儿童晕厥临床诊治研究的发展与未来

儿童晕厥在临床常见,严重影响儿童的身心健康.儿童晕厥诊断关键技术的建立、诊断程序及个体化治疗新策略的提出,显著提高了儿童晕厥的诊治水平.基于研究成果,我国先后制定了多部儿童晕厥诊治指南与专家共识,并在国际期刊颁布了儿童和青少年晕厥指南,充分发挥了中国在国际儿童晕厥诊治领域的引领作用.今后尚需进一步开展儿童晕厥的流行病学研究,优化儿童晕厥预警体系以及干预与预防新策略,进一步推进儿童晕厥事业的发展.     

Estimation of phase signal change in neuronal current MRI for evoke response of tactile detection with realistic somatosensory laminar network model

Magnetic field generated by neuronal activity could alter magnetic resonance imaging (MRI) signals but detection of such signal is under debate. Previous researches proposed that magnitude signal change is below current detectable level, but phase signal change (PSC) may be measurable with current MRI systems. Optimal imaging parameters like echo time, voxel size and external field direction, could increase the probability of detection of this small signal change. We simulate a voxel of cortical column to determine effect of such parameters on PSC signal. We extended a laminar network model for somatosensory cortex to find neuronal current in each segment of pyramidal neurons (PN). 60,000 PNs of simulated network were positioned randomly in a voxel. Biot–savart law applied to calculate neuronal magnetic field and additional phase. The procedure repeated for eleven neuronal arrangements in the voxel. PSC signal variation with the echo time and voxel size was assessed. The simulated results show that PSC signal increases with echo time, especially 100/80 ms after stimulus for gradient echo/spin echo sequence. It can be up to 0.1 mrad for echo time = 175 ms and voxel size = 1.48 × 1.48 × 2.18 mm³. With echo time less than 25 ms after stimulus, it was just acquired effects of physiological noise on PSC signal. The absolute value of the signal increased with decrease of voxel size, but its components had complex variation. External field orthogonal to local surface of cortex maximizes the signal. Expected PSC signal for tactile detection in the somatosensory cortex increase with echo time and have no oscillation.     

儿科诊断性X线扫描家属知情与接受现状调查

目的:了解建德市基层医院儿科门诊进行X线扫描治疗中,家属对X射线检查的知情同意与接受现状。方法:随机抽取建德市属3家公立综合性医院共60位接受X线扫描的儿童患者家属为调查对象,发放自制调查问卷并统计分析。结果:55位(91.67%)患者表示治疗前主治医生只告知了X射线是诊断性检查,没有具体告知X射线的危害性;18位(30%)的患者家属不清楚辐射会对人体有损害,42位(70%)不清楚或不注意辐射警示标志,更不会主动要求防护措施,学历水平较高者及有从事医务工作背景者接受X射线检查的为12人(20%),明显低于学历水平低者或没有从事医务工作背景者的46人(76.67%),不知可否接受的有2人(3.33%)(P<0.001)。结论:基层医院儿科诊断性X射线扫描前的知情同意告知仍需加强,儿科放射检查偏多,应避免并加强宣传和教育。     

孟鲁司特治疗呼吸道合胞病毒毛细支气管炎症状及反复喘息疗效研究

背景　呼吸道合胞病毒（RSV）毛细支气管炎易出现反复喘息，且下呼吸道分泌物中半胱氨酸白三烯（CysLTs）水平升高。而孟鲁司特是一种白三烯受体拮抗剂，关于其治疗RSV毛细支气管炎症状的研究相对较少。目的　探讨孟鲁司特改善婴幼儿RSV毛细支气管炎后症状及减轻反复喘息发作的有效性和安全性。方法　2015年6月-2017年6月连续纳入在潍坊市妇幼保健院出院的RSV毛细支气管炎患儿，随机分为治疗组、对照组。Ⅰ期，治疗组：口服孟鲁司特颗粒（4 mg）12周，1次/d；对照组：口服安慰剂12周，1次/d。对两组无症状天数、个人日记评分进行评估。随访9个月（Ⅱ期），观察Ⅰ+Ⅱ期反复喘息人数和医疗资源应用情况等。依据意向性分析（ITT）原则，应用全分析集（FAS）分析数据。结果　共纳入研究对象186例，治疗组92例，对照组94例。治疗组完成Ⅰ期研究的患儿为89例，对照组为90例；治疗组完成Ⅰ+Ⅱ期的患儿为84例，对照组为86例。治疗组平均依从性为97.8%（7 560/7 728），对照组平均依从性为97.4%（7 690/7 896），两组患儿平均依从性比较，差异无统计学意义（χ2=3.16，P=0.07）。在Ⅰ期研究期间，两组无症状天数、日间无症状天数、夜间无症状天数、个人日记评分比较，差异均无统计学意义（P>0.05）。在整个研究过程中（Ⅰ+Ⅱ期），治疗组RSV毛细支气管炎喘息复发人数少于对照组（P<0.05），治疗组喘息患儿出现2次及以上喘息比例低于对照组（χ2=5.14，P=0.02）。Ⅰ+Ⅱ期研究期间治疗组医疗资源应用人数、β-受体激动剂应用人数、糖皮质激素应用人数、住院人数低于对照组（P<0.05）。在事后亚组分析中，治疗组有湿疹史与父母哮喘史的患儿中无症状天数〔（49.7±20.2）、（51.3±20.9）d〕多于对照组〔（36.3±20.4）、（37.8±19.3）d〕（t=2.19，P=0.03；t=2.24，P=0.03）。整个研究过程中没有患儿因不良反应退出研究，两组间胃肠道紊乱、皮疹、转氨酶升高发生率比较，差异均无统计学意义（χ2=0.23，P=0.63；χ2=0.03，P=0.86；χ2=0.15，P=0.69）。结论　口服孟鲁司特（4 mg）12周不能改善RSV毛细支气管炎患儿呼吸道症状，但能降低患儿反复喘息发作次数。口服孟鲁司特（4 mg）有一定效果且安全。     

Binding mode of conformations and structure-based pharmacophore development for farnesyltransferase inhibitors

Farnesyltransferase (FTase) is one of the prenyltransferase family enzymes that catalyse the transfer of 15-membered isoprenoid (farnesyl) moiety to the cysteine of CAAX motif-containing proteins including Rho and Ras family of G proteins. Inhibitors of FTase act as drugs for cancer, malaria, progeria and other diseases. In the present investigation, we have developed two structure-based pharmacophore models from protein–ligand complex (3E33 and 3E37) obtained from the protein data bank. Molecular dynamics (MD) simulations were performed on the complexes, and different conformers of the same complex were generated. These conformers were undergone protein–ligand interaction fingerprint (PLIF) analysis, and the fingerprint bits have been used for structure-based pharmacophore model development. The PLIF results showed that Lys164, Tyr166, TrpB106 and TyrB361 are the major interacting residues in both the complexes. The RMSD and RMSF analyses on the MD-simulated systems showed that the absence of FPP in the complex 3E37 has significant effect in the conformational changes of the ligands. During this conformational change, some interactions between the protein and the ligands are lost, but regained after some simulations (after 2 ns). The structure-based pharmacophore models showed that the hydrophobic and acceptor contours are predominantly present in the models. The pharmacophore models were validated using reference compounds, which significantly identified as HITs with smaller RMSD values. The developed structure-based pharmacophore models are significant, and the methodology used in this study is novel from the existing methods (the original X-ray crystallographic coordination of the ligands is used for the model building). In our study, along with the original coordination of the ligand, different conformers of the same complex (protein–ligand) are used. It concluded that the developed methodology is significant for the virtual screening of novel molecules on different targets.