Introduction Ethnic differences in bone growth and proportions have previously been investigated in relation to bone fragility. Differential growth in the axial and appendicular skeletons has been suggested to predispose to differential susceptibility to fracture. The developmental origins of bone size and osteoporosis have also been investigated. However, the impact of foetal programming on body proportions and limb lengths in unknown. Objectives The aim of this study was to investigate the presence of ethnic and sex differences in axial and appendicular growth. Additionally, it was to investigate the impact of early life factors on skeletal dimensions and proportions in childhood . Methods Anthropometric measurements of stature, weight, sitting height and limb lengths were taken on 368 black and white, male and female 9 year old children. DXA scans of the distal ulna;distal radius; hip and lumbar spine were also obtained. The same measurements were obtained for 197 of the black children who had birthweight and weight and length data at 1 year. For the first part of the analyses, Analyses of Covariance were performed to assess differences in limb lengths adjusted for differences in stature. Multiple regression analyses were used to assess significant predictors of site-specific bone mass. Comparisons were made after adjustment for weight, weight and stature and weight and regional segment lengths. For the second part of the analyses, Analyses of Covariance were performed to assess differences in stature and regional segment lengths at different tertiles of birthweight, and weight and height at 1 year. Stepwise multiple regressions were performed with early life growth patterns to assess significant predictors of stature and regional segment lengths at 10 years. Results Black children had longer limbs but shorter trunks than white children. Regional segment length were a more significant predictor of site-specific bone mass than stature. In black boys birthweight had positive but weak associations with stature and regional segment length while in girls the association were marginal. In contrast, weight and height at 1yr had strong associations with stature and regional segment lengths. Conclusion There is a differential effect of ethnicity and sex on the growth of the axial and appendicular skeletons, and regional segment length is a better predictor of site-specific bone mass than stature. Early life growth has a long-term influence on stature, as well as on regional segment lengths but marginal effect on body proportions.

Thesis (Ph.D.)--University of the Witwatersrand, Faculty of Health Sciences, 2012 / Osteoporosis has been described as a paediatric disease with geriatric consequences. This thesis explored the associations between proximal, historical and predictive genetic and environmental factors affecting bone mass and bone size in socio-economically- and environmentally-disadvantaged black and -advantaged white pre- and early-pubertal South African children. Data were collected from 476 children (182 black boys, 72 white boys, 158 black girls, 64 white girls) of mean age 10.6 years (range: 10.0-10.9), 406 biological mothers and 100 biological fathers. The main findings were that black children and their parents compared to white, had greater DXA-measured BMC at the femoral neck regardless of the way in which BMC was corrected for size (height, weight, BA and/or BAPC) and greater bone strength. Lumbar spine BMC was greater or similar depending on which measures were used to correct BMC for size. At the whole body, mid radius and distal one third of the radius, BMC varied between children, and between their parents, and were dependent on which measures were used to correct BMC for size. Weight at 1 year (WT1), length at 1 year (LT1) and birth weight (BW), were significant predictors of BMC of the femoral neck (P<0.05-0.01) after correcting BA and BMC for race/ethnicity, gender, age, socioeconomic status, bone age, height and weight at 10 years. Maternal and paternal heritability was estimated to each be ~30% in both black and white subjects. The main conclusion was that ethnicity is the single most important proximal factor affecting bone mass and bone size in 10 year old South African children. Black children demonstrate a superior bone mass and bone strength at the femoral neck. Historical and predictive factors however indicate that black children have not been programmed for optimal bone health in utero and early life, nor are contemporary environmental factors favourable for the maximisation of peak bone mass. This cohort may be at risk of developing osteoporosis as an elderly population, particularly at the lumbar spine and forearm.

Aims: 1) To determine the incidence or rates of fractures, the common sites of fractures, the causes of fractures and grades of trauma causing fractures in urban South African children of different ethnic groups from birth until 17/18 years of age. 2) To investigate the association between fracture prevalence, bone mass and physical activity in South African children. 3) To assess associations of fracture prevalence and bone mass in adolescents with maternal fracture history and bone mass and sibling fracture history. Design: Using the Birth to Twenty longitudinal cohort of children, we obtained retrospective information on fractures and their sites from birth to 14.9 years of age on 2031 participants. The ethnic breakdown of the children was black (B) 78%, white (W) 9%, mixed ancestry (MA) 10.5% and Indian (I) 1.5%. Using the Bone Health cohort of the Birth to Twenty longitudinal study, we retrospectively obtained information of lifetime fractures until age 14.9 years in 533 subjects. Bone mass (measured by DXA), anthropometric data, physical activity scores and skeletal maturity were obtained at age 10 and 15 years. Comparisons were made between those who did and did not fracture within the same sex and ethnic groups. The third component of the thesis utilized data from 1389 adolescent-biological mother pairs of the Birth to Twenty (Bt20) longitudinal study. Questionnaires were completed on adolescent fractures until 17/18 years of age and on sibling fractures. Biological mothers completed questionnaires on their own fractures prior to the age of 18 years. Anthropometric and bone mass data on adolescent-biological mother pairs were collected. Results: Twenty two percent of children had sustained a fracture one or more times during the first 15 years of life (males 27.5% and females 16.3%; p<0.001). The percentage of children fracturing differed between the ethnic groups (W 41.5%, B 19%, MA 21%, I 30%; p<0.001). Of the children reporting fractures, 20% sustained multiple fractures. The most common site of fracture was the upper limb (57%). In the second component of the thesis, white males who fractured were found to be significantly taller (10 years p < 0.05), more physically active (15 years p < 0.01) and had higher lean body mass (10 years p=0.001; 15 years p<0.05) than those who did not fracture; while white females, who fractured, were fatter (10 and 15 years p< 0.05), than their nonfracturing peers. White males who fractured had greater BA (bone area) and BMC (bone mineral content) at most sites at 10 and 15 years; BA and BMC were no different between fracturing and non-fracturing children in the other ethnic groups. No anthropometric or bone mass differences were found between black children with or without fractures. The third component of the thesis showed that an adolescent’s risk of lifetime fracture decreased with increasing maternal lumbar spine (LS) BMC (24% reduction in fracture risk for every unit increase in maternal LS BMC Z-score) and increased if they were white, male or had a sibling with a history of fracture. Adolescent height, weight, male gender, maternal BA and BMC, and white ethnicity were positive predictors of adolescent bone mass. White adolescents and their mothers had a higher fracture prevalence (adolescents: 42%, mothers: 31%) compared to the black (adolescents: 20%, mothers: 6%) and mixed ancestry (adolescents: 20%, mothers: 16%) groups. Conclusion: More than twice as many South African white children fracture compared to black and mixed ancestry children. This is the first study to show ethnic differences in fracture rates among children; a pattern that is similar to that found in South African postmenopausal women. The factor associated with fractures in white boys appears to be participation in sports activities, while in white girls obesity appears to play a role. We were unable to find any factors that could explain fractures in black children. Unlike the findings of some other studies, fractures in these children were not associated with lower bone mass or reduced skeletal size. Maternal bone mass also appears to play a role in determining fracture incidence in children, as the mother’s bone mass has a significant inverse association with their off-springs’ fracture risk throughout childhood and adolescence. Furthermore, there is a strong familial component in fracture risk among South African adolescents and their siblings, as evidenced by the increased risk of fracture in siblings of index children who have fractured during childhood and adolescence. Differences in fracture rates and bone mass between families and individuals of different ethnic origins may be due to differing lifestyles and/or genetic backgrounds.

Orientador: Luiz Antônio Salata / Banca: Osvaldo Magro Filho / Banca: Sérgio Luiz Scombatti Souza / Banca: Wilson Roberto Poi / Banca: Andreza Ribeiro Simioni / Resumo: A combinação de um fármaco fotossensível (FS) ativado por luz (vermelha, infravermelho ou ambas) forma uma das vertentes de aplicação da Terapia Fotodinâmica (TFD), que consiste na administração de um FS que posteriormente é ativado pela irradiação do LED ou Laser junto ao tecido, sendo que o FS ou a luz sozinhas, não apresentam citotoxicidade. O presente estudo teve por objetivos estabelecer o potencial regenerador do tecido ósseo para o reparo em calvária de coelho, utilizando três sistemas de liberação de drogas (DDS) de FS, estimulado pela combinação da fotobiomodulação de sistemas LED operando na faixa do visível e infravermelho. Foram utilizados 48 coelhos New Zealand White divididos em 3 grupos: Grupo LED 24/48 (dezoito coelhos) com aplicações de LED 24/48 horas após a cirurgia, Grupo LED 72/96 (dezoito coelhos) com aplicações de LED 72/96 horas após a cirurgia e Controle (doze coelhos) onde não houve aplicação de LED. Nos grupos experimentais foram realizadas 4 perfurações nas calvárias com preenchimento aleatoriamente de 1) Base em gel, 2) nanoemulsão carregada com FS, 3) lipossoma em gel com FS e 4) nanopartículas de albumina (BSA) carregada com FS. No grupo controle foram feitas duas perfurações, uma preenchida por osso autógeno e outra com coágulo. Dezesseis animais foram submetidos à eutanásia em cada tempo experimental: 5 dias, 10 dias e 20 dias. Lâminas histológicas foram feitas a partir dos defeitos e o osso neoformado foi mensurado. O uso de FS nos DDS não foi efetivo para abreviar o tempo de reparo ósseo em calvária de coelhos nos inervalos de tempo deste estudo / Abstract: The combination between photosensitizer substances with laser or LED (light emitting diode) form the photodynamic therapy (PDT) basis that consists of photosensitivity drug activated by low frequency light. This mechanism is used in soft tissue healing process to improve the oxygen tension leading to a fast revascularization. The objective of this study was to evaluate the effects of photosensitivity drugs activated through LED on bone healing process. Fourty eight New Zealand White rabbits were underwent to four bicortical calvaria defects made by 6.0 mm trephine drill. The defects were randomly filled up with (1) Gel, (2) Nanoemulsion + photosensitizer drug, (3) Liposome + photosensitizer drug, (4) NPS (nanostructure polymeric system) + photosensitizer drug. After 24/48 hours or 72/96 hours a LED were applied on all the rabbits. Sixteen animals were sacrificed, respectively, at 5, 10 and 20 days after surgery. Histological slides were prepared from each experimental site for histomorphometry and histological analysis. Bone graft was significant higher bone level in all experimental time points.. At 10 days liposome showed higher bone level than Gel (p=0,0161). However on 20 days, no difference was detected between the materials. The use of photosensitizer drugs activated by LED demonstrated do not achieve the stimulate bone formation on later time points on thsi presente study / Doutor

by Chong Wai Sing, Wilson. / Thesis submitted in: August 2002. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 116-126). / Abstracts in English and Chinese. / ACKNOWLEDGEMENT --- p.i / ABBREVIATION --- p.ii / ABSTRACT (Chinese & English) --- p.iii / TABLE OF CONTENT --- p.vii / INDEX FOR FIGURES --- p.x / INDEX FOR TABLES --- p.xiii / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- "Bone-tendon junction - types, structures and functions" --- p.2 / Chapter 1.1.1 --- Indirect insertion --- p.3 / Chapter 1.1.2 --- Direct insertion --- p.3 / Chapter 1.1.3 --- Functional adaptations of insertions --- p.4 / Chapter 1.2 --- Incidence and type of injuries near insertion site --- p.5 / Chapter 1.3 --- Treatment protocol for injuries near insertion site --- p.5 / Chapter 1.3.1 --- Non-operative versus operative approach --- p.5 / Chapter 1.3.2 --- Previous studies on validations of outcomes of difference repair methods --- p.6 / Chapter 1.4 --- Modes of healing underlying different repair approach --- p.7 / Chapter 1.4.1 --- Fracture healing --- p.7 / Chapter 1.4.2 --- Tendon healing --- p.8 / Chapter 1.4.3 --- Bone-tendon healing --- p.9 / Chapter 1.5 --- Objectives --- p.9 / Chapter 2. --- Materials and Methods --- p.12 / Chapter 2.1 --- Animal model --- p.13 / Chapter 2.2 --- Experimental design --- p.13 / Chapter 2.3 --- Surgery --- p.13 / Chapter 2.3.1 --- Bone-to-bone repair --- p.14 / Chapter 2.3.2 --- Bone-to-tendon repair --- p.14 / Chapter 2.3.3 --- Tendon-to-tendon repair --- p.15 / Chapter 2.4 --- Post-operative follow-up --- p.15 / Chapter 2.4.1 --- Radiographic examination --- p.15 / Chapter 2.4.2 --- Polychrome sequential labeling --- p.16 / Chapter 2.4.2.1 --- Reagents --- p.16 / Chapter 2.4.2.2 --- Route of administration --- p.16 / Chapter 2.5 --- Sampling --- p.17 / Chapter 2.6 --- Histology --- p.17 / Chapter 2.6.1 --- Decalcification --- p.17 / Chapter 2.6.1.1 --- Tissue decalcification --- p.17 / Chapter 2.6.1.2 --- Tissue processing --- p.17 / Chapter 2.6.1.3 --- Immunohistochemistry of collagen type II and III --- p.18 / Chapter 2.6.1.3.1 --- Reagents and solution preparation --- p.18 / Chapter 2.6.1.3.2 --- Experimental procedures --- p.20 / Chapter 2.6.2 --- Undecalcification --- p.22 / Chapter 2.6.2.1 --- Specimen preparations --- p.22 / Chapter 2.6.2.2 --- Toluidine blue staining --- p.22 / Chapter 2.7 --- Mechanical test --- p.23 / Chapter 2.7.1 --- Sample preparation --- p.23 / Chapter 2.7.2 --- Embedding procedures --- p.23 / Chapter 2.7.3 --- Measurement of cross-sectional area of healing interface --- p.23 / Chapter 2.7.3.1 --- CSA for BB --- p.23 / Chapter 2.7.3.2 --- CSA for BT and TT --- p.24 / Chapter 2.7.4 --- Tensile test --- p.24 / Chapter 2.7.4.1 --- Testing procedures --- p.24 / Chapter 2.7.4.2 --- Interpretation of testing results --- p.25 / Chapter 2.7.5 --- Statistical analysis --- p.26 / Chapter 3. --- Results --- p.42 / Chapter 3.1 --- Surgical outcome --- p.43 / Chapter 3.1.1 --- Radiographic examination --- p.43 / Chapter 3.1.1.1 --- Bone-to-bone healing --- p.43 / Chapter 3.1.1.2 --- Bone-to-tendon healing --- p.44 / Chapter 3.1.2 --- Fluorochrome injection --- p.44 / Chapter 3.2 --- Histology --- p.45 / Chapter 3.2.1 --- Bone-to-bone healing --- p.45 / Chapter 3.2.1.1 --- Gross anatomy --- p.45 / Chapter 3.2.1.2 --- Microscopic examination --- p.45 / Chapter 3.2.1.3 --- Polarised light microscopy --- p.46 / Chapter 3.2.1.4 --- Fluorochrome microscopy --- p.46 / Chapter 3.2.2 --- Bone-to-tendon healing --- p.47 / Chapter 3.2.2.1 --- Gross anatomy --- p.47 / Chapter 3.2.2.2 --- Microscopic examination --- p.47 / Chapter 3.2.2.3 --- Polarised light microscopy --- p.48 / Chapter 3.2.2.4 --- Fluorochrome microscopy --- p.49 / Chapter 3.2.3 --- Tendon-to-tendon healing --- p.49 / Chapter 3.2.3.1 --- Gross anatomy --- p.49 / Chapter 3.2.3.2 --- Microscopic examination --- p.49 / Chapter 3.2.3.3 --- Polarised light microscopy --- p.50 / Chapter 3.3 --- Mechanical testing --- p.50 / Chapter 3.3.1 --- Bone-to-bone healing --- p.50 / Chapter 3.3.1.1 --- Change of cross sectional area --- p.50 / Chapter 3.3.1.2 --- Load at failure --- p.50 / Chapter 3.3.1.3 --- Strength --- p.51 / Chapter 3.3.1.4 --- Energy --- p.51 / Chapter 3.3.2 --- Bone-to-tendon healing --- p.51 / Chapter 3.3.2.1 --- Change of cross sectional area --- p.51 / Chapter 3.3.2.2 --- Load at failure --- p.52 / Chapter 3.3.2.3 --- Strength --- p.52 / Chapter 3.3.2.4 --- Energy --- p.52 / Chapter 3.3.3 --- Tendon-to-tendon healing --- p.52 / Chapter 3.3.3.1 --- Change of cross sectional area --- p.53 / Chapter 3.3.3.2 --- Load at failure --- p.53 / Chapter 3.3.3.3 --- Strength --- p.53 / Chapter 3.3.3.4 --- Energy --- p.53 / Chapter 3.3.4 --- "Comparison of healing quality among BB, BT, and TT repair" --- p.54 / Chapter 3.3.4.1 --- Change of cross sectional area --- p.54 / Chapter 3.3.4.2 --- Load at failure --- p.54 / Chapter 3.3.4.3 --- Strength --- p.54 / Chapter 3.3.4.4 --- Failure mode --- p.55 / Chapter 4. --- Discussion --- p.102 / Chapter 4.1 --- Use of goat calcaneus-Achilles junction as a bone-tendon reseach model --- p.103 / Chapter 4.2 --- "Bone-to-bone, bone-to-tendon, and tendon-to-tendon fixation" --- p.104 / Chapter 4.3 --- Histological characterization of different healing tissues --- p.105 / Chapter 4.3.1 --- Bone-to-bone healing (Fracture healing) --- p.105 / Chapter 4.3.2 --- Bone-to-tendon healing --- p.106 / Chapter 4.3.3 --- Tendon-to-tendon healing --- p.106 / Chapter 4.3.4 --- Regeneration versus repair --- p.107 / Chapter 4.4 --- Spatial and temporal expression of different type of collagen in different form of healing --- p.108 / Chapter 4.5 --- Mechanical properties of healing interface under different form of fixation --- p.108 / Chapter 4.5.1 --- Failure mode --- p.110 / Chapter 4.6 --- Limitations --- p.111 / Chapter 4.6.1 --- Goat animal model --- p.111 / Chapter 4.6.2 --- Immunohistochemistry --- p.111 / Chapter 4.7 --- Future study --- p.112 / Chapter 5. --- Conclusion --- p.113 / Chapter 6. --- References --- p.116

Made available in DSpace on 2014-06-11T19:31:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-28Bitstream added on 2014-06-13T19:20:06Z : No. of bitstreams: 1 faria_pep_dr_araca.pdf: 1244848 bytes, checksum: 1c3d78205883be40533349acdfc5ffde (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A combinação de um fármaco fotossensível (FS) ativado por luz (vermelha, infravermelho ou ambas) forma uma das vertentes de aplicação da Terapia Fotodinâmica (TFD), que consiste na administração de um FS que posteriormente é ativado pela irradiação do LED ou Laser junto ao tecido, sendo que o FS ou a luz sozinhas, não apresentam citotoxicidade. O presente estudo teve por objetivos estabelecer o potencial regenerador do tecido ósseo para o reparo em calvária de coelho, utilizando três sistemas de liberação de drogas (DDS) de FS, estimulado pela combinação da fotobiomodulação de sistemas LED operando na faixa do visível e infravermelho. Foram utilizados 48 coelhos New Zealand White divididos em 3 grupos: Grupo LED 24/48 (dezoito coelhos) com aplicações de LED 24/48 horas após a cirurgia, Grupo LED 72/96 (dezoito coelhos) com aplicações de LED 72/96 horas após a cirurgia e Controle (doze coelhos) onde não houve aplicação de LED. Nos grupos experimentais foram realizadas 4 perfurações nas calvárias com preenchimento aleatoriamente de 1) Base em gel, 2) nanoemulsão carregada com FS, 3) lipossoma em gel com FS e 4) nanopartículas de albumina (BSA) carregada com FS. No grupo controle foram feitas duas perfurações, uma preenchida por osso autógeno e outra com coágulo. Dezesseis animais foram submetidos à eutanásia em cada tempo experimental: 5 dias, 10 dias e 20 dias. Lâminas histológicas foram feitas a partir dos defeitos e o osso neoformado foi mensurado. O uso de FS nos DDS não foi efetivo para abreviar o tempo de reparo ósseo em calvária de coelhos nos inervalos de tempo deste estudo / The combination between photosensitizer substances with laser or LED (light emitting diode) form the photodynamic therapy (PDT) basis that consists of photosensitivity drug activated by low frequency light. This mechanism is used in soft tissue healing process to improve the oxygen tension leading to a fast revascularization. The objective of this study was to evaluate the effects of photosensitivity drugs activated through LED on bone healing process. Fourty eight New Zealand White rabbits were underwent to four bicortical calvaria defects made by 6.0 mm trephine drill. The defects were randomly filled up with (1) Gel, (2) Nanoemulsion + photosensitizer drug, (3) Liposome + photosensitizer drug, (4) NPS (nanostructure polymeric system) + photosensitizer drug. After 24/48 hours or 72/96 hours a LED were applied on all the rabbits. Sixteen animals were sacrificed, respectively, at 5, 10 and 20 days after surgery. Histological slides were prepared from each experimental site for histomorphometry and histological analysis. Bone graft was significant higher bone level in all experimental time points.. At 10 days liposome showed higher bone level than Gel (p=0,0161). However on 20 days, no difference was detected between the materials. The use of photosensitizer drugs activated by LED demonstrated do not achieve the stimulate bone formation on later time points on thsi presente study

Thesis (doctoral)--University of Göteborg, 1984. / Extra t.p. with thesis statement inserted. Includes bibliographical references.

Thesis (Ph. D.)--School of Dentistry. University of Missouri--Kansas City, 2006. / "A dissertation in oral biology and cell biology and biophysics." Advisor: Lynda F. Bonewald. Typescript. Vita. Title from "catalog record" of the print edition Description based on contents viewed Nov. 12, 2007. Includes bibliographical references (leaves 121-139). Online version of the print edition.

Diss. (sammanfattning) Umeå : Univ., 2003. / Härtill 5 uppsatser.

Dissertation (Ph.D.).--University of Texas Graduate School of Biomedical Sciences at San Antonio, 2007. / Vita. Includes bibliographical references.