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Biomedical subjects

H Ohashi

Publications and source records attributed to H Ohashi.

At least 433 records · Page 24Linked to original sources
PubMed1987

Comparison of intraperoxisomal localization form and properties of amphibian (Rana catesbeiana) uricase with those of other animal uricases.

Liver uricase of bull frog (Rana catesbeiana) was present as the soluble form in the peroxisomal matrix and consisted of four identical subunits with a molecular weight of 30,000. These properties were identical with those of fish liver uricase but differed from mammalian liver uricase. Purified uricase from the frog liver was insoluble in hypertonic, hypotonic and detergent solutions at pH 6-9. This insolubility was the same as mammalian liver uricase but differed from fish liver uricase; fish uricase was soluble in these solutions. The frog liver uricase did not cross-react immunologically with both uricases of fish and mammalian liver. An immunological cross-reactivity of liver uricase was observed among amphibia.

Animals↗
PubMed1987

Nerve pathways involved in adrenergic regulation of electrical and mechanical activities in the chicken rectum.

Peripheral nerve pathways responsible for adrenergic inhibition of mechanical and electrical activities in the chicken rectum and receptors mediating the adrenergic inhibition were investigated in isolated extrinsically-innervated rectum of the chicken. Electrical stimulation of the anal end (Ra) or the ileal cut end (Ri) of Remak's nerve, or perivascular nerves (P) elicited relaxation of the rectum pretreated with atropine (0.5 microM) and hexamethonium (0.3 mM) to block the cholinergic and non-cholinergic, non-adrenergic excitatory innervations. Ri stimulation was much less effective than Ra and P stimulations. The relaxation was shown to be related to cessation of spontaneous spike discharge of the longitudinal muscle which was accompanied by membrane hyperpolarization. The inhibitory effects elicited by Ra and P stimulations, which were prolonged beyond the period of the stimulation, were converted to transient ones by propranolol (3.4 microM). Phentolamine (2.6 microM) reduced effectively the residual effects. In contrast, the effects of Ri stimulation were little affected by these drugs. The present results provide evidence for the existence of two nerve pathways responsible for direct adrenergic inhibitory innervation to the chicken rectum, one running orally in Remak's nerve trunk, leaving it and descending in the branches to the rectum, and the other running as the perivascular nerves along the arterial supplies of the rectum. The direct innervation is mediated predominantly by beta-adrenoceptors.

Animals↗
PubMed1987

Effects of membrane structure on removal of low molecular weight proteins.

Much attention is being devoted to the efficient removal of beta 2-microglobulin from patients on hemodialysis as it may cause amyloidosis. The objective of the present article is to clarify the beta 2-microglobulin removal characteristics of dialysis membranes having varying water contents and pore radii. For membranes of regenerated cellulose, polymethylmethacrylate (PMMA) and ethylenevinyl alcohol (EVA), solute and pure water permeability and water content were determined by the standard methods. Data analysis using a tortuous pore model allows determination of pore radius, surface porosity, and tortuosity, and hence, the sieving coefficient as a function of Stokes radius. Based on the tortuous pore model calculation, little beta 2-microglobulin is removed from patients on hemodialysis by regenerated cellulose and PMMA membranes, but EVA membranes, with a sieving coefficient of 0.5, are capable of removing it. The solute permeability for urea is about 2 orders greater than that for beta 2-microglobulin.

Blood Proteins↗
PubMed1987

The baroreflex-mediated changes in plasma norepinephrine and heart rate in patients with essential hypertension.

Baroreflex sensitivity was evaluated in 19 patients with essential hypertension (EH), 8 patients with borderline hypertension (BH) and 12 age-matched normal controls (N), by measuring the reflex-mediated changes in plasma norepinephrine (NE) and heart rate (RR interval) while a phenylephrine hydrochloride or a sodium nitroprusside solution was infused in graded doses for a total of 24 minutes. Changes in RR interval and plasma NE showed a significant linear correlation to those in mean arterial pressure (MAP) in every subject studied. The slopes of RR/MAP and %NE/MAP tended to be reduced in EH and BH patients during both pressor and depressor stimulations. There was a significant (p less than 0.01) inverse correlation between the basal MAP levels and RR/MAP or %NE/MAP except for %NE/MAP during pressor stimulation. Fifteen minutes after the pressor stimulation was stopped, MAP and RR interval in each group tended to be greater than their baselines. Plasma NE remained significantly (p less than 0.01) depressed in N and BH subjects while those in EH returned to their baselines. When pressor stimulations were repeated twice at intervals of 15 minutes in hypertensive subjects, the second response curves of MAP-RR interval tended to shift slightly to the right while the slopes of the second response curves of plasma NE were significantly (p less than 0.05) reduced compared with the first ones. These findings indicate that an inability of the baroreflex to produce a sustained suppression of sympathetic nerve activity associated with an efficient ability to reset at the higher pressure levels in EH patients results in a continued tendency for blood pressure to rise and contributes to the development of hypertension.

Adult↗
PubMed1987

The amino acid sequence of a smooth muscle-contracting peptide from chicken rectum. Identity to chicken neurotensin.

Previous studies have demonstrated that chicken rectum contains a peptide which exerts a potent, excitatory action on the smooth muscle of chicken rectum, and this peptide is most likely to be chicken neurotensin isolated recently from chicken small intestine. In the present study, the peptide was extracted from 2 kg of chicken rectums, and then it was isolated by gel filtration, ion exchange chromatography, high voltage paper electrophoresis and HPLC. Amino acid analysis of the peptide revealed that it is a tridecapeptide composed of aspartic acid (Asp), glutamic acid (Glu), proline (Pro), alanine (Ala), valine (Val), isoleucine (Ile), two residues of leucine (Leu), tyrosine (Tyr), histidine (His), lysine (Lys) and two residues of arginine (Arg). Its amino acid sequence was determined to be pGlu-Leu-His-Val-Asn-Lys-Ala-Arg-Arg-Pro-Tyr-Ile-Leu-OH. The molecule is identical to chicken neurotensin.

Amino Acid Sequence↗
PubMed1987

[Successful treatment of advanced gastric cancer by combined cisplatinum, mitomycin C and 5-FU administration. A case report].

A 55-year-old woman with gastric cancer underwent laparotomy and was found to have an unresectable tumor at the MC region, characterized by S3 (invasion into the pancreas), N3, P0, H0, Borrmann-II and moderately differentiated tubular adenocarcinoma. She was then treated by combined administration of cis-dichlorodiammine platinum (CDDP), mitomycin C and 5-fluorouracil (5-FU). A complete response was confirmed by upper gastrointestinal roentgenography and endoscopy. Upon reoperation 4 months after the initial laparotomy, a successful total radical gastrectomy with R2 (partially R3) lymph node dissection was performed. Histological examination of the specimens, including the stomach and lymph nodes, revealed no cancer cells in any region.

Adenocarcinoma↗
PubMed1987

[Neurogenic stress gastric ulceration--an experimental study in rats].

Experimental investigation was performed on pathogenesis of neurogenic stress gastric ulceration, i.e. the gastric ulceration occurring under stress in individuals having brain lesions. Male Wistar rats, weighing 250 to 300 g, were divided into the following 4 groups: a) the normal group, b) the subarachnoid hemorrhage (SAH) group, in which 0.2 ml of arterial blood had been injected into the cisterna magna 3 days before, c) the brain lesion group, in which various right hypothalamic nuclei had been coagulated stereotaxically 7 days before, and d) the brain lesion plus SAH group, in which hypothalamic lesions had been produced 7 days before, followed by SAH 3 days before experimentation. They were stressed by applying restraint plus water immersion for 3 hours, and measurements were done on relative ulcer lengths (RUL) in the glandular stomach, gastric acid secretion, gastric mucosal blood flow (MBF) and gastric emptying function. In the SAH group, stress gastric ulcerations, 18.2 +/- 1.4 mm (mean +/- SE) in RUL, were produced, being significantly larger than the value, 10.2 +/- 1.7 mm, in the normal group. Stress ulcerations were milder than the normal control in the rats having lesions at the preoptic area (POA) or the anterior hypothalamic area (AHA), while the rats having ventromedial hypothalamic (VMH) lesions showed marked ulcerations, 21.8 +/- 2.7 mm in RUL, which were significantly larger than those in the normal group. Addition of SAH to VMH lesions did not cause a further increase in RUL.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗