Ingestion of fishing gear and Anisakis sp. infection in a beached Indo-Pacific finless porpoise (Neophocaena phocaenoides) in the Jeju Island, Republic of Korea: findings from post-mortem computed tomography and necropsy.

BACKGROUND: Human fishing activities have significantly affect environmental concern for marine ecosystems, conservation of marine mammals, and human health. Coastal cetaceans are highly vulnerable to ingestion of fishing gear, bycatching, or entanglement, all of which can be fatal for these animals. In particular, certain coastal dolphins and porpoises are heavily impacted by fishing gear such as angling gear or stownet, as their food often overlap with the target fish species of human fisheries. CASE PRESENTATION: This study presents a case of an Indo-Pacific finless porpoise (Neophocaena phocaenoides) beached on the coast of Jeju Island, Republic of Korea, with ingestion of fishing gear and severe Anisakis infection. Although this species inhabits waters ranging from the Persian Gulf to Taiwan, several stranded carcasses have been reported on Jeju Island in recent years. Post-mortem computed tomography revealed a bundle of four fishing hooks in the forestomach, along with nylon lines and steel lines with connectors, which were assumed to be angling gear for Jeju hairtail (Trichiurus lepturus). Further necroscopic investigation revealed that the forestomach contained a large number of Anisakis spp. (Nematoda: Anisakidae). Histological examination revealed a thickened forestomach wall with pinpoint and volcanic ulcerations, a thickened layer of stratified squamous epithelium, and infiltrated stroma in the squamous epithelium. CONCLUSIONS: This study emphasizes the urgent need to address the impact of fishing activities on marine mammals, marine litter pollution, and the bycatch problem in Korean seawater. In addition, the occurrence of N. phocaenoides in seawater around Jeju Island should be raised in future geographical ecology or veterinary pathology studies and when its distribution is updated.

Cell-permeable bone morphogenetic protein 2 facilitates bone regeneration by promoting osteogenesis.

The use of the FDA-approved osteoinductive growth factor BMP2 is widespread for bone regeneration. However, its clinical application has been hindered by limitations in cell permeability and a short half-life in circulation. To address this issue, we have developed a modified version of BMP2, referred to as Cell Permeable (CP)-BMP2, which possesses improved cell permeability. CP-BMP2 incorporates an advanced macromolecular transduction domain (aMTD) to facilitate transfer across the plasma membrane, a solubilization domain, and recombinant human BMP2. Compared to traditional rhBMP2, CP-BMP2 exhibits enhanced cell permeability, solubility, and bioavailability, and activates Smad phosphorylation through binding to BMP receptor 2. The effectiveness of CP-BMP2 was evaluated in three animal studies focusing on bone regeneration. In the initial study, mice and rabbits with critical-size calvarial defects received subcutaneous (SC) injections of CP-BMP2 and rhBMP2 (7.5 mg/kg, 3 injections per week for 8 weeks).Following 8 weeks of administration, CP-BMP2 demonstrated a remarkable 65 % increase in bone formation in mice when compared to both the vehicle and rhBMP2. Moreover, rabbits exhibited faster bone formation, characterized by a filling pattern originating from the center. In a subsequent study involving injured horses, hind limb bones treated with CP-BMP2 exhibited an 85 % higher bone regeneration rate, as evidenced by Micro-CT results, in contrast to horses treated with the vehicle or rhBMP2 (administered at 150 µg/defect, subcutaneously, once a week for 8 weeks, without a scaffold). These results underscore the potential of CP-BMP2 to facilitate rapid and effective healing. No noticeable adverse effects, such as ectopic bone formation, were observed in any of the studies. Overall, our findings demonstrate that CP-BMP2 holds therapeutic potential as a novel and effective osteogenic agent.

Computed tomographic dimensions and densities of the normal eye in Jeju horses.

This study aimed to describe the computed tomographic (CT) dimensions and the contrast attenuation of the eye in Jeju horses and Thoroughbreds. We evaluated the CT images of 10 Jeju horses and 6 Thoroughbreds without ocular abnormalities to assess the ocular dimensions and contrast attenuation. The following measurements showed significant differences between Jeju horses and Thoroughbreds (P<0.05): the diameters of the lens, globe, posterior segment, orbital fossa, and lateromedial distance of the anterior chamber; and the Hounsfield units of the vitreous body. This study describes the CT anatomical characteristics of Jeju horses and Thoroughbreds and the differences between the two breeds and provides useful information for understanding and evaluating of the eyes of Jeju horses through a CT scan.

Glycoconjugate-Specific Developmental Changes in the Horse Vomeronasal Organ.

The vomeronasal organ (VNO) is a tubular pheromone-sensing organ in which the lumen is covered with sensory and non-sensory epithelia. This study used immunohistochemistry and lectin histochemistry techniques to evaluate developmental changes, specifically of the glycoconjugate profile, in the horse VNO epithelium. Immunostaining analysis revealed PGP9.5 expression in some vomeronasal non-sensory epithelium (VNSE) cells and in the vomeronasal receptor cells of the vomeronasal sensory epithelium (VSE) in fetuses, young foals, and adult horses. Olfactory marker protein expression was exclusively localized in receptor cells of the VSE in fetuses, young foals, and adult horses and absent in VNSE. To identify the glycoconjugate type, lectin histochemistry was performed using 21 lectins. Semi-quantitative analysis revealed that the intensities of glycoconjugates labeled with WGA, DSL, LEL, and RCA120 were significantly higher in adult horse VSE than those in foal VSE, whereas the intensities of glycoconjugates labeled with LCA and PSA were significantly lower in adult horse VSE. The intensities of glycoconjugates labeled with s-WGA, WGA, BSL-II, DSL, LEL, STL, ConA, LCA, PSA, DBA, SBA, SJA, RCA120, jacalin, and ECL were significantly higher in adult horse VNSE than those in foal VNSE, whereas the intensity of glycoconjugates labeled with UEA-I was lower in adult horse VNSE. Histochemical analysis of each lectin revealed that various glycoconjugates in the VSE were present in the receptor, supporting, and basal cells of foals and adult horses. A similar pattern of lectin histochemistry was also observed in the VNSE of foals and adult horses. In conclusion, these results suggest that there is an increase in the level of N-acetylglucosamine (labeled by WGA, DSL, LEL) and galactose (labeled by RCA120) in horse VSE during postnatal development, implying that they may influence the function of VNO in adult horses.

Adhesive Bowel Obstruction (ABO) in a Stranded Narrow-Ridged Finless Porpoise (Neophocaena asiaeorientalis sunameri).

In this case report, we present a rare occurrence of a narrow-ridged finless porpoise (Neophocaena asiaeorientalis sunameri), discovered on the coast of Jeju Island, Republic of Korea, that was afflicted with adhesive bowel obstruction (ABO), a life-threatening condition that has scarcely been reported in cetaceans. Diagnosis of ABO was confirmed via radiological and clinical assessments. Post-mortem computed tomography and necropsy revealed ABO between two loops of the jejunum at the L8 level. The mesenteric tissue covering the intestinal lesion was severely thickened with increased tension. Both bowel loops were fixed to the mesentery and acutely angulated, leading to asymmetrical thickening of the cross-sectional bowel walls. The intestinal lumen was stenosed because of pressure from the firm mesenteric band, and no fecal matter was observed in the lumen of the posterior bowel or rectum. Calcified nodules were detected, and histological analysis suggested parasitic or suspected post-parasitic infections. The primary cause of the intestinal lesions is presumed to be a reaction related to parasitic infection. However, further investigations would establish a definitive link between parasitic infections and ABO in this species. This case highlights the importance of studying rare medical conditions in wildlife, providing valuable insights into marine mammal health.

Fatal upper aerodigestive tract obstruction in an East Asian finless porpoise (Neophocaena asiaeorientalis sunameri): findings in post-mortem computed tomography.

The present case report aims to outline the post-mortem findings of an East Asian finless porpoise with upper aerodigestive tract obstruction using different post-mortem computed tomography (PMCT) visualization techniques and discusses the potential cause of death of this individual. A dead-stranded adult male East Asian finless porpoise was recovered from the Northern coast of Jeju Island, Republic of Korea. The carcass was frozen in Jeju National University within 2 h upon first reported. The PMCT examinations were performed at 120 kVp, 200 mAs with a section thickness of 1 mm. The scan field of view (sFOV) was set to 400 mm. Four image rendering techniques, including multi-planar reconstruction, three-dimensional volume rendering, perspective volume rendering, and minimum intensity projection technique, were used to aid the diagnosis of upper aerodigestive tract obstruction in the stranded finless porpoise. Conventional necropsy was performed to provide a complete necropsy report. Using PMCT, a Sebastidae of 24 cm measured length was found to be lodged in the left pharyngeal food channel and esophagus of the finless porpoise. Hard rays of the pectoral fin of the lodged fish have impaled the esophageal mucosa. Fishing gear was found to embed at the dorsal side of the lodged fish. The trachea was compressed ventrally and the arytenoepiglottic tube opening has been narrowed, which may precipitate to the finless porpoise difficult breathing. Pulmonary hyperinflation, pulmonary edema, pneumothorax, pneumopericardium, and pneumorrhachis were observed. This case report represents the first documentation of potential radiological indicators of upper aerodigestive tract obstruction in the East Asian finless porpoise using PMCT. Spatial location of the lodged item could be rendered in situ as the time of death. It has demonstrated that PMCT could provide objective measurements to adjunct the necropsy findings in diagnosis of fatal aerodigestive tract obstruction in stranded cetaceans.

In vitro effects of monophosphoryl lipid A and Poly I:C combination on equine cells.

BACKGROUND: Toll-like receptor (TLR) agonists have been used as adjuvants to modulate immune responses in both animals and humans. OBJECTIVES: The objective of this study was to evaluate the combined effects of the TLR 4 agonist monophosphoryl lipid A (MPL) and the TLR 3 agonist polyinosinic:polycytidylic acid (Poly I:C) on equine peripheral blood mononuclear cells (PBMCs), monocyte-derived dendritic cells (MoDCs), and bone marrow-derived mesenchymal stromal cells (BM-MSCs). METHODS: The PBMCs, MoDCs, and BM-MSCs collected from three mixed breed horses were treated with MPL, Poly I:C, and their combination. The mRNA expression of interferon gamma (IFN-γ), interleukin (IL)-1ß, IL-4, IL-6, IL-8, IL-12p40, tumor necrosis factor alpha (TNF-α), vascular endothelial growth factor (VEGF), and monocyte chemoattractant protein-1 (MCP-1) was determined using real-time polymerase chain reaction. RESULTS: The combination of MPL and Poly I:C significantly upregulated immunomodulatory responses in equine cells/ without cytotoxicity. The combination induced greater mRNA expression of pro-inflammatory cytokines IFN-γ and IL-6 than MPL or Poly I:C stimulation alone in PBMCs. In addition, the combination induced significantly higher mRNA expression of IL-1ß, IL-6, and IL-12p40 in MoDCs, and IL-8, MCP-1, and VEGF in BM-MSCs compared to stimulation with a single TLR agonist. CONCLUSIONS: The combination of MPL and Poly I:C can be used as a potential adjuvant candidate for vaccines to aid in preventing infectious diseases in horses.

Evaluation of concurrent vaccinations with recombinant canarypox equine influenza virus and inactivated equine herpesvirus vaccines.

Despite vaccination, equine influenza virus (EIV) and equine herpesvirus (EHV) infections still cause highly contagious respiratory diseases in horses. Recently, concurrent vaccination with EIV and EHV was suggested as a new approach; however, there have been no reports of concurrent vaccination with recombinant canarypox EIV and inactivated EHV vaccines. In this study, we aimed to compare the EIV-specific immune responses induced by concurrent administrations of a recombinant canarypox EIV vaccine and an inactivated bivalent EHV vaccine with those induced by a single recombinant canarypox EIV vaccine in experimental horse and mouse models. Serum and peripheral blood mononuclear cells (PBMCs) were collected from immunized animals after vaccination. EIV-specific serum antibody levels, serum hemagglutinin inhibition (HI) titers, and interferon-gamma (IFN-γ) levels were measured by enzyme-linked immunosorbent assay, HI assay, and quantitative polymerase chain reaction, respectively. Concurrent EIV and EHV vaccine administration significantly increased IFN-γ production, without compromising humoral responses. Our data demonstrate that concurrent vaccination with EIV and EHV vaccines can enhance EIV-specific cellular responses in horses.

Computed tomographic features of the temporomandibular joint in 10 Jeju horses.

BACKGROUND: The equine temporomandibular joint (TMJ) has a complex anatomical structure that makes diagnosis of TMJ disorders difficult. Computed tomography (CT) is now available in equine medicine; hence, TMJ evaluation has become more convenient. OBJECTIVES: The objectives of this study were to describe the CT features of the TMJ in Jeju horses and to compare these features with those of Thoroughbreds. METHODS: In this report, the TMJs of 10 Jeju horses (mean age: 4.5 ± 1.9 yr; mean body weight: 282.6 ± 40.3 kg) and 6 Thoroughbreds (mean age: 7.3 ± 1.6 yr; mean body weight: 479.7 ± 44.0 kg) were examined using CT. After CT scanning, the Hounsfield units (HU) and height to width ratio (H:W) of the mandibular condyle were measured. RESULTS: The mean H:W in Jeju horses was significantly lower than that in Thoroughbreds. The mean HU in Jeju horses was lower than that in Thoroughbreds; however, the difference was not significant. The most frequent CT finding was an irregular medial margin of the mandibular condyle in both breeds. CONCLUSIONS: In this study, the shape of the mandibular condyle in Jeju horses was flatter than that in Thoroughbreds. This report could be useful in evaluating the TMJ in Jeju horses. Moreover, CT could be a pragmatic choice for the examination of the TMJ in horses.

Analgesic and cardiopulmonary effects of premedication with tramadol in calves anesthetized with the infusion of guaifenesin and thiamylal.

This study examined the analgesic and cardiopulmonary effects of intravenous (IV) tramadol during general intravenous anesthesia in calves. Calves were premedicated with diazepam (0.2 mg/kg, IV) with tramadol (2 mg/kg, IV) (group T) or saline (group S). Anesthesia was induced by thiamylal sodium (4 mg/kg, IV) and maintained with an infusion (2 ml/kg/hr) of 5% guaifenesin containing thiamylal sodium (2 mg/ml). Additional thiamylal sodium (1-2 mg/kg, IV) was administered when interference from the calves was observed during surgery. The total counts of additional thiamylal sodium administration, analgesia score using a visual analog scale, recovery time, and cardiopulmonary function in the different groups were assessed and compared. Group T showed significantly fewer counts of additional drug administration and a significantly higher analgesia score. Tramadol may provide adequate analgesia with minimal cardiopulmonary changes in calves during general anesthesia.

Comparison of intraoperative cardiorespiratory and behavioral responses to medetomidine combined with tramadol or butorphanol during standing laparoscopic ovariectomy in horses.

The purpose of this study was to assess the cardiorespiratory and behavioral responses to the combination of medetomidine and tramadol (M-T) or butorphanol (M-B) in standing laparoscopic ovariectomy in horses. One ovary was removed under M-T and the contralateral ovary was removed under M-B with at least 4 weeks between operations at random. Horses were sedated using intravenous medetomidine (5 µg/kg) followed by tramadol (1 mg/kg) or butorphanol (10 µg/kg) after 5 min. Sedation was maintained through the repeated injection of medetomidine (1 µg/kg) and tramadol (0.4 mg/kg) or medetomidine (1 µg/kg) and butorphanol (4 µg/kg) every 15 min. Cardiorespiratory function and behavioral responses, including, sedation, ataxia, and analgesia, were assessed during the surgery. There were no significant differences in cardiorespiratory values and sedation and analgesia scores between M-T and M-B. Ataxia scores were significantly lower in M-T than in M-B. This result suggests that M-T could maintain smooth and stable standing surgery with minimal cardiorespiratory changes in horses.

Development of an Equine Antitoxin by Immunizing the Halla Horse with the Receptor-Binding Domain of Botulinum Neurotoxin Type A1.

Botulinum neurotoxins (BoNTs), produced by Clostridium botulinum, are the most toxic substances known. However, the number of currently approved medical countermeasures for these toxins is very limited. Therefore, studies on therapeutic antitoxins are essential to prepare for toxin-related emergencies. Currently, more than 10,000 Halla horses, a crossbreed between the native Jeju and Thoroughbred horses, are being raised in Jeju Island of Korea. They can be used for equine antitoxin experiments and production of hyperimmune serum against BoNT/A1. Instead of the inactivated BoNT/A1 toxoid, Halla horse was immunized with the receptor-binding domain present in the C-terminus of heavy chain of BoNT/A1 (BoNT/A1-HCR) expressed in Escherichia coli. The anti-BoNT/A1-HCR antibody titer increased rapidly by week 4, and this level was maintained for several weeks after boosting immunization. Notably, 20 µL of the week 24 BoNT/A1-HCR(-immunized) equine serum showed an in vitro neutralizing activity of over 8 international unit (IU) of a reference equine antitoxin. Furthermore, 20 µL of equine serum and 100 µg of purified equine F(ab')2 showed 100% neutralization of 10,000 LD50 in vivo. The results of this study shall contribute towards optimizing antitoxin production for BoNT/A1, which is essential for emergency preparedness and response.

Comparison of the methods for platelet rich plasma preparation in horses.

Platelet rich plasma (PRP) is popularly used in the horse industry to enhance regeneration of tissue injury that has limitation of blood supply. This study aimed to compare the methods for platelet rich plasma preparation since they has not been established yet. Blood was collected from six horses and platelets were concentrated by three different methods (2-step centrifugation, separated centrifugation and separated centrifugation using histopaque). Concentrated blood was analyzed using Advia hematology systems. In the result, separated centrifugation with histopaque showed the significantly lower number of red blood cells than other groups. The 2-step centrifugation showed the significantly higher number of white blood cells than other groups, while it contained the highest concentration of red blood cells among three groups. In the 2-step centrifugation, separated centrifugation and separated centrifugation with histopaque, platelets were concentrated 4.5, 5.3 and 5.6 times, respectively. And no significant difference of the platelet concentration between the three groups was found. This study demonstrated that separated centrifugation using histopaque was the best method for platelet rich plasma preparation because of the proper amount of platelets and the separation of red blood cells from platelet rich plasma.

Effects of a synovial flap and gelatin/ß-tricalcium phosphate sponges loaded with mesenchymal stem cells, bone morphogenetic protein-2, and platelet rich plasma on equine osteochondral defects.

This study aimed to evaluate the efficacy of a synovial flap and gelatin/ß-tricalcium phosphate (GT) sponge loaded with mesenchymal stem cells (MSCs), bone morphogenetic protein-2 (BMP-2), and platelet rich plasma (PRP) for repairing of osteochondral defects in horses. Osteochondral defects were created on the medial condyle of both femurs (n=5). In the test group, a GT sponge loaded with MSCs, BMP-2, and PRP (GT/MSCs/BMP-2/PRP) was inserted into the defect and then covered with a synovial flap. In the control group, the defect was treated only with the GT/MSCs/BMP-2/PRP. The test group showed significantly higher macroscopic scores than the control group. In addition, hyaline cartilaginous tissue was detected in the test group in areas larger than those in the control group. This study demonstrated that the combination of a synovial flap and GT sponge loaded with MSCs, BMP-2, and PRP promoted osteochondral regeneration in an equine model.

Minimally invasive proximal interphalangeal joint arthrodesis using a locking compression plate and tissue engineering in horses: a pilot study.

This pilot study assessed the efficacy of 2 minimally invasive techniques for proximal interphalangeal (PIP) joint arthrodesis in horses. The PIP joints of both forelimbs (n = 6) were stabilized with locking compression plates (LCP) using a minimally invasive technique (LCP technique). Subsequently, for 1 randomly selected PIP joint of each horse, surgical drilling (SurD) was performed and tissue engineering (TE) was applied (LCP/SurD/TE technique). Minimally invasive PIP joint arthrodesis with LCP demonstrated low postoperative infection rates. Gross and histological evaluations revealed considerable destruction of the articular cartilage in the LCP/SurD/TE-treated joints. In contrast, almost no destruction of the cartilage was observed in the LCP-treated joints. Our results suggest that the LCP technique alone is not sufficient for PIP joint arthrodesis and that the LCP/SurD/TE technique may be useful for PIP joint arthrodesis in horses.

Arthrodèse de l'articulation interphalangienne proximale à effraction minimale à l'aide d'une plaque de fixation à compression et de l'ingénierie tissulaire chez les chevaux : une étude pilote. Cette étude pilote a évalué l'efficacité de 2 techniques à effraction minimale pour l'arthrodèse de l'articulation interphalangienne proximale (AIP) chez les chevaux. Les articulations AIP des deux membres antérieurs (n = 6) ont été stabilisées avec des plaques de fixation à compression (PFC) à l'aide d'une technique à effraction minimale (technique PFC). Subséquemment, pour une articulation AIP choisie au hasard pour chaque cheval, un fraisage chirurgical (FC) a été réalisé et une ingénierie tissulaire (IT) a été appliquée (technique PFC/FC/IT). Une arthrodèse de l'articulation AIP à effraction minimale avec PFC a démontré de faibles taux d'infection postopératoire. Des évaluations brutes et histologiques ont révélé une destruction considérable du cartilage articulaire dans les articulations traitées à l'aide de la technique PFC/FC/IT. Par contraste, pratiquement aucune destruction du cartilage n'a été observée dans les articulations traitées par PCF. Nos résultats suggèrent que la technique PFC seule n'est pas suffisante pour l'arthrodèse des articulations AIP et que la technique PFC/FC/IT peut être utile pour l'arthrodèse de l'articulation AIP chez les chevaux.(Traduit par Isabelle Vallières).

In vitro biomechanical comparison of a 5-hole 4.5 mm locking compression plate and 5-hole 4.5 mm dynamic compression plate for equine proximal interphalangeal joint arthrodesis.

OBJECTIVE: To compare the biomechanical properties of a 5-hole 4.5 mm narrow locking compression plate (LCP) and 5-hole 4.5 mm narrow dynamic compression plate (DCP) for equine proximal interphalangeal (PIP) joint arthrodesis. STUDY DESIGN: Experimental mechanical study. ANIMALS: Cadaveric adult equine forelimbs (n = 6 pair). METHODS: For each forelimb pair, 1 PIP joint was stabilized with LCP and the contralateral PIP joint with DCP. The 6 construct pairs were tested using a single-cycle, 3-point dorsopalmar bending system. PIP joints were evaluated with pre- and post-test radiography. RESULTS: The LCP technique had significantly greater yield load, failure load, and stiffness under single-cycle, 3-point dorsopalmar bending to failure than the DCP technique. There was no significant difference between the 2 constructs for displacement at yield and failure point. CONCLUSIONS: Biomechanically, the LCP technique provided significantly greater stability than the DCP technique under the test condition.

Osteoinductivity of gelatin/ß-tricalcium phosphate sponges loaded with different concentrations of mesenchymal stem cells and bone morphogenetic protein-2 in an equine bone defect model.

Fracture is one of the most life-threatening injuries in horses. Fracture repair is often associated with unsatisfactory outcomes and is associated with a high incidence of complications. This study aimed to evaluate the osteogenic effects of gelatin/ß-tricalcium phosphate (GT) sponges loaded with different concentrations/ratios of mesenchymal stem cells (MSCs) and bone morphogenetic protein-2 (BMP-2) in an equine bone defect model. Seven thoroughbred horses were used in this study. Eight bone defects were created in the third metatarsal bones of each horse. Then, eight treatments, namely control, GT, GT/M-5, GT/M-6, GT/M-5/B-1, GT/M-5/B-3, GT/M-6/B-1, and GT/M-6/B-3 were applied to the eight different sites in a randomized manner (M-5: 2 × 10(5) MSCs; M-6: 2 × 10(6) MSCs; B-1: 1 µg of BMP-2; B-3: 3 µg of BMP-2). Repair of bone defects was assessed by radiography, quantitative computed tomography (QCT), and histopathological evaluation. Radiographic scores and CT values were significantly lower in the control group than in the other groups, while they were significantly higher in the GT/M-5/B-3 and GT/M-6/B-3 groups than in the other groups. The amount of mature compact bone filling the defects was greater in the GT/M-5/B-3 and GT/M-6/B-3 groups than in the other groups. The present study demonstrated that the GT sponge loaded with MSCs and BMP-2 promoted bone regeneration in an equine bone defect model. The GT/MSC/BMP-2 described here may be useful for treating horses with bone injuries.

The effect of a gelatin ß-tricalcium phosphate sponge loaded with mesenchymal stem cells (MSC), bone morphogenic protein-2, and platelet-rich plasma (PRP) on equine articular cartilage defect.

We evaluated the curative efficacy of a gelatin ß-tricalcium phosphate (ß-TCP) sponge loaded with mesenchymal stem cells (MSC), bone morphogenic protein-2 (BMP-2), and platelet-rich plasma (PRP) by insertion into an experimentally induced osteochondral defect. A hole of 10 mm diameter and depth was drilled in the bilateral medial femoral condyles of 7 thoroughbred horses, and into each either a loaded sponge (treatment) or a saline-infused ß-TCP sponge (control) was inserted. After 16 weeks, defects were examined by computed tomography, macroscopic analyses, and histological analyses. The median subchondral bone density and macroscopic subscores for joint healing were significantly higher in the treatment legs (P < 0.05). Although there was no significant difference in total histological scores between groups, hyaline cartilaginous tissue was observed across a wider area in the treatment group. Equine joint healing can be enhanced by inserting a BMP-2-, MSC-, and PRP-impregnated ß-TCP sponge at the lesion site.

L'effet d'une éponge de phosphate ß-tricalcique de gélatine imbibée de cellules souches mésenchymateuses (CSM), d'une protéine-2 morphogénétique osseuse et d'un plasma riche en plaquettes (PRP) sur un défaut de cartilage articulaire équin. Nous avons évalué l'efficacité curative d'une éponge de phosphate ß-tricalcique de gélatine (ß-TCP) imbibée de cellules souches mésenchymateuses (CSM), d'une protéine-2 morphogénétique osseuse (P2MO) et d'un plasma riche en plaquettes (PRP) en l'insérant dans un défaut ostéo-cartilagineux induit par expérimentation. Un trou de 10 mm de diamètre et de profondeur a été percé dans les condyles fémoraux médiaux bilatéraux de 7 pur-sang et, chez chaque cheval, une éponge imbibée (traitement) ou une éponge ß-TCP infusée d'une solution saline (témoin) a été insérée. Après 16 semaines, les défauts ont été examinés par tomographie par ordinateur, analyses macroscopiques et analyses histologiques. La densité osseuse sous-chondrale et les sous-notes médianes de la guérison des articulations étaient significativement supérieures dans les jambes traitées (P < 0,05). Même s'il n'y avait pas de différences significatives au niveau des notes histologiques totales entre les groupes, le tissu cartilagineux hyalin a été observé sur une région plus vaste dans le groupe de traitement. La guérison des articulations équines peut être améliorée en insérant une éponge ß-TCP imbibée de P2MO, de CSM et de PRP sur le site de la lésion.(Traduit par Isabelle Vallières).

Effects of bilayer gelatin/ß-tricalcium phosphate sponges loaded with mesenchymal stem cells, chondrocytes, bone morphogenetic protein-2, and platelet rich plasma on osteochondral defects of the talus in horses.

Osteochondrosis (OC) is a common and clinically important joint disorder in horses. However, repair of the OC region is difficult because of the avascular nature of cartilage. This study aimed to evaluate the efficacy of bilayer gelatin/ß-tricalcium phosphate (GT) sponges loaded with mesenchymal stem cells (MSCs), chondrocytes, bone morphogenetic protein-2 (BMP-2), and platelet rich plasma (PRP) for the repair of osteochondral defects of the talus in horses. Full-thickness osteochondral defects were created on both the lateral trochlear ridges of the talus (n = 6). In the test group, a basic GT sponge loaded with MSCs and BMP-2 (MSC/BMP2/GT) was inserted into the lower part of the defect, and an acidic GT sponge loaded with chondrocyte, MSCs, and PRP (Ch/MSC/PRP/GT) was inserted into the upper part of the defect. In the control group, the defect was treated only with bilayer GT sponges. Repair of osteochondral defects was assessed by radiography, quantitative computed tomography (QCT), and macroscopic and histological evaluation. The test group showed significantly higher radiographic, QCT, macroscopic, and histological scores than the control group. This study demonstrated that the bilayer scaffolds consisting of Ch/MSC/PRP/GT for the chondrogenic layer and MSC/BMP2/GT for the osteogenic layer promoted osteochondral regeneration in an equine model. The bilayer scaffolds described here may be useful for treating horses with OC.