RESUMEN
The aim is to study the features of the influence of local ultraviolet radiation on the organization and structure of collagen fibers in the radiation area. The studies were performed on 30 albino guinea pigs weighing 400-500 g, exposed to local ultraviolet radiation. Animals were removed from the experiment after 2 hours, 4 hours, 3 days, 8 days after irradiation. The control group was intact guinea pigs. To assess the structure and location of collagen fibers, skin sections in the irradiated area were studied using histological methods with polarized light analysis of collagen, and they were also analyzed using a scoring system for three parameters: composition, refraction intensity, and orientation of collagen fibers. The revealed structural features of collagen fibers reflect the course of the process of degeneration of the collagen skeleton of the dermis with a violation of the orientation and ordering of collagen fibers and an increase in the content of type III collagen with an increase in the observation period. According to the results of a semi-quantitative assessment of the state of collagen fibers, a significant deterioration in their structure and composition was recorded starting from 4 hours after exposure to ultraviolet radiation and progressed with an increase in the observation period. On the 8th day, the maximum deviation from the structure of the normal dermis is determined by the total number of points. The influence of local ultraviolet radiation in the minimum erythema dose on the skin of guinea pigs leads to the development of disturbances of the organization (abnormal position and ordering) and structure (increase in collagen content of type III) of collagen fibers of the dermis, which progress with an increase of the observation period.
Asunto(s)
Piel , Rayos Ultravioleta , Animales , Colágeno , Dermis , CobayasRESUMEN
This study investigated a person with an AB0 discrepancy. Her blood group initially typed at the birth as AB Rh+ (positive); however, it was B Rh+ (positive) or Rh- (negative) when she was in her teens. At room temperature, her erythrocytes were agglutinated by anti-B, and the agglutination was significantly weaker at 37 ºC. As a result, her erythrocytes did not absorb anti-B but anti-A. Furthermore, her erythrocytes were agglutinated by anti-A at 37 ºC with signs of hemolysis in the presence of complement. The unwashed erythrocytes were also agglutinated in an antiglobulin test by polyclonal anti-A at 37 ºC and by heated polyclonal anti-A and anti-A MAB 2-8 at room temperature. Moreover, her serum agglutinated A erythrocytes at room temperature with less activity at 37 ºC; however, it agglutinated B erythrocytes at 37 ºC. The ability of the erythrocytes of this person to absorb anti-A came along with the agglutination of her erythrocytes at 37 ºC by polyclonal serum and decreased activity of the serum to agglutinate A erythrocytes at 37 ºC, compared to room temperature. The absence of anti-B absorbance by the person’s erythrocytes was accompanied by the presence of anti-B in the serum, which was active at 37 ºC. The incubation of the person’s serum with 0 erythrocytes induced the ability of erythrocytes to absorb anti-A and to be hemolyzed by anti-A in the presence of complement in accordance with the person’s characteristics of erythrocytes. The reaction of absorption and agglutination at room temperature and 37 ºC by heated serum with the use of complement may help to reveal both weak A and B antigens and anti-A and anti-B antibodies while AB0 blood typing.
Asunto(s)
Eritrocitos/inmunología , Sistema del Grupo Sanguíneo Rh-Hr/inmunología , Aglutinación/inmunología , Tipificación y Pruebas Cruzadas Sanguíneas , Proteínas del Sistema Complemento/inmunología , Prueba de Coombs , Femenino , HumanosRESUMEN
The aim is to study the bone response to the implantation of two glass-ceramic materials into the distal metaphysis of the femur of rats. Experiment was carried out on 30 white 4-month-old laboratory male rats. Animals were randomly divided into two groups for the implantation of two types of calcium silicate-phosphate glasses (BS-11 or ASZ-5) into the defect of femur. Histology analysis was performed 7, 14 and 30 days (n=5 in each group) after the surgery. Estimate of bone-to-implant area (BIC%), fibrous-tissue-to-implant area (FIC%) and collagen distribution in polarization light was performed. 7daysafterimplantationthe fibrous tissue and new-formed woven bone tissue were found around BS-11 and ASZ-5. After 7daysFIC% was greater than BIC%: in BS-11 group by 2.2 times (p<0.001) and in ASZ-5 group by 2.5 times (Ñ<0.001). 14daysafterimplantation BIC% increased compared to 7 days: in BS-11 groupby 2.2 times (Ñ<0.001) and in ASZ-5 groupby 2.7 times (Ñ<0.001). After 30 days, the lamellar bone tissue was found around the implanted BS-11 and ASZ-5 (100% of the perimeter). ASZ-5 microparticles were embedded in the newly formed lamellar bone at 14 and 30 days after implantation. The collagen fibers were oriented parallel to the implants surface of BS-11 and ASZ-5. Glass-ceramic ASZ-5 and BS-11 materials have high biocompatibility, good osteoconductive and osteoinductive properties and are incorporated into the bone. However, the rapid degradation of ASZ-5 makes it fragile, which may become a limitation for its use in loaded areas of the skeleton.
Asunto(s)
Regeneración Ósea , Cerámica , Animales , Huesos , Fémur , Masculino , Prótesis e Implantes , Distribución Aleatoria , RatasRESUMEN
The aim is to study the characteristics of bone regeneration under the conditions of implantation of carbon/carbon composite material with and without pyrocarbon coating in the vertebral bodies of rat. C/c composite (n=9) or c/c composite & PC (n=9) were implanted into hole defects in the LIII vertebral bodies of white laboratory male rats (6-7 months, weight 250-350 g). The material was made in the form of a cylinder (diameter 2 mm, height 2 mm). Histological and histomorphometric study were performed at 15, 30 and 90 days after implantation. After 15 days, bone and granulation tissues were found in the ratio of ½ along the perimeter of both materials. After 30 days, fibroreticular bone tissue and connective tissue of varying degrees of maturity formed around the implants. The relative content of new formed bone tissue near the c/c composite after 30 and 90 days was 1.4 times lower (p<0.001) compared with the c/c composite and PC group. The studied materials are biocompatible, do not interfere with bone regeneration, and do not cause inflammatory reactions. Osseointegration qualities are higher for the c/c composite & pyrocarbon coated.
Asunto(s)
Vértebras Lumbares , Oseointegración , Animales , Huesos , Tejido Conectivo , Masculino , Prótesis e Implantes , RatasRESUMEN
Two kinds of calcium phosphate ceramic (CPC) granules of high porosity (50 +/- 5%) and improved (for such materials) compressive strength (10-25 MPa) consisted of hydroxyapatite (PHA) and a mixture of hydroxyapatite (HA) and beta-tricalcium phosphate (beta-TCP) in 60 HA/40 beta-TCP composition (PCPC) were developed. A comparative study of in vivo behavior of the materials implanted into an almost unloaded (greater trochanter of femur) and loaded (distal methaphysis of femur) zones in the skeleton of rabbits was performed. Significant activating influence of loading on the processes of new bone formation and reconstruction in macropores of both materials during all periods of implantation (up to 6 months) was observed. The role of relevant cells in the processes in the unsoluble PHA and the degradable PCPC (in which the processes was observed to intensify due to dissolution of the material) was studied and is discussed. Great disturbance in pore structure of the BCPC was revealed in more late periods of implantation. After 6 months, presence of large composite fragments located in intertrabecula spaces of greater trochanter was a characteristic feature of the PCPC crushing. The developed CPC materials seems to have good perspective for using in bone defect plasty in some loaded areas of the skeleton.