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Abstract

Objective—To develop a reliable ELISA by use of a unique antigen preparation for serum IgG quantification after vaccination against Campylobacter fetus in cattle.

Animals—Twenty-six 24-month-old virgin Hereford heifers and a naturally infected Hereford bull.

Procedures—5 antigens were prepared from a cell suspension of C fetus. Antigen preparations were the same as those reported in the literature, with the exception of antigens that were obtained by detergent solubilization of a C fetus cell suspension. For each antigen preparation, the optimal ELISA conditions for its immobilization were determined. Biotinylated antibodies against bovine immunoglobulins were obtained and used in the ELISA. Two groups of heifers were inoculated with commercial vaccines according to manufacturers' instructions. A control group was included. The immune response of vaccinated heifers and controls was followed for 6 months.

Results—Detergent solubilized C fetus antigens resulted in better ELISA performance than other antigen preparations. Antigens were optimally immobilized at neutral pH and low ionic strength. All antigen preparations saturated the well with the same amount of protein. The vaccination schedule that advised a booster resulted in higher antibody titers, which were sustained over a longer period than the other schedule.

Conclusions and Clinical Relevance—In the vaccination of cattle against C fetus, the ELISA we have developed may be used to evaluate serum antibody concentrations in response to various vaccines and vaccination schedules. Our results indicate that it is advisable to include a booster in the immunization protocol. (Am J Vet Res 2002;63:586–590)

Abstract

OBJECTIVE To assess the ability to regenerate an equine meniscus by use of a collagen repair patch (scaffold) seeded with mesenchymal stem cells (MSCs) derived from bone marrow (BM) or adipose tissue (AT).

SAMPLE 6 female Hispano-Breton horses between 4 and 7 years of age; MSCs from BM and AT were obtained for the in vitro experiment, and the horses were subsequently used for the in vivo experiment.

PROCEDURES Similarities and differences between MSCs derived from BM or AT were investigated in vitro by use of cell culture. In vivo assessment involved use of a meniscus defect and implantation on a scaffold. Horses were allocated into 2 groups. In one group, defects in the medial meniscus were treated with MSCs derived from BM, whereas in the other group, defects were treated with MSCs derived from AT. Defects were created in the contralateral stifle joint but were not treated (control samples).

RESULTS Both types of MSCs had universal stem cell characteristics. For in vivo testing, at 12 months after treatment, treated defects were regenerated with fibrocartilaginous tissue, whereas untreated defects were partially repaired or not repaired.

CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that MSCs derived from AT could be a good alternative to MSCs derived from BM for use in regenerative treatments. Results also were promising for a stem cell-based implant for use in regeneration in meniscal lesions.

IMPACT FOR HUMAN MEDICINE Because of similarities in joint disease between horses and humans, these results could have applications in humans.