Precise coulometric determination of redox inert anions based on electrolysis at the aqueous|organic solution interface

The flow cell proposed previously for the rapid and coulometric determination of cations based on the electrochemical ion transfer at the aqueous|organic solution interface was improved to be applicable to the determination of anions. The developed cell was composed of a porous poly(tetrafluoroethylene) tube (1.0 mm in inner diameter), a copper wire (0.8 mm in diameter) inserted into the tube, a platinum wire placed outside the tube, an organic solution into which the tube was immersed and a reference electrode in the organic solution. The aqueous solution containing a species of interest was flowed through the narrow gap between the tube and the copper wire. A potential difference was applied at the aqueous|organic solution interface by using the copper wire and the reference electrode in the organic solution in order to realize the ion transfer at the interface, and the current due to the interfacial ion transfer was detected by the copper and platinum wires. The developed cell was evaluated adopting the transfer of an anion such as perchlorate, picrate or alkylsulphonates from the aqueous solution to 1,2-dichloroethane (used as the organic solution), and demonstrated that the anions of 10⁻⁴ mol dm⁻³ level could be determined with coefficients of variations better than 0.2% (n = 5). The applicability of the developed cell to the flow injection analysis of anions was also discussed.     

Influences on length of stay in an enhanced recovery programme after colonic surgery

Aim Enhanced recovery after surgery (ERAS) programmes have been shown to accelerate and enhance functional recovery after colonic surgery. We analysed prospectively collected data to investigate potentially modifiable factors that may influence the length of stay (LOS) in the ERAS setting at a single institution. Method Between October 2005 and November 2008, prospective data were collected on consecutive patients who underwent elective colonic surgery without a stoma. Patients with rectal cancer, those unable to participate in preoperative ERAS components because of their inability to communicate effectively in English, those with cognitive impairment and those with an American Society of Anesthesiologists (ASA) grade of ≥4 were excluded. Statistical analyses were performed using the Mann–Whitney U‐test and Cox regression modelling. Results A total of 100 (79 malignancies) patients underwent elective colon resection during the study period. There were 57 right‐sided, 41 left‐sided and two total colectomies. The median age of the patients was 67.5 (range 31–92) years and the median day stay was 4 (range 3–46) days. Factors with significant correlations for reduced LOS were female gender, the surgeon, operative severity, high‐dependency unit (HDU) admission and incision type favouring laparoscopic and transverse approaches. Age, operation site, indication for surgery and body mass index were not significant predictors of hospital stay. Gender, operative severity, HDU admission and surgeon did not have any independent correlation with LOS; in contrast to the ASA score and the type of incision, which did. Conclusion Lower ASA score, transverse incision laparotomy and laparoscopy correlated independently with reduced postoperative LOS within the ERAS setting.     

弓形虫感染大鼠外周血T淋巴细胞亚群及IFN-γ、TNF-α、IL-4动态变化

目的 观察弓形虫感染大鼠外周血T淋巴细胞亚群及干扰素-γ（IFN-γ）、肿瘤坏死因子-α（TNF-α）、白细胞介素-4（IL-4）动态变化。 方法 将54只清洁级Sprague-Dawley（SD）成年大鼠随机分成9组,其中8组每鼠腹腔注射经纤维素-11（CF-11）纯化的活弓形虫速殖子悬液2 ml（2×10⁵/L）。分别于弓形虫感染后1、3、7、14、28、35、42、60 d时取大鼠外周全血,流式细胞术检测T细胞亚群变化,ELISA检测外周血IFN-γ、TNF-α、IL-4动态变化。对照组腹腔注射2 ml生理盐水。 结果 T淋巴细胞亚群CD8+水平在感染弓形虫后3 d（14.22%）、7 d（14.93%）、14 d（16.08%）均显著低于正常水平（23.08%）（P＜0.05）,至感染后28 d恢复正常水平,而CD4+水平在整个感染过程中无明显变化。IFN-γ和IL-4水平在感染后第7 d分别升高至6.73 pg/ml和6.91 pg/ml（P＜0.05）,至感染60 d仍高于正常水平;TNF-α至感染后28 d（14.37 pg/ml）及60 d均高于正常水平（10.81 pg/ml）（P＜0.05）。 结论 弓形虫感染后大鼠外周血CD8+水平一度降低,28 d后恢复正常,CD4+无明显变化,IFN-γ、IL-4和TNF-α均高于正常水平,但出现时间有差异。     

Antibody to E1 peptide of hepatitis C virus genotype 4 inhibits virus binding and entry to HepG2 cells in vitro

AIM: To analyze the neutralizing activity of antibodies against E1 region of hepatitis C virus (HCV). Specific polyclonal antibody was raised via immunization of New Zealand rabbits with a synthetic peptide that had been derived from the E1 region of HCV and was shown to be highly conserved among HCV published genotypes. METHODS: Hyper-immune HCV E1 antibodies were incubated over night at 4 degree Celsius with serum samples positive for HCV RNA, with viral loads ranging from 615 to 3.2 million IU/ mL. Treated sera were incubated with HepG2 cells for 90 min. Blocking of viral binding and entry into cells by anti E1 antibody were tested by means of RT-PCR and flow cytometry. RESULTS: Direct immunostaining using FITC conjugated E1 antibody followed by Flow cytometric analysis showed reduced mean fluorescence intensity in samples pre-incubated with E1 antibody compared with untreated samples. Furthermore, 13 out of 18 positive sera (72%) showed complete inhibition of infectivity as detected by RT-PCR. CONCLUSION: In house produced E1 antibody, blocks binding and entry of HCV virion infection to target cells suggesting the involvement of this epitope in virus binding and entry. Isolation of these antibodies that block virus attachment to human cells are useful as therapeutic reagents.     

以流式细胞术建立中国汉族健康儿童外周血淋巴细胞亚群相对计数的正常参考值

目的建立中国汉族健康儿童外周血淋巴细胞亚群的正常参考值范围。方法选取首都医科大学附属北京儿童医院入托、入学体检,或术前查体及术后复查(均为对免疫功能影响不大的疾病)的0～18岁汉族儿童为研究对象。按年龄分为婴儿组(28d至12个月),幼儿组(～3岁),学龄前组(～7岁),学龄组(～12岁)和青春期组(～18岁)。采集外周血以双色及四色荧光标记流式细胞术检测淋巴细胞亚群T细胞(CD3+CD19-)、CD4+T细胞(CD3+CD4+)、CD8+T细胞(CD3+CD8+)、B细胞(CD3-CD19+)和NK细胞(CD3-CD16+CD56+)相对计数及CD4+/CD8+比值。比较各年龄组不同性别淋巴细胞亚群分布的差异,建立正常参考值范围。结果由于青春期组所收集的标本数较少,将该研究对象组予以删除。最终纳入28d至12岁儿童592例。①婴儿组T细胞、CD8+T细胞百分比与CD4+/CD8+比值性别差异均有统计学意义,幼儿组CD4+T细胞、CD8+T细胞百分比与CD4+/CD8+比值性别差异均有统计学意义,学龄组CD4+T细胞百分比性别差异有统计学意义;②除了男童T细胞百分比各年龄组间差异无统计学意义外,男女儿童各年龄组间外周各血淋巴细胞亚群分布总体上差异均有统计学意义;进一步行男女儿童淋巴细胞亚群不同年龄组间两两比较,发现多个年龄组间差异有统计学意义;③男女儿童T细胞、CD8+T细胞和NK细胞百分比随年龄增长均呈逐渐升高趋势;CD4+T细胞、B细胞百分比及CD4+/CD8+比值随年龄增长均呈逐渐降低趋势;男女儿童T细胞、B细胞、NK细胞百分比和CD4+/CD8+比值升高或降低的程度略有不同;④中国汉族健康儿童淋巴细胞亚群分布特点与欧、美、非洲国家儿童相比存在相似的升高或降低的趋势,但数值上存在一定的差异。结论儿童淋巴细胞亚群分布存在年龄和性别的差异。本研究成功建立中国汉族28d至12岁健康儿童淋巴细胞亚群相对计数正常参考值范围。     

Effect of TNF-α on Raji cells at different cellular levels estimated by various methods

Tumor necrosis factor (TNF)-α, a pleiotropic cytokine, has been shown to induce diverse and opposite effects on lymphoid malignancy depending on TNF receptor system expression. Based on this, we investigated its in vitro dose- and time-related effect on the malignant B-cell line Raji, derived from Burkitt lymphoma patients, at different intracellular levels. The membrane alteration was estimated by lactate dehydrogenase (LDH) release and by flow cytometry; intracellular metabolic energy by determination of the total intracellular LDH activity; total cytosole protein mass by sulforhodamine B assay; and cell growth by incorporation of [³H]thymidine into DNA. Significant increase of LDH through cell membrane alteration was accompanied by decrease of intracellular metabolized energy and total protein mass. TNF-α at lower concentrations (125 and 250 pg/ml) significantly induced cell proliferation in comparison with 1,000 pg/ml of TNF-α, which induced more cell death. TNF-α induced maximal apoptosis rate up to 30% after 24 h, showing more effects for a necrotic form of cell death. Here we reported opposite and diverse effects of TNF-α at different intracellular levels in Raji cells, when applied in different assays, showing characteristics for every cellular compartment.     

EB病毒相关性噬血细胞综合征的临床特征及外周血淋巴细胞亚群的变化

目的 分析EB病毒相关性噬血细胞综合征(EBV-AHS)患儿的临床特点,了解其外周血淋巴细胞亚群的变化.方法 20例EBV-AHS患儿,均符合噬血细胞综合征的诊断标准,并有EBV感染的证据,对其临床特点进行总结分析,并采用流式细胞术检测外周血淋巴细胞亚群CD4+、CD8+、CD19+、CD16+CD56+、CD4+/CD8+的水平.选择20例健康儿童作为对照组.结果 在EBV-AHS的诊断标准中,以发热、血常规2系以上降低、乳酸脱氢酶升高(＞1 000 U/L)、高密度脂蛋白降低及铁蛋白增高(＞1 500 g/L)5项指标异常发生率最高,均为100%.与对照组相比,EBV-AHS患儿外周血CD8+T及CD19+B细胞比例增高(分别为53.70% ±10.6% vs 27.05% ±8.22%,24.95% ±5.34% vs11.85% ±4.53%),而CD4+T及CD16+CD56+NK细胞比例下降(分别为23.60% ±6.42% vs 45.20% ±5.74%,5.55% ±2.87% vs 14.70% ±4.16%),CD4+/CD8+比值降低(0.46±0.16 vs 1.84±0.68),差异均有显著性(P＜0.01).结论 EBV-AHS患儿细胞及体液免疫功能发生紊乱,导致了疾病的发生发展.     

血管生物反应器流场的数值分析

目的 研究一种新型小口径血管生物反应器在不同工况下的流场分布。方法 采用数值方法模拟反应器外筒单独旋转、内筒单独旋转和内外筒同向等速旋转情况下其内部的流场分布,对流速和切应力等参数进行比较分析。结果 血管生物反应器工作时,培养液随内外筒的旋转而旋转流动,速度分布均匀;可为培养液内的细胞提供非破坏性的低切应力环境;并且反应器内部的切应力大小与转速呈二次函数关系。结论 该反应器能为血管培养提供良好的培养环境,本研究可为其实验研究提供指导意见和理论基础。     

血小板膜糖蛋白Ⅱb/Ⅲa受体拮抗剂ETBT对血小板功能的影响

目的:观察血小板膜糖蛋白Ⅱb/Ⅲa(GPⅡb/Ⅲa)拮抗剂——依替巴肽(Eptifibatide,ETBT)对血小板聚集、释放、收缩血块和促凝活性等的影响。方法:在正常人全血或富血小板血浆(PRP)中加入不同浓度ETBT,分别检测二磷酸腺苷(ADP)诱导的血小板最大聚集率(rPAmax)、血小板CD62p表达百分率、血块收缩率和血小板3因子(PF3)有效性,通过与对照组比较获得ETBT对血小板功能的抑制率。结果:各种浓度(0.5～5.0μM)ETBT均对rPAmax有显著抑制作用(P0.01),且随ETBT浓度增加而增加;较高浓度(5.0～10μM)ETBT对血块收缩有显著抑制作用(P0.01);ETBT(0～80μM)ETBT对血小板CD62p表达(P=0.425)和PF3有效性没有明显抑制作用。结论:ETBT显著抗血小板聚集作用,但对血小板CD62p表达和促凝作用的影响较小;ETBT抗血小板聚集及抑制血块收缩的作用与其浓度呈正相关。     

快速无创性产前诊断唐氏综合征的初步研究

目的建立快速无创性产前诊断唐氏综合征的有效诊断模式。方法从98名孕妇中筛选出12名高度怀疑唐氏妊娠者,当日流式细胞术分选母血中的胎儿有核红细胞（Fetal nucleated red blood cells,FNRBCs）,制备滴片后,次日进行多重引物原位杂交（muti—primed in situ labeling,multi—PRINS）检测胎儿细胞21号、Y染色体。结果均可在两日内得到诊断结论,诊断10例正常胎儿和两例男性唐氏综合征胎儿,与实际胎儿核型完全一致。结论流式分选母血中胎儿有核红细胞后多重PRINS技术检测细胞染色体可作为快速无创性产前诊断的有效模式,并可为其他非整倍体异常和单基因病的快速无创性产前诊断提供有效参考。