羊布鲁杆菌M5-90 BP26抗原单克隆抗体的制备及鉴定

目的 制备高亲和性的羊布鲁杆菌M5-90 BP26抗原单克隆抗体,并对抗体进行鉴定.方法 将质粒pET-28a-BP26转化感受态大肠埃希菌(E.coli)BL21 (DE3),构建原核表达质粒pET-28a-BP26,用镍离子金属螯合亲和层析法(Ni-NTA)纯化、重组BP26蛋白(rBP26).将纯化后的rBP26蛋白与弗氏完全佐剂等体积混合成乳化抗原,接每只100 μg/0.1 ml在BALB/c小鼠皮下多点注射进行初次免疫;2周后,按每只50μg/0.1ml 在小鼠皮下多点注射进行再次免疫.再次免疫后2周,小鼠尾静脉取血测效价,检测免疫效果;在细胞融合前3天,将乳化抗原按每只小鼠50μg腹腔注射加强免疫.将小鼠骨髓瘤SP2/0细胞与脾细胞按1∶5比例在聚乙二醇( PEG) 1450作用下进行细胞融合,置于37℃、5％CO2培养箱中培养;10 d后取细胞培养上清液,用间接酶联免疫吸附法(ELISA)测定,筛选分泌抗rBP26抗体的杂交瘤细胞;再经过反复3次克隆,筛选出单克隆全阳性的杂交瘤细胞建株,用杂交瘤细胞株制备BP26抗原单克隆抗体,并以初始杂交瘤细胞克隆导命名.利用羊布鲁杆菌M5 -90疫苗株制备膜蛋白提取物(NMP),采用免疫印迹法(Western)及斑点间接酶联免疫吸附法(Dot-ELISA)对筛选的单克隆抗体进行免疫学特性鉴定,用单克隆抗体亚型试剂盒进行抗体分型和Kappa (κ)和Lambda(λ)轻链鉴定.结果 成功地获得2株能稳定分泌抗rBP26抗原的高亲和性杂交瘤3C3和5A5单克隆抗体,并能与羊布鲁杆菌M5-90疫苗株上的NMP结合,构建成M5-90 BP26抗原单克隆抗体,抗体亚型分别为IgG1和IgG2b,轻链均为κ链.结论 鉴定结果表明,成功制备2株羊布鲁杆菌BP26抗原的高亲和性单克隆抗体,抗体具有识别M5-90疫苗株的膜蛋白构象表位的能力,优势表位的识别可为羊布鲁杆菌M5-90疫苗株的改造提供实验依据.     

Risk of adrenal crisis in dental patients: Results of a systematic search of the literature

BackgroundThe authors performed a systematic search of the literature to identify the frequency of, risk of experiencing and factors associated with adrenal crises in dental patients.MethodsThe authors searched PubMed and Ovid MEDLINE (1947-June 20, 2012) and Embase (1974-2012) for English-language articles related to cases of adrenal crisis in dentistry and extracted and analyzed data from the articles. The six authors determined whether the cases identified met a consensus definition of adrenal crisis.ResultsOf 148 articles identified in the initial screening, 34 articles were included in the final review, from which six cases met the criteria of adrenal crisis. The authors categorized four cases as “suggestive of adrenal crisis” and two cases as “consistent with adrenal crisis.” Risk factors were significant adrenal insufficiency, pain, infection, having undergone an invasive procedure, having received a barbiturate general anesthetic, and poor health status and stability at the time of presentation. The authors estimated risk to be less than one in 650,000 in patients with adrenal insufficiency.ConclusionsAdrenal crisis is rare in dental patients, with only six reports of it having been published in the past 66 years. Risk is associated with unrecognized adrenal insufficiency, poor health status and stability at the time of treatment, pain, infection, having undergone an invasive procedure and having received a barbiturate general anesthetic.Clinical ImplicationsRisk of adrenal crisis is reduced through proper evaluation of the patient, identification of risk factors and following appropriate preventive measures.     

iRoot BP修复磨牙髓室底穿孔的研究

目的 探讨iRoot BP直接修复髓室底穿孔的效果。方法 收集新鲜拔除的人恒磨牙40颗,其中36颗于髓室底中央制备直径2 mm的穿孔洞型,随机分为A、B组,每组18颗,分别用iRoot BP和矿物三氧化聚合体（MTA）修复髓室底穿孔;另外4颗为对照组,只开髓不制备髓室底穿孔。从A、B组中各随机选择3个样本用扫描电子显微镜观察材料和牙本质的结合界面;其余15个样本用葡萄糖氧化酶-蒽酮法检测微渗漏值。结果 A组中,iRoot BP与牙本质结合较为紧密,而B组中MTA和牙本质之间存在不均匀的微小间隙。在观察期内,B组的微渗漏值高于A组,其差异有统计学意义（P<0.05）。结论 iRoot BP修复髓室底穿孔的封闭效果优于MTA。     

Thyroid effects of endocrine disrupting chemicals

In recent years, many studies of thyroid-disrupting effects of environmental chemicals have been published. Of special concern is the exposure of pregnant women and infants, as thyroid disruption of the developing organism may have deleterious effects on neurological outcome. Chemicals may exert thyroid effects through a variety of mechanisms of action, and some animal experiments and in vitro studies have focused on elucidating the mode of action of specific chemical compounds. Long-term human studies on effects of environmental chemicals on thyroid related outcomes such as growth and development are still lacking. The human exposure scenario with life long exposure to a vast mixture of chemicals in low doses and the large physiological variation in thyroid hormone levels between individuals render human studies very difficult. However, there is now reasonably firm evidence that PCBs have thyroid-disrupting effects, and there is emerging evidence that also phthalates, bisphenol A, brominated flame retardants and perfluorinated chemicals may have thyroid disrupting properties.     

Negative association between plasma aldosterone concentration/plasma renin activity and morning blood pressure surge in never-treated hypertensive patients

Morning blood pressure (BP) surge (MS) has been known to be a predictor of cardiovascular events. Currently, few studies have evaluated the underlying mechanism underlying MS, which may include neurohormonal factors and the renin–angiotensin–aldosterone system (RAAS). This study aimed to examine plasma aldosterone concentration (PAC) and plasma renin activity (PRA) and BP parameters with or without MS in never-treated subjects with essential hypertension. This cross-sectional study included a total of 261 patients (mean age: 48.8 years; 60.5% male) with never-treated essential hypertension who were registered in a working group at The Catholic University of Korea. The patients were divided into the MS group, which was defined as having the highest quartile of morning BP increase from sleep (>31?mmHg; n?=?66) and the non-MS group (≤31?mmHg; n?=?195). We collected 24-h ambulatory BP, pulse wave velocity, ankle brachial index, PAC and PRA from all patients. The measured PAC and PRA were lower in the MS group than in the non-MS group (PAC: 9.0?±?5.4?ng/dl versus 12.2?±?8.7?ng/dl, p?p?=?0.002). The MS group had greater variations in daytime, nighttime and 24-h systolic blood pressure (SBPs) than the non-MS group (24-h SBP: 15.6?±?4.4?mm Hg for the non-MS group and 18.9?±?4.9?mmHg for the MS group; p?BP variability. Therefore, further studies on sympathetic nervous system activation in hypertensives with extreme MS are needed. MS in enrolled patients who were at relatively low risk in this study may be less affected by the RAAS.     

乙型肝炎病毒前S1蛋白反式激活蛋白2结合蛋白1基因的克隆及其反式调节基因的筛选

目的 克隆HBV前S1蛋白反式激活蛋白2结合蛋白1(PS1TP2BP1)基因,并筛选与其相互作用的反式激活基因.方法 应用聚合酶链反应(PCR)扩增PS1TP2BP1基因,鉴定正确后再将其亚克隆到真核表达载体pcDNATM3.1/myc-His A上;以真核表达质粒pcDNATM3.1/mycHis A-PS1TP2BP1转染HepG2细胞,构建cDNA消减文库;进行测序及同源性分析.结果 从HepG2细胞来源的cDNA中扩增出PS1TP2BP1基因,并成功进行TA克隆,酶切、测序均正确后,成功构建真核表达重组体.消减文库扩增后得到35个阳性克隆,经菌落PCR分析,得到15个含200～1000 bp插入片段的菌落.对所得片段测序,并进行间源性分析,显示15种已知基因编码蛋白可能是PS1TP2BP1反式激活靶基因.结论 成功克隆PS1TP2BP1,并构建了PS1TP2BP1反式激活基因差异表达的cDNA消减文库,为今后进一步分析、研究病毒蛋白的致病机制奠定了基础.     

an intelligent otologic drill

Objective To test a modified otologic drill under different drilling conditions for its ability toidentify drilling faults and stop drilling.MethodsBased on force analysis and previous works,an otologic drill was modified and equipped with three sensors.Under various conditions,the drill was used to simulate three drilling faults and normal drilling,and signals from the drill were analyzed to extract the characteristic signal.A multi-sensor information fusion system and a stop program were designed to recognize drilling faults and stop drilling.Results Signals from each sensor changed consistently in response to drilling condition changes,with high repeatability and regularity.The average identification rate was 72.625%,68.575%,70.5% and 81.3% respectively for the three simulated drilling faults and normal drilling.The stop program stopped drilling in 0.2-0.3 seconds when a drilling faults was detected.Conclusions This study shows that the forces acting on the drill bit change predictably in the three simulated drilling conditions;that using suitable BP neural networks,the drilling faults can be reliably identified,and that a stop program based upon characteristic signal recognition can stop drilling quickly upon detecting drilling faults.This lays a foundation for development of a system capable of predicting drilling faults and automatic drill control.Further studies are being undertaken for practical application of such a system.