126 research outputs found

    Cell sorting in a Petri dish controlled by computer vision.

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    Fluorescence-activated cell sorting (FACS) applying flow cytometry to separate cells on a molecular basis is a widespread method. We demonstrate that both fluorescent and unlabeled live cells in a Petri dish observed with a microscope can be automatically recognized by computer vision and picked up by a computer-controlled micropipette. This method can be routinely applied as a FACS down to the single cell level with a very high selectivity. Sorting resolution, i.e., the minimum distance between two cells from which one could be selectively removed was 50-70 micrometers. Survival rate with a low number of 3T3 mouse fibroblasts and NE-4C neuroectodermal mouse stem cells was 66 +/- 12% and 88 +/- 16%, respectively. Purity of sorted cultures and rate of survival using NE-4C/NE-GFP-4C co-cultures were 95 +/- 2% and 62 +/- 7%, respectively. Hydrodynamic simulations confirmed the experimental sorting efficiency and a cell damage risk similar to that of normal FACS

    9-Genes Reinforce the Phylogeny of Holometabola and Yield Alternate Views on the Phylogenetic Placement of Strepsiptera

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    Background: The extraordinary morphology, reproductive and developmental biology, and behavioral ecology of twisted wing parasites (order Strepsiptera) have puzzled biologists for centuries. Even today, the phylogenetic position of these enigmatic “insects from outer space” [1] remains uncertain and contentious. Recent authors have argued for the placement of Strepsiptera within or as a close relative of beetles (order Coleoptera), as sister group of flies (order Diptera), or even outside of Holometabola.Methodology/Principal Findings Here, we combine data from several recent studies with new data (for a total of 9 nuclear genes and ∼13 kb of aligned data for 34 taxa), to help clarify the phylogenetic placement of Strepsiptera. Our results unequivocally support the monophyly of Neuropteroidea ( = Neuropterida + Coleoptera) + Strepsiptera, but recover Strepsiptera either derived from within polyphagan beetles (order Coleoptera), or in a position sister to Neuropterida. All other supra-ordinal- and ordinal-level relationships recovered with strong nodal support were consistent with most other recent studies. Conclusions/Significance: These results, coupled with the recent proposed placement of Strepsiptera sister to Coleoptera, suggest that while the phylogenetic neighborhood of Strepsiptera has been identified, unequivocal placement to a specific branch within Neuropteroidea will require additional study.Organismic and Evolutionary Biolog

    Proton acceleration enhanced by a plasma jet in expanding foils undergoing relativistic transparency

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    Ion acceleration driven by the interaction of an ultraintense (2x10^20 Wcm^-2) laser pulse with an ultrathin (40nm) foil target is experimentally and numerically investigated. Protons accelerated by sheath fields and via laser radiation pressure are angularly separated and identified based on their directionality and signature features (e.g. transverse instabilities) in the measured spatial-intensity distribution. A low divergence, high energy proton component is also detected when the heated target electrons expand and the target becomes relativistically transparent during the interaction. 2D and 3D particle-in-cell (PIC) simulations indicate that under these conditions a plasma jet is formed at the target rear, supported by a self-generated azimuthal magnetic field, which extends into the expanded layer of sheath-accelerated protons. Electrons trapped within this jet are directly accelerated to super-thermal energies by the portion of the laser pulse transmitted through the target. The resulting streaming of the electrons into the ion layers enhances the energy of protons in the vicinity of the jet. Through the addition of a controlled prepulse, the maximum energy of these protons is demonstrated experimentally and numerically to be sensitive to the picosecond rising edge prole of the laser pulse

    The commensal infant gut meta-mobilome as a potential reservoir for persistent multidrug resistance integrons

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    Despite the accumulating knowledge on the development and establishment of the gut microbiota, its role as a reservoir for multidrug resistance is not well understood. This study investigated the prevalence and persistence patterns of an integrase gene (int1), used as a proxy for integrons (which often carry multiple antimicrobial resistance genes), in the fecal microbiota of 147 mothers and their children sampled longitudinally from birth to 2 years. The study showed the int1 gene was detected in 15% of the study population, and apparently more persistent than the microbial community structure itself. We found int1 to be persistent throughout the first two years of life, as well as between mothers and their 2-year-old children. Metagenome sequencing revealed integrons in the gut meta-mobilome that were associated with plasmids and multidrug resistance. In conclusion, the persistent nature of integrons in the infant gut microbiota makes it a potential reservoir of mobile multidrug resistance

    Differentiation of mouse bone marrow derived stem cells toward microglia-like cells

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    <p>Abstract</p> <p>Background</p> <p>Microglia, the macrophages of the brain, have been implicated in the causes of neurodegenerative diseases and display a loss of function during aging. Throughout life, microglia are replenished by limited proliferation of resident microglial cells. Replenishment by bone marrow-derived progenitor cells is still under debate. In this context, we investigated the differentiation of mouse microglia from bone marrow (BM) stem cells. Furthermore, we looked at the effects of FMS-like tyrosine kinase 3 ligand (Flt3L), astrocyte-conditioned medium (ACM) and GM-CSF on the differentiation to microglia-like cells.</p> <p>Methods</p> <p>We assessed <it>in vitro-</it>derived microglia differentiation by marker expression (CD11b/CD45, F4/80), but also for the first time for functional performance (phagocytosis, oxidative burst) and <it>in situ </it>migration into living brain tissue. Integration, survival and migration were assessed in organotypic brain slices.</p> <p>Results</p> <p>The cells differentiated from mouse BM show function, markers and morphology of primary microglia and migrate into living brain tissue. Flt3L displays a negative effect on differentiation while GM-CSF enhances differentiation.</p> <p>Conclusion</p> <p>We conclude that <it>in vitro-</it>derived microglia are the phenotypic and functional equivalents to primary microglia and could be used in cell therapy.</p

    Gene polymorphisms against DNA damage induced by hydrogen peroxide in leukocytes of healthy humans through comet assay: a quasi-experimental study

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    <p>Abstract</p> <p>Background</p> <p>Normal cellular metabolism is well established as the source of endogenous reactive oxygen species which account for the background levels of oxidative DNA damage detected in normal tissue. Hydrogen peroxide imposes an oxidative stress condition on cells that can result in DNA damage, leading to mutagenesis and cell death. Several potentially significant genetic variants related to oxidative stress have already been identified, and angiotensin I-converting enzyme (ACE) inhibitors have been reported as possible antioxidant agents that can reduce vascular oxidative stress in cardiovascular events.</p> <p>Methods</p> <p>We investigate the influences of haptoglobin, manganese superoxide dismutase (MnSOD Val9Ala), catalase (CAT -21A/T), glutathione peroxidase 1 (GPx-1 Pro198Leu), ACE (I/D) and gluthatione S-transferases GSTM1 and GSTT1 gene polymorphisms against DNA damage and oxidative stress. These were induced by exposing leukocytes from peripheral blood of healthy humans (N = 135) to hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>), and the effects were tested by comet assay. Blood samples were submitted to genotyping and comet assay (before and after treatment with H<sub>2</sub>O<sub>2 </sub>at 250 μM and 1 mM).</p> <p>Results</p> <p>After treatment with H<sub>2</sub>O<sub>2 </sub>at 250 μM, the GPx-1 polymorphism significantly influenced results of comet assay and a possible association of the Pro/Leu genotype with higher DNA damage was found. The highest or lowest DNA damage also depended on interaction between GPX-1/ACE and Hp/GSTM1T1 polymorphisms when hydrogen peroxide treatment increased oxidative stress.</p> <p>Conclusions</p> <p>The GPx-1 polymorphism and the interactions between GPX-1/ACE and Hp/GSTM1T1 can be determining factors for DNA oxidation provoked by hydrogen peroxide, and thus for higher susceptibility to or protection against oxidative stress suffered by healthy individuals.</p

    Pragmatic randomised controlled trial of guided self-help versus individual cognitive behavioural therapy with a trauma focus for post-traumatic stress disorder (RAPID)

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    This is the final version. Available on open access from the NIHR Journals Library via the DOI in this recordData availability: All available data can be obtained from the corresponding author.BACKGROUND: Guided self-help has been shown to be effective for other mental conditions and, if effective for post-traumatic stress disorder, would offer a time-efficient and accessible treatment option, with the potential to reduce waiting times and costs. OBJECTIVE: To determine if trauma-focused guided self-help is non-inferior to individual, face-to-face cognitive-behavioural therapy with a trauma focus for mild to moderate post-traumatic stress disorder to a single traumatic event. DESIGN: Multicentre pragmatic randomised controlled non-inferiority trial with economic evaluation to determine cost-effectiveness and nested process evaluation to assess fidelity and adherence, dose and factors that influence outcome (including context, acceptability, facilitators and barriers, measured qualitatively). Participants were randomised in a 1 : 1 ratio. The primary analysis was intention to treat using multilevel analysis of covariance. SETTING: Primary and secondary mental health settings across the United Kingdom's National Health Service. PARTICIPANTS: One hundred and ninety-six adults with a primary diagnosis of mild to moderate post-traumatic stress disorder were randomised with 82% retention at 16 weeks and 71% at 52 weeks. Nineteen participants and ten therapists were interviewed for the process evaluation. INTERVENTIONS: Up to 12 face-to-face, manualised, individual cognitive-behavioural therapy with a trauma focus sessions, each lasting 60-90 minutes, or to guided self-help using Spring, an eight-step online guided self-help programme based on cognitive-behavioural therapy with a trauma focus, with up to five face-to-face meetings of up to 3 hours in total and four brief telephone calls or e-mail contacts between sessions. MAIN OUTCOME MEASURES: Primary outcome: the Clinician-Administered PTSD Scale for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, at 16 weeks post-randomisation. Secondary outcomes: included severity of post-traumatic stress disorder symptoms at 52 weeks, and functioning, symptoms of depression, symptoms of anxiety, alcohol use and perceived social support at both 16 and 52 weeks post-randomisation. Those assessing outcomes were blinded to group assignment. RESULTS: Non-inferiority was demonstrated at the primary end point of 16 weeks on the Clinician-Administered PTSD Scale for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition [mean difference 1.01 (one-sided 95% CI -∞ to 3.90, non-inferiority p = 0.012)]. Clinician-Administered PTSD Scale for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, score improvements of over 60% in both groups were maintained at 52 weeks but the non-inferiority results were inconclusive in favour of cognitive-behavioural therapy with a trauma focus at this timepoint [mean difference 3.20 (one-sided 95% confidence interval -∞ to 6.00, non-inferiority p = 0.15)]. Guided self-help using Spring was not shown to be more cost-effective than face-to-face cognitive-behavioural therapy with a trauma focus although there was no significant difference in accruing quality-adjusted life-years, incremental quality-adjusted life-years -0.04 (95% confidence interval -0.10 to 0.01) and guided self-help using Spring was significantly cheaper to deliver [£277 (95% confidence interval £253 to £301) vs. £729 (95% CI £671 to £788)]. Guided self-help using Spring appeared to be acceptable and well tolerated by participants. No important adverse events or side effects were identified. LIMITATIONS: The results are not generalisable to people with post-traumatic stress disorder to more than one traumatic event. CONCLUSIONS: Guided self-help using Spring for mild to moderate post-traumatic stress disorder to a single traumatic event appears to be non-inferior to individual face-to-face cognitive-behavioural therapy with a trauma focus and the results suggest it should be considered a first-line treatment for people with this condition. FUTURE WORK: Work is now needed to determine how best to effectively disseminate and implement guided self-help using Spring at scale. TRIAL REGISTRATION: This trial is registered as ISRCTN13697710. FUNDING: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 14/192/97) and is published in full in Health Technology Assessment; Vol. 27, No. 26. See the NIHR Funding and Awards website for further award information.National Institute for Health and Care Research (NIHR
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