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Biomedical subjects

M Taniguchi

Publications and source records attributed to M Taniguchi.

At least 325 records · Page 18Linked to original sources
PubMed1998

Cloning and expression of the gene encoding flavodoxin from Desulfovibrio vulgaris (Miyazaki F).

The gene encoding a flavodoxin of Desulfovibrio vulgaris (Miyazaki F) was cloned, and overexpressed in Escherichia coli. A 1.6-kbp DNA fragment, isolated from D. vulgaris (Miyazaki F) by double digestion with SalI and EcoRI, contained the flavodoxin gene and its regulatory region. An expression system for the flavodoxin gene under control of the T7 promoter was constructed in E. coli. The purified protein was soluble and exhibited a characteristic visible absorption spectrum. HPLC analysis of the recombinant flavodoxin revealed the presence of an identical FMN to that found in the native D. vulgaris flavodoxin, and its dissociation constant with FMN was determined to be 0.38 nM. In vitro H2 reduction analysis indicated that the recombinant flavodoxin is active, and its redox potential was determined to be E1 = -434 and E2 = -151 mV using methyl viologen and 2-hydroxy-1,4-naphthoquinone, respectively. Its redox behavior was also examined with the recombinant flavodoxin adsorbed onto a graphite electrode. The mutant, A16E, was also produced, which revealed the feature of a conserved Glu residue at the surface of the molecule.

Base Sequence↗
PubMed1998

Prediction of efficacy of interferon treatment of chronic hepatitis C by multivariate analysis and a new classification.

One hundred and fifteen patients with chronic hepatitis C were administered interferon (IFN) and classed into two groups: (i) complete responders (CR), HCV-RNA continuously negative 1 year after treatment; and (ii) non-responders (NR), positive 1 year after treatment. Multivariate analysis comprised eight variables: age, sex, transfusion history, alanine aminotransferase level, viral genotype, level of viremia, type of IFN, and total amount of IFN. The HCV-RNA level was correlated with complete response (P = 0.0175). Liver biopsy specimens were classified into four grades and stages according to the measure of severity and the extent of fibrosis, respectively. There was no correlation between the efficacy rate and grading. However, in staging there was a difference in the efficacy of IFN between stages 1 or 2, and stage 3 (0.05 < P < 0.1 and 0.01 < P < 0.025, respectively). Of the CR patients, 0% (0/5) were at stage 0 (no fibrosis); 27.5% (22/80) at stage 1 (mild); 42.9% (6/14) at stage 2 (moderate); and 6.3% (1/16) at stage 3 (severe fibrosis). Thus the new classification would be useful in predicting roughly the efficacy of IFN.

Adolescent↗
PubMed1998

Farnesol-induced generation of reactive oxygen species via indirect inhibition of the mitochondrial electron transport chain in the yeast Saccharomyces cerevisiae.

The mechanism of farnesol (FOH)-induced growth inhibition of Saccharomyces cerevisiae was studied in terms of its promotive effect on generation of reactive oxygen species (ROS). The level of ROS generation in FOH-treated cells increased five- to eightfold upon the initial 30-min incubation, while cells treated with other isoprenoid compounds, like geraniol, geranylgeraniol, and squalene, showed no ROS-generating response. The dependence of FOH-induced growth inhibition on such an oxidative stress was confirmed by the protection against such growth inhibition in the presence of an antioxidant such as alpha-tocopherol, probucol, or N-acetylcysteine. FOH could accelerate ROS generation only in cells of the wild-type grande strain, not in those of the respiration-deficient petite mutant ([rho0]), which illustrates the role of the mitochondrial electron transport chain as its origin. Among the respiratory chain inhibitors, ROS generation could be effectively eliminated with myxothiazol, which inhibits oxidation of ubiquinol to the ubisemiquinone radical by the Rieske iron-sulfur center of complex III, but not with antimycin A, an inhibitor of electron transport that is functional in further oxidation of the ubisemiquinone radical to ubiquinone in the Q cycle of complex III. Cellular oxygen consumption was inhibited immediately upon extracellular addition of FOH, whereas FOH and its possible metabolites failed to directly inhibit any oxidase activities detected with the isolated mitochondrial preparation. A protein kinase C (PKC)-dependent mechanism was suggested to exist in the inhibition of mitochondrial electron transport since FOH-induced ROS generation could be effectively eliminated with a membrane-permeable diacylglycerol analog which can activate PKC. The present study supports the idea that FOH inhibits the ability of the electron transport chain to accelerate ROS production via interference with a phosphatidylinositol type of signal.

Electron Transport↗
PubMed1998

Expression of neuropsin mRNA in the mouse embryo and the pregnant uterus.

Neuropsin is a novel serine protease whose mRNA is expressed in the mouse central nervous system. We examined the expression of neuropsin mRNA during embryonic development using Northern and in situ hybridization in non-neural tissues. The pregnant uterus showed strong expression of neuropsin mRNA, whereas the nonpregnant uterus did not express this mRNA. Expression was first detected in the primary decidual zone at 5.5 days post coitum and was maximized at 10 days post coitum, decreasing remarkably thereafter. During mouse organogenesis, neuropsin expression was observed in the developing heart, lung, thymus, pituitary, choroid plexus, and epithelial linings of the skin, oral cavity, tongue, esophagus, and forestomach. In adult mouse organs, neuropsin mRNA was expressed in epithelial tissues covered by keratinocytes with moderate density, whereas low expression was observed in lung, thymus, and spleen. Neuropsin mRNA expression in developing organs and adult keratinocytes suggests that neuropsin is associated with extracellular matrix modifications and cell migrations.

Animals↗
PubMed1998

Production of a mixture of antimicrobial organic acids from lactose by co-culture of Bifidobacterium longum and Propionibacterium freudenreichii.

The antimicrobial activities of standard solutions of three organic acids (lactic, acetic, and propionic acids) were compared using Micrococcus luteus, Pseudomonas sp. and Staphylococcus aureus as test microorganisms. At the same concentrations of the undissociated form, the antimicrobial activities of acetic and propionic acids were higher than that of lactic acid, irrespective of test microorganisms. In a single cultivation of Bifidobacterium longum, a mixture of lactic (17 g/l) and acetic (20 g/l) acids was produced from 50 g/l lactose and its antimicrobial activities against M. luteus, Pseudomonas sp., and S. aureus correspond to that of 32, 19, and 25 g/l of acetic acid, respectively. To increase the total antimicrobial activity, a co-culture of B. longum and Propionibacterium freudenreichii, in which lactic acid produced once from lactose by B. longum was converted to acetic and propionic acids by P. freudenreichii, was done using TPY medium containing commercially available peptones as a nitrogen source. By the sequential conversion of lactose using the two microorganisms, the culture supernatant containing a mixture of acetic (27 g/l) and propionic (13 g/l) acids without lactic acid was produced. The antimicrobial activities of the mixture against M. luteus, Pseudomonas sp., and S. aureus were 35, 30, and 26 g/l as a concentration of acetic acid, respectively, higher than that obtained in the cultivation of B. longum alone. When the medium containing an enzymatic hydrolyzate of whey proteins with a protease was used in the co-culture of B. longum and P. freudenreichii, the culture supernatant containing the mixture of organic acids was also obtained in the same manner as the co-culture using TPY medium and the activities were 43, 29, and 29 g/l as a concentration of acetic acid for M. luteus, Pseudomonas sp. and S. aureus, respectively.

Acetic Acid↗
PubMed1998

[Clinical significance of serum lipoprotein(a) in elderly patients with aortic valve sclerosis].

BACKGROUND: Calcified aortic value disease is increasing with explosively in the elderly. Elevated serum lipoprotein(a) (Lp(a) plays an important role in the pathogenesis of atherosclerosis. Thus, we investigated the relationship between aortic valve sclerosis and serum Lp(a) levels in elderly patients. METHODS: Echocardiography was performed in 97 subjects (77 +/- 7 years, 48 males and 49 females), Lp(a), fasting plasma glucose, and blood pressure were measured at the time of the study. Aortic valve sclerosis was assessed using echocardiography. RESULTS: Aortic valve sclerosis was observed in 63 patients (sclerosis group; 24 males and 39 females) and not in 34 subjects (non-sclerosis group; 24 males and 10 females). Univariable analysis revealed that age, Lp(a) level, and the number of females were higher in the sclerosis group than in the non-sclerosis group (age; 78 +/- 7 vs 74 +/- 7 years, p = 0.0090, Lp(a); cholesterol, triglyceride, and fasting blood glucose did not seem to affect aortic valve sclerosis. In all of 9 patients with serum Lp(a) greater than 60mg/dl aortic valve sclerosis was present. In discriminative analysis, gender (female) (lambda = 0.9038, p = 0.0020) and Lp(a) (lambda = 0.8316, p = 0.0053) were related to aortic valve sclerosis. CONCLUSION: Elevated serum Lp(a) was observed in elderly patients with aortic valve sclerosis.

Aged↗
PubMed1998

[Changes in blood polyamine levels following chemotherapy in patients with invasive urinary bladder carcinoma].

BACKGROUND: Polyamines are recognized as cell growth factors. We attempted to determine whether blood polyamines are useful biochemical makers for monitoring the efficacy of the chemotherapy on bladder tumors. METHODS: The blood concentrations of three polyamines, diamine, spermidine and spermine, were determined in 31 patients with invasive urinary bladder carcinoma, following chemotherapy with cisplatin, methotrexate and pirarubicin. Clinical response was evaluated by CT after 3 weeks. In 26 patients who underwent subsequent surgical therapy, the effectiveness of the chemotherapy were histopathologically evaluated by a pathologist according to the response criteria for bladder cancer treatment. RESULTS: Mean regression rate in the size of the tumor after the chemotherapy was 40.8%. Of 31 patients, clinical CR was observed in 2, PR in 11, and NC in 18. Of 26 patients who were histopathologically evaluated, grade 3 was observed in 5, grade 2 in 4, grade 1b in 4, grade 1a in 12, and grade 0 in 1. One week after chemotherapy, the levels of spermine and total polyamine in the patients with CR and PR were significantly lower than those in the patients with NC. Similarly one week after chemotherapy, the levels of spermine and total polyamine in the patients with grade 3 and grade 2 were significantly lower than those in the patients with grade 1b, grade 1a and grade 0. CONCLUSION: The study suggested that the levels of blood polyamines could be used as biochemical markers for monitoring the efficacy of the chemotherapy on bladder tumors.

Adenocarcinoma↗
PubMed1998

The mode of action of AKD-2C, an antifungal antibiotic from Streptomyces sp. OCU-42815.

The mechanism of the antifungal action of AKD-2C was studied by using Torulaspora delbrueckii IFO 1621 as a model. AKD-2C slightly inhibited the incorporation of radioactive precursors into protein, RNA and lipid, but not into DNA. On the other hand, AKD-2C greatly enhanced the leakage of K+ ions from treated cells and showed a potent effect on liposomal glucose leakage. Using electron microscopic studies, though drastic morphological changes were not observed, an increase in cell membrane irregularities and swelling of the mitochondria caused by AKD-2C were demonstrated. These results suggest that the antifungal action of AKD-2C is due to effects on the yeast cell membrane.

Antifungal Agents↗
PubMed1998

Fluorine-18-FDG PET imaging is negative in bronchioloalveolar lung carcinoma.

UNLABELLED: The goals of our study were to establish PET accuracy with 18F-fluorodeoxyglucose (FDG) in finding localized formations of bronchioloalveolar lung carcinoma (BAC) and to investigate the correlation between FDG uptake and the degree of cell differentiation in adenocarcinoma of the lung. MATERIALS: Twenty-nine patients with 30 adenocarcinomas of the lung (7 bronchioloalveolar lung carcinomas, 9 well differentiated, 2 well-moderately differentiated, 11 moderately differentiated and 1 poorly differentiated) were studied. All patients underwent thoracotomies within 4 wk after the FDG PET study. For qualitative analysis, the degree of FDG activity in the tumors was visually scored using a five-point grading system: 0 = same to background activity, 1 = less than mediastinal blood-pool activity, 2 = same to mediastinal blood-pool activity, 3 = slightly greater than mediastinal blood-pool activity and 4 = substantially greater than mediastinal blood-pool activity. Foci of activity with Grades 2-4 were considered tumors. For semiquantitative analysis, standardized uptake values (SUV) were calculated. RESULTS: In 7 BACs, 4 lesions (57%) showed negative results on FDG PET, while in 23 non-BACs, only 1 lesion (4%), which was a well-differentiated adenocarcinoma showed a negative result. BACs' mean visual score (1.43 +/- 1.27) was significantly lower than that of non-BACs (3.17 +/- 1.03) (p = 0.001). The BACs' mean SUV (1.36 +/- 0.821) was significantly lower than that of well-differentiated adenocarcinomas (2.92 +/- 1.28) (p = 0.014); the mean SUV of well-differentiated adenocarcinomas was significantly lower than that of moderately differentiated adenocarcinomas (4.63 +/- 1.86) (p = 0.031). No significant differences were apparent in average size among these three histologic types. CONCLUSION: A correlation was observed between FDG uptake and the degree of cell differentiation in adenocarcinoma of the lung. FDG PET may show negative results for BAC.

Adenocarcinoma↗
PubMed1998

[Fleroxacin treatment for acute uncomplicated cystitis in women: comparison of 3-day and 7-day therapy].

The clinical efficacy of fleroxacin (FLRX), a new fluoroquinolone, for acute uncomplicated cystitis (AUC) in women was assessed. Two regimens, 3-day and 7-day courses of FLRX, 200 mg once a day, were compared. Clinical and bacteriological efficacy were evaluated after the therapy, and recurrence rate was evaluated 1 week and 4 weeks after termination of the therapy. Of 136 registered subjects, 35 in the 3-day group and 47 in the 7-day group were evaluated. According to the criteria of Japanese UTI Committee (3rd edition), the rate of excellent results was significantly higher in the 7-day group (78.9%) than in the 3-day group (48.6%), but the overall clinical efficacy rate was similar being 100% and 97.9%, respectively. Although no recurrence was seen 1 week after the therapy in either group, recurrence was seen in 14.3% and 7.4% of the cases in the 3-day and 7-day groups, respectively, 4 weeks after the therapy. Adverse reactions were observed in 2 and 3 cases in the 3-day and 7-day groups, respectively. Both 3-day and 7-day regimens of FLRX treatment showed good efficacy. Although the 7-day treatment was superior to the 3-day treatment as to high rate of excellent results and low rate of recurrence, the 3-day treatment was concluded to be sufficient for AUC.

Adult↗