85 resultados para ANTIMALARIALS


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A classic way of delaying drug resistance is to use an alternative when possible. We tested the malaria treatment Argemone mexicana decoction (AM), a validated self-prepared traditional medicine made with one widely available plant and safe across wide dose variations. In an attempt to reflect the real situation in the home-based management of malaria in a remote Malian village, 301 patients with presumed uncomplicated malaria (median age 5 years) were randomly assigned to receive AM or artesunate-amodiaquine [artemisinin combination therapy (ACT)] as first-line treatment. Both treatments were well tolerated. Over 28 days, second-line treatment was not required for 89% (95% CI 84.1-93.2) of patients on AM, versus 95% (95% CI 88.8-98.3) on ACT. Deterioration to severe malaria was 1.9% in both groups in children aged </=5 years (there were no cases in patients aged >5 years) and 0% had coma/convulsions. AM, now government-approved in Mali, could be tested as a first-line complement to standard modern drugs in high-transmission areas, in order to reduce the drug pressure for development of resistance to ACT, in the management of malaria. In view of the low rate of severe malaria and good tolerability, AM may also constitute a first-aid treatment when access to other antimalarials is delayed.

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Les recommandations en termes de prévention contre la malaria pour les pays à risques modéré à faible diffèrent entre les pays, malgré le fait que les personnes soient exposées à un risque identique dans les pays qu'ils visitent. Pour inclure les voyageurs dans la réflexion, des outils de partage de la décision ont été développés et testés dans cette population. Leur utilisation a montré que la majorité des personnes choisissent de ne pas prendre de chimioprophylaxie en avançant des raisons valides. Le développement d'aides décisionnelles répondant à des critères reconnus est prévu et permettra d'améliorer la pertinence des recommandations. Les aides décisionnelles permettront aussi aux voyageurs de faire un choix de prévention avec les soignants au plus près de leurs valeurs et préférences, tout en respectant les règles de l'éthique médicale. Recommendations for malaria prevention for travelers planning a trip in medium to low risk countries differ between countries, despite the fact that people are exposed to the same risk in the travelled country. Decision aids have been developed and tested in a population of travelers planning a trip in such countries n order to present travelers the various prevention options and involve them in the decision. The use of the decision aid showed that he majority of people choose not to take chemoprophylaxis and that they could motivate their choice with valid reasons. The development of decision aids based on recognized quality criteria is foreseen; these will allow to improving the relevance of the recommendations and enable travelers to choose a prevention option that will be the closest to their values and preferences while following to the principles of medical ethics.

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OBJECTIVE: To review the available knowledge on epidemiology and diagnoses of acute infections in children aged 2 to 59 months in primary care setting and develop an electronic algorithm for the Integrated Management of Childhood Illness to reach optimal clinical outcome and rational use of medicines. METHODS: A structured literature review in Medline, Embase and the Cochrane Database of Systematic Review (CDRS) looked for available estimations of diseases prevalence in outpatients aged 2-59 months, and for available evidence on i) accuracy of clinical predictors, and ii) performance of point-of-care tests for targeted diseases. A new algorithm for the management of childhood illness (ALMANACH) was designed based on evidence retrieved and results of a study on etiologies of fever in Tanzanian children outpatients. FINDINGS: The major changes in ALMANACH compared to IMCI (2008 version) are the following: i) assessment of 10 danger signs, ii) classification of non-severe children into febrile and non-febrile illness, the latter receiving no antibiotics, iii) classification of pneumonia based on a respiratory rate threshold of 50 assessed twice for febrile children 12-59 months; iv) malaria rapid diagnostic test performed for all febrile children. In the absence of identified source of fever at the end of the assessment, v) urine dipstick performed for febrile children <2 years to consider urinary tract infection, vi) classification of 'possible typhoid' for febrile children >2 years with abdominal tenderness; and lastly vii) classification of 'likely viral infection' in case of negative results. CONCLUSION: This smartphone-run algorithm based on new evidence and two point-of-care tests should improve the quality of care of <5 year children and lead to more rational use of antimicrobials.

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Quinine and quinidine are well-known 4-quinolinecarbinolamines that exhibit antimalarial activity, but, in contrast, their epimers 9-epiquinine and 9-epiquinidine are almost inactive. Literature data are conflicting in describing the 4-quinolinecarbinolamine interaction mode with the molecular target, the ferriprotoporphyrin IX [Fe(III)PPIX]. In the present paper, a pharmacophore is proposed based on the binding of the non-aromatic nitrogen to the iron atom. The 4-quinolinecarbinolamine antimalarials were superimposed on the pharmacophore under consideration and complexes with Fe(III)PPIX were constructed. Conformational analyses of the complexes were performed applying the MM+ molecular mechanics method. The analysis of the complexes showed that the proposed ligand mode is possible although it does not explain the activity differences between epimers. A discussion of the structural aspects is also provided.

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We have synthesized a series of dimers of (+)-(7R,11R)-huprine Y and evaluated their activity against Trypanosoma brucei, Plasmodium falciparum, rat myoblast L6 cells and human acetylcholinesterase (hAChE), and their brain permeability. Most dimers have more potent and selective trypanocidal activity than huprine Y and are brain permeable, but they are devoid of antimalarial activity and remain active against hAChE. Lead optimization will focus on identifying compounds with a more favourable trypanocidal/anticholinesterase activity ratio.

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We have synthesized a series of dimers of (+)-(7R,11R)-huprine Y and evaluated their activity against Trypanosoma brucei, Plasmodium falciparum, rat myoblast L6 cells and human acetylcholinesterase (hAChE), and their brain permeability. Most dimers have more potent and selective trypanocidal activity than huprine Y and are brain permeable, but they are devoid of antimalarial activity and remain active against hAChE. Lead optimization will focus on identifying compounds with a more favourable trypanocidal/anticholinesterase activity ratio.

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Vitamins are essential compounds mainly involved in acting as enzyme co-factors or in response to oxidative stress. In the last two years it became apparent that apicomplexan parasites are able to generate B vitamers such as vitamin B1 and B6 de novo. The biosynthesis pathways responsible for vitamin generation are considered as drug targets, since both provide a high degree of selectivity due to their absence in the human host. This report updates the current knowledge about vitamin B1 and B6 biosynthesis in malaria and other apicomplexan parasites. Owing to the urgent need for novel antimalarials, the significance of the biosynthesis and salvage of these vitamins is critically discussed in terms of parasite survival and their exploitation for drug development.

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Recycling nutrients form sanitary wastes back into agricultural ecosystems offers an option to alleviate soil depletion in regions where the use of mineral fertiliser is limited. Exemplary nutrient and water cycling approaches, including collection, treatment and use of human urine, are established at Valley View University (VVU) in Greater Accra, Ghana. Concerns have been recently raised in regard to fate and impact of pharmaceutical residues in soils and interlinked environment. To evaluate in how far emerging knowledge can be transposed onto VVU, urban and rural environments in Greater Accra, spatial disease occurrence and drug consumption patterns were studied. Malaria has been found to represent the most severe health burden in Ghana, but there is also a high prevalence of infectious diseases. Drugs consumed in great quantities and in respect to their residual loads potentially problematic in the environment belong to therapeutic groups of: antibiotics, analgesics, drugs for diabetes, antimalarials, cardiovascular drugs and anthelmintics. Drug consumption revealed to be highest in urban and lowest in rural areas. At VVU the range of consumed drugs is comparable to urban areas except for the negligible use of diabetes and cardiovascular medication as well as contraceptives.

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Resistant strains of Plasmodium falciparum and the unavailability of useful antimalarial vaccines reinforce the need to develop new efficacious antimalarials. This study details a pharmacophore model that has been used to identify a potent, soluble, orally bioavailable antimalarial bisquinoline, metaquine (N,N'-bis(7-chloroquinolin-4-yl)benzene-1,3-diamine) (dihydrochloride), which is active against Plasmodium berghei in vivo (oral ID50 of 25 mu mol/kg) and multidrug-resistant Plasmodium falciparum K1 in vitro (0.17 mu M). Metaquine shows strong affinity for the putative antimalarial receptor, heme at pH 7.4 in aqueous DMSO. Both crystallographic analyses and quantum mechanical calculations (HF/6-31+G*) reveal important regions of protonation and bonding thought to persist at parasitic vacuolar pH concordant with our receptor model. Formation of drug-heme adduct in solution was confirmed using high-resolution positive ion electrospray mass spectrometry. Metaquine showed strong binding with the receptor in a 1: 1 ratio (log K = 5.7 +/- 0.1) that was predicted by molecular mechanics calculations. This study illustrates a rational multidisciplinary approach for the development of new 4-aminoquinoline antimalarials, with efficacy superior to chloroquine, based on the use of a pharmacophore model.

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Theoretical calculations have been carried out on the interactions of several endoperoxides which are potential antimalarials, including the clinically useful artemisinin, with two possible sources of iron in the parasite, namely the hexa-aquo ferrous ion [Fe(H2O)(6)](2+) and haeme. DFT calculations show that the reactions of all endoperoxides considered, with both sources of iron, initially generate a Fe-O bond followed by cleavage of the O-O bond to oxygen radical species. Subsequently, they can be transformed into carbon-centred radicals of greater stability. However, with [Fe(H2O)(6)](2+) as the iron source, the oxygen-centred radical species are more likely to react further akin to Fenton's reagent, whereby iron salts encourage hydrogen peroxide to act as an oxidizing agent, and that solvent plays a major role. In contrast, when reacting with haeme, the oxygen-centred radicals interconvert to more stable carbon-centred radicals, which can then alkylate haeme. Subsequent cleavage of the Fe-O bond leads to stable and inactive antimalarial products. These results indicate that the reactivity of the endoperoxides as antimalarials is greater with iron hexahydrates for radical-mediated damage as opposed to haeme, which leads to unreactive species. Since only nanomolar quantities of hydrated metal ions could catalyse the reactions leading to damage to the parasites, this could be an alternative or competitive reaction responsible for the antimalarial activity. (c) 2005 Elsevier B.V. All rights reserved.

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Malaria, also popularly known as maleita , intermittent fever, paludism, impaludism, third fever or fourth fever, is an acute infectious febrile disease, which, in human beings, is caused by four species: Plasmodium falciparum, P. vivax, P. malariae and P. ovale. Malaria, one of the main infectious diseases in the world, is the most important parasitoses, with 250 million annual cases and more than 1 million deaths per year, mainly in children younger than live years of age. The prophylactic and therapeutic arsenal against malaria is quite restricted, since all the antimalarials currently in use have some limitation. Many plant species belonging to several families have been tested in vivo, using the murine experimental model Plasmodium berghei or in vitro against P. falciparum, and this search has been directed toward plants with antithermal, antimalarial or antiinflammatory properties used in popular Brazilian bolk medicine. Studies assessing the biological activity of medicinal plant essential oils have revealed activities of interest, such as insecticidal, spasmolytic and antiplasmodic action. It has also been scientifically established that around 60% of essential oils have antifungal properties and that 35% exhibit antibacterial properties. In our investigation, essential oils were obtained from the species Vanillosmopsis arborea, Lippia sidoides and Croton zethneri which are found in the bioregion of Araripe-Ceará. The chemical composition of these essential oils was partially characterized and the presence of monoterpenes and sesquiterpenes. The acute toxicity of these oils was assessed in healthy mice at different doses applied on a single day and on four consecutive days, and in vitro cytotoxicity in HeLa and Raw cell lines was determined at different concentrations. The in vivo tests obtained lethal dose values of 7,1 mg/Kg (doses administered on a single day) and 1,8 mg/Kg (doses administered over four days) for 50% of the animals. In the in vitro tests, the inhibitory concentration for 50% of cell growth in Hela cell lines was 588 μg/mL (essential oil from C. zethneri after 48 h), from 340-555 μg/mL (essential oil from L. sidoides, after 24 and 48 h). The essential oil from V. arborea showed no cytotoxicity and none of the essential oils were cytotoxic in Raw cell lines. These data suggest a moderate toxicity in the essential XVIII oils under study, a finding that does not impede their testing in in vivo antimalarial assays. Was shown the antimalarial activity of the essential oils in mice infected with P. berghei was assessed. The three species showed antimalarial activity from 36%-57% for the essential oil from the stem of V. arborea; from 32%-82% for the essential oil from the leaves of L. sidoides and from 40%-70% of reduction for the essential oil from the leaves of C. zethneri. This is the first study showing evidence of antimalarial activity with these species from northeast Brazil. Further studies to isolate the active ingredients of these oils are needed to determine if a single active ingredient accounts for the antimalarial activity or if a complex integration of all the compounds present occurs, a situation reflected in their biological activity

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Resistance of Plasmodium falciparum to the usual antimalarials, as well as their adverse effects and high cost, has led to the search of new drugs against malaria. Several of these have been developed from medicinal plants based on ethnopharmacology, including the most widely used antimalarials today: quinine and artemisinin. In the present study schizonticide activity of extracts and fractions of a number of medicinal plants from the Caatinga and Amazon biomes were assessed based on ethnopharmacological and chemosystematic information. These included Ximenia americana, Maytenus rigida, Sideroxylon obtusifolium, Stryphnodendro coriaceum, Bowdichia virgiliodes, Schinopis brasiliensis and Picrolemma sprucei, the last, an Amazon species. Antimalarial tests of blood schizonticides were conducted in Swiss mice infected with P. berghei and in vitro against P. falciparum. In vitro cytotoxicity studies were carried out using HeLa, CHO, 3T3, Raw and HEPG2 cell lines. Except for X. americana, all species exhibited in vivo or in vitro antimalarial activity, inhibiting parasitic growth by up to 79%. Extracts exhibited moderate toxicity with dosedependent kinetics. In this sense, ethnopharmacological and chemosystematic approaches were shown to be useful and promising tools in the search of new drugs. These findings represent a significant contribution to scientific knowledge of the antimalarial potential of Brazilian flora, thereby opening perspectives for the development of new antimalarials

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ObjectiveTo compare the demographic features, presenting manifestations, diagnostic investigations, disease course, and drug therapies of children with juvenile dermatomyositis (JDM) followed in Europe and Latin America.MethodsPatients were inception cohorts seen between 1980 and 2004 in 27 paediatric rheumatology centres. The following information was collected through the review of patient charts: sex; age at disease onset; date of disease onset and diagnosis; onset type; presenting clinical features; diagnostic investigations; course type; and medications received during disease course.ResultsFour hundred and ninety patients (65.5% females, mean onset age 7.0 years, mean disease duration 7.7 years) were included. Disease presentation was acute or insidious in 57.1% and 42.9% of the patients, respectively. The course type was monophasic in 41.3% of patients and chronic polycyclic or continuous in 58.6% of patients. The more common presenting manifestations were muscle weakness (84.9%), Gottron's papules (72.9%), heliotrope rash (62%), and malar rash (56.7%). Overall, the demographic and clinical features of the 2 continental cohorts were comparable. European patients received more frequently high-dose intravenous methylprednisolone, cyclosporine, cyclophosphamide, and azathioprine, while methotrexate and antimalarials medications were used more commonly by Latin American physicians.ConclusionThe demographic and clinical characteristics of JDM are similar in European and Latin American patients. We found, however, several differences in the use of medications between European and Latin American paediatric rheumatologists.

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The antimalarial properties of azomethine H represent the basis for its use as a chemotherapeutic agent. This work was carried out in order to verify the biological side effects of azomethine H and to clarify the contribution of reactive oxygen species (ROS) in this process. It was shown that azomethine H increased serum activities of amylase, alanine transaminase (ALT) and the TEARS concentrations, in rats. No changes were observed in glutathione peroxidase and catalase activities. The drug-induced tissue damage might be due to superoxide radicals (O-2(.-)), since Cu-Zn superoxide dismutase activities were increased by azomethine I-I treatment. This study allows tentative conclusions to be drawn regarding which reactive oxygen metabolites play a role in azomethine H activity. We concluded that (O-2(.-)) maybe produced as a mediator of azomethine H action.