卵清白蛋白特异性T细胞克隆的建立及T细胞受体使用情况分析

目的：体外建立可长期培养的抗原特异性T细胞系及克隆，并分析其T细胞受体的使用情况。方法：用卵清白蛋白（OVA）免疫BALB／c小鼠，取淋巴结细胞在体外用抗原原复刺激建立抗原特异性T细胞系，通过能限稀释法进行克隆，应用锚定PCR方法分析其特异的T细胞受体的应用。结果：建立了H－2^d限制的OVA特异性T细胞系，获得了3株特异性较高的T细胞克隆，T细胞系中TCR AV11S4和BV4S1应用频率最高，3株T细胞克隆的TCR均为AV5S2和BV2S1，这些T细胞所使用的TCRα链和β链在CDR3区有明显的共性，结论：获得了卵清白蛋白特异的T细胞系和克隆，且其T细胞受体的应用有一定的限制性。     

急性心肌梗死后的延迟冠状动脉内支架植入治疗

目的　评估急性心肌梗死后梗死相关冠状动脉内支架植入的临床疗效。方法　 15 4例急性心肌梗死患者 ,平均年龄 (6 1± 12 )岁于发病后平均 13天行冠状动脉内支架术 ,所有患者常规服用肠溶阿司匹林和噻氯匹定。观察住院期和随访期的临床事件。结果　 15 4例患者共植入 173个支架 (平均 1 1个 /例 )。支架植入的指征 :选择性初发病变 (denovo)占 2 4 3 % ,急性或濒危闭塞占13 9% ,有发生闭塞高危因素的病变占 6 1 8%。所用支架主要为Nir支架 (2 6 % )、Multi Link支架(19% )、XT支架 (13% )、Crossflex支架 (10 % ) ,等等。支架植入时最大球囊充盈压力为 (12± 2 )大气压。平均残余狭窄 (7± 8) %。住院期间无一例死亡、心肌梗死和需重复再通治疗 ,但术后“微坏死(micronecrosis)”率为 1 3%。术后 6个月病死率为 3 9% ,Q波型或非Q波型心肌梗死率为 1 9% ,支架内再狭窄而行再次冠状动脉腔内成形术率 6 1%。总的无心脏事件存活率为 89 6 %。结论　心肌梗死后行冠状动脉内支架术是安全的 ,并能改善患者的近期预后 ,但其远期疗效尚需进一步研究。     

欧洲移民抗菌耐药性的系统性综述和元分析

正全球范围内抗菌耐药性发生率正逐步上升。人们担心,欧洲移民人数的增加会加剧抗菌耐药性的形势。但是,目前尚无全面性的研究来评估移民对欧洲抗菌耐药性发生率带来的影响。2018年7月的《The Lancet. Infectious diseases》刊载了一项研究,研究者们开展了一项系统性的综述和元分析,识别并汇总了欧洲移民中抗菌耐药性的携带和感染数据,以探索不同移民群体间以及不同环境中抗菌耐药性的模式差异。为开展该系统性综述和元分析,研究者们搜索了MEDLINE、Embase、PubMed和Scopus数据库,不设语言限制,设定时间为2000年1月1日至     

A 3-year longitudinal analysis of changes in fitness, physical activity, fatness and screen time

Aim:  To analyse whether changes in physical activity index (PAI), screen time (ST: television, computer) and body mass index (BMI) made a contribution to longitudinal changes in fitness of children and adolescents. Additionally, we analysed the interaction between baseline fitness level and changes in fitness.
Methods:  This is a 3-year longitudinal study of 345 high school students aged 11–19 years. Students performed curl-ups, push-ups and 20-m shuttle run tests from Fitnessgram. PA and ST were evaluated using a standard questionnaire. Standardized scores of fitness tests were summed. Changes over time were calculated as Δ₁ (2007 minus 2006), Δ₂ (2008 minus 2007) and Δ₃ (2008 minus 2006).
Results:  Changes in PAI were positively and independently associated with changes in fitness in Δ₁, Δ₂ and Δ₃. Changes in BMI were negatively associated with changes in fitness in Δ₃. Participants highly fit at baseline were those who showed positive changes in PAI over Δ₃, decreased changes in ST and had the lowest increase in BMI over 3 years compared with those low-fit at baseline.
Conclusions:  Changes in BMI were associated with changes in fitness over 3 years. However, changes in PAI were the best predictor for changes in fitness in each year and over the 3 years of evaluation in youth.     

Hyperplastic polyps and the risk of adenoma recurrence in the polyp prevention trial

BACKGROUND AND AIMS: Recent studies have suggested that some hyperplastic polyps may be associated with an increased risk of colorectal cancer. Prospective information on the risk of adenoma recurrence associated with hyperplastic polyps is limited. We sought to investigate whether the coexistence of hyperplastic polyps with adenomas increases the risk of adenoma recurrence. METHODS: We used unconditional logistic regression models to examine the association between baseline hyperplastic polyps and subsequent adenoma recurrence during a 3-year follow-up evaluation, among 1637 participants in the Polyp Prevention Trial. RESULTS: A total of 437 participants (26.7%) had hyperplastic polyps coexisting with adenomas at baseline. Of these, 132 (30.2%) had at least one hyperplastic polyp in the proximal colon, whereas 305 (69.8%) had only distal hyperplastic polyps. When compared with subjects without any hyperplastic polyps at baseline, there was no statistically significant association between the presence of baseline hyperplastic polyps and recurrence of any adenoma (odds ratio [OR], 1.19; 95% confidence interval [CI], 0.94-1.51) or advanced adenoma (OR, 1.25; 95% CI, 0.78-2.03). Also, there was no association between hyperplastic polyp location and adenoma recurrence (OR, 1.01; 95% CI, 0.69-1.48) for any proximal hyperplastic polyp (OR, 1.26; 95% CI, 0.96-1.65) and for distal hyperplastic polyps. CONCLUSIONS: The coexistence of hyperplastic polyps with adenomas, irrespective of location, does not confer an increased risk of adenoma recurrence beyond that of adenomas alone within 3 years of follow-up evaluation. Prospective long-term studies on adenoma recurrence risk associated with hyperplastic polyps in screening populations are needed.     

哌拉西林钠／舒巴坦钠（2：1）体内抗菌活性研究

目的：评价哌拉西林钠／舒巴坦钠（2：1）的体内抗菌活性。方法：用产酶的金黄色葡萄球菌，大肠埃希菌、肺炎克雷伯菌及铜绿假单胞菌建立感染动物模型，用哌拉西林钠／舒巴坦钠（2：1）及单用派拉西林钠，舒巴坦钠及对照药阿莫西林钠／舒巴坦钠（2：1）通过静脉注射，皮下注射进行感染动物的治疗，评价对感染小鼠的保护作用。结果：舒巴坦钠对感染小鼠的抗菌保护作用极弱，ED50均＞400mg/kg，哌拉西林钠静脉注射单用对四种菌感染动物的ED50分别为55．7mg/kg,6.54mg/kg,24.09mg/kg与11．07mg/kg，哌拉西林钠／舒巴坦钠（2：1）者为27．96mg/kg，2.49mg/kg,6.75mg/kg与6.36mg/kg，分别比哌拉西林钠强2，2．5，3．6与1．8倍，哌拉西林钠皮下注射单用对四种菌感染动物的ED50分别为哌拉西林钠，哌拉西林钠／舒巴坦钠（2：1）皮下注射对四种产酶菌感染小鼠的保护作用弱于静脉注射者，ED50分别为51．95mg/kg,4.41mg/kg,8.19mg/kg,10.58mg/kg，但仍比哌拉西林钠强1．2，2，3．6与1．5倍。结论：无论静脉注射或皮下注射，哌拉西林钠／舒巴坦钠（2：1）对上述四种产酶菌株感染小鼠的体内抗菌活性（DE50）均明显优于哌拉西林钠，舒巴坦钠单用，也强于阿莫西林／舒巴坦钠（2：1）。静脉注射是临床应用较恰当的给药途径。     

Evaluation of surveillance case definition in the diagnosis of leptospirosis, using the Microscopic Agglutination Test: a validation study

Background  

Leptospirosis is endemic in both urban and rural areas of Sri Lanka and there had been many out breaks in the recent past. This study was aimed at validating the leptospirosis surveillance case definition, using the Microscopic Agglutination Test (MAT).     

Regional differences in the vasorelaxant effects of nicorandil and amlodipine on isolated porcine coronary arteries

Summary— The vasorelaxant effects of nicorandil, a K⁺-channel opener, and amlodipine, a dihydropyridine-type Ca²⁺-channel blocker, were investigated on partially and maximally K⁺-depolarized ring preparations from the porcine left anterior descending coronary artery. By comparing vascular responses in the proximal and distal parts of the epicardial segment, the scope of the study was to evaluate regional differences in the action of nicorandil and amlodipine. Nicorandil (10 ⁷- 10^-4 M) shifted the K⁺ concentration-response curves to the right and depressed the maximal contractile responses in a concentration-dependent manner, consistent with K⁺-channel opening and secondary non-K⁺-channel opening mechanisms of action. Nicorandil had a significantly more potent relaxant effect in the proximal compared to the distal arterial rings contracted with 85 mM K⁺. Pretreatment with methylene blue (10^-5 M) did not significantly influence the regional difference in the action of nicorandil. Amlodipine (10⁹- 10^-6 M) had a significantly more potent and effective inhibitory and relaxant effect than nicorandil under the same conditions. In contrast to nicorandil, the effect of amlodipine was more prominent in the distal compared to the proximal vessel rings. The cumulative addition of extracellular Ca²⁺ exhibited a more potent contractile response in the distal rather than in the proximal rings. Nicorandil totally and amlodipine partly eliminated the contractile responses to the lowest concentration of Ca²⁺. The inhibitory effect of amlodipine on the contractile responses to higher Ca²⁺ concentrations was more pronounced than that of nicorandil. The results show that there are regional differences in the responsiveness of porcine coronary arteries to Ca²⁺, nicorandil and amlodipine. Our findings indicate that the regional difference in nicorandil-induced vasodilation was caused neither by the K⁺-channel opening nor by the nitrate-like mechanism of action, but could be due to a direct Ca²⁺-influx blocking effect of the drug.     

Analysis of the expression of neutrophil-specific antigen NB1: characterization of neutrophils that react with but are not agglutinated by anti-NB1

The neutrophil-specific NB antigen system has been serologically characterized with human alloantisera. Two alleles, NB1 and NB2, have been described. NB1 is expressed on a subpopulation of peripheral blood neutrophils in 97 percent of healthy donors. Human alloantibodies have been used to identify the 58- to 64-kDa glycoprotein (GP) on which NB1 is located. NB1 can usually be detected by both a granulocyte immunofluorescence (GIF) assay and a granulocyte agglutination (GA) assay, but neutrophils from some donors have been found to react with anti-NB1 in GIF but not in GA assays. To determine if the latter neutrophils express NB1 and the corresponding 58- to 64-kDa GP, these neutrophils were probed with rabbit and human sera specific for NB1. First, the proportion of neutrophils that express NB1 was quantitated. Neutrophils from donors that typed as NB1-positive in both GA and GIF assays were analyzed by flow cytometry with antisera to NB1. Human and rabbit anti-NB1 reacted with 71 +/− 17 percent and 70 +/− 17 percent of neutrophils, respectively. There was no difference in the expression of NB1 in NB1-homozygous and NB1-heterozygous individuals. In contrast, significantly fewer neutrophils from four donors that typed as NB1- positive in GIF assay but not GA assay reacted with human (27 +/− 12%; p < 0.001) and rabbit (26 +/− 12%; p < 0.001) anti-NB1. When neutrophils from these same four donors were probed with rabbit and human anti-NB1 by immunoblotting and immunoprecipitation, the 58- to 64- kDa GP was identified.(ABSTRACT TRUNCATED AT 250 WORDS)     

Complement sensitivity of paroxysmal nocturnal hemoglobinuria bone marrow cells

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired disorder in which erythrocytes, granulocytes, and platelets are defective, as shown by increased susceptibility of RBCs, WBCs, and platelets to complement- mediated lysis in vitro. The purpose of this study is to determine the sensitivity to complement lysis of PNH and non-PNH erythroid and myeloid precursors using the release of 59Fe and myeloperoxidase as specific markers to monitor the lytic action of complement on erythroid and myeloid cell precursors, respectively. Erythroid cell precursors in four of four PNH patients demonstrated increased sensitivity to complement-mediated lysis. Myeloid cell precursors in four of five PNH patients also exhibited increased sensitivity to complement and antibody. In addition, CFU-c growth was below normal in the marrow of seven PNH patients. These findings support the hypothesis that the defect in PNH occurs at the level of the hematopoietic stem cell.