Search PubMed⌕ Search

Biomedical subjects

H Okuda

Publications and source records attributed to H Okuda.

At least 307 records · Page 17Linked to original sources
PubMed1987

Transmission of human T cell lymphotropic virus type I by blood transfusion before and after mass screening of sera from seropositive donors.

The human T cell lymphotropic virus type I (HTLV-I) is transmitted by blood transfusions that contain cell components as one of the virus transmission modes. We carried out mass screening of sera from seropositive donors by a gelatin particle agglutination test to prevent the spread of HTLV-I by transfusion. Seroconversion rates were compared before and after screening. The results show a remarkable decrease in the rate of infection from 53.6 to 0.9%. Therefore, it is certain that screening by the agglutination method prevents the spread of HTLV-I transmission in blood transfusions.

Antibodies, Viral↗
PubMed1987

Influence of acidosis on inotropic effect of catecholamines in newborn rabbit hearts.

The influence of acidosis on the inotropic effect of isoproterenol was studied in the isolated arterially perfused heart of the newborn rabbits. Baseline mechanical function during acidosis (pH 6.8) was not different from control (pH 7.4). However, the inotropic effect of isoproterenol was significantly suppressed in the acidotic muscles. The increment of myocardial adenosine 3',5'-cyclic monophosphate (cAMP) content during isoproterenol infusion was also reduced in acidosis. Inotropic effects of Ca and dibutyryl cAMP in the acidotic muscles were not significantly different from those in the control muscles. beta-Receptor number and affinity in the respiratory acidotic muscle was similar to those in the control muscle. Effects of pH on myocardial beta-receptor and adenylate cyclase activity were further determined in the membrane fraction by changing the pH of the reaction medium from 7.4 (control) to 6.8 or 6.0. beta-Receptor numbers were significantly decreased at pH 6.0 but not at pH 6.8. Adenylate cyclase activity was depressed at pH 6.8 and 6.0. These data suggest that the inotropic effect of isoproterenol is diminished in the acidotic muscle. This may be due to the decreased activation of cAMP production, which in turn most likely results from depressed adenylate cyclase activity.

Acidosis↗
PubMed1987

A pseudotumor of the urinary bladder secondary to diverticulitis of the sigmoid colon with colo-vesical fistula: a case report.

A case of pseudotumor of the urinary bladder secondary to diverticulitis of the sigmoid colon with colo-vesical fistula is reported. Computed tomography and cystoscopy of the granulomatous mass caused by the inflammation suggested a colon or bladder cancer. A transurethral biopsy from the tumor was therefore performed at first, but showed only inflammation. Because primary bladder cancer was ruled out, partial cystectomy and partial colectomy were subsequently performed. Through histological examination the mass proved to be an inflammatory granuloma.

Adult↗
PubMed1987

Flow dynamics in the main pulmonary artery after the Fontan procedure in patients with tricuspid atresia or single ventricle.

We analyzed the flow velocity pattern in the main pulmonary artery after Fontan operation in patients with tricuspid atresia (n = 10) or with single ventricle (n = 10) by means of a catheter-mounted velocity probe. The area underneath the velocity signal of the forward flow was integrated, and ratios of the portions during atrial systole and during the diastolic phase to the total area (Fa and Fd) were calculated. The Fa was 0.54 +/- 0.09 in patients with tricuspid atresia and 0.45 +/- 0.05 in those with single ventricle (p less than .01). Cardiac output, obtained by the thermodilution method, was 2.45 +/- 0.48 liters/min/m2 in patients with tricuspid atresia and 2.75 +/- 0.72 liters/min/m2 in those with single ventricle. The forward flow during atrial contraction, calculated by multiplying Fa by cardiac output, was 1.32 +/- 0.35 liters/min/m2 in patients with tricuspid atresia and 1.23 +/- 0.33 liters/min/m2 in those with single ventricle. The diastolic forward flow, calculated from Fd and cardiac output, was 0.99 +/- 0.25 liter/min/m2 in patients with tricuspid atresia and 1.52 +/- 0.45 liters/min/m2 in those with single ventricle (p less than 0.005). The sum of cross-sectional areas of the right and left pulmonary arteries normalized by body surface area (PA index) was 282 +/- 85 cm2/m2 in patients with tricuspid atresia and 462 +/- 65 cm2/m2 in those with single ventricle (p less than .005). The Fa was inversely correlated with the PA index in the whole group (r = -.69) and also in the tricuspid atresia group alone (r = -.87).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Flow Velocity↗
PubMed1987

Development of myocardial contractile system in the fetal rabbit.

Developmental changes in the myocardial contractile system were evaluated in the fetus at 18, 21, and 28 days of gestation (full term 31 days) and in 3- to 5-day-old newborn rabbits. Mechanical function was studied using the isolated arterially perfused heart. Perfusion with ryanodine (10(-5) M), an inhibitor of Ca release from the sarcoplasmic reticulum, decreased contractile force and increased the time to peak tension in the 28-day fetus and newborn but these changes were minimal in the 18- and 21-day fetus. Postextrasystolic potentiation, which is thought to be caused by Ca release from the sarcoplasmic reticulum, was observed in the 28-day fetus and the newborn, but was not significant in the 18- and 21-day fetus. An ultrastructural study showed poorly developed sarcoplasmic reticulum and myofibrils in the 18- and 21-day fetus. Although the maximum developed tension observed at high extracellular calcium increased with development, the relative value of developed tension at various extracellular calcium was similar in the three fetal groups and only in the newborn the extracellular calcium-developed tension curve shifted to the right. Myofibrillar yield increased with development but sensitivity of myofibrillar ATPase activity to Ca was similar in the fetus and newborn. These data suggest that 1) the sarcoplasmic reticulum does not function significantly in the 18- and 21-day fetus, 2) although sarcoplasmic reticulum starts to function at late gestation, it does not cause significant changes in intracellular calcium in the fetal period, 3) myocardial contractility remains similar in the fetus from the 18th to 28th day of gestation and major changes in contractility occur after birth.

Animals↗
PubMed1987

Acute hemodynamic effects of dopamine, dobutamine, and isoproterenol in congested infants or young children with large ventricular septal defect.

We studied the acute hemodynamic effects of dopamine, dobutamine, and isoproterenol in infants and young children with large ventricular septal defect (VSD). Dopamine (5 micrograms/kg/min) had no significant hemodynamic effects. Dobutamine (5 micrograms/kg/min) administration resulted in modest increases in heart rate and systemic arterial pressure and a decrease in left atrial pressure. This drug decreased the pulmonary blood flow, and the pulmonary-to-systemic blood flow (Qp/Qs) ratio, although these changes were not statistically significant. Isoproterenol, infused at doses of 0.03 and 0.06 micrograms/kg/min, increased the heart rate and lowered left atrial pressure. Only the high dose of isoproterenol lowered systemic and pulmonary arterial pressure. The low dose infusion of this drug increased the pulmonary blood flow as well as the systemic flow, whereas the high dose infusion resulted in a decrease of the Qp/Qs ratio without an increase in the pulmonary blood flow. Right atrial pressure was lowered by dobutamine and the high dose of isoproterenol, but the mean change was only 1 to 2 mmHg. The difference of the effects among these catecholamines is due to their relative strength of action on the vascular bed and the myocardium. Although the doses and durations of the drug infusions were limited, these acute hemodynamic effects should be taken into account when they are to be given to congested infants and young children with large VSD.

Dobutamine↗
PubMed1987

Effect of factors besides hyperphagia on cellularity of adipose tissue in gold thioglucose-induced obese mice.

Whether or not factors besides hyperphagia influence cellularity of adipose tissue in gold thioglucose (GTG)-treated mice was examined. The animals were treated with GTG (800 mg/kg body weight) or saline as control. Control and one of the GTG-treated groups were given a diet ad libitum and another of the GTG-treated groups was pair-fed to control. In GTG-treated group fed ad libitum, hyperphagia and obesity were observed and an enlargement in the parametrial adipose tissue was mainly due to increases both in size and number of adipocytes. The GTG-treated group became obese compared to control even if food intake was comparable. The pair-feeding failed to inhibit completely the increase of both size and number of adipocytes in the fat pads. These results suggest that other factors besides hyperphagia might influence changes of cellularity of the parametrial adipose tissue in the GTG-induced obesity.

Adipose Tissue↗
PubMed1987

Use of sulfonated probes for in situ detection of amylase mRNA in formalin-fixed paraffin sections of human pancreas and submaxillary gland.

A sulfonated probe and its applicability to in situ hybridization is described and discussed. The DNA probes were modified by introducing an antigenic sulfone group into the cytidine residues of the denatured DNA (Budowsky EI, Sverdlov ED, Monastyrkaya GS: New method of selective and rapid modification of the cytidine residues. FEBS Lett 25:201, 1972). Hybridization of the sulfonated DNA with the target nucleic acid sequences was confirmed by an avidin-biotin peroxidase complex method using a monoclonal antibody specific to sulfonated DNA. The detection limit of this system was estimated to be about 1.25 pg of actual target sequences by dot blot hybridization analysis. When the sulfonated probes of human amylase cDNA were applied to in situ hybridization immunohistochemistry on formalin-fixed paraffin sections of the human pancreas and submaxillary gland, hybridization signals were clearly localized in the cytoplasm of the acinar cells of the pancreas, and in the serous cells of the submaxillary gland. Suitable probe lengths for in situ hybridization immunohistochemistry were between 100 and 800 bases. The in situ hybridization technique utilizing a sulfonated DNA probe is sensitive, simple, and easy to perform and applicable to studies of cell biology.

Amylases↗
PubMed1987

Structure and function of adenylate kinase isozymes in normal humans and muscular dystrophy patients.

Two isozymes of adenylate kinase from human Duchenne muscular dystrophy serum, one of which was an aberrant form specific to DMD patients, were separated by Blue Sepharose CL-6B affinity chromatography. The separated aberrant form possessed a molecular weight of 98,000 +/- 1,500, whereas the normal serum isozyme had a weight of 87,000 +/- 1,600, as determined by SDS-polyacrylamide gel electrophoresis, gel filtration, and sedimentation equilibrium. The sedimentation coefficients were 5.8 S and 5.6 S for the aberrant form and the normal form, respectively. Both serum isozymes are tetramers. The subunit size of the aberrant isozyme (Mr = 24,700) was very similar to that of the normal human liver isozyme, and the subunit size of the normal isozyme (Mr = 21,700) was very similar to that of the normal human muscle enzyme. The amino acid composition of the normal serum isozyme was similar to that of the muscle-type enzyme, and that of the aberrant isozyme was similar to that of the liver enzyme, with some exceptions in both cases.

Adenylate Kinase↗
PubMed1987

Parathyroid hormone-induced lipolysis in human adipose tissue.

Relative lipolytic activity of human parathyroid hormone-(1-34) (hPTH-(1-34], hPTH-(3-34), desamino-Ser1-hPTH-(1-34), and rat PTH-(1-34) was compared in human subcutaneous adipose tissues in vitro. Human PTH-(1-34), rat PTH-(1-34), and desamino-Ser1-hPTH-(1-34) stimulated in vitro lipolysis significantly above basal level at the concentration of 10(-6) M. Average increments of lipolytic rate were 2.39, 1.82, and 0.87 mumol/g per 2 hr, respectively, being significantly different among the three groups. On the other hand, hPTH-(3-34)-induced lipolytic rate was 0.83 +/- 0.18 mumol/g per 2 hr, not significantly different from the basal level (0.71 +/- 0.20 mumol/g per 2 hr). The effect of hPTH-(3-34) on glycerol release stimulated by hPTH-(1-34), isoproterenol, or forskolin was subsequently investigated. Human PTH-(3-34) produced a dose-dependent inhibition of hPTH-(1-34)-stimulated lipolysis. In contrast, isoproterenol- and forskolin-induced lipolytic rates were not influenced by hPTH-(3-34). The effect of propranolol on hPTH-(1-34)- or isoproterenol-induced lipolysis was also studied. Propranolol dose-dependently inhibited isoproterenol-induced lipolysis but had no effect on lipolysis stimulated by hPTH-(1-34). These results suggest that the amino acids at positions 1 (serine) and 2 (valine) of PTH are critical for the stimulation of lipolysis in human adipose tissue. Human PTH-(1-34) causes lipolysis after binding to receptors distinct from beta-adrenergic receptors of fat cells and possibly hPTH-(3-34) inhibits hPTH-(1-34)-stimulated lipolysis by competing at the level of PTH receptor.

Adipose Tissue↗
PubMed1986

Hepatic triacylglycerol lipase in circulating blood of normal and tumor-bearing mice and its hydrolysis of very-low-density lipoprotein and synthetic acylglycerols.

A large amount of triacylglycerol lipase activity was present in the circulating blood of normal mice, and this activity decreased with development of Sarcoma 180 inoculated intraperitoneally. Triacylglycerol lipase in plasma of both normal and tumor-bearing mice was retained on the heparin-Sepharose columns and over 90% of the activity was eluted with 0.75 M NaCl. This enzyme had similar properties to hepatic triacylglycerol lipase and hydrolyzed very-low-density lipoprotein (VLDL)-triacylglycerol. Hepatic triacylglycerol lipase in plasma of normal mice hydrolyzed tricaprin and trilaurin most readily and better than 1-monoacylglycerols with the same acyl chain length. The hydrolyzing activities decreased with increase in the acyl chain length. The activity toward triolein was also higher than that toward 1-monoolein. 1-Monomyristin was hydrolyzed better than trimyristin. In contrast, hepatic triacylglycerol lipase in plasma of mice on day 4 after tumor inoculation hydrolyzed 1-monoacylglycerols better than triacylglycerols with the same acyl chain length. Hydrolysis of triolein by hepatic triacylglycerol lipase in plasma of both normal and tumor-bearing mice was reduced in the presence of 1-monoacylglycerols in the reaction mixture. The orders of their inhibitory effects coincided with the orders of the hydrolyzing activities toward 1-monoacylglycerols.

Animals↗
PubMed1986

Covalent binding of a mercaptan S-sulfate to hepatic cytosolic proteins and its inhibition by glutathione.

4-Nitrobenzyl mercaptan (NBM) S-sulfate, a new type of the sulfate conjugate enzymatically formed from NBM in the presence of 3'-phosphoadenosine 5'-phosphosulfate in rat liver cytosol, bound covalently to rat liver cytosolic proteins at pH 7.4. The protein binding of NBM S-sulfate was strongly retarded by GSH. GSH not only played a role as a scavenger for NBM S-sulfate with formation of NBM and GSSG via S-(4-nitrobenzyl)thioglutathione, but also cleaved the covalent bonds, possibly disulfides formed from NBM S-sulfate and sulfhydryl groups of the cytosolic proteins. Thus, evidence was provided that NBM S-sulfate be a new type of the reactive metabolite.

Animals↗
PubMed1986

Right and left ventricular volume characteristics after external conduit repair (Rastelli procedure) for cyanotic congenital heart disease.

We studied right and left ventricular (RV and LV) volume characteristics in 18 patients who had undergone an external conduit repair (Rastelli procedure) at 3-17 years of age (mean 7.5 years). Cardiac output, measured by means of a thermodilution method, was 3.8 +/- 0.8 1/min/m2 (mean +/- SD). Peak RV pressure was 104 +/- 28 mmHg in six patients who had been operated on 6 years or more before this study, significantly higher than in patients with a shorter follow-up period (72 +/- 19 mmHg for 1-5 years follow-up in six patients and 54 +/- 10 mmHg at 1 month after operation in six patients). RV end-diastolic volume (EDV) was 113% +/- 40% of normal, and RV ejection fraction (EF) was 0.52 +/- 0.10, lower than normal. RVEDV was inversely correlated with peak RV pressure (r = -0.78). This parameter was 0.42 +/- 0.06 in the six patients with the longest follow-up period, lower than in the other two groups (0.52 +/- 0.08 in 1-5 years follow-up, 0.60 +/- 0.03 at 1 month after surgery). LVEF was 151% +/- 38% of normal. LVEF was lower than normal in 6 of 12 patients who underwent surgery at the age of 6 years or more and in none of the six younger patients. The data indicate that in these patients, RVEF decreases with the increase of peak RV pressure and the increase in time since operation, especially 6 years or more after surgery. LV pump function is also depressed, possibly partly because of longstanding pre-operative hypoxemia.

Adolescent↗