| parasitological cure of acute and chronic experimental chagas disease using the long-acting experimental triazole tak-187. activity against drug-resistant trypanosoma cruzi strains. | we investigated the activity of tak-187, an experimental antifungal triazole with a long terminal half-life in several experimental animals, against trypanosoma cruzi. in vitro studies showed that the minimal inhibitory concentration (mic) against the (extracellular) epimastigote form was 0.3-1 microm, while the corresponding concentration against clinically relevant intracellular amastigotes was 1 nm. at the mic the endogenous epimastigote c4,14-desmethyl sterols were replaced by di- and tri-me ... | 2003 | 12507836 |
| new pcr assay using glucose-6-phosphate dehydrogenase for identification of leishmania species. | glucose-6-phosphate dehydrogenase (g6pd) is one of the multilocus enzymes used to identify leishmania by zymodeme analysis. the polymorphic pattern revealed by partial characterization of the gene encoding g6pd generated molecular markers useful in the identification of different leishmania species by pcr. initially degenerate oligonucleotides were designed on the basis of data on the conserved active center described for other organisms. primers for reverse transcription-pcr experiments, design ... | 2003 | 12574243 |
| evidence that development of severe cardiomyopathy in human chagas' disease is due to a th1-specific immune response. | the role of interleukin 10 (il-10) and gamma interferon (ifn-gamma) on the development of pathology in human chagas' disease was investigated. two categories of patients, low and high producers of ifn-gamma, were identified based on the levels of secretion of this cytokine in the supernatant of peripheral blood mononuclear cell (pbmc) cultures. eighty-three percent of the patients presenting with cardiac disease (card) of different degrees and 59% of the patients with the indeterminate form of d ... | 2003 | 12595431 |
| [lupus hepatitis]. | we report the case of 42 year-old man who presents an acute polyarthritis associated with systemic manifestation and immunologic disorders related to systemic lupus erythematosus. hepatic tests show cholostase and cytolysis. hepatic involvement is linked with systemic lupus erythematosus after exclusion of hepatotoxic drugs, viral hepatitis and absence of anti mitochondrial and anti muscle antibodies. lupus hepatitis seems to be correlated with autoantibodies to ribosomal p protein. its treatmen ... | 2002 | 12611355 |
| should trypanosoma cruzi be called "cruzi" complex? a review of the parasite diversity and the potential of selecting population after in vitro culturing and mice infection. | morpho-biological diversity of trypanosoma cruzi has been known since chagas' first works in 1909. several further studies confirmed the morphological differences among the parasite strains, which were isolated from different reservoirs and vectors, as well as from human beings. in the early sixties, antigenic differences were found in the parasite strains from various sources. these differences, coupled to the observation of regional variations of the disease, led to the proposal of the term cr ... | 2003 | 12700855 |
| genetic heterogeneity of trypanosoma cruzi and its direct anticancer effect in cultured human tumor cells. | the direct inhibitory effect of trypanosoma cruzi epimastigote lysates on in vitro cultured human breast cancer mcf-7 cells differs in various genetic groups and cloned subgroups of trypanosoma. | 2003 | 12717523 |
| identification of hla-a*0201-restricted cytotoxic t-cell epitopes of trypanosoma cruzi tcp2beta protein in hla-transgenic mice and patients. | trypanosoma cruzi-specific cytotoxic t-lymphocyte (ctl) responses are critical in the control of parasite growth and will play an important part in therapeutic and prophylactic t. cruzi vaccines. the identification of parasite-specific epitopes that are efficiently recognized by ctls is the first step in the development of future vaccines. hla-a2 transgenic mice (hhd) were shown to provide a powerful model for studying the induction of hla-a*0201-restricted immune responses in vivo, since these ... | 2003 | 12737989 |
| hantavirus infection in people inhabiting a highly endemic region of the gran chaco territory, paraguay: association with trypanosoma cruzi infection, epidemiological features and haematological characteristics. | the seroprevalences of anti-hantavirus antibodies were determined in 712 individuals (551 indians, 140 mennonites of german ancestry, and 21 paraguayans of spanish ancestry) inhabiting a region of western paraguay in the gran chaco territory of south america. the overall seroprevalence of hantavirus infection among the 712 subjects, who were aged 2-80 years, was 42.7% (45.2% in the indians and 34.2% in the non-indians). of the 672 subjects also checked for antibodies against trypanosoma cruzi, 2 ... | 2003 | 12803858 |
| trypanosoma cruzi: identification and characterization of a novel ribosomal protein l27 (tcrl27) that cross-reacts with an affinity-purified anti-sm antibody. | small nuclear ribonucleoproteins (snrnps) are involved in trans-splicing processing of pre-mrna in trypanosoma cruzi. to clone t. cruzi snrnps we screened an epimastigote cdna library with a purified antibody raised against the sm-binding site of a yeast sequence. a clone was obtained containing a 507 bp-insert with an orf of 399 bp and coding for a protein of 133 amino acids. sequence analysis revealed high identity with the l27 ribosomal proteins from different species including: canis familia ... | 2003 | 12866796 |
| five new cassane diterpenes from myrospermum frutescens with activity against trypanosoma cruzi. | five novel cassane diterpenes (1-5) with activity against trypanosoma cruzi were isolated from leaves of myrospermum frutescens. the structures were determined as 18-hydroxycassan-13,15-diene (1), 6beta,18-dihydroxycassan-13,15-diene (2), 6beta-hydroxy-18-acetoxycassan-13,15-diene (3), 18-acetoxy-13,15-diene-19-cassanoic acid (4), and 6beta,13beta-dihydroxy-18-acetoxycassan-14(17),15-diene (5). structures were elucidated by spectroscopic analysis (nmr and hrcims) and by the synthesis of derivati ... | 2003 | 12880308 |
| tattooing and transfusion-transmitted diseases in brazil: a hospital-based cross-sectional matched study. | presence of tattoos has been a criterion for temporary deferral of blood donors. scientific evidence remains equivocal regarding the association between tattooing and transfusion-transmitted diseases (ttds). | 2003 | 12889691 |
| [dilated cardiomyopathy in patients with chronic chagasic infection: report of two fatal autochthonous cases from rio negro, state of amazonas, brazil]. | two fatal cases of human chronic chagasic cardiomyopathy are reported, for the first time, in autochthonous patients from rio negro, amazonas state. both cases, (45 year old man and 44 year old woman) who were born and lived their whole lives in the rio negro region, in the northern part of the state of amazonas, reported having been bitten several times by triatomine bugs in their camping huts while gathering pia ava fibers. the patients, who had confirmed positive serology for trypanosoma cruz ... | 2003 | 12908042 |
| experimental trypanosoma cruzi infection alters the shaping of the central and peripheral t-cell repertoire. | we investigated the thymic and peripheral t-lymphocyte subsets in balb/c mice undergoing acute or chronic trypanosoma cruzi infection, in terms of expression of particular vbeta rearrangements of the t-cell receptor. we first confirmed the severe depletion of cd4(+)cd8(+) thymocytes following acute t. cruzi infection. by contrast, the numbers of cd4(+)cd8(+) cells in subcutaneous lymph nodes increased up to 16 times. in subcutaneous lymph nodes, we found cd4(+)cd8(+) cells that expressed prohibi ... | 2003 | 12919850 |
| cloning and characterization of a gene encoding an immunoglobulin-binding receptor on the cell surface of some members of the family trypanosomatidae. | several members of the trypanosomatidae family, when freshly isolated from their mammalian hosts, have immunoglobulins adsorbed to their cell surfaces. however, a significant portion of these antibody molecules is not parasite specific, i.e., the immunoglobulins are bound to the parasite's cell surface molecules via noncognitive interactions. it has been proposed that this noncognitive adsorption of immunoglobulins to the parasite is mediated by an fc-like receptor present in several members of ... | 2003 | 12933849 |
| calcium regulation in protozoan parasites. | the calcium ion (ca(2+)) is used as a major signaling molecule in a diverse range of eukaryotic cells including several human parasitic protozoa, such as trypanosoma cruzi, trypanosoma brucei, leishmania spp, plasmodium spp, toxoplasma gondii, cryptosporidium parvum, entamoeba histolytica, giardia lamblia and trichomonas vaginalis. ca(2+) is critical for invasion of intracellular parasites, and its cytosolic concentration is regulated by the concerted operation of several transporters present in ... | 2003 | 12941405 |
| bioactive alkyl phenols and embelin from oxalis erythrorhiza. | the benzoquinone embelin and four alkyl phenols were isolated from an argentinean collection of oxalis erythrorhiza. 3-heptadecyl-5-methoxy-phenol is reported for the first time. the structures were determined by spectroscopic methods. embelin presented inhibitory effect on methicillin-resistant staphylococcus aureus, escherichia coli and the dermatophytic fungi epidermophyton floccosum, microsporum canis, microsporum gypseum, trichophyton mentagrophytes and trichophyton rubrum with mics ranging ... | 2003 | 12963150 |
| [difference in the antigenic composition of trypanosoma cruzi strains isolated from man and opossums. (preliminary note)]. | | 1962 | 13939268 |
| specific cleavage sites on human igg subclasses by cruzipain, the major cysteine proteinase from trypanosoma cruzi. | cruzipain, the major cysteine proteinase of trypanosoma cruzi, might have other biological roles than its metabolic functions. in this report, we have explored the interaction of cruzipain with molecules of the immune system. the enzyme was used to digest all human igg subclasses at different ph values and lengths of time. at ph 7.3, all subclasses were readily split at the hinge region. immunoblot and amino acid sequence analysis showed fragments of igg1 and igg3 to be compatible with fab and f ... | 2003 | 14550893 |
| the syrian hamster as a model for the dilated cardiomyopathy of chagas' disease: a quantitative echocardiographical and histopathological analysis. | chronic chagas' disease cardiomyopathy (ccc) is caused by the protozoan trypanosoma cruzi, and it affects 30% of the 16-18 million people infected in latin america. a good rodent model that develops a dilated cardiomyopathy closely resembling human ccc after t. cruzi infection is still needed. we compared the cardiomyopathy developed by t. cruzi-infected syrian hamsters with human chagas' disease cardiomyopathy using quantitative methods. female hamsters were infected with 3.5 x 10(4) (g1, n = 1 ... | 2003 | 14554253 |
| 2,4-diaminopyrimidines as inhibitors of leishmanial and trypanosomal dihydrofolate reductase. | this paper describes the synthesis of 4'-substituted and 3',4'-disubstituted 5-benzyl-2,4-diaminopyrimidines as selective inhibitors of leishmanial and trypanosomal dihydrofolate reductase. compounds were then assayed against the recombinant parasite and human enzymes. some of the compounds showed good activity. they were also tested against the intact parasites using in vitro assays. good activity was found against trypanosoma cruzi, moderate activity against trypanosoma brucei and leishmania d ... | 2003 | 14556785 |
| synthesis and evaluation of novel 7-trifluoromethyl-4-(4-substituted anilino)quinolines as antiparasitic and antineoplastic agents. | several novel derivatives bearing the 7-trifluoromethyl-4-(4-substituted anilino)-quinoline skeleton were synthesized and evaluated for their in vitro activity against the blood streaming form of the parasites trypanosoma brucei rhodesiense, the trypomastigotes of trypanosoma cruzi cultured in rat skeletal myoblasts, the amastigotes form of leishmania donovani, plasmodium falciparum (k1 strain) infected erythrocyte suspension, as well as their toxicity towards rat skeletal l-6 cells. in addition ... | 2003 | 14558440 |
| [apoptosis: physiological cell death and its role in pathogenesis of diseases]. | apoptosis is a physiological process of cell death by which a single cell may be eliminated from the living tissue. since the process is mediated by specific proteins encoded in the host's genome, it is also a programmed cell death. apoptosis is responsible for tissue remodelling during the development and turnover of normal tissue (e.g. haematopoietic cells) throughout the life span of multicellular organisms. in contrast to cells undergoing a pathological cell death (necrosis), the morphologic ... | 2003 | 14558480 |
| cloning and characterisation of the udp-glucose 4'-epimerase of trypanosoma cruzi. | trypanosoma cruzi incorporates galactose into many of its cell-surface glycoconjugates but it is unable to transport this sugar through its hexose transporter. epimerisation of udp-glucose to udp-galactose by udp-glucose 4'-epimerase may be the only way that the parasites can obtain galactose. here, we describe cloning the t. cruzi udp-glc 4'-epimerase (tcgale) gene and show that it is functional by complementing an escherichia coli epimerase-deficient strain. the t. cruzi gale gene encodes a 42 ... | 2003 | 14563536 |
| importance of cd8 t cell-mediated immune response during intracellular parasitic infections and its implications for the development of effective vaccines. | obligatory intracellular parasites such as plasmodium sp, trypanosoma cruzi, toxoplasma gondii and leishmania sp are responsible for the infection of hundreds of millions of individuals every year. these parasites can deliver antigens to the host cell cytoplasm that are presented through mhc class i molecules to protective cd8 t cells. the in vivo priming conditions of specific cd8 t cells during natural infection are largely unknown and remain as an area that has been poorly explored. the antip ... | 2003 | 14605680 |
| 5ht1a serotonin receptor agonists inhibit plasmodium falciparum by blocking a membrane channel. | to identify new leads for the treatment of plasmodium falciparum malaria, we screened a panel of serotonin (5-hydroxytryptamine [5ht]) receptor agonists and antagonists and determined their effects on parasite growth. the 5ht1a receptor agonists 8-hydroxy-n-(di-n-propyl)-aminotetralin (8-oh-dpat), 2,5-dimethoxy-4-iodoamphetamine, and 2,5-dimethoxy-4-bromophenylethylamine inhibited the growth of p. falciparum in vitro (50% inhibitory concentrations, 0.4, 0.7, and 1.5 microm, respectively). in fur ... | 2003 | 14638487 |
| sialyl-tn antigen expression and o-linked galnac-thr synthesis by trypanosoma cruzi. | most trypanosoma cruzi o-glycans are linked to thr/ser residues via n-acetylglucosamine. we report that the mucin-type carcinoma-associated sialyl-tn antigen (neuac-galnac-o-ser/thr) is expressed by t. cruzi. a specific mab allowed us to localize the antigen on the surface of epimastigotes and to identify reactive components in parasite lysates (32, 60, and 94kda). in addition, ppgalnac-t activity was characterized in epimastigotes, and direct evidence was obtained for the in vitro incorporation ... | 2003 | 14652017 |
| junctional adhesion molecules (jams): more molecules with dual functions? | junctional adhesion molecules (jams) are members of an immunoglobulin subfamily expressed by leukocytes and platelets as well as by epithelial and endothelial cells, in which they localize to cell-cell contacts and are specifically enriched at tight junctions. the recent identification of extracellular ligands and intracellular binding proteins for jams suggests two functions for jams. jams associate through their extracellular domains with the leukocyte beta2 integrins lfa-1 and mac-1 as well a ... | 2004 | 14657270 |
| mhc class i and class ii genes in mexican patients with chagas disease. | chagas' disease contributes significantly to cardiovascular morbidity and mortality in several latin-american countries. previous studies have reported the effect of the human leukocyte antigen (hla) molecules in the immune response regulation of trypanosoma cruzi infection, and the association of hla antigens with heart damage. we studied the major histocompatibility complex (mhc) class i (hla-a and hla-b), and class ii (hla-dr) genes in a sample of 66 serologically positive individuals with an ... | 2004 | 14700597 |
| skeletal muscle regeneration and trypanosoma cruzi-induced myositis in rats. | although chagas' disease is known to provoke severe acute myositis, information on muscle regeneration is missing. the current paper shows that during t. cruzi infection in rats, skeletal muscle parasitism and the consequent inflammatory process are higher in muscle with a high proportion of type-i myofibres (soleus and diaphragm). immunohistochemistry showed an acute inflammatory process characterized by ed1+ and ed2+ macrophages, cd8+ lymphocytes, and nk cells. parasite-nest rupture provoked s ... | 2004 | 14702175 |
| characterization of leishmania chagasi dna topoisomerase ii: a potential chemotherapeutic target. | dna topoisomerase ii (topo ii), an enzyme essential for cellular replication, is an eminent target for antimicrobial therapy against leishmania chagasi, the major cause of visceral leishmaniasis in latin america. the complete l. chagasi (lch) top2 gene, encoding l. chagasi topo ii, was isolated from genomic dna using the polymerase chain reaction. the lchtop2 gene revealed an open reading frame (orf) of 3,711 base pairs predicting a protein with 1,236 amino acids and an estimated molecular weigh ... | 2003 | 14723357 |
| trypanosoma cruzi: molecular cloning and characterization of the s-adenosylhomocysteine hydrolase. | s-adenosylhomocysteine (adohcy) hydrolase has emerged as an attractive target for antiparasitic drug design because of its role in the regulation of all s-adenosylmethionine-dependent transmethylation reactions, including those reactions crucial for parasite replication. from a genomic dna library of trypanosoma cruzi, we have isolated a gene that encodes a polypeptide containing a highly conserved adohcy hydrolase consensus sequence. the recombinant t. cruzi enzyme was overexpressed in escheric ... | 2003 | 14969692 |
| gene synteny and evolution of genome architecture in trypanosomatids. | the trypanosomatid protozoa trypanosoma brucei, trypanosoma cruzi and leishmania major are related human pathogens that cause markedly distinct diseases. using information from genome sequencing projects currently underway, we have compared the sequences of large chromosomal fragments from each species. despite high levels of divergence at the sequence level, these three species exhibit a striking conservation of gene order, suggesting that selection has maintained gene order among the trypanoso ... | 2004 | 15003838 |
| inactivation of protozoan parasites in red blood cells using inactine pen110 chemistry. | the transmission of parasites, including babesia, plasmodia, and trypanosoma cruzi, via transfusions is an important public health concern. inactine technology is a pathogen-reduction process that utilizes pen110, an electrophilic agent that inac-tivates a wide range of pathogens by disrupting nucleic acid replication. the present study investigated the effect of pen110 treatment on the viability of protozoa in rbcs. | 2004 | 15104655 |
| [comparison of the indirect immunofluorescent (ifat), elisa test and the comercial chagatek test for anti-trypanosoma cruzi antibodies detection]. | chagas disease is a public health problem in colombia, particularly in the eastern region. because of human migration from rural areas to urban centers, the possibility of transfusional transmission becomes increasingly important. however the risk can be minimized by a careful screening of blood donors by means of serological tests. colombian blood banks use comercial, foreign serological tests for screening for t. cruzi infection. the purpose of the current study was to compare the ifat and eli ... | 2004 | 15239607 |
| [nitric oxide and anti-protozoan chemotherapy]. | constitutive nitric oxide (no) is generated by constitutively expressed types of no-synthase enzymes (nos-i and -iii), being involved in physiological processes such as nervous transmission and vasodilatation. inducible no, synthesized by the no-synthase isoform nos-ii, is an anti-pathogen and tumoricidal agent. however, inducible no production requires a tight control because of cytotoxic and immune-modulation activity. no produced by human and canine macrophages has long been demonstrated to b ... | 2004 | 15305696 |
| the trypanosoma cruzi membrane mucin agc10 inhibits t cell activation and il-2 transcription through l-selectin. | trypanosoma cruzi infection is associated with a severe t cell unresponsiveness to antigens and mitogens characterized by a decreased il-2 synthesis and by nitric oxide (no) production. although spleen cell unresponsiveness to cona was less severe in infected ifn-gammar-/- or inducible nitric oxide synthase (inos)-/- mice than in control littermates, il-2 inhibition was as severely impaired. ag c10, a t. cruzi mucin, inhibited t cell proliferation as well as il-2 secretion and il-2 mrna inductio ... | 2004 | 15314038 |
| chagas' disease in an obstetrical patient. | we report a case of a parturient with documented chronic chagas' disease with cardiac manifestations presenting for labor management and complicated by the need for emergent hysterectomy after delivery. chagas' disease is a common human hematogenous trypanosomiasis in central and south america which is now, because of population migration, appearing in the usa. this disease predominantly affects the heart and the gastrointestinal system. this report discusses the parasite, the acute and chronic ... | 1996 | 15321360 |
| concurrent cerebral american trypanosomiasis and toxoplasmosis in a patient with aids. | we report a case of concurrent cerebral infection with trypanosoma cruzi and toxoplasma gondii in a patient with acquired immunodeficiency syndrome (aids). a 22-year-old el salvadoran man initially improved during receipt of antitoxoplasmosis therapy, but he had rapidly progressive hemiplegia. magnetic resonance imaging showed an abnormal finding in the left internal capsule, and cytological analysis of cerebrospinal fluid revealed t. cruzi trypomastigotes. despite prompt therapy with nifurtimox ... | 2004 | 15356839 |
| chagasic meningoencephalitis: case report of a recently included aids-defining illness in brazil. | recently, reactivation of chagas disease (meningoencephalitis and/or myocarditis) was included in the list of aids-defining illnesses in brazil. we report a case of a 52-year-old patient with no history of previous disease who presented acute meningoencephalitis. direct examination of blood and cerebrospinal fluid (csf) showed trypanosoma cruzi. csf culture confirmed the diagnosis. serological assays for t. cruzi and human immunodeficiency virus (hiv) were positive. despite treatment with benzni ... | 2004 | 15361971 |
| eco-epidemiological aspects of trypanosoma cruzi, trypanosoma rangeli and their vector (rhodnius pallescens) in panama. | the eco-epidemiology of t. cruzi infection was investigated in the eastern border of the panama canal in central panama. between 1999 and 2000, 1110 triatomines were collected: 1050 triatomines (94.6%) from palm trees, 27 (2.4%) from periurban habitats and 33 (3.0%) inside houses. all specimens were identified as r. pallescens. there was no evidence of vector domiciliation. salivary glands from 380 r. pallescens revealed a trypanosome natural infection rate of 7.6%, while rectal ampoule content ... | 2004 | 15361974 |
| biochemical characterization of new strains of trypanosoma cruzi and t. rangeli isolates from peru and mexico. | seven trypanosome stocks isolated have been characterized by lectin agglutination, isoenzyme analysis, and the end products excreted. the stocks were isolated from different geographic areas-one from mexico (tm5), and six from peru, four of these isolated from different species of triatoma (tp504, tp702, tp704 and tp706), the other two isolated from the salivary glands of rhodnius ecuadorensis (tra605 and tra606). additionally, one strain of trypanosoma cruzi isolated from a human case (strain t ... | 2004 | 15368126 |
| trypanosoma cruzi myocardial infection reactivation presenting as complete atrioventricular block in a chagas' heart transplant recipient. | a 56-year-old man underwent orthotopic heart transplantation because of end-stage chagas' cardiomyopathy. one hundred and ten days following heart transplantation, an electrocardiogram tracing showed complete atrioventricular block, which was treated with temporary transvenous pacemaker insertion. an underlying endomyocardial biopsy was graded 3a. the patient was treated with pulse steroid therapy. one week later, the patient died of multiorgan failure secondary to septicemia. a careful review o ... | 2004 | 15556779 |
| protective immunity against trypanosoma cruzi provided by oral immunization with phytomonas serpens: role of nitric oxide. | we have previously demonstrated that phytomonas serpens, a tomato parasite, shares antigens with trypanosoma cruzi, the protozoa that causes chagas' disease. these antigens are recognized by human sera and induce protective immunity in balb/c mice. in the present study, inducible nitric oxide synthase (inos) knockout (ko) mice and c57bl/6 mice treated with the nitric oxide inhibitor, aminoguanidine (ag, 50 mg kg(-1)) infected with t. cruzi, were used to demonstrate the role of nitric oxide (no) ... | 2005 | 15585334 |
| predominance of lineage i among trypanosoma cruzi isolates from venezuelan patients with different clinical profiles of acute chagas' disease. | trypanosoma cruzi isolates from 23 acute chagasic patients from localities of western venezuela (state of barinas) where chagas' disease is endemic were typed using ribosomal and mini-exon gene markers. results showed that isolates of the two major phylogenetic lineages, t. cruzi i and t. cruzi ii, were isolated from these patients. six isolates (26%) were typed as t. cruzi ii and 17 (74%) as belonging to t. cruzi lineage i. analysis of random amplified polymorphic dna (rapd) patterns confirmed ... | 2004 | 15598264 |
| myocarditis, microbes and autoimmunity. | acute and chronic myocarditis can be caused by a number of infectious agents, including viruses, bacteria and protozoa. these diseases are refractory to treatment, and the development of rational therapies will require a detailed understanding of the mechanisms that underlie the pathological inflammatory responses. here, we review three infectious myocarditides that, despite the dissimilarity of the microorganisms, share several common features: (i) the microbes replicate in the heart; but (ii) ... | 2004 | 15621561 |
| distinct patterns of trypanosoma cruzi infection in leontopithecus rosalia in distinct atlantic coastal rainforest fragments in rio de janeiro--brazil. | previous studies on infection of trypanosoma cruzi in the poço das antas biological reserve population of wild free-ranging leontopithecus rosalia have shown the presence of genotype t. cruzi ii, associated in brazil with human disease. herein, this study has been extended, the infection being evaluated in l. rosalia of 3 different tamarin populations, inhabiting distinct forest areas located in the same atlantic coastal rainforest. edentata, marsupialia, rodentia and chiroptera were examined ex ... | 2004 | 15648693 |
| enzootic transmission of trypanosoma cruzi and t. rangeli in the federal district of brazil. | the federal district of brazil (df) lies within the cerrado biome, where open shrubland (savannas) is interspersed with riverside gallery forests and permanent swamps (veredas). trypanosoma cruzi-infected native triatomines occur in the area, but the enzootic transmission of trypanosomatids remains poorly characterized. a parasitological survey involving sylvatic triatomines (166 rhodnius neglectus collected from mauritia flexuosa palms) and small mammals (98 marsupials and 70 rodents, totaling ... | 2004 | 15654478 |
| placental alkaline phosphatase (plap) study in diabetic human placental villi infected with trypanosoma cruzi. | previous work has demonstrated that plap activity decreases in serum and placental villi from term chagasic and diabetic pregnant women. in vitro, t. cruzi induces changes in human syncytiotrophoblast's plap. our aim was to determine if infection with t. cruzi induces changes in plap activity in diabetic and chagasic women's placenta, in order to elucidate if plap plays a role in the mechanisms of interaction between placenta and t. cruzi, and whether hyperglycemic conditions could worsen the pl ... | 2005 | 15664416 |
| mammalian cell invasion and intracellular trafficking by trypanosoma cruzi infective forms. | trypanosoma cruzi, the etiological agent of chagas disease, occurs as different strains or isolates that may be grouped in two major phylogenetic lineages: t. cruzi i, associated with the sylvatic cycle and t. cruzi ii, linked to the human disease. in the mammalian host the parasite has to invade cells and many studies implicated the flagellated trypomastigotes in this process. several parasite surface components and some of host cell receptors with which they interact have been identified. our ... | 2005 | 15692679 |
| mapping of b-cell epitopes in a trypanosoma cruzi immunodominant antigen expressed in natural infections. | tc40 is an immunodominant antigen present in natural trypanosoma cruzi infections. this immunogen was thoroughly mapped by using overlapping amino acid sequences identified by gene cloning and chemical peptide synthesis. to map continuous epitopes of the tc40 antigen, an epitope expression library was constructed and screened with sera from human chagasic patients. a major, linear b-cell epitope spanning residues 403 to 426 (pakaaappaa) was identified in the central domain of tc40. a synthetic p ... | 2005 | 15699429 |
| structural considerations for the rational design of selective anti-trypanosomal agents: the role of the aromatic clusters at the interface of triosephosphate isomerase dimer. | seven benzothiazoles were successfully docked into the interface of both human and trypanosomal triosephosphate isomerases, and the binding free energies of each complex were calculated using the program autodock. structural and energetical analysis of the complexes showed that large benzothiazoles could form more stable complexes with trypanosomal triosephosphate isomerase than with human triosephosphate isomerase. thus, we hypothesize that the distribution of the residues forming the aromatic ... | 2005 | 15707966 |
| inhibitory action of marine algae extracts on the trypanosoma cruzi dihydroorotate dehydrogenase activity and on the protozoan growth in mammalian cells. | trypanosoma cruzi, the causative agent of chagas' disease, replicates in mammalian cells and relies on the de novo pyrimidine biosynthetic pathway that supplies essential precursors for nucleic acid synthesis. the protozoan dihydroorotate dehydrogenase (dhod), the fourth enzyme of the pathway catalyzing production of orotate from dihydroorotate, markedly differs from the human enzyme. this study was thus aimed to search for potent inhibitors against t. cruzi dhod activity, and a number of methan ... | 2004 | 15710552 |
| an in vivo role for trypanosoma cruzi calreticulin in antiangiogenesis. | angiogenesis leads to neovascularization from existing blood vessels. it is associated with tumor growth and metastasis and is regulated by pro- and antiangiogenic molecules, some of them currently under clinical trials for cancer treatment. during the last few years we have cloned, sequenced and expressed a trypanosoma cruzi calreticulin gene (tccrt). its product, tccrt, a 45 kda protein, is more than 50% identical to human crt (hucrt). tccrt, present on the surface of trypomastigotes, binds bo ... | 2005 | 15760653 |
| real time pcr strategy for the identification of major lineages of trypanosoma cruzi directly in chronically infected human tissues. | two evolutionary lineages, called trypanosoma cruzi i and ii, have been identified in t. cruzi, the etiologic agent of human chagas disease. here, we describe a molecular strategy for direct genetic typing of these major groups of t. cruzi directly in human tissues. the protocol is based on heminested pcr amplification of the d7 region of the 24salpha ribosomal dna (rdna), followed by identification of the products using denaturation curves in real time pcr. the repetitive nature of the gene, an ... | 2004 | 15777917 |
| proteolytic expression in blastocrithidia culicis: influence of the endosymbiont and similarities with virulence factors of pathogenic trypanosomatids. | blastocrithidia culicis is an insect trypanosomatid that presents bacterial endosymbionts. the cell-associated and secreted proteinases of the endosymbiont-bearing and aposymbiotic strains were compared through the incorporation of proteinaceous substrates into sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page). few qualitative changes could be detected in the proteolytic zymograms in the 2 strains studied when gelatin, casein, haemoglobin or bovine serum albumin (bsa) were tes ... | 2005 | 15830815 |
| trypanosoma cruzi posttranscriptionally up-regulates and exploits cellular flip for inhibition of death-inducing signal. | intracellular persistence of the protozoan parasite, trypanosoma cruzi, is an aggravating cause of chagas' disease, involving that the protozoan infection specifically inhibits death receptor-mediated apoptosis of host cells. here we demonstrate that the parasite dramatically up-regulates cellular flice inhibitory protein (c-flip), the only known mammalian inhibitor specific for death receptor signaling, in infected cells by an unusual, posttranscriptional stabilization of the short-lived protei ... | 2005 | 15917295 |
| risk factors associated with house infestation by the chagas disease vector triatoma pallidipennis in cuernavaca metropolitan area, mexico. | chagas disease caused by infection with trypanosoma cruzi chagas (kinetoplastida: trypanosomatidae) is widespread in mexico, transmitted by various triatomine bugs (hemiptera: reduviidae). the only domestic vector in cuernavaca (population 650 000) is triatoma pallidipennis (ståhl) with t. cruzi seroprevalence ranging from 1% to 9% in the resident human population. we surveyed possible risk factors for t. pallidipennis infestation at cuernavaca (altitude 1200-2200 m) on south-western slopes of t ... | 2005 | 15958028 |
| continuous-flow/stopped-flow system for enzyme immunoassay using a rotating bioreactor: determination of chagas disease. | the high sensitivity that can be attained using an immunoassays coupled to a rotating bioreactor with electrochemical detection mediated by [os(bpy)2cl(pycooh)]cl, has been verified for the detection of trypanozoma cruzi (t. cruzi), this protozoan parasite causes chagas disease, affecting more than 18 million people in central and south america. antibodies in the serum sample are allowed to react immunologically with whole homogenates of the parasite as antigen that are immobilized on a rotating ... | 2004 | 16023958 |
| inhibitors of trypanosoma cruzi trypanothione reductase revealed by virtual screening and parallel synthesis. | in an approach to discover new inhibitors of trypanothione reductase from trypanosoma cruzi, the causative agent of chagas' disease, a virtual high-throughput screening was performed. two structurally new types of inhibitors emerged, the antimicrobial chlorhexidine {1,1'-hexamethylenebis[5-(4-chlorophenyl)biguanide]}, a linear competitive inhibitor (k(i) = 2 +/- 1 microm), and a piperidine derivative acting as mixed inhibitor (k(i) = 6.2 +/- 2 microm and k(i)' = 8.5 +/- 2 microm). neither compou ... | 2005 | 16033259 |
| lipophilic antifolate trimetrexate is a potent inhibitor of trypanosoma cruzi: prospect for chemotherapy of chagas' disease. | trypanosoma cruzi, a protozoan parasite, is the causative agent for chagas' disease, which poses serious public health problem in latin america. the two drugs available for the treatment of this disease are effective only against recent infections and are toxic. dihydrofolate reductase (dhfr) has a proven track record as a drug target. the lipophilic antifolate trimetrexate (tmq), which is an fda-approved drug for the treatment of pneumocystis carinii infection in aids patients, is a potent inhi ... | 2005 | 16048931 |
| emerging infectious agents. | as new agents of infectious disease continue to emerge and old antagonists reemerge, it is clear that the war on infectious disease is far from over. indeed, the appearance of sars during the past year is the latest example of the continuing challenges posed by agents of infectious disease. emerging agents are threats not only to the general population, but also to recipients of blood transfusions. today a variety of emerging agents are of concern to transfusion safety including trypanosoma cruz ... | 2005 | 16050150 |
| characterization of a multisubunit transcription factor complex essential for spliced-leader rna gene transcription in trypanosoma brucei. | in the unicellular human parasites trypanosoma brucei, trypanosoma cruzi, and leishmania spp., the spliced-leader (sl) rna is a key molecule in gene expression donating its 5'-terminal region in sl addition trans splicing of nuclear pre-mrna. while there is no evidence that this process exists in mammals, it is obligatory in mrna maturation of trypanosomatid parasites. hence, throughout their life cycle, these organisms crucially depend on high levels of sl rna synthesis. as putative sl rna gene ... | 2005 | 16055738 |
| deoxyuridine triphosphate nucleotidohydrolase as a potential antiparasitic drug target. | this paper describes a structure-activity study to identify novel, small-molecule inhibitors of the enzyme deoxyuridine 5'-triphosphate nucleotidohydrolase (dutpase) from parasitic protozoa. the successful synthesis of a variety of analogues of dump is described in which the substituents are introduced at the 3'- and 5'-positions, together with variation in the heteroatom at the 5'-position. the compounds were assayed against recombinant plasmodium falciparum and leishmania major enzymes and the ... | 2005 | 16161998 |
| peridomiciliary colonies of triatoma vitticeps (stal, 1859) (hemiptera, reduviidae, triatominae) infected with trypanosoma cruzi in rural areas of the state of espírito santo, brazil. | in brazil, the colonization of human dwellings by triatomines occurs in areas with native vegetation of the caatinga or cerrado types. in areas of atlantic forest such as in the brazilian state of espírito santo, there are no species adapted to live in human habitations. the few autochthonous cases of chagas disease encountered in espírito santo have been attributed to adult specimens of triatoma vitticeps that invade houses from forest remnants. in recent years, the entomology unit of the espír ... | 2005 | 16184222 |
| treatment of african trypanosomiasis with cordycepin and adenosine deaminase inhibitors in a mouse model. | there is an urgent need to discontinue the use of highly toxic compounds still in use for treatment of the encephalitic stage of human african trypanosomiasis (hat). we show here that intraperitoneal injection of the adenosine analogue cordycepin (3'-deoxyadenosine), together with an adenosine deaminase (ada) inhibitor (coformycin or deoxycoformycin), cures trypanosoma brucei brucei infection in mice. treatment was also effective at a stage when the trypanosomes had penetrated into the brain par ... | 2005 | 16206083 |
| heritable integration of kdna minicircle sequences from trypanosoma cruzi into the avian genome: insights into human chagas disease. | | 2005 | 16220614 |
| risks of blood transfusion and their prevention. | as a result of significant progress in reducing the risks of transfusion-transmitted viral infections, bacterial contamination of platelet components (1:2,000) and sepsis (1:50,000) are now the most frequent infectious complications of blood transfusions. sepsis from bacterial contamination of red cell components is less frequent (1:500,000), because red blood cells, unlike platelet components, can be stored at refrigerated temperatures (1 degrees c-4 degrees c). current risks for transfusion-tr ... | 2003 | 16224428 |
| f(ab')2 antibody fragments against trypanosoma cruzi calreticulin inhibit its interaction with the first component of human complement. | trypanosoma cruzi calreticulin (tccrt), described in our laboratory, retains several important functional features from its vertebrate homologues. we have shown that recombinant tccrt inhibits the human complement system when it binds to the collagenous portion of c1q. the generation of classical pathway convertases and membrane attack complexes is thus strongly inhibited. in most t. cruzi-infected individuals, tccrt is immunogenic and mediates the generation of specific antibodies. by reverting ... | 2005 | 16238097 |
| conversion of trypanosoma cruzi tc52 released factor to a protein inducing apoptosis. | in this study tc52, a trypanosoma cruzi released protein, which exerts an immunoregulatory activity, was converted to a molecular form with altered biological function. indeed, the genetic fusion of tc52 to a carrier protein, the shistosoma japonicum glutathione s-transferase (tc52-sj26), was shown to induce apoptosis in spleen cells from balb/c or cba mice and the human t-cell leukemic cell line (cem). cell death by apoptosis was evidenced by the following criteria: (1) increased binding of ann ... | 2005 | 16246387 |
| itraconazole or allopurinol in the treatment of chronic american trypanosomiasis: the results of clinical and parasitological examinations 11 years post-treatment. | eleven years after they had been given itraconazole or allopurinol for the treatment of chronic american trypanosomiasis, 109 adult patients were checked for electrocardiographic abnormalities and evidence of trypanosoma cruzi infection. the parasitological investigations included xenodiagnosis, in which the faeces of triatoma infestans that had fed on the patients were checked under the microscope for flagellates. in addition, a pcr-based assay and a hybridization assay were used to test blood ... | 2005 | 16297286 |
| trypanosoma cruzi infection induces proliferation of vascular smooth muscle cells. | trypanosoma cruzi infection causes cardiomyopathy and vasculopathy. previous studies have demonstrated that infection of human umbilical vein endothelial and smooth muscle cells resulted in activation of extracellular signal-regulated kinase (erk). in the present study, smooth muscle cells were infected with trypomastigotes, and immunoblot analysis revealed an increase in the expression of cyclin d1 and proliferating cell nuclear antigen (pcna), important mediators of smooth muscle cell prolifer ... | 2006 | 16368968 |
| trypanosoma cruzi trans-sialidase inhibits human lymphocyte proliferation by nonapoptotic mechanisms: implications in pathogenesis and transplant immunology. | chiefly an intracellular parasite, trypanosoma cruzi has a transient blood-borne stage (trypomastigote), the acute phase of chagas' disease, during which surface trans-sialidase is expressed and shed by the parasite. it's immunosuppressive through the induction of apoptosis. herein, we investigated the role of trans-sialidase as an immune modulator of allo- and xenoreactions. trans-sialidase strongly inhibited human lymphocyte proliferation; a role for the interleukin-2 receptor cd25 was suggest ... | 2005 | 16387178 |
| inhibition of trypanosoma cruzi hexokinase by bisphosphonates. | hexokinase is the first enzyme involved in glycolysis in most organisms, including the etiological agents of chagas disease (trypanosoma cruzi) and african sleeping sickness (trypanosoma brucei). the t. cruzi enzyme is unusual since, unlike the human enzyme, it is inhibited by inorganic diphosphate (ppi). here, we show that non-hydrolyzable analogues of ppi, bisphosphonates, are potent inhibitors of t. cruzi hexokinase (tchk). we determined the activity of 42 bisphosphonates against tchk, and th ... | 2006 | 16392806 |
| retinal dysfunction in patients with chronic chagas' disease is associated to anti-trypanosoma cruzi antibodies that cross-react with rhodopsin. | to investigate retinal involvement in chronic chagas' disease, we performed electroretinography and retinal fluorescein angiography studies in chagasic patients. our results demonstrated a dissociated electrophysiological response characterized by both an abnormal reduction of the electroretinographic b-wave amplitude and a delayed latency, under the dark-adaptated condition. these alterations are compatible with a selective dysfunction of the rods. antibodies raised against trypanosoma cruzi th ... | 2006 | 16423878 |
| pneumocystis and trypanosoma cruzi: nomenclature and typifications. | published phylogenetic reclassifications of pneumocystis as a fungus resulted in a nomenclatural shift from the zoological code to the international code of botanical nomenclature. the same may be true for all microsporidians and sundry other organisms. this resulted in the invalidation of names and subsequently precipitated changes to the botanical code to accommodate pneumocystis and microsporidian names. the repercussions following application of the 2005 vienna code to pneumocystis nomenclat ... | 2006 | 16441572 |
| crystal structure, catalytic mechanism, and mitogenic properties of trypanosoma cruzi proline racemase. | amino acid racemases catalyze the stereoinversion of the chiral c alpha to produce the d-enantiomers that participate in biological processes, such as cell wall construction in prokaryotes. within this large protein family, bacterial proline racemases have been extensively studied as a model of enzymes acting with a pyridoxal-phosphate-independent mechanism. here we report the crystal structure of the proline racemase from the human parasite trypanosoma cruzi (tcpraca), a secreted enzyme that tr ... | 2006 | 16446443 |
| [estimation of the parasitemia in trypanosoma cruzi human infection: high parasitemias are associated with severe and fatal congenital chagas disease]. | the aim of this study was to validate the method of microhematocrit tube, as a rapid method to estimate the parasitemia in blood and to associate the parasites concentration with the morbidity and mortality of new born children with congenital chagas diseases. our results were determined experimentally and shown that the detection limit of the microhematocrit tube method is 40 parasites/ml when at least one of the four observed tubes is positive. besides, it was also established that when the fo ... | 2005 | 16482816 |
| stable rna interference of host thrombospondin-1 blocks trypanosoma cruzi infection. | interactions between trypanosoma cruzi and the extracellular matrix play an important role in cellular invasion. here we show that t. cruzi increases the levels of thrombospondin-1 (tsp-1) expression in host cells during early infection. stable rna interference of host cell tsp-1 knocks down the levels of tsp-1 transcripts and protein expression in mammalian cells causing inhibition of t. cruzi infection. addition of tsp-1 to these cells restores infection. thus, host tsp-1, regulated by the par ... | 2006 | 16616140 |
| tcrho1, the trypanosoma cruzi rho homologue, regulates cell-adhesion properties: evidence for a conserved function. | rho proteins are members of the ras superfamily of small gtpases. in higher eukaryotes these proteins play pivotal role in cell movement, phagocytosis, intracellular transport, cell-adhesion, and maintenance of cell morphology, mainly through the regulation of actin microfilaments. the gtpase tcrho1 is the only member of the rho family described in human protozoan parasite trypanosoma cruzi. we previously demonstrated that tcrho1 is actually required for differentiation of epimastigote to trypom ... | 2006 | 16690023 |
| variability of kinetoplast dna gene signatures of trypanosoma cruzi ii strains from patients with different clinical forms of chagas' disease in brazil. | the clinical course of chagas' disease varies widely among different patients and geographic regions. for reasons that are not completely understood but involve host and parasite factors, some patients never develop the disease while others present cardiac and/or gastrointestinal symptoms. many studies have been conducted in order to correlate the genetic variability of the parasites with the clinical forms of the disease, but no conclusive data have been obtained. our research aims at character ... | 2006 | 16757616 |
| variation in trypanosoma cruzi clonal composition detected in blood patients and xenodiagnosis triatomines: implications in the molecular epidemiology of chile. | to identify trypanosoma cruzi clones from chronically infected individuals, they were transferred to triatomines by the xenodiagnosis test (xd) with triatoma infestans. polymerase chain reaction (pcr) and hybridization assays were performed to detect minicircle dna in human blood samples and triatomine feces, using probes to determine the t. cruzi clones present. t. cruzi clone 19 (tci) resulted the most prevalent in humans, with a frequency of 0.70 compared with a frequency of 0.53 in triatomin ... | 2006 | 16760511 |
| are increased frequency of macrophage-like and natural killer (nk) cells, together with high levels of nkt and cd4+cd25high t cells balancing activated cd8+ t cells, the key to control chagas' disease morbidity? | the immunological response during early human trypanosoma cruzi infection is not completely understood, despite its role in driving the development of distinct clinical manifestations of chronic infection. herein we report the results of a descriptive flow cytometric immunophenotyping investigation of major and minor peripheral blood leucocyte subpopulations in t. cruzi-infected children, characterizing the early stages of the indeterminate clinical form of chagas' disease. our results indicated ... | 2006 | 16792677 |
| the controversy on the early history of chagas disease. | recently historians of medicine have proposed three distinctive accounts of early history of chagas disease (american trypasonomiasis). according to the first the disease, described by the brazilian researcher carlos chagas in 1909, was "deconstructed" in the 1920s and disappeared for about twenty years, then was recovered in the 1940s, mainly through the epidemiological studies of emmanuel dias and his colleagues in minas gerais (brazil). according to the second chagas disease could not be "dec ... | 2005 | 16866038 |
| cutting edge: tlr9 and tlr2 signaling together account for myd88-dependent control of parasitemia in trypanosoma cruzi infection. | activation of innate immune cells by trypanosoma cruzi-derived molecules such as gpi anchors and dna induces proinflammatory cytokine production and host defense mechanisms. in this study, we demonstrate that dna from t. cruzi stimulates cytokine production by apcs in a tlr9-dependent manner and synergizes with parasite-derived gpi anchor, a tlr2 agonist, in the induction of cytokines by macrophages. compared with wild-type animals, t. cruzi-infected tlr9(-/-) mice displayed elevated parasitemia ... | 2006 | 16951309 |
| ribose 5-phosphate isomerase type b from trypanosoma cruzi: kinetic properties and site-directed mutagenesis reveal information about the reaction mechanism. | trypanosoma cruzi, the human parasite that causes chagas disease, contains a functional pentose phosphate pathway, probably essential for protection against oxidative stress and also for r5p (ribose 5-phosphate) production for nucleotide synthesis. the haploid genome of the cl brener clone of the parasite contains one gene coding for a type b rpi (ribose 5-phosphate isomerase), but genes encoding type a rpis, most frequent in eukaryotes, seem to be absent. the rpib enzyme was expressed in escher ... | 2007 | 16981853 |
| differential transcription profiles in trypanosoma cruzi associated with clinical forms of chagas disease: maxicircle nadh dehydrogenase subunit 7 gene truncation in asymptomatic patient isolates. | the majority of individuals in the chronic phase of chagas disease are asymptomatic (indeterminate form). every year 2-3% of these individuals develop severe clinical manifestations (cardiac and digestive forms). in this study a trypanosoma cruzi dna microarray was used to compare the transcript profiles of six human isolates: three from asymptomatic and three from cardiac patients. seven signals were expressed differentially between the two classes of isolates, including tryparedoxin, surface p ... | 2006 | 16996148 |
| periurban trypanosoma cruzi-infected triatoma infestans, arequipa, peru. | in arequipa, peru, vectorborne transmission of chagas disease by triatoma infestans has become an urban problem. we conducted an entomologic survey in a periurban community of arequipa to identify risk factors for triatomine infestation and determinants of vector population densities. of 374 households surveyed, triatomines were collected from 194 (52%), and trypanosoma cruzi-carrying triatomines were collected from 72 (19.3%). guinea pig pens were more likely than other animal enclosures to be ... | 2006 | 17073082 |
| human chagasic serum contains antibodies capable of inhibiting trypanosoma cruzi egress from tissue culture cells. | previous studies at our laboratory have shown that an antibody (antiegressin) present in the serum of chronically infected mice is capable of inhibiting the egress of trypanosoma cruzi from infected balb/c fibroblasts. we have used this in vitro system to evaluate whether human chagasic serum is also capable of inhibiting t. cruzi egress. balb/c fibroblasts were infected with tissue culture-derived parasites. five-percent solutions of the individual human serum samples in culture medium were add ... | 2005 | 17089772 |
| [recommendations for diagnosis, treatment and follow-up of the trypanosoma cruzi: human immunodeficiency virus co-infection]. | | 2006 | 17119760 |
| human t-cell lymphotropic virus types i and ii (htlv-i and -ii) infection among seroindeterminate cases in argentina. | human t-cell lymphotropic virus (htlv) seroindeterminate cases have been reported among blood donors (bd) and in at-risk populations worldwide, including argentina. the objective of the present work was to study the presence of htlv-i/ii infection and its association to specific western blot (wb) patterns among healthy bd and at-risk populations in argentina. we analyzed 83 htlv-i/ii seroindeterminate wb cases diagnosed among bd (n = 49) and in different at-risk populations (n = 34) for human re ... | 2007 | 17133550 |
| glycoproteomics of trypanosoma cruzi trypomastigotes using subcellular fractionation, lectin affinity, and stable isotope labeling. | herein we detail the first glycoproteomic analysis of a human pathogen. we describe an approach that enables the identification of organelle and cell surface n-linked glycoproteins from trypanosoma cruzi, the causative agent of chagas' disease. this approach is based on a subcellular fractionation protocol to produce fractions enriched in either organelle or plasma membrane/cytoplasmic proteins. through lectin affinity capture of the glycopeptides from each subcellular fraction and stable isotop ... | 2006 | 17137339 |
| inhibitory effect of umbelliferone aminoalkyl derivatives on oxidosqualene cyclases from s. cerevisiae, t. cruzi, p. carinii, h. sapiens, and a. thaliana: a structure-activity study. | eighteen coumarin derivatives were tested as inhibitors of oxidosqualene cyclases (oscs) from saccharomyces cerevisiae, trypanosoma cruzi, pneumocystis carinii, homo sapiens, and arabidopsis thaliana, all expressed in an osc-defective strain of s. cerevisiae.35 all the compounds have an aminoalkyl chain bound to an aromatic nucleus; unconventional synthetic procedures (microwave- and ultrasound-promoted reactions) were successfully used to prepare some of them. the most interesting structure-dep ... | 2007 | 17154325 |
| predominance of trypanosoma cruzi i among panamanian sylvatic isolates. | trypanosoma cruzi is throughout panama, which is in agreement with the widespread of the sylvatic vectors implicated in the transmission. eco-epidemiological changes in some regions of the country have led to a successful dissemination of the palm-tree attalea butyracea and a possible adaptation of the primary vector of chagas' disease to human settlements. these facts might increase both vector-human contact and human infection with different potentials t. cruzi genotypes and make therefore nec ... | 2007 | 17288977 |
| hitchhiking trypanosoma cruzi minicircle dna affects gene expression in human host cells via line-1 retrotransposon. | the horizontal transfer of trypanosoma cruzi mitochondrial minicircle dna to the genomes of naturally infected humans may play an important role in the pathogenesis of chagas disease. minicircle integrations within line-1 elements create the potential for foreign dna mobility within the host genome via the machinery associated with this retrotransposon. here we document integration of minicircle dna fragments in clonal human macrophage cell lines and their mobilization over time. the movement of ... | 2006 | 17293976 |
| mapping of the distribution of trypanosoma cruzi infection among small wild mammals in a conservation unit and its surroundings (northeast-brazil). | maps are a useful tool that permits correlation of landscapes with hotspots of parasite transmission. here, they were used as a tool for geovisualization to evaluate variables involved in the transmission of trypanosoma cruzi among small wild mammals in an area endemic for chagas disease, the "serra da capivara" national park (parna) and its surroundings in piauí state, northeast brazil. the implementation of a geographical information system (gis) allowed the observation that a previously noted ... | 2007 | 17307027 |
| chagas disease and globalization of the amazon. | the increasing number of autochthonous cases of chagas disease in the amazon since the 1970s has led to fear that the disease may become a new public health problem in the region. this transformation in the disease's epidemiological pattern in the amazon can be explained by environmental and social changes in the last 30 years. the current article draws on the sociological theory of perverse effects to explain these changes as the unwanted result of the shift from the "inward" development model ... | 2007 | 17308715 |
| detection of chagas infections using trypanosoma evansi crude antigen demonstrates high cross-reactions with trypanosoma cruzi. | antigenic similarities between salivarian trypanosomes are known for a long time, but similarities between salivarian and stercorarian trypanosomes have been very little investigated. phylogenetically, these genus and species appear to be far. however, in a preliminary work we had shown strong reactions of chagasic human sera using t. evansi antigens in western-blotting and elisa. in the current work an elisa test using t. evansi crude antigens was probed with one hundred and two sera of chagasi ... | 2007 | 17337255 |
| peridomestic colonization of triatoma longipennis (hemiptera, reduviidae) and triatoma barberi (hemiptera, reduviidae) in a rural community with active transmission of trypanosoma cruzi in jalisco state, mexico. | infestation of peridomiciles is likely a major risk factor for chagas disease transmission in jalisco state, mexico. an entomological and serological survey of a typical village was conducted between july and september 2003. the peridomestic areas of 100 dwellings were visited and triatomines were searched manually in 369 potential sites. a total of 1821 triatoma longipennis (93.2%) or triatoma barberi was captured. both species frequently occurred in sympatry. the infestation index was 60% for ... | 2007 | 17382891 |
| the trypanosoma cruzi pin1 gene encodes a parvulin peptidyl-prolyl cis/trans isomerase able to replace the essential ess1 in saccharomyces cerevisiae. | parvulins are a conserved group of peptidyl-prolyl cis/trans isomerases (ppiases) that catalyze the cis/trans isomerization of proline-preceding peptide bonds. parvulin-class ppiases are structurally unrelated to cyclophilins and fk506-binding proteins that are defined as receptors for immunosuppressive drugs. in trypanosoma cruzi we identified parvulin tcpin1 as a homolog of the human hpin1 ppiase. the 117 amino acids of the tcpin1 display 40% identity with the catalytic core of hpin1 and exhib ... | 2007 | 17418434 |
| thromboxane a2 is a key regulator of pathogenesis during trypanosoma cruzi infection. | chagas' disease is caused by infection with the parasite trypanosoma cruzi. we report that infected, but not uninfected, human endothelial cells (ecs) released thromboxane a(2) (txa(2)). physical chromatography and liquid chromatography-tandem mass spectrometry revealed that txa(2) is the predominant eicosanoid present in all life stages of t. cruzi. parasite-derived txa(2) accounts for up to 90% of the circulating levels of txa(2) in infected wild-type mice, and perturbs host physiology. mice i ... | 2007 | 17420269 |