高效液相色谱法测定饲料及食品中三聚氰胺的研究

目的：建立用高效液相色谱-二极管阵列法（HPLC-DAD）测定饲料及食品中三聚氰胺残留量的方法。方法：样品经提取分离后,用HPLC-DAD法测定,外标法定量。色谱条件：C18色谱柱（150mm×4.6mm,5μm）;流动相为乙腈-辛烷磺酸钠溶液（柠檬酸调节pH至3.0,10∶90）,流速为1.0ml/min;进样量为20μl;柱温为35℃;190～400nm波段扫描,检测波长为236nm。结果：三聚氰胺在0.5～10.0μg/ml范围内线性关系良好,相关系数R=0.99998。最低检测浓度为0.05μg/ml,回收率在89.28%～96.89%范围内,RSD〈3.5%。结论：该方法简便、快速,能满足饲料及食品中三聚氰胺残留量的检验工作需要。     

Policy formation in gamete donation and egg sharing in the UK--a critical appraisal

This article considers two key policy documents concerning donor-assisted conception in the UK, The British Fertility Society's Recommendations for Good Practice on the Screening of Egg and Embryo Donors and the Human Fertilisation and Embryology Authority's Guidance for Egg Sharing Arrangements. It discusses both the process and the evidence used in formulating those sections of the documents which relate to donor anonymity. The paper concludes that psycho-social policy developments in assisted conception, such as those relating to donor anonymity, should be subjected to comparable levels of rigour and scrutiny to those that are applied in the formulation of medical and scientific policies.     

超高效液相色谱-串联质谱法测定鸡肉和鸡蛋中5种硝基咪唑类药物残留量

目的 采用超高效液相色谱-串联质谱法(UPLC-MS/MS),建立鸡肉和鸡蛋中5种硝基咪唑类药物的检测方法。方法 样品经乙腈提取后,加入无水Na₂SO₄和NaCl,离心后上清液通过PRiME HLB固相萃取小柱净化,滤出液和乙腈洗脱液经氮吹至近干,10%甲醇水(v/v)溶液定容。以0.1%甲酸水-甲醇为流动相,被测物经BEH C18柱(2.1 mm×100 mm,1.7μm)分离、正离子多反应监测模式检测,内标法定量。结果 5种硝基咪唑在0.2～20.0 ng/ml范围内相关系数均大于0.999,方法检出限为0.05～0.10μg/kg,定量限为0.15～0.30μg/kg。在3个加标水平下(0.25、2.0和10.0μg/kg),鸡肉和鸡蛋的平均回收率分别为97.9%～106.0%和97.8%～110.0%,相对标准偏差(RSD)分别为0.9%～6.4%和1.0%～4.7%。结论 该方法简便、灵敏、准确,适用于鸡肉和鸡蛋中5种硝基咪唑残留量的快速检测。     

乳房日本血吸虫病1例

本文报道1例乳房血吸虫病病例。     

特异抗内毒素鸡蛋黄免疫球蛋白效价测定及理化性质研究

目的：研究特异性抗内毒素鸡蛋黄免疫球蛋白理化性质，探索一种防治肠源性感染，治疗：内毒素血症的新途径。方法：用大肠杆菌J5株(菌体表面类脂A裸露)作抗原免疫25周龄Roman鸡，制备特异性抗内毒素IgY，用酶联免疫吸附技术检测其效价及对热、酸、碱和酶的稳定性。结果：IgY抗体效价为1：25 600，能耐受巴氏消毒，对酸、碱、酶有很好的稳定性。结论：用大肠杆菌J5株免疫鸡制备的IgY效价高，理化性质稳定，适合口服应用。     

蛋清容积的大小对双针射频热凝范围的影响

目的:观察双极射频模式下不同蛋清容积形成热凝物的形态.方法:选用三个大小不同的圆柱形容器A、B和C,其体积分别为83 183.3 mm3、49 334.1 mm3、32 046.8 mm3.使用工作端长度为10 mm,20 G baylis电极针,在双极射频模式下,以不同的间距分别平行固定在盛满蛋清的A容器、B容器和C容器中,均给予90℃、900 s射频热凝.对形成的热凝物表面形态摄像并进行相关指标的测量分析.结果:在条件相同的双极射频模式下,A容器、B容器和C容器分别在电极间距为12 mm、20 mm和24 mm形成最大带状热凝物.其最大热凝面积分别为181.1 mm2、272.4 mm2和432.8 mm2.结论:相同实验条件下,减小容器容积,可增大形成带状热凝物的两电极最大间距和热凝物面积,但电极针外侧热凝物长度基本没有明显变化.     

Suppression of IgE-mediated anaphylaxis and food allergy with monovalent anti-FcεRIα mAbs

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Molecular and immunological analysis of hen’s egg yolk allergens with a focus on YGP42 (Gal d 6)

Allergy to hen’s (Gallus domesticus) egg white is one of the most common forms of food allergy. Allergy to hen’s yolk also exists however, to a lesser extent when compared to egg white allergy. Two minor allergens from the hen’s egg yolk known as α-livetin (Gal d 5) and YGP42 (Gal d 6) were discovered recently. In this study, we investigated whether sensitization to egg white is associated with reactivity to egg yolk as well. Sera obtained from 25 patients with allergy to egg white were tested for specific IgE binding for egg yolk proteins through western immunoblotting. 36% of patients were found with true IgE-sensitization against egg yolk proteins. It was found that most of the IgE reactive yolk proteins were fragments of major precursor proteins of hen; vitellogenin-1 (VTG-1), vitellogenin-2 (VTG-2) and apolipoprotein B (Apo B). The egg yolk allergen Gal d 6 is the C-terminal part of VTG-1 and was found to be allergenic in significant percentage of egg white allergy patients. These results highlight the significance of Gal d 6 as an important allergen of egg yolk. Therefore, the secondary aim of this study involved developing a recombinant version of YGP42 in an Escherichia coli expression system. Recombinant Gal d 6 (rGal d6) was expressed as a fusion peptide with a 6 × His tag and purified using metal chelating resin. The inhibition ELISA results showed that rYGP42 was IgE reactive and was able to inhibit IgE binding to crude egg yolk (CEY) by up to 30%. Traditionally, it was thought that allergy to egg yolk occurred independently from sensitization to egg white. This study underlies the importance of concomitant sensitization to egg yolk proteins in patients allergic to egg white. Evidence reported in this study strongly suggests that egg yolk has potentially undiscovered allergens and therefore warrants further investigation. Furthermore, IgE reactive Gal d 6 presented in this study has the potential to be used in diagnosis and immunotherapy to treat egg allergy.     

IgY治疗烧伤后肠源性白色念珠菌感染的实验研究

目的　为治疗严重烧伤后肠源性白色念珠菌感染寻求新的治疗措施。方法　选用标准白色念珠菌菌株免疫纯系Leghorn鸡 ;采用改良水溶法 (WD)从蛋黄中提取抗体IgY ,双紫外光测定抗体含量 ,通过SDS PAGE电泳检测抗体纯度 ,Wes tern blotting免疫印迹法测定该抗体来源 ,ELISA法检测热处理后IgY的活性 ,采用纯系SPF小鼠烧伤 (2 5 %Ⅲ度烧伤面积 )肠源性白色念珠菌感染的模型 ,特异IgY治疗并与对照组比较。结果　IgY的效价高 (1∶12 80 0 )、特异性强和理化性质稳定 ;喂服IgY治疗烧伤小鼠后 ,明显抑制小鼠肠道内白色念珠菌的黏附、生长 ;明显降低了烧伤小鼠血浆中二胺氧化酶 (DAO)和肿瘤坏死因子 (TNF α)的释放 ,维护肠黏膜上皮的完整 ,减轻了白色念珠菌对小肠上皮细胞的损害 ;促进肠淋巴细胞分泌IgA ;恢复肠道局部免疫功能。结论　特异IgY效价高、特异性强、理化性质稳定 ,治疗烧伤小鼠肠源性白色念珠菌感染疗效显著