采用磁共振示踪法探讨大鼠脑细胞间隙内物质转运清除规律

目的 采用磁共振示踪法探讨脑细胞间隙（ECS）内物质转运规律及外界刺激对其转运能力的影响。方法 将32只雄性SD大鼠随机分为尾状核-对照组、丘脑-对照组、尾状核-运动组和丘脑-疼痛组,通过立体定位技术将示踪剂Gd-DTPA导引至尾状核和丘脑区的ECS,在示踪剂注射前和注射后不同时间点进行MR扫描,直至Gd-DTPA所致的高信号消失,通过图像后处理和数学建模技术,计算示踪剂在ECS内的半衰期,采用独立样本t检验比较各组结果。结果 尾状核ECS内的Gd-DTPA可转运至邻近皮层区,丘脑ECS内Gd-DTPA的转运局限于原位,未观察到向邻近区域进行跨区域转运。尾状核-对照组、丘脑-对照组Gd-DTPA的半衰期分别为（104.30±54.12） min和（49.93±2.11） min （t=2.839,P<0.05）。尾状核-运动组Gd-DTPA的半衰期分别为（113.42±47.32） min,与尾状核-对照组比较差异无统计学意义（t=0.359,P>0.05）。丘脑-疼痛组的Gd-DTPA的半衰期为（109.40±10.33） min,较丘脑-对照组显著延长（t=15.954,P<0.05）。结论 磁共振示踪法是研究脑ECS内物质转运规律的有效手段,外界刺激可调控相关脑区ECS内物质的转运清除。     

NF2蛋白518位丝氨酸磷酸化状态对其分子内相互作用机制的结构生物学及生物化学研究

 目的  揭示NF2 (neurofibromatosis type 2)蛋白518位丝氨酸的磷酸化如何对其结构与功能进行调节。  方法  解析野生型NF2^WT(无模拟磷酸化突变)和突变型NF2^S518D(模拟518位丝氨酸被磷酸化的突变体)蛋白的晶体结构,进一步利用体外Pull-down实验及荧光共振能量转移(fluorescence resonance energy transfer,FRET)实验检测了NF2的分子内相互作用。  结果  由于NF2的C-端在结晶过程中降解,未能观察到NF2^WT和NF2^S518D两种蛋白质构象的差异,结构分析发现NF2的N-端FERM(Four-point one,Ezrin,Radixin,Moesin)结构域与已有结构报道的FERM结构域具有相似的空间构象。体外Pull-down实验证明生化实验结果提示,相对NF2^WTC-端蛋白质而言,NF2^S518D的C-端蛋白质与NF2的N-端蛋白质结合更强。FRET实验在波长525 nm处,检测到全长NF2^S518D比全长NF2^WT产生更强的FRET信号。  结论  野生型NF2^WT处于“开放”状态而模拟磷酸化的突变型NF2^S518D处于“闭合”状态。     

Apyrase减轻过敏性哮喘小鼠气道炎症及气道重塑

目的探讨apyrase(三磷酸腺苷二磷酸水解酶)对过敏性哮喘小鼠气道炎症及气道重塑的作用。方法采用C57BL/6雌性小鼠建立鸡卵清蛋白(OVA)致敏和激发的过敏性哮喘模型,并给予apyrase处理;以非致敏的同背景雌性小鼠作为对照。于最后1次激发24~48 h,完成小鼠气道高反应性测定、支气管肺泡灌洗及取肺组织。病理学方法评价肺组织气道炎症、杯状细胞及气道重塑,瑞氏吉姆莎染色并计数灌洗液的分类细胞,酶联免疫吸附法测定灌洗液细胞因子,实时定量PCR法测定肺组织转录因子(GATA3)水平。结果 Apyrase减轻哮喘小鼠肺组织嗜酸性粒细胞炎症,降低气道炎性细胞、Th2相关细胞因子及肺组织GATA3核酸水平;减轻气道上皮杯状细胞增生及胶原沉积。结论 Apyrase可减轻小鼠过敏性哮喘的气道炎症及气道重塑。     

Bio-inspired antifogging PDMS coupled micro-pillared superhydrophobic arrays and SiO2 coatings

In this work, inspired by some typical creatures from nature with superhydrophobic surfaces, a bio-inspired antifogging PDMS is designed and fabricated successfully using UV lithography and a template method. First, we fabricated an SU-8 layer with a bio-inspired micro-pillared array (MPA) using traditional UV lithography. Then, it was used as a template to fabricate a PDMS film (PF). After that, it was chemically modified with SiO₂ coatings. It was found that the PF coupled with sprayed SiO₂ coatings and a MPA have a higher water contact angle (CA) of 158° and a lower contact angle hysteresis (CAH) of less than 2°. Water drops can be separated from this bio-inspired PDMS surface within 86.8 ms. More importantly, this film’s antifogging property is superior, with a recovery time of less than 13 s, which is significantly superior to that of the flat PF and the PF with the MPA. Afterwards, FTIR was applied to analyse the surface chemistry features and suggested that the bio-inspired PF has extremely low surface tension. So, it can be confirmed that an excellent superhydrophobic antifogging property has been achieved on the surface of the PF. Meanwhile, the microscopic and macroscopic dynamic movement behaviour of the fog drops was further observed. Then, the underlying antifogging mechanism was also revealed. These properties mainly benefit from the coupling effect of intermolecular attraction of droplets, chemical compositions (nanometre roughness SiO₂) and the physical structures (MPA). The investigations offer a promising way to handily design and fabricate multiscale hierarchical structures on polymers and other materials. More importantly, these findings suggest great potential value for specific antifogging applications in display devices, transport, agricultural greenhouses, food packaging and solar products, especially in continuous harsh fogging conditions.

Inspired by nature, a bio-inspired antifogging PDMS is designed and fabricated successfully using UV lithography and a template method. It achieves an excellent superhydrophobic antifogging property, which benefits from a coupling effect.     

预防医学专业学生关于问卷调查技术的相关态度及其影响因素

目的 从问卷调查技术认知、实践的角度,探讨预防医学专业学生调查问卷技术相关态度的影响因素,从而为有针对性地进行预防医学专业有关问卷调查技术教学改革提供参考.方法 对河北省2所高校公共卫生学院的预防医学专业五年级全体本科生进行调查,共计141人.自行设计调查问卷.影响因素分析采用Logistic多元回归模型.结果 调查对象认为问卷调查技术在获取人群疾病和健康信息方面的作用“很大”或“较大”者占75.17％,认为问卷调查研究结果“真实”或“较真实”者占65.25％,有58.87％认为调查问卷的科学性“很高”或“较高”,有62.41％认为开展问卷调查“很难”或“较难”.预防医学专业学生对问卷调查技术作用的态度与其调查问卷测量属性知晓情况、问卷调查基本原则的知晓情况有关,对问卷调查研究结果真实性的态度与问卷调查基本原则的知晓情况、参加问卷调查设计次数有关,参加问卷调查设计次数与学生对调查问卷工具科学性态度有关,学校、性别、调查问卷测量属性知晓情况与问卷调查研究难度态度有关.结论 预防医学医学生对问卷调查技术的认知、实践水平对其问卷调查技术相关态度有影响.建议高校加强问卷调查技术跨学科综合理论与实践教学,提升学生对问卷调查技术的正向态度.     

不同培训方式对医护人员手卫生依从性的影响

目的采用常规培训与联合手污染状况调查的培训方法对医护人员进行宣教,评价两种方法对医护人员手卫生依从性的影响。方法 2013年11月—2014年4月,选择心血管内科两个病房的全体医护人员作为宣教对象并分别设为实验组与对照组。培训前1个月对两组进行手卫生依从性摸底调查,培训后第1个月两组均采用常规宣教培训方法,第2个月至第5个月在常规宣教培训方法的基础上实验组增加手卫生污染状况调查培训方法,分别统计两组医护人员的手卫生依从率。结果培训前实验组与对照组手卫生依从率分别为42.63%(107/251)、41.80%(102/244),差异无统计学意义(P0.05);培训后第1和第2个月,实验组医护人员手卫生依从率分别为55.70%(132/237)、63.11%(154/244),对照组分别为56.52%(130/230)、62.61%(149/238),与培训前比较,差异均有统计学意义(均P0.05),但两组间差异无统计学意义(P0.05);培训后第3个月至第5个月,实验组医护人员手卫生依从率分别为60.73%(150/247)、61.44%(145/236)、61.22%(150/245),对照组分别为51.68%(123/238)、51.02%(125/245)、52.32%(124/237),两组间差异有统计学意义(P0.05)。结论采用常规培训同时联合手污染状况调查的培训方式可以更好地促进医护人员手卫生依从性的提高。     

Isolated ventricular apical hypoplasia: A report of four cases and literature review

Isolated ventricular apical hypoplasia (IVAH) is a rare congenital cardiac anomaly, with clinical manifestations depending on the age of the patient, ranging from no symptoms in children to congestive heart failure or even malignant tachycardia in adults. Herein, we describe the clinical and anatomical findings in four cases with hypoplasia of the right or left ventricular apex, and we discuss the possible mechanisms and differential diagnosis of this malformation. Echocardiography is a rapidly accessible, low cost, noninvasive technique for the detection and evaluation of IVAH.     

Metallothionein 1 h tumour suppressor activity in prostate cancer is mediated by euchromatin methyltransferase 1

Metallothioneins (MTs) are a group of metal binding proteins thought to play a role in the detoxification of heavy metals. Here we showed by microarray and validation analyses that MT1h, a member of MT, is down‐regulated in many human malignancies. Low expression of MT1h was associated with poor clinical outcomes in both prostate and liver cancer. We found that the promoter region of MT1h was hypermethylated in cancer and that demethylation of the MT1h promoter reversed the suppression of MT1h expression. Forced expression of MT1h induced cell growth arrest, suppressed colony formation, retarded migration, and reduced invasion. SCID mice with tumour xenografts with inducible MT1h expression had lower tumour volumes as well as fewer metastases and deaths than uninduced controls. MT1h was found to interact with euchromatin histone methyltransferase 1 (EHMT1) and enhanced its methyltransferase activity on histone 3. Knocking down of EHMT1 or a mutation in MT1h that abrogates its interaction with EHMT1 abrogated MT1h tumour suppressor activity. This demonstrates tumour suppressor activity in a heavy metal binding protein that is dependent on activation of histone methylation. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

miR-183 promotes radioresistance of lung adenocarcinoma H1299 cells via epithelial-mesenchymal transition

Lung adenocarcinomas are usually sensitive to radiation therapy, but some develop resistance. Radiation resistance can lead to poor patient prognosis. Studies have shown that lung adenocarcinoma cells (H1299 cells) can develop radioresistance through epithelial-mesenchymal transition (EMT), and this process is regulated by miRNAs. However, it is unclear which miRNAs are involved in the process of EMT. In our present study, we found that miR-183 expression was increased in a radioresistant lung adenocarcinoma cell line (H1299R cells). We then explored the regulatory mechanism of miR-183 and found that it may be involved in the regulation of zinc finger E-box-binding homeobox 1 (ZEB1) expression and mediate EMT in lung adenocarcinoma cells. qPCR results showed that miR-183, ZEB1, and vimentin were highly expressed in H1299R cells, whereas no difference was observed in E-cadherin expression. Western blot results showed that ZEB1 and vimentin were highly expressed in H1299R cells, while E-cadherin expression was decreased. When miR-183 expression was inhibited in H1299R cells, radiation resistance, proliferation, and cell migration were decreased. The expression of ZEB1 and vimentin in H1299R cells was decreased, while the expression of E-cadherin was increased. Moreover, miR-183 overexpression in H1299 cells enhanced radiation resistance, proliferative capacity, and cell migration ability. The expression of ZEB1 and vimentin in H1299 cells was increased, while that of E-cadherin was decreased. In conclusion, miR-183 may promote EMT and radioresistance in H1299 cells, and targeting the miR-183-ZEB1 signaling pathway may be a promising approach for lung cancer treatment.