia requiring mechanical ventilation].

To clarify the clinical features and select the appropriate antibiotic therapy for patients with severe pneumonia requiring mechanical ventilation, we performed a clinical analysis of 65 patients with this condition. The following results were obtained. The majority of the patients were elderly males, whose performance status was poor (PS 2.2) and who had an underying disease. Abnormal physical signs included tachypnea, tachycardia and consciousness disturbance. Abnormal laboratory findings included hypoalbuminemia, and liver and renal dysfunction. The causative microorganisms were isolated from half of these patients. A number of antibiotics were administered and steroid pulse therapy was also performed for half of these patients. Nevertheless the prognosis was poor because the percentage of deaths was high (50.8%).

Adult↗
PubMed1998

[Clinical analysis of patients with nosocomial pneumonia during mechanical ventilation (so-called ventilator-associated pneumonia)].

To clarify the clinical features of nosocomial pneumonia during mechanical ventilation (ventilator-associated pneumonia) and to select the appropriate antibiotic therapy for patients, we performed a clinical analysis of 19 patients (26 episodes) with this condition. The following results were obtained. 1, The average age of the patients was 68 years old (male 16, female 3). 2, VAP occurred three times in 2 cases, twice in 3 cases, and once in 14 cases. 3, The duration of mechanical ventilation was from 7 days to 11 years and 5 months (the average was 2.1 years). 4, The microorganism isolated from the aspiration sputum of the VAP patients was Pseudomonas aeruginosa frequently, but it was difficult to determine whether this microorganism was the causative microorganism. Ten strains of Staphylococcus aureus (MRSA seven strains and MSSA three strains) were newly isolated at the same time as VAP and especially in the cases in which these were thought to be causative microrganisms, all the patients died within a short time. 5, Antibiotics were clinically effective for 53.8% of all the VAP patients and carbapenem antibiotics (for example, IPM/CS) were also used for the effective group. 6, Regarding the risk factors for VAP, factors such as the duration of mechanical ventilation, the existence of chronic obstructive pulmonary disease, a hyponutritional state, prior antibiotics, aspiration of gastric contents, histamine-type-2 receptor antagonist, and multiple organ failure showed significant differences and were suspected to be associated with the appearance of VAP.

Adult↗
PubMed1998

Apoptosis following gamma knife radiosurgery in a case of acoustic schwannoma.

A 25-year-old woman with a large acoustic schwannoma underwent surgical excision 18 months after Gamma Knife radiosurgery because of transient expansion of the tumor causing ataxia. Histopathologial investigation by the TUNEL method revealed the presence of some apoptotic cells. The findings were compared with findings from a control group of 7 operated cases where radiosurgery had not been used. There was no apoptosis found in any of these cases. In addition, another case which resulted in a regrowing tumor following Gamma Knife treatment also showed no apoptosis. These findings suggest apoptosis may be a possible mechanism in reducing tumor size following Gamma Knife radiosurgery.

Adult↗
PubMed1998

Influence of interindividual variability of aldose reductase protein content on polyol-pathway metabolites and redox state in erythrocytes in diabetic patients.

OBJECTIVE: To clarify the influence of interindividual difference in the level of aldose reductase on the polyol pathway-related metabolism in diabetic patients. RESEARCH DESIGN AND METHODS: The enzyme protein content was determined by a two-site enzyme-linked immunosorbent assay using monoclonal and polyclonal antibodies to recombinant human aldose reductase in erythrocytes from 35 diabetic patients and 11 healthy volunteers. Patients were stratified into two groups by the median of aldose reductase content, and the erythrocyte sorbitol level, the fructose level, and the lactate-to-pyruvate ratio were compared between the two groups. We also examined the correlation of the enzyme content with these metabolic parameters. RESULTS: The group of patients whose enzyme content was above the median showed a significant increase in the levels of sorbitol (34.7 +/- 4.9 vs. 20.4 +/- 2.0 nmol/g Hb, P < 0.05) and fructose (99.8 +/- 17.2 vs. 45.9 +/- 4.6 nmol/g Hb, P < 0.05), along with an elevated lactate-to-pyruvate ratio (28.6 +/- 6.1 vs. 11.7 +/- 1.2, P < 0.05), compared with patients with low enzyme levels. The aldose reductase content in erythrocytes was well correlated with its activity, and there was a significant correlation between the enzyme content and the erythrocyte sorbitol (r = 0.58, P < 0.001) or fructose (r = 0.57, P < 0.001) levels as well as between the enzyme level and the lactate-to-pyruvate ratio (r = 0.38, P < 0.05). CONCLUSIONS: These results suggest that the interindividual variability of aldose reductase content may contribute tangibly to the polyol-pathway flux and cytoplasmic redox alteration in diabetic patients.

Aldehyde Reductase↗
PubMed1998

Validation of the Michigan Alcoholism Screening Test--Thai version in northeast Thailand.

This study was aimed to validate the Michigan Alcoholism Screening Test-Thai version (MAST-T) which was compared to the psychiatric diagnosis based on DSM-III-R criteria, as a gold standard, among the northeast population of Thailand. Sixty-one pairs of male cases with alcohol use disorders (AUD) and controls were collected through routine examination of psychiatric outpatients, 18-65 years old, who visited the Khon Kaen Psychiatric Hospital or the Northeast Drug Dependence Treatment Center which is located in Khon Kaen province, northeast Thailand between November, 1996 and February, 1997. Controls were matched for each case by sex-age (+/- 5 years)--province--urbanization. They were interviewed using the MAST-T and a structured questionnaire. Receiver operating characteristic analysis revealed that the optimum cutoff point > or = 11 on the MAST-T yields the best sensitivity and specificity (98.4% for each), along with an area under the curve of 0.998, indicating that it was sensitive and specific in discriminating AUD from non-AUD patients. This validation study of the MAST-Thai version underlines its applicability as a screening test for AUD among the northeast male Thai population.

Adolescent↗
PubMed1998

[Predictability of Gleason score and reduction time (tau) of prostatic volume after castration for the prognosis of prostatic cancer].

PURPOSE: The efficacy of the reduction time (tau) after castration as a prognostic factor was examined by comparing to Gleason score. MATERIALS AND METHODS: The change of prostatic volume after castration was observed from the castration to 3 months after in 24 cases of prostatic cancer. Prostatic volume was examined by transrectal ultrasonography of the prostate. Survival curves was calculated by Kaplan-Meier method. Differences among survival curves were analyzed using Cox-Mantel test. RESULTS: tau had a close relationship to the prognosis of each case (Wilcoxon test: p < 0.05, Cox-Mantel test: p < 0.05). Gleason score had a weak relationship to prognosis (Wilcoxon test: N. S., Cox-Mantel test: p < 0.05). CONCLUSIONS: tau was efficient as prognostic factor compared to Gleason score.

Aged↗
PubMed1998

[Myo-inositol].

Explore the source record for details and available documents.

Diabetes Mellitus↗
PubMed1998

The association of plasma micronutrients with the risk of cervical dysplasia in Hawaii.

Limited data from hematological studies suggest that certain nutrients, including carotenoids, tocopherols, and vitamin C, may protect against malignant change in cervical tissue. Recognizing that human papillomavirus (HPV) infection induces most neoplastic transformation of cervical tissue, the authors conducted a case-control study to examine the association of plasma micronutrient concentrations with the risk of cervical dysplasia after careful adjustment for HPV infection, using a sensitive and reliable HPV detection method. The sample included 147 multiethnic women, between 18 and 65 years of age, with biopsy-confirmed squamous intraepithelial lesions (SILs) of the cervix and 191 clinic controls identified between 1992 and 1996. Cases were identified through cytology and pathology logs in three clinics on Oahu, Hawaii. Controls were selected randomly from admission logs of the participating clinics. In-person interviews were conducted in the subjects' homes, and a fasting blood sample was drawn to measure plasma levels of lutein, lycopene, cryptoxanthin, total carotene, retinol, tocopherol, ascorbic acid, and cholesterol. The presence and type of HPV was determined in exfoliated cell samples using PCR dot blot hybridization. Mean plasma lycopene, total cryptoxanthin, and alpha-cryptoxanthin levels were lower among cases than controls. We found an inverse dose-response of alpha-cryptoxanthin, total tocopherol, and alpha-tocopherol to the odds ratios for cervical SIL after adjustment for HPV and other confounders. The odds ratio among women in the highest compared with the lowest quartile was 0.3 (95% confidence interval, 0.1-0.7) for alpha-cryptoxanthin and 0.3 (95% confidence interval, 0.1-0.8) for alpha-tocopherol. Negative trends in the odds ratios were suggested for other carotenoids and vitamin C, but these were weak, and confidence intervals were wide. Our results support existing evidence that high plasma levels of antioxidants may reduce the risk of cervical SILs independent of HPV infection. These findings are significant because diet is potentially modifiable, and nutrition education and dietary intervention might be targeted at specific high-risk groups.

Adolescent↗
PubMed1998

[A basic study of photodynamic therapy of experimental hepatoma with ME 2906].

We have studied effects of photodynamic diagnosis (PDD) and photodynamic therapy (PDT) in hepatoma as confirmed by the existence of hepatoma when using a new photosensitizer mono-L-aspartyl chlorin e6. Japanese white rabbits were selected to perform abdominal incision under intravenous anesthesia and transplant VX2 tumor cells into the liver left lobe for the hepatoma model. Hepatoma of 1 cm in diameter (at one week after transplantation) was used experimentally to radiate a semiconductor laser (664 nm, 200 J/cm2) for treatment.

Animals↗
PubMed1998

[Metabolic changes of aldose and phosphorus metabolites in incubated rabbit lenses--effects of aldose reductase inhibitor].

We measured the metabolic changes in aldose and phosphorus metabolites in rabbit lenses incubated with tissue culture medium 199 (TCM 199) containing 20 mM glucose-1-13C, using 13C, 31P-NMR Spectroscopy (13C, 31P-MRS). Then we investigated the effects of aldose reductase inhibitor (ARI) on those metabolic changes, using the same method. In the incubated rabbit lenses, rapid increases were recognized in sorbitol, sorbitol-3-phosphate, and alpha-glycerophosphate. The levels of glucose, lactate, and adenosin triphosphate (ATP) did not change significantly. Once ARI was added, the levels of sorbitol and sorbitol-3-phosphate were reduced immediately, but the reduction of alpha-glycerophosphate needed some time after the addition of ARI. On the other hand, the levels of lactate increased approximately two-fold, and the levels of glucose and ATP did not change significantly. Considered with our other observations on the metabolic changes in alloxan induced diabetic rabbit lenses, and in rabbit lenses incubated with high concentrations (5-40 mM) of glucose-TCM 199 or 20 mM galactose-TCM 199, these results suggest that aldose reductase not only activates the polyol pathway but also controls the Embden-Meyerhof pathway, energetic metabolic changes, or phospholipid-associated metabolic changes.

Aldehyde Reductase↗
PubMed1998

Polyol pathway hyperactivity is closely related to carnitine deficiency in the pathogenesis of diabetic neuropathy of streptozotocin-diabetic rats.

To investigate the relationship between polyol pathway hyperactivity and altered carnitine metabolism in the pathogenesis of diabetic neuropathy, the effects of an aldose reductase inhibitor, [5-(3-thienyl) tetrazol-1-yl]acetic acid (TAT), and a carnitine analog, acetyl-L-carnitine (ALC), on neural functions and biochemistry and hemodynamic factors were compared in streptozotocin-diabetic rats. Significantly delayed motor nerve conduction velocity, decreased R-R interval variation, reduced sciatic nerve blood flow and decreased erythrocyte 2, 3-diphosphoglycerate concentrations in diabetic rats were all ameliorated by treatment with TAT (administered with rat chow containing 0.05% TAT, approximately 50 mg/kg/day) or ALC (by gavage, 300 mg/kg/day) for 4 weeks. Platelet hyperaggregation activity in diabetic rats was diminished by TAT but not by ALC. TAT decreased sorbitol accumulation and prevented not only myo-inositol depletion but also free-carnitine deficiency in diabetic nerves. On the other hand, ALC also increased the myo-inositol as well as the free-carnitine content without affecting the sorbitol content. These observations suggest that there is a close relationship between increased polyol pathway activity and carnitine deficiency in the development of diabetic neuropathy and that an aldose reductase inhibitor, TAT, and a carnitine analog, ALC, have therapeutic potential for the treatment of diabetic neuropathy.

Acetylcarnitine↗
PubMed1997

Independence of two conformations of sarcoplasmic reticulum Ca2+-ATPase molecules in hydrolyzing acetyl phosphate. A two-pair model of the ATPase structural unit.

The sarcoplasmic reticulum Ca2+-ATPase molecules have been shown to exist in two conformations (A and B) that result from intermolecular interaction of ATPase molecules (Nakamura, J., and Tajima, G. (1995) J. Biol. Chem. 270, 17350-17354). The A form binds two calcium ions noncooperatively, whereas the B form binds the calcium ions cooperatively. Here, we examined the independence of these two forms in the calcium-activated hydrolysis of acetyl phosphate (AcP) under asynchronous and synchronous conditions of their E1-E2 transitions at 0-5 and 25 degrees C. Irrespective of their synchronism and temperature, the two forms hydrolyzed AcP due to calcium that was bound to each of the forms, indicating the independence of the two forms in hydrolyzing AcP. Taking into account the monomer-dimer transition of the ATPase molecules on the sarcoplasmic reticulum membrane accompanying E1-E2 transition of the molecules (Dux, L., Taylor, K. A., Ting-Beall, H. P., and Martonosi, A. (1985) J. Biol. Chem. 260, 11730-11743), the two types of molecules seem to independently carry out such monomer-dimer transition of the same type of molecules. Two pairs, each consisting of the same type of molecules, are suggested to be the structural unit of the ATPase molecules.

Animals↗
PubMed1997

Treatment of surgically induced acute liver failure by transplantation of conditionally immortalized hepatocytes.

The shortage of human livers available for hepatocyte isolation limits its clinical application. The availability of cloned, conditionally immortalized hepatocytes that could be grown in culture but would lose their transformed phenotype and provide metabolic support upon transplantation would greatly facilitate the treatment of acute liver failure. Toward this goal, we transduced isolated Lewis rat hepatocytes using a replication-defective recombinant retrovirus capable of transferring a gene encoding a thermolabile mutant simian virus 40 T antigen (SV40ts). The cloned, immortalized hepatocytes proliferate at 33 degrees C. At the nonpermissive temperatures (37-39 degrees C), they stop growing and exhibit characteristics of differentiated hepatocytes. These cells did not produce tumors when transplanted in mice with severe combined immunodeficiency disease or in syngeneic rats. To induce acute liver failure, Lewis rats were subjected to 90% hepatectomy (Hpx) and given 5% oral dextrose. All rats that did not undergo hepatocyte transplantation died within 96 hr. Fifty percent of rats that received intrasplenic injection of 10 x 10(6) primary Lewis rat hepatocytes (G2, n=6) or 10 x 10(6) SV40ts-conditionally immortalized (SV40ts-ci) hepatocytes (G3, n=8) 1 day before 90% hepatectomy survived, whereas 80% of rats that received an intraperitoneal injection of 200 x 10(6) primary Lewis rat hepatocytes (G4, n=10) or 200 x 10(6) SV40ts-ci hepatocytes (G5, n=10) on the day of hepatectomy survived. Survival after intraperitoneal injection of a cellular homogenate of 200 x 10(6) primary Lewis rat (G7, n=9) or SV40ts-ci hepatocytes (G8, n=10) on the day of Hpx was 33% and 40%, respectively, whereas survival after intraperitoneal injection of 200 x 10(6) Lewis rat bone marrow cells (G6, n=7) was 29%. Thus, transplanted, conditionally immortalized hepatocytes can be as effective as primary hepatocytes in supporting life during acute liver insufficiency. This work represents the first step in developing an hepatocyte cell line that would partially alleviate the organ-donor shortage and could be of potential clinical value.

Animals↗
PubMed1997

Glutathione alters the mode of calcium-mediated regulation of adenylyl cyclase in membranes from mouse brain.

We examined the effect of sulfhydryl compounds on the regulation of adenylyl cyclase by calcium in mouse cerebrum membranes. Isoproterenol-stimulated adenylyl cyclase (IP-AC) activity in the membranes was increased by addition of the optimum concentrations of calcium/calmodulin. However, in the presence of 0.01-0.07 mM glutathione (GSH), calcium/calmodulin inhibited the activity. At high concentrations of GSH (1-10 mM), the IP-AC activity was stimulated by calcium/calmodulin to a greater extent than that in the control (no GSH). Cysteine at less than 1.7 mM induced a similar inhibition of the IP-AC activity, but dithiothreitol did not. The activity of IP-AC measured in the absence of calmodulin decreased when calcium levels were greater than 300 microM. GSH at 0.05 mM enhanced the calcium-dependent inhibition (22% inhibition by 200 microM calcium), while 10 mM GSH lowered it. Calmodulin itself had no significant effect on the IP-AC activity, irrespective of the concentrations of GSH involved. It caused a small increase in the IP-AC activity that had been reduced by the presence of calcium and GSH. These results indicate that the redox status of sulfhydryls in adenylyl cyclase plays an important role in the calcium-mediated regulation of the enzyme. The enzyme becomes much more sensitive to the calcium-dependent inhibition after partial reduction of the sulfhydryls via the particular mode of reactin.

Adenylyl Cyclase Inhibitors↗