Abstract: The invention relates to a process for manufacturing organized collagen structures, particularly of human origin and the organized collagen structures corresponding thereto. These organized structures may be either fibres or membranes. According to the process, a specimen of animal or human tissue is ground in a saline solution after washing and aseptization, in order to solubilize the collagen contained in said specimen. There is then added to the extract thus obtained, which is composed of a minimum quantity of collagen fibrils and which is free of non-fibrillary collagen precipitate, a catalyst promoting the reconstitution of collagen fibres. Following a maturation process, the reconstituted organized structures are separated from the aqueous medium by centrifuging, and are then washed, aseptized, conditioned, lyophilized and sterilized.

Abstract: The invention relates to a process for preparing antigen fractions designed for the detection of antibodies, the presence of which, in a certain quantity, in the human blood serum correlates with a cardiovascular risk condition. An arterial tissue is ground, freed of lipids and is subjected to the action of at least one agent selected from the group formed by an aqueous solution of an alkali metal salt or of an alkaline-earth metal salt at ambient temperature, of a hot acid of urea, of guanidine and proteolytic enzymes. The invention also relates to antigen fractions thus obtained and their utilization in the diagnosis of a cardio-vascular risk condition by counter-current electrophoresis or by an ELIFA test or an ELISA test.