Search PubMed⌕ Search

Biomedical subjects

S Ueda

Publications and source records attributed to S Ueda.

At least 325 records · Page 18Linked to original sources
PubMed1996

Relationship between severity of mitral regurgitation and prognosis of mitral valve prolapse: echocardiographic follow-up study.

We investigated the relation between the severity of mitral regurgitation and the development of complications and cardiac events by using two-dimensional and color Doppler echocardiography in 229 consecutive patients with mitral valve prolapse. The frequency of moderate and severe mitral regurgitation was significantly higher in patients with a prolapsed posterior leaflet (61%) than in patients with a prolapsed anterior leaflet (25%), and the older the patient, the greater the severity of mitral regurgitation. The occurrence of complications, such as atrial fibrillation, congestive heart failure, and chordal rupture, was significantly greater in prolapsed posterior leaflet cases than in prolapsed anterior leaflet cases, and the occurrence was closely associated with the degree of severity of mitral regurgitation. Multiple logistic regression analysis showed that the severity of mitral regurgitation is a strong prognostic indicator for developing complications. Furthermore in a subgroup of 49 patients tracked for a mean of 4.8 years, the new development of complications was significantly higher in patients who showed a progression in the severity of mitral regurgitation (52%) that in patients without progression in severity (8%). The initial severity of mitral regurgitation was related to the occurrence of cardiac events (mitral valve replacement, infective endocarditis, cerebral embolism and death). The data indicated that the progression of mitral regurgitation is closely associated with the development of complications and cardiac events and suggest that the severity of mitral regurgitation is an important prognostic indicator for the development of complications and cardiac events in patients with mitral valve prolapse.

Adolescent↗
PubMed1996

Endosonographic characterization of duodenal elevated lesions.

BACKGROUND: Endoscopic diagnosis of duodenal elevated lesions is problematic for two reasons. Endoscopic biopsy often fails to confirm a histologic diagnosis of submucosal lesions. Moreover, a biopsy specimen is often insufficient to verify a differential diagnosis of mucosal lesions. In this study, we evaluated the usefulness of endosonography in the resolution of these problems. METHODS: The endoscopic and endosonographic features of 15 duodenal elevated lesions that had been confirmed histologically in our hospital were reviewed retrospectively. RESULTS: Of the 15 cases, 8 were submucosal lesions (lipoma, Brunner's gland hyperplasia, lymphangioma, carcinoid tumors, leiomyoma, and malignant lymphoma); the rest were mucosal lesions. A correct histologic diagnosis based on endoscopic biopsies was obtained in only 6 cases (three submucosal lesions and three mucosal lesions). On the other hand, ultrasonography was useful in the characterization of all submucosal lesions based on their echo level, layer of origin, and tissue homogeneity. As for mucosal lesions, the depth of infiltration was correctly estimated with endosonography. Either endoscopic resection or surgery was selected on the basis of endosonographic information. CONCLUSIONS: We conclude that endosonography is useful in the differential diagnosis of submucosal lesions and in determining suitable treatment methods for duodenal mucosal and submucosal lesions.

Biopsy↗
PubMed1996

Endoscopic resection of gastrointestinal submucosal lesions: a comparison between strip biopsy and aspiration lumpectomy.

BACKGROUND: Endoscopic diagnosis and treatment of gastrointestinal submucosal lesions is still not established. We evaluated the clinical usefulness of two resection methods for submucosal lesions, using a "nonrandomized surgeon" design. METHODS: The strip biopsy method was evaluated at Tenri Hospital and the aspiration lumpectomy method was used at Kyoto University Hospital. The inclusion criteria for selecting patients were endosonographic findings indicating a tumor location within the submucosa. RESULTS: Seventy-seven patients were treated. The size of the specimens (mean +/- SEM) was 20.7 +/- 0.9 mm for the aspiration lumpectomy group and 14.0 +/- 0.8 mm for the strip biopsy group (p < 0.01). Aspiration lumpectomy was adequate for a definitive histologic diagnosis in 95% of the cases (36 of 38) as compared with 77% (30 to 39) of the cases treated by strip biopsy (p = 0.047). The eradication rate was 87% for the aspiration lumpectomy group, and 74% for the strip biopsy group (p = 0.274). The complication rate resulting from these procedures (hemorrhage, mean 5%) was acceptable. Repeated endoscopic examinations revealed no recurrence except for one lymphangioma. CONCLUSIONS: Endoscopic resection, especially aspiration lumpectomy, provides a significant benefit for accurate final diagnosis and eradication of submucosal lesions.

Adolescent↗
PubMed1996

Discrimination of brain abscess from necrotic or cystic tumors by diffusion-weighted echo planar imaging.

Diagnostic difficulties in discriminating brain abscess from necrotic or cystic tumors using conventional CT and MRI have been reported. In this article, we examine the diagnostic ability of diffusion-weighted imaging to discriminate brain abscess from necrotic or cystic tumors. In previous reports, necrotic or cystic tumors show low signal intensity in diffusion-weighted imaging, indicating a high apparent diffusion coefficient (ADC). In contrast, in our study, high signal intensity was observed in the abscess fluid, associated with low ADC.

Brain Abscess↗
PubMed1996

In-vitro metabolic studies of tacrolimus using precision-cut rat and human liver slices.

The objective of this study was to investigate the in-vitro metabolism of tacrolimus in liver slices from rats and humans. [14C]Tacrolimus (2 or 20 microM) was incubated with precision-cut human and rat liver slices in 12-well plates for up to 12 h. Concentrations of tacrolimus and metabolites were determined by high-performance liquid chromatography (HPLC) radiochromatography. The 13-O-demethylated tacrolimus metabolite (M-I) was the major oxidative metabolite in both rat and human liver slices. The other primary metabolites of tacrolimus (M-II, M-III, and M-IV) were not seen in either species. Unidentified peaks, which eluted early in the HPLC system, were probably due to secondary or conjugated metabolites. The eluate had no pharmacological activity. The finding that M-I was the major tacrolimus metabolite in both human and rat liver slice preparations is consistent with previous studies of rat and human liver microsomes.

Adolescent↗
PubMed1996

Potential confounding effect of hand-warming on the measurement of insulin sensitivity.

1. Hand-warming is employed during metabolic studies to "arterialize' venous blood, but also has systemic haemodynamic effects. Study 1 aimed to determine if hand-warming affects the value for whole-body insulin sensitivity derived from the hyperinsulinaemic euglycaemic clamp technique. Study 2 was designed to assess the effect of hand-warming on contralateral forearm blood flow. 2. In study 1, eight healthy male subjects attended for four modified euglycaemic clamp studies, during which the right hand was placed in a heated-air hand box (55 degrees C), and the glucose infusion rate was adjusted according to blood samples from a cannula in either an ipsilateral dorsal hand vein or a contralateral antecubital vein with the box switched either on or off. In study 2, five healthy subjects attended two study days when the effect of 2 h of hand-warming (or control) on contralateral forewarm blood flow was measured. 3. Study 1; when clamps were performed according to samples taken from the contralateral antecubital vein, insulin sensitivity values were significantly lower during box-on versus box-off clamps (mean +/- SD 10.2 +/- 3.0 versus 13.0 +/- 3.8 mg min-1 kg-1, P < 0.05, 95% confidence interval -0.2, -5.3). When clamps were performed according to samples taken from the ipsilateral hand, there was no difference in insulin sensitivity during box-on versus box-off clamps (9.2 +/- 2.1 versus 9.0 +/- 1.7 mg min-1 kg-1, P not significant, 95% confidence interval -0.5, +0.9). There was a mean increase in heart rate of 6 beats/min in the box-on conditions (P < 0.05, analysis of variance). Study 2; forearm blood flow in the contralateral arm during hand-warming was significantly higher than in the control condition (P < 0.05, analysis of variance), although heart rate was similar on both study days. 4. Hand-warming had a detectable effect on insulin sensitivity when clamps were performed according to samples withdrawn from the contralateral arm, but no measurable effect when clamps were performed in the conventional manner. In addition, hand-warming increased heart rate during hyperinsulinaemia and contralateral FBF under basal conditions. These findings raise concern about unwanted (potentially confounding) systemic haemodynamic effects of hand-warming on the measurement of insulin sensitivity and insulin-mediated vasodilation.

Blood Glucose↗
PubMed1996

Microwave coagulation therapy for hepatocellular carcinoma.

BACKGROUND & AIMS: Surgical resection is not always feasible in patients with hepatocellular carcinoma. Microwave coagulation therapy has been used as an alternative to resection, and its efficacy has been evaluated. METHODS: Nineteen patients with unresectable hepatocellular carcinoma underwent microwave coagulation therapy through laparotomy (n = 12), laparoscopy (n = 5), or thoracotomy (n = 2) because of advanced liver cirrhosis and/or intrahepatic metastases. One nodule was treated in 13 patients, tumor size ranged from 5 to 90 mm. Patient outcomes were studied. RESULTS: Microwave coagulation therapy created a reproducible regional necrosis. Fourteen patients underwent potentially curative treatment; the remaining 5 patients underwent palliative treatment (n = 4) or incomplete tumor coagulation (n = 1). Of the 31 nodules treated, 28 underwent complete tumor ablation. Only 2 patients undergoing laparoscopic microwave coagulation therapy developed local recurrence. The coagulated area subsequently shrank. Patients showed rapid recovery without hepatic dysfunction. Thirteen patients, including 2 long-term survivors, are alive either without tumor (n = 10; 14-64 months) or with tumor (n = 3; 17-22 months). Six patients died of hepatocellular carcinoma (n = 4) or liver insufficiency (n = 2). CONCLUSIONS: This preliminary study suggests the efficacy of microwave coagulation therapy, including safety and potential curability, in patients with hepatocellular carcinoma with advanced liver cirrhosis and multifocal or central tumors.

Adult↗
PubMed1996

Cloning and expression of the canine interferon-beta gene.

We isolated the canine interferon-beta (IFN-beta) gene from dog liver chromosomal DNA by the polymerase chain reaction (PCR). The coding region encodes a predicted protein of 197 amino acids, consisting of a signal sequence of 32 amino acids and a mature IFN-beta of 165 amino acids. In the IFN-beta sequence, there are five potential N-glycosylation sites and four cysteine residues. Canine IFN-beta has 44% and 60% amino acid sequence homology with murine and human IFN-beta, respectively, whereas it has only 28% homology with canine IFN-alpha. The canine IFN-beta gene was expressed in insect cells under the control of the polyhedrin promoter in a recombinant baculovirus. After infecting Sf21 cells with the recombinant baculovirus, IFN activity was detected in the culture medium, indicating that it is secreted from the cells. This activity was stable from pH 2 to 12 for 18 h at 4 degrees C. Southern blot analysis indicated that the gene for canine IFN-beta is a single gene in the dog haploid chromosome.

Amino Acid Sequence↗
PubMed1996

Differences in response of thyrotropin to 3,5,3'-triiodothyronine and 3,5,3'-triiodothyroacetic acid in patients with resistance to thyroid hormone.

This study investigated the response of TSH secretion to 3,5,3'-triiodothyronine (T3) and 3,5,3'-triiodothyroacetic acid (Triac) in patients with resistance to thyroid hormone, and compared the responses with those in patients with TSH-secreting pituitary adenoma and normal subjects. A short-term administration of 75 microg of T3 daily for 7 days suppressed serum TSH concentrations almost completely in normal subjects, but suppressed TSH only partially in patients with resistance to thyroid hormone and TSH-secreting pituitary adenoma. A single-dose administration of 75 microg of T3 gave similar results in regard to TSH suppressibility in these three subjects groups. In contrast, a single-dose administration of 1.4 mg of Triac remarkably suppressed serum TSH concentrations after 2 hours in not only normal subjects (-34 +/- 11% [mean +/- SD] from the basal value) but also in patients with resistance to thyroid hormone (-31 +/- 9%), and this TSH suppression continued for 4 hours. After 24 hours, this TSH suppression persisted in normal subjects (-62 +/- 12%) but was relieved in patients with resistance to thyroid hormone (-23 +/- 14%). After the Triac administration, molar ratios of alpha-subunit to TSH in serum were decreased in patients with TSH-secreting pituitary adenoma but increased in patients with resistance to thyroid hormone. Because the Triac therapy for patients with resistance to thyroid hormone suppressed pituitary-TSH secretion during the early phase of drug ingestion, this drug should be given several times within a day to obtain continuous TSH-suppressive effects.

Adenoma↗
PubMed1996

Chronological positron emission tomographic study of severe diffuse brain injury in the chronic stage.

Cerebral blood flow and metabolism were investigated in five patients with severe diffuse brain injury in the chronic stage, using positron emission tomography (PET). Regional cerebral blood flow, regional oxygen extraction fraction, regional cerebral blood volume, regional cerebral metabolic rate for oxygen, and regional cerebral metabolic rate for glucose were measured bilaterally in the frontal, temporal, occipital, and parietal gray matter, as well as the white matter of the centrum semiovale. In 4 of 5 patients, a follow-up PET study was also performed. In three cases, below-normal regional cerebral blood flow and regional cerebral metabolic rate for oxygen values accompanied by above-normal regional oxygen extraction fraction values, as well as low metabolism, were demonstrated in the initial PET studies. In two of three cases, clinical improvements were observed, and follow-up PET data also improved. These findings suggest that chronological PET studies may be able to assess quantitatively clinical improvements in patients with diffuse brain injury.

Adult↗
PubMed1996

Effect of cyclosporin A on isolated rabbit bladder and urethral smooth muscle.

BACKGROUND: The effects of Cyclosporin A (CsA) on vascular smooth muscle inducing hypertension have been established. However, there is no information available concerning the effects of CsA on urinary smooth muscle. Therefore, the effects of CsA were investigated on the bladder and urethral smooth muscle in rabbits. METHODS: CsA (10 mg/kg/day, intravenously) was given to rabbits for 14 days. Rabbit bladder and urethral smooth muscles were then isolated and evaluated using a muscle bath technique. RESULTS: 10(-10)-5 x 10(-6)M CsA alone had no direct effect on bladder or urethral smooth muscles. The Emax (maximum contractile response) and ED50 values for acetylcholine-induced contractions and the Emax (maximum relaxation response) for isoproterenol-induced relaxation in bladder smooth muscles were not significantly different between CsA-treated and control groups. The ED50 for isoproterenol-induced relaxation was significantly lower in the CsA group (P < 0.05). The Emax for phenylephrine- and clonidine-induced contractions in urethral smooth muscle was significantly higher in the CsA-treated group (P < 0.05). The ratio of the maximum response of the urethral smooth muscle to phenylephrine and clonidine in Ca+2-free solution to the normal solution in the CsA group (13.42% and 4.40%, respectively) was significantly higher than the maximal response ratios in the control group (6.34% and 3.00%, respectively; P < 0.05). CONCLUSIONS: CsA treatment augments the relaxation response of the bladder to isoproterenol and the contractile response of the urethra to phenylephrine and clonidine. In addition, CsA increases the filling of intracellular stores of releasable Ca+2, and also increases the permeability of Ca+2 in rabbit urethral smooth muscle. Thus, it is suggested that CsA may cause a urinary disturbance in patients treated with CsA via increased urethral resistance.

Acetylcholine↗
PubMed1996

Subcapsular hematoma and hypertension following percutaneous needle biopsy of a transplanted kidney.

Percutaneous needle biopsy of a transplanted kidney is indicated as a diagnostic procedure in the evaluation of unexplained deteriorated renal function after renal transplantation. This procedure is not always without complications. We report a case of a subcapsular hematoma and hypertension following a percutaneous needle biopsy of a transplanted kidney. The cause of hypertension in this patient and the management of the subcapsular hematoma are discussed.

Adult↗
PubMed1996

Latex agglutination test for canine parvovirus.

Canine parvovirus (CPV) was detected in faeces from dogs with diarrhoea by a specific slide agglutination test using latex particles coated with anti-CPV monoclonal antibody (LA-anti-CPV). The agglutination of LA-anti-CPV with CPV on a glass slide was evident macroscopically within 2 min. The sensitivity of the latex agglutination (LA) test was similar to that of the hemagglutination test. The LA test is available for the rapid diagnosis of CPV infection at an animal hospital.

Animals↗
PubMed1996

Regulation of RNA polymerase sigma subunit synthesis in Escherichia coli: intracellular levels of four species of sigma subunit under various growth conditions.

By a quantitative Western immunoblot analysis, the intracellular levels of two principal sigma subunits, sigma 70 (sigma D, the rpoD gene product) and sigma 38 (sigma S, the rpoS gene product), and of two minor sigma subunits, sigma 54 (sigma N, the rpoN gene product) and sigma 28 (sigma F, the rpoF gene product), were determined in two Escherichia coli strains, W3110 and MC4100. The results indicated that the levels of sigma 54 and sigma 28 are maintained at 10 and 50%, respectively, of the level of sigma 70 in both strains growing at both exponential and stationary phases, but in agreement with the previous measurement for strain MC4100 (M. Jishage and A. Ishihama, J. Bacteriol. 177:6832-6835, 1995), the level of sigma 38 was undetectable at the exponential growth phase but increased at 30% of the level of sigma 70 at the stationary phase. Stress-coupled change in the intracellular level was observed for two sigma subunits: (i) the increase in sigma 38 level and the decrease in sigma 28 level upon exposure to heat shock at the exponential phase and (ii) the increase in sigma 38 level under high-osmolality conditions at both the exponential and stationary phases.

Bacterial Proteins↗
PubMed1996

Molecular analysis of the poly(3-hydroxyalkanoate) synthase gene from a methylotrophic bacterium, Paracoccus denitrificans.

A 3.6-kb EcoRI-SalI fragment of Paracoccus denitrificans DNA hybridized with a DNA probe carrying the poly(3-hydroxyalkanoate) (PHA) synthase gene (phaC) of Alcaligenes eutrophus. Nucleotide sequence analysis of this region showed the presence of a 1,872-bp open reading frame (ORF), which corresponded to a polypeptide with a molecular weight of 69,537. Upstream of the ORF, a promoter-like sequence was found. Escherichia coli carrying the fusion gene between lacZ and the ORF accumulated a level of poly(3-hydroxybutyrate) that was as much as 20 wt% of the cell dry weight in the presence of beta-ketothiolase and acetoacetylcoenzyme A reductase genes of A. eutrophus. The ORF was designated phaCPd. A plasmid vector carrying the phaCPd'-'lacZ fusion gene downstream of the promoter-like sequence expressed beta-galactosidase activity in P. denitrificans. When a multicopy and broad-host-range vector carrying the ORF along with the promoter-like sequence was introduced into P. denitrificans, the PHA content in the cells increased by twofold compared with cells carrying only a vector sequence.

Acyltransferases↗
PubMed1996

Sensitivity of volume-sensitive Cl- conductance in human epithelial cells to extracellular nucleotides.

The sensitivity to extracellular nucleotides of volume-sensitive Cl- channel activity was investigated by whole cell and single-channel patch-clamp recordings in a human small intestinal epithelial cell line (Intestine 407) during steady osmotic swelling. Adenine nucleotides added to the bathing solution suppressed whole cell volume-sensitive Cl- currents with the potency sequence of ATP > ADP > AMP. In contrast, extracellular adenosine 3',5'-cyclic monophosphate (cAMP) at over 0.1 mM increased volume-sensitive Cl- currents in the entire voltage range examined, whereas guanosine 3',5'-cyclic monophosphate was without effect. Neither the single-channel conductance nor the open probability was affected by extracellular cAMP. Extracellular ATP (at over 30 microM), in the Mg(2+)-free form, inhibited the whole cell volume-sensitive Cl- current, preferentially in the outward direction. By exposure to extracellular ATP, the single Cl- channel current became flickery at positive potentials. These results indicate that the volume-sensitive Cl- channel in the human epithelial cell is stimulated voltage independently by extracellular cAMP but blocked voltage dependently by the Mg(2+)-free form of extracellular ATP.

Adenosine Diphosphate↗