超声背向散射积分技术评价兔急性肾衰竭的实验研究

目的 :探讨背向散射积分技术对急性肾衰竭的应用价值。方法 :正常组 :2 0只家兔 4 0个肾进行超声检查。肾衰组 :12只家兔 2 4个肾 ,每日肌肉注射庆大霉素 14 0 mg/ kg,连续 7天 ,第 8天对 2 4个肾衰肾进行超声检查。分别比较正常兔肾和肾衰兔肾皮质、髓质、肾窦三者之间的背向散射积分 (IBS)测定值 ,比较正常组和肾衰组 IBS测定值及其标化值的改变情况。结果 :正常组和肾衰组肾脏的皮质、髓质、肾窦系统 IBS测定值三者之间差异有显著性意义 ,P<0 .0 0 1;正常组与肾衰组两组之间肾皮质和肾髓质的 IBS测定值及其标化值差异有显著性意义 ,P<0 .0 0 1,以皮质部 IBS参数改变明显 ,两组间肾窦系统的 IBS测定值无显著性差异 ,P>0 .0 5 ;体积与皮质厚度呈高度相关性。结论 :背向散射积分技术可以对正常肾和肾衰肾的皮质、髓质、肾窦不同组织结构状态实现量化描述。背向散射积分参数结合皮质厚度测量可以反映急性肾衰竭肾实质的病理形态学改变     

背向散射积分技术在检测移植肾慢性排异反应中的应用价值

目的应用背向散射积分技术检测移植肾脏疾病,并初步探讨背向散射积分技术在检测移植肾慢性排斥反应中的应用价值。方法将全部研究对象分为病例组和正常对照组,应用HP5500型超声诊断仪分别检测其肾脏的图像平均强度（AII）、图像峰-峰强度（PPI）,并计算标化的背向散射积分（IBS％）、标化的图像峰-峰强度（PPI％）,分别对各值进行分析比较。结果（1）病例组肾皮质IBS％值较正常对照组增高（P〈0．05）,PPI值、PPI％值较正常对照组增高,但无统计学意义。（2）病例组（②、③、④）随肾功能损害程度的加重,[肾皮质-肾髓质IBS％]值逐渐下降,与正常对照（①）组均存在差别,但均无统计学意义。结论（1）应用IBS技术可以实现超声对肾脏病变的定性、定量诊断。（2）IBS值可以反映移植肾脏慢性排异反应的声学改变。     

超声背向散射积分观察正常兔肾

目的应用超声背向散射积分技术定量评价正常兔肾的不同结构.方法 20只正常兔进行肾脏超声检查.测量正常兔肾不同结构区域的背向散射积分值,比较肾皮质、髓质、肾窦三者之间的背向散射积分测定值.结果正常兔肾脏皮质、髓质、肾窦系统IBS测定值三者之间差异有显著性意义(P＜0.001),与二维回声情况一致.结论超声背向散射积分可以对正常兔肾的皮质、髓质、肾窦不同组织结构实现量化描述.     

正常成人胰腺超声背向散射积分的测定

目的 测定正常成人胰腺背向散射积分（IBS）值，为进一步研究胰腺不同病变的IBS变化提供正常参考值。 方法 对120例正常成人胰腺进行IBS联机分析测定，将受试者分为2个年龄组：Ⅰ组〈50岁；Ⅱ组≥50岁，分别检测每位受检者胰头、胰体、胰尾的IBS值，以其所在深度时间增益补偿（TGC）均值对实测IBS值进行标化。 结果 正常成人胰腺头、体、尾的标化IBS值比较差异无显著性意义（P〉0．05）；不同性别组胰腺标化1BS值比较差异无显著性意义（p〉0．05）；不同年龄组胰腺的标化IBS值比较差异有显著性意义（p〈0．05）。 结论 正常成人胰腺的的标化IBS值稳定，可重复性好，超声背向散射积分为无创判定胰腺组织的微细变化提供了新的技术手段。     

超声背向散射积分技术在2型糖尿病胰腺检测中的应用价值

目的 探讨超声背向散射积分（IBS）技术在糖尿病胰腺检测中的临床应用价值。 方法 对110例2型糖尿病患者及120例正常成人胰腺进行IBS联机分析测定。结果 2型糖尿病组胰腺的标化IBS值明显高于正常对照组（P〈0.05）；2型糖尿病不同病程组胰腺标化IBS值比较差异有显著性意义（P〈0.05）；2型糖尿病不同治疗组胰腺标化IBS值比较差异有显著性意义（P〈0.05）；2型糖尿病胰腺标化IBS值与血清C肽水平呈负相关。 结论 IBS值能客观、准确地反映出2型糖尿病胰腺组织的病理改变情况，为临床检测糖尿病胰腺提供了一项数字定量化、标准化的新指标。     

超声背向散射积分评价肾脏纤维化的临床研究

目的 用超声背向散射积分（IBS）技术来评价肾脏纤维化的程度。方法 将临床确诊并经肾穿刺活检病理证实的肾脏弥漫性疾病患者分为尿毒症期（I），氮质血症期（Ⅱ）和肾功能不全代偿期（Ⅲ）三组，以正常人为对照组（Ⅳ），测量肾实质及肾窦区IBS值，以二者之比为肾实质标化IBS值（IBS%）。结果 随着肾脏纤维化程度的加重其IBS%值升高。结论 背向散射积分为无创判定肾脏组织的纤维化程度提供了一种新的技术手段。     

超声组织定征技术在糖尿病视网膜病变中的应用

目的 探讨利用背向散射积分技术检查糖尿病患者的视网膜背向散射积分值（IBS），以期为临床诊断糖尿病视网膜病变提供有效的方法。 方法 糖尿病患者78例（150只眼），正常对照组90例（180只眼），分别测量每位受检者的鼻侧、中部及颞侧的视网膜IBS值。 结果 视网膜鼻侧、中部及颞侧的IBS校正值（IBSG）间无统计学差异；糖尿病组视网膜的IBS值高于对照组，两组间有显著的统计学差异（P〈0．01）；糖尿病组视网膜的校正IBS值（IBS％）高于对照组，两组间有非常显著的统计学差异（P〈0.01）。 结论 糖尿病患者视网膜的IBSG明显高于对照组；背向散射积分技术是评价糖尿病视网膜病变的有效手段。     

声学密度定量分析颈动脉粥样硬化的初步研究

目的：应用背向散射积分评价颈动脉粥样硬化，分析不同超声特征斑块的IBS值和IBS标化值(IBS％)，反映其病理成分。方法：应用背向散射积分检测91例患者172块颈动脉斑块的IBS值与外膜IBS值的百分比，作为标化值IBS坏。结果：硬斑，扁平斑，软斑，溃疡斑之间均有显著差异(P＜0．05）。结论：背向散射积分技术能够反映斑块的不同病理成分，为临床提供一个客观标准。     

不同剂量有机磷中毒兔肝脏背向散射积分的测定

目的探讨背向散射积分技术描述不同剂量有机磷中毒兔肝脏改变的价值。方法建立兔有机磷中毒动物模型，分别于染毒后1、3h对4个不同剂量实验组及对照组行二维超声及背向散射积分（integrated backscatter，IBS）检查。二维超声观察肝脏的回声，测量肝右叶前后径，IBS定量分析肝脏改变。结果各剂量组染毒后1、3h肝脏回声与对照组相比未见明显改变，肝右叶前后径于染毒后1、3h与对照组相比差异均无统计学意义（P均〉0．05）。染毒1h组4远场标化肝脏背向散射积分（IBS％）与组0相比差异有显著性意义（P〈0．05）。染毒3h组3、4近、中、远场IBS％与组0相比差异均有显著性意义（P均〈0．05）。结论不同染毒剂量有机磷类化合物中毒兔肝脏背向散射积分改变可以为诊断有机磷中毒肝损害提供依据。     

超声背向散射积分对2型糖尿病早期肾病的定量评价

目的应用超声背向散射积分（IBS）技术定量评价2型糖尿病肾病（DN）早期肾脏微观组织结构的变化。方法2型糖尿病（DM）患者按照尿微量白蛋白分为两组，正常蛋白尿阶段Ⅰ组、微量蛋白尿阶段Ⅱ组及正常对照组，各30例，对肾皮质、肾髓质、肾窦IBS3项参数[峰值（PPI）、平均值（AII）、离散度（SDI）]进行测定及对比分析。采用肾窦AII对肾皮质和肾髓质的AII进行标准化。结果（1）肾皮质及肾髓质标化AII，对照组〈Ⅰ组〈Ⅱ组，三组差异显著（P〈0．05）；（2）DM组及对照组AII均为肾窦〉肾皮质〉肾髓质，三者差异显著（P〈0．05）；（3）肾皮质、肾髓质、肾窦PPI、SDI，三组间无统计学差异（P〈0．05）。结论2型糖尿病早期肾病患者的肾皮质与肾髓质声学密度随着病情的进展有逐渐增高的趋势，IBS技术有助于DN的早期发现和定量分析。     

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.