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T Sakurai

Publications and source records attributed to T Sakurai.

At least 667 records · Page 37Linked to original sources

Single radial immunodiffusion of serum apolipoproteins C-II, C-III and E--pretreatment of samples with surfactant.

An assay of apolipoproteins (Apo) C-II, C-III and E in human sera by single radial immunodiffusion (SRID) is described. The procedure involves pretreatment of the serum sample with surfactant to facilitate diffusion of very low density lipoproteins in agarose. This allowed measurement of apolipoproteins in lipidemic sera by SRID in agarose gel. The intraplate coefficient of variation was less than 2.5%, and the interplate coefficient of variation, less than 3.0%. Correlation with double-antibody radioimmunoassay produced the following coefficients of correlation: gamma = 0.9931 (n = 17) for Apo C-II, gamma = 0.9221 (n = 33) for Apo C-III, and gamma = 0.9340 (n = 17) for Apo E.

Apolipoprotein C-II↗

Preparation and spectroscopic studies of cobalt(II)-substituted cucumber basic blue protein "plantacyanin".

The cobalt(II) derivative of cucumber basic blue copper protein "plantacyanin" has been prepared. The visible absorption, circular dichroic and magnetic circular dichroic spectra of Co(II)-plantacyanin are similar to those of Co(II)-plastocyanin, indicating that the stereochemistry of Co(II) is tetrahedral and at least one cysteinyl ligand around Co(II) ion is responsible for the strong charge transfer bands at 331 and ca. 390 nm.

Alcaligenes↗

Sakurai responds.

Explore the source record for details and available documents.

Journal Article↗

Interaction of anti-iron-sulfur protein and anti-ubiquinone binding protein antibodies with complex III of beef heart mitochondria.

Ubiquinol-cytochrome c reductase activity of Complex III was substantially inhibited by anti-iron-sulfur protein antibody, whereas it was not affected by anti-ubiquinone binding protein antibody. Enzyme-linked immunosorbent assay indicated that anti-ubiquinone binding protein antibody do not bind to the complex, but that it binds to Complex III of which iron-sulfur protein and phospholipids have been depleted. These results indicate that some of the antigenic sites of the iron-sulfur protein are located on the surface of Complex III, while the antigenic sites of the ubiquinone binding protein are inaccessible to antibody owing to the interaction with iron-sulfur protein and/or phospholipids in the complex.

Animals↗

An investigation on reduction process of cucumber ascorbate oxidase.

Reduction process of cucumber ascorbate oxidase with L-ascorbate was investigated in detail through absorption and electron paramagnetic resonance (EPR) spectra under anaerobic condition. One of the three type I coppers (the type I copper which is oxidized rapidly (Sakurai, T. et al. (1985) Biochem. Biophys. Res. Commun. 131, 647-652)) and a pair of type III coppers only which contribute to the absorption at 330 nm were reduced faster than other two type I and the other pair of type III coppers, respectively. The principal active site of ascorbate oxidase was confirmed to be comprised of one type I, one type II and a pair of type III coppers. Type II copper seemed to be reduced after all type I and type III coppers have been reduced.

Ascorbate Oxidase↗

High-Mr glycoprotein profiles in human milk serum and fat-globule membrane.

Gradient-polyacrylamide-gel electrophoresis of human milk serum separated three high-Mr glycoprotein bands. The properties of the components corresponding to the three bands (tentatively termed 'Components C, B and A' in their order of migration) were compared by staining with four monoclonal antibodies and lectins. Components B and C both reacted with the four antibodies, but Component A did not. Components B and C were stained with peanut (Arachis hypogaea) agglutinin (PNA) and wheat (Triticum)-germ agglutinin (WGA), Component A being stained with soya-bean (Glycine max) agglutinin as well as PNA and WGA. These results suggest that Components B and C were related molecules, whereas Component A was markedly different from them. The reactivities of Components B and C were the same as those of PAS-0, a high-Mr periodate/Schiff (PAS)-positive glycoprotein previously isolated from human milk fat-globule membrane (MFGM). Component C, whose electrophoretic mobility was the same as PAS-0, could have been a soluble form of PAS-0. A high-Mr glycoprotein having the same properties as Component A was also observed in MFGM. The amino acid composition of the isolated Component A was significantly different from that of Component C and PAS-0, high threonine and serine contents being characteristic of Component A. The carbohydrate content of Component A was 65-80%, and was much higher than that of Component C and PAS-0. Fucose, galactose, N-acetylglucosamine, N-acetylgalactosamine and sialic acid were each detected as constituent sugars of Component A. Component A represents, therefore, a new high-Mr glycoprotein species in human milk serum and MFGM. Since these glycoproteins were high-Mr mucin-like glycoproteins, the names 'HM glycoprotein-A' and 'HM glycoprotein-C' were proposed for Component A and Component C (PAS-O) respectively.

Amino Acids↗

Roles of the two copper ions in bovine serum amine oxidase.

With a view to obtaining information on the roles of the two copper ions in bovine serum amine oxidase (BSAO), spectroscopic and magnetic studies on several BSAO derivatives have been carried out. Cu-depleted BSAO (Cu-depBSAO) exhibits no enzyme activity and only a low absorption intensity at ca. 475 nm, which is the characteristic absorption maximum of the chromophore in BSAO. The binding of 1 mol of Cu to 1 mol of Cu-depBSAO slightly but definitely increases the enzyme activity and the absorptivity, although they are much lower than those of native BSAO. The incorporation of 2 mol of Cu into Cu-depBSAO gives rise to a similar high activity and absorptivity as those of the native enzyme. Electron paramagnetic resonance (EPR) spectra of the BSAO derivatives reveal that two copper ions in the enzyme molecule are environmentally identical. Titrations of BSAO, Cu-depBSAO, and Cu-half-depleted BSAO (Cu-half-depBSAO), containing 1 mol of copper per mole of protein, with phenylhydrazine (an inhibitor of BSAO) indicate that only 1 mol of phenylhydrazine reacts with 1 mol of the enzyme. In other words the enzyme possesses only one chromophore or one active site, though the molecule is composed of two electrophoretically identical subunits. The binding constants between phenylhydrazine and BSAO, Cu-depBSAO, or Cu-half-depBSAO were estimated to be 5 X 10(6), 5 X 10(4), and 1 X 10(5) M-1, respectively. The binding of phenylhydrazine to the chromophore is assisted by the presence of two copper ions by a factor of 100.(ABSTRACT TRUNCATED AT 250 WORDS)

Amine Oxidase (Copper-Containing)↗

A case-control study on the prognosis of vibration syndrome.

A case-control study was undertaken to evaluate some factors affecting the prognosis of vibration-induced white finger (VWF), 286 workers, who had used a chain saw in forests and had showed some symptoms and signs that were suspected to be vibration syndrome during some of the years from 1956 to 1980, were selected by medical examinations from a total of 612 forestry workers, and were divided into four groups according to the prognosis of the VWF based on a twenty-year follow-up. The study shows an association between the prognosis of VWF and vibration components, particularly vibration levels, severity of the syndromes not only in peripheral circulation but also in peripheral neuropathy before exposure to vibration ceased. There are also significant associations between the prognosis of peripheral neuromuscular symptoms and the factors of aging and duration of exposure. The study suggests that smoking habits and history of heart failure and diabetes had no effect on the prognosis of VWF.

Finger Injuries↗

Acute hemodynamic effects of a new inotropic agent, OPC-8212, on severe congestive heart failure.

The hemodynamic and clinical effects of OPC-8212, a newly synthesized, orally effective inotropic agent, were assessed for the first time in ten patients with severe congestive heart failure by means of right heart catheterization with a Swan-Ganz catheter. Cardiac output was determined by the thermodilution technique. Patients received a single oral dose of 6 mg/kg. To determine the magnitude and time-course of the effects of OPC-8212, measurements were made during an observation period before and 2, 4, 8, and 12 h after administration. Blood was also taken at these times for measurement of the concentration of plasma OPC-8212. No large meals were allowed during the first 4 h. After the single oral dose of OPC-8212, plasma concentrations increased rapidly, reaching an effective level after 8 h and peaking at 12 h. Hemodynamic performance improved as the mean OPC-8212 plasma level increased, with the maximum effect being observed between 8 and 12 h after acute administration of the drug. At 8 h, the cardiac index was increased from the baseline value of 2.4 +/- 0.2 (SEM) to 2.8 +/- 0.3 1/min/m2 (P less than 0.01). The stroke work index rose from 26.2 +/- 5.1 to 31.7 +/- 60 g . m/m2. The excessive pulmonary artery diastolic pressure fell from 22 +/- 2 to 17 +/- 3 mmHg at 8 h (P less than 0.001) and to 16 +/- 2 mmHg (P less than 0.001) at 12 h. The incidence of ventricular premature beats was not increased and no other side effects were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

Natural history of intermittent claudication in the Japanese.

The natural history of intermittent claudication (IC) was surveyed in 59 limbs of 44 patients. The mean follow-up period was 3 years (1 to 8.3 years). During the follow-up period, 72.0 per cent of the limbs with a solitary arterial lesion improved or remained unchanged. However, detailed analysis showed that 53.3 per cent of limbs with iliac artery stenosis and 50.0 per cent of those with femoropopliteal artery stenosis worsened, whereas only 18.7 per cent of limbs with iliac artery occlusion and no limbs with femoropopliteal artery occlusion had worsening of symptoms. Of limbs with multiple arterial lesions, 62.5 per cent worsened. Although the natural history of IC is relatively favorable, IC due to a solitary arterial stenosis tends to worsen, whereas IC due to a solitary arterial occlusion will, in more than 80 per cent of cases, improve or remain unchanged. In cases of arterial stenosis, therefore, more careful follow-up, including control of risk factors, is mandatory.

Aged↗

The effect of some anions on the spectral properties of bovine ceruloplasmin.

The effect of binding of N3-, SCN-, OCN-, and F- to bovine ceruloplasmin (Cp) has been studied in detail using absorption, circular dichroic (CD), and electron paramagnetic resonance (EPR) spectroscopies. With the addition of increasing amounts of N3-, SCN-, and OCN- to a Cp solution, the intensity of the band at 614 nm at first increased several percent and then decreased gradually as at least one type I copper was reduced and/or as the type I copper was changed to type II copper. Concomitantly, new bands appeared at 430 and 365 nm for N3-, 435 and 380 nm for SCN-, and about 390 nm for OCN-. A conformational change in the protein induced by the binding of N3-, SCN-, and OCN- to the type II and type III coppers led to the change in the CD spectra. The observed increase of the band at about 430 nm was attributed to the change occurring at the type I copper site. On the other hand, the band at about 370 nm may come from a charge transfer of coordinated anions to the Cu(II) ion. Fluoride ion did not induce the appearance of the band at around 430 and 370 nm, but the parallel component of the type II copper EPR signal was split upon the binding of two fluoride ions to the copper ion.

Animals↗

Transrectal longitudinal ultrasonography of prostatic abscess.

A definite diagnosis of prostatic abscess sometimes is difficult to make. We report 2 cases of prostatic abscess diagnosed with the aid of transrectal longitudinal ultrasonography by electronic linear scanning. Transperineal aspiration of the abscesses was performed easily and correctly with this echographic technique.

Abscess↗

Myocardial relaxation in atrial fibrillation.

Although myocardial contractility has been known to vary from beat to beat in atrial fibrillation, myocardial relaxation in this arrhythmia has not been investigated. In this study, left ventricular relaxation was examined in seven patients with atrial fibrillation (four with mitral valve disease, one with aortic regurgitation, one with secundum type atrial septal defect and one with apical left ventricular hypertrophy). The left ventricular pressure was measured with a micromanometer-tipped catheter and the time constant of isovolumic left ventricular pressure decline (the relaxation time constant) was calculated by means of exponential curve fitting from more than 20 consecutive beats in each patient. The maximal rate of rise of left ventricular pressure (dP/dt) and the relaxation time constant were examined in relation to the preceding RR interval (RR2) and to the ratio of the RR2 interval to the pre-preceding RR interval (RR2/RR1), and the correlation coefficients were obtained. The dP/dt correlated better with RR2/RR1 than with the RR2 interval (0.82 +/- 0.05 versus 0.48 +/- 0.2), but the relaxation time constant did not show any correlation with RR2/RR1 or the RR2 interval (0.03 +/- 0.21 and 0.06 +/- 0.21, respectively). The relaxation time constant was fairly constant in each patient even when the RR2 interval and RR2/RR1 varied greatly. Thus, relaxation in atrial fibrillation is independent of changes in contractility as seen in the relation between postextrasystolic relaxation and postextrasystolic potentiation of contractility.

Adult↗

Gastric functions in patients with the intrathoracic stomach after esophageal surgery.

Functions of the stomach placed in the posterior mediastinum after esophagectomy were studied in 20 esophageal carcinoma patients. Seven were long-term survivors who lived more than 5 years after operation, and five of them showed normal fasting serum gastrin levels and good or fair gastric acid secretion. Of 13 patients who had their operations within 3 years before the study, 11 showed high fasting serum gastrin levels and poor gastric acid secretion. The hepatobiliary and alimentary scintigrams with double isotopes demonstrated a time lag between the excretion of the food from the stomach and the excretion of bile into the bowels, regardless of the postoperative periods. Absorption of vitamin B12 was normal in patients who lived more than 2 years after operation. The intraluminal pressure and pH studies in long-term survivors showed that our operative technique, the posterior invagination esophagogastrostomy, was effective in preventing a gastroesophageal reflux in the anastomosis.

Adult↗

Visualization of moving fluid: quantitative analysis of blood flow velocity using MR imaging.

A new method for the measurement of blood flow using magnetic resonance imaging has been developed. The flow velocities are calculated from the distances that the fluid has moved. The distances are directly visualized by a new pulse sequence. In a phantom study, the measured flow rates showed very good correlation with actual flow rates of up to 20 l/min (3 m/sec). In a volunteer study, pulsatile flow velocities of a large artery were measured with electrocardiographic gating. The flow pattern of a cardiac cycle at the abdominal aorta is similar to that revealed by other methods of measurement, such as Doppler ultrasound. This method allows reasonably accurate quantitative analysis of blood flow in the large arteries.

Blood Flow Velocity↗