919 research outputs found

    Characterising cancer-associated fibroblast heterogeneity in non-small cell lung cancer: a systematic review and meta-analysis.

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    Cancer-associated fibroblasts (CAFs) are a key component of the tumour microenvironment with evidence suggesting they represent a heterogeneous population. This study summarises the prognostic role of all proteins characterised in CAFs with immunohistochemistry in non-small cell lung cancer thus far. The functions of these proteins in cellular processes crucial to CAFs are also analysed. Five databases were searched to extract survival outcomes from published studies and statistical techniques, including a novel method, used to capture missing values from the literature. A total of 26 proteins were identified, 21 of which were combined into 7 common cellular processes key to CAFs. Quality assessments for sensitivity analyses were carried out for each study using the REMARK criteria whilst publication bias was assessed using funnel plots. Random effects models consistently identified the expression of podoplanin (Overall Survival (OS)/Disease-specific Survival (DSS), univariate analysis HR 2.25, 95% CIs 1.80-2.82) and Ξ±-SMA (OS/DSS, univariate analysis HR 2.11, 95% CIs 1.18-3.77) in CAFs as highly prognostic regardless of outcome measure or analysis method. Moreover, proteins involved in maintaining and generating the CAF phenotype (Ξ±-SMA, TGF-Ξ² and p-Smad2) proved highly significant after sensitivity analysis (HR 2.74, 95% CIs 1.74-4.33) supporting attempts at targeting this pathway for therapeutic benefit

    Single Cut Integration

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    We present an analytic technique for evaluating single cuts for one-loop integrands, where exactly one propagator is taken to be on shell. Our method extends the double-cut integration formalism of one-loop amplitudes to the single-cut case. We argue that single cuts give meaningful information about amplitudes when taken at the integrand level. We discuss applications to the computation of tadpole coefficients.Comment: v2: corrected typo in abstrac

    Engaging children in meaningful charity: opening-up the spaces within which children learn to give

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    This paper presents qualitative evidence from an in-depth, participative action research project with 150 children aged 4-8 years old, exploring their experiences, perceptions and preferences regarding charitable giving. Most children positively engage in charitable giving through home, school and their community, however less than 20% are aware of the cause area they are being asked to support, and most have little decision-making in their giving. Children’s willingness to engage increases when they critically examine the cause area and are facilitated to lead on giving decisions, often resulting in increased and sustained efforts to support cause areas that matter to them

    Pediatric resident and faculty attitudes toward self-assessment and self-directed learning: a cross-sectional study

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    <p>Abstract</p> <p>Background</p> <p>The development of self-assessment and self-directed learning skills is essential to lifelong learning and becoming an effective physician. Pediatric residents in the United States are now required to use Individualized Learning Plans (ILPs) to document self-assessment and self-directed learning. A better understanding of resident and faculty attitudes and skills about self-assessment and self-directed learning will allow more successful integration of lifelong learning into residency education. The objective of this study was to compare faculty and resident attitudes, knowledge and skills about self-assessment, self-directed learning and ILPs.</p> <p>Methods</p> <p>Survey of pediatric residents and faculty at a single institution. Respondents rated their attitudes, knowledge, and self-perceived skills surrounding self-assessment, self-directed learning and ILPs.</p> <p>Results</p> <p>Overall survey response rate was 81% (79/97); 100% (36/36) residents and 70% (43/61) faculty. Residents and faculty agreed that lifelong learning is a necessary part of being a physician. Both groups were comfortable with assessing their own strengths and weaknesses and developing specific goals to improve their own performance. However, residents were less likely than faculty to continuously assess their own performance (44% vs. 81%; p < 0.001) or continuously direct their own learning (53% vs. 86%; p < 0.001). Residents were more likely than faculty to believe that residents should be primarily responsible for directing their own learning (64% vs. 19%; p < 0.0001), but at the same time, more residents believed that assigned clinical (31% vs. 0%; p < 0.0001) or curricular (31% vs. 0%; p < 0.0001) experiences were sufficient to make them competent physicians. Interns were less likely than senior residents to have a good understanding of how to assess their own skills (8% vs. 58%; p = 0.004) or what it means to be a self-directed learner (50% vs. 83%; p = 0.04).</p> <p>Qualitative comments indicated that while ILPs have the potential to help learners develop individualized, goal-directed learning plans based on strengths and weaknesses, successful implementation will require dedicated time and resident and faculty development.</p> <p>Conclusion</p> <p>These findings suggest that training and experience are necessary for physicians to understand the role of self-directed learning in education. Deliberate practice, for example by requiring residents to use ILPs, may facilitate self-directed, lifelong learning.</p

    The RING-CH ligase K5 antagonizes restriction of KSHV and HIV-1 particle release by mediating ubiquitin-dependent endosomal degradation of tetherin

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    Tetherin (CD317/BST2) is an interferon-induced membrane protein that inhibits the release of diverse enveloped viral particles. Several mammalian viruses have evolved countermeasures that inactivate tetherin, with the prototype being the HIV-1 Vpu protein. Here we show that the human herpesvirus Kaposi's sarcoma-associated herpesvirus (KSHV) is sensitive to tetherin restriction and its activity is counteracted by the KSHV encoded RING-CH E3 ubiquitin ligase K5. Tetherin expression in KSHV-infected cells inhibits viral particle release, as does depletion of K5 protein using RNA interference. K5 induces a species-specific downregulation of human tetherin from the cell surface followed by its endosomal degradation. We show that K5 targets a single lysine (K18) in the cytoplasmic tail of tetherin for ubiquitination, leading to relocalization of tetherin to CD63-positive endosomal compartments. Tetherin degradation is dependent on ESCRT-mediated endosomal sorting, but does not require a tyrosine-based sorting signal in the tetherin cytoplasmic tail. Importantly, we also show that the ability of K5 to substitute for Vpu in HIV-1 release is entirely dependent on K18 and the RING-CH domain of K5. By contrast, while Vpu induces ubiquitination of tetherin cytoplasmic tail lysine residues, mutation of these positions has no effect on its antagonism of tetherin function, and residual tetherin is associated with the trans-Golgi network (TGN) in Vpu-expressing cells. Taken together our results demonstrate that K5 is a mechanistically distinct viral countermeasure to tetherin-mediated restriction, and that herpesvirus particle release is sensitive to this mode of antiviral inhibition

    Substance abuse and intimate partner violence: treatment considerations

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    Given the increased use of marital- and family-based treatments as part of treatment for alcoholism and other drug disorders, providers are increasingly faced with the challenge of addressing intimate partner violence among their patients and their intimate partners. Yet, effective options for clinicians who confront this issue are extremely limited. While the typical response of providers is to refer these cases to some form of batterers' treatment, three fundamental concerns make this strategy problematic: (1) most of the agencies that provide batterers' treatment only accept individuals who are legally mandated to complete their programs; (2) among programs that do accept nonmandated patients, most substance-abusing patients do not accept such referrals or drop out early in the treatment process; and (3) available evidence suggests these programs may not be effective in reducing intimate partner violence. Given these very significant concerns with the current referral approach, coupled with the high incidence of IPV among individuals entering substance abuse treatment, providers need to develop strategies for addressing IPV that can be incorporated and integrated into their base intervention packages

    Electrical Stimulation Influences Satellite Cell Proliferation and Apoptosis in Unloading-Induced Muscle Atrophy in Mice

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    Muscle atrophy caused by disuse is accompanied by adverse physiological and functional consequences. Satellite cells are the primary source of skeletal muscle regeneration. Satellite cell dysfunction, as a result of impaired proliferative potential and/or increased apoptosis, is thought to be one of the causes contributing to the decreased muscle regeneration capacity in atrophy. We have previously shown that electrical stimulation improved satellite cell dysfunction. Here we test whether electrical stimulation can also enhance satellite cell proliferative potential as well as suppress apoptotic cell death in disuse-induced muscle atrophy. Eight-week-old male BALB/c mice were subjected to a 14-day hindlimb unloading procedure. During that period, one limb (HU-ES) received electrical stimulation (frequency: 20 Hz; duration: 3 h, twice daily) while the contralateral limb served as control (HU). Immunohistochemistry and western blotting techniques were used to characterize specific proteins in cell proliferation and apoptosis. The HU-ES soleus muscles showed significant improvement in muscle mass, cross-sectional area, and peak tetanic force relative to the HU limb (p<0.05). The satellite cell proliferative activity as detected within the BrdU+/Pax7+ population was significantly higher (p<0.05). The apoptotic myonuclei (detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling) and the apoptotic satellite cells (detected by cleaved Poly [ADP-ribose] polymerase co-labeled with Pax7) were reduced (p<0.05) in the HU-ES limb. Furthermore the apoptosis-inducing factor and cleaved caspase-3 were down-regulated while the anti-apoptotic Bcl-2 protein was up-regulated (p<0.05), in the HU-ES limb. These findings suggest that the electrical stimulation paradigm provides an effective stimulus to rescue the loss of myonuclei and satellite cells in disuse muscle atrophy, thus maintaining a viable satellite cell pool for subsequent muscle regeneration. Optimization of stimulation parameters may enhance the outcome of the intervention

    Computational Integration of Homolog and Pathway Gene Module Expression Reveals General Stemness Signatures

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    The stemness hypothesis states that all stem cells use common mechanisms to regulate self-renewal and multi-lineage potential. However, gene expression meta-analyses at the single gene level have failed to identify a significant number of genes selectively expressed by a broad range of stem cell types. We hypothesized that stemness may be regulated by modules of homologs. While the expression of any single gene within a module may vary from one stem cell type to the next, it is possible that the expression of the module as a whole is required so that the expression of different, yet functionally-synonymous, homologs is needed in different stem cells. Thus, we developed a computational method to test for stem cell-specific gene expression patterns from a comprehensive collection of 49 murine datasets covering 12 different stem cell types. We identified 40 individual genes and 224 stemness modules with reproducible and specific up-regulation across multiple stem cell types. The stemness modules included families regulating chromatin remodeling, DNA repair, and Wnt signaling. Strikingly, the majority of modules represent evolutionarily related homologs. Moreover, a score based on the discovered modules could accurately distinguish stem cell-like populations from other cell types in both normal and cancer tissues. This scoring system revealed that both mouse and human metastatic populations exhibit higher stemness indices than non-metastatic populations, providing further evidence for a stem cell-driven component underlying the transformation to metastatic disease

    An evaluation of POSSUM and P-POSSUM scoring in predicting post-operative mortality in a level 1 critical care setting

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    Background POSSUM and P-POSSUM are used in the assessment of outcomes in surgical patients. Neither scoring systems’ accuracy has been established where a level 1 critical care facility (level 1 care ward) is available for perioperative care. We compared POSSUM and P-POSSUM predicted with observed mortality on a level 1 care ward. Methods A prospective, observational study was performed between May 2000 and June 2008. POSSUM and P-POSSUM scores were calculated for all postoperative patients who were admitted to the level 1 care ward. Data for post-operative mortality were obtained from hospital records for 2552 episodes of patient care. Observed vs expected mortality was compared using receiver operating characteristic (ROC) curves and the goodness of fit assessed using the Hosmer-Lemeshow equation. Results ROC curves show good discriminative ability between survivors and non-survivors for POSSUM and P-POSSUM. Physiological score had far higher discrimination than operative score. Both models showed poor calibration and poor goodness of fit (Hosmer-Lemeshow). Observed to expected (O:E) mortality ratio for POSSUM and P-POSSUM indicated significantly fewer than expected deaths in all deciles of risk. Conclusions Our data suggest a 30-60% reduction in O:E mortality. We suggest that the use of POSSUM models to predict mortality in patients admitted to level 1 care ward is inappropriate or that a recalibration of POSSUM is required to make it useful in a level 1 care ward setting

    The Deadly Chytrid Fungus: A Story of an Emerging Pathogen

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    [Extract] Emerging infectious diseases present a great challenge for the health of both humans and wildlife. The increasing prevalence of drug-resistant fungal pathogens in humans [1] and recent outbreaks of novel fungal pathogens in wildlife populations [2] underscore the need to better understand the origins and mechanisms of fungal pathogenicity. One of the most dramatic examples of fungal impacts on vertebrate populations is the effect of the amphibian disease chytridiomycosis, caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd).\ud Amphibians around the world are experiencing unprecedented population losses and local extinctions [3]. While there are multiple causes of amphibian declines, many catastrophic die-offs are attributed to Bd [4],[5]. The chytrid pathogen has been documented in hundreds of amphibian species, and reports of Bd's impact on additional species and in additional geographic regions are accumulating at an alarming rate (e.g., see http://www.spatialepidemiology.net/bd). Bd is a microbial, aquatic fungus with distinct life stages. The motile stage, called a zoospore, swims using a flagellum and initiates the colonization of frog skin. Within the host epidermal cells, a zoospore forms a spherical thallus, which matures and produces new zoospores by dividing asexually, renewing the cycle of infection when zoospores are released to the skin surface (Figure 1). Bd is considered an emerging pathogen, discovered and described only a decade ago [6],[7]. Despite intensive ecological study of Bd over the last decade, a number of unanswered questions remain. Here we summarize what has been recently learned about this lethal pathogen
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