Um dos principais fatores que influencia os resultados da terapia de implantes dentários é a densidade do osso alveolar. A sua avaliação permitiria a predição do torque de inserção do implante levando a um planejamento preciso do tratamento. O presente estudo de coorte teve como objetivo definir e correlacionar características radiográficas e morfológicas do osso, e sua influencia no torque de inserção. Foram analisados dados demográficos, radiografias panorâmicas e tomografias computadorizadas por feixe cônico (TCFC) de um total de 25 pacientes que receberam 31 implantes. Amostras ósseas retiradas dos sítios implantares foram avaliadas com densitometria óssea, micro-tomografia computadorizada, e histomorfometria. A análise de escala de cinzas avaliada com a TCFC foi fortemente correlacionada com a microtomografia computadorizada (r=0,504, p=0,004) e com a histomorfometria (r=0,795, p=0,001). No entanto, os resultados da correlação de Spearman mostraram que o torque máximo de inserção foi fortemente correlacionado com a espessura cortical do rebordo (r=0,609, p=0,001). Os resultados indicam que o torque de inserção é influenciado principalmente pela camada cortical do osso alveolar. O trabalho propõe ainda uma classificação clínica de predição de torque, baseada em resultados de sensitividade e especificidade da combinação de variáveis diferentes. A TCFC de 14-bit foi indicada como confiável para avaliar a densidade do tecido ósseo alveolar através da escala de cinzas. / A main factor influencing dental implant therapy outcomes is the alveolar bone density. Its assessment would allow for prediction of implant insertion torque (IT), leading to a precise treatment planning. The present cohort study aimed to define and correlate imaging and morphometric bone features influencing IT. Demographics, panoramic radiographs and cone beam computed tomographic (CBCT) scans of a total of 25 patients receiving 31 implants were analyzed. Bone samples retrieved from implant sites were assessed with dual x-ray absorptiometry, micro-computed tomography, and histomorphometry. Grayscale analysis using CBCT was strongly correlated with micro-computed tomography and with histomorphometric analysis (r=0.795, p=0.001). However, Spearmans correlation results showed that peak IT was strongly correlated with ridge cortical thickness (r=.609, p=.001). These results indicate that IT is mainly influenced by the amount of alveolar cortical bone layer. This work further propose a clinical classification for IT prediction, based on findings of sensitivity and specificity of the combination of different variables. 14-bit CBCT was indicated as reliable to assess alveolar bone density using grayscale analysis.

Submitted by JÚLIO HEBER SILVA (julioheber@yahoo.com.br) on 2016-11-28T16:26:19Z No. of bitstreams: 2 Tese - Camila Kellen de Souza Cardoso - 2016.pdf: 3418310 bytes, checksum: cdf808292a924eda861aac5082af3dde (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2016-11-28T17:23:33Z (GMT) No. of bitstreams: 2 Tese - Camila Kellen de Souza Cardoso - 2016.pdf: 3418310 bytes, checksum: cdf808292a924eda861aac5082af3dde (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-11-28T17:23:33Z (GMT). No. of bitstreams: 2 Tese - Camila Kellen de Souza Cardoso - 2016.pdf: 3418310 bytes, checksum: cdf808292a924eda861aac5082af3dde (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-11-11 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / Aim: To assess the associated factors to bone mineral density (BMD), as well as the effects of extra virgin olive oil and the Brazilian Traditional Diet (DietBra) on bone health of severely obese patients. Methods: The first study refers to baseline data of a randomized clinical trial (RCT) that analyzes sociodemographic factors, lifestyle, health conditions, anthropometric and biochemical data associated with BMD of total body, total vertebral column, and total hip. The second study is a blind RCT with three groups of intervention: olive oil, receiving 52 ml/day of extra virgin olive oil and habitual dietary intake; diet, receiving a DietBra; and olive oil + DietBra, receiving 52 ml/day of olive oil and healthy diet prescription. The three groups had monthly consults with a nutritionist and were followed-up during 12 weeks. BMD of total vertebral column was primary outcome of the RCT, while BMD of otal hip, calcium, vitamin D, and parathormone (PTH) were secondary outcomes. Data collection occurred between June 2015 and February 2016 with 111 severely obese patients (Body Mass Index ≥ 35 kg/m2 ). The allocation ratio between groups in the RCT was 1:1:1. BMD was evaluated by Dualenergy x-ray absorptiometry. Kolmogorov-Smirnov test was employed to verify normal distribution of continuous data. Student’s t-test, ANOVA, Bonferroni, simple linear regression, and hierarchic multiple linear regression were used to analyze baseline data. Fisher’s exact test, Pearson’s chi-square test, unpaired Student’s t-test, ANOVA, Bonferroni, and ANCOVA were used to analyze the data from the clinical trial by intention to treat. The significance level was set at p<0.05. Results: At the first level of baseline, men presented higher BMD of total body than women (p≤0.001), while advanced age was associated with lower BMD in the three measurement sites (p=0.047, 0.039 and 0.010). At the second level, having diabetes mellitus type 2 (DM2) was associated with higher BMD of total body (p=0.033), while ≥150 min/week of aerobic physical activity was associated with higher BMD of vertebral column (p=0.028) and total hip (p=0.004). Patients presenting previous fracture (p=0.013) and with a higher degree of obesity (p=0.015) had lower BMD of total vertebral column. Having an adequate intake of vitamin D was associated with higher BMD of total vertebral column (p=0.020). At the third level, low serum zinc (p=0.024) and elevated C-reactive protein (p=0.049) were associated with lower BMD of total vertebral column. In the RCT, the olive oil group presented an increase in serum calcium between baseline and the end of follow-up (p=0.007). Mean serum calcium was higher in the olive oil group compared to the olive oil + DietBra group at the end of follow-up (p=0.026). The DietBra group presented a higher means BMD of total vertebral column (p=0.016) and BMD of total hip (p=0,029) than the olive oil + DietBra group. In addiction, the PTH reduced in DietBra group after intervention (p=0.047) and delta PTH was higher in the DietBra group compared to the olive oil + DietBra group (p=0.042). Conclusion: Classic factors associated with bone health as gender, advanced age, physical activity, previous fracture, vitamin D intake and C-reactive protein also occurred in severely obese individuals, although tobacco use, solar exposure, medication use, serum calcium and vitamin D were not associated with BMD. Furthermore, the DietBra increased BMD of total vertebral column and reduced PTH, while the extra virgin olive oil was increased serum calcium. In a separate way, both interventions had good results for severely obese patients' bone health. / Objetivo: Avaliar os fatores associados a densidade mineral óssea (DMO), assim como os efeitos do azeite de oliva extravirgem e dieta tradicional brasileira (DietBra) na saúde óssea de obesos graves. Metodologia: o primeiro estudo trata-se de dados do baseline do ensaio clínico randomizado (ECR), com análise de fatores sociodemográficos, estilo de vida, condições de saúde, dados antropométricos e bioquímicos associados à DMO de corpo total, coluna total e quadril total. O segundo estudo é um ECR cego, com três grupos de intervenção: grupo azeite que recebeu 52 mL/dia (4 sachês) de azeite de oliva extravirgem e manteve a alimentação habitual, o grupo DietBra que recebeu prescrição de dieta saudável com padrão de dieta tradicional brasileira e o grupo azeite + DietBra que recebeu 52 mL/dia (4 sachês) e prescrição de dieta saudável com padrão de dieta tradicional brasileira. Os três grupos tiveram consultas mensais, em dias diferentes da semana, com seguimento de 12 semanas, foram avaliadas a DMO de coluna total como desfecho primário e DMO de quadril total, cálcio, vitamina D e paratormônio (PTH) como desfechos secundários do ECR. A coleta de dados ocorreu entre junho de 2015 e fevereiro 2016, com 111 pacientes obesos graves (índice de massa corporal ≥35 kg/m2 ), com proporção entre os grupos do ECR em torno de 1:1:1. A DMO foi avaliada pelo método de Dual-energy X-ray absorptiometry (DXA). Foi empregado o teste Kolmogorov-Smirnov para verificar a normalidade dos dados. Para os dados do baseline foi utilizado T de Student ou Anova, seguindo de Bonferroni, Regressão Linear Simples e Regressão Linear Múltipla modelo hierarquizado. Para o ECR foi utilizado Teste Exato de Fisher ou QuiQuadrado de Person, T de Student, ANOVA seguida de Bonferroni e ANCOVA, foi adotada a abordagem estatística por intenção de tratar por meio da aplicação do teste T Student não-pareado intra grupo. Foi considerado p<0,05. Resultados: no primeiro nível do baseline, homens apresentaram maior DMO de corpo total (p= <0,001) do que mulheres, enquanto a idade avançada foi associada a menor DMO nos três sítios (p=0,047, 0,039 e 0,010). No segundo nível, ter diabetes mellitus tipo 2 (DM2) foi associado a maior DMO de corpo total (p=0,033), enquanto ≥150 minutos/semana de atividade física aeróbica foi associada com maior DMO de coluna total (p=0,028) e quadril total (p=0,004), assim como indivíduos com fratura prévia (p=0,013) e maior grau de obesidade (p=0,015) apresentaram menor DMO de coluna total. Por outro lado, ter ingestão adequada de vitamina D esteve associado a maior DMO de coluna total (p=0,020). No terceiro nível, o zinco sérico baixo (p=0,024) e PCR elevada (p=0,049) associaram-se a menor DMO de coluna total. No ECR, o grupo azeite apresentou aumento no cálcio sérico entre o início e final do estudo (p=0,007), assim como a média final de cálcio foi maior no grupo azeite em comparação ao grupo azeite + DietBra (p=0,026), o grupo DietBra apresentou média final de DMO de coluna total (p=0,016) e DMO de quadril (p=0,029) maior do que o grupo azeite + DietBra, além disso o PTH reduziu no grupo DietBra pós a intervenção (p=0,047) e o delta PTH foi maior no grupo DietBra em comparação ao grupo azeite + DietBra (p=0,042). Conclusão: fatores clássicos associados à saúde óssea como sexo, idade mais avançada, atividade física, fratura prévia, ingestão de vitamina D e proteína C-reativa também ocorreram em obesos graves, mas tabagismo, exposição solar, uso de medicamentos, cálcio e vitamina D séricos não foram associados à DMO em obesos graves. Além disso, a DietBra aumentou DMO de coluna total e reduziu PTH, enquanto o azeite de oliva extravirgem aumentou cálcio sérico. Ou seja, de forma isolada as intervenções tiveram bons resultados para saúde óssea de obesos graves

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-02-26T18:21:33Z No. of bitstreams: 1 barbarabrunaabreudecastro.pdf: 2415695 bytes, checksum: 47789bf55f4ba51557e83055236dab2f (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-03-03T14:09:35Z (GMT) No. of bitstreams: 1 barbarabrunaabreudecastro.pdf: 2415695 bytes, checksum: 47789bf55f4ba51557e83055236dab2f (MD5) / Made available in DSpace on 2016-03-03T14:09:35Z (GMT). No. of bitstreams: 1 barbarabrunaabreudecastro.pdf: 2415695 bytes, checksum: 47789bf55f4ba51557e83055236dab2f (MD5) Previous issue date: 2015-08-13 / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / Introdução: A Doença Renal Crônica (DRC) provoca alterações nas concentrações de fósforo, cálcio, vitamina D e paratormônio. A Quitosana Fe(III) reticulada (QSTFe( III)R) é um quelante de fósforo capaz de reduzir a hiperfosfatemia, principal indutora da calcificação vascular (CV) na DRC. Este polímero derivado da quitina mostrou ação quelante sobre o fósforo in vitro e in vivo em animais não urêmicos. Objetivo: Avaliar a ação quelante de fósforo da QST-Fe(III)R e seu efeito sobre a calcificação vascular em ratos com uremia induzida por adenina. Métodos: Ratos normais e urêmicos induzidos por dieta rica em fósforo (1%) e suplementada com adenina (0,75% - 4 semanas e 0,10% - 3 semanas) foram divididos em 4 grupos e tratados diariamente com água destilada (10ml/Kg/dia); 30mg/Kg/dia de QTSFe( III)R; 500mg/Kg/dia de CaCO3 e 500mg/Kg/dia de Cloridrato de sevelamer (Cl- Sev) durante 4 semanas. Foram mensurados creatinina (Cr), fósforo (P) e cálcio sérico (Ca), fosfatase alcalina (FA), PTH e FGF23, ao final da 4ª e 7ª semanas de experimento. O conteúdo de Ca foi quantificado em fragmentos da aorta abdominal e expresso em mg/g de aorta. Alterações da morfologia vascular foram avaliadas de forma semi-quantitativa no arco da aorta pela coloração de von Kossa. Utilizamos anticorpos específicos para identificação da expressão da angiotensina II (AngioII) e alfa-actina do músculo liso (α-actina) pela técnica de imuno-histoquímica, em fragmentos do arco da aorta. A avaliação morfológica foi realizada apenas na 7ª semana. Resultados: Nos grupos urêmicos observamos redução da função renal com pico de creatinina na quarta semana. Os tratamentos não alteraram a progressão da doença. O grupo DRC apresentou nível de fósforo 35% mais elevado comparado ao grupo controle. Todos os tratamentos reduziram aproximadamente 20% do fósforo sérico, além de reduzirem a fração excretada de fósforo (redução de 20% a 30%). Os tratamentos com QTS-Fe(III)R e CaCO3 foram eficientes em reduzir o PTH e a FA dos animais urêmicos. Acredita-se que o tratamento com Cl-Sev não tenha sido eficiente devido à intercorrências metodológicas de dificuldade de administração da droga. O grupo DRC apresentou conteúdo de cálcio na aorta 80% maior do que o grupo controle e a QTS-Fe(III)R reduziu o conteúdo de cálcio na aorta, apresentando uma média mais baixa que todos os outros tratamentos. Em comparação com o grupo controle, a QTS-Fe(III)R reduziu a expressão de AngioII na camada íntima da aorta. A utilização dos tratamentos não apresentou benefícios sobre a integridade da camada média quando avaliamos a expressão de α-actina. Conclusões: O modelo experimental promoveu perda importante e sustentada de função renal. A QTS-Fe(III)r apresentou eficiência quelante semelhante aos demais já utilizados na prática clínica e reduziu o conteúdo de cálcio na aorta. / Introduction: Chronic Kidney Disease (CKD) causes changes in the concentrations of phosphorus, calcium, vitamin D and parathyroid hormone. Cross-linked Iron(III) Chitosan (QST-Fe(III)R) is a phosphorus binder, with properties of reducing the hyperphosphatemia, the main inducer of vascular calcification (VC) in CKD. This polymer derived from chitin showed chelating action on phosphorus in vitro and in vivo. Objective: To evaluate the phosphorus chelating action of QST-Fe(III)R and its effect on VC in adenine-induced uremic rats. Methods: Normal and uremic rats, induced by adenine feeding (0.75% - 4 weeks and 0.10% - 3 weeks) and phosphorous 1%, were divided into 4 groups and treated daily with distilled water (10ml/kg/day); QST-Fe(III)R 30mg/kg/day; CaCO3 500mg/kg/day and sevelamer hydrochloride (Cl-Sev) 500mg/kg/day, for 4 weeks. Biochemical parameters were measured at the fourth and seventh week: creatinine (Cr), phosphorus (P) and serum calcium (Ca), alkaline phosphatase (FA), PTH and FGF23. The Ca content of the abdominal aortic fragments was quantified and expressed as mg/g of aortic tissue. We evaluated vascular changes in the aortic arch and calcium deposition. Specific antibodies used to identify the expression of angiotensin II (AngioII) and alphasmooth muscle actin (α-actin) by immunohistochemical technique, in fragments of abdominal aorta at seventh week. Results: In uremic groups, we observed reduced kidney function and a maximum creatinine in the fourth week. The treatments did not alter CKD progression. The CKD group showed 35% higher phosphorus, compared to the control group. All treatments reduced approximately in 20% the serum phosphorus, and reduced the FeP (reduction of 20% to 30%). Treatments with QTSFe( III)R and CaCO3 were effective in reducing PTH and FA of uremic rats. We believe that treatment with Cl-Sev has not been effective due to methodological problems during drug administration. The CKD group presented aortic calcium content 80% higher than the control group and the QTS-Fe(III)R reduced the calcium content in the aorta, more than all other treatments. Compared to the control group, the QTS-Fe(III)R promotes the reduction expression of AngioII in aortic intima. The treatments did not show benefits over the media layer integrity when evaluating the α-actin expression. Conclusions: The experimental model showed important and sustained loss of renal function. The QTS-Fe(III)R showed efficiency similar to others phosporus binders already used in clinical practice and reduced the calcium content in the aorta.

Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-05-19T15:53:35Z No. of bitstreams: 1 vivianeangelinadesouza.pdf: 3640285 bytes, checksum: 152523820a34f8ec9830975c379401af (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-19T15:56:45Z (GMT) No. of bitstreams: 1 vivianeangelinadesouza.pdf: 3640285 bytes, checksum: 152523820a34f8ec9830975c379401af (MD5) / Made available in DSpace on 2017-05-19T15:56:45Z (GMT). No. of bitstreams: 1 vivianeangelinadesouza.pdf: 3640285 bytes, checksum: 152523820a34f8ec9830975c379401af (MD5) Previous issue date: 2012-03-08 / Atualmente, é descrito papel imunomodulador da vitamina D, além de seu já reconhecido efeito na manutenção da homeostase óssea. A insuficiência de vitamina D é considerada epidêmica, e pode influenciar a patogenia de doenças autoimunes, como o Lúpus Eritematoso Sistêmico (LES). Este estudo avaliou a prevalência de insuficiência de vitamina D em pacientes com LES comparados a controles saudáveis, além de associações entre vitamina D e manifestações clínicas, nefrite lúpica, atividade da doença e densidade mineral óssea (DMO). A vitamina D foi avaliada pela análise sérica da 25-hidroxivitamina D [25(OH)D] por cromatografia líquida de alta performance (HPLC) e níveis inferiores a 30 ng/mL foram considerados insuficientes. Foram avaliados 45 pacientes com LES e 25 controles saudáveis. A mediana (mínimo-máximo) da 25(OH)D foi 29,48 (20,83-44,23) ng/mL no grupo doente e 37,68 (22,91-44,07) ng/mL nos controles (p<0,0001). Ocorreu prevalência de insuficiência de 25(OH)D em 55% dos pacientes e 8% dos controles (p=0,001). A vitamina D associou-se com tempo de duração da doença (r=0,311; p=0,037) e uso de hidroxicloroquina (r=-0,337; p=0,024). Houve fraca evidência de associação inversa entre vitamina D e interleucina (IL)-6 (r=-0,276; p=0,066). Não houve associação entre 25(OH)D e nefrite lúpica ou densidade mineral óssea. O modelo de regressão logística multivariada evidenciou maior chance de ocorrer 25(OH)D < 30 ng/mL no grupo de pacientes lúpicos que nos controles (OR: 78,25;p=0,0001), quando ajustado para possíveis variáveis confundidoras. Nos pacientes lúpicos, a hipovitaminose D mostrou-se prevalente. A vitamina D associou-se com tempo de duração da doença e uso de hidroxicloroquina. / Currently, it is described an immunomodulator role of vitamin D besides its already known effect on bone homeostasis. Vitamin D insufficiency is considered to be epidemic and may influence the pathogenesis of autoimmune diseases, like Systemic Lupus Erythematosus (SLE). This study evaluated the prevalence of vitamin D insufficiency in patients with SLE compared to healthy controls, and the association between vitamin D and clinical parameters, lupus nephritis, disease activity and bone mineral density (BMD). Vitamin D was evaluated by serum analysis of 25-hydroxyvitamin D [25(OH)D] by high performance liquid chromatography (HPLC) and levels below 30 ng/mL were considered insufficient. We evaluated 45 patients with SLE and 25 healthy controls. Median (range) of 25(OH)D was 29,48 (20,83-44,23) ng/mL in lupus patients and 37,68 (22,91-44,07) ng/mL in controls (p<0,0001). The prevalence of 25(OH)D insufficiency was 55% in patients and 8% in controls (p=0,001). Vitamin D was associated with time of disease duration (r=0,311; p=0,037) and use of hydroxychloroquine (HXQ) (r=-0,337; p=0,024). There was a weak evidence of inverse association between vitamin D and interleukin (IL)-6 in patients with SLE (r=-0,276; p=0,066). No association between 25(OH)D and lupus nephritis or bone mineral density was found. Multivariate logistic regression analysis evidenced higher probability of 25(OH)D < 30 ng/mL in SLE patients than in controls (OR: 78,25; p=0,0001), when adjusted to possibly confounding variables. In lupus patients, hypovitaminosis D was prevalent. Vitamin D was associated with time of disease duration and use of hydroxychloroquine.

Les données biomécaniques sur les enfants sont rares et difficiles à obtenir lors d'expérimentations. Cette recherche s'intéresse à l'évaluation in vivo du comportement mécanique du tronc et des propriétés mécaniques de l'os cortical des côtes. Le comportement mécanique in vivo du tronc de l'enfant et de l'adulte sous charge pendant des manipulations de kinésithérapie respiratoire ont été étudiées. Trois formes typiques de courbes de force en fonction du déplacement ont été observées. Un plus grand décalage en temps entre les courbes de force en fonction du temps et les courbes de déplacement en fonction du temps ont été observés plus fréquemment chez les enfants que chez les adultes, ce qui conduit à différentes formes de courbes de force en fonction du déplacement entre les enfants et les adultes. Parmi les paramètres qui peuvent affecter le comportement mécanique du tronc, les propriétés mécaniques de l'os cortical des côtes ont été étudiées. Dans un premier temps, il a été constaté ex vivo que les propriétés mécaniques de l'os cortical des côtes des adultes sont liées de façon linéaire à la Densité Minérale Osseuse (DMO) mesurée par la tomodensitométrie quantitative (Quantitative Computed Tomography, QCT) et la tomographie périphérique quantitative à haute résolution (High Resolution Peripheral Quantitative Computed Tomography, HR-pQCT). La DMO peut être mesurée par QCT in vivo. Ensuite, les relations entre la DMO et les propriétés mécaniques pour l'adulte ont été appliquées aux enfants, et les propriétés mécaniques de l'os cortical de l'enfant ont pu être estimées. Les propriétés mécaniques ont été trouvées plus élevées dans la partie latérale des côtes que dans les régions antérieures et postérieures. Il a également été constaté que les propriétés mécaniques augmentent au cours de la croissance. Il s'agite la première étude qui a évalué les propriétés des matériaux de l'os cortical des côtes de l'enfant in vivo. Cette étude peut aider à mieux comprendre la réponse mécanique du tronc de l'enfant et les propriétés mécaniques de l'os cortical costal. À court terme, ces résultats mesurés in vivo seront considérés dans des modèles éléments finis du tronc de l'enfant / Biomechanical data on children, both mechanical behaviors and tissue properties, are rare and difficult to be obtained through biomechanical experiments. This thesis mainly discussed the mechanical behavior of pediatric trunk and mechanical properties of pediatric rib cortical bones in vivo. The mechanical responses of the living and active pediatric and adult trunks during in vivo loading tests were investigated. Three typical shapes of force-displacement curves were observed. Larger time lags between force time histories and displacement time histories were observed more frequently in children than adults, resulting in different shapes of force-displacement curves between children and adults. To better understand the mechanical behavior of pediatric trunk, rib cortical bone mechanical properties were studied. It was found that mechanical properties of adult rib cortical bones were linearly related to Bone Mineral Density (BMD) measured by Quantitative Computed Tomography (QCT) and High Resolution Peripheral Quantitative Computed Tomography (HR-pQCT). The BMD could be measured by QCT in vivo. Then, the mechanical property-BMD relationships were introduced to child population, and the mechanical properties of pediatric rib cortical bones were estimated. The mechanical properties were found higher in the lateral part of the ribs than the anterior and posterior regions. It was also found that the mechanical properties were growing during the growth of children. This is the first study which estimated the material properties of pediatric rib cortical bones in vivo. This study can help to better understand the mechanical response of pediatric trunk and mechanical properties of pediatric rib cortical bones. These results measured in vivo could contribute to improve the biofidelity of pediatric modeling

Abstract Today, the diagnosis of osteoporosis and assessment of fracture risk is based on estimation of bone mineral density (BMD) determined by dual-energy X-ray absorptiometry (DXA). A lack has been shown in the prediction of individual fracture risk using DXA-based BMD (BMDDXA). Digital radiography (DR) has eased the application of dual-energy techniques for separating bone and soft tissue, but the direct application of dual-energy digital radiography (DEDR) to determine BMD has not been investigated. Additionally, with BMD and bone mass, bone geometry affects strongly the mechanical strength of bone. Geometrical parameters can also be determined from the DR images. This study aimed to investigate the ability of DEDR to determine BMD and whether the combination of DEDR-based BMD and geometry improves the prediction of maximal load. Fracture and osteoporosis diagnoses could thus be done with one examination, i.e. with DEDR, whereas in the current routine both DR imaging and DXA examination are needed for diagnoses. Reindeer femora were imaged by DR with two different energies (79 and 100 kVp). The different geometrical parameters were also determined from the 79 kVp images. The BMD measured by DEDR (BMDDEDR) were calculated using the calculation principle of DXA. The ability of BMDDEDR to predict BMDDXA was investigated. The femora were mechanically tested in an axial loading configuration with the shaft in a vertical position to determine mechanical parameters. The best combination of BMDDEDR and geometrical parameters to predict bone maximal load was explored. BMDDXA was used for comparison. Significant moderate to high linear correlations were observed in all regions of the upper femur (femoral neck, Ward’s triangle, trochanter and inter-trochanter) between BMDDEDR and BMDDXA. BMDDEDR of the femoral neck and BMDDXA of the femoral neck predicted maximal load similarly. The best combination of parameters to predict maximal load was BMDDEDR at Ward’s triangle, femoral shaft diameter (FSD) and femoral shaft axis length (FNAL) (r = 0.79, p &lt; 0.05). The study shows that DEDR is a suitable method to determine BMD in vitro and the combination of BMD and geometry improves the prediction of bone maximal load when compared to BMDDEDR of femoral neck or trochanter only. The thesis also includes unpublished data from a preliminary human study. / Tiivistelmä Osteoporoosin diagnosointi ja murtumariskin määrittäminen perustuvat kaksienergisellä röntgenabsorptiometrialla (DXA) mitattavaan luun mineraalitiheyden (BMD) arviointiin. DXA:lla määritetyn luun mineraalitiheyden (BMDDXA) on kuitenkin osoitettu olevan puutteellinen murtumariskin yksilöllisessä ennustamisessa. Digitaalinen röntgenkuvaus (DR) on helpottanut sellaisten kaksienergisten tekniikoiden toteuttamista, joissa luu ja pehmytkudos on eroteltu toisistaan. Kaksienergisen digitaalisen röntgenkuvausmenetelmän (DEDR) soveltamista BMD:n määrittämiseen ei ole tutkittu. BMD:n ja luun massan lisäksi on luun geometrialla vahva vaikutus luun mekaaniseen lujuuteen. Geometriset parametrit voidaan määrittää niin ikään digitaalisista röntgenkuvista. Tässä työssä tutkittiin, pystytäänkö DEDR:llä määrittämään BMD sekä parantaako DEDR:llä mitattujen BMD:n ja geometrian yhdistelmä luun maksimikuormituksen ennustetta. Näin ollen murtuma- ja osteoporoosidiagnoosit voitaisiin tehdä yhdellä tutkimuksella (DEDR), kun nykyisin diagnoosit vaativat sekä digitaalisen röntgenkuvauksen että DXA-tutkimuksen. Poron reisiluut kuvattiin digitaalisen röntgenlaitteen kahdella eri kuvausjännitteellä (79 ja 100 kVp). 79 kVp -kuvista määritettiin myös erilaiset geometriaparametrit. BMD laskettiin DEDR-kuvista (BMDDEDR) DXA:n laskentaperiaatetta käyttäen. BMDDEDR:n kyky ennustaa BMDDXA:a tutkittiin. Maksimikuormituksen selvittämiseksi reisiluut testattiin mekaanisesti aksiaalisuunnassa varren ollessa pystysuorassa asennossa. BMDDEDR- ja geometriaparametreista määritettiin paras yhdistelmä maksimikuorman ennustamiseen. BMDDXA-arvoja käytettiin analysoinnissa vertailun vuoksi. BMDDEDR- ja BMDDXA-arvojen välillä havaittiin merkitsevä keskinkertainen tai korkea korrelaatio kaikissa mielenkiintoalueissa (reisiluun kaula, Wardin kolmio, sarvennoisen alue ja reisiluun varren alue). Wardin kolmiosta mitatun BMD:n (WABMDDEDR), reisiluun varren halkaisijan (FSD) ja reisiluun kaulan kautta kulkevan akselin (FNAL) yhdistelmä ennusti parhaiten luun haurautta (r = 0.79, p &lt; 0.05). Tutkimus osoittaa, että DEDR on sopiva menetelmä BMD:n määrittämiseen tutkimusolosuhteissa ja että BMD:n ja geometrian yhdistelmä parantaa maksimikuormituksen ennustetta pelkästään reisiluun kaulasta tai sarvennoisesta mitattuun BMDDEDR:iin verrattuna. Väitöskirja sisältää myös julkaisemattomia tuloksia alustavista ihmistutkimuksista.

Le groupe des KDIGO a défini un nouveau syndrome regroupant les troubles minéraux et osseux et les calcifications vasculaires au cours de la maladie rénale chronique {TMO-MRC). Les TMO-MRC sont associés à une augmentation du risque de fracture, de calcification vasculaire et à une surmortalité. La quête d'un biomarqueur fiable de la maladie osseuse et des calcifications vasculaires reste le défi du néphrologue. Au cours des dernières années, de nombreuses protéines de l'os ont été associées aux calcifications vasculaires chez les patients urémiques, tels que les phosphatases alcalines osseuses et, plus récemment, la sclérostine. Cette petite protéine est secrétée par l'ostéocyte et inhibe l'ostéoformation en bloquant la voie de signalisation Wnt dans l'ostéoblaste. Il a récemment été suggéré que la sclérostine aurait une activité catabolique sur l'os et serait impliquée dans la déminéralisation du squelette. L'objectif de ce travail était d'étudier la sclérostine au cours de la MRC. Nous avons tout d'abord montré que les concentrations sériques de sclérostine augmentaient avec la baisse du débit de filtration glomérulaire mesurée par la clairance de l'inuline et ce dès le stade 3 de la MRC, indépendamment de l'âge. De plus, cette étude nous a permis de montrer pour la première fois que la phosphorémie était indépendamment et positivement associée à la sclérostine sérique. Ensuite, nous avons retrouvé une association positive et forte entre la concentration sérique de sclérostine et les calcifications vasculaires chez des patients en hémodialyse chronique. Enfin, nous avons montré que les calcifications artérielles étaient significativement associées à une qualité osseuse corticale altérée étudiée en scanner quantitatif de haute résolution. Ces résultats suggèrent que la sclérostine pourrait constituer un messager important dans la relation entre l'os et la paroi vasculaire calcifiée des patients atteints d'une insuffisance rénale chronique terminale / The KDlGO group identified a new syndrome involving mineral and bone disorders and vascular calcification in chronic kidney disease (CKD-MBD}. CKD-MBD are associated with an increased risk of fracture, vascular calcification and increased mortality. The search for a reliable biomarker of bone disease and vascular calcification remains the challenge of the nephrologist. ln recent years, many bone proteins have been associated with vascular calcification in uremic patients, such as bone alkaline phosphatase and more recently sclerostin. This small protein is secreted by the osteocyte and is an inhibitor of bone formation by blocking the Wnt signaling in osteoblasts. lt has recently been suggested that sclerostin has a catabolic activity on bone and is involved in the demineralization of the skeleton. The aim of this research was to study the sclerostin during the course of CKD. We first showed that serum levels of sclerostin increased with the decrease of glomerular filtration rate measured by inulin clearance already from stage 3 chronic kidney disease, regardless of age. Furthermore, in this study, we showed for the first time that serum phosphorus was independently and positively associated with serum sclerostin. Subsequently we found a positive and strong association between serum sclerostin and vascular calcification in maintenance hemodialysis patients. Finally, we have shown that arterial calcification were significantly associated with an altered cortical bone quality studied by high resolution peripheral quantitative computed tomography. These results suggest that sclerostin could be an important messenger in the cross-talk between the bone and the calcified vascular wall in end stage renal disease

Made available in DSpace on 2016-07-18T17:53:16Z (GMT). No. of bitstreams: 1 Leandro Barbosa.pdf: 680328 bytes, checksum: 22ee01e97ffce340763c0803b4b252c2 (MD5) Previous issue date: 2015-04-09 / The objective of this study is to evaluate the effect of manann oligosaccharides (MOS) prebiotics on densitometry parameters of the femur by means of bone densitometry and biomechanical test in rats. 144 growing male rats were used, 23 days old, and 36.7 ± 0.6 grams of body weight were divided into 04 experimental groups (n = 36) and kept in individual cages during the experimental period of 56 days: Group Control (GC); Mos Group 1 (GM1); Mos Group 2 (GM2); and Group 3 Mos (GM3). Densitometric analysis and biomechanical testing of bone mineral content were conducted in four stages: 14, 28, 42 and 56 days after beginning the experiment. Simple linear regressions were adjusted data pairs situation, time of collection (every 14 days) and results of bone mineral content parameters (BMC), bone mineral density (BMD), area (A), energy, maximum strength and stiffness. The regressions set of treatments for each parameter were compared in pairs by the intercept and slope of the straight and revealed significant differences between treatments (P <0.0125) in the area parameters, energy absorbed to the maximum strength and maximum strength. The slope of the lines was higher in groups supplemented with MOS compared to the CG. MOS intake increased bone mineralization, which, in turn, increased the resistance to fracture of the femur in all the biomechanical properties and densitometric studied, perhaps due to an increase in the intestinal absorption of nutrients in rats. Given the beneficial results of this study with growing rats as experimental model, it is suggested that this functional food can be used as a food component enhancing bone health. / O objetivo deste estudo é avaliar o efeito dos aditivos prebióticos do tipo mananoligossacarídeos (MOS) sobre os parâmetros densitométricos e biomecânicos, por meio da densitometria óssea e ensaio biomecânico, respectivamente, de fêmures de ratos. Foram utilizados 144 ratos machos em crescimento, com 23 dias de idade e 36,7 ± 0,6 gramas de massa corporal, divididos em 04 grupos experimentais (n=36) e mantidos em gaiolas individuais durante o período experimental de 56 dias: Grupo Controle (GC); Grupo MOS 1 (GM1); Grupo MOS 2 (GM2); e Grupo MOS 3 (GM3). A análise densitométrica e o ensaio biomecânico do conteúdo mineral ósseo foram realizadas em quatro momentos: 14, 28, 42 e 56 dias após o inicio do experimento. Foram ajustadas regressões lineares simples, situação de pares de dados, momento de coleta (a cada 14 dias) e resultados dos parâmetros do conteúdo mineral ósseo (CMO), densidade mineral óssea (DMO), área (A), energia, força máxima e rigidez. As regressões ajustadas dos tratamentos de cada parâmetro foram comparadas duas a duas pelos interceptos e inclinação das retas e revelaram diferenças significativas entre os tratamentos (P<0,0125) nos parâmetros área, energia absorvida até a força máxima e força máxima. A inclinação das retas foi maior nos grupos suplementados com MOS em relação ao GC. A ingestão de MOS resultou em uma maior mineralização óssea, o que, por sua vez, aumentou a resistência à fratura do fêmur em todas as propriedades biomecânicas e densitométricas estudadas, talvez devido a um aumento da absorção intestinal de nutrientes nos ratos. Diante dos benéficos resultados obtidos nesse estudo com ratos em crescimento, como modelo experimental, sugere-se que este alimento funcional possa ser utilizado como um componente alimentar intensificador da saúde óssea, particularmente nos dias de hoje, em que a expectativa de vida aumenta exponencialmente.

Bone is a plastic tissue, changing in density and size with different levels of stress. Furthermore, it appears that BMD is altered in a site specific manner. However, BMD has not been studied extensively in all types of athletes, particularly well trained strengthpower athletes, such as throwers. The pwpose of this study was to examine the BMD of USA Division I collegiate throwers (shot put, discus, etc.). BMD was compared to normative data and to different athletes. Measures of whole body maximum strength and throwing performance were correlated with BMDs. Potential right/left side and sex differences were examined. Athletes were 4 males, 3 females age 19.9 ± 0.9 years. BMD was measured with a DEXA Maximum isometric strength was measured using a midthigh pull standing on a force plate. Force time-curves were generated during the strength tests. Peale force (PF) and normalized pealc force (PFa) were correlated with BMDs. Comparison indicates throwers have denser bones compared to normative data and compared to other types of athletes. Male throwers tend to have greater total body BMD than female throwers (p < 0.05). Dominant arm showed slightly greater BMD compared to non-dominant (p < 0.05). Furthermore, BMD is related to PF (r = 0.68) and PFa (r = 0.56). Throwers have greater BMD's than non-athletes or most other types of athletes. However, throwers showed only a small indication of sidedness. These observations likely stem from their training program (whole body heavy loading).

Introduction: The inflammation plays the essential role in the bone loss in juvenile idiopathic arthritis (JIA). Proinflammatory cytokines and also glucocorticoids (GCs) may activate bone resorption by osteoclasts. Simultaneously, bone formation can be attenuated, especially by inhibitors of proteins, which control the osteoblast differentiation. The aim was to verify the hypothesis that in patients with highly active JIA, reduction of bone formation via Wingless (Wnt) proteins inhibitors - Dickkopf 1 (Dkk-1) and sclerostin could be found. Except the densitometry measurements of bone and lean mass, we assessed markers of disease activity, bone metabolism and remodeling in young adult patients with JIA before and during 2 years of anti TNFα (tumour necrosis factor α) treatment, which decreases disease activity. Results: In patients with JIA before antiTNFα treatment, bone mineral density (BMD, g/cmš) was significantly reduced compared to controls. Values of BMD and body composition in JIA significantly depended on disease duration and GCs treatment. Serum concentration of sclerostin was significantly elevated in JIA compared to values in healthy controls. Values of the other monitored markers did not differ between JIA and controls. In patients with JIA, Dkk-1 correlated positively with C-reactive...