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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.
561

Tumor de Leydig simulando una neoplasia germinal

Gamboa Acuña, Brenda Adriana, Guillén Zambranoa, Rayza, Lizzetti Mendozaa, Grecia 22 June 2016 (has links)
Main findings A case is presented of a Leydig cell neoplasm in a 25 year-old male patient with no classic risk factors with an atypical outcome. The tumour mass was histologically analysed and was found to have features compatible with a germ cell neoplasm. A right orchiectomy was performed, followed by chemotherapy. After treatment, pulmonary metastasis, lymph nodes, and peri-hepatic hydronephrosis were found. The patient died two months after his last hospital admission. Case hypothesis Leydig cell tumours account for 1% to 3% of all testicular tumours. They occur at any age, especially in children, and between the third and sixth decade of life. Around 90% are benign, and 10% are malignant; these latter usually occurring between 50 and 60 years old, and are associated with sizes larger than 5 cm and gynecomastia. Finally, it is difficult to predict the development of the disease based on histopathological observations. Promising future implications Although non-germ cell tumours are rare, it is important to consider them in the differential diagnosis of testicular tumours, particularly in those of non-seminoma origin. Immunohistochemistry is useful for the differentiation of testicular tumours in those cases when conventional histology shows no conclusive findings. / Hallazgos principales Reportamos un caso de neoplasia de células de Leydig en un paciente varón de 25 años, sin factores de riesgo clásicos con evolución tórpida. Se analizó la histopatología de la masa tumoral y se encontró malignidad por lo que se decide realizar orquiectomía derecha, seguida de quimioterapia. Luego del tratamiento se halla metástasis pulmonar, adenopatías perihepáticas e hidronefrosis, falleciendo 2 meses después de su último ingreso hospitalario. Hipótesis del caso El tumor de células de Leydig representa entre el 1-3% de todos los tumores testiculares. Se presentan a cualquier edad; sobre todo en la infancia y en la 3.a-6.a década de la vida. Aproximadamente el 90% son de curso benigno y el 10% son malignos, presentándose sobre todo entre la 5.a y la 6.a década de la vida, y están asociados con un tamaño > 5 cm y ginecomastia. Finalmente, es difícil predecir el comportamiento en términos histológicos. Repercusiones a futuro A pesar que los tumores de células no germinales son poco frecuentes, es importante considerarlos como diagnóstico para brindar el tratamiento óptimo y evitar resultados desafortunados.
562

Synthesis and characterization of Alendronate functionalized Poly (l-lactide) polymers for engineering bone tumor targeting nanoparticles

Sriadibhatla, Soma Sekhar January 1900 (has links)
Master of Science / Department of Chemistry / Santosh Aryal / Nanomedicine-based therapeutics have exhibited clear benefits when compared to unmodified drugs, which include improved pharmacokinetics, drug retention, targeting efficiency, and minimizes toxicity. Every year thousands of bone cancer cases are diagnosed in the United States. Moreover, development of bone metastasis occurs in over 80% to 90% of various cancers that metastasize and signals the entry of the disease into an incurable phase. Cancer in bones can cause pain, fractures, hypercalcemia, and compression of the spinal cord, due to deposits that can erode into the bone using bone-absorbing cells. Bisphosphonates are drugs that reduce the activity of bone-absorbing cells and targets overexpressed calcium. They are characterized pharmacologically to inhibit bone resorption, skeletal distribution, and renal elimination. In addition, they can target bone microenvironment and bind strongly with calcium. The goal of this thesis is to engineer targeted nanomedicine drug with the ability to spatiotemporally control therapeutics delivery to the bone. Herein we synthesized biopolymers with functional end group moieties as alendronate (a molecular member of bisphosphate), which can target overexpressed calcium ions at the vicinity of the bone lesion where bone resorption takes place. In order to achieve our goal, a ring opening polymerization of cyclic L-lactide initiated by ALE in the presence of catalytic amount of stannous octoate was conducted in an inert environment. Thus, formed polymers are characterized for their chemistry and physicochemical properties using various analytical tools. These polymers were characterized by nuclear magnetic resonance (¹H-NMR) and Fourier Transfer Infrared Spectrometer (FT-IR), which shows monomer conversion and the presence of amide and phosphate moiety. Thereafter we engineered bone-homing polymeric nanoparticles of 80nm diameter by nanoprecipitation for controlled delivery of Dox, a first line anticancer drug used in clinics. The in-vitro results show that the nanoparticles have the ability to accumulate and internalized into the bone cancer cells, deliver drugs efficiently, and are least toxic. Therefore, innovative and efficient bisphosphonate functionalized Poly-l-lactide polymers were synthesized to target bone microenvironment.
563

Steriods Protect Against Doxorubicin-Induced Cytotoxicity in Rat Cardiac Myoblastic H9C2 Cells

AL-Thabhani, Hanaa A. 01 January 2006 (has links)
Doxorubicin is one of the most potent anticancer drugs used in the treatment of wide spectrum of neoplastic diseases including breast, thyroid, colon and liver cancer. However, doxorubicin use is associated with undesirable side effects including cardiomyopathy and congestive heart failure. In the present study we have established that treatment of rat cardiac myoblasts (H9c2 cells) with doxorubicin resulted in H9c2 cell injury in a dose and time dependent manner with almost 50% cell death obtained at 5 μM of doxorubicin treatment for 24 hours. We have selected about 50% cell injury as optimum doxorubicin-induced cell injury because once this threshold is reached, cells became irreversibly injured and could not respond to protective treatment. Another potent antineoplastic drug cyclophosphamide had no cardiotoxic effects on H9c2 cells even at 35 μM concentration and up to 72 hours of treatment. Pretreatment of H9c2 cells for 24 hours with dexamethasone, cortisol, corticosterone or progesterone, significantly protect H9c2 myoblasts against subsequent 5 μM doxorubicin treatment for 24 hours in a concentration dependent manner with maximum protection obtained at 100 nM dexamethasone, 100 nM progesterone, 500 nM cortisol and 500 nM corticosterone. However, testosterone or dehydroepiandrosterone had no protective effects even at 10 μM concentration. It is concluded that both glucocorticoids and progesterone protect H9c2 cells against doxorubicin-induced cell injury.
564

Vimentin Overexpression Contributes To the Biological Properties of Metastatic Head and Neck Cancer Cells

Paccione, Rachel J. 01 January 2005 (has links)
Epithelial to mesenchymal transition occurs in the later stages of epithelial tumor progression, with cells expressing mesenchymal markers. Of these, the intermediate filament protein vimentin is frequently upregulated in metastatic carcinomas. Previously, microarray studies showed that the gene encoding vimentin is highly upregulated in metastatic HN12 cells compared to a related primary tumor cell line. In this study, we confirmed this difference using real-time quantitative PCR, western blot analysis, and immunostaining. Furthermore, EGF and TGF-β, growth factors that induce migration and invasion of HN12 cells, produced synergistic increases in vimentin expression. To assess the contribution of vimentin to the biological properties, HN12 cells were stably transfected with a plasmid that directs synthesis of vimentin shRNA. Clones expressing decreased amounts of vimentin were isolated and characterized. These cells showed significantly reduced proliferation compared to non-targeting controls. Moreover, downregulation of vimentin led to a decrease in cell motility, as well as reducing their ability to invade through a basement membrane substitute. Using transient transfection assays, vimentin promoter activity was determined in HN12 cells to define regulatory elements important for controlling vimentin upregulation in the absence or presence of EGF and TGF-β. Taken together, the data indicate that overexpression of vimentin is important for proliferation and invasion of metastatic HN12 cells, and suggest that EGF- dependent pathways target binding elements in the proximal vimentin promoter, while TGF-β is likely to act in an AP1-dependent manner. Furthermore, both growth factors appear to synergize by stimulating promoter activation through the ASE site, suggesting involvement of Stat-dependent pathways in regulation of vimentin expression in HN12 cells.
565

Functional Consequences of Matrix Metalloproteinase-1 Over-Expression in Human Gliomas

Mullet, Emily 01 January 2006 (has links)
Malignant brain tumors are among the deadliest of human cancers. Despit recent advancements in conventional therapies, glioblastomas remain incurable, largel y due to their ability to invade surrounding tissue. Matrix metalloproteinases are thought to contribute to the invaseive phenotype of human gliomas. Absent in normal brain, matrix metalloproteinase-1 (MMP-1) has been shown to be present in gliomas, and in particular in glioblastoma multiforme (GBM). To begin to examine the role of MMP-1 in these tumore, two human glioma cell lines were stably transfected with MMP-1 cDNA. Confirmation of MMP-1 over-expression in these cells was achieved through real-time PCR and Western blot analysis. The functional consequences of MMP-1 over-expression were analyzed using a collagen type-I invasion assay along with clonogenic and ATP viability assays. Data presented demonstrate that MMP-1 over-expressing cells were more invasive in both cell types and interestingly more clonogenic in on of the glioma cell lines, supporting a possible role for MMP-1 in glioma growth and invasion.
566

Markerless Lung Tumor Trajectory Estimation from Rotating Cone Beam Computed Tomography Projections

Chen, Shufei 01 January 2016 (has links)
Respiration introduces large tumor motion in the thoracic region which influences treatment outcome for lung cancer patients. Tumor motion management techniques require characterization of temporal tumor motions because tumor motion varies patient to patient, day to day and cycle to cycle. This work develops a markerless algorithm to estimate 3 dimensional (3D) lung-tumor trajectories on free breathing cone beam computed tomography (CBCT) projections, which are 2 dimensional (2D) sequential images rotating about an axis and are used to reconstruct 3D CBCT images. A gold standard tumor trajectory is required to guide the algorithm development and estimate the tumor detection accuracy for markerless tracking algorithms. However, a sufficient strategy to validate markerless tracking algorithms is lacking. A validation framework is developed based on fiducial markers. Markers are segmented and marker trajectories are xiv obtained. The displacement of the tumor to the marker is calculated and added to the segmented marker trajectory to generate reference tumor trajectory. Markerless tumor trajectory estimation (MLTM) algorithm is developed and improved to acquire tumor trajectory with clinical acceptable accuracy for locally advanced lung tumors. The development is separate into two parts. The first part considers none tumor deformation. It investigates shape and appearance of the template, moreover, a constraint method is introduced to narrow down the template matching searching region for more precise matching results. The second part is to accommodate tumor deformation near the end of the treatment. The accuracy of MLTM is calculated and compared against 4D CBCT, which is the current standard of care. In summary, a validation framework based on fiducial markers is successfully built. MLTM is successfully developed with or without the consideration of tumor deformation with promising accuracy. MLTM outperforms 4D CBCT in temporal tumor trajectory estimation.
567

Metylace regulačních oblastí HPV 16 u tonsilárních karcinomů s integrovanou a extrachromozomální formou viru / Methylation of the regulatory sequences of integrated and extrachromosomal form of HPV 16 in tonsillar tumors

Pokrývková, Barbora January 2016 (has links)
Human papillomavirus is connected with induction of cervical carcinoma as well as for some other anogenital carcinomas and subset of carcinomas of head and neck. Presence of viral E6 and E7 oncoproteins may induce cell transformation, higher load of oncoproteins is caused by the regulatory E2 protein inactivation. Aims of recent study are mechanisms of E2 protein inactivation. One option is integration of viral DNA into the host genome, which is located into the E2 gene region. Some carcinomas, where virus with extrachromosomal form was presented, were found. It appears that epigenetic changes can play the role in the development of this type of tumors, especially DNA methylation or mutation in the regulatory region of the virus. The methylation degree analysis on samples of tonsillar carcinomas with extrachromosomal and integrated form of the virus was conduced, as well as viral load of both groups was compared and the expression of E6 and E7 gene was confirmed. The results of methylation analysis showed increased methylation of the virus with integrated DNA. Mutations in the E2 protein binding sites are not revealed. The expression of the viral oncogenes were confirmed in all tumors regardless of the form of the viral genome. The mechanism of tumors induction, especially for virus with...
568

Sledování parametrů funkce štítné žlázy s ohledem na diagnostiku hypothyreozy u osob středního věku / Monitoring of thyroid function parameters with regard to the diagnosis of hypothyroidism in middle age

Bahenská, Lucie January 2013 (has links)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Bc. Lucie Bahenská Supervisor: doc. MUDr. Bohuslav Matouš, CSc. Title of diploma thesis: Monitor the parameters of thyroid function with regard to a diagnosis of hypothyroidism in middle aged There was proved an occurence of the thyroid disorders with regard to hypothyreosis in humans in the middle age in the file of 15 412 patients (5753 men, 9659 women). Simultaneously there was calculated an occurence of these disorders in the rate on men vs women. There was a file of all patients examined in VFN during the year 2012 including all patients treating at the department of endocrinology. No significant higher occurence of thyroid disorders at women was found. In the examined file there were 474 TSH analysis indicated by a practitioners like a steering control. There wasn't confirmed a higher incidence of an occurence of the thyroid disorders at women. In the file indicated by practitioners there was changed the value of TSH at 7,2% women and 9,9% men. The reason can be caused by examination the men in the risk group in comparison to women, who are examined without risk factors. There was checked the connection between hypothyreosis and diabetes mellitus and no significant higher occurence...
569

Protein expression analysis of PI3K/AKT pathway components in cells expressing INPP5K and MYO1C

Mehrbani Azar, Yashar January 2012 (has links)
In an Experimental Rat model for endometrial carcinoma (EC) a minimal region of recurrent deletion/allelic loss at the neighborhood of the Tp53 gene has been identified. A similar observation of deletion at the homologous position on human chromosome 17 unassociated with TP53 mutation has been reported in several human cancer types. Thus an important tumor suppressor activity located close to, but distinct of TP53 is suggested. Detailed molecular analysis of this candidate region in a tumor model suggested Myo1c (myosin 1C) and Inpp5k (inositol polyphosphate-5-phosphatase K), also known as Skip (skeletal muscle and kidney enriched inositol polyphosphate phosphatase), as the best candidates. These two genes are suggested to be involved in glucose metabolism through PI3K/AKT signaling and neither of them has earlier been reported as a tumor suppressor gene. The present work aimed to investigate the potential correlation of MYO1C and/or INPP5K proteins with components of PI3K/AKT signaling pathway involved in cell growth and survival. Cells were transfected with increasing amounts of MYO1C- or INPP5K- gene expression constructs and protein extracts of the cells were subjected to Western Blot analysis for 13 important components of the signaling pathway: p110β\α\δ, p85, pAkt308&473, 14-3-3β, PTEN, Akt, pErk, Erk, Ras, p4EBP1 and 4EBP1. The analysis showed dose-dependent changes in the expression levels of several of these proteins, and the observed changes for the most part were directed towards negative regulation of cell proliferation and survival. The presented data further extended the initial hypothesis for potential tumor suppressor activities of MYO1C and INPP5K proteins through PI3K/AKT pathway.
570

Analyse intégrative génomique et épigénomique de tumeurs hypophysaires à prolactine / Genomics and epigenomics integrative analysis of prolactin pituitary tumors

Roche, Magali 19 December 2013 (has links)
De nombreux modèles ont été proposés pour expliquer les mécanismes de développement et de progression tumorale, néanmoins certains aspects comme la nature et la hiérarchie des altérations primaires et secondaires sont encore discutés. Pour répondre à ces questions, nous nous sommes intéressés à la progression tumorale des tumeurs hypophysaires à prolactine humaines. Ces tumeurs d'origine monoclonale sont souvent bénignes mais certaines présentent un phénotype agressif voire malin. Afin d'identifier les mécanismes impliqués dans la progression vers le phénotype agressif nous avons utilisé des techniques de génomique intégrative (puces à ADN, séquençage haut débit) couplant l'étude du transcriptome, du génome (variation du nombre de copie chromosomique, polymorphismes) et du miRNome à partir des mêmes échantillons tumoraux. Par cette stratégie nous avons identifié et hierarchisé des altérations spécifiques des tumeurs agressives et / ou malignes dans un modèle expliquant la progression tumorale des tumeurs hypophysaires à prolactine humaines. Nous avons montré que la sous-expression des microARNs miR-183, miR-744 et miR-98 stimule la prolifération via la surexpression de leurs cibles KIAA0101, TGFB1 et E2F2 spécifiquement dans les tumeurs agressives. Ceci entraine l'acquisition d'altérations chromosomiques (perte du chromosome 11 et le gain du chromosome 1q) permettant l'activation de la dissémination métastatique. Enfin, ce travail montre que l'approche de génomique intégrative multidimensionnelle permet d'apporter de nouveaux éléments pour la caractérisation des phénotypes tumoraux, le diagnostic des tumeurs agressives et la prédiction du comportement tumoral / Numerous models have been proposed to explain the mechanisms of tumor development and progression. Nevertheless some aspects such as the nature and hierarchy of primary and secondary alterations are still debated. To answer these questions, we decided to focus on the tumoral progression of human prolactin pituitary tumors. These monoclonal tumors are usually benign but some present an aggressive or malignant phenotype. To identify the molecular events involved in tumoral progression of human PRL towards aggressive phenotype we used an integrative genomics approach (microarrays, high-throughput sequencing) coupling analysis of transcriptome, genome (variation in the number of chromosomal copy polymorphisms) and miRNome from the same human tumor. Using this strategy we identified and prioritized specific alterations of aggressive and / or malignant tumors in a model explaining the tumor progression of human prolactin pituitary tumors. We have shown that under-expression of micro-RNA miR-183, miR-744 and miR-98 stimulates proliferation through overexpression of their targets KIAA0101, TGFB1 and E2F2 specifically in aggressive tumors. This leads to the acquisition of chromosomal damage (loss of chromosome 11 and gain of chromosome 1q) which allowed the activation of the metastatic processes. Finally, this work shows that the integrative genomic multi-dimensional approach can provide new clues for the characterization of tumor phenotypes, diagnosis of aggressive tumors and prediction of tumor behavior

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