荧光原位杂交法快速鉴定血培养阳性葡萄球菌的临床应用

目的快速鉴定血培养中的金黄色葡萄球菌和凝固酶阴性葡萄球菌(CoNS),结合临床快速判定是否为污染菌。方法采用荧光原位杂交法鉴定血培养中的金黄色葡萄球菌和CoNS,杂交结果若为CoNS,根据临床资料进行判断,并与文献推荐的污染判断法进行结果比较。结果探针的特异性经由标准菌株和临床分离菌株证实。金黄色葡萄球菌探针的特异性和敏感性均为100%,GoNS探针的特异性和敏感性分别为100%和95.5%。179株CoNS中117株判断为污染菌,污染率为68%,与文献推荐的污染判断方法一致。结论荧光原位杂交法适用于血培养中的金黄色葡萄球菌和CoNS的快速鉴定,以排除CoNS污染。     

偏头痛大鼠脑内5-羟色胺1F和诱导型一氧化氮合酶基因的表达变化及针刺的干预效应

目的:前期实验已证实针刺治疗偏头痛疗效优越。观察针刺对偏头痛大鼠脑内5-羟色胺1F和诱导型一氧化氮合酶mRNA表达的调控作用。方法:实验于2005-11/2006-05在中南大学湘雅医院中西医结合研究所实验室完成。①选用SD大鼠40只,按随机数字表法分为4组(n=10),除正常对照组外,其余3组均复制大鼠偏头痛模型。模型对照组只造模,不作其他处理;针刺治疗组造模后进行针刺;针刺预防组针刺后造模电刺激20min。针刺方法:针刺大鼠双侧太冲、阳陵泉穴20min。采用疏密波,电流强度0.3～0.6mA,留针20min,1次/d,共5次。②实验完毕后取脑干及三叉神经节匀浆,采用反转录-聚合酶链反应法测定5-羟色胺1F和诱导型一氧化氮合酶mRNA表达。结果:进入结果分析正常对照组10只,模型对照组、针刺治疗组、针刺预防组各9只,共脱失3只。①与正常对照组比较,模型对照组大鼠诱导型一氧化氮合酶mRNA表达显著增强(P<0.01),5-羟色胺1FmRNA表达显著减弱(P<0.01)。②与模型对照组比较,针刺预防组和针刺治疗组诱导型一氧化氮合酶mRNA表达明显减弱(P<0.01),5-羟色胺1FmRNA表达显著增强(P<0.01)。结论:针刺调控5-羟色胺1F和诱导型一氧化氮合酶mRNA的表达可能是针刺防治偏头痛的分子机制。     

Retrorenal colon: implications for percutaneous diskectomy

It has been recommended that computed tomography (CT) with the patient prone be performed in every patient undergoing percutaneous diskectomy; this would enable detection of a retrorenal location of the colon, which could interfere with the percutaneous procedure. In this evaluation of 346 prone CT studies, only one patient (0.29%) was found to have retrorenal or retropsoas bowel that would have been perforated at diskectomy. Because of this extremely low prevalence, the performance of prone CT in every patient undergoing percutaneous lumbar diskectomy is not believed to be necessary.     

Does a single plasma phenylalanine predict quality of control in phenylketonuria?

A 1993 MRC working group on phenylketonuria suggested standardising blood phenylalanine measurements by taking blood samples at the same time each day. Since it is not known how representative of a 24 hour period a single phenylalanine concentration is, the aim of this study was to investigate the 24 hour variability of plasma phenylalanine in well controlled children with phenylketonuria. Sixteen subjects, 12 girls and four boys aged 1 to 18 years, had hourly venous blood samples collected for 13 hours between 09.00 and 21.00 on one day. Serial skin puncture blood specimens were then collected at 24.00, 03.00, and 06.00 within the same 24 hour period. All food and drink was weighed. The median variation in plasma phenylalanine concentration was 155 mumol/l/day, with a minimum of 80 and a maximum of 280. The highest concentration occurred in the morning between 6.00 and 9.00 in 63% of subjects; the lowest occurred between midday and midnight in 94%. Concentrations < 100 mumol/l occurred in 46% of children below 11 years, three having concentrations < 30 mumol/l for two, six, and seven hours respectively. Three of five subjects had concentrations above the MRC guidelines for 24% of the period studied. Except in two subjects, the blood concentrations did not rise in response to phenylalanine consumption. However, the greater the quantity of protein substitute taken between waking and the 16.00 specimen, the larger the decrease in daytime phenylalanine concentration (r = -0.7030) (p < 0.005). There is therefore wide variability in phenylalanine concentrations in a 24 hour period in children with phenylketonuria which is not reflected in a single observation. Further study is needed to investigate the effects of timing of protein substitute on the stability of phenylalanine concentrations.     

A Hodgkin cell-specific antigen is expressed on a subset of auto- and alloactivated T (helper) lymphoblasts

A Hodgkin cell-specific antigen detected by the monoclonal antibody Ki- 1 was found on T helper lymphocytes after activation by autologous and allogeneic stimulator cells. About 50% of lymphoblasts generated by auto- and alloactivation reacted with the antibody. In contrast, only less than 6% of lymphoblasts stimulated with Con-A, phytohemagglutinin (PHA), or protein A, and none of lymphoblasts activated by oxidative mitogenesis, expressed this antigen. Among several permanent cell lines tested, the K562, MOLT-4, HL-60, and EBV transformed B lymphoblastoid cells reacted with the Ki-1 antibody. The results may indicate possible relationships between the autoreactive subset of T lymphocytes and the pathogenesis of Hodgkin's disease.     

Malignant degeneration of Barrett''s esophagus: the role of the Ki-67 proliferation fraction, expression of E-cadherin and p53

Barrett's columnar epithelium with dysplasia is the most important risk factor for adenocarcinoma of the distal esophagus. The molecular mechanisms responsible for progression of columnar metaplasia to dysplasia and invasive carcinoma are mostly unknown. We investigated expression of the tumor suppressor gene p53, E-cadherin expression and cell proliferation in the metaplasia-dysplasia-carcinoma sequence of esophageal adenocarcinoma. In 24 patients with R0-resected adenocarcinomas of the distal esophagus we evaluated the expression of E-cadherin (antibody HECD-1), mutated p53 (antibody DO1) and cell proliferation (antibody MiB1) by immunohistochemistry in sections of adenocarcinoma, columnar metaplasia, with and without dysplasia, and in squamous epithelium of the esophagus. No p53 immunoreactivity was seen in sections of normal squamous epithelium or columnar metaplasia. Fifty per cent of invasive adenocarcinomas stained positive for mutated p53. The p53 expression correlated with the T-category (P = 0.048) and the N-category (P = 0.024). There was a significant decrease in the expression of E-cadherin from columnar metaplasia to dysplasia and to esophageal adenocarcinoma (P < 0.0001). Expression of E-cadherin in columnar metaplasia without dysplasia was similar to that seen in normal squamous epithelium of the esophagus. The Ki-67 proliferation fraction increased significantly from normal squamous epithelium to columnar metaplasia to dysplasia and to invasive carcinoma (P < 0.001), with a marked expansion of the proliferative component. There was no correlation between cell proliferation, E-cadherin expression and the tumor stage. In contrast to the alterations in the p53 expression, a decreased E-cadherin expression and the expansion of the proliferative component represent an early phenomenon in the malignant degeneration of Barrett's esophagus. This might aid in the early detection of esophageal adenocarcinoma.