Membrane ionic currents and properties of freshly dissociated rat brainstem neurons

It is well known that neuronal firing properties are determined by synaptic inputs and inherent membrane functions such as specific ionic currents. To characterize the ionic currents of brainstem cardio-respiratory neurons, cells from the hypoglossal (XII) nucleus and the dorsal motor nucleus of the vagus (DMX) were freshly dissociated and membrane ionic currents were studied under whole-cell voltage and current clamp. Both of these neurons showed a TTX-sensitive Na⁺ current with a much larger current density in XII than DMX neurons. This Na⁺ current had two (fast and slow) distinct inactivation decay components. The ratio of the magnitudes of the fast to slow component was roughly two-fold greater in DMX than in XII cells. Both DMX and XII neurons also showed a high voltage-activated Ca²⁺ current, but this current density was significantly greater (three-fold) in DMX than XII neurons. A relatively small amount of low-voltage activated Ca²⁺ current was also observed in DMX neurons, but not in the majority of XII cells. A transient and a sustained outward current components were observed in DMX cells, but only sustained currents were present in XII neurons. These outward currents had a reversal potential of about − 70 mV with 3 mM external K⁺ and −30 mV with 25 mM K⁺, and substitution of K⁺ with cesium and tetraethylammonium suppressed more than 90% the outward currents, indicating that most outward currents were carried by K⁺. The transient outward current consisted of two components with onesensitive to 4-aminopyridine and the other to intracellular Ca²⁺. In XII neurons, BRL 38227 (lemakalim), an ATP-sensitive K⁺ (K_ATP) channel activator, increased the sustained K⁺ currents by 10% of control, and glibenclamide, a K_ATP channel blocker, decreased the sustained K⁺ currents by 20%. Evidence for the presence of an inward rectifier K⁺ current was also obtained from both XII and DMX neurons. These results on XII and DMX neurons indicate that (1) the methods used to dissociate neurons provide a useful means to overcome voltage clamp technical difficulties; (2) ion channel characteristics such as density and biophysical properties of DMX neurons are very different from those of XII neurons; and (3) several newly discovered membrane ionic currents are present in these cells.     

Impact of Dissection after Drug-Coated Balloon Treatment of De Novo Coronary Lesions: Angiographic and Clinical Outcomes

PurposeDissection after plain balloon angioplasty is required to achieve adequate luminal area; however, it is associated with a high risk of vascular events. This study aimed to examine the relationship between non-flow limiting coronary dissections and subsequent lumen loss and long-term clinical outcomes following successful drug-coated balloon (DCB) treatment of de novo coronary lesions.Materials and MethodsA total of 227 patients with good distal flow (Thrombolysis in Myocardial Infarction flow grade 3) following DCB treatment were retrospectively enrolled and stratified according to the presence or absence of a non-flow limiting dissection. The primary endpoint was late lumen loss (LLL) at 6-month angiography, and the secondary endpoint was target vessel failure (TVF, a composite of cardiac death, target vessel myocardial infarction, target vessel revascularization, and target vessel thrombosis).ResultsThe cohort consisted of 95 patients with and 132 patients without a dissection. There were no between-group differences in LLL (90.8%) returning for angiography at 6 months (0.05±0.19 mm in non-dissection and 0.05±0.30 mm in dissection group, p=0.886) or in TVF (6.8% in non-dissection and 8.4% in dissection group, p=0.799) at a median follow-up of 3.4 years. In a multivariate analysis, the presence of dissection and its severity were not associated with LLL or TVF. Almost dissections (93.9%) were completely healed, and there was no newly developed dissection at 6-month angiography.ConclusionThe presence of a dissection following successful DCB treatment of a de novo coronary lesion may not be associated with an increased risk of LLL or TVF (Impact of Drug-coated Balloon Treatment in de Novo Coronary Lesion; {"type":"clinical-trial","attrs":{"text":"NCT04619277","term_id":"NCT04619277"}}NCT04619277).     

The study of tuberculosis outbreak in a high school—Shanghai,China, 2017–2018

Journal of Public Health - To investigate the attack rate of active tuberculosis (TB) cases and detection rate of latent tuberculosis infection (LTBI) cases, and to identify possible factors...     

重点高中生的心理状态与高考成绩的相关性研究

目的;了解重点高中学生的心理状态与高考成绩之间的关系。方法：以398例应届生为对象,应用16PF人格测验,气质测量工具（STI,TTI）及焦虑自评量表（SAS）,对考生进行测试分析,结果：文理科学生的16PF的人格特质有明显的差别,判别分析和多因素回归分析显示16PF人格特质中的Q1因素（实验性F＝8．76,P＜0．01）,Q2因素（独立性F＝8．23,P＜0．01）,与高考成绩呈正相关,与M因素（幻想性F＝4．88,P＜0．01）,呈负相关;气质中的神经过程灵活性（F＝8．15,P＜0．01）和时间特质中的灵活性（F＝12．36,P＜0．01）与高才成绩呈正相关。结论：高考生的实验性,独立性高分及幻想性低分的个性特质和气质上的灵活性有助于高考成绩的发挥,学生文理科分班宜参考学生人格特质这一特点,。     

乙型肝炎病毒垂直传播研究进展乙型肝炎病毒垂直传播研究进展

迄今,在已知的人类病毒性肝炎中,乙、丙、丁、戊、庚等5种肝炎病 毒已被证实能经垂直传播而导致婴儿罹患肝炎综合征。最近报告甲型肝炎病毒(HAV)也能引 起母婴垂直传播［1～2］。但由日本学者Nishizawa等(1997)发现的输血传播病毒(T TV)经多项研究表明垂直传播机率不大［3～5］。本文介绍近年来对乙型肝炎病毒( HBV)垂直传播研究所取得的一些进展。 1　HBV垂直传播机率 　　婴幼儿中80%的HBV感染者是经垂直传播而得。HBsAg和HBeAg阳性母亲有80%～90%的可能会将 其病毒传给后代,其中85%以上会成为HBsAg携带者,而HBsAg(+)HBeAg(-)母亲的HBV传播率 只有2%～5%［6］。Soderstrom等［7］报告在HBV低度流行的瑞典检测了93 例儿童,其中90例(96.8%)HBV DNA(+),54例(58%)HBeAg(+)。93例儿童有81例(87%)来源于 高/ 中度HBV流行区,12例(13%)     

不同材料双J管对兔输尿管的影响

目的：观察不同材料双J管对兔输尿管的影响。方法：本实验通过三种双J管置于15例（每一种双J管5例）正常兔的输尿管内,6周后观察其对输尿管上皮的损伤,输尿管的反应变化,双J管长壳的程度,置管前后肾盂压力的变化,结果：三种双J管均产生上皮细胞的损伤,二种国产双J管所引起的输尿管反应性较小。而进口双J管较重,与之相反,国产双J管长结古石的程度远较进口双J管严重（P＜0．05）,置管6周后与管前比较肾盂压力无明显变化（P＜0．05）,结论：国产双J管有较严重的长结石的倾向,但输尿管的反应性变化较小,适合于短时间置管,进口双J管的输尿管反应性变化较重,便有较长长结石倾向,比较适合于篚置管,尽管这些为动物实验所得结果,但也可能与临床有关系。     

薄层扫描法测定安神宁康胶囊中黄芪甲甙的含量

目的：建立测定安神宁康胶囊中黄芪甲甙含量的方法。方法：以氯仿——甲醇——水（65:35:10)的下层为展开剂,用双波长薄层扫描仪测定。结果：黄芪甲甙在1.049μg-5.245μg与峰面积积分值,呈良好的线性关系（r=0.9993,n=5),平均回收率为96.24%。结论：为控制安神宁康胶囊中黄芪甲甙的含量提供了方法。