多西环素人工抗原的合成与鉴定

建立多西环素人工抗原(Doxycycline,DOX)的合成及鉴定方法。采用戊二醛偶联法将DOX分别与载体牛血清白蛋白(BSA)及卵清蛋白(OVA)偶联制备免疫抗原(DOX-BSA)和包被抗原(DOX-OVA)。经SDS-PAGE电泳法、紫外可见吸收光谱鉴定,证实人工抗原成功合成,偶联比分别为8.6∶1和3.8∶1。结果表明建立了一种新的DOX抗原合成方法,为进一步制备特异性DOX抗体和建立检测食品中DOX的酶联免疫方法奠定了基础。     

西马特罗免疫抗原合成方法的比较

为探讨西马特罗(CIM)免疫抗原合成的有效途径,本研究采用重氮化法、碳化二亚胺法和BS3法分别合成CIM免疫抗原,并采用SDSPAGE和紫外光谱扫描对合成抗原进行了鉴定,并将3种免疫抗原免疫BALB/c小鼠,对免疫效果进行了比较。试验表明,3种方法均合成了CIM免疫抗原,经偶联比的计算,重氮化法的偶联比比较理想,且免疫小鼠后可获得高效价、高特异的抗体。     

雌二醇多克隆抗体的制备与鉴定

制备雌二醇完全抗原,并通过免疫家兔得到多克隆抗体,为下一步制备雌二醇单克隆抗体和雌二醇检测ELISA试剂盒奠定基础。试验以牛血清白蛋白(BSA)、卵清蛋白(OVA)为载体,采用碳化二亚胺法,合成了雌二醇(E2)的2种免疫偶合物:免疫原E2-BSA和包被原E2-OVA;通过紫外光谱定性证明偶合物偶联成功与否,并对偶合物的蛋白含量、结合比进行测定并以免疫原E2-BSA免疫家兔,制备多克隆抗体,用包被原E2-OVA进行ELISA,对多克隆抗体特异性及效价进行检测。结果表明成功合成了雌二醇人工抗原即免疫原E2-BSA和包被原E2-OVA,二者的蛋白浓度分别为5.455和7.533mg/mL,结合比分别为7:1和8:1;制备的多克隆抗体特异性好,血清效价为1:106。     

硝基呋喃类药物广谱特异性多克隆抗体的制备与鉴定

以5-硝基糠醛为分子模板合成了硝基呋喃类药物的共有半抗原,然后分别以重氮法和戊二醛法合成了人工完全抗原。以两种方法所得免疫原免疫新西兰兔,获得了能够同时识别8种硝基呋喃药物的广谱特异性抗体。两种抗体均对8种药物具有较高的灵敏度和交叉反应性。检测限范围为6~19 ng/mL,交叉反应率范围为32%~92%。因此,本研究制备的广谱特异性抗体可以用于研究建立多残留检测硝基呋喃类药物的免疫分析方法。     

氯霉素人工抗原的合成及其结合比的测定

以牛血清白蛋白(BSA)、人血清白蛋白(HSA)为载体，采用重氮化法，合成氯霉素(CAP)的2种免疫偶合物：免疫原CAP-BSA和包被抗原CAP-HSA；通过紫外光谱定性证明偶合物偶联成功与否。结果表明，此方法不仅简便快捷，灵敏度高；还简化了合成的过程，得到了结合比较好的人工抗原。     

β-受体激动剂类药物人工抗原合成方法研究进展

开展动物性食品中β-受体激动剂监测,对保障食品安全具有重要意义。免疫分析技术操作快速、灵敏度高、检测成本低,被广泛用于大批量畜禽产品的快速筛查。抗体特性是免疫检测的核心,而人工抗原合成的质量直接影响特异性抗体性能。本文主要综述了碳二亚胺法、活泼酯法、混合酸酐法、重氮化法、戊二醛法等β-受体激动剂类药物人工抗原合成方法,以及紫外光谱法、核磁共振法等人工抗原鉴定方法,以期为免疫分析等相关工作研究提供参考。     

环丙沙星人工抗原的合成及鉴定

为了合成环丙沙星抗原,试验应用3-溴丙氨氢溴酸盐制备半抗原环丙沙星-溴丙氨衍生物,采用戊二醛方法与碳二亚胺法合成环丙沙星免疫抗原(CIP-NH2-BSA)与环丙沙星包被抗原(CIP-NH2-OVA),其中环丙沙星-溴丙氨衍生物采用红外光谱(IR)、电喷雾电离质谱(ESI-MS)和核磁共振(1H-NMR、13C-NMR)进行结构确证,CIP-NH2-BSA与CIP-NH2-OVA采用紫外扫描法进行鉴定。结果表明:环丙沙星-溴丙氨衍生物合成成功,环丙沙星-溴丙氨衍生物与牛血清白蛋白(BSA)和卵清白蛋白(OVA)耦联成功。说明通过制备环丙沙星衍生物可以合成高效的抗原。     

抗磺胺二甲氧嘧啶VHH抗体噬菌体库的构建和鉴定

旨在制备抗磺胺二甲氧嘧啶(SDM)驼源单域重链(VHH)抗体,用于检测动物源性食品中SDM的残留。采用重氮化法,SDM分别与牛血清白蛋白(BSA)和鸡卵清蛋白(OVA)偶联,合成人工免疫原(SDM-BSA)和包被抗原(SDM-OVA)。用SDM-BSA免疫骆驼,在第5次免疫后1周采集骆驼外周血液,分离外周血淋巴细胞,提取RNA,RT-PCR扩增VHH基因,将VHH基因插入pCANTAB-5E噬菌粒载体,构建双峰驼单域重链抗体库。经本实验室前期测定其库容为1.08×10⁵ CFU,阳性率为96.6%。利用噬菌体展示技术经过4轮生物淘选,筛选获得特异性表达抗SDM抗体的重组噬菌体。结果:构建了SDM的驼源VHH抗体库,经生物淘选及phage ELISA检测获得了特异性的重组噬菌体。通过4轮生物淘选,获得了能够与SDM-OVA抗原有明显结合力且能够特异性表达抗SDM抗体的重组噬菌体,为后期检测SDM在动物源性食品残留奠定了良好的基础。     

一种快速的免疫分析法测定磺胺地索辛

利用热敏感性水凝胶作为磺胺地索辛(SDM)多克隆抗体载体,通过异硫氰基荧光素(FITC)标记SDM全抗原,建立一种快速的荧光免疫分析法测定SDM。实验结果表明,该法具有较高的灵敏度,对SDM测定的线性范围在1ng/mL￣100μg/mL,60%抑制率时检出限为0.114μg/mL。     

氟虫腈单克隆抗体的制备及其在牛乳检测中的应用

合成氟虫腈人工完全抗原,制备氟虫腈单克隆抗体,以氟虫腈及氟虫腈类似物为半抗原,分别采用戊二醛法和碳二亚胺法合成人工完全抗原;利用紫外光谱扫描法、十二烷基硫酸钠-聚丙烯酰胺凝胶电泳法进行鉴定;使用氟虫腈-牛血清蛋白人工完全抗原免疫BALB/c小鼠,得到杂交瘤细胞株,采用小鼠体内诱生腹水方法制备单克隆抗体;使用酶联免疫吸附测定法测定氟虫腈在牛乳中的加标回收率及精密度。结果表明：氟虫腈的人工完全抗原合成成功,制备的单克隆抗体3F6质量浓度为8.5 mg/mL,效价为2.0×106,亚型为IgG1,与氟甲腈、氟虫腈砜、氟虫腈亚砜的交叉反应率分别为9.21%、14.02%、21.46%;氟虫腈在牛乳中的加标回收率为87%～118%,变异系数低于15%,方法具有较高准确度和精密度。     

Distribution of ASFV antigens in pig tissues experimentally infected with two different Spanish virus isolates.

Lymph nodes, spleen, liver, lung and kidney obtained from pigs experimentally infected with two African Swine Fever Virus (ASFV) isolates of differing virulence were fixed by perfusion with glutaraldehyde and embedded in paraffin. An immunoperoxidase technique using a polyclonal anti-ASFV serum was performed on tissue sections in order to detect ASFV antigen. The distribution of ASFV antigen in such infected organs is shown and the differences between both infections compared and discussed. Monocytes, macrophages, hepatocytes, endothelial cells, neutrophils and epithelial cells were found to contain ASFV antigens.     

Sexing murine embryos with an indirect immunofluorescence assay using phage antibody B9-Fab against SDM antigen

The use of serologically detectable male (SDM; also called H-Y) antigens to identify male embryos may be limited by the source of anti-SDM antibody. In the present study, novel anti-SDM B9-Fab recombinant clones (obtained by chain shuffling of an A8 original clone) were used to detect SDM antigens on murine embryos. Murine morulae and blastocysts (n=138) were flushed from the oviducts of Kunming mice and incubated with anti-SDM B9-Fab for 30 min at 37°C. With an indirect immunofluorescence assay, the membrane and inner cell mass had bright green fluorescence (presumptive males). Overall, 43.5% (60/138) were classified as presumptive males and 56.5% (78/138) as presumptive females, with 85.0 and 88.5% of these, respectively, confirmed as correct predictions (based on PCR analysis of a male-specific [Sry] sequence). We concluded that the anti-SDM B9-Fab molecule had potential for non-invasive, technically simple immunological sexing of mammalian embryos.     

Detection of African swine fever viral antigens in paraffin-embedded tissues by use of immunohistologic methods and polyclonal antibodies.

Tissues obtained from pigs inoculated with African swine fever virus (ASFV), fixed by vascular perfusion using glutaraldehyde, and embedded in paraffin or araldite were used for an immunohistologic electron microscopic study. To detect ASFV antigens, 4 methods were used on paraffin sections with or without pretreatment of the tissues. Use of biotinylated anti-ASFV antiserum combined with avidin-biotin complex and peroxidase proved to be the most suitable method, and antigen was detected in tissues infected with 2 ASF viruses of different virulence. Use of the glutaraldehyde fixation method should ensure optimal morphologic (structural and ultrastructural) data while allowing an immunohistologic study, and add to knowledge of the pathogenesis of ASF.     

Dose dependent disposition of sulphadimidine and of its N4-acetyl and hydroxy metabolites in plasma and milk of dairy cows

The disposition of sulphadimidine (SDM) and of its N4-acetyl (N4-SDM) and two hydroxy metabolites, 6-hydroxymethyl-(SCH2OH) and 5-hydroxyasulphadimidine (SOH), was studied in plasma and milk of dairy cows following intramuscular or intravenous administration of sulphadimididine-33.3% at doses of 10, 45, 50, and 100 mg/kg. The main metabolite in plasma as well as in milk was SCH2OH. The metabolite percentages, the final plasma elimination half-lives, and the time of peak SDM concentrations in milk are presented for different dosages. The concentrations of SDM and its metabolites in milk ran parallel to those in plasma beyond 4 hours p.i. The metabolite concentrations in plasma and milk were lower than those of the parent SDM. Sulphate and glucuronide metabolites could not be detected in milk. At high doses (45 mg/kg or more) and SDM plasma concentrations exceeding 20 micrograms/ml, a capacity limited metabolism of SDM to SCH2OH was noticed, viz. a steady state concentration of SCH2OH and a biphasic elimination pattern for SDM and SCH2OH in plasma and milk. The mean ultrafiltrate ratios of the milk to plasma concentrations with respect to SDM, SCH2OH, SOH, and N4-SDM were: 0.69, 0.22, 020, and 0.63, respectively. The total amount of SDM and its metabolites recovered from the milk after milking twice daily over the whole experimental time was less than 2% of the applied dose. A bioassay method allowed of detecting qualitatively SDM concentrations exceeding 0.2 micrograms/ml in plasma or milk. Withholding times for edible tissues and milk are suggested.     

Pharmacokinetics, renal clearance, tissue distribution, and residue aspects of sulphadimidine and its N4-acetyl metabolite in pigs

Pharmacokinetics and tissue distribution experiments were conducted in pigs to which sulphadimidine (SDM) was administered intravenously, orally, and intramuscularly at a dosage of 20 mg SDM/kg. SDM was acetylated extensively, but neither hydroxy metabolites nor their derivatives could be detected in plasma, edible tissues or urine. Following i.v. and two oral routes of administration, the N4-acetylsulphadimidine (N4-SDM) concentration-time curve runs parallel to that of SDM. The percentage of N4-SDM in plasma was in the range between 7 and 13.5% of the total sulphonamide concentration. The bioavailability of SDM administered in a drench was 88.9 +/- 5.4% and administered mixed with pelleted feed for 3 consecutive days it was 48.0 +/- 11.5%. The renal clearance of unbound SDM, which was urine flow related, was 1/7 of that of creatinine, indicating reabsorption of the parent drug. The unbound N4-SDM was eliminated three times faster than creatinine, indicating that tubular secretion was the predominant mechanism of excretion. After i.v. administration, 51.9% of the administered dose was recovered in urine within 72 h p.i., one quarter of which as SDM and three quarters as N4-SDM. Tissue distribution data obtained at 26, 74, 168, and 218 h after i.m. injection revealed that the highest SDM concentration was found in plasma. The SDM concentration in muscle, liver, and kidney ranged from one third to one fifth of that in plasma. The N4-SDM formed a minor part of the sulphonamide content in edible tissues, in which the SDM as well as the N4-SDM concentration parallelled the plasma concentrations. Negative results obtained with a semi-quantitative bioassay method, based on monitoring of urine or plasma, revealed that the SDM concentration levels in edible tissues were in that case below 0.1 mu/g tissue.     

Pharmacokinetics of sulphadimidine in carp (Cyprinus carpio L.) and rainbow trout (Salmo gairdneri Richardson) acclimated at two different temperature levels

The influence of temperature (10 degrees C and 20 degrees C) on pharmacokinetics and metabolism of sulphadimidine (SDM) in carp and trout was studied. At 20 degrees C a significantly lower level of distribution (Vdarea) and a significantly shorter elimination half-life (T(1/2)beta) was achieved in both species compared to the 10 degrees C level. In carp the body clearance parameter (ClB(SDM)) was significantly higher at 20 degrees C compared to the value at 10 degrees C, whereas for trout this parameter was in the same order of magnitude for both temperatures. N4-acetylsulphadimidine (N4-SDM) was the main metabolite of SDM in both species at the two temperature levels. The relative N4-SDM plasma percentage in carp was significantly higher at 20 degrees C than at 10 degrees C, whereas there was in trout no significant difference. In neither species was the peak plasma concentration of N4-SDM (Cmax(N4-SDM)) significantly different at two temperatures. The corresponding peak time of this metabolite (Tmax(N4-SDM)) was significantly shorter at 20 degrees C compared to 10 degrees C in both carp and trout. In carp at both temperatures, acetylation occurs to a greater extent than hydroxylation. Only the 6-hydroxymethyl-metabolite (SCH2OH) was detected in carp, at a significant different level at the two temperatures. Concentrations of hydroxy metabolites in trout were at the detection level of the HPLC-method (0.02-micrograms/ml). The glucuronide metabolite (SOH-gluc.) was not detected in either species at the two temperatures.     

Pharmacokinetics,renal clearance,tissue distribution,and residue aspects of sulphadimidine and its N4‐acetyl metabolite in pigs

Summary

Pharmacokinetics and tissue distribution experiments were conducted in pigs to which sulphadimidine (SDM) was administered intravenously, orally, and intramuscularly at a dosage of 20 mg SDM/kg. SDM was acetylated extensively, but neither hydroxy metabolites nor their derivatives could be detected in plasma, edible tissues or urine. Following i.v. and two oral routes of administration, the N₄‐acetylsulphadimidine (N₄‐SDM) concentration‐time curve runs parallel to that of SDM. The percentage of N₄‐SDM in plasma was in the range between 7 and 13.5% of the total sulphonamide concentration. The bioavailability of SDM administered in a drench was 88.9 ± 5.4 % and administered mixed with pelleted feed for 3 consecutive days it was 48.0 ± 11.5 %. The renal clearance of unbound SDM, which was urine flow related, was 1/7 of that of creatinine, indicating reabsorption of the parent drug. The unbound N₄SDM was eliminated three times faster than creatinine, indicating that tubular secretion was the predominant mechanism of excretion.

After i.v. administration, 51.9 % of the administered dose was recovered in urine within 72 h p.i., one quarter of which as SDM and three quarters as N₄‐SDM.

Tissue distribution data obtained at 26, 74, 168, and 218 h after i.m. injection revealed that the highest SDM concentration was found in plasma. The SDM concentration in muscle, liver, and kidney ranged from one third to one fifth of that in plasma. The N₄‐SDM formed a minor part of the sulphonamide content in edible tissues, in which the SDM as well as the N₄‐SDM concentration parallelled the plasma concentrations.

Negative results obtained with a semi‐quantitative bioassay method, based on monitoring of urine or plasma, revealed that the SDM concentration levels in edible tissues were in that case below 0. 1μ/g tissue.