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Biomedical subjects

H Yamaguchi

Publications and source records attributed to H Yamaguchi.

At least 271 records · Page 15Linked to original sources
PubMed2000

Troglitazone improves endothelial dysfunction in patients with insulin resistance.

Insulin resistance is a possible major metabolic cause of atherosclerosis. Endothelial dysfunction is commonly found in patients with insulin resistance, and primary treatment of insulin resistance with troglitazone should improve such endothelial dysfunction. Thus, the effects of troglitazone on endothelial function were investigated. Thirteen non-diabetic male subjects with hyperinsulinemic response to oral glucose load (n = 7) and normal (n = 6) subjects were investigated. Flow-mediated dilatation (FMD) of the brachial artery was examined by high resolution ultrasonography before and after the administration of troglitazone of 400 mg for 4 weeks. In insulin resistant subjects, fasting glucose (4.9+/-0.3 to 4.7+/-0.3 mmol/L, p<0.05), insulin (45+/-30 to 25+/-15 pmol/L, p<0.05) and response to oral glucose load (AUC glucose: 15.0+/-3.5 to 13.0+/-2.2 mmol x h/L, p<0.05; AUC insulin: 965+/-560 to 475+/-275 pmol x h/L, p<0.05) were significantly reduced. FMD was significantly improved in insulin resistant subjects. A significant negative correlation was observed between FMD and AUC insulin (r=-0.64, p<0.05). The present study demonstrates that FMD is impaired in insulin resistant subjects, and troglitazone improves the blunted vascular response and impaired insulin response. This finding suggests that primary treatment of insulin resistance could prevent the development of atherosclerosis by improving endothelial dysfunction.

Adult↗
PubMed2000

A case of small polypoid esophageal carcinoma with multidirectional differentiation, including neuroendocrine, squamous, ciliated glandular, and sarcomatous components.

A small composite esophageal carcinoma measuring 1.5 x 1.4 x 1.0 cm is described. The tumor had a polypoid elevation with a superficial extension. Histologic examination revealed invasion of the submucosal layer and multidirectional differentiation, including neuroendocrine, squamous, ciliated glandular, and sarcomatous components. The neuroendocrine component was strongly positive for chromogranin and formed the bulk of the polypoid tumor. The squamous cell carcinoma exhibited a superficial extension. The adenocarcinoma was located in a small region of the tumor and contained ciliated glandular cells. The spindle cell sarcomatous component, which was positive for alpha-smooth muscle actin and negative for cytokeratin, exhibited no specific mesenchymal differentiation. Each component was found in 60%, 10%, 5%, and 25% of the tumor, respectively. Cases of small composite esophageal carcinoma containing various carcinomatous and sarcomatous components are extremely rare.

Actins↗
PubMed2000

In vitro antifungal activity of a novel lipopeptide antifungal agent, FK463, against various fungal pathogens.

The antifungal activities of FK463 against various pathogenic fungi were tested by standard broth microdilution methods, and compared with the activities of five currently available antifungal agents; viz., fluconazole (FLCZ), itraconazole, miconazole, amphotericin B and flucytosine. Fourteen clinical isolates of Candida albicans categorized as FLCZ susceptible, FLCZ susceptible-dose dependent and FLCZ resistant were similarly susceptible to FK463 with geometric (GM) MIC values of 0.010, 0.011 and 0.015 microg/ml, respectively. All of 17 clinical isolates of Aspergillus fumigatus were inhibited by FK463 at 0.0078 microg/ml or lower concentrations. The antifungal activity of FK463 against a wider range of medically important yeasts and filamentous fungi were studied using stock fungal strains. While Cryptococcus, Trichosporon, Fusarium, Pseudallescheria and Alternaria species or zygomycetes were scarcely or not inhibited by 16 microg/ml of FK463, two Candida species (C. albicans, C. glabrata), as well as all species of Aspergillus, Paecilomyces and Penicillium, were highly susceptible with GM-MICs of < or = 0.008 microg/ml. The other fungal species including several non-albicans Candida were less susceptible with GM-MICs ranging between 0.016 and 2 microg/ml. MICs of the reference drugs were within the range thus previously reported. These results suggest that FK463 be of use in the treatment of serious fungal infections.

Antifungal Agents↗
PubMed2000

Cerebral function after aortic surgery using retrograde cerebral perfusion: report of three cases.

INTRODUCTION: The neurological analysis undertaken on three cases of aortic aneurysm treated surgically using retrograde cerebral perfusion (RCP) are reported herein. This is the first detailed analysis of postoperative neurological studies in such cases. METHODS: The oxygenation state of cerebral Hb and cytochrome aa3 levels were monitored by near-infrared spectroscopy (NIR) during RCP. Postoperative neurological scoring, computed tomography (CT), magnetic resonance imaging (MRI), and monitoring of local cerebral blood flow (LCBF) quantatively by N-isopropyl-p-[123I] iodoamphetamine (IMP) single-photon emission computed tomography (SPECT) were performed for an extended follow-up period after surgery. RESULTS: The T2WI of MRI findings which consisted of many spotty high intensity areas in the striatum, cerebellum and hippocampus, may reflect the postoperative severe consciousness and mental disturbances (2-4 weeks). However, in all cases the neurological deficit gradually improved until they returned to their normal preoperative states. The improvement of LCBF correlated well with neurological recovery. CONCLUSION: The conditions of the conventional method of RCP must be improved to prevent transient severe consciousness and mental disturbances which occur after the operation in relationship with the appearance of the high intensity area on the MRI T2WI.

Adult↗
PubMed2000

[Mitral valve regurgitation associated with severe pulmonary hypertension successfully treated with nitric oxide gas: report of a case].

A 61-year-old woman with mitral valve regurgitation and pulmonary hypertension, was referred to us for surgical repair. Preoperative left ventriculography showed Sellers IV mitral valve regurgitation and high pulmonary arterial pressure: 103/31 (57) mmHg. The mitral valve was replaced with a phi 27 mm SJM mechanical valve. The postoperative residual pulmonary hypertension was successfully treated with nitric oxide gas, decreased significantly pulmonary arterial pressure, and the postoperative course was uneventful. Based on our experience, we think that nitric oxide gas may prove effective for residual pulmonary hypertension after a cardiac operation.

Female↗
PubMed2000

Correlation between interventricular septal motion and left ventricular systolic-diastolic function in patients with left bundle branch block.

The echocardiographic correlation between abnormal interventricular septal motion including systolic paradoxical, flat motion and early diastolic notch and ejection fraction, mean ventricular circumferential fiber shortening and early diastolic mitral filling velocity was studied in 46 patients with complete left bundle branch block. Systolic normal interventricular septal motion was used as the control. Ejection fraction was significantly smaller in the paradoxical(0.44 +/- 0.13, p < 0.02) and flat motion groups(0.38 +/- 0.09, p < 0.001) than in the normal group(0.54 +/- 0.1). Mean ventricular circumferential fiber shortening was significantly smaller in the flat motion group than in the normal group(0.72 +/- 0.19 vs 0.99 +/- 0.23 circ/sec, p < 0.002). The size of the notch was significantly smaller in the flat motion group than in the normal group (2.3 +/- 0.2 vs 4.8 +/- 0.8 mm, p < 0.0001). The deceleration rate of the notch was significantly slower in the paradoxical and flat motion groups than in the normal group(37.3 +/- 12.2, 31.3 +/- 8.1 vs 69.1 +/- 2.5 cm/sec, p < 0.0001). Early diastolic mitral filling velocity was slower in the flat motion group than in the other 2 groups. In conclusion, systolic flat interventricular septal motion showed more severe disturbances of left ventricular systolic and diastolic function than paradoxical interventricular septal motion in patients with complete left bundle branch block.

Aged↗
PubMed2000

[Methodology of 80 degrees head-up tilt testing with and without low dose isoproterenol provocation in Japanese patients with neurally mediated syncope].

The usefulness of 80 degrees head-up tilt testing with and without low dose isoproterenol provocation was evaluated for the diagnosis of neurally mediated syncope (NMS) in Japanese. Head-up tilt testing was performed in 114 consecutive patients with clinical diagnoses of NMS (68 men, 46 women, mean age 46 +/- 21 years), and 57 times in 36 healthy volunteers (26 men, 10 women, mean age 31 +/- 8 years) who had no history of syncope or presyncope. Head-up tilt testing used an 80 degrees angle for 30 minutes (passive tilt), and if the passive tilt resulted in negative response, isoproterenol was infused at 0.01-0.02 microgram/kg/min and the tilt repeated for 10 minutes (isoproterenol tilt). A positive response was defined as the development of syncope or a presyncopal state associated with hypotension, bradycardia or cardiac arrest. The sensitivities of passive tilt testing for a positive response after 5-, 10-, 15-, 20-, 25- and 30-minute tilting were 1%, 9%, 14%, 19%, 24%, and 28%, respectively, and specificities after 5-, 10-, 15-, 20-, 25- and 30-minute tilting were 100%, 95%, 91%, 88%, 86%, and 84%, respectively. The sensitivities of isoproterenol tilt testing with 0.01 and 0.02 microgram/kg/min were increased to 37% and 48%, respectively. This improvement was statistically significant between the passive tilt and isoproterenol tilt testing with a dose of 0.02 microgram/kg/min (p < 0.01). However, specificities were comparable with those of the passive tilt testing (84% and 82%, respectively). In conclusion, 80 degrees passive tilt testing for 30 minutes showed a low sensitivity (28%) but acceptable specificity (84%). Low-dose isoproterenol provocation was useful for improving sensitivity (48%) while maintaining a comparable specificity (82%).

Adult↗
PubMed2000

Quality of life in patients over 70 years of age after heart valve replacement.

BACKGROUND: Previous studies on valve replacement in patients over 70 years of age have been concerned with early and long-term outcome. Little is known, however, of the quality of life (QOL) of survivors following surgery. METHODS: Thirty-one consecutive patients, mean age 74.0+/-3.1 years, who underwent heart valve replacement were reviewed and questioned as to their physical and social activities before and after surgery and compared with 75 patients aged less than 70 years old who underwent similar procedures during the same time interval. QOL was measured by using the Rosser distress and disability scores. RESULTS: Hospital mortality in the elderly group was the same as in the younger group (9.7% vs 2.7%, p = 0.121). Median 5-year survival was 79% in the elderly group and 92% in the younger group (p = 0.068). Overall morbidity due to valve-related complications was 3.55%/patient-year in the elderly group and 2. 35%/patient-year in the younger group, and freedom from all valve-related complications at 5 years was 76%, and 83%, respectively (p = 0.202). There were significant improvements in the distress and disability scores postoperatively (mean interval: 32. 4+/-20.4 months). The QOL value rose from 0.960 to 0.981 in the elderly group (p = 0.0004), and from 0.975 to 0.984 in the younger group (p = 0.07), suggesting that the magnitude of improvement in the elderly group was superior to that in the younger group. CONCLUSIONS: Heart valve replacement in patients over the age of 70 years was associated with reasonable early and mid-term morbidity. We believe that significant improvements in the symptoms, functional status, and QOL of the patients can be expected.

Aged↗
PubMed2000

Differences in 20q13.2 copy number between colorectal cancers with and without liver metastasis.

Frequent gains of 20q have been identified recently in many neoplasias, including breast, bladder, ovarian, pancreatic, and colon cancers. A high level of 20q13.2 amplification is associated with poor prognosis in breast cancer. We investigated the copy number of the 20q13.2 region including the ZNF217 oncogene in 17 nonmetastatic colorectal cancers (CRCs), 18 primary CRC tumors with liver metastasis, and 18 metastatic lesions by two-color fluorescence in situ hybridization to evaluate the significance of an increased copy number of 20q13.2 in CRC, especially in those cases with liver metastasis. The frequency of increased relative copy number of the 20q13.2 region was higher in primary and liver metastatic lesions of CRC than in CRC lesions without liver metastasis. In particular, a high-level increase (>3.0-fold) in the relative copy number of 20q13.2 was observed in 2 of 18 (11%) primary CRC lesions with liver metastasis, 7 of 18 (39%) liver metastatic lesions, and in none of the cases of primary CRC without liver metastasis. The absolute and relative copy number of chromosome 20q13.2 was higher in CRCs with metastasis than in CRCs without metastasis. The percentage of cells with high-level 20q13.2 amplification was also higher in both lesions with metastasis per specimen than without metastasis. Our results suggest that the level of 20q13.2 amplification correlates with the metastatic potential and tumor progression of CRC. The results also suggest that 20q13.2 amplification with ZNF217 is associated with increased metastatic potential.

Chromosome Mapping↗
PubMed2000

Induced activity of adenine phosphoribosyltransferase (APRT) in iron-deficiency barley roots: a possible role for phytosiderophore production.

To isolate the genes involved in the response of graminaceous plants to Fe-deficient stress, a protein induced by Fe-deficiency treatment was isolated from barley (Hordeum vulgare L.) roots. Based on the partial amino acid sequence of this protein, a cDNA (HvAPT1) encoding adenine phosphoribosyltransferase (APRT: EC 2.4.2.7) was cloned from a cDNA library prepared from Fe-deficient barley roots. Southern analysis suggested that there were at least two genes encoding APRT in barley. Fe deficiency increased HvAPT1 expression in barley roots and resupplying Fe to the Fe-deficient plants rapidly negated the increase in HvAPT1 mRNA. Analysis of localization of HvAPT1-sGFP fusion proteins in tobacco BY-2 cells indicated that the protein from HvAPT1 was localized in the cytoplasm of cells. Consistent with the results of Northern analysis, the enzymatic activity of APRT in barley roots was remarkably increased by Fe deficiency. This induction of APRT activity by Fe deficiency was also observed in roots of other graminaceous plants such as rye, maize, and rice. In contrast, the induction was not observed to occur in the roots of a non-graminaceous plant, tobacco. Graminaceous plants generally synthesize the mugineic acid family phytosiderophores (MAs) in roots under Fe-deficient conditions. In this paper, a possible role of HvAPT1 in the biosynthesis of MAs related to adenine salvage in the methionine cycle is discussed.

Adenine Phosphoribosyltransferase↗
PubMed2000

Secretory mechanisms of grepafloxacin and levofloxacin in the human intestinal cell line caco-2.

Grepafloxacin and levofloxacin transport by Caco-2 cell monolayers was examined to characterize the intestinal behavior of these quinolones. The levels of transcellular transport of [(14)C]grepafloxacin and [(14)C]levofloxacin from the basolateral to the apical side were greater than those in the opposite direction. The unidirectional transport was inhibited by the presence of excess unlabeled quinolones, accompanied by increased accumulation. The inhibitory effects of cyclosporin A plus grepafloxacin on basolateral-to-apical transcellular transport and cellular accumulation of [(14)C]grepafloxacin were comparable to those of cyclosporin A alone, indicating that the transport of grepafloxacin across the apical membrane was mainly mediated by P-glycoprotein. On the other hand, basolateral-to-apical transcellular transport of [(14)C]levofloxacin in the presence of cyclosporin A was decreased by unlabeled levofloxacin, grepafloxacin, and enoxacin, accompanied by significantly increased cellular accumulation. The organic cation cimetidine, organic anion p-aminohippurate, and the multidrug resistance-related protein (MRP) modulator probenecid did not affect the transcellular transport of [(14)C]grepafloxacin or [(14)C]levofloxacin in the presence of cyclosporin A. The basolateral-to-apical transcellular transport of levofloxacin in the presence of cyclosporin A showed concentration-dependent saturation with an apparent Michaelis constant of 5.6 mM. In conclusion, these results suggested that basolateral-to-apical flux of quinolones was mediated by P-glycoprotein and a specific transport system distinct from organic cation and anion transporters and MRP.

Anti-Infective Agents↗
PubMed2000

Evaluation of body fluid status after cardiac surgery using bioelectrical impedance analysis.

BACKGROUND: In the assessment of fluid status after cardiac surgery, we applied bioelectrical impedance analysis (BIA) to measure the total body water (TBW), extracellular fluid (ECF), and intracellular fluid (ICF), and evaluated its validity. METHODS: Thirty patients who underwent cardiopulmonary bypass (CPB group) and 19 surgical patients not receiving CPB (non-CPB group). RESULTS: The change of BIA values (deltaTBW, deltaECF, deltaICF), body weight and cumulative fluid balance were determined for 120 postoperative hours, and the relationship between BIA values and body weight and fluid balance were evaluated. Postoperative changes in BIA values in the CPB group were compared with those in the non-CPB group. Finally the ECF/ICF ratio and hemodynamic parameters were compared. deltaTBW and deltaECF correlated with changes in body weight and fluid balance, respectively. Especially there was a high correlation in each case although large deviations in the slope of the regression lines were observed. TBW and ECF increased from immediately after operation up to 96 hours (the maximum value was at day 2). On the other hand, ICF decreased from 48 to 72 hours after operation. There were significant high ECF/ICF in the CPB group compared with the non-CPB group from 12 to 72 postoperative hours. We found that ECF/ICF correlated inversely with mean blood pressure, mixed venous oxygen saturation and colloid osmotic pressure, and positively with central venous pressure and pulmonary artery wedge pressure. CONCLUSIONS: It was considered that BIA was useful for evaluating the relative changes in TBW and fluid distribution, and ECF/ICF might be a new parameter for abnormal water metabolism after cardiac surgery.

Aged↗
PubMed2000

[Skeletal muscle T-cell lymphoma following hemophagocytic syndrome].

A 43-year-old man was admitted to our hospital because of hemophagocytic syndrome (HPS) in August, 1998. A CT scan, gallium scintigraphy, gastrofiberscopy and colonofiberscopy showed no evidence of malignant lymphoma. Virus-associated HPS was suspected because of an increased titer of anti-Epstein-Barr (EB) virus antibody (EBV VCA IgG 2,560x, EBV EA IgG 40x, EBNA 20x). The HPS resolved spontaneously for 40 hospital days, but two weeks into the period of HPS remission, the patient developed pain and marked swelling of the right thigh muscle, and pectoral, biceps brachii, quadriceps femoralis and masseter muscles. Otherwise, CT scan and gallium scintigraphy showed no abnormal findings. A biopsy of the right quadriceps femoralis muscle revealed non-Hodgkin's lymphoma with muscle infiltration. Immunohistologic examination confirmed T-cell type (CD3, CD43, CD45, CD45RO) lymphoma, and Southern blot analysis for T-cell receptor revealed a rearranged band. The lymphoma cells were negative for EBV genome monoclonality. The patient responded well to CHOP therapy and achieved a complete remission. This is considered a very rare case of T-cell lymphoma infiltrating multiple skeletal muscles following an episode of hemophagocytic syndrome.

Adult↗
PubMed2000

Natural pathogens of laboratory animals and their effects on research.

The natural fungal pathogens of laboratory animals such as rabbits and guinea pigs are mainly dermatophyte species, most commonly Trichophyton mentagrophytes and also, less frequently Microsporum gypseum and M. canis. However, the incidences of infection and clinical disease are low in well-managed animal facilities. Young or immunocompromised rabbits are thought to be most susceptible. Dermatophytes infect the epidermis and adnexal structures, including hair follicles and shafts, usually on or around the head, and cause pruritus, patchy alopecia, erythema and crusting. Histopathological changes in the underlying skin occur and these changes could confound histological studies involving the skin. Yeast infections usually due to Candida spp. have been reported occasionally in laboratory animals. In this paper, the role of rodents in the evaluation of topical antifungal agents, dermatophytosis and two species of Candida, which are natural pathogens of laboratory animals, are discussed in relation to their effects on research. Pneumocystis carinii, an inhabitant of the respiratory tract of laboratory mice and rats, is a pathogen only under conditions of induced or inherent immunodeficiency. Infected mice and rats are likely to develop severe pneumocystosis following immunosuppression and will be rendered unsuitable for most experimental purposes.

Animals↗
PubMed2000

Mutation induction by heavy ion irradiation of gpt delta transgenic mice.

Using the new transgenic mice produced by mating gpt delta with p53 knockout, mutation induction by heavy-ion irradiation and the effect of p53 background on such induction were studied. After the whole body irradiation with 10 Gy of 135 MeV/u carbon-ion beam, the genomic DNA was isolated from the different organs and the lambda DNA was rescued as a lambda phage. Mutations in the transgene on the lambda DNA were determined by the spi(-) selection (deletion assay). The spi(-) mutation was induced by the above irradiation, but enhancement of the mutant frequency by the knockout of p53 gene was found not in the phages recovered from liver but in those from kidney. We are now making an effort to determine the nature of spi(-) mutation to confirm such p53 effect.

Animals↗