ET技术监测非洛地平对高血压患者动脉弹性功能变化的研究

目的采用血管弹性量化分析技术-血管回声跟踪技术（Echo-Tracking,ET技术）观察非洛地平对早期高血压患者动脉弹性功能的影响。方法首次诊断原发性高血压（WHO/ISH原发高血压诊断标准）,最终符合实验要求56例纳入高血压治疗组,以血压水平正常范围内56人为健康对照组。高血压治疗组患者服用非洛地平（5～10 mg/d）,随访24周,治疗前后测定收缩压、舒张压、脉压差及心率,并利用ET技术获取动脉弹性功能指标,包括僵硬度指数、颈动脉脉搏波传导速度、反射波增强指数、压力-应变弹性指数、动脉顺应性、颈动脉内膜中层厚度。结果①治疗前高血压治疗组的收缩压、颈动脉内膜中层厚度、僵硬度指数、颈动脉脉搏波传导速度、压力-应变弹性指数各项指标均值都比健康对照组高（P〈0.05）;动脉顺应性低于对照组（P〈0.05）,差异都有显著性意义。②高血压治疗组使用非洛地平24周后,收缩压、僵硬度指数、颈动脉脉搏波传导速度、压力-应变弹性指数比用药前降低,差异有显著性意义（P〈0.05）;动脉顺应性升高,差异有显著性意义（P〈0.05）;颈动脉内膜中层厚度用药前后比较统计学无差异（P〉0.05）。结论①应用ET技术可无创、直观监测早期高血压患者动脉弹性功能减低。②非洛地平能显著改善早期高血压患者动脉弹性的作用,缓解动脉粥样硬化的发展。     

Slow stretching that mimics embryonic growth rate stimulates structural and mechanical development of tendon-like tissue in vitro

A distinctive feature of embryonic tendon development is the steady increase in collagen fibril diameter and associated improvement of tissue mechanical properties. A potential mechanical stimulus for these changes is slow stretching of the tendon during limb growth. Testing this hypothesis in vivo is complicated by the presence of other developmental processes including muscle development and innervation. Here we used a cell culture tendon-like construct to determine if slow stretch can explain the increases in fibril diameter and mechanical properties that are observed in vivo. Non-stretched constructs had an ultrastructural appearance and mechanical properties similar to those of early embryonic tendon. However, slowly stretching during 4 days in culture increased collagen fibril diameter, fibril packing volume, and mechanical stiffness, and thereby mimicked embryonic development. 3D EM showed cells with improved longitudinal alignment and elongated nuclei, which raises the hypothesis that nuclear deformation could be a novel mechanism during tendon development.     

Is the demand for alcohol in Indigenous Australian communities ‘price inelastic’?

Objective. To review the findings of a paper that has often been cited as evidence—with potentially adverse public health consequences—that the demand for alcohol in Indigenous Australian communities is not responsive to price and that, in the face of increasing alcohol prices, expenditure is diverted from basic sustenance to the purchase of alcohol. Methods. The raw data on income and various items of expenditure from the original study were entered in a database, a trend variable was created, and trends in measures of interest were tested using appropriate cross‐correlations. Results. Re‐analysis of the data did not support the findings of the original study. Conclusions. The original study does not contradict the general findings of the national and international literature that the demand for alcohol is sensitive to increases in price and does not provide evidence for the assertion that, other factors being equal, price controls on the availability of alcohol in Indigenous communities are likely to be ineffective.[Dennis Gray. Is the demand for alcohol in Indigenous Australian communities ‘price inelastic’? Drug Alcohol Rev 2012;31:818–822]     

血管回声跟踪技术评价绝经期妇女颈动脉弹性的临床研究

目的利用血管回声跟踪技术探讨绝经期妇女颈动脉弹性指标与血清激素指标的相关性。方法研究组35例,对照组30例,分别对两组患者颈动脉弹性（血管僵硬度B、弹性系数Ep、顺应性AC和膨大指数AI）、血清激素（一氧化氮NO、血清雌二醇E2、促卵泡生成素FSH、泌乳素PRL以及黄体生成素LH）含量进行检测和比较分析。结果研究组受试者左／右侧颈动脉弹性指标B、Ep、AI均明显高于对照组,AC明显低于对照组,研究组患者NO、E2明显低于对照组,FSH、PRL、LH明显高于对照组,数据经统计学比较具有显著差异（P〈0．05）;B、Ep、AI与NO呈负相关,而AC与NO呈正相关。结论妇女血清激素对于动脉弹性有明显的影响,由于雌激素的下降和NO的减少,绝经期妇女动脉血管易出现形变征兆。     

Vitreous deformation during eye movement

Retinal detachment results in visual loss and requires surgical treatment. The risk of retinal detachment depends, among other factors, on the vitreous rheology, which varies with age. To date, the viscoelasticity of the vitreous body has only been measured in cadaver eyes. However, the ex vivo and in vivo viscoelasticity may differ as a result of the effect of intravitreal membranes. Therefore, an MRI method and appropriate postprocessing tools were developed to determine the vitreous deformation and viscoelastic properties in the eyes of living humans. Nineteen subjects (eight women and 11 men; mean age, 33 years; age range, 14-62 years) gazed at a horizontal sinusoidal moving target during the segmented acquisition of complementary spatial modulation of magnetization images. The center of the lens and the scleral insertion of the optic nerve defined the imaging plane. The vitreous deformation was tracked with a dedicated algorithm and fitted with the commonly used viscoelastic model to determine the model parameters: the modified Womersley number a and the phase angle b. The vitreous deformation was successfully quantified in all 17 volunteers having a monophasic vitreous. The mean and standard deviation of the model parameters were determined to be 5.5 ± 1.3 for a and -2.3 ± 0.2 for b. The correlation coefficient (-0.76) between a and b was significant. At the eye movement frequency used, the mean storage and loss moduli of the vitreous were around 3 ± 1 hPa. For two subjects, the vitreous deformation was clearly polyphasic: some compartments of the vitreous were gel-like and others were liquefied. The borders of these compartments corresponded to reported intravitreal membrane patterns. Thus, the deformation of the vitreous can now be determined in situ, leaving the structure of the intravitreal membranes intact. Their effect on vitreous dynamics challenges actual vitreous viscoelastic models. The determination of the vitreous deformation will aid in the quantification of local vitreous stresses and their correlation with retinal detachment.     

The control of chromosome segregation during mitosis in epithelial cells by substrate elasticity

Materials of defined elasticity, including synthetic material scaffolds and tissue-derived matrices, can regulate biological responses of cells and in particular adhesion, migration, growth and differentiation which are essential parameters for tissue integration. These responses have been extensively investigated in interphase cells, but little is known whether and how material elasticity affects mitotic cells. We used polyelectrolyte multilayer films as model substrates with elastic modulus ranging from Eap = 0 up to Eap = 500 kPa and mitotic PtK2 epithelial cells to address these important questions. Soft substrates (Eap < 50 kPa) led to abnormal morphology in chromosome segregation, materialized by chromatin bridges and chromosome lagging. Frequency of these damages increased with decreasing substrate stiffness and was correlated with a pro-apoptotic phenotype. Mitotic spindle was not observed on soft substrates where formation of chromatin damages is due to low β1-integrin engagement and decrease of Rac1 activities. This work constitutes the first evidence that soft substrates hinder epithelial cell division. In perspective, our findings emphasize the prime incidence of the material elasticity on the fate of the phenotype, especially of stem cells in the mitotic phase.     

血管超声对阻塞性睡眠呼吸暂停综合征患者早期动脉粥样硬化检测指标的研究

目的:运用血管超声探讨阻塞性睡眠呼吸暂停综合征(obstructive sleep apnea syndrome,OSAS)与早期动脉粥样硬化间的相互关系?方法:选取不合并高血压的OSAS患者37例,以及40例同期健康志愿者作为对照组?应用血管超声内皮功能检测方法测得肱动脉血流介导的血管扩张性(flow-mediated dilation,FMD),运用动脉僵硬度分析(quantitative arterial stiffness,QAS)技术测量颈动脉各项弹性参数,包括血管扩张度(vascular expansibility,VE)?顺应性系数(compliance coefficient,CC)?僵硬度(stiffness index,?茁)?脉搏波传播系数(pulse wave velocity,PWV),分析两组上述指标间的差别?并用多导睡眠呼吸监测(polysomnograph,PSG)测得OSAS组的睡眠呼吸暂停低通气指数(apnea-hypopnea index,AHI)和最低脉氧饱和度(minimal pulse oxyhemoglobin saturation,miniSpO2)等血氧饱和度相关指标,与FMD值之间进行相关回归分析?对OSAS组中的20例患者进行持续气道内正压(continuous positive airway pressure,CPAP)治疗,并分析治疗前后各项参数的改变?结果:① 与正常对照组相比,OSAS组的FMD值及颈动脉弹性系数VE?CC明显降低,而?茁值及PWV明显升高(P < 0.05);② OSAS组中肱动脉FMD值与AHI?年龄??茁呈负相关(r = -0.325~-0.378,P均 < 0.05),与miniSpO2呈正相关(r = 0.504,P < 0.01),通过多元线性回归分析显示病例组中miniSpO2是FMD的独立预测因素(R2 = 0.548,P < 0.05);③与治疗前相比,治疗3个月后 FMD值及颈动脉弹性系数CC明显上升,而?茁值及PWV下降显著(P < 0.05)?结论:血管超声可发现OSAS患者早期就存在内皮损伤及弹性功能减退,同时CPAP治疗能够有效改善患者血管弹性及内皮功能?     

呼吸系统弹性阻力对急性肺损伤患者肺复张后氧合影响的荟萃分析

目的 探讨呼吸系统弹性阻力(respiratory system elasticity resistance,Ers)在急性肺损伤(acute lung injury,ALI)患者肺复张过程中氧合的影响.方法 收集1999年1月1日至2010年6月30日关于在肺复张对不同Ers急性肺损伤患者氧合影响的随机对照研究、前瞻观察性研究和病例对照研究,对于肺复张对Ers≥33.3 cmH2O/L(1 cmH2O=0.098 kPa)和Ers＜33.3 cmH2O/L(1 mmHg=0.133 kPa)的ALI患者氧合影响作Meta评价.结果 共281篇文献符合纳入标准,纳入文献共20篇,共纳人患者共395人,结果提示肺复张对高Ers患者氧合改善为(51.97±8.89)mmHg,血压下降(4.33±1.32)mmHg;对低Ers患者氧合改善为(35.13±10.33)mHg,血压下降(0.22±1.03)mmHg,肺复张对两组患者之间氧合改善和血压的影响差异具有统计学意义(P＜0.01).结论 肺复张能够改善ALI患者的氧合,对高Ers的ALI患者氧合改善更为明显;但对高Ers的患者循环影响更为明显.

Abstract：

Objective To investigate the effects of elasticity resistance (Ers) in respiratory system on oxygenation in patients with acute lung injury (ALI) after recruitment maneuvers (RM). Method Meta-analysis of data about the effects of recruitment maneuvers on oxygenation in ALI patients with different elasticity resistances in respiratory system carried out with pooling of study-oriented data stored in Pubmed, Embase, Web of Science databases from January 1999 to June 2010. Results A total of 281 articles were taken, and 20 of them included a sample size of 395 ALI patients. In patients treated with RM in different degrees of respiratory system elasticity resistance ( ≥33.3 cmH2O/L and ＜33.3 cmH2O/L), the effect of RM was better in patients with the high respiratory system elasticity resistance than that with the low one [(51.97 + 8.89) mmHg vs. (35.13 ± 10.33 ) mmHg], P ＜ 0. 01 ), but the high respiratory system elasticity resistance was potentially to lower blood pressure [(4. 33 ± 1.32 ) mmHg vs. (0.22 ± 1.03 ) mmHg],P ＜ 0.01 ). Conclusions This study suggests RM could improve oxygenation of ALI patients with high respiratory system elasticity resistance, and caution must be made to avoid hypotension during RM.