家兔急性缺氧后左心室舒张功能和心肌细胞内钙转运及能量代谢…

为探讨急性缺氧对家兔左心室舒张功能，心肌细胞内钙转运和能量代谢的影响，将２３只家兔分为对照组（６只），吸入５％低氧混合气的１组、吸入１０％低氧混合气的缺氧２组（Ｈ２）（５只），用心导管法测定左心室压力下降最大速率和压力下降时间常数（Ｔ值），测定心肌肌浆网钙ＡＴＰ酶活性，心肌ＳＲ摄钙量、心肌细胞ＡＴＰ和磷酸肌酸，结果，缺氧后ＬＶｄｐ／ｄｔｍａｘ下降，Ｔ值延长，缺氧组心肌ＳＲ钙ＡＴＰ酶活性及摄钙量下降     

肺炎对幼鼠心肌线粒体钙转运及能量代谢的影响

目的 探讨肺炎对心脏功能影响的机制。方法 采用气管内接种的方法建立幼鼠金黄色葡萄球菌肺炎模型,分离心肌线粒体,观察心肌线粒体Ｃａ＾２＋－ＡＴＰ酶活性,游离钙含量,钙摄取率和释放率以及心肌组织ＡＴＰ含量,结果 与对照组相比,肺炎组心肌线粒体Ｃａ＾２＋－ＡＴＰ酶活性下降（Ｐ〈０．０５）,游离钙含量升高（Ｐ〈０．０５）,钙摄取速率下降（Ｐ〈０．０５）,钙释放速率升高（Ｐ〈０．０５）,心肌组织ＡＴＰ含量下     

复方丹参注射液对小鼠心肌保护作用的研究

目的　探讨复方丹参注射液对小鼠心肌的保护作用。方法　２５ 只小鼠，随机分成缺氧组，丹参治疗组和对照组，实验２ 周后，取新鲜心肌标本，测琥珀酸脱氢酶（ＳＤＨ），三磷酸腺苷（ＡＴＰ） 酶，乳酸脱氢酶（ＬＤＨ），应用光镜和电镜观察心肌病理性变化。结果　缺氧组ＳＤＨ 和ＡＴＰ酶减少，ＬＤＨ 升高，心肌间质水肿，心肌细胞线粒体肿胀，肌丝排列紊乱，丹参治疗组，心肌酶和心肌超微结构与对照组相比均无显著性差异。结论　复方丹参对小鼠心肌缺氧损伤有保护作用。     

心脏肌浆网钙转运蛋白基因表达与调节

心肌细胞肌浆网（ｓａｒｃｏｐｌａｓｍｉｃｒｅｔｉｃｕｌｕｍ，ＳＲ）钙转运蛋白通过调节细胞内游离钙浓度对心肌细胞的收缩、舒张功能起着决定性作用。近年来研究表明，心肌ＳＲ钙转运蛋白表达异常是多种心脏病的重要病理生理机制。目前已发现多种参与ＳＲ钙转运蛋白表达调控的因素。     

1,6二磷酸果糖对大鼠阿霉素心肌病的防治作用及机理的探讨

为探讨１，６二磷酸果糖（ＦＤＰ）对大鼠阿霉素心肌病的防治作用及其机理，采用Ｗｉｓｔａｒ大鼠３０只，随机分为阿霉素（ＡＤＲ）组、ＡＤＲ＋ＦＤＰ组及对照组。实验６周后进行心肌的光、电镜病理形态学观察。结果：光、电镜下心肌病理损害程度，ＡＤＲ＋ＦＤＰ组较ＡＤＲ组轻；心肌组织的病理等级，ＡＤＲ＋ＦＤＰ组明显低于ＡＤＲ组；心肌细胞线粒体形态计量分析，ＡＤＲ＋ＦＤＰ组线粒体嵴膜的比膜面较ＡＤＲ组有明显增高趋势。提示，ＦＤＰ对大鼠阿霉素心肌病具有防治作用，且ＦＤＰ可能通过改善心肌细胞线粒体的能量代谢机制而发挥作用     

射频消融对兔心内膜单相动作电位影响的实验研究

目的探讨射频导管消融（ＲＦＣＡ）对心内膜单相动作电位（ＭＡＰ）的影响，为进一步完善ＲＦＣＡ的过程提供理论依据。方法选取健康家兔３６只，用接触电极导管监测ＲＦＣＡ前后兔心内膜的ＭＡＰ变化并观察ＲＦＣＡ不同时间（１０～６０秒）和不同温度（４０～９０℃）水平ＭＡＰ的变化。结果（１）单相动作电位振幅（ＭＡＰＡ）和０相最大上升速度（Ｖｍａｘ）随ＲＦＣＡ时间延长及温度升高而降低或下降，持续放电３０秒或温度达５０℃以后ＭＡＰＡ及Ｖｍａｘ几乎不再变化；（２）整个过程的单相动作电位时程（ＭＡＰＤ）无明显变化且未见心律失常发生。结论（１）当ＲＦＣＡ温度达５０℃心肌电活动以及心肌组织已经产生有效的损伤；ＲＦＣＡ对ＭＡＰＤ不产生影响，故不易导致心律失常（２）将ＭＡＰ记录与温度监测结合起来，对判断ＲＦＣＡ前导管心肌的接触及ＲＦＣＡ后心肌的损伤有一定的指导意义     

先天性巨结肠细胞能量代谢的酶学研究

为了解先天性巨结肠（ＨＤ）病变肠段细胞能量代谢的状况。通过酶组织化学方法对２０例ＨＤ患儿正常段、狭窄段全层组织，进行了五种酶的定性、定量及计数分析：①ＡＴＰ（ａｓｅ）（腺苷三磷酸酶），②ＳＤＨ（琥珀酸脱氢酶），③ＭＡＯ（单胺氧化酶），④ＣｈＥ（胆碱脂酶），⑤ＣｈＥ－Ａｇ（胆碱脂酶＋镀银）。发现狭窄段有如下变化：ＡＴＰ（ａｓｅ）、ＳＤＨ和ＣｈＥ活性显著升高（Ｐ＜０．０１）；ＭＡＯ活性显著降低（Ｐ＜０．０１）；粘膜下和肌间神经丛（ＣｈＥ＋Ａｇ）减少１／３，神经节细胞数（ＳＤＨ）减少４／５（Ｐ＜０．０１）。说明ＨＤ狭窄段细胞能量代谢是旺盛的，检测ＡＴＰ（ａｓｅ）、ＳＤＨ、ＭＡＯ可作为诊断ＨＤ新的参考。     

低浓度一氧化氮及妥拉苏林对兔低氧性肺动脉高压的作用比较

目的　探讨吸入低浓度一氧化氮（ＮＯ） 及妥拉苏林气管内和右心室内给药对肺动脉高压的作用。方法　予急性低氧性肺动脉高压家兔模型吸入６×１０－ ６ ＮＯ及气管内滴入和右心室内注入０－５ ｍｇ／ｋｇ 妥拉苏林,通过左颈总动脉插管和右心室插管观察平均动脉压（ＭＡＰ） 、右心室收缩压（ＳＲＶＰ）及血气的变化。结果　低氧通气使家兔ＳＲＶＰ由（１４－０ ±２－２） ｍｍＨｇ（１ ｍｍＨｇ＝ ０－１３３ ｋＰａ）上升至（１７－４±２－０） ｍｍＨｇ（Ｐ＜０－０５）,吸入６×１０－６ ＮＯ 后降至基础水平（ Ｐ＜ ０－０５）;吸入前后ＭＡＰ差异无显著意义（Ｐ＞ ０－０５）。低氧通气同时吸入ＮＯ对动脉血氧分压无影响。妥拉苏林两种给药途径均使ＭＡＰ和ＳＲＶＰ下降（Ｐ＜０－０５） ;气管内给药还使ＳＲＶＰ／ＭＡＰ比值由０－２１±０－０６ 下降至０－２０±０－０６（ Ｐ＜０－０５）,该效应与吸入ＮＯ相比,差异有显著意义（ Ｐ＜ ０－０５） 。气管内给药使ＭＡＰ、ＳＲＶＰ下降的百分率均小于右心室内给药（Ｐ＜０－０５）。结论　吸入６ ×１０－６ ＮＯ能选择性扩张肺血管;妥拉苏林气管内给药具有一定的肺血管选择性,仍弱于ＮＯ的作用;但右心室内给药缺乏肺血管选择性。     

早搏与心功能的关系及影响因素的研究

为探讨小儿早搏对心功能的影响，采用多普勒超声心动图测定４０例早搏患儿的单个早搏射血分数（ＰＢＥＦ）、心脏指数（ＰＢＣＩ）；单个非早搏的射血分数（ＮＰＢＥＦ）、心脏指数（ＮＰＢＣＩ）及实际的射血分数（ＡＥＦ）、心脏指数（ＡＣＩ）。同时研究这些指标与心电图和心肌酶的关系。结果显示：（１）早搏患儿ＰＢＥＦ、ＰＢＣＩ均小于ＮＰＢＥＦ、ＮＰＢＣＩ；病程长者ＰＢＥＦ、ＡＥＦ及ＡＣＩ均下降；室性早搏者的ＡＣＩ减少；早搏＞１０次／分者的ＡＥＦ及ＡＣＩ下降；Ｒ－Ｒ′／Ｒ－Ｒ比值小者的ＰＢＥＦ、ＡＥＦ及ＰＢＣＩ亦小；早搏ＱＲＳ－Ｔ综合波长者的ＰＢＥＦ及ＰＢＣＩ减少。（２）肌酸磷酸激酶同功酶（ＣＫ－ＭＢ）升高者的ＰＢＥＦ、ＡＥＦ、ＰＢＣＩ、ＡＣＩ均值的下降比ＣＫ－ＭＢ不升高者显著。研究提示，早搏＞１０次／分、Ｒ－Ｒ′／Ｒ－Ｒ＜０．６、ＱＲＳ－Ｔ综合波＞０．４秒和ＣＫ－ＭＢ＞１６ＩＵ／Ｌ者的心功能多受到影响，应予以积极治疗。     

Tei指数评价缺氧新生儿左心室功能障碍的作用研究

目的：探讨Tei指数在评价缺氧新生儿左心室功能障碍中的作用。方法：52例低氧血症新生儿（轻度20例,中重度各16例）和40例正常新生儿作为研究对象,于生后1、3、7 d用多普勒超声心动图测定反映心脏收缩及舒张功能的指标：左心室射血分数（LVEF）、二尖瓣口E/A值;左心室Tei指数（LV-Tei）。结果：（1）中度低氧血症组生后1、3 d LVEF、左室E/A值明显低于对照组（P<0.01）;重度低氧血症组生后1、3、7 d LVEF、左室 E/A 值均明显低于对照组（P<0.01或0.05）。（2）轻度低氧血症组生后1 d、中度及重度低氧血症组生后1 d、3 d LV-Tei 值明显高于对照组（P<0.01）。（3）低氧血症组生后1 d、3 d PaO2与LV-Tei呈负相关(r=-0.50, P<0.05; r=-0.71, P<0.01)。结论：LV-Tei可敏感地发现低氧血症患儿左心室功能下降,对临床的诊治有重要的指导作用。     

常规肺通气功能检测在儿童支气管哮喘诊疗中的作用

目的 通过对比支气管哮喘(哮喘)患儿规范化治疗前后肺功能指标的变化,探讨其大小呼吸道功能改变及改变时间段.通过对比哮喘患儿吸入支气管扩张剂前后肺功能变化,明确哮喘患儿对支气管扩张剂的反应及呼吸道狭窄、呼吸道阻塞的可逆性.方法 采用肺功能测定系统对25例哮喘患儿分别于哮喘急性发作期、正规治疗后缓解期3个月、6个月、1 a行常规肺通气功能测定,比较各期实测值与预测值;并从中选出10例患儿于急性发作期行支气管舒张试验,比较支气管扩张剂雾化吸入前后其肺功能指标变化. 结果 哮喘患儿急性发作期用力肺活量(FVC)、一秒钟用力呼气量(FEV1)、1秒率(FEV 1.0%)、最大呼气流量(PEF)、25%用力呼气肺活量(FEF25)、FEF50、FEF75、中段呼气流速(MMEF75/25)等实测值均较预测值降低,治疗3个月FVC、FEV1等大呼吸道功能指标恢复,治疗1 a、FEF50、FEF75、MMEF75/25等小呼吸道功能指标恢复.哮喘患儿支气管扩张剂雾化吸入后大呼吸道功能指标FEV1、PEF及小呼吸道功能指标FEF50、FEF75、MMEF75/25等均较雾化前恢复.结论 哮喘患儿的肺功能指标在急性期和缓解期存在特异性动态变化,肺功能检测在儿童哮喘的诊断、疗效及病情判断方面具有良好的作用.     

Defective neutrophil chemotaxis and bactericidal power in a child with hyperimmunoglobulinemia E

An 11-year-old boy with a life-long history of atopic-like dermatitis and recurrent staphylococcal abscesses was found to have defective neutrophil chemotaxis, impaired-T-lymphocyte functions, hyperimmunoglobulinemia E, and delayed neutrophil bactericidal power. This latter defect has never been found in such patients.The patient's mother revealed a panhypogammaglobulinemia, while his sister and maternal grandmother who had repeated infections were immunologically normal.     

Tubular and glomerular function in children after renal transplantation

Glomerular and tubular function of transplanted kidneys were assessed in 46 children aged 15.7 +/- 4.6 yr, 4.2 +/- 2.8 yr after renal transplantation. There were 34 cadaveric, and 12 living-related donors. Twelve patients (26%) had acute episodes (acute tubular necrosis, rejection, or urinary tract infection) during follow-up. All patients were on triple immunosuppression. The mean serum creatinine was 1.5 +/- 0.6 mg/dL. Creatinine clearance (Ccreat) calculated from a 24-h urine collection was 48.0 +/- 19.7 mL/min/1.73 m(2), and that estimated from the Schwartz formula, 61.0 +/- 22.5 mL/min/1.73 m(2). A positive correlation was found between the calculated and estimated clearances. Mean urine concentrating ability was 487 +/- 184 mOsmol/kg, with a value lower than 400 mOsmol/kg in 35% of patients. There was a positive correlation between urine osmolality and estimated Ccreat. Metabolic acidosis (bicarbonate <22 mmol/L) was found in 41% of patients, with relatively alkaline urine and high chloride level. Fractional excretion (FE) of sodium was above 1% in 68% of patients (mean 1.66 +/- 1.06%), and FE(Mg) was above 3% (mean 10.9 +/- 5.2%) in 93% of patients. Tubular reabsorption of phosphate (TP)/glomerular filtration rate (GFR) was 3.2 +/- 0.8 mg/dL glomerular filtrate (GF). FE(K), FE(UA), and Ca/creatinine in urine were normal. There were no functional group differences between the cadaveric and living-related kidneys. Significant group differences were found in those with acute episodes and those with a normal course. Estimated Ccreat was 54 +/- 20 vs. 67 +/- 20 mL/min/1.73 m(2) in the acute episodes and the normal course groups, respectively. Also, the FE(NA), FE(UA), and FE(Mg) were higher in the acute episodes group -2.3 +/- 1.6, 10.6 +/- 4.4, and 14.8 +/- 6.5%, respectively, compared with the normal course group -1.4 +/- 0.6, 8.2 +/- 2.8, and 9.6 +/- 4.0%, respectively. There were no between-group differences in plasma bicarbonate, FE(K), TP/GFR, and urine osmolality. We believe that most, if not all tubular dysfunctions in the transplanted kidney are secondary to renal failure and interstitial damage from acute episodes and nephrotoxic drugs. These dysfunctions are similar to those in chronic renal failure, where interstitial fibrosis plays a role in kidney function deterioration.     

Cognitive deficit in preschoolers born late-preterm

Background

Late-preterm (LPT) birth accounts for a majority of preterm deliveries and until recently was considered low risk for poor cognitive outcome. Previously, we reported deficits in complicated LPT (cLPT) preschoolers (neonatal intensive care unit [NICU]-admitted).

Aim

To extend our prior study by comparing cognitive outcome in cLPT and uncomplicated LPT (uLPT; NICU non-admitted) preschoolers.

Study design

Single center retrospective cohort study of 118 LPT children born in 2004-2006 at 35-36 weeks of gestation; 90 cLPT and 28 uLPT, compared with 100 term-born (≥ 37 weeks of gestation and ≥ 2500 g) participants.

Outcome measure

A well-standardized measure of general conceptual ability (GCA), the Differential Ability Scales, Second Edition.

Results

cLPT participants had average mean performances but significantly poorer GCA, Nonverbal Reasoning, and Spatial scores than term-born children, and higher rates of Nonverbal Reasoning and Spatial impairment; uLPT did not differ from TERM. Combined LPT males were at eightfold greater risk than term-born males for nonverbal deficit, and at sevenfold greater risk for GCA impairment than LPT females.

Conclusions

Finding greater risk of cognitive deficit in those NICU-admitted due to clinical instability or birth weight < 2 kg compared with non-admitted preschoolers indicates that neonatal morbidities contribute to subtle cognitive deficits detectable at young age, with male gender an additive risk factor. LPT gestational age alone is an insufficient predictor of long-term neurocognitive outcome. Further study should elucidate salient etiologies for early emerging cognitive weaknesses and suggest appropriate interventions to prepare at-risk LPT preschoolers for elementary school entry.     

Nephrotoxicity following carboplatin use in children: Is routine monitoring of renal function necessary?

Carboplatin is an effective chemotherapeutic agent against many solid tumours. Although it is thought to be less nephrotoxic than its precursor cisplatin, current paediatric treatment protocols require regular monitoring of renal glomerular function during and after carboplatin use. Because accurate assessment of renal function in children requires measurement of isotope-clearance glomerular filtration rates (GFRs), routine monitoring is costly and time consuming. We studied 26 paediatric patients who were receiving chemotherapy that included 500–600 mg/m² of carboplatin per course. ⁵¹Cr-EDTA GFRs were measured initially and after one to seven courses (median four). There was no measurable difference between renal function before and after carboplatin (P = 0.8). Our study shows that routine monitoring of renal glomerular function is unnecessary. Carboplatin use in patients who have had unilateral nephrectomy as part of their treatment is also discussed. Paediatric oncology literature concerning nephrotoxicity and carboplatin is reviewed. © 1993 Wiley-Liss, Inc.     

Decline in ventricular function as a result of general anesthesia in pediatric heart transplant recipients

Echocardiography is frequently performed under anesthesia during procedures such as cardiac catheterization with EMB in pediatric HTx recipients. Anesthetic agents may depress ventricular function, resulting in concern for rejection. The aim of this study was to compare ventricular function as measured by echocardiography before and during GA in 17 pediatric HTx recipients. Nearly all markers of ventricular systolic function were significantly decreased under GA, including EF (?4.2% ±1.2, P < .01) and RV FAC (?0.05 ± 0.02, P = .04). Subjects in the first post‐transplant year (n = 9) trended toward a more significant decrease in EF vs those beyond the first post‐transplant year (n = 8; ?6.0% ±1.2 vs ?2.1 ± 2.0, P = .1). This information quantifies a decline in biventricular function that should be expected in pediatric HTx recipients while under GA and can assist the transplant clinician in avoiding unnecessary treatment of transient GA‐induced ventricular dysfunction.     

儿童心脏功能评估在儿童重症领域之应用

由于心脏的解剖结构与血管系统息息相关,因此心脏的功能,其实也就是心血管的功能,或者就是所谓的循环系统的功能,其实也就是血流力学的功能状态.综合言之,都可以用心血管功能或循环功能代表.在儿科重症监护室中的心脏功能评估相关应用以能快速实用为主,与一般心脏科的范畴稍有差异.准此原则,心脏功能的评估,包括基本评估以及进阶评估两大类.所谓基本评估,就是只用临床上非使用仪器的方法来做的较单纯的评估,也就是身体检查.身体检查可以侦测到肝脏肿大,外周水肿或者颈静脉怒张,心脏搏动点的位置等诸多身体的异常征象以及微血管充盈时间等,以显示心脏循环的功能以及血流力学的功能状态.至于进阶的心功能评估包括非侵袭性的方法以及侵袭性的方法.非侵袭性的方法,最常用的就是心脏超声检查,经过心脏的超声检查,可以观测心脏的收缩状态以及舒张状态,心包膜积水等,是临床上最常使用的床边检查工具.另外四腔电阻抗心电图近年来也常被用来评估心脏的输出量.侵袭性的方法通常是使用一些导管,例如(1)动脉导管:动脉血压的波形及数值.(2)中枢静脉导管:可以监测右心房的压力.(3)肺动脉楔压导管:可以监测肺动脉楔压等同于肺动脉微血管压力,或者雷同于左心房填充压,这是左心室功能的重要指标.(4)脉搏容积导管监测(PiCCO):近似于肺动脉楔压,但是可以提供更广泛的指标,除了心输出量之外还可以包括肺部水含量、胸腔液的含量等.总而言之,心脏功能/循环功能/血流力学监测等其实本身包含非常复杂的生理病理观念以及参数运算.在重症监护室的医疗人员,未必需要了解所有的细节,但是至少必须要对于一些较单纯的参数,能够在患者床边检测参数,有一些基本的了解,并且做适当的运用,才能够使危重症患者得到最好的照顾.