29 resultados para epiphysis
em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"
Resumo:
O objetivo do presente trabalho foi o de estudar a resistência à corrosão em placas de aço inoxidável 316L, com diferentes tipos de acabamento e tratamento superficial, e a possível interferência dessa reação corrosiva na consolidação óssea. Utilizaram-se placas semi-acabadas, polidas, tratadas com jatos de microesferas de vidro e passivadas, as quais foram aplicadas na epífise distal do rádio de cães. Foram utilizados 12 animais, divididos em dois grupos, nos quais, após osteotomia bilateral do rádio e ulna, foram realizadas osteossínteses do rádio, totalizando 24 procedimentos. Avaliou-se a evolução clínica e radiográfica das regiões que receberam os implantes aos 30, 60, 90, 180, 240 e 360 dias. Os animais do grupo 1 (GI) foram sacrificados aos 180 dias e os do GII aos 360 dias para estudo histológico e de microscopia eletrônica de varredura do local da osteotomia sob a região dos implantes metálicos e para estudo da resistência à corrosão no organismo, pelos implantes metálicos, por meio de análises química e metalográfica (microscopia óptica e eletrônica de varredura e espectroscopia de espalhamento de energia por raios X). Os animais recuperaram a função dos membros operados 24 horas após a cirurgia. Radiograficamente, verificou-se a consolidação óssea em todos os animais. Macro e microscopicamente não foram observados sinais de corrosão nos implantes metálicos, exceto em uma placa passivada, aplicada no rádio esquerdo de um animal, na qual a corrosão foi detectada pela microscopia óptica e eletrônica de varredura. Este estudo permite concluir que as placas de aço inoxidável 316L, independente do acabamento superficial a que foram submetidas, não sofreram corrosão ou reações adversas e foram efetivas no tratamento das fraturas experimentais do rádio e ulna de cães.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The aim of study was to investigate if different intake levels of concentrate (supplementation levels) would have an influence on chemical composition, biometric aspects and bone mineral density (BMD) of femurs from Moxoto growing goats in the Brazilian semiarid region. Thirty-two castrated kids (15.69 +/- 0.78 kg initial BW) were used allocated randomly to one of the four levels of supplementation (SL) (treatments groups: 0: 5; 10 and 15 g/kg BW). When the animals of treatment group 15 g/kg BW reached 25 kg BW, the animals in the others treatments groups were also slaughtered. The increase SL resulted in linear increase (P<0.001) in the performance of animals as well as in fresh and dry weight of the femur and decrease of relative weight of the femur. The dry matter contents (g/kg) of femur increased linearly, however, the amounts of MM, ether extract, Ca, P. Mg, Na and K were not affected by the treatments. The values found in this study ranged from 134.84 to 155.90g of Ca, 48.14 to 55.95g of P. 1.69 to 1.87g of Mg, 2.87 to 3.24g of Na and 1.42 to 1.61 g of K/kg of bone in natura for animals with smaller and higher slaughter weight, respectively. The biometric and densitometric variables increased linearly with increasing treatments, except for the thickness of the sponge layer of the proximal and distal epiphysis and BMD measured in the distal epiphysis. The supplementation with concentrate did not affect the chemical composition of the femur, although it has positively influenced the structure and the bone mineral density. A BMD estimated via radiographic bone aluminum equivalent did not have correspondence with bone mineral content measured chemically. (C) 2011 Elsevier BM. All rights reserved.
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Objectives: To determine the effects of ultrasound therapy on the femur and tibia growth in young rats. Method: Four-week-old male Ratus Norvegicus totaling 115 animals, divided into four groups, were submitted to ultrasound therapy (0.8 MHz, fixed tube head, continuous pulse, for 10 minutes, once a day, ten times) on the medial face of the right knee, with powers of 0.0 W/cm2 (group 31), 0.5 W/cm2 (group G2), 1.0 W/cm2 (group G3), and 1.5 W/cm2 (group G4). Histological slides of the epiphysis, growth plate and metaphysis and the femoral and tibial length measurements were studied in the sixth, thirteenth and twenty-sixth weeks of life. The data were submitted to factorial analysis of variance according to a one-way layout. Results: No statistically significant bone growth alteration was established between any of the three treated groups and the control group. However, alterations in femoral and tibial growth suggesting a decrease in G4 in relation to 02 and G3 were noted. In G4, histopathological alterations, such as cellular necrosis and post-necrosis bone neoformation were found. Conclusion: According to this study, no statistical evidence of bone growth stimulus or inhibition resulting from the application of ultrasound therapy was found when comparing the treated groups with the control group. Histological alterations regarded as pathological were only observed in G4. Also, smaller significant bone growth was found in G4 compared to G2 and G3. Level of Evidence: Level II, cross-sectional study.
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This study was carried out at Faculdade de Medicina Veterinária e Zootecnia, UNESP, Botucatu-SP, Brazil. The aim was to establish the normal values of bone mineral density (BMD) expressed in millimeters of aluminum in the tibia of broiler chickens using optical densitometry of radiographs. Four hundred Cobb male chicks were reared from 1 to 40 days of age, when 40 of them were selected and the right femur-tibia articulation was radiographed. Radiographs were taken with the X-ray equipment calibrated for 45 kvp and 3.2 mAs and a focus-to-film distance of 90 cm. An aluminum phantom ASTM-6063 consisting of 20 ladder steps with graduate density was placed parallel to the area to be radiographed and used as a densitometry reference standard. Radiograph images were analyzed using the software ATHENA - SIA. The proximal growth plate of the right tibia epiphysis was used as the standard reading region. The inclination axis of the reading window was 0 and the window was 10 mm high and 40-45 mm wide, depending on the bone size. Optical densitometry values of the radiographs ranged from 1.46 to 1.77 mmAl, and the coefficient of variation was 9.93%. It was concluded that densitometry values beyond the range established in the present study might indicate the presence of bone alteration in the tibia of broilers.
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Eqüinos da raça Quarto de Milha, 30 machos e 30 fêmeas com idade entre 42 e 48 meses, apresentando a epífise distal do rádio fechada, em plena atividade esportiva, foram analisados quanto à densidade mineral óssea (DMO) do acessório do carpo, tendo os valores expressos em milímetros de alumínio (mmAl). As radiografias da estrutura óssea, juntamente com uma escala de alumínio (penetrômetro) foram analisadas por meio de um programa computacional, especialmente desenvolvido para medida da densidade óptica em imagem radiográfica. O valor médio encontrado para as fêmeas foi de 4,49±0,69mmAl, com idade média de 43±2 meses e, para os machos, de 4,43 ± 0,81mmAl, com idade média de 45±2 meses, não havendo diferença significativa na DMO entre os sexos.
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Em 12 fêmeas e 12 machos da raça Puro Sangue Inglês com idade média de 12 meses, avaliou-se os valores normais da densidade mineral óssea do carpo acessório em milímetros de alumínio (mmAl) até o momento do fechamento completo da epífise distal do rádio, por meio do método de densitometria óptica em imagens radiográficas. A avaliação foi realizada por meio de um programa computacional (software) especialmente desenvolvido para medida de densidade óptica em filmes de raios-X, o qual contém a imagem radiográfica do osso carpo acessório, região de partes moles adjacente ao carpo acessório e os degraus de uma escala de alumínio (phatom), que permitiu a medida de densidade mineral óssea, sendo esta a média aritmética da região de interesse determinada no osso carpo acessório correspondente ao valor em milímetros da escala. Os valores da densidade mineral óssea em mmAl do acessório do carpo em função da idade não apresentaram diferenças entre os sexos (p=0,86) permitindo que uma equação de reta fosse ajustada para ambos os sexos (densidade mineral óssea (DMO) mmAl = 3.109 + 0,056 x idade em meses), na faixa etária estudada.
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Background: This study investigated the influence of the period after ovariectomy on femoral and mandibular bone mineral density (BMD) and on induced periodontal disease.Methods: One hundred and twenty-six female Holtzman rats were divided into nine groups: control, sham surgery (SHAM) with and without induction of periodontal disease for 51 and 150 days, and ovariectomy (OVX) with and without induction of periodontal disease for 51 and 150 days. Periodontal disease was induced by placing ligatures on the first lower molars during the last 30 days of each period. BMD was measured by dual-energy x-ray absorptiometry. Vertical bone loss was determined by measuring the distance from the alveolar bone crest to the cemento-enamel junction on the mesial side of the first lower molar.Results: Statistical analyses (Kruskal-Wallis test) revealed a significant difference between the OVX and SHAM groups' global and femoral proximal epiphysis BMD (P < 0.001) for 150 days and in the global evaluation for 51 days. For mandibular BMD, no difference was found between the groups of each period. Influence of the period on femoral BMD was found only for the SHAM groups, with lower BMD for the 51-day period compared to the 150-day period (P < 0.05). In the global evaluation of the mandible, a lower BMD was found after 51 days. The period was a contributing factor for the vertical bone loss, and it resulted in higher values for the 51-day period (P < 0.05).Conclusion: the period influenced the femoral BMD and the vertical bone loss in induced periodontal disease.
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Natural or synthetic materials may be used to aid tissue repair of fracture or pathologies where there has been a loss of bone mass. Polymeric materials have been widely studied, aiming at their use in orthopaedics and aesthetic plastic surgery. Polymeric biodegradable blends formed from two or more kinds of polymers could present faster degradation rate than homopolymers. The purpose of this work was to compare the biological response of two biomaterials: poly(L-lactic acid)PLLA and poly(L-lactic acid)PLLA/poly(ethylene oxide)PEO blend. Forty four-week-old rats were divided into two groups of 20 animals, of which one group received PLLA and the other PLLA/PEO implants. In each of the animals, one of the biomaterials was implanted in the proximal epiphysis of the right tibia. Each group was divided into subgroups of 5 animals, and sacrificed 2, 4, 8 and 16 weeks after surgery, respectively. Samples were then processed for analysis by light microscopy. Newly formed bone was found around both PLLA and PLLA/PEO implants. PLLA/PEO blends had a porous morphology after immersion in a buffer solution and in vivo implantation. The proportion 50/50 PLLA/PEO blend was adequate to promote this porous morphology, which resulted in gradual bone tissue growth into the implant.
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Aging is associated with decline in muscle mass and strength and reduced bone density. Age-related bone loss is a primary factor in osteoporosis and all individuals are potential candidates for osteoporosis because bone loss with aging occurs in men and women, but less studied in men. To examine the appropriateness of hindlimb elevation, by tail suspension as a model for diminished mechanical loading, and to determine the influence of age on bone responsiveness to skeletal unloading, we use dual X ray absorptiometry (DXA) and digital radiographic images to analyze the response of the femur from mature rats to biomechanical loads. Femurs from male Wistar rats (9-mo-old) were scanned using DXA and DIGORA and measures obtained in ephipyseal and diaphyseal regions of interest. The mechanical testing was divided into compression load to fracture the head and a three-point bending load to fracture the femur middiaphysis. In femoral epiphysis from hindlimb unload (HU), animals presented significant differences between mineral bone content and density assessed by DXA. Detailed regions of femoral epiphysis (head, throcanteric fossa, throcanter and metaphysis) presented significant lower values from radiographic density. Only compressive load necessary to fracture the femoral head neck was also significantly diminished in HU animals. Disuse induced, as in elderly patients, deterioration of the trabecular bone architecture with critical effect on bone fragility. Rats with 21 days of hindlimb unloading can simulate disuse, suggesting that certain sub-regions of their aging bones are more susceptible to fracture, while other, i.e. diaphyses, are not.
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Introduction: Bone strength is influenced by a number of different determinants, such as mass, size, geometry and also by the intrinsic material properties of the tissue. Aims: The structure and mechanical properties of the femur were analyzed in aged (14 mo-old) animals submitted to hindlimb unloading (HU) for 21 days. Methods: Twenty Wistar rats were randomly divided into Control and HU groups and the femur was submitted to dual X ray absorptiometry (DXA), DIGORA radiographic density, mechanical compression testing and Knoop microhardness analyse in cortical and cancellous bone. Results: Femurs from HU group presented significantly lower failure load, decreased bone mineral density (BMD)/bone mineral content (BMC) in whole bone; proximal/distal epiphysis and middiaphyseal cortical bone measured by DXA were similar in the two groups; radiographic density from areas in proximal epiphysis was significantly lower in HU group, and microhardness measured at periosteal and endosteal levels were also signifcantly diminished in HU compared with Control group. Conclusion: Disuse induced damage in the trabecular femoral bone architecture with decisive effect on the head and trochanteric fossa, which became weaker. Bone diaphyseal cortical hardness also suffered effect of unloading, probably related to osteocyte/osteoblast activity.
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It was evaluated the effect of nonphytate phosphorus (NNP) and phytase on broiler tibia. One thousand and two hundred chicks were allocated in a completely randomized design and factorial arrangement 4 x 3 (NPP x phytase levels), with four replicates. NPP levels, at each phase, were 0.45, 0.37, 0.29 and 0.21% - initial, 0.41, 0.33, 0.25 and 0.17% - growth, and 0.37, 0.29, 0.21 and 0.13% - withdrawal. Phytase levels were 0, 500 and 1000 FTU/kg of diet. There was no effect on diameter at 21 days of age. Tibia with lower weight, length and diaphysis, distal epiphysis and average densities e proximal epiphysis density resulted from NPP reduction from 0.37 to 0.29% and from 0.29 to 0.21%, respectively. Inclusion of 500 FTU/kg of phytase improved length and diaphysis density of the tibia, independent of NPP levels. Diets with NPP, at initial, growth and final phases, of 0.37, 0.33 and 0.29%, respectively, supplemented with 1000 FTU/kg of phytase, can be used with no negative effect on bone quality in broilers.
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Background: Spondyloepiphyseal dysplasia-brachydactyly and distinctive speech (SED-BDS) is a syndrome characterized by short stature, disproportionately short limbs, peculiar face, thick and abundant hair, high-pitched and coarse voice, small epiphyses, brachymetacarpalia, brachymetatarsalia and brachy-phalangia of fingers and toes, small pelvis and delayed carpal bone age, among other features. Case Report: We report a Brazilian patient with father, brother and sister presenting with the same typical features of the syndrome. Clinically, he showed disproportionately short stature, rhizo-meso-acromelic shortness of the extremities, short hands and feet, a peculiar distinctive high-pitched voice, peculiar facies, and other features already reported as characteristic of this syndrome. Radiographic fndings included shape anomalies of the vertebral bodies such as cuboid-shaped vertebral bodies, mild scoliosis, short and broad tubular bones, brachymetacarpalia, brachymetatarsalia, and brachy-dactyly, lumbar hyperlordosis, generalized osteopenia, and hypoplastic iliac wings. Conclusions: Few cases have been described, as this is a rare skeletal dysplasia. This paper describes a new familial case of SED-BDS. © The American Journal of Case Reports.
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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.