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See detailThe in-vitro antimicrobial activity of some medicinal plants against beta-lactam-resistant bacteria
Gangoue Pieboji, Joseph ULg; Eze, N.; Ngongang Djintchui, A. et al

in J Infect Dev Ctries (2009), 3(9), 671-80

BACKGROUND: In effort to identify novel bacterial agents, this study was initiated to evaluate the antimicrobial properties of 17 crude extracts from 12 medicinal plants against beta-lactam-resistant ... [more ▼]

BACKGROUND: In effort to identify novel bacterial agents, this study was initiated to evaluate the antimicrobial properties of 17 crude extracts from 12 medicinal plants against beta-lactam-resistant bacteria. METHODOLOGY: The antimicrobial activities of plant extracts were evaluated against clinically proved beta-lactam-resistant bacteria (Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Serratia marcescens, Acinetobacter baumannii, Staphylococcus aureus and Enterococcus sp.) and reference strains of bacteria (Escherichia coli ATCC 35218, Enterobacter aerogenes ATCC 29751, E. aerogenes ATCC 13048, Pseudomonas aeruginosa ATCC 27853 and Enterococcus hirae ATCC 9790) by using disc-diffusion and agar-dilution assays. RESULTS: The crude plant extracts demonstrated broad spectrum activity against all bacteria tested with inhibition zones in the range of 8-30 mm. The minimal inhibitory concentration (MIC) values of different plant extracts against the tested bacteria were found to range from <or= 0.3 to >or= 10 mg ml(-1). The most active plant extracts were from Dortenia picta and Bridelia micrantha (MIC: 1.25-10 mg ml(-1)) on beta-lactam-resistant Gram-negative bacilli and the extracts from B. micrantha, Mallotus oppositifolius, Garcinia lucida, Garcinia. kola, Campylospermum densiflorum (leaves) and C. zenkeri (root) on beta-lactam-resistant Gram-positive cocci (MIC: <or= 0.3-5 mg ml(-1)). CONCLUSION: Of the 17 plant extracts studied, seven showed good antimicrobial activity against the tested bacteria. The stem bark of B. micrantha and the leaves of D. picta were most active towards beta-lactamase producing Gram-negative bacilli. This study shows that medicinal plants could be sources of compounds which can be used to fight against beta-lactam resistant bacteria. [less ▲]

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See detailIn-Vitro Differences among Nonsteroidal Antiinflammatory Drugs in Their Activities Related to Osteoarthritis Pathophysiology
Henroitin, Y.; Reginster, Jean-Yves ULg

in Osteoarthritis and Cartilage (1999), 7(3), 355-7

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See detailIN-VITRO EVALUATION OF A-5021 ANTI-VIRAL ACTIVITY AGAINST TESTUDINID HERPESVIRUS 3 AND INITIAL PHARMACOKINETIC STUDY IN HERMANN'S TORTOISE (Testudo hermanni)
Gandar, Frederic ULg; Vrancken, Robert; Diez, Marianne ULg et al

Conference (2013, April 23)

Testudinid herpesvirus infections in tortoises belonging to the Testudinidae family are well known for decades, but their pathogenesis remains poorly understood and treatments are often empirical. This ... [more ▼]

Testudinid herpesvirus infections in tortoises belonging to the Testudinidae family are well known for decades, but their pathogenesis remains poorly understood and treatments are often empirical. This study describes the in vitro evaluation of selected anti-herpesvirus compounds against Testudinid Herpesvirus 3 (THV-3). A-5021, a compound with known broad-spectrum anti-herpetic activity, showed to be 9 times more potent than acyclovir, with an EC50 of 13.2 µM and inducing a complete inhibition of viral replication at 37.7 µM. Initial pharmacokinetic parameters were determined after a single sub-cutaneous administration of 5 and 10 mg/kg in Hermann’s tortoises (Testudo hermanni, n=3). Blood samples were collected at different time points and plasma concentrations of A-5021 were determined. No adverse effects were clinically observed and plasma concentrations remained above the EC50 for 2.8 and 4.2 h after administration of 5 and 10 mg/kg, respectively. These preliminary data provide a basis for further proof-of-concept studies for a potential prophylactic or therapeutic treatment of THV-3 infection in tortoises [less ▲]

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See detailIn-vitro evaluation of drugs proposed as chondroprotective agents.
Bassleer, C.; Henrotin, Yves ULg; Franchimont, P.

in International Journal of Tissue Reactions (1992), 14(5), 231-41

Three proposed chondroprotective agents (CP), namely glucosamine sulfate (GAS), chondroitin sulfate (CS) and glycosaminoglycan-peptide complex (GP-C), were tested on differentiated human articular ... [more ▼]

Three proposed chondroprotective agents (CP), namely glucosamine sulfate (GAS), chondroitin sulfate (CS) and glycosaminoglycan-peptide complex (GP-C), were tested on differentiated human articular chondrocytes cultured in clusters. Chondrocyte productions of proteoglycans (PG), type II collagen (coll. II) and prostaglandin E2 (PGE2) were established by specific radioimmunoassays applied to the culture medium (CM) and in chondrocyte clusters (CC). Collagenolytic activity was assayed in CM. DNA synthesis, studied by measuring 3H-thymidine incorporation, was unaffected by CS and GAS. GP-C, at low concentration, stimulated DNA synthesis. GP-C, at higher doses, induced a high increase in PG and coll. II productions. GAS and CS induced a stimulatory effect limited to PG production. None of the CP tested here affected the basal PGE2 production by human chondrocytes. [less ▲]

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See detailIn-vivo studies on Haemaccel-fibronectin interaction in man.
Damas, Pierre ULg; Adam, Aurore ULg; Buret, J. et al

in European Journal of Clinical Investigation (1987), 17(2), 166-73

An enzyme-linked immunoassay has been recently set up for direct measurement of the binding capacity of plasma fibronectin to gelatin. This binding capacity could be completely inhibited in vitro by an ... [more ▼]

An enzyme-linked immunoassay has been recently set up for direct measurement of the binding capacity of plasma fibronectin to gelatin. This binding capacity could be completely inhibited in vitro by an eight-fold excess of gelatin, of Haemaccel, but not of Geloplasma. On the contrary, the levels of immunoreactive fibronectin measured by laser nephelometry did not change, in presence of 10 to 1000 micrograms ml-1 of gelatin, of Haemaccel or of Geloplasma. When infused into normal volunteers, Haemaccel provoked a strong and immediate inhibition of the plasma fibronectin binding capacity to gelatin. This inhibition was dose-dependent and maximal after infusion of 500 ml of Haemaccel. Twenty-four hours after this infusion, there was a progressive recovery of the gelatin-binding capacity, which was almost completely achieved 96 h later. The formation of complexes between Haemaccel and fibronectin was demonstrated by gel filtration chromatography and by affinity chromatography. Immunoreactive plasma fibronectin levels remained unchanged up to 24 h after infusion of 500 ml of Haemaccel. A transient decline to 50% of its initial value then occurred the second day after the infusion. Therefore, a delay existed between the formation of fibronectin-Haemaccel complexes and their elimination from the bloodstream. This delay decreased when smaller volumes of Haemaccel were infused, which strongly suggests that plasma fibronectin is cleared by means of Haemaccel and does not seem to play a role of opsonin in these conditions.(ABSTRACT TRUNCATED AT 250 WORDS) [less ▲]

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See detailInactivated Bovine Herpesvirus 1 Induces Apoptotic Cell Death of Mitogen-Stimulated Bovine Peripheral Blood Mononuclear Cells
Hanon, E.; Vanderplasschen, Alain ULg; Lyaku, S. et al

in Journal of Virology (1996), 70(6), 4116-4120

Bovine herpesvirus 1 (BHV-1) is able to inhibit the proliferation of bovine peripheral blood mononuclear cells. Here, we have demonstrated that live BHV-1 and, interestingly, inactivated BHV-1 can induce ... [more ▼]

Bovine herpesvirus 1 (BHV-1) is able to inhibit the proliferation of bovine peripheral blood mononuclear cells. Here, we have demonstrated that live BHV-1 and, interestingly, inactivated BHV-1 can induce apoptosis of mitogen-stimulated bovine peripheral blood mononuclear cells in vitro. [less ▲]

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See detailInactivation of Aeromonas Hydrophila Metallo-Beta-Lactamase by Cephamycins and Moxalactam
Zervosen, Astrid ULg; Valladares, Maria Hernandez; Devreese, Bart et al

in European Journal of Biochemistry (2001), 268(13), 3840-50

Incubation of moxalactam and cefoxitin with the Aeromonas hydrophila metallo-beta-lactamase CphA leads to enzyme-catalyzed hydrolysis of both compounds and to irreversible inactivation of the enzyme by ... [more ▼]

Incubation of moxalactam and cefoxitin with the Aeromonas hydrophila metallo-beta-lactamase CphA leads to enzyme-catalyzed hydrolysis of both compounds and to irreversible inactivation of the enzyme by the reaction products. As shown by electrospray mass spectrometry, the inactivation of CphA by cefoxitin and moxalactam is accompanied by the formation of stable adducts with mass increases of 445 and 111 Da, respectively. The single thiol group of the inactivated enzyme is no longer titrable, and dithiothreitol treatment of the complexes partially restores the catalytic activity. The mechanism of inactivation by moxalactam was studied in detail. Hydrolysis of moxalactam is followed by elimination of the 3' leaving group (5-mercapto-1-methyltetrazole), which forms a disulfide bond with the cysteine residue of CphA located in the active site. Interestingly, this reaction is catalyzed by cacodylate. [less ▲]

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See detailInactivation of alpha(2)-Macroglobulin by Activated Human Polymorphonuclear Leukocytes.
Deby, Ginette ULg; Croisier, Jean-Louis ULg; Camus, Gérard et al

in Mediators of Inflammation (1994), 3(2), 117-23

The proteolytic activity of trypsin releases the dye Remazol Brilliant Blue from its high molecular weight substrate, the skin powder (Hide Powder Azure, Sigma), with an increase in absorbance at 595 nm ... [more ▼]

The proteolytic activity of trypsin releases the dye Remazol Brilliant Blue from its high molecular weight substrate, the skin powder (Hide Powder Azure, Sigma), with an increase in absorbance at 595 nm. Active alpha(2)- macroglobulin (80 mug/ml) totally inhibits the proteolytic activity of trypsin (14 mug/ml) by trapping this protease. But after a 20 min incubation of alpha(2)-macroglobulin at 37 degrees C with 2 x 10(6) human polymorphonuclear leukocytes activated by N-formyl-L-methionyl-L-leucyl-L-phenylalanine (10(-7) M) and cytochalasin B (10(-8) M), 100% of trypsin activity was recovered, indicating a total inactivation of alpha(2)-macroglobuHn. Incubation with granulocyte myeloperoxidase also inactivates alpha(2)-macroglobulin. Hypochlorous acid, a by-product of myeloperoxidase activity, at a concentration of 10(-7) M also inactivates alpha(2)-macroglobulin, which indicates that an important cause of alpha(2)-macroglobulin inactivation by activated polymorphonuclear leukocytes could be the activity of myeloperoxidase. [less ▲]

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See detailInactivation of bacterial DD-peptidase by beta-sultams.
Llinas, Antonio; Ahmed, Naveed; Cordaro, Massimiliano et al

in Biochemistry (2005), 44(21), 7738-46

N-Acyl-beta-sultams are time-dependent, irreversible active site-directed inhibitors of Streptomyces R61 DD-peptidase. The rate of inactivation is first order with respect to beta-sultam concentration ... [more ▼]

N-Acyl-beta-sultams are time-dependent, irreversible active site-directed inhibitors of Streptomyces R61 DD-peptidase. The rate of inactivation is first order with respect to beta-sultam concentration, and the second-order rate constants show a dependence on pH similar to that for the hydrolysis of a substrate. Inactivation is due to the formation of a stable 1:1 enzyme-inhibitor complex as a result of the active site serine being sulfonylated by the beta-sultam as shown by ESI-MS analysis and by X-ray crystallography. A striking feature of the sulfonyl enzyme is that the inhibitor is not bound to the oxyanion hole but interacts extensively with the "roof" of the active site where the Arg 285 is located. [less ▲]

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See detailInactivation of cellulase in stirred bioreactor : solution of the problem and scale up rules
Meurisse, E.; Evrard, J.F.; Denoo, O. et al

Poster (1995)

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See detailInactivation of E. coli RNA polymerase by pyridoxal 5′-phosphate: Identification of a low pKa lysine as the modified residue
Bull, Paulina; Zaldivar, Josefina; Venegas, Alejandro et al

in Biochemical and Biophysical Research Communications (1975), 64(4), 1152-1159

The inactivation of E. coli RNA polymerase (3.3 × 10−7M) by pyridoxal 5′-phosphate (1 × 10−4M to 5 × 10−4M) is a first order process with respect to the remaining active enzyme. Studies of the variation ... [more ▼]

The inactivation of E. coli RNA polymerase (3.3 × 10−7M) by pyridoxal 5′-phosphate (1 × 10−4M to 5 × 10−4M) is a first order process with respect to the remaining active enzyme. Studies of the variation of the first order rate constant with the concentration of pyridoxal 5′-phosphate show that the inactivation reaction follows saturation kinetics. The formation of a reversible enzyme-inhibitor intermediate is postulated. Kinetic studies at different pH values indicate that the inactivation rate constant depends on the mole fraction of one conjugate base with pKa 7.9. The apparent equilibrium constant (association) for the inactivation reaction is independent of the pH and is 1.8 × 104 M−1. By electrophoretic and chromatographic analysis of enzyme hydrolyzates after pyridoxal 5′-phosphate and NaBH4 treatment only N-ε-pyridoxyllysine was found. It is postulated that a lysine ε-amino group with a low pKa is critical for the activity of the enzyme. [less ▲]

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See detailInactivation of genes coding for mitochondrial Nd7 and Nd9 complex I subunits in Chlamydomonas reinhardtii. Impact of complex I loss on respiration and energetic metabolism.
Massoz, Simon; Larosa, Véronique ULg; Plancke, Charlotte et al

in Mitochondrion (2013)

In Chlamydomonas, unlike in flowering plants, genes coding for Nd7 (NAD7/49kDa) and Nd9 (NAD9/30kDa) core subunits of mitochondrial respiratory-chain complex I are nucleus-encoded. Both genes possess all ... [more ▼]

In Chlamydomonas, unlike in flowering plants, genes coding for Nd7 (NAD7/49kDa) and Nd9 (NAD9/30kDa) core subunits of mitochondrial respiratory-chain complex I are nucleus-encoded. Both genes possess all the features that facilitate their expression and proper import of the polypeptides in mitochondria. By inactivating their expression by RNA interference or insertional mutagenesis, we show that both subunits are required for complex I assembly and activity. Inactivation of complex I impairs the cell growth rate, reduces the respiratory rate, leads to lower intracellular ROS production and lower expression of ROS scavenging enzymes, and is associated to a diminished capacity to concentrate CO2 without compromising photosynthetic capacity. [less ▲]

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See detailInactivation of nucleolin leads to nucleolar disruption, cell cycle arrest and defects in centrosome duplication.
Ugrinova, Iva; Monier, Karine; Ivaldi, Corinne et al

in BMC Molecular Biology (2007), 8

BACKGROUND: Nucleolin is a major component of the nucleolus, but is also found in other cell compartments. This protein is involved in various aspects of ribosome biogenesis from transcription regulation ... [more ▼]

BACKGROUND: Nucleolin is a major component of the nucleolus, but is also found in other cell compartments. This protein is involved in various aspects of ribosome biogenesis from transcription regulation to the assembly of pre-ribosomal particles; however, many reports suggest that it could also play an important role in non nucleolar functions. To explore nucleolin function in cell proliferation and cell cycle regulation we used siRNA to down regulate the expression of nucleolin. RESULTS: We found that, in addition to the expected effects on pre-ribosomal RNA accumulation and nucleolar structure, the absence of nucleolin results in a cell growth arrest, accumulation in G2, and an increase of apoptosis. Numerous nuclear alterations, including the presence of micronuclei, multiple nuclei or large nuclei are also observed. In addition, a large number of mitotic cells showed a defect in the control of centrosome duplication, as indicated by the presence of more than 2 centrosomes per cell associated with a multipolar spindle structure in the absence of nucleolin. This phenotype is very similar to that obtained with the inactivation of another nucleolar protein, B23. CONCLUSION: Our findings uncovered a new role for nucleolin in cell division, and highlight the importance of nucleolar proteins for centrosome duplication. [less ▲]

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See detailInactivation of rat liver RNA polymerases I and II and yeast RNA polymerase I by pyrodixal 5'-phosphate. Evidence for the participation of lysyl residues at the active site.
Martial, Joseph ULg; Zaldivar, J.; Bull, P. et al

in Biochemistry (1975), 14

Purified DNA-dependent RNA polymerase forms I (A) and II (B) from rat liver and form I from yeast are rapidly inactivated by pyridoxal 5'-phosphate at pH 8.0. The inhibition is relatively specific since ... [more ▼]

Purified DNA-dependent RNA polymerase forms I (A) and II (B) from rat liver and form I from yeast are rapidly inactivated by pyridoxal 5'-phosphate at pH 8.0. The inhibition is relatively specific since pyridoxamine 5'-phosphate is not an inhibitor and pyridoxal is about 12 times less effective than pyridoxal 5'-phosphate. The inactivation is reversed by high concentrations of amines, and can be made irreversible by reduction with NaBH4. Spectral analysis of the inhibited enzyme and its NaBH4 reduction product indicates that a Schiff base forms between the aldehyde group of pyridoxal 5'-phosphate and one or more amino groups of the protein. Nepsilon-Pyridoxyllysine was identified as the only product in acid hydrolysates of the reduced yeast RNA polymerase I-pyridoxal 5'-phosphate complex. Complete inactivation of yeast polymerase I results in the incorporation of 3-4 mol of pyridoxal 5'-phosphate/1 mol of enzyme. DNA and nucleotide substrates partially protect the enzymes from inactivation. These results suggest that one or more lysyl amino groups are critical for the activity of animal RNA polymerases and show that pyridoxal 5'-phosphate is a suitable probe for studying the active sites of these enzymes. Comparison of the present results with those previously obtained with Eschericha coli RNA polymerase in this laboratory suggest a new degree of structural homology between eucaryotic and procaryotic RNA polymerases. [less ▲]

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See detailThe inactive members of the aspartic proteinase family in the ruminant placenta: specificity of three different radioimmunoassay systems
Perenyi, Zsolt; Sulon, Joseph ULg; Szenci, Otto et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2001), 5(1), 26-27

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See detailInAs with wurtzite crystal structure: full-potential and psedopotential ab-initio calculations
Zanolli, Zeila ULg; von Barth, Ulf

in Luitz, Joachim; Hebert, Cecile; Weinmeier, Kerstin (Eds.) et al DFTEM2006 - bringing together two communities (2006)

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See detailInbreeding depression for global and partial economic indexes, production, type and functional traits in the Walloon Region of Belgium
Croquet, Coraline; Mayeres, Patrick; Gillon, Alain ULg et al

in INTERBULL Bulletin (2005), 33

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See detailInbreeding depression for global and partial economic indexes, production, type, and functional traits
Croquet, Coraline; Mayeres, Patrick; Gillon, Alain ULg et al

in Journal of Dairy Science (2006), 89(6), 2257-2267

The objective of this research was to examine the effects of inbreeding in the population of Holstein cattle in the Walloon region of Belgium. The effects of inbreeding on the global economic index and ... [more ▼]

The objective of this research was to examine the effects of inbreeding in the population of Holstein cattle in the Walloon region of Belgium. The effects of inbreeding on the global economic index and its components were studied by using data from the genetic evaluations of February 2004 for production, somatic cell score (SCS), computed from somatic cell counts and type. Inbreeding coefficients for 956,516 animals were computed using a method that allows assigning an inbreeding coefficient to individuals without known parents. These coefficients were equal to the mean inbreeding coefficient of contemporary individuals with known parents. The significance of inbreeding effects on the different evaluated traits and on the different indexes were tested using a t-test comparing estimated standard errors and effects. The inbreeding effect was significantly different from zero for the vast majority of evaluated traits and for all of the indexes. Inbreeding had the greatest deleterious effects on production traits. Inbreeding decreased yield of milk, fat, and protein during a lactation by 19.68, 0.96, and 0.69 kg, respectively, per each 1% increase in inbreeding. The regression coefficient of SCS per 1% increase in inbreeding was +0.005 SCS units. The inbreeding depression was thus relatively low for SCS, but inbred animals had higher SCS than non-inbred animals, indicating that inbred animals would be slightly more sensitive to mastitis than non-inbred animals. Estimates of inbreeding effects on evaluated type traits per 1% increase were small. The most strongly affected type traits were chest width, rear leg, and overall development on a standardized scale. For several type traits, particularly traits linked to the udder, the estimates suggested a favorable effect of inbreeding. The global economic index was depressed by around 6.13 Euro of lifetime profit per 1% increase in inbreeding for the Holstein animals in the Walloon region of Belgium. [less ▲]

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