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Biomedical subjects

J A FLICK

Publications and source records attributed to J A FLICK.

At least 19 recordsLinked to original sources

Inhibition of the lesions of primary vaccinia and of delayed hypersensitivity through immunological tolerance in rabbits.

In order to gain insight into the pathogenesis of the vesicular lesion of local primary vaccinia infection, newborn rabbits were injected with 0.5 mg of purified inactivated vaccinia virus in an attempt to render them immunologically tolerant. Within a few days these, and control normal rabbits of the same age, were infected on the skin with active vaccinia virus. Most of the tolerant-prepared rabbits failed to develop a local lesion of vaccinia but some developed a very atypical lesion. Successful virus isolation from some, and the presence of inclusions in the tissues of others, indicated successful infection with the virus. Skin allergy to the active virus failed to develop in the test animals but did in the controls. Thus, there was a high degree of correlation between inability to produce delayed hypersensitivity to the viral antigens and failure to develop a vaccinial skin lesion, indicating the probable allergic nature of the primary lesion. There was also a high mortality rate in the group of tolerant-prepared, infected animals. It was associated with a spreading of the virus from the site of infection to the organs, suggesting that generalized vaccinial infection was the cause of death. The observations were compatible with the hypothesis that death was due to viral toxicity. The observations also suggest that, in the animal possessing normal immunological function, active immunity develops rapidly, perhaps at the level of the draining lymph node, to prevent appreciable virus from leaving the site of infection. The absence of detectable immunological activity toward vaccinia virus early in the tolerant-prepared animals and even after 1 month in some of the survivors, indicates that a high degree of immunological tolerance was produced against these microbial antigens.

Animals↗

Studies on the activation of serum protease by an antigen-antibody system.

The results obtained in this study indicate that serum protease is not activated by either a rabbit or guinea pig antiovalbumin-ovalbumin system, in vitro. A precipitin reaction occurring in the presence of a serum protease precursor of three species (human, rabbit, and guinea pig) failed to activate the protease precursor. Furthermore, particulate material as preformed precipitates could not be shown to activate the protease of either human or rabbit serum or their euglobulin fractions. The material presented seems to be further evidence against the postulated role of serum protease in immunologic systems.

Albumins↗