人源抗乙型肝炎病毒表面抗原基因工程IgG全抗体的表达、纯化及初步鉴定

目的对人源抗乙型肝炎病毒表面抗原的基因工程IgG全抗体进行表达、纯化及初步鉴定。方法用含Fc片段抗-HBsAg Fab抗体基因的载体pAC-HBs-Fc,与杆状病毒线性DNA共转染昆虫细胞sf9,产生重组抗-HBsAg的全抗体。以不同浓度的HBsAg包被酶标板孔,用间接ELISA法检测培养上清中抗体的表达及特异性;用蛋白G亲和层析柱进行抗体的纯化,并对纯化的抗体进行SDS-PAGE、Western blot和竞争性ELISA分析。结果上清中表达的重组IgG抗体仅与HBsAg呈阳性反应,特异性良好,纯化后其纯度达97.1%。经SDS-PAGE和Western blot分析可见,IgG抗体轻链和重链的相对分子质量分别约为27000和55000,为人源IgG抗体。CHO表达的HBsAg和血源性HBsAg能竞争性抑制该重组IgG抗体与E.coli表达的HBsAg反应,其抑制率分别为55.9%和81.9%。结论人源抗乙型肝炎病毒表面抗原的基因工程IgG全抗体可在杆状病毒载体表达系统中成功表达。     

Effects of a low- or high-frequency colostrum feeding protocol on immunoglobulin G absorption in newborn calves

Calves might experience an upper limit of IgG absorption from colostrum ingestion at birth, but it is not clear whether the total IgG mass fed in the first meal or feeding frequencies can saturate the IgG transport mechanism and therefore limit IgG absorption. The objective of this study was to determine whether different colostrum replacer (CR) feeding frequencies affect serum IgG levels or apparent efficiency of absorption (AEA) in neonatal calves. Male Holstein calves (n = 40) were separated from their dams immediately after parturition and randomly assigned to receive CR [12% of birth body weight (BW)], following either (1) a low-frequency (LF; n = 20) or (2) a high-frequency (HF; n = 20) feeding protocol. Low-frequency calves received 2 CR meals (8% and 4% birth BW within 1 h after birth and 12 h after first CR feeding, respectively), whereas HF calves received 3 CR meals (4% of BW for each meal; within 1 h after birth, 6, and 12 h after first CR feeding). The CR powder fed had a dry matter IgG concentration of 30% and an IgG concentration of 70.5 g/L when reconstituted. All CR was fed via esophageal tube within 1 h after birth. Calves were bottle-fed pasteurized milk (5% birth BW) at 24, 36, and 48 h after the first CR feeding. Blood was collected before first CR feeding and at the following intervals post-CR feeding: every 2 h until 18 h; every 3 h from 18 to 30 h; and every 6 h from 30 to 48 h after the first CR feeding. Serum IgG values at 24 h did not differ between LF and HF (25.79 ± 0.93 and 25.66 ± 0.88 g/L, respectively). In the first meal, calves fed LF ingested a higher total IgG mass than HF (257.98 ± 4.16 g and 126.72 ± 4.05 g, respectively); however, AEA at 24 h did not differ for calves fed HF or LF (27.68 ± 1.16% and 27.63 ± 1.26%, respectively). The IgG area under the curve (AUC) at 24 h was greater for calves fed LF than HF (443.13 ± 15.17 and 379.59 ± 13.99 g of IgG/L × h, respectively). Additionally, AUC at 6 h, 12 h, and 48 h were greater for calves fed LF than HF. These results indicate that, although LF calves had a greater AUC, HF calves were still able to absorb IgG in the second and third meal, allowing HF calves to achieve serum IgG levels similar to those of LF calves at 24 h. In addition, the provision of 3 meals at 70.5 g/L of IgG within the first 12 h of life did not result in added benefits to serum IgG or AEA levels.     

36例IgG4相关硬化性胆管炎临床特点

目的　探讨IgG4相关硬化性胆管炎（IgG4-related sclerosing cholangitis，IgG4-SC）的临床特点。方法　2004年1月至2012年12月在北京协和医院住院治疗的IgG4-SC患者共36例，均符合2012年日本学者提出的IgG4-SC临床诊断标准的确诊要求。回顾性分析其临床资料，包括症状、实验室检查、影像学检查、病理结果和随访情况。结果　36例患者性别比（女/男）为0.24:1，平均发病年龄为（62.8±9.2）岁。最常见的临床症状为黄疸（77.8%，28/36）和腹痛（50.0%，18/36）。8例(22.2%)患者的胆红素水平在正常范围，其中3例谷氨酰转肽酶水平在正常范围。超声内镜发现34例（94.4%）患者胆管增厚，其检出率明显高于腹部超声（8.3%，3/36）和腹部CT（33.3%，12/36）（P＜0.05）。7例患者行胆管刷检或胆管活检，病理结果均为阳性。随访超过2年的23例患者，复发率为39.1%（9/23)，胆管外受累器官越多或受累胆管节段越多者，越容易复发。结论　IgG4-SC多见于中老年男性，符合慢性胆管炎的临床特点。少数患者临床没有任何胆管梗阻的征象。诊断IgG4-SC时，胆管病理的阳性率并不理想，影像学上非狭窄段的胆管壁均匀增厚对诊断十分有意义，超声内镜应作为疑诊IgG4-SC患者的常规检查项目。对IgG4-SC患者应密切随访，警惕复发及并存的恶性肿瘤。     

免疫透射比浊法测定初乳制品中IgG的质量浓度

应用免疫透射比浊法测定牛初乳中IgG的质量浓度,质量浓度在0.07～0.75g/L范围内线性关系良好。该方法准确性好,回收率较高,与火箭免疫电泳法比较,测定结果差异不显著,这说明该方法具有良好的可靠性。     

粉尘螨脂质体制备和对致敏小鼠免疫功能的影响

目的:制备粉尘螨脂质体, 并探讨其对粉尘螨(抗原) 致敏小鼠免疫功能的影响, 以了解粉尘螨脂质体脱敏效果及机制。方法:用粉尘螨(抗原) 致敏BALB/c 小鼠, 皮下注射不同剂量粉尘螨脂质体,ELISA 法分别检测小鼠血清总IgG、总IgE、螨特异性IgG (sIgG)、螨特异性IgE (sIgE) 滴度及IL-4、IFN-γ水平。结果:致敏组小鼠血清总IgE、sIgE、总IgG、sIgG 滴度及IL-4 水平较正常组升高(P<0.01), IFN-γ水平显著下降(P<0.01)。皮下注射粉尘螨脂质体后, 小(1 μg°g^-1 体重)、中(3 μg°g^-1 体重)、大(9 μg°g^-1体重) 剂量组小鼠血清IL-4 水平较致敏组下降, IFN-γ水平显著升高, 与正常组相近(P>.05)。总IgE、sIgE 均显著下降, 并以小剂量组下降最明显, 与正常组相近, 但中、大剂量组仍未下降至正常水平;小、中剂量组IgG 及sIgG 滴度与致敏组相比显著升高, 尤以小剂量组升高最明显, 而大剂量组与致敏组相比无明显差异, 但仍较正常组显著升高。结论:所制备的粉尘螨脂质体可以对粉尘螨致敏小鼠产生脱敏作用, 其中以小剂量组脱敏效果最好。     

Sera from Patients with NMOSD Reduce the Differentiation Capacity of Precursor Cells in the Central Nervous System

Introduction: AQP4 (aquaporin-4)–immunoglobulin G (IgG)-mediated neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory demyelinating disease that affects the central nervous system, particularly the spinal cord and optic nerve; remyelination capacity in neuromyelitis optica is yet to be determined, as is the role of AQP4–IgG in cell differentiation. Material and Methods: We included three groups—a group of patients with AQP4–IgG-positive neuromyelitis optica, a healthy group, and a sham group. We analyzed differentiation capacity in cultures of neurospheres from the subventricular zone of mice by adding serum at two different times: early and advanced stages of differentiation. We also analyzed differentiation into different cell lines. Results and Conclusions: The effect of sera from patients with NMOSD on precursor cells differs according to the degree of differentiation, and probably affects oligodendrocyte progenitor cells from NG2 cells to a lesser extent than cells from the subventricular zone; however, the resulting oligodendrocytes may be compromised in terms of maturation and possibly limited in their ability to generate myelin. Furthermore, these cells decrease in number with age. It is very unlikely that the use of drugs favoring the migration and differentiation of oligodendrocyte progenitor cells in multiple sclerosis would be effective in the context of neuromyelitis optica, but cell therapy with oligodendrocyte progenitor cells seems to be a potential alternative.     

高灵敏度AlGaN/GaN HEMT生物传感器设计及制作

目前AlGaN/GaN高电子迁移率晶体管(HEMT)生物传感器表面修饰及分子识别元件固定需在金属或氧化物门电极上进行,针对金属或氧化物门电极的存在增加了器件的制作难度,提高了制作成本,同时还影响了传感器灵敏度的提高等问题,提出了进行"生物分子膜"门电极的研究。传感器的表面采用3-氨基丙基三乙氧基硅烷(APTES)进行修饰作为分子识别元件固定的基底,该方法在降低传感器的制作成本的同时,提高了传感器的灵敏度,传感区域为长度L=5μm、宽度W=160μm的传感器测量质量浓度为0.1ng/mL的山羊免疫球蛋白(IgG)时,传感器源漏间电流呈现约30μA的电流降。该传感器反应速度快,适用于实时监测,在环境监控、医疗等领域有着良好的应用前景。     

牛初乳理化性质动态变化的研究

测定10头荷斯坦奶牛在泌乳0～44 h内的牛初乳理化性质,结果显示:随着泌乳时间的延长,牛初乳的相对密度、酸度、pH值、黏度、灰分质量分数、蛋白质质量分数及IgG质量分数呈下降趋势;乳糖质量分数呈上升趋势.实验测得牛初乳理化性质的变化趋势在泌乳24 h时变化较大.     

羊初乳免疫球蛋白(IgG)稳定性的研究

研究了酸、碱、糖、加热对羊初乳中免疫球蛋白（IgG）稳定性的影响.结果表明,IgG在pH值为5.0～10.0范围内比较稳定,在pH值为低于5.0条件下,随pH值降低,变性率剧烈上升;在加热或pH2.0的环境下,糖醇化合物对IgG具有保护作用,随着糖类浓度的升高IgG的变性率降低,其中蔗糖、果糖、麦芽糖的效果较好,葡萄糖、乳糖的效果较差;羊初乳中IgG对加热比较敏感,随着加热温度的上升,其变性率增大.于55℃加热30 min,变性率为25.5%;于65℃加热30 min,变性率为38.1%;于75℃加热7 min时,变性率已达100%;于85℃加热2.0 min时变性率也已达100%.