带荧光素酶基因的乙型脑炎病毒SA14-14-2感染性克隆的构建及鉴定

目的：构建带有荧光素酶基因的乙型脑炎（简称乙脑）病毒感染性克隆,并通过体外拯救获得恢复病毒,用于乙脑病毒致病机理研究、病毒感染在小鼠体内的动态分布以及乙脑疫苗免疫效果评价的高通量方法建立。方法：应用反向遗传学、融合PCR以及无缝拼接等体外重组技术,将荧光素酶报告基因（F-LUC）插入到乙脑病毒SA14-14-2全长感染性克隆的5''非编码区与C蛋白编码区之间,线性化后体外转录为RNA并转染BHK21细胞,在细胞感染和动物试验分别检测恢复病毒的拯救和F-LUC的表达情况。结果：成功构建了带有F-LUC报告基因的SA14-14-2乙脑病毒全长感染性克隆,并拯救获得了重组病毒。基因序列分析及细胞与动物水平均证明拯救的病毒可较高水平表达荧光素酶基因。结论：本研究构建出带有荧光素酶报告基因F-LUC的SA14-14-2感染性克隆,并拯救获得带有荧光素酶的重组乙脑病毒,为乙脑血清中和抗体的高通量筛选、病毒感染在小鼠体内的动态分布和致病机理研究奠定了基础。     

Fluoroscopically guided transesophageal echocardiogram in a patient with esophageal stents

A 73-year-old man with history of coronary artery disease and bypass surgery, atrial fibrillation, and left lower lobe non-small cell lung cancer was admitted with recurrent pneumonia and was referred for transesophageal echocardiogram for suspected aortic valve endocarditis by transthoracic echocardiography. The patient had a history of radiation treatment for lung cancer 6 years ago. He had subsequently developed esophageal strictures requiring repeated dilatations, and eventually repeated esophageal stenting. Recurrent aspiration pneumonia led to the discovery of stent erosion into his trachea leading to tracheoesophageal fistula. A covered Y tracheal stent was placed to close the fistulous tract, but persistent aspiration was noted. The cross-sectional diameter of the esophageal stents was determined to be larger than the transesophageal echocardiography (TEE) probe. TEE was performed under fluoroscopy for added safety. The esophageal stent position was confirmed with fluoroscopy before and after the procedure and the TEE probe remained inside the distal stent in the midesophageal position during the entire procedure. Small mobile vegetation was seen on the right coronary cusp and the noncoronary cusp showed a smaller vegetation. The patient tolerated the procedure well and there were no complications. Infectious disease consultation was obtained and antibiotic regimen was modified accordingly. Although there are studies addressing the safety of TEE in patients with esophageal varices, to our knowledge, there is no report of TEE being performed in patients with esophageal or tracheoesophageal stents. This case illustrates that TEE may be performed in patients with esophageal stents under careful fluoroscopic guidance. (Echocardiography 2012;29:E5-E7).     

Laser Therapy as an Effective Method for Implant Surface Decontamination: A Histomorphometric Study in Rats

Background: To the best of the authors’ knowledge, a standard protocol for treating peri‐implantitis is not yet established. Methods: A total of 150 titanium disks with smooth or rough surfaces contaminated with microbial biofilm were implanted subcutaneously in rats after undergoing one of three treatments: 1) low‐intensity laser (LIL); 2) antimicrobial photodynamic therapy (aPDT); or 3) toluidine blue O (TBO). Sterile and contaminated disks served as negative (NC) and positive (C) control groups, respectively. After days 7, 28, and 84, tissue inflammation was evaluated microscopically by measuring the density of collagen fibers (degree of fibrosis) and concentration of polymorphonuclear neutrophils. Results: Surface texture did not affect the degree of inflammation, but the area of reactive tissue was significantly greater for rough implants (2.6 ± 3.7 × 10⁶ µm²) than for smooth ones (1.9 ± 2.6 × 10⁶ µm²; P = 0.0377). Group C presented the lowest and group NC presented the highest degree of fibrosis with significance only after day 7; these groups had the highest and lowest scores, respectively, for degree of inflammation. Group C showed the largest area of reactive tissue (9.11 ± 2.10 × 10⁶ µm²), but it was not significantly larger than group LIL (P = 0.3031) and group TBO (P = 0.1333). Group aPDT showed the smallest area (4.34 ± 1.49 × 10⁶ µm²) of reactive tissue among the treatment groups. After day 28, groups LIL, aPDT, TBO, and C resembled group NC in all the studied parameters. Conclusion: Group aPDT showed more favorable results in parameter area of reactive tissue than the other methods after day 7, but over longer time periods all methods produced outcomes equivalent to sterile implants.     

孟加拉玫瑰红-绿光角膜胶原交联术的研究进展

角膜胶原交联术（CXL）是利用光照射被光敏剂浸润的角膜,诱导角膜中胶原纤维之间以及胶原和其他基质蛋白之间形成共价键（即交联）,从而增加角膜硬度并维持角膜生物力学稳定性的一种光化学方法。传统的核黄素-紫外光诱导的角膜胶原交联术（UVX）是以核黄素作为光敏剂,370 nm的紫外光进行照射,虽然能在一定程度上维持角膜生物力学稳定性,但不良反应和局限性也不可忽视。玫瑰红-绿光角膜胶原交联术（RGX）是一种新的CXL技术,以孟加拉玫瑰红作为光敏剂,然后用532 nm的绿光进行照射,可用于治疗圆锥角膜、感染性角膜炎和促进角膜伤口愈合。现将从RGX的原理和过程、安全性与有效性、与UVX的比较及其在眼部的应用研究等进行综述。     

Mannan-binding lectin is a determinant of survival in infective endocarditis

Mannan-binding lectin (MBL) is a collectin plasma protein activating the lectin pathway of the complement system, enhancing opsonophagocytosis and modulating the cytokine response to inflammation. Deficiency of MBL, caused by structural mutations or promoter polymorphisms in the MBL2 gene, has been associated with increased susceptibility to infection and autoimmune disease. Thus, as infective endocarditis remains a severe disease requiring intensive and long-term treatment with antibiotics, we examined whether there was an association between MBL and clinical outcome in 39 well-characterized patients with infective endocarditis. Five patients (13%) had MBL concentrations < 100 microg/l and were considered MBL-deficient. This proportion was similar to that in a healthy control group of blood donors. Mortality 3 months after diagnosis was 20% in patients with MBL-deficiency and 9% in patients with normal MBL. The 5-year mortality was 80% and 25%, respectively. MBL-deficiency was on univariate survival statistics associated with significantly higher mortality on follow-up (P=0 x 03). In conclusion, this is the first report of an association between MBL-deficiency and survival in infective endocarditis. The present observation is important, as replacement therapy in MBL-deficient patients is possible. For certain high-risk subgroups, it opens new perspectives for improvement of treatment and outcome in infective endocarditis.     

V4 region of the HIV-1 envelope gene mediates immune escape and may not promote the development of broadly neutralizing antibodies

To date, inducing the production of broadly neutralizing antibodies (bnAbs) against HIV-1 in humans has been unsuccessful. Several studies have explored the coevolution of HIV-1 and neutralizing antibodies (nAbs), but little is known about what affects the lack of bnAbs after long-term infection. A better understanding of the coevolution of the virus and nAbs in cases involving no bnAb production will help in the design of an effective HIV-1 vaccine. An individual with acute CRF01_AE HIV-1 infection who lacked bnAbs at just over 2 years post-infection (p.i.) was identified from a cohort of HIV negative men who have sex with men. The coevolution of the viral envelope gene and nAbs was studied over 741 days p.i. Strain-specific antibodies (ss-Abs) to the transmitted/founder (T/F) virus developed within 54 days p.i., but plasma collected at subsequent time points could not neutralize synchronous viruses until 557 days p.i., when the plasma acquired low-level synchronous but not heterologous neutralizing activity. The V4 region of envelope gene mutated firstly and continually evolve up to 2 years p.i. Multiple variations in the V4 region, including substitutions, deletions and glycosylation mutations, were driven by ss-Abs and mediated immune escape partially by impacting the binding of nAbs to the virus. The remarkable variations in the V4 region mediated immune escape from ss-Abs and contributed to the affinity maturation of ss-Abs against the T/F virus but may not promote the development of bnAbs. Thus, the V4 region might not be a good target for an HIV-1 vaccine.