Biology subjects

Ambrosini, Y.

Publications and source records attributed to Ambrosini, Y..

2 recordsLinked to original sources

bioRxiv2024

Enterohemorrhagic Escherichia coli (EHEC) Disrupts Intestinal Barrier Integrity in Translational Canine Stem Cell-Derived Monolayers

This study addresses the gap in translatable in vitro models for investigating Enterohemorrhagic E. coli (EHEC) infections, particularly relevant to both canine and human health. EHEC is known to induce acute colitis in dogs, leading to symptoms like hemorrhagic diarrhea and hemolytic uremic syndrome, similar to those observed in humans. However, understanding the pathophysiology and developing treatment strategies have been challenging due to the lack of effective models that replicate the clinical disease caused by EHEC in both species. Our approach involved the development of colonoid-derived monolayers using intestinal tissues from healthy, client-owned dogs. These monolayers were exposed to EHEC and the impact of EHEC was assessed through several techniques, including trans-epithelial electrical resistance (TEER) measurement, immunofluorescence staining for junction proteins and mucus, and scanning electron microscopy for morphological analysis. Modified culture with saline, which was intended to prevent bacterial overgrowth, maintained barrier integrity and cell differentiation. EHEC infection led to significant decreases in TEER and ZO-1 expression, but not in E- cadherin levels or mucus production. Additionally, EHEC elicited a notable increase in TNF- production, highlighting its distinct impact on canine intestinal epithelial cells compared to non-pathogenic E. coli. These findings closely replicate in vivo observations in dogs and humans with EHEC enteropathy, validating the canine colonoid-derived monolayer system as a translational model to study host- pathogen interactions in EHEC and potentially other clinically significant enteric pathogens.

microbiology↗

bioRxiv2018

Retrospective Evaluation of Cyclosporine in the Treatment of Chronic Hepatitis in Dogs: 2010-2017

BackgroundIdiopathic chronic hepatitis (CH) in dogs is a prevalent hepatic disorder. The etiology is poorly understood; however, there is evidence to support an immune-mediated pathogenesis. No literature exists investigating the efficacy of cyclosporine (CsA) therapy for CH in dogs.\n\nObjectivesTo retrospectively evaluate the efficacy and adverse side effects of CsA in the treatment of CH in dogs, and to identify factors that impact response to CsA therapy.\n\nAnimals48 client-owned dogs diagnosed with CH treated with CsA for at least 2 weeks.\n\nMethodsRetrospective review of medical records between the years 2010-2017.\n\nResultsTwenty-two breeds of dogs were included of which 54% were spayed females, 42% neutered males and 4% intact males. Median age was 8.5 years (range, 0.7-14 years). Complete remission (normalization of alanine aminotransferase [ALT]) in response to CsA was attained in 79% of dogs (38/48). Median dose of CsA at the time of remission was 7.9 mg/kg/day (range, 2.5-12.7mg/kg/day) and median time to remission was 2.5 months (range, 0.75-18 months). None of the factors evaluated including clinical score, presence of ascites, hypoalbuminemia, hyperbilirubinemia, prolonged coagulation times, dose, or duration of therapy influenced remission. Common side effects were gastrointestinal signs in 38% (18/48) and gingival hyperplasia in 25% (12/48) of dogs.\n\nConclusion and Clinical ImportanceCsA proved to be a tolerated and effective medication in attaining remission in dogs with idiopathic CH based on normalization of serum ALT. None of the evaluated factors were shown to negatively impact response to CsA or remission of disease.

immunology↗