肝纤维化动物实验超声造影评估

目的 评估灰阶超声造影在兔肝纤维化模型的诊断价值.方法 硫代乙酰胺诱导兔肝纤维化模型,自身前后对照,分成S0组(正常对照组)、S1～S3组到S4组(肝硬化组).评估参数包括肝动脉(HA),门静脉(PV),肝实质(LP)和肝静脉(HV)开始显影时间(AT),并观察肝实质的灌注均匀性.结果 HAAT、PVAT、LPAT、HVAT随纤维化程度增加,基本呈递减趋势;HAAT S4组和S1组间差异有显著性意义(P<0.05);PVAT S4组与其他组间差异均有显著性意义(P<0.05);LPAT S4组与其他组间具有非常显著性意义(P<0.01);HVAT各组间比较均具有非常显著性意义(P<0.01);并且,与其他各组相比,S4组肝实质灌注不均差异非常显著(P<0.01).结论 灰阶超声造影有望成为无创伤性诊断肝纤维化的新指标.     

肝静脉血流定量分析与肝纤维化分期关系的研究

目的 定量分析慢性肝炎患者肝静脉血流最大正向血流速度(Vs)与最大逆向血流速度(Va)之和(△V),探讨其与肝纤维化分期的相关性.方法 应用超声检查114例慢性肝炎患者并计算△V,肝纤维化程度均由经超声引导下肝组织活检病理证实,并将△V与肝纤维化分期进行对照分析.结果 慢性肝炎肝纤维化血流速度的特征表现为:△V在S0～S3期之间差异无显著性,在S0、S1、S2、S3期分别与S4期之间差异具有统计学意义(P＜0.05).慢性肝炎肝纤维化分期中,△V对S4期的诊断敏感性为73.3%,特异性55.0%.当△V小于30 cm/s时,可诊断为早期肝硬化或肝硬化.结论 慢性肝炎肝静脉△V的变化,在S0～S3期之间无明显诊断意义,当△V小于30 cm/s时,对S4期的诊断有较高价值;超声检测慢性肝炎患者肝静脉△V,对判断慢性肝炎肝纤维化程度方面有一定的临床价值.     

超声量化指标与肝静脉波形分型在评价乙肝患者肝纤维化程度中的临床意义

目的探讨超声量化指标与肝静脉波形分型在评价乙肝患者肝纤维化程度中的临床意义。方法回顾性分析本院110例乙肝患者的临床资料,作为研究组;选取同期到本院体检的25例健康人,作为对照组。研究组入院确诊时、对照组体检时均分别行超声检查,评估超声量化指标、肝静脉波形分型。以肝穿刺病理结果为金标准,判断超声量化指标、肝静脉波形分型对肝纤维化程度诊断价值。结果研究组S1、S2、S3、S4期患者超声量化指标评分高于对照组(P<0.05);随着肝纤维化分期增加,研究组超声量化指标评分呈增高趋势(P<0.05);研究组S4期HVⅠ型+HVⅡ型率高于S0、S1、S2期及对照组,S3期HVⅠ型+HVⅡ型率高于S0、S1、S2期及对照组(P<0.05);ROC曲线显示肝静脉波形分型灵敏度、特异度较超声量化指标评分高。结论乙肝患者肝纤维化程度评估中超声量化指标与肝静脉波形分型均具有一定价值,且后者灵敏度、特异度更高。     

超声组织定征对慢性乙型肝炎肝纤维化的研究

目的探讨超声组织定征对慢性乙型肝炎不同程度肝纤维化进行灰阶测量的作用。方法用超声组织定征视频法测量慢性乙型肝炎患者二维声图像的灰阶值,并与其肝穿刺病理组织学纤维化分级对比。结果超声组织定征视频法测出的肝声像图的灰阶值在慢性乙型肝炎肝纤维化病理组织学分级中的差异有显著性意义(F=34.3,P<0.001),肝纤维化S0、S1、S2和S3各组间灰阶值的差异均有显著性意义(P<0.05)。结论超声组织定征视频法可对慢性乙型肝炎肝纤维化的程度进行声像图灰阶测量。     

实验性肝纤维化胆囊壁厚度及门静脉压力关系的研究

目的探讨超声检测肝纤维化胆囊壁厚度与门静脉压力变化的关系。方法40只家兔口服硫代乙酰胺建立肝纤维化动物模型,在肝纤维化不同阶段,超声检测胆囊壁厚度及穿刺门静脉测量肝纤维化不同阶段门静脉压力。结果家兔肝纤维化阶段时胆囊壁增厚,同时门静脉内压力随着肝纤维化程度加重,呈逐渐升高趋势,且肝纤维化S2~S4期与S0期比较,差异有统计学意义(P<0.05),胆囊壁厚度与门静脉压力间具有显著正相关(P<0.01,r=0.799)。结论肝纤维化时胆囊壁厚度与门静脉压力有关。     

超声定量检测对乙肝患者肝纤维化的诊断价值

目的评价超声定量检测对乙肝患者肝纤维化的诊断价值。方法选取收治的112例慢性乙肝患者为研究对象,均接受超声定量检测,并与肝组织活检结果进行对比。结果 S3及S4期患者各检测指标均高于S0、S1期患者,差异有统计学意义(P0.05);超声定量检测对肝纤维化轻度准确性为94.87%,中度准确性为87.50%,早期肝硬化准确性82.60%。结论超声内镜检测具有准确性高、重复性好等优点,可作为评价肝纤维化程度的一种重要辅助检测手段。     

磁共振T1 mapping、T2 mapping与大鼠肝纤维化、肝脂肪变性的相关性分析

目的 探讨磁共振T1 mapping、T2 mapping与大鼠肝纤维化分期和肝脂肪变性程度之间的相互关系。方法 对53只大鼠肝纤维化模型进行MRI T1 mapping、T2 mapping成像,测量肝实质的T1值(ms)和T2值(ms),根据病理学结果将大鼠肝纤维化划分为S0～S4期,将脂肪变性划分为F0～F4度,分别分析T1值、T2值与肝纤维化分期、肝脂肪变性程度之间的相关性。结果S0期与肝纤维化各期之间的T1值、T2值的差异具有统计学意义(p<0.05),S1期与S3期、S1期与S4期、S2期与S4期T1值以及S1期与S4期T2值的差异具有统计学意义(p<0.05),而其他两两比较均不具有统计学意义(p>0.05)。T1值与肝纤维化程度呈正相关(r=0.683,p<0.01),而T1值与脂肪变性程度无相关性(p>0.05),T2值与脂肪变性程度有显著相关性(r=0.716,p<0.01),而与肝纤维化程度则无相关性 (p>0.05)。结论 磁共振T1 mapping可以用于评估肝纤维化分期,T2 mapping则可以用于评估肝脂肪变性程度。     

肝脏瞬时弹性超声诊断 ALT 小于2倍正常上限慢性HBV 感染者肝纤维化的影响因素分析

目的探讨肝脏瞬时弹性超声(Fibroscan)对于丙氨酸氨基转移酶(ALT)小于2倍正常值上限(upper limits of normal,ULN)的慢性乙型肝炎病毒(HBV)感染者肝纤维化的诊断价值,并分析影响因素。方法 125例ALT<2 ULN的慢性HBV感染者,采用肝脏瞬时弹性超声测定不同肝脏纤维化分期组间以及不同炎症分级组间患者肝脏硬度值(liver stiffness measurement,LSM),并进一步探讨年龄、性别、BMI、血清ALT、AST、TBIL、ALB、HBV-DNA与LSM值的相关性。结果 125例患者肝组织的纤维化分期在S0~S3期,炎症分级在G1~G3期。不同分期组间LSM值比较差异有统计学意义(P<0.05),但S0组和S1组比较差异无统计学意义;不同分级组间LSM值比较差异有统计学意义(P<0.05)。经Spearman相关分析结果显示,患者的年龄、血清ALT及AST水平与LSM值呈正相关(P<0.05)。男性患者的LSM值明显高于女性患者。结论 Fibroscan对于ALT<2 ULN的慢性HBV感染者肝纤维化的无创诊断同样具有较好适用性。对于这部分人群,患者的性别、年龄、肝脏炎症程度,以及血清ALT、AST水平,是可能的Fibroscan测值影响因素。     

超声造影与剪切波弹性成像评估慢性乙型肝炎肝纤维化的对比研究

目的探讨超声造影与剪切波弹性成像(SWE)在慢性乙型肝炎(CHB)肝纤维化评估中的应用价值。方法选取我院行肝穿刺活检的CHB患者120例,根据活检结果分为无纤维化组(S0期)18例、肝纤维化组(S1~S3期)73例、肝硬化组(S4期)29例。应用超声造影获取各组肝动静脉渡越时间(HAVTT1和HAVTT2)值,SWE检查获得肝脏弹性测值;应用受试者工作特征(ROC)曲线分析各检测指标预测肝纤维化及肝硬化的诊断效能。结果随着肝纤维化分期提高,HAVTT1、HAVTT2逐渐缩短,肝脏弹性测值逐渐增大;HAVTT1、HAVTT2及肝脏弹性测值在无纤维化组、肝纤维化组及肝硬化组之间两两比较差异均有统计学意义(均P<0.05)。ROC曲线分析显示,HAVTT1、HAVTT2诊断肝纤维化及肝硬化的曲线下面积分别为0.870、0.851和0.889、0.856,肝脏弹性测值诊断肝纤维化及肝硬化的曲线下面积为分别为0.953、0.898;肝脏弹性测值的诊断效能明显优于HAVTT1及HAVTT2,差异均有统计学意义(均P<0.05)。结论应用SWE技术获取的肝脏弹性值对CHB患者肝纤维化及肝硬化的诊断优于超声造影。     

实时二维剪切波弹性成像技术无创评价肝纤维化与病理分期的相关性研究

目的探讨实时二维剪切波弹性成像(shearwaveelastography,SWE)技术无创评价慢性乙型肝炎患者肝纤维化程度的诊断价值。方法对213例(病例组)慢性乙肝感染患者进行经皮肝脏穿刺活检术病理组织学检查,分为S0-S4期。选取同期健康体检人群40例(对照组)。采用SWE技术对上述人群肝脏进行肝脏弹性检测,将获取的5次肝脏弹性值(LSM,liver stiffness of measurement)作为SWE指标,与肝穿刺活检病理结果进行对照分析。结果1、S0与对照组差异无统计学意义,余病例各组与对照组有统计学差异(P<0.05)。2、分析结果显示不同纤维化分期之间,S0与S1、S3与S4无统计学差异,余各组间均有统计学差异(P <0.05)。3、病例组LSM与肝纤维化分期呈正相关(Spearmanr=0.53,P<0.05)。4、根据各期LSM测量值,ROC曲线下面积分别为0.822、0.814、0.843、0.814;阈值分别为9.56、 9.64、 11.64、 13.43。结论SWE技术可以较好地区分慢性慢乙型肝炎肝纤维化程度,能够为临床治疗及疗效评定提供重要依据。     

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.