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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.
41

Multimarker Gene Analysis of Circulating Tumor Cells in Pancreatic Cancer Patients: A Feasibility Study

de Albuquerque, Andreia, Kubisch, Ilja, Breier, Georg, Stamminger, Gudrun, Fersis, Nikos, Eichler, Astrid, Kaul, Sepp, Stölzel, Ulrich January 2012 (has links)
Objective: The aim of this study was to develop an immunomagnetic/real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay and assess its clinical value for the molecular detection of circulating tumor cells (CTCs) in peripheral blood of pancreatic cancer patients. Methods: The presence of CTCs was evaluated in 34 pancreatic cancer patients before systemic therapy and in 40 healthy controls, through immunomagnetic enrichment, using the antibodies BM7 and VU1D9 [targeting mucin 1 and epithelial cell adhesion molecule (EpCAM), respectively], followed by real-time RT-PCR analysis of the genes KRT19, MUC1, EPCAM, CEACAM5 and BIRC5. Results: The developed assay showed high specificity, as none of the healthy controls were found to be positive for the multimarker gene panel. CTCs were detected in 47.1% of the pancreatic cancer patients before the beginning of systemic treatment. Shorter median progression-free survival (PFS) was observed for patients who had at least one detectable tumor-associated transcript, compared with patients who were CTC negative. Median PFS time was 66.0 days [95% confidence interval (CI) 44.8–87.2] for patients with baseline CTC positivity and 138.0 days (95% CI 124.1–151.9) for CTC-negative patients (p = 0.01, log-rank test). Conclusion: Our results suggest that in addition to the current prognostic methods, CTC analysis represents a potential complementary tool for prediction of outcome in pancreatic cancer patients. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
42

Multimarker Analysis of Circulating Tumor Cells in Peripheral Blood of Metastatic Breast Cancer Patients: A Step Forward in Personalized Medicine

Albuquerque, Andreia de, Kaul, Sepp, Breier, Georg, Krabisch, Petra, Fersis, Nikos January 2012 (has links)
Aim: To develop an immunomagnetic assay for the isolation of circulating tumor cells (CTCs) followed by the analysis of a multimarker panel, which will enable the characterization of these malignant cells with high accuracy. Patients and Methods: Peripheral blood (PB) was collected from 32 metastatic breast cancer patients and 42 negative controls. The antibodies BM7 and VU1D9 were used for immunomagnetic tumor cell enrichment. A real-time reverse transcription-polymerase chain reaction (RT-PCR) approach for the markers KRT19, SCGB2A2, MUC1, EPCAM, BIRC5 and ERBB2 was used for CTC detection and characterization. Results: The positivity rates for each marker were as follows: 46.9% for KRT19, 25.0% for SCGB2A2, 28.1% for MUC1, 28.1% for EPCAM, 21.9% for BIRC5, and 15.6% for ERBB2. After the creation of individualized cutoffs, the sensitivity and specificity of the combined marker gene panel increased to 56.3% and 100%, respectively. Interestingly, 27.0% of the HER2-negative tumor patients showed ERBB2 mRNA-positive CTCs. Conclusions: The described technique can be used to measure CTCs with great accuracy. The use of a multimarker panel for the characterization of CTCs may provide real-time information and be of great value in therapy monitoring. / Ziel: Entwicklung eines immunomagnetischen Verfahrens zur Isolierung zirkulierender Tumorzellen (CTCs) in Kombination mit einer molekularen Multimarkeranalyse für die hochspezifische Identifizierung maligner Zellen. Patientinnen und Methoden: Peripheres Blut (PB) von 32 Patientinnen mit metastasiertem Mammakarzinom und von 42 gesunden Kontrollen wurde für die immunomagnetische Tumorzellanreicherung mit den Antikörpern BM7 und VU1D9 genutzt. Eine Real-Time Reverse Transkription Polymerase-Kettenreaktion (RT-PCR)-Methodik mit den Markern KRT19, SCGB2A2, MUC1, EPCAM, BIRC5 und ERBB2 wurde für den CTC-Nachweis und die Tumorzellcharakterisierung entwickelt. Ergebnisse: Für die einzelnen Marker wurden die folgenden Positivitätsraten ermittelt: 46,9% für KRT19, 25,0% für SCGB2A2, 28,1% für MUC1, 28,1% für EPCAM, 21,9% für BIRC5 und 15,6% für ERBB2. Nach der Bestimmung individualisierter Cut-off-Werte ergab sich für den kombinierten Multimarkernachweis eine Sensitivität und Spezifität von 56,3% bzw. 100%. Bemerkenswert war der Befund, dass 27,0% der HER2-tumornegativen Patientinnen ERBB2-mRNA-positive CTCs aufwiesen. Schlussfolgerung: Die hier beschriebene Methodik bestimmt CTCs mit hoher Spezifität. Die molekulare Multimarkeranalyse liefert wertvolle Real-Time-Informationen für personalisierte Behandlungsmodalitäten. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
43

Laboratorní diagnostiky mikrometastáz u pacientek s karcinomem prsu / Laboratory diagnostics of micrometastases in breast cancer patients

Mikulová, Veronika January 2016 (has links)
Introduction: The presence of circulating tumor cells (CTC) in the peripheral blood has been associated with worse prognosis and early relapse in breast cancer patients. CTC determination in the peripheral blood has been considered as a liquid biopsy. The aim of this project was to analyze the presence of CTC followed by their molecular characterization with the potential use not only as a new biomarker for real-time monitoring of therapy efficacy but also as a suitable tool for patient's stratification and individualization of treatment for breast cancer. Methods: A total of 54 patients with diagnosed early breast cancer were enrolled into a prospective study. Ten millilitres of peripheral blood were sequentially collected to test for the presence and characterization of CTC during the follow-up of patients. CTC isolation and detection was performed by AdnaTest BreastCancer™ (AdnaGen AG, Germany), which is based on the detection of EpCAM, HER2 and MUC1 specific transcripts in enriched CTC- lysates. cDNA from isolated CTC has been further used for newly optimized qPCR assays for breast tumor and therapy resistance associated genes: TOP1, TOP2A, CSTD, ST6GAL, KRT19 and reference gene actin. qPCR results have been analyzed by Genex software (MultiD Analysis). Results: 195 blood samples have been...
44

Detekce minimální reziduální choroby v kostní dřeni a periferní krvi u pacientek s karcinomem prsu. / Detection of minimal residual disease in bone marrow an peripheral blood in patients with breast cancer.

Čabiňaková, Michaela January 2015 (has links)
Introduction: Simultaneous detection of disseminated tumor cells (DTCs) and circulating tumor cells (CTCs) was shown to be associated with an especially poor prognosis and increased incidence of disease-related deaths in non-metastatic breast cancer patients. We analyzed the occurance of DTCs in bone marrow and CTCs in peripheral blood in patients with primary breast cancer, we evaluated the correlation of their presence with other prognostic markers and we investigated the changes in DTCs/CTCs number at different time points during treatment. Materials and methods: Blood of 50 patients with primary breast cancer were used for immunomagnetic separation and detection of circulating tumor cells using the commercial available system the AdnaTest Breast Cancer™ (AdnaGen GmbH, Langenhagen, Germany). Bone marrow aspirates from 50 patients were analyzed for DTCs by immunocytochemistry using the pancytokeratin antibody conjugated with FITC (Monoclonal Anti-Cytokeratin antibody F3418, Sigma Aldrich, USA). Results: DTCs were identified in 30% (15/50) and CTCs in 22% (11/50) of patients. We found that DTC positivity could point to a significantly high risk of larger primary tumor size (p- value 0.011) and significantly higher risk of lymph node involvement (p- value 0.002). For CTC positivity, no such...
45

Modeling and design optimization of a microfluidic chip for isolation of rare cells

Gannavaram, Spandana 12 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Cancer is still among those diseases that prominently contribute to the numerous deaths that are caused each year. But as technology and research is reaching new zeniths in the present times, cure or early detection of cancer is possible. The detection of rare cells can help understand the origin of many diseases. The current study deals with one such technology that is used for the capture or effective separation of these rare cells called Lab-on-a-chip microchip technology. The isolation and capture of rare cells is a problem uniquely suited to microfluidic devices, in which geometries on the cellular length scale can be engineered and a wide range of chemical functionalizations can be implemented. The performance of such devices is primarily affected by the chemical interaction between the cell and the capture surface and the mechanics of cell-surface collision and adhesion. This study focuses on the fundamental adhesion and transport mechanisms in rare cell-capture microdevices, and explores modern device design strategies in a transport context. The biorheology and engineering parameters of cell adhesion are defined; chip geometries are reviewed. Transport at the microscale, cell-wall interactions that result in cell motion across streamlines, is discussed. We have concentrated majorly on the fluid dynamics design of the chip. A simplified description of the device would be to say that the chip is at micro scale. There are posts arranged on the chip such that the arrangement will lead to a higher capture of rare cells. Blood consisting of rare cells will be passed through the chip and the posts will pose as an obstruction so that the interception and capture efficiency of the rare cells increases. The captured cells can be observed by fluorescence microscopy. As compared to previous studies of using solid microposts, we will be incorporating a new concept of cylindrical shell micropost. This type of micropost consists of a solid inner core and the annulus area is covered with a forest of silicon nanopillars. Utilization of such a design helps in increasing the interception and capture efficiency and reducing the hydrodynamic resistance between the cells and the posts. Computational analysis is done for different designs of the posts. Drag on the microposts due to fluid flow has a great significance on the capture efficiency of the chip. Also, the arrangement of the posts is important to contributing to the increase in the interception efficiency. The effects of these parameters on the efficiency in junction with other factors have been studied and quantified. The study is concluded by discussing design strategies with a focus on leveraging the underlying transport phenomena to maximize device performance.
46

Isolement et caractérisation moléculaire de cellules rares circulantes individuelles : développement de nouvelles approches méthodologiques en oncologie prédictive et diagnostic prénatal / Isolation and molecular characterization of single circulating rare cells : developing innovative methods for predictive oncology and non-invasive prenatal diagnosis

Broncy, Lucile 07 November 2017 (has links)
L’objectif principal de ce projet de recherche doctorale est la mise au point d’approches méthodologiques fiables et reproductibles permettant la caractérisation génétique de cellules rares circulantes isolées par la méthode de filtration ISET® (Rarecells®, France). La première application développée consiste en la détection des mutations du gène suppresseur de tumeur VHL (Von Hippel Lindau) dans les cellules rares circulantes (CRC) uniques isolées du sang de 30 patients atteints de carcinome rénal à cellules claires (CRCC), et réalisée comparativement à l’analyse cytopathologique. L’étude génétique a également été conduite en parallèle dans les 30 tissus tumoraux correspondants. Les résultats ont mis en lumière une potentielle complémentarité de l’approche de génétique moléculaire sur cellules uniques avec l’analyse cytomorphologique de référence et suggèrent que combiner ces approches permettrait d’obtenir une plus grande sensibilité de détection des cellules cancéreuses circulantes chez les patients atteints de CRCC. Une deuxième application a consisté en le développement d’une approche innovante pour le diagnostic prénatal non-invasif des maladies génétiques récessives par analyse de cellules trophoblastiques rares collectées au niveau du col de l’utérus. Enfin, des développements supplémentaires ont permis d’optimiser les analyses de séquençage à haut débit et de les appliquer à des CRC individuelles isolées par ISET®. Cette nouvelle approche, associée à l’isolement de CRC non fixées, est en mesure de fournir des données génétiques élargies à l’exome entier pour des applications à la fois en oncologie prédictive et en diagnostic prénatal non invasif. / The aim of this doctoral research project is the development of reliable and reproducible methodological approaches enabling the genetic characterization of circulating rare cells (CRC) isolated by ISET® filtration (Rarecells®, France). The first application developed consists in detecting mutations of the VHL (Von Hippel Lindau) tumor suppressor gene in single CRC isolated from the blood of 30 patients patients with clear cell renal cell carcinoma (ccRCC), assessed according to the results obtained by cytopathological analysis. In parallel, genetic analysis of VHL mutations was conducted in the corresponding tumor tissues. Results revealed a potential complementarity of the molecular genetic approach targeted to single cells with the reference method of cytopathological analysis and suggested that combining both strategies could improve the sensitivity of circulating cancer cells’ detection in patients with ccRCC. A second application consisted in the development of an innovative approach for non-invasive prenatal diagnosis of recessive genetic diseases by analysis of rare trophoblastic cells collected from the cervix. Finally, further developments allowed to optimize high-throughput sequencing analyses and to apply them to single CRC isolated by ISET®. This approach, combined with the isolation of living CRC, enabled us to obtain broader genetic data from the whole exome and should foster innovative applications to both predictive oncology and non-invasive prenatal diagnosis.

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