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Biomedical subjects

A Takeuchi

Publications and source records attributed to A Takeuchi.

At least 415 records · Page 23Linked to original sources
PubMed1984

The uptake and release of glutamate at the crayfish neuromuscular junction.

The abdominal slow flexor muscle of the crayfish (Cambarus clarkii) was pre-incubated in deuterium-labelled glutamate (glutamate-d5) solution, and the release of glutamate, glutamate-d5 and aspartate in the bath solution was measured by mass fragmentography. The glutamate-d5 was taken up into the preparation and released together with endogenous glutamate. The resting release of glutamate-d5 was 8.2 +/- 0.96 pmol/10 min after the incubation with 0.5 mM-glutamate-d5, and those of endogenous glutamate and aspartate were 7.4 +/- 1.19 and 2.8 +/- 0.81 pmol/10 min, respectively. The release of glutamate-d5 was not significantly increased by nerve stimulation, while that of endogenous glutamate was increased by about 9.7 pmol/10 min above the resting release. The application of high-K solution induced a net increase of 1.9 pmol/10 min in glutamate-d5 release, 6.1 pmol/10 min in endogenous glutamate release and 7.9 pmol/10 min in aspartate release. The relative amount of glutamate-d5 accumulated into the preparation during pre-incubation with 0.5 mM-glutamate-d5 was a few per cent of the endogenous glutamate in the preparation. It is concluded that the exogenous glutamate is taken up mainly into a compartment which differs from that related to nerve evoked transmitter release and that high-K solution has effects on the amino acid release which differ from those of nerve stimulation.

Animals↗
PubMed1984

High-performance liquid chromatographic determination of vitamin D in foods, feeds and pharmaceuticals by successive use of reversed-phase and straight-phase columns.

A simplified and accurate method for the determination of vitamin D in foods, feeds and pharmaceuticals was established by high-performance liquid chromatography (HPLC) using successively reversed-phase and straight-phase columns. About 1-2 g of a sample was accurately weighed and directly saponified. The extracted unsaponifiable matter was subjected to preparative HPLC using a reversed-phase column and a vitamin D fraction was collected. The fraction was subsequently subjected to analytical HPLC using a straight-phase column and vitamin D was assayed by estimating the peak height. The proposed method was applied to various kinds of samples, e.g., fishery products, fish meals, mixed feeds for fish farming and chicken farming, egg yolk, milk products, cattle liver, Shiitake, fortified foods and multivitamin preparations. The results showed that the proposed method was useful for the determination of vitamin D in such samples, because the peak of vitamin D in the profile of the second HPLC was always clearly separated from other concomitants and good recovery was obtained. Therefore, we think that the method is useful as a routine one for the determination of vitamin D in foods, feeds and pharmaceuticals.

Animal Feed↗
PubMed1984

High-performance liquid chromatographic determination of vitamin D3 in fish liver oils and eel body oils.

Identification and determination of vitamin D3 (or D2) and 25-OH-D3 in fish liver oils and eel body oils were carried out. By co-chromatography on HPLC, UV spectra and/or GC-MS, vitamin D3 was identified in naturally occurring fish liver oils and eel body oils, whereas a drop of fish liver oil contained supplemented vitamin D2. 25-OH-D3 was identified only in skipjack liver oil. The HPLC method proposed in a previous report (Takeuchi, A. et al. (1984): J. Nutr. Sci. Vitaminol., 30, 11-25) was confirmed to also be useful for determination of vitamin D3 (or D2) in fish liver oils and eel body oils. The assayed values of vitamin D3 in skipjack and tuna liver oils were 57,760 and 16,200 IU/g, respectively, which were much higher than those in cod and pollack liver oils. The assayed values of vitamin D3 in eel body oils were very low (16-43 IU/g) and showed no appreciable change despite differences in the farming conditions. Determination of 25-OH-D3 in skipjack oil was performed by using HPLC, and the assayed value was 1.8 micrograms/g. This was about 1/800 lower than that of vitamin D3.

Animals↗
PubMed1984

Role of protease--protease-inhibitor complexes in inflammation.

Neutrophils accumulate and release proteolytic enzymes at the site of acute inflammation. These proteases cause tissue damage but are inactivated by protease-inhibitors which have been thought to finish their activity. We paid attention to these protease--protease-inhibitor complexes and examined their roles. Trypsin was used as a proteolytic enzyme and was mixed with an excess of purified alpha 1-antitrypsin (alpha 1AT). The trypsin-alpha 1AT complex was separated from native alpha 1AT by column chromatography. Then the complex was incubated with human neutrophils and lysosomal enzyme release was examined. Significant enzyme release was observed when neutrophils were incubated with the complex, but the amount of enzyme release from the cells was not obvious when neutrophils were incubated with alpha 1AT or trypsin alone. The amount of lysosomal enzyme release was proportional to the amount of the complex added. Further study revealed that the complex did not have much influence on neutrophil chemotaxis or superoxide radical generation, but could activate complement by the classical pathway. These facts indicate that protease--protease-inhibitor complexes play a role in prolonging inflammation.

Adult↗
PubMed1984

Mycoplasma hyopneumoniae infection in pigs immunosuppressed by thymectomy and treatment with antithymocyte serum.

The effect of immunosuppression on Mycoplasma hyopneumoniae infection was evaluated by comparing data from infected, thymectomized, and antithymocyte serum-treated pigs (group 1) with data from infected (group 2) and noninfected (group 3) healthy pigs. After groups 1 and 2 pigs were inoculated intranasally with M hyopneumoniae, mycoplasmas tended to multiply slightly more in the lungs and bronchial lymph nodes of group 1 pigs than that of group 2 pigs. Organisms were also isolated from the spleen of 1 of 3 group 1 pigs. Pneumonia developed in group 2 pigs and was characterized by massive peribronchial, peribronchiolar, and perivascular lymphoid hyperplasia and exudate consisting mainly of polymorphonuclear leukocytes in the alveoli and lumina of the bronchioles and bronchi. In group 1 pigs, perivascular and peribronchiolar cuffings by lymphocytes were less prominent, and the extent of intraluminal exudate was severe and widespread. Bronchial lymph nodes from group 2 pigs had marked hyperplasia of germinal centers and paracortical areas. In group 1 pigs, germinal centers were hyperplastic, whereas in the paracortical areas, depletion of lymphocytes was evident. Seemingly, cell-mediated immune mechanisms are important in the development of pneumonic lesions in enzootic pneumonia of pigs.

Animals↗
PubMed1984

[Estimation of ventricular activation by scintigraphic phase image analysis].

We examined the capabilities of scintigraphic phase imaging in detecting the site of the onset of ventricular activation and the pattern of ventricular activation sequence. ECG-gated equilibrium cardiac blood pool scintigraphy was obtained in the left anterior oblique (LAO) and right anterior oblique (RAO) projections. The standard 12-lead electrocardiograms (ECG) were recorded in 29 cases with various conditions. These included seven normal subjects as controls, eight patients (pts) with complete right bundle branch block (CRBBB), one with CRBBB and left axis deviation (LAD), two with complete left bundle branch block (CLBBB), one with the Wolff-Parkinson-White (WPW) syndrome (B-type), six with right ventricular apical endocardial pacemakers, one with a right ventricular anterior wall myocardial pacemaker, and three with left ventricular apical myocardial pacemakers. Phase image analysis was performed using the first harmonic of the Fourier transform to fit a cosine curve to the time-activity curve of each pixel in the cardiac blood pool study. The results were as follows: In pts with WPW syndrome (B-type) and artificial pacemakers, the site of the earliest phase angle corresponded to the site of the onset of ventricular activation as predicted by ECG and chest radiographs, respectively. However, in normal subjects and in pts with CRBBB, the site of the earliest phase angle was observed at the basal (upper) interventricular septum, which was different from the site of the onset of ventricular activation previously reported by Sodi-Pallares et al and Durrer et al. This discrepancy may have been caused by the paradoxical motion of the basal (upper) interventricular septum in those cases. A similar discrepancy was also observed in pts with CLBBB. Although the site of onset of ventricular activation was predicted to be near the insertion of the anterior papillary muscle of the right ventricle by ECG and electrophysiology, the pixels showing early phase angle were distributed widely along the interventricular septum in those pts with CLBBB. This error in the phase image may have been caused by the extensive paradoxical motion of the interventricular septum. Thus, caution should be exercised in estimating the site of the onset of ventricular activation by phase images. The main direction of phase changes corresponded well to the ventricular activation sequence estimated using ECG in all subjects.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗