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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

CD166 modulates disease progression and osteolytic disease in multiple myeloma

Xu, Linlin 16 March 2016 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Multiple myeloma (MM) is an incurable malignancy characterized by the proliferation of neoplastic plasma cells in the bone marrow (BM) and by multiple osteolytic lesions throughout the skeleton. We previously reported that CD166 is a functional molecule on normal hematopoietic stem cells (HSC) that plays a critical role in HSC homing and engraftment, suggesting that CD166 is involved in HSC trafficking and lodgment. CD166, a member of the immunoglobulin superfamily capable of mediating homophilic interactions, has been shown to enhance metastasis and invasion in several tumors. However, whether CD166 is involved in MM and plays a role in MM progression has not been addressed. We demonstrated that a fraction of all human MM cell lines tested and MM patients’ BM CD138+ cells express CD166. Additionally, CD166+ cells preferentially home to the BM of NSG mice. Knocking-down (KD) CD166 expression on MM cells with shRNA reduced their homing to the BM. Furthermore, in a long-term xenograft model, NSG mice inoculated with CD166KD cells showed delayed disease progression and prolonged survival compared to mice receiving mock transduced cells. To examine the potential role of CD166 in osteolytic lesions, we first used a novel Ex Vivo Organ Culture Assay (EVOCA) which creates an in vitro 3D system for the interaction of MM cells with the bone microenvironment. EVOCA data from MM cells lines as well as from primary MM patients’ CD138+ BM cells demonstrated that bone osteolytic resorption was significantly reduced when CD166 was absent on MM cells or calvarial cells. We then confirmed our ex vivo findings with intra-tibial inoculation of MM cells in vivo. Mice inoculated with CD166KD cells had significantly less osteolytic lesions. Further analysis demonstrated that CD166 expression on MM cells alters bone remodeling by inhibiting RUNX2 gene expression in osteoblast precursors and increasing RANKL to OPG ratio in osteoclast precursors. We also identified that CD166 is indispensable for osteoclastogenesis via the activation of TRAF6-dependent signaling pathways. These results suggest that CD166 directs MM cell homing to the BM and promotes MM disease progression and osteolytic disease. CD166 may serve as a therapeutic target in the treatment of MM.
22

Effet de l’absence du CFTR sur la réponse à l’hormone parathyroïdienne (PTH) de cellules stromales mésenchymateuses osseuses et d’ostéoblastes murins

Djite, ElHadji Mouhamadou Sakhir 07 1900 (has links)
La maladie osseuse liée à la fibrose kystique (MOLFK) est une comorbidité qui se caractérise par une faible densité osseuse découlant d’une diminution de la formation osseuse et d’une augmentation de la résorption osseuse. Les ostéoblastes (Ob), les cellules responsables de la formation osseuse, sont principalement affectées par la MOLFK. Le Cystic fibrosis transmembrane conductance regulator (CFTR), dont le gène est muté chez les patients FK, est exprimé par les Ob. Des études réalisées sur des modèles murins FK ont démontré que l’expression du gène Cftr est importante pour la différenciation des cellules souches mésenchymateuses (CSM) en Ob matures et pour la fonction des Ob. Nous avons également montré que l’absence du CFTR affecte les cellules mâles et femelles de façon distincte. Or, les mécanismes par lesquels l’absence du CFTR entraine ces perturbations restent méconnus. Afin d’expliquer ces perturbations, nous avons ciblé l’hormone parathyroïdienne (PTH) dont la liaison à son récepteur PTHR1 active des voies de signalisation impliquées dans la régulation de la différenciation des Ob. Nous proposons que l'absence du CFTR mènera à une altération sexe spécifique de la réponse à la PTH des CSM et des Ob. En utilisant des cellules issues de souris mâles et femelles Cftr+/+ et Cftr-/- traitées ou non à la PTH, nous avons investigué: 1) les niveaux d’expression génique et protéique de PTHR1; 2) l’activation de l’une des voies de signalisation PTH/PTHR1 (ERK1/2); 3) les niveaux d’expression des gènes cibles ostéoblastiques (receptor activator of nuclear factor-κB ligand (RANKL), ostéoprotégérine (OPG), Runx2, phosphatase alcaline (ALP), ostéocalcine) et ostéocytaires (Matrix Extracellular Phosphoglycoprotein (MEPE) et sclérostine) et; 4) la fonction ostéoblastique (activité de l’ALP). Nos résultats montrent que les niveaux d’expression génique de PTHR1 sont similaires entre les cellules Cftr+/+ et Cftr-/- traitées ou non à la PTH mais que l’expression protéique basale de PTHR1 est abaissée chez les cellules Cftr-/- femelles. La PTH induit la phosphorylation de ERK1/2 dans les cellules Cftr+/+ (mâles et femelles) et Cftr-/- mâles alors que cet effet est absent chez les cellules Cftr-/- femelles. La PTH augmente le ratio RANKL/OPG et diminue l’expression des gènes ostéoblastiques et ostéocytaires des cellules Cftr+/+ alors que les cellules Cftr-/- femelles démontrent une absence complète de réponse à la PTH. L’activité de l’ALP ne diffère pas entre les cellules Cftr+/+ et Cftr-/- traitées ou non à la PTH. Ces résultats suggèrent que l’absence du CFTR est associée à des altérations de la réponse à la PTH des CSM et Ob murins plus marquées chez les femelles. Une meilleure compréhension de la physiopathologie de la MOLFK et de l’influence du sexe biologique, pourrait mener à une personnalisation des thérapies de la MOLFK. / Cystic fibrosis bone-related disease (CFBD) is a comorbidity characterized by the presence of low bone mass resulting from a decrease in bone formation and an increase in bone resorption. Osteoblasts (Ob), the cells responsible for bone formation, are primarily affected by CFBD. The Cystic fibrosis transmembrane conductance regulator (CFTR), the mutated gene in cystic fibrosis (CF), is expressed by Ob. Using CF mouse models, we and other have shown that the presence of Cftr is important for the differentiation of murine mesenchymal stem cells (MSCs) into mature Ob and for Ob function. Interestingly, we found that the loss of CFTR affected cells coming from males and females differently. However, the mechanisms by which the CFTR causes these alterations are poorly understood. In order to explain these alterations, we focused on the parathyroid hormone (PTH)-PTHR1 signaling pathways, which are involved in the regulation of Ob differentiation. We propose that the absence of CFTR leads to gender-specific alterations in the response of MSCs and Ob to PTH. Using cells isolated from Cftr+/+ and Cftr-/- males and females and treated or not with PTH, we investigated the : 1) gene and protein expression levels of PTHR1; 2) activation of one of the PTH-PTHR1 signaling pathways (ERK1/2); 3) expression levels of Ob (receptor activator of nuclear factor-κB ligand (RANKL), osteoprotegerin (OPG), Runx2, alkaline phosphatase (ALP), osteocalcin) and osteocyte target genes (Matrix Extracellular Phosphoglycoprotein (MEPE) and sclerostin) and; 4) osteoblast function (ALP activity). Our data show that gene expression levels of PTHR1 are similar between Cftr+/+ and Cftr-/- treated or not with PTH; however basal protein expression of PTHR1 is decreased in Cftr-/- female cells. PTH induces ERK1/2 phosphorylation in Cftr+/+ (males and females) and Cftr-/- (males), but this effect is absent in cells coming from Cftr-/- females. PTH increases the RANKL/OPG ratio and decreases the expression of Ob and osteocyte genes in Cftr+/+ cells. PTH fails to modulate the expression of these genes in Cftr-/- female cells. ALP activity is similar between Cftr+/+ and Cftr-/- cells treated or not with PTH. These results suggest that the absence of CFTR is associated with alterations in the response to PTH of murine MSCs and Ob that are more pronounced in cells coming from females. A better understanding of the pathophysiology of CFBD, and the influence of biological sex, may lead to better tailored therapies for CFBD.
23

Understanding the occupational adaptation process of individuals with osteogenesis imperfecta and their families to promote participation and occupational engagement : A scoping review

Männi, Kadi January 2023 (has links)
Introduction: Osteogenesis imperfecta (OI) is a condition that affects the whole family on many levels and is important to consider the management of the disease and its impact on occupational participation and engagement in daily activities. Aim: To explore the natural occupational adaptation process (OAP) and its impact on daily activities among individuals and families with OI. Method: Using Arksey and O’Malley’s five-step Scoping Study Framework (2005), a scoping review of 24 articles from seven online databases and literature hand-searching was conducted. Data extraction was performed for all studies that met the eligibility and quality criteria. Five main themes containing several subthemes were emerged in qualitative inductive thematic analysis. Findings: Findings from 24 reports highlight the social and emotional impact along with the physical challenges of living with OI that direct into adaptation process. Different occupational adaptation strategies that emerged in the data help overcome physical deficits and psychosocial implications and facilitate occupational participation and engagement in meaningful activities. Conclusions: The study confirmed these individuals’ and families’ high coping skills, despite experiencing many obstacles in their daily life. Significance: To better understand the adaptation process in OI population and give practical implications for occupational therapists to offer a better support these families need.
24

Vers une meilleure compréhension de la pathogenèse de la maladie osseuse reliée à la fibrose kystique

Orlando, Valérie 08 1900 (has links)
Les patients atteints de la fibrose kystique (FK) ont désormais un âge médian de survie dépassant la cinquantaine. Par contre, avec ce vieillissement surviennent de nouvelles complications dont l'une des plus prévalente est la maladie osseuse associée à la FK. Les souris dont le Cftr est invalidé génétiquement présentent une densité osseuse amoindrie qui découle d’un débalancement du remodelage osseux caractérisé par une diminution de la formation et une augmentation de la résorption osseuse. L'observation que plusieurs modèles murins FK ont un phénotype ostéopénique et ce, même en absence de certains facteurs étiologiques (inflammation chronique, prise de glucocorticoïdes, insuffisance pancréatique etc.) laisse croire que le Cftr, le gène muté dans la FK, joue un rôle non-négligeable dans le métabolisme osseux. Le présent projet étudiera l’impact de l’absence du CFTR, sur les ostéoblastes (Ob) et ostéoclastes (Oc) dans un modèle murin de FK, soit les souris Cftr-/- de souche BALB/c. De plus, les Ob, sont reconnus comme ayant un effet modulateur sur le microenvironnement leucocytaire de la moelle osseuse (MO). Ce projet visera également à investiguer l’impact de l’absence du CFTR sur la niche leucocytaire de la MO. Nos résultats de densitométrie osseuse et de microtomographie à rayons X ont confirmé que les souris Cftr -/- ont une densité osseuse et un contenu minéral osseux abaissé, une diminution du volume osseux trabéculaire, un nombre amoindri de travées osseuses et une plus grande séparation entre les travées comparé aux souris Cftr+/+. Afin de mieux comprendre ce phénotype osseux, nous avons vérifié et confirmé que l’expression génique et protéique du CFTR est présente chez des Ob dérivés de la MO, mais est absent au niveau des Oc dérivés de la MO. Ces observations corroborent nos résultats portant sur la différenciation des cellules osseuses où nous avons démontré que seule la différenciation et fonction ostéoblastique sont affectées par l'absence du CFTR. Ce défaut ostéoblastique semble influencer négativement la leucopoïèse puisque nous observons une quantité moindre de cellules T, de macrophages et de cellules dendritiques chez les souris Cftr -/- vs. Cftr +/+. À la lumière de ces résultats, l'absence du CFTR semble avoir un impact important sur les ostéoblastes et la moelle osseuse. / With cystic fibrosis (CF) patients now being able to live past fifty years of age come a multitude of secondary complications; one of the most important being cystic fibrosis-related bone disease (CFBD). In Cftr-null mice, this disease is caracterized by a low bone mineral density caused by an uncoupled bone remodeling. However, the observation that various models of CF mice display a bone phenotype despite the absence of the usual human confounders (i.e. inflammation, steroid hormone use, pancreatic insufficiency, etc.) led us to propose that CFTR, itself, plays a non-negligible role in the regulation of bone metabolism. This project will study the impact of the absence of CFTR on the osteoblasts (Ob) and osteoclasts (Oc) in a CF mouse model, namely the BALB/c Cftr-/- mice. In addition, Ob are recognized as having a modulating effect on the leukocyte microenvironment of the bone marrow (BM). This project will also investigate the impact of the absence of CFTR on the leukocyte niche in the BM. Our bone densitometry and X-ray microtomography results showed that Cftr -/- mice have lower bone density and bone mineral content vs. Cftr +/+ mice as well as a decrease in trabecular bone volume and trabecular number, and a greater trabecular separation. To further understand this bone phenotype, we confirmed that BM- derived Ob expressed CFTR at the gene and protein level, but not BM-derived osteoclasts. Such observations support our findings showing that only Ob differenciation and function were affected by the absence of CFTR. The osteoblastic defect appears to adversely affect the BM leukopoiesis as decreased numbers of T cells, macrophages and dendritic cells were observed in Cftr -/- mice vs. Cftr +/+. In light of these findings, we believe that the absence of CFTR has an important impact on the Ob and the bone marrow.
25

Determinação dos níveis séricos de vitamina D em uma amostra de indivíduos saudáveis da população brasileira / Determination of the vitamin D levels in healthful individuals of the Brazilian population

Unger, Marianna Durante 01 April 2010 (has links)
A insuficiência de vitamina D (25(OH)D < 30 ng/ml) é frequentemente subdiagnosticada, especialmente em paises onde a radiação solar é considerada suficiente. A diminuição desse hormônio está relacionada ao desenvolvimento de alterações ósteo-metabólicas, hiperparatireoidismo secundário (HPTS) e maior risco de doenças crônicas. OBJETIVO: Determinar os níveis de 25(OH)D e sua relação com o metabolismo mineral em uma amostra de voluntários clinicamente estáveis imediatamente após o inverno e verão. MÉTODO: Corte transversal em São Paulo, 603 voluntários (118M e 485F) entre 18-90 anos (47,8 + 13,4) selecionados no Hospital Universitário- USP em setembro e outubro de 2006. Posteriormente, no período de março e abril de 2007, foram reconvocados para coleta de sangue 209 voluntários (31M e 178F) entre 18-81 anos (47,4 + 11,5). Hipovitaminose D foi considerada quando <30 ng/ml e HPTS quando <87 pg/ml. RESULTADOS: Após o inverno o valor médio de 25(OH)D foi de 21,4 (16,2 - 28,7) ng/ml e 77,4% dos indivíduos apresentaram hipovitaminose D. Os negros apresentaram níveis de 25(OH)D reduzidos quando comparados aos brancos (p = 0.019). A vitamina D se associou a idade (b = -0,07, p = 0,03) e a cor da pele (b = 2,16, p = 0,02). A insuficiência de vitamina D foi associada ao paratormônio (b = 0,014, p = 0,011). Foi verificado aumento significativo nos níveis de 25(OH)D após o verão [22,0 (16,6 28,8) vs. 34,0 (26,1 43,5), p < 0.001], com conseqüente redução no PTH. As prevalências de hipovitaminose D e HPTS foram menores após o verão. A normalização dos níveis séricos de vitamina D na segunda análise foi dependente da idade (b = -0,049, p = 0,03). O HPTS foi associado ao clearance de creatinina (b = 0,20, p < 0,001). Uma menor prevalência da HPTS foi demonstrada quando 25(OH)D > 40 ng/mL (p = 0,027). CONCLUSÃO: Foi verificada maior prevalência de hipovitaminose D e HPTS após o inverno. Esta prevalência foi reduzida, mas não sanada após o verão. Níveis > 40 ng/mL estão associados à menor prevalência de HPTS. Nossos dados sugerem a necessidade de implantação de políticas públicas de monitorização da deficiência da vitamina D nas populações sob maior risco e suplementação nos casos em que isto seja necessário / Vitamin D insufficiency (25(OH)D <30 ng/mL) is frequently under-diagnosed, mainly in countries where solar radiation is abundant. The reduction of this hormone is related to the development of bone metabolic alterations, secondary hyperparathyroidism (SHPT) and greater risk of chronic illnesses. OBJECTIVE: To evaluate the status of vitamin D and the relationship of circulating 25(OH)D with serum parameters of mineral metabolism in the cohort of healthy volunteers after the winter and summer. METHODS: Cohort study in São Paulo (SP), 603 volunteers (118M and 485W), between 18-90 years (47.8 + 13.4) selected in the University Hospital in September and October of 2006. Later, in the period of March and April of 2007, they had been contacted for new blood collection, 209 volunteers (31M and 178F) between 18-81 years (47.4 + 11.5). Hypovitaminosis D was when 25(OH)D < 30ng/mL and SHPT was considered when PTH > 87pg/mL. RESULTS: After the winter, the average value of 25(OH)D was 21.4 ng/mL (16.2 28.7) and 77.4% of the individuals had presented vitamin D deficiency. The afro-Americans presented levels of 25(OH)D reduced when compared with the Caucasians (p = 0.019). Vitamin D was dependent on age (b = -0.07, p = 0.03) and the color of the skin (b = 2.16, p = 0.02). Vitamin deficiency D was associated with PTH (b = 0.014, p = 0.011). Significant increase in the levels of 25(OH)D was observed after summer [22.0 (16.6 28.8) vs. 34.0 (26.1 43.5), p<0.001] with consequent reduction in the PTH. The prevalence of hypovitaminosis D and SHPT decreased after summer. The normalization of the vitamin D levels in the second analysis was dependent on age (b = -0.049, p = 0.03). The SHPT was associated to creatinine clearance (b = 0.20, p < 0.001). Lower prevalence of the SHPT was demonstrated when 25(OH)D > 40ng/mL (p = 0.027). CONCLUSION: In SP, after winter, a significant prevalence of hypovitaminosis D and SHPT was observed. This prevalence was reduced, but not solved after summer. Levels > 40 ng/mL were associated with a lower prevalence of HPTS. Our data suggest that our country needs to establish a permanent monitoring of serum vitamin D in selected populations and treat those who are at a higher risk of hypovitaminosis D
26

Avaliação do efeito do hormônio tireoideano na estrutura e fisiologia óssea de camundongos com inativação do Gene do adrenoceptor <font face=\"Symbol\">a2A. / Evaluation of the effect of thyroid hormone on bone structure and physiology of mice with inactivation of Gene <font face=\"Symbol\">a2A-adrenoceptor.

Martins, Gisele Miyamura 05 February 2013 (has links)
Um dos mais importantes achados dos últimos anos foi o de que o remodelamento ósseo está sujeito ao controle do SNC, com o SNS agindo como efetor periférico. Um estudo do nosso grupo demonstrou que camundongos <font face=\"Symbol\">a2A/<font face=\"Symbol\">a2C-AR-/- apresentam um fenótipo de alta massa óssea, como também são resistentes à osteopenia induzida pelo excesso de hormônio HT. Com o intuito de verificar a participação do <font face=\"Symbol\">a2A-AR-/- nestes processos, tivemos como objetivos: caracterizar o fenótipo ósseo de camundongos <font face=\"Symbol\">a2A-AR-/- e avaliar o efeito do HT na estrutura óssea desses camundongos tratados. Pudemos observar que o comprimento longitudinal dos ossos dos animais <font face=\"Symbol\">a2A-AR-/- são menores do que dos animais selvagens e a análise por <font face=\"Symbol\">mCT do fêmur mostrou uma diminuição da porosidade da cortical. Com relação ao tratamento com hormônio tireoideano, os animais <font face=\"Symbol\">a2A-AR-/- tratados com T3 foram resistentes à diminuição do comprimento dos ossos causado pelo excesso de HT e vimos, ainda, que o osso trabecular dos animais <font face=\"Symbol\">a2A-AR-/- foi mais sensível aos efeitos deletérios da tirotoxicose, entretanto o osso cortical e parâmetros biomecânicos ósseos dos animais KOs foram menos sensíveis. Em conclusão, o presente estudo sugere que o <font face=\"Symbol\">a2A-AR está envolvido no processo de crescimento ósseo e que esse receptor possa mediar, pelo menos parcialmente, ações negativas do T3 nesse processo como também do HT no osso cortical. / One of the most important finds of the recent years is that bone remodeling is subject to the control of the CNS, with SNS acting as the peripheral effector. However, a recent study of our group showed that mice <font face=\"Symbol\">a2A/<font face=\"Symbol\">a2C-AR-/- have a high bone mass phenotype, even though are resistant to the thyroid hormone-induced osteopenia. In order to verify the role of <font face=\"Symbol\">a2A-AR-/- in these cases, we had as objectives to evaluate whether the isolated inactivation of <font face=\"Symbol\">a2A-AR interferes with the bone structure, and to evaluate the action of HT on these animals. We have observed that the longitudinal length of the bones of <font face=\"Symbol\">a2A-AR-/- animals are lower than those of wild type animals and the analysis of the femur by <font face=\"Symbol\">mCT showed a lower cortical porosity. With regard to treatment with thyroid hormone, we observed that <font face=\"Symbol\">a2A-AR-/- animals were resistant to the bone length decrease caused by thyroid hormone excess. We also noticed that the trabecular bone of <font face=\"Symbol\">a2A-AR-/- animals was more sensitive to the deleterious effects of thyrotoxicosis. Moreover, the cortical bone and bone biomechanical parameters KO animals were less sensitive. In conclusion, the findings of this study suggest that <font face=\"Symbol\">a2A-AR is involved in the process of bone growth and that this receptor may mediate at least partly, negative actions of T3 in this process as well as the HT in the cortical bone.
27

Avaliação do efeito do hormônio tireoideano na estrutura e fisiologia óssea de camundongos com inativação do Gene do adrenoceptor <font face=\"Symbol\">a2A. / Evaluation of the effect of thyroid hormone on bone structure and physiology of mice with inactivation of Gene <font face=\"Symbol\">a2A-adrenoceptor.

Gisele Miyamura Martins 05 February 2013 (has links)
Um dos mais importantes achados dos últimos anos foi o de que o remodelamento ósseo está sujeito ao controle do SNC, com o SNS agindo como efetor periférico. Um estudo do nosso grupo demonstrou que camundongos <font face=\"Symbol\">a2A/<font face=\"Symbol\">a2C-AR-/- apresentam um fenótipo de alta massa óssea, como também são resistentes à osteopenia induzida pelo excesso de hormônio HT. Com o intuito de verificar a participação do <font face=\"Symbol\">a2A-AR-/- nestes processos, tivemos como objetivos: caracterizar o fenótipo ósseo de camundongos <font face=\"Symbol\">a2A-AR-/- e avaliar o efeito do HT na estrutura óssea desses camundongos tratados. Pudemos observar que o comprimento longitudinal dos ossos dos animais <font face=\"Symbol\">a2A-AR-/- são menores do que dos animais selvagens e a análise por <font face=\"Symbol\">mCT do fêmur mostrou uma diminuição da porosidade da cortical. Com relação ao tratamento com hormônio tireoideano, os animais <font face=\"Symbol\">a2A-AR-/- tratados com T3 foram resistentes à diminuição do comprimento dos ossos causado pelo excesso de HT e vimos, ainda, que o osso trabecular dos animais <font face=\"Symbol\">a2A-AR-/- foi mais sensível aos efeitos deletérios da tirotoxicose, entretanto o osso cortical e parâmetros biomecânicos ósseos dos animais KOs foram menos sensíveis. Em conclusão, o presente estudo sugere que o <font face=\"Symbol\">a2A-AR está envolvido no processo de crescimento ósseo e que esse receptor possa mediar, pelo menos parcialmente, ações negativas do T3 nesse processo como também do HT no osso cortical. / One of the most important finds of the recent years is that bone remodeling is subject to the control of the CNS, with SNS acting as the peripheral effector. However, a recent study of our group showed that mice <font face=\"Symbol\">a2A/<font face=\"Symbol\">a2C-AR-/- have a high bone mass phenotype, even though are resistant to the thyroid hormone-induced osteopenia. In order to verify the role of <font face=\"Symbol\">a2A-AR-/- in these cases, we had as objectives to evaluate whether the isolated inactivation of <font face=\"Symbol\">a2A-AR interferes with the bone structure, and to evaluate the action of HT on these animals. We have observed that the longitudinal length of the bones of <font face=\"Symbol\">a2A-AR-/- animals are lower than those of wild type animals and the analysis of the femur by <font face=\"Symbol\">mCT showed a lower cortical porosity. With regard to treatment with thyroid hormone, we observed that <font face=\"Symbol\">a2A-AR-/- animals were resistant to the bone length decrease caused by thyroid hormone excess. We also noticed that the trabecular bone of <font face=\"Symbol\">a2A-AR-/- animals was more sensitive to the deleterious effects of thyrotoxicosis. Moreover, the cortical bone and bone biomechanical parameters KO animals were less sensitive. In conclusion, the findings of this study suggest that <font face=\"Symbol\">a2A-AR is involved in the process of bone growth and that this receptor may mediate at least partly, negative actions of T3 in this process as well as the HT in the cortical bone.
28

Determinação dos níveis séricos de vitamina D em uma amostra de indivíduos saudáveis da população brasileira / Determination of the vitamin D levels in healthful individuals of the Brazilian population

Marianna Durante Unger 01 April 2010 (has links)
A insuficiência de vitamina D (25(OH)D < 30 ng/ml) é frequentemente subdiagnosticada, especialmente em paises onde a radiação solar é considerada suficiente. A diminuição desse hormônio está relacionada ao desenvolvimento de alterações ósteo-metabólicas, hiperparatireoidismo secundário (HPTS) e maior risco de doenças crônicas. OBJETIVO: Determinar os níveis de 25(OH)D e sua relação com o metabolismo mineral em uma amostra de voluntários clinicamente estáveis imediatamente após o inverno e verão. MÉTODO: Corte transversal em São Paulo, 603 voluntários (118M e 485F) entre 18-90 anos (47,8 + 13,4) selecionados no Hospital Universitário- USP em setembro e outubro de 2006. Posteriormente, no período de março e abril de 2007, foram reconvocados para coleta de sangue 209 voluntários (31M e 178F) entre 18-81 anos (47,4 + 11,5). Hipovitaminose D foi considerada quando <30 ng/ml e HPTS quando <87 pg/ml. RESULTADOS: Após o inverno o valor médio de 25(OH)D foi de 21,4 (16,2 - 28,7) ng/ml e 77,4% dos indivíduos apresentaram hipovitaminose D. Os negros apresentaram níveis de 25(OH)D reduzidos quando comparados aos brancos (p = 0.019). A vitamina D se associou a idade (b = -0,07, p = 0,03) e a cor da pele (b = 2,16, p = 0,02). A insuficiência de vitamina D foi associada ao paratormônio (b = 0,014, p = 0,011). Foi verificado aumento significativo nos níveis de 25(OH)D após o verão [22,0 (16,6 28,8) vs. 34,0 (26,1 43,5), p < 0.001], com conseqüente redução no PTH. As prevalências de hipovitaminose D e HPTS foram menores após o verão. A normalização dos níveis séricos de vitamina D na segunda análise foi dependente da idade (b = -0,049, p = 0,03). O HPTS foi associado ao clearance de creatinina (b = 0,20, p < 0,001). Uma menor prevalência da HPTS foi demonstrada quando 25(OH)D > 40 ng/mL (p = 0,027). CONCLUSÃO: Foi verificada maior prevalência de hipovitaminose D e HPTS após o inverno. Esta prevalência foi reduzida, mas não sanada após o verão. Níveis > 40 ng/mL estão associados à menor prevalência de HPTS. Nossos dados sugerem a necessidade de implantação de políticas públicas de monitorização da deficiência da vitamina D nas populações sob maior risco e suplementação nos casos em que isto seja necessário / Vitamin D insufficiency (25(OH)D <30 ng/mL) is frequently under-diagnosed, mainly in countries where solar radiation is abundant. The reduction of this hormone is related to the development of bone metabolic alterations, secondary hyperparathyroidism (SHPT) and greater risk of chronic illnesses. OBJECTIVE: To evaluate the status of vitamin D and the relationship of circulating 25(OH)D with serum parameters of mineral metabolism in the cohort of healthy volunteers after the winter and summer. METHODS: Cohort study in São Paulo (SP), 603 volunteers (118M and 485W), between 18-90 years (47.8 + 13.4) selected in the University Hospital in September and October of 2006. Later, in the period of March and April of 2007, they had been contacted for new blood collection, 209 volunteers (31M and 178F) between 18-81 years (47.4 + 11.5). Hypovitaminosis D was when 25(OH)D < 30ng/mL and SHPT was considered when PTH > 87pg/mL. RESULTS: After the winter, the average value of 25(OH)D was 21.4 ng/mL (16.2 28.7) and 77.4% of the individuals had presented vitamin D deficiency. The afro-Americans presented levels of 25(OH)D reduced when compared with the Caucasians (p = 0.019). Vitamin D was dependent on age (b = -0.07, p = 0.03) and the color of the skin (b = 2.16, p = 0.02). Vitamin deficiency D was associated with PTH (b = 0.014, p = 0.011). Significant increase in the levels of 25(OH)D was observed after summer [22.0 (16.6 28.8) vs. 34.0 (26.1 43.5), p<0.001] with consequent reduction in the PTH. The prevalence of hypovitaminosis D and SHPT decreased after summer. The normalization of the vitamin D levels in the second analysis was dependent on age (b = -0.049, p = 0.03). The SHPT was associated to creatinine clearance (b = 0.20, p < 0.001). Lower prevalence of the SHPT was demonstrated when 25(OH)D > 40ng/mL (p = 0.027). CONCLUSION: In SP, after winter, a significant prevalence of hypovitaminosis D and SHPT was observed. This prevalence was reduced, but not solved after summer. Levels > 40 ng/mL were associated with a lower prevalence of HPTS. Our data suggest that our country needs to establish a permanent monitoring of serum vitamin D in selected populations and treat those who are at a higher risk of hypovitaminosis D
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An assessment of metabolic bone disease in the skeletal remains of Chinese indentured mine labourers from the Witwatersrand

Meyer, Anja January 2014 (has links)
An essential part of bioarchaeology is the study of diet and nutrition and its effects on the general health of a person. Interpretation of nutritional and metabolic disease related pathologies often provide additional insight into the daily social and cultural practices of people. It is therefore also an essential part of understanding differences amongst past populations from archaeological contexts and provides an alternative means for cross referencing historical accounts. In this study the skeletal remains of 36 Chinese indentured mine labourers, who worked and died on the Witwatersrand mines during the period AD 1904-1910, were assessed for any signs of metabolic or nutritionally related signs of disease. Historical information suggests that these indentured Chinese labourers came from poverty stricken communities in China where disease and malnutrition were often encountered. Once in South Africa they were again subjected to the harsh living and working conditions associated with mining. Analyses suggest that all 36 individuals were males between the ages of 16 and 45 years, with the majority being of young adult age (20-34 years). Pathology that could be observed included a high prevalence of nutrition-related changes and linear enamel hypoplasia which suggests that the Chinese miners had been subjected to long periods of malnutrition and illness throughout childhood continuing into adulthood. Nevertheless, a large proportion of lesions associated with malnutrition showed some degree of healing. A high frequency of traumatic lesions, specifically peri-mortem fractures, was observed and may have contributed to the death of many of the Chinese miners. It therefore seems that even though the healing of pathological lesions associated with malnutrition indicated a period of improved nutritional intake, possibly during their time on the Witwatersrand mines, the high prevalence of peri-mortem fractures attests to the hazardous working conditions associated with deep-level mining. In order to aid in the interpretation of skeletal pathology associated with metabolic and nutritional diseases non-specific signs of disease observed in a cadaver skeletal sample with known causes of death (related to specific metabolic or nutritional diseases) were compared to pathology observed in the Chinese miners. This provided pathological patterns which enabled a better interpretation of the pathology observed in the Chinese skeletal remains. / Dissertation (MSc)--University of Pretoria, 2014. / am2014 / Anatomy / unrestricted
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MicroRNA and Diabetic Bone Disease

Daamouch, Souad, Emini, Lejla, Rauner, Martina, Hofbauer, Lorenz C. 20 March 2024 (has links)
Purpose of Review: The incidence of diabetes is increasing worldwide. Diabetes mellitus is characterized by hyperglycemia, which in the long-term damages the function of many organs including the eyes, the vasculature, the nervous system, and the kidneys, thereby imposing an important cause of morbidity for affected individuals. More recently, increased bone fragility was also noted in patients with diabetes. While patients with type 1 diabetes mellitus (T1DM) have low bone mass and a 6-fold risk for hip fractures, patients with type 2 diabetes mellitus (T2DM) have an increased bone mass, yet still display a 2-fold elevated risk for hip fractures. Although the underlying mechanisms are just beginning to be unraveled, it is clear that diagnostic tools are lacking to identify patients at risk for fracture, especially in the case of T2DM, in which classical tools to diagnose osteoporosis such as dual X-ray absorptiometry have limitations. Thus, new biomarkers are urgently needed to help identify patients with diabetes who are at risk to fracture. - Recent Findings: Previously, microRNAs have received great attention not only for being involved in the pathogenesis of various chronic diseases, including osteoporosis, but also for their value as biomarkers. - Summary: Here, we summarize the current knowledge on microRNAs and their role in diabetic bone disease and highlight recent studies on miRNAs as biomarkers to predict bone fragility in T1DM and T2DM. Finally, we discuss future directions and challenges for their use as prognostic markers.

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