Forces acting on particle-enhanced immunoassays

The aim of the present work is to study the role of the different forces involved in the agglutination of immune γ-globulin (IgG) covered latex particles due to antigen-antibody reaction. An experimental investigation on the adsorption of IgG molecules on three latexes with different surface charge densities is described. Photon correlation spectroscopy was used to determine the hydrodynamic layer thickness of the IgG molecules adsorbed on the latexes. In order to get an insight into the forces acting between two antibody-covered particles approaching each other, the colloidal stability and immunoreactivity of these biocomplexes were studied. They can be stabilized by electrostatic or hydration forces. The immunological agglutination of IgGimmobilized latex particles due to the addition of the antigen was quantified through scattered light intensity measurements. The immunoresponse increases with ionic strength of the medium until a maximum value is achieved. Above this maximum, the immunoreactivity decreases.     

A pandemic H1N1 influenza virus-like particle vaccine induces cross-protection in mice

Influenza virus-like particles (VLPs) represent promising alternative vaccines. However, it is necessary to demonstrate that influenza VLPs confer cross-protection against antigenically distinct viruses. In this study, a VLP vaccine comprising hemagglutinin (HA) and M1 from the A/California/04/2009 (H1N1) were used and its ability to induce cross-protective efficacy against heterologous viruses A/PR/8/34 (H1N1) and A/New Caledonia/20/99 (H1N1) in mice was assessed. Vaccination with 2009 H1 VLPs induced significantly higher levels of IgG cross-reactive with these heterologous viruses after the second boost compared to after the prime or first boost. Lung virus titers also decreased significantly and the lung cross-reactive IgG response after lethal virus challenge was significantly greater in immunized mice compared to naïve mice. Vaccinated mice showed 100% protection against A/PR/8/34 and A/Caledonia/20/99 viruses with only moderate body weight loss and induction of cross-reactive recall, IgG antibody-secreting cell responses. The variations in HA amino acid sequences and antigenic sites were determined and correlated with induction of cross-protective immunity. These results indicate that VLPs can be used as an effective vaccine that confers cross-protection against antigenically distinct viruses.     

Retroviral Sequences in Rheumatoid Arthritis Synovium

There are several relationships between retroviruses and cellular transformation, as well as retroviruses being involved in the development of autoimmune diseases. Retroviruses have been discussed as etiologic agents modulating or triggering certain pathways in the pathogenesis of rheumatoid arthritis (RA). However, none of the currently known retroviruses has been identified as specific for RA. Due to the unique properties of retroviruses, distinct experimental approaches can be used to detect retroviral activity in cells and tissues. Current research in RA using state-of-the-art molecular biology techniques includes both the search for exogenous and endogenous retroviral gene sequences in synovium of patients with RA.     

硅纳米颗粒诱导小鼠间充质干细胞成骨分化和迁移的体外研究*

目的 通过溶胶-凝胶法合成纳米尺径的硅基生物活性颗粒（SBPs）,检测其对间充质干细胞（MSCs）成骨分化和迁移的作用。方法 通过溶胶-凝胶法合成SBPs,通过扫描电镜和ZATA电位分析仪检测颗粒的物理特征。在培养基中添加SBPs配置成系列浓度的条件培养基,检测不同浓度的SBPs对小鼠MSCs增殖、成骨分化和迁移的影响。结果 SBPs的平均直径为134.3 nm,并且呈均匀分散球形颗粒。不同浓度的SBPs对MSCs增殖无影响;但4 µg/mL的SBPs对细胞成骨分化有明显的促进作用;高浓度（>16 µg/mL）的SBPs抑制MSCs的成骨分化;4 µg/mL的SBPs对MSCs有明显的促进迁移的作用。结论 在适宜浓度范围内（1 ～ 4 μg/mL）,SBPs具有促成骨作用和诱导MSCs迁移,未来可能被用来与其他生物材料复合制备新型的骨移植材料。     

Polystyrene Brushes on Fully Deuterated Organic Nanoparticles by Surface‐Initiated Nitroxide‐Mediated Radical Polymerization

The synthesis of polystyrene (PS) brushes on fully deuterated PS nanoparticles by surface‐initiated nitroxide‐mediated radical polymerization (SI‐NMRP) is reported. Due to the high demand of deuterated monomers, an efficient deuteration procedure of suitable and readily available precursors is developed. SI‐NMRP of styrene is improved regarding reaction control, grafting density, and conversion. Insights into the scaling behavior and conformational features of surface‐attached PS chains on deuterated particles are investigated by using dynamic light scattering measurements, proving that polymer brushes are formed. The particles with surface‐attached initiator are shown to be uniform spherical core‐shell particles by small‐angle neutron scattering measurements.

     

Uterine artery embolisation for uterine fibroids: Our experience at a tertiary care service hospital

Background

Uterine artery embolisation (UAE) has evolved as a minimally invasive and effective alternative, treatment modality for women with symptomatic fibroids. We discuss our initial experience of UAE in the management of symptomatic fibroids.

Methods

Twenty five symptomatic patients of uterine fibroids were treated with UAE by selectively cannulating and injecting poly vinyl alcohol particles into the uterine arteries. Post treatment follow up was done at 2 and 6 months respectively.

Results

Pre-treatment, the sizes of fibroids were between 3.9 and 10.9 cm (mean 7.4) on ultrasonography. Of the total 25 patients, 49 uterine arteries were embolised with a technical success rate of 98%. Menorrhagia persisted in 7 patients, dysmenorrhea in 4 patients and pressure symptoms in 2 patients respectively in follow up study of six months which corresponds to a reduction in symptoms by 68% for menorrhagia, 71% for dysmenorhoea and 75% for those with pressure symptoms respectively. At 2 months follow-up post embolisation, the mean diameter of the fibroid was 4.03 cm (range 2–5.2 cm) and at 6 months 3.2 cm (range 1.3–4.1 cm), corresponding to size reduction of 45.5% and 57%, respectively. Follow up with ultrasonography at 2 and 6 months period showed successful fibroid reduction in 24 patients with corresponding reduction in the symptomatology. One patient remained symptomatic with increase in fibroid size and had to undergo hysterectomy.

Conclusion

Uterine artery embolisation can be considered as an alternative to hysterectomy in appropriately selected symptomatic patients of uterine fibroids.     

桑杏颗粒治疗小儿风热挟痰证型咳嗽的疗效研究

目的：比较中药复方桑杏颗粒与急支糖浆治疗小儿咳嗽（风热挟痰证）的疗效,探讨复方桑杏颗粒治疗小儿咳嗽的临床应用前景。方法选择某市医院就诊的符合条件的患儿60例,随机分为两组,治疗组（30例）口服桑杏颗粒剂,对照组（30例）口服急支糖浆口服液,两组均以7天为一疗程,观察比较两组的疗效。结果治疗组咳嗽、咯痰症状、肺部听诊体征及胸片改善上均优于对照组。桑杏颗粒治疗小儿咳嗽的效果优于对照组,与急支糖浆相比,其需要治疗人数（NNT）为5人。结论桑杏颗粒剂治疗小儿急性支气管炎疗效显著,临床上值得推广应用。     

不同戊型肝炎病毒IgG抗体检测试剂盒临床对比分析

目的比较磁微粒化学发光试剂与酶联免疫吸咐测定试剂检测戊型肝炎病毒Ig G抗体的结果差异。方法选取企业样本库2010年1月至2012年5月住院和门诊患者935例,分别用A厂家酶联免疫吸咐测定试剂和郑州安图生物磁微粒化学发光试剂测定戊型肝炎病毒Ig G抗体平行检测,不符样本用C厂家酶联免疫吸咐测定试剂复测。结果郑州安图生物磁微粒化学发光试剂和戊型肝炎病毒Ig G抗体A厂家酶联免疫吸咐测定试剂阳性一致百分比为95.5%,阴性一致百分比为97.7%,总符合率为97.2%,差异无统计学意义(P>0.05)。结论磁微粒化学发光戊型肝炎病毒Ig G抗体试剂与酶联免疫吸咐测定试剂临床性能相似,适于临床推广应用。     

Searching for the initiating site of the major capsid protein to generate virus-like particles for a novel laboratory mouse papillomavirus

Correctly folded virus-like particles (VLPs) of papillomavirus (PV) display conformationally dependent epitopes that are type specific, maintained on authentic virions, and induce neutralizing antibodies. Alignment of the L1 amino acid (aa) sequences of 84 PVs revealed that the lengths of their N-termini are diverse and that multiple, possible initiation methionine (met) codons exist. The L1 gene of MusPV (MmuPV1), that naturally infects immunodeficient laboratory mouse strain (NMRI-Foxn1^nu/Foxn1^nu), has four met codons at the 1st, 2nd, 28th, and 30th aas from its N-terminus. Of these, the 3rd and 4th mets, that are at the 28th and 30th aa position from the N-termius, respectively, are located at the position where most PVs have their first met. These two mets, located at the 9th and 11th from the YLPP conserved aas of most PVs, should be considered as consensus initiation codons of PV L1s. Three L1 proteins of MusPV, starting from the 2nd, 3rd, and 4th mets, were expressed using a baculovirus expression system and characterized for their ability to self-assemble into VLPs. While MusPV L1 proteins starting from the 2nd met expressed an L1 protein that did not fold into VLPs, the L1s starting from the 3rd and 4th mets generated correct VLPs in abundant quantities. We now conclude that the highest quantity and best quality VLPs are made from the consensus L1 met of MusPV.     

Alphavirus-Based Vaccines

Alphavirus vectors have demonstrated high levels of transient heterologous gene expression both in vitro and in vivo and, therefore, possess attractive features for vaccine development. The most commonly used delivery vectors are based on three single-stranded encapsulated alphaviruses, namely Semliki Forest virus, Sindbis virus and Venezuelan equine encephalitis virus. Alphavirus vectors have been applied as replication-deficient recombinant viral particles and, more recently, as replication-proficient particles. Moreover, in vitro transcribed RNA, as well as layered DNA vectors have been applied for immunization. A large number of highly immunogenic viral structural proteins expressed from alphavirus vectors have elicited strong neutralizing antibody responses in multispecies animal models. Furthermore, immunization studies have demonstrated robust protection against challenges with lethal doses of virus in rodents and primates. Similarly, vaccination with alphavirus vectors expressing tumor antigens resulted in prophylactic protection against challenges with tumor-inducing cancerous cells. As certain alphaviruses, such as Chikungunya virus, have been associated with epidemics in animals and humans, attention has also been paid to the development of vaccines against alphaviruses themselves. Recent progress in alphavirus vector development and vaccine technology has allowed conducting clinical trials in humans.