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Biomedical subjects

K Tanabe

Publications and source records attributed to K Tanabe.

At least 595 records · Page 33Linked to original sources

Penetration of maturating red blood cells by Toxoplasma gondii.

Penetration of Toxoplasma gondii tachyzoites was studied in vitro using murine erythroid cells at different stages of development. Toxoplasma gondii penetrated nucleated erythroblasts and macroreticulocytes from foetal mouse liver and the circulating erythrocytes of foetal, neonatal or severely anaemic adult mice. Immature reticulocytes were more susceptible to penetration than mature ones, indicating that some change in their membrane properties occurred during maturation. The present results confirmed our previous finding that the major erythrocyte membrane-specific proteins do not prevent erythrocyte penetration since these proteins are known to be present in the reticulocyte membrane.

Animals↗

Characterization of multi-layered membrane generated by rabies virus.

Electron microscopy revealed multi-layered membranes within the cytoplasmic inclusion (accumulation of nucleocapsids) produced by rabies virus. When infected BHK cells were maintained at 31 C, an enhancement in production of these membranes occurred in approximately 60% of inclusion-containing cells. Multi-layered membranes were composed of an alternate array of two different layers; an electron-dense, thin membrane and a less dense layer which was thicker. SDS-polyacrylamide gel electrophoresis and immune electron microscopy of isolated multi-layered membrane preparations demonstrated that the structures contained viral G and M2 polypeptides. Our observations suggest that these membranous structures are not a degenerative product of rabies virus infection but rather are related to the replication of viral envelope constituents, although they represent themselves to be an abortive form of viral assembly.

Animals↗

Analgesic activity of diflunisal [MK-647; 5-(2,4-difluorophenyl)salicylic acid] in rats with hyperalgesia induced by Freund's adjuvant.

A method is described for testing analgesia for narcotic or nonnarcotic drugs in rats injected with Freund's adjuvant in the tail, by manipulation of the tail the day after injection, or of the feet after the development of adjuvant arthritis. The method is responsive to a behavioral depressant or an anti-inflammatory steroid. Diflunisal (MK-647; 5-(2,4-difluorophenyl)salicylic acid] exhibited activity in this assay after oral administration with potency about 25 times greater than that of aspirin, about 3 times that of glafenine and twice that of zomepirac. The onset of activity was within a 1/2 hour for narcotic analgesics but required about an hour for non-narcotic compounds. With the latter, the peak of activity was not attained until 2 to 4 hr, depending on the compound. The peak for diflunisal was delayed until the 3rd or 4th hour, but the onset of action was more prompt and the duration greater as the dose was increased. [14C]Diflunisal was concentrated to some extent in the inflamed tissue after adjuvant injection. Peak levels both in plasma and tissue appeared about 2 hr before peak analgesic effect. Repeated administration of large doses produced neither tolerance nor sensitization to the analgesic action of diflunisal. Naloxone and naltrexone did not antagonize the action of the compound, but when morphine and diflunisal were given together, the overall effect was enhanced.

Analgesics↗

Use of logit paper in determination of superoxide dismutase activity in human blood cells.

Superoxide dismutase activity of the human blood cells was determined by the capacity to inhibit nitrite formation from hydroxylammonium chloride. Relationship between percentage of nitrite formation and amount of purified human erythrocyte superoxide dismutase was plotted on conventional graph paper, double log and logit papers. A comparison of the results showed that a linear relationship was obtained only with the logit paper, and thus a more accurate and simple estimation of the activity can be made on a single determination of the specimens.

Ammonium Chloride↗

Modifications of primiaquine as antimalarials. 2. 5-Phenylthio and 5-anilino derivatives of primaquine.

A number of 5-phenylthio and 5-anilino derivatives of primaquine have been prepared which are less toxic but less active than primaquine itself in murine and monkey antimalarial screens. It is apparent that the toxicity of primaquine can be diminished by introduction at position 5 of phenylthio, anilino, or phenoxy groups. However, the best hope for concomitant retention of high activity would seem to reside with the phenoxy moieties.

Animals↗