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Biomedical subjects

A Miyoshi

Publications and source records attributed to A Miyoshi.

At least 19 recordsLinked to original sources
PubMed1992

Changes of colonic vasoactive intestinal peptide and cholinergic activity in rats with chemical colitis.

The vasoactive intestinal peptide concentration was examined in the colonic wall and portal venous plasma of rats with chemical colitis by radioimmunoassay, and the colonic localization was determined with immunocytochemistry. Colonic acetylcholine esterase activity was also measured, and the response of vasoactive intestinal peptide to acetylcholine administration was determined. Colitis was induced by administration of dextran sulfate for three months. The chemical colitis was histologically similar to active human ulcerative colitis. We observed a significant increase of immunostained neurons and nerve fibers and a significant rise in the colonic wall vasoactive intestinal peptide content in chemical colitis rats, while plasma concentrations of the peptide did not change significantly. Colonic acetylcholine esterase activity was significantly elevated in colitis rats compared with control rats. Systemic administration of acetylcholine significantly increased the colonic and plasma vasoactive intestinal peptide concentrations in colitis rats. These findings demonstrated a positive association between colitis activity and an increase of vasoactive intestinal peptide and suggested that increased vagal tone promoted the peptide's release.

Acetylcholine↗
PubMed1992

[An evaluation of temporary clipping during aneurysmal surgery: a retrospective study].

A temporary clipping of a parent artery has been found convenient in facilitating an aneurysmal dissection. This is because it controls the bleeding from an unexpected rupture and keeps the sac collapsed during the operation. Such a temporary arterial occlusion, however, involves the risk of a focal ischemia that may lead to permanent postoperative neurological deficits. Therefore, to evaluate the influence of a temporary clipping on the outcome of an operation, a retrospective study of 302 patients who underwent an operation for a ruptured supratentorial aneurysm between 1981 and 1990 has been conducted. This study has revealed the information that follows: 1) Overall outcomes In patients given no temporary clipping, their postoperative activity in daily living (ADL) grade was good in 70.7%, i.e. ADL 1 or 2, whereas only 46.4% of the patients given a temporary clipping achieved a similar ADL. 2) Influence of the preoperative Hunt and Kosnik neurological classification on the outcome Irrespective of whether a temporary clip had been used, patients with a Hunt and Kosnik grade of 1 or 2 made a good recovery, whereas patients with a grade of 4 or 5 did not. The application of a temporary clip in grade 3 patients led to a poor result, whereas in grade 3 patients given no temporary clipping the results were good. This would seem to indicate that Hunt and Kosnik grade 3 rating is a critical factor in consideration whether a temporary clip should be used or not. 3) Influence of the operative timing on the outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗
PubMed1992

[Effects of stimulation of the vertebral nerve around the proximal vertebral artery on pupil and the autonomic nervous system--a contribution to pathophysiology of Powers' intermittent vertebral artery compression syndrome].

In order to elucidate the pathophysiology involved in Powers' intermittent vertebral artery compression syndrome, the author investigated sympathetic and parasympathetic changes produced by stimulation of nerves around the proximal vertebral artery (the vertebral nerve) in anesthetized and immobilized cats. These changes were observed mainly through pupillary changes, pulse and blood pressure, evoked potentials in the lateral horn of the upper thoracic cord (centrum ciliospinale), in the cervical sympathetic trunk, and in the short ciliary nerve. Electrical stimulation of vertebral nerve and local application of K ion around the vertebral artery produced stimulus-dependent ipsilateral mydriasis; when stimulation of higher strength was applied pronounced ipsilateral and mild contralateral mydriasis and hypertension occurred. Electrical stimulation of perivascular tissue around the subclavian artery proximal to origin of the vertebral artery showed ipsilateral mydriasis; while on stimulating the distal subclavian, the costcervical, the omocervical and the internal thoracic arteries did not show any pupillary response. Neuronal discharges in the lateral horn of upper thoracic cord and in the cervical sympathetic trunk showed stimulus-dependent increases on stimulating the vertebral nerve; while, inhibitory responses were observed in the short ciliary nerve formed by parasympathetic nerve fibers. From the data available, it seems likely that the stimulation of periarterial neural structure of the vertebral artery produced sympathetic excitatory as well as parasympathetic inhibitory neuronal discharges simultaneously may probably be derived from the integrating autonomic center in the hypothalamus.

Animals↗
PubMed1991

Distribution of neurokinin A-like and neurokinin B-like immunoreactivity in human peripheral tissues.

Using specific radioimmunoassay and immunocytochemistry for neurokinin A (NKA) and neurokinin B (NKB), distribution and localization of the two peptides in human peripheral tissues were studied. Both NKA-like immunoreactivity (NKA-LI) and NKB-like immunoreactivity (NKB-LI) were present in the walls of the gut and gall bladder and in the pancreas. In the gut, the values for NKA-LI were 0.56-35.73 pmol/g wet weight, while those in pancreas and gall bladder were 0.64-0.68 and 0.36 pmol/g wet weight, respectively. The values of NKB-LI were 0.45-2.66 pmol/g wet weight in the gut, 0.93-1.65 pmol/g wet weight in the pancreas, and 0.30 pmol/g wet weight in the gall bladder. The immunocytochemical reactivity to both peptides was localized to ganglia of the submucosal and myenteric nerve plexuses in the gut wall, and to neurons in the muscle layer and mucosa of the gut wall. Weak but positive NKA-LI appeared in nerve cells of the pancreas, while NKB-LI was not detectable in the pancreas. Conversely, in the gall bladder wall, NKA-LI was undetectable while a very faint NKB-LI was found in the muscle layer. The localization of NKA corresponded closely to that of NKB in the tissues although the relative concentrations of the peptides varied from organ to organ.

Digestive System↗
PubMed1979

Bartter's syndrome--case report.

A 26-year-old female with Bartter's syndrome associated with Graves' disease is reported. This patient had a history of Graves' disease from the age of 22 and anti-thyroid drug (Methimazole) had been administered for 2 years. Thyroid function returned to normal but general fatigue and polyuria continued. Hypokalemia was diagnosed at 25 years of age and she was referred to our hospital for evaluation. Blood pressure was normal and laboratory data revealed normal thyroid function, hypokalemic alkalosis, high plasma renin activity and high plasma aldosterone concentration. She showed normal pressor sensitivity to norepinephrine infusion, grossly diminished pressor sensitivity to exogenous angiotensin II infusion compared with the normal. A renal biopsy specimen showed juxtaglomerular cell hyperplasia. Electron microscopy confirmed lacis cell (agranular cell) proliferation.

Adult↗
PubMed1979

Ultrastructure of rat renal tubular basement membrane--meshwork structure demonstration by negative staining.

The tubular basement membrane (TBM) (i.e. tubular basal lamina) of rat kidney was shown to be a fine meshwork by electron microscopy after negative staining. Strands of the meshwork formed a regular three dimensional lattice work. The pores of the meshwork were polygonal. There were two main pore sizes: one approximately 30 A in diameter, the other 42--60 A. In view of our previous observation that glomerular and alveolar basement membranes were made up fine meshwork, it is quite possible that the basement membranes of other organs are also made up such fine meshwork.

Animals↗
PubMed1978

Study on the specificity of Shore's method for the determination of histamine in various tissues.

Specificity of Shore's method for the histamine determination was investigated by examining the fluorescence spectrum of the extract from rat gastric mucosa, biopsy specimen of human gastric mucosa, human gastric juice and human whole blood. An almost identical spectrum to that of pure histamine was obtained with the extract from rat gastric mucosa and human whole blood, whereas the spectrum with the extract of human gastric biopsy specimen and human gastric juice was different from that of histamine. By means of high-performance liquid chromatography, an approximately three times more concentrated extract from human gastric mucosa gave a distinct peak of histamine while a hundred times concentrated gastric juice gave no measurable peak of histamine. Fluorescence spectrum of the substances which might be extracted with histamine was examined. The ratio of the fluorescence of histidine to that of equimolar concentration of histamine at the wave length for histamine determination was 4.62%. From the above results, it has been concluded that Shore's method is useful for the determination of histamine contents in the gastric mucosa and whole blood if approximately 5% contamination with histidine is taken into consideration.

Animals↗
PubMed1978

[Student apathy].

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Adolescent↗