346 research outputs found

    Bird Strike Mitigation, Spring 2020

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    Bird Strike Mitigation Project for Sustainability Exchange, Washington University in St. Louis, Spring 202

    Contrasting Effects of Lower Body Positive Pressure on Upper Airways Resistance and Partial Pressure of Carbon Dioxide in Men With Heart Failure and Obstructive or Central Sleep Apnea

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    ObjectivesThis study sought to test the effects of rostral fluid displacement from the legs on transpharyngeal resistance (Rph), minute volume of ventilation (Vmin), and partial pressure of carbon dioxide (PCO2) in men with heart failure (HF) and either obstructive (OSA) or central sleep apnea (CSA).BackgroundOvernight rostral fluid shift relates to severity of OSA and CSA in men with HF. Rostral fluid displacement may facilitate OSA if it shifts into the neck and increases Rph, because pharyngeal obstruction causes OSA. Rostral fluid displacement may also facilitate CSA if it shifts into the lungs and induces reflex augmentation of ventilation and reduces PCO2, because a decrease in PCO2 below the apnea threshold causes CSA.MethodsMen with HF were divided into those with mainly OSA (obstructive-dominant, n = 18) and those with mainly CSA (central-dominant, n = 10). While patients were supine, antishock trousers were deflated (control) or inflated for 15 min (lower body positive pressure [LBPP]) in random order.ResultsLBPP reduced leg fluid volume and increased neck circumference in both obstructive- and central-dominant groups. However, in contrast to the obstructive-dominant group in whom LBPP induced an increase in Rph, a decrease in Vmin, and an increase in PCO2, in the central-dominant group, LBPP induced a reduction in Rph, an increase in Vmin, and a reduction in PCO2.ConclusionsThese findings suggest mechanisms by which rostral fluid shift contributes to the pathogenesis of OSA and CSA in men with HF. Rostral fluid shift could facilitate OSA if it induces pharyngeal obstruction, but could also facilitate CSA if it augments ventilation and lowers PCO2

    Impact of obstructive sleep apnea on the occurrence of restenosis after elective percutaneous coronary intervention in ischemic heart disease

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    <p>Abstract</p> <p>Rationale</p> <p>There is growing evidence that obstructive sleep apnea is associated with coronary artery disease. However, there are no data on the course of coronary stenosis after percutaneous coronary intervention in patients with obstructive sleep apnea.</p> <p>Objectives</p> <p>To determine whether sleep apnea is associated with increased late lumen loss and restenosis after percutaneous coronary intervention.</p> <p>Methods</p> <p>78 patients with coronary artery disease who underwent elective percutaneous coronary intervention were divided in 2 groups: 43 patients with an apnea hypopnea – Index < 10/h (group I) and 35 pt. with obstructive sleep apnea and an AHI > 10/h (group II). Late lumen loss, a marker of restenosis, was determined using quantitative coronary angiography after 6.9 ± 3.1 months.</p> <p>Main results</p> <p>Angiographic restenosis (>50% luminal diameter), was present in 6 (14%) of group I and in 9 (25%) of group II (p = 0.11). Late lumen loss was significant higher in pt. with an AHI > 10/h (0.7 ± 0.69 mm vs. 0.38 ± 0.37 mm, p = 0.01). Among these 35 patients, 21(60%) used their CPAP devices regularly. There was a marginally lower late lumen loss in treated patients, nevertheless, this difference did not reach statistical significance (0.57 ± 0.47 mm vs. 0.99 ± 0.86 mm, p = 0.08). There was no difference in late lumen loss between treated patients and the group I (p = 0.206).</p> <p>Conclusion</p> <p>In summary, patients with OSA and coronary artery disease have a higher degree of late lumen loss, which is a marker of restenosis and vessel remodeling after elective percutaneous intervention.</p

    BRASSICA NAPUSヒンシュ TOPAS ニ オケル レンゾクテキハイケイセイ オヨビ ニジハイ カラ ノ ショクブツタイサイセイケイ

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    Brassica napus品種`Topas\u27における連続的な二次胚形成及び植物体再生系の確立を試みた。熱ショックによって未熟種子胚より誘導した二次胚を,植物成長調節物質無添加のB5培地へ継代した。培養後70%の二次胚において,徒長した胚軸の表面に次代の二次胚が直接形成された。これら二次胚を同様に継代培養した結果,約70%の胚より新たな二次胚が形成され,次胚形成能が継代培養を通じて維持されていたことが示された。二次胚に10μMアブシジン酸(ABA)処理をした結果,胚は乾燥耐性を獲得し,60%の二次胚が乾燥後においても生育しその全てが正常に再生した。一方,ABA処理後,乾燥処理を行わなかった胚は胚軸が徒長する異常な生育を示し,ABA無処理胚は乾燥処理によって全て枯死した。A method for continuous secondary embryo formation and plant regeneration in Brassica napus cv. `Topas\u27 is described. Secondary embryos that emerged from immature zygotic embryos via heat shock were separated and subcultured onto B5 plant growth regulator-free medium. Most secondary embryos (i.e. 70%) produced secondary embryos in a subsequent generation directly on the surface of elongated hypocotyls. Similarly, about 70% of the secondary embryos formed newly produced secondary embryos in a subsequent generation after subculturing, and the embryogenic potential of these secondary embryos has been maintained by repetitive subculture. The application of 10μM abscisic acid (ABA) induced desiccation tolerance in secondary embryos. Consequently, 60% of the desiccated embryos grew, all of which regenerated into normal plants. On the other hand, ABA-treated secondary embryos without desiccation treatment grew abnormally having an elongated hypocotyl, and all secondary embryos not treated with ABA lost their viability after desiccation

    Adaptive servoventilation improves cardiac function and respiratory stability

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    Cheyne–Stokes respiration (CSR) in patients with chronic heart failure (CHF) is of major prognostic impact and expresses respiratory instability. Other parameters are daytime pCO2, VE/VCO2-slope during exercise, exertional oscillatory ventilation (EOV), and increased sensitivity of central CO2 receptors. Adaptive servoventilation (ASV) was introduced to specifically treat CSR in CHF. Aim of this study was to investigate ASV effects on CSR, cardiac function, and respiratory stability. A total of 105 patients with CHF (NYHA ≥ II, left ventricular ejection fraction (EF) ≤ 40%) and CSR (apnoea–hypopnoea index ≥ 15/h) met inclusion criteria. According to adherence to ASV treatment (follow-up of 6.7 ± 3.2 months) this group was divided into controls (rejection of ASV treatment or usage <50% of nights possible and/or <4 h/night; n = 59) and ASV (n = 56) adhered patients. In the ASV group, ventilator therapy was able to effectively treat CSR. In contrast to controls, NYHA class, EF, oxygen uptake, 6-min walking distance, and NT-proBNP improved significantly. Moreover, exclusively in these patients pCO2, VE/VCO2-slope during exercise, EOV, and central CO2 receptor sensitivity improved. In CHF patients with CSR, ASV might be able to improve parameters of SDB, cardiac function, and respiratory stability

    Sympatho-renal axis in chronic disease

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    Essential hypertension, insulin resistance, heart failure, congestion, diuretic resistance, and functional renal disease are all characterized by excessive central sympathetic drive. The contribution of the kidney’s somatic afferent nerves, as an underlying cause of elevated central sympathetic drive, and the consequences of excessive efferent sympathetic signals to the kidney itself, as well as other organs, identify the renal sympathetic nerves as a uniquely logical therapeutic target for diseases linked by excessive central sympathetic drive. Clinical studies of renal denervation in patients with resistant hypertension using an endovascular radiofrequency ablation methodology have exposed the sympathetic link between these conditions. Renal denervation could be expected to simultaneously affect blood pressure, insulin resistance, sleep disorders, congestion in heart failure, cardiorenal syndrome and diuretic resistance. The striking epidemiologic evidence for coexistence of these disorders suggests common causal pathways. Chronic activation of the sympathetic nervous system has been associated with components of the metabolic syndrome, such as blood pressure elevation, obesity, dyslipidemia, and impaired fasting glucose with hyperinsulinemia. Over 50% of patients with essential hypertension are hyperinsulinemic, regardless of whether they are untreated or in a stable program of treatment. Insulin resistance is related to sympathetic drive via a bidirectional mechanism. In this manuscript, we review the data that suggests that selective impairment of renal somatic afferent and sympathetic efferent nerves in patients with resistant hypertension both reduces markers of central sympathetic drive and favorably impacts diseases linked through central sympathetics—insulin resistance, heart failure, congestion, diuretic resistance, and cardiorenal disorders
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