286 resultados para B ... n C ... f.
Resumo:
Secretory factors that drive cancer progression are attractive immunotherapeutic targets. We used a whole-genome data-mining approach on multiple cohorts of breast tumours annotated for clinical outcomes to discover such factors. We identified Serine protease inhibitor Kazal-type 1 (SPINK1) to be associated with poor survival in estrogen receptor-positive (ER+) cases. Immunohistochemistry showed that SPINK1 was absent in normal breast, present in early and advanced tumours, and its expression correlated with poor survival in ER+ tumours. In ER- cases, the prognostic effect did not reach statistical significance. Forced expression and/or exposure to recombinant SPINK1 induced invasiveness without affecting cell proliferation. However, down-regulation of SPINK1 resulted in cell death. Further, SPINK1 overexpressing cells were resistant to drug-induced apoptosis due to reduced caspase-3 levels and high expression of Bcl2 and phospho-Bcl2 proteins. Intriguingly, these anti-apoptotic effects of SPINK1 were abrogated by mutations of its protease inhibition domain. Thus, SPINK1 affects multiple aggressive properties in breast cancer: survival, invasiveness and chemoresistance. Because SPINK1 effects are abrogated by neutralizing antibodies, we suggest that SPINK1 is a viable potential therapeutic target in breast cancer.
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A systematic approach to develop the teaching of instrumental analytical chemistry is discussed, as well as a conceptual framework for organizing and executing lectures and a laboratory course. Three main components are used in this course: theoretical knowledge developed in the classroom, simulations via a virtual laboratory, and practical training via experimentation. Problem-based learning and cooperative-learning methods are applied in both the classroom and laboratory aspects of the course. In addition, some reflections and best practices are presented on how to encourage students to learn actively. Overall, a student-centered environment is proposed that aims to cultivate students' practical abilities and individual talents.
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Resumo:
Many plain text information hiding techniques demand deep semantic processing, and so suffer in reliability. In contrast, syntactic processing is a more mature and reliable technology. Assuming a perfect parser, this paper evaluates a set of automated and reversible syntactic transforms that can hide information in plain text without changing the meaning or style of a document. A large representative collection of newspaper text is fed through a prototype system. In contrast to previous work, the output is subjected to human testing to verify that the text has not been significantly compromised by the information hiding procedure, yielding a success rate of 96% and bandwidth of 0.3 bits per sentence. © 2007 SPIE-IS&T.
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We present three natural language marking strategies based on fast and reliable shallow parsing techniques, and on widely available lexical resources: lexical substitution, adjective conjunction swaps, and relativiser switching. We test these techniques on a random sample of the British National Corpus. Individual candidate marks are checked for goodness of structural and semantic fit, using both lexical resources, and the web as a corpus. A representative sample of marks is given to 25 human judges to evaluate for acceptability and preservation of meaning. This establishes a correlation between corpus based felicity measures and perceived quality, and makes qualified predictions. Grammatical acceptability correlates with our automatic measure strongly (Pearson's r = 0.795, p = 0.001), allowing us to account for about two thirds of variability in human judgements. A moderate but statistically insignificant (Pearson's r = 0.422, p = 0.356) correlation is found with judgements of meaning preservation, indicating that the contextual window of five content words used for our automatic measure may need to be extended. © 2007 SPIE-IS&T.
Resumo:
Plaques constructed with 125I were used to irradiate the sites of perforating ocular injuries in rabbits. An approximate dose of 16Gy given over a period of 6 days was shown to significantly reduce intraocular cellular proliferation when irradiation was commenced within 24 hours after injury. If irradiation was delayed until day 5, this reduction in cellular proliferation and intraocular membrane formation did not occur. Smaller radiation doses of approximately 6Gy given within 24 hours post-injury and administered over 6 days also reduced the extent of cellular proliferation but was not as effective as the 16Gy dose.
Resumo:
Focal gamma irradiation was used to limit the intraocular extension of scar tissue which typically occurs after posterior perforating injury to the eye. Standard posterior perforating injuries were created in the right eye of forty-eight rabbits, half of which had the site of perforation focally irradiated using a Cobalt 60 ophthalmic plaque. Non-irradiated wounds healed with profuse formation of highly cellular and vascularised granulation tissue which invaded the vitreous to form contractile vitreo-retinal membranes. In irradiated eyes vitreo-retinal membrane formation was infrequent; the wounds showing only sparse granulation tissue with little or no extension into the vitreous cavity. Autoradiographic studies carried out in a second group of 40 animals showed that the episclera was the main source of the proliferating fibroblasts, and cell counts confirmed that the inflammatory and repair responses in irradiated wounds were both delayed and attenuated.
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Schizophrenia is clinically heterogeneous. Recent linkage studies suggest that multiple genes are important in the etiology of schizophrenia. The authors examined the hypothesis of whether the clinical variability in schizophrenia is due to genetic heterogeneity.
Resumo:
Background: We investigate whether differences in breast cancer survival in six high-income countries can be explained by differences in stage at diagnosis using routine data from population-based cancer registries. Methods: We analysed the data on 257 362 women diagnosed with breast cancer during 2000-7 and registered in 13 population-based cancer registries in Australia, Canada, Denmark, Norway, Sweden and the UK. Flexible parametric hazard models were used to estimate net survival and the excess hazard of dying from breast cancer up to 3 years after diagnosis.Results:Age-standardised 3-year net survival was 87-89% in the UK and Denmark, and 91-94% in the other four countries. Stage at diagnosis was relatively advanced in Denmark: only 30% of women had Tumour, Nodes, Metastasis (TNM) stage I disease, compared with 42-45% elsewhere. Women in the UK had low survival for TNM stage III-IV disease compared with other countries. Conclusion: International differences in breast cancer survival are partly explained by differences in stage at diagnosis, and partly by differences in stage-specific survival. Low overall survival arises if the stage distribution is adverse (e.g. Denmark) but stage-specific survival is normal; or if the stage distribution is typical but stage-specific survival is low (e.g. UK). International differences in staging diagnostics and stage-specific cancer therapies should be investigated. © 2013 Cancer Research UK. All rights reserved.
Resumo:
Objective: We investigate what role stage at diagnosis bears in international differences in ovarian cancer survival. Methods: Data from population-based cancer registries in Australia, Canada, Denmark, Norway, and the UK were analysed for 20,073 women diagnosed with ovarian cancer during 2004-07. We compare the stage distribution between countries and estimate stage-specific one-year net survival and the excess hazard up to 18 months after diagnosis, using flexible parametric models on the log cumulative excess hazard scale. Results: One-year survival was 69% in the UK, 72% in Denmark and 74-75% elsewhere. In Denmark, 74% of patients were diagnosed with FIGO stages III-IV disease, compared to 60-70% elsewhere. International differences in survival were evident at each stage of disease; women in the UK had lower survival than in the other four countries for patients with FIGO stages III-IV disease (61.4% vs. 65.8-74.4%). International differences were widest for older women and for those with advanced stage or with no stage data. Conclusion: Differences in stage at diagnosis partly explain international variation in ovarian cancer survival, and a more adverse stage distribution contributes to comparatively low survival in Denmark. This could arise because of differences in tumour biology, staging procedures or diagnostic delay. Differences in survival also exist within each stage, as illustrated by lower survival for advanced disease in the UK, suggesting unequal access to optimal treatment. Population-based data on cancer survival by stage are vital for cancer surveillance, and global consensus is needed to make stage data in cancer registries more consistent. © 2012 Elsevier Inc.
Resumo:
Background: There is no method routinely used to predict response to anthracycline and cyclophosphamide–based chemotherapy in the clinic; therefore patients often receive treatment for breast cancer with no benefit. Loss of the Fanconi anemia/BRCA (FA/BRCA) DNA damage response (DDR) pathway occurs in approximately 25% of breast cancer patients through several mechanisms and results in sensitization to DNA-damaging agents. The aim of this study was to develop an assay to detect DDR-deficient tumors associated with loss of the FA/BRCA pathway, for the purpose of treatment selection.r/>
/>Methods: DNA microarray data from 21 FA patients and 11 control subjects were analyzed to identify genetic processes associated with a deficiency in DDR. Unsupervised hierarchical clustering was then performed using 60 BRCA1/2 mutant and 47 sporadic tumor samples, and a molecular subgroup was identified that was defined by the molecular processes represented within FA patients. A 44-gene microarray-based assay (the DDR deficiency assay) was developed to prospectively identify this subgroup from formalin-fixed, paraffin-embedded samples. All statistical tests were two-sided.r/>
/>Results: In a publicly available independent cohort of 203 patients, the assay predicted complete pathologic response vs residual disease after neoadjuvant DNA-damaging chemotherapy (5-fluorouracil, anthracycline, and cyclophosphamide) with an odds ratio of 3.96 (95% confidence interval [Cl] =1.67 to 9.41; P = .002). In a new independent cohort of 191 breast cancer patients treated with adjuvant 5-fluorouracil, epirubicin, and cyclophosphamide, a positive assay result predicted 5-year relapse-free survival with a hazard ratio of 0.37 (95% Cl = 0.15 to 0.88; P = .03) compared with the assay negative population.r/>
/>Conclusions: A formalin-fixed, paraffin-embedded tissue-based assay has been developed and independently validated as a predictor of response and prognosis after anthracycline/cyclophosphamide–based chemotherapy in the neoadjuvant and adjuvant settings. These findings warrant further validation in a prospective clinical study.