P52 Coagulation is a complex process that results in blood forming clots at tissue and vessel sites where damage has occurred, thereby stopping bleeding. Cardiac surgery extensively alters the normal coagulation process both intentionally and unintentionally. More often than not, cardiac surgery uses cardiopulmonary bypass (CPB) for intervention and surgical correction. Before initiating cardio...

Thrombin-induced clotting times were inversely proportional to fibrinogen concentrations within the range of 98 to 2900 nmol/L; these reciprocal velocity measurements had units of seconds per clot. By analogy with classical enzyme kinetics, we defined rectangular hyperbolic parameters where Km(clot) ranged from 0.14 to 0.56 mumol/L and kclot from 0.020 to 0.075 clot per second. Specificity rati...

The clotting values of 50 patients with glomerulonephritis were examined. Three different coagulation groups were recognised: those with normal clotting values (group 1); those with high concentrations of factor VIII but otherwise normal clotting results (group 2); and patients who showed the presence of an activator of the intrinsic coagulation pathway, indicated by the presence of a short act...

We have studied the contribution of platelets to the coagulation of plasma and the effects of activation or inhibition of platelets on the coagulation process in unanticoagulated fresh whole blood (subsequently termed native blood). For this purpose, we have used a free oscillation rheometer (FOR), the ReoRox4, a new instrument that enables noninvasive viscoelastic measurements of clot formatio...

Clotting is critical in limiting loss of hemolymph and initiating wound healing in insects as well as in vertebrates. Clotting is also an important immune defense, quickly forming a secondary barrier to infection, thereby immobilizing, and possibly killing bacteria directly. Here, we describe methods to assess clotting and to extract the clot from Drosophila larval hemolymph by using aggregatio...

The GuQin, a seven-stringed zither, is China's oldest stringed instrument, with a history of some 3000 years. In Chinese, “Gu” means old and “Qin” means musical instrument. Historically, GuQin was referred to as " Qin " in most ancient Chinese writings. Owing to its long history, it has been widely called GuQin during the last 100 years. This summer in China, we conducted an interview with Feng...

An extension of the corresponding states approach of Pitzer and of Lee and Kesler (PitzerLee-Kesler (PLK) strategy) based on the work of Teja et al. (PLKT strategy) provides a clear pedagogical setting for describing the underlying basis of the PLK strategy itself and also its extension to families of non-normal fluids. Application of the strategy to two families of nonnormal fluids is illustra...

We investigate the aggregation of amphiphilic molecules by adapting the two-state Muller-Lee-Graziano model for water, in which a solvent-induced hydrophobic interaction is included implicitly. We study the formation of various types of micelle as a function of the distribution of hydrophobic regions at the molecular surface. Successive substitution of nonpolar surfaces by polar ones demonstrat...

Plasma antithrombin activity was measured using an amidolytic method (substrate Chromozym TH) and a clotting method. The mean antithrombin values found in 76 hospital outpatients were 9.4 micronmol/min/ml with the amidolytic procedure and 100.1% of antithrombin activity with the clotting procedure. The two methods correlate fairly well (r = 0.85, P less than 0.01) and show satisfactory reproduc...

The antithrombotic action of a heparin is not necessarily confined to its effects on the clotting mechanism. Yet we restrict ourselves here to a discussion of the action of heparin on thrombin generation in platelet poor and platelet rich plasma for two reasons. In the first place it is more likely than not that inhibition of the clotting mechanism is at least one of the major working arms of h...