Osteoconductivity of modified fluorcanasite glass-ceramics for bone tissue augmentation and repair

Modified fluorcanasite glasses were fabricated by either altering the molar ratios of Na 2O and CaO or by adding P 2O 5 to the parent stoichiometric glass compositions. Glasses were converted to glass-ceramics by a controlled two-stage heat treatment process. Rods (2 mm x 4 mm) were produced using the conventional lost-wax casting technique. Osteoconductive 45S5 bioglass was used as a reference material. Biocompatibility and osteoconductivity were investigated by implantation into healing defects (2 mm) in the midshaft of rabbit femora. Tissue response was investigated using conventional histology and scanning electron microscopy. Histological and histomorphometric evaluation of specimens after 12 weeks implantation showed significantly more bone contact with the surface of 45S5 bioglass implants when compared with other test materials. When the bone contact for each material was compared between experimental time points, the Glass-Ceramic 2 (CaO rich) group showed significant difference (p = 0.027) at 4 weeks, but no direct contact at 12 weeks. Histology and backscattered electron photomicrographs showed that modified fluorcanasite glass-ceramic implants had greater osteoconductivity than the parent stoichiometric composition. Of the new materials, fluorcanasite glass-ceramic implants modified by the addition of P 2O 5 showed the greatest stimulation of new mineralized bone tissue formation adjacent to the implants after 4 and 12 weeks implantation. © 2010 Wiley Periodicals, Inc.

Tissue composition and muscularity of lamb legs fed with sunflower seeds and vitamin E

The purpose of this study was to evaluate the tissue composition and carcass muscularity of 32 legs of Ile de France lambs fed with diets containing sunflower seeds and vitamin E, with mean body weight of 15 kg, lodged in individual pens at 15 kg and slaughtered at 32 kg of body weight. The treatments influenced (P<0,05) leg weight, femur length and muscle: bone ratio, being the highest values (2,13 kg, 16,19 cm and 7,38, respectively) in lambs that received diet without sunflower seeds and vitamin E. The other variables were not affected (P>0,05) by the treatments. The interaction of the sunflower and vitamin E was positive for bone total weights and intramuscular fat.

Physiologic values of broiler femurs at different growth phases using Bone densitometry and Bone Breaking Strength

The objective of this experiment was to determine the normal values of Bone Radiographic Density (BRD) by using the optical densitometry in radiographic images and the Bone Breaking Strength (BBS) of broiler femurs at different ages (8, 22 and 42 d of age). A total of 60 Cobb male broilers were distributed in three age groups of 20 birds. The BRD and the BBS (maxim force and rigidity) values increased (p<0.01) over the course of ages, presenting greater values at 42 d of age when comparing to 8 and 22 d of age, evidencing a biomechanical adaptation of femur to growth. This experiment offers results that can be used in other experiments of broilers fed with different nutritional levels and they can also be related to pathological values, allowing the diagnosis of diseases that affect the integrity of the poultry leg. © Asian Network for Scientific Information, 2011.

High-sucrose effect on bone structure, hardness and biomechanics in an obesity model using Wistar male rats

Introduction: Excessive consumption of sugar-sweetened beverage is positively related to overweight. Despite the epidemic of childhood obesity, body mass can have a positive or negative effect on bone health. Material and methods: Wistar rats 8 weeks olds were randomly assigned to consume water (Control group, n = 10), sucrose 30% (HS group, n = 10) and water + sucrose 30% (WHS group, n = 14) for 8 weeks. All animals received standard laboratory chow ad libitum. Femur measurements included microhardness, bone mineral density (BMD) by DXA, mechanical compression test and microcomputed tomography (microCT) analysis. Results: We observed significant difference in final body weight in HS and WHS groups, significant increase in triacylglycerol/fructosamine in HS and WHS groups, significantly high BMD in WHS group, increased periosteal/endosteal cortical microhardness in WHS group. Compared with control, microCT parameters evidenced lower amount of connected trabecular bone, decreased bone volume, lower trabecular number with high trabecular separation in distal epiphysis in WHS animals. Conclusion: High-sucrose consumption causes obesity induced by a liquid diet with negative effects on cancellous bone.

Tomographic index as auxiliary criteria for surgery indication in fracture dislocation of acetabulum posterior wall

There are situations which the tomographic exam is done on the affected hip or situations where the contralateral hip presents abnormalities that make it impossible to compare. In this study we aimed to evaluate a tomographic index that does not require comparison between the both hips. Twenty two patients with unilateral acetabular fracture dislocation with fracture of posterior wall were studied. We established the relationship between the remaining posterior wall and the femoral head diameter (head/wall index-H/W index). We evaluated 45 two-dimensional computed tomography scan in normal hips and established the H/W index. In 45 normal hips we simulated a posterior wall fracture with involvement of 25% and 30% of the posterior wall and calculated the H/W index. We divided into five groups with five different H/W index (fractured group with non surgical treatment; fractured group; normal group; normal group with simulated fracture of 25% and; 30% of the posterior wall). 2.4 was the lowest limit of confidence interval of the group with 25% of the posterior wall fracture. When we analyzed the confidence interval of the 30% fracture group the upper limit of the confidence interval was 2.7, close to the lower limit of the surgical group that was 2.9. Thus, we suggest the 2.4 the H/W index limit as an auxiliary criteria to indicate whether or not to operate. H/W index is helpful to decide whether or not surgery indication in the fracture dislocation of the posterior wall of the acetabulum. © 2012 Fujiki et al.; licensee BioMed Central Ltd.

Detecting early biomechanical effects of zoledronic acid on femurs of osteoporotic female rats

Aim. To investigate the biomechanical effects of zoledronic acid (ZA) on femurs of female osteoporotic rats after follow-up periods of 9 and 12 months. Methods. Eighty female Wistar rats were prospectively assessed. At 60 days of age, the animals were randomly divided into two groups: bilateral oophorectomy (O) (n=40) and sham surgery (S) (n=40). At 90 days of age, groups O and S were randomly subdivided into four groups, according to whether 0.1 mg/kg of ZA or distilled water (DW) was intraperitoneally administered: OZA (n=20), ODW (n=20), SZA (n=20), and SDW (n=20). The animals were sacrificed at 9 and 12 months after the administration of the substances, and then their right femurs were removed and analyzed biomechanically. Axial compression tests that focused on determining the maximum load (N), yield point (N), and stiffness coefficient (N/mm) of the proximal femur were performed in the biomechanical study. Results. ZA significantly increased the maximum load and yield point, reducing the stiffness coefficient concerning the oophorectomy status and follow-up period. Conclusion. Zoledronic acid, at a dose of 0.1 mg/kg, significantly increased the maximum loads and yield points and reduced the stiffness coefficients in the femurs of female rats with osteoporosis caused by bilateral oophorectomy. © 2012 Evandro Pereira Palacio et al.

Serum Metalloproteinases 2 and 9 as Predictors of Gait Status, Pressure Ulcer and Mortality after Hip Fracture

Introduction: The aim of this study is to evaluate the serum activity of metalloproteinases (MMPs) -2 and -9 as predictors of pressure ulcer (PU), gait status and mortality 6 months after hip fracture. Methods: Eighty-seven patients over the age of 65 admitted to the orthopedic unit from January to December 2010 with hip fracture were prospectively evaluated. Upon admission, patient demographic information, including age, gender and concomitant diseases, was recorded. Blood samples were taken for analysis of MMP -2 and -9 activity by gel zymography and for biochemical examination within the first 72 hours of the patient's admission, after clinical stabilization. The fracture pattern (neck, trochanteric or subtrochanteric), time from admission to surgery, surgery duration and length of hospital stay were also recorded. Results: Two patients were excluded due to the presence of pathological fractures (related to cancer), and three patients were excluded due to the presence of PU before admission. Eighty-two patients, with a mean age of 80.4 ± 7.3 years, were included in the analysis. Among these patients, 75.6% were female, 59.8% had PU, and 13.4% died 6 months after hip fracture. All patients underwent hip fracture repair. In a univariate analysis, there were no differences in serum MMP activity between hip fracture patients with or without PU. In addition, the multiple logistic regression analysis models, which were adjusted by age, gender, length of hospital stay and C-reactive protein, showed that the pro-MMP-9 complexed with neutrophil gelatinase-associated lipocalin form (130 kDa) was associated with gait status recovery 6 months after hip fracture. Conclusions: In conclusion, serum pro-MMP-9 is a predictor of gait status recovery 6 months after hip fracture. © 2013 Gumieiro et al.

Histological analysis of the osseointegration of Ti-30Ta dental implants after surface treatment

Metallic biomaterials are used to reinforce or to restore the form and function of hard tissues. Implants and prosthesis are used to replace shoulders, knees, hips and teeth. When these materials are inserted in bone several biological reactions happen. This process can be associated to surface properties (topography, roughness and surface energy). In this work, the influence of biomimetic surface treatment in the osseointegration of Ti-30Ta dental implants was evaluated. Ingots were obtained from titanium and tantalum by using an arc-melting furnace. They were submitted to heat treatment at 1,100°C for 1 h, cooled in water and cold worked by swaging. Then, screw-shaped implants (2.0 mm diameter by 2.5 mm length) were manufactured and they were implanted in a rat's femur. Animals were divided into two groups: untreated (control group) and treated (biomimetic surface treatment). They were sacrificed 30 days after implantation. For histological analysis, implants with surrounding tissue were removed and immersed in formaldehyde. Samples were embedded in polymethyl methacrylate and after polymerization, cut with a saw, polished and mounted on glass slides. The results obtained suggest that biomimetic surface treatment was able to promote an increase osseointegration on the surface of dental implants. © Springer-Verlag Berlin Heidelberg 2013.

Pseudoautotomy in Dendrophidion dendrophis and Mastigodryas bifossatus (Serpentes: Colubridae): Tail Morphology and breakage frequency

The micro and macro structures of the caudal vertebrae and muscles of Dendrophidion dendrophis and Mastigodryas bifossatus were described using histological slides, dissections, radiographs, and clearing and double staining of intact, broken, and healed tails. To analyze the relationship among the frequencies of healed tails we established two populations of D. dendrophis and six groups of M. bifossatus. We found that fractures of the tail in the two species are intervertebral, and there are no morphological and/or structural mechanisms that facilitate the urotomy, which is classified as non-specialized pseudoautotomy. The caudal vertebrae of D. dendrophis and M. bifossatus show minor differences in the shape of the condyle, cotyle, and border of the neural spine, and in the size and orientation of the hemapophysis and pleurapophysis. The absence of bleeding at the moment of tail breakage may indicate the presence of sphincters in the veins and arteries of D. dendrophis. The distal part of the last vertebrae retained in healed tails of D. dendrophis and M. bifossatus participates in the healing processes as a possible source of calcium in the formation of a calcified cap. We found high frequency of tail breakage in both species, which occurs in almost the entire length of the tail, with no specific areas of concentration. There was no difference in the frequencies of healed tails among males and females of different populations of D. dendrophis and M. bifossatus. Juveniles have lower breakage frequencies than adults in both species, except for populations of M. bifossatus from the Cerrado and Pampa. © 2013 by the American Society of Ichthyologists and Herpetologists.

Osteogenesis-inducing calcium phosphate nanoparticle precursors applied to titanium surfaces

This study investigated the effects of the morphology and physicochemical properties of calcium phosphate (CaP) nanoparticles on osteogenesis. Two types of CaP nanoparticles were compared, namely amorphous calcium phosphate (ACP) nano-spheres (diameter: 9-13 nm) and poorly crystalline apatite (PCA) nano-needles (30-50 nm x 2-4 nm) that closely resemble bone apatite. CaP particles were spin-coated onto titanium discs and implants; they were evaluated in cultured mouse calvarial osteoblasts, as well as after implantation in rabbit femurs. A significant dependence of CaP coatings was observed in osteoblast-related gene expression (Runx2, Col1a1 and Spp1). Specifically, the PCA group presented an up-regulation of the osteospecific genes, while the ACP group suppressed the Runx2 and Col1a1 expression when compared to blank titanium substrates. Both the ACP and PCA groups presented a more than three-fold increase of calcium deposition, as suggested by Alizarin red staining. The removal torque results implied a slight tendency in favour of the PCA group. Different forms of CaP nanostructures presented different biologic differences; the obtained information can be used to optimize surface coatings on biomaterials. © 2013 IOP Publishing Ltd.

High condylectomy procedure: A valuable resource for surgical management of the mandibular condylar hyperplasia

Condylar hyperplasia is an overdevelopment of the condyle, which may manifest unilaterally or bilaterally. This pathological condition can lead to facial asymmetry, malocclusion, and dysfunction of the temporomandibular joint. The etiology and pathogenesis of condylar hyperplasia remain uncertain, but it has been suggested that its etiology may be associated with hormonal factors, trauma, and hereditary hypervascularity, affecting both genders. The diagnosis is made by clinical examination, and radiological imaging, and additionally, bone scintigraphy, is a fundamental resource for determining whether the affected condyle shows active growth. Patients with active condylar hyperplasia management have better results when they are subjected to the high condylectomy procedure. The authors report a case in a 20-year-old female subject with unilateral active condylar hyperplasia who was treated by high condylectomy. The patient has been followed up for 4 years without signs of recurrence and with good functional stability of the occlusion. © 2013 by Mutaz B. Habal, MD.

Uranium deposition in bones of wistar rats associated with skeleton development

Sixty female Wistar rats were submitted to a daily intake of ration doped with uranium from weaning to adulthood. Uranium in bone was quantified by the SSNTD (solid state nuclear track detection) technique, and bone mineral density (BMD) analysis performed. Uranium concentration as a function of age exhibited a sharp rise during the first week of the experiment and a drastic drop of 70% in the following weeks. Data interpretation indicates that uranium mimics calcium. Results from BMD suggest that radiation emitted by the incorporated Uranium could induce death of bone cells. © 2013 Elsevier Ltd.

Glicerina na alimentação de cordeiros 1/2 Dorper 1/2 Santa Inês: consumo, digestibilidade, desempenho, características quantitativas da carcaça e qualitativas da carne

Pós-graduação em Zootecnia - FCAV

Capacidade funcional, composição corporal e condições de saúde de idosos longevos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito do consumo de iogurte de soja suplementado com isoflavonas e cálcio sobre o tecido ósseo de ratas maduras ovariectomizadas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)