[Hemostasis in patients operated on for abdominal hemorrhage. 2. Characterization of the process of activation of blood coagulation system factors. Coagulation inhibitors]. / Gemostaz u bol'nykh, operirovannykh po povodu abdominal'nykh krovotechenii. 2. Kharakteristika protsessa aktivatsii faktorov sistemy svertyvaniia krovi. Ingibitory svertyvaniia.

Haemostasis indexes were estimated in four groups of patients which were isolated by the cluster analysis and operated for abdominal haemorrhages. A tendency or explicit hyperfibrinogenemia have been fixed which are connected with the syndrome of the system inflammation response of the patient in the critical state. The correlation between the indexes of the prothrombin time, activated partial prothrombin time and protein C activity is shown. An analysis of anticoagulants effect suggests it possible to consider the antithrombin III to be the main, stable blood anticoagulant, while protein C is responsible for the operational response of the organism on the part of haemostasis. The decrease of ancystron and thrombin time was recorded in 50% of patients notwithstanding the hyperfibrinogenemia and presence of fibrin fibrinogen degradation products. It is supposed that the acceleration of fibrin polymerization in the examined groups of patients is the mechanism of the organism protection from the blood loss under the given pathology.

Enhanced optical limiting performance of a nonlinear absorber in a solution containing scattering nanoparticles.

The optical limiting performance of a water-soluble porphyrin derivative is shown to be improved when small-sized (400-nm-diameter) nonabsorbing polystyrene spheres are added to the solution. The optical limiting enhancement is attributed to absorption of diffusive photons that experience longer light pathways than ballistic photons. The effect is demonstrated for nanosecond laser excitation at 532 nm.

The effect of large volume paracentesis on plasma volume--a cause of hypovolemia?

Large volume paracentesis, while effectively relieving symptoms in patients with tense ascites, has been generally avoided due to reports of complications attributed to an acute reduction in intravascular volume. Measurements of plasma volume in these subjects have been by indirect methods and have not uniformly confirmed hypovolemia. We have prospectively evaluated 18 patients (20 paracenteses) with tense ascites and peripheral edema due to chronic liver disease undergoing 5 liter paracentesis for relief of symptoms. Plasma volume pre- and postparacentesis was assessed by a 125I-labeled human serum albumin dilution technique as well as by the change in hematocrit and postural blood pressure difference. No significant change in serum sodium, urea nitrogen, hematocrit or postural systolic blood pressure difference was noted at 24 or 48 hr after paracentesis. Serum creatinine at 24 hr after paracentesis was unchanged but a small but statistically significant increase in serum creatinine (+0.1 +/- 0.3 mg per dl, p less than 0.01) was noted at 48 hr postparacentesis. Plasma volume changed -2.7% (n = 6, not statistically significant) during the first 24 hr and -2.8% (n = 12, not statistically significant) during the 0- to 48-hr period. No complications from paracentesis were noted. These results suggest that 5 liter paracentesis for relief of symptoms is safe in patients with tense ascites and peripheral edema from chronic liver disease.

Changes in porphyrin nonlinear absorption owing to interaction with bovine serum albumin.

The changes in the nonlinear absorption of meso-tetrakis (p-sulfonatophenyl) porphyrin (TPPS(4)) caused by its binding to bovine serum albumin (BSA) were investigated in aqueous solutions. The nonlinear absorption depended on the excitation wavelength and pH. It is noteworthy that, for excitation at 640 nm, saturated absorption was observed in a TPPS(4) solution (pH 4.0), whereas reverse saturated absorption occurred for all pH values from 4.0 to 7.0 when BSA was added to TPPS(4). The presence of BSA also initiates an increase in the saturation intensity and a reduction of the nonlinear absorption coefficient. The interpretation of the results based on the binding of TPPS(4) to BSA is corroborated by linear absorption, fluorescence, light scattering, and flash-photolysis data.

Reverse saturable absorption and anti-Stokes fluorescence in mesoionic compounds pumped at 532 nm.

Reverse saturable absorption and fluorescence in liquid solutions of mesoionic compounds are reported. Intensity-dependent transmittance and anti-Stokes fluorescence were observed when the samples were excited with radiation at 532 nm. The results are attributed to excited-state absorption, and the process is understood based on quantum-chemistry calculations that allow the energy levels that correspond to the relevant transitions to be located. A phenomenological description of the nonlinear beam propagation inside the samples is presented, and the nonlinear absorption coefficient as well as the saturation intensity is determined.