MORPHOLOGICAL FEATURES OF TUBULAR BONES REPARATIVE REGENERATION UNDER THE INFLUENCE OF ANTITUMOR CHEMOTHERAPEUTICS.

OBJECTIVE: The aim: Determination of morphological features of reparative regeneration of diaphysis defect of long tubular bones under the influence of antitumor chemotherapeutics in a model experiment. PATIENTS AND METHODS: Materials and methods: 96 white nonlinear rats after application of the perforated defect of the femur were administered the appropriate antitumor drug (doxorubicin, 5-fluorouracil, methotrexate) three times with an interval of 21 days. Morphological features of bone tissue formation and remodeling in the regenerate area were studied using histological and morphometric methods. RESULTS: Results: The inhibitory effect of antitumor chemotherapeutics on the formation of regenerate, expressed by slowing down the process of bone tissue differentiation was found. This is confirmed by a decrease in the area of reticulofibrous and lamellar bone tissue, chaotic arrangement and narrowing of bone trabeculae with uneven color, slow formation of bonding lines between the maternal bone and the regenerate. CONCLUSION: Conclusions: The revealed morphological features of reparative regeneration of the diaphysis defect of long tubular bones under the influence of antitumor chemotherapeutics doxorubicin, 5-fluorouracil and methotrexate in a model experiment indicate a slowing of reparative regeneration processes at all stages of recovery after injury.

STRUCTURE OF THE KNEE ARTICULAR CARTILAGE AFTER THE FEMUR AND TIBIA EXTRA-ARTICULAR INJURY.

OBJECTIVE: 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. PATIENTS AND METHODS: 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: 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: 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.

Improvement of Skeletal Muscle Regeneration by Platelet-Rich Plasma in Rats with Experimental Chronic Hyperglycemia.

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.