Chronic hepatitis: a retrospective study in 34 dogs.

The aims of this study were to characterize the histological changes observed in 34 accessioned cases of canine chronic hepatitis and to correlate these changes with the clinical pathological data. Cases of chronic hepatitis were subdivided into 6 categories: chronic active hepatitis (10/34), chronic persistent hepatitis (7/32), chronic cholestatic hepatitis (6/34), fibrosing hepatitis with cirrhosis (3/34), chronic cholangiohepatitis (3/34), and miscellaneous secondary hepatitis (5/34). Iron accumulation was a consistent finding in all livers examined. Although all cases of chronic hepatitis had elevated liver enzymes, no correlation was detected between biochemical parameters and the severity of morphologic changes. Similarly, no correlation was detected between rhodanine staining for copper and morphologic or biochemical indicators of cholestasis. However, presence of copper correlated well with reticulo-fibrosis (r = 0.8) and bile duct hyperplasia, suggesting that changes in the hemodynamics of the hepatic acini due to fibrosis could influence storage of copper.     

Derivation of Canine Induced Pluripotent Stem Cells

Dogs and humans have many inherited genetic diseases in common and conditions that are increasingly prevalent in humans also occur naturally in dogs. The use of dogs for the experimental and clinical testing of stem cell and regenerative medicine products would benefit canine health and welfare and provide relevant animal models for the translation of therapies to the human field. Induced pluripotent stem cells (iPSCs) have the capacity to turn into all cells of the body and therefore have the potential to provide cells for therapeutic use and for disease modelling. The objective of this study was to derive and characterize iPSCs from karyotypically abnormal adult canine cells. Aneuploid adipose‐derived mesenchymal stromal cells (AdMSCs) from an adult female Weimeraner were re‐programmed into iPSCs via overexpression of four human pluripotency factors (Oct 4, Sox2, Klf4 and c‐myc) using retroviral vectors. The iPSCs showed similarity to human ESCs with regard to morphology, pluripotency marker expression and the ability to differentiate into derivatives of all three germ layers in vitro (endoderm, ectoderm and mesoderm). The iPSCs also demonstrated silencing of the viral transgenes and re‐activation of the silent X chromosome, suggesting full reprogramming had occurred. The levels of aneuploidy observed in the AdMSCs were maintained in the iPSCs. This finding demonstrates the potential for generating canine induced pluripotent stem cells for use as disease models in addition to regenerative medicine and pharmaceutical testing.