Diss. (sammanfattning) Umeå : Univ., 2004. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Univ., 2001. / Härtill 5 uppsatser.

To Wing Kee William. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 102-118). / Abstracts in English and Chinese ; questionnaires in Chinese. / Declaration --- p.3 / List of Abbreviations and definitions --- p.4 / List of Tables and Figures --- p.5 / Acknowledgement --- p.6 / Abstract of thesis --- p.7 / Chapter Chapter 1 --- "Menstrual dysfunction, physical exercises and bone mineral density - a review" --- p.12 / Chapter Chapter 2 --- Assessment of bone mineral density in young females - a review --- p.29 / Chapter Chapter 3 --- Objectives of the study --- p.33 / Chapter Chapter 4 --- A comparison of bone mineral density in adolescents with polycystic ovaries and normal ovaries --- p.42 / Chapter Chapter 5 --- The effects of oligomenorrhoea and amenorrhoea on bone mineral density in collegiate dance students --- p.57 / Chapter Chapter 6 --- Comparison of bone mineral density in young dancers and non-dancing young women --- p.70 / Chapter Chapter 7 --- Rate of interval changes in bone mineral density in exercising and non-exercising young women - an 18-month longitudinal assessment --- p.82 / Chapter Chapter 8 --- Summative discussion and conclusion --- p.95 / References --- p.102 / Appendix 1 Questionnaire for recruited dance students --- p.119 / Appendix 2 Information sheet and consent form for dance students --- p.124 / Appendix 3 Questionnaire for subjects recruited from Adolescent Clinic --- p.125 / Appendix 4 Proformer sheet for subjects recruited from Adolescent Clinic --- p.129 / Appendix 5 Consent form and information sheet for subjects from Adolescent Clinic --- p.130 / Abstracts presented in relation to thesis --- p.134 / Papers submitted in relation to thesis --- p.135

Orientador: Ilza Maria Urbano Monteiro / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-14T22:30:01Z (GMT). No. of bitstreams: 1 Makuch_MariaValeriaBahamondes_M.pdf: 9936891 bytes, checksum: f5cea3f3dd8db3f9c34d0b9e9f0a4d3c (MD5) Previous issue date: 2006 / Resumo: Introdução: A osteoporose é uma doença sistêmica que afeta principalmente as mulheres. Alguns dos fatores que aceleram a aparição desta doença são a idade e o uso, por longa data, de métodos anticoncepcionais com somente progestágenos. O sistema intrauterino liberador de levonorgestrel (SIU-LNG) é um método difundido para a contracepção e o tratamento de diversas patologias ginecológicas. Na literatura não foram identificados estudos longitudinais prospectivos, com usuárias de longa data deste método, que avaliem seus efeitos sobre a densidade mineral óssea (DMO). Objetivos: Avaliar a DMO em usuárias do SIU-LNG aos sete anos de uso e comparar com elas mesmas aos 10 anos de uso e com um grupo-controle de usuárias de método anticoncepcional não hormonal. Sujeitos e métodos: do total de 37 mulheres que realizaram DMO no antebraço aos sete anos de uso do SIU-LNG, foi avaliada a DMO novamente aos 10 anos de uso. Cada usuária foi pareada com uma usuária de DIU TCu380A, com o mesmo tempo de uso, por idade (± 1 ano), índice de massa corporal (IMC; kg/m2) (± 1), cor da pele e número de gravidezes (± 1). A DMO foi avaliada no antebraço não dominante no rádio distal (midshaft ulna) e no rádio ultradistal usando double X-ray absorptiometry. Os dados foram avaliados pelos testes t de Student pareado, Wilcoxon, Snedecor (ANOVA) e Índice de correlação múltipla. Resultados: A DMO das usuárias do SIU-LNG aos 10 anos de uso foi estatisticamente similar que aos sete anos e similar que os seus controles, usuárias de DIU TCu380A, mesmo quando pareadas por idade (± 1 ano), índice de massa corporal [IMC; kg/m2, (± 1)], cor da pele e número de gestações (± 1). A maior DMO das usuárias do SIU-LNG aos 10 anos foi significativamente associada ao maior IMC (kg/m2) e maior DMO aos sete anos de uso. Conclusão: As DMO dos antebraços distal e ultradistal foram similares entre as usuárias do SIU-LNG aos sete e 10 anos de uso, e também quando comparadas com um grupo de não usuárias deste contraceptivo / Abstract: Introduction: Osteoporosis is a systemic disease which mainly affects women. Some of the factors which provoke an acceleration of the initiation of this disease were age and use for a long-term of progestin-only contraceptive methods. The levonorgestrel-releasing intrauterine system (LNG-IUS) is widely introduced method for contraception and for the treatment of several gynecological pathologies. On the literature we were unable to identify prospective studies with long-term users of this method which evaluated their effect upon bone mineral density (BMD). Objectives: To assess prospectively the BMD of users of the LNG-IUS at the 7th year of use and compare with the same women at the 10th year of use and with a control group of users of a non-hormonal contraceptive method. Materials and methods: A total of 37 women who performed a forearm BMD at the 7th year of use and again at the 10th year of use. Each woman was paired with a woman who had been using a copper IUD TCu380A for at least the same length of time, who never use an LNG-IUS matched by age (±1 year), body mass index (BMI; kg/m2) (±1), ethnicity, and number of pregnancies (±1). BMD was evaluated at the distal and the ultra-distal radius of the nondominant forearm using double X-ray absorptiometry. The data was evaluated trough t-Student test for paired samples, Wilcoxon, Snedecor (ANOVA) and multiple logistic regression. Results: The BMD of LNG-IUS users at the 10th year of use was statistically similar than themselves when use at the 7th year as well as similar as controls users of the TCu380A IUD even when paired by age (± 1 year), body mass index (BMI; Kg/m2, (± 1), race and number of pregnancies (± 1). Higher BMD of the LNG-IUS at the 10th year of use was significantly associated to a high BMI (Kg/m2) and higher BMD at the 7th year of use. Conclusions: Forearm BMD at distal and ultra-distal radius was similar among users of the LNG-IUS at the 7th and at the 10th year of use and was also similar when compared users with non-users of this contraceptive method / Mestrado / Tocoginecologia / Meste em Tocoginoclogia

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Original published work submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy, August 2019 / Age-at-death estimates in skeletal remains are hampered by observer bias and error, as well as individual and population variation. This study aimed at improving accuracy and reliability of age estimates obtained from applying methods involving the assessment of histomorphometric variables of bone and bone mineral density (BMD). The assessment of osteon population density (OPD) and size (length, surface area and volume) of Haversian systems were investigated in three populations by means of stereology. Bone slides prepared from South African black (n = 99), South African white (n = 94) and Danish white (n = 30) individuals were analysed using MicroBrightField’s StereoInvestigator software. ANCOVA results revealed a statistically significant difference (p < 0.001) between the three groups in terms of OPD. No statistically significant difference was seen in the size of secondary osteons between the groups. Linear regression analysis was used to construct population-specific formulae for age-atdeath estimation in South African white and black individuals. The Danish sample was used as a comparative group for white South African standards established. Age mimicry appeared to play a role in the over-estimation of age in the Danish individuals, after which the problem was corrected by combining the two samples in order to achieve normal age distribution within the larger sample. Secondly, DXA scans of the proximal femur were done for a subgroup of South African black (n = 64) and white (n = 59) individuals for estimation of age-at-death from bone mineral density. Results displayed a significant difference between white and black groups for total and neck BMD. White males and females differed in total and neck BMD, although black males and females differed only in terms of neck BMD. Age could be significantly correlated with BMD in the white population, but not in the black population. Regression analysis was also done for the complete sample (white and black individuals pooled), as ancestry is unknown in some cases. A significant correlation was seen for age versus neck BMD in the total sample and in sex-specific groups. The outcome of this study suggested that the three population samples are somewhat dissimilar in bone microstructure, with differences related to OPD and BMD present between the groups. Based on this outcome, it should be emphasized that age estimation standards should be adapted to accommodate combined groups and create to more generally applicable standards. Further research involving various disciplines is needed to better understand the underlying reason(s) for these differences between these populations. / PH2020

Type 1 diabetes mellitus (T1D) is an autoimmune disease that results in deficient production of insulin from pancreatic beta cells. In addition to glycemic control irregularities, T1D can have profound effects on other metabolic processes in the body. Of these, bone, muscle, and adipose tissue metabolism are of interest in the fields of bone density and fracture risk. When combined with a diagnosis of T1D, the lifetime risk of fracture is up to four times higher; however, the relative risk of fracture highest in adulthood. This is of concern as fractures later in life have been shown to have adverse consequences on overall health. Understanding how fat mass and lean mass affect fracture risk in participants with and without T1D has the potential to provide support for accurately predicting and managing this fracture risk. In this cross-sectional analysis of adolescent girls ages 9 -18 with and without T1D, both groups were well matched in most areas, and significant differences between the two groups were seen at body mass index (BMI), BMI Z-score, lean mass index (LMI), LMI Z-score, hemoglobin A1c (HbA1c), and parathyroid hormone (PTH). The calculated predicted force of fall and measured failure load at the distal radius were used to investigate the load-to-strength ratio (LSR). The LSR has the potential to be beneficial in directly assessing fracture risk. From the analysis, it is possible to propose more in-depth studies of the hypothesized positive and negative effects of fat mass and lean mass, respectively on fracture risks.

Bone growth and remodeling are complex phenomena that are influenced by a variety of factors including mechanical stimuli. However, it is still unclear how to identify and quantitatively characterize the mechanical stimuli responsible for bone cell growth. The objective of this study is to design and simulate an experimental apparatus to cyclically apply pressure and shear stresses to bone cells and observe their growth (or lack thereof) as a function of the applied loads.

This essay focuses on developing non-destructive methods to investigate the relationship between elemental distribution and bone porosity in archaeological bone. The skeletal material, which was analyzed, came from the archaeological sites of Skara (county of Västergötland), Varnhem (county of Västergötland), Sigtuna (county of Uppland) and Kopparsvik (county of Gotland). The essay is based on the results of a previous project, Osteoporosis och osteoarthritis, då och nu (Sten 2012). That project aimed at establishing whether medieval people, buried on the above mentioned archaeological sites, were suffersing from osteoporosis and/or osteoarthritis. This knowledge might help the medical research of today to solve the problem of possibly preventing those bone diseases. The method used was DXA-scanning, which was developed for examine osteoporosis in bone from living people. The result showed that the skeletons from the Skara site had an increased bone mineral density (BMD) compared to the skeletons from the other three sites. This essay investigates why these skeletal remains have a higher BMD and how this affects the results of methods like DXA. In this bachelor project various X-ray instruments were used to analyze the BMD of the skeletal remains. The X-ray pictures were then modified to exhibit high and low density areas in the bone. The elemental distribution of the surface area of the neck of the femur was examined with a μXRF-spectrometer. As a complement to the μXRF-spectrometer a SEM (scanning electron microscope) was used to analyze the elemental distribution of a cross section of the femur neck. Soil samples were collected from Skara and Varnhem and analyzed by using μXRF-spectrometry to find out if there was a correlation between the elemental content of the bone and surrounding soil. The skeletal remains from Skara exhibited increased values of iron and manganese combined with higher bone density. The soil from Skara showed a high level of particularly iron. This could be the reason for the increased BMD of the individuals from Skara when using the DXA-analysis. It is likely that, in each archaeological site, iron and manganese ions have diffused from both ground water and soil into the bones and thus increased the BMD. This is especially notified of the skeletal remains of Skara.

Many phenotypes are controlled by factors which include the genes, the environment, interactions between genes and interaction between the genotypes and the environment. Great strides have been made to understand how these various factors affect traits of agricultural, medical and environmental importance. The chicken is regarded as a model organism whose study would not only assist efforts towards increased agricultural productivity but also provide insight into the genetic determination of traits with potential application in understanding human health and disease. Detection of genomic regions or loci responsible for controlling quantitative traits (QTL) in poultry has focussed mainly on growth and production traits with limited information on reproductive traits. Most of the reported results have used additive-dominance models which are easy to implement because they ignore epistatic gene action despite indications that it may be important for traits with low heritability and high heterosis. The thesis presents results on the detection of loci and genetic mechanisms involved in sexual maturity traits through modelling both additive-dominance gene actions and epistasis. The study was conducted on an F2 broiler x White Leghorn layer cross for QTL detection for age, weight, abdominal fat, ovary weight, oviduct weight, comb weight, number of ovarian yellow follicles, a score for the persistence of the right oviduct and bone density. In addition, body weight QTL at 3, 6, 12, 24, 48 and 72 weeks of age, QTL for growth rate between the successive ages and QTL for the parameters of the growth curve were also detected. Most of the QTL for traits at sexual maturity acted additively. A few of the QTL explained a modest proportion of the phenotypic variation with most of the QTL explaining a small component of the cumulative proportion of the variation explained by the QTL. Body weight QTL were critical in determining the attainment of puberty. The broiler allele had positive effects on weight at first egg and negative effects on age at first egg. Most QTL affecting weight at first egg overlapped with QTL for age at first egg and for early growth rate (6-9 weeks) suggesting that growth rate QTL are intimately related to the onset of puberty. Specific QTL for early and adult growth were detected but most QTL had varying influence on growth throughout life. Chromosome 4 harboured most of QTL for the assessed traits which explained the highest proportion of the phenotypic variation in the traits confirming its critical role in influencing traits of economic importance. There was no evidence for epistasis for almost all the studied traits. Evidence for role of epistasis was significant for ovary weight and suggestive for both growth rate and abdominal fat.