丙氨酰谷氨酰胺对急性肺损伤患者的保护作用及其机制初探

目的 观察丙氨酰谷氨酰胺(Ala-Gln)对急性肺损伤(ALI)患者的保护作用及其机制.方法 110例ALI患者随机分为对照组(50例)和Ala-Gln组(60例).对照组给予常规治疗,Ala-Gln组在常规治疗的基础上,加用Ala-Gln,疗程7天,分别观察两组间治疗前后血清谷氨酰胺(Gln)、热休克蛋白70(HSP70)水平、急性生理学与慢性健康状况评分Ⅱ(APACHEⅡ)及机械通气时间的差异.结果 Ala-Gln组治疗后血清HSP70、Gln水平明显增高,与治疗前比较差异有统计学意义,HSP70 (1.99±0.66) μg/L vs (1.34±0.68) μg/L( P＜0.01);Gln (386.15±68.60)μg/L vs (304.72±73.70) μg/L(P＜0.01).与对照组治疗后比较差异亦有统计学意义,Gln (386.15±68.60) μg/L vs (303.74±78.08) μg/L( P＜0.01);HSP70 (1.99±0.66) μg/L vs(1.35±0.48)μg/L(P＜0.01).Ala-Gln组治疗前后Gln浓度比与HSP70浓度比呈明显正相关(r=0.809,P＜0.01),对照组治疗前后血清Gln、HSP70水平差异无统计学意义,对照组治疗前后Gln浓度比与HSP70浓度比无明显相关性(r=0.147,P＞0.05).Ala-Gln组机械通气时间明显低于对照组,(162.20±96.33)小时vs (235.00±107.90)小时(P＜0.05).治疗后APACHEⅡ评分的改善明显优于对照组,(8.40±2.17)分vs (11.10±2.42)分(P＜0.05).结论 Ala-Gln治疗可显著提高ALI患者血清Gln、HSP70水平、缩短机械通气时间,改善APACHEⅡ评分,提示Ala-Gln对ALI患者具有保护作用,其机制可能与提高患者体内Gln、HSP70水平有关.     

维持性血液透析患者脑内微出血与血清五聚素3水平相关性分析

目的 探讨维持性血液透析患者脑内微出血(cerebral microbleeds,CMBs)与血清五聚素3(pentraxin 3,PTX3)的关系。方法 95例维持性血液透析患者(透析组),根据头颅MRI检查结果分为CMBs组31例和非CMBs组64例,选择同期体检健康者30例为对照组。采用ELISA法测定各组血清PTX3水平,分析CMBs与PTX3水平的相关性。结果 透析组透析前血清PTX3为(1.75±0.69)μg/L,透析后为(2.58±0.95)μg/L,透析前、后血清PTX3比较差异有统计学意义(P<0.05),且均高于对照组((1.21±0.41)μg/L)(P<0.05);CMBs组血清PTX3((2.0±0.7)μg/L)高于非CMBs组((1.5±0.6)μg/L);Spearman相关分析显示,年龄(r=0.382,P=0.021)、透析前收缩压(r=0.116,P=0.000)、透析后收缩压(r=0.147,P=0.000)及PTX3水平(r=0.251,P=0.000)与CMBs呈正相关。结论 透析治疗可加重机体炎症反应;血清PTX3水平增高是血液透析患者CMBs发生的危险因素。     

不同透析方式对血液透析患者晚期糖基化终末产物、同型半胱氨酸及炎症因子的影响

目的 观察低通量血液透析(LFHD)、高通量血液透析(HFHD)和血液透析滤过(HDF)对维持性血液透析(MHD)患者晚期糖基化终末产物(AGEs)、同型半胱氨酸(Hcy)及炎症因子的影响.方法 选取MHD患者54例,随机分为LFHD组18例、HFHD组18例和HDF组18例,监测治疗前后AGEs、Hcy、C反应蛋白(CRP)、白细胞介素6(IL-6)及肿瘤坏死因子(TNF-α)的变化,30名健康体检者作为正常对照.结果 正常对照组及54例MHD患者透析前AGEs、Hcy、CRP、IL-6及TNF-α比较差异均有统计学意义(F值分别为44.10、34.73、11.07、30.75、47.01,P均＜0.01).HFHD组首次透析前、后AGEs[(109.97 ±15.65)、(88.78±11.89) mg/L,t=2.720,P＜0.05]及Hcy[(29.99±5.74)、( 22.17±5.29) μmol/L,t=7.365,P＜0.05]比较差异均有统计学意义,但CRP、IL-6及TNF-α下降不明显(t值分别为0.960、0.826、1.323,P均＞0.05)；透析8个月前、后AGEs有下降趋势(t=2.125,P ＞0.05),Hcy [(29.99 ±5.74) 、(21.71 ±4.21) μmol/L,t=6.982,P＜0.05] 、CRP[(7.53±3.22) 、(4.62±1.54) mg/L,t=2.907,P＜0.05]、IL-6 [(355.73 ±49.81) 、(240.18 ±64.89)ng/L,t=4.646,P＜0.05]及TNF-α[(552.28 ±96.11) 、(400.07 ±89.54) ng/L,t=4.905,P＜0.05]比较差异均有统计学意义.HDF组首次透析前、后AGEs[(110.64 ±16.54)、(74.53 ±14.17) mg/L,t=11.982,P＜0.05]、Hcy [(30.41±5.95)、(16.71 ±3.78)μmol/L,t=9.329,P＜0.05] 、CRP[(7.21±2.14)、(5.34±1.80) mg/L,t=2.993,P＜0.05] 、IL-6[(357.57±48.21)、(256.91±54.01) ng/L,t=4.631,P＜0.05]及TNF-α[(558.56±106.67) 、(398.86 ±61.19) ng/L,t=5.760,P＜0.05]比较差异均有统计学意义；透析8个月前、后AGEs[(110.64±16.54)、(80.82±10.30) mg/L,t=7.623,P＜0.05]、Hcy[( 30.41±5.95)、(15.99±2.97) μmol/L,t=8.493,P＜0.05] 、CRP[(7.21 ±2.14) 、(3.14±1.12) mg/L,t=4.403,P＜0.05] 、IL-6 [(357.57±48.21)、(146.75±31.68) ng/L,t=10.283,P＜0.05]及TNF-α[(558.56±106.67)、(288.86±41.95) ng/L,t=8.803,P＜0.05]比较差异均有统计学意义.透析8个月后,HDF组AGEs、Hcy、CRP、IL-6及TNF-α低于HFHD组同期水平(P均＜0.05).LFHD组单次和透析8个月后均不能降低AGEs、Hcy、CRP、IL-6、TNF-α(P均＞0.05).结论 MHD患者存在微炎症状态,HDF和HFHD可以降低MHD患者AGEs及Hcy水平,改善微炎症状态,HDF可能优于HFHD.     

晚期糖基化终产物对不同血液透析龄患者单核细胞分泌功能的影响

目的:观察晚期糖基化终产物对不同血液透析龄患者单核细胞分泌炎症细胞因子的影响,探讨晚期糖基化终产物对慢性肾功能衰竭和透析患者微炎症的作用机制。方法:①选择广东医学院附属医院肾内科2004-12/2006-02收治的慢性肾功能衰竭患者63例,其中保守治疗组16例,血液透析组47例,血液透析组按透析时间长短分为短期、中期及长期透析3组,以15例健康体检者为正常对照。②收集清晨空腹或透析前肝素抗凝全血5.0～6.0mL,分离外周血单个核细胞后分3组继续培养24h:AGE-BSA组给予糖基化的牛血清白蛋白(25mg/L)刺激,牛血清白蛋白组给予牛血清白蛋白(25mg/L),空白对照组不给刺激。③培养24h后收取培养上清液采用ELISA法测定白细胞介素1β和肿瘤坏死因子α的质量浓度。结果:①外周血单个核细胞白细胞介素1β分泌量:自发状态(空白对照)的正常对照组及保守治疗组分别为(10.08±0.77),(14.32±0.54)ng/L,短期、中期及长期透析组高于保守治疗组[(78.55±7.89),(56.16±1.66),(37.03±1.78)ng/L,P<0.05],且分泌量随血液透析时间的增加而减少(P<0.05);给予牛血清白蛋白刺激后,各组的白细胞介素1β分泌量与空白对照比变化不大(P>0.05);给予糖基化的牛血清白蛋白刺激后,各组的白细胞介素1β分泌量均显著高于空白对照(P<0.01),短期、中期及长期透析组低于保守治疗组[(132.09±23.66),(94.09±13.07),(68.14±10.56),(160.34±17.06)ng/L],且随血液透析时间的增加分泌量减少(P<0.05)。②外周血单个核细胞肿瘤坏死因子α分泌量:自发状态(空白对照)的正常对照组及保守治疗组分别为(8.57±0.32),(10.89±0.68)ng/L,短期、中期及长期透析组高于保守治疗组[(43.12±8.01),(30.78±5.34),(19.06±3.91)ng/L,P<0.05],且分泌量随血液透析时间的增加而减少(P<0.05);给予牛血清白蛋白刺激后,各组的肿瘤坏死因子α分泌量与空白对照比变化不大(P>0.05);给予糖基化的牛血清白蛋白刺激后,各组的肿瘤坏死因子α分泌量均显著高于空白对照(P<0.01),短期、中期及长期透析组低于保守治疗组[(72.62±20.11),(51.08±14.78),(35.03±6.67),(103.14±9.05)ng/L],且随血液透析时间的增加分泌量减少(P<0.05)。结论:血液透析患者普遍存在微炎症状态,晚期糖基化终产物参与慢性肾功能衰竭微炎症发生与发展,长期血液透析导致单核细胞功能紊乱而加重肾功能衰竭的进展。     

糖尿病肾病维持性血液透析患者住院原因及相关因素分析

目的 分析糖尿病肾病维持性血液透析患者住院原因及相关危险因素.方法 对2009年3月至2012年2月首都医科大学附属北京同仁医院56例糖尿病肾病维持性血液透析患者进行回顾性分析,按是否住院治疗分为住院组(29例)和非住院组(27例),观察住院患者的住院原因,比较两组患者的年龄、透析龄、收缩压、舒张压、血红蛋白、血糖、透析前血肌酐、透析前血钾、血浆白蛋白、透析前血钙、透析前血磷、全段甲状旁腺激素和透析充分性(KT/V值)等临床指标,利用多元逐步回归的方法分析糖尿病肾病血液透析患者住院的相关危险因素.结果 24个月中,56例患者中29例有住院记录;共计住院56例次;每次住院时间(29.62±14.30)d;住院的主要原因分别是心血管疾病(35.7％)、血管通路狭窄(30.4％)和肺部感染(17.8％).住院及非住院患者的年龄、血浆白蛋白和KT/V等指标的比较差异均有统计学意义[年龄:(66.97±9.94)岁与(57.42±11.77)岁,t=2.917,P=0.02;血浆白蛋白:(34.02±4.76) g/L与(38.93±3.82) g/L,t=-4.573,P=0.000;KT/V:(1.16±0.09)与(1.39±0.18),t =6.503,P=0.000].多元逐步回归分析结果发现,血浆白蛋白和KT/V是影响糖尿病肾病血液透析患者住院的相关危险因素(β=-1.724,P=0.00;β=-0.040,P=0.02).结论 心血管疾病、血管通路狭窄和肺部感染是导致糖尿病维持性血液透析患者住院主要原因;低蛋白血症、透析充分性不足是影响其住院的相关危险因素.     

高通量血液透析对维持性血液透析患者血清叶酸、维生素B12水平的影响

目的研究高通量血液透析治疗对维持性血液透析患者血清叶酸、维生素B12水平的影响.方法前瞻性、自身对照研究.30例常规低通量血液透析患者,转换为高通量透析(FreseniusFX60,超纯透析液)治疗6月.试验前(O月)采透析前,试验后3、6月分别采透析前、后血样测定血清叶酸、维生素B12的水平.结果转换为高通最血液透析与原低通量血液透析比较血清叶酸、维生素B12浓度没有变化.血清叶酸透析前水平从实验开始时0、3、6月分别为(5.16±0.87)ng/ml,(4.94±0.85)ng/ml与(4.75±0.77)ng/ml.虽然呈下降趋势,但组间比较没有统计学差异(t0/3=0.962,t0/6=1.826,t3/6=0.836,P＞0.05).血清叶酸水平透析前后无明显变化.血维生素B12透析前水平在试验前、后比较差异无统计学意义(t0/3=0.120,t0/6=0.337,t3/6=0.436 P＞0.05),分别为(419.13±136.83)pg/ml,(414.00±153.16)pg/ml与(432.83±139.12)pg/ml,透析前后血维生素B12水平没有变化.结论高通量血液透析治疗后未发现血清叶酸、维生素B12丢失增加.     

联机血液透析滤过纠正尿毒症血液透析患者钙磷代谢紊乱临床观察

目的 探讨联机血液透析滤过(HDF)、综合血液透析(HD)对患者钙、磷、甲状旁腺激素(PTH)清除效果.方法 取本血液净化中心维持性血液透析患者40例,随机分为两组,联机HDF组(n=20)和HD组(n=20).维持透析6个月后检测透析前、透析后钙、磷、PTH.结果 联机HDF组透析前后血钙水平为(1.90±0.35) mmol/L vs(2.20±0.67)mmol/L,HD组分别为(2.02±0.22)mmol/L vs (2.30±0.18) mmol/L,两组透析后血钙均有轻度升高,但两组透析后差异无统计学意义(P＞0.05);联机HDF组透析前后血磷水平为(2.45±0.41) mmol/L vs (1.70±0.15)mmol/L;而HD组分别为(2.52±0.60) mmol/L vs(1.82±0.20)mmol/L,两组患者接受透析后较透析前其血磷浓度均有明显的降低,并且两组透析后差异有统计学意义(P＜0.05).联机HDF组透析前后血PTH为(702.0±14.3)ng/L vs(345.0±16.8)ng/L; HD组分别为(697.2±13.2)ng/L vs(391.7±19.4)ng/L,两组患者在接受治疗后均有明显的降低,而联机组患者其治疗后含量明显低于HD组(P＜0.05).结论 联机HDF可以有效清除维持性血液透析患者血液中钙、磷PTH,改善患者预后.     

维持性血液透析患者高频透析相关低血压与透析后乳酸水平相关性研究

目的研究维持性血液透析患者高频透析相关低血压(intradialytic hypotension,IDH)与透析后乳酸水平之间的关系。方法选取2018年1～12月间在首都医科大学附属北京朝阳医院血液净化科115例规律维持性血液透析患者为研究对象,根据是否发生高频IDH(3个月透析中IDH发生频率≥30%)分为观察组和对照组。记录患者的一般资料和实验室资料,采取独立样本t检验探讨观察组与对照组患者透析前透析后血气分析和透析前血常规、肾功能、离子、尿酸、血糖、C反应蛋白等之间的关系。采用二元Logistic回归分析高频IDH的重要影响因素。绘制受试者工作特征曲线,评价透析后乳酸对高频IDH的诊断价值。P0.05为差异具有统计学意义。结果高频IDH的患者占23.48%(27/115)。观察组患者红细胞平均血红蛋白浓度较对照组低[(321.670±10.144)g/L比(328.659±10.974)g/L, t=-2.944,P=0.004],红细胞分布宽度-CV升高(14.496%±1.535%比13.686%±0.945%,t=2.594,0.014),透析后血气分析乳酸升高[(1.881±0.627)mmol/L比(1.437±0.700)mmol/L,t=2.949, P=0.004],差异具有统计学意义。Logistic回归分析显示红细胞分布宽度-CV升高和透析后乳酸升高是透析高频IHD发生的危险因素(OR=1.630,95%CI 1.046～2.539,P=0.031;OR=2.364,95%CI1.237～4.517,P=0.009)。ROC曲线显示,透析后乳酸曲线下面积AUC=0.721,95%CI 0.605～0.837, P=0.001。结论透析后乳酸升高是高频IDH的危险因素,具有一定的预测价值。     

高通量血液透析对尿毒症患者微炎症及营养不良的影响

目的探讨高通量血液透析对尿毒症患者微炎症及营养不良的影响。方法前瞻性选取2017年3月至2019年6月中国人民解放军联勤保障部队第九四二医院收治的尿毒症血液透析患者86例,采用随机数字表法将患者分为高通量透析组(HFHD组)和常规透析组(HD组),每组各43例。HFHD组采用高通量透析治疗,HD组采用传统透析治疗。比较两组患者透析治疗6个月后血清肿瘤坏死因子-α(TNF-α)、超敏C反应蛋白(hs-CRP)和白细胞介素-6(IL-6)水平变化,并进行营养状况评估。结果治疗前,两组患者的血清TNF-α、hs-CRP、IL-6水平比较(41.53±6.32 ng/L vs.40.84±8.21 ng/L;7.45±1.23 mg/L vs.7.37±1.12 mg/L;26.41±5.98 ng/L vs.25.98±4.71 ng/L),差异无统计学意义(t=0.475、0.783、0.572;P>0.05);治疗6个月后,HFHD组患者的血清TNF-α、hs-CRP、IL-6水平显著低于HD组(29.31±4.87 ng/L vs.37.44±6.02 ng/L;4.71±0.76 mg/L vs.6.12±0.94 mg/L;17.34±3.74 ng/L vs.21.33±4.51 ng/L),差异具有统计学意义(t=4.812、5.982、4.331;P=0.002、<0.001、0.011)。治疗前,两组患者营养不良的比率比较(53.49%vs.55.81%),差异均无统计学意义(χ^2=0.046,P=0.828),治疗6个月后,HFHD组患者营养不良的比率显著低于HD组(18.60%vs.44.19%),差异具有统计学意义(χ^2=6.532,P=0.010)。结论高通量血液透析较常规的低通量血液透析有明显的优点,在改善尿毒症患者的微炎症状态与营养状况方面具有一定优势。     

维持性血液透析患者住院原因及相关因素分析

目的分析血液透析患者住院原因及相关因素。方法对2009年3月～2011年2月首都医科大学附属北京同仁医院99例长期维持性血液透析患者进行回顾性分析,观察住院患者的住院原因,比较住院和非住院患者的年龄、透析龄、收缩压、舒张压、血红蛋白、血糖、透析前血肌酐、透析前血钾、血浆白蛋白、透析前血钙、透析前血磷、全段甲状旁腺激素和透析充分性(Kt/V值)等临床指标,利用多元逐步回归方法分析患者住院的相关危险因素。结果 24个月中,99例患者59人有住院记录;共计住院106例次,平均住院次数为1.07±1.22次;每次住院时间28.27±24.73天;住院的主要原因分别是心血管疾病、血管通路阻塞和肺部感染。住院组患者的年龄显著高于非住院组(66.6±12.62比56.63±13.16,P=0.000)岁,住院组透析前血肌酐和血浆白蛋白显著低于非住院组(804.05±226.01比954.80±226.35,P=0.030)μmol/L和(33.13±4.16比37.30±3.33,P=0.000)g/L。多元逐步回归分析结果发现,低透析龄和低蛋白血症是影响血液透析患者住院的相关危险因素(β=-0.030和-0.413)。结论心血管系统疾病仍然是血液透析患者住院首要原因,血管通路阻塞和肺部感染是血液透析患者住院的重要原因。低蛋白血症和低透析龄是影响其住院的相关危险因素。     

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.