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Biomedical subjects

T Shinzato

Publications and source records attributed to T Shinzato.

At least 109 records · Page 6Linked to original sources
PubMed1991

Comparison of the acute hemodynamic and coronary vasodilating effects between nicorandil and glyceryl trinitrate.

Acute hemodynamic and coronary vasodilating effects of nicorandol (SG-75, Sigmat; CAS 65141-46-0) and glyceryl trinitrate (GTN, nitroglycerin) were examined in 20 subjects under cardiac catheterization and coronary arteriography. Nicorandil 4 mg i.v. produced significant increases in heart rate, cardiac index and stroke volume index and significant decreases in systolic, diastolic and mean blood pressure, pulmonary capillary wedge pressure, left ventricular enddiastolic pressure, systemic vascular resistance and total pulmonary resistance. Degree of percent changes in these parameters by nicorandil were similar to that by GTN 0.3 mg i.v. Coronary vasodilating effects of both drugs were also at the same degree. Results indicate that nicorandil has cardiovascular and coronary vasodilating effects similar to those of GTN when administered intravenously.

Adult↗
PubMed1990

Effectiveness of push/pull hemodiafiltration using large-pore membrane for shoulder joint pain in long-term dialysis patients.

Long-term hemodialysis (HD) patients complaining of shoulder joint pain were treated by HD and by push/pull HDF using high-flux synthetic membranes with large pores (Asahi PAN 20CX2) for 2 weeks. The results showed no significant difference in Kt/Vurea between HD and push/pull HDF. Nevertheless, reduction of the plasma beta 2-microglobulin was greater during push/pull HDF than during HD. These findings can be explained by far more convective flux in push/pull HDF than in HD: nearly 30 L during push/pull HDF vs. 3 L during HD. In the present study, there was no alleviation of the shoulder joint pain during HD treatment, whereas marked relief of the symptom was found during push/pull HDF treatment. Since the two treatment modalities differ simply in their efficiency in removing larger molecular weight substances, the joint pain alleviation effected by push/pull HDF could well be ascribed to elimination of an unknown larger molecular weight substance causing this symptom. However, a considerable amount of beta 2-microglobulin was removed both by HD and push/pull HDF. Therefore, the substance causing the joint pain might be larger than beta 2-microglobulin.

Female↗
PubMed1990

Beta-2-microglobulin generation rate and clearance rate in maintenance hemodialysis patients.

We analyzed the rebound pattern of plasma beta 2-microglobulin (beta 2-m) concentration from 4 h after completion of hemodiafiltration until the start of the next treatment according to the one-pool beta 2-m kinetic model so as to determine beta 2-m generation rate and whole-body beta 2-m clearance. Next, we obtained the whole renal beta 2-m clearance as the product of renal creatinine clearance and the glomerular sieving coefficient of beta 2-m. Then, extrarenal beta 2-m clearance was calculated as the difference between whole-body beta 2-m clearance and whole renal beta 2-m clearance and renal beta 2-m clearance due to tubular absorption was taken to be the difference between whole renal beta 2-m clearance and renal beta 2-m clearance due to urinary excretion. The results showed that the higher the patients' plasma beta 2-m concentration was, the lower was the whole-body beta 2-m clearance. Moreover, in the present study, an inverse correlation was found between the following respective factors: plasma beta 2-m concentration and whole renal beta 2-m clearance; plasma concentration and renal clearance due to tubular absorption; plasma concentration and renal clearance due to urinary excretion. However, there was no correlation between plasma beta 2-m concentration and extrarenal beta 2-m clearance. The findings indicate that the variation of plasma beta 2-m concentration with the individual patient is solely attributable to the variation in residual renal function in terms of beta 2-m elimination.

Adult↗
PubMed1989

Comparison of various treatment modes in terms of beta 2-microglobulin removal: hemodialysis, hemofiltration, and push/pull HDF.

The beta 2-microglobulin clearance increased as the convective transport was added during hemodialysis to perform hemodiafiltration (HDF), suggesting that a convective transport type artificial kidney is more effective for beta 2-microglobulin removal. Actually, the decrease in the plasma beta 2-microglobulin level per treatment was more pronounced in hemofiltration and push/pull HDF than in hemodialysis. In the present study, no significant fluctuation in the pretreatment level of beta 2-microglobulin was shown by serial treatment by hemodialysis, whereas an obvious decreasing trend of it was indicated in serial treatment of either push/pull HDF or hemofiltration. Moreover, our study indicated that the ratio of posttreatment beta 2-microglobulin level in relation to its pretreatment level increases as the treatment by hemofiltration or push/pull HDF is repeated.

Amyloid↗
PubMed1989

Effects of L-carnitine administration on short-chain fatty acid (acetic acid) and long-chain fatty acid metabolism during hemodialysis.

The purpose of the study is to investigate the effects of L-carnitine on the exogenous acetate metabolism during hemodialysis together with the triglyceride and free fatty acid metabolism. Sixteen chronic renal failure patients on acetate dialysis were orally administered 1,200 mg of L-carnitine chloride per day for 12 weeks. Plasma triglyceride concentrations at 30 and 60 min following initiation of hemodialysis were significantly lower than before hemodialysis, while the plasma concentrations of free fatty acid at the same points into hemodialysis were significantly higher than before hemodialysis, whether L-carnitine chloride was being given or not. This is attributed to the enhanced degradation of triglyceride and the increased generation of the free fatty acid with heparin administration during hemodialysis. The L-carnitine chloride treatment did not affect the plasma triglyceride concentrations at 30 and 60 min into hemodialysis, whereas the free fatty acid concentrations at the same points into hemodialysis were significantly lower after L-carnitine chloride administration commenced than before it. This is attributed to the fact that fatty acid oxidation was enhanced following the L-carnitine chloride treatment. Compared to before the drug administration, the whole body clearance of exogenous acetate was significantly increased after the drug was given, and the plasma acetate level during hemodialysis fell accordingly. This is attributed to the fact that with L-carnitine chloride administration, the amount of accumulated acyl-CoA in the cytosol decreased and consequently the citrate cycle function increased.

Acetates↗
PubMed1988

Role of hypovolemia in dialysis-induced hypotension.

Blood volume was measured continuously during hemodialysis using the authors' hematocrit continuous measurement system in an attempt to determine any relationship between dialysis-induced hypotension with acute onset and blood volume. Hypotension resulted approximately 3 h into dialysis in the present study. This point in time was that at which blood volume was more than 5% above the minimum level during the dialysis treatment, and in some patients it was more than 10% over the minimum level of blood volume. At the time dialysis-induced hypotension occurred or before, there was no sharp decrease in blood volume nor any change in the plasma refilling rate. This suggested that this hypotension is caused by a sudden breakdown of the blood pressure support mechanism compensating for decreased blood volume.

Blood Volume↗
PubMed1986

Newly developed circulating blood volume-monitoring system and its clinical application for measuring changes in blood volume during hemofiltration.

Blood and ultrafiltrate electrical resistivities were continuously monitored during hemofiltration. By substituting these values into a previously developed equation that was modified by the authors, the hematocrit value was determined; and blood volume change was obtained from the change in this value. The following facts were discovered as the result of monitoring the blood volume change during treatment: When the body position was changed from the reclining to the sitting position, the blood volume decreased by 4.2 +/- 0.3%. With the body water removal rate kept constant, the body position recumbent, and the subject fasted, the blood volume gradually decreased. However, when the position was changed from reclining to sitting for food intake and once more returned to the supine position after the meal, the blood volume was greatly affected by the change in position and the food intake.

Blood↗
PubMed1986

Removal of denatured proteins with artificial reticulo-endothelial system (ARES).

Basic research has revealed that hydrophobic residues increased on the molecular surface of the denatured IgG and that the denatured proteins in the plasma can be removed by several sorbents of different amino acids bonded from polyvinylalcohol hydroxide residue with a covalent bond. Thus, an artificial reticulo-endothelial system was developed to supplement the human reticulo-endothelial system (RES) by removing denatured proteins from the patient's plasma. Clinically, angiitis and Raynaud's phenomenon associated with collagen disease such as systemic lupus erythematosus were remarkably reduced following a series of ARES treatments. The proteins adsorbed on the ARES were analyzed by two-dimensional electrophoresis. Virtually no albumin was detected, and IgG (constant isoelectric point), IgM, IgA, IgA dimer, C3, C4, fibrinogen and other unidentified spots were found in the elute from the ARES column.

Adsorption↗
PubMed1983

Plasma exchange for treatment of intractable psoriasis.

Hemofiltration and plasma exchange, using a plasma separator with membranes, were used in 14 psoriatic patients. The efficacies of the treatments were compared. Among the patients, 13 were treated with hemofiltration and/or direct hemoperfusion, 5 experienced complete remission, 5 improved, and 3 remained unaffected. In these 3 cases, plasma exchange was performed. The first patient, who suffered from psoriasis pustulosa with arthropathica, achieved complete remission with only two treatment of 2-L plasma exchange. Joint pain was also eliminated. Both skin lesions and joint pain were markedly improved in the second patient, who suffered from psoriasis vulgaris with arthropathica. The third patient showed marked improvement with only two plasma exchanges, and is under continuing observation.

Adult↗
PubMed1982

Infusion-free hemodiafiltration: simultaneous hemofiltration and dialysis with no need for infusion fluid.

A new simultaneous hemofiltration and dialysis system was developed which has no need of infusion fluid. The system employs two hemodiafilters in a direct series. An ultrafiltration rate and dialysate flow rate control system was employed to control the dialysate flow at the inlet and outlet, and the difference in volume was arranged to be the amount of water removed from the body. When the blood circuit was narrowed between the two hemodiafilters, the ultrafiltration was performed at the first hemodiafilter; at the second one, the dialysate moved to the blood side as a dilution fluid. To remove pyrogens and bacteria, tap water was subjected to activated charcoal, ion exchange and reverse osmosis treatment, followed by preparation of the dialysate. In clinical evaluation, this system showed marked improvement in clearance of middle and large molecules.

Adult↗
PubMed1980

Effects of ticlopidine on thrombotic obstruction of A-V shunts and on dialysance of artificial kidneys.

Administration of ticlopidine, a new inhibitor of platelet aggregation, during hemodialysis to two patients with thrombotic occlusion of external A-V shunts markedly suppressed the obstruction of the shunt and improved anemia. Consequently, it was concluded that this drug may be useful for maintaining good blood flow and good patency of shunts in patients undergoing dialysis. In order to determine the dialyzer efficiency during dialysis, the reduction rate of the dialyzer was determined in vitro. The dialyzer reduction rates for urea, creatinine, uric acid, and phosphoric acid were all lowered after dialysis, and the administration of ticlopidine resulted in a suppression of the drop in the reduction rate. Based on the inhibitory effect of ticlopidine on platelet aggregation, it was assumed that a close correlation may exist between adhesion and aggregation of platelets and the drop in the efficiency of the dialyzer during dialysis as well as thrombotic obstruction of shunts.

Adult↗
PubMedDate not supplied

Mechanism of dialysis-induced hypotension.

Using a hematocrit monitoring system and a Swan-Ganz catheter, the authors investigated the changes in blood volume and hemodynamic parameters before, during, and after dialysis-induced hypotension. When hypotension occurred, the cardiac output dropped sharply, and there were concomitant sudden decreases in the mean pulmonary arterial pressure and the mean right atrial pressure. These are attributed to a decrease in venous return. Since there was no recognizable change in blood volume when the blood pressure fell sharply, decrease in the venous return is considered to be caused by relocation of circulating blood, possibly associated with a sudden decrease in venous tone.

Hemodynamics↗