[The membrane allotransplantate use in surgery for hygroma].

Reparative processes in calcaneal tendon after the use of new repair technique were studied in two animal series. In both groups the calcaneal tendon was incised to the half of its width. In control group no further manipulations were performed and in the experimental group the defect was covered with allotransplantate of dura mater (membrane stop). The control group demonstrated less active tendon reaction, whereas the experimental group demonstrated stimulation of reparation with the rapid change of inflammatory stages. The membrane stop serves as a modeling frame for new fibers of the regenerate. The obtained results permit recommending the membrane stop in treatment of hand hygromas for the cover of weak tendon areas.

[Effect of radiation sterilization on biomaterial structure and properties].

The purpose of the investigation was the study of structural changes connective tissue biomaterials after different combinations of their radiation sterilization, physico-chemical treatment and conservation. Using a complex of histological methods (polarization microscopy of unstained sections, van Gieson's stain, scanning electron microscopy), an analysis was performed to detect the structural changes in tendons and dermis which underwent various physico-chemical treatment and subjected to the radiation sterilization using different types (3- radiation and fast-moving electron stream) and doses (1.5, 2.5 and 4 Mrad) of radiation. The dependence of the structural changes in the biomaterials on the fibroarchitectonics of the tissue as well as on the physico-chemical treatment and radiation type and dose was demonstrated. The tendons underwent clear-cut significant changes in all regimes and radiation doses studied. Dermis was found to be most resistant to radiation challenge.

The role of macrophages in the tissues regeneration stimulated by the biomaterials.

Allogenic grafted tissues are subjected to biodegradation and replaced by the regenerate. To minimize the immune response and improve the rebuilding of tissues there was developed a technology to treat tissues with a cells elimination and dosed out extraction of proteoglycanes (Alloplant. With aim to clarify the role of macrophages in the tissues regeneration resulting implantation the biomaterials 112 rats were injected the allogenic and xenogenic (rabbit's) pulverized biomaterials in the form of suspension. Injections were performed subcutaneously into the animals' back by the base of the tail. The control group (14 rats) were injected a physiologic saline. Animals were killed by ether inhalation on day 2, 4, 7, 14, 30, 90 and 180 and tissue sections were studied by light and electron microscopy. The study showed the key role of the macrophages in resorption of the allogenic biomaterial and formation of the newly-formed tissue. Implantation of the biomaterial induced activity a great number of the mature macrophages, which completely lysed and resorbed the biomaterial particles. Expression TNFalpha was significantly higher whereas expression TGF-beta1 was significantly lower. With xenogenic biomaterial implantation there were less macrophages, their activity was restricted. Macrophages containing large vacuoles with an active endo- and exocytosis were revealed in the allogenic biomaterial implantation and were named 'matrix-forming macrophages'. We may suppose that these macrophages synthesize (or re-synthesize) proteoglycan component of the newly-formed collagen fibers. There was put forward a hypothesis about the two component mechanism of the collagen fibers formation.

Basic research conducted on alloplant biomaterials.

PURPOSE: To reduce antigenicity of allografts and stimulate their replacement by natural recipient tissues. METHODS: Experimental allotransplantation of different tissues (fascias, tendons, derma, fat, etc.) with histological, histochemical, electron microscopical, electron histochemical examination 3, 5, 7, 14, 21, 30, 60, 120, 180 and 360 days postoperatively. RESULTS: Allografts of different tissues with glucosaminoglycans extracted from collagen fibers have low antigenicity and can be replaced by natural tissues. Allografts with these properties were named 'Alloplant'. CONCLUSIONS: Alloplant biomaterials can selectively stimulate natural tissue regeneration. Hence, Alloplant biomaterials can be utilized in surgery for the restoration of different tissues.

[Experimental bioplasty of tuberculous caverns of the lung]. / Bioplastika tuberkuleznykh kavern legkogo v éksperimente.

A possibility of using allontransplants of the "Alloplant" series for pulmonary cavernoplasty has been developed and substantiated experimentally. Histological studies of an experimental pulmonary cavern under conditions of allotransplantation revealed the dynamics of the morphological transformation typical of human pulmonary cavern healing. A reparative process results in the liquidation of the specific changes in the cavern wall followed by the formation of a regenerate in the form of a stellate cicatrix.