188 research outputs found

    A Transcriptomic Signature of Mouse Liver Progenitor Cells

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    Liver progenitor cells (LPCs) can proliferate extensively, are able to differentiate into hepatocytes and cholangiocytes, and contribute to liver regeneration. The presence of LPCs, however, often accompanies liver disease and hepatocellular carcinoma (HCC), indicating that they may be a cancer stem cell. Understanding LPC biology and establishing a sensitive, rapid, and reliable method to detect their presence in the liver will assist diagnosis and facilitate monitoring of treatment outcomes in patients with liver pathologies. A transcriptomic meta-analysis of over 400 microarrays was undertaken to compare LPC lines against datasets of muscle and embryonic stem cell lines, embryonic and developed liver (DL), and HCC. Three gene clusters distinguishing LPCs from other liver cell types were identified. Pathways overrepresented in these clusters denote the proliferative nature of LPCs and their association with HCC. Our analysis also revealed 26 novel markers, LPC markers, including Mcm2 and Ltbp3, and eight known LPC markers, including M2pk and Ncam. These markers specified the presence of LPCs in pathological liver tissue by qPCR and correlated with LPC abundance determined using immunohistochemistry. These results showcase the value of global transcript profiling to identify pathways and markers that may be used to detect LPCs in injured or diseased liver

    Interferometric Observations of RS Ophiuchi and the Origin of the Near-IR Emission

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    We report observations of the recurrent nova RS Oph using long-baseline near-IR interferometry. We are able to resolve emission from the nova for several weeks after the February 2006 outburst. The near-IR source initially expands to a size of approximately 5 milli-arcseconds. However, beginning around day 10 the IR source appears to begin to shrink, reaching approximately 2 milli-arcseconds by day 100. We combine our measured angular diameters with previously available interferometric and photometric data to derive an emission measure for the source, and hence are able to determine the mass-loss rate of the nova in the days following the outburst.Comment: 17 pages, 4 figures. Accepted for publication in Ap

    Quality of life in Maltese Adults with Congenital Heart Disease : a Second Look – An APPROACH-IS Substudy

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    Background A first quality of life (QOL) study among Maltese adults with congenital heart disease (ACHD) in 2016 found no significant differences when compared to the general population. The aims of the present study were to (1) compare QOL between Maltese and other European ACHD patients and (2) investigate medical predictors (i.e. number of surgical/non-surgical interventions, heart failure, arrhythmias, pacemaker/implantable cardioverter-defibrillator, cardiac hospitalisation during preceding year, follow-up frequency, other medical conditions, mood/anxiety/psychiatric disorders) of QOL in Maltese patients. Methods Data collected during \u201cAssessment of Patterns of Patient-Reported Outcomes in Adults with Congenital Heart disease\u2013International Study\u201d (APPROACH-IS) was used. QOL was measured using linear analog scale (LAS) and Satisfaction With Life Scale (SWLS). QOL in 109 Maltese and 1510 European participants was compared. Multivariable logistic regression was used to test the predictive value of medical factors on QOL in Maltese patients. Results There were no significant differences in QOL between the two cohorts [mean LAS Malta 80.51 (95% CI 77.96,83.07) vs. European 79.43 (95% CI 78.65,80.21) (p=0.776); mean SWLS Malta 26.00 (95% CI 24.94,27.06) vs. European 26.26 (95% CI 25.95,26.57) (p=0.288)] and no significant differences when cohorts were divided by gender and age. Only a mood/anxiety/other psychiatric disorder significantly predicted poorer QOL on both scales in Maltese patients (LAS ( f=-.389, p<0.001), SWLS ( f=-.352, p=0.001)). Conclusions Maltese ACHD patients have a good QOL comparable to that of European counterparts. Mood, anxiety and other psychiatric disorders can negatively impact Maltese patients\u2019 QOL. Better access to clinical psychology services should be ensured

    Rationale, design and methodology of APPROACH-IS II: International study of patient-reported outcomes and frailty phenotyping in adults with congenital heart disease.

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    In recent years, patient-reported outcomes (PROs) have received increasing prominence in cardiovascular research and clinical care. An understanding of the variability and global experience of PROs in adults with congenital heart disease (CHD), however, is still lacking. Moreover, information on epidemiological characteristics and the frailty phenotype of older adults with CHD is minimal. The APPROACH-IS II study was established to address these knowledge gaps. This paper presents the design and methodology of APPROACH-IS II. APPROACH-IS II is a cross-sectional global multicentric study that includes Part 1 (assessing PROs) and Part 2 (investigating the frailty phenotype of older adults). With 53 participating centers, located in 32 countries across six continents, the aim is to enroll 8000 patients with CHD. In Part 1, self-report surveys are used to collect data on PROs (e.g., quality of life, perceived health, depressive symptoms, autonomy support), and explanatory variables (e.g., social support, stigma, illness identity, empowerment). In Part 2, the cognitive functioning and frailty phenotype of older adults are measured using validated assessments. APPROACH-IS II will generate a rich dataset representing the international experience of individuals in adult CHD care. The results of this project will provide a global view of PROs and the frailty phenotype of adults with CHD and will thereby address important knowledge gaps. Undoubtedly, the project will contribute to the overarching aim of improving optimal living and care provision for adults with CHD

    The apoptotic response in HCT116BAX-/- cancer cells becomes rapidly saturated with increasing expression of a GFP-BAX fusion protein

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    Abstract Background Many chemotherapeutic agents promote tumor cell death by activating the intrinsic pathway of apoptosis. Intrinsic apoptosis involves permeabilization of the mitochondrial outer membrane and the release of cytochrome c, a process that is controlled by proteins of the BCL2 gene family. Chemoresistance is often associated with abnormalities in concentrations of BCL2 family proteins. Although stoichiometirc interactions between anti-apoptotic and BH3-only BCL2 family proteins have been well documented as affecting cell death, the association between changes in BAX concentration and intrinsic apoptosis are poorly understood. Methods Exogenous GFP-murine Bax fusion constructs were transfected into BAX-deficient HCT116 cells. To titrate the expression of the fusion protein, GFP-BAX was cloned into a tetracycline sensitive expression cassette and cotransfected with a plasmid expressing the rtTA transcription factor into HCT116 BAX-/- cells. Linear expression of the fusion gene was induced with doxycycline and monitored by quantitative PCR and immunoblotting. Cell death was assayed by DAPI staining cells after exposure to indomethacin, and scoring nuclei for condensed chromatin and fragmented nuclei. Results HCT116 BAX-/- cells were resistant to indomethacin, but susceptibility could be recovered in cells expressing a GFP-BAX fusion protein. Titration of GFP-BAX expression revealed that the concentration of BAX required to induce a saturating apoptosis response from baseline, was rapidly achieved. Increased levels of GFP-BAX were unable to stimulate higher levels of cell death. Examination of GFP-BAX distribution before and after indomethacin treatment indicated that BAX protein did not form aggregates when present at sub-lethal concentrations. Conclusion Within the limitations of this experimental system, BAX-dependent apoptosis in HCT116 cells exhibits an all-or-none response depending on the level of BAX protein present. The lack of BAX aggregation at sub-saturation levels suggests that the translocation step of BAX activation may be impaired

    How society’s negative view of videogames can discourage brands from sponsoring eSports

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    The purpose of this research was to identify the main motives that contribute to society’s negative view of videogames and that present a risk to the eSports sponsors’ image. To achieve this, an exploratory, qualitative, and integrative literature review was conducted. According to the theoretical data, there are four main reasons why society has a negative perception of videogames. It is commonly believed that: (1) gaming is an unproductive activity, (2) violent videogames incite aggressive behaviors, (3) videogames lead to gaming-addiction, and (4) eSports lead to eSports-related gambling addiction. However, while the literature presents convincing evidence that gaming can create addiction and that eSports can promote gambling addiction, there is no conclusive evidence to assume that violent videogames lead to aggressiveness and there is evidence showing that playing videogames can be a productive activity. Nevertheless, these four beliefs are a threat to the eSports sponsors’ image and may lead them to cancel their existing sponsorships or lead other brands to not want to sponsor eSports to prevent being associated with these negative notions. This research will help expand the minor literature on eSports sponsorships and advance the knowledge of why some eSports sponsorships are terminated and why some brands may be reluctant to sponsor eSports.info:eu-repo/semantics/publishedVersio

    Caspase-Dependent Inhibition of Mousepox Replication by gzmB

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    BACKGROUND: Ectromelia virus is a natural mouse pathogen, causing mousepox. The cytotoxic T (Tc) cell granule serine-protease, granzyme B, is important for its control, but the underlying mechanism is unknown. Using ex vivo virus immune Tc cells, we have previously shown that granzyme B is able to activate several independent pro-apoptotic pathways, including those mediated by Bid/Bak/Bax and caspases-3/-7, in target cells pulsed with Tc cell determinants. METHODS AND FINDINGS: Here we analysed the physiological relevance of those pro-apoptotic pathways in ectromelia infection, by incubating ectromelia-immune ex vivo Tc cells from granzyme A deficient (GzmB(+) Tc cells) or granzyme A and granzyme B deficient (GzmAxB(-/-) Tc cell) mice with ectromelia-infected target cells. We found that gzmB-induced apoptosis was totally blocked in ectromelia infected or peptide pulsed cells lacking caspases-3/-7. However ectromelia inhibited only partially apoptosis in cells deficient for Bid/Bak/Bax and not at all when both pathways were operative suggesting that the virus is able to interfere with apoptosis induced by gzmB in case not all pathways are activated. Importantly, inhibition of viral replication in vitro, as seen with wild type cells, was not affected by the lack of Bid/Bak/Bax but was significantly reduced in caspase-3/-7-deficient cells. Both caspase dependent processes were strictly dependent on gzmB, since Tc cells, lacking both gzms, neither induced apoptosis nor reduced viral titers. SIGNIFICANCE: Out findings present the first evidence on the biological importance of the independent gzmB-inducible pro-apoptotic pathways in a physiological relevant virus infection model

    The Apoptosome: Emerging Insights and New Potential Targets for Drug Design

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    Apoptosis plays a crucial role in tissue homeostasis, development and many diseases. The relevance of Apaf1, the molecular core of apoptosome, has been underlined in mitochondria-dependent apoptosis, which according to a growing body of evidence, is involved in various pathologies where the equilibrium of life-and-death is dysregulated, such as heart attack, stroke, liver failure, cancer and autoimmune diseases. Consequently, great interest has emerged in devising therapeutic strategies for regulating the key molecules involved in the life-and-death decision. Here we review recent progress in apoptosis-based pharmacological therapies and, in particular, we point out a possible role of the apoptosome as an emerging and promising pharmacological target

    The JAK-STAT Pathway Controls Plasmodium vivax Load in Early Stages of Anopheles aquasalis Infection

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    Malaria affects 300 million people worldwide every year and 450,000 in Brazil. In coastal areas of Brazil, the main malaria vector is Anopheles aquasalis, and Plasmodium vivax is responsible for the majority of malaria cases in the Americas. Insects possess a powerful immune system to combat infections. Three pathways control the insect immune response: Toll, IMD, and JAK-STAT. Here we analyze the immune role of the A. aquasalis JAK-STAT pathway after P. vivax infection. Three genes, the transcription factor Signal Transducers and Activators of Transcription (STAT), the regulatory Protein Inhibitors of Activated STAT (PIAS) and the Nitric Oxide Synthase enzyme (NOS) were characterized. Expression of STAT and PIAS was higher in males than females and in eggs and first instar larvae when compared to larvae and pupae. RNA levels for STAT and PIAS increased 24 and 36 hours (h) after P. vivax challenge. NOS transcription increased 36 h post infection (hpi) while this protein was already detected in some midgut epithelial cells 24 hpi. Imunocytochemistry experiments using specific antibodies showed that in non-infected insects STAT and PIAS were found mostly in the fat body, while in infected mosquitoes the proteins were found in other body tissues. The knockdown of STAT by RNAi increased the number of oocysts in the midgut of A. aquasalis. This is the first clear evidence for the involvement of a specific immune pathway in the interaction of the Brazilian malaria vector A. aquasalis with P. vivax, delineating a potential target for the future development of disease controlling strategies
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