Cardiac biopsy in childhood

Endomyocardial biopsy was attempted in 18 children aged 5 months to 15 years with 82% success. Biopsies obtained from 15 children were examined by light and electron microscope making positive morphological diagnoses in 3 cases. The biopsy findings were actively helpful in 7 other cases, which contrasts with experience in adult biopsy series. This is a low risk procedure which does not add to the hazards of cardiac catheterization in children.     

Prolonged QT interval and cardiac arrhythmias in two neonates: sudden infant death syndrome in one case

Two neonates with arrhythmias and the long QT syndrome are described. The arrhythmias were detected in utero and both infants were apparently well after birth. The first infant, although well, had a bradycardia for the first 9 days of life. A normal heart rate was documented at 10 days but a prolonged QT interval was not appreciated on the ECG. He was discharged from hospital but died suddenly and unexpectedly 3 days later. A post-mortem examination failed to find a cause for his death which therefore fell into the category of the sudden infant death syndrome (SIDS). A retrospective analysis of the perinatal electrocardiogram showed a probable junctional rhythm with 2:1 conduction to the ventricle; the QT interval was prolonged at 0.52 seconds (QTC = 0.63). The second infant had a QT interval of 0.52 seconds (QTC = 0.54) and frequent ventricular premature beats on a 24-hour electrocardiogram. She was treated with propranolol and remains well 2 years later. Sudden infant death has often been described in the siblings of children with the long QT syndrome and one other report described a case of SIDS which was said to have had a prolonged QT interval on the perinatal ECG. This report, however, provides unquestionable evidence, in one case, of an association between the long QT syndrome and SIDS.     

13Carbon mixed triglyceride breath test and pancreatic enzyme supplementation in cystic fibrosis

Children with cystic fibrosis have variable degrees of exocrine pancreatic insufficiency which, if untreated, is the main cause of fat malabsorption. The impact of pancreatic enzyme supplementation on fat digestion was measured in 41 children with cystic fibrosis, 11 healthy controls, and five children with mucosal diseases by a non-invasive test of intraluminal lipolysis using 13carbon (13C) labelled mixed triglyceride (1,3-distearyl, 2[13C] octanoyl glycerol). The children with cystic fibrosis without pancreatic supplements had a median (range) 13C cumulative percentage dose recovered over six hours (cPDR) of 3.1% (0-31.7), the controls 31.0% (21.8-41.1), and the subjects with mucosal disease 27.8% (19.7-32.5). In 23 subjects with cystic fibrosis the usual dose of pancreatic enzyme supplements increased the cPDR to a median of 23.9% (0-45.6), and twice the usual dose of enteric coated microspheres increased the cPDR to 31.1% (11.1-47.8). There was no significant difference between the median cPDR of normal controls and children with mucosal disease, but there was a highly significant difference between these groups and children with untreated cystic fibrosis. Thirteen children with cystic fibrosis had no 13C recovery in their breath without enzymes and 10 showed marked increases with regular enzymes. In eight children doubling the dose of enzymes caused no or minimal improvement. The mixed triglyceride breath test offers a simple, non-invasive way of assessing the need for pancreatic enzyme supplementation in children with cystic fibrosis and could be used to optimise treatment.     

Human milk as a carrier of biochemical messages

Not only does breast milk provides an ideal nutrient composition for the newborn, but it also contains a variety of substances that may actively influence growth and development of the infant and stimulate neonatal protection against gastrointestinal diseases. Hormones, growth factors, cytokines and even whole cells are present in breast milk and act to establish biochemical and immunological communication between mother and child. In addition, milk nutrients such as nucleotides, glutamine and lactoferrin have been shown to influence gastrointestinal development and host defense. The unique properties of milk as a mediator of biochemical messages will be presented and the clinical significance of breastfeeding in the prevention of neonatal gastrointestinal diseases will be discussed.     

纤维粘连蛋白基因多态性与尘肺易感性的研究

目的 探讨纤维粘连蛋白(FN)4个基因位点多态性与尘肺发病的关系.方法 以确诊的128例汉族男性Ⅰ期尘肺患者作为病例组,选择与病例组年龄相差不超过5岁、同性别、同民族、开始接尘时间及累积接尘工龄相差不超过2年、在同一车间或同一采掘工作面工作的非尘肺接尘工人为对照.采Ⅲ聚合酶链反应-限制性片断长度多态件分析(PCR-RLFP)的方法 检测FN基因HaeⅢb、Msp Ⅰ、HindⅢ、Taq Ⅰ b位点的基因型.结果 病例组携带Msp Ⅰ野牛基因型(CC)频率和等位基C的分布频率分别为10.9%和41.8%,明显高于对照组(分别为3.9%和31.2%),差异有统计学意义(P<0.05).病例组携带HaeⅢb野生基因型(AA)的频率为24.2%,明显高于对照组(17.9%),差异行统计学意义(P<0.05);病例组HaeⅢbA等位基因频率为51.9%,明显高于对照组(42.2%),差异有统计学意义(P<0.05).病例组和对照组Taq Ⅰb位点基因型和Hind Ⅲ位点基因型的分布频率比较,筹异均无统计学意义(P>0.05).病例组同时携带Msp Ⅰ cc和HaeⅢbAA基因型的频率明显高于对照组,差异行统计学意义(P<0.05).结论 携带FN Msp Ⅰ cc和Hae Ⅲ b AA基冈型的接尘工人患尘肺的危险性增加,同时携带这2种基因型的接尘工人更易患尘肺.未发现FN Taq Ⅰ b和HindⅢ位点基因多态性与尘肺易感性有关.     

硫酸锌对高脂喂养载脂蛋白E基因敲除小鼠主动脉基质金属蛋白酶-9和CD40表达的影响

目的探讨硫酸锌对高脂喂养载脂蛋白E（ApoE）基因敲除小鼠血脂和氧化低密度脂蛋白（oxLDL）水平,及主动脉中基质金属蛋白酶9（MMP-9）和细胞分化抗原40（CD40）mRNA表达的影响。方法 AopE基因敲除小鼠连续14周喂饲高脂饲料,同时分别给予小鼠浓度为2.5、25 mmol/L硫酸锌水溶液作为低剂量组和高剂量组。测定小鼠血脂和oxLDL水平,并测定主动脉中MMP-9和CD40 mRNA表达水平。结果低剂量组和高剂量组小鼠血清中甘油三酯和oxLDL水平明显低于动脉粥样硬化（AS）模型组（P〈0.01）。低剂量组和高剂量组小鼠主动脉MMP-9 mRNA和CD40 mRNA水平与AS模型组没有差异。结论补充硫酸锌降低了AS模型动物的甘油三酯和oxLDL水平,具有潜在的抗AS作用,但对主动脉MMP-9和CD40 mRNA表达无影响。     

应用荧光DDRT-PCR初探低剂量的ECPs诱导细胞适应性反应的机理

[目的]用荧光DDRT-PCR技术寻找低剂量环境化学污染物(ECPs)过氧化氢(H_2O_2)、甲醛(FA),三氯乙烯(TCE)诱导细胞适应性反应差异表达的基因,为进一步研究低剂量的环境化学污染物(ECPs)诱导机体的生物学效应及其机理提供科学依据。[方法]依据H_2O_2、FA、TCE对细胞毒性的剂量反应关系,建立适应性反应的模型。然后用荧光DDRT-PCR寻找对照组、低剂量组、高剂量组,适应性反应组差异表达的基因,并鉴定和验证部分差异表达的基因。[结果]按照对照组、低剂量组、高剂量组、适应性反应组处理细胞后,DDRT-PCR结果显示各处理组与对照组比较:H_2O_2有60个差异条带、FA有61个,TCE有52个。选择差异比较明显的条带进行2次PCR,然后通过进一步克隆、测序、同源性比较发现一些已知基因如BCL-2、EIF3S5、NDUFS4、RPS10等。[结论]低剂量环境化学污染物诱导机体的适应性反应可能有维持细胞稳态、抗氧化系统、DNA损伤修复级激活细胞信号分子等过程的参与。     

食管鳞癌患者外周血T淋巴细胞亚群的变化

目的研究食管鳞癌患者外周血T淋巴细胞亚群的变化特点。方法采用流式细胞技术，对108例食管鳞癌患者（食管鳞癌组）术前检测其外周血T淋巴细胞亚群水平，并与50例健康献血者（对照组）对比，分析食管鳞癌患者T淋巴细胞亚群的变化特点。结果（1）与对照组比较，食管鳞癌组患者外周血CD3^＋ 、NK细胞水平差异无统计学意义（P=0．890；P=0．320）；CD4^＋和CD8^＋水平显著增高（P=0．001；P〈0．001），由于CD8^＋增高的程度大于CDZ增高的程度，使得CDgCDs~较对照组降低（P〈0．001）。（2）早期食管鳞癌患者外周血CD4^＋/CD8^＋低于对照组，但差异无统计学意义（P=0．112）；中晚期食管鳞癌患者CDgCDs~进一步降低，与对照组比较差异有统计学意义（P〈0．001），但与早期食管鳞癌患者相比，差异无统计学意义（P=0．218）。（3）有淋巴结转移食管鳞癌患者CD4^＋和CD4^＋/CD8^＋均低于无淋巴结转移患者（P均〈0．001），CD8^＋和NK细胞均高于无淋巴结转移患者，差异均有统计学意义（P=0．002；P=0．005）。结论食管鳞癌患者存在免疫功能低下，随着肿瘤的进展免疫功能进一步受到削弱；监测CD4^＋/CD8^＋的变化可作为食管鳞癌病情进展的标志之一。     

Ankle: surface coil MR imaging at 1.5 T

High-field surface coil magnetic resonance (MR) images were obtained of 12 ankles: two from healthy volunteers, seven from patients, and three from fresh cadavers. The cadaver ankles were sectioned in the coronal, sagittal, and axial planes for direct comparison with the MR images. Plain film confirmation of pathologic conditions was obtained in all patients, and five underwent arthroscopy or surgery, or both. MR imaging provided excellent delineation of ligaments and cartilaginous structures in all cases.