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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.
1

Craniofacial Bone Density is Regulated by Thyroid Hormone in Zebrafish:

May, Catherine M. January 2019 (has links)
Thesis advisor: Sarah McMenamin / Thyroid hormone (TH) facilitates developmental transitions, particularly by modulating cell proliferation and differentiation. Its role in regulating skeletal growth is well documented. Previous work from our lab and others have demonstrated that hypo- and hyperthyroid fish display changes in bone shape, ossification and the timing of ossification5. Zebrafish (Danio rerio) develop bone quickly, grow indefinitely throughout their lives, are highly amenable for imaging, and are a valuable model for skeletal biology research. Using Danio rerio, we sought to study the long-term effects of TH on bone density by rearing and comparing normal euthyroid (Eu) with a transgenically thyroid-ablated hypothyroid (TH-) and mutant hyperthyroid (TH+) fish. We found that TH strongly affects bone density and volume. We further hypothesize that TH is critical for the timing and fidelity of skeletogenesis. In hormone-dysregulated fish, we found that massive bone and cartilage exostoses grow on the dentary. Thyroid hormone’s effects are highly bone-specific: in TH- fish, we see reduced density in many craniofacial bones, but also increased volume and mineralization in other regions of the dentary. These data suggest that TH plays a critical role in coordinating bone mineralization with growth. / Thesis (MS) — Boston College, 2019. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Biology.
2

Diagnostic anténatal des nanismes constitutionnels par échographies et radiographie.

Harter, Barbara Münch, January 1900 (has links)
Th. Méd.--Nancy 1, 1983. N°: 96.
3

Description et étiologie des exostoses oro-faciales : exemple d'une population thaïlandaise / Description and etiology of oral exostoses : the example of a Thai population

Léonard, Anneliese 27 October 2014 (has links)
Cette thèse vise à participer à une meilleure connaissance des exostoses oro-faciales comme variation anatomique et préciser leur possible utilisation en anthropologie biologique. Une nouvelle méthodologie a été conçue pour faciliter leur enregistrement tant sur restes squelettiques qu’individus vivants. L’étude a été réalisée sur une population thaïlandaise : la collection anatomique de référence de la faculté de médecine de Chiang Mai. Cette population a été choisie pour ses hautes fréquences et forte expressivité des exostoses oro-faciales, ainsi que son homogénéité génétique. Les exostoses oro-faciales ont été évaluées par présence/absence et métriquement. Leur relation au sexe, à l’âge et entre leurs différents types est détaillée et les étiologies discutées. La composante génétique est évaluée sur la base de l’homogénéité populationnelle et les liens entre exostoses et variations anatomiques dentaires et crâniennes. La composante environnementale inclut des données sur l’alimentation, le stress occlusal et la santé orale. Les exostoses oro-faciales apparaissent comme un ensemble de caractères liés entre eux et très influencés par l’âge. Toutes les exostoses sauf l’exostose palatine sont significativement liées au sexe avec prédominance masculine. Les exostoses oro-faciales n’appartiennent pas aux variations hyperostotiques. Les liens récurrents avec certaines variations anatomiques dentaires suggèrent une base génétique. Les exostoses oro-faciales émergent préférentiellement quand un maximum de dents saines et peu usées sont présentes, mais l’édentation de large étendue ne réduit pas leur prévalence, ni leur expressivité. L’influence environnementale locale n’est pas caractéristique d’un stress fonctionnel. Le régime traditionnel asiatique pourrait être une influence conséquente par son caractère promoteur du tissu osseux. La double participation génétique et environnementale au processus étiologique suggère que les exostoses oro-faciales appartiennent aux variations quasi-continues. / We aim here at participating in a better understanding of oral exostoses as an anatomical variant in order to clarify their possible use in biological anthropology. We propose a new study design that could be applied both on skeletal remains and living individuals and that allows discuss the etiology of oral exostoses. The research has been undertaken on the anatomical reference collection of the faculty of medicine of Chiang Mail, Thailand. The Thai population displays a wide array of expression of oral exostoses and a great genetic homogeneity. The oral exostoses have been scored by presence/absence and their measurements. The genetic component has been evaluated through population homogeneity and the relationships between oral exostoses and dental and cranial anatomical variants. The environmental component includes data on diet, occlusal stress and oral health. Oral exostoses appear as a set of characters linked together and strongly influenced by age. All types of oral exostoses except the palatine exostosis are correlated with sex with a male predominance. Oral exostoses do not belong to hyperostotic variants. The recurring relationships with dental anatomical traits point to a genetic basis. Oral exostoses preferentially arise when the greatest number of healthy, unworn teeth is present, although extensive edentulousnes does not lessen both their presence and their expressivity. The local environmental context is not typical of functional stress. The traditional Asian diet may be a substantial influence because of its bone-promoting composition. A dual participation of both genetic and environmental components to the etiological process implies that oral exostoses are quasi-continuous variants.

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