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ABSTRACT: Histopathological changes are reported in the livers of cats with congenital portosystemic shunts (CPSS) before and after surgical attenuation. Medical records, portovenograms and liver biopsies from cats treated surgically for CPSS were reviewed. Biopsies were graded for histopathological features characteristic of CPSS. Of 40 cats with CPSS included in the study, all had portal vein hypoplasia and arteriolar hyperplasia at initial surgery, 20 (50 per cent) had hepatocyte swelling with microvesicular vacuolar change, 17 (42.5 per cent) had fibrosis, 12 (30 per cent) had hepatocyte swelling with macrovesicular vacuolar change, 8 (20 per cent) had biliary hyperplasia and 2 (5 per cent) had haemosiderin within Küpffer cells. Cats with macrovesicular vacuolar change were significantly older than cats without (P = 0.001), with median ages of 18.5 months and 8.5 months, respectively. Twenty-five cats had partial attenuation of the CPSS at initial surgery, and 16 of these had follow-up biopsy samples. There were no significant differences in the histopathological features of biopsies before and after partial attenuation. From first to second surgery, there was a significant improvement in intrahepatic vasculature on portovenography both before (P = 0.001) and after (P = 0.039) temporary complete attenuation. Following partial CPSS attenuation, there was no significant change in histopathological features despite an improvement in intrahepatic vasculature on portovenography.
The Veterinary record. 01/2013;
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The Veterinary Journal 03/2012; 191(3):271-2. · 2.24 Impact Factor
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ABSTRACT: Surgical attenuation of a congenital portosystemic shunt (CPSS) results in increased liver mass, development of intrahepatic portal vasculature and improved liver function. Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis. The aim of this study was to investigate the role of VEGF and its receptor in the hepatic response to CPSS surgery. The study included 99 dogs with CPSS treated with either partial or complete suture attenuation. Forty-four dogs with partial attenuation underwent a second surgery for complete attenuation. The expression of VEGF and VEGF receptor 2 (VEGFR2) in biopsy samples of liver was assessed by immunohistochemistry with rabbit anti-human VEGF polyclonal antibody and mouse anti-human VEGFR2 monoclonal antibody. Expression of these molecules was graded. The proportion of samples expressing VEGF was significantly greater in samples from dogs with CPSS compared with control samples (P=0.04) and the proportion of samples expressing VEGFR2 was significantly greater in control samples compared with samples from dogs with CPSS (P=0.04). VEGF labelling grade decreased significantly (P=0.038) and VEGFR2 increased significantly (P=0.046) between first and second surgery. The decrease in VEGF may reflect transient expression, preferential expression of other factors, reperfusion of existing vessels and/or increased angiogenesis before surgery in the form of arterialization and subsequent reduction due to improved portal blood flow. Partial suture attenuation was associated with a degree of 'normalization' of VEGF and VEGFR2 expression when compared with the control samples. Further investigation is needed to provide more information on the hepatic response to CPSS surgery.
Journal of comparative pathology 10/2011; 147(1):55-61. · 1.73 Impact Factor
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ABSTRACT: CD11c serves as a marker for human and murine dendritic cells (DCs) and cells expressing this marker have been shown to have similar morphological and functional characteristics in the canine immune system. The aim of this study was to quantify CD11c(+) cells in the duodenum, ileum and colon of healthy dogs and dogs with inflammatory bowel disease (IBD). Endoscopic biopsies from the duodenum (n=12 cases), ileum (n=8 cases) and colon (n=12 cases) were obtained from dogs diagnosed with IBD. Intestinal tissue from 10 healthy beagle dogs was used as control. Immunofluorescence microscopy was carried out using an anti-canine CD11c monoclonal antibody. Labelled cells were recorded as cells per 120,000 μm(2). The canine chronic enteropathy clinical activity index (CCECAI) was calculated for all dogs with IBD. In addition, sections from all dogs with IBD were evaluated according to the guidelines of the World Small Animal Veterinary Association Gastrointestinal Standardization Group. The number of CD11c(+) cells in the duodenum, ileum and colon of dogs with IBD was significantly reduced compared with controls (P<0.01, P<0.01 and P<0.05, respectively). There was a significant negative correlation between the number of CD11c(+) cells in the colon of dogs with IBD and the CCECAI (P=0.044, r(2)=-0.558). Chronic inflammation in canine IBD appears to involve an imbalance in the intestinal DC population. Future studies will determine whether reduced expression of CD11c could be a useful marker for the diagnosis and monitoring of canine IBD.
Journal of comparative pathology 05/2011; 145(4):359-66. · 1.73 Impact Factor
