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PURPOSE: To describe a new drilling system that allows the surgeon to obtain autologous living bone that, when associated with a plasma rich in growth factors (PRGF), can be used in bone grafting. MATERIALS AND METHODS: Bone particles collected using both conventional and new drilling systems were analyzed by means of optic and electronic microscopy in 10 patients. Blood was collected from 43 volunteers and used to prepare PRGF. Quantitative aspects of the PRGF, including number of platelets and concentration of growth factors (insulin growth factor [IGF-I], transforming growth factor [TGF-beta1], platelet-derived growth factor [PDGF-AB], vascular endothelial growth factor [VEGF], hepatocyte growth factor [HGF], and epidermal growth factor [EGF]) were assessed. A demonstrative case study was presented. RESULTS: Microscopic examination showed that the bone structure and the presence of living cells in the bone chips were conserved in all samples obtained from drilling at low speed, whereas material obtained by conventional drilling did not maintain these qualities. Mean counts for TGF-beta1 (55.27 +/- 16.23 ng/mL), PDGF-AB (27.96 +/- 12.13 ng/mL), VEGF (421.09 +/- 399.0 pg/mL), EGF (455.49 +/- 210.04 pg/mL), and HGF (605.70 +/- 269.20 pg/mL) were significantly correlated with the number of platelets (590,000 +/- 197,000 platelets/microL; P < .05). DISCUSSION AND CONCLUSION: The new drilling procedure was developed based on biologic criteria. The method may reduce damage to the host tissue and can be used to obtain a mass of living bone for subsequent grafting in association with autologous growth factors. This new procedure may present new possibilities for enhanced bone healing and needs to be evaluated in a clinical trial. [ABSTRACT FROM AUTHOR]

Dental implantology is still an expanding field of scientific study because of the number of people that receive dental therapies throughout their lives worldwide. Recovery times associated to dental surgery are still long and demand strategies to improve integration of metallic devices with hard tissues. In this work, an in vitro ceramic coating is proposed to improve and accelerate osseointegration of titanium surfaces conceived to be used as dental implants or hip or knee prosthesis, shaped either as dishes or screws. Such coating consists of hydroxyapatite microdomains on the implant surfaces obtained in vitro by immersion of titanium alloy samples (Ti6Al4V) in a simulated body fluid. This titanium alloy is highly used in implant dentistry and trauma surgery, among other fields. Once the immersion times under physiological conditions yielding to different ceramic topographies on this alloy were set, the acellular coating time of major interest so as to optimize its biological development was determined. For this purpose, dental pulp mesenchymal cells were cultured on titanium coated surfaces with different hydroxyapatite outline, and cell adhesion, proliferation and morphology were followed through histological techniques and scanning electron microscopy. It was found that 4 days of acellular hydroxyapatite coating led to a significant cell adhesion on the titanium alloys at an early stage (6 h). Cells tended although to detach from the surface of the coating over time, but those adhered on domains of intricated topography or hydroxyapatite cauliflowers proliferated on them, leading to isolated large cell clusters. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2723-2729, 2016. [ABSTRACT FROM AUTHOR]

The aim of this study was to develop a biocompatible monolayer substrate based on fibrin and chitosan for in vitro culture of chondrocytes. Fibrin-chitosan composite substrates combined the proved cell adhesion properties of fibrin with the hydrophilicity and poor adhesion capacity of chitosan. Chitosan microspheres were produced by coacervation method, agglomerated within a fibrin network and subsequently crosslinked with genipin. The composite substrate was stable for 28 days of culture due to the high crosslinking density. Human chondrocytes cultured on the composite substrate were viable during the culture period. At the end of culture time (28 days) the composite substrate showed low cellular proliferation, 41% more collagen type II and 13% more production of sulfated glycosaminoglycans with respect to the amounts found at 14 days. The study revealed that dedifferentiated chondrocytes cultured in monolayer on the composite substrate can re-acquire characteristics of differentiated cells without using three-dimensional substrates or chondrogenic media. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013. [ABSTRACT FROM AUTHOR]

During hyposensitization therapy with aluminium-precipitated antigen solutions, a small % of patients develop persistent subcutaneous nodules at the injection site; the existence of delayed sensitivity to aluminium has been implicated in the pathogenesis of these nodules. We studied the prevalence of aluminium sensitivity (using patch, prick and intradermal tests) and common contact allergens (TRUE Test™) in 20 healthy subjects, and in 40 patients treated with aluminium- containing extracts, 20 of whom had persistent subcutaneous nodules that remained for more than 2 months, the other half having no nodular reactions or nodules that remained for less than 2 months. Aluminium sensitivity was found only in those patients of the treated group who had persistent nodular reactions, 4 cases of positivity to an aluminium chloride patch test being found. All 4 cases were women, nodules remained for more than 6 months, and intracutaneous tests were negative. 3 of them also had contact sensitivity to nickel. In 2 cases, nodules were removed for histological and histochemical examination, showing non-specific inflammatory granulomas, and aluminium crystals being found in only 1 case. It is concluded that delayed sensitivity to aluminium appears to be implicated in the pathogenesis of persistent nodular reactions, but sensitivity to aluminium was not found in patients treated with aluminium-precipitated extracts without persistent nodular reactions. [ABSTRACT FROM AUTHOR]

Small cell sarcomas of bone are difficult to classify and diagnose. The present case deals with such a tumor in which the original biopsy and the resected specimen, studied by histology before chemotherapy, provided no final information about its real nature. Thus several techniques were applied to discern its histogenesis and biology. Myogenin proved positive in isolated cells of the primary neoplasm but was extensively expressed in nude mice xenografts. Electron microscopy confirmed the existence of myofilaments. The cytogenetic analysis revealed a large number of chromosomal abnormalities, but not those found in the Ewing's/PNET (peripheral neuroectodermal tumor) family of tumors. This was confirmed by polymerase chain reaction (RT-PCR) wherein no EWS/Fli 1 or PAX3/FKHR gene rearrangements were detected. Based upon these studies, a rhabdomyosarcoma of bone was diagnosed. Clinically the neoplasm showed a highly aggressive behavior, causing death of the patient within 2 years after diagnosis. [ABSTRACT FROM AUTHOR]