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- Author or Editor: David D. Frisbie x
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Abstract
Objective
To evaluate potential stimulatory or matrixsparing effects of insulin-like growth factor 1 (IGF-1 ), alone or in combination with a corticosteroid, in an interleukin 1 (IL-1)-induced model of cartilage degradation.
Samples
Cartilage from the weightbearing surfaces of trochlea and condyles of clinically normal 2-year-old male horses.
Procedure
Triamcinolone acetonide and IGF-1 effects were evaluated by assessing: matrix responses by sulfated glycosaminoglycan (GAG) assay and [35S]sulfated GAG synthesis; collagen content by hydroxyproline assay; and mitogenic response by [3H]thymidine incorporation into DNA and fluorometric assay of total DNA concentration.
Results
Conditioning of cartilage expiants with 10 ng of human recombinant IL-1α increased degradation and decreased synthesis of matrix proteoglycans (PG), without affecting matrix collagen content. Human recombinant IGF-1 decreased PG loss and reversed the reduction of PG synthesis in cartilage expiants conditioned with IL-1. Given alone, steroids decreased PG concentration and synthetic rate in normal cartilage. However, the previously diminished PG content, attributable to IL-1 conditioning, was not further exacerbated by steroid administration in IL-1-conditioned expiants. Combined treatment of normal cartilage expiants with IGF-1 and steroids resulted in PG preservation and increase in collagen content. Similar PG and collagen effects were not evident when treating IL-1-conditioned cartilage with IGF-1/steroid combinations. Decrease in chondrocyte proliferation was associated with steroid administration. Exposure to IGF and steroids prevented the decrease in mitogenesis that could lead to cellular loss, particularly in IL-1-conditioned expiants.
Conclusion
Combination IGF-1 and steroid treatment of normal cartilage cultures indicated substantial ability to override the anabolic suppression associated with steroids alone. Potentially, administration of corticosteroids, followed by IGF-1, may act to decrease propagation of detrimental mediator release while allowing appreciation of the chondroenhancing effects of IGF-1. These beneficial effects were considerably reduced in IL-1-induced cartilage damage. (Am J Vet Res 1997;58:524–530)
Abstract
Objective
To evaluate the effects of a commercially defined, serum-free medium additive on equine articular cartilage explants, compared with effects of serum-free and serum-supplemented media.
Animals
Articular cartilage from a 3-year-old, mixed breed horse euthanatized for reasons other than musculoskeletal disease or sepsis.
Procedure
Media were changed every 48 hours, and the glycosaminoglycan (GAG) content was determined in media collected at each time point. Glycosaminoglycan synthesis by explant chondrocytes, and residual GAG content of articular cartilage (as a measure of explant GAG loss) were determined at the end of the study (day 8).
Results
Articular cartilage explants in serum-free medium and the commercial supplemented medium had significantly lower GAG synthesis and GAG content than did those incubated in serum-supplemented medium. There were no significant differences in GAG synthesis and content between serum-free and commercial supplemented medium groups. When comparing medium GAG content for all treatment groups, the GAG content in serum-free medium on day 8 was significantly greater than that in commercial supplemented medium, but significant differences were not evident in percentage of release of GAG (as an indicator of GAG degradation) among all 3 treatment groups.
Conclusions
Commercial supplemented medium had effects on articular cartilage matrix GAG loss into medium equal to those of serum-supplemented medium (eg, both lost articular cartilage explant GAG to a similar degree). However, residual articular cartilage GAG content was higher in serum-supplemented medium, as was GAG synthesis. Commercial supplemented medium appears to either lack the proper ingredients to maintain steadystate GAG synthesis, or lacks proper concentrations of these ingredients. (Am J Vet Res 1996;57:1261–1265)
Abstract
Objective
To determine whether serum or synovial fluid concentrations of chondroitin sulfate epitope 846 and carboxy propeptides of type II collagen (CPII) can be used to diagnose osteochondral fragmentation (OC) in horses.
Animals
38 horses with unilateral OC of the radiocarpal (n = 31) or intercarpal (33) joints and 8 clinically and radiographically normal horses.
Procedures
For horses with OC, serum and synovial fluid concentrations of epitope 846, CPII, and keratan sulfate (KS) were determined, along with synovial fluid WBC counts and total protein concentrations. Serum epitope 846, CPII, and KS concentrations were measured in control horses.
Results
Synovial fluid epitope 846 and total protein concentrations were significantly higher in the joints with OC than in unaffected joints, but CPII and KS concentrations and WBC counts were not. Synovial fluid total protein and 846 epitope concentrations were linearly related to grade of OC. Serum epitope 846 and CPII concentrations were significantly higher in horses with OC than in control horses. Discriminant analysis allowed 27 of 34 (79%) horses to be correctly classified as having or not having OC on the basis of serum epitope 846 and CPII concentrations.
Conclusions
Results suggest that serum and synovial fluid concentrations of epitope 846 and CPII are associated with OC. Increases in concentrations of epitope 846 and CPII suggest that increased synthesis of cartilage aggrecan and type II procollagen may be associated with OC.
Clinical Relevance
Measurement of serum epitope 846 and CPII concentrations may be useful in the diagnosis of OC in horses. (Am J Vet Res 1999;60:306–309)
Abstract
Objective—To determine response of interleukin-1α (IL-1α)-conditioned equine articular cartilage explants to insulin-like growth factor-1 (IGF-1).
Sample Population—Cartilage from the trochlea and condyles of the femur of a clinically normal 4-year-old horse.
Procedure—Effects of IGF-1 (0 to 500 ng/ml) after addition of IL-1α were evaluated by assessing matrix responses, using a sulfated glycosaminoglycan (GAG) assay, matrix 35SO4 GAG incorporation, and release of GAG. Mitogenic response was assessed by 3H-thymidine incorporation into DNA and fluorometric assay of total DNA concentration.
Results—Human recombinant IL-1α (40 ng/ml) increased the amount of labeled GAG released and decreased labeled and total GAG remaining in explants, and IL-1α decreased mitogenic response. Addition of IGF-1 counteracted effects seen with IL-1α alone. In general, IGF-1 decreased total and labeled GAG released into the medium, compared with IL-1α- treated explants (positive-control sample). Values for these variables did not differ significantly from those for negative-control explants. A significant increase in total and newly synthesized GAG in the explants at termination of the experiment was observed with 500 ng of IGF-1/ml. Labeled GAG remaining in explants was greater with treatment at 50 ng of IGF-1/ml, compared with treatment with IL-1α alone. Concentrations of 200 ng of IGF-1/ml abolished actions of IL-1α and restored DNA synthesis to values similar to those of negative-control explants.
Conclusions and Clinical Relevance—IGF-1 at 500 ng/ml was best at overcoming detrimental effects associated with IL-1α in in vitro explants. These beneficial effects may be useful in horses with osteoarthritis. (Am J Vet Res 2000;61:436–441)
Abstract
Objectives—To determine concentrations of matrix metalloproteinase (MMP)-2 and -9 in synovial fluid; and mRNA expression of MMP-1, -13, and -3; interleukin[ IL]-1α and β; and tumor necrosis factor(TNF)-α in synovial membrane and articular cartilage from horses with naturally occurring joint disease.
Sample Population—Synovial fluid (n = 76), synovial membrane (59), and articular cartilage (45) from 5 clinically normal horses and 55 horses with joint disease categorized as traumatic (acute [AT] or chronic [CT]), osteochondritis dissecans (OCD), or septic (S).
Procedure—Synovial fluid gelatinase concentrations were analyzed, using zymography. Synovial membrane and articular cartilage mRNA expression for MMP-1, -3, and -13, IL-1α and β, TNF-α, type-II collagen, and aggrecan were analyzed, using quantitative reverse transcriptase-polymerase chain reaction.
Results—Synovial fluid pro-MMP-2 concentration was significantly higher in diseased joints than normal joints. Septic joints had significantly higher concentrations of pro and active MMP-9. Stromelysin-1 was expressed in ≥ 80% of synovial membrane and articular cartilage samples and was strongly influenced by age. Collagenases were rarely expressed, with MMP- 13 expressed only in diseased joints. Interleukin-1β expression was significantly higher in all OCD samples and was influenced by age. Tumor necrosis factor- α expression was significantly higher in cartilage from joints with AT and OCD. There was no correlation between MMP or cytokines and type-II collagen or aggrecan expression.
Conclusions and Clinical Relevance—Matrix metalloproteinase- 2 and -3 are abundant in naturally occurring joint disease and normal joints. Interleukin-1β and TNF-α may be important in the pathogenesis of OCD. Age affects MMP and IL-1β concentrations. (Am J Vet Res 2001;62:1467–1477)
Abstract
OBJECTIVE To determine accuracy for a technique of needle redirection at a single craniolateral site for injection of 3 compartments of the equine stifle joint, describe the external needle position, and identify the location of the needle tip within each joint compartment.
SAMPLE 24 equine cadaver stifle joints.
PROCEDURES Stifle joints were placed in a customized stand. After the needle was placed, external needle position was measured and recorded. Each joint compartment (medial and lateral compartments of the femorotibial joint and the femoropatellar joint) was injected with a solution containing iodinated contrast medium, water, and dye. Radiography, assessment of intra-articular location of the needle tip, and gross dissection were performed to determine success of entering each joint compartment. Student t tests and an ANOVA were used to compare mean values.
RESULTS Overall accuracy was 19 of 24 (79.1%), and accuracy for individual joint compartments was at least 21 of 24 (87.5%). Mean depth of needle insertion to access each compartment of the stifle joint was 5.71 cm. Mean angle of insertion (relative to the long axis of the tibia) was 82.1°, 80.3°, and 18.5° for the medial compartment of the femorotibial joint, lateral compartment of the femorotibial joint, and femoropatellar joint, respectively, and 28° medial, 7.3° lateral, and 1.3° lateral for the medial compartment of the femorotibial joint, lateral compartment of the femorotibial joint, and femoropatellar joint, respectively.
CONCLUSIONS AND CLINICAL RELEVANCE Results supported that this was an accurate technique for successful injection of the 3 equine stifle joint compartments.
Abstract
Objective—To evaluate use of technetium Tc 99m disodium hydroxymethylene diphosphonate (99m-Tc- HDP) for assessing fracture healing and 99m-Tc-HDP and technetium Tc 99m ciprofloxacin (99m-Tc-CIPRO) for early diagnosis of osteomyelitis in rabbits.
Animals—32 skeletally mature New Zealand White rabbits.
Procedure—A femoral fracture defect stabilized with bone plates and cortical screws was used. Scintigraphy was performed 4, 8, 12, and 16 weeks after surgery. The 99m-Tc-CIPRO scan was performed 48 hours after the 99m-Tc-HDP scan. The uptake ratio of the experimental limb to the normal limb was calculated by use of multiple regions of interest. Results of radiography performed to determine external callus and lysis grade and percentage defect ossification at 16 weeks were compared with scintigraphy results.
Results—Infected fractures had a higher uptake ratio for 99m-Tc-HDP and 99m-Tc-CIPRO than noninfected fractures. Infected fractures could be differentiated from noninfected fractures late in healing by use of 99m-Tc-HDP. Although 99m-Tc-CIPRO was better than 99m-Tc-HDP for identifying infection, there was a high incidence of false positive and negative results with 99m-Tc-CIPRO. There was an association between 99m-Tc-HDP uptake ratio and callus formation and a good correlation between 99m-Tc-HDP uptake ratio and defect ossification after 4 weeks.
Conclusions and Clinical Relevance—99m-Tc-HDP and 99m-Tc-CIPRO may be useful for diagnosing osteomyelitis late in fracture healing; however, false positive and false negative results occur. Technetium Tc 99m disodium hydroxymethylene diphosphonate may be useful for evaluating fracture healing. ( Am J Vet Res 2003;64:736–745)
Abstract
OBJECTIVE To determine the effects of altering location of right forelimb and pelvic sensors on kinematic data obtained with a commonly used inertial sensor system during gait analysis of trotting horses.
DESIGN Experimental study.
ANIMALS 12 horses with mild to moderate lameness of at least 1 hind limb, with or without lameness of the forelimbs.
PROCEDURES All horses were examined while trotting on a high-speed treadmill. The right forelimb sensor was tested at 3 anatomic locations in random order: dorsal midline and 2 cm medial and lateral to that midline. During another treadmill session, the pelvic sensor was tested at 5 anatomic locations in random order: dorsal midline, 2 cm to the right and left of midline, and 2 cm cranial and caudal to the tubera sacrale on the midline. Laterality of the pelvic sensor was analyzed in 2 ways: sensor toward the right or left and sensor toward or away from the lame or lamest hind limb. Maximum and minimum differences in head and pelvic motion and vector sum values were ranked and compared with values for the midline location by means of mixed-model ANOVA.
RESULTS Altering the location of the right forelimb sensor by 2 cm medially or laterally had no significant effect on forelimb or hind limb kinematics. However, location of the pelvic sensor had a significant effect on minimum difference in pelvic motion, regardless of whether the data were analyzed by laterality (right vs left) or toward versus away from the lame hind limb.
CONCLUSIONS AND CLINICAL RELEVANCE Results of this study indicated that a 2-cm change in the location of the pelvic sensor during kinematic gait analysis had a significant effect on hind limb kinematic data of the system used. Therefore, placement of this sensor needs to be anatomically accurate.
Abstract
OBJECTIVE To investigate potential associations between repository radiographic findings and subsequent performance of Quarter Horses competing in cutting events.
DESIGN Retrospective cohort study.
SAMPLE Repository radiographs (ie, radiographs obtained at the time of sale) for 343 client-owned horses.
PROCEDURES Repository radiographic findings were compared with objective measures of performance, including the likelihood of competing; the likelihood of earning money as a 3-year-old, as a 4-year-old, and as a 3- and 4-year-old combined; and the amount of money earned as a 3-year-old, as a 4-year-old, and as a 3- and 4-year-old combined.
RESULTS The presence of mild osteophytes involving the distal aspect of the tarsal joint was significantly associated with lower mean earnings as a 4-year-old. The presence of osteophytes on the dorsoproximal aspect of the middle phalanx of the hind limbs was significantly associated with an increased odds of earning money as a 4-year-old. Radiographic lesions of the medial femoral condyle of the stifle joint were not significantly associated with subsequent performance.
CONCLUSIONS AND CLINICAL RELEVANCE Most abnormalities identified on repository radiographs were not significantly associated with subsequent performance. The significant association between mild tarsal osteophytosis and earnings was unexpected. Results of the present study indicated the need for further investigation of the relationship between radiographic findings and performance outcome in Western performance horses.