Laccase/caffeic acid-catalyzed crosslinking coupled with galactomannan alters the conformational structure of ovalbumin and alleviates Th2-mediated allergic asthma

Ovalbumin(OVA)is the major allergenic protein that can induce T helper 2(Th2)-allergic reactions,for which current treatment options are inadequate.In this study,we developed a polymerized hypoallergenic OVA product via laccase/caffeic acid(Lac/CA)-catalyzed crosslinking in conjunction with galactomannan(Man).The formation of high molecular weight crosslinked polymers and the Ig G-binding were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE)and Western blotting.The study indicated that Lac/CA-catalyzed crosslinking plus Man conjugation substantially altered secondary and tertiary structures of OVA along with the variation in surface hydrophobicity.Gastrointestinal digestion stability assay indicated that crosslinked OVA exhibited less resistance in simulated gastric fluid(SGF)and simulated intestinal fluid(SIF).Mouse model study indicated that Lac-Man/OVA ameliorated eosinophilic airway inflammatory response and efficiently downregulated the expression of Th2-related cytokines(interleukin(IL)-4,IL-5,and IL-13),and upregulated IFN-γand IL-10 expression.Stimulation of bone marrow-derived dendritic cells with Lac-Man/OVA suppressed the expression of phenotypic maturation markers(CD80 and CD86)and MHC class II molecules,and suppressed the expression levels of proinflammatory cytokines.The knowledge obtained in the present study offers an effective way to acquire a hypoallergenic OVA product that can have a therapeutic effect in alleviating OVA-induced allergic asthma.

Rosmarinic acid improves tracheal smooth muscle responsiveness and lung pathological changes in ovalbumin-sensitized rats

Objective:To evaluate the effect of rosmarinic acid on tracheal smooth muscle responsiveness and lung pathological changes in ovalbumin-sensitized rats.Methods:Rats were randomly divided into six groups:the control group,the asthmatic group,and the asthmatic groups treated with dexamethasone(1 mg/kg;oral gavage)or three doses of rosmarinic acid(0.5,1,and 2 mg/kg;oral gavage).For induction of asthma,rats received intraperitoneal injections and inhalation of ovalbumin.After 21 days,bronchoalveolar lavage fluid and lung samples were collected for histopathological analyses.Moreover,total and differential white blood cell counts were determined.Results:The rosmarinic acid-treated group had significantly lower tracheal smooth muscle responses to methacholine than the asthmatic group.In addition,rosmarinic acid reduced white blood cell count and the percentages of eosinophils,monocytes,and neutrophils while increasing the percentage of lymphocytes.Ovalbumin-induced lung pathological changes were significantly improved by treatment with rosmarinic acid.Conclusions:Rosmarinic acid improves tracheal smooth muscle responsiveness and lung pathological changes in ovalbumin-sensitized rats.

Myricetin alleviates ovalbumin-induced allergic rhinitis in mice by regulating Th1/Th2 balance

Objective:To evaluate the effect of myricetin on ovalbumin(OVA)-induced allergic rhinitis in mice.Methods:Mice were sensitized and challenged using OVA(5%,500 mL)intraperitoneally and intranasally,respectively,on an alternative day for 14 days,followed by administration of myricetin(50,100,and 200 mg/kg)till day 21.Nasal symptoms,biochemical parameters,protein expressions,and histopathology were observed.Results:OVA-induced increased nasal symptoms including rubbing,sneezing,and discharge were significantly reduced by myricetin(100and 200 mg/kg)(P<0.05).Myricetin also protected against histamine challenge and attenuated elevated serum immunoglobulin E(IgE;total and OVA-specific),total IgG1,andβ-hexosaminidase levels,as well as leukotriene C4 and interleukins levels in nasal lavage fluid(P<0.05).Western blot analysis showed that myricetin significantly upregulated the protein expression of T-box expressed in T cells,while downregulating the protein expression of GATA binding protein 3,NF-κB,and IκB-α(P<0.05).Additionally,OVA-induced histopathological abberations in the nasal mucosa was markedly ameliorated by myricetin treatment(P<0.05).Conclusions:Myricetin exerts anti-allergic effects against OVAinduced allergic rhinitis via regulating Th1/Th2 balance.

自组装纳米颗粒肿瘤疫苗OVA257-264-mi3的构建及其保护效果评价

目的构建SpyCatcher-mi3纳米颗粒疫苗递送载体,评价其在增强卵清蛋白CD8+T细胞表位肽OVA 257-264免疫原性和在小鼠荷瘤模型中免疫保护效果。方法SpyCatcher-mi3蛋白由大肠杆菌表达,依次经亲和层析、阴离子交换层析纯化得到;合成OVA 257-264-SpyTag多肽,通过SpyTag/SpyCatcher蛋白质连接系统构建纳米颗粒OVA 257-264-mi3;通过细胞溶血实验和细胞毒性实验评价OVA 257-264-mi3体外安全性,记录小鼠体重变化和镜检脏器组织切片HE染色评价OVA 257-264-mi3体内安全性;将6~8周龄,18~20 g,SPF级,雌性C57BL/6小鼠按随机数字表法分为OVA 257-264-mi3组、OVA 257-264组和Control组,每组14只,分别于第0、14、28天免疫小鼠,末次免疫后第14天通过ELISpot检测其脾脏淋巴细胞中IFN-γ分泌细胞数量评价其免疫原性;在小鼠荷瘤模型上通过核磁共振成像等手段评价纳米颗粒疫苗OVA 257-264-mi3的保护效果。结果SpyCatcher-mi3和OVA 257-264-mi3均自组装形成均一稳定的纳米颗粒,平均粒径约为43.8 nm和91.3 nm;OVA 257-264-mi3在体内外均具有良好的安全性;OVA 257-264-mi3组小鼠每1×106个脾脏淋巴细胞中IFN-γ分泌细胞数量达253,显著高于OVA 257-264组(P<0.05);OVA 257-264-mi3组小鼠第22天荷瘤体积约151.1 mm 3,显著小于OVA 257-264组(P<0.05),且观察期内生存率达60%,显著高于OVA 257-264组(P<0.05)。结论成功构建了纳米颗粒疫苗OVA 257-264-mi3,其增强肿瘤抗原表位肽OVA 257-264免疫原性,在小鼠荷瘤模型中保护效果良好,为肿瘤新抗原疫苗的研究提供了理论基础。

Oral administration of Bacillus coagulans TQ-35 alleviates allergic responses in OVA-sensitive BALB/c mice

Bacillus coagulans has been extensively studied so far,but there has been a lack of research on its usage in allergy.In this study,we designed to assess the effect of different concentrations of B.coagulans on food allergy in a BALB/c mouse model of ovalbumin(OVA)-induced food allergy and its effect on gut microbes.The assessment of symptoms,specific immunoglobulin E(IgE),T-cell differentiation,and related gene expression levels in sensitized mice by assay indicated that high doses of oral B.coagulans could alleviate allergic symptoms.Treatment with B.coagulans,in the high-dose group,significantly reduced IgE and IgG1 levels and modulated the balance of T helper type 1 cell(Th1)and Th2 and the expression of relevant genes in the spleen.16S rRNA analysis showed that probiotics improved the structure of the microbiota,in particular by boosting the percentage of Clostridia,Bacteroides vulgatus and Enterococcus faecium,and by increasing the abundance of microbial species,thereby modulating the immune system.Therefore,this study can provide insights into the practical application of B.coagulans doses to alleviate OVA allergy.

MBD2 promotes Th2 differentiation in ovalbumin-induced CD4+T cells

Introduction:Allergen-specific CD4+T cells play a central role in autoimmune disorders,allergies and asthma,with Th2-type immunity being the typical functional response of CD4+T cells.This study aimed to investigate the role of MBD2 in regulating Th2 cell differentiation.Methods:Splenic mononuclear cells were extracted from C57BL/6 mice,and CD4+T cells were isolated using magnetic beads and confirmed through flow cytometry.Lentivirus was employed to construct MBD2-silenced CD4+T cells.In vitro experiments were performed to treat splenogenic mononuclear cells and CD4+T cells with Ovalbumin(OVA),and Th2 cell ratios and IL-4 levels were assessed using flow cytometry and ELISA.Results:The purity of the isolated CD4+T cells was 95.73%,confirming successful isolation of primary CD4+T cells.Compared to the control group,the Th2 cell ratio exhibited an increase in the Th2-induced group.Treatment with 5-Aza(concentrations,1-100μM)promoted Th2 cell differentiation and increased IL-4 levels.Notably,when combined with Th2 induction and 10μM 5-Aza treatment,silencing MBD2 further amplified Th2 cell ratios and elevated IL-4 levels in cell supernatants.Furthermore,OVA(concentration,200μg/mL)induced the differentiation of CD4+T cells into Th2 cells and increased IL-4 secretion.Interestingly,silencing MBD2 significantly increased the Th2 cell ratio and IL-4 levels in OVA-treated CD4+T cells.Conclusion:In summary,OVA promoted CD4+T cell differentiation into Th2 cells and enhanced IL-4 levels.MBD2 was identified as a mediator of Th2 cell differentiation in splenic-derived CD4+T cells,influenced by OVA or 5-Aza treatment.

芒柄花素磺酸钠通过MAPKS信号通路缓解OVA诱导哮喘小鼠肺部炎症

[目的]观察芒柄花素磺酸钠对卵清蛋白(OVA)诱导哮喘小鼠的保护作用及其机制。[方法]购买SPF级C57BL/6小鼠60只,并随机分6组,每组10只,具体组别如下:空白对照组(CON组)、模型组(OVA组)、芒柄花素磺酸钠低剂量(MBHS-L组)、芒柄花素磺酸钠中剂量(MBHS-M组)、芒柄花素磺酸钠高剂量(MBHS-H组)和地塞米松组(DEX组),使用OVA诱导建立小鼠哮喘模型。实验主要评价小鼠哮喘症状并进行评分、计量支气管肺泡灌洗液(BALF)中炎症细胞数量(Diff-Quick染色法)、镜下观察肺组织的病理学变化[苏木精-伊红(HE)染色法]、分析BALF中超氧化物歧化酶(SOD)活性和肿瘤坏死因子α(TNF-α)、白细胞介素1β(IL-1β)、白细胞介素6(IL-6)和丙二醛(MDA)水平(ELISA法和化学发光法)、分析肺组织p-ERK1/2,p-JNK和p-p38MAPK蛋白表达水平(免疫荧光法和Western blot法)。[结果]与OVA组比较,哮喘症状评分、BALF炎症细胞数量、TNF-α、IL-1β和MDA水平以及p-ERK1/2,p-JNK和p-p38MAPK蛋白表达水平在MBHS组和DEX组均明显降低(P<0.05),而SOD的活性明显升高(P<0.05),肺组织病理学变化明显改善。[结论]芒柄花素磺酸钠可能通过MAPKS信号通路缓解OVA诱导哮喘小鼠的肺部炎症。

β-谷甾醇对OVA诱导的过敏性哮喘大鼠模型中Th17/Treg免疫失衡的调节

目的:探讨β-谷甾醇对卵白蛋白(OVA)诱导的过敏性哮喘大鼠的干预作用及潜在作用机制。方法:SD雄性大鼠随机分为正常组(CON)、模型组(M)、阳性药地塞米松组(DEX,0.075 mg/kg)、β-谷甾醇组(Sit,50 mg/kg),采用腹腔注射OVA氢氧化铝溶液致敏,雾化吸入OVA激发建立过敏性哮喘大鼠模型。雾化激发前30 min灌胃给药,连续给药7 d后,检测大鼠咳喘指标、气管酚红排泌量;HE染色观察肺组织病理变化;流式细胞术检测大鼠原代肺细胞活性氧(ROS)、凋亡水平及外周血中Th17和Treg细胞比例;生化法检测大鼠肺组织中MDA含量及T-SOD、GSH-Px活力;ELISA检测Th17、Treg相关细胞因子(TNF-α、IL-4、IL-6、IL-17A、IL-35)水平。结果:与模型组相比,β-谷甾醇明显延长了过敏性哮喘大鼠的咳嗽及引喘潜伏期,减少了咳嗽及喘息次数,促进了气管酚红排泌;显著减轻了哮喘大鼠肺组织炎症浸润;显著降低了哮喘大鼠肺组织MDA含量、原代肺细胞ROS和凋亡水平,提高了T-SOD及GSH-Px活力;显著降低了Th17细胞比例及促炎细胞因子TNF-α、IL-4、IL-6、IL-17A水平,提高了Treg细胞比例及抑炎细胞因子IL-35水平。结论:β-谷甾醇能够改善OVA诱导的过敏性哮喘大鼠气道炎症和氧化损伤,其作用机制可能与β-谷甾醇对Th17/Treg免疫失衡及氧化应激反应的调节有关。

Protective effect of Bifidobacterium infantis CGMCC313-2 on ovalbumin-induced airway asthma and b-lactoglobulininduced intestinal food allergy mouse models

AIM To determine whether oral administration of Bifidobacterium infantis CGMCC313-2(B. infantis CGMCC313-2) inhibits allergen-induced airway inflammation and food allergies in a mouse model.METHODS Ovalbumin(OVA)-induced allergic asthma and b-lactoglobulin-induced food allergy mouse models were used in this study. Following oral administration of B. infantis CGMCC313-2 during or after allergen sensitization, histopathologic changes in the lung and intestine were evaluated by hematoxylin and eosin(HE) staining. In the allergic asthma mouse model, we evaluated the proportion of lung-infiltrating inflammatory cells. OVAspecific IgE and IgG1 levels in serum and cytokine levels in bronchoalveolar lavage fluid(BALF) were also assessed. In the food allergy mouse model, the levels of total Ig E and cytokines in serum were measured.RESULTS Oral administration of B. infantis CGMCC313-2 during or after allergen sensitization suppressed allergic inflammation in lung and intestinal tissues, while the proportion of infiltrating inflammatory cells was significantly decreased in the BALF of allergic asthma mice. Moreover, B. infantis CGMCC313-2 decreased the serum levels of total Ig E in food allergy mice, and reductions in IgE and IgG1 were also observed in OVA-induced allergic asthma mice. The expression of interleukin-4(IL-4) and IL-13 in both serum and BALF was suppressed following the administration of B. infantis CGMCC313-2, while an effect on serum IL-10 levels was not observed.CONCLUSION B. infantis CGMCC313-2 inhibits the secretion of allergen-induced IgE, IL-4 and IL-13, and attenuates allergic inflammation.

定喘颗粒对OVA诱导豚鼠急性哮喘的作用研究

目的探讨定喘颗粒对于卵清蛋白(Ovalbumin,OVA)诱导的豚鼠急性哮喘模型的影响。方法通过腹腔注射OVA溶液并进行行为学评分后,随机分为模型组、硫酸特布他林组、喘嗽宁片组、定喘颗粒低剂量组、定喘颗粒中剂量组、定喘颗粒高剂量组,并从未处理豚鼠中随机选取8只作为空白组。在给药2周后通过OVA喷雾进行刺激,检测模型组及各给药组中豚鼠的引喘潜伏期,利用酶联免疫吸附测定(Enzyme linked immunosorbent assay,ELISA)检测豚鼠血清和支气管肺泡灌洗液(Bronchoalveolar lavage fluid,BALF)中白细胞介素-4(Interleukin-4,IL-4)和白细胞介素-10(Interleukin-10,IL-10)的水平,并借助嗜酸粒细胞直接计数液检测全血和BALF中嗜酸性粒细胞(Eosinophil,EOS)的数量,苏木素-伊红(Hematoxylin-eosin,HE)染色检测豚鼠肺部组织的病理变化情况并评估。结果与空白组相比,模型组炎症相关指标出现明显异常,指示造模成功。与模型组相比,阳性药组尤其是硫酸特布他林片组,以及定喘颗粒高剂量组给药均可延长OVA诱发急性支气管哮喘豚鼠的引喘潜伏期,降低血液及BALF中IL-4和IL-10的水平和EOS的数量,并缓解肺部组织的病理变化。结论定喘颗粒可以有效缓解急性哮喘时出现的炎症情况,并减少哮喘相关炎症导致的肺部病理损伤。

Structural and functional properties of hydrolyzed/glycosylated ovalbumin under spray drying and microwave freeze drying

Ovalbumin(OVA),the main protein in egg white,affects most of the functional properties of egg white protein in food processing.The aim of this study was to investigate the effects of spray drying(SD)and microwave freeze drying(MFD)on the preparation of hydrolyzed/glycosylated ovalbumin(HGOVA)and provide useful information on the applications of egg protein powders in the food industry.Results demonstrated that the structure of HGOVA was considerably changed,and its functional properties were improved compared with those of native OVA.SD and MFD processing did not lead to dissociation of HGOVA subunits.SD-HGOVA exhibited higher protein solubility,emulsifying activity,foaming capacities,and gel hardness than MFD-HGOVA.However,MFD-HGOVA was better than the SD-HGOVA in terms of color,emulsion stability,foam stability,water/oil absorption capacity,and thermal stability.Selection of an appropriate drying method could enhance the potential applications of HGOVA in the food industry.

The influence of Trichosanthin on the induction of IgE responses to ovalbumin under adjuvant-free condition

Trichosanthin(TCS) is a potent allergen in mice. It can reproducibly induce specific IgE responses in C57BL/6J mice without the help of adjuvant alum. TCS can bring out the IgE responses to ovabumin(OVA), while OVA itself could not induce IgE responses to it. How- ever, TCS only works when QVA immunization is given one day after TCS immunization. Either time lag in OVA immunization, or immunization of both antigens at the same time, or OVA immunization given first, all has no effect on the induction of IgE responses to OVA. Through analysis of the antibody specificity of hybridoma clones, it indicated that specific antibodies to TCS or OVA were secreted by independent B cell clones. The IgE antibodies showed no polyreactivity to different antigens.

Preparation and Characterization of β-Cyclodextrin Derivatized Ovalbumin Used as Chiral Selector in Pressure Capillary Electrochromatography

Synthesis and properties of β-cyclodextrin derivatized ovalbumin used as chiral selector were investigated, β-cyclodextrin derivatized ovalbumin was synthesized using β-cyclodextrin and ovalbumin in the presence of ethylene glycol diglycidyl ether in boric acid buffer at pH value 8.7 at 37℃. Amino group was coated on the internal surface of the silica capillary by sol-gel technology with triethoxylmethylsiloxane and （3-aminopropyl）trimethoxysiloxane. Covalent binding of g-cyclodextrin derivatized ovalbumin was performed by glutaraldehyde. Enantiomers of chlorpheniramine, phenylalanine and atropine were separated by pressure capillary electrochromatography column coated with β-cyclodextrin derivatized ovalbumin.

Cyclodextrin/chitosan nanoparticles for oral ovalbumin delivery: Preparation, characterization and intestinal mucosal immunity in mice

A novel oral protein delivery system with enhanced intestinal penetration and improved antigen stability based on chitosan(CS) nanoparticles and antigen-cyclodextrin(CD) inclusion complex was prepared by a precipitation/coacervation method. Ovalbumin(OVA) as a model antigen was firstly encapsulated by cyclodextrin, either β-cyclodextrin( β-CD) or carboxymethyl-hydroxypropyl-β-cyclodextrin(CM-HP-β-CD) and formed OVA-CD inclusion complexes, which were then loaded to chitosan nanoparticles to form OVA loaded β-CD/CS or CM-HP-β-CD/CS nanoparticles with uniform particle size(836.3 and 779.2 nm, respectively) and improved OVA loading efficiency(27.6% and 20.4%, respectively). In vitro drug release studies mimicking oral delivery condition of OVA loaded CD/CS nanoparticles showed low initial releases at p H 1.2 for 2 h less than 3.0% and a delayed release which was below to 30% at p H 6.8 for further 72 h. More importantly, after oral administration of OVA loaded β-CD/CS nanoparticles to Balb/c mice, OVA-specific sIgA levels in jejunum of OVA loaded β-CD/CS nanoparticles were 3.6-fold and 1.9-fold higher than that of OVA solution and OVA loaded chitosan nanoparticles, respectively. In vivo evaluation results showed that OVA loaded CD/CS nanoparticles could enhance its efficacy for inducing intestinal mucosal immune response. In conclusion, our data suggested that CD/CS nanoparticles could serve as a promising antigen-delivery system for oral vaccination.

Oral Administration Recombinant Bifidobacterium-LTB (B Subunit of Heat-Labile Enterotoxin) Enhances the OVA (Ovalbumin)-Specific sIgA in Jejunal Mucosa of Sprague-Dawley (SD) Rat

The LTB of enterotoxigenic Escherichia coli (ETEC) expressed in Bifidobacterium infantis (BI) has been testified as mucosal adjuvant with co-vaccination BI-CfaB (the major fimbrial subunit) together in vivo in our previous study. In order to investigate the mucosal adjuvant effect of BI-LTB to purified antigens, we oral vaccinated SD rats with recombinant BI-LTB plus OVA (rBI-LTB + OVA), and wild type BI plus OVA (wBI + OVA), OVA and PBS (Phosphate buffered saline) were vaccinated as controls, respectively. The OVA-specific sIgA in jejunal mucosa and specific IgG in serium were measured with ELISA (Enzyme-linked immunosorbent assay) and the sIgA producing cells were detected with immunohistochemistry technology (IHC) and Qwin image manipulation tools subsequently. The results shown rBI-LTB could stimulate SD rats produce high titer OVA-specific sIgA in rBI-LTB + OVA group and the OVA-specific sIgA titer in rBI-LTB + OVA group was found significant greater than that of the wBI + OVA group or OVA single group (p < 0.05). However no such significant difference was detected between the group wBI + OVA and OVA. IHC results suggested that intestinal mucosa and submucosa was the main field of sIgA secretion. These results suggested that recombinant LTB expression in BI could be used as a wide range mucosal adjuvant with different form antigens.

<i>Mycobacterium vaccae</i>Immunization to Pregnant BALB/c Mice Ameliorated Lung Histopathology and Bone Marrow Eosinophila in Ovalbumin Sensitized Offsprings

Context: One of the treatment strategies for atopic diseases is to skew immune response away from Th2 dominance by using Mycobacterial strains. Objective: We wanted to find out whether M. vaccae administration to pregnant mice had any preventive effect on the offsprings in the development of a murine asthma model. Materials and Methods: Pregnant BALB/c mice were divided into two groups;first group received heat-killed M. vaccae subcutaneously on 12th day of pregnancy and the latter group received PBS. After delivery, newborn mice of each group were further divided into two subgroups as M. vaccae/Ovalbumin (OVA), M. vaccae/control, PBS/OVA and PBS/ control. To establish experimental murine asthma model, mice were intraperitoneally sensitized and challenged intratracheally with Ovalbumin. We analysed airway histopathology, bone marrow eosinophil progenitors and splenic cell cytokine profiles of the offsprings. Results: Comparison of offsprings in M. vaccae/OVA group were not different than PBS controls with respect to thicknesses of airway epithelium, basement membrane, subepithelial smooth muscles and number of hyperplasic goblet cells as well as bronchial associated lymphoid tissue density and eosinophil progenitors in the bone marrow. Comparison of M. vaccae/OVA group to asthma model revealed significant differences and lower levels of OVA-induced IL-5. Conclusions: We propose that immunization of pregnant BALB/c with M. vaccae could prevent histopathological alterations in the airways related to the asthma model and down-regulates IL-5 secretion from splenocytes of offsprings.

Molecular dynamics simulations of ovalbumin adsorption at squalene/water interface

The adsorption of protein molecules to oil/water(O/W)interface is of critical importance for the product design in a wide range of technologies and industries such as biotechnology,food industry and pharmaceutical industry.In this work,with ovalbumin(OVA)as the model protein,the adsorption conformations at the O/W interface and the adsorption stability have been systematically studied via multiple simulation methods,including all-atom molecular dynamic(AAMD)simulations,coarse-grained molecular dynamic(CGMD)simulations and enhanced sampling methods.The computational results of AAMD and CGMD show that the hydrophobic tail of OVA tends to be folded under long time relaxation in aqueous phase,and multiple adsorption conformations can exist at the interface due to heterogeneous interactions raising from oil and water respectively.To further study the adsorption sites of the protein,the adsorption kinetics of OVA at the O/W interface is simulated using metadynamics method combined with CGMD simulations,and the result suggests the existence of multiple adsorption conformations of OVA at interface with the head-on conformation as the most stable one.In all,this work focuses on the adsorption behaviors of OVA at squalene/water interface,and provides a theoretical basis for further functionalization of the proteins in emulsion-based products and engineering.

The effect of inhibitor peptide for ADAM8 in attenuating ovalbumin-induced murine asthma

Targeted peptides have been identified as showing great promise for treatment of various diseases including asthma.Asthma is considered of difficuIt-to-treat due to its unclear etiology,thus usually requiring life-long treatment.Current strategies for asthma therapy are hampered with undesirable side effects,poor targeting and failure in modulating airway hyperresponsiveness,leading to pressing need of developing more targeted and effective therapeutic sites for asthma.Recently,a disintegrin and metalloproteinase 8(ADAM8)have been shown to over-

使用致敏因子OVA构建大鼠分泌性中耳炎模型

目的探讨鸡卵白蛋白(OVA)在SD大鼠建立分泌性中耳炎动物模型中的作用。方法将40只SPF级SD大鼠按随机数字表法分为对照组和造模组,各20只。通过程序性注射致敏因子OVA,使用耳内镜和解剖评估小鼠中耳积液情况,并通过HE染色光镜下观察鼓室黏膜组织形态。结果20只模型组大鼠中有32耳鼓膜内陷,光锥消失,打开听泡可见鼓室积液,HE染色可见鼓室黏膜明显增厚。结论采用OVA全身给药联合耳内注射可以建立分泌性中耳炎大鼠动物模型,为进一步的基础研究提供基础。

OVA7000型在线重金属分析仪的维护方法

OVA7000在线重金属分析仪是英国Modern Water旗下MTI公司的OVA/PDV系列重金属检测产品,采用阳极溶出伏安法,具有检出限低、准确度高、耗材消耗少等特点,并且抗干扰能力强,有可集成多监测因子于一台仪器的优点,是地表水自动监测中较为普遍采用的水环境质量自动监测仪器。本文介绍了分析原理、仪器组成,并根据多年经验总结了维护方法,希望对使用OVA7000型在线重金属分析仪的技术人员有所帮助,为水环境的重金属监测提供质量保障。