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F S KANTOR

Publications and source records attributed to F S KANTOR.

12 recordsLinked to original sources
PubMed1965

FIBRINOGEN PRECIPITATION BY STREPTOCOCCAL M PROTEIN. I. IDENTITY OF THE REACTANTS, AND STOICHIOMETRY OF THE REACTION.

Evidence confirming the identity of fibrinogen-precipitating factor and streptococcal M protein is provided by the demonstration of bactericidal, mouse protective, and long chain-producing antibodies in the sera of rabbits immunized with washed M-fibrinogen precipitates. Two precipitin lines were observed in immunoelectrophoresis of human plasma vs. rabbit anti-M-fibrinogen antiserum; no precipitin reactions were observed between human serum and rabbit anti-M-fibrinogen antiserum. The reaction between M protein and fibrinogen was stoichiometric; a constant equimolar ratio of reactants was observed in precipitates formed with a wide range of M protein concentrations.

Animals↗
PubMed1965

FIBROGEN PRECIPITATION BY STREPTOCOCCAL M PROTEIN. II. RENAL LESIONS INDUCED BY INTRAVENOUS INJECTION OF M PROTEIN INTO MICE AND RATS.

Intravenous injection of Type 1 streptococcal M protein into mice and rats produced lesions confined to renal glomeruli. Thrombi of eosinophilic amorphous material, seen to occlude glomerular capillaries, were shown to contain M protein and fibrinogen. Gradual regression of the morphological lesions was observed during the 3 weeks following injection. Initial abnormal proteinuria and azotemia returned to control levels by the end of the 1st week; a second rise in urinary protein excretion and urea retention was demonstrated in some rats coincident with appearance of anti-M antibodies. The mechanism of renal localization of streptococcal M protein by means of a complex with fibrinogen was suggested, which may comprise an initial phase in the pathogenesis of acute poststreptococcal glomerulonephritis.

Animals↗
PubMed1963

Studies on artifical antigens. I. Antigenicity of DNP-polylysine and DNP copolymer of lysine and glutamic acid in guinea pigs.

Dinitrophenyl conjugates of poly-L-lysine, varying in percentage conjugation and molecular weight have been found to induce skin reactivity and precipitating antibodies in guinea pigs. At best, 40 per cent of immunized animals developed delayed and immediate responses to DNP-polylysine, which is believed to reflect constitutional differences among the animals assayed. Only those animals capable of responding to DNP-polylysine, responded to an immunologically distinct poly-alpha-amino acid consisting of glutamyl and lysyl residues ("copolymer glu-lys"). The percentage of animals responding to the DNP-polylysine antigen decreased as the degree of DNP conjugation increased.

Animals↗
PubMed1960

Preparation and antigenicity of M protein released from group A, type 1 streptococcal cell walls by phage-associated lysin.

The lysis of Group A type 1 streptococcal cell walls by phage-associated lysin has been described. In the preparation of lysin, a new semisynthetic non-protein media to support growth of the propagating strain of Group C streptococci was employed. Following lysis of the cell walls, the resulting digest was partially purified by ion-exchange chromatography and ammonium sulfate precipitation. In addition to M protein, the resulting preparation (called lysin M protein) contained the group-specific carbohydrate and the T protein-but did not contain antigens, detectable by precipitin tests, which cross-reacted with absorbed heterologous group or type antisera. Capillary precipitin reactions between the lysin M protein and type-specific antiserum did not occur in the presence of high ionic strength buffers; these buffers did not similarly affect precipitin reactions of acid M protein. Type 1 lysin M protein is shown to be a good antigen. A total of 1.5 mg. injected intradermally in saline produced bactericidal antibody in eight of nine rabbits; when injected in adjuvant in one rabbit, protective serum antibodies developed. Streptococci grown in sera from seven of nine rabbits immunized with lysin M protein demonstrated significantly longer chains than when grown in normal rabbit serum. Antibody as demonstrated by each of these three tests was shown to be type-specific. No local or systemic toxicity was noted following intradermal injection in rabbits of lysin M protein.

Animals↗
PubMed1958

Accessory plasma factors involved in the bactericidal test for type-specific antibody to group A streptococci. I. A typical behavior of some human and rabbit bloods.

The bloods of two apparently healthy human beings, of 25 studied, failed to produce a strong bactericidal test for type-specific antibody to the M protein of group A streptococci under in vitro conditions wherein most human blood leukocytes rapidly phagocytize and destroy virulent organisms in the presence of anti-M antibody and accessory plasma factors. The defect in bactericidal activity of these two individuals is associated with the plasma rather than with the blood leukocytes. Leukocytes suspended in these atypical plasmas showed a characteristic delay in the rate of activation of phagocytosis. Although previously the bloods of laboratory animals (except monkeys) had been reported to be much less active than human blood in this system, occasional exceptions were encountered in rabbits in this study. Two rabbits were found whose bloods were as strongly bactericidal against streptococci, in the presence of type-specific antibody, as the blood of the average "normal" human being. The atypical behavior of some human and rabbit bloods in the bactericidal test may be explained by variations in accessory plasma factors that are as yet unidentified and that influence the rate of phagocytosis of virulent streptococci in vitro in the presence of type-specific antibody.

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