Sleep Pattern Interference in the Cognitive Performance of Lusitano Horses.

Like most mammalian, polyphasic sleep, equine sleep can be divided into two phases: the REM (rapid eye movement) phase and the NREM (non-rapid eye movement) phase. For this study, a randomized crossover experiment was conducted using ten purebred Lusitano horses, all dressage athletes aged from three to seven years old. The horses were filmed before the intervention to characterize their sleep patterns. REM sleep deprivation was achieved by not letting the horses attain sternal or lateral recumbency for three consecutive days, totaling 72 h. A spatial memory task and a visual attention test were performed. A recording time of 48 h appeared to be long enough to characterize the sleep patterns of the stalled horses. The total recumbency time of the studied population was lower than that previously reported in horses. Although the recumbency times before and after the intervention were similar, there was a tendency shown by the delta (p = 0.0839) towards an increased time needed to resolve spatial memory tasks in the sleep-deprived group. Future studies may deepen the understanding of horse sleep requirements and patterns, and the effects of environmental changes on horse sleep.

Chondrogenic potential of mesenchymal stem cells from horses using a magnetic 3D cell culture system.

BACKGROUND: Mesenchymal stem cells (MSCs) represent a promising therapy for the treatment of equine joint diseases, studied due to their possible immunomodulatory characteristics and regenerative capacity. However, the source of most suitable MSCs for producing cartilage for regenerative processes in conjunction with biomaterials for an enhanced function is yet to be established. AIM: To compare the chondrogenicity of MSCs derived from synovial fluid, bone marrow, and adipose tissue of horses, using the aggrecan synthesis. METHODS: MSCs from ten horses were cultured, phenotypic characterization was done with antibodies CD90, CD44 and CD34 and were differentiated into chondrocytes. The 3D cell culture system in which biocompatible nanoparticles consisting of gold, iron oxide, and poly-L-lysine were added to the cells, and they were forced by magnets to form one microspheroid. The microspheroids were exposed to a commercial culture medium for 4 d, 7 d, 14 d, and 21 d. Proteoglycan extraction was performed, and aggrecan was quantified by enzyme-linked immunosorbent assay. Keratan sulfate and aggrecan in the microspheroids were identified and localized by immunofluorescence. RESULTS: All cultured cells showed fibroblast-like appearance, the ability to adhere to the plastic surface, and were positive for CD44 and CD90, thus confirming the characteristics and morphology of MSCs. The soluble protein concentrations were higher in the microspheroids derived from adipose tissue. The aggrecan concentration and the ratio of aggrecan to soluble proteins were higher in microspheroids derived from synovial fluid than in those derived from bone marrow, thereby showing chondrogenic superiority. Microspheroids from all sources expressed aggrecan and keratan sulfate when observed using confocal immunofluorescence microscopy. All sources of MSCs can synthesize aggrecan, however, MSCs from synovial fluid and adipose tissue have demonstrated better biocompatibility in a 3D environment, thus suggesting chondrogenic superiority. CONCLUSION: All sources of MSCs produce hyaline cartilage; however, the use of synovial liquid or adipose tissue should be recommended when it is intended for use with biomaterials or scaffolds.

Hyaluronic acid has chondroprotective and joint-preserving effects on LPS-induced synovitis in horses.

The intra-articular use of hyaluronic acid (HA) for the treatment of synovitis and osteoarthritis is still controversial. As a consequence, corticosteroids remain the most frequently employed therapeutic agents, despite their potential systemic and local deleterious effects. This study examined the anti-inflammatory, antioxidant, and chondroprotective activities of low and high molecular weight hyaluronic acid (LMW-HA and HMW-HA) on lipopolysaccharide (LPS)-induced synovitis in horses compared to triamcinolone acetonide (TA). LPS was injected in the metacarpophalangeal joints, which were treated intra-articularly with either TA (as control) or LMW-HA or HMW-HA. Joint clinical evaluation and synovial fluid (SF) analysis were performed at 0, 8, 24, and 48 h. The white blood cell counts (WBC), prostaglandin E2 (PGE2), interleukin (IL)-1, IL-6, IL-10, tumor necrosis factor-α, chondroitin sulfate (CS) and HA concentrations, oxidative burst, and HA molecular weights were measured. TA reduced the lameness, swelling, and PGE2 release but increased the SF CS concentrations enormously at 24h and 48h, and decreased the SF HA modal molecular weight. These results indicate the breakdown of articular cartilage aggrecan and SF HA. In contrast, LMW-HA and HMW-HA were less effective in reducing the inflammation symptoms, but preserved the joints because only a modest increase in CS occurred at 24 h, decreasing at 48 h, and the SF HA was maintained. The HA-treatment also had anti-inflammatory actions, and LMW-HA was the most effective in reducing the release of cytokine. In summary, the HA treatment inhibited efficiently the digestion of cartilage proteoglycans and SF HA breakdown.

Does Double Centrifugation Lead to Premature Platelet Aggregation and Decreased TGF-ß1 Concentrations in Equine Platelet-Rich Plasma?

Blood-derived autologous products are frequently used in both human and equine medicine to treat musculoskeletal disorders. These products, especially the platelet-rich plasma (PRP), may contain high concentrations of growth factors (GFs), and thus improve healing in several tissues. Nevertheless, the procedures for preparation of PRP are currently non-standardized. Several protocols, which are based on distinct centrifugation patterns (rotation speed and time), result in PRPs with different characteristics, concerning platelet and GFs concentrations, as well as platelet activation. The aim of the present study was to compare two different protocols for PRP preparation: protocol (A) that is based on a single-centrifugation step; protocol (B), which included two sequential centrifugation steps (double-centrifugation). The results here reported show that the double-centrifugation protocol resulted in higher platelet concentration, while leukocytes were not concentrated by this procedure. Although platelet activation and aggregation were increased in this protocol in comparison to the single-centrifugation one, the TGF-ß1 concentration was also higher. Pearson's correlation coefficients gave a significant, positive correlation between the platelet counts and TGF-ß1 concentration. In conclusion, although the double-centrifugation protocol caused premature platelet aggregation, it seems to be an effective method for preparation of PRP with high platelet and TGF-ß1 concentrations.