753 research outputs found

    Vaporized Nicotine Inhalation Increases Arterial Pressure in both Supine and 70o Head-up Positions

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    ABSTRACT Electronic cigarettes (e-cigs) are popular with smokers looking for a healthier alternative to tobacco cigarettes. E-cigs utilize a battery, activated on inhalation, to heat propylene glycol-suspended nicotine which is inhaled as vapor, and which does not include harmful poisons found in conventional cigarettes. Although the health claims of e-cigs continue to be debated, the effects of nicotine delivered as vapor on the cardiovascular system have not been studied. Because nicotine is a sympathomemetic agent, we tested the hypothesis that e-cigs would increase arterial pressure and protect against challenges associated with upright posture. Ten non-smoking subjects (5 male) participated in two experimental trials, separated by one week (randomized). Seated blood pressures were taken after a 10 min quiet rest period, and then subjects either inhaled (once every 30 s for 10 min) on an e-cig with a placebo cartridge (0 mg nicotine) or an active cartridge (18 mg nicotine). After an additional 10 min quiet seated rest, we measured blood pressure again, and then subjects provided a urine sample for analysis of cotinine (a nicotine biomarker). We recorded ECG and finger photoplethysmographic arterial pressure. Subjects breathed to a metronome set at 15 breaths/min for 5 min supine, 5 min head-up (70o), and 5 min supine (recovery). Cotinine readings failed to register the presence of nicotine in urine, but a majority of subjects experienced dizziness and nausea after the active, but not the placebo cartridge. Seated arterial pressures were similar after the placebo cartridge (p ≄ .05), but increased from 112 ± 3/62 ± 2 mmHg to 115 ± 3/67 ± 3 after the nicotine cartridge (p ≀. 05). Systolic and diastolic pressures were higher (all p ≀ .05) after the nicotine trial compared to placebo for supine (115 ± 3/69 ± 2 vs. 106 ± 4/62 ± 2 mmHg), tilt (105 ± 4/66 ± 3 vs. 93 ± 4/60 ± 3 mmHg), and recovery (117 ± 5/72 ± 2 vs. 106 ± 4/64 ± 3 mmHg). No subject experienced presyncope during tilt for either trial. We show, for the first time, that inhalation of vaporized nicotine increases arterial pressure in the seated, supine and head-up tilt positions - suggesting sympathomemetic properties. Although mild, acute increases in arterial pressure may seem harmless, it is possible that daily, continuous use of e-cigs could result in consistently elevated arterial pressure, resulting in higher afterload and chronic cardiac strain

    Red blood cell transfusion and outcomes in patients with acute lung injury, sepsis and shock

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    Introduction: In this study, we sought to determine the association between red blood cell (RBC) transfusion and outcomes in patients with acute lung injury (ALI), sepsis and shock.Methods: We performed a secondary analysis of new-onset ALI patients enrolled in the Acute Respiratory Distress Syndrome Network Fluid and Catheter Treatment Trial (2000 to 2005) who had a documented ALI risk factor of sepsis or pneumonia and met shock criteria (mean arterial pressure (MAP) < 60 mmHg or vasopressor use) within 24 hours of randomization. Using multivariable logistic regression, we examined the association between RBC transfusion and 28-day mortality after adjustment for age, sex, race, randomization arm and Acute Physiology and Chronic Health Evaluation III score. Secondary end points included 90-day mortality and ventilator-free days (VFDs). Finally, we examined these end points among the subset of subjects meeting prespecified transfusion criteria defined by five simultaneous indicators: hemoglobin < 10.2 g/dL, central or mixed venous oxygen saturation < 70%, central venous pressure ≄ 8 mmHg, MAP ≄ 65 mmHg, and vasopressor use.Results: We identified 285 subjects with ALI, sepsis, shock and transfusion data. Of these, 85 also met the above prespecified transfusion criteria. Fifty-three (19%) of the two hundred eighty-five subjects with shock and twenty (24%) of the subset meeting the transfusion criteria received RBC transfusion within twenty-four hours of randomization. We found no independent association between RBC transfusion and 28-day mortality (odds ratio = 1.49, 95% CI (95% confidence interval) = 0.77 to 2.90; P = 0.23) or VFDs (mean difference = -0.35, 95% CI = -4.03 to 3.32; P = 0.85). Likewise, 90-day mortality and VFDs did not differ by transfusion status. Among the subset of patients meeting the transfusion criteria, we found no independent association between transfusion and mortality or VFDs.Conclusions: In patients with new-onset ALI, sepsis and shock, we found no independent association between RBC transfusion and mortality or VFDs. The physiological criteria did not identify patients more likely to be transfused or to benefit from transfusion. © 2011 Parsons et al. licensee BioMed Central Ltd

    Parallelized computational 3D video microscopy of freely moving organisms at multiple gigapixels per second

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    To study the behavior of freely moving model organisms such as zebrafish (Danio rerio) and fruit flies (Drosophila) across multiple spatial scales, it would be ideal to use a light microscope that can resolve 3D information over a wide field of view (FOV) at high speed and high spatial resolution. However, it is challenging to design an optical instrument to achieve all of these properties simultaneously. Existing techniques for large-FOV microscopic imaging and for 3D image measurement typically require many sequential image snapshots, thus compromising speed and throughput. Here, we present 3D-RAPID, a computational microscope based on a synchronized array of 54 cameras that can capture high-speed 3D topographic videos over a 135-cm^2 area, achieving up to 230 frames per second at throughputs exceeding 5 gigapixels (GPs) per second. 3D-RAPID features a 3D reconstruction algorithm that, for each synchronized temporal snapshot, simultaneously fuses all 54 images seamlessly into a globally-consistent composite that includes a coregistered 3D height map. The self-supervised 3D reconstruction algorithm itself trains a spatiotemporally-compressed convolutional neural network (CNN) that maps raw photometric images to 3D topography, using stereo overlap redundancy and ray-propagation physics as the only supervision mechanism. As a result, our end-to-end 3D reconstruction algorithm is robust to generalization errors and scales to arbitrarily long videos from arbitrarily sized camera arrays. The scalable hardware and software design of 3D-RAPID addresses a longstanding problem in the field of behavioral imaging, enabling parallelized 3D observation of large collections of freely moving organisms at high spatiotemporal throughputs, which we demonstrate in ants (Pogonomyrmex barbatus), fruit flies, and zebrafish larvae

    Social Influence in Televised Election Debates: A Potential Distortion of Democracy

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    A recent innovation in televised election debates is a continuous response measure (commonly referred to as the “worm”) that allows viewers to track the response of a sample of undecided voters in real-time. A potential danger of presenting such data is that it may prevent people from making independent evaluations. We report an experiment with 150 participants in which we manipulated the worm and superimposed it on a live broadcast of a UK election debate. The majority of viewers were unaware that the worm had been manipulated, and yet we were able to influence their perception of who won the debate, their choice of preferred prime minister, and their voting intentions. We argue that there is an urgent need to reconsider the simultaneous broadcast of average response data with televised election debates

    Author Correction: Cross-ancestry genome-wide association analysis of corneal thickness strengthens link between complex and Mendelian eye diseases.

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    Emmanuelle Souzeau, who contributed to analysis of data, was inadvertently omitted from the author list in the originally published version of this Article. This has now been corrected in both the PDF and HTML versions of the Article

    Precision oncology in surgery: patient selection for operable pancreatic cancer

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    Objective: We aimed to define preoperative clinical and molecular characteristics that would allow better patient selection for operative resection. Background: Although we use molecular selection methods for systemic targeted therapies, these principles are not applied to surgical oncology. Improving patient selection is of vital importance for the operative treatment of pancreatic cancer (pancreatic ductal adenocarcinoma). Although surgery is the only chance of long-term survival, 80% still succumb to the disease and approximately 30% die within 1 year, often sooner than those that have unresected local disease. Method: In 3 independent pancreatic ductal adenocarcinoma cohorts (total participants = 1184) the relationship between aberrant expression of prometastatic proteins S100A2 and S100A4 and survival was assessed. A preoperative nomogram based on clinical variables available before surgery and expression of these proteins was constructed and compared to traditional measures, and a postoperative nomogram. Results: High expression of either S100A2 or S100A4 was independent poor prognostic factors in a training cohort of 518 participants. These results were validated in 2 independent patient cohorts (Glasgow, n = 198; Germany, n = 468). Aberrant biomarker expression stratified the cohorts into 3 distinct prognostic groups. A preoperative nomogram incorporating S100A2 and S100A4 expression predicted survival and nomograms derived using postoperative clinicopathological variables. Conclusions: Of those patients with a poor preoperative nomogram score, approximately 50% of patients died within a year of resection. Nomograms have the potential to improve selection for surgery and neoadjuvant therapy, avoiding surgery in aggressive disease, and justifying more extensive resections in biologically favorable disease
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