Honey bee foraging is a complex behavior because it involves tens of thousands of organisms making decisions about where to collect pollen and nectar based on the quality of resources and the distance to flowers. Studying this aspect of their biology is possible through direct observations but the large number of individuals involved in this behavior makes the implementation of technologies ideal to scale up this type of study. Consequently, there is a need for instruments that can facilitate accurate assessments of honey bee foraging at the colony level.
View Article and Find Full Text PDFIntroduction: Chagas disease (CD) affects ~7 million people worldwide. Benznidazole (BZN) and nifurtimox (NFX) are the only approved drugs for CD chemotherapy. Although both drugs are highly effective in acute and paediatric infections, their efficacy in adults with chronic CD (CCD) is lower and variable.
View Article and Find Full Text PDFThe analysis techniques and the corresponding software suite (General Resource for Ionospheric Transient Investigations) are described. was used to develop the Dinsmore et al. [2] results, which found a novel classification of traveling ionospheric disturbances (TIDs) called semi-coherent ionospheric pulsing structures (SCIPS).
View Article and Find Full Text PDFWe investigated the in vitro activity and selectivity, and in vivo efficacy of ravuconazole (RAV) in self-nanoemulsifying delivery system (SNEDDS) against Trypanosoma cruzi. Novel formulations of this poorly soluble C14-α-demethylase inhibitor may improve its efficacy in the experimental treatment. In vitro activity was determined in infected cardiomyocytes and efficacy in vivo evaluated in terms of parasitological cure induced in Y and Colombian strains of T.
View Article and Find Full Text PDFIntroduction: Chagas disease treatment relies on the lengthy administration of benznidazole and/or nifurtimox, which have frequent toxicity associated. The disease, caused by the parasite , is mostly diagnosed at its chronic phase when life-threatening symptomatology manifest in approximately 30% of those infected. Considering that both available drugs have variable efficacy by then, and there are over 6 million people infected, there is a pressing need to find safer, more efficacious drugs.
View Article and Find Full Text PDFPosaconazole (POS) is an inhibitor of ergosterol biosynthesis in clinical use for treating invasive fungal infections. POS has potent and selective anti-Trypanosoma cruzi activity and has been evaluated as a possible treatment for Chagas disease. Microtissues are a 3D culture system that has been shown to reproduce better tissue architecture and functionality than cell cultures in monolayer (2D).
View Article and Find Full Text PDFIn the past 5-10 years, Venezuela has faced a severe economic crisis, precipitated by political instability and declining oil revenue. Public health provision has been affected particularly. In this Review, we assess the impact of Venezuela's health-care crisis on vector-borne diseases, and the spillover into neighbouring countries.
View Article and Find Full Text PDFObjectives: Leishmaniasis, one of the most significant neglected diseases around the world, is caused by protozoan parasites of the Leishmania genus. Nowadays, the available aetiological treatments for leishmaniasis have variable effectiveness and several problems such as serious side effects, toxicity, high cost and an increasing number of resistance cases. Thus, there is an urgent need for safe, oral and cost-effective drugs for leishmaniases.
View Article and Find Full Text PDFSelf-emulsifying drug delivery systems (SEDDSs) are lipid-based anhydrous formulations composed of an isotropic mixture of oil, surfactant, and cosurfactants usually presented in gelatin capsules. Ravuconazole (Biopharmaceutics Classification System [BCS] Class II) is a poorly water-soluble drug, and a SEDDS type IIIA was designed to deliver it in a predissolved state, improving dissolution in gastrointestinal fluids. After emulsification, the droplets had mean hydrodynamic diameters <250 nm, zeta potential values in the range of -45 mV to -57 mV, and showed no signs of ravuconazole precipitation.
View Article and Find Full Text PDFTwo brothers with congenitally-acquired Chagas' disease (CD) diagnosed during adulthood are reported. The patients were born in the USA to a mother from Bolivia who on subsequent assessment was found to be serologically positive for Trypanosoma cruzi. Serologic screening of all pregnant women who migrated from countries with endemic CD is strongly recommended.
View Article and Find Full Text PDFAntimicrob Agents Chemother
April 2015
We tested the antituberculosis drug SQ109, which is currently in advanced clinical trials for the treatment of drug-susceptible and drug-resistant tuberculosis, for its in vitro activity against the trypanosomatid parasite Trypanosoma cruzi, the causative agent of Chagas disease. SQ109 was found to be a potent inhibitor of the trypomastigote form of the parasite, with a 50% inhibitory concentration (IC50) for cell killing of 50 ± 8 nM, but it had little effect (50% effective concentration [EC50], ∼80 μM) in a red blood cell hemolysis assay. It also inhibited extracellular epimastigotes (IC50, 4.
View Article and Find Full Text PDFJ Eukaryot Microbiol
December 2015
Chagas disease, a chronic systemic parasitosis caused by the Kinetoplastid protozoon Trypanosoma cruzi, is the first cause of cardiac morbidity and mortality in poor rural and suburban areas of Latin America and the largest parasitic disease burden in the continent, now spreading worldwide due to international migrations. A recent change in the scientific paradigm on the pathogenesis of chronic Chagas disease has led to a consensus that all T. cruzi-seropositive patients should receive etiological treatment.
View Article and Find Full Text PDFTrypanosomatid parasites are the causative agents of many neglected tropical diseases and there is currently considerable interest in targeting endogenous sterol biosynthesis in these organisms as a route to the development of novel anti-infective drugs. Here, we report the first x-ray crystallographic structures of the enzyme squalene synthase (SQS) from a trypanosomatid parasite, Trypanosoma cruzi, the causative agent of Chagas disease. We obtained five structures of T.
View Article and Find Full Text PDFTrichomonas vaginalis causes trichomoniasis in humans, a sexually transmitted disease commonly treated with metronidazole (MTZ), a drug that presents some toxicity, causing undesirable side effects. In addition, an increase in metronidazole-resistant parasites has been reported. Thus, the development of alternative treatment is recommended.
View Article and Find Full Text PDFLeishmaniasis, caused by protozoan parasites of the Leishmania genus, is one of the most prevalent neglected tropical diseases. It is endemic in 98 countries, causing considerable morbidity and mortality. Pentavalent antimonials are the first line of treatment for leishmaniasis except in India.
View Article and Find Full Text PDFBackground: Current chemotherapy for Chagas disease is unsatisfactory due to its limited efficacy, particularly in the chronic phase, with frequent side effects that can lead to treatment discontinuation. Combined therapy is envisioned as an ideal approach since it may improve treatment efficacy whilst decreasing toxicity and the likelihood of resistance development. We evaluated the efficacy of posaconazole in combination with benznidazole on Trypanosoma cruzi infection in vivo.
View Article and Find Full Text PDFInt J Parasitol Drugs Drug Resist
December 2012
The protozoan parasite, Trypanosoma cruzi, causes the most prevalent parasitic infection in the American continent. It gives rise to life-long infection in humans and results in severe cardiomyopathy or other life-threatening manifestations (Chagas disease) in ~30% of those infected. Animal models and clinical studies indicate that etiological treatment of the infection reduces the risk of developing the disease manifestations.
View Article and Find Full Text PDFSterol biosynthesis inhibitors are promising entities for the treatment of trypanosomal diseases. Insect forms of Trypanosoma brucei, the causative agent of sleeping sickness, synthesize ergosterol and other 24-alkylated sterols, yet also incorporate cholesterol from the medium. While sterol function has been investigated by pharmacological manipulation of sterol biosynthesis, molecular mechanisms by which endogenous sterols influence cellular processes remain largely unknown in trypanosomes.
View Article and Find Full Text PDFThe antifungal posaconazole (PCZ) is the most advanced candidate for the treatment of Chagas disease, having potent anti-Trypanosoma cruzi activity in vitro and in animal models of the disease as well as an excellent safety profile in humans. Amiodarone (AMD) is the antiarrhythmic drug most frequently used for the symptomatic treatment of chronic Chagas disease patients, but it also has specific anti-T. cruzi activity.
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