Predominance of beta-structure in solubilized zona pellucida from porcine ova

The isolated zona pellucida from porcine ova was effectively solubilized in water at 60 degrees C within one hour. The circular dichroic spectra of zona in water with and without dithiothreitol showed the beta-form. Although sodium dodecyl sulfate partially induced helical structure, the beta-form was considerably retained. These results indicate that the zona glycoproteins have a structure-forming potential for the beta-structure and the hydrogen bonds of the beta-structure stabilize the supramolecular complex of the zona pellucida. The beta-form was also detected in zona solubilized by tryptic digestion. Porcine acrosin, however, did not solubilize the zona.

The quantitative determination of the paw-swelling activity of pertussis vaccine with special reference to its responsible toxic components

A method has been developed for quantitative determination of the early appearing mouse paw swelling activity of pertussis vaccine. Mice were inoculated with the vaccine into the left hind paws. The difference in the thicknesses between the inoculated and the uninoculated paws was taken as the swelling response in 16 hr after inoculation. It was transformed into logarithm as a response metameter. A linear log dose-log response regression line was obtained over a relatively wide range of doses of the vaccine. No deviation from parallelism was significant among the regression lines of different vaccines tested. The swelling activities relative to that of a reference vaccine of diphtheria-pertussis-tetanus combined (DPT) vaccines recently produced in Japan were determined. The relative activities ranged from 0.6 to 2.5, being twice the mean width of the 95% confidence interval of the relative activity. Further experiments showed that the activity significantly correlated with endotoxin and histamine-sensitizing factor (HSF) but not with lymphocytosis-promoting factor (LPF). In addition, the multiple regression analysis of such relationship suggested that the swelling activity is accounted for by the combined action of endotoxin and HSF. A model experiment with a mixture of the two toxins supported this conclusion.

Histopathological studies of reactions in mice injected with aluminum-adsorbed tetanus toxoid

Histopathological observations of changes at the injection site in mice were made for 20 weeks after a single intramuscular (im) injection of aluminum hydroxide-adsorbed tetanus toxoid (Alum-TT), plain tetanus toxoid (TT), or aluminum adjuvant (Alum alone). Marked injury to muscle fibers and infiltration of neutrophils around the aluminum remnants were observed, and some microabscesses were occasionally formed, after im injection of Alum-TT. Some mature alum-granulomas were seen in the Alum-TT group, while the Alum alone group had only a few immature alum-granulomas. The TT group showed only slight injury to muscle fibers and acute inflammation at an early stage. In the Alum-TT group, well-developed lymphold tissues and granulomatous lesions were still observable even 20 weeks after the injection; however, these changes had already diminished in the Alum alone group by that time. These findings could serve as good models for undesirable local reactions to aluminum-adjuvanted vaccines.

Development of a simple serological method for diagnosing leptospirosis: a microcapsule agglutination test

A passive microcapsule agglutination test for the diagnosis of leptospirosis was developed by utilizing chemically stable microcapsules instead of sheep erythrocytes. In the test, sonically disrupted antigens of leptospira were sensitized to microcapsules treated with glutaraldehyde. Compared with the microscopic agglutination test, the passive microcapsule agglutination test showed a relatively genus-specific tendency and a 4- to 32-fold-higher sensitivity. The sensitized microcapsule antigens were stable for at least 1 year. The microcapsules coupled with mixed antigens can be used as a serodiagnostic screening test for diseases caused by various types of leptospira. The test, which is very simple and reproducible and requiring no specific training, can be employed easily as a routine test in diagnostic laboratories.

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.

Antibody activities of immunoglobulins in anti-leptospiral horse sera

Antileptospiral sera from hyperimmunized horses were fractionated by gel filtration on Sephadex G-200 or by starch block electrophoresis. The fractions were examined quantitatively for leptospiricidal, agglutinating and complement fixing activities. The leptospiricidal activity was higher in the 78 globulin fraction than in the 19S globulin fraction, while the agglutinating activity was shared by both the fractions being higher in the 19S fraction. Complement fixing activity was found evenly in both the fractions. Leptospiricidal and complement fixing activities were higher in gamma-globulin than in T-globulin, while the agglutinating activity was comparable in the two globulin fractions. That is, the agglutinating activity may not always behave along with the leptospiricidal activity. The results were discussed in connection with the therapeutic antiserum product for human use.

Cross antigenicities of Leptospira interrogans serovar copenhageni Shibaura strain for preparing biological products in Japan

Cross protective antigenicities of Leptospira were studied with 16 antisera to 13 serovars of Leptospira interrogans and a virulent strains "Shibaura (V)", which is now considered to belong to serovar copenhageni, for challenge. The antisera of the rabbits highly immunized with various serovar live antigens were examined for leptospiricidal activity; cross immunity was recognized only in the same serogroup, Icterohaemorrhagiae. Serovar icterohaemorrhagiae lacks a prt of the antigenic components of copenhageni, but the antiserum to the former showed potent leptospiricidal activity to Shibaura (V). Anti-copenhageni immune serum absorbed with the icterohaemorrhagiae antigen did not show any protective activity to Shibaura (V).

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.

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.