新型纳米根管充填材料对成骨细胞生长的影响

通过体外培养的成骨细胞,采用二甲基噻唑二苯基四唑溴盐比色法和流式细胞术对新型纳米根管充填材料(nHA-PA66)作用下的成骨细胞生长情况的变化进行研究,评价其对成骨细胞生长的影响。以该材料的细胞培养基浸提液作用于实验组细胞,对照组采用培养基本身。实验组和对照组成骨细胞的生长情况和细胞周期无显著性差异,表明该新型纳米材料对成骨细胞的生长和细胞周期无不良影响。提示新型纳米根管充填材料的成骨细胞相容性较好,具有用作根充材料的基础。     

乳腺良恶性病变的磁共振T2*W首过灌注成像与血管生成相关性研究

Objective： To study the diagnostic value of T2^＊-weighted first-pass perfusion imaging in breast tumors. Methods： We analyzed the magnetic resonance imaging （MRI） information along with the pathological and immunohistochemistry results. Magnetic resonance imaging was performed in 28 patients with breast tumor. The time to signal intensity curves were generated according to the T2^＊-weighted first-pass perfusion imaging. The curve＇s maximal signal intensity drop rate and maximal signal intensity decrease time were analyzed and compared with the pathological diagnoses after surgery. Results： Malignant breast lesions showed higher maximal signal intensity drop rate （44.69% ± 17.07 vs. 17.22% ±7.49, P 〈 0.001） than benign lesions, but there was no significant difference of maximal signal decrease time between those two lesions （23.94 s ± 4.92 vs. 20.02 s ± 6.83, P 〉 0.05）. Conclusion： The T2^＊-weighted first-pass perfusion imaging has enough sensitivity and specificity in breast tumor diagnosis.     

近红外光谱仪监测窒息新生儿听觉刺激诱发时的脑氧合代谢及脑血流变化

目的了解窒息新生儿在听觉刺激诱发脑神经活动时的脑氧合代谢和脑血流量的改变。 方法1998~2003年北京中日友好医院儿科选择窒息新生儿34例为窒息组，健康新生儿40名为对照组。使用近红外光谱仪，观察听觉刺激试验诱发的脑氧合血红蛋白\[Hb O2\]、还原血红蛋白\[Hb H\]和总血红蛋白\[Hb tot\]浓度的变化，并比较两组脑氧合代谢和脑血流量的改变。根据\[Hb O2\]、\[Hb H\]和\[Hb tot\]不同的变化，将氧合代谢曲线分为A(\[Hb O2\]、\[Hb H\]和\[Hb tot\]均增加)； B(\[Hb O2\]和\[Hb tot\]增加,\[Hb H\]降低)；C(\[Hb O2\]和\[Hb tot\]降低,\[Hb H\]增加)3种曲线类型。 结果窒息组中25例(25/34、73.5%)显示C型变化，对照组中28例(28/40、70.0%)显示A型变化，两组中A、C两型例数比较差异显著(P<0.05)。两组\[Hb O2\]和\[Hb tot\]数值变化幅度比较差异显著(P<0.05)。 结论窒息新生儿听觉刺激诱发相应皮层的神经活动时，显示局部脑血流量下降、氧合代谢降低，重度窒息儿更明显。     

利用产妇行为协助判断产程起始时间

产程图上临产起始点一直缺乏精确性。临产开始的标志是有规律且逐渐增强的子宫收缩，同时伴随进行性宫颈管消失、宫口扩大和胎先露下降。从定义上看，它是一个过程，需要客观检查，还要结合产妇对其阵痛的主观感受。因此，多年来临床上对产程起始点的判断，没有一个确切的时点，往往根据检查结果追溯产妇的主观感觉，来绘制产程图。这种传统追溯法，影响了产程的准确性和对产程图信息的利用率。     

一种较好的RNA分离制备方法及其在人胚RNA提取中的应用

以钒基核苷酸复合物为核酸酶抑制剂,从人胚组织中制备总RNA,所得产品几乎不含DNA和蛋白质,经过分离Poly(A)~ mRNA,证明制品有合成cDNA的完整功能,方法比较简捷,适于大量制备以满足分离mRNA 之需,并讨论了此法的优缺点。     

Glucocorticoids potentiate kainic acid-induced seizures and wet dog shakes

Glucocorticoid effects on kainic acid-induced motor seizures and wet dog shakes in rats were investigated by adrenalectomy and dexamethasone treatment. One-day adrenalectomy attenuated kainic acid-induced wet dog shakes and seizure activity. These effects were restored by dexamethasone. Administration of dexamethasone to non-adrenalectomized rats potentiated kainic acid-induced wet dog shakes and severity of seizure activity. These results suggest that glucocorticoids may play an important role in modulating the severity of kainic acid-induced seizures and wet dog shakes.     

肝癌多药耐药产生与低糖环境的关系

目的探讨局部微环境低糖与肝细胞癌多药耐药性(MDR)产生的关系及影响机制。方法低糖培养HepG2细胞,应用流式细胞术Annexin V/PI法检测低糖培养的细胞在化疗药物5-氟脲嘧啶(5-Fu)作用后的凋亡情况,分别应用荧光定量聚合酶链反应(PCR)技术和Western blot技术检测低糖培养后HepG2细胞内多药耐药相关基因mdr1、MRP1、LRP的mRNA和蛋白水平的表达。结果在低糖环境下生长时间越长的HepG2细胞对5-Fu的抵抗越强,而且随着低糖培养时间的增加,5-Fu诱导的HepG2细胞的凋亡高峰延迟。低糖培养的HepG2细胞内多药耐药相关基因mdr1、MRP1、LRP在mRNA和蛋白水平的表达随低糖培养时间的延长而升高,以LRP的改变最为显著。结论肝癌生长微环境葡萄糖耐量不足也是肝癌产生MDR的原因之一。低糖可通过上调一组多药耐药相关基因的表达而诱导肝癌的多药耐药性。     

老年心力衰竭患者外周血红细胞膜脂流动性的变化及与心功能的相关性

目的观察红细胞膜脂流动性（LFU）在老年充血性心力衰竭（CHF）中的变化及其意义。方法选择CHF患者40例,正常对照者30例,用荧光分光光度计偏振技术测定外周血红细胞LFU。结果CHF组红细胞LFU明显低于正常对照组（P<0.01）;心功能越差,LFU越低（P<0.05和P<0.01）。结论红细胞LFU在一定程度上反映了CHF程度。     

Nonspecific mitochondrial disease with epilepsy in children: diagnostic approaches and epileptic phenotypes

OBJECTIVES: This study sought to characterize epileptic phenotypes in children with nonspecific mitochondrial disease (MD) and to evaluate MD diagnostic approaches. METHODS: A retrospective analysis of the medical, electroencephalogram, and laboratory records of 142 patients with epilepsy was performed. The patients were evaluated for MD, and 124 patients were included in the final cohort. The MD criteria used included an oral glucose lactate stimulation test (OGLST) and urine organic acid/plasma amino acid (UOA/PAA) assays as metabolic indicators of modified Walker criteria, as suggested by Bernier et al. (Neurology 59:1406-1411, 2002). RESULTS: Twenty-two patients were classified as having definite MD (9), probable MD (5), possible MD (6), or pyruvate dehydrogenase (PDH) deficiency (3), including one patient which showed a respiratory chain (RC) defect and PDH deficiency. Seven out of eight patients in whom significant RC defects were observed showed complex I defects. In 14 patients, epileptic seizures start at infantile ages. Of 17 patients who substantially presented generalized seizures, 4 patients started with partial seizures. Five patients consistently presented only partial seizures. The OGLST and UOA/PAA assays were useful for a more precise diagnosis of MD, although low positive predictive value of the OGLST was regrettable. No patient was classified as definite MD by Walker's original criteria, but the use of our revised MD criteria resulted in the classification of nine additional patients as definite MD. CONCLUSIONS: MD manifested considerable diverse epileptic phenotypes and should be considered in the differential diagnosis of epilepsy in children with unexplained encephalomyopathy and progressive and fluctuating clinical courses.