Horseshoe effects on equine gait-A systematic scoping review.

OBJECTIVE: To provide an overview of available research about effects of horseshoes on equine kinetics and kinematics. METHODS: The terms, "horse/equine," "hoof," "shoes/horseshoes," "kinetics," and "kinematics" were searched in PubMed, Web of Science, Center for Agriculture and Bioscience International, and United States Department of Agriculture National Agricultural Library for manuscripts from first availability to 2024. Independent reviewers used preferred reporting items for systematic reviews and meta-analyses guidelines to map and extract evidence-based data from sources. Metrics included participant demographics, research methods, major findings, and study limitations. Knowledge gaps were also identified. RESULTS: A total of 46 studies were included. Most utilized non-lame horses to compare original shoe designs or modifications to unshod or a standard open-heel shoe. Horse demographics and gait, study design and outcome measures varied widely. Prevalent data collection equipment included force platforms and pressure plates, wearable force measuring technology, and videography. Many studies reported shoeing effects on limb forces and motion, but there was little consensus among unrelated studies. Common limitations included insufficient data resolution, no randomization, small sample size, single breed, and outcome measures specific or unique to the study. Knowledge gaps included data collection from all limbs and the impact of conformation and limb and hoof morphology and health condition on outcomes. CONCLUSION: Information from manuscripts that met inclusion criteria confirmed distinct, variable effects of shoe characteristics on equine gait parameters. CLINICAL SIGNIFICANCE: Details from published work can serve as resource for clinical decisions and to guide standardization among investigations on shoe configuration effects on equine motion.

Dehydrated Human Amniotic-Chorionic Membrane Reduces Incisional Hernia Formation in an Animal Model.

BACKGROUND: Currently there are no standard of care treatment strategies for IH prevention (IHP). Dehydrated human amnion-chorion (dHACM) is a healing adjunct that elutes growth factors including several that have reduced IH in animal models. We therefore performed a double-blinded, prospective randomized controlled trial (RCT) to test the hypothesis that dHACM significantly reduces IH formation in a well-studied animal model of acute IH. MATERIAL AND METHODS: Forty 16-week-old male Sprague-Dawley rats were randomized to one of four groups: No Treatment vs. dHACM Sheet (Group A), and Saline vs. dHACM Injection (Group B). Each animal underwent a 5-cm midline laparotomy which was incompletely closed with 5-0 plain gut sutures; this was performed by a surgeon blinded to treatment group (first blind). After 28 days, the primary endpoints of IH formation and hernia size were determined by study staff blinded to treatment (second blind). Secondary endpoints included healed fascia tensile strength as determined by tensiometry, systemic and local inflammatory markers as measured by ELISA, and fascial scar collagen I/III ratios per Western blotting. RESULTS: In Group A, No Treatment developed IH at 87.5% vs. 62.5% for Sheet (P = 0.28). Hernias that formed in the Sheet group were significantly smaller (P = 0.036). In Group B, Injection and Saline yielded identical IH rates of 77.8%. Molecular characterization of fascial scar demonstrated non-inferior tensile strength, collagen I/III ratios, and inflammatory markers in dHACM-treated animals. CONCLUSIONS: dHACM sheets significantly reduced the size of IH following laparotomy when compared to no treatment.

The Equine Hoof: Laminitis, Progenitor (Stem) Cells, and Therapy Development.

The equine hoof capsule, composed of modified epidermis and dermis, is vital for protecting the third phalanx from forces of locomotion. There are descriptions of laminitis, defined as inflammation of sensitive hoof tissues but recognized as pathologic changes with or without inflammatory mediators, in the earliest records of domesticated horses. Laminitis can range from mild to serious, and signs can be acute, chronic, or transition from acute, severe inflammation to permanently abnormal tissue. Damage within the intricate dermal and epidermal connections of the primary and secondary lamellae is often associated with lifelong changes in hoof growth, repair, and conformation. Decades of research contribute to contemporary standards of care that include systemic and local therapies as well as mechanical hoof support. Despite this, consistent mechanisms to restore healthy tissue formation following a laminitic insult are lacking. Endogenous and exogenous progenitor cell contributions to healthy tissue formation is established for most tissues. There is comparably little information about equine hoof progenitor cells. Equine hoof anatomy, laminitis, and progenitor cells are covered in this review. The potential of progenitor cells to advance in vitro equine hoof tissue models and translate to clinical therapies may significantly improve prevention and treatment of a devastating condition that has afflicted equine companions throughout history.

Experimental Model of Zygomatic and Mandibular Defects to Support the Development of Custom Three-Dimensional--Printed Bone Scaffolds.

INTRODUCTION: Autologous reconstruction of segmental craniomaxillofacial bone defects is limited by insufficient graft material, donor site morbidity, and need for microsurgery. Reconstruction is challenging due to the complex three-dimensional (3D) structure of craniofacial skeleton. Customized 3D-printed patient-specific biologic scaffolds hold promise for reconstruction of the craniofacial skeleton without donor site morbidity. The authors report a porcine craniofacial defect model suitable for further evaluation of custom 3D-printed engineered bone scaffolds. METHODS: The authors created a 6 cm critical load-bearing defect in the left mandibular angle and a 1.5 cm noncritical, nonload bearing defect in the contralateral right zygomatic arch in 4 Yucatan minipigs. Defects were plated with patient-specific titanium hardware based on preoperative CT scans. Serial CT imaging was done immediately postoperatively, and at 3 and 6 months. Animals were clinically assessed for masticatory function, ambulation, and growth. At the 6-month study endpoint, animals were euthanized, and bony regeneration was evaluated through histological staining and micro-CT scanning compared to contralateral controls. RESULTS: All 4 animals reached study endpoint. Two mandibular plates fractured, but did not preclude study completion due to loss of masticatory function. One zygoma plate loosened while the site of another underwent heterotopic ossification. Gross examination of site defects revealed heterotopic ossification, confirmed by histological and micro-CT evaluation. Biomechanical testing was unavailable due to insufficient bony repair. CONCLUSIONS: The presented porcine zygoma and mandibular defect models are incapable of repair in the absence of bone scaffolds. Based on the authors' results, this model is appropriate for further study of custom 3D-printed engineered bone scaffolds.

Extracorporeal shock wave therapy improves short-term limb use after canine tibial plateau leveling osteotomy.

OBJECTIVE: To determine the influence of postoperative extracorporeal shock wave therapy (ESWT) on hind limb use after tibial plateau leveling osteotomy (TPLO). STUDY DESIGN: Randomized, prospective clinical trial. ANIMALS: Sixteen client-owned dogs, 2 to 10 years old weighing 18 to 75 kg. METHODS: Dogs were randomly assigned to treatment cohorts, TPLO with ESWT (ESWT, n = 9) or TPLO without ESWT (control, n = 7). Treatment consisted of 1000 pulses at 0.15 mJ/mm2 immediately and 2 weeks after surgery. Subjective pain, stifle goniometry, stifle circumference, peak vertical force (PVF) and vertical impulse (VI) were measured before surgery, prior to ESWT, and 2 and 8 weeks after surgery. Measures were compared between treatments at each time point and among time points for each treatment (P < .05). RESULTS: The PVF (5.5 ± 1.0 N/kg, mean ± SD) and VI (0.67 ± 0.14 N-s/kg) of surgically treated limbs in the ESWT cohort were higher 8 weeks after surgery compared with preoperative (3.8 ± 1.1 N/kg, P < .0001 and 0.47 ± 0.21 N-s/kg, P = .0012, respectively) values. In the control cohort, PVF (2.9 ± 1.3 N/kg, P = .0001) and VI (0.33 ± 0.20 N-s/kg, P = .0003) 2 weeks after surgery and VI (0.42 ± 0.2 N-s/kg, P = .0012) 8 weeks after surgery were lower (4.59 ± 2.33 N/kg and 0.592 ± 0.35 N-s/kg, respectively) than before surgery. Other parameters did not differ between groups. CONCLUSION: Weight bearing increased faster after TPLO in dogs treated with postoperative ESWT. CLINICAL SIGNIFICANCE: This study provides evidence to consider adjunct ESWT after TPLO.

Adult multipotent stromal cell cryopreservation: Pluses and pitfalls.

Study and clinical testing of adult multipotent stromal cells (MSCs) are central to progressive improvements in veterinary regenerative medicine. Inherent limitations to long-term culture preclude use for storage. Until cell line creation from primary isolates becomes routine, MSC stasis at cryogenic temperatures is required for this purpose. Many protocols and reagents, including cryoprotectants, used for veterinary MSCs are derived from those for human and rodent cells. Dissimilarities in cryopreservation strategies play a role in variable MSC behaviors. Familiarity with contemporary cryopreservation reagents and processes is essential to an appreciation of their impact on MSC survival and post-cryopreservation behavior. In addition to these points, this review includes a brief history and description of current veterinary stem cell regulation.

Joint stability after canine cranial cruciate ligament graft reconstruction varies among femoral fixation sites.

OBJECTIVE: To quantify stability in cranial cruciate ligament (CrCL) deficient canine stifles with hamstring grafts affixed at 3 femoral locations. STUDY DESIGN: Canine stifle motion study using a multi-cohort, repeated measures design. SAMPLE POPULATION: 27 canine cadaver stifles. METHODS: Hamstring grafts (HG) were affixed at the gracilis-semitendinosus insertion and on the lateral femur (1) proximal trochlear ridge (TR), (2) craniodistal to fabella (F), or (3) condyle center (CC). Total, cranial, and caudal tibial translation and total, medial, and lateral angular displacement, with and without translational load, were quantified with the CrCL intact, transected, and reconstructed. Angular displacement was quantified from points on the distal femur and proximal tibia. Graft strain was calculated from tissue displacement measured at joint angles of 30°, 60°, 90°, and 120°. RESULTS: Tibial translation was lowest in F constructs, which also achieved the least difference in tibial translation from intact stifles. Tibial translation was lower in intact stifles than in CrCL transected or reconstructed stifles. Less angular displacement of the proximal tibia was detected in the medial than in the lateral direction, and tibial displacement was lower in the cranial than the caudal direction. Angular displacement was lowest in the F treatment group. F constructs had the lowest graft strain at joint angles greater than 30°. CONCLUSIONS: Femoral fixation of a canine hamstring graft craniodistal to the lateral fabella conferred the best joint stability and lowest graft strain in vitro. No fixation method restored joint stability of the intact CrCL.

Canine Adult Adipose Tissue-Derived Multipotent Stromal Cell Isolation, Characterization, and Differentiation.

Adult mesenchymal stromal/stem cells (MSCs) are a standard component of de novo tissue generation to treat and study injury, disease, and degeneration. Canine patients constitute a major component of veterinary practice, and dogs share numerous pathologic conditions with humans. The relative abundance of adipose-derived stromal/stem cells (ASCs) in various canine adipose tissue depots is well described. Refined isolation, characterization, and differentiation techniques contribute to the collective knowledge of ASC phenotypes and subpopulations for specific tissue targets. Continued efforts to advance the knowledge of canine ASC behavior in vivo are critical to harnessing the full potential of primary cell isolates. This chapter contains a description of techniques to isolate, characterize, and differentiate canine ASCs.

Feline Adult Adipose Tissue-Derived Multipotent Stromal Cell Isolation and Differentiation.

Cats are among the most popular household pets. However, compared to other species, there is little information specific to feline adult mesenchymal stromal/stem cells. Despite the phylogenetic distance between domesticated cats, Felis silvestris catus, and humans, they share some similar health challenges like kidney disease, asthma, and diabetes. Investigative efforts have been focused on adult adipose-derived stromal/stem cell (ASC) therapies to address feline illnesses, including de novo pancreatic tissue generation for diabetes treatment. Given the relatively small size of domestic cats, optimized cell isolation from small quantities of adipose tissue is important in the development of feline ASC-based therapies. Additionally, there are unique features of feline ASC culture conditions and characterization. This chapter contains a few of the novel aspects of feline ASC isolation, culture, preservation, and differentiation.

Biocomposite Anchors Have Greater Yield Load and Energy Compared With All-Suture Anchors in an In Vitro Ovine Infraspinatus Tendon Repair Model.

Purpose: To compare tensile fatigue and strength measures of biocomposite and all-suture anchors in an ovine humerus-infraspinatus tendon model of rotator cuff repair. Methods: Infraspinatus tendons on adult ovine humeri were sharply transected at the insertion. One of each pair was assigned randomly for fixation with 2 biocomposite or all-suture anchors. Constructs were tested with 200 cycles of 20 to 70 N tensile load, and gap formation was measured at the incised tendon end every 50 cycles. They were subsequently tested to failure. Outcome measures including fatigue stiffness, hysteresis, creep, and gap formation and tensile stiffness, and yield and failure displacement, load, and energy were compared between anchors. Results: Biocomposite anchors had greater yield load (134.1 ± 6.5 N, P < .01) and energy (228.6 ± 85.7 J, P < .03) than all-suture anchors (104.7 ± 6.5 N, 169.8 ± 85.7 J). Fatigue properties were not different between anchors, but stiffness and gap formation increased and hysteresis and creep decreased significantly with increasing cycle number. Conclusions: Although the yield displacement of both anchors was within the range of clinical failure, the tensile yield load and energy of ovine infraspinatus tendons secured to the humerus with 2 single-loaded all-suture anchors in a single row were significantly lower than those secured with 2 biocomposite anchors in the same configuration. Clinical Relevance: It is important to understand the biomechanical properties for selecting anchors for rotator cuff repair. A direct comparison of fatigue testing followed by failure strength of infraspinatus tendon fixation with all-suture and biocomposite anchors could help guide anchor selection and postoperative mobility recommendations.

A novel reconstruction model for thoracic spinal cord injury in swine.

Spinal cord (SC) reconstruction (process to reestablish the severed neural continuity at the injury site) may provide better recovery from blunt SC injury (SCI). A miniature swine model of blunt SC compression was used to test the hypothesis that reconstruction of the SC with sural nerve in combination with surgical decompression and stabilization improves functional, macro- and microstructural recovery compared to decompression and stabilization alone. Following blunt T9-T11 SC compression injury, five adult Yucatan gilts randomly received laminectomy and polyethylene glycol (as fusogen) with (n = 3) or without (n = 2) sural nerve graft SC reconstruction. Fusogens are a heterogeneous collection of chemicals that fuse the axon membrane and are currently used to augment epineural coaptation during peripheral nerve graft reconstruction. Outcome measures of recovery included weekly sensory and motor assessments, various measurements obtained from computed tomography (CT) myelograms up to 12 weeks after injury Measurements from postmortem magnetic resonance imaging (MRI) and results from spinal cord histology performed 12 weeks after injury were also reported. Vertebral canal (VC), SC and dural sac (DS) dimensions and areas were quantified on 2-D CT images adjacent to the injury. Effort to stand and response to physical manipulation improved 7 and 9 weeks and 9 and 10 weeks, respectively, after injury in the reconstruction group. Myelogram measures indicated greater T13-T14 VC, smaller SC, and smaller DS dimensions in the reconstruction cohort, and increased DS area increased DS/VC area ratio, and higher contrast migration over time. Spinal cord continuity was evident in 2 gilts in the reconstruction cohort with CT and MRI imaging. At the SCI, microstructural alterations included axonal loss and glial scarring. Better functional outcomes were observed in subjects treated with sural nerve SC reconstruction. Study results support the use of this adult swine model of blunt SCI. Long-term studies with different nerve grafts or fusogens are required to expand upon these findings.

Adult multipotent stromal cell technology for bone regeneration: a review.

Since the discovery of bone marrow derived stromal cell osteogenesis in the 1960s, tissue engineering with adult multipotent stromal cells (MSCs) has evolved as a promising approach to restore structure and function of bone compromised by injury or disease. To date, accelerated bone formation with MSCs has been demonstrated with a variety of tissue engineering strategies. Though MSC bone tissue engineering has advanced over the last few decades, limitations to clinical translation remain. A current review of this promising field is presented with a specific focus on equine investigations.

Canine intra-articular multipotent stromal cells (MSC) from adipose tissue have the highest in vitro expansion rates, multipotentiality, and MSC immunophenotypes.

OBJECTIVE: To identify the optimum intra-articular multipotent stromal cell (MSC) tissue source in the canine stifle. STUDY DESIGN: Experimental. SAMPLE POPULATION: Infrapatellar adipose tissue, synovium lining the joint capsule, and synovium surrounding the cranial cruciate ligament (CrCL) from normal stifles of 6 dogs. METHODS: Nucleated cell density for each tissue was determined, and cell doublings (CD) and doubling times (DT) were quantified for expansion rates. Adipogenic, osteogenic, and chondrogenic differentiation was confirmed with light microscopy. Fibroblastic, adipogenic, and osteogenic colony forming unit frequencies were determined for multipotentiality. Tissue-specific target gene expression was assessed, and percentages of CD29(+) , CD34(+) , CD44(+) , CD45(+) , and CD90(+) cells quantified. RESULTS: Adipose tissue had the highest MSC density (ASC). The CD decreased with increasing passages for all cell types, and ASC values tended to be higher. Multipotentiality decreased with passage, but remained highest in ASC. Tissue-specific target gene expression was higher in induced versus noninduced cells, and ASCs had the highest upregulation across passages. Most cells were CD29(+) , CD44(+) , CD90(+) , and percentages decreased with passage. Within cell types, there were more CD29(+) ASC in early passages and more CD44(+) and CD90(+) ASC in later passages. CONCLUSIONS: ASC had the highest in vitro expansion rates, CFU frequencies, tissue-specific target gene expression, and percentages of MSC immunophenotypes.

Shoe configuration effects on third phalanx and capsule motion of unaffected and laminitic equine hooves in-situ.

Equine shoes provide hoof protection and support weakened or damaged hoof tissues. Two hypotheses were tested in this study: 1) motion of the third phalanx (P3) and hoof wall deformation are greater in laminitic versus unaffected hooves regardless of shoe type; 2) P3 displacement and hoof wall deformation are greatest while unshod (US), less with open-heel (OH), then egg-bar (EB) shoes, and least with heart-bar (HB) shoes for both hoof conditions. Distal forelimbs (8/condition) were subjected to compressive forces (1.0x102-5.5x103 N) while a real-time motion detection system recorded markers on P3 and the hoof wall coronary band, vertical midpoint, and solar margin. Magnitude and direction of P3 displacement and changes in proximal and distal hemi-circumference, quarter and heel height and proximal and distal heel width were quantified. Hoof condition and shoe effects were assessed with 2-way ANOVA (p<0.05). P3 displacement was greater in laminitic hooves when US or with OH, and EB and HB reduced P3 displacement in laminitic hooves. P3 displacement was similar among shoes in unaffected hooves and greatest in laminitic hooves with OH, then US, EB and HB. EB and HB increased P3 displacement from the dorsal wall in unaffected hooves and decreased it in laminitic hooves. OH and EB increased P3 motion from the coronary band in laminitic hooves, and HB decreased P3 motion toward the solar margin in unaffected and laminitic hooves. In laminitic hooves, HB reduced distal hemi-circumference and quarter deformation and increased heel deformation and expansion. Proximal hemi-circumference constriction was inversely related to proximal heel expansion with and without shoes. Overall, shoe configuration alters hoof deformation distinctly between unaffected and laminitic hooves, and HB provided the greatest P3 stability in laminitic hooves. These unique results about P3 motion and hoof deformation in laminitic and unaffected hooves inform shoe selection and design.

Wrist motion is distinct between touch screen and manual or digital devices.

BACKGROUND: Restricted motion during touch screen device use may contribute to wrist overuse injuries. Wrist radioulnar deviation and extension while using touch screen devices and digital or manual counterparts in male and female medical professional dominant and non-dominant hands were quantified to test the hypothesis that mobile touch screen device use reduces wrist motion. METHODS: An active motion detection system was used to record wrist motion of 12 participants while: tablet swiping and turning book pages; raising a cell and traditional phone to the ear; texting and typing; and entering numbers on a cell phone and manual calculator. Medial and lateral wrist surface range of motion (ROM) and minimum and maximum wrist radial-ulnar deviation and flexion-extension were quantified. RESULTS: Device, sex and handedness effects were determined (P<0.05). Maximum medial radial deviation and ROM were greater using a cell versus traditional phone. Maximum medial radial deviation was higher in the nondominant wrist during backward tablet swiping and while backward page turning versus tablet swiping. Maximum and minimum medial extension angles and ROM were greater while typing versus texting. Female nondominant hand maximum lateral extension and ROM were greater for typing versus texting and maximum medial extension and lateral extension ROM greater during manual versus cell phone calculator use with handedness combined. Maximum lateral extension and ROM were greater in females versus males using manual calculators. CONCLUSIONS: Sex and handedness should instruct touch screen, digital and manual device design and use for optimal performance and injury prevention.

Agmatine Administration Effects on Equine Gastric Ulceration and Lameness.

Osteoarthritis (OA) accounts for up to 60% of equine lameness. Agmatine, a decarboxylated arginine, may be a viable option for OA management, based on reports of its analgesic properties. Six adult thoroughbred horses, with lameness attributable to thoracic limb OA, received either daily oral phenylbutazone (6.6 mg/kg), agmatine sulfate (25 mg/kg) or a control for 30 days, with 21-day washout periods between treatments. Subjective lameness, thoracic limb ground reaction forces (GRF), plasma agmatine and agmatine metabolite levels were evaluated using an established rubric, a force platform, and mass spectrometry, respectively, before, during and after each treatment period. Gastric ulceration and plasma chemistries were evaluated before and after treatments. Braking GRFs were greater after 14 and 29 days of agmatine compared to phenylbutazone administration. After 14 days of phenylbutazone administration, vertical GRFs were greater than for agmatine or the control. Glandular mucosal ulcer scores were lower after agmatine than phenylbutazone administration. Agmatine plasma levels peaked between 30 and 60 min and were largely undetectable by 24 h after oral administration. In contrast, plasma citric acid levels increased throughout agmatine administration, representing a shift in the metabolomic profile. Agmatine may be a viable option to improve thoracic limb GRFs while reducing the risk of glandular gastric ulceration in horses with OA.

Hemodynamic Changes in Response to Hyperacute Spinal Trauma in a Swine Model.

Acute spinal cord injury (ASCI) is a devastating event that can have severe hemodynamic consequences, depending on location and severity of the lesion. Knowledge of hyperacute hemodynamic changes is important for researchers using porcine models of thoracic ASCI. The goal of this study was to determine the hyperacute hemodynamic changes observed after ASCI when using pigs as their own controls. Five Yucatan gilts were anesthetized, and a dorsal laminectomy performed at T10-T12. Standardized blunt trauma was applied for 5 consecutive min, and hemodynamic variables were collected 5 min before ASCI, and at 2, 4, 6, 8, 10, 20, 30, 60, 80 and 120 min after ASCI. Arterial blood gas samples were collected at 60 min and 10 min before, and at 30 min and between 120 and 240 min after ASCI. Parametric data were analyzed using a mixed effects model with time point as the fixed factor and subject as the random factor. We found no effect on heart rate, pulse pressure, SpO2, EtCO2, and respiratory rate between baseline and timepoints after ASCI. Diastolic arterial pressure, mean arterial pressure, and systolic arterial pressure fell significantly by 18%, 16%, and 15%, respectively, at 2 min after ASCI. However, none of the decrements in arterial pressures resulted in hypotension at any time point. Heart rate did not change significantly after ASCI. Blood glucose progressively increased to 50% above baseline between 120 and 240 minutes after ASCI. Low thoracic ASCI caused a consistent and statistically significant but clinically minor hyperacute decrease in arterial pressures (-15%) that did not produce hypotension or metabolic changes suggestive of tissue hypoperfusion. Our findings using this model suggest that mean arterial pressures should be maintained above 85 mm Hg prior to spinal trauma in order to avoid hypotensive states after ASCI.

Feline Adipose Derived Multipotent Stromal Cell Transdifferentiation Into Functional Insulin Producing Cell Clusters.

Diabetes mellitus (DM) is one of the most prevalent feline endocrinopathies, affecting up to 1% of pet cats. De novo generation of functional insulin producing cell (IPC) clusters via transdifferentiation of feline adipose-derived multipotent stromal cells (ASCs) may not only provide a viable, functional cell therapy for feline DM, but may also serve as a platform for developing a comparable human treatment given feline and human DM similarities. Cells were induced to form IPCs with a novel, three-stage culture process with stromal or differentiation medium under static and dynamic conditions. Clusters were evaluated for intracellular zinc, viability, intracellular insulin, glucagon, and somatostatin, ultrastructure, glucose stimulated insulin secretion in the presence or absence of theophylline, and protein and gene expression. Isolated cells were multipotent, and cell clusters cultured in both media had robust cell viability. Those cultured in differentiation medium contained zinc and mono- or polyhormonal α-, ß-, and δ-like cells based on immunohistochemical labeling and Mallory-Heidenhan Azan-Gomori's staining. Ultrastructurally, cell clusters cultured in differentiation medium contained insulin granules within vesicles, and clusters had a concentration-dependent insulin response to glucose in the presence and absence of theophylline which increased both insulin secretion and intracellular content. Expression of NK6.1, Pax6, Isl1, Glut2, RAB3A, glucagon, insulin, and somatostatin increased with differentiation stage for both sexes, and expression of nestin at stages 1 and 2 and Neurod1 at stage 2 was higher in cells from female donors. The cluster insulin secretion responses and endocrine and oncogene gene expression profiles were inconsistent with insulinoma characteristics. A total of 180 proteins were upregulated in differentiated clusters, and the majority were associated with biological regulation, metabolic processes, or stimulus response. Dynamic culture of IPC clusters resulted in clusters composed of cells primarily expressing insulin that released higher insulin with glucose stimulation than those in static culture. Collectively, the results of this study support generation of functional IPC clusters using feline ASCs isolated from tissues removed during routine sterilization. Further, cluster functionality is enhanced with dynamic, motion-driven shear stress. This work establishes a foundation for development of strategies for IPC therapy for short or long-term diabetes treatment and may represent an option to study prevention and treatment of diabetes across species.

Computed tomography myelography technique and spinal morphometry in healthy Yucatan pigs.

Porcine models of spinal cord injury (SCI) have an irreplaceable role in the development of experimental therapies. There is little literature regarding CT myelogram (CTM) techniques in swine and morphometry in miniature swine has not been established. A CT-guided method for performing myelography as well as reference values for spinal morphometry in healthy Yucatan miniature swine is lacking. The goal of this study is to describe a CT-guided method of performing CTM in a porcine model of SCI and to establish spinal morphometric reference values in mature Yucatan pigs. Six healthy, Yucatan sows, 9 months of age, weighing between 39-57.7kg, with no history of spinal disease, spinal injury, or neurologic deficits on physical exam were used in this study. CT myelography was performed in each sow under general anesthesia. CT scout images were used to guide needle placement at the L3-L4 intervertebral site. Once correct needle placement was confirmed using a 1ml test injection, a full dose of iodinated contrast (0.3ml/kg) was injected slowly over a 2-minute time period. Morphometry was performed using area measurements of the spinal cord (SC), vertebral body (VB), dural sac (DS), and vertebral canal (VC) at the mid-body and the intervertebral disc space of each spinal segment. Of the quantitative measurements, the spinal cord surface area had the widest range of values and the greatest coefficient of variance (CV) while those parameters for the vertebral canal had a low CV. Of the morphometric ratios, the DS:VC, had the lowest CV while the spinal cord ratios to DS and VC had the highest (>30). The vertebral canal surface area and the dural space: vertebral canal ratio may serve as reference values in future studies using this animal model.

Point-of-care treatment of geometrically complex midfacial critical-sized bone defects with 3D-Printed scaffolds and autologous stromal vascular fraction.

Critical-sized midfacial bone defects present a unique clinical challenge due to their complex three-dimensional shapes and intimate associations with sensory organs. To address this challenge, a point-of-care treatment strategy for functional, long-term regeneration of 2 cm full-thickness segmental defects in the zygomatic arches of Yucatan minipigs is evaluated. A digital workflow is used to 3D-print anatomically precise, porous, biodegradable scaffolds from clinical-grade poly-ε-caprolactone and decellularized bone composites. The autologous stromal vascular fraction of cells (SVF) is isolated from adipose tissue extracts and infused into the scaffolds that are implanted into the zygomatic ostectomies. Bone regeneration is assessed up to 52 weeks post-operatively in acellular (AC) and SVF groups (BV/DV = 0.64 ± 0.10 and 0.65 ± 0.10 respectively). In both treated groups, bone grows from the adjacent tissues and restores the native anatomy. Significantly higher torque is required to fracture the bone-scaffold interface in the SVF (7.11 ± 2.31 N m) compared to AC groups (2.83 ± 0.23 N m). Three-dimensional microcomputed tomography analysis reveals two distinct regenerative patterns: osteoconduction along the periphery of scaffolds to form dense lamellar bone and small islands of woven bone deposits growing along the struts in the scaffold interior. Overall, this study validates the efficacy of using 3D-printed bioactive scaffolds with autologous SVF to restore geometrically complex midfacial bone defects of clinically relevant sizes while also highlighting remaining challenges to be addressed prior to clinical translation.