Serum Concentration of Growth Factors in Dogs under Different Conditions of Distraction Osteogenesis.

Concentrations of insulin-like growth factors 1 and 2 (IGF-1 and IGF-2), stem cell factor (SCF), vascular endothelial growth factor (VEGF), and transforming growth factor ß1 (TGF-ß1) were measured in the blood serum of dogs subjected to experimental lengthening of shin bones. In animals subjected to shin bone lengthening at a rate of 1 mm/day in 4 steps, the concentrations of SCF and TGF-ß1 significantly increased in the middle of distraction and IGF-1 concentration increased by the end of distraction. In animals subjected to lengthening at a rate of 1.5 mm/day in 6 steps, the levels of IGF-1 and TGF-ß1 significantly increased in the middle of distraction and the concentration of IGF-2 at the end of distraction. In animals subjected to lengthening at a rate of 3 mm/day in 120 steps, the concentrations of IGF-1 and TGF-ß1 significantly decreased in the middle of distraction and concentrations of IGF-1, VEGF, and TGF-ß1 increased by the end of distraction.

[Lipid peroxidation in the rat liver following skeletal injury].

We assessed the concentrations of the products of lipid peroxidation (conjugated dienes--CD, malone dialdegide--MDA), the activity of catalase and the total lipids in the rat liver following tibial fractures. The experiment was carried out using sixty adult male Wistar rats. In group 1 (n = 30), tibial fractures were modeled and fixed with the apparatus of external fixation. In control group 2 (n = 30), the external apparatus was applied to the tibias but the fractures were not modeled. In group 1 animals, the absolute concentrations of CD and MDA were statistically reduced at each time-point studied. The concentration of CD in group 2 was significantly lower on day 3 while the level of MDA up to day 14 of the experiment than in the intact rats. The level of total lipids on days 3 and 7 was decreased in group 1 while in group 2 it was lower than the intact values on days 3 through 14. The catalase activity in group 1 was statistically elevated from day 7 of the experiment as compared to the intact rats. No significant changes in the activity of catalase were found in group 2 at all time-points of the experiment.

Effects of composition of biocomposite materials implanted into hole defects of the metaphysis on the reparative regeneration and mineralization of bone tissue.

We carried out a comparative analysis of morphological pattern and element composition of regenerated bone tissue forming in the metaphysis defects after substitution of these defects with calcium phosphate substance containing low-molecular non-collagen bone proteins with various affinities to ion exchangers. We have found that regenerated tissue in the defects grew from the edges to the center and its element composition depended on the maturity of newly formed bone tissue. Implantation material containing non-collagen bone proteins with various affinities to ion exchangers induced no significant changes in the content of analyzed elements of bone tissue around the defect. The content of analyzed elements in the areas distant from the defect area did not change during the experiment.