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Biomedical subjects

Y Miyake

Publications and source records attributed to Y Miyake.

At least 577 records · Page 32Linked to original sources
PubMed1985

Hydrophobic interaction in Candida albicans and Candida tropicalis adherence to various denture base resin materials.

The effects of hydrophobicities of substrate surfaces on microbial adherence were examined by using Candida albicans and Candida tropicalis and 21 denture base resin materials. With increasing surface free energy of resin plates, increasing adherence of C. albicans and decreasing adherence of C. tropicalis were observed. The surface free energy of C. albicans is higher than that of all resin material surfaces, and C. tropicalis has surface free energy lower than that of all materials used. In calculation of the changes of free energy accompanying the adherence, the higher adherence tendency was accompanied by a lower value for the free energy change in both species. From a different standpoint, the closer the surface free energy of the substrate surface and the microorganism, the higher was the probability of adherence.

Candida↗
PubMed1984

The morphology of bone mineral as revealed by small-angle X-ray scattering.

Diffuse small-angle X-ray scattering of oriented bone from bovine femur and canine femur was described in terms of an ideal isotropic two-dimensional two-phase system which consists of mineral phase and organic phase. The microstructure of powdered, randomly-oriented bone from bovine femur was found to be affected by grinding. An analysis of small-angle scattering from oriented bone showed that bone mineral was to a large extent in the form of needle-like particles with a 50-60 A the diameter, and the dimension of organic phase transverse to the longitudinal axis of long bone was in the range 45-55 A. The intersect distribution function was directly calculated from the scattering intensities, and the results strongly suggested the presence of needle-like mineral with sharp edges.

Animals↗
PubMed1984

Reduced amplitude of oscillatory potentials in female carriers of X-linked recessive congenital stationary night blindness.

We studied the electroretinograms of 12 female carriers in eight families with X-linked recessive congenital stationary night blindness. Forty-two normal eyes served as controls. The age and refractive error of the normal eyes were matched to those of the female carriers. We found the amplitude of the oscillatory potentials (01 + 02 + 03 + 04) in carriers was statistically smaller than in normal eyes. Seventeen of 22 eyes of carriers were more than +/- 2 S.D. away from normal, and the mean value was statistically lower than normal (P less than .001). The peak time of oscillatory potentials, and the amplitude of the a-, b-, scotopic b-, and photopic b-waves were all within the normal range. The selective abnormality of the amplitude of the oscillatory potentials is a new finding in female carriers in X-linked recessive congenital stationary night blindness.

Adult↗
PubMed1984

Stimulus deprivation amblyopia. Simultaneous recording of local macular electroretinogram and visual evoked response.

Local macular electroretinogram (ERG) and visual evoked response (VER) were recorded simultaneously in ten adult patients with stimulus deprivation amblyopia. The fundus was monitored by an infrared television fundus camera. The location of the stimulus spot and eccentric fixating point were also monitored during recording. Responses in amblyopic eyes were compared with those in the normal fellow eyes in terms of the size of the stimulus spot, location of the eccentric fixating point in response to the stimulus spot, and visual acuity. The amplitude of VER in the amblyopic eye showed enhancement when the stimulus spot centering around the fovea involved the eccentric fixating point. The amplitude and peak time of the ERG in the amblyopic eye was essentially normal regardless of the degree of eccentricity of the fixating point and visual acuity.

Adolescent↗
PubMed1984

Preparation of spherically agglomerated crystals of aminophylline.

The spherically agglomerated crystals of aminophylline (theophylline-ethylenediamine complex) can be compounded directly into pharmaceutical formulations without further processing, e.g., granulation. Such crystals were prepared by mixing theophylline and ethylenediamine in a partially miscible solvent system, i.e., organic solvent-ethanol-water. The organic solvents used were chloroform, 1-hexanol, isopropyl acetate, isobutyl acetate, isoamyl acetate, benzene, toluene, n-hexane, or n-heptane. Spherical crystallization depended upon the solubility of theophylline in the solvent mixture. The resultant agglomerated crystals were identical with the theophylline-ethylenediamine complex by IR, X-ray, and differential scanning calorimetry analyses, and was the alpha-, beta-, or gamma-form when the water of crystallization was less than or equal to 0.5, 1.0, and 2.5 mol, respectively. When the amount of ethylenediamine used was less than 1.1 mL (0.0165 mol), the resultant agglomerated crystals were converted to anhydrous theophylline by washing with ethanol. When water was added to the system (greater than or equal to 0.3 mL, i.e., 0.0167 mol), water was occluded in the resultant agglomerates as water of crystallization. Ethylenediamine content in the agglomerated crystals could be controlled by changing the amount of ethylenediamine added in the crystallization solvent.

Aminophylline↗
PubMed1984

Risk factors for worsening to diabetes in subjects with impaired glucose tolerance.

In a 5-12 year follow-up study of 288 subjects with impaired glucose tolerance after a 100-g glucose load, 48 worsened to overt Type 2 (non-insulin-dependent) diabetes with the elevation of fasting blood glucose. The initial level of blood glucose was a major predictor of subsequent worsening to diabetes. In addition, subjects with a lower insulin response to glucose showed a higher incidence of worsening to the disease, irrespective of blood glucose levels. Multivariate analysis indicated that a diminished insulin response and a high maximal body weight index, as well as a high level of fasting and 2-h glucose values at the initial 100-g oral glucose tolerance test were significant independent risk factors for the development of diabetes in Japanese subjects.

Adult↗
PubMed1984

A 13C-NMR study on the interaction of riboflavin with egg white riboflavin binding protein.

The interaction between riboflavin and riboflavin binding protein (RBP) was studied by 13C-NMR spectroscopy. The 13C-NMR spectra of riboflavin selectively enriched at the 2-, 4-, 4a-, and 10a-positions and of (3-[13C]methyl)riboflavin were measured both in the free and RBP-bound forms. The 13C signals of 13C-enriched riboflavin or 3-methylriboflavin bound to RBP are broader than those of the free form, reflecting the restriction of flavin mobility. The 2-, 4-, and 10a-13C signals of riboflavin show no pH-dependent shift in the neutral to acidic pH region either in the bound or free form but the 4a-13C signal of bound riboflavin shifts to lower field in the acidic pH region while that of the free form remains unshifted. The 2-, 4-, 4a-, and 10a-13C signals of free riboflavin exhibited pH-dependent change in the alkaline pH region with a pK value of about 10, in association with the N(3)-H deprotonation. The pH titration profile of the 2-, 4-, and 4a-13C signals of bound riboflavin indicates that the pK of N(3)-H is shifted substantially to the alkaline side when riboflavin is bound to RBP. The 3-methyl-13C signal of 3-methylriboflavin shows no pH-dependent shift whether the compound is free or bound to RBP. The binding of riboflavin and 3-methylriboflavin was also studied spectrofluorometrically. The analysis of the pH dependence of the association constant revealed that one ionizable group in RBP with pK of about 5 and N(3)-H of riboflavin play important roles in the binding. We conclude that RBP preferentially binds the neutral, i.e., N(3)-protonated, form of riboflavin and that the neutral form in turn is stabilized by the hydrophobic environment of RBP surrounding the N(3) region of the bound riboflavin molecule.

Carbon Isotopes↗
PubMed1984

Vitreous fluorophotometry in patients with cone-rod dystrophy.

Eight patients with cone-rod dystrophy were examined by means of vitreous fluorophotometry. The data in three patients with an early stage of retinitis pigmentosa (rod-cone dystrophy) served for comparison. In contrast with the abnormal findings on vitreous fluorophotometry in patients with an early stage of retinitis pigmentosa the value of vitreous fluorophotometry in cone-rod dystrophy was within the normal range in all patients except the two with advanced stages of this disease. Our results suggest that, although both diseases are based on diffuse dystrophy of photoreceptors, and the final stages of the two diseases may show several similar features, the process of breakdown of the blood retinal barrier differs greatly in the two diseases.

Adolescent↗