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Abstract

OBJECTIVE To evaluate the reasons for and outcomes of gastrointestinal tract surgery in pet pigs.

DESIGN Retrospective case series.

ANIMALS 11 pigs.

PROCEDURES The medical record database of a teaching hospital was searched to identify pet pigs that underwent at least 1 celiotomy because of a possible gastrointestinal tract obstruction between 2004 and 2015. For each pig, information extracted from the medical record included history; signalment; clinical signs; physical examination, diagnostic imaging, and diagnostic test results; perioperative management; surgical diagnosis, duration, and procedures performed; postoperative complications; and outcome. Descriptive data were generated.

RESULTS 11 pet pigs underwent 12 celiotomies during the study period. Five pigs with intestinal obstructions caused by foreign bodies survived to hospital discharge. Four pigs were euthanized during surgery: 2 because of extensive adhesions that prevented correction of an intestinal obstruction, 1 because of a perforated spiral colon, and 1 because of neoplasia. One pig with a fecal impaction in the spiral colon died during anesthetic recovery. A diagnosis was not achieved for 1 pig, which was euthanized after surgery because of a deteriorating clinical condition. For the pig that underwent 2 celiotomies, the first procedure was an enterotomy for removal of a foreign body, and the second was an intestinal bypass of a stricture caused by adhesions at the previous enterotomy site.

CONCLUSIONS AND CLINICAL RELEVANCE Results indicated prognosis was good for pet pigs following surgical removal of gastrointestinal foreign bodies; however, the presence or development of intra-abdominal adhesions appeared to adversely affect prognosis.

Restricted access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To investigate in vitro effects of radial shock waves on membrane permeability, viability, and structure of chondrocytes and articular cartilage.

Sample Population—Cartilage explants obtained from the third metacarpal and metatarsal bones of 6 horses.

Procedure—Equine cartilage was subjected to radial shock waves and then maintained as explants in culture for 48 hours. Treatment groups consisted of a negative control group; application of 500, 2,000, and 4,000 impulses by use of a convex handpiece (group A); and application of 500, 2,000, and 4,000 impulses by use of a concave handpiece (group B). Effects on explant structure were evaluated by use of environmental scanning electron microscopy (ESEM). Membrane permeability was determined by release of lactate dehydrogenase (LDH). Chondrocyte viability was assessed by use of vital cell staining. Comparisons of LDH activity and nonviable cell percentages were performed by ANOVA.

Results—Cell membrane permeability increased significantly after application of 2,000 and 4,000 impulses in groups A and B. A significant decrease in cell viability was observed for application of 4,000 impulses in explants of group A. There was no detectable damage to integrity of cartilage explants observed in any treatment group by use of ESEM.

Conclusions and Clinical Relevance—Radial shock waves do not appear to structurally damage articular cartilage but do impact chondrocyte viability and membrane permeability. Caution should be exercised when extremely high periarticular pulse doses are used until additional studies can determine the longterm outcome of these effects and appropriate periarticular treatment regimens can be validated. (Am J Vet Res 2005;66:1757–1763)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine whether fibroblast growth factor-2 (FGF-2) treatment of equine mesenchymal stem cells (MSCs) during monolayer expansion enhances subsequent chondrogenesis in a 3-dimensional culture system.

Animals—6 healthy horses, 6 months to 5 years of age.

Procedures—Bone marrow–derived MSCs were obtained from 6 horses. First-passage MSCs were seeded as monolayers at 10,000 cells/cm2 and in medium containing 0, 1, 10, or 100 ng of FGF-2/mL. After 6 days, MSCs were transferred to pellet cultures (200,000 cells/pellet) and maintained in chondrogenic medium. Pellets were collected after 15 days. Pellets were analyzed for collagen type II content by use of an ELISA, total glycosaminoglycan content by use of the dimethylmethylene blue dye–binding assay, and DNA content by use of fluorometric quantification. Semiquantitative PCR assay was performed to assess relative concentrations of collagen type II and aggrecan mRNAs.

Results—Use of 100 ng of FGF-2/mL significantly increased pellet DNA and glycosaminoglycan content. Collagen type II content of the pellet was also increased by use of 10 and 100 ng of FGF-2/mL. Collagen type II and aggrecan mRNA transcripts were increased by treatment with FGF-2. Some control samples had minimal evidence of collagen type II and aggrecan transcripts after 35 cycles of amplification.

Conclusions and Clinical Relevance—FGF-2 treatment of bone marrow–derived MSC monolayers enhanced subsequent chondrogenic differentiation in a 3-dimensional culture. This result is important for tissue engineering strategies dependent on MSC expansion for cartilage repair.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate the effects of methylprednisolone acetate (MPA) on proteoglycan production by equine chondrocytes and to investigate whether glucosamine hydrochloride modulates these effects at clinically relevant concentrations.

Sample Population—Articular cartilage with normal gross appearance from metacarpophalangeal and metatarsophalangeal joints of 8 horses (1 to 10 years of age).

Procedures—In vitro chondrocyte pellets were pretreated with glucosamine (0, 1, 10, and 100 μg/mL) for 48 hours and exposed to MPA (0, 0.05, and 0.5 mg/mL) for 24 hours. Pellets and media were assayed for proteoglycan production (Alcian blue precipitation) and proteoglycan content (dimethylmethylene blue assay), and pellets were assayed for DNA content.

Results—Methylprednisolone decreased production of proteoglycan by equine chondrocytes at both concentrations studied. Glucosamine protected proteoglycan production at all 3 concentrations studied.

Conclusions and Clinical Relevance—Methylprednisolone, under noninflammatory conditions present in this study, decreased production of proteoglycan by equine chondrocytes. Glucosamine had a protective effect against inhibition of proteoglycan production at all 3 concentrations studied. This suggested that glucosamine may be useful as an adjunct treatment when an intra-articular injection of a corticosteroid is indicated and that it may be efficacious at concentrations relevant to clinical use.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine whether expansion of equine mesenchymal stem cells (MSCs) by use of fibroblast growth factor-2 (FGF-2) prior to supplementation with dexamethasone during the chondrogenic pellet culture phase would increase chondrocytic matrix markers without stimulating a hypertrophic chondrocytic phenotype.

Sample Population—MSCs obtained from 5 young horses.

Procedures—First-passage equine monolayer MSCs were supplemented with medium containing FGF-2 (0 or 100 ng/mL). Confluent MSCs were transferred to pellet cultures and maintained in chondrogenic medium containing 0 or 10−7M dexamethasone. Pellets were collected after 1, 7, and 14 days and analyzed for collagen type II protein content; total glycosaminoglycan content; total DNA content; alkaline phosphatase (ALP) activity; and mRNA of aggrecan, collagen type II, ALP, and elongation factor-1α.

Results—Treatment with FGF-2, dexamethasone, or both increased pellet collagen type II content, total glycosaminoglycan content, and mRNA expression of aggrecan. The DNA content of the MSC control pellets decreased over time. Treatment with FGF-2, dexamethasone, or both prevented the loss in pellet DNA content over time. Pellet ALP activity and mRNA were increased in MSCs treated with dexamethasone and FGF-2–dexamethasone. After pellet protein data were standardized on the basis of DNA content, only ALP activity of MSCs treated with FGF-2–dexamethasone remained significantly increased.

Conclusions and Clinical Relevance—Dexamethasone and FGF-2 enhanced chondrogenic differentiation of MSCs, primarily through an increase in MSC numbers. Treatment with dexamethasone stimulated ALP activity and ALP mRNA, consistent with the progression of cartilage toward bone. This may be important for MSC-based repair of articular cartilage.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate the effects of glucosamine on equine articular chondrocytes and synoviocytes at concentrations clinically relevant to serum and synovial fluid concentrations.

Sample Population—Articular cartilage and synovium with normal gross appearance from metacarpophalangeal and metatarsophalangeal joints of 8 horses (1 to 10 years of age).

Procedures—In vitro chondrocyte and synoviocyte cell cultures from 8 horses were treated with glucosamine (0.1 to 20 μg/mL) with or without interleukin-1 (IL-1; 10 ng/mL) for 48 hours. Negative control cultures received no glucosamine or IL-1, and positive control cultures received only IL-1. Cultures were assayed for production of proteoglycan (via media containing sulfur 35 (35S)-labeled sodium sulfate and Alcian blue precipitation), prostaglandin E2 (PGE2; via a colorimetric assay), cyclooxygenase-2 (via real-time reverse-transcriptase PCR assay), microsomal PGE2 synthase (mPGEs; via real-time reverse-transcriptase PCR assay), and matrix metalloproteinase (MMP)-13 (via a colorimetric assay).

Results—Glucosamine had no impact on proteoglycan production or MMP-13 production under noninflammatory (no IL-1) or inflammatory (with IL-1) conditions. Glucosamine at 0.1 and 0.5 μg/mL significantly decreased IL-1–stimulated production of mPGEs by chondrocytes, compared with that of positive control chondrocytes. Glucosamine at 0.1 and 5 μg/mL significantly decreased IL-1–stimulated production of mPGEs and PGE2, respectively, compared with that of positive control synoviocytes.

Conclusions and Clinical Relevance—Glucosamine had limited effects on chondrocyte and synoviocyte metabolism at clinically relevant concentrations, although it did have some anti-inflammatory activity on IL-1–stimulated articular cells. Glucosamine may have use at clinically relevant concentrations in the treatment of inflammatory joint disease.

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE To compare the effects of 3 equimolar concentrations of methylprednisolone acetate (MPA), triamcinolone acetonide (TA), and isoflupredone acetate (IPA) on equine articular tissue cocultures in an inflammatory environment.

SAMPLE Synovial and osteochondral explants from the femoropatellar joints of 6 equine cadavers (age, 2 to 11 years) without evidence of musculoskeletal disease.

PROCEDURES From each cadaver, synovial and osteochondral explants were harvested from 1 femoropatellar joint to create cocultures. Cocultures were incubated for 96 hours with (positive control) or without (negative control) interleukin (IL)-1β (10 ng/mL) or with IL-1β and MPA, TA, or IPA at a concentration of 10−4, 10−7, or 10−10M. Culture medium samples were collected from each coculture after 48 and 96 hours of incubation. Concentrations of prostaglandin E2, matrix metalloproteinase-13, lactate dehydrogenase, and glycosaminoglycan were determined and compared among treatments at each time.

RESULTS In general, low concentrations (10−7 and 10−10M) of MPA, TA, and IPA mitigated the inflammatory and catabolic (as determined by prostaglandin E2 and matrix metalloproteinase-13 quantification, respectively) effects of IL-1β in cocultures to a greater extent than the high (10−4M) concentration. Mean culture medium lactate dehydrogenase concentration for the 10−4M IPA treatment was significantly greater than that for the positive control at both times, which was suggestive of cytotoxicosis. Mean culture medium glycosaminoglycan concentration did not differ significantly.

CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that the in vitro effects of IPA and MPA were similar to those of TA at clinically relevant concentrations (10−7 and 10−10M).

Full access
in American Journal of Veterinary Research

Abstract

Objective—To characterize potential mechanisms of action of glucosamine inhibition of matrix metalloproteinase (MMP) expression and activity in lipopolysaccharide (LPS)-stimulated equine chondrocytes.

Sample Population—Chondrocytes cultured from samples of metacarpophalangeal articular cartilage collected from cadaveric limbs of horses.

Procedure—The effect of glucosamine on MMP activity in conditioned medium from LPS-stimulated cartilage explants was determined by a colorimetric assay with azocoll substrate. Treatments consisted of negative and positive controls, glucose (50mM), and glucosamine (50, 25, 6.25, 3, and 1.5mM). The influence of glucosamine on MMP synthesis was determined in chondrocytes in pellet culture incubated with LPS (20 µg/mL). Concentration of MMP-13 was quantified in spent medium via ELISA; nonspecific MMP activity was determined via azocoll digestion in organomercurial- activated medium. Effects of glucosamine on MMP mRNA concentration in similarly treated chondrocytes were determined by northern blot hybridization with MMP-1, -3, and -13 probes. Statistical analyses were performed with 2-way ANOVA.

Results—Glucosamine had no effect on activated MMP activity but inhibited MMP protein expression, as determined by azocoll digestion (glucosamine, 3 to 50mM) and MMP-13 ELISA (glucosamine, 1.5 to 50mM). Resting mRNA concentrations for MMP-1, -3, and -13 mRNA were significantly lower in cultures exposed to glucosamine at concentrations of 50 and 25mM than those of positive controls.

Conclusions and Clinical Relevance—Glucosamine appears capable of pretranslational, and possibly also translational, regulation of MMP expression; data suggest a potential mechanism of action for chondroprotective effects of this aminomonosaccharide. ( Am J Vet Res 2003;64:666–671)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine the effects of sodium hyaluronate (HA) in combination with methylprednisolone acetate (MPA) on interleukin-1 (IL-1)–induced inflammation in equine articular cartilage pellets.

Sample Population—Chondrocytes collected from 7 horses euthanatized for problems unrelated to the musculoskeletal system.

Procedures—Chondrocyte pellets were treated with medium (negative control); medium containing IL-1 (positive control); or medium containing IL-1 with MPA only (0.05 or 0.5 mg/mL), HA only (0.2 or 2 mg/mL), or MPA (0.05 or 0.5 mg/mL) and HA (0.2 or 2 mg/mL) in combination. Proteoglycan (PG) synthesis was determined by incorporation of sulfur 35–labeled sodium sulfate into PGs. Glycosaminoglycan (GAG) content of the media and the pellets and total pellet DNA content were determined.

Results—Methylprednisolone acetate at 0.5 mg/mL caused an increase in PG synthesis, whereas HA had no effect alone. The combination of MPA, both 0.05 mg/mL and 0.5 mg/mL, with HA at 2 mg/mL increased PG synthesis, compared with IL-1–treated control. All treatment groups containing the high concentration of MPA (0.5 mg/mL) and the high concentration of HA (2.0 mg/mL) had pellets with increased GAG content. The addition of HA caused an increase in total GAG content in the media, regardless of MPA treatment. Cyclooxygenase-2 mRNA and aggrecan mRNA expression was significantly reduced with MPA treatment. Total pellet DNA content was unchanged by any treatment.

Conclusions and Clinical Relevance—Our results indicate that MPA in combination with HA has beneficial effects on PG metabolism of IL-1–treated equine chondrocytes.

Full access
in American Journal of Veterinary Research