No description available.

No description available.

This study was undertaken to evaluate shear, bending, and torsion test procedures on the radius, ulna, humerus, femur, tibia, and tarsometatarsus of 72 week old caged layers. Shear and bending properties were determined to evaluate the effects of juvenile protein feeding sequence, body size, and cage profile on the strength of these bones. Body size affected (P < 0.05) the ultimate shear forces of the femur, tibia, and tarsometatarsus. The ultimate bending force and shear modulus of the tibia were also influenced by body weight (P < 0. 05). Juvenile protein sequence and body weight affected the torque and torsional shear stress of the tibia. No differences were noted in shear and bending strength when bone geometry as well as force was considered. The frequency pattern of the bending fractures occurring in the radius, ulna, femur, and tibia were influenced by juvenile protein feeding sequence (P < 0.05). The bones from the control birds failed in bending due predominantly to a weakness of tensile stresses. The reversal in protein caused the bones to fail due to a combination of tensile and shear stresses. The torsion test of the tibia and radius showed. the failure pattern to follow a 45 degree helix around the diaphysis of the bone which is indicative of tensile failures. The four point bending test was not desireable for determining the modulus of elasticity of poultry bones with a length to diameter ratio less than 10. No correlations were found between shear and bending properties of any of the bones. Similarly, the shear, bending, and torsion properties of the tibia were not related. / Ph. D.

Thesis (MSc)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: Planar bone scintigraphy is highly sensitive but it may not be sensitive enough to detect subtle lesions in complex bony structures such as the spine. The accurate anatomic localisation of lesions in regions such as this is also limited using planar images. Single Photon Emission Computed Tomography (SPECT) results in a higher lesion contrast resulting in an improved sensitivity for the detection of subtle lesions. SPECT also enables improved lesion localisation, often valuable in distinguishing benign from malignant disease in the spine. A number of previous studies have demonstrated that the addition of SPECT of the spine significantly enhances the value of bone scintigraphy for the detection of bone metastases compared to planar imaging alone. These studies were however not done in the African context where patients typically present with more advanced disease. In a retrospective study of 576 patients with known primary tumors sent to our institution for bone scintigraphy for the diagnosis of bone metastases, we evaluated 119 patients in whom both planar imaging and SPECT were obtained. The studies were graded for the probability of metastatic disease, and the number of spinal lesions was determined with and without SPECT. The influence of adding SPECT on the interpretation of the study was determined in terms of the reported probability of metastatic disease, the exclusion and confirmation of metastatic disease, the decisiveness of interpretation, and the number of spinal lesions. The addition of SPEeT resulted in a statistically significant change in the interpretation of studies, although the actual numbers of patients affected were relatively small. SPEeT resulted in a more decisive interpretation of bone scintigraphy. There was a significant increase in the number of spinal lesions detected after the addition of SPEeT. It was concluded that although the use of SPEeT is ideal, acceptable results could be achieved using planar imaging alone in this patient population. This is particularly relevant in the African context, where SPEeT is often unavailable or scarce and in great demand. / AFRIKAANSE OPSOMMING: Planare beenflikkergrafie is hoogs sensitief, maar moontlik nie sensitief genoeg om subtiele letsels in ingewikkelde beenstrukture soos die werwelkolom aan te toon nie. Akkurate anatomiese lokalisasie van letsels in die genoemde strukture is beperk wanneer slegs planare beelde gebruik word. Enkelfoton-uitstraling Rekenaartomografie (EFERT) lewer 'n hoër letsel kontras, wat 'n verbeterde sensitiwiteit vir die opsporing van subtiele letsels tot gevolg het. EFERT lei ook tot verbeterde letsel lokalisasie, wat dikwels van waarde is om onderskeid tussen benigne en maligne siekte in die werwelkolom te tref. Reeds met 'n aantal vorige studies is aangetoon dat die toevoeging van EFERT van die werwelkolom die waarde van beenflikkergrafie in die opsporing van beenmetastases beduidend verhoog bo dié van planare beelding alleenlik. Hierdie studies is egter nie in omstandighede eie aan Afrika gedoen nie, waar pasiënte kenmerkend met gevorderde siekte voordoen. In In terugskouende studie van 576 pasiënte met bekende primêre tumore, wat na ons instelling verwys is vir beenflikkergrafie om beenmetastases op te spoor, het ons 119 pasiënte, wat beide planare beelding en EFERT ondergaan het, ge-evalueer. Die studies is gegradeer volgens die waarskynlikheid vir metastatiese siekte, en die hoeveelheid werwelkolom letsels, met en sonder EFERT, is bepaal. Die invloed van EFERT op die vertolking van die studie is bepaal in terme van die waarskynlikheid van metastatiese siekte, die bevestiging en uitskakeling daarvan, die beslistheid van vertolking, en die hoeveelheid werwelkolom letsels. Die toevoeging van EFERT het tot 'n statisties beduidende verandering in die vertolking van studies gelei, alhoewel die werklike getal pasiënte wat hierdeur geraak is, relatief min was. EFERT het 'n meer besliste vertolking van beenflikkergrafie tot gevolg gehad. Daar was 'n beduidende toename in die hoeveelheid werwelkolom letsels wat opgespoor is na die toevoeging van EFERT. Daar is tot die slotsom gekom dat, alhoewel die gebruik van EFERT wenslik is, aanvaarbare resultate met slegs die gebruik van planare beelding in hierdie pasiënt bevolkingsgroep verkry kan word. Dit is veral van belang in Afrikaomstandighede, waar EFERT dikwels onbeskikbaar of skaars is, en ook in groot aanvraag is.

骨科醫生面臨著老年婦女的骨修復受損或者癒合延遲的挑戰，這使得康復過程變長，甚至引發高死亡率。至今為止，臨床上仍然沒有促進老年骨癒合的滿意治療方法，因此亟需其他治療策略。骨癒合重現了胚胎後的骨骼發育過程。直接由骨外膜成骨（膜內骨化）以及通過軟骨介質成骨（軟骨內骨化）是骨癒合中的兩個重要過程。 雌激素受體β（ERβ基因敲除雌性小鼠的研究表明ERβ信號通路在骨骼發育過程中同時參與了抑制膜內骨化和軟骨內骨化這兩個過程。臨床活檢的資料顯示，在絶經後婦女的骨痂中，ERβ陽性的增生軟骨細胞數量增加。然而，ERβ在正常和老年骨癒合的作用還沒有研究。 / 本研究通過下述部分檢查了ERβ在正常和老年骨癒合的作用，以及其將來的藥物應用：1) 建立一個以膜內骨化為主的骨癒合模型。2) 通過連個骨癒合模型，檢查ERβ在正常骨癒合中的作用。3) 檢查ERβ在老年骨癒合中的作用並檢查ERβ拮抗劑PHTPP 對老年骨癒合的潛在藥物療效。 / 實驗1是建立一個以膜內骨化為主的骨癒合模型。以前建立的小鼠股骨中段骨折模型是軟骨內骨化為主的骨癒合模型。由於技術難度，該模型可重複性不高，而且其金屬內固定器會造成金屬偽影，進而不能應用高解析度微焦點CT跟蹤觀察的技術。為了檢查ERβ在膜內骨化中的作用，並且應用微焦點CT跟蹤觀察技術，我們首先建立了一個小鼠鑽孔缺損模型。該實驗同時也確認了去勢誘導的骨質疏鬆小鼠相比正常小鼠，在鑽孔缺損模型中骨癒合受阻。 / 實驗2檢驗了阻斷ERβ能促進正常骨癒合的假設。本實驗應用ERβ基因敲除小鼠，在兩個模型中檢驗了實驗假設。第一個是傳統的小鼠股骨中段骨折模型，第二個是由實驗1建立的鑽孔缺損模型。兩個模型都證實ERβ基因敲除小鼠骨癒合和野生型小鼠相比，早期的血管新生和中期的礦化有所增強，末期的骨癒合沒有明顯差異。 / 實驗3 進一步研究ERβ在老年骨癒合中的作用。實驗應用老年小鼠股骨中段骨折模型，比較ERβ基因敲除小鼠和野生型小鼠之間的癒合過程。結果顯示ERβ基因敲除小鼠骨癒合和野生型小鼠相比，早期的血管新生，中期的礦化以及末期的力學性能都有所增強。該結果預示阻斷ERβ能作為另一種治療老年骨折癒合的治療策略。同時，我們也檢測了ERβ的拮抗劑PHTPP（4 - [2 - 苯基- 5,7 -二（三氟甲基）吡唑並[1,5 - A]嘧啶3 - 基]苯酚, 在老年骨癒合中的治療效果。 通過比較用藥組小鼠與安慰劑組小鼠的骨癒合品質，顯示PHTPP治療小鼠血管新生，骨痂礦化和最終的力學性質均優於對照安慰劑組小鼠。 / 綜上所述，本研究描述了ERβ在正常和老年骨癒合中的作用。骨癒合的關鍵過程包括血管新生，膜內骨化以及軟骨內骨化在阻斷ERβ後都得到增強，從而加快正常骨和老年骨的骨痂形成，礦化並增強力學性質。ERβ的拮抗劑PHTPP在老年小鼠骨折模型中能促進骨癒合。本研究提出了一個新的骨癒合治療策略，並為將來的臨床實驗提供了堅實的基礎。 / Orthopaedic surgeons are challenged by impaired or delayed bone healing in elderly women, which requires prolongation of rehabilitation process or even induces high mortality. Up to date, there are no satisfactory therapeutic modalities for promoting aged bone healing clinically, and alternative therapeutic stratagem is therefore desirable. Bone healing recapitulates postnatal bone development. Direct periosteam-dependent bone formation (intramembranous ossification) and the formation of bone through a cartilage intermediate (endochondral ossification) are the two important processes during bone healing. Evidences from Estrogen Receptor β (ERβ), gene knockout female mouse studies have demonstrated that ERβ signaling participates in inhibiting both intramembranous and endochondral ossification during bone development. Clinical biopsy data demonstrated that the number of ERβ positive proliferative chondrocytes within fracture callus was increased in postmenopausal women. However, the role of ERβ in normal and aged bone healing is not examined yet. / This study examined role of ERβ in normal and aged bone healing and the future pharmaceutical application though the following part: 1) Establish an intramembranous ossification-dominant bone healing model. 2) Examine the role of ERβ in normal bone healing though two models. 3) Examine the role of ERβ in aged bone healing and investigate the potential therapeutical efficacy of an ERβ antagonist PHTPP in aged bone healing. / Study I was to establish an intramembranous ossification dominant bone healing mouse model. Previous available mouse femoral shaft fracture model was a endochondral ossification dominant bone healing model. This model was technically difficult to generate high reproducibility and the inside metal stabilization devices prevented the application of high-resolution in vivo micro-CT monitoring due to the metal artifact. In order to examine the role of ERβ in intramembranous ossification and apply the micro-CT monitoring technique, a drill-hole defect mouse model was developed. The study also confirmed bone healing was impaired in mice with ovariectomy -induced osteoporosis in drill-hole defect model. / Study II was to test the hypothesis that blockade of ERβ could promote normal bone healing. ERβ knockout mice were employed in this study and the hypothesis was examined in two models, the first is the traditional mouse femoral shaft fracture model, and the second is the drill-hole defect model that was developed in study I. Both models demonstrated that the bone healing in ERβ knockout mice was enhanced in the early stage of neovascularization and the middle stage of ossification but not by the end of healing compare to the wild type mice. / Study III was designed to further investigate the role of ERβ in aged bone healing. Femoral shaft fracture model was created in aged mice. The healing process was compared between the ERβ knockout mice and wild type mice. The results demonstrated that ERβ knockout mice was enhanced in the early stage of neovascularization, the middle stage of ossification and end stage of mechanical strength. The findings implied blockade of ERβ can be considered as another therapeutic strategy for aged fracture healing. PHTPP (4-[2-Phenyl-5,7-bis(trifluoromethyl)pyrazolo[1,5-a]pyrimidin-3-yl] phenol), an ERβ antagonist, was employed in aged mice femoral shaft fracture model. The bone healing quality of treated mice was compared with that of the vehicle control mice. It showed PHTPP treated mice had enhanced neovascularization, callus ossification and finally better mechanical properties than vehicle mice. / The present study depicted the role of ERβ in normal and aged bone healing. Key processes including neovascularization, intramembranous and endochondral ossification were all enhanced by blockade of ERβ, which led to fast callus formation, mineralization in normal bone and better mechanical properties in aged bone. ERβ antagonist PHTPP could promote aged bone healing in mouse osteotomy model. This study raised an alternative therapeutic stratagem for bone healing and provided solid basis for future clinical trials. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / He, Yixin. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 147-167). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / ABSTRACT --- p.i / 中文摘要 --- p.iv / PUBLICATIONS AND AWARDS --- p.vi / ACKNOWLEDGEMENTS --- p.xi / TABLE OF CONTENTS --- p.xii / LIST OF ABBREVIATIONS --- p.xvi / LIST OF FIGURES --- p.xviii / LIST OF TABLES --- p.xx / Chapter CHAPTER 1 --- INTRODUCTION AND LITERATURE REVIEW --- p.1 / Chapter 1.1 --- Fracture and Bone Healing --- p.2 / Chapter 1.1.1 --- Epidemiology and Impacts of Fractures --- p.2 / Chapter 1.1.2 --- Current Management and Limitations --- p.3 / Chapter 1.1.3 --- Bone Structures --- p.5 / Chapter 1.1.4 --- Bone Healing --- p.7 / Chapter 1.1.5 --- Aged Bone Healing --- p.12 / Chapter 1.1.6 --- Enhancements of Bone Healing --- p.17 / Chapter 1.2 --- Estrogen and Estrogen Receptors --- p.19 / Chapter 1.2.1 --- Estrogen Receptors α and β --- p.19 / Chapter 1.2.2 --- Molecular Actions of Estrogens --- p.20 / Chapter 1.2.3 --- Estrogen receptors in bone homeostasis --- p.24 / Chapter 1.3 --- Hypothesis --- p.28 / Chapter 1.4 --- Study Plan and Objectives --- p.32 / Chapter 1.4.1 --- Bone Healing Models --- p.32 / Chapter 1.4.2 --- Study Outline --- p.32 / Chapter 1.5 --- Figures and Tables --- p.34 / Chapter CHAPTER 2 --- ESTABLISHMENT OF DRILL-HOLE DEFECT HEALING MODEL IN MICE --- p.39 / Chapter 2.1 --- Introduction --- p.40 / Chapter 2.1.1 --- Limitations in currently available mouse models of osteoporotic bone healing --- p.40 / Chapter 2.1.2 --- Creation of a drill-hole defect at the mid-diaphysis of the femur for in vivo monitoring of bone healing in mice --- p.40 / Chapter 2.2 --- Materials and Methods --- p.43 / Chapter 2.2.1 --- Experimental animals --- p.43 / Chapter 2.2.2 --- Surgical protocol and experimental design --- p.43 / Chapter 2.2.3 --- Micro-CT analysis of intact femur --- p.44 / Chapter 2.2.4 --- In vivo micro-CT analysis of new bone formation in the drill-hole site --- p.45 / Chapter 2.2.5 --- Micro-CT-based angiography --- p.45 / Chapter 2.2.6 --- Histological examination --- p.46 / Chapter 2.2.7 --- Immunohistochemistry --- p.46 / Chapter 2.2.8 --- Quantitative real-time PCR --- p.47 / Chapter 2.2.9 --- Analysis of bone formation and resorption markers --- p.47 / Chapter 2.2.10 --- Mechanical testing --- p.48 / Chapter 2.2.11 --- Statistical analysis --- p.48 / Chapter 2.3 --- Results --- p.51 / Chapter 2.3.1 --- Confirmation of osteoporotic bone prior to generation of a drill-hole defect --- p.51 / Chapter 2.3.2 --- General observation of mice following drill-hole surgery --- p.51 / Chapter 2.3.3 --- In vivo micro-CT analysis of new bone in the drill-hole site of mouse femurs --- p.51 / Chapter 2.3.4 --- In vivo micro-CT analysis of new bone in drill-hole sites is highly reproducible --- p.52 / Chapter 2.3.5 --- Micro-CT angiography --- p.52 / Chapter 2.3.6 --- Histological observation of bone healing --- p.53 / Chapter 2.3.7 --- Immunohistochemical analysis of ER expressions during bone healing --- p.54 / Chapter 2.3.8 --- Quantitative real-time PCR analysis of gene expression during bone healing --- p.54 / Chapter 2.3.9 --- Analysis of bone formation and resorption markers during bone healing --- p.54 / Chapter 2.3.10 --- Mechanical testing of femurs from Sham and OVX mice --- p.55 / Chapter 2.4 --- Discussion --- p.56 / Chapter 2.4.1 --- Bone healing with dominant intramembranous ossification --- p.56 / Chapter 2.4.2 --- Impaired osteoporotic bone healing --- p.57 / Chapter 2.4.3 --- Reproducibility of the in vivo micro-CT method for analysis of bone healing --- p.58 / Chapter 2.4.4 --- Dysregulated expression of estrogen receptors and bone healing in OVX mice --- p.59 / Chapter 2.4.5 --- Study limitations --- p.60 / Chapter 2.4.6 --- Conclusions --- p.60 / Chapter 2.5 --- Figures and Tables --- p.61 / Chapter CHAPTER 3 --- ROLE OF ERβ IN NORMAL BONE HEALING --- p.72 / Chapter 3.1 --- Introduction --- p.73 / Chapter 3.2 --- Materials and Methods --- p.75 / Chapter 3.2.1 --- Part I Study --- p.75 / Chapter 3.2.1.1 --- Experimental animals --- p.75 / Chapter 3.2.1.2 --- Fracture model and experimental design --- p.75 / Chapter 3.2.1.3 --- Radiographic Analysis --- p.76 / Chapter 3.2.1.4 --- Micro-CT-based angiography --- p.76 / Chapter 3.2.1.5 --- Micro-CT analysis of callus --- p.77 / Chapter 3.2.1.6 --- Histological examination --- p.78 / Chapter 3.2.1.7 --- Dynamic Bone histomorphometric analysis --- p.78 / Chapter 3.2.1.8 --- Mechanical testing --- p.79 / Chapter 3.2.1.9 --- Quantitative real-time PCR --- p.80 / Chapter 3.2.1.10 --- Analysis of bone formation and resorption markers --- p.80 / Chapter 3.2.1.11 --- Statistical analysis --- p.81 / Chapter 3.2.2 --- Part II Study --- p.81 / Chapter 3.2.2.1 --- Experimental animals and design --- p.81 / Chapter 3.2.2.2 --- Evaluation protocols --- p.82 / Chapter 3.2.2.3 --- Statistical analysis --- p.82 / Chapter 3.3 --- Results --- p.83 / Chapter 3.3.1 --- Part I Study --- p.83 / Chapter 3.3.1.1 --- Radiographic Analysis --- p.83 / Chapter 3.3.1.2 --- Micro-CT angiography --- p.83 / Chapter 3.3.1.3 --- Micro-CT analysis of callus --- p.83 / Chapter 3.3.1.4 --- Histological and dynamic histomorphometric analysis --- p.84 / Chapter 3.3.1.5 --- Mechanical testing of the callus --- p.85 / Chapter 3.3.1.6 --- Quantitative real-time PCR analysis of gene expression --- p.85 / Chapter 3.3.1.7 --- Analysis of bone formation and resorption markers during bone healing --- p.85 / Chapter 3.3.2 --- Part II Study --- p.86 / Chapter 3.3.2.1 --- In vivo micro-CT analysis of new bone in the drill-hole site of mouse femurs --- p.86 / Chapter 3.3.2.2 --- Micro-CT angiography --- p.87 / Chapter 3.3.2.3 --- Histological observation of bone healing --- p.87 / Chapter 3.3.2.4 --- Quantitative real-time PCR analysis of gene expression --- p.88 / Chapter 3.3.2.5 --- Analysis of bone formation and resorption markers during bone healing --- p.88 / Chapter 3.3.2.6 --- Mechanical testing of femurs from WT and KO mice --- p.88 / Chapter 3.4 --- Discussion --- p.90 / Chapter 3.4.1 --- Angiogenesis --- p.90 / Chapter 3.4.2 --- Fracture Healing --- p.91 / Chapter 3.4.3 --- Estrogen receptor β and endochondral and intramembranous ossification --- p.93 / Chapter 3.4.4 --- Estrogen receptor β in aged bone --- p.94 / Chapter 3.4.5 --- Conclusions --- p.94 / Chapter 3.5 --- Figures and Tables --- p.95 / Chapter CHAPTER 4 --- ROLE OF ERβ AND ITS ANTAGONIST PHTPP IN AGED BONE HEALING --- p.113 / Chapter 4.1 --- Introduction --- p.114 / Chapter 4.2 --- Materials and Methods --- p.116 / Chapter 4.2.1 --- Experimental animals --- p.116 / Chapter 4.2.2 --- Fracture model and experimental design --- p.116 / Chapter 4.2.3 --- Radiographic Analysis --- p.117 / Chapter 4.2.4 --- Micro-CT-based angiography --- p.118 / Chapter 4.2.5 --- Micro-CT analysis of callus --- p.118 / Chapter 4.2.6 --- Histological examination --- p.119 / Chapter 4.2.7 --- Dynamic Bone histomorphometric analysis --- p.120 / Chapter 4.2.8 --- Mechanical testing --- p.120 / Chapter 4.2.9 --- Quantitative real-time PCR --- p.121 / Chapter 4.2.10 --- Analysis of bone formation and resorption markers --- p.122 / Chapter 4.2.11 --- Statistical analysis --- p.122 / Chapter 4.3 --- Results --- p.123 / Chapter 4.3.1 --- Radiographic Analysis --- p.123 / Chapter 4.3.2 --- Micro-CT angiography --- p.123 / Chapter 4.3.3 --- Micro-CT analysis of callus --- p.123 / Chapter 4.3.4 --- Histological and dynamic histomorphometric analysis --- p.124 / Chapter 4.3.5 --- Mechanical testing of the callus --- p.125 / Chapter 4.3.6 --- Quantitative real-time PCR analysis of gene expression during fracture healing --- p.125 / Chapter 4.3.7 --- Analysis of bone formation and resorption markers during bone healing --- p.126 / Chapter 4.4 --- Discussion --- p.127 / Chapter 4.4.1 --- Angiogenesis --- p.127 / Chapter 4.4.2 --- Fracture Healing --- p.128 / Chapter 4.4.3 --- Estrogen receptor β and endochondral ossification --- p.129 / Chapter 4.4.4 --- ERβ antagonist PHTPP --- p.130 / Chapter 4.4.5 --- Conclusions --- p.130 / Chapter 4.5 --- Figures and Tables --- p.131 / Chapter CHAPTER 5 --- STUDY LINITATIONS, FURTHER RESEARCH AND CONCLUDSIONS --- p.142 / Chapter 5.1 --- Limitations --- p.143 / Chapter 5.1.1 --- Bone healing model --- p.143 / Chapter 5.1.2 --- Estrogen receptors and transgenic mouse --- p.143 / Chapter 5.1.3 --- ERβ antagonist PHTPP --- p.144 / Chapter 5.2 --- Further Research --- p.144 / Chapter 5.2.1 --- ERβ signaling --- p.144 / Chapter 5.2.2 --- Preclinical Trial --- p.145 / Chapter 5.3 --- Conclusions --- p.146 / BIBLIOGRAPHY --- p.147

骺軟骨板是位於長骨骨骺的一個軟骨結構，其主要功用為使骨骼延伸生長。 若人類骺軟骨板基因出現障礙，骨骼生長往往會受到嚴重的影響，使骨骼變得短小、畸形，造成殘障。此外，一些後天的系統性失調也會損害骺軟骨板的正常運作，導致矮小症。現今常用來醫治骨骼生長障礙的包括重組的人類生長荷爾蒙。然而，它的功效並非顯著，亦帶來很多的副作用；因此，我們希望能尋求更好的醫治方法。 / 近有的研究結果顯示，很多的內分泌及分泌因子能夠刺激骺軟骨板進行軟骨增生。但是，研究者卻往往未能將這些因子轉化及運用作醫療用途，原因是它們通常都是局部性地於骺軟骨板產出及發生效用。倘若以上提及的生長因子能給骺軟骨板的靶子蛋白鏈準確地被帶往骺軟骨板，那麼這些因子便能有效地被利用作治療用途，而其效能亦會給大大提高，副作用也會被減低。因此，我們現在進行研究的首要目標為於採用噬菌體展示和酵母展示方法， 尋找那些能認辨出骺軟骨板的靶子蛋白鏈及單鏈抗體。 / 於噬菌體展示庫裡，我們找出了兩條能認辨出小鼠骨骼軟骨細胞的靶子蛋白鏈 － C1 (RLDPTSYLRTFW) 和 C19 (HDSQLEALIKFM)。然而於體外測試實驗中， 它們對軟骨細胞及細胞外基質只擁有中度的親近性和特異性。此後，於酵母展示庫裡，我們亦發現三條可認辨某骺軟骨板蛋白的單鏈抗體 － 它們的親近性甚高 (達至1 nM)，而其對軟骨組織的特異性也為良好 (它們只認辨軟骨組織，但卻沒能認辨出其他的軟組織，包括腦、心臟、肝臟、肺臟、腎臟、脾臟、小腸及肌肉)。 其後，於小鼠胚胎免疫染色測試實驗中，這些單鏈抗體只亦選擇地認辨軟骨組織。再者，當這些單鏈抗體被注射入小鼠的靜脈中，它們也會準確地停留在軟骨組織裡，顯示出其特異性於體內測試實驗中亦存在。 / 總括而言，利用噬菌體展示和酵母展示方法，我們發現了一些能認辨出骺軟骨板的靶子蛋白鏈及單鏈抗體。這些單鏈抗體擁有對軟骨組織非常高的親近性和特異性。我們預計，若然將這些單鏈抗體和內分泌及分泌因子連結在一起，它們或能成為醫治骨骼生長障礙的新方法。 / The growth plate is a specialized cartilage structure at the ends of long bones that is responsible for bone elongation. Many human genetic disorders of the growth plate impair skeletal growth, often resulting in bones that are severely short and malformed, causing serious disability. Many acquired systemic disorders also impair growth plate function, causing short stature. Currently, recombinant human growth hormone is used to treat growth disorders, but it has limited efficacy for severe diseases and causes significant adverse effects. / Recent studies have identified many endocrine and paracrine factors that are capable of promoting chondrogenesis at the growth plate. However, the development of these molecules into effective therapies has been hampered by their action mechanism; they are produced locally and act locally in the growth plate and thus fail to lend themselves to systemic therapeutic approaches. We envisioned that, if these growth factors could be linked to growth plate-targeting peptides or polypeptides and then administered systemically, these molecules might provide a better treatment strategy for growth disorders because targeting might augment the therapeutic effect on the growth plate but diminish undesirable effects on non-target tissues. Toward this goal, we sought to identify peptides and antibody fragments that bind to cartilage tissue using phage display and yeast display technologies. / We used a phage display library that expressed linear peptides of 12 random amino acids on the phage surface and then selected for binding to murine primary cultured chondrocytes. This approach successfully identified two peptides, namely C1 (RLDPTSYLRTFW) and C19 (HDSQLEALIKFM), which exhibited moderate binding affinity and specificity to chondrocytes and extracellular matrix in vitro. We also used a yeast display library to identify three single-chain variable(scFv) antibody fragments that bound strongly to a growth plate-specific protein(EC50 values less than 1 nM). These antibody fragments demonstrated specific binding in vitro to homogenates of cartilage tissues, but not homogenates of brain, heart, liver, lung, kidney, spleen, small intestine, or muscle. Moreover, they also exhibited tissue-specific binding to cartilage structures in sections of mouse embryos. When these purified antibody fragments were injected intravenously in mice, they localized to cartilage and were not detectable in other tissues, including brain, heart, liver, lung, kidney, spleen, small intestine, or muscle, indicating that the antibody fragments were capable of specifically targeting cartilage tissue in vivo. / In conclusion, we employed phage display and yeast display methods to identify peptides and antibody fragments that bind to cartilage tissues. The selected antibody fragments showed particularly high binding affinity and specificity to cartilage. Conjugating these antibody fragments to endocrine and paracrine signaling molecules has the potential to provide targeted therapy for growth plate disorders. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Cheung, Sao Fong. / Thesis (Ph.D.) Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 89-102). / Abstracts also in Chinese.

[Truncated abstract] Osteoclasts are multinucleated giant cells responsible for the resorption of the mineralized bone matrix during the process of bone remodelling. During activation towards bone resorption, polarization of the osteoclast results in the formation of a unique plasma membrane, the ruffled border, the actual resorptive organelle of the osteoclast. Through this domain protons are actively pumped into the resorption lacuna creating an acidic microenvironment that favours the dissolution of the mineralized bone matrix. The polarised secretion of protons is carried out by the action of the vacuolar-type (H+)-ATPase (V-ATPase), composed of functionally and structurally distinct subunits of the V1 and V0 domains. The general structure of the V-ATPase complex is highly conserved from yeast to mammals, however, multiple isoforms for specific V-ATPase subunits do exist exhibiting differential subcellular, cellular and tissue-specific localizations. This study focuses on the molecular identification and characterization of V-ATPase accessory subunit Ac45 and the d2 isoform of the V0 domain d subunit in osteoclasts. Using the techniques of cDNA Subtractive Hybridization and DNA Micro-Array analyses respectively, the accessory subunit Ac45 and the d2 isoform of the V0 domain d subunit were identified in RAW264.7-cells derived OcLs. ... Using web-based computational predictions, two possible transmembrane domains, an N-terminus 'signal anchor' sequence and a C-terminus dilysine- like endoplasmic reticulum (ER) retention signal were identified. By confocal microscopy, EYFP-tagged e was found to localize to the perinuclear region of transfected COS-7 cells in compartments representing the ER and Golgi apparatus with some localization in late endosomal/lysosomal-like vesicles. ER truncation of e did not alter its subcellular localization but exhibited significantly weaker association with Ac45 compared to the wild-type as depicted by BRET analyses. Association with the other V0 subunits remain unaffected. This may hint at a possibility that Ac45 may play a role in the masking of the ER signal of e following it's incorporation into the V0 domain. Although no solid evidence for a role in the assembly of the mammalian VATPase have been established, subunit e still represents a potential candidate whose role in the V-ATPase complex requires further investigation. Collectively, the data presented in this thesis has provided further insight into the composition of the osteoclast V-ATPase proton pump by: 1) identifying an accessory subunit, Ac45 which shows promise as a potential candidate for the regulation and/or targeting of the V-ATPase complex in osteoclasts and truncation of its targeting signal impairs osteoclastic bone resorption; 2) identification and preliminary characterization of the d2 isoform of the V0 domain d subunit whose exact role in the V-ATPase complex and in osteoclasts remains to be determined, although its has been implicated to be essential for osteoclastic function; and 3) Preliminary characterization of subunit-e, a potential assembly factor candidate for the mammalian V-ATPase V0 domain.

Although there are now many theories describing empirical relationships between strength properties of bone and various explanatory variables, the need for improved non-invasive diagnostic techniques to assess bone fragility is of core importance in clinical problems such as osteoporosis. The aim of this thesis was to develop non-invasive radiological methods to assess trabecular bone architecture. Measures of structural anisotropy and bone structure from X-ray or radiological projections have been developed. The first measure, the projected mean intercept length (PMIL), allows extraction of the total bone surface (BS/TV) and the mean intercept length (MIL) from projections of trabecular structure. The second measure, the line projection deviation (LPD), is a technique that quantifies the preferential alignment of trabecular bone from projections of the trabecular structure. Hence, in combination, the PMIL and LPD allow non-invasive extraction of BS/TV and more detailed preferential alignment from projections of the trabecular structure. In this thesis the PMIL and LPD are introduced and their properties explored. The PMIL and LPD are used to examine the anisotropy and architectural properties of a number of human vertebral body trabecular bone samples. When used in combination with clinical densitometry, these measures improve explanation of the variance in strength, elastic modulus and toughness of vertebral body trabecular bone samples by up to 40% when compared to densitometric values alone. While µCT can provide the information needed to access trabecular architecture, it cannot be used in clinical settings since its high radiation dose makes it only applicable to small objects ex-vivo. At present, clinically available CT does not provide sufficient resolution to resolve trabecular structures. Thus, the methods described in this thesis will allow estimates of structural parameters from plain X-rays, providing for the first time, the possibility of clinical use of such estimates. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1311218 / Thesis (Ph.D.) -- School of Medical Sciences, 2008

Discordance in bone mass between young adult swimmers and soccer players may be a direct result of differences in bone loading patterns that influence bone mineralization during growth. Our aim was to evaluate whether sports participation (soccer and swimming) had an independent effect on bone mass accrual at the hip and lumbar spine in adolescent female athletes. We recruited boys and girls 10 to 14-years of age from Corvallis, Albany, Sweet Home, Salem, Eugene, and the greater Portland area. Bone mineral content (BMC, g) and bone mineral density (BMD, g/cm²) of the proximal left hip, spine, and whole body were assessed by dual energy x-ray absorptiometry (Hologic QDR 4500A; Hologic Inc., Waltham, MA, USA). We used ANCOVA and report that baseline BMC and BMD values of girl soccer players at the greater trochanter were significantly higher compared to controls and the swim group, and femoral neck BMC was significantly greater than the swimmers. At baseline, all boy groups were similar at the hip and spine. After 12-months, ANCOVA was also used to assess absolute change for BMC and BMD at the hip and spine. The girl soccer players had significantly more BMC and BMD at the greater trochanter as well as total hip BMD and lumbar spine BMC compared to the swimmers, but not the controls. The girl control group showed a significantly greater 12-month change for femoral neck and greater trochanter BMC than swimmers. Overall, the girl swimmers demonstrated a lower accumulation of bone mass during the 12-month study period. As for the boys, soccer players had a significantly higher 12-month change for femoral neck BMC than swimmers, but were similar at the spine. There were no differences between the boy control subjects and the swimmers for 12-month change values at the hip and spine. While preliminary and limited by the small sample size, our results indicate that after controlling for growth, soccer players gained significantly more BMC at the femoral neck than swimmers. Furthermore, exposing the young skeleton to impact loading exercise has site-specific benefits at the hip whereas prolonged training in a non-weight bearing environment may compromise skeletal acquisition. / Graduation date: 2004

The aim of this study is to identify the preferred animal species at Byzantine city of Amorium and accordingly to find the spatial relationship between context and the purpose of animal use such as dietary habits, workshop activities, possible socioeconomic differentiation and subsistence economy as well as the ecology of Amorium environment. The animal bones were examined in order to determine their species. The identified animal bones were assessed by calculating the frequencies of the each species. Thus, which species were the most essential for the diet, and the basic aims of the animal economy, could be determined. In addition to domestic animals, the wild fauna was also studied to answer the question of which species were chosen for exploitation and whether or not wild sources were of considerable portion, gathered by fishing and hunting. For the spatial analysis, the species compositions as well as the skeletal representation tables of each assemblage of each different context were studied. The species composition appeared similar amongst most of the contexts but the skeletal representation tables gave more information on the use of species, especially allowing the separation of contexts containing domestic refuse and the contexts that had an overwhelming proportion of bones elements that could have been used for industrial activities (bone working).