Search Results

You are looking at 1 - 5 of 5 items for

  • Author or Editor: Anne M. Barger x
  • Refine by Access: All Content x
Clear All Modify Search
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine concentrations of receptor activator of nuclear factor-κB ligand (RANKL) and osteoprotegerin (OPG) in equine chondrocytes and synoviocytes and to quantify changes in the OPG:RANKL ratio in response to exogenous factors.

Sample Population—Samples of articular cartilage and synovium with grossly normal appearance obtained from metacarpophalangeal and metatarsophalangeal joints of 5 adult (1- to 8-year-old) horses.

Procedures—Cell cultures of chondrocytes and synoviocytes were incubated with human recombinant interleukin-1B (hrIL-1β; 10 ng/mL), lipopolysaccharide (LPS; 10 μg/mL), or dexamethasone (100nM) for 48 hours. Negative control cultures received no treatment. Cells and spent media were assayed for RANKL and OPG concentrations by use of western blot and immunocytochemical analyses. Spent media were also assayed for OPG concentration by use of an ELISA.

Results—RANKL and OPG were expressed in equine chondrocytes and synoviocytes in vitro. Cell-associated RANKL and OPG concentrations were not impacted by exogenous factors. Soluble RANKL release into media was significantly increased by hrIL-1β in chondrocyte but not in synoviocyte cultures. Soluble OPG release into media was significantly increased by hrIL-1β and LPS in chondrocyte but not in synoviocyte cultures. The soluble OPG:RANKL ratio was significantly increased by LPS in chondrocyte cultures. Dexamethasone decreased OPG expression in synoviocytes.

Conclusions and Clinical Relevance—RANKL and OPG proteins were expressed in equine articular cells. Release of these proteins may affect osteoclastogenesis within adjacent subchondral bone. Thus, RANKL and OPG may have use as biomarkers and treatment targets in horses with joint disease.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate a commercially available modified-live Streptococcus equi subsp equi vaccine for safety and persistence in vaccinated ponies and to detect recombination or reversion events in the vaccine strain.

Animals—5 ponies that were 1.5 to 8 years old (group 1) and 4 ponies that were 6 months old (group 2).

Procedures—Ponies were vaccinated, with a subsequent booster vaccination 2 to 3 weeks later, and monitored for 50 days. At booster vaccination, an equal amount of a tetracycline-resistant wild-type strain of S equiwas administered. Recovery of all strains was performed by use of bacteriologic culture and PCR assays.

Results—Ponies in group 1 had background antibody titers against S equi antigen before vaccination despite the lack of known exposure to S equi. Ponies in group 2 were immunologically naïve. Increases in anti-S equi antibody titers were detected in both groups. Ponies in group 1 did not have clinical signs of disease caused by S equi. In group 2, all ponies developed abscesses in retropharyngeal lymph nodes; 1 pony developed severe clinical disease and was euthanized. The vaccine strain was recovered from ponies in group 2 for up to 24 days after vaccination.

Conclusions and Clinical Significance—Although the vaccine was successful in inducing IgG antibodies against S equi in all ponies, findings suggested that the vaccine may have caused substantial morbidity and some deaths in the young ponies. In young ponies, the vaccine strain persisted in tissues for weeks; however, no evidence of recombination was detected.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine the effect of continuous IV administration of 50% dextrose solution on phosphorus homeostasis in lactating dairy cows.

Design—Clinical trial.

Animals—4 multiparous Jersey cows.

Procedures—Cows were administered 50% dextrose solution IV (0.3 g/kg/h [0.14 g/lb/h]) for 5 days. Plasma concentrations of glucose, immune-reactive insulin (IRI), and phosphorus were determined before, during, and for 72 hours after dextrose infusion. Phosphorus intake and losses of phosphorus in urine, feces, and milk were determined. Each cow received a sham treatment that included instrumentation and sampling but not administration of dextrose.

Results—Plasma glucose, IRI, and phosphorus concentrations were stable during sham treatment. Plasma phosphorus concentration decreased rapidly after onset of dextrose infusion, reaching a nadir in 24 hours and remaining less than baseline value for 36 hours. Plasma phosphorus concentration increased after dextrose infusion was stopped, peaking in 6 hours. Urinary phosphorus excretion did not change during dextrose infusion, but phosphorus intake decreased because of reduced feed intake, followed by decreased fecal phosphorus loss and milk yield. Rapid changes in plasma phosphorus concentration at the start and end of dextrose infusion were temporally associated with changes in plasma glucose and IRI concentrations and most likely caused by compartmental shifts of phosphorus.

Conclusions and Clinical Relevance—Hypophosphatemia developed in response to hyperglycemia or hyperinsulinemia in dairy cows administered dextrose via continuous IV infusion. Veterinarians should monitor plasma phosphorus concentration when administering dextrose in this manner, particularly in cows with decreased appetite or preexisting hypophosphatemia.

Restricted access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate clinical and laboratory findings, treatment, and clinical outcome in cats with blastomycosis.

Design—Retrospective case series.

Animals—8 cats with naturally occurring blastomycosis.

Procedures—Medical records of the University of Illinois Veterinary Teaching Hospital were searched for cases of blastomycosis in cats diagnosed via cytologic or histopathologic findings. Clinical and laboratory findings, treatment, and clinical outcome were determined. Radiographs were reviewed for the 8 cases.

Results—All cats were systemically ill. Respiratory tract signs and dermal lesions were most commonly observed. All cats had radiographic evidence of respiratory tract disease. Seven of the 8 cats had ill-defined soft-tissue opacities (nodules or masses) or alveolar consolidation of the lungs. Antemortem diagnosis was achieved cytologically in 6 of the 8 cats, and 3 were successfully treated and survived.

Conclusions and Clinical Relevance—In contrast to previous reports, diagnosis was achieved antemortem in most of the cats (all by cytologic identification of the organism). Clinical signs, laboratory findings, and outcome were similar to previous descriptions of this rare disease in cats.

Restricted access
in Journal of the American Veterinary Medical Association