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Topic:Ex Vivo Study
Ex vivo studies involve the examination of biological processes outside of a living organism, typically in a controlled laboratory environment. In equine research, ex vivo studies are used to investigate various physiological and pathological processes in tissues, cells, or organs derived from horses. These studies provide insights into cellular mechanisms, tissue responses, and the effects of various treatments or conditions without the complexities of a whole living system. Common applications in equine research include studying cartilage degradation, tendon repair, and immune responses. This page compiles peer-reviewed research studies and scholarly articles that explore the methodologies, findings, and implications of ex vivo studies in equine science.
Computed Tomographic Tenography of Normal Equine Digital Flexor Tendon Sheath: An Ex Vivo Study. Aim of this study was to document the normal computed tomographic tenography findings of digital flexor tendon sheath. Six ex vivo normal equine forelimbs were used. An axial approach was used to inject 185 mg/mL of iopamidol in a total volume of 60 mL into the digital flexor tendon sheaths. Single-slice helical scans, with 5 mm thickness, spaced every 3 mm, for a pitch of 0.6, and with bone algorithm reconstruction, were performed before and after injections of contrast medium. To obtain better image quality for multiplanar reconstruction and 3D reformatting, postprocessing retrorecon...
Microangiographic Comparison of the Effects of 3 Loop Pulley and 6 Strand Savage Tenorrhaphy Techniques on Equine Superficial Digital Flexor Tendon. The 6-strand Savage (SSS) tenorrhaphy pattern is biomechanically superior to the commonly employed 3-loop pulley (3LP); however, its effects on intrinsic tendon vasculature remain unknown. The objective of this study was to compare perfusion of intrinsic vasculature of the equine superficial digital flexor tendon (SDFT) after 3LP and SSS tenorrhaphies. We hypothesized that the SSS technique would significantly decrease vascular perfusion compared to the 3LP technique. Methods: Ex vivo, randomized, paired design. Methods: Horses (n = 9) METHODS: Under general anesthesia, 9 pairs of forelimb...
Influences of age and sex on leukocytes of healthy horses and their ex vivo cytokine release. Leukocytes and their functional capacities are used extensively as biomarkers in immunological research. Commonly employed indicators concerning leukocytes are as follows: number, composition in blood, response to discrete stimuli, cytokine release, and morphometric characteristics. In order to employ leukocytes as biomarkers for disease and therapeutic monitoring, physiological variations and influencing factors on the parameters measured have to be considered. The aim of this report was to describe the ranges of selected leukocyte parameters in a sample of healthy horses and to analyse wheth...
Effect of flunixin meglumine and firocoxib on ex vivo cyclooxygenase activity in horses undergoing elective surgery. To evaluate ex vivo cyclooxygenase (COX) inhibition and compare in vitro and ex vivo COX-1 inhibition by flunixin meglumine and firocoxib in horses. Methods: 4 healthy horses for in vitro experiments and 12 healthy horses (6 males and 6 females; 5 Thoroughbreds, 5 Warmbloods, and 2 ponies) undergoing elective surgery for ex vivo experiments. Methods: 12 horses received flunixin meglumine (1.1 mg/kg, IV, q 12 h) or firocoxib (0.09 mg/kg, IV, q 24 h). Blood samples were collected before (baseline) and 2 and 24 hours after NSAID administration. Prostanoids (thromboxane B2, prostaglandin E2, and p...
Evaluation of contact activation of citrated equine whole blood during storage and effects of contact activation on results of recalcification-initiated thromboelastometry. To evaluate the degree of activation of the contact pathway in citrated equine whole blood over holding times ≤ 30 minutes and assess effects of contact activation on recalcification-initiated thromboelastometry. Methods: 11 healthy adult mixed-breed horses. Methods: Blood was collected by atraumatic jugular venipuncture into prewarmed evacuated siliconized glass tubes containing citrate anticoagulant and held at 37°C for ≤ 30 minutes. Thromboelastometry was performed with an in vitro viscoelasticity (thromboelastometry) monitoring system. Factor XII and factor XI procoagulant activities ...
Effect of hoof angle on joint contact area in the equine metacarpophalangeal joint following simulated impact loading ex vivo. To add to the existing data on impact loading of the metacarpophalangeal (MCP) joint as a precursor to assessing the potential role of impact in joint disease. Objective: To examine the effect of impact loading on contact areas of the first phalanx (P1) and proximal sesamoids (PS) with the third metacarpal (McIII) under 3 hoof-strike conditions (toe-first, flat, heel-first). Methods: Randomised, repeated controlled experiment using cadaver material. Methods: Eight cadaver limbs were subjected to randomised, repeated controlled trials where the hoof was struck by a pendulum impact machine (impa...
Ex Vivo Anatomical Characterization of Handsewn or Stapled Jejunocecal Anastomosis in Horses by Computed Tomography Scan. The aim of this study is to compare handsewn and stapled jejunocecal anastomosis with different stomal lengths in terms of anatomical differences. Group 1 underwent a two-layer handsewn jejunocecal side-to-side anastomosis (HS); Group 2 received a stapled jejunocecal side-to-side anastomosis (GIA). Each group was divided into two subgroups (HS80 and HS100, GIA80 and GIA100). Specimens were inflated and CT scanned. The stomal/jejunal area ratio and blind end pouch volume/area were measured and compared. Effective length of the stoma was measured and compared with the initial length. Stomal/jeju...
Identification of surgically-induced longitudinal lesions of the equine deep digital flexor tendon in the digital flexor tendon sheath using contrast-enhanced ultrasonography: an ex-vivo pilot study. Longitudinal tears in the lateral aspect of the deep digital flexor tendon are the most common causes of pain localised to the equine digital flexor tendon sheath. However conventional ultrasonographic techniques provide limited information about acute lesions. Ultrasonographic contrast agents are newly developed materials that have contributed to advancement in human diagnostic imaging. They are currently approved for intravenous use in human and animal models. In this study we described intrathecal use in the horse. This study was undertaken to evaluate the reliability of standard and angle ...
Ex vivo evaluation of carpal flexion after partial carpal arthrodesis in horses. To determine degrees of flexion after arthrodesis of the antebrachiocarpal (ABC) joint, middle carpal (MC), and carpometacarpal (CMC) joints combined (MC/CMC), and carpometacarpal (CMC) joint alone. Methods: Ex vivo study. Methods: Forelimbs (n = 9) from 2- to 10-year-old Quarter Horses (5), Thoroughbred (2), and American Paint Horse (2). Methods: Using 2 locking compression plates, 3 partial carpal arthrodesis techniques were performed. Cables and deadweights were connected to limbs and each angle of flexion determined 3 times using a protractor and then averaged. Control measurements were ob...
Impact of equine herpesvirus type 1 (EHV-1) infection on the migration of monocytic cells through equine nasal mucosa. The mucosal surfaces are important sites of entry for a majority of pathogens, and viruses in particular. The migration of antigen presenting cells (APCs) from the apical side of the mucosal epithelium to the lymph node is a key event in the development of mucosal immunity during viral infections. However, the mechanism by which viruses utilize the transmigration of these cells to invade the mucosa is largely unexplored. Here, we establish an ex vivo explant model of monocytic cell transmigration across the nasal mucosal epithelium and lamina propria. Equine nasal mucosal CD172a(+) cells (nmCD...
Ex vivo equine medial tibial plateau contact pressure with an intact medial femoral condyle, with a medial femoral condylar defect, and after placement of a transcondylar screw through the condylar defect. To determine ex vivo contact data on the equine medial tibial plateau loaded by an intact medial femoral condyle (MFC), by an MFC with an osteochondral defect, and with a screw inserted in lag fashion through the MFC defect. Methods: Ex vivo experiment. Methods: Stifles (n = 6). Horses (n = 4). Methods: Stifle joints were axially loaded to 1800 N at 155°, 145°, and 130°, under 3 conditions: Intact, MFC with a 15 mm circular osteochondral defect, and with a transcondylar screw inserted in lag fashion through the defect. An electronic pressure sensor (Tekscan®) on the medial tibial plateau...
Computed tomographic imaging of subchondral fatigue cracks in the distal end of the third metacarpal bone in the thoroughbred racehorse can predict crack micromotion in an ex-vivo model. Articular stress fracture arising from the distal end of the third metacarpal bone (MC3) is a common serious injury in Thoroughbred racehorses. Currently, there is no method for predicting fracture risk clinically. We describe an ex-vivo biomechanical model in which we measured subchondral crack micromotion under compressive loading that modeled high speed running. Using this model, we determined the relationship between subchondral crack dimensions measured using computed tomography (CT) and crack micromotion. Thoracic limbs from 40 Thoroughbred racehorses that had sustained a catastrophic in...
Mechanical comparison of 3 anchoring techniques in the muscular process for laryngoplasty in the equine larynx. To compare mechanical properties of 2 techniques with a conventional technique for anchoring the muscular process in a laryngoplasty procedure. Methods: Experimental ex vivo study. Methods: Equine larynges (n = 60). Methods: A single loop (SL), a screw (SC), and a double loop technique (DL) were compared. Constructs were subjected to cyclic loading, oscillating from 5 to 50 N for 3000 cycles, followed by a single cycle to failure test. Mean distraction, load at failure, stiffness, and failure mode were compared between groups. Results: Mean ± SD distraction in cyclic loading was greater for D...
Effect of N-butylscopolammonium bromide on equine ileal smooth muscle activity in an ex vivo model. N-butylscopolammonium bromide (NBB) is an anticholinergic agent used to treat spasmodic colic in horses. Intestinal smooth muscle spasm also occurs in horses with intraluminal intestinal obstructions, such as ileal impactions. The antispasmodic effects of NBB may be useful in managing ileal impactions, but the effects of NBB on equine ileal smooth muscle are unknown. Objective: To investigate the effects of NBB on spontaneous and induced contraction of the equine ileum in an ex vivo model. Methods: Ex vivo biomechanical study assessing contractile properties in isolate equine ileal smooth musc...
Secretoglobin 1A1 and 1A1A differentially regulate neutrophil reactive oxygen species production, phagocytosis and extracellular trap formation. Secretoglobin family 1A member 1 (SCGB 1A1) is a small protein mainly secreted by mucosal epithelial cells of the lungs and uterus. SCGB 1A1, also known as club (Clara) cell secretory protein, represents a major constituent of airway surface fluid. The protein has anti-inflammatory properties, and its concentration is reduced in equine recurrent airway obstruction (RAO) and human asthma. RAO is characterized by reversible airway obstruction, bronchoconstriction and neutrophilic inflammation. Direct effects of SCGB 1A1 on neutrophil functions are unknown. We have recently identified that the SC...
Critical evaluation of ex vivo restoration of carious equine maxillary cheek teeth infundibulae following high-pressure gas and micro-particle abrasion. Infundibular caries of the equine maxillary cheek teeth is an important disorder that can lead to dental fracture or apical infection. Treatment by removing food debris and carious dental tissue from affected infundibulae using high-pressure abrasion with aluminium hydroxide micro-particles, followed by filling the cleaned defect with endodontic restorative materials is a recommended treatment. However, although anecdotally considered a successful treatment option, there is currently no objective evidence to support this claim. Forty maxillary cheek teeth (CT) that contained 55 infundibulae wi...
Ex vivo comparison of the biomechanical properties of hand-sewn and stapled jejunoileal anastomoses in horses. To compare bursting strength, construction time, and anastomotic dimensions of 4 jejunoileal anastomotic techniques. Methods: Experimental ex vivo study. Methods: Adult horses (n = 12). Methods: Jejunoileal anastomoses were constructed from harvested ileal and distal jejunal segments using a single-layer Lembert technique (1HS), double-layer simple continuous/Cushing technique (2HS), stapled side-to-side technique (SS), or stapled functional end-to-end technique (FEE). Anastomotic construction time was recorded. Bursting pressures (BP), bursting wall tension (BWT), percentage of mean anastomot...
Effect of hoof orientation and ballast on acceleration and vibration in the hoof and distal forelimb following simulated impacts ex vivo. We wished to add to the existing baseline data on impact loading of the distal limb as a precursor to assessing the potential role of impact in injury and joint disease. Objective: To examine the effect of 3 hoof-strike conditions (toe first, flat and heel first) and 2 specimen masses (with and without a ballast of ∼2% body mass) on impact deceleration and vibration frequencies and energies at the hoof, first phalanx and third metacarpal. Methods: Biomechanical experiments in cadaver material. Methods: Eight cadaver limbs were subjected to randomised, repeated controlled trials, in which the...
An ex vivo model to evaluate the effect of cyclical adductory forces on maintenance of arytenoid abduction after prosthetic laryngoplasty performed with and without mechanical arytenoid abduction. To (1) develop a model of cyclical adduction force on an abducted left arytenoid cartilage that mimics swallowing or coughing; (2) determine if arytenoid abduction by a clamp before knot tying will improve the maintenance of abduction under cyclical adduction testing. Methods: Experimental. Methods: Cadaveric equine larynges (n = 14). Methods: Left laryngoplasty performed using a single suture of #5 Ethibond with (n = 7) and without (n = 7) abducting the arytenoid with a clamp before knot tying. Each laryngoplasty was loaded cyclically from 2 to 26 N at 0.5 Hz for 5000 cycles i...
Ex vivo evaluation of 7 polydioxanone for closure of equine ventral midline celiotomies. The objective of this study was to compare the bursting strength (BS) and mode of failure (MF) of ventral midline (VM) celiotomies closed with USP 7 polydioxanone (7PD) in 1 or 2 simple continuous sections. A bursting strength model, consisting of inserting and inflating a 200-L polyurethane bladder through a 25-cm VM celiotomy, was used on 15 fresh equine cadavers. Celiotomies were closed using 7PD in 2 separate sections (4 knots), 2 continuous sections (3 knots), or a single section (2 knots) using a simple continuous pattern. The horses' signalment, body weight, number of total knots, MF, a...
Controlled nail delivery of a novel lipophilic antifungal agent using various modern drug carrier systems as well as in vitro and ex vivo model systems. The penetration behavior into human nails and animal hoof membranes of a novel antifungal agent (EV-086K) for the treatment of onychomycosis was investigated in this study. The new drug provides a high lipophilicity which is adverse for penetration into nails. Therefore, four different formulations were developed, with particular focus on a colloidal carrier system (CCS) due to its penetration enhancing properties. On the one hand, ex vivo penetration experiments on human nails were performed. Afterwards the human nail plates were cut by cryomicrotome in order to quantify the drug concentratio...
Comparison of tensile strength and early healing of acute repeat celiotomy through a ventral median or a right ventral paramedian approach. To compare tensile strength, failure location, and histologic features after acute repeat celiotomy through a ventral median (RVM) or a right ventral paramedian (RVP) celiotomy in horses. Methods: Ex vivo experimental study. Methods: Adult horses (N = 18). Methods: Twelve adult horses had original ventral median (OVM) celiotomy. Repeat celiotomy was performed 72 hours postoperatively through the original ventral median (RVM, N = 6) or a RVP (N = 6) celiotomy. Celiotomies were scored daily for edema, drainage, and dehiscence. Fourteen days after repeat celiotomy, horses were eutha...
Comparison between palpation and ultrasonography for evaluation of experimentally induced effusion in the distal interphalangeal joint of horses. To ultrasonographically quantify experimentally induced effusion of the distal interphalangeal (DIP) joint of horses and compare results with those obtained with palpation. Methods: 8 forelimbs from equine cadavers and forelimbs of 5 mares. Methods: Preliminary ex vivo experiments were performed to validate the methods. Then, the DIP joints of the forelimbs of standing horses were serially distended with saline (0.9% NaCl) solution (1, 4, and 10 mL) by injection through an intra-articular catheter. Two ultrasonographers measured distension of the dorsal recess of the DIP joint, and 2 surgeons,...
Biomechanical comparison of four technique for pelvic flexure enterotomy closure in horses. To compare 4 techniques for pelvic flexure enterotomy closure in horses. Methods: Ex-vivo study. Methods: Cadaveric ascending colon specimens (n = 48 horses). Methods: Pelvic flexure enterotomies of different lengths (5 cm, 10 cm) were performed and closed with 1 of 4 techniques: handsewn 2 layer (HS2); handsewn 1 layer (HS1); skin staples (SKS); or TA90 stapling device (TA90). Time to close each enterotomy, bursting pressure, luminal reduction, and cost were calculated and compared. Results: HS2 was significantly more time consuming to perform in the 5 cm group whereas in the 10 cm group, onl...
Tensile properties in collagen-rich tissues of Quarter Horses with hereditary equine regional dermal asthenia (HERDA). Hereditary equine regional dermal asthenia (HERDA) is an autosomal recessive disorder of Quarter Horses characterised by skin fragility. Horses with HERDA have a missense mutation in peptidyl-prolyl cis-trans isomerase B (PPIB), which encodes cyclophilin B and alters folding and post translational modifications of fibrillar collagen. Objective: The study aimed to test the hypothesis that tendons, ligaments and great vessels, which, like skin, are rich in fibrillar collagen, will also have abnormal biomechanical properties in horses with HERDA. Methods: Ex vivo biomechanical study comparing...
Efficacy of cyclo-oxygenase inhibition by two commercially available firocoxib products in horses. Two firocoxib preparations for oral use are approved for use in animals in many countries: a chewable canine tablet and an equine paste. In order to reduce costs, many veterinarians use the canine product in horses even though this is an off-label use of the preparation. Objective: To determine the relative efficacy of 2 commercially available firocoxib products to inhibit prostaglandin E₂ (PGE2) synthesis after oral dosing in horses. Methods: A crossover design using 8 adult horses (n = 4 for each preparation during each treatment period). Body weight range 532-614 kg. Methods: Horses recei...
Arthroscopic optical coherence tomography provides detailed information on articular cartilage lesions in horses. Arthroscopy enables direct inspection of the articular surface, but provides no information on deeper cartilage layers. Optical coherence tomography (OCT), based on measurement of reflection and backscattering of light, is a diagnostic technique used in cardiovascular surgery and ophthalmology. It provides cross-sectional images at resolutions comparable to that of low-power microscopy. The aim of this study was to determine if OCT is feasible for advanced clinical assessment of lesions in equine articular cartilage during diagnostic arthroscopy. Diagnostic arthroscopy of 36 metacarpophalangea...
Experimental model of equine alveolar macrophage stimulation with TLR ligands. Pulmonary diseases are common in horses and have a major economic impact on the equine industry. Some of them could be associated with an inadequate immune response in the lung, but methods to evaluate this response in horses are lacking. The aim of this study was to develop and validate an experimental model that could be applied in several physiological and pathological conditions to assess the innate immune response of equine pulmonary cells. Equine alveolar macrophages (AMs) obtained from bronchoalveolar lavages were isolated from other cells by adhesion. TLR2, 3, and 4 expression in AMs w...
Synovial distribution of “systemically” administered acetylsalicylic acid in the isolated perfused equine distal limb. This study investigated synovial concentrations of acetylsalicylic acid (ASA) and its metabolite salicylic acid (SA) in the equine fetlock joint following systemic administration of ASA. Salicylates were chosen because SA is the only nonsteroidal anti-inflammatory drug for which threshold levels exist for plasma and urine in equine sports. To avoid animal experiments, the study was conducted using an ex vivo model of the isolated perfused equine distal limb in combination with plasma concentrations obtained from literature.Salicylate concentrations in the joint were determined using microdialy...
