Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.

In vertebrates, PTH receptor 1 (PTH1R) plays a pivotal role in control of bone development and homeostasis; however, how it is regulated is poorly defined. Here we report that Kindlin-2 binds to and modulates PTH1R to regulate bone mass and PTH actions. Deleting Kindlin-2 expression using the 10-kb mouse Dmp1-Cre severely impairs the anabolic effects of intermittent PTH on bone in adult mice with or without ovariectomy. Of particular interest, Kindlin-2 and Pth1r double heterozygous mice (Dmp1- Cre; Kindlin-2 f/+ ; Pth1r f/+ ), but not either singly heterozygous mice (Dmp1- Cre; Kindlin-2 f/+ or Dmp1-Cre; Pth1r f/+ ), display severe osteopenia and fail to increase bone mass in response to administration of intermittent PTH. Mechanistically, Kindlin-2 interacts with the C-terminal cytoplasmic region of PTH1R. When overexpressed, this region efficiently inhibits the endogenous PTH/PTH1R signaling in osteoblasts, which is reversed by introduction of a point mutation that abolishes the Kindlin-2 interaction. Furthermore, Kindlin-2 loss inhibits PTH-induced CREB phosphorylation and cAMP production in vitro and in bone. PTH upregulates, while estrogen deficiency downregulates, expression of Kindlin-2 in vitro and in bone. Collectively, we demonstrate that interplay between Kindlin-2 and PTH1R regulates bone mass by modulating PTH1R and provide a potential therapeutic target for metabolic bone diseases

Este estudo investigou o efeito da Roziglitazona (RTZ) sobre a perda óssea alveolar induzida pela periodontite (POAIP). Durante 3 semanas, ratos receberam sal puro de RTZ (i.p.) ou a formulaço comercial Avandia<font face=\"Symbol\">&#210; (v.o.); os grupos controles receberam os repectiovos veículos (DMSO ou CMC). Duas semanas após o inicio do tratamento, a periodontite (P) foi induzida. Após 7 dias da indução da P, as mandíbulas foram removidas para mediço da perda óssea alveolar. Amostras de osso alveolar foram analisadas por qPCR para RUNX2, Osterix, TRAF6, TRAF2, RANKL, óxido nítrico sintases (e, n e iNOS) e PPARs (<font face=\"Symbol\">a, <font face=\"Symbol\">b e <font face=\"Symbol\">g). A farmacocinética da RTZ para cada formulaço foi estudada por HPLC-MS/MS. Tanto o sal puro como a formulaço comercial de RTZ resultou no agravamento da POAIP. Apesar dos resultados similares nas concentrações plasmáticas de RTZ os mecanismos de sinalizaço parecem depender da formulaço administrada a qual pode ser devido a interferência do veículo. / This study investigate the effects of rosiglitazone (RTZ) on periodontitis-induced alveolar bone loss (PIABL). Rats received RTZ during 3 weeks, either as the pure maleate salt (i.p.) or the commercial formulation Avandia<font face=\"Symbol\">&#226; (p.o.); control animals received the respective vehicles (DMSO or CMC). Two weeks after the treatments begins, periodontitis (P) were induced. After 7 days after P induction, jaws were removed for ABL measurement. Alveolar bone samples were analyzed by qPCR for RUNX2, Osterix, TRAF6, TRAF2, RANKL, nitric oxide sintase (e, n and iNOS) and PPARs (<font face=\"Symbol\">a, <font face=\"Symbol\">b e <font face=\"Symbol\">g). RTZ pharmacokinetics from each formulation was also studied (HPLC-MS/MS). RTZ, either from the pure maleate salt or the commercial Avandia, resulted in aggravated PIABL. Despite resulting in similar plasma RTZ concentrations, signaling mechanisms seem to depend on the administered formulation which could be due to vehicle related effects interfence.

Chi Keung Cheung. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 219-251). / Chapter CHAPTER I --- LITERATURE REVIEW / Chapter 1 --- The structure of bone --- p.2 / Chapter 1.1. --- The cortical bone --- p.3 / Chapter 1.2. --- The cancellous bone --- p.3 / Chapter 2 --- The composition of bone --- p.3 / Chapter 2.1. --- Bone minerals --- p.4 / Chapter 2.2. --- The organic matrix --- p.4 / Chapter 2.3. --- The bone cells --- p.9 / Chapter 2.3.1. --- The osteoblast and the osteocyte --- p.9 / Chapter 2.3.2. --- The osteoclast --- p.11 / Chapter 3 --- Bone turnover - modelling and remodelling of bone --- p.13 / Chapter 3.1. --- Postulated sequence of bone remodelling --- p.14 / Chapter 4 --- Regulation of bone resorption --- p.16 / Chapter 4.1. --- Role of osteoblast and the lining cell on bone resorption --- p.17 / Chapter 5 --- Regulation of bone formation --- p.19 / Chapter 6 --- Effects of systemic hormones and local factors on bone metabolism --- p.20 / Chapter 6.1. --- Parathyroid hormone --- p.20 / Chapter 6.2. --- "1,25-dihydroxyvitamin D3" --- p.22 / Chapter 6.3. --- Calcitonin --- p.23 / Chapter 6.4. --- Prostaglandins --- p.23 / Chapter 6.5. --- Sex hormones --- p.24 / Chapter 6.6. --- Glucocorticoid --- p.26 / Chapter 6.7. --- Growth hormone --- p.27 / Chapter 6.8. --- Insulin --- p.28 / Chapter 6.9. --- Thyroid hormones --- p.29 / Chapter 6.10. --- Other systemic and local factors --- p.30 / Chapter 7 --- Indices of bone turnover --- p.34 / Chapter 8 --- Non-biochemical indices of bone metabolism --- p.34 / Chapter 8.1. --- Radionuclide bone scan --- p.34 / Chapter 8.2. --- Radiokinetic assessment --- p.35 / Chapter 8.3. --- Bone biopsy --- p.35 / Chapter 8.4. --- Bone densitometry --- p.36 / Chapter 9 --- Biochemical indices of bone metabolism --- p.37 / Chapter 10 --- Biochemical markers of bone formation --- p.38 / Chapter 10.1. --- Alkaline phosphatase --- p.38 / Chapter 10.1.1. --- Role and origin of bone alkaline phosphatase isoenzyme --- p.39 / Chapter 10.1.2. --- Measurement of bone alkaline phosphatase --- p.41 / Chapter 10.1.2.1. --- Heat inactivation --- p.42 / Chapter 10.1.2.2. --- Chemical inactivation --- p.43 / Chapter 10.1.2.3. --- Immunological methods --- p.44 / Chapter 10.1.2.4. --- High performance liquid chromatography --- p.45 / Chapter 10.1.2.5. --- Gel electrophoresis --- p.45 / Chapter 10.1.2.6. --- Isoelectric focusing --- p.47 / Chapter 10.2. --- Osteocalcin --- p.48 / Chapter 10.3. --- Osteonectin --- p.51 / Chapter 10.4. --- Matrix Gla-protein --- p.51 / Chapter 10.5. --- Other non-collagenous proteins --- p.52 / Chapter 10.6. --- Urinary Gla concentration --- p.52 / Chapter 10.7. --- Collagen peptides and extension peptides --- p.54 / Chapter 11 --- Biochemical markers of bone resorption --- p.55 / Chapter 11.1. --- Urine hydroxyproline --- p.55 / Chapter 11.2. --- Pyridinium cross-links --- p.58 / Chapter 11.3. --- Acid phosphatase --- p.60 / Chapter 11.3.1. --- Acid phosphatase isoenzymes --- p.60 / Chapter 11.3.2. --- The band 5 acid phosphatase isoenzyme genetics and characteristics --- p.62 / Chapter 11.3.3. --- Band 5 acid phosphatase as marker of osteoclastic function --- p.64 / Chapter 11.3.4. --- Measurement of osteoclastic acid phosphatase --- p.67 / Chapter 11.3.4.1. --- Specific chemical inhibitor --- p.67 / Chapter 11.3.4.2. --- Electrophoresis --- p.67 / Chapter 11.3.4.3. --- Immunological methods --- p.68 / Chapter 12 --- Problems with current biochemical markers of bone metabolism --- p.68 / Chapter 13 --- Aims of this study --- p.70 / Chapter CHAPTER II --- PURIFICATION OF TARTRATE-RESISTANT ACID PHOSPHATASE AND THE DEVELOPMENT OF AN IMMUNOASSAY FOR IT'S MEASUREMENT / Chapter 1 --- Introduction --- p.72 / Chapter 2 --- Materials and methods --- p.75 / Chapter 2.1. --- Chemicals and reagents --- p.75 / Chapter 2.1.1. --- Apparatus --- p.76 / Chapter 2.2. --- Methods --- p.77 / Chapter 2.2.1. --- Cord serum --- p.77 / Chapter 2.2.2. --- Measurement of tartrate-resistant acid phosphatase activity --- p.77 / Chapter 2.2.3. --- Measurement of protein concentration --- p.80 / Chapter 2.2.4. --- Purification of TRACP from cord plasma --- p.82 / Chapter 2.2.4.1. --- Cation-exchange column chromatography --- p.83 / Chapter 2.2.4.2. --- Gel filtration column chromatography --- p.84 / Chapter 2.2.4.3. --- Concanavalin A-affinity column chromatography --- p.85 / Chapter 2.2.4.4. --- Preparative isoelectric focusing (IEF) --- p.86 / Chapter 2.3. --- Characterisation of purified TRACP --- p.90 / Chapter 2.3.1. --- Polyacrylamide gel electrophoresis (PAGE) --- p.91 / Chapter 2.3.2. --- "Optimum pH, substrate specificity and the effects of potential activators and inhibitors on TRACP activity" --- p.99 / Chapter 2.3.3. --- Amino acid composition of purified TRACP --- p.101 / Chapter 2.4. --- Methods for raising anti-human TRACP antibody and characterisation of the antiserum --- p.102 / Chapter 2.4.1. --- Production of rabbit anti-human TRACP antibody --- p.102 / Chapter 2.4.2. --- Determination of the titre of rabbit anti-human TRACP antibody --- p.103 / Chapter 2.4.3. --- Immunoblotting analyses for cross reactivity study --- p.103 / Chapter 2.4.4. --- Immunohistochemical study for antibody specificity --- p.105 / Chapter 2.4.5. --- Cross reactivity study of the rabbit anti-human TRACP antibody to some tissue preparations --- p.107 / Chapter 2.5. --- Enzyme linked immunosorbent assay for TRACP --- p.109 / Chapter 2.5.1. --- Optimisation and evaluation of the new ELISA method for TRACP --- p.111 / Chapter 3 --- RESULTS --- p.113 / Chapter 3.1. --- "Precision of methods for the determination of protein, TRACP and phosphate." --- p.113 / Chapter 3.2. --- Isolation and purification of TRACP --- p.113 / Chapter 3.2.1. --- Concanavalin A affinity chromatography --- p.120 / Chapter 3.2.2. --- Isoelectric focusing (IEF) --- p.120 / Chapter 3.3. --- Characterisation and homogeneity of purified TRACP --- p.128 / Chapter 3.3.1. --- Characterisation of purified TRACP --- p.128 / Chapter 3.3.2. --- Homogeneity of purified TRACP --- p.132 / Chapter 3.3.3. --- Amino acid composition --- p.136 / Chapter 3.4. --- Characterisation of the rabbit anti-human TRACP antibody --- p.136 / Chapter 3.4.1. --- Antibody specificity - immunoblotting study --- p.139 / Chapter 3.4.2. --- Antibody specificity - cross reactivity with partially purified non-cord plasma TRACP --- p.142 / Chapter 3.4.3. --- Antibody specificity - immunohistochemical study --- p.145 / Chapter 3.5. --- Enzyme linked immunosorbent assay for TRACP --- p.145 / Chapter 3.5.1. --- Optimal concentration of antigen for coating of microtitre plate --- p.145 / Chapter 3.5.2. --- Kinetics of reaction with the primary rabbit anti-human TRACP antibody --- p.149 / Chapter 3.5.3. --- "Precision, recovery and assay range" --- p.149 / Chapter 4 --- DISCUSSION --- p.155 / Chapter 4.1. --- Purification of cord plasma TRACP --- p.155 / Chapter 4.2. --- Characterisation of cord plasma TRACP --- p.158 / Chapter 4.3. --- Characterisation of rabbit anti-human TRACP antibody --- p.163 / Chapter 4.4. --- Enzyme immunoassay for TRACP --- p.165 / Chapter CHAPTER III --- STUDY OF SERUM TRACP IN HEALTHY SUBJECTS AND IN PATIENTS WITH BONE RELATED DISEASES / Chapter 1 --- Introduction --- p.168 / Chapter 2 --- Materials and methods --- p.171 / Chapter 2.1. --- Subjects --- p.171 / Chapter 2.1.1. --- Healthy subjects --- p.171 / Chapter 2.1.2. --- Patients --- p.172 / Chapter 2.1.2.1. --- Post-menopausal women on hormone replacement therapy --- p.172 / Chapter 2.1.2.2. --- Hip fracture patients --- p.173 / Chapter 2.1.2.3. --- Other patients --- p.174 / Chapter 2.3. --- Measurement of other biochemical parameters --- p.175 / Chapter 2.3.1. --- Bone alkaline phosphatase --- p.175 / Chapter 2.3.2. --- "Measurement of urine hydroxyproline, creatinine, calcium, osteocalcin, thyroid hormones and parathyroid hormone" --- p.176 / Chapter 2.4. --- Statistics --- p.178 / Chapter 3 --- RESULTS --- p.179 / Chapter 3.1. --- Healthy subjects --- p.179 / Chapter 3.2. --- Serum TRACP concentration in post-menopausal women before and after hormone replacement therapy --- p.185 / Chapter 3.3. --- TRACP concentration in elderly subjects with hip fractures --- p.189 / Chapter 3.4. --- Serum TRACP concentrations in patients with other bone related diseases --- p.190 / Chapter 3.4.1. --- Hyperthyroidism --- p.194 / Chapter 3.4.2. --- Hyperparathyroidism --- p.198 / Chapter 3.4.3. --- Haemodialysis --- p.201 / Chapter 4 --- DISCUSSION --- p.204 / GENERAL DISCUSSION --- p.216 / REFERENCES --- p.219

Vitamin D is a precursor to a steroid hormone, 1,25 dihydroxyvitamin D (1,25(OH)2D). After its discovery and the characterization of its receptor, the vitamin D receptor (VDR), it was initially thought only to be involved in calcium homeostasis, but further research revealed an important role for vitamin D in the regulation of cell growth and differentiation of such cells as osteoblasts and bone marrow adipocytes. 1,25(OH)2D has also been shown to be a strong inhibitor and pro-differentiator of keratinocytes. The anti-proliferative and pro-differentiative properties of this hormone have led to studies where 1,25(OH)2D anticancer properties were assessed and initial findings that showed a requirement of other factors beyond VDR to induce 1,25(OH)2D signaling led to the identification of the retinoid X receptor, a common heterodimeric partner for several hormone receptors. The focus of thesis was to further elucidate the structure-function relationship of both the vitamin D receptor and the retinoid X receptor. Additionally, contributions to work directed towards further identifying the effects of vitamin D on osteoblast differentiation and survival. Interactions of 1,25(OH) 2D3 with its cognate receptor, identifying a key amino acid (Tryptophan 286) required for ligand contact and transcriptional activation, are described in Chapter 2. Mechanisms of vitamin D action on mesenchymal stem cell differentiation, promotion of osteoblast induction and maturation, and inhibition of adipocyte differentiation, are eluicidated in Chapter 3. Chapter 4 illustrates the effects of RAS/RAF/Mitogen-activated protein kinase mediated RXRalpha phosphorylation on the three-dimensional structure of the RXR/nuclear receptor partner heterodimers. Furthermore, this chapter reveals the inhibitory effect of the phosphorylation of a critical amino acid (serine 260) on the interaction of the AF-2 domain of the RXR with several coactivators, resulting in a decrease in the signaling potential of multiple steroid hormone receptors. The findings of this thesis further the knowledge of several areas of vitamin D biology, including both the canonical areas of bone formation, and the non-canonical area of vitamin D and cancer.

Este estudo investigou o efeito da Roziglitazona (RTZ) sobre a perda óssea alveolar induzida pela periodontite (POAIP). Durante 3 semanas, ratos receberam sal puro de RTZ (i.p.) ou a formulaço comercial Avandia<font face=\"Symbol\">&#210; (v.o.); os grupos controles receberam os repectiovos veículos (DMSO ou CMC). Duas semanas após o inicio do tratamento, a periodontite (P) foi induzida. Após 7 dias da indução da P, as mandíbulas foram removidas para mediço da perda óssea alveolar. Amostras de osso alveolar foram analisadas por qPCR para RUNX2, Osterix, TRAF6, TRAF2, RANKL, óxido nítrico sintases (e, n e iNOS) e PPARs (<font face=\"Symbol\">a, <font face=\"Symbol\">b e <font face=\"Symbol\">g). A farmacocinética da RTZ para cada formulaço foi estudada por HPLC-MS/MS. Tanto o sal puro como a formulaço comercial de RTZ resultou no agravamento da POAIP. Apesar dos resultados similares nas concentrações plasmáticas de RTZ os mecanismos de sinalizaço parecem depender da formulaço administrada a qual pode ser devido a interferência do veículo. / This study investigate the effects of rosiglitazone (RTZ) on periodontitis-induced alveolar bone loss (PIABL). Rats received RTZ during 3 weeks, either as the pure maleate salt (i.p.) or the commercial formulation Avandia<font face=\"Symbol\">&#226; (p.o.); control animals received the respective vehicles (DMSO or CMC). Two weeks after the treatments begins, periodontitis (P) were induced. After 7 days after P induction, jaws were removed for ABL measurement. Alveolar bone samples were analyzed by qPCR for RUNX2, Osterix, TRAF6, TRAF2, RANKL, nitric oxide sintase (e, n and iNOS) and PPARs (<font face=\"Symbol\">a, <font face=\"Symbol\">b e <font face=\"Symbol\">g). RTZ pharmacokinetics from each formulation was also studied (HPLC-MS/MS). RTZ, either from the pure maleate salt or the commercial Avandia, resulted in aggravated PIABL. Despite resulting in similar plasma RTZ concentrations, signaling mechanisms seem to depend on the administered formulation which could be due to vehicle related effects interfence.

No description available.

by Warren Tak-keung Lee. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 161-186). / Chapter CHAPTER 1: --- INTRODUCTION --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Objectives --- p.3 / Chapter CHAPTER 2: --- LITERATURE REVIEW --- p.4 / Chapter 2.1 --- Calcium intakes of Hong Kong Chinese: past and present --- p.4 / Chapter 2.1.1 --- Adults --- p.4 / Chapter 2.1.2 --- Children --- p.5 / Chapter 2.2 --- Calcium Metabolism --- p.6 / Chapter 2.2.1 --- Calcium and bone mass --- p.9 / Chapter 2.2.2 --- Ethnicity and bone mass --- p.9 / Chapter 2.2.3 --- Physical activity and bone mass --- p.10 / Chapter 2.2.4 --- Hormonal control of calcium metabolism --- p.11 / Chapter 2.2.5 --- Intestinal calcium absorption --- p.14 / Chapter (1) --- Calcium transport across the intestine / Chapter (2) --- Active Calcium Transport / Chapter (3) --- Passive calcium transport / Chapter (4) --- Age and calcium absorption / Chapter 2.2.6 --- Dietary components in relation to calcium bioavailability and absorption --- p.17 / Chapter (1) --- Habitual calcium intake / Chapter (2) --- Vitamin D nutritional status / Chapter (3) --- Protein / Chapter (4) --- Phosphorous and Ca:P ratio / Chapter (5) --- Sodium / Chapter (6) --- Lactose / Chapter (7) --- Glucose and Glucose Polymers / Chapter (8) --- Phytate / Chapter (9) --- Oxalate / Chapter (10) --- Plant estrogen (phyto-estrogen) / Chapter 2.2.7 --- Bioavailability from calcium salts --- p.23 / Chapter 2.3 --- Calcium intakes and requirements --- p.25 / Chapter 2.3.1 --- Calcium requirements in adulthood --- p.28 / Chapter 2.3.2 --- Calcium requirements in childhood --- p.29 / Chapter 2.3.3 --- Manifestation of calcium deficiency in children --- p.30 / Chapter 2.4 --- Assessment of Dietary Intakes --- p.32 / Chapter 2.4.1 --- Food weighing method --- p.32 / Chapter 2.4.2 --- Food Recording method --- p.34 / Chapter 2.4.3 --- 24-hour dietary recall --- p.35 / Chapter 2.4.4 --- Food frequency method --- p.36 / Chapter 2.4.5 --- Dietary history method --- p.38 / Chapter 2.4.6 --- Chemical analysis of duplicate meals --- p.39 / Chapter 2.4.7 --- Photographic method --- p.40 / Chapter 2.4.8 --- Selecting suitable methods for the present study --- p.40 / Chapter 2.5 --- Food composition database --- p.41 / Chapter 2.6 --- Evaluation of bone mass in vivo --- p.43 / Chapter 2.6.1 --- Single photon absorptiometry --- p.44 / Chapter 2.6.2 --- Dual photon absorptiometry --- p.46 / Chapter 2.6.3 --- Dual energy X-ray absorptiometry --- p.47 / Chapter 2.6.4 --- Quantitative computerized tomography --- p.47 / Chapter 2.6.5 --- The techniques selected to quantify bone mass in the present study --- p.48 / Chapter 2.7 --- Measurement of intestinal calcium absorption --- p.49 / Chapter 2.7.1 --- Metabolic balance study --- p.49 / Chapter 2.7.2 --- Isotopic techniques (radioisotope or stable isotope) --- p.50 / Chapter (1) --- Radio isotope vs stable isotope / Chapter (2) --- The single-label isotope technique / Chapter (3) --- The double-label isotope technique / Chapter (4) --- "Preparation of stable isotopes for human study, and determination of stable isotopes in body fluids" / Chapter (I) --- Dosage considerations / Chapter (II) --- Intrinsic or Extrinsic labelling / Chapter (III) --- Oral and intravenous administration of isotopes / Chapter 2.7.3 --- The technique selected to determine calcium absorption in the present study --- p.60 / Chapter 2.8 --- Mass spectrometry --- p.60 / Chapter 2.8.1 --- Thermal ionization mass spectrometry --- p.60 / Chapter 2.8.2 --- Fast atom bombardment mass spectrometry --- p.61 / Chapter 2.8.3 --- Inductively coupled plasma mass spectrometry --- p.61 / Chapter 2.8.4 --- Electron impact mass spectrometry and Gas chromatography mass spectrometry --- p.62 / Chapter 2.8.5 --- Neutron activation analysis --- p.62 / Chapter 2.8.6 --- The type of mass spectrometry used to determine stable isotopic ratios in the present study --- p.63 / Chapter 2.9 --- Assessment of physical activity in children --- p.63 / Chapter 2.9.1 --- Activity questionnaire or record --- p.64 / Chapter 2.9.2 --- Direct measurement of physical activity --- p.65 / Chapter (1) --- Accelerometer / Chapter (2) --- Pedometer / Chapter (3) --- Actometer / Chapter (4) --- Video-recording / Chapter (5) --- Heart-rate recording / Chapter 2.9.3 --- Selection of a suitable physical activity assessment method --- p.67 / Chapter CHAPTER 3 --- RANDOMIZED DOUBLE-BLIND CONTROLLED CALCIUM SUPPLEMENTATON TRIALS IN RELATION TO BONE AND HEIGHT ACQUISITION IN 7-YEAR OLD CHINESE CHILDREN FROM JIANGMEN (CHINA) AND HONG KONG --- p.71 / Chapter 3.1 --- Chapter summary --- p.71 / Chapter 3.2 --- Chapter Introduction --- p.72 / PART I --- p.73 / Chapter 3.3 --- Double-blind Controlled Randomized Calcium Supplementation and Bone and Height Acquisition in Chinese Children Accustomed to Mean Calcium Intake at About 300mg/d --- p.73 / Chapter 3.3.1 --- Introduction --- p.73 / Chapter 3.3.2 --- Objectives --- p.74 / Chapter 3.3.3 --- Subject and Methods --- p.74 / Chapter 3.3.4 --- Results --- p.81 / Chapter 3.3.5 --- Discussions --- p.83 / Chapter 3.3.6 --- Conclusion --- p.84 / PART II --- p.84 / Chapter 3.4 --- Randomized double-blind controlled calcium supplementation in relation to bone mineral accretion and height increment of Hong Kong Chinese children --- p.84 / Chapter 3.4.1 --- Introduction --- p.84 / Chapter 3.4.2 --- Objectives --- p.85 / Chapter 3.4.3 --- Subjects and Methods --- p.85 / Chapter 3.3.4 --- Results --- p.91 / Chapter 3.4.5 --- Discussions --- p.95 / Chapter 3.4.6 --- Conclusion --- p.97 / Chapter 3.5 --- Comparisons of the two calcium supplementation trials from Jiangmen and Hong Kong --- p.97 / Chapter 3.6 --- Chapter Discussions --- p.99 / Chapter 3.7 --- Chapter Conclusion --- p.103 / Chapter CHAPTER 4 --- TRUE FRACTIONAL CALCIUM ABSORPTION OF CHINESE CHILDREN AND THE EFFECTS OF DOUBLE-BLIND CONTROLLED CALCIUM SUPPLEMENTATION ON CALCIUM ABSORPTION IN CHILDREN MEASURED WITH STABLE ISOTOPES (42Ca and 44Ca) --- p.117 / Chapter 4.1 --- Chapter summary --- p.117 / Chapter 4.2 --- Chapter introduction --- p.118 / PART I --- p.119 / Chapter 4.3 --- True fractional calcium absorption in Chinese children measured with stable isotopes (42Ca and 44Ca) --- p.119 / Chapter 4.3.1 --- Introduction --- p.119 / Chapter 4.3.2 --- Objectives --- p.120 / Chapter 4.3.3 --- "Subjects, Materials and Methods" --- p.120 / Chapter 4.3.4 --- Results --- p.127 / Chapter 4.3.5 --- Discussions & Conclusion --- p.131 / Part II --- p.131 / Chapter 4.4 --- Effects of double-blind controlled calcium supplementation on calcium absorption in Chinese children measured with stable isotopes (42Ca and 44Ca) --- p.131 / Chapter 4.4.1 --- Introduction --- p.131 / Chapter 4.4.2 --- Objective --- p.132 / Chapter 4.4.3 --- "Subjects, Materials and Methods" --- p.132 / Chapter 4.4.4 --- Results --- p.135 / Chapter 4.4.5 --- Discussions --- p.137 / Chapter 4.4.6 --- Conclusion --- p.139 / Chapter 4.5 --- Chapter Conclusion and Discussions --- p.140 / Chapter CHAPTER 5 --- GENERAL DISCUSSIONS AND RECOMMENDATIONS FOR FURTHER STUDY --- p.156 / Chapter 5.1 --- Ethnic differences in bone acquisition and calcium absorption --- p.156 / Chapter 5.2 --- Calcium requirements for Chinese children --- p.157 / Chapter 5.3 --- Indications for further studies --- p.158 / REFERENCES --- p.161 / APPENDIXES / PUBLICATIONS

OBJETIVO: Determinar os valores séricos do ligante do receptor do ativador do fator nuclear Kappa B (RANKL) e da osteoprotegerina (OPG) em pacientes com Artrite Idiopática Juvenil de início poliarticular (AIJp) em atividade e avaliar a possível correlação destes valores com a presença radiológica de erosões ósseas. MÉTODOS: Trinta pacientes do sexo feminino com diagnóstico de AIJ de início poliarticular segundo os critérios da ILAR (International League of Associations for Rheumatology) em atividade e trinta crianças saudáveis (controles) pareadas por idade e sexo foram selecionadas consecutivamente para este estudo. Todas as articulações comprometidas foram radiografadas e avaliadas, com especial interesse, para a presença de erosões ósseas. Concentrações séricas do RANKL e OPG foram medidas por enzima-imunoensaio (Biomedica, Vienna, Austria). RESULTADOS: Pacientes com AIJp em atividade apresentaram altos valores séricos de RANKL e menores taxas de OPG/RANKL comparadas com controles [2,90 (0,1-37,4) vs. 0,25 (0,1-5,7) pg/ml, p=0,007 e 21,25 (1,8- 897,6) vs. 347,5 (9-947,8)] pg/ml, p=0,005). Diferentemente, não houve diferença em relação à concentração sérica de OPG quando se comparou os pacientes e controles [55,24 (28,34-89,76) vs. 64,42 (30,68-111,28) pg/ml, p=0,256]. Maiores concentrações de RANKL e menores taxas de OPG/RANKL também foram observadas em pacientes com AIJp em atividade com erosões ósseas comparadas com controles [3,49 (0,1-37,4) vs. 0,25 (0,1-5,7) pg/ml, p=0,0115 e 14,3 (1,8-897.6) vs. 347,5 (9-947,8) p=0,016]. Em contraste, valores séricos de RANKL e a taxa de OPG/RANKL foram semelhantes em pacientes com AIJp sem erosões ósseas comparadas com controles [1,75 (0,1-10,9) vs 0,25 (0,1-5,7) pg/ml, p=0,055 e 29,2 (3,3-756,8) vs. 347,5 (9- 947,8), p=0,281]. CONCLUSÃO: Estes dados sugerem que pacientes com AIJp em atividade com erosões ósseas apresentam altos valores séricos de RANKL e baixa taxa de OPG/RANKL indicando que estas alterações podem refletir o comprometimento ósseo nesta doença. / OBJECTIVE: To determine the serum levels of receptor activator of nuclear factor kB-ligand (RANKL) and osteoprotegerin (OPG) in active polyarticularonset Juvenile Idiopathic Arthritis patients (pJIA) and evaluate its possible correlation with bone erosions on the X-ray. METHODS: Thirty female girls with active pJIA diagnosis according ILAR criteria (International League of Associations for Rheumatology) and 30 healthy children gender and agematched controls were consecutively selected for this study. All involved articulations were evaluated by X-ray and analyzed for the presence of bone erosions. The serum levels of RANKL and OPG were measured using an enzyme-linked immunosorbent (Biomedica, Vienna, Austria). RESULTS: Results: Patients with active pJIA had higher levels of serum RANKL and lower OPG/RANKL ratio compared to controls [2.90 (0.1-37.4) vs. 0.25 (0.1- 5.7) pg/ml, p=0.007] and 21.25 (1.8-897.6) vs. 347.5 (9-947.8) pg/ml, p=0.005]. However, levels of OPG were comparable in both groups [55.24 (28.34-89.76) vs. 64.42 (30.68-111.28) pg/ml, p=0.256]. Higher levels of serum RANKL and lower OPG/RANKL ratio was also observed in active pJIA patients with bone erosions compared to controls [3.49 (0.1-37.4) vs. 0.25 (0.1-5.7) pg/ml, p=0.0115 and 14.3 (1.8-897.6) vs. 347.5 (9-947.8), p=0.016]. In contrast, RANKL levels and OPG/RANKL ratio were alike in pJIA patients without bone erosion and controls [1.75 (0.1-10.9) vs. 0.25 (0.1- 5.7) pg/ml, p=0.055 and 29.2 (3.3-756.8) vs. 347.5 (9-947.8), p=0.281]. CONCLUSION: These data suggest that active pJIA with bone erosion is associated with high serum levels of RANKL and low OPG/RANKL ratio indicating that these alterations may reflect bone damage in this disease.

OBJETIVO: Determinar os valores séricos do ligante do receptor do ativador do fator nuclear Kappa B (RANKL) e da osteoprotegerina (OPG) em pacientes com Artrite Idiopática Juvenil de início poliarticular (AIJp) em atividade e avaliar a possível correlação destes valores com a presença radiológica de erosões ósseas. MÉTODOS: Trinta pacientes do sexo feminino com diagnóstico de AIJ de início poliarticular segundo os critérios da ILAR (International League of Associations for Rheumatology) em atividade e trinta crianças saudáveis (controles) pareadas por idade e sexo foram selecionadas consecutivamente para este estudo. Todas as articulações comprometidas foram radiografadas e avaliadas, com especial interesse, para a presença de erosões ósseas. Concentrações séricas do RANKL e OPG foram medidas por enzima-imunoensaio (Biomedica, Vienna, Austria). RESULTADOS: Pacientes com AIJp em atividade apresentaram altos valores séricos de RANKL e menores taxas de OPG/RANKL comparadas com controles [2,90 (0,1-37,4) vs. 0,25 (0,1-5,7) pg/ml, p=0,007 e 21,25 (1,8- 897,6) vs. 347,5 (9-947,8)] pg/ml, p=0,005). Diferentemente, não houve diferença em relação à concentração sérica de OPG quando se comparou os pacientes e controles [55,24 (28,34-89,76) vs. 64,42 (30,68-111,28) pg/ml, p=0,256]. Maiores concentrações de RANKL e menores taxas de OPG/RANKL também foram observadas em pacientes com AIJp em atividade com erosões ósseas comparadas com controles [3,49 (0,1-37,4) vs. 0,25 (0,1-5,7) pg/ml, p=0,0115 e 14,3 (1,8-897.6) vs. 347,5 (9-947,8) p=0,016]. Em contraste, valores séricos de RANKL e a taxa de OPG/RANKL foram semelhantes em pacientes com AIJp sem erosões ósseas comparadas com controles [1,75 (0,1-10,9) vs 0,25 (0,1-5,7) pg/ml, p=0,055 e 29,2 (3,3-756,8) vs. 347,5 (9- 947,8), p=0,281]. CONCLUSÃO: Estes dados sugerem que pacientes com AIJp em atividade com erosões ósseas apresentam altos valores séricos de RANKL e baixa taxa de OPG/RANKL indicando que estas alterações podem refletir o comprometimento ósseo nesta doença. / OBJECTIVE: To determine the serum levels of receptor activator of nuclear factor kB-ligand (RANKL) and osteoprotegerin (OPG) in active polyarticularonset Juvenile Idiopathic Arthritis patients (pJIA) and evaluate its possible correlation with bone erosions on the X-ray. METHODS: Thirty female girls with active pJIA diagnosis according ILAR criteria (International League of Associations for Rheumatology) and 30 healthy children gender and agematched controls were consecutively selected for this study. All involved articulations were evaluated by X-ray and analyzed for the presence of bone erosions. The serum levels of RANKL and OPG were measured using an enzyme-linked immunosorbent (Biomedica, Vienna, Austria). RESULTS: Results: Patients with active pJIA had higher levels of serum RANKL and lower OPG/RANKL ratio compared to controls [2.90 (0.1-37.4) vs. 0.25 (0.1- 5.7) pg/ml, p=0.007] and 21.25 (1.8-897.6) vs. 347.5 (9-947.8) pg/ml, p=0.005]. However, levels of OPG were comparable in both groups [55.24 (28.34-89.76) vs. 64.42 (30.68-111.28) pg/ml, p=0.256]. Higher levels of serum RANKL and lower OPG/RANKL ratio was also observed in active pJIA patients with bone erosions compared to controls [3.49 (0.1-37.4) vs. 0.25 (0.1-5.7) pg/ml, p=0.0115 and 14.3 (1.8-897.6) vs. 347.5 (9-947.8), p=0.016]. In contrast, RANKL levels and OPG/RANKL ratio were alike in pJIA patients without bone erosion and controls [1.75 (0.1-10.9) vs. 0.25 (0.1- 5.7) pg/ml, p=0.055 and 29.2 (3.3-756.8) vs. 347.5 (9-947.8), p=0.281]. CONCLUSION: These data suggest that active pJIA with bone erosion is associated with high serum levels of RANKL and low OPG/RANKL ratio indicating that these alterations may reflect bone damage in this disease.