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Tubular epithelial injury represents an underestimated but important cause of renal dysfunction in patients with cholestasis and advanced liver disease, but the underlying mechanisms are unclear. To address the hypothesis that accumulation and excessive alternative urinary elimination of potentially toxic bile acids (BAs) may contribute to kidney injury in cholestasis, we established a mouse model for detailed in vivo time course as well as treatment studies. Three-day common bile duct ligation (CBDL) induced renal tubular epithelial injury predominantly at the level of aquaporin 2-positive collecting ducts with tubular epithelial and basement membrane defects. This was followed by progressive interstitial nephritis and tubulointerstitial renal fibrosis in 3-, 6-, and 8-week CBDL mice. Farnesoid X receptor knockout mice (with a hydrophilic BA pool) were completely protected from CBDL-induced renal fibrosis. Prefeeding of hydrophilic norursodeoxycholic acid inhibited renal tubular epithelial injury in CBDL mice. In addition, we provide evidence for renal tubular injury in cholestatic patients with cholemic nephropathy. Conclusion: We characterized a novel in vivo model for cholemic nephropathy, which offers new perspectives to study the complex pathophysiology of this condition. Our findings suggest that urinary-excreted toxic BAs represent a pivotal trigger for renal tubular epithelial injury leading to cholemic nephropathy in CBDL mice. (HEPATOLOGY 2013;58:2056-2069 A cute kidney injury (AKI) is a common complication in patients with end-stage liver disease and represents a high-risk situation.1 Because of the fact that hepatorenal syndrome (HRS), an important and principally reversible cause of renal failure in patients with liver cirrhosis, may be difficult to differentiate from other causes of AKI in clinical practice, a revised clinical classification has been proposed. 2 Interestingly, recent studies revealed a high proportion of structural abnormalities, including vascular and

Summary Primary sclerosing cholangitis (PSC) is a chronic cholangiopathy characterized by biliary fibrosis, development of cholestasis and end stage liver disease, high risk of malignancy, and frequent need for liver transplantation. The poor understanding of its pathogenesis is also reflected in the lack of effective medical treatment. Well-characterized animal models are utterly needed to develop novel pathogenetic concepts and study new treatment strategies. Currently there is no consensus on how to evaluate and characterize potential PSC models, which makes direct comparison of experimental results and effective exchange of study material between research groups difficult. The International Primary Sclerosing Cholangitis Study Group (IPSCSG) has therefore summarized these key issues in a position paper proposing standard requirements for the study of animal models of PSC.

BACKGROUND: Blood vessel invasion has been associated with poor outcome in colorectal cancer (CRC), whereas the prognostic impact of lymphatic invasion is less clear. The authors of this report evaluated venous and lymphatic invasion as potential prognostic indicators in patients with CRC focusing on lymph node-negative patients and compared routine and review pathology diagnoses. METHODS: In total, 381 tumors from randomly selected patients were retrospectively reviewed. The presence of vascular invasion was related to disease-free and cancer-specific survival using the Kaplan-Meier method. For multivariable analysis, Cox proportional hazards regression models were performed. RESULTS: Lymphatic invasion and venous invasion were observed in 126 patients (33%) and 87 patients (23%), respectively, and were associated significantly with tumor classification, lymph node status, American Joint Committee on Cancer/International Union Against Cancer (AJCC/UICC) disease stage, tumor differentiation, pattern of invasion, and extent of tumor budding. The detection of vascular invasion was related to the number of examined tissue blocks. Venous and lymphatic invasion proved to be significant prognostic variables in univariable and multivariable analyses. Extramural vascular involvement was of particular significance. When the analysis was restricted to patients with (AJCC/UICC) stage II disease, venous invasion, but not lymphatic invasion, was identified as an independent prognostic variable. Review pathology diagnoses differed significantly from routine diagnoses with respect to prognostic impact. CONCLUSIONS: Venous and lymphatic invasion proved to be significant prognostic variables in patients with CRC. The detection of vascular invasion and, consequently, risk stratification of affected patients were related to the quality of pathology workup, ie, the number of examined tissue blocks. Observed differences between review and routine pathology diagnoses illustrated the need for high-quality pathology reporting and also for standardized quality control. Cancer 2012;118:628-

Mucin glycoprotein expression can be altered during the carcinogenic process. The impact on the prognosis of patients with colorectal cancer (CRC) is controversial. We analyzed tumors from 381 patients for MUC1, MUC2, MUC5AC, and MUC6 expression by immunohistochemical staining, using tissue microarrays. Progression-free and cancer-specific survival were determined using the Kaplan-Meier method. Expression of intestinal mucin MUC2 was lost in 85 (23 %) CRCs, and patients with MUC6-negative tumors showed shorter progression-free survival (PFS, p = 0.043). Gastric mucins MUC5AC and MUC6 showed high (>50 %) aberrant expression in 28 (8 %) and 9 (2 %) cases, respectively. High expression of MUC5AC was associated with longer PFS (p = 0.055). High expression of MUC6 was associated with 100 % PFS (p = 0.024) and longer cancer-specific survival (CSS, p = 0.043). MUC1 was expressed in 238 (64 %) tumors and had no impact on outcome. When analysis was restricted to stages II and III, loss of MUC2 was associated with adverse outcome. Overexpression of both MUC5AC and MUC6 significantly predicted favorable PFS and CSS. In conclusion, loss of MUC2 expression proved to be a predictor of adverse outcome, while the gain of aberrant expression of MUC5AC and particularly of MUC6 was associated with favorable outcome in CRC, notably in intermediate stages II and III.

Primary sclerosing cholangitis (PSC) represents a chronic cholestatic liver disease with fibroobliterative sclerosis of intra- and/or extrahepatic bile ducts, eventually leading to biliary cirrhosis.The association with human leukocyte antigen (HLA) and non-HLA haplotypes and the presence of autoantibodies in sera of PSC patients support a crucial role for immune-mediated mechanisms in the initiation and progression of PSC. The strong clinical association between PSC and inflammatory bowel diseases led to intriguing pathogenetic concepts, in which the inflamed gut with translocation of bacterial products and homing of gut-primed memory T lymphocytes via aberrantly expressed adhesion molecules plays a fundamental role. Genetically or chemically modified bile composition was shown to induce sclerosing cholangitis and liver fibrosis in a number of animal models ("toxic bile concept"). The potential role of vascular injury with ischemia of bile duct epithelium cells in the development of sclerosing cholangitis is supported by animal models of endothelial cell injury showing close morphological similarities with human PSC.

In colorectal cancer, the presence and extent of eosinophil granulocyte infiltration may render important prognostic information. However, it remains unclear whether an increasing number of eosinophils might simply be linked to the overall inflammatory cell reaction or represent a self-contained, antitumoral mechanism that needs to be documented and promoted therapeutically. Peri-and intratumoral eosinophil counts were retrospectively assessed in 381 primary colorectal cancers from randomly selected patients. Tumors were diagnosed in American Joint Committee on Cancer (AJCC)/Union Internationale Contre le Cancer (UICC) stage I in 21%, stage II in 32%, stage III in 33%, and stage IV in 14%. Presence and extent of eosinophils was related to various histopathological parameters as well as patients' outcome. Overall, peri-and intratumoral eosinophils were observed in 86 and 75% cancer specimens. The peritumoral eosinophil count correlated strongly with the intratumoral eosinophil count (R ¼ 0.69; Po0.001) and with the intensity of the overall inflammatory cell reaction (R ¼ 0.318; Po0.001). Both increasing peri-and intratumoral eosinophil counts were significantly associated with lower T and N classification, better tumor differentiation, absence of vascular invasion, as well as improved progression-free and cancer-specific survival. However, only peritumoral eosinophils, but not intratumoral, were an independent prognosticator of favorable progression-free (hazard ratio 0.75; 95% confidence interval 0.58-0.98; P ¼ 0.04) and cancer-specific survival (hazard ratio 0.7; 95% confidence interval 0.52-0.93; P ¼ 0.01)-independent of the intensity of overall inflammatory cell reaction. This was also found for patients with AJCC/ UICC stage II disease, wherein the presence of peritumoral eosinophils was significantly associated with favorable outcome. In conclusion, the number of peritumoral eosinophils had a significant favorable impact on prognosis of colorectal cancer patients independent of the overall tumor-associated inflammatory response. Evaluation of peritumoral eosinophils represents a promising readily assessable tool and should therefore routinely be commented on in the pathology report.

Tumor size proved to be an independent prognostic parameter for patients with colorectal cancer. Optimal cut-off values vary among different parts of the large bowel. Whereas prognostic significance is strong within the colon, it appears to be of minor value within the rectum.