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See detailEnzymes from Cold-Adapted Microorganisms. The Class C Beta-Lactamase from the Antarctic Psychrophile Psychrobacter Immobilis A5
Feller, Georges ULg; Zekhnini, Z.; Lamotte-Brasseur, J. et al

in European Journal of Biochemistry (1997), 244(1), 186-91

A heat-labile beta-lactamase has been purified from culture supernatants of Psychrobacter immobilis A5 grown at 4 degrees C and the corresponding chromosomal ampC gene has been cloned and sequenced. All ... [more ▼]

A heat-labile beta-lactamase has been purified from culture supernatants of Psychrobacter immobilis A5 grown at 4 degrees C and the corresponding chromosomal ampC gene has been cloned and sequenced. All structural and kinetic properties clearly relate this enzyme to class C beta-lactamases. The kinetic parameters of P. immobilis beta-lactamase for the hydrolysis of some beta-lactam antibiotics are in the same range as the values recorded for the highly specialized cephalosporinases from pathogenic mesophilic bacteria. By contrast, the enzyme displays a low apparent optimum temperature of activity and a reduced thermal stability. Structural factors responsible for the latter property were analysed from the three-dimensional structure built by homology modelling. The deletion of proline residues in loops, the low number of arginine-mediated H-bonds and aromatic-aromatic interactions, the lower global hydrophobicity and the improved solvent interactions through additional surface acidic residues appear to be the main determinants of the enzyme flexibility. [less ▲]

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See detailEnzymes from psychrophiles
Feller, Georges ULg; Narinx, Emmanuel; Arpigny, Jean Louis et al

Conference (1996)

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See detailEnzymes from psychrophiles : an unachieved adaptation
Gerday, Charles ULg; Feller, Georges ULg

Conference (2000)

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See detailEnzymes from psychrophilic organisms
Feller, Georges ULg; Narinx, E.; Arpigny, J. L. et al

in FEMS Microbiology Reviews (1996), 18(2-3), 189-202

Psychrophilic organisms such as micro-organisms and other ectothermic species living in polar, deep- sea or any constantly low temperature environments, produce enzymes adapted to function at low ... [more ▼]

Psychrophilic organisms such as micro-organisms and other ectothermic species living in polar, deep- sea or any constantly low temperature environments, produce enzymes adapted to function at low temperature. These enzymes are characterized by a high catalytic efficiency at low and moderate temperatures but are rather thermolabile. Due to their high specific activity and their rapid inactivation at temperatures as low as 30 degrees C, they offer, along with the producing micro-organisms, a great potential in biotechnology. The molecular basis of the adaptation of cold cu-amylase, subtilisin, triose phosphate isomerase from Antarctic bacteria and of trypsin from fish living in North Atlantic and in Antarctic sea waters have been studied. The comparison of the 3D structures obtained either by protein modelling or by X-ray crystallography (North Atlantic trypsin) with those of their mesophilic counterparts indicates that the molecular changes tend to increase the flexibility of the structure by a weakening of the intramolecular interactions and by an increase of the interactions with the solvent. For each enzyme, the most appropriate strategy enabling it to accommodate the substrate at a low energy cost is selected. There is a price to pay in terms of thermosensibility because the selective pressure is essentially oriented towards the harmonization of the specific activity with ambient thermal conditions. However, as demonstrated by site-directed mutagenesis experiments carried out on the Antarctic subtilisin, the possibility remains to stabilize the structure of these enzymes without affecting their high catalytic efficiency. [less ▲]

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See detailEnzymes in animal feed.
Rossi, Florence; Thewis, André ULg

in Fifteenth Forum for Applied Biotechnology (2001)

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See detailEnzymes involved in wall peptide crosslinking in Escherichia coli K12, strain 44
Nguyen-Distèche, Martine ULg; Ghuysen, Jean-Marie ULg; Pollock, Jerry J. et al

in European Journal of Biochemistry (1974), 41(3), 447-455

By using the glutamate-amidated tetrapeptide l-alanyl-d-isoglutaminyl-(l)-meso-diamino-pimelyl-(l)-d-alanine as a probe, there appears to exist in the membranes of Escherichia coli K12 strain 44 a dd ... [more ▼]

By using the glutamate-amidated tetrapeptide l-alanyl-d-isoglutaminyl-(l)-meso-diamino-pimelyl-(l)-d-alanine as a probe, there appears to exist in the membranes of Escherichia coli K12 strain 44 a dd-carboxypoptidase-transpeptidase system which does not recognize this peptide and a dd-carboxypoptidase-transpeptidase system which recognizes it. The dd-carboxypeptidase-endopeptidase system is essentially hydrolytic. It catalyzes the hydrolysis of UDP-N-acetyl-muramyl-pentapeptide into UDP-N-acetylmuramyl-tetrapeptide and the hydrolysis of the wall peptidoglycan peptide dimer into monomers. These activities are not inhibited by the glutamate-amidated tetrapeptide. The system may consist either of two enzyme proteins having predominantly carboxypeptidase activity and endopeptidase activity, respectively, or of one enzyme protein of which the functioning would depend upon the environmental conditions. The dd-carboxypeptidase-transpeptidase system (a) catalyzes concomitant hydrolysis (carboxypeptidase activity) and transfer (natural model transpeptidase activity) reactions with the pentapeptide l-alanyl-γ-d-glutamyl-(l)-meso-diaminopimelyl-(l)-d-alanyl-d-alanine. The transfer reaction leads to the synthesis of a dimer that is identical to the one which occurs in the E. coli wall peptidoglycan; (b) utilizes the glutamate-amidated tetrapeptide as an acceptor. Simultaneous exposure of the pentapeptide and the glutamate-amidated tetrapeptide to the enzyme system leads to the formation of an hybrid monoamidated peptide dimer and causes a decreased hydrolysis of the pentapeptide; (c) by virtue of its own carboxypeptidase activity, it appears to exert some endopeptidase activity. Both carboxypeptidase and endopeptidase activities of this system are inhibited by the glutamate-amidated tetrapeptide, but this represents only a small fraction of the total hydrolytic activity of the membrane Brij-36T extract. (d) The system catalyzes an unnatural model transpeptidation reaction in which glycine replaces d-alanine at the C-terminal position of the nucleotide UDP-N-acetylmuramyl-pentapeptide. This system may also consist either of two enzyme proteins having predominantly natural model transpeptidase activity and unnatural model transpeptidase activity, respectively, or of one enzyme protein of which the functioning would depend upon the environmental conditions. Whatever the exact situation, the E. colidd-carboxypeptidase-transpeptidase system is in many respects, similar to the dd-carboxy-peptidase-transpeptidase single polypeptide enzymes isolated from Streptomyces strains R39 and R61. [less ▲]

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See detailEnzymes that degrade bacterial cell walls
Ghuysen, Jean-Marie ULg; Tipper, Donald J.; Strominger, Jack L.

in Methods in Enzymology (1966), 8

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See detailLes enzymes: produits de la biotechnologie pour l'agro-alimentaire.
Thonart, Philippe ULg; Hubert, J. B.; Rikir, R. et al

in Annales de Gembloux (1989), 95

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See detailEOF analysis of long-term reconstructed AVHRR Pathfinder SST in the South China Sea
Huynh, Thi Hong Ngu ULg; Alvera Azcarate, Aïda ULg; Barth, Alexander ULg et al

Poster (2014, May 02)

Sea surface temperature (SST) is one of the key variables often used to investigate ocean dynamics, ocean-atmosphere interaction, and climate change. For recent decades, the AVHRR Pathfinder SST, measured ... [more ▼]

Sea surface temperature (SST) is one of the key variables often used to investigate ocean dynamics, ocean-atmosphere interaction, and climate change. For recent decades, the AVHRR Pathfinder SST, measured by infrared sensors, has been widely used because of its high resolution and long time-series. The disadvantage of the AVHRR Pathfinder SST is high percentage of missing data due to cloud coverage. This becomes more serious in the South China Sea (SCS) because it is located in the tropical region, frequently covered by clouds. In this study, we used the Data INterpolating Empirical Orthogonal Functions (DINEOF) method to reconstruct daily night-time 4 km AVHRR Pathfinder SST spanning from 1989 to 2009 for the whole SCS. In order to better understand the spatial and temporal variability of the SCS SST, an EOF analysis of the reconstructed field is performed in association with surface wind. The first SST mode, accounting for 69% of the variance, presents the cooling (warming) of the basin due to the solar inclination through seasons, water exchange, topography, and monsoon-induced cyclonic circulation. The second SST mode, explaining 24.8% of the variance, shows the advection of cold and warm water from two opposite directions along the southwest-northeast diagonal of the basin. The second SST mode is affected by the atmospheric anticyclone (cyclone) located over the Philippine Sea. Comparing both SST modes with Nino3.0 index, it shows that the interannual variability of the SCS SST is influenced by the moderate and strong ENSO events with a lag of 5-6 months. Moreover, the analysis of the high-resolution reconstructed dataset reveals some oceanic features that could not be captured in previous EOF analyses. [less ▲]

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See detailEOF analysis of Sea Surface Temperature in the Canary Island - Madeira region
Troupin, Charles ULg; Alvera Azcarate, Aïda ULg; Barth, Alexander ULg et al

Conference (2011, April 05)

We analyzed Sea Surface Temperature (SST) images in a region covering the Canary Islands and Madeira archipelagos, with the following objectives 1. The reconstruction of incomplete SST satellite images ... [more ▼]

We analyzed Sea Surface Temperature (SST) images in a region covering the Canary Islands and Madeira archipelagos, with the following objectives 1. The reconstruction of incomplete SST satellite images during the year 2009. 2. The determination of the main spatial and temporal patters in the region. SST images for 2009 are downloaded from the Medspiration project (http://www.medspiration.org). The images consist of combined measurements from several satellite systems. The images with less than 5% of valid pixels (e.g., clouds) were removed, so that out of the 365 initial images, 347 were kept. The method used in this work for the reconstruction of missing data is Data INterpolating Empirical Orthogonal Functions (DINEOF, Alvera-Azcárate et al., 2005). The results show that the first mode is largely dominant, with 87% of the variance explained, and represents the regional seasonal cycle. The second mode accounts for 9% of the variance and depicts a separation between coastal waters and open-ocean waters. The signal of the Cape Ghir upwelling filament is also present in the second mode. The reconstruction allows one to reproduce the characteristic mesoscale features of the region: the coastal upwelling, the island wakes (Gran Canaria, Madeira, ... ), the filament and the eddies in the lee of the main islands. A near-operational version of the reconstruction has been implemented and is available at http://gher-diva.phys.ulg.ac.be/DINEOF/dineof_allCAN.html [less ▲]

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See detailEOF calculations and data filling from incomplete oceanographic datasets
Beckers, Jean-Marie ULg; Rixen, M.

in Journal of Atmospheric and Oceanic Technology (2003), 20(12), 1839-1856

The paper presents a new self-consistent method to infer missing data from oceanographic data series and to extract the relevant empirical orthogonal functions. As a by-product, the new method allows for ... [more ▼]

The paper presents a new self-consistent method to infer missing data from oceanographic data series and to extract the relevant empirical orthogonal functions. As a by-product, the new method allows for the detection of the number of statistically significant EOFs by a cross-validation procedure for a complete or incomplete dataset, as well as the noise level and interpolation error. Since the proposed filling and analysis method does not need a priori information about the error covariance structure, the method is self-consistent and parameter free. [less ▲]

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See detailAn EOF-based technique to compute merged high resolution sea surface temperature fields
Alvera Azcarate, Aïda ULg; Troupin, Charles ULg; Barth, Alexander ULg et al

Conference (2012, May 10)

High quality sea surface temperature (SST) data sets are needed for various applications, including numerical weather prediction, ocean forecasting and climate research. The coverage, resolution and ... [more ▼]

High quality sea surface temperature (SST) data sets are needed for various applications, including numerical weather prediction, ocean forecasting and climate research. The coverage, resolution and precision of individual SST satellite observations is not sufficient for these applications, therefore the merging of these complementary data sets is needed to reduce the final data set error. This is usually performed by optimal interpolation (OI).We present an extension of the capabilities of DINEOF (Data INterpolating Empirical Orthogonal Functions) to merge data from different platforms. The analysis is based on the formalism of OI, but the crucial difference is that the error covariance is not parametrized a priori using an analytical expression, but expressed using a spatial EOF basis calculated by DINEOF. This EOF basis represents more realistically the complex variability of SST data sets than the parametric covariance used in most OI applications. An example will be presented using data from a polar-orbiting satellite (AVHRR on MetOp) and a geostationary satellite (SEVIRI on MSG). The high spatial resolution of the polar-orbiting satellite and the high temporal resolution of the geostationary satellite are retained to create a very high spatial and temporal resolution field of the western Mediterranean SST. The results are validated with independent data. [less ▲]

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See detailEORTC Leukemia Group achievements
Willemze, Roel; Suciu, Stefan; Marie, Jean-Pierre et al

in EJC Supplements (2012), I

The EORTC Leukemia Group (LG) has a long history of promoting the study of leukemias and related malignancies and reports here on three of their most significant achievements. In acute myelogenous ... [more ▼]

The EORTC Leukemia Group (LG) has a long history of promoting the study of leukemias and related malignancies and reports here on three of their most significant achievements. In acute myelogenous leukemia (AML), the LG and Italian group GIMEMA started their fruitful collaboration in 1986 with the AML-8 trial with 1519 inclusions. In the AML-8A trial, in patients who reached complete remission, without a HLA identical sibling, autograft provided longer disease-free survival than a second course of consolidation, whereas the best outcome was observed in patients with a donor, who had to be allografted. The AML-10 trial set a new standard of treatment for induction/consolidation with replacement of daunorubicin by either idarubicin or mitoxantrone. The AML-12 trial tested the effect of high-dose cytosinearabinoside during induction (2109 inclusions, data base locked in August 2011 for final analysis). Development of intergroup trials focusing on subgroups of AML bearing specific genetic abnormalities is now mandatory to validate the “targeted approach” of driving molecular events. In high-risk myelodysplastic syndrome (MDS), the phase III trial conducted by the LG in collaboration with the German MDS Study Group showed that the response rate of decitabine versus best supportive care was higher (complete or partial remissions, 19% versus 0%, and hematologic improvement, 15% versus 2%), progression-free survival was significantly prolonged (median 6.6 versus 3 months), cumulative incidence of AML was significantly decreased (22% versus 33% at one year), but the impact on OS was less evident (median 10.1 versus 8.5 months; hazard ratio 0.88). Quality of life had improved significantly in patients in the decitabine arm. The assessment of HDAC inhibitors, such as vorinostat, will probably be tested in the next trial. Also in MDS, relevant genetic lesions involved in the pathogenesis of this disease were identified using single nucleotide polymorphisms array-based genomic profiling and genomic sequencing in 102 patients with MDS. Acquired abnormalities of the TET2 gene were identified in 26% of the cases and in the EZH2 gene in 5−10% of the patients. TET2 mutations were detected in 96% of the bone marrow cells, including CD34+ progenitor cells, suggesting that TET2 mutations could be an early event during disease evolution. In normal bone marrow, TET2 expression was elevated in granulocytes, suggesting a role in myelopoiesis. Conclusion: during the last 25 years the EORTC LG in cooperation with GIMEMA made a considerable contribution to the improvement of treatment results of patients with acute leukemia or MDS. [less ▲]

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See detailEORTC Radiation Oncology Group quality assurance platform: Establishment of a digital central review facility
Fairchild, A.; Aird, E.; Fenton, P. A. et al

in Radiotherapy & Oncology (2012), 103(3), 279-286

Objective: Quality assurance (QA) in clinical trials is essential to ensure treatment is safely and effectively delivered. As QA requirements have increased in complexity in parallel with evolution of ... [more ▼]

Objective: Quality assurance (QA) in clinical trials is essential to ensure treatment is safely and effectively delivered. As QA requirements have increased in complexity in parallel with evolution of radiation therapy (RT) delivery, a need to facilitate digital data exchange emerged. Our objective is to present the platform developed for the integration and standardization of QART activities across all EORTC trials involving RT. Methods: The following essential requirements were identified: secure and easy access without on-site software installation; integration within the existing EORTC clinical remote data capture system; and the ability to both customize the platform to specific studies and adapt to future needs. After retrospective testing within several clinical trials, the platform was introduced in phases to participating sites and QART study reviewers. Results: The resulting QA platform, integrating RT analysis software installed at EORTC Headquarters, permits timely, secure, and fully digital central DICOM-RT based data review. Participating sites submit data through a standard secure upload webpage. Supplemental information is submitted in parallel through web-based forms. An internal quality check by the QART office verifies data consistency, formatting, and anonymization. QART reviewers have remote access through a terminal server. Reviewers evaluate submissions for protocol compliance through an online evaluation matrix. Comments are collected by the coordinating centre and institutions are informed of the results. Conclusions: This web-based central review platform facilitates rapid, extensive, and prospective QART review. This reduces the risk that trial outcomes are compromised through inadequate radiotherapy and facilitates correlation of results with clinical outcomes. © 2012 Elsevier Ireland Ltd. All rights reserved. [less ▲]

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See detailEORTC-ROG expert opinion: Radiotherapy volume and treatment guidelines for neoadjuvant radiation of adenocarcinomas of the gastroesophageal junction and the stomach
Matzinger, O.; Gerber, E.; Bernstein, Z. et al

in Radiotherapy & Oncology (2009), 92(2), 164-175

Purpose: The Gastro-Intestinal Working Party of the EORTC Radiation Oncology Group (GIWP-ROG) developed guidelines for target volume definition in neoadjuvant radiation of adenocarcinomas of the ... [more ▼]

Purpose: The Gastro-Intestinal Working Party of the EORTC Radiation Oncology Group (GIWP-ROG) developed guidelines for target volume definition in neoadjuvant radiation of adenocarcinomas of the gastroesophageal junction (GEJ) and the stomach. Methods and materials: Guidelines about the definition of the clinical target volume (CTV) are based on a systematic literature review of the location and frequency of local recurrences and lymph node involvement in adenocarcinomas of the GEJ and the stomach. Therefore, MEDLINE was searched up to August 2008. Guidelines concerning prescription, planning and treatment delivery are based on a consensus between the members of the GIWP-ROG. Results: In order to support a curative resection of GEJ and gastric cancer, an individualized preoperative treatment volume based on tumour location has to include the primary tumour and the draining regional lymph nodes area. Therefore we recommend to use the 2nd English Edition of the Japanese Classification of Gastric Carcinoma of the Japanese Gastric Cancer Association which developed the concept of assigning tumours of the GEJ and the stomach to anatomically defined sub-sites corresponding respectively to a distinct lymphatic spread pattern. Conclusion: The GIWP-ROG defined guidelines for preoperative irradiation of adenocarcinomas of the GEJ and the stomach to reduce variability in the framework of future clinical trials. © 2009 Elsevier Ireland Ltd. All rights reserved. [less ▲]

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See detailEosiniphilic bronchopulmonary disease in dogs (EBP): a clinical analysis of 25 cases.
Clercx, Cécile ULg; Snaps, Frédéric ULg; Peeters, Dominique ULg et al

in Proceedings of the 8th Annual Congress of the ESVIM (1998)

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See detailEosinophile Bronchopneumonie
Clercx, Cécile ULg

in Proceedings of the 34. Internationaler Fortbildungskurs Kleintierkrankheiten : “Thorax – Herz- und Lungenerkrankungen" - Flims -Switzerland (2013, February)

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See detailEosinophilic Bronchopneumopathy
Clercx, Cécile ULg

in Proceedings 35 Internationaler Fortbildungskurs Kleintierkrankheiten (2014)

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See detailEosinophilic Bronchopneumopathy in Dogs
Clercx, Cécile ULg; Peeters, Dominique ULg; Snaps, Frédéric ULg et al

in Journal of Veterinary Internal Medicine (2000), 14(3, May-Jun), 282-91

Eosinophilic bronchopneumopathy was diagnosed in 23 young dogs. Clinical signs included cough, gagging, and retching in all dogs, dyspnea in 21 dogs (91%), and nasal discharge in 12 dogs (52%). The most ... [more ▼]

Eosinophilic bronchopneumopathy was diagnosed in 23 young dogs. Clinical signs included cough, gagging, and retching in all dogs, dyspnea in 21 dogs (91%), and nasal discharge in 12 dogs (52%). The most common radiographic findings were a moderate to severe bronchointerstitial pattern (68%, 13 of 19 dogs). Bronchoscopic findings included the presence of abundant yellow-green mucus or mucopurulent material (70%, 16 of 23 dogs) and severe mucosal thickening with an irregular or polypoid appearance (52%, 12 of 23 dogs), with partial airway closure during expiration in 3 dogs (13%). Peripheral blood eosinophilia was noted in 14 of 23 dogs (61%). Inflammatory cells in brush or bronchoalveolar lavage fluid cytologic preparations comprised more than 50% eosinophils in 14 of 23 dogs (61%), and 20-50% eosinophils in 6 dogs (26%). Eosinophilic infiltration of the bronchial mucosa was observed in biopsies from 19 dogs and was graded as mild (37%, 7 dogs), moderate (32%, 6 dogs), or severe (32%, 6 dogs). The mean serum immunoglobulin A concentration was almost double that of a population of 20 healthy dogs of various breeds. Oral glucocorticoids were administered on alternate days with progressive tapering of the dose; the dosage at maintenance varied between 0.1 and 1.0 mg/kg every other day. No relationship was found between the duration of clinical signs and the maintenance dosage or the cytologic and histopathologic grades. [less ▲]

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See detaileosinophilic esophagitis
Leclercq, Philippe ULg; Marting, Audrey; Gast, Pierrette ULg

in New England Journal of Medicine [=NEJM] (2007), 357(14),

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