Publications

TitleAbstractYear
Filter
PMID(sorted descending)
Filter
incessant left ventricular tachycardia of unusual etiology.apart from coronary artery disease, left ventricular tachycardia may result from cardiac sarcoidosis, left ventricular tumor, chagas disease and idiopathic left ventricular tachycardia. we report a rare case of incessant left ventricular tachycardia resulting from left dominant arrhythmogenic cardiomyopathy.201727788994
resveratrol reverses functional chagas heart disease in mice.chronic chagasic cardiomyopathy (ccc) develops years after acute infection by trypanosoma cruzi and does not improve after trypanocidal therapy, despite reduction of parasite burden. during disease, the heart undergoes oxidative stress, a potential causative factor for arrhythmias and contractile dysfunction. here we tested whether antioxidants/ cardioprotective drugs could improve cardiac function in established chagas heart disease. we chose a model that resembles b1-b2 stage of human ccc, tre ...201627788262
hypoxia-activated cytotoxicity of benznidazole against clonogenic tumor cells.solid tumors contain numerous regions with insufficient oxygen concentrations, a condition termed hypoxia. tumor hypoxia is significantly associated with metastasis, refractory to conventional cancer therapies, and poor patient survival. therefore, eradication of hypoxic tumor cells will likely have significant impact on the overall progression-free patient survival. this article reports a new discovery that benznidazole, a bioreductive drug currently used to treat chagas disease caused by the p ...201627786593
timing of pharyngeal swallow events in chagas' disease.esophageal involvement by chagas' disease causes a significative decrease in the number of neurons of the esophageal myenteric plexus, causing an impairment of esophageal motility with the same alterations described in primary esophageal achalasia. there is also a longer duration of pharyngeal transit, which might be consequent of the involvement of the central control of swallowing by the disease, or an adaptation of the pharynx to the difficult bolus transit through the esophagus, which could ...201427785276
variability of oral and pharyngeal transit between two consecutive swallows in chagas' disease.chagas' disease causes dysphagia, regurgitation and retention of food in the esophageal body. patients have longer pharyngeal clearance, which might be consequent of the involvement of the central nervous system or an adaptation to the esophageal transit impairment. if there is central nervous system involvement by the disease, we expect a larger difference in the oral and pharyngeal phases of swallowing between two consecutive swallows than that seen in controls. our objective was to evaluate t ...201327785241
the widespread anti-protozoal action of hiv aspartic peptidase inhibitors: focus on plasmodium spp., leishmania spp. and trypanosoma cruzi.the introduction of the hiv aspartic peptidase inhibitors has revolutionized the medical arena, since they have drastically reduced the number and the severity of opportunistic infections, including the protozoal diseases that afflict the hiv-infected individuals worldwide. hiv-pis rapidly and profoundly diminish the viral load, which is paralleled by increase in the cd4+ t lymphocyte counts and stimulation of the survival and activation of neutrophil, monocyte and endothelial cells, culminating ...201627784256
clear shot at primary aim: susceptibility of trypanosoma cruzi organelles, structures and molecular targets to drug treatment.chagas disease, caused by trypanosoma cruzi, stands out due to its socio- economic effects on low-income tropical populations. this disease affects millions of people worldwide. the current chemotherapy for it is based on benznidazole (bz) and nifurtimox (nif) and is unsatisfactory. in this review, we will focus on the search for potential target organelles and molecules for the chemotherapy of chagas disease. we consider as potential target organelles those that are absent or significantly diff ...201627784255
targets and patented drugs for chemotherapy of chagas disease in the last 15 years-period.the american trypanosomiasis, chagas disease, is a parasitic infection typically spread by triatomine vectors affecting millions of people all over latin america. existing chemotherapy is centered on the nitroaromatic compounds benznidazole and nifurtimox that provide unsatisfactory results and substantial side effects. so, the finding and exploration of novel ways to challenge this neglected disease is a main priority.201627784230
participation of tlr2 and tlr4 in cytokines production by patients with symptomatic and asymptomatic chronic chagas disease.chagas disease (cd), caused by the protozoan trypanosoma cruzi, is a serious public health issue. its evolution involves an acute stage, characterized by no specific symptoms, and the chronic stage during most individuals are asymptomatic, but about 30-40% of them become symptomatic presenting the cardiac or digestive disease. host immune response mechanisms involved in symptomatic or asymptomatic chronic disease are not fully understood. the pro-inflammatory cytokines are crucial in host resist ...201727783847
nicotinamide mononucleotide adenylyltransferase of trypanosoma cruzi (tcnmnat): a cytosol protein target for serine kinases.nicotinamide/nicotinate adenine dinucleotide (nad+/naad) performs essential functions in cell metabolism and energy production due to its redox properties. the nicotinamide/nicotinate mononucleotide adenylyltransferase (nmnat, ec 2.7.7.1/18) enzyme catalyses the key step in the biosynthesis of nad+. previously, the enzyme nmnat was identified in trypanosoma cruzi (tcnmnat), a pathogenic agent with epidemiological importance in latin america. to continue with the functional characterisation of th ...201627783719
biophysical characterization of alanine aminotransferase from trypanosoma cruzi.aminotransferases are an important group of enzymes that catalyze the transfer of an amino group of an amino acid into a keto acid. alanine aminotransferase from trypanosoma cruzi (tcalat) was cloned, overexpressed and purified. far-uv circular dichroism (cd), dynamic light scattering (dls), analytical size exclusion chromatography (asec) and small angle x-ray scattering (saxs) provide data concerning tcalat biophysical behavior. cd analysis displayed a typical spectrum of α-β proteins analogous ...201627781954
epidemiology of american tegumentary leishmaniasis and trypanosoma cruzi infection in the northwestern argentina.background. endemic areas of tegumentary leishmaniasis (tl) in salta, argentina, present some overlap zones with the geographical distribution of chagas disease, with mixed infection cases being often detected. objectives. the purpose of this study was to determine the magnitude of leishmania sp. infection and potential associated risk factors, the serologic prevalence of t. cruzi, and the presence of t. cruzi-leishmania sp. mixed infection in a region of the northwest of argentina. methods. cro ...201627777950
the potential of secondary metabolites from plants as drugs or leads against protozoan neglected diseases-part iii: in-silico molecular docking investigations.malaria, leishmaniasis, chagas disease, and human african trypanosomiasis continue to cause considerable suffering and death in developing countries. current treatment options for these parasitic protozoal diseases generally have severe side effects, may be ineffective or unavailable, and resistance is emerging. there is a constant need to discover new chemotherapeutic agents for these parasitic infections, and natural products continue to serve as a potential source. this review presents molecu ...201627775577
overcoming research barriers in chagas disease-designing effective implementation science.chagas disease is a complex tropical parasitic infection. it affects a significant portion of the population in latin america, especially in areas of poverty and poor access to health care. it also affects immigrants in high-income countries who lack access to health care due to their legal status. millions of people are at risk of contracting the disease, and approximately 30 % of chronically infected patients will develop cardiomyopathy. the cost of caring for patients that have been infected ...201727771804
pre-exposure to faeces or saliva of triatoma dimidiata decreases parasitemia in mice challenged with trypanosoma cruzi: a description of the inflammatory reaction at the inoculation siteunder natural conditions, trypanosoma cruzi infection is transmitted to mammals when faeces contaminated with metacyclic trypomastigotes gain access through skin lesions, mucosa or bite wounds. natural infection of bugs with t. cruzi can vary greatly from less than 1% up to 70%, depending on triatomine species: in the case of triatoma dimidiata, the percentage of infection is around 30%. in this work uses biological fluids (saliva and faeces) from triatoma dimidiata to inoculate experimental ani ...201627770761
effects of a novel β-lapachone derivative on trypanosoma cruzi: parasite death involving apoptosis, autophagy and necrosis.natural products comprise valuable sources for new antiparasitic drugs. here we tested the effects of a novel β-lapachone derivative on trypanosoma cruzi parasite survival and proliferation and used microscopy and cytometry techniques to approach the mechanism(s) underlying parasite death. the selectivity index determination indicate that the compound trypanocidal activity was over ten-fold more cytotoxic to epimastigotes than to macrophages or splenocytes. scanning electron microscopy analysis ...201627770751
identification of novel trypanosoma cruzi prolyl oligopeptidase inhibitors by structure-based virtual screening.we have previously demonstrated that the secreted prolyl oligopeptidase of trypanosoma cruzi (poptc80) is involved in the infection process by facilitating parasite migration through the extracellular matrix. we have built a 3d structural model where poptc80 is formed by a catalytic α/β-hydrolase domain and a β-propeller domain, and in which the substrate docks at the inter-domain interface, suggesting a "jaw opening" gating access mechanism. this preliminary model was refined by molecular dynam ...201627770305
cardioprotective actions of curcumin on the pathogenic nfat/cox-2/prostaglandin e2 pathway induced during trypanosoma cruzi infection.diverse cardiovascular signaling routes have been considered critical for chagas cardiomyopathy caused by the protozoan parasite trypanosoma cruzi. along this line, t. cruzi infection and endothelin-1 (et-1) have been shown to cooperatively activate the ca(2+)/nfat cascade in cardiomyocytes, leading to cyclooxygenase type 2 (cox-2) induction and increased release of prostanoids and prohypertrophic peptides.201627765359
sirt1-pgc1α-nfκb pathway of oxidative and inflammatory stress during trypanosoma cruzi infection: benefits of sirt1-targeted therapy in improving heart function in chagas disease.chronic chagasic cardiomyopathy (ccm) is presented by increased oxidative/inflammatory stress and decreased mitochondrial bioenergetics. sirt1 senses the redox changes and integrates mitochondrial metabolism and inflammation; and sirt1 deficiency may be a major determinant in ccm. to test this, c57bl/6 mice were infected with trypanosoma cruzi (tc), treated with sirt1 agonists (resveratrol or srt1720), and monitored during chronic phase (~150 days post-infection). resveratrol treatment was parti ...201627764247
the role of the trypanosoma cruzi tcnrbd1 protein in translation.the regulation of gene expression in trypanosomatids occurs mainly at the post-transcriptional level. despite the importance of this type of control in trypanosoma cruzi, few rna binding proteins have been characterized. the rrm domain (rna recognition motif) is one of the most abundant domains found in rna-binding proteins in higher eukaryotes. proteins containing the rrm domain are involved in the majority of post-transcriptional processes regulating gene expression. in this work, we aimed to ...201627760165
triatoma maculata colonises urban domicilies in boa vista, roraima, brazil.during a medical entomology course in boa vista, roraima, colonies of triatoma maculata closely associated with pigeon nests were observed in concrete air-conditioner box located on the external plastered and cemented walls of a modern brick-built apartment block. in only one eight-hole ceramic brick, located inside one air-conditioner box, 127 specimens of t. maculata were collected. t. maculata is a recognised vector of trypanosoma cruzi in the surrounding area and its domiciliation increases ...201627759767
a simple, biologically sound, and potentially useful working classification of chagas disease vectors.current working classifications of chagas disease vectors rely on a loose mix-up of biological and operational matters. they are therefore confusing and ineffective. i propose a very simple classification that makes biological sense and can be operationally useful. it considers a four-level hierarchy of species (which can be native or non-native); populations (either wild or non-wild); infestation foci (natural, domestic or peridomestic); and individual bugs (which can be solitary house-invaders ...201627759764
heterochromatin base pair composition and diversification in holocentric chromosomes of kissing bugs (hemiptera, reduviidae).the subfamily triatominae (hemiptera, reduviidae) includes 150 species of blood-sucking insects, vectors of chagas disease or american trypanosomiasis. karyotypic information reveals a striking stability in the number of autosomes. however, this group shows substantial variability in genome size, the amount and distribution of c-heterochromatin, and the chromosome positions of 45s rdna clusters. here, we analysed the karyotypes of 41 species from six different genera with c-fluorescence banding ...201627759763
evolution of chagas' disease in brazil. epidemiological perspective and challenges for the future: a critical review.this article aimed to provide a critical review of the evolution of chagas' disease (chd) in brazil, its magnitude, historical development and management, and challenges for the future.201627758973
expression of profilin in trypanosoma cruzi and identification of some of its ligands.the role and regulation of actin in trypanosoma cruzi and other related parasites is largely unknown. based on early genome analysis, it was proposed that there was a reduced dependency on the acto-myosin system in the trypanosomatid parasites. however, more recent studies have extended the set of potential actin regulatory proteins, particularly for t. cruzi. one of the identified actin-binding proteins in trypanosomatids is profilin. in other systems, it is capable of simultaneously binding bo ...201627756617
relationships between altitude, triatomine (triatoma dimidiata) immune response and virulence of trypanosoma cruzi, the causal agent of chagas' disease.little is known about how the virulence of a human pathogen varies in the environment it shares with its vector. this study focused on whether the virulence of trypanosoma cruzi (trypanosomatida: trypanosomatidae), the causal agent of chagas' disease, is related to altitude. accordingly, triatoma dimidiata (hemiptera: reduviidae) specimens were collected at three different altitudes (300, 700 and 1400 m a.s.l.) in chiapas, mexico. the parasite was then isolated to infect uninfected t. dimidiata ...201727753118
determination of the ribosome structure to a resolution of 2.5 å by single-particle cryo-em.with the advance of new instruments and algorithms, and the accumulation of experience over decades, single-particle cryo-em has become a pivotal part of structural biology. recently, we determined the structure of a eukaryotic ribosome at 2.5 å for the large subunit. the ribosome was derived from trypanosoma cruzi, the protozoan pathogen of chagas disease. the high-resolution density map allowed us to discern a large number of unprecedented details including rrna modifications, water molecules, ...201727750394
nitroheterocyclic drugs cure experimental trypanosoma cruzi infections more effectively in the chronic stage than in the acute stage.the insect-transmitted protozoan parasite trypanosoma cruzi is the causative agent of chagas disease, and infects 5-8 million people in latin america. chagas disease is characterised by an acute phase, which is partially resolved by the immune system, but then develops as a chronic life-long infection. there is a consensus that the front-line drugs benznidazole and nifurtimox are more effective against the acute stage in both clinical and experimental settings. however, confirmative studies have ...201627748443
chemotherapeutic efficacy of phosphodiesterase inhibitors in chagasic cardiomyopathy.chagasic cardiomyopathy (ccm) caused by trypanosoma cruzi (tc) infection is prevalent in latin america and recognized as an emerging infectious heart disease in the us. the no-cgmp-pkg1α pathway maintains cardiac homeostasis and inotropy and may be disturbed due to phosphodiesterase (pde5) mediated cgmp catabolism in ccm.201627747306
identification of potential inhibitor and enzyme-inhibitor complex on trypanothione reductase to control chagas disease.chagas is a parasitic disease with major threat to public health due to its resistance against commonly available drugs. trypanothione reductase (tryr) is the key enzyme to develop this disease. though this enzyme is well thought-out as potential drug target, the accurate structure of enzyme-inhibitor complex is required to design a potential inhibitor which is less available for tryr. in this research, we aimed to investigate the advanced drug over the available existing drugs by designing inhi ...201627744094
cysteine mutagenesis improves the production without abrogating antigenicity of a recombinant protein vaccine candidate for human chagas disease.a therapeutic vaccine for human chagas disease is under development by the sabin vaccine institute product development partnership. the aim of the vaccine is to significantly reduce the parasite burden of trypanosoma cruzi in humans, either as a standalone product or in combination with conventional chemotherapy. vaccination of mice with tc24 formulated with monophosphoryl-lipid a (mpla) adjuvant results in a th1 skewed immune response with elevated igg2a and ifnγ levels and a statistically sign ...201727737611
synthesis of xylitan derivatives and preliminary evaluation of in vitro trypanocidal activity.a series of novel xylitan derivatives derived from xylitol were synthesized using operationally simple procedures. a xylitan acetonide was the key intermediate used to prepare benzoate, arylsulfonate esters and 1,2,3-triazole derivatives of xylitan. these compounds were evaluated for their in vitro anti-trypanosoma cruzi activity against trypomastigote and amastigote forms of the parasite in t. cruzi-infected cell lineages. benznidazole was used as positive control against t. cruzi and cytotoxic ...201627735872
new approaches to overcome transport related drug resistance in trypanosomatid parasites.leishmania and trypanosoma are members of the trypanosomatidae family that cause severe human infections such as leishmaniasis, chagas disease, and sleeping sickness affecting millions of people worldwide. despite efforts to eradicate them, migrations are expanding these infections to developing countries. there are no vaccines available and current treatments depend only on chemotherapy. drug resistance is a major obstacle for the treatment of these diseases given that existing drugs are old an ...201627733833
identification of the critical residues responsible for differential reactivation of the triosephosphate isomerases of two trypanosomes.the reactivation of triosephosphate isomerase (tim) from unfolded monomers induced by guanidine hydrochloride involves different amino acids of its sequence in different stages of protein refolding. we describe a systematic mutagenesis method to find critical residues for certain physico-chemical properties of a protein. the two similar tims of trypanosoma brucei and trypanosoma cruzi have different reactivation velocities and efficiencies. we used a small number of chimeric enzymes, additive mu ...201627733588
differential inflammasome activation signatures following intracellular infection of human macrophages with mycobacterium bovis bcg or trypanosoma cruzi.pathogens frequently exploit or evade inflammasome activation in order to survive and proliferate. alternatively, inadequate inflammasome activation by attenuated microorganisms or adjuvanted subunit vaccines may contribute to poor longevity of protection. to further understand these pathways, we determined the differential inflammasome transcriptome of human thp monocyte-derived macrophages in response to mycobacterium bovis bcg, as compared to lps or trypanosoma cruzi. the results identify the ...201627733245
dantrolene improves in vitro structural changes induced by serum from trypanosoma cruzi-infected mice.dystrophin, an important protein of the dystrophin-glycoprotein complex, has been implicated in the pathogenesis of experimental chagas disease. it is important for the maintenance of cell shape and contraction force transmission. dystrophin loss has been related to end-stage cardiac myopathies and proposed as a common route for myocardial dysfunction and progression to advanced heart failure. evidence suggests that calpains, calcium-dependent proteases, digest dystrophin when the calcium concen ...201727730362
evaluation of parameters impacting drug susceptibility in intracellular trypanosoma cruzi assay protocols.in order to understand the key parameters influencing drug susceptibility, different trypanosoma cruzi assay protocols were evaluated using a comparative assay design. the assays compared in this study were an image-based intracellular t. cruzi assay quantified through an image-mining algorithm and an intracellular assay utilizing a β-galactosidase-expressing t. cruzi strain. thirty-one reference compounds known to exhibit activities against intracellular t. cruzi were used as benchmarks. initia ...201727729503
pentamidine antagonizes the benznidazole's effect in vitro, and lacks of synergy in vivo: implications about the polyamine transport as an anti-trypanosoma cruzi target.benznidazole is the first-line drug used in treating chagas disease, which is caused by the parasite trypanosoma cruzi (t. cruzi). however, benznidazole has limited efficacy and several adverse reactions. pentamidine is an antiprotozoal drug used in the treatment of leishmaniasis and african trypanosomiasis. in t. cruzi, pentamidine blocks the transport of putrescine, a precursor of trypanothione, which constitutes an essential molecule in the resistance of t. cruzi to benznidazole. in the prese ...201627729250
parasites.parasites are an important cause of human disease worldwide. the clinical severity and outcome of parasitic disease is often dependent on the immune status of the host. specific parasitic diseases discussed in this chapter are amebiasis, giardiasis, cryptosporidiosis, cyclosporiasis, cystoisosporiasis, microsporidosis, granulomatous amebic encephalitis, toxoplasmosis, leishmaniasis, chagas disease, malaria, babesiosis, strongyloidiasis, and scabies.201627726821
ultrastructural and physiological changes induced by different stress conditions on the human parasite trypanosoma cruzi.trypanosoma cruzi is the etiological agent of chagas disease. the life cycle of this protozoan parasite is digenetic because it alternates its different developmental forms through two hosts, a vector insect and a vertebrate host. as a result, the parasites are exposed to sudden and drastic environmental changes causing cellular stress. the stress response to some types of stress has been studied in t. cruzi, mainly at the molecular level; however, data about ultrastructure and physiological sta ...201727714535
synthetic medicinal chemistry in chagas' disease: compounds at the final stage of "hit-to-lead" phase.chagas' disease, or american trypanosomosiasis, has been the most relevant illness produced by protozoa in latin america. synthetic medicinal chemistry efforts have provided an extensive number of chemodiverse hits at the "active-to-hit" stage. however, only a more limited number of these have been studied in vivo in models of chagas' disease. herein, we survey some of the cantidates able to surpass the "hit-to-lead" stage discussing their limitations or merit to enter in clinical trials in the ...201027713281
epitope capsid-incorporation: new effective approach for vaccine development for chagas disease.previously we reported that a hexon-modified adenovirus (ad) vector containing the invasive neutralizing epitope of trypanosoma cruzi (t. cruzi) trypomastigote gp83 (ad5-gp83) provided immunoprotection against t. cruzi infection. the purpose of this work was to design an improved vaccine for t. cruzi using a novel epitope capsid incorporation strategy. thus, we evaluated the immunoprotection raised by co-immunization with ad5-gp83 and an ad vector containing an epitope (asp-m) of the t. cruzi am ...201727709126
molecular characterization of 5s ribosomal rna genes and transcripts in the protozoan parasite leishmania major.eukaryotic 5s rrna, synthesized by rna polymerase iii (pol iii), is an essential component of the large ribosomal subunit. most organisms contain hundreds of 5s rrna genes organized into tandem arrays. however, the genome of the protozoan parasite leishmania major contains only 11 copies of the 5s rrna gene, which are interspersed and associated with other pol iii-transcribed genes. here we report that, in general, the number and order of the 5s rrna genes is conserved between different species ...201627707420
spermatogenesis in nesotriatoma bruneri (usinger 1944) (hemiptera, triatominae).the nesotriatoma genus consists of the species n. flavida n. bruneri and n. obscura, forming the flavida complex. variation in the size and morphological differences intraspecific of n. flavida led to the description of n. bruneri. two years later, the same author proposed the synonymization of n. bruneri with n. flavida. only in 1981 the specific status n. bruneri was recovered by means of morphological analysis of the genitalia. however, recently by genetic analysis, it was suggested that n. b ...201627706579
early and late assessment of esophagocardioplasty in the surgical treatment of advanced recurrent megaesophagus.since chagas disease has esophageal manifestations with different degrees of involvement, the best surgical option is controversial, especially for patients with advanced chagasic megaesophagus and recurrent symptoms after previous treatment.201727706452
[strategy for determining a baseline in areas of vector interruption for chagas disease].objectives present a strategy to determine the baseline in endemic areas in the process of vector interruption for chagas disease (chd). methods a social and environmental questionnaire and an entomological survey evaluated the physical conditions of dwellings, the inhabitants' knowledge of chd, the entomological triatomine indicators and the statistical relationship among these variables. results colonization and natural infection with trypanosoma cruzi exist in rhodnius prolixus, the principal ...201627706434
combined analysis of cross-reacting antibodies anti-β1ar and anti-b13 in advanced stages of chagas heart disease.autoantibodies cross-reacting with the β1 adrenergic receptor (anti-β1ar and anti-p2β) and cardiac myosin antigens (anti-b13) have been related to the pathogenesis of chronic chagas heart disease (cchd). studies exploring their levels in different stages are scarce. we aimed to evaluate the relationship of these autoantibodies with the clinical profile of chronic patients, especially regarding their classificatory accuracy in severe presentation with heart failure.201627699992
macrophages promote oxidative metabolism to drive nitric oxide generation in response to trypanosoma cruzi.trypanosoma cruzi is the causative agent of chronic chagasic cardiomyopathy. why macrophages (mφs), the early responders to infection, fail to achieve parasite clearance is not known. mouse (raw 264.7) and human (thp-1 and primary) mφs were infected for 3 h and 18 h with t. cruzi tci isolates, sylviox10/4 (syl, virulent) and tcc (nonpathogenic), which represent mφ stimulation and infection states, respectively. mφs incubated with lipopolysaccharide and gamma interferon (lps/ifn-γ) and with inter ...201627698021
lipid metabolism in rhodnius prolixus: lessons from the genome.the kissing bug rhodnius prolixus is both an important vector of chagas' disease and an interesting model for investigation into the field of physiology, including lipid metabolism. the publication of this insect genome will bring a huge amount of new molecular biology data to be used in future experiments. although this work represents a promising scenario, a preliminary analysis of the sequence data is necessary to identify and annotate the genes involved in lipid metabolism. here, we used bio ...201727697616
virus-like particle display of the α-gal epitope for the diagnostic assessment of chagas disease.the α-gal antigen [galα(1,3)galβ(1,4)glcnacα] is an immunodominant epitope displayed by infective trypomastigote forms of trypanosoma cruzi, the causative agent of chagas disease. a virus-like particle displaying a high density of α-gal was found to be a superior reagent for the elisa-based serological diagnosis of chagas disease and the assessment of treatment effectiveness. a panel of sera from patients chronically infected with t. cruzi, both untreated and benznidazole-treated, was compared w ...201627696820
th17 cells are more protective than th1 cells against the intracellular parasite trypanosoma cruzi.th17 cells are a subset of cd4+ t cells known to play a central role in the pathogenesis of many autoimmune diseases, as well as in the defense against some extracellular bacteria and fungi. however, th17 cells are not believed to have a significant function against intracellular infections. in contrast to this paradigm, we have discovered that th17 cells provide robust protection against trypanosoma cruzi, the intracellular protozoan parasite that causes chagas disease. th17 cells confer signif ...201627695083
chagas disease prevalence in pregnant women: migration and risk of congenital transmission.argentina has been a preferential target for bolivian immigrants for decades. the relatively recent migratory flux includes germany, france, the united states, australia, japan, and some latin american countries. the aim of this cross-sectional study was to describe the prevalence of chagas disease in pregnant women, analyzing the bolivian-specific chagas prevalence as the main contributor of migratory populations from chagas disease-endemic areas to buenos aires city, argentina, and to evaluate ...201627694720
hepatic injury associated with trypanosoma cruzi infection is attenuated by treatment with 15-deoxy-δ(12,14) prostaglandin j2.trypanosoma cruzi, the etiological agent of chagas' disease, causes an intense inflammatory response in several tissues, including the liver. since this organ is central to metabolism, its infection may be reflected in the outcome of the disease. 15-deoxy-δ(12,14) prostaglandin j2 (15dpgj2), a natural agonist of peroxisome-proliferator activated receptor (ppar) γ, has been shown to exert anti-inflammatory effects in the heart upon t. cruzi infection. however, its role in the restoration of liver ...201627693222
doxycycline and benznidazole reduce the profile of th1, th2, and th17 chemokines and chemokine receptors in cardiac tissue from chronic trypanosoma cruzi-infected dogs.chemokines (cks) and chemokine receptors (ckr) promote leukocyte recruitment into cardiac tissue infected by the trypanosoma cruzi. this study investigated the long-term treatment with subantimicrobial doses of doxycycline (dox) in association, or not, with benznidazole (bz) on the expression of ck and ckr in cardiac tissue. thirty mongrel dogs were infected, or not, with the berenice-78 strain of t. cruzi and grouped according their treatments: (i) two months after infection, dox (50 mg/kg) 2x/ ...201727688600
novel 2-arylazoimidazole derivatives as inhibitors of trypanosoma cruzi proliferation: synthesis and evaluation of their biological activity.in this work, the synthesis of a series of 2-arylazoimidazole derivatives 6-20 has been achieved through the reaction of imidazole with aryldiazonium salts, followed by ultrasound-assisted alkylation. this approach has important advantages including higher yield, shorter reaction times and milder reaction conditions. the structures of the compounds obtained were determined by ms, ir; and (1)h and (13)c nmr. the anti-trypanosoma cruzi activity of the 15 compounds obtained was evaluated. two compo ...201727688187
role of placental barrier integrity in infection by trypanosoma cruzi.american trypanosomiasis has long been a neglected disease endemic in latinamerica, but congenital transmission has now spread chagas disease to cause a global health problem. as the early stages of the infection of placental tissue and the vertical transmission by trypanosoma cruzi are still not well understood, it is important to investigate the relevance of the first structure of the placental barrier in chorionic villi infection by t. cruzi during the initial stage of the infection. explants ...201627686961
editorial commentary: targeting chagas disease. 201727686273
specific endocytosis blockade of trypanosoma cruzi exposed to a poly-lacnac binding lectin suggests that lectin-sugar interactions participate to receptor-mediated endocytosis.trypanosoma cruzi is a protozoan parasite transmitted by a triatomine insect, and causing human chagas disease in south america. this parasite undergoes a complex life cycle alternating between non-proliferative and dividing forms. owing to their high energy requirement, replicative epimastigotes of the insect midgut display high endocytic activity. this activity is mainly restricted to the cytostome, by which the cargo is taken up and sorted through the endosomal vesicular network to be deliver ...201727685262
natural products as a source for antileishmanial and antitrypanosomal agents.natural products are compounds extracted from plants, marine organisms, fungi or bacteria. many researches for new drugs are based on these natural molecules, mainly by beneficial effects on health, health, efficacy, and therapeutic safety. leishmaniosis, chagas disease and african sleeping sickness are neglected diseases caused by the leishmania and trypanosoma ssp. parasites. these infections mainly affect population of developing countries; they have different symptoms, and may often lead to ...201627682867
demographic effects of deltamethrin resistance in the chagas disease vector triatoma infestans.triatoma infestans (heteroptera: reduviidae) klug is the main vector of chagas disease in latin america. resistance to deltamethrin was reported in argentina and recently associated with reproductive and longevity trade-offs. the objectives of the present study were to describe the demographic consequences of deltamethrin resistance in t. infestans and to establish possible target stages for chemical control in susceptible and resistant colonies. a stage-classified matrix model was constructed b ...201627677531
quantitative pcr and unconventional serological methods to evaluate clomipramine treatment effectiveness in experimental trypanosoma cruzi infection.clomipramine (clo), a tricyclic antidepressant drug, has been used for the treatment of mice infected with trypanosoma cruzi. in this work we evaluated the effectiveness of clo treatment upon t. cruzi-infected mice in the chronic phase of the experimental infection using quantitative polymerase chain reaction (qpcr) and recombinant elisa. sixty swiss albino mice were inoculated with 50 trypomastigote forms of t. cruzi (tulahuen strain). clo treatment consisted of 5mg/kg/day during 60days by intr ...201627677396
the detection of trypanosoma cruzi by nested-pcr in elderly patients: relationship to the clinical and epidemiological profile.chagas disease, which is caused by trypanosoma cruzi, is transmitted primarily by triatomine bugs, although the incidence of new cases has decreased as a result of vector control. in brazil, most of those affected have the chronic form of the disease and are generally elderly individuals who require appropriate clinical follow-up. in this work, we undertook a descriptive study in which 85 patients were interviewed and blood samples were collected for molecular analyses based on the amplification ...201627666187
dynamic flux of microvesicles modulate parasite-host cell interaction of trypanosoma cruzi in eukaryotic cells.extracellular vesicles released from pathogens may alter host cell functions. we previously demonstrated the involvement of host cell-derived microvesicles (mvs) during early interaction between trypanosoma cruzi metacyclic trypomastigote (meta) stage and thp-1 cells. here, we aim to understand the contribution of different parasite stages and their extracellular vesicles in the interaction with host cells. first, we observed that infective host cell-derived trypomastigote (tissue culture-derive ...201727665486
in silico structural characterization of protein targets for drug development against trypanosoma cruzi.trypanosoma cruzi is the protozoan pathogen responsible for chagas disease, which is a major public health problem in tropical and subtropical regions of developing countries and particularly in brazil. despite many studies, there is no efficient treatment against chagas disease, and the search for new therapeutic targets specific to t. cruzi is critical for drug development. here, we have revisited 41 protein sequences proposed by the analogous enzyme pipeline, and found that it is possible to ...201627665464
chagas cardiomyopathy in new orleans and the southeastern united states.chagas disease (cd), caused by trypanosoma cruzi, affects 6-7 million people worldwide annually, primarily in central and south america, and >300,000 people in the united states. cd consists of acute and chronic stages. hallmarks of acute cd include fever, myalgia, diaphoresis, hepatosplenomegaly, and myocarditis. symptoms of chronic cd include pathologic involvement of the heart, esophagus, and colon. myocardial involvement is identifiable by electrocardiogram and cardiac magnetic resonance ima ...201627660581
direct identification of trypanosomatids by matrix-assisted laser desorption ionization-time of flight mass spectrometry (dit maldi-tof ms).accurate and rapid determination of trypanosomatids is essential in epidemiological surveillance and therapeutic studies. matrix-assisted laser desorption ionization/time of flight mass spectrometry (maldi-tof ms) has been shown to be a useful and powerful technique to identify bacteria, fungi, metazoa and human intact cells with applications in clinical settings. here, we developed and optimized a maldi-tof ms method to profile trypanosomatids. trypanosomatid cells were deposited on a maldi tar ...201627659938
the effectiveness of natural diarylheptanoids against trypanosoma cruzi: cytotoxicity, ultrastructural alterations and molecular modeling studies.curcumin (cur) is the major constituent of the rhizomes of curcuma longa and has been widely investigated for its chemotherapeutic properties. the well-known activity of cur against leishmania sp., trypanosoma brucei and plasmodium falciparum led us to investigate its activity against trypanosoma cruzi. in this work, we tested the cytotoxic effects of cur and other natural curcuminoids on different forms of t. cruzi, as well as the ultrastructural changes induced in epimastigote form of the para ...201727658305
possible differences in the effects of trypanosoma cruzi on blood cells and serum protein of two wildlife reservoirs.a key step in the dynamics of vector-borne diseases is the role of seasonality. trypanosoma cruzi is a protozoan that causes chagas disease. some wild mammals are considered natural hosts, yet not all mammals show the same response to infection. we explored the effect of t. cruzi on blood parameters in two mammal carnivores, coati (nasua narica) and raccoon (procyon lotor), that were naturally infected in summer and winter seasons. the study was carried out in the zoological park "parque museo d ...201627656956
during acute experimental infection with the reticulotropic trypanosoma cruzi strain tulahuen il-22 is induced il-23-dependently but is dispensable for protection.protective immunity against trypanosoma cruzi, the causative agent of chagas disease, depends on the activation of macrophages by ifn-γ and il-17a. in contrast, il-10 prevents immunopathology. il-22 belongs to the il-10 cytokine family and has pleiotropic effects during host defense and immunopathology, however its role in protection and pathology during t. cruzi infection has not been analyzed yet. therefore, we examined the role of il-22 in experimental chagas disease using the reticulotropic ...201627650379
ent-pimarane and ent-kaurane diterpenes from aldama discolor (asteraceae) and their antiprotozoal activity.aldama discolor (syn.viguiera discolor) is an endemic asteraceae from the brazilian "cerrado", which has not previously been investigated for its chemical constituents and biological activity. diterpenes are common secondary metabolites found in aldama species, some of which have been reported to present potential antiprotozoal and antimicrobial activities. in this study, the known ent-3-α-hydroxy-kaur-16-en-18-ol (1), as well as three new diterpenes, namely, ent-7-oxo-pimara-8,15-diene-18-ol (2 ...201627649126
molecular diagnosis of chagas disease in colombia: parasitic loads and discrete typing units in patients from acute and chronic phases.the diagnosis of chagas disease is complex due to the dynamics of parasitemia in the clinical phases of the disease. the molecular tests have been considered promissory because they detect the parasite in all clinical phases. trypanosoma cruzi presents significant genetic variability and is classified into six discrete typing units tci-tcvi (dtus) with the emergence of foreseen genotypes within tci as tcidom and tci sylvatic. the objective of this study was to determine the operating characteris ...201627648938
trypanosome species, including trypanosoma cruzi, in sylvatic and peridomestic bats of texas, usa.in contrast to other mammalian reservoirs, many bat species migrate long-distances and have the potential to introduce exotic pathogens to new areas. bats have long been associated with blood-borne protozoal trypanosomes of the schizotrypanum subgenus, which includes the zoonotic parasite trypanosoma cruzi, agent of chagas disease. another member of the subgenus, trypanosoma dionisii, infects bats of europe and south america, and genetic similarities between strains from the two continents sugge ...201627647574
ancistectorine d, a naphthylisoquinoline alkaloid with antiprotozoal and antileukemic activities, and further 5,8'- and 7,1'-linked metabolites from the chinese liana ancistrocladus tectorius.from the twigs and stems of the chinese liana ancistrocladus tectorius (ancistrocladaceae), two new 5,8'-coupled naphthylisoquinolines, ancistectorine d (5) and its 6-o-demethyl derivative 6, were isolated, along with two new 7,1'-linked alkaloids, 6-o-methylancistectorine b1 (7) and ancistectorine b2 (8). two further compounds, ancistroealaine a (4) and 6-o-demethyl-8-o-methyl-7-epi-ancistrobrevine d (10), already known from related asian and african ancistrocladus species, were discovered for ...201627646602
myd88 adapter-like (mal)/tirap is required for cytokine production by splenic ly6clotlr2hi but not by ly6chitlr2hi monocytes during trypanosoma cruzi infection.this study continues to explore the plasticity of toll-like receptor 2 (tlr2) previously described in immune response during trypanosoma cruzi infection. here, we have shown that ly6c(hi)tlr2(hi) monocytes were involved in tnf-α and il-12 production, whereas ly6c(lo)tlr2(hi) monocytes were mainly committed to il-10 and tnf-α production during t. cruzi infection independently of tlr agonist used (i.e. tlr2 or tlr9 agonists). another difference between the monocyte populations is that the adapter ...201627646001
nucleolar persistence: peculiar characteristic of spermatogenesis of the vectors of chagas disease (hemiptera, triatominae).all species of triatomines are considered potential vectors of chagas disease and the reproductive biology of these bugs has been studied by different approaches. in 1999, nucleolar persistence during meiosis was observed in the subfamily for the first time. recently, it has been observed that all species within the genus rhodnius exhibit the same phenomenon, suggesting that it may be a synapomorphy of the triatomines. thus, this article aims to analyze the nucleolar behavior during spermatogene ...201627645782
costimulatory effects of an immunodominant parasite antigen paradoxically prevent induction of optimal cd8 t cell protective immunity.trypanosoma cruzi infection is controlled but not eliminated by host immunity. the t. cruzi trans-sialidase (ts) gene superfamily encodes immunodominant protective antigens, but expression of altered peptide ligands by different ts genes has been hypothesized to promote immunoevasion. we molecularly defined ts epitopes to determine their importance for protection versus parasite persistence. peptide-pulsed dendritic cell vaccination experiments demonstrated that one pair of immunodominant cd4+ a ...201627642757
assessing anti-t. cruzi candidates in vitro for sterile cidality.total clearance of the t. cruzi infection - referred to herein as "sterile cure" - seems to be a critical prerequisite for new drug candidates for chagas disease, ensuring long-term beneficial effects for patients in the chronic indeterminate stage. this requirement is notably supported by the recent findings of clinical studies involving posaconazole and fosravuconazole, where the majority of patients treated eventually relapsed after an apparent clearance of parasitaemia at the end of treatmen ...201627639944
persistent infectious and tropical diseases in immigrant correctional populations.a number of infectious diseases amongst travelers and the immigrant populations are a major public health concern. some have a long incubation period or remain asymptomatic or paucisymptomatic for many years before leading to significant clinical manifestations and/or complications. hiv, hepatitis b and c, tuberculosis or latent syphilis are among the most significant persistent diseases in migrants. schistosomiasis and strongyloidiasis, for instance, are persistent helminthic infections that ma ...201627637104
canova medication changes tnf-α and il-10 serum levels in mice infected with trypanosoma cruzi y strain.to identify whether canova medication changes tnf-α and il-10 serum levels in mice infected with trypanosoma cruzi y strain.201627633299
thio- and semicarbazones: hope in the search for treatment of leishmaniasis and chagas disease.trypanosomiasis and leishmaniasis cause severe infections in humans and domestic animals in the tropics. although typical diseases in latin america, globalization and the migration of infected people has spread these diseases to countries in north america, asia and europe. currently available drugs are not effective in the chronic phase, as well as cause side effects and develop resistance.201727629824
chronic heart disease after treatment of oral acute chagas disease.we describe the recurrence of cardiac abnormalities in a patient treated during the acute phase of chagas disease after outpatient follow-up of 5 years.201627627643
ischemic stroke classification and risk of embolism in patients with chagas disease.ischemic stroke (is) and chagas disease are strongly related. nevertheless, little attention has been paid to this association and its natural history. the current guidelines concerning the management and secondary prevention of is are largely based on the incomplete information or extrapolation of knowledge from other stroke etiologies. we performed a retrospective study which compared stroke etiologies among a cohort of hospitalized patients with is and chagas disease. the instituto de pesquis ...201627624118
prevalence of anti-trypanosoma cruzi antibodies in women of childbearing age in socotá, boyacá, 2014.chagas' disease is a parasitic disease caused by the protozoan trypanosoma cruzi. this condition presents epidemiological risk factors associated with socioeconomic conditions and is currently considered an important public health problem. its presence has been reported in endemic regions at elevations of up to 2,000 meters above sea level.201627622629
detection of igg anti-leishmania antigen by flow cytometry as a diagnostic test for cutaneous leishmaniasis.diagnosis of cutaneous leishmaniasis (cl) relies on clinical presentation, parasite isolation, histopathologic evaluation and positive montenegro skin test. however, the low amounts of parasites in the lesion of these individuals make parasite isolation and histopatologic diagnosis unreliable, often leading to false-negative results. also, 15% of people living in endemic areas have sub-clinical infection characterized by positive montenegro skin test, which may contribute to misdiagnosis. althou ...201627622535
molecular mechanisms of cardiac electromechanical remodeling during chagas disease: role of tnf and tgf-β.chagas disease is caused by the trypanosomatid trypanosoma cruzi, which chronically causes heart problems in up to 30% of infected patients. chagas disease was initially restricted to latin america. however, due to migratory events, this disease may become a serious worldwide health problem. during chagas disease, many patients die of cardiac arrhythmia despite the apparent benefits of anti-arrhythmic therapy (e.g., amiodarone). here, we assimilate the cardiac form of chagas disease to an inflam ...201727622432
does native trypanosoma cruzi calreticulin mediate growth inhibition of a mammary tumor during infection?for several decades now an antagonism between trypanosoma cruzi infection and tumor development has been detected. the molecular basis of this phenomenon remained basically unknown until our proposal that t. cruzi calreticulin (tccrt), an endoplasmic reticulum-resident chaperone, translocated-externalized by the parasite, may mediate at least an important part of this effect. thus, recombinant tccrt (rtccrt) has important in vivo antiangiogenic and antitumor activities. however, the relevant que ...201627619675
changes in the immune response after treatment with benznidazole versus no treatment in patients with chronic indeterminate chagas disease.symptomatic chronic chagas disease affects up to 40% of patients infected with trypanosoma cruzi. the lack of reliable early markers of cure after therapy hinders disease management and clinical trials with new drugs. we performed a study with 18 months of follow-up to compare changes in immune parameters and t. cruzi-specific immune responses as surrogate markers of response to therapy between patients treated with benznidazole and untreated patients. this was a pilot, open-label, randomised cl ...201627619190
recombination-driven generation of the largest pathogen repository of antigen variants in the protozoan trypanosoma cruzi.the protozoan parasite trypanosoma cruzi, causative agent of chagas disease, depends upon a cell surface-expressed trans-sialidase (ts) to avoid activation of complement-mediated lysis and to enhance intracellular invasion. however these functions alone fail to account for the size of this gene family in t. cruzi, especially considering that most of these genes encode proteins lacking ts enzyme activity. previous whole genome sequencing of the cl brener clone of t. cruzi identified ~1400 ts vari ...201627619017
molecular characterization of trypanosomatid infections in wild howler monkeys (alouatta caraya) in northeastern argentina.the transmission of trypanosoma cruzi by vectors is confined to the americas, and the infection circulates in at least two broadly defined transmission cycles occurring in domestic and sylvatic habitats. this study sought to detect and characterize infection by t. cruzi and other trypanosomes using pcr strategies in blood samples from free-ranging howler monkeys, alouatta caraya, in the northeastern argentina. blood samples were collected at four sites with variable levels of habitat modificatio ...201627617205
correlation between the virulence of t. cruzi strains, complement regulatory protein expression levels, and the ability to elicit lytic antibody production.trypanosoma cruzi trypomastigotes are able to resist lysis via the complement system, which involves many surface proteins including the complement regulatory protein (crp). to examine the diversity in crp recognition among strains of t. cruzi, the expression levels of the translated protein on trypomastigote surfaces were analyzed by flow cytometry, and associations between protein expression and the biological behavior of these strains, especially the ability to induce lytic antibodies in anim ...201627614283
putting infection dynamics at the heart of chagas disease.in chronic trypanosoma cruzi infections, parasite burden is controlled by effective, but nonsterilising immune responses. infected cells are difficult to detect because they are scarce and focally distributed in multiple sites. however, advances in detection technologies have established a link between parasite persistence and the pathogenesis of chagas heart disease. long-term persistence likely involves episodic reinvasion as well as continuous infection, to an extent that varies between tissu ...201627612651
enhancing glycan isomer separations with metal ions and positive and negative polarity ion mobility spectrometry-mass spectrometry analyses.glycomics has become an increasingly important field of research since glycans play critical roles in biology processes ranging from molecular recognition and signaling to cellular communication. glycans often conjugate with other biomolecules, such as proteins and lipids, and alter their properties and functions, so glycan characterization is essential for understanding the effects they have on cellular systems. however, the analysis of glycans is extremely difficult due to their complexity and ...201727604268
chemodiversity associated with cytotoxicity and antimicrobial activity of piper aduncum var. ossanum.chemical analysis, antimicrobial activity and cytotoxic effects of essential oils (eos) from leaves of piper aduncum var. ossanum from two localities bauta (eo-b) and ceiba (eo-c), artemisa province, cuba, were determined. eos were obtained by hydrodistillation and analyzed by gas chromatography/mass spectrometry. eo-b demonstrated higher activity against s. aureus and l. amazonensis; while a lower cytotoxicity on mammalian cells was observed. both eos displayed the same activity against plasmod ...201627603914
the phosphatidylinositol 3-kinase class iii complex containing tcvps15 and tcvps34 participates in autophagy in trypanosoma cruzi.autophagy is a degradative process by which eukaryotic cells digest their own components to provide aminoacids that may function as energy source under nutritional stress conditions. there is experimental evidence for autophagy in parasitic protists belonging to the family trypanosomatidae. however, few proteins implicated in this process have been characterized so far in these parasites. moreover, it has been shown that autophagy is involved in trypanosoma cruzi differentiation and thus might h ...201627603757
a case of cardboard boxes likely facilitating the biting of a patient by trypanosoma cruzi-infected triatomine bugs.chagas disease is a vector-borne and potentially fatal parasitic disease that is transmitted by the triatomine bug, a nocturnal feeding, flying arthropod, often referred to by its colloquial name, the "kissing bug." vector-borne transmission is considered the most important means of spreading chagas disease in endemic and nonendemic areas. corrugated cardboard boxes may accelerate the spread of these insect vectors to nonendemic areas through their ability to harbor and transport small terrestri ...201627601526
experimental crosses between mepraia gajardoi and m. spinolai and hybrid chromosome analyses reveal the occurrence of several isolation mechanisms.hematophagous insects of the subfamily triatominae include several species with a large variety of shapes, behavior and distribution. they have great epidemiological importance since most of them transmit the flagellated protozoan trypanosoma cruzi, the etiologic agent of chagas disease. in this subfamily several cases of species hybridization have been reported under experimental and natural conditions. mepraia is a genus of triatominae endemic in chile, responsible for transmitting t. cruzi in ...201627600593
antiparasitic activity of diterpenoids against trypanosoma cruzi.twenty-seven diterpenes, including abietanes, labdanes, abeoabietanes, halimanes, and pimaranes, have been evaluated against epimastigote and intracellular amastigote forms of trypanosoma cruzi and also against lc5 and nctc cell lines. royleanones (3, 4, and 5) and a further abietane (12), obtained by purification of plectranthus spp. extracts, were the most active compounds on epimastigotes, showing ic50 values similar (1.73 µg/ml, 12) or even lower (0.39, 0.99, and 1.20 µg/ml, 3, 4, and 5 resp ...201727599261
[maternal-fetal transmission of trypanosoma cruzi, a health problem slightly studied in mexico: case chiapas].to determine the trypanosoma cruzi infection prevalence in 1125 pregnant women and the transmission frequency to their children from tapachula and palenque, chiapas.201627598936
occurrence and distribution of triatomines (hemiptera: reduviidae) in municipalities of the northeastern region of minas gerais state, brazil.triatomines are targeted for the control of chagas disease in endemic areas of brazil.201727598640
behavioral fever response in rhodnius prolixus (reduviidae: triatominae) to intracoelomic inoculation of trypanosoma cruzi.behavioral fever is a response to infections with microorganisms observed in some poikilothermic animals. rhodnius prolixus is involved in the transmission of two parasites: trypanosoma cruzi (pathogenic for humans and transmitted in feces) and trypanosoma rangeli (non-pathogenic for humans, pathogenic for rhodnius and transmitted by the bite of an infected individual). only t. rangeli is found in the hemolymph of rhodnius as it travels to the salivary glands.201727598628
Refresh
firstprev
12345678910...
nextlast
Displaying items 601 - 700 of 17982