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in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE

To determine the following: (1) whether an irrigation solution that is hyperosmolar (HYPER) relative to synovial fluid decreases tissue extravasation during an arthroscopic protocol when compared to a relatively hypoosmolar solution, (2) the safety of a HYPER solution based on viability of joint tissues following joint irrigation, and (3) if the use of a HYPER solution decreases water content in stifle joint tissue.

ANIMALS

8 adult horses.

PROCEDURES

A prospective, blinded, randomized controlled trial was performed to compare lactated Ringer’s solution (LRS; 273 mOsm/L) and a HYPER (600 mOsm/L) irrigation solution for routine medial femorotibial joint (MFTJ) arthroscopy. Primary outcomes included quantification of periarticular fluid retention based on measured changes in defined stifle joint girth and ultrasonographic (US) criteria. Water content of tissue samples was assessed. The viability of articular cartilage was determined using a microscopic fluorescent cell viability staining system.

RESULTS

No significant difference in postprocedural joint swelling was observed between LRS and HYPER treatment groups. Percent increments in femorotibial joint dimensions (mean ± SD) were seen in both treatment groups based on US (LRS, 83.9 ± 84.6%; HYPER, 131.2 ± 144.9%) and caliper measurements (LRS 5.5 ± 4.3%; HYPER 7.5 ± 5.8%) (P ≤ .05). Chondrocyte viability and tissue water content were maintained in both treatment groups, and differences were not statistically significant.

CLINICAL RELEVANCE

Doubling the osmolarity of an irrigation solution used routinely for arthroscopy does not result in detrimental effects on chondrocyte viability or tissue water content. However, use of a relatively HYPER irrigation solution did not attenuate procedural tissue swelling of the equine stifle joint.

Open access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate expression of cyclooxygenase (COX)-1 and COX-2 in the cornea, eyelid, and third eyelid of healthy horses and those affected with squamous cell carcinoma (SCC) by use of immunohistochemical techniques.

Animals—15 horses with SCC involving ocular tissues and 5 unaffected control horses.

Procedures—SCC-affected tissues were obtained from the cornea (n = 5 horses), eyelid (5), and third eyelid (5). Site-matched control tissues were obtained from 5 horses unaffected with SCC. Tissue sections of affected and control cornea, eyelid, and third eyelid were stained immunohistochemically for COX-1 and COX-2 via standard techniques. Stain uptake was quantified by use of computer-assisted image analysis of digital photomicrographs.

Results—Immunoreactivity for both COX-1 and COX-2 was significantly greater in equine corneas with SCC than in control corneas. No significant differences in COX-1 or COX-2 immunoreactivity were detected in eyelid and third-eyelid SCC, compared with site-matched control tissues.

Conclusions and Clinical Relevance—Immunoreactivity for COX-1 and COX-2 is high in equine corneal SCC, possibly indicating that COX plays a role in oncogenesis or progression of this tumor type at this site. Pharmacologic inhibition of COX may represent a useful adjunctive treatment for corneal SCC in horses.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine whether increased gene expression of a disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS-4) in laminae of horses with starch gruel–induced laminitis was accompanied by increased enzyme activity and substrate degradation.

Sample—Laminae from the forelimb hooves of 8 healthy horses and 17 horses with starch gruel–induced laminitis (6 at onset of fever, 6 at onset of Obel grade 1 lameness, and 5 at onset of Obel grade 3 lameness).

Procedures—Gene expression was determined by use of cDNA and real-time quantitative PCR assay. Protein expression and processing were determined via SDS-PAGE and quantitative western blotting. Protein distribution and abundance were determined via quantitative immunofluorescent staining.

Results—ADAMTS-4 gene expression was increased and that of versican decreased in laminitic laminae, compared with expression in healthy laminae. Catalytically active ADAMTS-4 also was increased in the tissue, as were ADAMTS-4–cleavage fragments of versican. Immunofluorescent analyses indicated that versican was depleted from the basal epithelia of laminae of horses at onset of Obel grade 3 lameness, compared with results for healthy laminae, and this was accompanied by regional separation of basal epithelial cells from the basement membrane. Aggrecan gene and protein expression were not significantly affected.

Conclusions and Clinical Relevance—Changes in gene and protein expression of ADAMTS-4 and versican in the basal epithelium of laminitic laminae indicated a fundamental change in the physiology of basal epithelial cells. This was accompanied by and may have caused detachment of these cells from the basement membrane.

Full access
in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate a continuous glucose monitoring system (CGMS) for use in dogs, cats, and horses.

Design—Prospective clinical study.

Animals—7 horses, 3 cats, and 4 dogs that were clinically normal and 1 horse, 2 cats, and 3 dogs with diabetes mellitus.

Procedure—Interstitial glucose concentrations were monitored and recorded every 5 minutes by use of a CGMS. Interstitial glucose concentrations were compared with whole blood glucose concentrations as determined by a point-of-care glucose meter. Interstitial glucose concentrations were also monitored in 2 clinically normal horses after oral and IV administration of glucose.

Results—There was a positive correlation between interstitial and whole blood glucose concentrations for clinically normal dogs, cats, and horses and those with diabetes mellitus. Events such as feeding, glucose or insulin administration, restraint, and transport to the clinic were recorded by the owner or clinician and could be identified on the graph and associated with time of occurrence.

Conclusions and Clinical Relevance—Our data indicate that use of CGMS is valid for dogs, cats, and horses. This system alleviated the need for multiple blood samples and the stress associated with obtaining those samples. Because hospitalization was not required, information obtained from the CGMS provided a more accurate assessment of the animal's glucose concentrations for an extended period, compared with measurement of blood glucose concentrations. Use of the CGMS will promote the diagnostic and research potential of serial glucose monitoring. (J Am Vet Med Assoc 2003;223: 987–992)

Restricted access
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Abstract

In collaboration with the American College of Veterinary Pathologists

Open access
in Journal of the American Veterinary Medical Association