Herein, the structural effect of autologous platelet-rich plasma (PRP) on posttraumatic skeletal muscle regeneration in rats with chronic hyperglycemia (CH) was tested. 130 white laboratory male rats divided into four groups (I—control; II—rats with CH; III—rats with CH and PRP treatment; and IV—rats for CH confirmation) were used for the experiment. CH was simulated by streptozotocin and nicotinic acid administration. Triceps surae muscle injury was reproduced by transverse linear incision. Autologous PRP was used in order to correct the possible negative CH effect on skeletal muscle recovery. On the 28th day after the injury, the regenerating muscle fiber and blood vessel number in the CH+PRP group were higher than those in the CH rats. However, the connective tissue area in the CH group was larger than that in the CH+PRP animals. The amount of agranulocytes in the regenerating muscle of the CH rats was lower compared to that of the CH+PRP group. The histological analysis of skeletal muscle recovery in CH+PRP animals revealed more intensive neoangiogenesis compared to that in the CH group. Herewith, the massive connective tissue development and inflammation signs were observed within the skeletal muscle of CH rats. Obtained results suggest that streptozotocin-induced CH has a negative effect on posttraumatic skeletal muscle regeneration, contributing to massive connective tissue development. The autologous PRP injection promotes muscle recovery process in rats with CH, shifting it away from fibrosis toward the complete muscular organ repair.

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Aim: The non-functional overreaching requires a deeper study because its diagnosing is not based on conventional methods. Orthostatic and clinostatic tests make it easy and quick to detect health problems. The purpose of this research is defining orthostatic reactions among 68 athletes with and without signs of non-functional overreaching. Materials and Methods: Our research comprises 2 groups of 68 athletes subdivided by presence of non-functional overreaching. The first group includes 27 persons with vegetative disorder signs. The second group covers 41 individuals without non-functional overreaching. For all of them, we conducted orthostatic tests to record blood pressure and heart rate horizontally and vertically. Results: The research showed that 9 athletes (33.3% of the O+ group) had unsatisfactory results after body tests in horizontal and vertical positions. All athletes revealed the orthostatic tolerance disorder. For 5 sportsmen, the latter was accompanied by the clinostatic overreaction. Resting heart rate did not vary considerably between both groups (р=0.412). However, orthostatic tests reflected the sharp index rise among 9 individuals. For non-functional overreaching athletes, the mean value (р<0.001) exceeded the corresponding one in the O- group more than twofold. Conclusions: Although today it is possible to differentiate orthostatic-clinostatic tolerance from vegetative dysfunction, further research must be conducted to clarify this syndrome types and to improve physical recovery for non-functional overreaching athletes.

Introduction: There is a significant divergence of data on the rate of resorption and replacement by the bone tissue of osteoplastic materials based on β-tricalcium phosphate in cancellous bone. At the same time in literature missing morphometric and electron microscopic features of bone tissue of the regenerate of compact substance of bone in these conditions. This study was aimed at the assessment of the healing of compact bone tissue defect after implantation of osteoplastic material "Calc-i-oss  " with the definition of the dynamics of resorption and morphological characteristics of bone tissue of the regenerate. Material and Methods: In the middle third of the diaphysis of the femur of rats there was reproduced the perforated defect to the bone-brain channel that was filled with osteoplastic material "Calc-i-oss  ". After surgery the fragments of injured bones were studied at the 60th and 120th day by methods of light microscopy with morphometry and scanning electron microscopy. Results: The conducted research revealed no inflammatory reaction at the site of the defect, signs of necrobiosis and necrosis of osteocytes in adjacent to the site of implantation maternal bone. The site of defect was filled with lamellar bone tissue high in osteoblasts, osteocytes and with integrated into its structure remains of "Calc-i-oss  ". On the surface and inside the implant there were found osteogenic cells and bone foci. It was established that the osteoplastic material throughout the observation period is subjected to development and replacement by bone tissue of the regenerate, the ratio of which on the 60th day of the experiment was 25.72 ± 2.06% to 74.28 ± 2.06%, and on the 120th day -18.31 ± 1.54% to 81.69 ± 1.54%. Conclusion: Osteoplastic material "Calc-i-oss  " exhibits biocompatibility, osteoconductive properties, ability to resorption and is replaced by bone tissue, with which it integrates well.

The aim: To study the microscopic, ultramicroscopic, and histomorphometric features of the knee articular cartilage in rats with an extra-articular injury of the femur and tibia. Materials and methods: 60 white laboratory rats divided into three groups (I – control; II – animals with traumatic femur injury; III – animals with traumatic tibia injury) were used for the study. The light microscopy was performed by Olympus BH-2 microscope (Japan), transmission electron microscopy – by JEM-1230 microscope (Japan). SPSS software (version 17.0) was used for mathematical analysis. Results: The more pronounced morphological changes were observed in the articular cartilage of the proximal tibial epiphysis after mechanical tibial injury. The thickness of the articular cartilage was 27.89 % less than in the control. The chondrocyte number in the superficial zone was lower by 8.94 %, intermediate zone – by 14.23 %, and deep zone – by 21.83%, compared to control. Herewith, the histological changes were mostly detected in the intermediate and deep zones of the articular cartilage of both bones. Also, some chondrocytes had deformed nuclei, hypertrophied organelles, numerous inclusions, and residual glycogen granules. Conclusion: The extra-articular mechanical trauma of the lower limb bones leads to pathological changes in the knee articular cartilage. The structural changes include the articular cartilage thickening, the decrease in chondrocyte number, as well as chondrocyte rearrangement due to degenerative-dystrophic processes.