Reactions of Rabbits to Non-Hemolytic Streptococci

Derick

1929

Self Cite

Rabbits immunized intravenously with living culture or nucleoproteins of non-hemolytic streptococci react to subsequent intracutaneous inoculations with homologous streptococci with smaller and harder lesions than are shown by normal animals similarly inoculated; and they do not develop the general manifestations of hypersensitiveness such as are shown by animals previously inoculated into the tissues with the same cultures. A rabbit may react to intracutaneous inoculation with non-hemolytic streptococci in one of four ways, depending on whether it is normal, hypersensitive, immune or cachectic. Most normal animals show a secondary reaction about 10 days after inoculation with suitable strains of non-hemolytic streptococci; hypersensitive, allergic, or hyperergic animals show much larger lesions than do normals with the corresponding doses of the same streptococci, and practically never show secondary reactions; immune animals show smaller and harder early lesions and usually do not have secondary reactions if they are fairly well immunized. Cachectic animals show very soft and rapidly fading primary reactions and no secondary reactions.

mentioning

confidence: 99%

mentioning

confidence: 99%

Reactions of Rabbits to Non-Hemolytic Streptococci

Derick

1929

Self Cite

“…of 0.1 co. of a 1 : 100 dilution. The size of lesions produced is recorded in terms of cubic millimeter volume, estimated from measurements of two diameters and the height of each lesion, as described elsewhere (2).…”

Section: Methodsmentioning

confidence: 99%

“…It has been demonstrated that chronic low-grade infection, or numerous localized foci of inflammation induced in the rabbit by repeated minute inoculations with relatively avirulent (green or indifferent) streptococci, evoke a state of hypersensitivity to the bacteria (1,2). This hypersensitivity may be demonstrated by hyperreaction to minute doses injected intracutaneously, by an ophthalmic reaction following application of the bacteria to the scarified cornea, and by death in from 24 to 48 hours after intravenous doses tolerated by normal animals (2).…”

mentioning

confidence: 99%

Reaction of Rabbits to Streptococci: Comparative Sensitizing Effect of Intracutaneous and Intravenous Inocula in Minute Doses

Schultz

1932

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It has been demonstrated that chronic low-grade infection, or numerous localized foci of inflammation induced in the rabbit by repeated minute inoculations with relatively avirulent (green or indifferent) streptococci, evoke a state of hypersensitivity to the bacteria (1, 2). This hypersensitivity may be demonstrated by hyperreaction to minute doses injected intracutaneously, by an ophthalmic reaction following application of the bacteria to the scarified cornea, and by death in from 24 to 48 hours after intravenous doses tolerated by normal animals (2). Suitable preliminary intravenous inoculations result in another type of response; the characteristic hyperergic reactions are not induced; skin lesions are smaller than in normal animals and quickly assume a hard nodular character without much macroscopic evidence of edema; ophthalmic tests are negative; the responses are those of immune animals (3).It is possible that these differences in response of animals to the two modes of preliminary inoculation might be conditioned by a small antibody content in the animals inoculated intracutaneously compared with a larger amount in those inoculated intravenously. The induction of high degrees of bacterial hyperergy with repeated small inocula of streptococci suggested comparing the effect of similar small doses given intravenously; for from both routes a low antibody production might be expected because of the small amount of antigen introduced. Thus, the question as to whether these differences in the reactive state of the tissues might be the result of suitable doses of antigen, rather than of its site of action, focal or general, seemed open to further 591

“…The development and extent of sensitization was judged by means of the ophthalmic reaction (2). In addition, graded doses of bacteria were administered intradermally, and the size and course of the resulting lesions were observed daily for 72 hours (1). In the case of unsensitized controls, however, the intradermal inoculations were omitted, inasmuch as no increment of allergy, however slight, was considered desirable.…”

mentioning

confidence: 99%

Perivascular Reactions in Lung and Liver Following Intravenous Injection of Streptococci Into Previously Sensitized Animals

Hitchcock

Camero

1934

Self Cite

Intravenous inoculation of small doses of non-hemolytic streptococci into previously sensitized rabbits is usually followed by the appearance of perivascular cellular aggregates in lung and liver. The characteristic cell in these aggregates is moderately large, with vesicular nucleus, prominent nucleoli, clumped chromatin, and basophilic cytoplasm. In addition, the lesions contain small lymphocytes and granulocytes. This lesion is easily differentiated by architecture and cell content from normally occurring lymphoid aggregates, and from spontaneous rabbit hepatic cirrhosis. This mononuclear response does not occur when the intravenous dose is large enough to cause death of the animal within 24 hours. In spleen and lymph nodes the characteristic basophilic cells, which normally occur in these organs, are present in increased numbers. Following intravenous treatment alone, or sensitization without intravenous treatment, the lesions occur much less frequently, and when present are smaller and more sparsely found. Inasmuch as in the present series of experiments this lesion was not found in normal animals, and infrequently in those treated by the intravenous route alone, it is suggested that the preliminary sensitization serves to enhance the animal's reactivity to the antigen. In this way a small dose of bacteria is capable of eliciting the cellular phenomenon, which in unsensitized animals appears only when larger doses of antigen are administered over longer periods of time. Too large a dose of antigen, however, results in shock and cell death rather than proliferation.