Current joint therapy usage in equine practice: a survey of veterinarians 2009.

REASONS FOR PERFORMING STUDY: Medications are frequently employed to treat intra-articular (IA) problems in the performance horse. Actual usage of the different IA medications in horses is not available. OBJECTIVES: To determine the most common usage of these medications, members of the American Association of Equine Practitioners (AAEP) were surveyed. METHODS: An email link to an online survey was electronically sent to 6305 AAEP members and the responses tabulated and analysed with a logistic regression model. RESULTS: A total of 831 survey responses were submitted and tabulated. Eighty per cent of the respondents indicated that they see 100% equine cases in their practice. The majority of respondents (77%) use triamcinolone acetonide (TA) to treat high motion joints and 73% use methylprednisolone acetate (MPA) to treat low motion joints. Veterinarians treating the Western performance and Sport horse were significantly more likely to use TA in high motion joints compared to MPA (P = 0.0201 and P<0.0001, respectively). Triamcinolone acetonide use compared to MPA in high motion joints by racehorse veterinarians was significantly lower compared to other veterinarians (P<0.0001). Polysulphated glycosaminoglycan (Adequan) and hyaluronate sodium (Legend) were the most commonly used disease modifying products (63 and 57% of respondents, respectively). Sport horse practitioners were significantly more likely than race or show horse veterinarians to utilise IRAP products (P = 0.0035 and P = 0.04, respectively). Respondents who had been in practice for more than 10 years were significantly less likely to use antimicrobials in their joint injections compared to those in practice for less than 10 years (P<0.0001). CONCLUSIONS: Significant differences existed in usage of medications related to primary discipline treated and years practicing. POTENTIAL RELEVANCE: The results of this study aid in defining the current usage of different joint therapy medications within equine practice. This knowledge can guide further research as well as education.

Effect of self-assembling peptide, chondrogenic factors, and bone marrow-derived stromal cells on osteochondral repair.

OBJECTIVE: The goal of this study was to test the ability of an injectable self-assembling peptide (KLD) hydrogel with or without chondrogenic factors (CF) and allogeneic bone marrow stromal cells (BMSCs) to stimulate cartilage regeneration in a full-thickness, critically-sized, rabbit cartilage defect model in vivo. We used CF treatments to test the hypotheses that CF would stimulate chondrogenesis and matrix production by cells migrating into acellular KLD (KLD+CF) or by BMSCs delivered in KLD (KLD+CF+BMSCs). DESIGN: Three groups were tested against contralateral untreated controls: KLD, KLD+CF, and KLD+CF+BMSCs, n=6-7. Transforming growth factor-ß1 (TGF-ß1), dexamethasone, and insulin-like growth factor-1 (IGF-1) were used as CF pre-mixed with KLD and BMSCs before injection. Evaluations included gross, histological, immunohistochemical and radiographic analyses. RESULTS: KLD without CF or BMSCs showed the greatest repair after 12 weeks with significantly higher Safranin-O, collagen II immunostaining, and cumulative histology scores than untreated contralateral controls. KLD+CF resulted in significantly higher aggrecan immunostaining than untreated contralateral controls. Including allogeneic BMSCs+CF markedly reduced the quality of repair and increased osteophyte formation compared to KLD-alone. CONCLUSIONS: These data show that KLD can fill full-thickness osteochondral defects in situ and improve cartilage repair as shown by Safranin-O, collagen II immunostaining, and cumulative histology. In this small animal model, the full-thickness critically-sized defect provided access to the marrow, similar in concept to abrasion arthroplasty or spongialization in large animal models, and suggests that combining KLD with these techniques may improve current practice.

Correlation of the anticholinesterase activity of a series of organophosphates with their ability to compete with agonist binding to muscarinic receptors.

Some compounds that inhibit acetylcholinesterase (AChE) activity compete directly with quinuclidinyl benzilate (QNB) binding, a muscarinic antagonist which binds to all subtypes equally, and with cis-methyldioxolane (CD), an agonist that binds with high affinity to the M2 subtype of muscarinic receptors. The relationship between inhibition of AChE activity and the capability to affect muscarinic receptors directly has not been systematically explored. The interaction of eight organophosphates with muscarinic receptors was compared to their ability to inhibit AChE activity in vitro in tissue homogenates from rat hippocampus and frontal cortex, two cholinergically enriched areas of the brain. Of the compounds tested only echothiophate competed for [3H]QNB binding and only at concentrations greater than 100 microM. The anticholinesterase compounds were also tested for their ability to compete with a muscarinic receptor agonist, [3H]CD, which binds with high affinity (approximate KD = 3.5 nM) to 10 and 3% of the muscarinic receptors in the frontal cortex and hippocampus, respectively. The anticholinesterase compounds inhibited high-affinity [3H]CD binding up to 80% and the effects were similar in both tissues. Echothiophate and DFP were potent inhibitors of [3H]CD binding, as were the active "oxon" forms of parathion, malathion, and disulfoton. The parent "thio" forms of these insecticides, however, were much less effective in competing for [3H]CD binding. A similar pattern of potency was observed for the inhibition of brain AChE activity. A strong correlation was found between the ability of a compound to inhibit AChE activity and the ability to compete with [3H]CD binding. These data suggest that the biological effects of cholinesterase-inhibiting compounds may be due to more than their ability to inhibit AChE.