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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

The effects of vitamin D supplementation on prostate cancer

Cosby, Grier 10 May 2024 (has links) (PDF)
This systematic review's goal is to evaluate the efficacy of vitamin D supplementation in helping to manage the nutritional needs of patients diagnosed with prostate cancer. A systematic literature search following the PRISMA guidelines using Scopus, PubMed, and Cochrane databases was conducted to review randomized controlled trials and interventional studies up to 2023. The search strategy targeted randomized controlled trials and intervention studies. The selection process involved screening for study characteristics (study design), participant demographics (prostate cancer patients receiving treatment), intervention details (vitamin D assessment methods, dosages), outcome measures (progression, prognosis, quality of life), and risk estimates (hazard ratios, odds ratios, relative risks) along with covariates adjusted for in the analysis. Data analysis and synthesis included studies assessing vitamin D supplementation's impact on prostate-specific antigen (PSA) levels, tumor progression, osteomalacia, overall survival rates, and quality of life assessments. The literature search yielded a total of 3575 documents. After a preliminary screening of titles and abstracts, 34 full-text studies were examined. In total, nine studies were determined to meet the inclusion criteria. The findings of nine studies suggest a modest but significant association between vitamin D supplementation, reduced PSA levels, slower progression of localized prostate cancer, and improved bone loss. Due to the various treatment options, the overall effects of supplementation on advanced prostate cancer and overall survival were inconclusive. However, this research highlights the potential role of vitamin D in prostate cancer management.
112

The female athlete triad profile of elite Kenyan runners and its future health implications / Yasmin Goodwin

Goodwin, Yasmin January 2014 (has links)
The female athlete triad (FAT or the TRIAD) is a complex syndrome arising from associations among the trio of energy availability (EA), menstrual function (MF) and bone mineral density (BMD) along their respective continuums from health to disease state. It has been recognized that women whose energy intake (EI) does not meet the energy requirements for physiological functions subsequent to participation in exercise and physical activity could have low EA. In the TRIAD, low EA, an initiator in menstrual dysfunction (MD) and concomitant hypoestrogenism, indirectly results in low BMD. Therefore, the purpose of this study was to: (i) establish the status of EA, MF and BMD among elite Kenyan female athletes and non-athletes, (ii) explore associations between EA and MF in elite Kenyan female athletes and non-athletes, (iii) determine the relationships of EA and MF to BMD in elite Kenyan female athletes and non-athletes, and (iv) to determine the profile of the female athlete triad in elite Kenyan distance athletes and in non-athletes. Measurements of EA, MF and BMD were undertaken in 39 female participants (Middle distance athletes =12, Long distance athletes=13, Non-athletes=14). Energy intake minus exercise energy expenditure (EEE) and the remnant normalized to fat free mass (FFM) determined EA. Energy availability was determined through weight of all food and liquid consumed over three consecutive days. Exercise energy expenditure was determined after isolating and deducting energy expended in exercise or physical activity above lifestyle level from the total energy expenditure output as measured by Actigraph GT3X+. Fat free mass and BMD were assessed using dual energy x-ray absorptiometry (DXA). A nine-month daily temperature-menstrual diary was used to evaluate menstrual status. In addition, since psychological eating behaviour practice (EBP) contributes to low EA, the Eating Disorder Examination Questionnaire (EDE-Q) was used to determine presence of such practice among the participants and their relationship to EA. Overall, EA below 45 kcal.kgFFM-1.d-1 was found in 61.53% of the participants (athletes=28.07±11.45kcal.kgFFM-1.d-1, non-athletes=56.97±21.38kcal.kgFMM-1.d-1). The ANOVA showed that there was a significant difference (p<0.001) in EA among the long and middle distance runners and non-athletes; and the Tukey‘s HSD revealed that the source of the difference were the non-athletes. Results of the EDE-Q showed almost negligible presence of psychopathological eating behaviour practice among the Kenyan participants. None of the TRIAD components showed significant relationship with EBP. Results of MF showed that whereas none of the athletes presented with amenorrhea, oligomenorrhea was present among 40% athletes and 14.3% non-athletes, and amenorrhea among 14.3% non-athletes. However, there was no significant difference between athletes and non-athletes in MF. Low BMD was seen in 76% of the athletes and among 86% of the non-athletes. The analysis did not show significant difference in BMD Z-scores between athletes and non-athletes. The analysis did not show any significant association between EA and MF among the participants. The only significant relation of EA to any BMD dimension measured was between EA and total BMD in the long distance runners (r=0.560; p=.046). Significant relationship (rho=0.497; p=.001) was found between MF and BMD Z-scores among the athletes with middle distance highlighting the relationship further (rho=0.632; p=.027). Overall, the binary logistic regression revealed that MF did not predict BMD (OR=4.07, 95% CI, 0.8-20.7, p=.091). Overall, 10% of the participants (athletes=4, long distance athletes =3, middle distance athletes=1, non-athletes=0) showed simultaneous presence of all three components of the TRIAD. The independent sample t-test showed a significant difference (t=5.860; p=<.001) in the prevalence of the TRIAD between athletes and non-athletes. / PhD (Human Movement Science), North-West University, Potchefstroom Campus, 2014
113

The female athlete triad profile of elite Kenyan runners and its future health implications / Yasmin Goodwin

Goodwin, Yasmin January 2014 (has links)
The female athlete triad (FAT or the TRIAD) is a complex syndrome arising from associations among the trio of energy availability (EA), menstrual function (MF) and bone mineral density (BMD) along their respective continuums from health to disease state. It has been recognized that women whose energy intake (EI) does not meet the energy requirements for physiological functions subsequent to participation in exercise and physical activity could have low EA. In the TRIAD, low EA, an initiator in menstrual dysfunction (MD) and concomitant hypoestrogenism, indirectly results in low BMD. Therefore, the purpose of this study was to: (i) establish the status of EA, MF and BMD among elite Kenyan female athletes and non-athletes, (ii) explore associations between EA and MF in elite Kenyan female athletes and non-athletes, (iii) determine the relationships of EA and MF to BMD in elite Kenyan female athletes and non-athletes, and (iv) to determine the profile of the female athlete triad in elite Kenyan distance athletes and in non-athletes. Measurements of EA, MF and BMD were undertaken in 39 female participants (Middle distance athletes =12, Long distance athletes=13, Non-athletes=14). Energy intake minus exercise energy expenditure (EEE) and the remnant normalized to fat free mass (FFM) determined EA. Energy availability was determined through weight of all food and liquid consumed over three consecutive days. Exercise energy expenditure was determined after isolating and deducting energy expended in exercise or physical activity above lifestyle level from the total energy expenditure output as measured by Actigraph GT3X+. Fat free mass and BMD were assessed using dual energy x-ray absorptiometry (DXA). A nine-month daily temperature-menstrual diary was used to evaluate menstrual status. In addition, since psychological eating behaviour practice (EBP) contributes to low EA, the Eating Disorder Examination Questionnaire (EDE-Q) was used to determine presence of such practice among the participants and their relationship to EA. Overall, EA below 45 kcal.kgFFM-1.d-1 was found in 61.53% of the participants (athletes=28.07±11.45kcal.kgFFM-1.d-1, non-athletes=56.97±21.38kcal.kgFMM-1.d-1). The ANOVA showed that there was a significant difference (p<0.001) in EA among the long and middle distance runners and non-athletes; and the Tukey‘s HSD revealed that the source of the difference were the non-athletes. Results of the EDE-Q showed almost negligible presence of psychopathological eating behaviour practice among the Kenyan participants. None of the TRIAD components showed significant relationship with EBP. Results of MF showed that whereas none of the athletes presented with amenorrhea, oligomenorrhea was present among 40% athletes and 14.3% non-athletes, and amenorrhea among 14.3% non-athletes. However, there was no significant difference between athletes and non-athletes in MF. Low BMD was seen in 76% of the athletes and among 86% of the non-athletes. The analysis did not show significant difference in BMD Z-scores between athletes and non-athletes. The analysis did not show any significant association between EA and MF among the participants. The only significant relation of EA to any BMD dimension measured was between EA and total BMD in the long distance runners (r=0.560; p=.046). Significant relationship (rho=0.497; p=.001) was found between MF and BMD Z-scores among the athletes with middle distance highlighting the relationship further (rho=0.632; p=.027). Overall, the binary logistic regression revealed that MF did not predict BMD (OR=4.07, 95% CI, 0.8-20.7, p=.091). Overall, 10% of the participants (athletes=4, long distance athletes =3, middle distance athletes=1, non-athletes=0) showed simultaneous presence of all three components of the TRIAD. The independent sample t-test showed a significant difference (t=5.860; p=<.001) in the prevalence of the TRIAD between athletes and non-athletes. / PhD (Human Movement Science), North-West University, Potchefstroom Campus, 2014
114

A comparative study of the determinants of bone strength and the propensity to falls in black and white South African women

Conradie, Magda 12 1900 (has links)
Thesis (DMed)--Stellenbosch University, 2008. / The comparative study presented in this dissertation specifically aimed to assess fracture risk in black (Xhosa) and white South African women by evaluating known determinants of bone strength as well as the propensity to falls. We thus compared the prevalence of clinical (historic) risk factors for osteoporosis, measured and compared vertebral and femoral bone mineral density (BMD) employing dual energy X-ray absorptiometry (DEXA), ultrasound variables using the Sahara sonometer, serum parathyroid hormone (PTH) and 25-OH Vitamin D, mineral homeostasis and modern biochemical markers of bone turnover, bone geometry and the propensity to falls. Finally, we determined the prevalence of vertebral fractures in these black and white South African females. 1. Significant ethnic differences were noted in the presence and frequency of historical clinical and lifestyle risk factors for osteoporosis. Blacks were heavier and shorter, they consumed less calcium, were more inactive, preferred depot-medroxyprogesterone acetate as contraceptive agent and were of higher parity. Whites smoked more, preferred oral oestrogen containing contraceptive tablets and were more likely to have a positive family history of osteoporosis. Hormone therapy was used almost exclusively by postmenopausal whites. Inter-ethnic differences in weight, physical activity and high parity was most marked in the older subjects. 2. We found that peak spinal BMD was lower, but peak femoral BMD similar or higher (depending on the specific proximal femoral site measured) in black South-African females compared with whites. The lower peak spinal BMD was mainly attributed to lower BMD’s in the subgroup of black females with normal to low body weight, indicating that obesity either protected black females against a low spinal BMD or enhanced optimal attainment of bone mineral. An apparent slower rate of decline in both spinal- and femoral BMD with ageing was noted in the black females compared with whites in this cross-sectional study – an observation which will require confirmation in longitudinal, follow-up studies. This resulted in similar spinal BMD values in postmenopausal blacks and whites, but significantly higher femoral BMD measurements in blacks. The volumetric calculation of bone mineral apparent density (BMAD) at the lumbar spine and femoral neck yielded similar results to that of BMD. Spinal BMAD was similar in blacks and whites and femoral neck BMAD was consistently higher in all the menopausal subgroups studied. Weight significantly correlated with peak- and postmenopausal BMD at all sites in the black and white female cohorts. Greater and better maintained body weight may be partially responsible for slower rates of bone loss observed in black postmenopausal females. Most of the observed ethnic difference in BMD was, in fact, explained by differences in body weight between the two cohorts and not by ethnicity per se. 3. A low body weight and advanced age was identified as by far the most informative individual clinical risk factors for osteopenia in our black and white females, whereas physical inactivity was also identified as an important individual risk factor in blacks only. Risk assessment tools, developed and validated in Asian and European populations, demonstrated poor sensitivity for identification of South African women at increased risk of osteopenia. The osteoporosis risk assessment instrument (ORAI) showed the best results, with sensitivities to identify osteopenic whites at most skeletal sites approaching 80% (78% - 81%). The risk assessment tool scores appear to be inappropriate for our larger sized study cohort, especially our black subjects, thus resulting in incorrect risk stratification and poor test sensitivity. General discriminant analysis identified certain risk factor subsets for combined prediction of osteopenia in blacks and whites. These risk factor subsets were more sensitive to identify osteopenia in blacks at all skeletal sites, compared with the risk assessment tools described in the literature. 4. Higher ultrasonographically measured broadband ultrasound attenuation (BUA) and speed of sound (SOS) values were documented in our elderly blacks compared with whites, even after correction for differences in DEXA determined BMD at the spine and proximal femoral sites. BUA and SOS showed no decline with ageing in blacks, in contrast to an apparent significant deterioration in both parameters in ageing whites. If these quantitative ultrasound (QUS) parameters do measure qualitative properties of bone in our black population, independent of BMD as has been suggested in previous work in Caucasian populations, the higher values documented in elderly blacks imply better preservation of bone quality in ageing blacks compared with whites. The correlation between QUS calcaneal BMD and DEXA measured BMD at the hip and spine was modest at best. QUS calcaneal BMD was therefore unable to predict DEXA measured BMD at clinically important fracture sites in our study population. 5. Bone turnover, as assessed biochemically, was similar in the total pre- and postmenopausal black and white cohorts, but bone turnover rates appeared to differ with ageing between the two racial groups. A lower bone turnover rate was noted in blacks at the time of the menopausal transition and is consistent with the finding of a lower percentage bone loss at femoral sites at this time in blacks compared with whites. Bone turnover only increased in ageing postmenopausal blacks, and this could be ascribed, at least in part, to the observed negative calcium balance and the more pronounced secondary hyperparathyroidism noted in blacks. Deleterious effects of secondary hyperparathyroidism on bone mineral density at the proximal femoral sites were demonstrated in our postmenopausal blacks and contest the idea of an absolute skeletal resistance to the action of PTH in blacks. The increase in bone turnover and the presence of secondary hyperparathyroidism due to a negative calcium balance may thus potentially aggravate bone loss in ageing blacks, especially at proximal femoral sites. 6. Shorter, adult black women have a significantly shorter hip axis length (HAL) than whites. This geometric feature has been documented to protect against hip fracture. The approximately one standard deviation (SD) difference in HAL between our blacks and whites may therefore significantly contribute to the lower hip fracture rate previously reported in South African black females compared with whites. Average vertebral size was, however, smaller in black females and fail to explain the apparent lower vertebral fracture risk previously reported in this population. Racial differences in vertebral dimensions (height, width) and/or other qualitative bone properties as suggested by our QUS data may, however, account for different vertebral fracture rates in white and black women – that is, if such a difference in fact exists. 7. The number of women with a history of falls was similar in our black and white cohorts, and in both ethnic groups the risk of falling increased with age. There is a suggestion that the nature of falls in our black and white postmenopausal females may differ, but this will have to be confirmed in a larger study. Fallers in our postmenopausal study population were more likely to have osteoporosis than non-fallers. Postmenopausal blacks in our study demonstrated poorer outcomes regarding neuromuscular function, Vitamin D status and visual contrast testing and were shown to be more inactive with ageing compared with whites. An increased fall tendency amongst the black females could not however be documented in this small study. Quadriceps weakness and slower reaction time indicated an increased fall risk amongst whites, but were unable to distinguish black female fallers from non-fallers. 8. Vertebral fractures occurred in a similar percentage of postmenopausal blacks (11.5%) and whites (8.1%) in our study. Proximal femoral BMD best identified black and white vertebral fracture cases in this study. Quite a number of other risk factors i.e. physical inactivity, alcohol-intake, poorer physical performance test results and a longer HAL were more frequent in the white fracture cases and could therefore serve as markers of increased fracture risk, although not necessarily implicated in the pathophysiology of OP or falls. However, in blacks, only femoral BMD served as risk factor. Similar risk factors for blacks and whites cannot therefore be assumed and is deserving of further study. White fracture cases did not fall more despite lower 25-OH-Vitamin D, poorer physical performance and lower activity levels than non-fracture cases. Calcaneal ultrasonography and biochemical parameters of bone turnover were similar in fracture and non-fracture cases in both ethnic groups. Our study data on vertebral fractures in this cohort of urbanized blacks thus cautions against the belief that blacks are not at risk of sustaining vertebral compression fractures and emphasize the need for further studies to better define fracture prevalence in the different ethnic populations of South Africa. 9. In our study, hormone therapy in postmenopausal white women improved bone strength parameters and reduced fall risk. In hormone treated whites compared with non-hormone users, a higher BMD at the spine and proximal femur as determined by DEXA were documented and all QUS measurements were also significantly higher. The biochemically determined bone turnover rate, as reflected by serum osteocalcin levels, was lower in hormone users. Fall frequency was lower in the older hormone treated women (≥ 60yrs) and greater quadriceps strength and reduced lateral sway was noted. Only one patient amongst the hormone users (2%) had radiological evidence of vertebral fractures compared with four patients (6%) amongst the never-users. As hormone therapy was used almost exclusively by whites in this study population, the impact of hormone therapy on postmenopausal black study subjects could not be assessed.
115

Influence de la surcharge pondérale sur la densité minérale osseuse et la géométrie osseuse chez des adolescents et des jeunes libanais / Influence of being overweight on bone mineral density and bone geometry in a group of Lebanese adolescents and young adults

El Hage, Zaher 03 July 2013 (has links)
Les buts de cette thèse étaient d'explorer les effets de l'obésité et du surpoids sur le contenu minéral osseux (CMO), la densité minérale osseuse (DMO) et la géométrie osseuse de la hanche ches des adolescents et des jeunes adultes libanais. 131 sujets libanais agés de 13 à 30 ans ont acceptés de participer à cette étude (67 de sexe masculin et 64 de sexe féminin) et ont donné leur consentement éclairé. Le poids et la taille ont été mesurés et l'indice de masse corporelle (IMC) a été calculé. La composition corporelle, le CMO du corps entier (CE), la DMO CE, la DMO du rachis lombaire (L2-L4), la DMO de la hanche et la DMO de l'avant-bras ont été mesuréses par la DXA. La géométrie osseuse de la hanche a été évaluée par le logiciel Hip Structure Analysis (HSA). La surface de la section transversale (CSA), le moment d'inertie de la surface transversale (CSMI), le module de section (Z), l'épaisseur corticale (CT) et le buckling ratio (BR) ont été ainsi mesurés par le logiciel HSA. Dans les deux sexes, l'obésité et le surpoids étaient associés à une augmentation des valeurs absolues de CMO, de DMO et d'indicecs géométriques de résistance osseuse (CSA et Z) au niveau de la hanche. Chez les sujets de sexe masculin, le CMO CE, le rapport CMO CE/taille, la DMO CE et la DMO du Radius ultra-distal étaient significativement inférieurs chez le groupe obèse par rapport aux groupes en surpoids et normo-pondérés après ajustement pour le poids (en utilisant une analyse de covariance). Chez les sujets de sexe féminin, après ajustement pour le poids (en utilisant une analyse de covariance), la DMO du rachis lombaire était inférieure chez le groupe obèse par rapport au groupe normo-pondéré alors qu'il n'y avait aucune différence entre les trois groupes (obèse, en surpoids et normo-pondéré) au niveau des indices géométriques de résistance osseuse de la hanche. Cette thèse montre donc que la DMO de certains sites osseux n'est pas correctement adaptée à l'excès de poids chez les jeunes obèses. / The aims of this thesis were to explore the effects of obesity and overweight on bone mineral content (BMC), bone mineral density (BMD) and hip geometry in a group of Lebanese adolescents and young adults. 131 Lebanese subjects (67males and 64 female) whose ages range between 13 and 30 years participated in this study. Informed written consent was obtained from participants. Weight and height were measured, and body mass index (BMI) was calculated. Body composition, whole body bone mineral content (WB BMC), whole body bone mineral density (WB BMD), lumbar spine bone mineral density (L2-L4 BMD), hip BMD and forearm BMD were measured by DXA. To evaluate hip bone strength, DXA scans were analyzed by the hip structure analysis (HSA) program. Cross-sectional area (CSA), section modulus (Z), cross-sectional moment of inertia (CSMI), cortical thickness (CT) and buckling ratio (BR) were measured from hip bone mass profiles using the HSA software. In both sexes, obesity and overweight were associated with higher crude BMC, BMD and geometric indices of hip bone strengh values (CSA and Z). In males, obese group displayed lower WB BMC, WB BMC/height, WB BMD and ultra-distal Radius BMD values in comparison to overweight and normal-weight groups after adjustement for weight (using a one-way analysis of covariance). In females, after adjusting for body weight (using a one-way analysis of covariance), lumbar spine BMD was lower in the obese group compared to the normal-weight group while there were no significant differences among the three groups (obses, overweight and normal-weight) regarding geometric indicesof hip bone strength. This study shows that BMD of some skeletal sites is not well adapted to the increased body weight in young obese.
116

Avaliação da composição corporal e densidade mineral ósseo em mulheres com artrite reumatóide / Evaluation of body composition and body mineral density in women with rheumatoid arthritis

Silva, Raissa Gomes da 21 March 2007 (has links)
INTRODUÇÃO: A diminuição da massa óssea e mudanças na composição corporal são comuns em pacientes com artrite reumatóide, particularmente nos usuários de glicocorticóide (GC). OBJETIVO: Analisar o comprometimento dos componentes da composição corporal e densidade mineral óssea (DMO) na artrite reumatóide (AR) e seus aspectos clínicos. MÉTODOS: 83 mulheres com AR realizaram densitometria óssea para análise de massa óssea total e regional e estudo da composição corporal (CC). Além disso, foram submetidas à realização laboratorial de provas inflamatórias, dosagem de fator reumatóide e aplicados questionários para avaliação da atividade da doença, classe funcional, atividade física, e inquérito alimentar. RESULTADOS: A prevalência de osteoporose nas pacientes menopausadas foi de 21,4%, 46,4% com osteopenia e 32,1% com valores normais e ocorreu de forma semelhante em coluna lombar e colo do fêmur. As mulheres na pré-menopausa apresentaram maiores valores nas médias de DMO. A idade teve efeito negativo nas medidas DMO e de CC enquanto que o índice de massa corpórea (IMC) mostrou efeito positivo nestas variáveis. A atividade física apresentou efeito positivo na DMO de fêmur total. A duração da AR teve efeito negativo na DMO de coluna lombar. O GC foi o determinante negativo na massa magra total e aumentou o percentual de gordura. CONCLUSÕES: O achado de valores reduzidos de DMO sugere que devam ser aplicadas medidas para a prevenção e tratamento de osteoporose. A doença (AR) também influenciou negativamente a DMO nestas pacientes e a utilização de GC modificou a CC, reduzindo a massa muscular e aumentando o percentual de gordura. A preservação da massa muscular é importante ao equilíbrio das pacientes, com conseqüente diminuição de quedas e futuras fraturas. / INTRODUCTION: The reduction of bone mass and changes in body compositions are usual in patients with rheumatoid arthritis specialty in users of glucocorticoid (GC). OBJECTIVE: To evaluate the bone mineral density (BMD) and body composition (BC) including its correlation to factors of rheumatoid arthritis (RA) and clinics concerns. METHODS: BMD and body composition (total and regional) were measured by densitometry in 83 patients with RA. Furthermore, it was performed laboratory exams (rheumatoid factor, inflammatory exams) and activity of disease, functional class, physical activity and alimentary data were colleted by specific questionnaires. RESULTS: The prevalence of osteoporosis in menopausal patients was 21,4%, 46,4% of osteopenia and 32,1% were normal and osteoporosis was similar in lumbar spine and femoral neck. Premenopausal women had the biggest values of BMD medias. Dose of GC was negative determinant of total lean mass and made positive effect in total fat percentual. Age made negative effect in BMD and body composition. BMI showed positive effect in all CC variables. The physical activity made positive effect in BMD in total femur. The RA duration had negative effect in BMD in lumbar spine. CONCLUSIONS: The finding of low BMD suggests a better approach to prevention and treatment. The disease (RA) also made a negative influence in BMD in these patients and the use of GC cause changes in body composition, with reduction in lean mass and improvement of total fat percentual. Recommendations to preservation of lean mass are important to reduction of falls and consequent diminution of fractures.
117

Caracterização de tecido ósseo por ultra-som para o diagnóstico de osteoporose. / Assessment of bony tissue by ultrasound for osteoporosis diagnosis.

Alves, Jose Marcos 02 August 1996 (has links)
A caracterização de tecido ósseo por ultra-som para o diagnóstico de osteoporose tem sido investigada como uma alternativa a densitometria óssea baseada em radiação ionizante. A interação do ultra-som com o tecido ósseo é fundamentalmente diferente da que ocorre com a energia ionizante. O potencial da técnica ultra-sônica baseia-se nos efeitos sobre a propagação do campo acústico causados pela estrutura, composição e massa do tecido que está sendo investigado. Quatro estudos in-vitro e um estudo clínico estão descritos neste trabalho. O primeiro estudo in-vitro compara a correlação entre medidas ultra-sônicas e de densidade mineral óssea (em g/cm3) em tecido trabecular humano e bovino. A velocidade e atenuação ultra-sônicas em amostras ósseas foram determinadas pela técnica de inserção convencional (modo de transmissão) e a medida de densidade mineral óssea foi realizada por absortometria de um fóton (SPA). O mecanismo de interação do ultra-som com osso trabecular é pouco conhecido. O segundo estudo in-vitro investigou como a presença da medula óssea afeta as medidas de velocidade e atenuação. As correlações entre medidas ultrasônicas e de densidade mineral óssea (em g/cm3) por SPA, com e sem a presença da medula óssea, são também determinadas. A medida ultra-sônica de inserção convencional é comparada a medida de inserção por contato. O terceiro estudo in-vitro investigou em amostras de calcâneo as correlações entre medidas ultra-sônicas e de densidade mineral óssea (em g/cm3 e em g/cm2) por SPA. A determinação da densidade mineral Óssea em g/cm2 (BMD) a partir de medidas ultra-sônicas nas amostras foi pela primeira vez investigada, utilizando-se uma técnica de regressão linear univariável e multivariável e uma técnica multivariável não-linear baseada em redes neurais. Um novo parâmetro, baseado na média da frequência instantânea (MIF) do sinal da amostra e de referência, foi proposto para caracterizar o tecido ósseo devido a sua alta correlação com a atenuação. O efeito das corticais ósseas do calcâneo nas medidas ultra-sônicas é pouco conhecido. O quarto estudo in-vitro determinou a correlação entre medidas ultrasônicas e de densidade mineral óssea (em g/cm3) por SPA, com e sem a presença das corticais ósseas. Finalmente, no estudo clínico foram determinadas as correlações entre medidas ultra-sônicas no calcanhar e de densidade mineral óssea por DEXA (em g/cm2) no cólo femoral. A determinação da densidade óssea a partir de medidas ultra-sônicas no calcanhar foi pela primeira vez investigada, utilizando-se uma técnica de regressão linear univariável e multivariável e uma técnica multivariável não-linear baseada em redes neurais. / Ultrasonic assessment of bone for managing osteoporosis has been investigated as an alternative to radition-based bone densitometry technology. In contrast with the ionizing electromagnetic radiation of such clinical bone densitometric technique, ultrasound is a mechanical wave and thus interacts with bone in a fundamentally distinct manner. Ultrasound is viewed as having great potential for assessing bone since its propagation is affected by the structure, composition, and mass of the bone tissue being interrogated. Four in-vitro and one clinical study are reported in this work. In the first in-vitro study a comparison is reported on the ultrasonic assessment of human trabecular and bovine trabecular bone samples. Both ultrasonic velocity and attenuation were evaluated through a standard transmission insertion technique and correlated with bone mineral density (in g/cm3 ) as determined with single photon absorptiometry (SPA). There is a relatively limited understanding of how ultrasound interacts with cancellous bone. One potentially model leads analytically to the demonstration that ultrasound propagation through bone is dependent on several factors, including the properties of the fluid, which saturates the pores of the cancellous bone tissue. The second in-vitro study was carried out to assess how the presence of marrow affects the velocity and attenuation measurements. The correlation between ultrasonic and densitometric measurements (in g/cm3) by SPA, with and without the bone marrow, are also determined. A second part of this study compared the measurements of ultrasonic attenuation and velocity on bovine cancellous bone samples using a standard insertion technique with those obtained using a contac method. The thrid in-vitro study with the calcis trabecular samples investigated the correlations between ultrasonic measurements and bone mineral density (in g/cm3 e em g/cm2) as measured by SPA. A nonlinear multivariate estimation technique based on neural network was the first time investigated to determine the ability of ultrasonic measurements to estimate bone mineral density in g/cm2 (BMD). A linear univariate and multivariate estimation of BMD was compared with the neural network approach. A new parameter to characterize the trabecular bone is been proposed, which is based on the mean instantaneous frequency (MIF) of the sample and reference signals after transmission through the os calcis. It was founded a high correlation between MIF and the attenuation (BUA). Little is known about the effect of the os calcis cortical shell on ultrasonic measurements. The fourth in-vitro study with os calcis samples determined the correlation between ultrasonic and densitometric measurements (in g/cm3) by SPA with and without the cortical shell. Finally, a nonlinear multivariate estimation technique based on neural network was the first time investigated to determine the ability of clinical ultrasonic measurements in the heel to estimate bone mineral density (BMD) in the femoral neck. A linear univariate and multivariate estimation to predict BMD in patients is also compared with the neural network approach.
118

Efeito do metotrexato, do corticosteróide e do ácido zoledrônico na osseointegração de implantes de titânio em um modelo de tíbias de coelhos / Osseointegration of titanium implants in the rabbit tibia model: effect of methotrexate, corticosteroid and zoledronic acid

Carvas, Janaina Santos Badin 10 October 2007 (has links)
No presente estudo avaliamos a influência do Metotrexato (MTX-3mg/kg/semana) e do Corticosteróide (CE- prednisona 1,05 mg/kg/semana), ministrados de forma isolada, associados entre si, ou associados ao Ácido Folínico (AF- 0,25 mg/kg/semana) e ao Ácido Zoledrônico (ZOL- 0,1mg/kg dose única) respectivamente, na osseointegração de implantes de titânio realizados 6 semanas após o início da administração das drogas, em coelhos NZW. Os animais (2,67 ± 0,67 Kg) foram tratados durante um total de 18 semanas com solução salina (CTL; n=6), MTX (n=6), CE (n=8), MTX-CE (n=6), MTX-AF (n=6) e CE-ZOL (n=6). Foram realizadas análises de densitometria mineral óssea (DMO) na tíbia e na coluna antes e após os tratamentos para avaliação da variação da DMO (Delta DMO). Os resultados revelaram perda de osso cortical nos grupos tratados com CE (Delta DMO tíbia: 0,018 ± 0,010 vs CTL: 0,040 ± 0,011 p= 0,001; Delta DMO coluna: 0,004± 0,011 vs CTL: 0,055 ± 0,009 p= 0,009). A adição de ZOL ao CE reverteu a perda de DMO (Delta DMO tíbia: 0,027 ± 0,003 p= 0,002 em relação ao CE; Delta DMO coluna: 0,043 ± 0,011 p= 0,02 em relação ao CE). O tratamento com MTX não promoveu alteração da DMO. As análises histomorfométricas das tíbias com e sem o implante, foram realizadas 12 semanas após a colocação dos implantes, e os resultados mostraram uma redução de espessura cortical e de tecido ósseo em função do tratamento com CE sendo que a adição de ZOL reverteu também esse parâmetro. Da mesma forma, o percentual de contato entre osso e o implante foi alterado pelo tratamento com CE (CE: 25,98% vs. CTL: 42,40%; p= 0,013) e o ZOL reverteu esse efeito (CE- ZOL: 38,95% vs. CE: 25,98%; p= 0,014). Em conjunto, nossos resultados mostraram que a terapia com MTX não alterou a osseointegração de implantes de titânio, enquanto que o CE promoveu uma diminuição de contato entre osso e implante que foi revertida pela administração de ZOL, comprovando a eficácia terapêutica dessa associação. / In this study we evaluated the influence of Methotrexate (MTX- 3mg/kg/week) and Corticosteroid (CE- prednisona 1, 05 mg/kg/week), alone and in association with Folinic Acid (FA- 0, 25 mg/kg/week) and Zoledronic Acid (ZOL-0,1mg/kg/week) respectively, on osseointegration of titanium dental implants performed 6 weeks after treatment started in adult male NZW rabbits. Six animals in each group and eight in CE, were treated with the drugs during 18 weeks with exception of ZOL, which was infused as a single dose, at the moment of surgery. Dual-energy X-ray absorptiometryies were performed before and after treatment to determine bone mineral density alterations (Delta BMD). After 12 weeks post-implant placement, the animals were sacrificed for histomorphometric analysis. The BMD was significantly reduced by treatment with CE (Delta tibia: 0.018±0.010 vs CTL: 0.040±0.011; Delta lumbar: 0.004±0.011 vs CTL: 0.055±0.009), with recovery of BMD after ZOL administration (Delta tibia: 0,027± 0,003 vs CE: 0,018±0,010; Delta lumbar: 0.043±0.011 vs CE: 0.004±0.011). The BMD was not altered by MTX treatment or MTX-FA. The histomorphometric analysis revealed cortical bone loss and reduction in bone tissue in tibia in animals treated with CE, and these parameters were reversed by ZOL. Similarly, the percentage of bone to implant contact was reduced in the group treated with CE (CE: 25.98% vs. CTL: 42.40%; p=0.013), and reverted by ZOL (CE+ZOL: 38.95% vs. CE: 25.98%; p=0.014).The MTX and MTX-FA treatments did not alter osseointegration of the implant (35.09% and 35.92% respectively). Together our results showed that therapy with MTX did not interfere on osseointegration of titanium implants, while the CE reduced the bone to implant contact. ZOL administration reversed this effect, showing the therapeutic importance of this association.
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Osteoporose nach Lebertransplantation:Gewicht von Lebergrunderkrankung, Anabolen Sexualhormonen, Immunsuppression sowie Therapie mit Calcitriol als Monotherapeutikum und in Kombination mit Kalzium und Natriumfluorid

Kubo, Andreas 14 January 2000 (has links)
Die sekundäre Osteoporose ist eine der häufigsten mit der Lebertransplantation verbundenen Komplikationen. Sie ist mit spezifischen chronischen Lebererkrankungen assoziiert und manifestiert sich in ihrem ausgeprägtesten Stadium in Form von Frakturen nicht selten nach der Lebertransplantation (LTX). Management und Therapie der Osteoporose stellen noch heute ein wesentliches Problem bei Lebertransplantatempfängern dar. Das erste Ziel dieser Studie bestand in der Erfassung der Bedeutsamkeit verschiedener spezifischer Lebererkrankungen, des Einflusses von anabolen Sexualhormonen und Immunosuppression auf den Knochensubstanzverlust bei Patienten mit LTX. Das zweite Ziel dieser Studie bestand in der Abschätzung des therapeutischen Effektes von Calcitriol (1,25 (OH)2D3) in niedrigen Dosierungen zu 0,25 µg und 0,5 µg als Monotherapeutikum oder in Kombination mit 1000 mg Kalzium (Ca) bei leichter oder mäßiger Osteoporose. Patienten mit schwerer Osteoporose wurden mit einer Dreifachkombination bestehend aus 0,5 µg Calcitriol, 1000 mg Ca und 25 mg Natriumfluorid behandelt. Von 860 Patienten, die sich im Zeitraum von 1988 bis 1996 einer Lebertransplantation unterzogen, wurden insgesamt 509 Patienten (256 Männer, 213 Frauen) 5 Therapiegruppen und einer Kontrollgruppe zugeteilt. Der Mineralstatus des Knochens und der therapeutische Effekt wurden mittels vor LTX und danach halbjährlich erfolgten Knochendichtemessungen (Dual Energy X-ray Absorptiometry - DEXA) an der Lendenwirbelsäule (LWS) sowie am Schenkelhals (SH) bewertet. Patienten mit primärer biliärer Zirrhose, primär sklerosierender Cholangitis und autoimmuner Zirrhose weisen präoperativ und innerhalb der ersten 6 postoperativen Monate den niedrigsten Knochenmineralbestand auf. Den Sexualhormonstatus betrachtend wiesen 17,5% aller gemessenen Testosteronserumspiegel bei Männern und 78,3% aller gemessenen Serumöstrogenspiegel bei postmenopausalen Frauen hypogonadische Werte auf. Jedoch waren die Serumtestosteronkonzentrationen bei Männern und die Serumöstrogenkonzentrationen bei postmenopausalen Frauen zwischen den mit Calcitriol therapierten Patienten und nichttherapierten Patienten (Kontrollgruppe) nicht signifikant verschieden. Die Basisimmunsuppression bestand aus Cyclosporin A und Tacrolimus kombiniert mit Prednisolon. Bei Patienten, die Tacrolimus erhielten war der Knochenverlust an der LWS signifikant geringer (p=0,0249). Diese Beobachtung wurde höchstwahrscheinlich durch deutlich erhöhte Prednisolongaben bei Patienten mit Cyclosporin A bedingt. Mit Calcitriol therapierte Patienten erhielten wesentlich mehr Prednisolon bezogen auf die kumulative Menge und den Zeitraum im Vergleich zur nichttherapierten Kontrollgruppe. Während die niedrige Dosierung von 0,25 mg zusätzlich Kalzium benötigte um bessere Resultate am SH zu erzielen, führte die Dosierung von 0,5 µg zu einem Knochendichtezuwachs von 10,17% an der LWS und 5,9% am SH ohne Kalziumzusatz und zu einem Knochendichtezuwachs von 10,0% an der LWS und 5,2% am SH mit Kalziumgabe in einem durschnittlichen Therapiezeitraum von 1,5 Jahren. Die Dreifachkombination aus 0,5 µg Calcitriol, 1000 mg Ca und 25 mg Natriumfluorid zeigte bei Patienten mit schwerwiegender Osteoporose die besten Resultate an der LWS (Zuwachsrate 10,67%) und am SH (Zuwachsrate 12,97%) nach 1,15 Jahren. Bei nichttherapierten Patienten der Kontrollgruppe wurde ein Spontanzuwachs der Knochendichte an der LWS von 2,25% und ein Knochendichteabfall am SH von 0,86% beobachtet. Die Rate atraumatischer Frakturen konnte mit 1,77% gering gehalten werden. Calcitriol ist ein wirkungsvolles, nebenwirkungsarmes Therapeutikum zum Ausgleich und zur Prävention des Knochenmasseverlustes bei Patienten mit Lebertransplantation. Natriumfluorid steigert den Mineralisationseffekt besonders am Schenkelhals. / Secondary osteoporosis is a frequent complication of endstage liver disease which often detoriates after orthotopic liver transplantation (OLT). Management and therapy of osteopenic bone disease are still a major problem in liver transplant recipients. First purpose of this study was to estimate the magnitude of various specific liver diseases, sexual hormones and immunosuppression on bone loss in patients undergoing OLT. The second aim was to evaluate the effect of calcitriol (1,25(OH)2D3) in comparatively low dosages of 0,25 µg and 0,5 µg as a single therapy or in combination with 1000 mg calcium (Ca) in light and moderate osteoporosis. Patients with severe osteoporosis received a triple combination with 0,5 µg calcitriol, 1000 mg Ca and 25 mg sodium fluoride. Out of 860 patients undergoing OLT from 1988 to 1996, 509 (256 males, 213 females) were assigned to 5 treatment groups as well as to a control group. Bone mineral status and the effect of therapy were estimated by bone mineral density (BMD) measurements with dual energy X-ray absorptiometry of lumbar spine (LS) and femoral neck (FN) before and every six month after OLT. Primary biliary cirrhosis, primary sclerosing cholangitis and autoimmune cirrhosis were associated with a low pre-existing bone mineralisation and most severe decrease of bone mass during the early post-transplantation period. Considering hormonal measuring performed during the study period 17,5% of all measured testosterone levels in men and 78,3% of all measured oestrogen levels in postmenopausal women were in hypogonadic range. Testosterone and oestrogen levels were not significant different among with calcitriol treated and non-treated patients. Baseline immunosuppression consisted of cyclosprin A or tacrolimus initially combined with corticosteroids. Patients treated with tacrolimus had significant less bone mass reduction in the lumbar spine than patients treated with cyclosporine (p=0,0249). This observation was certainly caused by less application of prednisolone. With calcitriol treated patients received considerably more prednisolone and over a longer period of time than non-treated controls. Bone mineralisation essentially increased under calcitriol therapy in all treatment groups. Whereas the low dose of 0,25 µg needed a complementation of Ca especially to achieve better results in the FN, the dosage of 0,5 µg led to BMD improvement of 10,17% in LS and 5,9% in FN without Ca and to an improvement of 10,0 % in LS and 5,2% in FN with Ca supplementation in an average period of 1,5 years. The triple combination with 0,5 µg calcitriol, 1000 mg Ca and 25 mg sodium fluoride which was used in cases of severe osteoporosis showed the best results with a BMD augmentation rate of 10,67% in LS and 12,79% in FN after a period of 1,15 years. In the untreated controls we only found spontaneous BMD improvement of 2,25% in LS and a further bone loss of 0,86% in FN. A small fracture rate of 1,77% was observed. Calcitriol therapy effectively prevents posttransplant bone loss and augments bone mineralisation in osteoporotic patients. Moreover it minimizes the incidence of atraumatic fractures. Additional sodium fluoride increases the bone density in LS and has a special effect on FN. Side effects are negligible.
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Avaliação do consumo alimentar e da densidade mineral óssea de crianças com dermatite atópica / Food consumption and bone mineral density evaluation of children with atopic dermatitis

Penterich, Vanessa Ramos Alves 01 September 2011 (has links)
A dermatite atópica é uma doença de pele de caráter inflamatório crônico que normalmente precisa de tratamento com glicocorticóide tópico. O objetivo deste estudo foi avaliar o impacto da Dermatite atópica no consumo de nutrientes, no estado nutricional e no metabolismo ósseo de crianças com dermatite atópica moderada e grave comparadas à crianças saudáveis. Foram incluídas neste estudo 60 crianças de 4 a 12 anos com AD moderada/grave e 54 controles. O consumo alimentar foi avaliado por três recordatórios de 24 horas. O estado nutricional foi determinado pelo z-escore de altura para idade, peso por idade e do índice de massa corporal. Os marcadores ósseos séricos foram 25OH vitamina D, fosfatase alcalina óssea, cálcio sérico, fósforo, PTH, osteocalcina, CTX e cortisol. Os pacientes e familiares foram questionados quanto à fraturas, exposição solar e escore de atividade física. Por meio de densitometria dupla de Raio-X avaliou-se o conteúdo mineral ósseo (CMO), a densidade mineral óssea (DMO) e o z-score da coluna lombar, do fêmur total e do corpo inteiro. As crianças com dermatite atópica usavam glicocorticóide tópico em média por 3,9 ±1,81 anos. O tempo de exposição solar foi menor nas crianças com dermatite atópica. O consumo alimentar evidenciou um alto consumo de proteínas em ambos os grupos, e a ingestão de gordura foi mais baixo na crianças com DA. A média consumida de cálcio e vitamina D foi abaixo da recomendação nutricional em ambos os grupos. As crianças com DA apresentaram mais casos de rinite, asma e alergia alimentar do que o grupo controle. Segundo o zscore de altura para idade as crianças com DA foi significativamente mais baixas quando comparadas com o grupo controle. O CTX sérico foi menor no grupo DA. O CMO da coluna lombar foi mais baixo nas crianças com DA, e o CMO, a DMO e o z-score do fêmur total também foram significativamente menores no grupo DA do que no grupo controle. Neste grupo de crianças com DA, estudado o uso do glicocorticóide tópico pode ter diminuído a altura para idade, e a massa óssea. / Atopic dermatitis is an inflammatory allergic skin disease that often requires glicocorticosteroids therapy. The aim of this study was to determine the atopic dermatitis impact on food ingestion, nutritional status and bone mass in children with moderate to severe AD compared with a control group. Food ingestion was evaluated with 3 days 24-hour food recordathory. Nutritional status was determined with height to age z-score, weight for age z-score and BMI z-score. Bone markers measured in serum were 25OH vitamin D, bone phosphatase alkaline, CTX, serum calcium, phosphorus, osteocalcin, PTH and cortisol. Information on lifestyle parameters, bone fractures, sun exposure and physical activity were collected by use of a standardized questionnaire. Lumbar spine, total femur and whole body, bone mineral content (BMC), bone mineral density (BMD) and z-score was measured by dual-energy X-ray absorptiometry in 60 children (age 4-12years) with moderate to severe AD and 54 health controls, with the same age. In children, low BMD was defined as a Z-score less than -2. The AD children used topic glicocorticosteroids for a mean of 3,9 ±1,81 years. The sun exposure was lower in the AD group. Food ingestion showed high protein ingestion levels in both groups, and the fat consumption was lower in the AD children. The calcium and vitamin ingestion were bellow the recommendations in the two groups. Children with AD had more riniths, asthma and food allergy then control group. The CTX was lower in the AD group. The children with AD were significantly smaller according to the height for age zscore. There was significant smaller BMC on lumbar spine, and in the BMC, BMD and z-score in the total femur on the AD children. Low BMD occured more frequently in this population of children with moderate to severe AD compared with the control group. Use of topical glicocorticosteroids in the previous could be 5 years associated with the decrease in BMD.

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