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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.
71

Évolution du cancer du testicule en Europe : expositions environnementales et professionnelles / Burden of testicular cancer in Europe : environmental and occupational exposures

Le Cornet, Charlotte 10 December 2014 (has links)
Les tumeurs germinales du testicule (TGT) représentent le cancer le plus fréquent chez les hommes Européens âgés de 15 et 39 ans. L'incidence a doublé dans la plupart des pays Européens depuis 30 ans. Cette augmentation rapide, les variations géographiques d'incidence et les études chez les populations migrantes suggèrent un rôle des facteurs environnementaux dans le développement des TGT. Cette thèse propose de contribuer à l'amélioration des connaissances concernant l'évolution du TGT en clarifiant l'impact des expositions environnementales et professionnelles, notamment pendant la période prénatale. Les objectifs principaux sont de: 1. Prédire l'incidence du TGT jusqu'en 2025 en estimant la part d'augmentation due aux changements démographiques afin d'obtenir une estimation de l'augmentation due aux risques. 2. Faire un bilan de l'état des connaissances sur l'association entre les expositions environnementales et professionnelles et le développement du TGT dans une revue systématique de littérature 3. Investiguer l'association entre l'exposition parentale professionnelle aux pesticides en période prénatale et le TGT parmi la descendance Les résultats montrent que l'incidence du TGT continue d'augmenter, mettant en avant un fort impact environnemental dans l'évolution du TGT. Néanmoins, la revue de littérature ne permettait pas d'identifier de facteurs de risque environnementaux avérés, mais montrait un manque d'études investiguant les expositions prénatales sur le risque de TGT. L'étude NORD-TEST menée sur les données de registre de quatre pays nordiques est l'étude la plus puissante à ce jour et ne montre aucune association entre l'exposition parentale professionnelle aux pesticides en période prénatale et le TGT / Testicular germ cell tumours (TGCT) are the most common cancer diagnosed among young European men aged between 15 and 39 years. TGCT incidence rates have doubled in most European countries over the last 30 years. This rapid increase in incidence, the geographical variations and the studies in migrant populations suggest a role of environmental factors in TGCT aetiology. This thesis aims to contribute to the knowledge of TGCT evolution by studying the impact of environmental and occupational exposures, especially during the prenatal period. The objectives are: 1. To estimate the proportion of the increased incidence due to overall changes in risk patterns compared to the proportion due to demographic changes, by predicting the future testicular cancer trends in Europe 2. To summarize and evaluate the current knowledge on environmental and occupational exposures related to TGCT risk by means of a systematic literature review 3. To investigate the association between the prenatal parental occupational exposure to pesticides and TGCT risk in the offspring. The results show that the TGCT incidence continues to increase, supporting an environmental impact on TGCT evolution. From the epidemiological literature to date no specific environmental risk factors emerge; however, there have clearly been a lack of studies investigating prenatal exposures on TGCT risk. The NORD-TEST study, based on registry data from four Nordic countries, is the largest study to date. No association was found between parental occupational exposure to pesticides during prenatal period and TGCT risk
72

A study of the aetiology and epidemiology of cancers in teenagers and young adults

Arora, Ramandeep January 2011 (has links)
Introduction: Little is known about the aetiology of cancer in teenagers and young adults (TYA) aged 15-24 years, although in England, cancer is the most common cause of disease-related mortality in this age group. The most common cancers at this age are lymphomas, central nervous system (CNS) tumours and germ cell tumours (GCT). The commonest carcinomas seen at older ages including lung, breast, large bowel and prostate account for only 3-4% of TYA cancers. In this thesis I describe the incidence patterns of selected cancers in TYA and the variation seen with geography, time and in population subgroups. The focus is on CNS tumours, GCT and bone tumours as they either peak in incidence in TYA and/or contribute disproportionately to cancer related mortality in TYA. This will allow formulation of hypotheses regarding aetiology of cancer in this age group which can then be tested by further research. Methods: For the majority of the analysis, anonymised national cancer registration data from England on individual patients of all ages with newly diagnosed cancer between 1979 and 2003 were used. To contrast the incidence patterns in England with that of India, data from five Indian urban population based cancer registries were used for part of the analysis. Age, sex, site and histology specific incidence rates were calculated and expressed per million person years. All rates, where appropriate, were adjusted to the world standard population using direct methods. To explore the link of growth with development of osteosarcoma and Ewing sarcoma, a random-effects meta-analysis was undertaken on studies which investigated an association of these tumours with height at diagnosis. Results: The incidence of cancer in TYA overall in England exceeded that of India. This was also true for most individual sites including epithelial cancers of lung, colon/rectum, breast, ovary and cervix, and non-epithelial cancers including melanoma, Hodgkin lymphoma and testicular cancer. Notable exceptions to this pattern were cancers of the mouth, gall bladder and stomach (females only) where incidence was higher in India. In England, CNS tumours in TYA were a composite of pilocytic astrocytomas and embryonal tumours (representing tail end of childhood CNS tumours), pituitary tumours, nerve sheath tumours, high grade astrocytomas and meningiomas (representing early-onset of CNS tumours that peak in incidence in the 6th and 7th decade of life), and of CNS GCTs, pleomorphic xanthoastrocytomas and neurocytomas which show a peak incidence in TYA. Irrespective of site or histology, GCT in England showed a peak in incidence between ages of 10 to 39 years which was more marked in males. This however varied by site and the peak incidence was seen at 10 to 14 years in the CNS, 15 to 19 years in ovary, 25 to 29 in mediastinum & thorax and abdomen & pelvis, and 30 to 34 years in testicular tumours. Osteosarcoma and Ewing sarcoma were the predominant bone tumours in TYA in England and showed a distinct peak of incidence at 10 to 14 years age in females and a larger peak at 15 to 19 years age in males. The peak incidence of osteosarcoma of long bones of the lower limb was six times more than that at any other site while the peak incidence of Ewing sarcomas located in the bones of the central axis exceeded those in long bones of the lower limb. The average height of patients with osteosarcoma at diagnosis was found to be significantly above the average height of the reference population, at the 95% level. The association of greater height at diagnosis with Ewing sarcoma was also significant at the 95% level but much weaker. Conclusion: In this thesis I have explored the epidemiology of cancer in TYA using some of the established methodologies which have previously been used in advancing our knowledge of childhood and older adult cancers. These studies provide some clues to aetiology. Variation in environmental exposures and lifestyle factors between England and India can explain the majority of the differences in incidence patterns observed. Genetic predisposition to cancer along with carcinogen exposure could lead to early onset of some cancers generally seen in older adults. Regardless of site, the similarity in age-incidence patterns of GCT, suggests a common initiation of these tumours in embryonic/foetal life with variable rates of tumour progression as a result of local factors or events during postnatal and pubertal period. The incidence patterns of osteosarcoma along with the strong and consistent association with a greater height at diagnosis indicate that bone growth is important in the development of this tumour while different biological pathways which may be unrelated to growth could also be relevant for Ewing sarcoma.
73

SCF-mediated degradation of the two translational regulators, CPB-3 and GLD-1, during oogenesis in C. elegans

Kisielnicka, Edyta 05 August 2017 (has links)
The development of an organism and its adult homeostasis rely on regulatory mechanisms that control the underlying gene expression programs. In certain biological contexts, such as germ cell development, gene expression regulation is largely executed at the post-­‐transcriptional level. This relies on RNA-­‐binding proteins (RBPs), whose activity and expression are also heavily controlled. While the RNA-­‐binding potential of RBPs is currently of intense scrutiny, surprisingly little is known to date about the molecular mechanisms that control RNA-­‐binding proteins abundance in the context of germ cell development. This work identifies the molecular mechanisms that shape expression patterns of two evolutionarily conserved RNA-­‐binding proteins, CPB-­‐3 and GLD-­‐ 1, which belong to CPEB and STAR protein family, respectively. By focusing on their regulation in the C. elegans germ line, this work reveals an involvement of the proteasome in reducing levels of CPB-­‐3/CPEB and GLD-­‐1/STAR at the pachytene-­‐to-­‐diplotene transition during meiotic prophase I. Furthermore, it documents that CPB-­‐3 and GLD-­‐1 are targeted to proteasomal degradation by a conserved SCF ubiquitin ligase complex that utilises SEL-­‐10/Fbxw7 as a substrate recognition subunit. Importantly, destabilisation of both RBPs is likely triggered by their phosphorylation, which is regulated by the mitogen-­‐activated protein kinase, MPK-­‐1, and restricted to the meiotic timepoint of pachytene exit. Lastly, this work investigates the potential consequences of target mRNA regulation upon delayed RBP degradation. Altogether, the collected data characterise a molecular pathway of CPEB and STAR protein turnover, and suggest that MPK-­‐1 signaling may couple RBP-­‐mediated regulation of gene expression to progression through meiosis during oogenesis.
74

DEADEND1 GENETICS IN MOUSE MODELS OF TESTICULAR GERM CELL TUMOURS AND THEIR METASTASES

Zechel, Jennifer Lynn 23 August 2013 (has links)
No description available.
75

Zur Problematik der Spätrezidive von Hodentumoren

Nabavi, Roya 03 November 2005 (has links)
Welche Ursachen führen bei Keimzelltumoren zu Spätrezidiven? Sind es ungünstige Tumorkonstellationen, Behandlungsfehler oder individuelle Faktoren, die zu Spätrezidiven von Keimzelltumoren (KZT) führen? Ziel der Untersuchung war es, diese Fragen zu beantworten, um Patienten zu identifizieren, für die sich daraus Konsequenzen in der Therapie und Verlaufskontrolle ergeben. Indem wir Spätrezidive nach 4 Jahren auswerteten, wollten wir die besonderen Merkmale dieser Patientengruppe herausarbeiten. Unter 759 erfassten Patienten sahen wir 165 Frührezidive (< 2 Jahre), 92 Rezidive nach 2 Jahren und 73 Spätrezidive mehr als 4 Jahre nach der Initialdiagnose. Unsere statistische Auswertung bezieht sich auf die Spätrezidive mit einer mittleren Beobachtungszeit von 143 Monaten. Die initiale Konstellation der Tumormarker spielt eine bedeutende Rolle. 66% der Patienten hatten sowohl AFP als auch ß-HCG erhöht (gegenüber 47% bei den Frührezidiven und 33% im Gesamtkollektiv). Das gonadal reine Embryonalzellkarzinom (EZK) führt häufiger zu Spätrezidiven als andere Keimzelltumoren. Risikobehaftet sind höhere Stadien, von denen sich unter den Spätrezidiven 85% fanden; initial aber nur 57%. Demgegenüber ist poor-prognosis nach IGCCCG kein Risikofaktor. Mehr als die Hälfte der spätrezidivierten Patienten hatte bereits vorher mindestens ein Rezidiv gehabt. Eine initial von der heutigen Leitlinie abweichende Behandlung war bei 40% der Spätrezidive zu finden. Gründe hierfür waren eine falsche Histologie, die ungenaue Stadienzuordnung oder eine fehlende bzw. inkomplette Residualtumorresektion. Eine günstige Prognose haben die Patienten, bei denen eine Metastasenresektion vorgenommen werden kann. Die Heilungsrate (NED) war bei den operierten Spätrezidiven (70%) deutlich hoher als denjenigen, die zusätzlich chemotherapiert (46%) oder lediglich mit Chemotherapie behandelt worden waren (36%). Als Grund hierfür, ist die Früherkennung und noch vorhandene Operabilität des Befundes anzunehmen. Alle Seminom-Spätrezidive mit initialer Radiatio haben von der Chemotherapie profitiert. Bis auf einen Todesfall in der Chemotherapie wurden alle geheilt. Spätrezidive von KZT sollten als besondere Entität definiert werden. Krankheitsverlauf, Behandlung und Nachsorge weichen von dem üblichen Muster ab. Nur Seminome oder chemonaive Patienten sind zytostatisch zu behandeln. Bei den Nichtseminomen, die bereits initial oder im Frührezidiv eine Chemotherapie erhalten haben, sollte wenn möglich, eine operative Behandlung erwogen werden. Patienten mit initial erhöhten Tumormarkern (AFP + ß-HCG), reinem gonadalem EZK, höheren Krankheitsstadien oder einem Rezidiv innerhalb der ersten 4 Jahre haben eine ungünstige Prognose und erfordern eine jährliche lebenslange spezielle Nachsorge. Die Nachsorge sollte neben der klinischen Untersuchung und AFP-Bestimmung ein Schnittbildverfahren des Thorax und Retroperitoneums beinhalten. / What are the reasons for late relapse of testicular germ cell tumor? Do unfavourable tumor constellations, mismanaged treatment or individual factors; lead to the late relapse of testicular germ cell tumor? The aim of this investigation was to find an answer to this question and to identify the patients, who would benefit from modified treatments and follow-up modalities. By researching the late relapses diagnosed at least 4 years later, we wanted to identify the special characteristics of this group of patients. Among the 759 patients with testis cancer we found 165 early relapses (
76

Zur Rolle von Stra8 in pluripotenten Stammzellen / On the role of Stra8 in pluripotent stem cells

Kotzenberg, Linda 25 January 2011 (has links)
No description available.
77

Characterization of the Role of <i>aeneas</i> in Primordial Germ Cell Migration and Blastoderm Cellularization / Charakterisierung der Funktion von <i>aeneas</i> in der Migration Primordialer Keimzellen und der Zellularisierung des Blastoderms

Graf, Roland Jan 22 June 2007 (has links)
No description available.
78

Molecular Mechanisms Controlling Guided Germ Cell Migration in Zebrafish / Molekulare Mechanismen zur Kontrolle der gezielten Zellwanderung primordialer Keimzellen im Zebrafisch

Boldajipour, Bijan 11 August 2009 (has links)
No description available.
79

Molecular Therapy in Urologic Oncology

Fröhner, Michael, Hakenberg, Oliver W., Wirth, Manfred P. 14 February 2014 (has links) (PDF)
During recent years, significant advances have been made in the field of molecular therapy in urologic oncology, mainly for advanced renal cell carcinoma. In this hitherto largely treatment-refractory disease, several agents have been developed targeting the von Hippel-Lindau metabolic pathway which is involved in carcinogenesis and progression of the majority of renal cell carcinomas. Although cure may not be expected, new drugs, such as the multikinase inhibitors sorafenib and sunitinib and the mammalian target of rapamycine inhibitor temsirolimus, frequently stabilize the disease course and may improve survival. Fewer data are available supporting molecular therapies in prostate, bladder, and testicular cancers. Preliminary data suggest a potential role of high-dose calcitriol and thalidomide in hormone-refractory prostate cancer, whereas targeted therapies in bladder and testicular cancers are still more or less limited to single-case experiences. The great theoretical potential and the multitude of possible targets and drug combinations, however, support further research into this exciting field of medical treatment of urologic malignancies. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
80

Zur Rolle von N-Cadherin in der Proliferation, Migration und Invasion maligner Keimzelltumoren des Hodens / Role of N-cadherin in proliferation, migration, and invasion of germ cell tumours.

Schallenberg, Simon 12 December 2019 (has links)
No description available.

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