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SUMMARY

In 6 anesthetized ponies, 3 segments of jejunum and 3 segments of small colon were isolated from the peritoneal cavity in plastic bags filled with Hanks' balanced salt solution. One jejunal and 1 small colon segment were subjected to venous strangulation obstruction for 3 hours (vso-3), venous strangulation obstruction for 6 hours (vso-6), or a 6-hour sham procedure to control for changes induced by isolation in a plastic bag. Additional segments of jejunum and colon that were not placed in bags served as controls for histologic examination and collagenase measurements. Samples of fluid surrounding the intestine were obtained for chemical analyses, nucleated cell count, aerobic and anaerobic bacteriologic culture, and measurement of collagenase activity. Full-thickness tissue samples were obtained for histologic examination and measurement of collagenase content.

Bacteria did not cross the intestinal wall after 3 and 6 hours of vso, despite severe mucosal lesions in these segments. At 6 hours, Po2 was significantly less and Pco2 was significantly (P<0.05) greater in the fluid surrounding the vso-6 jejunal segments, compared with the sham jejunal segments. The pH was significantly (P<0.05) less in fluid surrounding vso-6 small colon segments, compared with the sham colon segments at 6 hours. For jejunum and small colon, phosphate and lactate concentrations were significantly (P<0.05) greater in vso-6 fluid than in the corresponding sham fluids at 6 hours. Fibrin formed around all vso segments, although fibrinogen was not detected in the surrounding fluid, indicating possible rapid conversion of fibrinogen to fibrin. Fluid collagenase activity increased significantly (P<0.05) in all segments over 6 hours. The preparation used in this study was successful in measuring local changes on the serosal surface of intestine subjected to vso and in isolating segments under study in a sterile environment.

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in American Journal of Veterinary Research

Abstract

Objectives

To use lipopolysaccharide (LPS) to create synovitis in the midcarpal joint of ponies, and to assess the morphologic, histochemical, and immunohistochemical effects of synovitis on articular cartilage of the third carpal bone.

Animals

2- to 3-year-old ponies, 6 control (group 1) and 6 treated (group 2).

Procedure

Synovitis was induced in 1 midcarpal joint of group-2 ponies by intra-articular injections of LPS (0.02 μg/kg of body weight), morphine (0.1 mg/kg), and saline solution (group 2a) and morphine and saline solution alone in the contralateral midcarpal joint (group 2b). Articular cartilage sections and attached synovial membrane from the third carpal bones were examined by immunohistochemical distribution of interleukin 1β, tumor necrosis factor (TNF)-α, TNF receptors (P55, P75) and 3-B-3(–) epitopes, and by localization of proteoglycans (metachromatic staining). Proteoglycan extracts were assessed by metachromatic staining or western blotting and immunohistochemical staining, using anti-3-B-3 antibodies.

Results

Enhanced immunoreactivity for the cytokines and receptors was found in inflamed synovial membrane and noncalcified cartilage (group 2a more than 2b). Metachromasia of the noncalcified cartilage was greater in group-1 than in group-2a and group-2b specimens. In group 2a, chondrocyte hypertrophy and enhanced immunoreactivity for 3-B-3(–) epitope in areas of increased cytokine immunoreactivity suggested possible phenotypic change of the chondrocytes in response to synovitis. Immunohistochemical analysis by western blotting of proteoglycan extracts indicated strong 3-B-3(–) epitope immunolocalization in group-2a, weaker staining in group-2b, and barely detectable stain in group-1 specimens, which correlated with in situ immunolocalization.

Conclusions

Intra-articular administration of LPS may be used to induce a synovial environment conducive to increased immunoreactivity of interleukin 1β, TNF-α, and its receptors in equine synovial membrane and articular cartilage. These cytokines may be involved in the early phenotypic change of chondrocytes that is believed to occur in osteoarthritis and is characterized in this study by enhanced 3-B-3(–) epitope immunoreactivity and chondrocyte hypertrophy. (Am J Vet Res 1996;57:1080–1093)

Free access
in American Journal of Veterinary Research

investigated extensively in human and laboratory animal medicine. 9 The ideal sealant is easy to use, biocompatible, inexpensive, and effective for holding 2 tissue surfaces together in a moist environment. It should also be biodegradable, and its use should

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in American Journal of Veterinary Research

contributing factors to persistent surface contamination. 16 In 1 study, 37 only 50% of high-touch surfaces in a human hospital were appropriately disinfected by cleaning staff. The ability for bacterial pathogens to persist in the environment and disseminate

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in American Journal of Veterinary Research

presurgical assessment was performed in each dog's home environment. The WMD was calibrated, and data collection by the receiver was confirmed. The receiver was secured to a harness worn by the dog, and the WMD was administered by manually placing the capsule

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in American Journal of Veterinary Research

Ergonomics, the science of adapting work environments to workers, 1 is a multidisciplinary field that studies people's characteristics, needs, abilities, and skills and focuses on those aspects that affect product design or work processes

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in American Journal of Veterinary Research

.1177/039139880502801109 2. Nair PD . Currently practised sterilization methods–some inadvertent consequences . J Biomater Appl 1995 ; 10 : 121 – 135 . 10.1177/088532829501000203 3. Deng M Shalaby SW . Effects of γ irradiation, gas environments, and

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in American Journal of Veterinary Research

-treatment management, and characteristics unique to the Galápagos environment. In this project, dogs were returned to their free-roaming environment within hours of treatment. They were physically active and were not restrained from irritating the injection site. A few

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in American Journal of Veterinary Research

provides an antibacterial environment at the suture site and in surrounding tissues. 12,13 As a result of elution that protects incision sites, multiple mechanisms of bacterial killing, and high concentrations relative to the minimum inhibitory

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in American Journal of Veterinary Research

-quality stainless steel. In particular, contents of chromium and molybdenum were specified to ensure adequate resistance to pitting corrosion in the physiologic environment. 13,21 Notably, many 316L stainless steel devices manufactured in the 1960s and 1970s were

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in American Journal of Veterinary Research