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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.

The estimated need for surgical correction of mandibular prognathism in Norway is 500 patients each year. A questionnaire sent to the maxillofacial surgical units performing orthognathic surgery in Norway showed that in the decade from 1975 to 1985 altogether 1169 patients underwent surgical correction of mandibular prognathism; that is, only 117 patients were treated yearly [corrected]. Extraoral vertical subcondylar osteotomy of the mandibular ramus was the preferred surgical technique, performed on 57% of the patients. Intraoral vertical subcondylar osteotomy of the ramus increased in use and thus seems to be taking over for the extraoral technique. Sagittal split osteotomy was used on 25% of the patients. The different units showed great variation in their preference for the different surgical techniques. Preoperative orthodontics was widely used, on a mean of 77% of the patients. The average hospital stay was 8.5 days, somewhat longer than reported from other countries; however, geographical conditions should be taken into consideration.

The purpose of the present study was to investigate and to compare the interactions of platelets and proteins in flowing non-anticoagulated human blood with the biomaterials polyethylene-terephthalate (Dacron) and polytetrafluoroethylene (PTFE, Teflon). The respective biomaterials were positioned in a parallel-plate perfusion chamber, and exposed to flowing blood for 5 min at wall shear rates characteristic for veins (100/s), medium sized (650/s) and moderately stenosed arteries (2,600/s). Blood-material interactions were morphologically quantified as platelet-surface adhesion, thrombus volume and fibrin deposition. Platelet adhesion to Dacron was highest at the lowest shear rate (13%) and decreased with increasing shear (4% at 2600/s). In contrast, platelet adhesion to PTFE was shear rate independent (17-19%), and significantly higher than the adhesion to Dacron at 2600/s (P0.05). A hallmark of the platelets adherent to PTFE and Dacron was the large percentage of platelets not spread out on the surface. This indicates that both materials were poor platelet activators, even though immunostaining demonstrated the adsorption of the platelet adhesive proteins von Willebrand factor and fibronectin. Adsorption of fibrinogen was also prevailing on both materials. Virtually no thrombi formed on Dacron, while a few small platelet thrombi were observed on PTFE. Less than 1% of the Dacron and PTFE surfaces were covered by fibrin, irrespective of the shear rate. Thus, Dacron and PTFE interact differently with flowing non-anticoagulated human blood, and Dacron is apparently the least thrombogenic material.