Background The incidence of postural tachycardia syndrome （POTS） has been increasing in children and adolescents,while clinical characteristics of POTS in the pediatric population are not fully understood.Methods An...Background The incidence of postural tachycardia syndrome （POTS） has been increasing in children and adolescents,while clinical characteristics of POTS in the pediatric population are not fully understood.Methods An observational study was performed in 150 pediatric patients aged between 5 and 18 years who underwent head-up tilt test （HUTT） with the diagnosis of POTS at Peking University First Hospital from March 2008 to August 2013.Demographic data,clinical presentation,autonomic parameters,laboratory findings,and treatments were recorded.Results POTS in children commonly occurred in the age of 7-14 years.Dizziness （84.00％） was the most common symptom,followed by weakness （72.00％） and orthostatic syncope （62.67％）.Positive family history of orthostatic intolerance （Ol） was found in 24.64％ of children with POTS.And 33.09％ of them had preceding infection history as precipitating events.Ten percent of them suffered from orthostatic hypertension.Hyperadrenergic status was documented in 51.28％ of 39 patients who were tested for the standing norepinephrine levels.More than half of POTS patients,with 24-hour urinary sodium level ＜124 mmol/24 hours,were suitable for treatment of salt supplementation.At least 25.74％ of POTS patients were of positive acetylcholine receptor （AChR） antibody.Low iron storage in children with POTS was relatively rare.Most patients responded well to treatments,43.51％ of patients recovered,while 7.63％ of them had relapse after symptoms disappeared.Conclusions POTS is a relatively common condition with complex pathophysiology and heterogeneous clinical manifestation.A comprehensive therapeutic regimen is recommended for the treatment.展开更多
目的观察模拟失重2周后,大鼠脑动脉血管平滑肌细胞(vascular smooth muscle cells,VSMCs)L型电压依赖性钙离子通道(L-type voltage dependent calcium channel,CaL)功能的改变,以及钙通道激动剂BayK8644对通道电流的影响。方法以尾部悬...目的观察模拟失重2周后,大鼠脑动脉血管平滑肌细胞(vascular smooth muscle cells,VSMCs)L型电压依赖性钙离子通道(L-type voltage dependent calcium channel,CaL)功能的改变,以及钙通道激动剂BayK8644对通道电流的影响。方法以尾部悬吊大鼠模型模拟失重的影响。采用全细胞膜片钳记录模式,以Ba2+作为载流子,记录2周模拟失重后大鼠脑动脉VSMCs的CaL电流及钙通道激动剂Bay K 8644对其的影响,并测定相应的稳态激活与失活曲线及有关参数。结果与对照组相比,模拟失重2周后悬吊组大鼠已出现了典型的模拟失重效应,悬吊组大鼠脑动脉VSMCs的CaL的电流密度显著增加(P<0.05),且对钙通道激动剂Bay K 8644更敏感(P<0.05)。此外,与对照组相比,悬吊组大鼠脑动脉VSMCs的膜电容与接入电阻、CaL稳态失活曲线和稳态激活曲线等通道动力学特征无显著性改变。结论模拟失重2周可引起大鼠脑动脉平滑肌细胞CaL通道功能增强,这可能是模拟失重导致大鼠脑动脉血管收缩反应性增强的因素之一。展开更多
文摘Background The incidence of postural tachycardia syndrome （POTS） has been increasing in children and adolescents,while clinical characteristics of POTS in the pediatric population are not fully understood.Methods An observational study was performed in 150 pediatric patients aged between 5 and 18 years who underwent head-up tilt test （HUTT） with the diagnosis of POTS at Peking University First Hospital from March 2008 to August 2013.Demographic data,clinical presentation,autonomic parameters,laboratory findings,and treatments were recorded.Results POTS in children commonly occurred in the age of 7-14 years.Dizziness （84.00％） was the most common symptom,followed by weakness （72.00％） and orthostatic syncope （62.67％）.Positive family history of orthostatic intolerance （Ol） was found in 24.64％ of children with POTS.And 33.09％ of them had preceding infection history as precipitating events.Ten percent of them suffered from orthostatic hypertension.Hyperadrenergic status was documented in 51.28％ of 39 patients who were tested for the standing norepinephrine levels.More than half of POTS patients,with 24-hour urinary sodium level ＜124 mmol/24 hours,were suitable for treatment of salt supplementation.At least 25.74％ of POTS patients were of positive acetylcholine receptor （AChR） antibody.Low iron storage in children with POTS was relatively rare.Most patients responded well to treatments,43.51％ of patients recovered,while 7.63％ of them had relapse after symptoms disappeared.Conclusions POTS is a relatively common condition with complex pathophysiology and heterogeneous clinical manifestation.A comprehensive therapeutic regimen is recommended for the treatment.
文摘目的观察模拟失重2周后,大鼠脑动脉血管平滑肌细胞(vascular smooth muscle cells,VSMCs)L型电压依赖性钙离子通道(L-type voltage dependent calcium channel,CaL)功能的改变,以及钙通道激动剂BayK8644对通道电流的影响。方法以尾部悬吊大鼠模型模拟失重的影响。采用全细胞膜片钳记录模式,以Ba2+作为载流子,记录2周模拟失重后大鼠脑动脉VSMCs的CaL电流及钙通道激动剂Bay K 8644对其的影响,并测定相应的稳态激活与失活曲线及有关参数。结果与对照组相比,模拟失重2周后悬吊组大鼠已出现了典型的模拟失重效应,悬吊组大鼠脑动脉VSMCs的CaL的电流密度显著增加(P<0.05),且对钙通道激动剂Bay K 8644更敏感(P<0.05)。此外,与对照组相比,悬吊组大鼠脑动脉VSMCs的膜电容与接入电阻、CaL稳态失活曲线和稳态激活曲线等通道动力学特征无显著性改变。结论模拟失重2周可引起大鼠脑动脉平滑肌细胞CaL通道功能增强,这可能是模拟失重导致大鼠脑动脉血管收缩反应性增强的因素之一。
