药物致尖端扭转型室性心动过速的发生机制

目的探讨药物致尖端扭转型室性心动过速(Tdp)的发生机制。方法建立冠状动脉灌注的犬左室心肌楔形组织块模型,同步记录左心室内膜、中层、外膜心肌细胞的动作电位及跨壁心电图,观察不同浓度D-Sotalol对动作电位时间(APD)、QT间期、跨壁复极离散度(TDR)、早期后除极(EAD)及Tdp发生的影响。结果浓度为0～100μmol/L的D-Sotalol呈剂量依赖性地延长各层细胞APD,尤以中层细胞最为显著(P<0.05),因而增加TDR;D-Sotalol在中层细胞可诱发EAD,触发室性早博并形成跨壁折返导致Tdp。结论 D-Sotalol在中层细胞诱发EAD、R on T室性早博是其致Tdp的始动因子,在TDR增加的基础上形成跨室壁折返是Tdp得以维持的关键。     

MicroRNA-218在肝细胞癌中的表达及功能

目的检测MicroRNA-218(miR-218)在肝细胞癌中的表达情况并研究其在肝癌中的功能。方法收集46例肝细胞癌及对应癌旁组织,运用qRT-PCR技术检测miR-218在肝癌及对应癌旁组织中的表达情况;应用miR-218 mimic转染人肝癌细胞系HepG2,MTT和流式细胞术检测转染后细胞活力和凋亡变化,qRT-PCR和Western blot检测miR-218潜在靶点的表达变化。结果 miR-218在肝癌组织中的表达显著低于对应的癌旁组织(P<0.05);miR-218低表达与肿瘤大小(>5 cm)和高TNM分期(Ⅲ+Ⅳ)具有显著相关性(P<0.05);在HepG2细胞中,miR-218抑制细胞增殖和诱导凋亡,并下调Bmi-1和CDK6 mRNA及蛋白表达(P<0.05)。结论 miR-218低表达与肝癌的恶性临床病理特征相关,miR-218可能通过下调Bmi-1和CDK6表达抑制肝癌细胞增殖和促进凋亡。     

莫西沙星与左氧氟沙星对耐药性肺结核患者的疗效及痰菌定植的影响

目的研究莫西沙星与左氧氟沙星对耐药性肺结核患者的疗效及痰菌定植的影响。方法选择2012年6月～2014年5月经痰结核分枝杆菌药物敏感试验确定为耐药性肺结核的住院患者92例实施研究,根据数字法随机分成观察组(应用莫西沙星治疗)及对照组(应用左氧氟沙星治疗)各46例,治疗12个月后对比两组治疗后的整体疗效,在治疗不同时期(1,3,6及12个月)收集患者痰标本进行涂片抗酸染色获得痰菌定植转阴率,观察治疗后的病灶及空洞变化,以及两组药物不良反应。结果治疗满12个月观察组痰涂片阴性44例,阳性2例,阴转率95.65% ,对照组痰涂片阴性38例,阳性8例,阴转率82.61%;观察组治疗1个月～12个月的痰菌定植转阴率均分别显著高于对照组,差异均有统计学意义(χ2=4.449,4.423,6.571,4.039;均P＜0.05);观察组的显效率是58.70%,总有效率是97.83%,均显著高于对照组的36.96%及80.43%,差异有统计学意义(χ2=4.356,7.180;均P＜0.05)。两组治疗后的病灶及空洞变化对比,差异无统计学意义(χ2=0.337,0.211,0.746,0.123;均P＞0.05)。观察组的总不良反应发生率为26.09%,与对照组的32.61%相比,差异无统计学意义(χ2=0.472;P＞0.05)。结论莫西沙星治疗耐药性肺结核患者具有较好的疗效,且能有效改善痰菌定植的状况,安全性较高,值得推荐。     

The ventilatory and metabolic response to hypercapnia in newborn mammalian species

Conscious newborns of 12 species from 4 mammalian orders, ranging in body mass (M) from 1 g (mouse) to 5 kg (deer), were studied during air and during 5% CO₂ breathing. The interspecies relationship between oxygen consumption (V̇_O2) and M was the same in air and hypercapnia, in both cases V̇_O2 ∝ M^0.90; on average, hypercapnic V̇_O2 was 101% of the air value. In 5% CO₂, ventilation (V̇e) increased in all newborns, mostly because of the increase in tidal volume (178%), whereas breathing rates averaged 98% of the air values. The hyperpnea during CO₂ was slightly greater in the larger newborns. Body temperature was not altered by CO₂ breathing. We conclude that the average respiratory response of the newborn to moderate hypercapnia is a hyperventilation different from that of the neonatal mammal in acute hypoxia (Mortola et al., Respir. Physiol. 78: 31–43, 1989). In fact, hypercapnic hyperventilation resulted only from the hyperpnea, with no hypometabolic contribution, and the hyperpnea reflected the increase in tidal volume, with no change in rate. It is also concluded that the neonatal hypometabolic response is specific to hypoxia, and not an undifferentiated response to chemoreceptors stimulation.     

Prohibitin 表达及对乳腺癌细胞系MCF-7 抑制生长的机制研究

目的　该研究从细胞水平研究了抗增殖蛋白（prohibitin）高表达在乳腺癌细胞中的生物学功能,并研究其抑制 MCF-7 生长的分子机制。方法　使用基因重组法构建pEGFP-PHB 重组质粒,脂质体瞬时转染乳腺癌细胞系MCF-7, real time-PCR 和Western Blotting 验证其高表达后,检测细胞生物学功能。包括:MTT（噻唑蓝）法检测细胞生长、流 式细胞仪检测细胞周期与凋亡、肿瘤相关基因P53, Bcl-2, ERBB2 及E2F-1 的检测和Transwell 小室侵袭实验。两样本差 异比较采用t 检验,多样本差异采用单因素方差分析。结果　MTT 显示PHB 高表达组在转染24, 48 和72h 对细胞生长 的抑制率分别为20.98%, 14.93% 和62.94%,差异有统计学意义;流式细胞仪检测细胞分裂周期,phb 高表达G1 期无差异, S 期降低,G2 期增加;凋亡检测中,高表达组细胞总凋亡率为33.67%±8.68%,阴性对照组的凋亡率12.13%±3.76%, 空白对照组凋亡率为6.99%±2.33%,高表达组细胞凋亡率高于对照组,差异有统计学意义（F=18.992, P=0.003）; PHB 高表达时,肿瘤相关蛋白P53 和ERBB2 的表达量高于对照组（t=4.590, P=0.044; t=9.489, P=0.011）,Bcl-2 表达降 低,差异有统计学意义(t=7.143, P=0.019),E2F-1 蛋白各组间差异无统计学意义(t=2.175, P=0.162);PHB 高表达组细胞 侵袭能力低于对照组,差异有统计学意义（t=3.221, P=0.01;t=4.057, P=0.003）。结论　PHB 高表达抑制S 期DNA 的合 成,阻滞细胞于G2/M 期,增加细胞凋亡率,抑制肿瘤细胞MCF-7 的生长。其与肿瘤相关蛋白P53 和ERBB2 的增高, Bcl-2 表达的降低紧密相关。     

非瓣膜性房颤防治综合策略中左心耳封堵术的助攻

左心耳封堵术已成为预防非瓣膜性心房颤动患者发生脑卒中的常用器械抗栓方案.随着房颤防治ABC综合策略以及中国房颤分级诊疗方案的出台,左心耳封堵术也将越来越受到重视,并成为房颤患者规范化综合治疗中重要一环.     

CBL教学在心血管外科留学生实习教学中的应用

目的 探讨以病例为引导的教学模式(case-based learning,CBL)在本科留学生心血管外科临床实习中的应用.方法 选择2014级在西安交通大学第一附属医院心血管外科实习的本科留学生20人为研究对象,随机分为对照组(传统教学法,10人)和CBL教学组(10人).对照组以PPT的方式进行讲授,而CBL教学组通...     

血清高尔基体蛋白73诊断原发性肝癌价值探讨

目的探讨高尔基体蛋白73（GP73）诊断肝癌的价值。方法在肝癌107例、肝硬化53例、肝衰竭患者40例和健康人34例,采用ELISA法检测血清GP73浓度,采用ROC曲线寻找GP73诊断肝癌的最佳截断点,并与AFP进行比较,以评价GP73诊断肝癌的价值。结果原发性肝癌、肝硬化和慢性肝衰竭患者血清GP73水平分别为123.5±22.4ng/ml、108.9±30.3ng/ml和130.3±45.6ng/ml,均显著高于健康对照人群（44.1±38.9ng/ml,P〈0.05）;原发性肝癌、肝硬化和慢性肝衰竭患者血清AFP水平分别为236.6±205.3ng/ml、5.3±5.56ng/ml和53.9±40.40 ng/ml;选择血清GP73最佳截断点为77.4ng/ml,其诊断原发性肝癌的灵敏度为89.6%,特异度为100%,AFP的最佳截断点为35.4ng/ml,其诊断原发性肝癌的灵敏度为64.2%,特异度为100%;原发性肝癌患者血清GP73水平在不同年龄、性别、Edmondson分级和结节数目多寡之间无显著性相差,而在不同肿瘤大小、TNM分期和是否合并肝硬化方面均有显著性差异（P＜0.05）。结论血清GP73诊断肝癌的灵敏度优于AFP,尤其在AFP阴性患者诊断中有一定的意义。     

Analysis of risk factors of patients with initial treatment of secondary pulmonary tuberculosis complicated with cervical lymph node tuberculosis

目的 探讨初治继发性肺结核患者治疗过程中并发颈部淋巴结结核的危险因素。方法 收集2018年12月至2020年7月于西安市胸科医院住院确诊的符合纳入标准的357例初治继发性肺结核,其中57例并发颈部淋巴结结核(简称“并发组”); 300例未并发颈部淋巴结结核(简称“未并发组”)。并发组中,年龄中位数(四分位数)[M(Q₁,Q₃)]为30(26,38)岁,其中14~<44岁年龄组有40例,≥44岁年龄组有17例。未并发组中,年龄M(Q₁,Q₃)为39(32,48)岁,其中14~<44岁年龄组有198例,≥44岁年龄组有102例。对患者年龄、性别、口腔黏膜炎、上呼吸道感染、是否使用免疫抑制剂、肺结核患者病程及痰菌检测情况等7项与颈部淋巴结结核发生情况的相关因素进行分析,分别采用单因素分析及多因素logistic回归分析,以P<0.05为差异有统计学意义。结果 357例初治继发性肺结核患者发生颈部淋巴结结核的单因素分析结果显示,未并发组和并发组在上述各因素中,年龄≥44岁者占比分别为34.0%(102/300)、29.8%(17/57);男性占比分别为45.7%(137/300)、40.4%(23/57);发生口腔黏膜炎者占比分别为11.7%(35/300)、45.6%(26/57);发生上呼吸道感染者占比分别为16.3%(49/300)、36.8%(21/57);使用免疫抑制剂者占比分别为8.0%(24/300)、10.5%(6/57);肺结核患病时间>3个月者占比分别为41.0%(123/300)、38.6%(22/57);痰菌阳性者占比分别为19.3%(58/300)、68.4%(39/57)。两组比较,χ²值分别为0.376、0.547、38.963、12.781、0.397、0.115、58.326,P值分别为0.540、0.459、0.000、0.000、0.529、0.735、0.000。多因素logistic回归分析结果显示,发生口腔黏膜炎(Wald χ²=12.279,OR=3.564,95%CI=1.751~7.255,P=0.004)、发生上呼吸道感染(Wald χ²=9.987,OR=3.092,95%CI=1.535~6.227,P=0.002)及痰菌阳性(Wald χ²=26.320,OR=5.880,95%CI=2.989~11.568,P=0.000)是初治继发性肺结核治疗过程中发生颈部淋巴结结核的危险因素。结论 初治继发性肺结核患者在治疗过程中,发生口腔黏膜炎、上呼吸道感染及痰菌阳性的患者易并发颈部淋巴结结核,可作为临床预防的关注因素。     

Topographical distributions of endomorphinergic pathways from nucleus tractus solitarii to periaqueductal gray in the rat

In the central nervous system (CNS), endomorphin 1 (EM1)- and endomorphin 2 (EM2)-containing neuronal cell bodies have been found in the nucleus tractus sollitarii (NTS) and the hypothalamus, and EMergic fibers and terminals are distributed widely in many regions of the CNS, including the periaqueductal gray (PAG). The aim of the present study was to examine whether EM-expressing neurons in the NTS of the rat send their axons to the PAG, and determine whether the EMergic pathway from the NTS to the PAG is topographic by using. Immunofluorescent staining for EM1 or EM2 combined with retrograde and anterograde tract-tracing methods. The results showed that after injecting tetramethyl rhodamine dextran-amine (TMR) into the ventrolateral or lateral column of the PAG, some EM1- or EM2-immunoreactive (IR) neurons in the NTS were retrogradely labeled with TMR, and the majority of the EM-IR/TMR double-labeled neurons were mainly distributed in the medial and commissural subnuclei of the NTS. Following injection of biotinylated dextran amine (BDA) into the medial or commissural subnucleus of the NTS, EM1-IR/BDA and EM2-IR/BDA double-labeled fibers and terminals were mainly distributed in the ventrolateral or lateral column of the PAG, respectively. The results indicate that EMergic pathway from the NTS to PAG is topographically organized, and suggest that EMs released from NTS to PAG projecting terminals may bind to μ-opioid receptor on the PAG neurons, and thereby contribute to various functions.