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Biomedical subjects

H Watanabe

Publications and source records attributed to H Watanabe.

At least 253 records · Page 14Linked to original sources
PubMed2001

[Importance of a cleaning in upper airways by using povidone iodine for the prevention of nosocomial pneumonia].

We investigated the efficacy of infection control measures against nosocomial pneumonia in geriatric wards. Cases with nosocomial pneumonia were retrospectively analyzed between January 1991 and March 1995. The study period was divided into four annual periods (periods 1, 2, 3 and 4). Period 1, January to December 1991, was applied as the cotrol. We investigated patients with nosocomial pneumonias in geriatric wards (190 beds) of AINO Memorial Hospital, affiliated with Nagasaki University. During the study period, nosocomial pneumonia significantly diminished. (period 1 vs periods 2, 3 and 4, p < 0.05, p < 0.05, p < 0.05, respectively). Major causative organisms of nosocomial pneumonia were MRSA and Pseudomonas aeruginosa. During the four periods, a significant reduction in cases with MRSA- and P. aeruginosa-induced nosocomial pneumonia was observed (MRSA: period 1 vs periods 2, 3 and 4, p < 0.05, p < 0.05, p < 0.01, respectively; P. aeruginosa: period 1 vs period 3, p < 0.01, period 2 vs periods 3 and 4, p < 0.01, p < 0.05, respectively). On the other hand, the improvement of decubitus ulcers was associated with a significant reduction in nosocomial pneumonia (period 1 vs. periods 2 and 3, p < 0.05 and p < 0.05, respectively). In conclusion, stringent infection control programs, including a cleaning in the upper airways by povidone iodine, are necessary in geriatric wards to reduce and prevent nosocomial pneumonia.

Aged↗
PubMed2001

Antibiotic susceptibilities of Salmonella enterica serovar Typhi and S. enterica serovar Paratyphi A isolated from patients in Japan.

The antibiotic susceptibilities of 62 strains of Salmonella enterica serovar Typhi and 37 strains of S. enterica serovar Paratyphi A were investigated with 18 antibiotics. Eighteen S. enterica serovar Typhi isolates and five S. enterica serovar Paratyphi A isolates were resistant to one or more antimicrobial agents, among which 10 S. enterica serovar Typhi isolates were nalidixic acid resistant and also showed decreased ciprofloxacin susceptibility.

Anti-Bacterial Agents↗
PubMed2001

Low concentrations of mupirocin in the pharynx following intranasal application may contribute to mupirocin resistance in methicillin-resistant Staphylococcus aureus.

We describe a patient with methicillin-resistant Staphylococcus aureus (MRSA) colonizing the pharynx. The MIC of mupirocin was 0.25 microg/ml before treatment and increased after treatment to 8 microg/ml. Using pulsed-field gel electrophoresis, we confirmed that the genotypes of MRSA that colonized the pharynx before and after the use of mupirocin were identical. We measured the delivery of mupirocin to the pharynx in three normal volunteers and two patients. Low concentrations of mupirocin were present in the pharynx in all cases 10 min to 3 days after intranasal application. Our data suggested that low concentrations of the drug in the pharynx after intranasal application of mupirocin ointment might explain the selection of mupirocin resistance in MRSA.

Aged↗
PubMed2001

Characterization of multidrug-resistant Salmonella enterica serovar Typhimurium isolated in Japan.

A total of 221 isolates of multidrug-resistant Salmonella enterica serovar Typhimurium in Japan were characterized in the present study. The results revealed that clonal serovar Typhimurium definitive phage type 104 strains prevailed and that these strains had drug resistance patterns, integron types, and pulsed-field gel electrophoresis patterns similar to those predominant among isolates in Western countries.

Animals↗
PubMed2001

Roles of disulfide linkage and calcium ion-mediated interactions in assembly and disassembly of virus-like particles composed of simian virus 40 VP1 capsid protein.

The simian virus 40 capsid is composed of 72 pentamers of VP1 protein. Although the capsid is known to dissociate to pentamers in vitro following simultaneous treatment with reducing and chelating agents, the functional roles of disulfide linkage and calcium ion-mediated interactions are not clear. To elucidate the roles of these interactions, we introduced amino acid substitutions in VP1 at cysteine residues and at residues involved in calcium binding. We expressed the mutant proteins in a baculovirus system and analyzed both their assembly into virus-like particles (VLPs) in insect cells and the disassembly of those VLPs in vitro. We found that disulfide linkages at both Cys-9 and Cys-104 conferred resistance to proteinase K digestion on VLPs, although neither linkage was essential for the formation of VLPs in insect cells. In particular, reduction of the disulfide linkage at Cys-9 was found to be critical for VLP dissociation to VP1 pentamers in the absence of calcium ions, indicating that disulfide linkage at Cys-9 prevents VLP dissociation, probably by increasing the stability of calcium ion binding. We found that amino acid substitutions at carboxy-terminal calcium ion binding sites (Glu-329, Glu-330, and Asp-345) resulted in the frequent formation of unusual tubular particles as well as VLPs in insect cells, indicating that these residues affect the accuracy of capsid assembly. In addition, unexpectedly, amino acid substitutions at any of the calcium ion binding sites tested, especially at Glu-157, resulted in increased stability of VLPs in the absence of calcium ions in vitro. These results suggest that appropriate affinities of calcium ion binding are responsible for both assembly and disassembly of the capsid.

Animals↗
PubMed2001

Sequences in the NS5A protein of hepatitis C virus and the serum alanine aminotransferase response to interferon therapy in Japanese patients.

BACKGROUND AND AIMS: Chronic hepatitis C is a slowly progressive disease and eventually causes hepatocellular carcinoma in many patients. Although interferon (IFN) therapy has been used for viral eradication, its success rate is only about 30%. In patients in whom it has failed (non-responders), there are several patterns of serum alanine aminotransferase (ALT) values, and detection of serum HCV-RNA during and after IFN therapy and improved long term prognosis were reported in patients whose serum ALT values were normalised by IFN therapy even if HCV viraemia persisted. The present study sought to clarify the virological characteristics contributing to these differences. METHODS: Complete or partial length dominant sequences of hepatitis C virus genotype 1b (HCV-1b) were determined by direct sequencing. Firstly, the complete sequences of HCV-1b genomes were determined in six non-responders; three showed normalisation of serum ALT values during IFN-alpha therapy and the other three did not. Subsequently, the amino acid residues that were different in the two groups were further analysed retrospectively in another 82 patients. RESULTS: Comparison of the sequences suggested an association between amino acids 2154-2172 of HCV-1b and serum ALT normalisation. A retrospective analysis of 82 patients revealed that the number of amino acid substitutions in this region was the only statistically significant variable associated with ALT normalisation (odds ratio 31.0; 95% confidence interval 5.0-286) in multivariate analyses. CONCLUSIONS: A HCV genomic region that correlates with the ALT response to IFN therapy appears to be present in virologically IFN ineffective patients.

Adult↗
PubMed2001

Prediction of contractile reserve by cyclic variation of integrated backscatter of the myocardium in patients with chronic left ventricular dysfunction.

OBJECTIVE: To clarify whether assessment of the acoustic properties of the myocardium at rest can predict contractile reserve in patients with chronic left ventricular dysfunction. METHODS: 23 patients (mean (SD) age 63 (12) years) with chronic left ventricular dysfunction were studied. The magnitude of cardiac cycle dependent variation of integrated backscatter (CVIB) of the myocardium was measured at rest in the basal and mid segment of the septum and posterior wall of the left ventricle, using a real time two dimensional integrated backscatter imaging system. The results were compared with the percentage wall thickening and the wall motion at rest and during low dose dobutamine infusion. The wall motion was graded as normal, hypokinetic, or akinetic and contractile reserve was considered present when an akinetic or hypokinetic segment improved during dobutamine infusion. RESULTS: The CVIB at rest correlated with per cent wall thickening at rest and during dobutamine infusion (at rest, r = 0.61, p < 0.0001, during dobutamine, r = 0.76, p < 0.0001). Of the 76 segments examined, 27 showed contractile reserve. The mean CVIB at rest was significantly greater in segments with contractile reserve than in those without (p < 0.0001). CVIB above 3 dB at rest predicted segments with contractile reserve with a sensitivity and specificity of 81% and 60%, respectively (p < 0.0001). CONCLUSIONS: CVIB reflected not only myocardial contractility but also the functional capacity of the myocardium. It predicted segmental contractile reserve in patients with chronic left ventricular dysfunction.

Adult↗
PubMed2001

Cardiac (123)I-meta-iodobenzylguanidine (MIBG) uptake in dementia with Lewy bodies: comparison with Alzheimer's disease.

Cardiac (123)I-meta-iodobenzylguanidine (MIBG) uptake was measured in 11 patients with dementia with Lewy bodies (DLB), 10 patients with Alzheimer's disease (AD), and 10 age matched control subjects. The severity of cognitive impairment and duration of symptoms in patients with DLB matched that in the patients with AD. The heart/mediastinum (H/M) ratio of MIBG uptake in the patients with AD was indistinguishable from that in the control subjects. However, the H/M ratio in all patients with DLB was significantly lower than that in the patients with AD and control subjects (p<0.001). These findings indicate that local myocardial sympathetic nerves are affected in DLB and that cardiac (123)I-MIBG scintigraphy may provide a means of differentiating DLB from AD.

3-Iodobenzylguanidine↗
PubMed2001

Peripheral lung adenocarcinoma: correlation of thin-section CT findings with histologic prognostic factors and survival.

PURPOSE: To evaluate the prognostic importance of thin-section computed tomographic (CT) findings of peripheral lung adenocarcinomas. MATERIALS AND METHODS: The subjects were 127 patients with adenocarcinomas smaller than 3 cm in largest diameter who underwent at least a lobectomy with hilar and mediastinal lymphadenectomy. The margin characteristics of nodules and the extent of ground-glass opacity (GGO) within the nodules at preoperative thin-section CT were analyzed retrospectively. Regional lymph node metastasis (LNM) and vessel invasion (VI) were histologically examined in surgical specimens. Survival curves were calculated according to the Kaplan-Meier method. RESULTS: The frequencies of LNM (4% [1 of 24]) and VI (13% [three of 24]) in adenocarcinomas with GGO components of more than 50% were significantly lower than those with GGO components of less than 10% (LNM, P <.05; VI, P <.01). The patients with GGO components of more than 50% showed a significantly better prognosis than those with GGO components less than 50% (P <.05). All 17 adenocarcinomas smaller than 2 cm with GGO components of more than 50% were free of LNM and VI, and all these patients are alive without recurrence. Coarse spiculation and thickening of bronchovascular bundles around the tumors were observed more frequently in tumors with LNM or VI than in those without LNM or VI (P <.01). CONCLUSION: Thin-section CT findings of peripheral lung adenocarcinomas correlate well with histologic prognostic factors.

Adenocarcinoma↗
PubMed2001

FDG PET of primary benign and malignant bone tumors: standardized uptake value in 52 lesions.

PURPOSE: To evaluate the standardized uptake value (SUV) of 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) at positron emission tomography (PET) in the differentiation of benign from malignant bone lesions. MATERIALS AND METHODS: Fifty-two (19 malignant, 33 benign) primary bone lesions were examined with FDG PET prior to tissue diagnosis. The SUVs were calculated and compared between benign and malignant lesions and among histologic subgroups that included more than four cases. RESULTS: There was a statistically significant difference in SUV between benign (2.18 +/- 1.52 [SD]) and malignant (4.34 +/- 3.19) lesions in total (P =.002). However, giant cell tumors (n = 5; SUV, 4.64 +/- 1.05) showed significantly higher SUV than chondrosarcomas (n = 7; SUV, 2.23 +/- 0.74) (P =.036, adjusted for multiple comparisons) and had no statistically significant difference in SUV compared with osteosarcomas (n = 6; SUV, 3.07 +/- 0.96) (P =.171). There was no statistically significant difference in SUV between fibrous dysplasias (n = 6; SUV, 2.05 +/- 0.98) and osteosarcoma (P =.127) or chondrosarcomas (P =.667). Although the number of cases was small, three chondroblastomas, one sarcoidosis, and one Langerhans cell histiocytosis showed levels of FDG accumulation as high as that of osteosarcomas. CONCLUSION: Radiologists should be aware of the high accumulation of FDG in some benign bone lesions, especially histiocytic or giant cell-containing lesions. Consideration of histologic subtypes should be included in analysis of SUV at FDG PET of primary bone tumors.

Adult↗
PubMed2001

Role of endothelial Ni(2+)-sensitive Ca(2+) entry pathway in regulation of EDHF in porcine coronary artery.

Elevation of intracellular Ca(2+) concentration ([Ca(2+)](i)) in endothelial cells is proposed to be required for generation of vascular actions of endothelium-derived hyperpolarizing factor (EDHF). This study was designed to determine the endothelial Ca(2+) source that is important in development of EDHF-mediated vascular actions. In porcine coronary artery precontracted with U-46619, bradykinin (BK) and cyclopiazonic acid (CPA) caused endothelium-dependent relaxations in the presence of N(G)-nitro-L-arginine (L-NNA). The L-NNA-resistant relaxant responses were inhibited by high K(+), indicating an involvement of EDHF. In the presence of Ni(2+), which inhibits Ca(2+) influx through nonselective cation channels, the BK-induced EDHF relaxant response was greatly diminished and the CPA-induced response was abolished. BK and CPA elicited membrane hyperpolarization of smooth muscle cells of porcine coronary artery. Ni(2+) suppressed the hyperpolarizing responses in a manner analogous to removal of extracellular Ca(2+). EDHF-mediated relaxations and hyperpolarizations evoked by BK and CPA in porcine coronary artery showed a temporal correlation with the increases in [Ca(2+)](i) in porcine aortic endothelial cells. The extracellular Ca(2+)-dependent rises in [Ca(2+)](i) in endothelial cells stimulated with BK and CPA were completely blocked by Ni(2+). These results suggest that Ca(2+) influx into endothelial cells through nonselective cation channels plays a crucial role in the regulation of EDHF.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed2001

Fat-soluble vitamin status is not affected by diacylglycerol consumption.

OBJECTIVE: The objective of this study was to examine the effect of dietary diacylglycerol (DAG) on the bioavailability of fat-soluble vitamins in comparison with triacylglycerol (TAG). METHODS: We conducted a long-term administration test of DAG and TAG in 27 healthy men aged 27-47 years. After measuring baseline values, subjects were randomized into two groups, one group (n = 15) was given DAG and the other (n = 12) was given TAG. Subjects ingested 20 g of DAG or TAG either in mayonnaise or an emulsion drink of their own choice at meals once a day for 12 weeks. At 4, 8 and 12 weeks, fasting blood samples were drawn and serum levels of vitamin A, E, and D were measured. RESULTS: There were no significant changes in vitamin A levels throughout the study period. Compared to the initial values (using a Student's t test for paired values), significant differences of vitamin E and D were seen at some points during the experiment. According to a two-way repeated measures analysis of variance, however, DAG and TAG (lipid) and time had no effect on fat-soluble vitamin levels. CONCLUSIONS: Our results indicate that DAG does not affect the absorption of the fat-soluble vitamins in diets.

Adult↗
PubMed2001

Pancreatitis-associated protein levels in pancreatic juice from patients with pancreatic diseases.

BACKGROUND: Pancreatitis-associated protein (PAP), the acute-phase protein of the pancreas, is overexpressed in acute pancreatitis. Serum PAP levels were reported to be useful as an indicator of the severity, prognosis and healing of acute pancreatitis. Although PAP was originally identified in pancreatic juice, there has been no clinical report on PAP levels in pancreatic juice. This study was conducted to determine levels of PAP in pancreatic juice (PJ-PAP) in various human pancreatic diseases. METHODS: PAP levels in endoscopically aspirated PJ were measured by enzyme-linked immunosorbent assay in 86 patients with pancreatic diseases. RESULTS: 55% of 22 patients with pancreatic cancer (PC) and 25% of 49 patients with chronic pancreatitis (CP) were positive (> 350 ng/ml) for PJ-PAP. PJ-PAP levels were significantly higher in PC than in CP, in which PJ-PAP was also significantly higher than in 15 control subjects. There was no significant correlation between PJ-PAP and serum PAP, and combination assay of serum PAP and/or PJ-PAP detected 80% of PC cases and 44% of CP cases. CONCLUSIONS: We have demonstrated that human PAP could be detected in pancreatic juice from patients with pancreatic diseases. Determination of PAP in pancreatic juice might be helpful for early detection of pancreatic injury.

Acute-Phase Proteins↗
PubMed2001

Myosin light chain kinase regulates capacitative ca(2+) entry in human monocytes/macrophages.

Monocytes/macrophages are present in all stages of atherosclerosis. Although many of their activities depend to various extents on changes in intracellular Ca(2+) concentration ([Ca(2+)](i)), mechanisms regulating [Ca(2+)](i) in these cells remain unclear. We aimed to explore the role of myosin light chain kinase (MLCK) in Ca(2+) signaling in freshly isolated human monocytes/macrophages. Large capacitative Ca(2+) entry (CCE) was observed under fura 2 fluoroscopy in human monocytes/macrophages treated with thapsigargin and cyclopiazonic acid. ML-9 and wortmannin, 2 structurally different inhibitors of MLCK, dose-dependently (1 to 100 micromol/L) prevented CCE and completely did so at 100 micromol/L, whereas inhibitors of tyrosine kinase and protein kinase C had only partial effects. Western blotting showed that thapsigargin significantly caused myosin light chain phosphorylation, which was almost completely blocked by ML-9 (100 micromol/L) and wortmannin (100 micromol/L). ML-9 also dose-dependently (1 to 100 micromol/L) inhibited this phosphorylation, which was well correlated with its inhibition of CCE. Transfection with MLCK antisense completely prevented CCE in response to thapsigargin and cyclopiazonic acid, whereas MLCK sense had no effect. These data strongly indicate that MLCK regulates CCE in human monocytes/macrophages. The study suggests a possible involvement of MLCK in many Ca(2+)-dependent activities of monocytes/macrophages.

Androstadienes↗
PubMed2001

Myopathic form of very-long chain acyl-coa dehydrogenase deficiency: evidence for temperature-sensitive mild mutations in both mutant alleles in a Japanese girl.

In a 14-year-old Japanese girl, manifested recurrent myalgia with elevated serum creatine kinase after moderate exercise became evident, and she was diagnosed as having a myopathic form of very-long chain acyl-CoA dehydrogenase deficiency. Her first clinical symptom of the disease was evident when she was 6 y of age. She had never had hypoglycemic attacks, and hepatomegaly and cardiomyopathy were absent. The diagnosis was suspected on the basis of the urinary organic acid profile after a 36-h fast, long-chain fatty acid-loading test, and the blood acylcarnitine profile. Acyl-CoA dehydrogenase activity with palmitoyl-CoA as a substrate was severely decreased in her fibroblasts, and the amount of very-long chain acyl-CoA dehydrogenase protein was reduced. She was a compound heterozygote of A416T from her father and R450H from her mother. Transient expression of mutant A416T cDNA retained a significant residual acyl-CoA dehydrogenase activity of 10% and 20% normal at 37 degrees C and 30 degrees C, respectively. Specific activity of A416T mutant protein was calculated to be one fifth that of control. In the case of R450H mutant expression, a low residual acyl-CoA dehydrogenase activity of 5% normal was detected at 30 degrees C although significant activity was absent at 37 degrees C. The R450H protein was not detected at 37 degrees C but was clearly detected at one fourth the normal amount at 30 degrees C. These results indicate that both mutations were temperature-sensitive mild mutations, the result being the mildest phenotype of very-long chain acyl-CoA dehydrogenase deficiency.

Acyl-CoA Dehydrogenase, Long-Chain↗
PubMed2001

Ameliorative effects of paeoniflorin, a major constituent of peony root, on adenosine A1 receptor-mediated impairment of passive avoidance performance and long-term potentiation in the hippocampus.

We examined the effects of paeoniflorin on adenosine A1 receptor-mediated memory disturbance in the mouse passive avoidance test and inhibition of long-term potentiation (LTP) in the rat hippocampal CA1 region. The pretraining administration of the selective adenosine A1 receptor agonist N6-cyclopentyladenosine (CPA) significantly impaired the retention performance determined 24 h after the training test. The intraperitoneal injections of paeoniflorin and the adenosine A1 receptor antagonist 1,3-dipropyl-8-cyclopentylxanthine (DPCPX) significantly attenuated the deficit in retention performance caused by CPA. The in vitro studies revealed that adenosine (1 and 10 microM) dose dependently reduced both the population spike (PS) amplitudes and the tetanic stimulation-induced LTP in the hippocampus. DPCPX, at the concentration (0.1 microM) that had no effect on PS amplitudes or LTP induction, significantly reversed the suppressive effects of adenosine on both indices. Paeoniflorin also dose dependently reversed 10 microM adenosine-induced suppression of LTP but had no effect on PS reduced by adenosine. These results suggest that paeoniflorin ameliorates memory disruption mediated by adenosine A1 receptor and that modulation of adenosine-mediated inhibition of LTP in the hippocampus is implicated in its beneficial effect on learning and memory impairment in rodents.

Adenosine↗