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Biomedical subjects

K Akama

Publications and source records attributed to K Akama.

At least 73 records · Page 4Linked to original sources
PubMed1980

Analyses for neutralizing activities of immunoglobulin fractions in anti-leptospiral horse antiserum.

The 7S and 19S fraction isolated from hyperimmunized antileptospiral horse sera by Sephadex G-200 gel filtration and gamma- and T-globulin fractions from the antisera by starch block electrophoresis were studied for neutralizing (leptospiricidal) activities against infection with Leptospira. The activity was determined by the intracutaneous method with virulent Shibaura Strain of Leptospira interrogans serovar copenhageni. No significant difference in regression coefficient was observed between the neutralization line with the 19S globulin fraction and that with the 7S globulin fraction, whereas a significant difference in the regression coefficient was observed when the gamma- and T-globulin fractions were compared; the regression coefficient with T-globulin was consistently larger than that with gamma-globulin.

Animals↗
PubMed1975

Studies on the potency test of antiserum for Weils disease by the intracutaneous method.

A method for estimating the leptospiricidal activity of therapeutic antiserum for Weil's disease was improved by using the intracutaneous method in guinea pigs. The neutralization curves between the leptospiral suspensions for challenge and the antisera were shown to be linear over a wide range of the dosis of the pathogen. Although the reproducibility of the neutralization experiments was high, a significant divergence was observed among the slopes in various test samples. However, the trouble due to such a discrepancy in the slope may practically be reduced if such an antiserum preparation that has a regression coefficient close to the mean of those of various neutralization lines constructed by many different products is adopted as the reference. A practical method for the potency test was suggested.

Animals↗
PubMed1974

Intracutaneous infection with Leptospira icterohaemorrhagiae (Shibaura strain) of the guinea pig.

Experimental leptospirosis with Leptospira icterohaemorrhagiae Shibaura strain was studied in guinea pigs. When the pathogen was inoculated intracutaneously to the back of the animals, localized haemorrhage was observed at the inoculated site before the appearance of general haemorrhage. The severity of the local lesion increased progressively until the 7th day of inoculation. The minimum infective dose (MID) or the 50% infective dose (ID50) of the leptospiral suspension was determined by the appearance of the macroscopic local haemorrhage 7 days after inoculation. The MID thus determined was almost comparable with the value determined by the development of general symptoms and signs by conventional ip inoculation. The number of the pathogen per ID50 varied between 6 and 35 in five experiments. The local haemorrhage was effectively protected by active or passive immunization. Microscopically, haemorrhage at the inoculated site was found mainly in the dermis, directly beneath the epidermis in particular, and accompanied with leakage of the pathogen. The pathogen was also detected abunduntly in the thickened epidermal layer covering the inoculated area as well as in the epithelial matrix of hair-follicle, probably due to the proliferation of the pathogen at the site.

Animals↗