50岁及以上人群手握力与空气污染的关联研究

目的 分析室内、外空气污染与≥50岁人群手握力的关联。方法 采用WHO全球老龄化与成人健康研究中国项目第一轮基线调查,室外空气污染以PM_2.5平均浓度（基于卫星遥感数据进行估计）进行描述,室内空气污染通过燃料和烟囱使用情况进行描述,采用两水平（个体层面和社区层面）线性模型分析室内、外空气污染与中国≥50岁人群手握力的关系。结果 共纳入13 175名≥50岁中老年人。手握力为（26.67±0.54）kg。调整性别、年龄、居住地区、文化程度、家庭经济水平、水果蔬菜摄入状况、吸烟、饮酒和体力活动后,室外PM_2.5浓度与手握力呈负相关（β=-0.23,95% CI：-0.31～-0.14）。在农村,相比使用固体燃料（非清洁）,使用清洁燃料可以提高手握力值（β=1.41,95% CI：0.36～2.46）。但在城市地区,未发现使用清洁燃料对手握力值有显著影响（β=0.19,95% CI：-0.95～1.32）。结论 室外PM_2.5与室内污染合并暴露与≥50岁人群低手握力显著相关,提示了慢性长期空气污染暴露有可能是我国中老年人较低机体功能的重要危险因素之一。     

重症监护病房院内下呼吸道感染病原菌及其药敏试验结果分析

目的：探讨重症监护病房（ICU）住院患下呼吸道感染的病原学特点及防治策略。指导临床应用抗生素。方法：对ICU院内肺部感染患深部普进行培养并做药敏试验。结果：221例呼吸道感染患痰培养出病原菌268株，其中革兰氏阴性（G^-）杆菌178株，占66．42％；革兰氏阳性（G^ )球菌5株，占20．29％，真菌36株，占13．43％。药敏试验表明所有细菌均对二种以上的抗生素耐药，未发现对万古霉素耐药的金葡菌。结论：ICU院内肺部感染的致病菌以G^-杆菌为主，铜绿假单胞菌仍是首要致菌；ICU内真菌感染比较严重，ICU内获得性肺部感染不仅数量增加而且细菌耐药性增强，了解本单位病原菌种类及耐药性的变化，合理使用抗生素是降低危重病患院内肺部感染发病率和病死率的重要措施。     

低氧预处理人脐带间充质干细胞治疗早发性卵巢功能不全小鼠的效果研究

目的 探索人脐带间充质干细胞（human umbilical cord mesenchymal stem cells,hUCMSCs）及其经低氧预处理后对早发性卵巢功能不全（premature ovarian insufficiency,POI）小鼠的治疗作用。方法 从脐带中分离、培养出hUCMSCs,利用白消安和环磷酰胺诱导形成小鼠POI模型,分别使用正常hUCMSCs和经低氧预处理的hUCMSCs对POI小鼠进行治疗。实验结束时,测量各组（n=15）小鼠血浆中雌二醇（estradiol,E2）、卵泡刺激素（follicle stimulating hormone,FSH）及抗苗勒管激素（anti Mullerian hormone,AMH）浓度,对卵巢进行组织病理学检查,计数卵泡数量。结果 经过hUCMSCs和低氧预处理hUCMSCs治疗的小鼠血浆E2及AMH浓度,与模型对照组比较,呈升高趋势;且AMH浓度差异有统计学意义（P<0.05）;与模型对照组比较,hUCMSCs和低氧预处理hUCMSCs治疗组小鼠卵巢组织中生长卵泡明显增多、闭锁卵泡明显减少（P<0.05）;卵巢颜色红润,尺寸增大,几乎没有坏死点,卵泡大、透明度好,整体来看与正常对照组卵巢状态相似;且经低氧预处理hUCMSCs治疗的小鼠,其生长卵泡和闭锁卵泡数量更趋于正常。结论 hUCMSCs移植及hUCMSCs低氧预处理后移植治疗均能够有效恢复POI小鼠的激素浓度,促进卵巢功能的恢复。     

颈椎及颈髓损伤(附158例总结)

1970年至1987年,我院收治158例颈椎及颈髓损伤的病人,男125例、女33例各年龄组发病率没有显著差异,共损伤189个椎体,72％病人合并颈髓损伤或颈神经根损伤。本文讨论了:伤后24小时以内就诊者可达46.8％,由于 X 线片显示阴性和并发损伤给早期定位诊断带来一定困难;颈髓损伤的死亡率高达23.5％,在颈椎各种损伤中颈椎脱位是引起颈髓或颈神经根损伤的主要原因,颈推损伤后不宜主观的行屈曲位或后伸位颅骨牵引,而应顺从伤后颈屈度椎平行牵引;颈髓完全性损伤,手术效果不佳,而部分性颈髓损伤的病例,尽早手术治疗,可明显提高治愈率。     

肝郁脾虚证患者尿MHPG-SO_4测定及其临床意义探讨

对肝郁脾虚证、脾虚证、肝郁证患者及健康人进行尿MHPG-SO_4测定,结果肝郁脾虚证组、肝郁证组低于健康人组;并就尿MHPG-SO_4测定意义进行了讨论。     

参芪扶正注射液联合化疗治疗胃癌疗效观察

目的：探讨参芪扶正注射液联合化疗在治疗胃癌中的作用、方法：将82例胃癌术后病人随机分成拳芪扶正注射液联合化疗组和单纯化疗组。单纯化疗组：采用奥沙利铂（L—OHP）、亚叶酸钙（CF）、5-氟尿嘧啶（5-Fu）三药方案：联合治疗组：在使用上方案化疗的同时加用参芪扶正注射液250mL静脉滴注,化疗前3天开始每天1次,连用10天,21天为1个周期,2个周期为1个疗程。观察对比两组的临床症状、KPS评分变化、体重变化情况和副反应结果：①两组临床症状改变有效率分别为61．9％和17.5％,差异有统计学意义（P＜0.01）;②联合治疗组治疗前后KPS评分改善加稳定的比率明显高于单纯化疗组（P＜0．01）;③联合治疗组体重稳定比率明显高于化疗组,且胃肠道反应和骨髓抑制率低于单纯化疗组。     

Mechanisms of dysregulation of low-density lipoprotein receptor expression in HepG2 cells induced by inflammatory cytokines

Background Low-density lipoprotein (LDL) receptor is normally regulated via a feedback system that is dependent on intracellular cholesterol levels. We have demonstrated that cytokines disrupt cholesterol-mediated LDL receptor feedback regulation causing intracellular accumulation of unmodified LDL in peripheral cells. Liver is the central organ for lipid homeostasis. The aim of this study was to investigate the regulation of cholesterol exogenous uptake via LDL receptor and its underlying mechanisms in human hepatic cell line (HepG2) cells under physiological and inflammatory conditions. Methods Intracellular total cholesterol (TC), free cholesterol (FC) and cholesterol ester (CE) were measured by an enzymic assay. Oil Red O staining was used to visualize lipid droplet accumulation in cells. Total cellular RNA was isolated from cells for detecting LDL receptor, sterol regulatory element binding protein (SREBP)-2 and SREBP cleavage-activating protein (SCAP) mRNA levels using real-time quantitative PCR. LDL receptor and SREBP-2 protein expression were examined by Western blotting. Confocal microscopy was used to investigate the translocation of SCAP-SREBP complex from the endoplasmic reticulum (ER) to the Golgi by dual staining with anti-human SCAP and anti-Golgin antibodies.Results LDL loading increased intracellular cholesterol level, thereby reduced LDL receptor mRNA and protein expression in HepG2 cells under physiological conditions. However, interleukin 1β (IL-1β) further increased intracellular cholesterol level in the presence of LDL by increasing both LDL receptor mRNA and protein expression in HepG2. LDL also reduced the SREBP and SCAP mRNA level under physiological conditions. Exposure to IL-1β caused over-expression of SREBP-2 and also disrupted normal distribution of SCAP-SREBP complex in HepG2 by enhancing translocation of SCAP-SREBP from the ER to the Golgi despite a high concentration of LDL in the culture medium.Conclusions IL-1β disrupts cholesterol-mediated LDL receptor feedback regulation by enhancing SCAP-SREBP complex translocation from the ER to the Golgi, thereby increasing SREBP-2 mediated LDL receptor expression even in the presence of high concentration of LDL. This results in LDL cholesterol accumulation in hepatic cells via LDL receptor pathway under inflammatory stress.     

Surgery and Staging of Pancreatic Neuroendocrine Tumors: A 14-Year Experience

Background  

The aims of this study were to evaluate contemporary outcomes associated with the surgical management of pancreatic neuroendocrine tumors (PNETs) and to assess the prognostic value of the World Health Organization (WHO) classification and TNM staging for PNETs.     

A Dipole with Reflector-Backed Active Metasurface for Linear-to-Circular Polarization Reconfigurability

In recent years, significant advances have been made in diversifying the capabilities of communication systems by using reconfigurable antennas. There are many types of reconfigurable antennas—to achieve pattern, frequency, or polarization reconfigurability. These antennas are reconfigured either by the mechanical rotation of surfaces or by enabling or disabling specific sections of the structure using electrical switches. This paper focuses on the concept of a polarization reconfigurable antenna based on an active reflector-backed metasurface. An antenna system based on an active reflector-backed metasurface combined with a planar dipole is designed to achieve reconfigurable polarization. The polarization of the designed antenna can be switched between linear and circular polarization states using positive-intrinsic-negative diodes located in the unit cell elements of the metasurface. The measured results correlate well with the simulated results. The antenna has a physical size of 308 × 162 × 35 mm³ with an impedance bandwidth of 4.5% in the linear state and 7% in the circular state, as well as an axial ratio bandwidth larger than 8.3%.