MYCN immunohistochemistry as surrogate marker for MYCN-amplified spinal ependymomas

MYCN (master regulator of cell cycle entry and proliferative metabolism) gene amplification defines a molecular subgroup of spinal cord ependymomas that show high-grade morphology and aggressive behavior. Demonstration of MYCN amplification by DNA methylation or fluorescence-in situ hybridization (FISH) is required for diagnosis. We aimed to (i) assess prevalence and clinicopathological features of MYCN-amplified spinal ependymomas and (ii) evaluate utility of immunohistochemistry (IHC) for MYCN protein as a surrogate for molecular testing. A combined retrospective-prospective study spanning 8 years was designed during which all spinal cord ependymomas with adequate tissue were subjected to MYCN FISH and MYCN IHC. Among 77 spinal cord ependymomas included, MYCN amplification was identified in 4 samples from 3 patients (3/74, 4%) including two (1st and 2nd recurrences) from the same patient. All patients were adults (median age at diagnosis of 32 years) including two females and one male. The index tumors were located in thoracic (n = 2) and lumbar (n = 1) spinal cord. One of the female patients had neurofibromatosis type 2 (NF2). All four tumors showed anaplastic histology. Diffuse expression of MYCN protein was seen in all four MYCN-amplified samples but in none of the non-amplified cases, thus showing 100% concordance with FISH results. On follow-up, the NF2 patient developed widespread spinal dissemination while another developed recurrence proximal to the site of previous excision. To conclude, MYCN-amplified spinal ependymomas are rare tumors, accounting for ~ 4% of spinal cord ependymomas. Within the limitation of small sample size, MYCN IHC showed excellent concordance with MYCN gene amplification.

A case of disseminated cryptococcosis with abdominal involvement due to Cryptococcus neoformans species complex in a Ragdoll cat and false-negative cryptococcal antigen lateral flow tests due to the postzone phenomenon

Although cryptococcosis is the most common systemic fungal disease of cats, abdominal involvement is rarely reported. The pathogenesis of cryptococcosis usually involves sinonasal colonisation, followed by tissue invasion and sinonasal infection, with possible subsequent spread to the lungs and/or direct extension into the central nervous system (CNS), for example, via the cribriform plate. Further haematogenous spread can occur to any tissue, including skin and the CNS. This report describes a case of disseminated cryptococcosis due to Cryptococcus neoformans species complex in a 13-year-old cat, the fourth documented Australian feline case with abdominal involvement. The cat presented with a chronic history of upper respiratory disease that progressed to severe lethargy and anorexia. An autopsy revealed striking peritonitis with multifocal abdominal involvement affecting the liver, spleen, adrenal glands, kidneys, pancreas and mesentery. Cryptococcal organisms were also observed in organs within the thoracic cavity, sinonasal tissues and the CNS. Testing of abdominal fluid and serum for cryptococcal antigen using a commercially available lateral flow assay using neat fluid specimen initially tested false-negative. However, after dilution of the sample to 1:64, a positive result was obtained, confirming a postzone phenomenon. Taken together, the collective findings were indicative of widely disseminated cryptococcosis due to Cryptococcus neoformans with atypical involvement of the abdominal cavity.

AI implementation in the UK landscape: Knowledge of AI governance, perceived challenges and opportunities, and ways forward for radiographers

INTRODUCTION

Despite the rapid increase of AI-enabled applications deployed in clinical practice, many challenges exist around AI implementation, including the clarity of governance frameworks, usability of validation of AI models, and customisation of training for radiographers. This study aimed to explore the perceptions of diagnostic and therapeutic radiographers, with existing theoretical and/or practical knowledge of AI, on issues of relevance to the field, such as AI implementation, including knowledge of AI governance and procurement, perceptions about enablers and challenges and future priorities for AI adoption.

METHODS

An online survey was designed and distributed to UK-based qualified radiographers who work in medical imaging and/or radiotherapy and have some previous theoretical and/or practical knowledge of working with AI. Participants were recruited through the researchers' professional networks on social media with support from the AI advisory group of the Society and College of Radiographers. Survey questions related to AI training/education, knowledge of AI governance frameworks, data privacy procedures, AI implementation considerations, and priorities for AI adoption. Descriptive statistics were employed to analyse the data, and chi-square tests were used to explore significant relationships between variables.

RESULTS

In total, 88 valid responses were received. Most radiographers (56.6 %) had not received any AI-related training. Also, although approximately 63 % of them used an evaluation framework to assess AI models' performance before implementation, many (36.9 %) were still unsure about suitable evaluation methods. Radiographers requested clearer guidance on AI governance, ample time to implement AI in their practice safely, adequate funding, effective leadership, and targeted support from AI champions. AI training, robust governance frameworks, and patient and public involvement were seen as priorities for the successful implementation of AI by radiographers.

CONCLUSION

AI implementation is progressing within radiography, but without customised training, clearer governance, key stakeholder engagement and suitable new roles created, it will be hard to harness its benefits and minimise related risks.

IMPLICATIONS FOR PRACTICE

The results of this study highlight some of the priorities and challenges for radiographers in relation to AI adoption, namely the need for developing robust AI governance frameworks and providing optimal AI training.

A severe case of disseminated cryptococcosis in a young French bulldog living in South-East Queensland caused by Cryptococcus gattii VGII

BACKGROUND

Cryptococcus is one of the most common systemic mycosis worldwide, infecting young adults of the large to giant breed dogs. Infection is commonly acquired from the environment via the sinonasal cavity as the main portal of entry. It either remains there, or spreads to the central nervous system (CNS) and the eye (optic nerve and retina) by penetration of the cribriform plate, or haematogenously to other viscera. Lung involvement is uncommon in cats and dogs in contrast to human and equine patients. Whilst there is a wide genetic diversity amongst Cryptococcus neoformans and Cryptococcus gattii isolates along the West Coast and Northern parts of Australia, the molecular diversity of C. gatti is considered very low on the East Coast of Australia, with a huge preponderance of VGI cases. We report on a young small breed brachycephalic dog that presented with extreme gastrointestinal and respiratory signs, but no CNS involvement. It is the first reported case of C. gattii VGII genotype in a companion animal from Queensland.

CASE REPORT

A 9-month old female entire French Bulldog presented initially for diarrhoea. Clinical progression was accompanied by the development of respiratory signs, so the patient was referred to a 24 h care facility. Following hospitalisation, the patient became hypoxemic requiring mechanical ventilation. A bronchoalveolar lavage performed antemortem confirmed abundant Cryptococcal spp. Further culturing and genotyping identified the species as Cryptococcus gattii VGII. Post-mortem findings indicated gross gastrointestinal and mesenteric involvement, with possible dissemination to the local mesenteric lymph node and lungs.

CONCLUSION

This case describes a rare example of a Cryptococcus spp suspected of disseminating from the gastrointestinal tract to the lungs, without involvement of the CNS. The observation of this finding in a small brachycephalic breed is unusual, and the finding of genotype VGII on the East Coast of Queensland is extremely unusual as there is no prior travel history of the dog or owners. The presence of a miliary lung pattern with primary gastrointestinal disease in a small breed dog warrants adding cryptococcosis to the differential diagnosis.

Mixed-reality technology for clinical communication: objective assessment of the HoloLens 2 as a clinical communication device in a simulated on-call scenario

OBJECTIVE

Specialty on-call clinicians cover large areas and complex workloads. This study aimed to assess clinical communication using the mixed-reality HoloLens 2 device within a simulated on-call scenario.

METHOD

This study was structured as a randomised, within-participant, controlled study. Thirty ENT trainees used either the HoloLens 2 or a traditional telephone to communicate a clinical case to a consultant. The quality of the clinical communication was scored objectively and subjectively.

RESULTS

Clinical communication using the HoloLens 2 scored statistically higher than telephone (n = 30) (11.9 of 15 vs 10.2 of 15; p = 0.001). Subjectively, consultants judged more communication episodes to be inadequate when using the telephone (7 of 30) versus the HoloLens 2 (0 of 30) (p = 0.01). Qualitative feedback indicates that the HoloLens 2 was easy to use and would add value during an on-call scenario with remote consultant supervision.

CONCLUSION

This study demonstrated the benefit that mixed-reality devices, such as the HoloLens 2 can bring to clinical communication through increasing the accuracy of communication and confidence of the users.

Hypothyroidism induces motor deficit via altered cerebellar HB-EGF/EGFR and autophagy

Thyroid hormones (TH) are vital for brain functions, while TH deficiency, i.e. hypothyroidism, induces neurological impairment in children and adults. Cerebellar neuronal apoptosis and motor deficits are crucial events in hypothyroidism; however, the underlying mechanism is less-known. Using a methimazole-treated hypothyroidism rat model, we investigated cerebellar autophagy, growth factor, and apoptotic mechanisms that participate in motor functions. We first identified that methimazole up-regulated cerebellar autophagy, marked by enhanced LC3B-II, Beclin-1, ATG7, ATG5-12, p-AMPKα/AMPKα, and p62 degradation as well as reduced p-AKT/AKT, p-mTOR/mTOR, and p-ULK1/ULK1 in developing and young adult rats. We probed upstream effectors of this abnormal autophagy and detected a methimazole-induced reduction in cerebellar phospho-epidermal growth factor receptor (p-EGFR)/EGFR and heparin-binding EGF-like growth factor (HB-EGF). Here, while a thyroxine-induced TH replenishment alleviated autophagy process and restored HB-EGF/EGFR, HB-EGF treatment regulated AKT-mTOR and autophagy signaling in the cerebellum. Moreover, neurons of the rat cerebellum demonstrated this reduced HB-EGF-dependent increased autophagy in hypothyroidism. We further checked whether the above events were related to cerebellar neuronal apoptosis and motor functions. We detected that comparable to thyroxine, treatment with HB-EGF or autophagy inhibitor, 3-MA, reduced methimazole-induced decrease in Nissl staining and increase in c-Caspase-3 and TUNEL-+ve apoptotic count of cerebellar neurons. Additionally, 3-MA, HB-EGF, and thyroxine attenuated the methimazole-induced diminution in riding time on rota-rod and grip strength for the motor performance of rats. Overall, our study enlightens HB-EGF/EGFR-dependent autophagy mechanism as a key to cerebellar neuronal loss and functional impairments in developmental hypothyroidism, which may be inhibited by HB-EGF and 3-MA treatments, like thyroxine.

Acute kidney injury in 18 cats after subcutaneous meloxicam and an update on non-steroidal anti-inflammatory drug usage in feline patients in Australia

OBJECTIVES

Acute kidney injury (AKI) is a well-known but poorly documented adverse effect of non-steroidal anti-inflammatory drugs (NSAIDs) in cats. We aimed to describe instances of NSAID-associated AKI in cats and survey Australian veterinarians on NSAID use in acute settings.

METHODS

Medical records of cats that developed an AKI subsequent to the administration of meloxicam were obtained by searching the databases of seven practices in Queensland, as well as by contemporaneously contacting select veterinary colleagues of the authors in both general and specialist small animal practice. An online questionnaire was created for the survey, and the URL distributed to Australian practitioners.

RESULTS

A total of 18 cases were retrieved, all of which received injectable meloxicam. The indication(s) for its use and the dosage prescribed were within the manufacturer's recommendations for Australian veterinarians. The majority of cases (13/18 cats) received the label dose of 0.3 mg/kg subcutaneously (SC) on the day of the procedure. In 12/18 cats, the injection was given in association with general anaesthesia or sedation. Fourteen cats survived to hospital discharge. Of 187 survey respondees, 89% routinely administered NSAIDs for surgery-related analgesia, with 98% prescribing meloxicam and 84% of these giving it SC. Ninety percent of respondees routinely administered NSAIDs for non-surgical-related analgesia, with 99% prescribing meloxicam and 35% of those giving it SC.

CONCLUSIONS AND RELEVANCE

We strongly recommend that practitioners avoid prescribing meloxicam SC in cats. This recommendation is emphatic in situations where concurrent dehydration and/or hypotension are possible.

Brucella suis in three dogs: presentation, diagnosis and clinical management

Brucella suis is an emerging, zoonotic disease predominantly affecting dogs and humans that engage in feral pig hunting in Australia and other countries. Although B. suis infection in dogs shares some clinical similarities to the host-adapted species (B. canis), B. suis remains an incompletely understood pathogen in dogs with limited published data on its pathogenesis and clinical features. This case series describes the presentations, diagnosis, and clinical management of B. suis infection in three dogs: (1) a bitch with dystocia, abortion and mastitis; (2) an entire male dog with septic arthritis and presumptive osteomyelitis; and (3) a castrated male dog with lymphadenitis. Unique features of these cases are reported including the first documented detection of B. suis from milk and isolation from lymph nodes of canine patients, as well as the follow-up of pups born to a B. suis-infected bitch. Consistent with previous reports, all three dogs showed a favourable clinical response to combination antibiotic therapy with rifampicin and doxycycline. Individually tailored drug regimens were required based on the clinical presentation and other factors, including owner expectations and compliance with therapy as well as a zoonotic risk assessment (generally considered low, except around time of whelping). The authors include their recommendations for the clinical management of dogs that are at-risk or seropositive for B. suis with or without clinical signs or laboratory-confirmed infection.

An association of VDR gene polymorphism in hypovitaminosis D mediated secondary hyperparathyroidism in adolescent girls; a tertiary hospital study in central India

Vitamin D is required to maintain normal serum calcium and phosphate levels that help normal bone mineralization, nerve conduction, muscle contraction, immune function, cell proliferation, and differentiation. Interventions including vitamin D supplementation may not improve vitamin D deficiency, as various complex genomic actions could contribute to vitamin D deficiency in the Indian population. Thus, we assessed hypovitaminosis D's relationship with vitamin D receptor (VDR) gene polymorphism and evaluated parathyroid hormone (PTH) levels in seemingly healthy adolescent school-going girls. We included 100 school-going girls (aged 12-17 years) studying in four schools of different socio-economic strata of Bhopal, India. The selected participants were divided into four groups based on the school in which they were studying. Blood samples were tested for serum calcium, phosphorus, PTH, ALP, vitamin D 25(OH) D, and albumin levels.VDR polymorphism was detected through the PCR-RFLP. Data were analyzed using the chi-square test, ANOVA, and linear regression. The difference in the age, calcium, ALP, and vitamin D values between the four groups were significant (P < 0.05), whereas high PTH levels (80%) were found. A higher prevalence of homozygous polymorphic allele demonstrates a molecular signature for severe secondary hyperparathyroidism. Hypovitaminosis D ranged from 84.9% to 100%, and a high prevalence of VDR polymorphism was observed. Attention must be paid to the health of this age group of school-going girls as hypovitaminosis D and associated VDR gene polymorphism could be the reason for secondary hyperparathyroidism (SHPT), showing changes in bone mineral density in these adolescent girls to ensure their future health.

EPEN-20. PDL1 expression and tumor-infiltrating immune cell subpopulations: The role of immune-checkpoint molecules in the prognosis of patients with supratentorial ependymoma and its correlation to survival

Immune checkpoint blockade of the programmed cell death ligand-1 (PD-L1)/programmed death-1 (PD-1) axis has shifted the way advanced cancers are treated. The 'ST-RELA fusion positive' and 'PF-A' molecular subgroups of ependymomas (EPN) have a dismal prognosis. AIMS: This study is undertaken to look for immunological microenvironment in ependymomas. Based on L1CAM protein expression and/or the presence of RELA/YAP1 fusion transcripts by RT-PCR, all supratentorial (ST) Grade-II/III EPNs were classified as ST-RELA, ST-YAP, and ST-not otherwise specified (NOS). Based on H3K27me3 protein expression and chromosome 1q gain, all posterior fossa (PF) EPNs were classified as PF-A or PF-B. PD-L1 (SP263, Ventana) and CD8 immunohistochemistry was performed. The enrichment of RelA protein at the PDL1 promoter site was investigated using chromatin immunoprecipitation-qPCR (ChIP-qPCR) in three ST-RELA samples. A total of 83 intracranial EPNs were included in our preliminary data, and we discovered that PD-L1 expression correlates with increasing cytotoxic T-lymphocyte infiltrates in intracranial ependymomas using PD-L1 and CD8 IHC. The majority of PD-L1-positive intracranial EPNs are members of the ST-RELA subset, which also has the highest CTL density. Our findings suggest that ST-RELA EPNs could be used in immunotherapy to target immune checkpoint modulators. To further this research, we are looking into the presence of tumour infiltrating cells such as CD3, CD8, CD163, FOXP3, and others, which can aid in characterising the tumour microenvironment in cell types expressing PD-L1.This study will also be used to predict the prognostic significance of PD-L1/PD1 and other tumour cell infiltrating biomarkers in ependymomas and correlate it with survival outcomes.

AB0602 Temporal artery biopsy positivity rates vary more between similar hospitals than by length, with particular variation between geographic regions

Background

Clinical practice surrounding giant cell arteritis (GCA) diagnosis, including the use of temporal artery biopsy (TAB) where appropriate, needs to be consistently accurate to minimise both GCA-related end-organ damage and unnecessary glucocorticosteroid toxicity in all patients. Despite this imperative, the delivery of such clinical care, which can be measured by diagnostic investigation performance characteristics such as TAB positivity rates, varies substantially between different hospitals as it is traditionally reliant on unstructured clinical intuition. While clinical care practices plausibly might be more consistent between neighbouring hospitals given they frequently exchange medical staff and use common teaching sources, these factors are less likely to be applicable when comparing hospitals in different geographical regions within a country, even though educational standards, online information resources, and access to clinical care should be consistent. It therefore stands to reason that variation of diagnostic practice might be greater between geographically distant hospitals.

Objectives

To compare clinical practice surrounding GCA diagnosis, using TAB positivity rates, between similar hospitals in the same city and a geographically distant city in a different region, to understand the contribution of geographic separation to variance in practice.

Methods

TAB histopathological reports were reviewed at three tertiary referral hospital centres: two with neighbouring catchments in the same city, and one in a different city in a neighbouring geographical region in the same country. All three had similar resourcing and catchment demographics during the study period, and none used formal clinical risk stratification scores for GCA pre-test probability. Characteristics including age, sex, biopsy laterality, biopsy length, and hospital were captured, in addition to key histopathological features. Multivariable logistic regression with site-varying intercept was performed, using cubic splines for biopsy length to account for the non-linearity observed.

Results

TAB reports from 708 patients were captured between the three hospitals in two geographical regions. All three sites had a median age of 74 years, had 67-69% of patients being female, and reported median biopsy length between 1.7-2.0cm (Table 1). Despite these similarities, they reported positivity rates varying widely (16% and 24% in Region 1, 29% in Region 2). Apart from age, hospital site was the strongest contributing factor to TAB positivity, with length having little effect outside the very extreme high end and 90% of patients had a biopsy length <4.8cm (Figure 1). For these patients, hospital site differentiated TAB positivity across all biopsy lengths, with Region 2 reporting the highest TAB positivity odds ratio of 2.39 (95%CI: 1.37-4.19).

Table 1.CharacteristicSite1Region1 N = 218Site2Region1 N = 361Site1Region2 N = 129Bilateral laterality (%)66 (30%)105 (29%)1 (0.8%)Biopsy length (cm, median (IQR))2.0 (1.4, 3.0)1.7 (1.2, 3.5)1.7 (1.4, 2.2)Female sex (%)149 (68%)249 (69%)86 (67%)Age (y, median (IQR))74 (65, 81)74 (65, 80)74 (68, 81)TAB positivity (%)34 (16%)88 (24%)38 (29%)Figure 1.

Marginal probabilities of positive TAB obtained from the multivariable logistic regression model (A) across biopsy lengths, with 80% of observed lengths falling between the two vertical red lines (10% and 90% deciles); (B) across hospital sites; (C) across patient age.

Conclusion

Hospital site contributes more greatly to variation in GCA diagnosis clinical practice than demographics or other clinical features do, with particular variation between geographic regions. As part of clinical care standards, using a replicable pre-test GCA probability score1 to select patients is likely to be as important to diagnosis as the diagnostic tool characteristics themselves.

References

[1]Laskou F, et al. A probability score to aid the diagnosis of suspected giant cell arteritis. Clin Exp Rheumatol. 2019 Jan 1;37(Suppl 117):104-8.

Disclosure of Interests

None declared

Detection of Brucella spp. during a serosurvey of pig-hunting and regional pet dogs in eastern Australia

Brucellosis is a zoonotic disease with worldwide distribution. Brucella suis serotype 1 is thought to be maintained in the Australian feral pig population, with disease prevalence higher in Queensland (Qld) than New South Wales (NSW). Pig hunting is a popular recreational activity in rural Qld and NSW, with feral pigs in these states thought to carry B. suis. Brucellosis associated with B. suis has been diagnosed in dogs engaged in pig hunting in some of these areas. A total of 431 dogs from northern Qld and north‐west NSW were recruited. Two distinct cohorts of clinically healthy dogs were tested – (1) 96 dogs from central, north and far north Queensland actively engaged in pig‐hunting and (2) 335 dogs from rural and remote north‐west NSW that were primarily companion (non‐pig hunting) animals. Serum samples were tested for antibodies to Brucella spp. using the Rose Bengal test (RBT) test followed by complement fixation testing (CFT) for RBT‐positive samples. A subset of samples was retested using RBT and CFT. Seven dogs were considered seropositive for B. suis from Qld and remote NSW, including 4/96 (4.2%; 95% CI 3.5% to 4.3%) from the pig‐hunting cohort and 3/335 (0.9%) from the regional pet dog cohort. The use of RBT and CFT in dogs to detect anti‐Brucella antibodies requires validation. Veterinarians treating pig‐hunting dogs and physicians treating pig hunters in central, north and far north Qld need to be aware of the zoonotic risk posed by B. suis to these groups.

Feline immunodeficiency virus (FIV) infection in domestic pet cats in Australia and New Zealand: Guidelines for diagnosis, prevention and management

Despite the passage of over 30 years since its discovery, the importance of feline immunodeficiency virus (FIV) on the health and longevity of infected domestic cats is hotly debated amongst feline experts. Notwithstanding the absence of good quality information, Australian and New Zealand (NZ) veterinarians should aim to minimise the exposure of cats to FIV. The most reliable way to achieve this goal is to recommend that all pet cats are kept exclusively indoors, or with secure outdoor access (e.g., cat enclosures, secure gardens), with FIV testing of any in‐contact cats. All animal holding facilities should aim to individually house adult cats to limit the spread of FIV infection in groups of animals that are stressed and do not have established social hierarchies. Point‐of‐care (PoC) FIV antibody tests are available in Australia and NZ that can distinguish FIV‐infected and uninfected FIV‐vaccinated cats (Witness™ and Anigen Rapid™). Although testing of whole blood, serum or plasma remains the gold standard for FIV diagnosis, PoC testing using saliva may offer a welfare‐friendly alternative in the future. PCR testing to detect FIV infection is not recommended as a screening procedure since a negative PCR result does not rule out FIV infection and is only recommended in specific scenarios. Australia and NZ are two of three countries where a dual subtype FIV vaccine (Fel‐O‐Vax® FIV) is available and offers a further avenue for disease prevention. Since FIV vaccination only has a reported field effectiveness of 56% in Australia, and possibly lower in NZ, FIV‐vaccinated cats should undergo annual FIV testing prior to annual FIV re‐vaccination using a suitable PoC kit to check infection has not occurred in the preceding year. With FIV‐infected cats, clinicians should strive to be even more thorough than usual at detecting early signs of disease. The most effective way to enhance the quality of life and life expectancy of FIV‐infected cats is to optimise basic husbandry and to treat any concurrent conditions early in the disease course. Currently, no available drugs are registered for the treatment of FIV infection. Critically, the euthanasia of healthy FIV‐infected cats, and sick FIV‐infected cats without appropriate clinical investigations, should not occur.

Seroprevalence of Coxiella burnetii in pig-hunting dogs from north Queensland, Australia

The causative agent of Q fever, Coxiella burnetii, is endemic to Queensland and is one of the most important notifiable zoonotic diseases in Australia. The reservoir species for C. burnetii are classically ruminants, including sheep, cattle and goats. There is increasing evidence of C. burnetii exposure in dogs across eastern and central Australia. The present study aimed to determine if pig-hunting dogs above the Tropic of Capricorn in Queensland had similar rates of C. burnetii exposure to previous serosurveys of companion dogs in rural north-west New South Wales. A total of 104 pig-hunting dogs had serum IgG antibody titres to phase I and phase 2 C. burnetii determined using an indirect immunofluorescence assay test. Almost one in five dogs (18.3%; 19/104; 95% confidence interval 9.6%-35.5%) were seropositive to C. burnetii, with neutered dogs more likely to test positive compared to entire dogs (P = 0.0497). Seropositivity of the sampled pig-hunting dogs was one of the highest recorded in Australia. Thirty-nine owners of the pig-hunting dogs completed a survey, revealing 12.8% (5/39) had been vaccinated against Q fever and 90% (35/39) were aware that both feral pigs and dogs could potentially be sources of C. burnetii. Our findings indicate that pig hunters should be aware of the risk of exposure to Q fever during hunts and the sentinel role their dogs may play in C. burnetii exposure.

Presumptive neural microsporidiosis in a young adult German Shepherd dog from rural Australia

CASE REPORT

A 1-year-old, neutered male German Shepherd was presented with a 5-month history of episodic lethargy, intermittent fever, weight loss and a hunched posture. The dog was diagnosed with presumptive microsporidian meningoencephalitis based on cytological findings on cerebrospinal fluid analysis and a positive PCR test. The dog initially responded favourably to a 4-week course of trimethoprim-sulfadiazine, pyrimethamine and fenbendazole, and remained well for 12 weeks following cessation of treatment. Disease then recurred, and despite an initial positive response to treatment, he deteriorated and was euthanased 11 weeks later, 7.5 months after definitive diagnosis and 13 months after clinical signs were first reported.

CONCLUSION

To the authors knowledge, this is the first case of canine microsporidiosis in Australia.

Cardiometabolic traits mediating the effect of education on osteoarthritis risk: a Mendelian randomization study

OBJECTIVE

To investigate which cardiometabolic factors underlie clustering of osteoarthritis (OA) with cardiovascular disease, and the extent to which these mediate an effect of education.

DESIGN

Genome-wide association study (GWAS) of OA was performed in UK Biobank (60,800 cases and 328,251 controls) to obtain genetic association estimates for OA risk. Genetic instruments and association estimates for body mass index (BMI), low-density lipoprotein cholesterol (LDL-C), systolic blood pressure (SBP), smoking and education were obtained from existing GWAS summary data (sample sizes 188,577-866,834 individuals). Two-sample Mendelian randomization (MR) analyses were performed to investigate the effects of exposure traits on OA risk. MR mediation analyses were undertaken to investigate whether the cardiometabolic traits mediate any effect of education on OA risk.

RESULTS

MR analyses identified protective effects of higher genetically predicted education (main MR analysis odds ratio (OR) per standard deviation increase 0.59, 95% confidence interval (CI) 0.54-0.64) and LDL-C levels (OR 0.94, 95%CI 0.91-0.98) on OA risk, and unfavourable effects of higher genetically predicted BMI (OR 1.82, 95%CI 1.73-1.92) and smoking (OR 2.23, 95%CI 1.85-2.68). There was no strong evidence of an effect of genetically predicted SBP on OA risk (OR 0.98, 95% CI 0.90-1.06). The proportion of the effect of genetically predicted education mediated through genetically predicted BMI and smoking was 35% (95%CI 13-57%).

CONCLUSIONS

These findings highlight education, obesity and smoking as common mechanisms underlying OA and cardiovascular disease. These risk factors represent clinical and public health targets for reducing multi-morbidity related to the burden these common conditions.

Hypothyroidism Induces Interleukin-1-Dependent Autophagy Mechanism as a Key Mediator of Hippocampal Neuronal Apoptosis and Cognitive Decline in Postnatal Rats

Thyroid hormone (TH) is essential for brain development, and hypothyroidism induces cognitive deficits in children and young adults. However, the participating mechanisms remain less explored. Here, we examined the molecular mechanism, hypothesizing the involvement of a deregulated autophagy and apoptosis pathway in hippocampal neurons that regulate cognitive functions. Therefore, we used a rat model of developmental hypothyroidism, generated through methimazole treatment from gestation until young adulthood. We detected that methimazole stimulated the autophagy mechanism, characterized by increased LC3B-II, Beclin-1, ATG7, and ATG5-12 conjugate and decreased p-mTOR/mTOR and p-ULK1/ULK1 autophagy regulators in the hippocampus of developing and young adult rats. This methimazole-induced hippocampal autophagy could be inhibited by thyroxine treatment. Subsequently, probing the upstream mediators of autophagy revealed an increased hippocampal neuroinflammation, marked by upregulated interleukin (IL)-1alpha and beta and activated microglial marker, Iba1, promoting neuronal IL-1 receptor-1 expression. Hence, IL-1R-antagonist (IL-1Ra), which reduced hippocampal neuronal IL-1R1, also inhibited the enhanced autophagy in hypothyroid rats. We then linked these events with hypothyroidism-induced apoptosis and loss of hippocampal neurons, where we observed that like thyroxine, IL-1Ra and autophagy inhibitor, 3-methyladenine, reduced the cleaved caspase-3 and TUNEL-stained apoptotic neurons and enhanced Nissl-stained neuronal count in methimazole-treated rats. We further related these molecular results with cognition through Y-maze and passive avoidance tests, demonstrating an IL-1Ra and 3-methyladenine-mediated improvement in learning-memory performances of the hypothyroid rats. Taken together, our study enlightens the critical role of neuroinflammation-dependent autophagy mechanism in TH-regulated hippocampal functions, disrupted in developmental hypothyroidism.

Cardiovascular outcomes in patients with type 2 diabetes and reduced eGFR and albuminuria: a REWIND post hoc subgroup analysis

Background/Introduction

Diabetic kidney disease affects up to 40% of people with diabetes and is associated with higher cardiovascular (CV) risk. REWIND was a multicentre, randomised, double-blind, placebo-controlled trial with a primary outcome of first occurrence of the composite endpoint of CV death, nonfatal myocardial infarction, or nonfatal stroke (Major Adverse Cardiovascular Event [MACE]-3). Dulaglutide treatment reduced the incidence of MACE-3 in patients with type 2 diabetes (T2D) with or without established CV disease.

Purpose

This REWIND post hoc subgroup analysis evaluated the effect of dulaglutide on MACE-3 in patients with an eGFR&lt;60 and ≥60 mL/min/1.73m2 and patients with micro-/macro-albuminuria (UACR ≥30 mg/g) or normoalbuminuria (UACR &lt;30 mg/g).

Methods

Eligible patients were those ≥50 years old with T2D who had either a previous CV event or CV risk factors. Patients were randomised (1:1) to dulaglutide 1.5 mg or placebo, both in addition to standard of care. A Cox proportional hazards model with treatment, eGFR subgroup (&lt;60 and ≥60 mL/min/1.73 m2), and treatment by eGFR subgroup interaction was used to analyse time to the first occurrence of MACE-3. These analyses were also conducted for albuminuria subgroups (micro-/macro-albuminuria or normoalbuminuria). Estimates of hazard ratios (HR) with 95% confidence intervals (CI) were calculated for each subgroup.

Results

At baseline, 2,199 of 9,901 patients (22.2%) had an eGFR &lt;60 mL/min/1.73 m2, 2,676 (27.0%) had microalbuminuria, and 791 (8.0%) had macroalbuminuria. This post hoc subgroup analysis showed that dulaglutide treatment was consistently associated with MACE-3 risk reduction in patients with eGFR &lt;60 and ≥60 mL/min/1.73 m2 (HR [95% CI]: 0.93 [0.76–1.13] and 0.86 [0.75–0.99], respectively; interaction p=0.545). Similarly, MACE-3 risk reduction was consistent in patients with micro-/macro-albuminuria or normoalbuminuria (HR [95% CI]: 0.84 [0.72–0.99] and 0.93 [0.79–1.10], respectively; interaction p=0.374).

Conclusions

Regardless of baseline eGFR or albuminuria status, dulaglutide reduces MACE-3 outcomes in patients with T2D and established CV disease or multiple CV risk factors.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Eli Lilly and Company

Abdominal cryptococcosis in dogs and cats: 38 cases (2000-2018)

INTRODUCTION

To report the clinical presentation, laboratory and imaging findings, treatment and outcome of abdominal cryptococcosis in dogs and cats in Australia.

MATERIALS AND METHODS

Canine and feline cases from Australia were retrospectively identified (2000 to 2018) via laboratory and referral centre searches for abdominal cryptococcosis diagnosed by cytology (needle aspirates) or histopathology (biopsy or necropsy) of abdominal organs/tissues. Signalment, presenting complaints, clinical signs, laboratory findings, medical imaging, latex cryptococcal antigen agglutination test (LCAT) titres, treatment and outcome data was collected.

RESULTS

Thirty-eight cases were included (35 dogs, three cats) in the study. Median age of presentation was 2 years for dogs and 6 years for cats. Common presenting complaints included vomiting (23/38), lethargy (19/38) and inappetence/anorexia (15/38). Abdominal ultrasound (25/38 cases) revealed mesenteric and intestinal lesions in most of the cases. On surgical exploration, seven cases had an intestinal lesion associated with an intussusception. Nineteen cases had a pre-treatment LCAT performed, with a median initial titre of 1:2048 (range 1:2 to 65,536). Twenty-four cases (23 dogs, one cat) received treatment, either medical, surgical or both. Median survival time for cases with combined medical and surgical treatment, surgical treatment alone or medical treatment alone was 730, 140 and 561 days, respectively. Eleven remain alive at the time of follow up.

CLINICAL SIGNIFICANCE

Abdominal cryptococcosis although rare should be a considered as a diagnostic possibility in an especially young dog presenting with gastro-intestinal signs. Older dogs can also present with this condition and should not be euthanised based on imaging alone due to the likenesses with neoplasia. With appropriate treatment and monitoring many dogs may have a prolonged survival period and some may be cured.

A practical criterion for focusing of unstained cell samples using a digital holographic microscope

Digital holographic microscopy (DHM) is an important technique that may be used for quantitative phase imaging of unstained biological cell samples. Since the DHM technology is not commonly used in clinics or bioscience research labs, at present there is no well-accepted focusing criterion for unstained samples that users can follow while recording image plane digital holograms of cells. The usual sharpness metrics that are useful for auto-focusing of stained cells do not work well for unstained cells as there is no amplitude contrast. In this work, we report a practical method for estimating the best focus plane for unstained cells in the digital hologram domain. The method is based on an interesting observation that for the best focus plane the fringe pattern associated with individual unstained cells predominantly shows phase modulation effect in the form of bending of fringes and minimal amplitude modulation. This criterion when applied to unstained red blood cells shows that the central dip in the doughnut-like phase profile of cells is maximal in this plane. The proposed methodology is helpful for standardizing the usage of DHM technology across different users and application development efforts. LAY DESCRIPTION: Digital holographic microscopy (DHM) is slowly but steadily becoming an important microscopy modality and gaining acceptability for basic bio-science research as well as clinical usage. One of the important features of DHM is that it allows users to perform quantitative imaging of unstained transparent cells. Instead of using dyes or fluorescent labelling, DHM systems use quantitative phase as a contrast mechanism which depends on the natural refractive index variation within the cell samples. Since minimal wet lab processing is required in order to image cell samples with a DHM, cells can be imaged in their natural state. While DHM is gaining popularity among users, the imaging protocols across the labs or users need to be standardized in order to make sure that the same quantitative phase parameters are used for tasks such as quantitative phased based cell classification. One of the important operational tasks for any microscopy work is to focus the sample under study. While focusing comes naturally to users of brightfield microscopes based on image contrast, the focusing is not straightforward when samples are unstained so that they do not offer any amplitude contrast. When performing quantitative phase imaging, defocus can actually change the phase profile of the cell due to near-zone (Fresnel) diffraction effects. So unless a standardized focusing methodology is used, it will be difficult for multiple DHM users (potentially at different sites) to agree on quantitative results out of their phase images. DHM literature has prior works which perform numerical focusing of recovered complex wave-field in the hologram plane to find the best focus plane. However such methods are not user friendly and do not allow user the same focusing experience as in a brightfield microscope. The numerical focusing is therefore a reasonably good method for an optics researcher but not necessarily so for a microscopy technician looking at cell samples with a DHM system in a clinical setting. The present work provides a simple focusing criterion for unstained samples that works directly in the hologram domain. The technique is based on an interesting observation that the when an unstained cell sample is in the best-focus plane, its corresponding hologram (or fringe pattern) predominantly shows phase modulation manifested by bending of fringes at the location of the cell. This criterion can be converted into a simple numerical method as we have used to find the best-focus plane using a stack of through focus holograms. We believe that the technique can be used manually by visually observing the holograms or can be converted to an auto-focus algorithm for a motorized DHM system.

Rigidity controls human desmoplastic matrix anisotropy to enable pancreatic cancer cell spread via extracellular signal-regulated kinase 2

It is predicted that pancreatic ductal adenocarcinoma (PDAC) will become the second most lethal cancer in the US by 2030. PDAC includes a fibrous-like stroma, desmoplasia, encompassing most of the tumor mass, which is produced by cancer-associated fibroblasts (CAFs) and includes their cell-derived extracellular matrices (CDMs). Since elimination of desmoplasia has proven detrimental to patients, CDM reprogramming, as opposed to stromal ablation, is therapeutically desirable. Hence, efforts are being made to harness desmoplasia's anti-tumor functions. We conducted biomechanical manipulations, using variations of pathological and physiological substrates in vitro, to culture patient-harvested CAFs and generate CDMs that restrict PDAC growth and spread. We posited that extrinsic modulation of the environment, via substrate rigidity, influences CAF's cell-intrinsic forces affecting CDM production. Substrates used were polyacrylamide gels of physiological (~1.5 kPa) or pathological (~7 kPa) stiffnesses. Results showed that physiological substrates influenced CAFs to generate CDMs similar to normal/control fibroblasts. We found CDMs to be softer than the corresponding underlying substrates, and CDM fiber anisotropy (i.e., alignment) to be biphasic and informed via substrate-imparted morphological CAF aspect ratios. The biphasic nature of CDM fiber anisotropy was mathematically modeled and proposed a correlation between CAF aspect ratios and CDM alignment; regulated by extrinsic and intrinsic forces to conserve minimal free energy. Biomechanical manipulation of CDMs, generated on physiologically soft substrates, leads to reduction in nuclear translocation of pERK1/2 in KRAS mutated pancreatic cells. ERK2 was found essential for CDM-regulated tumor cell spread. In vitro findings correlated with in vivo observations; nuclear pERK1/2 is significantly high in human PDAC samples. The study suggests that altering underlying substrates enable CAFs to remodel CDMs and restrict pancreatic cancer cell spread in an ERK2 dependent manner.

Rheumatoid Keratolysis: A Series of 40 Eyes

PURPOSE

Rheumatoid keratolysis (RK) is a rare but a serious cause of ocular morbidity in rheumatoid patients. The aim of this study was to analyze the presenting features, the subsequent treatment, and the outcome of patients with RK in the authors' department.

METHODS

A retrospective study was undertaken of all patients with a diagnosis of RK at Bristol Eye Hospital between January 1987 and June 2002.

RESULTS

Forty eyes of 38 patients were identified in total. The mean age at presentation was 70 years. The mean duration of rheumatoid arthritis at presentation was 15 years. Most (22, 55%) ulcers were peripheral. Three patients (8%) developed RK within a month of cataract surgery. Out of the 19 patients who did not have a further RK, 11 were immunosuppressed. A total of 37 grafts were performed on 26 eyes. Twenty-two grafts (59%) failed. Immunosuppression increased the chance of anatomical success following penetrating keratoplasty. Infection was identified as a cause of graft failure for immunosuppressed patients in the postoperative period. Nine patients had reversible side effects from immunosuppressant treatment. Four eyes (10%) had to be surgically removed and a further 10 (25%) had severe visual loss (visual acuity less than 6/60). Eleven of the 38 patients subsequently died (29% mortality).

CONCLUSIONS

Although the visual prognosis is often poor, surgical preservation of the eye can be achieved by penetrating keratoplasty and systemic immunosuppression. With careful observation and regular monitoring, immunosuppressive medication appears to be safely tolerated in this group of patients.

Binder-free Sn–Si heterostructure films for high capacity Li-ion batteries

This study fabricated and demonstrated a functional, stable electrode structure for a high capacity Li-ion battery (LIB) anode. Effective performance is assessed in terms of reversible lithiation for a significant number of charge–discharge cycles to 80% of initial capacity. The materials selected for this study are silicon and tin and are co-deposited using an advanced manufacturing technique (plasma-enhanced chemical vapour deposition), shown to be a scalable process that can facilitate film growth on 3D substrates. Uniform and hybrid crystalline–amorphous Si nanowire (SiNW) growth is achieved via a vapour–liquid–solid mechanism using a Sn metal catalyst. SiNWs of less than 300 nm diameter are known to be less susceptible to fracture and when grown this way have direct electrical conductivity to the current collector, with sufficient room for expansion. Electrochemical characterisation shows stable cycling at capacities of 1400 mA h g⁻¹ (>4 × the capacity limit of graphite). This hybrid system demonstrates promising electrochemical performance, can be grown at large scale and has also been successfully grown on flexible carbon paper current collectors. These findings will have impact on the development of flexible batteries and wearable energy storage.

This study fabricated and demonstrated a functional, stable electrode structure for a high capacity Li-ion battery (LIB) anode.

Subclinical cardiovascular disease in patients with chronic obstructive pulmonary disease: a systematic review

BACKGROUND

Cardiovascular disease (CVD) accounts for a significant portion of deaths in patients with COPD; however, evidence for early detection strategies for CVD in this population remain limited. Our paper aims to summarize existing data regarding subclinical CVD in patients with COPD with a view to identifying screening strategies in these patients.

METHODS

A systematic review of published literature was conducted for studies examining the relationship of COPD and markers of subclinical disease such as coronary artery calcification (CAC), carotid intima media thickness (cIMT), endothelial dysfunction, arterial stiffness as measured by pulse wave velocity (PWV) and augmentation indices (AIx). Both MEDLINE and EMBASE databases were searched till October 2015.

RESULTS

A total of 22 studies were included in the review. Compared with control subjects, patients with COPD had significantly higher cIMT (SMD 0.53, 95% CI 0.16-0.90), PWV (SMD 0.91, 95% CI 0.67-1.16) and AIx (SMD 0.86, 95% CI 0.52-1.19). Additionally, an overall higher prevalence of subclinical CVD as assessed by CAC, ABI and FMD was noted in our review.

CONCLUSION

Although our findings need further evaluation in prospective studies, our review presents significant evidence in support of increased subclinical CVD burden in COPD patients independent of smoking status. Further large-scale case-control studies are required to highlight the significance of subclinical CVD screening in COPD patients.

Antimicrobial Prescribing in Dogs and Cats in Australia: Results of the Australasian Infectious Disease Advisory Panel Survey

Background

Investigations of antimicrobial use in companion animals are limited. With the growing recognition of the need for improved antimicrobial stewardship, there is urgent need for more detailed understanding of the patterns of antimicrobial use in this sector.

Objectives

To investigate antimicrobial use for medical and surgical conditions in dogs and cats by Australian veterinarians.

Methods

A cross‐sectional study was performed over 4 months in 2011. Respondents were asked about their choices of antimicrobials for empirical therapy of diseases in dogs and cats, duration of therapy, and selection based on culture and susceptibility testing, for common conditions framed as case scenarios: 11 medical, 2 surgical, and 8 dermatological.

Results

A total of 892 of the 1,029 members of the Australian veterinary profession that completed the survey satisfied the selection criteria. Empirical antimicrobial therapy was more common for acute conditions (76%) than chronic conditions (24%). Overall, the most common antimicrobial classes were potentiated aminopenicillins (36%), fluoroquinolones (15%), first‐ and second‐generation cephalosporins (14%), and tetracyclines (11%). Third‐generation cephalosporins were more frequently used in cats (16%) compared to dogs (2%). Agreement with Australasian Infectious Disease Advisory Panel (AIDAP) guidelines (generated subsequently) was variable ranging from 0 to 69% between conditions.

Conclusions and Clinical Importance

Choice of antimicrobials by Australian veterinary practitioners was generally appropriate, with relatively low use of drugs of high importance, except for the empirical use of fluoroquinolones in dogs, particularly for otitis externa and 3rd‐generation cephalosporins in cats. Future surveys will determine whether introduction of the 2013 AIDAP therapeutic guidelines has influenced prescribing habits.

Abstract P6-12-05: Targeting estrogen receptor mutations for treatment of endocrine therapy resistance in breast cancer

This abstract was withdrawn by the authors.

Epidemiological investigation of grass seed foreign body-related disease in dogs of the Riverina District of rural Australia

OBJECTIVE

To characterise disease presentations caused by grass seed foreign body-related disease (GSFBD) in dogs, identify predisposing risk factors and suggest effective prevention strategies.

METHODS

A retrospective, case-control, telephone survey was conducted to obtain information on GSFBD in dogs from the Riverina district of New South Wales (NSW). Additionally, retrospective case records were obtained from Wagga Wagga Veterinary Hospital and Charles Sturt University Veterinary Teaching Hospital over the period July 2006 to October 2011. Signalment, history, investigative strategies, location and severity of lesion(s), cost of therapy, length of hospitalisation, recurrence rate and microbiology data were recorded.

RESULTS

Cases (473 dogs) meeting stringent inclusion criteria were identified. GSFBD comprised 2.0% of hospital presentations. Breeds with high-density coats were overrepresented. Otitis externa was the most common manifestation of GSFBD in the general practice (47%). In the referral practice pyothorax was the most common entity (34%). In both practices the range of clinical manifestations was broad, including a small number of dogs with catastrophic intracranial disease. Univariable and multivariable logistic regression analyses demonstrated dogs with GSFBD had 3-fold greater odds of having medium coats than short coats and 5-fold less odds of being groomed.

CONCLUSIONS AND CLINICAL RELEVANCE

Grass seeds are a major cause of disease in the dogs of south-west rural NSW, with presentations ranging from mild lameness to severe neurological disease. Some protection from GSFBD was achieved with frequent grooming. Clipping or coat searching without grooming was ineffective as a prevention strategy.