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Biomedical subjects

Y Yoshimura

Publications and source records attributed to Y Yoshimura.

At least 37 records · Page 2Linked to original sources
PubMed2003

[Surgical treatment in an infant with atrial septal defect and persistent left superior vena cava draining into the coronary sinus; report of a case].

A 8-month-old boy with ostium secundum atrial septal defect and persistent left superior vena cava draining into the coronary sinus underwent surgical treatment because he had required long-term ventilator support due to congestive heart failure and respiratory distress. The left superior vena cava and dilated coronary sinus produce a ridge in the left atrium, causing a subdivided left atrium. In this case, the early symptom could be explained by an obligatory left to right shunt at the level of the left atrium resulting from a ridge produced by the left superior vena cava and the colonary sinus, as a subdivided left atrium.

Cardiac Surgical Procedures↗
PubMed2003

[Right-sided infective endocarditis with a large size vegetation].

A 2-year-old boy with ventricular septal defect(VSD) had suffered from right-sided infective endocarditis with a vegetation 1.0 cm in size, involving pulmonary valve. Resection of the vegetation and partial resection of the pulmonary valve and patch closure of the VSD was performed after 3 weeks intravenous antibiotic therapy. In right-sided infective endocarditis, it is still unclear, however, which factors may be useful in predicting outcome or determining the need of surgical intervention. We recognize that following factors are the risk for need of surgical intervention. 1. persistent infection, 2. sever right-sided heart failure, 3. multiple embolic episodes, 4. infected by Staphylococcus aureus, 5. infection involving the annulus of the valve, 6. infection of prosthetic valve, 7. vegetation which is floppy and greater than 1.0 cm in size.

Child, Preschool↗
PubMed2002

Flow cytometric determination of intracytoplasmic Wiskott-Aldrich syndrome protein in peripheral blood lymphocyte subpopulations.

We have produced a novel monoclonal antibody (mAb) directed against Wiskott-Aldrich syndrome protein (WASP) by immunizing mice with the recombinant protein. The mAb designated 5A5 is highly specific to WASP and suitable for Western blot analysis and immunoprecipitation. A flow cytometric assay using the 5A5 mAb identifies expression of intracytoplasmic WASP in lymphocytes from normal individuals. Double staining analysis with cell surface CD3, CD19, and CD56, and intracytoplasmic molecules revealed WASP expression in each subpopulation. With regard to WASP expression in patients with Wiskott-Aldrich syndrome (WAS) and X-linked thrombocytopenia (XLT), peripheral blood mononuclear cells (PBMCs) from nine patients and Epstein-Barr virus-transformed B-lymphoblastoid cell lines from seven patients examined did not show WASP expression by flow cytometric analysis. These results were confirmed by Western blot analysis. We conclude that WASP expression in lymphocyte subpopulations from patients with WAS and XLT can be more precisely evaluated by flow cytometry as compared with Western blot analysis. This flow cytometry method is important as a supplement to Western blots, but even more important as an alternative and powerful assay that can contribute to research on WASP as well as diagnosis in a clinical setting.

Animals↗
PubMed2002

Island dynamics in the large-helical-device plasmas.

In the Large Helical Device plasma discharges, the size of an externally imposed island with mode number ( n/m = 1/1) decreases substantially when the plasma is collisionless ( nu(*)< approximately 1) and the beta is finite ( > approximately 0.1%) at the island location. For the collisional plasmas with finite beta, on the other hand, the size of the island increases. However, there is a threshold in terms of the vacuum island size below which the island enlargement is not seen.

Journal Article↗
PubMed2002

Further evidence for the decay K+ -->pi+nu(nu).

Additional evidence for the rare kaon decay K+-->pi+nu(nu) has been found in a new data set with comparable sensitivity to the previously reported result. One new event was observed in the pion momentum region examined, 211 pi+nu(nu)) = 1.57(+1.75)(-0.82)x10(-10).

Journal Article↗
PubMed2002

Cell proliferation and apoptosis in the anterior pituitary of chicken during inhibition and resumption of laying.

The goal of this study was to determine whether tissue rejuvenation of the anterior pituitary with cell proliferation and apoptosis occurs during inhibition and resumption of egg-laying. White Leghorn laying hens were subjected to inhibition of laying by feed withdrawal. Feeding was resumed on the fourth day of egg-laying cessation. All birds were injected ip with bromodeoxyuridine (BrdU) 1 h before tissue collection. The anterior pituitary glands were collected from hens of the following groups: pretreatment (PT), 3 and 5 days after starvation (3DS and 5DS, respectively), 3 days after cessation of laying (3DC), 10 days after cessation of laying (10DC, 6 days after resumption of feeding), and the day of and 1 week after resumption of laying (RL and 1WRL, respectively). They were processed for the detection of proliferating cells and apoptotic cells by BrdU immunostaining and terminal deoxynucleotidyl transferase-mediated biotinylated deoxyuridine triphosphate nick-end-labeling (TUNEL). Immunostaining for the anterior pituitary hormones was also conducted. In the cephalic lobe the BrdU-positive cells showed a higher frequency in RL than in PT, 3DC, and 1WRL. BrdU-positive cell frequency in the caudal lobe was greater in RL than in PT. TUNEL-positive cells in both cephalic and caudal lobes were increased markedly in the RL group. Their frequency in the cephalic lobe was greater in RL than in PT, and that in the caudal lobe of RL was higher than in any other group of birds. The areas of FSH-like cells in 10DC and RL were greater than those in PT to 3DC, and those of LH-like cells in RL were greater than those of 3DS to 3DC. PRL-like cells were decreased until 3DC and then gradually increased until 1WRL. GH-, TSH-, and ACTH-like cell areas showed tendencies to increase until 3DC, with decreasing thereafter. The sizes of FSH-like cells in 10DC to 1WRL and LH-like cells in RL were larger than those around cessation of laying. These results suggest that during inhibition and resumption of laying cell proliferation and apoptosis occur in the anterior pituitary tissue, which may cause a rejuvenation of tissue to improve the function of this organ.

Animals↗
PubMed2002

In vitro assay of hydrolysis and chlorohydroxy derivatives of bisphenol A diglycidyl ether for estrogenic activity.

Bisphenol A diglycidyl ether (BADGE) is an epoxy resin monomer. Epoxy-based solution coatings are used in many applications as additives for a variety of plastic coatings in food packaging. It is well known that unreacted BADGE can migrate from epoxy-based packing materials into foods. Not only BADGE but also its derivatives can easily migrate into foods and it is likely that we intake BADGE and its derivatives through food or drink. Recently, endocrine disrupting chemicals (EDCs) have attracted attention because they have been shown to affect reproduction in wildlife. The estrogenic activity of BADGE derivatives has not previously been investigated. Therefore, we investigated the estrogenic activity of the BADGE derivatives, dihydrolysed BADGE (BADGE-4OH) and chlorohydroxy BADGE (BADGE-2Cl), using breast cancer cell (T47D) proliferation assay and estrogen receptor (ER) (alpha) binding assay. These chemicals exhibited T47D cell proliferation at concentrations of 10(-14)-10(-4) M. However, these chemicals did not bind to ER (alpha) in the binding assay.

Benzhydryl Compounds↗
PubMed2002

Solitary fibrous tumours of the lower gingiva: a case report.

Solitary fibrous tumours (SFTs) are rare lesions in the oral cavity. Typically they arise in the pleura. We report a lesion occurring in the lower anterior gingiva. In histochemical examination, the spindle-shaped, neoplastic cells stained strongly for CD34 antigen and vimentin, but did not stain for desmin, smooth-muscle actin, muscle actin and S-100 protein. The expression of CD34 antigen and vimentin were useful for the differential diagnosis.

Adult↗
PubMed2002

Human periodontal ligament cells derived from deciduous teeth induce osteoclastogenesis in vitro.

The receptor activator of NF-kappa B ligand (RANKL) and its decoy receptor, osteoprotegerin (OPG), are the important proteins involved in osteoclastogenesis. In this study, we investigated the expressions of RANKL and OPG in cultured human periodontal ligament cells derived from deciduous teeth (DPDL cells) and their roles in osteoclastogenesis. Northern blotting revealed that the OPG mRNA was down-regulated by application of 10(-8) M 1 alpha, 25(OH)2 vitamin D3 [1,25-(OH)2D3] and 10(-7) M dexamethasone (Dex). In contrast, RANKL mRNA was up-regulated by the same treatment. Western blotting demonstrated a decrease in OPG following application of 1, 25-(OH)2D3 and Dex. Tartrate-resistant acid phosphatase (TRAP)-positive multinuclear cells (MNCs) were induced when DPDL cells were co-cultured with mouse bone marrow cells in the presence of 1,25-(OH)2D3 and Dex. TRAP-positive MNCs increased significantly when the DPDL cells were co-cultured with bone marrow cells in the presence of anti-human OPG antibody together with 1, 25-(OH)2D3 and Dex. These results indicate that PDL cells derived from deciduous teeth synthesize both RANKL and OPG and could regulate the differentiation of osteoclasts.

Animals↗
PubMed2002

Changes in the populations of mitotic and apoptotic cells in white follicles during atresia in hens.

The aim of this study was to determine whether the population of mitotic cells changes in correlation with apoptotic cell population in follicular tissues during atresia of white follicles in hens. Hens were injected with 5-bromo-2'-deoxyuridine (BrdU) 1 h before tissue collection. The small white follicles were classified as healthy follicles and as early or late atretic follicles by histological observation. Mitotic and apoptotic cells were determined by immunocytochemistry for BrdU and terminal deoxytranceferase-mediated dUTP nick end labeling (TUNEL), respectively. The BrdU labeling was observed in some of the granulosa cells and thecal fibroblast-like cells in healthy follicles, whereas the population of the labeled cells was reduced in the granulosa and theca layers of atretic follicles. The image analysis confirmed that the frequency of BrdU-positive cells declined significantly in the granulosa and theca layers of early atretic follicles compared with those of healthy follicles. In contrast, the TUNEL-positive cells were negligible in healthy follicles. However, they were localized in the granulosa and theca layers of early and late atretic follicles, and those in the theca layer were more inside than outside. The frequency of TUNEL-positive cells was significantly increased with the progress of atretic changes. These results suggest that the population of mitotic cells decreases in association with increase of apoptotic cells during the atretic process of white follicles.

Animals↗
PubMed2002

Changes in the population of immunoreactive S-100-positive folliculo-stellate cells in hens during induced molting.

The goal of this study was to determine whether the population of folliculo-stellate (FS) cells in the hen's pituitary change during induced molting. White Leghorn laying hens were subjected to induced molting by feed withdrawal; feeding was resumed on the fourth day after egg laying ceased. The anterior pituitaries were collected from hens at pretreatment, at 3 and 5 d after feed withdrawal and at 3 d after cessation of egg laying, 10 d after cessation of egg laying (6 d after resumption of feeding), on the day of and 1 wk after resumption of egg laying (RL and 1WRL, respectively). Pituitaries were processed to detect FS cells by immunocytochemistry for the S-100 protein. Sections were then examined under a light microscope with an image analysis computer system. S-100 immunoreactive cells were found in the cephalic and caudal lobes of the anterior pituitary in all groups of hens. The majority of S-100 immunoreactive cells formed clusters of cells that faced into the follicle and surrounded the glandular cells with long cytoplasmic processes. The S-100 immunoreactive area in the cephalic lobe was significantly increased in the RL group (P < 0.05), but decreased thereafter in 1WRL group. The S-100-positive cell area in the caudal lobe did not show significant changes during induced molting. These results suggest that FS cell population is likely to increase at the final stage of induced molting and may be involved in control of pituitary functions for the resumption of ovulation.

Animals↗
PubMed2002

Physiological responses during and following karate training in women.

BACKGROUND: The purpose of this study was to examine whether each exercise and an entire karate training session can achieve: 1). accepted training intensity thresholds for effective aerobic capacity training; 2). energy expenditure (EE) thresholds for total body mass and fat weight loss; and, 3). elevation in excess postexercise oxygen consumption (EPOC). METHODS: We investigated physiological responses during 5 types of karate training in female karate practitioners: basic techniques without (S-Basics) and with (M-Basics) movements, sparring techniques without (TECH I) and with (TECH II) an opponent, and kata. RESULTS: The mean percent of maximum oxygen uptake reserve (%VO2R), percent of maximum heart rate (%HRmax), and maximum heart rate reserve (%HRR) for S-Basics were below the accepted threshold and for M-Basics were marginal or above the threshold for increasing VO2max. For TECH I, TECH II, kata, and the entire 70-min practice, the mean %HRmax and %HRR were well above the threshold, however, %VO2R was below the threshold. Although the mean EPOC measured for 5 min immediately following the entire 70-min karate training did not differ from resting VO2. The blood lactate responses to the 5 types of karate exercises ranged from 1.2+/-0.3 to 2.2+/-0.8 mmol L(-1). The mean EE for each karate exercise ranged from 157+/-10 kJ to 314+/-16 kJ. The mean EE for the entire 70 min practice and EPOC were 1120+/-64 kJ and 28+/-2 kJ, respectively. CONCLUSIONS: The training intensities of karate exercises studied in women were light to moderate, effects of karate training on EPOC was minimal, and the mean EE was marginal to the accepted threshold for total body mass and fat weight loss.

Adult↗
PubMed2001

Quantitative detection of bisphenol A and bisphenol A diglycidyl ether metabolites in human plasma by liquid chromatography-electrospray mass spectrometry.

Due to the ubiquity of epoxy resin compounds and their potential role in increasing the risk for reproductive dysfunction and cancer, the need for an assessment of human exposure is urgent. Therefore, we developed a method for measuring bisphenol A (BPA) and bisphenol A diglycidyl ether (BADGE) metabolites in human blood samples using high-performance liquid chromatography-electrospray ionization mass spectrometry (LC-MS). Human blood samples were processed using enzymatic deconjugation of the glucuronides followed by a novel sample preparation procedure using a solid-phase-cartridge column. This selective analytical method permits rapid detection of the metabolites, free BPA and a hydrolysis product of BADGE (BADGE-40H) with detection limits in the low nanogram per milliliter range (0.1 ng ml(-1) of BPA and 0.5 ng ml(-1) of BADGE-40H). The sample extraction was achieved by Oasis HLB column on gradient elution. The recoveries of BPA and BADGE-40H added to human plasma samples were above 70.0% with a standard deviation of less than 5.0%. This selective, sensitive and accurate method will assist in elucidating potential associations between human exposure to epoxy-based compounds and adverse health effects.

Benzhydryl Compounds↗
PubMed2001

Development of sensitive high-performance liquid chromatography with fluorescence detection using 4-(4,5-diphenyl-1H-imidazol-2-yl)-benzoyl chloride as a labeling reagent for determination of bisphenol A in plasma samples.

A sensitive HPLC method for determination of bisphenol A (BPA) in plasma samples using 4-(4,5-diphenyl-1H-imidazol2-yl)benzoyl chloride (DIB-Cl) as a fluorescence labeling reagent was developed. The fluorescence labeling reaction was completed within 10 min at room temperature. DIB-Cl reacts with the phenolic hydroxyl group of BPA in the presence of triethylamine (TEA). The DIB-Cl derivative of BPA (DIB-BPA) was separated within 30 min with an ODS column using acetonitrile-water (90:10, v/v) as the isocratic eluent. Calibration graphs were linear over the range of 1.0-100 ng/ml (r=0.999). The detection limit of DIB-BPA was 0.05 ng/ml (2.5 pg) at a signal-to-noise ratio of 3. The relative standard deviations (RSDs) of the method for between-run were 1.0-5.0%. The analytical recoveries of known amounts (1.0 and 100 ng/ml) of BPA-spiked rabbit plasma were around 95%.

Animals↗
PubMed2001

Observation of the "self-healing" of an error field island in the large helical device.

It was observed that the vacuum magnetic island produced by an external error magnetic field in the large helical device shrank in the presence of plasma. This was evidenced by the disappearance of flat regions in the electron temperature profile obtained by Thomson scattering. This island behavior depended on the magnetic configuration in which the plasmas were produced.

Journal Article↗
PubMed2001

Reduction of ion thermal diffusivity associated with the transition of the radial electric field in neutral-beam-heated plasmas in the large helical device.

Recent large helical device experiments revealed that the transition from ion root to electron root occurred for the first time in neutral-beam-heated discharges, where no nonthermal electrons exist. The measured values of the radial electric field were found to be in qualitative agreement with those estimated by neoclassical theory. A clear reduction of ion thermal diffusivity was observed after the mode transition from ion root to electron root as predicted by neoclassical theory when the neoclassical ion loss is more dominant than the anomalous ion loss.

Journal Article↗
PubMed2001

Observation of rho/omega meson modification in nuclear matter.

We measured the invariant mass spectra of electron-positron pairs in the target rapidity region of 12-GeV p+A reactions. We have observed a significant difference in the mass spectra below the omega meson between p+C and p+Cu interactions. This difference indicates that the spectral shape of mesons is modified at normal nuclear-matter density.

Journal Article↗