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Biomedical subjects

T Miyaoka

Publications and source records attributed to T Miyaoka.

15 recordsLinked to original sources
PubMed1992

Effects of pentobarbital tolerance and dependence on convulsant and GABAA receptor antagonist binding.

Experiments were performed which examined the effects of pentobarbital tolerance and dependence on GABAA receptor antagonist binding. In rats implanted with pentobarbital pellets for 7 days, followed by 24 hours of withdrawal, there was a significant decrease in the latency of TBPS-induced seizures and an increase in [35S]TBPS binding in the frontal cortex. The pentobarbital tolerant rats had a significant increase in the low affinity KD of [3H]SR95531 binding. Removal of the pellets for 24 hours caused a reversal of the effect on the low affinity KD and caused a decrease in the number of low affinity binding sites. In vitro addition of pentobarbital to binding assays produced a decrease in the number of high affinity [3H]SR95531 binding sites without changing low affinity binding. In the cerebellum, the binding in none of the treatment groups was significantly different from placebo. These observations suggest that pentobarbital tolerance and withdrawal cause changes in the properties of the GABAA receptor antagonist binding site which are different from those caused by in vitro exposure to the drug.

Animals↗
PubMed1991

Triazole antifungals. IV. Synthesis and antifungal activities of 3-acylamino-2-aryl-2-butanol derivatives.

New triazole compounds were designed and synthesized as potential inhibitors of the fungal cytochrome P-450 14 alpha-demethylase. In testing for antifungal activity against a mouse systemic Candida albicans infection, (2R,3R)-3-acylamino-2-aryl-2-butanol derivatives III exhibited remarkably high efficacy after oral or parenteral administration. The structure-activity relationships of these amidoalcohols were evaluated.

Antifungal Agents↗
PubMed1991

[The clinical evaluation of tactile sensation in entrapment neuropathy using detection threshold of vibrotactile stimuli].

Two mechanoreceptive units, the rapidly adapting unit (RA unit) and the Pacinian corpuscle unit (PC unit), play an important role in the sensibility of the hand. It has been shown that detection thresholds of vibrotactile stimuli directly reflect the neural activity of the RA unit (in cases of stimulation below 50 Hz) and the PC unit (in cases of stimulation above 50 Hz). We applied this psychophysical approach to a clinical evaluation of tactile sensation in entrapment neuropathy. The detection thresholds of sinusoidal stimuli (25, 50, 100, 200, 300 Hz) were measured in 11 cases of carpal tunnel and 8 cases of cubital tunnel syndrome. By comparing the threshold curve of affected fingers with that of normal ones we were able to determine the severity of sensory disturbance. It was assumed that the PC unit was selectively disturbed in the early stages of the disease and that the RA unit was also disturbed in advanced stages.

Adult↗
PubMed1990

Two-year oral chronic toxicity and carcinogenicity study in rats of diets fumigated with methyl bromide.

A chronic toxicity and carcinogenicity study was conducted by feeding diets containing 80, 200 or 500 ppm total bromine following fumigation with methyl bromide, a diet containing 500 ppm potassium bromide, or a basal diet alone to groups of 60 male and 60 female Fischer (F344) rats for up to 2 yr. Ten males and ten females from each group were killed after wk 52 and 104 for urinalysis, haematology, blood biochemistry and pathology. Rats that were killed in extremis or found dead during the study and all rats that survived to the end of the study were also subjected to pathological examinations. In rats fed the diets fumigated with methyl bromide there were no marked toxic changes, except for a slight depression of body-weight gain from wk 60 onwards in males of the 500-ppm group, and tumour incidence was unaffected. Rats given a diet containing potassium bromide did not show any treatment-related changes. It was concluded that residues of up to 500 ppm total bromine in diets fumigated with methyl bromide are not carcinogenic in F344 rats of either sex and that the maximum no-effect level is 200 ppm (6.77 mg total bromine/kg body weight/day) in males. The maximum no-effect level could not be determined in females.

Animals↗
PubMed1990

Triazole antifungals. II. Synthesis and antifungal activities of 3-acyl-4-methyloxazolidine derivatives.

Triazole compounds with an oxazolidine ring were designed and synthesized as a potential inhibitor of the fungal cytochrome P450 14 alpha-demethylase. In testing for antifungal activity against a mouse systemic Candida albicans infection, (4R,5R)-3-acyl-4-methyloxazolidine derivatives 4 exhibited remarkably high efficacy after oral or parenteral dosing. The potent activity of 4 is hypothesized to be a consequence of a structural similarity between 4 and lanosterol, a target molecule of the cytochrome P450 14 alpha-demethylase. Highly stereoselective synthesis of these oxazolidines is also described.

Animals↗
PubMed1977

Estimation of serum acid proteases at pH 1.8 and pH 3.5 in patients with duodenal ulcer, gastric ulcer and gastric carcinoma.

Using a simple hemoglobin method on the basis of Anson-Mirsky's method, acid protease levels in serum were measured at pH 1.8 (pepsin) and pH 3.5 (gastricsin) in 18 healthy controls and 14 patients with duodenal ulcer, 19 patients with gastric ulcer and 18 patients with gastric cancer. Though acid protease activity in pH 1.8 in duodenal ulcer has a tendency to show a little higher level than healthy controls, there is no significant difference in acid protease levels between controls and each of three diseases.

Adult↗
PubMed1977

Dynamic aspects of gastric emptying in patients with peptic ulcer according to ulcer stages.

The pattern and the time of gastric emptying were investigated in 38 patients with peptic ulcer and 7 healthy volunteers using the double-sampling method. The pattern of gastric emptying assumed the following three attitudes, that is, exponential (44%), quadratic (29%) and unclassified (27%) pattern. These patterns appeared to depend on the distance from the gastric angle to the pyloric ring measured from X-ray pictures in the upright position. There was no significant difference in the gastric emptying time in patients with peptic ulcer according to its site. During follow-up observations of the same case, the gastric emptying time had a tendency to shorten in patients with duodenal ulcer while it showed no definite variation in patients with gastric ulcer.

Acute Disease↗