169 research outputs found
What explains ethnic organizational violence? Evidence from Eastern Europe and Russia
Why do some ethnopolitical organizations use violence? Research on substate violence often uses the state level of analysis, or only analyzes groups that are already violent. Using a resource mobilization framework drawn from a broad literature, we test hypotheses with new data on hundreds of violent and non-violent ethnopolitical organizations in Eastern Europe and Russia. Our study finds interorganizational competition, state repression and strong group leadership associated with organizational violence. Lack of popularity and holding territory are also associated with violence. We do not find social service provision positively related to violence, which contrasts with research on the Middle East
Phagocytosis of Streptococcus pyogenes by all-trans retinoic acid-differentiated HL-60 cells: roles of azurophilic granules and NADPH oxidase.
BACKGROUND: New experimental approaches to the study of the neutrophil phagosome and bacterial killing prompted a reassessment of the usefulness of all-trans retinoic acid (ATRA)-differentiated HL-60 cells as a neutrophil model. HL-60 cells are special in that they possess azurophilic granules while lacking the specific granules with their associated oxidase components. The resulting inability to mount an effective intracellular respiratory burst makes these cells more dependent on other mechanisms when killing internalized bacteria. METHODOLOGY/PRINCIPAL FINDINGS: In this work phagocytosis and phagosome-related responses of ATRA-differentiated HL-60 cells were compared to those earlier described in human neutrophils. We show that intracellular survival of wild-type S. pyogenes bacteria in HL-60 cells is accompanied by inhibition of azurophilic granule-phagosome fusion. A mutant S. pyogenes bacterium, deficient in M-protein expression, is, on the other hand, rapidly killed in phagosomes that avidly fuse with azurophilic granules. CONCLUSIONS/SIGNIFICANCE: The current data extend our previous findings by showing that a system lacking in oxidase involvement also indicates a link between inhibition of azurophilic granule fusion and the intraphagosomal fate of S. pyogenes bacteria. We propose that differentiated HL-60 cells can be a useful tool to study certain aspects of neutrophil phagosome maturation, such as azurophilic granule fusion
Production of phi mesons at mid-rapidity in sqrt(s_NN) = 200 GeV Au+Au collisions at RHIC
We present the first results of meson production in the K^+K^- decay channel
from Au+Au collisions at sqrt(s_NN) = 200 GeV as measured at mid-rapidity by
the PHENIX detector at RHIC. Precision resonance centroid and width values are
extracted as a function of collision centrality. No significant variation from
the PDG accepted values is observed. The transverse mass spectra are fitted
with a linear exponential function for which the derived inverse slope
parameter is seen to be constant as a function of centrality. These data are
also fitted by a hydrodynamic model with the result that the freeze-out
temperature and the expansion velocity values are consistent with the values
previously derived from fitting single hadron inclusive data. As a function of
transverse momentum the collisions scaled peripheral.to.central yield ratio RCP
for the is comparable to that of pions rather than that of protons. This result
lends support to theoretical models which distinguish between baryons and
mesons instead of particle mass for explaining the anomalous proton yield.Comment: 326 authors, 24 pages text, 23 figures, 6 tables, RevTeX 4. To be
submitted to Physical Review C as a regular article. Plain text data tables
for the points plotted in figures for this and previous PHENIX publications
are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm
Targeting Tumour-Initiating Cells with TRAIL Based Combination Therapy Ensures Complete and Lasting Eradication of Multiple Myeloma Tumours In Vivo
Multiple myeloma (MM) remains an incurable disease despite improvements to available treatments and efforts to identify new drug targets. Consequently new approaches are urgently required. We have investigated the potential of native tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), in combination with doxorubicin, to induce apoptotic cell death in phenotypically distinct populations of myeloma cells in vitro and in vivo. The cytotoxic potential of TRAIL alone, and in combination with DOX, was assessed in vitro in purified CD138+ and CD138− cells from the MM cell lines and samples from patients with MM. Mouse xenografts obtained by implanting CD138− MM cells were used to assess the efficacy of TRAIL, alone and in combination with DOX, in vivo. CD138− cells were shown to be more resistant to the cytotoxic activity of TRAIL than CD138+ cells and have reduced expression of TRAIL death receptors. This resistance results in preferential killing of CD 138+ cells during exposure of MM culture to TRAIL. Furthermore, prolonged exposure results in the appearance of TRAIL-resistant CD138− cells. However, when TRAIL is combined with doxorubicin, this results in complete eradication of MM cells in vivo. Most importantly, this treatment successfully eliminates CD138− cells implicated in tumour initiation and growth maintenance. These findings may explain the failure of current therapies and offer a promising new approach in the quest to cure MM and disseminated cancers
Recommended from our members
Detection of early age-related macular degeneration using novel functional parameters of the focal cone electroretinogram
The focal cone electroretinogram is a sensitive marker for macular disease, but have we unlocked its full potential? Typically assessment of waveform parameters is subjective and focuses on a small number of locations (e.g. the a-wave). This study evaluated the discriminatory and diagnostic potential of 4 conventional and 15 novel, objectively determined, parameters in patients with early Age-related Macular Degeneration. Focal cone electroretinograms were recorded in 54 participants with early Age-related Macular Degeneration (72.9±8.2 years) and 54 healthy controls (69±7.7 years). Conventional a and b wave amplitudes and implicit times were measured and compared to novel parameters derived from both the 1st and 2nd derivatives and the frequency-domain power spectrum of the electroretinogram.Statistically significant differences between groups were shown for all conventional parameters, the majority of 1st and 2nd derivative parameters and the power spectrum at 25 and 30 Hz. Receiver operating characteristics showed that both conventional and 1st and 2nd derivative implicit times had provided the best diagnostic potential. A regression model showed a small improvement over any individual parameter investigated. The non-conventional parameters enhanced the objective evaluation of the focal electroretinogram, especially when the amplitude was low. Furthermore, the novel parameters described here allow the implicit time of the electroretinogram to be probed at points other than the peaks of the a and b waves. Consequently these novel analysis techniques could prove valuable in future electrophysiological investigation, detection and monitoring of Age-related Macular Degeneration
Active multiple myeloma suppresses and typically eliminates coexisting MGUS
Background: Myeloma is consistently preceded by premalignant monoclonal gammopathy of undetermined significance (MGUS). In >5% of MGUS patients there is a second MGUS clone (biclonal gammopathy of undetermined significance; BGUS), yet, at myeloma diagnosis, presentation of biclonal gammopathy myeloma (BGMy) is considered less frequent, implying that myeloma eradicates coexisting MGUS.
Methods: In the largest study of its kind, we assessed BGMy frequency amongst 6399 newly diagnosed myeloma patients enrolled in recent UK clinical trials.
Results: Compared to expected prevalence (i.e., >5% of MGUS have BGUS), only 58 of 6399 (0.91%) newly diagnosed myeloma patients had BGMy, indicating myeloma typically eliminates coexistent MGUS. In these 58 BGMy cases, the MGUS plasma cell clone was greatly suppressed in size compared to typical levels observed in conventional MGUS; contrarily, the MGUS clone did not inhibit the myeloma plasma cell clone in BGMy.
Conclusion: Myeloma eliminates the majority of competing MGUS, and when it does not, the MGUS clone is substantially reduced in size
Recommended practices for computerized clinical decision support and knowledge management in community settings: a qualitative study
<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to identify recommended practices for computerized clinical decision support (CDS) development and implementation and for knowledge management (KM) processes in ambulatory clinics and community hospitals using commercial or locally developed systems in the U.S.</p> <p>Methods</p> <p>Guided by the Multiple Perspectives Framework, the authors conducted ethnographic field studies at two community hospitals and five ambulatory clinic organizations across the U.S. Using a Rapid Assessment Process, a multidisciplinary research team: gathered preliminary assessment data; conducted on-site interviews, observations, and field surveys; analyzed data using both template and grounded methods; and developed universal themes. A panel of experts produced recommended practices.</p> <p>Results</p> <p>The team identified ten themes related to CDS and KM. These include: 1) workflow; 2) knowledge management; 3) data as a foundation for CDS; 4) user computer interaction; 5) measurement and metrics; 6) governance; 7) translation for collaboration; 8) the meaning of CDS; 9) roles of special, essential people; and 10) communication, training, and support. Experts developed recommendations about each theme. The original Multiple Perspectives framework was modified to make explicit a new theoretical construct, that of Translational Interaction.</p> <p>Conclusions</p> <p>These ten themes represent areas that need attention if a clinic or community hospital plans to implement and successfully utilize CDS. In addition, they have implications for workforce education, research, and national-level policy development. The Translational Interaction construct could guide future applied informatics research endeavors.</p
The UK clinical eye research strategy: refreshing research priorities for clinical eye research in the UK
OBJECTIVES: To validate and update the 2013 James Lind Alliance (JLA) Sight Loss and Vision Priority Setting Partnership (PSP)'s research priorities for Ophthalmology, as part of the UK Clinical Eye Research Strategy. METHODS: Twelve ophthalmology research themes were identified from the JLA report. They were allocated to five Clinical Study Groups of diverse stakeholders who reviewed the top 10 research priorities for each theme. Using an online survey (April 2021-February 2023), respondents were invited to complete one or more of nine subspecialty surveys. Respondents indicated which of the research questions they considered important and subsequently ranked them. RESULTS: In total, 2240 people responded to the survey (mean age, 59.3 years), from across the UK. 68.1% were female. 68.2% were patients, 22.3% healthcare professionals or vision researchers, 7.1% carers, and 2.1% were charity support workers. Highest ranked questions by subspecialty: Cataract (prevention), Cornea (improving microbial keratitis treatment), Optometric (impact of integration of ophthalmic primary and secondary care via community optometric care pathways), Refractive (factors influencing development and/or progression of refractive error), Childhood onset (improving early detection of visual disorders), Glaucoma (effective and improved treatments), Neuro-ophthalmology (improvements in prevention, diagnosis and treatment of neurodegeneration affecting vision), Retina (improving prevention, diagnosis and treatment of dry age-related macular degeneration), Uveitis (effective treatments for ocular and orbital inflammatory diseases). CONCLUSIONS: A decade after the initial PSP, the results refocus the most important research questions for each subspecialty, and prime targeted research proposals within Ophthalmology, a chronically underfunded specialty given the substantial burden of disability caused by eye disease
Latanoprost treatment for open angle glaucoma. The United Kingdom Glaucoma Treatment Study: a multicentre, randomised, placebo-controlled clinical trial
BACKGROUND: Treatment of open-angle glaucoma (OAG) aims to prevent vision loss by lowering intraocular pressure (IOP), yet there has been no previous placebo-controlled medical treatment trial assessing vision function preservation. Observation periods in previous (unmasked) trials assessing visual function have typically been at least 5 years. The aim of this study was to assess vision preservation by latanoprost treatment compared to placebo. METHODS In this randomised, triple-masked, placebo-controlled trial, patients with newly-diagnosed OAG were enrolled at 10 UK centres (tertiary referral centres, teaching hospitals, and district general hospitals) between Feb 2007 and Mar 2010. Eligible patients were randomly allocated (1:1) to receive either latanoprost 0·005% or placebo eye drops, provided in identical bottles, once daily to both eyes. Randomization was in permuted blocks stratified by participating centre. The primary hypothesis was that latanoprost treatment reduces incident visual field (VF) deterioration, compared with placebo, by 50% over 2 years. The primary outcome was VF deterioration: 3 locations in the Pattern Deviation Glaucoma Change Probability maps worse than baseline in 2 consecutive VFs, present in 2 consecutive VF pairs. The primary analysis was VF survival in the intention-to-treat population. The trial was terminated in July 2011 on the recommendation of the independent data monitoring committee following an interim analysis. Trial registration number: ISRCTN96423140. FINDINGS: 516 patients were randomised and data on all subjects with post-allocation data (461) were analysed. 18 serious adverse events were reported, none attributable to the study drug. Baseline mean (SD) IOP was 19·6 (4·6) mmHg and 20·1 (4·8) mmHg, and IOP reduction at 24 months 3·8 (4·0) mmHg and 0·9 (3·8) mmHg, in the latanoprost and placebo groups, respectively. Incident VF deterioration (95% CI) by 24 months was 15·0% (10·8, 20·0) in the latanoprost group and 24·8% (19·5, 30·7) in the placebo group (P=0·007). VF survival was significantly longer in the latanoprost group: at 24 months, adjusted hazard ratio (HR) 0·44 (0·28, 0·69) (P=0·0003). The difference between treatment groups was evident after only 12 months, HR 0·47 (0·23, 0·95) (P=0·035). INTERPRETATION: This is the first placebo-controlled trial to demonstrate VF preservation with an IOP-lowering agent in OAG. The study design enabled a relatively short observation period. FUNDING: Pfizer Inc.; UK National Institute for Health Research Biomedical Research Centre
- …