| [changes in the biopathogenic cycle of trypanosoma cruzi in chronic human and experimental infections]. | | 1969 | 4985414 |
| growth of trypanosoma cruzi in human heart tissue cells and effects of aminonucleoside of puromycin, trypacidin and aminopterin. | | 1969 | 5343467 |
| taxol, a microtubule stabilizing agent, blocks the replication of trypanosoma cruzi. | taxol, an experimental antitumor agent and stabilizer of microtubules, inhibits in vitro replication of the human pathogenic hemoflagellate trypanosoma cruzi. micromolar concentrations of the drug prevent the completion of cell division in these organisms but allow the multiplication of cell organelles such as the nucleus, kinetoplast, and flagellum. the result is the formation of motile organisms that have extra organelles but cannot fully replicate. division proceeds to a relatively fixed locu ... | 1981 | 6117077 |
| trypanosoma cruzi: pattern of rna synthesis following infection of vertebrate cells. | the pattern of rna synthesis of intracellular trypanosoma cruzi amastigotes, immediately following infection of lesch-nyhan human fibroblasts, was studied by autoradiography. amastigote rna synthesis, determined by [3h]guanine incorporation, was not detected until 2 h after infection. at 8 h postinfection more than 90% of intracellular amastigotes were labeled. it was verified that extracellular trypomastigotes also synthesized rna. therefore it was concluded that, if rna is required for trypoma ... | 1980 | 6161248 |
| specific glycoprotein antigens on the surface of insect and mammalian stages of trypanosoma cruzi. | two major surface antigens on trypanosoma cruzi, the causative agent of chagas disease, have been described [nogueira, n., chaplan, s., tydings, j., unkeless, j. & cohn, z. (1981) j. exp. med. 153, 629-639]. one, a mr 75,000 glycoprotein (gp), is specific for the culture forms (insect-host stages) of the organisms--epimastigotes and metacyclic trypomastigotes. the other, a mr 90,000 gp, was found in vertebrate-host stages of the organisms--bloodstream-form trypomastigotes. we now report that the ... | 1982 | 6175966 |
| immunopathogenesis of experimental chagas' disease in mice: damage to the autonomic nervous system. | infection of mice with trypanosoma cruzi produces pathological change which in many ways parallels the evolution of chagas' disease in human patients. an essential element in this experimental pathology is the intense denervation observed during the resolution of acute-stage parasitaemia. host cells, from a variety of tissues, have been shown to absorb parasite antigens and thus to become targets for the hosts' own anti-parasite immune response. the definition of common antigenic determinants, s ... | 1983 | 6196165 |
| the characterization of trypanosoma cruzi stocks by starch-gel electrophoresis, comparison of results with those of isoelectric focusing. | the culture forms of 30 t. cruzi stocks originating from different parts of brazil and venezuela were screened by starch-gel electrophoresis for the isoenzyme patterns of 9 enzymes: glucose-6-phosphate dehydrogenase (g6pd), phosphoglucomutase (pgm), glucosephosphate isomerase (gpi), aspartate aminotransferase (asat), "malic" enzyme (me), alanine aminotransferase (alat), peptidases (pep 1, pep 2) and malate dehydrogenase (mdh). g6pd, pgm, gpi to some extent also asat, me patterns divide 25 stocks ... | 1983 | 6224325 |
| fibronectin enhances macrophage association with invasive forms of trypanosoma cruzi. | treatment of either mouse peritoneal macrophages (mph) or invasive blood forms of trypanosoma cruzi with human plasma fibronectin (fn) significantly enhanced their association (a term to mean surface attachment and parasite internalization) with the untreated counterpart in a dose-dependent manner. this effect involved increases in the percentage of mph that associated with the parasites and in the number of parasites per mph. by using indirect immunofluorescence, the percentages of fn-positive ... | 1984 | 6233374 |
| isozyme heterogeneity and numerical taxonomy of trypanosoma cruzi stocks from chile. | fifty-three stocks of trypanosoma cruzi were isolated in chile, 13 from patients, 32 from the domestic triatomine vector triatoma infestans, and 8 from the silvatic and peridomestic vector t. spinolai. the majority of isolates from triatomine bugs were made by the direct culture of infected faeces. the 53 stocks and a single clone were characterized by a combination of starch-gel and cellulose acetate enzyme electrophoresis. three groups of t. cruzi stocks were apparent from either simple visual ... | 1984 | 6237475 |
| the presence in bolivia of two distinct zymodemes of trypanosoma cruzi, circulating sympatrically in a domestic transmission cycle. | the enzyme profiles of 109 bolivian stocks of trypanosoma cruzi were determined by cellulose acetate electrophoresis using the four enzymes: malate dehydrogenase (oxaloacetate decarboxylating) (nadp+) (e.c.1.1.1.40, me), phosphogluconate dehydrogenase (e.c.1.1.1.44, 6pgdh), phosphoglucomutase (e.c.2.7.5.1, pgm) and glucosephosphate isomerase (e.c.5.3.1.9, gpi). as previously, two principal zymodemes were found sympatrically. both were isolated from man, one appeared to be more frequent at high a ... | 1983 | 6344362 |
| oxygen-dependent microbicidal systems of phagocytes and host defense against intracellular protozoa. | the role of oxygen-dependent microbicidal systems of leukocytes in the host defense against the major nonerythrocytic intracellular protozoa which infect man--toxoplasma gondii, trypanosoma cruzi, and the leishmania species--is reviewed. the hydrogen peroxide-halide-peroxidase microbicidal system is uniformly cidal to these organisms in vitro. peroxidase-independent oxygen product(s) toxicity is more variable. studies to data indicate that phagocytes which contain granule peroxidase and which ha ... | 1983 | 6365936 |
| enhanced multiplication of intracellular (amastigote) stages of trypanosoma cruzi in vitro. | amastigotes of different strains of trypanosoma cruzi responded to stimulation with concanavalin a in an axenic medium by increased dna synthesis and cell multiplication. these effects were inhibited by alpha-methyl mannoside. other mitogens, i.e. phytohemagglutinin p, castor bean ricin type ii isolated from ricinus communis, and a bacterial lipopolysaccharide, had no effect on amastigote growth. amastigote stimulation by concanavalin a lends itself to studies on the biochemistry and cell cycle ... | 1984 | 6389850 |
| heterophil nature of evi antibody in trypanosoma cruzi infection. | previous findings implying the autoreactive capability of circulating complement-fixing (evi) antibodies in patients with chagas' disease (american trypanosomiasis), under both in vitro and in vivo conditions have been irreproducible. the presence of the tissue antigens involved in the reactivity with evi antibodies is exclusively confined to nonhuman substrates, suggesting the heterophil nature of these antibodies which, on the other hand, have also been described in human sera collected in are ... | 1983 | 6409482 |
| enzymatic treatment transforms trypomastigotes of trypanosoma cruzi into activators of alternative complement pathway and potentiates their uptake by macrophages. | in the absence of bound antibody, trypomastigote bloodstream forms of trypanosoma cruzi fail to activate the alternative complement pathway. we now demonstrate that treatment with trypsin and, to a lesser extent, with sialidase converts these protozoa into activators of the pathway, as judged by their lysis in normal sera or sera genetically deficient in fourth or second component of complement (c4 or c2) and their mg2+-dependent consumption of c3 as measured by crossed immunoelectrophoresis. in ... | 1981 | 6454138 |
| pyrazolopyrimidine metabolism in leishmania: an overview. | the demonstration of this unusual metabolic sequence in these organisms indicates that there are substantial differences between these protozoans and their mammalian hosts with respect to pyrazolopyrimidine metabolism. the intracellular forms of l. donovani, which are the pathogenic agents of the human disease, metabolize allopurinol identically. trypanosoma cruzi, the causative agent of american trypanosomiasis, metabolizes allopurinol in the same manner as leishmania; in addition, the intracel ... | 1984 | 6720385 |
| [phagocytosis of the epí and trypomastigote forms of trypanosoma cruzi by peripheral human leukocytes]. | | 1982 | 6763127 |
| anti-trypanosoma cruzi agglutinins in acute human chagas' disease. | | 1980 | 6768314 |
| trypanosoma cruzi (chagas) (protozoa: kinetoplastida) in invertebrate, reservoir, and human hosts of the lower rio grande valley of texas. | | 1980 | 6771371 |
| partial characterization of a trypanosoma cruzi-released decomplementing factor. | trypanosoma cruzi releases a factor (scaf) when grown in vitro which decomplements normal mouse, human, and guinea pig sera. the production and potency of scaf was dependent on the density of cultured parasites, parasite viability and proliferative capacity, and duration of culture. the in vitro interaction between scaf and serum complement (c') occurred rapidly and was complete within 30 min of mixing. the administration of scaf to normal mice resulted in up to 50% reduction in hemolytic c' act ... | 1981 | 6790694 |
| inhibition of antibody-dependent eosinophil-mediated cytotoxicity by heparin. | killing of bloodstream forms of trypanosoma cruzi, the unicellular parasite that causes chagas' disease in humans, by human eosinophils in the presence of specific antibody to the parasite was inhibited by the polyanion heparin in a dose-dependent manner. the concentration of heparin required to completely abolish eosinophil-effected killing of the flagellate increased as the eosinophil to parasite ratio increased. these results suggest that antibody-dependent eosinophil-mediated cytotoxicity is ... | 1982 | 6798115 |
| the direct agglutination test for chronic chagas's disease. the effect of pre-treatment of test samples with 2-mercaptoethanol. | the relative sensitivity and relative specificity of the direct agglutination (da) test for the diagnosis of human trypanosoma cruzi infection were studied in human serum samples, with and without previous treatment with 2-mercaptoethanol (2-me), which were obtained from different areas of brazil. results obtained with these tests were related to those obtained with the indirect immunofluorescence (iif) and indirect haemagglutination (iha) tests. the da test results from the sample not previousl ... | 1981 | 6800073 |
| side effects of immunization with liver attenuated trypanosoma cruzi in mice and rabbits. | immunity against lethal, bloodstream forms of trypanosoma cruzi was achieved in mice by preinoculation of approximately equal to 10(5) culture epimastigotes of an attenuated t. cruzi strain (tcc). the risks of tcc inoculation in terms of pathogenicity or eventual increase in virulence of tcc progeny were evaluated. no pathogenic parasites could be selected from tcc progeny by either mouse, triatome, or culture passages. immunizing doses of live tcc did not induce in adult mice alterations resemb ... | 1982 | 6804389 |
| congenital trypanosoma cruzi infection in a laboratory-born squirrel monkey, saimiri sciureus. | a colombian phenotype, laboratory-born squirrel monkey, saimiri sciureus, was found to be congenitally infected with biologically proven trypanosoma cruzi. the parasite was observed in blood smears and by xenodiagnoses of the mother and the offspring, and the isolates produced infection in mice and amastigotes in vero tissue culture cells. the finding was accidental; both animals were healthy. tissues of the mother did not show macro-microscopic evidence of t. cruzi infection and the electrocard ... | 1982 | 6812444 |
| trypanosoma cruzi: sequence of phagocytosis and cytotoxicity by human polymorphonuclear leucocytes. | we have studied the relationship between phagocytosis and cytotoxicity of human polymorphonuclear leucocytes (pmn) to sensitized trypanosoma cruzi. assays were done simultaneously using [3h]-uridine labelled epimastigotes as target cells. phagocytosis was evaluated by the uptake and cytotoxicity by the release of parasite associated [3h]-uridine. both reactions reached maximum levels at the same effector- to target-cell ratio and antibody concentration. uptake of epimastigotes by pmn was highest ... | 1981 | 7016743 |
| phagocytosis of trypanosoma cruzi by human polymorphonuclear leukocytes. | phagocytosis of culture forms of trypanosoma cruzi was assayed by a radioisotopic method. purified polymorphonuclear leukocytes (pmn) were mixed with 3h-uridine-labeled t. cruzi epimastigotes in the presence or absence of anti-t. cruzi antibodies. the reaction was stopped by adding n-ethyl-maleimide, and noningested parasites were lysed by complement. the percentage of radioactivity incorporated into the pmn pellet was recorded. the phagocytosis reaction was rapid, yielding maximum incorporation ... | 1981 | 7031233 |
| immune response in human chagas disease ii. lymphocyte blastogenesis in patients with chagasic cardiomyopathy. | | 1980 | 7034436 |
| density gradient purification of human lymphocytes from contaminating trypomastigotes of trypanosoma cruzi. | mixtures of normal human lymphocytes and t. cruzi trypomastigotes obtained from infected mice were centrifuged over ficoll-hypaque (fh) continuous and discontinuous gradients. trypomastigotes were confined to the range 1.051-1.057 g/ml while lymphocytes ranged between 1.046 and 1.080 g/ml. over 80% of the lymphocytes were found at 1.060 g/ml or higher densities. a discontinuous gradient of fh with 2 layers of 1.060 and 1.077 g/ml of density respectively was selected to obtain trypomastigotes-fre ... | 1982 | 7047646 |
| the epidemiological importance of triatoma nigromaculata (stal, 1859) colonizing human dwellings of the venezuelan andes. | | 1994 | 7476214 |
| antigens shared by leishmania species and trypanosoma cruzi: immunological comparison of the acidic ribosomal p0 proteins. | patients with visceral leishmaniasis produce high levels of immunoglobulin, but the specificities of antibodies produced are not well characterized. in an effort to identify leishmania antigens that are specific to leishmania species or are cross-reactive with other parasitic protozoa, we have cloned and characterized full-length genomic and cdna clones encoding a leishmania chagasi acidic ribosomal antigen, lcp0, recognized during human infections. the protein is homologous to the trypanosoma c ... | 1994 | 7513304 |
| characterization of the plasma-membrane calcium pump from trypanosoma cruzi. | despite previous reports [mclaughlin (1985) mol. biochem. parasitol. 15, 189-201; ghosh, ray, sarkar and bhaduri (1990) j. biol. chem. 265, 11345-11351; mazumder, mukherjee, ghosh, ray and bhaduri (1992) j. biol. chem. 267, 18440-18446] suggesting that the plasma-membrane ca(2+)-atpases of different trypanosomatids differ from the ca2+ pumps present in mammalian cells, trypanosoma cruzi plasma-membrane ca(2+)-atpase shares several characteristics with the ca2+ pumps present in other systems. thi ... | 1995 | 7532400 |
| autoimmunity in chagas disease cardiopathy: biological relevance of a cardiac myosin-specific epitope crossreactive to an immunodominant trypanosoma cruzi antigen. | heart tissue destruction in chronic chagas disease cardiopathy (ccc) may be caused by autoimmune recognition of heart tissue by a mononuclear cell infiltrate decades after trypanosoma cruzi infection. indirect evidence suggests that there is antigenic crossreactivity between t. cruzi and heart tissue. as there is evidence for immune recognition of cardiac myosin in ccc, we searched for a putative myosin-crossreactive t. cruzi antigen. t. cruzi lysate immunoblots were probed with anti-cardiac myo ... | 1995 | 7536937 |
| trypanosoma and leishmania have clonal population structures of epidemiological significance. | this paper presents three results concerning the population structure of trypanosoma cruzi, the agent of chagas disease: (1) the mode of propagation of t. cruzi in nature is clonal; sexual reproduction is either totally absent or so rare that it leaves no traces in the population structure of the parasite. (2) the genetic diversity of the clonal lineages is large: extant t. cruzi represent lineages of descent that have evolved independently for long time spans (up to 40 million years). (3) some ... | 1993 | 7545504 |
| [increase of hofbauer cells in human placentas cocultured in vitro with trypanosoma cruzi]. | to analyze the interaction between normal human placentas with trypanosoma cruzi, optical and electron microscopy of chorionic villi stroma cocultured in vitro with 1.5 x 106 tulahuen strain trypomastigotes of the t. cruzi for 1 h, 3 hs and 12 hs in eagle minimal essential medium were done. an agglutination of chorionic villi in experimental cultures (with t. cruzi) from 1 h cultures was observed that was not present in control ones. this phenomenon resisted soft mechanical agitation to separate ... | 1994 | 7597283 |
| presence of histone h2b in trypanosoma cruzi chromatin. | the organization of chromatin in protists presents some characteristic features. in trypanosoma cruzi, no condensation of chromatin into chromosomes is observed during cell division. a systematic characterization of histones should provide information on this peculiar behaviour. histone h2b from this parasite was characterized by selective dissociation from chromatin in 0.8 m nacl, by its elution pattern in narrow-bore reversed phase high performance liquid chromatography, by polyacrylamide gel ... | 1993 | 7670546 |
| prevalence of anti-hepatitis c virus in the blood donor population of rio de janeiro. | the prevalence of hepatitis c virus (hcv) antibodies in 2,557 asymptomatic volunteer brazilian blood donors is reported. using the line immunoassay (inno-lia) as a confirmatory test on elisa anti-hcv-positive reacting sera, a prevalence rate of 2.7% for anti-hcv positivity was found. by comparison, prevalences of 1.6% for hepatitis b surface antigen, 0.9% for treponema pallidum, 0.4% for human immunodeficiency virus and 0.04% for trypanosoma cruzi were observed. only 57% of the hcv-positive dono ... | 1993 | 7692672 |
| polymerase chain reaction detection of trypanosoma cruzi in human blood samples as a tool for diagnosis and treatment evaluation. | trypanosoma cruzi specific sequences were amplified by the polymerase chain reaction from total blood of human chagasic patients and normal individuals. a 330 bp fragment originating from kinetoplast dna was specifically detected in most chagasic individuals. we tested the sensitivity and specificity of this method in normal and affected individuals attending the evandro chagas hospital, rio de janeiro. the results of these tests were compared with serological diagnosis performed using standard ... | 1995 | 7724232 |
| molecular and cytotoxic effects of camptothecin, a topoisomerase i inhibitor, on trypanosomes and leishmania. | parasites pose a threat to the health and lives of many millions of human beings. among the pathogenic protozoa, trypanosoma brucei, trypanosoma cruzi, and leishmania donovani are hemoflagellates that cause particularly serious diseases (sleeping sickness, chagas disease, and leishmaniasis, respectively). the drugs currently available to treat these infections are limited by marginal efficacy, severe toxicity, and spreading drug resistance. camptothecin is an established antitumor drug and a wel ... | 1995 | 7731973 |
| chagas' disease in the brazilian amazon. i--a short review. | at least eighteen species of triatominae have been found in the brazilian amazon, nine of them naturally infected with trypanosoma cruzi or "cruzi-like" trypanosomes and associated with numerous wild reservoirs. despite the small number of human cases of chagas' disease described to date in the brazilian amazon the risk that the disease will become endemic in this area is increasing for the following reasons: a) uncontrolled deforestation and colonization altering the ecological balance between ... | 1994 | 7732267 |
| molecular and immunological characterization of a trypanosoma cruzi protein homologous to mammalian elongation factor 1 gamma. | in previous studies, we reported the characterization of three trypanosoma cruzi proteins with molecular masses of 45, 30 and 25 kda eluted from a glutathione agarose column (these proteins were named tcgbp). using antibodies against tcgbp native proteins we could isolate from a lambda zapii epimastigote cdna library cdna clones encoding the 30 and 25 kda proteins. comparison of the two sequences with amino acid sequences in several data banks revealed that both protein sequences were highly hom ... | 1994 | 7735118 |
| antigenicity of cystatin-binding proteins from parasitic protozoan. detection by a proteinase inhibitor based capture immunoassay (pinc-elisa). | a novel immunoassay (pinc-elisa) was designed using proteinase inhibitors of the cystatin superfamily (pinc) in the solid phase, to promote the selective capture of cysteine proteinases. the method was applied in the identification of papain-like antigens from parasitic protozoa. pinc of human origin, namely recombinant cystatin c (r-cystatin c) or low molecular weight kininogen were used in the assays to adsorb proteases contained in cell lysates from various trypanosomatids. the pinc-elisa was ... | 1995 | 7769245 |
| activation-induced cd4+ t cell death by apoptosis in experimental chagas' disease. | infection of mice with trypanosoma cruzi, the causative protozoan agent of human chagas' disease, leads to immunosuppression of the t cell compartment and to chronic cardiac inflammation which resembles the human infection. recently, reinduction of programmed cell death by apoptosis in mature t cells has been demonstrated. it has been suggested that mature t cell apoptosis could play a role in immunosuppression caused by virus infection. in this report, we have investigated the occurrence of mat ... | 1995 | 7814881 |
| infection characteristics of an ecuadorian trypanosoma cruzi strain with reduced virulence. | a human isolate of trypanosoma cruzi obtained from guayaquil, ecuador (guayas strain) was examined for its infectivity of the resistant c57bl/6 (b6) and the susceptible c3h (he) mouse strains and compared to infection with the known virulent brazil strain. c3h mice were capable of surviving acute guayas infection, whereas the brazil infection was fatal for this mouse strain. both c3h and b6 mice showed a greatly reduced (over 10-fold) parasitemia during guayas infection compared to brazil infect ... | 1995 | 7876970 |
| [reactivity of sera from chagas patients to extracts of mexican trypanosoma cruzi isolates]. | an antigenic extract prepared from four different mexican isolates of trypanosoma cruzi cultured on bhi (three came from human cases-agripina, fidelfa and ninoa, and other from triatoma-cocula) were assayed with human sera. elisa results always were consistent with clinical diagnosis. sera from patients with a diagnosis of chagas disease were reactive and non-chagasic sera were negative. western blot of chagasic sera recognized antigens of molecular weight > 81 kd, 81 kd, 54 kd, 42 kd, and 26 kd ... | 1993 | 7886259 |
| presence of antiheart and antiskeletal muscle glycolipid autoantibodies in the sera of patients with chagasic cardiopathy. | to characterize biochemically and isolate the skeletal and heart muscle cell epitope recognized by the autoantibodies present in the serum of chronically infected trypanosoma cruzi patients. secondly, to use that epitope in an immunoenzymatic assay for determining differences in antibody titre among chagas' and other protozoan and heart diseases and between asymptomatic and cardiopathic chagasic patients. | 1994 | 7922834 |
| [effects of monoclonal antibodies on phagocytosis of entamoeba histolytica to human erythrocytes]. | two monoclonal antibodies 3f7 and 4g6 were produced respectively against plasma membrane and nucleus-cytoplasm of entamoeba histolytica. the erythrocytophagous quantification and ability of pathogenic strain hm-1:imss were evaluated by microscopy immediately at 5 min and 10 min after incubation with mcab 3f7 and mcab 4g6. sera from normal mice and monoclonal antibody tce 04 against trypanosoma cruzi were prepared as negative controls. the mcab 3f7 showed stronger inhibitory action on the erythro ... | 1994 | 7955164 |
| trypanosoma cruzi infection suppresses nuclear factors that bind to specific sites on the interleukin-2 enhancer. | interleukin-2 (il-2) gene expression, a critical early event during t lymphocyte activation, is severely suppressed in mice infected with the protozoan parasite trypanosoma cruzi, the causative agent of human chagas' disease. our previous observation that reduction of il-2 mrna in t cells from t. cruzi-infected mice is not due to an increased degradation of the mrna suggests a repression of the il-2 gene at the transcriptional level. in this study, we have measured the level of nuclear factors t ... | 1994 | 8020551 |
| randomly amplified polymorphic dna (rapd) and isoenzyme analysis of trypanosoma rangeli strains. | sixteen trypanosoma rangeli strains were compared by isoenzyme and randomly amplified polymorphic dna (rapd) analysis. eight strains were isolated from either rhodnius prolixus or homo sapiens from honduras, colombia and venezuela. another eight strains were isolated from either panstrongylus megistus or the rodent echimys dasythrix from the state of santa catarina, southern brazil. all six t. rangeli strains isolated from p. megistus were co-infections with trypanosoma cruzi, demonstrating an o ... | 1994 | 8049688 |
| [detection of trypanosoma cruzi in experimental samples by the dna polymerase chain reaction method]. | chagas' disease (american trypanosomiasis) affects more than 20 million people in latin america. almost 30% of those people may develop a chronic disease, which is expressed mainly as a chronic chagasic cardiopathy (ccc). recent studies in mexico have shown that 40% of patients suffering dilated cardiomyopathy do have serum antibodies against trypanosoma cruzi. it is well known the difficulties of parasitologic diagnosis of ccc, which in less extent does exist for serologic diagnosis. here we re ... | 1994 | 8074585 |
| hydroxyurea-induced synchrony of dna replication in the kinetoplastida. | we have developed a reliable and reproducible method to induce synchrony of the dna synthetic cycle in the kinetoplastida. the method involves treatment of cultures with 20 mm hydroxyurea (hu) and fetal bovine serum. both stationary-phase and exponential-phase cultures can be synchronized. however, in the case of exponential-phase cultures the population doubling time and rate of dna synthesis of the population influenced the time of exposure to hu. the treatment of kinetoplastids with 20 mm hu ... | 1994 | 8082726 |
| isolation and characterization of a gene from trypanosoma cruzi encoding a 46-kilodalton protein with homology to human and rat tyrosine aminotransferase. | the complete sequence of a gene encoding a 46-kda protein of trypanosoma cruzi is presented. the first atg complies with the consensus sequence for initiation of translation. a single band of 2 kb was highlighted by hybridizing a probe from the 46-kda protein gene to a northern filter containing total t. cruzi rna. the gene is present in 50-80 copies per cell and most of them are contained in 2 tandem arrays on large t. cruzi chromosomes (> 2000 kb). a strong homology with rat and human tyrosine ... | 1993 | 8101971 |
| anti-heart tissue antibodies during experimental infections with pathogenic and non-pathogenic trypanosoma cruzi isolates in dogs. | dogs infected with a pathogenic trypanosoma cruzi isolate (tc-o), or a non-pathogenic isolate (tc-d) developed low antinuclear antibody titers throughout 240 days of infection. dogs infected with tc-o, but not tc-d, produced anti-heart tissue antibodies (as measured by an elisa) throughout infection. antibody levels were highest immediately after the acute stage of infection (30 days post-inoculation--dpi) when myocardiocyte destruction was at its greatest. antibody levels progressively declined ... | 1993 | 8106190 |
| improved enzyme-linked immunoadsorbent assay (elisa) for the study of trypanosoma cruzi-host cell interaction in vitro. | we herein present an improved assay for detecting the presence of trypanosoma cruzi in infected cultures. using chagasic human sera (chs), we were able to detect t. cruzi infection in primary cultures of both peritoneal macrophages and heart muscle cells (mhc). to avoid elevated background levels--hitherto observed in all experiments especially in those using hmc--chs were preincubated with uninfected cells in monolayers or suspensions prior to being used for detection of t. cruzi in infected mo ... | 1993 | 8107584 |
| quantitation of the interaction of the immunosuppressant deoxyspergualin and analogs with hsc70 and hsp90. | deoxyspergualin (dsg), a spermidinyl, alpha-hydroxyglycyl, 7-guanidinoheptanoyl peptidomimetic, shows immunosuppressive activity. in confirmation of a recent report that immobilized methoxydsg selectively retains the heat shock protein hsc70, we report here quantitative binding of dsg and analogs to both hsc70 and the 90-kda heat shock protein hsp90. we have utilized affinity capillary electrophoresis to obtain kd values for dsg and analogs, and stimulation of the atpase activity of hsc70 to obt ... | 1994 | 8117717 |
| the surface trans-sialidase family of trypanosoma cruzi. | trypanosomes cannot synthesize sialic acids. infectious stages of the life cycle of the human pathogen trypanosoma cruzi express a cell-surface glycolipid-anchored trans-sialidase, which can transfer sialic acid between glyco-conjugates. sialic acid is transferred from host cell-surface and serum sialylglycoproteins to trypanosome cell-surface glycoconjugates. the transfer reaction is specific for donors with terminal alpha-2,3-linked sialic acid, and terminal beta-1,4-linked galactose is the pr ... | 1993 | 8257103 |
| genetic structure of trypanosoma cruzi populations from argentina estimated from enzyme polymorphism. | isolates of trypanosoma cruzi from human patients, domestic and sylvatic animals and vector insects were obtained in different areas of argentina. electrophoretic patterns of enzymes from extracts of 95 isolates were analysed. on the basis of zymograms providing information on 10 loci, 12 zymodemes are described according to their genotypes. data presented show fixed heterozygosity, absence of segregation of genotypes, significant departures from hardy-weinberg equilibrium, and over-represented ... | 1993 | 8278220 |
| n-glycosylation in trypanosomatid protozoa. | trypanosomatid protozoa are parasites of considerable medical and economic importance in developing countries. the pathway leading to n-glycosylation in these microorganisms is characterized by the following features: (i) dolichols are composed of only 10-13 isoprene units; (ii) oligosaccharides transferred in n-glycosylation have the compositions man(6,7,9)glcnac2, depending on the species; (iii) trypanosomatids are unable to synthesize dolichol-p-glc and, in addition, some species lack certain ... | 1993 | 8358146 |
| characterization of responses of normal human t cells to trypanosoma cruzi antigens. | the stimulation of normal human pbmc by trypanosoma cruzi ag was analyzed. pbmc showed significant in vitro proliferation in response to parasite lysate (tct), with stimulation indices ranging from 10 to 400, peaking at 6 to 7 days. the cells stimulated with tct produced significant levels of il-2. to determine which cells proliferated in response to tct, pbmc were separated into t- and b-enriched cell populations. purified t cells, but not b cells, proliferated strongly to tct. the t cell respo ... | 1993 | 8423347 |
| cognitive impairment and autoantibodies in systemic lupus erythematosus. | nervous system involvement in systemic lupus erythematosus (sle) includes a wide array of manifestations some of which have been associated with specific autoantibodies. these include reactivity to surface neuronal and lymphocyte antigens, ribosomal p and cardiolipin. the aim of the present study was to examine the association between cognitive abnormalities and these autoantibodies in an unselected female population of sle patients. using a battery of standardized neuropsychological tests, cogn ... | 1993 | 8461922 |
| trypanosoma cruzi: characterization of two recombinant antigens with potential application in the diagnosis of chagas' disease. | a genomic library of trypanosoma cruzi, constructed in the vector lambda gt11, was screened with a hyperimmune rabbit antiserum against tissue culture trypomastigotes. two clones, b12 and b13, containing inserts of 350 and 600 bp, respectively, were isolated. sequencing data indicated that both clones present a pattern of tandemly repeated nucleotide units of 60 bp for b12 and 36 bp for b13. southern blot analysis suggests that both corresponding genes exist as a single copy. the inserts of both ... | 1993 | 8467895 |
| amplification of a trypanosoma cruzi dna sequence from inflammatory lesions in human chagasic cardiomyopathy. | the major cause of morbidity and mortality in chagas' disease is a chronic inflammatory cardiomyopathy, which presents ten or more years following initial infection. demonstration of trypanosoma cruzi in cardiac tissue by routine microscopy or culture is difficult in these patients, which has suggested that persistent organisms are not required for chronic disease. consequently, studies have focused on elucidating an autoimmune pathogenesis of chronic injury. to further assess the persistence of ... | 1993 | 8470772 |
| autoantibodies in chagas' disease. an antibody cross-reactive with human and trypanosoma cruzi ribosomal proteins. | sera from 102 patients with chronic chagas' disease were studied for the presence of autoantibodies to intracellular proteins and nucleic acids by three different methods. only four sera had autoantibodies detected by indirect immunofluorescence on hep-2 cells. all of the sera were negative for anti-dsdna, anti-ro/ssa, anti-la/ssb, anti-sm and anti-rnp autoantibodies but 12 (12%) of the sera had low to moderate levels of anti-histone antibodies. when chagas sera were tested for autoantibodies to ... | 1993 | 8473740 |
| the action of trypanosoma cruzi trans-sialidase on glycolipids and glycoproteins. | addition of sialic acid residues in the human pathogen trypanosoma cruzi glycoconjugates is mediated by a trans-sialidase and not by a cmp-sialic acid:glycoconjugate sialyltransferase. incubation of trans-sialidase with n-[galactose-14c]acetyllactosamine and o-linked oligosaccharides, n-linked glycopeptides (both obtained from fetuin) or sialyllactose showed that the last three compounds were donors of sialic acid residues to the first one. moreover, n- and o-linked oligosaccharides in asialofet ... | 1993 | 8477749 |
| congenital chagas' disease: diagnostic and clinical aspects. | the diagnostic and clinical aspects of congenital chagas' disease were studied in 71 children in buenos aires. the children's ages ranged from 2 days to 10 years. in infants < 6 months old, the disease was diagnosed by detection of trypanosoma cruzi in the blood; the microhematocrit test was positive in 38 (97.4%) of 39 cases. this test was the fastest and most reliable diagnostic method in this group, whereas two conventional serological methods were useful in children > or = 6 months of age. f ... | 1995 | 8527542 |
| modification of cholinergic-mediated cellular transmembrane signals by the interaction of human chagasic igg with cardiac muscarinic receptors. | the possible role of altered humoral immunity in cardiac chagas' disease was examined by analyzing the interaction of igg and the corresponding f(ab')2 from trypanosoma cruzi-infected patients with cardiac muscarinic cholinergic receptors (machr). human chagasic igg and its f(ab')2 simulated the agonist actions triggering the biological effects associated with cholinergic-mediated cellular transmembrane signals, i.e. stimulation of cgmp, inhibition of camp and a decrease in atrial contractility. ... | 1994 | 8528894 |
| flow cytometry, a new approach to detect anti-live trypomastigote antibodies and monitor the efficacy of specific treatment in human chagas' disease. | sera from patients chronically infected with trypanosoma cruzi display antibodies that bind to epitopes of living trypomastigotes, known as lytic antibodies (la), and are detected by a complement-mediated lysis test. conventional serology antibodies (csa) are also present in sera from patients with chronic infections but, in contrast to la, are unable to recognize viable trypomastigotes. the presence of la has been used as an important element in the criterion of cure in human chagas' disease. u ... | 1995 | 8548536 |
| characterization of t cell clones from chagasic patients: predominance of cd8 surface phenotype in clones from patients with pathology. | human chagas' disease, caused by the protozoan trypanosoma cruzi, is associated with pathological processes whose mechanisms are not known. to address this question, t cell lines were developed from chronic chagasic patients peripheral blood mononuclear cells (pbmc) and cloned. these t cell clones (tcc) were analyzed phenotypically with monoclonal antibodies by the use of a fluorescence microscope. the surface phenotype of the tcc from the asymptomatic patient were predominantly cd4 positive (86 ... | 1995 | 8551952 |
| impairment of monocytic function during trypanosoma cruzi infection. | during acute infection, trypanosoma cruzi, the etiologic agent of chagas' disease, causes immunosuppression by mechanisms that are not fully delineated. since mononuclear phagocytes are major target cells in trypanosomiasis, we investigated monocytic function during acute t. cruzi infection. a series of human monocyte and macrophage hybridomas, which represent clonal expansions of subpopulations of human macrophages and possess many normal monocytic functions, were successfully infected with t. ... | 1994 | 8556525 |
| histone h1 and core histones in leishmania and crithidia: comparison with trypanosoma. | the trypanosomatidae family is characterized by flagellated protozoa presenting a kinetoplast. several genera of this family contain species that are pathogenic to man and domestic animals. their chromatin is not condensed into chromosomes during cell division. as a contribution to the understanding of basic aspects of their genome organization, we present a systematic characterization of the histones from three genera of the trypanosomatidae family. crithidia fasciculata and leishmania mexicana ... | 1996 | 8612672 |
| probability of infection with trypanosoma cruzi of the vector triatoma infestans fed on infected humans and dogs in northwest argentina. | the probability that an uninfected triatoma infestans would become infected with trypanosoma cruzi after a single feed on people or dogs seropositive for t. cruzi was estimated in amama, a rural village in northwest argentina where transmission had resurged four years earlier. the prevalence of seropositivity for t. cruzi was 34.2% among 225 people tested, and 65.1% among 83 dogs tested. parasitemia was detected by xenodiagnosis in 29.3% of 41 seropositive persons and in 85.3% of 34 seropositive ... | 1996 | 8702018 |
| [presence of triatoma spinolai in human dwellings]. | triatoma spinolai is a wild species of triatomine existing exclusively in chile, with scarce epidemiological importance in the transmission of trypanosoma cruzi to man. it has been found in environments from 3000 meters down to the sea level. exceptionally it has been found in human dwellings. in order to clarify the possibility of an adaptation of t. spinolai to human dwellings a study was undertaken in 50 rural-periurban dwellings from regions iii, iv, v and metropolitan in which this triatomi ... | 1995 | 8762671 |
| [epidemiology of chagas disease in chile. frequency of human trypanosoma cruzi infection by age groups and regions]. | chagas' disease is endemic in rural-periurban sections of the northern half of chile which includes the first seven political-administrative regions of the country (18 degrees 30'-34 degrees 36' south lat.). data concerning to the results of an indirect hemagglutination test for chagas' disease performed to 15,418 rural-periurban and 45,119 urban inhabitants fron the chagasic endemic regions are presented. migrations from rural-periurban to urban areas have contributed to the dissemination of tr ... | 1995 | 8762673 |
| characterization of two isolates of trypanosoma cruzi obtained from the patient berenice, the first human case of chagas' disease described by carlos chagas in 1909. | two isolates of trypanosoma cruzi were obtained from the patient berenice, the first human case of chagas' disease (chagas 1909), when she was 55 and 71 years old, respectively. the isolates were characterized on the basis of their epimastigote-trypomastigote differentiation in liquid media and of the electrophoretic pattern of ecor1 digestion products of kinetoplast dna (k-dna) minicircles (schizodeme) and isoenzyme patterns (zymodeme). clear differences were found between the isolates, suggest ... | 1996 | 8801560 |
| new trends in chemotherapy on human and animal blood parasites. | blood-parasite protozoa are causative agents of some of the major tropical or infectious diseases for humans and animals, such as plasmodium for malaria (about 270 million infected people), trypanosoma cruzi for chagas' disease (about 18-20 million individuals), african trypanosomes for human and bovine trypanosomiasis, and babesia for cattle and dogs. the absence of efficient vaccines against these diseases, the absence or the high toxicity of the few drugs against american and african trypanos ... | 1996 | 8801568 |
| biotin-labelled peptidyl diazomethane inhibitors derived from the substrate-like sequence of cystatin: targeting of the active site of cruzipain, the major cysteine proteinase of trypanosoma cruzi. | biotin-labelled peptidyl diazomethane inhibitors of cysteine proteinases, based on the n-terminal substrate-like segment of human cystatin c, a natural inhibitor of cysteine proteinases, were synthesized. these synthetic derivatives were tested as irreversible inhibitors of cruzipain, the major cysteine proteinase of trypanosoma cruzi, to compare the kinetics of the inhibition of the parasite proteinase with that of the mammalian cathepsins b and l. the accessibility of the active sites of these ... | 1996 | 8809025 |
| a putative pyruvate dehydrogenase alpha subunit gene from trypanosoma cruzi. | a full-length dna clone encoding a putative pyruvate dehydrogenase alpha subunit (e1 alpha) gene was isolated from a trypanosoma cruzi (ra strain) dna library. sequencing of this clone revealed it to encode a 378 amino acid protein (m(r) 42774) with high sequence similarity to e1 alpha obtained from different sources. the highest score is obtained with human e1 alpha: 43,3% similarity. southern blot analysis is consistent with the existence of a single copy of this putative t. cruzi e1 alpha gen ... | 1996 | 8950176 |
| structural variation in the glycoinositolphospholipids of different strains of trypanosoma cruzi. | the structures of the glycoinositolphospholipids (gipls) from five strains of the protozoan parasite trypanosoma cruzi have been determined. two series of structures were identified, all but one containing the same man4(aep)glcn-ins-po4 core. series 1 oligosaccharides are substituted at the third mannose distal to inositol (man 3) by ethanolamine-phosphate or 2-aminoethylphosphonic acid, as are some glycosyl-phosphatidylinositol-protein anchors of t. cruzi. the core can be further substituted by ... | 1996 | 8981087 |
| soluble cell adhesion molecules in human chagas' disease: association with disease severity and stage of infection. | formation of inflammatory lesions, one of the pathologic consequences of infection with trypanosoma cruzi, involves intricate cell-cell interactions in which cell adhesion molecules (cams) are involved. sera from 56 chagas' disease patients grouped according to disease severity were studied for the presence of soluble intercellular adhesion molecule-1 (s-icam-1), soluble endothelial selectin (s-e-selectin), soluble vascular cell adhesion molecule-1 (s-vcam-1), soluble platelet selectin (s-p-sele ... | 1996 | 9025689 |
| trypanosomiasis. | african (sleeping sickness) and american (chagas' disease) trypanosomiasis, caused by protozoa of the family trypanosomatidae, are diseases that are endemic in parts of africa and latin america, respectively. physicians in developed countries may occasionally see cases because of extensive travel and immigration from endemic countries. although neurological involvement is common in both, its incidence and clinical presentation differ considerably. african trypanosomiasis, caused by subspecies of ... | 1997 | 9034568 |
| trypanosoma cruzi: specific detection of parasites by pcr in infected humans and vectors using a set of primers (bp1/bp2) targeted to a nuclear dna sequence. | in the present work we evaluate trypanosoma cruzi dna detection by pcr using the nuclear oligonucleotides bp1/bp2 as primers. these primers are targeted to the 5' and 3' ends of the coding region for the flagellar protein f29. an amplification product of bp1/bp2 is a dna band 692 bp long. titration assays were performed to evaluate the minimum amount of parasite dna that can be detected by this assay, resulting in 10 fg (equivalent to about 1/20 of the genome). the assay was also performed using ... | 1997 | 9085919 |
| leishmania major: molecular cloning, sequencing, and expression of the heat shock protein 60 gene reveals unique carboxy terminal peptide sequences. | heat shock proteins (hsp) in the size range of m(r) 60,000 are major targets of the immune response in vivo. the leishmania heat-inducible proteins of m(r) 65-67,000 are expressed at relatively high levels in infected macrophages (infection and immunity 1993, 61, 3265-3272) and may be important targets of the host response. to facilitate further studies concerned with these proteins, the hsp60 gene of leishmania major was cloned, sequenced, and expressed. a lambdaembl-3 l. major genomic library ... | 1997 | 9085922 |
| recognition of an immunogenetically selected trypanosoma cruzi antigen by seropositive chagasic human sera. | if the h-2 congenic mouse strains a.sw (h-2n) and a.ca (h-2f), are infected with trypanosoma cruzi, a 45 kda protein (tc45), present in cultured epimastigotes and blood trypomastigotes, is recognized only by the a.sw strain sera. in order to explore the possibility that among seropositive humans the response to tc45 is also highly variable, 81 chagasic human sera (as defined by the hemave agglutination test, polychaco s.a.i.c., buenos aires, argentina) were tested in a direct (epimastigote antig ... | 1997 | 9088429 |
| heart muscle cells share common neutral glycosphingolipids with trypanosoma cruzi. | neutral glycosphingolipids were isolated from mouse heart muscle cells and their structures were analyzed. the molecular compositions of these glycosphingolipids were examined using column chromatography, hptlc, gc-ms and fast atom bombardment-mass spectrometry (fab-ms). monohexosylceramides are a mixture of glucosyl- and galactosylceramides in a ratio of 1:1, sphingosine as the long chain base and as fatty acyl groups mainly c16, c18 saturated and c22 and c24 hydroxy fatty acids. dihexosylceram ... | 1997 | 9107361 |
| characterization of the substrate specificity of the major cysteine protease (cruzipain) from trypanosoma cruzi using a portion-mixing combinatorial library and fluorogenic peptides. | the substrate specificity of the major cysteinyl proteinase of the parasitic protozoan trypanosoma cruzi (cruzipain) was investigated, by combinatorial replacement of amino acid residues at positions p5-p'5, using a fluorescent quenched solid-phase library assay. positively charged residues appear to be a general preference in the p5-p3 and the p'5-p'3 positions, while a hydrophobic residue was always required at the p2 position. a broad range of amino acids could be accepted at the p'1 position ... | 1997 | 9163334 |
| cross-reactivity of antibodies in human infections by the kinetoplastid protozoa trypanosoma cruzi, leishmania chagasi and leishmania (viannia) braziliensis. | we have detected antibodies, in the sera of chagas disease, kala-azar and mucocutaneous leishmaniasis patients, that bind multiple antigens shared between the three causative agents. the chagas disease sera showed 98 to 100% positive results by elisa when the leishmania braziliensis and leishmania chagasi antigens were used, respectively. the kala-azar sera showed 100% positive results with trypanosoma cruzi or l. braziliensis antigens by immunofluorescence assays. the antibodies in the sera of ... | 1996 | 9163981 |
| association of an increase in cd8+ t cells with the presence of trypanosoma cruzi antigens in chronic, human, chagasic myocarditis. | the role of trypanosoma cruzi in the pathogenesis of myocarditis in the chronic phase of chagas' disease is still controversial, with autoimmune mechanisms frequently being proposed. in the present work, we demonstrate that higher numbers of cd8+ t cells are correlated with the presence of parasite antigens, suggesting an important role for the parasite in the development of myocardial inflammation. quantification of the mean numbers of cd8+ and cd4+ t cells per 400x microscopic field was perfor ... | 1997 | 9180594 |
| human t cell responses against the major cysteine proteinase (cruzipain) of trypanosoma cruzi: role of the multifunctional alpha 2-macroglobulin receptor in antigen presentation by monocytes. | chagas' disease patients (cdp) develop both humoral and cellular immune responses against the major cysteine proteinase (cruzipain) from trypanosoma cruzi. here we demonstrate that complexes formed by cruzipain and alpha 2-macroglobulin (alpha 2m) are efficiently internalized by human monocytes, and that this process results in enhanced presentation of cruzipain peptides to cd4+ t cells from cdp. purified or serum alpha 2m binds to polymorphic cruzipains, but only a fraction of the proteinases b ... | 1997 | 9199965 |
| a simple trypanosoma cruzi enzyme-linked immunoassay for control of human infection in nonendemic areas. | an enzyme linked immunosorbent assay (elisa) was developed for detecting igm and igg antibodies against trypanosoma cruzi in blood bank donors from endemic or nonendemic areas. a crude extract of trypomastigotes from cultures was used as antigen. a total of 494 serum samples from patients with acute, congenital, or chronic form of chagas' disease, and from healthy french individuals were studied. the sensitivity of the elisa was determined with 89 serum samples from chagasic patients and was eva ... | 1997 | 9215584 |
| hypoxanthine phosphoribosyltransferase from trypanosoma cruzi as a target for structure-based inhibitor design: crystallization and inhibition studies with purine analogs. | the hypoxanthine phosphoribosyltransferase (hprt) from trypanosoma cruzi is a potential target for enzyme structure-based inhibitor design, based on previous studies which indicate that these parasites lack the metabolic enzymes required for de novo synthesis of purine nucleotides. by using a bacterial complement selection system, 59 purine analogs were assayed for their interaction with the hprts from t. cruzi and homo sapiens. eight compounds were identified from the bacterial assay to have an ... | 1997 | 9257742 |
| a highly sensitive and specific chemiluminescent enzyme-linked immunosorbent assay for diagnosis of active trypanosoma cruzi infection. | chagas' disease is transmitted to man either by the bite of insects harboring trypanosoma cruzi or by the transfusion of blood from infected donors. the conventional serologic testing as presently used in blood banks in south america is unsatisfactory, because of a high number of inconclusive and false-positive results. other methods such as polymerase chain reaction and enzyme-linked immunosorbent assay (elisa) with recombinant antigens have been proposed, but inherent difficulties have so far ... | 1997 | 9280332 |
| all-transglycolytic synthesis and characterization of sialyl(alpha2-3)galactosyl(beta1-4)xylosyl-p-nitrophenyl(beta1-), an oligosaccharide derivative related to glycosaminoglycan biosynthesis. | beta-d-xylopyranosides, such as p-nitrophenyl-beta-d-xylopyranoside (xyl-np) or 4-methylumbelliferyl-beta-d-xylopyranoside (xyl-meumb), when added to the culture medium of human skin fibroblasts have previously been shown to produce some np- or meumb-oligosaccharides related to the regulation of glycosaminoglycan biosynthesis. among these oligosaccharide derivatives, we synthesized the trisaccharide derivative neuac(alpha2-3)gal(beta1-4)xyl-np(beta1- as a potential inhibitor of human skin fibrob ... | 1997 | 9288934 |
| [current prospects of specific treatment of chagas' disease]. | the evolution of the specific treatment of chagas' disease, including the numerous drugs tested, is briefly summarized. since 1969 laboratory and clinical studies have persistently demonstrated that nifurtimox (nfx) and benznidazole (bnl) are the best agents for treating trypanosoma cruzi human infection, even though they cannot be considered ideal drugs. the main indications for nfx and bnl are: acute phase of the infection, congenital form, reactivation associated with immunosuppression, recen ... | 1996 | 9302778 |
| characterization of trypanosoma cruzi strains isolated from chronic chagasic patients, triatomines and opossums naturally infected from the state of rio grande do sul, brazil. | thirty-five trypanosoma cruzi strains were isolated from chronic chagasic patients, triatomines and opossums from different municipalities of the state of rio grande do sul. parasites were characterized by means of mice infectivity, enzyme electrophoresis and randomly amplified polymorphic dna (rapd) analysis. twenty-nine strains were isolated from chagasic patients, 4 from triatomines (2 from triatoma infestans and 2 from panstrongylus megistus) and 2 from opossums didelphis albiventris. thirty ... | 1997 | 9332599 |
| specific inhibitory effect of 3-deazaneplanocin a against several leishmania mexicana and l. braziliensis strains. | the growth inhibitory effect of 3-deazaneplanocin a (c3npca) was tested against some pathogenic members of the family of american trypanosomatidae. under our culture conditions, c3npca displayed a strongly and uniformly leishmanistatic effect on all 23 american leishmania (l. mexicana and l. brasiliensis) strains in the study (mean dose producing 50% inhibition compared with control parasite growth [id50] = 96 ng/ml, 0.32 microm), but showed no inhibition against the several t. cruzi and t. rang ... | 1997 | 9347954 |
| negligible prevalence of antibodies against trypanosoma cruzi among blood donors in the southeastern united states. | trypanosoma cruzi, a hemoflagellate, causes chagas' disease and is endemic throughout latin america. increasing latin american immigration to the united states has enhanced concern about transmission of chagas' disease by infected donor blood. the insect vector and parasites also have been found in the southeastern united states. autochthonous infection of several species of wild and domesticated mammals suggests that the general human population also may be at risk. to assess the prevalence of ... | 1997 | 9353087 |
| serodiagnosis of american trypanosomosis by using nonpathogenic trypanosomatid antigen. | crithidia luciliae, a nonpathogenic trypanosomatid, could provide a good alternative source of antigen for serodiagnosis of chagas' disease. an enzyme-linked immunosorbent assay showed 100% sensitivity and 83% specificity when 91 human serum samples from chagas' disease patients and 127 human serum samples from people suffering from toxoplasmosis (21 samples), leishmaniasis (32 samples), systemic rheumatic diseases (33 samples), and heart diseases (41 samples) were tested simultaneously with try ... | 1997 | 9399545 |
| [quantitative determination of serum anti ribosomal-p protein antibody by enzyme immunoassay]. | an enzyme immunoassay for serum anti-ribosomal p protein antibodies (anti-p) is developed, using highly purified synthetic ribosomal p peptides of the carboxyl terminal 22 amino acid sequence conjugated to human serum albumin (hsa) as an antigen. anti-p levels were determined by subtracting the nonspecific binding activities to hsa. the concentration of anti-p which produced half of the maximal absorbance at 492 nm (od492) given by saturating concentrations of anti-p in the elisa plate was defin ... | 1997 | 9437900 |
| trypanosoma (schizotrypanum) cruzi: histopathology in mice infected with strains isolated from didelphis marsupialis from the valley of caracas (venezuela). | the histopathological alterations produced in nmri strain mice by isolates of trypanosoma cruzi from didelphis marsupialis captured near human dwellings in the valley of caracas, venezuela are described. the donor opossums showed pseudocysts and amastigotes and trypomastigotes only in the heart muscle, and few areas of discrete inflammations and lysis of some muscle cells. mice were parasitized in the heart, skeletal muscle, jejunum, colon, liver, lung, urinary bladder, penis, seminal vesicle, p ... | 1996 | 9460250 |
| trypanosoma cruzi transmission risk index (tctri): an entomological indicator of chagas disease vectorial transmission to humans. | the goal of this project was to obtain an index of chagas disease vectorial transmission to people living in infested houses. the proposed measure is an entomological indicator that estimates the number of risky bites that a human being receives per night. based on very simple techniques, the method combines control measures--the use of fumigant canisters--with fast and accurate methods to look at the physiological and parasitological stage of insects. the index can be used to compare the import ... | 1997 | 9492913 |
| human antibody responses to trypanosoma cruzi 70-kd heat-shock proteins. | heat-shock proteins of the 70-kd (hsp70) family are targets of humoral and cellular immune responses following bacterial or parasitic infections, including chagas' disease. in the present study, we measured antibodies in human sera reactive with hsp70s from the cytoplasm (cy-hsp70), mitochondrion (mt-hsp70), and endoplasmic reticulum (grp78) of trypanosoma cruzi. of the three hsp70s tested, only grp78 detected t. cruzi infection in more than 90% of nontreated (nt) patients, with cy-hsp70 and mt- ... | 1998 | 9502594 |
| pseudotumoral chagasic meningoencephalitis as the first manifestation of acquired immunodeficiency syndrome. | patients with aids frequently show secondary involvement of the brain by different infectious agents, and chagas' disease is now recognized as a potential opportunistic infection. to our knowledge, pseudotumoral chagasic meningoencephalitis has not been previously reported as the first manifestation of aids. | 1998 | 9508123 |