应变-血压指数评价终末期肾病患者中型动脉弹性

目的探讨应用应变-血压指数评价终末期肾病患者肱动脉和胫前动脉弹性的可行性及临床价值。方法随机选取终末期肾病患者39例作为终末期肾病组,健康志愿者46例作为对照组。全部应用应变和应变率成像对肱动脉和胫前动脉进行检查。通过应变和应变率成像获得肱动脉和胫前动脉的最大圆周应变,同时测量被检者肱动脉和胫前动脉血压,计算肱动脉和胫前动脉的应变-血压指数,对终末期肾病组和对照组的参数进行对比分析。结果终末期肾病组的胫前动脉应变-血压指数(4.01%±0.59%)明显低于对照组(5.71%±0.55%,P<0.01);终末期肾病组和对照组的肱动脉应变-血压指数(3.82%±0.39%比3.95%±0.46%)差异无统计学意义(P>0.05)。结论应变-血压指数可以作为评价终末期肾病患者中型动脉弹性改变的新指标。     

Comparative study of shear wave velocities using acoustic radiation force impulse technology in hepatocellular carcinoma: the extent of radiofrequency ablation

Background/Aims

The purpose of this study was to assess the value of acoustic radiation force impulse (ARFI) for predicting the extent of radiofrequency ablation (RFA) in hepatocellular carcinoma (HCC) by correlating the elasticity of HCC and peritumoral parenchyma (as measured by ARFI) with the extent of ablation determined by computed tomography (CT).

Methods

From September 2009 to June 2011, 158 patients underwent RFA ablation for HCC (single, ≤3 cm). We evaluated the data of a total of 38 prospectively enrolled patients who underwent both ARFI imaging and contrast-enhanced CT after one session of 12 minutes of RFA without a change in needle position. The ARFI imaging indices, including the mean shear wave velocity (SWV) of HCC, mean SWV of the peritumoral parenchyma and tumor size, were evaluated to determine the statistical correlation with RFA extent after one session of 12 minutes of RFA.

Results

A stiffer liver parenchyma in patients with cirrhosis results in a smaller ablation zone.

Conclusions

SWV of ARFI in liver parenchyma was well correlated with RFA extent. After evaluating the correlation between ARFI and RFA extent, we suggest that the SWV in liver parenchyma might be a non-invasive supplementary tool for predicting the extent of RFA.     

Fibrosis Evaluation by Transient Elastography in Patients With Long-Term Sustained HCV Clearance

Background

Reversibility of advanced fibrosis after HCV-clearance is an important goal of therapy.

Objectives

Measuring liver stiffness (LS) by transient elastography (TE) might be helpful in this setting.

Patients and Methods

We evaluated 104 patients with biopsy-proven chronic hepatitis C (CHC) and sustained virological response (SVR) after Peg-Interferon (IFN) plus ribavirin since at least 18 months. HCV-eradication was confirmed searching for serum HCV-RNA (TMA® sensitivity > 5-10 IU/ml). Data from literature reported the best LS cut-off values for different stages of liver fibrosis were 7.1 kPa for Metavir stage 2 (F2), 9.5 kPa for F3 and 12.5 for cirrhosis (F4).

Results

TE was not reliable in four SVR obese patients. Metavir-stage of biopsy was F0-1 in 28, F2 in 47, F3 in 17 and F4 in eight patients. The median interval elapsed since achieving SVR was 36 months (range: 18-77, SD¬¬:18). Stratifying patients according to the histological stage assessed before treatment, a clear-cut gradient of LS values was observed from F0-1: median: 3.8 kPa (range: 3.5-4.9) to F2: 4.6 kPa (3.8-6.0), F3: 6.2 kPa (4.8-8.6) and F4: 8.4 kPa (6.2-9.2) (P = 0.001). Overall, 86 patients had lower values of LS than the expected LS values according to Metavir-stage. At multivariate logistic analysis γ-GT and histological steatosis were independently associated with persistence of higher values of LS.

Conclusion

Long term responders to IFN-based therapies have lower LS values than those who are untreated and still viraemic. High levels of γ-GT and liver steatosis, all markers of insulin resistance, may hamper reduction of liver stiffness after HCV-clearance.     

替米沙坦与氨氯地平对2型糖尿病合并轻中度高血压患者血管弹性功能改善作用的对比研究

目的 比较替米沙坦、氨氯地平两种降压药在改善2型糖尿病合并轻中度高血压患者动脉弹性功能方面的差异.方法 72例2型糖尿病合并轻中度高血压患者,随机分成两组,每组36例,分别用替米沙坦、氨氯地平治疗.有67例(替米沙坦组33例、氨氯地平组34例)纳入最终统计数据.在服药前和服药1、6个月后应用科林波形分析仪PWV/ABI型仪器测量患者的臂踝脉搏波传导速度(baPWV).结果 降压治疗后两组的收缩压、舒张压、脉压均较治疗前明显降低(P＜0.01);心率、空腹血糖、糖化血红蛋白则未见明显变化.两组baPWV经降压治疗后均有所下降,治疗前替米沙坦组、氨氯地平组分别为1 763.48±307.57 cm/s、1 722.71±274.67 cm/s,治疗1个月后替米沙坦组、氨氯地平组分别为1 496.42±229.37 cm/s、1 550.12±236.06 cm/s,治疗6个月后替米沙坦组、氨氯地平组分别为1 436.52±216.23 cm/s、1 465.68±237.79 cm/s.治疗1个月后及治疗6个月后与治疗前比较有显著差异(P ＜0.001).治疗6个月后与治疗1个月后比较亦有显著差异(替米沙坦组,P＜0.05;氨氯地平组,P＜0.001).降压治疗1个月后两组的baPWV均数差值变化及降压治疗6个月后两组的baPWV均数差值变化均为替米沙坦组大于氨氯地平组,在两组间比较差异有统计学意义(P＜0.05).结论 研究结果提示应用替米沙坦、氨氯地平降压均能改善2型糖尿病合并高血压患者动脉弹性功能.降压治疗1个月及6个月时,替米沙坦改善动脉弹性的作用更为明显.血压降至正常并平稳后继续应用替米沙坦、氨氯地平降压治疗对于动脉弹性仍然存在持续的改善作用.     

采用血管内超声弹性成像技术分析动脉粥样硬化斑块负荷与面积应变的关系

目的 采用血管内超声弹性成像技术评价斑块负荷（PB）与面积应变（AS）的关系。方法 对40只雄性纯种新西兰兔全程高脂饲料喂养。第2周末行腹主动脉球囊拉伤术。第12周末行腹主动脉血管内超声检查,对每只动物选择两个等回声斑块,采集不少于3个心动周期的原位血管内超声图像,选择舒张末期连续2帧原位图像,构建血管内超声弹性图。测量并计算血管外弹力膜面积（EEM_area）、血管腔面积（Lumen_area）、斑块面积（PA）、PB、血管外弹力膜体积（EEM_volume）、血管腔体积（Lumen_volume）、斑块体积（PV）、斑块体积负荷（PVB）、斑块最大厚度（T_max）、斑块最小厚度（T_min）、斑块偏心指数（EI）、血管重构指数（RI）及AS。根据PB不同,将斑块分为低负荷斑块组（PB≤40%）和高负荷斑块组（PB>40%）,并对两组间以上参数的差异、斑块形态学和力学参数的关系等进行统计学分析。结果 两组的PA、PV、PB、PVB、T_min、T_max、Lumen_area、Lumen_volume、EI差异均有统计学意义（P均<0.01）。经逐步多元线性回归分析,回归方程为：Ŷ=－6.921+10.430X₁+12.207X₂（Ŷ：AS;X₁：EI;X₂：PB;R²=0.272,P<0.001）。在矫正偏心指数对AS的影响后,低负荷斑块组的AS明显小于高负荷斑块组（P=0.010）。结论 动脉粥样硬化斑块的负荷对斑块力学稳定性有影响。高负荷斑块较低负荷斑块更易受损。     

Carotid stiffness and the risk of new vascular events in patients with manifest cardiovascular disease. The SMART study.

AIMS: To study whether arterial stiffness is related to risk of new vascular events in patients with manifest arterial disease and to examine whether this relation varies between patients who differ with respect to baseline vascular risk, arterial stiffness, or systolic blood pressure (SBP). METHODS AND RESULTS: The study was performed in the first consecutive 2183 patients with manifest arterial disease enrolled in the SMART study (Second Manifestations of ARTerial disease), a cohort study among patients with manifest arterial disease or cardiovascular risk factors. Common carotid distension (i.e. the change in carotid diameter in systole relative to diastole) was measured at baseline by ultrasonography. With the distension, several stiffness parameters were determined. In the entire cohort, none of the carotid artery stiffness parameters was related to the occurrence of vascular events. However, decreased stiffness was related to decreased vascular risk in subjects with low baseline SBP. The relation of carotid stiffness with vascular events did not differ between tertiles of baseline risk and carotid stiffness. CONCLUSION: Carotid artery stiffness is no independent risk factor for vascular events in patients with manifest arterial disease. However, in patients with low SBP, decreased carotid stiffness may indicate a decreased risk of vascular events.     

超声弹性成像技术诊断甲状腺弥漫性病变的研究进展

甲状腺弥漫性病变因在常规超声声像图上有许多共同表现,鉴别诊断较困难。超声弹性成像技术是近年新发展的一种超声成像技术,能够获得组织内部弹性分布的定量信息,已在肝脏、乳腺、甲状腺等疾病中表现出一定的临床应用价值。本文就超声弹性成像技术在甲状腺弥漫性病变中的应用进展进行综述。     

先天性上睑下垂发病机制与手术设计的研究

目的：探讨先天性上睑下垂的发病机制，为手术方法的设计提供依据。方法：对73例（103眼）先天性上睑下垂进行了上睑提肌肌力，肌电图，肌弹性的测量及解剖学，组织学方面的观察。结果：肌电图显示该肌收缩强度正常平均值为500uV/D，部分肌力较差的患者（18％）肌收缩强度达260－350uV/D接近正常平均值，少数骨力在3－5mm的患者（9．99％）肌收缩强度达到正常平均值。术中观察85％的患者上睑提肌弹性良好，肌伸民可达15－20mm。组织学观察发现17％的患者上睑提肌为正常组织，结论：先天性上睑下垂的发生原因除肌发育不良外，上睑提肌内，外角过度紧张也是其重要因素，并根据病因制定了合理有效的手术 方式。     

Characterization of the structure and properties of authentic and counterfeit polypropylene surgical meshes

A counterfeit version of the Ethicon Prolene polypropylene mesh was distributed to hospitals and clinics and unintentionally implanted into patients undergoing tension-free hernia repair. On December 19, 2003, the Food and Drug Administration (FDA) issued a public health web notification indicating that the counterfeit mesh was not sterile or safe to use. To develop safety recommendations for patients with the counterfeit mesh implant, we compared the counterfeit’s structural, physical, chemical and mechanical properties with polypropylene meshes previously cleared by FDA. The mesh fibers for all the products tested were found to have similar chemical and physical properties. The mechanical properties were directly related to the knitted structure (loop size, repeat distance, fabric tightness) and the porosity. Extracts from the counterfeit mesh passed cytotoxicity screening tests. The FDA further recommended that if the mesh had been inadvertently implanted, then those patients should be monitored as would be the practice for any patient with an implanted surgical mesh.     

个人收入与医疗服务需求及其弹性

通常情况下，当收入增长时，消费者对霜种商品需求的增加减少将做出必然的反映，两者之间增量的比即是消费者对这种商品的收需求弹性。分析医疗服务需求收入弹性，从总体上讲呈弱势，高收入组弹性大于低收入组弹性；医疗费用占收入的比重是一个增长的趋势，贫困和低收入人群医疗费用支出占收的比重高于高收入人群。