Abstract: High strength and modulus fibers are prepared from a poly(vinyl alcohol) solution in a mixed solvent consisting of water and water-miscible organic solvent. Upon extruding the poly(vinyl alcohol) solution into a coagulation bath, gel fibers are formed as a consequence of favorable gel structure with homogeneous net-works. Drawing the gel fibers to an exceedingly high degree leads to formation of poly(vinyl alcohol) fibers which have a superhigh tensile strength and a superhigh modulus.

Abstract: A highly blood-compatible material comprising a polymeric base material and water-soluble and substantially nonionic polymer(s) directly attached to the surface of the base material in an amount of 1 to 100 .mu.g/cm.sup.2. The polymeric base material is preferably in the form of a web and composed of polyurethane, ethylene/vinyl acetate copolymer or polyvinylchloride. In addition, the attached polymers may be selected from the group consisting of acrylamide polymers, polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, and dextran. This material is particularly useful for preparing vascular prosthesis of small diameters.

Abstract: A porous gel containing an immobilized enzyme is prepared by mixing an aqueous solution of polyvinyl alcohol having a saponification degree of not lower than 95 mol% and an average polymerization degree of not lower than 1,000, with an enzyme or enzyme-producing cell, and activated carbon powder, pouring the mixture into a container of any desired form, gelating and molding the mixture by dehydrating it up to a dehydration ratio of not lower than 50%, immersing the resulting molding in water, and drying the immersed molding. Preferably, dehydrating is by leaving the mixture to stand at room temperature or a temperature of from 30.degree. C. to 40.degree. C. The enzyme or enzyme-producing cell may be mixed with or adsorbed on an inorganic or organic carrier. The dried molding may be granulated.

Abstract: A porous and transparent hydrated gel is prepared from a poly(vinyl alcohol) solution in a mixed solvent consisting of water and an water-miscible organic solvent. Upon cooling the poly(vinyl alcohol) solution below room temperature, a gel is formed as a consequence of crystallization of poly(vinyl alcohol) molecules. Exchange of the organic solvent included in the gel with water produces a hydrated gel of poly(vinyl alcohol) which has a high tensile strength, a high water content, and a high light transmittance.

Abstract: An adhesion preventive for preventing adhesion between vital tissues is provided. The present adhesion preventive is a molded material consisting essentially of a biodegradable and absorbable polymer. It has an advantage of requiring no reoperation for its removal since it would be degraded and absorbed after completing its function in vivo.

Abstract: This invention provides a releasable balloon catheter having a portion cuttable by torsion or a portion cuttable by heating at or near a joint part between the catheter body and the balloon. When the balloon catheter is inserted into a vessel and carried to the desired site by the blood stream and the balloon is inflated by introducing a fluid into the balloon and is fixed at the desired site face-to-face with the wall of the vessel, torsion or heating causes the balloon to be released from the catheter body. The balloon catheter is used to embolize vascular lesions.

Abstract: This invention provides a releasable balloon catheter having a tube cuttable by torsion or a tube cuttable by heating at a joint part between the catheter body and the balloon. When the balloon catheter is inserted into a vessel and carried to the desired site by the blood stream and the balloon is inflated by introducing a fluid into the balloon and is fixed at the desired site face-to-face with the wall of the vessel, torsion or heating causes the balloon to be released from the catheter body. The balloon catheter is used to embolize vascular lesions.

Abstract: Disclosed is a balloon catheter including a catheter and a balloon bonded to the catheter through an adhesive in which the outer surface of the balloon is contiguous to the outer surface of the catheter through a smooth surface. In this balloon catheter, the balloon is tightly fixed to the catheter and there is no risk of separation of the balloon. Further, since the balloon catheter has a smooth surface in the connecting portion, insertion of the balloon catheter into a blood vessel and withdrawal of the balloon catheter from the blood vessel can be performed very easily and smoothly. Accordingly, this balloon catheter can be used very advantageously for the angiography.