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.

[Cosmetic results of posttraumatic eyeball subatrophy surgical treatment using "alloplant" biomaterials with subsequent use of prostheses]. / Kosmeticheskie rezul'taty khirurgicheskogo lecheniia posttravmaticheskoi subatrofii glaznogo iabloka s primeneniem biomaterialov "alloplant" i s polseduiushchim protezirovaniem.

A complex of surgical operations making use of Alloplant biomaterials, performed in 47 patients with initial posttraumatic subatrophy and 79 patients with well-developed and far advanced stages of this condition, helped preserve the eye as anatomical organ in 97.5% patients, with enlargement of the eyeball in two-thirds of patients and stabilization in one-third. Optic reconstructive operations were later performed and visual acuity improved in patients with the initial stage of subatrophy. Use of allotransplant for eyeball bandage in order to create a carcass for the sclera helped conceal the cicatricial deformation of the sclera and repair the shape and volume of the eyeball in patients with initial subatrophy, due to which a good cosmetic result was attained. In well-developed and far advanced subatrophy use of biomaterial for bandage created optimal conditions for thin-wall cosmetic prostheses, ruled out the irritating effect of the prosthesis in cases when corneal sensitivity was retained and/or there were coarse corneaoscleral cicatrices, and thus extended the indications for cosmetic prostheses of subatrophic eyes.

[Effects of repeated courses of electrostimulation and psychophysiologic correction on visual system characteristics in patients with poor vision of different genesis]. / Vliianie povtornykh kursov élektrostimuliatsii i psikhofiziologicheskoi korrektsii na kharakteristiki zritel'noi sistemy pri slabovidenii raznoi étiologii.

The effect of 5 courses of transcutaneous electrostimulation and of a combination of electrostimulation and psychophysiological correction of vision on the visual functions is assessed in 47 patients (90 eyes) with poor sigh of different genesis. Courses of 8-10-days were administered twice a year for 2.5-3 years. Cluster analysis of 13 objective and subjective parameters of vision permitted singling out patients responding to treatment well and poorly (groups 1 and 2). The absolute and differential electric activities of the central retina were increased during and between the courses in the first group while in the second group the shifts in the retina were negligible. Retinal changes are believed to reflect the general processes of adjustment of its activity to the levels needed for maintaining the integral visual functions, increased during treatment.

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.

Human lamellar tendon graft in corneal surgery.

BACKGROUND: Due to the lack of donor corneas or unsuitable conditions for keratoplasty because of preexisting conditions such as vascularization, infections, and multiple rejections, scientists have searched for new synthetic and biological materials that can temporarily or permanently substitute for corneal tissue. The purpose of this article is to show our personal experiences with the use of commercially available donor tendon tissue which has been chemically treated and was developed by Muldashev. METHODS: Ten eyes unsuitable for a corneal allograft underwent lamellar keratoplasty using tendon allografts. Due to differing pathologies various surgical procedures were used. The follow-up period ranged from 6 to 18 months. RESULTS: Transparent or semitransparent corneas resulted in seven of the ten eyes. In the three remaining eyes, conditions were improved for future penetrating keratoplasty because there was a significant decrease in corneal vascularization. The donor tendon was not rejected in any case. CONCLUSIONS: As an alternative therapeutic method, treated human tendon proved effective as donor material for lamellar keratoplasty.

[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.