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Biomedical subjects

M Miyazaki

Publications and source records attributed to M Miyazaki.

At least 1,027 records · Page 57Linked to original sources
PubMed1979

[A fundamental study on a bioassay for the antiphlogistic effect of topically applied antiinflammatory agents (author's transl)].

To establish a reliable laboratory assay for quantitating topical anti-inflammatory efficacy, the method of Tonelli et al was modified by employing felt fixed forceps, felt and sharp punch in Wistar rats. Croton oil, applied topically to the rat ear, elicited an acute phlogistic response which was maximal 6 hr after the application. The phlogistic response elicited by a single topical application of croton oil (1, 2, 5 and 10%) was increased in a dose-dependent manner, and croton oil, 5%, induced 63.2% increase of ear weight and was the optimal concentration for the experiment. Using this procedure, the antiphlogistic potencies of two corticoids were assayed under conditions of a blind test. ED50 of betamethasone valerate and diflucortolone valerate was 0.26 mg/ml and 0.0097 mg/ml, respectively, in Wistar rats, and 0.86 mg/ml and 0.016 mg/ml in Sprague Dawley rats, suggesting that diflucortolone valerate has an antiphlogistic potency of 27-56 relative to that seen with betamethasone valerate with minor differences in the strain of the rat. Our method should prove to be a useful assay for rapidly quantitating antiphlogistic activities of topically applied corticoids.

Administration, Topical↗
PubMed1978

Circulatory effect of respiratory maneuvers.

The circulatory effects of three kinds of respiratory maneuvers--maximum breathing, voluntary hyperventilation, and the Valsalva maneuver--on cerebral blood flow, brachial blood flow, heart rate, and systolic blood pressure were investigated by means of the on-line Doppler ultrasonic technique in 20 men. Arterial gas contents (PO2, PCO2, pH) were also examined. Cerebral blood flow was increased or showed the biphasic response (increase in the former and decrease in the latter part of the maneuver) with maximum breathing. Cerebral blood flow was decreased with voluntary hyperventilation. The cerebral blood flow was maintained at a same level during the maneuver or tended to return to the control level. Cerebral blood flow was decreased in the Valsalva maneuver. There was a transient but conspicious increase of the cerebral blood flow immediately after the maneuver.

Adult↗
PubMed1978

Circulatory effect of jet noise, with special reference to cerebral circulation.

The circulatory effect of jet noise on heart rate, systolic blood pressure and cerebral blood flow was investigated by means of the on-line Doppler ultrasonic technique devised by the author in 20 normal young males, normal elderly males and elderly patients with cerebral vascular disease. The jet noise ranged from 60 dBA to 110 dBA. Heart rate and systolic blood pressure showed slight and transient increase at the level of over 90 dBA. Although the cerebral blood flow was increased at the level of 90--110 dBA, conspicuous dissociation was observed between the vertebral artery and internal carotid artery. The vertebral artery dominant type was more frequent than the internal carotid artery dominant type. Headache and discomfort due to the noise were observed in all the subjects. The above facts suggest that the jet noise induces dysfunction of the autonomic nervous system and various kinds of psychosomatic diseases.

Adult↗
PubMed1978

Contractile responses of isolated dog mesenteric arteries to angiotensin I, II and III.

The addition of angiotensin (Ang-) I, II and III caused a dose-dependent contraction of helically cut strips of dog mesenteric arteries. Tachyphylaxis developed following repeated additions of angiotensins. Average median effective concentrations of Ang-I, II and III were 3.7, 0.8 and 2.5 X 10(-8) M, respectively. Contractile responses to the angiotensins were attenuated to a similar extent by Ang-II antagonists, Sar1 Ileu8 Ang-II and Sar1 Ala8 Ang-II, but were unaffected by phentolamine, methysergide and diphenhydramine. The response to Ang-I was significantly reduced by treatment with bradykinin-potentiator B, while the response to Ang-II was not influenced. It may be concluded that Ang-I, II and III produce contractions possibly by activation of same Ang-II receptors and that contractions induced by Ang-I are associated, to some extent, with a conversion to Ang-II in the arterial wall.

Angiotensin I↗
PubMed1978

Primary culture of adult rat liver cells. III. Hormonal effects on cytological and biochemical properties of primary cultured cells.

The effect of various hormones on cytological and biochemical properties of cultured hepatic cells were investigated in order to obtain long-term survival of the hepatocytes with adult liver functions in primary culture. Insulin supplementation of the culture medium enhanced the attachemnt efficiency of cells in primary culture without affecting either maintenance of morphological characters of epithelial cells or retention of liver-specific functions in cultured cells. A combination of dexamethasone and insulin was apparently effective in stimulating the formation of a monolayer of polygonal cells with granular cytoplasm and in maintenance of liver-specific functions for relatively longer periods. Supplementation with either dexamethasone or hydrocortisone alone enhanced tyrosine aminotransferase activities in cultured cells for at least 4 days postinoculation. These steroid hormones also allowed growth of small epithelial cells with clear cytoplasm and maintenance of increased albumin production for 8 days after inoculation. The roles of these hormones in the primary culture of isolated hepatic cells are discussed in the present paper.

Animals↗
PubMed1978

Estimation of neural noise. Functional anatomy of the human thalamus.

In the course of stereotactic thalamotomy, the neural noise level of subcortical structures was estimated quantitatively with the aid of two semimicro-electrodes. The neural noise showed several characteristic features in terms of its amplitude and discharge pattern so that it was correlated with the possible anatomical substrate, thus providing the functional anatomy of the subcortical structures. The study on saggital plane revealed a systematic difference of the noise level between VL and Vim-Vc that could be explained by the different cell size in respective nucleus. Several exceptional cases were also presented, emphasizing the neural noise study in stereotactic surgery.

Adult↗