72 research outputs found

    Endoscopic Management of Pediatric Airway and Esophageal Foreign Bodies

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    The use of endoscopy is critical to the management of pediatric tracheobronchial and esophageal foreign bodies. Children may present with nonspecific symptoms, and the diagnosis can be difficult when the ingestion or aspiration events go unwitnessed. Advances in endoscopic techniques and the use of optical graspers in the removal of foreign bodies in children have helped decrease morbidity and mortality. In this chapter, the history, clinical presentations, workup, and management for pediatric aerodigestive foreign bodies are discussed

    Blockade of TRPM7 Channel Activity and Cell Death by Inhibitors of 5-Lipoxygenase

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    TRPM7 is a ubiquitous divalent-selective ion channel with its own kinase domain. Recent studies have shown that suppression of TRPM7 protein expression by RNA interference increases resistance to ischemia-induced neuronal cell death in vivo and in vitro, making the channel a potentially attractive pharmacological target for molecular intervention. Here, we report the identification of the 5-lipoxygenase inhibitors, NDGA, AA861, and MK886, as potent blockers of the TRPM7 channel. Using a cell-based assay, application of these compounds prevented cell rounding caused by overexpression of TRPM7 in HEK-293 cells, whereas inhibitors of 12-lipoxygenase and 15-lipoxygenase did not prevent the change in cell morphology. Application of the 5-lipoxygenase inhibitors blocked heterologously expressed TRPM7 whole-cell currents without affecting the protein's expression level or its cell surface concentration. All three inhibitors were also effective in blocking the native TRPM7 current in HEK-293 cells. However, two other 5-lipoxygenase specific inhibitors, 5,6-dehydro-arachidonic acid and zileuton, were ineffective in suppressing TRPM7 channel activity. Targeted knockdown of 5-lipoxygenase did not reduce TRPM7 whole-cell currents. In addition, application of 5-hydroperoxyeicosatetraenoic acid (5-HPETE), the product of 5-lipoxygenase, or 5-HPETE's downstream metabolites, leukotriene B4 and leukotriene D4, did not stimulate TRPM7 channel activity. These data suggested that NDGA, AA861, and MK886 reduced the TRPM7 channel activity independent of their effect on 5-lipoxygenase activity. Application of AA861 and NDGA reduced cell death for cells overexpressing TRPM7 cultured in low extracellular divalent cations. Moreover, treatment of HEK-293 cells with AA861 increased cell resistance to apoptotic stimuli to a level similar to that obtained for cells in which TRPM7 was knocked down by RNA interference. In conclusion, NDGA, AA861, and MK886 are potent blockers of the TRPM7 channel capable of attenuating TRPM7's function during cell stress, making them effective tools for the biophysical characterization and suppression of TRPM7 channel conductance in vivo

    Impact of Cosmetic Lotions on Nanoparticle Penetration through ex Vivo C57BL/6 Hairless Mouse and Human Skin: A Comparison Study

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    Understanding the interactions of nanoparticles (NPs) with skin is important from a consumer and occupational health and safety perspective, as well as for the design of effective NP-based transdermal therapeutics. Despite intense efforts to elucidate the conditions that permit NP penetration, there remains a lack of translatable results from animal models to human skin. The objectives of this study are to investigate the impact of common skin lotions on NP penetration and to quantify penetration differences of quantum dot (QD) NPs between freshly excised human and mouse skin. QDs were mixed in seven different vehicles, including five commercial skin lotions. These were topically applied to skin using two exposure methods; a petri dish protocol and a Franz diffusion cell protocol. QD presence in the skin was quantified using Confocal Laser Scanning Microscopy. Results show that the commercial vehicles can significantly impact QD penetration in both mouse and human skin. Lotions that contain alpha hydroxyl acids (AHA) facilitated NP penetration. Lower QD signal was observed in skin studied using a Franz cell. Freshly excised human skin was also studied immediately after the sub-cutaneous fat removal process, then after 24 h rest ex vivo. Resting human skin 24 h prior to QD exposure significantly reduced epidermal presence. This study exemplifies how application vehicles, skin processing and the exposure protocol can affect QD penetration results and the conclusions that maybe drawn between skin models

    Strategies for high efficiency and stability in biogas-fuelled small engines

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    This work assesses the performance of small biogas-fuelled engines and explores high-efficiency strategies for power generation in the very low power range of less than 1000 W. Experiments were performed on a small 95-cc, single-cylinder, four-stroke spark-ignition engine operating on biogas. The engine was operated in two modes, i.e., `premixed' and `fuel injection' modes, using both single and dual spark plug configurations. Measurements of in-cylinder pressure, crank angle, brake power, air and fuel flow rates, and exhaust emissions were conducted. Cycle-to-cycle variations in engine in-cylinder pressure and power were also studied and assessed quantitatively for various loading conditions. Results suggest that biogas combustion can be fairly sensitive to the ignition strategies thereby affecting the power output and efficiency. Further, results indicate that continuous fuel injection shows superior performance compared to the premixed case especially at low loads owing to possible charge stratification in the engine cylinder. Overall, this study has demonstrated for the first time that a combination of technologies such as lean burn, fuel injection, and dual spark plug ignition can provide highly efficient and stable operation in a biogas-fuelled small S.I. engine, especially in the low power range of 450-1000W. (C) 2014 Elsevier Inc. All rights reserved

    Sleep-disordered breathing and reaction time in children

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    Mohammed Hakim,1 Shabana Zainab Shafy,1 Rebecca Miller,1 Kris R Jatana,2 Mark Splaingard,3 Dmitry Tumin,1 Joseph D Tobias,1,4 Vidya T Raman1,4 1Department of Anesthesiology & Pain Medicine, Nationwide Children’s Hospital, Columbus, OH, USA; 2Department of Pediatric Otorhinolaryngology, Nationwide Children’s Hospital, Columbus, OH, USA; 3Department of Sleep Disorders Centre, Nationwide Children’s Hospital, Columbus, OH, USA; 4Department of Anesthesiology & Pain Medicine, Ohio State University, Columbus, OH, USA Background: The incidence of obstructive sleep apnea (OSA) and sleep-disordered breathing (SDB) in children exceeds the availability of polysomnography (PSG) to definitively diagnose OSA and identify children at higher risk of perioperative complications. As sleep deficits are associated with slower reaction times (RTs), measuring RT may be a cost-effective approach to objectively identify SDB symptoms. Aim: The aim of this study is to compare RT on a standard 10-minute psychomotor vigilance test (PVT) based on children’s history of OSA/SDB. Methods : Children, 6–11 years of age, were enrolled from two different clinical groups. The SDB group included children undergoing adenotonsillectomy with a clinical history of SDB, OSA, or snoring. The control group included children with no history of SDB, OSA, or snoring who were scheduled for surgery other than adenotonsillectomy. RT was measured via 10-minute PVT (Ambulatory Monitoring Inc., Ardsley, NY, USA). Median RT was calculated for each patient based on all responses to stimuli during the PVT assessment and was compared to published age-sex-specific norms. The proportion of children exceeding RT norms was compared between study groups. Results: The study included 72 patients (36/36 male/female, median age 7 years), 46 with SDB and 26 without SDB. There was no difference in the RT between the two groups. Fifty-four percent of patients with SDB exceeded norms for median RT vs 42% of control patients (95% CI of difference: – 12, 36; P=0.326). Conclusion: Approximately half of the patients in both groups exceeded published norms for median RT on PVT. Despite its convenience, measurement of RT did not distinguish between patients with probable SDB/OSA for preoperative risk stratification. Keywords: psychomotor vigilance test, obstructive sleep apnea, anesthesia, polysomnography, sleep-disordered breathin

    ModelDrivenGuide: An Approach for Implementing NoSQL Schemas

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