| hemagglutination of neuraminidase-treated human erythrocytes by leishmania enriettii infected guinea-pig sera. | sera from guinea-pigs infected with the protozoan parasite leishmania enriettii showed higher hemagglutination (ha) titres for neuraminidase treated human erythrocytes than those of normal guinea-pig sera. this ha activity was associated mostly with the 19s fraction of the immune serum and could be absorbed out with an antigenic fraction of the parasite membrane. antigenic determinants involved in this ha reaction consisted of, at least, beta-d-galactosyl or lactosyl residues. | 1976 | 60254 |
| effect of sodium stibogluconate on infections of leishmania enriettii, with observations on the interaction of drug and immune response. | | 1977 | 192159 |
| conversion of dihydroorotate to orotate in parasitic protozoa. | the conversion of dihydroorotate to orotate, one of the key reactions in the de novo pyrimidine biosynthetic pathway, has been studied in a number of parasitic protozoa. enzyme activities capable of carrying out this reaction were detected in six members of the kinetoplastida (trypanosoma brucei, trypanosoma congolense, trypanosoma vivax, trypanosoma lewisi, trypanosoma cruzi, leishmania enriettii) and three members of the genus plasmodium (p. knowlesi, p. berghei, p. gallinaceum). the mechanism ... | 1979 | 217438 |
| studies on the mechanisms of macrophage activation. i. destruction of intracellular leishmania enriettii in macrophages activated by cocultivation with stimulated lymphocytes. | when cultures of normal mouse peritoneal macrophages were infected with the intracellular protozoan parasite leishmania enrietti, the micro-organism was found to survive intracellularly for several days, apparently without multiplication. however, exposure of infected macrophages to certain stimuli led to rapid parasite killing and digestion, providing a sensitive assay with which the mechanisms of macrophage activation can be studied. microbicidal activity was induced by incubation of macrophag ... | 1978 | 308979 |
| studies on the mechanisms of macrophage activation. ii. parasite destruction in macrophages activated by supernates from concanavalin a-stimulated lymphocytes. | activation of mouse peritoneal exudate macrophages, as evidenced by destruction of the intracellular protozoan parasite leishmania enriettii, was obtained by incubation with supernates from concanavalin a (con a)-stimulated syngeneic spleen cells. parasites were not destroyed in macrophages exposed to control media. supernate-induced activation was independent of the presence of con a. the activating principle (macrophage activating factor, or maf) was produced by con a-stimulated lymphocytes in ... | 1979 | 458379 |
| the quantification of viable leishmania enriettii from infected guinea-pig tissues. | results are presented demonstrating that in vitro cultivation of leishmania enrietti can be used to determine the level of viability in suspensions of l. enrietti used for infection and also to quantify the number of viable organisms in infected tissues. | 1979 | 466861 |
| intracellular behaviour of leishmania enriettii within murine macrophages. | both promastigotes and amastigotes of leishmania enriettii were readily ingested by mouse peritoneal macrophages (mpm). promastigotes after their entry within mpm were rapidly immobilized and their multiplication was never observed. microscopic examination revealed that ingested promastigotes were degraded with mpm. nonmotile amastigotes of l. enriettii taken up by mpm, on the other hand, multiplied intracellularly and eventually destroyed the infected cells. | 1978 | 658235 |
| influence of rodent malaria on the course of leishmania enriettii infection of hamsters. | plasmodium yoelii infection was established in hamsters, and the effect of this type of malaria on concurrent leishmania enriettii infection was examined. it was found that the course of the l. enriettii infection was affected by p. yoelii and that this effect depended on the relative timing of the two infections. a chronic malarial infection with plasmodium berghei was also established in hamsters, and this was found to affect the course of a concurrent l. enriettii infection in a similar manne ... | 1976 | 786886 |
| mechanisms of protective immunity in experimental cutaneous leishmaniasis of the guinea-pig. i. lack of effects of immune lymphocytes and of activated macrophages. | leishmania enriettii is an obligatory intracellular protozoan parasite which infects guinea-pigs and resides in macrophages. subcutaneous inoculation produces a skin infection which heals spontaneously and leaves the animal immune to reinfection. experiments have been performed to explore the mechanisms of parasite destruction in the recovering and immune animal. using quantitative techniques to assess parasite survival it was found that l. enriettii is not killed in vitro in macrophages from im ... | 1975 | 813928 |
| antigenic components of the protozoan parasite leishmania enriettii inducing humoral and cell-mediated immune responses in infected guinea-pig. | | 1977 | 881221 |
| promotion of leishmanial infections in non-permissive host macrophages by conditioned medium. | leishmania enriettii grows well in guinea pig macrophages in culture but fails to do so in mouse macrophages. dialyzed and concentrated conditioned medium from l. enriettii cultures promoted the infection in the mouse macrophages at 37 degrees c and at 32 degrees c. similarly processed medium on which l. tropica had been cultured did not cause the same effect. immune precipitation of the conditioned medium by anti-leishmania serum cancelled out the effect. infections of guinea pig macrophages by ... | 1977 | 919693 |
| modification of cutaneous leishmaniasis in the guinea-pig by cyclophosphamide. | pretreatment of guinea-pigs with cyclophosphamide (cy) (300 mg/kg) 3 days before cutaneous infection with leishmania enriettii caused an increased intensity of the lesion at the site of infection and an increase in the incidence of widespread metastases. decreased levels of circulating antibody were found from the first to fourth week after infection. decreased delayed type hypersensitivity could only be detected beyond 4 weeks. peritoneal macrophages obtained form guinea-pigs 3 days after cy pr ... | 1976 | 949870 |
| anti-leishmania activity of normal animal sera. | the growth inhibition activity of normal human, dog, rabbit, guinea pig, rat, sheep, cat, mouse and chicken sera was quantified against leishmania enriettii and leishmania tropica. the pattern of anti-l. enriettii activity of various animal sera was somewhat different from that observed in l. tropica. against l. enriettii, mouse serum was inactive, and against l. tropica rat and mouse sera were inactive. all the other animal sera tested had growth inhibition activity on both leishmanias. this gr ... | 1975 | 1124967 |
| mucocutaneous leishmaniasis in guinea-pigs inoculated intravenously with leishmania enriettii. preliminary report. | seven guinea-pigs were inoculated intravenously with a rich suspension of leishmania enriettii. during the sixth to the seventh week from inoculation, all of them developed lesions within the anterior nasal mucosa and in the vulva or scrotum. in one animal nodules occurred in the forepaws during the tenth week. the histology of the latter showed an epithelioid granuloma with multinucleate giant cells, while in all the others macrophages and monocytes highly parasitized with leishmania bodies, fo ... | 1975 | 1182080 |
| the fine structure of leishmania enriettii in the guinea pig. | | 1975 | 1201899 |
| the montenegro reaction in guinea pigs infected by leishmania enriettii and the effect of antigens prepared from various leishmania isolates. | all antigens (leishmanin) prepared from nine isolates of leishmania gave positive skin tests in guinea pigs infected with l. enriettii. however, variation in potency was observed and ascribed to batch variation. it is recommended that biological testing of leishmanin is considered before use in field surveys or as an aid to clinical diagnosis. | 1976 | 1271510 |
| establishment of cutaneous leishmania enriettii infection in hamsters. | a model of a self-healing type of cutaneous leishmaniasis was established in hamsters using the guinea pig parasite leishmania enriettii. l. enriettii was passaged several times in hamsters without losing its infectivity for guinea pigs or for hamsters. the course of the infection in hamsters resembled that of guinea pigs, with the exception that the lesion at the site of parasite inoculation did not ulcerate and no metastatic lesions developed spontaneously. moreover, unlike guinea pigs, infect ... | 1976 | 1279005 |
| enhancement of murine macrophage binding of and response to bacterial lipopolysaccharide (lps) by lps-binding protein. | we have studied the effects of highly purified rabbit lipopolysaccharide (lps)-binding protein (lbp) on the ability of murine bone marrow-derived macrophages to respond to bacterial lps. macrophage responses studied include the secretion of tumor necrosis factor alpha, production of arginine-derived nitrite (no2-), and killing of an intracellular pathogen, leishmania enriettii. macrophages from either cba or lps-hyporesponsive c3h/hej mice exhibited significantly greater sensitivity to lps in th ... | 1992 | 1402386 |
| creation of null/+ mutants of the alpha-tubulin gene in leishmania enriettii by gene cluster deletion. | tubulins are abundant structural proteins in the leishmania parasite, and tubulin genes are examples of highly expressed genes, which are present in multiple copies arranged in tandem repeats. functional analysis of such multicopy genes using genetic manipulation has not yet been possible. here we describe a method for creating deletions of alpha-tubulin gene clusters by targeted gene replacement and report the isolation of null/+ mutants deleted for either of the two allelic tubulin clusters. w ... | 1992 | 1429722 |
| a sequence insertion targeting vector for leishmania enriettii. | we have demonstrated previously that leishmania enriettii contains the enzymatic machinery to mediate efficient interplasmidic homologous recombination. in this report we show that a sequence insertion targeting vector, palt-neo-tub, can be inserted into the genome of l. enriettii by homologous recombination between alpha-tubulin sequences found in the plasmid and their homologs in the genome. palt-neo-tub, a pbluescript-derived vector containing the neor gene flanked by the alpha-tubulin interg ... | 1992 | 1537857 |
| gene expression in leishmania: analysis of essential 5' dna sequences. | a major unanswered question in kinetoplastida parasites is the mechanism of regulating gene expression. using a transfection system, we have previously shown that the intergenic region of the alpha-tubulin gene of leishmania enriettii contained sequences required for gene expression. the goal of the work reported here was to determine whether the leishmania-derived sequences were providing transcriptional control signals or functioning at a post-transcriptional level, most likely in trans-splici ... | 1992 | 1557376 |
| a potential hexose transporter gene expressed predominantly in the bloodstream form of trypanosoma brucei. | a cdna cloned from trypanosoma brucei brucei codes for a putative membrane protein which is homologous to the erythrocyte glucose transporter and several other sugar transporters from escherichia coli, yeast, algae and leishmania. this cdna hybridizes to a 2.3-kb mrna that accumulates to a much higher degree in the bloodstream mammalian form than in the procyclic insect form of the parasite. the correlation between the expression of this gene and the hexose metabolism of leishmania enriettii and ... | 1992 | 1625698 |
| effect of rna secondary structure and modified bases on the inhibition of trypanosomatid protein synthesis in cell free extracts by antisense oligodeoxynucleotides. | every messenger rna from leishmanias and trypanosomes has at its 5' end a conserved region termed the mini-exon sequence which, however, varies from species to species. in a systematic study mrnas from trypanosoma brucei, trypanosoma vivax, and leishmania enriettii were translated in cell-free extracts in the presence of oligodeoxynucleotides complementary to part of the mini-exon sequence. the affinity of the same oligonucleotides for target and non-target mrnas was determined by thermal elutio ... | 1990 | 1697674 |
| structural isoforms of a membrane transport protein from leishmania enriettii. | a membrane transport protein of the glucose transporter superfamily from leishmania enriettii is encoded by a family of tandemly repeated genes. the first gene in this tandem repeat codes for a structural isoform that contains a unique amino-terminal hydrophilic domain, probably located in the cytoplasm; the remainder of the protein is identical to the polypeptide encoded by the internal genes in the tandem repeat. the unique isoform is represented by a distinct stable rna. | 1990 | 1701025 |
| 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 |
| macrophage activation for intracellular killing as induced by calcium ionophore. correlation with biologic and biochemical events. | changes in the concentration of cytosolic ca2+ are known to affect various macrophage functions; in particular, exposure in vitro to the ca2+ ionophore a23187 primes macrophages for tumor cell killing. in the present report, it is shown that treatment with this ionophore similarly mimics ifn-gamma as a priming signal for induction of microbicidal activity. incubation of mouse bone marrow-derived macrophages with 10(-7) to 10(-6) m a23187 (in the presence of ca2+) led to intracellular killing of ... | 1991 | 1898600 |
| phagocytosis enhances murine macrophage activation by interferon-gamma and tumor necrosis factor-alpha. | previously, we reported that exposure of bone marrow-derived macrophages (m phi) to a phagocytic stimulus in the simultaneous presence of interferon-gamma (ifn-gamma) induced these cells to generate nitrite (no2-). this effect was achieved using both living (i.e. promastigotes of the protozoan parasite leishmania enriettii) and inert (latex beads) particles. when the phagocytic stimulus was leishmania, enhanced intracellular killing accompanied elevated no2- secretion. as shown here, the capacit ... | 1991 | 1915557 |
| 18s rrna sequences of leishmania enriettii promastigote and amastigote. | dideoxy sequencing with reverse transcriptase and universal primers was used to obtain partial sequences of the 18s rrnas from the promastigote and amastigote life-cycle stages of l. enriettii. approximately 1400 nucleotides of sequence from the two stages were compared. unlike plasmodium berghei, in which 18s rrnas from the mosquito stage and the mammalian stage of the life cycle are only 96.5% similar, the amastigote and promastigote rrnas of l. enriettii are identical. in addition, a comparis ... | 1991 | 1917290 |
| structure and regulation of histone h2b mrnas from leishmania enriettii. | we have studied the structure and expression of histone h2b mrna and genes in the parasitic protozoan leishmania enrietti. a genomic clone containing three tandemly repeated genes has been sequenced and shown to encode three identical histone proteins and two types of closely related mrna sequence. we have also sequenced three independent cdna clones and demonstrated that the leishmania h2b mrnas are polyadenylated, similar to the basal histone mrnas of higher eucaryotes and the histone mrnas of ... | 1991 | 1986223 |
| homologous recombination in leishmania enriettii. | we have used derivatives of the recently developed stable transfection vector palt-neo to formally demonstrate that leishmania enriettii contains the enzymatic machinery necessary for homologous recombination. this observation has implications for gene regulation, gene amplification, genetic diversity, and the maintenance of tandemly repeated gene families in the leishmania genome as well as in closely related organisms, including trypanosoma brucei. two plasmids containing nonoverlapping deleti ... | 1991 | 1992478 |
| metabolic and functional stimulation of lymphocytes and macrophages by an escherichia coli extract (om-89): in vitro studies. | om-89, a proteinaceous extract from escherichia coli with very low endotoxin content, was tested for its capacity to stimulate in vitro cells involved in the immune response. om-89 induced a marked proliferation of mouse spleen cells; e. coli lipopolysaccharide (lps) at the same concentration as present in om-89 was totally ineffective. passage through nylon wool strongly decreased the om-89-induced effect, suggesting that the responding lymphocytes were of the b lineage. exposure of bone marrow ... | 1990 | 2160522 |
| stable expression of the bacterial neor gene in leishmania enriettii. | molecular genetic studies in parasitic protozoa have been hindered by the lack of methods for the introduction and expression of modified or foreign genes in these organisms. two recent reports described the transient expression of the bacterial chloramphenicol acetyl transferase (cat) gene under the control of parasite-specific sequences. we now describe the stable expression of a selectable marker, the gene for neomycin resistance (neor) in leishmania enriettii. a chimaeric gene containing the ... | 1990 | 2300209 |
| developmentally regulated transporter in leishmania is encoded by a family of clustered genes. | we have previously cloned a gene for a developmentally regulated transport protein from the trypanosomatid protozoan leishmania enriettii. we demonstrate here that this transporter is encoded by a single family of tandemly clustered genes containing approximately 8 copies of the 3.6 kilobase repeat unit. transcriptional mapping defines a contiguous 3.3 kilobase region of the repeat unit that encodes the mrna. the 5' end of the mature mrna contains the spliced leader or mini-exon previously ident ... | 1990 | 2326193 |
| cloning and characterization of a leishmania gene encoding a rna spliced leader sequence. | recent studies on leishmania enriettii tubulin mrnas revealed a 35 nucleotide addition to their 5' end. the gene that codes for this 35 nucleotide leader sequence has now been cloned and sequenced. in the leishmania genome, the spliced leader gene exists as a tandem repeat of 438 bases. there are approximately 150 copies of this gene comprising 0.1% of the parasite genome. this gene codes for a 85 nucleotide transcript that contains the spliced leader at its 5' end. the 35 nucleotide sequence an ... | 1986 | 2429261 |
| lead inhibits intracellular killing of leishmania parasites and extracellular cytolysis of target cells by macrophages exposed to macrophage activating factor. | activation of leishmania enriettii-infected mouse macrophages in vitro by treatment with macrophage activating factor (maf)-rich media supplemented with lipopolysaccharide (lps) leads to rapid killing of the microorganism. when exposed to maf + lps in the presence of 30-100 microm lead acetate, however, macrophages failed to destroy the parasites. this effect was not due to lead toxicity for macrophages. decreased microbicidal activity correlated with depressed respiratory burst as determined by ... | 1989 | 2496192 |
| stimulation by a bacterial extract (broncho-vaxom) of the metabolic and functional activities of murine macrophages. | peritoneal and bone marrow-derived macrophages of the c57bl/6 and dba/2 mouse strains were exposed in vitro to increasing concentrations of the bacterial lysate broncho-vaxom (bv), in the presence or absence of macrophage-activating factor (maf)-rich media. two metabolic pathways and two functional activities of the macrophages were studied. first, oxidative metabolism was found to increase sharply in macrophages incubated with bv, as measured by the catabolism of glucose via the hexose monophos ... | 1989 | 2553625 |
| transfection of leishmania enriettii and expression of chloramphenicol acetyltransferase gene. | we report a transient expression transfection system in leishmania enriettii. a hybrid gene containing an intergenic region of the alpha-tubulin cluster and the bacterial chloramphenicol acetyltransferase (cat; ec 2.3.1.28) gene is expressed after transfection of l. enriettii with the hybrid plasmid. the expression of the cat gene is dependent on the presence of sequences from the alpha-tubulin gene. the hybrid gene is also active in leishmania braziliensis and leishmania major. | 1989 | 2594753 |
| macrophage activation by the polysaccharide arabinogalactan isolated from plant cell cultures of echinacea purpurea. | in this study, acidic arabinogalactan, a highly purified polysaccharide from plant cell cultures of echinacea purpurea, with a molecular weight of 75,000, was effective in activating macrophages to cytotoxicity against tumor cells and micro-organisms (leishmania enriettii). furthermore, this polysaccharide induced macrophages to produce tumor necrosis factor (tnf-alpha), interleukin-1 (il-1), and interferon-beta 2. arabinogalactan did not activate b cells and did not induce t cells to produce in ... | 1989 | 2785214 |
| developmentally regulated gene from leishmania encodes a putative membrane transport protein. | we have cloned a developmentally regulated gene from the parasitic protozoan leishmania enrietti. the mrna from this gene accumulates to a much higher level in the promastigote stage of the parasite life cycle that lives in the gut of the insect vector than in the amastigote stage of the parasite that lives inside the macrophages of the mammalian host. the predicted protein encoded by this gene is homologous to the human erythrocyte glucose transporter and to several sugar-transport proteins fro ... | 1989 | 2813352 |
| effect of lipopolysaccharide on intracellular killing of leishmania enriettii and correlation with macrophage oxidative metabolism. | the effect of lipopolysaccharide (lps) on the lymphokine (lk)-dependent activation of murine peritoneal macrophages for intracellular killing of leishmania enriettii parasites was investigated. exposure to lps alone did not induce macrophages to kill the parasite. in the presence of lk or recombinant interferon-gamma, however, which by themselves rendered the macrophages only weakly cytotoxic, considerable stimulation of intracellular parasite killing was achieved already at a lps concentration ... | 1987 | 3030768 |
| synthesis of dolichol derivatives in trypanosomatids. characterization of enzymatic patterns. | we have previously described that in certain parasitic protozoa, namely the trypanosomatids, the dolichol-p-p-linked oligosaccharides synthesized in vivo and transferred to protein are devoid of glucose residues and contain 6, 7, or 9 mannose units depending on the species. we have now conducted a cell-free characterization of the enzymatic patterns responsible for these phenotypes. microsomes from trypanosoma cruzi, crithidia fasciculata, leishmania enriettii, and blastocrithidia culicis were f ... | 1987 | 3112153 |
| effect of levamisole on the course of experimental leishmaniasis in guinea-pigs and mice: haematological and immunological findings. | the effects of levamisole on the course of leishmania enriettii infection in guinea-pigs and l. major in mice were investigated. it was demonstrated that levamisole-treated guinea-pigs either did not develop an ulcerative lesion or developed a much smaller lesion than untreated animals. moreover, metastases which are commonly produced in approximately 50% of animals receiving 2 x 10(6) l. enriettii did not occur in levamisole-treated guinea-pigs. leishmania enriettii infection usually causes leu ... | 1988 | 3266914 |
| trans splicing in leishmania enriettii and identification of ribonucleoprotein complexes containing the spliced leader and u2 equivalent rnas. | the 5' ends of leishmania mrnas contain an identical 35-nucleotide sequence termed the spliced leader (sl) or 5' mini-exon. the sl sequence is at the 5' end of an 85-nucleotide primary transcript that contains a consensus eucaryotic 5' intron-exon splice junction immediately 3' to the sl. the sl is added to protein-coding genes immediately 3' to a consensus eucaryotic 3' intron-exon splice junction. our previous work demonstrated possible intermediates in discontinuous mrna processing that conta ... | 1988 | 3405214 |
| a fast and objective assay for cell mediated intra- and extracellular killing of leishmania promastigotes. | an in vitro radiometric assay is described for the detection of cytolytic activity against the obligate intracellular parasite leishmania enriettii. the assay system can be equally well applied to non-cellular (humoral), cellular non-phagocytic, and cellular phagocytic effector situations. leishmania promastigote organisms are dna-labeled with [methyl-3h]thymidine [( 3h]dthd) with high efficiency. spontaneous label release remains very low even in non-ideal culture conditions. we have modeled a ... | 1986 | 3511152 |
| transcriptional mapping of leishmania enrietti tubulin mrnas. | we have mapped the mrnas for alpha- and beta-tubulins of leishmania enriettii promastigotes and amastigotes and have demonstrated that each rna contains a 35 nucleotide sequence on its 5' end which is not encoded contiguously with the rest of the message. sequencing of the 5' end of the alpha- and beta-tubulin mrnas revealed that this 35 nucleotide leader sequence is identical in both messages and that it is homologous to the spliced leader found on the 5' end of mrnas in the related parasite tr ... | 1986 | 3807944 |
| selective lectin reactions of two stocks of leishmania enriettii with differing pathogenicity. | five days old promastigote culture forms of two stocks of leishmania enriettii pathogenic and non-infective for cavia procellus, were tested with the lectins of canavalia ensiformis, ricinus communis-120, soja hispida (glycine maxima), arachis hypogaea, ulex europaeus, ulex europaeus i, ulex europaeus ii, laburnum alpinum, lotus tetragonolobus, euonymus europaeus and with a monoclonal antibody against blood group h. the pathogenic stock reacted with the anti-h lectin of lotus tetragonolobus and ... | 1987 | 3809146 |
| partial purification and characterization of a human lymphokine which induces antileishmanial activity in mouse macrophages. | human blood mononuclear cells stimulated in vitro with concanavalin a secrete a lymphokine which activates mouse macrophages to kill leishmania enriettii. supernatants of cells cultivated for 1 day and for 2 days were analyzed for this activity after g-100 gel filtration and isoelectrofocusing. first day antileishmanial activity was found in a mw range of 23,000 with an isoelectric point of 3.6 to 4.0. second day antileishmanial activity eluted in a peak in the mw range of 23,000 to 65,000 with ... | 1985 | 3881189 |
| protection of guinea pigs against cutaneous leishmaniasis by combined infection and chemotherapy. | a paromomycin and methylbenzethonium chloride ointment cured leishmania enriettii infections in guinea pigs. amastigotes were totally eliminated from the treated lesion after 10 days of treatment. a delayed effect also occurred on untreated lesions in the same animals. lesions treated at various times after infection permitted protective immunity to develop, and 90% of treated animals were refractory to reinfection. | 1986 | 3943909 |
| structure of mrna encoded by tubulin genes in leishmania enriettii. | both the alpha- and beta-tubulin genes of leishmania enriettii are encoded by mrna of 2.0-2.2 kb in length. we have shown previously that the alpha- and beta-tubulin genes are arranged in separate, tandem repeats of 2 and 4 kb, respectively, and now report the mapping of mature mrna onto these cloned genes. here we show that the alpha-tubulin gene contains a very short intergenic region (100-200 bases) whereas the larger, tandemly repeated beta-tubulin gene contains a 1.8-2.0 kb region not found ... | 1985 | 3990710 |
| the effect of prolonged treatment with antilymphocyte serum on the course of infections with bcg and leishmania enriettii in the guinea-pig. | | 1971 | 4108131 |
| immunoflorescence studies of leishmania enriettii infection in the guinea pig. | | 1974 | 4142526 |
| the effect of homologous and heterologous rabbit antisera on the growth of leishmania enriettii, and l. tropica major, and their differentiation by the quantitative adler test. | | 1974 | 4419542 |
| antibody-induced movement of membrane components of leishmania enriettii. | incubation in vitro of viable leishmania enriettii with antibodies from infected or immune guinea pigs and a fluorescein-labeled antiguinea pig ig conjugate induced aggregation of surface antigens to form a "cap" over the anterior pole of the amastigote and over both the anterior and posterior poles of the promastigote form of the parasite. cap formation occurred only with optimum quantities of guinea pig antibodies and was inhibited by low temperature and the metabolic inhibitors, sodium azide ... | 1974 | 4596509 |
| experimental cutaneous leishmaniasis. iv. selective suppression of cell-mediated immunity during the response of guinea-pigs to infection with leishmania enriettii. | | 1974 | 4619589 |
| experimental cutaneous leishmaniasis. iv. selective suppression of cell-mediated immunity during the response of guinea-pigs to infection with leishmania enriettii. | | 1974 | 4619877 |
| experimental cutaneous leishmaniasis. ii. effects of immunosuppression and antigenic competition on the course of infection with leishmania enriettii in the guinea-pig. | | 1972 | 4625799 |
| course of development of leishmania enriettii infection in immunosuppressed guinea pigs. | | 1973 | 4717689 |
| leishmania enriettii: radiation effects and evaluation of radioattenuated organisms for vaccination. | | 1974 | 4815014 |
| histological appearance of the site of inoculation and lymph nodes of guinea-pigs at various times after infection with leishmania enriettii. | | 1972 | 5048788 |
| immunogenicity of a ribosomal antigen of leishmania enriettii. | | 1971 | 5092416 |
| [nutritional deficiency disorders in parasitism by leishmania enrietti. i. aspects of vitamin a deficiency]. | | 1969 | 5409146 |
| the fine structure of leishmania enriettii. | | 1969 | 5789062 |
| [morphologic and cytochemical studies of lymph nodes and spleen in leishmaniasis in guinea-pigs (leishmania enrietti)]. | | 1965 | 5876191 |
| [allergic reactions in guinea-pigs to repeated inoculation with leishmania enrietti]. | | 1965 | 5877785 |
| [immunity in leishmania enriettii infection of the guinea pig]. | | 1965 | 5885827 |
| comparison of the dna's obtained from brain nuclei and mitochondria of mice and from the nuclei and kinetoplasts of leishmania enriettii. | | 1966 | 5970343 |
| identification of galactose as the immunodominant sugar of leishmanial excreted factor and subsequent labeling with galactose oxidase and sodium boro[3h]hydride. | inhibition by low-molecular-weight sugars of precipitin line formation between a polysaccharide (ef) excreted by leishmania tropica subsp. major, leishmania enriettii, and rabbit antileishmanial antibodies on double gel diffusion plates revealed that galactose residues, possibly as components of lactosyl groups, were the critical immunodominant sugars mediating antibody recognition of ef. the galactose residues of the ef of l. tropica subsp. major were specifically labeled with tritium via galac ... | 1982 | 6179874 |
| intracellular destruction of leishmania tropica by macrophages activated with macrophage activating factor/interferon. | supernatants (sn) from cloned t cell lines, lymphokine secreting tumour cell lines and mixed lymphocyte culture were analysed for their ability to induce murine peritoneal exudate cell (pec) macrophages (m phi) parasitized with leishmania tropica to destroy the parasite. the ability of the sn to induce parasite destruction in parasitized pec m phi correlated with their content of macrophage activating factor/interferon. neither granulocyte-macrophage colony stimulating factor, m phi colony stimu ... | 1984 | 6198115 |
| studies on the mechanisms of macrophage activation: possible involvement of oxygen metabolites in killing of leishmania enrietti by activated mouse macrophages. | | 1981 | 6260943 |
| isolation and characterization of an alpha-tubulin gene from leishmania enriettii. | an alpha-tubulin gene of leishmania enriettii has been identified in genomic southern blots by hybridization with a heterologous alpha-tubulin gene from drosophila melanogaster. a clone containing this gene has been isolated from a plasmid library of size-selected l. enriettii dna. it was identified by hybridization with the d. melanogaster tubulin gene. the cloned dna fragment was characterized by restriction analysis and partial dna sequence analysis. the cloned dna fragment is 2 kb in length, ... | 1983 | 6321982 |
| in vitro analysis of immune responses of inbred guinea pigs infected in vivo with leishmania enriettii and an investigation of active immunization of susceptible animals. | adherent skin cell monolayers have been prepared from the infected area of inbred guinea pigs inoculated with leishmania enriettii. cells from those animals most susceptible to disease (2/n) are less able to promote proliferation and the production of macrophage migration inhibition factor (mif) from leishmania-immune lymphocytes than are infected cells taken from the more resistant 13/n or (2/n x 13/n)f1 animals. exposure of immune lymphocytes of all strains to parasite antigen in the relative ... | 1983 | 6339078 |
| activation of the alternative complement pathway by leishmania promastigotes: parasite lysis and attachment to macrophages. | when exposed to normal human or guinea pig sera, promastigotes of leishmania enriettii and l. tropica activate the complement cascade by the alternative pathway and fix c3 on their surfaces. in high (25%) serum concentrations, the result of complement activation is parasite lysis. at lower concentrations (4%), complement fixation results in enhanced parasite binding and uptake into murine peritoneal macrophages. parasites are lysed in normal guinea pig, c4-deficient guinea pig, normal human, and ... | 1984 | 6363545 |
| leishmania enriettii. | | 1983 | 6623603 |
| control of tubulin gene expression in the parasitic protozoan leishmania enriettii. | the life cycle of parasitic protozoa of the genus leishmania consists of two morphologically distinct forms: (1) amastigotes, the form of the parasite that resides inside macrophages of the mammalian host, which are non-motile and possess only a residual flagellum; and (2) promastigotes, the extracellular forms that live in the gut of the sandfly vector, which are highly motile and possess a single prominent flagellum. during the developmental transformation of amastigotes to promastigotes, the ... | 1984 | 6728033 |
| macrophage heterogeneity and ir-gene control as factors involved in the immune response of guinea pigs to infection with leishmania enrietti. | | 1981 | 6786761 |
| tandem arrangement of tubulin genes in the protozoan parasite leishmania enriettii. | the arrangement of developmentally regulated alpha- and beta-tubulin genes has been studied in the parasitic protozoan leishmania enriettii by using southern blot hybridization analysis. the alpha-tubulin genes occur in a tandem repeat whose monomeric unit may be represented by a 2-kilobase psti fragment. similarly, the beta-tubulin genes probably occur in a separate tandem repeat consisting of approximately 4-kilobase units unlinked to the alpha-tubulin repeats. | 1983 | 6877238 |
| leishmania enriettii: immune induction of macrophage activation in an experimental model of immunoprophylaxis in the mouse. | | 1981 | 6976270 |
| the identity of so-called leishmania enriettii. | | 1982 | 7080146 |
| leishmania enriettii amastigotes: demonstration of fibrillar surface. | an extensive fibrillar surface was identified in situ by transmission electron microscopy on the amastigote stage of the macrophage intracellular parasite, leishmania enriettii. attachment to the amastigote surface of 20-160-nm fibrils was clearly evident on organisms that had been isolated from guinea pigs. surface fibrils were not detected after in vitro transformation of the amastigote to the promastigote. incubation of amastigotes in heat-inactivated guinea pig serum containing a high titer ... | 1982 | 7142748 |
| histological studies of the elimination of leishmania enriettii from skin lesions in the guinea-pig. | nineteen guinea-pigs were each inoculated intradermally with 10(6) amastigotes of leishmania enriettii, and the development of the lesions was followed from weeks 4 to 10 with a view to elucidating the histological mechanisms involved with the elimination of parasites. electron microscopic observations were made in 1 animal. extensive necrosis of the parasite-laden macrophages was observed in 7 out of 7 animals at 4 and 5 weeks. in the ulcerated core of the lesion at 4 weeks no intact macrophage ... | 1980 | 7459254 |
| effect of increasing intravesicular ph on nitrite production and leishmanicidal activity of activated macrophages. | we examined the effect of bafilomycin a1 (baf), an inhibitor of vacuolar-type h(+)-atpases, on macrophages activation (measured as increased nitrite production and leishmanicidal activity) induced by interferon gamma alone or together with lipopolysaccharide or tumour necrosis factor alpha. baf increased intravesicular ph and enhanced nitrite release by activated macrophages; however, the no concentration necessary to kill parasites was higher in baf-exposed than control macrophages, suggesting ... | 1994 | 7518670 |
| differential targeting of two glucose transporters from leishmania enriettii is mediated by an nh2-terminal domain. | leishmania are parasitic protozoa with two major stages in their life cycle: flagellated promastigotes that live in the gut of the insect vector and nonflagellated amastigotes that live inside the lysosomes of the vertebrate host macrophages. the pro-1 glucose transporter of l. enriettii exists as two isoforms, iso-1 and iso-2, which are both expressed primarily in the promastigote stage of the life cycle. these two isoforms constitute modular structures: they differ exclusively and extensively ... | 1995 | 7532172 |
| effect of pge2 and of agents that raise camp levels on macrophage activation induced by ifn-gamma and tnf-alpha. | the effect of prostaglandin (pg) e2 on macrophage activation by interferon-gamma (ifn-gamma) and tumor necrosis factor-alpha (tnf-alpha) was evaluated. murine macrophages infected with leishmania enriettii or leishmania major were activated by exposure to ifn-gamma (10-50 u/ml) and tnf-alpha (30-3000 u/ml), leading to intracellular parasite destruction within 24-48 h. leishmanicidal activity was markedly increased when activation was performed in the presence of pge2 (10(-9)-10(-7) m) or arachid ... | 1995 | 7543922 |
| differential turn-over of beta-tubulin during the cell differentiation of trypanosoma cruzi. | we investigated the expression of beta-tubulin during the differentiation of non-infective epimastigotes to infective metacyclics of trypanosoma cruzi to underlay some of the regulatory mechanisms of the gene expression in this pathogenic parasite. given the strong evolutionary conservation of tubulin, it was possible to study its translational and transcriptional products with heterologous probes. quantitative western blotting with specific monoclonal antibodies against beta-tubulin revealed an ... | 1993 | 7670545 |
| partial protection against malaria by immunization with leishmania enriettii expressing the plasmodium yoelii circumsporozoite protein. | since infection with leishmania species induces cd4+ and cd8+ anti-leishmania t cells, we assessed protection against malaria by immunization with leishmania enriettii transfected with the gene encoding the plasmodium yoelii circumsporozoite protein (pycsp). the recombinant plasmid appeared to be a circular episome in the host cells. reverse transcription pcr showed that the pycsp was trans-spliced by the addition of the 39-bp spliced leader of l. enriettii at its 5' end. the transfectant expres ... | 1995 | 7770079 |
| identification of a cis-acting gene regulatory element from the lemdr1 locus of leishmania enriettii. | the goal of this work is to identify those elements which control gene expression in the parasitic protozoan, leishmania enriettii. to date there has been no report of a transcriptional controlling element identified in this parasite. in the present study, we have found that a region of the lemdr1 locus of l. enriettii can down-regulate the steady state mrna level of the reporter neomycin phosphotransferase gene when it is placed in an extrachromosomal expression vector, paltneo. through deletio ... | 1994 | 7929372 |
| functional expression of two glucose transporter isoforms from the parasitic protozoan leishmania enriettii. | the parasitic protozoan leishmania enriettii contains a family of tandemly repeated genes, designated pro-1, that encode proteins with significant sequence similarity to mammalian facilitative glucose transporters. pro-1 mrnas are expressed almost exclusively in the promastigote or insect stage of the parasite life cycle. the pro-1 tandem repeat encodes two isoforms of the putative transporter, iso-1 and iso-2, which have identical predicted amino acid sequences except for their nh2-terminal hyd ... | 1994 | 8027051 |
| naturally acquired infections with leishmania enriettii muniz and medina 1948 in guinea-pigs from são paulo, brazil. | two domestic guinea-pigs (cavia porcellus), bought in pinheros, são paulo state, brazil, were taken by their owners to a farm in the rural district of capão bonito, close to the atlantic forest, são paulo, where they both developed tumour-like and ulcerating lesions on the ears. the causative agent was identified as leishmania (l.) enriettii, based on biological characters and isoenzyme profiles. sources of the parasite in wild mammals, and the possible sandfly vector species are discussed. | 1994 | 8084659 |
| transforming growth factor beta 1 regulation of macrophage activation depends on the triggering stimulus. | we have examined the effects of transforming growth factor beta 1 (tgf-beta 1) on the regulation of murine bone marrow-derived macrophage function. tgf-beta, added simultaneously with or up to 4 h before interferon-gamma (ifn-gamma) plus lipopolysaccharide (lps), inhibited macrophage leishmanicidal activity, nitrite (no2-) production, and secretion of prostaglandin e2. in contrast, no effect of tgf-beta could be demonstrated on macrophages stimulated with ifn-gamma plus tumor necrosis factor-alp ... | 1993 | 8228620 |
| cloning and functional analysis of an extrachromosomally amplified multidrug resistance-like gene in leishmania enriettii. | the goal of this work was to investigate the mechanism of drug resistance in leishmania enriettii as a model system for drug resistance both in human leishmaniasis and on other parasitic diseases. parasites were selected in increasing concentrations of vinblastine, an inhibitor of microtubule assembly, and resistant clones were isolated which grew in concentrations 5-30 times the ic50 (30 micrograms ml-1) of parental cells. the vinblastine-resistant parasites were also resistant to puromycin, an ... | 1993 | 8232412 |
| bactericidal/permeability-increasing protein inhibits induction of macrophage nitric oxide production by lipopolysaccharide. | a recombinant (r) nh2-terminal fragment of bactericidal/permeability-increasing protein, rbpi23, was shown to inhibit murine macrophage nitric oxide (no) production elicited by lipopolysaccharide (lps) plus interferon-gamma (ifn-gamma). normal mouse plasma amplified no synthesis (measured as no2- release) at lps concentrations of 1-10 ng/ml, and antibody to the plasma lps-binding protein (lbp) partially inhibited no2- release in the presence of normal mouse plasma. rbpi23 (1 microgram/ml) effect ... | 1994 | 8277172 |
| polysaccharides isolated from plant cell cultures of echinacea purpurea enhance the resistance of immunosuppressed mice against systemic infections with candida albicans and listeria monocytogenes. | polysaccharides (ep) isolated from large scale plant cell cultures of echinacea purpurea, have been shown to activate human and murine phagocytes. in this study we investigated the influence of ep on the nonspecific immunity in immunodeficient mice. ep was effective in activating peritoneal macrophages isolated from animals after administration of cyclophosphamide (cp) or cyclosporin a (csa). ep-treated macrophages exhibited increased production of tumor necrosis factor-alpha (tnf) and enhanced ... | 1993 | 8375943 |
| new isolation of leishmania enriettii muniz and medina, 1948 in paranástate, brazil, 50 years after the first description, and isoenzymatic polymorphism of the l. enriettii taxon. | three cases of cutaneous leishmaniasis in guinea-pigs from a rural area near curitiba (paraná state, brazil) are reported. the three parasite isolates were characterized by isoenzyme electrophoresis as leishmania enriettii, of which two distinct zymodemes were observed. | 1996 | 8915125 |
| receptors for carbohydrate ligands including heparin on the cell surface of leishmania and other trypanosomatids. | by employing neoglycoproteins (ngp) and glycosaminoglycans, the detection of endogenous glycoligand-binding sites has become possible. monitoring specific binding of 11 of these sugar receptor-specific tools, 13 trypanosomatids of monogenetic genera blastocrithidia, crithidia, herpetomonas, and leptomonas and digenetic genera endotrypanum, leishmania, and sauroleishmania were analysed by agglutination and fluorescence assays. ngp showed agglutination reactions only with the digenetic but not wit ... | 1997 | 9315045 |
| leishmania spp.: mechanisms of toxicity of nitrogen oxidation products. | intracellular killing of leishmania parasites within activated murine macrophages is thought to result from the toxic activities of nitrogen oxidation products (referred to as no) released by the activated cells. in order to determine possible mechanisms of no toxicity for these microorganisms, promastigotes of leishmania major and leishmania enriettii were exposed to no generated chemically from acidified nitrite, s-nitrosocysteine, diethylamine nonoate, or nitroprusside. treatment with these a ... | 1997 | 9326885 |
| on leishmania enriettii and other enigmatic leishmania species of the neotropics. | there are 20 named species of the genus leishmania at present recognized in the new world, of which 14 are known to infect man. the present paper discusses the biological, biochemical and ecological features, where known, of six species which have not till now been found to cause human leishmaniasis; namely, leishmania (leishmania) enriettii, l. (l.) hertigi, l. (l.) deanei, l. (l.) aristidesi, l. (l.) forattinii and l. (viannia) equatorensis. a protocol is suggested for attempts to discover the ... | 1997 | 9332605 |
| cytoskeletal association is important for differential targeting of glucose transporter isoforms in leishmania. | the major glucose transporter of the parasitic protozoan leishmania enriettii exists in two isoforms, one of which (iso-1) localizes to the flagellar membrane, while the other (iso-2) localizes to the plasma membrane of the cell body, the pellicular membrane. these two isoforms differ only in their cytosolic nh2-terminal domains. using immunoblots and immunofluorescence microscopy of detergent-extracted cytoskeletons, we have demonstrated that iso-2 associates with the microtubular cytoskeleton ... | 1997 | 9412471 |
| detection of parasites with dna-binding bisbenzimide h33258 in pneumocystis carinii- and leishmania-containing materials. | even for routine purposes, standard staining of pneumocystis- or leishmania-containing materials, e.g., with giemsa or diff-quik, is often unsatisfactory due to poor contrast and to staining of irrelevant structures. in comparison, the bisbenzimide dye hoechst 33258, a dna-binding fluorochrome, allows a more precise analysis of such materials. bisbenzimide stained all stages of these fungal or protozoal organisms with brilliant contrast against a uniformly dark background. the level of backgroun ... | 1998 | 9694372 |
| characterization of a targeting motif for a flagellar membrane protein in leishmania enriettii. | the surface membranes of eukaryotic flagella and cilia are contiguous with the plasma membrane. despite the absence of obvious physical structures that could form a barrier between the two membrane domains, the lipid and protein compositions of flagella and cilia are distinct from the rest of the cell surface membrane. we have exploited a flagellar glucose transporter from the parasitic protozoan leishmania enriettii as a model system to characterize the first targeting motif for a flagellar mem ... | 1999 | 10506220 |
| comparison of adjuvants with leishmania antigens in a guinea pig model to induce delayed-type hypersensitivity responses. | guinea pigs have been a traditional model for studies of delayed-type hypersensitivity. they are the natural host of leishmania enriettii and have been experimentally infected with other species of leishmania. they have been used as a skin-test model to screen potential antigens for use in diagnostic tests for leishmania. use of complete freund's adjuvant (cfa), along with whole promastigote leishmania antigen, was necessary to sensitize guinea pigs to invoke a sufficient cell-mediated immune re ... | 1999 | 10551453 |