Wall shear stress effects of different endodontic irrigation techniques and systems

ObjectivesThis study examined débridement efficacy as a result of wall shear stresses created by different irrigant delivery/agitation techniques in an inaccessible recess of a curved root canal model.MethodsA reusable, curved canal cavity containing a simulated canal fin was milled into mirrored titanium blocks. Calcium hydroxide (Ca(OH)₂) paste was used as debris and loaded into the canal fin. The titanium blocks were bolted together to provide a fluid-tight seal. Sodium hypochlorite was delivered at a previously-determined flow rate of 1 mL/min that produced either negligible or no irrigant extrusion pressure into the periapex for all the techniques examined. Nine irrigation delivery/agitation techniques were examined: NaviTip passive irrigation control, Max-i-Probe^® side-vented needle passive irrigation, manual dynamic agitation (MDA) using non-fitting and well-fitting gutta-percha points, EndoActivator™ sonic agitation with medium and large points, VPro™ EndoSafe™ irrigation system, VPro™ StreamClean™ continuous ultrasonic irrigation and EndoVac apical negative pressure irrigation. Débridement efficacies were analysed with Kruskal–Wallis ANOVA and Dunn's multiple comparisons tests (α = 0.05).ResultsEndoVac was the only technique that removed more than 99% calcium hydroxide debris from the canal fin at the predefined flow rate. This group was significantly different (p < 0.05) from the other groups that exhibited incomplete Ca(OH)₂ removal.ConclusionsThe ability of the EndoVac system to significantly clean more debris from a mechanically inaccessible recess of the model curved root canal may be caused by robust bubble formation during irrigant delivery, creating higher wall shear stresses by a two-phase air–liquid flow phenomenon that is well known in other industrial débridement systems.     

养心汤联合倍他乐克治疗扩张性心肌病合并心力衰竭临床研究

目的:观察养心汤联合倍他乐克对扩张性心肌病合并心力衰竭患者的临床疗效,及对血清中高迁移率族蛋白B1(high mobility group protein,HMGB1)、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)及白细胞介素-6(Interleukin-6,IL-6)含量的影响。方法:将80例扩张性心肌病合并心力衰竭患者随机分为治疗组和对照组,每组40例。两组患者均采用西医常规治疗。对照组口服倍他乐克治疗;治疗组在对照组基础上加用养心汤治疗,方药组成:黄芪20 g,白茯苓15 g,茯神15 g,半夏曲15 g,当归15 g,川芎9 g,远志9 g,肉桂9 g,柏子仁9 g,酸枣仁12 g,北五味子12 g,人参10 g,甘草10 g。每天1剂,常规水煮分早晚温服。两组患者均连续治疗3个月。比较两组患者左心室射血分数(left ventricular ejection fraction,LVEF)、舒张早期/舒张晚期最大血流速度(E/A)、6 min步行试验(6-minute walk test,6 MWT)、心力衰竭疗效积分、心率变异性和临床疗效,并检测两组患者血清中HMGB1、TNF-α及IL-6含量。结果:治疗后,治疗组患者的LVEF、E/A、6 MWT及心率变异性指标显著高于对照组,差异有统计学意义(P0.01);心力衰竭计分系统各指标评分明显少于对照组,差异有统计学意义(P0.01);治疗组有效率为95%,显著高于对照组75%,差异有统计学意义(P0.05);治疗组患者血清中HMGB1、TNF-α及IL-6水平显著少于对照组,差异有统计学意义(P0.01)。结论:养心汤联合倍他乐克对扩张性心肌病并心力衰竭患者,可改善患的心功能和心率变异性,提高临床疗效,其抑制患者血清中HMGB1、TNF-α及IL-6含量可能与治疗作用有关。     

荧光标记法比较4种表面处理方式种植体骨矿化沉积率的研究

目的荧光标记法观察比较4种表面处理方式种植体周围骨矿化沉积率的差异。方法微创拔除4只Beagle犬双侧下颌4颗前磨牙,待拔牙创愈合3个月后,植入奥齿泰种植体40颗,其中机械形态表面(ma-chined morphology,MM)组4颗,喷砂加酸蚀(sand blasted with alumina and acid etched,SA)组、可吸收性研磨介质(resorbable blasting media,RBM)组和生物化学喷砂酸蚀组(biochemistry sand blasted with alumina and acid etched,Bio-SA)组各12颗,愈合3个月,处死前13、14 d和3、4 d分别注射盐酸四环素和钙黄绿素,制取标本并置于70%酒精固定,采用塑料包埋技术制作骨磨片,荧光显微镜下观察,测量骨矿化沉积率。结果螺纹间及远离螺纹区域新骨矿化沉积率在4组间的差异均没有统计学意义(P>0.05);单独比较每组种植体螺纹间及远离区域骨矿化沉积率的差异性,RBM组及SA组组内差异没有统计学意义(P>0.05),而MM组和Bio-SA组组内差异具有统计学意义(P<0.05)。结论采用塑料包埋技术,通过荧光标记法能成功观察到新骨矿化沉积的情况;种植体植入3个月后,4种不同粗糙程度的种植体螺纹间及远离螺纹区域骨矿化沉积率没有差异性,而经机械形态表面处理的种植体和生物化学喷砂酸蚀处理的种植体,螺纹间骨矿化沉积比远离螺纹区域快。     

Prognostic factors for recurrence of gastrointestinal bleeding due to Dieulafoy's lesion

AIM: To analyze the effectiveness of the endoscopic therapy and to identify prognostic factors for recurrent bleeding.METHODS: Retrospective study of patients with gastrointestinal bleeding secondary to Dieulafoy’s lesion (DL) from 2005 to 2011. We analyzed the demographic characteristics of the patients, risk factors for gastrointestinal bleeding, endoscopic findings, characteristics of the endoscopic treatment, and the recurrence of bleeding. We included cases in which endoscopy described a lesion compatible with Dieulafoy. We excluded patients who had potentially bleeding lesions such as angiodysplasia in other areas or had undergone other gastrointestinal endoscopic procedures.RESULTS: Twenty-nine patients with DL were identified. Most of them were men with an average age of 71.5 years. Fifty-five percent of the patients received antiaggregatory or anticoagulant therapy. The most common location for DL was the stomach (51.7%). The main type of bleeding was oozing in 65.5% of cases. In 27.6% of cases, there was arterial (spurting) bleeding, and 6.9% of the patients presented with an adherent clot. A single endoscopic treatment was applied to nine patients (31%); eight of them with adrenaline and one with argon, while 69% of the patients received combined treatment. Six patients (20.7%) presented with recurrent bleeding at a median of 4 d after endoscopy (interquartile range = 97.75). Within these six patients, the new endoscopic treatment obtained a therapeutic success of 100%. The presence of arterial bleeding at endoscopy was associated with a higher recurrence rate for bleeding (50% vs 33.3% for other type of bleeding) [P = 0.024, odds ratio (OR) = 8.5, 95% CI = 1.13-63.87]. The use of combined endoscopic treatment prevented the recurrence of bleeding (10% vs 44.4% of single treatment) (P = 0.034, OR = 0.14, 95% CI = 0.19-0.99).CONCLUSION: Endoscopic treatment of DL is safe and effective. Adrenaline monotherapy and arterial (spurting) bleeding are associated with a high rate of bleeding recurrence.     

XC-A30A型全自动血沉分析仪的应用评价

目的探讨XC-A30A型全自动血沉分析仪测定红细胞沉降率(ESR)的重复性、准确性及影响因素。方法抽取高、中、低三组血沉值共27份进行重复性试验,对做血沉检查的198例患者,采用两法测定,以统计学方法分析仪器法的准确性,抽取10例贫血患者标本(压积<0.30)和10例压积正常且魏氏法ESR值在21～100 mm/h的标本对照,分析贫血标本用仪器测定的可行性。结果重复性:除1例(CV为16.1%)外,其余26例CV均<5%。准确性:ESR值在2～100 mm/h各组差异无统计学意义(P>0.05),但ESR值>100 mm/h者两组差异有统计学意义(P<0.05)。贫血标本采用两法测定的差值与对照组比较差异有统计学意义(P<0.05)。结论 XC-A30A型全自动血沉分析仪具有良好的重复性,准确性较高,贫血标本用该仪器测定准确性也较高,适合医院快速准确的报告血沉结果。但对于ESR>100 mm/h时建议用手工法复查。