PubMed Health⌕ Search

Biomedical subjects

H Fukaya

Publications and source records attributed to H Fukaya.

At least 19 recordsLinked to original sources
PubMed1995

Photochemistry of acetylenic ketones in micellar solutions as studied by product-yield-detected ESR and transient absorption techniques.

The electron spin resonance (ESR) spectra of the transient radical pairs in the photoreduction of 1,5-diphenyl-1,4-pentadiyn-3-one(I) and 1,3-diphenyl-2-propyn-1-one(II) in sodium dodecyl sulfate (SDS) micellar solutions have been obtained by using the product-yield-detected ESR (PYESR) technique. The PYESR spectra, detected by tracing the microwave effect on the spin-adduct yield as functions of the magnetic field, show the ESR spectra of the ketyl radical of the ketone and SDS radical as the components of the radical pairs. In addition, the growth and the decay processes of the radical pair were observed through detecting the effect of microwave pulse as functions of the delay period between a laser pulse and the off and on time, respectively, of a microwave pulse. The absorption spectra of transient species have also been obtained by using the laser flash photolysis technique. Through the analysis of these data and molecular orbital calculations, the role of acetylenic groups in the photoreactivity of acetylenic ketones is discussed.

Alkynes↗
PubMed1990

[Intravenous DSA as a screening method for cerebral aneurysms].

Intravenous DSA (IVDSA) was evaluated as a screening method for cerebral aneurysms. It was performed 390 times in 372 cases. Clinically useful images were obtained in 94.1% in all examinations. Nineteen aneurysms were visualized in cerebral angiography among 21 cases with SAH or 3rd nerve palsy, whereas in IVDSA 15 aneurysms were noted. Aneurysms not visualized in IVDSA were all 4 mm or less in size. Therefore, aneurysms, more than 4 mm in size, which have higher risks for rupture, were detectable in IVDSA. Based on these findings, IVDSA is considered to be clinically useful in screening for aneurysms. In all 372 cases, 33 aneurysms were suspected in IVDSA findings, whereas in cerebral angiography 21 of them turned to be aneurysms. Such 12 false positive cases were distributed mainly at anterior communicating and middle cerebral arteries. Improvement of image resolution, avoidance of vessel overlapping and proper selection of screened cases should be investigated for further development of this screening method.

Angiography, Digital Subtraction↗
PubMed1988

Effect of blood purification on the kidney function of the jaundiced rat.

This paper is aimed at evaluating the effect of blood purification on the mitochondrial functions of the kidney in jaundiced rats. At 1, 2, or 3 weeks after bile duct ligation and dissection, obstructive jaundiced rats were utilized for experiment. Cross circulation in 1 ml/min between jaundiced rats and normal rats was performed for 1 or 3 h. Immediately and 24 h after cross circulation, the rats were killed and mitochondrial respiratory functions of the kidney were assessed by measuring oxygen consumption. Mitochondrial function, especially ATP synthesis, showed significant improvement in jaundiced rat with 2 or 3 weeks of biliary obstruction. Cross circulation for 3 h was more effective than that for 1 h. These data suggest that the renal energy production can be increased significantly in obstructive jaundice by blood purification treatment.

Animals↗
PubMed1987

Development of tolerance and supersensitivity to phencyclidine in rats after repeated administration of phencyclidine.

In rats treated with phencyclidine (PCP) repeatedly (PCP 10 mg/kg per day for 14 days), the back-pedalling, head-weaving and turning induced by PCP were attenuated (tolerance), while PCP-induced sniffing, rearing and ambulation were potentiated (supersensitivity). The behavior induced by the direct and indirect serotonin (5-HT) agonists, 5-methoxy-N,N-dimethyltryptamine and p-chloroamphetamine, was attenuated, while the sniffing, rearing or licking induced by the direct and indirect dopamine (DA) agonists, apomorphine and methamphetamine, were potentiated in the chronic PCP-treated rats. The DA and 5-HT contents in the nucleus accumbens and the ratio of HVA to DA in the striatum increased following the repeated PCP administration. Pentobarbital-induced sleep time did not change in the chronic PCP-treated rats as compared with the control rats. In addition, there was no significant difference between the disappearance rate of PCP in the brain of the rats treated with PCP repeatedly and the rate in the control rats. These results suggest that functional changes in the dopaminergic and serotonergic neuronal systems develop on repeated administration of PCP but that such changes do not develop in the hepatic drug-metabolizing system. In addition, tolerance develops in the serotonergic neuronal system while supersensitivity develops in the dopaminergic neuronal system. Biochemical findings suggest that increased mesolimbic dopaminergic neuronal function plays an important role in the development of the supersensitivity.

Animals↗
PubMed1986

Potentiation of phencyclidine-induced stereotyped behaviors in rats by thiorphan and bestatin.

We investigated the effects of thiorphan, a specific inhibitor of enkephalinase A and bestatin, a specific inhibitor of aminopeptidase, on the stereotyped behaviors induced by phencyclidine (PCP) in cannulated rats. The PCP-induced turning was significantly potentiated when thiorphan (50 micrograms) and bestatin (50 micrograms) were injected simultaneously into the rat lateral ventricle. The increase of PCP-induced turning was completely antagonized by the pretreatment with naloxone. Thiorphan (50 micrograms) or bestatin (50 micrograms) alone failed to potentiate PCP-induced turning. Thiorphan and/or bestatin did not affect significantly the PCP-induced head weaving and back-pedalling except that thiorphan (50 micrograms) potentiated the PCP-induced head weaving 15-18 min after the PCP injection. The combination of thiorphan and bestatin alone did not induce any behavioral change. These results suggest that thiorphan and bestatin produce an increase of endogenous enkephalins and that as a result, PCP-induced turning may be enhanced.

Amino Acids, Sulfur↗
PubMed1985

[Significance of cross-circulation on obstructive jaundice in rats with special reference to the mitochondrial function of the liver and kidney].

Cross-circulation was performed to investigate the mitochondrial respiratory function of the liver and kidney in rats after 1, 2 and 3 weeks of biliary obstruction. Serum bilirubin and total bile acids concentration in blood in rats with biliary obstruction markedly decreased with 3 hours cross-circulation. There demonstrated, however, no significant change in mitochondrial function in the liver after cross-circulation. In contrast, mitochondrial function in the kidney showed significant improvement after 3 hours cross-circulation. Mitochondrial respiratory function in normal partner rats cross-circulation with jaundiced rats demonstrated temporal deterioration in the kidney and prolonged deterioration in the liver. It can be concluded that cross-circulation or plasma exchange might be useful for the prevention of renal failure in obstructive jaundice, since cross-circulation induced persistent improvement of the mitochondrial respiratory function in the kidney deteriorated by biliary obstruction.

Animals↗
PubMed1983

Human ACTH, beta-lipotropin and beta-endorphin levels in maternal plasma at delivery.

Adrenocorticotropic hormone (ACTH), beta-lipotropin (beta-LPH) and beta-endorphin (beta-EP) were measured simultaneously in maternal plasma at delivery. Mean concentrations of beta-LPH and beta-EP in maternal plasma at delivery were significantly higher than those in normal control. There were significant positive correlations among ACTH, beta-LPH and beta-EP concentrations, respectively. These data suggest that beta-LPH and beta-EP were elevated during delivery and in parallel with each other.

Adrenocorticotropic Hormone↗
PubMed1981

Experimental and clinical studies on renal disturbance in obstructive jaundice.

Renal functions and the clinical courses of 14 patients with renal disturbances associated with obstructive jaundice were studied. All patients had high concentrations of serum bilirubin, long durations of jaundice and episodes of shock due to massive hemorrhage or severe inflammation. In an experimental study on jaundiced rats, effects of hypotension or bilateral renal artery occlusion on renal function and renal cortical mitochondrial respiration at 1 week, 3 or 6-weeks after biliary obstruction were investigated. In jaundiced rats, there was no remarkable difference in renal function, but the renal mitochondrial respiration indices decreased with prolongation of the biliary obstruction. In hypotensive rats with prolonged biliary obstruction, the mitochondrial function was impaired, and in the rats with renal artery occlusion, the mitochondrial impairment was more severe. Based on these clinical and experimental data, it is tentatively suggested that patients with prolonged jaundice should be considered in a prodromal state of renal failure and that any minute circulatory failure may induce acute renal failure.

Acute Kidney Injury↗
PubMed1969

Simple uniaxial and uniform biaxial deformation of nearly isotropic incompressible tissues.

A method is developed for analyzing in a unified manner both uniaxial and uniform biaxial strain data obtained from nearly isotropic tissues. The formulation is a direct application of nonlinear elasticity theory pertaining to large deformations. The general relation between Eulerian stress (sigma) and extension ratio (lambda) in soft isotropic elastic bodies undergoing uniform deformation takes the simple form: sigma = ((lambda(3) - 1)/lambda) f(lambda), where f(lambda) must be determined for each material. The extension ratio may be either greater than 1.0 (uniaxial elongation), or lie between zero and 1.0 (uniform biaxial extension). Simple analytical functions for f(lambda) are most readily found for each tissue by plotting all data as (lambda(3) - 1)/lambdasigma vs. lambda. Of those tissues investigated in this way (dog pericardium and pleura, and cat mesentery and dura), all but pleura could be adequately described by a parabola: 1/f(lambda) = 1/k{[(lambda(M) - lambda)(lambda - lambda(m))]/[lambda(M) - lambda(m)}. In these instances, three material constants per tissue (K, lambda(M), lambda(m)) served to predict approximately the stresses attained during both small and large deformations, in strips and sheets alike. It was further found that the uniaxial strain asymptote (lambda(M)) was linearly related to the biaxial strain asymptote (Lambda(M)), thus effectively reducing the number of constants by one.

Animals↗