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Enzyme-induced liberation of components from seven different radiolabeled polyurethanes was monitored by radiolabel counting of the incubation solutions and product isolation by high performance liquid chromatography (HPLC). The polyurethanes were selected to reflect variations in the hard-segment chemistry, soft-segment chemistry, and polyurethane(More)
Presently, there is a lack of fundamental understanding regarding changes in collagen's molecular state due to mechanical damage. The bovine tail tendon (BTT; steers approximately 30 months) was characterized and used as an in vitro model for investigating the effect of tensile mechanical overload on collagen susceptibility to proteolysis by acetyltrypsin(More)
The current study has investigated the influence of esterase activity (80-400units/ml) on the biodegradation of polycarbonate-urethanes (PCNUs) by cholesterol esterase (CE), with a particular interest in studying the influence of different hard segment structures and their contribution to sensitizing the polymer towards enzyme catalyzed hydrolysis.(More)
After almost half a century of use in the health field, polyurethanes (PUs) remain one of the most popular group of biomaterials applied for medical devices. Their popularity has been sustained as a direct result of their segmented block copolymeric character, which endows them with a wide range of versatility in terms of tailoring their physical(More)
UNLABELLED We performed an in vitro examination of the inotropic effect of oxytocin, chlorobutanol, and their combination to assess the effect of these drugs on the contractile force of human atrial trabeculae. Right atrial tissue samples were obtained during cardiac surgery with cardiopulmonary bypass. Trabeculae of the atrial appendage were dissected and(More)
In order to impart flexibility, plastic medical devices incorporate liquid plasticizers into their structure. Data from several laboratories, including ours, have shown that these compounds leach from blood bags and tubing during collection of blood, storage of various blood components and during kidney dialysis and cell and plasma apheresis procedures.(More)
Enzyme-induced liberation of hard-segment-containing components from polyurethanes was evaluated using two 14C-labeled polyurethanes. A polyester urea-urethane and polyether urea-urethane were synthesized from toluene-2,4-diisocyanate (TDI)/polycaprolactone diol (PCL) or TDI/polyethylene glycol (PEO) with 14C-labeled ethylene diamine. Both materials were(More)
A cytoplasmic beta-glucosidase has been isolated and purified 9,000-fold to homogeneity from the liver of a case of type 1 Gaucher's disease to a specific activity of 400,000 nmol/h/mg of protein. Although markedly elevated above control levels in this case of adult Gaucher's disease, the activity of this cytosolic liver enzyme was found to be markedly(More)
Numerous solutions have been advocated for the preservation of donor hearts, and there has been much interest in universal and intracellular preservation solutions. This study compared the effects of Euro-Collins, University of Wisconsin, and Bretschneider's solutions with the use of an in vitro human right atrial muscle preparation to assess recovery of(More)
Phospholipase A(2) (PLA(2)) enzymes participate in a potent inflammatory pathway through the liberation of arachidonic acid upon hydrolysis of membrane glycerophospholipids. The presence of implanted polycarbonate-urethane (PCNU) materials, used in several medical applications, has the ability to influence inflammatory responses of human macrophages that(More)