Cardiorespiratory response to exercise after the Fontan procedure for tricuspid atresia

Noninvasive exercise testing was used to assess gas exchange in 13 patients age 6-25 yr who had undergone Fontan procedures for tricuspid atresia, five of whom had preexisting Glenn shunts. The results were compared to 28 age- and sex-matched controls. Oxygen saturation was measured by ear oximetry at rest and after exercise. Ventilation, oxygen consumption (VO2), carbon dioxide production (VCO2), and heart rate were measured during progressive exercise. The ventilatory equivalents for oxygen (VE/VO2) and carbon dioxide (VE/VCO2), mixed expired pCO2 (PECO2) end-tidal pCO2 (PETCO2), and dead space to tidal volume ratio (VD/VT) were determined during steady state exercise on a cycle ergometer. Heart rate was higher for VO2 by 15% (p less than 0.02) and ventilation was higher for both VO2 (by 37%, p less than 0.001) and VCO2 (by 27%, p less than 0.002) in the patients than the controls. Mean VE/VO2 was 35.4 +/- 7.8 (SD) compared to 25.8 +/- 3.1 (p less than 0.001) and mean VE/VCO2 was 41.7 +/- 9.0 compared to 31.6 +/- 4.3 (p less than 0.001). Mean PECO2 was 21.4 +/- 4.4 torr with controls at 27.9 +/- 3.8 (p less than 0.001) and mean PETCO2 was 33.0 +/- 5.3 torr compared to 40.0 +/- 3.3 (p less than 0.001). The patients had a mean oxygen saturation of 92 +/- 5% at rest and abnormal saturation after exercise (87 +/- 9, p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)     

长沙市2～12 岁儿童睡眠障碍流行病学调查

目的：了解长沙市2～12岁儿童的睡眠时间和睡眠障碍的发生情况,为有针对性的进行干预提供指导。方法：2006年6月~2007年4月,在长沙市5个行政区采用分层随机抽样方法调查3 756名2～12 岁儿童的睡眠情况,由专人负责对其家长进行问卷调查。结果2～12 岁儿童每天平均睡眠时间为10.60 h。从2~12岁共11个年龄组儿童的每天平均睡眠时间分别为12.26,11.57,11.33,11.26,10.95,10.64,10.62,10.45,10.28,9.83和9.61 h。2～12 岁儿童睡眠障碍总发生率为40.9%,其中睡眠时频繁鼾症发生率为8.2%,喉头哽咽1.5%,睡眠呼吸暂停0.8%,睡眠不安7.6%,张口呼吸4.9%,睡眠中多汗22.6%,睡眠中肢体抽动3.2%,磨牙9.5%,梦呓5.5%,梦游0.9%,夜间遗尿2.5%(≥5岁),不明原因睡眠中觉醒或憋醒1.9%。白天睡得多、夜间清醒者1.5%,入睡过早 2.1%,易惊醒者1.6%,睡眠中出现尖叫、哭喊者1.8%。不同症状的发生率存在性别、年龄差异。结论长沙市2～5岁年龄组儿童睡眠时间略低于儿童保健学要求的同年龄段儿童睡眠时间需求标准,长沙市2～12 岁儿童睡眠障碍发生率较高,高于其他城市的调查水平,需引起儿童保健工作者及儿童父母的重视。     

Sequential oral hydroxyurea and intravenous cytosine arabinoside in refractory childhood acute leukemia: a pediatric oncology group phase 1 study

At concentrations >0.1 mM, hydroxyurea (HU) enhances the accumulation of cytosine arabinoside (ara-C) in leukemia cells in vitro. This study of children with refractory acute leukemia was designed to take advantage of this biochemical modulation. A fixed dose of HU and an escalating dose of ara-C were used. Oral HU (1200 mg/m2) was followed 2 hours later by ara-C (250-3100 mg/m2) intravenously in 15 minutes. The combination was given on days 1, 2, 3 and 8, 9, 10. Thirty-three children [26 acute lymphocytic leukemia (ALL), 7 acute nonlymphocytic leukemia] were treated; 29 received at least 1 full course. All patients developed grade 4 cytopenias. Other grade 3 to 4 toxicities included hyperbilirubinemia (2), elevated transaminases (3), transient gait disturbance (1), stomatitis (3), typhlitis (1), nausea/vomiting (9), and marrow aplasia >4 weeks (1). Three patients had intracranial bleeds while thrombocytopenic. Only liver toxicities and nausea/vomiting exhibited any dosage effect. The maximum tolerated dose of ara-C was 2400 mg/m2. There were 6 complete responses (5 ALL), 5 partial responses (3 ALL), and 19 patients with no response or progressive disease. There was no dosage effect for response with 2 complete responses occurring at the lowest ara-C level. Responses were transient (1 to 3 mo). Twenty of twenty-six patients achieved a peak serum HU level >0.5 mM by 2 hours after the HU dose. The mean level at 2 hours was 0.57 mM (range: 0.21 to 0.99 mM). This combination of HU and ara-C is tolerable and has efficacy in refractory leukemias. Responses at the lowest ara-C dose level suggests synergism.     

Gas production by feces of infants.

BACKGROUND: Intestinal gas is thought to be the cause abdominal discomfort in infants. Little is known about the type and amount of gas produced by the infant's colonic microflora and whether diet influences gas formation. METHODS: Fresh stool specimens were collected from 10 breast-fed infants, 5 infants fed a soy-based formula, and 3 infants fed a milk-based formula at approximately 1, 2, and 3 months of age. Feces were incubated anaerobically for 4 hours at 37 degrees C followed by quantitation of hydrogen (H2), methane (CH4), carbon dioxide (CO2), hydrogen sulfide (H2S), methanethiol (CH3SH), and dimethyl sulfide (CH3SCH3) in the head-space. RESULTS: H2 was produced in greater amounts by breast-fed infants than by infants in either formula group, presumably the consequence of incomplete absorption of breast milk oligosaccharides. CH4 was produced in greater amounts by infants fed soy formula than by infants on other diets. CO2 was produced in similar amounts by infants in all feeding groups. Production of CH3SH was conspicuously low by feces of breast-fed infants and production of H2S was high by soy-formula-fed infants. CH3SCH3 was not detected. Only modest changes with age were observed and there was no relation between gas production and stool consistency, although stools were more likely to be malodorous when concentrations of H2S and/or CH3SH were high. CONCLUSIONS: Gas release by infant feces is strongly influenced by an infant's diet. Of particular interest are differences in production of the highly toxic sulfur gases, H2S and CH3SH, because of the role that these gases may play in certain intestinal disorders of infants.     

The treatment of arrhythmias in infants and children using propafenone

Antiarrhythmic treatment was required in 35 patients aged one day to 11 8/12 years (average 5 7/12 years) for one or several of the following arrhythmias: paroxysmal supraventricular tachycardia (17), ventricular extrasystole (16), ventricular tachycardia (17), ventricular extrasystole (16), ventricular tachycardia (4), junctional tachycardia (4), and atrial flutter (3). 300 mg/m2/day oral propafenone was administered in 3 to 4 divided doses. The arrhythmia in 21 of the 35 patients had been unsuccessfully treated by digoxin (6), verapamil (5), ajmalin (4), propranolol (3), spartein (1), phenytoin (1), and lidocain (1) prior to the propafenone therapy. However, the arrhythmias could be abolished or reduced in 30 patients (85.7%) by Propafenone. In 5 patients with supraventricular tachycardia (2), junctional tachycardia (2), or ventricular extrasystole (1), propafenone therapy had no effect. In two other patients propafenone led to atrioventricular conduction disturbances and had to be discontinued. Propafenone is an effective well tolerated antiarrhythmic drug without major side effects in pediatric patients.     

儿童重型再生障碍性贫血Th1/Th2细胞相关因子表达研究

目的利用流式细胞术探讨儿童重型再生障碍性贫血(简称"再障")患儿体内Th1和Th2细胞相关因子白细胞介素-2(IL-2)、白细胞介素4(IL-4)、白细胞介素-10(IL-10)和干扰素-γ(IFN-γ)的变化特点。方法 2014年11月至2015年8月,在郑州大学第一附属医院诊治的30例初诊重型再障患儿,同时选择正常体检儿童20名为对照组,采取其静脉血,分别用流式细胞术测定所取血样标本中IL-2、IL-4、IL-10和IFN-γ的含量。并用独立样本t检验的统计分析方法分析两组儿重外周血中上述4种细胞因子的差异是否有统计学意义,用ROC曲线评价上述4种细胞因子对于诊断重型再障的临床意义。结果(1)重型再障患儿外周血中IL-2、IFN-γ浓度分别为7.56±5.93(pg/mL)、8.67±3.72(pg/mL),均高于对照组的4.45±2.94(pg/mL)、4.89±2.86(pg/mL),差异具有显著性(P0.05);IL-4、IL-10浓度分别为4.48±3.28(pg/mL)、9.00±3.60(pg/mL).均低于对照组的7.36±7.02(pg/mL)、10.93±5.13(pg/mL),但差异无显著性(P0.05)。(2)重型再障患儿外周血中IL-2 ROC曲线下面积(AUC)为0.746(95%CI 0.697~0.816),具有中度诊断价值;IL-4的AUC为0.662(95%CI 0.597~0.716),为低诊断价值;IL-10的AUC为0.616(95%CI 0.458~0.774),为低诊断价值;IFN-γ的AUC为0.817(95%CI 0.697~0.978),具中度诊断价值。结论 IL-2、IFN-γ为负调控造血因子,参与再障发病机制,但是Th1和Th2细胞相关因子(IL-2、IFN-γ和IL-4、IL-10)的表达水平高低,对于儿童获得性再障的诊断价值比较有限,     

Reoxygenation with 100 or 21% oxygen after cerebral hypoxemia-ischemia-hypercapnia in newborn piglets

We tested if reoxygenation with 100% O(2) was superior to 21% O(2) after combined cerebral hypoxemia-ischemia-hypercapnia (HIH) in newborn piglets. Twenty-eight piglets were randomized to reoxygenation with 100 or 21% O(2) following asphyxia. Asphyxia was induced by ventilation with 8% O(2), adding CO(2), and temporary occlusion of both common carotid arteries. After 20 min, reoxygenation-reperfusion was started with 21% O(2) (HIH 21% group, n = 13) or 100% O(2) (HIH 100% group, n = 11) for 30 min followed by 21% O(2). All piglets were observed for 2 h. We measured mean arterial blood pressure (MABP), changes in microcirculation in the cerebral cortex (laser Doppler), and extracellular concentrations of hypoxanthine in the cortex and amino acids in the striatum (microdialysis). We found significantly higher MABP and better restoration of microcirculation after reoxygenation with 100% compared with 21% O(2), but no differences in biochemical markers were found between the groups. This indicates that the brain tolerated reoxygenation with 21% as well as with 100% O(2) in the present model of experimental asphyxia in spite of the differences in MABP and cerebral microcirculation.     

Maturation of calcium transport in cardiac sarcoplasmic reticulum

Developmental changes in myocardial function have been described by a number of investigators. To further define the cellular basis for these changes, the present study was designed to characterize age-related changes in Ca2+ transport in sarcoplasmic reticulum (SR) vesicles isolated from six groups of sheep: group (Sp) I (100-105 days gestation), Gp II (128-132 days gestation), Gp III (postnatal, 0-3 days), Gp IV (4 wk), Gp V (8 wk), and Gp VI (maternal sheep). The maximal Ca2+ uptake for vesicles isolated from Gp I-V was significantly (p less than 0.01) decreased as compared to that measured for Gp VI (maternal) vesicles. However, Ca2+-dependent ATP hydrolysis was decreased only in the fetal SR vesicles (Gp I-II). Thus, decreased ATP hydrolysis only partially explained the decreased Ca2+ uptake. In contrast, calculation of apparent Ca2+ pump coupling ratios (mol of Ca2+ transported/mol of ATP hydrolyzed) showed that there was a marked increase in the coupling of Ca2+ transport to ATP hydrolysis during maturation of the heart. Inasmuch as the contractile state of the heart depends on precise regulation of Ca2+ concentration by the SR, these age-related changes in SR function may contribute to developmental changes in myocardial function.     

Effects of alterations of inspiratory and expiratory pressures and inspiratory/expiratory ratios on mean airway pressure, blood gases, and intracranial pressure

Twenty neonates requiring mechanical ventilation for respiratory failure, including 13 with hyaline membrane disease, were studied to assess the effects of alterations in ventilator settings on mean airway pressure (MAP), blood gases, and intracranial pressure (ICP). The study involved random alterations in peak inspiratory pressure (PIP), positive end-expiratory pressure (PEEP), and inspiratory/expiratory ratio while MAP, PaO2, ICP, and end-tibal PCO2 were continuously monitored. The results showed a significant relationship between MAP and PaO2 that was expressed as the change in PaO2 per millimeter of mercury change in MAP (delta PaO2/delta MAP) with a mean delta PaO2/delta MAP of 4.92. The delta PaO2/delta MAP was highest for changes in PEEP (6.08), followed by PIP (5.07), and inspiratory/expiratory ratio (1.9). There was a significant relationship between alterations in PEEP and PIP vs PaCO2 and pH. Increases in PEEP and decreases in PIP resulted in an elevated PaCO2 and a lowered pH, and decreases in PEEP and increases in PIP resulted in a decreased PaCO2 and an elevated pH. There was no significant relationship between MAP and ICP, but there was a significant association between delta ICP and delta PaCO2 during alterations in PIP (r = .64, P less than .001). Increases in PEEP will lead to the greatest increase in PaO2 per change in MAP, followed by increase in PIP and inspiratory/expiratory ratio using a pressure-limited ventilator.     

小儿先天性肺动脉吊带畸形6例临床及诊断分析

目的探讨小儿先天性肺动脉吊带畸形的临床诊断方法。方法回顾分析广州儿童医院1993~2004年收治的肺动脉吊带畸形的婴幼儿6例,采用X线胸片、超声心动图、CT、心血管造影、磁共振、食管吞钡、支气管镜等方法综合检查,其中4例有手术或尸检资料。结果初诊6例全部漏诊,4例经复查确诊(2例术前确诊),1例在术中发现,另1例由尸检发现。6例中超声心动图检出4例;由临床和超声疑诊为肺动脉吊带畸形,高速螺旋CT(n=4)和心血管造影(n=2)诊断符合率100%。结论婴儿早期即出现反复呼吸困难、喘鸣、肺部感染应考虑先天性肺动脉吊带畸形的可能。CT、心血管造影、超声心动图可明确诊断。     

宫内生长受限大鼠肝脏磷酸肌醇-3-激酶信号通路分子的变化

目的：研究宫内生长受限(IUGR) 成年子鼠肝脏中受体后胰岛素信号传导通路分子的表达变化,探讨IUGR个体发生2型糖尿病的分子机制。方法：通过低蛋白饮食法建立大鼠IUGR模型,采用Western blot检测雄性子鼠（8周）基础状态下肝脏中胰岛素受体底物（IRS）2、磷酸肌醇-3-激酶（PI-3K）、糖原合成酶激酶（GSK）3β的蛋白表达水平,以及胰岛素刺激后蛋白激酶B（PKB）的磷酸化水平变化。结果：基础状态下,IUGR成年子鼠肝脏IRS-2的蛋白表达与正常对照差异无显著性,PI-3K的催化亚单位p110的蛋白表达比对照组明显降低;而GSK-3β蛋白含量比对照组明显增加,差异均有显著性（P<0.01）。基础状态和胰岛素刺激状态下,IUGR组肝脏PKB和磷酸化的PKB-Ser473表达水平都明显低于对照组（P<0.01）,胰岛素刺激后,对照组肝脏磷酸化的PKB-Ser473表达明显增加,是基础状态的182%（P<0.01）,而IUGR组肝脏磷酸化的PKB-Ser473的增加幅度较小,仅是基础状态的123%（P<0.05）。结论：宫内蛋白营养不良造成的IUGR鼠机体胰岛素抵抗的发生可能与肝脏中PI-3K和其下游靶蛋白PKB的表达和活性降低,以及GSK-3β的表达增高有关。［中国当代儿科杂志,2009,11（3）：221-224］     

Selective inhibitors differentially affect cyclooxygenase-dependent pial arteriolar responses in newborn pigs

Cyclooxygenase (COX)-derived prostanoids play an important role in the cerebrovascular control of newborns. In humans and in the widely accepted model of piglets, both the COX-1 and the COX-2 isoforms are expressed in cerebral arteries. However, the involvement of these isoforms in cerebrovascular control is unknown. Therefore we tested if specific inhibitors of COX-1 and/or COX-2 would differentially affect pial arteriolar responses to COX-dependent stimuli in piglets. Anesthetized, ventilated piglets (n = 35) were equipped with a closed cranial window, and changes in pial arteriolar diameters (baseline approximately 100 microm) to hypercapnia (ventilation with 5-10% CO(2), 21% O(2), balance N(2)), arterial hypotension (40 mm Hg MABP achieved by blood withdrawal), and Ach (Ach, 10-100 microM) were determined via intravital microscopy. Arteriolar responses were repeatedly tested 15 min after IV administration of selective COX-1 and COX-2 inhibitors SC-560 and NS-398 (1-1 mg/kg), and nonselective inhibitors indomethacin (0.3-1 mg/kg), acetaminophen (30 mg/kg), and ibuprofen (30 mg/kg). Hypercapnia resulted in concentration-dependent, reversible, (approximately 20-40%) increases in pial arteriolar diameters that were unaffected by NS-398, SC-560, acetaminophen and ibuprofen. In contrast, 0.3 mg/kg indomethacin significantly reduced, 1 mg/kg virtually abolished the vasodilation. Arterial hypotension elicited (approximately 15-20%) vasodilation that was similarly reduced by NS-398 and indomethacin but was unaltered by SC-560. Ach dose-dependently constricted pial arterioles. This response was similarly attenuated by NS-398, indomethacin, and ibuprofen, but left intact by SC-560. We conclude that the assessed COX-dependent vascular reactions appear to depend largely on COX-2 activity. However, hypercapnia-induced vasodilation was found indomethacin-sensitive instead of a COX-dependent response in the piglet.     

Speed and profile of the arterial peripheral chemoreceptors as measured by ventilatory changes in preterm infants.

To measure the response time of the peripheral chemoreceptors, we studied 13 preterm infants [birth weight 1602 +/- 230 g (mean +/- SEM); gestational age 31 +/- 1 wk; postnatal age 15 +/- 1 d] during inhalation of 21% O2 (15 +/- 5 s) followed by 100% O2 (1 min). We used a flow-through system to measure ventilation and gas analyzers to measure alveolar gases. Hypoventilation was observed at 3.6 +/- 0.6 s and was maximal at 6.8 +/- 1 s after O2 began. This maximal response was always associated with an apnea (greater than 3 s). Alveolar PO2 increased from 13.5 +/- 0.1 kPa (101 +/- 0.8 torr) (control) to 28.0 +/- 1.2 kPa (210 +/- 9 torr) (1st O2 breath), to 42.0 +/- 2.4 kPa (315 +/- 18 torr) (1st hypoventilation), to 45.9 +/- 4.1 kPa (344 +/- 31 torr) (breath preceding maximal response), and to 53.6 +/- 4.1 kPa (402 +/- 31 torr) (at maximal response). Minute ventilation was 0.192 +/- 0.011 (control), 0.188 +/- 0.011 (1st O2 breath), 0.088 +/- 0.016 (1st hypoventilation; p less than 0.0001), 0.122 +/- 0.016 (breath preceding maximal response; p less than 0.0002), and 0.044 +/- 0.011 L/min/kg at maximal response (p less than 0.0001). This decrease in ventilation was due to a decrease in frequency with no appreciable change in tidal volume. The initial period of hypoventilation (19 +/- 4 s) was followed by a breathing interval (10 +/- 2 s) and a second period of hypoventilation (14 +/- 3 s) before continuous breathing resumed.(ABSTRACT TRUNCATED AT 250 WORDS)     

�����Ķ�ͼԤ��С�������������йرյļ�ֵ

目的探讨简易的超声心动图指标预测动脉导管开放(PDA)新生儿及婴儿日后动脉导管自行关闭的可能性及临床意义。方法对新生儿及婴儿期经彩色多普勒超声心动图证实的PDA患儿56例(其中早产儿8例,低出生体重儿18例)进行3、6、9和12个月随访观察,初诊年龄1-33(15.8±12.3)d。观察指标包括二维超声心动图测量的PDA最小直径(MD2DE),彩色多普勒血流显像测量的PDA分流束宽度(W JCDFI),并评估超声心动图指标对预测患儿1周岁时PDA自行关闭的价值。PDA关闭的判断标准为彩色多普勒血流显像无异常分流且频谱多普勒超声未能探及连续性分流频谱。结果随访过程中,随访3、6、9和12个月的PDA自行关闭率分别为23.2%、30.4%、32.1%和32.1%。若分别以首次测量的MD2DE≤3mm和≤2mm以及M JCDFI≤3mm和≤2mm为界限,则12个月随访结束时2种测量技术4项测量指标预测PDA关闭的敏感性为46.9%、80.0%、65.0%和83.3%(P<0.05),特异性为87.5%、94.4%、86.1%和81.9%(P<0.05),阳性预测值为83.3%、88.9%、72.2%和55.5%(P<0.05),阴性预测值为55.3%、89.5%、81.6%和81.8%(P<0.05),准确性为64.3%、89.3%、78.6%和82.1%(P<0.05)。结论简易超声心动图指标可较好地预测未闭动脉导管自行闭合的可能性,对患儿是否选择早期干预措施具有指导价值。     

The relationship between electrocerebral activity and cerebral fractional tissue oxygen extraction in preterm infants

Impaired cerebral oxygen delivery may cause cerebral damage in preterm infants. At lower levels of cerebral perfusion and oxygen concentration, electrocerebral activity is disturbed. The balance between cerebral oxygen delivery and oxygen use can be measured by near-infrared spectroscopy (NIRS), and electrocerebral activity can be measured by amplitude-integrated EEG (aEEG). Our aim was to determine the relationship between regional cerebral tissue oxygen saturation (rcSO2), fractional tissue oxygen extraction (FTOE), and aEEG. We recorded longitudinal digital aEEG and rcSO2 prospectively in 46 preterm infants (mean GA 29.5 wk, SD 1.7) for 2 hr on the 1st to 5th, 8th, and 15th d after birth. We excluded infants with germinal matrix hemorrhage exceeding grade I and recordings of infants receiving inotropes. FTOE was calculated using transcutaneous arterial oxygen saturation (tcSaO2) and rcSO2 values: (tcSaO2 - rcSO2)/tcSaO2. aEEG was assessed by calculating the mean values of the 5th, 50th, and 95th centiles of the aEEG amplitudes. The aEEG amplitude centiles changed with increasing GA. FTOE and aEEG amplitude centiles increased significantly with postnatal age. More mature electrocerebral activity was accompanied by increased FTOE. FTOE also increased with increasing postnatal age and decreasing Hb levels.     

Implanted vascular access devices (ports) in children: complications and their prevention

Implanted vascular access devices (ports) play a major role in the management of children with cystic fibrosis (CF) and many haematological conditions. With the expanding use of ports, new and more frequent complications are being encountered. To retrospectively review the complications associated with ports, the case notes of all patients who underwent insertion of a port between 1997 and 2000 were analysed. Details of the underlying disorder, type of vascular device, nature of use, and complications were recorded; 55 ports were inserted in 41 patients (a second port was required in 12, a third port in 2) during this period. Their underlying diagnoses were CF (11), haemophilia (4), haemolytic anaemias (2), immunological disorders (6), solid neoplasms (8), and leukaemia (10). Thirteen ports (24%) were removed and replaced for various complications: infection (2), blockage (4), leak (2), dislodgement (2), and malposition (3). Including four port-related problems managed conservatively (3 access problems managed by change in access technique; 1 blockage managed by urokinase), the over all complication rate was 31%. Ports thus have a high complication rate with long-term use. Selecting the right port system, proper installation of the port chamber, and efficient handling and maintenance by trained staff could prevent the vast majority of port-related complications. Accepted: 4 January 2001     

卡维地洛对心力衰竭时兰尼碱受体的作用

目的探讨卡维地洛对心力衰竭（heart failure,HF）（简称心衰）时兰尼碱受体／钙释放通道（ryanodine receptor,RyR）的作用。方法采用腹主动脉缩窄术建立幼鼠心衰模型,术后6周随机分为2组：心衰组和卡维地洛治疗组。另设假手术对照组。卡维地洛灌胃给药,术后每日观察幼鼠的呼吸、皮毛颜色、活动量、体重等发育状况。4周后行高频超声检测。超速离心分离肌质网（SR）,荧光分光光度仪检测钙离子（Ca^2＋）的重吸收和渗漏。结果与假手术组（n=20）比较,HF组（n=20）幼鼠左室舒张末期内径（LVEDD）（P〈0．05）、左室收缩末期内径（LVESD）、室间隔舒张末期厚度（IVSTd）、室间隔收缩末期厚度（IVSTs）、左室后壁舒张末期厚度（LVPWTd）、左室后壁收缩末期厚度（LVPWTs）均明显升高（P〈0．01）,短轴缩短率（FS）、射血分数（EF）均明显降低（P〈0．01）;与HF组比较,卡维地洛治疗组（n=20）LVEDD（P〈0．05）、LVESD、IVSTd、IVSTs、LVPWTd、LVPWTs均明显降低（P〈0．01）,FS、EF均明显升高（P〈0．01）。若分别向含有三组SR的缓冲液中仅加入SRCa^2＋-ATP酶抑制剂-毒胡萝卜内酯（thapsigargin）,HF组较假手术组、卡维地洛治疗组有明显的Ca2＋渗漏（P〈0．01）;若毒胡萝卜内酯和FKBP抑制剂-FK506一起加入三组SR缓冲液中,假手术组、卡维地洛治疗组、HF组均出现明显的Ca2＋渗漏（P〈0．01）;与仅加入毒胡萝卜内酯比较,假手术组和卡维地洛治疗组的Ca2＋渗漏明显增多（P〈0．01）,HF组的Ca2＋渗漏未见明显增加（P〉0．05）。结论HF时心肌Ca2＋渗漏明显,卡维地洛通过恢复HF时心肌RyR FKBPl2．6的结合,从而抑制Ca2＋的渗漏。提高心脏功能并有效抑制心室重塑。     

Fibreoptic bronchoscopy without general anaesthetic.

We have used flexible fibreoptic bronchoscopy using sedation and local anaesthesia in 50 children aged 2-19 years (median 10) using an Olympus BFP20 instrument. Indications were opportunistic pneumonias (n = 11), persistent atelectasis (n = 11), recurrent pneumonia (n = 7), miscellaneous lower airway disease (n = 7), recurrent wheezing (n = 3), haemoptysis (3), to diagnose infection or rejection of heart-lung transplants (n = 3), stridor (n = 2), suspected airway compression (n = 1), evaluation of tracheostomy (n = 1), and suspected foreign body (n = 1). In 43 cases (86%) the diagnosis was related to the primary indication. In five (10%) unrelated abnormalities were found, and five (10%) were normal. In 13 (26%) treatment was altered as a result of flexible fibreoptic bronchoscopy. Complications were transient respiratory arrest (n = 2), hypoxia (n = 2), pneumonia (n = 2), and laryngospasm (n = 1). All complications were followed by complete recovery. Our results suggest that flexible fibreoptic bronchoscopy is safe. Advantages over rigid bronchoscopy include greater visual range, fewer complications, and the avoidance of a general anaesthetic. Though invasive it can yield important diagnostic and therapeutic information.     

Bradykinin as a major endogenous regulator of endothelial function

Healthy vascular endothelium is a powerful generator of nitric oxide (NO), prostacyclin (PGI2), prostaglandin E2 (PGE2), and plasminogen activator (t-PA). These endothelial products protect vascular wall against aggression from activated blood platelets and leukocytes. In particular they protect against thrombosis, promote thrombolysis, maintain tissue perfusion, and inhibit remodeling of vascular and cardiac walls. Endothelial dysfunction appears on one hand as suppression in the release of the above mediators, and on the other as deleterious discharge of prostaglandin endoperoxides (PGH2, PGG2), superoxide anion O2-, peroxynitrite (ONOO-), and plasminogen activator inhibitor (PAI-1). Our data point to endothelial bradykinin (Bk) as a trigger for protective endothelial mechanisms. In cultured endothelial cells (CEC) Bk through kinin B2 receptors raised in a concentration-dependent manner (1pM-10 nM) free cytoplasmic calcium ions [Ca2+]i. This rise was accompanied by the release of NO as quantified by a porphyrinic sensor. Other endothelial agonists were weaker-stimulators of [Ca2+]i than Bk. In vivo we analyed the effects of exogenous Bk and of amplifiers of endogenous Bk, such as perindopril and quinapril ("tissue type" angiotensin converting enzyme inhibitors, ACE-I) on endothelial function using our original thrombolytic bioassay and EIA assays for 6-keto-PGF1alpha and t-PA antigen. A major difference found between exogenuous Bk and endogenous Bk (that rendered by "tissue ACE-I") was a) prolonged thrombolytic action (> 4h) of quinapril or perindopril. Moreover, only exogenous Bk evoked an immediate and profound hypotensive action. In vivo, Bk-induced thrombolysis was B2 kinin receptor-dependent, PGI2-mediated. The unexpected action of Bk came to light in CEC. Then appeared incubated for 4 h increased expression of mRNAs for haemoxygenase (HO-1), cyclooxygenase 2 (COX-2), prostaglandin E synthase (PGE-S), but hardly for nitric oxide synthase 2(NOS-2). We hypothesize that a network of interactions of Bk-induced enzymes may constitute a delayed phase of Bk effects in the endothelium, whereas the primary phase would be activation by BK of [Ca2+]i-dependent constitutive endothelial enzymes. In blood-perfused rat endotoxemic lungs, NO is the most eminent cytoprotective mediator. Summing up, in peripheral circulation endogenous Bk is the most efficient activator of protective endothelial function. Thrombolytic action of "tissue-type" ACE-Is relies on receptor B-2-mediated, [Ca2+]i-dependent release of PGI2. Bk also may act as a "microcytokine" by inducing mRNAs for HO-1, COX-2, or PGE-S. Activation of HO-1 may lead to a deficiency in intracellular heme required as a cofactor for both COX and NOS. This network of interactions triggered by Bk call for further studies.     

Colonic atresia: surgical management and outcome

Colonic atresia (CA) is a very rare cause of intestinal obstruction, and little information has been available about the management and predictors of outcome. A retrospective clinical trial was performed to delineate the clinical characteristics of CA with special emphasis on surgical treatment and factors affecting outcome. Children with CA who were treated in our department between 1977 and 1998 were reviewed: 14 boys and 4 girls aged 1 day to 5 months. All but 2 referred patients and 1 with prenatal diagnosis presented with intestinal obstruction. Plain abdominal X-ray films showed findings of intestinal obstruction in 14 cases; a barium enema demonstrated a distal atretic segment and microcolon in 4. The types of atresia were IIIa (n=9), I (n=6), and II (n=3). Type IIIa atresias were located proximal to the splenic flexure (n=8) and in the sigmoid colon (n=1), type I atresias were encountered throughout the colon; and all type II atresias were proximal to the hepatic flexure. Associated anomalies were multiple small-intestinal atresias (MSIA) (n=4), gastroschisis (GS) (n=2), pyloric atresia (n=1), Hirschsprung's disease (n=1), and complex urologic abnormalities (n=1). The initial management was an enterostomy in 15 patients (83%), including 2 referred and 2 with GS, and primary anastomosis in the remaining 3 (17%). Secondary procedures were the Santulli operation (n=2), colostomy closure and recolostomy followed by a Swenson operation (n=1), sacroabdominoperineal pull-through (n=1), and colostomy closure (n=1). Leakage was encountered in all primarily anastomosed patients. The overall mortality was 61%. Deaths occurred in patients with associated major anomalies (GS 2, MSIA 3, pyloric atresia 1) (55%) and in 3 patients who were initially managed by primary anastomosis (27%). Two additional patients died of sudden infant death syndrome (18%). Type I atresia was more common than in previously reported series and was associated with proximal multiple atresias. The initial management of CA should be prompt decompression of the intestine by an ostomy procedure, preferably end- or double-barrel. The type of surgery (primary anastomosis without prior colostomy) and associated abnormalities are the major determinants of poor outcome. Accepted: 19 December 2000