Viscoelastic measurements of platelet function, not fibrinogen function, predicts sensitivity to tissue-type plasminogen activator in trauma patients.

BACKGROUND: Systemic hyperfibrinolysis is a lethal phenotype of trauma-induced coagulopathy. Its pathogenesis is poorly understood. Recent studies have support a central role of platelets in hemostasis and in fibrinolysis regulation, implying that platelet impairment is integral to the development of postinjury systemic hyperfibrinolysis. OBJECTIVE: The objective of this study was to identify if platelet function is associated with blood clot sensitivity to fibrinolysis. We hypothesize that platelet impairment of the ADP pathway correlates with fibrinolysis sensitivity in trauma patients. METHODS: A prospective observational study of patients meeting the criteria for the highest level of activation at an urban trauma center was performed. Viscoelastic parameters associated with platelet function (maximum amplitude [MA]) were measured with native thrombelastography (TEG), and TEG platelet mapping of the ADP pathway (ADP-MA). The contribution of fibrinogen to clotting was measured with TEG (angle) and the TEG functional fibrinogen (FF) assay (FF-MA). Another TEG assay containing tissue-type plasminogen activator (t-PA) (75 ng mL(-1) ) was used to assess clot sensitivity to an exogenous fibrinolytic stimulus by use of the TEG lysis at 30 min (LY30) variable. Multivariate linear regression was used to identify which TEG variable correlated with t-PA-LY30 (quantification of fibrinolysis sensitivity). RESULTS: Fifty-eight trauma patients were included in the analysis, with a median injury severity score of 17 and a base deficit of 6 mEq L(-1) . TEG parameters that significantly predicted t-PA-LY30 were related to platelet function (ADP-MA, P = 0.001; MA, P < 0.001) but not to fibrinogen (FF-MA, P = 0.773; angle, P = 0.083). Clinical predictors of platelet ADP impairment included calcium level (P = 0.001), base deficit (P = 0.001), and injury severity (P = 0.001). RESULTS AND CONCLUSIONS: Platelet impairment of the ADP pathway is associated with increased sensitivity to t-PA. ADP pathway inhibition in platelets may be an early step in the pathogenesis of systemic hyperfibrinolysis.

Glycerol prevents dehydration in lipid cubic phases.

Lipid cubic phase samples dry out and undergo phase transitions when exposed to air. We demonstrate experimentally and theoretically that adding glycerol controllably lowers the humidity at which cubic phases form. These results broaden the potential applications of cubic phases and open up the potential of a new humidity-responsive nanomaterial.

Professional attitudes toward denture adhesives: A Delphi technique survey of academic prosthodontists.

STATEMENT OF PROBLEM: The use of denture adhesives and their role in prosthodontics has been an intriguing and conflicted topic, both in clinical practice and dental education. PURPOSE: This study generated discussion, and if possible, obtained a consensus on a series of issues related to denture adhesives among a group of leading academic prosthodontists. MATERIAL AND METHODS: The Delphi Technique survey method was used. It consists of a series of survey questionnaire rounds to a panel of experts to either develop a consensus (>70% agreement) or to clarify the reasons for multiple schools of thought on a topic. A 24-item Delphi questionnaire was sent to an expert panel that consisted of a 33% regionally stratified random sample of program directors of undergraduate complete denture courses in US dental schools. The 5 major topic areas on denture adhesives addressed by the questionnaire items were (1) general perceptions, (2) specific clinical uses/misuses, (3) patient education, (4) inclusion in dental curricula, and (5) overall opinions of utility. RESULTS: Of the 18 randomly selected panelists, 94% (n = 17) agreed to participate, with either 16 or 17 fully participating in each of the 3 survey rounds. The panel achieved consensus and clearly concluded that denture adhesives: (1) are a useful adjunct in denture prosthesis services, having specific roles in both the fabrication and postinsertion phases; (2) had the potential for misuse, both by dentists and by patients; and (3) should be an integral part of patient education for all denture patients and of the undergraduate dental curriculum. However, the panel was unable to achieve consensus on whether denture adhesives should be used at the postinsertion phase for immediate denture patients and whether, on the whole, they were a beneficial adjunct in denture patient management (59% agreed they were). The panelists also clearly expressed their concerns that neither dentists nor patients should use denture adhesives as a substitute for either good clinical practices or proper denture maintenance routines. CONCLUSIONS: This panel of leading academic prosthodontists concluded that denture adhesives are a useful adjunct in denture prosthesis services, with specific roles in both fabrication and postinsertion phases. They also indicated that only through education, for dentists and patients, would the dual goals of maximizing the beneficial aspects of denture adhesive use while minimizing the misuse of denture adhesives be achieved.