Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| improved leishmanicidal effect of phosphorotioate antisense oligonucleotides by ldl-mediated delivery. | we have designed antisense oligonucleotides that can interact with lipoproteins in order to use them as vectors to facilitate the uptake by those cells expressing the corresponding receptor. phosphorothioate (ps) oligonucleotides were linked at the 5' end to a palmityl group giving rise to pspal conjugates. such a modification enables the oligonucleotide to form a stable non-covalent complex with low density lipoproteins (ldl) through hydrophobic interactions. the antisense effect of ldl-oligonu ... | 1995 | 7495868 |
| differential expression of the plasma membrane mg2+ atpase and ca2+ atpase activity during adhesion and interiorization of leishmania amazonensis in fibroblasts in vitro. | with ultrastructural cytochemistry we localized the activity of the plasma membrane enzyme markers mg2+ atpase and ca2+ atpase during the interaction between leishmania amazonensis and in vitro primary culture fibroblasts. the expression of the enzymes was followed during the parasite adhesion and its interiorization. after the interiorization step, a striking difference was seen between the two enzymes studied when the parasite was found within the parasitophorous vacuole in the fibroblast cyto ... | 1995 | 7671216 |
| leishmania amazonensis: sensitivity of different promastigote morphotypes to salivary gland homogenates of the sand fly lutzomyia longipalpis. | we have recently demonstrated that lutzomyia longipalpis salivary gland homogenates (sgh) inhibited the multiplication of leishmania promastigotes in vitro. the present work shows that leishmania amazonensis sensitivity to sgh is correlated to the phase of promastigote in vitro growth and can be decreased by the addition of hemin to the culture medium. the possible relevance of these in vitro results is discussed in relation to the development of leishmania parasites within their sand fly vector ... | 1995 | 7895828 |
| spontaneous regional healing of extensive skin lesions in diffuse cutaneous leishmaniasis (dcl). | the authors report a case of diffuse cutaneous leishmaniasis, with longstanding evolution and presenting with diffuse infiltrated lesions rich in amastigotes in the absence of mucosal involvement. in situ characterization with monoclonal antibodies revealed leishmania amazonensis. large regional lesions have presented spontaneous healing without specific therapy. considering that dcl presents with a defect in the cellular immune response, this fact demonstrate that this patient may develop a reg ... | 1995 | 7724867 |
| cytotoxicity in human mucosal and cutaneous leishmaniasis. | cd8+ t cells and lysis of parasitized macrophages seem to be important in the resistance to murine leishmaniasis. in the present study, we evaluated peripheral blood mononuclear cell (pbmc) from patients with either cutaneous (cl) or mucosal (ml) leishmaniasis in cell lysis assays using 51-cr-labeled daudi or k562 cells, or autologous antigen-pulsed macrophages as targets. results are reported as lytic units (number of cells required for 30% lysis) per million pbmc. exposure of patient pbmc (n = ... | 1995 | 7731732 |
| genetic rescue of surface metalloproteinase (gp63)-deficiency in leishmania amazonensis variants increases their infection of macrophages at the early phase. | 1994 | 7808483 | |
| fusion between large phagocytic vesicles: targeting of yeast and other particulates to phagolysosomes that shelter the bacterium coxiella burnetii or the protozoan leishmania amazonensis in chinese hamster ovary cells. | this report examines the fusion of phagocytic vesicles with the large phagolysosome-like vacuoles induced in chinese hamster ovary cells by the bacterium coxiella burnetti or the protozoan flagellate leishmania amazonensis. infection by these organisms is compatible with cell survival and multiplication. fusion was inferred from the transfer of microscopically identifiable particles from donor to target vesicles. donor vesicles contained heat-killed yeast, zymosan, beta-glucan or latex beads tak ... | 1994 | 7699006 |
| distribution of mhc class i and of mhc class ii molecules in macrophages infected with leishmania amazonensis. | macrophages, being apparently the only cells that in vivo allow the growth of the intracellular pathogen leishmania, are likely candidates to present antigens to leishmania-specific cd4+ and cd8+ t lymphocytes, known to be involved in the resolution or in the development of lesions induced by these parasites, and recognizing processed antigens bound to mhc class i and mhc class ii molecules, respectively. in the present study, we analysed by confocal microscopy and by immunoelectron microscopy t ... | 1994 | 8175924 |
| effect of in vivo depletion of cd4+ t cells on experimental infection of susceptible balb/c mice with leishmania amazonensis. | the role played by cd4+ t lymphocytes in susceptible balb/c mice infected with leishmania amazonensis was investigated. depletion of cd4+ t cells was achieved in experimentally infected mice by means of treatment with anti-cd4 monoclonal antibody (mab), resulting in significant reductions in the size of lesions and in mortality when compared with control animals. moreover, the parasite load in the depleted mice, as quantified by limiting dilution analysis, was about 10-times lower than in the co ... | 1994 | 7911268 |
| detection of ubiquinone in parasitic and free-living protozoa, including species devoid of mitochondria. | ubiquinone (coenzyme q, coq) was analyzed and individual homologues quantified in 11 species of parasitic and free-living protozoa by a combination of thin-layer chromatography and high performance liquid chromatography. fast atom bombardment ionization-mass spectrometry was used for the first time to confirm the identity of the fractionated coq homologues and proved to be a fast, gentle and convenient method for ubiquinone identification. ubiquinone was detected in all organisms including those ... | 1994 | 7969263 |
| functional analysis of cis-acting dna elements required for expression of the sl rna gene in the parasitic protozoan leishmania amazonensis. | dna sequences, that control expression of the spliced leader (sl) rna gene in the parasitic protozoan leishmania amazonensis, were mapped by block substitution mutagenesis. in the absence of a functional in vitro system for transcription, no promoter elements have yet been identified in this organism. we therefore developed an alternative in vivo approach, in which the sl rna gene was tagged and then subjected to a series of linker scanning mutations. each tagged and mutated sl rna construct was ... | 1994 | 8029000 |
| specific a+t-rich repetitive dna sequences in maxicircles from wildtype leishmania mexicana amazonensis and variants with dna amplification. | to explain the low cross-hybridization between kinetoplast dna maxicircles of leishmania parasites that show dna amplification and those of parasites without dna amplification, we isolated and cloned two maxicircle fragments, one specific to each group of parasites. the cloned fragment from wildtype l. m. amazonensis (mbpw94) and that from an arsenite-resistant variant with dna amplification (mpba29) hybridized only to maxicircles from parasites of the group from which the fragment was originall ... | 1994 | 8050523 |
| isomeric and quaternary properties of homogenous 33 kda protein from the venom of chelonus near curvimaculatus. | the 33,000 dalton venom protein of chelonus near curvimaculatus was characterized for structural properties of charge, quaternary associations, and relationship to polydnavirus encoded proteins. homogenous isoforms of the protein were isolated from the venom by sequential steps of 1) microdissection, 2) separation based on charge (mono-q column hplc or narrow-range electrofocusing), and 3) centrifugal filtration based on molecular weight using centricon microconcentrators. the purified protein d ... | 1994 | 8054662 |
| antisense phosphorothioate oligonucleotides: selective killing of the intracellular parasite leishmania amazonensis. | we targeted the mini-exon sequence, present at the 5' end of every mrna of the protozoan parasite leishmania amazonensis, by phosphorothioate oligonucleotides. a complementary 16-mer (16ps) was able to kill amastigotes--the intracellular stage of the parasite--in murine macrophages in culture. after 24 hr of incubation with 10 microm 16ps, about 30% infected macrophages were cured. the oligomer 16ps acted through antisense hybridization in a sequence-dependent way; no effect on parasites was obs ... | 1994 | 8058724 |
| identification of a putative pore-forming hemolysin active at acid ph in leishmania amazonensis. | several organisms, including the protozoa entamoeba histolytica and trypanosoma cruzi, have been shown to contain pore-forming proteins (pfp) thought to play a role in the pathogenesis of the diseases they generate. in the present report, we show that promastigotes of leishmania amazonensis express a hemolysin that appears to cause colloid-osmotic lysis, typical of pore formation. this hemolysin affects red blood cells of different species at 37 degrees c, but not at 0 degrees c, with maximum ac ... | 1994 | 8081268 |
| relative contribution of photo-addition, helper oligonucleotide and rnase h to the antisense effect of psoralen-oligonucleotide conjugates, on in vitro translation of leishmania mrnas. | we investigated the properties of two antisense oligonucleotides, 11 alpha pso and 14tmp, 11 and 14 nucleotides long, respectively, and conjugated to psoralen derivatives. these oligonucleotides were complementary to the mini-exon sequence of leishmania amazonensis. upon ultraviolet (uv) irradiation these oligomers were selectively cross-linked to dna or rna target sequences, either 14 or 35 nucleotides long. the yield of photo-addition was much lower on the longer targets than on the shorter on ... | 1994 | 8086483 |
| selection for arsenite resistance causes reversible changes in minicircle composition and kinetoplast organization in leishmania mexicana. | certain minor minicircle sequence classes in the kinetoplast dna (kdna) networks of arsenite- or tunicamycin-resistant leishmania mexicana amazonensis variants whose nuclear dna is amplified appear to be preferentially selected to replicate (s. t. lee, c. tarn, and k. p. chang, mol. biochem. parasitol. 58:187-204, 1993). these sequences replace the predominant wild-type minicircle sequences to become dominant species in the kdna network. the switch from wild-type-specific to variant-specific min ... | 1994 | 8264626 |
| an experimental model of the production of metastases in murine cutaneous leishmaniasis. | an experimental investigation into the influence of artificially induced trauma in the production of leishmanial metastatic lesions and into the possible role played by leishmania-reactive t cell populations in the metastatic process was carried out. trauma was induced by incising a small cut into the shaved rump of leishmania amazonensis-infected balb/c mice. ten days after the trauma, mice were killed to quantify the parasite load in the traumatic lesion or in the equivalent area in nontraumat ... | 1994 | 8308664 |
| [histopathology of the localized form of cutaneous leishmaniasis caused by leishmania (leishmania) amazonensis]. | the microscopic changes found in the localized form of the human cutaneous leishmaniasis due to leishmania (leishmania) amazonensis are reported. in this form, less known than the diffuse one caused by the same species, the clinical manifestations are identical to those produced by other leishmania species of the subgenus viannia. there is, however, in the localized infection by l. (l.) amazonensis, a peculiar feature, only recently discovered: about 50% of the affected individuals are montenegr ... | 1994 | 7569614 |
| the biosynthesis, processing, and immunolocalization of leishmania pifanoi amastigote cysteine proteinases. | biosynthesis, enzymatic processing, and immunocytochemical localization of an abundant developmentally regulated cysteine proteinase of leishmania pifanoi, lpcys2, were investigated employing axenic cultured amastigotes and monoclonal antibodies specifically recognizing either the mature proteinase or the carboxy-terminal extension domain. pulse labeling and protein sequence data indicated that a 45-kda precursor is processed to a 40-kda intermediate, which is further cleaved to generate the 27- ... | 1994 | 7891736 |
| glycosphingolipid antigens of leishmania (leishmania) amazonensis amastigotes identified by use of a monoclonal antibody. | monoclonal antibodies directed against leishmania (leishmania) amazonensis amastigotes were produced. one monoclonal antibody (1c3) selected by indirect immunofluorescence reacted with both amastigotes and promastigotes of l. (l.) amazonensis. glycolipid extraction from l. (l.) amazonensis amastigotes and separation by high-performance thin-layer chromatography followed by immunoblotting demonstrated that 1c3 reacts with two glycosphingolipids which migrate chromatographically similarly to ceram ... | 1993 | 7683002 |
| fructose 2,6 bisphosphate promotes the monomer-tetramer conservation of leishmania mexicana amazonensis pyruvate kinase type two. | the enzyme pyruvate kinase of leishmania mexicana amazonensis presents two forms with different kinetic properties and behavior for the heterotrophic activator fructose 2,6 bisphosphate. pyruvate kinase 1, which is isolated as a tetramer, is inhibited by this metabolite. the second activity, pyruvate kinase 2, is activated by fructose 2,6 bisphosphate, which promotes the monomer-tetramer conversion of this enzyme. | 1993 | 7670525 |
| identification of gtpase genes in the protozoa parasites trypanosoma cruzi and leishmania amazonensis. | a pcr based assay was designed in order to amplify putative ras gene sequences of the gtpase superfamily eventually present in leishmania amazonensis and trypanosoma cruzi. a set of primers corresponding to the conserved motifs g1 and g3 of the gtp binding proteins was synthesized. sequencing of six pcr products (three from leishmania and three from trypanosoma) identified, however, two other different gtpases. the 270 bp l. amazonensis clone, plef-11, shared an amino acid identity of around 80% ... | 1993 | 7670542 |
| induction of complement-sensitivity in leishmania amazonensis metacyclic promastigotes by protease treatment but not by specific antibodies. | 1993 | 8327457 | |
| cytostatic effect of lutzomyia longipalpis salivary gland homogenates on leishmania parasites. | salivary gland homogenates (sgh) of female lutzomyia longipalpis, in concentrations as small as 0.05 pairs of glands/ml, inhibit the in vitro multiplication of promastigotes of leishmania mexicana amazonensis. the effect seems to be cytostatic since promastigote viability 24 hr after exposure ranged from 55% to 100% in different experiments. the cells cultivated in the presence of sgh were characterized by a very slender shape, with cell bodies that were almost two times as long as controls. the ... | 1993 | 8333578 |
| recombinant vaccinia viruses expressing gp46/m-2 protect against leishmania infection. | leishmania is a genus of parasitic protozoa capable of causing a spectrum of human diseases. the gp46/m-2 membrane glycoprotein has been demonstrated in a murine model system to elicit a protective immune response against infection with leishmania amazonensis; in highly susceptible balb/c mice, immunization leads to significant protection against infection. in the present study, for induction of long-term immunological effects, two recombinant vaccinia viruses, derived from the wild type and att ... | 1993 | 8335366 |
| effects of sinefungin on growth and sterol composition of leishmania promastigotes. | the s-adenosylmethionine analogue sinefungin was tested in vitro against promastigotes of various strains of leishmania. the ic50 values for the leishmania mexicana, leishmania major, and leishmania donovani strains used were of the order of 10 ng/ml but the leishmania amazonensis strain tested was more resistant to the drug, the ic50 value being 6 micrograms/ml. sterol profiles, in which 24-alkyl (c28) sterols predominated, were relatively unaffected by sinefungin. incorporation of label derive ... | 1993 | 8375483 |
| antigen-reactive gamma delta t cells in human leishmaniasis. | the importance of ag-specific gamma delta t lymphocytes in human immune responses to pathogenic organisms is unknown. in the present study the expression of gamma delta tcr on t lymphocytes from patients with cutaneous, mucosal, or visceral leishmaniasis was examined. all of these patient groups had elevated levels of gamma delta t cells in peripheral blood. patients' gamma delta t cells included cd8+ as well as null cells. the percentage of t cells expressing gamma delta tcr was increased signi ... | 1993 | 8376802 |
| characterization of the switch of kinetoplast dna minicircle dominance during development and reversion of drug resistance in leishmania. | to characterize the differences between kdna minicircles of drug-resistant leishmania mexicana amazonensis variants that show nuclear dna amplification and minicircles of variants without nuclear dna amplification, we sequenced minicircles from repeatedly cloned parasites. the dominant minicircles from arsenite- and tunicamycin-resistant parasites with dna amplification were found to preexist as minor conserved divergent classes in parental wild-type cells. these classes shared very limited simi ... | 1993 | 8386802 |
| molecular cloning and characterization of a 42-kda protein phosphatase of leishmania chagasi. | using rabbit serum raised against a potent t cell-stimulating antigen fraction of leishmania chagasi promastigotes, we have cloned and expressed the leishmania type 2c serine/threonine protein phosphatase, lcpp2c. lcpp2c was shown to be present as a 42-kda protein in both the infective promastigote and tissue amastigote stages of l. chagasi and leishmania amazonensis. dna hybridization studies established the close conservation of lcpp2c among eight of eight geographically diverse species of lei ... | 1993 | 8394331 |
| isolation of two pyruvate kinase activities in the parasitic protozoan leishmania mexicana amazonensis. | using phosphocellulose affinity chromatography we were able to separate two pyruvate kinase (ec 2.7.1.40) activities in the parasitic protozoan leishmania mexicana amazonesis. one activity (pyk1) showed hyperbolic kinetics and was decreased by fructose 2,6-bisphosphate, whereas the second activity (pyk2) showed sigmoidal kinetics for the substrate phosphoenolpyruvate and was activated by fructose 2,6-bisphosphate. molecular sieve chromatography (sephacryl s-400) of pyk1 produced a single peak of ... | 1993 | 8424681 |
| leishmania mexicana amazonensis: effect of heat shock on the spliced leader rna and its ribonucleoprotein particle sl rnp. | trypanosomatid parasites of the genus leishmania experience a temperature shift from 22-38 degrees c to 33-37 degrees c while being transmitted from the invertebrate vector to the mammalian host. expression of many protein-coding genes in protozoan parasites that cycle between two hosts have been shown to be thermosensitive, and temperature changes most probably serve as a major regulatory factor during stage differentiation. we present here our studies on effects of physiological temperature sh ... | 1993 | 8467899 |
| cutaneous leishmaniasis in mast cell-deficient w/wv mice. | genetically mast cell-deficient w/wv mice infected with leishmania amazonensis showed progressive development of ulcerative skin lesions. however, no significant differences between the w/wv mice and the normal littermates with respect to size of the lesions, anti-leishmania immunoglobulin e antibody, and the number of eosinophils accumulated in the lesions were observed. | 1993 | 8478118 |
| 2-substituted quinoline alkaloids as potential antileishmanial drugs. | ten 2-substituted quinoline alkaloids isolated from a plant used for treatment of new world cutaneous leishmaniasis have antileishmanial in vitro activities against the extracellular forms of leishmania spp. balb/c mice infected with leishmania amazonensis ph8 or h-142 or leishmania venezuelensis were treated 1 day after the parasitic infection with a quinoline alkaloid (100 mg/kg of body weight per day) or with reference drug n-methylglucamine antimonate (glucantime) (56 mg of pentavalent antim ... | 1993 | 8494383 |
| intergenic sequences from the heat-shock protein 83-encoding gene cluster in leishmania mexicana amazonensis promote and regulate reporter gene expression in transfected parasites. | regulation of expression from hsp83 gene cluster encoding heat-shock protein (hsp) 83 of the protozoan parasite leishmania mexicana amazonensis (l.m.a) was examined. the first gene from this cluster, along with 8 kb of flanking sequences, was cloned, and intergenic region (ir) sequences were found upstream from the cluster. l.m.a. parasites were electroporated with a plasmid (pici) in which the chloramphenicol acetyltransferase (cat)-encoding gene (cat) was cloned between two irs derived from an ... | 1993 | 8500758 |
| antisense effect of oligodeoxynucleotides complementary to the mini-exon sequence of the protozoan parasite leishmania amazonensis. | we have targeted the mini-exon of leishmania amazonensis, the sequence present at the 5' end of every mrna of this protozoan parasite, with a complementary 12-mer, either unmodified (12 le ii) or linked to an acridine derivative (12 le ii acr). physical measurements performed either in solution or on nitrocellulose filters showed that the two oligomers exhibited the same affinity for both dna and rna target sequences. furthermore, the two oligomers 12 le ii and 12 le ii acr inhibited in vitro tr ... | 1993 | 8504176 |
| immune responses associated with susceptibility of c57bl/10 mice to leishmania amazonensis. | leishmaniae are protozoans which, depending upon both the host and parasite species, can cause either a healing or nonhealing infection. while c57bl/10 mice are able to heal following infection with leishmania major, they fail to heal following infection with leishmania amazonensis. in order to address the role of th1 and th2 cell responses in the outcome of these infections in c57bl/10 mice, gamma interferon (ifn-gamma) and interleukin-4 (il-4) production was assessed. while cells from l. major ... | 1993 | 8514400 |
| herbicides to curb human parasitic infections: in vitro and in vivo effects of trifluralin on the trypanosomatid protozoans. | leishmaniasis is a major tropical disease for which current chemotherapies, pentavalent antimonials, are inadequate and cause severe side effects. it has been reported that trifluralin, a microtubule-disrupting herbicide, is inhibitory to leishmania amazonensis. in this study, the in vitro effect of trifluralin on different species of trypanosomatid protozoans was determined. in addition to l. amazonensis, trifluralin is effective against leishmania major and leishmania tropica, which cause cuta ... | 1993 | 8516314 |
| t cell response in murine leishmania mexicana amazonensis infection: production of interferon-gamma by cd8+ cells. | the immune response to leishmania major has been the subject of many investigations. however, leishmania includes many species with different clinical manifestations. in this report, we studied the t cell response to l. mexicana amazonensis, a new world species, in a murine model. we found that, similar to l. major, an old world species, resistant c57bl/6 mice produced a high level of ifn-gamma and a low level of il-4. conversely, susceptible balb/c mice produced a much lower level of ifn-gamma ... | 1993 | 8097471 |
| antigen presentation capacity of murine macrophages infected with leishmania amazonensis amastigotes. | leishmania-infected m phi are potential candidates for the presentation of parasite ag to leishmania-specific cd4+ t lymphocytes. to assess whether infected cells could function as apc, we examined the ability of bone marrow-derived m phi infected with leishmania amazonensis amastigotes to stimulate various cd4+, l-ad- or l-ed-restricted t-cell hybridomas specific for the bacteriophage lambda repressor cl protein, the human chorionic gonadotropin or ova. a reduced capacity of infected m phi to p ... | 1993 | 8102156 |
| immunogold labeling and cerium cytochemistry of the enzyme ecto-5'-nucleotidase in promastigote forms of leishmania species. | we have applied both enzyme cytochemistry and immunological labeling techniques to characterize the enzyme 5'-nucleotidase (5'-nase), at the ultrastructural level, in promastigote forms of four leishmania species: leishmania amazonensis, leishmania mexicana, leishmania donovani and leishmania chagasi. the cerium phosphate staining was localized at the surface of the cell body, the flagellum and the flagellar pocket membranes of all the parasites studied. the immunogold labelling technique confir ... | 1993 | 8107602 |
| [disseminated cutaneous leishmaniasis due to leishmania viannia braziliensis in the state of maranhão, brazil]. | the authors describe a case of a patient from barreirinhas, ma with disseminated cutaneous leishmaniasis, who presented 58 lesions spread all over his body, with many different aspects, but ulcerative lesions were predominant. they discuss the difficulty of laboratory diagnosis in the beginning of the investigation and its therapeutics implications. the parasite isolated was identified as leishmania viannia braziliensis using monoclonal antibodies in the fluorescent antibody test. this form of t ... | 1993 | 8128071 |
| sequence and genomic organization of the hsp70 genes of leishmania amazonensis. | the sequence and genomic organization of hsp70 genes in leishmania amazonensis were examined. maps of overlapping cosmid clones revealed that seven l. amazonensis hsp70 genes are organized into a 24-kb locus containing 3.5-kb tandem repeats. cosmids covering a different chromosomal region indicated that an eighth hsp70 sequence is located at a distant site. southern blot data suggested the existence of additional hsp70 genes or pseudogenes. one complete 3.5-kb genomic repeat unit, including codi ... | 1993 | 8139614 |
| a heparin-binding activity on leishmania amastigotes which mediates adhesion to cellular proteoglycans. | the intracellular amastigote form of leishmania is responsible for the cell-to-cell spread of leishmania infection in the mammalian host. in this report, we identify a high-affinity, heparin-binding activity on the surface of the amastigote form of leishmania. amastigotes of leishmania amazonensis bound approximately 120,000 molecules of heparin per cell, with a kd of 8.8 x 10(-8) m. this heparin-binding activity mediates the adhesion of amastigotes to mammalian cells via heparan sulfate proteog ... | 1993 | 8227137 |
| reduced purine accumulation is encoded on an amplified dna in leishmania mexicana amazonensis resistant to toxic nucleosides. | nucleoside analogs are potential anti-leishmania agents. to better understand how these compounds might lose their effectiveness, leishmania were independently selected for resistance to inosine dialdehyde or tubercidin. each of the resistant cells exhibited resistance to inosine dialdehyde and tubercidin as well as to formycin b and allopurinol ribonucleoside. resistant cells had a greatly reduced capability of accumulating exogenous adenosine, guanosine, thymidine and guanine. this decreased a ... | 1993 | 8232410 |
| effect of macrophage infection by leishmania on the proliferation of an antigen-specific t-cell line, tpb1, to a non-parasite antigen. | the ability of leishmania mexicana amazonensis to inhibit antigen specific t-cell proliferation against a non-parasite polypeptide antigen, poly(ltyr, lglu)-poly(dlala)--poly(llys), was examined. infection of mouse peritoneal macrophages by promastigotes blocked the proliferation of the t-cell line, tpb1. this effect was correlated with the level of parasite infection, and the timing of macrophage infection and antigen addition. peritoneal macrophages from both balb/b and c57bl/6 mice showed red ... | 1993 | 8233564 |
| leishmania amazonensis infection: a comparison of in vivo leishmanicidal mechanisms between immunized and naive infected balb/c mice. | in vitro studies have shown that both macrophage activation and destruction of parasitized macrophages lead to leishmania destruction. the relative role played by such mechanisms in vivo have not been properly evaluated. we took advantage of the model of intravenous immunization with solubilized leishmanial antigen which renders partially resistant the otherwise highly susceptible balb/c mice to address this issue avoiding the interference of different genetic backgrounds. leishmania destruction ... | 1992 | 1740178 |
| antigenic differences among leishmania amazonensis isolates and their relationship with distinct clinical forms of the disease. | immunoblot analysis was used to investigate antigenic differences among clinical isolates of leishmania amazonensis and their role in the etiology of the disease. western blots of promastigote homogenates were analyzed with either monoclonal antibodies (mabs) specific for the l. mexicana complex (m-4, m-6, m-9, and m-11) or polyclonal sera from l. amazonensis infected patients with the various forms of clinical disease. in the case of the mabs, no significant variation was observed among the str ... | 1992 | 1284990 |
| effect of natural naphthoquinones in balb/c mice infected with leishmania amazonensis and l. venezuelensis. | plumbagin, 3,3'-biplumbagin and 8,8'-biplumbagin are naphthoquinones isolated by activity-directed fractionation from a bolivian plant, pera benensis, used in folk medicine as treatment of cutaneous leishmaniasis caused by leishmania braziliensis. balb/c mice were infected with l. mexicana or l. venezuelensis and treated 24 h after the parasitic infection with plumbagin (5 or 2.5 mg/kg/day), 3,3'-biplumbagin, 8,8'-biplumbagin (25 mg/kg/d) or glucantime (200 mg/kg/d). lesion development was the c ... | 1992 | 1293723 |
| [the current status of diffuse cutaneous leishmaniasis (dcl) in the state of maranhão. ii. the epidemiological and clinico-evolutionary aspects]. | the authors describe a retrospective and prospective study of 6 patients with diffuse cutaneous leishmaniasis observed in the state of maranhão, since 1974. the patients come from different rural regions of the state and in all of them leishmania (leishmania) amazonensis was the cause five of the patients initiated their disease in the first decade of life. all the patients first had a solitary, nodular lesion, that after a variable period of time, disseminated and acquired other aspects. sequen ... | 1992 | 1308937 |
| interleukin-3 induces antimicrobial activity against leishmania amazonensis and trypanosoma cruzi and tumoricidal activity in human peripheral blood-derived macrophages. | the ability of interleukin-3 (il-3) to induce antimicrobial and tumoricidal activity was evaluated. macrophages infected with two intracellular protozoa, leishmania amazonensis or trypanosoma cruzi, were treated with cytokines. il-3 induced a dose-dependent enhancement of microbistasis against leishmanias, and the activity of il-3 (100 ng/ml) was comparable to that of gamma interferon (ifn-gamma) (1,000 u/ml). in addition, il-3 in combination with either granulocyte-macrophage colony-stimulating ... | 1992 | 1314223 |
| the 63-kilobase circular amplicon of tunicamycin-resistant leishmania amazonensis contains a functional n-acetylglucosamine-1-phosphate transferase gene that can be used as a dominant selectable marker in transfection. | tunicamycin (tm)-resistant leishmania amazonensis has been found previously to contain amplified chromosomal dna, existing exclusively as extrachromosomal circles of 63 kb. fragments of this dna cloned into plasmids were functionally analyzed by transfection of wild-type cells. a clone with a 15-kb fragment of the 63-kb circle was initially found to confer tm resistance. a library of the 15-kb fragment was then prepared and used in toto to transfect wild-type cells. the transfectants that emerge ... | 1992 | 1324414 |
| characterization of sequence changes in kinetoplast dna maxicircles of drug-resistant leishmania. | we have compared kinetoplast dna maxicircles of tunicamycin- and arsenite-resistant variants of repeatedly cloned leishmania mexicana amazonensis showing dna amplification with wild-type and arsenite-resistant variants of the same lineage that do not show dna amplification. dna restriction patterns and the degree of cross-hybridization between maxicircle dna fragments of parasites displaying dna amplification and those of parasites without amplification were examined. in addition, the nucleotide ... | 1992 | 1336569 |
| enhancement of leishmania amazonensis infection in bcg non-responder mice by bcg-antigen specific vaccine. | different patterns of cutaneous leishmaniasis can be induced when a challenge of alike dose of leishmania amazonensis amastigotes in various inbred strains was applied. two strains of mice, the balb/c and c57bl/10j, showed exceptional susceptibility, and 10(6) amastigotes infective dose lead, to ulcerative progressive lesions with cutaneous metastasis and loss by necrosis of leg on which the footpad primary lesion occurred. lesions were also progressive but in a lower degree when c3h/hen and c57 ... | 1992 | 1343799 |
| transkinetoplastidy--a novel phenomenon involving bulk alterations of mitochondrion-kinetoplast dna of a trypanosomatid protozoan. | dramatic and consistent changes of mitochondria or kinetoplast dna (kdna) were observed in certain variants of leishmania amazonensis (a variants) selected in vitro for arsenite-resistance. this was found initially by comparing different lots of wild-type cells and their respective a variants resistant to 30 microm arsenite. the kdnas isolated from these two groups had different restriction patterns and hybridized poorly to each other, whereas those from different lots within each of the two gro ... | 1992 | 1348540 |
| diffuse cutaneous leishmaniasis with atypical aspects. | a 16-year-old man had long-standing diffuse cutaneous leishmaniasis with the following characteristics: diffuse infiltrated lesions rich in amastigotes, absence of mucosal involvement, and lack of parasite-specific cell-mediated immune response. in situ identification of leishmania mexicana amazonensis was achieved by the use of monoclonal antibodies. clinically, as an atypical finding there was deep and extensive ulceration in the lower limbs. histologically, an atypical characteristic was the ... | 1992 | 1428449 |
| biological and chemical studies of pera benensis, a bolivian plant used in folk medicine as a treatment of cutaneous leishmaniasis. | the stem barks of pera benensis are employed by the chimane indians in the bolivian amazonia as treatment of cutaneous leishmaniasis caused by the protozoan leishmania braziliensis. the chloroform extracts containing quinones were found active against the promastigote forms of leishmania and the epimastigote forms of trypanosoma cruzi at 10 micrograms ml-1. the activity guided fractionation of the extract by chromatography afforded active compounds. their structures were elucidated, by spectral ... | 1992 | 1434690 |
| [cloning of kdna minicircles in different species of leishmania and its use as probes for diagnosis]. | the present study describes the cloning procedure for fragments of kinetoplast dna minicircles from different leishmania species and its use for detecting the presence of these parasites. our methodology was as follow: the dna of the kinetoplast from leishmania mexicana amazonensis and leishmania braziliensis panamensis was extracted, purified and digested with the enzyme dra i. these fragments were cloned in the site for hinc ii in the plasmid pks. e. coli was the bacterial strain used for tran ... | 1992 | 1439001 |
| flow cytometry in the study of the interaction between murine macrophages and the protozoan parasite leishmania amazonensis. | a flow cytometry method was adapted to study interaction between murine macrophages and leishmania amazonensis. using this method it was possible to detect internalization of parasites through an increase in macrophage granularity (side scatter), with the latter indicating the presence of parasites inside parasitophorus vacuoles. a quenching technique was used to confirm the feasibility of the method and to distinguish between internalized and externally attached parasites. experiments using fix ... | 1992 | 1445588 |
| synergism in vitro of lovastatin and miconazole as anti-leishmanial agents. | the antifungal drug miconazole and the cholesterol-lowering agent lovastatin (mevinolin) were used in combination to assess their potency as anti-leishmanial agents. the drug combination was synergistic, being more potent in terms of inhibition of promastigote proliferation, macrophage infection and amastigote numbers. in promastigote cultures the effect was more marked in leishmania amazonensis than l. donovani. analysis of the sterol compositions of both promastigote and amastigote cultures re ... | 1992 | 1472085 |
| fibronectin shedding by leishmania may influence the parasite-macrophage interaction. | fibronectin (fn) is a large extracellular matrix protein involved in the endocytosis of several types of particles by different phagocytes. here we investigated the role of fn in the entry and destruction of leishmania amazonensis promastigotes (flagellated form) by murine resident peritoneal macrophages. we also studied the lateral mobility of this protein on the surface of the parasite cells using a immunogold technique. we compared the effects of addition and depletion of fn on infective and ... | 1992 | 1493804 |
| granulocyte-macrophage colony-stimulating factor increases the infectivity of leishmania amazonensis by protecting promastigotes from heat-induced death. | we have studied the effect of granulocyte-macrophage colony-stimulating factor (gm-csf) on the infectivity of promastigotes of leishmania amazonensis, an obligate intramacrophage parasite. we measured the capacity of the promastigotes to infect macrophages after preincubation at different temperatures (28, 34, and 37 degrees c) with recombinant murine gm-csf, as well as the effect of an anti-murine gm-csf antibody on the in vitro and in vivo infectivity of the parasite. gm-csf increases the capa ... | 1992 | 1500159 |
| transfer of zymosan (yeast cell walls) to the parasitophorous vacuoles of macrophages infected with leishmania amazonensis. | leishmania are flagellated protozoan parasites which, in their amastigote stages, survive and multiply within phagolysosome-like parasitophorous vacuoles (pv) of mammalian macrophages (mo). this study develops an earlier ultrastructural, incidental observation that zymosan particles (z) were transferred to the pv of macrophages infected with leishmania amazonensis. in the present report, a pulse-chase light microscopic assay was used to delineate several features of the z transfer. the assay ref ... | 1992 | 1512533 |
| differential production of granulocyte-macrophage colony-stimulating factor by macrophages from mice susceptible and resistant to leishmania mexicana amazonensis. | the present results demonstrate that macrophages from mice susceptible to infection with leishmania mexicana amazonensis sustain a higher production of granulocyte-macrophage colony-stimulating factor (gm-csf) throughout the in vitro infection than macrophages from a resistant strain. resident macrophages from balb/c and c57b1/10 mice were infected with promastigotes of l. mexicana amazonensis and the amount of biologically active gm-csf was measured in the supernatants collected at different ti ... | 1992 | 1541906 |
| loss of the gp46/m-2 surface membrane glycoprotein gene family in the leishmania braziliensis complex. | immunization with the gp46/m-2 membrane glycoprotein of leishmania amazonensis has been shown to induce a protective immune response against infection. we have surveyed a variety of trypanosomatid species and genera for the presence and expression of this gene family, information that will be relevant to future vaccine studies against leishmaniasis. molecular karyotype analysis revealed the presence of gp46/m-2 genes in all members of the leishmania mexicana complex, leishmania major, leishmania ... | 1992 | 1542309 |
| nucleotide sequence of the spliced leader rna gene from leishmania mexicana amazonensis. | 1992 | 1579474 | |
| t-lymphocytes in experimental leishmania amazonensis infection: comparison between immunized and naive balb/c mice. | highly susceptible naive balb/c mice or mice that had previously been immunized i.v. with solubilized homologous antigen (partially resistant) were infected with leishmania amazonensis. histologically, the main differences between the two groups were lymphocytic infiltration and macrophage activation. assays of t-cell function at 3 and 10 weeks after infection revealed that purified t-cells did not proliferate following treatment with leishmania antigen. a mitogenic anti-cd3 monoclonal antibody ... | 1992 | 1584741 |
| extrachromosomal genetic complementation of surface metalloproteinase (gp63)-deficient leishmania increases their binding to macrophages. | a major surface glycoprotein of 63 kda (gp63) has been previously identified biochemically and genetically as a zinc proteinase conserved in pathogenic leishmania spp. the functional significance of this proteinase was analyzed by genetic approaches. a 15-kilobase dna with a tunicamycin-resistance gene from leishmania amazonensis was ligated in two different orientations into pbluescript containing a gp63 gene from leishmania major. these plasmid constructs were used to transfect a variant of l. ... | 1992 | 1594604 |
| tunicamycin-resistant variants from five species of leishmania contain amplified dna in extrachromosomal circles of different sizes with a transcriptionally active homologous region. | twelve independent variants were selected from five species of leishmania for resistance to tunicamycin by exposure of cultured promastigotes to increasing concentrations of this antibiotic, an inhibitor of the microsomal n-acetylglucosamine-1-phosphate transferase in the dolichol pathway of n-glycosylation. all variants obtained from all species, as found previously with leishmania amazonensis, contain amplified chromosomal dna exclusively as extrachromosomal circles. these circular amplicons h ... | 1991 | 1646959 |
| granulocytes in the inflammatory process of balb/c mice infected by leishmania amazonensis. a quantitative approach. | we used previously immunized (partially resistant) and naive (highly susceptible) balb/c mice infected with leishmania amazonensis for evaluating the role of granulocytes in the course of murine leishmaniasis. the animals were examined at different times post-infection and granulocytes counted in lesion tissues examined ultra-structurally. polymorphonuclear granulocytes predominated during the early phase of infection and their number decreased with progression of infection; their number was sim ... | 1991 | 1671620 |
| differentiation and limited proliferation of isolated leishmania mexicana amastigotes at 27 degrees c. | we have demonstrated here that while many amastigotes of both leishmania mexicana amazonensis and leishmania mexicana mexicana differentiate to promastigotes when placed in culture at 27 degrees c, many others remain as amastigotes in their proliferative cycle. we have used this system to examine the effects of the anti-leishmanial compounds amphotericin b, 4-pentenoate and sodium stibogluconate (pentostam) on the proliferation and differentiation of isolated extracellular amastigotes. amphoteri ... | 1991 | 1685870 |
| molecular karyotype and chromosomal localization of genes encoding two major surface glycoproteins, gp63 and gp46/m2, hsp70, and beta-tubulin in cloned strains of several leishmania species. | the molecular karyotypes of several leishmania isolates (leishmania amazonensis, leishmania braziliensis, leishmania guyanensis, leishmania panamensis, leishmania donovani, leishmania major, leishmania aethiopica, leishmania tropica, leishmania enriettii) have been analyzed by clamped homogeneous electric field (chef) gel electrophoresis. the chromosomal localization of genes encoding 2 major surface glycoproteins, gp63 and gp46/m2, heat shock protein 70 (hsp70), and beta-tubulin was determined ... | 1991 | 1779988 |
| cutaneous leishmaniasis due to leishmania (leishmania) amazonensis in amazonian brazil, and the significance of a negative montenegro skin-test in human infections. | the clinical and epidemiological features of 62 cases of cutaneous leishmaniasis due to leishmania (leishmania) amazonensis, from pará state, amazonian brazil, are discussed. the parasite, isolated in hamster skin and/or blood-agar culture medium, was in each case identified by both biological characteristics and a monoclonal antibody specific for promastigotes of l. (l.) amazonensis. of the 62 patients, 46 (74.2%) presented with a single cutaneous lesion, and on no occasion was evidence found i ... | 1991 | 1801340 |
| variations in susceptibility to leishmania amazonensis infection in lines of mice selected for high or low immunoresponsiveness. | the degree of resistance to a local leishmania amazonensis challenge has been compared in lines of mice obtained by selective breeding for high or low immunoresponsiveness: high and low antibody responder mice of selections i and ii (hi, hii and li, lii lines) and high and low responder mice to t mitogen pha (hi/pha and lo/pha). the aim of this preliminary study was to focus attention on genetic differences related with well defined immune characteristics. clear-cut results were obtained, both h ... | 1991 | 1811215 |
| characterization of a membrane antigen of leishmania amazonensis that stimulates human immune responses. | to investigate human immune responses to defined leishmania ag we have begun to characterize biochemically and immunologically, an abundant 42-kda surface ag of leishmania amazonensis, a causative agent of human leishmaniasis. we have shown that this ag, la gp42, is expressed on the surface of l. amazonensis promastigotes, being anchored to the membrane by a glycosyl-phosphatidylinositol moiety. as demonstrated by lectin blotting studies, la gp42 is glycosylated, binding both con a and wheat ger ... | 1991 | 1824776 |
| substrate-dependent ph optima of gp63 purified from seven strains of leishmania. | the major surface glycoprotein of leishmania, gp63, is a membrane-bound metalloprotease. contradictory data supporting a neutral or acidic nature of this enzyme have been presented. seven strains of old and new world leishmania, including leishmania donovani complex (leishmania infantum and l. donovani), leishmania major, leishmania tropica and leishmania mexicana amazonensis were used for the purification and comparative study of gp63. the protein was extracted from promastigotes by phase separ ... | 1991 | 1857388 |
| characterization and classification of leishmanial parasites from humans, wild mammals, and sand flies in the amazon region of brazil. | ninety-four leishmanial isolates from the brazilian amazon region (amapá, amazonas, pará, and rondônia) were identified and classified using specific monoclonal antibodies and an indirect radioimmunoassay (serodeme analysis); eighty-two were also characterized by enzyme electrophoresis (zymodeme analysis), the results of which were subjected to a numerical phenetic analysis. six isolates from humans (3), didelphis marsupialis (1), lutzomyia olmeca nociva (1), and lu, reducta (1) showed reactivit ... | 1991 | 1858968 |
| localization of major histocompatibility complex class ii molecules in phagolysosomes of murine macrophages infected with leishmania amazonensis. | leishmania-infected macrophages are potential antigen-presenting cells for cd4+ t lymphocytes, which recognize parasite antigens bound to major histocompatibility complex class ii molecules (ia). however, the intracellular sites where ia and antigens may interact are far from clear, since parasites grow within the modified lysosomal compartment of the host cell, whereas ia molecules seem to be targeted to endosomes. to address this question, the expression and fate of ia molecules were studied b ... | 1991 | 1900060 |
| stable dna transfection of a wide range of trypanosomatids. | we have shown that the leishmania major transfection vector pr-neo (or derivatives thereof) can be introduced and stably maintained in four species complexes of pathogenic leishmania (l. tropica, l. mexicana, l. donovani, l. braziliensis), and the genera endotrypanum and crithidia; transfection of trypanosoma cruzi or trypanosoma brucei was not successful. quantitative plating assays showed that the transfection efficiencies were high in l. major and leishmania amazonensis (5x10(-5)/cell) and ab ... | 1991 | 1906580 |
| human t cell responses to gp63, a surface antigen of leishmania. | gp63, an abundant and conserved leishmania cell surface protein, has been implicated in the ability of these parasitic protozoa to infect macrophages in vitro and has shown potential as a protective immunogen in mice. however, little is known regarding human immune responses to this glycoprotein ag. in this study, human t lymphocyte responses to leishmania amazonensis native gp63 and to recombinant gp63 (rgp63) produced in escherichia coli were evaluated in individuals with active or cured cutan ... | 1991 | 1940356 |
| leishmania amazonensis: specific labeling of amastigote cysteine proteinases by radioiodinated n-benzyloxycarbonyl-tyrosyl-alanyl diazomethane. | living leishmania amazonensis amastigotes were incubated with radioiodinated n-benzyloxycarbonyl-l-tyrosyl-l-alanyl diazomethane (z-tyr-alachn2), an irreversible inhibitor of mammalian cathepsins b and l. parasite lysates were subjected to electrophoresis in gelatin-containing sodium dodecyl sulfate-acrylamide gels to detect regions of proteolytic activity, and the distribution of the inhibitor was ascertained by autoradiography. of the three main bands of proteolysis associated with cysteine pr ... | 1991 | 1959570 |
| nuclear and cytoplasmic lectin binding sites in promastigotes of leishmania. | we demonstrated the presence of intracellular lectin binding sites in promastigotes of leishmania mexicana amazonensis. direct and indirect lectin-gold techniques were used on lowicryl k4m-embedded cells. the nuclear compartment was labeled by most lectins. nucleoli were mainly labeled by wfh (wistaria floribunda hemagglutinin) and lfa (limax flavus agglutinin) specific for d-galactose/n-acetyl-d-galactosamine (d-gal/d-galnac) and sialic acid, respectively. sections treated with the fetuin-gold ... | 1991 | 2033238 |
| leishmaniasis in bahia, brazil: evidence that leishmania amazonensis produces a wide spectrum of clinical disease. | one hundred fourteen leishmania isolates from patients with different clinical forms of leishmaniasis in the state of bahia, brazil, were characterized by indirect radioimmune binding assay using specific monoclonal antibodies (serodeme analysis). seventy-five of these isolates were also analyzed by enzyme electrophoresis, based on 11 enzyme loci; parasite species were compared, according to their characteristic zymodemes, to those of who leishmania reference strains. all isolates could be class ... | 1991 | 2063957 |
| biochemical characterization of the protective membrane glycoprotein gp46/m-2 of leishmania amazonensis. | biochemical features of the immunologically protective, membrane glycoprotein gp46/m-2 of leishmania amazonensis have been investigated. the protein appears to have a single carbohydrate side chain of approximately 3 kda, representing 7% of the mass of the mature gp46/m-2 protein. experiments removing this carbohydrate side chain from gp46/m-2 indicate that the carbohydrate is not involved in the epitope recognized by the monoclonal antibody, m-2. as this monoclonal antibody recognizes a species ... | 1991 | 1719417 |
| [antiprotozoal effects of benzodiazepine derivatives]. | it is known that some derivatives of the benzodiazepine group act not only as antipsychotic drugs but also have inhibitory effects on the growth of protozoa. the influence of imipramine and its derivatives clomipramine and desipramine on the multiplication of crithidia luciliae, leishmania mexicana amazonensis, trypanosoma cruzi and trichomonas vaginalis was investigated using in vitro cultivation of the parasites and compared with the effects of chlorpromazine and metronidazole. all trypanosoma ... | 1990 | 2085212 |
| granulocyte-macrophage and macrophage colony-stimulating factors activate intramacrophage killing of leishmania mexicana amazonensis. | leishmania organisms are important pathogens, causing diseases worldwide. standard therapies are often toxic and are not always effective. the effect of recombinant human granulocyte-macrophage and macrophage colony-stimulating factors (gm-csf and m-csf) on intramacrophage survival of leishmania mexicana amazonensis (lma) were compared with those of interferon-gamma (ifn-gamma). macrophages previously infected with lma were treated with or without gm-csf and m-csf. compared with no cytokine trea ... | 1990 | 2113077 |
| development of a stable leishmania expression vector and application to the study of parasite surface antigen genes. | trypanosomatid protozoan parasites cause several important tropical diseases and have been a fertile ground for the discovery of molecular paradigms such as trans-splicing and rna editing. transfection-based methods for the study of these organisms have recently been developed, and we have now designed an expression vector, px, which contains only 2.3 kilobases of leishmania dna and can be stably transfected with high efficiency. genes encoding escherichia coli beta-galactosidase or a leishmania ... | 1990 | 2124701 |
| [experimental cutaneous leishmaniasis. iii. histopathological aspects of the developmental behavior of the cutaneous lesion induced in cebus apella (primates: cebidae) by leishmania (viannia) lainsoni, l. (v.) braziliensis and l. (leishmania) amazonensis]. | we have studied the histopathological aspects related to the evolution of cutaneous lesions experimentally produced in the monkey cebus apella (primates: cebidae) by leishmania (v.) lainsoni, l. (v.) braziliensis and l. (l.) amazonensis. microscopical examination of a series of biopsies obtained from these animals showed the kinetics of the cutaneous lesions regarding three species of leishmania inoculated, as follows: 1) an initial non-specific chronic inflammatory infiltrate; 2) macrophagic no ... | 1990 | 2135483 |
| experimental infection with leishmania (viannia) braziliensis and leishmania (leishmania) amazonensis in the marmoset, callithrix penicillata (primates:callithricidae). | fourteen marmosets (callithrix penicillata) were inoculated intradermally with promastigotes and/or amastigotes of leishmania (viannia) braziliensis (l. (v) b.) strains mhom/br/83/ltb-300 mhom/br/85/ltb-12 mhom/br/81/ltb-179 and mhom/br/82/ltb-250. the evolution of subsequent lesions was studied for 15 to 75 weeks post-inoculation (pi). all but 3 of the l. (v) b. injected marmosets developed a cutaneous lesion at the point of inoculation after 3 to 9 weeks, characterized by the appearance of sub ... | 1990 | 2152198 |
| an autochthonous case of cutaneous leishmaniasis caused by leishmania (leishmania) amazonensis lainson & shaw, 1972 from the north of paraná state, brazil. | 1990 | 2152201 | |
| localization and activity of various lysosomal proteases in leishmania amazonensis-infected macrophages. | in mammalian hosts, leishmania amastigotes are obligatory intracellular parasites of macrophages and multiply within parasitophorous vacuoles of phagolysosomal origin. to understand how they escape the harmful strategies developed by macrophages to kill ingested microorganisms, it is important to obtain information on the functional state of parasitophorous vacuole. for this purpose, we studied the intracellular distribution and activity of host lysosomal proteases in rat bone marrow-derived mac ... | 1990 | 2187806 |
| structure-activity relationships of analogs of pentamidine against plasmodium falciparum and leishmania mexicana amazonensis. | the antiprotozoal compound 1,5-di(4-amidinophenoxy)pentane (pentamidine) and 36 of its analogs were screened for in vitro activity against leishmania mexicana amazonensis clone 669 c4s (mhom/br/73/m2269) and plasmodium falciparum clones w2 (indochina iii/cdc) and d6 (sierra leone i/cdc). pentamidine and each of the analogs tested exhibited activity in vitro against l. m. amazonensis and p. falciparum. the pentamidine analogs were more effective against the p. falciparum clones than against l. m. ... | 1990 | 2201254 |
| granulocyte-macrophage colony-stimulating factor is a growth-factor for promastigotes of leishmania mexicana amazonensis. | in this paper we show that murine lung conditioned medium (lcm) displays, in addition to its already described colony-stimulating activity on bone marrow cells, a potent growth-stimulating activity on promastigotes of leishmania mexicana amazonesis. immunoprecipitation of lcm with an antibody specific for murine granulocyte-macrophage colony stimulating factor (gm-csf) abrogates both activities, indicating that the leishmanial growth-promoting activity is due to the presence of gm-csf on lcm. fu ... | 1990 | 2213649 |
| diffuse cutaneous leishmaniasis acquired in peru. | a case of diffuse cutaneous leishmaniasis (dcl) acquired in peru is described. the causative agent was leishmania mexicana amazonensis as determined by isoenzyme analysis and species-specific monoclonal antibody binding characteristics. histological examination of biopsy material showed a large number of intracellular and extracellular amastigotes and few lymphocytes. treatment with meglumine antimoniate (glucantime) administered iv at a dosage of 20 mg antimony/kg body weight/day for 60 days re ... | 1990 | 2221221 |
| intracellular differentiation of leishmania amazonensis promastigotes to amastigotes: presence of megasomes, cysteine proteinase activity and susceptibility to leucine-methyl ester. | intracellular differentiation of leishmania promastigotes to amastigotes is a critical step in the establishment of infection. in this report three related features of mexicana subspecies amastigotes were used to follow the differentiation of the parasites within macrophages. early after infection, (a) parasites did not contain ultrastructurally recognizable megasomes, (b) cysteine proteinase activity of parasite lysates was not detected in gelatin-containing acrylamide gels, and (c) parasites w ... | 1990 | 2235078 |
| molecular cloning and characterization of the immunologically protective surface glycoprotein gp46/m-2 of leishmania amazonensis. | immunization of mice with the gp46/m-2 membrane glycoprotein has been demonstrated to elicit protection against infection with the parasitic protozoan leishmania amazonensis. as this molecule is important for future vaccine studies of leishmaniasis, the gene encoding the gp46/m-2 surface membrane glycoprotein of leishmania amazonensis has been cloned and sequenced. the protein sequence derived from the dna sequence data is consistent with the known biochemical and immunochemical properties of th ... | 1990 | 2236047 |
| experimental cutaneous leishmaniasis by leishmania amazonensis: course of fast-growth infection in the mouse ear. | 1990 | 2251249 | |
| temperature-induced expression of proteins in leishmania mexicana amazonensis. a 22-kda protein is possibly localized in the mitochondrion. | temperature increase is an integral part of leishmania life cycle, and plays a major role in stage transformation. analysis of the temperature-dependent pattern of protein synthesis on two-dimensional gel electrophoresis shows that, in addition to the conserved heat-shock type of response in which expression of the major 70-kda and 83-kda heat-shock proteins is observed, a group of low-molecular-mass (17-40 kda) proteins is induced in promastigotes of leishmania mexicana amazonensis at elevated ... | 1990 | 2269292 |
| sequence analysis and transcriptional activation of heat shock protein 83 of leishmania mexicana amazonensis. | changes in environmental temperature regulate the differential expression of genes during leishmania stage differentiation. therefore, molecular analysis of the heat shock proteins (hsps) in these parasites is of interest as a model for thermoregulation of gene expression. sequences of the hsp83 repetitive unit in the genome of leishmania mexicana amazonensis, including both the coding and intergenic regions, are described. the 5' boundary of the message was mapped by s1 analysis, to potential a ... | 1990 | 2270107 |
| antigenic differences of leishmania amazonensis isolates causing diffuse cutaneous leishmaniasis. | six geographically distinct isolates of leishmania amazonensis causing diffuse cutaneous leishmaniasis (dcl) (from bahia and maranhão, in brazil and guarico, in venezuela) were characterized by immunoblot analysis to see whether any geographical or strain-related differences existed in antigenic composition. western blots of promastigote homogenates were reacted with polyclonal sera from patients infected with l. amazonensis with the various forms of clinical disease. the pattern of antigenic re ... | 1990 | 2278069 |