药物防护电磁脉冲所致海马神经元损伤的可能性

背景:电磁脉冲照射可引起实验大鼠学习记忆能力下降,并可造成离体海马神经元的胞内钙超载,进而发生坏死和凋亡,物理屏蔽可减轻电磁辐射对实验动物的损伤,但缺乏在细胞模型上进行的药物防护研究。目的:观察药物防护电磁脉冲致离体海马神经元损伤的可能性。设计:随机对照动物实验。单位:承德医学院基础部。材料:实验于2004-01/2005-01分别在军事医学科学院和承德医学院完成。实验动物选用Wistar乳鼠若干只。方法:断头取脑分离海马组织,进行海马神经元原代培养与鉴定,原代培养的海马神经元经MK801(N-甲基-D-天冬氨酸受体拮抗剂)和尼非地平(L型钙离子通道阻断剂)预处理后进行电磁脉冲照射。电磁脉冲照射条件为6×104V/m,脉冲上升时间20ns,脉宽30μs,频率2.5脉冲/min,作用2min。将培养在特殊培养皿的细胞分为正常对照组、电磁脉冲照射组、MK80120μmol/L组和MK80120μmol/L 尼非地平1μmol/L组。采用MTT法对细胞活力进行测定;FACS法检测细胞凋亡率;Fluo-3-AM荧光探针负载、激光共聚焦显微镜扫描测定神经元胞内游离钙离子浓度[Ca2 ]i。主要观察指标:各组细胞内钙超载、细胞活力、细胞调亡的情况比较。结果:①电磁脉冲组在照射后即刻的[Ca2 ]i荧光强度显著高于正常对照组,差异有显著性意义([107.34±26.14),(54.93±16.08),P<0.05];MK80120μmol/L组比电磁脉冲照射组的[Ca2 ]i荧光强度有所下降(81.29±19.96,P<0.05),而MK80120μmol/L 尼非地平1μmol/L组的[Ca2 ]i荧光强度呈进一步下降趋势(69.82±25.54,P<0.05)。但两个给药组的[Ca2 ]i荧光强度仍高于正常对照(P<0.05)。②MK80120μmol/L组和MK80120μmol/L 尼非地平1μmol/L组反映细胞增殖活力的吸光度值分别为0.25±0.06和0.27±0.07,明显高于电磁脉冲照射组(0.17±0.08,P<0.05),但仍低于正常对照组(0.33±0.08,P<0.05)。③电磁脉冲照射组在照后即刻的细胞凋亡率显著高于正常对照组,差异有显著性意义([68.63±9.04)%,(20.14±4.34)%,P<0.01];MK80120μmol/L组比电磁脉冲照射组的细胞凋亡率有所下降(62.12±11.08)%,MK80120μmol/L 尼非地平1μmol/L组的细胞凋亡率呈进一步下降趋势([53.69±13.60)%,P<0.05)],但两个给药组的细胞凋亡率仍高于正常对照组(P<0.01)。结论:MK801和尼非地平预处理可部分阻断电磁脉冲所致的海马神经元损伤;细胞内钙超载在电磁脉冲损伤机制中发挥重要作用。     

甘草苷对慢性应激抑郁模型大鼠的抗抑郁作用

目的:观察甘草苷对慢性抑郁模型大鼠的疗效,探讨其抗抑郁样作用的可能机制。方法:实验于2005-06/07在北京大学医学部完成。72只成年雄性SD大鼠,根据其体质量采用区组随机化的方法将大鼠分为6组,每组12只:正常对照组、模型组(应激 灌胃双蒸水)、氟西汀组(应激 灌胃氟西汀),以及甘草苷10mg/kg、20mg/kg、40mg/kg组(应激 灌胃甘草苷)。采用慢性应激加孤养造模,应激持续5周,从第3周起进行药物干预。盐酸氟西汀原料药由常州四药公司提供。甘草苷由北大药学院生药学生物技术研究室提供。采用糖水消耗实验和强迫游泳实验观察大鼠行为学改变。实验结束后断头取血,分离血浆和红细胞,用试剂盒测定红细胞超氧化物歧化酶活性和血浆丙二醛浓度。结果:实验中,1只大鼠脚趾受伤,2只造模时意外溺亡,共69只大鼠进入结果分析。①慢性应激大鼠糖水消耗量较正常对照组明显降低[(8.3±0.9),(14.4±0.8)g,P<0.01];治疗后糖水消耗量增加,差异均具有显著性[甘草苷10、20、40mg/kg组分别为(11.4±1.2),(14.1±1.0),(14.0±0.8)g,氟西汀组为(13.0±1.9)g,P<0.05或0.01]。②与对照组相比,模型组大鼠不动时间显著延长[(37±9),(96±10)s,P<0.01];与模型组相比,给药各组大鼠的不动时间均显著缩短[甘草苷10、20、40mg/kg组分别为(66±10),(26±8),(41±11)s,氟西汀组为(63±8)s,P<0.05或0.01]。③模型组红细胞超氧化物歧化酶活性低于正常对照组[(35.4±6.8),(44.5±4.6)μkat/g,P<0.01];甘草苷各组后超氧化物歧化酶活性均高于模型组[20、40mg/kg组分别为(42.2±3.8)μkat/g,P<0.05;(45.3±7.9)μkat/g,P<0.01];氟西汀组超氧化物歧化酶活性与模型组相比差异无显著性。④模型组血浆丙二醛浓度高于正常对照组[(3.4±0.6),(1.9±0.4)μmol/L,P<0.01];甘草苷治疗组血浆丙二醛浓度降低[20、40mg/kg组分别为(2.2±0.9)μmol/L,P<0.05;(1.9±0.7)μmol/L,P<0.01]。结论:甘草苷可以改善抑郁模型中快感缺乏的症状,并能对抗绝望行为,支持甘草苷具有抗抑郁样作用的假设。甘草苷抗抑郁样作用可能通过提高机体超氧化物歧化酶活性,清除自由基,阻止脂质的过氧化,减少丙二醛的生成实现的。     

丹参酮ⅡA磺酸钠影响血管紧张素Ⅱ诱导心肌肥大及p-JNK和丝裂原活化蛋白激酶磷酸酶1的表达

目的:观察丹参酮ⅡA衍生物-丹参酮ⅡA磺酸钠对血管紧张素Ⅱ诱导的心肌肥大及p-JNK,丝裂原活化蛋白激酶磷酸酶1表达的影响。方法:实验于2005-11/2006-03于华中科技大学同济医学院实验中心完成。取1d龄新生清洁级Wistar乳鼠10只,雌雄不拘,取心室肌组织分离培养新生大鼠心肌细胞,将细胞均匀地接种于6孔培养板,每孔2mL。第3天将培养的细胞分为5组,即对照组,血管紧张素Ⅱ组,丹参酮ⅡA磺酸钠2,10,50μmol/L组,分别给予相应药物。对照组给予生理盐水,其余各组均给予血管紧张素Ⅱ1μmol/L进行心肌细胞肥大诱导,在此基础上,丹参酮ⅡA磺酸钠2,10,50μmol/L组再分别给予相应浓度的丹参酮ⅡA磺酸钠,以上浓度为培养基内终浓度。采用考马斯亮蓝法测定心肌细胞蛋白含量;采用[3H]-亮氨酸掺入法测定蛋白合成速率作为心肌肥大指标;用Western-blot测定p-JNK,丝裂原活化蛋白激酶磷酸酶1表达。观察各组心肌细胞总蛋白质含量、[3H]-亮氨酸掺入测定结果、p-JNK,MKP-1蛋白表达。结果:①用刺激因素处理24h后,2,10,50μmol/L丹参酮ⅡA磺酸钠组总蛋白含量明显低于血管紧张素Ⅱ组[(65.38±1.26),(53.41±3.63),(48.42±2.61),(80.42±3.28)μg/孔,P<0.05～0.01]。②1μmol/L血管紧张素Ⅱ作用24h后,2,10,50μmol/L丹参酮ⅡA磺酸钠组心肌细胞合成速率显著低于血管紧张素Ⅱ组[(140.52±12.04)%,(120.58±8.72)%,(111.88±10.06)%,(163.04±11.38)%,P<0.01]。③1μmol/L血管紧张素Ⅱ作用24h后,2,10,50μmol/L丹参酮ⅡA磺酸钠组p-JNK蛋白表达显著低于血管紧张素Ⅱ组[(145.96±11.98)%,(133.04±6.54)%,(116.56±11.61)%,(167.04±12.72)%,P<0.05～0.01]。④丹参酮ⅡA磺酸钠(10μmol/L)显著上调丝裂原活化蛋白激酶磷酸酶1表达,在40min时达到高峰达(132.16±7.88)%,随后下降,在60,80min分别为(110.72±10.94)%,(104.32±9.55)%,(P<0.01)。结论:丹参酮ⅡA磺酸钠可以抑制血管紧张素Ⅱ诱导的心肌细胞肥大,机制可能与上调丝裂原活化蛋白激酶磷酸酶1表达,降低p-JNK表达有关。     

丙泊酚联合利血平对再灌注损伤PC12细胞保护作用的研究

目的 观察丙泊酚与利血平单用或合用对缺血/缺氧及再灌注致中枢神经元细胞损伤的保护作用及其可能机制.方法 用大鼠肾上腺嗜铬细胞瘤克隆化细胞株(PC12细胞)建立缺血/缺氧及再灌注损伤的细胞模型.实验分为缺血/缺氧及再灌注损伤(IR)组、丙泊酚(P)组、利血平(R)组、丙泊酚与利血平合用(PR)组.通过测定乳酸脱氢酶(LDH)含量及应用噻唑蓝(MTT)比色法测定存活细胞在波长570 nm处的吸光度(A)值用以判断细胞损伤程度,并观察两药单独或合用对损伤PC12细胞内游离钙离子浓度([Ca2+]I)的影响.结果 与IR组比较,丙泊酚和利血平单用或联用组均可使LDH释放量明显降低,A值升高(P<0.05或P<0.01).合用利血平(40μmol/L)后,不同浓度丙泊酚(12.4、37.3和112.0μmol/L)组LDH释放量进一步降低,A值则增高(P均<0.05).12.4μmol/L和37.3μmol/L丙泊酚以及40μmol/L利血平均可减轻由于缺血/缺氧及再灌注损伤引起的细胞内钙超载[(279.66±18.00)nmol/L比(219.41±12.53)nmol/L,(279.66±18.00)nmol/L比(210.50±11.03)nmol/L,(279.66±18.00)nmol/L比(254.82±10.45)nmol/L,P<0.05或P<0.01];12.4/μmol/L和37.3μmol/L丙泊酚分别与40μmol/L利血平合用时,[Ca2+]I进一步降至(1 91.19±10.36)nmol/L和(183.82±9.83)nmol/L,与相同浓度丙泊酚组比较差异均有统计学意义(P均<0.05).结论 丙泊酚和利血平均对缺血/缺氧及再灌注损伤PC12细胞产生一定的保护作用,合用时保护作用更明显;其保护作用可能与减轻细胞内钙超载有关.     

盐酸氟桂嗪对同型半胱氨酸诱导的正常人脐静脉内皮细胞株胞内钙离子和细胞活性的影响

目的:观察盐酸氟桂嗪对同型半胱氨酸诱导的正常人脐静脉内皮细胞株(ECV-304)胞质内钙离子浓度和细胞活性的影响。方法:实验于2005-02/08在西京医院神经内科实验室完成。①分组:将ECV-304分为3组,正常对照组仅予空白RPMI-1640培养基培养;同型半胱氨酸组分别加入终浓度为100,200,500,1000μmol/L的同型半胱氨酸培养;盐酸氟桂嗪组加入终浓度为10μmol/L盐酸氟桂嗪及终浓度分别为100,200,500,1000μmol/L的同型半胱氨酸共培养。②细胞活性检测:用四唑盐法检测,各组细胞加入不同浓度药物培养24h后,测定各孔吸光度值A。③细胞质中[Ca2 ]i的测定:各组细胞加入不同浓度药物培养20min后,利用Ca2 指示剂Flu-3AM作为细胞内钙离子的荧光探针负载培养的细胞,共聚焦技术检测细胞内荧光强度的变化。结果:①同型半胱氨酸浓度为200,500,1000μmol/L时各组的反映细胞活性A值低于对照组(0.156±0.009,0.148±0.010,0.134±0.007,0.177±0.011,P<0.01),也低于含同浓度同型半胱氨酸的盐酸氟桂嗪组(0.168±0.011,0.160±0.009,0.148±0.007,P<0.05,0.01)。且随着同型半胱氨酸浓度的增加,A值逐渐降低。②在同型半胱氨酸组中,随同型半胱氨酸浓度增加反映细胞质中[Ca2 ]I的平均荧光强度也逐渐增强。同型半胱氨酸各浓度组平均荧光强度均高于对照组(P<0.01);也高于含相同浓度同型半胱氨酸的盐酸氟桂嗪组(P<0.01)。结论:①同型半胱氨酸对血管内皮细胞有损伤作用,其作用与胞内钙离子浓度升高密切相关。②盐酸氟桂嗪能减轻同型半胱氨酸所诱导的细胞损伤,可能与其直接抑制由同型半胱氨酸所诱导的Ca2 的内流,减轻细胞质钙超载有关。     

阿普卡林对低氧-复氧乳鼠心肌细胞保护作用的机制

目的探讨低氧/复氧(H/R)对心肌细胞内Ca浓度(犤Ca犦i)的影响,以及阿普卡林减轻H/R过程中钙超载的作用。方法采用SD大鼠乳鼠(n=80)进行心肌细胞培养,用Ca2+荧光指示剂Fluo-3/AM负载30min,然后分3组:(1)正常对照组;(2)H/R组:细胞低氧30min/复氧30min;(3)阿普卡林组:先加入终浓度为100μmol/L的阿普卡林,再行低氧30min/复氧30min。于两个实验组接受低氧处理前及刚开始复氧时、复氧30min后用激光共聚焦显微镜技术检测3个组心肌细胞犤Ca2+犦i的变化。实验重复8次,共观察24个细胞。结果对照组心肌细胞犤Ca2+犦i荧光强度和荧光光密度值较低,分别为645.5U,80.3U及0.5%,0.3%。低氧30min后复氧即刻,犤Ca2+犦i荧光光密度值开始增加,复氧30min后犤Ca2+犦i荧光强度和荧光光密度值显著增高(与对照组比较,P<0.01)。而阿普卡林组细胞内荧光光密度值显著低于H/R组(χ2=20.51,P<0.01)。结论心肌细胞H/R导致钙超载;而阿普卡林有明显减轻心肌细胞H/R时Ca2+超载的作用,从而保护心肌细胞。     

钙调蛋白激酶Ⅱ抑制剂对肥厚心肌细胞的影响

目的 观察钙调蛋白激酶Ⅱ(CaMKⅡ)抑制剂KN-93对肥厚心肌细胞L型钙电流(ICa,L)及细胞内钙离子浓度([Ca2+]i)的影响.方法 选取雌性新西兰大白兔48只,随机(随机数字法)分为4组:假手术组(sham组)、心肌肥厚组(LVH组)、心肌肥厚+KN-93组(KN-93组)、心肌肥厚+KN-92组(KN-92组),每组12只,通过缩窄腹主动脉制备兔心肌肥厚模型,Sham组仅游离腹主动脉未进行缩窄.8周后,采用胶原酶消化法分离单个心肌细胞,应用穿孔膜片钳技术记录L型钙电流(ICa,L);应用钙荧光指示剂Fura-2/AM结合图像分析技术测定各组心肌细胞内[Ca2+]i.结果 8周后,心肌肥厚模型建立成功.在0 mV时LVH组、Sham组的峰值ICa.L分另为(1.38±0.3)nA、(0.87±0.1)nA(P＜0.01,n=12),电流密度分别为(6.7±1.0)pA/pF、(6.3 ±0.7)pA/pF(P＞0.05,n=12).当KN-92及KN-93在浓度为0.5μmol/L时,可分别使肥厚心肌细胞0 mV时的峰值ICa,L降低(9.4±2.8)％、(10.5±3)％(P＞0.05,n=12);当浓度增至1 μmol/L时,其峰值ICa,L降低程度分别为(13.4±3.7)％、(40±4.9)％(P＜0.01,n=12).Sham组、LVH组、KN-92组及KN-93组中心肌细胞[Ca2+]i分别为(98.0±12.3)nmol/L、(154.0±26.2)nmol/L、(147.0±29.6)nmol/L和(108.0±21.2)nmol/L.结论 CaMKⅡ特异性抑制剂KN-93可有效抑制肥厚心肌细胞ICa.L,减轻细胞内钙超载,这可能是其抗肥厚心肌室性心律失常发生的主要细胞电生理机制.     

芍药苷对H_2O_2诱导的H9C2心肌细胞损伤的保护作用

目的探讨芍药苷对H_2O_2诱导的H9C2心肌细胞损伤的保护作用。方法培养H9C2心肌细胞,用不同浓度的H_2O_2(50、100、200、400、800、1 600μmol/L)作用于心肌细胞4 h,选出H9C2心肌细胞氧化损伤模型的浓度。以50、100、200μmol/L的芍药苷预处理心肌细胞24 h,以选出的浓度为400μmol/L的H_2O_2建立氧化损伤模型,采用MTT法检测H9C2心肌细胞的活力,化学试剂盒检测心肌细胞乳酸脱氢酶(LDH)漏出量、丙二醛(MDA)、超氧化物歧化酶(SOD)的含量。多组间比较采用单因素方差分析,组间两两比较用LSD检验。结果各H_2O_2浓度组细胞活力显著低于对照组,差异具有统计学意义(P<0.05);各芍药苷浓度组细胞活力高于H_2O_2模型组,且随着芍药苷浓度的升高而升高,差异具有统计学意义(P<0.05);各芍药苷浓度组细胞活力低于对照组,差异具有统计学意义(P<0.05);各芍药苷浓度组细胞LDH漏出量、MDA含量显著低于H_2O_2模型组,且随着芍药苷浓度的升高而降低,差异具有统计学意义(P<0.05);各芍药苷浓度组细胞LDH漏出量、MDA含量高于对照组,差异具有统计学意义(P<0.05);各芍药苷浓度组细胞SOD含量显著高于H_2O_2模型组,且随着芍药苷浓度的升高而升高,差异具有统计学意义(P<0.05);各芍药苷浓度组细胞SOD含量显著低于对照组,差异具有统计学意义(P<0.05)。结论芍药苷对H_2O_2诱导的H9C2心肌细胞的损伤有明显的保护作用。     

阻塞性睡眠呼吸暂停低通气综合征患者呼出气冷凝液中一氧化氮浓度与体内氧化应激的关系

目的 探讨阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者慢性间歇低氧对氧化应激的影响.方法 选取2005年6月至2006年6月于我院呼吸科就诊的120例成年OSAHS患者及30例健康志愿者,OSAHS组中轻度60例,中重度组60例.采用硝酸还原酶法测定晨起呼出气冷凝液中一氧化氮(NO)浓度,并同时抽取静脉血测定其丙二醛(MDA)和超氧化物歧化酶(SOD)浓度.结果 各组睡前呼出气冷凝液中NO浓度无明显差别[OSAHS中重度组(15±8)μmol/L,轻度组(16±10)μmol/L,正常对照组(14±6)μmol/L];晨起各组呼出气冷凝液中NO浓度分别为:OSAHS中、重度组(8±5)μmol/L,轻度组(11±6)μmol/L,正常对照组(13±7)μmol/L,OSAHS组和正常对照组比较差异有统计学意义(P<0.05或P<0.01);OSAHS中重度组、轻度组和正常对照组血清MDA和SOD浓度分别为(16.78±1.99)、(7.76±0.87)、(4.73±0.92)μmol/L和(69.38±12.65)、(90.05±16.12)、(120.65±19.78)μU/L,OSAHS组和正常对照组比较差异均有统计学意义(P<0.05或P<0.01);OSAHS组晨起凝冷液中NO浓度与呼吸暂停低通气指数(AHI)呈负相关(r=-0.463,P<0.05),与最低氧饱和度(SaO2min)呈正相关(r=0.675,P<0.05).而MDA与AHI呈正相关(r=0.862,P<0.01)、与SaO2min呈负相关(r=-0.774,P<0.01),SOD与AHI呈负相关(r=-0.619,P<0.05)、与SaO2min呈正相关(r=0.687,P<0.05).结论 OSAHS患者晨起呼出气冷凝液中NO浓度明显下降,可间接反映机体NO消耗情况,MDA升高、SOD下降,从而导致氧化应激,与OSAHS病情严重程度显著相关.     

Na+/H+交换抑制剂HMA抑制低氧刺激的大鼠肺动脉平滑肌细胞增殖

目的:观察低氧培养对大鼠肺动脉平滑肌细胞增殖的影响,以及Na /H 交换抑制剂HMA对此增殖效应的抑制作用。方法:实验于2004-12/2005-06在第四军医大学病理生理学教研室完成。健康SD大鼠2只,分离培养肺动脉平滑肌细胞,选择3～6代生长良好的细胞在常氧(O2的体积分数为0.21)或低氧(O2的体积分数为0.02)条件下培养,并分别给予0.3,1,3和10μmol/L等不同浓度的HMA(n=8),采用噻唑蓝比色实验和测定细胞总蛋白含量的方法观察细胞增殖情况,同时光镜观察细胞形态并测定培养液上清乳酸脱氢酶活力以反映药物的非特异性细胞毒作用。结果:实验所用细胞样本均进入结果分析。①体积分数为0.02氧浓度较体积分数为0.05氧浓度下培养的大鼠肺动脉平滑肌细胞生长曲线抬高,低氧刺激24h增殖达到高峰。②体积分数为0.05血清培养使此增殖效应更为显著[噻唑蓝光吸收值无血清常氧组(0.238±0.011),无血清低氧组(0.280±0.009),体积分数为0.05血清常氧组(0.313±0.013),体积分数为0.05血清低氧组(0.389±0.011)]。③HMA可以抑制增殖,显著降低噻唑蓝吸光度值[对照组(0.391±0.011),0.3μmol/L组(0.377±0.010),1μmol/L组(0.328±0.012),3μmol/L组(0.289±0.006),10μmol/L组(0.246±0.007)]。④细胞总蛋白含量也显著降低[对照组、0.3μmol/L组、1μmol/L组、3μmol/L组、10μmol/L组分别为(193.30±8.51),(177.63±8.71),(166.84±9.48),(155.72±10.46)和(135.13±10.30)μmol/L]。⑤各浓度处理组细胞形态无改变,培养液上清乳酸脱氢酶活力也无明显变化[对照组、0.3μmol/L组、1μmol/L组、3μmol/L组、10μmol/L组分别为(212.23±8.44),(208.80±6.37),(209.79±7.12),(208.77±7.33),(215.42±7.81)U/L],细胞无明显损伤。结论:0.3～10μmol/L浓度的Na /H 交换抑制剂HMA可以有效抑制低氧刺激的大鼠肺动脉平滑肌增殖,此作用不是非特异的细胞毒作用所致。     

Guns and Knives in New Mexico: Patterns of Penetrating Trauma, 1978–1993

Objective: To identify patterns of nonfatal and fatal penetrating trauma among children and adults in New Mexico using ED and medical examiner data.
Methods: The authors retrospectively sampled in 5-year intervals all victims of penetrating trauma who presented to either the state Level-1 trauma center or the state medical examiner from a 16-year period (1978–1993). Rates of nonfatal and fatal firearm and stabbing injury were compared for children and adults.
Results: Rates of nonfatal injury were similar (firearm, 34.3 per 100,000 person-years; stabbing, 35.1). However, rates of fatal injury were significantly different (firearm, 21.9; stabbing, 2.7; relative risk: 8.2; 95% confidence interval: 5.4, 12.5). From 1978 to 1993, nonfatal injury rates increased for children (p = 0.0043) and adults (p < 0.0001), while fatal penetrating injury remained constant. The increase in nonfatal injury in children resulted from increased firearm injury rates. In adults, both stabbing and firearm nonfatal injury rates increased.
Conclusions: Nonfatal injury data suggest that nonfatal violence has increased; fatal injury data suggest that violent death rates have remained constant. Injury patterns vary by age, mechanism of trauma, and data source. These results suggest that ED and medical examiner data differ and that both are needed to guide injury prevention programs.     

Systematic Reviews Published in the January 2011 Issue of The Cochrane Library

ABSTRACT

The Cochrane Library of Systematic Reviews is published quarterly as a DVD and monthly online. The January 2011 issue (first quarterly DVD for 2011) contains 4515 complete reviews, 1985 protocols for reviews in production, and 13,521 one-page summaries of systematic reviews published in the general medical literature. In addition, there are citations of 641,000 randomized controlled trials, and 14,018 cited papers in the Cochrane methodology register. The health technology assessment database contains over 9300 citations. One hundred and seven new reviews have been published in the last 3 months, of which five have potential relevance for practitioners in pain and palliative medicine.     

Interprofessional approaches to creating safe,high quality health care

Three supplementary perspectives are presented arguing that interprofessional collaboration is both necessary and desirable. Nonetheless, there are often too many serious intra-professional barriers and obstacles to interprofessional collaboration to make it successful. Some of these barriers, it is argued and illustrated, are found in the multiple ways in which professional identity is tacitly acquired and embodied in the practitioners' habitual, everyday practice. The paper then explores ways in which reflection, especially Second order reflection, can help to elucidate and overcome these obstacles, as well as increasing professional adaptability and competence.     

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.     

Prise en charge des entorses externes de cheville : étude clinique préliminaire sur l’efficacité du dispositif Myolux™

Ankle sprains are the most common injury of the musculoskeletal system and are associated with significant societal and economic impacts. It has been proven that classical therapeutic strategies may not be effective in preventing recurrent injuries: the recurrence rates reported in the literature can reach 73%. In order to provide an effective rehabilitation solution, a destabilizing orthosis was developed. This device is equipped with a mechanical articulator reproducing the subtalar mechanics and placed under the heel. In this paper, we present the main results of a preliminary clinical study conducted between 2004 and 2007. All subjects included in this study were treated with the abovementioned orthosis during 10 rehabilitation sessions of 30 minutes each. Data show a relatively low recurrence rate of 12% for the overall population. Moreover, it's of primary importance to note that this satisfactory ratio is largely reduced (3% of recurrence rate) for the 29 patients who performed one training session per month after the 10th initial rehabilitation sessions. Hence, the destabilizing orthosis appears to be an effective solution to prevent recurrent ankle sprains. However, joint protection requires long-term and regular training sessions. This result has motivated the development of a similar device allowing patients to perform training sessions at home. Finally, data obtained in this study are promising awaiting the final results of the comparative, multicentric and independent clinical trials currently managed by the Hospices Civils de Lyon.     

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.