Publications

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 ...	1985	4020925
natural hosts of leishmania mexicana amazonensis lainson and shaw, 1972 (kinetoplastida: trypanosomatidae) in french guiana.		1985	4035728
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 ...	1985	4039899
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 ...	1985	4058483
[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, ...	1985	4066323
[effect of sex hormones on experimental infections induced by a strain of leishmania mexicana amazonensis from venezuela].		1985	4095406
the activity of plumbagin and other electron carriers against leishmania donovani and leishmania mexicana amazonensis.		1985	3834847
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.	1985	3837172
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 ...	1985	3855437
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 ...	1985	3872189
[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 ...	1985	3936605
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 ...	1984	6328296
formation of (1----2)-linked beta-d-mannopyranan by leishmania mexicana amazonensis: relationship with certain crithidia and herpetomonas species.		1984	6491853
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.	1984	6507735
[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].		1984	6533750
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 ...	1984	6592587
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 ...	1984	6691411
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 ...	1983	6832281
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 ...	1983	6882054
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 ...	1983	6617803
isolation and purification of amastigotes of leishmania mexicana amazonensis by a gradient of metrizamide.		1983	6631632
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 ...	1983	6665830
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 ...	1983	6359907
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 ...	1983	6196227
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 ...	1983	6304225
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 ...	1983	6316234
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 ...	1982	6753942
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 ...	1982	6961414
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 ...	1982	7057140
effect of pentamidine isethionate on the ultrastructure and morphology of leishmania mexicana amazonensis in vitro.		1982	7082077
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 ...	1982	7177168
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 ...	1981	6795770
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 ...	1981	6950404
infection of mouse macrophages in vitro by sandfly-derived promastigotes of leishmania mexicana amazonensis.		1981	7324121
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 ...	1981	7324127
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 ...	1981	7324128
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 ...	1981	7324129
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 ...	1981	7324540
accumulation of [125sb]sodium stibogluconate by leishmania mexicana amazonensis and leishmania donovani in vitro.		1981	6108831
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 ...	1981	6112485
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 ...	1980	7385303
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.	1980	7403880
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 ...	1980	7218117
isolation of an enriched plasma membrane-subpellicular microtubule fraction of leishmania mexicana amazonensis.		1980	7231156
isolation of the intracellular stages of leishmania mexicana amazonensis using cellulose column.		1978	736664
[dissemination of leishmania mexicana amazonensis by intracardiac inoculation by pretreatment with gastric mucin (author's transl)].		1978	757721
[new observations upon genital lesions caused by leishmania mexicana amazonensis (author's transl)].		1978	575597
the colonization of lutzomyia flaviscutellata (diptera: psychodidae), a vector of leishmania mexicana amazonensis in brazil.		1977	609078
leishmania in phlebotomid sandflies. iv. the transmission of leishmania mexicana amazonensis to hamsters by the bite of experimentally infected lutzomyia longipalpis.		1977	15270
leishmaniasis in brazil: x. some observations of intradermal reactions to different trypanosomatid antigens of patients suffering from cutaneous and mucocutaneous leishmaniasis.	in spite of the difficulty of antigen standardization, paired intradermal skin tests demonstrated qualitative differences between leishmanin and in vitro exo-antigen. some of these differences may be due to the destruction of certain antigens by phenol, while others seem to reflect basic antigenic differences. leishmania mexicana amazonensis in vitro exo-antigen produced immediate anaphylactic reponses in 74.4% of the patients with parasitologically proven cutaneous leishmaniasis. although more ...	1975	52214
leishmania in phlebotomid sandflies. iii. the ultrastructure of leishmania mexicana amazonensis in the midgut and pharynx of lutzomyia longipalpis.		1975	240164
letter: further evidence of the rôle of lutzomyia flaviscutellata (mangabeira) as the vector of leishmania mexicana amazonensis in brazil.		1973	4785465
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).		1972	4647642
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 ...	0	24838145
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 ...	0	24037188