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chronic infection by leishmania amazonensis mediated through mapk erk mechanisms.leishmania amazonensis is an intracellular protozoan parasite responsible for chronic cutaneous leishmaniasis (cl). cl is a neglected tropical disease responsible for infecting millions of people worldwide. l. amazonensis promotes alteration of various signaling pathways that are essential for host cell survival. specifically, through parasite-mediated phosphorylation of extracellular signal regulated kinase (erk), l. amazonensis inhibits cell-mediated parasite killing and promotes its own survi ...024838145
leishmania amazonensis exhibits phosphatidylserine-dependent procoagulant activity, a process that is counteracted by sandfly saliva.leishmania parasites expose phosphatidylserine (ps) on their surface, a process that has been associated with regulation of host's immune responses. in this study we demonstrate that ps exposure by metacyclic promastigotes of leishmania amazonensis favours blood coagulation. l. amazonensis accelerates in vitro coagulation of human plasma. in addition, l. amazonensis supports the assembly of the prothrombinase complex, thus promoting thrombin formation. this process was reversed by annexin v whic ...024037188
leishmaniasis in brazil. vi. observations on the seasonal variations of lutzomyia flaviscutellata in different types of forest and its relationship to enzootic rodent leishmaniasis (leishmania mexicana amazonensis). 19724647642
letter: further evidence of the rôle of lutzomyia flaviscutellata (mangabeira) as the vector of leishmania mexicana amazonensis in brazil. 19734785465
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 ...197552214
leishmania in phlebotomid sandflies. iii. the ultrastructure of leishmania mexicana amazonensis in the midgut and pharynx of lutzomyia longipalpis. 1975240164
the colonization of lutzomyia flaviscutellata (diptera: psychodidae), a vector of leishmania mexicana amazonensis in brazil. 1977609078
leishmania in phlebotomid sandflies. iv. the transmission of leishmania mexicana amazonensis to hamsters by the bite of experimentally infected lutzomyia longipalpis. 197715270
isolation of the intracellular stages of leishmania mexicana amazonensis using cellulose column. 1978736664
[dissemination of leishmania mexicana amazonensis by intracardiac inoculation by pretreatment with gastric mucin (author's transl)]. 1978757721
[new observations upon genital lesions caused by leishmania mexicana amazonensis (author's transl)]. 1978575597
freeze-fracture study of the plasma membrane of leishmania mexican amazonensis.the fine structure of the plasma membrane of promastigotes of leishmania mexicana amazonensis was studied by freeze-fracture techniques. measurement of the number of intramembranous particles per square micrometer of membrane area revealed a particle density of 2,040 +/- 213/micron2 on the p-face and 890 +/- 186/micron2 on the e-face. the particle density of the flagellar membrane was 448 +/- 53/micron2. clusters of intramembranous particles were seen on the flagellar membrane at the region of a ...19807218117
isolation of an enriched plasma membrane-subpellicular microtubule fraction of leishmania mexicana amazonensis. 19807231156
some methods for the enzymic characterization of latin-american leishmania with particular reference to leishmania mexicana amazonensis and subspecies of leishmania hertigi.30 brazilian stocks of leishmania mexicana amazonensis and 13 stocks of subspecies of leishmania hertigi were characterized by starch-gel electrophoresis, using 18 enzymes selected from a total of 36 investigated. l. m. amazonensis was separable from subspecies of l. hertigi by enzymic profiles of 11 enzymes. the l. m. amazonensis stocks, which were from a wide range of hosts in a large geographical area, were enzymically extremely homogeneous, and could only be subdivided on two enzymes; sub-gr ...19807385303
human cutaneous lieshmania in a mouse macrophage line: propagation and isolation of intracellular parasites.a mouse macrophage line, j774g8, supports continuous and prolific intracellular growth of leishmania mexicana amazonensis, the etiological agent of a south american cutaneous leishmaniasis. the intracellular parasites from these infected cultures can be isolated with high recovery rate and purity by simple percoll gradient centrifugation.19807403880
infection of mouse macrophages in vitro by sandfly-derived promastigotes of leishmania mexicana amazonensis. 19817324121
leishmaniasis in brazil: xv. biochemical distinction of leishmania mexicana amazonensis, l. braziliensis braziliensis and l. braziliensis guyanensis--aetiological agents of cutaneous leishmaniasis in the amazon basin of brazil.enzymic profiles of the three known agents of human cutaneous leishmaniasis in the lower amazon region are compared. of 14 enzymes, 10 (asat, alat, gpi, g5pd, mdh, acon, pep, hk, mpi and acp) differentiate leishmania mexicana amazonensis from l. braziliensis braziliensis or l. braziliensis guyanensis: this supports their taxonomic status as distinct species. in contrast, only slight mobility differences of four enzymes (asat, alat, pgm, mpi) separate l. b. braziliensis and l. b. guyanensis, whic ...19817324127
leishmaniasis in brazil: xvi. isolation and identification of leishmania species from sandflies, wild mammals and man in north para state, with particular reference to l. braziliensis guyanensis causative agent of "pian-bois".a total of 125 wild mammals (14 different species) were examined for evidence of infection with leishmania in an area of primary forest highly endemic for "pian-bois", due to leishmania braziliensis guyanensis, in north pará state, brazil. parasites isolated were characterized biologically, and biochemically on enzymic profiles. l. b. guyanensis was isolated from the viscera of one lesser anteater (tamandua tetradactyla) and one opossum (didelphis marsupialis), and the skin of one rodent (proech ...19817324128
the opossum, didelphis marsupialis (marsupialia: didelphidae), as a reservoir host of leishmania braziliensis guyanensis in the amazon basin of brazil.a total of 52 opossums (six species) were examined for evidence of infection with leishmania in three different areas of forest near manaus, amazonas state, brazil. no infections were detected in 27 opossums from a region of relatively undisturbed forest, including specimens of didelphis marsupialis (18); metachirus nudicaudatus (four); monodelphis brevicaudata (one); marmosa cinerea (two); m. murina (one) and m. parvidens (one). of 15 d. marsupialis captured from a biological reserve, much dist ...19817324129
leishmania mexicana amazonensis: attachment to the membrane of the phagocytic vacuole of macrophages in vivo.intracellular forms of leishmania mexicana amazonensis divide inside the phagocytic vacuole of macrophages. some parasites attach to the membrane of the phagocytic vacuole while others remain free in the vacuole. examination of thin sections of the attachment region by electron microscopy revealed a space of 2 nm between the membrane of the phagocytic vacuole and the plasma membrane of the parasite. freeze-fracture replicas showed an array of intramembranous particles in some areas of the parasi ...19817324540
tubulin biosynthesis in the developmental cycle of a parasitic protozoan, leishmania mexicana: changes during differentiation of motile and nonmotile stages.cytodifferentiation in the transition cycle of the parasitic protozoan leishmania mexicana amazonensis was studied in vitro. the flagellated motile promastigotes transform into the nonmotile amastigotes in 7 days at 35 degrees c intracellularly in the murine macrophage line j774g8. in medium 199 plus fetal bovine serum, the reverse transformation occurs extracellularly at 27 degrees c in 2 days. slab gel electrophoresis of leishmanias labeled with [35s]methionine during transformation revealed c ...19816950404
leishmaniasis in brazil. xiv. leishmanial and trypanosomal iga antibody in patients with leishmaniasis and chagas's disease.preserved sera from patients with various forms of leishmaniasis, acute and chronic chagas's disease and from normal individuals were examined for the presence of igg and iga antibodies by the ifa test. the leishmanial antigen used in the ifa test was prepared from a hamster infected with the ph8 strain of leishmania mexicana amazonensis; amastigotes were isolated from a skin lesion and fixed in formal phosphate-buffered saline-glucose for slide antigen. there were significantly more positive re ...19816795770
accumulation of [125sb]sodium stibogluconate by leishmania mexicana amazonensis and leishmania donovani in vitro. 19816108831
potentiating action of rifampicin and isoniazid against leishmania mexicana amazonensis.the treatment of the complex of diseases known as leishmaniasis, caused by infection with protozoal parasites, is often unsatisfactory. the response to chemotherapy depends not only on the species of infecting leishmania but also on the immune reactions of the host. this creates difficulties in evaluating any new drug in clinical trials. in a brazilian patient with diffuse cutaneous leishmaniasis, which classical antileishmanial drugs had failed to cure, antituberculous therapy of an intercurren ...19816112485
surface antigenic change during differentiation of a parasitic protozoan, leishmania mexicana: identification by monoclonal antibodies.the fusion of sp2/0 myeloma cells with spleen cells from mice immunized with leishmania mexicana amazonensis promastigotes produced hybridoma clones. indirect immunofluorescent antibody assay with live leishmanias showed that the monoclonal antibody 6h12 recognized only the antigens bound to the surface of l. mexicana amazonensis promastigotes. it also showed that the antibody bound to neither amastigotes of this species nor to other leishmania species--i.e., l. braziliensis braziliensis, l. tro ...19826961414
destruction of leishmania mexicana amazonensis amastigotes within macrophages in culture by phenazine methosulfate and other electron carriers.exposure of macrophages infected with leishmania mexicana amazonensis to phenazine methosulfate (pms) resulted in rapid damage and disappearance of the intracellular amastigotes without obvious ill effects to the host cells. the reduction of the percent infection was related to the concentration of pms and to the duration of the pulse. most leishmania disappeared within 2 h of a 2-h pulse with 10 mum of the drug. in contrast, pretreatment of the macrophages with pms followed by removal of the dr ...19827057140
effect of pentamidine isethionate on the ultrastructure and morphology of leishmania mexicana amazonensis in vitro. 19827082077
monoclonal antibodies recognizing determinants specific for the promastigote state of leishmania mexicana.two monoclonal antibodies (ix-if9-d8 and ix-5h9=c1) produced to a membrane enriched fraction of leishmania mexicana amazonensis promastigotes have been demonstrated to be specific for the promastigote (insect) form and not the amastigote (mammalian host) form of the parasite. the antigens recognized by these monoclonal antibodies are not found on amastigotes isolated from infected animals or on amastigotes isolated from a macrophage cell line j774 infected initially with promastigotes. the antig ...19827177168
ump synthesis in the kinetoplastida.all six enzymes of pyrimidine biosynthesis de novo have been detected in homogenates of the culture promastigote form of leishmania mexicana amazonensis, the blood trypomastigote form of trypanosoma brucei and the culture epimastigote, blood trypomastigote and intracellular amastigote forms of trypanosoma cruzi. dihydroorotate dehydrogenase is mitochondrial in mammals, but the isofunctional enzyme, dihydroorotate oxidase was found to be cytoplasmic, whereas orotate phosphoribosyltransferase and ...19826753942
leishmania mexicana: acid phosphatase ultrastructural cytochemistry of infected mouse macrophage cultures treated with phenazine methosulfate.bone marrow-derived mouse macrophage cultures infected with leishmania mexicana amazonensis amastigotes were given a 2-hr pulse with 10 microm phenazine methosulfate (pms), a cationic electron carrier which destroys the intracellular parasites. cultures were fixed at different times after the pms pulse and processed for the detection of acid phosphatase (acp) activity at the electron microscopic level. only a small proportion of nontreated, infected macrophages stained for acp. in contrast, 2 to ...19836832281
uptake and killing of leishmania mexicana amazonensis amastigotes by human skin fibroblasts.this paper describes the in vitro infection of human established fibroblast lines by leishmania mexicana amazonensis amastigotes. intracellular parasites were located within vacuoles. the proportion of infected cells reached a peak of about 50% on days 2 or 3, and decreased to almost 0 on days 6 or 8. transmission electron microscopy was used to document different stages of the degeneration of l. m. amazonensis amastigotes on days 4 and 5. the proportion of infected fibroblasts decreased in both ...19836882054
leishmania mexicana amazonensis: surface charge of amastigote and promastigote forms.the surface charge of leishmania mexicana amazonensis was evaluated by means of the binding of colloidal iron hydroxyde particles at ph 1.8 and cationized ferritin particles at ph 7.2 to the cell surface, visualizated by electron microscopy and by direct measurements of the electrophoretic mobility of cells suspended in solutions of different ph. the following forms of the parasite were analysed: amastigotes (surrounded or not by the membrane of the endocytic vacuole, isolated from lesions), tra ...19836617803
isolation and purification of amastigotes of leishmania mexicana amazonensis by a gradient of metrizamide. 19836631632
leishmaniasis in brazil: xx. prevalence of "enzootic rodent leishmaniasis" (leishmania mexicana amazonensis), and apparent absence of "pian bois" (le. braziliensis guyanensis), in plantations of introduced tree species and in other non-climax forests in eastern amazônia.in amazonian brazil most human leishmaniasis is due to leishmania braziliensis s.l. and is acquired during the clearing of primary climax forest. one of the largest deforestation projects has taken place on the jari property where plantations of exotic tree species are grown for paper pulp. the ability of the regional leishmaniasis enzootics to invade plantations was investigated. cdc light-trap catches indicated the phletobomine vectors of le. b. guyanensis (causing "pian bois" in man) to be ve ...19836665830
detection of promastigote stage-specific antigens on leishmania mexicana amazonensis developing in the midgut of lutzomyia longipalpis.previously described monoclonal antibodies ix-if9-d8, ix-2h7-e10 and ix-5h9-c1 recognize promastigote stage-specific determinants present on externally exposed membrane proteins of axenically cultured leishmania mexicana amazonensis. in the present study, these antigens were demonstrated by indirect immunofluorescence to be present on promastigotes found in the gut lumen of infected lutzoymia longipalpis. the presence of these antigens on promastigotes found in infected sandflies suggests that t ...19836359907
leishmania mexicana: temperature sensitivity of isolated amastigotes and of amastigotes infecting macrophages in culture.different temperature requirements for intracellular growth of leishmania spp. may account for the predominantly peripheral or visceral localization of the parasites in the vertebrate host. we show here that leishmania mexicana amazonensis, an agent of cutaneous disease, is growth restricted in vitro at 37.5 c and viable at 34 c. this temperature sensitivity has been observed in both infected macrophage cultures and isolated amastigotes. counts of the percentage of infected macrophages and of th ...19836196227
receptor-mediated entry of beta-glucuronidase into the parasitophorous vacuoles of macrophages infected with leishmania mexicana amazonensis.125i-labeled rat preputial gland beta-glucuronidase was shown by light and electron microscopic radioautography to accumulate within the parasitophorous vacuoles of in vitro derived bone marrow macrophages infected with leishmania mexicana amazonensis. beta-glucuronidase uptake was mediated by the mannose receptor, since the penetration of the ligand was inhibited by mannan. uptake was detected as soon as 4 h after incubation of infected cells with the ligand, and increased at 24 and 48 h. the l ...19836304225
the enzymes of purine salvage in trypanosoma cruzi, trypanosoma brucei and leishmania mexicana.we have previously shown the presence of various purine salvage enzymes in trypanosoma cruzi, including phosphoribosyltransferase, aminohydrolase, kinase, phosphorylase and hydrolase activities. we now report that a similar situation occurs in leishmania mexicana amazonensis and trypanosoma brucei brucei. in all three organisms we found higher levels of activity for the phosphoribosyltransferase enzymes than for the nucleoside kinases, suggesting a preference for the salvage of purine bases rath ...19836316234
inhibition by superoxide dismutase and catalase of the damage of isolated leishmania mexicana amazonensis by phenazine methosulfate.phenazine methosulfate, a cationic electron carrier, inhibits the extracellular growth of promastigotes and the conversion of amastigotes into promastigote forms of leishmania mexicana amazonensis. growth inhibition and damage of extracellular parasites by pms was counteracted by superoxide dismutase, a scavenger of the superoxide anion (o2-), and to a lesser extent, by catalase, a scavenger of hydrogen peroxide (h2o2). inactivated dismutase and catalase were ineffective. thus, damage of isolate ...19846328296
formation of (1----2)-linked beta-d-mannopyranan by leishmania mexicana amazonensis: relationship with certain crithidia and herpetomonas species. 19846491853
amyloidosis in experimental tegumentary leishmaniasis in mice.renal and hepatosplenic amyloidosis was found in chronic cutaneous leishmaniasis in mice infected with 10(6) purified amastigotes from lesions produced by the h21 strain of leishmania mexicana amazonensis. after 1 year a progressive lesion leading to metastasis was observed in most animals.19846507735
[cutaneous leishmaniasis in amazonia. report of the 1st human case of mixed infection, determined by 2 different leishmania species: leishmania brasiliensis and leishmania mexicana amazonensis]. 19846533750
differential expression of mrnas for alpha- and beta-tubulin during differentiation of the parasitic protozoan leishmania mexicana.the parasitic protozoan leishmania mexicana amazonensis has two developmental stages: a motile flagellated promastigote stage and a sessile intracellular amastigote stage. in our previous work, cells of the promastigote stage were found to synthesize more tubulin protein than those of the amastigote stage. here, tubulin mrnas in these leishmanias were analyzed. based on dot blot hybridization between total leishmanial rna and tubulin-specific cdna probes derived from chicken brain, amastigotes a ...19846592587
immunopathology of experimental cutaneous leishmaniasis.relatively susceptible balb/c and relatively resistant a/j mice were infected subcutaneously in the right hind footpad with promastigotes of leishmania mexicana amazonensis. a large localized lesion developed within 2 months after infection in the balb/c mice, while a/j mice exhibited a small discrete fibrotic nodule. sequential immunologic and histologic examination demonstrated that balb/c mice developed a nodular foam-cell type of lesion and progressive depression of a delayed-type hypersensi ...19846691411
the activity of plumbagin and other electron carriers against leishmania donovani and leishmania mexicana amazonensis. 19853834847
flagellates in the malpighian tubules of laboratory-bred lutzomyia longipalpis fed on a hamster experimentally infected with leishmania mexicana amazonensis.as a preparatory stage for a study aiming at identifying the species and subspecies of local leishmania in naturally infected sandflies through immunoradiometric assay with monoclonal antibodies, we tried to obtain experimental infections of phlebotomines with well characterized stocks of parasites, in order to test the effectiveness of the method.19853837172
receptor-mediated entry of peroxidases into the parasitophorous vacuoles of macrophages infected with leishmania mexicana amazonensis.leishmania amastigotes, obligatory parasites of macrophages, lodge and multiply within long-lived phagolysosomelike "parasitophorous vacuoles" (pv). the glycoprotein horseradish peroxidase (hrp) was shown, by light and electron microscopic cytochemistry, to enter the pvs of rat in vitro-derived bone marrow macrophages infected with leishmania mexicana amazonensis. uptake was obtained both in preinfected macrophages incubated with hrp and in macrophages pulsed with hrp, infected, and further incu ...19853855437
hypergammaglobulinaemia in leishmania donovani infected hamsters: possible association with a polyclonal activator of b cells and with suppression of t cell function.studies were carried out on the mechanisms by which b lymphocytes are polyclonally activated to secrete antibodies during visceral leishmaniasis. crude extracts of leishmania donovani, the aetiological agent of this disease, of leishmania mexicana amazonensis, the etiological agent of cutaneous leishmaniasis, and of herpetomonas muscarum, a related non-pathogenic organism, all contain components which cause strong in vitro polyclonal activation of hamster spleen cells leading to the production o ...19853872189
[efficacy of the vaccination of c57bl/6 mice against infection with different species of leishmania].antigens were isolated from lysates of promastigotes of leishmania infantum by electro-elution from polyacrylamide gels. antigens with respective molecular weights for f2 = 94-67 kd; f5 = 30-20 kd and f6 below 20 kd, were injected intravenously in c 57 bl/6 mice. the immune sera were studied by indirect immunofluorescence; an in vivo test showed their inhibitory effect on the life cycle of several leishmania species from the old and the new world. furthermore, mice immunized with f2, f5 or f6 we ...19853936605
[the 2 first cases of cutaneous leishmaniasis due to leishmania mexicana amazonensis in french guiana].the authors report the two first proven cases of cutaneous leishmaniasis due to leishmania mexicana amazonensis in french guiana. they present some observations on the situation of cutaneous leishmaniasis epidemiology in this country.19853986952
depletion of secondary lysosomes in mouse macrophages infected with leishmania mexicana amazonensis: a cytochemical study.leishmania amastigotes lodge and multiply within parasitophorous vacuoles, which can fuse with secondary lysosomes of the host macrophages. this study examines the effect of infection with amastigotes of l. mexicana amazonensis on the secondary lysosomes of mouse macrophage cultures. the cultures were stained for the activities of two lysosomal enzyme markers, acid phosphatase and arylsulfatase, and the light microscopic observations were supplemented by electron microscopy. nearly all noninfect ...19853993184
[immunization of balb/c mice with cultured amastigotes of leishmania mexicana amazonensis: protection by gamma-irradiated parasites]. 19854012583
fine structure and cytochemistry of the endoplasmic reticulum and its association with the plasma membrane of leishmania mexicana amazonensis.promastigotes of leishmania mexicana amazonensis possess an elaborated system of cytoplasmic membranes which is clearly visualized when the cells are fixed in a glutaraldehyde solution containing ca++ and post-fixed in an osmium tetroxide solution containing ca++ and potassium ferricyanide. when the parasites are incubated in a medium containing glucose-6-phosphate and lead nitrate, reaction product indicative of glucose-6-phosphatase activity is seen in the membrane system confirming that it co ...19854020925
natural hosts of leishmania mexicana amazonensis lainson and shaw, 1972 (kinetoplastida: trypanosomatidae) in french guiana. 19854035728
development of infective stage leishmania promastigotes within phlebotomine sand flies.midgut promastigotes were obtained from phlebotomus papatasi and lutzomyia longipalpis on days 3-7 after infection with cloned isolates of leishmania major and leishmania mexicana amazonensis, respectively, and examined as to their ability to initiate cutaneous infections in balb/c mice. sequential development of midgut promastigotes from a noninfective to an infective stage was confirmed for both the new world and old world species. the generation of infective promastigotes from rapidly dividin ...19854039899
heme requirement and acquisition by extracellular and intracellular stages of leishmania mexicana amazonensis.the inability to synthesize heme, a well known metabolic defect of trypanosomatid protozoa, accounts for their growth requirement for heme compounds in vitro. we now extend this finding to a pathogen leishmania mexicana amazonensis, especially the intracellular replicative stage of amastigotes in the macrophage. we measured the level of heme and its biosynthetic enzymes, aminolevulinate dehydratase and porphobilinogen deaminase in the parasites and in infected and non-infected macrophages of j77 ...19854058483
[current aspects of endemic mucocutaneous leishmaniasis in brazil].mucocutaneous leishmaniasis has a large incidence in brazil. biochemical, immunological and biological studies have characterized three disease agents: leishmania mexicana amazonensis, leishmania brasiliensis guyanensis and leishmania brasiliensis brasiliensis; these have distinct geographical distributions. the last one is the most common and is the most difficult to treat. destructive mucosal lesions can occur days, months or years after the cutaneous lesions. the montenegro intradermal test, ...19854066323
[effect of sex hormones on experimental infections induced by a strain of leishmania mexicana amazonensis from venezuela]. 19854095406
[epidemiological characteristics of american cutaneous leishmaniasis in an endemic region of the state of bahia. iii. phlebotomine fauna].the phlebotomine fauna is highly varied in três braços, an endemic area of american cutaneous leishmaniasis, situated in the cacao growing region in the southeast of bahia state, brazil. thirty spécies of the lutzomyia genus were identified in 13,535 specimens collected between 1976 and 1984. lutzomyia whitmani was the dominant species accounting for 99% of flies in the peridomicile and 97.5% of those caught in homes. in the forest the predominant species were lu. ayrozai and lu. yuilli. lu. whi ...19863574127
structural observations on the attachment of promastigotes of leishmania mexicana amazonensis to the surface of macrophages. 19863587059
expression and size heterogeneity of a 63 kilodalton membrane glycoprotein during growth and transformation of leishmania mexicana amazonensis.our previous work by immunoprecipitation with a specific monoclonal antibody showed multiple, closely apposed electrophoretic bands of a major surface antigen specific to the promastigote stage of leishmania mexicana amazonensis. here, we analyzed the antigen during growth and transformation of this parasite with particular emphasis on the origin of the multiple bands. immunobinding assays revealed the presence of the antigen throughout all phases of growth of cloned and uncloned promastigotes i ...19863515177
cell surface carbohydrate of leishmania mexicana amazonensis: differences between infective and non-infective forms.the cell surface carbohydrates of leishmania mexicana amazonensis (amastigotes and promastigotes, both infective and non-infective forms) were comparatively analyzed by agglutination assay employing 28 highly purified lectins, and by binding assay using 125i-labeled lectins. among the d-galnac binding lectins, bandeiraea simplicifolia-i, dolichos biflorus, phaseolus vulgaris and glycine max were highly specific for the amastigotes, while that from maclura aurantiaca selectively agglutinated prom ...19863709546
the experimental transmission of leishmania mexicana amazonensis lainson & shaw, between hamsters by the bite of lutzomyia furcata (mangabeira) 19863726982
isolation of leishmania mexicana amazonensis from the bone marrow in a case of american visceral leishmaniasis.the first documented human case of visceral leishmaniasis caused by l. mexicana amazonensis is reported. leishmania were isolated from bone marrow aspirate material from a typical visceral leishmaniasis patient. further characterization by isoenzyme electrophoresis and by a panel of species- and subspecies-specific monoclonal antibodies established its classification as l. m. amazonensis.19863728794
leishmania mexicana amazonensis infections in 'resistant' inbred mice following removal of the draining lymph node.highly resistant (c57bl/10) and intermediately resistant (dba/2) mice were infected subcutaneously with leishmania mexicana amazonensis in a hind footpad subsequent to removal of the draining popliteal node. these mice developed greatly exacerbated leishmania infections as compared to sham-operated controls or to mice infected in the contralateral footpad. the majority of mice in which the draining lymph nodes were removed prior to infection developed metastases, lost their delayed hypersensitiv ...19863731529
experimental infection of lutzomyia longipalpis fed on a patient with cutaneous leishmaniasis due to leishmania mexicana amazonensis. 19863796279
[note on the relations between vectors of leishmaniasis and forest trees in french guiana].the study of relationships between phlebotomine sandflies and different species of trees, 0 to 1.5 m above ground, was carried out in the french guiana forest. we found that certain forest trees are more propitious than others to the development or maintenance of certain leishmaniasis vectors. lu. umbratilis, vector of leishmania braziliensis guyanensis, represents between 28 and 88% of samples collected on trunks. the association of lu. umbratilis and lu. rorotaensis represents between 58 and 9 ...19863813430
monoclonal antibody affinity purification of a leishmania membrane glycoprotein and its inhibition of leishmania-macrophage binding.specific monoclonal antibody coupled to affi-gel 10 was used to purify a major membrane glycoprotein of leishmania mexicana amazonensis, one of a group of parasitic protozoa that specifically infect mammalian macrophages. immobilized antigen was eluted at a 34% efficiency with buffers at either ph 2.5 or 11 or with mgcl2, but only the antigen eluted under basic conditions could be readsorbed to the immunobeads. sephacryl s-300 gel filtration of the purified antigen gave a single peak of protein ...19863079902
destruction of leishmania mexicana amazonensis amastigotes within macrophages by lysosomotropic amino acid esters.leishmania amastigotes parasitize almost exclusively the mononuclear phagocytes of mammals. the organisms survive and multiply within acidified vacuoles (parasitophorous vacuoles; p.v.) akin to phagolysosomes. certain amino acid esters are known to accumulate in and disrupt lysosomes. we postulated that, since leishmania possess lysosome-like organelles, they may be susceptible to the potentially high ester concentrations attained in the p.v. we report here that l-amino acid esters can rapidly d ...19863950542
cytochemical localization of acid phosphatase in leishmania mexicana amazonensis.acid phosphatase was cytochemically detected at the ultrastructural level in infective and non-infective promastigotes and in amastigotes of the parasitic protozoan leishmania mexicana amazonensis. cerium chloride was used as the capture agent of the phosphate liberated during the hydrolysis of the substrate (na-beta-glycerophosphate). reaction product, indicative of enzyme activity, was seen in the outer face of the plasma membrane of many, but not all, infective and noninfective promastigote f ...19863959150
interleukin-2 production during murine infection by leishmania mexicana amazonensis.highly susceptible balb/c mice, resistant c57b1/6 and their f1 progeny (bdf1) were infected subcutaneously in the foot pad with leishmania mexicana amazonensis. at various times after infection, spleen or draining popliteal lymph node cells were assayed for their capacity to generate interleukin-2 (i1-2) by concanavalin a (cona) stimulation. in both balb/c and c57b1/6 strains there was a transient increase in their capacity to produce i1-2, from the 3rd to the 10th week post-infection. return to ...19863491949
histopathologic changes induced by vaccination in experimental cutaneous leishmaniasis of balb/c mice.highly susceptible balb/c mice became partially resistant to leishmania mexicana amazonensis infection after intravenous immunization with solubilized homologous promastigote antigen. immunized balb/c mice exhibited mixed mononuclear cell reactions, with granulomatous inflammation, collagen deposition, and fibrinoid necrosis at the site of infection. in contrast, naive animals displayed a monomorphic picture composed of largely vacuolated and parasitized macrophages with areas of coagulative nec ...19873495185
infective stages of leishmania in the sandfly vector and some observations on the mechanism of transmission.infective stages of leishmania (leishmania) amazonensis, capable of producing amastigote infections in hamster skin, were shown to be present in the experimentally infected sandfly vector lutzomyia flaviscutellata 15, 25, 40, 49, 70, 96 and 120 hours after the flies had received their infective blood-meal. similarly, infective stages of leishmania (l.) chagasi were demonstrated in the experimentally infected vector lu. longipalpis examined 38, 50, 63, 87, 110, 135, 171 and 221 hours following th ...19873507574
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 ...19872824235
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.19872853814
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 ...19872884839
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 ...19872892370
[cutaneous leishmaniasis caused by leishmania mexicana amazonensis in panama]. 19873423320
tunicamycin-resistant leishmania mexicana amazonensis: expression of virulence associated with an increased activity of n-acetylglucosaminyltransferase and amplification of its presumptive gene.tunicamycin at 10 micrograms/ml inhibits the growth and infectivity of the parasitic protozoan leishmania mexicana amazonensis. tunicamycin-resistant variants of this parasite were produced by gradual acclimatization of cells to increasing concentrations of the drug up to 80 micrograms/ml and a single-step selection of ethyl methanesulfonate-pretreated or differentiating leishmanias with the drug at 10 micrograms/ml. prolonged exposure to the drug increases stability of drug resistance of those ...19872950522
involvement of the macrophage mannose-6-phosphate receptor in the recognition of leishmania mexicana amazonensis.significant differences were found in the ability of resident mouse peritoneal macrophages to ingest amastigote and promastigote forms of leishmania mexicana amazonensis. differences in the association index of the parasites to the macrophages were also found between infective and non-infective promastigotes. evidence was obtained suggesting that the macrophage receptor, which recognizes mannose-6-phosphate-containing units found in lysosomal enzymes, is involved in the association with the macr ...19872958844
kinetoplast dna minicircles: regions of extensive sequence divergence.previous work has shown that the kinetoplast minicircle dna of leishmania species exhibits species-specific sequence divergence and this observation has led to the development of a dna probe-based diagnostic test for leishmaniasis. in the work reported here, we demonstrate that the minicircle is composed of three types of dna sequences with differing specificities reflecting different rates of dna sequence change. a library of cloned fragments of kinetoplast dna (kdna) from leishmania mexicana a ...19873025880
biological and biochemical characterization of tunicamycin-resistant leishmania mexicana: mechanism of drug resistance and virulence.a parasitic protozoan, leishmania mexicana amazonensis, was previously made resistant to tunicamycin (j.a. kink and k.-p. chang, proc. natl. acad. sci. usa 84:1253-1257, 1987). in the present study, six different tunicamycin-resistant variants were biologically and biochemically compared with their parental wild type to further delineate the mechanism of tunicamycin resistance and that of their virulence observed. in contrast to their parental wild type, all tunicamycin-resistant variants were f ...19873036710
macrophage function in patients with american cutaneous leishmaniasis: in vitro cytotoxicity and interleukin-1 production.monocyte-derived blood macrophages of untreated patients with leishmania braziliensis or leishmania mexicana amazonensis infections show anomalies in their nonspecific immune functions. their ability to kill hela cells or to produce interleukin-1 in vitro in response to lipopolysaccharide plus candida albicans is lower than controls indicating that acquired or innate macrophage deficiencies may be involved in the course of the disease.19873305852
from lysosomes to cells, from cells to leishmania: amino acid esters as potential chemotherapeutic agents.amino acid esters can disrupt lysosomes and damage monocytes and certain lymphocyte populations. lysosomal disruption involves ph trapping of the esters, followed by their hydrolysis by as yet unidentified enzymes. accumulation of the more polar amino acids is assumed to cause osmotic lysis of the organelles. we have discovered that certain amino acid esters and amides destroy leishmania mexicana amazonensis amastigotes lodged within macrophages in culture, as well as parasites isolated from mou ...19873331952
the transmission of suprapylarian leishmania by the bite of experimentally infected sand flies (diptera: psychodidae).lutzomyia furcata transmitted leishmania chagasi to a hamster 10 days after being experimentally fed on an infected spleen. an individual female psychodopygus carrerai carrerai that had fed on a hamster lesion caused by leishmania mexicana amazonensis transmitted this parasite 6 days later to another hamster. transmission electron microscopy of this fly's head revealed a small number of degenerate promastigotes in the foregut, but only a few were attached.19873333811
leishmania mexicana: destruction of isolated amastigotes by amino acid esters.amino acid esters can destroy intracellular as well as isolated amastigotes of leishmania mexicana amazonensis. in the present study we examined, using a tetrazolium reduction assay, the toxicity of the esters for amastigotes isolated from mouse lesions. parasite killing by the "prototype" compound l-leucine methyl ester at 1 mm concentration and at ph 7.3 took place within 15-30 min. time-lapse cinematographic observations showed that the amastigotes rounded up and became less phase-dense befor ...19873826487
structural and antigenic characterization of a species- and promastigote-specific leishmania mexicana amazonensis membrane protein.a leishmania mexicana amazonensis promastigote membrane glycoprotein (mr 46,000) expressing the species-specific and promastigote-specific epitope of monoclonal antibody ix 2h7-e10(m-2) has been purified to homogeneity, and studies have been made to determine the minimum peptide fragment that retained antigenic activity. peptide mapping experiments performed with the metabolically labeled or surface radioiodinated protein illustrated its highly folded nature and marked resistance to proteolytic ...19873543130
identification of specific and cross-reactive antigens of leishmania donovani chagasi by human infection sera.cloned leishmania donovani chagasi (ldc) promastigotes were analyzed by sds-page separation and immunoblotting with human infection sera. the patterns of antigen reactivity were compared by using sera from individuals with ldc, leishmania mexicana amazonensis (lma), trypanosoma cruzi, mycobacterium tuberculosis, or mycobacterium leprae infections. sera from individuals with these infections recognized ldc antigens in several m.w. ranges. reactivity was due to recognition of ldc molecules and not ...19873543131
cutaneous leishmaniasis. the defect in t cell influx in balb/c mice.local cellular responses to cutaneous infection with leishmania mexicana amazonensis were examined in susceptible (balb/c) and resistant (c57bl/6) mouse strains by immunocytochemical and electron microscopic studies. infection during the first 8 wk in both animal strains was characterized by progressively enlarging lesions, epidermal thickening and ulceration, and accumulation of eosinophils and ia+ infected macrophages. healing of c57bl/6 mouse lesions began after 12 wk of infection and was ass ...19873546576
leishmania mexicana: distribution of intramembranous particles and filipin sterol complexes in amastigotes and promastigotes.the density and distribution of intramembranous particles was analyzed in freeze fracture replicas of the plasma membrane of amastigotes, and infective as well as noninfective promastigotes of leishmania mexicana amazonensis. the density of intramembranous particles on both protoplasmic and extracellular faces was higher in infective than in noninfective promastigotes and it was lower in amastigotes than in promastigotes. amastigotes purified immediately after tissue homogenization were surround ...19873569471
destruction of leishmania mexicana amazonensis promastigotes by normal human serum.fresh normal human serum was observed to have a lethal effect on leishmania mexicana amazonensis promastigotes obtained from laboratory-bred lutzomyia longipalpis or on promastigotes grown in liquid culture medium, inoculated with the same isolates. heat inactivation abolished the leishmania lytic activity from the sera. resistance of culture promastigotes to lysis by normal human serum was investigated in three isolates of l. m. amazonensis. development of resistance (up to 7%) was found in onl ...19873605505
observations on the parasite leishmania mexicana amazonensis and its natural infection of the sand fly lutzomyia olmeca nociva. 19873607352
fine structure and cytochemistry of the interaction between leishmania mexicana amazonensis and rat neutrophils and eosinophils.the fine structure of the in vivo and in vitro interaction process between promastigote and amastigote forms of leishmania mexicana amazonensis with rat peritoneal neutrophils and eosinophils was studied. for in vivo experiments the parasites were inoculated into the peritoneal cavity and samples were collected after different times. both neutrophils and eosinophils readily ingested and digested the parasites within endocytic vacuoles. attachment of the parasites to the eosinophils induced their ...19873612880
identification of a major 72 kilodalton surface antigen in twelve isolates of leishmania braziliensis braziliensis.the study of the surface antigens of leishmania braziliensis braziliensis revealed a great homogeneity among ten strains isolated from bolivia and two reference strains from brazil and belize. a 72 kda major protein, present in all l. b. braziliensis strains, was recognized by both cutaneous and mucocutaneous human sera, but was not recognized by kala-azar and chagasic sera. no cross-reactive antigens were found among strains of leishmania braziliensis guyanensis, leishmania braziliensis panamen ...19873627165
destruction of leishmania mexicana amazonensis amastigotes by leucine methyl ester: protection by other amino acid esters.l-amino acid esters, such as leucine methyl ester (leu-ome) can destroy intracellular as well as isolated amastigotes of leishmania mexicana amazonensis by a mechanism which may involve ester hydrolysis by parasite enzymes. we show here that several other esters prevented the killing of the amastigotes by leu-ome. destruction of leishmania within macrophages in culture was assessed microscopically and viability of isolated parasites was monitored by reduction of the tetrazolium mtt. the main fea ...19873670898
leishmaniasis in brazil. xxiv. natural flagellate infections of sandflies (diptera: psychodidae) in pará state, with particular reference to the rôle of psychodopygus wellcomei as the vector of leishmania braziliensis braziliensis in the serra dos carajás.between july 1983 and december 1984 natural flagellate infections were found in 114 (1%) of 11,586 female phlebotomine sandflies (diptera: psychodidae) of 21 species. a further 1084 females of 17 other species were not infected. identification of the organisms on a number of occasions confirms the exclusive parasite/vector relationship of leishmania mexicana amazonensis/lutzomyia flaviscutellata and le. braziliensis braziliensis/psychodopygus "wellcomei". undescribed or unidentified leishmania s ...19873686628
detection and enumeration of leishmania in sand flies using agar-based media.an agar plating technique was used to determine the number of amastigotes ingested by lutzomyia longipalpis fed on papules on mesocricetus auratus caused by leishmania mexicana amazonensis and on lesions on mystromys albicaudatus caused by leishmania braziliensis panamensis. the technique involved homogenizing sand flies after bloodfeeding on the infected animals and spreading the homogenate over the surface of agar plates. a great variation in the number of amastigotes ingested by individual sa ...19873688307
effect of temperature on leishmania mexicana amazonensis induced lesions in hamsters. 19873692556
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 ...19872441913
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 ...19882450920
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