997 resultados para tumor classification
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Tumor necrosis factor receptor 1 (TNFR1) and Toll-like receptors (TLRs) regulate immune and inflammatory responses. Here we show that the TNFR1-associated death domain protein (TRADD) is critical in TNFR1, TLR3 and TLR4 signaling. TRADD deficiency abrogated TNF-induced apoptosis, prevented recruitment of the ubiquitin ligase TRAF2 and ubiquitination of the adaptor RIP1 in the TNFR1 signaling complex, and considerably inhibited but did not completely abolish activation of the transcription factor NF-kappaB and mitogen-activated protein kinases 'downstream' of TNFR1. TRIF-dependent cytokine production induced by the synthetic double-stranded RNA poly(I:C) and lipopolysaccharide was lower in TRADD-deficient mice than in wild-type mice. Moreover, TRADD deficiency inhibited poly(I:C)-mediated RIP1 ubiquitination and activation of NF-kappaB and mitogen-activated protein kinase signaling in fibroblasts but not in bone marrow macrophages. Thus, TRADD is an essential component of TNFR1 signaling and has a critical but apparently cell type-specific function in TRIF-dependent TLR responses.
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Transcriptional deregulation in cancer has been shown to be associated with epigenetic alterations, in particular to tumor-suppressor- gene (TSG) promoters. In contrast, DNA methylation of TSGs is not considered to be present in normal differentiated cells. Nevertheless, we previously showed that the promoter of the tumor-suppressor gene APC is methylated, for one allele only, in normal gastric cells. Recently, RASSF1A has been shown to be imprinted in normal human placenta. To clarify putative TSG methylation in the placenta, 23 normal placental tissues from the first trimester, both decidua and villi, and four normal non-gestational endometrium were screened for DNA methylation by methylation-sensitive single-strand conformation analysis (MS-SSCA) and sequencing after bisulfite modification, on a panel of 12 genes known to be implicated in carcinogenesis. In all placental villi, four TSG promoters-APC, SFRP2, RASSF1A and WIF1-were hypermethylated, whereas all decidua and normal endometrium did not show any methylation. Allele-specific methylation analysis revealed that this methylation was monoallelic. Furthermore, comparison with maternal DNA indicated that APC and WIF1 were methylated on the maternal allele, whereas SFRP2 was methylated on the paternal allele. Sequence analysis of WIF1 mRNA revealed that only the unmethylated paternal allele was transcribed. The imprinting status of these TSGs is conserved during pregnancy. These results indicate that TSG imprinting is pre-existent in normal human placenta and should not be confused with carcinogenesis or pathology-induced methylation.
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BACKGROUND Tumor expression of estrogen receptor (ER) is an important marker of prognosis, and is predictive of response to endocrine therapy in breast cancer. Several studies have observed that epigenetic events, such methylation of cytosines and deacetylation of histones, are involved in the complex mechanisms that regulate promoter transcription. However, the exact interplay of these factors in transcription activity is not well understood. In this study, we explored the relationship between ER expression status in tumor tissue samples and the methylation of the 5' CpG promoter region of the estrogen receptor gene (ESR1) isolated from free circulating DNA (fcDNA) in plasma samples from breast cancer patients. METHODS Patients (n = 110) with non-metastatic breast cancer had analyses performed of ER expression (luminal phenotype in tumor tissue, by immunohistochemistry method), and the ESR1-DNA methylation status (fcDNA in plasma, by quantitative methylation specific PCR technique). RESULTS Our results showed a significant association between presence of methylated ESR1 in patients with breast cancer and ER negative status in the tumor tissue (p = 0.0179). There was a trend towards a higher probability of ESR1-methylation in those phenotypes with poor prognosis i.e. 80% of triple negative patients, 60% of HER2 patients, compared to 28% and 5.9% of patients with better prognosis such as luminal A and luminal B, respectively. CONCLUSION Silencing, by methylation, of the promoter region of the ESR1 affects the expression of the estrogen receptor protein in tumors of breast cancer patients; high methylation of ESR1-DNA is associated with estrogen receptor negative status which, in turn, may be implicated in the patient's resistance to hormonal treatment in breast cancer. As such, epigenetic markers in plasma may be of interest as new targets for anticancer therapy, especially with respect to endocrine treatment.
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We report a case series of three children with solid pseudopapillary tumor of the pancreas (SPT) in which a complete radiological work-up, including ultrasound, computed tomography scans, and MRI, has been carried out. The aim of this article is to highlight the characteristic imaging findings of SPT in the pediatric age group and to establish a correlation with typical histopathological findings of the lesion.
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The function of interleukin-3 (or multi-CSF) in the hemopoietic system has been studied in great detail. Although its growth promoting activity on brain microglial cells has been confirmed both in vitro and in vivo, its presence in the brain and even in cultured brain cells has repeatedly been questioned. We have shown recently that isolated rat microglia express mRNA(IL-3) and synthesize IL-3 polypeptide. It is shown here by use of the PCR method, that mRNA(IL-3) is found also in C6 glioblastoma, in rat aggregate cultures, and in newborn and adult rat brain. Quantitation of amplified cDNA(IL-3) was achieved by non-competitive RT-PCR using an elongated internal standard. IL-3 messenger RNA was almost undetectable in vivo and low in (serum-free) aggregate cultures. In isolated microglia, mRNA(IL-3) was increased upon treatment with LPS, PHA, with the cytokines IL-1 or TNF-alpha, with retinoic acid, dbcAMP or the phorbol ester TPA. Effects of LPS were inhibited by dexamethasone, while the glucocorticoid by itself had no effect on basal IL-3 expression. LPS increased mRNA(IL-3) in a concentration-dependent manner beginning with 10 pg/ml and reaching plateau levels at 10 ng/ml. LPS also increased mRNAs of TNF-alpha and TNF-beta. TNF-alpha mRNA was already detectable in untreated microglia and LPS-increased levels were sustained for a few days. In contrast, TNF-beta mRNA was observed only between 4 and 16 h of LPS incubation. It was absent in LPS-free microglia, and after 24 h of LPS-treatment or later.(ABSTRACT TRUNCATED AT 250 WORDS)
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Malignant gliomas are currently diagnosed based on morphological criteria and graded according to the World Health Organization classification of primary brain tumors. This algorithm of diagnosis and classification provides clinicians with an estimated prognosis of the natural course of the disease. It does not reflect the expected response to specific treatments beyond surgery (eg, radiotherapy or alkylating chemotherapy). Clinical experience has revealed that gliomas sharing similar histomorphological criteria might indeed have different clinical courses and exhibit highly heterogenous responses to treatments. This was very impressively demonstrated first for oligodendrogliomas. The presence or lack of combined deletions of the chromosomal segments 1p/19q was associated with different benefit from radiotherapy and chemotherapy. We review current molecular markers for malignant gliomas and discuss their current and future impact on clinical neuro-oncology.
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A statistical method for classification of sags their origin downstream or upstream from the recording point is proposed in this work. The goal is to obtain a statistical model using the sag waveforms useful to characterise one type of sags and to discriminate them from the other type. This model is built on the basis of multi-way principal component analysis an later used to project the available registers in a new space with lower dimension. Thus, a case base of diagnosed sags is built in the projection space. Finally classification is done by comparing new sags against the existing in the case base. Similarity is defined in the projection space using a combination of distances to recover the nearest neighbours to the new sag. Finally the method assigns the origin of the new sag according to the origin of their neighbours
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Invariant NKT (iNKT) cells are potent activators of DCs, NK cells, and T cells, and their antitumor activity has been well demonstrated. A single injection of the high-affinity CD1d ligand alpha-galactosylceramide (alphaGalCer) leads to short-lived iNKT cell activation followed, however, by long-term anergy, limiting its therapeutic use. In contrast, we demonstrated here that when alphaGalCer was loaded on a recombinant soluble CD1d molecule (alphaGalCer/sCD1d), repeated injections led to sustained iNKT and NK cell activation associated with IFN-gamma secretion as well as DC maturation in mice. Most importantly, when alphaGalCer/sCD1d was fused to a HER2-specific scFv antibody fragment, potent inhibition of experimental lung metastasis and established s.c. tumors was obtained when systemic treatment was started 2-7 days after the injection of HER2-expressing B16 melanoma cells. In contrast, administration of free alphaGalCer at this time had no effect. The antitumor activity of the CD1d-anti-HER2 fusion protein was associated with HER2-specific tumor localization and accumulation of iNKT, NK, and T cells at the tumor site. Targeting iNKT cells to the tumor site thus may activate a combined innate and adaptive immune response that may prove to be effective in cancer immunotherapy
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BACKGROUND: Inherited ichthyoses belong to a large, clinically and etiologically heterogeneous group of mendelian disorders of cornification, typically involving the entire integument. Over the recent years, much progress has been made defining their molecular causes. However, there is no internationally accepted classification and terminology. OBJECTIVE: We sought to establish a consensus for the nomenclature and classification of inherited ichthyoses. METHODS: The classification project started at the First World Conference on Ichthyosis in 2007. A large international network of expert clinicians, skin pathologists, and geneticists entertained an interactive dialogue over 2 years, eventually leading to the First Ichthyosis Consensus Conference held in Sorèze, France, on January 23 and 24, 2009, where subcommittees on different issues proposed terminology that was debated until consensus was reached. RESULTS: It was agreed that currently the nosology should remain clinically based. "Syndromic" versus "nonsyndromic" forms provide a useful major subdivision. Several clinical terms and controversial disease names have been redefined: eg, the group caused by keratin mutations is referred to by the umbrella term, "keratinopathic ichthyosis"-under which are included epidermolytic ichthyosis, superficial epidermolytic ichthyosis, and ichthyosis Curth-Macklin. "Autosomal recessive congenital ichthyosis" is proposed as an umbrella term for the harlequin ichthyosis, lamellar ichthyosis, and the congenital ichthyosiform erythroderma group. LIMITATIONS: As more becomes known about these diseases in the future, modifications will be needed. CONCLUSION: We have achieved an international consensus for the classification of inherited ichthyosis that should be useful for all clinicians and can serve as reference point for future research.
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The 2008 Data Fusion Contest organized by the IEEE Geoscience and Remote Sensing Data Fusion Technical Committee deals with the classification of high-resolution hyperspectral data from an urban area. Unlike in the previous issues of the contest, the goal was not only to identify the best algorithm but also to provide a collaborative effort: The decision fusion of the best individual algorithms was aiming at further improving the classification performances, and the best algorithms were ranked according to their relative contribution to the decision fusion. This paper presents the five awarded algorithms and the conclusions of the contest, stressing the importance of decision fusion, dimension reduction, and supervised classification methods, such as neural networks and support vector machines.
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Here we present the first in a series of articles about the ecology of immature stages of anophelines in the Brazilian Yanomami area. We propose a new larval habitat classification and a new larval sampling methodology. We also report some preliminary results illustrating the applicability of the methodology based on data collected in the Brazilian Amazon rainforest in a longitudinal study of two remote Yanomami communities, Parafuri and Toototobi. In these areas, we mapped and classified 112 natural breeding habitats located in low-order river systems based on their association with river flood pulses, seasonality and exposure to sun. Our classification rendered seven types of larval habitats: lakes associated with the river, which are subdivided into oxbow lakes and nonoxbow lakes, flooded areas associated with the river, flooded areas not associated with the river, rainfall pools, small forest streams, medium forest streams and rivers. The methodology for larval sampling was based on the accurate quantification of the effective breeding area, taking into account the area of the perimeter and subtypes of microenvironments present per larval habitat type using a laser range finder and a small portable inflatable boat. The new classification and new sampling methodology proposed herein may be useful in vector control programs.
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Soluble peptide/MHC-class-I (pMHC) multimers have recently emerged as unique reagents for the study of specific interactions between the pMHC complex and the TCR. Here, we assessed the relative binding efficiency of a panel of multimers incorporating single-alanine-substituted variants of the tumor-antigen-derived peptide MAGE-A10(254-262) to specific CTL clones displaying different functional avidity. For each individual clone, the efficiency of binding of multimers incorporating MAGE-A10 peptide variants was, in most cases, in good although not linear correlation with the avidity of recognition of the corresponding variant. In addition, we observed two types of discrepancies between efficiency of recognition and multimer binding. First, for some peptide variants, efficient multimer binding was detected in the absence of measurable effector functions. Some of these peptide variants displayed antagonist activity. Second, when comparing different clones we found clear discrepancies between the dose of peptide required to obtain half-maximal lysis in CTL assays and the binding efficiency of the corresponding multimers. These discrepancies, however, were resolved when the differential stability of the TCR/pMHC complexes was determined. For individual clones, decreased recognition correlated with increased TCR/pMHC off-rate. TCR/pMHC complexes formed by antagonist ligands displayed off-rates faster than those of TCR/pMHC complexes formed with weak agonists. In addition, when comparing different clones, the efficiency of multimer staining correlated better with relative multimer off-rates than with half-maximal lysis values. Altogether, the data presented here reconcile and extend our previous results on the impact of the kinetics of interaction of TCR with pMHC complexes on multimer binding and underline the crucial role of TCR/pMHC off-rates for the functional outcome of such interactions.