Is early limited surgery associated with a more benign disease course in Crohn’s disease?

AIM: To analyze the difference in disease course and need for surgery in patients with Crohn's disease (CD). METHODS: Data of 506 patients with incident CD were analyzed (age at diagnosis: 31.5 ± 13.8 years). Both hospital and outpatient records were collected prospectively with a complete clinical follow-up and comprehensively reviewed in the population-based Veszprem province database, which includes incident CD patients diagnosed between January 1, 1977 and December 31, 2008. Follow-up data were collected until December 31, 2009. All patients included had at least 1 year of follow-up available. Patients with indeterminate colitis at diagnosis were excluded from the analysis. RESULTS: Overall, 73 patients (14.4%) required resective surgery within 1 year of diagnosis. Steroid exposure and need for biological therapy were lower in patients with early limited surgery (P < 0.001 and P = 0.09). In addition, surgery rates during follow-up in patients with and without early surgery differed significantly after matching on propensity scores (P < 0.001, HR = 0.23). The need for reoperation was also lower in patients with early limited resective surgery (P = 0.038, HR = 0.42) in a Kaplan-Meier and multivariate Cox regression (P = 0.04) analysis. However, this advantage was not observed after matching on propensity scores (P(Logrank) = 0.656, P(Breslow) = 0.498). CONCLUSION: Long-term surgery rates and overall exposure to steroids and biological agents were lower in patients with early limited resective surgery, but reoperation rates did not differ

A versatile modular vector set for optimizing protein expression among bacterial, yeast, insect and mammalian hosts

We have developed a unified, versatile vector set for expression of recombinant proteins, fit for use in any bacterial, yeast, insect or mammalian cell host. The advantage of this system is its versatility at the vector level, achieved by the introduction of a novel expression cassette. This cassette contains a unified multi-cloning site, affinity tags, protease cleavable linkers, an optional secretion signal, and common restriction endonuclease sites at key positions. This way, genes of interest and all elements of the cassette can be switched freely among the vectors, using restriction digestion and ligation without the need of polymerase chain reaction (PCR). This vector set allows rapid protein expression screening of various hosts and affinity tags. The reason behind this approach was that it is difficult to predict which expression host and which affinity tag will lead to functional expression. The new system is based on four optimized and frequently used expression systems (Escherichia coli pET, the yeast Pichia pastoris, pVL and pIEx for Spodoptera frugiperda insect cells and pLEXm based mammalian systems), which were modified as described above. The resulting vector set was named pONE series. We have successfully applied the pONE vector set for expression of the following human proteins: the tumour suppressor RASSF1A and the protein kinases Aurora A and LIMK1. Finally, we used it to express the large multidomain protein, Rho-associated protein kinase 2 (ROCK2, 164 kDa) and demonstrated that the yeast Pichia pastoris reproducibly expresses the large ROCK2 kinase with identical activity to the insect cell produced counterpart. To our knowledge this is among the largest proteins ever expressed in yeast. This demonstrates that the cost-effective yeast system can match and replace the industry-standard insect cell expression system even for large and complex mammalian proteins. These experiments demonstrate the applicability of our pONE vector set

Application of a Short, Disordered N-Terminal Flagellin Segment, a Fully Functional Flagellar Type III Export Signal, to Expression of Secreted Proteins ▿

Recently, we have demonstrated that the 26-47 segment of Salmonella enterica serovar Typhimurium flagellin is capable of mediating flagellar export. In order to reveal whether other parts of the N-terminal region have any significant influence on secretion, a series of plasmids were constructed containing the lac promoter followed by the 26-47, 2-65, or 2-192 portion of Salmonella flagellin, to which various heterologous proteins of different size were fused (18 constructs overall). Essentially, all three segments could drive protein export; however, the nature of the attached polypeptide also had a significant effect on secretion efficiency. When low export efficiency was observed, it was mainly caused by inclusion body formation. Our data provide strong support for the idea that a short segment within the disordered N-terminal region of axial proteins is recognized by the flagellar type III export machinery. The 26-47 segment of flagellin contains all of the necessary information to direct translocation of attached polypeptide chains. This short (positions 26 to 47) flagellin segment attached to recombinant proteins can be used for secreted protein expression. Certain fusion proteins that are easily degraded within the cells were found to be intact in the medium, implying a potential application of this expression system for proteins with high proteolytic susceptibility

Monoclonal antibody proteomics: use of antibody mimotope displaying phages and the relevant synthetic peptides for mAb scouting.

Monoclonal antibody proteomics uses nascent libraries or cloned (Plasmascan™, QuantiPlasma™) libraries of mAbs that react with individual epitopes of proteins in the human plasma. At the initial phase of library creation, cognate protein antigen and the epitope interacting with the antibodies are not known. Scouting for monoclonal antibodies (mAbs) with the best binding characteristics is of high importance for mAb based biomarker assay development. However, in the absence of the identity of the cognate antigen the task represents a challenge. We combined phage display, and surface plasmon resonance (Biacore) experiments to test whether specific phages and the respective mimotope peptides obtained from large scale studies are applicable to determine key features of antibodies for scouting. We show here that mAb captured phage-mimotope heterogeneity that is the diversity of the selected peptide sequences, is inversely correlated with an important binding descriptor; the off-rate of the antibodies and that represents clues for driving the selection of useful mAbs for biomarker assay development. Carefully chosen synthetic mimotope peptides are suitable for specificity testing in competitive assays using the target proteome, in our case the human plasma

Monoclonal antibody proteomics: use of antibody mimotope displaying phages and the relevant synthetic peptides for mAb scouting

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Association of extraintestinal manifestations and anaemia with disease outcomes in patients with inflammatory bowel disease

OBJECTIVE The association between extraintestinal manifestations (EIMs) and disease activity suggest a common pathogenetic link with inflammatory bowel disease (IBD). We report on the association of EIMs and anaemia with long-term disease outcomes, including treatment steps, hospitalization, and surgery in the prospective population-based IBD inception cohort from Veszprem province. METHODS Data of 678 incident IBD patients (Crohn's disease/ulcerative colitis(CD/UC): 331/347) diagnosed from 1st January 2000 to 31st December 2012 were analyzed (CD: m/f: 176/155, median age at diagnosis: 28, IQR: 21-40 years, disease duration: 6, IQR: 2-9 years; UC: m/f: 200/147, median age at diagnosis: 36, IQR: 26-50 years, duration: 7, IQR: 4-10 years). RESULTS EIMs were present in 30% of the CD and 17.3% of the UC patients. In CD, female gender (p = 0.02) need for steroid (p  < 0.001) and azathioprine (AZA) (p = 0.02), while in UC, young age at onset (p = 0.03), extensive disease (p = 0.003), female gender (p = 0.07), need for steroids (p < 0.001) and AZA (p = 0.004) and need for IBD-related hospitalization (p = 0.01) were associated with the presence of EIMs. Anaemia was present in 56.7% of the CD and 30.2% of the UC patients. In both CD and UC anaemia was associated with age at onset (pCD = 0.001, pUC = 0.04), disease location/extent (pCD = 0.02, pUC < 0.001), steroid and AZA use (for both pCD,UC < 0.001), need for surgery/colectomy (pCD < 0.001, pUC = 0.002) and hospitalization (pCD = 0.004, pUC < 0.001) and in CD, it was associated with anti TNF therapy(p = 0.002). CONCLUSIONS The presence of EIMs was associated with disease phenotype in UC and with treatment strategy in both CD and UC. Additionally, anaemia was associated with hospitalization and surgery in both CD and UC, suggesting that EIMs and anaemia may be helpful in stratifying disease severity in IBD