桦褐孔菌多糖的提取工艺优化

目的研究桦褐孔菌多糖提取工艺优化。方法以多糖含量为指标,在单因素研究基础上,采用4因素3水平的响应面分析法对桦褐孔菌多糖的提取工艺进行优化研究,并检测重金属砷的含量。结果桦褐孔菌多糖提取的优化工艺条件为：乙醇浓度30％、提取温度95℃、提取时间2．5h、液料比30：1。在该条件下,粗多糖得率为33．6％,样品中多糖含量为6．177％。桦褐孔菌多糖实际提取含量为5．993％,重金属含量降低。结论优化工艺提取率高,快速,重金属含量低,可用于桦褐孔菌的多糖提取。     

星点设计–效应面法优化川芎提取工艺

目的 采用星点设计效应面法优化川芎中阿魏酸和藁本内酯的提取工艺。方法 以川芎药材中阿魏酸、藁本内酯的质量分数为考察指标,考察乙醇体积分数、提取温度以及提取时间对提取工艺的影响,对结果进行二项式拟合,用效应面法选择较佳工艺条件,并进行预测分析。结果 确定较优提取工艺为83 ℃下,14倍量73%乙醇提取2次,每次2 h,含量实际值与预测值偏差为?1.37%。结论 星点设计效应面法优化川芎提取工艺,方法简便,结果可靠,预测性良好。     

采用响应面法优化替考拉宁的层析工艺

目的对替考拉宁的层析提取工艺进行优化。方法通过对层析用树脂的筛选和单因素试验,分别考察了上样pH值、洗脱液pH、洗脱液乙醇浓度等对替考拉宁提取比的影响,确定各因素的适宜水平。在此基础上,使用Box—Behnken法通过Design—Expert软件设计响应面试验,寻找最优条件。结果替考拉宁的最佳提取工艺条件为：上样pH6．45、洗脱液pH8．00、洗脱液乙醇浓度59％。在此条件下,替考拉宁的提取比为0．9487。结论经优化,替考拉宁分离纯化的提取比提高了10．23％,产品色素符合《中国药典》的要求。     

表面等离子体共振生物传感器研究进展

本文介绍了一种新型的生物传感器——表面等离子体激元共振(SPR)传感器,它是进行生物分子相互作用分析的一种先进手段。与其他技术相比,它具有实时检测、无需标记、耗样量较少等优点,在药物筛选、Il缶床诊断、细胞膜模拟和生物大分子相互反应等领域中的新兴应用日益扩大。本文介绍了 SPR 的结构、原理、优点、应用及其新进展。随着联用技术和纳米技术的深入研究,SPR 将有广泛的应用前景。     

乙肝病毒外膜大蛋白检测在阿德福韦抗病毒治疗中的应用

目的 通过检测抗病毒治疗患者血清中乙肝病毒外膜大蛋白(HBV-LP)和病毒载量(HBV-DNA),探讨阿德福韦抗病毒治疗过程中HBV-LP与HBV-DNA的关系,观察HBV-LP用于评估抗病毒治疗效果的应用价值.方法 采用酶联免疫吸附试验(ELISA)方法对HBV-LP进行检测;采用荧光定量PCR方法对HBV-DNA进行检测.结果 抗病毒治疗有效组患者HBV-DNA和HBV-LP下降趋势一致;抗病毒治疗无效组患者HBV-DNA始终没有出现阴转,HBV-LP的含量维持在较高水平;抗病毒治疗效果反复组患者HBV-LP的含量维持较高水平或变化不明显,HBV-DNA则出现暂时阴转.结论 动态监测HBV-LP的含量可用于阿德福韦抗病毒治疗效果的评估.     

Characterization of the structural modifications accompanying the loss of HBsAg particle immunogenicity

The aim of this work was to further understand the relationship between the immunogenicity and the structure of Hepatitis B surface antigen (HBsAg) particles used in Hepatitis B vaccines. To reach this aim, we compared by using a large range of techniques, the structure and properties of untreated particles with those of particles stored for 3 weeks at +60 °C, a treatment which resulted in a loss of HBsAg antigenicity (toward RF-1 mAb) and immunogenicity (in mice). While untreated particles imaged by electron microscopy and atomic force microscopy appeared as isolated nanoparticles of ∼ 20 nm, heated particles appeared as long chains of particle aggregates with a partial loss of their protein protrusions. Moreover, infrared spectroscopy and circular dichroism revealed that the secondary structure of the S proteins was significantly affected, with a loss of 10% of their α-helix content. Steady-state and time-resolved fluorescence data further revealed strong modifications of the most emitting Trp residues at the particle surface, confirming significant changes in the conformation of the S proteins. Moreover, modifications in the organization of both the lipid core and lipid membrane surface of the heated particles were evidenced by environment-sensitive 3-hydroxyflavone probes. Taken together, our data evidenced a clear relationship between the bona fide S protein structure and lipid organization notably at the particle surface and the particle immunogenicity.     

The link between genetic variation and variability in vaccine responses: Systematic review and meta-analyses

Although immune response to vaccines can be influenced by several parameters, human genetic variations are thought to strongly influence the variability in vaccine responsiveness. Systematic reviews and meta-analyses are needed to clarify the genetic contribution to this variability, which may affect the efficacy of existing vaccines. We performed a systematic literature search to identify all studies describing the associations of allelic variants or single nucleotide polymorphisms in immune response genes with vaccine responses until July 2013. The studies fulfilling inclusion criteria were meta-analyzed.     

Prevalence of chronic hepatitis B virus infection before and after implementation of a hepatitis B vaccination program among children in Nepal

Background

In Nepal, an estimated 2–4% of the population has chronic hepatitis B virus (HBV) infection. To combat this problem, from 2002 to 2004, a national three dose hepatitis B vaccination program was implemented to decrease infection rates among children. The program does not currently include a birth dose to prevent perinatal HBV transmission. In 2012, to assess the impact of the program, we conducted a serosurvey among children born before and after vaccine introduction.

Methods

In 2012, a cross-sectional nationally representative stratified cluster survey was conducted to estimate hepatitis B surface antigen (HBsAg) prevalence among children born from 2006 to 2007 (post-vaccine cohort) and among children born from 2000 to 2002 (pre-vaccine cohort). Demographic data, as well as written and oral vaccination history were collected. All children were tested for HBsAg; mothers of HBsAg positive children were also tested. Furthermore, we evaluated the field sensitivity and specificity of the SD Bioline HBsAg rapid diagnostic test by comparing results with an enzyme immunoassay.

Results

Among 2181 post-vaccination cohort children with vaccination data by either card or recall, 86% (95% confidence interval [CI] 77–95%) received ≥3 hepatitis B vaccine doses. Of 1200 children born in the pre-vaccination cohort, 0.28% (95% CI 0.09–0.85%) were positive for HBsAg; of 2187 children born in the post-vaccination cohort, 0.13% (95% CI 0.04–0.39%) were positive for HBsAg (p = 0.39). Of the six children who tested positive for HBsAg, two had mothers who were positive for HBsAg. Finally, we found the SD Bioline HBsAg rapid diagnostic test to have a sensitivity of 100% and a specificity of 100%.

Conclusions

This is the first nationally representative hepatitis B serosurvey conducted in Nepal. Overall, a low burden of chronic HBV infection was found in children born in both the pre and post-vaccination cohorts. Current vaccination strategies should be continued.     

层流GICU物体表面消毒方法的比较及菌群检测

目的比较两种消毒剂对层流综合重症监护病房（GICU）高频接触物体表面的抑菌效果,为层流GICU选择合理的物体表面消毒方法提供临床依据;了解物体表面细菌的污染情况,为预防控制感染提供理论依据。方法对层流GICU住院患者床档、床头桌的物体表面（常规消毒前）,采集样本做细菌培养、鉴定,以了解层流GICU物体表面菌群分布。分别采用含有效氯500 mg/L消毒剂（常规组）、伽玛TM消毒湿巾（对照组）对层流GICU床单位周围物体表面进行消毒,比较两种消毒方法在消毒后的抑菌率和物体表面细菌总数合格率。结果常规消毒前共采集200份物体表面样本,分离细菌87株,细菌污染率43.50%。检出革兰阳性菌68株（78.16%）,以棒状杆菌（18株,26.47%）、金黄色葡萄球菌（16株,23.53%）、表皮葡萄球菌（16株,23.53%）为主;革兰阴性杆菌19株（21.84%）,以鲍曼不动杆菌为主（12株,63.16%）。进行物体表面消毒后10 min的抑菌率,常规组为（94.89±7.72）%,对照组为（96.33±12.88）%,两组差异无统计学意义（P>0.05）;两组物体表面细菌总数合格率均为100%。结论定期对层流GICU住院患者床单位周围物体表面进行检测、消毒,并规范医护人员的操作及手卫生执行力,是切断细菌传播,预防医院感染简单、有效的方法。     

Skin-specific knockdown of hyaluronan in mice by an optimized topical 4-methylumbelliferone formulation

Hyaluronan (HA) is abundant in the skin; while HA can be synthesized by the synthases (HAS1-3), HAS2 is the leading contributor. Dysregulation and accumulation of HA is implicated in the pathogenesis of diseases such as keloid scarring, lymphedema and metastatic melanoma. To understand how HA synthesis contributes to skin physiology, and pathologic and fibrotic disorders, we propose the development of skin-specific HA inhibition model, which tests an optimal delivery system of topical 4-methylumbelliferone (4-MU).A design-of-experiments (DOE) approach was employed to develop an optimal 4-MU skin-delivery formulation comprising propylene glycol, ethanol, and water, topically applied to dorsal skin in male and female C57BL/6J wildtype mice to determine the effect on HAS gene expression and HA inhibition. Serum and skin samples were analyzed for HA content along with analysis of expression of HAS1-3, hyaluronidases (HYAL 1-2), and KIAA1199.Using results from DOE and response surface methodology with genetic algorithm optimization, we developed an optimal topical 4-MU formulation to result in ∼70% reduction of HA in dorsal skin, with validation demonstrating ∼50% reduction in HA in dorsal skin. 4-MU topical application resulted in significant decrease in skin HAS2 expression in female mice only. Histology showed thicker dermis in male mice, whereas female mice had thinner dermal layer with more adiposity; and staining for HA-binding protein showed that topical 4-MU resulted in breakdown in HA.Our data suggest a topical 4-MU formulation-based dermal HA inhibition model that would enable elucidating the skin-specific effects of HA in normal and pathologic states.