258 research outputs found

    More than a Hundred Years in the Search for an Accurate Diagnosis for Chagas Disease: Current Panorama and Expectations

    Get PDF
    Chagas disease, or American trypanosomiasis, is a parasitic disease of the Americas. In nature, Trypanosoma cruzi is transmitted through various species of triatomine bugs. However, non-vectorial transmission can also occur, such as transmission through blood products or by transplanting infected organs, by vertical transmission, and lately by oral route. Currently, Chagas disease affects approximately 6–7 million people worldwide, and the process of urbanization in Latin America and migratory movements from endemic countries have led to Chagas disease being diagnosed in areas where the infection is not endemic. There are several methods for diagnosing Chagas disease. Some of these are mostly used for research purposes, while others are used in routine diagnostic laboratories. According to the World Health Organization (WHO), chronic Chagas disease diagnosis is based on two serological techniques. To establish a definitive diagnosis, the results must be concordant. In the case of discordances, the WHO proposes repeating serology in a new sample, and if results remain inconclusive, a confirmatory test should be performed. This chapter shows aspects of the diagnosis of Chagas disease, which varies in its sensitivity and specificity, and its use depends on the geographical location, the available resources, and the purpose of the diagnosis

    Biochemical, Cellular, and Immunologic Aspects during Early Interaction between Trypanosoma cruzi and Host Cell

    Get PDF
    The close parasite-host relationship involves different aspects such as the biochemical, physiological, morphological, and immunological adaptations. Studies on parasite-host interaction have provided a myriad of information about its biology and have established the building blocks for the development of new drug therapies to control the parasite. Several mechanisms for the parasite invasion have been proposed through in vivo or in vitro experimental data. Since the first histological studies until the studies on the function/structure of the involved molecules, this complex interaction has been roughly depicted. However, new recent strategies as genetic and proteomic approaches have tuned knowledge on how the host reacts to the parasite and how the parasite avoids these host’s reactions in order to survive

    InCense IoT: A Collective Sensing System for Behavior Data in Shared Spaces

    Get PDF
    Behavioral sensing systems collect data from smartphones, wearables, and other devices with the aim of analyzing and making sense of them. In this work, we present InCense IoT, a collective sensing system which uses mobile and ubiquitous sensors for collecting behavior data of groups of participants in shared spaces. This paper describes the concept of collective sensing, an implementation onto InCense called InCense IoT, innovative features, advantages over individual-centric sensing systems. Finally, this paper presents results of a use case using it in monitoring behaviors in mother-child interactions

    Metabarcoding and Digital PCR (dPCR): Application in the Study of Neglected Tropical Diseases

    Get PDF
    neglected tropical diseases such as Chagas disease, dengue, Zika, chikungunya, and malaria cause millions of deaths each year and they are caused by a variety of pathogens whose diagnosis is very limited or subject to conventional testing, making a treatment less accessible, accurate and timely diagnosis for choosing their treatments. Traditional methods for pathogen detection have not been able to meet the growing need for diagnosis and control. The incorporation of new technologies such as next-generation sequencing (NGS) and digital PCR (dPCR) represent a better diagnostic possibility due to their ability to absolutely quantify pathogens with high selectivity and precision. Our planet is currently experiencing environmental changes of an unprecedented magnitude and rate, including climate change, globalized pollution, biodiversity loss, and land use changes, so neglected diseases require a comprehensive understanding of the ecology of vectors in the different eco-epidemiological contexts, as well as of the transmission cycles of pathogens and their transmission dynamics. In this sense, NGS and dPCR open a new panorama for a better understanding of these diseases with the aim of proposing new programs for their care

    In vitro trypanocidal activity of nitroimidazole derivatives

    Get PDF
    Chagas' disease, caused by the protozoan parasite Trypanosoma cruzi, affects 9-12 million of people in Latin America and it is an important cause of heart disease. Although transmission has been reduced, an effective therapy for the infected population is lacking. New isomers nitroimidazole derivatives [4(5)-bromo-1-phenacyl-5(4)-nitroimidazoles] were developed and their antichagasic properties were studied. Five compounds (with different substituents in their aromatic ring) displayed remarkable in vitro activities against T. cruzi. The results demonstrated that 4(5)-bromo-1-(4-methoxiphenacyl)-2-methyl-5(4)- nitroimidazole, 4(5)-bromo-1-(4-chlorophenacyl)-2-methyl-5(4)-nitroimidazole, and 4(5)-bromo-1-(4- cianophenacyl)-2-methyl-5(4)-nitroimidazole have IC50 values of of 3.95, 2.3, and 1.15 ÎŒg/mL, respectively, and show acceptable values of cytotoxicity, at concentrations below 5 ÎŒg/mL. Our results indicate that mixtures of isomers are a potent inhibitor of T. cruzi growth. The present evidence shows very promising results of new isomers, which emerge as strong candidates for further tests as anti-T. cruzi agents.Colegio de FarmacĂ©uticos de la Provincia de Buenos Aire

    Asexual reproduction: an alternative for the propagation and conservation of papaya (Carica papaya L.) native to Guerrero, Mexico

    Get PDF
    Objective: To evaluate the effect on the rooting of Carica papaya L. cuttings using three different substrates and varying the length of the vegetative material Design / methodology / approach: A completely randomized design with a 2 × 3 factorial arrangement was used. Herbaceous cuttings of 30 and 40 cm in length were collected in March 2018, from lateral branches from native papaya plants (Carica papaya L.) from various regions of the state of Guerrero. The stakes were placed in different substrates: 1) sand, 2) Peat Moss¼ and 3) a mixture of sand and Peat Moss¼ (70:30, v / v). Sixty days after sowing, the rooting percentage, root length, plant height, stem diameter, number of leaves, crown diameter, weight of fresh biomass, weight of dry biomass, fresh weight of root and root dry weight. With the data obtained, an analysis of variances and a mean comparison test (Tukey, p?0.05) were performed. Results: The 40 and 30 cm long cuttings showed 60 and 50% rooting, respectively, being those plants where 40 cm cuttings were used, consistently taller, with a greater number of leaves, crown diameter and greater length of root. Of the three substrates used, sand was the best for the rooting of papaya cuttings, since in it plants with significantly higher fresh biomass weight were developed (p?0.05). Study limitations / implications: It is important to continue the study into the flowering and fruiting stages. Findings / conclusions: The proposed protocol allows the rooting of papaya cuttingsObjective: Evaluate the effect of three types of substrate and different shoot lengths onthe rooting of Carica papaya L. shoots.Design/ methodology/ approach: This experiment followed a completely randomizeddesign with a 2×3 factorial arrangement. Shoots of 30 and 40 cm of length werecollected in March 2018 from the lateral branches of papaya plants (Carica papaya L.)native to various regions of Guerrero. Shoots were placed in different substrates: 1)sand, 2) Peat Moss¼, and 3) sand and Peat Moss¼ mixture (70:30, v/v). Sixty days afterplanting, rooting percentage, root length, plant height, stem diameter, number of leaves,crown diameter, biomass fresh weight, biomass dry weight, root fresh weight, and rootdry weight were evaluated. Data were analyzed through an analysis of variance and amean difference test (Tukey, p?0.05).Results: The rooting of 40- and 30-cm shoots was 60 and 50%, respectively. Plantswith the highest height, number of leaves, root length, and crown diameter derived from 240-cm shoots. Sand was the best substrate for rooting, where plants with higher freshbiomass were significantly developed.Study limitations/ implications: Continue study during the flowering and fruitingstages.Findings/ conclusions: This protocol allows the rooting of papaya shoots

    Naturally p-hydroxybenzoylated lignins in palms

    Get PDF
    The industrial production of palm oil concurrently generates a substantial amount of empty fruit bunch (EFB) fibers that could be used as a feedstock in a lignocellulose-based biorefinery. Lignin byproducts generated by this process may offer opportunities for the isolation of value-added products, such as p-hydroxybenzoate (pBz), to help offset operating costs. Analysis of the EFB lignin by nuclear magnetic resonance (NMR) spectroscopy clearly revealed the presence of bound acetate and pBz, with saponification revealing that 1.1 wt% of the EFB was pBz; with a lignin content of 22.7 %, 4.8 % of the lignin is pBz that can be obtained as a pure component for use as a chemical feedstock. Analysis of EFB lignin by NMR and derivatization followed by reductive cleavage (DFRC) showed that pBz selectively acylates the Îł-hydroxyl group of S units. This selectivity suggests that pBz, analogously with acetate in kenaf, p-coumarate in grasses, and ferulate in a transgenic poplar augmented with a feruloyl-CoA monolignol transferase (FMT), is incorporated into the growing lignin chain via its Îł-p-hydroxybenzoylated monolignol conjugate. Involvement of such conjugates in palm lignification is proven by the observation of novel p-hydroxybenzoylated non-resinol ÎČ–ÎČ-coupled units in the lignins. Together, the data implicate the existence of p-hydroxybenzoyl-CoA:monolignol transferases that are involved in lignification in the various willows (Salix spp.), poplars and aspen (Populus spp., family Salicaceae), and palms (family Arecaceae) that have p-hydroxybenzoylated lignins. Even without enhancing the levels by breeding or genetic engineering, current palm oil EFB ‘wastes’ should be able to generate a sizeable stream of p-hydroxybenzoic acid that offers opportunities for the development of value-added products derived from the oil palm industry

    Biorational and conventional insecticides efficacy to control thrips (Frankliniella occidentalis Perg.) on strawberries (Fragaria x ananassa Duch.) at Morelos state, Mexico: Spanish

    Get PDF
    Strawberry cultivation presents multiple phytosanitary limitations among which the “western flower thrips” stands out. Adults and nymphs of F. occidentalis produce severe damage to flowers and fruits, reducing the yield and quality of the product. In Mexico, thrips control is based on the use of synthetic chemical insecticides. The objective of this research was to evaluate the insecticidal effectiveness of biorational and conventional products as control alternatives and their phytotoxic effects in strawberry cultivation. The study was carried out in strawberry cv. Camino Real in flowering stage - fruiting established in open ground. A completely randomized design with seven treatments and four replications was used. Significant differences between treatments could be identified; Imidacloprid + Lambda Cyhalothrin and Bifenthrin caused the highest mortality of thrips with an efficiency of 92 and 93% respectively. Spinosad obtained good results, ranking as the second best option with 90% control efficiencies; neem extract stood out as an excellent biorational pest management alternative with 77% control efficacy in the last evaluation. No phytotoxic effects were observed from any of the treatments on the crop.Objective: To evaluate the insecticidal effectiveness of biorational and conventional products as alternatives to control thrips and their phytotoxic effects in strawberry cultivation. Design / methodology / approach: The research was carried out in strawberry cv. Camino Real during its flowering stage - fruiting established in open ground; A completely randomized experimental design with seven treatments and four replications was used. The treatments evaluated were: T1: neem oil extract, T2: paraffin oil, T3: garlic extract + hot chili pepper + cinnamon, T4: spinosad, T5: imidacloprid + lambda cyhalothrin, T6: bifenthrin, and T7: control. Applications were made weekly and the mortality evaluation was carried out by counting the number of live thrips per flower. With the obtained data, an analysis of variances and a mean comparison test (Tukey, p ≀ 0.05) were performed. Results: Significant differences between treatments could be identified (p ≀ 0.05); imidacloprid + lambda cyhalothrin and bifenthrin caused the highest mortality of thrips with 92 and 93 % efficacy, respectively. Spinosad obtained good results, ranking as the second-best option with 90 % control efficiencies; neem extract stood out as an excellent biorational pest management alternative with 77 % control efficacy in its last evaluation. No phytotoxic effects were observed from any of the treatments on the crop. Limitations on study / implications: It is important to continue the study in the laboratory to obtain the LD50 and LD90 of the management alternatives, as well as an MRL analysis of the molecules used. Findings / conclusions: The proposed protocol evidenced the efficacy of biorational and ecological thrips control treatments in intensive horticultural systems
    • 

    corecore