Search results for "D region"

An edge-driven 3D region growing approach for upper airways morphology and volume evaluation in patients with Pierre Robin sequence

2016

In this paper, a semi-automatic approach for segmentation of the upper airways is proposed. The implemented approach uses an edge-driven 3D region-growing algorithm to segment ROIs and 3D volume-rendering technique to reconstruct the 3D model of the upper airways. This method can be used to integrate information inside a medical decision support system, making it possible to enhance medical evaluation. The effectiveness of the proposed segmentation approach was evaluated using Jaccard (92.1733%) and dice (94.6441%) similarity indices and specificity (96.8895%) and sensitivity (97.6682%) rates. The proposed method achieved an average computation time reduced by a 16x factor with respect to m…

Post-Transcriptional Regulation of Iron Homeostasis in Saccharomyces cerevisiae

2013

Iron is an essential micronutrient for all eukaryotic organisms because it participates as a redox cofactor in a wide variety of biological processes. Recent studies in Saccharomyces cerevisiae have shown that in response to iron deficiency, an RNA-binding protein denoted Cth2 coordinates a global metabolic rearrangement that aims to optimize iron utilization. The Cth2 protein contains two Cx8Cx5Cx3H tandem zinc fingers (TZFs) that specifically bind to adenosine/uridine-rich elements within the 3' untranslated region of many mRNAs to promote their degradation. The Cth2 protein shuttles between the nucleus and the cytoplasm. Once inside the nucleus, Cth2 binds target mRNAs and stimulate…

El régimen jurídico de la rehabilitación urbana

1996

An improvement of ComiR algorithm for microRNA target prediction by exploiting coding region sequences of mRNAs

2020

AbstractMicroRNA are small non-coding RNAs that post-transcriptionally regulate the expression levels of messenger RNAs. MicroRNA regulation activity depends on the recognition of binding sites located on mRNA molecules. ComiR is a web tool realized to predict the targets of a set of microRNAs, starting from their expression profile. ComiR was trained with the information regarding binding sites in the 3’utr region, by using a reliable dataset containing the targets of endogenously expressed microRNA in D. melanogaster S2 cells. This dataset was obtained by comparing the results from two different experimental approaches, i.e., inhibition, and immunoprecipitation of the AGO1 protein--a comp…

Relief of microRNA-Mediated Translational Repression in Human Cells Subjected to Stress

2006

SummaryIn metazoans, most microRNAs imperfectly base-pair with the 3′ untranslated region (3′UTR) of target mRNAs and prevent protein accumulation by either repressing translation or inducing mRNA degradation. Examples of specific mRNAs undergoing microRNA-mediated repression are numerous, but whether the repression is a reversible process remains largely unknown. Here we show that cationic amino acid transporter 1 (CAT-1) mRNA and reporters bearing its 3′UTR can be relieved from the microRNA miR-122-induced inhibition in human hepatocarcinoma cells subjected to different stress conditions. The derepression of CAT-1 mRNA is accompanied by its release from cytoplasmic processing bodies and i…

Thymidylate synthase gene promoter polymorphisms are associated with TSmRNA expressions but not with microsatellite instability in colorectal cancer

2005

Abstract BACKGROUND: Microsatellite instability (MSI) is a biological characteristic of most tumours, being involved in 85% of hereditary non-polyposis colorectal cancer (HNPCC). It also occurs in 10-15% of sporadic colorectal cancers (CRC). HNPCC appears to be caused by germline mutations in mismatch repair (MMR) genes, which are responsible for repairing single base-pair mismatches. MSI is also associated with a better response of CRC to adjuvant chemotherapy with fluoropyrimidines. We investigated any relationship between the MSI status and the TSmRNA expression, the polymorphisms of 5-Fluorouracil (5-FU cellular target, the enzyme thymidylate synthase (TS) and TS expression evaluated by…

Variable maternal methylation overlapping the nc886/vtRNA2-1 locus is locked between hypermethylated repeats and is frequently altered in cancer.

2014

Cancer is as much an epigenetic disease as a genetic one; however, the interplay between these two processes is unclear. Recently, it has been shown that a large proportion of DNA methylation variability can be explained by allele-specific methylation (ASM), either at classical imprinted loci or those regulated by underlying genetic variants. During a recent screen for imprinted differentially methylated regions, we identified the genomic interval overlapping the non-coding nc886 RNA (previously known as vtRNA2-1) as an atypical ASM that shows variable levels of methylation, predominantly on the maternal allele in many tissues. Here we show that the nc886 interval is the first example of a …

Quantitative methylation analysis of developmentally important genes in human pregnancy losses after ART and spontaneous conception.

2009

To study possible effects of assisted reproductive technologies (ART) on epigenetic reprogramming, we have analyzed the DNA methylation levels of differentially methylated regions (DMRs) of seven imprinted genes (H19, MEG3, LIT1, MEST, NESP55, PEG3 and SNRPN) as well as the promoter regions of the pluripotency gene NANOG and the tumor suppressor gene APC in chorionic villus samples (CVS) of 42 spontaneous miscarriages and stillbirths after ART and 29 abortions/stillbirths after spontaneous conception. We did not find an increased rate of faulty methylation patterns after ART, but significant and trend differences (ROC curve analysis, Wilcoxon test) in the methylation levels of LIT1 (P = 0.0…

MicroRNA hsa-miR-4717-5p regulates RGS2 and may be a risk factor for anxiety-related traits

2015

Regulator of G-protein Signaling 2 (RGS2) is a key regulator of G-protein-coupled signaling pathways involved in fear and anxiety. Data from rodent models and genetic analysis of anxiety-related traits and disorders in humans suggest down-regulation of RGS2 expression to be a risk factor for anxiety. Here we investigated, whether genetic variation in microRNAs mediating posttranscriptional down-regulation of RGS2 may be a risk factor for anxiety as well. 75 microRNAs predicted to regulate RGS2 were identified by four bioinformatic algorithms and validated experimentally by luciferase reporter gene assays. Specificity was confirmed for six microRNAs (hsa-miR-1271-5p, hsa-miR-22-3p, hsa-miR-3…

Analysis of genetic variations of protein tyrosine kinase fyn and their association with alcohol dependence in two independent cohorts.

2003

Abstract Background Decreased sensitivity to and increased tolerance for the effects of alcohol is a phenotype, which was shown to be associated with an increased risk for alcoholism in humans and was observed in protein tyrosine kinase (PTK) fyn knockout mice. Methods We performed an association study of genetic variations of PTK fyn in 430 alcohol-dependent patients and 365 unrelated control subjects from two independent samples. Results In a combined analysis, we found an association of alcohol dependence with the single nucleotide polymorphism (SNP) T137346C in the 5′ untranslated region (UTR) of the gene. A relevant association could be excluded for the remaining two informative SNPs. …