GATA4 and GATA6 loss-of-expression is associated with extinction of the classical programme and poor outcome in pancreatic ductal adenocarcinoma.

OBJECTIVE: GATA6 is a key regulator of the classical phenotype in pancreatic ductal adenocarcinoma (PDAC). Low GATA6 expression associates with poor patient outcome. GATA4 is the second most expressed GATA factor in the pancreas. We assessed whether, and how, GATA4 contributes to PDAC phenotype and analysed the association of expression with outcome and response to chemotherapy. DESIGN: We analysed PDAC transcriptomic data, stratifying cases according to GATA4 and GATA6 expression and identified differentially expressed genes and pathways. The genome-wide distribution of GATA4 was assessed, as well as the effects of GATA4 knockdown. A multicentre tissue microarray study to assess GATA4 and GATA6 expression in samples (n=745) from patients with resectable was performed. GATA4 and GATA6 levels were dichotomised into high/low categorical variables; association with outcome was assessed using univariable and multivariable Cox regression models. RESULTS: GATA4 messenger RNA is enriched in classical, compared with basal-like tumours. We classified samples in 4 groups as high/low for GATA4 and GATA6. Reduced expression of GATA4 had a minor transcriptional impact but low expression of GATA4 enhanced the effects of GATA6 low expression. GATA4 and GATA6 display a partially overlapping genome-wide distribution, mainly at promoters. Reduced expression of both proteins in tumours was associated with the worst patient survival. GATA4 and GATA6 expression significantly decreased in metastases and negatively correlated with basal markers. CONCLUSIONS: GATA4 and GATA6 cooperate to maintain the classical phenotype. Our findings provide compelling rationale to assess their expression as biomarkers of poor prognosis and therapeutic response.

Renal allograft rejection, lymphocyte infiltration, and de novo donor-specific antibodies in a novel model of non-adherence to immunosuppressive therapy.

BACKGROUND: Non-adherence has been associated with reduced graft survival. The aim of this study was to investigate the immunological mechanisms underlying chronic renal allograft rejection using a model of non-adherence to immunosuppressive therapy. We used a MHC (major histocompatibility complex) -mismatched rat model of renal transplantation (Brown Norway to Lewis), in which rats received daily oral cyclosporine A. In analogy to non-adherence to therapy, one group received cyclosporine A on alternating days only. Rejection was histologically graded according to the Banff classification. We quantified fibrosis by trichrome staining and intra-graft infiltration of T cells, B cells, and monocytes/macrophages by immunohistochemistry. The distribution of B lymphocytes was assessed using immunofluorescence microscopy. Intra-graft chemokine, chemokine receptor, BAFF (B cell activating factor belonging to the TNF family), and immunoglobulin G transcription levels were analysed by RT-PCR. Finally, we evaluated donor-specific antibodies (DSA) and complement-dependent cytotoxicity using flow cytometry. RESULTS: After 28 days, cellular rejection occurred during non-adherence in 5/6 animals, mixed with humoral rejection in 3/6 animals. After non-adherence, the number of T lymphocytes were elevated compared to daily immunosuppression. Monocyte numbers declined over time. Accordingly, lymphocyte chemokine transcription was significantly increased in the graft, as was the transcription of BAFF, BAFF receptor, and Immunoglobulin G. Donor specific antibodies were elevated in non-adherence, but did not induce complement-dependent cytotoxicity. CONCLUSION: Cellular and humoral rejection, lymphocyte infiltration, and de novo DSA are induced in this model of non-adherence.

Anthocyanins Prevent Colorectal Cancer Development in a Mouse Model.

BACKGROUND: Colorectal cancer is the main leading cause of cancer-related deaths worldwide. Present data suggest that plant-derived anthocyanins have anti-inflammatory and chemopreventive properties. This study was aimed at evaluating the effect of an anthocyanin-rich extract from bilberries on colorectal tumour development and growth in the administration of azoxymethan (AOM)/dextran sodium sulfate (DSS) mouse model. METHODS: Colonic carcinogenesis was induced by AOM and DSS 3 or 5%, respectively, in 50 female Balb/c mice. Mice received either normal food (controls) or a diet containing either 10 or 1% anthocyanin-rich bilberry extract. Colonoscopy took place at week 4 and 9 after initiation of carcinogenesis. After termination at week 9, colon samples were analysed macroscopically and microscopically. RESULTS: Mice receiving 10% anthocyanins showed significantly (p < 0.004) less reduced colon length (12.1 cm [8.5-14.4 cm]) as compared to controls (11.2 cm [9.8-12.3]) indicating less inflammation. Mice fed with 10% anthocyanin-rich extract revealed significantly less mean tumour numbers (n = 1.2) compared to control (n = 14) and anthocyanin 1% treated mice (n = 10.6, p < 0.001). CONCLUSION: Anthocyanins prevented the formation and growth of colorectal cancer in AOM/DSS-treated Balb/c mice. Further studies should investigate the mechanisms of how anthocyanins influence the development of colorectal cancer.

ALPPS (associating liver partition and portal vein ligation for staged hepatectomy) does not affect proliferation, apoptosis, or angiogenesis as compared to standard liver resection for colorectal liver metastases.

BACKGROUND: ALPPS (associating liver partition and portal vein ligation for staged hepatectomy) is a novel two-stage strategy to induce rapid hypertrophy of the future liver remnant (FLR) when patients are in danger of postoperative liver failure due to insufficient FLR. However, the effects of ALPPS on colorectal liver metastases (CRLM) are not clear so far. The aim of our study was to determine whether ALPPS induces proliferation, apoptosis, or vascularization compared to standard (one-stage) liver resection. METHODS: Six patients who underwent ALPPS were matched with 12 patients undergoing standard liver resection regarding characteristics of the metastases (size, number), time of appearance (syn-/metachronous), preoperative chemotherapy, primary tumor (localization, TNM stage, grading), and patient variables (gender, age). The largest resected metastasis was used for the analyses. Tissue was stained for tumor cell proliferation (Ki67), apoptosis (TUNEL, caspase-3), vascularization (CD31), and pericytes (αSMA). RESULTS: Vascularization (CD31; p = 0.149), proliferation (Mib-1; p = 0.244), and αSMA expression (p = 0.205) did not significantly differ between the two groups, although a trend towards less proliferation and αSMA expression was observed in patients undergoing ALPPS. Concerning apoptosis, caspase-3 staining showed significantly fewer apoptotic cells upon ALPPS (p < 0.0001), but this was not confirmed by TUNEL staining (p = 0.7344). CONCLUSIONS: ALPPS does not induce proliferation, apoptosis, or vascularization of CRLM when compared to standard liver resection.

Tumor-infiltrating, interleukin-33-producing effector-memory CD8(+) T cells in resected hepatocellular carcinoma prolong patient survival.

UNLABELLED: Interleukin-33 (IL-33), a cytokine with pleiotropic functions, is elevated in serum of patients with hepatocellular carcinoma (HCC). This study investigated the effects of local IL-33 expression in resected HCC on patient survival and on the immunological and molecular tumor microenvironment. Tissue of resected HCCs was stained for hematoxylin and eosin, Masson trichrome, alpha-smooth muscle actin, IL-33, CD8, and IL-13 and analyzed by flow cytometry. Besides histomorphologic evaluation, the immunohistochemical stainings were analyzed for the respective cell numbers separately for tumor area, infiltrative margin, and distant liver stroma. These findings were correlated with clinical data and patient outcome. Further, gene expression of different HCC risk groups was compared using microarrays. In multivariable analysis, infiltration of HCCs by IL-33(+) cells (P = 0.032) and CD8(+) cells (P = 0.014) independently was associated with prolonged patient survival. Flow cytometry demonstrated that cytotoxically active subpopulations of CD8(+) cells, in particular CD8(+) CD62L(-) KLRG1(+) CD107a(+) effector-memory cells, are the main producers of IL-33 in these HCC patients. Using infiltration by IL-33(+) and CD8(+) cells as two separate factors, an HCC immune score was designed and evaluated that stratified patient survival (P = 0.0004). This HCC immune score identified high- and low-risk patients who differ in gene expression profiles (P < 0.001). CONCLUSION: Infiltration of HCCs by IL-33(+) and CD8(+) cells is independently associated with prolonged patient survival. We suggest that this is due to an induction of highly effective, cytotoxically active CD8(+) CD62L(-) KLRG1(+) CD107a(+) effector-memory cells producing IL-33. Based on these two independent factors, we established an HCC immune score that provides risk stratification for HCC patients and can be used in the clinical setting.

IL-13 orchestrates resolution of chronic intestinal inflammation via phosphorylation of glycogen synthase kinase-3ß.

Spontaneous amelioration of inflammation (often accompanied by fibrosis) is a well-known, but poorly understood, outcome of many chronic inflammatory processes. We studied this phenomenon in a chronic trinitrobenzene sulfonic acid-induced colitis model, an experimental colitis in mice that we showed to ultimately undergo spontaneous resolution, despite continued trinitrobenzene sulfonic acid stimulation. Analysis of the mechanism of this resolution revealed that it was critically dependent on IL-13 activation of STAT6, followed by phosphorylation (inactivation) of glycogen synthase kinase-3ß, at least in part via STAT6 induction of p38 MAPK. Such glycogen synthase kinase-3ß inactivation causes changes in CREB and p65 DNA-binding activity that favors decreased proinflammatory IL-17 production and increased anti-inflammatory IL-10 production. Thus, in this case, IL-13 acts as a molecular switch that leads to resolution of inflammation.

Immune Architecture of Colorectal Lung Metastases and Implications for Patient Survival.

BACKGROUND: Pulmonary metastases occur in 10-20% of patients with colorectal cancer and significantly influence long-term survival. In this study, the immunological architecture of colorectal lung in comparison to liver metastases and its impact on patient survival were examined. METHODS: Specimens of patients with colorectal lung and liver metastases were stained for HE, CD4, CD8, CD20, CD68 and CD45RO. Besides histomorphological evaluation, immunohistochemical stainings were analyzed for the respective cell numbers separately for tumor area, infiltrative margin and distant lung or liver stroma. These findings were correlated with clinical data and patient outcome. RESULTS: In colorectal lung (n = 69) in comparison to liver (n = 222) metastases, the immunological focus is located in the tumor region. A high CD4+ cell infiltration of this area is associated with prolonged survival of patients after resection of colorectal lung metastases [103 ± 33 (high) vs. 37 ± 6 months (low); p = 0.0246]. Patients who were treated with preoperative chemotherapy did not show differences in immune infiltrates compared to chemotherapy-naïve patients. CONCLUSION: Colorectal lung and liver metastases showed a distinct immunological architecture. A dense cell infiltration of colorectal lung metastases by CD4+ cells was related to prolonged patient survival. Preoperative chemotherapy did not influence cellular immune infiltrates.

Smad7 regulates compensatory hepatocyte proliferation in damaged mouse liver and positively relates to better clinical outcome in human hepatocellular carcinoma.

Transforming growth factor ß (TGF-ß) is cytostatic towards damage-induced compensatory hepatocyte proliferation. This function is frequently lost during hepatocarcinogenesis, thereby switching the TGF-ß role from tumour suppressor to tumour promoter. In the present study, we investigate Smad7 overexpression as a pathophysiological mechanism for cytostatic TGF-ß inhibition in liver damage and hepatocellular carcinoma (HCC). Transgenic hepatocyte-specific Smad7 overexpression in damaged liver of fumarylacetoacetate hydrolase (FAH)-deficient mice increased compensatory proliferation of hepatocytes. Similarly, modulation of Smad7 expression changed the sensitivity of Huh7, FLC-4, HLE and HLF HCC cell lines for cytostatic TGF-ß effects. In our cohort of 140 HCC patients, Smad7 transcripts were elevated in 41.4% of HCC samples as compared with adjacent tissue, with significant positive correlation to tumour size, whereas low Smad7 expression levels were significantly associated with worse clinical outcome. Univariate and multivariate analyses indicate Smad7 levels as an independent predictor for overall (P<0.001) and disease-free survival (P=0.0123). Delineating a mechanism for Smad7 transcriptional regulation in HCC, we identified cold-shock Y-box protein-1 (YB-1), a multifunctional transcription factor. YB-1 RNAi reduced TGF-ß-induced and endogenous Smad7 expression in Huh7 and FLC-4 cells respectively. YB-1 and Smad7 mRNA expression levels correlated positively (P<0.0001). Furthermore, nuclear co-localization of Smad7 and YB-1 proteins was present in cancer cells of those patients. In summary, the present study provides a YB-1/Smad7-mediated mechanism that interferes with anti-proliferative/tumour-suppressive TGF-ß actions in a subgroup of HCC cells that may facilitate aspects of tumour progression.

Frequency of TERT Promoter Mutations in Prostate Cancer.

OBJECTIVE: Recently, recurrent mutations within the core promoter of the human telomerase reverse transcriptase (TERT) gene generating consensus binding sites for ETS transcription factor family members were described in melanomas and other malignancies (e.g. bladder cancer, hepatocellular carcinoma). These mutations were discussed as early drivers for malignant transformation. In prostate cancer (PrCa) TERT expression has been associated with a poor prognosis and higher risk for disease recurrence. The underlying mechanisms for high TERT expression in PrCa have still not been clarified. To date, data on TERT promoter mutation analysis in PrCa are sparse. Therefore, we performed sequence analysis of the core promoter region of the TERT gene in an unselected cohort of prostate tumors. METHODS: Sections from 167 formalin-fixed, paraffin-embedded and cryopreserved prostate tumors were microdissected and used for DNA isolation. The mutation hotspot region within the TERT core promoter (-260 to +60) was analyzed by direct Sanger sequencing or SNaPshot analysis. RESULTS: All cases were analyzed successfully. Mutations within the core promoter of the TERT gene were not detected in any of the cases with all tumors exhibiting a wild-type sequence. CONCLUSION: TERT core promoter mutations reported from several other malignancies were not detected in our unselected cohort of PrCa. These data indicate that alterations within the core promoter of the TERT gene do not play an important role in prostate carcinogenesis.

Death-associated protein kinase controls STAT3 activity in intestinal epithelial cells.

The TNF-IL-6-STAT3 pathway plays a crucial role in promoting ulcerative colitis-associated carcinoma (UCC). To date, the negative regulation of STAT3 is poorly understood. Interestingly, intestinal epithelial cells of UCC in comparison to ulcerative colitis show high expression levels of anti-inflammatory death-associated protein kinase (DAPK) and low levels of pSTAT3. Accordingly, epithelial DAPK expression was enhanced in STAT3(IEC-KO) mice. To unravel a possible regulatory mechanism, we used an in vitro TNF-treated intestinal epithelial cell model. We identified a new function of DAPK in suppressing TNF-induced STAT3 activation as DAPK siRNA knockdown and treatment with a DAPK inhibitor potentiated STAT3 activation, IL-6 mRNA expression, and secretion. DAPK attenuated STAT3 activity directly by physical interaction shown in three-dimensional structural modeling. This model suggests that DAPK-induced conformational changes in the STAT3 dimer masked its nuclear localization signal. Alternatively, pharmacological inactivation of STAT3 led to an increase in DAPK mRNA and protein levels. Chromatin immunoprecipitation showed that STAT3 restricted DAPK expression by promoter binding, thereby reinforcing its own activation by inducing IL-6. This novel negative regulation principle might balance TNF-induced inflammation and seems to play an important role in the inflammation-associated transformation process as confirmed in an AOM+DSS colon carcinogenesis mouse model. DAPK as a negative regulator of STAT3 emerges as therapeutic option in the treatment of ulcerative colitis and UCC.

Mdm2 SNP309 G-variant is associated with invasive growth of human urinary bladder cancer.

OBJECTIVE: Human mouse double minute 2 (Mdm2) is essential in degrading p53 by acting as an ubiquitin ligase and therefore plays a vital role in cell cycle and survival. The G-variant of the Mdm2 SNP309, which is located within the promoter of the Mdm2 gene, increases expression of Mdm2 and thereby inhibits the p53 pathway. Several studies have investigated the influence of this SNP on disease risk and onset of various malignancies. The impact of Mdm2 SNP309 on bladder cancer is still to be established due to inconsistent data. METHODS: In a case-control study we determined the distribution of Mdm2 SNP309 genotypes in 111 patients with an early-onset bladder cancer (diagnosis <45 years of age), in 113 consecutive bladder cancer patients and in a control group consisting of 140 patients without any malignancy. RESULTS: There was no significant association between the allelic distribution of the Mdm2 SNP309 and tumor risk, early onset, gender or grade of the tumor. According to tumor stage we found a significant difference in the distribution of the Mdm2 SNP309 between patients with noninvasive and invasive (≥pT1) tumor growth (p = 0.016). In patients with invasive tumors a significant increase of the G allele was found (T/T vs. T/G + G/G; p = 0.023; OR 2.203, 95% CI 1.111-4.369). CONCLUSION: These data indicate that the G-variant of the Mdm2 SNP309 might influence the development of a more aggressive tumor phenotype in patients with bladder cancer without affecting the overall tumor risk.

Lack of evidence for frequent MED12 p.L1224F mutation in prostate tumours from Caucasian patients.

Recently mutations in the MED12 gene have been reported in 5.4% of prostate tumours from Caucasian patients analysed by exome sequencing (Barbieri CE, Baca SC, Lawrence MS, et al. Exome sequencing identifies recurrent SPOP, FOXA1 and MED12 mutations in prostate cancer. Nature Genet 2012; 44: 685-689). In more than 70% of prostate tumours with MED12 mutation, a recurrent p.L1224F mutation in exon 26 was found. In order to validate this MED12 p.L1224F mutation, an unselected cohort of prostate tumours from Caucasian patients was analysed by Sanger sequencing. Overall, 223 prostate tumours and three lymph node metastases were analysed. The MED12 p.L1224F mutation could not be detected in any of the cases. So far, the recently reported MED12 p.L1224F mutation could not be validated in our unselected cohort of prostate tumours. Contrary to the findings of Barbieri et al, our data indicate either that the p.L1224F mutation in the MED12 gene plays no role in prostate carcinogenesis or that this alteration is only relevant in a small subgroup of tumours.

Bile duct damage after cold storage of deceased donor livers predicts biliary complications after liver transplantation.

BACKGROUND & AIMS: The aim of this study was to examine the development of biliary epithelial damage between organ retrieval and transplantation and its clinical relevance for patients. METHODS: Common bile duct samples during donor hepatectomy, after cold storage, and after reperfusion were compared to healthy controls by hematoxylin and eosin (H&E) staining and immunofluorescence for tight junction protein 1 and Claudin-1. A bile duct damage score to quantify biliary epithelial injury was developed and correlated with recipient and donor data and patient outcome. RESULTS: Control (N=16) and donor hepatectomy bile ducts (N=10) showed regular epithelial morphology and tight junction architecture. After cold storage (N=37; p=0.0119), and even more after reperfusion (N=62; p=0.0002), epithelial damage, as quantified by the bile duct damage score, was markedly increased, and both tight junction proteins were detected with inappropriate morphology. Patients with major bile duct damage after cold storage had a significantly increased risk of biliary complications (relative risk 18.75; p<0.0001) and graft loss (p=0.0004). CONCLUSIONS: In many cases, the common bile duct epithelium shows considerable damage after cold ischemia with further damage occurring after reperfusion. The extent of epithelial damage can be quantified by our newly developed bile duct damage score and is a prognostic parameter for biliary complications and graft loss. Possibly, in an intraoperative histological examination, this bile duct damage score may influence decision-making in transplantation surgery.

Manganese superoxide dismutase is reduced in the liver of male but not female humans and rodents with non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) is among the most common liver diseases. Oxidative stress is one of the pathogenic mechanisms contributing to the progression of simple fatty liver to non-alcoholic steatohepatitis (NASH). Manganese superoxide dismutase (MnSOD) is a mitochondrial antioxidative enzyme and here its expression in rodent and human NAFLD has been analyzed. MnSOD is found reduced in the liver of male mice fed a high fat diet and male ob/ob mice. Female mice fed an atherogenic diet to induce NASH have MnSOD protein levels comparable to controls. In a cohort of 30 controls, 41 patients with fatty liver and 39 NASH patients, MnSOD mRNA is significantly lower in the steatotic and NASH liver. When analyzed in both genders separately reduction of MnSOD expression is only found in males. Here, MnSOD mRNA negatively correlates with steatosis grade but not with extent of fibrosis or inflammation. MnSOD is, however, not reduced in primary human hepatocytes (PHH) treated with palmitate or oleate to increase cellular triglycerides. Lipopolysaccharide, TNF, IL-6, TGFß and leptin which are all raised in NAFLD do not affect MnSOD in PHH. Adiponectin which attenuates oxidative stress partly by increasing MnSOD in macrophages does not induce MnSOD in PHH. In summary, current data show that hepatic MnSOD is reduced in male but not female humans and rodents with NAFLD.

Mismatch repair proteins hMLH1 and hMSH2 are differently expressed in the three main subtypes of sporadic renal cell carcinoma.

OBJECTIVES: We studied the role of minor mismatch repair proteins (MMR) human MutL homologue 1 (hMLH1) and human MutS homologue 2 (hMSH2) in the main subtypes of renal cell carcinoma (RCC). METHODS: Expression of MMR proteins hMLH1 and hMSH2 were investigated in 166 RCC tumors, containing the main subtypes by immunohistochemistry. Furthermore, each tumor was screened for microsatellite instability (MSI) using the National Cancer Institute consensus panel for hereditary non-polyposis colon carcinoma as well as for elevated microsatellite alterations at selected tetranucleotide repeats (EMAST) by 10 additional markers. RESULTS: MSI was found only in 2.0% of analyzable cases and EMAST was detected only in 1 patient. hMLH1 and hMSH2 expression was reduced in 83.7 (118/141) and 51.2% (65/127) of cases, respectively, in a subtype-specific manner. None of the clear cell RCC tumors retained a high hMLH1 expression and 92.0% lost hMLH1 completely, while papillary and chromophobe RCC preserved the expression in 25.0 and 33.3% of cases (p < 0.001). Subtype specificity was also present in hMSH2 staining, where chromophobe RCC retained a high expression in 41.7% of cases, while clear cell and papillary tumors did not (29.9 and 23.1%; p = 0.01). CONCLUSION: MSI and EMAST are rare events in sporadic RCC, whereas diminished MMR protein expression is linked to tumor entity and might contribute to the different biological behavior of the RCC subtypes.

Outcome of patients with ischemic-like cholangiopathy with secondary sclerosing cholangitis after liver transplantation.

BACKGROUND AND AIMS: Sclerosing cholangitis in critically ill patients (SC-CIP) with sepsis and acute respiratory distress syndrome (ARDS) is a cholestatic liver disease with a rapid progression to liver cirrhosis and hepatic failure. Data on outcome of these patients after liver transplantation (LT) are sparse. PATIENTS AND METHODS: Eleven patients (46 ± 12 years; mean labMELD-score: 27 ± 7) with SC-CIP underwent LT. Six patients had severe polytrauma with multiple bone fractures, sepsis and ARDS. Five non-traumatic patients acquired SC-CIP during long-term intensive-care-unit stays due to sepsis and ARDS. Time to diagnosis, the microbiologic results and the survival rates after LT were evaluated. RESULTS: SC-CIP was diagnosed by endoscopic retrograde cholangiopancreatography (ERCP) within 3 ± 1 months after manifestation of cholestasis and histologically confirmed in explanted livers. The predominant microorganisms isolated in bile were: Enterococcus and Candida albicans. Mean follow-up after LT was 28 ± 20 months. One female patient (non-traumatic) died due to sepsis 26 days after LT. All other patients left the hospital alive, but two (non-traumatic) patients died from sepsis, and one (traumatic) patient died in a hemorrhagic shock, thereafter. Seven of 11 patients (5 with polytrauma) are still alive and have a good quality of life. The survival of the SC-CIP patients after LT was comparable with that of patients transplanted due to alcoholic liver cirrhosis. CONCLUSION: SC-CIP develops rapidly within several months. Enterococcus and C. albicans were the main isolated microorganisms in the bile. Sepsis was the main cause of death after LT. Overall, SC-CIP is a good indication for LT in selected patients.

Causes of bolus impaction in the esophagus.

BACKGROUND: Bolus impaction in the esophagus is a common indication for emergency endoscopy. The aim of this study was to determine the most common causes of esophageal bolus impaction. METHODS: In this retrospective study, data of 54 patients (41 male, 13 female) with bolus impaction in the esophagus were analyzed. Type and localization of the bolus and the endoscopic extraction tool used were evaluated. In 48 of 54 patients (89%), biopsy samples were taken of the esophagus for histological examination. RESULTS: Mean age of the patients was 53 ± 20 years. Fourteen of 54 patients (26%) had experienced bolus impaction previously. Meat bolus (n = 35, 65%) was the most common cause of esophageal obstruction. In most cases, boluses were found in either the distal (n = 31) or the proximal (n = 18) esophagus. In 22 patients (41%), the bolus was pushed into the stomach by the endoscope. In most other cases the bolus, including foreign bodies, could be removed with the 5-arm polyp grasper or alligator forceps. Main causes of bolus impaction were eosinophilic esophagitis (n = 10) or reflux disease with or without peptic stenosis (n = 10), respectively. CONCLUSION: Bolus impaction is frequently correlated with eosinophilic esophagitis and reflux esophagitis; therefore, diagnostic workup should include esophageal biopsy sampling.

Expression of CD24, P-cadherin and S100A4 in tumors of the ampulla of Vater.

Carcinomas of the Vaterian system are rare and presumably arise from preexisting adenomas (adenoma-carcinoma-sequence). Usually, biopsies are obtained to confirm and specify endoscopic findings, but differentiating reactive atypia from dysplasia or dysplasia from invasive carcinoma can sometimes be difficult or even impossible on morphological criteria alone. In case of invasive carcinoma, furthermore, the precise classification of carcinoma subtypes needs to be established since the distinct subtypes differ significantly in terms of clinical outcome. The cell adhesion proteins CD24, P-cadherin and S100A4 were shown to be expressed in several carcinomas and in dysplastic epithelium but only rarely in normal mucosa. We therefore investigated their expression in 177 carcinoma, 114 adenoma and 152 normal mucosa specimens of the ampulla of Vater. Although the expression of the cell adhesion proteins did not differ between the carcinoma subtypes, marked differences between normal mucosa, adenoma and carcinoma samples were observed. All marker proteins were expressed in less than 7% of normal mucosa samples (S100A4 in only 1% of cases) and showed an increasing expression from adenoma to invasive carcinoma. Our findings suggest that P-cadherin and S100A4 are helpful in discriminating normal mucosa or reactive atypia from neoplastic lesions. CD24 and S100A4, furthermore, can assist in the differential diagnosis of dysplasia vs invasive carcinoma.

A urinary metabolite constellation to detect acute rejection in kidney allografts.

BACKGROUND: To validate a novel method for post-transplant surveillance to detect kidney allograft rejection via a characteristic constellation of the urine metabolites alanine, citrate, lactate, and urea investigated by nuclear magnetic resonance (NMR) spectroscopy a first prospective, observational study was performed. METHODS: Within the UMBRELLA study 986 urine specimens were collected from 109 consecutively enrolled renal transplant recipients, and metabolite constellations were analyzed. A metabolite rejection score was calculated and compared to histopathological results of corresponding indication and protocol allograft biopsies (n = 206). FINDINGS: The metabolite constellation was found to be a useful biomarker to non-invasively detect acute allograft rejection (AUC = 0.75; 95% confidence interval (CI) 0.68-0.83; based on 46 cases and 520 control samples). Combined analysis of the metabolite rejection score and the estimated glomerular filtration rate (eGFR) at the time of urine sampling further improved the overall test performance significantly (AUC = 0.84; 95% CI 0.76-0.91; based on 42 cases and 468 controls). Regarding the time course analysis in patients without rejection episodes the test results remained well below a diagnostic threshold associated with high risk of acute rejection. In other cases, a marked increase above this threshold indicated acute allograft rejection already six to ten days before diagnostic renal biopsies were performed. INTERPRETATION: A combination of an NMR-based urine metabolite analysis and eGFR is promising as a non-invasive test for post-transplant surveillance and to support decision making whether renal allografts need histopathological evaluation.

MethyQESD, a robust and fast method for quantitative methylation analyses in HNPCC diagnostics using formalin-fixed and paraffin-embedded tissue samples.

Promoter hypermethylation occurs in various tumors and leads to silencing of tumor-relevant genes. Thus, promoter methylation analysis (MA) has been established as an important tool in cancer research and diagnostics. Here we present MethyQESD (methylation-quantification of endonuclease-resistant DNA) as a fast, easy, precise and reliable method for quantitative MA without the need of bisulfite-treatment or fluorescent probes. Though MethyQESD principally works with any gene promoter we established MethyQESD for the mismatch repair gene MLH1 and tested its utility to differentiate between sporadic microsatellite unstable (MSI-H) colorectal cancer and hereditary nonpolyposis colorectal cancer (HNPCC) by quantitative MLH1 MA. We investigated formalin-fixed and paraffin-embedded tissue samples from a previously published, well-characterized tumor collective comprising 25 HNPCC, 14 sporadic MSI-H CRC and 16 sporadic microsatellite stable (MSS) CRC. We found a high accuracy of MethyQESD by spiking experiments with dilution series of methylated (SW48 cancer cell line) and unmethylated (blood) DNA (Pearson's r=0.9997 (proximal MLH1 promoter region), r=0.9976 (distal MLH1 promoter region)). MethyQESD and conventional quantitative MA using of 96 formalin-fixed and paraffin-embedded CRC showed a high degree of concordance of both methods (Pearson's r=0.885). HNPCC tumors showed either null MLH1 methylation or a significantly lower degree of MLH1 methylation than sporadic MSI-H CRC (P<0.001). MLH1 methylation was negative in all MSS tumors. Receiver operating characteristic (ROC) curve analyses defined a cutoff value of 16.5% MLH1 methylation for specific and sensitive identification of sporadic MSI-H CRC (area under ROC curve: 1.000; asymptotic significance: P<0.001). Thus, quantitative MLH1 MA by MethyQESD provides a simple, fast and valuable tool to identify HNPCC candidates. Furthermore, MethyQESD works reliably with formalin-fixed paraffin-embedded tissue and simplifies DNA MA both for research and diagnostic purposes.