Early degenerative changes are different between partial and complete anterior cruciate ligament injury and associate with joint instability in a skeletally immature porcine model.

Objective: Anterior cruciate ligament (ACL) injuries are a major problem in the pediatric and adolescent populations. Some of these injuries are only partial; yet, there is limited data to inform clinical treatment of such partial tears. It is unknown how injury partial injury impacts long-term degenerative changes in the joint relative to complete injury.

Matrikine stimulation of equine synovial fibroblasts and chondrocytes results in an in vitro osteoarthritis phenotype.

Osteoarthritis (OA) is a debilitating disease that impacts millions of individuals and has limited therapeutic options. A significant hindrance to therapeutic discovery is the lack of in vitro OA models that translate reliably to in vivo preclinical animal models. An alternative to traditional inflammatory cytokine models is the matrikine stimulation model, in which fragments of matrix proteins naturally found in OA tissues and synovial fluid, are used to stimulate cells of the joint.

Pyrrolidine-2,3-diones: heterocyclic scaffolds that inhibit and eradicate biofilms.

The absence of novel antibiotic classes, coupled with the rising threat of antibiotic persistence and resistance, is pushing the world perilously close to a new pre-antibiotic era. Over 35 000 people die every year in the US as a consequence of antimicrobial-resistant infections. Bacterial biofilms further complicate this scenario, as they are inherently more resistant to antibiotic treatments.

Temperature has a greater effect than salinity on microbial survival in saltwater from a single equine hydrotherapy unit.

Objective: To determine the ability of bacteria commonly isolated from equine limb wounds to survive in saltwater obtained from an equine hydrotherapy unit at different salinity concentrations and temperatures.

Methods: Saltwater samples were obtained over a 2-week period (January 22, 2024 to February 2, 2024) from an equine hydrotherapy unit used for clinical patients, kept at either full salinity per manufacturer recommendations or diluted to half salinity to mimic the dilution that likely occurs in the clinical setting between cases when holding tanks are replenished with tap water only. Samples were then autoclaved to eliminate preexisting bacterial contamination before individual inoculation with Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Streptococcus zooepidemicus.

Fighting fibrin with fibrin: Vancomycin delivery into coagulase-mediated Staphylococcus aureus biofilms via fibrin-based nanoparticle binding.

Staphylococcus aureus skin and soft tissue infection is a common ailment placing a large burden upon global healthcare infrastructure. These bacteria are growing increasingly recalcitrant to frontline antimicrobial therapeutics like vancomycin due to the prevalence of variant populations such as methicillin-resistant and vancomycin-resistant strains, and there is currently a dearth of novel antibiotics in production. Additionally, S.

Systemic absorption of triamcinolone acetonide is increased from intrasynovial versus extrasynovial sites and induces hyperglycemia, hyperinsulinemia, and suppression of the hypothalamic-pituitary-adrenal axis.

Steroid-associated laminitis remains a major concern with use of corticosteroids in horses. Individual case factors such as joint pathology, pre-existing endocrinopathies, or corticosteroid type, dose, and timing influencing steroid-induced laminitis risk have not been investigated. This study aimed to determine if systemic absorption of triamcinolone acetonide (TA) varies between intrasynovial (antebrachiocarpal) and extrasynovial (sacroiliac) injection sites, and to determine the effects of TA absorption on glucose, insulin, cortisol, and adrenocorticotropic hormone (ACTH).

Ultrasoft platelet-like particles stop bleeding in rodent and porcine models of trauma.

Uncontrolled bleeding after trauma represents a substantial clinical problem. The current standard of care to treat bleeding after trauma is transfusion of blood products including platelets; however, donated platelets have a short shelf life, are in limited supply, and carry immunogenicity and contamination risks. Consequently, there is a critical need to develop hemostatic platelet alternatives.

IL-1β + TGF-β2 dual-licensed mesenchymal stem cells have reduced major histocompatibility class I expression and positively modulate tenocyte migration, metabolism, and gene expression.

Objective: The study objectives were to 1) determine the mesenchymal stem cell (MSC) surface expression of major histocompatibility complex (MHC) class I and transcriptome-wide gene expression changes following IL-1β + TGF-β2 dual licensing and 2) evaluate if IL-1β + TGF-β2 dual-licensed MSCs had a greater ability to positively modulate tenocyte function compared to naive MSCs.

Sample: Equine bone marrow-derived MSCs from 6 donors and equine superficial digital flexor tenocytes from 3 donors.

Methods: Experiments were performed in vitro.

Controlled Stiffness of Direct-Write, Near-Field Electrospun Gelatin Fibers Generates Differences in Tenocyte Morphology and Gene Expression.

Tendinopathy is a leading cause of mobility issues. Currently, the cell-matrix interactions involved in the development of tendinopathy are not fully understood. In vitro tendon models provide a unique tool for addressing this knowledge gap as they permit fine control over biochemical, micromechanical, and structural aspects of the local environment to explore cell-matrix interactions.

Surgical procedure of intratympanic injection and inner ear pharmacokinetics simulation in domestic pigs.

One major obstacle in validating drugs for the treatment or prevention of hearing loss is the limited data available on the distribution and concentration of drugs in the human inner ear. Although small animal models offer some insights into inner ear pharmacokinetics, their smaller organ size and different barrier (round window membrane) permeabilities compared to humans can complicate study interpretation. Therefore, developing a reliable large animal model for inner ear drug delivery is crucial.

Expanded library of novel 2,3-pyrrolidinedione analogues exhibit anti-biofilm activity.

Herein we report a new library of 2,3-pyrrolidinedione analogues that expands on our previous report on the antimicrobial studies of this heterocyclic scaffold. The novel 2,3-pyrrolidinediones reported herein have been evaluated against S. aureus and methicillin-resistant S.

No correlation found between palpation and ultrasound for evaluation of effusion in the medial femorotibial and femoropatellar joint compartments of horses.

Objective: To compare palpation and ultrasound scores of effusion of the medial femorotibial and femoropatellar joints of horses.

Animals: 40 horses (80 stifles) were evaluated over a 12-week period.

Methods: Horses > 1 year of age without history of stifle disease were enrolled from September to December 2022.

Animal drug shortages limit veterinary therapeutic options and introduce artifacts in antimicrobial sales reporting.

Supply chain issues disrupt veterinary care and cause downstream consequences that alter the practice of veterinary medicine. Antimicrobials are just 1 class of pharmaceuticals that have been impacted by supply chain issues over the last couple of years. Since February 2021, 2 sponsors/manufacturers of penicillin products have reported shortages in the active pharmaceutical ingredient.

Mesenchymal stem cell licensing: enhancing MSC function as a translational approach for the treatment of tendon injury.

Tendon injuries are common in both veterinary and human clinical patients and result in morbidity, pain, and lost athletic performance. Consequently, utilizing naturally occurring injuries in veterinary patients as a comparative model could inform the development of novel therapies and increase translation for the treatment of human tendon injuries. Mesenchymal stem cells (MSCs) have shown considerable efficacy for the treatment of experimental and clinical superficial digital flexor tendon injury in the horse; however, the reinjury rate following treatment can remain high and MSC efficacy in treating other tendons is less well known.

Use of mesenchymal stem cells for tendon healing in veterinary and human medicine: getting to the "core" of the problem through a one health approach.

The purpose of this manuscript, which is part of the Currents in One Health series, is to take a comparative approach to stem cell treatment for tendon injury and consider how the horse might inform treatment in other veterinary species and humans. There is increasing experimental and clinical evidence for the use of bone marrow-derived mesenchymal stem cells to treat tendon injuries in the horse. The same evidence does not currently exist for other species.

Preclinical tendon and ligament models: Beyond the 3Rs (replacement, reduction, and refinement) to 5W1H (why, who, what, where, when, how).

Several tendon and ligament animal models were presented at the 2022 Orthopaedic Research Society Tendon Section Conference held at the University of Pennsylvania, May 5 to 7, 2022. A key objective of the breakout sessions at this meeting was to develop guidelines for the field, including for preclinical tendon and ligament animal models. This review summarizes the perspectives of experts for eight surgical small and large animal models of rotator cuff tear, flexor tendon transection, anterior cruciate ligament tear, and Achilles tendon injury using the framework: "Why, Who, What, Where, When, and How" (5W1H).

Antimicrobial Properties of Equine Stromal Cells and Platelets and Future Directions.

Increasing antimicrobial resistance in veterinary practice has driven the investigation of novel therapeutic strategies including regenerative and biologic therapies to treat bacterial infection. Integration of biological approaches such as platelet lysate and mesenchymal stromal cell (MSC) therapy may represent adjunctive treatment strategies for bacterial infections that minimize systemic side effects and local tissue toxicity associated with traditional antibiotics and that are not subject to antibiotic resistance. In this review, we will discuss mechanisms by which biological therapies exert antimicrobial effects, as well as potential applications and challenges in clinical implementation in equine practice.

Effect of gentamicin on CD3+ T-lymphocyte proliferation for treatment of equine recurrent uveitis: An in vitro study.

Objective: The objective of the study was to determine the effect of gentamicin on CD3+ T-lymphocyte proliferation and cell viability using an in vitro cell culture model as a means of investigating the mechanism of action of low-dose intravitreal gentamicin injection.

Animals Studied: Three adult horses with no evidence of ophthalmic or systemic disease.

Procedure: Peripheral blood lymphocytes were treated with gentamicin at concentrations 37.

Pneumatic compression therapy using the EQ Press accelerates lymphatic flow in healthy equine forelimbs as determined by lymphoscintigraphy.

Objective: Limb lymphedema in horses can be debilitating and painful. Pneumatic compression therapy has shown significant benefits for people suffering from lymphedema. The objective of this study was to determine the effect of a novel, equine-specific pneumatic compression device on the lymphatic flow of healthy horse forelimbs as determined by Tc-99m sulfur colloid lymphoscintigraphy.

TLR-activated mesenchymal stromal cell therapy and antibiotics to treat multi-drug resistant septic arthritis in an equine model.

Background: Rapid development of antibiotic resistance necessitates advancement of novel therapeutic strategies to treat infection. Mesenchymal stromal cells (MSC) possess antimicrobial and immunomodulatory properties, mediated through antimicrobial peptide secretion and recruitment of innate immune cells including neutrophils and monocytes. TLR-3 activation of human, canine and equine MSC has been shown to enhance bacterial killing and clearance , in rodent biofilm infection models and dogs with spontaneous multi-drug-resistant infections.

TGF-β2 enhances expression of equine bone marrow-derived mesenchymal stem cell paracrine factors with known associations to tendon healing.

Background: Mesenchymal stem cells (MSCs) secrete paracrine factors and extracellular matrix proteins that contribute to their ability to support tissue healing and regeneration. Both the transcriptome and the secretome of MSCs can be altered by treating the cells with cytokines, but neither have been thoroughly investigated following treatment with the specific cytokine transforming growth factor (TGF)-β2.

Methods: RNA-sequencing and western blotting were used to compare gene and protein expression between untreated and TGF-β2-treated equine bone marrow-derived MSCs (BM-MSCs).

Interleukin-1β in tendon injury enhances reparative gene and protein expression in mesenchymal stem cells.

Tendon injury in the horse carries a high morbidity and monetary burden. Despite appropriate therapy, reinjury is estimated to occur in 50-65% of cases. Although intralesional mesenchymal stem cell (MSC) therapy has improved tissue architecture and reinjury rates, the mechanisms by which they promote repair are still being investigated.

Alterations to the synovial invaginations of the navicular bone are associated with pathology of both the navicular apparatus and distal interphalangeal joint when evaluated using high field MRI.

Limited information exists regarding associations between distal interphalangeal joint (DIPJ) abnormalities and synovial invagination changes in the distal sesamoid (navicular) bone. This retrospective, analytical study aimed to measure specific characteristics of the synovial invaginations of the navicular bone to determine whether any single characteristic was associated with abnormalities in the DIPJ or navicular apparatus (NA) using high field MRI and a sample of 200 horses' feet. The DIPJ and NA were graded independently by three scorers.