Η οστεοπόρωση αποτελεί την πιο συχνή μεταβολική διαταραχή των οστών που οδηγεί σε αυξημένη ευθραυστότητα αυτών και κατά συνέπεια σε χαμηλής ενέργειας κατάγματα. Τα συνηθέστερα οστεοπορωτικά κατάγματα συμβαίνουν στην περιοχή της πηχεοκαρπικής άρθρωσης, στους σπονδύλους καθώς και στο ισχίο, οστά δηλαδή στα οποία η αναλογία σπογγώδους και φλοιώδους οστού είναι συγκεκριμένη. Λόγω του μεγέθους του προβλήματος, υπάρχει μεγάλο ενδιαφέρον για την εκτίμηση της οστεοπόρωσης και κατ’ επέκταση τη πρόβλεψη του κινδύνου κατάγματος. Μια σειρά από διαφορετικές τεχνικές έχουν αναπτυχθεί για τη μέτρηση διαφόρων σκελετικών περιοχών ως μέσο για την εκτίμηση του κινδύνου κατάγματος. Η απορροφησιομετρία ακτίνων-Χ διπλής ενέργειας (DXA) είναι η τεχνική που χρησιμοποιείται πιο συχνά για την διάγνωση της οστεοπόρωσης μέσω της εκτίμησης της οστικής πυκνότητας BMD. Ωστόσο, στην πραγματικότητα, μόνο το 60% της διακύμανσης της οστικής αντοχής μπορεί να εξηγηθεί από τις διακυμάνσεις της επιφανειακής οστικής πυκνότητας. Στη συγκεκριμένη μελέτη σταθήκαμε κυρίως στην απορροφησιομετρία ακτίνων-Χ διπλής ενέργειας, στην περιφερική ποσοτική υπολογιστική τομογραφία (pQCT) και στην απεικόνιση μαγνητικού συντονισμού (MRI). Κλινικές και πειραματικές μελέτες έχουν δείξει ότι η απεικόνιση μαγνητικού συντονισμού έχει το δυναμικό να είναι μια χρήσιμη μέθοδος για την μελέτη του σπογγώδους οστού. Το τεχνικό υπόβαθρο αυτής της μεθόδου μπορεί να εξηγηθεί από τις διαφορές της μαγνητικής επιδεκτικότητας στην διεπιφάνεια μεταξύ του σπογγώδους οστού και του μυελού των οστών, που οδηγούν σε χωρικές ανομοιογένειες του μαγνητικού πεδίου. Αυτές οι ανομοιογένειες έχουν ως αποτέλεσμα την εκτροπή της συμφασικότητας της εγκάρσιας μαγνήτισης. Αυτό οδηγεί στην μεταβολή της τιμής του Τ2* του μυελού του οστού. Η μεταβολή του Τ2* μαζί με τα χαρακτηριστικά αυτού του χρόνου χαλάρωσης παρέχουν πληροφορίες για την πυκνότητα και την δομή του περιβάλλοντος σπογγώδους οστικού πλέγματος (ms). Οι κύριοι στόχοι της παρούσας μελέτης ήταν: α) Ο προσδιορισμός της ικανότητας των μετρήσεων του ενεργού εγκάρσιου χρόνου χαλάρωσης Τ2* να επιτύχει διάκριση μεταξύ γυναικών με φυσιολογική ή οστεοπορωτική αρχιτεκτονική του σπογγώδους οστού. β) Η συσχέτιση του εγκάρσιου χρόνου χαλάρωσης Τ2* με τους δείκτες aBMD, vBMD και Trabecular Density που λαμβάνεται μέσω των εξετάσεων DXA και pQCT αντίστοιχα. γ) Η εκτίμηση της ακρίβειας των μετρήσεων του Τ2* μαγνητικού συντονισμού σε συγκεκριμένα τμήματα του ανθρώπινου σώματος με πρωτεύοντα στόχο την περιοχή της οσφυϊκής μοίρας και της κνήμης. Μετά από τη σχετική έγκριση των Επιτροπών Βιοηθικής και Έρευνας του Π.Γ.Ν. «Αττικόν» και του Γ.Ν.Α. «ΚΑΤ», στη μελέτη μας συμμετείχαν 15 μετεμμηνοπαυσιακές γυναίκες και 5 υγιείς, οι οποίες αποτέλεσαν την ομάδα ελέγχου. Όλες οι συμμετέχοντες πραγματοποίησαν τις εξετάσεις των pQCT κνήμης και οστικής πυκνότητας ΟΜΣΣ, στα ίδια συστήματα pQCT και DXA του Γ.Ν.Α. «ΚΑΤ». Έπειτα, για την διεξαγωγή της μαγνητικής τομογραφίας ΟΜΣΣ-κνήμης, οι 15 μετεμμηνοπαυσιακές γυναίκες χωρίστηκαν σε δυο ομάδες. Η Α ομάδα αποτελούμενη από 9 μετεμμηνοπαυσιακές γυναίκες, πραγματοποίησε την μαγνητική τομογραφία στον μαγνητικό τομογράφο του Ευγενίδειου Θεραπευτηρίου και αντίστοιχα, η Β ομάδα αποτελούμενη από 6 μετεμμηνοπαυσιακές γυναίκες πραγματοποίησε την μαγνητική τομογραφία στον μαγνητικό τομογράφο του Π.Γ.Ν. «Αττικόν». Η ομάδα των 5 υγιών ατόμων, πραγματοποίησε την εξέταση και στα δυο συστήματα μαγνητικής τομογραφίας, ώστε να διερευνηθεί το κατά πόσον η ένταση του μαγνητικού πεδίου επηρεάζει τις παραμέτρους που επρόκειτο να υπολογιστούν. Για τον υπολογισμό της οστικής πυκνότητας της οσφυϊκής μοίρας, ελήφθησαν προσθοπίσθιες προβολές της ΟΜΣΣ και πιο συγκεκριμένα των οσφυϊκών σπονδύλων Ο1 – Ο4 και υπολογίστηκε τόσο η μέση τιμή BMD των Ο1 – Ο4, όσο και η τιμή BMD κάθε σπονδύλου ξεχωριστά. Επιπρόσθετα, σε κάθε ασθενή ελήφθησαν υπόψη τα στοιχεία που προκύπτουν από την μελέτη της τομής 4% του μήκους της κνήμης από την κάτω αρθρική επιφάνεια. Η τομή 4% παρέχει πληροφορίες για το σπογγώδες οστό και οι προτεινόμενες παράμετροι που συλλέχθηκαν ήταν η ογκομετρική πυκνότητα του σπογγώδους οστού (trabecular density) και η ολική πυκνότητα οστού (total density, vBMD). Στην απεικόνιση μαγνητικού συντονισμού, ελήφθησαν ακολουθίες πολλαπλών αντηχήσεων (multi echo) και πολλαπλών τομών (multi slice) για την μέτρηση του εγκάρσιου χρόνου χαλάρωσης T2* χωρίς καταστολή λίπους σε εγκάρσιο και στεφανιαίο επίπεδο. Εν συνεχεία, για την εκτίμηση του εγκάρσιου χρόνου χαλάρωσης T2 ελήφθησαν ανατομικές ακολουθίες Τ2 προσανατολισμού χωρίς καταστολή λίπους σε εγκάρσιο και στεφανιαίο επίπεδο. Στην κεντρική τομή που αντιστοιχεί στο 4% του μήκους της κνήμης από την κάτω αρθρική επιφάνεια καθώς και στις κεντρικές τομές των οσφυϊκών σπονδύλων Ο1 – Ο4, σχεδιάστηκαν οι περιοχές ενδιαφέροντος (ROI) σε όλες τις εικόνες διαφορετικών ΤΕ. Εν συνεχεία, με τη χρήση του λογισμικού IDL πραγματοποιήθηκε αλγόριθμος ανάλυσης Levenberg – Marquadt με τον οποίον έγινε ο υπολογισμός των χρόνων Τ2* και Τ2. Τα αποτελέσματα στην παρούσα μελέτη δείχνουν μια σημαντική θετική συσχέτιση των παραμέτρων οστικής πυκνότητας των περιοχών της ΟΜΣΣ και της κνήμης μεταξύ τους, (r= 0.76 – 0.86, p<0.05). Επιπρόσθετα, έγινε συσχέτιση όλων των παραμέτρων της οστικής πυκνότητας με την ηλικία των εξεταζόμενων γυναικών, όπου σημειώθηκαν ικανοποιητικές αρνητικές συσχετίσεις, (r= -0.66 - -0.73, p<0.05). Ακόμα, σημειώθηκε ικανοποιητική θετική συσχέτιση του εγκάρσιου χρόνου χαλάρωσης T2*, ιδιαίτερα για την περιοχή της κνήμης, με την ηλικία των εξεταζόμενων γυναικών (r= 0.59 – 0.67, p<0.05). Για το σύστημα των 3Τ, ο χρόνος Τ2* στην περιοχή της οσφυϊκής μοίρας ήταν μικρότερος στην ομάδα ελέγχου (4,9 ± 0,4 ms) σε σχέση με την ομάδα Β των μετεμμηνοπαυσιακών γυναικών (5,5 ± 0,8 ms). Για τους χρόνους Τ2, η διαφοροποίηση φάνηκε να είναι πιο ξεκάθαρη, καθώς για την ομάδα ελέγχου, ο χρόνος Τ2 ήταν 65,7 ± 2,4 ms, ενώ για την ομάδα Β 84,7 ± 2,7 ms. Για τις μετρήσεις στην περιοχή της κνήμης, οι χρόνοι Τ2* που καταγράφηκαν ήταν 7,8 ± 0,6 ms για την ομάδα ελέγχου και 9,4 ± 0,4 ms για την ομάδα Β και την mFFE ακολουθία. Αντίστοιχα για την shortest ακολουθία οι χρόνοι χαλάρωσης ήταν 9,0 ± 0,5 ms και 10,8 ± 0,4 ms. Ωστόσο, η διαφορά στους χρόνους Τ2 των δυο ομάδων δεν επέτρεψε τον ασφαλή διαχωρισμό τους, με κριτήριο τον χρόνο αυτό. Για το σύστημα του 1.5 Τ, ο χρόνος Τ2* στην περιοχή της οσφυϊκής μοίρας ήταν μικρότερος στην ομάδα ελέγχου (14,0 ± 1,5 ms) σε σχέση με την ομάδα Γ των μετεμμηνοπαυσιακών γυναικών (20,4 ± 1,2 ms). Αντιθέτως, τα αποτελέσματα των χρόνων Τ2, δεν προσέφεραν κάποιο ξεκάθαρο συμπέρασμα. Αναφορικά με τις μετρήσεις της κνήμης, παρατηρήθηκαν ικανοποιητικές διαφορές μεταξύ των χρόνων Τ2* των δυο ομάδων και για τις δυο ακολουθίες (mFFE και mFFE shortest). Οι χρόνοι που σημειώθηκαν ήταν 16,7 ± 1,2 ms για την ομάδα ελέγχου και 20,9 ± 1,7 ms για την ομάδα Γ και την mFFE ακολουθία. Αντίστοιχα, για την shortest ακολουθία οι χρόνοι χαλάρωσης ήταν 16,5 ± 1,2 ms και 20,6 ± 1,6 ms. Επίσης, η διαφορά των χρόνων Τ2 των δυο ομάδων ήταν ικανοποιητική, (91,6 ± 2,4 ms για την ομάδα Α και 99,0 ± 2,8 ms για την ομάδα Γ). Συμπερασματικά, η παρούσα μελέτη απέδειξε πως μέσω του φαινομένου της αποκατάστασης μαγνητικού συντονισμού και κατ’ επέκταση της μέτρησης των εγκάρσιων χρόνων αποκατάστασης (χαλάρωσης) T2* και T2, μπορούν να εκτιμηθούν μεταβολές της κατάστασης των οστών που σχετίζονται με την ηλικία και την οστική πυκνότητα, μεταξύ υγιών και μετεμμηνοπαυσιακών γυναικών. / Osteoporosis is the most common metabolic bone disorder leading to increased fragility and consequently to low energy fractures. The most common osteoporotic fractures occur in the wrist joint, the vertebrae and the hip, i.e. bones in which the ratio of trabecular and cortical bone is specific. Because of the problem magnitude, there is great interest in assessing osteoporosis and hence the prediction of the fracture risk. A number of different techniques have been developed to measure different skeletal sites as a tool for assessing the fracture risk. The dual energy X-ray absorptiometry (DXA) is the most frequently used technique for the diagnosis of osteoporosis by evaluating the bone mineral density BMD. However, in reality, only 60% of the variation in bone strength can be explained by variations in areal bone density. In this study, we mainly stood in dual energy X-ray absorptiometry, peripheral quantitative computed tomography (pQCT) and magnetic resonance imaging (MRI). Clinical and experimental studies have shown that magnetic resonance imaging has the potential to be a useful method for the study of trabecular bone. The technical background of this method can be explained by the differences in the magnetic susceptibilities between the inter-surfaces of trabecular bone and bone marrow, leading to spatial inhomogeneities of the magnetic field. These inhomogeneities result in additional dephasing of transverse magnetization. The change in Τ2* together with the characteristics of this relaxation time, provide information on the density and structure of trabecular bone matrix (ms). The main objectives of this study were: a) To determine the ability of the active transverse relaxation time Τ2* measurements, to achieve discrimination between women with normal or osteoporotic trabecular bone architecture. b) The correlation of the transverse relaxation time Τ2* with aBMD, vBMD and Trabecular Density indicators, obtained through DXA and pQCT examinations, respectively. c) The assessment of Τ2* magnetic resonance measurements accuracy in certain parts of the human body, with primary target the area of lumbar spine and tibia. After the approval of Ethics and Research Committees of Attikon University Hospital and K.A.T. General Hospital, 15 postmenopausal women and 5 healthy, which formed the control group, participated in our study. All the participants performed the pQCT tibia and lumbar spine bone mineral density examinations, at the same pQCT and DXA systems of K.A.T. General Hospital. Then, for the magnetic resonance imaging examination conduct of lumbar spine – tibia, the 15 postmenopausal women were divided into two groups. The group A, consisting of 9 postmenopausal women, conducted the MRI examinations at the MRI scanner of Eugenedion Hospital and respectively, the group B, consisting of 6 postmenopausal women performed the MRI scans at the MRI scanner of Attikon University Hospital. The group of the 5 healthy subjects performed the examination in both magnetic resonance imaging scanners in order to investigate whether the magnetic field affects the parameters that were to be calculated. To calculate the BMD of the lumbar spine, anteroposterior views of the lumbar spine and more specifically of the lumbar vertebrae L1 - L4 were obtained. The mean BMD of L1 - L4 and the BMD for each vertebra separately, were calculated. Additionally, for each patient, the data resulting from the study of the section 4% of the tibia length from the lower articular surface were taken into account. The section 4% provides information on the trabecular bone and the proposed parameters which were collected were the volumetric density of the trabecular bone (trabecular density) and the total bone density (total density, vBMD). In magnetic resonance imaging, multiple echoes (multi echo) and multiple slices (multi slice) sequences were received for measuring the transverse relaxation time Τ2*, without fat suppression in transverse and coronal plane. Thereafter, for assessing the transverse relaxation time Τ2, Τ2 - weighted anatomical sequences were received, without fat suppression in transverse and coronal plane. In the central section corresponding to 4% of the tibia length from the lower articular surface and in the central sections of lumbar vertebrae L1 - L4, were designed regions of interest (ROI) in all different TE images. Then, using the IDL software, Levenberg - Marquadt analysis algorithm was held, in which Τ2* and Τ2 times were calculated. The results in this study show a significant positive correlation between the parameters of lumbar spine and tibia bone density, (r = 0.76 - 0.86, p <0.05). Additionally, there was correlation of all parameters of bone mineral density with the age of the examined women, where there were sufficient negative correlations, (r = -0.66 - -0.73, p <0.05). Still, there has been good correlation between the transverse relaxation time Τ2*, especially for the region of the tibia, with the age of the examined women (r = 0.59 - 0.67, p <0.05). For the system of 3T, the Τ2* time, in the lumbar spine, was lower in the control group (4,9 ± 0,4 ms) compared to the group B of postmenopausal women (5,5 ± 0,8 ms). For the Τ2 time, the differentiation seemed to be clearer, as for the control group, the Τ2 was 65,7 ± 2,4 ms, while for group B 84,7 ± 2,7 ms. For the tibia measurements, Τ2* times which were recorded, were 7,8 ± 0,6 ms for the control group and 9,4 ± 0,4 ms for group B and the mFFE sequence. Respectively, for the shortest sequence, relaxation times were 9,0 ± 0,5 ms and 10,8 ± 0,4 ms. However, the Τ2 time difference for the two groups, did not allow safe separation, based on this time. For the system of 1.5 T, the Τ2* time, in the lumbar spine, was lower in the control group (14,0 ± 1,5 ms) compared to the group C of postmenopausal women (20,4 ± 1,2 ms). In contrast, the Τ2 time results, did not offer a clear conclusion. Regarding the tibia measurements, there were seen satisfactory differences between the Τ2* times of the two groups, for both sequences (mFFE and mFFE shortest). The recorded times were 16,7 ± 1,2 ms for the control group and 20,9 ± 1,7 ms for group C, for the mFFE sequence. Respectively, for the shortest sequence the relaxation times was 16,5 ± 1,2 ms and 20,6 ± 1,6 ms. Also, the Τ2 time difference between the two groups was satisfactory, (91,6 ± 2,4 ms for group A and 99,0 ± 2,8 ms for group C). In conclusion, this study demonstrated that, through the phenomenon of magnetic resonance recovery and hence the measurement of the transverse recovery (relaxation) times Τ2* and Τ2, can assess changes in bone status related to age and bone mineral density, between healthy and postmenopausal women.

Thesis (MNutr (Interdisciplinary Health Sciences. Human Nutrition))--University of Stellenbosch, 2006. / INTRODUCTION: Postmenopausal osteoporosis is associated with significant morbidity, mortality, reduction in quality of life, and increasing health care costs OBJECTIVE: The study objective was to identify the risk factors associated with the occurrence of osteoporosis, in Kenyan Asian women seen at the Aga Khan University Hospital, Nairobi, Kenya since there is no literature on the prevalence of all these risk factors for osteoporosis in a similar middle aged population sample of Kenyan Asian women. METHOD: The study was of a retrospective design and used recall as a basis of data collection. A socio-demographic questionnaire was completed and anthropometric measurements, of height, weight, waist and hip circumference taken. Bone mineral density (BMD) had been measured previously using Quantitative Computed Tomography (QCT) at the lumbar spine, T11 to L4. Nutrient intake was assessed using a validated food frequency questionnaire (FFQ) and physical activity was determined using the Epic Physical Activity Questionnaire 2 (EPAQ2). BMD scans had been done on all study participants from January 2004 to December 2004 and the subjects were aware of their bone status. RESULTS: Risk factors that were identified by being associated with the development of osteoporosis in Asian women were age (p<0.001), waist size (p<0.001), hip size (p<0.001) and BMI (p<0.001), low physical activity (p=0.001) and use of prescription drugs. Seventy two percent of the study sample was using prescription drugs and the effect on bone mass was most likely detrimental. Anti-hypertensive (p=0.002), non steroidal anti inflammatory drugs (p=0.003) and anti-diabetic drugs (p=0.033) had a significant negative association with bone health. Energy, protein, fat and carbohydrate intake in all the groups was above the EAR and comparatively similar. The intake of all the micronutrients in the study group was above the DRI. There were no statistical significant differences in most of the trace element intake between the two groups, apart from iodine, biotin and manganese. No dietary risk factors were identified which impacted adversely on bone health in this group. The impact of gynaecologic history (parity, oral contraceptive use, age of menarche) on BMD was uncertain. The educational level of the study sample was high as 50% of the subjects were graduates and had a relatively better diet. CONCLUSION: As Kenyan Asian women age they experience the menopausal transition and the risk of developing osteoporosis increases. No nutritional factors were identified that were adversely associated with BMD. Low level of physical activity, prescription drugs for chronic diseases like hypertension, asthma, diabetes and arthritis, age, weight and body mass index were identified and found to be adversely associated with bone mineral density. Early detection, and implementation of patient education, physical activity, and a diet rich in all nutrients, will help to slow down the progression of osteoporosis.

Made available in DSpace on 2014-06-11T19:23:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-03-01Bitstream added on 2014-06-13T19:29:41Z : No. of bitstreams: 1 bedani_r_me_arafcf.pdf: 2338678 bytes, checksum: 9af8eea43bfcf2787afc52a69327fd28 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / A osteoporose é uma doença crônica que afeta principalmente mulheres na pós-menopausa, e caracteriza-se por perda de massa óssea e deterioração da arquitetura do tecido ósseo, sendo considerada como um sério problema de saúde pública. A Terapia de Reposição Hormonal (TRH) é talvez o tratamento mais efetivo para reduzir a perda óssea, no entanto vem acompanhada por efeitos adversos como o aumento do risco de câncer de mama e de endométrio. Terapias alternativas, como a ingestão de isoflavonas, vêm sendo propostas a fim de se prevenir a osteoporose. As isoflavonas, um tipo de fitoestrógeno, parecem desenvolver atividade biológica parecida com a dos estrógenos de mamíferos, pois apresentam habilidade para se ligarem aos receptores estrogênicos. Além disso, estudos em animais e em humanos têm mostrado que as isoflavonas vêm se constituindo numa alternativa interessante para o controle do metabolismo lipídico e da obesidade. Além das isoflavonas, uma das possíveis maneiras de se prevenir a perda óssea é por meio da ingestão de quantidades adequadas de cálcio, um dos componentes dietéticos de maior importância para a manutenção da integridade óssea. Desta forma, o objetivo deste trabalho foi estudar o efeito da ingestão do iogurte de soja, fermentado com Enterococcus faecium e Lactobacillus jugurti, suplementado com isoflavonas e cálcio sobre o peso corpóreo e tecido ósseo de ratas maduras ovariectomizadas. Os animais foram divididos em 5 grupos, cada qual com 9 animais: pseudo-ovariectomizado, ovariectomizado; ovariectomizado que ingeriu o produto fermentado suplementado com isoflavonas e cálcio, ovariectomizado que ingeriu o produto fermentado suplementado com cálcio e ovariectomizado que ingeriu placebo suplementado com cálcio. O tratamento durou 3 meses e foram utilizados tíbias e fêmures de cada animal para... . / Osteoporosis is a chronic disease that affects mainly postmenopausal women, and it is characterized by bone loss and deterioration of the bone tissue architecture, and it considered a serious problem of public health. The Hormonal Replacement Therapy Hormonal (HRT) is the most effective treatment to reduce the bone loss, however it may be associated with adverse effects as the increase of the risk of endometrium and breast cancer. Alternative therapies, as intake of isoflavones, have being proposed to prevent the osteoporosis. Isoflavones, a type of phytoestrogens, seem to have biological activity like the mammals estrogens, because they present ability to bind to the estrogens receptors. Moreover, studies in animals and in human have shown that isoflavones may be an interesting alternative for the control of the lipidic metabolism and the obesity. On the other hand, the intake of adequate amounts of calcium, one of the dietary components of bigger importance for the maintenance of the bone integrity, is also considerate to be able to prevent the bone loss. Then, the objective of this research was to study the effect of the intake of the soy yoghurt, fermented with Enterococcus faecium and Lactobacillus jugurti, supplemented with isoflavones and calcium on the corporal weight and bone tissue of ovariectomized mature rats. The animals had been divided in 5 groups, each one with 9 animals: sham-ovariectomized, ovariectomized; ovariectomized treated with soy yoghurt supplemented with isoflavones and calcium, ovariectomized treated with soy yoghurt supplemented with calcium and ovariectomized treated with placebo supplemented with calcium. The treatment lasted 3 months and the tibia and femur of each animal were used for following analysis: bone length; mechanical assay of three points; weight, volume and bone density; bone mineral content; bone... (Complete abstract, click electronic address below).

abstract: Skeletal diseases related to reduced bone strength, like osteoporosis, vary in frequency and severity among human populations due in part to underlying genetic differentiation. With >600 disease-associated mutations (DAMs), COL1a1, which encodes the primary subunit of type I collagen, the main structural protein in bone, is most commonly associated with this phenotypic variation. Although numerous studies have explored genotype-phenotype relationships with COL1a1, surprisingly, no study has undertaken an evolutionary approach to determine how changes in constraint over time can be modeled to help predict bone-related disease factors. Here, molecular population and comparative species genetic analyses were conducted to characterize the evolutionary history of COL1a1. First, nucleotide and protein sequences of COL1a1 in 14 taxa representing ~450 million years of vertebrate evolution were used to investigate constraint across gene regions. Protein residues of historically high conservation are significantly correlated with disease severity today, providing a highly accurate model for disease prediction, yet interestingly, intron composition also exhibits high conservation suggesting strong historical purifying selection. Second, a human population genetic analysis of 192 COL1a1 nucleotide sequences representing 10 ethnically and geographically diverse samples was conducted. This random sample of the population shows surprisingly high numbers of amino acid polymorphisms (albeit rare in frequency), suggesting that not all protein variants today are highly deleterious. Further, an unusual haplotype structure was identified across populations, but which is only associated with noncoding variation in the 5' region of COL1a1 where gene expression alteration is most likely. Finally, a population genetic analysis of 40 chimpanzee COL1a1 sequences shows no amino acid polymorphism, yet does reveal an unusual haplotype structure with significantly extended linkage disequilibrium >30 kilobases away, as well as a surprisingly common exon duplication that is generally highly deleterious in humans. Altogether, these analyses indicate a history of temporally and spatially varying purifying selection on not only coding, but noncoding COL1a1 regions that is also reflected in population differentiation. In contrast to clinical studies, this approach reveals potentially functional variation, which in future analyses could explain the observed bone strength variation not only seen within humans, but other closely related primates. / Dissertation/Thesis / Ph.D. Biology 2010

Objetivos La calidad de vida en pacientes VIH positivo puede verse afectada por enfermedades como la osteoporosis u osteopenia. Múltiples estudios han investigado las causas de la disminución de densidad mineral ósea en esta población. El objetivo fue realizar una revisión sistemática y meta análisis para determinar la asociación entre el uso de TARGA (Tratamiento Antirretroviral de Gran Actividad) y la baja densidad mineral ósea en pacientes infectados. Métodos Se realizó una búsqueda en diversas bases de datos para identificar estudios transversales, casos y controles, cohortes y ensayos clínicos aleatorizados. Dos investigadores independientemente revisaron las bases de datos y un tercero intervino en caso de discrepancias. Se identificaron ocho estudios transversales y una cohorte que reportan la asociación entre la densidad mineral ósea en pacientes con VIH en TARGA versus paciente con VIH sin tratamiento. Resultados Ocho estudios transversales y una cohorte que reportan la asociación entre baja densidad mineral ósea y VIH en pacientes tratados versus pacientes sin tratamiento fueron obtenidos; la mayoría de baja calidad. Se realizó un meta análisis y los siguientes resultados fueron obtenidos. Los odds de osteopenia y osteoporosis en pacientes con VIH recibiendo TARGA versus pacientes sin tratamiento fue OR 1.03 CI 95%: 0.69-1.55; I2: 17% y OR 1.27 CI 95%: 0.67-2.38; I2: 5% respectivamente. Conclusión Nuestros resultados muestran que la evidencia no es suficientemente fuerte para determinar si el TARGA tiene un efecto verdadero sobre la DMO. Los resultados no fueron estadísticamente significativos, sin embargo la baja calidad de los estudios puede alterar las conclusiones. Se requirieren mayores estudios como cohortes con seguimiento a largo plazo y ajustados a datos antropométricos y propios de la enfermedad. / Objectives Quality of life in HIV positive patients can be deteriorated by diseases like osteoporosis or osteopenia. Multiple studies have investigated the causes of reduced bone mineral density in HIV patients. The objective of our study was to perform a systematic review and meta-analysis to determine the association between the use of HAART (Highly Active Antiretroviral Therapy) and low bone mass density in HIV infected patients. Methods We searched several data bases to identify cross sectional, case controls, cohorts and randomized clinical trials. Two independent researchers reviewed the databases and a third investigator was involved in case of discrepancies. We identified eight cross-sectional studies and one cohort that reported the association between bone mineral density in patients with HIV in HAART versus patients with HIV naive treatment. Results Eight cross sectional studies and one cohort reporting the association between low bone mass density in HIV treated patients versus non-treated were retrieved; the majority with low quality. A meta-analysis was performed and the following results were obtained. The odds of osteopenia and osteoporosis in HIV-infected patients receiving HAART compared with naïve patients was OR 1.03 CI 95%: 0.69-1.55; I2: 17% and OR 1.27 CI 95%: 0.67-2.38; I2: 5% respectively. Conclusion Our results show that evidence is not strong enough to determine that HAART has an effect on BMD. Statistical significance was not found, nevertheless low quality studies jeopardize the conclusions. Further research is needed with larger cohorts with longer follow-up and adjusted to anthropometric and infection related data. / Tesis

No description available.

O presente estudo teve como objetivo verificar se a radiografia periapical é capaz de identificar pacientes com baixa massa óssea, combinando a análise morfológica do trabeculado ósseo e a densidade radiográfica a parâmetros clínicos. A amostra foi constituída por 60 mulheres na faixa etária acima de 40 anos e em período pós-menopausa que foram encaminhadas ao Serviço de Radiologia da Faculdade de Odontologia da UFRGS durante o ano de 2006, com indicação de radiografia periapical da região de pré-molares e/ou molares inferiores e que realizaram, no mesmo período, um exame de densitometria óssea pela técnica de absorciometria por raios X de emissão dual (DXA) nas regiões de coluna lombar e fêmur proximal. Com base nos resultados da densitometria, as pacientes foram divididas em dois grupos (normal e com perda óssea) e para cada radiografia foram obtidos os valores de densidade radiográfica e 14 variáveis morfológicas do trabeculado. As variáveis clínicas utilizadas foram idade e IMC. A análise estatística por árvores de classificação e regressão foi utilizada para testar o poder preditivo dos fatores de risco - clínicos e radiográficos - na classificação das pacientes nos grupos normal e com perda óssea. A idade e o número de pontos terminais/periferia, seguido da periferia/área trabecular, densidade radiográfica e por último o IMC foram as variáveis que melhor dividiram as pacientes em normais e com perda óssea. Esse estudo conclui que a combinação das variáveis clínicas e radiográficas obtidas por meio de radiografias periapicais é capaz de identificar pacientes com perda de massa óssea. Dessa forma, o cirurgião-dentista está apto a identificar as pacientes com risco de desenvolver osteoporose e encaminhá-las para avaliação médica. / The aim of this study was to determine whether periapical radiograph can be used to identify patients with low bone mass. This goal was accomplished by combining trabecular morphologic analysis with radiographic density measurements as well as with clinical parameters. The study subject consisted of 60 postmenopausal women over forty years of age who were conducted to the Dental Radiology Service of UFRGS School of Dentistry during the year of 2006 to take a periapical radiograph of mandibular premolar and/or molar regions. Additionally, measurements of lumbar spine and proximal femur’s bone mineral density were obtained from these patients by dual-energy X-ray absortiometry, during the same period. The subjects were classified either as normal or with low bone mass according to their bone mineral density. Radiographic density measurements and fourteen morphologic features were obtained from each dental radiograph by the use of digital image processing software. The clinical variables considered were subject´s age and bone mass index (BMI). Classification and regression tree (CART) analysis was used to test the predictive power of clinical and radiographic risk factors to classify individual in either normal or low bone mass classes. CART analysis found that the most important variables for classifying subjects were age, number or terminal points/periphery, periphery/trabecular area, radiographic density and BMI. This study showed that the combination of clinical and radiography factors can identify individuals with low bone mineral density with higher accuracy than either one of the factor taken individually. As a consequence, dentists are able to pre-screen patients with abnormally high risk for developing osteoporosis through standard routine exams and conduct these patients to further medical evaluation whenever necessary.

AN ABSTRACT OF THE DISSERTATION OF VICTOR NOLLEN WHITE, for the Doctor of Philosophy degree in Health Education, presented On November 14, 2014, at Southern Illinois University Carbondale. Title: THE USE OF THE EXPANDED HEALTH BELIEF MODEL (EHBM) TO EVALAUTE OSTEOPOROSIS ATTITUDES, KNOWLEDGE, BELIEFS AND SELF-EFFICACY OF NEZ PERCE TRIBAL AND NON NEZ PERCE TRIBAL MEMBERS IN NEZ PERCE COUNTY, IDAHO. Major Professor: Dr. Dhitinut Ratnapradipa According to the State of Idaho, the National Osteoporosis Foundation, and the U.S. Department of Health and Human Services, osteoporosis is a public health concern nationally among non-Native American (NNA) and Native American (NA) populations. The purpose of this research project is to obtain written survey data on osteoporosis attitudes, knowledge, beliefs, and self-efficacy among male and female members of the Nez Perce Tribe (Nimiipuu) and non-Tribal members, aged 18 and over via voluntary completion of a written survey questionnaire based on the expanded health belief model (EHBM). The study was conducted in Nez Perce County, ID. The research involved determining whether or not there is a statistically significant difference in osteoporosis attitudes, knowledge, beliefs and self-efficacy among males and females, aged 18 and over Nez Perce Tribal members as compared to Non-Tribal members in Nez Perce County, ID. Non-Nez Perce tribal members are individuals whom are 1) Native Americans who are not members of the Nez Perce Tribe and 2) all Non-Native Americans in the research study. Exercise self-efficacy and gender seem to be the most significant variables showing evidence against the null hypotheses and in favor of the research hypothesis (Null Hypothesis: H0: Native American=Non-Native American. Research Hypothesis: H1: Native American ≠ Non-Native American). Age also shows evidence against the null hypothesis and in favor of the research hypothesis, but not as strongly as exercise and gender. Seriousness of osteoporosis was the most concern to all respondents and female Native Americans perceived the greatest barrier to preventing osteoporosis was being unable to access dietary calcium on a regular basis.

Hydroxyproline (Hyp), a non-proteinogenic amino acid is a component of the organic material in bone. It has been used for 14C-dating of bone and the measurement of Hyp could be used as a biomarker in bone metabolism. Hydroxyproline is a component of collagen, the main structural protein in bone. The analyses of 14C in collagen and Hyp in human bones may provide timing information about bone processes and diseases, such as osteoarthritis and osteoporosis. The analysis of Hyp in bones (e.g., the determination of Hyp content) primarily relies on a spectrometric technique, liquid chromatography-mass spectrometry (LC-MS), and the determination of 14C content requires accelerator mass spectrometry (AMS). Moreover, to obtain these materials from bone requires the successful extraction of collagen and thr separation of Hyp from the collagen. This study aims at comparing methods for extracting collagen from bone, which do not destroy the Hyp. These methods include the use of either NaOH, KOH or HCl in one stage of the extraction process and separating sufficient Hyp for 14C analysis. This will provide information to determine whether Hyp can be used as a biomarker for bone diseases like osteoarthritis and osteoporosis. A preliminary 14C AMS analysis on collagen extracted by the NaOH method was carried out on human bones previously analyzed for forensic purposes. This demonstrated the ability of this technique to provide recent (post 1950) timing information. The collagen extractions by three different methods were first conducted on modern chicken bone, and the results showed that KOH method is the best bone collagen extraction method, yielding a largest quantity of Hyp. The KOH method was then employed to extract collagen from cow bone as a test of a more human-like (mammalian) material. As this was successful, collagen was extracted from diseased human bone fragments, obtained from the Ottawa Hospital. The data revealed that Hyp was successfully obtained from these bones. The study demonstrates that the extraction as well as the separation methods (preparative HPLC) can provide sufficient Hyp from bones for 14C AMS analysis. This will lead to future studies of Hyp in bone turnover, which may lead to its use as a novel biomarker for bone diseases such as osteoarthritis and osteoporosis.

Made available in DSpace on 2014-06-11T19:25:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-25Bitstream added on 2014-06-13T19:12:35Z : No. of bitstreams: 1 dallanezi_g_me_botfm.pdf: 1120836 bytes, checksum: a83007c7fba0e34011ee8765a0efdf3b (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O esqueleto representa um dos maiores sistemas do corpo humano, apresentando como principais funções, a manutenção da estrutura corporal e o armazenamento de minerais e proteínas. É composto pelos ossos endocondral, trabecular e cortical. A osteoporose se constitui em um problema clínico e social de relevância, com sérias conseqüências para a saúde dos indivíduos, as quais podem ter grande impacto no desenvolvimento das atividades cotidianas, influenciando no bem-estar e na qualidade de vida relacionada à saúde. Freqüentemente, os pacientes apresentam limitações para exercer suas atividades profissionais, sociais e de lazer, e apresentam uma afecção emocional importante. Além disso, os recursos humanos e financeiros utilizados no tratamento da osteoporose e, principalmente, das fraturas, são significativos, com desequilíbrio na qualidade de vida não só dos pacientes como também de seus familiares. A atividade física (AF) vem sendo, recentemente, listada como um dos principais indicadores de saúde. A Organização Mundial de Saúde vem estimulando a participação dos profissionais de saúde, familiares e a comunidade, para que programas de estímulo à AF sejam desenvolvidos. Os exercícios físicos não precisariam ser vigorosos, bastando serem moderados, contanto que praticados de forma regular. Segundo o American College of Sports Medicine e o Center for Disease Control, todos os indivíduos, a partir da idade dos dois anos, devem desenvolver 30 minutos de atividade física de moderada a intensa, durante pelo menos 3 a 5 dias (dependendo da intensidade do exercício e grau de condicionamento da pessoa), podendo chegar até a todos os dias da semana. Os indivíduos que não se enquadram dentro desse conceito são considerados sedentários. A interface entre a prática de atividade física e a prevenção e tratamento da osteoporose se constitui... / The skeleton is the largest system in the human body. Its primary functions are support of the body structure and storage of minerals and proteins. It is formed by the endochondral, trabecular and cortical bones. Osteoporosis is a clinical and social problem of relevance with serious consequences to health. It has a great impact on everyday activities influencing the well being and quality of life of the individuals affected. The professional, social and leisure activities of these individuals are often limited and associated with emotional impairment. Moreover, the human and financial resources spent in the treatment of osteoporosis and fractures, in particular, may significantly imbalance the quality of life of the patients as well as that of their family members. Physical activity (PA) has been recently listed as one of the major health indicators. The World Health Organization encourages the participation of health professionals, family members and the community in the development of programs to stimulate PA. Moderate, rather than vigorous activity is enough, provided that physical exercises are regularly taken. According to the American College of Sports Medicine and the Center for Disease Control, all individuals older than 2 years should engage in 30 minutes of moderate to intense physical activity on at least 3-5 days (depending on exercise intensity and individual fitness level) to, preferably all, days of the week. The individuals that do not fall into this category are considered sedentary. The relation of physical activity practice with the prevention and treatment of osteoporosis is an instigating object of investigation. Patients with reduced bone mass do not get enough physical activity. to evaluate the level of physical activity and quality of life among patients with osteoporosis and osteopenia attending the outpatient clinic of Calcium Disorders of Botucatu Medical School... (Complete abstract click electronic access below)