84 research outputs found
Hypothermia protects human neurons
Background and Aims: Hypothermia provides neuroprotection after cardiac arrest, hypoxic-ischemic encephalopathy, and in animal models of ischemic stroke. However, as drug development for stroke has been beset by translational failure, we sought additional evidence that hypothermia protects human neurons against ischemic injury.
Methods: Human embryonic stem cells were cultured and differentiated to provide a source of neurons expressing β III tubulin, microtubule-associated protein 2, and the Neuronal Nuclei antigen. Oxygen deprivation, oxygen-glucose deprivation, and H2O2 -induced oxidative stress were used to induce relevant injury.
Results: Hypothermia to 33°C protected these human neurons against H2O2 -induced oxidative stress reducing lactate dehydrogenase release and Terminal deoxynucleotidyl transferase dUTP nick end labeling-staining by 53% (P≤0·0001; 95% confidence interval 34·8-71·04) and 42% (P≤0·0001; 95% confidence interval 27·5-56·6), respectively, after 24 h in culture. Hypothermia provided similar protection against oxygen-glucose deprivation (42%, P≤0·001, 95% confidence interval 18·3-71·3 and 26%, P≤0·001; 95% confidence interval 12·4-52·2, respectively) but provided no protection against oxygen deprivation alone. Protection (21%) persisted against H2O2 -induced oxidative stress even when hypothermia was initiated six-hours after onset of injury (P≤0·05; 95% confidence interval 0·57-43·1).
Conclusion: We conclude that hypothermia protects stem cell-derived human neurons against insults relevant to stroke over a clinically relevant time frame. Protection against H2O2 -induced injury and combined oxygen and glucose deprivation but not against oxygen deprivation alone suggests an interaction in which protection benefits from reduction in available glucose under some but not all circumstances
Sensitivity of Colorectal Cancer to Arginine Deprivation Therapy is Shaped by Differential Expression of Urea Cycle Enzymes
We thank Polaris Pharmaceuticals and Bio-Cancer Treatment for providing drugs and reagents. This work was supported by the Cancer Prevention Research Trust, with assistance from the Wellcome Trust Institutional Strategic Support Fund [097828/z/11/B], and Cancer Research UK in conjunction with the Department of Health as part of an Experimental Cancer Medicine Centre grant [C325/A15575]. C.A. was funded by a PhD fellowship from the Cancer Prevention Research Trust, S.S.A. was funded by a studentship from the Iraqi Government. We are thankful to John Bomalaski and Sara Galavotti for their critical reading of the manuscript and insightful suggestions. Finally, we are profoundly indebted to Professor Andreas Gescher for his constant support during the execution of this project and the writing of this manuscript.Peer reviewedPublisher PD
Vitamin D to prevent lung injury following esophagectomy: A randomized, placebo-controlled trial
Objectives: Observational studies suggest an association between vitamin D deficiency and adverse outcomes of critical illness and identify it as a potential risk factor for the development of lung injury. To determine whether pre-operative administration of oral high-dose cholecalciferol ameliorates early acute lung injury post-operatively in adults undergoing elective esophagectomy. Design: A double-blind, randomized, placebo-controlled trial. Setting: Three large UK university hospitals. Patients: Seventy-nine adult patients undergoing elective esophagectomy were randomized. Intervention: A single oral preoperative (3-14 days) dose of 7.5mg (300,000IU; 15mls) cholecalciferol or matched placebo. Measurements and Main Results: Primary outcome was change in extravascular lung water index (EVLWI) at the end of esophagectomy. Secondary outcomes included PaO2:FiO2 ratio, development of lung injury, ventilator and organ-failure free days, 28 and 90 day survival, safety of cholecalciferol supplementation, plasma vitamin D status (25(OH)D, 1,25(OH)2D and vitamin D binding protein), pulmonary vascular permeability index (PVPI) and EVLWI day 1 postoperatively. An exploratory study measured biomarkers of alveolar-capillary inflammation and injury. Forty patients were randomized to cholecalciferol and 39 to placebo. There was no significant change in EVLWI at the end of the operation between treatment groups (placebo median 1.0[IQR 0.4 – 1.8] vs cholecalciferol median 0.4[IQR 0.4 – 1.2] ml/kg, p=0.059). Median PVPI values were significantly lower in the cholecalciferol treatment group (placebo 0.4[IQR 0 – 0.7] vs cholecalciferol 0.1[IQR -0.15 -0.35], p=0.027). Cholecalciferol treatment effectively increased 25(OH)D concentrations but surgery resulted in a decrease in 25(OH)D concentrations at day 3 in both arms. There was no difference in clinical outcomes. Conclusions: High-dose preoperative treatment with oral cholecalciferol was effective at increasing 25(OH)D concentrations, and reduced changes in postoperative PVPI but not EVLWI
Herding Cats: Modelling, Simulation, Testing, and Data Mining for Weak Memory
We propose an axiomatic generic framework for modelling weak memory. We show how to instantiate this framework for SC, TSO, C++ restricted to release-acquire atomics, and Power. For Power, we compare our model to a preceding operational model in which we found a flaw. To do so, we define an operational model that we show equivalent to our axiomatic model. We also propose a model for ARM. Our testing on this architecture revealed a behaviour later acknowl-edged as a bug by ARM, and more recently 31 additional anomalies. We offer a new simulation tool, called herd, which allows the user to specify the model of his choice in a concise way. Given a specification of a model, the tool becomes a simulator for that model. The tool relies on an axiomatic description; this choice allows us to outperform all previous simulation tools. Additionally, we confirm that verification time is vastly improved, in the case of bounded model checking. Finally, we put our models in perspective, in the light of empirical data obtained by analysing the C and C++ code of a Debian Linux distribution. We present our new analysis tool, called mole, which explores a piece of code to find the weak memory idioms that it uses
The Bristol Method: Green Capital Student Capital - The power of student sustainability engagement
THE BRISTOL METHODThe Bristol Method is a knowledge-transfer programme aimed at helping people in other cities understand and apply the lessons that Bristol has learned in becoming a more sustainable city, not just in 2015 but in the last decade. Each module of the Bristol Method is presented as an easy-to-digest ‘how to’ guide on a particular topic, which use Bristol’s experiences as a case study. The modules contain generic advice and recommendations that each reader can tailor to their own circumstances.This module focusses on the Green Capital: Student Capital project, and explains how the University of the West of England, Bristol (UWE) and the University of Bristol – with their respective students’ unions – have been working in partnership with the city and local communities, using Higher Education Funding Council for England Catalyst funding to promote student involvement in Green Capital activities across Greater Bristol.Student Capital created a broad programme of citywide impact during European Green Capital. It delivered a programme of student and staff engagement in enhancing sustainability within the city and has developed student and staff engagement with sustainability action. Through action research approaches it is also providing lessons for how institutions can collaborate across cities and communities to have internal and external impacts for sustainability. This report is for anyone seeking to increase sustainability engagement. In it we tell the story of the Student Capital project, explaining the processes and the outcomes, and suggesting pieces of advice and lessons for what went well, and what could have been done better or differently
Reporting animal research:Explanation and elaboration for the ARRIVE guidelines 2.0
Improving the reproducibility of biomedical research is a major challenge. Transparent and accurate reporting is vital to this process; it allows readers to assess the reliability of the findings and repeat or build upon the work of other researchers. The ARRIVE guidelines (Animal Research: Reporting In Vivo Experiments) were developed in 2010 to help authors and journals identify the minimum information necessary to report in publications describing in vivo experiments. Despite widespread endorsement by the scientific community, the impact of ARRIVE on the transparency of reporting in animal research publications has been limited. We have revised the ARRIVE guidelines to update them and facilitate their use in practice. The revised guidelines are published alongside this paper. This explanation and elaboration document was developed as part of the revision. It provides further information about each of the 21 items in ARRIVE 2.0, including the rationale and supporting evidence for their inclusion in the guidelines, elaboration of details to report, and examples of good reporting from the published literature. This document also covers advice and best practice in the design and conduct of animal studies to support researchers in improving standards from the start of the experimental design process through to publication
Human Remains from the Pleistocene-Holocene Transition of Southwest China Suggest a Complex Evolutionary History for East Asians
BACKGROUND: Later Pleistocene human evolution in East Asia remains poorly understood owing to a scarcity of well described, reliably classified and accurately dated fossils. Southwest China has been identified from genetic research as a hotspot of human diversity, containing ancient mtDNA and Y-DNA lineages, and has yielded a number of human remains thought to derive from Pleistocene deposits. We have prepared, reconstructed, described and dated a new partial skull from a consolidated sediment block collected in 1979 from the site of Longlin Cave (Guangxi Province). We also undertook new excavations at Maludong (Yunnan Province) to clarify the stratigraphy and dating of a large sample of mostly undescribed human remains from the site. METHODOLOGY/PRINCIPAL FINDINGS: We undertook a detailed comparison of cranial, including a virtual endocast for the Maludong calotte, mandibular and dental remains from these two localities. Both samples probably derive from the same population, exhibiting an unusual mixture of modern human traits, characters probably plesiomorphic for later Homo, and some unusual features. We dated charcoal with AMS radiocarbon dating and speleothem with the Uranium-series technique and the results show both samples to be from the Pleistocene-Holocene transition: ∼14.3-11.5 ka. CONCLUSIONS/SIGNIFICANCE: Our analysis suggests two plausible explanations for the morphology sampled at Longlin Cave and Maludong. First, it may represent a late-surviving archaic population, perhaps paralleling the situation seen in North Africa as indicated by remains from Dar-es-Soltane and Temara, and maybe also in southern China at Zhirendong. Alternatively, East Asia may have been colonised during multiple waves during the Pleistocene, with the Longlin-Maludong morphology possibly reflecting deep population substructure in Africa prior to modern humans dispersing into Eurasia
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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