Poor Agreement Between Imaging and Histologic and Colonoscopy Findings in Pediatric Patients.

BACKGROUND: Computed tomography scans (CTs), more recently magnetic resonance imaging, are often used to assess the gastrointestinal tract in patients complaining of abdominal pain. We aim to determine the strength of agreement among abdominal imaging, endoscopic, and histologic findings. METHODS: Retrospective chart review of pediatric patients who underwent colonoscopy between January 1, 2012, and December 31, 2014, at Women and Children's Hospital of Buffalo. Patients who had abdominal and pelvic CTs or magnetic resonance imaging within 30 days before or after a colonoscopy were included. RESULTS: One hundred two patients were included: mean age 12.7 ±â€Š3.8 years, 66% girls. A total of 109 imaging studies were performed. Overall 61% of imaging studies were abnormal. The most frequent intestinal radiological findings were colonic wall thickening (CWT) (55%) and colonic wall enhancement (CWH) (24%). Free fluid (20%) and fat stranding (18%) were the most common extra-intestinal findings. Imaging studies agreed with histology in 81% and with colonoscopy in 75% with a moderate strength of agreement (k: 0.59 and 0.466, respectively). CWT agreed with histology in 74% with a moderate strength of agreement (k: 0.47). History of weight loss (OR 5.35, P = 0.041), chronic diarrhea (OR 4.22, P = 0.014), a positive lactoferrin (OR 7.00, P = 0.011), and presence of CWT on imaging study (OR 5.20, P = 0.001) were predictive of having abnormal histology. CONCLUSIONS: The strength of agreement among imaging, endoscopic, and histologic findings was suboptimal. Colonoscopy and imaging are both likely to be necessary in patients with suspected inflammatory bowel disease. Although colonoscopy may be superior in diagnosis of colitis, imaging may provide more information regarding small bowel disease.

Pathogenesis of nonalcoholic steatohepatitis.

Nonalcoholic steatohepatitis (NASH) is a severe form of nonalcoholic fatty liver disease and a risk factor for cirrhosis and hepatocellular carcinoma. The pathological features of NASH include steatosis, hepatocyte injury, inflammation, and various degrees of fibrosis. Steatosis reflects disordered lipid metabolism. Insulin resistance and excessive fatty acid influx to the liver are two important contributing factors. Steatosis is also likely associated with lipotoxicity and cellular stresses such as oxidative stress and endoplasmic reticulum stress, which result in hepatocyte injury. Inflammation and fibrosis are frequently triggered by various signals such as proinflammatory cytokines and chemokines, released by injuried hepatocytes and activated Kupffer cells. Although much progress has been made, the pathogenesis of NASH is not fully elucidated. The purpose of this review is to discuss the current understanding of NASH pathogenesis, mainly focusing on factors contributing to steatosis, hepatocyte injury, inflammation, and fibrosis.

Upregulation of non-canonical Wnt ligands and oxidative glucose metabolism in NASH induced by methionine-choline deficient diet.

Wnt ligands regulate metabolic pathways, and dysregulation of Wnt signaling contributes to chronic inflammatory disease. A knowledge gap exists concerning the role of aberrant Wnt signaling in non-alcoholic steatohepatitis (NASH), which exhibits metabolic syndrome and inflammation. Using a mouse model of methionine-choline deficient diet (MCDD)-induced NASH, we investigated the Wnt signaling pathways in relation to hepatic glucose oxidation. Mice fed the MCD diet for 6 weeks developed prominent NASH marked by macrovesicular steatosis, inflammation and lipid peroxidation. qPCR analysis reveals differential hepatic expression of canonical and non-canonical Wnt ligands. While expression of Wnt3a was decreased in NASH vs chow diet control, expression of Wnt5a and Wnt11 were increased 3 fold and 15 fold, respectively. Consistent with activation of non-canonical Wnt signaling, expression of the alternative Wnt receptor ROR2 was increased 5 fold with no change in LRP6 expression. Activities of the metabolic enzymes glucokinase, phosphoglucoisomerase, glyceraldehyde-3-phosphate dehydrogenase, pyruvate kinase, and pyruvate dehydrogenase were all elevated by MCDD. NASH-driven glucose oxidation was accompanied by a 6-fold increase in lactate dehydrogenase (LDH)-B with no change in LDH-A. In addition, glucose-6-phosphate dehydrogenase, the regulatory and NADPH-producing enzyme of the pentose phosphate pathway, was elevated in NASH. These data support a role of accelerated glucose oxidation in the development of NASH, which may be driven by non-canonical Wnt signaling.