110 research outputs found

    Cryptic Torrent Frogs of Myanmar: An Examination of the Amolops marmoratus Species Complex with the Resurrection of Amolops afghanus and the identification of a New Species

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    Cataloged from PDF version of article.We investigated diversity in the Amolops marmoratus species complex within Myanmar using both molecular and morphological characters from recently collected specimens. Based on congruence between multivariate analyses of quantitative morphological characters and phylogenetic analyses of nucleotide variation in the 16S ribosomal gene conducted on 43 out of 182 frogs examined, we recognize A. marmoratus for specimens from the states of Mon and Shan and northern Tanintharyi Division and designate a neotype for this species; resurrect A. afghanus (Gnther, 1858) from synonymy with A. marmoratus for specimens from the northern state of Kachin and designate a lectotype for this species; recognize A. panhai for specimens from Tanintharyi, a new country record; and describe a new species for specimens from the western states of Chin and Rakhine, and Sagaing Division. Š 2012 by the American Society of Ichthyologists and Herpetologists

    mESAdb: microRNA expression and sequence analysis database

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    Cataloged from PDF version of article.microRNA expression and sequence analysis database (http://konulab.fen.bilkent.edu.tr/mirna/) (mESAdb) is a regularly updated database for the multivariate analysis of sequences and expression of microRNAs from multiple taxa. mESAdb is modular and has a user interface implemented in PHP and JavaScript and coupled with statistical analysis and visualization packages written for the R language. The database primarily comprises mature microRNA sequences and their target data, along with selected human, mouse and zebrafish expression data sets. mESAdb analysis modules allow (i) mining of microRNA expression data sets for subsets of microRNAs selected manually or by motif; (ii) pair-wise multivariate analysis of expression data sets within and between taxa; and (iii) association of microRNA subsets with annotation databases, HUGE Navigator, KEGG and GO. The use of existing and customized R packages facilitates future addition of data sets and analysis tools. Furthermore, the ability to upload and analyze user-specified data sets makes mESAdb an interactive and expandable analysis tool for microRNA sequence and expression data

    School wellbeing among children in grades 1 - 10

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    <p>Abstract</p> <p>Background</p> <p>Determinants of children's school wellbeing have not been extensively studied. In this cross-sectional study of school children we assessed how factors assumed to promote wellbeing and factors assumed to adversely influence wellbeing were associated with self-reported wellbeing in school.</p> <p>Methods</p> <p>Children from five schools, 230 boys and 189 girls in grades 1-10, responded to the same set of questions. We used proportional odds logistic regression to assess the associations of promoting and restraining factors with school wellbeing.</p> <p>Results</p> <p>In a multivariable analysis, degree of school wellbeing in boys was strongly and positively related to enjoying school work (odds ratio, 3.84, 95% CI 2.38 to 6.22) and receiving necessary help (odds ratio, 3.55, 95% CI 2.17 to 5.80) from teachers. In girls, being bothered during lessons was strongly and negatively associated with school wellbeing (odds ratio, 0.43, 95% CI 0.22 to 0.85).</p> <p>Conclusions</p> <p>Different factors may determine school wellbeing in boys and girls, but for both genders, factors relevant for lessons may be more important than factors related to recess. Especially in boys, the student-teacher relationship may be of particular importance.</p

    Cloning and expression profile of FLT3 gene during progenitor cell-dependent liver regeneration

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    Background and Aim: The liver has a unique capacity to regenerate upon exposure to viral infections, toxic reactions and cancer formation. Liver regeneration is a complex phenomenon in which several factors participate during its onset. Cellular proliferation is an important component of this process and the factors that regulate this proliferation have a vital role. FLT3, a well-known hematopoietic stem cell and hepatic lineage surface marker, is involved in proliferative events of hematopoietic stem cells. However, its contribution to liver regeneration is not known. Therefore, the aim of this study was to clone and examine the role of FLT3 during liver regeneration in rats. Methods: Partial cDNA of rat homolog of FLT3 gene was cloned from thymus and the tissue specific expression of this gene at mRNA and protein levels was examined by RT-PCR and Western blot. After treating with 2-AAF and performing hepatectomy in rats to induce progenitor-dependent liver regeneration, the mRNA and protein expression profile of FLT3 was investigated by real-time PCR and Western blot during liver regeneration. In addition, cellular localization of FLT3 protein was determined by immunohistochemistry. Results: The results indicated that rat FLT3 cDNA has high homology with mouse and human FLT3 cDNA. It was also found that FLT3 is expressed in most of the rat tissues and during liver regeneration. In addition, its intracellular localization is altered during the late stages of liver regeneration. Conclusion: The FLT3 receptor is activated at the late stages of liver regeneration and participates in the proliferation response that is observed during progenitor-dependent liver regeneration. Š 2006 The Authors

    Aging alters the molecular dynamics of synapses in a sexually dimorphic pattern in zebrafish (Danio rerio)

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    The zebrafish has become a popular model for studying normal brain aging due to its large fecundity, conserved genome, and available genetic tools; but little data exists about neurobiological age-related alterations. The current study tested the hypothesis of an association between brain aging and synaptic protein loss across males and females. Western blot analysis of synaptophysin (SYP), a presynaptic vesicle protein, and postsynaptic density-95 (PSD-95) and gephyrin (GEP), excitatory and inhibitory postsynaptic receptor-clustering proteins, respectively, was performed in young, middle-aged, and old male and female zebrafish (Danio rerio) brains. Univariate and multivariate analyses demonstrated that PSD-95 significantly increased in aged females and SYP significantly decreased in males, but GEP was stable. Thus, these key synaptic proteins vary across age in a sexually dimorphic manner, which has been observed in other species, and these consequences may represent selective vulnerabilities for aged males and females. These data expand our knowledge of normal aging in zebrafish, as well as further establish this model as an appropriate one for examining human brain aging. Š 2017 Elsevier Inc

    Genome-Wide Transcriptional Reorganization Associated with Senescence-to-Immortality Switch during Human Hepatocellular Carcinogenesis

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    Cataloged from PDF version of article.Senescence is a permanent proliferation arrest in response to cell stress such as DNA damage. It contributes strongly to tissue aging and serves as a major barrier against tumor development. Most tumor cells are believed to bypass the senescence barrier (become "immortal") by inactivating growth control genes such as TP53 and CDKN2A. They also reactivate telomerase reverse transcriptase. Senescence-to-immortality transition is accompanied by major phenotypic and biochemical changes mediated by genome-wide transcriptional modifications. This appears to happen during hepatocellular carcinoma (HCC) development in patients with liver cirrhosis, however, the accompanying transcriptional changes are virtually unknown. We investigated genome-wide transcriptional changes related to the senescence-to-immortality switch during hepatocellular carcinogenesis. Initially, we performed transcriptome analysis of senescent and immortal clones of Huh7 HCC cell line, and identified genes with significant differential expression to establish a senescence-related gene list. Through the analysis of senescence-related gene expression in different liver tissues we showed that cirrhosis and HCC display expression patterns compatible with senescent and immortal phenotypes, respectively; dysplasia being a transitional state. Gene set enrichment analysis revealed that cirrhosis/senescence-associated genes were preferentially expressed in non-tumor tissues, less malignant tumors, and differentiated or senescent cells. In contrast, HCC/immortality genes were up-regulated in tumor tissues, or more malignant tumors and progenitor cells. In HCC tumors and immortal cells genes involved in DNA repair, cell cycle, telomere extension and branched chain amino acid metabolism were up-regulated, whereas genes involved in cell signaling, as well as in drug, lipid, retinoid and glycolytic metabolism were down-regulated. Based on these distinctive gene expression features we developed a 15-gene hepatocellular immortality signature test that discriminated HCC from cirrhosis with high accuracy. Our findings demonstrate that senescence bypass plays a central role in hepatocellular carcinogenesis engendering systematic changes in the transcription of genes regulating DNA repair, proliferation, differentiation and metabolism

    Quantification of SLIT-ROBO transcripts in hepatocellular carcinoma reveals two groups of genes with coordinate expression

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    <p>Abstract</p> <p>Background</p> <p>SLIT-ROBO families of proteins mediate axon pathfinding and their expression is not solely confined to nervous system. Aberrant expression of <it>SLIT-ROBO </it>genes was repeatedly shown in a wide variety of cancers, yet data about their collective behavior in hepatocellular carcinoma (HCC) is missing. Hence, we quantified <it>SLIT-ROBO </it>transcripts in HCC cell lines, and in normal and tumor tissues from liver.</p> <p>Methods</p> <p>Expression of <it>SLIT-ROBO </it>family members was quantified by real-time qRT-PCR in 14 HCC cell lines, 8 normal and 35 tumor tissues from the liver. ANOVA and Pearson's correlation analyses were performed in R environment, and different clinicopathological subgroups were pairwise compared in Minitab. Gene expression matrices of cell lines and tissues were analyzed by Mantel's association test.</p> <p>Results</p> <p>Genewise hierarchical clustering revealed two subgroups with coordinate expression pattern in both the HCC cell lines and tissues: <it>ROBO1</it>, <it>ROBO2</it>, <it>SLIT1 </it>in one cluster, and <it>ROBO4</it>, <it>SLIT2</it>, <it>SLIT3 </it>in the other, respectively. Moreover, <it>SLIT-ROBO </it>expression predicted <it>AFP</it>-dependent subgrouping of HCC cell lines, but not that of liver tissues. <it>ROBO1 </it>and <it>ROBO2 </it>were significantly up-regulated, whereas <it>SLIT3 </it>was significantly down-regulated in cell lines with high-<it>AFP </it>background. When compared to normal liver tissue, <it>ROBO1 </it>was found to be significantly overexpressed, while <it>ROBO4 </it>was down-regulated in HCC. We also observed that <it>ROBO1 </it>and <it>SLIT2 </it>differentiated histopathological subgroups of liver tissues depending on both tumor staging and differentiation status. However, <it>ROBO4 </it>could discriminate poorly differentiated HCC from other subgroups.</p> <p>Conclusion</p> <p>The present study is the first in comprehensive and quantitative evaluation of <it>SLIT-ROBO </it>family gene expression in HCC, and suggests that the expression of <it>SLIT-ROBO </it>genes is regulated in hepatocarcinogenesis. Our results implicate that <it>SLIT-ROBO </it>transcription profile is bi-modular in nature, and that each module shows intrinsic variability. We also provide quantitative evidence for potential use of <it>ROBO1</it>, <it>ROBO4 </it>and <it>SLIT2 </it>for prediction of tumor stage and differentiation status.</p

    A combined ULBP2 and SEMA5A expression signature as a prognostic and predictive biomarker for colon cancer

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    Background: Prognostic biomarkers for cancer have the power to change the course of disease if they add value beyond known prognostic factors, if they can help shape treatment protocols, and if they are reliable. The aim of this study was to identify such biomarkers for colon cancer and to understand the molecular mechanisms leading to prognostic stratifications based on these biomarkers. Methods and Findings: We used an in house R based script (SSAT) for the in silico discovery of stage-independent prognostic biomarkers using two cohorts, GSE17536 and GSE17537, that include 177 and 55 colon cancer patients, respectively. This identified 2 genes, ULBP2 and SEMA5A, which when used jointly, could distinguish patients with distinct prognosis. We validated our findings using a third cohort of 48 patients ex vivo. We find that in all cohorts, a combined ULBP2/SEMA5A classification (SU-GIB) can stratify distinct prognostic sub-groups with hazard ratios that range from 2.4 to 4.5 (p=0.01) when overall- or cancer-specific survival is used as an end-measure, independent of confounding prognostic parameters. In addition, our preliminary analyses suggest SU-GIB is comparable to Oncotype DX colon(Ž) in predicting recurrence in two different cohorts (HR: 1.5-2; p=0.02). SU-GIB has potential as a companion diagnostic for several drugs including the PI3K/mTOR inhibitor BEZ235, which are suitable for the treatment of patients within the bad prognosis group. We show that tumors from patients with worse prognosis have low EGFR autophosphorylation rates, but high caspase 7 activity, and show upregulation of pro-inflammatory cytokines that relate to a relatively mesenchymal phenotype. Conclusions: We describe two novel genes that can be used to prognosticate colon cancer and suggest approaches by which such tumors can be treated. We also describe molecular characteristics of tumors stratified by the SU-GIB signature. Š Ivyspring International Publisher

    Transcriptome map of mouse isochores

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    <p>Abstract</p> <p>Background</p> <p>The availability of fully sequenced genomes and the implementation of transcriptome technologies have increased the studies investigating the expression profiles for a variety of tissues, conditions, and species. In this study, using RNA-seq data for three distinct tissues (brain, liver, and muscle), we investigate how base composition affects mammalian gene expression, an issue of prime practical and evolutionary interest.</p> <p>Results</p> <p>We present the transcriptome map of the mouse isochores (DNA segments with a fairly homogeneous base composition) for the three different tissues and the effects of isochores' base composition on their expression activity. Our analyses also cover the relations between the genes' expression activity and their localization in the isochore families.</p> <p>Conclusions</p> <p>This study is the first where next-generation sequencing data are used to associate the effects of both genomic and genic compositional properties to their corresponding expression activity. Our findings confirm previous results, and further support the existence of a relationship between isochores and gene expression. This relationship corroborates that isochores are primarily a product of evolutionary adaptation rather than a simple by-product of neutral evolutionary processes.</p
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