食品致敏性评价啮齿类动物模型研究——C3H/HeJ小鼠动物模型

目的研究C3H/HeJ小鼠作为食品致敏性评价动物模型的可行性,探讨不同致敏途径适当的致敏周期以及辅助性T淋巴细胞因子的变化。方法通过经口灌胃及腹腔注射两种途径给予雌性C3H/HeJ小鼠致敏蛋白——卵清蛋白(OVA),共35天。分别在第14、28、35天内眦取血分离血清,测定OVA特异性IgE。于第35天取脾脏,荧光实时定量PCR检测Th2型细胞因子IL-4及Th1型细胞因子IFN-γ的mRNA表达水平。结果与阴性对照组相比,经口灌胃OVA组小鼠第28和35天血清中OVA特异性IgE浓度显著升高(P0.05);腹腔注射OVA+Al(OH)3组小鼠第14、28和35天血清中OVA特异性IgE浓度显著升高(P0.05)。与阴性对照组相比,OVA组与OVA+Al(OH)3组小鼠细胞因子IL-4的表达水平均显著升高;细胞因子IFN-γ的mRNA表达水平均显著降低。结论C3H/HeJ小鼠可以作为食品致敏性评价动物模型,经口灌胃途径及腹腔注射途径的最佳致敏周期分别为14天和28天。     

BALB/c小鼠食物过敏动物模型的实验研究

目的　BALB/ c小鼠作为食物过敏动物模型的可行性一直存在争议 ,本研究探讨BALB /c小鼠作为食物过敏动物模型的可行性。方法　对相应试验组动物分别腹腔注射 0 . 2 5ml 2 0mg/ ml卵清蛋白 (OVA)、牛血清白蛋白 (BSA)、大豆胰蛋白酶抑制剂 (TI)和马铃薯酸性磷酸酶 (PAP )共两次 ,间隔为一周。检测血浆中的组胺水平和血清中特异IgE抗体含量 ,同时进行皮肤过敏反应实验 (PCA)。结果　OVA、BSA、TI及PAP组32倍稀释血清中均可检测到特异IgE抗体 ;血浆中组胺水平较对照组显著升高。常见致敏食物蛋白质OVA和TI、不常见致敏食物蛋白质BSA和无致敏史食物蛋白质PAP均可使BALB/ c小鼠产生过敏反应。结论　BALB c小鼠不适合作为食物过敏动物模型。     

三氯乙烯致豚鼠皮肤变态反应和血清免疫球蛋白水平改变

目的:探讨三氯乙烯(TCE)对豚鼠皮肤变态反应和血清免疫球蛋白水平的改变。方法:采用豚鼠最大值试验GPMT,动物分成阴性对照组、阳性对照组和TCE实验组,每组6只豚鼠,分别皮内注射橄榄油、2,4-二硝基氯苯(DNCB)和TCE。实验结束后观察动物皮肤改变,应用自动生化分析仪检测致敏动物血清免疫球蛋白水平。结果:阳性对照组和TCE实验组动物出现明显皮肤损害,阳性对照组动物致敏率为100%,TCE实验组致敏率为83.3%。TCE致敏豚鼠血清总IgG含量明显高于阴性对照组(P0.05)。结论:三氯乙烯属于强致敏物,可诱导豚鼠产生皮肤变态反应,引起血清免疫球蛋白改变。     

蛋白过敏性研究——BN大鼠动物模型

目的　用BN大鼠模型探讨不同蛋白的过敏性。方法　通过腹腔注射 (1mg ml)或口服 (10mg ml)给予BN大鼠卵清蛋白 (OVA)或牛血清白蛋白 (BSA) ,时间为 6周。在不同时间取血清 ,进行被动皮肤致敏试验 (PCA) ;分离血浆进行组胺测定 ;此外 ,对OVA组和对照组的大鼠进行血压测定。结果　PCA试验结果表明OVA特异性IgE抗体滴度较高 (1 32～ 1 12 8) ,而BSA特异性IgE抗体滴度较低 (1 2～ 1 4 )。与对照组相比 ,腹腔注射或口服OVA均使组胺水平升高。口服OVA对大多数大鼠的血压没有明显的影响 ,然而 ,有 2只大鼠收缩压暂时降低。结论　该研究结果表明BN大鼠模型可能是一种较理想的蛋白过敏性模型。     

三氯乙烯对豚鼠皮肤致敏作用与肝肾功能的损害

目的 探讨三氯乙烯(TCE)对豚鼠皮肤致敏作用及肝肾功能的损害.方法 采用豚鼠最大值试验(GPMT),将动物分成阴性对照组、阳性对照组和TCE实验组,每组6只豚鼠,分别皮内注射橄榄油、2,4-二硝基氯苯(DNCB)和TCE.实验结束后观察动物皮肤改变,应用自动生化分析仪检测致敏动物血清中丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、白蛋白、球蛋白、乳酸脱氧酶(LDH)、肌苷、尿酸等指标.结果阳性对照组和TCE实验组动物出现明显皮肤红斑、水肿,阳性对照组动物致敏率为100%,TCE实验组动物致敏率为83.3%.阳性对照组动物血清中ALT、AST活力升高,TCE实验组动物血清中ALT、AST、LDH活力明显高于阴性对照组,差异有统计学意义(P＜0.05或P＜0.01).结论 TCE可诱导豚鼠产生明显的皮肤致敏作用,属强致敏物,并可引起实验动物肝功能指标的改变.     

转HJC-1和G6-EPSPS基因抗虫耐除草剂大米对BN大鼠致敏性评价

目的 利用BN大鼠对转HJC-1和G6-EPSPS基因抗虫耐草甘膦大米进行致敏性评价.方法 42只BN大鼠随机分为7组,每组6只,分别为溶剂对照组、饲养对照组、亲本大米组、转基因大米组、HJC表达蛋白组、G6表达蛋白组和阳性对照组.转基因大米组喂饲含70％转HJC-1和G6-EPSPS基因大米饲料,亲本大米组喂饲含70％的9746亲本大米饲料,表达蛋白组每天每只动物分别灌胃给予1.0 mg/ml HJC和G6蛋白各1 ml,阳性对照组每天每只灌胃给予1.0 mg/ml OVA溶液1 ml,溶剂对照组每天每只灌胃给予PBS 1 ml,连续42 d.各组动物饲料均不含卵蛋白.观察动物体重、行为、毛色、分泌物等毒性表现及死亡情况,每周称重并记录体重,分别于第28天和第42天使用ELISA试剂盒测定血清抗体IgG和IgE水平,试验结束时称重并计算脾和胸腺脏器系数.结果 实验期间各组动物进食正常,活动自如,未出现生病或死亡,各组动物体重及总增重差异无统计学意义.与溶剂对照组和饲养对照组比较,HJC和G6表达蛋白组、转基因大米组血清IgG、IgE抗体水平及脾和胸腺脏器系数差异均无统计学意义.阳性对照组血清IgG、IgE抗体水平高于溶剂对照组,差异有统计学意义(P＜0.05).结论 全食品喂饲及灌胃给予表达蛋白未发现转HJC-1和G6-EPSPS基因抗虫耐草甘膦大米对BN大鼠血清IgG和IgE抗体水平及免疫器官产生不良影响,未见其对BN大鼠具有潜在致敏性.     

一例梅毒螺旋体抗体颗粒凝集吸收试验假阳性的原因分析

2004年4月13日在出国劳务人员梅毒螺旋体抗体(TP-Ab)血清学检测中,发现反应模式特殊1例.原血清试验结果是:甲苯胺红不加热血清试验(TRUST)阴性.梅毒螺旋体特异性抗体酶联免疫吸附试验(TP.ELISA)阴性.梅毒螺旋体颗粒凝集试验(TP.PA)未致敏颗粒阳性(++),致敏颗粒阳性(+).梅毒螺旋体血细胞凝集试验(TP.HA)未致敏血细胞阳性(+),致敏血细胞阳性(++).用TPPA未致敏颗粒对血清吸收后的试验结果是:TPPA未致敏颗粒阴性(-),致敏颗粒阴性(-).对吸收前后的双份血清标本检测类风湿因子(RF)和抗双链DNA(Ds-DNA)抗体结果是:均为阴性.说明TP-Ab检测实际操作中对特殊标本吸收试验是非常重要的.     

内毒素在小鼠过敏性哮喘模型所起作用的实验研究

目的建立小鼠过敏性哮喘模型,在过敏原的致敏和激发阶段给予不同剂量内毒素(即脂多糖LPS),探讨内毒素在哮喘模型中的作用机制。方法建立BALB/c小鼠哮喘模型,设立实验组和对照组开展后续实验。实验组包括:鸡卵清白蛋白(OVA)致敏,OVA激发组;OVA致敏,LPS激发组;OVA致敏,OVA+LPS联合激发组;LPS暴露于OVA致敏前,OVA激发组;对照组包括试剂对照组和健康对照组。各实验组的LPS剂量均分为高、中、低三个剂量组。通过测定小鼠气道阻力和肺顺应性来反映其肺功能改变;流式细胞术(FCM)测定FITC、PE阳性细胞数,表征CD4+CD2+5调节性T淋巴细胞(以下简称Treg细胞)的相对比例;荧光实时聚合酶链反应定量测定肺脏和脾脏Foxp3mRNA表达的水平;ELISA法测定血浆总IgE和OVA特异性IgE水平,抗体夹心ELISA法测定支气管肺泡灌洗液(BALF)中Th2细胞因子(IL-4和IL-5)的水平;计数BALF中白细胞总数和嗜酸性粒细胞等各类白细胞所占百分比;常规病理切片观察肺组织改变情况。结果结果表明,与哮喘模型组小鼠相比,在LPS各处理组中,总体上能诱导Treg细胞的产生,改善肺功能,降低IgE滴度,降低Th2介导的免疫反应,同时诱导肺部炎症。尤其是在致敏阶段腹腔注射内毒素可以缓解由过敏原诱导的气道炎症和改善肺功能,诱导肺组织和脾组织Foxp3mRNA表达的增加。结论LPS抑制了Th2介导的过敏反应,可能与Foxp3表达量的增加相关,后者诱导Treg细胞增殖,对哮喘症状起到缓解作用。     

肺炎支原体抗体与血清总IgE检验在小儿肺炎诊断中的应用

目的:在小儿肺炎诊断中,肺炎支原体抗体与血清总IgE的临床意义与价值。方法:随机选取太原市中医院2017年1月至2018年12月235例肺炎患儿,根据支原体抗体检测结果,分为阴性组(167例)、低滴度组(45例)、高滴度组(23例),同时选取200例无呼吸道感染的患儿作为对照组,给予血清总IgE的检测。结果:观察组中支原体抗体阴性组的IgE阳性数68例(水平78.9±20.34),低滴度组的IgE阳性数27例(水平125.56±19.21),高滴度组的IgE阳性数18例(水平260.39±24.31),均高于对照组,其IgE阳性数为0(水平21.23±5.67),且差距具有统计学意义(P0.05)。随着支原体抗体滴度的升高,血清总IgE的阳性率越高,进行组间两两比较,其差距均具有统计学意义(P0.05)。结论:在小儿肺炎的诊断中,同时采用肺炎支原体抗体及血清IgE的检测,可以提高诊断率,对于临床小儿肺炎的早期诊断、早期治疗具有重要意义。     

BN大鼠致敏动物模型研究

目的建立经腹腔注射途经给予造模致敏原的BN大鼠致敏动物模型。方法分别在实验第1、5和10天,经腹腔注射给予不同性别(雌性和雄性)和不同周龄(4周龄和8周龄)的BN大鼠,不同剂量(1.00、0.10和0.01mg)的造模致敏原———卵清蛋白(OVA),观察35天。分别于第28、35天内眦取血分离血清,用ELISA方法检测血清中OVA特异性IgE。结果与阴性对照组相比,雌性8周龄BN大鼠中、高剂量组第28、35天血清中OVA特异性IgE浓度显著升高(P<0.05);雄性8周龄BN大鼠低、中剂量组血清中OVA特异性IgE浓度在第28天显著升高(P<0.05),高剂量组血清中OVA特异性IgE浓度在第35天显著升高(P<0.05);雄性4周龄BN大鼠,高剂量组血清中OVA特异性IgE浓度在第35天显著升高(P<0.05)。结论经腹腔注射途径给予不同性别和周龄的BN大鼠不同剂量的OVA,雌性大鼠比雄性大鼠更敏感;8周龄大鼠比4周龄大鼠更敏感;0.10mg或1.00mg的致敏剂量较适合。因此,选用雌性8周龄BN大鼠,经腹腔注射给予0.10mg或1.00mgOVA,35天后即可建立比较理想的BN大鼠致敏动物模型。     

Gastric Enzyme Supplementation Inhibits Food Allergy in a BALB/c Mouse Model

Impaired gastric digestion due to suppressed gastric acidity enhances the risk for food allergy development. In the current study, we aimed to evaluate the impact of a supported gastric digestion via application of a pharmaceutical gastric enzyme solution (GES) on food allergy development and allergic reactions in a BALB/c mouse model. The ability of the GES to restore hypoacidic conditions was tested in mice treated with gastric acid suppression medication. To evaluate the impact on allergic symptoms, mice were orally sensitized with ovalbumin (OVA) under gastric acid suppression and subjected to oral challenges with or without GES. The immune response was evaluated by measurement of antibody titers, cytokine levels, mucosal allergy effector cell influx and regulatory T-cell counts. Clinical response was objectified by core body temperature measurements after oral OVA challenge. Supplementation of GES transiently restored physiological pH levels in the stomach after pharmaceutical gastric acid suppression. During oral sensitization, supplementation of gastric enzymes significantly reduced systemic IgE, IgG1 and IgG2a levels and allergic symptoms. In food allergic mice, clinical symptoms were reduced by co-administration of the gastric enzyme solution. Support of gastric digestion efficiently prevents food allergy induction and alleviates clinical symptoms in our food allergy model.     

三氯乙烯致敏豚鼠单核淋巴细胞中β-arrestin蛋白表达和核转录因子及激活蛋白-1活性的研究

目的 测定三氯乙烯(TCE)致敏豚鼠外周血单核淋巴细胞(PBMC)中β-arrestin蛋白表达水平,核转录因子(NF-κB)和激活蛋白-1(AP-1)活性以及血清中肿瘤坏死因子(TNF-α)水平,探讨TCE致敏中免疫反应调节机制.方法 根据豚鼠最大值试验方法,用TCE对豚鼠进行处理(TCE处理组,14只),同时设立空白对照(5只)和DNCB阳性对照(7只),对受试动物进行皮肤反应评分,据此判断致敏与否,并把TCE处理组分为TCE致敏组和TCE未致敏组.提取豚鼠外周血单核细胞(PBMC),用免疫蛋白印迹(Western bloting)法检测β-arrestin蛋白表达水平,用电泳迁移率试验(EMSA)方法检测NF-κB和AP-1活性.酶联免疫吸附(ELISA)试剂盒检测血清中TNF-α水平.结果 空白对照组豚鼠未见红斑或水肿,TCE组的部分豚鼠皮肤出现红斑和水肿,致敏率为71.4%,DNCB处理组所有动物皮肤出现明显红斑或水肿,致敏率为100%.空白对照、TCE未致敏组、TCE致敏组和DNCB处理组豚鼠PBMC中β-arrestin蛋白表达水平比较,差异无统计学意义(P>0.05).与空白对照组和TCE未致敏组相比,TCE致敏组NF-κB活性明显升高,且差异有统计学意义(P<0.05);而各组豚鼠AP-1活性比较,差异无统计学意义(P>0.05).TCE致敏组血清中TNF-α水平[(55.485+8.732)pg/ml]较空白对照组[(32.118±12.550)pg/ml]明显升高,差异有统计学意义(P<0.05).结论 以TCE致敏豚鼠β-arrestin和AP-1可能没被激活,而NF-κB被明显激活且在TCE致敏免疫反应中发挥着调节作用.     

Assessment of the allergic potential of food protein extracts and proteins on oral application using the brown Norway rat model

The need for widely accepted and validated animal models to test the potential allergenicity and potency of novel (biotechnology-derived) proteins has become an important issue for their safety evaluation. In this article, we summarize the results of the development of an oral sensitization protocol for food proteins in the rat. Young Brown Norway rats were exposed to either various purified allergenic proteins (e.g., ovalbumin, partly purified), a whole food (cow's milk), or total protein extracts (hen's egg white, peanut) by daily gavage dosing during 42 days without the use of an adjuvant. The results showed that Brown Norway rats can be sensitized orally to the various allergenic food proteins tested, resulting in antigen-specific immunoglobulin (Ig) G and IgE responses, without the use of adjuvants. Animals orally exposed to cow's milk or total protein extracts of egg white also developed specific IgE and IgG antibodies that recognized the same proteins compared with antibodies from patients allergic to egg white or cow's milk. We also studied local and systemic immune-mediated effects. In ovalbumin-sensitized rats, some clinical symptoms of food allergy were studied upon an oral challenge with ovalbumin. The results demonstrated that gut permeability was increased and that in some animals breathing frequency and systolic blood pressure were temporarily decreased. The results obtained show that the Brown Norway rat provides a suitable animal model for food allergy research and for the study of relative allergenicity of existing and novel food proteins.     

槐耳颗粒对哮喘模型TGF-β表达的干预作用

目的:观察槐杞黄颗粒对哮喘模型肺组织转化生长因子-β(transforming growth factor-β,TGF-β)表达的干预作用。方法:将60只BALB/c哮喘模型鼠随机分为空白对照组、哮喘模型组及槐杞黄颗粒干预组(每组20只);除空白对照组外其他各组小鼠在试验第1天、第7天和第14天通过腹腔注射0.2 ml混有40 mg氢氧化铝和10μg OVA的pH7.4的PBS液致敏,在试验第15天用5%的OVA对小鼠进行雾化激发,连续一周;槐杞黄颗粒干预组在致敏阶段即每日加用槐杞黄颗粒胃内注入5 g/d,时间为1个月;所有小鼠在实验1个月后杀死,分别用ELISA以及免疫组化方法检测血中IgE、IL-4水平以及肺组织TGF-β的表达。结果:槐杞黄颗粒干预组1个月后血中IgE、IL-4水平及肺组织TGF-β的表达明显低于哮喘模型组,血中的IFN-γ水平较哮喘模型组明显增多,差异均有统计学意义(P<0.05)。结论:槐杞黄颗粒长期使用可能会逆转过敏性炎症,并且对哮喘模型肺组织TGF-β的表达有明显的抑制作用。     

Selenium Modulates the Allergic Response to Whey Protein in a Mouse Model for Cow’s Milk Allergy

Cow’s milk allergy is a common food allergy in infants, and is associated with an increased risk of developing other allergic diseases. Dietary selenium (Se), one of the essential micronutrients for humans and animals, is an important bioelement which can influence both innate and adaptive immune responses. However, the effects of Se on food allergy are still largely unknown. In the current study it was investigated whether dietary Se supplementation can inhibit whey-induced food allergy in an animal research model. Three-week-old female C3H/HeOuJ mice were intragastrically sensitized with whey protein and cholera toxin and randomly assigned to receive a control, low, medium or high Se diet. Acute allergic symptoms, allergen specific immunoglobulin (Ig) E levels and mast cell degranulation were determined upon whey challenge. Body temperature was significantly higher in mice that received the medium Se diet 60 min after the oral challenge with whey compared to the positive control group, which is indicative of impaired anaphylaxis. This was accompanied by reductions in antigen-specific immunoglobulins and reduced levels of mouse mast cell protease-1 (mMCP-1). This study demonstrates that oral Se supplementation may modulate allergic responses to whey by decreasing specific antibody responses and mMCP-1 release.     

双酚A对成年雄性小鼠体质量、摄食和肝功能的影响

目的 探讨双酚A对成年雄性小鼠体质量、摄食和肝功能的影响.方法 100只成年雄性ICR小鼠随机分为阴性对照组、己烯雌酚对照组、双酚A 2、20、100 mg/kg组,各组动物用相应受试物连续灌胃2周,于第8周将小鼠处死.用酶化学方法检测丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)、γ-谷氨酞基转移酶(GG...     

Diagnostic model for sensitization in workers exposed to occupational high molecular weight allergens

BACKGROUND: Occupational allergy has great impact on workers exposed to high molecular weight (HMW) allergens. The present study is aimed to develop and validate a generic diagnostic model for sensitization to HMW allergens, defined as positive IgE. METHODS: The model was developed in pooled data from Dutch laboratory animal (LA) workers and bakers using logistic regression analysis. Validity was assessed internally by bootstrapping procedure, and externally in British LA workers. RESULTS: The model included working hours/week, work-related symptoms, total IgE, and IgE to common allergen. Significant interactions between the type of work and the predictors resulted in different scores for LA workers and bakers. Internal and external validation showed that the model was satisfactorily calibrated and discriminated between workers at high and low risk of being sensitized. CONCLUSIONS: It is possible to develop a generic model for sensitization to occupational HMW allergens. However, the weighing of predictors differs across specific work environments.