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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.
321

DESIGN, SYNTHESIS, NMR CONFORMATIONAL ANALYSIS AND DOCKING ANALYSIS OF NOVEL MULTIFUNCTIONAL MOLECULES FOR PAIN

Kumarasinghe, Isuru Ransiri January 2010 (has links)
Currently, opioids are extensively used in clinical practices in order to treat pain in patients. However, prolonged administration of opioids are not feasible due to the development of side effects especially tolerance, constipation, addiction and dependence. Our drug design is mainly aimed to reduce opioid induce side effects such as development of tolerance. The first strategy examined involves design and synthesis of peptide based single molecules that have a mu agonist and delta agonist pharmacophore in combination with a COX2 inhibitory pharmacophore. A new molecule, 3-17 having good delta agonist activity, partial COX2 inhibitory activity and weak mu agonist activity was produced. Moreover, Investigation of the bioactivities of the synthesized ligands including 3-17 in terms of their ligand receptor interactions were probed using NMR conformational analysis along with docking analysis to the respective homology modeled mu and delta opioid receptors as well as the COX2 enzyme. As a further continuation of this work, instead of peptide based mu agonist and delta agonist type pharmacophore, the highly mu selective fentanyl pharmacophore was used in combination with a pyrazole based and a pyrazolone based COX pharmacophore. Based on the SAR study and docking analysis of synthesized ligands to the homology modeled mu opioid receptor, an ideal tolerant position without significant loss of mu opioid agonist activity for fentanyl were found. The second strategy involves design and synthesis of a peptide based single molecule that has a mu agonist and a delta antagonist pharmacophore in combination with a NK1 antagonist pharmacophore. A novel molecule (4-2) containing delta antagonist activity, weak mu agonist activity and NK1 antagonist activity was identified. Its homology modeled mu opioid receptor bound conformation was compared with that of reference ligands. Docking analysis of modified 4-2 to the homology modeled mu opioid receptor revealed that it can be further modified to obtain better mu agonist activity. 4-2 showed antinociception for 45 min period of time after injection in tail flick assay. In addition to studies that were directed to avoid tolerance development due to opioid administration, peptide based potential analgesics such as biphalin was modified by introducing more peptidomimetic character in order to enhance its blood brain barrier permeability and proteolytic stability. The novel molecule (6-7) was produced in this study and its antinociception lasted for 30 min period of time after injection in the tail flick assay.
322

Prevalence of Chronic Diseases and Risk Factors for Death among Elderly Americans

Han, Guangming 14 July 2011 (has links)
The main aim of this study is to explore the effects of risk factors contributing to death in the elderly American population. To achieve this purpose, we constructed Cox proportional hazard regression models and logistic regression models with the complex survey dataset from the national Second Longitudinal Study of Aging (LSOA II) to calculate the hazard ratios (HR)/odds ratios (OR) and confidence interval (CI) of risk factors. Our results show that in addition to chronic disease conditions, many risk factors, such as demographic factors (gender and age), social factors (interaction with friends or relatives), personal health behaviors (smoking and exercise), and biomedical factors (Body mass index and emotional factors) have significant effects on death in the elderly American population. This will provide important information for elderly people to prolong lifespan regardless of whether they have chronic disease/diseases or not.
323

A STUDY OF TIES AND TIME-VARYING COVARIATES IN COX PROPORTIONAL HAZARDS MODEL

Xin, Xin 12 September 2011 (has links)
In this thesis, ties and time-varying covariates in survival analysis are investigated. There are two types of ties: ties between event times (Type 1 ties) and ties between event times and the time that discrete time-varying covariates change or "jump"(Type 2 ties). The Cox proportional hazards model is one of the most important regression models for survival analysis. Methods for including Type 1 ties and time-varying covariates in the Cox proportional hazards model are well established in previous studies, but Type 2 ties have been ignored in the literature. This thesis discusses the effect of Type 2 ties on Cox's partial likelihood, the current default method to treat Type 2 ties in statistical packages SAS and R (called Fail before Jump in this thesis), and proposes alternative methods (Random and Equally Weighted) for Type 2 ties. A simulation study as well as an analysis of data sets from real research both suggest that both Random and Equally Weighted methods perform better than the other two methods. Also the effect of the percentages of Type 1 and Type 2 ties on these methods for handling both types of ties is discussed. / NSERC
324

Mechanistic Insight Into the Role of FABP7 in Malignant Glioma

Beaulieu, Michael J. Unknown Date
No description available.
325

Dynamiques épidémiques, risques et copules

Ghassani, Mohamad, Ghassani, Mohamad 30 November 2012 (has links) (PDF)
Les modèles stochastiques classiques comportent des copules d'interactions linéaires, exprimant en général des interactions de paire. Il sera envisagé d'étendre ces modèles à des interactions non linéaires de type saturation ou de type triplet, en vue de traiter des applications réalistes, comme les diffusions épidémiques.Le but de cette thèse est d'introduire les fonctions copules en épidémiologie, et surtout d'appliquer ces fonctions sur le système de transmission de la Malaria afin de constater la dépendance entre les différents compartiments du système. Nous étudierons quelques modèles compartimentaux, qui sont une généralisation du modèle de Ross-Macdonald, en supposant que la population n'est pas constante et en prenant en compte des paramètres de transmission comme la fécondité, la mortalité et autres. Aussi, nous introduirons les classes d'âges dans certains de ces modèles compartimentaux, afin de trouver une relation entre les individus de ces classes d'âges à l'aide du modèle de Cox et des fonctions copules. Nous donnerons ensuite, deux exemples sur ces modèles : la Malaria au Mali et la peste en Europe au moyen-âge. Nous introduirons aussi les quantiles conditionnels et les fonctions copules archimédiennes, ce qui nous mènera à trouver une dépendance entre les différents compartiments des hôtes et des vecteurs.
326

Micrometastatic node-positive breast cancer: an analysis of survival outcomes and prognostic impact of the number of positive nodes and the ratio of positive to excised nodes in comparison to node-negative and macrometastatic node-positive breast cancer

Li, Karen Hui 30 April 2009 (has links)
In this study, we examined survival for patients with micrometastases greater than 0.2mm but less than 2mm (pN1a) in comparison to node-negative (pN0) and macrometastatic node-positive (pN1b) patients. Data for patients diagnosed from 1988 to 1998 with TNM pathological T1-2 stage, pN0, and pN1a-b breast cancer with no distant metastasis was provided by Dr. P. Truong from BC Cancer Agency. Results obtained from the Kaplan-Meier estimators and the multivariable Cox Proportional Hazards Model analyses suggested that micrometastatic node-positive patients had worse survival than the node-negative patients, but better survival in comparison to the macrometastatic node-positive patients. Increasing number of positive nodes and larger values of the ratio of positive to excised nodes were significantly associated with worse survival.
327

Μορφολογική εκτίμηση της συνομιλίας (cross–talk) των μεταγραφικών παραγόντων PPARγ και AP-1 στην καρκινογένεση του παχέος εντέρου

Βανδώρος, Γεράσιμος 14 February 2012 (has links)
Ο ακριβής ρόλος των μεταγραφικών παραγόντων AP-1, NF-κB και PPARγ στην καρκινογένεση του παχέος εντέρου δεν είναι πλήρως εξακριβωμένος. Είναι γνωστό ότι ο υποκινητής του γονιδίου cox-2 περιλαμβάνει περιοχές πρόσδεσης των μεταγραφικών παραγόντων AP-1 και NF-κB. ΣΚΟΠΟΣ Με σκοπό την διερεύνηση του ρόλου των AP-1, NF-κB και PPARγ στην καρκινογένεση του παχέος εντέρου, εξετάστηκε η έκφραση των c-FOS, pc-JUN (φωσφορυλιωμένος-ενεργός c-JUN), pIκB-α (φωσφορυλιωμένος IκB-α – δείκτης ενεργοποίησης του μονοπατιού του ΝF-κB), CBP (κοινός μεταγραφικός συνενεργοποιητής των AP-1, NF-κB και PPARγ), EGFR, p53, PPARγ και COX-2, τόσο στον φυσιολογικό εντερικό βλεννογόνο όσο και σε αδενοκαρκινώματα παχέος εντέρου. ΥΛΙΚΟ-ΜΕΘΟΔΟΣ Εφαρμόστηκε ανοσοϊστοχημική μεθοδολογία σε τομές μονιμοποιημένες σε ουδέτερη φορμόλη και εγκλεισμένες σε παραφίνη από 60 ασθενείς με καρκίνο παχέος εντέρου. Για κάθε ασθενή δημιουργήθηκε ένα “μοριακό προφίλ”, τόσο για τα φυσιολογικά επιθηλιακά κύτταρα όσο και για τα καρκινικά. Οι στατιστικές σχέσεις μεταξύ των μεταγραφικών παραγόντων και των γονιδίων-στόχων μελετήθηκαν με την χρήση του Spearman’s rho συντελεστή συσχετίσεως, και έγινε περαιτέρω ανάλυση και επιβεβαίωση των αποτελεσμάτων με την βοήθεια μη-παραμετρικής ανάλυσης Kruskall-Wallis. ΑΠΟΤΕΛΕΣΜΑΤΑ Ο pΙκΒ-α βρέθηκε υπερεκφρασμένος στο 81.7% των αδενοκαρκινωμάτων σε σχέση με το γειτονικό φυσιολογικό επιθήλιο και η έκφρασή του συσχετιζόταν θετικά με την COX-2 (Spearman’s rho = 0.513, P < 0.001). H έκφραση του PPARγ βρέθηκε ελαττωμένη στο 77.3% των αδενοκαρκινωμάτων και παρουσίαζε αρνητική συσχέτιση με την έκφραση της COX-2 (Spearman’s rho = -0.412, P < 0.001) και του pIκB-α (Spearman’s rho = -0.444, P < 0.001). Ο CBP βρέθηκε υπερεκφρασμένος στο 50% των αδενοκαρκινωμάτων σε σχέση με το γειτονικό φυσιολογικό επιθήλιο και η έκφρασή του συσχετιζόταν θετικά με την COX-2 (Spearman’s rho = 0.461, P < 0.001). Οι EGFR και pc-JUN βρέθηκαν υπερεκφρασμένοι στο 41.7% και στο 43.3% των αδενοκαρκινωμάτων, αντίστοιχα, σε σχέση με το γειτονικό φυσιολογικό επιθήλιο και η έκφρασή τους συσχετιζόταν θετικά με την COX-2 (Spearman’s rho = 0.444, P < 0.001 και Spearman’s rho = 0.431, P < 0.001, αντίστοιχα). Επιπλέον, η έκφραση του p53 εμφάνιζε θετική συσχέτιση με την έκφραση της COX-2 (Spearman’s rho = 0.435, P = 0.004). ΣΥΜΠΕΡΑΣΜΑΤΑ Η ανάλυση των παραπάνω αποτελεσμάτων οδηγεί στο συμπέρασμα ότι η επαγωγή του μονοπατιού EGFR–MAPK–AP-1 και του μονοπατιού του ΝF-κB, καθώς και η ελάττωση της έκφρασης του PPARγ, είναι σημαντικά γεγονότα κατά την διάρκεια της καρκινογένεσης του παχέος εντέρου. Οι σχέσεις μεταξύ των μεταγραφικών παραγόντων AP-1, NF-κB, PPARγ και της COX-2 οδήγησαν στην δημιουργία ενός μοριακού μοντέλου, το οποίο εξηγεί την υπερέκφραση της COX-2 στα αδενοκαρκινώματα του παχέος εντέρου. Η κλινική σημασία αυτού του μοντέλου για την χημειοπροφύλαξη και την θεραπεία του καρκίνου παχέος εντέρου συζητείται διεξοδικά. / The exact role of AP-1, NF-κB and PPARγ in the development of colon cancer remains to be elucidated. Cox-2 promoter contains transcriptional regulatory elements for various transcription factors including AP-1 and NF-κB. OBJECTIVE The present study evaluated the expression of c-FOS, pc-JUN (phosphorylated-active c-JUN), pIκB-α (phosphorylated IκB-α, a signaling intermediate of the NF-κB pathway), CBP (a known AP-1, NF-κB and PPARγ transcriptional coactivator), EGFR, p53, PPARγ and COX-2 in normal colonic epithelial cells and colon adenocarcinoma cells. METHOD Immunohistochemical methodology was performed on formalin-fixed, paraffin-embedded sections from 60 patients with colon adenocarcinomas. A “molecular profile” was created for each patient both for normal colonic epithelial cells and colon adenocarcinoma cells. Relationships between transcription factors and downstream molecular targets were evaluated by Spearman’s rho correlation coefficient and all results were further validated by nonparametric Kruskall-Wallis test. RESULTS pIκB-α was overexpressed in 81.7% of adenocarcinomas as compared to adjacent normal colon and correlated positively with COX-2 (Spearman’s rho = 0.513, P < 0.001). PPARγ was down-regulated in 77.3% of the adenocarcinomas and correlated inversely with COX-2 (Spearman’s rho = -0.412, P = 0.001) and pIκB-α (Spearman’s rho = -0.444, P < 0.001). CBP was induced in 50% of the cases and its expression correlated positively with COX-2 (Spearman’s rho = 0.461, P < 0.001). Induction of EGFR and pc-JUN was detected in 41.7% and 43.3% of the cases, respectively, and their expression correlated positively with COX-2 (Spearman’s rho = 0.444, P < 0.001 and Spearman’s rho = 0.431, P < 0.001, respectively). Moreover, p53 expression correlated positively with COX-2 (Spearman’s rho = 0.435, P = 0.004). CONCLUSIONS The results of this study indicate that activation of the EGFR–MAPK–AP-1 and NF-κB pathways as well as down-regulation of PPARγ expression are important events in colon carcinogenesis. The correlations between AP-1, NF-κB, PPARγ and COX-2 lead to the proposal of a dynamic molecular model that explains COX-2 induction in colon adenocarcinomas. The clinical implications of this model in chemoprevention and treatment of colorectal cancer are thoroughly discussed.
328

EL Haiku en la poesía del Javier Sologuren y Alfonso Cisneros Cox

Belaúnde Degregori, Alonso 20 February 2018 (has links)
El presente trabajo analiza la aproximación al haiku de Javier Sologuren y Alfonso Cisneros Cox en el marco del creciente interés por este género a nivel latinoamericano. El análisis se centra en la comparación de los haikus con el modelo clásico japonés, tal como lo practicó Matsuo Bashō, siguiendo las teorías de los estudiosos Keene, Rodríguez Izquierdo, Rubio, Blyth y Haya Segovia. El haiku es valorado y ponderado como una expresión poética orientada a evocar un instante de experiencia en la naturaleza, logrando despertar el asombro ante la maravilla de la existencia. Los resultados del trabajo revelan la íntima afinidad de ambos poetas con el género, las modalidades de apropiación que practicaron, la priorización de ciertos aspectos estilísticos y espirituales en su comprensión del haiku, la innovación en los recursos para lograrlo y la singularidad de sus creaciones, basada en la mezcla auténtica del género con sus propias poéticas. La principal conclusión que puede desprenderse de este trabajo es que los autores asimilaron este género poético para dar forma y expresión a su particular sensibilidad e integrarlo a la tradición poética peruana. / Tesis
329

Correlação da ciclooxigenase-2 com Ki-67, P53 e Caspase-3 nas neoplasias de mama de cadela

Nardi, Andrigo Barboza de [UNESP] 23 February 2007 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-02-23Bitstream added on 2014-06-13T18:41:47Z : No. of bitstreams: 1 denardi_ab_dr_jabo.pdf: 758766 bytes, checksum: efc4e6ede867b7e7930b46b41a712f2f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Tendo em vista a relação da ciclooxigenase-2 (COX-2) com a progressão do câncer, este trabalho teve como objetivo investigar a expressão da atividade desta enzima com a imunorreativadade do Ki-67 , P53 e Caspase-3 no diagnóstico e prognóstico de neoplasias mamárias em cadelas. Para a realização deste estudo foram selecionadas 60 amostras de tumores mamários de cadelas. As amostras foram divididas em seis grupos, com 10 tumores em cada grupo, de acordo com a classificação histopatológica. Nos grupos adenoma, carcinoma com prognóstico bom e carcinoma com prognóstico ruim a seleção dos casos se deu pela classificação histológica e evolução clínica do tumor. Os outros 30 tumores foram representados por 10 amostras de carcinoma primário metastático, 10 de metástase pulmonar e 10 de carcinoma inflamatório. A avaliação da expressão da COX-2 (Dako, CX-294), Ki67 (Dako, M7240), P53 (Novocastra, CM1), Caspase-3 (Neomarkers, Asp175) foi conduzida por imunoistoquímica, utilizando-se a técnica de estreptoavidina-biotinaperoxidase. Em relação aos resultados houve correlação da expressão da COX-2 com o índice de proliferação celular Ki-67 no grupo dos adenomas, metástases pulmonares e carcinomas inflamatórios (P<O,05). Em todos os grupos estudados a COX-2 apresentou correlação com a proteína P53 (P<0,01). Observou-se correlação da expressão da ciclooxigenase-2 com a Caspase-3 no grupo dos carcinomas primários metastáticos e nas metástases pulmonares (P<0,05). A expressão da ciclooxigenase-2 variou de acordo com a agressividade das neoplasias mamárias nos casos de adenoma, carcinoma metastático e carcinoma não metastáticos (P<O,05). A sobrevida das pacientes com neoplasias mamária no pós-operatório está ligada à expressão da COX-2, no grupo dos adenomas, carcinoma com prognóstico bom e carcinoma com prognóstico ruim (P<O,01). / Considering the relationship between cyclooxygenase-2 (COX-2) with the cancer evolution, this study aimed to detect the expression of this enzyme with the immunoreactive of Ki-67, P53 and Caspase-3 in the diagnosis and prognostic of mammary neoplasms in bitches. Sixty mammary tumors samples were selected for the accomplishment of this study. The samples were divided into six groups, contenting 10 tumors in each group, in accordance to histopathology classification. In adenoma, good prognosis carcinoma and poor prognosis carcinoma groups the criteria for selection was made by histology classification and clinical tumor evolution. The others 30 tumors samples were represented by 10 samples of metastatic primary carcinoma, 10 of pulmonary metastases, and 10 of inflammatory carcinoma. The evaluation of the COX-2 (Dako, CX-294), Ki-67 (Dako, M7240), P53 (Novocastra, CM1), Caspase-3 (Neomarkers, Asp175) expression was achieved by immunohistochemistry, by means of streptavidine-biotine-peroxidase. About the results a positive correlation between COX-2 and the cellular proliferation index Ki-67 was found in the adenomas, pulmonary metastases, and inflammatory carcinomas groups (P<0,05). In ali studied groups the COX-2 presented correlation with P53 protein (P<O,01). There was correlation of cyclooxygenase-2 with caspase-3 in the primary metastatic carcinoma and in the pulmonary metastases group (P<0,05). The cyclooxygenase-2 expression varied in accordance with aggressiveness of mammary neoplasms in cases such adenoma, metastatic carcinoma, and non metastatic carcinoma (P<0,05). The post operative survival rate of patients with mammary neoplasms was linked to COX-2 expression in the adenomas, good prognosis carcinoma and poor prognosis carcinoma groups (P<O,01).
330

Modelagem de dados de sobrevivência via modelo de risco logístico generalizado

Cremasco, Caroline Pires 30 March 2005 (has links)
Made available in DSpace on 2016-06-02T20:06:00Z (GMT). No. of bitstreams: 1 1808.pdf: 656634 bytes, checksum: 192e4ddfee2e11f95105db3b95487ac1 (MD5) Previous issue date: 2005-03-30 / Universidade Federal de Minas Gerais / The modeling of data of survival with the presence of covariáveis by means of the risk function has been each used time more had the easiness of interpretation One of the examples most important of risk models is the model of proportional risks considered by Cox (1972). However, this model assumes the proportionality enters the risk functions in diLerent levels of the covariáveis. To accomodate situations where the model of proportional risks is not adjusted, some types of notproportional models are being developed, as the model of sped up imperfection, considered for Prentice (1978), the model of hybrid risk of Etezadi-Amoli and Ciampi (1987) and the generalized models of hybrid risk of Louzada-Neto (1997 and 1999). In this work we explore an one new family parametric of model of dependent not-proportional risk of the time (McKenzie, 1999). This model is based on the generalization of the usual logistic function and is motivated, in part, for the necessity of if considering the eLect of the time in the modeling, and, in part, for the preference in if considering a parametric structure for the risk function. Some inferenciais procedures related this new family of models are presented.The modeling of data of survival with the presence of covariáveis by means of the risk function has been each used time more had the easiness of interpretation One of the examples most important of risk models is the model of proportional risks considered by Cox (1972). However, this model assumes the proportionality enters the risk functions in diLerent levels of the covariáveis. To accomodate situations where the model of proportional risks is not adjusted, some types of notproportional models are being developed, as the model of sped up imperfection, considered for Prentice (1978), the model of hybrid risk of Etezadi-Amoli and Ciampi (1987) and the generalized models of hybrid risk of Louzada-Neto (1997 and 1999). In this work we explore an one new family parametric of model of dependent not-proportional risk of the time (McKenzie, 1999). This model is based on the generalization of the usual logistic function and is motivated, in part, for the necessity of if considering the eLect of the time in the modeling, and, in part, for the preference in if considering a parametric structure for the risk function. Some inferenciais procedures related this new family of models are presented. / A modelagem de dados de sobrevivência com a presença de covariáveis por meio da função de risco tem sido cada vez mais utilizada devido a facilidade de interpretação Um dos exemplos mais importantes de modelos de risco é o modelo de riscos proporcionais proposto por Cox (1972). No entanto, este modelo supõe a proporcionalidade entre as funções de risco para duas ou mais covariáveis. Para acomodar situações em que o modelo de riscos proporcionais não é adequado, vários tipos de modelos não-proporcionais estão sendo desenvolvidos, como o modelo de falha acelerada, proposto por Prentice (1978), o modelo de risco híbrido de Etezadi-Amoli e Ciampi (1987) e os modelos de risco híbrido generalizados de Louzada-Neto (1997 e 1999). Neste trabalho exploramos um uma nova família paramétrica de modelo de risco não-proporcional dependente do tempo (McKenzie, 1999). Este modelo é baseado na generalização da função logística usual e é motivado, em parte, pela necessidade de se considerar o efeito do tempo na modelagem, e, em parte, pela preferência em se considerar uma estrutura paramétrica para a função de risco. Vários procedimentos inferenciais relacionados a esta nova família de modelos são apresentados.

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