Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| biochemical characterization of serine transport in leishmania (leishmania) amazonensis. | in addition to its role as a protein component in leishmania, serine is also a precursor for the synthesis of both phosphatidylserine, which is a membrane molecule involved in parasite invasion and inactivation of macrophages, and sphingolipids, which are necessary for leishmania to differentiate into its infective forms. we have characterized serine uptake in both promastigote and amastigote forms of leishmania (leishmania) amazonensis. in promastigotes, kinetic data show a single, saturable tr ... | 2009 | 19041672 |
| photodynamic vaccination of hamsters with inducible suicidal mutants of leishmania amazonensis elicits immunity against visceral leishmaniasis. | leishmania, naturally residing in the phagolysosomes of macrophages, is a suitable carrier for vaccine delivery. genetic complementation of these trypanosomatid protozoa to partially rectify their defective heme-biosynthesis renders them inducible with delta-aminolevulinate to develop porphyria for selective photolysis, leaving infected host cells unscathed. delivery of released "vaccines" to antigen-presenting cells is thus expected to enhance immune response, while their self-destruction prese ... | 2009 | 19053149 |
| dna and heparin chaperone the refolding of purified recombinant replication protein a subunit 1 from leishmania amazonensis. | replication protein a (rpa) is a single-stranded dna-binding protein that has been implicated in dna metabolism and telomere maintenance. subunit 1 of rpa from leishmania amazonensis (larpa-1) has previously been affinity-purified on a column containing a g-rich telomeric dna. larpa-1 binds and co-localizes with parasite telomeres in vivo. here we describe the purification and characterization of native recombinant larpa-1 (rlarpa-1). the protein was initially re-solubilized from inclusion bodie ... | 2009 | 19056467 |
| induction of autophagy correlates with increased parasite load of leishmania amazonensis in balb/c but not c57bl/6 macrophages. | we investigated the role of autophagy in infection of macrophages by leishmania amazonensis. induction of autophagy by ifn-gamma or starvation increased intracellular parasite load and the percentages of infected macrophages from balb/c but not from c57bl/6 mice. in contrast, starvation did not affect the replication of either leishmania major or trypanosoma cruzi in balb/c macrophages. in balb/c macrophages, starvation resulted in increased monodansylcadaverine staining and in the appearance of ... | 2009 | 19070676 |
| membrane binding requirements for the cytolytic activity of leishmania amazonensis leishporin. | to lyse cells, some pore-forming proteins need to bind to receptors on their targets. studying the binding requirements of leishmania amazonensis leishporin, we have shown that protease-treated erythrocytes are as sensitive to leishporin-mediated lysis as untreated cells, indicating that protein receptors are dispensable. similarly, carbohydrate receptors do not seem to be needed, since several sugars do not inhibit leishporin-mediated hemolysis. conversely, dipalmitoylphosphatidylcholine (dppc) ... | 2009 | 19737559 |
| lipid microspheres loaded with antigenic membrane proteins of the leishmania amazonensis as a potential biotechnology application. | lipid microspheres (lm) are excellent drug delivery or vaccines adjuvant systems and are relatively stable. the aim of this work is to develop and characterize a system that is able to encapsulate and present antigenic membrane proteins from leishmania amazonensis. membrane proteins are important for vaccine's formulation because these proteins come in contact with the host cell first, triggering the cell mediated immune response. this is a useful tool to avoid or inactivate the parasite invasio ... | 2009 | 19747691 |
| effects of salivary gland homogenate from wild-caught and laboratory-reared lutzomyia longipalpis on the evolution and immunomodulation of leishmania (leishmania) amazonensis infection. | we investigated the effects of lutzomyia longipalpis salivary glands homogenate of wild-caught and laboratory-reared vectors on the lesion evolution and immunomodulation of the infection caused by leishmania (leishmania) amazonensis. to compare the effect of both salivary glands homogenate (sgh), c57bl/6 mice were inoculated subcutaneously into the hind footpads or into the ear dermis with 10(6) promastigotes in the presence or not of sgh from wild-caught and laboratory-colonized sand flies. com ... | 2009 | 19751274 |
| bioactivity of flavonoids isolated from lychnophora markgravii against leishmania amazonensis amastigotes. | the bioactivity of the flavonoids pinostrobin (1), pinocembrin (2), tectochrysin (3), galangin 3-methyl ether (4), and tiliroside (5) isolated from lychnophora markgravii aerial parts was investigated in vitro against amastigote stages of leishmania amazonensis. the compounds were isolated by several chromatographic techniques and their chemical structures were established by esi-ms and nmr spectroscopic data. the flavonoids 1 and 3 were the most active compounds; they markedly reduced the viabi ... | 2009 | 19791501 |
| separation of leishmania-infected macrophages by step-splitt fractionation. | after a primary infection protocol of macrophages with leishmania amazonensis, the percentage of infection drops as infection progresses and the uninfected population of macrophages mask the effects of infection for electrophysiological studies. in order to increase or maintain the infection percentage, we introduce an enrichment process after primary infection, which increases the possibility of following the infection longer times than any known process. a membraneless separation technique, st ... | 2009 | 19800303 |
| antileishmanial activity of 1,3,4-thiadiazolium-2-aminide in mice infected with leishmania amazonensis. | the efficacy of two mesoionic derivatives (mi-h-h and mi-4-och(3)) was evaluated in cba/j mice infected with leishmania amazonensis. treatment with these compounds demonstrated that the mi-4-och(3) derivative and the reference drug meglumine antimoniate (glucantime) presented significant activity relative to an untreated control. no apparent hepatic or renal toxicity due to these mesoionic compounds was found. | 2009 | 19015338 |
| differential influence of gp63-like molecules in three distinct leptomonas species on the adhesion to insect cells. | parasites belonging to the leptomonas genus have been used as model organisms for studying biochemical, cellular, and genetic processes unique to members of the trypanosomatidae family. in the present study, the cell-associated and extracellular peptidases of three leptomonas species, leptomonas collosoma, leptomonas samueli, and leptomonas wallacei, were assayed and characterized by gelatin-sodium dodecyl sulfate polyacrylamide gel electrophoresis. all parasites released metallopeptidases, wher ... | 2009 | 18830631 |
| aureobasidium-derived soluble branched (1,3-1,6) beta-glucan (sophy beta-glucan) enhances natural killer activity in leishmania amazonensis-infected mice. | the beta-glucans derived from yeast cell walls have been reported for having many immunomodulatory activities in vivo and in vitro. in this study, aureobasidium-derived soluble branched (1,3-1,6) beta-glucan (sophy beta-glucan) was checked for natural killer (nk) activity and for the production of ifn-gamma and il-4 in leishmania amazonensis infection. the main experiment was performed with a group of female c57bl/6 and balb/c mice, orally supplemented with 5% of sophy beta-glucan and infected w ... | 2009 | 19967081 |
| epidemiological study on leishmaniasis in an area of environmental tourism and ecotourism, state of mato grosso do sul, 2006-2007. | the aims of this study were to carry out a serological survey of canine leishmaniasis and identify the phlebotomine fauna in the urban area of bonito, mato grosso do sul. the serological survey was conducted on a sample of 303 dogs, by means of the indirect immunofluorescence test. phlebotomines were captured using automated light traps. the serological survey found that 30% of the dogs were seropositive, both from the center and from all districts of the town. a total of 2,772 specimens of phle ... | 2009 | 19967228 |
| preparation and antileishmanial activity of lipophilic n-alkyl diamines. | we report in this work the preparation and the in vitro antileishmanial activity of a series of long chains n-monoalkylated diamines and two pyridinediamine derivatives. several compounds, tested for their in vitro antiproliferative activity against leishmania amazonensis and leishmania chagasi, displayed a good inhibition of parasite growth, with ic(50) below 10 microm. compounds 10 (n-dodecyl-1,2-ethanediamine), 15 (n-decyl-1,3-propanediamine) and 20 (n-dodecyl-1,4-butanediamine) were 7.3, 2.6 ... | 2009 | 18262385 |
| phlebotomine fauna (diptera: psychodidae) of an american cutaneous leishmaniasis endemic area in the state of mato grosso do sul, brazil. | the occurrence of an outbreak of cutaneous leishmaniasis associated with leishmania (leishmania) amazonensis in the municipality of bela vista, state of mato grosso do sul, brazil, and the absence of information on its vectors in this area led the authors to undertake captures of phlebotomine sand flies, using shannon traps and automatic cdc light traps, in domiciles, forested areas and animal shelters from february 2004-january 2006. a total of 808 specimens belonging to 18 sandfly species have ... | 2009 | 19820827 |
| effect of oral treatment with the essential oil from chenopodium ambrosioides against cutaneous leishmaniasis in balb/c mice, caused by leishmania amazonensis. | the aromatic herb chenopodium ambrosioides is widely known for its antiparasitic activity. the aim of this study was to investigate the antileishmanial effect of chenopodium oil administered by the oral route at different doses and to compare its action to conventional, clinically used drugs. | 2009 | 19887812 |
| analysis of ribosomal rna transcription termination and 3' end processing in leishmania amazonensis. | the control of gene expression in the human parasite leishmania occurs mainly at the post-transcriptional level. nevertheless, basic cell processes such as ribosome biogenesis seem to be conserved. mature ribosomal rnas (rrnas) are synthesized from typical rna polymerase i (pol i) promoters and processed by pathways analogous to other eukaryotes. to further understand pol i transcription control in these parasites, we have analyzed transcription termination and processing of the rdna in leishman ... | 2010 | 19914359 |
| detection of leishmania (leishmania) amazonensis and leishmania (leishmania) infantum chagasi in brazilian bats. | although bats are one of the most abundant mammals in the new world and are present in virtually all ecosystems, including urban and peri-urban environments, few studies have investigated the role of these animals in the epidemiological chain of leishmaniosis. here, we report a study of 683 bats captured in são paulo county (southeastern from brazil), which were screened by serology, parasitologic methods and polymerase chain reaction (pcr) for trypanosomatids. the indirect immunofluorescent ant ... | 2010 | 19939568 |
| leishsmania (leishmania) amazonensis infection: muscular involvement in balb/c and c3h.hen mice. | recent studies have provided some insights into leishsmania (leishmania) amazonensis muscular infection in dogs, although, muscular disease due to leishmaniasis has been poorly documented. the aim of our study was to evaluate involvement of leishmania in muscular infection of two distinct mouse strains (balb/c and c3h.he), with different genetic backgrounds. balb/c mice, susceptible to leishmania infection, showed, at the beginning of infection, a great number of infected macrophages among muscl ... | 2010 | 19944691 |
| cytotoxic and anti-infective sesquiterpenes present in plagiochila disticha (plagiochilaceae) and ambrosia peruviana (asteraceae). | a pharmacological screening of the ethanol extract and fractions of two peruvian medicinal plants, plagiochila disticha and ambrosia peruviana, led to the isolation and characterization of three ent-2,3-secoaromadendrane-type sesquiterpenoids, named plagiochiline a ( 1), i ( 2), and r ( 3), as well as of two pseudoguaianolids, damsin ( 4) and confertin ( 5), which exhibited significant cytotoxic activity against a panel of human tumor cell lines. compounds 1, 4, and 5 were also investigated for ... | 2010 | 19960415 |
| in vitro and in vivo anti-leishmania activity of polysubstituted synthetic chalcones. | the in vitro screening of 43 polysubstituted chalcones against leishmania amazonensis axenic amastigotes, led to the evaluation of 9 of them in a macrophage-infected model with the two other most infectious leishmania species prevalent in peru (l. braziliensis and l. peruviana). the five most active and selective chalcones were studied in vivo, resulting on the identification of two chalcones with high reduction parasite burden percentages. | 2010 | 19962891 |
| anti-leishmanial lindenane sesquiterpenes from hedyosmum angustifolium. | the aim of this work is the isolation of anti-leishmanial compounds from the ethyl acetate extracts of the bark of hedyosmum angustifolium. we have successfully isolated and characterized five sesquiterpenes: one new compound (oxyonoseriolide, 1), one compound isolated for the first time from a natural source (hedyosmone, 2), and three known sesquiterpenes (onoseriolide, 3; chloranthalactone a, 4; and spathulenol, 5) that had not been previously isolated from h. angustifolium. the biological act ... | 2010 | 19830657 |
| changes in macrophage membrane properties during early leishmania amazonensis infection differ from those observed during established infection and are partially explained by phagocytosis. | understanding the impact of intracellular pathogens on the behavior of their host cells is key to designing new interventions. we are interested in how leishmania alters the electrical function of the plasma membrane of the macrophage it infects. the specific question addressed here is the impact of leishmania infection on macrophage membrane properties during the first 12h post-infection. a decrease of 29% in macrophage membrane capacitance at 3h post-infection indicates that the phagolysosome ... | 2010 | 19854174 |
| in vitro sensitivity of leishmania (viannia) braziliensis and leishmania (leishmania) amazonensis brazilian isolates to meglumine antimoniate and amphotericin b. | resistance of leishmania parasites to specific chemotherapy has become a well-documented problem in the indian subcontinent in recent years but only a few studies have focused on the susceptibility of american leishmania isolates. our susceptibility assays to meglumine antimoniate were performed against intracellular amastigotes after standardizing an in vitro model of macrophage infection appropriate for leishmania (viannia) braziliensis isolates. for the determination of promastigote susceptib ... | 2010 | 19874570 |
| antileishmanial activity of furoquinolines and coumarins from helietta apiculata. | the bark infusion of h. apiculata are used to treat wound healing related to cutaneous leishmaniasis and as anti-inflammatory. | 2010 | 19879121 |
| reductions in skin and systemic parasite burdens as a combined effect of topical paromomycin and oral miltefosine treatment of mice experimentally infected with leishmania (leishmania) amazonensis. | this study aimed to investigate the activity of a combination of topical paromomycin gel and oral miltefosine for the treatment of experimental cutaneous leishmaniasis caused by leishmania (leishmania) amazonensis. the efficacy of the combination, evaluated by measuring lesion size and parasite burden in the skin and spleen, was assessed in balb/c mice infected by l. (l.) amazonensis. the miltefosine was administered orally at 10 mg/kg of body weight/day for 10 days, while 10% paromomycin gel wa ... | 2010 | 20713665 |
| screening of medicinal plants against leishmania amazonensis. | leishmaniasis is a widespread tropical infection caused by different species of leishmania protozoa. there is no immunoprophylaxis (vaccination) available for leishmania infections and conventional treatments are unsatisfactory; therefore antileishmanial drugs are urgently needed. natural products are attractive due to their structural diversity. | 2010 | 20731558 |
| antileishmanial activity of a guaianolide from tanacetum parthenium (l.) schultz bip. | leishmaniasis is one of the major infectious diseases affecting the poorest regions of the world. the present study evaluated the antileishmanial activity of a guaianolide purified from the hydroalcoholic extract of aerial parts of tanacetum parthenium (l.) schultz bip. the isolated compound showed activity against the promastigote form of leishmania amazonensis, with 50% inhibition (ic(50)) of cell growth at a concentration of 2.6 μg/ml. for the intracellular amastigote form, this guaianolide r ... | 2010 | 20732450 |
| efficient synthesis of 16 aromatic morita-baylis-hillman adducts: biological evaluation on leishmania amazonensis and leishmania chagasi. | sixteen aromatic morita-baylis-hillman adducts (mbha) 1-16 were efficiently synthesized in a one step morita-baylis-hillman reaction (mbhr) involving commercial aldehydes with methyl acrylate or acrylonitrile (81-100% yields) without the formation of side products on dabco catalysis and at low temperature (0°c). the toxicities of these compounds were assessed against promastigote form of leishmania amazonensis and leishmania chagasi. the low synthetic cost of these mbha, green synthetic protocol ... | 2010 | 20855101 |
| antileishmanial activity of an essential oil from the leaves and flowers of achillea millefolium. | an essential oil was recently extracted from the leaves and flowers of yarrow (achillea millefolium) and tested for in-vitro activity against leishmania amazonensis and murine macrophages (i.e. the j774g8 cell line). the median inhibitory concentration (ic(50)) against l. amazonensis promastigotes was 7.8 μg/ml whereas the survival of amastigotes of this pathogen, within peritoneal murine macrophages, was halved by treatment with the oil at 6.5 μg/ml. the mean value for the median cytotoxic conc ... | 2010 | 20863436 |
| low and high-dose intradermal infection with leishmania major and leishmania amazonensis in c57bl/6 mice. | a model of skin infection with leishmania amazonensis with low doses of parasites is compared to infection with high doses of l. amazonensis and low and high doses of leishmania major. c57bl/6 mice were infected with 10³ or 10(6) parasites in the ear and the outcome of infection was assessed. the appearance of lesions in mice infected with 10³ parasites was delayed compared to mice infected with 10(6) leishmania and parasites were detectable at the infection site before lesions became apparent. ... | 2010 | 20944986 |
| antigenic extracts of leishmania braziliensis and leishmania amazonensis associated with saponin partially protects balb/c mice against leishmania chagasi infection by suppressing il-10 and il-4 production. | this study evaluated two vaccine candidates for their effectiveness in protecting balb/c mice against leishmania chagasi infection. these immunogenic preparations were composed of leishmania amazonensis or leishmania braziliensis antigenic extracts in association with saponin adjuvant. mice were given three subcutaneous doses of one of these vaccine candidates weekly for three weeks and four weeks later challenged with promastigotes of l. chagasi by intravenous injection. we observed that both v ... | 2010 | 20944999 |
| antimicrobial and cytotoxic activities of medicinal plants of the brazilian cerrado, using brazilian cachaça as extractor liquid. | ethnopharmacological importance: many species of plants in the brazilian cerrado (savanna) are widely used in ethnomedicine. however, the safety and effectiveness of medicinal plants used in communities with little or no access to manufactured drugs should be evaluated. | 2010 | 20951786 |
| caffeic acid esters and lignans from piper sanguineispicum. | three new caffeic acid esters (1-3), four new lignans (4-7), and the known compounds (7's)-parabenzlactone (8), dihydrocubebin (9), and justiflorinol (10) have been isolated from leaves of piper sanguineispicum. their structures were determined by spectroscopic methods, including 1d and 2d nmr, hrcims, cd experiments, and chemical methods. compounds 1-10 were assessed for their antileishmanial potential against axenic amastigote forms of leishmania amazonensis. caffeic acid esters 1 and 3 exhibi ... | 2010 | 20954722 |
| biosensors for efficient diagnosis of leishmaniasis: innovations in bioanalytics for a neglected disease. | the need for reliable, fast diagnostics is closely linked to the need for safe, effective treatment of the so-called "neglected" diseases. the list of diseases with no field-adapted diagnostic tools includes leishmaniasis, shigella, typhoid, and bacterial meningitis. leishmaniasis, in particular, is a parasitic disease caused by leishmania spp. transmitted by infected phlebotomine sandfly, which remains a public health concern in developing countries with ca. 12 million people infected and 350 m ... | 2010 | 21043437 |
| antileishmanial sesquiterpenes from the brazilian red alga laurencia dendroidea. | investigation of the bioactive crude extracts from two populations of the red alga laurencia dendroidea from the southeastern brazilian coast led to the identification of five sesquiterpenes: (+)-obtusane ( 1), a triquinane derivative ( 2), (-)-elatol ( 3), obtusol ( 4), and cartilagineol ( 5). an antileishmanial bioassay against leishmania amazonensis was conducted for crude lipophilic extracts and for sesquiterpenes 2, 3, and 4. compounds 3 and 4 displayed in vitro and in vivo leishmanicidal a ... | 2010 | 21058243 |
| characterization of leishmania spp. causing cutaneous leishmaniasis in manaus, amazonas, brazil. | in the state of amazonas, american tegumentary leishmaniasis is endemic and presents a wide spectrum of clinical variability due to the large diversity of circulating species in the region. isolates from patients in manaus and its metropolitan region were characterized using monoclonal antibodies and isoenzymes belonging to four species of the parasite: leishmania (viannia) guyanensis, 73% (153/209); leishmania (viannia) braziliensis, 14% (30/209); leishmania (leishmania) amazonensis, 8% (17/209 ... | 2010 | 21072540 |
| neutrophils reduce the parasite burden in leishmania (leishmania) amazonensis-infected macrophages. | studies on the role of neutrophils in leishmania infection were mainly performed with l. (l) major, whereas less information is available for l. (l) amazonensis. previous results from our laboratory showed a large infiltrate of neutrophils in the site of infection in a mouse strain resistant to l. (l.) amazonensis (c3h/hepas). in contrast, the susceptible strain (balb/c) displayed a predominance of macrophages harboring a high number of amastigotes and very few neutrophils. these findings led us ... | 2010 | 21082032 |
| sand fly captures with disney traps in area of occurrence of leishmania (leishmania) amazonensis in the state of mato grosso do sul, mid-western brazil. | the work was conducted to study phlebotomine fauna (diptera: psychodidae) and aspects of american cutaneous leishmaniasis transmission in a forested area where leishmania (leishmania) amazonensis occurs, situated in the municipality of bela vista, state of mato grosso do sul, brazil. | 2010 | 21085855 |
| in vitro activity of hypnophilin from lentinus strigosus: a potential prototype for chagas disease and leishmaniasis chemotherapy. | hypnophilin and panepoxydone, terpenoids isolated from lentinus strigosus, have significant inhibitory activity on trypanosoma cruzi trypanothione reductase (tr). although they have similar tr inhibitory activity at 10 μg/ml (40.3 μm and 47.6 μm for hypnophilin and panepoxydone, respectively; ~100%), hypnophilin has a slightly greater inhibitory activity (~71%) on t. cruzi amastigote (ama) growth in vitro as well as on in vitro phytohemagglutinin (pha)-induced peripheral blood mononuclear (pbmc) ... | 2010 | 21088803 |
| δ²,³-ivermectin ethyl secoester, a conjugated ivermectin derivative with leishmanicidal activity but without inhibitory effect on mammalian p-type atpases. | looking at a new putative target for the large spectrum antiparasitic drug ivermectin, we recently showed that avermectin-derived drugs are active against promastigote and amastigote forms of leishmania amazonensis at low micromolar concentrations. however, we then reported that at this concentration range ivermectin is also able to inhibit three important mammalian p-type atpases so that unacceptable adverse effects could occur if this drug were used at such high doses therapeutically. the pres ... | 2010 | 21088826 |
| pcr-rflp of ribosomal internal transcribed spacers highlights inter and intra-species variation among leishmania strains native to la paz, bolivia. | human leishmaniasis is highly endemic in bolivia and shows a growing incidence. this report reveals the genetic variability of 35 isolates mainly belonging to leishmania braziliensis and leishmania amazonensis species. among them, 31 were from human patients with different clinical presentations, 3 strains from lutzomya nuneztovari anglesi (the proven vector of l. amazonensis) and 1 strain of a mammal (conepatus chinga). the isolates were analyzed by isoenzyme electrophoresis (mlee) and pcr-rflp ... | 2010 | 21138774 |
| effect of elatol, isolated from red seaweed laurencia dendroidea, on leishmania amazonensis. | in the present study, we investigated the antileishmanial activity of sesquiterpene elatol, the major constituent of the brazilian red seaweed laurencia dendroidea (hudson) j.v. lamouroux, against l. amazonensis. elatol after 72 h of treatment, showed an ic(50) of 4.0 μm and 0.45 μm for promastigote and intracellular amastigote forms of l. amazonensis, respectively. by scanning and transmission electron microscopy, parasites treated with elatol revealed notable changes compared with control cell ... | 2010 | 21139841 |
| leishmania spp. in didelphis albiventris and micoureus paraguayanus (didelphimorphia: didelphidae) of brazil. | leishmaniasis is kept in nature by the participation of several animal species. this study evaluated the presence of leishmania spp. in skin samples of free-ranging marsupials micoureus paraguayanus (n=95) and didelphis albiventris (n=191), captured in morro do diabo state park and in sections of its surrounding forest, in the region of pontal do paranapanema, são paulo state, brazil. the samples were tested for the presence of kdna of leishmania spp. by polymerase chain reaction (pcr) and by re ... | 2010 | 21144664 |
| eco-epidemiology of visceral leishmaniasis in the urban area of paracatu, state of minas gerais, brazil. | the present study was developed in the urban area of paracatu, an endemic city for the american visceral leishmaniasis in brazil. a six-month canine survey was performed with 6295 domiciled dogs in 28 districts in that area and showed that 4.2% of those (267 dogs) were positive for vl by elisa and ifat serum assays. prevalence ratios for canine vl varied between 1.2% and 16.1%, depending on the district under investigation. fifteen dogs - 80% of which were clinically asymptomatic for vl - were s ... | 2010 | 21146311 |
| fusion between leishmania amazonensis and leishmania major parasitophorous vacuoles: live imaging of coinfected macrophages. | protozoan parasites of the genus leishmania alternate between flagellated, elongated extracellular promastigotes found in insect vectors, and round-shaped amastigotes enclosed in phagolysosome-like parasitophorous vacuoles (pvs) of infected mammalian host cells. leishmania amazonensis amastigotes occupy large pvs which may contain many parasites; in contrast, single amastigotes of leishmania major lodge in small, tight pvs, which undergo fission as parasites divide. to determine if pvs of these ... | 2010 | 21151877 |
| leishmania sp. identification by pcr associated with sequencing of target ssu rdna in paraffin-embedded skin samples stored for more than 30 years. | paraffin-embedded samples commonly stored at educational and research institutions constitute tissues banks for follow-up or epidemiological studies; however, the paraffin inclusion process involves the use of substances that can cause dna degradation. in this study, a pcr protocol was applied to identify leishmania strains in 33 paraffin-embedded skin samples of patients with american cutaneous leishmaniasis. dna was obtained by the phenol-chloroform protocol following paraffin removal and then ... | 2010 | 21161272 |
| enhancement of experimental cutaneous leishmaniasis by leishmania molecules is dependent on interleukin-4, serine protease/esterase activity, and parasite and host genetic backgrounds. | most inbred strains of mice, like the balb/c strain, are susceptible to leishmania amazonensis infections and resistant to leishmania braziliensis infections. this parasite-related difference could result from the activity of an l. amazonensis-specific virulence factor. in agreement with this hypothesis, it is shown here that the intravenous injection of balb/c mice with l. amazonensis amastigote extract (lae) but not the l. braziliensis extract confers susceptibility to l. braziliensis infectio ... | 2010 | 21173308 |
| influence of long-term treatment with pravastatin on the survival, evolution of cutaneous lesion and weight of animals infected by leishmania amazonensis. | the high toxicity of current drugs for treatment of leishmaniasis is a major hindrance for controlling the disease. pravastatin is a well-known drug with anti-inflammatory and immunomodulatory properties that may modulate host defense mechanisms against leishmania. we evaluated the influence of prolonged pravastatin treatment on the survival of leishmania amazonensis-infected animals (balb/c, c57bl6 mice and syrian hamsters), including weekly measurement of cutaneous lesions (footpad thickness) ... | 2010 | 21176775 |
| differential microbicidal effects of human histone proteins h2a and h2b on leishmania promastigotes and amastigotes. | recent studies have shown that histone proteins can act as antimicrobial peptides in host defense against extracellular bacteria, fungi, and leishmania promastigotes. in this study, we used human recombinant histone proteins to further study their leishmaniacidal effects and the underlying mechanisms. we found that the histones h2a and h2b (but not h1(0)) could directly and efficiently kill promastigotes of leishmania amazonensis, l. major, l. braziliensis, and l. mexicana in a treatment dose-de ... | 2010 | 21189319 |
| detc induces leishmania parasite killing in human in vitro and murine in vivo models: a promising therapeutic alternative in leishmaniasis. | chemotherapy remains the primary tool for treatment and control of human leishmaniasis. however, currently available drugs present serious problems regarding side-effects, variable efficacy, and cost. affordable and less toxic drugs are urgently needed for leishmaniasis. | 2010 | 21200432 |
| chemistry and biological activity of essential oils from piper claussenianum (piperaceae). | analyses of essential oils obtained from fresh and dried leaves and inflorescences of piper clausenianum were performed using gc-fid, gc-ms and nmr techniques. forty compounds were detected for these four oils with the total of identified constituents ranging from 88.7% for the dried inflorescences to 97.7% for the dried leaves. sesquiterpenes were the main constituents in the volatile fraction from leaves with a high percentage of (e)-nerolidol (up to 83%). however, monoterpenes were identified ... | 2010 | 21213995 |
| in vitro initial immune response against leishmania amazonensis infection is characterized by an increased production of il-10 and il-13. | the initial encounter of leishmania with its host's immune system is important in the outcome of infection. previous studies have shown that pbmcs from healthy volunteers (hv) exposed to leishmania differ in ifn-γ production. we have expanded such observations evaluating the profile and kinetics of cytokines (ifn-γ, il-12p70, il-10, il-13), chemokines (ccl5, ccl3, ccl4, cxcl10), and chemokine receptors (ccr1,ccr5, cxcr3, ccr4) in vitro l. amazonensis-stimulated of hv's pbmcs. hvs were divided in ... | 2010 | 21221476 |
| a deficiency in the b cell response of c57bl/6 mice correlates with loss of macrophage-mediated killing of leishmania amazonensis. | infection of c3heb/fej and c57bl/6 mice with leishmania major stimulates a healing cell-mediated immune response, while leishmania amazonensis infection leads to chronic disease. here we show c3heb/fej mice co-infected with both species of leishmania heal, while co-infected c57bl/6 mice do not. using an in vitro killing assay we determined b cells from infected c57bl/6 mice are ineffective in promoting parasite killing compared with b cells from infected c3heb/fej mice. furthermore, infected c57 ... | 2010 | 20004204 |
| functional characterization of lit1, the leishmania amazonensis ferrous iron transporter. | leishmania amazonensis lit1 was identified based on homology with irt1, a ferrous iron transporter from arabidopsis thaliana. deltalit1l. amazonensis are defective in intracellular replication and lesion formation in vivo, a virulence phenotype attributed to defective intracellular iron acquisition. here we functionally characterize lit1, directly demonstrating that it functions as a ferrous iron membrane transporter from the zip family. conserved residues in the predicted transmembrane domains ... | 2010 | 20025906 |
| synthesis and antileishmanial activity of lipidic amino alcohols. | in this work, a number of lipidic amino alcohols wereas synthesized and evaluated in vitro on cultures of leishmania amazonensis and leishmania chagasi. nine amino alcohols showed inhibition of l. chagasi growth, and seven of them showed inhibition of l. amazonensis with ic(50) below 10 microm. compound 11f was more active than the reference drug amphotericin b against l. chagasi promastigote forms. | 2010 | 20028395 |
| leishmania amazonensis: heme stimulates (na(+)+k(+))atpase activity via phosphatidylinositol-specific phospholipase c/protein kinase c-like (pi-plc/pkc) signaling pathways. | in the present paper we studied the involvement of the phosphatidylinositol-specific plc (pi-plc)/protein kinase c (pkc) pathway in (na(+)+k(+))atpase stimulation by heme in leishmania amazonensis promastigotes. heme stimulated the pkc-like activity with a concentration of 50nm. interestingly, the maximal stimulation of the pkc-like activity promoted by phorbol ester was of the same magnitude promoted by heme. however, the stimulatory effect of heme is completely abolished by et-18-och(3) and u7 ... | 2010 | 20045694 |
| evaluation of antileishmanial activity of eupomatenoid-5, a compound isolated from leaves of piper regnellii var. pallescens. | infection with leishmania spp. causes a disease with multifaceted clinical manifestations in humans. the treatment for leishmaniasis is dependent on a limited range of drugs. here we investigated the antileishmanial activity of eupomatenoid-5, a neolignan isolated from leaves of piper regnellii var. pallescens. we showed that eupomatenoid-5 had a dose-dependent activity during 72h of treatment, exhibiting ic(50) of 9.0microg/ml and 13.0microg/ml for promastigote and axenic amastigote forms, resp ... | 2010 | 20064628 |
| sialic acids in different leishmania sp., its correlation with nitric oxide resistance and host responses. | the presence of different derivatives of sialic acids (sa) on leishmania donovani instigated us to investigate their status on different strains of leishmania sp. causing different forms of the disease. leishmania tropica (k27), leishmania major (jish118) and leishmania mexicana (lv4) responsible for cutaneous, leishmania braziliensis (l280) and leishmania amazonensis (lv81) causing diffuse and leishmania infantum (mon29) responsible for visceral leishmaniasis were included in this study. the st ... | 2010 | 20085901 |
| leishmanicidal activity of himatanthus sucuuba latex against leishmania amazonensis. | himatanthus sucuuba (hsl) latex exhibited a potent leishmanicidal activity against intracellular amastigotes of leishmania amazonensis, a causative agent of cutaneous leishmaniasis. hsl inhibited intracellular amastigote growth in a dose-dependent manner (ic(50)=15.7microg/ml). moreover, hsl increased nitric oxide (no) and tumor nuclear factor-alpha (tnf-alpha) and decreased transforming growth factor-beta (tgf-beta) production in macrophages. as assessed by plasma membrane integrity and mitocho ... | 2010 | 20096374 |
| activation of leishmania (leishmania) amazonensis arginase at low temperature by binuclear mn2+ center formation of the immobilized enzyme on a ni2+ resin. | in leishmania, arginase is responsible for the production of ornithine, a precursor of polyamines required for proliferation of the parasite. in this work, the activation kinetics of immobilized arginase enzyme from l. (l.) amazonensis were studied by varying the concentration of mn2+ applied to the nickel column at 23 degrees c. the intensity of the binding of the enzyme to the ni2+ resin was directly proportional to the concentration of mn2+. conformational changes of the enzyme may occur when ... | 2010 | 20109449 |
| hypoxia modulates phenotype, inflammatory response, and leishmanial infection of human dendritic cells. | development of hypoxic areas occurs during infectious and inflammatory processes and dendritic cells (dcs) are involved in both innate and adaptive immunity in diseased tissues. our group previously reported that macrophages exposed to hypoxia were infected with the intracellular parasite leishmania amazonensis, but showed reduced susceptibility to the parasite. this study shows that although hypoxia did not alter human dc viability, it significantly altered phenotypic and functional characteris ... | 2010 | 20132174 |
| apoptosis and apoptotic mimicry: the leishmania connection. | different death-styles have been described in unicellular organisms. in most cases they evolve with phenotypic features similar to apoptotic death of animal cells, such as phosphatidylserine (ps) exposure, oligonucleosomal dna fragmentation, and loss of mitochondrial transmembrane potential, hinting that similar mechanisms operate in both situations. however, the biochemical pathways underlying death in unicellular organisms are still unclear. host recognition of ps exposed on the surface of uni ... | 2010 | 20140747 |
| iron metabolism in trypanosomatids, and its crucial role in infection. | iron is almost ubiquitous in living organisms due to the utility of its redox chemistry. it is also dangerous as it can catalyse the formation of reactive free radicals - a classical double-edged sword. in this review, we examine the uptake and usage of iron by trypanosomatids and discuss how modulation of host iron metabolism plays an important role in the protective response. trypanosomatids require iron for crucial processes including dna replication, antioxidant defence, mitochondrial respir ... | 2010 | 20152063 |
| a new experimental culture medium for cultivation of leishmania amazonensis: its efficacy for the continuous in vitro growth and differentiation of infective promastigote forms. | parasites from the genus leishmania cause a variety of disease states in humans and other mammals in tropical and subtropical regions, which include cutaneous, mucocutaneous and visceral leishmaniasis. the elaboration of a culture medium for the in vitro cultivation of leishmania spp., which promotes the growth and differentiation of the parasites, is an important tool for diagnosis, biochemical, biological and immunological studies in the genus. herein, we have reported the development of a rap ... | 2010 | 20177905 |
| comparative evaluation of phenol and thimerosal as preservatives for a candidate vaccine against american cutaneous leishmaniasis. | for decades thimerosal has been used as a preservative in the candidate vaccine for cutaneous leishmaniasis, which was developed by mayrink et al. the use of thimerosal in humans has been banned due to its mercury content. this study addresses the standardization of phenol as a new candidate vaccine preservative. we have found that the proteolytic activity was abolished when the test was conducted using the candidate vaccine added to merthiolate (mtvac) as well as to phenol (phvac). the monteneg ... | 2010 | 20209335 |
| an enhanced method for the identification of leishmania spp. using real-time polymerase chain reaction and sequence analysis of the 7sl rna gene region. | the accurate identification of leishmania spp. is important for the treatment of infected patients. molecular methods offer an alternative to time-consuming traditional laboratory techniques for species determination. we redesigned a 7sl rna gene-based polymerase chain reaction and sequence assay for increased species identification. dna extracted from 17 reference strains and 10 cultured clinical isolates was examined. sequence comparison was used successfully to identify organisms to the compl ... | 2010 | 20226334 |
| trypanocidal, leishmanicidal and antifungal potential from marine red alga bostrychia tenella j. agardh (rhodomelaceae, ceramiales). | specimens of the red alga bostrychia tenella j. agardh (rhodomelaceae, ceramiales) were collected from the são paulo coast and submitted to room temperature solvent extraction. the resulting extract was fractionated by partitioning with organic solvent. the n-hexane (bt-h) and dichloromethane (bt-d) fractions showed antiprotozoal potential in biological tests with trypanosoma cruzi and leishmania amazonensis and presented high activity in an antifungal assay with the phytopathogenic fungi clados ... | 2010 | 20236785 |
| leishmania (leishmania) amazonensis infection in mice treated with fty720. | in transplantation, parasite diseases are transmitted from the donor, or appear as de novo infections, or activate from a dormant insource as a consequence of immunosuppression. clinical findings have shown that an intact immune system is crucial to prevent recurrence of leishmania infection. we used balb/c and c57bl/6 mice to evaluate the role of fty720 in leishmaniasis. mice inoculated with leishmania (leishmania) amazonensis were followed over 7 weeks for foot thickness measurements after ini ... | 2010 | 20304196 |
| [phlebotomine fauna (diptera: psychodidae) in a campina reserve in the state of amazonas, and its epidemiological importance]. | in brazil, the largest diversity of phlebotomines is found in the amazon region, particularly in undisturbed terra-firma forest. however, the phlebotomine fauna in other ecosystems of this region is still not well known. | 2010 | 20305974 |
| trypanoside, anti-tuberculosis, leishmanicidal, and cytotoxic activities of tetrahydrobenzothienopyrimidines. | the synthesis of 2-(5,6,7,8-tetrahydro[1]benzothieno[2,3-d]pyrimidin-4-yl)hydrazone-derivatives (btps) and their in vitro evaluation against trypanosoma cruzi trypomastigotes, mycobacterium tuberculosis, leishmania amazonensis axenic amastigotes, and six human cancer cell lines is described. the in vivo activity of the most active and least toxic compounds against t. cruzi and l. amazonensis was also studied. btps constitute a new family of drug leads with potential activity against infectious d ... | 2010 | 20356752 |
| novel arylimidamides for treatment of visceral leishmaniasis. | arylimidamides (aias) represent a new class of molecules that exhibit potent antileishmanial activity (50% inhibitory concentration [ic(50)], <1 microm) against both leishmania donovani axenic amastigotes and intracellular leishmania, the causative agent for human visceral leishmaniasis (vl). a systematic lead discovery program was employed to characterize in vitro and in vivo antileishmanial activities, pharmacokinetics, mutagenicities, and toxicities of two novel aias, db745 and db766. they we ... | 2010 | 20368397 |
| selection and phenotype characterization of potassium antimony tartrate-resistant populations of four new world leishmania species. | in the present study, we selected in vitro populations of leishmania viannia guyanensis, l.v. braziliensis, l. leishmania amazonensis and l.l. infantum chagasi that were resistant to potassium antimony tartrate (sbiii). the resistance index of these populations varied from 4- to 20-fold higher than that of their wild-type counterparts. to evaluate the stability of the resistance phenotype, these four resistant populations were passaged 37 to 47 times in a culture medium without sbiii. no change ... | 2010 | 20372925 |
| antitrypanosomal and antileishmanial activities of novel n-alkyl-(1-phenylsubstituted-beta-carboline)-3-carboxamides. | a series of 1-phenylsubstituted beta-carbolines containing an n-butylcarboxamide group at c-3 of beta-carboline nucleus were synthesized and evaluated in vitro against epimastigote form of trypanosoma cruzi and promastigote form of leishmania amazonensis. among all compounds tested, two derivatives (2b and 2d) presented potent activity against both parasites. the most active derivative 2b showed also the higher selectivity index ratio (si) for l. amazonensis (si=2,084). the effect of other n-alk ... | 2010 | 20382497 |
| the influence of ecto-nucleotidases on leishmania amazonensis infection and immune response in c57b/6 mice. | previous results from our laboratory and from the literature have implicated the expression of ecto-nucleotidases in the establishment of leishmania infection. in the present study we evaluated the correlation between ecto-nucleotidasic activity and the infectivity of l. amazonensis promastigotes that were kept in culture for short or extended numbers of passages, a condition that is known to decrease parasite infectivity. we also analyzed the immune response associated with the infection by the ... | 2010 | 20399737 |
| the leishmania amazonensis trf (ttaggg repeat-binding factor) homologue binds and co-localizes with telomeres. | telomeres are specialized structures at the end of chromosomes essential for maintaining genome stability and cell viability. the importance of telomeric proteins for telomere maintenance has increased our interest in the identification of homologues within the genus leishmania. the mammalian trf1 and trf2 proteins, for example, bind double-stranded telomeres via a myb-like dna-binding domain and are involved with telomere length regulation and chromosome end protection. in addition, trf2 can mo ... | 2010 | 20459667 |
| immunopathological studies of leishmania amazonensis infection in resistant and in susceptible mice. | leishmania amazonensis infection was studied in mice to evaluate the evolution of leishmaniasis. the association of different methods, such as lesion kinetics, limiting dilution analysis, and immunohistochemistry, established different levels of susceptibility and resistance. mice were arranged in 3 groups: susceptible (c57bl/10 and cba), relatively resistant (dba/2), and resistant (c3h.he). the histopathological analysis of primary lesions and draining lymph nodes showed a predominance of eosin ... | 2010 | 20462353 |
| leishmanicidal activity of echinaster (othilia) echinophorus crude extract. | in this study, a methanolic extract from echinaster (othilia) echinophorus was evaluated for activity against leishmania amazonensis. the extract showed activity against the promastigote and amastigote forms with ic50 values of 62.9 and 37.5 microg.ml-1 respectively. this extract showed a moderate toxicity on macrophages from balb/c mice. a dose of 100 mg/kg/day was effective when administered during 15 days by intraperitoneal route to balb/c mice infected experimentally. | 2010 | 20464129 |
| serine proteases of leishmania amazonensis as immunomodulatory and disease-aggravating components of the crude laag vaccine. | we previously demonstrated that intradermal and intramuscular vaccination with leishmania amazonensis promastigote antigens (laag) increases the susceptibility of balb/c mice to cutaneous leishmaniasis. in this study, we investigated the role played by serine and cysteine proteases as disease-promoting components of laag. mice were immunized by the intramuscular route with laag that was pre-treated with a pool of serine or cysteine protease inhibitors (spi and cpi, respectively) prior to infecti ... | 2010 | 20472030 |
| type i ifn receptor regulates neutrophil functions and innate immunity to leishmania parasites. | type i ifns exert diverse effector and regulatory functions in host immunity to viral and nonviral infections; however, the role of endogenous type i ifns in leishmaniasis is unclear. we found that type i ifnr-deficient (ifnar-/-) mice developed attenuated lesions and reduced ag-specific immune responses following infection with leishmania amazonensis parasites. the marked reduction in tissue parasites, even at 3 d in ifnar-/- mice, seemed to be indicative of an enhanced innate immunity. further ... | 2010 | 20483775 |
| characterization of oxidative stress in leishmaniasis-infected or lps-stimulated macrophages using electrochemical impedance spectroscopy. | the physiological changes caused by external stimuli can be employed as parameters to study pathogen infection in cells and the effect of drugs. among analytical methods, impedance is potentially useful to give insight into cellular behavior by studying morphological changes, alterations in the physiological state, production of charged or redox species without interfering with in vitro cellular metabolism and labeling. the present work describes the use of electrochemical impedance spectroscopy ... | 2010 | 20488689 |
| kinetoplastid membrane protein-11 is present in promastigotes and amastigotes of leishmania amazonensis and its surface expression increases during metacyclogenesis. | kinetoplastid membrane protein-11 (kmp-11), a protein present in all kinetoplastid protozoa, is considered a potential candidate for a leishmaniasis vaccine. a suitable leishmaniasis vaccine candidate molecule must be expressed in amastigotes, the infective stage for mammals. however, the expression of kmp-11 in leishmania amastigotes has been a subject of controversy. we evaluated the expression of this molecule in logarithmic and stationary growth phase promastigotes, as well as in amastigotes ... | 2010 | 20512252 |
| flow cytometric screening for anti-leishmanials in a human macrophage cell line. | high-throughput drug screening methods against the intracellular stage of leishmania have been facilitated by the development of in vitro models of infection. the use of cell lines rather than primary cells facilitates these methods. peripheral blood mononuclear cell (pbmc) derived macrophages and thp-1 cells were infected with stationary phase egfp transfected leishmania amazonensis parasites and then treated with anti-leishmanial compounds. drug activity was measured using a flow cytometric ap ... | 2010 | 20540940 |
| complete set of mitochondrial pan-edited mrnas in leishmania mexicana amazonensis lv78. | editing of mrna transcribed from the mitochondrial cryptogenes nd8 (g1), nd9 (g2), g3, g4, nd3 (g5), rps12 (g6) was investigated in leishmania mexicana amazonensis, strain lv78, by amplification of the cdna, cloning and sequencing. for each of these genes, extensively and partially edited transcripts were found to be relatively abundant compared to the respective pre-edited molecules. moreover, the editing patterns observed in a majority of transcripts of each gene were consistent among themselv ... | 2010 | 20546801 |
| vaccination with the leishmania infantum ribosomal proteins induces protection in balb/c mice against leishmania chagasi and leishmania amazonensis challenge. | leishmania chagasi and leishmania amazonensis are the etiologic agents of different clinical forms of human leishmaniasis in south america. in an attempt to select candidate antigens for a vaccine protecting against different leishmania species, the efficacy of vaccination using leishmania ribosomal proteins and saponin as adjuvant was examined in balb/c mice against challenge infection with both parasite species. mice vaccinated with parasite ribosomal proteins purified from leishmania infantum ... | 2010 | 20601076 |
| serine protease activities in leishmania (leishmania) chagasi promastigotes. | the present work reports the isolation, biochemical characterization, and subcellular location of serine proteases from aqueous, detergent soluble, and culture supernatant of leishmania chagasi promastigote extracts, respectively, lcsii, lcsi, and lcsiii. the active enzyme molecular masses of lcsii were about 105, 66, and 60 kda; of lcsi, 60 and 58 kda; and of lcsiii, approximately 76 and 68 kda. optimal ph for the enzymes was 7.0 for lcsi and lcsiii and 8.5 for lcsii, and the optimal temperatur ... | 2010 | 20668879 |
| efficacy of components from leaves of calophyllum brasiliense against leishmania (leishmania) amazonensis. | leishmanicide potential of calophyllum brasiliense leaves on promastigote and amastigote of leishmania (leishmania) amazonensis is evaluated. the ld(50) of dichloromethane extract and hexane fraction for promastigotes was respectively 40 microg/ml and 20 microg/ml. in mouse peritoneal macrophages infected with leishmania amastigotes the infection index decreased respectively 100% and 84.2% in 80 microg/ml and 40 microg/ml concentrations of dichloromethane extract. hexane fraction decreased infec ... | 2010 | 19800777 |
| novel role for the double-stranded rna-activated protein kinase pkr: modulation of macrophage infection by the protozoan parasite leishmania. | the evolution of leishmania infection depends on the balance between microbicidal and suppressor macrophage functions. double-stranded rna (dsrna)-activated protein kinase r (pkr), a classic antiviral protein, is able to regulate a number of signaling pathways and macrophage functions. we investigated the possible role of pkr in the modulation of leishmania infection. our data demonstrated that leishmania amazonensis infection led to pkr activation and increased pkr levels. consistently, in macr ... | 2010 | 19812373 |
| leishmania spp. identification by polymerase chain reaction-restriction fragment length polymorphism analysis and its applications in french guiana. | leishmania (viannia) guyanensis was for many years the only species commonly identified in french guiana, but precise species identifications were quite rare. we describe a new restriction fragment length polymorphism-polymerase chain reaction technique using a 615-bp fragment of the rna polymerase ii gene and 2 restriction enzymes, tspri and hgai. seven reference strains (leishmania (leishmania) amazonensis, leishmania (viannia) lainsoni, leishmania (viannia) braziliensis, l. (v.) guyanensis, l ... | 2010 | 19782495 |
| partial protective responses induced by a recombinant cysteine proteinase from leishmania (leishmania) amazonensis in a murine model of cutaneous leishmaniasis. | a 500 bp fragment encoding an isoform of cysteine proteinase from leishmania (leishmania) amazonensis was subcloned and expressed in the phis vector, resulting in a recombinant protein of 24 kda, rlacys24. in western blots of l. (l.) amazonensis extracts, antibodies directed to rlacys24 recognized a cysteine proteinase isoform of 30 kda. analysis by fluorescence-activated cell sorter showed a significantly higher expression of cd8(+) lymphocytes in animals immunized with rlacys24 plus cfa, where ... | 2010 | 19735658 |
| leishmanicidal, trypanocidal, and cytotoxic activities of endophytic fungi associated with bioactive plants in brazil. | one hundred and twenty-one isolates of endophytic fungi were recovered from leaves of the bioactive brazilian plant species ageratum myriadenia , palicourea tetraphylla , piptadenia adiantoides, and trixis vauthieri. all fungal isolates were cultivated in liquid media and crude extracts were obtained with ethyl acetate. the crude extracts were tested in bioassay panels using leishmania amazonensis , trypanosoma cruzi, the enzyme trypanothione reductase (tryr) from trypanosoma cruzi, and three hu ... | 2010 | 24031513 |
| morphological and physiological changes in leishmania promastigotes induced by yangambin, a lignan obtained from ocotea duckei. | we have previously demonstrated that yangambin, a lignan obtained from ocotea duckei vattimo (lauraceae), shows antileishmanial activity against promastigote forms of leishmania chagasi and leishmania amazonensis. the aim of this study was to determine the in vitro effects of yangambin against these parasites using electron and confocal microscopy. l. chagasi and l. amazonensis promastigotes were incubated respectively with 50 μg/ml and 65 μg/ml of pure yangambin and stained with acridine orange ... | 2011 | 20691682 |
| leishmania amazonensis: partial purification and study of the biochemical properties of the telomerase reverse transcriptase activity from promastigote-stage. | telomeres are protein-dna complexes that protect chromosome ends from degradation and fusion. in leishmania spp., telomeric dna comprises a conserved ttaggg repeat and is maintained by telomerase. telomerase is a multisubunit enzymatic complex that ensures the complete dna replication by adding new telomeric repeats to the g-rich strand. in this report we aimed to purify and study the biochemical properties of leishmania amazonensis telomerase. in a first trial we used affinity chromatography wi ... | 2011 | 20692257 |
| leishmania amazonensis meta2 protein confers protection against heat shock and oxidative stress. | the meta cluster of leishmania amazonensis contains both meta1 and meta2 genes, which are upregulated in metacyclic promastigotes and encode proteins containing the meta domain. previous studies defined meta2 as a 48.0-kda protein, which is conserved in other leishmania species and in trypanosoma brucei. in this work, we demonstrate that meta2 protein expression is regulated during the leishmania life cycle but constitutive in t. brucei. meta2 protein is present in the cytoplasm and flagellum of ... | 2011 | 20713053 |
| babassu aqueous extract (bae) as an adjuvant for t helper (th)1-dependent immune responses in mice of a th2 immune response-prone strain. | the aqueous extract of a brazilian palm-tree fruit - the babassu - (bae) exerts a clear immunostimulative activity in vivo. in the present work, the possibility that bae can promote th1 immune responses in mice of a th2 immune response-prone strain - the balb/c was investigated. bae itself, and preparations consisting of leishmania amazonensis promastigote extract (le), adsorbed or not to al(oh)3, and in the presence or not of bae, were used as immunogens. le and al(oh)3 have been shown to prefe ... | 2011 | 21276258 |
| effect of the synadenium carinatum latex lectin (scll) on leishmania (leishmania) amazonensis infection in murine macrophages. | antiparasitic effect of a lectin isolated from synadenium carinatum latex (scll) was evaluated against leishmania (leishmania) amazonensis promastigotes/amastigotes. pretreatment of murine inflammatory peritoneal macrophages with scll reduced by 65.5% the association index of macrophages and l. (l) amazonensis promastigotes. expression of cytokines (il-12, il-1 and tnf-a) was detected in infected macrophages pretreated with scll (10µg/ml). scll also reduced the growth of l. (l) amazonensis amast ... | 2011 | 21320493 |
| immune and inflammatory responses to leishmania amazonensis isolated from different clinical forms of human leishmaniasis in cba mice. | leishmania amazonensis causes different diseases depending on the host and parasitic virulence factors. in this study, cba mice were infected with l. amazonensis isolates from patients with localized (ba125), diffuse cutaneous (ba276) or visceral leishmaniasis (ba109). mice infected with ba125 and ba276 progressed rapidly and lesions displayed an infiltrate rich in parasitized macrophages and were necrotic and ulcerated. ba109 induced smaller lesions and a mixed inflammatory infiltrate without n ... | 2011 | 21340351 |
| [evidence of transmission of visceral leishmaniasis by lutzomyia cruzi in the municipality of jaciara, state of mato grosso, brazil]. | the municipality of jaciara was classified in 2003 as a transmission area for visceral leishmaniasis in outbreak situations. this study aimed to establish evidence of transmission of leishmania (leishmania) infantum chagasi by lutzomyia cruzi in the municipality of jaciara, state of mato grosso, brazil. | 2011 | 21340413 |
| reactive oxygen species production and mitochondrial dysfunction contribute to quercetin induced death in leishmania amazonensis. | leishmaniasis, a parasitic disease caused by protozoa of the genus leishmania, affects more than 12 million people worldwide. quercetin has generated considerable interest as a pharmaceutical compound with a wide range of therapeutic activities. one such activity is exhibited against the bloodstream parasite trypanosoma brucei and amastigotes of leishmania donovani. however, the mechanism of protozoan action of quercetin has not been studied. | 2011 | 21346801 |
| in vitro antileishmanial activity and cytotoxicity of essential oil from lippia sidoides cham. | leishmaniasis is a widespread tropical infection caused by different species of leishmania protozoa. there is no vaccine available for leishmania infections and conventional treatments are very toxic to the patients. therefore, antileishmanial drugs are urgently needed. in this study we have analyzed the effects of essential oils from lippia sidoides (lseo) and its major compound thymol on the growth, viability and ultrastructure of leishmania amazonensis. the essential oil and thymol showed sig ... | 2011 | 21421075 |