Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| [chagas disease in the elderly]. | 1985 | 2940994 | |
| effects of ethidium bromide on the mitochondrial adenosine triphosphatase from trypanosoma cruzi. | culturing of trypanosoma cruzi in the presence of ethidium bromide (eb; 1.0-2.5 microm), for 5 days, affected the biogenesis of the fo/f1-atpase complex, presumably by eb interference with the expression of the putative fo-sector subunits encoded by maxicircle dna. in vitro, eb inhibited atp hydrolysis by the fo/f1-atpase complex and also by soluble f1, the former preparation being the most strongly affected (eb i50, 250 microm). analysis of eb effect at increasing mgatp concentrations, as well ... | 1986 | 2941019 |
| mechanism of resistance to lysis by the alternative complement pathway in trypanosoma cruzi trypomastigotes: effect of specific monoclonal antibody. | trypanosoma cruzi g strain epimastigotes were lysed by normal human serum (nhs) through activation of the alternative complement pathway (acp), whereas metacyclic trypomastigotes were resistant to lysis. epimastigotes and metacyclics with equivalent amounts of c3b deposited on their surface bound factor b with similar affinities. in contrast, factor h bound with higher affinity to metacyclics than to epimastigotes. both t. cruzi forms with bound c3b were extensively (60 to 80%) lysed after forma ... | 1986 | 2943798 |
| evasion of alternative complement pathway by trypanosoma cruzi results from inefficient binding of factor b. | during its differentiation in the insect vector to a stage infective for the mammalian host, trypanosoma cruzi becomes resistant to lysis by the alternative pathway of complement. to elucidate the mechanism of complement evasion, we studied control of complement activation on the surface of the noninfective epimastigote and the infective culture-derived metacyclic trypomastigote stages (cmt) of t. cruzi. it was found that the predominant form of complement component c3 on epimastigotes is c3b, w ... | 1986 | 2944112 |
| selective suppression of tumour-immune cytolytic t lymphocytes in mice with chronic trypanosoma cruzi infections. | trypanosoma cruzi is the causative agent of chagas' disease in man, often leading to suppression of t lymphocyte functions; the present study thus considered the effects of infection by t. cruzi on t-dependent immune responses in a murine model, namely, the immune resistance to a syngeneic tumour and a delayed-type hypersensitivity reaction to sheep red blood cells (srbc). in balb.b mice infected with t. cruzi, the graft of syngeneic gross murine leukaemia virus-induced tumour cells leads to an ... | 1986 | 2944471 |
| the phosphofructokinase of trypanosoma (schizotrypanum) cruzi: purification and kinetic mechanism. | the phosphofructokinase (atp:d-fructose-6-phosphate 1-phosphotransferase, e.c.2.7.1.11) of trypanosoma (schizotrypanum) cruzi epimastigotes has been purified 180-fold, to apparent electrophoretic homogeneity, by differential centrifugation, gel filtration chromatography and anionic exchange chromatography. the minimum catalytic unit of the purified enzyme is a polypeptide of 17,000 +/- 1300 molecular weight, as shown by gel filtration chromatography and sds-gel electrophoresis. hanes-woolf plots ... | 1986 | 2946951 |
| isoenzymes of trypanosoma rangeli stocks and their relation to other trypanosomes transmitted by triatomine bugs. | culture forms of three trypanosome species, trypanosoma rangeli, t conorhini and t. cruzi, have been compared isoenzymatically by isoelectrofocusing. of 9 enzymes examined, three: nonspecific esterase (nse), phosphoglucomutase (pgm) and glucosephosphate isomerase (gpi), showed species specific enzyme profiles. little isoenzymatic variation was found amongst the 14 t. rangeli stocks examined. two of them were identified as t. cruzi of group i demonstrating the necessity of a clear identification ... | 1986 | 2947314 |
| interaction of trypanosoma cruzi adenylate cyclase with liver regulatory factors. | trypanosoma cruzi adenylate cyclase catalytic subunits may interact with regulatory factors from rat liver membranes, reconstituting heterologous systems which are catalytically active in assay mixtures containing mgatp. the systems show stimulatory responses to glucagon and guanosine 5'-[beta gamma-imido]triphosphate (p[nh]ppg) or fluoride. reconstitution was obtained by three different methods: fusion of rat liver membranes (pretreated with n-ethylmaleimide) to t. cruzi membranes; interaction ... | 1986 | 2947568 |
| use of parasite antigens and interleukin-2 to enhance suppressed immune responses during trypanosoma cruzi infection in mice. | mice infected with trypanosoma cruzi exhibit an early and profound suppression of parasite-specific and nonspecific immune responses. earlier studies have shown that this suppression is due, at least in part, to suppressor macrophages, deficiency in production of interleukin-2 (il-2), and reduced t helper (th)-cell activity. in the present study, the effect of exogenously supplied il-2 on enhancement of parasite-specific th-cell activity, anti-parasite immunoglobulin g (igg) and igm antibody lev ... | 1987 | 2948917 |
| isolation and functional characterization of murine t cell lines and clones specific for the protozoan parasite trypanosoma cruzi. | murine t cell lines responsive to the protozoan parasite trypanosoma cruzi were generated in vitro by stimulating hyperimmune c57bl/6 lymphoid cells with trypomastigote stage antigen. a spleen-derived line designated st1 and eight clones derived from st1 were characterized. all lines bear the surface phenotype thy-1.2+, ly-1.2+, 2.2- and respond to t. cruzi antigen only in the presence of antigen-presenting cells matched at the i-a subregion of the h2 locus. clonal specificity analyses indicated ... | 1987 | 2949009 |
| [chagasic cardiomyopathy in mexico]. | chronic chagas disease, has been reported in mexico, but changes in left ventricular function are not well known. we describe 25 patients with chronic trypanosomiasis with congestive cardiomyopathy. all of them lived in zones where the parasitosis is endemic and showed ekg abnormalities compatible with cardiomyopathy: a-v block in 8, rbbb in 9, lbbb in 7, rbbb + lahb in 4, arrhythmias and st-s abnormalities in 9 patients. all patients have at least one positive serological test for t cruzi: indi ... | 2016 | 2952077 |
| suppression of polyclonal antibody production in trypanosoma cruzi-infected mice by treatment with anti-l3t4 antibodies. | acute trypanosoma cruzi infection of mice results in a very marked polyclonal activation of b and t lymphocytes, accompanied by high numbers of ig-secreting pfc and lectin-dependent effector ctl. treatment of mice with monoclonal anti-l3t4 antibodies from the time of infection (days 0, 4, and 8) completely suppresses the polyclonal pfc response and ctl generation. treatment of nude mice with antibody does not alter the lipopolysaccharide-induced polyclonal pfc response, and it only modulates the ... | 1987 | 2955044 |
| long-term control of chagas disease in venezuela: effects on serologic findings, electrocardiographic abnormalities, and clinical outcome. | to evaluate the long-term effects (20 years) of a chagas control program (ccp) in venezuela, a prospective serologic evaluation was carried out from 1981 to 1984 on 5771 inhabitants (8%) of roscio county. this region was selected as a representative area where the national ccp was implemented effectively. comparison with a serologic survey performed in the same region before the ccp disclosed a reduction in seropositive subjects from 47.8% to 17.1% (p less than .001), most marked amongst childre ... | 1987 | 2957109 |
| characterization by electrophoretic zymograms of 19 trypanosoma cruzi clones derived from two chronic chagasic patients. | 1. electrophoretic patterns of aspartate aminotransferase, glucose-6-phosphate dehydrogenase, phosphoglucomutase, glucose-phosphate isomerase, malic enzyme and alcohol dehydrogenase have been analyzed in extracts from trypanosoma cruzi, tulahuén strain, 19 clones derived from isolates obtained from two chronic chagasic patients from argentina and from brazilian stocks silvio x10/1 (zymodeme 1), esmeraldo/1 (zymodeme 2), and can-iii/1 (zymodeme 3). 2. the clones isolated from one of the patients ... | 1987 | 2957146 |
| suppressive substance produced by t cells from mice chronically infected with trypanosoma cruzi. i. preferential inhibition of the induction of delayed-type hypersensitivity. | culture supernatants of spleen cells from susceptible cba mice chronically infected with trypanosoma cruzi were able to inhibit the induction of delayed-type hypersensitivity (dth) to a wide range of antigens as measured by 24-hr footpad swelling, bone marrow homing, and radioactivity accumulation assays. the suppressive activity, which was also present in the serum of these chronically infected mice, appears to be specific for the induction of dth and had no effect on the 3-hr immediate-type hy ... | 1987 | 2958550 |
| [infection of inbred mice with clones of trypanosoma cruzi]. | 1987 | 2959294 | |
| trypanosoma cruzi: differentiation to metacyclic trypomastigotes in the presence of adp-ribosyltransferase inhibitors. | the participation of adp-ribosyltransferase in trypanosoma cruzi differentiation to the metacyclic stage was evaluated by analyzing morphogenesis blockage by specific enzyme inhibitors: benzamide, 3-aminobenzamide, theophylline, and nicotinamide. in vitro assays showed a statistically significant reduction in the number of metacyclic forms only when any one of the four inhibitors was added during the period of interaction between epimastigote and triatoma infestans intestinal homogenate or when ... | 1987 | 2960557 |
| initial induction of immunity, followed by suppression of responses to parasite antigens during trypanosoma cruzi infection of mice. | infection of a relatively resistant strain of mice (c57bl/6j) with the protozoan parasite trypanosoma cruzi results in both the induction of parasite-specific t-helper cells and nonspecific suppressor cells. a time course study of the activation of help and suppression revealed that parasite-specific t-helper cell activity increases very early in infection (less than 12 days) at a time when suppression of non-parasite-specific responses and suppressor cell activity is increasing. between 12 and ... | 1987 | 2960943 |
| trypanosoma cruzi-induced suppression of il-2 production. i. evidence for the presence of il-2-producing cells. | mice infected with the protozoan parasite trypanosoma cruzi, the causative agent of human chagas' disease, are profoundly immunodepressed in their response to various ag and mitogens. a key factor in this immunosuppression is the essential inability to produce the t cell growth factor il-2. in this study we demonstrate that this failure to produce il-2 in response to mitogen stimulation is not the result of the absence of production of soluble or membrane-bound il-1 by macrophages. limiting dilu ... | 1988 | 2965729 |
| trypanosoma cruzi-induced suppression of il-2 production. ii. evidence for a role for suppressor cells. | suppression of il-2 production during experimental chagas' disease accounts at least in part for the overall depressed state of the immune system in infected mice. the failure to produce il-2 in response to mitogen stimulation is not the result of the lack of cells capable of producing il-2, but appears to be due to regulation of il-2 production by suppressor cells. this conclusion is supported by cell-mixing experiments where the ability of cells from infected mice to suppress normal spleen cel ... | 1988 | 2965730 |
| inactivation of the mitochondrial adenosine triphosphatase from trypanosoma cruzi by oxygen radicals: role of thiol groups. | inactivation of trypanosoma cruzi mitochondrial atpase by oxygen radicals, generated by redox cycling of the ascorbate-cu system (cataldi de flombaum, m.a. and stoppani, a.o.m. (1986) biochem. int. 12, 785-793), involves oxidation of the enzyme thiols, as indicated by the competitive kinetics obtained with p-chloromercuribenzoate, a selective sh-reagent. dithiothreitol prevented the ascorbate-cu effect but did not reactivate the enzyme. non-competitive kinetics were obtained with ascorbate-cu an ... | 1987 | 2968797 |
| cellular immunity to trypanosoma cruzi is mediated by helper t cells (cd4+). | the infection of mice with trypanosoma cruzi has been used as an experimental model for human chagas disease, because the murine and human infections have similar acute and chronic phases generating similar immunopathological phenomena. histopathological studies of murine tissues showed that the inflammatory lesions were small during the acute phase and composed mainly of mononuclear cells. during the chronic phase, cellular infiltrates were clustered in large granulomata consisting of mononucle ... | 1988 | 2972093 |
| gp 58/68, a parasite component that contributes to the escape of the trypomastigote form of t. cruzi from damage by the human alternative complement pathway. | a glycoprotein of apparent molecular weight 58,000 (unreduced)/68,000 (in its reduced form) (gp 58/68), which is one of the fibronectin/collagen receptors of trypanosoma cruzi, was purified to homogeneity from the trypomastigote forms of the tehuantepec and y strains of the parasite. purified gp 58/68 inhibited formation of cell-bound and fluid-phase alternative pathway c3 convertase in a dose-dependent fashion, as assessed using purified human complement components. gp 58/68 differed from the h ... | 1988 | 2973433 |
| stage-specific surface antigens during the morphogenesis of trypanosoma cruzi: developmentally regulated expression of a glycosyl-phosphatidylinositol anchored glycoprotein of amastigotes. | 1988 | 2978169 | |
| pathological effects of blastocrithidia triatomae (trypanosomatidae) on the reduviid bugs triatoma sordida, t. pallidipennis and dipetalogaster maxima after coprophagic infection. | developmental time and mortality in nymphs of the reduviid bugs triatoma sordida (stål), triatoma pallidipennis (stål) and dipetalogaster maxima (uhler) were studied in uninfected groups and in those infected with blastocrithidia triatomae cerisola et al. (trypanosomatidae). in t.sordida and t.pallidipennis, major vectors of chagas' disease in brazil and mexico respectively, infection with b.triatomae was associated with slight developmental retardations in the final instars, and increased morta ... | 1988 | 2980188 |
| 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 |
| a unique type of cyclic amp-binding protein of trypanosoma cruzi. | on centrifugation on sucrose density gradients, the cyclic amp-receptor protein of trypanosoma cruzi was clearly resolved from the type ii regulatory subunit of protein kinase from bovine heart (s20,w = 8.25 and 4.1, respectively). the binding of cyclic [3h]amp to these two proteins was affected to different extents by several cyclic amp analogues. such differences between the cyclic amp-receptor protein of t. cruzi and cyclic amp-binding proteins of other eukaryotes might be exploitable by chem ... | 1985 | 2984562 |
| chemical modification of the active site of the nadp-linked glutamate dehydrogenase from trypanosoma cruzi. | the nadp-linked glutamate dehydrogenase (nadp-gludh) purified from epimastigotes of the tulahuén strain, tul 2 stock, of trypanosoma cruzi, was inhibited by cibacron blue fg3a, and inactivated by preincubation with phenylglyoxal or woodward's reagent k. the inhibition by cibracron blue fg3a, competitive towards nadph with an apparent ki of 20 microm, suggests that the enzyme presents the "dinucleotide fold" characteristic of most dehydrogenases and kinases. the inactivation of the nadp-gludh by ... | 1985 | 2988857 |
| a cytosolic flavin-containing enzyme catalyzing reduction of cytochrome c in trypanosoma cruzi: kinetic studies with cytochrome c as substrate. | the kinetic mechanism of cytochrome c reduction by a trypanosoma cruzi cytosolic flavoenzyme was investigated by initial velocity determinations, by product inhibition patterns, and by the characteristics of inhibition by analogs. the data suggest a two-site ping-pong mechanism in which nadph reduces the flavin, which is then reoxidized in two one-electron steps by reaction with two molecules of cytochrome c. the two-site nature of the mechanism is probably related to the dimeric nature of the e ... | 1985 | 2992393 |
| biochemical peculiarities of trypanosomes, african and south american. | 1985 | 2992672 | |
| effects of antiserum to trypanosoma cruzi on the uptake and rate of killing of vector-borne, metacyclic forms of the parasite by macrophages. | 1985 | 2993180 | |
| polymorphisms within minicircle sequence classes in the kinetoplast dna of trypanosoma cruzi clones. | four minicircle classes were analyzed using cloned minicircles as probes and single-cell cloned trypanosoma cruzi parasites. the hybridization conditions used allowed identification of minicircle classes within kinetoplast dna that were non-homologous to each other. two of these minicircle classes, detected with probes ptckawp-2 and -3, were present together in several of the ca 1 and miranda clones, in spite of the fact that either ptckawp-2 or both minicircle classes were undetectable in other ... | 1985 | 2993881 |
| calmodulin and ca2+-dependent cyclic amp phosphodiesterase activity in trypanosoma cruzi. | calmodulin has been purified from trypanosoma cruzi epimastigote forms by ion-exchange chromatography, gel filtration and affinity chromatography on 2-chloro-10-(3-aminopropyl)phenotiazine-sepharose. upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the factor showed a polypeptide band with an apparent molecular weight of 16 000. in addition, cyclic amp phosphodiesterase activity from t. cruzi epimastigote forms was purified by ion-exchange chromatography and affinity chromatograph ... | 1985 | 2999589 |
| cytofluorometry as a method for the differentiation of trypanosomes. | the dna binding guanine specific antibiotic, chromomycin a3, has been evaluated for fluorescence intensity measurements of t. cruzi, t. brucei brucei and t. musculi. optimal fixation and staining conditions have been determined. the fluorometry was performed with a microscope photometer equipped with electronic systems for short time excitation of 7 milliseconds and operation control. the trypomastigote bloodstream forms of these species have a different chromomycin specific dna content. the tot ... | 1985 | 3001914 |
| [effect of proteolytic enzymes on the penetration of trypanosoma cruzi in peritoneal macrophages of mice]. | the present study deals on the modifications produced by three proteolytic enzymes in the interiorization of cultured metacyclic forms of trypanosoma cruzi in peritoneal macrophages of non-stimulated mice. the proteolytic enzymes used were trypsin, papain and collagenase. pretreatment of metacyclic forms or macrophages with the enzymes resulted in lower penetration ratios with respect to controls. on the other hand, percentages of parasitization were maintained throughout the periods of time ass ... | 1985 | 3002222 |
| in vitro and in vivo effects of itraconazole against trypanosoma cruzi. | the synthetic imidazole, itraconazole, was examined for in vitro and in vivo activity against trypanosoma cruzi. mice treated with concentrations as low as 15 mg itraconazole/kg/day were completely protected against death due to infection with any of three different and highly virulent strains of t. cruzi. treatment of infected mice with 120 mg itraconazole/kg/day for seven to nine weeks apparently resulted in the parasitologic cure as determined by negative hemocultures and subinoculations, neg ... | 1986 | 3006529 |
| the fate of plasma membrane macrophage enzyme markers during endocytosis of trypanosoma cruzi. | the enzyme activity of na+-k+-atpase, mg++-atpase, 5'-nucleotidase and adenylate cyclase was cytochemically detected, at the ultrastructural level, in normal mouse peritoneal macrophages trypanosoma cruzi. reaction product, indicative of the enzyme activity, was seen in association with the plasma membrane of the macrophage, showing an homogeneous distribution. no reaction product indicative of na+-k+-atpase, mg++-atpase or adenylate cyclase activity was seen within the cell. reaction product, i ... | 1986 | 3007776 |
| primaquine can mediate hydroxyl radical generation by trypanosoma cruzi extracts. | primaquine increases the nad(p)h dependent oxygen consumption and hydroxyl radical generation by extracts of trypanosoma cruzi, the causative agent of chagas' disease. spin-trapping studies show that hydroxyl radical yield is completely inhibited by catalase and slightly increased by sod, indicating that radical generation is dependent on the pair primaquine-nad(p)h and their interaction product, h2o2. primaquine effects upon trypanosoma cruzi extracts are compared with those obtained with nifur ... | 1986 | 3008737 |
| [a dna topoisomerase from trypanosomes able to catenate, decatenate and unknot dna without atp]. | a novel dna-topoisomerase from trypanosoma cruzi was partially purified. the enzyme, without atp addition, catalyzes decatenation of kinetoplast dna, catenation of circular supercoiled dnas and unknotting of p4 phage dna. the presence of mg++ is required as well as a suitable concentration of kcl. in stoichiometric conditions the trypanosome enzyme induces double-strand dna cleavage. the reaction is highly stimulated by some chemicals. such characteristics allow to include this enzyme into the t ... | 1986 | 3011222 |
| the regulation of phosphofructokinase in epimastigote trypanosoma cruzi. | glycosomal (microbody)-enriched fractions prepared from epimastigote trypanosoma cruzi were used as a partially purified source of phosphofructokinase. d-fructose 6-phosphate showed sigmoidal kinetics at ph 7.0, but hyperbolic kinetics at ph 8.0. various adenosine nucleotides were positive effectors; 5'-amp was the most powerful. atp showed hyperbolic kinetics under all conditions tested. several described inhibitors and activators of mammalian phosphofructokinase were without significant effect ... | 1986 | 3011512 |
| antibodies to acquired immune deficiency syndrome (aids)-associated virus (htlv-iii/lav) in venezuelan populations. | serum samples from 850 individuals from venezuela were tested for the presence of antibodies to htlv-iii/lav virus, the probable etiological agent of acquired immune deficiency syndrome (aids). at the time of the study, none of the individuals tested had symptoms indicative of aids or related disorders. viral antibodies were assayed by indirect immunofluorescence (if) assay, using a chronically infected, htlv-iii/lav producer cell line cem/lav-nit established in our laboratory. twenty individual ... | 1986 | 3013223 |
| photosensitization by the trypanocidal agent crystal violet. type i versus type ii reactions. | the photoreduction of crystal violet to a carbon-centered radical was detected directly by electron spin resonance (esr) spectroscopy under anaerobic conditions. the linewidth (0.9 g) of this radical was less broad than the linewidth (11.0 g) of the free radical obtained in trypanosoma cruzi incubations. no crystal violet radical could be detected under aerobic conditions. however, crystal violet was found to convert oxygen to superoxide anion and hydrogen peroxide in the presence of light. this ... | 1986 | 3013436 |
| the in vitro involvement of topoisomerase ii in the activity of aza-ellipticine analogues is not correlated with drug activity on isolated nuclei. | aza-ellipticines are dna intercalative ellipticine analogues with antitumor activity that induce protein-linked dna breaks in nih 3t3 cells in culture. the effects of two aza-ellipticine congeners (bd-40 and br-76) on the activity of purified calf thymus type ii topoisomerase were studied using puc13 dna as substrate. dna cleavage was stimulated by both molecules at those doses required for inducing lethal effects in cells (de5o). this effect was reversed by high salt treatment, indicating that ... | 1986 | 3015146 |
| inactivation of mitochondrial adenosine triphosphatase from trypanosoma cruzi by oxygen radicals. | incubation of trypanosoma cruzi mitochondrial atpase (fo-f1) with the xanthine oxidase system (xo), fenton's reagent (fe2+ + h2o2) and the ascorbate-cu system, caused gradual loss of enzyme activity, which increased as a function of incubation time and rate of oxygen radical generation. the essential role of oh. radicals for atpase inactivation was supported by a) the enzyme protection afforded by superoxide dismutase, catalase and mannitol, when using the xo system; b) the similar effect of man ... | 1986 | 3017349 |
| free radical metabolism of antiparasitic agents. | in recent years it has been apparent that many of the known antiparasitic drugs produce free radicals. intracellular reduction followed by autooxidation yielding o.-2 and h2o2 has been suggested as the mode of action of nifurtimox on trypanosoma cruzi and as the basis of its toxicity in mammals. on the other hand, free radical intermediates that do not generate oxygen-reduction products under physiological conditions have been found in the metabolic pathways of other antiparasitic nitro compound ... | 1986 | 3017765 |
| atp-independent type ii topoisomerase from trypanosomes. | we have characterized in trypanosoma cruzi a dna topoisomerase capable of decatenating complex trypanosomal kinetoplast dna networks in the absence of atp. the enzymatic activity requires mg2+ and k+. using a defined dna topoisomer we showed that the linking number changes by steps of 2, which characterizes the enzyme as a type ii topoisomerase. the enzyme can catenate supercoiled dna molecules, unknot dna, and cleave double-stranded dna. the enzyme has no atpase activity. the native enzyme has ... | 1986 | 3020537 |
| isolation of trypanosoma cruzi dna fragments which function as ars elements in saccharomyces cerevisiae. | genomic banks from trypanosoma cruzi total cell dna and kinetoplast dna were constructed in a bacterial plasmid carrying the yeast ura3 gene marker. this vector is by itself unable to be maintained in saccharomyces cerevisiae since it can neither replicate as an extrachromosomal element, nor readily integrate into the chromosome of ura3-52 yeast hosts. using this system, we isolated sequences from nuclear and kinetoplast dna of t. cruzi which enabled the vector to replicate autonomously in s. ce ... | 1986 | 3021587 |
| sequence diversity in the kinetoplast dna minicircles of trypanosoma cruzi. | minicircles are the most abundant component of the mitochondrially located kinetoplast dna in the members of the order kinetoplastida. minicircle sequences differ among most trypanosomatid species. to learn about the molecular mechanisms that give rise to this diversity, we sequenced a complete minicircle (ptckawp-2) and two homologous but polymorphic minicircle fragments isolated from different trypanosoma cruzi clones. comparison of these sequences revealed 23 point mutations, 19 of which were ... | 1986 | 3022143 |
| trypanosoma cruzi: differentiation after interaction of epimastigotes and triatoma infestans intestinal homogenate. | incubation of trypanosoma cruzi epimastigotes with triatoma infestans intestinal homogenate leads to differentiation to the metacyclic trypomastigote. features of this interaction are presented. the morphogenetic mechanism was triggered almost at once; for the minimum interaction period assayed (15 min), the degree of differentiation achieved in grace medium by day 6 was 70.0 +/- 9.0%. longer interaction periods failed to improve differentiation. the morphogenesis became irreversible at 4 hr aft ... | 1986 | 3023131 |
| nucleotide sequence of a trypanosoma cruzi minicircle. | 1986 | 3024132 | |
| trypanosoma cruzi: structure and transcription of kinetoplast dna maxicircles of cloned stocks. | restriction endonuclease mapping of the trypanosoma cruzi kinetoplast dna maxicircle was performed in nine cloned stocks using maxicircle probes from t. brucei. analysis of the maxicircle 13-15-kbp encoding region allowed cloned stocks to be divided into three groups: a, b, and c. parasites from groups a and b had 3% sequence divergence while parasites from group c showed 16-17% sequence divergence with regard to parasites from groups a and b. cross-hybridization experiments demonstrated that th ... | 1986 | 3025435 |
| evolution of the genus leishmania as revealed by comparisons of nuclear dna restriction fragment patterns. | restriction endonuclease dna fragment patterns have been used to examine the relationships among 28 isolates of leishmania as well as crithidia, endotrypanum, and trypanosoma cruzi. fragments of nuclear dna were generated with six restriction enzymes, and blots were hybridized with probes from three loci. among the major lineages the fragment patterns are essentially completely different, while within the major lineages various degrees of divergence are found. molecular evolutionary trees were c ... | 1987 | 3025876 |
| chemotherapy for chagas' disease: a perspective of current therapy and considerations for future research. | our current knowledge of the biology of trypanosoma cruzi and its relation to the development of chemotherapy for chagas' disease are reviewed. this includes recent developments in the understanding of kinetoplast dna and glycosomes; the action of oxygen radicals; intermediary metabolism of purines, pyrimidines, and folic acid; and the formation of microtubules. at this time, these organelles and metabolic pathways appear to be the most promising for potential exploitation for chemotherapeutic p ... | 1986 | 3025994 |
| trypanosoma cruzi: subcellular distribution of glycolytic and some related enzymes of epimastigotes. | the first six glycolytic enzymes in epimastigote trypanosoma cruzi were shown to behave similarly during differential centrifugation, when maximum relative specific activity was found in the small granule fraction, and by isopycnic centrifugation, when the bulk of each activity coequilibrated on sucrose gradients with a modal density of 1.23 g/ml. all six showed substantial detergent latency in whole cell homogenates. electron microscopic examination of fractions from a sucrose gradient with mod ... | 1987 | 3026835 |
| possible role of camp in the differentiation of trypanosoma cruzi. | to assess the possible action of camp on the cell differentiation of trypanosoma cruzi, we determined both camp levels and camp-binding activities of epimastigotes and trypomastigotes of this parasite. trypomastigotes showed a 4-fold higher camp content and a 2.5-fold increase in the specific activity of a camp-binding protein with identical properties to that of epimastigotes. the high levels of camp present in trypomastigotes strongly suggest a role of this cyclic nucleotide on the differentia ... | 1987 | 3027556 |
| subcellular fractionation of trypanosoma cruzi; isolation and characterization of plasma membranes from epimastigotes. | a procedure is described for the isolation of subcellular fractions from epimastigotes of trypanosoma cruzi. the method could separate most of the nuclei, mitochondria and microsomes. the plasma membranes were purified by discontinuous density gradient centrifugation in alkaline buffer containing sucrose and magnesium. the yield of plasma membrane was 3.7 mg of protein per 10(9) epimastigotes, accounting for approximately 4.2% of the total cell proteins. the plasma membrane obtained from the 34- ... | 1986 | 3027922 |
| [high correlation between isoenzyme classification and kinetoplast dna variability in trypanosoma cruzi]. | by means of 14 restriction enzymes, we have studied the kinetoplast dna polymorphism in 21 trypanosoma cruzi isolates previously classified into 19 different genotypes based on the analysis of 15 isozyme loci. we have found a high correlation (p less than 0.001) between the proportion of restriction bands (fragments) common to any two given isolates and the corresponding genetic identities calculated from the isozyme data. this shows that the two classifications (kdna and isozymes) corrobate one ... | 1987 | 3030516 |
| the effects of p-chloromercuriphenylsulfonic acid on trypanosoma cruzi infection of mammalian host cells in vitro. | treatment of trypanosoma cruzi blood trypomastigotes with p-chloromercuriphenylsulfonic acid (pcms) increased the association of the parasite with either mouse resident peritoneal macrophages or rat heart myoblasts in vitro. the effect was evidenced by elevation of both the percentage of host cells with parasites and the number of flagellates per 100 cells. the effect of pcms appeared to be largely on the process of parasite penetration rather than surface binding as it was seen at 37 degrees c ... | 1987 | 3033500 |
| fructose 1,6-bisphosphatase activity in two trypanosoma cruzi morphological forms. | 1987 | 3035158 | |
| detection of leishmania parasites by dna in situ hybridization with non-radioactive probes. | in situ hybridization techniques develop rapidly into diagnostic tools of considerable value for detection of viruses and bacteria. here we report the application of this technique for the detection of leishmania parasites. biotin-labelled total promastigote dna was hybridized to cultured leishmania parasites and to blood and impression smears of infected mice. in promastigotes kinetoplasts were strongly stained, nuclei somewhat more diffuse. in amastigotes both nuclear and kinetoplast dna hybri ... | 1987 | 3035535 |
| defective transport of pyrazolopyrimidine ribosides in insensitive trypanosoma cruzi wild strains is a parasite-stage specific and reversible characteristic. | 1. by using freshly isolated blood trypomastigotes of twelve t. cruzi wild type strains we have found eight strains sensitive to fob and foa, while four and one were foa- and fob-insensitive respectively to the drug-mediated growth inhibition. 2. this was not so for appr, to which most strains were transitory insensitive except two which were clearly sensitive. 3. all these pyrazolopyrimidines blocked trypomastigote-amastigote transformation. 4. incubation of pyrazolopyrimidine-insensitive wild ... | 1987 | 3040328 |
| biochemical characterization of a factor produced by trypomastigotes of trypanosoma cruzi that accelerates the decay of complement c3 convertases. | infective- and vertebrate-stage trypomastigotes of trypanosoma cruzi resist serum killing by the alternative complement pathway, whereas noninfective vector-stage epimastigotes, from which trypomastigotes derive, are serum-sensitive. this form of developmental preadaption is commonly observed in protozoan parasites, but its mechanisms are poorly understood. we have demonstrated previously that trypomastigotes spontaneously shed molecules which interfere with formation and accelerate the intrinsi ... | 1988 | 3042767 |
| amastigotes of trypanosoma cruzi sustain an infective cycle in mammalian cells. | the two main stages of development of the protozoan parasite trypanosoma cruzi found in the vertebrate host are the trypomastigote and the amastigote. it has been generally assumed that only trypomastigotes are capable of entering cells and that amastigotes are the intracellular replicative form of the parasite. we show here that after incubation for 4 h with human monocytes in vitro 90% or more of extracellularly derived (24 h) amastigotes of t. cruzi are taken up by the cells. within 2 h they ... | 1988 | 3045248 |
| a tubulin-related 55 kilodalton surface antigen recognized by different trypanosoma cruzi stage-specific monoclonal antibodies from infected mice. | thirteen monoclonal antibodies (mabs) specific for the membrane of live trypanosoma cruzi have been obtained from balb/c infected mice. most of them had greater avidity for intact than for disrupted parasites. according to the staining by indirect immunofluorescence of the different live developmental stages of the parasite the mabs could be divided into several groups. three of them were trypomastigote specific, one amastigote-specific and two epimastigote-specific. the rest reacted with either ... | 1988 | 3045540 |
| alterations in intracellular calcium following infection of human endothelial cells with trypanosoma cruzi. | trypanosoma cruzi infection in cultured human umbilical vein endothelial cells increased basal cellular calcium levels from 55 to 110 nm, as monitored with the fluorescent probe, fura-2. it also influenced intracellular calcium such that consistently higher total levels were observed in response to bradykinin, angiotensin ii and norepinephrine, as compared to similarly treated uninfected cells. however, bradykinin and angiotensin ii-dependent increases in calcium, when considered as the absolute ... | 1988 | 3045542 |
| host-cell attachment by trypanosoma cruzi: identification of an adhesion molecule. | we have identified an 83 kda surface glycoprotein in t. cruzi trypomastigotes which specifically binds to rat heart myoblasts. the binding of this molecule to myoblasts is inhibited by excess unlabeled material and saturable. antibodies against the cell surface of insect trypomastigotes, blood trypomastigotes and produced during human infection recognize the 83 kda glycoprotein adhesion molecule by immunoblotting, indicating that this molecule that mediates this critical step is immunogenic and ... | 1988 | 3046614 |
| 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 |
| immunohistochemical detection of deposits of eosinophil-derived neurotoxin and eosinophil peroxidase in the myocardium of patients with chagas' disease. | an immunohistochemical study of eosinophil distribution in the inflammatory cell infiltrates of four different types of myocardial lesions associated with chagas' disease--caused by trypanosoma cruzi--showed larger numbers of these cells in areas presenting tissue necrosis and degeneration, most notably in patients with the most severe myocarditis from a histopathological stand-point. using antisera specific for human eosinophil-derived neurotoxin or eosinophil peroxidase, we detected deposits o ... | 1988 | 3049321 |
| study on the mutagenicity of nifurtimox and eight derivatives with the l-arabinose resistance test of salmonella typhimurium. | the mutagenicity of nifurtimox (nfx) and 8 nfx analogues has been investigated with the l-arabinose forward-mutation assay of salmonella typhimurium. the nfx analogues tested were obtained by replacing the 3-methyl-4-yl-tetrahydro-1,4-thiazine-1,1-dioxide group of the parent compound with the following other groups: indazol-1-yl (1); pyrazol-1-yl (2); benzimidazol-1-yl (3); 1,2,4-triazol-4-yl (4); 1-methyl-3-methylthio-1,2,4-triazol-4-yl-5-thione (5); 3,5-bis(methylthio)-1,2,4-triazol-4-yl (6); ... | 1988 | 3050499 |
| reactivity of stage-specific monoclonal antibody 1g7 with metacyclic trypomastigotes of trypanosoma cruzi strains: lytic property and 90,000 mol. wt surface antigen polymorphism. | eleven strains of trypanosoma cruzi, originating from a variety of vertebrate and invertebrate hosts in distinct geographical regions, were examined for the reactivity of metacyclic stages with the monoclonal antibody 1g7. trypomastigotes of five strains were susceptible to complement-dependent 1g7-mediated lysis. higher levels of 1g7 bound to metacyclics of lysis-susceptible strains as compared to lysis-resistant isolates. excluding y and cl strains, 1g7 reacted with metacyclics of all t. cruzi ... | 1988 | 3050800 |
| screening of drugs for rapid activity against trypanosoma cruzi trypomastigotes in vitro. | previous studies to find drugs with an existing product licence which were active at 4 degrees c within 24 hours and which would be suitable to prevent the transmission of chagas' disease during blood transfusion were unsuccessful. as part of an alternative approach to identify drugs active at 37 degrees c or 25 degrees c within 2 hours, over 280 compounds were screened against bloodstream trypomastigotes of trypanosoma cruzi sonya strain in a microslide test in vitro. although compounds from a ... | 1988 | 3051293 |
| developmental time and mortality of larvae of triatoma infestans infected with trypanosoma cruzi. | triatoma infestans were infected with trypanosoma cruzi (zymodeme 1) at the first feed after eclosion from the egg; interstadial development times and mortality rates were then recorded until the imaginal moult and compared with those of uninfected controls. no retardation of development occurred in infected bugs and their mean total mortality rate (9%) was only slightly higher than that (6%) of uninfected controls (due solely to 4 additional deaths). this is the first demonstration, under optim ... | 1988 | 3051552 |
| enzyme immunoassay in cell monolayers for evaluation of in vitro activity of chemotherapeutic agents against trypanosoma cruzi. | a standardized enzyme-linked immunosorbent assay (elisa), performed directly on monolayers of mouse peritoneal macrophages or l 929 fibroblasts, was used to evaluate the activity of chemotherapeutic agents against four different stocks of trypanosoma cruzi. absorbance readings, performed in an automatic elisa reader, were directly related to the number of intracellular parasites as determined by microscopic examination of tissue culture slides run in parallel. results were highly reproducible in ... | 1988 | 3052120 |
| inhibition of xanthine dehydrogenase from triatoma infestans by some purine analogues. | xanthine dehydrogenase (ec 1.2.1.37) activity was determined in the fat body of the chagas' disease vector triatoma infestans using a system in which phenazine methosulphate was associated with p-iodonitrotetrazolium violet as electron acceptors for the oxidation of the substrate xanthine. under the standard conditions used, xanthine was the substrate of choice. the apparent michaelis-menten constant (km) for xanthine was found to be 0.217 +/- 0.020 mm (mean +/- standard deviation of four indepe ... | 1988 | 3052441 |
| interaction of benznidazole reactive metabolites with nuclear and kinetoplastic dna, proteins and lipids from trypanosoma cruzi. | epimastigotes of trypanosoma cruzi (tulahuen strain tul 0 stock) biotransform benznidazole (n-benzyl-2-nitro-1-imidazole acetamide) to reactive metabolites that bind covalently to dna, proteins and lipids of the parasite. these effects might be related to the trypanocidal action of benznidazole, a chemotherapeutic agent against chagas' disease. | 1988 | 3053234 |
| the glycoconjugates of mammalian parasites with particular reference to trypanosoma cruzi. | 1988 | 3053286 | |
| characterization of dolichol diphosphate oligosaccharide: protein oligosaccharyltransferase and glycoprotein-processing glucosidases occurring in trypanosomatid protozoa. | we have previously reported that the oligosaccharides transferred in vivo from dolichol-p-p derivatives in protein n-glycosylation in trypanosomatids are devoid of glucose residues and contain 2 n-acetylglucosamine and 6, 7, or 9 mannose units depending on the species. in this respect trypanosomatids differ from wild type mammalian, plant, insect, and fungal cells in which glc3man9glcnac2 is transferred. we are now reporting that incubation of glc1-3man9glcnac2-p-p-dolichol and man7-9glcnac2-p-p ... | 1988 | 3053710 |
| trypanosoma cruzi: elemental composition heterogeneity of cloned stocks. | concentrates of the epimastigote stage of trypanosoma cruzi stocks derived from single cell clones and cultured under identical conditions display a spectrum of 'colors' varying from dark brown to milk white. the color of the concentrate is reproducible for a parasite stock. an essential component of the culture medium for epimastigote growth is hemin, an iron-containing compound. consequently, it seemed possible that the color spectrum of the epimastigote stocks reflected differences in the upt ... | 1988 | 3054539 |
| nucleoside uptake in trypanosoma cruzi: analysis of a mutant resistant to tubercidin. | nucleoside salvage pathways are vital to the parasitic protozoan trypanosoma cruzi, and have become important targets in the development of new chemotherapeutic agents against this organism. we produced a mutant t. cruzi clone with a defect in the uptake of the adenosine analogue tubercidin which allowed us to hypothesize that there are at least two distinct nucleoside transport pathways in this parasite. the mutant shows a marked defect in the uptake of tubercidin and thymidine, whereas the upt ... | 1988 | 3054542 |
| diagnosis of parasitic diseases using dna-to-dna hybridization. | 1988 | 3055460 | |
| antiproliferative synergism of the allylamine sf 86-327 and ketoconazole on epimastigotes and amastigotes of trypanosoma (schizotrypanum) cruzi. | we have investigated the growth-inhibitory effects of two ergosterol biosynthesis inhibitors, the dioxolane imidazole ketoconazole and the allylamine sf 86-327, alone and in combination, on the proliferative stages of trypanosoma (schizotrypanum) cruzi, the causative agent of chagas' disease. proliferation of epimastigotes in liver infusion-tryptose medium at 28 degrees c was immediately arrested by any of these drugs at greater than or equal to 3 x 10(-5) m; cell lysis occurred 24 h later. belo ... | 1988 | 3056256 |
| trypanosoma cruzi: studies on the interactions of lectins with glycoconjugates of different zymodemes. | detergent extracts were made of eight strains of trypanosoma cruzi which were representative of the principal zymodemes. the extracts were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the glycoproteins were reacted with 21 different 125i-labeled lectins and autoradiographed. the staining patterns with particular lectins varied considerably between strains. concanavalin a stained up to 17 distinct bands in some strains. other lectins such as peanut lectin only staine ... | 1988 | 3056738 |
| relative resistance of brazil strain trypomastigote forms of trypanosoma cruzi to in vitro antibody-dependent complement-mediated lysis. | various assay conditions were employed in experiments examining the susceptibility of trypomastigote forms of the brazil strain of trypanosoma cruzi to antibody-dependent complement-mediated lysis. to identify optimal assay conditions, both guinea pig serum and normal human serum were used as complement sources, and fibroblast-derived or blood-form trypomastigotes were either coincubated with immune sera and complement together, or the parasites were first precoated with antibodies and then were ... | 1988 | 3057163 |
| development of isolated and group-reared first instars of triatoma infestans infected with trypanosoma cruzi. | 1988 | 3057492 | |
| activity of p536, a udp-glucose analog, against trypanosoma cruzi. | p536, a udp-glucose analog which was previously described as an antiviral agent (m. j. camaraza, p. fernández resa, m. t. garcía lópez, f. g. de las heras, p. p. mendez-castrillón, b. alarcón, and l. carrasco, j. med. chem. 28:40-46, 1985), has a potent and selective activity against the intracellular and extracellular stages of trypanosoma cruzi in vitro. it had a 50% inhibitory concentration of less than 5 micrograms/ml for t. cruzi extracellular cultured forms (epimastigote) and of 25 microgr ... | 1988 | 3058022 |
| differential energetic metabolism during trypanosoma cruzi differentiation. i. citrate synthase, nadp-isocitrate dehydrogenase, and succinate dehydrogenase. | the activities of the mitochondrial enzymes citrate synthase (citrate oxaloacetatelyase, ec 4.1.3.7), nadp-linked isocitrate dehydrogenase (threo-ds-isocitrate:nadp+ oxidoreductase (decarboxylating), ec 1.1.1.42), and succinate dehydrogenase (succinate: fad oxidoreductase, ec 1.3.99.1) as well as their kinetic behavior in the two developmental forms of trypanosoma cruzi at insect vector stage, epimastigotes and infective metacyclic trypomastigotes, were studied. the results presented in this wor ... | 1988 | 3058038 |
| trypanosoma cruzi: cell biological behavior of epimastigote and amastigote forms in axenic culture. | a simple protocol to maintain trypanosoma cruzi amastigote stocks indefinitely in axenic culture is described. the growth characteristics of amastigotes differ markedly from epimastigotes cultured under identical conditions. the amastigotes replicate for two generations, followed by a transformation to epimastigotes and resumption of growth. by changing the culture medium at the end of the second amastigote generation, transformation to epimastigotes is inhibited. therefore, the protocol used to ... | 1988 | 3058949 |
| synergistic effects of ketoconazole and sf-86327 on the proliferation of epimastigotes and amastigotes of trypanosoma (schizotrypanum) cruzi. | 1988 | 3063176 | |
| cardiac morbidity due to chagas' disease in a rural community in bolivia. | the prevalence of cardiac morbidity due to chagas' disease was assessed in a rural community in central bolivia. sixty-nine of 104 persons (66%) were seropositive to trypanosoma cruzi by two serological methods. two of 35 (6%) seronegative individuals presented with modest ecg alterations (left anterior hemiblock), but 21 of 69 (30%) seropositives showed modest and severe abnormalities (6 complete right bundle branch block, 2 polyfocal or frequent extrasystoles, 9 ischaemic st alterations). a hi ... | 1988 | 3063552 |
| modification of the pattern of infection and evolution of cardiopathy in experimental chagas' disease after treatment with immunosuppressive and trypanocidal drugs. | 1988 | 3063916 | |
| the use of albumin-gold to follow lysosome-phagosome fusion. | a new procedure for labeling of secondary lysosomes and to determine, by transmission electron microscopy, their fusion with phagosomes was developed. it is based on the use of albumin adsorbed to colloidal gold particles as a probe and tested using macrophages previously labeled with albumin-gold and then incubated in the presence of epimastigote forms of trypanosoma cruzi. | 1988 | 3066470 |
| genomic dna sequence polymorphism of trypanosoma (schizotrypanum) cruzi isolates with phenotypic variation. | 1. single-copy dna sequences were analyzed by molecular hybridization to determine both the extent of complementarity and time of evolutionary divergence between three isolates obtained from argentina, mexico or venezuela. 2. the mexico-venezuela pair appeared much closer than the mexico-argentina pair. 3. the tentative values for time of evolutionary divergence were higher than those estimated previously by allozymic variation. | 1988 | 3066577 |
| tubulin expression in trypanosomes. | microtubules in trypanosomes are the main component of the flagellar axoneme and of the subpellicular microtubule corset, whose relative positions determine the morphology of each cell stage of the life cycle of these parasites. microtubules are polymers of tubulin, a protein dimer of two 55-kda subunits, alpha- and beta-tubulin; in trypanosoma brucei, the tubulin-coding sequences are clustered in a 40-kb fragment of tandemly repeated alpha- and beta-tubulin genes separated by a 170-bp intergeni ... | 1988 | 3067795 |
| the detection of a spectrin-like protein in trypanosoma cruzi with a polyclonal antibody. | a rabbit serum raised against sheep erythrocyte spectrin stained mainly the flagella of epimastigote forms of the parasitic protozoan trypanosoma cruzi. in western blots of t. cruzi proteins solubilized with nonidet p-40 it recognized mainly a polypeptide doublet with an apparent molecular weight of about 240 kda, while a pre-immune rabbit serum and a tubulin monoclonal antibody did not. the results are consistent with the idea that a spectrin-like protein may be involved in cytoskeleton-membran ... | 1988 | 3067862 |
| [observations on kala azar in jacobina, bahia. vi. investigations on sylvatic and commensal mammals]. | 1988 | 3068712 | |
| [behavior of the infection and morphologic differentiation of trypanosoma cruzi and t. rangeli in the intestine of the vector rhodnius prolixus]. | 1988 | 3070649 | |
| rheumatoid factors in leprosy and parasitic diseases. | rheumatoid factors (rfs) occur with higher frequency and in higher titres in multibacillary forms of leprosy and several parasitic diseases than in healthy controls. the selection of controls is essential in studies of this kind. they should be individuals without signs of the disease under study living under similar socioeconomic conditions as the patients in the endemic country. in three studies where this matter was considered, rfs in lepromatous leprosy and chagas' disease reacted more stron ... | 1988 | 3070728 |
| urban trypanosoma cruzi: biological characterization of isolates from panstrongylus geniculatus. | 1988 | 3071279 | |
| biological aspects of the dm 28c clone of trypanosoma cruzi after metacyclogenesis in chemically defined media. | the biological characterization of the trypanosoma cruzi clone dm 28c in terms of its growth in lit medium, cell-cycle, infectivity to mice and interaction with professional and non-professional phagocytic cells shows that it behaves as a bona fide t. cruzi representant. the biological properties of this myotropic clone do not change according to the origin of the trypomastigote forms (i. e., from triatomines, infected mice, cell-culture or from the chemically defined taup and tau3aag media). in ... | 1988 | 3074237 |
| presence of trypanosoma cruzi in the anal glands of naturally infected opossum (didelphis marsupialis) in the state of santa catarina, brazil. | 1988 | 3074238 |