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Clinically translatable large animal models have become indispensable for cardiovascular research, clinically relevant proof of concept studies and for novel therapeutic interventions. In particular, the pig has emerged as an essential cardiovascular disease model, because its heart, circulatory system, and blood supply are anatomically and functionally similar to that of humans. Currently, molecular and omics-based studies in the pig are hampered by the incompleteness of the genome and the lack of diversity of the corresponding transcriptome annotation. Here, we employed Nanopore long-read sequencing and in-depth proteomics on top of Illumina RNA-seq to enhance the pig cardiac transcriptome annotation. We assembled 15,926 transcripts, stratified into coding and non-coding, and validated our results by complementary mass spectrometry. A manual review of several gene loci, which are associated with cardiac function, corroborated the utility of our enhanced annotation. All our data are available for download and are provided as tracks for integration in genome browsers. We deem this resource as highly valuable for molecular research in an increasingly relevant large animal model.

Disc degeneration and associated back and neck pain elicits a substantial burden on healthcare systems and the individuals affected, necessitating the development of novel therapeutic strategies. This goal can only be achieved by a better understanding of intervertebral disc development, homeostasis and pathogenesis. A number of genetic and in-bred murine models are reviewed to underscore the importance of the mouse as an animal model of choice for the assessment of intervertebral disc pathobiology. Appraisals of the differences between mouse and human musculoskeletal systems and proteoglycan structures are also included. A number of important target pathways and molecules have been identified, many of which are worthy of further examination, requiring that the activity of these be confirmed in large animal models and assessed in the context of therapeutic intervention.

To gain regulatory approval for the clinical use of knee biologics and devices in humans, translational large-animal studies are typically required. Animal models that permit second-look arthroscopy are valuable because they allow for longitudinal assessment of the treated tissue without needing to sacrifice the animal. The minipig is an ideal preclinical animal model for the investigation of therapies for the knee, in part because arthroscopy can be performed in its stifle (knee) joint with the use of standard surgical equipment used in humans. The purpose of this Technical Note is to describe a reproducible technique for diagnostic arthroscopy of the minipig stifle (knee) joint., Technique Video Video 1 Diagnostic arthroscopy of the right minipig stifle (knee) joint. An anterolateral portal is established, the arthroscope is introduced through the anterolateral portal and into the medial compartment, and an anteromedial portal is established under spinal needle localization. The medial compartment, intercondylar notch, lateral compartment, and distal trochlea can be visualized. Visualization of the lateral compartment can be enhanced by placing the arthroscope through the anteromedial portal. The proximal portion of the patellofemoral joint can be difficult to visualize through the anterior portals because of its elongated morphology and inability to fully extend the minipig knee. Visualization of the proximal patellofemoral joint can be performed through a separate superior portal if necessary.

Background: Posttraumatic carotid artery dissection (PTCAD) is a common injury in motor vehicle accidents and other extension and rotation injuries, but rarely developed from being shaken vigorously. Case Description: A 7-day-old infant presented to our facility after being attacked by a large dog. Initial examination revealed multiple puncture wounds and lacerations with visible dura. Head CT demonstrated subarachnoid, intraparenchymal, and epidural hemorrhages as well as left hemispheric loss of gray-white differentiation. Thus, the patient presented similarly to shaken baby syndrome (SBS). The patient was taken emergently to the operating room for hematoma evacuation and dural repair. Postoperatively, worsened left hemispheric ischemia was noted and an MRA demonstrated a Grade IV left ICA dissection. No intervention, including anticoagulation, was sought as the stroke was determined to be complete with irreversible damage. Hospital course was complicated by worsening exam, seizures, and a retinal hemorrhage. At 2 years follow-up, the patient still has notable delays but is progressing slowly through milestones. Conclusion: Large animal attacks are a rare cause of PTCAD but may be due to the mechanism of shaking during the attack. We propose either CTA or MRA be considered as part of the initial workup in cases where an infant is attacked by a dog or other large animals, preventing delay of treatment.

Background: The issue of side holes in the tips of the tunneled cuffed central venous catheters is complex and has been subject to longstanding debate. This study sought to compare the clotting potential of the side-hole-free Pristine hemodialysis catheter with that of a symmetric catheter with side holes. Methods: Both jugular veins of five goats were catheterized with the two different catheters. The catheters were left in place for 4 weeks and were flushed and locked with heparin thrice weekly. The aspirated intraluminal clot length was assessed visually prior to each flushing. In addition, the size and weight of the clot were recorded upon catheter extraction at the end of the 4-week follow-up Results: The mean intraluminal clot length observed during the entire study follow-up measured up to a mean of 0.66 cm in the GlidePath (95% CI, 0.14–1.18) and 0.19 cm in the Pristine hemodialysis catheter (95% CI, −0.33 to 0.71), the difference being statistically significant ( p = 0.026). On average, 0.01 g and 0.07 g of intraluminal clot were retrieved from the Pristine and GlidePath catheters, respectively ( p = 0.052). Conclusion: The Pristine hemodialysis catheter was largely superior to a standard side hole catheter in impeding clot formation, and, contrary to the side hole catheter, allowed for complete aspiration of the intraluminal clot.

Objective Regulatory guidelines for preclinical cartilage repair studies suggest large animal models (e.g., sheep, goat, [mini]-pig, or horse) to obtain results representative for humans. However, information about the 3-dimensional thickness of articular cartilage at different implantation sites in these models is limited. Design To identify the most suitable site for experimental surgery, cartilage thickness at the medial femoral condyle (MFC), lateral femoral condyle (LFC), and trochlea in ovine, caprine, and porcine cadaver stifle joints was systematically measured using hematoxylin-eosin staining of 6 µm paraffin sections and software-based image analysis. Results Regarding all ventral-dorsal regions of the MFC, goat showed the thickest articular cartilage (maximal mean thickness: 1299 µm), followed by sheep (1096 µm) and mini-pig (604 µm), with the highest values in the most ventral and dorsal regions. Also for the LFC, the most ventral regions showed the thickest cartilage in goat (maximal mean thickness: 1118 µm), followed by sheep (678 µm) and mini-pig (607 µm). Except for the mini-pig, however, the cartilage thickness on the LFC was consistently lower than that on the MFC. The 3 species also differed along the transversal measuring points on the MFC and LFC. In contrast, there were no consistent differences for the regional cartilage thickness of the trochlea among goat and sheep (≥780 µm) and mini-pig (≤500 µm). Conclusions Based on their cartilage thickness, experimental defects on goat and sheep MFC may be viable options for preclinical cartilage repair studies, in addition to well-established horse models.

Si toda la vida en la Tierra comparte un ancestro común, con la evolución como mecanismo diversificando gradualmente a través del tiempo, entonces, el registro fósil debería proporcionar formas graduadas intermedias. Sin embargo, para 1859 (año de la publicación de El origen de las especies), éstas aún no habían sido descubiertas. Para Charles Darwin (1809-1882), esto representaba una seria objeción a su teoría evolutiva e intentó explicar esta evidencia negativa a través de la imperfección del registro fósil. Por lo tanto, la paleontología era la clave que podía presentar evidencia a favor de la evolución. Thomas Henry Huxley (1825-1895), hallaría formas de transición que unirían grandes grupos animales sin relación aparente, por ejemplo, las aves con los reptiles a través de los dinosaurios. El objetivo del presente trabajo fue llevar a cabo una investigación sobre la obra paleontológica de Thomas Huxley, haciendo un especial énfasis en su apoyo a las ideas evolutivas de Darwin. Se llegó a la conclusión de que su labor paleontológica demostró que los hechos de la paleontología, en lo que concierne a las aves y a los reptiles, no se oponen a la doctrina de la evolución, sino que, al contrario, eran muy parecidos a los que la doctrina nos llevaría a esperar.

The disconnect between preclinical and clinical results underscores the imperative for establishing good animal models, then gleaning all available data on efficacy, safety, and potential toxicities associated with a device or drug. Mini pigs are a commonly used animal model for testing orthopedic and dental devices because their skeletons are large enough to accommodate human-sized implants. The challenge comes with the analyses of their hard tissues: current methods are time-consuming, destructive, and largely limited to histological observations made from the analysis of very few tissue sections. We developed and employed cryo-based methods that preserved the microarchitecture and the cellular/molecular integrity of mini pig hard tissues, then demonstrated that the results of these histological, histochemical, immunohistochemical, and dynamic histomorphometric analyses e.g., mineral apposition rates were comparable with similar data from preclinical rodent models. Thus, the ability to assess static and dynamic bone states increases the translational value of mini pig and other large animal model studies. In sum, this method represents logical means to minimize the number of animals in a study while simultaneously maximizing the amount of information collected from each specimen.

Background A reliable large animal model of benign biliary stricture (BBS) is essential to study endoscopic management of BBS. The aim of this study was to establish a swine BBS model of endobiliary electrothermal injury with a diathermic sheath and screen out the optimal energy dose. Materials and methods Twelve swine were equally randomized into a low (20 W), a medium (30 W), and a high (40 W)-dose group. Endobiliary electrothermal injury was applied to the common bile duct using a diathermic sheath at different energy doses for 20 seconds via endoscopic retrograde cholangiopancreatography. Cholangiographic findings and liver function were evaluated weekly after thermal injury. Two animals from each group were sacrificed at 2 weeks and the other 2 sacrificed 4 weeks after thermal injury for histopathologic evaluation. Results BBS was established successfully in 10 of the 12 animals. Two of the 4 animals in low-dose group did not produce biliary stricture at 4 weeks; in medium-dose group, BBS was induced in both animals at 2 weeks without causing severe complications; and in high-dose group, BBS was produced in 4 animals at 2 weeks, causing perforation and abdominal abscess formation in 1 animal. Conclusions A safe and reproducible swine model of BBS could be established successfully by applying endobiliary electrothermal injury with a diathermic sheath at 30 W for 20 seconds.

Summary Objective Lubricin is increasingly being evaluated as an outcome measure in studies investigating post-traumatic and naturally occurring osteoarthritis. However, there are discrepancies in results, making it unclear as to whether lubricin is increased, decreased or unchanged in osteoarthritis. The purpose of this study was to review all papers that measured lubricin in joint injury or osteoarthritis in order to draw conclusions about lubricin regulation in joint disease. Design A systematic search of the Pubmed, Web of Knowledge, and EBSCOhost databases for papers was performed. Inclusion criteria were in vivo studies that measured lubricin in humans or animals with joint injury, that investigated lubricin supplementation in osteoarthritic joints, or that described the phenotype of a lubricin knock-out model. A methodological assessment was performed. Results Sixty-two studies were included, of which thirty-eight measured endogenous lubricin in joint injury or osteoarthritis. Nineteen papers found an increase or no change in lubricin and nineteen reported a decrease. Papers that reported a decrease in lubricin were cited four times more often than those that reported an increase. Fifteen papers described lubricin supplementation, and all reported a beneficial effect. Eleven papers described lubricin knock-out models. Conclusions The human literature reveals similar distributions of papers reporting increased lubricin as compared to decreased lubricin in osteoarthritis. The animal literature is dominated by reports of decreased lubricin in the rat anterior cruciate ligament transection model, whereas studies in large animal models report increased lubricin. Intra-articular lubricin supplementation may be beneficial regardless of whether lubricin increases or decreases in OA.

Ingestion of oral dosage forms with food can drastically change drug pharmacokinetic parameters to consumption in fasted state. Accurate prediction of food effect (FE) is an important focus during drug development, as well as a requirement for drug approval by the Food and Drug Administration. FE can significantly restrict the clinical usefulness of drugs and is a principal parameter that must be considered early in drug development. Several approaches are available to predict FE in the human, including cell culture models, a variety of small and large animal models, and, more recently, physiologically based pharmacokinetic computerized models that incorporate biorelevant drug physicochemical properties. Each has its own advantages and disadvantages. While many methods are available to study FE, not all of these methods are applicable, efficient, consistent, financially feasible, or reasonable for every drug or drug formulation. Most importantly, different models may offer different applicability in accurately predicting FE in human species. Drug development is a long and often expensive process. Understanding of and access to an appropriate, reproducible, frugal means of FE assessment is vital in the field of drug development in order to ensure the development of a safe and effective drug. The following review delineates the advantages and disadvantages of a variety of preclinical FE study methods. While no single approach is good enough to give completely reliable predictions, a combination of in vitro, in vivo, and in silico approach may be advantageous to predict FE.

Purpose of review To summarize the evolution of skin xenotransplantation and contextualize technological advances and the status of clinically applicable large animal research as well as prospects for translation of this work as a viable future treatment option. Recent findings Porcine xenografts at the start of the millennium were merely biologic dressings subject to rapid rejection. Since then, numerous important advances in swine to nonhuman primate models have yielded xenotransplant products at the point of clinical translation. Critical genetic modifications in swine from a designated pathogen-free donor herd have allowed xenograft survival reaching 30 days without preconditioning or maintenance immunosuppression. Further, xenograft coverage appears not to sensitize the recipient to subsequent allograft placement and vice versa, allowing for temporary coverage times to be doubled using both xeno and allografts. Summary Studies in large animal models have led to significant progress in the creation of living, functional skin xenotransplants with clinically relevant shelf-lives to improve the management of patients with extensive burns.

Treatment of medication‐related osteonecrosis of the jaw (MRONJ) is challenging and no clear consensus has been achieved. This study investigated preventive measures recommended for tooth extractions under antiresorptive (AR) treatment and the role of discontinuation of AR therapy to avoid the onset of MRONJ in a minipig model. Thirty‐six Göttingen minipigs were divided into four groups. Group 1 (negative control): tooth extractions but no zoledronate (ZOL). Group 2 (positive control): weekly ZOL infusions for 12 weeks followed by tooth extractions without wound management followed by 8 weeks of ZOL treatment. Group 3: weekly ZOL infusions for 12 weeks followed by tooth extractions; surgical wound management (resection of sharp bone edges, mucoperiosteal coverage); and continuation of ZOL infusions for 8 weeks plus antibiotic treatment. Group 4: 12 weeks of ZOL infusions followed by a drug holiday for 6 weeks. Tooth extractions with preventive wound management followed by antibiotic treatment for 8 weeks but no ZOL infusions. Jawbones were subjected to macroscopic, radiological (CT and micro‐CT) and histopathological investigations. No clinical cases of MRONJ were observed in the negative group, in the positive control all animals developed MRONJ. Group 3 developed MRONJ in 83% of cases. With a drug holiday, 40% developed MRONJ in areas of tooth extraction. This is the first large animal model that reduces the occurrence of MRONJ following tooth extraction by the implementation of a drug holiday combined with antibiotic prophylaxis and smoothening of sharp bony edges. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research..

Visual Abstract, Highlights • A fully biodegradable fetal valve was developed using a zinc-aluminum alloy stent and electrospun PCL leaflets. • In vitro evaluation of the valve was performed with accelerated degradation, mechanical, and flow loop testing, and the valve showed trivial stenosis and trivial regurgitation. • A large animal model was used for percutaneous delivery of the valve to the fetal pulmonary annulus. • Following implantation, the valve had no stenosis or regurgitation by echocardiography, and the fetal sheep matured and was delivered at term with the tissue-engineered valve., Summary This multidisciplinary work shows the feasibility of replacing the fetal pulmonary valve with a percutaneous, transcatheter, fully biodegradable tissue-engineered heart valve (TEHV), which was studied in vitro through accelerated degradation, mechanical, and hemodynamic testing and in vivo by implantation into a fetal lamb. The TEHV exhibited only trivial stenosis and regurgitation in vitro and no stenosis in vivo by echocardiogram. Following implantation, the fetus matured and was delivered at term. Replacing a stenotic fetal valve with a functional TEHV has the potential to interrupt the development of single-ventricle heart disease by restoring proper flow through the heart.

Purpose of Review Spinal pain and associated disability is a leading cause of morbidity worldwide that has a strong association with degenerative disc disease (DDD). Biologically based therapies to treat DDD face significant challenges posed by the unique milieu of the environment within the intervertebral disc, and many promising therapies are in the early stages of development. Patient selection, reasonable therapeutic goals, approach, and timing will need to be discerned to successfully translate potential therapeutics. This review provides a brief overview of the status of intradiscal biologic therapies. Recent Findings Proposed systemic delivery of therapeutic agents has not progressed very much in large part due to the risk of adverse events in remote tissues plus the very limited vascular supply and therefore questionable delivery to the intervertebral disc nucleus pulposus. Intradiscal delivery of therapeutic proteins shows good potential for clinical trials and translation with encouraging results from large animal pre-clinical studies plus an enhanced understanding of the biology of DDD. There are a few cell-based therapies currently under pre-clinical and clinical trial investigation; however, these attempts continue to be hampered by unknown if any, mechanism of action, no downstream detection of transplanted cells, mixed results concerning efficacy, small sample numbers, and a lack of objective evidence of pain mediation. Summary Treatment of DDD using biologically based therapeutics is a widely sought-after goal; however, potential therapies need to address pain and disability in larger, well-controlled studies.

In clinical practice, atrial fibrillation (AF) is the most common cardiac arrhythmia in humans and it may lead to numerous complications, including central nervous system embolism. The electrical activity of the heart in AF is rapid and chaotic, while the atrioventricular conduction leads to irregular ventricular contraction. Consequently, the stroke volume is reduced, which may lead to symptoms of heart failure. Heart failure is one of the causes of AF as well. Numerous in vivo and in vitro models are used to study the pathophysiology of AF. Animal models play a key role in understanding the mechanisms of arrhythmias as well as in developing treatment regimens. The models of AF include large animals (goats, sheep, pigs, dogs) as well as small laboratory animals. This study reviews the large animal models of AF, which enhance our understanding of numerous mechanisms responsible for the development of AF, but we must be aware that the pathomechanism of AF in humans is complex and is affected by numerous factors, including environmental and congenital ones.

Mapping the large neural networks of animal and human brains is a fundamental but so far elusive task, because of the massive amount of data and the consequent prohibitively long image taking and processing times. We developed an effective strategy called “AXON” (Accelerated X-ray Observation of Neurons) to solve this problem. AXON can achieve comprehensive whole-brain mapping within a reasonable time by combining fast image taking and processing, plus two other critical performances: three-dimensional (3D) imaging with high and isotropic spatial resolution, and multi-scale resolution. We successfully tested this strategy with coordinated experiments at four synchrotron facilities in Japan, Taiwan, Singapore and Korea on two animal models, Drosophila and mouse. Its performances notably allowed full 3D mapping of the Drosophila brain in a few days. With reasonable improvements, AXON can deliver full mapping of large animal and human brains on a realistic time scale of a few years.

Thalamic infusion of adeno-associated viral (AAV) vectors has been shown to have therapeutic effects in neuronopathic lysosomal storage diseases. Preclinical studies in sheep model of Tay-Sachs disease demonstrated that bilateral thalamic injections of AAV gene therapy are required for maximal benefit. Translation of thalamic injection to patients carries risks in that (1) it has never been done in humans, and (2) dosing scale-up based on brain weight from animals to humans requires injection of larger volumes. To increase the safety margin of this infusion, a flexible cannula was selected to enable simultaneous bilateral thalamic infusion in infants while monitoring by imaging and/or to enable awake infusions for injection of large volumes at low infusion rates. In this study, we tested various infusion volumes (200-800 μL) and rates (0.5-5 μL/min) to determine the maximum tolerated combination of injection parameters. Animals were followed for ∼1 month postinjection with magnetic resonance imaging (MRI) performed at 14 and 28 days. T1-weighted MRI was used to quantify thalamic damage followed by histopathological assessment of the brain. Trends in data show that infusion volumes of 800 μL (2 × the volume required in sheep based on thalamic size) resulted in larger lesions than lower volumes, where the long infusion times (between 13 and 26 h) could have contributed to the generation of larger lesions. The target volume (400 μL, projected to be sufficient to cover most of the sheep thalamus) created the smallest lesion size. Cannula placement alone did result in damage, but this is likely associated with an inherent limitation of its use in a small brain due to the length of the distal rigid portion and lack of stable fixation. An injection rate of 5 μL/min at a volume ∼1/3 of the thalamus (400-600 μL) appears to be well tolerated in sheep both clinically and histopathologically.

Objectives Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly being used to treat patients with refractory severe heart failure. Large animal models are developed to help understand physiology and build translational research projects. In order to better understand those experimental models, we conducted a systematic literature review of animal models combining heart failure and VA-ECMO. Studies selection A systematic review was performed using Medline via PubMed, EMBASE, and Web of Science, from January 1996 to January 2019. Animal models combining experimental acute heart failure and ECMO were included. Clinical studies, abstracts, and studies not employing VA-ECMO were excluded. Data extraction Following variables were extracted, relating to four key features: (1) study design, (2) animals and their peri-experimental care, (3) heart failure models and characteristics, and (4) ECMO characteristics and management. Results Nineteen models of heart failure and VA-ECMO were included in this review. All were performed in large animals, the majority (n = 13) in pigs. Acute myocardial infarction (n = 11) with left anterior descending coronary ligation (n = 9) was the commonest mean of inducing heart failure. Most models employed peripheral VA-ECMO (n = 14) with limited reporting. Conclusion Among models that combined severe heart failure and VA-ECMO, there is a large heterogeneity in both design and reporting, as well as methods employed for heart failure. There is a need for standardization of reporting and minimum dataset to ensure translational research achieve high-quality standards.

Various cell-based therapies are currently investigated in an attempt to tackle the high morbidity and mortality associated with heart failure. The need for these therapies to move towards the clinic is pressing. Therefore, preclinical large animal studies that use non-autologous cells are needed to evaluate their potential. However, non-autologous cells are highly immunogenic and trigger immune rejection responses resulting in potential loss of efficacy. To overcome this issue, adequate immunosuppressive regimens are of imminent importance but clear guidelines are currently lacking. In this review, we assess the immunological barriers regarding non-autologous cell transplantation and immune modulation with immunosuppressive drugs. In addition, we provide recommendations with respect to immunosuppressive regimens in preclinical cardiac cell-replacement studies.

Summary This study assessed the regional changes in myocardial geometry, microstructure, mechanical behavior, and properties that occur in response to progressive left ventricular pressure overload (LVPO) in a large animal model. Using an index of local biomechanical function at early onset of LVPO allowed for prediction of the magnitude of left ventricular chamber stiffness (Kc) and left atrial area at LVPO late timepoints. Our study found that LV myocardial collagen content alone was insufficient to identify mechanisms for LV myocardial stiffness with progression to heart failure with preserved ejection fraction (HFpEF). Serial assessment of regional biomechanical function might hold value in monitoring the natural history and progression of HFpEF, which would allow evaluation of novel therapeutic approaches.

This study aimed to characterize and evaluate normal temporomandibular joint (TMJ) of the Egyptian Baladi sheep anatomically andhistologically as a large animal model.Fifteenheads of adult apparently healthy male sheep(Ovis aries) were utilized for;macro- andmicroscopical examination.Also, bony preparations, radiology, computed tomography and scanning electron microscopy were achieved.The TMJ consisted of mandibular condyle of the mandible,glenoid fossa of temporal bone andarticular disc in-between.The mandibular condyle was flattened laterally, convex medially and slopped caudomedially.The glenoid fossa was elliptical in shape, concavoconvex from backward to forward.The disc was a smooth, elliptical plate,biconcave,thin centrally and thick peripherally with sloped end caudomedially.Histologically, the ?brocartilage layer of the condyle and glenoid fossa was differentiated into fourzones; fibrous, proliferative, hypertrophic, and calcificationzones.The?brocartilagenousdisc consisted of thick densely packed bundles of collagen fibers with chondrocytesin-between.The complex architecture of articular disc fibers wasrevealed by light and scanning electron microscopic examination. The collagen ?bers orientation was perpendicular in the anterior and posterior regions, and parallel anteroposterior in the central region.There were many anatomical similarities between sheep and human TMJ in; relations, size, shape, position of the disc,histological structureandsurgical approach. Furthermore, the sheep are more economic, available by large numbers, high ethical suitability,all this renders the sheep not only suitable but ideal choice as a large animal model over other animal models.

Cardiovascular disease is the leading cause of human mortality and disability worldwide, primarily due to myocardial infarction (MI) and the resultant heart failure. To address this, animal models of MI have been developed to better understand the pathophysiological process and to enable the discovery and development of new therapies. The most commonly used small and large mammal models of MI accurately reproduce histopathologically the four characteristic post-MI phases: cardiac cell death, inflammation, myocardial repair and remodelling. However, differences between the time of onset of each characteristic phase and the kinetics of various cellular reactions between human MI and animal models, and between animal models, require careful consideration when defining the variables to be analysed and the timepoints of assessment in experimental studies. Typically, the progression of the different phases post-MI occur more rapidly in rodent models compared with large-animal models and man, suggesting the use of large-animal models is more translational for studying human MI. This review provides an overview of the main anatomopathological features of small and large animal models of MI and discusses the key species-specific histopathological similarities and differences.

This study tested the hypothesis that (pyr)apelin-13 dose-dependently augments myocardial contractility and coronary blood flow, irrespective of changes in systemic hemodynamics. Acute effects of intravenous (pyr)apelin-13 administration (10 to 1,000 nM) on blood pressure, heart rate, left ventricular pressure and volume, and coronary parameters were measured in dogs and pigs. Administration of (pyr)apelin-13 did not influence blood pressure ( P = 0.59), dP/d tmax ( P = 0.26), or dP/d tmin ( P = 0.85) in dogs. However, heart rate dose-dependently increased > 70% ( P < 0.01), which was accompanied by a significant increase in coronary blood flow ( P < 0.05) and reductions in left ventricular end-diastolic volume and stroke volume ( P < 0.001). In contrast, (pyr)apelin-13 did not significantly affect hemodynamics, coronary blood flow, or indexes of contractile function in pigs. Furthermore, swine studies found no effect of intracoronary (pyr)apelin-13 administration on coronary blood flow ( P = 0.83) or vasorelaxation in isolated, endothelium-intact ( P = 0.89) or denuded ( P = 0.38) coronary artery rings. Examination of all data across (pyr)apelin-13 concentrations revealed an exponential increase in cardiac output as peripheral resistance decreased across pigs and dogs ( P < 0.001; R2 = 0.78). Assessment of the Frank-Starling relationship demonstrated a significant linear relationship between left ventricular end-diastolic volume and stroke volume across species ( P < 0.001; R2 = 0.70). Taken together, these findings demonstrate that (pyr)apelin-13 does not directly influence myocardial contractility or coronary blood flow in either dogs or pigs. NEW & NOTEWORTHY Our findings provide much needed insight regarding the pharmacological cardiac and coronary effects of (pyr)apelin-13 in larger animal preparations. In particular, data highlight distinct hemodynamic responses of apelin across species, which are independent of any direct effect on myocardial contractility or perfusion.

Hydrogen sulfide (H2 S), a high-threat chemical agent, occurs naturally in a variety of settings. Despite multiple incidents of exposures and deaths, no FDA-approved antidote exists. A rapid-acting, easy to administer antidote is needed. We conducted a randomized control trial in swine comparing intramuscular administration of aminotetrazole cobinamide (2.9 mL, 18 mg/kg) to no treatment following inhalation of H2 S gas. We found that aminotetrazole cobinamide administered 2 min after the onset of respiratory depression-defined as a tidal volume of less than 3 mL/kg for 2 consecutive minutes-yielded 100% survival, while all control animals died. Respiratory depression resolved in the treatment group within 3.6 ± 1.5 min (mean ± SD) of cobinamide administration, whereas control animals had intermittent gasping until death. Blood pressure and arterial oxygen saturation (SO2 ) returned to baseline values within 5 and 10 min, respectively, of cobinamide treatment, and plasma lactate concentration decreased to less than 50% of the highest value by the end of the experiment. In control animals, plasma lactate rose continuously until death. We conclude that intramuscular aminotetrazole cobinamide is effective in a large animal, inhalational model of acute, severe H2 S poisoning.

INTRODUCTION Spinal cord ischemia after cardiovascular interventions continues to be a devastating problem in modern surgery. The role of intraspinal vascular networks and anterior radiculomedullary arteries (ARMA) in preventing spinal cord ischemia is poorly understood. MATERIALS AND METHODS Landrace pigs (n = 30, 35.1 ± 3.9 kg) underwent a lateral thoracotomy. Fluorescent microspheres were injected into the left atrium and a reference sample was aspirated from the descending aorta. Repeated measurements of spinal cord and renal cortical blood flow from the left and right kidneys with three different microsphere colors in five pigs were taken to validate reproducibility. Spinal cord blood flow to the upper thoracic (T1-T4), mid-thoracic (T5-T8), lower thoracic (T9-T13), and lumbar (L1-L3) levels were determined. After euthanasia, we carried out selective vascular corrosion cast and counted the left and right ARMAs from levels T1-T13. RESULTS Blood flow analysis of the left and right kidneys revealed a strong correlation (r = .94, p

Animal models are a significant component of biomedical research and play an important role in translational studies. Traditionally, rodent models have been the mainstay and principal choice of researchers but in recent years, there have been significant changes in the landscape of animal modeling. For example, newer techniques have greatly expanded the use and successful application of large animal models such as pigs for translational studies. The evolving types and species of animal models can influence the research landscape in terms of facilities, expertise, reproducibility and funding streams, which creates new challenges for research studies. It is also important that investigators are prepared to address the necessity of their animal model research and capable to educate the public regarding its value.

Neurofibromatosis type 1 (NF1) is a rare, autosomal dominant disease with variable clinical presentations. Large animal models are useful to help dissect molecular mechanisms, determine relevant biomarkers, and develop effective therapeutics. Here, we studied a NF1 minipig model (NF1+/ex42del) for the first 12 months of life to evaluate phenotype development, track disease progression, and provide a comparison to human subjects. Through systematic evaluation, we have shown that compared to littermate controls, the NF1 model develops phenotypic characteristics of human NF1: [1] café-au-lait macules, [2] axillary/inguinal freckling, [3] shortened stature, [4] tibial bone curvature, and [5] neurofibroma. At 4 months, full body computed tomography imaging detected significantly smaller long bones in NF1+/ex42del minipigs compared to controls, indicative of shorter stature. We found quantitative evidence of tibial bowing in a subpopulation of NF1 minipigs. By 8 months, an NF1+/ex42del boar developed a large diffuse shoulder neurofibroma, visualized on magnetic resonance imaging, which subsequently grew in size and depth as the animal aged up to 20 months. The NF1+/ex42del minipig model progressively demonstrates signature attributes that parallel clinical manifestations seen in humans and provides a viable tool for future translational NF1 research.

Large scale unbiased quantification of immunohistochemistry (IHC) is time consuming, expensive, and/or limited in scope. Heterogeneous tissue types such as brain tissue have presented a further challenge to the development of automated analysis, as differing cellular morphologies result in either limited applicability or require large amounts of training tissue for machine-learning methods. Here we present the use of QuPath, a free and open source software, to quantify whole-brain sections stained with the immunohistochemical markers IBA1 and AT8, for microglia and phosphorylated tau respectively. The pixel-based method of analysis herein allows for statistical comparison of global protein expression between brains and generates heat-maps of stain intensity, visualizing stain signal across whole sections and permitting more specific investigation of regions of interest. This method is fast, automated, unbiased, and easily replicable. We compared swine brains that had undergone a closed head traumatic brain injury with brains of sham animals, and found a global increase in both microglial signal expression and phosphorylated tau. We discuss the IHC methods necessary to utilize this analysis and provide detailed instruction on the use of QuPath in the pixel-based analysis of whole-slide images.

The aim of the present systematic review was to analyse studies using inorganic implant coatings and, in a meta-analysis, the effect of specifically tricalcium phosphate (TCP) and hydroxyapatite (HA) implant surface coatings on bone formation according to the PRISMA criteria. Inclusion criteria were the comparison to rough surfaced titanium implants in large animal studies at different time points of healing. Forty studies met the inclusion criteria for the systematic review. Fifteen of these analyzed the bone-to-implant contact (BIC) around the most investigated inorganic titanium implant coatings, namely TCP and HA, and were included in the meta-analysis. The results of the TCP group show after 14 days a BIC being 3.48% points lower compared with the reference surface. This difference in BIC decreases to 0.85% points after 21-28 days. After 42-84 days, the difference in BIC of 13.79% points is in favor of the TCP-coatings. However, the results are not statistically significant, in part due to the fact that the variability between the studies increased over time. The results of the HA group show a significant difference in mean BIC of 6.94% points after 14 days in favor of the reference surface. After 21-28 days and 42-84 days the difference in BIC is slightly in favor of the test group with 1.53% points and 1.57% points, respectively, lacking significance. In large animals, there does not seem to be much effect of TCP-coated or HA-coated implants over uncoated rough titanium implants in the short term.

Objective Implanted cardiac pacemakers must be regularly replaced due to depleted batteries. A possible alternative is proposed by subcutaneous photovoltaic energy harvesting. The bodys reaction to an implant can cause device encapsulation. Potential changes in spectral light transmission of skin can inuence the performance of subcutaneous photovoltaic cells and has not yet been studied in large animal studies. Methods Subcutaneous implants measuring changes in the light reaching the implant were developed. Three pigs received those implants and were analyzed for seven weeks. Spectral measurements with known irradiation were performed to identify possible changes in the transparency of the tissues above the implant during the wound healing process. A histological analysis at the end of the trial investigated the skin tissue above the subcutaneous photovoltaic implants. Results The implants measured decreasing light intensity and shifts in the lights spectrum during the initial wound healing phase. In a later stage of tissue recovery, the implants measured a generally reduced light intensity compared to the healthy tissue after implantation. The spectral distribution of the measured light at the end of the trial was similar to the rst measurements. The histological analysis showed subcutaneous granulation tissue formation for all devices. Conclusion The varying reduction of light intensity reaching the implants means that safety margins must be sufciently high to ensure the power. At the end of the wound healing process, the spectral distribution of the light reaching the implant is similar to healthy tissue. Signicance: Optimizations of spectral sensitivity of photovoltaic cells are possible.

Pigs have been extensively used as the research models for human disease pathogenesis and gene therapy. They are also the optimal source of cells, tissues, and organs for xenotransplantation due to anatomical and physiological similarities to humans. Several breakthroughs in gene-editing technologies, including the advent of clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated 9 (Cas9), have greatly improved the efficiency of genetic manipulation and significantly broadened the application of gene-edited large animal models. In this review, we have not only outlined the important applications of the CRISPR/Cas9 system in pigs as a means to study human diseases but also discussed the potential challenges of the use of CRISPR/Cas9 in large animals.

When a virus spreads, it may mutate into, e.g., vaccine resistant or fast spreading lineages, as was the case for the Danish Cluster-5 mink variant (belonging to the B.1.1.298 lineage), the British B.1.1.7 lineage, and the South African B.1.351 lineage of the SARS-CoV-2 virus. A way to handle such spreads is through a containment strategy, where the population in the affected area is isolated until the spread has been stopped. Under such circumstances, it is important to monitor whether the mutated virus is extinct via massive testing for the virus sub-type. If successful, the strategy will lead to lower and lower numbers of the sub-type, and it will eventually die out. An important question is, for how long time one should wait to be sure the sub-type is extinct? We use a hidden Markov model for infection spread and an approximation of a two stage sampling scheme to infer the probability of extinction. The potential of the method is illustrated via a simulation study. Finally, the model is used to assess the Danish containment strategy when SARS-CoV-2 spread from mink to man during the summer of 2020, including the Cluster-5 sub-type. In order to avoid further spread and mink being a large animal virus reservoir, this situation led to the isolation of seven municipalities in the Northern part of the country, the culling of the entire Danish 17 million large mink population, and a bill to interim ban Danish mink production until the end of 2021. When a virus spreads, it may mutate into, e.g., vaccine resistant or fast spreading lineages, as was the case for the Danish Cluster-5 mink variant (belonging to the B.1.1.298 lineage), the British B.1.1.7 lineage, and the South African B.1.351 lineage of the SARS-CoV-2 virus. A way to handle such spreads is through a containment strategy, where the population in the affected area is isolated until the spread has been stopped. Under such circumstances, it is important to monitor whether the mutated virus is extinct via massive testing for the virus sub-type. If successful, the strategy will lead to lower and lower numbers of the sub-type, and it will eventually die out. An important question is, for how long time one should wait to be sure the sub-type is extinct? We use a hidden Markov model for infection spread and an approximation of a two stage sampling scheme to infer the probability of extinction. The potential of the method is illustrated via a simulation study. Finally, the model is used to assess the Danish containment strategy when SARS-CoV-2 spread from mink to man during the summer of 2020, including the Cluster-5 sub-type. In order to avoid further spread and mink being a large animal virus reservoir, this situation led to the isolation of seven municipalities in the Northern part of the country, the culling of the entire Danish 17 million large mink population, and a bill to interim ban Danish mink production until the end of 2021.

Considerable progress has been made with the development of culture systems for the in vitro growth and maturation (IVGM) of oocytes from the earliest-staged primordial follicles and from the more advanced secondary follicles in rodents, ruminants, nonhuman primates, and humans. Successful oocyte production in vitro depends on the development of a dynamic culture strategy that replicates the follicular microenvironment required for oocyte activation and to support oocyte growth and maturation in vivo while enabling the coordinated and timely acquisition of oocyte developmental competence. Significant heterogeneity exists between the culture protocols used for different stages of follicle development and for different species. To date, the fertile potential of IVGM oocytes derived from primordial follicles has been realized only in mice. Although many technical challenges remain, significant advances have been made, and there is an increasing consensus that complete IVGM will require a dynamic, multiphase culture approach. The production of healthy offspring from in vitro-produced oocytes in a secondary large animal species is a vital next step before IVGM can be tested for therapeutic use in humans. Expected final online publication date for the Annual Review of Animal Biosciences, Volume 10 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Despite improved prevention, diagnosis and treatment methods, heart disease caused by lack of oxygen remains the leading cause of morbidity and mortality worldwide. This thesis focuses on new interventions and treatment options to prevent ischemic induced heart failure. Specifically, treatments linked to processes that contribute to cardiac remodeling, namely cell death, inflammatory responses and fibrosis formation. As well-designed preclinical studies are very important for getting new therapies to the patient, large animal models have been used in these studies and extra attention was paid to immunosuppresive regimens for xenogenic cell transplantation. The work presented in this thesis will assist further development of novel therapies for the prevention of ischemic heart failure.

Bioelectronic interfaces have been extensively investigated in recent years and advances in technology derived from these tools, such as soft and ultrathin sensors, now offer the opportunity to interface with parts of the body that were largely unexplored due to the lack of suitable tools. The musculoskeletal system is an understudied area where these new technologies can result in advanced capabilities. Bones as a sensor and stimulation location offer tremendous advantages for chronic biointerfaces because devices can be permanently bonded and provide stable optical, electromagnetic, and mechanical impedance over the course of years. Here we introduce a new class of wireless battery-free devices, named osseosurface electronics, which feature soft mechanics, ultra-thin form factor and miniaturized multimodal biointerfaces comprised of sensors and optoelectronics directly adhered to the surface of the bone. Potential of this fully implanted device class is demonstrated via real-time recording of bone strain, millikelvin resolution thermography and delivery of optical stimulation in freely-moving small animal models. Battery-free device architecture, direct growth to the bone via surface engineered calcium phosphate ceramic particles, demonstration of operation in deep tissue in large animal models and readout with a smartphone highlight suitable characteristics for exploratory research and utility as a diagnostic and therapeutic platform., The development of high-performance implantable soft electronics as diagnostic platforms is key to realizing improved health monitoring. Here, the authors design wireless, battery-free, implantable bioelectronics that interface with the osseosurface for chronic musculoskeletal system monitoring.

Pathogenic variants in retinol dehydrogenase 5 (RDH5) attenuate supply of 11-cis-retinal to photoreceptors leading to a range of clinical phenotypes including night blindness because of markedly slowed rod dark adaptation and in some patients, macular atrophy. Current animal models (such as Rdh5−/− mice) fail to recapitulate the functional or degenerative phenotype. Addressing this need for a relevant animal model we present a new domestic cat model with a loss-of-function missense mutation in RDH5 (c.542G > T; p.Gly181Val). As with patients, affected cats have a marked delay in recovery of dark adaptation. In addition, the cats develop a degeneration of the area centralis (equivalent to the human macula). This recapitulates the development of macular atrophy that is reported in a subset of patients with RDH5 mutations and is shown in this paper in seven patients with biallelic RDH5 mutations. There is notable variability in the age at onset of the area centralis changes in the cat, with most developing changes as juveniles but some not showing changes over the first few years of age. There is similar variability in development of macular atrophy in patients and while age is a risk factor, it is hypothesized that genetic modifying loci influence disease severity, and we suspect the same is true in the cat model. This novel cat model provides opportunities to improve molecular understanding of macular atrophy and test therapeutic interventions for RDH5-associated retinopathies.

Anterior cruciate ligament (ACL) injuries are increasingly common in adolescents, and injuries in this age group are associated with many unique challenges. Recent large animal studies suggest that the size and function of the major bundles of the ACL change differently throughout skeletal growth. To better aid clinical treatment of pediatric partial ACL tears and better predict outcomes from age-specific treatments, there is a need to measure changes in ACL bundle size in humans during growth. As such, the objective of this study was to compare changes in the length and cross-sectional area of the ACL and its primary bundles in adolescent human subjects. MRI scans were analyzed to determine the visibility and integrity of the ACL and its anteromedial and posterolateral bundles. MRI scans were considered from a retrospective database of subjects ranging from 10-18 years of age. The ACL and its anteromedial and posterolateral bundles were segmented and reconstructed into 3D models, and length and cross-sectional area (CSA) were calculated. Total ACL length and CSA were greater in males compared to females, with a statistically significant interaction between age and sex for CSA. Sex had a significant effect on the CSA of both bundles. Interestingly, these sex dependent differences emerge with moderate to large effect sizes (range: d=0.50 to d=1.23) beginning around 13 years of age. With considerations of ACL bundle structure-function relationships previously established in preclinical animal models, these findings may point towards biomechanical changes in the adolescent human ACL.

Background: Neonatal hypoxic brain injury is a major cause of intellectual and developmental disability. Hypoxia causes neuronal dysfunction and death in the developing cerebral cortex due to excitotoxic Ca2+-influx. In the translational piglet model of hypoxic encephalopathy, we have previously shown that hypoxia overactivates Ca2+/Calmodulin (CaM) signaling via Sarcoma (Src) kinase in cortical neurons, resulting in overexpression of proapoptotic genes. However, identifying the exact relationship between alterations in neuronal Ca2+-influx, molecular determinants of cell death, and the degree of hypoxia in a dynamic system represents a significant challenge. Methods: We used experimental and computational methods to identify molecular events critical to the onset of excitotoxicity-induced apoptosis in the cerebral cortex of newborn piglets. We used 2-3 day-old piglets (normoxic [Nx], hypoxic [Hx], and hypoxic + Src-inhibitor-treatment [Hx+PP2]groups) for biochemical analysis of ATP production, Ca2+-influx, and Ca2+/CaM-dependent protein kinase kinase 2(CaMKK2) expression. We then used SimBiology to build a computational model of the Ca2+/CaM-Src-kinase signaling cascade, simulating Nx, Hx, and Hx+PP2 conditions. To evaluate our model, we used Sobol variance decomposition, multiparametric global sensitivity analysis, and parameter scanning.Results: Our model captures important molecular trends caused by hypoxia in the piglet brain. Incorporating the action of Src kinase inhibitor PP2 further validated our model and enabled predictive analysis of the effect of hypoxia on CaMKK2. We determined the impact of a feedback loop related to Src phosphorylation of NMDA receptors and activation kinetics of CaMKII. We also identified distinct modes of signaling wherein Ca2+ level alterations following Src kinase inhibition may not be a linear predictor of changes in Bax expression. Importantly, our model indicates that while pharmacological pre-treatment significantly reduces the onset of abnormal Ca2+-influx, there exists a window of intervention after hypoxia during which targeted modulation of Src-NMDAR interaction kinetics in combination with PP2 administration can reduce Ca2+-influx and Bax expression to similar levels as pre-treatment. Conclusions: Our model identifies new dynamics of critical components in the Ca2+/CaM-Src signaling pathway leading to neuronal injury and provides an essential framework for drug efficacy studies in translational models of neonatal brain injury for the prevention of intellectual and developmental disabilities.

The tumor-immune interplay represents a dynamic series of events executed by cellular and soluble participants that either promote or inhibit successful tumor formation and growth. Throughout a tumor’s development and progression, the host organism’s immune system reacts by generating anti-cancer defenses through various incremental and combinatorial mechanisms, and this reactive orchestration is termed the cancer-immunity cycle. Success or failure of the cancer-immunity cycle dictates the fate of both host and tumor as winner or loser. Insights into how the tumor and host immune system continuously adapt to each other throughout the lifecycle of the tumor is necessary to rationally develop new effective immunotherapies. Additionally, the evolving nature of the cancer-immunity cycle necessitates therapeutic agility, requiring real-time serial assessment of immunobiologic markers that permits tailoring of therapies to the everchanging tumor immune microenvironment. In order to accelerate advances in the field of immuno-oncology, this review summarizes the steps comprising the cancer-immunity cycle, and underscores key breakpoints in the cycle that either favor cancer regression or progression, as well as shaping of the tumor microenvironment and associated immune phenotypes. Furthermore, specific large animal models of spontaneous cancers that are deemed immunogenic will be reviewed and proposed as unique resources for validating investigational immunotherapeutic protocols that are informed by the cancer-immunity cycle. Collectively, this review will provide a progressive look into the dynamic interplay between tumor and host immune responses and raise awareness for how large animal models can be included for developing combinatorial and sequenced immunotherapies to maximizing favorable treatment outcomes.

Atrial fibrillation (AF) is the most common sustained form of cardiac arrhythmia occurring in humans. Its effective treatment requires a detailed understanding of the underlying mechanisms at the genetic, molecular, cellular, tissue and organ levels. To study the complex mechanisms underlying the development, maintenance and termination of cardiac arrhythmias, we need preclinical research models. These models range from in vitro cell cultures to in vivo small and large animal hearts. However, translational research requires that the results of these animal experiments are understood in the context of human subjects. Currently, this is achieved through simulations with state-of-the-art mathematical models for human and animal heart tissue. In the context of AF, a model that is extensively used by experimentalists, is that of the pig atria. However, until now, an ionically detailed mathematical model for pig atrial tissue has been lacking, and researchers have been forced to rely on mathematical models from other animal species to understand their experimental observations.In this paper, we present the first ionically detailed mathematical model of porcine atrial electrophysiology. To build the model, we first fitted experimental patch-clamp data from literature to describe the individual currents flowing across the cell membrane. Later, we fine-tuned the model by fitting action potential duration restitution (APDR) curves for different repolarisation levels. The experimental data for the APDR studies was produced in N. Voigt’s lab.We extended our model to the tissue level and demonstrated the ability to maintain stable spiral waves. In agreement with previous experimental results, our model shows that early repolarisation is primarily driven by a calcium-mediated chloride current, IClCa, which is completely inactivated at high pacing frequencies. This is a condition found only in porcine atria. The model shows spatiotemporal chaos with reduced repolarisation.Author summaryState-of-the-art mathematical models of cardiac electrophysiology play an important role in bridging the gap between animal research conducted in the laboratory and preclinical research being considered for translation into the clinic. Using computer simulations, these models enable detailed studies of the behaviour of ion channels and ion transfer at the cellular level, the propagation of electrical waves at the tissue level and the visualisation of the excitation pattern within the heart wall at the organ level. Thus, they contribute to a better understanding of the mechanisms underlying cardiac arrhythmias.Here, we present the first ionically detailed mathematical model for porcine atrial electrophysiology. The individual membrane currents were modelled by fitting experimental data obtained from literature. The overall electrical response of the tissue was adjusted by fitting action potential duration restitution (APDR) curves obtained from in-house patch-clamp measurements. Our model accounts for an early repolarisation phase of the AP that is primarily Ca2+-dependent, a feature that is consistent with experiments and is identified to be unique to pigs. In extended media, our model is capable of sustaining stable spiral waves, and spatiotemporal chaos, when the repolarisation reserve is reduced.

Estimates of abundance and occupancy are essential for wildlife management, particularly for species of conservation concern such as eastern spotted skunks Spilogale putorius. Most studies of eastern spotted skunks rely on limited evidence for best monitoring practices, and while many studies use attractants to increase detections, previous studies have not tested attractants against a control of no attractant to determine their effectiveness. We tested two common attractants (sardines and fatty acid tablets) and one uncommon attractant (wild boar carcasses) against a control of no attractant to determine if any attractant increased detections of eastern spotted skunks or changed their temporal activity. Based on our model, sardines and wild boar carcasses improved detections by three and eight times that of the control, respectively. Further, for every 100 trap nights, we detected eastern spotted skunks 10.67 times with wild boar carcasses, 1.02 times with sardines, 0.53 times with fatty acid tablets and 0.44 times with no attractant. Wild boar carcasses also substantially decreased latency to detection, with skunks detected two times faster than at other attractants and almost three times faster than at the control. Eastern spotted skunks were most active in the early morning before sunrise, and their temporal activity did not vary significantly by attractant. This study is the first to use an experimental framework to test attractants for eastern spotted skunks, and our results showed that choice of attractant matters. Large animal carcasses, although rarely used, may be most effective for detecting eastern spotted skunks, while fatty acid tablets were no different than the control, and we recommend against their use in future studies. Monitoring plans should incorporate our results as increasing detections is essential to understanding the abundance, range and demographics of eastern spotted skunks.

Background Large animal models of acute myocardial infarction (MI) offer an important platform to test novel therapies. Consistency of infarct size between animals is critical to ensure an accurate assessment of therapies against control. However, anatomical variation challenges the ability to achieve a consistent infarct size and care must be taken to respect the principles of the 3Rs through minimisation of interventional fatalities. Purpose To standardise the approach of a closed chest model of balloon occlusion-facilitated MI. Novel 3-dimensional quantitative coronary angiography (3DQCA) software has been used retrospectively to identify a correlation between coronary volume occlusion and the extension of the myocardial scar. Methods Twenty-four Yorkshire pigs (mean weight 63.1±3 kg) underwent a closed chest MI model via percutaneous occlusion of the mid portion of the left anterior descending artery (LAD) for 60 minutes. The evaluation of the myocardial damage was obtained via cardiac magnetic resonance imaging (CMR) between 24 and 48 hours after the MI model (Acute) and at 4–5 weeks after MI (Chronic). Troponin I was also measured at multiple timepoints. 3DQCA reconstruction (QAngio XA 3D, Medis medical imaging systems NL) was generated from 2 angiographic projections with segmental analysis of all 3 major epicardial vessels including lumen volume, reference diameters, and segment length. The occlusive volume and vessel length was identified through co-registration of balloon position. Results At the short term timepoint, a significant correlation was found between the LAD volume occluded and the scar size as percentage of the LV mass (Spearman correlation 0.72, p value 20% (Fig. 2). At chronic phase the correlation between these two variables was not significant, although there was a trend towards significance (p value = 0.06, Cor = 0.54). No significant correlation was found with serum Troponin I. Conclusions There is a significant correlation between the LAD volume occluded and the overall scar size in the acute phase and at least 32.8% of the LAD volume should be occluded to determine a scar volume >20% of the entire LV. This indicates that a prospective measure of occluded LAD volume might minimise the intra-experimental variability in studies aiming to reduce infarct size and acute myocardial injury. Funding Acknowledgement Type of funding sources: Other. Main funding source(s): This research work was supported by grants awarded to Professor Ascione: the British Heart Foundation (BHF) (BHF IG/14/2/30991, BHF RM/13/2/30158), and the Medical Research Council (MRC) (MRC MR/L012723/1).

Preclinical testing in animal model is a required stage of vascular device development. Among small animal models, rabbits provide vasculature with relative larger caliber for anastomotic implantation of vascular grafts as preclinical testing before conducting large animal studies. Rabbits have similar hemostatic mechanism with human and can accommodate vascular grafts with various diameters at different locations, and thus provide a valid model to assess small-diameter vascular grafts. This chapter will describe the procedures and materials required to conduct survival surgery in rabbit carotid artery models for implantation of small-diameter tubular grafts with an end-to-side and end-to-end anastomotic technique.