Research Interests:
Research Interests:
Research Interests:
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select... more
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Research Interests:
Research Interests:
ABSTRACT
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Abstract Experimental dipole moments of some disubstituted 9-acridanones were compared to the vectorially and theoretically calculated values using CNDO/2 method. Results supported the existence of a presumed folding of these compounds... more
Abstract Experimental dipole moments of some disubstituted 9-acridanones were compared to the vectorially and theoretically calculated values using CNDO/2 method. Results supported the existence of a presumed folding of these compounds with the prevalence of a quasi-equatorial conformation.
Research Interests:
The potential of human plasma (HP) or serum (HS) as a replacement for fetal calf serum (FCS) was evaluated in a liver infusion tryptose (LIT) medium for bulk cultivation of Leishmania donovani promastigotes. The promastigote yield with... more
The potential of human plasma (HP) or serum (HS) as a replacement for fetal calf serum (FCS) was evaluated in a liver infusion tryptose (LIT) medium for bulk cultivation of Leishmania donovani promastigotes. The promastigote yield with the LIT-FCS standard medium was 0.4–1.8×107 ml−1, and yields of 0.5–3.4×107 (P = 0.527) and 0.4–2.4×107 (P = 0.062) were recorded for two LIT medium variants containing HP or HS as supplement instead of FCS. Significantly, higher promastigote yields of 1.3–4.9×107 ml−1 were demonstrated when LIT medium was supplemented with HP of blood group O but not A, B, AB or equally pooled ABO (P = 0.007–0.020). Matching (P = 0.56) strong positive (1 : 10 2400 to ≥1 : 262 144 00) and weak negative (1 : 5–1 : 160) direct agglutination test (DAT) titres, respectively, were demonstrated in 24 visceral leishmaniasis (VL) and 45 non-VL sera for both standard LIT-FCS and alternative LIT-HP derived antigens. Our findings indicate strong potential for sustainable product...
Research Interests:
... We are greatly indebted to Professor Gasim Badri, president of the university, Professor Abubaker Uro, Mr. Mohamed el Mutasim and Mr. Hussam Ali Osman at ... 2003; 8:164-7. 7 ter Horst R, Tefera T, Assefa G, Ebrahim AZ, Davidson RN,... more
... We are greatly indebted to Professor Gasim Badri, president of the university, Professor Abubaker Uro, Mr. Mohamed el Mutasim and Mr. Hussam Ali Osman at ... 2003; 8:164-7. 7 ter Horst R, Tefera T, Assefa G, Ebrahim AZ, Davidson RN, Ritmeijer K. Field evaluation of rK39 test ...
Research Interests:
Efflux mechanisms protect bacterial cells by pumping out toxic compounds and actively contribute to bacterial multidrug resistance. Agents inhibiting efflux pumps are of interest for the control of multidrug-resistant bacterial... more
Efflux mechanisms protect bacterial cells by pumping out toxic compounds and actively contribute to bacterial multidrug resistance. Agents inhibiting efflux pumps are of interest for the control of multidrug-resistant bacterial infections. Herein we report the effects of new chloroquinoline derivatives that render resistant Enterobacter aerogenes isolates noticeably more susceptible to structurally unrelated antibiotics. In addition, some of these chloroquinolines increase the intracellular concentration of chloramphenicol. Some of the molecules tested in this work are able to inhibit the main efflux pump (AcrAB-TolC), which is involved in E. aerogenes antibiotic resistance.
Research Interests: Medical Microbiology, Biology, Medicine, Antibiotic Resistance, Multidrug Resistance, and 12 moreDrug Resistance, Bacteria, Membrane transport, Enterobacter aerogenes, Anti-Bacterial Agents, Antimicrobial agents, Microbial Sensitivity Tests, Efflux Pumps, Quinolines, Bacterial Infection, Chloramphenicol, and Pharmacology and pharmaceutical sciences
This study was designed to test the hypothesis that lipophilic cationic drugs with only roughly similar structures mediate the reversal of multidrug-resistance (MDR) by interacting with membrane phospholipids. The permeation properties of... more
This study was designed to test the hypothesis that lipophilic cationic drugs with only roughly similar structures mediate the reversal of multidrug-resistance (MDR) by interacting with membrane phospholipids. The permeation properties of MDR-modulators and non-modulators were studied by quantifying their ability to induce the leakage of Sulphan blue through the membrane of negatively charged unilamellar liposomes. Of the 22 compounds under investigation, only those bearing a net positive electric charge per molecule (z) ≥0.2 induced dye leakage. All these efficient drugs are well-known MDR-modulators: calcium-channel blockers (propranolol, verapamil, diltiazem and dipyridamole), calmodulin antagonists (clomipramine and thioridazine) and antiparasitic agents (mepacrine, thioacridine derivatives and quinine). The non-modulators tested, including antineoplasic agents and steroids, did not induce any membrane permeation. The permeation process was a co-operative one (1.1 < Hill coefficient < 4.1) and the permeation doses inducing 50% dye leakage (PD50) were 1.9–11.2 mm. The permeation ability of the MDR-modulators (log(1/PD50)) increased significantly with octanol-buffer distributions per unit net electric charge ((logD)/z). The results provide evidence that a complex interplay occurs between the electric charge and the lipophilicity of the MDR-modulators when a dye leakage is induced through model membranes, and probably also when the MDR is reversed in leukaemic cells.
Research Interests:
After several decades of continuously successful antibiotic therapy against bacterial infections, we are now facing a worrying prospect: the accelerated evolution of antibiotic resistance to important human pathogens and the scarcity of... more
After several decades of continuously successful antibiotic therapy against bacterial infections, we are now facing a worrying prospect: the accelerated evolution of antibiotic resistance to important human pathogens and the scarcity of new anti-infective drug families under ...
Research Interests: Microbiology, Medical Microbiology, Biology, Medicine, Antibiotic Resistance, and 15 moreBacterial resistance, Resistance, Membrane transport, Antimicrobial chemotherapy, Spectrum, Gram-negative bacteria, Anti-Bacterial Agents, Efflux Pumps, Quinolines, Structure activity Relationship, Bacterial Infection, Molecular Dynamic Simulation, Efflux pump inhibitors, Pharmacology and pharmaceutical sciences, and Antibiotic Therapy
Enterobacter aerogenes, one of the most frequently isolated nosocomial pathogens in France, is exhibiting increasing multidrug resistance mechanisms associated with a change in membrane permeability. For drugs of the quinolone family,... more
Enterobacter aerogenes, one of the most frequently isolated nosocomial pathogens in France, is exhibiting increasing multidrug resistance mechanisms associated with a change in membrane permeability. For drugs of the quinolone family, mutations in the target and active efflux play a prominent role in the resistance. We report here the effect of several pyridoquinoline derivatives that restore a noticeable fluoroquinolone accumulation to resistant strains that overexpress the MarA activator. Studies of the energy-dependent quinolone efflux indicate that the most efficient derivatives tested probably inhibit the resistance process by acting as substrate competitors on the pump extruding intracellular norfloxacin.
Research Interests: Thermodynamics, Chemistry, Organic Chemistry, Medicinal Chemistry, Medicine, and 13 moreResistance, Bacteria, Enterobacter aerogenes, Medicinal, Microbial Sensitivity Tests, Efflux Pumps, Quinolines, Structure activity Relationship, Drug Interaction, Chemical Synthesis, DNA binding proteins, Norfloxacin, and Pharmacology and pharmaceutical sciences
This article seeks to elucidate effects of early-life influences on later-life tuberculosis outcomes using a dynamic computer simulation model. To illustrate the value of such a model, three research questions are considered: 1) If we... more
This article seeks to elucidate effects of early-life influences on later-life tuberculosis outcomes using a dynamic computer simulation model. To illustrate the value of such a model, three research questions are considered: 1) If we implemented an intervention ...
Research Interests:
In Enterobacter aerogenes and Klebsiella pneumoniae, efflux provides efficient extrusion of antibiotics and contributes to the multidrug resistance phenotype. One of the alkoxyquinoline derivatives studied here,... more
In Enterobacter aerogenes and Klebsiella pneumoniae, efflux provides efficient extrusion of antibiotics and contributes to the multidrug resistance phenotype. One of the alkoxyquinoline derivatives studied here, 2,8-dimethyl-4-(2′-pyrrolidinoethyl)-oxyquinoline, restores noticeable drug susceptibility to resistant clinical strains. Analyses of energy-dependent chloramphenicol efflux indicate that this compound inhibits the efflux pump mechanism and improves the activity of structurally unrelated antibiotics on multidrug-resistant E. aerogenes and K. pneumoniae isolates.
Research Interests:
Research Interests:
Research Interests:
Research Interests: Immunology, Medicine, Sudan, Humans, Animals, and 12 moreVisceral Leishmaniasis, Endemic Diseases, Diagnostic Test, Sensitivity and Specificity, Lymph Node, Enzyme Linked Immunosorbent Assay, immunoglobulin G, Case Control Studies, Statistics as Topic, Rural Population, reducing agents, and Direct agglutination test
The multiple resistance to treatment, acquired by bacteria and malignant tumours requires to find alternatives to the existing medicines and treatment procedures. One of them is strengthening the effects of cytostatics by modifying their... more
The multiple resistance to treatment, acquired by bacteria and malignant tumours requires to find alternatives to the existing medicines and treatment procedures. One of them is strengthening the effects of cytostatics by modifying their molecular structures through exposure to laser radiation. A method associated with this is the generation of micro-droplets which contain medicines solutions; the droplets are vectors to
Research Interests:
Research Interests:
Research Interests: Laser Spectroscopy, Medical Microbiology, Biology, Medicine, Antibiotic Resistance, and 15 moreHumans, Bacteria, Membrane transport, Enterobacter aerogenes, Antimicrobial agents, Functional Group, Microbial Sensitivity Tests, Efflux Pumps, Biological activity, Chloramphenicol, Antibiotic Susceptibility, Fluoroquinolones, Klebsiella pneumoniae, Efflux pump inhibitors, and Drug synergism
Copyright © 1999-2010 John Wiley & Sons, Inc. All Rights Reserved.
Research Interests:
There is a substantial body of evidence highlighting the importance of the social determinants of health in shaping the health of urban populations in Canada. The low socio-economic status of marginalized, disadvantaged, and precarious... more
There is a substantial body of evidence highlighting the importance of the social determinants of health in shaping the health of urban populations in Canada. The low socio-economic status of marginalized, disadvantaged, and precarious populations in urban settings has been linked to adverse health outcomes including chronic and infectious disease, negative health behaviours, barriers to accessing health care services, and overall mortality. Given the dynamic complexities and inter-relationships surrounding the underlying drivers of population health outcomes and inequities, it is difficult to assess program and policy intervention tradeoffs, particularly when such interventions are studied with static models. To address this challenge, we have adopted a systems science approach and developed a simulation model for the City of Toronto, Canada, utilizing system dynamics modelling methodology. The model simulates changes in health, social determinants, and disparities from 2006 and projects forward to 2046 under different assumptions. Most of the variables in the model are stratified by ethnicity, immigration status, and gender, and capture the characteristics of adults aged 25-64. Intervention areas include health care access, behaviour, income, housing, and social cohesion. The model simulates alternative scenarios to help demonstrate the relative impact of different interventions on poor health outcomes such as chronic disease rates, disability rates, and mortality rate. It gives insight into how much, and how quickly, interventions can reduce mortality and morbidity. We believe this will serve as a useful learning tool to allow diverse stakeholders and policy makers to ask "what if" questions and map effective policy directions for complex population health problems, and will enable communities to think about their health futures.
Research Interests: Sociology, Anthropology, Health Promotion, Social Determinants of Health, System Dynamics Modeling, and 15 moreCommunity Health, Modeling and Simulation, Medicine, Health Systems, Canada, Cities, Humans, Computer Simulation, Female, Male, Middle Aged, Adult, Public health systems and services research, Community Health Planning, and Socioeconomic Factors
ABSTRACT