| leishmania in phlebotomid sandflies. iv. the transmission of leishmania mexicana amazonensis to hamsters by the bite of experimentally infected lutzomyia longipalpis. | | 1977 | 15270 |
| leishmaniasis in brazil: x. some observations of intradermal reactions to different trypanosomatid antigens of patients suffering from cutaneous and mucocutaneous leishmaniasis. | in spite of the difficulty of antigen standardization, paired intradermal skin tests demonstrated qualitative differences between leishmanin and in vitro exo-antigen. some of these differences may be due to the destruction of certain antigens by phenol, while others seem to reflect basic antigenic differences. leishmania mexicana amazonensis in vitro exo-antigen produced immediate anaphylactic reponses in 74.4% of the patients with parasitologically proven cutaneous leishmaniasis. although more ... | 1975 | 52214 |
| leishmania in phlebotomid sandflies. iii. the ultrastructure of leishmania mexicana amazonensis in the midgut and pharynx of lutzomyia longipalpis. | | 1975 | 240164 |
| [new observations upon genital lesions caused by leishmania mexicana amazonensis (author's transl)]. | | 1978 | 575597 |
| the colonization of lutzomyia flaviscutellata (diptera: psychodidae), a vector of leishmania mexicana amazonensis in brazil. | | 1977 | 609078 |
| isolation of the intracellular stages of leishmania mexicana amazonensis using cellulose column. | | 1978 | 736664 |
| [dissemination of leishmania mexicana amazonensis by intracardiac inoculation by pretreatment with gastric mucin (author's transl)]. | | 1978 | 757721 |
| 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 |
| parasitophorous vacuoles of leishmania amazonensis-infected macrophages maintain an acidic ph. | leishmania amastigotes are intracellular protozoan parasites of mononuclear phagocytes which reside within parasitophorous vacuoles of phagolysosomal origin. the ph of these compartments was studied with the aim of elucidating strategies used by these microorganisms to evade the microbicidal mechanisms of their host cells. for this purpose, rat bone marrow-derived macrophages were infected with l. amazonensis amastigotes. intracellular acidic compartments were localized by using the weak base 3- ... | 1990 | 1689700 |
| analyses of surface membrane carbohydrates in parasitic flagellates of the order kinetoplastida using lectins. | crithidia fasciculata, leishmania donovani, leishmania major, leishmania mexicana amazonensis, leishmania tropica, leishmania tarentolae, trypanosoma sp. from formosan bats (tb), trypanosoma lewisi, trypanosoma musculi, and different strains of trypanosoma cruzi (tc) were cultivated at 27 degrees c in a liquid culture medium. flagellates harvested from log phase culture were analyzed for their lectin agglutinating characteristics with concanavalin a (con a), peanut agglutinin, ricinus communis a ... | 1990 | 1696387 |
| the surface free energy of leishmania mexicana amazonensis. | surface charge of leishmania mexicana amazonensis was investigated by direct zeta-potential determination and ultrastructural cytochemistry, and its surface tension was studied by measurements of the advancing contact angle formed by the parasite monolayers with drops of liquids of different polarities. both virulent and avirulent promastigotes exhibited negatively charged surfaces with a zeta-potential of about -15 mv. treatment of these cells with trypsin, alkaline phosphatase, or phospholipas ... | 1990 | 1705480 |
| 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 |
| 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 |
| 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 |
| [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 |
| enhanced intracellular delivery of methotrexate by a receptor-mediated process. | in the present investigation we have described a method of enhancing the uptake of methotrexate by macrophages. this enhanced uptake was mediated by endocytosis through the "scavenger receptor" system which recognized maleylated bovine serum albumin. experimental evidence showed that macrophages internalized methotrexate coupled to maleylated bovine serum albumin through a saturable process at 37 degrees c leading to an eightfold higher concentration of cell-associated methotrexate compared to t ... | 1990 | 2288708 |
| [localization and activity of different lysosomal proteases in rat macrophages infected by leishmania amazonensis]. | leishmania are protozoans of the trypanosomatidae family that cause human infections. the amastigote form of leishmania is an obligate intracellular parasite of mononuclear phagocytes that multiplies within parasitophorous vacuoles (pv) of phagolysosomal origin. to investigate the strategies which allow leishmania to withstand these potentially cytotoxic conditions, the distribution and activities of various lysosomal peptidases in rat macrophages infected or uninfected with leishmania amazonens ... | 1990 | 2290691 |
| protection against leishmania major in balb/c mice by adoptive transfer of a t cell clone recognizing a low molecular weight antigen released by promastigotes. | we have shown previously that balb/c mice can be protected against a fatal infection with leishmania major by adoptive transfer of a t cell line recognizing a protective soluble fraction (fraction 9) of promastigotes. we now describe the isolation and characterization of a t cell clone (9.1-2) that also transfers protective immunity against leishmania. after ag or mitogen stimulation, this clone secrets il-2 and ifn-gamma, but not il-4 or il-5. the clone preferentially recognizes l. major fracti ... | 1990 | 2295814 |
| sequence of the dihydrofolate reductase-thymidylate synthase (dhfr-ts) gene of leishmania amazonensis. | | 1990 | 2339068 |
| the anti-leishmanial activity of dipeptide esters on leishmania amazonensis amastigotes. | l-amino acid esters, such as l-leu-ome, kill leishmania amazonensis amastigotes by a mechanism which appears to involve ester hydrolysis by cysteine proteinases located in the parasite megasomes. we have examined the killing of isolated amastigotes by l-dipeptide esters and derived some structure-activity correlations. toxicity of the compounds for the parasites was measured by a tetrazolium (mtt) reduction assay. the results show that active dipeptide esters contained at least 1 hydrophobic ami ... | 1990 | 2345655 |
| lysosomal depletion in macrophages from spleen and foot lesions of leishmania-infected hamster. | analysis of lysosomes through acid phosphatase cytochemistry at the electron microscopy level has been performed in spleen and foot lesions from leishmania-infected hamsters. the results showed that there is lysosomal depletion in macrophages from leishmania donovani chagasi-infected hamster spleen and similar findings were obtained from foot lesions of leishmania mexicana amazonensis-infected hamsters. the distribution of acid phosphatase and thiamine pyrophosphatase was also examined in the go ... | 1990 | 2373189 |
| structures of the n-linked oligosaccharides of gp63, the major surface glycoprotein, from leishmania mexicana amazonensis. | the extent of protein n-glycosylation in leishmania mexicana amazonensis has been proposed to be a factor in the virulence of the parasite. the n-linked oligosaccharides of gp63, the major surface glycoprotein of l. mexicana amazonensis, were characterized after their release by hydrazinolysis, re-n-acetylation, and reduction with nab3h4. high voltage paper electrophoresis of the reduced oligosaccharides revealed only neutral species. gel-permeation chromatography on bio-gel p-4 yielded four fra ... | 1990 | 2373691 |
| activity of ketoconazole derivatives against leishmania mexicana amazonensis within mouse peritoneal macrophages. | imidazoles such as ketoconazole have proven antileishmanial activity, both in vitro and in vivo. new derivatives of ketoconazole have been synthesized in order to improve the therapeutic index and antileishmanial activity as assessed by mouse peritoneal macrophages infected with leishmania mexicana amazonesis. amino-acid derivatives of ketoconazole are at least 10 times more effective than ketoconazole in vitro, and the best effect is observed using the phenylalanyl-ketoconazole. fatty acid deri ... | 1990 | 2383093 |
| inhibition of leishmanias but not host macrophages by the antitubulin herbicide trifluralin. | the dinitroaniline herbicide trifluralin (alpha, alpha, alpha-trifluoro-2,6-dinitro-n, n-dipropyl-p-toluidine), at micromolar concentrations, selectively inhibited both proliferation and differentiation of the parasitic protozoan leishmania mexicana amazonensis. in vitro, radioactive trifluralin showed specific binding to leishmania tubulin but not to mammalian tubulin. because herbicides such as trifluralin are economical and are considered safe for man and domesticated animals, they may serve ... | 1990 | 2392684 |
| conserved sequences in the u2 snrna-encoding genes of kinetoplastida do not include the putative branchpoint recognition region. | the u2 small nuclear rna (snrna) of trypanosoma brucei gambiense, a flagellated protozoon of the order kinetoplastida, is 148 nucleotides (nt) long, and thus the smallest u2 snrna identified so far. to examine the evolutionary conservation of this rna among kinetoplastida, we have cloned and sequenced the u2 genes from trypanosoma congolense and leishmania mexicana amazonensis, which are 145 and 141 nt in length, respectively. the sequences of the kinetoplastida u2 snrnas are essentially identic ... | 1990 | 2401409 |
| specific immunization of mice against leishmania mexicana amazonensis using solubilized promastigotes. | successful immunization of highly susceptible balb/c mice against progressive infection by leishmania mexicana amazonensis, using whole solubilized promastigotes was achieved. the best immunization schedule consisted of three weekly injections of 5 x 10(7) parasite equivalents. intravenous was superior to intraperitoneal or subcutaneous immunization. protection persisted for up to 2 months after immunization, and beneficial effects could be observed in long-term follow-up (24 weeks after infecti ... | 1987 | 2441913 |
| monoclonal antibodies specific for the amastigote stage of leishmania pifanoi. i. characterization of antigens associated with stage- and species-specific determinants. | eight mab were produced against membrane-enriched preparations of leishmania pifanoi amastigotes either grown in axenic culture (p-1 through p-6) or isolated from macrophage cell culture (p-7 and p-8). two mab produced against promastigote membranes (p-9 and p-10) were found to be specific against this stage. antibodies p-1 through p-8 on analysis by radioimmune binding only reacted with determinants present on amastigotes. mab p-2, p-4, and p-8 also reacted with leishmania amazonensis amastigot ... | 1988 | 2450920 |
| [sensitivity of the culture of circulating leukocytes in the detection of leishmania in the peripheral blood of patients with tegumentary leishmaniasis]. | the possible presence of leishmania in the peripheral blood of 60 patients with american cutaneous leishmaniasis was investigated by the culture of circulating leucocytes. patients were selected with a variety of clinical forms of the disease and in different evolutionary stages of infection. biopsies of skin and/or mucosal lesions were made in order to isolate the parasites, which were identified using monoclonal antibodies. 40 isolations were obtained, including 5 of leishmania (viannia) brazi ... | 1989 | 2486526 |
| in situ identification of leishmania amazonensis associated with diffuse cutaneous leishmaniasis in bahia, brazil. | | 1989 | 2487456 |
| biochemistry of pentostam resistant leishmania. | promastigotes of leishmania mexicana amazonensis wr 669 clone 4 were made resistant to antimony in the form of pentostam (sodium stibogluconate) by exposure to media containing increasing concentrations of sb. the dose of sb expected to kill 50% of promastigotes and amastigotes of the parent sensitive clone (wr 669) and the resistant clone (wr 669r) was determined by exposure of suspensions in physiologic salt solution for 3 hr. the approximate ed50s in microgram sb/ml were: 10,000 for wr 669r p ... | 1989 | 2537584 |
| the effect of pentostam and cimetidine on the development of leishmaniasis (leishmania mexicana amazonensis) and concomitant malaria (plasmodium yoelii). | balb/c mice were infected with leishmania mexicana amazonensis and/or plasmodium yoelii in order to determine the impact of multiple parasitic infection on the efficacy of chemotherapeutic agents. uninfected, p. yoelii-infected, l.m. amazonensis-infected, and l.m. amazonensis and p. yoelii-infected mice were inoculated with cimetidine (80 mg kg-1 day-1) or pentostam (200 mg kg-1 day-1) once a day for an initial 20-day period, and once a week thereafter. leishmania mexicana amazonensis lesion dev ... | 1989 | 2557804 |
| anionic site behavior in leishmania and its role in the parasite-macrophage interaction. | the behavior of cationized ferritin (cf) binding sites on the surface of leishmania mexicana amazonensis (amastigotes, infective and non-infective promastigotes) and their participation in the interaction with macrophages were evaluated. glutaral-dehyde-fixed parasites treated with cf present a uniform labelling over the whole cell surface. however, living parasites displayed cf patches and caps. capping was usually seen towards the anterior (flagellated) portion of the cells, where shedding phe ... | 1989 | 2606939 |
| antileishmanial effects of clofazimine and other antimycobacterial agents. | in the search for more effective alternatives to the presently-used antileishmanial drugs, the activity of the major groups of antimycobacterial compounds has been examined, both in vitro and in animal models of infection. in vitro, clofazimine was the most active compound tested, with a mean ed50 of 2.3 mg l-1 against leishmania mexicana amazonensis, 1.4 mg l-1 against l. donovani and 0.5 mg l-1 against l. major. other active compounds were the thiosemicarbazone, thiambutosine, and salinazid, a ... | 1989 | 2619361 |
| studies on trypanosomatid actin. i. immunochemical and biochemical identification. | in this study, the presence of actin in cultured trypanosomatids was investigated using polyclonal antibodies to heterologous actin. polyclonal antisera to rabbit muscle actin and a monospecific anti-actin antibody react with a 43-kda polypeptide in extracts of trypanosoma cruzi, herpetomonas samuelpessoai and leishmania mexicana amazonensis on protein immunoblots. the 43-kda polypeptide co-migrates with skeletal muscle actin and is retained within trypanosomatid cytoskeletons. attempts to isola ... | 1989 | 2651660 |
| immunotherapy of localized, intermediate, and diffuse forms of american cutaneous leishmaniasis. | the clinical efficacy of immunotherapy for localized american cutaneous leishmaniasis with a combination of heat-killed leishmania mexicana amazonensis promastigotes and viable bcg (bacille calmette guérin) has been compared with meglumine antimoniate chemotherapy and with bcg alone in a controlled clinical study in 217 patients. the results in the first two groups were comparable, with greater than 90% clinical cures with an average time of 16-18 w required for healing. the cure rate was consid ... | 1989 | 2659679 |
| amastigote stage-specific monoclonal antibodies against leishmania major. | monoclonal antibodies were produced against gamma-irradiated amastigotes of leishmania major. five antibodies (t16 through t20) were selected which reacted in enzyme-linked immunoassays with the intracellular stage of the parasite. these antibodies did not react with promastigotes of l. major or leishmania donovani. one of the monoclonal antibodies (t16) reacted with amastigotes of leishmania mexicana amazonensis and l. donovani. western blotting (immunoblotting) and immunoprecipitation of [35s] ... | 1989 | 2680982 |
| heat-shock protein 83 of leishmania mexicana amazonensis is an abundant cytoplasmic protein with a tandemly repeated genomic arrangement. | the 83-kda heat-shock protein hsp83 is a highly abundant protein in leishmania amastigotes and promastigotes exposed to elevated temperature. antibodies against this protein were obtained by immunization with a synthetic peptide derived from a conserved region. these antibodies recognized both the denatured and the native form of the molecule and were used for immunofluorescence analysis. these experiments, together with analysis by cell fractionation, show that hsp83 is distributed in the cytop ... | 1989 | 2684665 |
| receptor-mediated drug delivery to macrophages in chemotherapy of leishmaniasis. | methotrexate coupled to maleylated bovine serum albumin was taken up efficiently through the "scavenger" receptors present on macrophages and led to selective killing of intracellular leishmania mexicana amazonensis amastigotes in cultured hamster peritoneal macrophages. the drug conjugate was nearly 100 times as effective as free methotrexate in eliminating the intracellular parasites. furthermore, in a model of experimental cutaneous leishmaniasis in hamsters, the drug conjugate brought about ... | 1989 | 2717947 |
| leishmania amazonensis: involvement of cysteine proteinases in the killing of isolated amastigotes by l-leucine methyl ester. | l-leucine-methyl ester (leu-ome) kills leishmania mexicana amazonensis amastigotes by a mechanism which requires proteolytic cleavage of the ester. n-benzyloxycarbonyl-phenylalanyl-alanyl diazomethane (z-phe-alachn2), a specific and irreversible inhibitor of cysteine proteinases, was used to characterize the enzymes involved in parasite destruction. it was shown that (1) amastigotes preincubated with micromolar concentrations of z-phe-alachn2 survived challenge with leu-ome concentrations lethal ... | 1989 | 2721634 |
| development of metacyclic leishmania promastigotes is associated with the increasing expression of gp65, the major surface antigen. | using immunofluorescence techniques and flow microfluorometry analysis, we have demonstrated that the binding of a monoclonal antibody (vd5/25) produced against gp65, the major surface antigen of leishmania braziliensis, increased on the surface of stationary-phase promastigotes from all the new world leishmania species causing mucocutaneous or cutaneous disease as compared with the log-phase parasites. in addition, a sequential development of leishmania amazonensis promastigotes from a non-infe ... | 1989 | 2771426 |
| in vitro and in vivo effects of interleukin 2 on the protozoan parasite leishmania. | t cells can have either resistance-promoting or disease-promoting effects in murine cutaneous leishmaniasis. it is known that the adoptive transfer of parasite-specific helper t cells led to an exacerbation of leishmania-induced lesions. this work presents evidence that lymphokines produced by activated t cells could be involved in this exacerbating process by directly stimulating the parasite growth. in the presence of activated t cell supernatants, the in vitro growth of leishmania mexicana am ... | 1989 | 2785043 |
| megasomes as the targets of leucine methyl ester in leishmania amazonensis amastigotes. | certain l-amino acid esters, such as l-leucine methyl ester (leu-ome), can kill intracellular and isolated leishmania amazonensis amastigotes. killing appears to involve ester trapping and hydrolysis within an acidified parasite compartment (m. rabinovitch and s. c. alfieri, 1987, brazilian journal of medical and biological research 20, 665-74). we show here by acid phosphatase light microscopic cytochemistry and by ultrastructural morphometry that megasomes, lysosome-like amastigote organelles, ... | 1989 | 2797865 |
| leishmania mexicana: a cytochemical and quantitative study of lysosomal enzymes in infected rat bone marrow-derived macrophages. | the cellular localization and activity of the lysosomal enzymes acid phosphatase, trimetaphosphatase, and arylsulfatase were studied in rat bone marrow-derived macrophages infected with leishmania mexicana amazonensis amastigotes. the specific activity of acid phosphatase normalized for protein content was similar in normal macrophages and in isolated amastigotes, whereas the latter were markedly deficient in trimetaphosphatase and arylsulfatase activities. it is thus likely that trimetaphosphat ... | 1987 | 2824235 |
| n-glycosylation as a biochemical basis for virulence in leishmania mexicana amazonensis. | promastigotes of leishmania mexicana amazonensis grown in vitro under different conditions showed variable degrees of virulence, as determined quantitatively by the size of the lesions and the number of intracellular parasites produced in mice and in cultured macrophages, respectively. promastigotes newly transformed from amastigotes gave the highest degree of virulence, which decreased progressively with periods of their continuous in vitro cultivation. this loss of virulence was prevented by m ... | 1988 | 2830512 |
| inhibition of leishmanial protein kinase by antileishmanial drugs. | protein kinase was isolated from both amastigotes and promastigotes of leishmania mexicana amazonensis. unlike the previously described enzyme from l. donovani promastigotes, activity of the l. mexicana kinases was 2-3 times higher at low ionic strength than at high ionic strength, and was 3-10-fold augmented by removal of endogenous low molecular weight inhibitors. the km of the l. mexicana kinases was 123-223 microm, compared to the value of 70 microm for the beef heart kinase. purine nucleosi ... | 1988 | 2833126 |
| inhibition of growth of leishmania mexicana mexicana by leishmania mexicana amazonensis during "in vitro" co-cultivation. | inhibition of one leishmania subspecies by exometabolites of another subspecies, a phenomenon not previously reported, is suggested by our recent observations in cell cloning experiments with leishmania mexicana mexicana and leishmania mexicana amazonensis. clones were identified using the technique of schizodeme analysis. the phenomenon observed is clearly relevant to studies of parasite isolation, leishmanial metabolism, cross-immunity and chemotherapy. | 1987 | 2853814 |
| leishmania mexicana amazonensis: heterogeneity in 5'-nucleotidase and peroxidase activities of mononuclear phagocytes during in vivo and in vitro infection. | the degree of maturation of cells of the mononuclear phagocyte system (mps), during in vivo and in vitro infection by leishmania mexicana amazonensis, was evaluated in this study. the macrophages' differentiation was assayed by cytochemical characterization at the ultrastructural level, using two well-established markers: 5'-nucleotidase enzyme activity, for revealing the mature cells; and the peroxidase activity present in the cell granules to demonstrate immature mononuclear phagocytes. only a ... | 1988 | 2854875 |
| different patterns of disease in two inbred mouse strains infected with a clone of leishmania mexicana amazonensis. | we have infected balb/c and c57bl/6 mice with a cloned leishmania mexicana amazonensis population, obtained from the "maria" strain. progression of infection and histopathological examination confirmed the extreme susceptibility of balb/c mice and the resistant pattern of the c57 bl/6. anti-leishmania antibody titers were higher in balb/c than in c57bl/6 mice through the period of infection. tests of delayed type hypersensitivity reaction with leishmania antigens were positive in both strains in ... | 1987 | 2884839 |
| immune serum from both susceptible and resistant strains of mice increases phagocytosis of leishmania mexicana amazonensis by macrophages. | immune sera obtained from either balb/c mice (susceptible) at 7 weeks, or c57bl/6 mice (resistant), at 7 weeks after infection with l. m. amazonensis, were effective in increasing internalization of homologous promastigotes into starch-induced peritoneal macrophages (from both mouse strains). both the internalization enhancing effect and the levels of anti-leishmanial antibody (elisa) were removed from sera by absorption with heat-killed promastigotes. sera at 1/200 dilution obtained from either ... | 1987 | 2892370 |
| dna amplification in arsenite-resistant leishmania. | arsenite-resistant variants of a trypanosomatid protozoan, leishmania mexicana amazonensis, were selected in vitro by stepwise increases of sodium arsenite concentrations up to 30 microm in the culture medium. these variants were found to contain amplified dna as extrachromosomal supercoiled molecules of about 69 kb. they originate from a single chromosome in the wild-type cells. there is evidence of chromosomal changes in these cells associated with the selection for arsenite resistance. the ap ... | 1989 | 2909386 |
| identification, using isoenzyme electrophoresis and monoclonal antibodies, of leishmania isolated from humans and wild animals of ecuador. | six strains of leishmania isolated from wild mammals and humans on the pacific coast of ecuador were identified by isoenzyme electrophoresis and by their reactivity patterns to a cross-panel of specific monoclonal antibodies using a radioimmune binding assay. single isolates from sciurus vulgaris, potos flavus, and tamandua tetradactyla were identified as leishmania amazonensis. three other strains, isolated from cutaneous lesions of humans, were identified as leishmania panamensis. | 1989 | 2919726 |