摘要:

Recombinant bovine interleukin‐2 was evaluated as a potential immunoenhancer of bovine mammary gland mononuclear cells. Bovine mononuclear cells were isolated from five primiparous Holstein cows at 14–18 and 28–32 days of involution and at 7–13 days prior to parturition. Optimal stimulatory concentrations of the T‐lymphocyte mitogen concanavalin A and the T‐dependent B‐lymphocyte mitogen pokeweed mitogen were determined to be 6.25 and 2 μg ml‐1respectively. Proliferation of mononuclear cells in response to recombinant bovine interleukin‐2 was evaluated in the presence of suboptimal concentrations of concanavalin A and pokeweed mitogen to avoid masking potential effects of recombinant IL‐2. Bovine blood and mammary gland mononuclear cells were highly responsive to mitogens and to recombinant bovine interleukin‐2. The response of mammary gland mononuclear cells to recombinant bovine interleukin‐2 was comparable with the response of blood mononuclear cells. The data suggest that recombinant bovine interleukin‐2 may be an effective in vivo immunoenhancer of mammary gland mononuclear cells.

ISSN:0954-0105    

DOI:10.1080/09540109209354747

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

An indirect enzyme‐linked immunosorbent assay (ELISA) has been developed for the specific detection of cow's milk (1–25%) in goat's milk. The test uses polyclonal antibodies raised in rabbits against bovine whey proteins (BWP). The anti‐BWP antibodies were recovered from the crude antiserum by immunoadsorption and elution from a column containing immobilized BWP. The anti‐BWP antibodies were biotinylated and rendered cow's milk specific by mixing them with lyophilized ovine and caprine whey proteins. Streptavidin‐peroxidase was used to detect the biotinylated anti‐BWP antibodies bound to bovine milk proteins immobilized on 96‐well plates. The colour developed by the subsequent enzymic conversion of the substrate gave clear absorbance differences when assaying mixtures of goat's milk containing variable amounts of cow's milk.

ISSN:0954-0105    

DOI:10.1080/09540109209354748

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The mould latex agglutination test for the determination of immunogenic extracellular polysaccharides (EPS) produced by moulds was compared with the measurement of ergosterol in foods and feedstuffs with respect to sensitivity and applicability to detection of mould contamination. Both assays were able to detect Penicillium aurantiogriseum and Aspergillus niger at the same stage of growth in liquid and on solid substrates. During incubation, ergosterol and EPS content increased parallel to mould colony count and mycelial dry weight. Growth of Fusaria was detected by the ergosterol assay earlier than by the latex agglutination test. Applicability of the two assays was proved by testing 26 naturally contaminated foods and feedstuffs. From all samples positive results with agglutination titres ranging from 100 to 100 000 and ergosterol contents ranging from 0.6 to 56 mg kg‐1were obtained.

ISSN:0954-0105    

DOI:10.1080/09540109209354749

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Monoclonal antibodies (MAbs) were produced toRhizomonas suberifaciensstrain CA1. Initial screening of MAbs was performed with strains CA1 and FL1 ofR. suberifaciensand 82 strains of other genera in antibody capture indirect enzyme‐linked immunosorbent assay (ELISA) tests. One MAb (MAb‐Rs 1) reacted with both strains ofR. suberifaciensand another (MAb‐Rs 2) only withR. suberifaciensstrain CA1. Both MAbs were further screened for cross‐reactivity with 28 strains of R.suberifaciens,four strains ofRhizomonassp., and 56 strains of unknown bacteria isolated from lettuce, prickly sowthistle and melon roots with symptoms of corky root. All these strains were tested for pathogenicity on lettuce, DNA homology with DNA ofR. suberifaciensstrain CA1, and cross‐reactivity with both MAbs in indirect antibody capture and indirect double antibody sandwich (DAS) ELISA tests. All strains ofR. suberifaciensreacted with MAb‐Rs1 in both indirect ELISA tests, while none of the other strains reacted. In antibody capture indirect ELISA tests, MAb‐Rs2 had affinity to strains ofR. suberifaciensfrom California and New York but not to those from Florida, Wisconsin and one from New York. In indirect DAS ELISA tests, MAb‐Rs2 reacted with all strains of R.suberifaciens.The indirect DAS ELISA tests were more sensitive than the indirect antibody capture tests.

ISSN:0954-0105    

DOI:10.1080/09540109209354750

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The effects of feeding cow milk casein (100 mg per day) on allergic responses in mice were studied by observing3H‐thymidine incorporation in lymphocytes and histamine release from peritoneal mastocytes. Lymphocytes cultured in the presence of casein showed proliferative activities as early as two weeks feeding up to the eighth week. This activity was not in agreement with either the positive cutaneous test or the antigenic histamine liberation. The total histamine contents in the mastocytes were found to increase from 3.2±1.9 nmol per 105cells for the control group to 7.1 ±3.2; 6.2 ± 1.3; 6.7 ± 1.6 after four, six and eight weeks of feeding, respectively. These findings leads us to postulate that there were lymphocyte activations and mastocyte histamine accumulations as the results of intestinal permeability to casein‐derived molecules.

ISSN:0954-0105    

DOI:10.1080/09540109209354751

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

First generations of milk protein exempted mice (6–8 weeks old) were fed with casein at 100 mg per day. At 0, 2, 4, 6, 8, 12 and 20 weeks of feeding, a group of eight mice was sacrificed to recover spleen lymphocytes and intraperitoneal mastocytes. In vitro lymphocyte3H‐thymidine incorporation in the presence of intact casein, peptic or peptic‐tryptic‐chymotryptic hydrolysate was significantly higher at eight and 12 weeks of feeding (p<0.05). The number of the sensitized mice increased from 39% in the control group to 61% in the experimental groups. The three antigens possessed a statistically equal capacity to stimulate lymphocyte proliferation. Measurements of plasma and culture supernatant IgG antibody production exhibited an elevated enzyme‐linked immunosorbent assay value starting from the eight week of casein feeding. Casein feeding also provoked histamine accumulation in the mastocytes which occured significantly after four weeks of feeding (p<0.001). The fact that the lymphocytes recognized not only intact casein but also its digestive enzyme hydrolyzates indicate that intestinal digestion and absorption processes could neither totally block the antigen passage nor destroy their epitopes.

ISSN:0954-0105    

DOI:10.1080/09540109209354752

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0954-0105    

DOI:10.1080/09540109209354746

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor