Search Results
You are looking at 51 - 60 of 71 items for
- Author or Editor: Lisa A. Fortier x
- Refine by Access: All Content x
Summary
Ten horses with histologically confirmed squamous cell carcinoma (scc) and 1 horse with presumptive scc of the external genitalia were treated with a combination of surgical debridement and topical administration of 5-fluorouracil, or with topical treatment alone. Tumor remission was obtained in all horses except 1 in which owner compliance was deficient, and no recurrences have been reported. Topical use of 5-fluorouracil as a chemotherapeutic agent for treatment of genital lesions of scc in horses should be considered as a viable alternative to radical surgical excision.
Abstract
Objective—To assess the effects of supraphysiologic concentrations of insulin-like growth factor-I (IGF-1) on morphologic and phenotypic responses of chondrocytes.
Sample Population—Articular cartilage obtained from 2 young horses.
Procedure—Chondrocytes were suspended in fibrin cultures and supplemented with 25, 12.5, or 0 mg of IGF-1/ml of fibrin. Chondrocyte morphology and phenotypic expression were assessed histologically, using H&E and Alcian blue stains, immunoreaction to collagen type I and II, and in situ hybridization. Proteoglycan content, synthesis, and monomer size were analyzed. The DNA content was determined by bisbenzimide-fluorometric assay, and elution of IGF-1 into medium was determined by IGF-1 radioimmunoassay.
Results—Both 12.5 and 25 µg of IGF-1/ml enhanced phenotypic expression of chondrocytes without inducing detrimental cellular or metabolic effects. Highest concentration of IGF-1 (25 µg/ml) significantly increased total DNA content, glycosaminoglycan (GAG) content, GAG synthesis, and size of proteoglycan monomers produced, compared with cultures supplemented with 12.5 µg of IGF-1/ml or untreated cultures. Histologic examination confirmed these biochemical effects. Matrix metachromasia, type-II collagen in situ hybridization and immunoreaction were increased in cultures treated with 25 µg of IGF-1/ml, compared with cultures supplemented with 12.5 µg of IGF-1/ml or untreated cultures.
Conclusions and Clinical Relevance—Chondrocytes exposed to high concentrations of IGF-1 maintained differentiated chondrocyte morphology and had enhanced synthesis of matrix molecules without inducing apparent detrimental effects on chondrocyte metabolism. These results suggest that application of such composites for in vivo use during cartilage grafting procedures should provide an anabolic effect on the grafted cells. (Am J Vet Res 2002;63:301–305)
Summary
Medical records from 119 horses that had undergone arthroscopic surgery for removal of axial osteochondral fragments of the palmar/plantar proximal aspect of the proximal phalanx were reviewed. Standardbred racehorses represented 109 (92%) of those affected. Ninety-three (78%) of the horses were < 3 years old. Gender distribution was consistent with that of the equine hospital population. Fragments most commonly were observed in the hind limbs (155/164; 95%), specifically, on the medial aspect of the left hind limb (72/164; 44%). Bilateral fragmentation occurred in 21 of 119 (18%) horses, and 15 of 119 (13%) horses had fragments in the medial and lateral aspect within the same joint. Fifteen (13%) horses had a concurrent osteochondritis dissecans lesion on the distal intermediate ridge of the tibia, and 30 of 119 (25%) had radiographic signs of osteoarthritis involving the centrodistal (distal intertarsal) and tarsometatarsal articulations.
In 55 of 87 (63%) racehorses and in 100% of the 9 nonracehorses, performance returned to preoperative levels after surgery. Fragment numbers or distribution, concurrent osteochondritis dissecans lesions of the distal intermediate ridge of the tibia, or tarsal osteoarthritis were not significantly associated with outcome. Abnormal surgical findings, consisting of articular cartilage fibrillation or synovial proliferation, were significantly (P < 0.0001) associated with adverse outcome; these findings were documented in 31% of the 32 horses without successful outcome and in only 2% of the 55 horses with successful outcomes.
Abstract
OBJECTIVE To determine whether major histocompatability complex (MHC) class II expression in equine mesenchymal stem cells (MSCs) changes with exposure to a proinflammatory environment reflective of an inflamed joint.
SAMPLE Cryopreserved bone marrow-derived MSCs from 12 horses and cartilage and synovium samples from 1 horse euthanized for reasons other than lameness.
PROCEDURES In part 1 of a 3-part study, the suitability of a quantitative reverse transcriptase PCR (qRT-PCR) assay for measurement of MHC class II expression in MSCs following stimulation with interferon (IFN)-γ was assessed. In part 2, synoviocyte-cartilage cocultures were or were not stimulated with interleukin (IL)-1β (10 ng/mL) to generate conditioned media that did and did not (control) mimic an inflamed joint environment. In part 3, a qRT-PCR assay was used to measure MSC MHC class II expression after 96 hours of incubation with 1 of 6 treatments (control-conditioned medium, IL-1β-conditioned medium, and MSC medium alone [untreated control] or with IL-1β [10 ng/mL], tumor necrosis factor-α [10 ng/mL], or IFN-γ [100 ng/mL]).
RESULTS The qRT-PCR assay accurately measured MHC class II expression. Compared with MHC class II expression for MSCs exposed to the untreated control medium, that for MSCs exposed to IL-1β was decreased, whereas that for MSCs exposed to IFN-γ was increased. Neither the control-conditioned nor tumor necrosis factor-α medium altered MHC class II expression.
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that MSC exposure to proinflammatory cytokine IL-1β decreased MHC class II expression and antigenicity. Treatment of inflamed joints with allogeneic MSCs might not be contraindicated, but further investigation is warranted.
