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Biomedical subjects

Y Tamura

Publications and source records attributed to Y Tamura.

At least 667 records · Page 37Linked to original sources
PubMed1983

Pharmacokinetics of prifinium bromide in healthy volunteers.

The pharmacokinetics of prifinium bromide (Riabal), a specific antispasmodic agent, after oral (60 mg) and i.v. (7.5 mg) administration was studied in six healthy male volunteers. After i.v. administration, the drug was rapidly cleared from the serum. Individual serum levels were described by a bi-exponential equation and mean elimination half-life was 2.13 h. The volume of distribution at steady state was about 190% of body weight, and the total serum clearance and renal clearance were 12.5 and 5.80 ml/(min. kg), respectively. The drug reached maximum serum levels (6.76-14.3 ng/ml) within 2-3 h after administration of tablets: the apparent biologic half-life after oral dosing was 2.18 h. The oral bioavailability was low (3.4%), as expected for quaternary ammonium compounds, but the inter-individual variation of bioavailability was small.

Adult↗
PubMed1982

The effects of the oral administration of fish oil concentrate on the release and the metabolism of [14C]arachidonic acid and [14C]eicosapentaenoic acid by human platelets.

It has been suggested by several investigators that eicosapentaenoic acid (C20:5 omega 3, EPA) might have anti-thrombotic effects. In this experiment, the effect of the oral administration of EPA rich fish oil concentrate on platelet aggregation and the release and the metabolism of [1-14C]arachidonic acid and [(U)-14C]eicosapentaenoic acid by human platelets was studied. Eight healthy male subjects ingested 18 capsules of fish oil concentrate (EPA 1.4 g) per day for 4 weeks. Plasma and platelet concentrations of EPA markedly increased, while those of arachidonic acid (C20:4 omega 6, AA) and docosahexaenoic acid (C22:6 omega 3, DHA) did not change. Platelet aggregation induced by collagen and ADP was reduced. Collagen induced [14C]thromboxane B2 (TXB2) formation from [14C]AA prelabeled platelets decreased. There was no detectable formation of [14C]TXB3 from [14C]EPA prelabeled platelets, and the conversion of exogenous [14C]EPA to [14C]TXB3 was lower than that of [14C]AA to [14C]TXB2. The release of [14C]AA from [14C]AA prelabeled platelets by collagen was significantly decreased. These observations raise the possibility that the release of arachidonic acid from platelet lipids might be affected by the alteration of EPA content in platelets.

Adenosine Diphosphate↗
PubMed1982

[Diagnostic criteria for pseudohypoparathyroidism and related diseases].

In order to make a statistical survey of Japanese patients with pseudohypoparathyroidism and related diseases, we defined the diagnostic criteria for seven disease states described below. The criteria were mainly based on practical data readily available at standard hospitals. In the text, the seven diseases are described separately in the order of a) definition or conception, b) pathophysiology, c) proposed diagnostic criteria, d) comments on the diagnostic criteria. The diseases are (1) Pseudohypoparathyroidism Type I, (2) Pseudohypoparathyroidism Type II, (3) Pseudohypo-hyperparathyroidism, (4) Pseudopseudohypoparathyroidism, (5) Pseudoidiopathic hypoparathyroidism, (6) Vitamin D dependency type I and (7) Hypophosphatemic vitamin D resistant rickets. Based on these diagnostic criteria, a nation-wide investigation on patients with these diseases was performed (The detailed report will appear in a separate paper). The results indicated that these criteria are of considerable value in establishing diagnoses from questionnaires answered by practicing physicians.

Calcium↗
PubMed1982

High-performance liquid chromatographic determination of prifinium quaternary ammonium ion in human serum and urine.

A simple, sensitive method for the determination of the prifinium ion, a quaternary ammonium ion, in human serum and urine is described. The method is based on extraction of the test solution with chloroform in the presence of saturated potassium bromide solution and normal-phase high-performance liquid chromatography using aqueous methanol as the mobile phase at pH 10. To prevent the dissolution of silica from the analytical column, the mobile phase is pre-saturated with silica by using a silica saturation column. Quantitation is possible down to 0.5 ng/ml of prifinium ion using 2 ml of serum and down to 5 ng/ml using a 1 ml of urine. The coefficients of variation of the method are less than 1.3% in both serum and urine. Serum levels and urinary excretion data obtained with this method are given for three healthy volunteers who had received a 60-mg oral dose of prifinium bromide.

Chromatography, High Pressure Liquid↗
PubMed1982

Effects of orally administered ethyl ester of eicosapentaenoic acid (EPA; C20:5, omega-3) on PGI2-like substance production by rat aorta.

A highly purified ethyl ester of EPA (EPAEE) (74%) was manufactured from sardine oil. Sixty mg/kg/day of EPAEE was given orally to male Wistar rats for 8 weeks. No side effect or toxicity from the administration of EPAEE was observed. Plasma EPA concentration and the ratio of EPA to arachidonic acid were significantly increased, compared with control Wistar rats. An enhancement of PGI2-like substance production by aortas obtained from rats fed EPAEE was noted. Conversion of EPA to delta 17-6-keto-PGF1 alpha, a stable metabolite of PGI3, could not be detected by an incubation study of 14C-EPA and aortas either from rats fed EPAEE or from control rats. Therefore, PGI2-like substance produced by rat aorta is most likely to be PGI2 itself and not PGI3.

6-Ketoprostaglandin F1 alpha↗
PubMed1982

Comparison of superprecipitation and contractile protein contents of myosin B in the myocardium and conduction system.

The extents of superprecipitation and contractile protein contents of myosin B in the myocardium and conduction system were compared. The extents of superprecipitation of myosin B of the two types of cardiac muscle were similar, but the onset of the superprecipitation reaction of myosin B from the conduction system was delayed and the clearing phase of the reaction was prolonged. On sodium dodecyl sulfate (SDS)-polyacrylamide gel (6%) electrophoresis of myosin B, myosin, actin, and tropomyosin were clearly separated. The amounts of protein present in stained bands of polyacrylamide gels were estimated. The weight ratios of myosin: actin, tropomyosin: myosin, and actin: tropomyosin in myosin B were not significantly different in the two types of cardiac muscle. However, the compositions of myosin light chains in the two types of cardiac muscle were quite different. It was suggested that this difference of myosin subunits might contribute to the difference in superprecipitation of myosin B.

Actins↗