Publications

TitleAbstractYear(sorted ascending)
Filter
PMID
Filter
protection against cutaneous leishmaniasis by intranasal vaccination with lipophosphoglycan.we previously showed the opposing effect of systemic and mucosal vaccination with whole leishmania amazonensis antigen (laag). here, the role played by lipophosphoglycan (lpg) as the key disease-promoting component of intramuscular (i.m.) laag and its usefulness as a defined intranasal vaccine was investigated in murine cutaneous leishmaniasis. balb/c mice were twice vaccinated by the i.m. route with 25mug of intact laag or with laag that was pretreated with anti-lpg 3a1-la monoclonal antibody, ...200716814903
leishmania amazonensis: characterization of an ouabain-insensitive na+-atpase activity.we characterized ouabain-insensitive na+-atpase activity present in the plasma membrane of leishmania amazonensis and investigated its possible role in the growth of the parasite. an increase in na+ concentration in the presence of 1mm ouabain, increased the atpase activity with a v(max) of 154.1+/-13.5nmol pi x h(-1) x mg(-1) and a k0.5 of 28.9+/-7.7mm. furosemide and sodium orthovanadate inhibited the na+-stimulated atpase activity with an ic(50) of 270microm and 0.10microm, respectively. furo ...200817825292
leishmania-released nucleoside diphosphate kinase prevents atp-mediated cytolysis of macrophages.leishmania amazonensis was found to release nucleoside diphosphate kinase (ndk)-a stable enzyme capable of decreasing extracellular atp. the release of this enzyme from leishmania results in its progressive accumulation extracellularly as they replicate, peaking at the stationary phase in vitro. the released ndk is immunoprecipitable and constitutes approximately 40% of its total activities and proteins. the retention of a known cytosolic protein by wild type cells and a fluorescent protein by d ...200818242727
the effect of phospholipase a2 from crotalus durissus collilineatus on leishmania (leishmania) amazonensis infection.in this study, the effect of phospholipase a2 (pla2) derived from crotalus durissus collilineatus was evaluated in vitro and in vivo on experimental cutaneous leishmaniasis. the promastigote and amastigote forms treated with pla2 presented increased growth rate. in vivo studies showed that pla2-treated leishmania (leishmania) amazonensis promastigotes increased the size of lesions in balb/c mice, and histopathological analysis showed numerous necrotic regions presenting a higher density of polym ...200818180953
iron acquisition within host cells and the pathogenicity of leishmania.iron is an essential cofactor for several enzymes and metabolic pathways, in both microbes and in their eukaryotic hosts. to avoid toxicity, iron acquisition is tightly regulated. this represents a particular challenge for pathogens that reside within the endocytic pathway of mammalian cells, because endosomes and lysosomes are gradually depleted in iron by host transporters. an important player in this process is nramp1 (slc11a1), a proton efflux pump that translocates fe(2+) and mn(2+) ions fr ...200818070118
increase in nuclear translocation of nuclear transcription factor-kappab following infection of a human schwann cell line with leishmania amazonensis. 200818070200
divergence of trypanothione-dependent tryparedoxin cascade into cytosolic and mitochondrial pathways in arsenite-resistant variants of leishmania amazonensis.evidences are presented in the in vivo study that overexpression of tryparedoxin peroxidases (txnpxs) diverged into cytosolic pathway in arsenite-resistant variant a and mitochondrial pathway in variant a' of leishmania amazonensis is due to the upregulation of the corresponding upstream tryparedoxins (txns) in the cytosol as well as the mitochondrion respectively. evidences are also presented that exposure of l. amazonensis to arsenite in the early hours led to the production of reactive oxygen ...200818083246
n-acetyl-l: -cysteine reduces the parasitism of balb/c mice infected with leishmania amazonensis.leishmania amazonensis infection leads to progressive diseases in a majority of inbred strains of mice. glutathione (gsh) participates in a large number of cellular phenomena and seems to be essential for several immune functions, including host defense during leishmaniasis. in this study, we evaluated the effects of n-acetyl-l: -cysteine (nac), as gsh supplement, on the course of l. amazonensis infection in susceptible balb/c mice. the treatment with nac (200 mg/kg daily) was effective in raisi ...200818094999
leishmania amazonensis: biosynthesis of polyprenols of 9 isoprene units by amastigotes.the isoprenoid metabolic pathway in protozoa of the leishmania genus exhibits distinctive characteristics. these parasites, as well as other members of the trypanosomatidae family, synthesize ergosterol, instead of cholesterol, as the main membrane sterol lipid. leishmania has been shown to utilize leucine, instead of acetate as the main precursor for sterol biosynthesis. while mammalian dolichols are molecules containing 15-23 isoprene units, leishmania amazonensis promastigotes synthesize doli ...200818155196
leishmania spp.: delta-aminolevulinate-inducible neogenesis of porphyria by genetic complementation of incomplete heme biosynthesis pathway.to further develop the leishmania model for porphyria based on their deficiencies in heme biosynthesis, three old world species were doubly transfected as before for leishmania amazonensis with cdnas, encoding the 2nd and 3rd enzymes in the pathway. expression of the transgenes was verified immunologically at the protein level and functionally by uroporphyrin neogenesis that occurs only after exposure of the double-transfectants to delta-aminolevulinate. all species examined were equally deficie ...200818164705
[preliminary evaluation of maggot (diptera: calliphoridae) therapy as a potential treatment for leishmaniasis ulcers].maggot debridement therapy has been widely used for treating a variety of scarred-over soft-tissue wounds. published accounts record several illnesses in which treatment with larval therapy has promoted injury healing in conjunction with infection by bacterial pathogens resistant to conventional antibiotics.200818719732
in vitro sodium nitroprusside-mediated toxicity towards leishmania amazonensis promastigotes and axenic amastigotes.leishmania parasites survive despite exposure to the toxic nitrosative oxidants during phagocytosis by the host cell. in this work, the authors investigated comparatively the resistance of leishmania amazonensis promastigotes and axenic amastigotes to a relatively strong nitrosating agent that acts as a nitric oxide (no) donor, sodium nitroprusside (snp). results demonstrate that snp is able to decrease, in vitro, the number of l. amazonensis promastigotes and axenic amastigotes in a dose-depend ...200818720423
in vitro activities of er-119884 and e5700, two potent squalene synthase inhibitors, against leishmania amazonensis: antiproliferative, biochemical, and ultrastructural effects.er-119884 and e5700, novel arylquinuclidine derivatives developed as cholesterol-lowering agents, were potent in vitro growth inhibitors of both proliferative stages of leishmania amazonensis, the main causative agent of cutaneous leishmaniasis in south america, with the 50% inhibitory concentrations (ic(50)s) being in the low-nanomolar to subnanomolar range. the compounds were very potent noncompetitive inhibitors of native l. amazonensis squalene synthase (sqs), with inhibition constants also ...200818765694
effect of brazilian copaiba oils on leishmania amazonensis.copaiba oil has been used in folk medicine since the 19th century. the use of copaiba oils to treat leishmaniasis is cited in several ethnopharmacological studies. nevertheless, the potential antileishmania of copaiba oils had not been studied.200818775772
role of natural killer cells in modulating dendritic cell responses to leishmania amazonensis infection.the importance of the interaction between natural killer (nk) cells and dendritic cells (dcs) in the expansion of antiviral and antitumor immune responses is well-documented; however, limited information on dc-nk cell interaction during parasitic infections is available. given that some leishmania parasites are known to prevent or suppress dc activation, we developed a dc-nk cell coculture system to examine the role of nk cells in modulating the functions of leishmania-infected dcs. we found tha ...200818794295
in vivo activity of perifosine against leishmania amazonensis.miltefosine has been established as the first oral administration drug against cutaneous and visceral leishmaniasis. other alkyl-phospholipids such as edelfosine have been tested against leishmania showing an in vitro antiparasitic activity. perifosine in vitro activity has been previously demonstrated against different leishmania species including leishmania amazonensis. in this study edelfosine and perifosine were orally administered to balb/c mice at doses of 1 and 2.5 mg/kg/day during 28 day ...200818801328
the putrescine analogue 1,4-diamino-2-butanone affects polyamine synthesis, transport, ultrastructure and intracellular survival in leishmania amazonensis.polyamines are important regulators of growth and differentiation in a variety of cells, including parasitic protozoa. promastigotes of leishmania species have high levels of putrescine and spermidine and their growth can be inhibited by polyamine biosynthesis antagonists. the putrescine analogue 1,4-diamino-2-butanone (dab) is microbicidal against tritrichomonas foetus and trypanosoma cruzi, so we tested its effects on leishmania amazonensis proliferation, viability, organization, putrescine tr ...200818832316
structure-activity relationship of (-) mammea a/bb derivatives against leishmania amazonensis.to study the structure-activity relationship of coumarin (-) mammea a/bb isolated from the ch(2)cl(2) extract of calophyllum brasiliense leaves, we evaluated the antileishmanial activity of natural, synthetic and derivatives of this coumarin, against promastigote and intracellular amastigote forms of leishmania amazonensis, and their cytotoxicity to j774g8 murine macrophages. the derivatives were obtained by hydrogenation and methoxylation reactions. the compound structures were elucidated on th ...200818849135
[comparative study between oral miltefosine and parenteral n-metil glucamine antimoniate for the treatment of experimental leishmaniasis caused leishmania (leishmania) amazonensis].twenty-five mice were infected with leishmania amazonensis and treated with glucamine and oral miltefosine. the criteria used were pad measurements and investigations of amastigotes and cultures after treatment. measurements: miltefosine 2.43 mm and glucamine 3.46 mm (p: 0.05). miltefosine smears and cultures were negative. glucamine produced two positive smears and the cultures were positive (p < 0.05). miltefosine was similar to or better than glucamine.200818853022
immunological characteristics of experimental murine infection with leishmania (leishmania) amazonensis.the murine models of leishmania infection are well-studied and suitable models for studying this disease, which, despite its incidence of nearly 2 million new cases worldwide per year and its prevalence of 12 million cases, has been a somewhat neglected disease. data obtained using such models are important for a better understanding of the disease in humans due to similarities in physiology and the advantage provided by the uniform infection profile within each mouse strain. in this review, we ...200818922635
control of parasitophorous vacuole expansion by lyst/beige restricts the intracellular growth of leishmania amazonensis.the intracellular protozoan leishmania replicates in parasitophorous vacuoles (pv) that share many features with late endosomes/lysosomes. l. amazonensis pvs expand markedly during infections, but the impact of pv size on parasite intracellular survival is still unknown. here we show that host cells infected with l. amazonensis upregulate transcription of lyst/beige, which was previously shown to regulate lysosome size. mutations in lyst/beige caused further pv expansion and enhanced l. amazonen ...200818927622
[sandfly fauna (diptera: psychodidae) in a focus of american cutaneous leishmaniasis on the urban periphery of manaus, state of amazonas].from august 2001 to july 2002, sand flies were collected from the bases of trees and, using cdc and disney traps, from areas surrounding homes and forested areas in the são joão community, on the urban periphery of manaus, state of amazonas. 4,104 specimens belonging to four subtribes, 13 genera and 49 species of the phlebotominae subfamily were collected. the subtribe psychodopygina predominated, with 3,403 (83%) specimens, especially of nyssomyia umbratilis, nyssomyia anduzei, trichophoromyia ...200819009191
active transport of glutamate in leishmania (leishmania) amazonensis.leishmania spp. are the causative agents of leishmaniasis, a complex of diseases with a broad spectrum of clinical manifestations. leishmania (leishmania) amazonensis is a main etiological agent of diffuse cutaneous leishmaniasis. leishmania spp., as other trypanosomatids, possess a metabolism based significantly on the consumption of amino acids. however, the transport of amino acids in these organisms remains poorly understood with few exceptions. glutamate transport is an important biological ...200819017058
leishmanicidal metabolites from cochliobolus sp., an endophytic fungus isolated from piptadenia adiantoides (fabaceae).protozoan parasites belonging to genera leishmania and trypanosoma are the etiological agents of severe neglected tropical diseases (ntds) that cause enormous social and economic impact in many countries of tropical and sub-tropical areas of the world. in our screening program for new drug leads from natural sources, we found that the crude extract of the endophytic fungus cochliobolus sp. (ufmgcb-555) could kill 90% of the amastigote-like forms of leishmania amazonensis and inhibit by 100% ellm ...200819079599
pathogenic role of b cells and antibodies in murine leishmania amazonensis infection.leishmania amazonensis infection, occurring predominantly in central and south america, can manifest itself in several forms, including those of cutaneous and diffuse cutaneous leishmaniasis. the outcome of l. amazonensis infection depends largely on host immune responses to the parasites. while cd4+ t cell activation is a prerequisite for pathogenesis in l. amazonensis-infected mice, the roles of b cells and their antibody production are unclear. in this study, we provide evidence suggesting th ...200817959178
trypanosomatid and fungal glycolipids and sphingolipids as infectivity factors and potential targets for development of new therapeutic strategies.several (glyco)(sphingo)lipids from different human pathogens have been characterized, and frequently many of these molecules are participating in host-pathogen interaction. in leishmania (leishmania) amazonensis, for example, amastigotes present on their surface glycosphingolipids (gsls) with the structure galbeta1-3galalpha, which is recognized by 30 kda receptor of macrophages. furthermore, other leishmania species, such as leishmania (leishmania) major and leishmania (viannia) braziliensis p ...200817976917
flagellar length depends on ldarl-3a gtp/gdp unaltered cycling in leishmania amazonensis.we have shown previously that expression of the gtp-blocked form of the small g protein ldarl-3a/q70l led to a marked shortening of leishmania promastigotes flagella. in contrast, there was no effect with the t30n mutant, thought to represent the gdp-blocked form. however, recent data, obtained with human arf-6, a member of the same family of g proteins, revealed that the corresponding mutant t27n was nucleotide-free and that the gdp-blocked form was the t44n mutant. when expressed in leishmania ...200817889949
effects of cxcl10 on dendritic cell and cd4+ t-cell functions during leishmania amazonensis infection.leishmania amazonensis can cause progressive disease in most inbred strains of mice. we have previously reported that treatment with cxcl10 activates macrophage (mphi) effector function(s) in parasite killing and significantly delays lesion development in susceptible c57bl/6 mice via enhanced gamma interferon (ifn-gamma) and interleukin 12 (il-12) secretion; however, the mechanism underlying this enhanced immunity against l. amazonensis infection remains largely unresolved. in this study, we uti ...200817998308
a leishmania (l.) amazonensis atp diphosphohydrolase isoform and potato apyrase share epitopes: antigenicity and correlation with disease progression.a leishmania (leishmania) amazonensis atp diphosphohydrolase isoform was partially purified from plasma membrane of promastigotes by preparative non-denaturing polyacrylamide gel electrophoresis. sds-page followed by western blots developed with polyclonal anti-potato apyrase antibodies identified diffuse bands of about 58-63 kda, possibly glycosylated forms of this protein. by elisa technique, a significantly higher total igg antibody level against potato apyrase was found in serum from promast ...200818005473
leishmania mexicana amazonensis: plasma membrane adenine nucleotide translocator and chemotaxis.leishmania cannot synthesize purines de novo and rely on their host to furnish these compounds. to accomplish this, they possess multiple purine nucleoside and nucleobase transporters. subcellular fractionation, immunohistochemical localization with anti-adenine nucleotide translocator (ant) antibodies and surface biotinylation show that the mitochondrial ant is also present in the plasma membrane of both promastigotes and amastigotes. leishmania, however, do not appear to rely on this transport ...200818031742
efficacy of the intralesional treatment with chenopodium ambrosioides in the murine infection by leishmania amazonensis.leishmaniasis, caused by protozoan from leishmania genus, is an endemic disease in the tropical and subtropical regions of the world. the chemotherapy to this disease is not always effective and can cause several side effects. chenopodium ambrosioides l. (chenopodiaceae) is used by the native people in the treatment of cutaneous ulcers caused by different species of leishmania. the aim of this study was to investigate the effect of the treatment with a hydroalcoholic crude extract (hce) from the ...200818035510
identification and enzymatic activities of four protein disulfide isomerase (pdi) isoforms of leishmania amazonensis.leishmania parasites primarily infect cells of macrophage lineage and can cause leishmaniasis in the skin, mucosal, and visceral organs, depending on both host- and parasite-derived factors. the protein disulfide isomerases (pdis) are thiol-disulfide oxidoreductases that catalyze the formation, reduction, and isomerization of disulfide bonds of proteins in cells. although four leishmania pdi genes are functionally inferred from homology in the genome sequences, only two of them have been express ...200818058133
a new antifungal and antiprotozoal depside from the andean lichen protousnea poeppigii.extracts from the andean lichens protousnea poeppigii and usnea florida displayed antimicrobial activity against the pathogenic fungi microsporum gypseum, trichophyton mentagrophytes and t. rubrum with mic values between 50 and 100 microg/ml. from the active extracts, four main metabolites were isolated and identified as the new depside, isodivaricatic acid, and the known metabolites 5-propylresorcinol, divaricatinic acid and usnic acid. isodivaricatic acid and divaricatinic acid presented antif ...200818058986
leishmania amazonensis: effects of heat shock on ecto-atpase activity.in this work we demonstrated that promastigotes of leishmania amazonensis exhibit an mg-dependent ecto-atpase activity, which is stimulated by heat shock. the mg-dependent atpase activity of cells grown at 22 and 28 degrees c was 41.0+/-5.2 nmol pi/h x 10(7)cells and 184.2+/-21.0 nmol pi/h x 10(7)cells, respectively. when both promastigotes were pre-incubated at 37 degrees c for 2h, the atpase activity of cells grown at 22 degrees c was increased to 136.4+/-10.6 nmol pi/h x 10(7) whereas that th ...200818295760
early infection with leishmania major restrains pathogenic response to leishmania amazonensis and parasite growth.experimental models of infection with leishmania spp. have provided knowledge of several immunological events involved in the resistance mechanism used by the host to restrain parasite growth. it is well accepted that concomitant immunity exists, and there is some evidence that it would play a major role in long-lasting acquired resistance to infection. in this paper, the resistance to leishmania amazonensis infection in c57bl/6 mice infected with leishmania major was investigated. c57bl/6 mice, ...200818313021
inhibition of in vivo leishmanicidal mechanisms by tempol: nitric oxide down-regulation and oxidant scavenging.tempol (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy) has long been known to protect experimental animals from the injury associated with oxidative and inflammatory conditions. in the latter case, a parallel decrease in tissue protein nitration levels has been observed. protein nitration represents a shift in nitric oxide actions from physiological to pathophysiological and potentially damaging pathways involving its derived oxidants such as nitrogen dioxide and peroxynitrite. in infectious di ...200818313408
leishmania amazonensis: xylitol as inhibitor of macrophage infection and stimulator of macrophage nitric oxide production.xylitol is a sugar alcohol being explored for clinical uses. the aim was to evaluate the effects of xylitol on leishmania amazonensis-infected j774a.1 macrophages. macrophages were infected with l. amazonensis for 3h, washed and incubated with 2.5 or 5.0% xylitol for 24, 48, and 72 h at 37 degrees c. infection indexes for macrophages incubated only in medium were compared to those treated with xylitol. cell viability and nitric oxide production were determined each time. xylitol did not affect l ...200818316079
antimicrobial and antileishmanial xanthones from the stem bark of allanblackia gabonensis (guttiferae).the phytochemical study of stem bark of allanblackia gabonensis has resulted in the isolation and characterisation of one new xanthone derivative, named allanxanthone d, together with 10 known compounds, including 6 xanthones derivatives, allanxanthone a, 1,5-dihydroxyxanthone, 1,7-dihydroxyxanthone and 1,3,6,7-tetrahydroxy-2-(3-methylbut-2-enyl)xanthone, forbexanthone, 6-deoxyisojacareubin, one polyisoprenylated benzophenone, guttiferone f, one flavanol, epicathechin, two phytosterols, beta-sit ...200818322848
biochemical and biophysical properties of a highly active recombinant arginase from leishmania (leishmania) amazonensis and subcellular localization of native enzyme.arginase (l-arginine amidinohydrolase, e.c. 3.5.3.1) is a metalloenzyme that catalyses the hydrolysis of l-arginine to l-ornithine and urea. in leishmania spp., the biological role of the enzyme may be involved in modulating no production upon macrophage infection. previously, we cloned and characterized the arginase gene from leishmania (leishmania) amazonensis. in the present work, we successfully expressed the recombinant enzyme in e. coli and performed biochemical and biophysical characteriz ...200818400316
the leishmania hsp20 is antigenic during natural infections, but, as dna vaccine, it does not protect balb/c mice against experimental l. amazonensis infection.protozoa of the genus leishmania are causative agents of leishmaniasis, an important health problem in both human and veterinary medicine. here, we describe a new heat shock protein (hsp) in leishmania, belonging to the small hsp (shsp) family in kinetoplastids. the protein is highly conserved in different leishmania species, showing instead significant divergence with shsp's from other organisms. the humoral response elicited against this protein during leishmania infection has been investigate ...200818401455
antileishmanial activity of azithromycin against leishmania (leishmania) amazonensis, leishmania (viannia) braziliensis, and leishmania (leishmania) chagasi.azithromycin, an azalide antibiotic, is highly concentrated within different phagocytic cells, especially macrophages. the potential antileishmanial activity of azithromycin against three species of leishmania from the new world was assessed using in vitro models. azithromycin decreased viability of promastigote cultures of leishmania (leishmania) amazonensis, leishmania (viannia) braziliensis, and leishmania (leishmania) chagasi as determined by the colorimetric alamar blue assay. in amastigote ...200818458308
interactions with apoptotic but not with necrotic neutrophils increase parasite burden in human macrophages infected with leishmania amazonensis.neutrophils are involved in the initial steps of most responses to pathogens. in the present study, we evaluated the effects of the interaction of apoptotic vs. necrotic human neutrophils on macrophage infection by leishmania amazonensis. phagocytosis of apoptotic, but not viable, neutrophils by leishmania-infected macrophages led to an increase in parasite burden via a mechanism dependent on tgf-beta1 and pge2. conversely, infected macrophages' uptake of necrotic neutrophils induced killing of ...200818483206
characterization of leishmania (leishmania) amazonensis promastigotes resistant to pentamidine.pentamidine is a second-line agent used in the treatment of leishmaniasis and its mode of action and mechanism of resistance is not well understood. it was previously demonstrated that transfection of promastigotes and amastigotes with the abc transporter prp1 gene confers resistance to pentamidine. to further clarify this point, we generated leishmania amazonensis mutants resistant to pentamidine. our results indicated that this abc transporter is not associated with pentamidine resistance in l ...200818511047
down-regulation of dendritic cell signaling pathways by leishmania amazonensis amastigotes.we have previously reported a link between a deficient th1 response to leishmania amazonensis (la) parasites and profound impairments in the cytokine/chemokine network at early stages of the infection. to define the molecular basis of these deficiencies, we focused on early and intracellular events in la-infected dendritic cells (dcs) in this study. la amastigote-infected dcs were less mature and less potent antigen-presenting cells (apc) than their promastigote-infected counterparts, as judged ...200818538399
upgrading the flow-cytometric analysis of anti-leishmania immunoglobulins for the diagnosis of american tegumentary leishmaniasis.we have previously described a flow cytometry-based assay to detect anti-live leishmania (viania) braziliensis promastigote antibodies (fc-alpa) with prominent performance of fc-alpa to diagnosis american tegumentary leishmaniasis (atl). however, the laboriousness to work with live parasites represented the major drawback for using fc-alpa in routine clinical laboratory. herein, we have presented an upgraded technology using fixed leishmania (leishmania) amazonensis promastigotes as antigen (fc- ...200818538785
distinct mitochondrial hsp70 homologues conserved in various leishmania species suggest novel biological functions.we report the identification of two distinct homologues of the 70-kda mitochondrial heat shock protein (mthsp70) from leishmania chagasi/leishmania infantum (lc2.1 and lc2.2). in leishmania species, multiple genes encoding lc2.2 are present whilst single genes encode lc2.1. strikingly, genes encoding lc2.1-like proteins are absent from trypanosoma species. lc2.2 is characterized by a poly-glutamine rich c-terminus, absent from lc2.1 or mthsp70 homologues outside the trypanosomatids. lc2.1 displa ...200818541316
tamoxifen is effective in the treatment of leishmania amazonensis infections in mice.chemotherapy is still a critical issue in the management of leishmaniasis. until recently, pentavalent antimonials, amphotericin b or pentamidine compounded the classical arsenal of treatment. all these drugs are toxic and have to be administered by the parenteral route. tamoxifen has been used as an antiestrogen in the treatment and prevention of breast cancer for many years. its safety and pharmacological profiles are well established in humans. we have shown that tamoxifen is active as an ant ...200818545685
serological reactivity of different antigenic preparations of leishmania (leishmania) amazonensis and the leishmania braziliensis complex.total antigen from leishmania (leishmania) amazonensis and isolates from the leishmania braziliensis complex, along with their respective antigenic fractions obtained by affinity chromatography on concanavalin-a-sepharose and jacalin-agarose columns evaluated using immunoenzymatic elisa assay. for this, serum samples from 229 patients were used, grouped as american tegmental leishmaniasis (n masculine=58), visceral leishmaniasis (n masculine=28), chagas disease (n masculine=49), malaria (n mascu ...200818545832
the use of natural product scaffolds as leads in the search for trypanothione reductase inhibitors.twenty-three heterocyclic compounds were evaluated for their potential as trypanothione reductase inhibitors. as a result, the harmaline, 10-thiaisoalloxazine, and aspidospermine frameworks were identified as the basis of inhibitors of trypanosoma cruzi trypanothione reductase. two new compounds showed moderately strong, linear competitive inhibition, namely n,n-dimethyl-n-[3-(7-methoxy-1-methyl-3,4-dihydro-9h-beta-carbolin-9-yl)propyl]amine (15) and 1,3-bis[3-(dimethylamino)propyl]-1,5-dihydro- ...200818558492
effect of mesoionic 4-phenyl-5-(cinnamoyl)-1,3,4-thiadiazolium-2-phenylamine chloride derivative salts on the activities of the nitric oxide synthase and arginase of leishmania amazonensis.l-arginine is involved in the production of both nitric oxide (no), mediated by nitric oxide synthase (nos) and l-ornithine, by arginase activity. it is generally accepted that no regulation occurs mainly at the transcriptional level of nos. in a previous work we purported that there is evidence that leishmania sp. can produce no from l-arginine. an arginase activity in its gene sequence has also been reported in leishmania parasites. in a search for intracellular targets as potential antileishm ...200818569335
leishmania amazonensis infection may affect the ability of the host macrophage to be activated by altering their outward potassium currents.understanding the impact of intracellular pathogens on the behaviour of their host cells is key to designing new interventions. we are interested in how leishmania alters the electrical functioning of the plasma membrane of the macrophage it infects. the specific question addressed here is whether leishmania amazonensis infection alters the macrophage's outward currents and what the consequences of such changes might be. using the whole cell configuration of the patch clamp technique, we show th ...200818571651
efficacy of pentavalent antimony, amphotericin b, and miltefosine in leishmania amazonensis-infected macrophages under normoxic and hypoxic conditions.recently, our group demonstrated that mouse lesions infected with leishmania amazonensis are hypoxic. evidence indicates the negative impact of hypoxia on the efficacy of a variety of chemotherapeutic agents against tumors, fungi, bacteria, and malaria parasites. in the present study, comparison of the effect of antileishmanial drugs on l. amazonensis-infected macrophages under normoxic and hypoxic conditions was performed. we compared the effect of 5% oxygen tension with a tension of 21% oxygen ...200818576874
leishmania (leishmania) amazonensis: experimental cutaneous leishmaniasis associated with systemic amyloidosis in mice.we infected swiss and c57bl/6 female mice in the left hind footpad with 10(4)leishmania (l.) amazonensis promastigotes in stationary phase. the macroscopic examination showed a nodular non-ulcerated lesion at the site of inoculation and hepatic and spleenic enlargement. histopathologically, the primary lesion showed an extensive liquefactive necrosis and inflammatory infiltrate, mainly consisting of macrophages filled with amastigotes, and rare lymphocytes. the inflammatory reaction in liver, sp ...200818601926
synthesis and preliminary evaluation of new ursolic and oleanolic acids derivatives as antileishmanial agents.a series of new ursolic and oleanolic acids derivatives was synthesized via ursolic or oleanolic acids, previously extracted from south american ilex species. these new compounds were tested for in vitro antiparasitic activity on leishmania amazonensis and leishmania infantum strains. some of these compounds showed activity against the promastigote forms of l. amazonensis or l. infantum, with ic(50) ranging from 5 to 12 microm. as expected, most of the compounds showed a significant level of cyt ...200818608757
contrasting human cytokine responses to promastigote whole-cell extract and the leishmania analogue receptor for activated c kinase antigen of l. amazonensis in natural infection versus immunization.it is known that the same antigen can induce different immune responses, depending upon the way that it is presented to the immune system. the objective of this study was to compare cytokine responses of peripheral blood mononuclear cells (pbmc) from cutaneous leishmaniasis patients and subjects immunized with a first-generation candidate vaccine composed of killed leishmania amazonensis promastigotes to a whole-cell promastigote antigen extract (la) and to the recombinant protein lack (leishman ...200818627399
extracellular nucleotide metabolism in leishmania: influence of adenosine in the establishment of infection.leishmaniasis is a parasitic disease with a variety of clinical forms, which are related to the leishmania species involved. in the murine model, leishmania amazonensis causes chronic non-healing lesions in leishmania braziliensis- or leishmania major-resistant mouse strains. in this study, we investigated the involvement of the pathway of extracellular nucleotide hydrolysis, with special focus on the role of extracellular adenosine, in the establishment of leishmania infection. our results show ...200818656412
in vitro and in vivo activity of meglumine antimoniate produced at farmanguinhos-fiocruz, brazil, against leishmania (leishmania) amazonensis, l (l.) chagasi and l (viannia) braziliensis.the leishmanicidal activity of four batches of meglumine antimoniate, produced in farmanguinhos-fiocruz, brazil (tams), was assessed and compared to glucantime-aventis pharma ltda. using the amastigote-like in vitro model, the active concentrations of sb v varied from 10microg/ml to 300microg/ml for l. (l.) chagasi and from 50microg/ml to 300microg/ml for l. (l.) amazonensis, with no statistically significant differences among the four batches of tams and glucantime. the inhibitory concentration ...200818660990
two distinct arsenite-resistant variants of leishmania amazonensis take different routes to achieve resistance as revealed by comparative transcriptomics.genome-wide search for the genes involved in arsenite resistance in two distinct variants a and a' of leishmania amazonensis revealed that the two variants used two different mechanisms to achieve resistance, even though these two variants were derived from the same clone and selected against arsenite under the same conditions. in variant a, the variant with dna amplification, the biochemical pathways for detoxification of oxidative stress, the energy generation system to support the biochemical ...200818674569
antileishmanial activity of aldonamides and n-acyl-diamine derivatives.a number of lipophilic n-acyl-diamines and aldonamides have been synthesized and tested for their in vitro antiproliferative activity against leishmania amazonensis and l. chagasi. ribonamides, having one amino group, displayed good to moderate inhibition of parasite growth. the best result was obtained for compounds 10 and 15 with ic50 against l. chagasi below 5 microm.200818677429
epidemiology of cutaneous leishmaniasis in suriname: a study performed in 2006.cutaneous leishmaniasis (cl) is a widespread disease in suriname caused by leishmania viannia guyanensis. it is argued that other leishmania species are also responsible for cl and that the incidence is increasing. this study aimed to identify the species causing the disease and to estimate the annual detection rate of cl in suriname in 2006. in paramaribo, 152 patients were registered, of whom 33 were tested in two polymerase chain reaction (pcr)-restriction fragment length polymorphism (rflp) ...200818689623
the c-terminal extension of leishmania pifanoi amastigote-specific cysteine proteinase lpcys2: a putative function in macrophage infection.cysteine proteinases have been implicated in many aspects of protozoan parasite pathogenesis. these hydrolases are normally found as zymogens, and some classes in trypanosomatids possess a long c-terminal extension (cte), for which no function has been assigned. in this paper we hypothesize that the cte domain of lpcys2, the abundant lysosomal cysteine proteinase of leishmania pifanoi amastigotes, is involved in host cell infection. confirming previous reports that this peptide is highly immunog ...200818694784
anti-leishmanial and structure-activity relationship of ring substituted 3-phenyl-1-(1,4-di-n-oxide quinoxalin-2-yl)-2-propen-1-one derivatives.a series of ring substituted 3-phenyl-1-(1,4-di-n-oxide quinoxalin-2-yl)-2-propen-1-one derivatives were synthesized and tested for in vitro leishmanicidal activity against amastigotes of leishmania amazonensis in axenical cultures and murine infected macrophages. structure-activity relationships demonstrated the importance of a radical methoxy at position r3', r4' and r5'. (2e)-3-(3,4,5-trimethoxy-phenyl)-1-(3,6,7-trimethyl-1,4-dioxy-quinoxalin-2-yl)-propenone was the most active. cytotoxicity ...200819148416
schwann cells as putative safe host cells for leishmania amazonensis. 200919157949
altered sterol profile induced in leishmania amazonensis by a natural dihydroxymethoxylated chalcone.the effects of the antileishmanial chalcone 2',6'-dihydroxy-4'-methoxychalcone (dmc) on leishmania amazonensis sterol composition and biosynthesis were investigated to obtain information about the mechanism of growth inhibition by dmc on this parasite.200919176591
activation of pi3k/akt signaling has a dominant negative effect on il-12 production by macrophages infected with leishmania amazonensis promastigotes.infection of macrophages with leishmania parasites does not result in the production of il-12. in addition, infection with leishmania suppresses il-12 production elicited by otherwise potent activators of il-12. we provide evidence that engagement of phosphatidyl inositol-3 kinase (pi3k) signaling during leishmania amazonensis infection leads to the prevention of il-12 p70 production at the level of transcription of its p40 subunit in bone marrow derived macrophages (bmdmphi). inhibition of pi3k ...200919186178
cytotoxic, immunosuppressive, trypanocidal and antileishmanial activities of basidiomycota fungi present in atlantic rainforest in brazil.one hundred three basidiomycota fungi representing 84 species and 17 families were collected from different atlantic rainforest in brazil. their basidiomes and fermentation broth extracts were screened in a bioassay panel that included three human cancer cells lines, human peripheral blood mononuclear cells (pbmcs), the enzyme trypanothione reductase (tryr) from trypanosoma cruzi, and amastigote forms of leishmania amazonensis. forty-two extracts representing 21 genera and 35 species presented a ...200919194781
ifn-beta impairs superoxide-dependent parasite killing in human macrophages: evidence for a deleterious role of sod1 in cutaneous leishmaniasis.type i ifns (ifn-alpha/beta) have only recently gained considerable attention as immunomodulators in nonviral infectious diseases. ifn-beta has been shown to protect, in a no-dependent manner, against murine old world leishmaniasis caused by leishmania major, but data in new world leishmaniasis are lacking. we found that ifn-beta dose-dependently increases parasite burden in leishmania amazonensis- as well as leishmania braziliensis-infected human macrophages, independent of endogenous or exogen ...200919201909
incorporation of antigenic gpi-proteins from leishmania amazonensis to membrane mimetic systems: influence of dppc/cholesterol ratio.the reconstitution of membrane proteins into liposomes is a useful tool to prepare antigenic components that induce immunity. we have investigated the influence of the dipalmitoylphosphatidylcholine (dppc)/cholesterol molar ratio on the incorporation of a gpi-protein from leishmania amazonensis on liposomes and langmuir monolayers. the latter system is a well behaved and practical model, for understanding the effect of variables such as surface composition and lipid packing on protein incorporat ...200919223036
trypanosoma cruzi gp63 proteins undergo stage-specific differential posttranslational modification and are important for host cell infection.the protozoan trypanosoma cruzi expresses multiple isoforms of the gp63 family of metalloproteases. polyclonal antiserum against recombinant gp63 of t. cruzi (tcgp63) was used to study tcgp63 expression and localization in this organism. western blot analysis revealed that tcgp63 is 61 kda in epimastigotes, amastigotes, and tissue culture-derived trypomastigotes but 55 kda in metacyclic trypomastigotes. antiserum specific for leishmania amazonensis gp63 specifically reacted with a 55-kda tcgp63 ...200919273559
transcriptional signatures of balb/c mouse macrophages housing multiplying leishmania amazonensis amastigotes.mammal macrophages (mphi) display a wide range of functions which contribute to surveying and maintaining tissue integrity. one such function is phagocytosis, a process known to be subverted by parasites like leishmania (l). indeed, the intracellular development of l. amazonensis amastigote relies on the biogenesis and dynamic remodelling of a phagolysosome, termed the parasitophorous vacuole, primarily within dermal mphi.200919302708
inhibitory activity of limonene against leishmania parasites in vitro and in vivo.limonene is a monoterpene that has antitumoral, antibiotic and antiprotozoal activity. in this study we demonstrate the activity of limonene against leishmania species in vitro and in vivo. limonene killed leishmania amazonensis promastigotes and amastigotes with 50% inhibitory concentrations of 252.0+/-49.0 and 147.0+/-46.0 microm, respectively. limonene was also effective against leishmania major, leishmania braziliensis and leishmania chagasi promastigotes. the treatment of l. amazonensis-inf ...200919321295
hiv aspartyl peptidase inhibitors interfere with cellular proliferation, ultrastructure and macrophage infection of leishmania amazonensis.leishmania is the etiologic agent of leishmanisais, a protozoan disease whose pathogenic events are not well understood. current therapy is suboptimal due to toxicity of the available therapeutic agents and the emergence of drug resistance. compounding these problems is the increase in the number of cases of leishmania-hiv coinfection, due to the overlap between the aids epidemic and leishmaniasis.200919325703
studying taxis in real time using optical tweezers: applications for leishmania amazonensis parasites.beads trapped by an optical tweezers can be used as a force transducer for measuring forces of the same order of magnitude as typical forces induced by flagellar motion. we used an optical tweezers to study chemotaxis by observing the force response of a flagellated microorganism when placed in a gradient of attractive chemical substances. this report shows such observations for leishmania amazonensis, responsible for leishmaniasis, a serious disease. we quantified the movement of this protozoan ...200919345110
effect of oral treatment with pyrazole carbohydrazide derivatives against murine infection by leishmania amazonensis.newly synthesized pyrazole carbohydrazide derivatives with substituents x = br/y = no(2) and x = no(2)/y = cl were independently investigated in the cba mouse model of cutaneous leishmaniasis. animals were infected with leishmania amazonensis and treated two weeks after the parasitic infection with the pyrazole carbohydrazides for 45 days. oral treatment with both compounds controlled evolution of footpad cutaneous lesions and dissemination of parasites to draining lymph nodes. nitric oxide gene ...200919346377
leishmania amazonensis promastigotes induce and are killed by neutrophil extracellular traps.neutrophils are short-lived leukocytes that die by apoptosis, necrosis, and netosis. upon death by netosis, neutrophils release fibrous traps of dna, histones, and granule proteins named neutrophil extracellular traps (nets), which can kill bacteria and fungi. inoculation of the protozoan leishmania into the mammalian skin causes local inflammation with neutrophil recruitment. here, we investigated the release of nets by human neutrophils upon their interaction with leishmania parasites and nets ...200919346483
altered dendritic cell phenotype in response to leishmania amazonensis amastigote infection is mediated by map kinase, erk.initiation of productive immune responses against leishmania depends on the successful transition of dendritic cells (dc) from an immature to a mature phenotype. this process is characterized by high cd40 surface expression as well as interleukin-12 production, which are frequently seen in response to l. major infection. in vivo footpad infection of c3heb/fej mice for 7 days with l. amazonensis promoted an immature cd11c(+) dc phenotype characterized by both significantly low cd40 surface expres ...200919349356
modulation of p2x(7) purinergic receptor in macrophages by leishmania amazonensis and its role in parasite elimination.the purinergic p2x(7) receptor is a membrane protein of leucocytes involved in the clearance of intracellular bacteria such as chlamydia and mycobacterium. in this work, we investigated the role and modulation of macrophage p2x(7)r in intracellular infection with the protozoan parasite leishmania amazonensis. upon infection, isolated murine macrophages displayed enhanced expression of p2x(7)r and were significantly more responsive to extracellular atp (atpe)-induced pore opening, as demonstrated ...200919439191
saliva of laboratory-reared lutzomyia longipalpis exacerbates leishmania (leishmania) amazonensis infection more potently than saliva of wild-caught lutzomyia longipalpis.in order to compare the saliva effect from wild-caught and lab-reared l. longipalpis on the development of experimental cutaneous leishmaniasis, c57bl/6 mice were inoculated subcutaneously into the hind footpads with promastigotes of l. (l.) amazonensis plus salivary gland lysate from wild-caught (sgl-w) and lab-colonized (sgl-c) vectors. lesion sizes were significantly larger in the mice infected with both saliva compared to mice infected with parasites alone; moreover, the lesions caused by pa ...200919454323
activity of physalins purified from physalis angulata in in vitro and in vivo models of cutaneous leishmaniasis.we have previously demonstrated the immunomodulatory effects of physalins, secosteroids purified from physalis angulata. here we investigate the antileishmanial activity of physalins in vitro and in vivo in a model of cutaneous leishmaniasis.200919454526
antiplasmodial and antileishmanial activities of phylloseptin-1, an antimicrobial peptide from the skin secretion of phyllomedusa azurea (amphibia).the development of drug resistance by infectious agents represents a major hindrance for controlling parasitic diseases and has stimulated the search for new compounds. we have previously shown that phylloseptin-1 (ps-1), a cationic peptide from the skin secretion of phyllomedusa azurea, exhibited potent antimicrobial activity. now we evaluate the effect of ps-1 on leishmania amazonensis and plasmodium falciparum. concentrations as low as 0.5 microg/ml of ps-1 exhibited antileishmanial activity ...200919460376
cooperation between apoptotic and viable metacyclics enhances the pathogenesis of leishmaniasis.mimicking mammalian apoptotic cells by exposing phosphatidylserine (ps) is a strategy used by virus and parasitic protozoa to escape host protective inflammatory responses. with leishmania amazonensis (la), apoptotic mimicry is a prerogative of the intramacrophagic amastigote form of the parasite and is modulated by the host. now we show that differently from what happens with amastigotes, promastigotes exposing ps are non-viable, non-infective cells, undergoing apoptotic death. as part of the n ...200919478944
the use of azythromycin and n-methyl glucamine for the treatment of cutaneous leishmaniasis caused by leishmania (leishmania) amazonensis in c57bl6 mice.the first choice treatment for cutaneous leishmaniasis is n-methyl glucamine: it has high toxicity, requires parenteral administration and cure is not always reached. azythromycin showed in vitro action and controversial results in humans with the disease.200919503979
medicinal plants from the yanesha (peru): evaluation of the leishmanicidal and antimalarial activity of selected extracts.ninety-four ethanolic extracts of plants used medicinally by the yanesha, an amazonian peruvian ethnic group, for affections related to leishmaniasis and malaria were screened in vitro against leishmania amazonensis amastigotes and against a plasmodium falciparum chloroquine resistant strain.200919514108
identification of macrosialin (cd68) on the surface of host macrophages as the receptor for the intercellular adhesive molecule (icam-l) of leishmania amazonensis.the intercellular adhesive molecule, icam-l, of leishmania amazonensis is known to block the attachment as well as internalisation of leishmania for infection in host macrophages. we employed monoclonal antibodies (mab) to the surface molecules of a macrophage to block the attachment of icam-l to the macrophage surface and identified that cd68 macrosialin is likely the receptor molecule on the macrophage for icam-l. we then demonstrated physical interaction between icam-l and macrosialin by co-i ...200919540239
comparative study of serologic tests for the diagnosis of asymptomatic visceral leishmaniasis in an endemic area.serologic tests have been widely used for the diagnosis of asymptomatic visceral leishmaniasis. this study evaluated five serologic tests used for the diagnosis of asymptomatic infection: enzyme-linked immunosorbent assay (elisa) using promastigote antigen (elisap), elisa using recombinant k39 (elisa rk39), and k26 (elisa rk26) antigens, an indirect immunofluorescence test using leishmania (leishmania) amazonensis promastigote antigen (iift), and an immunochromatographic test using rk39 antigen ...200919556562
comparison of serological and parasitological methods for cutaneous leishmaniasis diagnosis in the state of paraná, brazil.we evaluated the effectiveness of serological and parasitological methods for cutaneous leishmaniasis (cl) diagnosis in patients from the central region of paraná state, southern brazil. five groups were compared: clinical diagnosis, parasitological diagnosis, communicants, inhabitants of a non-endemic area and carriers of other etiologies. two antigens were prepared from promastigotes of leishmania (viannia) braziliensis and leishmania (leishmania) amazonensis for indirect immunofluorescence as ...200919578630
leishmania amazonensis growth inhibitors: biological and theoretical features of sulfonamide 4-methoxychalcone derivatives.current drugs for treating leishmaniasis are still associated with significant toxicity and failure rates. thus, new effective and less toxic antileishmanial agents are still in need. herein, we tested a series of sulfonamide 4-methoxychalcone derivatives against l. amazonensis promastigote and amastigote forms to identify its antileishmanial profile against this species compared to l. braziliensis. in addition, we used molecular modeling tools to determine stereoelectronic features that may lea ...200919629593
ta'ta', huayani: perception of leishmaniasis and evaluation of medicinal plants used by the chayahuita in peru. part ii.a knowledge attitude and practice study centred on leishmaniasis and its treatment was performed among the chayahuita, an amazonian peruvian ethnic group living in an endemic area. this study documents traditional chayahuita plant's use and disease concepts. also, activity of some medicinal plants used by the chayahuita is highlighted and discussed.200919631728
evaluation of leishmania species reactivity in human serologic diagnosis of leishmaniasis.the sensitivities and specificities of igg-elisa and igg flow cytometry based techniques using different leishmania species were determined using sera collected from 40 cutaneous or visceral leishmaniasis patients. the flow cytometry technique, using promastigote parasite forms, performed better than total soluble extract igg-elisa. at the species level, the use of leishmania amazonensis and leishmania major as antigens in enzyme linked immunosorbent assay (elisa) decreased the overall sensitivi ...200919635870
in vitro activity of the essential oil of cymbopogon citratus and its major component (citral) on leishmania amazonensis.leishmaniasis causes considerable mortality throughout the world, affecting more than 12 million people. cymbopogon citratus (dc) stapf, family poaceae, is a widely used herb in tropical countries and is also known as a source of ethnomedicines. in this study, the inhibitory effect and the morphological and ultrastructural alterations on leishmania amazonensis by the essential oil (eo) of c. citratus and its main constituent, citral, were evaluated. the results showed that the antiproliferative ...200919669793
synthesis, characterization and evaluation of antileishmanial activity of copper(ii) with fluorinated α-hydroxycarboxylate ligands.in this study, cu(ii) complexes with fluorinated ligands were produced aiming at the development of new, less toxic antileishmanial metallodrugs. complexes of the general formula cul2 (l = lactate, trifluorolactate, 2-hydroxyisobutyrate, trifluoro-2-hydroxyisobutyrate) were synthesized in methanolic medium, purified by crystallization and characterized by elemental analysis and electronic and infrared spectroscopies. in vitro experiments with leishmania amazonensis promastigotes showed that the ...200919680603
[identification of leishmania species isolated in human cases in mato grosso do sul, by means of the polymerase chain reaction].leishmaniases are endemic zoonoses in the state of mato grosso do sul. their etiological agents in this region of brazil are leishmania (leishmania) chagasi, leishmania (leishmania) amazonensis and leishmania (viannia) braziliensis. the polymerase chain reaction (pcr) is a tool with high specificity and sensitivity for identifying leishmania species. this study examined 39 cryopreserved isolates of leishmania that had been collected by bone marrow aspiration and/or lesion biopsy, depending on th ...200919684979
increase of nk cells and proinflammatory monocytes are associated with the clinical improvement of diffuse cutaneous leishmaniasis after immunochemotherapy with bcg/leishmania antigens.diffuse cutaneous leishmaniasis (dcl) is characterized by disseminated lesions and the absence of a specific cellular immune response. here, the immunochemotherapy outcome of a patient with dcl from amazonian brazil infected with leishmania (leishmania) amazonensis is presented. after several unsuccessful chemotherapy treatment regimens and many relapses, a monthly immunotherapy scheme of l. amazonensis ph8 plus l. (viannia) braziliensis m2903 monovalent vaccines associated with bacillus calmett ...200919706899
nf-kappab-mediated repression of inos expression in leishmania amazonensis macrophage infection.host invasion by pathogens is frequently associated with the activation of nuclear factor kappab (nf-kappab), which modulates the expression of genes involved in the immunological response of the host. however, pathogens may also subvert these mechanisms to secure their survival. we describe the effect of leishmania amazonensis infection on nf-kappab transcriptional factor activation in macrophages and the subsequent reduction in inducible nitric oxide synthase (inos) expression. l. amazonensis ...200919712696
a novel organotellurium compound (rt-01) as a new antileishmanial agent.leishmaniasis is a neglected disease and endemic in developing countries. a lack of adequate and definitive chemotherapeutic agents to fight against this infection has led to the investigation of numerous compounds. the aim of this study was to investigate the effect of rt-01, an organotellurane compound presenting biological activities, in 2 experimental systems against leishmania amazonensis. the in vitro system consisted of promastigotes and amastigotes forms of the parasite, and the in vivo ...200919724693
in vitro and in vivo antitrypanosomatid activity of 5-nitroindazoles.previously, we have identified a series of 5-nitroindazoles with good antiprotozoal activities, against trypanosoma cruzi epimastigotes and trichomonas vaginalis. most of them have shown very low unspecific toxicity on macrophage cell lines. in the present work, we assayed these compounds on t. cruzi bloodstream trypomastigotes and leishmania promastigotes (leishmania amazonensis, leishmania braziliensis and leishmania infantum). derivatives 1, 2, 7 and 8 displayed remarkable trypanocidal activi ...200918706738
oral metabolism and efficacy of kalanchoe pinnata flavonoids in a murine model of cutaneous leishmaniasis.leishmaniasis is a parasitic disease that threatens 350 million people worldwide. in a search for new antileishmanial drugs, the in vitro activity of flavonoids from kalanchoe pinnata (crassulaceae) was previously demonstrated in infected cells. in order to demonstrate the safety and oral activity of k. pinnata, flavonoids were evaluated in vivo in a murine model of cutaneous leishmaniasis. daily oral doses of quercetin 3-o-alpha-l-arabinopyranosyl (1-->2)-alpha-l-rhamnopyranoside, quercetin 3-o ...200919085683
antigenic, microbicidal and antiparasitic properties of an l-amino acid oxidase isolated from bothrops jararaca snake venom.venoms from the bee apis mellifera, the caterpillar lonomia achelous, the spiders lycosa sp. and phoneutria nigriventer, the scorpions tityus bahiensis and tityus serrulatus, and the snakes bothrops alternatus, bothrops jararaca, bothrops jararacussu, bothrops moojeni, bothrops neuwiedi, crotalus durissus terrificus, and lachesis muta were assayed (800mug/ml) for activity against staphylococcus aureus. venoms from b. jararaca and b. jararacussu showed the highest s. aureus growth inhibition and ...200919101583
ivermectin-derived leishmanicidal compounds.in the present study a family of macrocyclic and acyclic analogues as well as seco-analogues of avermectins were prepared from commercial ivermectin (ivm) and their antileishmanial activity assayed against axenic promastigote and intracellular amastigote forms of leishmania amazonensis. contrarily to the filaricidal activity, the leishmanicidal potentiality of avermectin analogues does not appear to depend on the integrity of the non-conjugated delta(3,4)-hexahydrobenzofuran moiety. conjugated d ...200919114308
cratp as a new inhibitor of ecto-atpases of trypanosomatids.trypanosomatid protozoa include heteroxenic species some of them pathogenic for men, animals and plants. parasite membrane contains ecto-enzymes whose active sites face the external medium rather than the cytoplasm. herpetomonas sp. displayed a mg2+-dependent ecto-atpase activity, a mg-independent ecto-adpase and an ecto-phosphatase activity. both, the ecto-adpase and phosphatase activities were insensitive to cratp (chromium(iii) adenosine 5'-triphosphate complex). ecto-atpase activity was reve ...200919126268
Refresh
firstprev
12345678910...
nextlast
Displaying items 701 - 800 of 1455