These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: A purified group A streptococcal pyrogenic exotoxin. Physiochemical and biological properties including the enhancement of susceptibility to endotoxin lethal shock.
    Author: Kim YB, Watson DW.
    Journal: J Exp Med; 1970 Mar 01; 131(3):611-22. PubMed ID: 4905084.
    Abstract:
    Purified pyrogenic exotoxin from Group A streptococcal filtrates (Streptococcus pyogenes, type 10, strain NY-5) has been characterized primarily as a protein complexed with hyaluronic acid. Amino acid composition and analysis revealed a typical acidic protein with an average molecular weight of 29,000. The purified exotoxin was free of streptolysins O and S, nicotinamide adenine dinucleotidases (NADases), deoxyribonucleases (DNases), mucopeptide, and endotoxins. The biological activity was destroyed when the exotoxin was heated at 65 degrees C for 30 min or boiled for 2 min. The biological activities investigated were pyrogenicity in rabbits (minimal pyrogenic dose-3 hr, 0.07 microg/kg), lethality in rabbits (LD(50), 3500 microg/kg), skin test dose in human skin (> 10(9) skin test doses, per mg toxin), cytotoxicity of rabbit spleen macrophage (Cytotoxic Index 0.5-10 microg/ml), enhancement of susceptibility to endotoxin shock (in rabbits > 100,000-fold), and antigenic analysis (A-type toxin). The exotoxin was immunogenic and it was possible, therefore, to immunize animals against the various toxic activities. The immunity was specific for the A-type toxin. The clinical implications of the highly significant enhancement effect of these exotoxins are discussed. It is suggested that clinical or subclinical infection with Group A streptococci could prepare the host for fatal shock from Gram-negative infections or the inadvertent injection of small amounts of Gram-negative bacterial endotoxins.
    [Abstract] [Full Text] [Related] [New Search]