Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:4.2.3.23 (GAS)
 957 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To elucidate the pathophysiology of acute shock caused by serogroup A streptococci (GAS), GAS were given intravenously to 25 pigs. Short-time infusions of GAS (n=11) caused variable and unpredictable responses. A continuous infusion of 5x108 cfu/kg/h (n=8) caused pulmonary hypertension, arterial hypotension, and reduced cardiac output and liver perfusion, progressing to circulatory shock within 2-4 h. Halving the infusion rate (n=6) induced a more gradual development of shock and doubled the mean survival time from 2.1 to 4.0 h. Mean tumor necrosis factor-alpha levels (+/-SE) increased from 25+/-1 to 40+/-3 pg/mL. Only slight signs of organ dysfunction were observed, which indicates that this is primarily a model of acute septic shock. Light microscopy revealed moderate inflammatory reactions in lung, liver, and gut biopsy samples, although high numbers of viable, M-typeable GAS were recovered from tissues. The present model may be useful to study mechanisms involved in acute septic shock as well as therapeutic interventions.
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PMID:Acute serogroup A streptococcal shock: A porcine model. 1088 90

In a porcine model of Gram-positive sepsis, 28 juvenile pigs were studied to evaluate the effect of a continuous infusion of live serogroup A streptococci (GAS) on the activation of coagulation and fibrinolysis. Plasma levels of thrombin-antithrombin (TAT) complexes, tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) activities were measured using commercially available kits. The continuous infusion of GAS [(3-5) x 10(8) colony-forming units/kg per h] caused early signs of severe septicaemia in the pigs, with pulmonary hypertension, systemic hypotension, reduced cardiac output and liver hypoperfusion, ultimately leading to shock with a high mortality. There was a sequential and ordered activation of the coagulation, fibrinolytic and antifibrinolytic systems. GAS infusion induced a gradual, maximally 2.5-fold increase in plasma TAT levels. Plasma t-PA activity levels peaked at 2 h (nine-fold increase), whereas the peak of PAI-1 activity was delayed (eight-fold increase at 4 h). These findings are similar to changes observed during endotoxin infusion. This procoagulant state favours disseminated intravascular coagulation and microthrombus formation, ultimately threatening tissue viability.
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PMID:Systemic activation of coagulation and fibrynolysis in a porcine model of serogroup A streptococcal shock. 1093 4