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Biomedical subjects

S Hara

Publications and source records attributed to S Hara.

At least 451 records · Page 25Linked to original sources
PubMed1989

Synthesis of imidazo[4,5-d][1,3]thiazine ribosides and related compounds of biological interest.

Several tri-O -acetyl-1-beta-D -ribofuranosyl- and 2-acetoxyethoxymethylimidazo[4,5-d][1,3]thiazine derivatives 5-10 were synthesized from imidazo[4,5-d][1,3]thiazine 4 and tetra-O -acetyl-beta-D -ribofuranose or 2-acetoxyethoxymethyl acetate by fusion method. In each case, depending on the substituent on position 5 of thiazine skeleton, only N3 isomer or both N1 and N3 isomers (in different ratios) were obtained.

Acyclovir↗
PubMed1989

Possible catabolism of paraquat in mouse brain microsomes.

Whether formalin would be formed from paraquat (PQ) was studied in vitro using subcellular fractions of the mouse tissues. When Nash's method was used, a detectable increase of the OD at 412 nm was obtained only in the brain microsomal fraction in the presence of NADPH. The OD was increased by the addition of 0.1 mM EDTA. It disappeared when NADPH was omitted or when microsomes were denatured. However, when the brain microsomes were incubated with [3H]PQ in the presence of NADPH and EDTA, no [3H] formalin was detected. These results suggest that PQ may be catabolized in the mouse brain microsomes, though not demethylated, resulting in the production of the Nash reagent-reactive substance.

1-Methyl-4-phenylpyridinium↗
PubMed1989

[Treated case of aortic valve regurgitation associated with Behçet's disease].

Aortic valve replacement was performed to the incompetence of valve cusps with the Behçet's disease. Artificial valve was fixed from the outside of the aortic wall using teflon strips. Satisfactory results were obtained. There are 18 cases of aortic valve regurgitation accompanied with Behçet's disease including this reported case. Not only the aortic valve but also surrounding aortic walls are involved by the inflammatory lesion in Behçet's disease, so that such fixation technique of the prosthetic valve as demonstrated above might be useful. Since Behçet's disease is systemic, progressive and chronic disease, anti-inflammatory treatment with the adrenal steroids is required prior to and after the operation, and there is no distinct method of treatment for Behçet's disease, strict observation of the patient and systemic controls should be recommended continuously.

Aortic Valve↗
PubMed1989

[Dopamine infusion test as a gastric secretion test].

The secretion of gastric acid in the peptic ulcer patients were examined by the dopamine infusion test (DIT). Production of gastric acid was investigated when the patients were treated by 30-minute dopamine infusion of 2 micrograms/kg/min. According to the difference of production of gastric acid, 132 patients were categorized into three groups: 59 Cata-responders, 28 Ana-responders and 45 Non-responders. Cata-responders were the patients whose production was less than 0.2mEq/30 min, Ana-responders, greater than 0.2mEq/30 min and Non-responder less than or equal to 0.2mEq/30 min. Cata- and Ana-responders showed higher gastric acid secretion preoperatively, and higher gastric acid reduction rate after selective proximal vagotomy (SPV) than Non-responder. Cata-responder showed decreased acid output preoperatively and unchanged after SPV with DIT. Ana-responder showed increased acid output preoperatively and decreased after SPV with DIT. Non-responder showed unchanged acid output preoperatively and decreased after SPV. Cata-responder may be depending more on vagus-mediated factor and parietal cell mass. Ana-responder may be depending more on vagus-mediated factor, parietal cell mass and dopaminergic factor. Non-responder may be depending more on gastrin cell mass and less cholinergic influence. From these findings dopamine receptor may exist in the stomach, and DIT seems to be useful in studying pathogenesis of the peptic ulcer and determining treatment for patients with peptic ulcer.

Adolescent↗
PubMed1989

[Clinical study of aminoglycosides on renal dysfunction--pharmacokinetics of arbekacin and its elimination effects by hemodialysis and adsorption with charcoal].

In vitro studies of elimination of arbekacin (HBK), a new aminoglycoside antibiotic, from blood by means of hemodialysis or adsorption with charcoal, and pharmacokinetic studies in patients with renal dysfunction were examined. HBK was well eliminated by hollow fiber type artificial kidney (HFAK) with a half-life of 0.13 hr. HBK was also well eliminated by an adsorption tube containing charcoal with even shorter half-life of 0.03 hr. As to pharmacokinetics of HBK in patients with renal dysfunction, blood levels became higher with a greater reduction in 24 hr endogenous creatinine clearance (Ccr). A decreasing tendency was also seen in urinary recovery rate. These results indicated that hemodialysis and adsorption with charcoal are useful for elimination of HBK from blood. It is recommendable in patients with renal dysfunction to take some measures such as prolongation of administration interval of HBK according to the extent of decrease in Ccr.

Adsorption↗
PubMed1989

Use of a convex mirror in indirect ophthalmoscopy for patients in a prone position.

Fundus examination with the patient in a prone position sometimes requires the observer to assume an uncomfortable position. I describe using a convex rear-view mirror with an 800-mm radius of curvature in binocular indirect ophthalmoscopy to overcome this difficulty. This device is especially helpful in pneumatic retinopexy.

Fundus Oculi↗
PubMed1989

Solitary retroperitoneal neurofibroma: a case report.

A solitary neurofibroma arising in the retroperitoneal space without any other stagma of von Recklinghausen's disease is reported. Confusion with another nerve sheath tumor, a schwannoma is a diagnostic pitfall. Histochemical and immunohistochemical stainings of the tumor are useful for the diagnosis of solitary neurofibroma.

Female↗
PubMed1989

[Adrenomedullary epinephrine excretion and myocardial norepinephrine release during cardiopulmonary bypass].

It has long been known that shock or surgical stress promotes an epinephrine (E) excretion from the adrenomedullary glands. In fourteen adult cardiac patients, plasma E values in both superior vena cava (SVC) cannula and inferior vena cava (IVC) cannula during total cardiopulmonary bypass (CPB) are studied at three stages, before aortic cross clamp (pre AXC), after release of aortic cross clamp (post AXC) and at 34 degrees C rectal temperature in rewarming (34 degrees C RT). Although E values in both SVC and IVC are slightly higher values than normal in pre AXC, they increase sharply to peaked values at post AXC and decline uniformly close to normal at 34 degrees C RT. IVC-E is constantly significantly higher (statistically) than SVC-E at each of all three stages. It is strongly suggested that E response to CPB is mainly originated from the adrenomedullary glands, and cardiac reflex which has sympathetic efferent limbs triggered by myocardial ischemia can indicate the increase in E during AXC. Myocardial norepinephrine (NE) release in heart ischemia such as acute myocardial infarction has been generally accepted. To examine whether myocardial NE release occurs during AXC, if there is the association of NE release with any clinical parameters, the second investigation is done in twenty-six adult cardiac patients. Plasma NE values in both the radial artery (A) and the coronary sinus (CS) are measured at six stages, pre AXC (stage 1), post AXC (stage 2), post CPB (stage 3), three hours after off CPB (stage 4), six hours off CPB (stage 5) and twelve hours off CPB (stage 6).(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Medulla↗
PubMed1989

[Changes of protein and RNA content in accumulated G1 cells by delta12-PGJ2].

Protein and RNA content in accumulated G1 cells was measured with B16 melanoma cells by flow cytometer to study the mechanism of antineoplastic action of delta 12PGJ2. DNA histogram showed that, after a 6 hr exposure to delta 12PGJ2, the percentage of tumor cells in G2M phase increased, and G1 accumulation with depletion of cell population in S phase was seen after 12-24 hr exposure to 2.0 micrograms/ml of delta 12 PGJ2. Protein content in accumulated G1 cells increased at 6 hr after exposure, and subsequently decreased. However, the protein content treated with delta 12PGJ2 was higher than that of the control. A reduction of RNA content in G1 cells was seen after delta 12PGJ2 exposure. As the result, it was found that delta 12PGJ2 made cell progression ceased in G1 phase of cell cycle, and where protein and RNA content was higher than that of control. It is suggested that some hyper-metabolite state was caused by delta 12 PGJ2 in cultured B16 melanoma cells.

Antineoplastic Agents↗
PubMed1989

[A case of concomitant association of discrete subaortic stenosis in Kelly type I and hypertrophic cardiomyopathy in early stage].

A 1-year-old baby boy with discrete subaortic stenosis in Kelly type I had coexisting echocardiographic evidence for probably indicating the presence of hypertrophic cardiomyopathy in early stage. At surgery, a discrete subaortic "fibrous membrane" was excised: although the thickening of upper ventricular septum was not thought to be so prominent, the prognosis is related to the natural history of hypertrophied muscle despite successful surgical removal of the subaortic diaphragm.

Aortic Stenosis, Subvalvular↗
PubMed1988

Characterization of [3H]U46619 binding in pig aorta smooth muscle membranes.

The binding characteristics of [3H]U46619, a tritiated thromboxane A2/prostaglandin H2 mimetic, were studied in pig aorta smooth muscle membranes. Binding was fast, saturable, selective and reversible. The KD values determined by kinetics, equilibrium binding and drug competition methods were 68, 42 and 53 nM, respectively. The Bmax was 87.8 fmol/mg protein. Specific binding was competitively displaced by thromboxane A2/prostaglandin H2 antagonists. Binding was also displaced by prostaglandins D2, E2 and F2 alpha with IC50 values of 8, 21 and 12 microM, respectively. U46619 contracted the rat and pig aorta smooth muscle, but the response of the latter was slower than that of the former. The antagonists prevented the U46619-induced contraction of rat aorta with the same rank order as that for the inhibition of ligand binding in pig aorta smooth muscle membranes. These results provide evidence that the putative thromboxane A2/prostaglandin H2 receptor in vascular smooth muscle membranes can be detected by a ligand binding technique.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1988

Two-dimensional high-performance liquid chromatographic system for the direct determination of tocopherol derivatives in plasma.

A procedure for the quantitative extraction of tocopherol derivatives from plasma was systematically developed using an efficient liquid-liquid distribution process. An aqueous stationary phase was coated on silica gel or diatomaceous earth powder in a closed-bed glass column prepared by slurry packing. A liquid-liquid chromatographic system provided with a detector was introduced as a preliminary extraction process. Liquid-solid chromatography followed as the second dimension of the separation and was used to determine alpha-tocopherol nicotinate in the extract. Stationary and mobile phases in the two-dimensional liquid chromatographic system were optimized to determine tocopherol derivatives. A highly sensitive quantitation method for alpha-tocopherol nicotinate in plasma was developed by using liquid-liquid and liquid-solid chromatography in conjunction with column switching by a tube-type micro-evaporator.

Animals↗