The application of Bonelike® Poro as a synthetic bone substitute for the management of critical-sized bone defects - A comparative approach to the autograft technique - A preliminary study.

The effective treatment of non-unions and critical-sized defects remains a challenge in the orthopedic field. From a tissue engineering perspective, this issue can be addressed through the application bioactive matrixes to support bone regeneration, such as Bonelike®, as opposed to the widespread autologous grafting technique. An improved formulation of Bonelike® Poro, was assessed as a synthetic bone substitute in an ovine model for critical-sized bone defects. Bone regeneration was assessed after 5 months of recovery through macro and microscopic analysis of the healing features of the defect sites. Both the application of natural bone graft or Bonelike® Poro resulted in bridging of the defects margins. Untreated defect remained as fibrous non-unions at the end of the study period. The characteristics of the newly formed bone and its integration with the host tissue were assessed through histomorphometric and histological analysis, which demonstrated Bonelike® Poro to result in improved healing of the defects. The group treated with synthetic biomaterial presented bone bridges of increased thickness and bone features that more closely resembled the native spongeous and cortical bone. The application of Bonelike® Poro enabled the regeneration of critical-sized lesions and performed comparably to the autograph technique, validating its octeoconductive and osteointegrative potential for clinical application as a therapeutic strategy in human and veterinary orthopedics.

Dental pulp stem cells and Bonelike® for bone regeneration in ovine model.

Development of synthetic bone substitutes has arisen as a major research interest in the need to find an alternative to autologous bone grafts. Using an ovine model, the present pre-clinical study presents a synthetic bone graft (Bonelike®) in combination with a cellular system as an alternative for the regeneration of non-critical defects. The association of biomaterials and cell-based therapies is a promising strategy for bone tissue engineering. Mesenchymal stem cells (MSCs) from human dental pulp have demonstrated both in vitro and in vivo to interact with diverse biomaterial systems and promote mineral deposition, aiming at the reconstruction of osseous defects. Moreover, these cells can be found and isolated from many species. Non-critical bone defects were treated with Bonelike® with or without MSCs obtained from the human dental pulp. Results showed that Bonelike® and MSCs treated defects showed improved bone regeneration compared with the defects treated with Bonelike® alone. Also, it was observed that the biomaterial matrix was reabsorbed and gradually replaced by new bone during the healing process. We therefore propose this combination as an efficient binomial strategy that promotes bone growth and vascularization in non-critical bone defects.

Sacrococcygeal chordoma in a 9-year-old boy.

A case of sacrococcygeal chordoma in a 9-year-old boy is presented. The symptoms at presentation were pain in both legs and sacrococcygeal region for the last two years that increased in the last four weeks irradiating mainly to the left leg. X-ray and CT scan examinations of the lumbar region revealed an expansive process in the coccygeal region with multiple calcifications and a partially eroded coccyx. There was no invasion of the retroperitoneum and regional lymph nodes. A biopsy was performed and showed cords and nests of cells with large cytoplasm, sometimes vacuolated, nuclei with moderate pleomorphism and clumped chromatin. Immunohistochemistry with avidin-biotin peroxidase technique showed positivity for CK, S-100 protein, CEA, vimentin and to EMA. Chordomas are a distinctly uncommon neoplasm in the first two decades of life, specially in the sacrococcygeal region. They have an aggressive behavior. Treatment of choice is complete resection.

[The use of acetylsalicylic acid as a platelet antiaggregant]. / Uso do acido acetil salicílico como antiagregante plaquetário.

PURPOSE: To comprove the efficiency of acetyl salicylic acid (ASA) as platelet antiaggregant drug, a 100 mg/day dose base. METHODS: Two hundred and fifty-eight patients were studied between 1988 and 1990. Platelet functions were measured using an aggregometer plus ADP 5 as platelet aggregation inductor. RESULTS: Two groups were studied: 1st group, using ASA (111 patients), 91 hypoaggregants; 2nd group, not using ASA (147 patients), 120 normals, 12 hypoaggregants and 15 hyperaggregants. From the 2nd group, 91 had another evaluation under the use of ASA and showed a clear effect of the drug. CONCLUSION: The use of aspirin, 100 mg/day dose, is enough to reduce platelet antiaggregation.