• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 598
  • 148
  • 145
  • 49
  • 40
  • 37
  • 21
  • 14
  • 13
  • 10
  • 8
  • 7
  • 7
  • 5
  • 2
  • Tagged with
  • 1301
  • 1301
  • 144
  • 109
  • 108
  • 107
  • 105
  • 91
  • 90
  • 87
  • 84
  • 83
  • 82
  • 74
  • 71
  • 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.
921

Padrão alimentar, perfil antropométrico e lipídico em uma amostra de indivíduos com e sem câncer de próstata ou hiperplasia prostática benigna

Santos, Jacqueline Schaurich dos January 2007 (has links)
Patologias prostáticas como a Hiperplasia Prostática Benigna (HPB) e o Câncer de próstata (CaP) apresentam alta incidência, morbidade e mortalidade em indivíduos a partir de 40-50 anos. Fatores ambientais e nutricionais são possíveis fatores envolvidos no desenvolvimento destas doenças. Este trabalho tem por objetivo avaliar o padrão alimentar, perfil antropométrico e perfil lipídico em homens com e sem HPB e CaP e verificar se existe associação entre as variáveis consideradas e a presença de HPB ou CaP na amostra estudada. Foram entrevistados pacientes provenientes do ambulatório de Urologia do Hospital de Clínicas de Porto Alegre (pelo médico da equipe) e preenchida ficha para coleta de dados pessoais e demográficos, história médica e familiar, idade, estágio e grau do tumor, volume da próstata e valor do PSA na época do diagnóstico. Após, os pacientes foram encaminhados à nutricionista para avaliação nutricional (peso, altura, dobras cutâneas, relação cintura/quadril e Recordatório de 24h). O consumo alimentar foi avaliado pelo Recordatório de 24h e analisado pelo programa de apoio à nutrição da Escola Paulista de Medicina – EPM (DIS-EPM, versão 1.5, 2002, UNIFESP). Os pacientes foram orientados a procurar o laboratório de análises clínicas do mesmo hospital para coletar uma amostra sangüínea para dosagem sérica de testosterona total, colesterol total, colesterol HDL e triglicerídeos. O IMC e a circunferência da cintura não apresentaram diferença estatística entre os grupos avaliados. O grupo HPB apresentou consumo menor (p<0,05) de calorias e carboidrato (1875 ± 635 Kcal/dia e 253 ± 105 g/dia) quando comparado ao grupo CaP (2017 ± 476 e 283 ± 75) e ao grupo controle(2179 ± 565 e 302 ± 91). O consumo de fibra alimentar (g/dia) foi significativamente menor (p=0,01) nos grupos HPB (27 ± 12) e CaP (28 ± 10) em relação ao grupo controle (34 ± 15). O consumo aumentado de fibras parece estar relacionado a menor incidência de HPB e CaP. O consumo de calorias e demais nutrientes, o perfil antropométrico e o perfil lipídico não demonstraram relação com estas doenças. / Prostatic pathologies such as Benign Prostatic Hyperplasia (BPH) and Prostate Cancer (PCa) present high incidence, morbidity and mortality among individuals at the age of 40-50 years. Environmental and nutritional factors seem to be involved in the development of these diseases. The objective of the present study is to assess the alimentary pattern, anthropometric and lipid profiles in men with and without BPH and PCa and to verify whether there exists an association among the considered variables and the presence of BPH or PCa in the studied individuals. Urology outpatients from Hospital de Clínicas de Porto Alegre were interviewed by a physician who collected personal and demographic data, medical and familiar history, age, stage and degree of tumor, prostate volume and PSA value at diagnosis. Patients were directed to a nutritionist for nutritional evaluation (weight, height, skin folds, waist/hip ratio and 24-hours recall). Alimentary intake was assessed by 24-hours recall and analyzed by the nutrition support program of Escola Paulista de Medicina – EPM (DIS-EPM, version 1.5, 2002, UNIFESP). Patients were asked to return to the clinical analysis laboratory at the same hospital the following week, in order to collect another blood sample to dose serum total testosterone, total cholesterol, HDL cholesterol and triglycerides. Body Mass Index and waist circumference did not show statistical difference among the assessed groups. The BPH group presented with lower intake (p<0.05) of calories and carbohydrate (1875 ± 635 Kcal/day and 253 ± 105 g/day) when compared tothe PCa group (2017 ± 476 and 283 ± 75) and the control group (2179 ± 565 and 302 ± 91). Fiber intake (g/day) was significantly lower (p=0.01) on BPH (27 ± 12) and PCa groups (28 ± 10) when compared to control group (34 ± 15). Higher intake of fibers seems to be related to lower BPH and PCa incidence. Calories and other nutrients intake, anthropometric profile and lipid profile did not show relation to these diseases.
922

Influence of Histone Deacetylase Inhibitors on Polymer Mediated Transgene Delivery

January 2012 (has links)
abstract: The effects of specific histone deacetylase inhibitors (HDACi) on transgene expression in combination with a novel polymer as a delivery vehicle are investigated in this research. Polymer vectors, although safer than viruses, are notorious for low levels of gene expression. In this investigation, the use of an emerging chemotherapeutic anti-cancer drug molecule, HDACi, was used to enhance the polymer-mediated gene expression. HDACi are capable of inhibiting deacetylation activities of histones and other non-histone proteins in the cytoplasm and nucleus, as well as increase transcriptional activities necessary for gene expression. In a prior study, a parallel synthesis and screening of polymers yielded a lead cationic polymer with high DNA-binding properties, and even more attractive, high transgene expressions. Previous studies showed the use of this polymer in conjunction with cytoplasmic HDACi significantly enhanced gene expression in PC3-PSMA prostate cancer cells. This led to the basis for the investigation presented in this thesis, but to use nuclear HDACi to potentially achieve similar results. The HDACi, HDACi_A, was a previously discovered lead drug that had potential to significantly enhance luciferase expression in PC3-PSMA cells. The results of this study found that the 20:1 polymer:plasmid DNA weight ratio was effective with 1 uM and 2 uM HDACI_A concentrations, showing up to a 9-fold enhancement. This enhancement suggested that HDACi_A was effectively aiding transfection. While not an astounding enhancement, it is still interesting enough to investigate further. Cell viabilities need to be determined to supplement the results. / Dissertation/Thesis / M.S. Bioengineering 2012
923

Correlação entre níveis séricos de PSA e estimativa de volume tumoral em fragmentos de biópsia de próstata em pacientes portadores de adenocarcinoma da próstata

Toniazzo, Gustavo Piazza January 2005 (has links)
Objetivo: Determinar a correlação entre os níveis de PSA, escore Gleason e a estimativa de volume tumoral em fragmentos de biópsia de próstata em pacientes portadores de CaP. Material e Métodos: No período de 26 de abril a 15 de setembro de 2000 foram avaliados 64 pacientes submetidos à dosagem do PSA sérico e com biópsia transretal da próstata compatível com carcinoma. Os fragmentos biopsiados foram analisados quanto ao diagnóstico anatomo-patológico, graduação histológica pelo sistema Gleason e estimativa de volume tumoral através da determinação da proporção de carcinoma nos fragmentos obtidos na biópsia e medida do maior eixo tumoral. Resultados: Este estudo demonstrou a associação positiva entre estimativa de volume tumoral e níveis séricos de PSA. Entre as medidas de volume tumoral a correlação foi de maior magnitude quando se considera a proporção objetiva de carcinoma na amostra. Em relação ao escore Gleason, foi demonstrada associação significativa com níveis séricos de PSA (p<0,01) e com as medidas de volume tumoral (p<0,05). Conclusão:Existe correlação entre níveis séricos de PSA, escore Gleason e estimativa de volume tumoral em fragmentos de biópsia da próstata de pacientes com adenocarcinoma da próstata, porém o impacto dessa associação na determinação prognóstica desses pacientes permanece indeterminada. / Purpose: To determine the correlation between serum prostate specific antigen (PSA) levels, Gleason score and tumor volume in prostate needle biopsy cores in patients with prostate cancer. Materials and Methods: A total of 64 patients who underwent prostate biopsy between april 26th and September 15th 2000 had the histologic diagnosis of prostate cancer. Prostate needle biopsy specimens where examined for histologic diagnosis, Gleason score and tumor volume measure through the determination of the cancer ratio in the biopsy cores and by the linear measurement of the biggest tumor axle . Serum PSA levels obtained previously to the biopsy were also determined. Results: We found a positive correlation between tumor volume estimative and PSA serum levels. Considering the tumor volume measures, the cancer ratio in the biopsy cores was the independt measure wich had the strongest correlation. Considering Gleason score, a significant association with PSA serum levels was demonstrated (p<0,01) as well when associated to tumor volume measures, Gleason (p<0,05). Conclusions: There is correlation between PSA serum levels, Gleason score and tumor volume measures in prostate needle biopsy cores in men with prostate cancer, however the impact of this association in the prognostic determination of these patients remains unclear.
924

Vyhledávání nových biomarkerů vhodných pro screening a časnou diagnostiku nádorových onemocnění / Search for new biomarkers for screening and early diagnosis of cancer

KALČÍKOVÁ, Kateřina January 2015 (has links)
Thesis on the topic "Search of New biomakers suitable for screening and early diagnostics of cancer" is dedicated to the issue of cancer, a cancer of the breast, prostate, ovarian and after the new findings out as melanom determination of tumor markers and their implications for clinical practice. Their aim is skouted up biomaker suitable for screening and early diagnostics of carcinoma( cancer ) of the breast, ovarian, prostate and malignant melanoma with utilization of various kinds of immunoassay. The theoretical part gives a brief and comprehensive overview of the epidemiology of selected tumors and tumor markers used and their qualities. In the methodological part are given principles applied iminoanalytics methods a list of the statistical methods and a detailed description of the groups of patients. Results section contains tables with results of biomarkers diveded by sort of avalueted tumors. In the discussion are then analyzed facts that follow from the results. It discussed the process and actualy status of searching convenients biomekers and their combinations that can distinguish a population of benign tumors of the population with malignant tumors and markers which are able to distinguish healthy population from the population with malignant tumors of the breast, ovary, prostate and melanoma. This work may serve as a source of knowledge and results to continue in search of such marker that could be used for screening and early diagnosis of cancer and so to improve the prevention of these illneses in the population.
925

Estudo de polimorfismos dos genes KIR e HLA em pacientes com câncer de próstata

Silva, Pamela Portela da January 2011 (has links)
O câncer de próstata é o segundo câncer mais comum entre homens, uma vez que tanto a incidência como a mortalidade aumentam exponencialmente após a idade de 50 anos. As células Natural Killer (NK) fazem parte do sistema imune inato e reconhecem moléculas de HLA de classe I na célula alvo, através de seus receptores de membrana, chamados killer immunoglobulin-like-receptors (KIR). O objetivo desse estudo foi avaliar a associação entre os genes KIR e HLA em pacientes com câncer de próstata e grupo controle. Genotipamos 200 pacientes com diagnóstico de câncer de próstata e 185 pacientes saudáveis para os genes KIR e HLA classe I por PCR-SSP. Quando comparados os grupos, não foram encontradas diferenças significativas para HLA-C do grupo 1 e do grupo 2, HLA-Bw4, HLA-A3 e A11. Nenhuma diferença foi observada na frequência dos genes KIR nos pacientes com câncer de próstata e nos controles. Esses resultados sugerem que não há potencial papel para o sistema dos genes KIR no câncer de próstata. / Prostate cancer is the second most common cancer among men, since both incidence and mortality exponentially increases in men over fifty years of age. Natural killer cells (NK) are part of the innate immune system recognizing class I HLA molecules on target cells through their membrane receptors, called killer immunoglobulin-like receptors (KIR). The aim of our study was to evaluate the association between the KIR genes and HLA alleles in patients with prostate cancer and healthy controls. Two hundred prostate cancer patients and 185 healthy controls were typed for HLA class I and KIR genes by PCR-SSP. When both groups were compared, no significant differences were found for HLA-C group 1 and group 2, HLA-Bw4, HLA-A3 and A11. No difference was seen either in KIR frequency between patients with prostate cancer and controls. In conclusion, our data suggests no potential role for the KIR gene system in prostate cancer.
926

Influência dos genes CCR2 e CCR5 em hiperplasia e câncer de próstata

Zambra, Francis Maria Báo January 2012 (has links)
A hiperplasia prostática benigna (HPB) e o câncer de próstata (CaP) são duas condições crônicas muito comuns em homens com idade avançada e têm sido relacionadas a processos inflamatórios. As quimiocinas são reconhecidas como mediadores críticos da resposta inflamatória por regular a migração das células imunológicas através da ativação de receptores de quimiocinas na superfície destas células. As quimiocinas estão relacionadas à patogênese tumoral, embora não seja claro de que modo afetam a progressão tumoral humana. O objetivo desse estudo foi investigar a associação de dois polimorfismos de receptores de quimiocinas, CCR2-64I e CCR5-delta32, com HPB e CaP. Neste trabalho foram genotipadas 385 amostras de DNA genômico de homens do sul do Brasil, predominantemente euro-descendentes, incluindo 130 casos de HPB, 136 casos de CaP e 119 indivíduos controle saudáveis. Para o polimorfismo CCR2-64I a genotipagem foi realizada por PCR-RFLP e para o CCR5-delta32 foi por PCR convencional. As frequências alélicas do CCR2-64I foram 14,0%; 15,8% e 11,1% nos grupos controle, HPB e CaP, respectivamente; enquanto as do CCR5-delta32 foram 5,1%; 7,1% e 6,2%, respectivamente. A mediana referente aos níveis de PSA foi de 0,79; 1,45 e 6,91 ng/mL nos grupos controle, HPB e CaP, respectivamente; diferindo significativamente entre estes (todos p<0,001). A mediana do volume da próstata foi 20,00 cm3 no grupo controle, portanto, menor que dos grupos HPB (35,35 cm3) e CaP (35,80 cm3) (ambos p<0,001); no entanto, não foi observada diferença entre pacientes com HPB e CaP (p=0,172). Algo interessante observado foi CCR2-64I como um fator protetor para CaP quando comparado com HPB (OR=0,550; IC95%=0,311–0,975), mas não quando comparado com o grupo controle (p=0,448). Não foi observada associação do CCR2-64I com os estados clinicopatológicos do CaP (estadiamento tumoral e escore de Gleason) (todos p≥0,308). Não foi observada associação significativa da variante CCR5-delta32 com HPB ou CaP (todos p≥0,072), ou com os estados clinicopatológicos do CaP (todos p≥0,253). Assim, nossos dados sugerem a influência da variante CCR2-64I, observada como fator protetor para CaP quando comparada com HPB, no desenvolvimento do câncer de próstata. / Benign prostatic hyperplasia (BPH) and prostate cancer (PCa) are two chronic conditions very common in aged men and have been related to inflammatory process. Chemokines are recognized as critical mediators of inflammatory responses by regulating the migration of immune cells through the activation of chemokine receptors on the surface of these cells. Chemokines are implicated in tumor pathogenesis, although it is not clear how it affects human tumor progression. The aim of this study was to investigate the association of two chemokine receptor gene polymorphisms, CCR2-64I and CCR5-delta32, with BPH and PCa. In this study were genotyped 385 genomic DNA samples from southernmost Brazilian men, predominantly euro-descendants, including 130 BPH, 136 PCa and 119 healthy control subjects. To CCR2-64I polymorphism the genotyping was performed by PCR-RFLP and to CCR5-delta32 by conventional PCR. The allele frequencies of CCR2-64I were 14.0%, 15.8% and 11.1% in control, BPH and PCa, respectively; while of CCR5-delta32 were 5.1%, 7.1% and 6.2%, respectively. Median of serum PSA levels were 0.79, 1.45 and 6.91 ng/mL in control, BPH and PCa group, respectively (all p<0.001). The prostate volume median was 20.00 cm3 in the control group, thus, lower than BPH (35.35 cm3) and PCa (35.80 cm3) group (both p<0.001), nevertheless no difference was observed between BPH and PCa patients (p=0.172). Interestingly, CCR2-64I was detected as a protective factor to PCa when compared with BPH (OR=0.550; 95%CI=0.311–0.975), but not when compared with control group (p=0.448). No significant associations of the CCR2-64I were observed with PCa clinicopathologic states (tumor stage and Gleason score) (all p≥0.308). No significant associations of the CCR5-delta32 variant were observed with BPH or PCa (all p≥0.072), or with PCa clinicopathologic status (all p≥0.253). Thus, our data suggest a influence of the CCR2-64I variant, that was observed as a protective factor in PCa when compared with BPH, in prostate cancer development.
927

Análise de imagens da próstata baseada em técnicas não lineares

Rezende Junior, Ricardo Agostinho de January 2015 (has links)
Orientador: Prof. Dr. Marcelo Zanchetta do Nascimento / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia da Informação, 2015. / O câncer de próstata é o segundo que provoca o maior número de vítimas fatais entre os homens, atingindo principalmente a população mundial com idades superiores a 60 anos. Entre os métodos empregados para o diagnóstico médico estão os exames clínicos, laboratoriais e o diagnóstico por imagem, o que pode indicar a necessidade da biópsia da próstata. As biópsias são avaliadas por especialistas para auxiliar na conduta mais adequada de tratamento, desta forma o estudo por imagem histológica é realizado e se destaca como um dos métodos utilizados devido a facilidade de diagnosticar a doença. Porém, ainda existem problemas que precisam ser solucionados para reduzir o número de falsos positivos. Este trabalho apresenta um conjunto de técnicas para identificar e quantificar as regiões de interesse em imagens histológicas da próstata. As análises foram realizadas com dimensão fractal de imagens coloridas e classificadas com SVM com os kernels linear, polinomial e RBF. As regiões de interesses foram segmentadas em núcleos da célula cuboide, lúmens glandulares e tecido estromal e aplicado o cálculo da dimensão fractal. A avaliação de desempenho foi baseada na área sob a curva ROC (AUC) e pela acurácia. Os resultados obtidos com essas ferramentas mostram que o grupo de imagens segmentadas por estroma com magnificação de 100x obtiveram melhores resultados de classificação, obtendo valores de AUC de 92,21% e 86,77% de acurácia para os grupos de tecido normal versus tecido tumoral, obteve 73,53% de acurácia para o grupo tecido normal versus tecido hiperplásico e de 80,00% para o grupo de tecido hiperplásico versus tecido tumoral. O método proposto quantificou tecidos histológicos da próstata com descritores baseados em técnicas não lineares multi-escala. O uso de informações dos canais de cores em conjunto com a segmentação das estruturas foi mais relevante para um sistema de apoio ao diagnóstico. / Prostate cancer is the second type of cancer that causes more deaths between men. It affects mainly the population over the age of 60. Laboratory exams and diagnostic imaging are among the methods used for medical diagnosis, which may indicate the need for a prostrate biopsy. Biopsies are evaluated by experts in order to indicate the most appropriate treatment strategy. Hence, the study of histological images stands out as one of the most used methods as it allows an easier diagnosis. However, there are still problems that need to be addressed to reduce the number of false positives. This work presents a set of techniques to identify and quantify regions of interest in histological images of the prostate. Color and greyscale images were analysed using fractal dimension then classified in SVM with linear, polynomial and RBF kernels. Regions of interest were segmented in basal cell cuboid, glandular lumens and stromal tissue and then a fractal dimension was applied. Performance evaluation was based on the area under the ROC curve(AUC) and accuracy. The results obtained by applying these tools show that images segmented by stroma with a magnification of 100x had better classification results, achieving AUC values of 92.21% and 86.77% accuracy for the normal tissue groups versus tumor tissue. Also, in this group of images a level of accuracy of 73.53% for hyperplastic tissue versus normal tissue and 80.00% for hyperplastic tissue versus tumor tissue. The method quantified histological prostate tissue with multi-scale techniques based on nonlinear descriptors. Therefore, the use of information from color channels together with the segmented structures are most relevant to a diagnostic support system.
928

ESTUDO DO PERFIL OXIDATIVO E AVALIAÇÃO DE PARÂMETROS ENZIMÁTICOS EM PACIENTES COM CÂNCER DE PRÓSTATA. / STUDY OF OXIDATIVE PROFILE AND ENZYMATIC PARAMETERS IN PROSTATE CANCER PATIENTS.

Battisti, Vanessa 19 December 2012 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Prostate cancer is recognized as one of the most important medical problems in the male population. Inherent or acquired alterations in cellular metabolism that occur over the years may be involved in the process of developing this cancer. Thus, oxidative stress may play an important role in cellular processes associated with the initiation and development of prostate cancer. On the other hand, the cancer may be associated with changes in platelet aggregation and metabolism of nucleotides. In addition, enzymes that degrade esters of choline are well known as participating in non-cholinergic functions and intervene in important cell processes such as proliferation, differentiation and apoptosis. Considering such statements, this study aimed to evaluate the oxidative profile, through the determination of parameters such as the TBARS and protein carbonyl content and antioxidant defenses, by determine the catalase (CAT) and superoxide dismutase (SOD) activity and non-protein thiols, vitamin C and vitamin E levels. Also, determine ectonucleotidases enzyme activities represented by the enzymes NTPDase, E-NPP, 5'nucleotidase and adenosine deaminase (ADA) and verified the acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activities. In addition, we evaluated the influence of Gleason score, the presence or absence of metastasis and type of treatment used by patients in the parameters analyzed. The results show that the content of TBARS and protein carbonylation levels increased in patients when compared with the control group. In addition, changes in the antioxidant defenses were observed. The CAT activity was decreased and SOD activity increased in patients compared to controls. We found also an increase in the levels of non-protein thiols in plasma and erythrocytes and a decrease in serum levels of vitamin C and vitamin E in patients. These results suggest an increased formation of reactive species and an imbalance in the enzymatic and non-enzymatic antioxidant system defense in patients with prostate cancer. Moreover, it was observed that advanced prostate cancer is associated with a state of high oxidative stress. The results showed that nucleotides hydrolysis (ATP, ADP and AMP) were increased in patients compared to controls, which maybe observed by the increase in the enzymes activity (NTPDase, E-NPP and 5'Nucleotidase). On the other hand, our results showed a decrease in ADA activity in serum of these patients. These results reflect the increase in the nucleotide hydrolysis and the consequent increase in the adenosine concentrations that may be envolved in the tumorigenesis process. Our results also showed that inhibition of platelet aggregation was decreased only in patients with prostate cancer before starting treatment. The AChE and BuChE activities were decreased in patients in relation to the control group. The decrease in the cholinesterases activities and the consequently increase in acetylcholine levels suggest the participation of this molecule in the process of cancer development. Finally, changes in the NTPDase, 5' nucleotidase, E-NPP, ADA, AChE and BuChE activities when patients were divided in groups considering the Gleason score, presence or absence of bone metastasis and the treatment, indicate that these parameters must be considered. / O câncer de próstata é reconhecido como um dos mais importantes problemas médicos enfrentados pela população masculina. Alterações inerentes ou adquiridas no metabolismo celular que ocorrem ao longo dos anos podem ter envolvimento no processo de desenvolvimento deste tipo de câncer. Dessa forma, o estresse oxidativo pode desempenhar um papel importante nos processos celulares associados com a iniciação e o desenvolvimento do câncer de próstata. Por outro lado, o câncer pode estar associado com alterações na agregação plaquetária e no metabolismo dos nucleotídeos. Além disso, as enzimas que degradam ésteres de colina desempenham funções não colinérgicas e parecem estar envolvidas com a proliferação e diferenciação celular. Levando em consideração tais afirmativas, este trabalho teve como objetivos avaliar o perfil oxidativo, através da determinação do conteúdo de substâncias reativas ao ácido tiobarbitúrico (TBARS) e de proteína carbonil, e as defesas antioxidantes, através da determinação das atividades das enzimas catalase (CAT) e superóxido dismutase (SOD) e dos níveis de tióis nãoprotéicos, vitamina C e vitamina E. Além disso, realizar a determinação das atividades das enzimas ectonucleotidases representadas pelas enzimas NTPDase, E-NPP, 5 nucleotidase e adenosina deaminase (ADA). Por fim, verificar as atividades das enzimas acetilcolinesterase (AChE), butirilcolinesterase (BuChE) e os parâmetros bioquímicos em pacientes e controles. Esse trabalho teve ainda como objetivo, avaliar a influência da escala de Gleason, da presença ou ausência de metástase e do tipo de tratamento a que foram submetidos os pacientes, nas dosagens realizadas. Os resultados demonstram que o conteúdo de TBARS e os níveis de carbonilação de proteínas aumentaram nos pacientes quando comparados com o grupo controle e mudanças no sistema de defesa antioxidante foram observadas. A atividade da CAT estava diminuída e a atividade da SOD aumentada nos pacientes quando comparados aos controles. Verificamos ainda um aumento nos níveis de tióis não-protéicos no plasma e eritrócitos e uma diminuição nos níveis séricos de vitamina C e de vitamina E em pacientes com câncer próstata. Os resultados mostraram que a hidrólise dos nucleotídeos ATP, ADP e AMP estava aumentada nos pacientes quando comparado ao grupo controle, o que pode ser comprovado pelo aumento nas atividades das enzimas NTPDase, E-NPP e 5 Nucleotidase. Por outro lado, nossos resultados revelaram uma diminuição na atividade da ADA no soro desses pacientes. Os resultados mostraram também que a agregação plaquetária foi diminuída apenas nos pacientes com câncer de próstata antes do início do tratamento. As atividades da AChE e BuChE foram diminuídas 8 nos pacientes em relação ao grupo controle. Com os dados podemos concluir que há um aumento na formação de espécies reativas e um desequilíbrio no sistema de defesa antioxidante enzimático e não-enzimático nos pacientes. Além disso, o câncer de próstata avançado pode estar associado com um estado de estresse oxidativo elevado. Os resultados refletem também o aumento na hidrólise de nucleotídeos e o consequente aumento nas concentrações de adenosina nos pacientes, que pode estar participando do processo de tumorogênese. A diminuição nas atividades das colinesterases (AChE e BuChE) e o consequente aumento nos níveis de acetilcolina sugerem a participação da mesma no processo de desenvolvimento do câncer. Finalmente, as alterações nas atividades das enzimas NTPDase, 5 Nucleotidase, E-NPP, ADA, BuChE e AChE quando os pacientes foram divididos em grupos considerando a escala de Gleason, a presença ou ausência de metástase óssea e o fato de estar ou não em tratamento, indicam que esses parâmetros devem ser considerados.
929

Effect of 5[alpha]-reductase inhibitors on LNCaP cells, Syrian hamster flank organs, and TRAMP mice prostate cancer

Opoku-Acheampong, Alexander Boadu January 1900 (has links)
Doctor of Philosophy / Department of Human Nutrition / Brian L. Lindshield / The growth-inhibitory effect of saw palmetto supplements (SPS) with high long-chain fatty acids (FA)-low phytosterols (HLLP), high long-chain FA-high phytosterols (HLHP), and high medium-chain FA-low phytosterols (HMLP) was determined using androgen-sensitive LNCaP prostate cancer (PCa) cells and Syrian hamster flank organs. In vitro, all three SPS at high concentrations significantly decreased dihydrotestosterone-stimulated LNCaP cell number. HMLP and HLLP at high concentrations significantly decreased, but HLHP which significantly increased testosterone-stimulated LNCaP cell number. In Syrian hamsters, all three SPS treatments caused notable, but nonsignificant reduction in the difference between the left and right flank organ growth in the testosterone-, but not dihydrotestosterone-treated SPS groups. Results suggest SPS might be a mild 5-alpha-reductase (5-alpha-R) inhibitor. The pharmaceuticals finasteride inhibits 5-alpha-R2, and dutasteride inhibits 5-alpha-R1 and 5-alpha-R2 isoenzymes. Because finasteride inhibits only 5-alpha-R2, we hypothesized that it would not be as efficacious in preventing PCa development and/or progression in TRAMP mice as dutasteride. Six-week-old C57BL/6 TRAMP x FVB male mice were randomized to control, pre- and post- finasteride and dutasteride diet groups that began at 6 and 12 weeks of age, respectively, and terminated at 20 weeks of age. Pre and post groups received drugs before and after mice were expected to develop PCa, respectively. Post-Dutasteride treatment was significantly more effective than Pre-Dutasteride; and dutasteride treatments significantly more effective than finasteride treatments in decreasing prostatic intraepithelial neoplasia progression and PCa development. The finasteride groups and the Pre-Dutasteride group had significantly increased incidence of poorly differentiated PCa versus control. Androgen receptor and Ki-67 protein, DNA fragmentation from apoptosis, 5-alpha-R1 and 5-alpha-R2 mRNA levels were determined in mice with genitourinary weight less than 1 gram and greater than 1 gram to elucidate the discordant response in Pre-Dutasteride and finasteride groups, and Post-Dutasteride’s efficacy. Results suggest the difference in genitourinary weights is influenced more by proliferation, rather than androgen receptor and apoptosis in tumor. Mice age may not be significantly important in regulating proliferation, androgen receptor and apoptosis to promote tumor growth. In conclusion, the results with 5-alpha-reductase inhibitors may support the therapeutic use of dutasteride, but not finasteride, or saw palmetto supplements.
930

Nanotubes de titanate comme nanovecteurs polyvalents : radiosensibilisants du cancer de la prostate et sondes pour l'imagerie nucléaire / Titanate nanotubes as versatile nanovectors : radiosensitizers for the treatment of prostate cancer and nuclear imaging probes

Loiseau, Alexis 15 November 2017 (has links)
Actuellement, les injections systémiques de médicaments atteignent faiblement les sites tumoraux et de fortes doses sont alors administrées provoquant des effets secondaires parfois lourds. Les possibilités offertes par les applications en médecine des nanoparticules permettent de nouvelles stratégies pour vectoriser des substances actives dans les cellules malades. Ces travaux de thèse portent sur le cancer de la prostate qui est le deuxième cancer le plus diagnostiqué et la cinquième cause de décès chez les hommes dans le monde.Les nanotubes de titanate (TiONts) sont synthétisés par voie hydrothermale et présentent une longueur moyenne de 170 nm, un diamètre extérieur de 10 nm et une cavité interne accessible de 4 nm. Leur morphologie tubulaire permet aux TiONts d’être internalisés plus facilement dans les cellules, sans induire de cytotoxicité, tout en créant un effet radiosensibilisant.Deux nanohybrides ont été développés dans cette thèse, pour lutter contre le cancer de la prostate par injection intratumorale (IT) et une attention particulière a été portée sur leur élaboration. Ces nouveaux nanomédicaments ont été pleinement caractérisés par différentes techniques (MET, ATG, potentiel zêta, XPS, spectroscopies UV visible, IR et Raman).La première approche consiste à combiner les TiONts avec un agent thérapeutique (le docétaxel, DTX), largement utilisé pour inhiber les tumeurs de prostate et un agent chélatant (le DOTA, radiomarqué avec l’111In) pour suivre la biodistribution des tubes par SPECT/CT. La surface des TiONts a été préalablement fonctionnalisée par l’APTES et le poly(éthylène) glycol (PEG3000) pour rendre les TiONts stables et biocompatibles. Afin d’évaluer l’efficacité de ce nanohybride, des tests in vitro ont montré que l’association entre les TiONts et le DTX permettait de maintenir une activité cytotoxique sur des lignées cellulaires de prostate (cellules 22Rv1 et PC 3) alors que les TiONts sans le DTX n’étaient pas toxiques. Les études in vivo ont montré, sur des souris Swiss nude mâles, que plus de 70% des nanovecteurs étaient retenus dans la tumeur, après injection IT, après 7 jours. De plus, un retard de croissance tumorale pour les souris ayant reçu le nanohybride avec la radiothérapie (RT) est observé, par rapport aux souris ayant reçues seulement le DTX. Après cette étude, d’autres molécules organiques ont été greffées avec succès à la surface des TiONts pour améliorer la stabilité colloïdale et la biocompatibilité des nanotubes : AHAMTES, catéchols (LDOPA, DHCA et NDOPA), phosphonates (PHA, ALD et un polymère hétérobifonctionnel de type phosphonate : (HO)2 (O)P-PEG NH2). De plus, le greffage de différentes longueurs de chaîne de PEG a été évalué par deux voies de synthèses. Le greffage de ces PEG en milieu organique (PyBOP) s’est avéré très prometteur pour améliorer leur taux de greffage et leur stabilité colloïdale.Dans une seconde approche, pour accroître l’effet radiosensibilisant, des nanoparticules d’or (AuNPs), elles-mêmes modifiées par le DTDTPA, ont été couplées avec les TiONts en présence ou non de DTX. Cette nouvelle combinaison a pour objectif le maintien des AuNPs, par les TiONts, dans la tumeur afin d’améliorer l’effet de la RT. Grâce aux AuNPs modifiées par le DTDTPA, le nanohybride est également détectable par imagerie X et par SPECT/CT. Les résultats in vitro ont démontré l’activité cytotoxique de l’édifice final. Des études de biodistribution et de croissance tumorale ont également été réalisées sur des tumeurs PC-3 xénogreffées sur des souris.Ces TiONts fonctionnalisés apparaissent comme un nouvel outil polyvalent dans le domaine médical, notamment pour lutter contre le cancer de la prostate. / Currently, the systemic injections of drugs reach very weakly tumor sites and large doses are thus administered causing adverse side effects. The new implementations of nanoparticles in the medical field offer new strategies to vectorize an active substance in diseased cells. This work is focused on the prostate cancer, which is the second most frequently diagnosed cancer and the fifth leading cause of cancer death in men worldwide.Titanate nanotubes (TiONts) are synthetized by a hydrothermal process and have average dimensions of about 170 nm in length, 10 nm in outer diameter and also have an internal cavity of 4 nm in diameter. Their needle-shaped morphology allows them to be internalized more easily into cells without inducing cytotoxicity while providing a radiosensitization effect.In the present manuscript are described two TiONts-based nanohybrids which were developed with a view to fight against prostate cancer by intratumoral (IT) injection and a particular attention was paid on their elaboration. These new nanomedicines were extensively characterized by different techniques (TEM, TGA, ζ potential, XPS, UV visible, IR and Raman spectroscopies).The first approach that has been developed consists in combining TiONts with a therapeutic agent (docetaxel, DTX), widely used for the treatment of prostate cancer, and a chelating agent (DOTA) allowing the radiolabeling with 111In radionuclide to monitor TiONts biodistribution by SPECT/CT. The surface of TiONts was beforehand coated with a siloxane (APTES) and linked to a heterobifunctional polymer (PEG3000) to create well-dispersed and biocompatible TiONts. In vitro tests demonstrated that the association between TiONts and DTX had cytotoxic activity against prostate cancer cell lines (22Rv1 and PC-3 cells) whereas TiONts without DTX did not. The results of in vivo SPECT/CT imaging are also presented as well as first irradiation tests in Swiss nude mice after IT injection on PC-3 tumors. Biological tests showed that more than 70% of TiONts nanovectors were retained within the tumor for at least 7 days. In addition, tumor growth of mice receiving nanohybrids with radiotherapy was significantly slower than that of mice receiving free DTX. After this first study, other organic molecules were successfully grafted to the surface of TiONts to improve colloidal stability and biocompatibility of nanotubes: AHAMTES, catechols (LDOPA, DHCA and NDOPA) and phosphonates (PHA, ALD and a phosphonate heterobifunctional polymer-based: (HO)2 (O)P PEG NH2). Moreover, the influence of different PEG lengths has been considered on the nanomedicine efficacy by two different pathways. The grafting of these PEG in an organic medium (PyBOP) was very promising to improve their graft ratio and their colloidal stability.In a second approach and in order to improve the radiosensitizing effect, DTDTPA-modified gold nanoparticles (AuNPs) were coupled with TiONts in the presence of DTX. This novel combination aims at retaining these AuNPs into the tumor via the TiONts to enhance the radiotherapeutic effect. The nanohybrid was also detectable by X-ray and SPECT/CT imaging through AuNPs-DTDTPA. Preliminary in vitro results showed once again that our final nanohybrid had a satisfactory cytotoxic activity. Biodistribution and tumor growth studies were also realized on PC-3 xenografted tumors on mice.These functionalized-TiONts could thus become a new tool in the field of biomedicine to fight against prostate cancer and appear as versatile nanovectors.

Page generated in 0.0926 seconds