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目的评价根管封闭剂iRootSP的根尖封闭效果。方法选择2012年9—12月中国医科大学口腔医学院口腔外科拔除的单根管前牙50颗,随机分为2个实验组（A、B组,每组20颗）和2个对照组（c组为阳性对照组,D组为阴性对照组,每组5颗）。所有牙均常规开髓、拔髓,采用机用ProTaper设备根管至F2。A、B组分别采用根管封闭剂iRootSP加单尖充填技术和根管封闭剂AHPlus加单尖充填技术充填根管,c、D组均不做任何根管充填;4组牙齿均用光固化复合树脂充填髓腔及开髓孔。A、B、c组在除根尖孔2mm外的整个牙根表面均匀涂布指甲油2遍,D组在牙根表面及根尖孔全部涂布指甲油2遍。采用染料渗透法检测根尖微渗漏情况,对各组染料渗透长度进行比较分析。结果A、B组均有不同程度的根尖微渗漏,A组染料渗透长度为（1．62±0．20）mm,B组为（1．80±0．20）mm,两组间差异无统计学意义（P〉0．05）。作为阳性对照的c组,染料渗透长度为（10．75±1．28）mm,几乎渗入牙根全长;作为阴性对照的D组,则无染料渗入牙根。结论根管封闭剂iRootSP的根尖封闭性能与AHPlus相似。由于单尖充填技术操作简便,副损伤小,省时省力,具有良好的临床应用前景。     

异黏蛋白及波形蛋白在食管鳞状细胞癌组织中的表达及其预后的关系

目的分析食管鳞状细胞癌(ESCC)患者异黏蛋白(MTDH)的表达水平,分析与上皮-间质转化(EMT)有关联的指标波形蛋白(Vimentin)的表达水平与ESCC预后的关系。方法采用组织芯片进行免疫组织化学染色,芯片中包含75对食管鳞癌癌组织标本,另含有与食管癌组织相对应的配对癌旁正常食管组织,以距离病灶3 cm为标准,另有30例食管癌组织为不成对的食管癌组织,所有食管癌组织和正常食管组织均来源于组织芯片。采用免疫组织化学SP法分别检测MTDH、Vimentin的表达情况,并且分析MTDH、Vimentin的表达与ESCC临床病理的关系,采用Kaplan-Meier法对MTDH与Vimentin不同表达水平的患者术后生存率的差异进行比较。用Spearman相关性分析MTDH与Vimentin表达水平之间的关系。结果在食管癌细胞中,MTDH的表达明显增多,正常食管上皮细胞中也有少量表达。阳性细胞大部分在胞质表达,在细胞核也有少量的表达,MTDH的阳性表达主要呈浅黄、棕黄色或褐色颗粒。经统计学分析后,MTDH在食管癌组织中的阳性表达率要明显高于配对癌旁正常食管上皮组织中的阳性表达率,差异有统计学意义(P<0.05)。MTDH的表达与临床病理参数关系显示,MTDH在食管癌中的表达与N分期(P=0.016)有关,具体体现在N 1~N 3分期MTDH阳性表达率明显高于N 0分期的患者。Vimentin在食管癌细胞中的表达较多,同时也可表达于少量正常食管上皮细胞,阳性细胞主要为胞质表达,呈褐色、棕黄色或浅黄颗粒。Vimentin在食管癌组织中的表达要明显高于配对癌旁正常食管组织,差异有统计学意义(P<0.05)。另外通过统计Vimentin与食管癌病理特征的关系显示,Vimentin在食管癌组织中的表达与T分期(P=0.019)及肿瘤的体积(P=0.040)有关。Kaplan-Meier法分析显示,MTDH高表达的患者生存时间越短,差异有统计学意义(P<0.05),而高表达Vimentin患者和低表达Vimentin患者二者生存率比较,差异无统计学意义(P>0.05)。Spearman相关性分析结果显示,MTDH与Vimentin在ESCC组织中表达水平呈正相关(r=0.218,P=0.019)。结论MTDH和Vimentin的表达增加可能与食管癌的发生、发展及肿瘤细胞浸润转移密切相关。MTDH对食管癌术后患者判断预后,可能有一定的作用。     

Microstructure and Texture Evolution during Superplastic Deformation of SP700 Titanium Alloy

The superplastic tensile test was carried out on SP700 (Ti-4.5Al-3V-2Mo-2Fe) titanium alloy sheet at 760 °C by the method of maximum m value, and the microstructure characteristics were investigated to understand the deformation mechanism. The results indicated that the examined alloy showed an extremely fine grain size of ~1.3 μm and an excellent superplasticity with fracture elongation of up to 3000%. The grain size and the volume fraction of the β phase increased as the strain increased, accompanied by the elements’ diffusion. The β-stabilizing elements (Mo, Fe, and V) were mainly dissolved within the β phase and diffused from α to β phase furthermore during deformation. The increase in strain leads to the accumulation of dislocations, which results in the increase in the proportion of low angle grain boundaries by 15%. As the deformation process, the crystal of α grains rotated, and the texture changed, accompanied by the accumulation of dislocations. The phase boundary (α/β) sliding accommodated by dislocation slip was the predominant mechanism for SP700 alloy during superplastic deformation.     

Young convalescent COVID‐19 pneumonia with extensive pneumomediastinum emphysema: Case report

The development of the SARS‐CoV‐2 pandemic caused a common appearance of severe pulmonary complications, rarely seen as a result of the other infections. These are pneumothorax, pneumomediastinum, emphysematous bullae, cavitary lung lesions, or subcutaneous emphysema. Their formation is influenced by both—the natural course of the disease and the treatment strategy adopted.     

Analgesic effects and hemodynamic mechanisms of perpendicular and transverse needling at Sanyinjiao (SP 6) in patients with primary dysmenorrhea: A randomized controlled trial

ObjectiveTo explore the analgesic effects and uterine hemodynamics of perpendicular needling (PN) and transverse needling (TN) at SP 6 in patients with primary dysmenorrhea (PD).MethodsIn this randomized controlled trial, patients with PD diagnosed with cold-dampness congealing pattern were randomly assigned in a ratio of 1:1 to receive PN or TN at bilateral SP 6 for 10 min. Acupuncture was performed when the menstrual pain score was over 40 mm on the first day of menstruation, as measured using the visual analog scale for pain (VAS-P). The primary outcome was average menstrual pain (VAS-P). Secondary outcomes included the pulsatility index (PI), resistance index (RI), and systolic-diastolic peaks ratio (S/D) in uterine arteries as measured using color Doppler ultrasonography; anxiety as assessed using the Hamilton Anxiety Rating Scale (HAMA), blood pressure (BP), and heart rate (HR).ResultsForty-eight patients completed the study. The TN group exhibited a significant reduction in VAS-P scores (–5.71 mm, 95% confidence interval (CI): –8.78, –2.63, P = .001), RI values (–0.05, 95% CI: –0.09, –0.01, P = .015), and HAMA values (–2.50, 95% CI: –4.78, –0.22, P = .032) when compared with the PN group. No significant differences in PI, S/D, BP, or HR values were observed between the two groups (P > .05).ConclusionTN at SP 6 was superior to PN in alleviating menstrual pain and anxiety in patients with PD. This analgesic effect of TN may be due to its better ability to improve uterine arterial blood flow via decreases in RI values.     

肿瘤干细胞的研究进展

肿瘤具有异质性的特征,随着研究的深入,越来越多的证据提示肿瘤组织中也存在少量具有干细胞性质的肿瘤干细胞,于是人们在此基础上提出了肿瘤干细胞学说,肿瘤干细胞已成为当今肿瘤研究领域的热点。目前,已经从白血病、脑肿瘤、乳腺癌、恶性黑色素瘤及前列腺癌等多种恶性肿瘤中初步分离鉴定出肿瘤干细胞。肿瘤干细胞学说的提出,使得靶向性杀伤肿瘤干细胞从而根治肿瘤成为可能。     

细粒棘球蚴2HSP70重组质粒的构建、原核表达、纯化和初步鉴定

目的构建细粒棘球蚴（Echinococcus granulosus，EG）2热休克蛋白70（heat shock protein，2HSPT0）表达重组质粒，原核表达及纯化重组蛋白，并对重组蛋白进行免疫学特性的初步鉴定。方法从EG2HSP70／pGEM-T／JM109质粒中分离EG2HSP70目的基因，将此片段重组入表达载体pGEX-6P-1后转化入大肠杆菌BL21，鉴定后以IPTG诱导表达，通过SDS-PAGE检测其表达水平，用亲和层析纯化并分离重组蛋白，利用Western blot来鉴定重组蛋白的免疫学特性。结果酶切鉴定及测序分析表明，成功构建细粒棘球蚴pGEX-6P-1／EG2HSP70重组质粒；IPTG诱导表达后，融合蛋白占菌体总蛋白的39％，占裂解物上清总蛋白的70．4%，表明重组的EG2HSP70基因能在BL21中高效表达，表达的蛋白大部分以可溶性状态存在。亲和层析法纯化重组蛋白EG2HSP70，通过Western blot证实该重组蛋白能被细粒棘球蚴囊壁免疫兔血清识别。结论成功构建细粒棘球蚴中国大陆株pGEX-6P-1／EG2HSP70重组质粒，重组的EG2HSP70能够高效表达，表达的EG2HSP70具有免疫学活性。     

儿食健宝颗粒对幼龄厌食大鼠模型空肠段SP、VIP、SS表达影响的实验研究

目的:从胃肠激素水平探讨健脾中药儿食儿食健宝颗粒治疗小儿厌食症的作用机制。方法:用饮食不当法复制幼龄厌食症大鼠模型,通过观察肠内P物质(SP)、血管活性肠肽(VIP)、生长抑制素(SS)水平的变化,以及胃肠病理形态学改变,观察儿食健宝颗粒的作用。结果:儿食健宝颗粒可以改善厌食症大鼠SP、VIP、SS水平变化及胃肠粘膜病理形态。结论:儿食健宝颗粒可改善厌食症大鼠胃肠黏膜的病理形态学改变,并对SP、VIP、SS具有调节与平衡作用。     

lncRNA NEAT1通过调节miR-27b-3p/SP1轴对心房颤动大鼠心肌纤维化的影响

目的]探讨lncRNA NEAT1通过调节miR-27b-3p/特异性蛋白1(SP1)轴对心房颤动(AF)大鼠心肌纤维化的影响。 [方法]54只大鼠按照随机数字表法分成6组(n＝9):假手术组、AF组、AF＋shControl组、AF＋shNEAT1组、AF＋shNEAT1＋anti-miR-Control组、AF＋shNEAT1＋anti-miR-27b-3p组。转染上述慢病毒载体2周后,采用连续7天尾静脉注射乙酰胆碱-氯化钙的方法进行AF大鼠造模。AF的发生率、持续时间采用心电图记录;RT-qPCR检测心房组织内NEAT1、miR-27b-3p、SP1及纤维化相关基因(TGF-β1、CTGF、COLⅠ、COLⅢ)的表达水平;荧光素酶报告基因检测miR-27b-3p与NEAT1、miR-27b-3p与SP1的靶向关系;TUNEL染色观察心房组织心肌细胞凋亡;Masson染色观察心房组织心肌纤维化;Western blot检测心房组织中SP1、纤维化相关基因的蛋白表达水平。 [结果]与AF组比较,AF＋shNEAT1组AF的发生率和持续时间降低,心肌纤维化和细胞凋亡减轻,TGF-β1、CTGF、COLⅠ、COLⅢ的mRNA和蛋白表达降低(P＜0.05)。NEAT1负调控miR-27b-3p水平。沉默miR-27b-3p可逆转shNEAT1对AF大鼠心肌细胞凋亡和心肌纤维化的抑制作用。miR-27b-3p直接靶向SP1并抑制其mRNA和蛋白表达(P＜0.05)。NEAT1通过下调miR-27b-3p促进SP1的表达。 [结论]NEAT1下调可缓解AF和AF诱导的心肌纤维化,其调控机制与调节miR-27b-3p/SP1轴有关。