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Sample records for mexicana mexicana promastigotes

  1. Spectroscopic study of antileishmanial drug incubated in the promastigotes of Leishmania mexicana

    NASA Astrophysics Data System (ADS)

    Hung, J.; Castillo, J.; Jiménez, G.; Hasegawa, M.; Rodriguez, M.

    2003-11-01

    In this work we present spectroscopic study of Boldine (aporphine alkaloid) that possesses important biological activities, in particular, in interaction with the promastigotes of Leishmania mexicana. The results show the applicability of autofluorescence of this drug to determinate the possible mechanism of its biological action. The blue shift and hyperchromic effect in the emission spectrum of the drug in interaction with the parasite cells indicate an energy transference process between them. The morphological change of cell shape of the promastigotes treated with the drug is observed using confocal microscopy. This morphological cell-shape transformation evidences an important interaction between the drug studied and some protein of the parasite cell. Here we describe for the first time the fluorescence properties of the Boldine in the promastigotes of L. mexicana.

  2. Specific immunization of mice against Leishmania mexicana amazonensis using solubilized promastigotes

    NASA Technical Reports Server (NTRS)

    Barral-Netto, M.; Sadigursky, M.; Reed, S. G.; Sonnenfeld, G.

    1987-01-01

    In this work, it was demonstrated that mice (BALB/c strain) highly susceptible to Leishmania mexicana amazonensis can be protected against infection by this parasite by being preimmunized with whole solubilized (in a buffer that contained EDTA, NP-40, and SDS) promastigotes; the use of adjuvant or intact inactivated parasite cells is shown to be not necessary. The best immunization schedule consisted of three intravenous injections of 5 x 10 to the 7th parasite equivalents, administered one to eight weeks before infection. Immunized mice exhibited a marked inhibition of primary lesion development, reduced numbers of parasites in the spleen, and reduced death rate.

  3. Specific immunization of mice against Leishmania mexicana amazonensis using solubilized promastigotes

    NASA Technical Reports Server (NTRS)

    Barral-Netto, M.; Sadigursky, M.; Reed, S. G.; Sonnenfeld, G.

    1987-01-01

    In this work, it was demonstrated that mice (BALB/c strain) highly susceptible to Leishmania mexicana amazonensis can be protected against infection by this parasite by being preimmunized with whole solubilized (in a buffer that contained EDTA, NP-40, and SDS) promastigotes; the use of adjuvant or intact inactivated parasite cells is shown to be not necessary. The best immunization schedule consisted of three intravenous injections of 5 x 10 to the 7th parasite equivalents, administered one to eight weeks before infection. Immunized mice exhibited a marked inhibition of primary lesion development, reduced numbers of parasites in the spleen, and reduced death rate.

  4. Leishmania mexicana: promastigotes and amastigotes secrete protein phosphatases and this correlates with the production of inflammatory cytokines in macrophages.

    PubMed

    Escalona-Montaño, A R; Ortiz-Lozano, D M; Rojas-Bernabé, A; Wilkins-Rodriguez, A A; Torres-Guerrero, H; Mondragón-Flores, R; Mondragón-Gonzalez, R; Becker, I; Gutiérrez-Kobeh, L; Aguirre-Garcia, M M

    2016-09-01

    Phosphatase activity of Leishmania spp. has been shown to deregulate the signalling pathways of the host cell. We here show that Leishmania mexicana promastigotes and amastigotes secrete proteins with phosphatase activity to the culture medium, which was higher in the Promastigote Secretion Medium (PSM) as compared with the Amastigote Secretion Medium (ASM) and was not due to cell lysis, since parasite viability was not affected by the secretion process. The biochemical characterization showed that the phosphatase activity present in PSM was higher in dephosphorylating the peptide END (pY) INASL as compared with the peptide RRA (pT)VA. In contrast, the phosphatase activity in ASM showed little dephosphorylating capacity for both peptides. Inhibition assays demonstrated that the phosphatase activity of both PSM and ASM was sensible only to protein tyrosine phosphatases inhibitors. An antibody against a protein phosphatase 2C (PP2C) of Leishmania major cross-reacted with a 44·9 kDa molecule in different cellular fractions of L. mexicana promastigotes and amastigotes, however, in PSM and ASM, the antibody recognized a protein about 70 kDa. By electron microscopy, the PP2C was localized in the flagellar pocket of amastigotes. PSM and ASM induced the production of tumor necrosis factor alpha, IL-1β, IL-12p70 and IL-10 in human macrophages.

  5. Proteophosphoglycans of Leishmania mexicana. Molecular cloning and characterization of the Leishmania mexicana ppg2 gene encoding the proteophosphoglycans aPPG and pPPG2 that are secreted by amastigotes and promastigotes.

    PubMed Central

    Göpfert, U; Goehring, N; Klein, C; Ilg, T

    1999-01-01

    Intracellular amastigotes of the pathogenic protozoon Leishmania mexicana secrete an extensively phosphoglycosylated proteophosphoglycan (aPPG) into the phagolysosome of mammalian host macrophages, that appears to fulfil important functions for the parasites. Promastigotes (the sandfly vector forms) of the same species secrete a proteophosphoglycan with identical protein backbone but exhibiting stage-specific phosphoglycosylation patterns [Klein, Göpfert, Goehring, Stierhof and Ilg (1999) Biochem. J. 344, 775-786]. In this study we report the cloning of the novel repeat-containing proteophosphoglycan gene ppg2 by antibody screening of a Leishmania mexicana amastigote cDNA expression library. ppg2 is equally expressed in promastigotes and amastigotes at the mRNA level. Targeted gene replacement of both alleles of the single copy gene ppg2 results in the loss of pPPG2 expression in promastigotes. Antisera against Escherichia coli-expressed ppg2 recognize the deglycosylated forms of aPPG as well as pPPG2. These results confirm that ppg2 encodes the protein backbones of aPPG and pPPG2. An unusual finding is that ppg2 exhibits two stable allelic forms, ppg2a and ppg2b. Their main difference lies in the number of central 72 bp DNA repeats (7 versus 8). ppg2a and ppg2b encode polypeptide chains of 574 and 598 amino acids, respectively, that show no homology to known proteins. The novel 24 amino acid Ser-rich peptide repeats encoded by the 72 bp DNA repeats are targets for Ser phosphoglycosylation in Leishmania mexicana. PMID:10585865

  6. Gluconeogenesis in Leishmania mexicana

    PubMed Central

    Rodriguez-Contreras, Dayana; Hamilton, Nicklas

    2014-01-01

    Gluconeogenesis is an active pathway in Leishmania amastigotes and is essential for their survival within the mammalian cells. However, our knowledge about this pathway in trypanosomatids is very limited. We investigated the role of glycerol kinase (GK), phosphoenolpyruvate carboxykinase (PEPCK), and pyruvate phosphate dikinase (PPDK) in gluconeogenesis by generating the respective Leishmania mexicana Δgk, Δpepck, and Δppdk null mutants. Our results demonstrated that indeed GK, PEPCK, and PPDK are key players in the gluconeogenesis pathway in Leishmania, although stage-specific differences in their contribution to this pathway were found. GK participates in the entry of glycerol in promastigotes and amastigotes; PEPCK participates in the entry of aspartate in promastigotes, and PPDK is involved in the entry of alanine in amastigotes. Furthermore, the majority of alanine enters into the pathway via decarboxylation of pyruvate in promastigotes, whereas pathway redundancy is suggested for the entry of aspartate in amastigotes. Interestingly, we also found that l-lactate, an abundant glucogenic precursor in mammals, was used by Leishmania amastigotes to synthesize mannogen, entering the pathway through PPDK. On the basis of these new results, we propose a revision in the current model of gluconeogenesis in Leishmania, emphasizing the differences between amastigotes and promastigotes. This work underlines the importance of studying the trypanosomatid intracellular life cycle stages to gain a better understanding of the pathologies caused in humans. PMID:25288791

  7. Ergosterone-coupled Triazol molecules trigger mitochondrial dysfunction, oxidative stress, and acidocalcisomal Ca(2+) release in Leishmania mexicana promastigotes.

    PubMed

    Figarella, K; Marsiccobetre, S; Arocha, I; Colina, W; Hasegawa, M; Rodriguez, M; Rodriguez-Acosta, A; Duszenko, M; Benaim, G; Uzcategui, N L

    2015-12-11

    The protozoan parasite Leishmania causes a variety of sicknesses with different clinical manifestations known as leishmaniasis. The chemotherapy currently in use is not adequate because of their side effects, resistance occurrence, and recurrences. Investigations looking for new targets or new active molecules focus mainly on the disruption of parasite specific pathways. In this sense, ergosterol biosynthesis is one of the most attractive because it does not occur in mammals. Here, we report the synthesis of ergosterone coupled molecules and the characterization of their biological activity on Leishmania mexicana promastigotes. Molecule synthesis involved three steps: ergosterone formation using Jones oxidation, synthesis of Girard reagents, and coupling reaction. All compounds were obtained in good yield and high purity. Results show that ergosterone-triazol molecules (Erg-GTr and Erg-GTr2) exhibit an antiproliferative effect in low micromolar range with a selectivity index ~10 when compared to human dermic fibroblasts. Addition of Erg-GTr or Erg-GTr2 to parasites led to a rapid [Ca(2+)]cyt increase and acidocalcisomes alkalinization, indicating that Ca(2+) was released from this organelle. Evaluation of cell death markers revealed some apoptosis-like indicators, as phosphatidylserine exposure, DNA damage, and cytosolic vacuolization and autophagy exacerbation. Furthermore, mitochondrion hyperpolarization and superoxide production increase were detected already 6 hours after drug addition, denoting that oxidative stress is implicated in triggering the observed phenotype. Taken together our results indicate that ergosterone-triazol coupled molecules induce a regulated cell death process in the parasite and may represent starting point molecules in the search of new chemotherapeutic agents to combat leishmaniasis.

  8. Ergosterone-coupled Triazol molecules trigger mitochondrial dysfunction, oxidative stress, and acidocalcisomal Ca2+ release in Leishmania mexicana promastigotes

    PubMed Central

    Figarella, K; Marsiccobetre, S; Arocha, I; Colina, W; Hasegawa, M; Rodriguez, M; Rodriguez-Acosta, A; Duszenko, M; Benaim, G; Uzcategui, NL

    2015-01-01

    The protozoan parasite Leishmania causes a variety of sicknesses with different clinical manifestations known as leishmaniasis. The chemotherapy currently in use is not adequate because of their side effects, resistance occurrence, and recurrences. Investigations looking for new targets or new active molecules focus mainly on the disruption of parasite specific pathways. In this sense, ergosterol biosynthesis is one of the most attractive because it does not occur in mammals. Here, we report the synthesis of ergosterone coupled molecules and the characterization of their biological activity on Leishmania mexicana promastigotes. Molecule synthesis involved three steps: ergosterone formation using Jones oxidation, synthesis of Girard reagents, and coupling reaction. All compounds were obtained in good yield and high purity. Results show that ergosterone-triazol molecules (Erg-GTr and Erg-GTr2) exhibit an antiproliferative effect in low micromolar range with a selectivity index ~10 when compared to human dermic fibroblasts. Addition of Erg-GTr or Erg-GTr2 to parasites led to a rapid [Ca2+]cyt increase and acidocalcisomes alkalinization, indicating that Ca2+ was released from this organelle. Evaluation of cell death markers revealed some apoptosis-like indicators, as phosphatidylserine exposure, DNA damage, and cytosolic vacuolization and autophagy exacerbation. Furthermore, mitochondrion hyperpolarization and superoxide production increase were detected already 6 hours after drug addition, denoting that oxidative stress is implicated in triggering the observed phenotype. Taken together our results indicate that ergosterone-triazol coupled molecules induce a regulated cell death process in the parasite and may represent starting point molecules in the search of new chemotherapeutic agents to combat leishmaniasis. PMID:28357313

  9. Isotopomer Profiling of Leishmania mexicana Promastigotes Reveals Important Roles for Succinate Fermentation and Aspartate Uptake in Tricarboxylic Acid Cycle (TCA) Anaplerosis, Glutamate Synthesis, and Growth*

    PubMed Central

    Saunders, Eleanor C.; Ng, William W.; Chambers, Jennifer M.; Ng, Milica; Naderer, Thomas; Krömer, Jens O.; Likić, Vladimir A.; McConville, Malcolm J.

    2011-01-01

    Leishmania parasites proliferate within nutritionally complex niches in their sandfly vector and mammalian hosts. However, the extent to which these parasites utilize different carbon sources remains poorly defined. In this study, we have followed the incorporation of various 13C-labeled carbon sources into the intracellular and secreted metabolites of Leishmania mexicana promastigotes using gas chromatography-mass spectrometry and 13C NMR. [U-13C]Glucose was rapidly incorporated into intermediates in glycolysis, the pentose phosphate pathway, and the cytoplasmic carbohydrate reserve material, mannogen. Enzymes involved in the upper glycolytic pathway are sequestered within glycosomes, and the ATP and NAD+ consumed by these reactions were primarily regenerated by the fermentation of phosphoenolpyruvate to succinate (glycosomal succinate fermentation). The initiating enzyme in this pathway, phosphoenolpyruvate carboxykinase, was exclusively localized to the glycosome. Although some of the glycosomal succinate was secreted, most of the C4 dicarboxylic acids generated during succinate fermentation were further catabolized in the TCA cycle. A high rate of TCA cycle anaplerosis was further suggested by measurement of [U-13C]aspartate and [U-13C]alanine uptake and catabolism. TCA cycle anaplerosis is apparently needed to sustain glutamate production under standard culture conditions. Specifically, inhibition of mitochondrial aconitase with sodium fluoroacetate resulted in the rapid depletion of intracellular glutamate pools and growth arrest. Addition of high concentrations of exogenous glutamate alleviated this growth arrest. These findings suggest that glycosomal and mitochondrial metabolism in Leishmania promastigotes is tightly coupled and that, in contrast to the situation in some other trypanosomatid parasites, the TCA cycle has crucial anabolic functions. PMID:21636575

  10. Anthraquinones from Vismia mexicana.

    PubMed

    Reyes-Chilpa, Ricardo; Gómez-Cansino, Rocío; Guzmán-Gutiérrez, Silvia Laura; Hernández-Ortega, Simón; Campos-Lara, María; Vega-Avila, Elisa; Nieto-Camacho, Antonio

    2014-01-01

    Vismia mexicana (Clusiaceae) is a small tropical tree found from Mexico to Honduras. The CH2Cl2/MeOH extract from the leaves has been reported to have inhibitory properties against reverse transcriptase of human immunodeficiency virus type 1 (HIV-1 RT). In order to characterize some of its chemical constituents, the EtOAc-soluble fraction of this extract was subjected to column chromatography. A new natural product was isolated and designated vismiaquinone D [1-hydroxy-6-methoxy-7,8-(3',3'-dimethyl-pyrano) anthraquinone]. In addition, vismiaquinone was obtained. The structures of vismiaquinone and vismiaquinone D were determined by 1H and 13C NMR spectroscopy, unambiguous assignments were achieved with DEPT, HSQC, and HMBC experiments, and corroborated by X-ray diffraction studies. The isolated anthraquinones were tested against HIV-1 RT. However, none showed relevant activity, suggesting that other compounds in this extract may be responsible for its HIV-1 RT inhibitory properties.

  11. Photoacoustic monitoring of life cycles of Leishmania Mexicana

    NASA Astrophysics Data System (ADS)

    Arguello, C.; Acosta-Avalos, D.; Alvarado-Gil, J. J.; Vargas, H.

    1999-03-01

    Photoacoustic spectroscopy is used to monitor in situ, the difference between the two forms of the protozoan Leishmania Mexicana. Differences are the result of changes in the respiratory chain and could be attributed, according to our results, to the presence of cytochrome b in promastigotes and cytochrome c in amastigotes.

  12. Isolation and analysis of a new developmentally regulated gene from amastigotes of Leishmania mexicana mexicana.

    PubMed

    Liu, K; Zinker, S; Argüello, C; Salgado, L M

    2000-02-01

    Leishmania differentiates from the promastigote to the amastigote stage during its digenetic life cycle. Characterization of the developmentally regulated genes during that process would help to elucidate the mechanisms of gene regulation. In this study, specific fragments of mRNAs from the amastigote stage of L. mexicana mexicana were discriminated from those of the promastigote and metacyclic stages by differential display. This technique combined with spliced-leader polymerase chain reaction allowed isolation of the complete gene VG7A5. The sequence of this gene did not align with any published L. mexicana sequence. More than one copy of this gene was identified in the genome by Southern-blot analysis and was transcribed exclusively in the amastigote stage. At 20 bp upstream from the splice AG site it has a trans-splicing polypyrimidine tract. The gene encodes the subcellular localization motifs 5'-GGACT and AAGCT-3' in the 3' untranslated region of the mRNA. The open reading frame of the gene VG7A5 predicts a polypeptide of 587 amino acid residues that has a KGRR amidation motif near its carboxyl terminus, suggesting that in the mammalian host this protein may be involved in the process of acute inflammation.

  13. A new languidulane diterpenoid from Salvia mexicana var. mexicana.

    PubMed

    Frontana-Uribe, Bernardo Antonio; Escárcega-Bobadilla, Martha Verónica; Estrada-Reyes, Rosa; Morales-Serna, José Antonio; Salmón, Manuel; Cárdenas, Jorge

    2011-10-21

    From the aerial parts of Salvia mexicana var. mexicana, two C-10 epimers (α and β) of salvimexicanolide were isolated. Our interpretation of the data, especially the 13C NMR, led us to conclude that the previously described 13C-NMR spectrum of the α-epimer was not accurately assigned and it actually corresponds to the β-epimer. The structures proposed for the salvimexicanolides were verified by means of NOESY experiments. Dugesin B, arbutin, naringenin and the mixture of oleanolic and ursolic acids were also isolated from this Salvia spp.

  14. Proteophosphoglycans of Leishmania mexicana. Identification, purification, structural and ultrastructural characterization of the secreted promastigote proteophosphoglycan pPPG2, a stage-specific glycoisoform of amastigote aPPG.

    PubMed Central

    Klein, C; Göpfert, U; Goehring, N; Stierhof, Y D; Ilg, T

    1999-01-01

    Protozoan parasites of the genus Leishmania secrete a range of proteophosphoglycans that appear to be important for successful colonization of the sandfly and for virulence in the mammalian host. A hallmark of these molecules is extensive phosphoglycosylation by phosphoglycan chains via the unusual linkage Manalpha1-PO(4)-Ser. In this study we have identified and purified to apparent homogeneity a novel proteophosphoglycan (pPPG2) which is secreted by Leishmania mexicana promastigotes (sandfly stage). Amino acid analysis and immunoblots using polypeptide-specific antisera suggest that pPPG2 shares a common protein backbone with a proteophosphoglycan (aPPG) secreted by Leishmania mexicana amastigotes (mammalian stage). Both pPPG2 and aPPG show a similar degree of Ser phosphoglycosylation (50. 5 mol% vs. 44.6 mol%), but the structure of their phosphoglycan chains is developmentally regulated: in contrast to aPPG which displays unique, complex and highly branched glycan chains [Ilg, Craik, Currie, Multhaup, and Bacic (1998) J. Biol. Chem. 273, 13509-13523], pPPG2 contains short unbranched structures consisting of >60 mol% neutral glycans, most likely (Manalpha1-2)(0-5)Man and Galbeta1-4Man, as well as about 40 mol% monophosphorylated glycans of the proposed structures PO(4)-6Galbeta1-4Man and PO(4)-6(Glcbeta1-3)Galbeta1-4Man. The major differences between pPPG2 and aPPG with respect to their apparent molecular mass, their ultrastructure and their proteinase sensitivity are most likely a consequence of this stage-specific glycosylation of their common protein backbone. PMID:10585864

  15. Leishmania mexicana amazonensis

    PubMed Central

    Detke, S.; Elsabrouty, R.

    2008-01-01

    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 transporter to supplement their purine or energy requirements via preformed ATP from its host. Rather, Leishmania appear to use the plasma membrane ANT as part of a chemotaxis response. ATP is a chemorepellent for Leishmania and cells treated with atractyloside, an inhibitor of ANT, no longer exhibit negative chemotaxis for this compound. PMID:18031742

  16. Protective immunogenicity of the paraflagellar rod protein 2 of Leishmania mexicana.

    PubMed

    Saravia, N G; Hazbón, M H; Osorio, Y; Valderrama, L; Walker, J; Santrich, C; Cortázar, T; Lebowitz, J H; Travi, B L

    2005-01-11

    Paraflagellar rod proteins (PFR) are a potent immunogen against experimental Trypanosoma cruzi infection. PFR are highly conserved among kinetoplastid parasites. We therefore evaluated the immunogenicity of the Leishmania mexicana pfr-2 gene and protein product in the hamster model of American cutaneous leishmaniasis. Immunization with pfr-2 DNA-induced specific antibody, confirming immunogenicity. Subsequent challenge with 10,000 and 500 stationary phase L. mexicana promastigotes respectively, resulted in delayed appearance of lesions, and significant reduction in lesions post infection in male hamsters, yet exacerbated lesions in female hamsters. Immunization with recombinant PFR-2 protein (rPFR-2) prevented lesion development in female hamsters challenged with L. panamensis, but was ineffective against L. mexicana. Nevertheless, prime boost immunization of female hamsters with rPFR and pfr-2 DNA significantly reduced lesion size following challenge with 500 L. mexicana promastigotes, supporting the relevance of PFR-2 as a potential vaccine constituent.

  17. Cytochemical localization of acid phosphatase in Leishmania mexicana amazonensis.

    PubMed

    Pimenta, P F; De Souza, W

    1986-01-01

    Acid phosphatase was cytochemically detected at the ultrastructural level in infective and non-infective promastigotes and in amastigotes of the parasitic protozoan Leishmania mexicana amazonensis. Cerium chloride was used as the capture agent of the phosphate liberated during the hydrolysis of the substrate (Na-beta-glycerophosphate). Reaction product, indicative of enzyme activity, was seen in the outer face of the plasma membrane of many, but not all, infective and noninfective promastigote forms. No reaction product was seen in the plasma membrane of amastigote forms. Reaction product was seen in the endoplasmic reticulum, in the Golgi complex, in vesicles located close to the flagellar pocket and in cytoplasmic structures which may represent lysosomes. No reaction product was seen when the substrate was omitted from or sodium fluoride was added to the incubation medium. The possible role played by the acid phosphatase present in the plasma membrane of Leishmania parasites is discussed.

  18. Natural Sesquiterpene Lactones Induce Oxidative Stress in Leishmania mexicana

    PubMed Central

    Barrera, Patricia; Sülsen, Valeria P.; Lozano, Esteban; Rivera, Mónica; Beer, María Florencia; Tonn, Carlos; Martino, Virginia S.; Sosa, Miguel A.

    2013-01-01

    Leishmaniasis is a worldwide parasitic disease, caused by monoflagellate parasites of the genus Leishmania. In the search for more effective agents against these parasites, the identification of molecular targets has been attempted to ensure the efficiency of drugs and to avoid collateral damages on the host's cells. In this work, we have investigated some of the mechanisms of action of a group of natural sesquiterpene lactones that are effective against Leishmania mexicana mexicana promastigotes. We first observed that the antiproliferative effect of mexicanin I (Mxc), dehydroleucodine (DhL), psilostachyin (Psi), and, at lesser extent, psilostachyin C (Psi C) is blocked by 1.5 mM reduced glutathione. The reducing agent was also able to reverse the early effect of the compounds, suggesting that lactones may react with intracellular sulfhydryl groups. Moreover, we have shown that all the sesquiterpene lactones, except Psi C, significantly decreased the endogenous concentration of glutathione within the parasite. Consistent with these findings, the active sesquiterpene lactones increased between 2.7 and 5.4 times the generation of ROS by parasites. These results indicate that the induction of oxidative stress is at least one of the mechanisms of action of DhL, Mxc, and Psi on parasites while Psi C would act by another mechanism. PMID:23861697

  19. T-Cell Responses to Immunodominant LACK Antigen Do Not Play a Critical Role in Determining Susceptibility of BALB/c Mice to Leishmania mexicana

    PubMed Central

    Torrentera, Fabiola Aguilar; Glaichenhaus, Nicolas; Laman, Jon D.; Carlier, Yves

    2001-01-01

    Although BALB/c mice develop lesions when infected with Leishmania mexicana, the mechanisms which are responsible for susceptibility to this parasite have not been elucidated. In contrast, susceptibility of BALB/c mice to Leishmania major has been shown to depend on the early production of interleukin-4 (IL-4) by T cells which react to the parasitic LACK antigen. Here, we demonstrate that the lesions induced by L. mexicana are delayed compared to those induced by L. major but rapidly develop at later time points. Interestingly, while LACK-tolerant BALB/c-derived IE-LACK transgenic mice were resistant to L. major, they were susceptible to L. mexicana and developed lesions similar to those observed in wild-type BALB/c mice. The latter result was observed despite the fact that (i) LACK was expressed by L. mexicana, (ii) splenocytes from BALB/c mice were able to stimulate LACK-specific T-cell hybridoma cells when incubated with live L. mexicana promastigotes, and (iii) LACK-specific T cells contributed to IL-4 production in L. mexicana-infected BALB/c mice. Thus, in contrast to what was observed for L. major-infected mice, LACK-specific T cells do not play a critical role in determining susceptibility to L. mexicana. Although BALB/c mice are susceptible to both L. major and L. mexicana, the mechanisms which are responsible for susceptibility to these parasites are likely to be different. PMID:11119565

  20. Leishmania mexicana cell death achieved by Cleoserrata serrata (Jacq.) Iltis: Learning from Maya healers.

    PubMed

    Alamilla-Fonseca, Lorena Noemi; Delgado-Domínguez, José; Zamora-Chimal, Jaime; Cervantes-Sarabia, Rocely Buenaventura; Jiménez-Arellanes, Adelina; Rivero-Cruz, José Fausto; Becker, Ingeborg

    2017-09-28

    Aerial parts of Cleoserrata serrata (Jacq.) Iltis are widely used in South-Central Mexico to treat wounds and bacterial skin infections and in Panama by Kuna, Ngöbe-Buglé, and Teribe Indians for tropical warm baths and by Kunas in the form of "Ina kuamakalet" for snakebites. To evaluate the effect of Cleoserrata serrata extract on growth and viability of L. mexicana amastigotes and promastigotes in vitro, as well as on bacteria that usually co-infect skin ulcers. Cleoserrata serrata was collected in La Chontalpa, Tabasco, Mexico. The antiproliferative effect of the extract was tested on growth of Leishmania mexicana amastigotes and promastigotes in vitro, as well as on bacteria that usually co-infect skin ulcers. Our data show that Cleoserrata serrata significantly inhibits parasite growth (which was more important in infective amastigotes) and additionally inhibits growth of the co-infective bacteria Staphylococcus aureus and Pseudomonas aeruginosa. Confocal microscopy showed a leishmanicidal effect. We conclude that Cleoserrata serrata extract is potentially an optimal treatment alternative for patients with cutaneous leishmaniasis infected with Leishmania mexicana, since it controls both the parasite as well as bacterial co-infections. Furthermore, it can be applied topically. The precise metabolites responsible for the anti-Leishmania and anti-bacterial effects remain to be established. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Triose-phosphate isomerase of Leishmania mexicana mexicana. Cloning and characterization of the gene, overexpression in Escherichia coli and analysis of the protein.

    PubMed

    Kohl, L; Callens, M; Wierenga, R K; Opperdoes, F R; Michels, P A

    1994-03-01

    The gene of triose-phosphate isomerase in Leishmania mexicana has been cloned and characterized. The gene encodes a polypeptide of 251 amino acids, with a calculated molecular mass of 27,561 Da and a net charge of +2. Only one gene could be detected, although the enzyme is present in two different compartments of the cell, in microbody-like organelles called glycosomes and in the cytosol. The primary structure of the enzyme has many features in common with that of triose-phosphate isomerase in the related organism Trypanosoma brucei. Their sequences are 68% identical. The residues constituting the subunit interface are highly conserved between the enzyme of L. mexicana and T. brucei, but are mostly different from those in the enzyme of other organisms. One major substitution was detected in the interface region of the L. mexicana protein: a glutamate was found at position 66, instead of glutamine in all other available 20 sequences. The glutamine is thought to be important for the stability of the dimeric enzyme. L. mexicana triose-phosphate isomerase has been overexpressed in Escherichia coli. Growth conditions were established to obtain high levels of soluble and active protein. The enzyme has been purified to near homogeneity. It appears a stable dimeric protein with a specific activity of 5500 units/mg protein, a subunit mass of 28 kDa and an isoelectric point of 9.0. The enzyme has also been partially purified from glycosomes of cultured L. mexicana promastigotes. Some kinetic properties of the recombinant protein have been compared with those of the promastigote enzyme and with the values previously reported for the T. brucei enzyme. The kinetics of the different enzyme preparations were very similar. For the recombinant enzyme the following values were measured: with glyceraldehyde 3-phosphate as substrate Km = 0.30 +/- 0.05 mM and kcat = 2.5 x 10(5) min-1; with dihydroxyacetone phosphate as substrate Km = 1.3 +/- 0.3 mM and kcat = 2.8 x 10(4) min-1.

  2. Spasmogenic and spasmolytic activities of Agastache mexicana ssp. mexicana and A. mexicana ssp. xolocotziana methanolic extracts on the guinea pig ileum.

    PubMed

    Ventura-Martínez, Rosa; Rodríguez, Rodolfo; González-Trujano, María Eva; Ángeles-López, Guadalupe E; Déciga-Campos, Myrna; Gómez, Claudia

    2017-01-20

    Agastache mexicana has been used in traditional medicine for relief of abdominal pain and treatment of other diseases. Two subspecies have been identified: A. mexicana ssp. mexicana (AMM) and A. mexicana ssp. xolocotziana (AMX) and both are used traditionally without distinction or in combination. To determine the effect of methanol extracts of A. mexicana ssp. mexicana and A. mexicana ssp. xolocotziana on gut motility and their possible mechanism of action. The effect of AMM and AMX methanol extracts were tested on the spontaneous activity in the isolated guinea pig ileum and on tissues pre-contracted with KCl, electrical field stimulation (EFS) or ACh. In addition, the possible mechanism of action of each subspecies on gut motility was analyzed in the presence of hexametonium, indomethacin, L-NAME, verapamil, atropine or pyrylamine. A comparative chromatographic profile of these extracts was also done to indicate the most abundant flavonoids presents in methanol extracts of both subspecies. AMM, but not AMX, induced a contractile effect in the guinea pig ileum. This spasmogenic effect was partially inhibited by atropine, antagonist of muscarinic receptors; and pyrilamine, antagonist of H1 receptors. In contrast, AMX, but not AMM, diminished the contractions induced by KCl, EFS or ACh. The spasmolytic activity of AMX was partially inhibited by hexamethonium, ganglionic blocker; and indomethacin, inhibitor of the synthesis of prostaglandins; but not by L-NAME, inhibitor of nitric oxide synthase. In addition, AMX diminished the maximal contraction induced by CaCl2 in a calcium-free medium. Chromatographic analyses of these methanol extracts showed the presence of acacetin and tilanin in both. These results suggest that in folk medicine only AMX should be used as spasmolytic, and not in combination with AMM as traditionally occurs, due to the spasmogenic effects of the latter. In addition, activation of nicotinic receptors, prostaglandins and calcium channels, but

  3. Leishmaniasis in Texas: Isolation of Leishmania mexicana from Neotoma Micropus

    DTIC Science & Technology

    1990-01-01

    leishmaniasis cases in Texas, 2) Lutzomyia anthophora, a sand fly which has transmitted Leishmania mexicana under laboratory conditions (Endris et al., 1984... temperatures > 37 C are all suggestive of L. mexicana. Isozyme characterization determined that the parasite isolated from N. micropus collected in Texas is L...Addis, 1945). Other vertebrates such as opossums, hispid cotton rats, and armadillos and other sand flies such as Lutzomyia diabolica and Lutzomyia texana

  4. Leishmania mexicana metacaspase is a negative regulator of amastigote proliferation in mammalian cells.

    PubMed

    Castanys-Muñoz, E; Brown, E; Coombs, G H; Mottram, J C

    2012-09-06

    Metacaspases (MCAs) are caspase family cysteine peptidases that have been implicated in cell death processes in plants, fungi and protozoa. MCAs have also been suggested to be involved in cell cycle control, differentiation and clearance of aggregates; they are virulence factors. Dissecting the function of MCAs has been complicated by the presence in many organisms of multiple MCA genes or limitations on genetic manipulation. We describe here the creation of a MCA gene-deletion mutant (Δmca) in the protozoan parasite Leishmania mexicana, which has allowed us to dissect the role of the parasite's single MCA gene in cell growth and cell death. Δmca parasites are viable as promastigotes, and differentiate normally to the amastigote form both in in vitro macrophages infection and in mice. Δmca promastigotes respond to cell death inducers such as the drug miltefosine and H(2)O(2) similarly to wild-type (WT) promastigotes, suggesting that MCAs do not have a caspase-like role in execution of L. mexicana cell death. Δmca amastigotes replicated significantly faster than WT amastigotes in macrophages and in mice, but not as axenic culture in vitro. We propose that the Leishmania MCA acts as a negative regulator of amastigote proliferation, thereby acting to balance cell growth and cell death.

  5. Antifungal and Anticancer Potential of Argemone mexicana L.

    PubMed Central

    More, Nilesh V.; Kharat, Arun S.

    2016-01-01

    Background: Medicinal plants are widely used to treat infectious diseases, metabolic disorders and cancer. Argemone mexicana L. (A. mexicana), commonly found on desolate land of Marathwada (Maharashtra, India) has been used to treat oral cavity infections. Methods: In this study, cold aqueous and methanolic extracts were prepared from A. mexicana stem and leaves. These extracts were tested for their antifungal and anticancer activities. The antifungal activity was tested using the agar well diffusion method, while the anticancer activity against immortalized cell lines was assessed by trypan blue assay. Results: It was observed that both cold aqueous and methanolic extracts of A. mexicana stem and leaves inhibited the growth of Mucor indicus, Aspergillus flavus, Aspergillus niger and Penicillum notatum. Antifungal activity of the extract was comparable to that of Amphoterecin-B. A. mexicana extracts had a cytotoxic effect on A549, SiHa and KB immortalized cell lines that were similar to that of berberine. Conclusion: The A. mexicana leaf and stems exhibit strong antifungal and anticancer potential.

  6. Nitric oxide production by Peromyscus yucatanicus (Rodentia) infected with Leishmania (Leishmania) mexicana

    PubMed Central

    Loría-Cervera, Elsy Nalleli; Sosa-Bibiano, Erika Ivett; Villanueva-Lizama, Liliana Estefanía; Van Wynsberghe, Nicole Raymonde; Canto-Lara, Silvia Beatriz; Batún-Cutz, José Luis; Andrade-Narváez, Fernando José

    2013-01-01

    Peromyscus yucatanicus (Rodentia: Cricetidae) is a primary reservoir of Leishmania (Leishmania) mexicana (Kinetoplastida: Trypanosomatidae). Nitric oxide (NO) generally plays a crucial role in the containment and elimination of Leishmania. The aim of this study was to determine the amount of NO produced by P. yucatanicus infected with L. (L.) mexicana. Subclinical and clinical infections were established in P. yucatanicus through inoculation with 1 x 102 and 2.5 x 106 promastigotes, respectively. Peritoneal macrophages were cultured alone or co-cultured with lymphocytes with or without soluble Leishmania antigen. The level of NO production was determined using the Griess reaction. The amount of NO produced was significantly higher (p ≤ 0.0001) in co-cultured macrophages and lymphocytes than in macrophages cultured alone. No differences in NO production were found between P. yucatanicus with subclinical L. (L.) mexicana infections and animals with clinical infections. These results support the hypothesis that the immunological mechanisms of NO production in P. yucatanicus are similar to those described in mouse models of leishmaniasis and, despite NO production, P. yucatanicus is unable to clear the parasite infection. PMID:23579796

  7. Insecticides induced biochemical changes in freshwater microalga Chlamydomonas mexicana.

    PubMed

    Kumar, Muthukannan Satheesh; Kabra, Akhil N; Min, Booki; El-Dalatony, Marwa M; Xiong, Jiuqiang; Thajuddin, Nooruddin; Lee, Dae Sung; Jeon, Byong-Hun

    2016-01-01

    The effect of insecticides (acephate and imidacloprid) on a freshwater microalga Chlamydomonas mexicana was investigated with respect to photosynthetic pigments, carbohydrate and protein contents, fatty acids composition and induction of stress indicators including proline, superoxide dismutase (SOD) and catalase (CAT). C. mexicana was cultivated with 1, 5, 10, 15, 20 and 25 mg L(-1) of acephate and imidacloprid. The microalga growth increased with increasing concentrations of both insecticides up to 15 mg L(-1), beyond which the growth declined compared to control condition (without insecticides). C. mexicana cultivated with 15 mg L(-1) of both insecticides for 12 days was used for further analysis. The accumulation of photosynthetic pigments (chlorophyll and carotenoids), carbohydrates and protein was decreased in the presence of both insecticides. Acephate and imidacloprid induced the activities of superoxide dismutase (SOD) and catalase (CAT) and increased the concentration of proline in the microalga, which play a defensive role against various environmental stresses. Fatty acid analysis revealed that the fraction of polyunsaturated fatty acids decreased on exposure to both insecticides. C. mexicana also promoted 25 and 21% removal of acephate and imidacloprid, respectively. The biochemical changes in C. mexicana on exposure to acephate and imidacloprid indicate that the microalga undergoes an adaptive change in response to the insecticide-induced oxidative stress.

  8. Leishmania (L.) mexicana infected bats in Mexico: novel potential reservoirs.

    PubMed

    Berzunza-Cruz, Miriam; Rodríguez-Moreno, Ángel; Gutiérrez-Granados, Gabriel; González-Salazar, Constantino; Stephens, Christopher R; Hidalgo-Mihart, Mircea; Marina, Carlos F; Rebollar-Téllez, Eduardo A; Bailón-Martínez, Dulce; Balcells, Cristina Domingo; Ibarra-Cerdeña, Carlos N; Sánchez-Cordero, Víctor; Becker, Ingeborg

    2015-01-01

    Leishmania (Leishmania) mexicana causes cutaneous leishmaniasis, an endemic zoonosis affecting a growing number of patients in the southeastern states of Mexico. Some foci are found in shade-grown cocoa and coffee plantations, or near perennial forests that provide rich breeding grounds for the sand fly vectors, but also harbor a variety of bat species that live off the abundant fruits provided by these shade-giving trees. The close proximity between sand flies and bats makes their interaction feasible, yet bats infected with Leishmania (L.) mexicana have not been reported. Here we analyzed 420 bats from six states of Mexico that had reported patients with leishmaniasis. Tissues of bats, including skin, heart, liver and/or spleen were screened by PCR for Leishmania (L.) mexicana DNA. We found that 41 bats (9.77%), belonging to 13 species, showed positive PCR results in various tissues. The infected tissues showed no evidence of macroscopic lesions. Of the infected bats, 12 species were frugivorous, insectivorous or nectarivorous, and only one species was sanguivorous (Desmodus rotundus), and most of them belonged to the family Phyllostomidae. The eco-region where most of the infected bats were caught is the Gulf Coastal Plain of Chiapas and Tabasco. Through experimental infections of two Tadarida brasiliensis bats in captivity, we show that this species can harbor viable, infective Leishmania (L.) mexicana parasites that are capable of infecting BALB/c mice. We conclude that various species of bats belonging to the family Phyllostomidae are possible reservoir hosts for Leishmania (L.) mexicana, if it can be shown that such bats are infective for the sand fly vector. Further studies are needed to determine how these bats become infected, how long the parasite remains viable inside these potential hosts and whether they are infective to sand flies to fully evaluate their impact on disease epidemiology.

  9. Leishmania (L.) mexicana Infected Bats in Mexico: Novel Potential Reservoirs

    PubMed Central

    Berzunza-Cruz, Miriam; Rodríguez-Moreno, Ángel; Gutiérrez-Granados, Gabriel; González-Salazar, Constantino; Stephens, Christopher R.; Hidalgo-Mihart, Mircea; Marina, Carlos F.; Rebollar-Téllez, Eduardo A.; Bailón-Martínez, Dulce; Balcells, Cristina Domingo; Ibarra-Cerdeña, Carlos N.; Sánchez-Cordero, Víctor; Becker, Ingeborg

    2015-01-01

    Leishmania (Leishmania) mexicana causes cutaneous leishmaniasis, an endemic zoonosis affecting a growing number of patients in the southeastern states of Mexico. Some foci are found in shade-grown cocoa and coffee plantations, or near perennial forests that provide rich breeding grounds for the sand fly vectors, but also harbor a variety of bat species that live off the abundant fruits provided by these shade-giving trees. The close proximity between sand flies and bats makes their interaction feasible, yet bats infected with Leishmania (L.) mexicana have not been reported. Here we analyzed 420 bats from six states of Mexico that had reported patients with leishmaniasis. Tissues of bats, including skin, heart, liver and/or spleen were screened by PCR for Leishmania (L.) mexicana DNA. We found that 41 bats (9.77%), belonging to 13 species, showed positive PCR results in various tissues. The infected tissues showed no evidence of macroscopic lesions. Of the infected bats, 12 species were frugivorous, insectivorous or nectarivorous, and only one species was sanguivorous (Desmodus rotundus), and most of them belonged to the family Phyllostomidae. The eco-region where most of the infected bats were caught is the Gulf Coastal Plain of Chiapas and Tabasco. Through experimental infections of two Tadarida brasiliensis bats in captivity, we show that this species can harbor viable, infective Leishmania (L.) mexicana parasites that are capable of infecting BALB/c mice. We conclude that various species of bats belonging to the family Phyllostomidae are possible reservoir hosts for Leishmania (L.) mexicana, if it can be shown that such bats are infective for the sand fly vector. Further studies are needed to determine how these bats become infected, how long the parasite remains viable inside these potential hosts and whether they are infective to sand flies to fully evaluate their impact on disease epidemiology. PMID:25629729

  10. Enhanced action of amphotericin B on Leishmania mexicana resulting from heat transformation.

    PubMed Central

    Ramos, H; Milhaud, J; Cohen, B E; Bolard, J

    1990-01-01

    A comparative study of the effect of the polyene antibiotic amphotericin B (AmB) on the viability of Leishmania mexicana promastigotes before and after their transformation by heat into amastigotelike forms was carried out. The kinetics of cell death were followed by spectrofluorometry with the nucleic acid-binding compound ethidium bromide. It was found that the rapid killing effect that is exerted by AmB on Leishmania promastigotes was even faster after their transformation into amastigotelike forms. Binding studies of AmB to Leishmania membranes by circular dichroism indicated that heat transformation modified it from noncooperative to cooperative binding, decreasing the amount of antibiotic that bound to the membranes. Thus, the increased rate of ethidium bromide incorporation into transformed cells was not related either to the amount of AmB bound or to an increased amount of ergosterol in the membrane (the ergosterol/phospholipid ratio was four times smaller after heat shock). An increase in the Mg2+ content of the external aqueous solution was able to prevent the AmB-induced incorporation of ethidium bromide into Leishmania promastigotes to a greater extent (Ki = 13.8 mM) than it was into heat-transformed cells (Ki = 64 mM), suggesting that there were significant changes at the Leishmania cell surface on heat transformation. The significance of these results for understanding the mechanism of action of AmB on sensitive organisms is discussed. PMID:2221868

  11. In vitro activity of synthetic tetrahydroindeno[2,1-c]quinolines on Leishmania mexicana.

    PubMed

    Hernández-Chinea, Concepción; Carbajo, Erika; Sojo, Felipe; Arvelo, Francisco; Kouznetsov, Vladimir V; Romero-Bohórquez, Arnold R; Romero, Pedro J

    2015-12-01

    New synthetic compounds based on tetrahydroindenoquinoline structure were evaluated for their in vitro antileishmanial activities. The seven compounds assayed have antiproliferative activities against promastigotes of Leishmania mexicana. Compound 1 and 3 were the most active (IC50 1.0 μg/ml) and showed high selectivity towards the parasite. These compounds were selected to evaluate their effect on promastigote morphology and mitochondrial transmembrane potential as well as on the amastigote capability to survive into macrophages J774 cell line. Whereas compound 1 affected the promastigote cell cycle, compound 3 induced morphological changes and the total collapse of the mitochondrial transmembrane potential, a hallmark of apoptosis. Both compounds also affected the amastigote form of the parasite, decreasing their survival rate in J774 macrophages. Due to the greatest selectivity index, the apparent effect as apoptotic inducer and its sustained inhibition on intracellular amastigote replication, compound 3 is the best candidate to be tested in vivo. This compound is worth considering for the development of new antileishmanial drugs. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. Dronedarone, an Amiodarone Analog with Improved Anti-Leishmania mexicana Efficacy

    PubMed Central

    Casanova, Paola; Hernandez-Rodriguez, Vanessa; Mujica-Gonzalez, Sheira; Parra-Gimenez, Nereida; Plaza-Rojas, Lourdes; Concepcion, Juan Luis; Liu, Yi-Liang; Oldfield, Eric; Paniz-Mondolfi, Alberto; Suarez, Alirica I.

    2014-01-01

    Dronedarone and amiodarone are cationic lipophilic benzofurans used to treat cardiac arrhythmias. They also have activity against the parasitic protozoan Trypanosoma cruzi, the causative agent of Chagas' disease. They function by disrupting intracellular Ca2+ homeostasis of the parasite and by inhibiting membrane sterol (ergosterol) biosynthesis. Amiodarone also has activity against Leishmania mexicana, suggesting that dronedarone might likewise be active against this organism. This might be of therapeutic interest, since dronedarone is thought to have fewer side effects in humans than does amiodarone. We show here that dronedarone effectively inhibits the growth of L. mexicana promastigotes in culture and, more importantly, has excellent activity against amastigotes inside infected macrophages (the clinically relevant form) without affecting the host cell, with the 50% inhibitory concentrations against amastigotes being 3 orders of magnitude lower than those obtained previously with T. cruzi amastigotes (0.65 nM versus 0.75 μM). As with amiodarone, dronedarone affects intracellular Ca2+ homeostasis in the parasite, inducing an elevation of intracellular Ca2+ levels. This is achieved by rapidly collapsing the mitochondrial membrane potential and inducing an alkalinization of acidocalcisomes at a rate that is faster than that observed with amiodarone. We also show that dronedarone inhibits parasite oxidosqualene cyclase, a key enzyme in ergosterol biosynthesis known to be vital for survival. Overall, our results suggest the possibility of repurposing dronedarone as a treatment for cutaneous, and perhaps other, leishmaniases. PMID:24492373

  13. First case report of pulmonary nocardiosis caused by Nocardia mexicana

    PubMed Central

    Ikeda, Takeshi; Nakanishi, Hirotaka; Morishita, Yukiko; Houdai, Katsuyuki; Ito, Junko; Gonoi, Tohru

    2016-01-01

    Introduction: Nocardia species usually cause opportunistic infections, and the frequency of these infections is increasing owing to the growing population of immunocompromised hosts. However, Nocardia species may sometimes cause an infection disease in immunocompetent hosts. Nocardia mexicana infections are the least common and are very rare. Case presentation: Herein, we report the first case of a pulmonary infection with N. mexicana in a 61-year-old Japanese woman with a history of hyperlipidaemia and bronchiectasis and a 6-month history of non-productive hacking cough. A sample of bronchial lavage fluid obtained by bronchofiberscopy showed filamentous branching gram-positive rods and acid-fast filamentous branching rods, and a colony of suspected Nocardia was cultured. Based on 16S rRNA, gyrB, rpoB, secA1 and hsp65 gene sequence analyses and biochemical and physiological properties, the strain was identified as N. mexicana. The strain was resistant to the antimicrobial agents amoxicillin-clavulanic acid, clarithromycin, minocycline, gentamycin, tobramycin, ciprofloxacin and trimethoprim-sulfamethoxazole. The patient was treated with biapenem followed by intravenous amikacin and oral linezolid. Conclusion: Despite its rarity, the species require attention owing to the existence of multidrug-resistant strains. PMID:28348776

  14. Regulatory volume decrease in Leishmania mexicana: effect of anti-microtubule drugs

    PubMed Central

    Dagger, Francehuli; Valdivieso, Elizabeth; Marcano, Ana K; Ayesta, Carlos

    2013-01-01

    The trypanosomatid cytoskeleton is responsible for the parasite's shape and it is modulated throughout the different stages of the parasite's life cycle. When parasites are exposed to media with reduced osmolarity, they initially swell, but subsequently undergo compensatory shrinking referred to as regulatory volume decrease (RVD). We studied the effects of anti-microtubule (Mt) drugs on the proliferation of Leishmania mexicana promastigotes and their capacity to undergo RVD. All of the drugs tested exerted antiproliferative effects of varying magnitudes [ansamitocin P3 (AP3)> trifluoperazine > taxol > rhizoxin > chlorpromazine]. No direct relationship was found between antiproliferative drug treatment and RVD. Similarly, Mt stability was not affected by drug treatment. Ansamitocin P3, which is effective at nanomolar concentrations, blocked amastigote-promastigote differentiation and was the only drug that impeded RVD, as measured by light dispersion. AP3 induced 2 kinetoplasts (Kt) 1 nucleus cells that had numerous flagella-associated Kts throughout the cell. These results suggest that the dramatic morphological changes induced by AP3 alter the spatial organisation and directionality of the Mts that are necessary for the parasite's hypotonic stress-induced shape change, as well as its recovery. PMID:23440120

  15. Conditional gene deletion with DiCre demonstrates an essential role for CRK3 in Leishmania mexicana cell cycle regulation.

    PubMed

    Duncan, Samuel M; Myburgh, Elmarie; Philipon, Cintia; Brown, Elaine; Meissner, Markus; Brewer, James; Mottram, Jeremy C

    2016-06-01

    Leishmania mexicana has a large family of cyclin-dependent kinases (CDKs) that reflect the complex interplay between cell cycle and life cycle progression. Evidence from previous studies indicated that Cdc2-related kinase 3 (CRK3) in complex with the cyclin CYC6 is a functional homologue of the major cell cycle regulator CDK1, yet definitive genetic evidence for an essential role in parasite proliferation is lacking. To address this, we have implemented an inducible gene deletion system based on a dimerised Cre recombinase (diCre) to target CRK3 and elucidate its role in the cell cycle of L. mexicana. Induction of diCre activity in promastigotes with rapamycin resulted in efficient deletion of floxed CRK3, resulting in G2/M growth arrest. Co-expression of a CRK3 transgene during rapamycin-induced deletion of CRK3 resulted in complementation of growth, whereas expression of an active site CRK3(T178E) mutant did not, showing that protein kinase activity is crucial for CRK3 function. Inducible deletion of CRK3 in stationary phase promastigotes resulted in attenuated growth in mice, thereby confirming CRK3 as a useful therapeutic target and diCre as a valuable new tool for analyzing essential genes in Leishmania. © 2016 The Authors. Molecular Microbiology Published by John Wiley & Sons Ltd.

  16. Case Report: Transient Success Using Prolonged Treatment with Miltefosine for a Patient with Diffuse Cutaneous Leishmaniasis Infected with Leishmania mexicana mexicana

    PubMed Central

    Ordaz-Farias, Alejandro; Muñoz-Garza, Fania Z.; Sevilla-Gonzalez, Farah K.; Arana-Guajardo, Ana; Ocampo-Candiani, Jorge; Treviño-Garza, Nancy; Becker, Ingeborg; Camacho-Ortiz, Adrian

    2013-01-01

    Leishmania sp. is an intracellular parasite that causes a variable degree of clinical manifestations, especially in the skin. We present the case of a 38-year-old male with a chronic history of mucocutaneous disease present since childhood that generated deformity, loss of cartilage in the ears and nose, and scarring that limited his range of motion. The parasite was identified as L. mexicana mexicana. The patient was treated with a 3-month course of oral miltefosine with overwhelming results. PMID:23243111

  17. IgG1 Is Pathogenic in Leishmania mexicana Infection

    PubMed Central

    Chu, Niansheng; Thomas, Bolaji N.; Patel, Supriya R.; Buxbaum, Laurence U.

    2010-01-01

    There are over 2 million new cases of leishmaniasis annually, and no effective vaccine has been developed to prevent infection. In murine infection, Leishmania mexicana, which lives intracellularly in host macrophages, has developed pathways to hijack host IgG to induce a suppressive IL-10 response through FcγRs, the cell-surface receptors for IgG. To guide vaccine development away from detrimental Ab responses, which can accompany attempts to induce cell-mediated immunity, it is crucial to know which isotypes of IgG are pathogenic in this infection. We have found that IgG1 and IgG2a/c induce IL-10 from macrophages in vitro equally well but through different FcγR subtypes: IgG1 through FcγRIII, and IgG2a/c through FcγRI primarily, but also through FcγRIII. In sharp contrast, mice lacking IgG1 develop earlier and stronger IgG2a/c, IgG3, and IgM responses to L. mexicana infection and yet are more resistant to the infection. Thus, IgG1, but not IgG2a/c or IgG3, is pathogenic in vivo, in agreement with prior studies indicating that FcγRIII is required for chronic disease. This calls into question the assumption that macrophages, which should secrete IL-10 in response to both IgG1 and IgG2a/c immune complexes, are the most important source of IL-10 generated by IgG-FcγR engagement in L. mexicana infection. Further investigations are required to better determine the cell type responsible for this immunosuppressive FcγRIII-induced IL-10 pathway and whether IgG2a/c is protective. PMID:21037092

  18. Leishmania mexicana: chemistry and biochemistry of sodium stibogluconate (Pentostam)

    SciTech Connect

    Berman, J.D.; Grogl, M.

    1988-10-01

    The chemical properties of the primary antileishmanial agent sodium stibogluconate (Pentostam), and the interaction of Pentostam with Leishmania mexicana amastigotes, have been investigated with the aid of (/sup 125/Sb)Pentostam. The molecular weight by P2 chromatography showed (/sup 125/Sb)Pentostam to be of multiple species of MW = 100-4000 Da, rather than the one species of 746 Da predicted by the commonly hypothesized structural formula. Nonradioactive Pentostam had a lower osmolarity (789 mOsm for a 100 mg Sb/ml solution) than predicted (1644 mOsm), which indicates that the multiple components of Pentostam (Sb and derivatives of gluconic acid) are more closely complexed with each other than previously thought. When incubated with L. mexicana amastigotes, labeled drug was bound to at least six polypeptides of molecular weights ranging from 14,000 to 68,000 Da as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Interaction with the polypeptides is presumed to contribute to the antileishmanial action of Pentostam.

  19. Foraging habits of Alouatta palliata mexicana in three forest fragments.

    PubMed

    Asensio, Norberto; Cristobal-Azkarate, Jurgi; Dias, Pedro Américo D; Vea, Joaquim J; Rodríguez-Luna, Ernesto

    2007-01-01

    The activity patterns and diet of howler monkeys (Alouatta palliata mexicana) were studied in 3 forest fragments in south-eastern Mexico: Playa Escondida (PLA), Agaltepec Island (AGA) and Arroyo Liza (LIZ). Intersite differences offered the opportunity to investigate the foraging adaptations of howler monkeys in response to population and habitat size. In the largest fragment (PLA), the howlers' diet was based on high-quality items (fruit and young leaves). In AGA, where the density of howlers was the highest, their diet was mostly folivorous with a marked exploitation of uncommon food items such as vines, lianas, shrubs and herbs. The dietary differences in AGA were accompanied by more time spent travelling and less time spent resting. Although LIZ was the smallest fragment and had a high howler density, the small group size and the use of energy-minimizing strategies (less time spent travelling and more time spent resting) probably allowed howlers to maintain a frugivorous diet.

  20. Leishmania Mexicana: Uptake of Sodium Stibogluconate (Pentostam) and Pentamidine by Parasite and Macrophages

    DTIC Science & Technology

    1987-01-01

    brucei-group Trypano- Leishmania donovani in vitro. Comparative Bio- soma. Journal of Protozoology 23, 349-356. chemistry and Physiology 68c, 95-98...NO.ACESON.Ft Detrick, Frederick, MD 21701-5012 ELEMENT NO. ACCESSION NO 11, TITLE (Include Security Classification) LEISHMANIA MEXICANA: UPTAKE OF...RESEARCH BRIEF Leishmania mexicana: Uptake of Sodium Stibogluconate (Pentostam) and Pentamidine by Parasite and Macrophages JONATHAN D. BERMAN

  1. Effects of steroidal allenic phosphonic acid derivatives on the parasitic protists Leishmania donovani, Leishmania mexicana mexicana, and Pneumocystis carinii carinii.

    PubMed Central

    Beach, D H; Chen, F; Cushion, M T; Macomber, R S; Krudy, G A; Wyder, M A; Kaneshiro, E S

    1997-01-01

    Several pathogenic fungi and protozoa are known to have sterols distinct from those of their mammalian hosts. Of particular interest as targets for drug development are the biosyntheses of the sterols of important parasites such as the kinetoplastid flagellates and the AIDS-associated opportunistic protist Pneumocystis carinii. These pathogens synthesize sterols with an alkyl group at C-24, and some have a double bond at C-22 of the side chain. Humans and other mammalian hosts are incapable of C-24 alkylation and C-22 desaturation. In the present study, three steroidal compounds with side chains substituted by phosphonyl-linked groups were synthesized and tested for their effects on Leishmania donovani and L. mexicana mexicana culture growth. The compounds inhibited organism proliferation at concentrations in micrograms per milliliter. The most potent inhibitors of this group of compounds were characterized by two ethyl groups at the phosphate function. Leishmania organisms treated with 17-[2-(diethylphosphonato) ethylidienyl]3-methoxy-19-norpregna-1,3,5-triene exhibited reduced growth after transfer into inhibitor-free medium. Because there are currently no axenic methods available for the continuous subcultivation of P. carinii, the effects of these drugs on this organism were evaluated by two alternative screening methods. The same two diethyl phosphonosteroid compounds that inhibited Leishmania proliferation were also the most active against P. carinii as determined by the potent effect they had on reducing cellular ATP content. Cystic as well as trophic forms responded to the drug treatments, as evaluated by a dual fluorescent staining live-dead assay. Other modifications of steroidal phosphonates may lead to the development of related drugs with increased activity and specificity for the pathogens. PMID:8980773

  2. Pentalinon andrieuxii root extract is effective in the topical treatment of cutaneous leishmaniasis caused by Leishmania mexicana

    PubMed Central

    Lezama-Dávila, Claudio M.; Pan, Li; Isaac-Márquez, Angelica P.; Terrazas, Cesar; Oghumu, Steve; Isaac-Márquez, Ricardo; Pech-Dzib, MY; Barbi, Joseph; Calomeni, Edward; Parinandi, Narasimham; Kinghorn, A. Douglas; Satoskar, Abhay R.

    2014-01-01

    Cutaneous leishmaniasis (CL) manifests as localized skin lesions, which lead to significant tissue destruction and disfigurement. In the Yucatan Peninsula, Mayan traditional healers use Pentalinon andrieuxii Muell.-Arg. (Apocynaceae) roots for the topical treatment of CL. Here, we studied the effect of P. andrieuxii root hexane extract (PARE) on the parasites and host cells in vitro and examined its efficacy in the topical treatment of CL caused by L. mexicana. PARE exhibited potent antiparasitic activity in vitro against promastigotes as well as amastigotes residing in macrophages. Electron microscopy of PARE-treated parasites revealed direct membrane damage. PARE also activated NF-κB and enhanced IFN-γR and MHC class II expression and TNF-α production in macrophages. In addition, PARE induced production of the Th1 promoting cytokine IL-12 in dendritic cells as well as enhanced expression of the co-stimulatory molecules CD40, CD80 and CD86. In vivo studies showed that L. mexicana-infected mice treated by topical application of PARE resulted in the significant reduction in lesion size and parasite burden compared to controls. These findings indicate that PARE could be used as an alternative therapy for the topical treatment of CL. PMID:24347110

  3. Molecular Characterization, Expression and in vivo Analysis of LmexCht1: the Chitinase of the Human Pathogen, Leishmania mexicana

    PubMed Central

    Joshi, Manju B.; Rogers, Matthew E.; Shakarian, Alison M.; Yamage, Mat; Al-Harthi, Saeed A.; Bates, Paul A.; Dwyer, Dennis M.

    2010-01-01

    SUMMARY Chitinases have been implicated to be of importance in the life cycle development and transmission of a variety of parasitic organisms. Using a molecular approach, we identified and characterized the structure of a single copy LmexCht1-chitinase gene from the primitive trypanosomatid pathogen of humans, Leishmania mexicana. The LmexCht1 encodes an ~50 kDa protein, with well-conserved substrate-binding and catalytic domains characteristic of members of the Chitinase-18 protein family. Further, we showed that LmexCht1 mRNA is constitutively expressed by both the insect vector (i.e. promastigote) and mammalian (i.e. amastigote) life cycle developmental forms of this protozoan parasite. Interestingly, however, amastigotes were found to secrete/release ~ >2-4 fold higher levels of chitinase activity during their growth in vitro than promastigotes. Moreover, a homologous episomal-expression system was devised and used to express an epitope–tagged LmexCht1 chimeric construct in these parasites. Expression of the LmexCht1 chimera was verified in these transfectants by RT-PCR, Western blots and indirect immunofluorescence analyses. Further, results of coupled-immunoprecipitation/ enzyme activity experiments demonstrated that the LmexCht1 chimeric protein was secreted/released by these transfected L. mexicana parasites and that it possessed functional chitinase enzyme activity. Such transfectants were also evaluated for their infectivity both in human macrophages in vitro and in two different strains of mice. Results of those experiments demonstrated that the LmexCht1 transfectants survived significantly better in human macrophages and also produced significantly larger lesions in mice than control parasites. Taken together, our results indicate that the LmexCht1-chimera afforded a definitive survival advantage to the parasite within these mammalian hosts. Thus, the LmexCht1 could potentially represent a new virulence determinant in the mammalian phase of this

  4. The Mexican Seismic Network (Red Sísmica Mexicana)

    NASA Astrophysics Data System (ADS)

    Valdes-Gonzales, C. M.; Arreola-Manzano, J.; Castelan-Pescina, G.; Alonso-Rivera, P.; Saldivar-Rangel, M. A.; Rodriguez-Arteaga, O. O.; Lopez-Lena-Villasana, R.

    2014-12-01

    The Mexican Seismic Network (Red Sísmica Mexicana) was created to give sufficient information and opportune to make decisions in order to mitigate seismic and tsunami risk. This was a Mexican government initiative headed by CENAPRED (National Disaster Prevention Center) who made an effort to integrated academic institutions and civil agencies to work together through a collaboration agreement. This network is supported by Universidad National Autónoma de México (UNAM) and its seismic networks (Broad Band and Strong Motion), the Centro de Instrumentación y Registro Sismico (CIRES) with its Earthquake Early Warning System that covers the Guerrero Gap and Oaxaca earthquakes, The Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE) with the support of its expertise in tsunami observation and the Secretaria de Marina (SEMAR) to monitor the sea level and operate the Mexican Tsunami Warning Center. The institutions involved in this scope have the compromise to interchange and share the data and advice to the Civil Protection authorities.

  5. Glycosomal membrane proteins and lipids from Leishmania mexicana.

    PubMed

    Quiñones, Wilfredo; Cáceres, Ana J; Ruiz, Maria Tibisay; Concepción, Juan Luis

    2015-04-01

    Constituents of the glycosomal membrane from Leishmania mexicana should play a critical role in the coordination of metabolic processes occurring in the cytosol and those compartmentalized within glycosomes. We have made an inventory of glycosomal membrane-associated proteins using approaches specific for enriching both integral and peripheral membrane proteins. Surprisingly, 70% of the proteins were recovered in the hydrophobic fraction of membranes solubilized with Triton X-114, while 20% were present in the soluble fraction obtained upon treatment with Na2CO3. 14 major polypeptides, ranging in molecular weight from 65 to 16 kDa, were found to be associated with the membrane, nine of them behaving as integral membrane proteins. Assessment of their topology in the membrane indicated that the polypeptides of 56, 50, 46 and 32 kDa have no domains exposed to the cytosol. The 50 kDa protein is the most abundant one of the glycosomal membrane, where it is peripherically located at the matrix face. The major phospholipids of glycosomal membranes are phosphatidyl-ethanolamine, phosphatidyl-choline and phosphatidyl-serine, with smaller proportions of sphingomyelin and phosphatidyl-inositol. The sterols found were of 5-dehydroepisterol, ergosta-5,7,24(24(1))-trien-3β-ol, and also their precursors, consistent with the notion that these organelles are involved in de novo biosynthesis of sterols in trypanosomatids. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Triterpenes from Agarista mexicana as potential antidiabetic agents.

    PubMed

    Perez G, R M; Vargas S, R

    2002-02-01

    Hypoglycaemic activity-guided fractionation together with chemical analysis led to the isolation of 12-ursene and a novel triterpene 23,24 dimethyl-24-ethyl-stigmast-25-ene from the chloroform extract of the dried stem of A. mexicana. Identification was based on spectroscopic methods. The isolated triterpenes were tested for hypoglycaemic activity in normal and alloxman-diabetic CD1 mice 25-30 g at a dose of 50 mg/kg body weight. The blood glucose levels were determined before and 1.5, 3, 4.5 and 24 h after intraperitoneal drug administration. The results showed that the triterpenes produced a significant hypoglycaemic effect in normal as well as in diabetic mice. Comparison was made between the action of the triterpenes and a known hypoglycaemic drug, tolbutamide (50 mg/kg). The 12-ursene was found to be slow and less effective than tolbutamide, and the 23,24 dimethyl-24-ethyl-stigmast-25-ene was shown to be more effective than tolbutamide.

  7. Ciprofloxacin toxicity and its co-metabolic removal by a freshwater microalga Chlamydomonas mexicana.

    PubMed

    Xiong, Jiu-Qiang; Kurade, Mayur B; Kim, Jung Rae; Roh, Hyun-Seog; Jeon, Byong-Hun

    2017-02-05

    This study evaluated the toxicity and cellular stresses of ciprofloxacin (CIP) and its co-metabolic removal in a freshwater microalga Chlamydomonas mexicana. The toxicological effects of CIP on C. mexicana were assessed by studying the growth and biochemical characteristics of the microalga including total chlorophyll, carotenoid content, malondialdehyde (MDA) and superoxide dismutase (SOD) activity. The calculated effective concentration (EC50) of CIP on C. mexicana was 65±4mgL(-1) at 96h. The growth of C. mexicana was significantly inhibited at increased concentrations of CIP, showing 36±1, 75±3. and 88±3% inhibition at 40, 60 and 100mgL(-1) CIP, respectively, compared to the control after 11days of cultivation. The total chlorophyll, carotenoid, MDA and SOD activity were significantly increased as a result of relatively high concentrations of CIP stress. C. mexicana showed 13±1% removal of CIP (2mgL(-1)) after 11days of cultivation; however, the addition of an electron donor (sodium acetate, 4gL(-1)) highly enhanced the removal of CIP (2mgL(-1)) by>3-fold after 11days. Kinetic studies showed that removal of CIP followed a first-order model (R(2) 0.94-0.97) with the apparent rate constants (k) ranging from 0.0121 to 0.079 d(-1).

  8. Regions in the 3' untranslated region confer stage-specific expression to the Leishmania mexicana a600-4 gene.

    PubMed

    Murray, Angus; Fu, Christine; Habibi, Golareh; McMaster, W Robert

    2007-06-01

    Protozoan parasites of the genus Leishmania have a digenetic lifecycle, alternating between the promastigote and amastigote stages. The extracellular promastigote resides within a sandfly vector, while the obligate intracellular amastigote stage replicates in the phagolysosome of mammalian host macrophages. Adaptation to and survival within these vastly differently environments is accompanied by differential expression of a subset of genes, which is regulated post-transcriptionally via cis-acting elements in 3' untranslated region (3'UTR) or intercistronic sequences. It was reported previously that Leishmania mexicana A600-4 mRNA transcript abundance was eight-fold higher in the amastigotes. In this study, chimeric luciferase:A600-4 3'UTR reporter constructs were integrated at the A600 chromosome locus to identify regulatory regions of the A600-4 3'UTR sequence. Evidence is provided for distinct 3'UTR elements that function to stabilize the A600-4 mRNA transcript in the amastigote stage and to regulate translation efficiency, respectively.

  9. Conditional gene deletion with DiCre demonstrates an essential role for CRK3 in L eishmania mexicana cell cycle regulation

    PubMed Central

    Duncan, Samuel M.; Myburgh, Elmarie; Philipon, Cintia; Brown, Elaine; Meissner, Markus; Brewer, James

    2016-01-01

    Summary Leishmania mexicana has a large family of cyclin‐dependent kinases (CDKs) that reflect the complex interplay between cell cycle and life cycle progression. Evidence from previous studies indicated that Cdc2‐related kinase 3 (CRK3) in complex with the cyclin CYC6 is a functional homologue of the major cell cycle regulator CDK1, yet definitive genetic evidence for an essential role in parasite proliferation is lacking. To address this, we have implemented an inducible gene deletion system based on a dimerised Cre recombinase (diCre) to target CRK3 and elucidate its role in the cell cycle of L. mexicana. Induction of diCre activity in promastigotes with rapamycin resulted in efficient deletion of floxed CRK3, resulting in G2/M growth arrest. Co‐expression of a CRK3 transgene during rapamycin‐induced deletion of CRK3 resulted in complementation of growth, whereas expression of an active site CRK3 T178E mutant did not, showing that protein kinase activity is crucial for CRK3 function. Inducible deletion of CRK3 in stationary phase promastigotes resulted in attenuated growth in mice, thereby confirming CRK3 as a useful therapeutic target and diCre as a valuable new tool for analyzing essential genes in Leishmania. PMID:26991545

  10. Retention of Leishmania (Leishmania) mexicana in naturally infected rodents from the State of Campeche, Mexico.

    PubMed

    Van Wynsberghe, N R; Canto-Lara, S B; Damián-Centeno, A G; Itzá-Ortiz, M F; Andrade-Narváez, F J

    2000-01-01

    In the State of Campeche, Mexico, zoonotic cutaneous leishmaniasis is mainly due to Leishmania (L.) mexicana. The parasite population is maintained in a mammalian species, a reservoir in which the ideal course of infection should be long and relatively nonpathogenic. The objective of the present study was to document the retention of L. (L.) mexicana in 29 naturally infected rodents. These cricetids lived in captivity for up to two years and were tested monthly for the presence of the parasite, by cultures of needle aspirates from the base of the tail. Peromyscus yucatanicus and Ototylomys phyllotis were incriminated as the primary reservoir hosts. The finding that the multiplication of parasites in P. yucatanicus might be triggered by temperature, suggests that this animal would be a good choice for further research on L. (L.) mexicana.

  11. Oedema disease in chickens caused by Mexican poppy (Argemone mexicana) seed.

    PubMed

    Norton, J H; O'Rourke, P K

    1980-04-01

    Ground Mexican poppy (Argemone mexicana) seed produced growth depression, oedema and death when fed at 1% and 3% of a basal ration to day-old, layer strain, cockerel chickens. The mortality rate was increased by raising the sodium chloride content of the basal ration from 0.18% to 1.68%. Clinical signs consisted of subcutaneous oedema, a high pitched chirp and terminal gasping. Hydropericardium, oedema of the lungs, and subcutaneous oedema of the thorax, abdomen, wings, neck and throat were the major lesions. Foci of calcificaton were present in the ventricular myocardium of some chickens fed 3% A. mexicana.

  12. Seasonal transmission of Leishmania (Leishmania) mexicana in the state of Campeche, Yucatan Peninsula, Mexico.

    PubMed

    Andrade-Narvaez, Fernando J; Canto Lara, Silvia B; Van Wynsberghe, Nicole R; Rebollar-Tellez, Eduardo A; Vargas-Gonzalez, Alberto; Albertos-Alpuche, Nelly E

    2003-12-01

    In the Yucatan Peninsula, Mexico, localized cutaneous leishmaniasis (LCL) caused by Leishmania (Leishmania) mexicana is a typical wild zoonosis restricted to the forest, and humans are only accidentally involved. The transmission of L. (L.) mexicana has been related to the patient's occupation: "chicleros" (gum collectors) and agricultural workers. The objective of this study was to document L. (L.) mexicana seasonally of transmission in endemic areas of LCL in the state of Campeche, Yucatan Peninsula, Mexico. The timing of incidence of LCL in humans during 1993-1994, as well as the rate and time of infection in rodents and sand flies between February 1993 and March 1995 were analyzed. Rodents and sand flies were found infected between November and March, when men carried out their field activities and are exposed. Based on results analyzed, it is concluded that L. (L.) mexicana in the endemic area of LCL in the state of Campeche, Yucatan Peninsula, Mexico, presents a seasonal transmission restricted to the months of November to March. The knowledge of the timing of the transmission cycle in an endemic area of leishmaniasis is very important because intervention measures on the high-risk focus and population might be restricted.

  13. Counterstories of College Persistence by Undocumented Mexicana Students: Navigating Race, Class, Gender, and Legal Status

    ERIC Educational Resources Information Center

    Munoz, Susana Maria; Maldonado, Marta Maria

    2012-01-01

    This paper draws from four sets of four in-depth interviews and one subsequent focus group to examine how undocumented Mexicana students navigate identities and the meanings of race, gender, class, and legal status. We mobilize a critical race theory framework to center and explore the content of students' counterstories. While majoritarian…

  14. Seeking a "Mexicana"/"Mestiza" Ethic of Care: Rosa's "Revolución" of Carrying Alongside

    ERIC Educational Resources Information Center

    Sosa-Provencio, Mia Angélica

    2017-01-01

    This Chicana Critical Feminist "Testimonio" reveals a Mexican/Mexican-American Ethic of Care particular to the needs and strengths of "Mexicana/o" students and "Testimonios" of struggle, survival informing one Mexican/Mexican-American female educator of predominantly Mexican/Mexican-American students. This work,…

  15. "La Hermandad" and Chicanas Organizing: The Community Rhetoric of the "Comision Femenil Mexicana Nacional" Organization

    ERIC Educational Resources Information Center

    Leon, Kendall Marie

    2013-01-01

    To address the need for situated accounts of community rhetoric, this article examines the legacy of the first Chicana feminist organization, the "Comision Femenil Mexicana Nacional (CFMN)." The CFMN and their archival collection provide[d] Chicanas an education about how to interpret, be and act in the world. To invent a rhetorical…

  16. The california poppy (eschscholtzia mexicana) as a copper indicator plant - a new example

    USGS Publications Warehouse

    Chaffee, M.A.; Gale, C.W.

    1976-01-01

    The abundance and distribution of the California poppy (Eschscholtzia mexicana) correlates closely with the copper-rich outcrop of a small porphyry-type deposit in Arizona. Chemical factors are probably more important than physical factors in determining why this species is sometimes found as a copper indicator plant. ?? 1976.

  17. Clinical picture of cutaneous leishmaniases due to Leishmania (Leishmania) mexicana in the Yucatan peninsula, Mexico.

    PubMed

    Andrade-Narváez, F J; Vargas-González, A; Canto-Lara, S B; Damián-Centeno, A G

    2001-02-01

    Localized cutaneous leishmaniasis (LCL), known as "chiclero's ulcer" in southeast Mexico, was described by Seidelin in 1912. Since then, the sylvatic region of the Yucatan peninsula has been identified as an endemic focus of LCL. The purpose of the present work was to describe the clinical picture of LCL caused by Leishmania (Leishmania) mexicana in the Yucatan peninsula. A total of 136 cases of LCL, based on isolation and characterization of L. (L.) mexicana by isoenzymes and/or monoclonal antibodies, were selected. Some variability of clinical features regarding number, type, size, form, location and time of evolution of the lesions was observed. The most frequently observed presentation was a single, ulcerated, rounded small lesion, located on the ear, with an evolution time of less than three months, with neither cutaneous metastases nor lymphatic nor mucosal involvement. This picture corresponds to previous studies carried out in the same endemic area where an organism of the L. mexicana complex has been incriminated as a major aetiological agent of classical "chiclero's ulcer", confirming that in the Yucatan peninsula LCL due to L. (L.) mexicana when located on the pinna of the ear is a remarkable characteristic.

  18. Cytotoxicity of alkaloids isolated from Argemone mexicana on SW480 human colon cancer cell line.

    PubMed

    Singh, Sarita; Verma, Mradul; Malhotra, Meenakshi; Prakash, Satya; Singh, Tryambak Deo

    2016-01-01

    Argemone mexicana Linn. (Papaveraceae) has been used as traditional medicine in India and Taiwan for the treatment of skin diseases, inflammations, bilious, fever, etc. Some alkaloids of A. mexicana have been screened for their cytotoxicity on different cancer cell lines. The study investigates potential cytotoxic effects of alkaloids isolated from aerial part of A. mexicana on SW480 human colon cancer cell line. Six alkaloids, 13-oxoprotopine, protomexicine, 8-methoxydihydrosanguinarine, dehydrocorydalmine, jatrorrhizine, and 8-oxyberberine were isolated from the methanol extract of A. mexicana. Cytotoxicity of these alkaloids was studied on SW480 human colon cancer cell line at 1, 25, 50, 75, 100, 125, 150, and 200 µg/mL for 24 and 48 h. Cells were seeded in a 96-well micro-plate at a concentration of 2 × 10(4) cells per well and MTS assay was performed to assess cytotoxicity in terms of cell viability. At 200 µg/mL, protomexicine and 13-oxoprotopine showed mild cytotoxicity (∼24-28%) whereas dehydrocorydalmine exhibited moderate cytotoxicity (∼48%). 8-Oxyberberine was mildly cytotoxic (∼27%) at 24 h but was more potent (∼76%) at 48 h. Jatrorrhizine and 8-methoxydihydrosanguinarine were most potent (∼95-100%) in inhibiting the human colon cancer cell proliferation showing complete reduction in cell viability. This is the first study on the effect of these alkaloids on SW480 human colon cancer cell line. This study indicates that some alkaloids of A. mexicana strongly inhibit the cell proliferation in human colon cancer cells, and it might be a basis for future development of a potent chemotherapeutic drug.

  19. Population growth of Mexican free-tailed bats (Tadarida brasiliensis mexicana) predates human agricultural activity

    PubMed Central

    2011-01-01

    Background Human activities, such as agriculture, hunting, and habitat modification, exert a significant effect on native species. Although many species have suffered population declines, increased population fragmentation, or even extinction in connection with these human impacts, others seem to have benefitted from human modification of their habitat. Here we examine whether population growth in an insectivorous bat (Tadarida brasiliensis mexicana) can be attributed to the widespread expansion of agriculture in North America following European settlement. Colonies of T. b. mexicana are extremely large (~106 individuals) and, in the modern era, major agricultural insect pests form an important component of their food resource. It is thus hypothesized that the growth of these insectivorous bat populations was coupled to the expansion of agricultural land use in North America over the last few centuries. Results We sequenced one haploid and one autosomal locus to determine the rate and time of onset of population growth in T. b. mexicana. Using an approximate Maximum Likelihood method, we have determined that T. b. mexicana populations began to grow ~220 kya from a relatively small ancestral effective population size before reaching the large effective population size observed today. Conclusions Our analyses reject the hypothesis that T. b. mexicana populations grew in connection with the expansion of human agriculture in North America, and instead suggest that this growth commenced long before the arrival of humans. As T. brasiliensis is a subtropical species, we hypothesize that the observed signals of population growth may instead reflect range expansions of ancestral bat populations from southern glacial refugia during the tail end of the Pleistocene. PMID:21457563

  20. Amiodarone and Miltefosine Act Synergistically against Leishmania mexicana and Can Induce Parasitological Cure in a Murine Model of Cutaneous Leishmaniasis ▿

    PubMed Central

    Serrano-Martín, Xenón; Payares, Gilberto; De Lucca, Marisel; Martinez, Juan Carlos; Mendoza-León, Alexis; Benaim, Gustavo

    2009-01-01

    Leishmaniasis is parasitic disease that is an important problem of public health worldwide. Intramuscularly administered glucantime and pentostam are the most common drugs used for treatment of this disease, but they have significant limitations due to toxicity and increasing resistance. A recent breakthrough has been the introduction of orally administered miltefosine for the treatment of visceral, cutaneous, and mucocutaneous leishmaniasis, but the relative high cost and concerns about teratogenicity have limited the use of this drug. Searching for alternative drugs, we previously demonstrated that the antiarrhythmic drug amiodarone is active against Leishmania mexicana promastigotes and intracellular amastigotes, acting via disruption of intracellular Ca2+ homeostasis (specifically at the mitochondrion and the acidocalcisomes of these parasites) and through inhibition of the parasite's de novo sterol biosynthesis (X. Serrano-Martín, Y. García-Marchan, A. Fernandez, N. Rodriguez, H. Rojas, G. Visbal, and G. Benaim, Antimicrob. Agents Chemother. 53:1403-1410, 2009). In the present work, we found that miltefosine also disrupts the parasite's intracellular Ca2+ homeostasis, in this case by inducing a large increase in intracellular Ca2+ levels, probably through the activation of a plasma membrane Ca2+ channel. We also investigated the in vitro and in vivo activities of amiodarone and miltefosine, used alone or in combination, on L. mexicana. It was found that the drug combination had synergistic effects on the proliferation of intracellular amastigotes growing inside macrophages and led 90% of parasitological cures in a murine model of leishmaniasis, as revealed by a PCR assay using a novel DNA sequence specific for L. mexicana. PMID:19805563

  1. Aluminium phosphate potentiates the efficacy of DNA vaccines against Leishmania mexicana.

    PubMed

    Rosado-Vallado, Miguel; Mut-Martin, Mirza; García-Miss, Maria del Rosario; Dumonteil, Eric

    2005-11-16

    DNA vaccines have been able to induce partial protection against infection with Leishmania in mice, but it is still necessary to increase their efficacy. In the present study we evaluated aluminium phosphate as an adjuvant of different formulations and doses of DNA vaccines against L. mexicana in BALB/c mice. Aluminium phosphate had no effect on the humoral response induced by a high dose (100 microg) DNA vaccine, but slightly increased the cellular response and the protection against infection. It also allowed a non-immunoprotective low dose (20 microg) DNA vaccine encoding L. mexicana GP63 and Leishmania donovani NH36 to become protective. Aluminium phosphate may thus be an effective, low cost and safe adjuvant for DNA vaccines, and the vaccine formulation described here may be an excellent candidate for further vaccine development against Leishmania.

  2. Development and cross-species testing of western bluebird (Sialia mexicana) microsatellite primers.

    PubMed

    Ferree, Elise D; Dickinson, Janis L; Kleiber, Danika; Stern, Caitlin A; Haydock, Joey; Stanback, Mark T; Schmidt, Victoria; Eisenberg, Liz; Stolzenburg, Carolyn

    2008-11-01

    Western and eastern bluebirds (Sialia mexicana and S. sialis) are socially monogamous passerines that engage in extra-pair copulations. We obtained microsatellites from S. mexicana and optimized and characterized 15 microsatellite DNA loci in 60 individuals of this species. Primer pairs yielded an average of 13 alleles per locus in western bluebirds (range 3-35 alleles) with an average observed heterozygosity of 0.68 (range 0.27-0.88). All 15 loci also successfully amplified in S. sialis (n = 24), with an average of 11.5 alleles per locus (range 4-26) and an average observed heterozygosity of 0.59 (range 0.22-0.90). © 2008 The Authors. Journal compilation © 2008 Blackwell Publishing Ltd.

  3. Genomic resources for a model in adaptation and speciation research: characterization of the Poecilia mexicana transcriptome

    PubMed Central

    2012-01-01

    Background Elucidating the genomic basis of adaptation and speciation is a major challenge in natural systems with large quantities of environmental and phenotypic data, mostly because of the scarcity of genomic resources for non-model organisms. The Atlantic molly (Poecilia mexicana, Poeciliidae) is a small livebearing fish that has been extensively studied for evolutionary ecology research, particularly because this species has repeatedly colonized extreme environments in the form of caves and toxic hydrogen sulfide containing springs. In such extreme environments, populations show strong patterns of adaptive trait divergence and the emergence of reproductive isolation. Here, we used RNA-sequencing to assemble and annotate the first transcriptome of P. mexicana to facilitate ecological genomics studies in the future and aid the identification of genes underlying adaptation and speciation in the system. Description We provide the first annotated reference transcriptome of P. mexicana. Our transcriptome shows high congruence with other published fish transcriptomes, including that of the guppy, medaka, zebrafish, and stickleback. Transcriptome annotation uncovered the presence of candidate genes relevant in the study of adaptation to extreme environments. We describe general and oxidative stress response genes as well as genes involved in pathways induced by hypoxia or involved in sulfide metabolism. To facilitate future comparative analyses, we also conducted quantitative comparisons between P. mexicana from different river drainages. 106,524 single nucleotide polymorphisms were detected in our dataset, including potential markers that are putatively fixed across drainages. Furthermore, specimens from different drainages exhibited some consistent differences in gene regulation. Conclusions Our study provides a valuable genomic resource to study the molecular underpinnings of adaptation to extreme environments in replicated sulfide spring and cave environments. In

  4. Mg/Ca temperature calibration for the benthic foraminifers Bulimina inflata and Bulimina mexicana

    NASA Astrophysics Data System (ADS)

    Grunert, Patrick; Rosenthal, Yair; Jorissen, Frans; Holbourn, Ann

    2016-04-01

    Bulimina inflata Seguenza 1862 and Bulimina mexicana Cushman 1922 are cosmopolitan, shallow infaunal benthic foraminifers which are common in the fossil record throughout the Neogene and Quaternary. The closely related species share a similar costate shell morphology that differs in the presence or absence of an apical spine. In the present study, we evaluate the temperature dependency of Mg/Ca ratios of these species from an extensive set of core-top samples from the Atlantic and Pacific oceans. The results show no significant offset in Mg/Ca values between B. inflata, B. mexicana, and two other costate morphospecies when present in the same sample. The apparent lack of significant inter-specific/inter-morphotype differences amongst the analysed costate buliminds allows for the combined use of their data-sets for our core-top calibration. Over a bottom-water temperature range of 3-14°C, the Bulimina inflata/mexicana group shows a sensitivity of ˜0.12 mmol/mol/°C which is comparable to the epifaunal Cibicidoides pachyderma and higher than for the shallow infaunal Uvigerina spp., the most commonly used taxa in Mg/Ca-based palaeotemperature reconstruction. B. inflata and B. mexicana might thus be a valuable alternative in mesotrophic settings where many of the commonly used species are diminished or absent, and particularly useful in hypoxic settings where costate buliminds may dominate foraminiferal assemblages. This study was financially supported by the Max-Kade-Foundation and contributes to project P25831-N29 of the Austrian Science Fund (FWF).

  5. Past, Present and Future: Forty Years of Revista Mexicana de Astronomia y Astrofisica

    NASA Astrophysics Data System (ADS)

    Allen, Christine; Torres-Peimbert, Silvia

    2015-08-01

    We cast a retrospective view on 40 years of publishing the Revista Mexicana de Astronomía y Astrofísica, founded in 1974. The journal is peer-reviewed, has appeared regularly since its foundation, and continues to attract original research papers, mostly by Mexican and Latin American authors. We share some musings about the future of our journal, in view of recent developments in the scientific publishing field.

  6. Recurrence of Mexican long-tongued bats (Choeronycteris mexicana) at historical sites in Arizona and New Mexico

    USGS Publications Warehouse

    Cryan, P.M.; Bogan, M.A.

    2003-01-01

    The Mexican long-tongued bat (Choeronycteris mexicana) is 1 of 3 migratory, nectarivorous bats that seasonally occur in the extreme southwestern United States (US); the other 2 species are Leptonycteris curasoae and L. nivalis. Unlike the species of Leptonycteris, C. mexicana is not known to form large maternity colonies and is rarely encountered in groups of more than 12 individuals (Hoffmeister 1986). Possibly because of a propensity to form small roosting groups, the number of C. mexicana historically encountered is relatively low compared to other bat species. Although the range of C. mexicana extends from the southwestern United States into Honduras, less than 1500 individuals have been documented since its discovery in 1844 (Petryszyn and Cockrum In Press). Roosting and habitat needs of C. mexicana are poorly understood and it is unclear how such requirements might influence the apparent scarcity of these bats. Choeronycteris mexicana is known to roost in a variety of situations, typically in shallow caves or near the entrances of more extensive structures (Arroyo-Cabrales et al. 1987). Roost sites have been reported from various vegetation zones, including tropical deciduous forests at southern latitudes (Davis and Russell 1954), but roosts are frequently found in oak-conifer woodlands in the northern part of its range (Hoffmeister 1986). Mexican long-tongued bats are known to feed on nectar, pollen, or fruit of various flowering plants throughout their range (Gardner 1977). Although mutualistic relationships likely exist between C. mexicana and its food plants, very little is known about the role that this species plays as a pollinator or seed disperser of such plants. The identification and elucidation of mutualistic relationships are necessary steps toward effectively conserving ecosystems in the southwestern US (Allen-Wardell et al. 1998). Given the potential importance of C. mexicana as a pollinator and its apparent scarcity in the southwest US, current

  7. Temperature-induced protein secretion by Leishmania mexicana modulates macrophage signalling and function.

    PubMed

    Hassani, Kasra; Antoniak, Elisabeth; Jardim, Armando; Olivier, Martin

    2011-05-03

    Protozoan parasites of genus Leishmania are the causative agents of leishmaniasis. These digenetic microorganisms undergo a marked environmental temperature shift (TS) during transmission from the sandfly vector (ambient temperature, 25-26°C) to the mammalian host (37°C). We have observed that this TS induces a rapid and dramatic increase in protein release from Leishmania mexicana (cutaneous leishmaniasis) within 4 h. Proteomic identification of the TS-induced secreted proteins revealed 72 proteins, the majority of which lack a signal peptide and are thus thought to be secreted via nonconventional mechanisms. Interestingly, this protein release is accompanied by alterations in parasite morphology including an augmentation in the budding of exovesicles from its surface. Here we show that the exoproteome of L. mexicana upon TS induces cleavage and activation of the host protein tyrosine phosphatases, specifically SHP-1 and PTP1-B, in a murine bone-marrow-derived macrophage cell line. Furthermore, translocation of prominent inflammatory transcription factors, namely NF-κB and AP-1 is altered. The exoproteome also caused inhibition of nitric oxide production, a crucial leishmanicidal function of the macrophage. Overall, our results provide strong evidence that within early moments of interaction with the mammalian host, L. mexicana rapidly releases proteins and exovesicles that modulate signalling and function of the macrophage. These modulations can result in attenuation of the inflammatory response and deactivation of the macrophage aiding the parasite in the establishment of infection.

  8. Antispasmodic Effects and Action Mechanism of Essential Oil of Chrysactinia mexicana A. Gray on Rabbit Ileum.

    PubMed

    Zavala-Mendoza, Daniel; Grasa, Laura; Zavala-Sánchez, Miguel Ángel; Pérez-Gutiérrez, Salud; Murillo, María Divina

    2016-06-16

    The Chrysactinia mexicana A. Gray (C. mexicana) plant is used in folk medicine to treat fever and rheumatism; it is used as a diuretic, antispasmodic; and it is used for its aphrodisiac properties. This study investigates the effects of the essential oil of C. mexicana (EOCM) on the contractility of rabbit ileum and the mechanisms of action involved. Muscle contractility studies in vitro in an organ bath to evaluate the response to EOCM were performed in the rabbit ileum. EOCM (1-100 µg·mL(-1)) reduced the amplitude and area under the curve of spontaneous contractions of the ileum. The contractions induced by carbachol 1 µM, potassium chloride (KCl) 60 mM or Bay K8644 1 µM were reduced by EOCM (30 µg·mL(-1)). Apamin 1 µM and charybdotoxin 0.01 µM decreased the inhibition induced by EOCM. The d-cAMP 1 µM decreased the inhibition induced by EOCM. l-NNA 10 µM, Rp-8-Br-PET-cGMPS 1 µM, d,l-propargylglycine 2 mM, or aminooxyacetic acid hemihydrochloride 2 mM did not modify the EOCM effect. In conclusion, EOCM induces an antispasmodic effect and could be used in the treatment of intestinal spasms or diarrhea processes. This effect would be mediated by Ca(2+), Ca(2+)-activated K⁺ channels and cAMP.

  9. Toxicity of atrazine and its bioaccumulation and biodegradation in a green microalga, Chlamydomonas mexicana.

    PubMed

    Kabra, Akhil N; Ji, Min-Kyu; Choi, Jaewon; Kim, Jung Rae; Govindwar, Sanjay P; Jeon, Byong-Hun

    2014-11-01

    This study evaluated the toxicity of herbicide atrazine, along with its bioaccumulation and biodegradation in the green microalga Chlamydomonas mexicana. At low concentration (10 μg L(-1)), atrazine had no profound effect on the microalga, while higher concentrations (25, 50, and 100 μg L(-1)) imposed toxicity, leading to inhibition of cell growth and chlorophyll a accumulation by 22 %, 33 %, and 36 %, and 13 %, 24 %, and 27 %, respectively. Atrazine 96-h EC50 for C. mexicana was estimated to be 33 μg L(-1). Microalga showed a capability to accumulate atrazine in the cell and to biodegrade the cell-accumulated atrazine resulting in 14-36 % atrazine degradation at 10-100 μg L(-1). Increasing atrazine concentration decreased the total fatty acids (from 102 to 75 mg g(-1)) and increased the unsaturated fatty acid content in the microalga. Carbohydrate content increased gradually with the increase in atrazine concentration up to 15 %. This study shows that C. mexicana has the capability to degrade atrazine and can be employed for the remediation of atrazine-contaminated streams.

  10. RNA-seq Analysis of Cold and Drought Responsive Transcriptomes of Zea mays ssp. mexicana L.

    PubMed

    Lu, Xiang; Zhou, Xuan; Cao, Yu; Zhou, Meixue; McNeil, David; Liang, Shan; Yang, Chengwei

    2017-01-01

    The annual Zea mays ssp. mexicana L. is a member of teosinte, a wild relative of the Zea mays spp. mays L. This subspecies has strong growth and regeneration ability, high tiller numbers, high protein and lysine content as well as resistance to many fungal diseases, and it can be effectively used in maize improvement. In this study, we reported a Zea mays ssp. mexicana L. transcriptome by merging data from untreated control (CK), cold (4°C) and drought (PEG2000, 20%) treated plant samples. A total of 251,145 transcripts (N50 = 1,269 bp) and 184,280 unigenes (N50 = 923 bp) were predicted, which code for homologs of near 47% of the published maize proteome. Under cold conditions, 2,232 and 817 genes were up-regulated and down-regulated, respectively, while fewer genes were up-regulated (532) and down-regulated (82) under drought stress, indicating that Zea mays ssp. mexicana L. is more sensitive to the applied cold rather than to the applied drought stresses. Functional enrichment analyses identified many common or specific biological processes and gene sets in response to drought and cold stresses. The ABA dependent pathway, trehalose synthetic pathway and the ICE1-CBF pathway were up-regulated by both stresses. GA associated genes have been shown to differentially regulate the responses to cold in close subspecies in Zea mays. These findings and the identified functional genes can provide useful clues for improving abiotic stress tolerance of maize.

  11. Variation and Genetic Structure in Platanus mexicana (Platanaceae) along Riparian Altitudinal Gradient

    PubMed Central

    Galván-Hernández, Dulce M.; Lozada-García, J. Armando; Flores-Estévez, Norma; Galindo-González, Jorge; Vázquez-Torres, S. Mario

    2015-01-01

    Platanus mexicana is a dominant arboreal species of riparian ecosystems. These ecosystems are associated with altitudinal gradients that can generate genetic differences in the species, especially in the extremes of the distribution. However, studies on the altitudinal effect on genetic variation to riparian species are scarce. In Mexico, the population of P. mexicana along the Colipa River (Veracruz State) grows below its reported minimum altitude range, possibly the lowest where this tree grows. This suggests that altitude might be an important factor in population genetics differentiation. We examined the genetic variation and population structuring at four sites with different altitudes (70, 200, 600 and 1700 m a.s.l.) using ten inter-simple sequence repeats (ISSR) markers. The highest value for Shannon index and Nei’s gene diversity was obtained at 1700 m a.s.l. (He = 0.27, Ne = 1.47, I = 0.42) and polymorphism reached the top value at the middle altitude (% p = 88.57). Analysis of molecular variance (AMOVA) and STRUCTURE analysis indicated intrapopulation genetic differentiation. The arithmetic average (UPGMA) dendrogram identified 70 m a.s.l. as the most genetically distant site. The genetic structuring resulted from limited gene flow and genetic drift. This is the first report of genetic variation in populations of P. mexicana in Mexico. This research highlights its importance as a dominant species, and its ecological and evolutionary implications in altitudinal gradients of riparian ecosystems. PMID:25607732

  12. Transplacental Transmission of Cutaneous Leishmania mexicana Strain in BALB/c Mice

    PubMed Central

    Avila-García, Miroslava; Mancilla-Ramírez, Javier; Segura-Cervantes, Enrique; Farfan-Labonne, Blanca; Ramírez-Ramírez, Alicia; Galindo-Sevilla, Norma

    2013-01-01

    The vertical transmission of leishmaniasis has been reported in species that cause visceral leishmaniasis. However, this condition has scarcely been documented in species that cause cutaneous leishmaniasis. The aim of this study was to determine experimentally whether L. mexicana is transmitted vertically. A control group of BALB/c mice and a group infected with L. mexicana were mated, the gestation was monitored, and females were killed before delivery. Four resorptions (P = 0.023) and eight fetal deaths (P = 0.010) were observed in the infected female group; furthermore, the offspring body weight of the infected group was lower than the body weight of the healthy group (P = 0.009). DNA amplification by polymerase chain reaction (PCR) revealed that all placentas and maternal spleens as well as 39 of 110 fetal spleens obtained from the offspring of infected mothers tested positive for Leishmania. In conclusion, L. mexicana is transmitted transplacentally and causes fetal death, resorption, and reduction in offspring body weight. PMID:23798582

  13. Variation and genetic structure in Platanus mexicana (Platanaceae) along riparian altitudinal gradient.

    PubMed

    Galván-Hernández, Dulce M; Lozada-García, J Armando; Flores-Estévez, Norma; Galindo-González, Jorge; Vázquez-Torres, S Mario

    2015-01-19

    Platanus mexicana is a dominant arboreal species of riparian ecosystems. These ecosystems are associated with altitudinal gradients that can generate genetic differences in the species, especially in the extremes of the distribution. However, studies on the altitudinal effect on genetic variation to riparian species are scarce. In Mexico, the population of P. mexicana along the Colipa River (Veracruz State) grows below its reported minimum altitude range, possibly the lowest where this tree grows. This suggests that altitude might be an important factor in population genetics differentiation. We examined the genetic variation and population structuring at four sites with different altitudes (70, 200, 600 and 1700 m a.s.l.) using ten inter-simple sequence repeats (ISSR) markers. The highest value for Shannon index and Nei's gene diversity was obtained at 1700 m a.s.l. (He = 0.27, Ne = 1.47, I = 0.42) and polymorphism reached the top value at the middle altitude (% p = 88.57). Analysis of molecular variance (AMOVA) and STRUCTURE analysis indicated intrapopulation genetic differentiation. The arithmetic average (UPGMA) dendrogram identified 70 m a.s.l. as the most genetically distant site. The genetic structuring resulted from limited gene flow and genetic drift. This is the first report of genetic variation in populations of P. mexicana in Mexico. This research highlights its importance as a dominant species, and its ecological and evolutionary implications in altitudinal gradients of riparian ecosystems.

  14. Leishmania mexicana Infection Induces IgG to Parasite Surface Glycoinositol Phospholipids that Can Induce IL-10 in Mice and Humans

    PubMed Central

    Buxbaum, Laurence U.

    2013-01-01

    Infection with the intracellular protozoan parasite Leishmania mexicana causes chronic disease in C57BL/6 mice, in which cutaneous lesions persist for many months with high parasite burdens (107–108 parasites). This chronic disease process requires host IL-10 and FcγRIII. When Leishmania amastigotes are released from cells, surface-bound IgG can induce IL-10 and suppress IL-12 production from macrophages. These changes decrease IFN-γ from T cells and nitric oxide production in infected cells, which are both required for Leishmania control. However, antibodies targets and the kinetics of antibody production are unknown. Several groups have been unsuccessful in identifying amastigote surface proteins that bind IgG. We now show that glycoinositol phospholipids (GIPLs) of L. mexicana are recognized by mouse IgG1 by 6 weeks of infection, with a rapid increase between 12 and 16 weeks, consistent with the timing of chronic disease in C57BL/6 mice vs. healing in FcγRIII-deficient mice. A single prominent spot on TLC is recognized by IgG, and the glycolipid is a glycosyl phosphatidylinositol containing a branched mannose structure. We show that the lipid structure of the GIPL (the sn-2 fatty acid) is required for antibody recognition. This GIPL is abundant in L. mexicana amastigotes, rare in stationary-phase promastigotes, and absent in L. major, consistent with a role for antibodies to GIPLs in chronic disease. A mouse monoclonal anti-GIPL IgG recognizes GIPLs on the parasite surface, and induces IL-10 from macrophages. The current work also extends this mouse analysis to humans, finding that L. mexicana-infected humans with localized and diffuse cutaneous leishmaniasis have antibodies that recognize GIPLs, can bind to the surface of amastigotes, and can induce IL-10 from human monocytes. Further characterization of the target glycolipids will have important implications for drug and vaccine development and will elucidate the poorly understood role of glycolipids in

  15. Infectivity of Leishmania mexicana Is Associated with Differential Expression of Protein Kinase C-Like Triggered during a Cell-Cell Contact

    PubMed Central

    Alvarez-Rueda, Nidia; Biron, Marlène; Le Pape, Patrice

    2009-01-01

    Mammalian host cell invasion by Leishmania is a complex process in which various parasite and host cell components interact, triggering the activation of signaling cascades in both cells. Little is known regarding PKC biological functions in Leishmania sp. during parasite-macrophage interaction. PKC-like enzyme was first identified in homogenates and membrane fraction of L. mexicana stationary promastigotes by immunoblot. PKC-like enzyme activity was then detected in cell homogenates but also on intact promastigotes showing for the first time the presence of an ecto-PKC dependent on Ca2+/phosphatidylserine for activation. This ecto-PKC was activated with phorbol myristate acetate (PMA) and inhibited by RO-32-0432, a selective PKCαβIε bisindolylmaleimide inhibitor. Interestingly, the Leishmania PKC- activity was higher in the infective stationary than in non-infective logarithmic stage. Then, promastigotes at different stages of time proliferation curve were used in order to identify the role of PKC-like during macrophage invasion. After attachment to macrophages, PKC-like is over-expressed in promastigotes at the 6th culture day but also at the 4th day of culture corresponding to the maximal infection capacity. An antibody microarray for MAPK and PKC corroborate the Leishmania PKC-like over-expression during contact with macrophages. Pretreatment with RO-32-0432 inhibitor reduced the number of infected macrophages and the parasite burden. These data suggest for the first time a direct link between PKC expression level and infectivity, and provide evidence that PKC-like plays a critical role in attachment and in the internalization steps involved in the invasion process. PMID:19851504

  16. Biodegradation of carbamazepine using freshwater microalgae Chlamydomonas mexicana and Scenedesmus obliquus and the determination of its metabolic fate.

    PubMed

    Xiong, Jiu-Qiang; Kurade, Mayur B; Abou-Shanab, Reda A I; Ji, Min-Kyu; Choi, Jaeyoung; Kim, Jong Oh; Jeon, Byong-Hun

    2016-04-01

    This study evaluated the toxicity and cellular stresses of carbamazepine (CBZ) on Chlamydomonas mexicana and Scenedesmus obliquus, and its biodegradation by both microalgal species. The growth of both microalgal species decreased with increase of CBZ concentration. The growth of S. obliquus was significantly inhibited (97%) at 200 mg CBZ L(-1), as compared to the control after 10days; whereas, C. mexicana showed 30% inhibition at the same experimental conditions. Biochemical characteristics including total chlorophyll, carotenoid contents and enzyme activities (SOD and CAT) for both species were affected by CBZ at relatively high concentration. C. mexicana and S. obliquus could achieve a maximum of 35% and 28% biodegradation of CBZ, respectively. Two metabolites (10,11-dihydro-10,11-expoxycarbamazepine and n-hydroxy-CBZ) were identified by UPLC-MS, as a result of CBZ biodegradation by C. mexicana. This study demonstrated that C. mexicana was more tolerant to CBZ and could be used for treatment of CBZ contaminated wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Anxiolytic-like effect of ethanolic extract of Argemone mexicana and its alkaloids in Wistar rats

    PubMed Central

    Arcos-Martínez, Aideé Itzel; Muñoz-Muñiz, Omar David; Domínguez-Ortiz, Miguel Ángel; Saavedra-Vélez, Margarita Virginia; Vázquez-Hernández, Maribel; Alcántara-López, María Gabriela

    2016-01-01

    Objective: Argemone mexicana is a Papaveracea plant; some reports have shown their antibacterial, anti-cancer, sedative and probably anti-anxiety properties. From their aerial parts, flavonoids and alkaloids have been isolated, which are intrinsically related to some actions on the central nervous system. The aim of this study was to evaluate the anxiolytic-like effects of the plant, using its ethanolic extract and alkaloid-enriched extract obtained from fresh leaves. Material and Methods: Phytochemical screening was carried out together with evaluation of antioxidant capacity and the enrichment of alkaloids present in the extract. Subsequently, 100 and 200 mg/kg doses of ethanolic extract and alkaloid-enriched extract (200 µg/kg) were intraperitoneally administered to female Wistar rats, which were exposed to elevated plus maze (EPM) test. Picrotoxin (1 mg/kg), a non-competitive gamma-aminobutyric acid A (GABAA) chloride channel antagonist, was used in experimental procedures to evaluate if this receptor is involved in the anxiolytic-like effects of A. mexicana. To discard motor effects associated with the treatments, the rats were evaluated by the locomotor activity test. Results: Only the ethanolic extract at 200 mg/kg and alkaloid-enriched extract (200 µg/kg) produced anxiolytic-like effects similarly to diazepam 2 mg/kg on EPM test, without affecting locomotor activity. Meanwhile, the administration of picrotoxin blocked anti-anxiety effect of alkaloid-enriched extract of the plant. Conclusion: These results showed that A. mexicana is a potential anxiolytic agent and we suggest that this effect is mediated by the GABAA receptor. These effects are related to the presence of alkaloids. PMID:27516989

  18. RNA-seq Analysis of Cold and Drought Responsive Transcriptomes of Zea mays ssp. mexicana L.

    PubMed Central

    Lu, Xiang; Zhou, Xuan; Cao, Yu; Zhou, Meixue; McNeil, David; Liang, Shan; Yang, Chengwei

    2017-01-01

    The annual Zea mays ssp. mexicana L. is a member of teosinte, a wild relative of the Zea mays spp. mays L. This subspecies has strong growth and regeneration ability, high tiller numbers, high protein and lysine content as well as resistance to many fungal diseases, and it can be effectively used in maize improvement. In this study, we reported a Zea mays ssp. mexicana L. transcriptome by merging data from untreated control (CK), cold (4°C) and drought (PEG2000, 20%) treated plant samples. A total of 251,145 transcripts (N50 = 1,269 bp) and 184,280 unigenes (N50 = 923 bp) were predicted, which code for homologs of near 47% of the published maize proteome. Under cold conditions, 2,232 and 817 genes were up-regulated and down-regulated, respectively, while fewer genes were up-regulated (532) and down-regulated (82) under drought stress, indicating that Zea mays ssp. mexicana L. is more sensitive to the applied cold rather than to the applied drought stresses. Functional enrichment analyses identified many common or specific biological processes and gene sets in response to drought and cold stresses. The ABA dependent pathway, trehalose synthetic pathway and the ICE1-CBF pathway were up-regulated by both stresses. GA associated genes have been shown to differentially regulate the responses to cold in close subspecies in Zea mays. These findings and the identified functional genes can provide useful clues for improving abiotic stress tolerance of maize. PMID:28223998

  19. Nocardia mexicana sp. nov., a New Pathogen Isolated from Human Mycetomas

    PubMed Central

    Rodríguez-Nava, Verónica; Couble, Andrée; Molinard, Claudie; Sandoval, Horacio; Boiron, Patrick; Laurent, Frédéric

    2004-01-01

    Three isolates collected from human mycetomas and showing an unusual brownish purple pigmentation on Bennett agar plates were analyzed by a polyphasic taxonomic approach, including morphological, biochemical, physiological, and chemotaxonomic properties coupled with genomic and phylogenetic analysis. It clearly appeared that these microorganisms were distinct from their closest phenotypic and genetic match, the most related species according to 16S rRNA gene sequence analysis being Nocardia pseudobrasiliensis. The data obtained indicated that the three clinical strains should be recognized as a new species for which the name Nocardia mexicana sp. nov. is proposed. PMID:15472305

  20. Isolation of cDNA from Jacaratia mexicana encoding a mexicain-like cysteine protease gene.

    PubMed

    Ramos-Martínez, Erick M; Herrera-Ramírez, Alejandra C; Badillo-Corona, Jesús Agustín; Garibay-Orijel, Claudio; González-Rábade, Nuria; Oliver-Salvador, María Del Carmen

    2012-07-01

    Cysteine proteases (CPs) from the C1 family, which are similar to papain, can be found in animals and plants, as well as some viruses and prokaryotes. These enzymes have diverse physiological functions and are thus very attractive for science and industry. Jacaratia mexicana, a member of the Caricaceae plant family, contains several CPs, the principal being mexicain, found to favorably compete against papain for many industrial applications due to its high stability and specific activity. In this study, leaves of J. mexicana were used to isolate a CP-coding gene, similar to those that code for mexicain and chymomexicain. By using rapid amplification of cDNA ends (RACE) as well as oligonucleotide design from papain-like conserved amino acids (aa), a sequence of 1404 bp consisting of a 5' terminal untranslated region (UTR) of 153 bp, a 3' terminal UTR of 131 bp, with a polyadenylation (poly(A)) signal sequence and a poly(A) tail, and an open reading frame (ORF) of 1046 bp, was obtained by overlapping three partial sequences. Two full-length cDNA sequences that encode for mexicain-like proteases were cloned from mRNA (JmCP4 and JmCP5). JmCP4 is predicted to have an ORF of 1044 bp, which codifies for polypeptides that have a 26 aa signal peptide region, a 108 aa propeptide region and a mature enzyme of 214 aa. A 969 bp fragment (JmCP5) encodes for a partial sequence of a CP gene, without the signal peptide region but with a full-length propeptide region. The sequence analysis showed that this protease presented a high similarity to other plant CPs from J. mexicana, Vasconcellea cundinamarcensis, Vasconcellea stipulata, and Carica papaya, among others, mainly at the conserved catalytic site. Obtaining the sequence of this CP gene from J. mexicana provides an alternative for production in a standard system and could be an initial step towards the commercialization of this enzyme.

  1. Lupane triterpenes with a δ-lactone at ring E, from Lippia mexicana.

    PubMed

    Maldonado, Emma; Díaz-Arumir, Humberto; Toscano, R Alfredo; Martínez, Mahinda

    2010-11-29

    Three new lupane-type triterpenes, lippiolide (1), lippiolidolic acid (2), and lippiolic acid (3), were isolated from aerial parts of Lippia mexicana. Compounds 1 and 2 exhibited a δ-lactone at ring E. The known cycloartane triterpene 5 was also isolated. The structures of these compounds were established on the basis of spectroscopic data and chemical reactions, and the structure of compound 1 was confirmed by X-ray diffraction analysis. Anti-inflammatory activity of compounds 1, 3, and 5 was evaluated in the TPA-induced ear mouse edema model. Lupanes 1 and 3 were more active than cycloartane 5.

  2. Two pharyngodonid nematodes, Alaeuris mexicana n. sp. and Ozolaimus ctenosauri, from the iguanid lizard Ctenosaura pectinata from Nayarit, Mexico.

    PubMed

    Moravec, F; Salgado-Maldonado, G; Mayen-Peña, E

    1996-12-01

    Two species of nematodes, Alaeuris mexicana n. sp. and Ozolaimus ctenosauri Caballero, 1938, were found in the iguanid lizard Ctenosaura pectinata (Wiegmann) from Aguamilpa, Nayarit, central Mexico (Pacific region). The new species, A. mexicana, differs from all congeners mainly in the length of the spicule (0.228-0.233 mm) and in the shape and size of the tail and caudal alae. Ozolaimus ctenosauri (syn. Ozolaimus prolixa Caballero et Cerecero, 1943) is considered a valid species parasitic in Ctenosaura spp. Scanning electron microscopic studies of both species revealed substantial differences in the structure of the mouth, which were used for the separation of the closely related genera Ozolaimus and Alaeuris.

  3. Triatoma mexicana (Hemiptera: Reduviidae) in Guanajuato, Mexico: house infestation and seasonal variation.

    PubMed

    Salazar Schettino, Paz María; Rosales Piña, José Santiago; Rojas Wastavino, Gloria; Cabrera Bravo, Margarita; Vences Blanco, Mauro; López Cárdenas, Jorge

    2007-11-01

    Triatoma mexicana was described by Herrich-Schaeffer in 1848. In 1940, a male specimen was found in Hidalgo. In 1970, this species was recorded in the state of Queretaro. Later, it was registered in Guanajuato and San Luis Potosi. In the present paper we performed an investigation in 545 dwellings from three counties in the state of Guanajuato, Mexico, from March 2003 to May 2004. The search and capture of triatomines were seasonally performed indoors and outdoors. Entomological indexes were calculated. The risk and no risk relations between triatomine presence and housing construction materials were analyzed. Fourteen triatomines were collected indoors and 151 outdoors. The vectors were collected in houses built with either risky and non-risky materials. Adults go indoors but do not settle there, hence, no relationship was found between the building materials and infestation of houses. Conventional interventions like house improvement or insecticide spraying are not efficient for the control of T. mexicana, because its developmental cycle is accomplished outdoors in the area surrounding the houses.

  4. Experience, but not distance, influences the recruitment precision in the stingless bee Scaptotrigona mexicana

    NASA Astrophysics Data System (ADS)

    Sánchez, Daniel; Kraus, F. Bernhard; Hernández, Manuel De Jesús; Vandame, Rémy

    2007-07-01

    Recruitment precision, i.e. the proportion of recruits that reach an advertised food source, is a crucial adaptation of social bees to their environment. Studies with honeybees showed that recruitment precision is not a fixed feature, but it may be enhanced by factors like experience and distance. However, little is known regarding the recruitment precision of stingless bees. Hence, in this study, we examined the effects of experience and spatial distance on the precision of the food communication system of the stingless bee Scaptotrigona mexicana. We conducted the experiments by training bees to a three-dimensional artificial patch at several distances from the colony. We recorded the choices of individual recruited foragers, either being newcomers (foragers without experience with the advertised food source) or experienced (foragers that had previously visited the feeder). We found that the average precision of newcomers (95.6 ± 2.61%) was significantly higher than that of experienced bees (80.2 ± 1.12%). While this might seem counter-intuitive on first sight, this “loss” of precision can be explained by the tendency of experienced recruits to explore nearby areas to find new rewarding food sources after they had initially learned the exact location of the food source. Increasing the distance from the colony had no significant effect on the precision of the foraging bees. Thus, our data show that experience, but not the distance of the food source, affected the patch precision of S. mexicana foragers.

  5. Experience, but not distance, influences the recruitment precision in the stingless bee Scaptotrigona mexicana.

    PubMed

    Sánchez, Daniel; Kraus, F Bernhard; Hernández, Manuel de Jesús; Vandame, Rémy

    2007-07-01

    Recruitment precision, i.e. the proportion of recruits that reach an advertised food source, is a crucial adaptation of social bees to their environment. Studies with honeybees showed that recruitment precision is not a fixed feature, but it may be enhanced by factors like experience and distance. However, little is known regarding the recruitment precision of stingless bees. Hence, in this study, we examined the effects of experience and spatial distance on the precision of the food communication system of the stingless bee Scaptotrigona mexicana. We conducted the experiments by training bees to a three-dimensional artificial patch at several distances from the colony. We recorded the choices of individual recruited foragers, either being newcomers (foragers without experience with the advertised food source) or experienced (foragers that had previously visited the feeder). We found that the average precision of newcomers (95.6 +/- 2.61%) was significantly higher than that of experienced bees (80.2 +/- 1.12%). While this might seem counter-intuitive on first sight, this "loss" of precision can be explained by the tendency of experienced recruits to explore nearby areas to find new rewarding food sources after they had initially learned the exact location of the food source. Increasing the distance from the colony had no significant effect on the precision of the foraging bees. Thus, our data show that experience, but not the distance of the food source, affected the patch precision of S. mexicana foragers.

  6. Seroprevalence of Trypanosoma cruzi and Leishmania mexicana in free-ranging howler monkeys in southeastern Mexico.

    PubMed

    Rovirosa-Hernández, María de Jesús; Cortes-Ortíz, Liliana; García-Orduña, Francisco; Guzmán-Gómez, Daniel; López-Monteon, Aracely; Caba, Mario; Ramos-Ligonio, Angel

    2013-02-01

    Natural infection of wild mammals by protozoa parasites is quite common in nature. For Neotropical Primates different infections of parasites that are etiological agent of disease in human have been identified. In particular, infections by Trypanosoma cruzi and Leishmania sp., have been reported for some New World primate species, but there are no reports of infection with these parasites in any primate species in Mexico. A serological study was conducted on two howler monkey species (Alouatta pigra and A. palliata) from the Mexican states of Campeche and Tabasco. A total of 55 serum samples (20 samples from A. pigra, 20 samples from A. palliata, and 15 samples from semifree ranging A. palliata of Los Tuxtlas, Veracruz as negative controls) were analyzed for the detection of immunoglobulin G antibodies against T. cruzi and Leishmania mexicana through enzyme linked immunosorbent assay test, indirect immunofluorescence assay and Western blot. The overall prevalence of antibodies in howler monkeys was 17.5% for T. cruzi and 30% for L. mexicana. Our results also indicate that A. pigra is more susceptible to develop leishmaniasis than A. palliata. Finally, the finding of positive serology in these primates should be given serious consideration for public health, given the potential role of these primate species as wild reservoirs for these diseases and the increasing contact of monkeys with human populations due to habitat loss and fragmentation. © 2012 Wiley Periodicals, Inc.

  7. Identification of semicarbazones, thiosemicarbazones and triazine nitriles as inhibitors of Leishmania mexicana cysteine protease CPB.

    PubMed

    Schröder, Jörg; Noack, Sandra; Marhöfer, Richard J; Mottram, Jeremy C; Coombs, Graham H; Selzer, Paul M

    2013-01-01

    Cysteine proteases of the papain superfamily are present in nearly all eukaryotes. They play pivotal roles in the biology of parasites and inhibition of cysteine proteases is emerging as an important strategy to combat parasitic diseases such as sleeping sickness, Chagas' disease and leishmaniasis. Homology modeling of the mature Leishmania mexicana cysteine protease CPB2.8 suggested that it differs significantly from bovine cathepsin B and thus could be a good drug target. High throughput screening of a compound library against this enzyme and bovine cathepsin B in a counter assay identified four novel inhibitors, containing the warhead-types semicarbazone, thiosemicarbazone and triazine nitrile, that can be used as leads for antiparasite drug design. Covalent docking experiments confirmed the SARs of these lead compounds in an effort to understand the structural elements required for specific inhibition of CPB2.8. This study has provided starting points for the design of selective and highly potent inhibitors of L. mexicana cysteine protease CPB that may also have useful efficacy against other important cysteine proteases.

  8. The histopathology of cutaneous leishmaniasis due to Leishmania (Leishmania) mexicana in the Yucatan peninsula, Mexico.

    PubMed

    Andrade-Narvaez, Fernando J; Medina-Peralta, Salvador; Vargas-Gonzalez, Alberto; Canto-Lara, Silvia B; Estrada-Parra, Sergio

    2005-01-01

    Localized Cutaneous Leishmaniasis (LCL) known as "chiclero's ulcer" in southeast Mexico, was described by SEIDELIN in 1912. Since then the sylvatic region of the Yucatan peninsula has been documented as an endemic focus of LCL. This study of 73 biopsies from parasitological confirmed lesions of LCL cases of Leishmania (Leishmania) mexicana infection was undertaken: 1) to examine host response at tissue level; and 2) to relate manifestations of this response to some characteristics of clinical presentation. Based on Magalhães' classification we found that the most common pattern in our LCL cases caused by L. (L.) mexicana was predominantly characterized by the presence of unorganized granuloma without necrosis, (43.8%). Another important finding to be highlighted is the fact that in 50/73 (68.5%) parasite identification was positive. There was direct relation between the size of the lesion and time of evolution (rs = 0.3079, p = 0.03), and inverse correlation between size of the lesion and abundance of amastigotes (rs = -0.2467, p = 0.03). In view of the complexity of clinical and histopathological findings, cell-mediated immune response of the disease related to clinical and histopathological features, as so genetic background should be studied.

  9. Identification of Semicarbazones, Thiosemicarbazones and Triazine Nitriles as Inhibitors of Leishmania mexicana Cysteine Protease CPB

    PubMed Central

    Schröder, Jörg; Noack, Sandra; Marhöfer, Richard J.; Mottram, Jeremy C.; Coombs, Graham H.; Selzer, Paul M.

    2013-01-01

    Cysteine proteases of the papain superfamily are present in nearly all eukaryotes. They play pivotal roles in the biology of parasites and inhibition of cysteine proteases is emerging as an important strategy to combat parasitic diseases such as sleeping sickness, Chagas’ disease and leishmaniasis. Homology modeling of the mature Leishmania mexicana cysteine protease CPB2.8 suggested that it differs significantly from bovine cathepsin B and thus could be a good drug target. High throughput screening of a compound library against this enzyme and bovine cathepsin B in a counter assay identified four novel inhibitors, containing the warhead-types semicarbazone, thiosemicarbazone and triazine nitrile, that can be used as leads for antiparasite drug design. Covalent docking experiments confirmed the SARs of these lead compounds in an effort to understand the structural elements required for specific inhibition of CPB2.8. This study has provided starting points for the design of selective and highly potent inhibitors of L. mexicana cysteine protease CPB that may also have useful efficacy against other important cysteine proteases. PMID:24146999

  10. Vegetation patches improve the establishment of Salvia mexicana seedlings by modifying microclimatic conditions.

    PubMed

    Mendoza-Hernández, Pedro E; Rosete-Rodríguez, Alejandra; Sánchez-Coronado, María E; Orozco, Susana; Pedrero-López, Luis; Méndez, Ignacio; Orozco-Segovia, Alma

    2014-07-01

    Human disturbance has disrupted the dynamics of plant communities. To restore these dynamics, we could take advantage of the microclimatic conditions generated by remaining patches of vegetation and plastic mulch. These microclimatic conditions might have great importance in restoring disturbed lava fields located south of Mexico City, where the rock is exposed and the soil is shallow. We evaluated the effects of both the shade projected by vegetation patches and plastic mulch on the mean monthly soil surface temperature (Tss) and photosynthetic photon flux density (PPFD) and on the survival and growth of Salvia mexicana throughout the year. This species was used as a phytometer of microsite quality. Shade reduced the T ss to a greater extent than mulch did. Both survival and growth were enhanced by shade and mulch, and the PPFD was related with seedling growth. During the dry season, plant biomass was lost, and there was a negative effect of PPFD on plant growth. At micro-meteorological scales, the use of shade projected by patches of vegetation and mulch significantly reduced the mortality of S. mexicana and enhanced its growth. Survival and growth of this plant depended on the environmental quality of microsites on a small scale, which was determined by the environmental heterogeneity of the patches and the landscape. For plant restoration, microsite quality must be evaluated on small scales, but on a large scale it may be enough to take advantage of landscape shade dynamics and the use of mulch to increase plant survival and growth.

  11. Natural products as inhibitors of recombinant cathepsin L of Leishmania mexicana.

    PubMed

    de Sousa, Lorena R F; Wu, Hongmei; Nebo, Liliane; Fernandes, João B; da Silva, Maria F das G F; Kiefer, Werner; Schirmeister, Tanja; Vieira, Paulo C

    2015-09-01

    Cysteine proteinases (cathepsins) from Leishmania spp. are promising molecular targets against leishmaniasis. Leishmania mexicana cathepsin L is essential in the parasite life cycle and a pivotal in virulence factor in mammals. Natural products that have been shown to display antileishmanial activity were screened as part of our ongoing efforts to design inhibitors against the L. mexicana cathepsin L-like rCPB2.8. Among them, agathisflavone (1), tetrahydrorobustaflavone (2), 3-oxo-urs-12-en-28-oic acid (3), and quercetin (4) showed significant inhibitory activity on rCPB2.8 with IC50 values ranging from 0.43 to 18.03 µM. The mechanisms of inhibition for compounds 1-3, which showed Ki values in the low micromolar range (Ki = 0.14-1.26 µM), were determined. The biflavone 1 and the triterpene 3 are partially noncompetitive inhibitors, whereas biflavanone 2 is an uncompetitive inhibitor. The mechanism of action established for these leishmanicidal natural products provides a new outlook in the search for drugs against Leishmania. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Associations Between Macroinvertebrates and Paralemanea mexicana, an Endemic Freshwater Red Alga from a Mountain River in Central Mexico.

    PubMed

    Caro-Borrero, A; Carmona-Jiménez, J

    2016-12-01

    Macrophytes are common inhabitants of lotic environments and, depending on their morphological traits, possess adaptations that provide shelter to aquatic invertebrates against strong river flow and predators. They may also be used as a food source by macroinvertebrates. The main goal of this study was to determine the relationship between the red alga Paralemanea mexicana and its role as a shelter and/or food source for lotic macroinvertebrates. We also conducted research on the role of microhabitat and morphological variations of the alga in determining macroinvertebrate taxon abundance, diversity, and functional group composition in a high-current velocity river. Results showed that changes in cover and morphology of P. mexicana were mostly correlated with river current velocity, irradiance, and seasonal variation. In turn, these were related to changes in abundance and diversity of the associated macroinvertebrate community. In addition, six macroinvertebrate functional feeding groups were evaluated for associations with the red alga: filtering and gathering collectors, piercers, scrapers, herbivore shredders, and predators. The results showed that the Trichoptera Hydroptilidae genera Ochrotrichia and Metrichia use P. mexicana as a food source and case-building material. The Trichoptera Glossosomatidae Mortoniella uses the alga as a substrate. The biotic interactions between P. mexicana and associated macroinvertebrates reveal the importance of macrophytes as purveyors of substrate, as food and shelter for macroinvertebrates, and also as promoters of macroinvertebrate community diversity. In addition, it was shown that macroinvertebrate herbivory likely facilitates vegetative propagation of the red alga through increased release and germination of carpospores and new gametophytes.

  13. Prosexual Effect of Chrysactinia mexicana A. Gray (Asteraceae), False Damiana, in a Model of Male Sexual Behavior.

    PubMed

    Estrada-Reyes, R; Ferreyra-Cruz, O A; Jiménez-Rubio, G; Hernández-Hernández, O T; Martínez-Mota, L

    Chrysactinia mexicana A. Gray (Asteraceae) and Turnera diffusa Willd (Turneraceae) are employed in traditional medicine as aphrodisiacs; however, there is no scientific evidence supporting the prosexual properties of C. mexicana. The aim of this study was to determine whether an aqueous extract of C. mexicana (Cm) stimulates rat male sexual behavior in the sexual exhaustion paradigm. Sexually exhausted (SExh) male rats were treated with Cm (80, 160, and 320 mg/kg), an aqueous extract of T. diffusa (Td), or yohimbine. The sexual exhaustion state in the control group was characterized by a low percentage of males exhibiting mounts, intromissions, and ejaculations and no males demonstrating mating behavior after ejaculation. Cm (320 mg/kg), Td, or yohimbine significantly increased the proportion of SExh rats that ejaculated and resumed copulation after ejaculation. In males that exhibited reversal of sexual exhaustion, Cm (320 mg/kg) improved sexual performance by reducing the number of intromissions and shrinking ejaculation latency. The effects of treatments on sexual behavior were not related with alterations in general locomotion. In conclusion, the prosexual effects of Cm, as well as those of Td, are established at a central level, which supports the traditional use of C. mexicana for stimulating sexual activity.

  14. Prosexual Effect of Chrysactinia mexicana A. Gray (Asteraceae), False Damiana, in a Model of Male Sexual Behavior

    PubMed Central

    Estrada-Reyes, R.; Ferreyra-Cruz, O. A.

    2016-01-01

    Chrysactinia mexicana A. Gray (Asteraceae) and Turnera diffusa Willd (Turneraceae) are employed in traditional medicine as aphrodisiacs; however, there is no scientific evidence supporting the prosexual properties of C. mexicana. The aim of this study was to determine whether an aqueous extract of C. mexicana (Cm) stimulates rat male sexual behavior in the sexual exhaustion paradigm. Sexually exhausted (SExh) male rats were treated with Cm (80, 160, and 320 mg/kg), an aqueous extract of T. diffusa (Td), or yohimbine. The sexual exhaustion state in the control group was characterized by a low percentage of males exhibiting mounts, intromissions, and ejaculations and no males demonstrating mating behavior after ejaculation. Cm (320 mg/kg), Td, or yohimbine significantly increased the proportion of SExh rats that ejaculated and resumed copulation after ejaculation. In males that exhibited reversal of sexual exhaustion, Cm (320 mg/kg) improved sexual performance by reducing the number of intromissions and shrinking ejaculation latency. The effects of treatments on sexual behavior were not related with alterations in general locomotion. In conclusion, the prosexual effects of Cm, as well as those of Td, are established at a central level, which supports the traditional use of C. mexicana for stimulating sexual activity. PMID:27656650

  15. Aqueous and Methanolic Extracts of Caulerpa mexicana Suppress Cell Migration and Ear Edema Induced by Inflammatory Agents

    PubMed Central

    Bitencourt, Mariana Angelica Oliveira; Dantas, Gracielle Rodrigues; Lira, Daysianne Pereira; Barbosa-Filho, Jose Maria; de Miranda, George Emmanuel Cavalcanti; de Oliveira Santos, Barbara Viviana; Souto, Janeusa Trindade

    2011-01-01

    The regulation of the inflammatory response is essential to maintaining homeostasis. Several studies have investigated new drugs that may contribute to avoiding or minimizing excessive inflammatory process. The aim of this study was to evaluate the effect of extracts of green algae Caulerpa mexicana on models inflammation. In mice, the inflammatory peritonitis model is induced by zymosan. Previous treatment of mice with aqueous and methanolic extracts of C. mexicana was able to suppress the cell migration to the peritoneal cavity, in a time-dependent but not in a dose-dependent manner. The treatment of mice with C. mexicana extracts also decreased the xylene-induced ear edema, exerting strong inhibitory leukocyte migration elicited by zymosan into the air pouch. We concluded that administration of the extracts resulted in a reduction of cell migration to different sites as well as a decrease in edema formation induced by chemical irritants. This study demonstrates for the first time the anti-inflammatory effect of aqueous and methanolic extracts from the green marine algae Caulerpa mexicana. PMID:21892348

  16. Aqueous and methanolic extracts of Caulerpa mexicana suppress cell migration and ear edema induced by inflammatory agents.

    PubMed

    Bitencourt, Mariana Angelica Oliveira; Dantas, Gracielle Rodrigues; Lira, Daysianne Pereira; Barbosa-Filho, Jose Maria; de Miranda, George Emmanuel Cavalcanti; Santos, Barbara Viviana de Oliveira; Souto, Janeusa Trindade

    2011-01-01

    The regulation of the inflammatory response is essential to maintaining homeostasis. Several studies have investigated new drugs that may contribute to avoiding or minimizing excessive inflammatory process. The aim of this study was to evaluate the effect of extracts of green algae Caulerpa mexicana on models inflammation. In mice, the inflammatory peritonitis model is induced by zymosan. Previous treatment of mice with aqueous and methanolic extracts of C. mexicana was able to suppress the cell migration to the peritoneal cavity, in a time-dependent but not in a dose-dependent manner. The treatment of mice with C. mexicana extracts also decreased the xylene-induced ear edema, exerting strong inhibitory leukocyte migration elicited by zymosan into the air pouch. We concluded that administration of the extracts resulted in a reduction of cell migration to different sites as well as a decrease in edema formation induced by chemical irritants. This study demonstrates for the first time the anti-inflammatory effect of aqueous and methanolic extracts from the green marine algae Caulerpa mexicana.

  17. Revista Mexicana de Astronomía y Astrofísica, a real option for astronomical publication

    NASA Astrophysics Data System (ADS)

    Torres-Peimbert, S.; Allen, C.

    2011-10-01

    We present statistical data about the Revista Mexicana de Astronomía y Astrofísica. We consider that this journal is well positioned in the international astronomical literature. Similarly we present information about the Serie de Conferencias, which also has a wide level of acceptance by the astronomical community.

  18. Disease Severity in Patients Infected with Leishmania mexicana Relates to IL-1β

    PubMed Central

    Fernández-Figueroa, Edith A.; Rangel-Escareño, Claudia; Espinosa-Mateos, Valeria; Carrillo-Sánchez, Karol; Salaiza-Suazo, Norma; Carrada-Figueroa, Georgina; March-Mifsut, Santiago; Becker, Ingeborg

    2012-01-01

    Leishmania mexicana can cause both localized (LCL) and diffuse (DCL) cutaneous leishmaniasis, yet little is known about factors regulating disease severity in these patients. We analyzed if the disease was associated with single nucleotide polymorphisms (SNPs) in IL-1β (−511), CXCL8 (−251) and/or the inhibitor IL-1RA (+2018) in 58 Mexican mestizo patients with LCL, 6 with DCL and 123 control cases. Additionally, we analyzed the in vitro production of IL-1β by monocytes, the expression of this cytokine in sera of these patients, as well as the tissue distribution of IL-1β and the number of parasites in lesions of LCL and DCL patients. Our results show a significant difference in the distribution of IL-1β (−511 C/T) genotypes between patients and controls (heterozygous OR), with respect to the reference group CC, which was estimated with a value of 3.23, 95% CI = (1.2, 8.7) and p-value = 0.0167), indicating that IL-1β (−511 C/T) represents a variable influencing the risk to develop the disease in patients infected with Leishmania mexicana. Additionally, an increased in vitro production of IL-1β by monocytes and an increased serum expression of the cytokine correlated with the severity of the disease, since it was significantly higher in DCL patients heavily infected with Leishmania mexicana. The distribution of IL-1β in lesions also varied according to the number of parasites harbored in the tissues: in heavily infected LCL patients and in all DCL patients, the cytokine was scattered diffusely throughout the lesion. In contrast, in LCL patients with lower numbers of parasites in the lesions, IL-1β was confined to the cells. These data suggest that IL-1β possibly is a key player determining the severity of the disease in DCL patients. The analysis of polymorphisms in CXCL8 and IL-1RA showed no differences between patients with different disease severities or between patients and controls. PMID:22629474

  19. Argemone mexicana: A Boon to Medicinal and Pharmacological Approaches in Current Scenario.

    PubMed

    Nancy, A; Praveena, A

    2017-08-30

    Nature is God's gift to human beings. Natural products are a source of new chemical diversity and are the choice of today's world. Nature itself gives remedy to all our health problems. The sources of natural product are plants, animals and microorganisms. Among them plant and its products are more reliable for its renewability and therefore, considered as fortunate thing for human welfare. Our traditional system of medicine which has been followed by our ancestors has its own impact on human life. Due to the inadequate knowledge many plant derived products (drugs) has not yet been explored to the society. We are having many side effects and long term complications in synthetic drugs. Our aim is to mine the precious data about the plant Argemone mexicana. Now-a-days people prefer a drug which has no side effects. For that, the plant Argemone mexicana is a boon to the human being as it has a number of miraculous compounds to cure a various types of diseases. Single plant has a lot of uncountable benefits in drug discovery and which gives a base for new drug discovery. This plant is a weed, easily available and it does not require any special care which forms the base to develop a drug in socio economic form so that it could be made available to all people. This chapter provides an insight into various interesting pharmacological properties viz., Antidiabetic activity , Anti-Cancer activity, Anti-HIV activity, CNS related activities, Wound recovering action, Anti microbial activity, Antioxidant activity, Anti-inflammatory, analgesic, antipyretic activity, Hepatoprotective activity, Anti-fertility activity, Antiallergic activity, Nematicidal activity, Allelopathic effect, Antihelmintic activity, Larvicidal activity, Antifeedant action etc., which has been reviewed from different literatures in scientific journals. This present review would kindle many of the young minds to turn towards the nature i.e., plant based novel drug discovery with in-depth and extensive

  20. Leishmania mexicana infection of the eyelid in a traveler to Belize.

    PubMed

    Vinetz, Joseph M; Soong, Lynn

    2007-02-01

    A 50 year-old man, a United States resident, presented in Texas with a violaceous non-ulcerating lesion, involving the entire lower eyelid. The patient had traveled to a jungle area of Belize several hours drive from the capital city. Leishmania mexicana was isolated. The lesion only partially resolved after an initial course of sodium stibogluconate, requiring retreatment. At two years of follow-up, there was no relapse. The parasite isolated from the patient caused a progressive, non-ulcerating lesion in an experimental mouse footpad infection. This is an unusual case of cutaneous leishmaniasis in a traveler. Travelers must be educated about personal protective measures to prevent exotic infections acquired during travel.

  1. Leishmania mexicana infection of the eyelid in a traveler to Belize.

    PubMed

    Vinetz, Joseph M; Soong, Lynn

    2006-08-01

    A 50 year-old man, a United States resident, presented in Texas with a violaceous non-ulcerating lesion, involving the entire lower eyelid. The patient had traveled to a jungle area of Belize several hours drive from the capital city. Leishmania mexicana was isolated. The lesion only partially resolved after an initial course of sodium stibogluconate, requiring retreatment. At two years of follow-up, there was no relapse. The parasite isolated from the patient caused a progressive, non-ulcerating lesion in an experimental mouse footpad infection. This is an unusual case of cutaneous leishmaniasis in a traveler. Travelers must be educated about personal protective measures to prevent exotic infections acquired during travel.

  2. Tourism values for Mexican free-tailed bat (Tadarida brasiliensis mexicana) viewing

    USGS Publications Warehouse

    Bagstad, Kenneth J.; Widerholdt, Ruscena

    2013-01-01

    Migratory species provide diverse ecosystem services to people, but these values have seldom been estimated rangewide for a single species. In this article, we summarize visitation and consumer surplus for recreational visitors to viewing sites for the Mexican free-tailed bat (Tadarida brasiliensis mexicana) throughout the Southwestern United States. Public bat viewing opportunities are available at 17 of 25 major roosts across six states; on an annual basis, we estimate that over 242,000 visitors view bats, gaining over $6.5 million in consumer surplus. A better understanding of spatial mismatches between the areas where bats provide value to people and areas most critical for maintaining migratory populations can better inform conservation planning, including economic incentive systems for conservation.

  3. Peltomexicanin, a Peltogynoid Quinone Methide from Peltogyne Mexicana Martínez Purple Heartwood.

    PubMed

    Gutiérrez-Macías, Paulina; Peralta-Cruz, Javier; Borja-de-la-Rosa, Amparo; Barragán-Huerta, Blanca E

    2016-02-04

    Peltomexicanin (7,10-dihydroxy-6,12-dioxa-5H-tetraphen-3-one) is a new peltogynoid quinone methide isolated from Palo Morado (Peltogyne mexicana Martínez) heartwood by column chromatography. Its chemical structure was elucidated by IR, NMR (¹H, (13)C), 2D NMR experiments (COSY, NOESY, HMQC, and HSQC), ESI-MS, and UV-Vis spectroscopic analysis. According to HPLC quantification, this compound is the main pigment and accounts for 1.21% of Palo Morado heartwood material. The antioxidant activity of peltomexicanin and dried methanolic extract (DEx) of purple heartwood was evaluated using the radical of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assay, and the corresponding values expressed as Trolox equivalents (µmol TE/mg sample) were 4.25 and 4.57, respectively.

  4. Diversity among Tacaribe serocomplex viruses (family Arenaviridae) naturally associated with the Mexican woodrat (Neotoma mexicana)

    PubMed Central

    Cajimat, Maria N. B.; Milazzo, Mary Louise; Borchert, Jeff N.; Abbott, Ken D.; Bradley, Robert D.; Fulhorst, Charles F.

    2008-01-01

    The results of analyses of glycoprotein precursor and nucleocapsid protein gene sequences indicated that an arenavirus isolated from a Mexican woodrat (Neotoma mexicana) captured in Arizona is a strain of a novel species (proposed name Skinner Tank virus) and that arenaviruses isolated from Mexican woodrats captured in Colorado, New Mexico, and Utah are strains of Whitewater Arroyo virus or species phylogenetically closely related to Whitewater Arroyo virus. Pairwise comparisons of glycoprotein precursor sequences and nucleocapsid protein sequences revealed a high level of divergence among the viruses isolated from the Mexican woodrats captured in Colorado, New Mexico, and Utah and the Whitewater Arroyo virus prototype strain AV 9310135, which originally was isolated from a white-throated woodrat (Neotoma albigula) captured in New Mexico. Conceptually, the viruses from Colorado, New Mexico, and Utah and strain AV 9310135 could be grouped together in a species complex in the family Arenaviridae, genus Arenavirus. PMID:18304671

  5. Neuroprotective effects of Tilia americana var. mexicana on damage induced by cerebral ischaemia in mice.

    PubMed

    Angeles-López, Guadalupe E; González-Trujano, Ma Eva; Gómez, Claudia; Chánez-Cárdenas, Ma Elena; Ventura-Martinez, Rosa

    2016-09-01

    Tilia americana var. mexicana (T. americana) is a plant widely used in Mexico for its medicinal properties on the central nervous system. In the present study, we designed a protocol to investigate the neuroprotective effects of non-polar and polar extracts of T. americana on damage induced by cerebral ischaemia in mice. Vehicle or extracts were administered immediately after ischaemia. Functional neurological deficit, survival percentage and infarct area were determined in each experimental group. Results showed that groups treated with non-polar or polar extracts of T. americana had increased survival rate, improved neurological deficits and diminished the infarct area in relation to the ischaemic group. In conclusion, this study confirms the neuroprotective activity of T. americana, suggests a possible synergism between non-polar and polar constituents and supports its potential as a useful aid in the clinical management of stroke.

  6. Pharmacological evaluation of the anxiolytic and sedative effects of Tilia americana L. var. mexicana in mice.

    PubMed

    Aguirre-Hernández, E; Martínez, A L; González-Trujano, M E; Moreno, J; Vibrans, H; Soto-Hernández, M

    2007-01-03

    The anxiolytic and sedative effects of Tilia americana L. var. mexicana (Schltdl.) Hardin inflorescence extracts and its acute toxicity were tested. Sodium pentobarbital (SP)-induced hypnosis potentiation (SPP), as well as ambulatory activity and anti-anxiety response in three different experimental models were evaluated with hexane and methanol extracts in mice. In order to determine the proper timing of assessments and to identify the most active extract, a 100mg/kg dosage of hexane, ethyl acetate and methanol crude extracts were tested on SPP after 15, 30 and 60min of the administration. Then a dose-response curve was made for the hexane (10-1000mg/kg) and methanol (10-300mg/kg) extracts in all experimental models. Both extracts produced a significant and dose-dependent lengthening in the time of SP, with the methanol extract being more potent than the hexane extract at 60min after administration. Moreover, a significant and dose-dependent attenuation in the anxiety-response in the plus-maze test and exploratory cylinder activity, but also a diminution in the ambulatory activity and in the head dipping response were observed resembling the response to diazepam. Acute toxicity was observed with less dose of methanol extract (LD(50)=375mg/kg) in comparison to the hexane extract (LD(50)>2900mg/kg). Results of the present study shows that Tilia americana var. mexicana possesses depressant activity on the CNS similar to the better-studied species of European Tilia and reinforces its use as anxiolytic and sedative in traditional medicine.

  7. FcγRIII Mediates Immunoglobulin G-Induced Interleukin-10 and Is Required for Chronic Leishmania mexicana Lesions▿

    PubMed Central

    Thomas, Bolaji N.; Buxbaum, Laurence U.

    2008-01-01

    FcRγ and interleukin-10 (IL-10) are both required for chronic disease in C57BL/6 mice with Leishmania mexicana parasite infection. FcRγ is a component of several different FcRs and may be a component of some T-cell receptors. The initial antibody response to L. mexicana is an immunoglobulin G1 (IgG1) response, and IgG1 preferentially binds to FcγRIII in other systems. To begin to dissect the mechanisms by which FcγRs contribute to chronic disease, we infected FcγRIII knockout (KO) mice with L. mexicana. We show that FcγRIII KO mice are resistant to L. mexicana infection, resolving lesions in association with a stronger gamma interferon response, similar to IL-10 KO mice, with parasite control by 12 weeks. We found that the Leishmania-specific IgG response is unaltered in FcγRIII KO mice compared with that in wild-type controls. The frequencies of IL-10 production from lymph node CD25+ CD4+ T cells are the same in KO and wild-type mice, and depletion of CD25+ cells did not alter the course of infection, implying that Treg cells may not be the mechanism for susceptibility to L. mexicana infection, unlike for L. major infection. However, IL-10 mRNA was greatly diminished in the lesions of FcγRIII KO mice compared to that of B6 controls. Furthermore, macrophages from FcγRIII KO and FcRγ KO mice have the same profound defect in IL-10 production induced by IgG-opsonized amastigotes. We also found IL-10-dependent (major) and -independent (minor) inhibition of IL-12 mediated by FcγRIII, as well as parasite-mediated inhibition of IL-12 and induction of IL-10, independent of FcγR. Our data demonstrate a specific role for FcγRIII in suppressing protective immunity in L. mexicana infection, likely through macrophage IL-10 production in the lesion. PMID:18070890

  8. Destruction of leishmania mexicana amazonensis amastigotes within macrophages in culture by phenazine methosulfate and other electron carriers

    PubMed Central

    Rabinovitch, M; Dedet, J-P; Ryter, A; Robineaux, R; Topper, G; Brunet, E

    1982-01-01

    Exposure of macrophages infected with Leishmania mexicana amazonensis to phenazine methosulfate (PMS) resulted in rapid damage and disappearance of the intracellular amastigotes without obvious ill effects to the host cells. The reduction of the percent infection was related to the concentration of PMS and to the duration of the pulse. Most Leishmania disappeared within 2 h of a 2-h pulse with 10 μM of the drug. In contrast, pretreatment of the macrophages with PMS followed by removal of the drug before infection did not result in disappearance of the parasites. The pH of the PMS medium markedly influenced the disappearance of Leishmania: maximum effect was observed at pH 8.0, while the effect was negligible at pH 6.3. The pH effect may be related to pseudobase formation by the PMS cation. Dose-response curves for PMS were similar for resident, elicited, or activated macrophages. Observations by time-lapse cinemicrography documented the explosion-like fragmentation of the amastigotes within 1-2 h of exposure of infected macrophages to the drug. Parasite-derived granules and vacuoles were seen to scatter within the parasitophorous vacuoles. This early damage to the parasites was confirmed by transmission electron microscopic observations. Infected macrophages incubated with PMS displayed detectable vacuolar fluorescence, indicating that PMS or a metabolite of PMS had access to the vacuoles. A series of other electron carriers, including phenyl methanes, phenazines, oxazines, a xanthene, and a naphthoquinone, given continuously for 18 h, also induced the disappearance of the Leishmania. The most potent was crystal violet, active at 70 nM. The presence of apolar substituents enhanced activity and this is probably related to increased permeation of the dyes. Finally, PMS, as well as other electron carriers examined, also reduced the growth of Leishmania promastigotes in culture. The results are compatible with a direct effect of the drugs on the intracellular

  9. Development of newly sanguinarine biosynthetic capacity in in vitro rootless shoots of Argemone mexicana L. Mexican prickly poppy.

    PubMed

    Xool-Tamayo, Jorge; Serrano-Gamboa, Germán; Monforte-González, Miriam; Mirón-López, Gumersindo; Vázquez-Flota, Felipe

    2017-02-01

    To analyze berberine and sanguinarine biosynthetic capacities of both in vitro shoot and root cultures of Argemone mexicana and tissues from entire plants at different developmental stages. Berberine and sanguinarine were equally distributed in roots and aerial tissues of developing plantlet whereas, in juvenile plants, sanguinarine was only detected in roots. This alkaloid distribution was consistent with that of biosynthetic transcripts in juvenile plants. However, lower transcript abundance in plantlets´ leaves suggests that alkaloids were mainly formed in roots and then mobilized to this tissue. In vitro root cultures maintained similar alkaloid profiles to those from intact seedlings and plantlets. However, in addition to berberine, rootless shoot cultures accumulated high levels of sanguinarine and biosynthetic transcripts. In vitro shoot cultures of A. mexicana can synthesize sanguinarine in addition to berberine. This represent a convenient system for the production of both alkaloids.

  10. Two complete mitochondrial genomes from Praticolella mexicana Perez, 2011 (Polygyridae) and gene order evolution in Helicoidea (Mollusca, Gastropoda)

    PubMed Central

    Minton, Russell L.; Cruz, Marco A. Martinez; Farman, Mark L.; Perez, Kathryn E.

    2016-01-01

    Abstract Helicoidea is a diverse group of land snails with a global distribution. While much is known regarding the relationships of helicoid taxa, comparatively little is known about the evolution of the mitochondrial genome in the superfamily. We sequenced two complete mitochondrial genomes from Praticolella mexicana Perez, 2011 representing the first such data from the helicoid family Polygyridae, and used them in an evolutionary analysis of mitogenomic gene order. We found the mitochondrial genome of Praticolella mexicana to be 14,008 bp in size, possessing the typical 37 metazoan genes. Multiple alternate stop codons are used, as are incomplete stop codons. Mitogenome size and nucleotide content is consistent with other helicoid species. Our analysis of gene order suggested that Helicoidea has undergone four mitochondrial rearrangements in the past. Two rearrangements were limited to tRNA genes only, and two involved protein coding genes. PMID:27833437

  11. Vasorelaxant mode of action of dichloromethane-soluble extract from Agastache mexicana and its main bioactive compounds.

    PubMed

    Flores-Flores, Angélica; Hernández-Abreu, Oswaldo; Rios, María Yolanda; León-Rivera, Ismael; Aguilar-Guadarrama, Berenice; Castillo-España, Patricia; Perea-Arango, Irene; Estrada-Soto, Samuel

    2016-12-01

    Agastache mexicana (Kunth) Lint & Epling (Lamiaceae) is a plant used in Mexican traditional medicine for the treatment of hypertension, anxiety and so on. To determine the vasorelaxant effect and functional mode of action of dichloromethane-soluble extract from A. mexicana (DEAm) and isolate the constituents responsible for the pharmacological activity. Extracts were prepared from the aerial parts of A. mexicana (225.6 g) by successive maceration with hexane, dichloromethane and methanol (three times for 72 h at room temperature), respectively. DEAm (0.01-1000 μg/mL), fractions (at 174.27 μg/mL), acacetin and ursolic acid (UA) (0.5-500 μM) were evaluated to determine their vasorelaxant effect on ex vivo rat aorta ring model. In vivo UA antihypertensive action was determined on spontaneously hypertensive rats. DEAm induced a significant vasorelaxant effect in concentration-dependent and endothelium-independent manners (EC50 = 174.276 ± 5.98 μg/mL) by a calcium channel blockade and potassium channel opening. Bio-guided fractionation allowed to isolate acacetin (112 mg), UA (2.830 g), acacetin/oleanolic acid (OA) (M1) (155 mg) and acacetin/OA/UA (M2) (1.382 g) mixtures, which also showed significant vasodilation. UA significantly diminished diastolic (80 mmHg) and systolic blood pressure (120 mmHg), but heart rate was not modified. DEAm produced significant vasorelaxant action by myogenic control cation. The presence of acacetin, OA and UA into the extract was substantial for the relaxant activity of DEAm. In vivo antihypertensive action of UA corroborates the use of A. mexicana as an antihypertensive agent on Mexican folk medicine.

  12. Limited genetic diversity in the critically endangered Mexican howler monkey (Alouatta palliata mexicana) in the Selva Zoque, Mexico.

    PubMed

    Dunn, Jacob C; Shedden-González, Aralisa; Cristóbal-Azkarate, Jurgi; Cortés-Ortiz, Liliana; Rodríguez-Luna, Ernesto; Knapp, Leslie A

    2014-04-01

    The Mexican howler monkey (Alouatta palliata mexicana) is a critically endangered primate, which is paleoendemic to Mexico. However, despite the potential significance of genetic data for its management and conservation, there have been no population genetic studies of this subspecies. To examine genetic diversity in the key remaining forest refuge for A. p. mexicana, the Selva Zoque, we amplified full-length mitochondrial control region sequences (1,100 bp) from 45 individuals and found 7 very similar haplotypes. Haplotype diversity (h = 0.486) and nucleotide diversity (π = 0.0007) were extremely low compared to other Neotropical primates. Neutrality tests, used to evaluate demographic effects (Tajima's D = -1.48, p = 0.05; Fu's F s = -3.33, p = 0.02), and mismatch distribution (sum of squares deviation = 0.006, p = 0.38; raggedness index = 0.12, p = 0.33) were consistent with a recent and mild population expansion and genetic diversity appears to be historically low in this taxon. Future studies should use a combination of mitochondrial and nuclear markers to fully evaluate genetic diversity and to better understand demographic history in A. p. mexicana. These studies should be undertaken throughout its geographic range in order to evaluate population structure and identify management units for conservation. Due to the limited distribution and population size of A. p. mexicana, future conservation strategies may need to consider genetic management. However, a more detailed knowledge of the population genetics of the subspecies is urgently recommended to maximise the conservation impact of these strategies.

  13. Genetic diversity, mating system, and conservation of a Mexican subalpine relict, Picea mexicana Martínez

    Treesearch

    F. Thomas Ledig; Paul D. Hodgskiss; Virginia Jacob-Cervantes

    2002-01-01

    Mexican spruce (Picea mexicana Martínez), an endangered species of the highest sky islands in México’s Sierra Madre Oriental and Sierra Madre Occidental, is threatened by fire, grazing, and global warming. Its conservation depends on whether it also is threatened by inbreeding and loss of genic diversity. We used 18 isozyme markers in 12 enzyme...

  14. Antidepressant-like and toxicological effects of a standardized aqueous extract of Chrysactinia mexicana A. Gray (Asteraceae) in mice.

    PubMed

    Cassani, Julia; Ferreyra-Cruz, Octavio Alberto; Dorantes-Barrón, Ana María; Villaseñor, Rosa María Vigueras; Arrieta-Baez, Daniel; Estrada-Reyes, Rosa

    2015-08-02

    C. mexicana A. Gray (Asteraceae) is a native of North America plant. In Mexico׳s folk medicine it is used for the fever, rheumatism and as a diuretic, antispasmodic, general tonic or adaptogenic herb, and as a stimulant agent. The aim of the study was to examine the antidepressant-like properties of an aqueous extract of C. mexicana (Cm), in order to scientifically describe its potential value in the management of depressive disorders. To evaluate the acute and subacute toxic effects of Cm and effects on hepatic and biochemical functions in mice. Antidepressant-like effects of Cm were evaluated in the Forced swimming and suspension tail tests (FST and TST), the ambulatory activity was measure in the Open Field Test (OFT), motor coordination was evaluated in the inverted screen and gyratory roller (IST and Rota-rod), the biochemical and histopathological analysis were carried out. Phytochemical studies of organic and aqueous extracts of Cm were thoroughly conducted. Cm produced a significant reduction of the immobility time both FST and in TST, without affect the ambulatory activity of experimental mice. Cm did not produce any damage in the hepatic functions, nor produce any significant change in the morphological tissue of organs examined. Chrysactinia mexicana induces a clear antidepressant-like effect in mice, without affect any basic functions. The consumption of this medicinal plant does not represent risk for health. The chemical analysis showed the flavonoids free and glycosides mainly. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  15. Bolete diversity in two relict forests of the Mexican beech (Fagus grandifolia var. mexicana; Fagaceae).

    PubMed

    Rodríguez-Ramírez, Ernesto Ch; Moreno, Claudia E

    2010-05-01

    The current distribution of the endangered Mexican beech [Fagus grandifolia var. mexicana (Martinez) Little] is restricted to relict isolated populations in small remnants of montane cloud forest in northeastern Mexico, and little is known about its associated biota. We sampled bolete diversity in two of these monospecific forests in the state of Hidalgo, Mexico. We compared alpha diversity, including species richness and ensemble structure, and analyzed beta diversity (dissimilarity in species composition) between forests. We found 26 bolete species, five of which are probably new. Species diversity and evenness were similar between forests. Beta diversity was low, and the similarities of bolete samples from within and between forests were not significantly different. These results support the idea that the two forests share a single bolete ensemble with a common history. In contrast, cumulative species richness differed between the forests, implying that factors other than the mere presence of the host species have contributed to shaping the biodiversity of ectomycorrhizal fungi in relict Mexican beech forests.

  16. Genetic variation and migration in the Mexican free-tailed bat (Tadarida brasiliensis mexicana).

    PubMed

    Russell, A L; Medellín, R A; McCracken, G F

    2005-06-01

    Incomplete lineage sorting can genetically link populations long after they have diverged, and will exert a more powerful influence on larger populations. The effects of this stochastic process can easily be confounded with those of gene flow, potentially leading to inaccurate estimates of dispersal capabilities or erroneous designation of evolutionarily significant units (ESUs). We have used phylogenetic, population genetic, and coalescent methods to examine genetic structuring in large populations of a widely dispersing bat species and to test hypotheses concerning the influences of coalescent stochasticity vs. gene flow. The Mexican free-tailed bat, Tadarida brasiliensis mexicana, exhibits variation in both migratory tendency and route over its range. Observations of the species' migratory behaviour have led to the description of behaviourally and geographically defined migratory groups, with the prediction that these groups compose structured gene pools. Here, we used mtDNA sequence analyses coupled with existing information from allozyme, banding, and natural history studies to evaluate hypotheses regarding the relationship between migration and genetic structure. Analyses of molecular variance revealed no significant genetic structuring of behaviourally distinct migratory groups. Demographic analyses were consistent with population growth, although the timing of population expansion events differs between migratory and nonmigratory populations. Hypotheses concerning the role of gene flow vs. incomplete lineage sorting on these data are explored using coalescent simulations. Our study demonstrates the importance of accounting for coalescent stochasticity in formulating phylogeographical hypotheses, and indicates that analyses that do not take such processes into account can lead to false conclusions regarding a species' phylogeographical history.

  17. Microhabitat use, population densities, and size distributions of sulfur cave-dwelling Poecilia mexicana

    PubMed Central

    Bierbach, David; Riesch, Rüdiger; Schießl, Angela; Wigh, Adriana; Arias-Rodriguez, Lenin; Indy, Jeane Rimber; Klaus, Sebastian; Zimmer, Claudia; Plath, Martin

    2014-01-01

    The Cueva del Azufre in Tabasco, Mexico, is a nutrient-rich cave and its inhabitants need to cope with high levels of dissolved hydrogen sulfide and extreme hypoxia. One of the successful colonizers of this cave is the poeciliid fish Poecilia mexicana, which has received considerable attention as a model organism to examine evolutionary adaptations to extreme environmental conditions. Nonetheless, basic ecological data on the endemic cave molly population are still missing; here we aim to provide data on population densities, size class compositions and use of different microhabitats. We found high overall densities in the cave and highest densities at the middle part of the cave with more than 200 individuals per square meter. These sites have lower H2S concentrations compared to the inner parts where most large sulfide sources are located, but they are annually exposed to a religious harvesting ceremony of local Zoque people called La Pesca. We found a marked shift in size/age compositions towards an overabundance of smaller, juvenile fish at those sites. We discuss these findings in relation to several environmental gradients within the cave (i.e., differences in toxicity and lighting conditions), but we also tentatively argue that the annual fish harvest during a religious ceremony (La Pesca) locally diminishes competition (and possibly, cannibalism by large adults), which is followed by a phase of overcompensation of fish densities. PMID:25083351

  18. The toxicity of Mexican poppy (Argemone mexicana L) seeds to rats.

    PubMed

    Pahwa, R; Chatterjee, V C

    1989-12-01

    Toxicolethal effects of seeds of mexican poppy (Argemone mexicana L) were investigated in to roof rat, (Rattus rattus L). The argemone seeds were fed at 100% of the diet up to the death or for a maximum of 10 days. Observed signs of poisoning were sedation, passiveness, sluggishness, feeble or no muscular jerks, abdominal contractions and increased defecation. Also black secretions from the eyes, corneal opacity, erection of hairs, and edema of the hind legs and submandibular space in were noted. Fourteen of 16 rats died. Significant reduction in the weights of the rats was observed. There were significant increases in blood glucose, BUN and SGOT. Major histopathological lesions were: hepatocytolysis, nuclear degeneration, pyknosis, cloudy swelling and dilatated sinusoids disturbing the lobulalar architecture of the liver; proliferated endothelium of glomeruli, hemorrhage in glomeruli and interstitium, and cloudy swelling of convoluted tubular epithelium in the kidney cortical region; erosion and atrophy of the upper stomach mucosa and calcification in the cardiac stomach, and; erosion and congestion of the upper mucosa of the duodenum. No change was noticed in the ileum.

  19. Pterygodermatites (Pterygodermatites) mexicana n. sp. (Nematoda: Rictulariidae), a parasite of Balantiopteryx plicata (Chiroptera) in Mexico

    PubMed Central

    2013-01-01

    A new species of nematode, Pterygodermatites (Pterygodermatites) mexicana n. sp., is described based on specimens recovered from the intestine of the gray sac-winged bat, Balantiopteryx plicata (Chiroptera, Emballonuridae), from the Biosphere Reserve “Sierra de Huautla” in the state of Morelos, Mexico. This is the second species in the genus described from bats in the New World, since most of the rictaluriids reported in these hosts belong to the closely related genus Rictularia Froelich, 1802. However, members of Rictularia possess only a single oesophageal tooth at the base of the buccal capsule, whereas in the current nematodes three conspicuous oesophageal teeth are present. They are therefore included in Pterygodermatites Wedl, 1861. The new species is characterized by the presence of 23 small denticles on the periphery of the buccal capsule and by the presence of 40 and 66 pairs of cuticular processes in males and females, respectively. Additionally, males possess 3–4 ventral precloacal fan-like processes, and the cuticular processes of females are divided into 40 pairs of comb-like and 26 pairs of spine-like processes; the vulva opens on the level of approximately pair 40. The dorsally directed stoma and the 40 prevulvar cuticular processes makes it difficult to place the species in any of the subgenera present in the New World, yet characters correspond with the diagnosis of Pterygodermatites (Pterygodermatites) in the Mediterranean region and North Africa. PMID:24267823

  20. Investigation of adsorption of Rhodamine B onto a natural adsorbent Argemone mexicana.

    PubMed

    Khamparia, Shraddha; Jaspal, Dipika

    2016-12-01

    The present study aims at exploring the potential of the seeds of a tropical weed, Argemone mexicana (AM), for the removal of a toxic xanthene textile dye, Rhodamine B (RHB), from waste water. Impact of pH, adsorbent dosage, particle size, contact time and dye concentration have been assessed during adsorption. The weed has been well characterized by several latest techniques thereby providing an indepth information of the mechanism during adsorption. About 80% removal has been attained with 0.06 g of adsorbent over the studied system. Thermodynamic and kinetic studies, followed by second order kinetic model, directed towards the endothermic nature of adsorption. The results obtained from batch experiments were modelled using Langmuir and Freundlich isotherm and were analysed on the basis of R(2) and six error functions for selection of appropriate model. Langmuir isotherm was found to be best fitted to the experimental data with high values of R(2) and lower values of error functions. Adsorption study revealed the affinity of AM seeds for the dye ions present in waste water, introducing a novel adsorbent in field of waste water treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Sporothrix brasiliensis, S. globosa, and S. mexicana, Three New Sporothrix Species of Clinical Interest▿

    PubMed Central

    Marimon, Rita; Cano, Josep; Gené, Josepa; Sutton, Deanna A.; Kawasaki, Masako; Guarro, Josep

    2007-01-01

    Sporothrix schenckii is the species responsible for sporotrichosis, a fungal infection caused by the traumatic implantation of this dimorphic fungus. Recent molecular studies have demonstrated that this species constitutes a complex of numerous phylogenetic species. Since the delineation of such species could be of extreme importance from a clinical point of view, we have studied a total of 127 isolates, most of which were received as S. schenckii, including the available type strains of species currently considered synonyms, and also some close morphological species. We have phenotypically characterized all these isolates using different culture media, growth rates at different temperatures, and numerous nutritional tests and compared their calmodulin gene sequences. The molecular analysis revealed that Sporothrix albicans, S. inflata, and S. schenckii var. luriei are species that are clearly different from S. schenckii. The combination of these phenetic and genetic approaches allowed us to propose the new species Sporothrix brasiliensis, S. globosa, and S. mexicana. The key phenotypic features for recognizing these species are the morphology of the sessile pigmented conidia, growth at 30, 35, and 37°C, and the assimilation of sucrose, raffinose, and ribitol. PMID:17687013

  2. La Familia: methodological issues in the assessment of perinatal social support for Mexicanas living in the United States.

    PubMed

    Clark, L

    2001-11-01

    Do Mexicanas receive social support from a close network of family and friends during the perinatal period? To answer this question, a longitudinal ethnographic study followed 28 urban Mexican-origin women living in the US from their last trimester of pregnancy through their first month post-partum. A total of 93 interviews with Mexicanas focused on health and social support. All of the women lived in a large western city in the US but varied in their acculturation and income levels. Analyses identified four social support themes from women's experience (the emic analysis) and four social support typologies from the researcher (etic) analyses. The kinds of support women described as emanating from their support networks were inductively identified as Helping with Daily Hassles, Showing Love and Understanding, Being There for Me, and My Family Failing Me. Approximately half of the women reported densely supportive networks. The other women were disconnected from their support networks, or dealt with antagonism or instability in their networks. Women's perceptions of social support differed from the judgements made by the researcher about received support. Specifically, women perceived more network members in the supportive category than did the researcher by a factor of 1.4, and fewer network members in the disconnected category by a factor of 0.7. From an emic perspective, women listed only half as many antagonistic network members compared to the etic analysis (a factor of 0.50). These emic/etic discrepancies complicate clinical assessment of social support, but suggest that data on social support should be collected as part of the clinical processes of perinatal risking. To enhance assessment of social support, a clinically relevant guide is proposed for use by practitioners caring for Mexicanas in the perinatal period.

  3. Complexities of gene expression patterns in natural populations of an extremophile fish (Poecilia mexicana, Poeciliidae).

    PubMed

    Passow, Courtney N; Brown, Anthony P; Arias-Rodriguez, Lenin; Yee, Muh-Ching; Sockell, Alexandra; Schartl, Manfred; Warren, Wesley C; Bustamante, Carlos; Kelley, Joanna L; Tobler, Michael

    2017-08-01

    Variation in gene expression can provide insights into organismal responses to environmental stress and physiological mechanisms mediating adaptation to habitats with contrasting environmental conditions. We performed an RNA-sequencing experiment to quantify gene expression patterns in fish adapted to habitats with different combinations of environmental stressors, including the presence of toxic hydrogen sulphide (H2 S) and the absence of light in caves. We specifically asked how gene expression varies among populations living in different habitats, whether population differences were consistent among organs, and whether there is evidence for shared expression responses in populations exposed to the same stressors. We analysed organ-specific transcriptome-wide data from four ecotypes of Poecilia mexicana (nonsulphidic surface, sulphidic surface, nonsulphidic cave and sulphidic cave). The majority of variation in gene expression was correlated with organ type, and the presence of specific environmental stressors elicited unique expression differences among organs. Shared patterns of gene expression between populations exposed to the same environmental stressors increased with levels of organismal organization (from transcript to gene to physiological pathway). In addition, shared patterns of gene expression were more common between populations from sulphidic than populations from cave habitats, potentially indicating that physiochemical stressors with clear biochemical consequences can constrain the diversity of adaptive solutions that mitigate their adverse effects. Overall, our analyses provided insights into transcriptional variation in a unique system, in which adaptation to H2 S and darkness coincide. Functional annotations of differentially expressed genes provide a springboard for investigating physiological mechanisms putatively underlying adaptation to extreme environments. © 2017 John Wiley & Sons Ltd.

  4. Variation in ectomycorrhizal fungal communities associated with Oreomunnea mexicana (Juglandaceae) in a Neotropical montane forest.

    PubMed

    Corrales, Adriana; Arnold, A Elizabeth; Ferrer, Astrid; Turner, Benjamin L; Dalling, James W

    2016-01-01

    Neotropical montane forests are often dominated by ectomycorrhizal (EM) tree species, yet the diversity of their EM fungal communities remains poorly explored. In lower montane forests in western Panama, the EM tree species Oreomunnea mexicana (Juglandaceae) forms locally dense populations in forest otherwise characterized by trees that form arbuscular mycorrhizal (AM) associations. The objective of this study was to compare the composition of EM fungal communities associated with Oreomunnea adults, saplings, and seedlings across sites differing in soil fertility and the amount and seasonality of rainfall. Analysis of fungal nrITS DNA (nuclear ribosomal internal transcribed spacers) revealed 115 EM fungi taxa from 234 EM root tips collected from adults, saplings, and seedlings in four sites. EM fungal communities were equally species-rich and diverse across Oreomunnea developmental stages and sites, regardless of soil conditions or rainfall patterns. However, ordination analysis revealed high compositional turnover between low and high fertility/rainfall sites located ca. 6 km apart. The EM fungal community was dominated by Russula (ca. 36 taxa). Cortinarius, represented by 14 species and previously reported to extract nitrogen from organic sources under low nitrogen availability, was found only in low fertility/high rainfall sites. Phylogenetic diversity analyses of Russula revealed greater evolutionary distance among taxa found on sites with contrasting fertility and rainfall than was expected by chance, suggesting that environmental differences among sites may be important in structuring EM fungal communities. More research is needed to evaluate whether EM fungal taxa associated with Oreomunnea form mycorrhizal networks that might account for local dominance of this tree species in otherwise diverse forest communities.

  5. 17β-ESTRADIOL INCREASES LEISHMANIA MEXICANA KILLING IN MACROPHAGES FROM DBA/2 MICE BY ENHANCING PRODUCTION OF NITRIC OXIDE BUT NOT PRO-INFLAMMATORY CYTOKINES

    PubMed Central

    LEZAMA-DÁVILA, C.M.; ISAAC-MÁRQUEZ, A.P.; BARBI, J.; OGHUMU, S.; SATOSKAR, A.R.

    2014-01-01

    We have previously shown that female DBA/2 mice are significantly more resistant to Leishmania mexicana compared with males. Here, we have analyzed the effect of 17β-estradiol (E2) on function and cytokine production in male and female DBA/2 macrophages in vitro. We show that E2 increases NO production and parasite killing in L. mexicana-infected male and female DBA/2 macrophages without increasing production of pro-inflammatory cytokines. These data indicate that E2 may enhance leishmanicidal activity in macrophages by directly regulating production of NO. PMID:17556622

  6. A galactosyl(alpha 1-3)mannose epitope on phospholipids of Leishmania mexicana and L. braziliensis is recognized by trypanosomatid-infected human sera.

    PubMed Central

    Avila, J L; Rojas, M

    1990-01-01

    An immunoglobulin M antibody reactive with galactosyl(alpha 1-3)mannose [Gal(alpha 1-3)Man] residues present on phospholipids extracted from Leishmania mexicana and L. braziliensis was found to be present in high titer in the serum of every normal individual studied. Periodate oxidation, acid hydrolysis, or acetylation suppressed immunoreactivity, suggesting that an oligosaccharide chain was responsible for antibody binding. Interaction occurs only with alpha-Gal terminal residues, since treatment of purified glycophospholipids with alpha-galactosidase but not with beta-galactosidase abolished it. Antibody bound to galactosyl(alpha 1-3)galactose-linked synthetic antigens but did not bind to the same residues present in rabbit, rat, and guinea pig erythrocytes or in murine laminin. Antigen-antibody binding was strongly blocked with Gal(alpha 1-3)Man and Gal(beta 1-4)Man. These results plus inhibition studies with several oligosaccharides suggest that they are indeed different from antibodies against the galactosyl(alpha 1-3)galactose residue. Anti-Gal(alpha 1-3)Man antibody values were significantly elevated in 89% of patients with diffuse cutaneous leishmaniasis, 84% of patients with localized cutaneous leishmaniasis, 69% of patients with mucocutaneous leishmaniasis, and 44 and 62% of patients with Trypanosoma cruzi or T. rangeli infection, respectively, but not in patients with 15 other different infectious and inflammatory diseases. Anti-Gal(alpha 1-3)Man antibody readily absorbed to American Leishmania and Trypanosoma culture forms, suggesting a surface membrane localization of reactive epitope. Gal(alpha 1-3)Man-bearing glycophospholipid was easily extracted from American Leishmania promastigotes and T. cruzi trypomastigotes as well as from American Trypanosoma culture forms. The possibility that this antibody arises against parasitic glycophospholipid-linked Gal(alpha 1-3)Man terminal residues is proposed. PMID:1696285

  7. Outbreeding and lack of temporal genetic structure in a drone congregation of the neotropical stingless bee Scaptotrigona mexicana.

    PubMed

    Mueller, Matthias Y; Moritz, Robin Fa; Kraus, F Bernhard

    2012-06-01

    Drone aggregations are a widespread phenomenon in many stingless bee species (Meliponini), but the ultimate and proximate causes for their formation are still not well understood. One adaptive explanation for this phenomenon is the avoidance of inbreeding, which is especially detrimental for stingless bees due to the combined effects of the complementary sex-determining system and the small effective population size caused by eusociality and monandry. We analyzed the temporal genetic dynamics of a drone aggregation of the stingless bee Scaptotrigona mexicana with microsatellite markers over a time window of four weeks. We estimated the drones of the aggregation to originate from a total of 55 colonies using sibship re-construction. There was no detectable temporal genetic differentiation or sub-structuring in the aggregation. Most important, we could exclude all colonies in close proximity of the aggregation as origin of the drones in the aggregation, implicating that they originate from more distant colonies. We conclude that the diverse genetic composition and the distant origin of the drones of the S. mexicana drone congregation provides an effective mechanism to avoid mating among close relatives.

  8. Toxic hydrogen sulphide and dark caves: pronounced male life-history divergence among locally adapted Poecilia mexicana (Poeciliidae).

    PubMed

    Riesch, R; Plath, M; Schlupp, I

    2011-03-01

    Chronic environmental stress is known to induce evolutionary change. Here, we assessed male life-history trait divergence in the neotropical fish Poecilia mexicana from a system that has been described to undergo incipient ecological speciation in adjacent, but reproductively isolated toxic/nontoxic and surface/cave habitats. Examining both field-caught and common garden-reared specimens, we investigated the extent of differentiation and plasticity of life-history strategies employed by male P. mexicana. We found strong site-specific life-history divergence in traits such as fat content, standard length and gonadosomatic index. The majority of site-specific life-history differences were also expressed under common garden-rearing conditions. We propose that apparent conservatism of male life histories is the result of other (genetically based) changes in physiology and behaviour between populations. Together with the results from previous studies, this is strong evidence for local adaptation as a result of ecologically based divergent selection.

  9. Two Lactarius species associated with a relict Fagus grandifolia var. mexicana population in a Mexican montane cloud forest.

    PubMed

    Montoya, L; Haug, I; Bandala, V M

    2010-01-01

    Ectomycorrhizal (EM) fleshy fungi are being monitored in a population of Fagus grandifolia var. mexicana persisting in a montane cloud forest refuge on a volcano in a subtropical region of central Veracruz (eastern Mexico). The population of Fagus studied represents one of the 10 recognized forest fragments still housing this tree genus in Mexico. This is the first attempt to document EM fungi associated with this tree species in Mexico. We present evidence of the ectomycorrhizal symbiosis for Lactarius badiopallescens and L. cinereus with this endemic tree. Species identification of Lactarius on Fagus grandifolia var. mexicana was based on the comparison of DNAsequences (ITS rDNA) of spatiotemporally co-occurring basidiomes and EM root tips. The host of the EM tips was identified by comparison of the large subunit of the ribulose-bisphosphate carboxylase gene (rbcL). The occurrence of Lactarius badiopallescens and L. cinereus populations in the area of study represent the southernmost record known to date of these two species in North America and are new for the Neotropical Lactarius mycota. Descriptions coupled with illustrations of macro- and micromorphological features of basidiomes as well as photographs of ectomycorrhizas are presented.

  10. Outbreeding and lack of temporal genetic structure in a drone congregation of the neotropical stingless bee Scaptotrigona mexicana

    PubMed Central

    Mueller, Matthias Y; Moritz, Robin FA; Kraus, F Bernhard

    2012-01-01

    Drone aggregations are a widespread phenomenon in many stingless bee species (Meliponini), but the ultimate and proximate causes for their formation are still not well understood. One adaptive explanation for this phenomenon is the avoidance of inbreeding, which is especially detrimental for stingless bees due to the combined effects of the complementary sex-determining system and the small effective population size caused by eusociality and monandry. We analyzed the temporal genetic dynamics of a drone aggregation of the stingless bee Scaptotrigona mexicana with microsatellite markers over a time window of four weeks. We estimated the drones of the aggregation to originate from a total of 55 colonies using sibship re-construction. There was no detectable temporal genetic differentiation or sub-structuring in the aggregation. Most important, we could exclude all colonies in close proximity of the aggregation as origin of the drones in the aggregation, implicating that they originate from more distant colonies. We conclude that the diverse genetic composition and the distant origin of the drones of the S. mexicana drone congregation provides an effective mechanism to avoid mating among close relatives. PMID:22833802

  11. High precision during food recruitment of experienced (reactivated) foragers in the stingless bee Scaptotrigona mexicana (Apidae, Meliponini).

    PubMed

    Sánchez, Daniel; Nieh, James C; Hénaut, Yann; Cruz, Leopoldo; Vandame, Rémy

    2004-07-01

    Several studies have examined the existence of recruitment communication mechanisms in stingless bees. However, the spatial accuracy of location-specific recruitment has not been examined. Moreover, the location-specific recruitment of reactivated foragers, i.e., foragers that have previously experienced the same food source at a different location and time, has not been explicitly examined. However, such foragers may also play a significant role in colony foraging, particularly in small colonies. Here we report that reactivated Scaptotrigona mexicana foragers can recruit with high precision to a specific food location. The recruitment precision of reactivated foragers was evaluated by placing control feeders to the left and the right of the training feeder (direction-precision tests) and between the nest and the training feeder and beyond it (distance-precision tests). Reactivated foragers arrived at the correct location with high precision: 98.44% arrived at the training feeder in the direction trials (five-feeder fan-shaped array, accuracy of at least +/-6 degrees of azimuth at 50 m from the nest), and 88.62% arrived at the training feeder in the distance trials (five-feeder linear array, accuracy of at least +/-5 m or +/-10% at 50 m from the nest). Thus, S. mexicana reactivated foragers can find the indicated food source at a specific distance and direction with high precision, higher than that shown by honeybees, Apis mellifera, which do not communicate food location at such close distances to the nest.

  12. High precision during food recruitment of experienced (reactivated) foragers in the stingless bee Scaptotrigona mexicana (Apidae, Meliponini)

    NASA Astrophysics Data System (ADS)

    Sánchez, Daniel; Nieh, James C.; Hénaut, Yann; Cruz, Leopoldo; Vandame, Rémy

    Several studies have examined the existence of recruitment communication mechanisms in stingless bees. However, the spatial accuracy of location-specific recruitment has not been examined. Moreover, the location-specific recruitment of reactivated foragers, i.e., foragers that have previously experienced the same food source at a different location and time, has not been explicitly examined. However, such foragers may also play a significant role in colony foraging, particularly in small colonies. Here we report that reactivated Scaptotrigona mexicana foragers can recruit with high precision to a specific food location. The recruitment precision of reactivated foragers was evaluated by placing control feeders to the left and the right of the training feeder (direction-precision tests) and between the nest and the training feeder and beyond it (distance-precision tests). Reactivated foragers arrived at the correct location with high precision: 98.44% arrived at the training feeder in the direction trials (five-feeder fan-shaped array, accuracy of at least +/-6° of azimuth at 50 m from the nest), and 88.62% arrived at the training feeder in the distance trials (five-feeder linear array, accuracy of at least +/-5 m or +/-10% at 50 m from the nest). Thus, S. mexicana reactivated foragers can find the indicated food source at a specific distance and direction with high precision, higher than that shown by honeybees, Apis mellifera, which do not communicate food location at such close distances to the nest.

  13. A phylogeny of the Lampropeltis mexicana complex (Serpentes: Colubridae) based on mitochondrial DNA sequences suggests evidence for species-level polyphyly within Lampropeltis.

    PubMed

    Bryson, Robert W; Pastorini, Jennifer; Burbrink, Frank T; Forstner, Michael R J

    2007-05-01

    The systematic relationships of snakes in the Lampropeltis mexicana complex (L. mexicana, L. alterna, and L. ruthveni) are poorly known despite several taxonomic studies over the last 80 years. Mitochondrial DNA sequences were used to infer the phylogeny of the L. mexicana complex. At least one representative sample from the nine currently recognized species of Lampropeltis was sequenced. Our results suggest that a deep basal split resulted in the divergence of two groups of Lampropeltis, with one group occupying the upland areas of western United States and most of western and central Mexico, and the other northeastern Mexico and the lowland areas of the southern United States. Results also revealed that the L. mexicana complex and Lampropeltis triangulum are polyphyletic, with taxa from both groups nested together in deeply divergent northern and southern clades. These results are incongruent with previous hypotheses of phylogenetic relationships based on morphology, and suggest that morphological characters shared among the various tri-colored Lampropeltis (e.g., hemipenal structure and tri-colored pattern) may be difficult to interpret phylogenetically.

  14. [Determination of the specificity of seric IgA produced in response to antigens of Leishmania (Leishmania) mexicana in murine leishmaniasis].

    PubMed

    Pérez-Aguilar, Mary Carmen; Hernández, Oskarina; Maizo de Segnini, Zulay; Rojas, Carmen Haydee; Díaz, Silverio; Alarcón, Maritza; Goncalves, Loredana

    2011-09-01

    In experimental leishmaniasis, the role of antibodies is not entirely clear, as some authors consider that these proteins are not involved in protection against infection. However, histopathological studies in human and experimental leishmaniasis lesions, show plasma cell infiltrates positive for IgA and secretion of IgM, IgG and IgA could mediate the formation of immune complexes with parasite antigens or self components, favoring necrosis leading to the elimination of the parasite. In this study, we determined if the serum IgA in the murine model has specific reactivity against antigens of Leishmania (Leishmania) mexicana of diagnostic utility. To do this, we used mice either susceptible or resistant to cutaneous leishmaniasis, and demonstrated by indirect ELISA that serum IgA is elevated in susceptible mice compared with that produced by resistant mice. Although other studies in murine models show that the serum IgG from mice infected with L. (L) mexicana present cross reactivity with unrelated parasite antigens derived from Trypanosoma cruzi, the analysis of the specificity of IgA by antigens of L. (L) mexicana and T. cruzi, by Western Blot, showed that the IgA serum of mice infected with T. cruzi reacts too with antigens of L. (L) mexicana. These findings suggest that IgA may be useful for the clinical management and prognosis of the disease.

  15. DIABETES MELLITUS COMO FACTOR DE RIESGO DE DEMENCIA EN LA POBLACIÓN ADULTA MAYOR MEXICANA

    PubMed Central

    Silvia, Mejía-Arango; Clemente, y Zúñiga-Gil

    2012-01-01

    Introduccion La diabetes mellitus y las demencias constituyen dos problemas crecientes de salud entre la población adulta mayor del mundo y en particular de los paises en desarrollo. Hacen falta estudios longitudinales sobre el papel de la diabetes como factor de riesgo para demencia. Objetivo Determinar el riesgo de demencia en sujetos Mexicanos con diabetes mellitus tipo 2. Materiales y Metodos Los sujetos diabéticos libres de demencia pertenecientes al Estudio Nacional de Salud y Envejecimiento en México fueron evaluados a los dos años de la línea de base. Se estudió el papel de los factores sociodemográficos, de otras comorbilidades y del tipo de tratamiento en la conversión a demencia. Resultados Durante la línea de base 749 sujetos (13.8%) tuvieron diabetes. El riesgo de desarrollar demencia en estos individuos fue el doble (RR, 2.08 IC 95%, 1.59–2.73). Se encontró un riesgo mayor en individuos de 80 años y más (RR 2.44 IC 95%, 1.46–4.08), en los hombres (RR, 2.25 IC 95%, 1.46–3.49) y en sujetos con nivel educativo menor de 7 años. El estar bajo tratamiento con insulina incrementó el riesgo de demencia (RR, 2.83, IC 95%, 1.58–5.06). Las otras comorbilidades que aumentaron el riesgo de demencia en los pacientes diabéticos fueron la hipertensión (RR, 2.75, IC 95%, 1.86–4.06) y la depresión (RR, 3.78, 95% IC 2.37–6.04). Conclusión Los sujetos con diabetes mellitus tienen un riesgo mayor de desarrollar demencia, La baja escolaridad y otras comorbilidades altamente prevalentes en la población Mexicana contribuyen a la asociación diabetes-demencia. PMID:21948010

  16. The role of androgens in species recognition and sperm production in Atlantic mollies (Poecilia mexicana).

    PubMed

    Gabor, Caitlin R; Aspbury, Andrea S; Ma, Jacqueline; Nice, Chris C

    2012-02-01

    Much is known about the role of hormones in the regulation of vertebrate mating behavior, including receptivity, and several components of mate choice. Hormones may modulate reproductive behavior in such a way to increase or decrease the individual's motivation, and therefore hormones may be important in mediating behavior associated with reproductive isolation. The mating complex of the all female gynogenetic Amazon mollies, Poecilia formosa, and their parental species (sailfin mollies, P. latipinna, and Atlantic mollies, P. mexicana) is a model system for studying ultimate mechanisms of species recognition. However, proximate mechanisms, such as variation in hormone levels, and the effect of hormones on sperm production have not been extensively examined. We predict that one or more of the sex steroid hormones in teleost fish (11-ketotestosterone (KT), testosterone (T), and estradiol (E)) will play a role in species recognition (during mate choice and/or sperm priming) for Atlantic mollies (the maternal parental species) that are sympatric with Amazon mollies. We sequentially paired male Atlantic mollies with female conspecifics and Amazon mollies and obtained water-borne hormone samples before and after mating for all fish. We measured circulating KT, T, and E from the water samples. Although we did not find an overall KT response to mating with conspecifics as has been found previously in sailfin mollies, male Atlantic mollies that mated more with conspecific females had lower postmating T levels. Additionally, males attempted to mate more with conspecific females that had lower postmating E levels, but attempted to mate more with Amazon mollies that had higher postmating KT levels. We also examined the effect of KT on sperm priming (a mechanism of premating mate choice), and found that KT levels of male Atlantic mollies prior to mating are correlated with the sperm priming response when males were paired with conspecific females, but this correlation was not

  17. Diagnosis and treatment of gastroesophageal reflux disease: recommendations of the Asociación Mexicana de Gastroenterología.

    PubMed

    Huerta-Iga, F; Bielsa-Fernández, M V; Remes-Troche, J M; Valdovinos-Díaz, M A; Tamayo-de la Cuesta, J L

    Emerging concepts in the pathophysiology of gastroesophageal reflux disease (GERD) and the constant technologic advances in the diagnosis and treatment of this clinical condition make it necessary to frequently review and update the clinical guidelines, recommendations, and official statements from the leading academic groups worldwide. The Asociación Mexicana de Gastroenterología (AMG), aware of this responsibility, brought together national experts in this field to analyze the most recent scientific evidence and formulate a series of practical recommendations to guide and facilitate the diagnostic process and efficacious treatment of these patients. The document includes algorithms, figures, and tables for convenient consultation, along with opinions on GERD management in sensitive populations, such as pregnant women and older adults.

  18. Evidence for prenatal transfer of rabies virus in the Mexican free-tailed bat (Tadarida brasiliensis Mexicana).

    PubMed

    Steece, R S; Calisher, C H

    1989-07-01

    Fetuses were collected from four Mexican free-tailed bats (Tadarida brasiliensis mexicana) and a fetal bat cell (FBC) line was established and tested for its ability to support the replication of the ERA vaccine strain of rabies virus. Cytopathic effects were detected in ERA virus-inoculated as well as uninoculated FBC's. Immunofluorescent antibody testing of uninoculated FBC's provided no evidence for the presence of rabies virus. However, mice inoculated intracranially with supernatant fluid from uninoculated FBC's died. Enzyme-linked immunosorbent assay and immunofluorescent antibody testing revealed rabies virus in the brains of these mice. Tests with a panel of monoclonal antibodies indicated that the isolate was the same as that isolated from Mexican free-tailed bats from the southwestern United States. We conclude that the fetuses from which the FBC line was derived had been infected in utero with rabies virus. We believe this may represent the first observation of prenatal transfer of rabies virus in naturally infected bats.

  19. Scanning and three-dimensional electron microscopy methods for the study of Trypanosoma brucei and Leishmania mexicana flagella.

    PubMed

    Gluenz, Eva; Wheeler, Richard John; Hughes, Louise; Vaughan, Sue

    2015-01-01

    Three-dimensional electron microscopy tools have revolutionized our understanding of cell structure and molecular complexes in biology. Here, we describe methods for studying flagellar ultrastructure and biogenesis in two unicellular parasites-Trypanosoma brucei and Leishmania mexicana. We describe methods for the preparation of these parasites for scanning electron microscopy cellular electron tomography, and serial block face scanning electron microscopy (SBFSEM). These parasites have a highly ordered cell shape and form, with a defined positioning of internal cytoskeletal structures and organelles. We show how knowledge of these can be used to dissect cell cycles in both parasites and identify the old flagellum from the new in T. brucei. Finally, we demonstrate the use of SBFSEM three-dimensional models for analysis of individual whole cells, demonstrating the excellent potential this technique has for future studies of mutant cell lines.

  20. Periacineta mexicana n. sp. (Ciliophora, Suctoria, Discophryida), epizoic on Mexican backswimmers of the genus Buenoa (Insecta, Hemiptera, Notonectidae).

    PubMed

    Mariño-Pérez, Ricardo; Mayén-Estrada, Rosaura; Dovgal, Igor V

    2010-01-01

    A new species of suctorian in the genus Periacineta, epibiotic on aquatic bugs (Hemiptera, Heteroptera, Nepomorpha), is described on the basis of morphological characteristics of the cell body, lorica, tentacular placement, and stalk, and its 18S rRNA partial sequence gene. Periacineta mexicana n. sp. is a loricate suctorian with elongate body and rounded apical region; tentacles are distributed randomly over apical region and not grouped into fascicles. Macronucleus in adult is elongate and located centrally. The suctorian usually forms closely aggregated pseudocolonies. We provide morphological data based on optical and scanning electron microscopy. A comparison with similar congeners, and emended diagnosis of the genus Periacineta also are provided. The ciliates were found attached to the first two pairs of legs of Mexican notonectids Buenoa pallens and Buenoa spp. (backswimmers).

  1. Central nervous system effects and chemical composition of two subspecies of Agastache mexicana; an ethnomedicine of Mexico.

    PubMed

    Estrada-Reyes, Rosa; López-Rubalcava, C; Ferreyra-Cruz, Octavio Alberto; Dorantes-Barrón, Ana María; Heinze, G; Moreno Aguilar, Julia; Martínez-Vázquez, Mariano

    2014-04-11

    Agastache mexicana subspecies mexicana (Amm) and xolocotziana (Amx) are used in Mexican traditional medicine to relief cultural affiliation syndromes known as "susto" or "espanto", for "nervous" condition, and as a sleep aid. Despite its intensive use, neuropharmacological studies are scarce, and the chemical composition of the aqueous extracts has not been described. Aims of the study are: (1) To analyze the chemical composition of aqueous extracts from aerial parts of Amm and Amx. (2) To evaluate the anxiolytic-like, sedative, antidepressant-like effects. (3) Analyze the general toxic effects of different doses. Anxiolytic-like and sedative effects were measured in the avoidance exploratory behavior, burying behavior and the hole-board tests. The antidepressant-like actions were studied in the forced swimming and tail suspension tests. Finally, general activity and motor coordination disturbances were evaluated in the open field, inverted screen and rota-rod tests. The acute toxicity of Amm and Amx was determined by calculating their LD50 (mean lethal dose). The chemical analyses were performed employing chromatographic, photometric and HPLC-ESI-MS techniques. Low doses of Amm and Amx (0.1σ1.0mg/kg) induced anxiolytic-like actions; while higher doses (over 10mg/kg) induced sedation and reduced the locomotor activity, exerting a general inhibition in the central nervous system (CNS). Results support the use of Amm and Amx in traditional medicine as tranquilizers and sleep inducers. Additionally, this paper contributes to the knowledge of the chemical composition of the aqueous extracts of these plants. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. HPLC/MS analysis and anxiolytic-like effect of quercetin and kaempferol flavonoids from Tilia americana var. mexicana.

    PubMed

    Aguirre-Hernández, Eva; González-Trujano, Ma Eva; Martínez, Ana Laura; Moreno, Julia; Kite, Geoffrey; Terrazas, Teresa; Soto-Hernández, Marcos

    2010-01-08

    Around the world, Tilia species have been used in traditional medicine for their properties as tranquilizer. Furthermore, Mexican species of Tilia have been grouped as Tilia americana var. mexicana, but their specific content in flavonoids is poorly described. In this study, inflorescences of Mexican Tilia were collected in three different regions of Mexico to compare their flavonoid content and anxiolytic-like response. Flavonoid content was analyzed by using an HPLC-MS technique. For anxiolytic-like response, Tilia inflorescences extracts (from 10 to 300 mg/kg, i.p.) were tested in experimental models (open-field, hole-board and plus-maze tests, as well as sodium pentobarbital-induced hypnosis) in mice. HPLC-MS analysis revealed specific peaks of flavonoid composition demonstrating some differences in these compounds in flowers and bracts depending on the region of collection. No differences in the neuropharmacological activity among these samples of Tilia were found. Moreover, their effects were associated with quercetin and kaempferol glycosides. Dissimilarities in the flavonoid composition of Mexican Tilias might imply that these species must be re-classified in more than one species, not as a unique Tilia americana var. mexicana. Since quercetin and kaempferol aglycons demonstrated anxiolytic-like response and that no difference in the pharmacological evaluation was observed between these three Mexican Tilias, we suggest that this pharmacological effect of Tilia inflorescences involves these flavonoids occurrence independently of the kind of glycosides present in the samples reinforcing their use in traditional medicine in several regions of Mexico. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

  3. The role of Revista Mexicana de Astronomía y Astrofísica Serie de Conferencias in the world of astronomy

    NASA Astrophysics Data System (ADS)

    Torres-Peimbert, Silvia; Allen, Christine

    2015-08-01

    Forty years ago Revista Mexicana de Astronomía y Astrofísica decided to include the proceedings of astronomical meetings in Mexico and Latin America. In 1995 it became necessary to found the Serie de Conferencias to better differentiate proceedings from refereed papers.So far there have been 58 astronomical meetings published and there are several more in store for the coming years

  4. Sand flies naturally infected by Leishmania (L.) mexicana in the peri-urban area of Chetumal city, Quintana Roo, México.

    PubMed

    Sánchez-García, Laura; Berzunza-Cruz, Miriam; Becker-Fauser, Ingeborg; Rebollar-Téllez, Eduardo A

    2010-06-01

    The surveillance of prevalent Leishmania sand fly vectors is an important issue for epidemiological studies in populated areas where leishmaniasis is endemic. In this study, we collected sand flies from a peri-urban area in the southeast of Mexico. Natural infection with Leishmania (L.) mexicana was studied by PCR using a Leishmania internal transcribed spacer of the ribosomal RNA gene for amplification. Infected Lutzomyia olmeca olmeca, Lu. shannoni and Lu. cruciata sand flies were collected mainly during the high transmission season (November to March), coinciding with the highest sand fly densities. Additionally, positive specimens of Lu. olmeca olmeca were also captured during July and August. The infected sand flies were from primary forest (subperennial forest) and secondary forest (18-25 years old and 10-15 years old respectively). Sand flies collected with Disney and Shannon traps were the ones found to be infected with L. (L.) mexicana. We conclude that the high-risk period in which L. (L.) mexicana is transmitted in the peri-urban area of Chetumal City is from July to March and that transmission is associated with both the subperennial forest and the secondary forest. 2010 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

  5. Comparison of small mammal prevalence of Leishmania (Leishmania) mexicana in five foci of cutaneous leishmaniasis in the State of Campeche, Mexico.

    PubMed

    Van Wynsberghe, N R; Canto-Lara, S B; Sosa-Bibiano, E I; Rivero-Cárdenas, N A; Andrade-Narváez, F J

    2009-01-01

    In the Yucatan Peninsula of Mexico, 95% of the human cases of Cutaneous Leishmaniasis are caused by Leishmania (Leishmania) mexicana with an incidence rate of 5.08 per 100,000 inhabitants. Transmission is limited to the winter months (November to March). One study on wild rodents has incriminated Ototylomys phyllotis and Peromyscus yucatanicus as primary reservoirs of L. (L.) mexicana in the focus of La Libertad, Campeche. In the present study, the prevalence of both infection and disease caused by L. (L.) mexicana in small terrestrial mammals were documented during five transmission seasons (1994-2004) in five foci of Leishmaniasis in the state of Campeche. Foci separated by only 100 km, with similar relative abundances of small mammals, were found to differ significantly in their prevalence of both symptoms and infection. Transmission rates and reservoir species seemed to change in space as well as in time which limited the implementation of effective control measures of the disease even in a small endemic area such as the south of the Yucatan Peninsula.

  6. Leishmania spp: temperature sensitivity of promastigotes in vitro as a model for tropism in vivo.

    PubMed

    Callahan, H L; Portal, I F; Bensinger, S J; Grogl, M

    1996-12-01

    Since in humans, skin temperature is lower than internal temperature, the temperature sensitivity of Leishmania may influence the tropism of Leishmania in the human host; temperature-sensitive parasites may remain in the skin, temperature-resistant parasites may go to the viscera. In order to pursue the genetic factors controlling Leishmania tropism, we have developed an in vitro promastigote temperature model. Promastigote growth is measured at 30, 32, and 34 degrees C and compared with growth at the control temperature (25 degrees C). The results from tests of the promastigote temperature sensitivity of eight species (33 different strains) show that visceral species (L. donovani and L. chagasi) are more temperature resistant than cutaneous species (L. major, L. tropica, L. mexicana, L. braziliensis, L. panamensis, and L. amazonensis), that Old World species are more temperature-resistant than New World species, and that within the New World cutaneous species there are three distinct temperature sensitivity groupings (L. mexicana > L. braziliensis and L. panamensis > L. amazonensis). Interestingly, viscerotropic L. tropica from Operation Desert Storm and L. donovani complex strains isolated from cutaneous lesions are more and less temperature-sensitive, respectively, than strains of the same species with the expected tropism in vivo.

  7. Proteome profiling of the growth phases of Leishmania pifanoi promastigotes in axenic culture reveals differential abundance of immunostimulatory proteins.

    PubMed

    Alcolea, Pedro J; Alonso, Ana; García-Tabares, Francisco; Mena, María del Carmen; Ciordia, Sergio; Larraga, Vicente

    2016-06-01

    Leishmaniasis is a term that encompasses a compendium of neglected tropical diseases caused by dimorphic and digenetic protozoan parasites from the genus Leishmania (Kinetoplastida: Trypanosomatidae). The clinical manifestations of neotropical cutaneous leishmaniasis (NCL) caused by Leishmania pifanoi and other species of the "Leishmania mexicana complex" mainly correspond to anergic diffuse cutaneous leishmaniasis (ADCL), which is the origin of considerable morbidity. Despite the outstanding advances in the characterization of the trypanosomatid genomes and proteomes, the biology of this species has been scarcely explored. However, the close relation of L. pifanoi to the sequenced species L. mexicana and others included in the "L. mexicana complex" allowed us to perform a two-dimension electrophoresis (2DE) approach to the promastigote proteome at the differential expression level. Protein identifications were performed by matrix-assisted laser desorption-ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF). This insight has revealed similarities and differences between L. pifanoi and other species responsible for cutaneous and visceral leishmaniasis. Interestingly, certain proteins that were previously described as immunostimulatory (elongation factor 1β, trypanothione peroxidase, heat shock protein 70, enolase, GDP-forming succinyl-CoA and aldehyde dehydrogenase) are more abundant in the final growth stages of promastigotes (late-logarithmic and/or stationary phase) in the case of L. pifanoi.

  8. Bio Fabrication of Silver Nanoparticle from Argemone mexicana for the Control of Aedes albopictus and their Antimicrobial Activity.

    PubMed

    Kamalakannan, Siva; Ananth, Sivapunyam; Murugan, Kadarkarai; Kovendan, Kalimuthu; Ramar, Marimuthu; Arumugam, Ponnan; Chandramohan, Balamurugan; Balachandar, Vellingiri

    Plant synthesized silver nanoparticles give rapid control on mosquito larvae of dengue vector, Aedes albopictus. AgNPs synthesized from the plant, Argemone mexicana for the control of larvae and these nanoparticles inhibit the growth of microbes are broad spectrum of nanoparticle activities. Nanoparticles were subjected to analysis by UV-vis spectrophotometry, Fourier transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. Furthermore, laboratory evaluation of plant mediated nano-particle carried out lethal toxicity on Aedes albopictus. The characterization studies confirmed the spherical shape and size (5-50 nm) of silver nano-particles. The efficacy of AgNPs was tested at concentration of 2 to 10 ppm against L1 to L4 larval instar of A. albopictus. The LC50 followed by LC90 values were (L1) 5.24, 8.66; (L2) 5.56, 8.85; (L3) 6.20, 10.01 and (L4) 7.04, 10.92 at 10 ppm of silver nanoparticle, whereas LC50 (LC90) values of (L1) 7.63, 11.58; (L2) 8.17, 11.88; 8.80, 12.82 and 8.94, 12.26 at 10 ppm of plant extract alone treated larvae, respectively. The mortality rates were positively correlated with the concentration of AgNPs. Significant (P<0.05) high square value changes in the larval mortality were also recorded between the period of exposure against all larval instar of A. albopictus. Silver nanoparticles were also tested for antimicrobial activity and significant toxicity inhibition was observed against the gram positive microbes and it exhibited mild toxicity against P. aeroginosa. Plant, A. mexicana synthesized silver nano-particles are rapid and potential mosquito larvicidal as well as antimicrobial agents. Finding of our results support that silver nanoparticles can be prepared in a simple and cost-effective manner and are suitable for bio-formulation against mosquitoes and microbes.

  9. Acarine infracommunities associated with the Mexican free-tailed bat, Tadarida brasiliensis mexicana (Chiroptera: Molossidae) in arid regions of Mexico.

    PubMed

    Guzmán-Cornejo, C; García-Prieto, L; Morales-Malacara, J B; Pérez-Ponce De León, G

    2003-11-01

    The Mexican free-tailed bat, Tadarida brasiliensis mexicana, is one of the most widely distributed bats, and its range includes the whole Mexican territory. Ectoparasites of this bat have been the subject of isolated reports, but no studies of its community ecology have been conducted. The acarine infracommunities associated with this bat were analyzed, comparing bat populations from three arid regions of Mexico: an abandoned factory in Nombre de Dios, Durango; a cave in Santiago, Nuevo León; and a church in Concepción del Oro, Zacatecas. The acarine infracommunity in Nuevo Le6n's bats exhibited the highest levels of diversity as reflected by a higher richness, a lower dominance, and a moderate and relatively homogeneous abundance in this locality in relation to the other two. This pattern is influenced by stable cave conditions relative to artificial habitats. Notwithstanding, further studies are required to determine whether or not different habitat conditions are a primary factor in the process of structuring the acari infracommunities.

  10. Parasitic infections of three Mexican howler monkey groups (Alouatta palliata mexicana) living in forest fragments in Mexico.

    PubMed

    Cristóbal-Azkarate, Jurgi; Hervier, Blanca; Vegas-Carrillo, Sira; Osorio-Sarabia, David; Rodríguez-Luna, Ernesto; Veà, Joaquim J

    2010-07-01

    In order to better understand how patterns of parasitism in howler monkeys are affected by forest fragmentation, we carried out a 1 year survey of gastrointestinal parasites in fecal samples from three groups of Mexican howler monkeys inhabiting different forest fragments in the Los Tuxtlas Biosphere Reserve, Mexico. The study groups were chosen because the conditions in which they lived suggested a potentially negative gradient for parasite richness and a positive gradient for levels of parasitism. We report for the first time the presence of Entamoeba coli in Alouatta palliata mexicana and of hookworms (Family Ancylostomidae) in A. palliata. A reduction in home range size and an increase in disturbance was associated with a loss of parasite richness, which in general was high. Parasite prevalence and the proportion of contaminated samples in which each parasite taxon was present was also high in general and there were no differences between groups. A factor related to the generally high levels of parasitism in our study groups could be the high humidity in the study area, because this favors the survival of parasitic free forms and increases the chances of infection. This would also account for the tendency towards higher levels of parasitism observed in the rainy season. Finally we did not find a pattern relating sex and parasitism.

  11. Horsehair worms (Gordius robustus in nests of the western bluebird (Sialia mexicana): evidence for anti-predator avoidance?

    PubMed

    Fair, Jeanne M; Hanelt, Ben; Burnett, Kassidy

    2010-04-01

    Hairworms (Nematomorpha: Gordiida) are internal parasites that alter the behavior of their terrestrial insect host, forcing it to enter the water to reach its reproductive habitat. After reproduction of the free-living adults, the larvae encyst in aquatic insects and are retained upon metamorphosis of the insect into an adult fly. This paratenic host links the aquatic and terrestrial environments after its consumption by omnivorous or predatory insects. Therefore, hairworms are usually only associated with invertebrates, and few reports discuss hairworm interactions with vertebrate species. Here, we report on the finding of horsehair worms in nests of a cavity-nesting bird species in Los Alamos County, New Mexico. From 2004 to 2008, 7 nests within nest boxes occupied by the western bluebird (Sialia mexicana) contained 8 hairworms that were identified as Gordius robustus. All of the nest boxes with worms were less than 100 m from stagnant or low-flowing streams. The most likely explanation for the presence of the worms in the nests is that worms engaged in anti-predator avoidance after their insect hosts were collected and before digestion by nestling birds.

  12. Sex-specific local life-history adaptation in surface- and cave-dwelling Atlantic mollies (Poecilia mexicana)

    PubMed Central

    Riesch, Rüdiger; Reznick, David N.; Plath, Martin; Schlupp, Ingo

    2016-01-01

    Cavefishes have long been used as model organisms showcasing adaptive diversification, but does adaptation to caves also facilitate the evolution of reproductive isolation from surface ancestors? We raised offspring of wild-caught surface- and cave-dwelling ecotypes of the neotropical fish Poecilia mexicana to sexual maturity in a 12-month common garden experiment. Fish were raised under one of two food regimes (high vs. low), and this was crossed with differences in lighting conditions (permanent darkness vs. 12:12 h light:dark cycle) in a 2 × 2 factorial design, allowing us to elucidate potential patterns of local adaptation in life histories. Our results reveal a pattern of sex-specific local life-history adaptation: Surface molly females had the highest fitness in the treatment best resembling their habitat of origin (high food and a light:dark cycle), and suffered from almost complete reproductive failure in darkness, while cave molly females were not similarly affected in any treatment. Males of both ecotypes, on the other hand, showed only weak evidence for local adaptation. Nonetheless, local life-history adaptation in females likely contributes to ecological diversification in this system and other cave animals, further supporting the role of local adaptation due to strong divergent selection as a major force in ecological speciation. PMID:26960566

  13. Otolith morphology and hearing abilities in cave- and surface-dwelling ecotypes of the Atlantic molly, Poecilia mexicana (Teleostei: Poeciliidae)

    PubMed Central

    Schulz-Mirbach, Tanja; Ladich, Friedrich; Riesch, Rüdiger; Plath, Martin

    2010-01-01

    Cave fish have rarely been investigated with regard to their inner ear morphology, hearing abilities, and acoustic communication. Based on a previous study that revealed morphological differences in the saccular otolith between a cave and two surface populations of Poecilia mexicana, we checked for additional differences in utricular and lagenar otoliths and tested whether different populations have similar hearing sensitivities. We found pronounced differences in the shape of all three otoliths. Otoliths of the saccule and lagena from cave fish differed from those of surface fish in the features of the face oriented towards the sensory epithelium. In addition, otoliths of the utricle and lagena were significantly heavier in cave fish. Auditory sensitivities were measured between 100 and 1500 Hz, utilizing the auditory evoked potential recording technique. We found similar hearing abilities in cave and surface fish, with greatest sensitivity between 200 and 300 Hz. An acoustic survey revealed that neither ecotype produced species-specific sounds. Our data indicate that cave dwelling altered the otolith morphology in Atlantic mollies, probably due to metabolic differences. Different otolith morphology, however, did not affect general auditory sensitivity or acoustic behavior. PMID:20430090

  14. Toxic hydrogen sulfide and dark caves: life-history adaptations in a livebearing fish (Poecilia mexicana, Poeciliidae).

    PubMed

    Riesch, Rüdiger; Plath, Martin; Schlupp, Ingo

    2010-05-01

    Life-history traits are very sensitive to extreme environmental conditions, because resources that need to be invested in somatic maintenance cannot be invested in reproduction. Here we examined female life-history traits in the Mexican livebearing fish Poecilia mexicana from a variety of benign surface habitats, a creek with naturally occurring toxic hydrogen sulfide (H2S), a sulfidic cave, and a non-sulfidic cave. Previous studies revealed pronounced genetic and morphological divergence over very small geographic scales in this system despite the absence of physical barriers, suggesting that local adaptation to different combinations of two selection factors, toxicity (H2S) and darkness, is accompanied by very low rates of gene flow. Hence, we investigated life-history divergence between these populations in response to the selective pressures of darkness and/or toxicity. Our main results show that toxicity and darkness both select for (or impose constraints on) the same female trait dynamics: reduced fecundity and increased offspring size. Since reduced fecundity in the sulfur cave population was previously shown to be heritable, we discuss how divergent life-history evolution may promote further ecological divergence: for example, reduced fecundity and increased offspring autonomy are clearly beneficial in extreme environments, but fish with these traits are outcompeted in benign habitats.

  15. Assessing the importance of four sandfly species (Diptera: Psychodidae) as vectors of Leishmania mexicana in Campeche, Mexico.

    PubMed

    Pech-May, A; Peraza-Herrera, G; Moo-Llanes, D A; Escobedo-Ortegón, J; Berzunza-Cruz, M; Becker-Fauser, I; Montes DE Oca-Aguilar, A C; Rebollar-Téllez, E A

    2016-09-01

    Localized cutaneous leishmaniasis represents a public health problem in many areas of Mexico, especially in the Yucatan Peninsula. An understanding of vector ecology and bionomics is of great importance in evaluations of the transmission dynamics of Leishmania parasites. A field study was conducted in the county of Calakmul, state of Campeche, during the period from November 2006 to March 2007. Phlebotomine sandfly vectors were sampled using Centers for Disease Control light traps, baited Disney traps and Shannon traps. A total of 3374 specimens were captured in the two villages of Once de Mayo (93.8%) and Arroyo Negro (6.1%). In Once de Mayo, the most abundant species were Psathyromyia shannoni, Lutzomyia cruciata, Bichromomyia olmeca olmeca and Psychodopygus panamensis (all: Diptera: Psychodidae). The Shannon trap was by far the most efficient method of collection. The infection rate, as determined by Leishmania mexicana-specific polymerase chain reaction, was 0.3% in Once de Mayo and infected sandflies included Psy. panamensis, B. o. olmeca and Psa. shannoni. There were significant differences in human biting rates across sandfly species and month of sampling. Ecological niche modelling analyses showed an overall overlap of 39.1% for the four species in the whole state of Campeche. In addition, the finding of nine vector-reservoir pairs indicates a potential interaction. The roles of the various sandfly vectors in Calakmul are discussed. © 2016 The Royal Entomological Society.

  16. Choosy males from the underground: male mating preferences in surface- and cave-dwelling Atlantic mollies ( Poecilia mexicana)

    NASA Astrophysics Data System (ADS)

    Plath, Martin; Seggel, Uta; Burmeister, Heike; Heubel, Katja U.; Schlupp, Ingo

    2006-03-01

    Atlantic mollies ( Poecilia mexicana) inhabit a variety of surface habitats, but they also occur in a sulfur cave in southern Mexico. We examined male mate choice relative to female body size in the cave population and in the most closely related surface-dwelling population from a nearby river. Males from both populations were either light- or dark-reared and could choose between two differently sized females either on the basis of visual cues in light or on the basis of solely nonvisual cues in darkness. Sexual preferences were estimated from the degree of association. Cave molly males always showed a preference for the larger female, both in light and in darkness. Among the surface males, only light-reared males showed a preference in the visual cues test, but not in darkness. In a control experiment, we demonstrated that male association preferences directly translate into actual mating preferences. Apparently, using visual cues for mate choice is the ancestral state in this system, and using nonvisual cues has evolved as a novel trait in the cave population. We discuss the evolution of nonvisual male mate choice in the context of changed environmental conditions, namely the absence of light, hypoxia, and toxic hydrogen sulfide in the cave.

  17. Sex-specific local life-history adaptation in surface- and cave-dwelling Atlantic mollies (Poecilia mexicana).

    PubMed

    Riesch, Rüdiger; Reznick, David N; Plath, Martin; Schlupp, Ingo

    2016-03-10

    Cavefishes have long been used as model organisms showcasing adaptive diversification, but does adaptation to caves also facilitate the evolution of reproductive isolation from surface ancestors? We raised offspring of wild-caught surface- and cave-dwelling ecotypes of the neotropical fish Poecilia mexicana to sexual maturity in a 12-month common garden experiment. Fish were raised under one of two food regimes (high vs. low), and this was crossed with differences in lighting conditions (permanent darkness vs. 12:12 h light:dark cycle) in a 2 × 2 factorial design, allowing us to elucidate potential patterns of local adaptation in life histories. Our results reveal a pattern of sex-specific local life-history adaptation: Surface molly females had the highest fitness in the treatment best resembling their habitat of origin (high food and a light:dark cycle), and suffered from almost complete reproductive failure in darkness, while cave molly females were not similarly affected in any treatment. Males of both ecotypes, on the other hand, showed only weak evidence for local adaptation. Nonetheless, local life-history adaptation in females likely contributes to ecological diversification in this system and other cave animals, further supporting the role of local adaptation due to strong divergent selection as a major force in ecological speciation.

  18. Crystal structures of Leishmania mexicana arginase complexed with α,α-disubstituted boronic amino-acid inhibitors.

    PubMed

    Hai, Yang; Christianson, David W

    2016-04-01

    Leishmania arginase is a potential drug target for the treatment of leishmaniasis because this binuclear manganese metalloenzyme initiates de novo polyamine biosynthesis by catalyzing the hydrolysis of L-arginine to generate L-ornithine and urea. The product L-ornithine subsequently undergoes decarboxylation to yield putrescine, which in turn is utilized for spermidine biosynthesis. Polyamines such as spermidine are essential for the growth and survival of the parasite, so inhibition of enzymes in the polyamine-biosynthetic pathway comprises an effective strategy for treating parasitic infections. To this end, two X-ray crystal structures of L. mexicana arginase complexed with α,α-disubstituted boronic amino-acid inhibitors based on the molecular scaffold of 2-(S)-amino-6-boronohexanoic acid are now reported. Structural comparisons with human and parasitic arginase complexes reveal interesting differences in the binding modes of the additional α-substituents, i.e. the D side chains, of these inhibitors. Subtle differences in the three-dimensional contours of the outer active-site rims among arginases from different species lead to different conformations of the D side chains and thus different inhibitor-affinity trends. The structures suggest that it is possible to maintain affinity while fine-tuning intermolecular interactions of the D side chain of α,α-disubstituted boronic amino-acid inhibitors in the search for isozyme-specific and species-specific arginase inhibitors.

  19. Isolation of Leishmania (L.) mexicana from wild rodents and their possible role in the transmission of localized cutaneous leishmaniasis in the state of Campeche, Mexico.

    PubMed

    Chable-Santos, J B; Van Wynsberghe, N R; Canto-Lara, S B; Andrade-Narvaez, F J

    1995-08-01

    Leishmania parasites were isolated from four of seven small rodent species captured in the State of Campeche, Mexico. Signs and/or symptoms of leishmanial infection were restricted to the tail of the mice. Peromyscus yucatanicus endemic to the peninsula of Yucatan and Oryzomys melanotis were added to the list of carriers of Leishmania. Leishmania (L.) mexicana, characterized by an indirect immunofluorescence antibody method using monoclonal antibodies, was identified in one Sigmodon hispidus and one Or. melanotis. The possible role of the different species as primary reservoirs of Leishmania in the peninsula of Yucatan is discussed.

  20. Growth and enzymatic activity of Leucoagaricus gongylophorus, a mutualistic fungus isolated from the leaf-cutting ant Atta mexicana, on cellulose and lignocellulosic biomass.

    PubMed

    Vigueras, G; Paredes-Hernández, D; Revah, S; Valenzuela, J; Olivares-Hernández, R; Le Borgne, S

    2017-08-01

    A mutualistic fungus of the leaf-cutting ant Atta mexicana was isolated and identified as Leucoagaricus gongylophorus. This isolate had a close phylogenetic relationship with L. gongylophorus fungi cultivated by other leaf-cutting ants as determined by ITS sequencing. A subcolony started with ~500 A. mexicana workers could process 2 g day(-1) of plant material and generate a 135 cm(3) fungus garden in 160 days. The presence of gongylidia structures of ~35 μm was observed on the tip of the hyphae. The fungus could grow without ants on semi-solid cultures with α-cellulose and microcrystalline cellulose and in solid-state cultures with grass and sugarcane bagasse, as sole sources of carbon. The maximum CO2 production rate on grass (Vmax  = 17·5 mg CO2  Lg(-1)  day(-1) ) was three times higher than on sugarcane bagasse (Vmax  = 6·6 mg CO2  Lg(-1) day(-1) ). Recoveries of 32·9 mgglucose  gbiomass(-1) and 12·3 mgglucose  gbiomass(-1) were obtained from the fungal biomass and the fungus garden, respectively. Endoglucanase activity was detected on carboxymethylcellulose agar plates. This is the first study reporting the growth of L. gongylophorus from A. mexicana on cellulose and plant material. According to the best of our knowledge, this is the first report about the growth of Leucoagaricus gongylophorus, isolated from the colony of the ant Atta mexicana, on semisolid medium with cellulose and solid-state cultures with lignocellulosic materials. The maximum CO2 production rate on grass was three times higher than on sugarcane bagasse. Endoglucanase activity was detected and it was possible to recover glucose from the fungal gongylidia. The cellulolytic activity could be used to process lignocellulosic residues and obtain sugar or valuable products, but more work is needed in this direction. © 2017 The Society for Applied Microbiology.

  1. Anticonvulsant and Antioxidant Effects of Tilia americana var. mexicana and Flavonoids Constituents in the Pentylenetetrazole-Induced Seizures

    PubMed Central

    Cárdenas-Rodríguez, Noemí; González-Trujano, María Eva; Aguirre-Hernández, Eva; Ruíz-García, Matilde; Sampieri, Aristides; Coballase-Urrutia, Elvia; Carmona-Aparicio, Liliana

    2014-01-01

    Tilia genus is commonly used around the world for its central nervous system properties; it is prepared as tea and used as tranquilizing, anticonvulsant, and analgesic. In this study, anticonvulsant activity of the Tilia americana var. mexicana inflorescences and leaves was investigated by evaluating organic and aqueous extracts (100, 300, and 600 mg/kg, i.p.) and some flavonoids in the pentylenetetrazole-induced seizures in mice. Moreover, antioxidant effect of these extracts and flavonoids was examined in an in vitro study by using spectrophotometric technique. Significant activity was observed in the methanol extract from inflorescences. An HPLC analysis of the methanol extract from inflorescences and leaves of Tilia allowed demonstrating the respective presence of some partial responsible flavonoid constituents: quercetin (20.09 ± 1.20 μg/mg and 3.39 ± 0.10 μg/mg), rutin (3.52 ± 0.21 μg/mg and 8.94 ± 0.45 μg/mg), and isoquercitrin (1.74 ± 0.01 μg/mg and 1.24 ± 0.13 μg/mg). In addition, significant but different antioxidant properties were obtained among the flavonoids and the extracts investigated. Our results provide evidence of the anticonvulsant activity of Tilia reinforcing its utility for central nervous system diseases whose mechanism of action might involve partial antioxidant effects due to the presence of flavonoids. PMID:25197430

  2. Prevalence of rabies specific antibodies in the Mexican free-tailed bat (Tadarida brasiliensis mexicana) at Lava Cave, New Mexico.

    PubMed

    Steece, R; Altenbach, J S

    1989-10-01

    Adult female and juvenile Mexican free-tailed bats (Tadarida brasiliensis mexicana) were collected bimonthly at Lava Cave, New Mexico from May through September. The purpose of this study was to examine the prevalence of active rabies infection as well as to determine individual immune status in these hosts. All bats were bled and examined for rabies antibody (total antibody versus IgM) utilizing a modified serum neutralization test. The brains were removed and examined by the fluorescent rabies antibody (FRA) test. No significant difference was observed in the number of adults with rabies neutralizing antibody (total) over the study period. Significant differences in rabies neutralizing antibody (total) were observed among the juveniles sampled during July and August. The number of adults with IgM specific antibody was low (15 of 750, 2%) and did not fluctuate significantly. However, the number of juveniles with IgM antibody did show increased levels in August and September. The number of adults positive by the FRA was low (4 of 750, less than 1%) and did not appear to fluctuate significantly over the study period. The number of juveniles positive by the FRA was three and one-half times higher than observed for the adults (14 of 600, 2%). These results indicate that the Mexican free-tailed bat appears to be exposed to rabies virus shortly after birth as evident by its immune status. The low prevalence (4 of 750, less than 1%) of active infection as determined by the FRA and mouse inoculation and the high prevalence (514 of 750, 69%) of IgG antibody in the adult females indicate that the Mexican free-tailed bat recovers from rabies virus infection.

  3. Comparative analysis of the gonadal transcriptomes of the all-female species Poecilia formosa and its maternal ancestor Poecilia mexicana

    PubMed Central

    2014-01-01

    Background The Amazon molly, Poecilia formosa (Teleostei: Poeciliinae) is an unisexual, all-female species. It evolved through the hybridisation of two closely related sexual species and exhibits clonal reproduction by sperm dependent parthenogenesis (or gynogenesis) where the sperm of a parental species is only used to activate embryogenesis of the apomictic, diploid eggs but does not contribute genetic material to the offspring. Here we provide and describe the first de novo assembled transcriptome of the Amazon molly in comparison with its maternal ancestor, the Atlantic molly Poecilia mexicana. The transcriptome data were produced through sequencing of single end libraries (100 bp) with the Illumina sequencing technique. Results 83,504,382 reads for the Amazon molly and 81,625,840 for the Atlantic molly were assembled into 127,283 and 78,961 contigs for the Amazon molly and the Atlantic molly, respectively. 63% resp. 57% of the contigs could be annotated with gene ontology terms after sequence similarity comparisons. Furthermore, we were able to identify genes normally involved in reproduction and especially in meiosis also in the transcriptome dataset of the apomictic reproducing Amazon molly. Conclusions We assembled and annotated the transcriptome of a non-model organism, the Amazon molly, without a reference genome (de novo). The obtained dataset is a fundamental resource for future research in functional and expression analysis. Also, the presence of 30 meiosis-specific genes within a species where no meiosis is known to take place is remarkable and raises new questions for future research. PMID:24742317

  4. Anticonvulsant and antioxidant effects of Tilia americana var. mexicana and flavonoids constituents in the pentylenetetrazole-induced seizures.

    PubMed

    Cárdenas-Rodríguez, Noemí; González-Trujano, María Eva; Aguirre-Hernández, Eva; Ruíz-García, Matilde; Sampieri, Aristides; Coballase-Urrutia, Elvia; Carmona-Aparicio, Liliana

    2014-01-01

    Tilia genus is commonly used around the world for its central nervous system properties; it is prepared as tea and used as tranquilizing, anticonvulsant, and analgesic. In this study, anticonvulsant activity of the Tilia americana var. mexicana inflorescences and leaves was investigated by evaluating organic and aqueous extracts (100, 300, and 600 mg/kg, i.p.) and some flavonoids in the pentylenetetrazole-induced seizures in mice. Moreover, antioxidant effect of these extracts and flavonoids was examined in an in vitro study by using spectrophotometric technique. Significant activity was observed in the methanol extract from inflorescences. An HPLC analysis of the methanol extract from inflorescences and leaves of Tilia allowed demonstrating the respective presence of some partial responsible flavonoid constituents: quercetin (20.09 ± 1.20 μg/mg and 3.39 ± 0.10 μg/mg), rutin (3.52 ± 0.21 μg/mg and 8.94 ± 0.45 μg/mg), and isoquercitrin (1.74 ± 0.01 μg/mg and 1.24 ± 0.13 μg/mg). In addition, significant but different antioxidant properties were obtained among the flavonoids and the extracts investigated. Our results provide evidence of the anticonvulsant activity of Tilia reinforcing its utility for central nervous system diseases whose mechanism of action might involve partial antioxidant effects due to the presence of flavonoids.

  5. PPAR Activation Induces M1 Macrophage Polarization via cPLA2-COX-2 Inhibition, Activating ROS Production against Leishmania mexicana

    PubMed Central

    Díaz-Gandarilla, J. A.; Osorio-Trujillo, C.; Hernández-Ramírez, V. I.; Talamás-Rohana, P.

    2013-01-01

    Defence against Leishmania depends upon Th1 inflammatory response and, a major problem in susceptible models, is the turnoff of the leishmanicidal activity of macrophages with IL-10, IL-4, and COX-2 upregulation, as well as immunosuppressive PGE2, all together inhibiting the respiratory burst. Peroxisome proliferator-activated receptors (PPAR) activation is responsible for macrophages polarization on Leishmania susceptible models where microbicide functions are deactivated. In this paper, we demonstrated that, at least for L. mexicana, PPAR activation, mainly PPARγ, induced macrophage activation through their polarization towards M1 profile with the increase of microbicide activity against intracellular pathogen L. mexicana. PPAR activation induced IL-10 downregulation, whereas the production of proinflammatory cytokines such as TNF-α, IL-1β, and IL-6 remained high. Moreover, PPAR agonists treatment induced the deactivation of cPLA2-COX-2-prostaglandins pathway together with an increase in TLR4 expression, all of whose criteria meet the M1 macrophage profile. Finally, parasite burden, in treated macrophages, was lower than that in infected nontreated macrophages, most probably associated with the increase of respiratory burst in these treated cells. Based on the above data, we conclude that PPAR agonists used in this work induces M1 macrophages polarization via inhibition of cPLA2 and the increase of aggressive microbicidal activity via reactive oxygen species (ROS) production. PMID:23555077

  6. Genetic diversity and structure of wild populations of the tropical dry forest tree Jacaratia mexicana (Brassicales: Caricaceae) at a local scale in Mexico.

    PubMed

    Arias, Dulce M; Albarrán-Lara, Ana L; González-Rodríguez, Antonio; Peñaloza-Ramírez, Juan; Dorado, Oscar; Leyva, Esaú

    2012-03-01

    The tropical dry forest is a greatly endangered ecosystem, from which Jacaratia mexicana is a native tree. With the aim to assess the levels of genetic variation and population structure, four wild populations of J. mexicana were studied in the Sierra de Huautla Biosphere Reserve, Morelos, Mexico. For this, DNA was extracted from 159 individuals and were amplified with six random primers using the Random Amplified Polymorphic DNA (RAPD). A total of 54 bands were obtained, of which 50 (92.6%) were polymorphic. The total genetic diversity found within the four populations was 0.451 when estimated by Shannon's index. An AMOVA analysis showed that 84% of the total genetic variation was found within populations and 16% was among populations. The UPGMA dendrogram showed that all individuals from one of the populations (Huaxtla) formed one distinct genetic group, while the rest of the individuals did not cluster according to population. A Mantel test did not show an association between genetic and geographical distances among populations (r=0.893, p=0.20). A Bayesian cluster analysis performed with STRUCTURE, showed that the most probable number of genetic groups in the data was four (K=4), and confirmed the distinctness of Huaxtla population. Our results showed that important genetic differentiation among populations can occur even at this small geographic scale and this has to be considered in conservation actions for this genetic resource.

  7. Chemical compositions and antimicrobial and antioxidant activities of the essential oils from Magnolia grandiflora, Chrysactinia mexicana, and Schinus molle found in northeast Mexico.

    PubMed

    Guerra-Boone, Laura; Alvarez-Román, Rocío; Salazar-Aranda, Ricardo; Torres-Cirio, Anabel; Rivas-Galindo, Verónica Mayela; Waksman de Torres, Noemí; González González, Gloria María; Pérez-López, Luis Alejandro

    2013-01-01

    The essential oils from Magnolia grandiflora and Chrysactinia mexicana leaves, and from Schinus molle leaves and fruit, were characterized by gas chromatography/flame-ionization detection and gas chromatography/mass spectrometry. Twenty-eight compounds from M. grandiflora leaves were identified (representing 93.6% of the total area of the gas chromatogram), with the major component being bornyl acetate (20.9%). Colorless and yellow oils were obtained from the C. mexicana leaves with 18 (86.7%) and 11 (100%) compounds identified, respectively. In both fractions, the principal component was sylvestrene (36.8% and 41.1%, respectively). The essential oils ofS. molle leaves and fruit were each separated into colorless and yellow fractions, in which 14 (98.2) and 20 (99.8%) compounds were identified. The main component was alpha-phellandrene in all fractions (between 32.8% and 45.0%). The M. grandiflora oil displayed antifungal activity against five dermatophyte strains. The oils from S. molle and M. grandiflora leaves had antimicrobial activity against Staphylococcus aureus and Streptococcus pyogenes, which cause skin infections that potentially may lead to sepsis. However, the antioxidant activities of all oils were small (half maximal effective concentration values >250 microg/mL).

  8. Audience effects in the Atlantic molly (Poecilia mexicana)–prudent male mate choice in response to perceived sperm competition risk?

    PubMed Central

    Ziege, Madlen; Mahlow, Kristin; Hennige-Schulz, Carmen; Kronmarck, Claudia; Tiedemann, Ralph; Streit, Bruno; Plath, Martin

    2009-01-01

    Background Multidirectional interactions in social networks can have a profound effect on mate choice behavior; e.g., Poecilia mexicana males show weaker expression of mating preferences when being observed by a rival. This may be an adaptation to reduce sperm competition risk, which arises because commonly preferred female phenotypes will receive attention also from surrounding males, and/or because other males can copy the focal male's mate choice. Do P. mexicana males indeed respond to perceived sperm competition risk? We gave males a choice between two females and repeated the tests under one of the following conditions: (1) an empty transparent cylinder was presented (control); (2) another ("audience") male inside the cylinder observed the focal male throughout the 2nd part, or (3) the audience male was presented only before the tests, but could not eavesdrop during the actual choice tests (non-specific sperm competition risk treatments); (4) the focal male could see a rival male interact sexually with the previously preferred, or (5) with the non-preferred female before the 2nd part of the tests (specific sperm competition risk treatments). Results The strength of individual male preferences declined slightly also during the control treatment (1). However, this decrease was more than two-fold stronger in audience treatment (2), i.e., with non-specific sperm competition risk including the possibility for visual eavesdropping by the audience male. No audience effect was found in treatments (3) and (5), but a weak effect was also observed when the focal male had seen the previously preferred female sexually interact with a rival male (treatment 4; specific sperm competition risk). Conclusion When comparing the two 'non-specific sperm competition risk' treatments, a very strong effect was found only when the audience male could actually observe the focal male during mate choice [treatment (2)]. This suggests that focal males indeed attempt to conceal their mating

  9. Yeast extract induction of sanguinarine biosynthesis is partially dependent on the octadecanoic acid pathway in cell cultures of Argemone mexicana L., the Mexican poppy.

    PubMed

    Guízar-González, Cecilia; Monforte-González, Miriam; Vázquez-Flota, Felipe

    2016-07-01

    To analyze the involvement of the octadecanoic (OCDA) pathway in the accumulation of sanguinarine induced by yeast extract (YE) in cell suspension cultures of Argemone mexicana (Papaveraceae). Exposure to YE promoted sanguinarine accumulation. This was not observed when they were exposed to methyl jasmonate (MeJa). Use of diethyldithiocarbamic acid (DIECA), an inhibitor of the OCDA pathway, resulted in partial impairment of this response. Exogenous application of MeJa did not reverse this effect in DIECA-exposed cultures. qRT-PCR revealed that the accumulation of transcripts corresponding to the berberine bridge enzyme gene, which was induced by YE exposure, was blocked by OCDA pathway and reversed by exogenous MeJa. Interestingly, this response pattern could not be observed on dihydrobenzophenanthridine oxidase enzyme activity, which was promoted by YE, but unaffected by either OCDA or MeJa. Results suggest partial involvement of OCDA pathway in this response.

  10. A novel Zea mays ssp. mexicana L. MYC-type ICE-like transcription factor gene ZmmICE1, enhances freezing tolerance in transgenic Arabidopsis thaliana.

    PubMed

    Lu, Xiang; Yang, Lei; Yu, Mengyuan; Lai, Jianbin; Wang, Chao; McNeil, David; Zhou, Meixue; Yang, Chengwei

    2017-04-01

    The annual Zea mays ssp. mexicana L., a member of the teosinte group, is a close wild relative of maize and thus can be effectively used in maize improvement. In this study, an ICE-like gene, ZmmICE1, was isolated from a cDNA library of RNA-Seq from cold-treated seedling tissues of Zea mays ssp. mexicana L. The deduced protein of ZmmICE1 contains a highly conserved basic helix-loop-helix (bHLH) domain and C-terminal region of ICE-like proteins. The ZmmICE1 protein localizes to the nucleus and shows sumoylation when expressed in an Escherichia coli reconstitution system. In addition, yeast one hybrid assays indicated that ZmmICE1 has transactivation activities. Moreover, ectopic expression of ZmmICE1 in the Arabidopsis ice1-2 mutant increased freezing tolerance. The ZmmICE1 overexpressed plants showed lower electrolyte leakage (EL), reduced contents of malondialdehyde (MDA). The expression of downstream cold related genes of Arabidopsis C-repeat-binding factors (AtCBF1, AtCBF2 and AtCBF3), cold-responsive genes (AtCOR15A and AtCOR47), kinesin-1 member gene (AtKIN1) and responsive to desiccation gene (AtRD29A) was significantly induced when compared with wild type under low temperature treatment. Taken together, these results indicated that ZmmICE1 is the homolog of Arabidopsis inducer of CBF expression genes (AtICE1/2) and plays an important role in the regulation of freezing stress response. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  11. In situ cytokines (IL-4, IL-10, IL-12, IFN-γ) and chemokines (MCP-1, MIP-1α) gene expression in human Leishmania (Leishmania) Mexicana infection.

    PubMed

    Valencia-Pacheco, Guillermo; Loría-Cervera, Elsy Nalleli; Sosa-Bibiano, Erika Ivett; Canché-Pool, Elsy B; Vargas-Gonzalez, Alberto; Melby, Peter C; Andrade-Narvaez, Fernando J

    2014-09-01

    Crucial to the defense against Leishmania is the ability of the host to mount a cell-mediated immune response capable of controlling and/or eliminating the parasite. The composition of the cell populations recruited in the early phase of the infection seems to be essential for defining the infection outcomes. The signals that initiate and regulate the early immune response and local accumulation of cell subsets in the skin are poorly understood. We previously studied the in situ expression of cytokine genes in patients with localized cutaneous leishmaniasis (LCL) caused by Leishmania (Leishmania) mexicana. In the present study we examined in situ cytokine (IL-4, IL-10, IL-12, IFN-γ) and chemokine (MCP-1, MIP-1α) gene expression in L. (L.) mexicana active LCL lesions, and in the delayed type hypersensitivity (DTH) skin response to Leishmania antigen in subjects with healed lesion and subclinical infection. Data regarding cytokines were similar to previous studies in patients with active LCL. There were no significant differences in the profile of cytokine and chemokine gene expression in DTH from subjects with healed or subclinical infection. IL-12 gene expression detected in both groups was similar. High expression of MCP-1 was detected in all patients with active LCL. There was no difference in the level of MCP-1 expression between the healed lesion and the subclinical infection groups (p = 0.876). IL-12 and MCP-1 in the absence of IFN-γ might be playing a crucial role in infection outcomes at skin level.

  12. Forty-two years of Revista Mexicana de Astronomía y Astrofísica: Some history and musings on the future

    NASA Astrophysics Data System (ADS)

    Allen, C.; Torres-Peimbert, S.

    2017-07-01

    After 42 years of continuously publishing the Revista Mexicana de Astronomía y Astrofísica, we cast a short retrospective view on its history and we share our plans for the future. RMxAA was founded in 1974. Founding editors were P. Pishmish, E. Mendoza and S. Torres-Peimbert. RMxAA has published original research papers in all areas of astronomy, astrophysics and related fields. Until 1994 RMxAA also published the proceedings of astronomical conferences held in México and Latin America. Since 1995 a Series devoted exclusively to such proceedings was founded, RMxAC, Revista Mexicana de Astronomía y Astrofísica (Serie de Conferencias). All papers submitted to RMxAA are sent to internationally recognized experts to be strictly refereed. RMxAA is included in Current Contents, Science Citation Index and other relevant international indexes. Both publications are fully integrated into the ADS. Their contents have always been freely available to the general public. All this ensures a wide international visibility, comparable to that of the best astronomical journals. The impact factor of RMxAA has varied over the years, mostly as a consequence of small number statistics. The average impact factor is about 2.4, far larger than that of all but a few Latin American scientific journals. The editorial independence of RMxAA, the fact that there are no page charges for authors, and that the printed version is distributed free of charge to astronomical libraries all over the world motivate us to look forward with optimism to many more years of publication. In view of recent developments in the scientific publishing field, we have applied to obtain the DOI for the published papers, and are in the process of becoming an all-electronic publication.

  13. Characterization of two methylenedioxy bridge-forming cytochrome P450-dependent enzymes of alkaloid formation in the Mexican prickly poppy Argemone mexicana.

    PubMed

    Díaz Chávez, Maria Luisa; Rolf, Megan; Gesell, Andreas; Kutchan, Toni M

    2011-03-01

    Formation of the methylenedioxy bridge is an integral step in the biosynthesis of benzo[c]phenanthridine and protoberberine alkaloids in the Papaveraceae family of plants. This reaction in plants is catalyzed by cytochrome P450-dependent enzymes. Two cDNAs that encode cytochrome P450 enzymes belonging to the CYP719 family were identified upon interrogation of an EST dataset prepared from 2-month-old plantlets of the Mexican prickly poppy Argemone mexicana that accumulated the benzo[c]phenanthridine alkaloid sanguinarine and the protoberberine alkaloid berberine. CYP719A13 and CYP719A14 are 58% identical to each other and 77% and 60% identical, respectively, to stylopine synthase CYP719A2 of benzo[c]phenanthridine biosynthesis in Eschscholzia californica. Functional heterologous expression of CYP719A14 and CYP719A13 in Spodoptera frugiperda Sf9 cells produced recombinant enzymes that catalyzed the formation of the methylenedioxy bridge of (S)-cheilanthifoline from (S)-scoulerine and of (S)-stylopine from (S)-cheilanthifoline, respectively. Twenty-seven potential substrates were tested with each enzyme. Whereas CYP719A14 transformed only (S)-scoulerine to (S)-cheilanthifoline (K(m) 1.9±0.3; k(cat)/K(m) 1.7), CYP719A13 converted (S)-tetrahydrocolumbamine to (S)-canadine (K(m) 2.7±1.3; k(cat)/K(m) 12.8), (S)-cheilanthifoline to (S)-stylopine (K(m) 5.2±3.0; k(cat)/K(m) 2.6) and (S)-scoulerine to (S)-nandinine (K(m) 8.1±1.9; k(cat)/K(m) 0.7). These results indicate that although CYP719A14 participates in only sanguinarine biosynthesis, CYP719A13 can be involved in both sanguinarine and berberine formation in A. mexicana.

  14. Antinociceptive activity of Tilia americana var. mexicana inflorescences and quercetin in the formalin test and in an arthritic pain model in rats.

    PubMed

    Martínez, Ana Laura; González-Trujano, Ma Eva; Aguirre-Hernández, Eva; Moreno, Julia; Soto-Hernández, Marco; López-Muñoz, Francisco J

    2009-02-01

    Tilia species are well known around the world for their properties in traditional medicine. Antinociceptive activity of hexane, methanol and aqueous extracts from Tilia americana var. mexicana inflorescences was evaluated in the pain-induced functional impairment model in rats (PIFIR). A preliminar 300 mg/kg dosage of aqueous extracts i.p., but not the same dose of methanol or hexane extract, produced an antinociceptive response in rats similar to that of tramadol (17.8 mg/kg i.p.). A dose-response curve from aqueous extract allowed the determination of ED(50) = 364.97 mg/kg in comparison to ED(50) = 10.35 mg/kg for tramadol in this model. A previous HPLC-DAD analysis corroborated by an HPLC-MS technique in this study demonstrated the flavonoid composition in this Tilia aqueous extract revealing the presence of glycosides mainly derived from quercetin. Thus, Tilia aqueous extract and quercetin were tested at 30 and/or 100 mg/kg dosages i.p. in the PIFIR and formalin models producing a significant and dose-dependent antinociceptive response resembling that produced by a total and a partial agonist of 5-HT(1A) receptors like 8-OH-DPAT (0.1 mg/kg, s.c.) and buspirone (5 mg/kg, i.p.), respectively. In all the treatments, antinociceptive response was inhibited in the presence of WAY 100635 (0.12 mg/kg, i.p.). Our results support the analgesic activity of T. americana var. mexicana inflorescences attributed by folk medicine; they also indicate that quercetin is partly responsible for this pharmacological activity that is likely mediated by serotonin 5-HT(1A) receptors.

  15. Bioactivity-guided isolation of beta-sitosterol and some fatty acids as active compounds in the anxiolytic and sedative effects of Tilia americana var. mexicana.

    PubMed

    Aguirre-Hernández, Eva; Rosas-Acevedo, Hortensia; Soto-Hernández, Marcos; Martínez, Ana Laura; Moreno, Julia; González-Trujano, Ma Eva

    2007-09-01

    Tilia species have been used as anxiolytics for many years. In a previous study anxiolytic-like effects of a hexane extract of Tilia americana var. mexicana inflorescences were observed in experimental models in mice. To get additional insights into the neuroactive actions of this particular Tilia species, in this study we report a bioactivity guided-fractionation of the extract and separation by column chromatographic methods to isolate three fatty acids and a triterpene identified as beta-sitosterol as major constituents. Our results revealed that the crude extract at 10 and 30 mg/kg I. P. and some pooled fractions at the same dosages potentiated sodium pentobarbital-induced sleeping time and caused a significant increase in the time spent at the open-arm sides in the plus-maze test. A reduction in the exploratory behavioral pattern manifested as ambulatory activity, as well as head dipping and rearing tests was also observed. Further fractionation and purification yielded four major fractions containing fatty acids and beta-sitosterol as the active compounds. A dose-response curve of beta-sitosterol in the range 1 to 30 mg/kg doses indicated that this compound produced an anxiolytic-like action from 1 to 10 mg/kg and a sedative response when the dose was increased to 30 mg/kg, these effects resemble those produced by diazepam (0.1 mg/kg). Our results suggest that hexane extract of Tilia americana var. mexicana produces depressant actions on the central nervous system, at least in part, because of the presence of beta-sitosterol and some fatty acids that remain to be identified.

  16. Different susceptibilities of Leishmania spp. promastigotes to the Annona muricata acetogenins annonacinone and corossolone, and the Platymiscium floribundum coumarin scoparone.

    PubMed

    Vila-Nova, Nadja Soares; de Morais, Selene Maia; Falcão, Maria José Cajazeiras; Alcantara, Terezinha Thaize Negreiros; Ferreira, Pablito Augusto Travassos; Cavalcanti, Eveline Solon Barreira; Vieira, Icaro Gusmão Pinto; Campello, Cláudio Cabral; Wilson, Mary

    2013-03-01

    Leishmaniasis is a zoonotic disease that can manifest itself in visceral and cutaneous form. The aim of this study was to search for new leishmanicidal compounds. Preliminarily, Artemia salina assay was applied to compounds from two plants found in Northeastern Brazil, Platymiscium floribundum and Annona muricata. Then these compounds were tested against three Leishmania species (Leishmania donovani, Leishmania mexicana and Leishmania major). A screening assay using luciferase-expressing promastigote form were used to measure the viability of promastigote One coumarin, scoparone, isolated from P. floribundum and two acetogenins, annonacinone and corossolone isolated from A. muricata showed leishmanicidal activity in all species tested. Nevertheless, Leishmania species indicated different susceptibilities in relation to the tested compounds: L. mexicana was more sensitive to scoparone followed by L. major and L. donovani. The three species presented similar inhibition to corossolone and annonacinone. Acetogenin annonacinone (EC(50)=6.72-8.00 μg/mL) indicated high leishmanicidal activity; corossolone (EC(50)=16.14-18.73 μg/mL) and scoparone (EC(50)=9.11-27.51 μg/mL) moderate activity. A. saline larvae were less sensitive to the coumarin scoparone and acetogenin corossolone was the most toxic. In conclusion, the leishmanicidal activity demonstrated by the coumarin and acetogenins indicate these compounds for further studies aiming the development of new leishmanicidal agents. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Down-Regulation of TLR and JAK/STAT Pathway Genes Is Associated with Diffuse Cutaneous Leishmaniasis: A Gene Expression Analysis in NK Cells from Patients Infected with Leishmania mexicana

    PubMed Central

    Castillo-Fernández, Juan E.; Miranda-Ortíz, Haydee; Fernández-López, Juan C.; Becker, Ingeborg; Rangel-Escareño, Claudia

    2016-01-01

    An important NK-cell inhibition with reduced TNF-α, IFN-γ and TLR2 expression had previously been identified in patients with diffuse cutaneous leishmaniasis (DCL) infected with Leishmania mexicana. In an attempt to pinpoint alterations in the signaling pathways responsible for the NK-cell dysfunction in patients with DCL, this study aimed at identifying differences in the NK-cell response towards Leishmania mexicana lipophosphoglycan (LPG) between patients with localized and diffuse cutaneous leishmaniasis through gene expression profiling. Our results indicate that important genes involved in the innate immune response to Leishmania are down-regulated in NK cells from DCL patients, particularly TLR and JAK/STAT signaling pathways. This down-regulation showed to be independent of LPG stimulation. The study sheds new light for understanding the mechanisms that undermine the correct effector functions of NK cells in patients with diffuse cutaneous leishmaniasis contributing to a better understanding of the pathobiology of leishmaniasis. PMID:27031998

  18. Comparative assessment of a DNA and protein Leishmania donovani gamma glutamyl cysteine synthetase vaccine to cross-protect against murine cutaneous leishmaniasis caused by L. major or L. mexicana infection.

    PubMed

    Campbell, S A; Alawa, J; Doro, B; Henriquez, F L; Roberts, C W; Nok, A; Alawa, C B I; Alsaadi, M; Mullen, A B; Carter, K C

    2012-02-08

    Leishmaniasis is a major health problem and it is estimated that 12 million people are currently infected. A vaccine which could cross-protect people against different Leishmania spp. would facilitate control of this disease as more than one species of Leishmania may be present. In this study the ability of a DNA vaccine, using the full gene sequence for L. donovani gamma glutamyl cysteine synthetase (γGCS) incorporated in the pVAX vector (pVAXγGCS), and a protein vaccine, using the corresponding recombinant L. donovani γGCS protein (LdγGCS), to protect against L. major or L. mexicana infection was evaluated. DNA vaccination gave transient protection against L. major and no protection against L. mexicana despite significantly enhancing specific antibody titres in vaccinated infected mice compared to infected controls. Vaccination with the LdγGCS protected against both species but only if the protein was incorporated into non-ionic surfactant vesicles for L. mexicana. The results of this study indicate that a L. donovani γGCS vaccine could be used to vaccinate against more than one Leishmania species but only if the recombinant protein is used.

  19. Ecology of phlebotomine sandflies and putative reservoir hosts of leishmaniasis in a border area in Northeastern Mexico: implications for the risk of transmission of Leishmania mexicana in Mexico and the USA.

    PubMed

    Rodríguez-Rojas, Jorge J; Rodríguez-Moreno, Ángel; Berzunza-Cruz, Miriam; Gutiérrez-Granados, Gabriel; Becker, Ingeborg; Sánchez-Cordero, Victor; Stephens, Christopher R; Fernández-Salas, Ildefonso; Rebollar-Téllez, Eduardo A

    2017-01-01

    Leishmaniases are a group of important diseases transmitted to humans through the bite of sandfly vectors. Several forms of leishmaniases are endemic in Mexico and especially in the Southeast region. In the Northeastern region, however, there have only been isolated reports of cases and scanty records of sandfly vectors. The main objective of this study was to analyze the diversity of sandflies and potential reservoir hosts of Leishmania spp. in the states of Nuevo León and Tamaulipas. Species richness and abundances of sandflies and rodents were recorded. A fraction of the caught sandflies was analyzed by PCR to detect Leishmania spp. Tissues from captured rodents were also screened for infection. Ecological Niche Models (ENMs) were computed for species of rodent and their association with crop-growing areas. We found 13 species of sandflies, several of which are first records for this region. Medically important species such as Lutzomyia anthophora, Lutzomyia diabolica, Lutzomyia cruciata, and Lutzomyia shannoni were documented. Leishmania spp. infection was not detected in sandflies. Nine species of rodents were recorded, and Leishmania (Leishmania) mexicana infection was found in four species of Peromyscus and Sigmodon. ENMs showed that potential distribution of rodent pest species overlaps with allocated crop areas. This shows that Leishmania (L.) mexicana infection is present in the Northeastern region of Mexico, and that previously unrecorded sandfly species occur in the same areas. These findings suggest a potential risk of transmission of Leishmania (L.) mexicana. © J. Rodríguez-Rojas et al., published by EDP Sciences, 2017.

  20. Ecology of phlebotomine sandflies and putative reservoir hosts of leishmaniasis in a border area in Northeastern Mexico: implications for the risk of transmission of Leishmania mexicana in Mexico and the USA

    PubMed Central

    Rodríguez-Rojas, Jorge J.; Rodríguez-Moreno, Ángel; Berzunza-Cruz, Miriam; Gutiérrez-Granados, Gabriel; Becker, Ingeborg; Sánchez-Cordero, Victor; Stephens, Christopher R.; Fernández-Salas, Ildefonso; Rebollar-Téllez, Eduardo A.

    2017-01-01

    Leishmaniases are a group of important diseases transmitted to humans through the bite of sandfly vectors. Several forms of leishmaniases are endemic in Mexico and especially in the Southeast region. In the Northeastern region, however, there have only been isolated reports of cases and scanty records of sandfly vectors. The main objective of this study was to analyze the diversity of sandflies and potential reservoir hosts of Leishmania spp. in the states of Nuevo León and Tamaulipas. Species richness and abundances of sandflies and rodents were recorded. A fraction of the caught sandflies was analyzed by PCR to detect Leishmania spp. Tissues from captured rodents were also screened for infection. Ecological Niche Models (ENMs) were computed for species of rodent and their association with crop-growing areas. We found 13 species of sandflies, several of which are first records for this region. Medically important species such as Lutzomyia anthophora, Lutzomyia diabolica, Lutzomyia cruciata, and Lutzomyia shannoni were documented. Leishmania spp. infection was not detected in sandflies. Nine species of rodents were recorded, and Leishmania (Leishmania) mexicana infection was found in four species of Peromyscus and Sigmodon. ENMs showed that potential distribution of rodent pest species overlaps with allocated crop areas. This shows that Leishmania (L.) mexicana infection is present in the Northeastern region of Mexico, and that previously unrecorded sandfly species occur in the same areas. These findings suggest a potential risk of transmission of Leishmania (L.) mexicana. PMID:28825400

  1. Application of hydrostatic CCC-TLC-HPLC-ESI-TOF-MS for the bioguided fractionation of anticholinesterase alkaloids from Argemone mexicana L. roots.

    PubMed

    Kukula-Koch, Wirginia; Mroczek, Tomasz

    2015-03-01

    A rapid hydrostatic counter-current chromatography-thin-layer chromatography-electrospray-ionization time-of-flight mass spectrometry (CCC-TLC-ESI-TOF-MS) technique was established for use in seeking potent anti-Alzheimer's drugs among the acethylcholinesterase inhibitors in Argemone mexicana L. underground parts, with no need to isolate components in pure form. The dichloromethane extract from the roots of Mexican prickly poppy that was most rich in secondary metabolites was subjected to hydrostatic-CCC-based fractionation in descending mode, using a biphasic system composed of petroleum ether-ethyl acetate-methanol-water at the ratio of 1.5:3:2.1:2 (v/v). The obtained fractions were analyzed in a TLC-based AChE-inhibition "Fast Blue B" test. All active components in the fractions, including berberine, protopine, chelerithrine, sanguinarine, coptisine, palmatine, magnoflorine, and galanthamine, were identified in a direct TLC-HPLC-ESI-TOF-MS assay with high accuracy. This is the first time galanthamine has been reported in the extract of Mexican prickly poppy and the first time it has been identified in any member of the Papaveraceae family, in the significant quantity of 0.77%.

  2. In vitro assessment of Argemone mexicana, Taraxacum officinale, Ruta chalepensis and Tagetes filifolia against Haemonchus contortus nematode eggs and infective (L3) larvae.

    PubMed

    Jasso Díaz, Gabriela; Hernández, Glafiro Torres; Zamilpa, Alejandro; Becerril Pérez, Carlos Miguel; Ramírez Bribiesca, J Efrén; Hernández Mendo, Omar; Sánchez Arroyo, Hussein; González Cortazar, Manasés; Mendoza de Gives, Pedro

    2017-08-01

    Argemone mexicana, Taraxacum officinale, Ruta chalepensis and Tagetes filifolia are plants with deworming potential. The purpose of this study was to evaluate methanolic extracts of aerial parts of these plants against Haemonchus contortus eggs and infective larvae (L3) and identify compounds responsible for the anthelmintic activity. In vitro probes were performed to identify the anthelmintic activity of plant extracts: egg hatching inhibition (EHI) and larvae mortality. Open column Chromatography was used to bio-guided fractionation of the extract, which shows the best anthelmintic effect. The lethal concentration to inhibit 50% of H. contortus egg hatching or larvae mortality (LC50) was calculated using a Probit analysis. Bio-guided procedure led to the recognition of an active fraction (TF11) mainly composed by 1) quercetagitrin, 2) methyl chlorogenate and chlorogenic acid. Quercetagitrin (1) and methyl chlorogenate (2) did not show an important EHI activity (3-14%) (p < 0.05); however, chlorogenic acid (3) showed 100% of EHI (LC50 248 μg/mL) (p < 0.05). Chlorogenic acid is responsible of the ovicidal activity and it seems that, this compound is reported for the first time with anthelmintic activity against a parasite of importance in sheep industry. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Gradient Evolution of Body Colouration in Surface- and Cave-Dwelling Poecilia mexicana and the Role of Phenotype-Assortative Female Mate Choice

    PubMed Central

    Penshorn, Marina; Hamfler, Sybille; Herbert, Denise B.; Appel, Jessica; Meyer, Philipp; Slattery, Patrick; Charaf, Sarah; Wolf, Raoul; Völker, Johannes; Berger, Elisabeth A. M.; Dröge, Janis; Riesch, Rüdiger; Arias-Rodriguez, Lenin; Indy, Jeanne R.; Plath, Martin

    2013-01-01

    Ecological speciation assumes reproductive isolation to be the product of ecologically based divergent selection. Beside natural selection, sexual selection via phenotype-assortative mating is thought to promote reproductive isolation. Using the neotropical fish Poecilia mexicana from a system that has been described to undergo incipient ecological speciation in adjacent, but ecologically divergent habitats characterized by the presence or absence of toxic H2S and darkness in cave habitats, we demonstrate a gradual change in male body colouration along the gradient of light/darkness, including a reduction of ornaments that are under both inter- and intrasexual selection in surface populations. In dichotomous choice tests using video-animated stimuli, we found surface females to prefer males from their own population over the cave phenotype. However, female cave fish, observed on site via infrared techniques, preferred to associate with surface males rather than size-matched cave males, likely reflecting the female preference for better-nourished (in this case: surface) males. Hence, divergent selection on body colouration indeed translates into phenotype-assortative mating in the surface ecotype, by selecting against potential migrant males. Female cave fish, by contrast, do not have a preference for the resident male phenotype, identifying natural selection against migrants imposed by the cave environment as the major driver of the observed reproductive isolation. PMID:24175282

  4. Crystal structures of Leishmania mexicana arginase complexed with α,α-disubstituted boronic amino-acid inhibitors

    SciTech Connect

    Hai, Yang; Christianson, David W.

    2016-03-16

    Leishmaniaarginase is a potential drug target for the treatment of leishmaniasis because this binuclear manganese metalloenzyme initiatesde novopolyamine biosynthesis by catalyzing the hydrolysis of L-arginine to generate L-ornithine and urea. The product L-ornithine subsequently undergoes decarboxylation to yield putrescine, which in turn is utilized for spermidine biosynthesis. Polyamines such as spermidine are essential for the growth and survival of the parasite, so inhibition of enzymes in the polyamine-biosynthetic pathway comprises an effective strategy for treating parasitic infections. To this end, two X-ray crystal structures ofL. mexicanaarginase complexed with α,α-disubstituted boronic amino-acid inhibitors based on the molecular scaffold of 2-(S)-amino-6-boronohexanoic acid are now reported. Structural comparisons with human and parasitic arginase complexes reveal interesting differences in the binding modes of the additional α-substituents,i.e.the D side chains, of these inhibitors. Subtle differences in the three-dimensional contours of the outer active-site rims among arginases from different species lead to different conformations of the D side chains and thus different inhibitor-affinity trends. The structures suggest that it is possible to maintain affinity while fine-tuning intermolecular interactions of the D side chain of α,α-disubstituted boronic amino-acid inhibitors in the search for isozyme-specific and species-specific arginase inhibitors.

  5. Genetic structure and divergence in populations of Lutzomyia cruciata, a phlebotomine sand fly (Diptera: Psychodidae) vector of Leishmania mexicana in southeastern Mexico.

    PubMed

    Pech-May, Angélica; Marina, Carlos F; Vázquez-Domínguez, Ella; Berzunza-Cruz, Miriam; Rebollar-Téllez, Eduardo A; Narváez-Zapata, José A; Moo-Llanes, David; Ibáñez-Bernal, Sergio; Ramsey, Janine M; Becker, Ingeborg

    2013-06-01

    The low dispersal capacity of sand flies could lead to population isolation due to geographic barriers, climate variation, or to population fragmentation associated with specific local habitats due to landscape modification. The phlebotomine sand fly Lutzomyia cruciata has a wide distribution throughout Mexico and is a vector of Leishmania mexicana in the southeast. The aim of this study was to evaluate the genetic diversity, structure, and divergence within and among populations of Lu. cruciata in the state of Chiapas, and to infer the intra-specific phylogeny using the 3' end of the mitochondrial cytochrome b gene. We analyzed 62 sequences from four Lu. cruciata populations and found 26 haplotypes, high genetic differentiation and restricted gene flow among populations (Fst=0.416, Nm=0.701, p<0.001). The highest diversity values were recorded in populations from Loma Bonita and Guadalupe Miramar. Three lineages (100% bootstrap and 7% overall divergence) were identified using a maximum likelihood phylogenetic analysis which showed high genetic divergence (17.2-22.7%). A minimum spanning haplotype network also supported separation into three lineages. Genetic structure and divergence within and among Lu. cruciata populations are hence affected by geographic heterogeneity and evolutionary background. Data obtained in the present study suggest that Lu. cruciata in the state of Chiapas consists of at least three lineages. Such findings may have implications for vector capacity and hence for vector control strategies.

  6. Gradient evolution of body colouration in surface- and cave-dwelling Poecilia mexicana and the role of phenotype-assortative female mate choice.

    PubMed

    Bierbach, David; Penshorn, Marina; Hamfler, Sybille; Herbert, Denise B; Appel, Jessica; Meyer, Philipp; Slattery, Patrick; Charaf, Sarah; Wolf, Raoul; Völker, Johannes; Berger, Elisabeth A M; Dröge, Janis; Wolf, Konstantin; Riesch, Rüdiger; Arias-Rodriguez, Lenin; Indy, Jeanne R; Plath, Martin

    2013-01-01

    Ecological speciation assumes reproductive isolation to be the product of ecologically based divergent selection. Beside natural selection, sexual selection via phenotype-assortative mating is thought to promote reproductive isolation. Using the neotropical fish Poecilia mexicana from a system that has been described to undergo incipient ecological speciation in adjacent, but ecologically divergent habitats characterized by the presence or absence of toxic H2S and darkness in cave habitats, we demonstrate a gradual change in male body colouration along the gradient of light/darkness, including a reduction of ornaments that are under both inter- and intrasexual selection in surface populations. In dichotomous choice tests using video-animated stimuli, we found surface females to prefer males from their own population over the cave phenotype. However, female cave fish, observed on site via infrared techniques, preferred to associate with surface males rather than size-matched cave males, likely reflecting the female preference for better-nourished (in this case: surface) males. Hence, divergent selection on body colouration indeed translates into phenotype-assortative mating in the surface ecotype, by selecting against potential migrant males. Female cave fish, by contrast, do not have a preference for the resident male phenotype, identifying natural selection against migrants imposed by the cave environment as the major driver of the observed reproductive isolation.

  7. Heterologous expression of two FAD-dependent oxidases with (S)-tetrahydroprotoberberine oxidase activity from Arge mone mexicana and Berberis wilsoniae in insect cells.

    PubMed

    Gesell, Andreas; Chávez, Maria Luisa Díaz; Kramell, Robert; Piotrowski, Markus; Macheroux, Peter; Kutchan, Toni M

    2011-06-01

    Berberine, palmatine and dehydrocoreximine are end products of protoberberine biosynthesis. These quaternary protoberberines are elicitor inducible and, like other phytoalexins, are highly oxidized. The oxidative potential of these compounds is derived from a diverse array of biosynthetic steps involving hydroxylation, intra-molecular C-C coupling, methylenedioxy bridge formation and a dehydrogenation reaction as the final step in the biosynthesis. For the berberine biosynthetic pathway, the identification of the dehydrogenase gene is the last remaining uncharacterized step in the elucidation of the biosynthesis at the gene level. An enzyme able to catalyze these reactions, (S)-tetrahydroprotoberberine oxidase (STOX, EC 1.3.3.8), was originally purified in the 1980s from suspension cells of Berberis wilsoniae and identified as a flavoprotein (Amann et al. 1984). We report enzymatic activity from recombinant STOX expressed in Spodoptera frugiperda Sf9 insect cells. The coding sequence was derived successively from peptide sequences of purified STOX protein. Furthermore, a recombinant oxidase with protoberberine dehydrogenase activity was obtained from a cDNA library of Argemone mexicana, a traditional medicinal plant that contains protoberberine alkaloids. The relationship of the two enzymes is discussed regarding their enzymatic activity, phylogeny and the alkaloid occurrence in the plants. Potential substrate binding and STOX-specific amino acid residues were identified based on sequence analysis and homology modeling.

  8. Traditional nutritional analyses of figs overestimates intake of most nutrient fractions: a study of ficus perforata consumed by howler monkeys (Alouatta palliata mexicana).

    PubMed

    Urquiza-Haas, Tania; Serio-Silva, Juan Carlos; Hernández-Salazar, Laura Teresa

    2008-05-01

    There continue to remain uncertainty concerning the nutritional importance of figs (Ficus spp.) in the primate diet. Although studies have been performed on the nutritional analysis of fig pulp and seed fractions separately, there has not been an attempt to quantify the contribution of animal matter within figs. Here we report nutritional values of figs (Ficus perforata) (Urostigma) consumed by a troop of howler monkeys (Alouatta palliata mexicana). Separate nutritional assays were performed on the pulp, seed, and animal fraction. Whole-fig analyses significantly exaggerate the concentrations of all nutrients (lipids especially) as seeds, which represent a large proportion of the fig (45%), cannot be digested. Animal matter only represents 1% of the fig, and augments fig protein and lipid content by 0.44 and 0.30%, respectively. This represents the 11 and 9% of the fraction available for digestion. Differences in fig consumption were observed between age and sex classes (P=0.04) and periods of the day (P=0.001); females consumed more figs than males and the highest consumption of figs was observed in the afternoon. F. perforata figs may be an important component of the howler monkeys diet owing to their high content of water and calcium.

  9. Texture and nano-scale internal microstructure of otoliths in the Atlantic molly, Poecilia mexicana: a high-resolution EBSD study.

    PubMed

    Schulz-Mirbach, T; Götz, A; Griesshaber, E; Plath, M; Schmahl, W W

    2013-08-01

    Otoliths of modern bony fishes are massive polycrystalline structures consisting mainly of calcium carbonate (primarily aragonite), and 1-10% organic residuals. Unlike other biomineralisates like shells, teeth and bones, they are not optimized for mechanical loads but serve the senses of hearing and balance in the inner ear. We examined internal structural variation of otoliths through microstructural and texture analyses. Our study applied the electron backscattered diffraction technique (EBSD) to whole sections of saccular otoliths on cave- and surface-dwelling fish. Application of high spatial resolution EBSD on otoliths of the livebearing fish Poecilia mexicana allowed for an investigation of crystal orientation despite the small size (<150 nm) of aragonite crystallites. Crystallites at the rims of otoliths had a higher structural organization than those situated near the center, where no dominant orientation pattern was discernible. Moreover, the medial (sulcal) face of otoliths, which makes contact with the sensory epithelium, was more structured than the lateral (antisulcal) face. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Taxonomic and nomenclatorial revision within the Neotropical genera of the subtribe Odontocheilina W. Horn in a new sense-18. Six Mexican and Central American species related to Odontocheila mexicana Laporte de Castelnau and O. ignita Chaudoir, with a description of O. potosiana sp. nov. (Coleoptera: Cicindelidae).

    PubMed

    Moravec, Jiří; Brzoska, David; Huber, Ronald

    2017-02-13

    Results of taxonomic revision of Mexican and Central American species of the genus Odontocheila Laporte de Castelnau, 1834, related to Odontocheila mexicana Laporte de Castelnau, 1834 (rectified publication date) and O. ignita Chaudoir, 1860 are presented. Redescriptions of O. mexicana, O. iodopleura Bates, 1872 and O. exilis Bates, 1884 are provided with their lectotype designations, and redescriptions of O. tawahka Johnson, 1996 and O. ignita are presented. O. exilis is restored to its original species status. Lectotype designations of O. cinctula Bates, 1881 and O. quadrina (based on Cicindela quadrina Chevrolat, 1835) are provided. The synonymy of O. cinctula with O. ignita is confirmed, as well as the synonymy of O. quadrina with O. mexicana. O. potosiana sp. nov. is described from Mexico as new for science; it represents the northernmost occurrence of the genus. A key to these related species is presented and their biology and distribution is treated. Illustrations in colour photographs of the habitus, diagnostic characters and variability are provided.

  11. Molecular Diversity between Salivary Proteins from New World and Old World Sand Flies with Emphasis on Bichromomyia olmeca, the Sand Fly Vector of Leishmania mexicana in Mesoamerica

    PubMed Central

    Townsend, Shannon; Pasos-Pinto, Silvia; Sanchez, Laura; Rasouli, Manoochehr; B. Guimaraes-Costa, Anderson; Aslan, Hamide; Francischetti, Ivo M. B.; Oliveira, Fabiano; Becker, Ingeborg; Kamhawi, Shaden; Ribeiro, Jose M. C.; Jochim, Ryan C.; Valenzuela, Jesus G.

    2016-01-01

    Background Sand fly saliva has been shown to have proteins with potent biological activities, salivary proteins that can be used as biomarkers of vector exposure, and salivary proteins that are candidate vaccines against different forms of leishmaniasis. Sand fly salivary gland transcriptomic approach has contributed significantly to the identification and characterization of many of these salivary proteins from important Leishmania vectors; however, sand fly vectors in some regions of the world are still neglected, as Bichromomyia olmeca (formerly known as Lutzomyia olmeca olmeca), a proven vector of Leishmania mexicana in Mexico and Central America. Despite the importance of this vector in transmitting Leishmania parasite in Mesoamerica there is no information on the repertoire of B. olmeca salivary proteins and their relationship to salivary proteins from other sand fly species. Methods and Findings A cDNA library of the salivary glands of wild-caught B. olmeca was constructed, sequenced, and analyzed. We identified transcripts encoding for novel salivary proteins from this sand fly species and performed a comparative analysis between B. olmeca salivary proteins and those from other sand fly species. With this new information we present an updated catalog of the salivary proteins specific to New World sand flies and salivary proteins common to all sand fly species. We also report in this work the anti-Factor Xa activity of Lofaxin, a salivary anticoagulant protein present in this sand fly species. Conclusions This study provides information on the first transcriptome of a sand fly from Mesoamerica and adds information to the limited repertoire of salivary transcriptomes from the Americas. This comparative analysis also shows a fast degree of evolution in salivary proteins from New World sand flies as compared with Old World sand flies. PMID:27409591

  12. 2'-Deoxyribosyltransferase from Leishmania mexicana, an efficient biocatalyst for one-pot, one-step synthesis of nucleosides from poorly soluble purine bases.

    PubMed

    Crespo, N; Sánchez-Murcia, P A; Gago, F; Cejudo-Sanches, J; Galmes, M A; Fernández-Lucas, Jesús; Mancheño, José Miguel

    2017-08-07

    Processes catalyzed by enzymes offer numerous advantages over chemical methods although in many occasions the stability of the biocatalysts becomes a serious concern. Traditionally, synthesis of nucleosides using poorly water-soluble purine bases, such as guanine, xanthine, or hypoxanthine, requires alkaline pH and/or high temperatures in order to solubilize the substrate. In this work, we demonstrate that the 2'-deoxyribosyltransferase from Leishmania mexicana (LmPDT) exhibits an unusually high activity and stability under alkaline conditions (pH 8-10) across a broad range of temperatures (30-70 °C) and ionic strengths (0-500 mM NaCl). Conversely, analysis of the crystal structure of LmPDT together with comparisons with hexameric, bacterial homologues revealed the importance of the relationships between the oligomeric state and the active site architecture within this family of enzymes. Moreover, molecular dynamics and docking approaches provided structural insights into the substrate-binding mode. Biochemical characterization of LmPDT identifies the enzyme as a type I NDT (PDT), exhibiting excellent activity, with specific activity values 100- and 4000-fold higher than the ones reported for other PDTs. Interestingly, LmPDT remained stable during 36 h at different pH values at 40 °C. In order to explore the potential of LmPDT as an industrial biocatalyst, enzymatic production of several natural and non-natural therapeutic nucleosides, such as vidarabine (ara A), didanosine (ddI), ddG, or 2'-fluoro-2'-deoxyguanosine, was carried out using poorly water-soluble purines. Noteworthy, this is the first time that the enzymatic synthesis of 2'-fluoro-2'-deoxyguanosine, ara G, and ara H by a 2'-deoxyribosyltransferase is reported.

  13. Polycyclic aromatic hydrocarbons in urban tunnels of Guanajuato city (Mexico) measured in deposited dust particles and in transplanted lichen Xanthoparmelia mexicana (Gyeln.) Hale.

    PubMed

    Puy-Alquiza, María Jesús; Reyes, Veridiana; Wrobel, Katarzyna; Wrobel, Kazimierz; Torres Elguera, Julio César; Miranda-Aviles, Raúl

    2016-06-01

    Sixteen priority PAHs were determined in five urban tunnels of Guanajuato city, through which about 4 % of population walks and about 25,000 vehicles pass daily. Xanthoparmelia mexicana (Gyeln.) Hale, highly abundant lichen in this region, was exposed during 6 months and then the samples were collected together with the wall dust; both materials were analyzed by gas chromatography-mass spectrometry. Total PAH concentrations in dust and in lichen samples were in the range 1392-7961 ng g(-1) (average per tunnel 4637 ng g(-1)) and 522-3571 ng g(-1) (average 2587 ng g(-1)), respectively. In dust, the highest concentrations corresponded to PYR, FLA, BaA, CHR, BaP, and PHE, whereas in lichens the most abundant were DahA, IcdP, BghiP, and PYR. The obtained results suggested passive deposition of PAHs on lipophilic lichen surface rather than phenomena associated with metabolic activity of the exposed organisms. Application of seven different molecular diagnostic ratios pointed to gasoline-operated cars as the principal source of PAHs. Based on the obtained results and their comparison with data reported for other geographical regions, Guanajuato tunnels were considered moderately contaminated with PAHs; however toxic BaP equivalent concentrations integrated for seven carcinogenic compounds presented relatively high values in four tunnels: 567-1051 ngBaPeq g(-1) as evaluated for dust samples. Since up to 7000 persons walk daily through tunnels, the obtained data call for more detailed study evaluating PAHs toxicity in Guanajuato population.

  14. NK Cell Activity Differs between Patients with Localized and Diffuse Cutaneous Leishmaniasis Infected with Leishmania mexicana: A Comparative Study of TLRs and Cytokines

    PubMed Central

    Cañeda-Guzmán, Isabel Cristina; Salaiza-Suazo, Norma; Fernández-Figueroa, Edith A.; Carrada-Figueroa, Georgina; Aguirre-García, Magdalena; Becker, Ingeborg

    2014-01-01

    Leishmania mexicana causes localized (LCL) or diffuse cutaneous leishmaniasis (DCL). The cause of dissemination in DCL remains unknown, yet NK cells possibly play a role in activating leishmanicidal mechanisms during innate and adaptive immune responses. We had previously shown that Leishmania lipophosphoglycan (LPG) is a ligand for TLR2, activating human NK cells. We have now analyzed NK cells in LCL and DCL patients. NK numbers and effector mechanisms differed drastically between both groups of patients: DCL patients showed reduced NK cell numbers; diminished IFN-γ and TNF-α production; and lower TLR2, TLR1, and TLR6 expression as compared to LCL patients. The altered protein expression found in NK cells of DCL patients correlated with their down-regulation of IFN-γ gene expression in LPG-stimulated and non-stimulated cells as compared to LCL patients. NK cell response was further analyzed according to gender, age, and disease evolution in LCL patients showing that female patients produced higher IFN-γ levels throughout the disease progression, whereas TLR2 expression diminished in both genders with prolonged disease evolution and age. We furthermore show the activation pathway of LPG binding to TLR2 and demonstrated that TLR2 forms immunocomplexes with TLR1 and TLR6. In addition to the reduced NK cell numbers in peripheral blood, DCL patients also showed reduced NK cell numbers in the lesions. They were randomly scattered within the lesions, showing diminished cytokine production, which contrasts with those of LCL lesions, where NK cells produced IFN-γ and TNF-α and were found within organized granulomas. We conclude that in DCL patients the reduced NK-cell numbers and their diminished activity, evidenced by low TLR expression and low cytokine production, are possibly involved in the severity of the disease. Our results provide new information on the contribution of NK cells in Leishmania infections of the human host. PMID:25397678

  15. Quantity over quality: light intensity, but not red/far-red ratio, affects extrafloral nectar production in Senna mexicana var. chapmanii.

    PubMed

    Jones, Ian M; Koptur, Suzanne

    2015-09-01

    Extrafloral nectar (EFN) mediates food-for-protection mutualisms between plants and insects and provides plants with a form of indirect defense against herbivory. Understanding sources of variation in EFN production is important because such variations affect the number and identity of insect visitors and the effectiveness of plant defense. Light represents a potentially crucial tool for regulating resource allocation to defense, as it not only contributes energy but may help plants to anticipate future conditions. Low red/far-red (R/FR) light ratios can act as a signal of the proximity of competing plants. Exposure to such light ratios has been shown to promote competitive behaviors that coincide with reduced resource allocation to direct chemical defenses. Little is known, however, about how such informational light signals might affect indirect defenses such as EFN, and the interactions that they mediate. Through controlled glasshouse experiments, we investigated the effects of light intensity, and R/FR light ratios, on EFN production in Senna mexicana var. chapmanii. Plants in light-limited conditions produced significantly less EFN, and leaf damage elicited increased EFN production regardless of light conditions. Ratios of R/FR light, however, did not appear to affect EFN production in either damaged or undamaged plants. Understanding the effects of light on indirect defenses is of particular importance for plants in the threatened pine rockland habitats of south Florida, where light conditions are changing in predictable ways following extensive fragmentation and subsequent mismanagement. Around 27% of species in these habitats produce EFN and may rely on insect communities for defense.

  16. Molecular Diversity between Salivary Proteins from New World and Old World Sand Flies with Emphasis on Bichromomyia olmeca, the Sand Fly Vector of Leishmania mexicana in Mesoamerica.

    PubMed

    Abdeladhim, Maha; V Coutinho-Abreu, Iliano; Townsend, Shannon; Pasos-Pinto, Silvia; Sanchez, Laura; Rasouli, Manoochehr; B Guimaraes-Costa, Anderson; Aslan, Hamide; Francischetti, Ivo M B; Oliveira, Fabiano; Becker, Ingeborg; Kamhawi, Shaden; Ribeiro, Jose M C; Jochim, Ryan C; Valenzuela, Jesus G

    2016-07-01

    Sand fly saliva has been shown to have proteins with potent biological activities, salivary proteins that can be used as biomarkers of vector exposure, and salivary proteins that are candidate vaccines against different forms of leishmaniasis. Sand fly salivary gland transcriptomic approach has contributed significantly to the identification and characterization of many of these salivary proteins from important Leishmania vectors; however, sand fly vectors in some regions of the world are still neglected, as Bichromomyia olmeca (formerly known as Lutzomyia olmeca olmeca), a proven vector of Leishmania mexicana in Mexico and Central America. Despite the importance of this vector in transmitting Leishmania parasite in Mesoamerica there is no information on the repertoire of B. olmeca salivary proteins and their relationship to salivary proteins from other sand fly species. A cDNA library of the salivary glands of wild-caught B. olmeca was constructed, sequenced, and analyzed. We identified transcripts encoding for novel salivary proteins from this sand fly species and performed a comparative analysis between B. olmeca salivary proteins and those from other sand fly species. With this new information we present an updated catalog of the salivary proteins specific to New World sand flies and salivary proteins common to all sand fly species. We also report in this work the anti-Factor Xa activity of Lofaxin, a salivary anticoagulant protein present in this sand fly species. This study provides information on the first transcriptome of a sand fly from Mesoamerica and adds information to the limited repertoire of salivary transcriptomes from the Americas. This comparative analysis also shows a fast degree of evolution in salivary proteins from New World sand flies as compared with Old World sand flies.

  17. New neotropical species of Opiinae (Hymenoptera, Braconidae) reared from fruit-infesting and leaf-mining Tephritidae (Diptera) with comments on the  Diachasmimorpha mexicana species group and the genera Lorenzopius and Tubiformopius

    PubMed Central

    Wharton, Robert; Ward, Lauren; Miko, Istvan

    2012-01-01

    Abstract Four new species of opiine Braconidae are described from Mexico. These are Diachasmimorpha martinalujai Wharton reared from Rhagoletis infesting fruits of Crataegus spp., Diachasmimorpha norrbomi Wharton reared from Euphranta mexicana infesting fruits of Ribes pringlei, Eurytenes (Stigmatopoea) norrbomi Wharton reared from Trypeta concolor mining leaves of Barkleyanthus salicifolia and Eurytenes (Stigmatopoea) maya Wharton reared from Rhagoletis pomonella infesting apples and fruits of Crataegus spp. Morphological features of the first metasomal segment and occipital carina, useful for placement of these species, are discussed relative to the genera Diachasmimorpha, Eurytenes, Lorenzopius, Tubiformopius, and Opius s.l. Descriptions and diagnoses are referenced to the Hymenoptera Anatomy Ontology. The following represent new combinations: Diachasmimorpha hildagensis, Lorenzopius euryteniformis, and Tubiformopius tubibasis. Revised diagnoses are provided for Diachasmimorpha hildagensis, Diachasmimorpha mexicana, Diachasmimorpha sanguinea, Eurytenes (Stigmatopoea), Lorenzopius, Lorenzopius euryteniformis, Tubiformopius, Tubiformopius tubigaster, Tubiformopius tubibasis, Opius incoligma, and Opius rugicoxis. Two species groups are delineated within Lorenzopius and a key to species of Diachasmimorpha occurring in the New World is provided. PMID:23818811

  18. Field validation of a Leishmania (Leishmania) mexicana exo-antigens ELISA for diagnosing tegumentary leishmaniasis in regions of Leishmania (Viannia) predominance.

    PubMed

    Soares, Killarney Ataide; Urdapilleta, Ada Amália Ayala; Santos, Gilcilene Maria dos; Carneiro, Andréa Lisboa; Gomes, Ciro Martins; Roselino, Ana Maria; Sampaio, Raimunda Nonata Ribeiro

    2015-01-01

    Several tests are performed to obtain better accuracy when diagnosing American tegumentary leishmaniasis (ATL). It is believed that antigens released via secretion, excretion and metabolism are more specific than are antigens released by the lysis of Leishmania parasites. Such antigens are known as exo-antigens (exo-Ag) and are formed from products released by cultured parasites in a way that is similar to that in which they cause infections in hosts. We attempted to validate a Leishmania mexicana ELISA exo-Ag for ATL diagnosis in Midwestern Brazil. A total of 281 patients were included in the study. We analysed pre-treatment blood from 98 ATL patients; out of those, 85.7% and 14.3% had cutaneous and mucosal forms, respectively. The exo-Ag accuracy was 83.99% (95% CI=79.24-87.81) with a sensitivity value of 90.82% (95% CI=83.46-95.09) and an overall specificity value of 80.33% (95% CI=73.97-85.44). The positive predictive value and negative predictive value were 71.20% (95% CI=62.72-78.41) and 94.23% (95% CI=89.40-96.94), respectively. Among healthy controls, exo-Ag had a specificity of 91.25% (95% CI=83.02-95.70); additionally, the test had specificity rates of 66.67% (95% CI=46.71-82.03) in Chagas disease patients, 60.61% (95% CI=43.68-75.32) in patients with rheumatic diseases, 76.92% (95% CI=49.74-91.82) in pemphigus foliaceus patients, 87.50% (95% CI=52.91-97.76) in leprosy patients, 87.50% (95% CI=63.98-96.50) in VRDL-positive patients, and 77.78 (95% CI=45.26-93.68) in deep mycosis patients. Based on the indicators of validity, we conclude that the results obtained in this study enable the recommendation of the exo-Ag ELISA for ATL diagnosis once it presented a reasonable accuracy compared to classical methods. Cost evaluations are necessary to completely define the role of this technique in large scale. Copyright © 2015 Elsevier Editora Ltda. All rights reserved.

  19. La Artesania Mexicana (Mexican Handicrafts).

    ERIC Educational Resources Information Center

    Steele, Bettina

    This booklet contains instructions in English and Spanish for making eleven typical Mexican craft articles. The instructions are accompanied by pen-and-ink drawings. The objects are (1) "La Rosa" (The Rose); (2) "El Crisantemo" (The Chrysanthemum); (3) "La Amapola" (The Poppy); (4) "Ojos de Dios" (God's Eyes); (5) "Ojitos con dos caras" (Two-Sided…

  20. La Artesania Mexicana (Mexican Handicrafts).

    ERIC Educational Resources Information Center

    Steele, Bettina

    This booklet contains instructions in English and Spanish for making eleven typical Mexican craft articles. The instructions are accompanied by pen-and-ink drawings. The objects are (1) "La Rosa" (The Rose); (2) "El Crisantemo" (The Chrysanthemum); (3) "La Amapola" (The Poppy); (4) "Ojos de Dios" (God's Eyes); (5) "Ojitos con dos caras" (Two-Sided…

  1. A unique, highly conserved secretory invertase is differentially expressed by promastigote developmental forms of all species of the human pathogen, Leishmania

    PubMed Central

    Lyda, Todd A.; Joshi, Manju B.; Andersen, John F.; Kelada, Andrew Y.; Owings, Joshua P.; Bates, Paul A.; Dwyer, Dennis M.

    2015-01-01

    Leishmania are protozoan pathogens of humans that exist as extracellular promastigotes in the gut of their sand fly vectors and as obligate intracellular amastigotes within phagolysosomes of infected macrophages. Between infectious blood meal feeds, sand flies take plant juice meals that contain sucrose and store these sugars in their crop. Such sugars are regurgitated into the sand fly anterior midgut where they impact the developing promastigote parasite population. In this report we showed that promastigotes of all Leishmania species secreted an invertase/sucrase enzyme during their growth in vitro. In contrast, neither L. donovani nor L. mexicana amastigotes possessed any detectable invertase activity. Importantly, no released/secreted invertase activity was detected in culture supernatants from either Trypanosoma brucei or Trypanosoma cruzi. Using HPLC, the L. donovani secretory invertase was isolated and subjected to amino acid sequencing. Subsequently, we used a molecular approach to identify the LdINV and LmexINV genes encoding the ~72 kDa invertases produced by these organisms. Interestingly, we identified high fidelity LdINV-like homologs in the genomes of all Leishmania sp. but none were present in either T. brucei or T. cruzi. Northern blot and RT-PCR analyses showed that these genes were developmentally/differentially expressed in promastigotes but not amastigotes of these parasites. Homologous transfection studies demonstrated that these genes in fact encoded the functional secretory invertases produced by these parasites. Cumulatively, our results suggest that these secretory enzymes play critical roles in the survival/growth/development and transmission of all Leishmania parasites within their sand fly vector hosts. PMID:25763714

  2. A unique, highly conserved secretory invertase is differentially expressed by promastigote developmental forms of all species of the human pathogen, Leishmania.

    PubMed

    Lyda, Todd A; Joshi, Manju B; Andersen, John F; Kelada, Andrew Y; Owings, Joshua P; Bates, Paul A; Dwyer, Dennis M

    2015-06-01

    Leishmania are protozoan pathogens of humans that exist as extracellular promastigotes in the gut of their sand fly vectors and as obligate intracellular amastigotes within phagolysosomes of infected macrophages. Between infectious blood meal feeds, sand flies take plant juice meals that contain sucrose and store these sugars in their crop. Such sugars are regurgitated into the sand fly anterior midgut where they impact the developing promastigote parasite population. In this report we showed that promastigotes of all Leishmania species secreted an invertase/sucrase enzyme during their growth in vitro. In contrast, neither L. donovani nor L. mexicana amastigotes possessed any detectable invertase activity. Importantly, no released/secreted invertase activity was detected in culture supernatants from either Trypanosoma brucei or Trypanosoma cruzi. Using HPLC, the L. donovani secretory invertase was isolated and subjected to amino acid sequencing. Subsequently, we used a molecular approach to identify the LdINV and LmexINV genes encoding the ~72 kDa invertases produced by these organisms. Interestingly, we identified high fidelity LdINV-like homologs in the genomes of all Leishmania sp. but none were present in either T. brucei or T. cruzi. Northern blot and RT-PCR analyses showed that these genes were developmentally/differentially expressed in promastigotes but not amastigotes of these parasites. Homologous transfection studies demonstrated that these genes in fact encoded the functional secretory invertases produced by these parasites. Cumulatively, our results suggest that these secretory enzymes play critical roles in the survival/growth/development and transmission of all Leishmania parasites within their sand fly vector hosts.

  3. Complement Interaction with Trypanosomatid Promastigotes in Normal Human Serum

    PubMed Central

    Domínguez, Mercedes; Moreno, Inmaculada; López-Trascasa, Margarita; Toraño, Alfredo

    2002-01-01

    In normal human serum (NHS), axenic promastigotes of Crithidia, Phytomonas, and Leishmania trigger complement activation, and from 1.2 to 1.8 × 105 C3 molecules are deposited per promastigote within 2.5 min. In Leishmania, promastigote C3 binding capacity remains constant during in vitro metacyclogenesis. C3 deposition on promastigotes activated through the classical complement pathway reaches a 50% maximum after ∼50 s, and represents >85% of total C3 bound. In C1q- and C2-deficient human sera, promastigotes cannot activate the classical pathway (CP) unless purified C1q or C2 factors, respectively, are supplemented, demonstrating a requirement for CP factor in promastigote C3 opsonization. NHS depleted of natural anti-Leishmania antibodies cannot trigger promastigote CP activation, but IgM addition restores C3 binding. Furthermore, Leishmania binds natural antibodies in ethylenediaminetetracetic acid (EDTA)-treated NHS; after EDTA removal, promastigote-bound IgM triggers C3 deposition in natural antibody-depleted NHS. Serum collectins and pentraxins thus do not participate significantly in NHS promastigote C3 opsonization. Real-time kinetic analysis of promastigote CP-mediated lysis indicates that between 85–95% of parasites are killed within 2.5 min of serum contact. These data indicate that successful Leishmania infection in man must immediately follow promastigote transmission, and that Leishmania evasion strategies are shaped by the selective pressure exerted by complement. PMID:11854358

  4. La Experiencia Mexicana (The Mexican Experience). Volumes I and II.

    ERIC Educational Resources Information Center

    Finer, Neal B.

    Designed to be used as part of a comprehensive social studies program on Mexican culture, this two-volume manual, written in Spanish, offers an instructional package on Mexican culture, stressing an art-architecture perspective, which can be used at the secondary, college and adult levels. The teacher's guide, Volume I, includes a discussion of a…

  5. A Mexicana Woman's Education in 1980s Chicago

    ERIC Educational Resources Information Center

    Rivera, Angelica

    2012-01-01

    The purpose of this paper is to describe the educational experiences of a Mexican woman in Chicago's Little Village community in the 1980s. The author was born in Mexico and raised in Little Village which has been home to Mexican immigrant communities for decades. Little Village is also home to the largest Mexican-American population in the…

  6. A Mexicana Woman's Education in 1980s Chicago

    ERIC Educational Resources Information Center

    Rivera, Angelica

    2012-01-01

    The purpose of this paper is to describe the educational experiences of a Mexican woman in Chicago's Little Village community in the 1980s. The author was born in Mexico and raised in Little Village which has been home to Mexican immigrant communities for decades. Little Village is also home to the largest Mexican-American population in the…

  7. Cultural Appropriation, Performance, and Agency in Mexicana Parent Involvement

    ERIC Educational Resources Information Center

    Galindo, Rene; Medina, Christina

    2009-01-01

    Parental agency is examined in the creation of a dance performance by a group of Mexican immigrant mothers that combined a mixture of genres into an educational message. The "folklorico" performance resulted from a process of cultural appropriation involving linguistic, cultural, and experiential "translations." This process was concerned with…

  8. Cultural Appropriation, Performance, and Agency in Mexicana Parent Involvement

    ERIC Educational Resources Information Center

    Galindo, Rene; Medina, Christina

    2009-01-01

    Parental agency is examined in the creation of a dance performance by a group of Mexican immigrant mothers that combined a mixture of genres into an educational message. The "folklorico" performance resulted from a process of cultural appropriation involving linguistic, cultural, and experiential "translations." This process was concerned with…

  9. La Experiencia Mexicana (The Mexican Experience). Volumes I and II.

    ERIC Educational Resources Information Center

    Finer, Neal B.

    Designed to be used as part of a comprehensive social studies program on Mexican culture, this two-volume manual, written in Spanish, offers an instructional package on Mexican culture, stressing an art-architecture perspective, which can be used at the secondary, college and adult levels. The teacher's guide, Volume I, includes a discussion of a…

  10. Biochemistry and Chemotherapy of Malaria and Leishmaniasis

    DTIC Science & Technology

    1993-12-06

    sativum), elephant garlic (Allium scorodoprasum), onion (Allium cepa), and licorice ( Glycyrrhiza glabra). Cells of Leish- mania mexicana 227 and... Glycyrrhiza glabra) inhibited the growth of the leishmanial parasites, but were not toxic to HeLa cells. All of the extracts showed varying inhibitory...root) and Glycyrrhiza glabra (licorice). 10 * Materials & Methods Cultures of Parasitic Protozoa: Promastigotes of Leishmania mexicana Walter Reed

  11. Attenuation of Leishmania infantum chagasi metacyclic promastigotes by sterol depletion.

    PubMed

    Yao, Chaoqun; Gaur Dixit, Upasna; Barker, Jason H; Teesch, Lynn M; Love-Homan, Laurie; Donelson, John E; Wilson, Mary E

    2013-07-01

    The infectious metacyclic promastigotes of Leishmania protozoa establish infection in a mammalian host after they are deposited into the dermis by a sand fly vector. Several Leishmania virulence factors promote infection, including the glycosylphosphatidylinositol membrane-anchored major surface protease (MSP). Metacyclic Leishmania infantum chagasi promastigotes were treated with methyl-beta-cyclodextrin (MβCD), a sterol-chelating reagent, causing a 3-fold reduction in total cellular sterols as well as enhancing MSP release without affecting parasite viability in vitro. MβCD-treated promastigotes were more susceptible to complement-mediated lysis than untreated controls and reduced the parasite load 3-fold when inoculated into BALB/c mice. Paradoxically, MβCD-treated promastigotes caused a higher initial in vitro infection rate in human or murine macrophages than untreated controls, although their intracellular multiplication was hindered upon infection establishment. There was a corresponding larger amount of covalently bound C3b than iC3b on the parasite surfaces of MβCD-treated promastigotes exposed to healthy human serum in vitro, as well as loss of MSP, a protease that enhances C3b cleavage to iC3b. Mass spectrometry showed that MβCD promotes the release of proteins into the extracellular medium, including both MSP and MSP-like protein (MLP), from virulent metacyclic promastigotes. These data support the hypothesis that plasma membrane sterols are important for the virulence of Leishmania protozoa at least in part through retention of membrane virulence proteins.

  12. Attenuation of Leishmania infantum chagasi Metacyclic Promastigotes by Sterol Depletion

    PubMed Central

    Gaur Dixit, Upasna; Barker, Jason H.; Teesch, Lynn M.; Love-Homan, Laurie; Donelson, John E.; Wilson, Mary E.

    2013-01-01

    The infectious metacyclic promastigotes of Leishmania protozoa establish infection in a mammalian host after they are deposited into the dermis by a sand fly vector. Several Leishmania virulence factors promote infection, including the glycosylphosphatidylinositol membrane-anchored major surface protease (MSP). Metacyclic Leishmania infantum chagasi promastigotes were treated with methyl-beta-cyclodextrin (MβCD), a sterol-chelating reagent, causing a 3-fold reduction in total cellular sterols as well as enhancing MSP release without affecting parasite viability in vitro. MβCD-treated promastigotes were more susceptible to complement-mediated lysis than untreated controls and reduced the parasite load 3-fold when inoculated into BALB/c mice. Paradoxically, MβCD-treated promastigotes caused a higher initial in vitro infection rate in human or murine macrophages than untreated controls, although their intracellular multiplication was hindered upon infection establishment. There was a corresponding larger amount of covalently bound C3b than iC3b on the parasite surfaces of MβCD-treated promastigotes exposed to healthy human serum in vitro, as well as loss of MSP, a protease that enhances C3b cleavage to iC3b. Mass spectrometry showed that MβCD promotes the release of proteins into the extracellular medium, including both MSP and MSP-like protein (MLP), from virulent metacyclic promastigotes. These data support the hypothesis that plasma membrane sterols are important for the virulence of Leishmania protozoa at least in part through retention of membrane virulence proteins. PMID:23630964

  13. Tamoxifen Induces Apoptosis of Leishmania major Promastigotes in Vitro.

    PubMed

    Doroodgar, Masoud; Delavari, Mahdi; Doroodgar, Moein; Abbasi, Ali; Taherian, Ali Akbar; Doroodgar, Abbas

    2016-02-01

    Tamoxifen is an antagonist of the estrogen receptor and currently used for the treatment of breast cancer. The current treatment of cutaneous leishmaniasis with pentavalent antimony compounds is not satisfactory. Therefore, in this study, due to its antileishmanial activity, effects of tamoxifen on the growth of promastigotes and amastigotes of Leishmania major Iranian strain were evaluated in vitro. Promastigotes and amastigotes were treated with different concentrations (1, 5, 10, 20, and 50 μg/ml) and time periods (24, 48, and 72 hr) of tamoxifen. After tamoxifen treatment, MTT assay (3-[4,5-dimethylthiazol-2-yl]-2,5 biphenyl tetrazolium bromide assay) was used to determine the percentage of live parasites and Graph Pad Prism software to calculate IC50. Flow cytometry was applied to investigate the induction of tamoxifen-induced apoptosis in promastigotes. The half maximal inhibitory concentration (IC50) of tamoxifen on promastigotes was 2.6 μg/ml after 24 hr treatment. Flow cytometry analysis showed that tamoxifen induced early and late apoptosis in Leishmania promastigotes. While after 48 hr in control group the apoptosis was 2.0%, the 50 µg/L concentration of tamoxifen increased it to 59.7%. Based on the in vitro antileishmanial effect, tamoxifen might be used for leishmaniasis treatment; however, further researches on in vivo effects of tamoxifen in animal models are needed.

  14. Holothuria leucospilota Extract Induces Apoptosis in Leishmania major Promastigotes

    PubMed Central

    FOROUTAN-RAD, Masoud; KHADEMVATAN, Shahram; SAKI, Jasem; HASHEMITABAR, Mahmoud

    2016-01-01

    Background: The present study aimed to survey antileishmanial activity of methanolic Holothuria leucospilota extract against Leishmania major promastigotes in vitro. Methods: Promastigotes were cultured in RPMI 1640 and after reaching the stationary phase, the study was conducted with different concentrations of the extract. Afterwards, MTT colorimetric assay for the obtaining of 50% inhibitory concentration (IC50) was utilized. Furthermore, in order to determine the possible induction of apoptosis in L. major promastigotes, flow cytometry and DNA fragmentation methods were employed using annexin-V FLUOS staining kit and DNA ladder kit, respectively. Results: The IC50 value of H. leucospilota extract at three time points of 24, 48, and 72 h was estimated 2000, 300 and 85 μg/ml, respectively. In addition, the extract revealed a dose and time-dependent antileishmanial activity. Furthermore, various characteristics of apoptosis appeared after L. major promastigotes treatment, which included cell shrinkage, formation of apoptotic bodies, blebbing of the cell membrane, and externalization of phosphatidylserine, although no laddering pattern was observed. Conclusion: The methanolic extract of H. leucospilota possesses lethal effect on L. major promastigotes and induces the apoptosis in parasites. Further studies are required to address the apoptosis mechanism in vivo. PMID:28127339

  15. Partial anaerobiosis induces infectivity of Leishmania infantum promastigotes.

    PubMed

    Méndez, S; Fernández-Pérez, F J; de la Fuente, C; Cuquerella, M; Gómez-Muñoz, M T; Alunda, J M

    1999-06-01

    Leishmania infantum stationary-phase promastigotes could acquire infectivity via preincubation in a partially anaerobic medium (95% air/5% CO2) for 16 h before the infection, whereas promastigotes were efficiently destroyed when no CO2 was present. Incubation of L. infantum promastigotes with additional glucose (20 and 50 mM) greatly increased infection parameters in the absence of CO2; this is consistent with a "reverse Pasteur effect." Results showed that culture at 33 degrees C permitted survival and amastigote multiplication (a nearly 10-fold increase in amastigotes as compared with those observed in 37 degrees C cultures). This finding was obtained with the two strains of L. infantum tested (Doba and PB75).

  16. Leishmania infantum: infection of macrophages in vitro with promastigotes.

    PubMed

    Méndez, S; Nell, M; Alunda, J M

    1996-06-01

    Leishmania infantum promastigotes in axenic culture exhibit limited infectivity for mouse peritoneal macrophages (M phi) in vitro using standard culture conditions (37 degrees C; 95% air/5% CO2) compared to Leishmania donovani promastigotes which induce notable infections. The infectivity of logarithmic (log) and stationary (stat) phase promastigotes of L. infantum was enhanced by the addition of fresh homologous serum, but no amastigotes were observed after 4 days. Prolonged infections, including transformation and survival of intracellular amastigotes in BALB/c mouse and hamster resident peritoneal M phi and M phi cell line J774.G8 were obtained by incubating M phi for 48 h at 26 degrees C prior to standard culture. Enhanced infectivity was observed in a number of L. infantum strains subject to this transient thermal change.

  17. The activity of ozonated olive oil against Leishmania major promastigotes

    PubMed Central

    Rajabi, Omid; Sazgarnia, Ameneh; Abbasi, Fatemeh; Layegh, Pouran

    2015-01-01

    Objective(s): Cutaneous Leishmaniasis is a common and endemic disease in Khorasan province in North-East of Iran. The pentavalant antimony (Sb V) is the mainstay of treatment that has many side effects and resistance to the drug has been reported. The microbicidal effect of ozone was proven in different microorganisms. Since there is no study in this respect and to achieve a low cost and effective treatment, we decided to evaluate the efficacy of ozone against promastigotes of Leishmania major, in vitro. Materials and Methods: Ozonated olive oil was prepared after production of ozone by bubbling ozone-oxygen gas produced by ozone generator through olive oil until it solidified. Promastigotes of L. major were cultivated in two phasic media. After calculation of the number of promastigotes, they were incubated with ozonated olive oil (0, 0.626, 0.938, 1.25, 2.5, 5, 10 mcg/ml) at 28 °c for 24 hr. Parasites survival percentage was evaluated using MTS and microscopic assay, and then compared with Glucantime and non-ozonated olive oil. Results: According to the results, there were significant differences in parasites survival percentage between ozonated olive oil and non-ozonated olive oil, at similar concentrations (P<0.001). Ozonated olive oil was more effective than Glucantime. According to MTS results, Glucantime and ozonated olive oil gel concentrations that are required to inhibit the growth of L. major promastigotes by 50% (IC50), were 165 and 0.002 mg/ml, respectively. Conclusion: Ozonated olive oil has in vitro activity against the promastigotes of L. major and this effect is dose dependent. PMID:26523224

  18. POPULATION CHANGES IN LEISHMANIA CHAGASI PROMASTIGOTE DEVELOPMENTAL STAGES DUE TO SERIAL PASSAGE

    PubMed Central

    Lei, Soi Meng; Romine, Nathan M.; Beetham, Jeffrey K.

    2013-01-01

    Leishmania chagasi causes visceral leishmaniasis, a potentially fatal disease of humans. Within the sand fly vector, L. chagasi replicates as promastigotes which undergo complex changes in morphology as they progress from early stage procyclic promastigotes, to intermediate stage leptomonad and nectomonad promastigotes, and ultimately to terminal stage metacyclic promastigotes that are highly infective to vertebrates. This developmental progression is largely recapitulated in vitro using axenic promastigote cultures that have been passaged only a few times. Within a single passage (which takes about a week), axenic cultures progress from logarithmic to stationary growth phases; parasites within those growth phases progress from stages that do not have metacyclic cell properties to ones that do. Interestingly, repeated serial passage of promastigote cultures will result in cell populations that exhibit perturbations in developmental progression, in expression levels of surface macromolecules (major surface protease, MSP, and promastigote surface antigen, PSA), and in virulence properties, including resistance to serum lysis. Experiments were performed to determine whether there exists a direct relationship between promastigote developmental form and perturbations associated with repeated serial passage. Passage 2 to passage 4 L. chagasi cultures at stationary growth phase were predominately (>85%) comprised of metacyclic promastigotes and exhibited high resistance to serum lysis and high levels of MSP and PSA. Serial passaging 8, or more, times resulted in a stationary phase population that was largely (>85%) comprised of nectomonad promastigotes, almost completely devoid (<2%) of metacyclic promastigotes, and that exhibited low resistance to serum lysis and low levels of MSP and PSA. The study suggests that the loss of particular cell properties seen in cells from serially passaged cultures is principally due to a dramatic reduction in the proportion of metacyclic

  19. Population changes in Leishmania chagasi promastigote developmental stages due to serial passage.

    PubMed

    Lei, Soi Meng; Romine, Nathan M; Beetham, Jeffrey K

    2010-12-01

    Leishmania chagasi causes visceral leishmaniasis, a potentially fatal disease of humans. Within the sand fly vector, L. chagasi replicates as promastigotes which undergo complex changes in morphology as they progress from early stage procyclic promastigotes, to intermediate stage leptomonad and nectomonad promastigotes, and ultimately to terminal stage metacyclic promastigotes that are highly infective to vertebrates. This developmental progression is largely recapitulated in vitro using axenic promastigote cultures that have been passaged only a few times. Within a single passage (which takes about a week), axenic cultures progress from logarithmic to stationary growth phases; parasites within those growth phases progress from stages that do not have metacyclic cell properties to ones that do. Interestingly, repeated serial passage of promastigote cultures will result in cell populations that exhibit perturbations in developmental progression, in expression levels of surface macromolecules (major surface protease, MSP, and promastigote surface antigen, PSA), and in virulence properties, including resistance to serum lysis. Experiments were performed to determine whether there exists a direct relationship between promastigote developmental form and perturbations associated with repeated serial passage. Passage 2 to passage 4 L. chagasi cultures at stationary growth phase were predominately (>85%) comprised of metacyclic promastigotes and exhibited high resistance to serum lysis and high levels of MSP and PSA. Serial passaging 8, or more, times resulted in a stationary phase population that was largely (>85%) comprised of nectomonad promastigotes, almost completely devoid (<2%) of metacyclic promastigotes, and that exhibited low resistance to serum lysis and low levels of MSP and PSA. The study suggests that the loss of particular cell properties seen in cells from serially passaged cultures is principally due to a dramatic reduction in the proportion of metacyclic

  20. Metabolic Variation during Development in Culture of Leishmania donovani Promastigotes

    PubMed Central

    Silva, Ana Marta; Cordeiro-da-Silva, Anabela; Coombs, Graham H.

    2011-01-01

    The genome sequencing of several Leishmania species has provided immense amounts of data and allowed the prediction of the metabolic pathways potentially operating. Subsequent genetic and proteomic studies have identified stage-specific proteins and putative virulence factors but many aspects of the metabolic adaptations of Leishmania remain to be elucidated. In this study, we have used an untargeted metabolomics approach to analyze changes in the metabolite profile as promastigotes of L. donovani develop during in vitro cultures from logarithmic to stationary phase. The results show that the metabolomes of promastigotes on days 3–6 of culture differ significantly from each other, consistent with there being distinct developmental changes. Most notable were the structural changes in glycerophospholipids and increase in the abundance of sphingolipids and glycerolipids as cells progress from logarithmic to stationary phase. PMID:22206037

  1. Differential surface deposition of complement proteins on logarithmic and stationary phase Leishmania chagasi promastigotes.

    PubMed

    Ramer-Tait, Amanda E; Lei, Soi Meng; Bellaire, Bryan H; Beetham, Jeffrey K

    2012-12-01

    Previous works demonstrated that various species of Leishmania promastigotes exhibit differential sensitivity to complement-mediated lysis (CML) during development. Upon exposure to normal human serum (NHS), cultures of Leishmania chagasi promastigotes recently isolated from infected hamsters (fewer than 5 in vitro passages) are CML-sensitive when in the logarithmic growth phase but become CML-resistant upon transition to the stationary culture phase. Visualization by light and electron microscopy revealed dramatic morphological differences between promastigotes from the 2 culture phases following exposure to NHS. Flow cytometric analysis demonstrated that surface deposition of the complement components C3, C5, and C9 correlated inversely with promastigote CML-resistance. The highest levels of complement protein surface accumulation were observed for logarithmic phase promastigotes, while stationary phase promastigotes adsorbed the least amount of complement proteins. Additionally, fluorescence microscopy revealed that C3 and C5 localized in a fairly uniform pattern to the plasma membrane of promastigotes from logarithmic phase cultures, while the staining of promastigotes from stationary phase cultures was indistinguishable from background. By Western blot analysis, high levels of the complement proteins C3, C5, and C9 were detected in the total lysates of NHS-exposed logarithmic phase L. chagasi promastigotes, relative to NHS-exposed stationary phase promastigotes; this finding indicates that the low levels of C3 and C5 seen on the surface of stationary phase promastigotes were not due to protein uptake/internalization. Together, these data demonstrate the differential deposition of complement proteins on the surfaces of logarithmic and stationary phase L. chagasi promastigotes. The data support a model wherein stationary phase L. chagasi promastigotes resist CML by limiting the deposition of C3 and its derivatives, which, in turn, limit surface levels of

  2. Metacyclogenesis is a major determinant of Leishmania promastigote virulence and attenuation.

    PubMed

    da Silva, R; Sacks, D L

    1987-11-01

    The in vivo virulence patterns of promastigote populations defined on the basis of agglutination by the lectin peanut agglutinin (PNA) were studied for various cloned lines of Leishmania major. Promastigotes derived from logarithmic-phase cultures, which were routinely 100% agglutinated at 100 micrograms of PNA per ml, were relatively avirulent for BALB/c mice. The relative virulence of stationary-phase promastigotes appeared to be attributable to the proportion of nonagglutinable (PNA-) promastigotes contained within these populations. Purification of PNA- organisms from stationary cultures provided for each clone the most virulent inoculum, supporting the view that this change in lectin binding accurately reflects the development of infective metacyclic stage promastigotes. By studying this marker, we found that there was considerable variation in the degree to which different strains and clones underwent metacyclogenesis during growth. Examination of a reportedly avirulent L. major clone revealed that metacyclogenesis was unusually delayed and inefficient for this clone, but that those PNA- promastigotes which could be recovered from late-stationary-phase cultures were virulent for BALB/c mice. The loss of virulence associated with frequent subculture could also be attributed to a drastic diminution in metacyclogenesis potential over time. A clone which yielded over 90% PNA- promastigotes during growth within passage 1 generated fewer than 10% PNA- promastigotes during growth by passage 94. Subcloning of late-passage attenuated promastigotes yielded a clone for which no PNA- promastigotes could be generated during growth, and an infective population could not be derived from this clone. Thus, metacyclogenesis does not appear to be stable for even cloned lines of Leishmania promastigotes, and virulence comparisons between different strains and clones can be meaningfully made only if the metacyclic populations contained within the respective inocula are determined.

  3. Encapsulation of Living Leishmania Promastigotes in Artificial Lipid Vacuoles.

    PubMed

    Guedes, Carlos E S; Lima, Jose G B; Helfer, Emmanuèle; Veras, Patricia S T; Viallat, Annie

    2015-01-01

    After phagocytosis by mammalian macrophages, promastigote forms of Leishmania parasites settle inside intracellular parasitophorous vacuoles (PVs) in which they transform into amastigote forms and replicate. Here, using a variant of the 'inverted emulsion' method, we succeeded in encapsulating living L. amazonensis parasites in giant artificial liposomes that serve as model PVs. We were able to control the size of liposomes, the pH and the composition of their internal volume, and the number of internalized parasites per liposome. L. amazonensis promastigotes encapsulated in liposomes filled with RPMI-Dextran solution at pH 7.5 or 6.5 survived up to 96 h at 24°C. At 37°C and pH 5.5, parasites survived 48h. This method paves the way to identifying certain effectors secreted by the parasite and to unraveling specific mechanisms of fusion between the PV and intracellular vesicles of the host cell. This method will also facilitate the study of the temporal evolution of biophysical properties of the PV during its maturation.

  4. Serine protease activities in Leishmania (Leishmania) chagasi promastigotes.

    PubMed

    da Silva-López, Raquel Elisa; dos Santos, Tatiana Resende; Morgado-Díaz, José Andrés; Tanaka, Marcelo Neves; de Simone, Salvatore Giovanni

    2010-10-01

    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 temperature for all enzymes was 37°C, using α-N-ρ-tosyl-L: -arginine methyl ester as substrate. Assay of thermal stability indicated that LCSIII is the more stable enzyme. Hemoglobin, bovine serum albumin, and ovalbumin were hydrolyzed by LCSII and LCSI but not by LCSIII. Inhibition studies suggested that enzymes belong to the serine protease class modulated by divalent cations. Rabbit antiserum against 56-kDa serine protease of Leishmania amazonensis identified proteins in all extracts of L. chagasi. Furthermore, immunocytochemistry demonstrated that serine proteases are located in flagellar pocket region and cytoplasmic vesicles of L. chagasi promastigotes. These findings indicate that L. chagasi serine proteases differ from L. amazonensis proteases and all known flagellate proteases, but display some similarities with serine proteases from other Leishmania species, suggesting a conservation of this enzymatic activity in the genus.

  5. Influence of the Microenvironment in the Transcriptome of Leishmania infantum Promastigotes: Sand Fly versus Culture.

    PubMed

    Alcolea, Pedro J; Alonso, Ana; Domínguez, Mercedes; Parro, Víctor; Jiménez, Maribel; Molina, Ricardo; Larraga, Vicente

    2016-05-01

    Zoonotic visceral leishmaniasis is a vector-borne disease caused by Leishmania infantum in the Mediterranean Basin, where domestic dogs and wild canids are the main reservoirs. The promastigote stage replicates and develops within the gut of blood-sucking phlebotomine sand flies. Mature promastigotes are injected in the dermis of the mammalian host and differentiate into the amastigote stage within parasitophorous vacuoles of phagocytic cells. The major vector of L. infantum in Spain is Phlebotomus perniciosus. Promastigotes are routinely axenized and cultured to mimic in vitro the conditions inside the insect gut, which allows for most molecular, cellular, immunological and therapeutical studies otherwise inviable. Culture passages are known to decrease infectivity, which is restored by passage through laboratory animals. The most appropriate source of promastigotes is the gut of the vector host but isolation of the parasite is technically challenging. In fact, this option is not viable unless small samples are sufficient for downstream applications like promastigote cultures and nucleic acid amplification. In this study, in vitro infectivity and differential gene expression have been studied in cultured promastigotes at the stationary phase and in promastigotes isolated from the stomodeal valve of the sand fly P. perniciosus. About 20 ng RNA per sample could be isolated. Each sample contained L. infantum promastigotes from 20 sand flies. RNA was successfully amplified and processed for shotgun genome microarray hybridization analysis. Most differentially regulated genes are involved in regulation of gene expression, intracellular signaling, amino acid metabolism and biosynthesis of surface molecules. Interestingly, meta-analysis by hierarchical clustering supports that up-regulation of 22.4% of the differentially regulated genes is specifically enhanced by the microenvironment (i.e. sand fly gut or culture). The correlation between cultured and naturally

  6. Influence of the Microenvironment in the Transcriptome of Leishmania infantum Promastigotes: Sand Fly versus Culture

    PubMed Central

    Alcolea, Pedro J.; Alonso, Ana; Domínguez, Mercedes; Parro, Víctor; Jiménez, Maribel; Molina, Ricardo; Larraga, Vicente

    2016-01-01

    Zoonotic visceral leishmaniasis is a vector-borne disease caused by Leishmania infantum in the Mediterranean Basin, where domestic dogs and wild canids are the main reservoirs. The promastigote stage replicates and develops within the gut of blood-sucking phlebotomine sand flies. Mature promastigotes are injected in the dermis of the mammalian host and differentiate into the amastigote stage within parasitophorous vacuoles of phagocytic cells. The major vector of L. infantum in Spain is Phlebotomus perniciosus. Promastigotes are routinely axenized and cultured to mimic in vitro the conditions inside the insect gut, which allows for most molecular, cellular, immunological and therapeutical studies otherwise inviable. Culture passages are known to decrease infectivity, which is restored by passage through laboratory animals. The most appropriate source of promastigotes is the gut of the vector host but isolation of the parasite is technically challenging. In fact, this option is not viable unless small samples are sufficient for downstream applications like promastigote cultures and nucleic acid amplification. In this study, in vitro infectivity and differential gene expression have been studied in cultured promastigotes at the stationary phase and in promastigotes isolated from the stomodeal valve of the sand fly P. perniciosus. About 20 ng RNA per sample could be isolated. Each sample contained L. infantum promastigotes from 20 sand flies. RNA was successfully amplified and processed for shotgun genome microarray hybridization analysis. Most differentially regulated genes are involved in regulation of gene expression, intracellular signaling, amino acid metabolism and biosynthesis of surface molecules. Interestingly, meta-analysis by hierarchical clustering supports that up-regulation of 22.4% of the differentially regulated genes is specifically enhanced by the microenvironment (i.e. sand fly gut or culture). The correlation between cultured and naturally

  7. Differences in human macrophage receptor usage, lysosomal fusion kinetics and survival between logarithmic and metacyclic Leishmania infantum chagasi promastigotes.

    PubMed

    Ueno, Norikiyo; Bratt, Carol L; Rodriguez, Nilda E; Wilson, Mary E

    2009-12-01

    The obligate intracellular protozoan, Leishmania infantum chagasi (Lic) undergoes receptor-mediated phagocytosis by macrophages followed by a transient delay in phagolysosome maturation. We found differences in the pathway through which virulent Lic metacyclic promastigotes or avirulent logarithmic promastigotes are phagocytosed by human monocyte-derived macrophages (MDMs). Both logarithmic and metacyclic promastigotes entered MDMs through a compartment lined by the third complement receptor (CR3). In contrast, many logarithmic promastigotes entered through vacuoles lined by mannose receptors (MR) whereas most metacyclic promastigotes did not (P < 0.005). CR3-positive vacuoles containing metacyclic promastigotes stained for caveolin-1 protein, suggesting CR3 localizes in caveolae during phagocytosis. Following entry, the kinetics of phagolysosomal maturation and intracellular survival also differed. Vacuoles containing metacyclic parasites did not accumulate lysosome-associated membrane protein-1 (LAMP-1) at early times after phagocytosis, whereas vacuoles with logarithmic promastigotes did. MDMs phagocytosed greater numbers of logarithmic than metacyclic promastigotes, yet metacyclics ultimately replicated intracellularly with greater efficiency. These data suggest that virulent metacyclic Leishmania promastigotes fail to ligate macrophage MR, and enter through a path that ultimately enhances intracellular survival. The relatively quiescent entry of virulent Leishmania spp. into macrophages may be accounted for by the ability of metacyclic promastigotes to selectively bypass deleterious entry pathways.

  8. Occurrence of entomopathogenic fungi in tejocote (Crataegus mexicana) orchard soils and their pathogenicity against Rhagoletis pomonella.

    PubMed

    Muñiz-Reyes, E; Guzmán-Franco, A W; Sánchez-Escudero, J; Nieto-Angel, R

    2014-11-01

    To determine the abundance and diversity of entomopathogenic fungi in tejocote orchard soils and evaluate their ability to infect Rhagoletis pomonella Walsh., the main pest of tejocote. Surveys were made in two locations in Mexico state and two in Puebla state. Soil from selected locations was baited for entomopathogenic fungi with Galleria mellonella (L.). All isolates were identified morphologically to genus level and to species level using Bloc and elongation factor 1-α gene sequence information, respectively; Beauveria bassiana ((Bals.-Criv.) Vuill.), B. pseudobassiana (S.A. Rehner & Humber) and Metarhizium robertsii (J.F. Bisch., Rehner & Humber) were found, with B. bassiana being the most abundant and widely distributed. Pathogenicity of five selected B. bassiana isolates and three M. robertsii isolates was evaluated against larvae and pupae of R. pomonella. All isolates infected larvae resulting in an average mortality of 35%. Pupae were not susceptible; however, adults emerging from inoculated pupae did die due to infection. At least three species of entomopathogenic fungi are present in the soil from tejocote orchards, with B. bassiana being the most abundant and widely distributed. Rhagoletis pomonella larvae were more susceptible to infection than pupae. Our study has produced new information about the distribution of entomopathogenic fungi in cultivated soils from this region of North America, contributing to a better understanding of their natural occurrence and underpinning the development of biological control approaches. © 2014 The Society for Applied Microbiology.

  9. Exploring whether and how ants affect reproductive fitness in Senna mexicana var. chapmanii

    USDA-ARS?s Scientific Manuscript database

    Extrafloral nectar (EFN) mediates food-for-protection mutualisms between plants and ants. Ant-plant mutualisms are keystone associations, occurring within a complex web of biotic interactions. As such, these interactions may affect plant fitness in a number of ways, both positive and negative. In S...

  10. Unidad: Las influencias culturales en el arte mexicana (Unit: Cultural Influences in Mexican Art). Dos semanas.

    ERIC Educational Resources Information Center

    Finere, Neal

    This two-week unit, appropriate for bilingual education settings as well as foreign language programs, deals with the three primary cultural influences found in Mexican contemporary art. The multisensory materials, pragmatic focus, and direct creative student involvement are designed to make it a microcosmic, real-life experience. The first part…

  11. Unidad: Las influencias culturales en el arte mexicana (Unit: Cultural Influences in Mexican Art). Dos semanas.

    ERIC Educational Resources Information Center

    Finere, Neal

    This two-week unit, appropriate for bilingual education settings as well as foreign language programs, deals with the three primary cultural influences found in Mexican contemporary art. The multisensory materials, pragmatic focus, and direct creative student involvement are designed to make it a microcosmic, real-life experience. The first part…

  12. [Clinical guides in Mexico, emission of the Academia Mexicana de Cirugia].

    PubMed

    Sánchez-González, Jorge M; Tena-Tamayo, Carlos; Díaz-González, Norma Juárez; Vargas-Domínguez, Armando; Rivera-Cisneros, Antonio; Lozano-Alcázar, Jaime

    2004-01-01

    Today, these exist worldwide organizations related with the practice of medicine that are interested in marking recommendations and in formulating guidelines for better performance of physicians and health professionals. These organizations are headed by universities, associations, colleges, research center, and work groups and are made up of well-known physicians with academic prestige from the private and public sectors. This report presents a brief overview concerning the development of three clinical guides related with illnesses frequently observed in the physician's office: rhinosinusitis gastroesophageal reflux diseases (GERD), and prostate benign hyperplasia. These guides are issued by one of the most important academic institutions in the country. In the above-mentioned works, the efforts of specialist who are opinion leaders in these topics form different states of the country converge. Likewise, critical points to consider for producing clinical guides are provided mechanisms of diffusion, consultation, feedback and updating of these documents, have already been provided and focus on national medical practice quality of services, and the manner in which to carry out diagnosis and therapy at the different levels of medical care, with emphasis on preventing complications.

  13. Personas Mexicanas: Chicano High Schoolers in a Changing Los Angeles. Case Studies in Cultural Anthropology.

    ERIC Educational Resources Information Center

    Vigil, James Diego

    This book aims to provide a better understanding of Mexican American high school students and their struggles with ethnicity, Americanization, prejudice, schools, and life's purposes. In most Anglo minds, these students are characterized by exceptionally high dropout rates and poor school performance, without any explanation for this performance…

  14. Personas Mexicanas: Chicano High Schoolers in a Changing Los Angeles. Case Studies in Cultural Anthropology.

    ERIC Educational Resources Information Center

    Vigil, James Diego

    This book aims to provide a better understanding of Mexican American high school students and their struggles with ethnicity, Americanization, prejudice, schools, and life's purposes. In most Anglo minds, these students are characterized by exceptionally high dropout rates and poor school performance, without any explanation for this performance…

  15. Leishmania (Viannia) braziliensis: influence of successive in vitro cultivation on the expression of promastigote proteinases.

    PubMed

    Rebello, Karina Mastropasqua; Britto, Constança; Pereira, Bernardo Acácio Santini; Pita-Pereira, Daniela de; Moraes, Milton Ozório; Ferreira, Anna Beatriz Robottom; Cysne-Finkelstein, Léa; Otto, Thomas Dan; Côrtes, Luzia Monteiro de Castro; da-Silva, Gabriel Gomes; Alves, Carlos Roberto

    2010-12-01

    Cysteine proteinases are an important virulence factor in Leishmania parasites. In this study we analyzed the cysteine proteinase expression of infective Leishmania (Viannia) braziliensis promastigotes, examining the expression induced by successive in vitro passages in culture. We observed that this parasite presents a decrease in its virulence over BALB/c macrophages, after successive passages in culture, but still they present proteinase activity, being capable of hydrolyzing the substrate pGlu-Phe-Leu-p Nitroanilide at pH 7.0. This proteinase activity also decreases in the course of the successive passages. Additionally, the decrease in the amount of CPB proteins following successive passages of promastigotes was verified by immunoblotting assays, using an anti-CPB antiserum. Real-time PCR assays were performed to assess the relative cpb expression when compared to a housekeeping gene in promastigote cDNA preparations from the first, fourth and seventh passages. Interestingly, the data indicate a relative increase in cpb gene transcripts as the promastigotes were maintained under in vitro culture: 2.2 times higher for fourth and 2.7 times higher for seventh passages when compared to the first passage. Thus, the information gathered here shows that the expression of cysteine proteinases is modified during in vitro cultivation of L. (V.) braziliensis promastigotes.

  16. Cryptolepine-Induced Cell Death of Leishmania donovani Promastigotes Is Augmented by Inhibition of Autophagy

    PubMed Central

    Sengupta, Souvik; Chowdhury, Sayan; BoseDasgupta, Somdeb; Wright, Colin W.; Majumder, Hemanta K.

    2011-01-01

    Leishmania donovani are the causative agents of visceral leishmaniasis worldwide. Lack of vaccines and emergence of drug resistance warrants the need for improved drug therapy and newer therapeutic intervention strategies against leishmaniasis. In the present study, we have investigated the effect of the natural indoloquinoline alkaloid cryptolepine on L. donovani AG83 promastigotes. Our results show that cryptolepine induces cellular dysfunction in L. donovani promastigotes, which leads to the death of this unicellular parasite. Interestingly, our study suggest that cryptolepine-induced cell death of L. donovani is counteracted by initial autophagic features elicited by the cells. For the first time, we show that autophagy serves as a survival mechanism in response to cryptolepine treatment in L. donovani promastigotes and inhibition of autophagy causes an early increase in the amount of cell death. This study can be exploited for designing better drugs and better therapeutic strategies against leishmaniasis in future. PMID:22091398

  17. Leishmania Promastigotes Lack Phosphatidylserine but Bind Annexin V upon Permeabilization or Miltefosine Treatment

    PubMed Central

    Zampieri, Ricardo Andrade; Gonzaga dos Santos, Marcos; Schiller, Jürgen; Pomorski, Thomas Günther

    2012-01-01

    The protozoan parasite Leishmania is an intracellular pathogen infecting and replicating inside vertebrate host macrophages. A recent model suggests that promastigote and amastigote forms of the parasite mimic mammalian apoptotic cells by exposing phosphatidylserine (PS) at the cell surface to trigger their phagocytic uptake into host macrophages. PS presentation at the cell surface is typically analyzed using fluorescence-labeled annexin V. Here we show that Leishmania promastigotes can be stained by fluorescence-labeled annexin V upon permeabilization or miltefosine treatment. However, combined lipid analysis by thin-layer chromatography, mass spectrometry and 31P nuclear magnetic resonance (NMR) spectroscopy revealed that Leishmania promastigotes lack any detectable amount of PS. Instead, we identified several other phospholipid classes such phosphatidic acid, phosphatidylethanolamine; phosphatidylglycerol and phosphatidylinositol as candidate lipids enabling annexin V staining. PMID:22870283

  18. Effect of allicin on promastigotes and intracellular amastigotes of Leishmania donovani and L. infantum.

    PubMed

    Jesús Corral-Caridad, María; Moreno, Inmaculada; Toraño, Alfredo; Domínguez, Mercedes; Alunda, José María

    2012-12-01

    Anti-leishmanial activity of allicin (=diallyl thiosulphinate) has been tested in vitro against promastigotes and intracellular amastigotes of Leishmania donovani and Leishmania infantum. Macrophage infections have been carried out in vitro in the murine cell line J774 and ex vivo with peritoneal macrophages from BALB/c mice with a modified method to isolate metacyclic promastigotes. The compound has shown a significant in vitro effect on the multiplication of promastigotes of L. donovani and L. infantum in a time- and dose-dependent manner. It has been shown for the first time the inhibition of multiplication of intracellular amastigotes of Leishmania by allicin. Inhibitory concentrations of the compound were in the micromolar range (10-30 μM) for both Leishmania species. Antileishmanial effect of allicin apparently was not related to products of degradation of the molecule as assessed by mass spectrometry analysis. Inhibitory activity of allicin against promastigotes and intracellular amastigotes increased when the compound was added to the cultures every 24 h. Two administrations of 5 μM allicin inhibited by ca. 50% the proliferation of Leishmania amastigotes. Low toxicity for mammalian cells of this compound suggests the interest of exploring the value of allicin in combined therapy against leishmanial infections.

  19. An in vitro study of apoptotic like death in Leishmania donovani promastigotes by withanolides.

    PubMed

    Chandrasekaran, Sambamurthy; Dayakar, Alti; Veronica, Jalaja; Sundar, Shyam; Maurya, Radheshyam

    2013-06-01

    The aim of this study was to isolate and evaluate the withanolides in inducing apoptotic like death in Leishmania donovani in vitro. Withanolides were fractionated and isolated from the leaves of Withania somnifera and LC-MS/MS analysis of two fractions namely, F5 and F6 of ethanolic extracts, obtained through column chromatography with silica gel, was performed. The antileishmanial effect of withanolides on L. donovani promastigotes was assessed in vitro using PI dye exclusion test. The effect of withanolides on promastigote morphology was determined by scanning electron microscopy. To understand their mode of action against L. donovani, DNA fragmentation, quantification of parasites at sub G0/G1 phase, determination of phosphatidylserine externalization, measurement of reactive oxygen species (ROS) and mitochondrial membrane potential (Ψm) were done. Results showed that LC-MS/MS analysis confirmed the presence of withanolides in isolated fractions. Treatment with withanolides resulted in morphological alterations from spindle to round shape and loss of flagella/cell integrity in promastigotes. Moreover, it induced DNA nicks, cell cycle arrest at sub G0/G1 phase and externalization of phosphatidylserine in dose and time dependent manner via increase in ROS and decrease in Ψm. Results of this study indicate that withanolides induce apoptotic like death through the production of ROS from mitochondria and disruption of Ψm in promastigotes of L donovani.

  20. Leishmania donovani promastigotes evade the antimicrobial activity of neutrophil extracellular traps.

    PubMed

    Gabriel, Christelle; McMaster, W Robert; Girard, Denis; Descoteaux, Albert

    2010-10-01

    Upon their recruitment to a site of infection and their subsequent activation, neutrophils release DNA and a subset of their granule content to form filamentous structures, known as neutrophil extracellular traps, which capture and kill microorganisms. In this study, we show that Leishmania promastigotes induced the rapid release of neutrophil extracellular traps from human neutrophils and were trapped by these structures. The use of Leishmania mutants defective in the biosynthesis of either lipophosphoglycan or GP63 revealed that these two major surface promastigote virulence determinants were not responsible for inducing the release of the surface protease neutrophil extracellular traps. We also demonstrate that this induction was independent of superoxide production by neutrophils. Finally, in contrast to wild-type Leishmania donovani promastigotes, mutants defective in lipophosphoglycan biosynthesis were highly susceptible to the antimicrobial activity of neutrophil extracellular traps. Altogether, our data suggest that neutrophil extracellular traps may contribute to the containment of L. donovani promastigotes at the site of inoculation, thereby facilitating their uptake by mononuclear phagocytes.

  1. Stachytarpheta cayennensis extract inhibits promastigote and amastigote growth in Leishmania amazonensis via parasite arginase inhibition.

    PubMed

    Maquiaveli, Claudia do Carmo; Oliveira E Sá, Amanda Maria; Vieira, Paulo Cezar; da Silva, Edson Roberto

    2016-11-04

    Stachytarpheta cayennensis is a plant that is traditionally used to treat tegumentary leishmaniasis and as an anti-inflammatory agent. This study aimed to evaluate the action of S. cayennensis extracts on the Leishmania (Leishmania) amazonensis arginase enzyme. S. cayennensis was collected from the Brazilian Amazon region. Aqueous extracts were fractionated with n-butanol. The leishmanicidal effects of the n-butanolic fraction (BUF) were evaluated in L. (L.) amazonensis promastigotes and amastigotes. BUF was tested against recombinant arginase from both L. (L.) amazonensis and macrophage arginase. Promastigote cultures and infected macrophage cultures were supplemented with L-ornithine to verify arginase inhibition. NMR analysis was used to identify the major components of BUF. BUF showed an EC50 of 51 and 32µg/mL against promastigotes and amastigotes of L. (L.) amazonensis, respectively. BUF contains a mixture of verbascoside and isoverbascoside (7:3 ratio) and is a potent L. (L.) amazonensis arginase inhibitor (IC50=1.2µg/mL), while macrophage arginase was weakly inhibited (IC50>1000µg/mL). The inhibition of arginase by BUF in promastigotes and amastigotes could be demonstrated by culture media supplementation with L-ornithine, a product of the hydrolysis of L-arginine by arginase. Leishmanicidal effects of the S. cayennensis BUF fraction on L. (L.) amazonensis are associated with selective parasite arginase inhibition. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  2. Photodynamic activity of aluminium (III) and zinc (II) phthalocyanines in Leishmania promastigotes.

    PubMed

    Escobar, Patricia; Hernández, Indira P; Rueda, Cesar M; Martínez, Fernando; Páez, Edgar

    2006-10-01

    Photodynamic therapy is a two-step procedure, involving the use of photosensitizing agents followed by selective illumination of the target lesion with visible light. It produces highly reactive oxygen species and subsequent cellular damage. This study was designed to determine whether Leishmania chagasi and L. panamensis promastigotes were sensitive to photodynamic therapy in vitro. Leishmania promastigotes were treated with aluminium phthalocyanine chloride and zinc phthalocyanine photosensitizers before illumination with visible light at 670 nm. The parasite photoactivity was calculated by sigmoidal regression analysis. Leishmania chagasi promastigotes were highly photosensitive to aluminium phthalocyanine chloride treatment with effective inhibitory dose50 (ED50) concentration values of 0.0033, 0.0083 and 0.0093 microM upon exposure to 10.0, 5.0, and 2.5 J/cm2 light intensities respectively. By contrast, the activity of aluminium phthalocyanine chloride on L. panamensis was significantly lower (P < 0.01) with ED50 values of 0.17, 0.25, 0.34 microM at the same light intensities. Zinc phthalocyanine activity was significantly (P < 0.01) less active than aluminium phthalocyanine chloride on both strains of these two species and no differences in zinc phthalocyanine activity were found between them. A dose-response phototoxic effect with both phthalocyanines was observed. Parasite inhibition was not observed after aluminium phthalocyanine chloride or zinc phthalocyanine treatment in the dark. The reference drugs hexadecylphosphocholine and amphotericin B were not photoactive. Treatment of Leishmania promastigotes with aluminium phthalocyanine chloride and zinc phthalocyanine followed by illumination with visible light at 670 nm inhibited in vitro growth of promastigotes of L. chagasi and L. panamensis. Photodynamic therapy against Leishmania could be a promising strategy for leishmaniasis treatment.

  3. Antiproliferative and ultrastructural effects of phenethylamine derivatives on promastigotes and amastigotes of Leishmania (Leishmania) infantum chagasi.

    PubMed

    Brasil, Paula Ferreira; de Freitas, Júlia Araújo; Barreto, Anna Léa Silva; Adade, Camila Marques; Reis de Sá, Leandro Figueira; Constantino-Teles, Pamella; Toledo, Fabiano Travanca; de Sousa, Bruno A; Gonçalves, Augusto Cesar; Romanos, Maria Teresa Villela; Comasseto, João V; Dos Santos, Alcindo A; Tessis, Ana Claudia; Souto-Padrón, Thais; Soares, Rosangela Maria A; Ferreira-Pereira, Antonio

    2017-04-01

    Leishmania (Leishmania) infantum chagasi is one of the agents that cause visceral leishmaniasis. This disease occurs more frequently in third world countries, such as Brazil. The treatment is arduous, and is dependent on just a few drugs like the antimonial derivatives and amphotericin B. Moreover, these drugs are not only expensive, but they can also cause severe side effects and require long-term treatment. Therefore, it is very important to find new compounds that are effective against leishmaniasis. In the present work we evaluated a new group of synthetic amides against the promastigote and amastigote forms of L. infantum chagasi. The results showed that one of these amides in particular, presented very effective activity against the promastigotes and amastigotes of L. infantum chagasi at low concentrations and it also presented low toxicity for mammal cells, which makes this synthetic amide a promising drug for combating leishmaniasis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  4. Leishmania major Promastigotes Evade LC3-Associated Phagocytosis through the Action of GP63

    PubMed Central

    Matte, Christine; Casgrain, Pierre-André; Séguin, Olivier; Moradin, Neda; Hong, Wan Jin; Descoteaux, Albert

    2016-01-01

    The protozoan Leishmania parasitizes macrophages and evades the microbicidal consequences of phagocytosis through the inhibition of phagolysosome biogenesis. In this study, we investigated the impact of this parasite on LC3-associated phagocytosis, a non-canonical autophagic process that enhances phagosome maturation and functions. We show that whereas internalization of L. major promastigotes by macrophages promoted LC3 lipidation, recruitment of LC3 to phagosomes was inhibited through the action of the parasite surface metalloprotease GP63. Reactive oxygen species generated by the NOX2 NADPH oxidase are necessary for LC3-associated phagocytosis. We found that L. major promastigotes prevented, in a GP63-dependent manner, the recruitment of NOX2 to phagosomes through a mechanism that does not involve NOX2 cleavage. Moreover, we found that the SNARE protein VAMP8, which regulates phagosomal assembly of the NADPH oxidase NOX2, was down-modulated by GP63. In the absence of VAMP8, recruitment of LC3 to phagosomes containing GP63-deficient parasites was inhibited, indicating that VAMP8 is involved in the phagosomal recruitment of LC3. These findings reveal a role for VAMP8 in LC3-associated phagocytosis and highlight a novel mechanism exploited by L. major promastigotes to interfere with the host antimicrobial machinery. PMID:27280768

  5. Leishmania pifanoi: kinetics of messenger RNA expression during amastigote to promastigote transformation in vitro.

    PubMed

    Campbell, S M; Rainey, P M

    1993-08-01

    Conditions have been developed which induce axenically grown Leishmania pifanoi amastigotes to transform into the promastigote stage in a highly reproducible fashion. Transformation was induced by a temperature shift from 31 to 22 degrees C, was inhibited by high cell concentration (> or = 40 x 10(6) cells/ml), and was unaffected by pH from 5.5-7.2. Morphologic transformation was first evident at 8 hr after induction, had occurred in > 50% of cells by 24 hr, and was > 90% complete by 48 hr. This system enabled study of the kinetics of mRNA expression during the transformation of Leishmania. The differentially expressed mRNAs for ATPase 1a and 1b, alpha- and beta-tubulin, P100/11E, Pro-1, and pLm 2, 7, 14, and 16 exhibited complex patterns of temporal expression, suggesting a highly regulated process. Differentiation on the biochemical level was evident within an hour and continued throughout the course of morphologic transformation. In addition, transformed L. pifanoi promastigotes in the plateau growth phase expressed genes characteristic of metacyclic promastigotes. Axenically cultured L. pifanoi should provide an excellent model for the study of differentiation in Leishmania.

  6. Ultrastructural Analysis of Leishmania infantum chagasi Promastigotes Forms Treated In Vitro with Usnic Acid

    PubMed Central

    da Luz, João S. B.; de Oliveira, Erwelly B.; Martins, Monica C. B.; da Silva, Nicácio H.; Alves, Luiz C.; dos Santos, Fábio A. B.; da Silva, Luiz L. S.; Silva, Eliete C.; de Medeiros, Paloma L.

    2015-01-01

    Leishmaniasis is considered by the World Health Organization as one of the infectious parasitic diseases endemic of great relevance and a global public health problem. Pentavalent antimonials used for treatment of this disease are limited and new phytochemicals emerge as an alternative to existing treatments, due to the low toxicity and cost reduction. Usnic acid is uniquely found in lichens and is especially abundant in genera such as Alectoria, Cladonia, Evernia, Lecanora, Ramalina, and Usnea. Usnic acid has been shown to exhibit antiviral, antiprotozoal, antiproliferative, anti-inflammatory, and analgesic activity. The aim of this study was to evaluate the antileishmanial activity of usnic acid on Leishmania infantum chagasi promastigotes and the occurrence of drug-induced ultrastructural damage in the parasite. Usnic acid was effective against the promastigote forms (IC50 = 18.30 ± 2.00 µg/mL). Structural and ultrastructural aspects of parasite were analyzed. Morphological alterations were observed as blebs in cell membrane and shapes given off, increasing the number of cytoplasmic vacuoles, and cellular and mitochondrial swelling, with loss of cell polarity. We concluded that the usnic acid presented antileishmanial activity against promastigote forms of Leishmania infantum chagasi and structural and ultrastructural analysis reinforces its cytotoxicity. Further, in vitro studies are warranted to further evaluate this potential. PMID:25767824

  7. Genomic and proteomic expression analysis of Leishmania promastigote and amastigote life stages: the Leishmania genome is constitutively expressed.

    PubMed

    Leifso, Kirk; Cohen-Freue, Gabriela; Dogra, Nisha; Murray, Angus; McMaster, W Robert

    2007-03-01

    Leishmania are protozoan parasites that cause a wide spectrum of clinical diseases in humans and are a major public health risk in several countries. Leishmania life cycle consists of an extracellular flagellated promastigote stage within the midgut of a sandfly vector, and a morphological distinct intracellular amastigote stage within macrophages of a mammalian host. This study reports the use of DNA oligonucleotide genome microarrays representing 8160 genes to analyze the mRNA expression profiles of L. major promastigotes and lesion derived amastigotes. Over 94% of the genes were expressed in both life stages. Advanced statistical analysis identified a surprisingly low degree of differential mRNA expression: 1.4% of the total genes in amastigotes and 1.5% in promastigotes. These microarray results demonstrate that the L. major genome is essentially constitutively expressed in both life stages and suggest that Leishmania is constitutively adapted for survival and replication in either the sandfly vector or macrophage host utilizing an appropriate set of genes for each vastly different environment. Quantitative proteomics, using the isotope coded affinity tag (ICAT) technology and mass spectrometry, was used to identify L. infantum promastigote and axenic amastigote differentially expressed proteins. Of the 91 distinct proteins identified, 8% were differentially expressed in the amastigote stage, 20% were differentially expressed in the promastigote stage, and the remaining 72% were considered constitutively expressed. The differential expression was validated by the identification of previously reported stage specific proteins and identified several amastigote and promastigote novel stage specific proteins.

  8. Leishmania amazonensis Promastigotes Present Two Distinct Modes of Nucleus and Kinetoplast Segregation during Cell Cycle

    PubMed Central

    da Silva, Marcelo Santos; Monteiro, Jomar Patrício; Nunes, Vinícius Santana; Vasconcelos, Elton José; Perez, Arina Marina; Freitas-Júnior, Lúcio de Holanda; Elias, Maria Carolina; Cano, Maria Isabel Nogueira

    2013-01-01

    Here, we show the morphological events associated with organelle segregation and their timing in the cell cycle of a reference strain of Leishmania (L.) amazonensis promastigotes, the main causative agent of Tegumentary leishmaniasis in the Americas. We show evidences that during the cell cycle, L. amazonensis promastigotes present two distinct modes of nucleus and kinetoplast segregation, which occur in different temporal order in different proportions of cells. We used DAPI-staining and EdU-labeling to monitor the segregation of DNA-containing organelles and DNA replication in wild-type parasites. The emergence of a new flagellum was observed using a specific monoclonal antibody. The results show that L. amazonensis cell cycle division is peculiar, with 65% of the dividing cells duplicating the kinetoplast before the nucleus, and the remaining 35% doing the opposite or duplicating both organelles concomitantly. In both cases, the new flagellum appeared during S to G2 phase in 1N1K cells and thus before the segregation of both DNA-containing organelles; however, we could not determine the exact timing of flagellar synthesis. Most of these results were confirmed by the synchronization of parasites using hydroxyurea. Altogether, our data show that during the cell cycle of L. amazonensis promastigotes, similarly to L. donovani, the segregation of nucleus and kinetoplast do not follow a specific order, especially when compared to other trypanosomatids, reinforcing the idea that this characteristic seems to be species-specific and may represent differences in cellular biology among members of the Leishmania genus. PMID:24278433

  9. Leishmania donovani lacking the Golgi GDP-Man transporter LPG2 exhibit attenuated virulence in mammalian hosts.

    PubMed

    Gaur, Upasna; Showalter, Melissa; Hickerson, Suzanne; Dalvi, Rahul; Turco, Salvatore J; Wilson, Mary E; Beverley, Stephen M

    2009-07-01

    Surface phosophoglycans such as lipophosphoglycan (LPG) or proteophosphoglycan (PPG) and glycosylinositol phospholipids (GIPLs) modulate essential interactions between Leishmania and mammalian macrophages. Phosphoglycan synthesis depends on the Golgi GDP-mannose transporter encoded by LPG2. LPG2-null (lpg2(-)) Leishmania major cannot establish macrophage infections or induce acute pathology, whereas lpg2(-)Leishmania mexicana retain virulence. lpg2(-)Leishmania donovani has been reported to survive poorly in cultured macrophages but in vivo survival has not been explored. Herein we discovered that, similar to lpg2(-)L. major, lpg2(-)L. donovani promastigotes exhibited diminished virulence in mice, but persisted at consistently low levels. lpg2(-)L. donovani promastigotes could not establish infection in macrophages and could not transiently inhibit phagolysosomal fusion. Furthermore, lpg2(-) promastigotes of L. major, L. donovani and L. mexicana were highly susceptible to complement-mediated lysis. We conclude that phosphoglycan assembly and expression mediated by L. donovani LPG2 are important for promastigote and amastigote virulence, unlike L. mexicana but similar to L. major.

  10. Leishmania donovani lacking the Golgi GDP-Man transporter LPG2 exhibit attenuated virulence in mammalian hosts

    PubMed Central

    Gaur, Upasna; Showalter, Melissa; Hickerson, Suzanne; Dalvi, Rahul; Turco, Salvatore J.; Wilson, Mary E.; Beverley, Stephen M.

    2009-01-01

    Surface phosophoglycans such as lipophosphoglycan (LPG) or proteophosphoglycan (PPG) and glycosylinositol phospholipids (GIPLs) modulate essential interactions between Leishmania and mammalian macrophages. Phosphoglycan synthesis depends on the Golgi GDP-mannose transporter encoded by LPG2. LPG2-null (lpg2−) L. major cannot establish macrophage infections or induce acute pathology, whereas lpg2− L. mexicana retain virulence. lpg2− L. donovani has been reported to survive poorly in cultured macrophages but in vivo survival has not been explored. Herein we discovered that, similar to lpg2− L. major, lpg2− L. donovani promastigotes exhibited diminished virulence in mice, but persisted at consistently low levels. lpg2− L. donovani promastigotes could not establish infections macrophages and could not transiently inhibit phagolysosomal fusion. Furthermore, lpg2− promastigotes of L. major, L. donovani and L. mexicana were highly susceptible to complement mediated lysis. We conclude that phosphoglycan assembly and expression mediated by L. donovani LPG2 are important for promastigote and amastigote virulence, unlike L. mexicana but similar to L. major. PMID:19328787

  11. Morphological and physiological changes in Leishmania promastigotes induced by yangambin, a lignan obtained from Ocotea duckei.

    PubMed

    Monte Neto, Rubens L; Sousa, Louisa M A; Dias, Celidarque S; Barbosa Filho, José M; Oliveira, Márcia R; Figueiredo, Regina C B Q

    2011-01-01

    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. Treated-parasites showed significant alterations in fluorescence emission pattern and cell morphology when compared with control cells, including the appearance of abnormal round-shaped cells, loss of cell motility, nuclear pyknosis, cytoplasm acidification and increased number of acidic vesicular organelles (AVOs), suggesting important physiological changes. Ultrastructural analysis of treated-promatigotes showed characteristics of cell death by apoptosis as well as by autophagy. The presence of parasites exhibiting multiples nuclei suggests that yangambin may also affect the microtubule dynamic in both Leishmania species. Taken together our results show that yangambin is a promising agent against Leishmania. Copyright © 2010 Elsevier Inc. All rights reserved.

  12. Purification and Characterization of a Novel Intracellular Sucrase Enzyme of Leishmania donovani Promastigotes.

    PubMed

    Singh, Arpita; Mandal, Debjani

    2016-01-01

    The promastigote stage of Leishmania resides in the sand fly gut, enriched with sugar molecules. Recently we reported that Leishmania donovani possesses a sucrose uptake system and a stable pool of intracellular sucrose metabolizing enzyme. In the present study, we purified the intracellular sucrase nearly to its homogeneity and compared it with the purified extracellular sucrase. The estimated size of intracellular sucrase is ~112 kDa by gel filtration chromatography, native PAGE, and substrate staining. However, in SDS-PAGE, the protein is resolved at ~56 kDa, indicating the possibility of a homodimer in its native state. The kinetics of purified intracellular sucrase shows its higher substrate affinity with a K m of 1.61 mM than the extracellular form having a K m of 4.4 mM. The highly specific activity of intracellular sucrase towards sucrose is optimal at pH 6.0 and at 30°C. In this report the purification and characterization of intracellular sucrase provide evidence that sucrase enzyme exists at least in two different forms in Leishmania donovani promastigotes. This intracellular sucrase may support further intracellular utilization of transported sucrose.

  13. Purification and Characterization of a Novel Intracellular Sucrase Enzyme of Leishmania donovani Promastigotes

    PubMed Central

    Singh, Arpita; Mandal, Debjani

    2016-01-01

    The promastigote stage of Leishmania resides in the sand fly gut, enriched with sugar molecules. Recently we reported that Leishmania donovani possesses a sucrose uptake system and a stable pool of intracellular sucrose metabolizing enzyme. In the present study, we purified the intracellular sucrase nearly to its homogeneity and compared it with the purified extracellular sucrase. The estimated size of intracellular sucrase is ~112 kDa by gel filtration chromatography, native PAGE, and substrate staining. However, in SDS-PAGE, the protein is resolved at ~56 kDa, indicating the possibility of a homodimer in its native state. The kinetics of purified intracellular sucrase shows its higher substrate affinity with a K m of 1.61 mM than the extracellular form having a K m of 4.4 mM. The highly specific activity of intracellular sucrase towards sucrose is optimal at pH 6.0 and at 30°C. In this report the purification and characterization of intracellular sucrase provide evidence that sucrase enzyme exists at least in two different forms in Leishmania donovani promastigotes. This intracellular sucrase may support further intracellular utilization of transported sucrose. PMID:27190649

  14. Arginase Is Essential for Survival of Leishmania donovani Promastigotes but Not Intracellular Amastigotes

    PubMed Central

    Boitz, Jan M.; Gilroy, Caslin A.; Olenyik, Tamara D.; Paradis, Dustin; Perdeh, Jasmine; Dearman, Kristie; Davis, Madison J.; Yates, Phillip A.; Li, Yuexin; Riscoe, Michael K.; Ullman, Buddy

    2016-01-01

    ABSTRACT Studies of Leishmania donovani have shown that both ornithine decarboxylase and spermidine synthase, two enzymes of the polyamine biosynthetic pathway, are critical for promastigote proliferation and required for maximum infection in mice. However, the importance of arginase (ARG), the first enzyme of the polyamine pathway in Leishmania, has not been analyzed in L. donovani. To test ARG function in intact parasites, we generated Δarg null mutants in L. donovani and evaluated their ability to proliferate in vitro and trigger infections in mice. The Δarg knockout was incapable of growth in the absence of polyamine supplementation, but the auxotrophic phenotype could be bypassed by addition of either millimolar concentrations of ornithine or micromolar concentrations of putrescine or by complementation with either glycosomal or cytosolic versions of ARG. Spermidine supplementation of the medium did not circumvent the polyamine auxotrophy of the Δarg line. Although ARG was found to be essential for ornithine and polyamine synthesis, ornithine decarboxylase appeared to be the rate-limiting enzyme for polyamine production. Mouse infectivity studies revealed that the Δarg lesion reduced parasite burdens in livers by an order of magnitude but had little impact on the numbers of parasites recovered from spleens. Thus, ARG is essential for proliferation of promastigotes but not intracellular amastigotes. Coupled with previous studies, these data support a model in which L. donovani amastigotes readily salvage ornithine and have some access to host spermidine pools, while host putrescine appears to be unavailable for salvage by the parasite. PMID:27795357

  15. Intracellular pH homeostasis in Leishmania donovani amastigotes and promastigotes

    SciTech Connect

    Glaser, T.A.; Baatz, J.E.; Kreishman, G.P.; Mukkada, A.J. )

    1988-10-01

    Intracellular pH and pH gradients of Leishmania donovani amastigotes and promastigotes were determined over a broad range of extracellular pH values. Intracellular pH was determined by {sup 31}P NMR and by equilibrium distribution studies with 5,5-dimethyloxazolidine-2,4-dione or methylamine. Promastigotes maintain intracellular pH values close to neutral between extracellular pH values of 5.0 and 7.4. Amastigote intracellular pH is maintained close to neutral at external pH values as low as 4.0. Both life stages maintain a positive pH gradient to an extracellular pH of 7.4, which is important for active transport of substrates. Treatment with ionophores, such as nigericin and carbonyl cyanide m-chlorophenylhydrazone and the ATPase inhibitor dicyclohexylcarbodiimide, reduced pH gradients in both stages. Maintenance of intracellular pH in the physiologic range is especially relevant for the survival of the amastigote in its acidic in vivo environment.

  16. Responses of European green lizards Lacerta viridis following administration of Leishmania agamae promastigotes.

    PubMed

    Ingram, G A; Molyneux, D H

    1984-12-01

    European green lizards (Lacerta viridis) were injected intraperitoneally, subcutaneously or orally with viable Leishmania agamae promastigotes. Neither promastigotes nor amastigotes were later found in blood and tissue impression smears, or in blood and selected organ cultures. However, by the use of an immunoperoxidase technique, parasite antigens were detected in the liver, stomach, small intestine, kidney, gonad, heart, lung and skin but not in the bone marrow, brain or spleen. Non-precipitating antibodies with beta 2-electrophoretic mobility were induced against L. agamae. They were detected in the sera by enzyme-linked immunosorbent assay 3-7 days post-infection. The titres increased significantly above background levels (P less than 0.001) and reached maxima after 6-7 weeks, with 27 out of 29 lizards producing antibodies. The mean serum protein concentration significantly increased after infection (P less than 0.005) with no significant differences in mean values between male and female animals. Lizard sera separated into 7 components on cellulose acetate membranes with migration rates comparable to albumin, alpha- and beta-globulins of human serum; gamma-globulins were absent. Significant decreases occurred (P less than 0.05) in the albumin fraction, with significant increases in the beta-globulin region of anti-L. agamae sera. C-reactive protein was not detected in either normal or immune lizard sera.

  17. Innovative serum-free medium for in vitro cultivation of promastigote forms of Leishmania species.

    PubMed

    Sharief, Abdalla Hassan; Khalil, Eltahir Awad Gasim; Omer, Samia Ali; Abdalla, Hamid Sulaiman

    2008-06-01

    We described a comparatively simple medium formula (CML) using common, available and reasonably priced ingredients that could be used in place of medium that requires calf serum enhancement for cultivation of Leishmania promastigote forms. This medium equivalently supported the growth of parasites at rates comparable with those obtained with serum supplemented RPMI-1640 medium. Leishmania promastigotes reproduced in CML exhibited moderate to high infectivity capacities when tested against J774 macrophage cell line. No significant difference was noted between Leishmania strains cultivated in the newly modified medium and those grown in RPMI-1640 medium in their cells infectivity and replication potentials. The use of new CML can easily take the place of other biphasic or liquid media because of its easy preparation and instantaneous use, reasonable price, availability of ingredients, and its long shelf life, which is 30-45 days. The fact that this medium is similar to other culture media as far as durability and quantity of produced parasites might give it an advantage over the other currently used media.

  18. Los Sentimientos, Luchas, y Esperanzas de Cinco Familias Mexicana: The Sentiments, Struggles, and Hopes of Five Mexican Families

    ERIC Educational Resources Information Center

    Dueñas, Gilbert

    2015-01-01

    Within the everyday space of their modest trailer homes, I observed compelling environments in the households of 5 Mexican families. In their homes, there existed "los padres con sus hijos" (parents with their children) who intuitively expressed "cariño," or love, for one another, conversed in multiple languages, practiced…

  19. Latina/o or Mexicana/o?: The Relationship between Socially Assigned Race and Experiences with Discrimination

    PubMed Central

    Vargas, Edward D.; Winston, Nadia C.; Garcia, John A.; Sanchez, Gabriel R.

    2016-01-01

    Discrimination based on one’s racial or ethnic background is one of the oldest and most perverse practices in the United States. While much of this research has relied on self-reported racial categories, a growing body of research is attempting to measure race through socially-assigned race. Socially-assigned or ascribed race measures how individuals feel they are classified by other people. This paper draws on the socially assigned race literature and explores the impact of socially assigned race on experiences with discrimination using a 2011 nationally representative sample of Latina/os (n=1,200). While much of the current research on Latina/os has been focused on the aggregation across national origin group members, this paper marks a deviation by using socially-assigned race and national origin to understand how being ascribed as Mexican is associated with experiences of discrimination. We find evidence that being ascribed as Mexican increases the likelihood of experiencing discrimination relative to being ascribed as White or Latina/o. Furthermore, we find that being miss-classified as Mexican (ascribed as Mexican, but not of Mexican origin) is associated with a higher likelihood of experiencing discrimination compared to being ascribed as white, ascribed as Latina/o, and correctly ascribed as Mexican. We provide evidence that socially assigned race is a valuable complement to self-identified race/ethnicity for scholars interested in assessing the impact of race/ethnicity on a wide range of outcomes. PMID:27709119

  20. Anatomy and projection patterns of the superior olivary complex in the Mexican free-tailed bat, Tadarida brasiliensis mexicana.

    PubMed

    Grothe, B; Schweizer, H; Pollak, G D; Schuller, G; Rosemann, C

    1994-05-22

    The superior olivary complex (SOC) is the first station in the ascending auditory pathway that receives binaural projections. Two of the principal nuclei, the lateral superior olive (LSO) and the medial superior olive (MSO), are major sources of ascending projections to the inferior colliculus. Whereas almost all mammals have an LSO, it has traditionally been thought that only animals that hear low frequencies have an MSO. Recent reports, however, suggest that the medial part of the SOC in bats is highly variable and that at least some bats have a well-developed MSO. Thus, the main goal of this study was to evaluate the cytoarchitecture and connections of the principal superior olivary nuclei of the Mexican free-tailed bat, with specific attention directed at the MSO. Cell and fiber stained material revealed that the LSO and the medial nucleus of the trapezoid body (MNTB) are similar to those described for other mammals. There are two medial nuclei we refer to as dorsomedial periolivary nucleus (DMPO) and MSO. Tracer experiments exhibited that the DMPO receives bilateral projections from the cochlear nucleus, and additional projections from the ipsilateral MNTB. The DMPO sends a strong projection to the ipsilateral inferior colliculus. Positive staining for acetylcholinesterase indicates that the DMPO is a part of the olivocochlear system, as it is in other animals. The MSO in the free-tailed bat meets many of the criteria that traditionally define this nucleus. These include the presence of bipolar and multipolar principal cells, bilateral innervation from the cochlear nucleus, a strong projection from the ipsilateral MNTB, and the absence of cholinergic cells. The major difference from traditional MSO features is that it projects bilaterally to the inferior colliculus. Approximately 30% of its cells provide collateral projections to the colliculi on both sides. Functional implications of the MSO for the free-tailed bat are considered in the Discussion.

  1. Our Treasures: A Celebration of Nebraska's Mexican Heritage = Nuestros Tesoros: Una celebracion de la herencia mexicana de Nebraska.

    ERIC Educational Resources Information Center

    Nebraska State Historical Society, Lincoln.

    This publication is intended as a resource guide for teachers, students, and librarians interested in Mexican American culture, and for groups wishing to conduct local community research using oral histories. The Mexican American Traditions in Nebraska project was designed to document and preserve the richness of Nebraska's Mexican culture. The…

  2. Seeking a "Mexicana/Mestiza" Critical Feminist Ethic of Care: Diana's "Revolución" of Body and Being

    ERIC Educational Resources Information Center

    Sosa-Provencio, Mia Angélica

    2016-01-01

    This Chicana Critical Feminist Testimonio reveals a Mexican/Mexican-American Ethic of Care and Testimonios of struggle and survival informing curriculum and pedagogy of one Mexican/Mexican-American female educator of predominantly Mexican/Mexican-American students. This work is part of a larger ethnographic study conducted through multiple…

  3. Seeking a "Mexicana/Mestiza" Critical Feminist Ethic of Care: Diana's "Revolución" of Body and Being

    ERIC Educational Resources Information Center

    Sosa-Provencio, Mia Angélica

    2016-01-01

    This Chicana Critical Feminist Testimonio reveals a Mexican/Mexican-American Ethic of Care and Testimonios of struggle and survival informing curriculum and pedagogy of one Mexican/Mexican-American female educator of predominantly Mexican/Mexican-American students. This work is part of a larger ethnographic study conducted through multiple…

  4. Presence of Putative Male-Produced Sex Pheromone in Lutzomyia cruciata (Diptera: Psychodidae), Vector of Leishmania mexicana.

    PubMed

    Serrano, A K; Rojas, J C; Cruz-López, L C; Malo, Edi A; Mikery, O F; Castillo, A

    2016-11-01

    Lutzomyia cruciata (Coquillet) is a vector of cutaneous leishmaniasis in Mexico and Central America. However, several aspects of its ecology and behavior are unknown, including whether a male pheromone partially mediates the sexual behavior of this sand fly. In this study, we evaluated the behavioral response of females to male abdominal extracts in a Y-tube olfactometer. The volatile compounds from male abdominal extracts were identified by gas chromatography-mass spectrometry and compared with those of female abdominal extracts. Finally, the disseminating structures of the putative sex pheromone were examined by scanning electron microscopy in the male abdomen. Females were more attracted to male abdominal extract than to the hexane control, suggesting the presence of male-produced sex pheromone. The male abdominal extracts were characterized by the presence of 12 sesquiterpene compounds. The major component, an unknown sesquiterpene with an abundance of 60%, had a mass spectrum with molecular ion of m/z 262. In contrast, the abdominal female extracts contained saturated fatty acids. Finally, we detected the presence of small "papules" with a mammiform morphology distributed on the abdominal surface of tergites IV-VII of male Lu. cruciata These structures are not present in females. We conclude that Lu. cruciata males likely produce a pheromone involved in attracting or courting females. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Digestive strategies and food choice in mantled howler monkeys Alouatta palliata mexicana: bases of their dietary flexibility.

    PubMed

    Espinosa-Gómez, Fabiola; Gómez-Rosales, Sergio; Wallis, Ian R; Canales-Espinosa, Domingo; Hernández-Salazar, Laura

    2013-12-01

    Mantled howler monkeys (Alouatta palliata) occupy a wide variety of tropical habitats and are the most folivorous of New World primates. However, their diet may include fruits, buds, petioles, and flowers, as well as leaves, suggesting they must cope with variations in the nutrient composition of their food. We studied the physiological basis of the dietary flexibility of these monkeys by comparing food choice, digestive performance and patterns of digesta flow in six adults, fed diets of either leaves or a mixture of fruit and leaves. Although monkeys ate similar amounts of the two diets, they ingested more digestible protein when offered the leaf diet, on which they lost body mass, but they ingested much more soluble sugars when offered fruit and leaves on which they gained mass. Digestibilities of dry matter, fat, energy and fibre did not differ between diets, but those of crude protein, soluble sugars and minerals were higher on the fruit-leaf diet. Mean retention times in the gut of solute (Co-EDTA) and particulate markers (Cr-mordanted cell walls) did not differ between diets, but on both diets the monkeys retained the particulate marker (mean retention time ca 55 h) for longer than they did the solute marker (MRT ca 50 h). A lack of selective retention of solutes and small particles in the gastro-intestinal tract of howler monkeys probably restricts them to mixed diets but their digestive strategy is sufficiently flexible to allow them to feed on a diet of leaves when fruit is unavailable.

  6. Los Sentimientos, Luchas, y Esperanzas de Cinco Familias Mexicana: The Sentiments, Struggles, and Hopes of Five Mexican Families

    ERIC Educational Resources Information Center

    Dueñas, Gilbert

    2015-01-01

    Within the everyday space of their modest trailer homes, I observed compelling environments in the households of 5 Mexican families. In their homes, there existed "los padres con sus hijos" (parents with their children) who intuitively expressed "cariño," or love, for one another, conversed in multiple languages, practiced…

  7. Leishmania amazonensis promastigotes in 3D Collagen I culture: an in vitro physiological environment for the study of extracellular matrix and host cell interactions.

    PubMed

    Petropolis, Debora B; Rodrigues, Juliany C F; Viana, Nathan B; Pontes, Bruno; Pereira, Camila F A; Silva-Filho, Fernando C

    2014-01-01

    Leishmania amazonensis is the causative agent of American cutaneous leishmaniasis, an important neglected tropical disease. Once Leishmania amazonensis is inoculated into the human host, promastigotes are exposed to the extracellular matrix (ECM) of the dermis. However, little is known about the interaction between the ECM and Leishmania promastigotes. In this study we established L. amazonensis promastigote culture in a three-dimensional (3D) environment mainly composed of Collagen I (COL I). This 3D culture recreates in vitro some aspects of the human host infection site, enabling the study of the interaction mechanisms of L. amazonensis with the host ECM. Promastigotes exhibited "freeze and run" migration in the 3D COL I matrix, which is completely different from the conventional in vitro swimming mode of migration. Moreover, L. amazonensis promastigotes were able to invade, migrate inside, and remodel the 3D COL I matrix. Promastigote trans-matrix invasion and the freeze and run migration mode were also observed when macrophages were present in the matrix. At least two classes of proteases, metallo- and cysteine proteases, are involved in the 3D COL I matrix degradation caused by Leishmania. Treatment with a mixture of protease inhibitors significantly reduced promastigote invasion and migration through this matrix. Together our results demonstrate that L. amazonensis promastigotes release proteases and actively remodel their 3D environment, facilitating their migration. This raises the possibility that promastigotes actively interact with their 3D environment during the search for their cellular "home"-macrophages. Supporting this hypothesis, promastigotes migrated faster than macrophages in a novel 3D co-culture model.

  8. Leishmania amazonensis promastigotes in 3D Collagen I culture: an in vitro physiological environment for the study of extracellular matrix and host cell interactions

    PubMed Central

    Rodrigues, Juliany C.F.; Viana, Nathan B.; Pontes, Bruno; Pereira, Camila F.A.; Silva-Filho, Fernando C.

    2014-01-01

    Leishmania amazonensis is the causative agent of American cutaneous leishmaniasis, an important neglected tropical disease. Once Leishmania amazonensis is inoculated into the human host, promastigotes are exposed to the extracellular matrix (ECM) of the dermis. However, little is known about the interaction between the ECM and Leishmania promastigotes. In this study we established L. amazonensis promastigote culture in a three-dimensional (3D) environment mainly composed of Collagen I (COL I). This 3D culture recreates in vitro some aspects of the human host infection site, enabling the study of the interaction mechanisms of L. amazonensis with the host ECM. Promastigotes exhibited “freeze and run” migration in the 3D COL I matrix, which is completely different from the conventional in vitro swimming mode of migration. Moreover, L. amazonensis promastigotes were able to invade, migrate inside, and remodel the 3D COL I matrix. Promastigote trans-matrix invasion and the freeze and run migration mode were also observed when macrophages were present in the matrix. At least two classes of proteases, metallo- and cysteine proteases, are involved in the 3D COL I matrix degradation caused by Leishmania. Treatment with a mixture of protease inhibitors significantly reduced promastigote invasion and migration through this matrix. Together our results demonstrate that L. amazonensis promastigotes release proteases and actively remodel their 3D environment, facilitating their migration. This raises the possibility that promastigotes actively interact with their 3D environment during the search for their cellular “home”—macrophages. Supporting this hypothesis, promastigotes migrated faster than macrophages in a novel 3D co-culture model. PMID:24765565

  9. [Infectivity of promastigotes in stationary phase of Leishmania (viannia) braziliensis and leishmania (viannia) peruviana, In cell line dh82].

    PubMed

    Calvay-Sánchez, Karen Daphne; Rojas-Palomino, Nyshon Máximo; Sandoval-Juarez, Aidé Clorinda; Cisneros-Tarmeño, Alberto; Obregón-Cahuaya, Cristian; Minaya-Gómez, Gloria Sonia

    2015-01-01

    To determine the infectivity of promastigotes of Leishmania (V.) peruviana and Leishmania (V.) braziliensis in monocyte-macrophage cell line DH82 of Canis familiaris. Was conducted a experimental study during the months of january to december 2013. Were used strains of Leishmania were used (V.) braziliensis MHOM/PE/84/LC53 and Leishmania (V.) peruviana MHOM/PE/84/LC26. The cell line was infected with stationary phase promastigotes and infectivity was determined as the product of percent infected macrophages average amastigotes per macrophage observed in epifluorescence microscope. 13% of metacyclic forms to Leishmania (V.) braziliensis corresponded to 17.5 days post inoculation and Leishmania (V.) peruviana a percentage of 9.5% on the day 14.5. No significant difference was found between infectivity of stationary phase promastigotes of both species. It is recommended assess the infectivity of metacyclic promastigotes peruviana strains of Leishmania (V.) and Leishmania (V.) braziliensis cell lines in order to determine the most appropriate model in vitro infection, allowing leishmanicidas make the drug more effective susceptibility studies for disease control.

  10. In vivo and in vitro phagocytosis of Leishmania (Leishmania) amazonensis promastigotes by B-1 cells.

    PubMed

    Geraldo, M M; Costa, C R; Barbosa, F M C; Vivanco, B C; Gonzaga, W F K M; Novaes E Brito, R R; Popi, A F; Lopes, J D; Xander, P

    2016-06-01

    Leishmaniasis is caused by Leishmania parasites that infect several cell types. The promastigote stage of Leishmania is internalized by phagocytic cells and transformed into the obligate intracellular amastigote form. B-1 cells are a subpopulation of B cells that are able to differentiate in vitro and in vivo into mononuclear phagocyte-like cells with phagocytic properties. B-1 cells use several receptors for phagocytosis, such as the mannose receptor and third complement receptor. Leishmania binds to the same receptors on macrophages. In this study, we demonstrated that phagocytes derived from B-1 cells (B-1 CDP) were able to internalize promastigotes of L. (L.) amazonensis in vitro. The internalized promastigotes differentiated into amastigotes. Our results showed that the phagocytic index was higher in B-1 CDP compared to peritoneal macrophages and bone marrow-derived macrophages. The in vivo phagocytic ability of B-1 cells was also demonstrated. Parasites were detected inside purified B-1 cells after intraperitoneal infection with L. (L.) amazonensis promastigotes. Intraperitoneal stimulation with the parasites led to an increase in both IL-10 and TNF-α. These results highlight the importance of studying B-1 CDP cells as phagocytic cells that can participate and contribute to immunity to parasites. © 2016 John Wiley & Sons Ltd.

  11. Isoenzyme and ultrastructural characterization of Leishmania tropica axenic amastigotes and promastigotes.

    PubMed

    Hatam, Gholam Reza; Bahrami, Somayeh; Razavi, S Mostafa; Oryan, Ahmad

    2013-02-01

    Leishmania tropica is one of the main etiological agents of cutaneous leishmaniasis in Iran. For ultrastructural and isoenzyme study, axenic amastigotes were cultured in a brain-heart infusion medium containing 20 % fetal calf serum, pH 4.5, and incubated at 37 °C in 5 % CO(2). Different stages of L. tropica revealed the same isoenzyme profiles after comparing four enzyme systems including phosphoglucomutase, 6-phosphogluconate dehydrogenase, malate dehydrogenase, and nucleoside hydrolase II. Different isoenzyme patterns for glucose-phosphate isomerase, glucose-6-phosphate dehydrogenase, nucleoside hydrolase I, and malic enzyme enzymic systems were seen; thus, these isoenzyme systems among the eight systems studied were more efficient in characterizing L. tropica amastigotes. The structure of the axenic amastigotes was essentially similar to that of the promastigotes except for some important characteristics including the flagellum, flagellar pocket, paraxial rod, and the subpellicular microtubules.

  12. Effects of Sheep and Mouse Urine on the Growth Pattern of Leishmania major Promastigotes

    PubMed Central

    Karimi, Gholamreza; Dalimi, Abdolhossein; Paykari, Habibollah; Ghaffarifar, Fatemeh

    2013-01-01

    The protozoan parasites of the genus Leishmania are the causative agents of different clinical diseases. Fetal calf serum (FCS) is the main part and the most expensive ingredient of the Leishmania culture media. Here, the efficacies of different concentrations (1%, 2.5%, 5%, and 10%) of the filtered and autoclaved sheep and mouse urine were evaluated as a growth stimulator in Leishmania culture procedure. The results indicated that culture media enriched with the filtered sheep and mouse urine supported the growth of the parasites and can be used for cultivation of Leishmania parasites. In conclusion, this study has demonstrated an alternative low-cost medium that could be used in cultivation process of Leishmania major promastigotes. PMID:23957003

  13. The Calpain Inhibitor MDL28170 Induces the Expression of Apoptotic Markers in Leishmania amazonensis Promastigotes

    PubMed Central

    Marinho, Fernanda A.; Gonçalves, Keyla C. S.; Oliveira, Simone S. C.; Gonçalves, Diego S.; Matteoli, Filipe P.; Seabra, Sergio H.; Oliveira, Ana Carolina S.; Bellio, Maria; Oliveira, Selma S.; Souto-Padrón, Thaïs; d'Avila-Levy, Claudia M.; Santos, André L. S.; Branquinha, Marta H.

    2014-01-01

    Background Human cutaneous leishmaniasis is caused by distinct species, including Leishmania amazonensis. Treatment of cutaneous leishmaniasis is far from satisfactory due to increases in drug resistance and relapses, and toxicity of compounds to the host. As a consequence for this situation, the development of new leishmanicidal drugs and the search of new targets in the parasite biology are important goals. Methodology/Principal Findings In this study, we investigated the mechanism of death pathway induced by the calpain inhibitor MDL28170 on Leishmania amazonensis promastigote forms. The combined use of different techniques was applied to contemplate this goal. MDL28170 treatment with IC50 (15 µM) and two times the IC50 doses induced loss of parasite viability, as verified by resazurin assay, as well as depolarization of the mitochondrial membrane, which was quantified by JC-1 staining. Scanning and transmission electron microscopic images revealed drastic alterations on the parasite morphology, some of them resembling apoptotic-like death, including cell shrinking, surface membrane blebs and altered chromatin condensation pattern. The lipid rearrangement of the plasma membrane was detected by Annexin-V labeling. The inhibitor also induced a significant increase in the proportion of cells in the sub-G0/G1 phase, as quantified by propidium iodide staining, as well as genomic DNA fragmentation, detected by TUNEL assay. In cells treated with MDL28170 at two times the IC50 dose, it was also possible to observe an oligonucleossomal DNA fragmentation by agarose gel electrophoresis. Conclusions/Significance The data presented in the current study suggest that MDL28170 induces apoptotic marker expression in promastigotes of L. amazonensis. Altogether, the results described in the present work not only provide a rationale for further exploration of the mechanism of action of calpain inhibitors against trypanosomatids, but may also widen the investigation of the

  14. Evaluation of Macroalgae Sulfated Polysaccharides on the Leishmania (L.) amazonensis Promastigote

    PubMed Central

    Pires, Camila Lehnhardt; Rodrigues, Selma Dzimidas; Bristot, Daniel; Gaeta, Henrique Hessel; de Oliveira Toyama, Daniela; Farias, Wladimir Ronald Lobo; Toyama, Marcos Hikari

    2013-01-01

    The sulfated polysaccharides from Solieria filiformis (Sf), Botryocladia occidentalis (Bo), Caulerpa racemosa (Cr) and Gracilaria caudata (Gc) were extracted and extensively purified. These compounds were then subjected to in vitro assays to evaluate the inhibition of these polysaccharides on the growth of Leishmania (L.) amazonensis promastigotes. Under the same assay conditions, only three of the four sulfated polysaccharides were active against L. amazonensis, and the polysaccharide purified from Cr was the most potent (EC50 value: 34.5 μg/mL). The polysaccharides derived from Bo and Sf demonstrated moderate anti-leishmanial activity (EC50 values of 63.7 μg/mL and 137.4 μg/mL). In addition, we also performed in vitro cytotoxic assays toward peritoneal macrophages and J774 macrophages. For the in vitro cytotoxicity assay employing J774 cells, all of the sulfated polysaccharides decreased cell survival, with CC50 values of 27.3 μg/mL, 49.3 μg/mL, 73.2 μg/mL, and 99.8 μg/mL for Bo, Cr, Gc, and Sf, respectively. However, none of the sulfated polysaccharides reduced the cell growth rate of the peritoneal macrophages. These results suggest that macroalgae contain compounds with various chemical properties that can control specific pathogens. According to our results, the assayed sulfated polysaccharides were able to modulate the growth rate and cell survival of Leishmania (L.) amazonensis promastigotes in in vitro assays, and these effects involved the interaction of the sulfated polysaccharides on the cell membrane of the parasites. PMID:23519148

  15. Evaluation of macroalgae sulfated polysaccharides on the Leishmania (L.) amazonensis promastigote.

    PubMed

    Lehnhardt Pires, Camila; Rodrigues, Selma Dzimidas; Bristot, Daniel; Gaeta, Henrique Hessel; de Oliveira Toyama, Daniela; Lobo Farias, Wladimir Ronald; Toyama, Marcos Hikari

    2013-03-20

    The sulfated polysaccharides from Solieria filiformis (Sf), Botryocladia occidentalis (Bo), Caulerpa racemosa (Cr) and Gracilaria caudata (Gc) were extracted and extensively purified. These compounds were then subjected to in vitro assays to evaluate the inhibition of these polysaccharides on the growth of Leishmania (L.) amazonensis promastigotes. Under the same assay conditions, only three of the four sulfated polysaccharides were active against L. amazonensis, and the polysaccharide purified from Cr was the most potent (EC50 value: 34.5 μg/mL). The polysaccharides derived from Bo and Sf demonstrated moderate anti-leishmanial activity (EC50 values of 63.7 μg/mL and 137.4 μg/mL). In addition, we also performed in vitro cytotoxic assays toward peritoneal macrophages and J774 macrophages. For the in vitro cytotoxicity assay employing J774 cells, all of the sulfated polysaccharides decreased cell survival, with CC50 values of 27.3 μg/mL, 49.3 μg/mL, 73.2 μg/mL, and 99.8 μg/mL for Bo, Cr, Gc, and Sf, respectively. However, none of the sulfated polysaccharides reduced the cell growth rate of the peritoneal macrophages. These results suggest that macroalgae contain compounds with various chemical properties that can control specific pathogens. According to our results, the assayed sulfated polysaccharides were able to modulate the growth rate and cell survival of Leishmania (L.) amazonensis promastigotes in in vitro assays, and these effects involved the interaction of the sulfated polysaccharides on the cell membrane of the parasites.

  16. The calpain inhibitor MDL28170 induces the expression of apoptotic markers in Leishmania amazonensis promastigotes.

    PubMed

    Marinho, Fernanda A; Gonçalves, Keyla C S; Oliveira, Simone S C; Gonçalves, Diego S; Matteoli, Filipe P; Seabra, Sergio H; Oliveira, Ana Carolina S; Bellio, Maria; Oliveira, Selma S; Souto-Padrón, Thaïs; d'Avila-Levy, Claudia M; Santos, André L S; Branquinha, Marta H

    2014-01-01

    Human cutaneous leishmaniasis is caused by distinct species, including Leishmania amazonensis. Treatment of cutaneous leishmaniasis is far from satisfactory due to increases in drug resistance and relapses, and toxicity of compounds to the host. As a consequence for this situation, the development of new leishmanicidal drugs and the search of new targets in the parasite biology are important goals. In this study, we investigated the mechanism of death pathway induced by the calpain inhibitor MDL28170 on Leishmania amazonensis promastigote forms. The combined use of different techniques was applied to contemplate this goal. MDL28170 treatment with IC50 (15 µM) and two times the IC50 doses induced loss of parasite viability, as verified by resazurin assay, as well as depolarization of the mitochondrial membrane, which was quantified by JC-1 staining. Scanning and transmission electron microscopic images revealed drastic alterations on the parasite morphology, some of them resembling apoptotic-like death, including cell shrinking, surface membrane blebs and altered chromatin condensation pattern. The lipid rearrangement of the plasma membrane was detected by Annexin-V labeling. The inhibitor also induced a significant increase in the proportion of cells in the sub-G0/G1 phase, as quantified by propidium iodide staining, as well as genomic DNA fragmentation, detected by TUNEL assay. In cells treated with MDL28170 at two times the IC50 dose, it was also possible to observe an oligonucleossomal DNA fragmentation by agarose gel electrophoresis. The data presented in the current study suggest that MDL28170 induces apoptotic marker expression in promastigotes of L. amazonensis. Altogether, the results described in the present work not only provide a rationale for further exploration of the mechanism of action of calpain inhibitors against trypanosomatids, but may also widen the investigation of the potential clinical utility of calpain inhibitors in the chemotherapy of

  17. Leishmanicidal evaluation of extracts from native plants of the Yucatan peninsula.

    PubMed

    Peraza-Sánchez, S R; Cen-Pacheco, F; Noh-Chimal, A; May-Pat, F; Simá-Polanco, P; Dumonteil, E; García-Miss, M R; Mut-Martín, M

    2007-06-01

    Methanol extracts were prepared from different parts of 18 plants collected in the Yucatan peninsula and evaluated in an in vitro bioassay for leishmanicidal activity against Leishmania mexicana promastigotes. The ten most potent plant extracts (IC(50)<50 microg/ml) were Aphelandra scabra leaves, Byrsonima bucidaefolia bark, Byrsonima crassifolia bark, Clusia flava leaves, Cupania dentata bark, Diphysa carthagenensis leaves, Dorstenia contrajerva whole plant, Milleria quinqueflora roots, Tridax procumbens whole plant, and Vitex gaumeri bark.

  18. Ultrastructural Changes and Death of Leishmania infantum Promastigotes Induced by Morinda citrifolia Linn. Fruit (Noni) Juice Treatment.

    PubMed

    Almeida-Souza, Fernando; Taniwaki, Noemi Nosomi; Amaral, Ana Cláudia Fernandes; de Souza, Celeste da Silva Freitas; Calabrese, Kátia da Silva; Abreu-Silva, Ana Lúcia

    2016-01-01

    The search for new treatments against leishmaniasis has increased due to high frequency of drug resistance registered in endemics areas, side effects, and complications caused by coinfection with HIV. Morinda citrifolia Linn., commonly known as Noni, has a rich chemical composition and various therapeutic effects have been described in the literature. Studies have shown the leishmanicidal activity of M. citrifolia; however, its action on the parasite has not yet been elucidated. In this work, we analyzed leishmanicidal activity and ultrastructural changes in Leishmania infantum promastigotes caused by M. citrifolia fruit juice treatment. M. citrifolia fruit extract showed a yield of 6.31% and high performance liquid chromatography identified phenolic and aromatic compounds as the major constituents. IC50 values were 260.5 µg/mL for promastigotes and 201.3 µg/mL for intracellular amastigotes of L. infantum treated with M. citrifolia. Cytotoxicity assay with J774.G8 macrophages showed that M. citrifolia fruit juice was not toxic up to 2 mg/mL. Transmission electron microscopy showed cytoplasmic vacuolization, lipid inclusion, increased exocytosis activity, and autophagosome-like vesicles in L. infantum promastigotes treated with M. citrifolia fruit juice. M. citrifolia fruit juice was active against L. infantum in the in vitro model used here causing ultrastructural changes and has a future potential for treatment against leishmaniasis.

  19. In vitro selection of miltefosine resistance in promastigotes of Leishmania donovani from Nepal: genomic and metabolomic characterization.

    PubMed

    Shaw, C D; Lonchamp, J; Downing, T; Imamura, H; Freeman, T M; Cotton, J A; Sanders, M; Blackburn, G; Dujardin, J C; Rijal, S; Khanal, B; Illingworth, C J R; Coombs, G H; Carter, K C

    2016-03-01

    In this study, we followed the genomic, lipidomic and metabolomic changes associated with the selection of miltefosine (MIL) resistance in two clinically derived Leishmania donovani strains with different inherent resistance to antimonial drugs (antimony sensitive strain Sb-S; and antimony resistant Sb-R). MIL-R was easily induced in both strains using the promastigote-stage, but a significant increase in MIL-R in the intracellular amastigote compared to the corresponding wild-type did not occur until promastigotes had adapted to 12.2 μM MIL. A variety of common and strain-specific genetic changes were discovered in MIL-adapted parasites, including deletions at the LdMT transporter gene, single-base mutations and changes in somy. The most obvious lipid changes in MIL-R promastigotes occurred to phosphatidylcholines and lysophosphatidylcholines and results indicate that the Kennedy pathway is involved in MIL resistance. The inherent Sb resistance of the parasite had an impact on the changes that occurred in MIL-R parasites, with more genetic changes occurring in Sb-R compared with Sb-S parasites. Initial interpretation of the changes identified in this study does not support synergies with Sb-R in the mechanisms of MIL resistance, though this requires an enhanced understanding of the parasite's biochemical pathways and how they are genetically regulated to be verified fully.

  20. Ultrastructural Changes and Death of Leishmania infantum Promastigotes Induced by Morinda citrifolia Linn. Fruit (Noni) Juice Treatment

    PubMed Central

    Almeida-Souza, Fernando; Taniwaki, Noemi Nosomi; Amaral, Ana Cláudia Fernandes; de Souza, Celeste da Silva Freitas; Calabrese, Kátia da Silva; Abreu-Silva, Ana Lúcia

    2016-01-01

    The search for new treatments against leishmaniasis has increased due to high frequency of drug resistance registered in endemics areas, side effects, and complications caused by coinfection with HIV. Morinda citrifolia Linn., commonly known as Noni, has a rich chemical composition and various therapeutic effects have been described in the literature. Studies have shown the leishmanicidal activity of M. citrifolia; however, its action on the parasite has not yet been elucidated. In this work, we analyzed leishmanicidal activity and ultrastructural changes in Leishmania infantum promastigotes caused by M. citrifolia fruit juice treatment. M. citrifolia fruit extract showed a yield of 6.31% and high performance liquid chromatography identified phenolic and aromatic compounds as the major constituents. IC50 values were 260.5 µg/mL for promastigotes and 201.3 µg/mL for intracellular amastigotes of L. infantum treated with M. citrifolia. Cytotoxicity assay with J774.G8 macrophages showed that M. citrifolia fruit juice was not toxic up to 2 mg/mL. Transmission electron microscopy showed cytoplasmic vacuolization, lipid inclusion, increased exocytosis activity, and autophagosome-like vesicles in L. infantum promastigotes treated with M. citrifolia fruit juice. M. citrifolia fruit juice was active against L. infantum in the in vitro model used here causing ultrastructural changes and has a future potential for treatment against leishmaniasis. PMID:27313649

  1. Reduced hamster usage and stress in propagating Leishmania chagasi promastigotes using cryopreservation and saphenous vein inoculation.

    PubMed

    Lei, Soi Meng; Ramer-Tait, Amanda E; Dahlin-Laborde, Rebecca R; Mullin, Kathleen; Beetham, Jeffrey K

    2010-02-01

    Leishmania chagasi, a causal agent of visceral leishmaniasis, requires passage through lab animals such as hamsters to maintain its virulence. Hamster infection is typically accomplished via cardiac puncture or intraperitoneal injection, procedures accompanied by risks of increased animal stress and death. The use of the hamster model also necessitates a regular supply of infected animals, because L. chagasi parasites newly isolated from an infected hamster can be grown in culture for only several weeks before loss of function/phenotype occurs. In an effort to decrease animal usage and animal stress, experiments were performed to assess a more gentle inoculation procedure (saphenous vein inoculation) and the use of cryopreserved parasite cells for research experiments. Of 81 hamsters inoculated by the saphenous vein, 80 became infected as determined ante mortem, by display of clinical symptoms of leishmaniasis (onset of symptoms at 105 +/- 22 days post-inoculation), and postmortem by the presence of parasites within the spleen. Splenic parasite load calculated for a subset (n = 34) of infected hamsters was 124 to 26,177 Leishmania donovani infection units. Cryopreserved, and never-stored, cells were equivalent in all properties evaluated, including developmental changes in morphology during culture, culture growth rates, parasite resistance to serum-mediated lysis, and expression of developmentally regulated surface proteins major surface protease and promastigote surface antigen.

  2. A high affinity Ca2(+)-ATPase on the surface membrane of Leishmania donovani promastigote

    SciTech Connect

    Ghosh, J.; Ray, M.; Sarkar, S.; Bhaduri, A. )

    1990-07-05

    A Ca2(+)-dependent ATP-hydrolytic activity was detected in the crude membrane ghost of the promastigote or vector form of the protozoal parasite Leishmania donovani, the pathogen responsible for kala azar. The Ca2(+)-ATPase was purified to apparent homogeneity after solubilization with deoxycholate. The enzyme consists of two subunits of Mr = 51,000 and 57,000 and has an apparent molecular weight of 215,000 +/- 12,000. The enzyme activity is exclusively dependent on Ca2+, and the pure enzyme can hydrolyze 1.6 mumol of ATP/min/mg of protein. The apparent Km for Ca2+ is 35 nM, which is further reduced to 12 nM in the presence of heterologous calmodulin. The enzyme is sensitive to vanadate, but is insensitive to oligomycin and ouabain. The enzyme is strongly associated with the plasma membrane and has its catalytic site oriented toward the cytoplasmic face. The enzyme spans across the plasma membrane as surface labeling with radioiodine shows considerable radioactivity in the completely purified enzyme. The localization and orientation of this high affinity, calmodulin-sensitive Ca2(+)-ATPase suggest some role of this enzyme in Ca2+ movement in the life cycle of this protozoal parasite.

  3. Cloning expression and characterization of methionine adenosyltransferase in Leishmania infantum promastigotes.

    PubMed

    Reguera, Rosa M; Balaña-Fouce, Rafael; Pérez-Pertejo, Yolanda; Fernández, Francisco J; García-Estrada, Carlos; Cubría, Juan C; Ordóñez, César; Ordóñez, David

    2002-02-01

    Methionine adenosyltransferase (MAT) catalyzes the synthesis of s-adenosylmethionine (AdoMet), a metabolite that plays an important role in a variety of cellular functions, such as methylation, sulfuration, and polyamine synthesis. In this study, genomic DNA from the protozoan parasite Leishmania infantum was cloned and characterized. L. infantum MAT, unlike mammalian MAT, is codified by two identical genes in a tandem arrangement and is only weakly regulated by AdoMet. L. infantum MAT mRNA is expressed as a single transcript, with the enzyme forming a homodimer with tripolyphosphatase in addition to MAT activity. Expression of L. infantum MAT in Escherichia coli proves that the MAT and tripolyphosphatase activities are functional in vivo. MAT shows sigmoidal behavior and is weakly inhibited by AdoMet, whereas tripolyphosphatase activity has sigmoidal behavior and is strongly activated by AdoMet. Plasmids containing the regions flanking MAT2 were fused immediately upstream and downstream of the luciferase-coding region and transfected into L. infantum. Subsequent examination of luciferase activity showed that homologous expression in L. infantum promastigotes was dramatically dependent on the presence of polypyrimidine tracts and a spliced leader junction site upstream of the luciferase gene, whereas downstream sequences appeared to have no bearing on expression.

  4. Leishmania (Leishmania) amazonensis: purification and enzymatic characterization of a soluble serine oligopeptidase from promastigotes.

    PubMed

    de Andrade, A S; Santoro, M M; de Melo, M N; Mares-Guia, M

    1998-06-01

    A soluble proteinase was purified 90-fold from extracts of promastigotes of Leishmania (Leishmania) amazonensis using a combination of ion-exchange chromatography in Q-Sepharose Fast Flow, gel filtration chromatography in Sephacryl HR S-200, and chromatofocusing. The enzyme appeared as a single band with an apparent molecular weight of 101 kDa by silver staining following SDS-PAGE, under both reducing and nonreducing conditions. The proteinase has a pH optimum between 8.0 and 8.5 and an isoelectric point between 5.12 and 5.23, belongs to the serine proteinase class, and is inhibited by Mg2+, Ca2+, and K+. The primary specificity determined using synthetic substrates is for basic amino acids. The kinetic parameters for the Bz-L-Arg-Nam substrate are Km = 26 microM, kcat = 32 min(-1), and Ksi = 1270 microM (the proteinase showed inhibition by excess substrate). The enzyme does not hydrolyze casein, albumin, and gelatin or large peptides like the oxidized insulin B chain, but hydrolyzes small peptides like bradykinin and fragment 4-10 of the adrenocorticotropic hormone, at the carboxyl side of basic residues and aromatic residues preceding basic residues. The enzyme appears, thus, to be restricted in its action, cleaving only small peptide substrates, which characterizes the proteinase as an oligopeptidase. This is the first report of purification of a serine peptidase from Leishmania species and it increases the short list of known oligopeptidases.

  5. Artemisinin triggers induction of cell-cycle arrest and apoptosis in Leishmania donovani promastigotes.

    PubMed

    Sen, Rupashree; Bandyopadhyay, Samiran; Dutta, Avijit; Mandal, Goutam; Ganguly, Sudipto; Saha, Piu; Chatterjee, Mitali

    2007-09-01

    A major impediment to effective anti-leishmanial chemotherapy is the emergence of drug resistance, especially to sodium antimony gluconate, the first-line treatment for leishmaniasis. Artemisinin, a sesquiterpene lactone isolated from Artemisia annua, is an established anti-malarial compound that showed anti-leishmanial activity in both promastigotes and amastigotes, with IC(50) values of 160 and 22 microM, respectively, and, importantly, was accompanied by a high safety index (>22-fold). The leishmanicidal activity of artemisinin was mediated via apoptosis as evidenced by externalization of phosphatidylserine, loss of mitochondrial membrane potential, in situ labelling of DNA fragments by terminal deoxyribonucleotidyltransferase-mediated dUTP nick end labelling (TUNEL) and cell-cycle arrest at the sub-G(0)/G(1) phase. Taken together, these data indicate that artemisinin has promising anti-leishmanial activity that is mediated by programmed cell death and, accordingly, merits consideration and further investigation as a therapeutic option for the treatment of leishmaniasis.

  6. Tomatidine promotes the inhibition of 24-alkylated sterol biosynthesis and mitochondrial dysfunction in Leishmania amazonensis promastigotes.

    PubMed

    Medina, J M; Rodrigues, J C F; De Souza, W; Atella, G C; Barrabin, H

    2012-09-01

    Leishmaniasis is a set of clinically distinct infectious diseases caused by Leishmania, a genus of flagellated protozoan parasites, that affects ~12 million people worldwide, with ~2 million new infections annually. Plants are known to produce substances to defend themselves against pathogens and predators. In the genus Lycopersicon, which includes the tomato, L. esculentum, the main antimicrobial compound is the steroidal glycoalkaloid α-tomatine. The loss of the saccharide side-chain of tomatine yields the aglycone tomatidine. In the present study, we investigated the effects of tomatidine on the growth, mitochondrial membrane potential, sterol metabolism, and ultrastructure of Leishmania amazonensis promastigotes. Tomatidine (0·1 to 5 μM) inhibited parasite growth in a dose-dependent manner (IC(50)=124±59 nM). Transmission electron microscopy revealed lesions in the mitochondrial ultrastructure and the presence of large vacuoles and lipid storage bodies in the cytoplasm. These structural changes in the mitochondria were accompanied by an effective loss of mitochondrial membrane potential and a decrease in ATP levels. An analysis of the neutral lipid content revealed a large depletion of endogenous 24-alkylated sterols such as 24-methylene-cholesta-5, 7-dien-3β-ol (5-dehydroepisterol), with a concomitant accumulation of cholesta-8, 24-dien-3β-ol (zymosterol), which implied a perturbation in the cellular lipid content. These results are consistent with an inhibition of 24-sterol methyltransferase, an important enzyme responsible for the methylation of sterols at the 24 position, which is an essential step in the production of ergosterol and other 24-methyl sterols.

  7. Leishmania (Leishmania) amazonensis: purification and characterization of a promastigote serine protease.

    PubMed

    da Silva-Lopez, Raquel Elisa; Giovanni-De-Simone, Salvatore

    2004-01-01

    Pathogenic protozoan proteases play crucial roles in the host-parasite interaction, and its characterization contributes to the understanding of protozoan disease mechanisms. A Leishmania amazonensis promastigote protease was purified 36-fold, using aprotinin-agarose affinity chromatography and gel filtration high performance liquid chromatography, yielding a total recovery of 49%. The molecular mass of active enzyme obtained from native gel filtration HPLC and SDS-PAGE under conditions of reduction and non-reduction was 68 kDa, suggesting that the enzyme may exist as a monomer. The protease isoelectric point (pI) was around 4.45 and, as demonstrated by deglycosylation assay, it did not have any carbohydrate content. The optimal pH and temperature of the enzyme were 8.0 and 28 degrees C, respectively, determined using alpha-N-rho-tosyl-L-arginyl-methyl ester (L-TAME) as substrate. Assays of thermal stability indicated that 50% of the enzymatic activity was preserved after 4 min of pre-treatment at 42 degrees C and after 24 h of pre-treatment at 37 degrees C, both in the absence of substrate. Hemoglobin, bovine serum albumin (BSA), ovalbumin, and both gelatin and peptide substrates containing arginine in ester bound were hydrolyzed by 68 kDa protease. The insulin beta-chain was also hydrolyzed by the protease, and four peptidic bonds (L11-V12, E13-A14, L15-Y16, and Y16-L17) were susceptible to the 68-kDa protease action. Inhibition studies suggested that the enzyme belonged to a serine protease class inhibited by calcium ions and activated by manganese ions. These findings demonstrate that the L. amazonensis 68-kDa serine protease differs from those of other protozoan parasites.

  8. Ca2+ transport in isolated mitochondrial vesicles from Leishmania braziliensis promastigotes.

    PubMed

    Benaim, G; Bermudez, R; Urbina, J A

    1990-02-01

    Leishmania braziliensis maintained very low (50 +/- 20 nM) intracellular concentrations of calcium ions under normal conditions, as shown by the fluorimetric indicator QUIN2. Digitonin-permeabilized cells liberated large amounts of calcium ions in the presence of the ionophore A23187, indicating the presence of a large intracellular reservoir for this ion. Given the extraordinary extension of the single giant mitochondrion of Kinetoplastida and the known capacity of mitochondria from other sources to accumulate calcium, we tested the capacity of this organelle to accumulate calcium ions in Leishmania. Coupled mitochondrial vesicles, five-fold enriched in succinate-cytochrome c oxidoreductase, were obtained from promastigotes by gentle grinding (45 s) with glass beads in hypertonic buffer solution, followed by differential centrifugation. These vesicles had a respiratory control ratio of 1.82 +/- 0.15, and two phosphorylation sites (sites II and III) using succinate as electron donor, and were capable of calcium uptake in the presence of several respiratory substrates; this uptake was enhanced in the presence of ADP and Pi and was blocked by classical electron transport inhibitors. Uncouplers such as carbonyl cyanide p-trifluoromethoxy-phenylhydrazone (FCCP) and the calcium ionophore A23187 released previously accumulated calcium ions, suggesting that the driving force for the calcium uptake by the vesicles is the respiratory generated electrochemical potential gradient of protons. A study of the affinity of this system for calcium showed that even at 90 microM free calcium, succinate-induced calcium uptake is not saturated while approaching a level of 200 nmol min-1 (mg protein)-1, indicating a low-affinity, large-capacity system.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. The effect of verapamil on in vitro susceptibility of promastigote and amastigote stages of Leishmania tropica to meglumine antimoniate.

    PubMed

    Shokri, Azar; Sharifi, Iraj; Khamesipour, Ali; Nakhaee, Nozar; Fasihi Harandi, Majid; Nosratabadi, Jafar; Hakimi Parizi, Maryam; Barati, Mohammad

    2012-03-01

    Pentavalent antimonials are the standard treatment for cutaneous leishmaniasis (CL) with low efficacy and resistance is emerging. CL is increased significantly in respect to incidence rate and expanding to new foci. In the present study, the effect of verapamil on in vitro susceptibility of promastigote and amastigote stages of Leishmania tropica to meglumine antimoniate (MA, Glucantime) was evaluated using colorimetric assay (MTT) and in a macrophage model, respectively. Verapamil, as a calcium channel blocker, affects drug uptake by preventing of drug efflux from the cells. In promastigote form, several concentrations of MA with or without verapamil showed significant decrease (P < 0.05) in optical density. The overall mean IC₅₀ value with combination of MA plus verapamil (IC50 = 116.03 μg/ml) was significantly less than MA (IC50 = 225.14 μg/ml) alone (P < 0.05) for promastigote stage. Similarly, the amastigote stage was more susceptible to treatment with MA plus verapamil to that of MA alone (P < 0.05). Analysis of overall effect of different concentrations of MA alone, compared with combination of MA plus verapamil by mean infection rate of amastigotes in each macrophage showed a significant difference (P < 0.05).These findings indicated some degree of synergistic effects between MA and verapamil on in vitro susceptibility of L. tropica to MA. Further works are required to evaluate this synergistic effect on animal model or volunteer human subjects.

  10. Recombinant Forms of Leishmania amazonensis Excreted/Secreted Promastigote Surface Antigen (PSA) Induce Protective Immune Responses in Dogs

    PubMed Central

    Petitdidier, Elodie; Pagniez, Julie; Papierok, Gérard; Vincendeau, Philippe; Lemesre, Jean-Loup; Bras-Gonçalves, Rachel

    2016-01-01

    Preventive vaccination is a highly promising strategy for interrupting leishmaniasis transmission that can, additionally, contribute to elimination. A vaccine formulation based on naturally excreted secreted (ES) antigens was prepared from L. infantum promastigote culture supernatant. This vaccine achieved successful results in Phase III trials and was licensed and marketed as CaniLeish. We recently showed that newly identified ES promastigote surface antigen (PSA), from both viable promastigotes and axenically-grown amastigotes, represented the major constituent and the highly immunogenic antigen of L. infantum and L. amazonensis ES products. We report here that three immunizations with either the recombinant ES LaPSA-38S (rPSA) or its carboxy terminal part LaPSA-12S (Cter-rPSA), combined with QA-21 as adjuvant, confer high levels of protection in naive L. infantum-infected Beagle dogs, as checked by bone marrow parasite absence in respectively 78.8% and 80% of vaccinated dogs at 6 months post-challenge. The parasite burden in infected vaccinated dogs was significantly reduced compared to placebo group, as measured by q-PCR. Moreover, our results reveal humoral and cellular immune response clear-cut differences between vaccinated and control dogs. An early increase in specific IgG2 antibodies was observed in rPSA/QA-21- and Cter-rPSA/QA-21-immunized dogs only. They were found functionally active in vitro and were highly correlated with vaccine protection. In vaccinated protected dogs, IFN-γ and NO productions, as well as anti-leishmanial macrophage activity, were increased. These data strongly suggest that ES PSA or its carboxy-terminal part, in recombinant forms, induce protection in a canine model of zoonotic visceral leishmaniasis by inducing a Th1-dominant immune response and an appropriate specific antibody response. These data suggest that they could be considered as important active components in vaccine candidates. PMID:27223609

  11. Antileishmanial activity of cryptolepine analogues and apoptotic effects of 2,7-dibromocryptolepine against Leishmania donovani promastigotes.

    PubMed

    Hazra, Sudipta; Ghosh, Subhalakshmi; Debnath, Sukalyani; Seville, Scott; Prajapati, Vijay Kumar; Wright, Colin W; Sundar, Shyam; Hazra, Banasri

    2012-07-01

    Cryptolepine (5-methyl-10H-indolo [3, 2-b] quinoline), an indoloquinoline alkaloid (1) isolated from a medicinal plant traditionally used in Western Africa for treatment of malaria, has been shown to possess broad spectrum biological activity in addition to its antiplasmodial effect. Here, the antileishmanial properties of 11 synthetic derivatives of cryptolepine against Leishmania donovani parasites have been evaluated for the first time. 2,7-Dibromocryptolepine (8; IC50 0.5 ± 0.1 μM) was found to be the most active analogue against the promastigote form of a classical L. donovani strain (AG83) in comparison to the natural alkaloid, cryptolepine (1; IC50 1.6 ± 0.1 μM). Further, 8 was found to substantially inhibit the intracellular amastigote forms of two clinical isolates, one of them being an SbV-resistant strain of L. donovani. Moreover, the toxicity of 8 against normal mouse peritoneal macrophage cells was markedly lower than that of 1 (IC50 values: 9.0 ± 1.2 and 1.1 ± 0.3 μM, respectively), indicating 8 to be a prospective “lead” towards novel antileishmanial therapy. This was supported by studies on the mechanism of cytotoxicity induced by 8 in L. donovani promastigotes (AG83), which revealed the cytoplasmic and nuclear features of metazoan apoptosis. Light microscopic observation demonstrated a gradual decline in the motility, cell volume, and survival of the treated parasites with increasing incubation time. Flow cytometric analysis of phosphatidylserine externalization and distribution of cells in different phases of cell cycle confirmed the presence of a substantial percentage of cells in early apoptotic stage. Disruption of mitochondrial membrane integrity in terms of depolarization of membrane potential, and finally degradation of chromosomal DNA into oligonucleosomal fragments - the hallmark event of apoptosis - characterized the mode of cell death in L. donovani promastigotes.

  12. Combined effect of the essential oil from Chenopodium ambrosioides and antileishmanial drugs on promastigotes of Leishmania amazonensis.

    PubMed

    Monzote, Lianet; Montalvo, Ana Margarita; Scull, Ramón; Miranda, Migdalia; Abreu, Juan

    2007-01-01

    To date, there are no vaccines against Leishmania, and chemotherapy remains the mainstay for the control of leishmaniasis. The drugs of choice used for leishmaniasis therapy are significantly toxic, expensive and with a growing frequency of refractory infections. Because of these limitations, a combination therapy is the better hope. This work demonstrates that the essential oil from Chenopodium ambrosioides shows a synergic activity after incubation in conjunction with pentamidine against promastigotes of Leishmania amazonensis. However, an indifferent effect has been found for combinations of meglumine antimoniate or amphotericin B and the essential oil.

  13. Citric-acid cycle key enzyme activities during in vitro growth and metacyclogenesis of Leishmania infantum promastigotes.

    PubMed

    Louassini, M; Foulquié, M; Benítez, R; Adroher, J

    1999-08-01

    The activities of 5 key regulatory enzymes in most energetic systems, namely citrate synthase (EC 4.1.3.7, CS), NADP-specific isocitrate dehydrogenase (EC 1.1.1.42, ICDH), succinate dehydrogenase (EC 1.3.99.1, SDH), L-malate dehydrogenase (EC 1.1.1.37, MDH), and decarboxylating malic enzyme (EC 1.1.1.40, ME), were measured during the growth and metacyclogenesis of a cutaneous (CL) and a visceral (VL) strain of Leishmania infantum. As occurs with other Leishmania species, infective promastigotes were present along all phases of growth, but their percentages were higher at the early stationary phase for VL and the end of the same phase for CL. High CS and SDH activities were detected in both strains, as compared with other trypanosomatids, bringing more evidence for an actively functional citric-acid cycle in L. infantum. Both strains showed higher levels of CS, ICDH, and MDH and lower SDH and ME activities when more metacyclic promastigotes were present, but in VL these changes paralleled an increase in glucose consumption, whereas in CL these changes coincided with an NH3 hyperproduction. This suggests that the energy metabolism during L. infantum growth and metacyclogenesis is affected by regulated enzymes that probably respond to changes in the culture medium in the levels of glucose and amino acids.

  14. Identification of Leishmania spp. promastigotes in the intestines, ovaries, and salivary glands of Rhipicephalus sanguineus actively infesting dogs.

    PubMed

    Viol, Milena Araúz; Guerrero, Felix D; de Oliveira, Bruno César Miranda; de Aquino, Monally Conceição Costa; Loiola, Saulo Hudson; de Melo, Guilherme Dias; de Souza Gomes, Aparecida Helena; Kanamura, Cristina Takami; Garcia, Marcos Valério; Andreotti, Renato; de Lima, Valéria Marçal Félix; Bresciani, Katia Denise Saraiva

    2016-09-01

    Sand flies are recognized as the major vector of canine visceral leishmaniasis. However, in some areas of Brazil where sand flies do not occur, this disease is found in humans and dogs. There has been speculation that ticks might play a role in transmission of canine visceral leishmaniasis and the DNA of Leishmania spp. has been reported in whole ticks. We investigated the presence of Leishmania spp. promastigotes in the intestines, ovaries, and salivary glands of Rhipicephalus sanguineus ticks collected from tick-infested dogs in two cities of Brazil. We used 66 dogs that tested positive and 33 that tested negative for Leishmania spp. according to direct cytological examination assays. Ten ticks were collected from each dog and dissected to collect the intestines, ovaries, and salivary glands for immunohistochemistry (IHC) and diagnostic real-time polymerase chain reaction (RT-PCR). IHC results showed Leishmania spp. in 98, 14, and 8 % of the intestines, ovaries, and salivary glands, respectively. Real-time PCR showed that 89, 41, and 33 % of the tick intestine, ovary, and salivary glands, respectively, were positive for Leishmania spp. The verification of promastigotes of Leishmania spp. by two independent techniques in ticks collected from these urban region dogs showed that there is need for clarification of the role of ticks in the transmission of canine visceral leishmaniasis in Brazil.

  15. In vitro selection of miltefosine resistance in promastigotes of Leishmania donovani from Nepal: genomic and metabolomic characterization

    PubMed Central

    Shaw, C. D.; Lonchamp, J.; Downing, T.; Imamura, H.; Freeman, T. M.; Cotton, J. A.; Sanders, M.; Blackburn, G.; Dujardin, J. C.; Rijal, S.; Khanal, B.; Illingworth, C. J. R.; Coombs, G. H.

    2016-01-01

    Summary In this study, we followed the genomic, lipidomic and metabolomic changes associated with the selection of miltefosine (MIL) resistance in two clinically derived Leishmania donovani strains with different inherent resistance to antimonial drugs (antimony sensitive strain Sb‐S; and antimony resistant Sb‐R). MIL‐R was easily induced in both strains using the promastigote‐stage, but a significant increase in MIL‐R in the intracellular amastigote compared to the corresponding wild‐type did not occur until promastigotes had adapted to 12.2 μM MIL. A variety of common and strain‐specific genetic changes were discovered in MIL‐adapted parasites, including deletions at the LdMT transporter gene, single‐base mutations and changes in somy. The most obvious lipid changes in MIL‐R promastigotes occurred to phosphatidylcholines and lysophosphatidylcholines and results indicate that the Kennedy pathway is involved in MIL resistance. The inherent Sb resistance of the parasite had an impact on the changes that occurred in MIL‐R parasites, with more genetic changes occurring in Sb‐R compared with Sb‐S parasites. Initial interpretation of the changes identified in this study does not support synergies with Sb‐R in the mechanisms of MIL resistance, though this requires an enhanced understanding of the parasite's biochemical pathways and how they are genetically regulated to be verified fully. PMID:26713880

  16. Leishmania amazonensis: chemotaxic and osmotaxic responses in promastigotes and their probable role in development in the phlebotomine gut.

    PubMed

    Barros, V C; Oliveira, J S; Melo, M N; Gontijo, N F

    2006-03-01

    Taxic responses may play a role in development of Leishmania in their phlebotomine sand fly vectors. They are possibly responsible for movement of the parasites towards the anterior regions of the gut, from where they would be transmitted to the vertebrate host. A methodology capable to distinguish chemotaxic from osmotaxic responses was described and used to characterise taxic responses in Leishmania promastigotes. These were able to respond to chemotaxic as well as to osmotaxic stimuli. Like bacteria, promastigotes were capable to undergo "adaptation," a phenomenon by which they stop responding to a continuos stimulus. A model capable to explain how a relatively small number of different receptors works to perceive gradients in chemotaxic responses was proposed. According to this model, these receptors possess low specificity and a wide range of affinities varying from high to low. A low specificity makes the same receptor able to bind to a large number of different but structurally related molecules and; a wide range of affinities (considering a population of receptors), implies that the number of receptors "occupied" by attractant molecules along a gradient would go growing step by step.

  17. Deprivation of L-Arginine Induces Oxidative Stress Mediated Apoptosis in Leishmania donovani Promastigotes: Contribution of the Polyamine Pathway

    PubMed Central

    Mandal, Abhishek; Das, Sushmita; Roy, Saptarshi; Ghosh, Ayan Kumar; Sardar, Abul Hasan; Verma, Sudha; Saini, Savita; Singh, Ruby; Abhishek, Kumar; Kumar, Ajay; Mandal, Chitra; Das, Pradeep

    2016-01-01

    The growth and survival of intracellular parasites depends on the availability of extracellular nutrients. Deprivation of nutrients viz glucose or amino acid alters redox balance in mammalian cells as well as some lower organisms. To further understand the relationship, the mechanistic role of L-arginine in regulation of redox mediated survival of Leishmania donovani promastigotes was investigated. L-arginine deprivation from the culture medium was found to inhibit cell growth, reduce proliferation and increase L-arginine uptake. Relative expression of enzymes, involved in L-arginine metabolism, which leads to polyamine and trypanothione biosynthesis, were downregulated causing decreased production of polyamines in L-arginine deprived parasites and cell death. The resultant increase in reactive oxygen species (ROS), due to L-arginine deprivation, correlated with increased NADP+/NADPH ratio, decreased superoxide dismutase (SOD) level, increased lipid peroxidation and reduced thiol content. A deficiency of L-arginine triggered phosphatidyl serine externalization, a change in mitochondrial membrane potential, release of intracellular calcium and cytochrome-c. This finally led to DNA damage in Leishmania promastigotes. In summary, the growth and survival of Leishmania depends on the availability of extracellular L-arginine. In its absence the parasite undergoes ROS mediated, caspase-independent apoptosis-like cell death. Therefore, L-arginine metabolism pathway could be a probable target for controlling the growth of Leishmania parasites and disease pathogenesis. PMID:26808657

  18. The proliferation potential of promastigotes of the main Leishmania species of the old world in NNN culture medium prepared using blood of four different mammals.

    PubMed

    Ladopoulos, Theodoros; Ntais, Pantelis; Tsirigotakis, Nikolaos; Dokianakis, Emmanouil; Antoniou, Maria

    2015-10-01

    The efficacy of the in vitro cultivation of promastigotes of four Leishmania spp. was tested in the biphasic Novy-MacNeal-Nicolle (NNN) medium prepared using blood from different animals (horse, donkey, goat and sheep). The aim was to test which NNN preparation gave the best yield in the shortest time for different parasite species, in order to obtain a large crop of promastigotes for experimental work and for antigen preparation. Promastigotes of Leishmania infantum, Leishmania donovani, Leishmania tropica and Leishmania major, the four main parasite species occurring in the old world, were defrosted from -80 °C and placed, at equal numbers, in the 4 different NNN preparations. At the end of the 7th day, the NNN medium using horse blood produced the greatest number of promastigotes for all Leishmania spp. tested, whilst goat blood proved the poorest medium, providing culture results only for L. infantum. This finding may be explained by the fact that Leishmania is a nicotinamide adenine dinucleotide (NAD) auxotroph and horse erythrocytes support NAD-dependent microorganisms.

  19. Increased Abundance of Proteins Involved in Resistance to Oxidative and Nitrosative Stress at the Last Stages of Growth and Development of Leishmania amazonensis Promastigotes Revealed by Proteome Analysis

    PubMed Central

    Alonso, Ana; García-Tabares, Francisco; Mena, María C.; Ciordia, Sergio; Larraga, Vicente

    2016-01-01

    Leishmania amazonensis is one of the major etiological agents of the neglected, stigmatizing disease termed american cutaneous leishmaniasis (ACL). ACL is a zoonosis and rodents are the main reservoirs. Most cases of ACL are reported in Brazil, Bolivia, Colombia and Peru. The biological cycle of the parasite is digenetic because sand fly vectors transmit the motile promastigote stage to the mammalian host dermis during blood meal intakes. The amastigote stage survives within phagocytes of the mammalian host. The purpose of this study is detection and identification of changes in protein abundance by 2DE/MALDI-TOF/TOF at the main growth phases of L. amazonensis promastigotes in axenic culture and the differentiation process that takes place simultaneously. The average number of proteins detected per gel is 202 and the non-redundant cumulative number is 339. Of those, 63 are differentially abundant throughout growth and simultaneous differentiation of L. amazonensis promastigotes. The main finding is that certain proteins involved in resistance to nitrosative and oxidative stress are more abundant at the last stages of growth and differentiation of cultured L. amazonensis promastigotes. These proteins are the arginase, a light variant of the tryparedoxin peroxidase, the iron superoxide dismutase, the regulatory subunit of the protein kinase A and a light HSP70 variant. These data taken together with the decrease of the stress-inducible protein 1 levels are additional evidence supporting the previously described pre-adaptative hypothesis, which consists of preparation in advance towards the amastigote stage. PMID:27776144

  20. Increased Abundance of Proteins Involved in Resistance to Oxidative and Nitrosative Stress at the Last Stages of Growth and Development of Leishmania amazonensis Promastigotes Revealed by Proteome Analysis.

    PubMed

    Alcolea, Pedro J; Alonso, Ana; García-Tabares, Francisco; Mena, María C; Ciordia, Sergio; Larraga, Vicente

    2016-01-01

    Leishmania amazonensis is one of the major etiological agents of the neglected, stigmatizing disease termed american cutaneous leishmaniasis (ACL). ACL is a zoonosis and rodents are the main reservoirs. Most cases of ACL are reported in Brazil, Bolivia, Colombia and Peru. The biological cycle of the parasite is digenetic because sand fly vectors transmit the motile promastigote stage to the mammalian host dermis during blood meal intakes. The amastigote stage survives within phagocytes of the mammalian host. The purpose of this study is detection and identification of changes in protein abundance by 2DE/MALDI-TOF/TOF at the main growth phases of L. amazonensis promastigotes in axenic culture and the differentiation process that takes place simultaneously. The average number of proteins detected per gel is 202 and the non-redundant cumulative number is 339. Of those, 63 are differentially abundant throughout growth and simultaneous differentiation of L. amazonensis promastigotes. The main finding is that certain proteins involved in resistance to nitrosative and oxidative stress are more abundant at the last stages of growth and differentiation of cultured L. amazonensis promastigotes. These proteins are the arginase, a light variant of the tryparedoxin peroxidase, the iron superoxide dismutase, the regulatory subunit of the protein kinase A and a light HSP70 variant. These data taken together with the decrease of the stress-inducible protein 1 levels are additional evidence supporting the previously described pre-adaptative hypothesis, which consists of preparation in advance towards the amastigote stage.

  1. In vitro antileishmanial activity of three saponins isolated from ivy, alpha-hederin, beta-hederin and hederacolchiside A(1), in association with pentamidine and amphotericin B.

    PubMed

    Ridoux, O; Di Giorgio, C; Delmas, F; Elias, R; Mshvildadze, V; Dekanosidze, G; Kemertelidze, E; Balansard, G; Timon-David, P

    2001-06-01

    The in vitro antileishmanial activity of three saponins isolated from ivy, alpha-hederin, beta-hederin and hederacolchiside A(1), was investigated on parasites of the species Leishmania mexicana, in their promastigote and amastigote forms compared with their toxicity versus human monocytes. The results showed that saponins exhibited a strong antiproliferative activity on all stages of development of the parasite but demonstrated a strong toxicity versus human cells. Association of subtoxic concentrations of saponins with antileishmanial drugs such as pentamidine and amphotericin B demonstrated that saponins could enhance the efficiency of conventional drugs on both the promastigote and the amastigote stages of development of the parasite. The results demonstrated moreover that the action of saponins on promastigote membrane was cumulative with those of amphotericin B.

  2. In vitro infectivity and differential gene expression of Leishmania infantum metacyclic promastigotes: negative selection with peanut agglutinin in culture versus isolation from the stomodeal valve of Phlebotomus perniciosus.

    PubMed

    Alcolea, Pedro J; Alonso, Ana; Degayón, María A; Moreno-Paz, Mercedes; Jiménez, Maribel; Molina, Ricardo; Larraga, Vicente

    2016-05-20

    Leishmania infantum is the protozoan parasite responsible for zoonotic visceral leishmaniasis in the Mediterranean basin. A recent outbreak in humans has been reported in this area. The life cycle of the parasite is digenetic. The promastigote stage develops within the gut of phlebotomine sand flies, whereas amastigotes survive and multiply within phagolysosomes of mammalian host phagocytes. The major vector of L. infantum in Spain is Phlebotomus perniciosus. The axenic culture model of promastigotes is generally used because it is able to mimic the conditions of the natural environment (i.e. the sand fly vector gut). However, infectivity decreases with culture passages and infection of laboratory animals is frequently required. Enrichment of the stationary phase population in highly infective metacyclic promastigotes is achieved by negative selection with peanut agglutinin (PNA), which is possible only in certain Leishmania species such as L. major and L. infantum. In this study, in vitro infectivity and differential gene expression of cultured PNA-negative promastigotes (Pro-PNA(-)) and metacyclic promastigotes isolated from the sand fly anterior thoracic midgut (Pro-Pper) have been compared. In vitro infectivity is about 30 % higher in terms of rate of infected cells and number of amastigotes per infected cell in Pro-Pper than in Pro-PNA(-). This finding is in agreement with up-regulation of a leishmanolysin gene (gp63) and genes involved in biosynthesis of glycosylinositolphospholipids (GIPL), lipophosphoglycan (LPG) and proteophosphoglycan (PPG) in Pro-Pper. In addition, differences between Pro-Pper and Pro-PNA(-) in genes involved in important cellular processes (e.g. signaling and regulation of gene expression) have been found. Pro-Pper are significantly more infective than peanut lectin non-agglutinating ones. Therefore, negative selection with PNA is an appropriate method for isolating metacyclic promastigotes in stationary phase of axenic culture but it

  3. Participation of heparin binding proteins from the surface of Leishmania (Viannia) braziliensis promastigotes in the adhesion of parasites to Lutzomyia longipalpis cells (Lulo) in vitro

    PubMed Central

    2012-01-01

    Background Leishmania (V.) braziliensis is a causative agent of cutaneous leishmaniasis in Brazil. During the parasite life cycle, the promastigotes adhere to the gut of sandflies, to avoid being eliminated with the dejection. The Lulo cell line, derived from Lutzomyia longipalpis (Diptera: Psychodidae), is a suitable in vitro study model to understand the features of parasite adhesion. Here, we analyze the role of glycosaminoglycans (GAGs) from Lulo cells and proteins from the parasites in this event. Methods Flagellar (Ff) and membrane (Mf) fractions from promastigotes were obtained by differential centrifugation and the purity of fractions confirmed by western blot assays, using specific antibodies for cellular compartments. Heparin-binding proteins (HBP) were isolated from both fractions using a HiTrap-Heparin column. In addition, binding of promastigotes to Lulo cells or to a heparin-coated surface was assessed by inhibition assays or surface plasmon resonance (SPR) analysis. Results The success of promastigotes subcellular fractionation led to the obtainment of Ff and Mf proteins, both of which presented two main protein bands (65.0 and 55.0kDa) with affinity to heparin. The contribution of HBPs in the adherence of promastigotes to Lulo cells was assessed through competition assays, using HS or the purified HBPs fractions. All tested samples presented a measurable inhibition rate when compared to control adhesion rate (17 ± 2.0% of culture cells with adhered parasites): 30% (for HS 20μg/ml) and 16% (for HS 10μg/ml); HBP Mf (35.2% for 10μg/ml and 25.4% for 20μg/ml) and HBP Ff (10.0% for 10μg/ml and 31.4% for 20μg/ml). Additionally, to verify the presence of sulfated GAGs in Lulo cells surface and intracellular compartment, metabolic labeling with radioactive sulfate was performed, indicating the presence of an HS and chondroitin sulfate in both cell sections. The SPR analysis performed further confirmed the presence of GAGs ligands on L. (V

  4. Ecto-Nucleotidase Activities of Promastigotes from Leishmania (Viannia) braziliensis Relates to Parasite Infectivity and Disease Clinical Outcome

    PubMed Central

    Leite, Pauline M.; Gomes, Rodrigo S.; Figueiredo, Amanda B.; Serafim, Tiago D.; Tafuri, Wagner L.; de Souza, Carolina C.; Moura, Sandra A. L.; Fietto, Juliana L. R.; Melo, Maria N.; Ribeiro-Dias, Fátima; Oliveira, Milton A. P.; Rabello, Ana; Afonso, Luís C. C.

    2012-01-01

    Background Leishmania (Viannia) braziliensis has been associated with a broad range of clinical manifestations ranging from a simple cutaneous ulcer to destructive mucosal lesions. Factors leading to this diversity of clinical presentations are not clear, but parasite factors have lately been recognized as important in determining disease progression. Given the fact that the activity of ecto-nucleotidases correlates with parasitism and the development of infection, we evaluated the activity of these enzymes in promastigotes from 23 L. braziliensis isolates as a possible parasite-related factor that could influence the clinical outcome of the disease. Methodology/Principal Findings Our results show that the isolates differ in their ability to hydrolyze adenine nucleotides. Furthermore, we observed a positive correlation between the time for peak of lesion development in C57BL/6J mice and enzymatic activity and clinical manifestation of the isolate. In addition, we found that L. (V.) braziliensis isolates obtained from mucosal lesions hydrolyze higher amounts of adenine nucleotides than isolates obtained from skin lesions. One isolate with high (PPS6m) and another with low (SSF) ecto-nucleotidase activity were chosen for further studies. Mice inoculated with PPS6m show delayed lesion development and present larger parasite loads than animals inoculated with the SSF isolate. In addition, PPS6m modulates the host immune response by inhibiting dendritic cell activation and NO production by activated J774 macrophages. Finally, we observed that the amastigote forms from PPS6m and SSF isolates present low enzymatic activity that does not interfere with NO production and parasite survival in macrophages. Conclusions/Significance Our data suggest that ecto-nucleotidases present on the promastigote forms of the parasite may interfere with the establishment of the immune response with consequent impaired ability to control parasite dissemination and this may be an important

  5. Evaluation of Apoptotic and Antileishmanial Activities of Artemisinin on Promastigotes and BALB/C Mice Infected with Leishmania major

    PubMed Central

    GHAFFARIFAR, Fatemeh; ESAVAND HEYDARI, Farzad; DALIMI, Abdolhosein; HASSAN, Zuhair M.; DELAVARI, Mahdi; MIKAEILOO, Hajar

    2015-01-01

    Background: In leishmaniasis, some drugs prescribed for treatment have toxic effects and there are reports about drug resistance in some countries. Due to this fact, using herbal drugs such as artemisinin with good efficacy and low toxic effect might be suitable. Methods: We evaluated the apoptotic effect of artemisinin on Leishmania major in vitro and the antileishmanial activities of artemisinin on leishmaniasis in BALB/c mice and at the end INF-γ and IL-4 cytokines levels were detected by ELISA in spleen cell culture supernatants. During treatment the lesion size and survival rate were measured each four and ten days, respectively. Results: Percentage of early and late apoptosis in promastigotes of control group and promastigotes treated with 10, 25, 50 and 100 μg/ml of artemisinin after 48 h were 0.13, 16.04, 41.23, 49.03 and 81.83, respectively. The IFN-γ in ointment treated group were higher than those of other groups (P<0.05). The in vivo results showed that ointment compounds healed the lesions more effectively rather than intraperitoneal injection method (P<0.05). The survival rate of mice 150 days after challenge in treated group with ointment of artemisinin was 66% while all mice in control groups were died. Conclusion: All of in vitro results represented that this drug had antileishmanial effects and these results were confirmed by evaluation effects in vivo condition of leishmaniasis. Interestingly, according to these results it can be concluded that this drug has antileishmanial effects in vitro and in vivo conditions. Artemisinin induces cytotoxic effect on L. major via apoptosis-related mechanism. PMID:26246824

  6. Granulocyte-macrophage colony-stimulating factor increases the infectivity of Leishmania amazonensis by protecting promastigotes from heat-induced death.

    PubMed Central

    Barcinski, M A; Schechtman, D; Quintao, L G; Costa, D de A; Soares, L R; Moreira, M E; Charlab, R

    1992-01-01

    We have studied the effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on the infectivity of promastigotes of Leishmania amazonensis, an obligate intramacrophage parasite. We measured the capacity of the promastigotes to infect macrophages after preincubation at different temperatures (28, 34, and 37 degrees C) with recombinant murine GM-CSF, as well as the effect of an anti-murine GM-CSF antibody on the in vitro and in vivo infectivity of the parasite. GM-CSF increases the capacity of the promastigotes to infect cells when preincubated at 34 and 37 degrees C, whereas the anti-GM-CSF antibody exerts the opposite effect: it decreases the internalization rate and the progression of infection in macrophage cultures and slows the growth of the lesion in infected BALB/c mice. Neither of the described effects were observed when the in vitro and in vivo infections were made with amastigotes. Promastigotes die in a time-dependent manner when incubated at temperatures higher than 28 degrees C in the absence of GM-CSF. They are protected from this heat-induced death by incubation with the recombinant hormone. Our interpretation of these data is that the increase in the infectivity of promastigotes when incubated with GM-CSF at the temperatures at which infection occurs (34 and 37 degrees C) is due to the larger number of surviving forms within the infecting population. The decrease in infectivity when they are incubated with the antibody is due to inhibition of the protection conferred by the GM-CSF produced by the macrophages during the in vitro and in vivo infections. PMID:1500159

  7. [Review by expert group in the diagnosis and treatment of anemia in pregnant women. Federación Mexicana de Colegios de Obstetricia y Ginecología].

    PubMed

    Montoya Romero, Jose de Jesús; Castelazo Morales, Ernesto; Valerio Castro, Emilio; Velázquez Cornejo, Gerardo; Nava Muñoz, David Antonio; Escárcega Preciado, Jaime Arturo; Montoya Cossío, Javier; Pichardo Villalón, Guadalupe Mireya; Maldonado Aragón, Aristeo; Santana García, Héctor Rogelio; Fajardo Dueñas, Sergio; Mondragón Galindo, César Germán; García Lee, Teresa; García, Angel; Hernández de Morán, Marcela; Chávez Güitrón, Luis Eduardo; Jiménez Gutiérrez, Carlos

    2012-09-01

    According to data from the World Health Organization and UNICEF from year 2009, iron deficiency is the most widespread nutritional deficiency worldwide. This deficiency causes an imbalance between needs and iron supply, which consequently results in anemia. Around the world, two million people suffer from anemia, half of which is due to iron deficiency. The most impacted groups are children and teenagers, due to their highest requirements derived from the growing process, and women in their reproductive age, due to their loss of iron derived from menstruating or to their highest iron needs during pregnancy. This increase in needs is not satisfied by the regular diet, since it includes an insufficient amount and/or low bioavailability of iron. To share with the medical community treating pregnant women the experience of an expert group so that they always bear in mind the repercussions caused by anemia during pregnancy, know more about the diagnostic possibilities and have a reference point for prescribing iron supplements. The consensus method was used through the expert panel group technique. Two rounds were taken for structuring the clinical questions. The first one was to facilitate working groups their focusing in the clinical topics and the population of interest; the second one was to aid in posing specific questions observing the Patient, Intervention, Compare and Outcome (PICO) structure. The primary and clinical secondary study variables were defined by the working groups from the previously developed questions and during the face-to-face working period, according to the natural history of the disease: risk factors, diagnostic classification, (either pharmacological or non pharmacological) treatment and prognosis. The level of evidence and clinical recommendation was classified based on the Evidence Classification Level and Clinical Recommendation of the Medicine Group based on Evidence from Oxford University. In Mexico, 20.6% of pregnant women suffer from anemia, especially those between 15 and 16 years old, who prevail in 42.4% and 34.3% percent, respectively. Almost half the cases are due to iron deficiency. This type of anemia is associated with a higher risk of pre-term delivery, of low birth weight and perinatal death. The first assessment of an anemic pregnant woman shall include the medical history, a physical examination and the quantification of the erythrocyte indices, serum concentrations of iron and ferritin. The measurement of this last one has the highest sensitivity and specificity for diagnosing iron deficiency. Daily oral iron supplementation, at a 60-to-120 mg dosage, may correct most of mild-to-moderate anemias. The most appropriate treatment is with iron salts (iron sulfate, polimaltose iron complex or iron fumarate). In case of intolerance to iron sulfate or fumarate, polimaltose iron is a better tolerated option. Treatment shall be administered until the hemoglobin values are > 10.5 g and ferritin is between 300 and 360 microg/dL, and such levels shall be observed for at least one year. Parenteral administration is an alternative for patients with a severe intolerance to oral administration; even when the possibility of anaphylaxis shall be considered it is lower when using ferrous sacarate. Transfusion is reserved for patients with hemoglobin lower than 7 g/dL or having an imminent cardio-respiratory decompensation. Iron deficiency is the highest prevailing nutritional deficiency worldwide and its consequences during pregnancy may be highly risky for both the mother and her child. Anemia diagnosis may easily be achieved through a blood analysis including the serum ferritin determination. Serum iron measurement shall not be used as the only marker to set the diagnosis. It is important to rule out other causes, in addition to the deficiencies, which produce anemia in a patient. It is essential to suggest the administration of iron supplements not only during the antenatal period but also after birth o even after a miscarriage to fulfill the need for depleted iron. In severe anemias (hemoglobin being lower than 9.0 g/L), iron doses higher than 120 mg a day may be required. Treatment shall always begin orally, and if this is not well tolerated, parenteral administration shall be used.

  8. [Septic abortion in the Hospital de Ginecología y Obstetricia no. 3 del Instituto Mexicana de Seguridad Social. Late and early morbidity].

    PubMed

    López Ortiz, E; Sandoval Sevilla, S; Arteaga, V M; Rosas Arceo, J; Ortíz Arroyo, R

    1974-02-01

    268 cases of septic abortion which occurred between 1964-72 in a large metropolitan hospital in Mexico were analyzed retrospecively. There cases represented 0.88% of all cases of abortion during the same time. Most patients were between 21-30, and 48% with parity 2-5; 63% were at their first abortion; only 16 patients declared to have attempted abortion, and most cases were first trimester abortion. Pre- and postoperative procedures and vital signs were carefully taken, and time elapsed from medical treatment to surgery was 4-12 hours. There were 237 curettages, and 28 hysterectomies. Complication from surgery were 4.1%; there were 19 deaths, i.e. 7.5% of patients, of which 10 only 24 hours after hospitalization. Protocol of treatment of septic abortion is discussed, and surgical treatment highly recommended.

  9. Migrant Mexican Traditions = Tradiciones Migrantes Mexicanas. An Exhibit of Folk Art by Mexican Migrant Farmworkers (Geneseo, New York, September 22-October 4, 1990).

    ERIC Educational Resources Information Center

    Camacho, Juana; Gomez, Jose Luis

    This exhibit guide (in Spanish, with translation in English printed on adjoining columns on each page), describes an exhibition of folk art by Mexican migrant farmworkers presented by thre Folk Arts Program of the BOCES Geneseo Migrant Center. The exhibit is divided into four major themes that farmworkers presented by the BOCES Geneseo Migrant…

  10. Migrant Mexican Traditions = Tradiciones Migrantes Mexicanas. An Exhibit of Folk Art by Mexican Migrant Farmworkers (Geneseo, New York, September 22-October 4, 1990).

    ERIC Educational Resources Information Center

    Camacho, Juana; Gomez, Jose Luis

    This exhibit guide (in Spanish, with translation in English printed on adjoining columns on each page), describes an exhibition of folk art by Mexican migrant farmworkers presented by thre Folk Arts Program of the BOCES Geneseo Migrant Center. The exhibit is divided into four major themes that farmworkers presented by the BOCES Geneseo Migrant…

  11. Proposals to conserve the names Balansia claviceps against Ephelis mexicana,……,and Tolypocladium inflatum against Cordyceps subsessilis (Ascomycota: Sordariomycetes: Hypocreales)

    USDA-ARS?s Scientific Manuscript database

    In the course of updating the scientific names of plant-associated fungi in the U.S. National Fungus Collections Databases to conform with the requirement of one scientific name for each fungal species, several scientific names currently in use were identified that should be changed to the oldest ep...

  12. A new experimental culture medium for cultivation of Leishmania amazonensis: its efficacy for the continuous in vitro growth and differentiation of infective promastigote forms.

    PubMed

    Rodrigues, Igor de Almeida; da Silva, Bianca Alcântara; dos Santos, André Luis Souza; Vermelho, Alane Beatriz; Alviano, Celuta Sales; Dutra, Patrícia Maria Lourenço; Rosa, Maria do Socorro Santos

    2010-04-01

    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 rapid, inexpensive and reliable monophasic culture medium. The novel medium, designated PBHIL, promoted an excellent parasite growth, generating high quantities of promastigotes with long-term viability, and was able to induce cellular differentiation of L. amazonensis promastigotes to the amastigote-like forms (93%). Additionally, we reported the influence of this novel medium on the biochemical characteristics of L. amazonensis and on the interaction of this parasite parasites with mammalian macrophages.

  13. Replication Attempt: “Effect of BMAP-28 Antimicrobial Peptides on Leishmania Major Promastigote and Amastigote Growth: Role of Leishmanolysin in Parasite Survival”

    PubMed Central

    Iorns, Elizabeth; Gunn, William; Erath, Jessey; Rodriguez, Ana; Zhou, Jian; Benzinou, Michael

    2014-01-01

    This study describes an attempt to replicate experiments from the paper “Effect of BMAP-28 Antimicrobial Peptides on Leishmania major Promastigote and Amastigote Growth: Role of Leishmanolysin in Parasite Survival,” which was submitted to the Reproducibility Initiative for independent validation. The cathelicidin bovine myeloid antimicrobial peptide 28 (BMAP-28) and its isomers were previously shown to have potent antiparasitic activity against Leishmania major. We tested the effectiveness of L-BMAP-28 and two of its isomers, the D-amino acid form (D-BMAP-28) and the retro-inverso form (RI-BMAP-28), in both unamidated and amidated forms, as anti-leishmanial agents against Leishmania major promastigotes in vitro. We observed that L-BMAP-28, as well as its D and RI isomers, demonstrate anti-leishmanial activity against L. major promastigotes in vitro. The inhibitory effect was lower than what was seen in the original study. At 2 µM of amidated peptides, the viability was 94%, 36%, and 66% with L-, D- and RI-peptides, versus 57%, 6%, and 18% in the original study. PMID:25517992

  14. Asteraceae Artemisia campestris and Artemisia herba-alba Essential Oils Trigger Apoptosis and Cell Cycle Arrest in Leishmania infantum Promastigotes

    PubMed Central

    Messaoud, Chokri; Haoues, Meriam; Neffati, Noura; Bassoumi Jamoussi, Imen; Essafi-Benkhadir, Khadija; Boussaid, Mohamed; Karoui, Habib

    2016-01-01

    We report the chemical composition and anti-Leishmania and antioxidant activity of Artemisia campestris L. and Artemisia herba-alba Asso. essential oils (EOs). Our results showed that these extracts exhibit different antioxidant activities according to the used assay. The radical scavenging effects determined by DPPH assay were of IC50 = 3.3 mg/mL and IC50 = 9.1 mg/mL for Artemisia campestris and Artemisia herba-alba essential oils, respectively. However, antioxidant effects of both essential oils, determined by ferric-reducing antioxidant power (FRAP) assay, were in the same range (2.3 and 2.97 mg eq EDTA/g EO, resp.), while the Artemisia herba-alba essential oil showed highest chelating activity of Fe2+ ions (27.48 mM Fe2+). Interestingly, we showed that both EOs possess dose-dependent activity against Leishmania infantum promastigotes with IC50 values of 68 μg/mL and 44 μg/mL for A. herba-alba and A. campestris, respectively. We reported, for the first time, that antileishmanial activity of both EOs was mediated by cell apoptosis induction and cell cycle arrest at the sub-G0/G1 phase. All our results showed that EOs from A. herba-alba and A. campestris plants are promising candidates as anti-Leishmania medicinal products. PMID:27807464

  15. Physalis angulata induces death of promastigotes and amastigotes of Leishmania (Leishmania) amazonensis via the generation of reactive oxygen species.

    PubMed

    Da Silva, B J M; Da Silva, R R P; Rodrigues, A P D; Farias, L H S; Do Nascimento, J L M; Silva, E O

    2016-03-01

    Leishmaniasis are a neglected group of emerging diseases that have been found in 98 countries and are caused by protozoa of the genus Leishmania. The therapy for leishmaniasis causes several side effects and leads to drug-resistant strains. Natural products from plants have exhibited activities against Leishmania in various experimental models. Physalis angulata is a widely used plant in popular medicine, and in the literature it has well-documented leishmanicidal activity. However, its mechanism of action is still unknown. Thus, this study aims to evaluate the mechanism driving the leishmanicidal activity of an aqueous extract of P. angulata root (AEPa). AEPa was effective against both promastigotes and intracellular amastigote forms of Leishmania amazonensis. This effect was mediated by an increase of reactive oxygen species (ROS), but not of nitric oxide (NO). The increased production of ROS induces cell death by phenotypes seems by apoptosis cell death in Leishmania, but not autophagy or necrosis. In addition, morphological analysis of macrophages showed that AEPa induced a high number of cytoplasmic projections, increased the volume of cytoplasm and number of vacuoles, caused cytoskeleton alterations and resulted in high spreading ability. AEPa also promoted superoxide anion (O2(-)) production in both uninfected macrophages and those infected with Leishmania. Therefore, these results revealed that AEPa causes cell death by phenotypes seems by apoptosis cell death in L. amazonensis and modulates macrophage activation through morphofunctional alterations and O2(-) generation to induce Leishmania death. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Toxicity of betulin derivatives and in vitro effect on promastigotes and amastigotes of Leishmania infantum and L. donovani.

    PubMed

    Wert, León; Alakurtti, Sami; Corral, María Jesús; Sánchez-Fortún, Sebastián; Yli-Kauhaluoma, Jari; Alunda, José María

    2011-07-01

    The toxicity and antileishmanial activity of 20 betulin derivatives were studied. The toxicity of betulin and synthesized compounds was determined using a bacterial test (Microtox) and two mammalian cell lines (CHO-K1 and J774). The antileishmanial activity of compounds (50  μM) was examined in both the promastigote and intracellular amastigote stages of Leishmania infantum and L. donovani. No correlation was found among the toxicity tests. All the compounds showed significant antipromastigote activity. The antiproliferative capacity of derivatives was dependent on the parasite stage studied, and no substantial differences were found between Leishmania species. Betulin, 3,28-di-O-acetylbetulin and L-aspartyl amide of betulonic acid showed moderate activity against amastigotes. The highest inhibition of intracellular amastigote multiplication was achieved with a low micromolar concentration (IC(50) ca 9  μM) of heterocyclic betulin derivative 3,28-di-O-acetyllup-13(18)-ene with N-ethyltriazolo moiety 16, without significant toxicity for mammalian cells. These results point to the interest of this lead compound for further in vitro and in vivo tests.

  17. Interaction between Miltefosine and Amphotericin B: Consequences for Their Activities towards Intestinal Epithelial Cells and Leishmania donovani Promastigotes In Vitro▿

    PubMed Central

    Ménez, Cécile ; Buyse, Marion; Besnard, Madeleine; Farinotti, Robert; Loiseau, Philippe M.; Barratt, Gillian

    2006-01-01

    The aim of this study was to evaluate the potential of a combination of two antileishmanial drugs, miltefosine (HePC) and amphotericin B (AMB), when administered by the oral route. Caco-2 cell monolayers were used as a validated in vitro model of the intestinal barrier and Leishmania donovani promastigotes as a model for evaluating the effect of the drug combination. Spectroscopic measurements demonstrated that HePC and AMB associate, leading to the formation of mixed aggregates in which AMB is solubilized as monomers. The incubation of the association of HePC and AMB with Caco-2 cell monolayers, at a concentration higher than 5 μM, led to (i) a reduction of the HePC-induced paracellular permeability enhancement in Caco-2 cell monolayers, (ii) an inhibition of the uptake of both drugs, and (iii) a decrease in the transepithelial transport of both drugs, suggesting that a pharmacokinetic antagonism between HePC and AMB could occur after their oral administration. However, the combination did not exhibit any antagonism or synergy in its antileishmanial activity. These results demonstrated a strong physicochemical interaction between HePC and AMB, depending on the concentration of each, which could have important consequences for their biological activities, if they are administered together. PMID:16966395

  18. Antileishmanial activity of quinazoline derivatives: synthesis, docking screens, molecular dynamic simulations and electrochemical studies.

    PubMed

    Mendoza-Martínez, Cesar; Galindo-Sevilla, Norma; Correa-Basurto, José; Ugalde-Saldivar, Victor Manuel; Rodríguez-Delgado, Rosa Georgina; Hernández-Pineda, Jessica; Padierna-Mota, Cecilia; Flores-Alamo, Marcos; Hernández-Luis, Francisco

    2015-03-06

    A series of quinazoline-2,4,6-triamine were synthesized and evaluated in vitro against Leishmania mexicana. Among them, N(6)-(ferrocenmethyl)quinazolin-2,4,6-triamine (H2) showed activity on promastigotes and intracellular amastigotes, as well as low cytotoxicity in mammalian cells. Docking and electrochemical studies showed the importance of both the ferrocene and the heterocyclic nucleus to the observed activity. H2 is readily oxidized electrochemically, indicating that the mechanism of action probably involves redox reactions. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  19. In vitro study of the photodynamic antimicrobial therapy (PACT) against promastigotes form of the leishmania (viannia) braziliensis: in vitro study

    NASA Astrophysics Data System (ADS)

    Barbosa, Artur F. S.; Sangiorgi, Bruno B.; Galdino, Suely L.; Pitta, Ivan R.; Barral-Netto, Manoel; Pinheiro, Antônio L. B.

    2013-03-01

    Leishmaniasis, a protozoan parasitic disease that remains a major worldwide health problem with high endemicity in developing countries. Treatment of cutaneous Leishmaniasis (CL) should be decided by the clinical lesions, etiological species and its potential to develop into mucosal Leishmaniasis. High cost, systemic toxicity, and diminished efficacy due to development of parasite resistance are the serious drawbacks of current treatment options. Thus, identifying new, effective, and safer anti-leishmanial drug(s) is of paramount importance. The aim of this study was to verify the effectiveness of PACT in vitro, as a new technique for the treatment of Leishmaniasis. For this, semiconductor laser (λ = 660nm, 40mW, 8.4J/cm2, CW) associated to phenothiazine's derivatives (5 and 10 μg/ml, TBO, Methylene Blue or Phenothiazine) on the promastigotes form of Leishmania braziliensis in a single session was used. Viability of the parasites was assessed in quadruplicates of each group. The samples were removed and analyzed in a hemocytometer 72h after PACT. We found an important decrease in the number of viable parasites on all treated groups in comparison to their controls. The results of present study showed significant percentage of lethality (above 92%) of the protocol. The 98.33% of lethality was achieved with 10 μg/ml of FTZ. No lethality was seen on groups treated neither with laser nor with each compounds separately. The results are promising and indicative that the use of PACT may be a powerful treatment of Leishmaniasis when compared to already available ones.

  20. Different Host Complement Systems and Their Interactions with Saliva from Lutzomyia longipalpis (Diptera, Psychodidae) and Leishmania infantum Promastigotes

    PubMed Central

    Mendes-Sousa, Antonio Ferreira; Nascimento, Alexandre Alves Sousa; Queiroz, Daniel Costa; Vale, Vladimir Fazito; Fujiwara, Ricardo Toshio; Araújo, Ricardo Nascimento; Pereira, Marcos Horácio; Gontijo, Nelder Figueiredo

    2013-01-01

    Background Lutzomyia longipalpis is the vector of Leishmania infantum in the New World, and its saliva inhibits classical and alternative human complement system pathways. This inhibition is important in protecting the insect´s midgut from damage by the complement. L. longipalpis is a promiscuous blood feeder and must be protected against its host’s complement. The objective of this study was to investigate the action of salivary complement inhibitors on the sera of different host species, such as dogs, guinea pigs, rats and chickens, at a pH of 7.4 (normal blood pH) and 8.15 (the midgut pH immediately after a blood meal). We also investigated the role of the chicken complement system in Leishmania clearance in the presence and absence of vector saliva. Results The saliva was capable of inhibiting classical pathways in dogs, guinea pigs and rats at both pHs. The alternative pathway was not inhibited except in dogs at a pH of 8.15. The chicken classical pathway was inhibited only by high concentrations of saliva and it was better inhibited by the midgut contents of sand flies. Neither the saliva nor the midgut contents had any effect on the avian alternative pathway. Fowl sera killed L. infantum promastigotes, even at a low concentration (2%), and the addition of L. longipalpis saliva did not protect the parasites. The high body temperature of chickens (40°C) had no effect on Leishmania viability during our assays. Conclusion Salivary inhibitors act in a species-specific manner. It is important to determine their effects in the natural hosts of Leishmania infantum because they act on canid and rodent complements but not on chickens (which do not harbour the parasite). Moreover, we concluded that the avian complement system is the probable mechanism through which chickens eliminate Leishmania and that their high body temperature does not influence this parasite. PMID:24255715

  1. Apoptosis-like death in Leishmania donovani promastigotes induced by eugenol-rich oil of Syzygium aromaticum.

    PubMed

    Islamuddin, Mohammad; Sahal, Dinkar; Afrin, Farhat

    2014-01-01

    Leishmaniasis consists of a complex spectrum of infectious diseases with worldwide distribution of which visceral leishmaniasis or kala-azar caused by Leishmania donovani is the most devastating. In the absence of vaccines, chemotherapy remains the mainstay for the control of leishmaniasis. The drugs of choice are expensive and associated with multiple adverse side effects. Because of these limitations, the development of new antileishmanial compounds is imperative and plants offer prospects in this regard. The present work was conducted to study the antileishmanial potential of oil from Syzygium aromaticum flower buds (clove). The S. aromaticum oil was characterized by gas chromatography and GC-MS and eugenol as well as eugenyl acetate were found to be the most abundant compounds, composing 59.75 % and 29.24 %, respectively of the oil. Our findings have shown that eugenol-rich essential oil from S. aromaticum (EROSA) possesses significant activity against L. donovani, with 50 % inhibitory concentration of 21 ± 0.16 µg ml(-1) and 15.24 ± 0.14 µg ml(-1), respectively, against promastigotes and intracellular amastigotes. Alterations in cellular morphology and growth reversibility assay substantiated the leishmanicidal activity of EROSA. The leishmanicidal effect was mediated via apoptosis as confirmed by externalization of phosphatidylserine, DNA nicking by TdT-mediated dUTP nick-end labelling (TUNEL) assay, dyskinetoplastidy, cell cycle arrest at sub-G0-G1 phase, loss of mitochondrial membrane potential and reactive oxygen species generation. EROSA presented no adverse cytotoxic effects against murine macrophages even at 200 µg ml(-1). Our studies authenticate the promising antileishmanial activity of EROSA, which is mediated by programmed cell death, and, accordingly, EROSA may be a source of novel agents for the treatment of leishmaniasis.

  2. Evaluation of photodynamic antimicrobial therapy (PACT) against promastigotes form of the Leishmania (Viannia) braziliensis: in vitro study

    NASA Astrophysics Data System (ADS)

    Barbosa, Artur F. S.; Sangiorgi, Bruno B.; Galdino, Suely L.; Pitta, Ivan R.; Barral Netto, Manoel; Correia, Neandder A.; Pinheiro, Antônio L. B.

    2012-03-01

    Leishmaniasis is a complex disease that affects more than 12 million people in 88 countries worldwide. Leishmania (Viannia) braziliensis is the most common species in the Americas and the most important causative agent of cutaneous and mucocutaneous leishmaniasis in Brazil. The therapeutic arsenal routinely employed to treat patients with leishmaniasis is limited and unsatisfactory. For cutaneous leishmaniasis, pentavalent antimonials are the first line therapeutic scheme recommended by the WHO. These compounds are highly toxic, poorly tolerated and their effectiveness highly variable. In this work, a technique with, so far, an unknown disadvantage is discussed. The aim of this study was to verify the effectiveness of PACT in vitro, as a new technique for the treatment of Leishmaniasis. For this, semiconductor laser (λ = 660nm, 40mW, 4.2J/cm2, CW) associated to phenothiazine's derivatives (5 and 10 μg/ml, TBO, Methylene Blue or Phenothiazine) on the promastigotes form of Leishmania braziliensis in a single session was used. Viability of the parasites was assessed in quadruplicates of each group. The samples were removed and analyzed in a hemocytometer 72h after PACT. We found an important decrease in the number of viable parasites on all treated groups in comparison to their controls. The results of present study showed significant percentage of lethality (above 95%) of the protocol. The 99.23% of lethality was achieved with 10 μg/ml of TBO. No lethality was seen on groups treated neither with laser nor with each compounds separately. The results are promising and indicative that the use of PACT may be a powerful treatment of leishmaniasis when compared to already available ones.

  3. Evaluation of Organelle Changes in Promastigotes of Unresponsive Leishmania Tropica to Meglumine Antimoniate in Comparison with Sensitive and Standard Isolates by Electron Microscopy

    PubMed Central

    Bahreini, Mitra; Bolorizadeh, Mehdi; Dabiri, Shahriar; Sharifi, Iraj

    2015-01-01

    Background: The control of leishmaniasis faces serious challenges because of resistance to the first-line antimonial drugs. We aimed to evaluate the differences in organelle changes of cultivated promastigotes obtained from skin lesions of sensitive and unresponsive isolates to meglumine antimoniate (Glucantime) by electron microscopy. Material and Methods: This study was done in Bam city, southeastern Iran, in which the incidence of disease has sharply increased since the earthquake in 2003. The samples were taken from 66 patients who were referred to the cutaneous leishmaniasis (CL) treatment center in Bam. A questionnaire was completed for each individual, recording their demographic characteristics and CL status. The scraping smears provided from the edge of active lesions with sterile blades were fixed with methanol, stained by Giemsa, and examined under a compound light microscope for amastigote form simultaneously. To prepare the specimens for transmission electron imaging, promastigotes were centrifuged and resuspened. Results: Transmission electron microscopic study of the cultivated promastigotes revealed that there were alterations in the organelles and structures of sensitive isolates compared with unresponsive and standard ones. Organelles and structures such as mitochondria, kinetoplast, microtubules, cytoplasmic vacuoles, plasma membrane and vesicles were studied. The alterations such as disintegration of kinetoplast into thin filaments and condensation of kinetoplast DNA core, changes in size, number and location of vesicles and microtubules were observed. We noted intense cytoplasmic vacuolization, and considerable swelling of mitochondria. Conclusion: The significance and relevance of these changes might help understand drug resistance patterns and help localize the best target site for inactivating the organism. PMID:26120175

  4. Sheep blood-LB agar base medium (SLM) as a simple and suitable medium for the cultivation of Leishmania major promastigotes.

    PubMed

    Nasiri, Vahid

    2013-11-01

    Several methods of cultivation of Leishmania parasites are available, and among them, biphasic media like Nicolle-Novy-MacNeal medium are considered to be superior for the initial isolation of the parasites and their in vivo infectivity. In the present work, the efficacy of sheep blood-LB agar base medium (SLM) was evaluated for the cultivation of Leishmania major promastigotes. The SLM supports the proliferation of the parasites and can be used for routine isolation and cultivation of Leishmania parasites with acceptable in vivo infectivity for research purposes.

  5. In Vitro Evaluation of a Soluble Leishmania Promastigote Surface Antigen as a Potential Vaccine Candidate against Human Leishmaniasis

    PubMed Central

    Bahi-Jaber, Narges; Petitdidier, Elodie; Markikou-Ouni, Wafa; Aoun, Karim; Moreno, Javier; Carrillo, Eugenia; Salotra, Poonam; Kaushal, Himanshu; Negi, Narender Singh; Arevalo, Jorge; Falconi-Agapito, Francesca; Privat, Angela; Cruz, Maria; Pagniez, Julie; Papierok, Gérard-Marie; Rhouma, Faten Bel Haj; Torres, Pilar; Lemesre, Jean-Loup; Chenik, Mehdi; Meddeb-Garnaoui, Amel

    2014-01-01

    PSA (Promastigote Surface Antigen) belongs to a family of membrane-bound and secreted proteins present in several Leishmania (L.) species. PSA is recognized by human Th1 cells and provides a high degree of protection in vaccinated mice. We evaluated humoral and cellular immune responses induced by a L. amazonensis PSA protein (LaPSA-38S) produced in a L. tarentolae expression system. This was done in individuals cured of cutaneous leishmaniasis due to L. major (CCLm) or L. braziliensis (CCLb) or visceral leishmaniasis due to L. donovani (CVLd) and in healthy individuals. Healthy individuals were subdivided into immune (HHR-Lm and HHR-Li: Healthy High Responders living in an endemic area for L. major or L. infantum infection) or non immune/naive individuals (HLR: Healthy Low Responders), depending on whether they produce high or low levels of IFN-γ in response to Leishmania soluble antigen. Low levels of total IgG antibodies to LaPSA-38S were detected in sera from the studied groups. Interestingly, LaPSA-38S induced specific and significant levels of IFN-γ, granzyme B and IL-10 in CCLm, HHR-Lm and HHR-Li groups, with HHR-Li group producing TNF-α in more. No significant cytokine response was observed in individuals immune to L. braziliensis or L. donovani infection. Phenotypic analysis showed a significant increase in CD4+ T cells producing IFN-γ after LaPSA-38S stimulation, in CCLm. A high positive correlation was observed between the percentage of IFN-γ-producing CD4+ T cells and the released IFN-γ. We showed that the LaPSA-38S protein was able to induce a mixed Th1 and Th2/Treg cytokine response in individuals with immunity to L. major or L. infantum infection indicating that it may be exploited as a vaccine candidate. We also showed, to our knowledge for the first time, the capacity of Leishmania PSA protein to induce granzyme B production in humans with immunity to L. major and L. infantum infection. PMID:24786587

  6. Antileishmanial activity of a mixture of Tridax procumbens and Allium sativum in mice

    PubMed Central

    Gamboa-Leon, Rubi; Vera-Ku, Marina; Peraza-Sanchez, Sergio R.; Ku-Chulim, Carlos; Horta-Baas, Aurelio; Rosado-Vallado, Miguel

    2014-01-01

    We tested a mixture of Tridax procumbens, known for its direct action against Leishmania mexicana, and Allium sativum, known for its immunomodulatory effect, as an alternative to treat cutaneous leishmaniasis. Acute oral toxicity was tested with the Up-and-Down Procedure (UDP) using a group of healthy mice administered with either T. procumbens or A. sativum extracts and compared with a control group. Liver injury and other parameters of toxicity were determined in mice at day 14. The in vivo assay was performed with mice infected with L. mexicana promastigotes and treated with either a mixture of T. procumbens and A. sativum or each extract separately. The thickness of the mice’s footpads was measured weekly. After the 12-week period of infection, blood samples were obtained by cardiac puncture to determine the total IgG, IgG1 and IgG2a immunoglobulins by a noncommercial indirect ELISA. We showed that the mixture of T. procumbens and A. sativum extracts was better at controlling L. mexicana infection while not being toxic when tested in the acute oral toxicity assay in mice. An increase in the ratio of IgG2a/IgG1 indicated a tendency to raise a Th1-type immune response in mice treated with the mixture. The mixture of T. procumbens and A. sativum extracts is a promising natural treatment for cutaneous leishmaniasis and its healing effects make it a good candidate for a possible new phytomedicine. PMID:24717526

  7. Antileishmanial activity of a mixture of Tridax procumbens and Allium sativum in mice.

    PubMed

    Gamboa-Leon, Rubi; Vera-Ku, Marina; Peraza-Sanchez, Sergio R; Ku-Chulim, Carlos; Horta-Baas, Aurelio; Rosado-Vallado, Miguel

    2014-01-01

    We tested a mixture of Tridax procumbens, known for its direct action against Leishmania mexicana, and Allium sativum, known for its immunomodulatory effect, as an alternative to treat cutaneous leishmaniasis. Acute oral toxicity was tested with the Up-and-Down Procedure (UDP) using a group of healthy mice administered with either T. procumbens or A. sativum extracts and compared with a control group. Liver injury and other parameters of toxicity were determined in mice at day 14. The in vivo assay was performed with mice infected with L. mexicana promastigotes and treated with either a mixture of T. procumbens and A. sativum or each extract separately. The thickness of the mice's footpads was measured weekly. After the 12-week period of infection, blood samples were obtained by cardiac puncture to determine the total IgG, IgG1 and IgG2a immunoglobulins by a noncommercial indirect ELISA. We showed that the mixture of T. procumbens and A. sativum extracts was better at controlling L. mexicana infection while not being toxic when tested in the acute oral toxicity assay in mice. An increase in the ratio of IgG2a/IgG1 indicated a tendency to raise a Th1-type immune response in mice treated with the mixture. The mixture of T. procumbens and A. sativum extracts is a promising natural treatment for cutaneous leishmaniasis and its healing effects make it a good candidate for a possible new phytomedicine.

  8. Effects of essential oils from Cymbopogon citratus (DC) Stapf., Lippia sidoides Cham., and Ocimum gratissimum L. on growth and ultrastructure of Leishmania chagasi promastigotes.

    PubMed

    Oliveira, Valéria C S; Moura, Daniela M S; Lopes, José A D; de Andrade, Paulo P; da Silva, Nicácio H; Figueiredo, Regina C B Q

    2009-04-01

    The current therapy for leishmaniasis, which affects annually about 2 million people, is far from satisfactory. All available drugs require parenteral administration and are potentially toxic. Plant essential oils have been traditionally used in folk medicine and appear as valuable alternative source for chemotherapeutic compounds. In this study, we demonstrated the effect of essential oils from Cymbopogon citratus, Lippia sidoides, and Ocimum gratissimum on growth and ultrastructure of Leishmania chagasi promastigote forms. Steam distillation was used to isolate the essential oils, and their constituents were characterized by gas chromatography coupled to mass spectrometry and nuclear magnetic resonance. All essential oils showed in vitro inhibitory action on L. chagasi promastigotes growth in a dose-dependent way, with IC(50)/72 h of 45, 89, and 75 microg/mL for C. citratus, L. sidoides, and O. gratissimum, respectively. Drastic morphological alterations were observed in all essential oil-treated parasites, including cell swelling, accumulation of lipid droplets in the cytoplasm, and increase of acidocalcisome volume. Furthermore, aberrant-shaped cells with multi-septate body were observed by scanning electron microscopy, suggesting an additional effect on cytokinesis. Taken together, our data show that these essential oils affect the parasite viability being the C. citratus essential oil the most effective against L. chagasi.

  9. In vitro effects of triterpenic acids from olive leaf extracts on the mitochondrial membrane potential of promastigote stage of Leishmania spp.

    PubMed

    Sifaoui, Ines; López-Arencibia, Atteneri; Martín-Navarro, Carmen Maria; Ticona, Juan Carlos; Reyes-Batlle, María; Mejri, Mondher; Jiménez, Antonio Ignacio; Lopez-Bazzocchi, Isabel; Valladares, Basilio; Lorenzo-Morales, Jacob; Abderabba, Manef; Piñero, José E

    2014-10-15

    Protozoan diseases, such as leishmaniasis, are a cause of considerable morbidity throughout the world, affecting millions every year. In this study, two triterpenic acids (maslinic and oleanolic acids) were isolated from Tunisian olive leaf extracts and their in vitro activity against the promastigotes stage of Leishmania (L.) infantum and Leishmania (L.) amazonensis was investigated. Maslinic acid showed the highest activity with an IC50 of 9.32 ± 1.654 and 12.460 ± 1.25 μg/ml against L. infantum and L. amazonensis, respectively. The mechanism of action of these drugs was investigated by detecting changes in the phosphatidylserine (PS) exposure, the plasma membrane permeability, the mitochondrial membrane potential and the ATP level production in the treated parasites. By using the fluorescent probe SYTOX® Green, both triterpenic acids showed that they produce a time-dependent plasma membrane permeabilization in the treated Leishmania species. In addition, spectrofluorimeteric data revealed the surface exposure of PS in promastigotes. Both molecules reduced the mitochondrial membrane potential and decreased the ATP levels to 15% in parasites treated with IC90 for 24h. We conclude that the triterpenic acids tested in this study, show potential as future therapeutic alternative against leishmaniasis. Further studies are needed to confirm this.

  10. In vivo monitoring of intracellular ATP levels in Leishmania donovani promastigotes as a rapid method to screen drugs targeting bioenergetic metabolism.

    PubMed

    Luque-Ortega, J R; Rivero-Lezcano, O M; Croft, S L; Rivas, L

    2001-04-01

    A method for the rapid screening of drugs targeting the bioenergetic metabolism of Leishmania spp. was developed. The system is based on the monitoring of changes in the intracellular ATP levels of Leishmania donovani promastigotes that occur in vivo, as assessed by the luminescence produced by parasites transfected with a cytoplasmic form of Phothinus pyralis luciferase and incubated with free-membrane permeable D-luciferin analogue D-luciferin-[1-(4,5-dimethoxy-2-nitrophenyl) ethyl ester]. A significant correlation was obtained between the rapid inhibition of luminescence with parasite proliferation and the dissipation of changes in mitochondrial membrane potential (DeltaPsi(m)) produced by buparvaquone or plumbagin, two leishmanicidal inhibitors of oxidative phosphorylation. To further validate this test, a screen of 14 standard leishmanicidal drugs, using a 50 microM cutoff, was carried out. Despite its semiquantitative properties and restriction to the promastigote stage, this test compares favorably with other bioenergetic parameters with respect to time and cell number requirements for the screening of drugs that affect mitochondrial activity.

  11. Studies on the protective efficacy of freeze thawed promastigote antigen of Leishmania donovani along with various adjuvants against visceral leishmaniasis infection in mice.

    PubMed

    Thakur, Ankita; Kaur, Harpreet; Kaur, Sukhbir

    2015-09-01

    Visceral leishmaniasis (VL) caused by Leishmania donovani persists as a major public health issue in tropical and subtropical areas of the world. Current treatment of this disease relies on use of drugs. It is doubtful that chemotherapy can alone eradicate the disease, so there is a need for an effective vaccine. Killed antigen candidates remain a good prospect considering their ease of formulation, stability, low cost and safety. To enhance the efficacy of killed vaccines suitable adjuvant and delivery system are needed. Therefore, the current study was conducted to determine the protective efficacy of freeze-thawed L. donovani antigen in combination with different adjuvants against experimental infection of VL. For this, BALB/c mice were immunized thrice at an interval of two weeks. Challenge infection was given two weeks after last immunization. Mice were sacrificed after last immunization and on different post challenge/infection days. Immunized mice showed significant reduction in parasite burden, enhanced DTH responses with increased levels of Th1 cytokines and lower levels of Th2 cytokines, thus indicating the development of a protective Th1 response. Maximum protection was achieved with liposome encapsulated freeze thawed promastigote (FTP) antigen of L. donovani and it was followed by group immunized with FTP+MPL-A, FTP+saponin, FTP+alum and FTP antigen (alone). The present study highlights greater efficacy of freeze thawed promastigote antigen as a potential vaccine candidate along with effective adjuvant formulations against experimental VL infection.

  12. The Genus Ixodes (Acari: Ixodidae) in Mexico: Adult Identification Keys, Diagnoses, Hosts, and Distribution

    DTIC Science & Technology

    2010-01-01

    Revista Mexicana de Biodiversidad 81: 289- 298, 2010 Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection...I. tovari Revista Mexicana de Biodiversidad 80: 289- 298, 2010 291 19. Auriculae broadly rounded...Cornua and auriculae absent; hypostome Christmas tree-shaped, dentition 3/3; coxa Revista Mexicana de Biodiversidad 80: 289- 298, 2010

  13. Ultrastructural and Biochemical Alterations Induced by 22,26-Azasterol, a Δ24(25)-Sterol Methyltransferase Inhibitor, on Promastigote and Amastigote Forms of Leishmania amazonensis

    PubMed Central

    Rodrigues, Juliany C. F.; Attias, Márcia; Rodriguez, Carlos; Urbina, Julio A.; Souza, Wanderley de

    2002-01-01

    We report on the antiproliferative effects and the ultrastructural and biochemical alterations induced in vitro by 22,26-azasterol, a sterol Δ24(25)-methyltransferase (24-SMT) inhibitor, on Leishmania amazonensis. When promastigotes and amastigotes were exposed to 100 nM 22,26-azasterol, complete growth arrest and cell lysis ensued after 72 (promastigotes) or 120 (amastigotes) h. Exposure of parasites to this azasterol led to the complete depletion of parasite endogenous sterols (episterol and 5-dehydroepisterol) and their replacement by 24-desalkyl sterols (zymosterol, cholesta-5,7,24-trien-3β-ol, and cholesta-7,24-dien-3β-ol), while 14-methyl-zymosterol and 4,14-dimethyl-zymosterol accumulated as a result of simultaneous incubation of the parasites with 22,26-azasterol and ketoconazole, a known inhibitor of the parasite’s sterol C14-demethylase. These results confirmed that 24-SMT is the primary site of action of the azasterol. Profound changes were also observed in the phospholipid compositions of treated cells, in which a twofold reduction in the content of phosphatidylserine was observed; this was accompanied by a concomitant increase in the content of phosphatidylinositol. Transmission electron microscopy showed that 22,26-azasterol induced marked morphological changes, including mitochondrial swelling, invaginations of the inner mitochondrial membrane, and the appearance of large bodies containing concentric membranes. Other modifications included increases in the numbers of acidocalcisomes, megasomes, and lipid inclusions and the appearance of typical autophagic structures and cell body protrusions toward the flagellar pocket. We conclude that the dramatic alteration of the lipid composition of the parasite’s membranes induced by the drug underlies the ultrastructural alterations that lead to the loss of cell viability and that 24-SMT inhibitors could be useful as selective antileishmanial agents. PMID:11796362

  14. Leishmania promastigotes evade interleukin 12 (IL-12) induction by macrophages and stimulate a broad range of cytokines from CD4+ T cells during initiation of infection

    PubMed Central

    1994-01-01

    Leishmania major are intramacrophage parasites whose eradication requires the induction of T helper 1 (Th1) effector cells capable of activating macrophages to a microbicidal state. Interleukin 12 (IL-12) has been recently identified as a macrophage-derived cytokine capable of mediating Th1 effector cell development, and of markedly enhancing interferon gamma (IFN-gamma) production by T cells and natural killer cells. Infection of macrophages in vitro by promastigotes of L. major caused no induction of IL-12 p40 transcripts, whereas stimulation using heat-killed Listeria or bacterial lipopolysaccharide induced readily detectable IL-12 mRNA. Using a competitor construct to quantitate a number of transcripts, a kinetic analysis of cytokine induction during the first few days of infection by L. major was performed. All strains of mice examined, including susceptible BALB/c and resistant C57BL/6, B10.D2, and C3H/HeN, had the appearance of a CD4+ population in the draining lymph nodes that contained transcripts for IL-2, IL-4, and IFN- gamma (and in some cases, IL-10) that peaked 4 d after infection. In resistant mice, the transcripts for IL-2, IL-4, and IL-10 were subsequently downregulated, whereas in susceptible BALB/c mice, these transcripts were only slightly decreased, and IL-4 continued to be reexpressed at high levels. IL-12 transcripts were first detected in vivo by 7 d after infection, consistent with induction by intracellular amastigotes. Challenge of macrophages in vitro confirmed that amastigotes, in contrast to promastigotes, induced IL-12 p40 mRNA. Reexamination of the cytokine mRNA at 4 d revealed expression of IL-13 in all strains analyzed, suggesting that IL-2 and IL-13 may mediate the IL-12-independent production of IFN-gamma during the first days after infection. Leishmania have evolved to avoid inducing IL-12 from host macrophages during transmission from the insect vector, and cause a striking induction of mRNAs for IL-2, IL-4, IL-10, and IL-13 in

  15. Prophylactic immunization against experimental leishmaniasis. III. Protection against fatal Leishmania tropica infection induced by irradiated promastigotes involves Lyt-1/sup +/2/sup -/ T cells that do not mediate cutaneous DTH

    SciTech Connect

    Liew, F.Y.; Howard, J.G.; Hale, C.

    1984-01-01

    Protective immunity against fatal L. tropica infection in genetically vulnerable BALB/c mice can be induced by prophylactic immunization with irradiated promastigotes even when heat-killed. Such immunity is adoptively transferable transiently into intact or durably into sub-lethally irradiated (200 or 550 rad) syngeneic recipients by splenic T but not B cells. The effector T cells are of the Lyt-1/sup +/2/sup -/ phenotype, devoid of demonstrable cytotoxic activity. The immune splenic T cell population expresses specific helper activity for antibody synthesis. A causal role for helper T cells in this capacity, however, seems unlikely, because it was shown that antibody does not determine the protective immunity against L. tropica. The immunized donors show no detectable cutaneous DTH or its early memory recall in response to live or killed promastigotes or a soluble L. tropica antigen preparation. Spleen, lymph node, and peritoneal exudate cells from protectively immunized donors similarly fail to transfer DTH locally or systemically. These cells also lack demonstrable suppressive activity against the expression or induction of DTH to L. tropica. Thus, protection against L. tropica induced by prophylactic i.v. immunization with irradiated promastigotes appears to be conferred by Lyt-1/sup +/2/sup -/ T cells that are distinguishable from T cells mediating either both DTH and T help, or cytotoxicity.

  16. Phototoxic effects of silicon bis (dimetilaminoetanoxi)-phthalocyanine (SiPc) on the viability of Leishmania major and Leishmania braziliensis promastigotes

    NASA Astrophysics Data System (ADS)

    Guerra Pinto, Juliana; Ferreira-Strixino, Juliana; Mittmann, Josane

    2016-06-01

    American cutaneous leishmaniasis (ACL) is an infectious disease caused by protozoans of the genus Leishmania. The treatment may consist of pentavalent antimonials or pentamidine and amphotericin. However, these treatments are extremely aggressive. Photodynamic antimicrobial chemotherapy (PACT) involves the same mechanism of photodynamic therapy which associates a photosensitizer with oxygen and a light source generating a photochemical reaction leading to cell death. The aim of this study was to verify the potential use of silicon bis (dimetilaminoetanoxi)-phthalocyanine (SiPc) compound in photodynamic treatment through evaluation of its phototoxic effect in promastigotes of the genus Leishmania braziliensis and Leishmania major. Treatment with SiPc was able to drastically affect the viability of the parasites as well as affect their growth and morphology, after PACT treatment. The data shown in this study allows us to conclude that SiPc is a promising photosensitizer (PS) since it does not affect parasite growth and viability in the dark. After PACT with this phthalocyanine, over 99% of parasites were killed with the higher concentration and a light dose used. These results suggest that SiPc can be used in future to treat CL, however, further studies are necessary to determine whether the PS are toxic to mononuclear phagocytic cells and epithelial cells which will also be affected by therapy when applied topically.

  17. The Leishmania donovani UMP Synthase Is Essential for Promastigote Viability and Has an Unusual Tetrameric Structure That Exhibits Substrate-controlled Oligomerization

    SciTech Connect

    French, Jarrod B.; Yates, Phillip A.; Soysa, D.Radika; Boitz, Jan M.; Carter, Nicola S.; Chang, Bailey; Ullman, Buddy; Ealick, Steven E.

    2011-08-09

    The final two steps of de novo uridine 5'-monophosphate (UMP) biosynthesis are catalyzed by orotate phosphoribosyltransferase (OPRT) and orotidine 5'-monophosphate decarboxylase (OMPDC). In most prokaryotes and simple eukaryotes these two enzymes are encoded by separate genes, whereas in mammals they are expressed as a bifunctional gene product called UMP synthase (UMPS), with OPRT at the N terminus and OMPDC at the C terminus. Leishmania and some closely related organisms also express a bifunctional enzyme for these two steps, but the domain order is reversed relative to mammalian UMPS. In this work we demonstrate that L. donovani UMPS (LdUMPS) is an essential enzyme in promastigotes and that it is sequestered in the parasite glycosome. We also present the crystal structure of the LdUMPS in complex with its product, UMP. This structure reveals an unusual tetramer with two head to head and two tail to tail interactions, resulting in two dimeric OMPDC and two dimeric OPRT functional domains. In addition, we provide structural and biochemical evidence that oligomerization of LdUMPS is controlled by product binding at the OPRT active site. We propose a model for the assembly of the catalytically relevant LdUMPS tetramer and discuss the implications for the structure of mammalian UMPS.

  18. LB broth-lyophilized Rabbit serum (LLR) as a new and suitable culture medium for cultivation of promastigotes of Leishmania major.

    PubMed

    Nasiri, Vahid; Dalimi, Abdolhossein; Ghaffarifar, Fatemeh

    2017-03-01

    Fetal calf serum is the major part and the most expensive ingredient of the Leishmania culture media. Here, the efficacy of the LB broth-lyophilized Rabbit serum medium (LLR) was evaluated in cultivation of Leishmaniamajor. Conventional Luria-Bertani (LB) broth medium was prepared and autoclaved for 15 min at 121 °C and then lyophilized Rabbit serum was added at the 1, 2.5, 5 and 10 % final concentrations. The efficacy of medium was evaluated by assessing the growth ability and replication pattern of the promastigotes of L. major. According to our finding, the LLR medium with 5-10 % lyophilized Rabbit serum supported the growth of the parasites and can be used for cultivation of Leishmanian parasites with acceptable In vivo infectivity for research purpose. The ability of the parasites to survive and proliferating in the presence of lyophilized Rabbit serum indicating that this serum is a good nutritional source. This study opens a new way to make low-cost medium that could be used in cultivation of Leishmanian parasites.

  19. Leishmania panamensis: comparative inhibition of nuclear DNA topoisomerase II enzymes from promastigotes and human macrophages reveals anti-parasite selectivity of fluoroquinolones, flavonoids and pentamidine.

    PubMed

    Cortázar, Tania M; Coombs, Graham H; Walker, John

    2007-08-01

    Certain model inhibitors exerted selective action against the catalytic activity of nuclear DNA topoisomerase II (TOPII) of Leishmania panamensis promastigotes. The second-generation fluoroquinolones enoxacin and ciprofloxacin exhibited extraordinarily high anti-parasite selectivity displaying 582- and 40-fold greater potencies against L. panamensis TOPII as compared with the human macrophage enzyme. The flavonoids quercetin and ellagic acid showed inverse specificities, the former being 161-fold more potent against L. panamensis TOPII, and the latter 15.7-fold more active against macrophage TOPII. The protoberberine coralyne was a potent inhibitor of both Leishmania and macrophage TOPII. Bis-benzimidazoles and the diamidine diminazene aceturate exhibited uniformly high potencies against parasite and host TOPII, but a second diamidine pentamidine showed 17.6-fold greater specificity for Leishmania TOPII. The antimonial sodium stibogluconate was an ineffective inhibitor of parasite TOPII showing 4.3-fold greater potency against the macrophage enzyme. These findings suggest that the leishmanicidal activities of certain fluoroquinolones and pentamidine may be mediated partly through TOPII inhibition.

  20. IMP dehydrogenase deficiency in Leishmania donovani causes a restrictive growth phenotype in promastigotes but is not essential for infection in mice.

    PubMed

    Fulwiler, Audrey L; Boitz, Jan M; Gilroy, Caslin; Yates, Phillip A; Jardim, Armando; Ullman, Buddy

    2011-12-01

    Leishmania cannot synthesize purines de novo and therefore must scavenge purines from its host for survival and growth. Biochemical and genomic analyses have indicated that Leishmania species express three potential routes for the synthesis of guanylate nucleotides: (1) a two-step pathway that converts IMP to GMP; (2) a three-step pathway that starts with the deamination of guanine to xanthine, followed by phosphoribosylation to XMP and then conversion to GMP; or (3) direct guanine phosphoribosylation by HGPRT. To determine the role of the first of these pathways to guanylate nucleotide synthesis, an L. donovani line deficient in IMP dehydrogenase (IMPDH), the first step in the IMP to GMP pathway, was constructed by targeted gene replacement. The Δimpdh lesion triggered a highly restrictive growth phenotype in promastigotes in culture but did not impact parasitemias in mice. The dispensability of IMPDH in vivo is the first definitive demonstration that intracellular L. donovani amastigotes have access to a sufficient pool of guanine, xanthine, or guanylate precursors from the host. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. The use of a water-soluble formazan complex to quantitate the cell number and mitochondrial function of Leishmania major promastigotes.

    PubMed

    Berg, K; Zhai, L; Chen, M; Kharazmi, A; Owen, T C

    1994-01-01

    One of the methods to quantitate Leishmania major promastigotes (LmP) has been to utilize the formation of a formazan dye, which in turn is produced via conversion of an artificial substrate, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). The method has one major drawback in that the formazan complex precipitates inside the parasites and has to be extracted by denaturants before measurements can be performed. By using a new synthetic substrate, 3-(4,5-dimethylthiazol-2-yl)-5- (3-carboxymethoxyphenyl)-2-(4-sulfonyl)-2H-tetrazolium (MTS), the extraction procedure is eliminated as the formazan-like dye is released spontaneously into the medium, making it possible to perform several measurements on the same parasite culture without disturbing or killing the parasites. The measurements were shown to reflect the numbers of parasites as confirmed via comparative experiments using radioactive thymidine uptake and cell counting, respectively. The method is simple, fast, and highly reproducible and is suitable for drug screening, identification of drug-resistant isolates, and growth-kinetics studies. It is therefore contemplated that the MTS method will be a general and useful technique in this field of parasitology.

  2. The Leishmania donovani UMP Synthase Is Essential for Promastigote Viability and Has an Unusual Tetrameric Structure That Exhibits Substrate-controlled Oligomerization*

    PubMed Central

    French, Jarrod B.; Yates, Phillip A.; Soysa, D. Radika; Boitz, Jan M.; Carter, Nicola S.; Chang, Bailey; Ullman, Buddy; Ealick, Steven E.

    2011-01-01

    The final two steps of de novo uridine 5′-monophosphate (UMP) biosynthesis are catalyzed by orotate phosphoribosyltransferase (OPRT) and orotidine 5′-monophosphate decarboxylase (OMPDC). In most prokaryotes and simple eukaryotes these two enzymes are encoded by separate genes, whereas in mammals they are expressed as a bifunctional gene product called UMP synthase (UMPS), with OPRT at the N terminus and OMPDC at the C terminus. Leishmania and some closely related organisms also express a bifunctional enzyme for these two steps, but the domain order is reversed relative to mammalian UMPS. In this work we demonstrate that L. donovani UMPS (LdUMPS) is an essential enzyme in promastigotes and that it is sequestered in the parasite glycosome. We also present the crystal structure of the LdUMPS in complex with its product, UMP. This structure reveals an unusual tetramer with two head to head and two tail to tail interactions, resulting in two dimeric OMPDC and two dimeric OPRT functional domains. In addition, we provide structural and biochemical evidence that oligomerization of LdUMPS is controlled by product binding at the OPRT active site. We propose a model for the assembly of the catalytically relevant LdUMPS tetramer and discuss the implications for the structure of mammalian UMPS. PMID:21507942

  3. CvL, a lectin from the marine sponge Cliona varians: Isolation, characterization and its effects on pathogenic bacteria and Leishmania promastigotes.

    PubMed

    Moura, Raniere M; Queiroz, Alexandre F S; Fook, Jacy M S L L; Dias, Anny S F; Monteiro, Norberto K V; Ribeiro, Jannisson K C; Moura, Gioconda E D D; Macedo, Leonardo L P; Santos, Elizeu A; Sales, Maurício P

    2006-12-01

    CvL, a lectin from the marine sponge Cliona varians was purified by acetone fractionation followed by Sepharose CL 4B affinity chromatography. CvL agglutinated papainized treated human erythrocytes with preference for type A erythrocytes. The lectin was strongly inhibited by monosaccharide d-galactose and disaccharide sucrose. CvL is a tetrameric glycoprotein of 28 kDa subunits linked by disulphide bridges with a molecular mass of 106 kDa by SDS-PAGE and 114 kDa by Sephacryl S300 gel filtration. The lectin was Ca2+ dependent, stable up to 60 degrees C for 60 min, with optimum pH of 7.5. CvL displays a cytotoxic effect on gram positive bacteria, such as Bacillus subtilis and Staphylococcus aureus. However, CvL did not affect gram negative bacteria, such as Escherichia coli and Pseudomonas aeruginosa. Leishmania chagasi promastigotes were agglutinated by CvL up to 2(8) titer. These findings are indicative of the physiological defense roles of CvL and its possible use in the antibiosis of bacteria and protozoa pathogenic.

  4. GRIND2-based 3D-QSAR and prediction of activity spectra for symmetrical bis-pyridinium salts with promastigote antileishmanial activity.

    PubMed

    Diniz, Evelyn Mirella Lopes Pina; Tomich de Paula da Silva, Carlos Henrique; Gómez-Perez, Verónica; Federico, Leonardo Bruno; Campos Rosa, Joaquín María

    2017-08-01

    Leishmaniasis is a major group of neglected tropical diseases caused by the protozoan parasite Leishmania. About 12 million people are affected in 98 countries and 350 million people worldwide are at risk of infection. Current leishmaniasis treatments rely on a relatively small arsenal of drugs, including amphotericin B, pentamidine and others, which in general have some type of inconvenience. Recently, we have synthesized antileishmanial bis-pyridinium derivatives and symmetrical bis-pyridinium cyclophanes. These compounds are considered structural analogues of pentamidine, where the amidino moiety, protonated at physiological pH, is replaced by a positively charged nitrogen atom as a pyridinium ring. In this work, a statistically significant GRIND2-based 3D-QSAR model was built and biological activity predictions were in silico carried out allowing rationalization of the different activities recently obtained against Leishmania donovani (in L. donovani promastigotes) for a data set of 19 bis-pyridinium compounds. We will emphasize the most important structural requirements to improve the biological activity and probable interactions with the biological receptor as a guide for lead and prototype optimization. In addition, since no information about the actual biological target for this series of active compounds is provided, we have used Prediction of Activity Spectra for Biologically Active Substances to propose our compounds as potential nicotinic α6β3β4α5 receptor antagonists. This proposal is reinforced by the high structural similarity observed between our compounds and several anthelmintic drugs in current clinical use, which have the same drug action mechanism here predicted. Such new findings would be confirmed with further and additional experimental assays.

  5. Nivel de Actividad Física, Autoeficacia, Beneficios y Barreras Percibidas en Mujeres Mayores Mexicanas Independientes (Physical Activity Level, Exercise Self-Efficacy, Benefits and Perceived Barriers of Independent Mexican Older Women).

    PubMed

    Enríquez-Reyna, María Cristina; Cruz-Castruita, Rosa María; Zamarripa, Jorge; Ceballos-Gurrola, Oswaldo; Guevara-Valtier, Milton Carlos

    2016-03-01

    This descriptive comparative study examined differences in personal characteristics, exercise self-efficacy, benefits and barriers of independent elderly women to perform physical activity (PA) according with the PA level. Two hundred three women older than 60 years of age, from a community located in Nuevo Leon, Mexico participated in the study. Data was collected using: a) A personal data questionnaire, b) Exercise Self-Efficacy Scale, c) Exercise Benefits/ Barriers Scale and d) Physical Activity Scale for the Elderly were completed. Age was similar in participants with low and acceptable PA level. Participants with lower levels of PA reported consuming more medications, fewer years of education and lower values of exercise self-efficacy, benefits and barriers. In this sample, exercise self-efficacy and benefits were positively associated with the PA level.

  6. Antigenicity, Immunogenicity and Protective Efficacy of Three Proteins Expressed in the Promastigote and Amastigote Stages of Leishmania infantum against Visceral Leishmaniasis

    PubMed Central

    Martins, Vivian Tamietti; Chávez-Fumagalli, Miguel Angel; Lage, Daniela Pagliara; Duarte, Mariana Costa; Garde, Esther; Costa, Lourena Emanuele; da Silva, Viviane Gomes; Oliveira, Jamil Silvano; de Magalhães-Soares, Danielle Ferreira; Teixeira, Santuza Maria Ribeiro; Fernandes, Ana Paula; Soto, Manuel; Tavares, Carlos Alberto Pereira; Coelho, Eduardo Antonio Ferraz

    2015-01-01

    In the present study, two Leishmania infantum hypothetical proteins present in the amastigote stage, LiHyp1 and LiHyp6, were combined with a promastigote protein, IgE-dependent histamine-releasing factor (HRF); to compose a polyproteins vaccine to be evaluated against L. infantum infection. Also, the antigenicity of the three proteins was analyzed, and their use for the serodiagnosis of canine visceral leishmaniasis (CVL) was evaluated. The LiHyp1, LiHyp6, and HRF DNA coding sequences were cloned in prokaryotic expression vectors and the recombinant proteins were purified. When employed in ELISA assays, all proteins were recognized by sera from visceral leishmaniasis (VL) dogs, and presented no cross-reactivity with either sera from dogs vaccinated with a Brazilian commercial vaccine, or sera of Trypanosoma cruzi-infected or Ehrlichia canis-infected animals. In addition, the antigens were not recognized by antibodies from non-infected animals living in endemic or non-endemic areas for leishmaniasis. The immunogenicity and protective efficacy of the three proteins administered in the presence of saponin, individually or in combination (composing a polyproteins vaccine), were evaluated in a VL murine model: BALB/c mice infected with L. infantum. Spleen cells from mice inoculated with the individual proteins or with the polyproteins vaccine plus saponin showed a protein-specific production of IFN-γ, IL-12, and GM-CSF after an in vitro stimulation, which was maintained after infection. These animals presented significant reductions in the parasite burden in different evaluated organs, when compared to mice inoculated with saline or saponin. The decrease in parasite burden was associated with an IL-12-dependent production of IFN-γ against parasite total extracts (produced mainly by CD4+ T cells), correlated to the induction of parasite proteins-driven NO production. Mice inoculated with the recombinant protein-based vaccines showed also high levels of parasite

  7. Antigenicity, Immunogenicity and Protective Efficacy of Three Proteins Expressed in the Promastigote and Amastigote Stages of Leishmania infantum against Visceral Leishmaniasis.

    PubMed

    Martins, Vivian Tamietti; Chávez-Fumagalli, Miguel Angel; Lage, Daniela Pagliara; Duarte, Mariana Costa; Garde, Esther; Costa, Lourena Emanuele; da Silva, Viviane Grazielle; Silva, Viviane Gomes da; Oliveira, Jamil Silvano; Magalhães-Soares, Danielle Ferreira de; Teixeira, Santuza Maria Ribeiro; Fernandes, Ana Paula; Soto, Manuel; Tavares, Carlos Alberto Pereira; Coelho, Eduardo Antonio Ferraz

    2015-01-01

    In the present study, two Leishmania infantum hypothetical proteins present in the amastigote stage, LiHyp1 and LiHyp6, were combined with a promastigote protein, IgE-dependent histamine-releasing factor (HRF); to compose a polyproteins vaccine to be evaluated against L. infantum infection. Also, the antigenicity of the three proteins was analyzed, and their use for the serodiagnosis of canine visceral leishmaniasis (CVL) was evaluated. The LiHyp1, LiHyp6, and HRF DNA coding sequences were cloned in prokaryotic expression vectors and the recombinant proteins were purified. When employed in ELISA assays, all proteins were recognized by sera from visceral leishmaniasis (VL) dogs, and presented no cross-reactivity with either sera from dogs vaccinated with a Brazilian commercial vaccine, or sera of Trypanosoma cruzi-infected or Ehrlichia canis-infected animals. In addition, the antigens were not recognized by antibodies from non-infected animals living in endemic or non-endemic areas for leishmaniasis. The immunogenicity and protective efficacy of the three proteins administered in the presence of saponin, individually or in combination (composing a polyproteins vaccine), were evaluated in a VL murine model: BALB/c mice infected with L. infantum. Spleen cells from mice inoculated with the individual proteins or with the polyproteins vaccine plus saponin showed a protein-specific production of IFN-γ, IL-12, and GM-CSF after an in vitro stimulation, which was maintained after infection. These animals presented significant reductions in the parasite burden in different evaluated organs, when compared to mice inoculated with saline or saponin. The decrease in parasite burden was associated with an IL-12-dependent production of IFN-γ against parasite total extracts (produced mainly by CD4+ T cells), correlated to the induction of parasite proteins-driven NO production. Mice inoculated with the recombinant protein-based vaccines showed also high levels of parasite

  8. Sterols with antileishmanial activity isolated from the roots of Pentalinon andrieuxii

    PubMed Central

    Pan, Li; Lezama-Davila, Claudio M.; Isaac-Marquez, Angelica P.; Calomeni, Edward P.; Fuchs, James R.; Satoskar, Abhay R.; Kinghorn, A. Douglas

    2012-01-01

    A new cholesterol derivative, pentalinonsterol (cholest-4,20,24-trien-3-one, 1), and a new polyoxygenated pregnane sterol glycoside, pentalinonside (2), together with 18 known compounds, including 14 sterols (3–16), three coumarins (17–19), and a triterpene (20), were isolated from a n-hexane partition of a methanol extract of the roots of the Mexican medicinal plant Pentalinon andrieuxii. Structure elucidation of compounds 1 and 2 was accomplished by spectroscopic data interpretation. All isolates were evaluated in vitro for their antileishmanial activity. Among these compounds, 6,7-dihydroneridienone (15) was found to be the most potent principle against promastigotes of Leishmania mexicana (L. mexicana). The cholesterol analogue, pentalinonsterol (1), together with two known sterols, 24-methylcholest-4,24(28)-dien-3-one (3) and neridienone (16), also exhibited significant leishmanicidal activity in this same bioassay. Compounds 1, 3, 15, 16, cholest-4-en-3-one (4), and cholest-5,20,24-trien-3β-ol (7), showed strong antileishmanial activity against amastigotes of L. mexicana, and 4 was found to be the most potent agent with an IC50 value of 0.03 μM. All the isolates were also evaluated for their cytotoxicity in non-infected bone marrow-derived macrophages, but none of these compounds was found active towards this cell line. The intracellular parasites treated with compounds 1, 3, 4, 15, and 16 were further studied by electron microscopy; morphological abnormalities and destruction of the amastigotes were observed, as a result of treatment with these compounds. PMID:22840389

  9. Sterols with antileishmanial activity isolated from the roots of Pentalinon andrieuxii.

    PubMed

    Pan, Li; Lezama-Davila, Claudio M; Isaac-Marquez, Angelica P; Calomeni, Edward P; Fuchs, James R; Satoskar, Abhay R; Kinghorn, A Douglas

    2012-10-01

    A new cholesterol derivative, pentalinonsterol (cholest-4,20,24-trien-3-one, 1), and a new polyoxygenated pregnane sterol glycoside, pentalinonside (2), together with 18 known compounds, including 14 sterols (3-16), three coumarins (17-19), and a triterpene (20), were isolated from a n-hexane partition of a methanol extract of the roots of the Mexican medicinal plant Pentalinon andrieuxii. Structure elucidation of compounds 1 and 2 was accomplished by spectroscopic data interpretation. All isolates were evaluated in vitro for their antileishmanial activity. Among these compounds, 6,7-dihydroneridienone (15) was found to be the most potent principle against promastigotes of Leishmania mexicana (L. mexicana). The cholesterol analogue, pentalinonsterol (1), together with two known sterols, 24-methylcholest-4,24(28)-dien-3-one (3) and neridienone (16), also exhibited significant leishmanicidal activity in this same bioassay. Compounds 1, 3, 15, 16, cholest-4-en-3-one (4), and cholest-5,20,24-trien-3β-ol (7), showed strong antileishmanial activity against amastigotes of L. mexicana, and 4 was found to be the most potent agent with an IC(50) value of 0.03μM. All the isolates were also evaluated for their cytotoxicity in non-infected bone marrow-derived macrophages, but none of these compounds was found active towards this cell line. The intracellular parasites treated with compounds 1, 3, 4, 15, and 16 were further studied by electron microscopy; morphological abnormalities and destruction of the amastigotes were observed, as a result of treatment with these compounds. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Fungus-Elicited Metabolites from Plants as an Enriched Source for New Leishmanicidal Agents: Antifungal Phenyl-Phenalenone Phytoalexins from the Banana Plant (Musa acuminata) Target Mitochondria of Leishmania donovani Promastigotes

    PubMed Central

    Luque-Ortega, Juan Román; Martínez, Silvia; Saugar, José María; Izquierdo, Laura R.; Abad, Teresa; Luis, Javier G.; Piñero, José; Valladares, Basilio; Rivas, Luis

    2004-01-01

    Two antifungal phenyl-phenalenone phytoalexins isolated from the banana plant (Musa acuminata) elicited with the fungus Fusarium oxysporum, together with a methoxy derivative of one of them and two epoxide precursors of their chemical synthesis, were tested for leishmanicidal activity on Leishmania donovani promastigotes and L. infantum amastigotes. Drugs inhibited proliferation of both forms of the parasite with a 50% lethal concentration range between 10.3 and 68.7 μg/ml. Their lethal mechanism was found linked to the respiratory chain by a systematic approach, including electron microscopy, measurement of the oxygen consumption rate on digitonin-permeabilized promastigotes, and enzymatic assays on a mitochondrial enriched fraction. Whereas the whole set of compounds inhibited the activity of fumarate reductase in the mitochondrial fraction (50% effective concentration [EC50] between 33.3 and 78.8 μg/ml) and on purified enzyme (EC50 = 53.3 to 115 μg/ml), inhibition for succinate dehydrogenase was only observed for the two phytoalexins with the highest leishmanicidal activity: anigorufone and its natural analogue 2-methoxy-9-phenyl-phenalen-1-one (EC50 = 33.5 and 59.6 μg/ml, respectively). These results provided a new structural motif, phenyl-phenalenone, as a new lead for leishmanicidal activity, and support the use of plant extracts enriched in antifungal phytoalexins, synthesized under fungal challenge, as a more rational and effective strategy to screen for new plant leishmanicidal drugs. PMID:15105102

  11. Activity of Hydroxyurea against Leishmania mexicana▿

    PubMed Central

    Martinez-Rojano, Hugo; Mancilla-Ramirez, Javier; Quiñonez-Diaz, Laura; Galindo-Sevilla, Norma

    2008-01-01

    Leishmania mexicana is a protozoan parasite that causes a disease in humans with frequent relapses after treatment. It is also highly resistant to the currently available drugs. For this reason, there is an urgent need for more effective antileishmanial drugs. Hydroxyurea, an anticancer drug, is toxic to replicating eukaryotic cells and has been proven to be effective in arresting the Leishmania major cell cycle. In this study, hydroxyurea was tested in an in vitro model of intracellular Leishmania infection in macrophages. The parasite density in infected macrophages was measured by microscopy after incubation for various times and treatment with hydroxyurea at different concentrations. Viable parasites that could be transformed into promastigotes by shifting the temperature to 26°C were counted every other day after the replacement of hydroxyurea with fresh medium. Meglumine antimoniate, the standard drug treatment for Leishmania mexicana, was used as a reference drug under the same experimental conditions. Hydroxyurea completely eliminated Leishmania parasites when it was used at a dosage of 10 or 100 μg/ml. Differences in the length of treatment needed to achieve elimination were as follows: the 10-μg/ml doses required 9 days, while 3 days was sufficient when 100 μg/ml was used. Hydroxyurea had a 50% effective dose of 0.015 μg/ml in vitro, which was observed on day 6 after exposure. Hydroxyurea is highly effective in killing intracellular amastigotes in vitro. PMID:18694950

  12. The Genus Ixodes (Acari: Ixodidae) in Mexico: Adult Identification Keys, Diagnoses, Hosts, and Distribution (El genero Ixodes (Acari: Ixodidae) en Mexico: claves de identificacion para adultos, diagnosis, huespedes y distribucion)

    DTIC Science & Technology

    2010-01-01

    Revista Mexicana de Biodiversidad 81: 289- 298, 2010 Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection...internal spur of coxa I overlapping anterior margin of coxa II .................I. tovari Revista Mexicana de Biodiversidad 80: 289- 298, 2010...Revista Mexicana de Biodiversidad 80: 289- 298, 2010 293 I with internal and external spurs about equal in length; coxae II-IV with small

  13. The Balloon Effect and Mexican Homeland Security: What it Means to be the Weakest Link in the Americas’ Security Chain

    DTIC Science & Technology

    2011-12-01

    as a threat to Mexican society (Presidencia de la Republica Mexicana, 2007b), but also in the United States, where Department of Homeland Secretary...fight among them as they compete for places to perform their activities (Presidencia de la Republica Mexicana, 2011). These fights are causing...Calderón’s administration developed high-impact operations against transnational, organized crime (Presidencia de 6 la Republica Mexicana, 2007

  14. Survival in an extreme habitat: the roles of behaviour and energy limitation

    NASA Astrophysics Data System (ADS)

    Plath, Martin; Tobler, Michael; Riesch, Rüdiger; García de León, Francisco J.; Giere, Olav; Schlupp, Ingo

    2007-12-01

    Extreme habitats challenge animals with highly adverse conditions, like extreme temperatures or toxic substances. In this paper, we report of a fish ( Poecilia mexicana) inhabiting a limestone cave in Mexico. Several springs inside the cave are rich in toxic H2S. We demonstrate that a behavioural adaptation, aquatic surface respiration (ASR), allows for the survival of P. mexicana in this extreme, sulphidic habitat. Without the possibility to perform ASR, the survival rate of P. mexicana was low even at comparatively low H2S concentrations. Furthermore, we show that food limitation affects the survival of P. mexicana pointing to energetically costly physiological adaptations to detoxify H2S.

  15. Antimony quantification in Leishmania by electrothermal atomic absorption spectroscopy.

    PubMed

    Roberts, W L; Rainey, P M

    1993-05-15

    Tri- and pentavalent antimony were quantified in Leishmania mexicana pifanoi amastigotes and promastigotes by atomic absorption spectroscopy with electrothermal atomization. Leishmania grown in axenic culture were treated with either potassium antimony tartrate [Sb(III)] or sodium stibogluconate [Sb(V)]. The parasites were collected, digested with nitric acid, and subjected to atomic absorption spectroscopy. The method was linear from 0 to 7 ng of antimony. The interassay coefficients of variation were 9.6 and 5.7% (N = 5) for 0.52 and 3.7-ng samples of leishmanial antimony, respectively. The limit of detection was 95 pg of antimony. The assay was used to characterize Sb(III) and Sb(V) influx and efflux kinetics. Influx rates were determined at antimony concentrations that produced a 50% inhibition of growth (IC50). The influx rates of Sb(V) into amastigotes and promastigotes were 4.8 and 12 pg/million cells/h, respectively, at 200 micrograms antimony/ml. The influx rate of Sb(III) into amastigotes was 41 pg/million cells/h at 20 micrograms antimony/ml. Influx of Sb(III) into promastigotes at 1 microgram antimony/ml was rapid and reached a plateau of 175 pg/million cells in 2 h. Efflux of Sb(III) and Sb(V) from amastigotes and promastigotes exhibited biphasic kinetics. The initial (alpha) half-life of Sb(V) efflux was less than 4 min and that of Sb(III) was 1-2 h. The apparent terminal (beta) half-lives ranged from 7 to 14 h.

  16. NAFTA: A Partial Solution Not a Savior to Mexico’s Economic Woes

    DTIC Science & Technology

    2011-10-28

    Mexico.” Economia Mexicana. 15 January 2004. http://www.economiamexicana.cide.edu/num_anteriores/XIV-2/LILIANA_MEZA.pdf (accessed: 28 October 2011...Mexico.” Economia Mexicana. 15 January 2004. http://www.economiamexicana.cide.edu/num_anteriores/XIV-2/LILIANA_MEZA.pdf (accessed: 28 October 2011

  17. Cutaneous leishmaniasis in Texas: report of a case and review of the literature.

    PubMed

    Furner, B B

    1990-08-01

    Cutaneous leishmaniasis is endemic in south central Texas. There have been at least eight cases, four of which have been reported since 1980. An additional case of cutaneous leishmaniasis is reported in a 56-year-old woman from Sandia, Texas. The diagnosis was confirmed by culture of Leishmania mexicana var. mexicana.

  18. The microcaddisfly genus Ithytrichia Eaton (Trichoptera: Hydroptilidae) in North America

    USGS Publications Warehouse

    Moulton, S.R.; Harris, S.C.; Slusark, J.P.

    1999-01-01

    The distribution and taxonomy of the microcaddisfly genus Ithytrichia Eaton in North America is reviewed. Males and females of I. clavata Morton, I. mazon Ross, and I. mexicana Harris and Contreras-Ramos are illustrated, and a key is provided for their separation. Females of I. mazon and I. mexicana are described for the first time; the female of I. clavata is redescribed.

  19. Anti-fixed Leishmania chagasi promastigotes IgG antibodies detected by flow cytometry (FC-AFPA-IgG) as a tool for serodiagnosis and for post-therapeutic cure assessment in American visceral leishmaniasis.

    PubMed

    Garcia, Lúcia Maria; Coelho-Dos-Reis, Jordana Grazziela Alves; Peruhype-Magalhães, Vanessa; Teixeira-Carvalho, Andréa; Rocha, Roberta Dias Rodrigues; Araújo, Márcio Sobreira Silva; Gomes, Izabelle Teixeira; Carvalho, Sílvio Fernando Guimarães; Dietze, Reynaldo; Lemos, Elenice Moreira; Andrade, Mariléia Chaves; Martins-Filho, Olindo Assis

    2009-10-31

    Visceral leishmaniasis (VL) is a systemic infection, caused by an intracellular protozoan parasite belonging to the Leishmania donovani complex. The diagnosis of VL is complex because most clinical features are shared with other commonly occurring febrile hepatosplenic diseases that can be endemic along with VL. A number of serological devices are available but still require improvement mainly due to residual post-therapeutic serology and the cross-reactivity with other Trypanosomatidae protozooses. This study intended to describe and evaluate the performance of an indirect immunofluorescence assay referred as flow cytometry anti-fixed Leishmania chagasi promastigote IgG antibodies (FC-AFPA-IgG) for serodiagnosis of VL and assessment of post-therapeutic cure. The sera reactivity is reported as the percentage of positive fluorescent parasite (PPFP) along the titration curve. The analysis of sera titration curve indicated the sera dilution 1/32,000 and the PPFP=25% as the cut-off to segregate positive and negative results. Using these parameters, the FC-AFPA-IgG displayed outstanding sensitivity and specificity for diagnosis and post-therapeutic cure assessment purposes. The inter-test reproducibility of FC-AFPA-IgG was also verified, considering two independent Analysts and validated the results obtained by FC-AFPA-IgG. Moreover, the comparison between FC-AFPA-IgG and the conventional serologic test (ELISA) showed that besides the statistically analogous results with strong positive correlation the FC-AFPA-IgG displayed higher performance indexes. Further analysis demonstrated that while cross-reactivity was observed in 8% of samples tested by ELISA, no cross-reactivity was detected by FC-AFPA-IgG. Together, the findings presented in this study showed the potential of FC-AFPA-IgG in both diagnosis and post-therapeutic cure assessment of VL.

  20. Th1-stimulatory polyproteins of soluble Leishmania donovani promastigotes ranging from 89.9 to 97.1 kDa offers long-lasting protection against experimental visceral leishmaniasis.

    PubMed

    Kumari, Shraddha; Samant, Mukesh; Misra, Pragya; Khare, Prashant; Sisodia, Brijesh; Shasany, Ajit K; Dube, Anuradha

    2008-10-23

    Our earlier studies identified a fraction (F2) of Leishmania donovani soluble promastigote antigen belonging to 97.4-68 kDa for its ability to stimulate Th1-type cellular responses in cured visceral leishmaniasis (VL) patients as well as in cured hamsters. A further fractionation of F2-fraction into seven subfractions (F2.1-F2.7) and re-assessment for their immunostimulatory responses revealed that out of these, only four (F2.4-F2.7) belonging to 89.9-97.1 kDa, stimulated remarkable Th1-type cellular responses either individually or in a pooled form (P4-7). In this study these potential subfractions were further assessed for their prophylactic potential in combination with BCG against L. donovani challenge in hamsters. Optimum parasite inhibition ( approximately 99%) was obtained in hamsters vaccinated with pooled subfractions and they survived for 1 year. The protection was further supported by remarkable lymphoproliferative, IFN-gamma and IL-12 responses along with profound delayed type hypersensitivity and increased levels of Leishmania-specific IgG2 antibody as observed on days 45, 90 and 120 post-challenge suggesting that a successful subunit vaccine against VL may require multiple Th1-immunostimulatory proteins. MALDI-TOF-MS/MS analysis of these subfractions further revealed that of the 19 identified immunostimulatory proteins, Elongation factor-2, p45, Heat shock protein-70/83, Aldolase, Enolase, Triosephosphate isomerase, Disulfideisomerase and Calreticulin were the major ones in these subfractions.

  1. Macromolecular biosynthetic parameters and metabolic profile in different life stages of Leishmania braziliensis: Amastigotes as a functionally less active stage.

    PubMed

    Jara, Marlene; Berg, Maya; Caljon, Guy; de Muylder, Geraldine; Cuypers, Bart; Castillo, Denis; Maes, Ilse; Orozco, María Del Carmen; Vanaerschot, Manu; Dujardin, Jean-Claude; Arevalo, Jorge

    2017-01-01

    It was recently hypothesized that Leishmania amastigotes could constitute a semi-quiescent stage characterized by low replication and reduced metabolic activity. This concept developed with Leishmania (Leishmania) mexicana and Leishmania (Leishmania) major models might explain numerous clinical and sub-clinical features of Leishmania (Viannia) braziliensis infections, like reactivation of the disease, non-response to chemotherapy or asymptomatic infections. We compared here in vitro the proliferative capability of L. (V.) braziliensis amastigotes and promastigotes, assessed the expression of key molecular parameters and performed metabolomic analysis. We found that contrary to the highly proliferative promastigotes, amastigotes (axenic and intracellular) do not show evidence of extensive proliferation. In parallel, amastigotes showed a significant decrease of (i) the kDNA mini-circle abundance, (ii) the intracellular ATP level, (iii) the ribosomal components: rRNA subunits 18S and 28S α and ribosomal proteins RPS15 and RPL19, (iv) total RNA and protein levels. An untargeted metabolomic study identified clear differences between the different life stages: in comparison to logarithmic promastigotes, axenic amastigotes showed (a) a strong decrease of 14 essential and non-essential amino acids and eight metabolites involved in polyamine synthesis, (b) extensive changes in the phospholipids composition and (c) increased levels of several endogenous and exogenous sterols. Altogether, our results show that L. (V.) braziliensis amastigotes can show a phenotype with negligible rate of proliferation, a lower capacity of biosynthesis, a reduced bio-energetic level and a strongly altered metabolism. Our results pave the way for further exploration of quiescence among amastigotes of this species.

  2. In vitro antitrypanosomal and antileishmanial activity of plants used in Benin in traditional medicine and bio-guided fractionation of the most active extract.

    PubMed

    Bero, Joanne; Hannaert, Véronique; Chataigné, Gabrielle; Hérent, Marie-France; Quetin-Leclercq, Joëlle

    2011-09-02

    The aim of the study was to evaluate the in vitro antitrypanosomal and antileishmanial activity of crude extracts of 10 plant species traditionally used in Benin to treat parasitic infections. For each species, dichloromethane, methanol and aqueous extracts were tested. Their antitrypanosomal and antileishmanial activities were evaluated in vitro on Trypanosoma brucei brucei (strain 427) (Tbb) and on promastigotes of Leishmania mexicana mexicana (MHOM/BZ/84/BEL46) (Lmm). The best growth inhibition was observed with the dichloromethane extracts of aerial parts of Acanthospermum hispidum DC. (Asteraceae) (IC(50)=14.5 μg/ml on Tbb and 11.1 μg/ml on Lmm), twigs of Keetia leucantha (K. Krause) Bridson (syn. Plectronia leucantha Krause) (IC(50)=5.8 μg/ml on Tbb), aerial parts of Byrsocarpus coccineus Schumach. & Thonn (syn. Rourea coccinea (Schumach. & Thonn.) Hook.f.) (IC(50)=14.7 μg/ml on Tbb) and aerial parts of Carpolobia lutea G.Don. (IC(50)=18.3 μg/ml on Tbb). All these extracts had a low cytotoxicity. It is not the case for the methanolic and water extracts of roots of Anchomanes difformis (Blume) Engl. (IC(50)=14.7 and 13.8 μg/ml on Tbb) which were toxic at the same concentration range on WI38, human cells. A bio-guided fractionation of the most active extract of Keetia leucantha allowed to identify oleanolic acid and ursolic acid as responsible for the observed activities. Our study gives some justification for antiparasitic activity of some investigated plants. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  3. ITS1 PCR-RFLP Diagnosis and Characterization of Leishmania in Clinical Samples and Strains from Cases of Human Cutaneous Leishmaniasis in States of the Mexican Southeast

    PubMed Central

    Monroy-Ostria, Amalia; Nasereddin, Abedelmajeed; Monteon, Victor M.; Guzmán-Bracho, Carmen; Jaffe, Charles L.

    2014-01-01

    American cutaneous leishmaniasis includes a spectrum of clinical forms localized cutaneous, diffuse cutaneous, and mucocutaneous leishmaniasis which can be caused by different strains of Leishmania belonging to the L. mexicana or L. braziliensis complexes which may coexist in the same endemic area. We evaluated the PCR-RFLP assay of the ITS1 genes for direct identification of Leishmania species in 163 clinical samples and 21 Mexican isolates of Leishmania. In relation to the Mexican isolates of Leishmania 52% displayed a pattern similar to the L. (L.) mexicana, 5% showed a mixed pattern compatible with L. (L.) mexicana and L. (V.) braziliensis, eight with L. (L.) amazonensis and L. (L.) mexicana, and one to L. (V.) braziliensis. Most of the clinical samples, 109/116 (94%), gave a pattern similar to that of the L. mexicana, two clinical samples gave similar patterns to that of Leishmania braziliensis, and 5 samples gave patterns that suggest a coinfection of L. (L.) mexicana and L. (V.) braziliensis or L. (L.) mexicana and L. (L.) amazonensis. The ITS1 PCR-RFLP assay is a multipurpose tool for diagnosis of Leishmania from clinical samples and enables determination of the infecting species of New World Leishmania in the field in relatively short time and low cost. PMID:25104958

  4. Complement binding to Leishmania donovani promastigotes (LD)

    SciTech Connect

    Puentes, S.M.; Bates, P.A.; Dwyer, D.M.; Joiner, K.A.

    1986-03-01

    To study the binding and processing of C3 on LD, parasites in various phases of growth were incubated in human serum deficient in complement component 8 containing /sup 125/I-C3. Uptake of /sup 125/I-C3 is rapid, peaking at 1.7-2.1 x 10/sup 6/ C3 molecules bound per parasite at 15 minutes for all growth phases, and decreases thereafter with continued incubation. One half of total C3 bound is spontaneously released by 90 minutes of incubation with all LD phases and occurs at a similar rate for LD washed free of serum and incubated at 37/sup 0/ C in buffer. As assessed by SDS-PAGE autoradiography, C3 on the surface of LD is present as C3b (36 to 50%) and iC3b (50 to 65%), linked covalently via a bond resistant to hydroxylamine treatment, presumably an amide linkage. Immunoblot analysis of purified membranes from serum-incubated LD, using rabbit antibody to C3 and LD surface constituents, strongly suggests that a major C3 acceptor is the LD acid phosphatase (AP). These results, in conjunction with recent studies, suggest a previously unrecognized role of AP as a C3 acceptor and, thus, as a molecule potentially involved in parasite binding and uptake.

  5. Ecotin-Like ISP of L. major Promastigotes Fine-Tunes Macrophage Phagocytosis by Limiting the Pericellular Release of Bradykinin from Surface-Bound Kininogens: A Survival Strategy Based on the Silencing of Proinflammatory G-Protein Coupled Kinin B2 and B1 Receptors

    PubMed Central

    Svensjö, Erik; Vellasco, Lucas; Scharfstein, Julio

    2014-01-01

    Inhibitors of serine peptidases (ISPs) expressed by Leishmania major enhance intracellular parasitism in macrophages by targeting neutrophil elastase (NE), a serine protease that couples phagocytosis to the prooxidative TLR4/PKR pathway. Here we investigated the functional interplay between ISP-expressing L. major and the kallikrein-kinin system (KKS). Enzymatic assays showed that NE inhibitor or recombinant ISP-2 inhibited KKS activation in human plasma activated by dextran sulfate. Intravital microscopy in the hamster cheek pouch showed that topically applied L. major promastigotes (WT and Δisp2/3 mutants) potently induced plasma leakage through the activation of bradykinin B2 receptors (B2R). Next, using mAbs against kininogen domains, we showed that these BK-precursor proteins are sequestered by L. major promastigotes, being expressed at higher % in the Δisp2/3 mutant population. Strikingly, analysis of the role of kinin pathway in the phagocytic uptake of L. major revealed that antagonists of B2R or B1R reversed the upregulated uptake of Δisp2/3 mutants without inhibiting macrophage internalization of WT L. major. Collectively, our results suggest that L. major ISP-2 fine-tunes macrophage phagocytosis by inhibiting the pericellular release of proinflammatory kinins from surface bound kininogens. Ongoing studies should clarify whether L. major ISP-2 subverts TLR4/PKR-dependent prooxidative responses of macrophages by preventing activation of G-protein coupled B2R/B1R. PMID:25294952

  6. Caesalpina pulcherrima (L.) Sw.

    Treesearch

    Nadia Navarrete-Tindall

    2002-01-01

    Caesalpina pulcherrima, is native to the West Indies and Mexico (Croat 1978) and has naturalized in El Salvador and Panama. Two similar species are the Mexican bird of paradise C. mexicana, and bird of paradise bush C. gilliesi.

  7. Developmental time, longevity, and lifetime fertility of three introduced parasitoids of the mealybug Paracoccus marginatus (Hemiptera: Pseudoccidae)

    USDA-ARS?s Scientific Manuscript database

    Developmental time, longevity, and lifetime fertility of three previously introduced parasitoids (Acerophagus papayae Noyes and Schauff, Anagyrus loecki Noyes and Menezes, and Pseudleptomastix mexicana Noyes and Schauff) (Hymenoptera: Encyrtidae) of the mealybug Paracoccus marginatus Williams and Gr...

  8. Host instar susceptibility and selection and interspecific competition of three introduced parasitoids of the mealybug Paracoccus marginatus (Hemiptera: Pseudococccidae)

    USDA-ARS?s Scientific Manuscript database

    Acerophagus papayae, Anagyrus loecki, and Pseudleptomastix mexicana, three introduced parasitoids of Paracoccus marginatus were investigated for host stage susceptibility and sex ratio, host stage suitability, and interspecific competition. All three parasitoid species were able to develop and emer...

  9. Biology, host instar suitability and susceptibility, and interspecific competition of three introduced parasitoids of Paracoccus marginatus (Hemiptera: Pseudococcidae)

    USDA-ARS?s Scientific Manuscript database

    Biology, host stage suitability and susceptibility, and interspecific competition of three previously introduced parasitoids (Acerophagus papayae, Anagyrus loecki, and Pseudleptomastix mexicana) (Hymenoptera: Encyrtidae) of Paracoccus marginatus were studied in the laboratory. Compared to P. mexica...

  10. Relationships among the spruces (Picea, Pinaceae) of southwestern North America

    Treesearch

    F. Thomas Ledig; Paul D. Hodgskiss; Konstanin V. Krutovskii; David B. Neale; Teobaldo Eguiluz-Piedra

    2004-01-01

    Numerous populations from six spruce taxa, including four relict endemics, Picea chihuahuana (Chihuahua spruce), P. martinezii (Martínez spruce), P. mexicana (Mexican spruce), and P. breweriana (Brewer spruce), and two widespread species, P. engelmannii (Engelmann spruce) and...

  11. Study of cutaneous leishmaniasis in the State of Campeche (Yucatan Peninsula), Mexico, over a period of two years.

    PubMed

    Hernández-Rivera, Mirsha Pamela; Hernández-Montes, Omar; Chiñas-Pérez, Adelaido; Batiza-Avelar, Juan Miguel; Sánchez-Tejeda, Gustavo; Wong-Ramírez, Carlos; Monroy-Ostria, Amalia

    2015-01-01

    To study cutaneous leishmaniasis (CL), in the Calakmul municipality of the Campeche State, during two years. Individuals with skin lesions were evaluated. Aspirates taken from the lesions were cultured, PCR was performed to diagnose the Leishmania species. The culture detected 42% of the samples. PCR diagnosed CL in 76% of the samples; of those 38% were from children and 62% from adults. 89% of the patients were infected with L. mexicana; 14.4% with Mexican strains of L. mexicana; 7% with L. braziliensis; 3.6% with L. mexicana and L. braziliensis. The most affected villages with CL were Dos Lagunas Sur with 12.3%, La Mancolona with 6.5% and La Guadalupe with 2.2% of prevalence, respectively. After the treatment with Glucantime, 96% of the patients were healed. CL is an important public health concern in Calakmul, and the parasite causing it belongs to Leishmania mexicana and Leishmania braziliensis complexes.

  12. Interspecific and intraspecific variation in Picea engelmannii and its congeneric cohorts: biosystematics, genecology, and climate change

    Treesearch

    Gerald E. Rehfeldt

    2004-01-01

    A series of common garden studies of 336 populations representing Picea engelmannii, P. pungens, P. glauca, P. mexicana, and P. chihuahuana provided as many as 13 growth and morphologic characters pertinent to biosystematics and genecology. Canonical discriminant analyses...

  13. Organosilicon Compounds and Polymers and Silicon Ceramics

    DTIC Science & Technology

    1992-11-23

    X Congreso Nacional de la Academia Mexicana de Quimica Inorganica (Zacatecas, Mexico; invited speaker) Institute of Materials Science, University of...Central Research and Development Department, du Pont (Wilmington, DE) Alcoa Technical Center XIX Congreso Latinoamericano de Quimica (Buenos Aires

  14. Leluthia astigma (Ashmead) (Hymenoptera: Braconidae: Doryctinae) as a parasitoid of Agrilus planipennis Fairmaire (Coleoptera: Buprestidae: Agrilinae), with an assessment of host associations for nearctic species of Leluthia Cameron.

    Treesearch

    Robert R. Kula; Kathleen S. Knight; Joanne Rebbeck; Leah S. Bauer; David L. Cappaert; Kamal J.K. Gandhi

    2010-01-01

    Published host associations are assessed for Leluthia astigma (Ashmead), Leluthia floridensis Marsh, and Leluthia mexicana Cameron, the three known species of Leluthia Cameron in the Nearctic Region. Leluthia astigma is reported as a parasitoid of Agrilus planipennis...

  15. "Estudia para que no te pase lo que a mi": Narrativas Culturales Sobre el Valor de la Escuela en Familias Mexicanas ("Study So That What Happened to Me Doesn't Happen to You": Cultural Narratives about the Value of Schooling in Mexican Families).

    ERIC Educational Resources Information Center

    Ramos, Claudia Saucedo

    2003-01-01

    Narratives used by parents in Mexican working-class families to motivate their children to study are examined for the advice offered and parental attitudes about the importance of school. The integration of contemporary pressures about the value of schooling is investigated, as well as the ways in which the value of schooling is being…

  16. Estimación de la Relación Costo-Efectividad de las Vacunas Neumocócicas Conjugadas Prevenar-13 y Synflorix®, Utilizadas en Los Programas de Vacunación de Población Infantil Mexicana.

    PubMed

    Gómez, Jorge A; Villaseñor-Sierra, Alberto; Aguilar, Gerardo Martínez; Manjarrez, Roberto Carreño; Cervantes-Apolinar, María Y

    2016-12-01

    To estimate the cost effectiveness associated with the use of pneumococcal conjugated vaccines, Prevenar-13 and Synflorix®, in the Mexican pediatric population. The cost-effectiveness ratio of instrumenting vaccination programs based upon the use of Prevenar-13 and Synflorix® in the Mexican pediatric population was estimated by using a Markov's simulation model. The robustness of the conclusions reached on cost-effectiveness for both vaccines was assayed through an univariate and probabilistic sensitivity analysis that included all of the parameters considered by the model. Synflorix® was dominant over Prevenar-13 in the cost-utility analysis; the former generated more quality-adjusted life years at a lower cost and with a lower incremental cost-utility ratio. Based on the cost-effective analysis, Prevenar-13 generated more life years gained but at a higher cost. The use of Prevenar-13 originated a higher incremental cost-effectiveness ratio and, therefore, it was not cost-effective as compared with Synflorix®. Even though the simulations for Prevenar-13 and Synflorix® revealed both of them to be cost-effective when used to instrument pediatric vaccination campaigns in Mexico, Synflorix® had a better cost-utility/effectiveness profile. In addition, although Prevenar-13 and Synflorix® produced equivalent health outcomes, the overall analysis predicted that Synflorix® would save 360 million Mexican pesos, as compared with Prevenar-13. Copyright © 2016 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  17. "Estudia para que no te pase lo que a mi": Narrativas Culturales Sobre el Valor de la Escuela en Familias Mexicanas ("Study So That What Happened to Me Doesn't Happen to You": Cultural Narratives about the Value of Schooling in Mexican Families).

    ERIC Educational Resources Information Center

    Ramos, Claudia Saucedo

    2003-01-01

    Narratives used by parents in Mexican working-class families to motivate their children to study are examined for the advice offered and parental attitudes about the importance of school. The integration of contemporary pressures about the value of schooling is investigated, as well as the ways in which the value of schooling is being…

  18. Science and Technology Text Mining: Mexico Core Competencies

    DTIC Science & Technology

    2002-01-01

    GONZALEZ-HERNANDEZ--J CINVESTAV, IPN 66 NAIR--MTS UNAM 55 RAMIREZ-BON--R UNIV SONORA 47 13 PENA--JL CTR INVEST CIENTIFICA 43 ORTIZ--A UNAM 42...concentrated in physics and materials, with some emphasis on chemistry as well. All but one ( Revista Mexicana de Fisica) are English language...journals, and Revista Mexicana de Fisica is one of the most relevant peer reviewed physics journals in Latin America (27). It publishes papers in both

  19. Terrestrial and Celestial Cartography,

    DTIC Science & Technology

    1979-05-01

    projection of the constellation Norma into the constellation Lupus, but this projection is assigned to Circinus in the present repertory in conformity with...Arizona, Tucson, 1972) 69. Thirteen-Color Photometry of 1380 Bright Stars. H. L. Johnson, and R. I. Mitchell, Revista Mexicana de Astronomia y Astrofisica...1. 299 (1975) 90. A New Michelson Spec trophotometer System. H. L. Johnson, Revista Mexicana de Astronomia y Astrofisica, 2, 219 (1977) 91. An Atlas

  20. Combining Architecture-Centric Engineering with the Team Software Process

    DTIC Science & Technology

    2010-12-01

    Bursatec, the IT arm of La Bolsa Mexicana de Valores (the Mexican Stock Exchange), to replace its main online stock trading engine with one that...a project at Bursatec. 4.1 Project Summary (to Date) In early 2009 Bursatec, the IT development organization of the Bolsa Mexicana de Valores (BMV...Scale: An Experience Report from Pilot Projects in Mexico (CMU/SEI-2009-TR-011). Pittsburgh, PA: Software Engineering Institute, Carnegie Mellon

  1. Launching Latin America: International and Domestic Factors in National Space Programs

    DTIC Science & Technology

    2014-12-01

    venezuela.html. 265 R. Hernández et al., “Current Space Projects of the Bolivarian Republic of Venezuela,” Revista Mexicana de Astronomía Y...Hernández, R., R. Acevedo, F. Varela, and S. Otero. “Current Space Projects of the Bolivarian Republic of Venezuela.” Revista Mexicana de Astronomía Y

  2. Developmental time, longevity, and lifetime fertility of three introduced parasitoids of the mealybug Paracoccus marginatus (Hemiptera: Pseudococcidae).

    PubMed

    Amarasekare, Kaushalya G; Mannion, Catharine M; Epsky, Nancy D

    2012-10-01

    Developmental time, longevity, and lifetime fertility of three previously introduced parasitoids (Acerophagus papayae Noyes and Schauff, Anagyrus loecki Noyes and Menezes, and Pseudleptomastix mexicana Noyes and Schauff) (Hymenoptera: Encyrtidae) of the mealybug Paracoccus marginatus Williams and Granara de Willink (Hemiptera: Pseudococcidae) were studied in the laboratory to understand the outcome of their recovery in field studies conducted in the United States. The developmental time of both male and female A. papayae and A. loecki was shorter than the developmental time of male and female P. mexicana. Male parasitoids of all three species had a shorter developmental time than their females. All parasitoids had a shorter developmental time in adult-female mealybugs than in second instars. Mating status (unmated and mated) had no effect on the male longevity. Unmated and mated females that were not allowed to oviposit had similar longevity and lived longer than those that were allowed to oviposit. Virgin females produced male only progeny with higher number of males from A. loecki or P. mexicana than from A. papayae. The number of females and the cumulative progeny was smaller for A. papayae than for A. loecki or P. mexicana. The progeny sex ratio (proportion of females) was not different among the parasitoids. A. papayae had the shortest reproductive period followed by A. loecki and P. mexicana, respectively. This information is important in evaluating the efficiency, recovery and establishment of A. papayae, A. loecki, and P. mexicana.

  3. IN VIVO AND IN VITRO ANTILEISHMANIAL EFFECTS OF METHANOLIC EXTRACT FROM BARK OF BURSERA APTERA

    PubMed Central

    Nieto-Yañez, O. J.; Resendiz-Albor, A. A.; Ruiz-Hurtado, P. A.; Rivera-Yañez, N.; Rodriguez-Canales, M.; Rodriguez-Sosa, M.; Juarez-Avelar, I.; Rodriguez-Lopez, M. G.; Canales-Martinez, M. M.; Rodriguez-Monroy, M. A.

    2017-01-01

    Background: Cutaneous leishmaniasis lacks effective and well-tolerated treatments. The current therapies mainly rely on antimonial drugs that are inadequate because of their poor efficacy. Traditional medicine offers a complementary alternative for the treatment of various diseases. Additionally, several plants have shown success as anti-leishmanial agents. Therefore, we sought to evaluate the in vitro and in vivo activity of MEBA against Leishmania mexicana. Materials and Methods: Methanolic extract of B. aptera was obtained by macetration, after we determined in vitro anti-leishmanial activity of MEBA by MTT assay and the induced apoptosis in promastigotes by flow cytometry. To analyze the in vivo anti-leishmanial activity, we used infected mice that were treated and not treated with MEBA and we determined the levels of cytokines using ELISA. The phytochemical properties were determined by CG-MS and DPPH assay. Results: We determined of LC50 of 0.408 mg/mL of MEBA for in vitro anti-leishmanial activity. MEBA induced apoptosis in promastigotes (15.3% ± 0.86). Treated mice exhibited smaller lesions and contained significantly fewer parasites than did untreated mice; in addition, we found that IFN-γ and TNF-α increased in the sera of MEBA-treated mice. GC-MS analysis showed that podophyllotoxin was the most abundant compound. Evaluation of the activity by DPPH assay demonstrated an SC50 of 11.72 μg/mL. Conclusion: Based on the above data, it was concluded that MEBA is a good candidate in the search for new anti-leishmanial agents. PMID:28573235

  4. Modulation of Leishmania major aquaglyceroporin activity by a mitogen-activated protein kinase

    PubMed Central

    Mandal, Goutam; Sharma, Mansi; Kruse, Martin; Sander-Juelch, Claudia; Munro, Laura Anne; Wang, Yong; Vilg, Jenny Veide; Tamás, Markus J; Bhattacharjee, Hiranmoy; Wiese, Martin; Mukhopadhyay, Rita

    2012-01-01

    Summary Leishmania major aquaglyceroporin (LmjAQP1) adventitiously facilitates the uptake of antimonite [Sb(III)], an active form of Pentostam® or Glucantime®, which are the first line of defense against all forms of leishmaniasis. The present paper shows that LmjAQP1 activity is modulated by the mitogen-activated protein kinase, LmjMPK2. Leishmania parasites co-expressing LmjAQP1 and LmjMPK2 show increased Sb(III) uptake and increased Sb(III) sensitivity. When subjected to a hypo-osmotic stress, these cells show faster volume recovery than cells expressing LmjAQP1 alone. LmjAQP1 is phosphorylated in vivo at Thr197 and this phosphorylation requires LmjMPK2 activity. Lys42 of LmjMPK2 is critical for its kinase activity. Cells expressing altered T197A LmjAQP1 or K42A LmjMPK2 showed decreased Sb(III) influx and a slower volume recovery than cells expressing wild type proteins. Phosphorylation of LmjAQP1 led to a decrease in its turnover rate affecting LmjAQP1 activity. Although LmjAQP1 is localized to the flagellum of promastigotes, upon phosphorylation, it is relocalized to the entire surface of the parasite. L. mexicana promastigotes with an MPK2 deletion showed reduced Sb(III) uptake and slower volume recovery than wild type cells. This is the first report where a parasite aquaglyceroporin activity is post-translationally modulated by a MAP kinase. PMID:22779703

  5. Development of a New Antileishmanial Aziridine-2,3-Dicarboxylate-Based Inhibitor with High Selectivity for Parasite Cysteine Proteases

    PubMed Central

    Schad, Caroline; Baum, Ulrike; Frank, Benjamin; Dietzel, Uwe; Mattern, Felix; Gomes, Carlos; Ponte-Sucre, Alicia; Moll, Heidrun

    2015-01-01

    Leishmaniasis is one of the major neglected tropical diseases of the world. Druggable targets are the parasite cysteine proteases (CPs) of clan CA, family C1 (CAC1). In previous studies, we identified two peptidomimetic compounds, the aziridine-2,3-dicarboxylate compounds 13b and 13e, in a series of inhibitors of the cathepsin L (CL) subfamily of the papain clan CAC1. Both displayed antileishmanial activity in vitro while not showing cytotoxicity against host cells. In further investigations, the mode of action was characterized in Leishmania major. It was demonstrated that aziridines 13b and 13e mainly inhibited the parasitic cathepsin B (CB)-like CPC enzyme and, additionally, mammalian CL. Although these compounds induced cell death of Leishmania promastigotes and amastigotes in vitro, the induction of a proleishmanial T helper type 2 (Th2) response caused by host CL inhibition was observed in vivo. Therefore, we describe here the synthesis of a new library of more selective peptidomimetic aziridine-2,3-dicarboxylates discriminating between host and parasite CPs. The new compounds are based on 13b and 13e as lead structures. One of the most promising compounds of this series is compound s9, showing selective inhibition of the parasite CPs LmaCatB (a CB-like enzyme of L. major; also named L. major CPC) and LmCPB2.8 (a CL-like enzyme of Leishmania mexicana) while not affecting mammalian CL and CB. It displayed excellent leishmanicidal activities against L. major promastigotes (50% inhibitory concentration [IC50] = 37.4 μM) and amastigotes (IC50 = 2.3 μM). In summary, we demonstrate a new selective aziridine-2,3-dicarboxylate, compound s9, which might be a good candidate for future in vivo studies. PMID:26596939

  6. The mitochondrial FAD-dependent glycerol-3-phosphate dehydrogenase of Trypanosomatidae and the glycosomal redox balance of insect stages of Trypanosoma brucei and Leishmania spp.

    PubMed

    Guerra, Daniel G; Decottignies, Anabelle; Bakker, Barbara M; Michels, Paul A M

    2006-10-01

    The genes for the mitochondrial FAD-dependent glycerol-3-phosphate dehydrogenase were identified in Trypanosoma brucei and Leishmania major genomes. We have expressed the L. major gene in Saccharomyces cerevisiae and confirmed the subcellular localization and activity of the produced enzyme. Using cultured T. brucei procyclic and Leishmania mexicana promastigote cells with a permeabilized plasma membrane and containing intact glycosomes, it was shown that dihydroxyacetone phosphate is converted into pyruvate, and stimulates oxygen consumption, indicating that all components of the glycerol 3-phosphate/dihydoxyacetone phosphate shuttle between glycosomes and mitochondrion are present in these insect stages of both organisms. A computer model has been prepared for the energy and carbohydrate metabolism of these cells. It was used in an elementary mode analysis to get insight into the metabolic role of the shuttle in these insect-stage parasites. Our analysis suggests that the shuttle fulfils important roles for these organisms, albeit different from its well-known function in the T. brucei bloodstream form. It allows (1) a high yield of further metabolizable glycolytic products by decreasing the need to produce a secreted end product of glycosomal metabolism, succinate; (2) the consumption of glycerol and glycerol 3-phosphate derived from lipids; and (3) to keep the redox balance of the glycosome finely tuned due to a highly flexible and redundant system.

  7. [Epidemiological characteristics of American cutaneous leishmaniasis in an endemic region of the State of Bahia. III. Phlebotomine fauna].

    PubMed

    Vexenat, J A; Barretto, A C; Cuba, C C; Marsden, P D

    1986-01-01

    The phlebotomine fauna is highly varied in Três Braços, an endemic area of american cutaneous leishmaniasis, situated in the cacao growing region in the southeast of Bahia State, Brazil. Thirty spécies of the Lutzomyia genus were identified in 13,535 specimens collected between 1976 and 1984. Lutzomyia whitmani was the dominant species accounting for 99% of flies in the peridomicile and 97.5% of those caught in homes. In the forest the predominant species were Lu. ayrozai and Lu. yuilli. Lu. whitmani accounted for only 1.0% of the specimens examined. Lu. flaviscutellata, the proven vector of Leishmania mexicana amazonensis, was also collected in small numbers. Lu. wellcomei, a known vector of L. braziliensis braziliensis in the Serra dos Carajás, Pará, Brazil was not encountered in the Três Braços region where the parasite causing human infections is usually L.b. braziliensis. Although we have not encountered a natural infection with leishmanial promastigotes in 1,832 females of the various species examined, we discuss the probability that Lu. whitmani is the vector of L.b. braziliensis in the region maintaining transmission in dogs and man.

  8. Leishmania β-1,2-mannan is assembled on a mannose-cyclic phosphate primer

    PubMed Central

    Sernee, M. Fleur; Ralton, Julie E.; Dinev, Zoran; Khairallah, George N.; O’Hair, Richard A.; Williams, Spencer J.; McConville, Malcolm J.

    2006-01-01

    Infective stages of the protozoan parasite Leishmania spp. accumulate a class of β-1,2-mannan oligosaccharides as their major carbohydrate reserve material. Here, we describe the biosynthesis of Leishmania mannan. Mannan precursors were identified by metabolic labeling of Leishmania mexicana promastigotes with [3H]mannose. Label was initially incorporated into a phosphomannose primer and short phosphorylated β-1,2-mannan oligomers that were two to five residues long. Analysis of the mannan primer by Fourier transform ion-cyclotron resonance MS and various enzymatic and chemical treatments and comparison with authentic mannose (Man) phosphates indicated the presence of Man-α-1,4-cyclic phosphate. This primer was synthesized from Man-6-phosphate by means of Man-1-phosphate in a cell-free system. Short mannan chains containing the primer were subsequently dephosphorylated and then further elongated by GDP-Man-dependent transferases in vivo and in the cell-free system. The synthesis of this glycan primer likely constitutes a key regulatory step in mannan biosynthesis and is a potential target for antileishmanial drugs. PMID:16766650

  9. Metabolomic Analyses of Leishmania Reveal Multiple Species Differences and Large Differences in Amino Acid Metabolism

    PubMed Central

    Wang, Lijie; Zhang, Tong; Watson, David G.; Silva, Ana Marta; Coombs, Graham H.

    2015-01-01

    Comparative genomic analyses of Leishmania species have revealed relatively minor heterogeneity amongst recognised housekeeping genes and yet the species cause distinct infections and pathogenesis in their mammalian hosts. To gain greater information on the biochemical variation between species, and insights into possible metabolic mechanisms underpinning visceral and cutaneous leishmaniasis, we have undertaken in this study a comparative analysis of the metabolomes of promastigotes of L. donovani, L. major and L. mexicana. The analysis revealed 64 metabolites with confirmed identity differing 3-fold or more between the cell extracts of species, with 161 putatively identified metabolites differing similarly. Analysis of the media from cultures revealed an at least 3-fold difference in use or excretion of 43 metabolites of confirmed identity and 87 putatively identified metabolites that differed to a similar extent. Strikingly large differences were detected in their extent of amino acid use and metabolism, especially for tryptophan, aspartate, arginine and proline. Major pathways of tryptophan and arginine catabolism were shown to be to indole-3-lactate and arginic acid, respectively, which were excreted. The data presented provide clear evidence on the value of global metabolomic analyses in detecting species-specific metabolic features, thus application of this technology should be a major contributor to gaining greater understanding of how pathogens are adapted to infecting their hosts. PMID:26368322

  10. High Resolution Melting Analysis Targeting hsp70 as a Fast and Efficient Method for the Discrimination of Leishmania Species

    PubMed Central

    Zampieri, Ricardo Andrade; Laranjeira-Silva, Maria Fernanda; Muxel, Sandra Marcia; Stocco de Lima, Ana Carolina; Shaw, Jeffrey Jon; Floeter-Winter, Lucile Maria

    2016-01-01

    Background Protozoan parasites of the genus Leishmania cause a large spectrum of clinical manifestations known as Leishmaniases. These diseases are increasingly important public health problems in many countries both within and outside endemic regions. Thus, an accurate differential diagnosis is extremely relevant for understanding epidemiological profiles and for the administration of the best therapeutic protocol. Methods/Principal Findings Exploring the High Resolution Melting (HRM) dissociation profiles of two amplicons using real time polymerase chain reaction (real-time PCR) targeting heat-shock protein 70 coding gene (hsp70) revealed differences that allowed the discrimination of genomic DNA samples of eight Leishmania species found in the Americas, including Leishmania (Leishmania) infantum chagasi, L. (L.) amazonensis, L. (L.) mexicana, L. (Viannia) lainsoni, L. (V.) braziliensis, L. (V.) guyanensis, L. (V.) naiffi and L. (V.) shawi, and three species found in Eurasia and Africa, including L. (L.) tropica, L. (L.) donovani and L. (L.) major. In addition, we tested DNA samples obtained from standard promastigote culture, naturally infected phlebotomines, experimentally infected mice and clinical human samples to validate the proposed protocol. Conclusions/Significance HRM analysis of hsp70 amplicons is a fast and robust strategy that allowed for the detection and discrimination of all Leishmania species responsible for the Leishmaniases in Brazil and Eurasia/Africa with high sensitivity and accuracy. This method could detect less than one parasite per reaction, even in the presence of host DNA. PMID:26928050

  11. High Resolution Melting Analysis Targeting hsp70 as a Fast and Efficient Method for the Discrimination of Leishmania Species.

    PubMed

    Zampieri, Ricardo Andrade; Laranjeira-Silva, Maria Fernanda; Muxel, Sandra Marcia; Stocco de Lima, Ana Carolina; Shaw, Jeffrey Jon; Floeter-Winter, Lucile Maria

    2016-02-01

    Protozoan parasites of the genus Leishmania cause a large spectrum of clinical manifestations known as Leishmaniases. These diseases are increasingly important public health problems in many countries both within and outside endemic regions. Thus, an accurate differential diagnosis is extremely relevant for understanding epidemiological profiles and for the administration of the best therapeutic protocol. Exploring the High Resolution Melting (HRM) dissociation profiles of two amplicons using real time polymerase chain reaction (real-time PCR) targeting heat-shock protein 70 coding gene (hsp70) revealed differences that allowed the discrimination of genomic DNA samples of eight Leishmania species found in the Americas, including Leishmania (Leishmania) infantum chagasi, L. (L.) amazonensis, L. (L.) mexicana, L. (Viannia) lainsoni, L. (V.) braziliensis, L. (V.) guyanensis, L. (V.) naiffi and L. (V.) shawi, and three species found in Eurasia and Africa, including L. (L.) tropica, L. (L.) donovani and L. (L.) major. In addition, we tested DNA samples obtained from standard promastigote culture, naturally infected phlebotomines, experimentally infected mice and clinical human samples to validate the proposed protocol. HRM analysis of hsp70 amplicons is a fast and robust strategy that allowed for the detection and discrimination of all Leishmania species responsible for the Leishmaniases in Brazil and Eurasia/Africa with high sensitivity and accuracy. This method could detect less than one parasite per reaction, even in the presence of host DNA.

  12. Development and validation of four Leishmania species constitutively expressing GFP protein. A model for drug discovery and disease pathogenesis studies.

    PubMed

    Patel, Asha Parbhu; Deacon, Andrew; Getti, Giulia

    2014-04-01

    Green fluorescent protein (GFP)-parasite transfectants have been widely used as a tool for studying disease pathogenesis in several protozoan models and their application in drug screening assays has increased rapidly. In the past decade, the expression of GFP has been established in several Leishmania species, mostly for in vitro studies. The current work reports generation of four transgenic parasites constitutively expressing GFP (Leishmania mexicana, Leishmania aethiopica, Leishmania tropica and Leishmania major) and their validation as a representative model of infection. This is the first report where stable expression of GFP has been achieved in L. aethiopica and L. tropica. Integration of GFP was accomplished through homologous recombination of the expression construct, pRib1.2αNEOαGFP downstream of the 18S rRNA promoter in all species. A homogeneous and high level expression of GFP was detected in both the promastigote and the intracellular amastigote stages. All transgenic species showed the same growth pattern, ability to infect mammalian host cells and sensitivity to reference drugs as their wild type counterparts. All four transgenic Leishmania are confirmed as models for in vitro and possibly in vivo infections and represent an ideal tool for medium throughput testing of compound libraries.

  13. Phylogenetic and Taxonomic Status Analyses of the Abaso Section from Multiple Nuclear Genes and Plastid Fragments Reveal New Insights into the North America Origin of Populus (Salicaceae)

    PubMed Central

    Liu, Xia; Wang, Zhaoshan; Shao, Wenhao; Ye, Zhanyang; Zhang, Jianguo

    2017-01-01

    Although, the Abaso section is widely accepted as an independent section, the taxonomic status of Populus mexicana (section Abaso) has not yet been resolved due to the limited availability markers and/or the lack of P. mexicana specimens in previous studies. Thirty-one poplar species that represent six sections of the Populus genus were sampled, and 23 single-copy nuclear DNA and 34 chloroplast fragments were sequenced. The present study obtained two updated phylogenies of Populus. We found that monophyly of the genus Populus is strongly supported by nuclear and plastid gene, which is consistent with previous studies. P. mexicana, diverged first in the nuclear DNA tree, which occupied the basal position, implying that the section Abaso may be the most ancestral lineage in extant populous species. Given that the short branches and low statistical support for the divergence of sections Abaso and Turanga, this observation probably indicated that a rapid radiation evolution following the early split of the genus Populus. In the plastid tree, P. mexicana clustered with modern-day species of section Tacamahaca in the plastid tree. Based on cytoplasmic and single-copy nuclear marker sequences, we hypothesized that chloroplast capture resulted in the inconsistent position of P. mexicana between the phylogenetic trees. Given the first unequivocal records of poplar fossils from the Eocene with similar leaf morphology to the extant P. mexicana and the phylogenetic positions of P. mexicana in our study, we support the hypothesis that the Populus genus originated in North America, which will provide new insights to the development of the origin of Populus species. PMID:28101098

  14. The Genomic Signature of Crop-Wild Introgression in Maize

    PubMed Central

    Hufford, Matthew B.; Lubinksy, Pesach; Pyhäjärvi, Tanja; Devengenzo, Michael T.; Ellstrand, Norman C.; Ross-Ibarra, Jeffrey

    2013-01-01

    The evolutionary significance of hybridization and subsequent introgression has long been appreciated, but evaluation of the genome-wide effects of these phenomena has only recently become possible. Crop-wild study systems represent ideal opportunities to examine evolution through hybridization. For example, maize and the conspecific wild teosinte Zea mays ssp. mexicana (hereafter, mexicana) are known to hybridize in the fields of highland Mexico. Despite widespread evidence of gene flow, maize and mexicana maintain distinct morphologies and have done so in sympatry for thousands of years. Neither the genomic extent nor the evolutionary importance of introgression between these taxa is understood. In this study we assessed patterns of genome-wide introgression based on 39,029 single nucleotide polymorphisms genotyped in 189 individuals from nine sympatric maize-mexicana populations and reference allopatric populations. While portions of the maize and mexicana genomes appeared resistant to introgression (notably near known cross-incompatibility and domestication loci), we detected widespread evidence for introgression in both directions of gene flow. Through further characterization of these genomic regions and preliminary growth chamber experiments, we found evidence suggestive of the incorporation of adaptive mexicana alleles into maize during its expansion to the highlands of central Mexico. In contrast, very little evidence was found for adaptive introgression from maize to mexicana. The methods we have applied here can be replicated widely, and such analyses have the potential to greatly inform our understanding of evolution through introgressive hybridization. Crop species, due to their exceptional genomic resources and frequent histories of spread into sympatry with relatives, should be particularly influential in these studies. PMID:23671421

  15. Genetic evidence of enzootic leishmaniasis in a stray canine and Texas mouse from sites in west and central Texas.

    PubMed

    Kipp, Evan J; Mariscal, Jacqueline; Armijos, Rodrigo X; Weigel, Margaret; Waldrup, Kenneth

    2016-10-01

    We detected Leishmania mexicana in skin biopsies taken from a stray canine (Canis familiaris) and Texas mouse (Peromyscus attwateri) at two ecologically disparate sites in west and central Texas using polymerase chain reaction (PCR). A single PCR-positive dog was identified from a sample of 96 stray canines and was collected in a peri-urban area in El Paso County, Texas. The PCR-positive P. attwateri was trapped at a wildlife reserve in Mason County, Texas, from a convenience sample of 20 sylvatic mammals of different species. To our knowledge, this represents the first description of L. mexicana in west Texas and extends the known geographic range of the parasite to an area that includes the arid Chihuahuan Desert. Our finding of L. mexicana in P. attwateri represents a new host record and is the first description of the parasite in a wild peromyscid rodent in the United States.

  16. Genetic evidence of enzootic leishmaniasis in a stray canine and Texas mouse from sites in west and central Texas

    PubMed Central

    Kipp, Evan J; Mariscal, Jacqueline; Armijos, Rodrigo X; Weigel, Margaret; Waldrup, Kenneth

    2016-01-01

    We detected Leishmania mexicana in skin biopsies taken from a stray canine (Canis familiaris) and Texas mouse (Peromyscus attwateri) at two ecologically disparate sites in west and central Texas using polymerase chain reaction (PCR). A single PCR-positive dog was identified from a sample of 96 stray canines and was collected in a peri-urban area in El Paso County, Texas. The PCR-positive P. attwateri was trapped at a wildlife reserve in Mason County, Texas, from a convenience sample of 20 sylvatic mammals of different species. To our knowledge, this represents the first description of L. mexicana in west Texas and extends the known geographic range of the parasite to an area that includes the arid Chihuahuan Desert. Our finding of L. mexicana in P. attwateri represents a new host record and is the first description of the parasite in a wild peromyscid rodent in the United States. PMID:27759765

  17. The Comparative Genomics and Phylogenomics of Leishmania amazonensis Parasite

    PubMed Central

    Tschoeke, Diogo A; Nunes, Gisele L; Jardim, Rodrigo; Lima, Joana; Dumaresq, Aline SR; Gomes, Monete R; de Mattos Pereira, Leandro; Loureiro, Daniel R; Stoco, Patricia H; de Matos Guedes, Herbert Leonel; de Miranda, Antonio Basilio; Ruiz, Jeronimo; Pitaluga, André; Silva, Floriano P; Probst, Christian M; Dickens, Nicholas J; Mottram, Jeremy C; Grisard, Edmundo C; Dávila, Alberto MR

    2014-01-01

    Leishmaniasis is an infectious disease caused by Leishmania species. Leishmania amazonensis is a New World Leishmania species belonging to the Mexicana complex, which is able to cause all types of leishmaniasis infections. The L. amazonensis reference strain MHOM/BR/1973/M2269 was sequenced identifying 8,802 codifying sequences (CDS), most of them of hypothetical function. Comparative analysis using six Leishmania species showed a core set of 7,016 orthologs. L. amazonensis and Leishmania mexicana share the largest number of distinct orthologs, while Leishmania braziliensis presented the largest number of inparalogs. Additionally, phylogenomic analysis confirmed the taxonomic position for L. amazonensis within the “Mexicana complex”, reinforcing understanding of the split of New and Old World Leishmania. Potential non-homologous isofunctional enzymes (NISE) were identified between L. amazonensis and Homo sapiens that could provide new drug targets for development. PMID:25336895

  18. The Comparative Genomics and Phylogenomics of Leishmania amazonensis Parasite.

    PubMed

    Tschoeke, Diogo A; Nunes, Gisele L; Jardim, Rodrigo; Lima, Joana; Dumaresq, Aline Sr; Gomes, Monete R; de Mattos Pereira, Leandro; Loureiro, Daniel R; Stoco, Patricia H; de Matos Guedes, Herbert Leonel; de Miranda, Antonio Basilio; Ruiz, Jeronimo; Pitaluga, André; Silva, Floriano P; Probst, Christian M; Dickens, Nicholas J; Mottram, Jeremy C; Grisard, Edmundo C; Dávila, Alberto Mr

    2014-01-01

    Leishmaniasis is an infectious disease caused by Leishmania species. Leishmania amazonensis is a New World Leishmania species belonging to the Mexicana complex, which is able to cause all types of leishmaniasis infections. The L. amazonensis reference strain MHOM/BR/1973/M2269 was sequenced identifying 8,802 codifying sequences (CDS), most of them of hypothetical function. Comparative analysis using six Leishmania species showed a core set of 7,016 orthologs. L. amazonensis and Leishmania mexicana share the largest number of distinct orthologs, while Leishmania braziliensis presented the largest number of inparalogs. Additionally, phylogenomic analysis confirmed the taxonomic position for L. amazonensis within the "Mexicana complex", reinforcing understanding of the split of New and Old World Leishmania. Potential non-homologous isofunctional enzymes (NISE) were identified between L. amazonensis and Homo sapiens that could provide new drug targets for development.

  19. "Hacer o no hacer" (To do or not to do). Mexican Foreign Policy and UN Peacekeeping Operations in the 21st Century

    DTIC Science & Technology

    2006-12-01

    two documents: Los Sentimientos de la Nación (The Nation’s Feelings), written by José María Morelos y Pavón14 (1813); and the Decreto Constitucional ...one of the main leaders of Mexico’s struggle for independence. 15 Decreto Constitucional para la Libertad de la América Mexicana. As cited by the... Constitucional para la Libertad de la América Mexicana. 17 Acta Constitutiva de la Federación, decree of January 31, 1824. As cited by the Instituto de

  20. International pact limits airline's liability for needle injury.

    PubMed

    1998-09-18

    [Name removed] sued Mexicana de Aviacion S.A. de C.V. for liability after he was pricked in the leg by a hypodermic needle that was found in the plane's seat cushion. A Federal judge ruled that since liability claims resulting from injuries on international flights are covered by the Warsaw Convention, [name removed] could not recover more than $75,000 for his fear-of-AIDS liability lawsuit. The judge also stated that the Signature Support Corporation, a second defendant named in the case because they are subcontracted to clean Mexicana's planes, may also be covered by the Warsaw Convention.

  1. The foliicolous lichen flora of Mexico IV: a new, foliicolous species of Pyrenothrix (Chaetothyriales: Pyrenothrichaceae).

    PubMed

    Herrera-Campos, María de los Angeles; Huhndorf, Sabine; Lücking, Robert

    2005-01-01

    Pyrenothrix mexicana Herrera-Campos, Huhndorf & Lücking spec. nova is described from leaves in the upper montane rainforest of Oaxaca State, Mexico. It is the second species in the genus Pyrenothrix Riddle, established at the beginning of the twentieth century for the single species, P. nigra Riddle, a corticolous lichen restricted to southeastern United States. Both taxa have the same thallus and perithecial morphology and anatomy, but P. mexicana differs by its longer, transversally septate ascospores. The perithecial anatomy of Pyrenothrix is documented and its systematic affinities are discussed, and we conclude that the family Pyrenothrichaceae Zahlbr. should be placed in the order Chaetothyriales.

  2. Tranzschelia in the Americas revisited: two new species and notes on the Tranzschelia thalictri complex.

    PubMed

    Scholler, Markus; Abbasi, Mehrdad; Friedrich, Frank

    2014-01-01

    Two new species of Tranzschelia (Pucciniales) are described from the Americas. Tranzschelia pseudofusca is a microcyclic species on Anemone spp. (Ranunculaceae) with North American distribution. T. mexicana on Prunus salicifolia (Rosaceae) is found in Colombia, Ecuador and Mexico. It is assumed that T. mexicana is a macrocyclic host-alternating species. T. thalictri, a holarctic microcyclic species, has variable morphology and probably is an aggregate of related species. Specimens are documented with scanning electron microscopy (ESEM) and light microscopy including a simple new technique to illuminate urediniospore germ pores. Results are discussed with respect to similar species, distribution and life-cycle characters. A key for American species on telial hosts is provided.

  3. A haploid-diploid-triploid mosaic of the Amazon molly, Poecilia formosa.

    PubMed

    Lampert, K P; Steinlein, C; Schmid, M; Fischer, P; Schartl, M

    2007-01-01

    We report the finding of the first haploid-diploid-triploid mosaic fish from the family Poeciliidae. The animal was derived from a laboratory cross of a female F1 hybrid of Poecilia mexicana and P. latipinna with a male from an ornamental strain derived from P. mexicana and P. sphenops (Black molly). It was identified because of its unusual pigmentation pattern and molecular methods (flow cytometry, NOR staining) confirmed its mosaic genotype. The mode of mosaic formation and the possible importance for poeciliid fish evolution are discussed. Copyright (c) 2007 S. Karger AG, Basel.

  4. Use of DNA-based diagnostic methods for human leishmaniasis in Minas Gerais, Brazil.

    PubMed

    de Andrade, A S; Gomes, R F; Fernandes, O; de Melo, M N

    2001-03-30

    DNA hybridisation was used to type 26 samples from lesions of human patients from the Rio Doce Valley (Minas Gerais, Brazil) clinically diagnosed as having cutaneous leishmaniasis, using kinetoplast DNA (kDNA) cloned mini-circle probes specific for the Leishmania mexicana and Leishmania braziliensis complexes. All samples were found to belong to the L. braziliensis complex. When biopsies were pressed directly onto touch blot membranes 38.5% of the samples were positive. The positivity and specificity obtained were both 100% when cultured blotted parasites were used. The results were confirmed by polymerase chain reaction (PCR) analysis using primers specific for the L. mexicana and L. braziliensis complexes.

  5. Immunization with the DNA-encoding N-terminal domain of proteophosphoglycan of Leishmania donovani generates Th1-type immunoprotective response against experimental visceral leishmaniasis.

    PubMed

    Samant, Mukesh; Gupta, Reema; Kumari, Shraddha; Misra, Pragya; Khare, Prashant; Kushawaha, Pramod Kumar; Sahasrabuddhe, Amogh Anant; Dube, Anuradha

    2009-07-01

    Leishmania produce several types of mucin-like glycoproteins called proteophosphoglycans (PPGs) which exist as secretory as well as surface-bound forms in both promastigotes and amastigotes. The structure and function of PPGs have been reported to be species and stage specific as in the case of Leishmania major and Leishmania mexicana; there has been no such information available for Leishmania donovani. We have recently demonstrated that PPG is differentially expressed in sodium stibogluconate-sensitive and -resistant clinical isolates of L. donovani. To further elucidate the structure and function of the ppg gene of L. donovani, a partial sequence of its N-terminal domain of 1.6 kb containing the majority of antigenic determinants, was successfully cloned and expressed in prokaryotic as well as mammalian cells. We further evaluated the DNA-encoding N-terminal domain of the ppg gene as a vaccine in golden hamsters (Mesocricetus auratus) against the L. donovani challenge. The prophylactic efficacy to the tune of approximately 80% was observed in vaccinated hamsters and all of them could survive beyond 6 mo after challenge. The efficacy was supported by a surge in inducible NO synthase, IFN-gamma, TNF-alpha, and IL-12 mRNA levels along with extreme down-regulation of TGF-beta, IL-4, and IL-10. A rise in the level of Leishmania-specific IgG2 was also observed which was indicative of enhanced cellular immune response. The results suggest the N-terminal domain of L. donovani ppg as a potential DNA vaccine against visceral leishmaniasis.

  6. In vitro and in vivo efficacy of ether lipid edelfosine against Leishmania spp. and SbV-resistant parasites.

    PubMed

    Varela-M, Rubén E; Villa-Pulgarin, Janny A; Yepes, Edward; Müller, Ingrid; Modolell, Manuel; Muñoz, Diana L; Robledo, Sara M; Muskus, Carlos E; López-Abán, Julio; Muro, Antonio; Vélez, Iván D; Mollinedo, Faustino

    2012-01-01

    The leishmaniases are a complex of neglected tropical diseases caused by more than 20 Leishmania parasite species, for which available therapeutic arsenal is scarce and unsatisfactory. Pentavalent antimonials (SbV) are currently the first-line pharmacologic therapy for leishmaniasis worldwide, but resistance to these compounds is increasingly reported. Alkyl-lysophospoholipid analogs (ALPs) constitute a family of compounds with antileishmanial activity, and one of its members, miltefosine, has been approved as the first oral treatment for visceral and cutaneous leishmaniasis. However, its clinical use can be challenged by less impressive efficiency in patients infected with some Leishmania species, including L. braziliensis and L. mexicana, and by proneness to develop drug resistance in vitro. We found that ALPs ranked edelfosine>perifosine>miltefosine>erucylphosphocholine for their antileishmanial activity and capacity to promote apoptosis-like parasitic cell death in promastigote and amastigote forms of distinct Leishmania spp., as assessed by proliferation and flow cytometry assays. Effective antileishmanial ALP concentrations were dependent on both the parasite species and their development stage. Edelfosine accumulated in and killed intracellular Leishmania parasites within macrophages. In vivo antileishmanial activity was demonstrated following oral treatment with edelfosine of mice and hamsters infected with L. major, L. panamensis or L. braziliensis, without any significant side-effect. Edelfosine also killed SbV-resistant Leishmania parasites in in vitro and in vivo assays, and required longer incubation times than miltefosine to generate drug resistance. Our data reveal that edelfosine is the most potent ALP in killing different Leishmania spp., and it is less prone to lead to drug resistance development than miltefosine. Edelfosine is effective in killing Leishmania in culture and within macrophages, as well as in animal models infected with different

  7. Development in Mexico and Central America. Fulbright-Hays Summer Seminars Abroad Program. Summer 1991.

    ERIC Educational Resources Information Center

    Institute of International Education, New York, NY.

    This document features writings and curriculum projects by teachers who traveled to Mexico and Central America in the summer of 1991 as members of a Fulbright-Hays Summer Seminar. The following items are among the 20 included: Curriculum Project: "'Escritoras Mexicanas Contemporaneas': A Survey of Mexican Women Fiction Writers" (Laura J.…

  8. Recommended Species for Vegetative Stabilization of Training Lands in Arid and Semi-Arid Environments

    DTIC Science & Technology

    1985-09-01

    semibacata Awnless bush sunflower Helianthus sp. Bahia grass Paspalum notatum Barley Hordeum vulgare Basin wildrye Elymus cinereus Bearded wheatgrass...Boer lovegrass Eragrostis curvuLa *Brittlebush Encelia farinosa *Brome grasses Bromus spp. Buckwheat s Eriogonum spp. Buffalograss Buchloe dactyloides...mexicana *Millets Panicum spp. Mountain brome Bromus montanum Mountain mahogany Gercocarpus montanus *Mountain penstenion Penstemon montanus *Muhly grasses

  9. Mexico: Neighbor in Transition. Foreign Policy Association Headline Series, No. 267.

    ERIC Educational Resources Information Center

    Smith, Peter H.

    One of a series of booklets on world issues, this five-part document presents information about Mexico. Part one examines Mexican history from Cortez to Madero. Emphasis is placed on the revolution era (1910-1920) and the creation of two political parties: the Partido de la Revolucion Mexicana (Mexican Revolutionary Party or PRM) and the Partido…

  10. Mycosphaerella species associated with Eucalyptus in south-western Australia: new species, new records and a key.

    PubMed

    Maxwell, Aaron; Dell, Bernie; Neumeister-Kemp, Heike G; St J Hardy, Giles E

    2003-03-01

    Mycosphaerella ambiphylla sp. nov. (anamorph: Phaeophleospora) and Mycosphaerella aurantia sp. nov., are described from diseased Eucalyptus globulus leaves. In addition, a new fungal record in Australia, M. mexicana, and two new records for Western Australia, M. gregaria and M. parva, are discussed. A key is provided to Mycosphaerella species on E. globulus in Western Australia.

  11. Health Data Publications No. 30. Burma (Union of Burma)

    DTIC Science & Technology

    1966-01-01

    is usually unsatisfactory. It is not uncommon for adults as well as children to urinate or defecate in the streets. In rural areas excreta are usually...insecticidal Anamirta cocculus hong stimulant, antidote picrotoxin (poison berry) in barbiturate poisoning Argemone mexicana khyaa emetic and carthetic berberine

  12. Leluthia astigma (Ashmead)(Hymenoptera: Braconidae: Doryctinae)as a parasitoid of Agrilus planipennis Fairmaire(Coleoptera: Buprestidae: Agrilinae),with assessment of host associations for Nearctic species of Leluthia Cameron

    USDA-ARS?s Scientific Manuscript database

    The validity of host and host plant records are assessed for Leluthia astigma (Ashmead), Leluthia floridensis Marsh, and Leluthia mexicana Cameron, the three known species of Leluthia Cameron in the Nearctic Region. Leluthia astigma is reported from the exotic invasive pest Agrilus planipennis Fairm...

  13. Between Scylla and Charybdis: Constructing the Nicaraguan Army

    DTIC Science & Technology

    2009-02-18

    City: Organizacion Editorial Mexicana, 1992), 116. 31 Ruhl, “Civil-Military Relations in Post-Sandinista Nicaragua”, 120. 32 Ortega Saavedra...Codigo de organizacion , jurisdiccion, y prevision social militar, (Bogota: Editorial Hispamer, 1996), 5. 38 Ortega Saavedra, Nicaragua: Revolucion y

  14. "Mexico in Transition." Curriculum Units.

    ERIC Educational Resources Information Center

    Oregon Univ., Eugene. Foreign Language Resource Center.

    These curriculum units were developed in a National Endowment for the Humanities 1994 summer seminar "Mexico in Transition." The 23 lessons are written in Spanish. Lessons are entitled: (1) "La Migracion Mexicana Vista a Traves del Cuento 'Paso del Norte' de Juan Rulfo" (Jose Jorge Armendariz); (2) "Los Grupos Indigenas de…

  15. Emergence and Influence of the Zapatista Social Netwar

    DTIC Science & Technology

    2001-01-01

    Influence of the Zapatista Social Netwar 193 tics , depending on the country and region in which it occurs. Chia- pas, partly because...Clases Populares y las Organizaciones no Gubernamentales,” in Mario B. Monroy (ed.), Pensar Chiapas, Repensar México: Reflexiones de las ONGs Mexicanas

  16. Preface to "Should animal welfare be law or market driven?"

    USDA-ARS?s Scientific Manuscript database

    The Bioethics Symposium, entitled “Should animal welfare be law or market driven?” was held at the joint annual meeting of the American Dairy Science Association, American Society of Animal Science, Poultry Science Association, Asociación Mexicana de Producción Animal, and Canadian Society of Animal...

  17. Mexico: Neighbor in Transition. Foreign Policy Association Headline Series, No. 267.

    ERIC Educational Resources Information Center

    Smith, Peter H.

    One of a series of booklets on world issues, this five-part document presents information about Mexico. Part one examines Mexican history from Cortez to Madero. Emphasis is placed on the revolution era (1910-1920) and the creation of two political parties: the Partido de la Revolucion Mexicana (Mexican Revolutionary Party or PRM) and the Partido…

  18. Evaluation of toxicity of plant extracts against vector of lymphatic filariasis, Culex quinquefasciatus.

    PubMed

    Sakthivadivel, M; Eapen, Alex; Dash, A P

    2012-03-01

    Conventional insecticides are generally used as larvicides to control Culex quinquefasciatus, vector of lymphatic filariasis. This study was undertaken to evaluate the larvicidal activity of some potential larvicidal plants leaf extracts against Cx. quinquefasciatus larvae. The toxic effects of petroleum ether leaf extracts of plants viz., Argemone mexicana (Mexican prickly poppy), Clausena dentata (Dentate), Cipadessa baccifera (Rana bili), Dodonaea angustifolia (Hop bush) and Melia dubia (Pride of India) were evaluated under laboratory conditions in individual and in combination against 3 rd - 4 th instar larvae of Cx. quinquefasciatus. The results indicated that among the selected plants, A. mexicana showed maximum larvicidal activity with an LC 50 value of 48.89 ppm. Its toxicity was enhanced when the extract was mixed (1:1) with that of C. dentata as the LC 50 value became 28.60 ppm indicating synergistic action of A. mexicana. Our results showed high larvicidal potential in A. mexicana leaf extract, and it also showed additive effect when mixed with C. dentata extract.

  19. Evaluation of toxicity of plant extracts against vector of lymphatic filariasis, Culex quinquefasciatus

    PubMed Central

    Sakthivadivel, M.; Eapen, Alex; Dash, A.P.

    2012-01-01

    Background & objectives: Conventional insecticides are generally used as larvicides to control Culex quinquefasciatus, vector of lymphatic filariasis. This study was undertaken to evaluate the larvicidal activity of some potential larvicidal plants leaf extracts against Cx. quinquefasciatus larvae. Methods: The toxic effects of petroleum ether leaf extracts of plants viz., Argemone mexicana (Mexican prickly poppy), Clausena dentata (Dentate), Cipadessa baccifera (Rana bili), Dodonaea angustifolia (Hop bush) and Melia dubia (Pride of India) were evaluated under laboratory conditions in individual and in combination against 3rd - 4th instar larvae of Cx. quinquefasciatus. Results: The results indicated that among the selected plants, A. mexicana showed maximum larvicidal activity with an LC50 value of 48.89 ppm. Its toxicity was enhanced when the extract was mixed (1:1) with that of C. dentata as the LC50 value became 28.60 ppm indicating synergistic action of A. mexicana. Interpretation & conclusions: Our results showed high larvicidal potential in A. mexicana leaf extract, and it also showed additive effect when mixed with C. dentata extract. PMID:22561628

  20. Role Perceptions of Hispanic and Mainstream Navy Recruits.

    DTIC Science & Technology

    1982-12-01

    eye-views of life in an urban barrio. In J. Helm (Ed.), Spanish speaking people in the United States. Seattle: Uni- versity of Washington Press, 1968...la mujer Mexicana? Mexico City: Instituto Mexicano de Estudios Sociales, 1969. Linton, R. The study of man. New York: Appleton-Century, 1936

  1. Efficiency and establishment of three introduced parasitoids of the mealybug Paracoccus marginatus (Hemiptera: Pseudococcidae)

    USDA-ARS?s Scientific Manuscript database

    A study on the efficiency and establishment of three previously introduced parasitoids (Acerophagus papayae, Anagyrus loecki, and Pseudleptomastix mexicana) to control the mealybug Paracoccus marginatus was made in 2005 and 2006, at three locations in Homestead (Miami-Dade County), Florida. In each ...

  2. Agricultural Policy and Child Health in Rural Mexico.

    ERIC Educational Resources Information Center

    Brown, Antoinette B.; Partridge, William L.

    1987-01-01

    Reports on the impact on malnutrition of Mexico's Sistema de Alementacion Mexicana (SAM) program, which tried to make the country self-sufficient in basic foods. Concludes that the food problem in Mexico is not so much one of production as it is a problem of distribution and consumption. (PS)

  3. Department of Defense Natural Resources Program: Songbird Nest Boxes. Section 5.1.8., US Army Corps of Engineers Wildlife Resources Management Manual

    DTIC Science & Technology

    1988-11-01

    Western bluebird (S. mexicana ) Brown creeper (Certhia zmericana) - infrequent use Chickadees and titmice (Parus spp.) Black-capped chickadee (P...cav- ities were occupied (McComb and Noble 1981b). Herpetofauna such as treefrogs and skinks were also found in boxes more often than in natural

  4. Caterpillars of Eumaeus childrenae (Lepidoptera: Lycaenidae) feeding on two species of cycads (Zamiaceae) in the Huasteca region, Mexico.

    PubMed

    Contreras-Medina, Raúl; Ruiz-Jiménez, Carlos A; Luna Vega, Isolda

    2003-03-01

    There are few genera of butterflies that feed on cycads. Among them the genus Eumaeus (Lycaenidae) presents aposematic coloration in all its life stages. In this work we report for the first time the herbivory of young leaflets of Ceratozamia mexicana and Zamia fischeri (Zamiaceae) by caterpillars of E. childrenae in their natural habitat in the Huasteca region, Mexico.

  5. Even beyond the Local Community: A Close Look at Latina Youths' Return Trips to Mexico

    ERIC Educational Resources Information Center

    Sanchez, Patricia

    2009-01-01

    Drawing from nearly four years of qualitative research, this article examines the lives of three second-generation mexicanas living in northern California who maintain close ties to their families' natal communities in Mexico. This ethnographic portrait outlines the contours of belonging in these spaces, including the affection and close…

  6. The Geography Olympiad in Mexico

    ERIC Educational Resources Information Center

    Garcia-Garcia, Fernando

    2007-01-01

    The formal organisation of science Olympiads in Mexico dates from 1987, when a national contest on Mathematics was held in order to identify a team to represent the country in the International Mathematics Olympiad. In 1991, the Mexican Academy of Sciences ("Academia Mexicana de Ciencias"-AMC) created the National Science Olympiads…

  7. Collective Memory of Violence of the Female Brown Body: A Decolonial Feminist Public Pedagogy Engagement with the Feminicides

    ERIC Educational Resources Information Center

    Trinidad Galván, Ruth

    2016-01-01

    Feminists have consistently engaged with ontological and epistemological issues about what counts as knowledge, based on whose worldview, and what knowledge and worldviews remain unrecognised or ignored. Utilising Mexicana and Chicana fictional and conceptual writings and public art installations on the Juárez feminicides, the article focuses on…

  8. Field assessment of three introduced parasitoids of Paracoccus marginatus (Hemiptera: Pseudococcidae)

    USDA-ARS?s Scientific Manuscript database

    Abstract: Field assessment of the ability of three introduced parasitoids (Acerophagus papayae Noyes and Schauff, Anagyrus loecki Noyes, and Pseudleptomastix mexicana Noyes and Schauff) to control Paracoccus marginatus Williams and Granara de Willink was investigated in 2005 and 2006 in three locat...

  9. Triennial Growth Symposium: Dietary regulation of growth development

    USDA-ARS?s Scientific Manuscript database

    The 2010 Triennial Growth Symposium was held immediately before the Joint Annual Meeting of the American Dairy Science Association, Poultry Science Association, Asociación Mexicana de Producción Animal, Canadian Society of Animal Science, Western Section American Society of Animal Science, and Ameri...

  10. Screening for Inhibitors of Essential Leishmania Glucose Transporters

    DTIC Science & Technology

    2012-07-01

    Leishmania Glucose Transporters PRINCIPAL INVESTIGATOR: Scott M. Landfear, Ph.D. CONTRACTING ORGANIZATION: Oregon Health & Science...3. DATES COVERED 1 JUL 2011 - 30 JUN 2012 4. TITLE AND SUBTITLE Screening for Inhibitors of Essential Leishmania Glucose Transporters...function as selective inhibitors of the essential glucose transporters of the parasite Leishmania mexicana. To identify such compounds, a cell growth

  11. Collective Memory of Violence of the Female Brown Body: A Decolonial Feminist Public Pedagogy Engagement with the Feminicides

    ERIC Educational Resources Information Center

    Trinidad Galván, Ruth

    2016-01-01

    Feminists have consistently engaged with ontological and epistemological issues about what counts as knowledge, based on whose worldview, and what knowledge and worldviews remain unrecognised or ignored. Utilising Mexicana and Chicana fictional and conceptual writings and public art installations on the Juárez feminicides, the article focuses on…

  12. Phlebotomine Vectors of Human Disease.

    DTIC Science & Technology

    1983-12-30

    different. We refrain from naming this specimen until more material becomes available. 12. Lutzomyia olmeca bicolor Fairchild and Theodor 1971...Castillo (1958) and Arzube (1960). Lutzomyia olmeca bicolor is the suspected vector of Leishmania mexicana aristedesi among rodents and marsupials in

  13. A comparison of the breeding ecology of birds nesting in boxes and tree cavities

    Treesearch

    Kathryn L. Purcell; Jared Verner; Lewis W. Oring

    1997-01-01

    We compared laying date, nesting success, clutch size, and productivity of four bird species that nest in boxes and tree cavities to examine whether data from nest boxes are comparable with data from tree cavities. Western Bluebirds (Sialia mexicana) gained the most advantage from nesting in boxes. They initiated egg laying earlier, had higher nesting success, lower...

  14. "Mexico in Transition." Curriculum Units.

    ERIC Educational Resources Information Center

    Oregon Univ., Eugene. Foreign Language Resource Center.

    These curriculum units were developed in a National Endowment for the Humanities 1994 summer seminar "Mexico in Transition." The 23 lessons are written in Spanish. Lessons are entitled: (1) "La Migracion Mexicana Vista a Traves del Cuento 'Paso del Norte' de Juan Rulfo" (Jose Jorge Armendariz); (2) "Los Grupos Indigenas de…

  15. The Associate Program on Ethnobiology, Socio-Economic Value Assessment and Community Based Conservation

    DTIC Science & Technology

    2000-10-01

    lepidophyllus or wild fruits of Aframomum danielli; Annona gsenegalensis etc. Mushroom gathering was witnessed as a serious hobby and only three...Barks, fruits, seeds Ananas comosus Fruits, stems, leaves Annona muricata Seeds, leaves Arbrusprecatorious Leaves, seeds, roots Argemone mexicana Leaves

  16. Agricultural Policy and Child Health in Rural Mexico.

    ERIC Educational Resources Information Center

    Brown, Antoinette B.; Partridge, William L.

    1987-01-01

    Reports on the impact on malnutrition of Mexico's Sistema de Alementacion Mexicana (SAM) program, which tried to make the country self-sufficient in basic foods. Concludes that the food problem in Mexico is not so much one of production as it is a problem of distribution and consumption. (PS)

  17. Host instar susceptibility and selection and interspecific competition of three introduced parasitoids of the mealybug Paracoccus marginatus (Hemiptera: Pseudococcidae).

    PubMed

    Amarasekare, Kaushalya G; Mannion, Catharine M; Epsky, Nancy D

    2010-10-01

    Three previously introduced parasitoids (Acerophagus papayae Noyes and Schauff, Anagyrus loecki Noyes and Menezes, and Pseudleptomastix mexicana Noyes and Schauff [Hymenoptera: Encyrtidae]) of the mealybug Paracoccus marginatus Williams and Granara de Willink (Hemiptera: Pseudococcidae) were studied for their host instar susceptibility and sex ratio, host instar selection, and interspecific competition in the laboratory. All three parasitoids were able to develop in the second instars, third-instar females, and adult females of P. marginatus. No progeny emerged from first-instar mealybugs. The proportion of female emergence was increased with increasing host size. Parasitoids selected their host instars for oviposition when they had a choice. Between second- and third-instar hosts, A. papayae and P. mexicana had significantly higher parasitism in second-instar mealybugs, whereas A. loecki had higher parasitism in the third-instar mealybugs. When competed with either one or two parasitoid species, A. papayae was significantly more successful in second-instar hosts and A. loecki was significantly more successful in third-instar mealybugs. P. mexicana was significantly less competitive when with A. papayae in both second and third instars, with A. loecki in third instars and with both A. papayae and A. loecki in second and third instars. Overall, A. papayae provided a better control of the host, when present singly or with the other two parasitoids. This information is important in evaluating the efficiency of A. papayae, A. loecki, and P. mexicana and understanding the outcome of their recovery and establishment in field studies conducted in Florida.

  18. Even beyond the Local Community: A Close Look at Latina Youths' Return Trips to Mexico

    ERIC Educational Resources Information Center

    Sanchez, Patricia

    2009-01-01

    Drawing from nearly four years of qualitative research, this article examines the lives of three second-generation mexicanas living in northern California who maintain close ties to their families' natal communities in Mexico. This ethnographic portrait outlines the contours of belonging in these spaces, including the affection and close…

  19. Strategic Target Systems (STARS) Environmental Assessment. Supplement

    DTIC Science & Technology

    1991-07-01

    guarantee it will go where you want it? Response: We track it by radar, observe it by television , and track by telemetry from the missile. If the missile...moorhen (Gallinula chloropus sandvicensis), the black-necked (Hawaiian) stilt (Himantopus mexicanas knudseni), and the Hawaiian duck (Anas uyvilliana

  20. Multicultural Leader Behaviors in Ethnically Mixed Task Groups.

    DTIC Science & Technology

    1980-03-15

    Deficit, difference, and bicultural models of Afro-American behavior. Harvard Educational Review, 1971, 41, (2), 137-157. Vasconcellos, J. La raza ...cosmica (4th ed.). Mexico, D.F.: Espasa-Calpe Mexicana, S. A., 1976. Zea, L. Dependencia y liberacion en la cultura latinoamericana. Mexico, D.F

  1. Sheep symposium: Biology and management of low-input lambing in easy-care systems

    USDA-ARS?s Scientific Manuscript database

    Low-input lambing management was the focus of the 2007 Sheep Symposium at the joint annual meetings of the American Society of Animal Science, the American Dairy Science Association, the Asociacio´n Mexicana de Produccio´n Animal, and the Poultry Science Association held in San Antonio, Texas, on Ju...

  2. Ionized Gaseous Nebulae

    NASA Astrophysics Data System (ADS)

    Franco, José; Henney, William; Martos, Marco; Peña, Miriam

    2001-06-01

    Conference was held in Mexico City on 2000 November 21-24. Proceedings will be edited by José Franco, William Henney, Marco Martos, and Miriam Peña and will be published in Revista Mexicana de Astronomía y Astrofísica (Serie de Conferencias).

  3. Genetic identification of a novel hantavirus of the harvest mouse Reithrodontomys megalotis.

    PubMed Central

    Hjelle, B; Chavez-Giles, F; Torrez-Martinez, N; Yates, T; Sarisky, J; Webb, J; Ascher, M

    1994-01-01

    We have cloned the S genomic segment of a novel hantavirus of the harvest mouse Reithrodontomys megalotis. The virus is phylogenetically distinct from other hantaviruses. The new hantavirus was identified in harvest mice separated by approximately 1,000 km. A wood rat (Neotoma mexicana) was found to be infected with the harvest mouse hantavirus. PMID:8084007

  4. Bibliography of Writings on La Mujer.

    ERIC Educational Resources Information Center

    Portillo, Cristina, Comp.; And Others

    The 283 materials cited in this bibliography are chiefly on Chicanas in the United States. However, books or articles that discuss Mexicanas or women in general and can be related to the experiences of Chicanas are also cited. Areas covered include the arts, education, sociology, economics, history, health, and literature. The materials are…

  5. Nest densities of cavity-nesting birds in relation to postfire salvage logging and time since wildfire

    Treesearch

    Victoria A. Saab; Robin E. Russell; Jonathan G. Dudley

    2007-01-01

    We monitored the nest densities and nest survival of seven cavity-nesting bird species, including four open-space foragers (American Kestrel [Falco sparverius], Lewis's Woodpecker [Melanerpes lewis], Western Bluebird [Sialia mexicana], and Mountain Bluebird [S. currucoides]) and three wood...

  6. The Geography Olympiad in Mexico

    ERIC Educational Resources Information Center

    Garcia-Garcia, Fernando

    2007-01-01

    The formal organisation of science Olympiads in Mexico dates from 1987, when a national contest on Mathematics was held in order to identify a team to represent the country in the International Mathematics Olympiad. In 1991, the Mexican Academy of Sciences ("Academia Mexicana de Ciencias"-AMC) created the National Science Olympiads…

  7. The College of Education Family Literacy Program: Exploring the Literacy Experiences of Latino Families

    ERIC Educational Resources Information Center

    Fessinger, Rosemary Kubiak

    2009-01-01

    This study presents the results of a fifteen-month research project conducted with a group of Latina (Mexicana) immigrant mothers who took part in an after-school family literacy program that was grounded in a participatory approach to education. This family literacy program emphasized a "strengths" perspective by acknowledging the rich resources…

  8. Aquatic Nuisance Sp[ecies Research Program. Ecological Impacts of Suckermouth Catfishes (Loricariidae) in North America: A Conceptual Model. Volume 14-1, March 2014

    DTIC Science & Technology

    2014-03-01

    cascudo Hypostomus commersonii Valeneciennes, 1840 (Osteichthys – Loricariidae) da represa Capivari-Cachoeira, Paraná, Brasil. Revista UNIMAR...Actinopterygii: Loricariidae) in the mouth of the Coahuayana River, Coahuayana, Michoacán, Mexico. Revista Mexicana de Biodiversidad 83: 294

  9. Identification of potential plant extracts for anti-tick activity against acaricide resistant cattle ticks, Rhipicephalus (Boophilus) microplus (Acari: Ixodidae).

    PubMed

    Ghosh, Srikanta; Tiwari, Shashi Shankar; Kumar, Bhanu; Srivastava, Sharad; Sharma, Anil Kumar; Kumar, Sachin; Bandyopadhyay, A; Julliet, Sanis; Kumar, Rajesh; Rawat, A K S

    2015-05-01

    To develop an eco-friendly tick control method, seven plant extracts were prepared using 50 and 95% ethanol and evaluated for acaricidal activity against cattle tick, Rhipicephalus (Boophilus) microplus. The adult immersion test was adopted for testing different extracts. Based on 72 h screening criterion, 95% ethanolic extracts of Datura metel fruits and Argemone mexicana whole plant were found effective showing more than 50% mortality of treated ticks. The 95% ethanolic extracts of D. metel fruits and A. mexicana whole plant exhibited acaricidal and reproductive inhibitory effects on treated ticks. The LC90 values of D. metel and A. mexicana extracts were determined as 7.13 and 11.3%, respectively. However, although both the extracts were found efficacious against deltamethrin-resistant IVRI-4 and multi-acaricide resistant IVRI-5 lines of R. (B.) microplus, they caused less mortality than treated ticks of the reference IVRI-I line. Phytochemical studies indicated the presence of alkaloids and glucosides in D. metel fruits and alkaloids, terpenoids, flavonoids and phenolics in A. mexicana whole plant extracts. The results indicated that these botanicals may play an important role in reducing the use of chemicals for tick control and possibly to manage resistant tick population in environment friendly manner.

  10. Opening the Mexican Door: Continental Defense Cooperation

    DTIC Science & Technology

    2005-09-01

    Mexicana de Acción Frente al Libre Comercio (RMALC) La Neta – Proyecto Emisiones: Espacio Virtual, Hazardous Waste Management in the United States...Frente al Libre Comercio (RMALC) La Neta – Proyecto Emisiones: Espacio Virtual. Hazardous Waste Management in the United States – Mexico Border States

  11. Genetic Diversity and Population Structure of Teosinte

    PubMed Central

    Fukunaga, Kenji; Hill, Jason; Vigouroux, Yves; Matsuoka, Yoshihiro; Sanchez G., Jesus; Liu, Kejun; Buckler, Edward S.; Doebley, John

    2005-01-01

    The teosintes, the closest wild relatives of maize, are important resources for the study of maize genetics and evolution and for plant breeding. We genotyped 237 individual teosinte plants for 93 microsatellites. Phylogenetic relationships among species and subspecific taxa were largely consistent with prior analyses for other types of molecular markers. Plants of all species formed monophyletic clades, although relationships among species were not fully resolved. Phylogenetic analysis indicated that the Mexican annual teosintes divide into two clusters that largely correspond to the previously defined subspecies, Z. mays ssp. parviglumis and ssp. mexicana, although there are a few samples that represent either evolutionary intermediates or hybrids between these two subspecies. The Mexican annual teosintes show genetic substructuring along geographic lines. Hybridization or introgression between some teosintes and maize occurs at a low level and appears most common with Z. mays ssp. mexicana. Phylogeographic and phylogenetic analyses of the Mexican annual teosintes indicated that ssp. parviglumis diversified in the eastern part of its distribution and spread from east to west and that ssp. mexicana diversified in the Central Plateau of Mexico and spread along multiple paths to the north and east. We defined core sets of collections of Z. mays ssp. mexicana and ssp. parviglumis that attempt to capture the maximum number of microsatellite alleles for given sample sizes. PMID:15687282

  12. Plastid DNA sequencing and nuclear SNP genotyping help resolve the puzzle of central American Platanus

    PubMed Central

    De Castro, Olga; Di Maio, Antonietta; Lozada García, José Armando; Piacenti, Danilo; Vázquez-Torres, Mario; De Luca, Paolo

    2013-01-01

    Background and Aims Recent research on the history of Platanus reveals that hybridization phenomena occurred in the central American species. This study has two goals: to help resolve the evolutive puzzle of central American Platanus, and to test the potential of real-time polymerase chain reaction (PCR) for detecting ancient hybridization. Methods Sequencing of a uniparental plastid DNA marker [psbA-trnH(GUG) intergenic spacer] and qualitative and quantitative single nucleotide polymorphism (SNP) genotyping of biparental nuclear ribosomal DNA (nrDNA) markers [LEAFY intron 2 (LFY-i2) and internal transcribed spacer 2 (ITS2)] were used. Key Results Based on the SNP genotyping results, several Platanus accessions show the presence of hybridization/introgression, including some accessions of P. rzedowskii and of P. mexicana var. interior and one of P. mexicana var. mexicana from Oaxaca (= P. oaxacana). Based on haplotype analyses of the psbA-trnH spacer, five haplotypes were detected. The most common of these is present in taxa belonging to P. orientalis, P. racemosa sensu lato, some accessions of P. occidentalis sensu stricto (s.s.) from Texas, P. occidentalis var. palmeri, P. mexicana s.s. and P. rzedowskii. This is highly relevant to genetic relationships with the haplotypes present in P. occidentalis s.s. and P. mexicana var. interior. Conclusions Hybridization and introgression events between lineages ancestral to modern central and eastern North American Platanus species occurred. Plastid haplotypes and qualitative and quantitative SNP genotyping provide information critical for understanding the complex history of Mexican Platanus. Compared with the usual molecular techniques of sub-cloning, sequencing and genotyping, real-time PCR assay is a quick and sensitive technique for analysing complex evolutionary patterns. PMID:23798602

  13. [Geographic distribution of Leishmania species isolated from patients at the National Institute of Dermatology Federico Lleras Acosta E.S.E., 1995-2005].

    PubMed

    Ovalle, Clemencia Elena; Porras, Luisa; Rey, Maritza; Ríos, Melania; Camargo, Yenny Carolina

    2006-10-01

    The Colombian distribution map of Leishmania species has not been updated since seven years ago. To describe the distribution of Leishmania species isolated from patients attended at the National Institute of Dermatology during the period 1995 to 2005. A descriptive study of the geographic distribution of Leishmania species was made from 137 isolates obtained from patients consulting the National Institute of Dermatology "Federico Lleras Acosta E.S.E", with confirmed diagnosis of leishmaniasis. The clinical history was reviewed to obtain information on the clinical presentation, most probable place of infection, age and gender. Samples were taken and cultured and the isolates were typed by monoclonal antibodies, comparing 10% of the results with those obtained by PCR and isoenzymatic patterns. L. panamensis accounted for 74.45% of the 137 isolates studied, L. braziliensis for 15.33%, L. guyanensis for 0.73%; L. mexicana complex for 3.65%, L. mexicana 5.11% and the remaining 0.73% corresponded to an isolate which could not be characterized by monoclonal antibodies. The distribution of L. braziliensis, L. panamensis and L. guyanensis was similar to that reported in previous studies but species of the L. mexicana complex, were found in patients from the departments of Caldas, Santander, Cundinamarca, Caquetá, Casanare, Cauca and Valle del Cauca, where they had not been previously reported. Species of the L. mexicana complex display a wider distribution than previously reported. The usefulness of species-specific monoclonal antibodies, isoenzymatic patterns, and PCR for identification of L. mexicana and L. amazonensis was limited.

  14. A case report and literature review of "Chiclero's ulcer".

    PubMed

    Blaylock, Jason M; Wortmann, Glenn W

    2012-09-01

    An 86-year-old man with history of travel to Guatemala presented with a 4-month history of an enlarging ulcerative lesion on his right ear. After several weeks of empiric treatment for otitis externa, histopathology, culture, and PCR analysis of a biopsy specimen confirmed the diagnosis of localized cutaneous leishmaniasis secondary to Leishmania mexicana. Known as "Chiclero's ulcer" in southeast Mexico and Latin America, this unique presentation of cutaneous leishmaniasis is caused mainly by the L. mexicana complex. Infection results in a single ulcerative lesion, most commonly involving the ear pinna, without a tendency for cutaneous metastasis, lymphatic or mucosal involvement. The majority of cases of "Chiclero's ulcer" spontaneously re-epithelialize without treatment within 3-9 months. This patient's lesion completely resolved without therapy after 11 months. "Chiclero's ulcer" should be considered in the differential diagnosis of a patient presenting with a chronic ulcerative lesion and history of travel to an endemic area.

  15. Geographic Distribution of Leishmania Species in Ecuador Based on the Cytochrome B Gene Sequence Analysis.

    PubMed

    Kato, Hirotomo; Gomez, Eduardo A; Martini-Robles, Luiggi; Muzzio, Jenny; Velez, Lenin; Calvopiña, Manuel; Romero-Alvarez, Daniel; Mimori, Tatsuyuki; Uezato, Hiroshi; Hashiguchi, Yoshihisa

    2016-07-01

    A countrywide epidemiological study was performed to elucidate the current geographic distribution of causative species of cutaneous leishmaniasis (CL) in Ecuador by using FTA card-spotted samples and smear slides as DNA sources. Putative Leishmania in 165 samples collected from patients with CL in 16 provinces of Ecuador were examined at the species level based on the cytochrome b gene sequence analysis. Of these, 125 samples were successfully identified as Leishmania (Viannia) guyanensis, L. (V.) braziliensis, L. (V.) naiffi, L. (V.) lainsoni, and L. (Leishmania) mexicana. Two dominant species, L. (V.) guyanensis and L. (V.) braziliensis, were widely distributed in Pacific coast subtropical and Amazonian tropical areas, respectively. Recently reported L. (V.) naiffi and L. (V.) lainsoni were identified in Amazonian areas, and L. (L.) mexicana was identified in an Andean highland area. Importantly, the present study demonstrated that cases of L. (V.) braziliensis infection are increasing in Pacific coast areas.

  16. Geographic Distribution of Leishmania Species in Ecuador Based on the Cytochrome B Gene Sequence Analysis

    PubMed Central

    Kato, Hirotomo; Gomez, Eduardo A.; Martini-Robles, Luiggi; Muzzio, Jenny; Velez, Lenin; Calvopiña, Manuel; Romero-Alvarez, Daniel; Mimori, Tatsuyuki; Uezato, Hiroshi; Hashiguchi, Yoshihisa

    2016-01-01

    A countrywide epidemiological study was performed to elucidate the current geographic distribution of causative species of cutaneous leishmaniasis (CL) in Ecuador by using FTA card-spotted samples and smear slides as DNA sources. Putative Leishmania in 165 samples collected from patients with CL in 16 provinces of Ecuador were examined at the species level based on the cytochrome b gene sequence analysis. Of these, 125 samples were successfully identified as Leishmania (Viannia) guyanensis, L. (V.) braziliensis, L. (V.) naiffi, L. (V.) lainsoni, and L. (Leishmania) mexicana. Two dominant species, L. (V.) guyanensis and L. (V.) braziliensis, were widely distributed in Pacific coast subtropical and Amazonian tropical areas, respectively. Recently reported L. (V.) naiffi and L. (V.) lainsoni were identified in Amazonian areas, and L. (L.) mexicana was identified in an Andean highland area. Importantly, the present study demonstrated that cases of L. (V.) braziliensis infection are increasing in Pacific coast areas. PMID:27410039

  17. Leishmaniasis entomological field studies: ethical issues.

    PubMed

    Andrade-Narvaez, Fernando; Canto-Lara, Silvia B; Del Rosario Garcia-Miss, Maria

    2009-12-01

    Occupational health remains neglected in developing countries because of competing social, economic and political challenges. Ethical issues in the workplace related to the hazards and risks of becoming infected by Leishmania (Leishmania) mexicana, through the bite of naturally infected sand flies, is another area of concern that has been neglected as well. We report here the results of reviewing two entomological field studies carried out in our research center from 2003 to 2006. Eight students from our School of Biology were invited to catch sand flies. A total of six of the eight (75%) developed a typical clinical picture of Localized Cutaneous Leishmaniasis (LCL) caused by L. (L.) mexicana. In this article we identify the ethical issues related to these kinds of studies and propose some guidelines for conducting them.

  18. Coastal habitat degradation and green sea turtle diets in Southeastern Brazil

    USGS Publications Warehouse

    Santos, Robson G.; Martins, Agnaldo Silva; Farias, Julyana da Nobrega; Horta, Antunes Paulo; Pinheiro, Hudson Tercio; Baptistotte, Cecilia; Seminoff, Jeffrey A.; Balazs, George H.; Work, Thierry M.

    2011-01-01

    To show the influence of coastal habitat degradation on the availability of food for green turtles (Chelonia mydas), we assessed the dietary preferences and macroalgae community at a feeding area in a highly urbanized region. The area showed low species richness and was classified as degraded. We examined stomach contents of 15 dead stranded turtles (CCL = 44.0 cm (SD 6.7 cm)). The diet was composed primarily of green algae Ulva spp. (83.6%). In contrast, the macroalgae community was dominated by the green alga Caulerpa mexicana. We found a selection for red algae, seagrass and Ulva spp., and avoidance for C. mexicana and brown alga Dictyopteris delicatula. The low diversity of available food items, possibly a result of environmental degradation, likely contributed to the low dietary diversity. The nutritional implications of this restricted diet are unclear.

  19. Coastal habitat degradation and green sea turtle diets in Southeastern Brazil.

    PubMed

    Santos, Robson G; Martins, Agnaldo Silva; Farias, Julyana da Nobrega; Horta, Paulo Antunes; Pinheiro, Hudson Tercio; Torezani, Evelise; Baptistotte, Cecília; Seminoff, Jeffrey A; Balazs, George H; Work, Thierry M

    2011-06-01

    To show the influence of coastal habitat degradation on the availability of food for green turtles (Chelonia mydas), we assessed the dietary preferences and macroalgae community at a feeding area in a highly urbanized region. The area showed low species richness and was classified as degraded. We examined stomach contents of 15 dead stranded turtles (CCL=44.0cm (SD 6.7cm)). The diet was composed primarily of green algae Ulva spp. (83.6%). In contrast, the macroalgae community was dominated by the green alga Caulerpa mexicana. We found a selection for red algae, seagrass and Ulva spp., and avoidance for C. mexicana and brown alga Dictyopteris delicatula. The low diversity of available food items, possibly a result of environmental degradation, likely contributed to the low dietary diversity. The nutritional implications of this restricted diet are unclear. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Male mate choice and sperm allocation in a sexual/asexual mating complex of Poecilia (Poeciliidae, Teleostei)

    PubMed Central

    Schlupp, I; Plath, M

    2005-01-01

    Male mate choice is critical for understanding the evolution and maintenance of sexual/asexual mating complexes involving sperm-dependent, gynogenetic species. Amazon mollies (Poecilia formosa) require sperm to trigger embryogenesis, but the males (e.g. Poecilia mexicana) do not contribute genes. Males benefit from mating with Amazon mollies, because such matings make males more attractive to conspecific females, but they might control the cost of such matings by providing less sperm to Amazon mollies. We examined this at the behavioural and sperm levels. P. mexicana males preferred to mate with, and transferred more sperm to conspecific females. However, if males mated with P. formosa, sperm was readily transferred. This underscores the importance of male choice in this system. PMID:17148157

  1. Coastal habitat degradation and green sea turtle diets in Southeastern Brazil.

    USGS Publications Warehouse

    Santos, Robson G.; Martins, Agnaldo Silva; Farias, Julyana da Nobrega; Horta, Antunes Paulo; Pinheiro, Hudson Tercio; Baptistotte, Cecilia; Seminoff, Jeffrey A.; Balazs, George H.; Work, Thierry M.

    2011-01-01

    To show the influence of coastal habitat degradation on the availability of food for green turtles (Chelonia mydas), we assessed the dietary preferences and macroalgae community at a feeding area in a highly urbanized region. The area showed low species richness and was classified as degraded. We examined stomach contents of 15 dead stranded turtles (CCL = 44.0 cm (SD 6.7 cm)). The diet was composed primarily of green algae Ulva spp. (83.6%). In contrast, the macroalgae community was dominated by the green alga Caulerpa mexicana. We found a selection for red algae, seagrass and Ulva spp., and avoidance for C. mexicana and brown alga Dictyopteris delicatula. The low diversity of available food items, possibly a result of environmental degradation, likely contributed to the low dietary diversity. The nutritional implications of this restricted diet are unclear.

  2. Male-biased predation of a cave fish by a giant water bug

    NASA Astrophysics Data System (ADS)

    Tobler, Michael; Franssen, Courtney M.; Plath, Martin

    2008-08-01

    Male-biased predation has been described from several epigean species, and in many cases, intrinsic differences between the sexes (such as male ornaments) have been suggested as an explanation. Here we report on male-biased predation of a cave fish ( Poecilia mexicana) by an aquatic insect ( Belostoma sp.) in a Mexican sulfur cave. P. mexicana use aquatic surface respiration (ASR) to survive in their sulfidic, hypoxic habitat. We found that males typically exhibit more ASR activity than females, which leads to increased exposure to the sit-and-wait predator that catches fish near the water surface. Our finding is novel, because male vulnerability to predation is not directly related to male traits involved in courtship, but rather due to other sexual differences in behavior and ultimately, oxygen demands.

  3. Anti Leishmanial Effect of Zinc Sulphate on the Viability of Leishmania tropica and L. major Promastigotes

    PubMed Central

    Fattahi Bafghi, Ali; Noorbala, Mohammad; Noorbala, Mohammad Taghi; Aghabagheri, Mahdi

    2014-01-01

    Background: Cutaneous leishmaniasis (CL) is an endemic disease in developing countries. Although pentamidine orantimonite (Glucantime) has been recommended for cutaneous leishmaniasis treatment by the World Health Organization, there are some concerns too such as high cost, side effects, need for frequent injections, and restricted efficacy. Therefore, different methods have been used for CL treatment so far. Objectives: This study assessed the sensitivity of two parasite agents of cutaneous leishmaniasis: Leishmania major and L. tropica to zinc sulphate in vitro. In the present study, the zinc sulphate effect on urban and rural strains of cutaneous leishmaniasis, viability of old world, in vitro is under investigation. Materials and Methods: The design of the present study was experimental (laboratory-trial) based. Iranian endemic species of L. major and L. tropica were appropriately collected, proliferated, and maintained in the standard culture. Afterward, the proper concentrations of zinc sulphate were provided, sterilized, and added to the cultures containing parasites. In different intervals, parasites were counted by two methods: the slide and cell proliferation ELISA. Results: Both parasite species showed sensitivity to zinc sulphate in vitro and in comparison with the control group, their numbers were reduced. Zinc sulphate (in concentrations of 0.5, 1, 2, and 3 percent) was added to the cultures containing parasites, and the total number of the live parasites was counted through the slide method (Neubauer slide) every day up to the fifth day. The results were analyzed and found statistically significant (P < 0.05). In the second phase, the counting process was repeated with the addition of zinc sulphate compound with different concentrations (3, 4, 5, and 6 percent) and live parasite numbers were counted by ELISA method after 24 hours. The findings revealed that all the cultures containing zinc sulphate showed a slower growth in comparison to the control group. The mentioned difference was statistically significant (P < 0.05). Conclusions: Considering the safety of zinc sulphate compound in comparison with Glucantime, there is a possibility of using it in the treatment of CL caused by both species of L. major and L. tropica. It is obvious that more researches are mandatory both in vivo and in vitro to figure out its daily dosage, proper concentration, time and duration, and possible side effects. PMID:25485055

  4. Anti Leishmanial Effect of Zinc Sulphate on the Viability of Leishmania tropica and L. major Promastigotes.

    PubMed

    Fattahi Bafghi, Ali; Noorbala, Mohammad; Noorbala, Mohammad Taghi; Aghabagheri, Mahdi

    2014-09-01

    Cutaneous leishmaniasis (CL) is an endemic disease in developing countries. Although pentamidine orantimonite (Glucantime) has been recommended for cutaneous leishmaniasis treatment by the World Health Organization, there are some concerns too such as high cost, side effects, need for frequent injections, and restricted efficacy. Therefore, different methods have been used for CL treatment so far. This study assessed the sensitivity of two parasite agents of cutaneous leishmaniasis: Leishmania major and L. tropica to zinc sulphate in vitro. In the present study, the zinc sulphate effect on urban and rural strains of cutaneous leishmaniasis, viability of old world, in vitro is under investigation. The design of the present study was experimental (laboratory-trial) based. Iranian endemic species of L. major and L. tropica were appropriately collected, proliferated, and maintained in the standard culture. Afterward, the proper concentrations of zinc sulphate were provided, sterilized, and added to the cultures containing parasites. In different intervals, parasites were counted by two methods: the slide and cell proliferation ELISA. Both parasite species showed sensitivity to zinc sulphate in vitro and in comparison with the control group, their numbers were reduced. Zinc sulphate (in concentrations of 0.5, 1, 2, and 3 percent) was added to the cultures containing parasites, and the total number of the live parasites was counted through the slide method (Neubauer slide) every day up to the fifth day. The results were analyzed and found statistically significant (P < 0.05). In the second phase, the counting process was repeated with the addition of zinc sulphate compound with different concentrations (3, 4, 5, and 6 percent) and live parasite numbers were counted by ELISA method after 24 hours. The findings revealed that all the cultures containing zinc sulphate showed a slower growth in comparison to the control group. The mentioned difference was statistically significant (P < 0.05). Considering the safety of zinc sulphate compound in comparison with Glucantime, there is a possibility of using it in the treatment of CL caused by both species of L. major and L. tropica. It is obvious that more researches are mandatory both in vivo and in vitro to figure out its daily dosage, proper concentration, time and duration, and possible side effects.

  5. Pi inhibits intracellular accumulation of methylglyoxal in promastigote form of L. donovani.

    PubMed

    Tiwari, Praachi; Verma, Pankaj; Kureel, Amit Kumar; Saini, Sheetal; Rai, Ambak Kumar

    2016-06-01

    Similar to their mammalian counterpart, protozoan parasites including Leishmania donovani detoxify methylglyoxal (MG),(1) a toxic ubiquitous product generated in glycolysis pathway. However, it differs in one or more way(s) from the humans. It is known that MG is eliminated either through glyoxalase (GLO)(2) pathway and/or excreted across the cell membrane. This toxic metabolic by-product is known to be detoxified predominantly by the GLO pathway and excretion across the cell membrane is never considered to be a significant pathway for its detoxification. We have tried to modulate these pathways under various physiological conditions to find ways that may lead to accumulation of MG in L. donovani. Besides targeting the GLO pathway, we intend to understand the mechanism of MG release across the cell membrane and possible ways to inhibit its exclusion from parasites. In our study, it was found that inorganic phosphate (Pi)(3) in the presence of glucose inhibits the production of MG as well as promotes the expulsion of MG from the cell. Moreover, the trivalent form of antimony (Sb(III)) inhibits GLO pathway and thus detoxification of MG. Inhibition of Pi transport, which is a Na(+)/H(+) dependent process, restores the Pi mediated abrogation of MG production. Thus, Sb(III) along with inhibitors of Pi transporter may be a therapeutic advancement for treatment of antimony resistant cases of human visceral leishmaniasis. However, it requires further validation using specific inhibitor(s) of Pi transporter. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. The hyphomycete genus Piricauda, with the description of a new species.

    PubMed

    Mercado Sierra, Angel; Guarro, Josep; Heredia, Gabriela

    2005-06-01

    The genus Piricauda comprises eight species characterized by monotretic conidiogenous cells and micronematous arched conidiophores: P. cochinensis, P. cubensis, P. longispora, P. mexicana, P. paraguayensis, P. pseudarthriae, P. taiwanensis, and P. vulcanensis sp. nov. P. caribensis is transferred to Acrodictys. Species usually colonize dead petioles and rachides of palms in tropical and subtropical areas, but can also be found on branches and leaves of different trees. The species are illustrated and briefly described, and a key to them is provided.

  7. Isoenzyme characterization of Leishmania isolated from human cases with localized cutaneous leishmaniasis from the State of Campeche, Yucatan Peninsula, Mexico.

    PubMed

    Canto-Lara, S B; Cardenas-Maruffo, M F; Vargas-Gonzalez, A; Andrade-Narvaez, F

    1998-04-01

    Seventy-five isolates from the State of Campeche, Mexico, an area endemic for localized cutaneous leishmaniasis (LCL), were characterized by isoenzyme markers (glucose phosphate isomerase, mannose phospate isomerase, nucleoside hydrolase, phosphoglucomutase, 6-phosphogluconate dehydrogenase, and glucose-6-phosphate dehydrogenase). Seventy (93.3%) were identified as Leishmania (Leishmania) mexicana and 5 (6.7%) as L. (Viannia) braziliensis. This is the first report of authochthonus human LCL caused by L. (V.) braziliensis in the State of Campeche, Yucatan Peninsula, Mexico.

  8. Earthquake Response of Concrete Gravity Dams Including Hydrodynamic and Foundation Interaction Effects,

    DTIC Science & Technology

    1980-01-01

    Presas y Depositos", Boletin Sociedad Mexicana de Ingenieria Sismica, Vol. 1, No. 2, October 1963. 10. A. K. Chopra,"Hydrodynamic Pressures on Dams...Veracruz, Mexico , 1968. 12. A. Flores, I. Herrera and C. Lozano, "Hydrodynamic Pressure Generated by Vertical Earthquake Component", Proceedings, Fourth...transform of the ground motion and Nthe inverse transforms of the re- sponses are obtained at the first -T points spaced at equal intervals of time At

  9. The Zapatista Social Netwar in Mexico

    DTIC Science & Technology

    1998-01-01

    on the Internet. 4From a statement by Subcommandante Marcos, March 4, 1994, as reported by the Academia Mexicana de Derechos Humanos, Special...darker purposes might include strategic crime and criminal mercantilism ?17 Mexico faces a continuing challenge of coping with all manner of netwars...ings). Mexico is characterized by criminal mercantilism , and possibly strategic crime against the United States. Reports about Mexican crime

  10. Cutaneous Leishmaniasis

    DTIC Science & Technology

    2011-06-01

    is common. No oral agents can be generally recommended for the treatment of any of the cutaneous syndromes. Antifungal agents such as ketoconazole ...the New World and the Old World. Itraconazole and fluconazole are only slightly more effective than placebo. Ketoconazole is modestly effective...against L. major, L. panamensis, and L. mexicana, but ineffective against L. tropica and L. brazil- iensis. In Guatemala, ketoconazole has proven

  11. Testing Experimental Compounds against American Cutaneous and Mucocutaneous Leishmaniasis.

    DTIC Science & Technology

    1982-07-01

    Report) 1S. SUPPLEMENTARY NOTES * I9. KEY WORDS (Continue on reverse aide it necessary end identify by block number) * Leishmania braziliensis panamensis...eight WRAIR compounds have been tested against two subspecies of L. mexicana, three species of Leishmania braziliensis, and L. donovani. Five of these...ketoconazole and its acid hydrolysate are active against Trypanosoma and Leishmania species in vitro. Neither of these compounds was active against L

  12. Chlamydomonas sajao nov. sp. (Chlorophyta, Volvocales)

    NASA Astrophysics Data System (ADS)

    Lewin, Ralph A.

    1984-06-01

    A new species of Chlamydomonas, namely, C. sajao nov. sp. of the Volvocales, Chlorophyta was isolated from a duckweed growing near a ricefield in the vicinity of Guangzhou, China. This interesting unicellular green alga, similar to C. mexicana from Mexico, secretes quantities of extracellular mucilaginous polysaccharides, and may be employed in improving soil quality. The new species resembles C. waldenburgensis Moewus in most characteristics but differs in three important features.

  13. Ultrastructural Study on Tissue Alterations Caused by Trypanosomatids in Experimental Murine Infections

    PubMed Central

    Finol, Héctor J.; Roschman-González, Antonio

    2014-01-01

    The ultrastructural study in different tissues of mice experimentally infected with isolates of Trypanosoma evansi, Trypanosoma cruzi, and Leishmania mexicana reveals changes in cardiac myocytes, skeletal muscle fibers, and hepatic, adrenal, kidney, and spleen cells. Some of these changes were cytoarchitectural and others consisted of necrosis. Alterations in the microvasculature were also found. The mononuclear cell infiltrate included neutrophils, eosinophils, and macrophages. This work shows that diverse mice tissues are important target for trypanosomatids. PMID:25072046

  14. Human Trafficking and the Impact on National Security for the United States

    DTIC Science & Technology

    2006-03-15

    Transportacion Ferroviaria Mexicana. These elements could provide any needed support to potential terrorists traveling via rail); and 2) The Mara Salvatrucha...to use the trains as a way of entering the United States must do business with the Mara Salvatrucha.23 5 Factors Promoting Sex Tourism Governments and...promote sex tourism : • Men’s demand for the sex of prostitution • Increasing poverty, driving women and children into situations of sexual

  15. Cutaneous leishmaniasis in North Dakota.

    PubMed

    Douvoyiannis, Miltiadis; Khromachou, Tamim; Byers, Norman; Hargreaves, James; Murray, Henry W

    2014-09-01

    In the United States, autochthonous cutaneous leishmaniasis caused by infection with Leishmania mexicana has been reported from Texas and Oklahoma. Here, we describe a child with 2 new features: cutaneous infection acquired outside of the south-central United States (in North Dakota) and infection caused by Leishmania donovani species complex. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  16. Development of Serologic Assays for the Diagnosis of New World Leishmaniasis

    DTIC Science & Technology

    1986-02-20

    Memorial Laboratory (GML), were . importance in deciding regimens of treatment, 10 mM Hepes, 20% fetal calf serum and anti- - management of the patient and... management of patients. While most skin lesions caused by species of the mexicana complex are relatively mild and heal spontan- eously, infection with L... hybric cell lines, Selected Methods in Cellular Immunology, Edited by BB Mishell, SM Shiigi, San Francisco, WH Freeman, 1980, pp 351-372 16 -16- - L 16

  17. Manufacturing: A Report on the Industry 2004

    DTIC Science & Technology

    2004-06-01

    to Sustaining the Productivity Boom,” White paper from National Coalition for Advanced Manufacturing, May 30, 2003. Instituto Nacional de... Empleo ”. Universidad Autónoma de México, 1994 Maskell, Brian, “The Age of Agile Manufacturing”, Supply Chain Management, Vol 6, Issue 1, 2001. From...en la manufactura Mexicana: La dinámica Tecnológica de los Sectores de Mayor Competitividad” Universidad Nacional Autónoma del Estado de Hidalgo

  18. Whither Elite Cohesion in Mexico: A Comment

    DTIC Science & Technology

    1988-11-01

    into formal structures, like the Ministry of Interior, the PRI, and the labor sector. We may then talk as though political consenisus and conflict...occur in terms of such formal structures. Yet we know full well that what happens in Mexican politics often depends on underlying, informal, fluid...Generacicnes: Los Protagonistas de Ia Reforma y la Revoluci(n Mexicana, Secretaria de Educacion Pblica, Consejo Nacional de Fomento Educat ivo, Mexico City

  19. The Identification of Anopheles (Nyssorhynchus) rondoni (Diptera: Culicidae) in Mato Grosso State, Brazil: An Analysis of Key Character Variability

    DTIC Science & Technology

    1995-10-01

    Smithsonian Institution (NMNH specimens). They are from Corrientes and Jujuy Provinces, Argentina and, S%o Paulo State and Costa Marques...fre- circles are specimens primarily f.+om northern Argentina , in text quencies of missing wing spots among female referred to as NMNH specimens...Hoffmann CC 1938. La formacibn de razas en 10s Anopheles mexicanos. II. Anopheles albimanus y sus variedades en la Republica Mexicana. An Inst

  20. New species of Cerambycinae from the Neotropical Region, and nomen novum for Anelaphus maculatus Galileo, Martins, and Santos-Silva, 2014 (Elaphidiini).

    PubMed

    Galileo, Maria Helena M; Martins, Ubirajara R; Santos-Silva, Antonio

    2015-07-17

    Six new species and one new genus are described: Criodion spinosum sp. nov. (Cerambycini), from Bolivia; Eburodacrys wappesi sp. nov. and Eburodacrys skillmani sp. nov. (Eburiini), from Bolivia; Eupempelus rileyorum sp. nov. (Heteropsini) from Panama; Sphalloeme mexicana sp. nov. (Oemini), from Mexico; Wappesoeme camiri sp. nov., new genus (Oemini), from Bolivia. Wappesoeme, Eburodacrys wappesi, E. skillmani, Eupempelus rileyorum, and Criodion spinosum are included in previously published keys. Anelaphus erakyra nomen novum for A. maculatus Galileo et al., 2014 is established.

  1. Mexican Buprestidae: two new species of Acmaeodera Eschscholtz and a review of the genus Chalcophora Dejean.

    PubMed

    Westcott, Richard L; Bellamy, Charles L

    2013-01-01

    Two distinctive new Mexican species of Acmaeodera Eschscholtz are described, A. xanthoskeles from the Yucatán Peninsula and A. inusitata from Michoacán. The Mexican species of the genus Chalcophora Dejean, C. hondurasica Casey and C. mexicana Waterhouse, are reviewed and discussed along with two U.S. and Canadian species, C. angulicollis (LeConte) and C. virginiensis (Drury). Chalcophora angulicollis is shown not to occur in Texas as has long been recorded.

  2. Inner Ear Morphology in the Atlantic Molly Poecilia mexicana—First Detailed Microanatomical Study of the Inner Ear of a Cyprinodontiform Species

    PubMed Central

    Schulz-Mirbach, Tanja; Heß, Martin; Plath, Martin

    2011-01-01

    Background Fishes show an amazing diversity in hearing abilities, inner ear structures, and otolith morphology. Inner ear morphology, however, has not yet been investigated in detail in any member of the diverse order Cyprinodontiformes. We, therefore, studied the inner ear of the cyprinodontiform freshwater fish Poecilia mexicana by analyzing the position of otoliths in situ, investigating the 3D structure of sensory epithelia, and examining the orientation patterns of ciliary bundles of the sensory hair cells, while combining μ-CT analyses, scanning electron microscopy, and immunocytochemical methods. P. mexicana occurs in different ecotypes, enabling us to study the intra-specific variability (on a qualitative basis) of fish from regular surface streams, and the Cueva del Azufre, a sulfidic cave in southern Mexico. Results The inner ear of Poecilia mexicana displays a combination of several remarkable features. The utricle is connected rostrally instead of dorso-rostrally to the saccule, and the macula sacculi, therefore, is very close to the utricle. Moreover, the macula sacculi possesses dorsal and ventral bulges. The two studied ecotypes of P. mexicana showed variation mainly in the shape and curvature of the macula lagenae, in the curvature of the macula sacculi, and in the thickness of the otolithic membrane. Conclusions Our study for the first time provides detailed insights into the auditory periphery of a cyprinodontiform inner ear and thus serves a basis—especially with regard to the application of 3D techniques—for further research on structure-function relationships of inner ears within the species-rich order Cyprinodontiformes. We suggest that other poeciliid taxa, or even other non-poeciliid cyprinodontiforms, may display similar inner ear morphologies as described here. PMID:22110746

  3. In Vitro Antifungal Susceptibilities of Five Species of Sporothrix▿

    PubMed Central

    Marimon, Rita; Serena, Carolina; Gené, Josepa; Cano, Josep; Guarro, Josep

    2008-01-01

    Ninety-two isolates belonging to five species of the Sporothrix schenckii complex were tested in vitro against 12 antifungal agents, using a reference microdilution method. There were significant differences among the species; Sporothrix brasiliensis was the species that showed the best response to antifungals, and S. mexicana had the worst response. In general, terbinafine was the most active drug, followed by ketoconazole and posaconazole. PMID:18039919

  4. What is a chromosome like in Leishmania?

    PubMed

    Galindo, I; Arguello, C; Ramirez, J L

    1993-01-01

    Hereby, we present evidences of the presence of centromeric proteins in Leishmania mexicana. These proteins were partially purified and used to bind Leishmania DNA. The protein-DNA complex was immunoprecipitated and the DNA extracted, like in the human sample. Two major fragments of 1.2 and 2.2 Kbp, respectively, were resolved in agarose gel electrophoresis. A model of chromosomal structure and chromosomal segregation in Leishmania is presented.

  5. Taxonomic revision of wasp-like richardiids, Neoidiotypa Osten-Sacken (Diptera, Tephritoidea, Richardiidae).

    PubMed

    Wendt, Lisiane Dilli; Ale-Rocha, Rosaly

    2014-09-01

    Previously Neoidiotypa was a monotypic genus represented by a peculiar wasp-like richardiid from Cuba - N. appendiculata (Loew). In this work, five new species are described in this genus: N. mexicana sp. nov. from Mexico; N. alamagna sp. nov., N. flaviatra sp. nov., N. nigra sp. nov. and N. sticta sp. nov. from Costa Rica. New diagnostic characters for the genus are included. An identification key and illustrations for all species are provided. 

  6. The Evolution of the Mexican Military: From the Mexican Revolution In 1910 to 2014

    DTIC Science & Technology

    2015-03-01

    ix THIS PAGE INTENTIONALLY LEFT BLANK x LIST OF ACRONYMS AND ABBREVIATIONS CNDH Comisión Nacional de los Derechos Humanos GN...Alicia Hernández Chávez, “Origen y ocaso del ejército porfiriano,” Historia Mexicana 39 (1989), 285. 72 Camp, “Mexico,” 274–275. 25... Derechos Humanos (CNDH), the government demanded action.130 Three months after the incident, the CNDH prompted the military justice system to act

  7. Drug and Immigration Issues in the Mexico-US Relationship

    DTIC Science & Technology

    1994-06-01

    norms of international law. Jorge Vargas. Manual de Derecho Internacional para Oficiales de la Armada de Mexico. Politica Internacional Mexicana. 41...p.10. 8o Univision. May 14/94. By Armando Guzman. Peru and Brlibia Increase their Drug Production. 81 Leonidas Gomez 0. Cartel. Historia de la Droga...they will remain intoxicated for at least two hours, and they would be paying $1 person-hour for the 83 Leonidas Gomez 0. Cartel Historia de la Droga. p

  8. Chromosome and gene copy number variation allow major structural change between species and strains of Leishmania.

    PubMed

    Rogers, Matthew B; Hilley, James D; Dickens, Nicholas J; Wilkes, Jon; Bates, Paul A; Depledge, Daniel P; Harris, David; Her, Yerim; Herzyk, Pawel; Imamura, Hideo; Otto, Thomas D; Sanders, Mandy; Seeger, Kathy; Dujardin, Jean-Claude; Berriman, Matthew; Smith, Deborah F; Hertz-Fowler, Christiane; Mottram, Jeremy C

    2011-12-01

    Leishmania parasites cause a spectrum of clinical pathology in humans ranging from disfiguring cutaneous lesions to fatal visceral leishmaniasis. We have generated a reference genome for Leishmania mexicana and refined the reference genomes for Leishmania major, Leishmania infantum, and Leishmania braziliensis. This has allowed the identification of a remarkably low number of genes or paralog groups (2, 14, 19, and 67, respectively) unique to one species. These were found to be conserved in additional isolates of the same species. We have predicted allelic variation and find that in these isolates, L. major and L. infantum have a surprisingly low number of predicted heterozygous SNPs compared with L. braziliensis and L. mexicana. We used short read coverage to infer ploidy and gene copy numbers, identifying large copy number variations between species, with 200 tandem gene arrays in L. major and 132 in L. mexicana. Chromosome copy number also varied significantly between species, with nine supernumerary chromosomes in L. infantum, four in L. mexicana, two in L. braziliensis, and one in L. major. A significant bias against gene arrays on supernumerary chromosomes was shown to exist, indicating that duplication events occur more frequently on disomic chromosomes. Taken together, our data demonstrate that there is little variation in unique gene content across Leishmania species, but large-scale genetic heterogeneity can result through gene amplification on disomic chromosomes and variation in chromosome number. Increased gene copy number due to chromosome amplification may contribute to alterations in gene expression in response to environmental conditions in the host, providing a genetic basis for disease tropism.

  9. Chemotherapy and Drug Targeting in the Treatment of Leishmaniasis

    DTIC Science & Technology

    1990-05-30

    Metabolism of S-adenosylhomosysteine .............. 5 3. Structure of Comon Polyamines .................................... 7 4. Separation of DNA Polymerases...4R 20. Inhibition of Leishmania by Sinefungin ............................ 49 21. Toxic Inhibition of L. mexicana by an Extract of Elephant Garlic...their infected hosts is unknown. M ost of the major metabolic pathways in the parasitic protozoa have been reported to be similar to those of the

  10. Flavonoids from Tilia americana with anxiolytic activity in plus-maze test.

    PubMed

    Herrera-Ruiz, Maribel; Román-Ramos, Rubén; Zamilpa, Alejandro; Tortoriello, Jaime; Jiménez-Ferrer, J Enrique

    2008-07-23

    The aerial parts of Tilia americana var. mexicana (Schltdl) Hardin (Tiliaceae) have been widely used in Mexican traditional medicine to relieve sleeplessness, headache, and nervous excitement. The anxiolytic effect of four extracts and several flavonoid fractions from the bracts of Tilia americana subsp.mexicana, var. mexicana (Schltdl) Hardin or Tilia mexicana (Tiliaceae) was studied. Administration of 100mg/kg of n-hexane, ethyl acetate, and aqueous extracts to elevated plus-maze (EPM)-exposed mice displayed no anxiolytic effect; however, identical doses of methanol extract was able to increase the time percentage that mice spent in the EPM's open arms, as well as the percentage of crossings in the EPM's arms. The dose-response curve produced by methanol extract showed anxiolytic activity since 25mg/kg; animals showed no motor activity alteration in the open field test (OFT). Methanol extract was subjected to a bioassay-guided fractionation to obtain four ascendant polarity fractions (F1-F4) which were administrated at 100mg/kg. Data results indicate that F1 displayed the main anxiolytic effect. The purification of F1 produced a rich flavonoid anxiolytic mixture (F1C). This fraction was purified by RP-18 open chromatographic column to obtain four polar descent fractions: F1C(1), F1C(2), F1C(3), and F1C(4), respectively. Tiliroside was the major ingredient from the active fraction. High performance liquid chromatography analysis indicated that F1C was constituted principally of tiliroside, quercetin, quercitrin, kaempherol, and their glycosides. These results supported the use of Tilia americana in Mexican traditional medicine as well as the anxiolytic effect of a rich flavonoid fraction without affect motor activity.

  11. Phylogeny of the genus Pistacia as determined from analysis of the chloroplast genome

    PubMed Central

    Parfitt, Dan E.; Badenes, Maria L.

    1997-01-01

    Classification within the genus Pistacia has been based on leaf morphology and geographical distribution. Molecular genetic tools (PCR amplification followed by restriction analysis of a 3.2-kb region of variable chloroplast DNA, and restriction fragment length polymorphism analysis of the Pistacia cpDNA with tobacco chloroplast DNA probes) provided a new set of variables to study the phylogenetic relationships of 10 Pistacia species. Both parsimony and cluster analyses were used to divide the genus into two major groups. P. vera was determined to be the least derived species. P. weinmannifolia, an Asian species, is most closely related to P. texana and P. mexicana, New World species. These three species share a common origin, suggesting that a common ancestor of P. texana and P. mexicana originated in Asia. P. integerrima and P. chinensis were shown to be distinct whereas the pairs of species were monophyletic within each of two tertiary groups, P. vera:P. khinjuk and P. mexicana:P. texana. An evolutionary trend from large to small nuts and leaves with few, large leaflets to many, small leaflets was supported. The genus Pistacia was shown to have a low chloroplast DNA mutation rate: 0.05–0.16 times that expected of annual plants. PMID:9223300

  12. Distribution of Lutzomyia ayacuchensis, the vector of Andean-type cutaneous leishmaniasis, at different altitudes on the Andean slope of Ecuador.

    PubMed

    Gomez, Eduardo A; Kato, Hirotomo; Mimori, Tatsuyuki; Hashiguchi, Yoshihisa

    2014-09-01

    Distribution of the vector species is a major risk factor for the endemicity of leishmaniasis. In the present study, the vertical distribution of Lutzomyia (Lu.) ayacuchensis, the vector of Leishmania (Leishmania) mexicana in the Ecuadorian Andes, was surveyed at different altitudes (300-2500m above sea level) of the Andean slope. The vector species Lu. ayacuchensis was identified at an altitude of 650m and a higher areas, and higher distribution ratio of the species was observed at higher altitudes. In addition, high ratios of L. (L.) mexicana infection were detected in higher areas, but none in lower populations of sand flies. Since an association between sand fly populations and vector competence is suggested in Lu. ayacuchensis, haplotype analysis was performed on the species from different altitudes of the study areas; however, no apparent difference was observed among populations. These results suggested that Lu. ayacuchensis in Andean slope areas of Ecuador has the potential to transmit L. (L.) mexicana and spread leishmaniasis in these areas.

  13. Complementary effect of natural and sexual selection against immigrants maintains differentiation between locally adapted fish

    NASA Astrophysics Data System (ADS)

    Plath, Martin; Riesch, Rüdiger; Oranth, Alexandra; Dzienko, Justina; Karau, Nora; Schießl, Angela; Stadler, Stefan; Wigh, Adriana; Zimmer, Claudia; Arias-Rodriguez, Lenin; Schlupp, Ingo; Tobler, Michael

    2010-08-01

    Adaptation to ecologically heterogeneous environments can drive speciation. But what mechanisms maintain reproductive isolation among locally adapted populations? Using poeciliid fishes in a system with naturally occurring toxic hydrogen sulfide, we show that (a) fish from non-sulfidic sites ( Poecilia mexicana) show high mortality (95 %) after 24 h when exposed to the toxicant, while locally adapted fish from sulfidic sites ( Poecilia sulphuraria) experience low mortality (13 %) when transferred to non-sulfidic water. (b) Mate choice tests revealed that P. mexicana females exhibit a preference for conspecific males in non-sulfidic water, but not in sulfidic water, whereas P. sulphuraria females never showed a preference. Increased costs of mate choice in sulfidic, hypoxic water, and the lack of selection for reinforcement due to the low survival of P. mexicana may explain the absence of a preference in P. sulphuraria females. Taken together, our study may be the first to demonstrate independent—but complementary—effects of natural and sexual selection against immigrants maintaining differentiation between locally adapted fish populations.

  14. Comparison of DNA restriction fragment length polymorphisms of Nostoc strains in and from cycads.

    PubMed

    Lindblad, P; Haselkorn, R; Bergman, B; Nierzwicki-Bauer, S A

    1989-01-01

    DNA was prepared from cyanobacteria freshly isolated from coralloid roots of natural populations of five cycad species: Ceratozamia mexicana mexicana (Mexico), C. mexicana robusta (Mexico), Dioon spinulosum (Mexico), Zamia furfuraceae (Mexico) and Z. skinneri (Costa Rica). Using the Southern blot technique and cloned Anabaena PCC 7120 nifK and glnA genes as probes, restriction fragment length polymorphisms of these cyanobacterial symbionts were compared. The five cyanobacterial preparations showed differences in the sizes of their DNA fragments hybridizing with both probes, indicating that different cyanobacterial species and/or strains were in the symbiotic associations. On the other hand, a similar comparison of cyanobacteria freshly collected from a single Encephalartos altensteinii coralloid root and from three independently subcultured isolates from the same coralloid root revealed that these were likely to be one and the same organism. Moreover, the complexity of restriction patterns shows that a mixture of Nostoc strains can associate with a single cycad species although a single cyanobacterial strain can predominate in the root of a single cycad plant. Thus, a wide range of Nostoc strains appear to associate with the coralloid roots of cycads.

  15. Antiproliferative and leishmanicidal effect of ajoene on various Leishmania species: ultrastructural study.

    PubMed

    Ledezma, Eliades; Jorquera, Alicia; Bendezú, Herminia; Vivas, Julio; Pérez, Gladinex

    2002-08-01

    Ajoene [(E,Z)-4,5,9 trithiadodeca 1,6,11 triene 9-oxide], the major bioactive compound derived from garlic, shows a potent trypanolytic and antimicotic activity. In this paper we evaluate its effect on Leishmania mexicana(Lm:MHOM/VE/80/NR), L eishmania mexicana venezuelensis (Lmv: MHOM/VE/80/H16), L eishmania mexicana amazonensis (Lma: M112, IFLA/BR/67/PH8) and L eishmania donovani chagasi (Ldch: MHOM/BR/74/PP75). Ajoene showed a potent leishmanicidal activity in vitro against all species studied. Concentrations higher than 0.3 microM led to total inhibition of growth, and 10 microM induced 100% lysis of Leishmaniaafter 96 h of incubation in a chemically defined culture medium. The 50% inhibitory concentration (IC(50)) for lysis, for all species, was about to 2 microM. The effect was dose-dependent and a threefold increase in concentration (30 microM) produced 100% lysis of cultured forms after 72 h. Ultrastructural studies showed a time- and dose-dependent morphological alteration of the mitochondrial membrane and nuclear envelope, as well as the formation of large autophagic vacuoles.

  16. A focus of mucocutaneous leishmaniasis in Três Braços, Bahia, Brazil: characterization and identification of Leishmania stocks isolated from man and dogs.

    PubMed

    Cuba Cuba, C A; Miles, M A; Vexenat, A; Barker, D C; McMahon Pratt, D; Butcher, J; Barreto, A C; Marsden, P D

    1985-01-01

    The characterization and identification to species and subspecies of 20 stocks of Leishmania isolated from the region of Três Braços, Bahia, Brazil, are described: 17 stocks were from patients and three from dogs. The following techniques were used (i) biological (growth in culture, hamster tissues and phlebotomine gut), (ii) biochemical (isoenzyme and kinetoplast DNA analysis) and (iii) immunological (using monoclonal antibodies). All except two stocks belong to the L. braziliensis complex. One of these two corresponded to L. mexicana amazonensis but the other, while clearly in the mexicana complex, showed slight differences from the L. mexicana amazonensis reference strain on isoenzyme analysis. Two stocks from different lesions in the same patient and with different growth characteristics in hamster tissues were both identified as L. braziliensis braziliensis. All the fully characterized stocks of the L. braziliensis complex were identified as L. braziliensis braziliensis. L. braziliensis guyanensis was not identified. Dog and human stocks of L. braziliensis braziliensis were indistinguishable. From these findings and other evidence, L. braziliensis braziliensis seems to be the predominant species transmitted in Três Braços.

  17. Eight cases of feline cutaneous leishmaniasis in Texas.

    PubMed

    Trainor, K E; Porter, B F; Logan, K S; Hoffman, R J; Snowden, K F

    2010-11-01

    Leishmaniasis is a zoonotic disease caused by intracellular Leishmania protozoa that are transmitted by sandflies. The disease occurs in 3 forms: cutaneous, mucocutaneous, and visceral. Cutaneous leishmaniasis has been reported in cats in Europe and South America and in 1 cat from Texas. Leishmania mexicana is endemic in Texas and has been reported to cause cutaneous lesions in humans. This article describes the pathology of 8 biopsy cases of feline cutaneous leishmaniasis presented to the Texas Veterinary Medical Diagnostic Laboratory over a 3.5-year period. The median age of the cats was 3 years; each was presented with nodular, ulcerative lesions on the pinnae and less commonly on the muzzle and periorbital skin. Histologically, the lesions were nodular to diffuse histiocytic dermatitis with numerous amastigotes (2-4 μm) within macrophages and occasionally within the interstitium. Organisms were often contained within round, clear, intracellular vacuoles. In areas of necrosis, organisms were also free within the interstitium. The overlying epidermis was hyperkeratotic, hyperplastic, and often ulcerated. The organisms were not argyrophilic (Gomori methenamine silver), reacted poorly with periodic acid-Schiff reagent, and were inconsistently basophilic with Giemsa. Although not readily visible histologically, kinetoplasts were evident in amastigotes in cytologic preparations. The lesions were similar to those described for cutaneous L. mexicana infection in humans. In 5 of the 8 cats, Leishmania mexicana DNA was amplified from paraffin-embedded tissue by polymerase chain reaction and sequenced.

  18. Behavioral response of two species of stingless bees and the honey bee (Hymenoptera: Apidae) to GF-120.

    PubMed

    Gómez-Escobar, Enoc; Liedo, Pablo; Montoya, Pablo; Vandame, Rémy; Sánchez, Daniel

    2014-08-01

    We present the results of evaluating the response of three species of bees, Trigona fulviventris (Guérin), Scaptotrigona mexicana (Guérin-Meneville), and Apis mellifera (L.), to food sources baited with the toxic bait GF-120 (NF Naturalyte), a spinosad-based bait exclusively used to manage fruit flies. Groups of foragers were trained to collect honey and water from a feeder located 50 m from the colonies. Once a sufficient number of foragers were observed at the experimental location, the training feeder was changed to two or three feeders that offered either honey and water, GF-120, Captor (hydrolyzed protein), GF-120 and honey (4:6), or Captor and honey (1:19). T fulviventris and S. mexicana rarely visited GF-120, Captor, or their mixtures with honey, while approximately 28.5 and 1.5% of A. mellifera foragers visited the GF-120 and honey and Captor and honey mixtures, respectively. Our results show that GF-120 clearly repels T. fulviventris and S. mexicana, whereas for A. mellifera, repellence is not as marked when GF-120 is combined with highly nutritious substances like honey.

  19. Predator Avoidance in Extremophile Fish

    PubMed Central

    Bierbach, David; Schulte, Matthias; Herrmann, Nina; Zimmer, Claudia; Arias-Rodriguez, Lenin; Indy, Jeane Rimber; Riesch, Rüdiger; Plath, Martin

    2013-01-01

    Extreme habitats are often characterized by reduced predation pressures, thus representing refuges for the inhabiting species. The present study was designed to investigate predator avoidance of extremophile populations of Poecilia mexicana and P. sulphuraria that either live in hydrogen sulfide-rich (sulfidic) springs or cave habitats, both of which are known to have impoverished piscine predator regimes. Focal fishes that inhabited sulfidic springs showed slightly weaker avoidance reactions when presented with several naturally occurring predatory cichlids, but strongest differences to populations from non-sulfidic habitats were found in a decreased shoaling tendency with non-predatory swordtail (Xiphophorus hellerii) females. When comparing avoidance reactions between P. mexicana from a sulfidic cave (Cueva del Azufre) and the adjacent sulfidic surface creek (El Azufre), we found only slight differences in predator avoidance, but surface fish reacted much more strongly to the non-predatory cichlid Vieja bifasciata. Our third experiment was designed to disentangle learned from innate effects of predator recognition. We compared laboratory-reared (i.e., predator-naïve) and wild-caught (i.e., predator-experienced) individuals of P. mexicana from a non-sulfidic river and found no differences in their reaction towards the presented predators. Overall, our results indicate (1) that predator avoidance is still functional in extremophile Poecilia spp. and (2) that predator recognition and avoidance reactions have a strong genetic basis. PMID:25371337

  20. Cross-transmission studies with Eimeria arizonensis-like oocysts (Apicomplexa) in New World rodents of the Genera baiomys, Neotoma, Onychomys, Peromyscus, and Reithrodontomys (Muridae).

    PubMed

    Upton, S J; McAllister, C T; Brillhart, D B; Duszynski, D W; Wash, C D

    1992-06-01

    Cross-transmission experiments were performed using oocysts of an Eimeria arizonensis-like coccidian from Peromyscus leucopus and Peromyscus truei, an E. arizonensis-like coccidian from Reithrodontomys fulvescens, Eimeria baiomysis and Eimeria taylori from Baiomys taylori, Eimeria albigulae from Neotoma albigula, and Eimeria onychomysis from Onychomys spp., between representatives of the above host genera. The E. arizonensis-like coccidian from R. fulvescens infected Reithrodontomys megalotis, Reithrodontomys montanus, and Peromyscus leucopus. Oocysts of E. arizonensis from P. leucopus could be transmitted to both P. leucopus and R. megalotus. Oocysts of E. baiomysis and E. taylori infected only B. taylori. Oocysts of E. arizonensis from P. truei infected P. truei but not Neotoma mexicana or Onychomys leucogaster. Oocysts of E. albigulae from N. albigula were infective for N. mexicana but not for P. truei or O. leucogaster. Oocysts of E. onychomysis from Onychomys spp. infected O. leucogaster but not N. mexicana or P. truei. These results demonstrate that Peromyscus and Reithrodontomys, genera known to be related very closely evolutionarily, are capable of sharing E. arizonensis, whereas morphologically similar coccidians (E. albigulae, E. baiomysis, and E. onychomysis) from more distantly related hosts, are probably distinct and more stenoxenous. This also is the first report of coccidians infecting species of Reithrodontomys.