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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

Function of proEGF cytoplasmic domain in thyroid cancer

Glogowska, Aleksandra Maria 14 September 2010 (has links)
Epidermal Growth Factor (EGF) is a member of the EGF-like family. EGF binding to the Epidermal Growth Factor Receptor (EGFR) affects cell survival as well as proliferation, migration, and tissue differentiation. Over-expression along with ligand-induced activation of EGFR has been correlated with increased in vivo invasiveness of tumor cells and enhanced in vitro migration of cell lines. This in turn makes EGFR a very important target for cancer therapy. In our investigation we have discovered that the cytoplasmic domain of proEGF (proEGFcyt) has the ability to decrease proliferation and migration in thyroid carcinoma cell lines. We illustrated that proEGFcyt causes specific alterations in the microtubular (MT) phenotype and the composition of MT-associated proteins (MAP) in FTC-133 overexpressing proEGFcyt, a finding not observed in FTC-133 over-expressing a novel splice form of proEGFcyt with a deletion of the complete exon 23 (proEGFdel23) (Pyka et al., 2004). Here, we demonstrate that proEGFcyt suppresses motility and elastinolytic activity in human thyroid Ca cells as a result from reduced secretion of cath-L. This impaired the ability of thyroid Ca cells to penetrate elastin matrices. The reduction in cath-L secretion was as a result of an up-regulation of SNAP25, a member of the t-SNARE plasma membrane complex, which is involved in Ca2+-dependent exocytosis. Furthermore, we demonstrated that proEGFcyt-mediated silencing of UCH-L1 causes the decrease in EGFR due to enhanced EGFR ubiquitination. This correlated with altered proteasomal degradation and provides a unique new mechanism on how proEGFcyt can affect cell proliferation in human thyroid cancer cells. These studies identified novel functions of human proEGF as a bidirectional signaling molecule consisting of the known extracellular EGF domain which functions as the classical ligand and activator of EGFR-mediated cell growth and the proEGF cytoplasmic domain which has the ability to suppress migration and growth of human thyroid carcinoma cells.
2

Function of proEGF cytoplasmic domain in thyroid cancer

Glogowska, Aleksandra Maria 14 September 2010 (has links)
Epidermal Growth Factor (EGF) is a member of the EGF-like family. EGF binding to the Epidermal Growth Factor Receptor (EGFR) affects cell survival as well as proliferation, migration, and tissue differentiation. Over-expression along with ligand-induced activation of EGFR has been correlated with increased in vivo invasiveness of tumor cells and enhanced in vitro migration of cell lines. This in turn makes EGFR a very important target for cancer therapy. In our investigation we have discovered that the cytoplasmic domain of proEGF (proEGFcyt) has the ability to decrease proliferation and migration in thyroid carcinoma cell lines. We illustrated that proEGFcyt causes specific alterations in the microtubular (MT) phenotype and the composition of MT-associated proteins (MAP) in FTC-133 overexpressing proEGFcyt, a finding not observed in FTC-133 over-expressing a novel splice form of proEGFcyt with a deletion of the complete exon 23 (proEGFdel23) (Pyka et al., 2004). Here, we demonstrate that proEGFcyt suppresses motility and elastinolytic activity in human thyroid Ca cells as a result from reduced secretion of cath-L. This impaired the ability of thyroid Ca cells to penetrate elastin matrices. The reduction in cath-L secretion was as a result of an up-regulation of SNAP25, a member of the t-SNARE plasma membrane complex, which is involved in Ca2+-dependent exocytosis. Furthermore, we demonstrated that proEGFcyt-mediated silencing of UCH-L1 causes the decrease in EGFR due to enhanced EGFR ubiquitination. This correlated with altered proteasomal degradation and provides a unique new mechanism on how proEGFcyt can affect cell proliferation in human thyroid cancer cells. These studies identified novel functions of human proEGF as a bidirectional signaling molecule consisting of the known extracellular EGF domain which functions as the classical ligand and activator of EGFR-mediated cell growth and the proEGF cytoplasmic domain which has the ability to suppress migration and growth of human thyroid carcinoma cells.
3

Targeting thyroid stimulating hormone receptors in radioiodine resistant dedifferentiated thyroid cancer

Boshoff, Ana Sousa Marcelino January 2012 (has links)
The most common type of thyroid cancer, differentiated thyroid cancer (DTC), is diagnosed by radioactive iodine whole body scanning (WBS) and treated with radiotherapy using iodine-131 (131I). The success of this diagnosis/treatment approach relies on the relatively selective localisation of the sodium/iodide symporter (NIS) in cells of the thyroid gland. However, in some de-differentiated thyroid cancers, NIS expression is lost. This results in the inability of WBS to stage the disease and it also decreases the effectiveness of treatment with 131I. A number of reports have shown that de-differentiated thyroid carcinomas, however, continue to express thyroid stimulating hormone receptor (TSHR). TSHR is, therefore, a potential target for the diagnosis and treatment of radioiodine resistant de-differentiated thyroid carcinoma. In this study an anti-TSHR monoclonal antibody (mAb9) and human recombinant TSH (rhTSH) were radiolabelled and evaluated for their potential use in the diagnosis and treatment of radioiodine resistant thyroid cancer. A number of radiolabelling methods and quality control experiments were initially carried out to ensure high purity radiolabelled mAb9 and rhTSH were produced. In vitro studies were conducted to assess the binding affinity of 125I-mAb9, 111In-mAb9 and 125I-rhTSH to the TSHR in thyroid cancer cell lines, TPC-1, FTC-133, and FRTL5, and in a TSHR transfected cell line, GPI. SPECT/CT animal studies were performed in mice to investigate whether 125I-mAb9, 111In-mAb9 and 125I-rhTSH bound to TSHR in the thyroid of mice in vivo. 125I-mAb9, 111In-mAb9 and 125I-rhTSH bound to GPI cells but did not bind specifically to the TSHR in FTC-133, TPC-1 and FRTL5 cells as well as to the thyroid of normal mice in vivo. Radiolabelled mAb9 and radiolabelled rhTSH are therefore unlikely to be of use in the diagnosis and treatment of radioiodine resistant de-differentiated thyroid cancer.
4

Time to surgery and thyroid cancer survival in the United States

Rosner, Jessica 09 June 2023 (has links)
Over the past several decades, the incidence of thyroid cancer in the United States has increased substantially surmounting to higher levels of concern for physicians around the nation. This concern led to a research investigation surrounding the increased risk thyroid cancer patients may face by delaying their surgeries. OBJECTIVE: We aim to evaluate the impact of a delay in surgical intervention on survival in patients with a diagnosis of papillary thyroid cancer. METHODS: This is an observational retrospective study focusing on disease specific survival using SEER-Medicare data as well as data from the National Cancer Database to analyze whether a delay in surgical intervention leads to a decrease in mortality in patients with papillary thyroid cancer. This study focuses on specific thyroid cancer association beyond that of another research paper that found delaying time to surgery does decrease overall survival as discovered by Dr. Scott Fligor in 2021. For the purposes of this study, data was accessed between the years 1999-2018. A survival analysis was performed using the Cox- hazard ratio as well as Kaplan-Meier curves. RESULTS: Preliminary results detail the fact that delaying surgeries past 180 days for patients led to decreased survival over a course of 5, 10, and 15 years as was determined by the use of Kaplan Meyer curves and the Cox hazard ratio. A positive coefficient for a Cox hazard ratio indicates a worse prognosis whereas a negative coefficient indicates the opposite. The results of this study show that increasing time to surgery increases risk of mortality for patients as the hazard ratios suggest for this research. The hazard ratio for 90 – 180 days delay for patients versus patients who underwent surgery within 0 – 90 days was 1.18 (95% confidence internal, 0.96 – 1.45). This hazard ratio is lower than that of the group that underwent surgery after 180+ days whose hazard ratio was 1.21 (95% confidence internal, 0.89 – 1.66). Since the hazard ratio for patients who delayed surgery after 180+ days is higher than the 0 – 90 days as well as the 90 – 180 days, this indicates a worse prognosis over time for patients with increased delays. CONCLUSION: Delaying surgery for thyroid cancer patients deceases their overall survival over a period of 5, 10, and 15 years. Elective or lower risk surgeries over the past 3 years have been delayed due to the Covid-19 pandemic, and thus this data was excluded for the purposes of this study. Further research should be done on the effects the pandemic had on the overall survival for patients who had to delay their surgeries due to the pandemic.
5

Complexities in the Diagnosis and Treatment of Thyroid Cancer: Discussions, Observations, Research and Public Policy

Gordon, Hannah V. 01 January 2012 (has links)
The impact of the increasing incidence of thyroid cancer presents an interesting case study in public health policy and resource allocation. During the last three decades, thyroid cancer cases have increased by more than 400%. As an illness that affects the lives of hundreds of thousands each year, the human and economic costs will be magnified in the next decade. It is estimated that approximately 13-67% of people will have thyroid nodules during their life of which approximately 5% will be malignant. The standard treatment, a thyroidectomy frequently followed by radioactive 131 iodine treatment, accordingly would seem to be a likely future event for an increasing percentage of the population. Despite the magnitude of the increase, there has been no increase in age-adjusted mortality rates. This raises the question whether treatment is effective or warranted for many of these patients. Although there is almost no reliable data on its economic impact, its prevalence makes it likely that it is becoming one of the more expensive diseases in our health care system. Despite the pressing issue of its growth, thyroid cancer is one of the least studied and least funded cancers in the United States.
6

Adequate duration and modality of follow-up for patients treated with 131 I for differentiated thyroid cancer

Adedapo, Kayode Solomon 18 November 2009 (has links)
No abstract in the thesis
7

INHIBITION MYCN- VERMITTELTER ZELLZYKLUSTRANSITION DURCH THYROID CANCER 1 (TC1) IM NEUROBLASTOM – ETABLIERUNG UND CHARAKTERISIERUNG DES TC1- ÜBEREXPRESSIONSPHÄNOTYPS IN HUMANEN SH-EP NEUROBLASTOMZELLEN UNTER DEM EINFLUSS VON MYCN

Weiher, Moritz Adrian 04 December 2015 (has links) (PDF)
Das Neuroblastom ist der dritthäufigste maligne Tumor im Kindesalter und ist für 15% der Todesfälle durch Krebs bei Kindern unter 14 Jahren verantwortlich. Viele molekularbiologische Vorgänge, die zu der heterogenen Prognose der Patienten beitragen, sind noch nicht verstanden. Als Hauptrisikomerkmal stellt sich die Amplifikation und erhöhte Expression von MYCN dar. In Vorarbeiten der Arbeitsgruppe von Prof. Christiansen zeigte MYCN Einfluss auf die Genregion von Thyroid Cancer 1 (TC1), das als neuer Marker für maligne Schilddrüsenkarzinome erkannt wurde. In der vorliegenden Arbeit wurden erste Untersuchungen zur prognostischen Bedeutung von TC1 im Neuroblastom, sowie die Charakterisierung eines TC1 Überexpressionsphänotyps humaner Neuroblastomzelllinien unter Einfluss von MYCN durchgeführt. Es wurde ein Überexpressionsvektor von TC1 in die Neuroblastomzelllinie SH-EP eingebracht, welche über ein aktivierbares MYCN- Konstrukt verfügt. Dieser neue Phänotyp wurde bezüglich der Proliferation, des Zellzyklus und der Apoptose im Vergleich zu einer Kontrollzelllinie ohne Überexpression untersucht. Eine In-silico Recherche in der Versteeg Neuroblastomdatenbank ergab eine deutlich bessere Überlebenswahrscheinlichkeit für Patientin mit hoher TC1 Expression. Es konnte gezeigt werden, dass MYCN Amplifikation und Expression in einem Panel von Neuroblastom Zelllinien nicht mit der TC1 Expression korrelieren. Die spezifische Aktivierung von MYCN führte hingegen zu einer Expressionssteigerung von TC1. Weiterhin zeigte sich, dass eine TC1 Überexpression die Proliferation hemmt, indem es die MYCN induzierte G1- S- Phasen- Transition inhibiert. TC1 zeigt antiproliferative Eigenschaften im Zellkulturmodell und stellt sich als neuer prognostisch günstiger Parameter im Neuroblastom dar.
8

Diagnóstico de lesões da tireóide pela espectroscopia de absorção no infravermelho por transformada de Fourier-FTIR / Thyroid lesions diagnosis by fourier transformed infrared absorption spectroscopy (FTIR)

Albero, Felipe Guimarães 11 December 2009 (has links)
Os nódulos de tireóide constituem patologia comum, com uma incidência entre 4- 7% na população brasileira. Embora a punção aspirativa por agulha fina (PAAF) seja um método com boa sensibilidade, a discriminação entre lesões benignas e neoplasias malignas não é possível em todos os casos, permitindo a incidência de diagnósticos falsos-positivos, o que conduz a tireoideotectomia pelo risco de carcinoma. O escopo deste estudo foi verificar se a espectroscopia de absorção no infravermelho por transformada de Fourier (FTIR) pode contribuir no diagnóstico diferencial entre neoplasias malignas e benignas de tecidos e aspirados. Amostras de PAAF, homogenatos e tecidos de nódulos de tireóide com o diagnóstico histopatológico foram obtidos e preparados para análise espectroscópica por FTIR. As punções e homogenatos foram medidas por -FTIR (entre 950 1750 cm-1, com resolução de 4 cm-1 e 120 varreduras). As amostras de tecido foram analisadas diretamente pela técnica de ATR-FTIR, com resolução de 2 cm-1, 60 varreduras, região entre 950 1750 cm-1.. Todos os espectros foram corrigidos pela linha base e normalizados pela área sob a banda das amidas (1550-1640 cm-1) de modo a minimizar as variações de homogeneidade das amostras. Os espectros foram então convertidos em segundas derivadas usando-se o filtro de Savitzk-Golay com 13 pontos na janela. A variância de Ward e distância euclidiana foram usadas para se processar a análise de clusters. As amostras de PAAF revelaram um complexo padrão espectral. Todas as amostras mostraram alguns aglomerados de células ou grande concentração de hormônios, tendo representação em algumas bandas em 1545 e 1655 cm-1. Foram também encontradas bandas em torno de 1409, 1412, 1414, 1578 and 1579 cm-1, indicando a possível presença de açúcares, DNA e ácido cítrico de produtos metabólitos. Neste estudo, foi obtida uma excelente separação entre bócio adenomatoso e neoplasias malignas para as amostras de tecido, com 100% de sensibilidade em determinado cluster, mas 67% no geral e 50% de especificidade. Nos homogenatos e aspirados este valor foi menor (76,2% de sensibilidade e 52,6% de especificidade) porque incluiu outros tipos de lesões. Para uma maior diferenciação das amostras de PAAF de padrão folicular, um maior número de amostras se faz necessário. Os resultados deste estudo sugerem que a espectroscopia FTIR pode ser útil na diferenciação de carcinomas da tiróide em amostras de tecidos. / Thyroid nodules are a common disorder, with 4-7% of incidence in the Brazilian population. Although the fine needle aspiration (FNA) is an accurate method for thyroid tumors diagnosis, the discrimination between benign and malignant neoplasm is currently not possible in some cases with high incidence of false negative diagnosis, leading to a surgical intervention due to the risk of carcinomas. The aim of this study was to verify if the Fourier Transform infrared spectroscopy (FTIR) can contribute to the diagnosis of thyroid carcinomas and goiters, using samples of tissue and aspirates. Samples of FNA, homogenates and tissues of thyroid nodules with histopathological diagnosis were obtained and prepared for FTIR spectroscopy analysis. The FNA and homogenates samples were measured by -FTIR (between 950 1750 cm-1), at a nominal resolution of 4 cm-1 and 120 scans). Tissue samples were analized directly by ATR-FTIR technique, at a resolution 2 cm-1, with 60 scans in the same region. All spectra were corrected by the baseline and normalized by amides area (1550-1640 cm-1) in order to minimize variations of sample homogeneity. Then, spectra were converted into second derivatives using the Savitzk-Golay algorithm with a 13 points window. The Ward\'s minimum variance algorithm and Euclidean distances among the points were used for cluster analysis. Some FNA samples showed complex spectral pattern. All samples showed some cell pellets and large amount of hormone, represented by the bands of 1545 and 1655 cm-1. Bands in 1409, 1412, 1414, 1578 and 1579 cm-1 were also found, indicating possible presence of sugar, DNA, citric acid or metabolic products. In this study, it was obtained an excellent separation between goiter and malign lesion for the samples of tissues, with 100% of specificity in specific cluster and 67% sensibility and 50 of specificity. In homogenate and FNA samples this sensibility and specificity were lower, because among these samples, it were included many types of thyroid lesions. To obtain a more precise diagnosis for FNA of follicular thyroid the sample size should be increased. The results of this study suggest that FTIR spectroscopy may be useful for discriminate thyroid carcinomas from goiters in tissue samples.
9

Coexistence of papillary thyroid microcarcinoma and mucosa-associated lymphoid tissue lymphoma in a context of Hashimoto’s thyroiditis

Levy Blitchtein, Saul, Plasencia Rebata, Stefany, Luna, Domingo Morales, Del Valle Mendoza, Juana 06 1900 (has links)
Papillary thyroid cancer (PTC) represents 80%-85% of thyroid cancer and its prevalence has been rising in the last decades. Primary thyroid lymphoma (PTL) accounts for 3% of extranodal lymphomas and about 5% of thyroid malignancies, having a prevalence of one or two cases per million people. Mucosa-Associated Lymphoid Tissue lymphoma represents approximately 30% of PTL. Both entities have an indolent course and a very good prognosis. Diagnosis is made by ultrasound and fine needle aspiration (FNA) or surgery specimen pathology. They have also been associated with HT, but pathogenesis and its links remains to be known. Treatment remains controversial and surgery is generally accepted in cases of disease limited to thyroid, as the present. Patients with thyroid nodules should be observed and followed. If there is an enlargement by ultrasound or clinical symptoms, FNA should be performed promptly. Patients with Hashimoto’s thyroiditis (HT) deserve additional surveillance, since this condition is associated with both PTC and PTL. In this case, the management with surgery and radioactive iodine ablation therapy was effective for both entities. Patients with thyroid nodules should be properly evaluated with ultrasound and thyroid function tests. If there is an enlargement of the neck, reported by symptoms or ultrasound, it requires further investigation. HT is associated to both PTC and PTL so if the enlargement of the nodules is on this context additional tests such as FNA should be performed. In this case, the patient was managed with surgery and radioactive iodine ablation therapy and it was effective for both entities. / Revisión por pares
10

Management Patterns and Outcomes of Differentiated Thyroid Cancer in Ontario: A Population-based Study

Tasevski, Robert 19 March 2013 (has links)
The incidence of differentiated thyroid cancer (DTC) is rising, but controversy exists in many aspects of its treatment. This study described the change in incidence of DTC in Ontario, variations in management including extent of thyroidectomy and the influence of provider volume, and the impact of these parameters on recurrence and thyroid cancer-specific death (TCSD). A population-based study identified all new cases of DTC between 1992-2007. The incidence of DTC increased dramatically (annual percentage change 7.6%). Linkage to administrative databases revealed that extent of thyroidectomy is influenced by various factors including patient gender, age, year of diagnosis, surgeon specialty, and hospital setting, but not provider volume. Total thyroidectomy is associated with a lower recurrence rate. There is a significant association between provider volume and recurrence, with lower volume surgeons having a higher recurrence risk. Extent of thyroidectomy and provider volume did not influence TCSD. Such variations in management may lead to disparities in health outcomes.

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