35 research outputs found
Second-generation nitazoxanide derivatives: thiazolides are effective inhibitors of the influenza A virus
Aim: The only small molecule drugs currently available for treatment of influenza A virus (IAV) are M2 ion channel blockers and sialidase inhibitors. The prototype thiazolide, nitazoxanide, has successfully completed Phase III clinical trials against acute uncomplicated influenza. Results: We report the activity of seventeen thiazolide analogs against A/PuertoRico/8/1934(H1N1), a laboratory-adapted strain of the H1N1 subtype of IAV, in a cell culture-based assay. A total of eight analogs showed IC50s in the range of 0.14–5.0 μM. Additionally a quantitative structure–property relationship study showed high correlation between experimental and predicted activity based on a molecular descriptor set. Conclusion: A range of thiazolides show useful activity against an H1N1 strain of IAV. Further evaluation of these molecules as potential new small molecule therapies is justified
Chloroquine-Resistant Haplotype Plasmodium falciparum Parasites, Haiti
Chloroquine resistance is now present in this country
Mitochondrial physiology
As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery
Mitochondrial physiology
As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery
Aleuroclava aucubae (Aleyrodidae) nouveau pour la France, et Parlatoria oleae (Diaspididae) nouveau pour la Corse (Hemiptera)
National audienceTwo Hemiptera are newly recorded from Corsica: Aleuroclava aucubae (Kuwana) (Aleyrodidae) on Citrus sp. and Parlatoria oleae (Colvée) (Diaspididae) on Prunus domestica L.Deux Hémiptères nouveaux pour la Corse sont signalés, Aleuroclava aucubae (Kuwana) (Aleyrodidae) sur Citrus sp. et Parlaroria oleae (Colvée) (Diaspididae) sur Prunus domestica L
Influence of cropping system on Fusarium head blight and mycotoxin levels in winter wheat
In this study, we investigated the effects of various wheat cropping systems on Fusarium head blight severity and mycotoxin (deoxynivalenol, nivalenol, zearalenone) levels. We investigated four wheat-cropping systems: a conventional system, an integrated system, a direct drilling system and an organic system, in fields with natural contamination. The study was carried out over three 1-year periods: 1999–2000, 2000–2001 and 2001–2002. The severity of Fusarium head blight and toxin levels differed considerably between years, reflecting climatic effects. In a given year, the severity of Fusarium head blight also differed between cropping systems, with the most severe disease observed in the direct drilling and conventional system plots in 2000. The level of grain contamination by mycotoxins therefore depends on both climate and cropping system. Mycotoxin levels were highest in the year with the highest disease severity: 2000. Contamination levels were highest with the direct drilling system. We were unable to rank the organic and conventional systems, because neither was consistently more contaminated than the other. Moreover, no clear relationship was found between disease severity and levels of contamination with deoxynivalenol, nivalenol or zearalenone underconditions of natural contamination
Effects of nitazoxanide on pharmacokinetics and pharmacodynamics of a single dose of warfarin
Antiviral thiazolides inhibit paramyxovirus replication by targeting the Fusion protein folding: role of glycoprotein-specific disulfide isomerase ERp57
Nitazoxanide Inhibits Paramyxovirus Replication by Targeting the Fusion Protein Folding: Role of Glycoprotein-Specific Thiol Oxidoreductase ERp57
Paramyxoviridae, a large family of enveloped viruses harboring a nonsegmented negative-sense RNA genome, include important human pathogens as measles, mumps, respiratory syncytial virus (RSV), parainfluenza viruses, and henipaviruses, which cause some of the deadliest emerging zoonoses. There is no effective antiviral chemotherapy for most of these pathogens. Paramyxoviruses evolved a sophisticated membrane-fusion machine consisting of receptor-binding proteins and the fusion F-protein, critical for virus infectivity. Herein we identify the antiprotozoal/antimicrobial nitazoxanide as a potential anti-paramyxovirus drug targeting the F-protein. We show that nitazoxanide and its circulating-metabolite tizoxanide act at post-entry level by provoking Sendai virus and RSV F-protein aggregate formation, halting F-trafficking to the host plasma membrane. F-protein folding depends on ER-resident glycoprotein-specific thiol-oxidoreductase ERp57 for correct disulfide-bond architecture. We found that tizoxanide behaves as an ERp57 non-competitive inhibitor; the putative drug binding-site was located at the ERp57-b/b′ non-catalytic domains interface. ERp57-silencing mimicked thiazolide-induced F-protein alterations, suggesting an important role of this foldase in thiazolides anti-paramyxovirus activity. Nitazoxanide is used in the clinic as a safe and effective antiprotozoal/antimicrobial drug; its antiviral activity was shown in patients infected with hepatitis-C virus, rotavirus and influenza viruses. Our results now suggest that nitazoxanide may be effective also against paramyxovirus infection