In-situ polymerization of monoethylenically unsaturated monomers with secondary amines

Patent (2004)

The present invention relates to a new process for the preparation of well-defined homopolymers, random and block copolymers using a mixture of a hindered secondary amine and an oxidizing agent, without ... [more ▼]

The present invention relates to a new process for the preparation of well-defined homopolymers, random and block copolymers using a mixture of a hindered secondary amine and an oxidizing agent, without any additional free-radical initiator. [less ▲]

In-situ polymerization of monoethylenically unsaturated monomers with secondary amines

Patent (2004)

A process for the preparation of any of well-defined homopolymers, random and block copolymers is disclosed. The process that entails forming a mixture of monomers, a hindered secondary amine and an ... [more ▼]

A process for the preparation of any of well-defined homopolymers, random and block copolymers is disclosed. The process that entails forming a mixture of monomers, a hindered secondary amine and an oxidizing agent is characterized in the absence of any additional free-radical initiator. [less ▲]

In-situ SAXS of resorcinol-formaldehyde gel formation: either colloid aggregation or microphase separation

Poster (2008, October)

The in-vitro antimicrobial activity of some medicinal plants against beta-lactam-resistant bacteria

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 ▲]

IN-VITRO EVALUATION OF A-5021 ANTI-VIRAL ACTIVITY AGAINST TESTUDINID HERPESVIRUS 3 AND INITIAL PHARMACOKINETIC STUDY IN HERMANN'S TORTOISE (Testudo hermanni)

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 ▲]

In-vivo studies on Haemaccel-fibronectin interaction in man.

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 ▲]

Inactivated Bovine Herpesvirus 1 Induces Apoptotic Cell Death of Mitogen-Stimulated Bovine Peripheral Blood Mononuclear Cells

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 ▲]

Inactivation of alpha(2)-Macroglobulin by Activated Human Polymorphonuclear Leukocytes.

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 ▲]

Inactivation of E. coli RNA polymerase by pyridoxal 5′-phosphate: Identification of a low pKa lysine as the modified residue

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 ▲]

Inactivation 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.

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 ▲]