Biomedical subjects

Y Yamazaki

Publications and source records attributed to Y Yamazaki.

At least 37 records · Page 2Linked to original sources

PubMed2005

Association of low-density lipoprotein particle size distribution and cardiovascular risk factors in children.

AIM: The objective of this study was to investigate whether the presence of small, dense lipoproteins, which are thought to be related to the metabolic syndrome caused by insulin resistance, can be predicted by routine serum lipid profiling. METHODS: The relationship between low-density lipoprotein (LDL) particle size and serum lipid levels was analysed in 284 school children (148 boys and 136 girls), aged 7 to 13 y old. LDL particle size was determined by gradient gel electrophoresis. RESULTS: The LDL particle diameter was significantly correlated with the serum levels of high-density lipoprotein cholesterol (HDL-C) (r = - 0.437, p < 0.001) and triglycerides (TG) (r = -0.432, p < 0.001), and with the atherogenic index (AI) [total cholesterol/ HDL-C] (r = -0.450, p < 0.001), while only weak correlations were observed with the serum levels of total cholesterol, apolipoprotein Al and apolipoprotein B. No significant relationship was observed between LDL particle diameter and the serum LDL-C level. CONCLUSION: The presence of small, dense LDL as a metabolic marker of lifestyle-related diseases in children seems to be reflected by a serum lipid profile characterized by an elevation in TG, a reduction in HDL-C, and a raised AI.

Adolescent↗

PubMed2005

Efficacy and outcomes of clarithromycin treatment for pulmonary MAC disease.

SETTING: Retrospective review of patients with pulmonary Mycobacterium avium complex (MAC) disease treated with clarithromycin. OBJECTIVES: To investigate whether the short-term response to treatment predicts long-term outcomes, and to analyse what explanatory variables are associated with the efficacy and outcome of treatment. DESIGN: Sputum conversion rates in short- and long-term outcomes were evaluated for 111 patients. Respectively 9 and 10 explanatory variables were analysed for their association with both response and outcomes. RESULTS: Eighty-four patients (75.7%) showed good short-term response and 94 (82.0%) showed good long-term outcomes. Women and patients with satisfactory nutrition status showed good short-term response. Patients with small lesions and those treated for >12 months after sputum conversion showed good long-term outcomes. Patients who showed good short-term response, in the group with large lesions, showed significantly good long-term outcomes (P = 0.0382). CONCLUSION: There were differences between prognostic factors reflecting short-term response and long-term outcomes. The short-term response predicts long-term outcomes in certain groups divided by prognostic factor. To establish standard treatment for pulmonary MAC disease, it is important to determine a standardised method of evaluation of treatment taking such factors into consideration.

Adult↗

PubMed2004

New scheme for positron accumulation in ultrahigh vacuum.

A new positron accumulation scheme compatible with ultrahigh vacuum conditions has been developed, which is realized by preparing a high density electron plasma as high as approximately 10(11) cm(-3) and an ion cloud as energy absorbers. The present accumulation rate normalized by the intensity of 22Na positron source is (3.6+/-0.3)x10(2)e(+)/s/mCi, which is more than one and a half orders of magnitude higher than other ultrahigh vacuum compatible schemes so far reported.

Journal Article↗

PubMed2004

Radial compression of protons and H3+ ions in a multiring trap for the production of ultralow energy antiproton beams.

Radial compression of a proton cloud was performed in a multiring trap which was designed to trap and cool a large number of antiprotons for the production of low-energy ( 10-1000 eV ) antiproton beams. The resonance frequency for the radial compression was almost constant from 3 x 10(5) to 3 x 10(6) protons. The collision process of the trapped protons was also investigated to estimate the energy of the protons inside the trap. This technique will be applied to the ASACUSA experiment at the antiproton decelerator, CERN, to extract ultraslow antiprotons with good emittance.

Journal Article↗

PubMed2004

Three-dimensional annihilation imaging of trapped antiprotons.

We demonstrate three-dimensional imaging of antiprotons in a Penning trap, by reconstructing annihilation vertices from the trajectories of the charged annihilation products. The unique capability of antiparticle imaging has allowed, for the first time, the observation of the spatial distribution of the particle loss in a Penning trap. The radial loss of antiprotons on the trap wall is localized to small spots, strongly breaking the azimuthal symmetry expected for an ideal trap. Our observations have important implications for detection of antihydrogen annihilations.

Journal Article↗

PubMed2004

Infrared ray electronic endoscopy combined with indocyanine green injection for detection of sentinel nodes of patients with gastric cancer.

BACKGROUND: To avoid unnecessary lymphadenectomy in patients with cancer accurate diagnosis of the sentinel lymph node (SLN) is important. METHODS: This report examined the initial clinical use of infrared ray electronic endoscopy (IREE) combined with indocyanine green (ICG) injection for SLN detection in 84 patients with gastric cancer not invading the subserosa (75 T1 N0 M0 and nine T2 N0 M0 tumours, according to tumour node metastasis classification). RESULTS: There were no adverse events after injection of ICG. At least one SLN was detected in all but one patient by both ICG injection alone and by IREE with ICG. Eleven of the 84 patients had lymph node metastasis. SLNs detected by ICG injection alone did not include metastases in four of 11 patients, whereas IREE with ICG detected SLNs containing lymph node metastases in all 11 patients. Moreover, SLNs illuminated by IREE with ICG included all metastases among the 105 regional lymph nodes in the 11 patients; no metastatic lymph nodes were identified among 154 non-SLNs. CONCLUSION: IREE combined with ICG injection may efficiently detect SLNs that contain metastases in patients with gastric cancer.

Coloring Agents↗

PubMed2004

Sexual activities and social relationships of people with HIV in Japan.

Sixty-one Japanese with sexually transmitted HIV were investigated to clarify the state of, and difficulties in, their sexual activities and social relationships. The study revealed the following difficulties in social relationships due to HIV infection. Thirty-one per cent had experienced discrimination or breach of confidentiality. Self-restriction due to anxiety over discrimination was observed in approximately 90%, and the self-restriction score tended to be higher in those who were not employed, those with economic problems, those who were in a relatively poor state of health, those who had developed AIDS and those who had previously experienced discrimination or breach of confidentiality. The experience of discrimination or breach of confidentiality, and the experience of receiving negative support tended to increase as the respondents had a wider emotional support network. About 60% were dissatisfied with their sex lives, and the degree of satisfaction was significantly lower in those who had fewer sexual contacts and those who had a suppressive attitude toward sexual contacts. A low degree of satisfaction with sex life was found to be an important factor that escalates the level of depression or anxiety.

Adaptation, Psychological↗

PubMed2004

Evaluation of treatment for gastro-oesophageal reflux disease with a proton pump inhibitor, and relationship between gastro-oesophageal reflux disease and Helicobacter pylori infection in Japan.

BACKGROUND: Effective therapy for gastro-oesophageal reflux disease (GERD) is associated with improvement in health-related quality of life. It remains unclear whether Helicobacter pylori infection protects against GERD. AIM: We evaluated the relationship between GERD and H. pylori, and whether the health-related quality of life score improved after medical treatment. METHODS: We enrolled 151 outpatients with upper abdominal symptoms; 81 patients received omeprazole 20 mg/day for 2 weeks. Health-related quality of life was assessed using the Gastrointestinal Symptom Rating Scale (GSRS) and the Psychological General Well-Being (PGWB) index. H. pylori infection was diagnosed by serum antibody or endoscopy and the relationship between GERD and H. pylori was evaluated. RESULTS: In GERD patients, the mean GSRS score improved from 2.20 to 1.67 following treatment (P < 0.01). The mean GSRS reflux symptom score improved from 2.96 to 1.67 (P < 0.01). The mean PGWB score improved from 96.36 to 107.34 (P < 0.01). All scores in GERD patients significantly improved compared with non-GERD patients. The H. pylori-positive ratio was 66.15% in GERD patients and 65.21% in non-GERD patients (P = 0.94). CONCLUSIONS: Health-related quality of life is useful for evaluation of proton pump inhibitor treatment in GERD. The presence of H. pylori was not associated with the prevalence of GERD.

Anti-Ulcer Agents↗

PubMed2004

Urothelium regeneration using viable cultured urothelial cell sheets grafted on demucosalized gastric flaps.

OBJECTIVE: To evaluate urothelium regeneration by grafting viable cultured urothelial cell sheets, harvested from temperature-responsive culture surfaces, on demucosalized gastric flaps in a dog model. MATERIALS AND METHODS: Viable urothelium was obtained from eight beagle dogs by partial cystectomy. Harvested urothelial cells were seeded on temperature-responsive culture dishes modified with the thermally sensitive polymer, poly(N-isopropylacrylamide). Urothelial cells cultured for 3 weeks generated contiguous urothelial cell sheets that were noninvasively harvested with no enzymatic treatment from these dishes, by reducing culture temperature. Urothelial cell sheets were autografted onto surgically demucosalized gastric flaps. Three weeks after autografting the dogs were killed and the gastric flaps with the urothelial cell sheets were examined. Cell and tissue characteristics were compared between these urothelial cell sheet-grafted gastric flaps and native urothelium. Ultrafine structures were also examined by electron microscopy. RESULTS: Five of the eight urothelial cell sheet-grafted flaps showed viable urothelial regeneration. Urothelial cell sheets attached spontaneously to demucosalized tissue surfaces completely, with no suture or fixing, and developed into a stratified viable epithelium very similar to native urothelium. Regenerated urothelium remained unstained by antiproton pump antibody, which typically stains epithelial cells positively in gastric mucosal layers. On three of the eight flaps where there were severe haematomas, grafted cell sheets were not adherent and there was no urothelial regeneration. CONCLUSIONS: Urothelial cell sheets were autografted onto dog demucosalized gastric flaps successfully, with no suture or fixation, generating a multilayered urothelium in vivo. The novel intact cell-sheet grafting method rapidly produces native-like epithelium in vivo. This versatile technology should prove useful in urinary tract tissue engineering and surgical reconstruction.

Animals↗

PubMed2004

Molecular epidemiology of tuberculosis in the north Hokkaido district of Japan.

SETTING: The incidence of tuberculosis in Japan has fallen rapidly in the past 50 years, to 27.9 cases per 100,000 population in 2001. OBJECTIVE: To assess the molecular epidemiology of tuberculosis in the north Hokkaido district, Japan. DESIGN: Restriction fragment length polymorphism analysis was consecutively performed on Mycobacterium tuberculosis strains from patients with pulmonary tuberculosis from April 1999 to March 2002. RESULTS: Of 229 patients, strains from 227 (99.1%) were available for analysis. The mean age of the patients analysed was 69.4 years. There was one immigrant patient. Two hundred and seven patients had six or more copies of IS6110. Of these, 16 (7.7%) in eight clusters had identical patterns, 120 (58.0%) belonged to five groups that had similar patterns (Dice coefficient >0.7) and 80 (38.6%) belonged to the 35 groups with the most common patterns (Dice coefficient >0.9). CONCLUSION: These results may reflect the epidemiological characteristics, age and migration of the residents and the incidence of tuberculosis of the area, and also those of Japan: many elderly patients were infected in the past, when the incidence of tuberculosis was very high.

Adolescent↗

PubMed2003

Discrimination of homoeologous gene expression in hexaploid wheat by SNP analysis of contigs grouped from a large number of expressed sequence tags.

Single-nucleotide polymorphisms (SNPs) are useful markers for gene diagnosis and mapping of genes on chromosomes. However, polyploidy, which is characteristic of the evolution of higher plants, complicates the analysis of SNPs in the duplicated genes. We have developed a new method for SNP analysis in hexaploid wheat. First, we classified a large number of expressed sequence tags (ESTs) from wheat in silico. Those grouped into contigs were anticipated to correspond to transcripts from homoeologous loci. We then selected relatively abundant ESTs, and assigned these contigs to each of the homoeologous chromosomes using a nullisomic/tetrasomic series of Chinese Spring wheat strains in combination with pyrosequencing. The ninety genes assigned were almost evenly distributed into seven homologous chromosomes. We then created a virtual display of the relative expression of these genes. Expression patterns of genes from the three genomes in hexaploid wheat were classified into two major groups: (1) genes almost equally expressed from all three genomes; and (2) genes expressed with a significant preference, which changed from tissue to tissue, from certain genomes. In 11 cases, one of the three genes in the allopolyploid was found to be silenced. No preference for gene-silencing in particular genomes or chromosomes was observed, suggesting that gene-silencing occurred after polyploidization, and at the gene level, not at the chromosome or genome level. Thus, the use of this SNP method to distinguish the expression profiles of three homoeologous genes may help to elucidate the molecular basis of heterosis in polyploid plants.

Base Sequence↗

PubMed2003

Asymmetric transport due to spin injection into a Kondo alloy.

Spin injection is found to have a significant effect on the transport properties of the Kondo alloy Cu(Fe). When a spin-polarized electron current flows from Co into Cu(Fe) wires through the Co/Cu(Fe) interface, the resistivity of the Cu(Fe) wire is suppressed near the interface, as distinct from the ordinary logarithmic increase in the resistivity at low temperatures. For the opposite current direction, no significant changes are observed. The asymmetry of the resistivity with respect to the current direction decays with a characteristic length of 1.5+/-0.4 microm at 2.5 K as the distance from the interface is increased. Possible mechanisms for the asymmetry are discussed.

Journal Article↗

PubMed2003

Sast124, a novel splice variant of syntrophin-associated serine/threonine kinase (SAST), is specifically localized in the restricted brain regions.

Syntrophin is an adaptor protein that binds signaling molecules to the dystrophin-associated protein complex, which connects extracellular matrix to intracellular cytoskeleton for construction and maintenance of the postsynaptic structures in the neuromuscular junction and the CNS. Among these signaling molecules, a family of microtubule-associated serine/threonine kinases has a unique structural feature with a serine/threonine kinase domain and a postsynaptic density protein-95/discs large/zona occludens-1 domain. In the present study, we identified syntrophin-associated serine/threonine kinase-124, a novel splice variant of the syntrophin-associated serine/threonine kinase which is a member of the microtubule-associated serine/threonine kinases family. Comparing to the original clone (syntrophin-associated serine/threonine kinase-170), syntrophin-associated serine/threonine kinase-124 is truncated just downstream of the postsynaptic density protein-95/discs large/zona occludens-1 domain. Using a monoclonal antibody specifically recognizing syntrophin-associated serine/threonine kinase-124, strong expression of the protein was observed in neurons of the subventricular zone and granule cells of the olfactory bulb, Islands of Calleja, hippocampal dentate gyrus and cerebellum. syntrophin-associated serine/threonine kinase-124 is selectively localized in the nuclei of neurons and distinct from syntrophin-associated serine/threonine kinase-170, which is interacting with syntrophin on the cell surface. Considering the tissue and subcellular distributions of syntrophin-associated serine/threonine kinase-124, it is suggested that syntrophin-associated serine/threonine kinase-124 may have functions in transcriptional regulation for the features commonly shared by these neurons. On the other hand, syntrophin-associated serine/threonine kinase-124 was also localized in glia-like cell bodies in the corpus callosum and fiber bundles in the spinal trigeminal and solitary tracts, suggesting syntrophin-associated serine/threonine kinase-124 may have other functions in these types of cells.

Amino Acid Sequence↗

PubMed2003

Association of the HLA-DRB1 gene locus with gastric adenocarcinoma in Japan.

BACKGROUND AND AIM: Helicobacter pylori infection is associated with gastric adenocarcinoma, however, the odds ratio is relatively low. The aim of the present study was to investigate host genetic factors that increase the risk of gastric adenocarcinoma among H. pylori-infected individuals. METHODS: A total of 70 patients with early gastric adenocarcinoma and 121 unrelated healthy controls were examined for H. pylori infection and HLA-DRB1 genotyping. The frequencies of HLA-DRB1 alleles were compared among groups. RESULTS: The allele frequency of DRB1*04051 was significantly higher in patients with gastric adenocarcinoma (17.9%) than in controls (7.9%) (P(correct) = 0.045). The odds ratio of gastric adenocarcinoma associated with the presence of the HLA-DRB1*04051 allele compared with its absence was 2.55 (95% confidence limits, 1.35-4.83). This genetic risk was not associated with H. pylori infection. There was no significant difference in the HLA-DRB1 allele frequency between H. pylori-positive and H. pylori-negative controls. The frequency of genotypes that possessed the DRB1*04051 allele in gastric adenocarcinoma patients (34.3%) was significantly higher than that in H. pylori-negative controls (11.9%) (p = 0.0089) and H. pylori-positive controls (15.2%) (p = 0.0066). CONCLUSION: These findings suggest that immunogenetic factors for susceptibility to gastric adenocarcinoma are present in the host, the HLA-DRB1*04051 allele is a host genetic risk factor for gastric adenocarcinoma, and that this genetic risk is independent of H. pylori infection.

Adenocarcinoma↗

PubMed2003

The effects of cure of Helicobacter pylori infection on the signal transduction of gastric epithelial cells.

BACKGROUND: The CagA protein of Helicobacter pylori is directly injected from the bacteria into cells via the bacterial type IV secretion system and undergoes tyrosine phosphorylation in the gastric epithelial cells. Translocated CagA forms a physical complex with the SRC homology 2 domain (SH2)-containing tyrosine phosphatase SHP-2, which plays an important role in mitogenic signal transduction in the host cells. AIM: We examined the effect of eradication therapy on the signal transduction pathway of gastric epithelial cells induced by the CagA protein of H. pylori. METHODS: Gastric biopsy samples were obtained from 20 H. pylori-positive atrophic gastritis patients before, and 3 months after, H. pylori infection eradication therapy, and subjected to immunoblot analysis to detect tyrosine phosphorylated CagA protein and CagA co-immunoprecipitated endogenous SHP-2. RESULTS: Tyrosine phosphorylated CagA protein and CagA co-immunoprecipitated endogenous SHP-2 were detected in the gastric mucosa from H. pylori-positive atrophic gastritis patients. All H. pylori strains from these patients were cagA-positive type I strains. After curing H. pylori infection, the tyrosine phosphorylated CagA protein and CagA co-immunoprecipitated endogenous SHP-2 disappeared from the gastric mucosa. CONCLUSION: The cure of infection reduces the stimulated signal transduction of gastric epithelial cells by the translocated CagA protein of H. pylori, and may confer a beneficial effect on the reduction of cancer risk.

Bacterial Proteins↗

PubMed2003

Proliferation of type II pneumocytes in the lung biopsy specimens reflecting alveolar damage.

Proliferation of type II pneumocytes may be the most sensitive pathological indicator of alveolitis, and the density of type II pneumocytes reflecting the severity of the recent alveolar damage. Twenty-nine patients were divided into three groups by the severity of ground-glass opacities on the CT scans; the severe (acute), the moderate (subacute) and the mild (chronic) groups. We compared the density of type II pneumocytes in the transbronchial lung biopsy specimens and cell analysis of bronchoalveolar lavage (BAL) fluid with the ground-glass opacities. Clinical and laboratory findings and BAL fluid analysis also corresponded well with this grouping. Type II pneumocytes were selectively stained with an antibody against Thomsen-Friedenreich and the density of the type II pneumocytes was expressed as the number per 1 mm alveolar septal length. The densities of the type II pneumocytes in the severe, the moderate, the mild, and the control groups were 21.2+/-1.1, 14.4+/-7.2, 11.0+/-3.3 and 7.5+/-0.9/mm, respectively. There were significant differences between the acute group and the other three groups, and between the control and chronic groups. The density of type II pneumocytes is a useful index for evaluating alveolar damage even in mild alveolitis.

Biopsy↗

PubMed2003

Increased vascular endothelial growth factor in acute eosinophilic pneumonia.

Acute eosinophilic pneumonia (AEP) is associated with the presence of diffuse pulmonary infiltrates on the chest radiograph and an increased number of eosinophils and an elevation of interleukin (IL)-5 levels in bronchoalveolar lavage (BAL) fluid. Vascular endothelial growth factor (VEGF) is a constitutively expressed protein encoded by messenger ribonucleic acid in human eosinophils and is released following stimulation with IL-5. However, the roles of IL-5 and VEGF in the pathogenesis or activity of this disease have not been clarified. The authors investigated the cells and the levels of these two factors in BAL fluid in five AEP patients and five normal controls before and after corticosteroid treatment. The absolute number of eosinophils-mL(-1), IL-5 and VEGF levels in patients before treatment were higher than in controls (53.8 versus 0.3 x 10(4) x mL(-1), 490.1 versus 5.2 pg x mL(-1) and 643.0 versus 133.9 pg x mL(-1), respectively). IL-5 and VEGF rapidly decreased to the control level in parallel with clinical improvement. The relationship between eosinophilia and IL-5 and VEGF levels was strongly significant. Elevated interleukin-5 in the lung may initiate the recruitment of eosinophils and enhance the release of mediators, such as vascular endothelial growth factor from eosinophils, which, in turn, increases the permeability of blood vessels.

Acute Disease↗

PubMed2003

Disseminated Mycobacterium avium complex (DMAC) in an immunocompetent adult.

A female patient with multiple osteomyelitis and pulmonary Mycobacterium avium disease visited an orthopaedic clinic with back pain. Systemic bone scan showed multiple sites of increased radioactivity in the vertebral bodies, right scapula, femurs and ribs. M. avium was isolated from sputum and a sample aspirated from the right scapula. The route of infection was unknown as there was no history of trauma or surgery. HIV testing was negative. As there was no underlying immunological disease she was diagnosed as disseminated M. avium complex (DMAC) disease in an immunocompetent adult. Cytokine production on several stimuli from peripheral blood mononuclear cells was similar to that in pulmonary M. avium patients. Sequence analysis of IFN-gamma receptor revealed no nucleotide substitution. We detected serotypes 1, 2 and 4 from mycobacteria cultured from the right scapula, and conclude that this case could be the result of undetected immune deficiency and/or unrecognised virulence of the infecting isolate.

Female↗