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A 7‐month‐old, spayed, female, mixed breed dog was referred for a 3‐day duration of elevated liver enzymes, azotaemia, anorexia and lethargy following ovariohysterectomy. Bloodwork showed non‐regenerative anaemia, inflammatory leukogram, moderate thrombocytopenia, severe azotaemia, severe mixed hepatopathy, hyperbilirubinemia and hypoalbuminemia. Point‐of‐care ultrasound identified free fluid and a heterogeneous mass in the mid‐ventral abdomen. Septic peritonitis was confirmed on cytology, and abdominal exploratory with left medial liver lobectomy was performed. Histopathology identified submassive hepatic necrosis and bridging fibrosis with biliary reaction, confirming a liver lobe torsion. The dog recovered perioperatively, but remained hospitalised to receive dialysis for severe renal dysfunction. The dog was transitioned to outpatient dialysis for several treatments. Unfortunately, kidney function continued to decline after dialysis was discontinued, and humane euthanasia was performed approximately 2 months postoperatively. To the authors' knowledge, this is the first reported case of liver lobe torsion following routine ovariohysterectomy in a dog. [ABSTRACT FROM AUTHOR]

Currently, intraoperative tumour margin imaging is not routinely utilized in veterinary medicine. Optical coherence tomography (OCT) allows for real‐time assessment of tissue morphology of 1–2 mm depth. The aims of this study were (1) to compare the histologic and OCT features of excised canine skin and subcutaneous specimens, and (2) to determine the diagnostic accuracy of OCT for surgical margin evaluation. The authors hypothesized that OCT imaging would correlate well with histopathology and that OCT would be sensitive for detection of incomplete margins. Eighty dogs were prospectively enrolled. Tumours were excised, and the surgical margins were imaged using a spectral domain OCT system. The tumour type and completeness of excision were determined by histopathology. Nine blinded observers received training in OCT image interpretation and were then given a set of OCT images and videos. The observers assigned each image/video a grade from 1 (no tumour) to 4 (tumour) and the results were compared to histopathology. The overall median sensitivity and specificity of OCT imaging for detection of incomplete margins were 86.7% and 84.6%, respectively. A potential limitation is that observers had varied experience with OCT image interpretation, ranging from no prior experience to participating in a previous OCT project. OCT is sensitive for detection of incomplete margins and could be a promising real‐time surgical margin imaging modality. Further study is needed to evaluate intraoperative applications of OCT and its impact on tumour recurrence and long‐term outcome. [ABSTRACT FROM AUTHOR]

Viral signaling through retinoic acid-inducible gene-I (RIG-I) and its adaptor protein, IFN promoter-stimulator 1 (IPS-1), activates IFN regulatory factor-3 (IRF-3) and the host lFN-α/β response that limits virus infection. The hepatitis C virus (HCV) NS3/4A protease cleaves IPS-1 to block RIG-I signaling, but how this regulation controls the host response to HCV is not known. Moreover, endogenous IPS-1 cleavage has not been demonstrated in the context of HCV infection in vitro or in vivo. Here, we show that HCV infection transiently induces RIG-I- and IPS-1-dependent IRF-3 activation. This host response limits HCV production and constrains cellular permissiveness to infection. However, HCV disrupts this response early in infection by N53/4A cleavage of IPS-1 at C508, releasing IPS-1 from the mitochondrial membrane. Cleavage results in subcellular redistribution of IPS-1 and loss of interaction with RIG-I, thereby preventing downstream activation of IRF-3 and IFN-β induction. Liver tissues from chronically infected patients similarly demonstrate subcellular redistribution of IPS-1 in infected hepatocytes and IPS-1 cleavage associated with a lack of ISG15 expression and conjugation of target proteins in vivo. Importantly, small-molecule inhibitors of NS3/4A prevent cleavage and restore RIG-I signaling of IFN-β induction. Our results suggest a dynamic model in which early activation of lRF-3 and induction of antiviral genes are reversed by IPS-1 proteolysis and abrogation of RIG-I signaling as N53/4A accumulates in newly infected cells. HCV protease inhibitors effectively prevent IPS-1 proteolysis, suggesting they may be capable of restoring this innate host response in clinical practice. [ABSTRACT FROM AUTHOR]

The article presents information on a research study that was conducted to identify factors that influence the regulation of interferon production and innate antiviral immunity through translational control of interferon regulatory factor (IRF)-7. The study also demonstrates the importance of translational control mechanisms in regulation of the host response to viral infection.