Recalcification

Stage of treatment Fibrinogen, pg% Fibrinolytic activity, % Ht,% Time of serum recalcification, seconds Serum tolerance to heparin, min... 

Heparin content, °/ /o Thrombin time, min Recalcification time, min... 

Determined as follows 1 mg of the copolymer was dispersed in a 0.1 ml solution of non-ionogenic surface-active compound at 37 °C for 10 min 0.2 ml of plasma were added to the suspension the mixture was incubated for 15 min at 37 °C 0.1 ml thrombin (5 U/ml) (thrombin time) or 0.2 ml of 0.025 M CaCl2 (recalcification time) were then added and the time of clot formation was measured. 

Human saliva is supersaturated with basic calcium phosphate, to allow recalcification and protection of the dental enamel. Precipitation in the saliva is prevented by certain calcium binding proteins, which include statherin268 (a 5380 molecular weight tyrosine-rich protein that also contains many proline and glutamic acid residues), and a group of proline-rich proteins.269... 

Compound Dosage Recalcific- ation Thrombin Thromboplastin... 

Fig. 7 C Plasma clotting time measurements, including measurements of plasma recalcification time [PRT], plasma thromboplastin-catalyzed clotting time [PTT], and thrombin-catalyzed clotting time [TT]...

In Vitro Clotting Tests. The plasma recalcification time of citrated human plasma was determined in the presence of heparin-PVA beads and control PVA beads without heparin. Various amounts (10-200 mg) of gel were incubated with 0.5 mL of plasma at room temperature for 5 min. After the addition of 0.5 mL of0.025M CaCl2, the time to clot was noted by tilting the test tube gently each minute, until the beads clumped together or were found to stick to the test tube wall. 

In Vitro Activity of Bound Heparin. The prolongation of the thrombin time caused by the addition of heparin-PVA beads to plasma is contrasted with the negligible effect of PVA beads without heparin in Figure la. A similar prolongation was observed for the plasma recalcification time (Figure lb). In both cases, clumping or adhesion of the beads caused presumably by fibrin was the end point of the assay. 

In a plasma to Teflon. recalcification experiment. several unidentified proteins were adsorbed to HEMA but not... 

Blood compatibility of the control PCL and chitosan-g-PCL-h-PEG/heparin multilayer-deposited PCL membrane was measured using static platelet adhesion and plasma recalcification time experiments Cytocompatibity of scaffolds with endothelial cells and vascular smooth muscle cells (vSMCs)... 

It has been noted that hypercrosshnked polystyrene does not adsorb proteins to the same extent as do conventional polystyrene or macroporous polystyrene [190]. Most probably, the open-work hypercrosshnked material does not expose a dense hydrophobic surface for the proteins to adsorb. The same is true for the marked inertness of both the new hypercrosshnked mesoporous poly-DVB materials and industrial hypercrosshnked sorbent MN-200 toward whole blood ceUs. Blood (50 mL) spiked with citric acid freely flows through a 5 mL column fiUed with beads of the above sorbents, contrary to many other coated carbon-type and polymeric hemosorbents tested under identical conditions, where blood coagulation and colurrm clotting were found to occur [359]. Indeed, the new mesoporous poly-DVB sorbent, without any additional modification of the surface, was found to be sufficiently biocompatible and not cause any early coagulation effect in a standard plasma recalcification test. 

The modified polymer beads [347] passed all of the standard battery of biocompatibility tests required by the International Organization for Standardization guidelines (ISO 10993). The tests included in vitro coagulation tests (plasma recalcification time), hemolysis study (extraction method), cytotoxicity study using the ISO elution method, etc. In in vivo experiments, extracts of the polymer beads did not elicit pyrogenic irritation or sensitization reactions in laboratory animals (acute systematic toxicity study in the mouse, acute intracutaneous reactivity study in the rabbit, rabbit pyrogen study). 

The relatively high incidence of thromboembolic phenomena in women on the pill prompted an examination on the effects of the estrogenic and/or progesteronic components in the pill on the surface charge characteristics of the vascular system. Electrophoretic mobilities of erythrocytes and platelets and blood coagulation times were determined with samples of blood drawn from 33 women on the pill and 30 control subjects. The electrophoretic mobilities were reduced thrombin recalcification times were not affected but thrombin times and partial thromboplastin times were shortened. 

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