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Biomedical subjects

T Maeda

Publications and source records attributed to T Maeda.

At least 1,549 records · Page 86Linked to original sources
PubMed1977

Use of rabbits for GI drug absorption studies.

A novel procedure to control the stomach emptying rate in rabbits is presented. Rabbits were given a special solid diet for 1 week, and then the gastric contents were washed out with saline. Then the rabbits were muzzled to prevent coprophagy during the night. Fifty grams of special soft diet given to the "stomach-emptying-controlled" rabbit transferred exponentially from the stomach into the small intestine and almost disappeared from the stomach within 5 hr. Griseofulvin, indomethacin, or nalidixic acid was administered in a hard gelatin capsule or tablet, with subsequent feeding of a special soft diet. Good correlations were observed between the plasma level-time curves of these drugs in the stomach-emptying-controlled rabbits and in human subjects.

Animals↗
PubMed1977

Transmembrane phospholipid motions induced by F glycoprotein in hemagglutinating virus of Japan.

Transfer of phospholipid from the envelope of hemagglutinating virus of Japan (HVJ) to erythrocyte (RBC) membrane and the virus-induced transfer of phospholipid between RBC membranes were studied using spin-labeled phosphatidylcholine (PC). The transfer of PC from membranes labeled densely with PC to unlabeled membranes was followed by the peak height increase in the electron spin resonance spectrum. The two kinds of transfer reactions took place very rapidly as reported previously. To obtain further details, the transfer reactions were studied with HVJ, HVJ inactivated by trypsin, HVJ harvested early, HVJ grown in fibroblast cells, the fibroblast HVJ activated by trypsin, influenza virus, and glutaraldehyde-treated RBCs. The results demonstrated that the viral F glycoprotein played a crucial role in the transmembrane phospholipid movements as well as in the fusion and hemolysis of RBCs. The transfer from HVJ to RBC's occurred partially through an exchange mechanism not accompanying the envelope fusion. This was shown by a decrease in the exchange broadening of the electron spin resonance spectrum of released spin-labeled HVJ (HVJ) and also by an increase in the ratio of PC to viral proteins incorporated into RBC membranes. HVJ modified RBC membrane so as to be able to exchange its phospholipids with those of inactive membranes such as fibroblast HVJ, influenza virus, glutaraldehyde-treated RBC'S, and phosphatidylcholine vesicles. HVJ affected the fluidity of RBC membranes markedly, the environments around PC being much fluidized. The virus-induced fusion was discussed based on close apposition of the membranes by HANA proteins and on the destabilization and fluidization of RBC membranes by F glycoproteins.

Animals↗
PubMed1977

[Effects of electrical stimulus upon L-strain cells. (Part 2)--Response of the cells to alternative current prior to cultivation (author's transl)].

In order to examine the effects of voltage, current time and frequency of the alternative current on cell multiplication and morphology during initial stage of cell cultivation, alternative currents of varying intensity were applied to the L-strain cells in the tissue culture medium, i.e. YLH solution supplemented with 5% bovine serum which was considered as an electrolyte solution. The following results were obtained: 1) The rates of cell multiplication depended on the frequency (0.01 Hz-10 KHz), when voltage and current time were kept constant. In particular, they were remarkably depressed in the low frequency range. In a certain frequency range, a maximum value of the rates of cell multiplication was recorded. It was considered that there is certainly a least inhibitive frequency range in the rates of cell multiplication. 2) The lower and the shorter the voltage and current time were, the lower were the frequency level at the threshold of marked inhibition of the rates of cell multiplication brought. 3) An arbitrary equation for the relationship between the rates of cell multiplication and frequency was determined: The rates of cell multiplication upon cell multiplication were proportional to (A + log F), where A was a constant value and F was the applied frequency. According to the equation above, the depression upon cell multiplication was calculated, when the values of voltage and current time were given. 4) It was found that the results of the rates of cell multiplication were parallel to the results of the morphological observations. It was presumed that the main factor governing cell multiplication during application of the alternative current was due to change of the compositions of medium which was electrolyzed.

Animals↗