Search results for "malaria"
showing 10 items of 169 documents
Prenylated Flavonoids from the Roots of Tephrosia rhodesica
2020
Five new compounds—rhodimer (1), rhodiflavan A (2), rhodiflavan B (3), rhodiflavan C (4), and rhodacarpin (5)—along with 16 known secondary metabolites, were isolated from the CH2Cl2–CH3OH (1:1) extract of the roots of Tephrosia rhodesica. They were identified by NMR spectroscopic, mass spectrometric, X-ray crystallographic, and ECD spectroscopic analyses. The crude extract and the isolated compounds 2–5, 9, 15, and 21 showed activity (100% at 10 μg and IC50 = 5–15 μM) against the chloroquine-sensitive (3D7) strain of Plasmodium falciparum. peerReviewed
Clinical recrudescence of chronic untreated P. malariae infection after BNT162b2 CoVID-19 vaccine
2022
We described a case of clinical reactivation of chronic P. malariae infection following CoVID-19 vaccination with BNT162b2 (Pifzer-Biontech CoVID-19 vaccine) in a 48-year old Italian man.The patient came to our attention for fever of unknown origin show a quartan pattern (every third day) associated to splenomegaly, the onset of the fever occurred one month after CoVID-19 vaccination with BNT162b2. P. malariae was diagnosed using CarestartTM malaria rapid test and Polymerase-Chain Reaction. Post-vaccine transient reduction of immune reactivity is described in literature, although the mechanism is unknown.(c) 2022 Published by Elsevier Ltd.CC_BY_NC_ND_4.0
Experimental inhibition of nitric oxide increases Plasmodium relictum (lineage SGS1) parasitaemia.
2012
7 pages; International audience; Malaria is a widespread vector-borne disease infecting a wide range of terrestrial vertebrates including reptiles, birds and mammals. In addition to being one of the most deadly infectious diseases for humans, malaria is a threat to wildlife. The host immune system represents the main defence against malaria parasites. Identifying the immune effectors involved in malaria resistance has therefore become a major focus of research. However, this has mostly involved humans and animal models (rodents) and how the immune system regulates malaria progression in non-model organisms has been largely ignored. The aim of the present study was to investigate the role of…
Immunity, resistance and tolerance in bird-parasite interactions.
2013
12 pages; International audience; Interacting pathogens and hosts have evolved reciprocal adaptations whose function is to allow host exploitation (from the pathogen stand point) or minimize the cost of infection (from the host stand point). Once infected, two strategies are offered to the host: parasite clearing (resistance) or withstanding the infection while paying a low fitness cost (tolerance). In both cases, the immune system plays a central role. Interestingly, whatever the defence strategy adopted by the host, this is likely to have an effect on parasite evolution. Given their short generation time and large population size, parasites are expected to rapidly adapt to the environment…
Hijacking the human complement inhibitor C4b-binding protein by the sporozoite stage of the Plasmodium falciparum parasite
2022
We thank Anna Blom for donating the C4bpα CCP1-2 expression plasmid (pET26-CCP1-2). The following reagent was obtained through BEI Resources, NIAID, NIH: Plasmid pDS56-32/RBSII-CS27IVC-6XHis, MRA-272, contributed by Photini Sinnis. The complement system is considered the first line of defense against pathogens. Hijacking complement regulators from blood is a common evasion tactic of pathogens to inhibit complement activation on their surfaces. Here, we report hijacking of the complement C4b-binding protein (C4bp), the regulator of the classical and lectin pathways of complement activation, by the sporozoite (SPZ) stage of the Plasmodium falciparum parasite. This was shown by direct binding …
Multi-output Model with Box-Jenkins Operators of Quadratic Indices for Prediction of Malaria and Cancer Inhibitors Targeting Ubiquitin- Proteasome Pa…
2016
The ubiquitin-proteasome pathway (UPP) is the primary degradation system of short-lived regulatory proteins. Cellular processes such as the cell cycle, signal transduction, gene expression, DNA repair and apoptosis are regulated by this UPP and dysfunctions in this system have important implications in the development of cancer, neurodegenerative, cardiac and other human pathologies. UPP seems also to be very important in the function of eukaryote cells of the human parasites like Plasmodium falciparum, the causal agent of the neglected disease Malaria. Hence, the UPP could be considered as an attractive target for the development of compounds with Anti-Malarial or Anti-cancer properties. R…
Application of molecular topology to the prediction of potency and selection of novel insecticides active against malaria vectors
2005
Abstract A study on the basis of molecular topology has been carried out to predict the potency of insecticides active against malaria vectors (Culex) as well as to select novel compounds potentially active on those vectors. The results, performed over two sets of compounds, namely hormone-like and ‘common’ or wide-spectra insecticides, demonstrate that the adequate combination of topological charge indices and simple topological-geometric indices, yield very good results in both, the prediction of potency and the selection of new insecticides. Further development should be addressed in the future; however, the achievement described here is extremely encouraging.
Aplicación de la topología molecular a la predicción de la actividad antimalárica de análogos de la 4-anilinoquinolina
2021
La malaria es una enfermedad parasitaria causada por protozoos del género Plasmodium y transmitida por vectores del género Anopheles . En 2019 esta enfermedad se cobró la vida de más de 400.000 personas, de las cuales un 94 % se concentraban en la región de África. Uno de los principales problemas en el control de la malaria es la aparición de resistencias frente a los diferentes fármacos que existen, es por ello que es necesario el desarrollo de alternativas antimaláricas eficaces. En este estudio se ha aplicado la topología molecular a una serie de compuestos análogos de la 4-anilinoquinolina con actividad inhibitoria de la proliferación de 3 cepas de Plasmodium falciparum, una sensibl…
New active drugs against liver stages of Plasmodium predicted by molecular topology.
2008
ABSTRACT We conducted a quantitative structure-activity relationship (QSAR) study based on a database of 127 compounds previously tested against the liver stage of Plasmodium yoelii in order to develop a model capable of predicting the in vitro antimalarial activities of new compounds. Topological indices were used as structural descriptors, and their relation to antimalarial activity was determined by using linear discriminant analysis. A topological model consisting of two discriminant functions was created. The first function discriminated between active and inactive compounds, and the second identified the most active among the active compounds. The model was then applied sequentially t…
Biowaiver monographs for immediate release solid oral dosage forms: quinidine sulfate.
2009
Literature data are reviewed relevant to the decision to allow a waiver of in vivo bioequivalence (BE) testing for the approval of new multisource and reformulated immediate release (IR) solid oral dosage forms containing quinidine sulfate. Quinidine sulfate's solubility and permeability, its therapeutic use and index, pharmacokinetics, excipient interactions and reported BE/bioavailability (BA) problems were taken into consideration. The available data are not fully conclusive, but do suggest that quinidine sulfate is highly soluble and moderately to highly permeable and would likely be assigned to BCS Class I (or at worst BCS III). In view of the inconclusiveness of the data and, more imp…