2,352 research outputs found
Breast cancer cells stimulate osteoprotegerin (OPG) production by endothelial cells through direct cell contact
<p>Abstract</p> <p>Background</p> <p>Angiogenesis, the sprouting of capillaries from existing blood vessels, is central to tumour growth and progression, however the molecular regulation of this process remains to be fully elucidated. The secreted glycoprotein osteoprotegerin (OPG) is one potential pro-angiogenic factor, and clinical studies have demonstrated endothelial cells within a number of tumour types to express high levels of OPG compared to those in normal tissue. Additionally, OPG can increase endothelial cell survival, proliferation and migration, as well as induce endothelial cell tube formation <it>in vitro</it>. This study aims to elucidate the processes involved in the pro-angiogenic effects of OPG <it>in vitro</it>, and also how OPG levels may be regulated within the tumour microenvironment.</p> <p>Results</p> <p>It has previously been demonstrated that OPG can induce tube formation on growth factor reduced matrigel. In this study, we demonstrate that OPG enhances the pro-angiogenic effects of VEGF and that OPG does not stimulate endothelial cell tube formation through activation of the VEGFR2 receptor. We also show that cell contact between HuDMECs and the T47D breast cancer cell line increases endothelial cell OPG mRNA and protein secretion levels in <it>in vitro </it>co-cultures. These increases in endothelial cell OPG secretion were dependent on α<sub>ν</sub>β<sub>3 </sub>ligation and NFκB activation. In contrast, the pro-angiogenic factors VEGF, bFGF and TGFβ had no effect on HuDMEC OPG levels.</p> <p>Conclusion</p> <p>These findings suggest that the VEGF signalling pathway is not involved in mediating the pro-angiogenic effects of OPG on endothelial cells <it>in vitro</it>. Additionally, we show that breast cancer cells cause increased levels of OPG expression by endothelial cells, and that direct contact between endothelial cells and tumour cells is required in order to increase endothelial OPG expression and secretion. Stimulation of OPG secretion was shown to involve α<sub>ν</sub>β<sub>3 </sub>ligation and NFκB activation.</p
Hyaluronic Acid (HA) Receptors and the Motility of Schwann Cell(-Like) Phenotypes
The cluster of differentiation 44 (CD44) and the hyaluronan-mediated motility receptor (RHAMM), also known as CD168, are perhaps the most studied receptors for hyaluronic acid (HA); among their various functions, both are known to play a role in the motility of a number of cell types. In peripheral nerve regeneration, the stimulation of glial cell motility has potential to lead to better therapeutic outcomes, thus this study aimed to ascertain the presence of these receptors in Schwann cells (rat adult aSCs and neonatal nSCs) and to confirm their influence on motility. We included also a Schwann-like phenotype (dAD-MSCs) derived from adipose-derived mesenchymal stem cells (uAD-MSCs), as a possible basis for an autologous cell therapy. CD44 was expressed similarly in all cell types. Interestingly, uAD-MSCs were RHAMM(low), whereas both Schwann cells and dASCs turned out to be similarly RHAMM(high), and indeed antibody blockage of RHAMM effectively immobilized (in vitro scratch wound assay) all the RHAMM(high) Schwann(-like) types, but not the RHAMM(low) uAD-MSCs. Blocking CD44, on the other hand, affected considerably more uAD-MSCs than the Schwann(-like) cells, while the combined blockage of the two receptors immobilized all cells. The results therefore indicate that Schwann-like cells have a specifically RHAMM-sensitive motility, where the motility of precursor cells such as uAD-MSCs is CD44- but not RHAMM-sensitive; our data also suggest that CD44 and RHAMM may be using complementary motility-controlling circuits
Genome-wide linkage using the Social Responsiveness Scale in Utah autism pedigrees
<p>Abstract</p> <p>Background</p> <p>Autism Spectrum Disorder<b>s </b>(ASD) are phenotypically heterogeneous, characterized by impairments in the development of communication and social behaviour and the presence of repetitive behaviour and restricted interests. Dissecting the genetic complexity of ASD may require phenotypic data reflecting more detail than is offered by a categorical clinical diagnosis. Such data are available from the Social Responsiveness Scale (SRS) which is a continuous, quantitative measure of social ability giving scores that range from significant impairment to above average ability.</p> <p>Methods</p> <p>We present genome-wide results for 64 multiplex and extended families ranging from two to nine generations. SRS scores were available from 518 genotyped pedigree subjects, including affected and unaffected relatives. Genotypes from the Illumina 6 k single nucleotide polymorphism panel were provided by the Center for Inherited Disease Research. Quantitative and qualitative analyses were done using MCLINK, a software package that uses Markov chain Monte Carlo (MCMC) methods to perform multilocus linkage analysis on large extended pedigrees.</p> <p>Results</p> <p>When analysed as a qualitative trait, linkage occurred in the same locations as in our previous affected-only genome scan of these families, with findings on chromosomes 7q31.1-q32.3 [heterogeneity logarithm of the odds (HLOD) = 2.91], 15q13.3 (HLOD = 3.64), and 13q12.3 (HLOD = 2.23). Additional positive qualitative results were seen on chromosomes 6 and 10 in regions that may be of interest for other neuropsychiatric disorders. When analysed as a quantitative trait, results replicated a peak found in an independent sample using quantitative SRS scores on chromosome 11p15.1-p15.4 (HLOD = 2.77). Additional positive quantitative results were seen on chromosomes 7, 9, and 19.</p> <p>Conclusions</p> <p>The SRS linkage peaks reported here substantially overlap with peaks found in our previous affected-only genome scan of clinical diagnosis. In addition, we replicated a previous SRS peak in an independent sample. These results suggest the SRS is a robust and useful phenotype measure for genetic linkage studies of ASD. Finally, analyses of SRS scores revealed linkage peaks overlapping with evidence from other studies of neuropsychiatric diseases. The information available from the SRS itself may, therefore, reveal locations for autism susceptibility genes that would not otherwise be detected.</p
Cytokine responses in birds challenged with the human food-borne pathogen Campylobacter jejuni implies a Th17 response
Development of process orientated understanding of cytokine interactions within the gastrointestinal tract during an immune response to pathogens requires experimentation and statistical modelling. The immune response against pathogen challenge depends on the specific threat to the host. Here, we show that broiler chickens mount a breed-dependent immune response to Campylobacter jejuni infection in the caeca by analysing experimental data using frequentist and Bayesian structural equation models (SEM). SEM provides a framework by which cytokine interdependencies, based on prior knowledge, can be tested. In both breeds important cytokines including pro-inflammatory interleukin (IL)-1β, , IL-4, IL-17A, interferon (IFN)-γ and anti-inflammatory IL-10 and transforming growth factor (TGF)-β4 were expressed post-challenge. The SEM revealed a putative regulatory pathway illustrating a T helper (Th)17 response and regulation of IL-10, which is breed-dependent. The prominence of the Th17 pathway indicates the cytokine response aims to limit the invasion or colonization of an extracellular bacterial pathogen but the time-dependent nature of the response differs between breeds
Results from the centers for disease control and prevention's predict the 2013-2014 Influenza Season Challenge
Background: Early insights into the timing of the start, peak, and intensity of the influenza season could be useful in planning influenza prevention and control activities. To encourage development and innovation in influenza forecasting, the Centers for Disease Control and Prevention (CDC) organized a challenge to predict the 2013-14 Unites States influenza season. Methods: Challenge contestants were asked to forecast the start, peak, and intensity of the 2013-2014 influenza season at the national level and at any or all Health and Human Services (HHS) region level(s). The challenge ran from December 1, 2013-March 27, 2014; contestants were required to submit 9 biweekly forecasts at the national level to be eligible. The selection of the winner was based on expert evaluation of the methodology used to make the prediction and the accuracy of the prediction as judged against the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet). Results: Nine teams submitted 13 forecasts for all required milestones. The first forecast was due on December 2, 2013; 3/13 forecasts received correctly predicted the start of the influenza season within one week, 1/13 predicted the peak within 1 week, 3/13 predicted the peak ILINet percentage within 1 %, and 4/13 predicted the season duration within 1 week. For the prediction due on December 19, 2013, the number of forecasts that correctly forecasted the peak week increased to 2/13, the peak percentage to 6/13, and the duration of the season to 6/13. As the season progressed, the forecasts became more stable and were closer to the season milestones. Conclusion: Forecasting has become technically feasible, but further efforts are needed to improve forecast accuracy so that policy makers can reliably use these predictions. CDC and challenge contestants plan to build upon the methods developed during this contest to improve the accuracy of influenza forecasts. © 2016 The Author(s)
The PCL–R and capital sentencing: A commentary on “Death is different” DeMatteo et al. (2020a).
DeMatteo et al. (2020a) published a Statement in this journal declaring that the Psychopathy Checklist-Revised (PCL-R) “cannot and should not” be used in U.S. capital-sentencing cases to assess risk for serious institutional violence. Their stated concerns were the PCL-R’s “imperfect interrater reliability,” its “variability in predictive validity,” and its prejudicial effects on the defendant. In a Cautionary Note, we (Olver et al., 2020) raised questions about the Statement’s evaluation of the PCL-R’s psychometric properties, presented new data, including a meta-meta-analysis, and argued that the evidence did not support the Statement’s declaration that the PCL-R “cannot” be used in high stakes contexts. In their reply, titled “Death is Different,” DeMatteo et al. (2020b) concurred with several points in our Cautionary Note, disputed others, asserted that we had misunderstood or mischaracterized their Statement, and dismissed our new data and comments as irrelevant to the Statement’s purpose. This perspective on our commentary is inimical to balanced academic discourse. In this article, we contend that DeMatteo et al. (2020b) underestimated the reliability and predictive validity of PCL-R ratings, overestimated the centrality of the PCL-R in sentencing decisions, and underplayed the importance of other factors. Most of their arguments depended on sources other than capital cases, including mock trials, Sexually Violent Predator (SVP) hearings, and studies that included the prediction of general violence. We conclude that the rationale for the bold “cannot and should not” decree is open to debate and in need of research in real-life venues
Reliability and validity of the Psychopathy Checklist-Revised in the assessment of risk for institutional violence: A cautionary note on DeMatteo et al. (2020).
A group of 12 authors (GA) shared a statement of concern (SoC) warning against the use of the Hare Psychopathy Checklist-Revised (PCL-R; Hare, 1991, 2003) to assess risk for serious institutional violence in US capital sentencing cases (DeMatteo et al., 2020). Notably, the SoC was not confined to capital sentencing issues, but included institutional violence in general. Central to the arguments presented in the SoC was that the PCL-R has poor predictive validity for institutional violence and also inadequate field reliability. The GA also identified important issues about the fallibility and inappropriate use of any clinical/forensic assessments, questionable evaluator qualifications, and their effects on capital sentencing decisions. However, as a group of forensic academics, researchers, and clinicians, we are concerned that the PCL-R represents a psycholegal red herring, while the SoC did not address critical legislative, systemic, and evaluator/rating issues that affect all risk assessment tools. We contend that the SoC’s literature review was selective and that the resultant opinions about potential uses and misuses of the PCL-R were ultimately misleading. We focus our response on the evidence and conclusions proffered by the GA concerning the use of the PCL-R in capital and other cases. We provide new empirical findings regarding the PCL-R’s predictive validity and field reliability to further demonstrate its relevance for institutional violence risk assessment and management. We further demonstrate why the argument that group data cannot be relevant for single-case assessments is erroneous. Recommendations to support the ethical and appropriate use of the PCL-R for risk assessment are provided
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Sexual health of ethnic minority MSM in Britain (MESH project): design and methods
Background: Men who have sex with men (MSM) remain the group most at risk of acquiring HIV infection in Britain. HIV prevalence appears to vary widely between MSM from different ethnic minority groups in this country for reasons that are not fully understood. The aim of the MESH project was to examine in detail the sexual health of ethnic minority MSM living in Britain.
Methods/Design: The main objectives of the MESH project were to explore among ethnic minority MSM living in Britain: (i) sexual risk behaviour and HIV prevalence; (ii) their experience of stigma and discrimination; (iii) disclosure of sexuality; (iv) use of, and satisfaction with sexual health services; (v) the extent to which sexual health services (for treatment and prevention) are aware of the needs of ethnic minority MSM.
The research was conducted between 2006 and 2008 in four national samples: (i) ethnic minority MSM living in Britain; (ii) a comparison group of white British MSM living in Britain; (iii) NHS sexual health clinic staff in 15 British towns and cities with significant ethnic minority communities and; (iv) sexual health promotion/HIV prevention service providers. We also recruited men from two “key migrant” groups living in Britain: MSM born in Central or Eastern Europe and MSM born in Central or South America.
Internet-based quantitative and qualitative research methods were used. Ethnic minority MSM were recruited through advertisements on websites, in community venues, via informal networks and in sexual health clinics. White and “key migrant” MSM were recruited mostly through Gaydar, one of the most popular dating sites used by gay men in Britain. MSM who agreed to take part completed a questionnaire online. Ethnic minority MSM who completed the online questionnaire were asked if they would be willing to take part in an online qualitative interview using email.
Service providers were identified through the British Association of Sexual Health and HIV (BASHH) and the Terrence Higgins Trust (THT) CHAPS partnerships. Staff who agreed to take part were asked to complete a questionnaire online.
The online survey was completed by 1241 ethnic minority MSM, 416 men born in South and Central America or Central and Eastern Europe, and 13,717 white British MSM; 67 ethnic minority MSM took part in the online qualitative interview. In addition 364 people working in sexual health clinics and 124 health promotion workers from around Britain completed an online questionnaire.
Discussion: The findings from this study will improve our understanding of the sexual health and needs of ethnic minority MSM in Britain
Searching for a Stochastic Background of Gravitational Waves with LIGO
The Laser Interferometer Gravitational-wave Observatory (LIGO) has performed
the fourth science run, S4, with significantly improved interferometer
sensitivities with respect to previous runs. Using data acquired during this
science run, we place a limit on the amplitude of a stochastic background of
gravitational waves. For a frequency independent spectrum, the new limit is
. This is currently the most sensitive
result in the frequency range 51-150 Hz, with a factor of 13 improvement over
the previous LIGO result. We discuss complementarity of the new result with
other constraints on a stochastic background of gravitational waves, and we
investigate implications of the new result for different models of this
background.Comment: 37 pages, 16 figure
Reliability and validity of two fitness tracker devices in the laboratory and home environment for older community-dwelling people
© 2018 The Author(s). Background: Two-thirds of older Australians are sedentary. Fitness trackers have been popular with younger people and may encourage older adults to become more active. Older adults may have different gait patterns and as such it is important to establish whether fitness trackers are valid and reliable for this population. The aim of the study was to test the reliability and validity of two fitness trackers (Fitbit Flex and ChargeHR) by step count when worn by older adults. Reliability and validity were tested in two conditions: 1) in the laboratory using a two-minute-walk-test (2MWT) and 2) in a free-living environment. Methods: Two 2MWTs were completed while wearing the fitness trackers. Participants were videoed during each test. Participants were then given one fitness tracker and a GENEactiv accelerometer to wear at home for 14-days. Results: Thirty-one participants completed two 2MWTs and 30 completed the free-living procedure. Intra Class Correlation's of the fitness trackers with direct observation of steps (criterion validity) was high (ICC:0.86,95%CI:0.76,0.93). However, both fitness trackers underestimated steps. Excellent test-retest reliability (ICC = 0.75) was found between the two 2MWTs for each device, particularly the ChargeHR devices. Good strength of agreement was found for total distance and steps (fitness tracker) and moderate-to-vigorous physical activity (GENEactiv) for the free-living environment (Spearman Rho's 0.78 and 0.74 respectively). Conclusion: Reliability and validity of the Flex and ChargeHR when worn by older adults is good, however both devices underestimated step count within the laboratory environment. These fitness trackers appear suitable for consumer use and promoting physical activity for older adults
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