172 resultados para PROSTATE NEOPLASMS


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This paper presents a novel segmentation method for cuboidal cell nuclei in images of prostate tissue stained with hematoxylin and eosin. The proposed method allows segmenting normal, hyperplastic and cancerous prostate images in three steps: pre-processing, segmentation of cuboidal cell nuclei and post-processing. The pre-processing step consists of applying contrast stretching to the red (R) channel to highlight the contrast of cuboidal cell nuclei. The aim of the second step is to apply global thresholding based on minimum cross entropy to generate a binary image with candidate regions for cuboidal cell nuclei. In the post-processing step, false positives are removed using the connected component method. The proposed segmentation method was applied to an image bank with 105 samples and measures of sensitivity, specificity and accuracy were compared with those provided by other segmentation approaches available in the specialized literature. The results are promising and demonstrate that the proposed method allows the segmentation of cuboidal cell nuclei with a mean accuracy of 97%. © 2013 Elsevier Ltd. All rights reserved.

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Pós-graduação em Bases Gerais da Cirurgia - FMB

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Prostatic lesions such as prostatic intraepithelial neoplasia (PIN) and proliferative inflammatory atrophy (PIA) are studied in human and canine species due to their malignance potential. The plasminogen activator (PA) system has been suggested to play a central role in cell adhesion, angiogenesis, inflammation, and tumor invasion. The urokinase-type plasminogen activator receptor (uPAR) is a component of the PA, with a range of expression in tumor and stromal cells. In this study, uPAR expression in both canine normal prostates and with proliferative disorders (benign prostatic hyperplasia-BPH, proliferative inflammatory atrophy-PIA, prostatic intraepithelial neoplasia-PIN, and carcinoma-PC) was evaluated by immunohistochemistry in a tissue microarray (TMA) slide to establish the role of this enzyme in extracellular matrix (ECM) remodeling and in the processes of tissue invasion. A total of 298 cores and 355 diagnoses were obtained, with 36 (10.1%) normal prostates, 46 (13.0%) with BPH, 128 (36.1%) with PIA, 74 (20.8%) with PIN and 71 (20.0%) with PC. There is variation in the expression of uPAR in canine prostate according to the lesion, with lower expression in normal tissue and with BPH, and higher expression in tissue with PIA, PIN and PC. The high expression of uPAR in inflammatory and neoplastic microenvironment indicates increased proteolytic activity in canine prostates with PIA, PIN, and PC.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Considering the increasing consumption of saturated fat and glucose in diets worldwide and its possible association to carcinogenesis, this investigation analysed the proliferation profile of nonmalignant human prostate epithelial cells after exposure to elevated levels of fat and glucose. PNT1A cells were cultured with palmitate (100 or 200 mu M) and/or glucose (450mg/dl) for 24 or 48 h. Treated cells were evaluated for viability test and cell proliferation (MTS assay). AKT and AMPK phosphorylation status were analysed by Western blotting. After 24 h of high-fat alone or associated with high-glucose treatment, there was an increase in AMPK and AKT activation associated to unchanged MTS-cell proliferation. Following 48 h of high-fat but not high-glucose alone, cells decreased AMPK activation and maintained elevated AKT levels. These data were associated to increased cell proliferation after further high-fat treatment. After longer high-fat exposure, MTS revealed that cells remained proliferating. High-glucose alone or associated to high-fat treatment was not able to increase cell proliferation and AKT activation. A high-fat medium containing 100 mu M of palmitate stimulates proliferation in PNT1A cells by decreasing the activation of AMPK and increasing activation of AKT after longer exposure time. These findings improve the knowledge about the negative effect of high levels of this saturated fatty acid on proliferative disorders of prostate.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Despite recent advances in understanding the biological basis ofprostate cancer (PCa), the management of this disease remains a challenge. Chemoprotective agents have been usedto protect against or eradicateprostatemalignancies. Here, we investigated the protective effect of -tocopherol on N-methyl-N-nitrosourea (MNU)-induced epithelial dysplasia in the rat ventral prostate (VP). Thirty-two male Wistar rats were divided into four groups (n=8): control (CT): healthy control animals fed a standard diet; control+-tocopherol (CT+T): healthy control animals without intervention fed a -tocopherol-enriched diet (20mg/kg); N-methyl-N-nitrosourea (MNU): rats that received a single dose of MNU (30mg/kg) plus testosterone propionate (100mg/kg) and were fed a standard diet; and MNU+-tocopherol (MNU+T): rats that received the same treatment of MNU plus testosterone and were fed with a -tocopherol-enriched diet (20mg/kg). After 4months, the VPs were excised to evaluate morphology, cell proliferation and apoptosis, as well as cyclooxygenase-2 (Cox-2), glutathione-S-transferase-pi (GST-pi) and androgen receptor (AR) protein expression, and matrix metalloproteinase-9 (MMP-9) activity. An increase in the incidence of epithelial dysplasias, such as stratified epithelial hyperplasia and squamous metaplasia, in the MNU group was accompanied by augmented cell proliferation, GST-pi and Cox-2 immunoexpression and pro-MMP-9 activity. Stromal thickening and inflammatory foci were also observed. The administration of a -tocopherol-enriched diet significantly attenuated the adverse effects of MNU in the VP. The incidence of epithelial dysplasia decreased, along with the cell proliferation index, GST-pi and Cox-2 immunoexpression. The gelatinolytic activity of pro-MMP-9 returned to the levels observed for the CT group. These results suggest that -tocopherol acts as a protective agent against MNU-induced prostatic disorders in the rat ventral prostate.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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This study presents a comprehensive view of the histological and functional status of the prostate of adult rat offspring of mothers subjected to gestational diabetes induced by alloxan. The ventral prostate of male adult offspring of diabetic (DP) or normal (CP) mothers was evaluated for collagen fibres, cell death, fibroblasts, smooth muscle cells, cell proliferation, matrix metalloproteinases (MMPs), androgen receptors (AR), transforming growth factor beta 1 (TGF beta-1), catalase and total antioxidant activity. The prostates of DP animals were lower in weight than those of the CP group. The DP group also exhibited hyperglycaemia and hypotestosteronemia, higher cell proliferation and AR expression, a reduction in alpha-actin (possibly interfering with the reproductive function of the prostate), and enhanced activity of MMP-2, although the absolute content of MMP-2 was lower in this group. These findings were associated with increased TGF beta-1 and decreased collagen distribution. The prostates of DP rats additionally exhibited reductions in catalase and total antioxidant activity. Thus, rats developing in a diabetic intrauterine environment have glycaemic and hormonal changes that impact on the structure and physiology of the prostate in adulthood. The increased AR expression possibly leads to elevated cell proliferation. Stromal remodelling was characterized by enhanced activity of MMP-2 and collagen degradation, even with increased TGF beta-1 activation. These changes associated with increased oxidative stress might interfere with tissue architecture and glandular homeostasis.

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Prostate cancer is a serious public health problem accounting for up to 30% of clinical tumors in men. The diagnosis of this disease is made with clinical, laboratorial and radiological exams, which may indicate the need for transrectal biopsy. Prostate biopsies are discerningly evaluated by pathologists in an attempt to determine the most appropriate conduct. This paper presents a set of techniques for identifying and quantifying regions of interest in prostatic images. Analyses were performed using multi-scale lacunarity and distinct classification methods: decision tree, support vector machine and polynomial classifier. The performance evaluation measures were based on area under the receiver operating characteristic curve (AUC). The most appropriate region for distinguishing the different tissues (normal, hyperplastic and neoplasic) was defined: the corresponding lacunarity values and a rule's model were obtained considering combinations commonly explored by specialists in clinical practice. The best discriminative values (AUC) were 0.906, 0.891 and 0.859 between neoplasic versus normal, neoplasic versus hyperplastic and hyperplastic versus normal groups, respectively. The proposed protocol offers the advantage of making the findings comprehensible to pathologists. (C) 2014 Elsevier Ltd. All rights reserved.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)