肾小球滤过率的估算及其临床应用

目的评估肾脏病改变饮食试验（MDRD）方程在中国糖尿病人群中的临床适用性。方法使用^99mTc-DTPA直接检测463例（女219例，男244例，年龄14—88岁）中国糖尿病人群的肾小球滤过率（GFR），并检测其血清肌酐（Scr）及半胱氨酸蛋白酶抑制剂（Cys C）浓度。以MDRD方程为基础与直接检测GFR比较，评估其在中国糖尿病人群中适用性，估算人种调整系数并与MDRD方程、国内改良MDRD方程比较；了解Scr及Sys C方法学因素对于估算GFR的影响；尝试建立以Cys C为基础的GFR估算公式；比较Scr及Cys C的临床适用性。结果Scr及Cys C检测值倒数与放射性核素测量GFR检测值呈线性关系（r=0．69；r=0．83）；Scr估算方程为GFR[ml·（min·1．73m^2）^-1]=175×（Scr）^-1.154×（age）^-0.203×0．742（女性）×0．827（0．827为中国人群的人种系数）。含此系数的MDRD公式估算GFR的临床诊断性能曲线（ROC曲线）下面积0．818，优于文献报道的MDRD方程（0．644）及国内改良MDRD方程（0．709）。散射法检测Cys C估算方程为GFR[ml·（min·1．73m^2）^-1]=63．24×（Cys C）^-0.3378；透射法检测Sys C估算方程为GFR[ml·（min·1．73m^2）^-1]=59．02×（Cys C）^-0.3880。使用Cys C估算GFR在60岁以上人群优于Scr估算的GFR（ROC曲线下面积0．722与0．583）。方法学差异影响GFR估算，罗氏酶法Scr检测试剂结果可溯源至同位素稀释质谱法（IDMS），明显低于苦味酸法Scr检测（Y=0．94X-0．02）。如使用未溯源至IDMS的苦味酸法Scr试剂，应将方法学系数调整为186。结论临床实验室报告估算GFR值，可使用Scr或Cys C抑制剂。使用Scr估算GFR应使用可溯源至IDMS的肌酐检测结果，并考虑人种因素。     

血清胱抑素C和MDRD方程在慢性肾脏病诊断中的临床应用

目的探讨血清胱抑素-C（Cys—C）在诊断慢性肾脏病（CKD）的意义,以及Cys-C与MDRD方程估计肾小球滤过率（GFR）的准确性及相关性。方法根据MDRD方程7计算的肾小球滤过率（GFR）将CKD患者分为5期,ELISA法检测CKD患者的Cys—C的水平,观察Cys—C与血肌酐（Scr）、GFR的相关性。结果Cys—C与Scr呈正相关,与GFR呈负相关;在肾功能轻度损伤时,Cys-C反映肾功能恶化程度的敏感度较Scr高。结论ELISA法能够检测Cys—C的水平,Cys—C能够作为反映肾功能的可靠指标,并且是肾功能的早期诊断指标。CKD2-5期,Cys—C与MDRD方程7有良好的相关性;Cys-C与MDRD方程7能够作为CKD2-5期患者估计GFR的指标。     

血清肌酐和半胱氨酸蛋白酶抑制剂C及估算的肾小球滤过率在评价慢性肾病患者肾小球滤过功能中的比较研究

目的比较血清肌酐（Scr）、肌酐清除率（Ccr）、半胱氨酸蛋白酶抑制剂C（CystatinC）及估算的肾小球滤过率（eGFR）在慢性肾病（CKD）患者各期中的符合率。方法Scr和尿肌酐采用苦味酸动力学法测定，血清CystatinC采用颗粒增强免疫散射比浊法测定，主要基于Scr估计的eC．FR采用简化的肾病膳食改良试验（MDRD）方程进行计算，CKD患者根据1999年美国肾病基金会（NKF）公布的“改善肾病预后及生活质量的倡议”（KidneyDiseaseOutcomeQualityInitiative，K／DOQI）所制定的指南，按照eGFR分为5期。结果228例CKD患者，各期Scr、CystatinC随eGFR的降低而逐渐升高，Ccr随eGFR的降低而逐渐降低，三者在各期间水平的差异均有统计学意义（P〈0．05）。当eGFR≤29ml／min时，Scr、Ccr及CystatinC的异常率均为100％，Scr、CystatinC平均水平是正常参考值上限的4—6倍和3．5—5．5倍，Ccr下降3．8—7．3倍，三者呈平行性改变；在eGFR30—59ml／min组，Scr、Ccr和CystatinC的平均水平分别为129．2μmol／L、44．3ml／min和2．16mg／L，异常率分别为84％、91％和98％，三者间异常率的差异无统计学意义（P〉0．05）；在eGFR60—89ml／min组，血清肌酐的平均水平为83．3μmol／L，异常率仅为6．8％，对于GFR下降的检出不敏感，Ccr、CystatinC分别呈边缘性下降和上升，异常率为70％和86％，三者问异常率的差异有统计学意义（P〈0．05）；在eGFR≥90ml／min组，血清肌酐的异常率为0，Ccr、CystatinC的异常率仍高达44％和59％。结论eGFR〈60ml／min时，与Scr、Ccr及CystatinC的总符合率高，此时可以基本诊断肾小球滤过功能中度下降；60ml／min≤eGFR≤89ml／min时，Scr不能反映肾脏滤过功能的下降，但CystatinC和Ccr至少能检出2／3患者GFR的异常，CystatinC较Ccr更敏感；在eGFR≥90ml／min时，MDRD方程高估了实际GFR，对于Scr水平正常，特别是老年CKD患者，MDRD方程不适用，需联合检测Ccr和CystatinC，以及时发现GFR的下降。     

肾小球滤过率评估方程在糖尿病患者中的应用

目的 评估美国慢性肾脏病流行病学协作组（CKD-EPI）系列方程及修正方程预测糖尿病患者肾小球滤过率（GFR）的效能,包括CKD-EPI肌酐（Scr）方程（CKD-EPI_scr）、CKD-EPI半胱氨酸蛋白酶抑制剂C（SCysC）方程（CKD-EPI_scysc）、CKD-EPI Scr和SCysC混合方程（CKD-EPI_Scr-SCysC）、亚洲CKD-EPI方程（CKD-EPI_亚洲）、中国糖尿病CKD-EPI方程（CKD-EPI_糖尿病）及改良肾脏病膳食改良实验（MDRD）、Cockcroft-Gault（CG）方程、简化MDRD方程。方法 采用碱性苦味酸法测定血清Scr,胶乳增强免疫透射比浊法测定血清ScysC,^99mTc-DTPA肾动态显像法测定GFR,并经体表面积标准化后获得rGFR。分析Scr、ScysC、各方程计算获得GFR（eGFR）与rGFR的相关性,并比较各方程的30%符合率、各方程eGFR与rGFR的偏差和偏离程度及一致性。以rGFR<60 ml/（min·1.73 m²）为诊断肾功能不全的标准,采用ROC曲线分析各公式eGFR诊断肾功能不全的效能。结果 Scr、Scys与rGFR呈负相关（P均<0.001）;各方程CKD-EPI_Scr、CKD-EPI_ScysC、CKD-EPI_Scr-SCysC、CKD-EPI_亚洲、CKD-EPI_糖尿病、改良MDRD、CG、简化MDRD测量的eGFR与rGFR均呈正相关（P均<0.001）。CKD-EPI_糖尿病、简化MDRD测量的eGFR与rGFR30%符合率较高;CKD-EPI_Scr、CKD-EPI_亚洲、CKD-EPI_糖尿病、改良MDRD测得的eGFR与rGFR差异无统计学意义（P均>0.05）;CKD-EPI_糖尿病测量的eGFR与rGFR一致性最好,其余所有公式一致性均超过预定的界限。ROC曲线示CKD-EPI_糖尿病测量的eGFR曲线下面积最大、Youden指数最高。结论 8种公式预测的eGFR均存在不同程度偏差,中国2型糖尿病方程CKD-EPI准确率和一致性最佳。     

血肌酐、胱抑素C、简化MDRD和LeBricon公式在评估肾移植术后肾功能中的作用

目的：探讨血肌酐（Scr）,胱抑素C（Cys C）,简化MDRD和Le Bricon公式在评估患者肾移植术后肾功能中的诊断价值。方法收集2012年9月～2014年6月间57例肾移植患者和48例健康对照组采用99m Tc-DTPA肾动态显像法（RDI）测定肾小球滤过率（GFR）,检测 Scr和Cys C,利用简化 MDRD和 Le Bricon 公式计算 GFR估算值,进行 spearman相关性分析,并用受试者工作特征曲线（ROC）评价诊断价值。结果肾移植组 DTPA,Scr,Cys C,简化 MDRD和 Le Bri-con估算值分别为60.69±13.52 ml/min/1.73m2,1.34±0.28 mg/dl,1.42±0.15 mg/dl,66.97±15.85 ml/min/1.73m2和59.93±10.23 ml/min/1.73m2;对照组值分别为90.12±12.61 ml/min/1.73m2,0.97±0.09 mg/dl,0.86±0.12 mg/dl,87.13±18.29 ml/min/1.73m2和94.80±18.73 ml/min/1.73m2,组间比较均有统计学意义（t＝1.01～6.12,P 值均＜0.01）,Scr,Cys C,简化 MDRD和 Le Bricon估算值与DTPA之间具有不同的相关性（r＝-0.76～0.82,P 值均＜0.01）, ROC曲线下面积分别为0.856,0.973,0.814和0.971。结论 Scr,Cys C,MDRD和 Le Bricon均对肾移植后受体患者慢性肾病有一定的预测价值,但 Cys C及基于 Cys C的 Le Bricon评估方程分别优于肌酐及基于肌酐的简化 MDRD评估方程。     

血清半胱氨酸蛋白酶抑制剂C在肾移植功能监测中的应用价值

目的探讨血清半胱氨酸蛋白酶抑制剂C（Cys C）在肾移植术后，尤其是感染和排斥时，监测肾功能的临床应用价值。方法同时检测65例肾移植患者术前、术后1个月内、感染或排斥发生时及次日血清中Cys C和血清肌酐（Scr）的浓度，并测定30名健康人和30例非移植感染患者的Cys C和Scr作为对照。结果健康人与非肾移植感染患者的Cys C浓度差异无统计学意义（P=0．32）。移植后肾功能稳定组（n=36）术后前3d内Cys C分别较术前下降了69．2％、74．7％、75．8％（P〈0．01），Scr相应的下降了38．4％、74．5％、81．4％（P〈0．01）。移植术后感染组（n=13）肾功能异常时，Cys C比Scr早（4．4±1．5）d升高，升高幅度分别为39．4％和35．3％（P=0．43）；排斥组（n=16）Cys C比Scr早（2．7±1．8）d升高，升高幅度分别为148．9％和43．9％（P=0．0069）。与肾功能稳定组作横向比较，术后感染组和排斥组的Cys C分别升高了38．7％和108．5％（P〈0．001），Scr分别升高了34．2％和89．5％（P〈0．001）。所有肾移植患者术后3～28d之间，Cys C与Scr呈线性正相关（r=0．785，P〈0．0001）。根据ROC曲线确定Cys C和Scr在术后排斥时的临界值分别为1．79mg／L和122μmol／L。排斥组Cys C的敏感度、特异度、阳性预测值、阴性预测值、符合率以及曲线下面积（AUC）均优于Scr（均P〈0．05）。结论Cys C优于Scr，是一个能早期、灵敏、准确判断移植肾功能变化的血清标志物。     

血清胱抑素C检测对肝肾综合征的诊断价值

目的探讨血清胱抑素C(Cys C)检测对肝肾综合征(HRS)的诊断价值。方法以24 h肌酐清除率(24 h-Ccr)为肾小球滤过率(GFR)标准,将63例晚期肝硬化患者分为两组:GFR<40 ml/min为HRS组,GFR≥40 ml/min为非HRS组。分别测定血清Cys C、血肌酐(Scr),并由MDRD(Modification of Diet in Renal Disease)公式估计肌酐清除率;结果Cys C、MDRD在HRS组与非HRS组(P均<0.01),Scr在HRS和非HRS组间无显著差异(P>0.05)。相关分析显示,Cys C与GFR的相关性最好(r=-0.628,P<0.01),Scr、MDRD与GFR无明显相关(r=-0.355,P>0.05;r=0.059,P>0.775)。ROC曲线表明,Cys C、Scr、MDRD中Cys C的诊断效率最高;结论Cys C是HRS患者良好的GFR标志物,其诊断HRS的能力优于Scr和MDRD。     

胱抑素C测定评价慢性肾脏病肾小球滤过率的临床应用

目的测定慢性肾脏病(CKD)患者血胱抑素C(Cys C)水平及血肌酐水平,比较血Cys C与血肌酐清除率的相关性,寻求1种理想的反映肾小球滤过率(GFR)的敏感指标。方法以75例CKD患者为研究对象,其中男32例,女43例;分别测定其血肌酐、血Cys C水平,并利用Cockcroft-Gault公式及MDRD公式将血肌酐水平换算成血肌酐清除率。其中,22例患者以~(99m)TC-二乙三胺五醋酸肾动态显像检测GFR。结果 CKD 5期肾小球滤过率的下降速度低于Scr值的增长;Cys C与GFR相关性优于Scr(-0.717 vs -0.631)。结论 Cys C是1项理想反映GFR的内源性指标与Scr进行联合检测,并结合CG、MDRD公式,能有效地评价GFR。     

改良MDRD公式、血清肌酐、肌酐清除率、胱抑素C及尿微量白蛋白在慢性肾病早期诊断中的应用

目的采用估算的肾小球滤过率（eGFR）在慢性肾病（CKD）患者中分期,用于比较各期血清肌酐（Scr）、肌酐清除率（Ccr）、胱抑素C（CystatinC）及尿微量白蛋白（mAlb）的异常率,分析该五项指标在慢性肾病早期诊断中的应用。方法Scr和尿肌酐采用苦味酸动力学法测定,血清Cystatinc采用胶乳增强免疫比浊法,尿mAlb采用速率散射比浊法,eGFR主要基于Scr及年龄而采用简化的肾病膳食改良试验（MDRD）方程进行计算。结果CKD患者随着eGFR的降低,Nor、Ccr、CystatinC三指标平均水平在各期间的差异有统计学意义（P〈0．05）。而尿mAlb在各期内离散度很大,各水平间差异无统计学意义（P〉0．05）。当eGFR≥90mL／min时,Ccr、CystatinC、尿mAlb与Scr的异常率分别为18．42％、22．37％、25．0％、0,前三者与Scr比较差异均有统计学意义（P〈0．05）,而三者间异常率比较差异无统计学意义（P〉0．05）;当eGFR在60-89mL／min时,异常率分别为28．89％、46．67％、22．22％、2。22％,前三者与Scr比较差异同样有统计学意义（P〈0．05）;当eGFR在30～59mL／min时,异常率分别为90．48％、76．19％、57．14％、52．38％,Ccr及CystatinC异常率与Scr比较差异有统计学意义（P〈0．05）,Ccr异常率最为显著;在eGFR≤29mL／min时,Scr、Ccr、CystatinC、尿mAlb四项指标的异常率均为100％。结论当eGFR〉60mL／min,Scr不能反映GFR的下降,eGFR高估了实际的GFR,而应增加CystatinC和Ccr来评价肾脏功能;当eGFR在30-59mL／min,Scr、CystatmC、Ccr及mAlb能检出一半以上的病例异常,其中CystatinC及Ccr能检出3／4GFR下降的病例,因此对于此期Scr正常,应增加CystatinC和Ccr检验来评价肾脏功能,必要时应检测^99mTc—DTPA清除率来检测GFR值;当eGFR％29mL／min,各指标都反映肾脏功能受损。对于出现尿mAlb的患者,说明肾脏早期受到损伤,24h尿mAlb量的多少不反映GFR的降低,应增加Cysta—tinC、Ccr及eGFR来判断CKD分期,必要时应检测^99mTc-DTPA清除率来检测GFR值。     

Cys C及其GFR评估方程在糖尿病肾病诊断中的应用

目的探讨半胱氨酸蛋白酶抑制剂C(Cys C)及其肾小球滤过率(GFR)评估方程(Grubb公式)在糖尿病肾病(DN)及其分期中的应用。方法选取糖尿病(DM)患者184例,检测患者血清Cys C、Cr、Urea、Alb及24 h尿微量白蛋白(mAlb)。通过MDRD方程、简化MDRD方程、C-G方程及Cys C方程评估入选患者预测GFR(eGFR),并进行比较。结果早期DN组患者血清Cys C为1.17(0.97,1.44)mg/L,与单纯DM组[1.04(0.89,1.22)mg/L]比较,Z=-6.54,P<0.05;与临床DN组[1.85(1.30～2.75)mg/L]比较,Z=-3.90,P<0.01。Cys C方程、MDRD方程、简化MDRD方程、C-G方程的eGFR值早期DN组与临床DN组比较,差异均有统计学意义(P<0.01);单纯DM组与早期DN组比较,仅Cys C方程的eGFR值,差异有统计学意义(P<0.05)。在CKDⅠ期、Ⅱ期,Cys C方程eGFR值显著低于MDRD方程、简化MDRD方程和C-G方程(P<0.01);在CKDⅢ～Ⅴ期,Cys C方程eGFR值与MDRD方程差异无统计学意义(P>0.05),但显著低于简化MDRD方程、C-G方程(P<0.01)。结论 Cys C及其评估方程可能提高DN的检出率,在评估CKDⅢ～Ⅴ期DN患者GFR时可能优于简化MDRD方程和C-G方程,在CKDⅠ期、Ⅱ期DN患者中存在低估现象。     

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.