彩色多普勒超声监测斜视手术对眼血流动力学影响

目的探讨斜视手术对眼血流动力学影响,评价多普勒超声监测眼动脉血供的临床价值.方法筛选斜视患者51例51只眼行1或2 条水平直肌后徙-截腱术.术前、术后1周、1个月分别用彩色多普勒超声诊断仪测量眼动脉(OA) 、睫状后动脉(PCA)、视网膜中央动脉(CRA)的收缩期血流速度峰值(Vs)、舒张末期血流速度(Vd)及阻力指数(RI),比较血流改变并与30例正常人对照.结果1.斜视眼术前患眼OA、PCA、CRA血流参数与正常组比较无显著性意义(P＞0.05);2.斜视眼术后1周眼动脉Vs明显升高、PI、RI升高(P＜0.05);3.斜视眼术后1个月OA、PCA、CRA各血流参数与术前比较,无显著性意义(P＞0.05).结论手术可以引起短期眼组织缺血,但随着手术激惹的消失及广泛侧枝循环的建立,1条或2条水平直肌截断手术不会引起眼前节缺血,多普勒超声是评价眼血流动力学变化的敏感方法.     

彩色多普勒超声监测斜视手术对眼血流动力学影

目的 :探讨斜视手术对眼血流动力学影响 ,评价多普勒超声监测眼动脉血供的临床价值。方法 :筛选斜视患者 51例 51只眼行 1或 2条水平直肌后徙 -截腱术。术前、术后 1周、 1个月分别用彩色多普勒超声诊断仪测量眼动脉 (OA)、睫状后动脉 (PCA)、视网膜中央动脉 (CRA)的收缩期血流速度峰值 (Vs)、舒张末期血流速度 (Vd)及阻力指数 (RI) ,比较血流改变并与 3 0例正常人对照。结果 :1.斜视眼术前患眼 OA、 PCA、 CRA血流参数与正常组比较无显著性意义 (P>0 .0 5) ;2 .斜视眼术后 1周眼动脉 Vs明显升高、 PI、 RI升高 (P<0 .0 5) ;3 .斜视眼术后 1个月 OA、PCA、 CRA各血流参数与术前比较 ,无显著性意义 (P>0 .0 5)。结论 :手术可以引起短期眼组织缺血 ,但随着手术激惹的消失及广泛侧枝循环的建立 ,1条或 2条水平直肌截断手术不会引起眼前节缺血 ,多普勒超声是评价眼血流动力学变化的敏感方法     

彩色多普勒超声对正常老年人眼动脉和视网膜中央动脉血流速度测定

本文应用彩色多普勒超声测量正常老年人68例136只眼的眼动脉（OA）和视网膜中央动脉（CRA）血流速度。结果，正常老年人OA收缩期峰值血流速度32．54±7．69cm／s，舒张末期血流速度9．10±2．66cm／s，阻力指数0．72±0．06，搏动指数1．67±0．43。CRA收缩期峰值血流速度9．80±1．67cm／s，舒张末期血流速度4．10±0．90cm／s，阻力指数0．60±0．10，搏动指数1．15±0．21。老年人年龄组间OA和CRA的收缩期与舒张末期血流速度无差异而阻力指数和搏动指数随年龄增长有差异（P＜0．05）。     

彩色多普勒超声对高脂血症患者球后血流动力学研究

目的：研究高脂血症患者眼动脉（OA）和视网膜中央动脉（CRA）的血流动力学改变。方法：应用彩色多普勒超声检测35例正常对照组、43例高脂血症患者OA和CRA的收缩期峰值流速（Vs）、舒张末期流速（Vd）和阻力指数（RI）。结果：与正常对照组比较,高脂血症患者OA和CRA Vs降低（P<0.05）,RI升高（P<0.05）。结论：高脂血症患者OA和CRA的血流速度降低、循环阻力增加,视网膜血液供应不良。彩色多普勒超声对高脂血症患者微血管病变的研究具有实用价值。     

彩色多普勒超声对正常眼压性青光眼血流动力学的研究

目的研究正常眼压性青光眼视神经的血液供应状况。方法用彩色多普勒超声检测正常眼压性青光眼和正常眼眼动脉、视网膜中央动脉和睫状后短动脉的收缩期峰值血流速度（PSv）、舒张末期血流速度（EDV）、阻力指数（RI）。结果正常眼压性青光眼组中眼动脉（OA）、视网膜中央动脉（CRA）、睫状后短动脉（SPCA）的PSV、EDV较正常对照组减慢,差异具有统计学意义（t分别=2．83、4．57、2．94、3．17、6．69、5．22,P均〈0．05）;OA、CRA、SPCA的RI较正常对照组增高,差异具有统计学意义（t分别=2．75、2．94、2．89,P均〈0．05）。结论正常眼压性青光眼的视神经存在缺血因素,彩色多普勒超声对其早期诊断有重要价值。     

福辛普利对糖尿病患者视网膜中央动脉血流动力学的影响

目的 观察糖尿病患者用福辛普利治疗前后视网膜中央动脉（CRA）血流动力学变化。方法 19例（38眼）糖尿病患者给予福辛普利10mg/d,于治疗前和治疗后1周用彩色多普勒超声检测CRA收缩期峰值血流速度（Vs）、舒张末期血流速度（Vd）、平均血流速度（Vm）、搏动指数（PI）和阻力指数（RI）,并与正常组对照。结果 糖尿病患者CRA的Vs、Vd、Vm低,而PI、RI高于对照组,治疗后患者的Vs、Vd和Vm增加,PI、RI降低（P＜0.05或0.01）。结论 福辛普利能改善糖尿病患者CRA血流动力学,彩色多普勒超声可用于评价糖尿病患者CRA血流动力学变化。     

彩色多普勒超声评价兔肾缺血再灌注前后肾动脉血流动力学变化

目的评价兔肾缺血再灌注24h内肾动脉血流动力学变化。方法运用彩色多普勒超声技术分别监测12只成年日本大白兔肾缺血再灌注前、再灌注后2h、8h及24h肾主动脉、段动脉及叶间动脉的血流动力学改变,测定上述动脉收缩期峰值速度（V max）、舒张末期速度（Vd）、时间平均血流速度（T Amax）、搏动指数（PI）及阻力指数（RI）。结果与缺血再灌注前比较,再灌注2h肾主动脉、段动脉及叶间动脉血流动力学变化差异无统计学意义;再灌注8h肾段动脉、叶间动脉RI增高（P〈0．05）;再灌注24h肾主动脉、段动脉及叶间动脉V max升高、RI和PI增高（P〈0．05）。结论彩色多普勒超声是评价兔肾缺血再灌注24h内肾动脉血流动力学改变的有效方法。     

糖尿病患者眼动脉、视网膜中央动脉和睫后短动脉血流参数变化的研究

目的：利用的彩色多普勒技术测量并研究糖尿病视网膜病变（DR）中眼动脉、视网膜中央动脉和睫后短动脉的血流参数的变化。方法：测量不同程度DR病人的眼动脉、视网膜中央动脉和睫后短动脉收缩峰值流速（PSV）、舒张末期速度（EDV）和阻力指数（RI）。结果：所有DR和重度DR的OA的CRA中PSV。重度DR的CRA和PCA的EDV，所有DR中CRA和PCA的RI与健康对照组对比具有统计学意义。结论：视网膜中央动脉是DR中的血流动力学变化的敏感指标。彩色多普勒超声是评价糖尿病视网膜病变时眼内动脉血流动力学变化的有效方法。     

玻璃体腔注射抗VEGF药物对糖尿病性黄斑水肿患者眼部血流动力学的影响

目的观察糖尿病性黄斑水肿(DME)患者经玻璃体腔注射抗血管内皮生长因子(VEGF)药物治疗后眼球后动脉血流的变化。方法前瞻性选取2016年11月至2017年8月期间在首都医科大学附属北京友谊医院收治伴有DME的糖尿病视网膜病变患者20例(20眼)。彩色多普勒超声检查检测患者治疗前及治疗后l d、1周的眼球后血管视网膜中央动脉(CRA)、眼动脉(OA)血流动力学参数,包括收缩期峰值流速(PSV)、舒张末期血流速度(EDV)、阻力指数(RI)及搏动指数(PI)。比较分析治疗前后的眼血流变化。结果 20例(20眼) DME患者平均年龄为(61. 65±10. 02)岁,其中男性11例(11眼),女性9例(9眼)术后第1天注射眼CRA的眼血流指标PSV、EDV、P1、R1结果分别为7. 22±1. 84 cm/s、1. 88±0. 49 cm/s、1. 41±0. 17、0. 73±0. 05,与术前进行比较,呈现明显下降(P 0. 01),RI、PI差异无统计学意义(P 0. 05)。术后1周注射眼的该4项眼血流指标差异均无统计学意义(P 0. 05)。OA的4项眼血流指标治疗前后比较,差异无统计学意义(P 0. 05)。患者对侧眼在治疗前后比较,CRA、OA的眼血流指标差异均无统计学意义(P 0. 05)。结论玻璃体腔抗VEGF注药可短暂影响DME患者注射眼的眼部血流,不影响对侧眼的眼血流动力学。     

彩色多普勒成像对裂孔源性视网膜脱离后眼血流动力学的研究

目的：应用彩色多普勒成像（CDI）观察视网膜脱离后眼血流动力学的改变。方法：采用CDI对54例单眼视网膜脱离患者的眼动态（OA）,视网膜中央动脉（CRA）的收缩期峰值流速（Vmax)、舒张末期流速（Vmin)及阻力指数（RI）进行测量,以对侧正常眼作对照。结果：网脱眼CRA的Vmax降低,RI升高;网脱眼OA的Vmax降低,并随年龄增长明显下降,而网脱眼CRA和OA的Vmin以及OA的AI与对照组比较,差异无显著性。结论：视网膜脱离后眼动脉、视网膜中央动脉的血流速度下降,眼动脉血流速度与年龄呈负相关。     

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.     

Dissociable correlates of two classes of retrieval processing in prefrontal cortex

Although substantial evidence suggests that the prefrontal cortex (PFC) implements processes that are critical for accurate episodic memory judgments, the specific roles of different PFC subregions remain unclear. Here, we used event-related functional magnetic resonance imaging to distinguish between prefrontal activity related to operations that (1) influence processing of retrieval cues based on current task demands, or (2) are involved in monitoring the outputs of retrieval. Fourteen participants studied auditory words spoken by a male or female speaker and completed memory tests in which the stimuli were unstudied foil words and studied words spoken by either the same speaker at study, or the alternate speaker. On "general" test trials, participants were to determine whether each word was studied, regardless of the voice of the speaker, whereas on "specific" test trials, participants were to additionally distinguish between studied words that were spoken in the same voice or a different voice at study. Thus, on specific test trials, participants were explicitly required to attend to voice information in order to evaluate each test item. Anterior (right BA 10), dorsolateral prefrontal (right BA 46), and inferior frontal (bilateral BA 47/12) regions were more active during specific than during general trials. Activation in anterior and dorsolateral PFC was enhanced during specific test trials even in response to unstudied items, suggesting that activation in these regions was related to the differential processing of retrieval cues in the two tasks. In contrast, differences between specific and general test trials in inferior frontal regions (bilateral BA 47/12) were seen only for studied items, suggesting a role for these regions in post-retrieval monitoring processes. Results from this study are consistent with the idea that different PFC subregions implement distinct, but complementary processes that collectively support accurate episodic memory judgments.     

俯卧位通气对高海拔地区肺复张治疗无效急性呼吸窘迫综合征患者氧合的影响

目的 探讨俯卧位通气对高海拔地区肺复张术(RM)治疗无效急性呼吸窘迫综合征(ARDS)患者的治疗作用.方法 从海拔2260m的地区医院筛选RM治疗无效的41例ARDS患者[平均氧合指数( PaO2/FiO2)较RM前升高＜20％视为RM无效],依不同病因分为肺内源性ARDS组(ARDSp组)和肺外源性ARDS组(ARDSexp组),每组再按信封法随机分为俯卧位组和仰卧位组,即ARDSp俯卧位组(11例)、ARDSp仰卧位组(9例)、ARDSexp俯卧位组(10例)、ARDSexp仰卧位组(11例).在通气前及通气1、2、3、4h监测动脉血氧分压( PaO2)、PaO2/FiO2、静态顺应性(Cst)、气道阻力(Raw)的变化.结果 通气lh时,ARDSexp俯卧位组PaO2/FiO2( mm Hg,l mm Hg=0.133 kPa)即较通气前显著升高(157.4±40.6比129.3±48.7,P＜0.05),并随通气时间延长呈持续增高趋势,4h达峰值(219.1 ±41.1);且ARDSexp俯卧位组通气3h内PaO2/FiO2较其他3组显著增高,另3组间则差异无统计学意义.ARDSp俯卧位组、ARDSexp俯卧位组通气4h时PaO2/FiO2均较相应仰卧位组显著增高(208.8±39.7比127.4±47.1,219.1±41.1比124.9±50.8,均P＜0.05).4组通气前后Cst无显著改变,各组间差异也无统计学意义.ARDSp俯卧位组通气4h时Raw(cmH2O·L-1·s-1)较通气前显著降低(6.8±1.7比10.7±1.8,P＜0.05),且明显低于其他3组;其他3组各时间点Raw组内及组间比较差异均无统计学意义.结论 俯卧位通气作为ARDS机械通气重要策略之一,可以改善RM无效高原ARDS患者的氧合,为抢救患者赢得宝贵的时间.     

Digital imaging among medical facilities

The Department of Veterans Affairs (VA) in the USA operates a network of 172 medical centres which all utilize a hospital information system (HIS) which has been developed and is currently maintained by the VA. During the past several years, an image management and communication module has been developed, installed and clinically utilized at the Washington DC and Maryland VA Medical Centres. This image management and communication system, referred to as the decentralized hospital computer program (DHCP) imaging system, is fully integrated with a commercial picture archiving and communication system (PACS). The system is utilized to capture, archive, and display all images generated within the hospital including radiology, nuclear medicine, pathology, endoscopy, bronchoscopy, and dermatology, intraoperative photographs, ECG data, and a limited number of paper documents. The ultimate goal of the project is to have all patient text and image data available at any clinical workstation to any authorized user anywhere within the network of medical centres. Clinical requirements for an imaging workstation include ease of use, rapid and reliable access to the complete set of patient information, and images which are of acceptable quality to meet the requirements of the user and the subspecialty. Patient confidentiality and data security must be safeguarded at all times. Integration of the images with the remainder of the patient's database was found to be critical to the success of the project. The experience at the Washington and Maryland facilities suggests that an imaging system that is successfully integrated with a hospital information system can provide substantial clinical and economic benefits both within and among medical centres. Clinical acceptance and utilization of the system has been excellent, particularly in diagnostic radiology where DHCP Imaging has been interfaced to a commercial PAC system. Based upon this initial experience, the VA has begun to deploy the system throughout its large network of medical centres.     

Myocardial elastography at both high temporal and spatial resolution for the detection of infarcts

Myocardial elastography is a novel method for noninvasively assessing regional myocardial function, with the advantages of high spatial and temporal resolution and high signal-to-noise ratio (SNR). In this paper, in-vivo experiments were performed in anesthetized normal and infarcted mice (one day after left anterior descending coronary artery [LAD] ligation) using a high-resolution (30 MHz) ultrasound system (Vevo 770, VisualSonics Inc., Toronto, ON, Canada). Radiofrequency (RF) signals of the left ventricle (LV) in longitudinal (long-axis) view and the associated electrocardiogram (ECG) were simultaneously acquired. Using a retrospective ECG gating technique, 2-D full field-of-view RF frames were acquired at an extremely high frame rate (8 kHz) that resulted in high-quality incremental displacement and strain estimation of the myocardium. The incremental results were further accumulated to obtain the cumulative displacements and strains. Two-dimensional and M-mode displacement images and strain images (elastograms), as well as displacement and strain profiles as a function of time, were compared between normal and infarcted mice. Incremental results clearly depicted cardiac events including LV contraction, LV relaxation and isovolumetric phases in both normal and infarcted mice, and also evidently indicated reduced motion and deformation in the infarcted myocardium. The elastograms indicated that the infarcted regions underwent thinning during systole rather than thickening, as in the normal case. The cumulative elastograms were found to have higher elastographic SNR (SNR(e)) than the incremental elastograms (e.g., 10.6 vs. 4.7 in a normal myocardium, and 6.0 vs. 2.4 in an infarcted myocardium). Finally, preliminary statistical results from nine normal (m = 9) and seven infarcted (n = 7) mice indicated the capability of the cumulative strain in differentiating infracted from normal myocardia. In conclusion, myocardial elastography could provide regional strain information at simultaneously high temporal (>/=0.125 ms) and spatial ( approximately 55 microm) resolution as well as high precision ( approximately 0.05 microm displacement). This technique was thus capable of accurately characterizing normal myocardial function throughout an entire cardiac cycle, at the same high resolution, and detecting and localizing myocardial infarction in vivo.     

Clinical Pharmacokinetics of Morphine

Morphine, the most widely used mu-opioid analgesic for acute and chronic pain, is the standard against which new analgesics are measured. A thorough understanding of the pharmacokinetics of morphine is required in order to safely and effectively use this analgesic in a wide variety of patients with different levels of organ function. A MEDLINE search was conducted to identify literature published between 1966 and January 2002 relevant to the pharmacokinetics of morphine. These publications were reviewed and the literature summarized regarding unique and clinically important elements of morphine disposition relative to its parenteral administration (including intravenous, intramuscular, subcutaneous, epidural and intrathecal administration), absorption profile (immediate release, controlled release, and sublingual/buccal, and rectal administration), distribution, and its metabolism/ excretion. Special populations, including infants, elderly, and those with renal/liver failure, have a unique morphine pharmacokinetic profile that must be taken into account in order to maximize analgesic efficacy and reduce the risk of adverse events.