Glycosaminoglycans (GAGs) are long unbranched polysaccharides consisting of repeating disaccharide units that are found in various tissues and fluids in horses. They are integral components of connective tissues, contributing to the structural integrity and function of cartilage, tendons, and synovial fluid. GAGs are involved in maintaining joint health and facilitating smooth movement by providing lubrication and shock absorption. Common types of glycosaminoglycans in horses include chondroitin sulfate, dermatan sulfate, and hyaluronic acid. Changes in GAG levels and composition can be indicative of joint disorders or degenerative conditions in horses. This page compiles peer-reviewed research studies and scholarly articles that explore the biochemical properties, physiological roles, and clinical implications of glycosaminoglycans in equine health.
Lauder RM, Huckerby TN, Nieduszynski IA.Fibromodulin has been isolated from bovine and equine articular cartilage and the attached keratan sulphate chains subjected to digestion by keratanase II. The oligosaccharides generated have been reduced and subsequently isolated by strong anion-exchange chromatography. Their structures have been determined by high-field 1H-NMR spectroscopy and high-pH anion-exchange chromatography. Both alpha(2-6)- and alpha(2-3)-linked N-acetylneuraminic acid have been found in the capping oligosaccharides, and, fucose which is alpha(1-3)-linked to N-acetylglucosamine has been found as a branch in both repe...
Fuller CJ, Barr AR, Dieppe PA, Sharif M.An epitope of keratan sulphate (KS) and total glycosaminoglycans (GAG) were measured in synovial fluid samples from joints of 53 horses immediately following humane destruction. Internal examination of the joints post mortem ensured that there was no gross evidence of osteoarthritis or other joint disease. Joints sampled were distal interphalangeal (DIP), proximal interphalangeal (PIP), metacarpophalangeal (MCP), metatarsophalangeal (MTP), tarsometatarsal (TMT), tarsocrural (TC), femoropatellar (FP) and antebrachiocarpal (ABC) joints. The age of each horse was assessed by examination of the te...
Caron JP, Kaneene JB, Miller R.To determine the patterns of use and perceived efficacy of polysulfated glycosaminoglycan (PSGAG) for the treatment of degenerative joint disease in horses. Methods: Cross-sectional mail survey. Methods: 1,522 equine practitioners. Methods: Information was obtained on frequency and route of administration of PSGAG for the treatment of each of 4 forms of degenerative joint disease, the efficacy of PSGAG, and its efficacy compared with that of sodium hyaluronate. Data were analyzed by nonparametric and multivariate regression methods. Results: Response rate was 40.5%. Of practitioners responding...
Dow SM, Wilson AM, Goodship AE.Horses with acute injuries of the superficial digital flexor tendon were treated with a course of seven intramuscular injections of 500 mg of polysulphated glycosaminoglycan at four-day intervals. Clinical assessments of the lesions were made by a veterinary surgeon at the time of each injection and 14 and 28 days after the last injection. A total of 150 courses of the drug were administered and adequately completed assessment forms were returned for 80 cases. Long-term follow-up data were obtained for 19 cases. The subjective assessments by the veterinary surgeons showed that in 80 per cent o...
Kawcak CE, Trotter GW, Frisbie DD, McIlwraith CW.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. Methods: Articular cartilage from a 3-year-old, mixed breed horse euthanatized for reasons other than musculoskeletal disease or sepsis. Methods: 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 ...
Todhunter RJ, Fubini SL, Wootton JA, Lust G.The effect of different doses of methylprednisolone acetate (MPA) on proteoglycan and collagen metabolism of articular cartilage from normal equine joints was tested in vitro. Methods: Cultured explants were treated with 0, 0.0004, 0.004, 0.04, 0.4 and 4.0 mg/ml (approximately 10(-6)-10(-2) M) MPA for 72 h. Proteoglycan synthesis was measured by incorporation of sodium [35S]sulfate into proteoglycans and proteoglycan degradation was measured by release of total and radiolabeled proteoglycan into the culture media. The size of the proteoglycans was assessed with size exclusion chromatography un...
Klohnen A, Wilson DG, Hendrickson DA, Cooley AJ, MacWilliams PS.To evaluate the bactericidal properties of chlorhexidine diacetate (CHD) after potentiation with EDTA and Tris buffer (EDTA-Tris), and to find a potentiated CHD concentration that would achieve 90 to 100% killing for all bacteria tested. Methods: 6 adult ponies. Methods: Serial dilutions of CHD, CHD in EDTA-Tris and EDTA-Tris alone were evaluated for bactericidal activity against Staphylococcus aureus, Escherichia coli, and Streptococcus zooepidemicus. The tarsocrural joints of 6 ponies were lavaged with either 1 L phosphate-buffered saline solution (control) or 1 L of 0.0005% CHD in EDTA-Tris...
Loredo GA, MacDonald MH, Benton HP.To investigate whether recombinant human bone morphogenetic protein-2 (rhBMP-2) regulates glycosaminoglycan (GAG) synthesis and release from equine articular cartilage explant cultures. Methods: Equine articular cartilage explants were maintained in vitro for 7 days in the presence of 0 (control), 1, 10, or 100 ng of rhBMP-2/ml. Synthesis and release of GAG were assessed as measures of production and degradation of the extracellular matrix, respectively. Methods: 6 horses (age range, 2 to 25 years old) without clinically detectable musculoskeletal abnormalities. Methods: Rate of synthesis of G...
Pullin JG, Collier MA, Das P, Smith RL, DeBault LE, Johnson LL, Walls RC.Comparison of perilesional cartilage, lesional repair tissue, and subchondral bone activity 6 months after application of holmium-yttrium-aluminum-garnet (Ho:YAG) laser energy to chronic (10 week) induced 10-mm full-thickness (FT) circular articular cartilage craters followed by 6 months' intermittent active motion (IAM) in a free exercise environment was investigated. The 2.1-microns wavelength was delivered in hand-controlled near-contact mode by arthroscopic surgery in a saline medium. Bilateral arthroscopy was performed on normal antebrachiocarpal, intercarpal, and metacarpophalangeal join...
Miles CA, Fursey GA, Birch HL, Young RD.The velocity, attenuation and apparent backscattering coefficient of 6-11-MHz ultrasound were measured in three orthogonal directions in equine deep digital flexor (DDF) and superficial digital flexor (SDF) tendons at 0 degree C. Ultrasonic measurements were examined for correlation with tendon water, collagen, DNA and glycosaminoglycans contents, determined by chemical analyses and with structure observed by scanning electron microscopy. The SDF tendon contained more water, more DNA (i.e., more cells), less collagen and less glycosaminoglycans and exhibited lower velocities and attenuations t...
Gaustad G, Larsen S.A randomised double blind and placebo controlled clinical study was carried out. Standardbred trotters (n=77), age 3-4 years) with moderate to severe lameness were grouped according to number of affected joints and, within each group, were randomised for treatment with polysulphated glycosaminoglycan (PSGAG), sodium hyaluronate (SH) or placebo for 3 weeks. The horses were inspected weekly with a final examination 2-4 weeks after the end of treatment. Mean initial lameness score was significantly reduced during treatment and at the last examination in all 3 groups (P<0.01). Additionally, the...
Palmer JL, Bertone AL, McClain H.A modification of a colorimetric assay was used to determine synovial fluid total and individual sulphated-glycosaminoglycan concentration in various clinical presentations of joint disease in horses. Concentrations of synovial fluid and serum sulphated-glycosaminoglycan (GAG) were measured by the 1,9-dimethylmethylene blue (DMMB) dye assay in normal horses (n = 49), horses with acute (n = 26) or chronic (n = 27) joint disease (defined by clinical, radiographic, and clinicopathological parameters), and horses with cartilaginous lesions at diagnostic arthroscopy, but with normal radiographs and...
Sams AE, Minor RR, Wootton JA, Mohammed H, Nixon AJ.Chondrocyte-laden collagen scaffolds were evaluated in extensive cartilage defects in an equine model. Arthroscopic techniques were used to implant a chondrocyte-collagen culture product in 15-mm defects in the lateral trochlear ridge of the femoropatellar joint of 12 horses. Ungrafted control defects were formed in the opposite joint. Groups of six horses were terminated at 4 and 8 months after implantation and the repair sites, adjacent cartilage, and remote cartilage within each femoropatellar joint examined biochemically. Eight months following surgery the relative proportions of type II c...
MacDonald MH, Stover SM, Willits NH, Benton HP.The metabolic responses of equine articular cartilage to incubation with bacterial lipopolysaccharide (LPS) were studied, using explant cultures of articular cartilage obtained from the metatarsophalangeal joints of 15 horses, age of which ranged from 3 months to 20 years. For comparison, explants were also established from the metatarsophalangeal joints of 3 calves. Explants were cultured for 3 days in medium containing various concentrations of LPS from 0 (control) to 100 micrograms/ml. Glycosaminoglycan (GAG) released during the 3-day incubation was determined by a spectrophotometric assay,...
Hendrickson DA, Nixon AJ, Grande DA, Todhunter RJ, Minor RM, Erb H, Lust G.Cartilage resurfacing by chondrocyte implantation, with fibrin used as a vehicle, was examined in large (12 mm) full-thickness articular cartilage defects in horses. Articular chondrocytes, isolated from a 9-day-old foal, were mixed with fibrinogen and injected with thrombin, in a 1:1 mixture, into 12 mm circular defects on the lateral trochlea of the distal femur of eight normal horses. The contralateral femoropatellar (knee) joint served as a control in which the defect was left empty. Synovial fluid from the femoropatellar joints was sampled on days 0, 4, 7, 30, 120, and 240 postoperatively...
Hendrickson DA, Nixon AJ, Erb HN, Lust G.Equine neonatal chondrocytes were cultured in three-dimensional fibrin matrices under conditions of immediate implantation or implantation following monolayer culture for 6 days, and 3 cell concentrations (1 x 10(5), 1 x 10(6), and 5 x 10(6) chondrocytes/cm3). Equine fibrinogen was collected by cryoprecipitation and polymerized by use of activated bovine thrombin. The fibrin implants were harvested and analyzed histologically and biochemically at 3, 7, and 14 days after the chondrocytes were implanted in fibrin. The differentiation ratio (ratio of rounded, chondrocyte-like cells to stellate, f...
Hokke CH, Roosenboom MJ, Thomas-Oates JE, Kamerling JP, Vliegenthart JF.The disialylated poly-(N-acetyllactosamine)-containing O-linked oligosaccharide alditols, released by alkaline borohydride treatment of the enzymically N-deglycosylated beta-subunit of equine chorionic gonadotropin, were purified by fast protein liquid chromatography (FPLC) on Mono Q and analysed by fast ion bombardment mass spectrometry (FAB-MS) and 1H-NMR spectroscopy. The identified oligosaccharide alditols have the following structure: [Formula: see text]
Pilling A, Davison AJ, Telford EA, Meredith DM.Glycoprotein 45 is a major envelope glycoprotein of equine herpesvirus type 1. The gene encoding this protein is located between map units 0.615 and 0.636 on the virus genome and evidence has suggested that it is encoded by gene 52, one of four genes within this region. Using PCR we have amplified gene 52 and subsequently cloned it into a mammalian expression vector under the control of the human cytomegalovirus immediate early gene promoter. The gene was expressed in COS-7 cells and its product was detected by immunofluorescence and Western blotting. The results indicate that glycoprotein 45 ...
Barr AR, Duance VC, Wotton SF, Waterman AE.The influence of repeated intra-articular injections of sodium hyaluronate and polysulphated glycosaminoglycan on the repair of full-thickness osteochondral defects was examined in the midcarpal joints of ponies. The study showed no significant difference between treated and control groups with regard to total collagen content, uronic acid content or the relative proportions of Type I and Type II collagen in the repair tissue, indicating that the drugs did not affect the biochemical composition of the repair tissue 11 weeks after defect induction.
Todhunter RJ, Minor RR, Wootton JA, Krook L, Burton-Wurster N, Lust G.Our aim was to determine if mild to moderate postoperative exercise and intra-articular polysulfated glycosaminoglycan result in improved repair of large, experimentally induced osteochondral defects in a weight-bearing surface of equine joints. Arthroscopic debridement was used to produce full-thickness defects in a weight-bearing area of the radial carpal bones in 18 ponies. The ponies were randomly assigned to two groups balanced for age: nine animals in the exercise and nine in the no exercise group. Six ponies in each group were medicated weekly for 5 weeks with an intra-articular injecti...
Fubini SL, Boatwright CE, Todhunter RJ, Lust G.Intra-articularly administered, long-acting corticosteroids are a beneficial treatment for many equine joint disorders because they alleviate inflammation and signs of pain, but they also exert detrimental effects on the biochemical composition and morphologic features of articular cartilage. Chondroprotective drugs have been shown to mitigate some of the deleterious effects of intra-articularly administered corticosteroids on articular cartilage of laboratory animals. Twenty-one ponies were assigned at random to receive 1 of 3 treatments in the right middle carpal joint. Group-1 ponies (n = 8...
Todhunter RJ, Altman NS, Kallfelz FA, Nersesian P, Lust G.Combined blood pool and delayed images produced by use of 99mTc-methylene diphosphonate (99mTcMDP) were evaluated as an objective measurement of the response of equine joints with osteochondral defects to postoperative exercise and intra-articularly administered polysulfated glycosaminoglycan (PSGAG). Osteochondral defects (approx 2.4 x 0.9 cm) were induced arthroscopically in the dorsodistal radial carpal bones of 18 ponies. These ponies were randomized (while balancing for age [range 2 to 15; median, 5.0; mean, 5.1 years]) to 2 treatment groups. Nine ponies were assigned to be exercised, and...
Todhunter RJ, Yeager AE, Freeman KP, Parente EJ, Lust G.Keratan sulfate (KS) is a glycosaminoglycan, distribution of which is confined mostly to hyaline cartilage. As such, it is a putative marker of hyaline cartilage catabolism. In experiment 1, a focal osteochondral defect was made arthroscopically in 1 radial carpal bone of 2 ponies, and in 2 other ponies, chymopapain was injected into the radiocarpal joint to induce cartilage catabolism. Sequential and concurrent plasma and synovial fluid concentrations of KS were measured, up to 13 months after induction of cartilage injury, to determine whether changes in KS concentrations reflected cartilage...
Caron JP, Toppin DS, Block JA.Middle carpal cartilage explants from 4 horses with mild osteoarthritis involving that joint were maintained in tissue culture to test the effects of a polysulfated glycosaminoglycan (PSGAG) on proteoglycan synthesis and degradation. Cultures were exposed to 0.025 or 25 mg of PSGAG/ml for 48 hours, after which the medium was replaced with medium containing similar doses of PSGAG and 35S. Subsequently, the sulfated proteoglycan content of the medium and extracts of the explants was measured. Gel filtration chromatography was used to estimate the size and to purify the principal, large proteogly...
Marr CM, Love S, Boyd JS, McKellar Q.Ultrasonographic examination was used to define the severity of injuries to the superficial digital flexor tendon in 73 National Hunt or point-to-point racehorses and the factors influencing the outcome of the cases were examined. Thirty-four of the horses (46 per cent) returned to work with an average time out of training of 13.5 months. The rate of recurrence of the injury was 35 per cent. The severity of the lesions was related to the outcome; all the mildly affected horses returned to work, with 63 per cent of them racing and an average time out of training of 10.2 months; 50 per cent of t...
Oikawa M, Katayama Y, Yoshihara T, Kaneko M, Yoshikawa T.The morphology of the arteries in the uterine wall was studied in three multiparous aged mares that had suffered repeated pregnancy failure. The uterine wall arteries exhibited elastosis of the intima or adventitia, or both, resembling "physiological pregnancy sclerosis". In areas affected by elastosis, degeneration of the pre-existing elastic fibres and increased glycosaminoglycans were frequently observed. Newly formed elastic fibres were not evident. Delayed resorption due to disordered metabolic turnover of the elastin was thought to be an important factor in the pathogenesis of the arteri...
Richardson DW, Clark CC.Hexosamine concentration (an index of proteoglycan content), DNA content (an index of cellularity), and [35S]sulfate incorporation (an index of proteoglycan synthesis) of articular cartilage were measured in biopsy specimens from medial proximal sesamoid bone, medial condyle of the third metacarpal bone, and proximal dorsal rim of the proximal phalanx in both metacarpophalangeal joints of 6 adult horses. One limb was then placed in a fiberglass cast that extended down from the proximal portion of the metacarpus and enclosed the hoof; the other limb was not casted. After 30 days of stall confin...
MacDonald MH, Stover SM, Willits NH, Benton HP.Explant cultures were set up, using articular cartilage obtained from metatarsophalangeal joints of 11 horses. Explants from 2 horses were used to determine culture conditions appropriate for tissue viability. The cartilage explants maintained steady-state metabolism of proteoglycans during a 13-day evaluation period. The metabolic response of equine articular cartilage to incubation with recombinant human interleukin 1 (0.01 to 100 ng/ml) was studied, using cartilage obtained from the remaining 9 horses, age of which ranged from 3 months to 20 years. Interleukin 1 induced a dose-dependent rel...
Lapointe JM, Laverty S, Lavoie JP.Case histories, results of synovial fluid analyses, treatment regimens and outcome are described for 15 adult Standardbred horses with confirmed post-injection septic arthritis. Joint sepsis followed injection of corticosteroids, hyaluronic acid, polysulphated glycosaminoglycan, or local anaesthetic. The median interval from injection to appearance of clinical signs was 2.5 days, and median interval from injection to referral was 9 days. The median initial synovial leucocyte count on admission was 57 x 10(9)/litre, but there was a wide range of values (18-258 x 10(9)/litre). The median synovia...
Vachon AM, McIlwraith CW, Powers BE, McFadden PR, Amiel D.Using biodegradable pins, sternal cartilage autografts were fixed into osteochondral defects of the distal radial carpal bone in ten 2 to 3-year-old horses. The defects measured 1 cm2 at the surface and were 4 mm deep. Control osteochondral defects of contralateral carpi were not grafted. After confinement for 7 weeks, horses were walked 1 hour daily on a walker for an additional 9 weeks. Horses were euthanatized at 16 weeks. Half of the repair tissue was processed for histologic and histochemical (H&E and safranin-O fast green) examinations. The other half was used for the following bioch...
Frisbie DD, Sandler EA, Trotter GW, McIlwraith CW.To determine response of interleukin-1alpha (IL-1alpha)-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. Methods: Effects of IGF-1 (0 to 500 ng/ml) after addition of IL-1alpha 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. Res...
Gurusinghe S, Hilbert B, Trope G, Wang L, Bandara N, Strappe P.Immortalization of chondrocytes enables long term in vitro culture; however, the chondrogenic capacity of transformed cells varies, thus highlighting the need to develop a proliferative and tuneable chondrocyte cell line where hypertrophic differentiation can be controlled. In this study the SV40 large T antigen and human telomerase reverse transcriptase were employed to immortalize pooled equine chondrocytes through lentiviral vector mediated transduction either singly or on combination. Transformed chondrocytes proliferated stably over multiple passages, but resulted in significantly lower e...
Gnanesh Kumar BS, Rawal A.Secretory immunoglobulin A (sIgA) is the major antibody present in the human milk where it confers passive immunity to neonates. Other than human, non-ruminants such as equine, swine etc., also possess sIgA in milk but detailed characterization is limited. In the present study, we characterized sIgA from donkey milk for amino acid sequence and N-glycosylation through LC-MS/MS analysis. The complete amino acid sequence of alpha chain constant region (C) was elucidated. The sequence analysis of variable regions (V and V) and light chain constant region (C) showed several amino acid substitutions...
Jones CJ, Enders AC, Wooding FP, Dantzer V, Leiser R, Stoddart RW.Using lectin histochemistry on plastic-embedded material, the glycosylation patterns of equine girdle and cup cells, and associated endometrial glands, have been investigated from 37 to 67 days gestation. Results were compared with the glycosylation of the 50-day allantochorionic trophoblast of the established equine placenta that will later form the microcotyledons. The differentiated cup cells, which secrete equine chorionic gonadotropin (eCG), showed a pattern of glycosylation that was distinct both from the progenitor girdle cells and the allantochorionic trophoblast, with granules that bo...
Du J, Eddington N.A sensitive and selective HPLC method for the determination of the disaccharides of chondroitin sulfate in horse and dog plasma was validated. Chondroitin sulfate is degraded by chondroitinase ABC to three primary unsaturated disaccharides, (1) 2-acetamido-2-deoxy-3-O-(beta-D-gluco-4-enepyranosyluronic acid)-D-galactose, (2) 2-acetamido-2-deoxy-3-O-(beta-D-gluco-4-enepyranosyluronic acid)-4-O-sulfo-D-galactose, and (3) 2-acetamido-2-deoxy-3-O-(beta-D-gluco-4-enepyranosyluronic acid)-6-O-sulfo-D-galactose, when treated with chondroitinase. Plasma samples (0.5 ml) were treated with 50 mU of chon...
Sandler EA, Frisbie DD, McIlwraith CW.Previous in vitro pilot studies have defined a potentially beneficial effect of insulin-like growth factor-1 (IGF-1) and triamcinolone acetonide (TA) on interleukin-1 (IL-1)-conditioned equine cartilage. Furthermore, an optimal dose for IGF-1 treatment alone has been documented previously using the same test system as in the current project. Objective: To perform a dose titration of TA on IL-1-conditioned equine articular cartilage explants in the presence of an optimised IGF-1 dose, in order to optimise a triamcinolone concentration for use in combination with IGF-1 for future investigations....
McCarthy MB, Duesterdieck-Zellmer KF, Larson MK.To determine whether Botulinum neurotoxin type A (BoNT-A) ameliorates the effects of interleukin 1 (IL-1) on equine articular cartilage, or exerts negative effects on normal equine articular cartilage homeostasis in vitro. Methods: Articular cartilage explants from 6 healthy femoropatellar joints of 3 adult horses. Methods: Explants were allocated to the IL-1 challenged or unchallenged group, then exposed to 1 of 6 concentrations of BoNT-A (0, 1, 10, 50, 100, or 500 pg/mL) for 96 hours. To assess BoNT-A's effects on inflammation, prostaglandin E2 (PGE2) was measured in media via ELISA. Matrix ...
Richardson DW, Loinaz R.There is an enormous volume of published material about most of the agents used to treat or prevent arthritis in horses. Unfortunately, most of the claims made by nearly all purveyors of arthritis medications in such media are largely unsubstantiated. In addition, the quality of the available information is highly inconsistent, making evidence-based recommendations difficult. This article concentrates on injectable polysulfated glycosaminoglycan, injectable hyaluronan, and the common oral "nutraceuticals".
Collins EA.Four cases of equine lameness were treated with intra-articular polysulphated glycosaminoglycan. Two, two-year-old flat racers were treated conservatively after traumatic injury. They subsequently became lame owing to the formation of new bone and osteophytes. Two older steeplechasers were lame owing to degenerative joint disease. The four horses were treated with intra-articular injections of polysulphated glycosaminoglycans and, after three or four injections, they became clinically sound and were able to continue racing with varying degrees of success.
Fuller CJ, Barr AR, Dieppe PA, Sharif M.An epitope of keratan sulphate (KS) and total glycosaminoglycans (GAG) were measured in synovial fluid samples from joints of 53 horses immediately following humane destruction. Internal examination of the joints post mortem ensured that there was no gross evidence of osteoarthritis or other joint disease. Joints sampled were distal interphalangeal (DIP), proximal interphalangeal (PIP), metacarpophalangeal (MCP), metatarsophalangeal (MTP), tarsometatarsal (TMT), tarsocrural (TC), femoropatellar (FP) and antebrachiocarpal (ABC) joints. The age of each horse was assessed by examination of the te...
Oikawa M, Kaneko M, Yoshikawa T.To elucidate the pathomorphogenesis of extremely shortened small-intestinal villi, occurring spontaneously in neonatal foals, the morphology of the small intestine with stunted villi was studied in eight cases. All intestinal wall elements and the villi were poorly developed. Most villi were found to be extremely short throughout the entire length of the small intestine. The villous core consisted of undifferentiated, fibroblast-like cells held loosely together by ground substance which was rich in glycosaminoglycan. Development of the villous lamina propria was poor with respect to capillarie...
Whyte A, Allen WR.Pre- and post-implantation endometrial tissue was removed from equids at known stages of pregnancy. Thin sections of this material were reacted with fluorescein conjugates of several lectins. Two lectins in particular, with specificities for L-fucose and N-acetylglucosamine, reacted strongly with the endometrial epithelium. The reaction for N-acetylglucosamine occurred in small patches on the endometrial epithelium and extended to cover the entire epithelial surface and endometrial glands after implantation. L-Fucose was observed in larger surface deposits particularly at the openings of endom...
Nixon AJ, Krook LP, Roth JE, King JM.A pulsed carbon dioxide laser was used to vaporize articular cartilage in four horses, and perforate the cartilage and subchondral bone in four horses. Both intercarpal joints were examined arthroscopically and either a 1 cm cartilage crater or a series of holes was created in the third carpal bone of one joint. The contralateral carpus served as a control. After euthanasia at week 8, the treated and control joints were examined for gross changes, and samples of cartilage and subchondral bone, synovial membrane, and peripheral lymph nodes were examined histologically. Depletion of cartilage ma...
MacDonald MH, Benton HP.To determine the influence of activated equine neutrophils on sulfated glycosaminoglycan metabolism of equine articular cartilage in vitro. Methods: Articular cartilage explants harvested from the metacarpophalangeal joints of 7 horses. Methods: Proteoglycan degradation and synthesis were measured by release of glycosaminoglycan from the explants, and incorporation of [35S]sulfate into newly synthesized glycosaminoglycan. Results: Activated equine neutrophils significantly increased the release of glycosaminoglycan from explant matrix and the magnitude of that response was influenced by durati...
Brama PA, Barneveld A, Karssenberg D, Van Kampen GP, van Weeren PR.A recently developed indenter system that aims at determination of local structural properties of the cartilage surface was evaluated for suitability in the horse. To this aim, maximum indenter force was measured of the articular surface and related to biochemical characteristics of the cartilage at different sites of the distal metacarpal bone (MC). Significant topographical variation exists in structural properties of the articular surface of the MC. The dorsal margin showed a significantly lower maximum indenter force than more centrally located areas, indicating an increased compliance und...
Barr AR, Duance VC, Wotton SF, Waterman AE.The influence of repeated intra-articular injections of sodium hyaluronate and polysulphated glycosaminoglycan on the repair of full-thickness osteochondral defects was examined in the midcarpal joints of ponies. The study showed no significant difference between treated and control groups with regard to total collagen content, uronic acid content or the relative proportions of Type I and Type II collagen in the repair tissue, indicating that the drugs did not affect the biochemical composition of the repair tissue 11 weeks after defect induction.
Okumura M, Fujinaga T.The role of keratan sulphate (KS) as a metabolic marker of cartilage was evaluated using an in vitro model of equine articular cartilage. Articular cartilage was harvested from clinically healthy 6-month-old foals (n = 3). Chondrocytes were centrifuged and cultured as pellets. Chondrocyte pellets were stimulated by insulin-like growth factor-I alpha (IGF-I alpha) or interleukin-1 alpha (IL-1 alpha) for 2 weeks. The concentrations of sulphated glycosaminoglycans (GAG) and KS in the culture media were measured by a 1,9-dimethyl-methylene blue (DMMB) colorimetric assay and an inhibition enzyme-li...
Lettry V, Kawasaki H, Sugaya K, Hosoya K, Takagi S, Okumura M.This study aimed to evaluate a system that identifies cartilage turn over and/or degradation through measurement of a new keratan sulfate (KS) epitope concentration in equine sera. Blood samples were collected from 30 horses, 1 (n = 15) and 2 year-olds (n = 15). Serum samples were analyzed for an epitope of keratan sulfate by 1/20/5D4 (KS5D4) and new epitopes of keratan sulfate using high sensitive keratan sulfate (HSKS), measured by two respective enzyme-linked immunosorbant assays (ELISAs). There was no correlation in serum concentration of KS evaluated using 5D4 and HSKS. Age had no signifi...
Khatibzadeh SM, Menarim BC, Nichols AE, Werre SR, Dahlgren LA.Extracellular matrix (ECM) is responsible for tendon strength and elasticity. Healed tendon ECM lacks structural integrity, leading to reinjury. Porcine urinary bladder matrix (UBM) provides a scaffold and source of bioactive proteins to improve tissue healing, but has received limited attention for treating tendon injuries. The objective of this study was to evaluate the ability of UBM to induce matrix organization and tenogenesis using a novel in vitro model. We hypothesized that addition of UBM to tendon ECM hydrogels would improve matrix organization and cell differentiation. Hydrogels see...
Warnock JJ, Fox DB, Stoker AM, Beatty M, Cockrell M, Janicek JC, Cook JL.Introduction. Tissue engineering is a new methodology for addressing meniscal injury or loss. Synovium may be an ideal source of cells for in vitro meniscal fibrocartilage formation, however, favorable in vitro culture conditions for synovium must be established in order to achieve this goal. The objective of this study was to determine cellularity, cell distribution, and extracellular matrix (ECM) formation of equine fibroblast-like synoviocytes (FLS) cultured on synthetic scaffolds, for potential application in synovium-based meniscal tissue engineering. Scaffolds included open-cell poly-L-l...
van der Harst MR, DeGroot J, Kiers GH, Brama PA, van de Lest CH, van Weeren PR.To assess whether site-related changes in biochemical composition are present in the cartilage and subchondral and trabecular bone of the metacarpophalangeal joint of horses with early osteoarthritis. Methods: Right metacarpophalangeal joints from 59 mature warmblood horses. Methods: Biochemical data (cross-link, amino acid, DNA, and ash contents; denatured collagen and glycosaminoglycan [GAG] concentrations; bone mineral density; and mineral composition) were obtained from 2 differently loaded sites of phalanx I cartilage and subchondral and trabecular bone samples; data were compared with pr...
Verde C, Ferrante M, Simpson MI, Babusci M, Broglia G, Landoni MF.Twelve healthy horses were subject to the monoioidoacetate (MIA) carpitis model, which was allowed to develop for 7 days. The horses were then randomly divided into two groups. Group A (control) received an intramuscular injection of normal saline every 4 days for a total of seven injections while group B received 500 mg of a PSGAG (SYNTEX CSY36) intramuscularly every 4 days for seven treatments. Efficacy of the PSGAG was evaluated by three clinical outcomes: lameness score, carpal circumference and maximum carpal flexion. Clinical outcomes were measured on days -8 (previous to carpitis induct...
Broeckx S, Zimmerman M, Crocetti S, Suls M, Mariën T, Ferguson SJ, Chiers K, Duchateau L, Franco-Obregón A, Wuertz K, Spaas JH.Degenerative joint disease (DJD) is a major cause of reduced athletic function and retirement in equine performers. For this reason, regenerative therapies for DJD have gained increasing interest. Platelet-rich plasma (PRP) and mesenchymal stem cells (MSCs) were isolated from a 6-year-old donor horse. MSCs were either used in their native state or after chondrogenic induction. In an initial study, 20 horses with naturally occurring DJD in the fetlock joint were divided in 4 groups and injected with the following: 1) PRP; 2) MSCs; 3) MSCs and PRP; or 4) chondrogenic induced MSCs and PRP. The ho...
Oke SL, Hurtig MB, Keates RA, Wright JR.To develop a new 1,9-dimethylmethylene blue (DMMB) assay for measurement of sulfated glycosaminoglycan (sGAG) concentrations in equine synovial fluid (SF) by use of membrane technology and to compare the assay's ability to measure sGAG concentrations with that of 2 other established DMMB assays. Methods: 25 samples of SF collected from affected joints of 14 horses and 13 samples of SF collected from nonaffected (control) joints of 4 horses. Methods: A solid-phase DMMB assay was developed to measure sGAG concentrations in SE Results for the assay were then compared with results obtained by use ...
McIlwraith CW, Van Sickle DC.Arthritis was experimentally induced in the intercarpal joints of a series of mature ponies by the intraarticular injections of 400 microgram of the polyene antibiotic filipin in 1 ml of dimethyl sulfoxide. Twelve consecutive weekly injections were administered and the ponies were euthanatized 4 weeks after the last injection of filipin was made. The ponies were exercised for 1 hour each day throughout the experiment. Articular cartilage specimens from 4 sites in each intercarpal joint were examined histologically and histo-chemically. For the histochemical examination, safranin O-fast green, ...
Pearson W, Orth MW, Lindinger MI.To evaluate inflammatory responses induced via intra-articular recombinant human interleukin (IL)-1beta treatment in horses receiving a dietary nutraceutical (DN; composed of mussel, shark cartilage, abalone, and Biota orientalis lipid extract) and assess the clinical effects of long-term DN administration. Methods: 22 healthy horses. Methods: 12 horses were fed 0, 15, 45, or 75 mg of DN (3 horses/treatment) daily for 84 days. General health and clinicopathologic variables were monitored at intervals. Ten other horses received 0 or 15 g of DN/d (5 horses/treatment) for 29 days (beginning day -...
Kawcak CE, Frisbie DD, McIlwraith CW, Werpy NM, Park RD.To evaluate the use of a combination of avocado and soybean unsaponifiable (ASU) extracts for the treatment of experimentally induced osteoarthritis in horses. Methods: 16 horses. Methods: Osteoarthritis was induced via osteochondral fragmentation in 1 middle carpal joint of each horse; the other joint underwent a sham operation. Horses were randomly allocated to receive oral treatment with ASU extracts (1:2 [avocado-to-soybean] ratio mixed in 6 mL of molasses; n = 8) or molasses (6 mL) alone (placebo treatment; 8) once daily from days 0 to 70. Lameness, response to joint flexion, synovial eff...
Gustafson SB, McIlwraith CW, Jones RL, Dixon-White HE.Polysulfated glycosaminoglycan (PSGAG) recently have been reported to potentiate the infectivity of Staphylococcus aureus in horses with experimentally induced septic arthritis. Four groups of 8 horses each had 1 midcarpal joint injected with approximately 33 viable colony-forming units (CFU) of S aureus plus either 1 ml of saline solution (group 1), 250 mg of PSGAG (group 2), 250 mg of PSGAG passed through a 0.6-microns filter (group 3), or 250 mg of PSGAG plus 125 mg of amikacin (group 4). Horses that developed clinical signs consistent with sepsis were euthanatized, and samples were collect...
