Entrainment of circus movement tachycardia utilizing an accessory pathway with long retrograde conduction times during ventricular and atrial stimulation

An unusual case is presented in which a circus movement tachycardia incorporating an accessory pathway with long retrograde conduction time was transiently entrained. Overdrive high right atrial stimulation produced entrainment without atrial fusion since collision of anterograde and retrograde impulses took place within the accessory pathway. Tachycardia termination occurred when, at a faster pacing rate, an atrial impulse that collided in the accessory pathway was blocked at the atrioventricular (AV) node. In contrast, the entrainment seen during right ventricular apical stimulation was characterized by the occurrence of both fusion and collision within the ventricles. The tachycardia was terminated when a pure paced impulse that collided in the normal pathway was blocked in a retrograde direction in the accessory pathway. These data indicate that: 1) transient entrainment of this arrhythmia (circus movement tachycardia) can be identified by the classical criteria used to diagnose it, provided that fusion and collision occur within the ventricles; and 2) the accessory pathway is the weak link for tachycardia termination only during ventricular pacing since the AV node is the weak link during atrial stimulation.     

As2O3诱导HL-60,K562及NB4细胞的凋亡

目的 :研究三氧化二砷 (As2 O3)对慢性粒细胞K5 6 2 (CML) ,急性粒细胞白血病细胞株HL - 6 0 (AMLM2 )的作用并与细胞株NB4(APLM3)作比较。方法 :采用形态学和流式细胞术观察不同浓度As2 O3 对HL - 6 0 ,K5 6 2及NB4细胞的作用。结果 :As2 O3不仅能诱导NB4的凋亡 ,提高其浓度至 2 .7μM和 8.1μM ,也能诱导K5 6 2 ,HL - 6 0的凋亡。As2 O3 不能诱导三种细胞分化。结论 :As2 O3 对细胞诱导的凋亡是非选择性的且不能诱导分化。     

Effects of movement imitation training in Parkinson's disease: A virtual reality pilot study

BackgroundHypometria is a clinical motor sign in Parkinson's disease. Its origin likely emerges from basal ganglia dysfunction, leading to an impaired control of inhibitory intracortical motor circuits. Some neurorehabilitation approaches include movement imitation training; besides the effects of motor practice, there might be a benefit due to observation and imitation of un-altered movement patterns. In this sense, virtual reality facilitates the process by customizing motor-patterns to be observed and imitated.ObjectiveTo evaluate the effect of a motor-imitation therapy focused on hypometria in Parkinson's disease using virtual reality.MethodsWe carried out a randomized controlled pilot-study. Sixteen patients were randomly assigned in experimental and control groups. Groups underwent 4-weeks of training based on finger-tapping with the dominant hand, in which imitation was the differential factor (only the experimental group imitated). We evaluated self-paced movement features and cortico-spinal excitability (recruitment curves and silent periods in both hemispheres) before, immediately after, and two weeks after the training period.ResultsMovement amplitude increased significantly after the therapy in the experimental group for the trained and un-trained hands. Motor thresholds and silent periods evaluated with transcranial magnetic stimulation were differently modified by training in the two groups; although the changes in the input–output recruitment were similar.ConclusionsThis pilot study suggests that movement imitation therapy enhances the effect of motor practice in patients with Parkinson's disease; imitation-training might be helpful for reducing hypometria in these patients. These results must be clarified in future larger trials.     

四氧化三铁微粒与碘化油混悬液栓塞兔肾动脉的实验研究

目的　探讨四氧化三铁(Fe3O4)微粒与碘化油(Lp)混悬液(suspension from magnetic microspheres with lipi odol, S Fe3O4 Lp)对兔肾动脉的栓塞和导向作用机制。方法　测定工业工艺制备粒径为 50~250μm 5 种规格的 Fe3O4微粒在Lp中的沉降时间、速度;实验组用粒径250μm的S Fe3O4 Lp对右肾动脉栓塞,对照组用Lp栓塞。两组于术后不同时间比较栓塞效果、观察血生化和病理学改变。结果　五种粒度的Fe3O4 微粒能在一定时间范围内悬浮于Lp中;栓塞效果实验组优于对照组;实验组栓塞部位Fe3O4 微粒与Lp存留存在明显正相关关系(P<0.005,r=0.76)。结论　粒径为250μm的S Fe3O4 Lp对兔肾动脉栓塞效果好,无明显毒副反应;栓塞过程中Fe3O4 微粒与Lp具有同步、同向性,是S Fe3O4 Lp发挥导向性栓塞的基础。     

Redefining “low risk”: Outcomes of surgical aortic valve replacement in low-risk patients in the transcatheter aortic valve replacement era

ObjectivesGuidelines suggest aortic valve replacement (AVR) for low-risk asymptomatic patients. Indications for transcatheter AVR now include low-risk patients, making it imperative to understand state-of-the-art surgical AVR (SAVR) in this population. Therefore, we compared SAVR outcomes in low-risk patients with those expected from Society of Thoracic Surgeons (STS) models and assessed their intermediate-term survival.MethodsFrom January 2005 to January 2017, 3493 isolated SAVRs were performed in 3474 patients with STS predicted risk of mortality <4%. Observed operative mortality and composite major morbidity or mortality were compared with STS-expected outcomes according to calendar year of surgery. Logistic regression analysis was used to identify risk factors for these outcomes. Patients were followed for time-related mortality.ResultsWith 15 observed operative deaths (0.43%) compared with 55 expected (1.6%), the observed:expected ratio was 0.27 for mortality (95% confidence interval [CI], 0.14-0.42), stroke 0.65 (95% CI, 0.41-0.89), and reoperation 0.50 (95% CI, 0.42-0.60). Major morbidity or mortality steadily declined, with probabilities of 8.6%, 6.7%, and 5.2% in 2006, 2011, and 2016, respectively, while STS-expected risk remained at approximately 12%. Mitral valve regurgitation, ventricular hypertrophy, pulmonary, renal, and hepatic failure, coronary artery disease, and earlier surgery date were residual risk factors. Survival was 98%, 91%, and 82% at 1, 5, and 9 years, respectively, superior to that predicted for the US age-race-sex–matched population.ConclusionsSTS risk models overestimate contemporary SAVR risk at a high-volume center, supporting efforts to create a more agile quality assessment program. SAVR in low-risk patients provides durable survival benefit, supporting early surgery and providing a benchmark for transcatheter AVR.     

虎杖苷促进大鼠骨质疏松性骨折的作用及对SIRT1/FoxO1信号通路的影响

目的 探究虎杖苷对骨质疏松性骨折大鼠骨折愈合的效果及对沉默信息调节因子1（SIRT1）/叉头状转录因子O1（FoxO1）信号通路的影响。方法 构建骨质疏松性骨折大鼠模型,将建模成功的48只大鼠随机分为模型组、虎杖苷低剂量（30 mg/kg）组、虎杖苷高剂量（60 mg/kg）组、阿仑膦酸钠组（0.5 mg/kg）。另取12只大鼠作为对照组,构建相同部位骨折模型。建模结束后,各组大鼠给予相应药物灌胃,每天1次,连续8周。对大鼠进行骨折愈合程度评分并检测骨折处骨密度（bone mineral density, BMD）;运用酶联免疫吸附法检测大鼠血清中I型胶原交联羧基末端肽（CTX-Ⅰ）、骨钙素（OC）、肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）水平;通过苏木素-伊红染色观察大鼠骨组织病理学;通过荧光定量PCR法检测大鼠骨组织中SIRT1、FoxO1信使RNA（mRNA）水平;通过蛋白印迹法检测大鼠骨组织中SIRT1、FoxO1蛋白水平。结果 与模型组相比,虎杖苷低、高剂量组大鼠骨组织病理学变化程度依次减轻,骨折愈合程度评分、骨折处BMD、血清中OC、骨组织中SIRT1、FoxO1 mRNA和蛋白水平依次升高,CTX-Ⅰ、TNF-α、IL-1β水平依次降低（P<0.05）;阿仑膦酸钠组和虎杖苷高剂量组大鼠骨组织病理学变化及各项指标比较均无显著差异（P>0.05）。结论 虎杖苷可减轻骨质疏松性骨折大鼠炎症反应,提升BMD,促进骨折愈合,其机制可能与激活SIRT1/FoxO1信号通路有关。     

基于上转发光免疫层析技术的常见食源性致病菌快速检测方法研究与评价

目的：研制针对4种常见食源性致病菌：甲型副伤寒沙门菌（ Salmonella paratyphi A）、乙型副伤寒沙门菌（Salmonella paratyphi B）、大肠埃希菌O157∶H7（Escherichia coli O157∶H7）、副溶血弧菌（Vibrio parahaemolyticus）的基于上转发光免疫层析技术（ UPT－LF）的快速定量检测试纸,并对其检测性能进行评价。方法以上转发光纳米颗粒（ UCP－NPs）作为示踪物,基于双抗体夹心检测模型,研制针对上述4种靶标菌的UPT－LF试纸;以4种靶标菌的系列浓度标准菌悬液作为标准样品,评价试纸的敏感性、特异性、线性和精密性,并进行模拟染菌食品的检测,评价模拟样品阳性检出率。结果针对4种靶标菌的UPT－LF试纸均具有良好的线性,相关系数r为0．985～0．996;检测敏感性达105～106 CFU／ml,与其他近缘菌株无交叉反应;对乳制品、饮料、小食品、水产、肉类等细菌污染的食品检出率较高。结论该研究建立的对4种常见食源性致病菌进行快速检测的UPT－LF,简便快速,具有良好的敏感性、特异性和线性定量能力,操作性能可满足食品安全检测的要求。     

Faster pulmonary oxygen uptake kinetics in children vs adults due to enhancements in oxygen delivery and extraction

This study aimed to examine if the faster pulmonary oxygen uptake (VO_2p) phase 2 in children could be explained by increased O ₂ availability or extraction at the muscle level. For that purpose, O ₂ availability and extraction were assessed using deoxyhemoglobin (HHb) estimated by near‐infrared spectroscopy during moderate‐intensity constant load cycling exercise in children and young adults. Eleven prepubertal boys and 12 men volunteered to participate in the study. They performed one maximal graded exercise to determine the power associated with the gas exchange threshold (GET) and four constant load exercises at 90% of GET. VO_2p and HHb were continuously monitored. VO_2p, HHb, and estimated capillary blood flow () kinetics were modelled after a time delay and characterized by the time to achieve 63% of the amplitude (τ) and by mean response time (MRT: time delay + τ), respectively. Mean values of τ for VO_2p (P < 0.001), of MRT for HHb (P < 0.01) and of MRT for (P < 0.001) were significantly shorter in children. Faster VO_2p kinetics have been shown in children; these appear due to both faster O ₂ extraction and delivery kinetics as indicated by faster HHb and kinetics, respectively.     

CT导向下经皮臭氧注射腰椎间盘溶解术的临床研究

目的：研究CT引导下臭氧注射腰椎间盘溶解术治疗腰椎间盘突出症的价值。方法：136例腰椎间盘突出症患者,经CT或MRI证实,保守治疗3月以上无效。手术在严格的无菌条件下进行。局麻,CT导向下用18 G穿刺针穿刺病变椎间盘并注射浓度为50μg/ml的臭氧气体20 ml,必要时在退针至椎间孔附近时,向椎旁组织内注入臭氧10 ml。依据Mac-Nab腰腿痛手术评价标准评价治疗效果。分析患者年龄、病程、突出程度、是否累及多个椎间盘等相关因素对疗效的影响。结果：136例患者随访3～24月,显效56例（41.2%）,有效69例（50.7%）,无效11例（8%）,总有效率近92%。术后无1例并发症。结论：CT引导下经皮臭氧注射腰椎间盘溶解术是治疗腰椎间盘突出症的一种安全有效的微创方法。