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Biomedical subjects

N Yui

Publications and source records attributed to N Yui.

At least 91 records · Page 5Linked to original sources
PubMed1987

Hemodynamic effect of oral TA-064 after dobutamine in congestive heart failure.

The hemodynamic effect of oral TA-064 (20 mg), a newly synthesized inotropic agent, was compared with that of intravenous dobutamine (5 micrograms/kg/min) in eight patients with congestive heart failure who had been treated with intravenous dobutamine, digitalis, diuretics, and prazosin. Hemodynamics was measured using a Swan-Ganz catheter during the pre-dobutamine control period, during dobutamine infusion period, during the pre-TA-064 control period and at 90 minutes after oral administration of TA-064. Stroke work index was increased and mean pulmonary capillary wedge pressure was decreased with TA-064 or dobutamine. Cardiac index and stroke index was increased by each drug, and pulmonary and systemic vascular resistances were decreased. Mean systemic arterial pressure, heart rate and pressure-rate product did not significantly change in comparison with the control level. In conclusion, TA-064 has a hemodynamic effect similar to that of dobutamine and may be useful as an oral substitute for dobutamine in patients with congestive heart failure after temporary management with dobutamine.

Administration, Oral↗
PubMed1986

Vasodilator therapy with a new stable prostacyclin analog, OP-41483, for congestive heart failure due to coronary artery disease and comparison of hemodynamic effects and platelet aggregation with nitroprusside.

A new stable prostacyclin analog, OP-41483, was used in patients with severe congestive heart failure (CHF) due to coronary artery disease and compared with nitroprusside. During infusion of both drugs, mean brachial arterial pressure, total pulmonary resistance, pulmonary artery wedge pressure and systemic vascular resistance decreased significantly. Cardiac index and stroke index also increased significantly. Platelet aggregation did not change significantly during nitroprusside but decreased significantly with OP-41483 infusion. Thus, this analog may be useful for treatment of patients with CHF due to coronary artery disease.

Aged↗
PubMed1986

Effect of microstructure of poly(propylene-oxide)-segmented polyamides on platelet adhesion.

The relationship between microstructure and platelet adhesivity of six types of poly(propylene oxide) (PPO)-segmented polyamides based on the polyamide segments nylon 210, 310, 410, 510, 610, and 710 were investigated. These multiblock PPO-segmented copolymers were prepared by interfacial polycondensation. Physical characterization of these copolymers was by means of thermal analysis, transmission electron microscope, wide-angle X-ray diffraction (WAXD), and small-angle X-ray scattering (SAXS). The WAXD and SAXS measurements showed that the copolymers had microstructures containing crystalline and amorphous phases and that these microstructures, represented by means of crystallite thickness and long period, varied with incorporation of PPO segments. Blood compatibility of these copolymers was evaluated by estimating the amount of adhering platelets on the copolymer surfaces. The amount of adhering platelets was minimum for the surfaces of the copolymers having a crystallite thickness of 6.0-6.5 nm and a long period of 12-13 nm. This result suggests that the particular size and distribution of the crystalline and amorphous phases in the copolymer could be determining factors for suppressing platelet adhesion on the copolymer surface, and that the control of these factors could lead to ideal antithrombogenic polymers.

Animals↗
PubMed1986

Altered platelet alpha 2 adrenoreceptor in acute myocardial infarction and its relation to plasma catecholamine concentrations.

Changes in platelet alpha 2 adrenoreceptors and their relation to plasma catecholamine concentrations were studied in 11 patients with acute transmural myocardial infarction. A radiolabelled alpha 2 adrenoreceptor antagonist, [3H]-yohimbine, was used to assay alpha 2 adrenoreceptors on platelet membranes, and plasma catecholamine concentrations were measured by high performance liquid chromatography. The number of platelet alpha 2 adrenoreceptors, the dissociation constant, and plasma noradrenaline and adrenaline concentrations were studied 6.6 (3.3) (mean (SD)) hours after the onset of acute myocardial infarction and one month later. The mean (SD) number of adrenoreceptors increased significantly from 94.5 (50.5) fmol/mg protein immediately after infarction to 157.0 (65.7) fmol/mg protein one month later. The dissociation constant, however, did not change significantly (4.33 (1.40) nmol/l vs 4.37 (1.22) nmol/l). Raised noradrenaline (5.60 (4.37) nmol/l) and adrenaline (0.28 (0.14) nmol/l) concentrations had fallen significantly to normal values (1.21 (0.67) and 0.09 (0.05) nmol/l respectively) a month after infarction. The decrease in the number of alpha 2 adrenoreceptors soon after infarction may be beneficial because such a change will reduce the strength of various reactions to catecholamines, such as vasoconstriction.

Aged↗
PubMed1986

[SPECT images using a multislice fan beam collimator].

Several methods to improve the image resolution of single photon emission computed tomography (SPECT) occur to us. It is one method to use multislice fan beam collimators which have the parallel collimation along the cephalic-caudul axis of a patient and the conversing collimation within planes parpendicular to that axis. It is impossible to obtain corrective image when we used the algorithm which is commonly used for reconstruction of SPECT images. We proposed a reconstruction algorithm for multislice fan beam collimator in this paper. An interpolation method developed for fan beam type X-ray CT was modified to reconstruct images from SPECT with multislice fan beam collimator. This algorithm was confirmed by means of computer simulation studies. Beside improving the system resolution by effectively reducing the intrinsic resolution of the cameras, this collimator also increases the system sensitivity by utilizing a large fraction of the crystal area. We have thought that to use multislice fan beam collimator is beneficial for SPECT images.

Tomography, Emission-Computed↗
PubMed1985

Reversibility of granulocyte adhesion using polyamine-grafted nylon-6 as a new column substrate for granulocyte separation.

Reversibility of leucocytes adhered onto the surface of polyamine-grafted nylon-6 was investigated to estimate its feasibility as a new column substrate for granulocyte separation from whole blood. Polyamine-grafted nylon-6 was synthesized by a radical polymerization of 2-diethylaminoethyl methacrylate monomer onto nylon-6. The surfaces of these graft copolymers were found to show a microphase-separated structure composed of island-like phases of cationic polyamine and continuous phases of nonionic nylon-6. Interaction between leucocytes and these copolymer surfaces was studied by passing rabbit heparinized blood through a column packed with glass beads precoated with these copolymers. Columns of these copolymers showed a selective adhesion of granulocytes among leucocyte populations. Also, the adhering granulocytes were able to be recovered from the column by a gentle elution procedure. From these results, it was concluded that polyamine-grafted nylon-6 having a microphase-separated structure is suitable for use as a column substrate in granulocyte separation from whole blood.

Animals↗
PubMed1985

[Radiotherapy (interstitial irradiation) of carcinoma of the tongue--an analysis of cases in the past 10 years].

A total of 82 histologically proven squamous cell carcinomas of the tongue, which were treated by interstitial irradiation (radium) at Chiba Cancer Center from 1973-1982, were reviewed. The cumulative five-year survival rate of all cases was 64%: 78% in Stage I and II group, 68% in Stage III and 47% in Stage IV. Local recurrence was noted in eight cases (10%) and later cervical node metastases in 14 cases 25% in T 1-4 N 0). The incidence of mandibular osteoradionecrosis was 18 cases (22%).

Adult↗
PubMed1984

[Prospective study to assess the clinical efficacy of bone scintigraphy--methodology and some preliminary results].

The purpose of this study is to evaluate prospectively the value of radionuclide bone scans at the preoperative assessment of carcinomas of the breast and prostate carcinomas. Ten hospitals which are in or near Tokyo are participating in this study. For each patient under study, three kinds of sheet are filled by doctors. The first sheet named "preexamination diagnosis data sheet" is recorded before preoperative bone scan by attending physicians mainly. The second sheet named "postexamination diagnosis data sheet" is recorded after preoperative bone scan by nuclear medicine physicians who performed bone scintigraphy. The third sheet named "final diagnosis data sheet" is recorded after about a year of follow up period by attending physicians or nuclear medicine physicians. These data have been stored in a electric computer. Some preliminary analysis has been made by comparing the confidence level of diagnosis for bone metastasis before and after bone scintigraphy. In this report, methodology of the analysis and some results are described.

Adult↗