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Biomedical subjects

T Yoshida

Publications and source records attributed to T Yoshida.

At least 73 records · Page 4Linked to original sources
PubMed2004

Lancefield group C Streptococcus dysgalactiae infection responsible for fish mortalities in Japan.

A Lancefield serological group C Streptococcus sp. was isolated from cultured amberjack, Seriola dumerili Risso, and yellowtail, Seriola quinqueradiata Temminck and Schlegel, immunized with Lactococcus garvieae commercial vaccines in Japan. The isolated bacteria were Gram-positive cocci, auto-aggregating in saline, morphologically long chains in growth medium, catalase negative and alpha-haemolytic on blood agar. An almost complete gene sequence of the 16S rDNA of two isolates was determined and compared with that of bacterial strains in the database. The isolates were identified as Streptococcus dysgalactiae based on the results of the 16S rDNA sequence, the bacteriological properties and the Lancefield serological grouping. Oligonucleotide primers specifically designed for the 16S-23S rDNA intergenic spacer region of S. dysgalactiae amplified a gene from all the fish isolates, as well as the type strains alpha-haemolytic S. dysgalactiae subsp. dysgalactiae ATCC430738 and beta-haemolytic S. dysgalactiae subsp. equisimilis ATCC35666, but not those of S. equi ATCC33398, Lactococcus garvieae ATCC43921 and L. garvieae KG9408. The severe necrotic lesions of the caudal peduncle seen in experimentally infected fish were similar to those seen in naturally infected fish.

Animals↗
PubMed2004

Effects of electroconvulsive therapy on frontal white matter in late-life depression: a diffusion tensor imaging study.

This study was conducted to elucidate the effects of electroconvulsive therapy (ECT) on frontal white matter in late-life depressed patients. Diffusion tensor imaging was performed on 8 late-life depressed patients and 12 healthy age-matched controls. The patients were scanned before and after a course of ECT. Fractional anisotropy (FA) was determined in the frontal and temporal regions and the corpus callosum. A significant white matter FA reduction was found in widespread frontal and temporal brain regions in patients with depression before ECT treatment compared with controls. A significant increase in frontal white matter FA was seen following ECT treatment. A course of bilateral ECT ameliorated white matter integrity in frontal brain regions. This suggests a strong relationship with the antidepressant action of ECT.

Age of Onset↗
PubMed2004

Interaction between cell and extracellular matrix in heart disease: multiple roles of tenascin-C in tissue remodeling.

The heart remodels myocardial tissue in physiological and pathological response. The cell-extracellular matrix (ECM) interaction provides not only structural and mechanical support but also important biological signaling during tissue remodeling. Among various ECM molecules, tenascin-C (TNC) is well known as a regulator of multiple cellular functions during embryogenesis, wound healing or cancer progression. In the heart, TNC appears in several important steps of embryonic development such as the initial differentiation of cardiomyocytes or coronary vasculo/angiogenesis, but it is not detected in a normal adult myocardium. However, TNC is found to re-express after myocardial injury and may regulate cellular behavior during tissue remodeling by modulating the attachment of cardiomyocytes to connective tissue, by enhancing migration and differentiation of myofibroblasts, and by inducing matrix metallo-proteinases. TNC also interacts with other ECM molecules and may modulate progression of fibrosis. Furthermore, transient and site specific expression of TNC closely associated with myocardial injury and inflammation suggests not only its key roles during tissue remodeling but also that TNC can be a marker for myocardial disease activity.

Animals↗
PubMed2004

[Off-pump coronary artery bypass via left thoracotomy in patient with infective pancreatic fistula after surgery for bile duct carcinoma; report of a case].

A 62-year-old man with infective pancreatic fistula after surgery for bile duct carcinoma underwent off-pump coronary artery bypass (OPCAB) through left thoracotomy to avoid the use of cardiopulmonary bypass and the postoperative mediastinitis, since this patient has infective pancreatic fistula close to the xiphoid process. The coronary arterial revascularizations were performed: left internal thoracic artery to left anterior descending branch and saphenous vein graft to descending thoracic aorta. The aortic mechanical anastomosis device, aortic connector, was utilized the proximal anastomosis of saphenous vein graft so as to avoid aortic clamp, while the distal anastomoses were completed with stabilizer and apical retraction device. Postoperative angiogram showed both grafts were patent. No signs of infection or recurrence of malignant neoplasm was observed. OPCAB via left thoracotomy is one of useful options for patients in whom median sternotomy is not suitable approach for myocardial revascularizations.

Bile Duct Neoplasms↗
PubMed2003

Matrix metalloproteinase-7 and matrix metalloproteinase-9 are associated with unfavourable prognosis in superficial oesophageal cancer.

If oesophageal carcinoma is detected in the superficial stage, the prognosis is better than for advanced oesophageal carcinoma. But the factors which predict the prognosis and treatment policy remain unclear. Matrix metalloproteinase-7 (MMP-7) and matrix metalloproteinase-9 (MMP-9) have been reported to have close associations with tumour invasion and metastasis. In this study, we retrospectively studied the relations between MMP-7 and MMP-9 expression in immunohistochemistry, clinicopathologic factors, and prognosis in 55 superficial oesophageal carcinomas. MMP-7 and MMP-9 expression occurred in 23.6% and 47.3% of the patients, respectively. MMP-7 expression was significantly correlated with the presence of nodal metastasis (P=0.004). MMP-9 expression was significantly correlated with the depth of tumour invasion (P=0.004), lymphatic permeation (P=0.001), nodal metastasis (P=0.049), and pathologic differentiation grade (P=0.003). By the log-rank test, MMP-7 expression and MMP-9 expression on the invasive front were related to the prognosis. In multivariate analysis, MMP-9 expression on the invasive front was an independent prognostic indicator. The combined expression of MMP-7 and MMP-9 may be a good marker for the degree of malignancy of oesophageal cancer and for the presence of lymphatic metastasis.

Adenocarcinoma↗
PubMed2003

Proinsulin C-peptide increases nitric oxide production by enhancing mitogen-activated protein-kinase-dependent transcription of endothelial nitric oxide synthase in aortic endothelial cells of Wistar rats.

AIMS/HYPOTHESIS: Recent studies have suggested that proinsulin C-peptide improves vascular functions, possibly through nitric oxide (NO) production. To clarify the molecular mechanisms of vascular NO production induced by C-peptide, we examined the effects of C-peptide on NO production and NO synthase expression in rat aortic endothelial cells in connection with mitogen-activated protein kinase (MAPK) activation. METHODS: Aortic endothelial cells were isolated from female Wistar rats, cultured to confluence, and serum-starved for 24 h before treatment with C-peptide. Nitric oxide production was measured by the DAF-2 fluorescence dye method and relative amounts of endothelial nitric oxide synthase (eNOS) protein and its mRNA were semi-quantified by western blot and RT-PCR analyses respectively. Activation of MAPK was estimated by western blot detection of activity-related phosphorylation and in vitro kinase assay. RESULTS: Stimulation of cells with C-peptide for 3 h doubled NO production, which was suppressed by the NO synthase inhibitor, N(G)-nitro- L-arginine methyl ester (L-NAME). Stimulation also increased mRNA and protein contents of eNOS in a manner sensitive to the transcription inhibitor actinomycin D. It did not affect inducible NO synthase mRNA. C-peptide also induced rapid phosphorylation and activation of extracellular signal-regulated kinase (ERK, also known as p44/42MAPK), but not of p38MAPK. In cells pretreated with the ERK inhibitor PD98059 the C-peptide-elicited increase of NO production and eNOS was abrogated in a dose-dependent manner; suppression of ERK phosphorylation induced by C-peptide also occurred. CONCLUSIONS/INTERPRETATION: Our results show that C-peptide increases NO production by increasing eNOS protein contents through ERK-dependent up-regulation of eNOS gene transcription. This could explain some actions of C-peptide on the vasculature, indicating a pivotal role for C-peptide in vascular homeostasis.

Animals↗
PubMed2003

Possible alternative carcinogenesis pathway featuring microsatellite instability in colorectal cancer stroma.

Differential microsatellite instability (MSI) in tumour epithelial and stromal compartments has not been well examined for colorectal cancers. Using laser-captured microdissection, separate specimens of these compartments of 40 sporadic colorectal cancers were sampled and MSI was tested with four markers. To examine the relation between the MSI phenotype in the stroma and other genetic events and histopathological features, p53 and K-ras gene mutations were analysed, and the expression of p53, hMLH1, and hMSH2 protein was determined by immunohistochemistry. Microsatellite instability positive results were obtained for both epithelium (34%) and stromal tissue (41%). While MSI in epithelium correlated with differentiation and Dukes' stage, that in stroma demonstrated an inverse relation, being particularly frequent in well-differentiated adenocarcinomas (54%) and Dukes' A lesions (55%). Further, a significant inverse correlation between p53 protein overexpression in the epithelium and MSI in the stroma was found (P=0.02475). The results suggest an alternative pathway of carcinogenesis involving stromal genetic instability in the development of colorectal cancers.

Adaptor Proteins, Signal Transducing↗
PubMed2003

Metallic behavior of lightly doped La2-xSrxCuO4 with a Fermi surface forming an arc.

Lightly doped La2-xSrxCuO4 in the so-called "insulating" spin-glass phase has been studied by angle-resolved photoemission spectroscopy. We have observed that a "quasiparticle" (QP) peak crosses the Fermi level in the node direction of the d-wave superconducting gap, forming an "arc" of Fermi surface, which explains the metallic behavior at high temperatures of the lightly doped materials. The QP spectral weight of the arc smoothly increases with hole doping, which we attribute to the n approximately x behavior of the carrier number in the underdoped and lightly doped regions.

Journal Article↗
PubMed2003

epsilon-Poly-L-lysine: microbial production, biodegradation and application potential.

epsilon-Poly-L-lysine (epsilon-PL) is a homo-poly-amino acid characterized by the peptide bond between the carboxyl and epsilon-amino groups of L-lysine. epsilon-PL shows a wide range of antimicrobial activity and is stable at high temperatures and under both acidic and alkaline conditions. The mechanism of the inhibitory effect of epsilon-PL on microbial growth is the electrostatic adsorption to the cell surface of microorganisms on the basis of its poly-cationic property. Due to this antimicrobial activity, epsilon-PL is now industrially produced in Japan as a food additive by a fermentation process using Streptomyces albulus. In spite of the practical application of epsilon-PL, the biosynthetic mechanisms of epsilon-PL have not been clarified at all. epsilon-PL producers commonly possess membrane-bound epsilon-PL-degrading aminopeptidase, which might play a role in self-protection.

Bacteria↗
PubMed2003

Regioselective hydroxylation of quinolinic acid, lutidinic acid and isocinchomeronic acid by resting cells of pyridine dicarboxylic acid-degrading microorganisms.

Microorganisms aerobically degrading quinolinic acid, lutidinic acid or isocinchomeronic acid were isolated and the microbial regioselective hydroxylation of these pyridine dicarboxylic acids was studied. Alcaligenes sp. UK21 cells converted quinolinic acid into 6-hydroxypicolinic acid, suggesting the involvement of two enzyme reactions catalyzing hydroxylation at position C6 and decarboxylation at position C3 of quinolinic acid. Resting cells of Alcaligenes sp. UK21 accumulated 94.9 mM 6-hydroxypicolinic acid (13.2 g l(-1)), with a 96% molar conversion yield by 48 h incubation. Rhizobium sp. LA17 and Hydrogenophaga sp. IMA01 catalyzed the regioselective hydroxylation of lutidinic acid and isocinchomeronic acid into 6-hydroxylutidinic acid and 6-hydroxyisocinchomeronic acid, respectively. 6-Hydroxylutidinic acid accumulated up to 95.4 mM (17.5 g l(-1)) by 24 h incubation in the resting cells reaction, using Rhizobium sp. LA17, with a 99% molar conversion yield. Resting cells of Hydrogenophaga sp. IMA01 produced 88.7 mM 6-hydroxyisocinchomeronic acid (16.2 g l(-1)) by 24 h incubation, with a 81% molar conversion yield.

Alcaligenes↗
PubMed2003

Characterization and identification of genes essential for dimethyl sulfide utilization in Pseudomonas putida strain DS1.

Microbial dimethyl sulfide (DMS) conversion is thought to be involved in the global sulfur cycle. We isolated Pseudomonas putida strain DS1 from soil as a bacterium utilizing DMS as a sole sulfur source, and tried to elucidate the DMS conversion mechanism of strain DS1 at biochemical and genetic level. Strain DS1 oxidized DMS to dimethyl sulfone (DMSO(2)) via dimethyl sulfoxide, whereas the oxidation was repressed in the presence of sulfate, suggesting that a sulfate starvation response is involved in DMS utilization by strain DS1. Two of the five DMS-utilization-defective mutants isolated by transposon 5 (Tn 5) mutagenesis had a Tn 5 insertion in the ssuEADCBF operon, which has been reported to encode a two-component monooxygenase system (SsuED), an ABC-type transporter (SsuABC), and a small protein (SsuF), and also to play a key role in utilization of sulfonates and sulfate esters in another bacterium, P. putida strain S-313. Disruption of ssuD and SsuD enzymatic activity demonstrated that methanesulfonate is a metabolic intermediate of DMS and desulfonated by SsuD. Disruption of ssuC or ssuF also led to a DMS-utilization-defective phenotype. Another two mutants had a defect in a gene homologous to pa2354 from P. aeruginosa PAO1, which encodes a putative transcriptional regulator, while the remaining mutant had a defect in cysM encoding O-acetylserine (thiol)-lyase B.

Base Sequence↗
PubMed2003

Weber-Christian disease presenting with ocular manifestations.

A Japanese patient with Weber-Christian disease (WCD) presenting with ocular symptoms is reported. Panniculitis in the retrobulbar fat was diagnosed according to the histological findings from biopsy specimens, and improved over a month under steroid administration. Only three patients showing ocular manifestations have previously been reported. Panniculitis was in the late stage and a medium dose of prednisolone was effective in this patient. A biopsy of the orbital fat was useful for diagnosis. However, it is important to recognise that the stage of inflammation varies according to the fat tissue involved by WCD.

Aged↗
PubMed2003

Unicompartmental knee arthroplasty for osteoarthritis of the knee: remaining postoperative flexion contracture affecting overall results.

The success rate of unicompartmental knee arthroplasty has been variable, and controversy still surrounds its use. Achieving good functional results from this surgery may require understanding surgical principles, precise operative techniques, and careful patient selection. This paper evaluates clinical results and factors influencing postoperative knee function after unicompartmental knee arthroplasty. The follow-up assessment of 109 knees that underwent unicompartmental knee arthroplasty showed that 90 of 109 knees were classified as excellent or good (82.6%) using the Hospital for Special Surgery knee scoring system. In the excellent group (54 knees), 52% of the postoperative, standing femorotibial angles converged on a range of 170 degrees to 175 degrees with a mean of 174 degrees +/- 4 degrees. The knees with residual flexion contracture after surgery showed poorer clinical results. Therefore, complete elimination of the flexion contracture during surgery is considered mandatory.

Arthroplasty, Replacement, Knee↗
PubMed2003

Adenovirus-mediated gene transfer of interferon alpha improves dimethylnitrosamine-induced liver cirrhosis in rat model.

Several lines of evidence suggest that interferon (IFN)-alpha is effective in suppression of liver cirrhosis (LC) as well as hepatitis C virus (HCV) infection, which is a major cause of LC in Japan. However, IFN-alpha often causes systemic toxicity such as flu-like symptoms, which precludes the IFN-alpha dose escalation required for clinical efficacy. Since IFN-alpha is rapidly degraded in the blood circulation, only a small amount of subcutaneously injected IFN-alpha protein can reach the target organ, the liver. It is expected that on-site IFN-alpha production in the liver overcomes the limitation of the conventional parenteral IFN-alpha administration. An adenovirus vector expressing the rat IFN-alpha gene (AxCA-rIFN) was injected intravenously into rats with dimethylnitrosamine-induced LC. While the subcutaneous IFN-alpha protein injection led to a transient elevation of the cytokine both in the liver and serum, the vector-mediated IFN-alpha gene transduction induced a significant amount of IFN-alpha detected in the liver but not in the serum. The injection of AxCA-rIFN prevented the progression of the rat LC, and improved the survival rate of the treated rats. Although no significant toxicity was noted in the animals, we showed that IFN-alpha gene expression in the liver can be efficiently downregulated by the Cre/loxP-mediated shut-off system, in case the IFN-alpha overdose becomes a problem. The study suggested for the first time the advantage and feasibility of IFN-alpha gene therapy for LC.

Adenoviridae↗
PubMed2003

Association between weight fluctuation and fasting insulin concentration in Japanese men.

OBJECTIVE: To investigate whether long-term weight fluctuation is associated with the fasting serum insulin concentration. DESIGN AND SUBJECTS: Weight histories of 1932 male Japanese workers aged 40-59 y were analyzed in relation to their current fasting serum insulin concentration. MEASUREMENTS: Individual weight fluctuation was calculated by root mean square error (RMSE) along the linear regression line of weight measured at five to six different ages. RESULTS: The mean RMSE and fasting insulin concentration were 1.22 kg and 4.5 microU/ml, respectively. The multivariate adjusted insulin level became higher with the increase in weight fluctuation. Subanalysis stratified by current body mass index (BMI) showed that the multivariate adjusted insulin level in individuals in the top quartile of fluctuation was 4.3 microU/ml, against 3.9 microU/ml in those in the bottom quartile (P=0.018, analysis of covariance (ANCOVA)) in the normal weight subgroup with current BMI below 25 kg/m(2). In the overweight subgroup with BMI 25 kg/m(2) or above, the level was 6.9 microU/ml in individuals in the top quartile and 6.2 microU/ml in those in the bottom quartile (P=0.054, ANCOVA). CONCLUSION: The results suggest that weight fluctuation increases the risk of developing hyperinsulinemia. Prospective observations together with measurement of changes in adiposity are needed for confirmation.

Adult↗