ACVIM Consensus Statement on the management of status epilepticus and cluster seizures in dogs and cats

BACKGROUND

Seizure emergencies (ie, status epilepticus [SE] and cluster seizures [CS]), are common challenging disorders with complex pathophysiology, rapidly progressive drug-resistant and self-sustaining character, and high morbidity and mortality. Current treatment approaches are characterized by considerable variations, but official guidelines are lacking.

OBJECTIVES

To establish evidence-based guidelines and an agreement among board-certified specialists for the appropriate management of SE and CS in dogs and cats.

ANIMALS

None.

MATERIALS AND METHODS

A panel of 5 specialists was formed to assess and summarize evidence in the peer-reviewed literature with the aim to establish consensus clinical recommendations. Evidence from veterinary pharmacokinetic studies, basic research, and human medicine also was used to support the panel's recommendations, especially for the interventions where veterinary clinical evidence was lacking.

RESULTS

The majority of the evidence was on the first-line management (ie, benzodiazepines and their various administration routes) in both species. Overall, there was less evidence available on the management of emergency seizure disorders in cats in contrast to dogs. Most recommendations made by the panel were supported by a combination of a moderate level of veterinary clinical evidence and pharmacokinetic data as well as studies in humans and basic research studies.

CONCLUSIONS AND CLINICAL RELEVANCE

Successful management of seizure emergencies should include an early, rapid, and stage-based treatment approach consisting of interventions with moderate to preferably high ACVIM recommendations; management of complications and underlying causes related to seizure emergencies should accompany antiseizure medications.

Glioma with cribriform plate involvement in 6 dogs

Distinct patterns of local infiltration are a common feature of canine oligodendroglioma and astrocytoma, and typically involve the surrounding neuroparenchyma, ventricles, or leptomeninges. Infiltration of adjacent extraneural sites is rare and has not been well documented in veterinary medicine. Here we describe 6 canine gliomas with cribriform plate involvement (compression or infiltration) and caudal nasal invasion confirmed by neuroimaging, autopsy, and/or histology. All affected dogs were adults (9-12-y-old), and 3 were brachycephalic. Clinical signs were associated with the brain tumor, with no respiratory signs reported. Magnetic resonance imaging in 2 patients revealed a rostral intraparenchymal telencephalic mass with extension into the cribriform plate. All dogs were euthanized. Gross changes consisted of poorly demarcated, white or pale-yellow, soft, and, in oligodendrogliomas, gelatinous, intraparenchymal masses that expanded the rostral portions of the telencephalon and adhered firmly to the ethmoid bone and cribriform plate. Gliomas were classified as high-grade oligodendrogliomas (4 cases) and high-grade astrocytomas (2 cases) based on histology and immunohistochemistry for OLIG2 and GFAP. In all cases, there was evidence of cribriform plate invasion and, in one case, additional invasion of the caudal nasal cavity.

Magnetic resonance imaging characteristics of atlanto-axial subluxation in 42 dogs: Analysis of joint cavity size, subluxation distance, and craniocervical junction anomalies

Background

Atlanto-axial (AA) subluxation can be a complex syndrome in dogs. Accurate identification and assessment of this condition are key to providing treatment and resolution.

Aim

The purpose of this retrospective study was to describe the magnetic resonance imaging (MRI) characteristics of AA subluxation and associated neurologic deficits.

Methods

A multicenter review of dogs with a diagnosis of AA subluxation was conducted, evaluating signalment, neurologic grade, duration of signs, and MRI characteristics. MRI characteristics included degree of spinal cord compression and joint subluxation, integrity of odontoid ligaments, presence of a dens, spinal cord signal intensity, and presence of syringohydromyelia, hydrocephalus, and Chiari-like malformation. A control population with normal AA joints was also evaluated. MR images of 42 dogs with AA subluxation were compared to 26 age and breed-matched control dogs.

Results

Affected dogs had a median age of 27 months and a median weight of 2.7 kg, and the most commonly affected breed was the Yorkshire terrier (47.5%). Spinal cord signal hyperintensity, increased AA joint size, and cross-sectional cord compression at the level of the dens and mid-body C2 were associated with AA subluxation. No associations were found between cord compression, the appearance of the dens, or cord signal intensity and neurologic grade. Affected dogs did not have a higher incidence of Chiari-like malformation, syringohydromyelia, or hydrocephalus than control dogs, and their neurologic grade was not associated with MRI findings. Lack of dens and/or odontoid ligaments was associated with larger subluxations.

Conclusion

Dogs with clinical signs of AA subluxation were significantly more likely to have intramedullary hyperintensity at the level of compression ( p = 0.0004), an increased AA joint cavity size ( p = 0.0005), and increased spinal cord compression at the level of dens and mid-body C2 (p ≤ 0.05). The authors suggest an AA joint cavity size >1.4 mm and a subluxation distance >2.5 mm as cutoffs for MRI diagnosis of AA subluxation in dogs. No differences were noted between dogs with AA subluxation and control dogs regarding syringohydromyelia, hydrocephalus, and Chiari-like malformation.

Multiplex analysis of cytokines in the cerebrospinal fluid of dogs after ischemic stroke reveals elevations in chemokines CXCL1 and MCP-1

Introduction

Neuroinflammation that occurs in the brain after stroke has been shown to be important to disease pathogenesis and outcomes. The aim of this study was to evaluate a large number of pro- and anti-inflammatory cytokines in dogs with clinically-confirmed, naturally occurring stroke.

Materials and methods

Fifteen dogs with a clinical diagnosis of ischemic stroke and ten healthy control dogs were included in the study. A multiplex immunoassay was utilized to evaluate cerebrospinal fluid for GM-CSF, IFN-γ, IL-2, IL-4, IL-6, IL-7, IL-8, IL-10, IL-15, IL-18, IP-10, CXCL1, MCP-1, and TNF-α.

Results

Mean concentrations of CXCL1 (stroke-436 pg/ml, control-267 pg/ml, p = 0.01) and MCP-1 (stroke-196 pg/ml, control-66 pg/ml, p ≤ 0.0001) were significantly elevated in dogs with stroke when compared with control dogs. Location and type of infarct, duration of clinical signs, and use of anti-inflammatory medications were not associated with differences in cytokine concentration.

Discussion

CXCL1 and MCP-1 may play a role in naturally occurring canine stroke and represent targets for future research.

Tanshinone IIA-loaded nanoparticles and neural stem cell combination therapy improves gut homeostasis and recovery in a pig ischemic stroke model

Impaired gut homeostasis is associated with stroke often presenting with leaky gut syndrome and increased gut, brain, and systemic inflammation that further exacerbates brain damage. We previously reported that intracisternal administration of Tanshinone IIA-loaded nanoparticles (Tan IIA-NPs) and transplantation of induced pluripotent stem cell-derived neural stem cells (iNSCs) led to enhanced neuroprotective and regenerative activity and improved recovery in a pig stroke model. We hypothesized that Tan IIA-NP + iNSC combination therapy-mediated stroke recovery may also have an impact on gut inflammation and integrity in the stroke pigs. Ischemic stroke was induced, and male Yucatan pigs received PBS + PBS (Control, n = 6) or Tan IIA-NP + iNSC (Treatment, n = 6) treatment. The Tan IIA-NP + iNSC treatment reduced expression of jejunal TNF-α, TNF-α receptor1, and phosphorylated IkBα while increasing the expression of jejunal occludin, claudin1, and ZO-1 at 12 weeks post-treatment (PT). Treated pigs had higher fecal short-chain fatty acid (SCFAs) levels than their counterparts throughout the study period, and fecal SCFAs levels were negatively correlated with jejunal inflammation. Interestingly, fecal SCFAs levels were also negatively correlated with brain lesion volume and midline shift at 12 weeks PT. Collectively, the anti-inflammatory and neuroregenerative treatment resulted in increased SCFAs levels, tight junction protein expression, and decreased inflammation in the gut.

"I'd never have that operation again" - a mixed-methods study on how patients react to adverse outcomes following foot and ankle surgery

BACKGROUND

Adverse outcomes arising from foot and ankle surgery, including lack of pain relief, increased disability and perioperative complications are infrequent but inevitable. This mixed-methods study aims to explore the impact of adverse outcomes on patients following nonemergent foot and ankle surgery.

METHODS

Patients who underwent foot and ankle surgery over a two-year period were invited to participate in this study if they reported an adverse outcome. Qualitative assessment consisted of individual semi-structured interviews, designed to explore the decision they made to have surgery and the impact of the outcome after surgery. Quantitative assessment was performed using questionnaires on demographics, current analgesia, foot pain, health-related quality of life, psychological health, and regret.

RESULTS

Twelve participants (eight women) consented for inclusion in this study. Current foot pain was high in 10 participants, five met the criteria for central sensitisation syndrome and two had clinically significant pain catastrophising. Most participants regretted their decision to have surgery. The three major themes identified were expectations, communication, and alternatives.

CONCLUSIONS

Self-reported adverse outcomes following foot and ankle surgery were prevalent and participants in this study consistently complained of persistent pain. Regret was common and reasons cited for their adverse outcomes centred around the feelings of inadequate communication and failure to meet expectations.

Tanshinone IIA-Loaded Nanoparticle and Neural Stem Cell Therapy Enhances Recovery in a Pig Ischemic Stroke Model

Induced pluripotent stem cell-derived neural stem cells (iNSCs) are a multimodal stroke therapeutic that possess neuroprotective, regenerative, and cell replacement capabilities post-ischemia. However, long-term engraftment and efficacy of iNSCs is limited by the cytotoxic microenvironment post-stroke. Tanshinone IIA (Tan IIA) is a therapeutic that demonstrates anti-inflammatory and antioxidative effects in rodent ischemic stroke models and stroke patients. Therefore, pretreatment with Tan IIA may create a microenvironment that is more conducive to the long-term survival of iNSCs. In this study, we evaluated the potential of Tan IIA drug-loaded nanoparticles (Tan IIA-NPs) to improve iNSC engraftment and efficacy, thus potentially leading to enhanced cellular, tissue, and functional recovery in a translational pig ischemic stroke model. Twenty-two pigs underwent middle cerebral artery occlusion (MCAO) and were randomly assigned to a PBS + PBS, PBS + iNSC, or Tan IIA-NP + iNSC treatment group. Magnetic resonance imaging (MRI), modified Rankin Scale neurological evaluation, and immunohistochemistry were performed over a 12-week study period. Immunohistochemistry indicated pretreatment with Tan IIA-NPs increased iNSC survivability. Furthermore, Tan IIA-NPs increased iNSC neuronal differentiation and decreased iNSC reactive astrocyte differentiation. Tan IIA-NP + iNSC treatment enhanced endogenous neuroprotective and regenerative activities by decreasing the intracerebral cellular immune response, preserving endogenous neurons, and increasing neuroblast formation. MRI assessments revealed Tan IIA-NP + iNSC treatment reduced lesion volumes and midline shift. Tissue preservation and recovery corresponded with significant improvements in neurological recovery. This study demonstrated pretreatment with Tan IIA-NPs increased iNSC engraftment, enhanced cellular and tissue recovery, and improved neurological function in a translational pig stroke model.

Are models of plantar heel pain suitable for competitive runners? A narrative review

Background

Plantar heel pain (PHP), or plantar fasciopathy, is a common condition in active and sedentary populations, contributing to short- and long-term reductions in quality of life. The condition's aetiology and pathophysiology are the subjects of a significant body of research. However, much of this research has been conducted with sedentary participants, and comparatively little research exists in a population of highly-trained athletes focused on performance outcomes. Models for PHP and proposed mechanisms, such as high body mass index or systemic disease, are mostly absent from an athletic population. Even less is known about the origins of pain in PHP. Pain is believed to be a complex multifactorial process and may be experienced differently by sedentary and highly active populations, particularly endurance athletes. Consequently, conservative through to surgical treatment for athletes is informed by literature for a different population, potentially hindering treatment outcomes.

Aims

The aim of this review, therefore, is to summarise what is known about PHP in athletic populations and propose potential directions for future research.

Methods

Embase, PubMed, and Scopus using MeSH search terms for PHP and competitive sport and common synonyms.

Discussion

Two explanatory models for PHP were found. These primarily propose mechanical factors for PHP. It remains unclear how gait, body composition, and psychological factors may differ in an athletic population with and without PHP. Therefore, research in these three areas is needed to inform clinical and training interventions for this population.

Pain catastrophising, body mass index and depressive symptoms are associated with pain severity in tertiary referral orthopaedic foot/ankle patients

Introduction

Patients with chronic foot/ankle pain are often referred for orthopaedic assessment. Psychological vulnerabilities influence pain states (including foot and ankle), therefore this study aimed to establish the prevalence and relative importance of compromised psychological health to perceived foot/ankle pain severity in people referred to an orthopaedic foot and ankle clinic with non-urgent presentations.

Methods

Patients with triaged non-urgent foot/ankle referrals to the Department of Orthopaedics at Gold Coast University Hospital were recruited over a 12-month period and completed the Manchester-Oxford Foot and Ankle Questionnaire which was the primary measure. Participants also completed questionnaires assessing their anthropometric, demographic and health characteristics (Self-Administered Comorbidity Questionnaire) as well as measures of health-related quality of life (EuroQol-5-Dimensions-5-Level Questionnaire and EQ Visual Analogue Scale) and psychological health (Center for Epidemiological Studies-Depression scale, Pain Catastrophizing Scale and Central Sensitization Inventory). Descriptive statistics were used to summarise participant characteristics and a hierarchical multiple linear regression was employed to establish the extent to which psychological variables explain additional variance in foot/ankle pain severity beyond the effects of participant characteristics (age, sex, body mass index (BMI)).

Results

One hundred and seventy-two adults were recruited ((64.0% female), median (IQR) age 60.9 (17.7) years and BMI 27.6 (7.5) kg/m²). Specific psychological comorbidities were prevalent including depressive symptoms (48%), central sensitisation (38%) and pain catastrophising (24%). Age, sex and BMI accounted for 11.7% of the variance in MOXFQ-index and psychological variables accounted for an additional 28.2%. Pain catastrophising was the most significant independent predictor of foot/ankle pain severity (accounting for 14.4% of variance), followed by BMI (10.7%) and depressive symptoms (2.3%).

Conclusions

This study demonstrated that specific psychological comorbidities and increased BMI are common in this cohort and that these factors are associated with the symptoms for which patients are seeking orthopaedic assessment. This knowledge should prompt clinicians to routinely consider the psychosocial components of patient presentations and develop non-operative and pre-operative treatment strategies which consider these factors with the goal of improving overall patient outcomes.

Abstract WMP119: Tanshinone IIa-loaded Nanoparticles And Induced Pluripotent Stem Cell-derived Neural Stem Cell Therapies Enhance Recovery In A Translational Pig Ischemic Stroke Model

Induced pluripotent stem cell-derived neural stem cells (iNSCs) have led to cellular and functional recovery in ischemic stroke models. However, the therapeutic effects of iNSC treatment are limited by decreased cell survival in the cytotoxic stroke environment. Tanshinone IIA is a potential anti-inflammatory and antioxidative treatment that may modulate this harsh microenvironment and lead to improved iNSC survival in stroke tissue. To test this hypothesis, the combined effects of Tanshinone IIA-loaded nanoparticles (Tan IIA-NPs) and iNSCs were evaluated in a translational pig ischemic stroke model. 18 Yucatan pigs underwent middle cerebral artery occlusion and were assigned to the following treatment groups: PBS+PBS, PBS+iNSC, or Tan IIA-NP+iNSC. PBS or Tan IIA-NPs were administered intracisternally 1-hour post-stroke and either PBS or iNSCs were transcranially transplanted into the parenchyma 5 days post-stroke. Magnetic resonance imaging (MRI) was collected 24 hours post-stroke and 12 weeks post-transplantation. Immunohistochemistry was completed 12 weeks post-iNSC transplantation. MRI demonstrated that Tan IIA-NPs significantly reduced lesion volumes, midline shift, and intracerebral hemorrhage, while iNSCs improved white matter integrity. Immunohistochemistry revealed that Tan IIA-NP+iNSC treatment significantly increased NeuN+ neurons in the penumbra relative to PBS+iNSC and PBS+PBS treatment groups. Tan IIA-NP+iNSC treated pigs also showed significantly decreased Iba1+ immune cells and GFAP+ activated astrocytes in the penumbra relative to PBS+iNSC and PBS+PBS treated pigs. Tan IIA-NP+iNSC treated pigs showed significantly increased DCX+ neuroblasts at the lesion border and in the ventricular lining of the subventricular zone relative to PBS+iNSC and PBS+PBS pigs. In addition, PBS+iNSC treated pigs also showed significantly more DCX+ neuroblasts than PBS+PBS pigs. Collectively, Tan IIA-NPs in combination with iNSCs possess potential as a multifaceted neuroprotective and regenerative treatment for ischemic stroke patients. The robust tissue preservation and recovery responses in a predictive large animal model strongly support the continued evaluation of this novel combination therapy.

Treatment of hallux valgus by Scarf osteotomy - rates and reasons for recurrence and rates of avascular necrosis: A systematic review

BACKGROUND

We reviewed the rates of and reasons for hallux valgus (HV) recurrence and the rates of avascular necrosis following Scarf osteotomy.

METHODS

We searched the Cochrane Library, PubMed, and Embase databases for studies reporting operative management of HV using Scarf osteotomy. The primary endpoints were reasons for and rates of HV recurrence. The secondary endpoint was the rate of avascular necrosis.

RESULTS

We included 15 studies with 946 operations for HV. Seven studies reported no recurrence, six reported recurrence rates of 3.6-11.3%, one reported a recurrence rate of 30%, and one reported a recurrence rate of 78%. Thirteen studies (678 feet) reported other complications from Scarf osteotomy without avascular necrosis.

CONCLUSIONS

Although HV recurrence is not uncommon following Scarf osteotomy, patient-related factors, surgical competence, and longer follow-up are more likely to be associated with recurrence. Avascular necrosis is an infrequent complication in HV patients treated using Scarf osteotomy.

A Bibliometric Analysis of 4 Major Foot and Ankle Surgery Journals

Research publication is a central to the scientific process and comprehensive bibliometric analysis is a leading way to better understand trends within research. Currently, there are limited bibliometric analyses of literature pertaining to foot and ankle surgery. This study aims to quantify the volume of research and investigate what may affect publication and citation. Journals associated with the 3 major orthopedic foot and ankle societies (Foot & Ankle International[FAI], Foot and Ankle Surgery, and The Foot) and one podiatric college (Journal of Foot and Ankle Surgery®) were evaluated from January 2009 to December 2018 using Scopus (Elsevier, Amsterdam, the Netherlands). Descriptive statistics were used to summarize article characteristics and regression modeling was used to determine factors associated with a country's current and future productivity and an article's citation rate. A total of 4994 articles were published over the 10-year period, with the largest contributor of publications being the United States of America (USA), who produced 2096 (41.8%) publications. Regression analysis found no association between a country's productivity and gross domestic product or population. There was no significant relationship between a country's baseline publication rate and future publication rate. The variables significantly associated with an increased citation count were; the number of years since publication, the number of authors, publication in FAI and if the article was a review. To our knowledge this is the largest bibliometric analysis of foot and ankle publications. The majority of research is being produced by the USA, but there are numerous complex factors associated with citation and publication rates. Further research is required to fully assess these factors and characterize the state of foot and ankle surgery research.

Overview of randomised controlled trials in hallux valgus surgery (2,184 patients)

BACKGROUND

The aim of this study is to provide an overview of randomised controlled trials (RCTs) in hallux valgus correction surgery summarising the available high-quality evidence.

METHODS

Following PRISMA guidelines, we searched the Cochrane Central Register of Controlled Trials, Ovid MEDLINE (1946 to 1 February 2020) and Embase (1980 to 1 February 2020). We excluded non-randomised trials, systematic reviews and case-series. We also excluded trials of MTPJ arthrodesis. Trials that met our inclusion criteria were assessed by two authors using a binary outcome measure of whether they reported statistically significant findings. These were then classified according to intervention groups.

RESULTS

32 RCTs met the inclusion criteria and were included. The total number of patients in those trials was 2,184. Only 4 RCTs (12.5%) reported significant differences between the intervention and the control groups. The remaining trials evaluated scarf or chevron osteotomies in 18 RCTs, and 10 RCTs compared other osteotomies or technical aspects of hallux valgus surgery using functional and radiological outcome measures with none reporting significant differences.

CONCLUSION

Evidence from RCTs of hallux valgus surgery suggest that scarf and chevron osteotomies are the most popular techniques and lead to similar clinical outcomes.

Poliomyelomalacia in three dogs that underwent hemilaminectomy for intervertebral disk herniation

CASE DESCRIPTION

3 dogs were examined because of a sudden onset of signs of pain (1 dog) or paraparesis (2 dogs).

CLINICAL FINDINGS

Neurologic findings consisted of myelopathy affecting the lumbar intumescence (1 dog) and T3-L3 myelopathy (2 dogs). In all dogs, MRI revealed spinal cord compression caused by L3-4 disk herniation. All dogs underwent routine surgical decompression of the intervertebral disk herniation. During MRI and decompressive surgery, physiologic variables were monitored. Immediately after surgery, all dogs were paraplegic with pelvic limb neurologic dysfunction consistent with myelopathy affecting the L4 through caudal spinal cord segments.

TREATMENT AND OUTCOME

Within 24 hours after surgery, repeated MRI in all dogs revealed hyperintensity in the spinal cord gray matter of the lumbar intumescence on T2-weighted images. In the absence of neurologic improvement, dogs were euthanized at 3, 91, and 34 days after surgery. Postmortem microscopic examination of each dog's spinal cord at the lumbar intumescence revealed necrosis of the gray matter with relative white matter preservation suggestive of an ischemic injury.

CLINICAL RELEVANCE

Dramatic neurologic deterioration following decompressive surgery for intervertebral disk herniation in dogs may be associated with the development of poliomyelomalacia secondary to ischemia. In these 3 dogs, ischemia developed despite probable maintenance of normal spinal cord blood flow and perfusion during anesthesia. To exclude other causes, such as compression or hemorrhage, MRI was repeated and revealed hyperintensity of the spinal cord gray matter on T2-weighted images, which microscopically corresponded with ischemic neurons and neuronal loss.

Peri-ictal magnetic resonance imaging characteristics in dogs with suspected idiopathic epilepsy

Background

The pathophysiology of changes in magnetic resonance imaging (MRI) detected after a seizure is not fully understood.

Objective

To characterize and describe seizure‐induced changes detected by MRI.

Animals

Eighty‐one client‐owned dogs diagnosed with idiopathic epilepsy.

Methods

Data collected retrospectively from medical records and included anatomical areas affected, T1‐, T2‐weighted and T2‐FLAIR (fluid‐attenuated inversion recovery) appearance, whether changes were unilateral or bilateral, symmetry, contrast enhancement, mass effect, and, gray and white matter distribution. Diffusion‐ and perfusion weighted maps were evaluated, if available.

Results

Seizure‐induced changes were T2‐hyperintense with no suppression of signal on FLAIR. Lesions were T1‐isointense (55/81) or hypointense (26/81), local mass effect (23/81) and contrast enhancement (12/81). The majority of changes were bilateral (71/81) and symmetrical (69/71). The most common areas affected were the hippocampus (39/81) cingulate gyrus (33/81), hippocampus and piriform lobes (32/81). Distribution analysis suggested concurrence between cingulate gyrus and pulvinar thalamic nuclei, the cingulate gyrus and parahippocampal gyrus, hippocampus and piriform lobe, and, hippocampus and parahippocampal gyrus. Diffusion (DWI) characteristics were a mixed‐pattern of restricted, facilitated, and normal diffusion. Perfusion (PWI) showed either hypoperfusion (6/9) or hyperperfusion (3/9).

Conclusions and Clinical Importance

More areas, than previously reported, have been identified that could incur seizure‐induced changes. Similar to human literature, DWI and PWI changes have been identified that could reflect the underlying metabolic and vascular changes.

Safety and interim survival data after intracranial administration of M032, a genetically engineered oncolytic HSV-1 expressing IL-12, in pet dogs with sporadic gliomas

OBJECTIVE

The diagnosis of glioma remains disheartening in the clinical realm. While a multitude of studies and trials have shown promise, improvements in overall survival have been disappointing. Modeling these tumors in the laboratory setting has become increasingly challenging, given their complex in situ behavior and interactions for therapeutic evasion. Dogs, particularly brachycephalic breeds, are known to spontaneously develop gliomas that resemble human gliomas both clinically and pathophysiologically, making canines with sporadic tumors promising candidates for study. Typically, survival among these dogs is approximately 2 months with palliation alone.

METHODS

The authors have completed the first stage of a unique phase I dose-escalating canine clinical trial in which the safety and tolerability of M032, a nonneurovirulent oncolytic herpes simplex virus-1 vector genetically engineered to express interleukin-12, are being studied in pet dogs with gliomas undergoing maximum safe tumor resection and inoculation of the cavity with the viral infusate.

RESULTS

Twenty-five canine patients were enrolled between January 2018 and August 2020. One patient was electively withdrawn from the trial by its owner, and 3 did not receive the virus. For the 21 dogs that remained, 13 had high-grade gliomas, 5 had low-grade gliomas, and 3 were undetermined. According to histopathological analysis, 62% of the tumors were oligodendrogliomas. At the time of this report, the median overall survival from the date of treatment was 151 days (± 78 days). No significant adverse events attributable to M032 or dose-limiting toxicities have been observed to date.

CONCLUSIONS

In this largest study of oncolytic viral therapy for canine brain tumors to date, treatment with M032 did not cause harm and the combination of surgery and oncolytic viral therapy may have contributed to prolonged survival in pet dogs with spontaneous gliomas. Forthcoming in-depth radiographic, immunohistochemical, and genetic analyses will afford a more advanced understanding of how this treatment impacts these tumors and the immune system. Our goal is to utilize these findings bitranslationally to inform human studies and refine therapies that will improve outcomes in both humans and pet dogs with gliomas.

Magnetic Resonance Imaging and Gait Analysis Indicate Similar Outcomes Between Yucatan and Landrace Porcine Ischemic Stroke Models

The Stroke Therapy Academic Industry Roundtable (STAIR) has recommended that novel therapeutics be tested in a large animal model with similar anatomy and physiology to humans. The pig is an attractive model due to similarities in brain size, organization, and composition relative to humans. However, multiple pig breeds have been used to study ischemic stroke with potentially differing cerebral anatomy, architecture and, consequently, ischemic stroke pathologies. The objective of this study was to characterize brain anatomy and assess spatiotemporal gait parameters in Yucatan (YC) and Landrace (LR) pigs pre- and post-stroke using magnetic resonance imaging (MRI) and gait analysis, respectively. Ischemic stroke was induced via permanent middle cerebral artery occlusion (MCAO). MRI was performed pre-stroke and 1-day post-stroke. Structural and diffusion-tensor sequences were performed at both timepoints and analyzed for cerebral characteristics, lesion diffusivity, and white matter changes. Spatiotemporal and relative pressure gait measurements were collected pre- and 2-days post-stroke to characterize and compare acute functional deficits. The results from this study demonstrated that YC and LR pigs exhibit differences in gross brain anatomy and gait patterns pre-stroke with MRI and gait analysis showing statistical differences in the majority of parameters. However, stroke pathologies in YC and LR pigs were highly comparable post-stroke for most evaluated MRI parameters, including lesion volume and diffusivity, hemisphere swelling, ventricle compression, caudal transtentorial and foramen magnum herniation, showing no statistical difference between the breeds. In addition, post-stroke changes in velocity, cycle time, swing percent, cadence, and mean hoof pressure showed no statistical difference between the breeds. These results indicate significant differences between pig breeds in brain size, anatomy, and motor function pre-stroke, yet both demonstrate comparable brain pathophysiology and motor outcomes post-stroke. The conclusions of this study suggest pigs of these different breeds generally show a similar ischemic stroke response and findings can be compared across porcine stroke studies that use different breeds.

Evaluation of immunologic parameters in canine glioma patients treated with an oncolytic herpes virus

AIM

To molecularly characterize the tumor microenvironment and evaluate immunologic parameters in canine glioma patients before and after treatment with oncolytic human IL-12-expressing herpes simplex virus (M032) and in treatment naïve canine gliomas.

METHODS

We assessed pet dogs with sporadically occurring gliomas enrolled in Stage 1 of a veterinary clinical trial that was designed to establish the safety of intratumoral oncoviral therapy with M032, a genetically modified oncolytic herpes simplex virus. Specimens from dogs in the trial and dogs not enrolled in the trial were evaluated with immunohistochemistry, NanoString, Luminex cytokine profiling, and multi-parameter flow cytometry.

RESULTS

Treatment-naive canine glioma microenvironment had enrichment of Iba1 positive macrophages and minimal numbers of T and B cells, consistent with previous studies identifying these tumors as immunologically "cold". NanoString mRNA profiling revealed enrichment for tumor intrinsic pathways consistent with suppression of tumor-specific immunity and support of tumor progression. Oncolytic viral treatment induced an intratumoral mRNA transcription signature of tumor-specific immune responses in 83% (5/6) of canine glioma patients. Changes included mRNA signatures corresponding with interferon signaling, lymphoid and myeloid cell activation, recruitment, and T and B cell immunity. Multiplexed protein analysis identified a subset of oligodendroglioma subjects with increased concentrations of IL-2, IL-7, IL-6, IL-10, IL-15, TNFα, GM-CSF between 14 and 28 days after treatment, with evidence of CD4⁺ T cell activation and modulation of IL-4 and IFNγ production in CD4⁺ and CD8⁺ T cells isolated from peripheral blood.

CONCLUSION

These findings indicate that M032 modulates the tumor-immune microenvironment in the canine glioma model.

Dynamic Changes in the Gut Microbiome at the Acute Stage of Ischemic Stroke in a Pig Model

Stroke is a major cause of death and long-term disability affecting seven million adults in the United States each year. Recently, it has been demonstrated that neurological diseases, associated pathology, and susceptibility changes correlated with changes in the gut microbiota. However, changes in the microbial community in stroke has not been well characterized. The acute stage of stroke is a critical period for assessing injury severity, therapeutic intervention, and clinical prognosis. We investigated the changes in the gut microbiota composition and diversity using a middle cerebral artery (MCA) occlusion ischemic stroke pig model. Ischemic stroke was induced by cauterization of the MCA in pigs. Blood samples were collected prestroke and 4 h, 12 h, 1 day, and 5 days poststroke to evaluate circulating proinflammatory cytokines. Fecal samples were collected prestroke and 1, 3, and 5 days poststroke to assess gut microbiome changes. Results showed elevated systemic inflammation with increased plasma levels of tumor necrosis factor alpha at 4 h and interleukin-6 at 12 h poststroke, relative to prestroke. Microbial diversity and evenness were reduced at 1 day poststroke compared to prestroke. Microbial diversity at 3 days poststroke was negatively correlated with lesion volume. Moreover, beta-diversity analysis revealed trending overall differences over time, with the most significant changes in microbial patterns observed between prestroke and 3 days poststroke. Abundance of the Proteobacteria was significantly increased, while Firmicutes decreased at 3 days poststroke, compared to prestroke populations. Abundance of the lactic acid bacteria Lactobacillus was reduced at 3 days poststroke. By day 5, the microbial pattern returned to similar values as prestroke, suggesting the plasticity of gut microbiome in an acute period of stroke in a pig model. These findings provide a basis for characterizing gut microbial changes during the acute stage of stroke, which can be used to assess stroke pathology and the potential development of therapeutic targets.

Cost-effectiveness of interventions for musculoskeletal foot and ankle conditions: a systematic review

OBJECTIVE

Musculoskeletal conditions of the foot and ankle are common, yet the cost-effectiveness of the variety of treatments available is not well defined. The aim of this systematic review was therefore to identify, appraise and synthesise the literature pertaining to the cost-effectiveness of interventions for musculoskeletal foot and ankle conditions.

METHODS

Electronic databases were searched for studies presenting economic evaluations of non-surgical and surgical treatments for acute or chronic musculoskeletal conditions of the foot and ankle. Data on cost, incremental cost-effectiveness and quality-adjusted life years for each intervention and comparison were extracted. Risk of bias was assessed using the Drummond checklist for economic studies (range 0-35).

RESULTS

Thirty-six studies were identified reporting non-surgical interventions (n=10), non-surgical versus surgical interventions (n=14) and surgical interventions (n=12). The most common conditions were osteoarthritis, ankle fracture and Achilles tendon rupture. The strongest economic evaluations were for interventions managing end-stage ankle osteoarthritis, ankle sprain, ankle fracture, calcaneal fracture, and Achilles tendon rupture. Total ankle replacement and ankle arthrodesis for end-stage ankle osteoarthritis, in particular, have been demonstrated through high-quality studies to be cost-effective compared to the non-surgical alternative.

CONCLUSION

Selected interventions for musculoskeletal foot and ankle conditions dominate comparators, whereas others require thoughtful consideration as they provide better clinical improvements, but at an increased cost. Researchers should consider measuring and reporting costs alongside clinical outcome to provide context when determining the appropriateness of interventions for other foot and ankle complaints to best inform future clinical practice guidelines.

The One Health Consortium: Design of a Phase I Clinical Trial to Evaluate M032, a Genetically Engineered HSV-1 Expressing IL-12, in Combination With a Checkpoint Inhibitor in Canine Patients With Sporadic High Grade Gliomas

As the most common and deadly of primary brain tumors, malignant gliomas have earned their place within one of the most multifaceted and heavily-funded realms of medical research. Numerous avenues of pre-clinical investigation continue to provide valuable insight, but modeling the complex evolution and behavior of these tumors within a host under simulated circumstances may pose challenges to extrapolation of data. Remarkably, certain breeds of pet dogs spontaneously and sporadically develop high grade gliomas that follow similar incidence, treatment, and outcome patterns as their human glioma counterparts. The most malignant of these tumors have been refractory to limited treatment options despite aggressive treatment; outcomes are dismal with median survivals of just over 1 year in humans and 2 months in dogs. Novel treatments are greatly needed and combination therapies appear to hold promise. This clinical protocol, a dose-escalating phase I study in dogs with sporadic malignant glioma, represents a first in comparative oncology and combination immunotherapy. The trial will evaluate M032, an Interleukin-12 expressing Herpes Simplex virus, alone and combined with a checkpoint inhibitor, Indoximod. Extensive pre-clinical work has demonstrated safety of intracranial M032 administration in mice and non-human primates. M032 is currently being tested in humans with high-grade malignant gliomas. Thus, in a novel fashion, both canine and human trials will proceed concurrently allowing a direct “head-to-head” comparison of safety and efficacy. We expect this viral oncolytic therapy to be as safe as it is in human patients and M032 to (a) infect and kill glioma cells, producing a virus and tumor cell antigen-rich debris field; (b) provide an adjuvant effect due to liberation of viral DNA, which is rich in unmethylated CpG sequences that “toggle” TLR-9 receptors; and (c) express IL-12 locally, stimulating induction of TH1 lymphocytes. The resultant immune-mediated anti-viral responses should, through cross-epitope spreading, translate into a strong response to tumor antigens. The ability to compare human and dog responses in real time affords the most stringent test of suitability of the dog as an informative model of human brain tumors. Subsequent studies will allow canine trials to properly inform the design of human trials.

Abstract 4568: The One Health Consortium and combination immunotherapy: evaluating M032, a genetically engineered HSV-1 expressing Il-12, in combination with a checkpoint inhibitor in canine glioma patients

Introduction: Malignant gliomas are the most common primary brain tumors in humans, accounting for approximately 30% of all primary CNS tumors in adults (Levin et al., 2001). Interestingly, pet dogs spontaneously and sporadically develop malignant glial brain tumors that resemble high-grade gliomas in humans; with similar incidence, treatments, and outcome patterns. (Priester and McKay, 1980; Snyder et al., 2006; Ostrom et al., 2013; Ostrom et al., 2014; Hicks et al., 2017) The most malignant of these tumors have been refractory to limited treatment options. Despite aggressive treatment, outcomes are dismal with median survivals just over one year in humans and two months in dogs. Novel treatments are greatly needed and combination therapies appear to hold promise.

Background: This pre-clinical protocol, a dose-escalating phase I study in dogs with sporadic malignant glioma, represents a first in comparative oncology and combination immunotherapy. The trial is evaluating M032, an Interleukin-12 expressing Herpes Simplex virus, alone and combined with a checkpoint inhibitor, Indoximod. Note, prior studies have demonstrated human IL-12 to generate effective anti-tumoral response in canine patients (Pavlin et al., 2012). M032 is currently being tested in humans with high-grade malignant gliomas. Thus, in a novel fashion, both canine and human trials are proceeding concurrently, allowing a direct “head-to-head” comparison of safety and efficacy.

Methods: Stage 1 of the trial, which is presently ongoing, involves catheter-based administration of MO32 alone into the tumor resection cavity at escalating doses in subsequent cohorts of dogs to establish maximum tolerable dose (MTD), detect dose limiting toxicities (DLT), quantify immune response via serum assays, and determine survival benefit. Stage 2 will involve administration of a fixed dose of MO32 derived from Stage 1 data followed by 4 weeks of daily Indoximod administration at a pre-determined dose, with interval comparative immune assays, neurological monitoring, and imaging surveillance. Indoximod is expected to blunt suppressive cellular (Tregs, MDSCs) immune response components, allowing a longer time for effective anti-viral responses and via cross-epitope spreading, an anti-tumor response that will be more durable than that observed with administration of virus alone. In all cases, tumor is collected, processed, and archived for future studies, including whole genome and RNA sequencing.

Results: Preliminary data from Stage 1 have demonstrated a median survival of 188 days among all canines following infusion of M032 HSV (95% confidence interval of 83.2 to 292.8 days). Nine canines have died and eight are still alive following treatment. Current dose is 1 x 109 plaque-forming units. No dose limiting toxicities have been observed with infusion of M032 alone.

Conclusions: The ability to compare human and dog responses in real time affords the most stringent test of suitability of the dog as a valid and informative model of human brain tumors. The results of this and subsequent studies will allow canine trials to properly inform the design of human trials and further support bi-translational studies and the One Medicine approach to clinical research and application.

Citation Format: M. R. Chambers, R. T. Bentley, David Crossman, Jeremy B. Foote, J. W. Koehler, James M. Markert, Simon R. Platt, Nidal B. Omar, D. M. Self, Andy Shores, Don Sorjonen, Alicia M. Waters, Amy B. Yanke, G Y. Gillespie. The One Health Consortium and combination immunotherapy: evaluating M032, a genetically engineered HSV-1 expressing Il-12, in combination with a checkpoint inhibitor in canine glioma patients [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4568.

Characterization of tissue and functional deficits in a clinically translational pig model of acute ischemic stroke

The acute stroke phase is a critical time frame used to evaluate stroke severity, therapeutic options, and prognosis while also serving as a major tool for the development of diagnostics. To further understand stroke pathophysiology and to enhance the development of treatments, our group developed a translational pig ischemic stroke model. In this study, the evolution of acute ischemic tissue damage, immune responses, and functional deficits were further characterized. Stroke was induced by middle cerebral artery occlusion in Landrace pigs. At 24 h post-stroke, magnetic resonance imaging revealed a decrease in ipsilateral diffusivity, an increase in hemispheric swelling resulting in notable midline shift, and intracerebral hemorrhage. Stroke negatively impacted white matter integrity with decreased fractional anisotropy values in the internal capsule. Like patients, pigs showed a reduction in circulating lymphocytes and a surge in neutrophils and band cells. Functional responses corresponded with structural changes through reductions in open field exploration and impairments in spatiotemporal gait parameters. Characterization of acute ischemic stroke in pigs provided important insights into tissue and functional-level assessments that could be used to identify potential biomarkers and improve preclinical testing of novel therapeutics.

Overview of Randomized Controlled Trials in Total Knee Arthroplasty (47,675 Patients): What Have We Learnt?

BACKGROUND

The aim of this study is to provide an overview of randomized controlled trials (RCTs) in primary total knee arthroplasty summarizing the available high-quality evidence.

METHODS

Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, we searched the Cochrane Central Register of Controlled Trials (CENTRAL, 2019, Issue 3), Ovid MEDLINE, and Embase. We excluded nonrandomized trials, trials on unicompartmental knee arthroplasty or revision surgery, systematic reviews, and meta-analyses. Trials that met our inclusion criteria were assessed using a binary outcome measure of whether they reported statistically significant findings. These were then classified according to the intervention groups (surgical approach, tourniquet use, design, etc.).

RESULTS

Four hundred and three RCTs met the inclusion criteria and were included. The total number of patients in those 403 RCTs was 47,675. Only 33 RCTs (8.2%) reported significant differences between the intervention and the control groups. The trials were grouped into surgical approach 34, tourniquet 31, minimally invasive surgery 13, patient specific instrumentation 30, knee design 37, fixation 27, mobile bearing 47, navigation 50, polyethylene 19, technique 27, patella resurfacing 26, drain 19, closure 16, and others 27 RCTs.

CONCLUSION

For the vast majority of patients, a standard conventional total knee arthroplasty with a surgical approach familiar to the surgeon using standard well-established components, with or without tourniquet, without surgical drain leads to satisfactory long-term clinical outcomes.

Imaging Ischemic and Hemorrhagic Disease of the Brain in Dogs

Strokes, both ischemic and hemorrhagic, are the most common underlying cause of acute, non-progressive encephalopathy in dogs. In effect, substantial information detailing the underlying causes and predisposing factors, affected vessels, imaging features, and outcomes based on location and extent of injury is available. The features of canine strokes on both computed tomography (CT) and magnetic resonance imaging (MRI) have been described in numerous studies. This summary article serves as a compilation of these various descriptions. Drawing from the established and emerging stroke evaluation sequences used in the investigation of strokes in humans, this summary describes all theoretically available sequences. Particular detail is given to logistics of image acquisition, description of imaging findings, and each sequence's advantages and disadvantages. As the imaging features of both forms of strokes are highly representative of the underlying pathophysiologic stages in the hours to months following stroke onset, the descriptions of strokes at various stages are also discussed. It is unlikely that canine strokes can be diagnosed within the same rapid time frame as human strokes, and therefore the opportunity for thrombolytic intervention in ischemic strokes is unattainable. However, a thorough understanding of the appearance of strokes at various stages can aid the clinician when presented with a patient that has developed a stroke in the days or weeks prior to evaluation. Additionally, investigation into new imaging techniques may increase the sensitivity and specificity of stroke diagnosis, as well as provide new ways to monitor strokes over time.

Traumatic Brain Injury Results in Dynamic Brain Structure Changes Leading to Acute and Chronic Motor Function Deficits in a Pediatric Piglet Model

Traumatic brain injury (TBI) is a leading cause of death and disability in children. Pediatric TBI patients often suffer from crippling cognitive, emotional, and motor function deficits that have negative lifelong effects. The objective of this study was to longitudinally assess TBI pathophysiology using multi-parametric magnetic resonance imaging (MRI), gait analysis, and histological approaches in a pediatric piglet model. TBI was produced by controlled cortical impact in Landrace piglets. MRI data, including from proton magnetic resonance spectroscopy (MRS), were collected 24 hours and 12 weeks post-TBI, and gait analysis was performed at multiple time-points over 12 weeks post-TBI. A subset of animals was sacrificed 24 hours, 1 week, 4 weeks, and 12 weeks post-TBI for histological analysis. MRI results demonstrated that TBI led to a significant brain lesion and midline shift as well as microscopic tissue damage with altered brain diffusivity, decreased white matter integrity, and reduced cerebral blood flow. MRS showed a range of neurochemical changes after TBI. Histological analysis revealed neuronal loss, astrogliosis/astrocytosis, and microglia activation. Further, gait analysis showed transient impairments in cadence, cycle time, % stance, step length, and stride length, as well as long-term impairments in weight distribution after TBI. Taken together, this study illustrates the distinct time course of TBI pathoanatomic and functional responses up to 12 weeks post-TBI in a piglet TBI model. The study of TBI injury and recovery mechanisms, as well as the testing of therapeutics in this translational model, are likely to be more predictive of human responses and clinical outcomes compared to traditional small animal models.

Human iNPC therapy leads to improvement in functional neurologic outcomes in a pig ischemic stroke model

INTRODUCTION

Stroke is the leading cause of disability in the United States but current therapies are limited with no regenerative potential. Previous translational failures have highlighted the need for large animal models of ischemic stroke and for improved assessments of functional outcomes. The aims of this study were first, to create a post-stroke functional outcome assessment scale in a porcine model of middle cerebral artery occlusion (MCAO) and second, to use this scale to determine the effect of human-induced-pluripotent-cell-derived neural progenitor cells (iNPCs) on functional outcome in this large animal stroke model.

MATERIALS AND METHODS

Eight 6-month-old Landrace mix pigs underwent permanent MCAO. Five days following MCAO, pigs received intraparenchymal injections of either iNPCs or PBS. A post-stroke assessment scale was developed to measure functional outcome. Evaluations were performed at least 1-3 days prior to MCAO and repeated 1 day, 3 days, and 5 days post-stroke as well as 1 day, 3 days, 1 week, 2 weeks, 4 weeks, 6 weeks, 9 weeks, and 12 weeks post-injection. Comparisons of scores between animals receiving iNPCs or PBS only were compared using a two-way ANOVA and a Tukey's post-hoc t test.

RESULTS

The developed scale was able to consistently determine differences between healthy and stroked pigs at all time points. iNPC-treated pigs showed a significantly faster recovery in their overall scores relative to PBS-only treated pigs with the parameters of appetite and body posture exhibiting the most improvement in the iNPC-treated group.

CONCLUSIONS

We developed a robust and repeatable functional assessment tool that can reliably detect stroke and recovery, while also showing for the first time that iNPC therapy leads to functional recovery in a translational pig ischemic stroke model. These promising results suggest that iNPCs may 1 day serve as a first in class cell therapeutic for ischemic stroke.

Pharmacokinetic evaluation of novel midazolam gel formulations following buccal administration to healthy dogs

OBJECTIVE To determine the physiochemical properties and pharmacokinetics of 3 midazolam gel formulations following buccal administration to dogs. ANIMALS 5 healthy adult hounds. PROCEDURES In phase 1 of a 2-phase study, 2 gel formulations were developed that contained 1% midazolam in a poloxamer 407 (P1) or hydroxypropyl methylcellulose (H1) base and underwent rheological and in vitro release analyses. Each formulation was buccally administered to 5 dogs such that 0.3 mg of midazolam/kg was delivered. Each dog also received midazolam hydrochloride (0.3 mg/kg, IV). There was a 3-day interval between treatments. Blood samples were collected immediately before and at predetermined times for 8 hours after drug administration for determination of plasma midazolam concentration and pharmacokinetic analysis. During phase 2, a gel containing 2% midazolam in a hydroxypropyl methylcellulose base (H2) was developed on the basis of phase 1 results. That gel was buccally administered such that midazolam doses of 0.3 and 0.6 mg/kg were delivered. Each dog also received midazolam (0.3 mg/kg, IV). All posttreatment procedures were the same as those for phase 1. RESULTS The H1 and H2 formulations had lower viscosity, greater bioavailability, and peak plasma midazolam concentrations that were approximately 2-fold as high, compared with those for the P1 formulation. The mean peak plasma midazolam concentration for the H2 formulation was 187.0 and 106.3 ng/mL when the midazolam dose administered was 0.6 and 0.3 mg/kg, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that buccal administration of gel formulations might be a viable alternative for midazolam administration to dogs.

Canine NAPEPLD-associated models of human myelin disorders

Canine leukoencephalomyelopathy (LEMP) is a juvenile-onset neurodegenerative disorder of the CNS white matter currently described in Rottweiler and Leonberger dogs. Genome-wide association study (GWAS) allowed us to map LEMP in a Leonberger cohort to dog chromosome 18. Subsequent whole genome re-sequencing of a Leonberger case enabled the identification of a single private homozygous non-synonymous missense variant located in the highly conserved metallo-beta-lactamase domain of the N-acyl phosphatidylethanolamine phospholipase D (NAPEPLD) gene, encoding an enzyme of the endocannabinoid system. We then sequenced this gene in LEMP-affected Rottweilers and identified a different frameshift variant, which is predicted to replace the C-terminal metallo-beta-lactamase domain of the wild type protein. Haplotype analysis of SNP array genotypes revealed that the frameshift variant was present in diverse haplotypes in Rottweilers, and also in Great Danes, indicating an old origin of this second NAPEPLD variant. The identification of different NAPEPLD variants in dog breeds affected by leukoencephalopathies with heterogeneous pathological features, implicates the NAPEPLD enzyme as important in myelin homeostasis, and suggests a novel candidate gene for myelination disorders in people.

Post-operative Salmonella surgical site infection in a dog

Following decompressive surgery for degenerative lumbosacral stenosis, a 6-year-old German shepherd dog developed a subcutaneous infection at the surgical site and discospondylitis at the lumbosacral intervertebral disc. Salmonella enterica subsp. enterica, serotype Dublin was recovered from the surgical site. Salmonella of a different serovar was isolated from a sample of the raw meat-based diet that the owner fed the dog.

Abstract WP115: Transplanted Induced Neural Stem Cells Differentiate and Integrate Into the Brain Parenchyma of Ischemic Stroke Pigs Leading to Improved Tissue Recovery

Studies in rodents have provided evidence that induced pluripotent stem cell derived neural stem cells (iNSCs) have a multifunctional role in stroke recovery. iNSCs mitigate tissue loss due to secondary injury, promote tissue recovery through angiogenesis, and differentiate into mature neural cell types resulting in recovery and replacement of lost and damaged brain tissue. However, many stroke therapies developed in the rodent have failed in clinical trials, suggesting that iNSC therapy should be tested in a more translatable large animal model such as the pig. The objective of this study was to assess the ability of iNSCs to differentiate into mature neural cell types and characterize the effects of iNSCs on brain tissue recovery utilizing non-invasive magnetic resonance imaging (MRI) and spectroscopy approaches in a pig model. Eight male landrace pigs underwent middle cerebral artery occlusion stroke surgery. After 5 days, 4 pigs received iNSC intraparenchymal injections and 4 pigs received vehicle only injections. Pigs underwent MRI assessment at 24 hrs post-stroke and 1, 4, and 12 wks post-injection, and brain tissues were collected 12 wks post-injection. At 12 wks post-injection, iNSC treated pigs showed significant improvement in white matter integrity with recovery of fractional anisotropy being 4-fold higher in treated pigs relative to non-treated pigs. Perfusion weighted imaging demonstrated significant improvement in cerebral blood volume (13%), time to peak (36%), and mean transit time (41%) in treated pigs at 12 wks post-injection vs. non-treated pigs. In addition, treated pigs showed significant improvement in neurometabolites NAA, Cr, and Cho at 12 wks post-injection relative to non-treated pigs. Gene expression analysis established significant increases in neurotrophic and angiogenic factors including BDNF and ANG1, respectively, in brain tissue of treated pigs vs. non-treated pigs suggesting potential modes of action. iNSCs were located in the brain parenchyma 12 wks post-injection, and the majority were positive for the mature neuronal marker NeuN. These results demonstrated that iNSCs are capable of neuronal differentiation and long term integration while promoting tissue recovery in a preclinical pig ischemic stroke model.

Effect of Cranberry Extract on the Frequency of Bacteriuria in Dogs with Acute Thoracolumbar Disk Herniation: A Randomized Controlled Clinical Trial

Background

Dogs with spinal cord injury are at increased risk of developing bacteriuria due to increased residual urine volume. Cranberry extract inhibits binding of E. coli to uroepithelial cells, potentially reducing risk of bacteriuria.

Hypothesis

Cranberry extract reduces risk of bacteriuria in dogs after acute TL‐IVDH.

Animals

Client‐owned dogs with acute onset TL‐IVDH causing nonambulatory status.

Methods

Randomized, placebo‐controlled, blinded, prospective clinical trial. Dogs with acute TL‐IVDH were recruited 48 hours postoperatively and randomized to receive cranberry extract or placebo in a masked fashion. Urine cultures and neurological examinations were performed 2, 4, and 6 weeks postoperatively. The number of dogs with bacteriuria (all bacterial species) and bacteriuria (E. coli) were primary and secondary outcome measures and were evaluated using chi‐squared test. Urine antiadhesion activity (AAA) was measured in a subset (N = 47) and examined in a secondary analysis evaluating additional risk factors for bacteriuria.

Results

Bacteriuria was detected 17 times in 94 dogs (6 placebo, 11 cranberry, P = .12). There were 7 E. coli. positive cultures (1 placebo, 6 cranberry, P = .09). Dogs in both groups had positive urine AAA (14/21: placebo, 16/26: cranberry), and dogs with urine AAA had significantly fewer E. coli positive cultures (n = 1) than dogs without it (n = 4) (P = .047).

Conclusions and Clinical Importance

This clinical trial did not show a benefit of oral cranberry extract but had low power. Cranberry extract supplementation did not impact urine AAA, but a possible association between urine AAA and lower risk of E. coli bacteriuria was identified. Other doses could be investigated.

Cranioplasty Using Titanium Mesh After Skull Tumor Resection in Five Dogs

OBJECTIVE

To describe the clinical details, surgery, postoperative imaging, and short to mid-term outcome after cranioplasty with titanium mesh in dogs with large skull tumors.

STUDY DESIGN

Case series.

ANIMALS

Client-owned dogs with skull tumors (n=5).

METHODS

All tumors were removed via craniectomy and a sheet of titanium mesh was contoured to reconstruct the calvarial defect and sutured to surrounding musculature.

RESULTS

Four dogs had multilobular tumors of bone and 1 dog had a soft tissue sarcoma invading the cranial vault. Neurologic examination was unchanged or improved postoperative, a good cosmetic appearance was achieved, and no complications were noted at 2 weeks postoperative. Late postoperative computed tomography (CT) in 2 dogs and magnetic resonance (MR) imaging in 1 dog confirmed the presence of the titanium mesh without migration. There was no interference of the mesh with image interpretation and definitive radiation therapy was pursued in 1 dog without complication. Late follow-up reported 2 dogs euthanatized; at 44 weeks postoperative due to tumor re-growth; at 12 weeks postoperative for hemoabdomen, respectively. One dog drowned at 40 weeks postoperative, 1 dog was lost to follow-up, and 1 dog is alive at 83 weeks postoperative free of clinical signs.

CONCLUSIONS

Titanium mesh is suitable for cranioplasty based on its strength, biocompatibility, and excellent handling characteristics. It does not interfere with acquisition or interpretation of CT or MR images, thereby allowing postoperative imaging for ongoing assessment.

Hydrocephalus secondary to obstruction of the lateral apertures in two dogs

BACKGROUND

Traditionally, hydrocephalus is divided into communicating or non-communicating (obstructive) based on the identification of a blockage of cerebrospinal fluid (CSF) flow through the ventricular system. Hydrocephalus ex vacuo refers to ventricular enlargement as a consequence of neuroparenchymal loss. Hydrocephalus related to obstruction of the lateral apertures of the fourth ventricles has rarely been described.

CASE REPORT

The clinicopathologic findings in two dogs with hydrocephalus secondary to obstruction of the lateral apertures of the fourth ventricle are reported. Signs were associated with a caudal cervical spinal cord lesion in one dog and a caudal brain stem lesion in the other dog. Magnetic resonance imaging (MRI) disclosed dilation of the ventricular system, including the lateral recesses of the fourth ventricle. In one dog, postmortem ventriculography confirmed obstruction of the lateral apertures. Microscopic changes were identified in the choroid plexus in both dogs, yet a definitive cause of the obstructions was not identified. The MRI findings in both dogs are similar to membranous occlusion of the lateral and median apertures in human patients.

CONCLUSION

MRI detection of dilation of the entire ventricular system in the absence of an identifiable cause should prompt consideration of an obstruction of the lateral apertures. In future cases, therapeutic interventions aimed at re-establishing CSF flow or ventriculoperitoneal catheterisation should be considered.

Tissue Biopsy in Infected Foot and Ankle Surgery

Category:

Basic Sciences/Biologics

Introduction/Purpose:

When performing surgical debridement to treat chronically infected orthopaedic cases our unit routinely samples 5 intraoperative specimens for microbiology. Best practice and achieving accurate sampling would suggest that a new scalpel and forceps for each sampling site would yield the most valid results.The alternate option would be to use the same instruments. The aim of this prospective study was to compare the two techniques in treating infected foot and ankle cases.

Methods:

Ten consecutive patients undergoing debridement for foot and ankle infection were prospectively included. Both techniques were performed on same patient to minimise any bias related to the type of host and severity of infection. This was achieved by collecting 5 tissue samples from 5 different sites initially using fresh instruments for each . We then used the first scalpel and forceps to sample the 2nd, 3rd, 4th, and 5th sites again. Samples were labelled from 1 to 9 where the 6th to 9th samples were from the same sites as the 2nd to 5th samples but taken by different technique. This allowed differentiating a genuine growth at a particular site from a contaminant carried on from another site.

Results:

In 7 patients the scalpel transferred microorganisms from one site to another as some of the 5 sites showed no organisms when biopsied by fresh instruments but showed growth when sampled by the re-used first scalpel. In the remaining 3 patients, the growth form the sites sampled by re-used first scalpel was consistent with the growth from those sites when ampled by fresh instruments .

Conclusion:

Our preliminary results showed that fresh scalpel and forceps are required for each sampling site to avoid transferring contamination from one site to another. This helps guide the extent of future debridement and also the type of antibiotics to be used.

Atypical Chronic Ankle Instability in a Pediatric Population Secondary to Distal Fibula Avulsion Fracture Nonunion

Chronic ankle instability is a disabling condition, often occurring as a result of traumatic ankle injury. A paucity of published data is available documenting chronic ankle instability in the pediatric population. Much of the data has been confined to the adult population. We present 2 cases of chronic ankle instability, 1 in a 12-year-old and 1 in a 9-year-old patient. Unlike the typical adult etiology, the cause of instability was a dysfunctional lateral ligamentous complex as a consequence of bony avulsion of the tip of the fibula. Both patients had sustained a twisting injury to the ankle. The fractures failed to unite. The nonunion resulted in dysfunction of the anterior talofibular ligament with consequent chronic ankle instability. At the initial clinical assessment, magnetic resonance imaging was requested for both patients. In patient 1 (12 years old), the fracture was fixed with 2 headless screws and was immobilized in a plaster cast for 6 weeks. In patient 2 (9 years old), because of the small size of the avulsed fragment, fixation was not possible. A modified Gould-Broström procedure was undertaken, facilitating repair of the avulsed fragment using anchor sutures.

2015 ACVIM Small Animal Consensus Statement on Seizure Management in Dogs

This report represents a scientific and working clinical consensus statement on seizure management in dogs based on current literature and clinical expertise. The goal was to establish guidelines for a predetermined, concise, and logical sequential approach to chronic seizure management starting with seizure identification and diagnosis (not included in this report), reviewing decision‐making, treatment strategies, focusing on issues related to chronic antiepileptic drug treatment response and monitoring, and guidelines to enhance patient response and quality of life. Ultimately, we hope to provide a foundation for ongoing and future clinical epilepsy research in veterinary medicine.

Treatment of canine meningoencephalomyelitis of unknown aetiology with mycophenolate mofetil and corticosteroids: 25 cases (2007-2012)

The use of mycophenolate mofetil (MMF) for a variety of immune‐mediated diseases in veterinary medicine has been described. However, there is only a small number of cases documenting its use in dogs with meningoencephalomyelitis of unknown aetiology (MUE). We hypothesized that the use of MMF and corticosteroids in dogs with MUE results in comparable survival data to other published treatment protocols and is associated with limited adverse effects. A retrospective study of medical case records of dogs clinically diagnosed with MUE recorded signalment, neuroanatomic localization, magnetic resonance imaging findings, cerebrospinal fluid analysis results, medications administered, follow‐up neurologic examinations, survival and adverse events. Variables were compared between dogs which were treated with MMF within 30 days of diagnosis (immediate group) vs. dogs in which MMF therapy was started >30 days after diagnosis (delayed group). Twenty‐five cases of MUE were identified. The overall median survival time from diagnosis was 731 days (range 43–1672 days). After 1 month of MMF treatment, 92% of dogs showed improvement on a neurological examination. There was no significant effect of any recorded parameter on survival, including delayed vs. immediate initiation of MMF treatment. Dogs with delayed treatment had significantly lower clinical remission rates than dogs with immediate treatment at 6 months after starting MMF. Adverse events were identified in two cases (8%) and were characterized by mild gastrointestinal signs (vomiting and decreased appetite). Administration of MMF appears safe in dogs with MUE. The use of MMF results in comparable survival times to alternate immunosuppressive protocols.

Abstract 130: Induced Neural Stem Cell Treated Stroke Pigs Show Improved White Matter Integrity and Brain Metabolism Post-ischemic Stroke

Recent studies in rodent stroke models have shown that induced pluripotent stem cell derived neural stem cells (iNSCs) can lead to a significant decrease in lesion size, immune response and improvement in functional deficits. These improvements are linked to the iNSC potential dual mode of action as they can perform as a cell replacement therapy and produce neuroprotective and regenerative signaling. These results are promising yet the vast majority of therapies developed in rodent stroke models have failed to translate in clinical trials; suggesting that iNSC therapy should be tested in a more human like model such as the pig. We hypothesize that iNSC treatment will lead to improved white matter integrity, brain metabolism and cerebral blood flow (CBF) as determined by magnetic resonance imaging and spectroscopy (MRI and MRS) in stroked pigs. Eight male landrace pigs underwent middle cerebral artery occlusion stroke surgery. After 5 days, 4 pigs received iNSCs intraparenchymal injections and 4 pigs received vehicle only injections. Pigs underwent MRI and MRS assessment at 24 hrs post-injury and 1, 4 and 12 wks post-injection. MRI results at 24 hrs showed that all pigs had an ischemic stroke. At 1 wk post-injection, fractional anisotropy measurements of white matter integrity showed the affected side of the brain was 71% and 52% of normal, non-treated and treated respectively. At 12 wks, iNSC treated pigs showed a significant improvement in FA at 93% of normal, while non-treated pigs showed no improvement. MRS results demonstrated a significant decrease in NAA, Cr and Cho at 1 wk post-injection in treated and non-treated pigs. However, treated pigs showed a significant improvement in NAA, Cr and Cho at 12 wks post-injection, while non-treated pigs showed no improvement. At 12 wks, ischemic tissue in iNSC treated pigs had trending increases in CBF, while non-treated pigs showed no improvement. These results demonstrated that iNSC treated stroke pigs show improved white matter integrity, brain metabolism and CBF post-ischemic stroke and that iNSCs may one day be a viable clinical option for human stroke patients.