Spontaneous hepatocellular and gastric tumours in African clawed frogs ().

Three seven-year-old African clawed frogs () from an animal research facility showed weight loss, coelomic distention and an abnormal swimming gait were euthanised on welfare grounds. A complete necropsy of each animal showed a focal, firm, dark brown to green mass with multifocal haemorrhages in the left liver lobe in two animals and a transmural, firm, beige, multilobulated gastric mass in another animal. Additionally, one of the frogs with the hepatic mass had haemocoeloma.

Virus-Shaped Mesoporous Silica Nanostars to Improve the Transport of Drugs across the Blood-Brain Barrier.

Conditions affecting the brain are the second leading cause of death globally. One of the main challenges for drugs targeting brain diseases is passing the blood-brain barrier (BBB). Here, the effectiveness of mesoporous silica nanostars (MSiNSs) with two different spike lengths to cross an BBB multicellular model was evaluated and compared to spherical nanoparticles (MSiNP).

Canine ovarian epithelial tumours: histopathological and immunohistochemical evaluation with proposed histopathological classification system.

Canine ovarian epithelial tumours (OETs) are currently divided into ovarian adenomas and carcinomas, which are further inconsistently subclassified as papillary or cystic, whereas in human medicine, OETs are subdivided into several subtypes. This study aimed to establish clear morphological features enabling more consistent distinction between benign OETs and ovarian carcinomas (OvCas) as well as defining different histopathological patterns of canine OvCas. Analysis revealed a mitotic count threshold of >2 as a potential criterion for differentiating OvCas from benign OETs.

CD117 expression in canine ovarian tumours.

Canine ovarian cancer poses a significant diagnostic and therapeutic challenge. The heterogeneous nature of ovarian tumours makes accurate histological identification difficult, whilst treatment is limited to surgical excision. The tyrosine kinase receptor CD117 is neo-expressed in many tumours and represents a potential diagnostic and prognostic biomarker and therapeutic target.

Dietary fibre supplementation enhances radiotherapy tumour control and alleviates intestinal radiation toxicity.

Background: Non-toxic approaches to enhance radiotherapy outcomes are beneficial, particularly in ageing populations. Based on preclinical findings showing that high-fibre diets sensitised bladder tumours to irradiation by modifying the gut microbiota, along with clinical evidence of prebiotics enhancing anti-cancer immunity, we hypothesised that dietary fibre and its gut microbiota modification can radiosensitise tumours via secretion of metabolites and/or immunomodulation. We investigated the efficacy of high-fibre diets combined with irradiation in immunoproficient C57BL/6 mice bearing bladder cancer flank allografts.

Palmitoyl transferase ZDHHC20 promotes pancreatic cancer metastasis.

Metastasis is one of the defining features of pancreatic ductal adenocarcinoma (PDAC) that contributes to poor prognosis. In this study, the palmitoyl transferase ZDHHC20 was identified in an in vivo short hairpin RNA (shRNA) screen as critical for metastatic outgrowth, with no effect on proliferation and migration in vitro or primary PDAC growth in mice. This phenotype is abrogated in immunocompromised animals and animals with depleted natural killer (NK) cells, indicating that ZDHHC20 affects the interaction of tumor cells and the innate immune system.

Vitamin D regulates microbiome-dependent cancer immunity.

A role for vitamin D in immune modulation and in cancer has been suggested. In this work, we report that mice with increased availability of vitamin D display greater immune-dependent resistance to transplantable cancers and augmented responses to checkpoint blockade immunotherapies. Similarly, in humans, vitamin D-induced genes correlate with improved responses to immune checkpoint inhibitor treatment as well as with immunity to cancer and increased overall survival.

Blimp-1 and c-Maf regulate immune gene networks to protect against distinct pathways of pathobiont-induced colitis.

Intestinal immune responses to microbes are controlled by the cytokine IL-10 to avoid immune pathology. Here, we use single-cell RNA sequencing of colon lamina propria leukocytes (LPLs) along with RNA-seq and ATAC-seq of purified CD4 T cells to show that the transcription factors Blimp-1 (encoded by Prdm1) and c-Maf co-dominantly regulate Il10 while negatively regulating proinflammatory cytokines in effector T cells. Double-deficient Prdm1MafCd4 mice infected with Helicobacter hepaticus developed severe colitis with an increase in T1/NK/ILC1 effector genes in LPLs, while Prdm1Cd4 and MafCd4 mice exhibited moderate pathology and a less-marked type 1 effector response.

Streptococcus zooepidemicus in dogs: Exploring a canine pathogen through multilocus sequence typing.

Streptococcus equi. subsp. zooepidemicus (S.

Feline ventral abdominal wall angiosarcoma: haemangiosarcoma or lymphangiosarcoma? Clinical and pathological characteristics in nine cases.

Objectives: Angiosarcomas are rare malignant mesenchymal neoplasms of endothelial cell origin with a predilection to the ventral abdominal wall in cats. Larger case series describing this entity are lacking.

Methods: Two referral centre laboratory databases were searched for angiosarcoma of the ventral abdominal wall.

Endothelial AHR activity prevents lung barrier disruption in viral infection.

Disruption of the lung endothelial-epithelial cell barrier following respiratory virus infection causes cell and fluid accumulation in the air spaces and compromises vital gas exchange function. Endothelial dysfunction can exacerbate tissue damage, yet it is unclear whether the lung endothelium promotes host resistance against viral pathogens. Here we show that the environmental sensor aryl hydrocarbon receptor (AHR) is highly active in lung endothelial cells and protects against influenza-induced lung vascular leakage.

Type I interferons drive MAIT cell functions against bacterial pneumonia.

Mucosal-associated invariant T (MAIT) cells are abundant in the lung and contribute to host defense against infections. During bacterial infections, MAIT cell activation has been proposed to require T cell receptor (TCR)-mediated recognition of antigens derived from the riboflavin synthesis pathway presented by the antigen-presenting molecule MR1. MAIT cells can also be activated by cytokines in an MR1-independent manner, yet the contribution of MR1-dependent vs.

Olfactory neuroblastoma in a domestic cat and review of the literature.

Nasal tumors account for less than 10% of all feline neoplasms, with lymphoma, followed by adenocarcinoma, and squamous cell carcinoma, the most commonly reported. Nasal neuroectodermal tumors, including olfactory neuroblastoma (ONB), are scarcely described, and their tumorigenesis is largely unknown. Here we report the cytological, histological, and immunohistochemical features of a feline ONB.

Urinary bladder hemangiosarcoma in a cat treated with partial cystectomy and adjuvant metronomic cyclophosphamide and thalidomide.

Visceral hemangiosarcomas (HSA) are rare in cats and typically associated with aggressive biologic behavior and poor prognosis. A 4-year-old male neutered domestic shorthair cat was presented with a 3-month history of hematuria and stranguria; ultrasonography identified a large bladder mass. Complete excision was achieved by partial cystectomy.

Veterinary Comparative Pathology, a Scientific Tool for a Thriving Planet.

In recent years, Earth has overcome unpredictable challenges [...

Pathology and causes of death in captive meerkats ().

Background: Meerkats () are endemic carnivores of southern Africa and, although currently listed as 'least concern' by the International Union for Conservation of Nature (IUCN) red list, there is evidence of a significant decrease in wild populations mainly attributed to effects of climate change. Little is known about diseases associated with mortality in captive meerkats.

Aim: To characterise macroscopic and microscopic lesions that accounted for the death or euthanasia in a series of captive meerkats.

Lung adenocarcinoma promotion by air pollutants.

A complete understanding of how exposure to environmental substances promotes cancer formation is lacking. More than 70 years ago, tumorigenesis was proposed to occur in a two-step process: an initiating step that induces mutations in healthy cells, followed by a promoter step that triggers cancer development. Here we propose that environmental particulate matter measuring ≤2.

USP7 inactivation suppresses APC-mutant intestinal hyperproliferation and tumor development.

Adenomatous polyposis coli (APC) mutation is the hallmark of colorectal cancer (CRC), resulting in constitutive WNT activation. Despite decades of research, targeting WNT signaling in cancer remains challenging due to its on-target toxicity. We have previously shown that the deubiquitinating enzyme USP7 is a tumor-specific WNT activator in APC-truncated cells by deubiquitinating and stabilizing β-catenin, but its role in gut tumorigenesis is unknown.

Clinical and clinicopathological features and outcomes of cats with suspected dietary induced pancytopenia.

Background: After a strong epidemiological link to diet was established in an outbreak of pancytopenia in cats in spring 2021 in the United Kingdom, 3 dry diets were recalled. Concentrations of the hemato- and myelotoxic mycotoxins T-2, HT-2 and diacetoxyscirpenol (DAS) greater than the European Commission guidance for dry cat foods were detected in the recalled diets.

Objectives: To describe clinical and clinicopathological findings in cats diagnosed with suspected diet induced pancytopenia.

Intrinsic host susceptibility among multiple species to intranasal SARS-CoV-2 identifies diverse virological, biodistribution and pathological outcomes.

SARS-CoV-2 exhibits a diverse host species range with variable outcomes, enabling differential host susceptibility studies to assess suitability for pre-clinical countermeasure and pathogenesis studies. Baseline virological, molecular and pathological outcomes were determined among multiple species-one Old World non-human primate (NHP) species (cynomolgus macaques), two New World NHP species (red-bellied tamarins; common marmosets) and Syrian hamsters-following single-dose, atraumatic intranasal administration of SARS-CoV-2/Victoria-01. After serial sacrifice 2, 10 and 28-days post-infection (dpi), hamsters and cynomolgus macaques displayed differential virus biodistribution across respiratory, gastrointestinal and cardiovascular systems.

Elevated angiotensin-converting enzyme 2 (ACE2) expression in cats with hypertrophic cardiomyopathy.

Angiotensin-converting enzyme 2 (ACE2) is an enzyme within the renin-angiotensin-aldosterone system that plays a role in regulating blood pressure. However, it is also a cellular receptor for infection with SARS coronaviruses. Although most cats develop subclinical or mild disease following infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) acquired from human patients, a previous study has suggested hypertrophic cardiomyopathy (HCM) is a potential risk factor for the development of severe disease in the cat.

Histopathological description of iridophoromas resembling skin nodule syndrome in Siamese fighting fish Betta splendens.

Intensive breeding of the Siamese fighting fish Betta splendens, a species that inhabits marshlands in Thailand and other countries in south-east Asia, was traditionally focused on game fighting because the males are very territorial, but has evolved to become mainly devoted to ornamental purposes. Recently, a preliminarily named 'skin nodule syndrome' (SNS) has been described affecting this fish species in Thailand, with multiple bacterial infections suggested, including 4 species of Mycobacterium spp., although the etiology remains elusive.