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1.
J Orthop Res ; 30(8): 1254-62, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22234948

RESUMO

The hypothalamus is of critical importance in regulating bone remodeling. This is underscored by the fact that intracerebroventricular-application of leptin in ewe leads to osteopenia. As a large animal model of osteoporosis, this approach has some limitations, such as high technical expenditure and running costs. Therefore we asked if a surgical ablation of the leptin signaling axis would have the same effects and would thereby be a more useful model. We analyzed the bone phenotype of ewe after surgical hypothalamo-pituitary disconnection (HPD + OVX) as compared to control ewe (OVX) after 3 and 12 months. Analyses included histomorphometric characterization, micro-CT and measurement of bone turnover parameters. Already 3 months after HPD we found osteopenic ewe with a significantly decreased bone formation (69%) and osteoclast activity (49%). After a period of 12 months the HPD group additionally developed an (preclinical) osteoporosis with significant reduction (33%) of femoral cortical thickness, as compared to controls (OVX). Taken together, HPD leads after 12 month to osteoporosis with a reduction in both trabecular and cortical bone caused by a low bone turnover situation, with reduced osteoblast and osteoclast activity, as compared to controls (OVX). The HPD-sheep is a suitable large animal model of osteoporosis. Furthermore our results indicate that an intact hypothalamo-pituitary axis is required for activation of bone turnover.


Assuntos
Hipotálamo/fisiologia , Osteoporose/etiologia , Hipófise/fisiologia , Animais , Remodelação Óssea/fisiologia , Modelos Animais de Doenças , Feminino , Hipotálamo/cirurgia , Osteoblastos/metabolismo , Osteoclastos/metabolismo , Osteoporose/diagnóstico por imagem , Radiografia , Carneiro Doméstico
2.
Naturwissenschaften ; 97(4): 393-402, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20182683

RESUMO

Although numerous bodies were deposited in Western European bogs in the past centuries, few were found and underwent archeological analysis. No studies comparing skeletal structure and mineralization of bog bodies from different ages have been performed to this day. Therefore, the aim of this study was to analyze and compare skeletal features and specifics of the human remains of three bog bodies from the Iron and Middle Ages found in Northern European peat bogs. Demineralization due to the acidic environment in peat bogs was comparably pronounced in all three bodies. Still, the macroscopic state of skeletal preservation was excellent. In addition to contact radiography, we used peripheral quantitative computed tomography to measure cortical bone mineral density. The conservation of skeletal three-dimensional microstructural elements was assessed by high-resolution microcomputed tomography analysis. These techniques revealed severe differences in bone mineral density and enabled us to determine handedness in all three bodies. Additionally, unique skeletal features like intravital bone lesions, immobilization osteoporosis, and Harris lines were found. A deformity of the left femoral head was observed which had the typical appearance of an advanced stage of Legg-Calve-Perthes disease. This study gives detailed insight into the skeletal microstructure and microarchitecture of 800- to 2,700-year-old bog bodies. Skeletal analysis enables us to draw conclusions not only concerning changes in the acidic environment of the bog, but also serves as a diagnostic tool to unravel life circumstances and diseases suffered by humans in the Iron and Middle Ages.


Assuntos
Densidade Óssea , Solo , Osso e Ossos/anatomia & histologia , Feminino , Lateralidade Funcional , Alemanha , História Antiga , História Medieval , Humanos , Osteoporose/diagnóstico , Esqueleto , Tomografia Computadorizada por Raios X , Áreas Alagadas
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