Production and characterization of antibodies cross-reactive with major aflatoxins

Antibodies cross-reactive with 4 major aflatoxins were demonstrated three weeks after immunization of rabbits with an immunogen which was prepared by conjugating aflatoxin B3 to bovine serum albumin. Aflatoxin B3 was first converted to its hemisuccinate before conjugation to the protein. Tritiated aflatoxin B1 (AFB1) was used as the marker ligand both for antibody titer determination as well as for analysis of antibody specificity. Competitive RIA revealed that the antibodies have good cross-reactivity with aflatoxins B1, B2, G1, and G2 when tritiated AFB1 was used as the marker ligand. The concentrations causing 50% inhibition of binding of 3H-AFB1 to the antibodies by unlabeled aflatoxins B1, B2, G1, G2 and B3 were found to be 0.25, 3.34, 0.32, 4.0 and 0.53 ng/assay, respectively. The antibodies could be used for simultaneous analysis of aflatoxins B1 and G1, two of the most important toxic metabolites produced by Aspergillus flavus and A. parasiticus.     

9,10-Dihydroergotamine: Production of antibodies and radioimmunoassay

Summary Antibodies against 9,10-dihydroergotamine (DHE) were produced by immunizing rabbits with a conjugate of 6-nor-6-carboxymethyl-9,10-dihydroergotamine and bovine serum albumin. A highly specific and sensitive radioimmunoassay for DHE has been developed.We are greatly indebted to Dr.T. Fehr for the synthesis of 6-nor-6-carboxymethyl-9,10-dihydroergotamine, and to Dr.E. Schreier for providing us with 9,10-dihydroergotamine-[13-³H]-base of high specific activity.     

Production and characterization of antibody against aflatoxin M1

Summary Antibody against aflatoxin M₁ was obtained after immunization of rabbits with bovine serum albumin-afla M₁ oxime conjugate. The antibody has greatest binding efficiency for afla M₁, and was less efficient for afla B₁. Cross-reaction of antibody with aflatoxin Q₁, aflatoxicol, and aflatoxin B_2a was weak. Aflatoxin B₂, G₁, and G₂ and afla B₁-guanine adduct showed almost no cross-reaction with the antibody. The sensitivity of the binding assay for aflatoxin M₁ detection is in the range of 1–10 ng per assay. Detailed methods for the preparation of the conjugate, production of immune serum, and methods for antibody determination are described.Supported by the College of Agricultural and Life Sciences, North Central Regional project NC-129, the University of Wisconsin-Madison, and by Public Health Service research grant number CA 15064 from the National Cancer Institute, NIH.The authors wish to thank Dr R.C. Garner for providing aflatoxin-B-guanine adduct, and Dr Dennis H. Hseih for providing aflatoxicol and aflatoxin Q₁.     

Production and characterization of antibody against aflatoxin M1

Antibody against aflatoxin M1 was obtained after immunization of rabbits with bovine serum albumin-afla M1 oxime conjugate. The antibody has greatest binding efficiency for afla M1, and was less efficient for afla B1. Cross-reaction of antibody with aflatoxin Q1, aflatoxicol, and aflatoxin B2a was weak. Aflatoxin B2, G1, and G2 and afla B1-guanine adducts showed almost no cross-reaction with the antibody. The sensitivity of the binding assay for aflatoxin M1 detection is in the range of 1-10 ng per assay. Detailed methods for the preparation of the conjugate, production of immune serum, and methods for antibody determination are described.     

Production of porcine antibodies with high specificity to [8-D-arginine] deamino-vasopressin (dDAVP)

Summary The development of a specific radioimmunoassay for [8-D-arginine] deamino-vasopressin (dDAVP) is described.Acknowledgment. We wish to express our thanks to Drs I. Bláha, M. Zaoral, M. Flegel and K. Jot for generous gift of hormones and their analogues used in this study.     

Production of active and passive anaphylactic shock in the WBB6F1 mouse,a mast cell-deficient strain

Summary The role of mast cells in active and passive anaphylactic shock was examined using the WBB6F₁ mouse, a genetically mast cell-deficient strain. Lethal anaphylactic shock occurred at high incidence rates in mice actively sensitized to bovine serum albumin (BSA). The reaction was specific to BSA since the shock could not be elicited by human or guinea pig serum albumin in these animals. Lethal shock could be prevented by CV-3988 but not by cyproheptadine, which suggests that the shock is mediated by PAF but not by histamine and serotonin. Similarly, lethal shock was provoked by homologous antigens in mice which had been passively sensitized with allogeneic anti-benzylpenicilloyl (BPO) IgG₁ monoclonal antibody or with allogeneic or xenogeneic anti-BSA antiserum, but not in those sensitized with allogeneic anti-BPO IgE monoclonal antibody. These findings suggest that mast cells are not necessarily required for anaphylactic shock in the mouse.     

A new type of antiserum to thyrotropin-releasing hormone; detection of new TRH-immunoreactive cell groups in rat hypothalamus

Summary We produced a new type of antiserum to thyrotropin-releasing hormone (TRH) in rabbits. The immunogen is TRH-BSA, the production of which is based on the formation of an amide bond using carbodiimide (EDC). The specificity of the antiserum was assessed by enzyme immunoassay (EIA) and immunohistochemistry. When using the anti-TRH serum for immunohistochemistry in rat hypothalamus, new magnocellular groups were detected in the ventrolateral parts of the posterior hypothalamus and the dorsal parts of the third ventricle. Colchicine treatment was found not to be necessary to visualize perikarya containing TRH.     

Production of passive cutaneous anaphylaxis (PCA) and reversed PCA by rat IgE antibody in the mouse

Summary Although IgE antibody is generally characterized as a homocytotropic antibody, it has been well known for some time that mouse IgE antibody causes potent sensitization of rat skin for PCA. The present study clearly shows, the reciprocal cross-sensitization of mouse skin with rat IgE molecules. PCA and RPCA were produced by rat IgE antibody in an inbred mouse strain, DS/Shi, though not in C3H/HeShi, C57BL/6JShi and BALB/cCrj strains. Sensitization of DS/Shi mouse skin for PCA with rat IgE antibody was comparable in sensitivity with that of rat skin, but lasted only for a short term in comparison with the long persistence in rat skin.     

Enzyme immunometric assay for the determination of pregnancy associated plasma protein A (PAPP-A) with the antigen as solid phase (conjoint IEMA)

Summary Purified pregnancy associated plasma protein A (PAPP-A) can be effectively bound to polystyrene microtitre plates. This immobilized antigen competes with the added serum PAPP-A of unknown concentration for the limited amount of peroxidase-labeled monospecific anti-PAPP-A antibody incubated simultaneously. The sensitivity is 0.2 WHO unit/ml and non-specific binding is 1.0%.Acknowledgments. My thanks go to the Janggen-Pöhn-Stiftung, St. Gallen, Switzerland, for the reception of a fellowship grant which enabled this work to be carried out. I would also like to thank Arnold Klopper, Professor of Reproductive Endocrinology, for many stimulating discussions, Garry Luke for excellent technical assistance, and the Department of Medical Illustration of the University of Aberdeen for the preparation of the graphics. The donkey serum was generously supplied by the Scottish Antibody Production Unit, Carluke, Lanarkshire.     

Interactions of anti-DNA antibodies with dinitrophenyl- and other hapten-protein-conjugates

Zusammenfassung Kreuzreaktionen mit Dinitrophenyl-, Pyrimidin-, Purin- sowie Nucleosid- und Nucleotid-Protein-Konjugaten konnten bei Antikörpern gegen DNS, wie sie im Serum von Patienten mit Lupus erythematodes auftreten, nachgewiesen werden. Diese Resultate sind möglicherweise von Bedeutung für die Interpretation der auffällig hohen Frequenz von Paraproteinen, welche mit Dinitrophenylverbindungen reagieren.

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Acknowledgments. The authors wish to thank MissE. Ischi for her excellent technical assistance, Dr.H. W. Baenkler (Erlangen) and Prof.P. H. Lambert (Geneva) for sera of patients with SLE.

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This investigation was supportec by the Swiss National Foundation for Scientific Research.     

Loss of antibody production accompanied by chromosome loss in a cloned hybrid line secreting antibodies to sheep red blood cells

Summary Somatic cell hybrids between Sp2/O-Ag14 mouse myeloma cells and lymphocytes derived from BALB/c mice hyperimmunized with sheep red blood cells (SRBC) were produced. One hybrid producing IgG₁ antibody to SRBC was selected, cloned twice and subsequently transferred to BALB/c mice. After a number of transfers it was found that the antibody titer in ascitec fluid gradually decreased. Cytogenetic analysis revealed gradual chromosome loss in the hybrid clone, which produced progressively less antibody.     

免疫诊断分析仪的全自动控制研究及实现

为了实现对免疫诊断分析仪的全自动控制,尽可能的降低操作者的劳动强度,提高检测结果的准确性和可靠性,设计了基于 Freescale单片机 MC9S12DG128的免疫诊断分析仪的全自动控制系统.重点研究了微型计算机控制技术,条形码读取系统,光电传感器检测系统,机械传动及定位系统等.通过合理的电路设计和软件编程,使分析仪高效可靠运行,实际测试表明分析仪实现了高自动化和良好的检测效果     

In vitro and in vivo interaction of nuclear antibodies with corresponding antigens

Zusammenfassung Es wird mit indirekter Immunofluoreszenz gezeigt, dass Leberzellkerne mit Antikörpern bedeckt werden können, wenn sie systemischemLupus erythromatosus-Serum (SLE) für weniger als 2 sec ausgesetzt werden, und dass die Färbungsintensität vom Titer des Antikörpers abhängt.Diese Ergebnisse deuten darauf hin, dass das in SLE-Geweben durch direkte Immunofluoreszenz nachgewiesene nukleare-Globulin hauptsächlich nukleare post-Biopsiereaktionen wiederspiegelt und weniger in vivo-Reaktionen, und dass in beiden Fällen nur abgestorbene oder nicht intakte Zellen vom Antikörper durchdrungen werden.

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This investigation was supported in part by a training grant (2E-130) from the U.S. Public Health Service. Taken in part from thesis (G.W.B.) submitted to the Faculty of the Graduate School of Arts and Sciences of the University of Buffalo (N.Y., USA) in partial fulfillment of the requirements for the degree of Doctor of Philosophy (1962). Present address (G.W.B.): Department of Pathology, State University of New York at Buffalo.