Protist-Type Lysozymes of the Nematode Caenorhabditis elegans Contribute to Resistance against Pathogenic Bacillus thuringiensis

Pathogens represent a universal threat to other living organisms. Most organisms express antimicrobial proteins and peptides, such as lysozymes, as a protection against these challenges. The nematode Caenorhabditis elegans harbours 15 phylogenetically diverse lysozyme genes, belonging to two distinct types, the protist- or Entamoeba-type (lys genes) and the invertebrate-type (ilys genes) lysozymes. In the present study we characterized the role of several protist-type lysozyme genes in defence against a nematocidal strain of the Gram-positive bacterium Bacillus thuringiensis. Based on microarray and subsequent qRT-PCR gene expression analysis, we identified protist-type lysozyme genes as one of the differentially transcribed gene classes after infection. A functional genetic analysis was performed for three of these genes, each belonging to a distinct evolutionary lineage within the protist-type lysozymes (lys-2, lys-5, and lys-7). Their knock-out led to decreased pathogen resistance in all three cases, while an increase in resistance was observed when two out of three tested genes were overexpressed in transgenic lines (lys-5, lys-7, but not lys-2). We conclude that the lysozyme genes lys-5, lys-7, and possibly lys-2 contribute to resistance against B. thuringiensis, thus highlighting the particular role of lysozymes in the nematode's defence against pathogens

Belgian experience of robot assisted laparoscopic para – aortic lymphadenectomy for staging of locally advanced cervical carcinoma. A multicentric study.

Objectives: FIGO clinical staging, imaging techniques sometimes underestimate extension of locally advanced cervical cancer (LACC). The presence of para-aortic lymph node (LN) metastases in LACC identifies patients with poor prognosis. Laparoscopic para-aortic lymphadenectomy is now proposed as a diagnostic tool. Feasibility and safety of robot assisted laparoscopic para-aortic lymphadenectomy has been reported. We collected data from different Belgian centers to assess its oncological safety and complication rate. Study design: Three centers participated in the study. Thirty seven patients with LACC underwent a pre treatment robot assisted laparoscopic para-aortic lymphadenectomy. Data was prospectively collected. Results: The median number of LN collected was 27.5 (1-54) per patient. Five out of 37 patients had para-aortic node metastasis. The false negative rate for PET CT diagnosing para- aortic node metastasis was 10.8% (4/37). We encountered 2 major intra operative complications (5.4%). Post operative morbidity was low (13.5%). Median follow up was 27 months (95% CI 24–30). Median disease free survival (DFS) was 16 months (95% CI 2.4- 29.6). Patients with negative LN had a median DFS of 24 months (NA) although patients with positive LN had a median DFS of 9 months (95% CI 6.9-11.9). Conclusions: In this series we report that robot assisted laparoscopic para-aortic lymphadencetomy provided the surgeon with useful information to avoid understaging in 10.8% of women with LACC, at the expense of low morbidity (13.5%). Presence of microscopic para-aortic LN metastasis is correlated with shorter DFS. The number of patients with positive LN doesn’t allow us to draw any firm conclusion

Selection of metalloenzymes by catalytic activity using phage display and catalytic elution.

The metallo-beta-lactamase betaLII from Bacillus cereus 569/H/9 was displayed on the filamentous phage fd. The phage-bound enzyme fd-betaLII was shown to be active on benzylpenicillin as substrate; it could be inactivated by complexation of the essential zinc(II) ion with EDTA and reactivated by addition of a zinc(II) salt. A selection process was designed to extract active phage-bound enzymes from libraries of mutants in three steps: 1. inactivation of active phage-bound enzymes by metal ion complexation, 2. binding to substrate-coated magnetic beads, 3. release of phages capable of transforming the substrate into product upon zinc salt addition. The selection process was first successfully tested on model mixtures containing fd-betaLII plus either a dummy phage, a phage displaying an inactive mutant of the serine beta-lactamase TEM-1, or inactive and low-activity mutants of betaLII. The selection was then applied to extract active phage-bound enzymes from a library of mutants generated by mutagenic polymerase chain reaction (PCR). The activity of the library was shown to increase 60-fold after two rounds of selection. Eleven clones from the second round were randomly picked for sequencing and to characterize their activity and stability

Peptide nanofibers with dynamic instability through non-equilibrium biocatalytic assembly

We demonstrate supramolecular peptide nanofibers that display dynamic instability, i.e. they are formed by competing assembly and dis-assembly reactions, where assembly is favoured away from equilibrium. The systems are based on competitive catalytic transacylation and hydrolysis, producing a self-assembling aromatic peptide derivative from amino acid precursors, that temporarily exceeds the critical gelation concentration, until the competing hydrolytic reaction takes over. Analysis by atomic force microscopy shows consecutive nanofiber formation and shortening. The process results in macroscopically observable temporary hydrogelation, which may be repeated upon refuelling the system with further addition of the chemically activated amino acid pre-cursor. Non-equilibrium nanostructures open up opportunities for mimicry of the behaviour dynamic gels found in natural systems and provide components for future adaptive nanotechnologies

Evaluation of 18FDG PET-CT in the diagnosis of endometriosis: a prospective study.

Noninvasive techniques have poor sensitivity and specificity in diagnosing endometriosis, which is often associated with an inflammatory process. In several benign diseases, measurement of hypermetabolism using fluorodeoxyglucose (18F 18FDG) reflects the degree of inflammation and aggressiveness of the disease. This prospective study evaluated the value of (18)FDG positron emission tomography (PET)-computed tomography (CT) in assessing the presence of endometriosis.Evaluation StudiesJournal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe

A collaborative approach for human-centered driver assistance systems

Abstract – This paper describes an interdisciplinary research collaboration to design a human-centered driver assistance system. Driving behavior is captured using a novel intelligent vehicle test bed. The synchronized capture of driver behavior and driving context provides an empirical basis for design and evaluation.