摘要:

Dothistromin (DOTH) is a fungal toxin occurring in Pinus radiata needles contaminated with Dothistroma pini. Monoclonal antibodies (MAbs) of high affinity were prepared against DOTH and incorporated into competitive ELISAs. MAbs were secreted by hybri‐doma prepared from mice immunized with DOTH conjugated, through the aromatic ring of the anthraquinone, to bovine serum albumin. DOTH could be quantitated at 2–60 ng ml‐1(0.1–2 ng/assay) and at 8–300 ng ml‐1(0.4–15 ng/assay) using peroxidase‐labelled MAb 10C12A5 and MAb 6A2D4 respectively in indirect competitive ELISA. The corresponding limits of detection of DOTH were < 300 pg and 1 ng ml‐1respectively. The furan ring was an important structure in the epitope recognized by both MAbs.

ISSN:0954-0105    

DOI:10.1080/09540109309354798

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Monoclonal antibodies reactive with deoxynivalenol were generated following the immunization of mice with a deoxynivalenol‐mouse serum albumin conjugate. One of the anti‐deoxynivalenol monoclonal antibodies, designated C6–1, exhibited cross‐reactivity with 3‐acetyldeoxynivalenol and 15‐acetyldeoxynivalenol but not with nivalenol, T‐2 tetraol or scirpentriol. An indirect competitive ELISA based on this monoclonal antibody gave 50% inhibition values of 0–6 μg ml‐1for deoxynivalenol, 0–2 μg ml‐1for 15‐acetyldeoxynivalenol and 10 μg ml‐1for 3‐acetyldeoxynivalenol.

ISSN:0954-0105    

DOI:10.1080/09540109309354799

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

In early weaned calves, rumen development resulting in elevated concentrations of blood β‐hydroxybutyrate (BHBA), or stress resulting in elevated concentrations of blood cortisol, may be deleterious to cell‐mediated immunity and overall calf health. To further define the influence of specific factors generated from these physiological events during early weaning of dairy calves on the immune response, this study evaluated the influence of increasing concentrations of BHBA (0.63–10 mM), 1,3‐butanediol (0.63–10 mg ml‐1) and cortisol (12.1–194 ng ml‐1) on responses of peripheral blood mononuclear cells (PBMCs; 5 calves, 11 weeks of age) to concanavalin A (Con A), phytohemagglutinin (PHA) and pokeweed mitogen (PWM) in vitro. Responses of PBMCs to PHA and PWM were unaffected by BHBA, while BHBA significantly reduced PBMC blastogenesis in response to Con A. However, in the presence of increasing BHBA, there was a slight but significant linear decline of PBMC blastogenesis in response to PHA. Cortisol significantly reduced PBMC blastogenesis in response to all mitogens, although inhibition did not increase above 24–3 ng ml‐1. Increasing concentrations of 1,3‐butanediol caused a significant linear reduction in PBMC blastogenesis in response to all mitogens. These results suggest that elevated BHBA concurrent with rumen development in dairy calves near weaning has little influence on mononuclear cell blastogenesis, whereas elevated cortisol concentrations may increase susceptibility of dairy calves to disease.

ISSN:0954-0105    

DOI:10.1080/09540109309354800

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The inhibitory effects of bovine milk κ‐casein and its enzymatic digests on the proliferative responses of mouse spleen lymphocytes induced or not induced by mitogens were studied with a colorimetric assay using 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide (MTT). κ‐Casein and its glyco‐macropeptide (residues 106–169) inhibited the lipopolysaccharide (LPS)‐induced proliferative response, but the inhibitory effect was lost significantly after neuraminidase and chymotrypsin digestions. In contrast, trypsin and pronase digestions of K‐casein increased inhibitory effects. The pronase digest inhibited the proliferative responses not only induced by LPS but also in the absence of mitogen or when induced by concanavalin A and phytohemagglutinin. The pronase digest seemed to possess weak cytotoxity for lymphocytes. The inhibitory peptide was a glycopeptide(s) having specific size, and the inhibitory effects were reduced significantly by neuraminidase and chymotrypsin digestions. Moreover, similar inhibitory effects on proliferation of lymphocytes were observed in pronase‐digested bovine milk αs1‐casein and β‐casein. These findings suggest that some peptides produced from milk caseins by the action of gastrointestinal proteinases might contribute to down‐regulate the immune response of neonates.

ISSN:0954-0105    

DOI:10.1080/09540109309354801

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Raw milk from non‐immunized cows and raw human milk from lactating mothers were examined for specificity and antibody activity against lipopolysaccharides (LPS) of five pathogenic bacteria, i.e. Escherichia coli O111:B4, E. coli O128:B12, Salmonella enteritidis, S. typhimurium and Shigella flexneri 1A in a particle concentration fluorescence immunoassay (PCFIA). Bacterial LPS was covalently coated on submicron polystyrene particles and used in an antibody sandwich technique with commercially available rabbit anti‐bovine fluorescein‐labeled IgG or goat anti‐human fluorescein‐labeled IgA. Comparison was made to a skim milk sample obtained from vaccinated cows. In general, specific activity of milk IgG against bacterial LPS did not parallel the trend of total non‐specific activity. Although the specific anti‐LPS activities were in general high in milk from vaccinated cows, milk from non‐immunized cows also showed significant activity against the bacterial LPS, sometimes higher than the vaccinated cows. IgA in human milk samples showed a wider range of antibody activity against the LPS fractions than bovine milk samples. The specificity of antibody from milk obtained from non‐immunized cows against pathogenic bacteria demonstrated that immunization of cows in order to obtain milk with high titer antibody may not be necessary as milk from non‐immunized cows can provide IgG with sufficient antibody activity against the LPS of bacterial pathogens. This can translate into significant savings and reduce stress imposed on animals for immunization.

ISSN:0954-0105    

DOI:10.1080/09540109309354802

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Monoclonal antibodies (IgM class) to Penicillium bilaii (isolate PB‐50) were developed and their specificity was determined against various fungi using enzyme‐linked immunosorbent assays. Cross‐reactivity in the range 0–6.5% was obtained for Fusarium, Aspergillus, Paecilomyces and Trichoderma species while 1.5–9.5% was obtained for P. lapidosum, P. crustosum, P. hiramayae, P. spinolosum and P. implicatum. Strains of P. bilaii (ATCC 22348 and ATCC 18309) yielded a relative cross‐reactivity of 15.9 and 10.8%, respectively. An immunochemical test for the detection of PB‐50 mycelia in plant and soil samples was devised using monoclonal antibodies. Several procedures have been proposed to show the feasibility of the application of developed monoclonal antibodies to P. bilaii PB‐50 detection in plant and soil samples. The immunodiffusion blotting method was superior to other tests for the detection of PB‐50 in infected plant samples.

ISSN:0954-0105    

DOI:10.1080/09540109309354803

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Basic Guide to Pesticides: Their Characteristics and Hazards

ISSN:0954-0105    

DOI:10.1080/09540109309354804

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

ISSN:0954-0105    

DOI:10.1080/09540109309354797

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor