669 research outputs found

    ChIP-BIT: Bayesian inference of target genes using a novel joint probabilistic model of ChIP-seq profiles.

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    Chromatin immunoprecipitation with massively parallel DNA sequencing (ChIP-seq) has greatly improved the reliability with which transcription factor binding sites (TFBSs) can be identified from genome-wide profiling studies. Many computational tools are developed to detect binding events or peaks, however the robust detection of weak binding events remains a challenge for current peak calling tools. We have developed a novel Bayesian approach (ChIP-BIT) to reliably detect TFBSs and their target genes by jointly modeling binding signal intensities and binding locations of TFBSs. Specifically, a Gaussian mixture model is used to capture both binding and background signals in sample data. As a unique feature of ChIP-BIT, background signals are modeled by a local Gaussian distribution that is accurately estimated from the input data. Extensive simulation studies showed a significantly improved performance of ChIP-BIT in target gene prediction, particularly for detecting weak binding signals at gene promoter regions. We applied ChIP-BIT to find target genes from NOTCH3 and PBX1 ChIP-seq data acquired from MCF-7 breast cancer cells. TF knockdown experiments have initially validated about 30% of co-regulated target genes identified by ChIP-BIT as being differentially expressed in MCF-7 cells. Functional analysis on these genes further revealed the existence of crosstalk between Notch and Wnt signaling pathways

    Primary appendiceal mucinous adenocarcinoma in two first-degree relatives: case report and review

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    Carcinomas of the appendix are exceedingly rare tumors and have an annual age-adjusted incidence of around 0.4 cases per 100,000. Appendiceal adenocarcinoma accounts for < 0.5% of all gastrointestinal neoplasms and, of these, mucinous adenocarcinomas account for the majority. Published accounts of familial instances of primary appendiceal tumors are strikingly rare. We report two siblings who both developed primary mucinous adenocarcinomas. A genetics evaluation was conducted to determine if there was a recognizable underlying single gene disorder; no DNA mismatch repair defect was evident, and no other diagnosis was apparent. A review of appendiceal cancers seen at Mayo Clinic from l997 to the present was conducted to search for additional familial cases. Among 316 cases of primary appendiceal cancer of any histologic type, this sib pair was the only family reporting a second affected family member. The occurrence of appendiceal cancer in siblings may represent a random occurrence. An exceedingly rare predisposition syndrome cannot be ruled out

    Evidence for surface defect passivation as the origin of the remarkable photostability of unencapsulated perovskite solar cells employing aminovaleric acid as a processing additive

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    This study addresses the cause of enhanced stability of methyl ammonium lead iodide when processed with aminovaleric acid additives (AVA-MAPbI3) in screen printed, hole transport layer free perovskite solar cells with carbon top electrodes (c-PSC). Employing AVA as an additive in the active layer caused a 40-fold increase in device lifetime measured under full sun illumination in ambient air (RH ∼ 15%). This stability improvement with AVA was also observed in optical photobleaching studies of planar films on glass, indicating this improvement is intrinsic to the perovskite film. Employing low-energy ion scattering spectroscopy, photoluminescence studies as a function of AVA and oxygen exposure, and a molecular probe for superoxide generation, we conclude that even though superoxide is generated in both AVA-MAPbI3 and MAPbI3 films, AVA located at grain boundaries is able to passivate surface defect sites, resulting in enhanced resistivity to oxygen induced degradation. These results are discussed in terms of their implications for the design of environmentally stable perovskite solar cells

    Impaired perception of facial motion in autism spectrum disorder

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    Copyright: © 2014 O’Brien et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.This article has been made available through the Brunel Open Access Publishing Fund.Facial motion is a special type of biological motion that transmits cues for socio-emotional communication and enables the discrimination of properties such as gender and identity. We used animated average faces to examine the ability of adults with autism spectrum disorders (ASD) to perceive facial motion. Participants completed increasingly difficult tasks involving the discrimination of (1) sequences of facial motion, (2) the identity of individuals based on their facial motion and (3) the gender of individuals. Stimuli were presented in both upright and upside-down orientations to test for the difference in inversion effects often found when comparing ASD with controls in face perception. The ASD group’s performance was impaired relative to the control group in all three tasks and unlike the control group, the individuals with ASD failed to show an inversion effect. These results point to a deficit in facial biological motion processing in people with autism, which we suggest is linked to deficits in lower level motion processing we have previously reported

    CD146 expression is associated with a poor prognosis in human breast tumors and with enhanced motility in breast cancer cell lines.

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    INTRODUCTION: Metastasis is a complex process involving loss of adhesion, migration, invasion and proliferation of cancer cells. Cell adhesion molecules play a pivotal role in this phenomenon by regulating cell-cell and cell-matrix interactions. CD146 (MCAM) is associated with an advanced tumor stage in melanoma, prostate cancer and ovarian cancer. Studies of CD146 expression and function in breast cancer remain scarce except for a report concluding that CD146 could act as a tumor suppressor in breast carcinogenesis. METHODS: To resolve these apparent discrepancies in the role of CD146 in tumor cells, we looked at the association of CD146 expression with histoclinical features in human primary breast cancers using DNA and tissue microarrays. By flow cytometry, we characterized CD146 expression on different breast cancer cell lines. Using siRNA or shRNA technology, we studied functional consequences of CD146 downmodulation of MDA-MB-231 cells in migration assays. Wild-type, mock-transfected and downmodulated transfected cells were profiled using whole-genome DNA microarrays to identify genes whose expression was modified by CD146 downregulation. RESULTS: Microarray studies revealed the association of higher levels of CD146 with histoclinical features that belong to the basal cluster of human tumors. Expression of CD146 protein on epithelial cells was detected in a small subset of cancers with histoclinical features of basal tumors. CD146+ cell lines displayed a mesenchymal phenotype. Downmodulation of CD146 expression in the MDA-MB-231 cell line resulted in downmodulation of vimentin, as well as of a set of genes that include both genes associated with a poor prognosis in a variety of cancers and genes known to promote cell motility. In vitro functional assays revealed decreased migration abilities associated with decreased CD146 expression. CONCLUSIONS: In addition to its expression in the vascular compartment, CD146 is expressed on a subset of epithelial cells in malignant breast. CD146 may directly or indirectly contribute to tumor aggressiveness by promoting malignant cell motility. Changes in molecular signatures following downmodulation of CD146 expression suggest that CD146 downmodulation is associated with the reversal of several biological characteristics associated with epithelial to mesenchymal transition, and the phenomenon associated with the metastatic process.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Genomic aberrations relate early and advanced stage ovarian cancer

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    Background Because of the distinct clinical presentation of early and advanced stage ovarian cancer, we aim to clarify whether these disease entities are solely separated by time of diagnosis or whether they arise from distinct molecular events. Methods Sixteen early and sixteen advanced stage ovarian carcinomas, matched for histological subtype and differentiation grade, were included. Genomic aberrations were compared for each early and advanced stage ovarian cancer by array comparative genomic hybridization. To study how the aberrations correlate to the clinical characteristics of the tumors we clustered tumors based on the genomic aberrations. Results The genomic aberration patterns in advanced stage cancer equalled those in early stage, but were more frequent in advanced stage (p=0.012). Unsupervised clustering based on genomic aberrations yielded two clusters that significantly discriminated early from advanced stage (p= 0.001), and that did differ significantly in survival (p= 0.002). These clusters however did give a more accurate prognosis than histological subtype or differentiation grade. Conclusion This study indicates that advanced stage ovarian cancer either progresses from early stage or from a common precursor lesion but that they do not arise from distinct carcinogenic molecular events. Furthermore, we show that array comparative genomic hybridization has the potential to identify clinically distinct patients

    Seroprevalence of Antibodies against Anisakis simplex Larvae among Health-Examined Residents in Three Hospitals of Southern Parts of Korea

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    The present study was performed to estimate the seroprevalence of larval Anisakis simplex infection among the residents health-examined in 3 hospitals in southern parts of Korea. A total of 498 serum samples (1 serum per person) were collected in 3 hospitals in Busan Metropolitan city, Masan city, and Geoje city in Gyeongsangnam-do (Province) and were examined by IgE-ELISA and IgE-western blotting with larval A. simplex crude extract and excretory-secretory products (ESP). The prevalence of antibody positivity was 5.0% and 6.6% with ELISA against crude extracts and ESP, respectively. It was also revealed that infection occurred throughout all age groups and higher in females than in males. A specific protein band of 130 kDa was detected from 10 patients with western blot analysis against crude extract and ESP among those who showed positive results by ELISA. Our study showed for the first time the seroprevalence of anisakiasis in Korea. The allergen of 130 kDa can be a candidate for serologic diagnosis of anisakiasis

    Allelic imbalances of chromosomes 8p and 18q and their roles in distant relapse of early stage, node-negative breast cancer

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    INTRODUCTION: Identification of breast cancer patients at risk for postoperative distant relapse is an important clinical issue. Existing pathological markers can predict disease recurrence only to a certain extent, and there is a need for more accurate predictors. METHODS: Using 'counting alleles', a novel experimental method, we determined allelic status of chromosomes 8p and 18q in a case-control study with 65 early stage, node negative, invasive ductal carcinomas (IDCs). The association between allelic imbalance (AI) of both chromosomal markers and distant relapses was examined. RESULTS: Eighty percent of tumors contained 8pAI and sixty-eight percent of tumors contained 18qAI. However, none of the tumor samples retained both chromosome 8p and 18q alleles. More importantly, tumors with 8pAI but not 18qAI were more likely to have distant relapse compared to tumors with 18qAI but not 8pAI. CONCLUSION: Our finding suggests that differential allelic loss of chromosomes 8p and 18q may represent subtypes of early stage IDC with different tumor progression behaviors
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