130 research outputs found

    Preface

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    Off-nuclear star formation and obscured activity in the luminous infrared galaxy NGC 2623

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    New optical Hubble Space Telescope (HST), Spitzer Space Telescope, and XMM observations of the luminous infrared galaxy (LIRG) NGC 2623 are presented. This galaxy was observed as part of the Great Observatories All-sky LIRG Survey (GOALS). The prominent 3.2 kpc southern extension to the nucleus has been resolved by HST observations into ~100 star clusters, making it one of the richest off-nuclear concentrations of bright clusters observed in GOALS. The clusters have M_(F555W) ~-6.6 to -12.6 mag, which is within the magnitude range of Antennae galaxy clusters and in excess of 30 Doradus clusters at the high end. Their optical colors are primarily consistent with ages of ~1–100 Myr. Archival GALEX data show the off-nuclear region to be extremely bright in the far-ultraviolet, being equivalent in luminosity to the resolved nuclear region at 0.15 µm, but becoming less energetically significant at increasing wavelengths. In addition, [Ne v] 14.3 µm emission is detected with Spitzer IRS, confirming the inference from the X-ray and radio data that an active galactic nucleus (AGN) is present. Thus, the off-nuclear optical clusters are associated with a secondary burst of activity corresponding to a star formation rate ~0.1–0.2 M⊙ yr^(-1); the bulk of infrared (and thus bolometric) luminosity is generated via star formation and an AGN embedded behind dust within the inner kiloparsec of the system. If the infrared luminosity is primarily reprocessed starlight, the off-nuclear starburst accounts for <1% of the present star formation in NGC 2623

    A multimodal iPSC platform for cystic fibrosis drug testing

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    Cystic fibrosis is a monogenic lung disease caused by dysfunction of the cystic fibrosis transmembrane conductance regulator anion channel, resulting in significant morbidity and mortality. The progress in elucidating the role of CFTR using established animal and cell-based models led to the recent discovery of effective modulators for most individuals with CF. However, a subset of individuals with CF do not respond to these modulators and there is an urgent need to develop novel therapeutic strategies. In this study, we generate a panel of airway epithelial cells using induced pluripotent stem cells from individuals with common or rare CFTR variants representative of three distinct classes of CFTR dysfunction. To measure CFTR function we adapt two established in vitro assays for use in induced pluripotent stem cell-derived airway cells. In both a 3-D spheroid assay using forskolin-induced swelling as well as planar cultures composed of polarized mucociliary airway epithelial cells, we detect genotype-specific differences in CFTR baseline function and response to CFTR modulators. These results demonstrate the potential of the human induced pluripotent stem cell platform as a research tool to study CF and in particular accelerate therapeutic development for CF caused by rare variants

    A Push-Pull System to Reduce House Entry of Malaria Mosquitoes.

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    Mosquitoes are the dominant vectors of pathogens that cause infectious diseases such as malaria, dengue, yellow fever and filariasis. Current vector control strategies often rely on the use of pyrethroids against which mosquitoes are increasingly developing resistance. Here, a push-pull system is presented, that operates by the simultaneous use of repellent and attractive volatile odorants. Experiments were carried out in a semi-field set-up: a traditional house which was constructed inside a screenhouse. The release of different repellent compounds, para-menthane-3,8-diol (PMD), catnip oil e.o. and delta-undecalactone, from the four corners of the house resulted in significant reductions of 45% to 81.5% in house entry of host-seeking malaria mosquitoes. The highest reductions in house entry (up to 95.5%), were achieved by simultaneously repelling mosquitoes from the house (push) and removing them from the experimental set-up using attractant-baited traps (pull). The outcome of this study suggests that a push-pull system based on attractive and repellent volatiles may successfully be employed to target mosquito vectors of human disease. Reductions in house entry of malaria vectors, of the magnitude that was achieved in these experiments, would likely affect malaria transmission. The repellents used are non-toxic and can be used safely in a human environment. Delta-undecalactone is a novel repellent that showed higher effectiveness than the established repellent PMD. These results encourage further development of the system for practical implementation in the field

    Microarray gene expression profiling and analysis in renal cell carcinoma

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    BACKGROUND: Renal cell carcinoma (RCC) is the most common cancer in adult kidney. The accuracy of current diagnosis and prognosis of the disease and the effectiveness of the treatment for the disease are limited by the poor understanding of the disease at the molecular level. To better understand the genetics and biology of RCC, we profiled the expression of 7,129 genes in both clear cell RCC tissue and cell lines using oligonucleotide arrays. METHODS: Total RNAs isolated from renal cell tumors, adjacent normal tissue and metastatic RCC cell lines were hybridized to affymatrix HuFL oligonucleotide arrays. Genes were categorized into different functional groups based on the description of the Gene Ontology Consortium and analyzed based on the gene expression levels. Gene expression profiles of the tissue and cell line samples were visualized and classified by singular value decomposition. Reverse transcription polymerase chain reaction was performed to confirm the expression alterations of selected genes in RCC. RESULTS: Selected genes were annotated based on biological processes and clustered into functional groups. The expression levels of genes in each group were also analyzed. Seventy-four commonly differentially expressed genes with more than five-fold changes in RCC tissues were identified. The expression alterations of selected genes from these seventy-four genes were further verified using reverse transcription polymerase chain reaction (RT-PCR). Detailed comparison of gene expression patterns in RCC tissue and RCC cell lines shows significant differences between the two types of samples, but many important expression patterns were preserved. CONCLUSIONS: This is one of the initial studies that examine the functional ontology of a large number of genes in RCC. Extensive annotation, clustering and analysis of a large number of genes based on the gene functional ontology revealed many interesting gene expression patterns in RCC. Most notably, genes involved in cell adhesion were dominantly up-regulated whereas genes involved in transport were dominantly down-regulated. This study reveals significant gene expression alterations in key biological pathways and provides potential insights into understanding the molecular mechanism of renal cell carcinogenesis
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