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Biomedical subjects

A Hayashi

Publications and source records attributed to A Hayashi.

At least 433 records · Page 24Linked to original sources
PubMed1982

Effects of prostaglandins on thrombus formation in mesenteric arterioles of rats.

Effects of locally applied prostaglandins on platelet thrombus formation in the mesenteric arterioles of rats were studied in vivo. Prostaglandin (PG) I2 and PGE1, which were reported to be powerful inhibitors of blood platelet aggregation, prevented the thrombus formation, whereas PGE2, which was reported, in low concentrations, to enhance platelet aggregation, showed a tendency to promote the thrombus formation. PGA1, PGA2 or PGF2 alpha had no effect. PGD2 had a very weak inhibitory effect. As prostaglandins tested had no effect on the diameter of mesenteric arterioles, it is assumed that the effectiveness of PGI2 and PGE1 in preventing thrombus formation is due mainly to their powerful inhibiting effects on platelet aggregation.

Animals↗
PubMed1982

Temperature dependence if beta-receptor mediated relaxation in rabbit intestine.

The relaxation induced by isoproterenol, A beta-stimulant, appears more markedly at 25 degrees C (pD2 7.98) than at 37 degree C (pD2 6.88) in rabbit intestine. The isoproterenol-induced relaxation was antagonized by treatment with propranolol but not phentolamine at both 25 degree and 37 degrees C, indicating that the relaxation was mediated via adrenergic beta-receptor. The relaxations induced by papaverine, theophylline and MgCl2 were not influenced by temperature change. Basal tissue cyclic AMP content was higher at 25 degrees C than at 37 degrees C, and isoproterenol increased the tissue cyclic AMP content to a similar extent at 25 degrees C and 37 degrees C in the presence of theophylline. The binding of 3H-dihydroalprenolol (3H-DHA) to beta-receptor did not solve the reason of higher sensitivity to isoproterenol at 25 degrees C than at 27 degrees C. At 37 degrees C isoproterenol was more effective in producing a relaxation in the presence than the absence of ascorbic acid (0.057 mM). It is thought that the temperature dependency of the isoproterenol-induced relaxation may be mainly due to the breakdown of isoproterenol in a high temperature.

Animals↗
PubMed1981

Structural analysis of human hemoglobin variants with field desorption mass spectrometry.

Tryptic hydrolyzates of normal and abnormal human globin chains were analyzed with mass spectrometry, using field desorption ionization technique. All the peptides, including core peptides, were detected as protonated molecular ions in field desorption mass spectra. Since the technique makes it possible to determine the mass number of each peptide, it is very useful for structural analysis of human hemoglobin variants, even those with electrophoretically and chromatographically silent mutations.

Adult↗
PubMed1981

Reappraisal of endorectal pull-through procedure. I. Anorectal malformations.

Postoperative continence in anorectalmalformations was assessed by clinical score, rectoanal manometry, and electromyography. The results in low deformities operated by perineal rectoplasty showed "good" clinical scores, good preservation of the rectoanal reflex, and good electrical activity of the external sphincter. High deformities, on the other hand, showed low clinical scores, poor recordings of the rectoanal reflex, and diminished electrical activity around the anus. Analysis of high deformities treated by operative procedures, however, indicated better clinical scores and better preservation of rectoanal reflex in those who had undergone the endorectal pull-through procedure (Rehbein) than those who had had an abdominoperineal pull-through procedure. Furthermore, dissections of newborns with a rectourethral fistula revealed the presence of the puborectalis sling around the terminal rectum and fistula in a hammock fashion. This finding supports our suggestion that the colon can be safely pulled-through within the sling by the original Rehbein procedure without sacral dissection.

Anal Canal↗
PubMed1981

Structural studies on glycolipid of shellfish. III. Novel glycolipids from Turbo cornutus.

Five kinds of sphingoglycolipids were isolated from Turbo cornutus. Four of them were a series of novel glycolipids consisting only of galactose. The structures of these glycolipids were studied by methylation analysis, periodate oxidation, enzymatic degradation, and proton magnetic resonance spectroscopy. Three glycolipids were characterized as galactosyl(beta 1 leads to 1)ceramide, galactosyl(beta 1 leads to 6)galactosyl(beta 1 leads to 1)ceramide, and galactosyl(beta 1 leads to 6)galactosyl(beta 1 leads to 6)galactosyl(beta 1 leads to 1)ceramide. Data indicating that the 4th glycolipid might be the tetragalactosyl derivative of this series were obtained. The carbohydrate moiety of the 5th glycolipid, in contrast, was composed of fucose, galactose, glucose and N-acetylglycosamine in a molar ratio of 1 : 2 : 1 : 1.

Carbohydrates↗
PubMed1981

Orthostatic hypotension in familial amyloid polyneuropathy: treatment with DL-threo-3,4-dihydroxyphenylserine.

We measured plasma norepinephrine levels in patients with familial amyloid polyneuropathy. Patients with orthostatic hypotension had low basal plasma norepinephrine levels, which did not increase after postural change. On the basis of biochemical findings that suggest depletion of peripheral norepinephrine, DL-threo-3,4-dihydroxyphenylserine, an immediate precursor of norepinephrine, was given orally. Six hundred mg of this drug induced substantial and sustained elevation of blood pressure for several hours, and plasma norepinephrine content increased. Daily administration for 4 weeks improved postural dizziness and syncope, and daily activity increased.

Adult↗