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Colorectal cancer (CRC) is one of the most frequent malignancies in the Western world. Early tumor detection and intervention are important determinants on CRC patient survival. During early tumor proliferation, dissemination and angiogenesis, platelets store and segregate proteins actively and selectively. Hence, the platelet proteome is a potential source of biomarkers denoting early malignancy. By comparing protein profiles of platelets between healthy volunteers ( n = 12) and patients with early- ( n = 7) and late-stage ( n = 5) CRCs using multiplex fluorescence two-dimensional gel electrophoresis (2D-DIGE), we aimed at identifying differentially regulated proteins within platelets. By inter-group comparisons, 94 differentially expressed protein spots were detected ( p < 0.05) between healthy controls and patients with early- and late-stage CRCs and revealed distinct separations between all three groups in principal component analyses. 54 proteins of interest were identified by mass spectrometry and resulted in high-ranked Ingenuity Pathway Analysis networks associated with Cellular function and maintenance, Cellular assembly and organization, Developmental disorder and Organismal injury and abnormalities ( p < 0.0001 to p = 0.0495). Target proteins were validated by multiplex fluorescence-based Western blot analyses using an additional, independent cohort of platelet protein samples [healthy controls ( n = 15), early-stage CRCs ( n = 15), late-stage CRCs ( n = 15)]. Two proteins-clusterin and glutathione synthetase (GSH-S)-featured high impact and were subsequently validated in this independent clinical cohort distinguishing healthy controls from patients with early- and late-stage CRCs. Thus, the potential of clusterin and GSH-S as platelet biomarkers for early detection of CRC could improve existing screening modalities in clinical application and should be confirmed in a prospective multicenter trial. [ABSTRACT FROM AUTHOR]

Purpose: Cancer risk assessment for ulcerative colitis patients by evaluating histological changes through colonoscopy surveillance is still challenging. Thus, additional parameters of high prognostic impact for the development of colitis-associated carcinoma are necessary. This meta-analysis was conducted to clarify the value of aneuploidy as predictor for individual cancer risk compared with current surveillance parameters. Methods: A systematic web-based search identified studies published in English that addressed the relevance of the ploidy status for individual cancer risk during surveillance in comparison to neoplastic mucosal changes. The resulting data were included into a meta-analysis, and odds ratios (OR) were calculated for aneuploidy or dysplasia or aneuploidy plus dysplasia. Results: Twelve studies addressing the relevance of aneuploidy compared to dyplasia were comprehensively evaluated and further used for meta-analysis. The meta-analysis revealed that aneuploidy (OR 5.31 [95 % CI 2.03, 13.93]) is an equally effective parameter for cancer risk assessment in ulcerative colitis patients as dysplasia (OR 4.93 [1.61, 15.11]). Strikingly, the combined assessment of dysplasia and aneuploidy is superior compared to applying each parameter alone (OR 8.99 [3.08, 26.26]). Conclusions: This meta-analysis reveals that aneuploidy is an equally effective parameter for individual cancer risk assessment in ulcerative colitis as the detection of dysplasia. More important, the combined assessment of dysplasia and aneuploidy outperforms the use of each parameter alone. We suggest image cytometry for ploidy assessment to become an additional feature of consensus criteria to individually assess cancer risk in UC. [ABSTRACT FROM AUTHOR]

We show existence of surfaces of prescribed mean curvature in central projection for such values of the mean curvature for which estimates for the corresponding Euler-Lagrange equations are generally not known. This is achieved by extending the variational problem to the space $${BV(\Omega)}$$ , where graphs in a cone must satisfy a side condition, and using variational methods. Moreover, we give an example of a solution in $${BV(\Omega)}$$ which does not solve the Dirichlet problem for the Euler-Lagrange equation. [ABSTRACT FROM AUTHOR]

Purpose: Aneuploidy has long been suggested as an independent prognostic marker for colorectal cancer (CRC) patients and could thus aid for individualized medicine. However, due to a large spectrum of deviating studies, expert panels do not recommend ploidy assessment. In order to clarify a potential bias of stage-specific frequency of aneuploidy, we now conducted a meta-analysis combined with a systematic review regarding aneuploidy and prognosis. Methods: A systematic, web-based search process retrieved 1935 studies published in English between 1990 and 2011. The defined endpoint for the meta-analysis was an increase in aneuploidy frequency between early- (Dukes A, B and UICC I, II; n = 3632 samples) and late-stage (Dukes C, D and UICC III, IV; n = 3440 samples) colorectal carcinomas. Results: Of 1935 studies initially identified, 17 image (2130 patients) and 20 (7023 patients) flow cytometric studies were analyzed in detail. The meta-analysis (7072 patients) revealed late-stage CRC to be more frequently aneuploid than early-stage CRC (odds ratio 1.51, 95 % CI 1.37-1.67; p = 0.0007). Independent of tumor stage, the overall range of aneuploidy was 39 to 81 % (median 58 %), and altogether, 21 (54.1 %) studies described a significant prognostic impact of aneuploidy for overall, disease-specific, and recurrence-free survival, respectively. Conclusions: A substantial number of studies showed a prognostic importance of aneuploidy in CRC. Furthermore, the higher frequency of aneuploidy in late-stage CRC implies an increase in genomic instability with CRC progression, indicating aneuploidy to be also a stage-specific prognostic marker. [ABSTRACT FROM AUTHOR]

Purpose: The risk, prevention, and treatment of colorectal neoplasia in inflammatory bowel disease (IBD) are still a matter of debate. The aim of this study was to analyze the occurrence of colorectal neoplasia in IBD patients who underwent proctocolectomy. Methods: The study population comprised of 123 IBD patients who underwent proctocolectomy because of neoplasia, therapy refractivity, or complications between January 2000 and July 2011. Results: One hundred fourteen (92.7 %) patients were pre-operatively diagnosed with ulcerative colitis, 5 (4.1 %) with colitis indeterminata, and 4 (3.3 %) with colonic Crohn's disease. Colectomy was indicated in 39 (31.7 %) patients because of a neoplasia, in 68 (55.3 %) because of a refractory course of the disease, and in 16 (13.0 %) because of complications. Neoplasia was found in 36 patients on a histopathologic evaluation of the colectomy specimens. Ten (8.1 %) patients post-operatively showed a pre-operatively not described advanced neoplasia. In three (2.4 %) of these patients, the detection of advanced neoplasia (two high-grade intraepithelial neoplasias (IENs), one carcinoma) was a complete de novo finding. Carcinoma had not been diagnosed pre-operatively in six (4.9 %) patients. A multifocal distribution of neoplasia was seen in 66.7 % of patients with neoplasia. The median duration of disease was 15.5 years in case of neoplasia opposed to 6.0 years in those without neoplasia detection. Conclusion: Our data demonstrate a high rate of pre-operatively undetected high-grade IENs and carcinoma and a frequent multifocal occurrence in IBD patients with long-standing inflammation of the colon. This should be kept in mind for treatment decisions particularly in patients with a chronic refractory course of the disease. [ABSTRACT FROM AUTHOR]

This paper studies parabolic quasiminimizers which are solutions to parabolic variational inequalities. We show that, under a suitable regularity condition on the boundary, parabolic Q-quasiminimizers related to the parabolic p-Laplace equations with given boundary values are stable with respect to parameters Q and p. The argument is based on variational techniques, higher integrability results and regularity estimates in time. This shows that stability does not only hold for parabolic partial differential equations but it also holds for variational inequalities. [ABSTRACT FROM AUTHOR]

For weak solutions of nonlinear elliptic systems of the type $${- {\rm div}a(x, u(x), Du(x)) = 0,}$$ with nonstandard p( x) growth, we show interior partial Hölder continuity for any Hölder exponent $${\alpha \in (0,1)}$$, provided that the exponent function is 'logarithmic Hölder continuous'. The result also covers the up to now open partial regularity for systems with constant growth with exponent p less than two in the case of merely continuous dependence on the spacial variable x. [ABSTRACT FROM AUTHOR]

Purpose: Presently, no markers exist to predict metachronous metastasis at the time a primary colorectal cancer is diagnosed. While aneuploidy indicates poor survival prognosis and elevated carcinoembryonic antigen (CEA) levels the presence of recurrent disease, the predictive value of both markers regarding imminent metachronous metastases is unclear. Methods: Sixty patients with distant recurrence throughout a 5-year follow-up (TM+) were randomly chosen and 60 patients without metastasis matched to this cohort (TM−). In addition, an enlarged collective ( n = 217; n = 85, n = 132) with median follow-up of 79.2 months was assessed by logistic regression regarding metachronous metastases. Univariate and stepwise regression analyses included clinicopathological characteristics, preoperative CEA levels and aneuploidy assessed by DNA image cytometry. Results: The matched-pair collective showed aneuploidy in 71.1 % (TM−) and 85.0 % (TM+; p = 0.076), and elevated CEA in 24.5 % (TM−) and 52.2 % [TM+; odds ratio (OR), 3.414; p = 0.007]. The enlarged collective presented aneuploidy in 71.2 % (TM−) and 83.5 % (TM+; OR 2.050, p = 0.038), and elevated CEA in 28.6 % (TM−) and 48.9 % (TM+; OR 2.391, p = 0.020). Elevated CEA and aneuploidy did not show any association ( p = 0.919). In contrast, logistic regression analyses demonstrated that besides increased T category (OR 1.745, p = 0.019), both elevated CEA level (OR 2.633, p = 0.015) and aneuploidy (OR 1.929, p = 0.058) were independent predictive markers for metachronous metastasis. Conclusions: Our data show that aneuploidy and elevated CEA levels besides increased T category could serve for individual risk assessment to predict metachronous metastases. The fact that still aneuploidy missed the significance level by a small margin emphasizes the need for larger validation studies. [ABSTRACT FROM AUTHOR]

We study non-linear parabolic systems with non-standard p( z)-growth conditions and establish that the gradient of weak solutions is locally Hölder continuous with Hölder exponent $${\beta \in (0,1)}$$ with respect to the parabolic metric on an open set of full Lebesgue measure, provided the exponent function p( z) itself is Hölder continuous with exponent β with respect to the parabolic metric. [ABSTRACT FROM AUTHOR]

DNA aneuploidy has been identified as a prognostic factor in the majority of epithelial malignancies. We aimed at identifying ploidy-associated protein expression in endometrial cancer of different prognostic subgroups. Comparison of gel electrophoresis-based protein expression patterns between normal endometrium ( n = 5), diploid ( n = 7), and aneuploid ( n = 7) endometrial carcinoma detected 121 ploidy-associated protein forms, 42 differentially expressed between normal endometrium and diploid endometrioid carcinomas, 37 between diploid and aneuploid endometrioid carcinomas, and 41 between diploid endometrioid and aneuploid uterine papillary serous cancer. Proteins were identified by mass spectrometry and evaluated by Ingenuity Pathway Analysis. Targets were confirmed by liquid chromatography/mass spectrometry. Mass spectrometry identified 41 distinct polypeptides and pathway analysis resulted in high-ranked networks with vimentin and Nf-κB as central nodes. These results identify ploidy-associated protein expression differences that overrule histopathology-associated expression differences and emphasize particular protein networks in genomic stability of endometrial cancer. [ABSTRACT FROM AUTHOR]

DNA aneuploidy has been identified as a prognostic factor for epithelial malignancies. Further understanding of the translation of DNA aneuploidy into protein expression will help to define novel biomarkers to improve therapies and prognosis. DNA ploidy was assessed by image cytometry. Comparison of gel-electrophoresis-based protein expression patterns of three diploid and four aneuploid colorectal cancer cell lines detected 64 ploidy-associated proteins. Proteins were identified by mass spectrometry and subjected to Ingenuity Pathway Analysis resulting in two overlapping high-ranked networks maintaining Cellular Assembly and Organization, Cell Cycle, and Cellular Growth and Proliferation. CAPZA1, TXNL1, and HDAC2 were significantly validated by Western blotting in cell lines and the latter two showed expression differences also in clinical samples using a tissue microarray of normal mucosa ( n = 19), diploid ( n = 31), and aneuploid ( n = 47) carcinomas. The results suggest that distinct protein expression patterns, affecting TXNL1 and HDAC2, distinguish aneuploid with poor prognosis from diploid colorectal cancers. [ABSTRACT FROM AUTHOR]

Membrane proteins account for 70-80% of all pharmaceutical targets emphasizing their clinical relevance. Identification of new, differentially expressed membrane proteins reflecting distinct disease properties is thus of high importance. Unfortunately, isolation and analysis of membrane-bound proteins is hampered by their relative low abundance in total cell lysates, their frequently large size and their hydrophobic properties. We thus aimed to identify protocols that allow for highly efficient isolation and purification of membrane-bound proteins for subsequent protein profiling. We present a comparative study of different membrane protein extraction methods that vary in total protein yield between 0.02 and 4.8 mg using constant cell pellets of the colorectal carcinoma cell line SW620. We also demonstrate by means of polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis that the majority of commercial membrane extraction kits harbor a substantial cytosolic contamination of their membranous fraction. Based on purity of membranous fraction, protein yield, time and costs, we show superiority of two commercial extraction kits for downstream proteome analyses of membrane proteins. [ABSTRACT FROM AUTHOR]

Colorectal cancer is the second leading cause of cancer-related death. Current clinical practice in colorectal cancer screening (fecal occult blood test, FOBT; colonoscopy) has contributed to a reduction of mortality. However, despite these screening programs, about 70% of carcinomas are detected at advanced tumor stages (UICC III/IV) presenting poor patient prognosis. Thus, innovative tools and methodologies for early cancer detection can directly result in improving patient survival rates. Biomedical research has advanced rapidly in recent years with the availability of technologies such as global gene and protein expression profiling. Comprehensive tumor profiling has become a field of intensive research aiming at identifying biomarkers relevant for improved diagnostics and therapeutics. In this paper, we report a comprehensive review of genomic, transcriptomic, and proteomic approaches for biomarker identification in tissue and blood with a main emphasis on two-dimensional gel-electrophoresis (2-DE) and mass spectrometry analyses. Proteomics-based technologies enable to distinguish the healthy patient from the tumor patient with high sensitivity and specificity and could greatly improve common classification systems and diagnostics. However, this progress has not yet been transferred from bench to bedside but could open the door to a more accurate and target specific personalized medicine with improved patient survival. [ABSTRACT FROM AUTHOR]

Two-dimensional gel electrophoresis (2-DE) is commonly used to analyze and separate complex mixtures of intact proteins. It delivers a map of proteins which reflects changes in protein expression level, isoforms and post-translational modifications. In this protocol, we describe an optimized workflow with standardized sample preparation for the 2-DE to exploit all methodical and technical potentials. [ABSTRACT FROM AUTHOR]