Publications

[difference in the antigenic composition of trypanosoma cruzi strains isolated from man and opossums. (preliminary note)].		1962	13939268
clinical and epidemiological study of chronic heart involvement in chagas' disease.	it has been estimated that, in vast areas of the american continent, there is a high prevalence of human infection by trypanosoma cruzi. such infection can lead to a variety of heart diseases, predominantly with involvement of the myocardium. the aim of the present work was to determine the prevalence of heart disease in two rural areas of venezuela with a high endemicity of chagas' disease and to try to determine the natural history of the disease. it is shown that a form of chronic myocardial ...	1966	4957485
epizootiology of trypanosoma cruzi in southwestern north america. ix. an investigation to determine the incidence of trypanosoma cruzi infections in triatominae and man on the yucatan peninsula of mexico.		1967	4965338
[wild reservoirs and vectors of trypanosoma cruzi. 23. colonization of rhodnius neglectus lent, 1954 in man-made dwellings (hemiptera, reduviidae)].		1968	4982470
[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
[infection by trypanosoma cruzi in man versus chagas' disease in tibu, north of santander, colombia].		1971	4253500
lymphocyte transformation in chagas disease.	the in vitro response of human peripheral lymphocytes to trypanosoma (schizotrypanum) cruzi antigens and to phytohemagglutinin was used to study the role of cellular immunity in chagas disease (american trypanosomiasis). solubilized t. cruzi antigens elicited 5 to 30% transformed cells in 5-day cultures of lymphocytes from adults chronically infected with t. cruzi. no major difference was noted between the response of 22 asymptomatic individuals and of 3 patients with chagasic cardiopathy. no co ...	1972	4629392
the immunology of experimental chagas' disease. iv. production of lesions in rabbits similar to those of chronic chagas' disease in man.	eight rabbits that received a single inoculation of trypomastigotes of a virulent strain of trypanosoma cruzi first developed a transient acute illness associated with parasitemia; later, 4 of these rabbits died with chronic myocarditis and/or with megacolon in the absence of demonstrable parasitemia or encysted parasites in tissues. two of these rabbits with chronic myocarditis died unexpectedly. three of the inoculated rabbits that survived the infection were sacrificed 18 months later and s ...	1975	808136
[comparative morphological studies on the kinetoplast of various species of trypanosomes, with special reference to trypanosoma cruzi (author's transl)].	comparative electron microscope studies on the morphology of the kinetoplast dna (k-dna) of the epimastigotes in many trypanosome species were carried out under standardized conditions. the k-dna shows a morphological variation during the cell cycle of culture forms of the trypanosome species under study. in longitudinal sections of the kinetoplast, the k-dna of t. cruzi appears as a compact trabecular structure; as a relatively disaggregated unit, with a central band or in a transitional stage ...	1975	1099748
[vaccination with live, non-virulent trypanosoma cruzi vaccine in man. a 5-year follow up study the 1st 2 cases].		1976	790483
demonstration of kinetoplast dna in trypanosomidae by using a fluorescent compound employed in human cytogenetics.		1976	794608
in search of anti-trypanosoma cruzi drugs: new leads from a mouse model.	nine of 25 carefully selected compounds (from a stock of more than 200 000 chemical species amassed principally as a result of testing against other parasitic diseases) were found to have significant suppressive activity against the parasites in the blood of a trypanosoma cruzi mouse model. eight of these compounds evaluated in this model had suppressive activity equal to or greater than the reference compound, nifurtimox. for the first time, suppressive activity against t. cruzi is reported for ...	1977	69024
feeding preferences of triatoma dimidiata maculipennis in yucatan, mexico.	to determine whether a low preference for human blood by triatoma dimidiata maculipennis stal, 1859, the only known vector of chagas' disease in yucatan, mexico, would account for the low prevalence of antibodies to trypanosoma cruzi in man in the area, the intestinal contents of 924 bugs were tested against antisera to blood antigens of chicken, opossum, dog, bat, monkey, pig, goat, rabbit, horse, human, rat, ox, cat, and armadillo. although the chicken was the primary host, man was fed upon fr ...	1977	320892
cellular immunity in chronic chagas' disease.	the cellular immune response was assessed in 20 patients with chronic chagas' disease (american trypanosomiasis). thymus-derived lymphocyte function was determined in vivo by cutaneous reactivity to several antigens including a soluble preparation derived from trypanosoma cruzi and sensitization to 2,4-dinitrochlorobenzene. the in vitro t-cell reactivity was investigated by the proliferative response to phytohemagglutinin and to t. cruzi antigen and by inhibition of leukocyte migration with the ...	1977	404317
naturally occurring trypanosomiasis (chagas' disease) in dogs.	nine fatal cases of canine american trypanosomiasis (chagas' disease) were encountered from november, 1972, through november, 1975. of the 9 cases, 7 occurred in dogs from 5 central texas counties, and all but one case was diagnosed during the months of september, october, or november. the source of infection was discovered in only one case--that being a doghouse heavily infested with triatoma lectularius occulta. each of 6 bugs collected had infective forms of the protozoan, trypanosoma cruzi. ...	1977	407202
the primary isolation by haemoculture of trypanosoma (schizotrypanum) cruzi from animals and from man.		1978	416524
protein typing by disc electrophoresis of some species of trypanosomes with special emphasis to trypanosoma cruzi.	proteins extracted from culture forms of t. cruzi, t. cruzi-like strains, t. rangeli, t. conhorrini and t. dionisii were separated by disc electrophoresis. the electrophoretic protein patterns of all strains examined were highly reproducible. the results indicate that each of these strains have their own "fingerprints" and the trypanosoma species could be identified by some typical specific protein bands. however, it was not possible to distinguish between the human strains of t. cruzi and the t ...	1978	347650
trypanosoma cruzi: in vitro interactions between cultured amastigotes and human skin-muscle cells.		1978	354958
immunology of chagas' disease. iii--absorption of human chagasic sera with epimastigotes of different strains of trypanosoma cruzi.		1978	108797
[reservoirs and wild vectors of trypanosoma cruzi. lxxiv. behavior of amastigotes and trypomastigotes of cultures of different t. cruzi strains incubated with normal human serum and inoculated into mice].		1979	121615
[solid-phase radioimmunoassay for the study of the humoral response to trypanosoma cruzi].	a solid-phase micro-radioimmunoassay (rie-s) test was adapted fore the study of the humoral immune response induced by trypanosoma cruzi infection. the solid phase, consisting of disposable polypropylene tubes, was sensitized by absorption of t. cruzi antigen. the procedure was performed by sequential adding to the solid-phase, the human serum under study and 131i anti-human immunoglobulin. then, the specific label binding was estimated. several factors which influence the test were studied. the ...	1979	122384
isolation and characterization of a new serodeme of trypanosoma rhodesiense.	the isolation and characterization of a new serodeme of trypanosoma brucei rhodesiense is described. a clone of organisms derived from a human infection produced chronic infections in mice. additional clones of differing antigenic specificities were isolated from peaks of parasitemia which occurred in these mice. the variable antigen types (vats) of these clones were determined by agglutination, immunofluorescence, and protection of actively immunized mice. thirteen distinct vats were isolated a ...	1979	92203
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
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
immune response in human chagas disease ii. lymphocyte blastogenesis in patients with chagasic cardiomyopathy.		1980	7034436
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
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
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
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
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
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
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
[phagocytosis of the epí and trypomastigote forms of trypanosoma cruzi by peripheral human leukocytes].		1982	6763127
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
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
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
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
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
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
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
lactoferrin effects on phagocytic cell function. i. increased uptake and killing of an intracellular parasite by murine macrophages and human monocytes.	mouse peritoneal macrophages (mpm) or human blood monocytes (hbm) co-cultured with intracellular (amastigote; ama) forms of trypanosoma cruzi in the presence of human lactoferrin (lf) took up greater numbers of organisms than in the absence of lf; the proportion of phagocytes taking up ama was also significantly increased. pretreatment of either mpm or ama with lf also enhanced cell-parasite association. by immunofluorescence, hbm, mpm, and ama were found to bind lf. by using 125i-labeled lf, ea ...	1985	3886800
chagas' heart disease: experimental models.	an experimental model embodies an evaluation procedure that helps the investigator to choose between possible alternatives. in this paper, consideration is given to a variety of aspects related to the host-parasite relationship in trypanosoma cruzi infection and disease. although several animal species have been used, there is still a lack of consistent experimental studies. a few examples of investigations mainly in dogs, monkeys, and rabbits are briefly described, showing the diversity of meth ...	1985	3916473
longitudinal study of immune response in human chagas' disease.	immune response, clinical status, and reactivity to heart tissue were studied longitudinally for 1 year in 42 patients with chagas' disease (south american trypanosomiasis). the patients were divided into two groups. group 1 was composed of patients with chagasic infection with no evidence of heart disease. group 2 patients had chagasic infection and cardiomyopathy. humoral immune response to trypanosoma cruzi was measured serologically, and cell-mediated immune responses to t. cruzi and rat hea ...	1985	3930564
[trials for optimization of the culture conditions of human pathogenic trypanosomas and leishmania].	due to the extended political, cultural and economic relations with tropical countries a good knowledge of tropical diseases is required. since the direct parasitological diagnosis is superior to the serological one it seems logical to improve the culture conditions for laboratory diagnosis and for immunological and chemotherapeutical tests. trypanosoma cruzi (chagas) and leishmania donovani (kala-azar) were tested in vitro. enlargement of the culture surface at the same volume of the medium at ...	1985	3937462
antibody response to experimental trypanosoma rangeli infection and its implications for immunodiagnosis of south american trypanosomiasis.	differential immunodiagnosis of t. rangeli and t. cruzi infections in man poses a particular problem, not only because these parasites share antigenic determinants, as detected by immunofluorescence, but also because they have a similar geographical distribution, the same host range and often identical insect vectors. we show here that whereas mouse anti-t. rangeli sera have significant cross reactivity with t. cruzi by immunofluorescence, they are entirely specific when tested by elisa, using a ...	1985	2868633
on the mechanism of killing of trypanosoma cruzi by human polymorphonuclear leukocytes.	the temperature-dependence of some processes involved in the killing of sensitized t. cruzi epimastigotes by human polymorphonuclear leukocytes (pmn) was determined. the rate of the reactions was related to the temperature of incubation according to the arrhenius equation and the apparent energies of activation (ea) were calculated. the ea values separated these complex reactions into two groups: one with ea of about 10 kcal/mol for the phagocytosis of the parasites and the release of lysosomal ...	1985	2981702
characterization of dolichol monophosphate- and dolichol diphosphate-linked saccharides in trypanosomatid flagellates.	dolichol-p- and dolichol-p-p-linked saccharides were isolated from several trypanosomatid flagellates incubated with [u-14c]glucose. formation of glc-p-dolichol and man-p-dolichol was observed in herpetomonas muscarum and leishmania adleri, whereas only the latter derivative was synthesized in trypanosoma dionisii and leptomonas samueli. the main and largest dolichol-p-p-linked oligosaccharide formed in trypanosoma conorhini, t. dionisii, l. samueli, herpetomonas samuelpessoai and h. muscarum ap ...	1986	3083254
a protein a-binding, polyethylene glycol precipitation-based immunoradiometric assay. application to the detection of immune complexes and c3 in human sera and of private antigens in cross-reacting parasite extracts.	an immunoradiometric assay, based on the precipitation of antigen-antibody complexes by polyethylene glycol (peg) and on the subsequent binding of peg-soluble radiolabelled staphylococcal protein a to the peg-insoluble complexes, is described. the assay can be applied to the detection of naturally occurring, circulating immune complexes, and of complexes artificially created by mixing antigen and antibody solutions, which makes it of potential use for the detection of either antigen or antibody ...	1986	3517172
novobiocin antagonism of amastigotes of trypanosoma cruzi growing in cell-free medium.	inhibitors of the enzyme bacterial topoisomerase ii (dna gyrase) were evaluated for activity against trypanosoma cruzi (brazil strain), based on the theoretical need for a topoisomerase ii in the replication of the kinetoplast dna network. novobiocin (500 micrograms/ml) antagonized amastigotes of t. cruzi growing in a cell-free medium at 37 degrees c, as manifested by inhibition of multiplication, abnormal morphology of giemsa-stained organisms, and delayed or absent growth of cells upon subcult ...	1986	3521485
the karyotype and ploidy of trypanosoma cruzi.	little is known of the number or organization of chromosomes in trypanosoma cruzi, the protozoan parasite responsible for chagas' disease in man in the new world. straightforward cytogenetic analysis is precluded because trypanosome chromosomes fail to condense during the cell cycle. we have size-fractionated the chromosome-sized dna molecules of representative t. cruzi strains by pulsed field gradient (pfg) gel electrophoresis and located several housekeeping genes by southern blotting using cd ...	1986	3525150
identification of specific and cross-reactive antigens of leishmania donovani chagasi by human infection sera.	cloned leishmania donovani chagasi (ldc) promastigotes were analyzed by sds-page separation and immunoblotting with human infection sera. the patterns of antigen reactivity were compared by using sera from individuals with ldc, leishmania mexicana amazonensis (lma), trypanosoma cruzi, mycobacterium tuberculosis, or mycobacterium leprae infections. sera from individuals with these infections recognized ldc antigens in several m.w. ranges. reactivity was due to recognition of ldc molecules and not ...	1987	3543131
specific inhibition of trypanosoma cruzi neuraminidase by the human plasma glycoprotein "cruzin".	plasma of normal human individuals was shown to contain an inhibitor of trypanosoma cruzi neuraminidase (naase; acylneuraminyl hydrolase, sialidase, ec 3.2.1.18). the inhibitor has been purified to homogeneity by peg precipitation, cm affi-gel blue sepharose chromatography, and gel filtration. the purified preparation inhibits t. cruzi naase at a concentration as low as 10(-9) m and has no effect at concentrations at least 100 times higher on any of the other naases tested, including those from ...	1987	3554230
glycoproteins of trypanosomes: their biosynthesis and biological significance.	1. trypanosomes are unicellular parasites that cause human sleeping sickness in africa and chagas' disease in south america. glycoproteins are important components of their plasma membrane. 2. the bloodstream form of the extracellular salivarian african trypanosome (e.g. trypanosoma brucei) has the ability to express on its cell surface a repertoire of variant surface glycoproteins (vsgs) and in so doing, evades the immune response of the host (antigenic variation). 3. the vsg is probably synthe ...	1987	3315421
the conduction system of the heart in mice chronically infected with trypanosoma cruzi: histopathological lesions and electrocardiographic correlations.	chronic focal and diffuse myocarditis with interstitial fibrosis developed in swiss outbred mice and in the inbred akr and a/j strains of mice which were chronically infected with several trypanosoma cruzi strains belonging to three biological types (type i, ii and iii). high incidence of electrocardiographic changes with predominance of intraventricular conduction disturbances, 1st. and 2nd. degree av block, arrhythmias, comparable with those found in human chagas' disease, were also present. m ...	1987	3507566
suppression of human lymphocyte responses by trypanosoma cruzi.	virtually nothing is known about the basis for the immunosuppression associated with human t. cruzi infection. we have used an in vitro system to explore this effect. incubation of human peripheral blood mononuclear cells (pbmc) with blood forms of t. cruzi abrogated their responses to suboptimal, optimal and supraoptimal doses of con a, pha or pwm, whether or not monocytes were depleted. killed parasites were not suppressive. maximal suppression (74%) occurred when the parasites were present du ...	1987	3102355
inhibition of mammalian host cell infection by insect-derived, metacyclic forms of trypanosoma cruzi in the presence of human or rabbit anti-t. cruzi antibodies.		1987	3106253
synthesis of dolichol derivatives in trypanosomatids. characterization of enzymatic patterns.	we have previously described that in certain parasitic protozoa, namely the trypanosomatids, the dolichol-p-p-linked oligosaccharides synthesized in vivo and transferred to protein are devoid of glucose residues and contain 6, 7, or 9 mannose units depending on the species. we have now conducted a cell-free characterization of the enzymatic patterns responsible for these phenotypes. microsomes from trypanosoma cruzi, crithidia fasciculata, leishmania enriettii, and blastocrithidia culicis were f ...	1987	3112153
characterization of trypanosoma cruzi antigens recognized by sera from patients with chronic chagas' disease.	the aim of this work was to study the trypanosoma cruzi antigens more reactive with antibodies from chagasic patients. for this purpose, the polypeptidic spectrum of cytosol was analyzed by isoelectric focusing. it showed about thirty bands distributed along a ph gradient of 3-10. in order to study the antigenicity of these polypeptides, four fractions from the focused cytosol were eluted and then analyzed by elisa with chagasic and control sera. the more acidic and homogeneous fraction (fiv, pi ...	1987	3119504
use of monoclonal antibodies for the differential detection of trypanosoma cruzi and t. rangeli in epidemiological studies and xenodiagnosis.	t. cruzi and t. rangeli have the same insect and mammalian hosts, including man, and in addition share approximately half the antigenic determinants recognised by the humoral response. thus serodiagnosis of t. cruzi infection in areas where t. rangeli is endemic may include an unknown rate of false positives due to this antigenic cross-reactivity. similarly, the results of xenodiagnostic procedures and epidemiological surveys of insect vectors are prone to distortion because of the close morphol ...	1987	2894129
circulating antibodies to mouse laminin in chagas disease, american cutaneous leishmaniasis, and normal individuals recognize terminal galactosyl(alpha 1-3)-galactose epitopes.	sera from patients with american cutaneous leishmaniasis and chagas disease and from monkeys infected with either trypanosoma cruzi or trypanosoma rhodesiense show, in rias, strong binding to mouse laminin. a distinct although weaker binding activity is also detected in normal human sera. the antibodies recognize a common carbohydrate epitope present on mouse laminin, which was assigned to a terminal galactosyl(alpha 1-3)-galactose group. distinct crossreactions were observed with some other bas ...	1987	2439642
antigenic determinants of trypanosoma cruzi defined by cloning of parasite dna.	a genomic dna library from trypanosoma cruzi, the agent of chagas' disease, was constructed in the gt11 lambda vector and was screened with serum from a chagasic patient. out of 53 positive clones, 23 plaques were purified to homogeneity and 10 different groups were defined by cross-hybridization experiments and by reaction of antibodies selected with products from each recombinant clone. native t. cruzi proteins of molecular mass ranging from 85 to larger than 205 kda that share antigenic deter ...	1987	2444885
toxic effects produced or mediated by human eosinophil granule components on trypanosoma cruzi.	the eosinophil granule major basic protein, the eosinophil cationic protein, and the eosinophil-derived neurotoxin were found to be lytic for trypanosoma cruzi trypomastigotes from blood, cell cultures, or insect vectors and for cultured amastigotes. the toxic effects of the major basic and cationic proteins were inhibited by the polyanions heparin and dextran sulfate, in keeping with the cationic nature of these proteins, or by heat denaturation, suggesting that molecular conformation was also ...	1988	2451444
in vitro cytocidal effect of novel lytic peptides on plasmodium falciparum and trypanosoma cruzi.	plasmodium falciparum and trypanosoma cruzi were killed by two novel lytic peptides (sb-37 and shiva-1) in vitro. human erythrocytes infected with p. falciparum, and vero cells infected with t. cruzi, were exposed to these peptides. the result, in both cases, was a significant decrease in the level of parasite infection. furthermore, the peptides had a marked cytocidal effect on trypomastigote stages of t. cruzi in media, whereas host eukaryotic cells were unaffected by the treatments. in view o ...	1988	3049204
effect of heterocyclic analogues of triphenylmethane dyes against trypanosoma cruzi.	several heterocyclic analogues of triphenylmethane dyes have been synthesized. their in vitro activity has been evaluated using the epimastigote forms of trypanosoma cruzi as an assay system. the malachite green and gentian violet dyes previously reported as trypanocidal agents were also tested for comparison. among the compounds tested, the 2-benzothienyl-bis-(4,4'-dimethylaminophenyl) derivative proved to be the most interesting, because of its high selectivity in killing parasites. the id50, ...	1988	3074737
specific binding of human plasma high density lipoprotein (cruzin) to trypanosoma cruzi.	binding of high density lipoprotein (hdl) to trypanosoma cruzi was examined because of its ability to specifically inhibit the parasite's neuraminidase. 125i-labeled hdl bound to live and glutaraldehyde-fixed parasites equally well either at 37 degrees c or at 4 degrees c. binding was saturable and inhibited by unlabeled hdl but not by unrelated plasma proteins. specificity of the t. cruzi-hdl interaction was confirmed using fluorescein labeled hdl which bound to t. cruzi but not to t. rangeli, ...	1988	2838753
a radiometric assay for diagnosing lytic antibodies in trypanosoma cruzi infection.	infective forms of trypanosoma cruzi were used to evaluate the complement-mediated lysis (coml) of the parasites in the presence of anti-t. cruzi sera. parasites released to the supernatant from infected vero cell monolayers were used. cultures of 1-3 x 10(6) parasites/ml were incubated for 24 h in the presence of 10 microci/ml of 3h-uridine. under these conditions 10(5) parasites used for each determination incorporated about 9600 dpm of the radioactive material. the release of tritium from lab ...	1988	3143107
antibody response and antigen recognition in human infection with trypanosoma cruzi.	sequential serum samples of an individual accidentally infected with trypanosoma cruzi were examined to study the evolution of the antibody response, particularly of those with the capacity to lyse trypanosomes, and to determine the antigens of each of the 3 stages of the life cycle of t. cruzi, recognized by antibodies formed as the infection progresses. t. cruzi specific igm and subclasses of igg antibodies were detected and reached peak levels at the same period of time. lytic antibodies were ...	1988	3143270
[transmission of trypanosoma cruzi in a case, during lactation, in a non-endemic area].		1988	3151133
developmentally regulated expression by trypanosoma cruzi of molecules that accelerate the decay of complement c3 convertases.	we recently showed that culture-derived metacyclic trypomastigotes (cmt), but not epimastigotes (epi), of the miranda 88 strain of trypanosoma cruzi evade lysis by the human alternative complement pathway because of inefficient binding of factor b to complement component c3b on the parasite surface. these results suggested that cmt and tissue-culture-derived trypomastigotes (tct), which also activate the alternative pathway poorly, might produce a molecule capable of interfering with factor b bi ...	1988	3277170
structure and expression of two trypanosoma cruzi genes encoding antigenic proteins bearing repetitive epitopes.	trypanosoma cruzi genes were cloned in lambda gt11 and screened with an anti-trypomastigote antiserum. two out of twelve clones were selected in view of their reactivity with human chagasic sera. one clone encodes a flagellar antigen (fra) of more than 300 kda, whereas the other corresponds to a roughly 225-kda cytoplasmic antigen (cra). the flagellar antigen is present in both epimastigotes and trypomastigotes, but the cytoplasmic antigen is not found in trypomastigotes. the cra clone is entire ...	1989	2475776
phosphocholine epitopes on helminth and protozoal parasites and their presence in the circulation of infected human patients.	antigens containing phosphocholine (pc) circulate in the blood during chronic filarial infection. because of the wide occurrence of such pc epitopes, we examined their specificity by evaluating 10 common parasites of humans for the presence of pc epitopes, and sera from patients infected with these parasites for circulating antigens containing pc. immunoblot analysis of extracts from various parasites using an anti-pc monoclonal antibody (ca101) demonstrated the presence of pc epitopes on the pr ...	1989	2482559
the activity of ketoconazole and other azoles against trypanosoma cruzi: biochemistry and chemotherapeutic action in vitro.	trypanosoma cruzi epimastigotes in culture medium, and amastigotes and trypomastigotes in cultured human diploid lung cells were exposed to the antimycotic agent ketoconazole and their growth and/or sterol biosynthesis observed. propagation of epimastigotes and amastigotes was impaired by concentrations of ketoconazole achievable in human serum, and amastigotes were more sensitive than were epimastigotes. epimastigotes and trypomastigotes (non-dividing stage) displayed changes in their membrane ...	1989	2494453
identification of a trypanosoma cruzi antigen that is shed during the acute phase of chagas' disease.	a trypanosoma cruzi antigen which is shed into the culture medium by the trypomastigote stage of the parasite and detected in blood of acutely infected mice was cloned and characterized. we designate this antigen shed acute phase antigen (sapa). five protein bands with apparent molecular masses ranging from 160 to 200 kda were detected by immunoblotting of plasma from infected mice and in supernatants of cultured trypomastigotes upon reaction with antibodies against sapa. a serum obtained from a ...	1989	2499788
[problems related to the diagnosis of chagas' disease].	trypanosoma cruzi may be transmitted to a susceptible human through different routes: a superficial lesion in the skin, such as a scraping of the small wound produced by the hematophagous triatomid bug vector, which becomes infected with its contaminated feces; the placenta, from the infected mother to the product of conception; a transfusion from an infected donor, or even by ingestion of diverse foods infected or contaminated with the parasite. whichever may be the transmission of the protozoo ...	1989	2517014
characterization of a protein from trypanosoma cruzi trypomastigotes that cleaves non-immune igg bound through its fab fragment.	a protein from trypanosoma cruzi bloodstream trypomastigotes that binds igg from man and several other animal species was isolated and characterized. the 52-kda protein obtained from different t. cruzi cell extracts showed saturable binding with a k of 3.72 nm. immunoblot analysis revealed that fab, but not fc, fragments of the ig were recognized. when the protein was added to an unrelated c-fixation reaction, lysis was abolished in a dose-dependent fashion. when freshly prepared t. cruzi extrac ...	1989	2645365
trypanosoma cruzi: endocytosis and degradation of specific antibodies by parasite forms.	specific human igg antibodies bound to a trypanosoma cruzi envelope were internalized by antigen receptor-mediated endocytosis. ferritin conjugated antibodies and horseradish peroxidase (hrp) conjugated igg were found inside parasite cytoplasmic vesicles. nonspecific igg that did not bind to the external membrane was not internalized by the parasite. the ratio of 3h-protein a labeled: specific igg internalization by parasites in the exponential growth phase (95% epimastigotes) was much smaller t ...	1989	2645803
trypanothione reductase from trypanosoma cruzi. catalytic properties of the enzyme and inhibition studies with trypanocidal compounds.	trypanothione reductase of trypanosoma cruzi is a key enzyme in the antioxidant metabolism of the parasite. here we report on the enzymic and pharmacological properties of trypanothione reductase using glutathionylspermidine disulfide as a substrate. 1. both ph optimum (7.5) and the ionic strength optimum (at 30 mm) are unusually narrow for this enzyme. 40 mm hepes, 1 mm edta, ph 7.5 was chosen as a standard assay buffer because in this system the kcat/km ratio had the highest values for both na ...	1989	2647489
interaction of human eosinophils or neutrophils with trypanosoma cruzi in vitro causes bystander cardiac cell damage.	we studied in vitro whether human eosinophils (eos) or neutrophils (pmn), which infiltrate the cardiac lesions of patients with chagas' disease, have the potential to contribute to pathogenesis upon interaction with trypanosoma cruzi. incubation of eos or pmn with t. cruzi amastigotes in the medium overlaying heart myoblast monolayers for 1-6 hr resulted in myoblast injury denoted by cell detachment (35-85%) accompanied by a small but reproducible degree of cell lysis (less than 15%). myoblast i ...	1989	2647628
the intracellular fate of histoplasma capsulatum in human macrophages is unaffected by recombinant human interferon-gamma.	human alveolar, peritoneal, and cultured macrophages were exposed in vitro to human recombinant interferon-gamma (rhuifn-gamma) and were tested for their ability to inhibit intracellular replication of yeast-phase histoplasma capsulatum. exposure at various concentrations, and for different time periods, failed to activate the macrophages to inhibit multiplication of intracellular yeast. macrophages were, however, activated by rhuifn-gamma as shown by their ability to inhibit intracellular repli ...	1990	2104917
characterization of major surface and excretory-secretory immunogens of trypanosoma cruzi trypomastigotes and identification of potential protective antigen.	the surface antigens of trypanosoma cruzi trypomastigotes were identified by immunoprecipitation and were compared with metabolically labelled excretory-secretory products (es) released by the parasites in vitro. a series of major immunogenic components in the es antigens were revealed (160 kda, 130 kda and 80-110 kda). the trypomastigote surface also bears the 130 kda band and the 80-110 kda complex. competition experiments demonstrated the common antigenic structure of the es and the surface a ...	1990	2107503
elevated cerebroside antibody levels in human visceral and cutaneous leishmaniasis, trypanosoma rangeli infection, and chronic chagas' disease.	a natural cerebroside (antic) igm antibody was found at relatively high levels in the serum of every healthy individual studied. the reactivity of the antibody was assessed by using highly purified bovine brain galactocerebroside (galc) or human glucocerebroside (gluc) as antigen. the importance of fatty acid moiety of galc in antigen-antibody reaction was demonstrated by low immunoreactivity using 1-beta-d-galactosyl sphingosine (gs) as antigen and by the absence of absorption to gs-bearing lip ...	1990	2116736
trypanosoma cruzi: a possible control of transfusion-induced chagas' disease by phenolic antioxidants.	the following phenolic antioxidant food additives were evaluated against trypanosoma cruzi epimastigotes: bht, bha, gallic acid and its methyl, propyl, octyl, and lauryl esters, 2,4-di-tert-butyl-6-(4-methoxybenzyl)-phenol, 4,4'-isopropilidenediphenol, and protocatechuic acid and its ethyl ester. the inhibition of the respiration; the changes in motility, shape, and lysis of the parasites; and the human blood hemolysis caused by these chemicals were studied. human blood samples experimentally co ...	1990	2121515
trypanosoma cruzi: experimental chagas' disease in rhesus monkeys. ii. ultrastructural and cytochemical studies of peroxidase and acid phosphatase activities.	ultrastructural and cytochemical studies of peroxidase and acid phosphatase were performed in skin, lymph node and heart muscle tissue of rhesus monkeys with experimental chagas' disease. at the site of inoculation there was a proliferative reaction with the presence of immature macrophages revealed by peroxidase technique. at the lymph node a diffuse inflammatory exudate with mononuclear cells, fibroblasts and immature activated macrophages reproduces the human pattern of acute chagas' disease ...	1990	2128361
[effect of cyclosporin and prednisone on the acute phase of experimental infection of mice by trypanosoma cruzi].	the relations between immunosuppression and human or experimental infection by trypanosoma cruzi have recently been the subject of great interest, specially because of the wider use of drugs acting on immunity and of organ transplantation programs, now in frank expansion. the use of cyclosporin turned necessary to know adequately its interactions with t. cruzi parasitosis, and this has been the objective of the present study, regarding the acute phase in mice, in comparison to the use of prednis ...	1990	2135359
trypanosoma cruzi: modification of alkaline phosphatase activity induced by trypomastigotes in cultured human placental villi.	human term placental villi cultured "in vitro" were maintained with bloodstream forms of trypanosoma cruzi during various periods of time. two different concentrations of the parasite were employed. controls contained no t. cruzi. the alkaline phosphatase activity was determined in placental villi by electron microscopy and its specific activity in the culture medium by biochemical methods. results showed that the hemoflagellate produces a significant decrease in enzyme activity as shown by both ...	1990	2135485
trypanosoma cruzi inhibits the expression of cd3, cd4, cd8, and il-2r by mitogen-activated helper and cytotoxic human lymphocytes.	we studied the effects of trypanosoma cruzi secretion products on the capacity of helper (th) and cytotoxic (tc) cells to express il-2r, cd3, cd4, and cd8 in response to pha or anti-cd3 stimulation. to this end, we used a culture system in which blood forms of the parasite were cocultured with human pbmc. two-color flow cytometry studies revealed that, under these conditions, there was a significant decrease in the percentage of both th and tc cells expressing il-2r (inhibition range = 30 to 65% ...	1990	2139458
a galactosyl(alpha 1-3)mannose epitope on phospholipids of leishmania mexicana and l. braziliensis is recognized by trypanosomatid-infected human sera.	an immunoglobulin m antibody reactive with galactosyl(alpha 1-3)mannose [gal(alpha 1-3)man] residues present on phospholipids extracted from leishmania mexicana and l. braziliensis was found to be present in high titer in the serum of every normal individual studied. periodate oxidation, acid hydrolysis, or acetylation suppressed immunoreactivity, suggesting that an oligosaccharide chain was responsible for antibody binding. interaction occurs only with alpha-gal terminal residues, since treatme ...	1990	1696285
trypanosoma cruzi: cloning and expression of an antigen recognized by acute and chronic human chagasic sera.	here we describe the characterization of a trypanosoma cruzi dna sequence (clone a13) that codes for a polypeptide recognized by igm and igg antibodies from sera of acute and congenital chagasic patients. antibodies to a13 antigen are also detected in the sera of chronic patients with different clinical forms of chagas' disease, but not in sera of patients with leishmaniasis or other parasitic diseases. the antigenic determinants encoded by clone a13 are found in amastigotes and trypomastigotes ...	1990	1698656
extracellular matrix derived from trypanosoma cruzi infected endothelial cells directs phenotypic expression.	infection of confluent human umbilical vein endothelial cells by the parasite trypanosoma cruzi results in the appearance of an altered heparan sulfate proteoglycan (hspg) isolated from the extracellular matrix of infected endothelial cells (ecmi). hspg from ecmi differed from hspg obtained from the extracellular matrix of uninfected endothelial cells (ecmu) by virtue of an 8-10-fold increase in sulfation and a different elution pattern using deae sepharose chromatography. analysis of the hspg t ...	1990	1700983
complement-mediated lysis of trypanosoma cruzi trypomastigotes by human anti-alpha-galactosyl antibodies.	antibodies that lyse trypomastigotes in a complement-mediated reaction are believed to be the main participants in the protection against virulent trypanosoma cruzi. antibodies with a specificity for alpha-galactosyl-containing determinants--generally called antigal--were studied to determine their role in the lysis of trypomastigote forms. the titers of antigal markedly increase in chagas's disease. in the present study we demonstrate binding of this antibody to t. cruzi and the complement-medi ...	1991	1706399
trypanosoma cruzi induces suppression of dna synthesis and inhibits expression of interleukin-2 receptors by stimulated human b lymphocytes.	trypanosoma cruzi, the causative agent of chagas' disease, suppresses immune responses during the acute phase and has been shown to induce multiple cellular alterations in activated human t lymphocytes. however, no information is available regarding the effects of this parasite on human b cells. using an in vitro culture system, in which purified t. cruzi are co-cultured with either peripheral blood mononuclear cells (pbmc) or b-cell-enriched preparations (bce), we studied whether the organism c ...	1991	1748480
acute fatal trypanosoma cruzi meningoencephalitis in a human immunodeficiency virus-positive hemophiliac patient.	a 37-year-old hemophiliac patient with known, asymptomatic human immunodeficiency virus infection and chronic chagas' disease was admitted to the hospital complaining of fever and headache. a computed tomographic scan revealed multiple ring-enhancing lesions in both cerebral hemispheres. no antibodies to trypanosoma cruzi were found in the cerebrospinal fluid. treatment for toxoplasmosis of the central nervous system, which was considered the most likely diagnosis, was instituted, but the patien ...	1991	1763799