Centrosome amplification promotes cell invasion via cell-cell contact disruption and Rap-1 activation.

Centrosome amplification (CA) is a prominent feature of human cancers linked to tumorigenesis in vivo. Here, we report mechanistic contributions of CA induction alone to tumour architecture and extracellular matrix (ECM) remodelling. CA induction in non-tumorigenic breast cells MCF10A causes cell migration and invasion, with underlying disruption of epithelial cell-cell junction integrity and dysregulation of expression and subcellular localisation of cell junction proteins. CA also elevates expression of integrin ß-3, its binding partner fibronectin-1 and matrix metalloproteinase enzymes, promoting cell-ECM attachment, ECM degradation, and a migratory and invasive cell phenotype. Using a chicken embryo xenograft model for in vivo validation, we show that CA-induced (+CA) MCF10A cells invade into the chick mesodermal layer, with inflammatory cell infiltration and marked focal reactions between chorioallantoic membrane and cell graft. We also demonstrate a key role of small GTPase Rap-1 signalling through inhibition using GGTI-298, which blocked various CA-induced effects. These insights reveal that in normal cells, CA induction alone (without additional oncogenic alterations) is sufficient to confer early pro-tumorigenic changes within days, acting through Rap-1-dependent signalling to alter cell-cell contacts and ECM disruption.

On-Off and Proportional Closed-Loop Adaptive Deep Brain Stimulation Reduces Motor Symptoms in Freely Moving Hemiparkinsonian Rats.

OBJECTIVES: Closed-loop adaptive deep brain stimulation (aDBS) continuously adjusts stimulation parameters, with the potential to improve efficacy and reduce side effects of deep brain stimulation (DBS) for Parkinson's disease (PD). Rodent models can provide an effective platform for testing aDBS algorithms and establishing efficacy before clinical investigation. In this study, we compare two aDBS algorithms, on-off and proportional modulation of DBS amplitude, with conventional DBS in hemiparkinsonian rats. MATERIALS AND METHODS: DBS of the subthalamic nucleus (STN) was delivered wirelessly in freely moving male and female hemiparkinsonian (N = 7) and sham (N = 3) Wistar rats. On-off and proportional aDBS, based on STN local field potential beta power, were compared with conventional DBS and three control stimulation algorithms. Behavior was assessed during cylinder tests (CT) and stepping tests (ST). Successful model creation was confirmed via apomorphine-induced rotation test and Tyrosine Hydroxylase-immunocytochemistry. Electrode location was histologically confirmed. Data were analyzed using linear mixed models. RESULTS: Contralateral paw use in parkinsonian rats was reduced to 20% and 25% in CT and ST, respectively. Conventional, on-off, and proportional aDBS significantly improved motor function, restoring contralateral paw use to approximately 45% in both tests. No improvement in motor behavior was observed with either randomly applied on-off or low-amplitude continuous stimulation. Relative STN beta power was suppressed during DBS. Relative power in the alpha and gamma bands decreased and increased, respectively. Therapeutically effective adaptive DBS used approximately 40% less energy than did conventional DBS. CONCLUSIONS: Adaptive DBS, using both on-off and proportional control schemes, is as effective as conventional DBS in reducing motor symptoms of PD in parkinsonian rats. Both aDBS algorithms yield substantial reductions in stimulation power. These findings support using hemiparkinsonian rats as a viable model for testing aDBS based on beta power and provide a path to investigate more complex closed-loop algorithms in freely behaving animals.

Exudative glomerulonephritis associated with acute leptospirosis in dogs.

In the past 20 years in Switzerland, dogs with suspect acute leptospirosis frequently showed severe glomerular changes that had not been previously reported. These features were characterized by abundant extravasated erythrocytes and fewer neutrophils accompanied by marked fibrin exudation into the urinary space that was interpreted as an exudative glomerulonephritis (GN). This retrospective study describes this significant glomerular pathological change and investigates the association with leptospirosis. Tissues from 50 dogs with exudative GN, retrieved from 2 pathology archives in Switzerland were reviewed using hematoxylin and eosin, periodic acid-Schiff, phosphotungstic acid-hematoxylin, and Warthin and Starry stains. Clinical and postmortem data were collected for each case. Immunohistochemistry (IHC) and/or polymerase chain reactions were used as confirmatory tests for leptospirosis. While all 50 cases had clinical and pathological features supporting a diagnosis of leptospirosis, 37 cases were confirmed for the disease. Using a LipL32 antibody in addition to the OMV2177 antibody raised against the lipopolysaccharide of Leptospira interrogans serovar Copenhageni increased the detection rate of Leptospira by IHC in exudative GN from 24% to 62%. Signalment, seasonality, clinical signs, blood results, and pathological changes in dogs with exudative GN were similar to those reported for dogs without GN and confirmed infection by Leptospira spp.. Exudative GN was common among Swiss dogs with leptospirosis where it caused acute severe disease. Leptospirosis should be considered as a cause of this new pathologic feature by the pathologist. The pathogenesis remains unclear, but involvement of a geographic-specific serovar with unique virulence factors is suspected and warrants further investigation.

Evaluation of Student Engagement, Communication, and Collaboration during Online Group Work: Experiences of Fourth Year Veterinary Medicine Students.

Accelerated by the COVID-19 pandemic, online teaching has become widely established in higher education in recent years. However, little is known about the influence of the online environment on collaborative student activities which are an integral part of veterinary education. This study explored engagement, collaboration, and communication among fourth-year veterinary students working in groups on online case-based learning (CBL) activities. Data were collected by questionnaire (93/135) and anonymous peer assessment (98/135) at the end of the trimester. While most students (67%) enjoyed group work and 75% considered it of benefit to their learning, the results indicated that the students' interaction was mainly limited to task management and collating individual answers on shared documents. Rather than meeting online, students communicated by chat and messenger apps. Agreement of roles, rules, and the group contract were largely treated as box-ticking exercises. The conflict was the only factor that affected group work satisfaction and was largely avoided rather than addressed. Interestingly lack of student engagement in group work was not related to overall academic performance and had no impact on their end-of-term exam results. This study highlights high student satisfaction and engagement with online group CBL activities even when collaboration and communication was limited. Achieving higher levels of collaborative learning involving co-regulation of learning and metacognitive processing of learning content may require more specific, formal training in relevant skill sets from an early stage of the veterinary curriculum.

Bovine intracranial neoplasia: A retrospective case series.

This case series describes the clinical and pathological findings of intracranial neoplasms in cattle, a rare entity. Data and archived tissues from 24 intracranial tumors were reviewed and investigated by immunohistochemistry for S100, glial fibrillary acidic protein, synaptophysin, pancytokeratin, vimentin, neuron-specific enolase, oligodendrocyte transcription factor 2, and isocitrate dehydrogenase 1. Ages of affected cattle ranged from 6 months to 14 years (5.7 ± 3.6 years; mean ± SD). Predominant clinical signs were altered mental state, central vestibular dysfunction, and cerebellar incoordination. Twelve gliomas, all high grade, were the most common tumors observed: oligodendrogliomas (n = 6), astrocytomas (n = 4), and undefined gliomas (n = 2). The oligodendrogliomas were located in the brainstem and extended into the ventricles, whereas all astrocytomas were located in the forebrain. Isocitrate dehydrogenase 1 gene mutation as described in humans was not detected. The 5 meningiomas exhibited microcystic, chordoid, atypical, papillary, and anaplastic subtypes. Metastatic carcinomas (n = 4) were the only secondary tumor type present, and these were located at the level of the medulla with infiltration of cranial nerves and in one case leptomeningeal carcinomatosis. In addition, 2 medulloblastomas and 1 choroid plexus carcinoma were diagnosed. Immunohistochemistry for vimentin and pancytokeratin was particularly useful to distinguish meningiomas and choroid plexus carcinoma (positive for vimentin only) from mestastatic carcinomas (positive for cytokeratin only) as all showed a papillary growth pattern. Overall, the morphological features were comparable with other species and the human and canine classifications could be applied.

Dysplastic gangliocytoma of the cerebellum in a cat.

A 2.5-year-old cat presented with progressive ataxia and lethargy. Magnetic resonance imaging (MRI) showed enlargement of the cerebellum and herniation of cerebellar vermis. Postmortem examination confirmed the MRI findings, and histopathology showed numerous large dysplastic neurons populating and displacing the Purkinje cell layer and extending into the molecular and granular layers of the cerebellum. The lesion was diagnosed as dysplastic gangliocytoma of the cerebellum. In humans, this tumor is often associated with Cowden syndrome, a genetic disorder characterized by multiple hamartomas and an increased risk of developing certain neoplasms, known to be linked to a germline mutation of the phosphatase and tensin homolog (PTEN) gene. Reduction in PTEN nuclear and cytoplasmic immunohistochemical labeling of dysplastic neurons in this case suggested a possible PTEN mutation involved in the tumorigenesis. This report provides a detailed pathology description of the tumor and the use of neuronal and PTEN markers which will help guide pathologists presented with this rare condition in the future.

Climbing the Integration Ladder: A Case Study on an Interdisciplinary and Case-Based Approach to Teaching General Pathology, Parasitology and Microbiology in the Veterinary Curriculum.

The School of Veterinary Medicine, University College Dublin, Ireland, restructured the teaching of general pathology, parasitology, and microbiology in third year in 2018 as part of the development of an outcome-based curriculum. A new integrated teaching module was created, called Veterinary Pathobiology, which encompassed the three paraclinical subjects, worth 20 ECTS credits. Subject integration was driven and supported by case-based learning (CBL) activities, and practical classes, which were aimed at facilitating the understanding of basic disease processes, infectious agents, and the application of diagnostic tests. The disciplines maintained their identities within lectures which were aligned by content. The restructuring led to a reduction of contact hours by 20% and of assessment time by 40%. The examinations included integrated questions with an emphasis on the material students had covered in their CBL. Despite positive outcomes, which included equivalent examination scores and positive written feedback by students on teaching and learning, understanding, assessment, relevance, CBL, group work, and generic skills, the average scores for overall student satisfaction dropped dramatically in the second academic year of implementation. This followed the introduction of new regulations by the University relating to student progression, which was capped at "carrying" 10 ECTS credits, thus preventing students that failed the new module from progressing. Other criticisms of the new module by students included too little communication on the changes implemented in its first iteration and a workload perceived to be too heavy. Further restructuring is therefore necessary. This study highlights the process/pitfalls of integration/curricular innovation.

Gremlin 1 depletion in vivo causes severe enteropathy and bone marrow failure.

The intestinal epithelium is perpetually renewed from a stem cell niche in the base of crypts to maintain a healthy bowel mucosa. Exit from this niche and maturation of epithelial cells requires tightly controlled gradients in BMP signalling, progressing from low BMP signalling at the crypt base to high signalling at the luminal surface. The BMP antagonist gremlin 1 (Grem1) is highly expressed by subepithelial myofibroblasts adjacent to the intestinal crypts but its role in regulating the stem cell niche and epithelial renewal in vivo has not been explored. To explore the effects of Grem1 loss in adulthood following normal growth and development, we bred mice (ROSA26CreER-Grem1 flx/flx ) in which Grem1 could be deleted by tamoxifen administration. While Grem1 remained intact, these mice were healthy, grew normally, and reproduced successfully. Following Grem1 depletion, the mice became unwell and were euthanised (at 7-13 days). Post-mortem examination revealed extensive mucosal abnormalities throughout the small and large intestines with failure of epithelial cell replication and maturation, villous atrophy, and features of malabsorption. Bone marrow hypoplasia was also observed with associated early haematopoietic failure. These results demonstrate an essential homeostatic role for gremlin 1 in maintaining normal bowel epithelial function in adulthood, suggesting that abnormalities in gremlin 1 expression can contribute to enteropathies. We also identified a previously unsuspected requirement for gremlin 1 in normal haematopoiesis. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Polyneuropathy in Young Siberian Huskies Caused by Degenerative and Inflammatory Diseases.

Polyneuropathy is defined as the simultaneous dysfunction of several peripheral nerves. In dogs, a number of breeds are predisposed to a variety of immune-mediated and/or degenerative inherited forms of polyneuropathy, with laryngeal paralysis and/or megaesophagus as important clinical features of many of these conditions. This case series describes degenerative and inflammatory polyneuropathies in 7 young Siberian huskies that were categorized based on clinicopathological characteristics as follows: (1) slowly progressive laryngeal paralysis and megaesophagus caused by primary axonal degeneration with large fiber loss (n = 2); (2) slowly progressive polyneuropathy without megaesophagus or laryngeal paralysis caused by primary axonal degeneration with large fiber loss (n = 2); (3) acute inflammatory demyelinating neuropathy causing sensory, motor and autonomic nerve deficits (n = 2); and (4) ganglioradiculitis (sensory neuronopathy; n = 1). Based on the predominantly young age at onset, slow progression, relatedness of affected dogs, and clinical and pathological similarities with inherited neuropathies reported in other dog breeds, a hereditary basis for the degenerative polyneuropathies in Siberian huskies is suspected. However, 5 different mutations in 3 genes known to cause polyneuropathy in other dog breeds (NDRG1, ARHGEF10, or RAB3GAP1) were not detected in the affected Siberian huskies suggesting that more genetic variants remain to be identified. This study highlights the varied underlying lesions of polyneuropathies in young Siberian huskies.

Non-functional thyroid cystadenoma in three boxer dogs.

BACKGROUND: Thyroid neoplasia is a common endocrine neoplasm in dogs. The boxer is one of the reported breeds predisposed to malignant thyroid neoplasia. However, the association between thyroid neoplasia, malignancy and breed should be considered with caution. CASES PRESENTATION: This article describes the presentation, clinical pathological findings, computed tomographic (CT) imaging findings and histopathological features of benign cystic thyroid tumour (cystadenoma) diagnosed in three boxers. These three dogs were presented for investigation of unilateral (n = 2) or bilateral (n = 1) cervical masses with no associated clinical signs of thyroid dysfunction. In each case, post-contrast CT scan identified a large, lateralised, non-invasive, well-defined homogeneous cystic structure with a hyperattenuating contrast-enhancing capsule of suspected thyroid origin displacing the surrounding cervical tissues. Ultrasound-guided fine needle aspiration of the cysts yielded fluid with a high thyroxine concentration in each case. Histopathology was consistent with thyroid cystadenoma in all cases. One dog was concurrently diagnosed with oral melanoma and euthanased. Two dogs underwent surgical excision with one lost to follow-up after 36 months and the other euthanased after 16 months following diagnosis of mast cell tumour. CONCLUSIONS: To the authors' knowledge, this is the first detailed report of non-functional benign thyroid cystadenoma in dogs and provides relevant information about case management for this type of tumour. The presence of a large cystic structure associated with benign non-functional thyroid neoplasia may be a condition to which boxer dogs are predisposed.

Cleavage of the extracellular domain of junctional adhesion molecule-A is associated with resistance to anti-HER2 therapies in breast cancer settings.

BACKGROUND: Junctional adhesion molecule-A (JAM-A) is an adhesion molecule whose overexpression on breast tumor tissue has been associated with aggressive cancer phenotypes, including human epidermal growth factor receptor-2 (HER2)-positive disease. Since JAM-A has been described to regulate HER2 expression in breast cancer cells, we hypothesized that JAM-dependent stabilization of HER2 could participate in resistance to HER2-targeted therapies. METHODS: Using breast cancer cell line models resistant to anti-HER2 drugs, we investigated JAM-A expression and the effect of JAM-A silencing on biochemical/functional parameters. We also tested whether altered JAM-A expression/processing underpinned differences between drug-sensitive and -resistant cells and acted as a biomarker of patients who developed resistance to HER2-targeted therapies. RESULTS: Silencing JAM-A enhanced the anti-proliferative effects of anti-HER2 treatments in trastuzumab- and lapatinib-resistant breast cancer cells and further reduced HER2 protein expression and Akt phosphorylation in drug-treated cells. Increased epidermal growth factor receptor expression observed in drug-resistant models was normalized upon JAM-A silencing. JAM-A was highly expressed in all of a small cohort of HER2-positive patients whose disease recurred following anti-HER2 therapy. High JAM-A expression also correlated with metastatic disease at the time of diagnosis in another patient cohort resistant to trastuzumab therapy. Importantly, cleavage of JAM-A was increased in drug-resistant cell lines in conjunction with increased expression of ADAM-10 and -17 metalloproteases. Pharmacological inhibition or genetic silencing studies suggested a particular role for ADAM-10 in reducing JAM-A cleavage and partially re-sensitizing drug-resistant cells to the anti-proliferative effects of HER2-targeted drugs. Functionally, recombinant cleaved JAM-A enhanced breast cancer cell invasion in vitro and both invasion and proliferation in a semi-in vivo model. Finally, cleaved JAM-A was detectable in the serum of a small cohort of HER2-positive patients and correlated significantly with resistance to HER2-targeted therapy. CONCLUSIONS: Collectively, our data suggest a novel model whereby increased expression and cleavage of JAM-A drive tumorigenic behavior and act as a biomarker and potential therapeutic target for resistance to HER2-targeted therapies.

Sperm-Coating Beta-Defensin 126 Is a Dissociation-Resistant Dimer Produced by Epididymal Epithelium in the Bovine Reproductive Tract.

Beta-defensins are innate immune molecules, often described as antimicrobial peptides because of their bactericidal activity and are now known to have diverse additional functions, including cell signaling, chemoattraction, immunoregulation, and reproduction. In humans and primates, beta-defensin 126 has been shown to regulate the ability of sperm to swim through cervical mucus and to protect sperm from attack by the female immune system during transit toward the oviduct. Bovine beta-defensin 126 (BBD126) is the ortholog of human defensin 126, and computational analysis here revealed significant conservation between BBD126 and other mammalian orthologs at the N-terminus, although extensive sequence differences were detected at the C-terminus, implying possible species-specific roles for this beta-defensin in reproduction. We had previously demonstrated preferential expression of this and related beta-defensin genes in the bovine male reproductive tract, but no studies of bovine beta-defensin proteins have been performed to date. Here, we analyzed BBD126 protein using a monoclonal antibody (a-BBD126) generated against a 14 amino acid peptide sequence from the secreted fragment of BBD126. The specificity of a-BBD126 was validated by testing against the native form of the peptide recovered from bovine caudal epididymal fluid and recombinant BBD126 generated using a prokaryotic expression system. Western blot analysis of the native and recombinant forms showed that BBD126 exists as a dimer that was highly resistant to standard methods of dissociation. Immunohistochemical staining using a-BBD126 demonstrated BBD126 protein expression by epithelial cells of the caudal epididymis and vas deferens from both mature and immature bulls. BBD126 could also be seen (by confocal microscopy) to coat caudal sperm, with staining concentrated on the tail of the sperm cells. This study is the first to demonstrate beta-defensin 126 protein expression in the bovine reproductive tract and on bull sperm. Its dissociation-resistant dimeric structure is likely to have important functional implications for the role of BBD126 in bovine reproduction.

Endoscopic-assisted resection of a pedunculated uterine leiomyoma with maximal tissue preservation in a cow and a mare.

OBJECTIVE: To report successful minimally invasive treatment of a uterine leiomyoma in a cow and a mare. STUDY DESIGN: Clinical report. ANIMAL POPULATION: Limousine cow (n = 1), Thoroughbred mare (n = 1). METHODS: A 10-year-old cow and an 18-year-old mare were presented for difficulties in breeding and infertility, respectively. Examination of the reproductive tract revealed the presence of a large mass attached to the uterine wall via a wide and short peduncle in both cases. The mass expanded into the uterine lumen in the mare and into the abdomen in the cow. Both masses were removed using a minimally invasive endoscopic approach and a vessel-sealing and dividing device. RESULTS: Minimally invasive surgical resection of a subserosal and a submucosal leiomyoma with maximal sparing of uterine tissue resulted in a short convalescence period and apparent return to breeding function in a cow and a mare. Use of a vessel-sealing and dividing device provided excellent hemostasis and decreased tissue handling. CONCLUSION: Leiomyoma with short, wide, and thick peduncles were treated successfully in a cow and a mare with minimally invasive endoscopic approaches aiming at maximal uterine tissue preservation.

First report of Besnoitia bennetti in Irish donkeys: an emerging parasitic disease in Europe.

BACKGROUND: This is the first report of Besnoitia bennetti in donkeys in Ireland. B. bennetti, an apicomplexan protozoan parasite specific to equids, is an emerging pathogen in Europe. This parasite forms chronic intracytoplasmic cysts in cells of the mesenchymal lineage, mainly fibroblasts, in the skin, sclera and mucosa. Clinical signs in affected equine hosts vary from mild to severe debilitating disease. Little is known of the phylogeny, epidemiology or transmission of B. bennetti infection in donkeys, mules or horses. CASE PRESENTATION: Two cases of besnoitiosis in donkeys are presented. Both donkeys were born and raised in theSouthwest of Ireland. The first case was a 2.5-year-old donkey that had a suspect sarcoid removed, while the second case,a 2-year-old donkey, had a biopsy of nodular dermatitis of the muzzle. Diagnosis was made by histopathology and the parasite species, B. bennetti, was confirmed by PCR followed by sequencing and microsatellite analysis. Both donkeys had high antibody titres against Besnoitia spp. Small (0.5 mm) scleral, conjunctival and dermal cysts over the muzzle were subsequently observed in both animals. Treatment with trimethoprim sulfadiazine for 30 days did not lead to clinical resolution. The findings are compared to the cases of besnoitiosis in donkeys reported in the past 10 years throughout Europe. CONCLUSIONS: Besnoitiosis should be considered as a differential diagnosis for chronic skin disease particularly in cases of cutaneous masses, non-pruritic dermatitis, and dermatitis that is not responsive to treatment in donkeys and other equids. Future studies are needed to investigate the prevalence of the disease in Irish donkeys, the spread of the disease and the potential impact on the health and welfare of the donkeys.

Mycobacteriosis in ostriches (Struthio camelus) due to infection with Mycobacterium bovis and Mycobacterium avium complex.

Avian tuberculosis rarely affects ratites compared to other bird species and is typically caused by Mycobacterium avium species. This study describes the pathological and microbiological findings in three adult ostriches with mycobacteriosis, in one of which Mycobacterium bovis was isolated from the lesions. Post mortem examinations on ostriches from two different zoological collections in Ireland revealed multifocal caseous granulomas affecting the spleen and liver in all cases, with additional involvement of intestines in two cases. In one case, granulomas were present within the pharynx, at the thoracic inlet and multifocally on the pleural surface. Acid-fast bacilli were observed in all lesions. Mycobacterium sp. of the M. avium complex was isolated from the intestinal lesions in the two cases with intestinal involvement, and M. bovis sp. oligotype SB0140 was cultured from the liver of the third ostrich. This represents the first reported case of M. bovis infection in an ostrich. Avian tuberculosis due to M. bovis is rare and to date has been reported in only parrots and experimentally inoculated birds. Mycobacterium bovis needs to be considered as a possible cause of tuberculosis in ostriches because the lesions are similar to those observed with M. avium complex infection.

The comparative performance of a custom Canine NanoString® panel on FFPE and snap frozen liver biopsies.

Formalin-Fixed Paraffin Embedded (FFPE) biopsies would provide a critical mass of cases to allow investigation of canine liver disease, however their use is often limited by challenges typically associated with transcriptomic analysis. This study evaluates the capability of NanoString® to measure the expression of a broad panel of genes in FFPE liver samples. RNA was isolated from matched histopathologically normal liver samples using FFPE (n = 6) and snap frozen in liquid nitrogen (n = 6) and measured using a custom NanoString® panel. Out of the 40 targets on the panel, 27 and 23 targets were above threshold for non-diseased snap frozen and FFPE tissue respectively. The binding density and total counts were significantly reduced in the FFPE samples relative to the snap frozen samples (p = 0.005, p = 0.01, respectively), confirming a reduction in sensitivity. The concordance between the snap frozen and FFPE samples was high, with correlations (R) ranging between 0.88 and 0.99 between the paired samples. An additional 14 immune-related targets, undetectable the non-diseased FFPE liver, were above threshold when the technique was applied to a series of diseased samples, further supporting their inclusion on this panel. This use of NanoString® based analysis opens up huge opportunity for retrospective evaluation of gene signatures in larger caseloads through harnessing the capacity of archived FFPE samples This information used alongside clinical and histological data will not only afford a way to explore disease etiopathogenesis, it may also offer insight into sub-types of liver disease in dogs, which cannot be discerned using more traditional diagnostic methods.

Bacterial cholangiohepatitis in a dog.

A 9-year-old female Yorkshire terrier was presented for vomiting and diarrhea. Blood chemistry tests revealed hepatic dysfunction, cholestasis, and inflammation. Liver ultrasonography and liver biopsy were consistent with cholangiohepatitis. Fine-needle aspiration of the gallbladder revealed the presence of bacteria later identified as Clostridium spp. The cholangiohepatitis was successfully treated.

Pathology in Practice.

In collaboration with the American College of Veterinary Pathologists.

Functional Antagonism of Junctional Adhesion Molecule-A (JAM-A), Overexpressed in Breast Ductal Carcinoma In Situ (DCIS), Reduces HER2-Positive Tumor Progression.

Breast ductal carcinoma in situ (DCIS) is clinically challenging, featuring high diagnosis rates and few targeted therapies. Expression/signaling from junctional adhesion molecule-A (JAM-A) has been linked to poor prognosis in invasive breast cancers, but its role in DCIS is unknown. Since progression from DCIS to invasive cancer has been linked with overexpression of the human epidermal growth factor receptor-2 (HER2), and JAM-A regulates HER2 expression, we evaluated JAM-A as a therapeutic target in DCIS. JAM-A expression was immunohistochemically assessed in patient DCIS tissues. A novel JAM-A antagonist (JBS2) was designed and tested alone/in combination with the HER2 kinase inhibitor lapatinib, using SUM-225 cells in vitro and in vivo as validated DCIS models. Murine tumors were proteomically analyzed. JAM-A expression was moderate/high in 96% of DCIS patient tissues, versus 23% of normal adjacent tissues. JBS2 bound to recombinant JAM-A, inhibiting cell viability in SUM-225 cells and a primary DCIS culture in vitro and in a chick embryo xenograft model. JBS2 reduced tumor progression in in vivo models of SUM-225 cells engrafted into mammary fat pads or directly injected into the mammary ducts of NOD-SCID mice. Preliminary proteomic analysis revealed alterations in angiogenic and apoptotic pathways. High JAM-A expression in aggressive DCIS lesions and their sensitivity to treatment by a novel JAM-A antagonist support the viability of testing JAM-A as a novel therapeutic target in DCIS.

Outbreak of acute larval cyathostominosis - A "perfect storm" of inflammation and dysbiosis.

BACKGROUND: Cyathostomins are prevalent and pathogenic intestinal helminths of horses, causing acute and chronic disease, including acute larval cyathostominosis, which has a mortality rate of 50%. Factors determining individual susceptibility to acute larval cyathostominosis are unknown. Investigation of these factors could lead to novel treatment and prevention strategies. OBJECTIVES: To investigate clinicopathological and faecal microbiota changes associated with disease in individual horses in an acute larval cyathostominosis outbreak. STUDY DESIGN: Case series. METHODS: The study population was a herd of 23 mixed breed horses in Ireland. The outbreak occurred in November 2018. Fourteen horses were clinically affected. Clinical status was monitored and recorded. Blood and faecal sampling allowed clinicopathological, faecal 16s rRNA gene sequencing and faecal egg count analyses. RESULTS: Two horses were euthanised, whilst 12 recovered. Common clinical signs included loose faecal consistency, weight loss and pyrexia. Consistent clinicopathological findings were borderline anaemia, leucocytosis, thrombocytosis, hyperfibrinogenaemia, hyperglobulinaemia and a reverse A: G ratio. Decreased alpha-diversity of the faecal microbiota and greater relative abundance of the genus Streptococcus, class Bacilli, order Lactobacillales and family Streptococcaceae, and family Prevotelleceae was found in clinically affected horses compared to their clinically normal cohorts. An increase in obligate fibrolytic bacteria was seen in the clinically normal group compared to the clinical group. Histopathological findings of the colon and caecum revealed a severe necrotising typhlocolitis associated with cyathostomin larvae and bacterial overgrowth in the mucosa of the large intestine. MAIN LIMITATIONS: The study population in this outbreak is small. There are several confounding factors limiting this to a descriptive case series. Faecal microbiota has been shown to reflect the large intestinal microbiota but do not represent changes directly. CONCLUSIONS: These findings suggest that acute larval cyathostominosis is associated with dysbiosis of the gut microbiota as well as the inflammatory stimulus of numerous emerging larvae leading to structural and functional pathology of the large intestine.