载脂蛋白E基因敲除小鼠早期动脉粥样硬化超声生物显微镜成像与组织病理的对照分析

目的利用超声生物显微镜(UBM)成像分析载脂蛋白E基因敲除(ApoE-/-)小鼠主动脉早期动脉粥样硬化的超声特征。方法以8周及16周龄雄性ApoE-/-小鼠各8只为实验组,8周及16周龄雄性C57BL/6小鼠为对照组,用UBM观察小鼠主动脉根部、升主动脉和主动脉弓的形态结构,并于主动脉根部短轴切面测量内-中膜厚度(IMT),与相对应血管节段的病理组织学测值进行对比。结果 ApoE-/-小鼠的主动脉根部IMT较同周龄对照组增厚(P<0.01);16周龄ApoE-/-小鼠较8周龄ApoE-/-小鼠主动脉根部IMT增厚更为明显(P<0.01)。采用UBM所测IMT与病理测值呈高度正相关(r=0.81,P<0.0001)。结论采用UBM成像可准确测量小鼠主动脉IMT,观测ApoE-/-小鼠升主动脉早期动脉粥样硬化的病变特征。     

超声生物显微镜成像对载脂蛋白E基因敲除小鼠早期动脉粥样硬化的分析

目的 利用超声生物显微镜（UBM）成像分析载脂蛋白E基因敲除（ApoE-/-）小鼠主动脉早期动脉粥样硬化（AS）的超声特征.方法 8周龄和16周龄雄性ApoE-/-小鼠各8只为实验组,同周龄的雄性C57BL/6小鼠各8只为对照组.使用UBM观察小鼠主动脉根部、升主动脉和主动脉弓的形态结构,并于主动脉根部短轴切面测量内-中膜厚度（IMT）.检查后处死小鼠取标本,行病理学检查.结果 ApoE-/-小鼠的主动脉根部IMT较同周龄对照组增厚,差异有统计学意义（P〈0.01）;16周龄ApoE-/-小鼠较8周龄ApoE-/-小鼠主动脉根部IMT增厚更为明显,差异有统计学意义（P〈0.01）.形态学病理检查显示6只16周龄ApoE-/-小鼠主动脉根部、升主动脉小弯侧及无名动脉可见局部管壁增厚,有散在白色脂纹形成.结论 UBM成像可无创观察活体ApoE-/-小鼠升主动脉早期AS的病变特征,能有效监测ApoE-/-小鼠AS病变的进程.     

超声生物显微镜评价高脂饮食促进载脂蛋白E基因敲除小鼠动脉粥样硬化

目的 探讨应用超声生物显微镜(UBM)评价高脂饮食下载脂蛋白E(ApoE)基因敲除小鼠动脉粥样硬化的价值.方法 将32只8周龄ApoE基因敲除小鼠分为两组,一组饲以高脂饲料为高脂组,另一组饲以常规饲料作为对照组.饲养8周和16周后,采用Vevo 770超声成像系统观察两组小鼠升主动脉内-中膜厚度(IMT)及动脉粥样硬化斑块面积,并与病理组织学结果和血脂水平进行比较.结果 UBM显示高脂组和对照组小鼠主动脉根部管壁均增厚,出现粥样硬化斑块,但高脂组IMT及斑块面积均较对照组小鼠高,差异具有统计学意义(P＜0.05).UBM所测IMT及斑块面积与病理结果相关性良好(r分别为0.81和0.70);高脂组小鼠血清甘油三酯(TC)及总胆固醇(TG)水平均较对照组升高(P＜0.05),UBM所测IMT随TC水平升高而增加,两者呈正相关(r=0.528).结论 高脂饮食可促进ApoE基敲除小鼠主动脉粥样硬化斑块形成,超声生物显微镜能作为无创性观测手段来评价活体小鼠的动脉粥样硬化改变.     

ApoE基因敲除小鼠动脉粥样硬化早期血脂变化及主动脉超声生物显微镜成像分析

目的 分析ApoE基因敲除(ApoE-/-)小鼠血脂变化及主动脉动脉粥样硬化的超声生物显微镜(UBM)成像特征.方法 8周龄及16周龄雄性ApoE-/-小鼠各8只为实验组,同周龄同数量的雄性C57BL/6小鼠为对照组.应用超声生物显微镜观察小鼠主动脉根部、升主动脉和主动脉弓的形态结构,于主动脉根部短轴切面测量内-中膜厚度(IMT),并测定小鼠血脂.结果 ApoE-/-小鼠血清总胆固醇(total cholesterol,TC)、甘油三酯(triglyceride,TG)及低密度脂蛋白(low density lipoprotein,LDL)水平较同周龄对照组明显升高(P＜0.01);高密度脂蛋白(high density lipoprotein,HDL)水平较同周龄对照组减低(P＜0.05).16周龄ApoE-/-小鼠血脂较8周龄ApoE-/-小鼠增高更为明显,差异有统计学意义(P＜0.01).ApoE-/-小鼠的主动脉根部IMT较同周龄对照组增厚,差异有统计学意义(P＜0.01); 16周龄ApoE-/-小鼠IMT (0.208±0.038) mm较8周龄ApoE-/-小鼠主动脉根部IMT (0.121±0.025) mm增厚更为明显,差异有统计学意义(P＜0.01).结论 ApoE-/-小鼠早期出现高脂血症,UBM成像可显示小鼠主动脉早期动脉粥样硬化的病变特征.     

金黄地鼠胰腺癌动物模型的建立

研究背景 动脉粥样硬化(AS)是目前国内外广为关注的疾病,病因学研究方面还没有突破性进展,炎症在动脉粥样硬化形成和发展过程中起着非常重要的作用。白细胞介素1(IL-1)和白细胞介素6(IL-6)是非常重要的致炎症细胞因子,IL-1受体拮抗剂(IL-1Ra)在体内外实验中都能抑制IL-1的作用。而IL-6可能在动脉粥样硬化进程中表现为双相作用:促炎症作用和抗炎症作用。研究IL-1、IL-6在动脉粥样硬化中的作用有非常重要的意义。目的 探讨超声生物显微镜(UBM)在监测ApoE基因敲除小鼠动脉粥样硬化进程中的作用及动脉粥样硬化病变与IL-1和IL-6的关系。方法 使用高分辨力超声影像系统(UBMsystem,Vevo600,VisualSonics,Toronto,Canada),探头频率30~40MHz。实验组:4组不同周龄(8周、16周、24周和32周,每组8只)的雄性ApoE-/-小鼠。对照组:4组(8周、16周、24周和32周,每组8只)与实验组同龄同性别的雄性C57BL/6J小鼠。应用UBM 追踪观察各周龄实验组及对照组小鼠主动脉根部内-中膜厚度(IMT)。采用双抗夹心ELISA法测定血清IL-1、IL-6水平。结果 ①UBM 显示ApoE-/-组主动脉根部IMT 厚度随着周龄增长而增长,各周龄ApoE-/-小鼠IMT厚度组间差异有统计学意义(P<0.01)。对照组小鼠各周龄IMT差异无统计学意义。②UBM 测量的各周龄ApoE-/-小鼠主动脉根部收缩期最大IMT值和对应血管部位横切面病理测值有明显相关性(r=0.81,P<0.0001)。③ApoE-/-小鼠血清IL-1和IL-6水平较同周龄对照组升高(P<0.05和P<0.01)。ApoE-/-小鼠UBM 测量的主动脉根部IMT值与血清IL-1、IL-6浓度无明显相关性。结论 ①UBM 可以监测ApoE-/-小鼠的动脉粥样硬化进程,IMT测量可作为判断和监测动脉粥样硬化病变的一个准确有效的指标。②血清炎症反应标志物IL-1、IL-6的增高与动脉粥样硬化有关,但与动脉粥样硬化病变的严重程度不相关。     

ApoE基因敲除小鼠动脉粥样硬化的超声生物显微镜与病理的对照分析

研究背景 动脉粥样硬化(AS)是目前被国内外学者广为关注的疾病,AS的机制复杂,有多种细胞、炎性因子参与AS病变的发生和演变。C反应蛋白(CRP)是一种由肝脏合成的急性时相反应蛋白,在炎症等应激反应时,血清CRP水平急剧升高。研究显示,在AS病程中,CRP可能是反映疾病演进的一个标志。因此,研究血清CRP水平与动脉粥样硬化病变的关系意义重大。目的 探讨超声生物显微镜(UBM)在监测ApoE基因敲除小鼠动脉粥样硬化进程中的作用及动脉粥样硬化病变与血清CRP的关系。方法 采用VisualSonics公司的高分辨力超声成像系统(UBMsystem,Vevo600,VisualSonics,Toronto,Canada),探头频率30~40MHz。实验组:4组不同周龄(8周、16周、24周和32周,每组8只)的雄性ApoE-/-小鼠。对照组:4组与实验组同龄、同性别且与实验组数量相同的C57BL/6J小鼠。应用UBM 追踪观察各周龄实验组及对照组小鼠主动脉根部内-中膜厚度(IMT)。采用双抗夹心ELISA 法测定血清CRP水平。结果 ①UBM 显示实验组ApoE-/-组小鼠主动脉根部IMT随着周龄增长而增长,各周龄ApoE-/-小鼠IMT组间差异有统计学意义(P<0.01)。对照组各周龄C57BL/6J小鼠IMT差异无统计学意义。②UBM 测量的各周龄ApoE-/-小鼠主动脉根部收缩期最大IMT值与对应部位血管横切面病理测值有明显的相关性(r=0.81,P<0.001)。③ApoE-/-小鼠血清CRP水平较同周龄对照组小鼠升高(P<0.01),且随着周龄增长,血清CRP水平呈逐渐升高趋势。ApoE-/-小鼠血清CRP水平与UBM 测量的主动脉根部IMT值呈正相关(r=0.63,P<0.001)。结论 ①UBM 可以监测ApoE-/-小鼠的动脉粥样硬化进程,IMT 测量可作为判断和监测动脉粥样硬化病变的一个准确有效的指标。②血清炎症反应标志物CRP的增高与动脉粥样硬化有关。     

飞行员颈动脉内中膜的超声观察

目的早期发现飞行员颈动脉粥样硬化，及早进行干预治疗，预防心脑血管疾病的发生。方法高频超声检测150例飞行人员的颈动脉，测量颈总动脉后壁及分又处内中膜IMT，观察内中膜的厚度及斑块形成情况，同时选取100例健康体检人员作为对照组。结果飞行员颈动脉内中膜40岁以上异常检出率明显增加为24％（36／150），与对照组无明显差异。结论高频超声是无创诊断颈动脉早期动脉硬化的简便有效的方法。     

老年人颈动脉粥样硬化临床特点及相关危险因素分析

对来我院诊治的80例患者入院资料进行分析,患者入院后对其进行常规检查,实验中采用颈动脉多普勒对患者颈总动脉内中膜厚度(IMT)、斑块有无及性质、管腔狭窄程度等进行综合检测,分析老年人颈动脉粥样硬化的临床特点及其危险因素。结果 3例颈总动脉内中膜厚度(IMT)1.2mm,占3.75%;32例IMT在1.0mm-1.2mm,占40%,45例IMT1.0mm,占56.25%。19例颈动脉狭窄中,占23.75%。对患者行多因素Logistics回归分析可知,老年人颈动脉粥样硬化和年龄、合并糖尿病、合并高血压以及患者发病部分等均为其危险因素。老年人颈动脉粥样硬化发病率较高,并且患者颈动脉分叉、颈总动脉、颈内动脉等发病率较高,且患者发病后心血管疾病发病率明显上升。     

颈动脉粥样硬化与冠心病关系预测价值

目的利用体表高频超声检查研究颈动脉粥样硬化与冠状动脉粥样硬化关系的预测价值。方法对283例冠状动脉造影受检者行颈总动脉超声检查,测量其内中膜厚度、斑块厚度、计算斑块积分。并将其结果与冠状动脉造影及心血管危险因素进行单因素的t、χ^2检验。结果①颈动脉粥样硬化斑块、内中膜厚度（IMT）及斑块＋IMT对冠心病的阳性预测值分别为84．67％、81．39％及87．78％,三者对冠心病的特异性分别为71．60％、90．12％及95．06％;②冠状动脉造影阳性组的颈动脉内中膜厚度和粥样硬化斑块发生率明显高于阴性组,且随病变支数的增加,颈动脉内中膜厚度和斑块积分均增加（P〈0．05）;⑧冠心病组年龄、男性、高密度脂蛋白、血糖、血压水平方面显著高于对照组。结论颈动脉粥样硬化斑块、IMT可作为冠心病预测因子,两者联合应用,对冠心病的预测可提供更多信息。     

超声生物显微镜评价动脉粥样硬化小鼠模型的主动脉病变

目的 本实验以载脂蛋白E基因敲除(ApoE-/-)小鼠为模型,应用超声生物显微镜(UBM)对同龄的ApoE-/-小鼠及对照组进行主动脉二维及顺应性评价,探讨UBM在小鼠主动脉病变中的应用价值.方法 ApoE-/-小鼠和同龄正常同系对照C57BL/6小鼠进行UBM检查,观察主动脉内径变化及斑块形成情况,对比分析其顺应性指标.结果 比较对照组,ApoE-/-组小鼠主动脉内径、斑块数量均有增加,主动脉顺应性减低(P＞0.05).结论 UBM可清晰显示小鼠模型的主动脉并量化评价其病变程度,为心血管疾病动物研究提供有效手段.     

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.