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Biomedical subjects

Y Doi

Publications and source records attributed to Y Doi.

At least 469 records · Page 26Linked to original sources
PubMed1985

Limited in vivo susceptibility of the South American monkey -Cebus apella- to type 1 poliovirus: physical and histopathological observations after intraspinal inoculation.

Type 1 polioviruses (an attenuated strain, Sabin 1 LSc 2ab and a virulent strain, Mahoney) were inoculated intraspinally into the South American Cebus monkey Cebus apella. Neither physical symptoms nor histological changes in the central nervous system were observed after inoculation of attenuated Sabin strain. But the virulent Mahoney strain caused flaccid paralysis in two of three monkeys. In these two paralyzed monkeys, definite specific histological changes were observed with spreading of the lesions to places far from the inoculation site, i.e., the cervical cord and brain. These results suggest that Cebus apella has limited susceptibility to type 1 poliovirus.

Animals↗
PubMed1985

[Prolonged action preparation of cefaclor].

This study was conducted to develop a prolonged action preparation of cefaclor (CCL) which can offer, with the twice-a-day administration, as much effectiveness as its conventional preparation (Kefral capsule) with the 3 times-a-day administration. Absorption site of CCL in gastrointestinal tract, preparation form (enteric coated granules) which slowly release CCL, dissolution property of the form, and mixed ratio of the form and rapid release form (nonenteric coated granules) were studied and complex granules consisting of 40% of nonenteric coated granules and 60% of enteric coated granules which dissolve at pH 6 were chosen as a prolonged action preparation of CCL. Bactericidal activity of the prolonged action preparation (S6472) was confirmed to be the same as that of the conventional preparation by comparative viable cell count study in which concentrations of CCL simulated to plasma concentrations following the administration of S6472 at the dosage of 375 mg b.i.d. and the conventional preparation at the dosage of 250 mg t.i.d. were used. From the above, S6472 is considered to be a prolonged action preparation of CCL which serve our purpose. Since S6472 can be given with the twice-a-day administration, its daytime administration is not necessary. Therefore, S6472 is considered to be much useful preparation for the patients.

Adult↗
PubMed1984

Actin polymerization. The effect of brevin on filament size and rate of polymerization.

Fluorescent probes covalently bound to actin or to the actin binding protein, brevin, have been utilized to provide information about actin filaments formed in the presence of brevin as well as about the effect of brevin on the rate of polymerization. At actin to brevin ratios of 10:1 to 100:1, the observed diffusion coefficients of filaments, as measured by fluorescence photobleaching recovery using rhodamine-labeled actin or fluorescein-labeled brevin, are similar to those calculated from theoretical considerations for rigid rods. At lower brevin concentrations, the observed diffusion coefficients for actin filaments are lower than predicted, indicating that the filament structure is closer to that observed in the absence of brevin where filaments are immobilized due to interactions between them. The fluorescein-labeled brevin was found to be about as effective in influencing actin polymerization as unlabeled brevin. Using pyrene-labeled actin, we show that brevin binds 2 mol of monomeric actin. We conclude that at sufficiently high brevin concentration there is one brevin molecule per actin filament. From measurements of the initial rate of polymerization at 5.9 microM actin in the presence of brevin, we calculate both the apparent elongation rate constant and dissociation rate constant from one end (presumably the slow-growing end) of the actin filament. The former is highly dependent on Mg2+ concentration while the latter is not.

Actins↗
PubMed1984

Transmission electron microscopic study of calcium phosphate formation in supersaturated solutions seeded with apatite.

The present study examined crystal growth on enamel and synthetic apatite seed surfaces in dilute supersaturated solutions by means of transmission electron microscopy. At all supersaturations, new growth initially appeared on the ends of the seed crystal. In solutions undersaturated with respect to octacalcium phosphate (OCP), this growth was needlelike in appearance. Above the solubility point for OCP, the growth frequently took the form of thin, platelike crystals. The relevance of these findings to precursor phase formation is discussed.

Animals↗
PubMed1984

HLA antigens in Japanese patients with narcolepsy. All the patients were DR2 positive.

A surprisingly high association between an HLA-DR locus antigen and narcolepsy was revealed in the Japanese. All 40 Japanese patients with narcolepsy (22 males and 18 females) were confirmed to be DR2 positive. However, the DR2 of the patients was found to associate negatively with Bw52, whereas Bw52-DR2 is the commonest haplotype in normal Japanese population. These data suggested that a "disease" allele predisposing to narcolepsy was inherited with relatively rare haplotypes with DR2 in the Japanese.

Female↗
PubMed1984

Inhibition of seeded growth of enamel apatite crystals by amelogenin and enamelin proteins in vitro.

The effect of enamel matrix proteins on the seeded growth of enamel apatite crystals was studied in stable supersaturated solutions at pH 7.4 and 37 degrees C. Of the two major protein classes in the enamel matrix, the enamelins were considerably more effective than the amelogenins in retarding seeded growth. However, the amelogenin species that did show significant inhibitory activity are those known to be lost first from the enamel matrix during the rapid mineralization stage of enamel maturation.

Amelogenin↗
PubMed1984

Development and evaluation of a new peroral test agent GA-test for assessment of gastric acidity.

A new peroral test capsule, GA-Test, containing riboflavin (5 mg) granules coated with polyvinylacetal diethylaminoacetate (AEA) for assessing gastric acidity without intubation was developed and evaluated for usefulness. GA-Test is based on the tracing in the urine of riboflavin, which is released in the stomach only in the presence of acidic fluid and is absorbed. Due to the film coating, riboflavin released very quickly at a pH of less than 5, and not at all at a pH of greater than 6. GA-Test gave a significant correlation, quantitatively, with peroral Gastrotest in assessing acidity, a non-intubation method which had been marketed in Japan prior to 1980. GA-Test results allowed division of the subjects into two groups i.e., subjects having low (hypo- or anacidity) gastric acidity and those having high (normal or hyperacidity) gastric acidity, GA-Test results agreed well with results of intubation (around 91.4%; 32 out of 35 cases) and were easily reproduced during the evaluation.

Adult↗
PubMed1984

Well-controlled comparative study of the clinical effectiveness of intravenous mexiletine and procainamide on ventricular premature contraction.

In a well-controlled study the clinical efficacy of a single intravenous injection of mexiletine (3 mg/Kg) on ventricular premature contractions was compared with that of procainamide (10 mg/Kg) using continuous electrocardiographic recordings. Of the 56 subjects studied, 55 were analyzed. These consisted of 28 cases in the mexiletine group and 27 in the procainamide group. The backgrounds of both groups were considered to be equivalent. Effectiveness on VPC ("marked and moderate improvement", as judged by the subcommittee) was seen in 88% of the mexiletine group and 84.6% of the procainamide group. This difference was not significant. The duration of efficacy was almost the same in the 2 groups. Overall improvement was the same as improvement in VPC. No significant difference was observed in the incidence of side effects. Five patients in the mexiletine group and 3 in the procainamide group reported side effects. The main side effect was light-headedness in the mexiletine group and a decrease in blood pressure in the procainamide group. A decrease in blood pressure was observed in 1 case in the mexiletine group but this was restored by an intravenous infusion of noradrenaline. Mexiletine had little effect on blood pressure, while procainamide induced a drop in the systolic pressure. This difference was significant. Overall utility ("markedly and moderately useful", as judged by the subcommittee) was seen in 84.0% of the mexiletine group and 84.6% of the procainamide group. There was no significant difference between the 2 groups. From the above results, it is concluded that mexiletine (3 mg/Kg) is as efficacious as procainamide (10 mg/Kg) in the treatment of VPC but that, unlike procainamide, mexiletine has little effect on blood pressure.

Adolescent↗
PubMed1984

Effect of angiotensin III on blood pressure, renin-angiotensin-aldosterone system in normal and hypertensive subjects.

The biological actions of angiotensin III (AIII) in animals have been reported to be stimulation of aldosterone secretion and vasoconstriction. However, the biological actions of AIII in human essential hypertension (EH) have not been evaluated. Twenty ng/Kg/min of AIII was infused intravenously for 30 min into 6 normal subjects and 24 patients with EH. The systolic blood pressure was elevated significantly, from 116 +/- 5 (mean +/- SD)/68 +/- 4 to 137 +/- 9/74 +/- 5 mmHg in normal subjects and from 155 +/- 29/95 +/- 17 to 176 +/- 26/106 +/- 20 mmHg in EH patients. The elevation in systolic BP of low-renin EH patients was significantly larger than that of normal-renin EH patients. Plasma renin activity (PRA) decreased significantly from 1.64 +/- 1.07 to 1.21 +/- 1.05 ng/ml/hr in normal subjects and from 0.88 +/- 0.66 to 0.76 +/- 0.63 ng/ml/hr in EH. Plasma aldosterone concentration (PAC) increased significantly from 57 +/- 34 to 116 +/- 34 pg/ml in normal subjects and from 66 +/- 56 to 91 +/- 24 pg/ml/ in EH. There was no significant difference between the increase of PAC in low-renin EH and in normal-renin EH. Plasma cortisol concentration (PCC) did not change in these subjects. There were no significant relationships between the changes of PRA and PAC or PRA and blood pressure. These results suggest that the pressor action of AIII appeared in relation to the basal PRA in EH. In EH, PRA is suppressed by the direct action of AIII in the kidney and neither by increased PAC nor by increased blood pressure. The small changes in blood pressure caused by AII infusion suggest that a test using an AIII infusion for aldosterone stimulation would be preferable to an angiotensin II infusion.

Adolescent↗