仙台病毒 Tianjin 株缺陷干扰颗粒体内外诱导大鼠脑胶质瘤细胞凋亡的研究

目的探讨仙台病毒Tianjin株缺损干扰颗粒（ defective interfering particles ,DI颗粒）体内外诱导大鼠脑胶质瘤细胞C6凋亡的作用。方法将不同滴度仙台病毒Tianjin株DI颗粒分别与大鼠脑胶质瘤细胞C6作用不同时间,以培养基作为阴性对照、完整病毒作为阳性对照,通过DNA片段琼脂糖凝胶电泳、TUNEL染色、AnnexinⅤ-FITC/PI标记流式细胞仪分析等检测细胞凋亡情况。建立大鼠皮下胶质瘤模型,通过测量肿瘤大小观察DI颗粒抑瘤作用,病理切片HE染色观察肿瘤组织病理变化,TUNEL法检测肿瘤组织细胞凋亡情况。结果 C6细胞在体外经DI颗粒诱导后, DNA片段琼脂糖凝胶电泳呈阶梯状;流式细胞仪及TUNEL检测显示,DI颗粒组与完整病毒组细胞凋亡率明显增高,且呈时间-剂量依赖型。动物实验结果显示,DI颗粒和完整病毒均可明显抑制肿瘤生长;肿瘤组织病理切片HE染色显示DI颗粒组和完整病毒组瘤结节内瘤细胞较少;TUNEL原位细胞凋亡检测显示DI颗粒组和完整病毒组凋亡细胞明显增加,以上结果与阴性对照组比较差异均有统计学意义（P＜0．01）。结论仙台病毒Tianjin株DI颗粒在体内外均能引起大鼠脑胶质瘤C6细胞凋亡,且呈时间-剂量依赖型,提示DI颗粒有辅助治疗脑胶质瘤的可能性。     

Intestinal mucosa permeability following oral insulin delivery using core shell corona nanolipoparticles

Chitosan nanoparticles (NC) have excellent capacity for protein entrapment, favorable epithelial permeability, and are regarded as promising nanocarriers for oral protein delivery. Herein, we designed and evaluated a class of core shell corona nanolipoparticles (CSC) to further improve the absorption through enhanced intestinal mucus penetration. CSC contains chitosan nanoparticles as a core component and pluronic F127-lipid vesicles as a shell with hydrophilic chain and polyethylene oxide PEO as a corona. These particles were developed by hydration of a dry pluronic F127-lipid film with NC suspensions followed by extrusion. Insulin nested inside CSC was well protected from enzymatic degradation. Compared with NC, CSC exhibited significantly higher efficiency of mucosal penetration and, consequently, higher cellular internalization of insulin in mucus secreting E12 cells. The cellular level of insulin after CSC treatment was 36-fold higher compared to treatment with free insulin, and 10-fold higher compared to NC. CSC significantly facilitated the permeation of insulin across the ileum epithelia, as demonstrated in an ex vivo study and an in vivo absorption study. CSC pharmacological studies in diabetic rats showed that the hypoglycemic effects of orally administrated CSC were 2.5-fold higher compared to NC. In conclusion, CSC is a promising oral protein delivery system to enhance the stability, intestinal mucosal permeability, and oral absorption of insulin.     

Consequences of exposure to peri-articular injections of micro- and nano-particulate cobalt–chromium alloy

Metal hip replacements generate both metal particles and ions. The biological effects of peri-articular exposure to nanometre and micron sized cobalt chrome (CoCr) wear particles were investigated in a mouse model. Mice received injections of two clinically relevant doses of nanoparticles (32 nm), one of micron sized (2.9 μm) CoCr particles or vehicle alone into the right knee joint at 0, 6, 12 and 18 weeks. Mice were analysed for genotoxic and immunological effects 1, 4 and 40 weeks post exposure. Nanoparticles but not micron particles progressively corroded at the injection site. Micron sized particles were physically removed. No increase of Co or Cr was seen in peripheral blood between 1 and 40 weeks post exposure to particles. No significant inflammatory changes were observed in the knee tissues including ALVAL or necrosis. DNA damage was increased in bone marrow at one and forty weeks and in cells isolated from frontal cortex at 40 weeks after injection with nanoparticles. Mice exposed to the micron sized, but not nanoparticles became immunologically sensitized to Cr(III), Cr (VI) and Ni(II) over the 40 week period as determined by lymphocyte transformation and ELISpot (IFN-γ and IL-2) assays. The data indicated that the response to the micron sized particles was Th1 driven, indicative of type IV hypersensitivity. This study adds to understanding of the potential adverse biological reactions to metal wear products.     

Substance P enhanced titanium particles-induced RANKL expression in fibroblasts from periprosthetic membrane

Abstract

Aseptic loosening remains the primary cause of failure in total joint arthroplasty. Implant-derived particles are thought to be a main cause of osteolysis that leads to the failure. Substance P (SP) immunoreactive nerve fibers have been detected in the periprosthetic membrane of aseptic loose hip prostheses. We isolated fibroblasts from periprosthetic membrane. Fibroblasts were examined by real-time RT-PCR and enzyme-linked immunosorbent assay for expression of the receptor activator of nuclear factor kappa B ligand (RANKL), osteoprotegerin (OPG), cyclooxygenase (COX)-1, and COX-2. Experiments were performed in the presence and absence of titanium particles, SP and NS-398 (a selective COX-2 inhibitor). Titanium particles or SP stimulated RANKL and COX-2 expression in fibroblasts, whereas NS-398 inhibited RANKL production, suggesting a COX-2-mediated event. Moreover, SP enhanced COX-2 and RANKL expression by titanium particles-stimulated fibroblasts. Thus, SP and titanium particles acted synergistically to increase RANKL expression.     

Effects of concentrated ambient ultrafine particulate matter on hallmarks of Alzheimer’s disease in the 3xTgAD mouse model

BackgroundExposure to air pollution has been identified as a possible environmental contributor to Alzheimer’s Disease (AD) risk. As the number of people with AD worldwide continues to rise, it becomes vital to understand the nature of this potential gene-environment interaction. This study assessed the effects of short-term exposures to concentrated ambient ultrafine particulates (UFP, <100 nm) on measurements of amyloid-β, tau, and microglial morphology.MethodsTwo cohorts of aged (12.5–14 months) 3xTgAD and NTg mice were exposed to concentrated ambient UFP or filtered air for 2 weeks (4-h/day, 4 days/week). Bronchoalveolar lavage fluid and brain tissue were collected twenty-four hours following the last exposure to evaluate lung inflammation, tau pathology, amyloid-β pathology, and glial cell morphology.ResultsNo exposure- or genotype-related changes were found with any of the measures of lung inflammation or in the hippocampal staining density of astrocyte marker glial fibrillary acidic protein. The microglia marker, ionized calcium binding adaptor molecule 1, and amyloid-β marker, 6E10, exhibited significant genotype by exposure interactions such that levels were lower in the UFP-exposed as compared to filtered air-exposed 3xTgAD mice. When microglia morphology was assessed by Sholl analysis, microglia from both NTg mouse groups were ramified. The 3xTgAD air-exposed mice had the most ameboid microglia, while the 3xTgAD UFP-exposed mice had microglia that were comparatively more ramified. The 3xTgAD air-exposed mice had more plaques per region of interest as measured by Congo red staining as well as more plaque-associated microglia than the 3xTgAD UFP-exposed mice. The number of non-plaque-associated microglia was not affected by genotype or exposure. Levels of soluble and insoluble human amyloid-β₄₂ protein were measured in both 3xTgAD groups and no exposure effect was found. In contrast, UFP-exposure led to significant elevations in phosphorylated tau in 3xTgAD mice as compared to those that were exposed to air, as measured by pT205 staining.ConclusionsExposure to environmentally relevant levels of ultrafine particulates led to changes in tau phosphorylation and microglial morphology in the absence of overt lung inflammation. Such changes highlight the need to develop greater mechanistic understanding of the link between air pollution exposure and Alzheimer’s disease.     

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.     

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.