Objective—To compare the mesenchymal stem cell (MSC) yield and chondrogenic and osteogenic differentiation from 5- and 50-mL bone marrow aspirates from horses.
Animals—Six 2- to 5-year-old mixed-breed horses.
Procedures—2 sequential 5-mL aspirates were drawn from 1 ilium or sternebra. A single 50-mL aspirate was drawn from the contralateral ilium, and 2 sequential 50-mL aspirates were drawn from a second sternebra. The MSC yield was determined through the culture expansion process. Chondrogenesis and osteogenesis were evaluated by means of conventional laboratory methods.
Results—The second of the 2 sequential 50-mL sternal aspirates yielded few to no MSCs. Independent of location, the highest density of MSCs was in the first of the 2 sequential 5-mL fractions, although with subsequent culture expansion, the overall yield was not significantly different between the first 5-mL and first 50-mL fractions. Independent of location, chondrogenesis and osteogenesis were not significantly different among fractions. Independent of fraction, the overall cell yield and chondrogenesis from the ilium were significantly higher than that from the sternum.
Conclusions and Clinical Relevance—This study failed to detect an additional benefit of 50-mL aspirates over 5-mL aspirates for culture-expanding MSCs for equine clinical applications. Chondrogenesis was highest for MSCs from ilial aspirates, although it is not known whether chondrogenesis is indicative of activation of other proposed pathways by which MSCs heal tissues.
Objective—To evaluate the use of serum concentrations
of biochemical markers of bone metabolism
(osteocalcin [OC], bone-specific alkaline phosphatase
[BS-ALP], and deoxypyridinoline [DPYR]) to compare
healing in infected versus noninfected fractures and in
fractures with normal repair versus delayed (nonunion)
repair in rabbits.
Animals—32 female 9- to 10-month-old New Zealand
Procedure—A femoral fracture defect was made in
each rabbit. Rabbits were assigned to the following
groups: the bone morphogenetic-2 gene treatment
group with either noninfected nonunion or infected (ie,
inoculation of defects with Staphylococcus aureus)
nonunion fractures or the luciferase (control) gene
treatment group with either noninfected nonunion or
infected nonunion fractures. Serum samples were
obtained before surgery (time 0) and 4, 8, 12, and 16
weeks after surgery. Callus formation and lysis grades
were evaluated radiographically at 16 weeks.
Results—Serum OC and BS-ALP concentrations
decreased from time 0 at 4 weeks, peaked at 8
weeks, and then decreased. Serum DPYR concentration
peaked at 4 weeks and then decreased, independent
of gene treatment group or fracture infection
status. Compared with rabbits with noninfected fractures,
those with infected fractures had lower serum
OC and BS-ALP concentrations at 4 weeks, higher
serum OC concentrations at 16 weeks, and higher
serum DPYR concentrations at 4, 8, and 16 weeks.
Combined serum OC, BS-ALP, and DPYR concentrations
provided an accuracy of 96% for prediction of
fracture infection status at 4 weeks.
Conclusions and Clinical Relevance—Measurement
of multiple serum biochemical markers of bone
metabolism could be useful for clinical evaluation of
fracture healing and early diagnosis of osteomyelitis.
( J Am Vet Med Assoc 2003;64:727–735)
Objective—To assess the clinical, biochemical, and histologic effects of extracorporeal shock wave therapy (ESWT) in the treatment of horses with experimentally induced osteoarthritis (OA).
Animals—Twenty-four 2- to 3-year-old horses without evidence of lameness.
Procedures—OA was induced arthroscopically in 1 middle carpal joint of each horse. Fourteen days after induction of OA, horses were treated with a sham ESWT probe (placebo; n = 8), polysulfated glycosaminoglycan (PSGAG) administered IM every 4 days for 28 days as a positive control treatment (8), or ESWT administered on days 14 and 28 with a focused shock wave unit (8). Evaluations included clinical assessments of degree of lameness every 2 weeks and weekly synovial fluid analyses. Horses were euthanized 70 days after induction of OA, and gross pathologic and histologic examinations of cartilage and synovial membrane specimens were performed at necropsy. A generalized linear mixed model was used to compare outcomes among treatment groups.
Results—No adverse treatment-related events were detected in any horse. The degree of lameness in horses treated with ESWT improved significantly, compared with the degree of lameness in placebo- or PSGAG-treated horses. No disease-modifying effects were evident in results for synovial fluid, synovial membranes, or cartilage from the ESWT- or PSGAG-treated horses.
Conclusions and Clinical Relevance—Although a disease-modifying effect of ESWT was not detected, the significant clinical effect of ESWT suggested that this modality should be considered for treatment of horses with OA in combination with another modality that does affect the disease process.
Objective—To use microarray analysis to identify genes that are differentially expressed in horses with experimentally induced osteoarthritis.
Procedures—During arthroscopic surgery, a fragment was created in the distal aspect of the radiocarpal bone in 1 forelimb of each horse to induce osteoarthritis. At day 14 after osteoarthritis induction, horses began exercise on a treadmill. Blood and synovial fluid samples were collected before and after surgery. At day 70, horses were euthanized and tissues were harvested for RNA analysis. An equine-specific microarray was used to measure RNA expression in peripheral WBCs. These data were compared with mRNA expression (determined via PCR assay) in WBCs, cartilage, and synovium as well as 2 protein biomarkers of cartilage matrix turnover in serum and synovial fluid.
Results—A metalloproteinase domain-like protein decysin-1 (ADAMDEC1), glucose-regulated protein (GRP) 94, hematopoietic cell signal transducer (HCST), Unc-93 homolog A (hUNC-93A), and ribonucleotide reductase M2 polypeptide (RRM2) were significantly differentially regulated in WBCs of horses with osteoarthritis, compared with values prior to induction of osteoarthritis. There was correlation between the gene expression profile in WBCs, cartilage, and synovium and the cartilage turnover proteins. Gene expression of ADAMDEC1, hUNC-93A, and RRM2 in WBCs were correlated when measured via microarray analysis and PCR assay.
Conclusions and Clinical Relevance—Expression of ADAMDEC1, GRP94, HCST, hUNC-93A, and RRM2 was differentially regulated in peripheral WBCs obtained from horses with experimentally induced osteoarthritis. Gene expression of ADAMDEC1, hUNC-93A, and RRM2 in peripheral WBCs has the potential for use as a diagnostic aid for osteoarthritis in horses.
Objective—To assess clinical, biochemical, and histologic effects of polysulfated glycosaminoglycan (PSGAG) or sodium hyaluronan administered intra-articularly in treatment of horses with experimentally induced osteoarthritis.
Procedures—Osteoarthritis was induced arthroscopically in 1 middle carpal joint of all horses. Eight horses received hyaluronan (20 mg) and amikacin (125 mg) intra-articularly on study days 14, 21, and 28. Eight horses received PSGAG (250 mg) and amikacin (125 mg) intra-articularly on study days 14, 21, and 28. Eight control horses received 2 mL of saline (0.9% NaCl) solution and amikacin (125 mg) intra-articularly on study days 14, 21, and 28. Clinical, radiographic, synovial fluid analysis, gross, histologic, histochemical, and biochemical findings were evaluated.
Results—No adverse treatment-related events were detected. Induced osteoarthritis caused a substantial change in lameness, response to flexion, joint effusion, and radiographic findings, and of these, synovial fluid effusion was reduced with PSGAG, compared with control horses. No changes in clinical signs were seen with PSGAG or hyaluronan, compared with control horses. Histologically, the degree of synovial membrane vascularity and subintimal fibrosis was significantly reduced with PSGAG treatment, compared with controls. Histologically, significantly less fibrillation was seen with hyaluronan treatment, compared with controls.
Conclusions and Clinical Relevance—Results indicated that PSGAG and hyaluronan had beneficial disease-modifying effects and are viable therapeutic options for osteoarthritis in horses.
Objective—To assess clinical, radiographic, histologic, and biochemical effects of sodium pentosan polysulfate (NaPPS) administered IM for treatment of experimentally induced osteoarthritis in horses.
Procedures—Osteoarthritis was induced arthroscopically in 1 middle carpal joint of all horses. Nine horses received NaPPS (3 mg/kg, IM) on study days 15, 22, 29, and 36. Nine control horses received the same volume of saline (0.9% NaCl) solution IM on study days 15, 22, 29, and 36. Clinical, radiographic, gross, histologic, histochemical, and biochemical findings as well as findings of synovial fluid analysis were evaluated.
Results—No adverse treatment-related events were detected. Induced osteoarthritis caused a substantial increase in lameness, response to flexion, joint effusion, radiographic findings, synovial membrane inflammation, and articular cartilage fibrillation. Articular cartilage fibrillation was substantially reduced by NaPPS treatment, and concentrations of chondroitin sulfate 846 epitope were significantly increased in the synovial fluid of osteoarthritic and nonosteoarthritic joints of treated horses.
Conclusions and Clinical Relevance—Results indicated that NaPPS has some beneficial disease-modifying effects and may be a therapeutic option for osteoarthritis in horses.
OBJECTIVE To evaluate the efficacy of IV administration of a product containing hyaluronan, sodium chondroitin sulfate, and N-acetyl-d-glucosamine for prevention or treatment of osteoarthritis in horses.
ANIMALS 32 healthy 2- to 5-year-old horses.
PROCEDURES The study involved 2 portions. To evaluate prophylactic efficacy of the test product, horses received 5 mL of the product (n = 8) or saline (0.9% NaCl) solution (8; placebo) IV every fifth day, starting on day 0 (when osteoarthritis was induced in the middle carpal joint of 1 forelimb) and ending on day 70. To evaluate treatment efficacy, horses received either the product or placebo (n = 8/treatment) on days 16, 23, 30, 37, and 44 after osteoarthritis induction. Clinical, diagnostic imaging, synovial fluid, gross anatomic, and histologic evaluations and other tests were performed. Results of each study portion were compared between treatment groups.
RESULTS Limb flexion and radiographic findings were significantly worse for horses that received the test product in the prophylactic efficacy portion than for placebo-treated horses or product-treated horses in the treatment efficacy portion. In the prophylactic efficacy portion, significantly less articular cartilage erosion was identified in product-treated versus placebo-treated horses. In the treatment efficacy portion, joints of product-treated horses had a greater degree of bone edema identified via MRI than did joints of placebo-treated horses but fewer microscopic articular cartilage abnormalities.
CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that caution should be used when administering the evaluated product IV to horses, particularly when administering it prophylactically, as it may have no benefit or may even cause harm.
Objective—To evaluate effects of extracorporeal shock wave therapy (ESWT) and polysulfated glycosaminoglycan treatment (PSGAGT) on subchondral bone (SCB), serum biomarkers, and synovial fluid biomarkers in horses with induced osteoarthritis.
Animals—24 healthy 2- to 3-year-old horses.
Procedures—An osteochondral fragment was created on the distal aspect of the radial carpal bone in 1 middle carpal joint of each horse. Horses were randomly allocated to receive local application of ESWT (days 14 and 28; n = 8), PSGAGT (IM, q 4 d for 28 days; 8), or a sham ESWT probe (placebo; days 14 and 28; 8). Serum biomarkers were measured every 7 days, and synovial fluid biomarkers were measured every 14 days. Bone density was measured by use of computed tomography on days 0 and 70, and microdamage and bone formation variables were compared among groups at the end of the study (day 70).
Results—There was no significant effect of ESWT or PSGAGT on any bone variable. Serum osteocalcin concentration was significantly greater in horses that received ESWT, compared with placebo-treated horses, and serum concentration of the C-terminal telopeptide of type I collagen was significantly higher in horses that received ESWT, compared with placebo- and PSGAG-treated horses. Concentrations of the synovial fluid epitope CS846 were significantly higher in joints with osteoarthritis treated with ESWT
Conclusions and Clinical Relevance—Treatment of osteoarthritis with ESWT had no effect on SCB but did induce increases in serum biomarkers indicative of bone remodeling. Treatment of osteoarthritis with PSGAG had no effect on SCB or biomarkers.
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
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)
Objective—To assess the clinical, biochemical, and histologic effects of intra-articular administration of autologous conditioned serum (ACS) in the treatment of experimentally induced osteoarthritis in horses.
Procedures—Osteoarthritis was induced arthroscopically in 1 middle carpal joint of all horses. In 8 placebo- and 8 ACS-treated horses, 6 mL of PBS solution or 6 mL of ACS was injected into the osteoarthritis-affected joint on days 14, 21, 28, and 35, respectively; PBS solution was administered in the other sham-operated joints. Evaluations included clinical assessment of lameness and synovial fluid analysis (performed biweekly); gross pathologic and histologic examinations of cartilage and synovial membrane samples were performed at necropsy.
Results—No adverse treatment-related events were detected. Horses that were treated with ACS had significant clinical improvement in lameness, unlike the placebo-treated horses. Among the osteoarthritis-affected joints, ACS treatment significantly decreased synovial membrane hyperplasia, compared with placebo-treated joints; although not significant, the ACS-treated joints also appeared to have less gross cartilage fibrillation and synovial membrane hemorrhage. The synovial fluid concentration of interleukin-1 receptor antagonist (assessed by use of mouse anti–interleukin-1 receptor antagonist antibody) was increased following treatment with ACS.
Conclusions and Clinical Relevance—Results of this controlled study indicated that there was significant clinical and histologic improvement in osteoarthritis-affected joints of horses following treatment with ACS, compared with placebo treatment. On the basis of these findings, further controlled clinical trials to assess this treatment are warranted, and investigation of the mechanisms of action of ACS should be pursued concurrently.