Histological Evaluation of the Effects of Growth Factors in a Fibrin Network on Bone Regeneration.

OBJECTIVE: The aim of this study was to evaluate the effect of mineralized plasmatic matrix (MPM), comprising a combination of synthetic graft and platelet concentrates, on bone regeneration. METHODS: Critical size defects of 6-mm diameter were created on the tibias of 6 male sheep, with the animals subsequently assigned into 2 groups. Of the 5 bone defects generated per animal, 4 were randomly filled with MPM, beta-tricalcium phosphate graft (ß-TCP), platelet-rich fibrin (PRF) + ß-TCP, and autogenous graft. One defect was left empty as a control group. Animals were killed at 3 weeks (early healing group) and 6 weeks (late healing group). The specimens underwent histologic and histomorphometric analysis to evaluate new bone formation. RESULTS: In both healing periods, new bone formation from autogenous bone was observed significantly more often than from biomaterials or the empty defect. The degree of new bone formation for MPM was significantly higher than that of the control group at all healing periods. In addition, it was significantly higher in both healing periods than that of ß-TCP albeit only in the late healing period than that of the PRF + ß-TCP combination. In all biomaterial groups, residual graft ratios decreased from early to late healing periods. CONCLUSION: The results indicated that MPM, representing growth factors in a fibrin network, increases new bone formation in surgically created defects in sheep tibia as confirmed by histologic assessment.

Meningoencephalitis caused by pathogenic Sarcocystis species in a naturally infected sheep in Turkey.

A 3-year-old sheep was examined after an acute onset of hind limb paralysis and ataxia. At necropsy, central nervous system, pulmonary and intestinal hyperaemia and ecchymoses in the aortic arch were observed. Main microscopic lesions were confined to the heart, cerebrum and cerebellum. There were a multifocal mild myocarditis and nonsuppurative meningoencephalitis together with protozoal cysts in the heart and the brain. Protozoal cystic structures were observed within many of the myocardial fibers as well as in the cerebrum and cerebellum. Using light microscopy it could not be morphologically determined whether these organisms were Toxoplasma (T.) gondii or Neospora (N.) caninum. Additional diagnostic methods like immunohistochemistry and polymerase chain reaction provided differentiation of Sarcocystis from T. gondii and N. caninum. Transmission electron microscopy demonstrated characteristic features of Sarcocystis sp. as previously described. This is the first confirmed diagnosis of Sarcocystis sp. in the central nervous system of a sheep from Turkey.