Search PubMed⌕ Search

Biomedical subjects

T Shibazaki

Publications and source records attributed to T Shibazaki.

At least 91 records · Page 5Linked to original sources
PubMed1979

Comparative studies on eight dissolution method using 21 commercial chloramphenicol tablets and a nondisintegrating benzoic acid tablet.

Eight dissolution methods (beaker, rotating basket, oscillating basket, solubility simulator, rotating flask, and column) were evaluated using 21 commercial film-coated chloramphenicol (I) tablets and a nondisintegrating benzoic acid (II) tablet. The relative agitating intensities obtained from different dissolution methods were compared through the relative zero-order nondisintegrating tablet dissolution rate constants. Correlation coefficients between I dissolution rate parameters (lag time, T20, T50, and T80) were determined. Significant correlation was observed for the lag time among seven methods, and all pairwise regression lines passed through zero except one. The regression line slopes reflected the relative destructive force intensities produced by each dissolution method on the coated I tablet films. The seven dissolution methods could be classified into two main groups according to correlations of four dissolution rate parameters. The classification criterion agreed well with that based on the agitation method. However, dissolution methods may not be interchangeable even though they belong to the same dissolution method group.

Benzoates↗
PubMed1979

Dissolution systems for chloramphenicol tablet bioavailability.

The relationship between chloramphenicol (I) tablet bioavailability and in vitro dissolution rates was examined. The effect of solid food on the I tablet and powder bioavailability was also studied. Five tablets of I were selected for bioavailability testing on the basis of the dissolution rates of 18 I tablets (250 mg) determined by several methods. Compound I, 500 mg, was administered orally to five subjects, following overnight fasting, according to a crossover design. The bioavailability parameters were obtained from urinary I excretion. Among the five formulations studied, only one tablet (F) showed significantly poorer bioavailability. The dissolution rates at pH 1.2 did not give the same rank order as the bioavailability. The dissolution rate of Tablet F showed remarkable pH dependency. The dissolution rates at pH 4 showed good correlation with in vivo bioavailability data. The bioavailability of I powder was not affected by solid food. Tablet F, which had poor bioavailability in the fasting state, showed good bioavailability when administered just after the standard breakfast.

Adult↗
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↗
PubMed1977

Physiologically controlled selective thalamotomy for the treatment of abnormal movement by Leksell's open system.

In the course of stereotaxic thalamotomy by Leksell's open system in 20 cases of abnormal movement, recording and stimulation of the subcortical structures have been performed by means of two semimicro-electrodes introduced parallel to the frontal plane. Taking advantage of simultaneous recording and electrical stimulation through these two electrodes, several critical points in the caudate nucleus and thalamus have been clearly delineated. Thus in each individual case an outline of the thalamic configuration in the frontal plane could be obtained, so that the final therapeutic lesion was placed with good precision at the lower-most border of VL or Vim nucleus. It has been shown that the physiologically determined minimum lesion resulted in satisfactory alleviation of the abnormal movements without notable untoward effects.

Electroencephalography↗