WorldWideScience
 
 
1

The activity of azithromycin against Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis in the golden hamster model A atividade da azitromicina contra a Leishmania (Viannia) braziliensis e a Leishmania (Leishmania) amazonensis no modelo golden hamster  

Directory of Open Access Journals (Sweden)

Full Text Available New therapeutic alternatives against leishmaniasis remain a priority. The activity of azithromycin against Leishmania (Leishmania) major has been previously demonstrated. Different responses among species of Leishmania make species-specific drug screening necessary. The activity of azithromycin against Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis was evaluated in golden hamsters infected through footpad injections of metacyclic promastigotes, and compared with untreated controls and animals treated with meglumine antimoniate. Footpad thickness, lesion cultures and dissemination sites were analyzed. Treatment of golden hamsters with oral azithromycin at 450mg/kg had no activity against infections with Leishmania (Leishmania) amazonensis. For infections due to Leishmania (Viannia) braziliensis, azithromycin demonstrated significant activity relative to untreated controls, but inferior to meglumine antimoniate, for controlling lesion size. Neither drug was able to totally eliminate parasites from the lesions. It was concluded that azithromycin has activity against Leishmania (Viannia) braziliensis but not against Leishmania (Leishmania) amazonensis in this model.Novas alternativas terapêuticas contra a leishmaniose são ainda uma prioridade. A atividade da azitromicina contra a Leishmania (Leishmania) major foi anteriormente demonstrada. Diferentes respostas entre as espécies de Leishmania fazem com que um screening de drogas específicas para espécies seja necessário. A atividade da azitromicina contra a Leishmania (Viannia) braziliensis e a Leishmania (Leishmania) amazonensis foi avaliada em Golden hamsters infectados a través de injeções de promastigotas metacíclicas e comparando com controles sem tratamento e animais tratados com antimoniato de N-metil-glucamina. Foram analisadas a espessura da pata, a cultura das lesões e disseminação para órgãos internos. A azitromicina oral em dose de 450mg/kg não teve atividade contra a infecção por Leishmania ( Leishmania) amazonensis. Para infecções devidas à Leishmania (Viannia) braziliensis, a azitromicina teve uma atividade significativa em relação aos controles sem tratamento, mas foi inferior ao antimoniato de N-metil-glucamina quanto ao controle do tamanho das lesões. Nenhuma das drogas conseguiu eliminar totalmente os parasitos das lesões. Foi concluído que a azitromicina tem atividade contra Leishmania (Viannia) braziliensis, mas não tem atividade contra Leishmania (Leishmania) amazonensis neste modelo.

Ángel Sinagra; Concepción Luna; David Abraham; Maria del Carmen Iannella; Adelina Riarte; Alejandro J. Krolewiecki

2007-01-01

2

The activity of azithromycin against Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis in the golden hamster model/ A atividade da azitromicina contra a Leishmania (Viannia) braziliensis e a Leishmania (Leishmania) amazonensis no modelo golden hamster  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Novas alternativas terapêuticas contra a leishmaniose são ainda uma prioridade. A atividade da azitromicina contra a Leishmania (Leishmania) major foi anteriormente demonstrada. Diferentes respostas entre as espécies de Leishmania fazem com que um screening de drogas específicas para espécies seja necessário. A atividade da azitromicina contra a Leishmania (Viannia) braziliensis e a Leishmania (Leishmania) amazonensis foi avaliada em Golden hamsters infectados a tra (more) vés de injeções de promastigotas metacíclicas e comparando com controles sem tratamento e animais tratados com antimoniato de N-metil-glucamina. Foram analisadas a espessura da pata, a cultura das lesões e disseminação para órgãos internos. A azitromicina oral em dose de 450mg/kg não teve atividade contra a infecção por Leishmania ( Leishmania) amazonensis. Para infecções devidas à Leishmania (Viannia) braziliensis, a azitromicina teve uma atividade significativa em relação aos controles sem tratamento, mas foi inferior ao antimoniato de N-metil-glucamina quanto ao controle do tamanho das lesões. Nenhuma das drogas conseguiu eliminar totalmente os parasitos das lesões. Foi concluído que a azitromicina tem atividade contra Leishmania (Viannia) braziliensis, mas não tem atividade contra Leishmania (Leishmania) amazonensis neste modelo. Abstract in english New therapeutic alternatives against leishmaniasis remain a priority. The activity of azithromycin against Leishmania (Leishmania) major has been previously demonstrated. Different responses among species of Leishmania make species-specific drug screening necessary. The activity of azithromycin against Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis was evaluated in golden hamsters infected through footpad injections of metacyclic promastigotes, (more) and compared with untreated controls and animals treated with meglumine antimoniate. Footpad thickness, lesion cultures and dissemination sites were analyzed. Treatment of golden hamsters with oral azithromycin at 450mg/kg had no activity against infections with Leishmania (Leishmania) amazonensis. For infections due to Leishmania (Viannia) braziliensis, azithromycin demonstrated significant activity relative to untreated controls, but inferior to meglumine antimoniate, for controlling lesion size. Neither drug was able to totally eliminate parasites from the lesions. It was concluded that azithromycin has activity against Leishmania (Viannia) braziliensis but not against Leishmania (Leishmania) amazonensis in this model.

Sinagra, Ángel; Luna, Concepción; Abraham, David; Iannella, Maria del Carmen; Riarte, Adelina; Krolewiecki, Alejandro J.

2007-12-01

3

Clonaje de la proteína de choque térmico de 20 kDa de Leishmania amazonensis/ Cloning of 20 kDa heat shock protein of Leishmania amazonensis  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish INTRODUCCIÓN: la inducción de las proteínas de choque térmico constituyen un mecanismo homeostático que protege a las células del efecto destructivo del calor u otras condiciones de estrés ambiental, paralelamente, ellas cumplen importantes funciones celulares. La proteína de choque térmico de 20 kDa se reportó recientemente en Leishmania amazonensis. OBJETIVO: describir la metodología utilizada para realizar el clonaje de las proteínas de choque térmico, lo (more) que permitió acometer estudios de algunas propiedades biológicas. MÉTODOS: la región codificante del gen hsp20 se amplificó mediante la reacción en cadena de la polimerasa con cebadores adecuados. El producto amplificado se clonó inicialmente en el vector pCR2.1 (Invitrogen) y después en el vector de expresión en procariotas pET-28b (Novagen), para obtener proteína recombinante. De manera paralela, el mismo fragmento se clonó en el vector de expresión en eucariotas pcDNA3 (Invitrogen) para obtener un posible preparado vacunal de ADN. Se realizó la secuenciación nucleotídica de los clones obtenidos, con la finalidad de verificar su fidelidad. RESULTADOS: se obtuvieron plásmidos recombinantes que codifican la HSP20 de Leishmania, y permiten la obtención de proteína recombinante y de ADN en forma masiva. CONCLUSIONES: ambos plásmidos fueron útiles para estudiar algunas de las propiedades biológicas de esta proteína. Este acercamiento puede ser de interés en otros trabajos de esta índole y constituir una guía metodológica. Abstract in english INTRODUCTION: the induction of heat shock proteins is a homeostatic mechanism that protects cells from the deleterious effects of thermal and other environmental stresses. In addition, they have important cell functions. The 20kDa heat shock protein in Leishmania amazonensis was recently reported. OBJECTIVE: to describe the methodology used for cloning of heat shock proteins, which allowed the study of some biological properties. METHODS: the hsp20 gene coding region was (more) amplified by polymerase chain reaction using adequate primers. The amplified product was initially cloned in pCR2.1 vector (Invitrogen) and then in pET-28b vector (Novagen), to obtain recombinant protein. The same fragment was cloned also in the eukariote expression vector pcDNA3 (Invitrogen). The nucleotidic sequencing of the different clones was made, in order to verify their fidelity. RESULTS: the recombinant plasmids that encode HSP20 protein in Leishmania and allow obtaining massively recombinant protein and DNA were produced. CONCLUSIONS: both plasmids were useful to study some of the biological properties of this protein. This approach could be useful for similar research and represent a suitable methodological guideline.

Montalvo Álvarez, Ana Margarita; Folgueira Fernández, Cristina; Requena Rolanía, José María

2009-08-01

4

Clonaje de la proteína de choque térmico de 20 kDa de Leishmania amazonensis Cloning of 20 kDa heat shock protein of Leishmania amazonensis  

Directory of Open Access Journals (Sweden)

Full Text Available INTRODUCCIÓN: la inducción de las proteínas de choque térmico constituyen un mecanismo homeostático que protege a las células del efecto destructivo del calor u otras condiciones de estrés ambiental, paralelamente, ellas cumplen importantes funciones celulares. La proteína de choque térmico de 20 kDa se reportó recientemente en Leishmania amazonensis. OBJETIVO: describir la metodología utilizada para realizar el clonaje de las proteínas de choque térmico, lo que permitió acometer estudios de algunas propiedades biológicas. MÉTODOS: la región codificante del gen hsp20 se amplificó mediante la reacción en cadena de la polimerasa con cebadores adecuados. El producto amplificado se clonó inicialmente en el vector pCR2.1 (Invitrogen) y después en el vector de expresión en procariotas pET-28b (Novagen), para obtener proteína recombinante. De manera paralela, el mismo fragmento se clonó en el vector de expresión en eucariotas pcDNA3 (Invitrogen) para obtener un posible preparado vacunal de ADN. Se realizó la secuenciación nucleotídica de los clones obtenidos, con la finalidad de verificar su fidelidad. RESULTADOS: se obtuvieron plásmidos recombinantes que codifican la HSP20 de Leishmania, y permiten la obtención de proteína recombinante y de ADN en forma masiva. CONCLUSIONES: ambos plásmidos fueron útiles para estudiar algunas de las propiedades biológicas de esta proteína. Este acercamiento puede ser de interés en otros trabajos de esta índole y constituir una guía metodológica.INTRODUCTION: the induction of heat shock proteins is a homeostatic mechanism that protects cells from the deleterious effects of thermal and other environmental stresses. In addition, they have important cell functions. The 20kDa heat shock protein in Leishmania amazonensis was recently reported. OBJECTIVE: to describe the methodology used for cloning of heat shock proteins, which allowed the study of some biological properties. METHODS: the hsp20 gene coding region was amplified by polymerase chain reaction using adequate primers. The amplified product was initially cloned in pCR2.1 vector (Invitrogen) and then in pET-28b vector (Novagen), to obtain recombinant protein. The same fragment was cloned also in the eukariote expression vector pcDNA3 (Invitrogen). The nucleotidic sequencing of the different clones was made, in order to verify their fidelity. RESULTS: the recombinant plasmids that encode HSP20 protein in Leishmania and allow obtaining massively recombinant protein and DNA were produced. CONCLUSIONS: both plasmids were useful to study some of the biological properties of this protein. This approach could be useful for similar research and represent a suitable methodological guideline.

Ana Margarita Montalvo Álvarez; Cristina Folgueira Fernández; José María Requena Rolanía

2009-01-01

5

Subcellular localization of an intracellular serine protease of 68 kDa in Leishmania (Leishmania) amazonensis promastigotes  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Here we report the subcellular localization of an intracellular serine protease of 68 kDa in axenic promastigotes of Leishmania (Leishmania) amazonensis, using subcellular fractionation, enzymatic assays, immunoblotting, and immunocytochemistry. All fractions were evaluated by transmission electron microscopy and the serine protease activity was measured during the cell fractionation procedure using a-N-r-tosyl-L-arginine methyl ester (L-TAME) as substrate, phenylmethylsu (more) lphone fluoride (PMSF) and L-1-tosylamino-2-phenylethylchloromethylketone (TPCK) as specific inhibitors. The enzymatic activity was detected mainly in a membranous vesicular fraction (6.5-fold enrichment relative to the whole homogenate), but also in a crude plasma membrane fraction (2.0-fold). Analysis by SDS-PAGE gelatin under reducing conditions demonstrated that the major proteolytic activity was found in a 68 kDa protein in all fractions studied. A protein with identical molecular weight was also recognized in immunoblots by a polyclonal antibody against serine protease (anti-SP), with higher immunoreactivity in the vesicular fraction. Electron microscopic immunolocalization using the same polyclonal antibody showed the enzyme present at the cell surface, as well as in cytoplasmic membranous compartments of the parasite. Our findings indicate that the internal location of this serine protease in L. amazonensis is mainly restricted to the membranes of intracellular compartments resembling endocytic/exocytic elements.

Morgado-Díaz, José Andrés; Silva-Lopez, Raquel Elisa da; Alves, Carlos Roberto; Soares, Maurilio José; Corte-Real, Suzana; De Simone, Salvatore Giovanni

2005-07-01

6

Subcellular localization of an intracellular serine protease of 68 kDa in Leishmania (Leishmania) amazonensis promastigotes  

Directory of Open Access Journals (Sweden)

Full Text Available Here we report the subcellular localization of an intracellular serine protease of 68 kDa in axenic promastigotes of Leishmania (Leishmania) amazonensis, using subcellular fractionation, enzymatic assays, immunoblotting, and immunocytochemistry. All fractions were evaluated by transmission electron microscopy and the serine protease activity was measured during the cell fractionation procedure using a-N-r-tosyl-L-arginine methyl ester (L-TAME) as substrate, phenylmethylsulphone fluoride (PMSF) and L-1-tosylamino-2-phenylethylchloromethylketone (TPCK) as specific inhibitors. The enzymatic activity was detected mainly in a membranous vesicular fraction (6.5-fold enrichment relative to the whole homogenate), but also in a crude plasma membrane fraction (2.0-fold). Analysis by SDS-PAGE gelatin under reducing conditions demonstrated that the major proteolytic activity was found in a 68 kDa protein in all fractions studied. A protein with identical molecular weight was also recognized in immunoblots by a polyclonal antibody against serine protease (anti-SP), with higher immunoreactivity in the vesicular fraction. Electron microscopic immunolocalization using the same polyclonal antibody showed the enzyme present at the cell surface, as well as in cytoplasmic membranous compartments of the parasite. Our findings indicate that the internal location of this serine protease in L. amazonensis is mainly restricted to the membranes of intracellular compartments resembling endocytic/exocytic elements.

José Andrés Morgado-Díaz; Raquel Elisa da Silva-Lopez; Carlos Roberto Alves; Maurilio José Soares; Suzana Corte-Real; Salvatore Giovanni De Simone

2005-01-01

7

Leishmania mexicana amazonensis: heterogeneity in 5-nucleotidase and peroxidase activities of mononuclear phagocytes during in vivo and in vitro infection Leishmania mexicana amazonensis: heterogeneidade da 5’-Nucleotidase e da peroxidase em fagócitos mononucleares durante infecção in vivo e in vitro  

Directory of Open Access Journals (Sweden)

Full Text Available The degree of maturation of cells of the Mononuclear Phagocyte System (MPS), during in vivo and in vitro infection by Leishmania mexicana amazonenesis, was evaluated in this study. The macrophages' differentiation was assayed by cytochemical characterization at the ultrastrctural level, using two well-established markers: 5'-nucleotidase enzyme activity, for revealing the mature cells, and the peroxidase activity present in the cell granules to demonstrate immature mononuclear phagocytes. only a few mcrophages, demonstrating 5'-nucleotidase positive reaction in both the plasma membrane and within their cytoplasmic vesicles, were found scattered in the chronic inflammation at the L. m. amazonensis lesions in albino mice. However, by the peroxidase activity analysis, we were also able to demonstrate the presence of immature MPS cells, which predominate, together with parasitized vacuolated macrophages, in chronic lesions induced in this systemby L. m. amazonensis. The implications of these results on the pathogenesis of murine cutaneous leishmaniasis are discussed.Um estudo sobre o grau de maturação das células do Sistema Fagocítico Mononuclear foi realizado durante a infecção in vivo e in vitro com a Leishmania mexicana amazonensis. A caracterização da diferenciação das células fagocíticas foi obtida com a localização ultraestrutural de dois marcadores enzimáticos bam conhecidos: a enzima 5'-Nucleotidase marcadora de membrana plasmática de células maduras e a enzima peroxidase, presente em grânulos, marcadora de células imaturas. A atividade da enzima 5'-Nucleotidase foi encontrada apenas em alguns macrófagos, presentes no foco inflamatório, em projeções da membrana plasmática e em algumas vesículas citoplasmáticas. Macrófagos peritoneais de camundongo apresentaram a mesma reatividade para este marcador. Contudo a análise da atividade peroxidásica demonstrou a predominância da presença de fagócitos mononucleares imaturos nas lesões crônicas induzidas neste sistema por Leishmania mexicana amazonensis.

Suzana Côrte-Real; Gabriel Grimaldi Junior; Maria de Nazareth Leal de Meirelles

1988-01-01

8

Role of Leishmania (Leishmania) amazonensis amastigote glycosphingolipids in macrophage infectivity.  

UK PubMed Central (United Kingdom)

The role of glycosphingolipids (GSLs) present in amastigote forms of Leishmania (Leishmania) amazonensis during infection of macrophages was analyzed, with particular emphasis on GSLs presenting the terminal Galpss1-3Galpa disaccharide. Macrophage invasion by L. (L.) amazonensis amastigotes was reduced by 37% when the disaccharide Galpss1-3Galp (1 mM) was added to the culture medium. The putative macrophage receptor/lectin for ss-Gal-globotriaosylceramide (Galpss1-3Galpa1-4Galpss1-4Glc pss1-1Cer) and other structurally related GSLs from L. (L.) amazonensis amastigotes were analyzed by micelles and parasite binding assay to peritoneal macrophage proteins fractionated by SDS-PAGE under nonreducing conditions. Micelles containing purified amastigote GSLs or a suspention of L. (L.) amazonensis amastigotes fixed with 2% formaldehyde were incubated with nitrocellulose membrane containing the macrophage proteins transferred by Western blotting. Binding of micelles containing purified GSLs from amastigote forms or fixed L. (L.) amazonensis amastigotes to nitrocellulose membrane was probed using monoclonal antibody ST-3, which recognizes the glycoepitope Galpss1-3Galpa1-R present either in the micelle preparation or on the amastigote surface. Macrophage protein with molecular mass ~30 kDa bound the amastigote GSL and appeared to be a doublet on electrophoresis. The specificity of this interaction was confirmed using fixed L. (L.) chagasi amastigotes, which do not express GSLs such as ss-Galp-globotriaosylceramides, and which do not bind to 30-kDa protein.

Tanaka AK; Gorin PA; Takahashi HK; Straus AH

2007-06-01

9

Role of Leishmania (Leishmania) amazonensis amastigote glycosphingolipids in macrophage infectivity.  

Science.gov (United States)

The role of glycosphingolipids (GSLs) present in amastigote forms of Leishmania (Leishmania) amazonensis during infection of macrophages was analyzed, with particular emphasis on GSLs presenting the terminal Galpss1-3Galpa disaccharide. Macrophage invasion by L. (L.) amazonensis amastigotes was reduced by 37% when the disaccharide Galpss1-3Galp (1 mM) was added to the culture medium. The putative macrophage receptor/lectin for ss-Gal-globotriaosylceramide (Galpss1-3Galpa1-4Galpss1-4Glc pss1-1Cer) and other structurally related GSLs from L. (L.) amazonensis amastigotes were analyzed by micelles and parasite binding assay to peritoneal macrophage proteins fractionated by SDS-PAGE under nonreducing conditions. Micelles containing purified amastigote GSLs or a suspention of L. (L.) amazonensis amastigotes fixed with 2% formaldehyde were incubated with nitrocellulose membrane containing the macrophage proteins transferred by Western blotting. Binding of micelles containing purified GSLs from amastigote forms or fixed L. (L.) amazonensis amastigotes to nitrocellulose membrane was probed using monoclonal antibody ST-3, which recognizes the glycoepitope Galpss1-3Galpa1-R present either in the micelle preparation or on the amastigote surface. Macrophage protein with molecular mass ~30 kDa bound the amastigote GSL and appeared to be a doublet on electrophoresis. The specificity of this interaction was confirmed using fixed L. (L.) chagasi amastigotes, which do not express GSLs such as ss-Galp-globotriaosylceramides, and which do not bind to 30-kDa protein. PMID:17581678

Tanaka, A K; Gorin, P A J; Takahashi, H K; Straus, A H

2007-06-01

10

Role of Leishmania (Leishmania) amazonensis amastigote glycosphingolipids in macrophage infectivity  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The role of glycosphingolipids (GSLs) present in amastigote forms of Leishmania (Leishmania) amazonensis during infection of macrophages was analyzed, with particular emphasis on GSLs presenting the terminal Galpß1-3Galpa disaccharide. Macrophage invasion by L. (L.) amazonensis amastigotes was reduced by 37% when the disaccharide Galpß1-3Galp (1 mM) was added to the culture medium. The putative macrophage receptor/lectin for ß-Gal-globotriaosylceramide (Galpß1-3Galpa1 (more) -4Galpß1-4Glc pß1-1Cer) and other structurally related GSLs from L. (L.) amazonensis amastigotes were analyzed by micelles and parasite binding assay to peritoneal macrophage proteins fractionated by SDS-PAGE under nonreducing conditions. Micelles containing purified amastigote GSLs or a suspention of L. (L.) amazonensis amastigotes fixed with 2% formaldehyde were incubated with nitrocellulose membrane containing the macrophage proteins transferred by Western blotting. Binding of micelles containing purified GSLs from amastigote forms or fixed L. (L.) amazonensis amastigotes to nitrocellulose membrane was probed using monoclonal antibody ST-3, which recognizes the glycoepitope Galpß1-3Galpa1-R present either in the micelle preparation or on the amastigote surface. Macrophage protein with molecular mass ~30 kDa bound the amastigote GSL and appeared to be a doublet on electrophoresis. The specificity of this interaction was confirmed using fixed L. (L.) chagasi amastigotes, which do not express GSLs such as ß-Galp-globotriaosylceramides, and which do not bind to 30-kDa protein.

Tanaka, A.K.; Gorin, P.A.J.; Takahashi, H.K.; Straus, A.H.

2007-06-01

11

Role of Leishmania (Leishmania) amazonensis amastigote glycosphingolipids in macrophage infectivity  

Directory of Open Access Journals (Sweden)

Full Text Available The role of glycosphingolipids (GSLs) present in amastigote forms of Leishmania (Leishmania) amazonensis during infection of macrophages was analyzed, with particular emphasis on GSLs presenting the terminal Galpß1-3Galpa disaccharide. Macrophage invasion by L. (L.) amazonensis amastigotes was reduced by 37% when the disaccharide Galpß1-3Galp (1 mM) was added to the culture medium. The putative macrophage receptor/lectin for ß-Gal-globotriaosylceramide (Galpß1-3Galpa1-4Galpß1-4Glc pß1-1Cer) and other structurally related GSLs from L. (L.) amazonensis amastigotes were analyzed by micelles and parasite binding assay to peritoneal macrophage proteins fractionated by SDS-PAGE under nonreducing conditions. Micelles containing purified amastigote GSLs or a suspention of L. (L.) amazonensis amastigotes fixed with 2% formaldehyde were incubated with nitrocellulose membrane containing the macrophage proteins transferred by Western blotting. Binding of micelles containing purified GSLs from amastigote forms or fixed L. (L.) amazonensis amastigotes to nitrocellulose membrane was probed using monoclonal antibody ST-3, which recognizes the glycoepitope Galpß1-3Galpa1-R present either in the micelle preparation or on the amastigote surface. Macrophage protein with molecular mass ~30 kDa bound the amastigote GSL and appeared to be a doublet on electrophoresis. The specificity of this interaction was confirmed using fixed L. (L.) chagasi amastigotes, which do not express GSLs such as ß-Galp-globotriaosylceramides, and which do not bind to 30-kDa protein.

A.K. Tanaka; P.A.J. Gorin; H.K. Takahashi; A.H. Straus

2007-01-01

12

Effects of Brazilian propolis on Leishmania amazonensis  

Directory of Open Access Journals (Sweden)

Full Text Available Leishmaniasis, an endemic parasitosis that leads to chronic cutaneous, mucocutaneous or visceral lesions, is part of those diseases, which still requires improved control tools. Propolis has shown activities against different bacteria, fungi, and parasites. In this study we investigated the effect of four ethanolic extracts of typified propolis collected in different Brazilian states, on Leishmania amazonensis performing assays with promastigote forms, extracellular amastigotes, and on infected peritoneal macrophages. Ethanolic extracts of all propolis samples (BRG, BRPG, BRP-1, and BRV) were capable to reduce parasite load as monitored by the percentage of infected macrophages and the number of intracellular parasites. BRV sample called red propolis, collected in the state of Alagoas, and containing high concentration of prenylated and benzophenones compounds, was the most active extract against L. amazonensis. The anti-Leishmania effect of BRV sample was increased in a concentration and time dependent manner. BRV treatment proved to be non-toxic to macrophage cultures. Since BRV extract at the concentration of 25 µg/ml reduced the parasite load of macrophages while presented no direct toxic to promastigotes and extracellular amastigotes, it was suggested that constituents of propolis intensify the mechanism of macrophage activation leading to killing of L. amazonensis. Our results demonstrate, for the first time, that ethanolic extracts of Brazilian propolis reduce L. amazonensis infection in macrophages, and encourage further studies of this natural compound in animal models of leishmaniasis.

Diana Copi Ayres; Maria Cristina Marcucci; Selma Giorgio

2007-01-01

13

Different secreted phosphatase activities in Leishmania amazonensis.  

UK PubMed Central (United Kingdom)

Leishmania has strong acid phosphatase activity on the external surface of the plasma membrane and secreted into the extracellular milieu. Secreted acid phosphatase (sAcP), which is the most abundant secreted protein of Leishmania, is also a virulence factor that plays a role in vertebrate infection and survival in sand flies. In this study, we characterized the secreted phosphatase activities in Leishmania amazonensis. Both acidic and alkaline secreted phosphatase activities were observed with ?-glycerophosphate and p-nitrophenyl phosphate (p-NPP) hydrolysis and were inhibited with sodium tartrate and sodium orthovanadate. Cytochemical labeling revealed a significant difference in the localization of the electron-dense precipitates depending on the substrate. ?-Glycerophosphate electron-dense precipitates were concentrated on both the cell surface and flagellar pocket, whereas p-NPP labeling occurred primarily within intracellular organelles. Orthovanadate-treated metacyclic promastigotes were less infective and were confined to a tight parasitophorous vacuole (PV), which is not characteristic of this Leishmania species. Based on the results, we characterized the presence of different secreted phosphatase activities in L. amazonensis, the influence of the substrate in cytochemical labeling, and the potential involvement of secreted phosphatase activity in both PV maturation and amastigote survival.

Fernandes AC; Soares DC; Saraiva EM; Meyer-Fernandes JR; Souto-Padrón T

2013-03-01

14

Activity of Cuban Plants Extracts against Leishmania amazonensis.  

Science.gov (United States)

Natural products have long been providing important drug leads for infectious diseases. Leishmaniasis is a major health problem worldwide that affects millions of people especially in the developing nations. There is no immunoprophylaxis (vaccination) available for Leishmania infections, and conventional treatments are unsatisfactory; therefore, antileishmanial drugs are urgently needed. In this work, 48 alcoholic extracts from 46 Cuban plants were evaluated by an in vitro bioassay against Leishmania amazonensis. Furthermore, their toxicity was assayed against murine macrophage. The three most potent extracts against the amastigote stage of Leishmania amazonensis were from Hura crepitans, Bambusa vulgaris, and Simarouba glauca. PMID:22530133

García, Marley; Monzote, Lianet; Scull, Ramón; Herrera, Pedro

2012-03-15

15

Activity of Cuban Plants Extracts against Leishmania amazonensis.  

UK PubMed Central (United Kingdom)

Natural products have long been providing important drug leads for infectious diseases. Leishmaniasis is a major health problem worldwide that affects millions of people especially in the developing nations. There is no immunoprophylaxis (vaccination) available for Leishmania infections, and conventional treatments are unsatisfactory; therefore, antileishmanial drugs are urgently needed. In this work, 48 alcoholic extracts from 46 Cuban plants were evaluated by an in vitro bioassay against Leishmania amazonensis. Furthermore, their toxicity was assayed against murine macrophage. The three most potent extracts against the amastigote stage of Leishmania amazonensis were from Hura crepitans, Bambusa vulgaris, and Simarouba glauca.

García M; Monzote L; Scull R; Herrera P

2012-01-01

16

Miltefosine induces programmed cell death in Leishmania amazonensis promastigotes  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english In the current study, we evaluated the mechanism of action of miltefosine, which is the first effective and safe oral treatment for visceral leishmaniasis, in Leishmania amazonensis promastigotes. Miltefosine induced a process of programmed cell death, which was determined by the externalization of phosphatidylserine, the incorporation of propidium iodide, cell-cycle arrest at the sub-G0/G1 phase and DNA fragmentation into oligonucleosome-sized fragments. Despite the intr (more) insic variation that is detected in Leishmania spp, our results indicate that miltefosine causes apoptosis-like death in L. amazonensis promastigote cells using a similar process that is observed in Leishmania donovani.

Marinho, Fernanda de Aquino; Gonçalves, Keyla Cristiny da Silva; Oliveira, Selma Soares de; Oliveira, Ana-Carolina de Siqueira Couto de; Bellio, Maria; d'Avila-Levy, Claudia Masini; Santos, André Luis Souza dos; Branquinha, Marta Helena

2011-06-01

17

Analysis and chromosomal mapping of Leishmania (Leishmania) amazonensis amastigote expressed sequence tags  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The characterization of expressed sequence tags (ESTs) generated from a cDNA library of Leishmania (Leishmania) amazonensis amastigotes is described. The sequencing of 93 clones generated new L. (L.) amazonensis ESTs from which 32% are not related to any other sequences in database and 68% presented significant similarities to known genes. The chromosome localization of some L. (L.) amazonensis ESTs was also determined in L. (L.) amazonensis and L. (L.) major. The charact (more) erization of these ESTs is suitable for the genome physical mapping, as well as for the identification of genes encoding cysteine proteinases implicated with protective immune responses in leishmaniasis.

Gentil, Luciana Girotto; Lasakosvitsch, Fernanda; Silveira, José Franco da; Santos, Márcia Regina Machado dos; Barbiéri, Clara Lúcia

2007-09-01

18

Analysis and chromosomal mapping of Leishmania (Leishmania) amazonensis amastigote expressed sequence tags  

Directory of Open Access Journals (Sweden)

Full Text Available The characterization of expressed sequence tags (ESTs) generated from a cDNA library of Leishmania (Leishmania) amazonensis amastigotes is described. The sequencing of 93 clones generated new L. (L.) amazonensis ESTs from which 32% are not related to any other sequences in database and 68% presented significant similarities to known genes. The chromosome localization of some L. (L.) amazonensis ESTs was also determined in L. (L.) amazonensis and L. (L.) major. The characterization of these ESTs is suitable for the genome physical mapping, as well as for the identification of genes encoding cysteine proteinases implicated with protective immune responses in leishmaniasis.

Luciana Girotto Gentil; Fernanda Lasakosvitsch; José Franco da Silveira; Márcia Regina Machado dos Santos; Clara Lúcia Barbiéri

2007-01-01

19

Studies on the effectiveness of diarylheptanoids derivatives against Leishmania amazonensis  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english In a previous work we demonstrated that diarylheptanoids extracted from Centrolobium sclerophyllum are very active against Leishmania amazonensis promastigotes. In order to continue our studies with these class of compounds, we decided to evaluate the activity of several diarylheptanoids derived from curcumin (diferuloyl methane) against the extracellular form (promastigotes) of L. amazonensis. Furthermore, an experiment against the intracellular form of the parasite (ama (more) stigotes) was carried out, comparing the most active compound among the curcumin derivatives (the methylcurcumin) with des-O-methylcentrolobine, the most active diarylheptanoid derived from C. sclerophyllum.

Araujo, Catarina AC; Alegrio, Leila V; Gomes, Denise CF; Lima, Marco Edilson F; Gomes-Cardoso, Leonardo; Leon, Leonor L

1999-11-01

20

Interleukin- 2 production during murine infection by Leishmania mexicana amazonensis  

Directory of Open Access Journals (Sweden)

Full Text Available Highly susceptible BALB/c mice, resistant C57B1/6 and their F1 progeny (BDF1) were infected subcutaneously in the foot pad with Leishmania mexicana amazonenesis. At various times after infection, spleen or draining popliteal lymph node cells were assayed for their capacity to generate Interleukin-2 (I1-2) by Concanavalin A (ConA) stimulation. In both BALB/c and C57B1/6 strains there was a transient increase in their capacity to produce I1-2, from the 3rd to the 10th week post-infection. Return to pre-infection levels ocurred between 13th to 16th week post-infection in all three strains. BALB/c mice always produced higher titers of 11-2 than C57B1/6, but such differences were statistically significant only at 3 and 10 weeks post-infection. BDF1 mice had titers similar to those observed in BALB/c mice. I1-2 production by ConA-stimulated lymph node cells was lower as compared to the spleen, but with a similar pattern among the three mice strains. Our data show that susceptibility to infection by l. mexicana amazonenesis is not associated with deficient ConA-stimulated I1-2 production.Camundongos BALB/c (susceptíveis), C57B1/6 (resistentes) ou sua geração F1 (BDF) foram infectados subcutaneamente na pata traseira com Leishmania mexicana amazonensis. Avaliamos, em diferentes períodos de infecção, a capacidade de células do baço ou de linfonodo poplíteo, de produzir Interleucina-2 (I1-2) em resposta à estimulação por Conconavalina A (ConA). Nos camundongos BALB/c e C57B1/6 observamos, da 3ª à 10ª semana pós-infecção transitória da capacidade de produzir I1-2. Da 13ª à 16ª semana pós-infecção houve um retorno dos níveis de produção pré-infecção. Camundongos BALB/c produziram títulos mais elevados de I2- que os C57B1/6, mas tais diferenças só foram estatisticamente significantes na 3ª e 10ª semanas pós-infecção. Camundongos BDF1 apresentaram títulos semelhantes aos dos BALB/c. Os níveis de I1-2 (estimulada por ConA) produzidos por células do linfonodo foram mais baixos que os baço, porém com padrão semelhante. Nossos dados mostram que a susceptibilidade à infecção por L. mexicana amazonensis não está associada a um defeito de produção de I1-2, estimulada por ConA.

Manoel Barral-Netto; Silene B. Roters; Aldina Barral

1986-01-01

 
 
 
 
21

Leishmania amazonensis in dog with clinical diagnosis of visceral leishmaniasis in Paraná State, Brazil – a case reportLeishmania amazonensis em cão com quadro clínico de leishmaniose visceral no Estado do Paraná, Brasil – relato de caso  

Directory of Open Access Journals (Sweden)

Full Text Available Leishmaniasis are antropozoonoses involving various species of Leishmania and hosts, with variable clinical presentations and considered of great importance to public health. This article describes a case of canine leishmaniasis caused by Leishmania amazonensis, from the town of Cambé, Paraná state, Brazil. This state is considered endemic for American cutaneous leishmaniasis (ACL) in humans, but this is the first report in a dog in the region, caused by L. amazonensis. The taxonomic characterization of Leishmania was performed by multilocus enzyme electrophoresis technique (MLEE). Clinical signs were similar to those observed in visceral leishmaniasis as polyarthritis and progressive weight loss. It is concluded that the related polyarthritis when related to leishmaniasis, cannot be considered a clinical sign associated only with L. chagasi in view of the L. amazonensis also has this as one of its presentations. The LTA becomes a differential diagnosis of polyarthritis in dogs.As leishmanioses são antropozoonoses que envolvem diversas espécies de Leishmania e hospedeiros, tendo apresentações clínicas variáveis e consideradas de grande importância para a saúde pública. Este artigo descreve um caso de leishmaniose canina causada por Leishmania amazonensis, proveniente da cidade de Cambé, Paraná – Brasil. Este estado é considerado endêmico para a leishmaniose tegumentar americana (LTA) em humanos, porém este é o primeiro relato em cão na região, provocado pela L. amazonensis. A caracterização taxonômica da Leishmania foi realizada através da técnica multilocus enzyme electrophoresis (MLEE). Os sinais clínicos foram similares aos observados na leishmaniose visceral como poliartrite e emagrecimento progressivo. Conclui-se que a poliartrite quando relacionada à leishmaniose não pode ser considerada um sinal clínico associado somente a L. chagasi, tendo em vista que a L. amazonensis também tem esta como uma das suas formas de apresentação. A LTA torna-se um diagnóstico diferencial de poliartrite em cães.

Aline Rafaeli Hoffmann; Italmar Teodorico Navarro; Valdair Elemar Camargo Junior; Eloiza Teles Caldart; Regina Mitsuka Breganó; Patrícia Mendes Pereira

2012-01-01

22

Genomic organization of telomeric and subtelomeric sequences of Leishmania (Leishmania) amazonensis.  

Science.gov (United States)

Telomeres are DNA-protein complexes that protect linear chromosomes from degradation and fusions. Telomeric DNA is repetitive and G-rich, and protrudes towards the end of the chromosomes as 3'G-overhangs. In Leishmania spp., sequences adjacent to telomeres comprise the Leishmania conserved telomere associated sequences (LCTAS) that are around 100 bp long and contain two conserved sequence elements (CSB1 and CSB2), in addition to non-conserved sequences. The aim of this work was to study the genomic organization of Leishmania (Leishmania) amazonensis telomeric/subtelomeric sequences. Leishmania amazonensis chromosomes were separated in a single Pulsed Field Gel Electrophoresis (PFGE) gel as 25 ethidium bromide-stained bands. All of the bands hybridized with the telomeric probe (5'-TTAGGG-3')3 and with probes generated from the conserved subtelomeric elements (CSB1, CSB2). Terminal restriction fragments (TRF) of L. amazonensis chromosomes were analyzed by hybridizing restriction digested genomic DNA and chromosomal DNA separated in 2D-PFGE with the telomeric probe. The L. amazonensis TRF was estimated to be approximately 3.3 kb long and the telomeres were polymorphic and ranged in size from 0.2 to 1.0 kb. Afa I restriction sites within the conserved CSB1 elements released the telomeres from the rest of the chromosome. Bal 31-sensitive analysis confirmed the presence of terminal Afa I restriction sites and served to differentiate telomeric fragments from interstitial internal sequences. The size of the L. amazonensis 3' G-overhang was estimated by non-denaturing Southern blotting to be approximately 12 nt long. Using similar approaches, the subtelomeric domains CSB1 and CSB2 were found to be present in a low copy number compared to telomeres and were organized in blocks of 0.3-1.5 kb flanked by Hinf I and Hae III restriction sites. A model for the organization of L. amazonensis chromosomal ends is provided. PMID:16126212

Conte, F F; Cano, M I N

2005-07-07

23

Metaciclogénesis y desarrollo de Leishmania (Leishmania) amazonensis (Kinetoplastida: Trypanosomatidae) en Lutzomyia ovallesi (Diptera: Psychodidae)/ Metacyclogenesis and development of Leishmania (Leishmania) amazonensis (Kinetoplastida: Trypanosomatidae) in Lutzomyia ovallesi (Diptera: Psychodidae)  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish La interacción Leishmania-vector es un proceso complejo y multifactorial. En los últimos años se han logrado avances importantes en la relación Leishmania-vector, pero aún se desconocen algunos aspectos. Este trabajo estudia la interacción de Leishmania (Leishmania) amazonensis (Kinetoplastida: Trypanosomadidae) en Lutzomyia ovallesi (Diptera: Psychodidae). Hembras de L. ovallesi fueron infectadas artificialmente y se determinó el patrón de desarrollo, densidad pa (more) rasitaria, secuencia de morfotipos de promastigotes en las regiones del intestino, efecto de la realimentación, y el patrón de carbohidratos de la superficie de las leptomonas usando lectinas fluorescentes. Los resultados mostraron desarrollo suprapilórico de L. (L.) amazonensis. La densidad parasitaria mostró dos ciclos de división separados en tiempo y espacio, se observaron morfotipos caracterizados como paramastigotes en división. La realimentación no alteró la migración de los morfotipos y la mayor proporción de leptomonas en el intestino medio torácico sugiere migración natural que pudiera ser modulada por el gradiente de carbohidratos en el intestino del flebótomo y por la exposición de saliva. Las leptomonas exhibieron diferentes patrones de unión de glicoconjugados, que sugieren presencia de distintos residuos de carbohidratos en la superficie celular del parásito y/o flagelo, que pueden tener funciones importantes en la interacción y estabilidad de los parásitos en el lumen del intestino y su migración a las diferentes regiones del mismo. Se aportan diferentes aspectos del desarrollo de L. (L.) amazonensis en L. ovallesi importantes para entender su potencial vectorial Abstract in english Leishmania-vector interaction is a complex and multifactorial process. During the last few years important advances in the Leishmania-vector interaction have been reached but there still some unknown aspects. This work studies the Leishmania (Leishmania) amazonensis (Kinetoplastide: Trypanosomatidae) interaction in Lutzomia ovallesi (Diptera: Psychodidae). L. ovallesi females were artificially infected and the development pattern, parasite density, and promastigote morpho (more) type sequence in the intestinal regions were determined, as well as the effect of re-feeding, and the carbohydrate pattern of the leptomonad surface using fluorescent lectins. The results showed suprapiloric development of L. (L.)amazonensis. Parasite density showed two division cycles separated in time and space, morphotypes characterized as dividing paramastigotes were observed. Re-feeding did not alter the migration of morphotypes and the greater proportion of leptomonads in the middle intestine suggests a natural migration which could be modulated by the carbohydrate gradient in the phlebotom intestine and by exposure to saliva. Leptomonads exhibited different glyconjugate union patterns which suggest the presence of various carbohydrate residues in the cell surface of the parasite and/or flagellum, which can have important functions in the interaction and stability of the parasites in the intestinal lumen and their migration to the different intestinal regions. Several aspects of L. (L.)amazonensis development in L. ovallesi important for understanding its vectorial potency are discussed

Nieves, Elsa; Rondón, Maritza

2010-12-01

24

Interleukin- 2 production during murine infection by Leishmania mexicana amazonensis  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Camundongos BALB/c (susceptíveis), C57B1/6 (resistentes) ou sua geração F1 (BDF) foram infectados subcutaneamente na pata traseira com Leishmania mexicana amazonensis. Avaliamos, em diferentes períodos de infecção, a capacidade de células do baço ou de linfonodo poplíteo, de produzir Interleucina-2 (I1-2) em resposta à estimulação por Conconavalina A (ConA). Nos camundongos BALB/c e C57B1/6 observamos, da 3ª à 10ª semana pós-infecção transitória da capa (more) cidade de produzir I1-2. Da 13ª à 16ª semana pós-infecção houve um retorno dos níveis de produção pré-infecção. Camundongos BALB/c produziram títulos mais elevados de I2- que os C57B1/6, mas tais diferenças só foram estatisticamente significantes na 3ª e 10ª semanas pós-infecção. Camundongos BDF1 apresentaram títulos semelhantes aos dos BALB/c. Os níveis de I1-2 (estimulada por ConA) produzidos por células do linfonodo foram mais baixos que os baço, porém com padrão semelhante. Nossos dados mostram que a susceptibilidade à infecção por L. mexicana amazonensis não está associada a um defeito de produção de I1-2, estimulada por ConA. Abstract in english Highly susceptible BALB/c mice, resistant C57B1/6 and their F1 progeny (BDF1) were infected subcutaneously in the foot pad with Leishmania mexicana amazonenesis. At various times after infection, spleen or draining popliteal lymph node cells were assayed for their capacity to generate Interleukin-2 (I1-2) by Concanavalin A (ConA) stimulation. In both BALB/c and C57B1/6 strains there was a transient increase in their capacity to produce I1-2, from the 3rd to the 10th week (more) post-infection. Return to pre-infection levels ocurred between 13th to 16th week post-infection in all three strains. BALB/c mice always produced higher titers of 11-2 than C57B1/6, but such differences were statistically significant only at 3 and 10 weeks post-infection. BDF1 mice had titers similar to those observed in BALB/c mice. I1-2 production by ConA-stimulated lymph node cells was lower as compared to the spleen, but with a similar pattern among the three mice strains. Our data show that susceptibility to infection by l. mexicana amazonenesis is not associated with deficient ConA-stimulated I1-2 production.

Barral-Netto, Manoel; Roters, Silene B.; Barral, Aldina

1986-03-01

25

Comparative two-dimensional gel electrophoresis maps for promastigotes of Leishmania amazonensis and Leishmania major  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The outcome of Leishmania infections is determined by both the parasite species and the host genetic makeup. While much has been learned regarding immune responses to this parasite, our knowledge on parasite-derived factors is limited. The recent completion of the L. major and L. infantum genome sequence projects and concurrent advancement in proteomics technology would greatly accelerate the search for novel Leishmania proteins. Using a proteomics-based approach to study (more) species-specific Leishmania proteins, we developed high-resolution, broad pH (3-10) two-dimensional gel electrophoresis (2-DE) separations to determine protein-expression profiles between highly infectious forms of the parasitic species L. amazonensis (New World) and L. major (Old World). Approximately 1,650 and 1,530 distinct protein spots were detected in the L. amazonensis and L. major gels, respectively. While a vast majority of the spots had similar distribution and intensity, a few were computationally defined as preferentially expressed in L. amazonensis in comparison to L. major, or vice versa. These data attest to the feasibility of establishing a 2-DE-based protein array for inter-species profiling of Leishmania proteins and provide the framework for future design of proteome studies of Leishmania.

Brobey, Reynolds K. B.; Mei, Fang C.; Cheng, Xiaodong; Soong, Lynn

2006-02-01

26

In vitro and in vivo activity of a palladacycle complex on Leishmania (Leishmania) amazonensis.  

UK PubMed Central (United Kingdom)

BACKGROUND: Antitumor cyclopalladated complexes with low toxicity to laboratory animals have shown leishmanicidal effect. These findings stimulated us to test the leishmanicidal property of one palladacycle compound called DPPE 1.2 on Leishmania (Leishmania) amazonensis, an agent of simple and diffuse forms of cutaneous leishmaniasis in the Amazon region, Brazil. METHODOLOGY/PRINCIPAL FINDINGS: Promastigotes of L. (L.) amazonensis and infected bone marrow-derived macrophages were treated with different concentrations of DPPE 1.2. In in vivo assays foot lesions of L. (L.) amazonensis-infected BALB/c mice were injected subcutaneously with DPPE 1.2 and control animals received either Glucantime or PBS. The effect of DPPE 1.2 on cathepsin B activity of L. (L.) amazonensis amastigotes was assayed spectrofluorometrically by use of fluorogenic substrates. The main findings were: 1) axenic L. (L.) amazonensis promastigotes were destroyed by nanomolar concentrations of DPPE 1.2 (IC50 = 2.13 nM); 2) intracellular parasites were killed by DPPE 1.2 (IC50 = 128.35 nM), and the drug displayed 10-fold less toxicity to macrophages (CC50 = 1,267 nM); 3) one month after intralesional injection of DPPE 1.2 infected BALB/c mice showed a significant decrease of foot lesion size and a reduction of 97% of parasite burdens when compared to controls that received PBS; 4) DPPE 1.2 inhibited the cysteine protease activity of L. (L.) amazonensis amastigotes and more significantly the cathepsin B activity. CONCLUSIONS/SIGNIFICANCE: The present results demonstrated that DPPE 1.2 can destroy L. (L.) amazonensis in vitro and in vivo at concentrations that are non toxic to the host. We believe these findings support the potential use of DPPE 1.2 as an alternative choice for the chemotherapy of leishmaniasis.

Paladi Cde S; Pimentel IA; Katz S; Cunha RL; Judice WA; Caires AC; Barbiéri CL

2012-01-01

27

Immunomodulatory activity of ouabain in Leishmania leishmania amazonensis-infected Swiss mice.  

Science.gov (United States)

Ouabain is a cardiotonic steroid identified as an endogenous substance of human plasma, being produced by the adrenal, pituitary, and hypothalamus. Despite the studies demonstrating the ability of ouabain to modulate inflammation and other aspects of the immune response, the effects of this substance in Leishmaniasis is unknown. The purpose of this work was to understand the immunomodulatory activity of ouabain in experimental Leishmaniasis in Swiss mice. It was demonstrated that ouabain reduced total cell numbers in the peritoneal cavity as a reflex of the inhibition of neutrophil migration induced by Leishmania (L.) Amazonensis. Furthermore, ouabain reduced TNF-? and IFN-? levels, without cytotoxicity against peritoneal macrophages. These data showed the anti-inflammatory role of ouabain in the early events of the immune response triggered by Leishmania (L.) Amazonensis infection in murine model. PMID:23052777

Jacob, P L; Leite, J A; Alves, A K A; Rodrigues, Y K S; Amorim, F M; Néris, P L N; Oliveira, M R; Rodrigues-Mascarenhas, S

2012-10-04

28

A comparison of two distinct murine macrophage gene expression profiles in response to Leishmania amazonensis infection  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background The experimental murine model of leishmaniasis has been widely used to characterize the immune response against Leishmania. CBA mice develop severe lesions, while C57BL/6 present small chronic lesions under L. amazonensis infection. Employing a ...

Probst Christian M; Silva Rodrigo A; B Menezes Juliana P; Almeida Tais F; Gomes Ivana N; Dallabona Andréia C; Ozaki Luiz S

29

Cell migration induced by Leishmania (Leishmania) amazonensis, Leishmania (Leishmania) major and Leishmania (Viannia) braziliensis into the peritoneal cavity of BALB/c mice  

Directory of Open Access Journals (Sweden)

Full Text Available In American cutaneous leishmaniasis, the initial infection phase is characterized by recruitment of neutrophils and monocytes. The migration of these cells in response to the presence of Leishmania in the peritoneum of affected animals remains unclear. The objective of this study was to investigate cell migration to the peritoneum of BALB/c mice after infection with Leishmania (Leishmania) amazonensis, Leishmania (Viannia) braziliensis and Leishmania (Leishmania) major. Initially, Leishmania spp. was intraperitoneally inoculated in five groups of six animals each and the cell migration was analyzed 0, 3, 6, 12, 24 and 48 hours after infection. Different cell counts were performed with a staining kit and showed a higher percentage of polymorphonuclear than mononuclear cells in all three species studied. The total cell count revealed peak migration in L. (L.) amazonensis and L. (L.) major at six hours, and in L. (V.) braziliensis at 12 hours. These results suggest that factors released from different cell types probably act by attracting polymorphonuclear cells, with the peak migration most likely depending on the species of Leishmania inoculated into the host.

DT Wakimoto; KV Gaspareto; TGV Silveira; MVC Lonardoni; SMA Aristides

2010-01-01

30

Efficacy of a diarylheptanoid derivative against Leishmania amazonensis  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The activity of several diarylheptanoid derivatives (curcuminoids) was previously evaluated against Leishmania amazonensis promastigotes and among them the most active compound was the [1-(4-methoxy-phenyl)-7-(3,4-methoxy-4-hydroxy-phenyl)-1,6-heptadien-3, 5-dione]. This derivative was chosen to be assayed in vivo in a treatment trial. For these experiments, the curcuminoid compound was used in a concentration equivalent to the IC50/24 h, obtained from the previous study. (more) Balb/c mice were inoculated subcutaneously in the footpad with L. amazonensis infective promastigotes and 4 weeks after the inoculation, the animals were treated with different schemes, varying from 1 to 3 doses. In all the experiments, Pentamidine Isethionate was used as reference drug under the same experimental conditions. The results showed that one dose was not enough to heal the lesion, however, with 2 and 3 doses the efficiency of the assayed compound was clear. On the other hand, treatment with Pentamidine Isethionate using the three different schemes was not satisfactory when compared to the curcuminoid derivative.

Alves, Luciana Vignólio; Temporal, Rosane Maria; Cysne-Finkelstein, Léa; Leon, Leonor Laura

2003-06-01

31

Efficacy of a diarylheptanoid derivative against Leishmania amazonensis  

Directory of Open Access Journals (Sweden)

Full Text Available The activity of several diarylheptanoid derivatives (curcuminoids) was previously evaluated against Leishmania amazonensis promastigotes and among them the most active compound was the [1-(4-methoxy-phenyl)-7-(3,4-methoxy-4-hydroxy-phenyl)-1,6-heptadien-3, 5-dione]. This derivative was chosen to be assayed in vivo in a treatment trial. For these experiments, the curcuminoid compound was used in a concentration equivalent to the IC50/24 h, obtained from the previous study. Balb/c mice were inoculated subcutaneously in the footpad with L. amazonensis infective promastigotes and 4 weeks after the inoculation, the animals were treated with different schemes, varying from 1 to 3 doses. In all the experiments, Pentamidine Isethionate was used as reference drug under the same experimental conditions. The results showed that one dose was not enough to heal the lesion, however, with 2 and 3 doses the efficiency of the assayed compound was clear. On the other hand, treatment with Pentamidine Isethionate using the three different schemes was not satisfactory when compared to the curcuminoid derivative.

Alves Luciana Vignólio; Temporal Rosane Maria; Cysne-Finkelstein Léa; Leon Leonor Laura

2003-01-01

32

Desarrollo de Leishmania mexicana y Leishmania amazonensis en Lutzomyia evansi (Díptera: Psychodidae, Phlebotomine)/ Development of Leishmania mexicana and Leishmania amazonensis in Lutzomyia evansi (Díptera: Psychodidae, Phlebotomine)  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish El objetivo de este trabajo consistió en estudiar los cambios morfológicos que ocurren durante el desarrollo de Leishmania mexicana (MHOM/VE/72/AZV) y Le. amazonensis (IFLA/BR/67/PI18) en Lutzomyia euansi. Hembras de Lu. evansi se alimentaron a partir de una lesión tarsal de hámster y se examinaron en busca de infección cada 24 h hasta las 168 h posalimentación. El patrón de desarrollo de Le. mexicana y Le. amazonensis en Lu. euansi fue de tipo suprapilórico, de a (more) cuerdo con lo descrito para las especies del complejo Le. mexicana. La transformación de formas amastigotas a procíclicos ocurrió para ambas especies entre las 24 - 48 h postinfección. Los parásitos mostraron su adaptación al microambiente del tracto digestivo de Lu. euansi y desarrollo hacia formas maduras: nectomonas, haptomonas y paramastigotas. La forma paramastigota se observó, en bajo porcentaje, a las 120 h postingesta infectiva en ambas especies. La disminución temprana de nutrientes en Lu. euansi, debido al rápido proceso de digestión de sangre (3 a 4 días), pudiera explicar el bajo porcentaje de desarrollo alcanzado hacia las formas paramastigotas y la ausencia de formas metacíclicas en este modelo. Abstract in english The aim of this paper was to study the morphological changes in the development of Leishmania mexicana (MMOM/VE/72/AZV) and L. amazonensis (IFLA/BR/67/PI18) in Lutzomyia euansi. Pernales of Lu. euansi fed on a hámster tarsal lesión and were examined for infection at 24 h intervals from 24 h to 168 h post- feeding. The pattern of development of Le. mexicana and Le. amazonensis in Lu. euansi was suprapylarian consistentwith what has been described forspecies of the Le. me (more) xicana complex. Transformaron from amastigote to procyclical forms occurred in both species at 24 - 48 h post-infection. The parasites showed their adaptaüon lo the gut environment of Lu. euansi and development to mature forms: nectomonads, haptomonads and pararnastigotes. The paramastigote form was observed in low percentage at 120 h post-infected ingestión in both species. The early depletion of nutrients in Lu. euansi, due to a faster rate of digestión (3 to 4 days), could explain the low percentage of development reaching the paramastigote forms and the absence of the metacyclical forms in this model.

VIVENES, MARÍA ALEJANDRA; OVIEDO, MILAGROS; MÁRQUEZ, JULIO CÉSAR

2005-06-01

33

Inhibition of growth of Leishmania mexicana mexicana by Leishmania mexicana amazonensis during "in vitro" co-cultivation Inibição do crescimento de Leishmania mexicana mexicana por Leishmania mexicana amazonensis durante o co-cultivo "in vitro"  

Directory of Open Access Journals (Sweden)

Full Text Available Inhibition of one Leishmania subspecies by exometabolites of another subspecies, a phenomenon not previously reported, is suggested by our recent observations in cell cloning experiments with Leishmania mexicana mexicana and Leishmania mexicana amazonensis. Clones were identified using the technique of schizodeme analysis. The phenomenon observed is clearly relevant to studies of parasite isolation, leishmanial metabolism, cross-immunity and chemotherapy.Inhibição do crescimento de um subespécie de Leishmania por exometabólitos de outra subespécie, um fenômeno ainda não notificado, é sugerido em nossas recentes observações em experimentos de clonagem celular com Leishmania mexicana mexicana e Leishmania mexicana amazonensis. Os clones foram identificados usando a técnica de análise de esquizodemas. O fenômeno observado é claramente relevante em estudos de isolamento parasitário, metabolismo, imunidade cruzada e quimioterapia.

Raquel S. Pacheco; Gabriel Grimaldi Júnior; Carlos M. Morel

1987-01-01

34

LaRbp38: A Leishmania amazonensis protein that binds nuclear and kinetoplast DNAs  

International Nuclear Information System (INIS)

Leishmania amazonensis causes a wide spectrum of leishmaniasis. There are no vaccines or adequate treatment for leishmaniasis, therefore there is considerable interest in the identification of new targets for anti-leishmania drugs. The central role of telomere-binding proteins in cell maintenance makes these proteins potential targets for new drugs. In this work, we used a combination of purification chromatographies to screen L. amazonensis proteins for molecules capable of binding double-stranded telomeric DNA. This approach resulted in the purification of a 38 kDa polypeptide that was identified by mass spectrometry as Rbp38, a trypanosomatid protein previously shown to stabilize mitochondrial RNA and to associate with nuclear and kinetoplast DNAs. Western blotting and supershift assays confirmed the identity of the protein as LaRbp38. Competition and chromatin immunoprecipitation assays confirmed that LaRbp38 interacted with kinetoplast and nuclear DNAs in vivo and suggested that LaRbp38 may have dual cellular localization and more than one function

2007-07-06

35

Efficacy of components from leaves of Calophyllum brasiliense against Leishmania (Leishmania) amazonensis.  

Science.gov (United States)

Leishmanicide potential of Calophyllum brasiliense leaves on promastigote and amastigote of Leishmania (Leishmania) amazonensis is evaluated. The LD(50) of dichloromethane extract and hexane fraction for promastigotes was respectively 40 microg/ml and 20 microg/ml. In mouse peritoneal macrophages infected with Leishmania amastigotes the Infection Index decreased respectively 100% and 84.2% in 80 microg/ml and 40 microg/ml concentrations of dichloromethane extract. Hexane fraction decreased infection index respectively by 98.7% and 91.3% within the same concentrations. It was found that pretreatment with dichloromethane extract or with hexane fraction of experimentally infected BALB/c mice decrease the volume of the lesions by L. (L.) amazonensis. Moreover, animals treated topically also revealed healing lesions. Besides, the parasite load in the animals' popliteal lymph nodes was significantly reduced in treated animals, showing that plant components actually control infection. Results show that crude extract and hexane fraction of C. brasiliense reveal a significant in vitro and in vivo leishmanicide activity. PMID:19800777

Honda, P A; Ferreira, I C P; Cortez, D A G; Amado, C A B; Silveira, T G V; Brenzan, M A; Lonardoni, M V C

2009-10-02

36

Efficacy of components from leaves of Calophyllum brasiliense against Leishmania (Leishmania) amazonensis.  

UK PubMed Central (United Kingdom)

Leishmanicide potential of Calophyllum brasiliense leaves on promastigote and amastigote of Leishmania (Leishmania) amazonensis is evaluated. The LD(50) of dichloromethane extract and hexane fraction for promastigotes was respectively 40 microg/ml and 20 microg/ml. In mouse peritoneal macrophages infected with Leishmania amastigotes the Infection Index decreased respectively 100% and 84.2% in 80 microg/ml and 40 microg/ml concentrations of dichloromethane extract. Hexane fraction decreased infection index respectively by 98.7% and 91.3% within the same concentrations. It was found that pretreatment with dichloromethane extract or with hexane fraction of experimentally infected BALB/c mice decrease the volume of the lesions by L. (L.) amazonensis. Moreover, animals treated topically also revealed healing lesions. Besides, the parasite load in the animals' popliteal lymph nodes was significantly reduced in treated animals, showing that plant components actually control infection. Results show that crude extract and hexane fraction of C. brasiliense reveal a significant in vitro and in vivo leishmanicide activity.

Honda PA; Ferreira IC; Cortez DA; Amado CA; Silveira TG; Brenzan MA; Lonardoni MV

2010-04-01

37

The leishmanicidal flavonols quercetin and quercitrin target Leishmania (Leishmania) amazonensis arginase.  

UK PubMed Central (United Kingdom)

Polyamine biosynthesis enzymes are promising drug targets for the treatment of leishmaniasis, Chagas' disease and African sleeping sickness. Arginase, which is a metallohydrolase, is the first enzyme involved in polyamine biosynthesis and converts arginine into ornithine and urea. Ornithine is used in the polyamine pathway that is essential for cell proliferation and ROS detoxification by trypanothione. The flavonols quercetin and quercitrin have been described as antitrypanosomal and antileishmanial compounds, and their ability to inhibit arginase was tested in this work. We characterized the inhibition of recombinant arginase from Leishmania (Leishmania) amazonensis by quercetin, quercitrin and isoquercitrin. The IC(50) values for quercetin, quercitrin and isoquercitrin were estimated to be 3.8, 10 and 4.3 ?M, respectively. Quercetin is a mixed inhibitor, whereas quercitrin and isoquercitrin are uncompetitive inhibitors of L. (L.) amazonensis arginase. Quercetin interacts with the substrate l-arginine and the cofactor Mn(2+) at pH 9.6, whereas quercitrin and isoquercitrin do not interact with the enzyme's cofactor or substrate. Docking analysis of these flavonols suggests that the cathecol group of the three compounds interact with Asp129, which is involved in metal bridge formation for the cofactors Mn(A)(2+) and Mn(B)(2+) in the active site of arginase. These results help to elucidate the mechanism of action of leishmanicidal flavonols and offer new perspectives for drug design against Leishmania infection based on interactions between arginase and flavones.

da Silva ER; Maquiaveli Cdo C; Magalhães PP

2012-03-01

38

The leishmanicidal flavonols quercetin and quercitrin target Leishmania (Leishmania) amazonensis arginase.  

Science.gov (United States)

Polyamine biosynthesis enzymes are promising drug targets for the treatment of leishmaniasis, Chagas' disease and African sleeping sickness. Arginase, which is a metallohydrolase, is the first enzyme involved in polyamine biosynthesis and converts arginine into ornithine and urea. Ornithine is used in the polyamine pathway that is essential for cell proliferation and ROS detoxification by trypanothione. The flavonols quercetin and quercitrin have been described as antitrypanosomal and antileishmanial compounds, and their ability to inhibit arginase was tested in this work. We characterized the inhibition of recombinant arginase from Leishmania (Leishmania) amazonensis by quercetin, quercitrin and isoquercitrin. The IC(50) values for quercetin, quercitrin and isoquercitrin were estimated to be 3.8, 10 and 4.3 ?M, respectively. Quercetin is a mixed inhibitor, whereas quercitrin and isoquercitrin are uncompetitive inhibitors of L. (L.) amazonensis arginase. Quercetin interacts with the substrate l-arginine and the cofactor Mn(2+) at pH 9.6, whereas quercitrin and isoquercitrin do not interact with the enzyme's cofactor or substrate. Docking analysis of these flavonols suggests that the cathecol group of the three compounds interact with Asp129, which is involved in metal bridge formation for the cofactors Mn(A)(2+) and Mn(B)(2+) in the active site of arginase. These results help to elucidate the mechanism of action of leishmanicidal flavonols and offer new perspectives for drug design against Leishmania infection based on interactions between arginase and flavones. PMID:22327179

da Silva, Edson Roberto; Maquiaveli, Claudia do Carmo; Magalhães, Prislaine Pupolin

2012-02-01

39

Leishmania amazonensis fails to induce the release of reactive oxygen intermediates by CBA macrophages.  

Science.gov (United States)

CBA mouse macrophages effectively control Leishmania major infection, yet are permissive to Leishmania amazonensis. It has been established that some Leishmania species are destroyed by reactive oxygen species (ROS). However, other species of Leishmania exhibit resistance to ROS or even down-modulate ROS production. We hypothesized that L. amazonensis-infected macrophages reduce ROS production soon after parasite-cell interaction. Employing a highly sensitive analysis technique based on chemiluminescence, the production of superoxide (O(·-)(2)) and hydrogen peroxide (H(2)O(2)) by L. major- or L. amazonensis-infected CBA macrophages were measured. L. major induces macrophages to release levels of (O(·-)(2)) 3·5 times higher than in uninfected cells. This (O(·-)(2)) production is partially dependent on NADPH oxidase (NOX) type 2. The level of accumulated H(2)O(2) is 20 times higher in L. major-than in L. amazonensis-infected cells. Furthermore, macrophages stimulated with L. amazonensis release amounts of ROS similar to uninfected cells. These findings support previous studies showing that CBA macrophages are effective in controlling L. major infection by a mechanism dependent on both (O(·-)(2)) production and H(2)O(2) generation. Furthermore, these data reinforce the notion that L. amazonensis survive inside CBA macrophages by reducing ROS production during the phagocytic process. PMID:22817661

Almeida, T F; Palma, L C; Mendez, L C; Noronha-Dutra, A A; Veras, P S T

2012-10-01

40

Study of ionizing radiation as a tool for select promastigotes forms of Leishmania Amazonensis, and the megalomaniac response in experimental models; Estudo do uso da radiacao ionizante como ferramenta de selecao de formas promastigotas metaciclicas de Leishmania amazonensis, e a inducao de resposta imunologica em modelos experimentais  

Energy Technology Data Exchange (ETDEWEB)

Actually, millions of people around the globe are under the risk of infection by a protozoan transmitted by a bit of a sand fly. This parasite is a Leishmania spp. This causes a wide spectrum disease, since a cutaneous disease to a visceral one. The cutaneous form is the major clinical manifestation (above 90%). The ionizing radiation, produced in a {sup 60}Co font, had being successes used to promote physical-chemical transformations on different protozoan, including Leishmania spp. In previous work was determined that promastigotes forms of Leishmania amazonensis, irradiated with different doses of radiation, lost their viability maintaining, however, their immunogenicity. In this work, was studied the use of ionizing radiation as a tool for selection of meta cyclic forms of the parasite in axenic culture, for a possible efficient irradiated immuno gene production. Our results shown that cultures irradiated with 400 Gy of gamma irradiation, has 75% of metacyclic form, which are capable to produce, in vitro, an infection that is similar the natural occurrence. These irradiated parasites have their internal cellular structure modified, maintaining their external structure intact. Susceptible strain of mice immunized with leishmania irradiated with different doses had high immunoglobulin production, and maintained this production after the challenge with naive parasites. In other strains this default was similar, however in lower titles. Immunodeficient mice didn't produce immunoglobulin nor on the immunization or on the challenge. (author)

Bonetti, Franco Claudio

2006-07-01

 
 
 
 
41

Sand fly captures with Disney traps in area of occurrence of Leishmania (Leishmania) amazonensis in the state of Mato Grosso do Sul, mid-western Brazil/ Capturas de flebotomíneos com armadilhas de Disney em área de ocorrência de Leishmania (Leishmania) amazonensis no estado de Mato Grosso do Sul, região Centro-Oeste do Brasil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese INTRODUÇÃO: O estudo foi realizado com o objetivo de estudar a fauna de flebotomíneos (Diptera: Psychodidae) e aspectos ligados à transmissão da leishmaniose tegumentar americana em uma área florestal com ocorrência de Leishmania (Leishmania) amazonensis, situada no município de Bela Vista, Estado do Mato Grosso do Sul, Brasil. MÉTODOS: As capturas de flebotomíneos foram realizadas utilizando-se armadilhas tipo Disney modificadas, com isca roedor, Mesocricetus a (more) uratus, no período de maio de 2004 a janeiro de 2006. RESULTADOS: As coletas resultaram na identificação de 10 espécies de Phlebotominae: Brumptomyia avellari, Brumptomyia brumpti, Bichromomyia flaviscutellata, Evandromyia bourrouli, Evandromyia lenti, Lutzomyia longipalpis, Psathyromyia campograndensis, Psathyromyia punctigeniculata, Psathyromyia shannoni e Sciopemyia sordellii. As duas espécies predominantes foram Ev bourrouli, com 57,3% dos espécimes coletados, e Bi. flaviscutellata, representada por 41,4% e que esteve presente em todos os locais amostrados. Dois hamsters sentinelas adquiriram a infecção natural, sendo os isolados identificados como Leishmania amazonensis. CONCLUSÕES: Os resultados mostram a eficiência das armadilhas Disney para captura de Bichromomyia flaviscutellata, e a presença simultânea de ambos, o vetor e a espécie de Leishmania por ele transmitida pode ser considerada um fator preditor da ocorrência de leishmaniose para a população humana que permanecer nesse local. Abstract in english INTRODUCTION: The work was conducted to study phlebotomine fauna (Diptera: Psychodidae) and aspects of American cutaneous leishmaniasis transmission in a forested area where Leishmania (Leishmania) amazonensis occurs, situated in the municipality of Bela Vista, State of Mato Grosso do Sul, Brazil. METHODS: The captures were conducted with modified Disney traps, using hamster (Mesocricetus auratus) as bait, from May 2004 to January 2006. RESULTS: Ten species of phlebotomin (more) e sandflies were captured: Brumptomyia avellari, Brumptomyia brumpti, Bichromomyia flaviscutellata, Evandromyia bourrouli, Evandromyia lenti, Lutzomyia longipalpis, Psathyromyia campograndensis, Psathyromyia punctigeniculata, Psathyromyia shannoni and Sciopemyia sordellii. The two predominant species were Ev bourrouli (57.3%) and Bi flaviscutellata (41.4%), present at all sampling sites. Two of the 36 hamsters used as bait presented natural infection with Leishmania. The parasite was identified as Leishmania (Leishmania) amazonensis. CONCLUSIONS: Analysis of the results revealed the efficiency of Disney traps for capturing Bichromomyia flaviscutellata and the simultaneous presence of both vector and the Leishmania species transmitted by the same can be considered a predictive factor of the occurrence of leishmaniasis outbreaks for the human population that occupies the location.

Dorval, Maria Elizabeth Cavalheiros; Alves, Tulia Peixoto; Cristaldo, Geucira; Rocha, Hilda Carlos da; Alves, Murilo Andrade; Oshiro, Elisa Teruya; Oliveira, Alessandra Gutierrez de; Brazil, Reginaldo Peçanha; Galati, Eunice Aparecida Bianchi; Cunha, Rivaldo Venancio da

2010-10-01

42

Sand fly captures with Disney traps in area of occurrence of Leishmania (Leishmania) amazonensis in the state of Mato Grosso do Sul, mid-western Brazil Capturas de flebotomíneos com armadilhas de Disney em área de ocorrência de Leishmania (Leishmania) amazonensis no estado de Mato Grosso do Sul, região Centro-Oeste do Brasil  

Directory of Open Access Journals (Sweden)

Full Text Available INTRODUCTION: The work was conducted to study phlebotomine fauna (Diptera: Psychodidae) and aspects of American cutaneous leishmaniasis transmission in a forested area where Leishmania (Leishmania) amazonensis occurs, situated in the municipality of Bela Vista, State of Mato Grosso do Sul, Brazil. METHODS: The captures were conducted with modified Disney traps, using hamster (Mesocricetus auratus) as bait, from May 2004 to January 2006. RESULTS: Ten species of phlebotomine sandflies were captured: Brumptomyia avellari, Brumptomyia brumpti, Bichromomyia flaviscutellata, Evandromyia bourrouli, Evandromyia lenti, Lutzomyia longipalpis, Psathyromyia campograndensis, Psathyromyia punctigeniculata, Psathyromyia shannoni and Sciopemyia sordellii. The two predominant species were Ev bourrouli (57.3%) and Bi flaviscutellata (41.4%), present at all sampling sites. Two of the 36 hamsters used as bait presented natural infection with Leishmania. The parasite was identified as Leishmania (Leishmania) amazonensis. CONCLUSIONS: Analysis of the results revealed the efficiency of Disney traps for capturing Bichromomyia flaviscutellata and the simultaneous presence of both vector and the Leishmania species transmitted by the same can be considered a predictive factor of the occurrence of leishmaniasis outbreaks for the human population that occupies the location.INTRODUÇÃO: O estudo foi realizado com o objetivo de estudar a fauna de flebotomíneos (Diptera: Psychodidae) e aspectos ligados à transmissão da leishmaniose tegumentar americana em uma área florestal com ocorrência de Leishmania (Leishmania) amazonensis, situada no município de Bela Vista, Estado do Mato Grosso do Sul, Brasil. MÉTODOS: As capturas de flebotomíneos foram realizadas utilizando-se armadilhas tipo Disney modificadas, com isca roedor, Mesocricetus auratus, no período de maio de 2004 a janeiro de 2006. RESULTADOS: As coletas resultaram na identificação de 10 espécies de Phlebotominae: Brumptomyia avellari, Brumptomyia brumpti, Bichromomyia flaviscutellata, Evandromyia bourrouli, Evandromyia lenti, Lutzomyia longipalpis, Psathyromyia campograndensis, Psathyromyia punctigeniculata, Psathyromyia shannoni e Sciopemyia sordellii. As duas espécies predominantes foram Ev bourrouli, com 57,3% dos espécimes coletados, e Bi. flaviscutellata, representada por 41,4% e que esteve presente em todos os locais amostrados. Dois hamsters sentinelas adquiriram a infecção natural, sendo os isolados identificados como Leishmania amazonensis. CONCLUSÕES: Os resultados mostram a eficiência das armadilhas Disney para captura de Bichromomyia flaviscutellata, e a presença simultânea de ambos, o vetor e a espécie de Leishmania por ele transmitida pode ser considerada um fator preditor da ocorrência de leishmaniose para a população humana que permanecer nesse local.

Maria Elizabeth Cavalheiros Dorval; Tulia Peixoto Alves; Geucira Cristaldo; Hilda Carlos da Rocha; Murilo Andrade Alves; Elisa Teruya Oshiro; Alessandra Gutierrez de Oliveira; Reginaldo Peçanha Brazil; Eunice Aparecida Bianchi Galati; Rivaldo Venancio da Cunha

2010-01-01

43

Leishmania amazonensis exhibits phosphatidylserine-dependent procoagulant activity, a process that is counteracted by sandfly saliva  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Leishmania parasites expose phosphatidylserine (PS) on their surface, a process that has been associated with regulation of host's immune responses. In this study we demonstrate that PS exposure by metacyclic promastigotes of Leishmania amazonensis favours blood coagulation. L. amazonensis accelerates in vitro coagulation of human plasma. In addition, L. amazonensis supports the assembly of t (more) he prothrombinase complex, thus promoting thrombin formation. This process was reversed by annexin V which blocks PS binding sites. During blood meal, Lutzomyia longipalpis sandfly inject saliva in the bite site, which has a series of pharmacologically active compounds that inhibit blood coagulation. Since saliva and parasites are co-injected in the host during natural transmission, we evaluated the anticoagulant properties of sandfly saliva in counteracting the procoagulant activity of L. amazonensis . Lu. longipalpis saliva reverses plasma clotting promoted by promastigotes. It also inhibits thrombin formation by the prothrombinase complex assembled either in phosphatidylcholine (PC)/PS vesicles or in L. amazonensis . Sandfly saliva inhibits factor X activation by the intrinsic tenase complex assembled on PC/PS vesicles and blocks factor Xa catalytic activity. Altogether our results show that metacyclic promastigotes of L. amazonensis are procoagulant due to PS exposure. Notably, this effect is efficiently counteracted by sandfly saliva.

Rochael, Natalia Cadaxo; Lima, Luize Goncalves; Oliveira, Sandra Maria Pereira de; Barcinski, Marcello Andre; Saraiva, Elvira Maria; Monteiro, Robson Queiroz; Pinto-da-Silva, Lucia Helena

2013-09-01

44

Bioactivity of flavonoids isolated from Lychnophora markgravii against Leishmania amazonensis amastigotes.  

Science.gov (United States)

The bioactivity of the flavonoids pinostrobin (1), pinocembrin (2), tectochrysin (3), galangin 3-methyl ether (4), and tiliroside (5) isolated from Lychnophora markgravii aerial parts was investigated in vitro against amastigote stages of Leishmania amazonensis. The compounds were isolated by several chromatographic techniques and their chemical structures were established by ESI-MS and NMR spectroscopic data. The flavonoids 1 and 3 were the most active compounds; they markedly reduced the viability of Leishmania amastigotes. PMID:19791501

Salvador, Marcos José; Sartori, Fabiana Terezinha; Sacilotto, Ana Claudia B C; Pral, Elizabeth M F; Alfieri, Silvia Celina; Vichnewski, Walter

45

Bioactivity of flavonoids isolated from Lychnophora markgravii against Leishmania amazonensis amastigotes.  

UK PubMed Central (United Kingdom)

The bioactivity of the flavonoids pinostrobin (1), pinocembrin (2), tectochrysin (3), galangin 3-methyl ether (4), and tiliroside (5) isolated from Lychnophora markgravii aerial parts was investigated in vitro against amastigote stages of Leishmania amazonensis. The compounds were isolated by several chromatographic techniques and their chemical structures were established by ESI-MS and NMR spectroscopic data. The flavonoids 1 and 3 were the most active compounds; they markedly reduced the viability of Leishmania amastigotes.

Salvador MJ; Sartori FT; Sacilotto AC; Pral EM; Alfieri SC; Vichnewski W

2009-07-01

46

Combined effect of the essential oil from Chenopodium ambrosioides and antileishmanial drugs on promastigotes of Leishmania amazonensis Efeito combinado do óleo de essência de Chenopodium ambrosioides e drogas anti-leishmaniose nos promastigotas de Leishmania amazonensis  

Directory of Open Access Journals (Sweden)

Full Text Available 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.Até hoje não temos vacina contra a Leishmania e a quimioterapia é a indicação para o controle desta doença. Os remédios que hoje utilizamos são tóxicos e muito caros e além disso o resultado não é sempre o desejado. Por isso, uma terapia de combinação é a melhor opção. Este trabalho mostra que o óleo de essência de C. ambrosioides tem atividade sinérgica junto com a pentamidina sobre os promastigotas de L. amazonensis, diferente do resultado da combinação de antimônio de meglumine e anfotericina B e o óleo de essência.

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

2007-01-01

47

Mitochondrial damage contribute to epigallocatechin-3-gallate induced death in Leishmania amazonensis.  

UK PubMed Central (United Kingdom)

Epigallocatechin-3-gallate (EGCG), the most abundant flavonoid in green tea, has been reported to have antiproliferative effects on Trypanosoma cruzi however, the mechanism of protozoan action of EGCG has not been studied. In the present study, we demonstrate the mechanism for the antileishmanial activity of EGCG against Leishmania amazonensis promastigotes. Incubation with EGCG significantly inhibited L. amazonensis promastigote proliferation in a time- and dose-dependent manner. The IC(50) for EGCG at 120 h was 0.063 mM. Ultrastructural alterations of the mitochondria were observed in promastigote treated with EGCG, being the organelle injury reinforced by the decrease in rhodamine 123 fluorescence. The effects of several drugs that interfere directly with mitochondrial physiology in parasites such as Leishmania have been described. The unique mitochondrial features of Leishmania make this organelle an ideal drug target while minimizing toxicity. These data suggest mitochondrial collapse as a part of the EGCG mechanism of action and demonstrate the leishmanicidal effect of EGCG.

Inacio JD; Canto-Cavalheiro MM; Menna-Barreto RF; Almeida-Amaral EE

2012-10-01

48

Therapeutic trial in experimental tegumentary leishmaniasis caused by Leishmania (Leishmania) amazonensis. A comparative study between mefloquine and aminosidine Ensaio terapêutico na leishmaniose tegumentar experimental causada por Leishmania (Leishmania) amazonensis. Um estudo comparativo entre mefloquina e aminosidine  

Directory of Open Access Journals (Sweden)

Full Text Available One hundred and eighty-two male inbred C57/BL/6 mice were infected with 3 x 106 Leishmania (Leishmania) amazonensis promastigotes of the MHOM/BR/PH8 strain by means of a subcutaneous injection in the right ear. The animals were separated in three groups: 1) oral mefloquine hydrochloride treatment (16mg/kg/day/10 days), 2) intramuscular aminosidine (Paromomycin®) treatment (20mg/kg/20 days) and 3) control. Twenty six mice of each treated group were sacrificed, one at the end of treatment (nine weeks after inoculation), and one six weeks later (fifteen weeks after inoculation). Control Group animals were sacrificed at weeks six, nine and fifteen after inoculation. There was no significant difference between Group 1 (mefloquine) and Group 3 (control) subjects. Group 2 animals (aminosidine) presented the smallest differences of all, both at the end of the treatment and six weeks later. The histopato-logical parameters have shown the following findings: a) there was no significant difference between the mefloquine treated group and the control group; the group treated with aminosidine showed fewer of vacuolated macrophages than the control group, at week 9 (end of treatment). b) both at the end of treatment and six weeks later, evaluation of tissue necrosis and tissue fibrosis revealed no differences between the treated groups. It was found that six weeks after the end of treatment, mice in the control group presented significantly more severe degrees of fibrosis than mice in the other groups. It can be concluded that mefloquine showed limited therapeutic effect in this experimental model, whereas aminosidine had a significant effect. Nevertheless, neither of them resulted in cure of the lesions.Foram utilizados 182 camundongos machos, isogênicos, da linhagem C57BL/6 inoculados na orelha direita com 3,0 x 10(6) formas promastigotas da cepa MHOM/BR/PH8 de Leishmania (Leishmania) amazonensis. Os animais foram separados em três grupos: 1) 52 animais tratados com mefloquina (16mg/kg/dia/10 dias), 2) 52 animais tratados com aminosidina [Paramomicina ®] (20mg/kg/dia/20 dias), 3) 78 animais controles, não manipulados. Vinte e seis animais de cada grupo tratado foram sacrificados nove e quinze semanas após a inoculação. Animais do grupo controle foram sacrificados na sexta, nona e décima quinta semanas após a inoculação. Ao final do tratamento, em relação à curva de peso da orelhas, somente nos animais tratados com aminosidina, houve nítida redução do peso em comparação com grupo controle. Na histopatologia verificou-se: a) não houve diferença entre o grupo tratado com mefloquina e o grupo controle; o grupo tratado com aminosidina, ao final do tratamento, teve menor infiltração por macrófagos vacuolizados; b) as avaliações da extensão das áreas de necrose e do nível da fibrose tecidual não mostraram diferenças entre os grupos tratados. Os animais do grupo controle apresentaram fibrose mais acentuada, seis semanas após o fim do tratamento. Pode-se concluir que ocorreu efeito terapêutico reduzido com a mefloquina e houve significativa melhora com a aminosidina. Entretanto, em todos os grupos as lesões não chegaram a curar.

Letícia Oba Galvão; Sebastião Moreira Júnior; Pedro Medeiros Júnior; Gleiser José Piantino Lemos; Nara Fabiana Cunha; Rosa Maria Parreiras Antonino; Bráulio Silva Santos Filho; Albino Verçosa Magalhães

2000-01-01

49

Photodynamic Sensitization of Leishmania amazonensis in both Extracellular and Intracellular Stages with Aluminum Phthalocyanine Chloride for Photolysis In Vitro  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Leishmania amazonensis, a causative agent of cutaneous leishmaniasis, is susceptible in vitro to light-mediated cytolysis in the presence of or after pretreatment with the photosensitizer aluminum phthalocyanine chloride. Cytolysis of both promastigotes and axenic amastigotes required less photosens...

Dutta, Sujoy; Ray, Debalina; Kolli, Bala K.; Chang, Kwang-Poo

50

The T-cell anergy induced by Leishmania amazonensis antigens is related with defective antigen presentation and apoptosis  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A Leishmania amazonensis é o principal agente etiológico da leishmaniose cutânea difusa, uma doença associada a respostas imunes anérgicas. Neste estudo nós mostramos que o extrato bruto de promastigotas de Leishmania amazonensis (LaAg), mas não de L. braziliensis (LbAg), contém substâncias que suprimem respostas proliferativas, espontâneas e mitogênicas, de células T. As substâncias supressoras no LaAg são termo-resistentes (100°C/1h) e parcialmente depend (more) entes da atividade de proteases. A anergia de células T não foi devida à diminuição na produção de fatores de crescimento, uma vez que não foi revertida pela adição de: IL-2, IL-4, IFN-gama ou IL-12. O LaAg não inibiu a ativação de células T induzida por anti-CD3, sugerindo que a anergia é devida a um defeito na apresentação de antígenos. A anergia não foi devida à necrose celular, mas foi acompanhada de uma expressiva fragmentação de DNA nas células de linfonodos, indicativo de apoptose. Apesar da pré-incubação de macrófagos com LaAg ter inibido sua capacidade de apresentação de antigenos, este efeito não foi devido à apoptose dos primeiros. Estes resultados sugerem que a anergia de células T encontrada na leishmaniose difusa deve ser devida à apoptose dessas células que se segue à apresentação defeituosa de antígenos pelo antígeno do parasito. Abstract in english Leishmania amazonensis is the main agent of diffuse cutaneous leishmaniasis, a disease associated with anergic immune responses. In this study we show that the crude antigen of Leishmania amazonensis (LaAg) but not L. braziliensis promastigotes (LbAg) contains substances that suppress mitogenic and spontaneous proliferative responses of T cells. The suppressive substances in LaAg are thermoresistant (100ºC/1h) and partially dependent on protease activity. T cell anergy w (more) as not due to a decreased production of growth factors as it was not reverted by addition of exogenous IL-2, IL-4, IFN-gamma or IL-12. LaAg did not inhibit anti-CD3-induced T cell activation, suggesting that anergy was due to a defect in antigen presentation. It was also not due to cell necrosis, but was accompanied by expressive DNA fragmentation in lymph node cells, indicative of apoptosis. Although pre-incubation of macrophages with LaAg prevented their capacity to present antigens, this effect was not due to apoptosis of the former. These results suggest that the T cell anergy found in diffuse leishmaniasis may be the result of parasite antigen-driven apoptosis of those cells following defective antigen presentation.

Pinheiro, Roberta O.; Pinto, Eduardo F.; Benedito, Alessandra B.; Lopes, Ulisses G.; Rossi-Bergmann, Bartira

2004-09-01

51

Immune responses induced by a Leishmania (Leishmania) amazonensis recombinant antigen in mice and lymphocytes from vaccinated subjects  

Directory of Open Access Journals (Sweden)

Full Text Available In the search for Leishmania recombinant antigens that can be used as a vaccine against American Cutaneous Leishmaniasis, we identified a Leishmania (Leishmania) amazonensis recombinant protein of 33 kD (Larp33) which is recognized by antibodies and peripheral blood leukocytes (PBL) from subjects vaccinated with Leishvacin ®, Larp33 was expressed in Escherichia coli after cloning of a 2,2 kb Sau3A digested genomic fragment of L. (L.) amazonensis into the pDS56-6 His vector. Immunoblotting analysis indicated that Larp33 corresponds to an approximately 40-kD native protein expressed in promastigotes of L.(L.) amazonensis and L. (Viannia) braziliensis. Northern blots of total RNA also demonstrated that the gene coding for this protein is expressed in promastigotes of the major lineages of Leishmania causing American Cutaneous Leishmaniasis. Larp33 induced partial protection in susceptible mouse strains (BALB/c and C57BL/10) against L. (L.) amazonensis after vaccination using Bacille Calmette-Guerin (BCG) as adjuvant. In vitro stimulation of splenocytes from BALB/c protected mice with Larp33 elicited the secretion of IL-2 and IFN-g, suggesting that a Th1 cell-mediated protective response is associated with the resistance observed in these mice. As revealed by its immunogenic and antigenic properties, this novel recombinant antigen is a suitable candidate to compose a vaccine against cutaneous leishmaniasisA resposta imune induzida por uma proteína recombinante de Leishmania (Leishmania) amazonensis de 33 kD (Larp33) foi avaliada em linfócitos de indivíduos vacinados com a Leishvacin® e em camundongos através de vacinação. Larp33 foi expressa em Escherichia coli após clonagem de um fragmento genômico de L. (L.) amazonensis de 2,2 kb no vetor pDS56-6His. Larp33 foi reconhecida por anticorpos IgG presentes no soro de indivíduos vacinados com Leishvacin® e induziu proliferação em linfócitos desses indivíduos em níveis comparáveis ao antígeno total de Leishmania. A análise por imunoblot indicou que Larp33 corresponde a uma proteína de aproximadamente 40 kD expressa em promastigotas de L. (L.) amazonensis e L. (Viannia) braziliensis. Hibridização com sonda de DNA correspondente a parte do fragmento clonado, também demonstrou que o gene codificador desta proteína é expresso em promastigotas destas duas espécies. Larp33 em associação com BCG (Bacille Calmette-Guerin) foi capaz de induzir 75% de proteção em camundongos C75BL/10 e BALB/c, suceptíveis à infecção por L. (L.) amazonensis. Linfócitos dos camundongos protegidos produziram IL-2 e IFN-g em resposta a Larp33. Nossos resultados indicam que Larp33 é imunogênica para linfócitos de indivíduos vacinados com Leishvacin ® e protetora para camundongos contra a infecção por L. (L.) amazonensis

Ana Paula FERNANDES; Elizabeth Cortez HERRERA; Wilson MAYRINK; Ricardo T. GAZZINELLI; Wen Yu LIU; Carlos Alberto da COSTA; Carlos Alberto Pereira TAVARES; Maria Norma MELO; Marilene Susan Marques MICHALICK; Reiner GENTZ; Evaldo NASCIMENTO

1997-01-01

52

Correlation of meta 1 expression with culture stage, cell morphology and infectivity in Leishmania (Leishmania) amazonensis promastigotes  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The parasitic protozoan Leishmania (Leishmania) amazonensis alternates between mammalian and insect hosts. In the insect host, the parasites proliferate as procyclic promastigotes andthen differentiate into metacyclic infective forms. The meta 1 gene is preferentially expressed during metacyclogenesis. Meta 1 expression profile determination along parasite growth curves revealed that the meta 1 mRNA level peaked at the early stationary phase then decreased to an intermedi (more) ate level. No correlation was observed between meta 1 expression and infectivity. Conversely, infectivity correlated with the increase of apoptotic cells in the late stationary phase.

Santos, Marcos Gonzaga dos; Silva, Maria Fernanda Laranjeira da; Zampieri, Ricardo Andrade; Lafraia, Rafaella Marino; Floeter-Winter, Lucile Maria

2011-03-01

53

Reactive Oxygen Species Production by Quercetin Causes the Death of Leishmania amazonensis Intracellular Amastigotes.  

UK PubMed Central (United Kingdom)

The present study reports the mechanism of the antileishmanial activity of quercetin (1) against the intracellular amastigote form of Leishmania amazonensis. Treatment with 1 reduced the infection index in L. amazonensis-infected macrophages in a dose-dependent manner, with an IC50 value of 3.4 ?M and a selectivity index of 16.8, and additionally increased ROS generation also in a dose-dependent manner. Quercetin (1) has been described as a pro-oxidant that induces the production of reactive oxygen species, which can cause cell death. Taken together, these results suggest that ROS production plays a role in the mechanism of action of 1 in the control of intracellular amastigotes of L. amazonensis.

Fonseca-Silva F; Inacio JD; Canto-Cavalheiro MM; Almeida-Amaral EE

2013-08-01

54

Effect of hydroxyurea on the intracellular multiplication of Toxoplasma gondii, Leishmania amazonensis and Trypanosoma cruzi  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Toxoplasma gondii, Leishmania amazonensis and Trypanosoma cruzi are obligate intracellular parasites that multiply until lysis of host cells. The present study was undertaken to evaluate the effect of hydroxyurea (an inhibitor of cell division at the G1/S phase) on the multiplication of L. amazonensis, T. gondii, and T. cruzi in infected host cells. Infected cells were treated with hydroxyurea (4 mM) for 48 h. Hydroxyurea arrested intracellular multiplication of all infec (more) tive forms of the parasites tested. In treated cultures, the percent of infected host cells decreased (50-97%) and most intracellular parasites were eliminated. Ultrastructural observations showed no morphologic change in host cells while intracellular parasites presented drastic morphologic alterations or disruption. The results strongly suggest that hydroxyurea was able to interfere with the multiplication of intracellular parasites, leading to an irreversible morphological effect on L. amazonensis, T. gondii, and T. cruzi without affecting the host cells.

Melo, E.J.T.; Beiral, H.J.

2003-01-01

55

Protection of C57BL/10 mice by vaccination with association of purified proteins from Leishmania (Leishmania) amazonensis Proteção de camundongos C57BL/10 vacinados por vacinas contituidas pelas combinações de proteínas purificadas de Leishmania (Leishmania) amazonensis  

Directory of Open Access Journals (Sweden)

Full Text Available In the past few years, induction of protective immunity to cutaneous leishmaniasis has been attempted by many researchers using a variety of antigenic preparations, such as living promastigotes or promastigote extracts, partially purified, or defined proteins. In this study, eleven proteins from Leishmania (Leishmania) amazonensis (LLa) with estimated molecular mass ranging from 97 to 13.5kDa were isolated by polyacrylamide gel electrophoresis and electro-elution. The proteins were associated as vaccine in different preparations with gp63 and BCG (Bacilli Calmette-Guérin). The antigenicity of these vaccines was measured by their ability to induce the production of IFN-g by lymphocyte from subjects vaccinated with Leishvacinâ . The immunogenicity was evaluated in vaccinated mice. C57BL/10 mice were vaccinated with three doses of each vaccine consisting of 30 mg of each protein at 15 days interval. One hundred mg of live BCG was only used in the first dose. Seven days after the last dose, they received a first challenge infection with 105 infective promastigotes and four months later, a second challenge was done. Two months after the second challenge, 42.86% of protection was obtained in the group of mice vaccinated with association of proteins of gp63+46+22kDa, gp63+13.5+25+42kDa, gp63+46+42kDa, gp63+66kDa, and gp63+97kDa; 57.14% of protection was demonstrated with gp63+46+97+13.5kDa, gp63+46+97kDa, gp63+46+33kDa, and 71.43% protection for gp63 plus all proteins. The vaccine of gp63+46+40kDa that did not protect the mice, despite the good specific stimulation of lymphocytes (LSI = 7.60) and 10.77UI/ml of IFN-g production. When crude extract of L. (L.) amazonensis was used with BCG a 57.14% of protection was found after the first challenge and 28.57% after the second, the same result was observed for gp63. The data obtained with the vaccines can suggest that the future vaccine probably have to contain, except the 40kDa, a cocktail of proteins that would protect mice against cutaneous leishmaniasis.A indução de imunidade no homem contra a leishmaniose cutânea tem sido estudada por vários pesquisadores usando uma grande variedade de preparações antigênicas, como: promastigotas vivas ou atenuadas, extratos de promastigotas, antígenos parcialmente purificados e proteínas puras. Neste trabalho foram isoladas 11 proteínas de L. (L.) amazonensis com pesos moleculares variando de 13.5 a 97 kDa por eletroforese em gel de poliacrilamida e por eletroeluição. Estas proteínas foram combinadas em diferentes preparações vacinais com gp63 e BCG. As vacinas foram avaliadas in vitro quanto à capacidade de estimular linfócitos de pessoas vacinadas com Leishvacinâ a produzirem IFN-g e a estimularem a proliferação de linfócitos de camundongos vacinados. Assim, camundongos C57BL/10 foram vacinados em intervalos de 15 dias com três doses de cada vacina contendo 30 mg de cada proteína. 100 mg de BCG foram usados somente na primeira dose. Sete dias após a última dose os animais receberam a primeira infecção desafiado com 105 promastigotas infectantes e um segundo desafio foi administrado 143 dias após, com o mesmo número de parasitas. Sessenta dias após o segundo desafio, proteções de 42,86% foram obtidas com as vacinas constituídas de gp63+46+22kDa, gp63+13.5+25+42kDa, gp63+46+42kDa, gp63+66kDa e gp63+97kDa; 57,14% de proteção foi obtido com a vacina gp63+46+97kDa, gp63+46+97+13.5kDa, gp63+46+33kDa, e 71,43% com a vacina constituída de gp63 mais todas as proteínas. Em contraste, a vacina gp63+46+33kDa não induziu proteção nos camundongos vacinados, indicando que possivelmente a proteína de 40kDa induziu a uma atividade imunossupressora da resposta imunoprotetora. Estes resultados sugerem que uma futura vacina contra a leishmaniose cutânea deverá conter, excluindo-se a proteína de 40kDa, um coquetel de proteínas imunogênicas indutoras de proteção de camundongos contra a leishmaniose cutânea.

Ana Mariela MORA; Wilson MAYRINK; Roberto Teodoro da COSTA; Carlos Alberto da COSTA; Odair GENARO; Evaldo NASCIMENTO

1999-01-01

56

Dietary flavonoids fisetin, luteolin and their derived compounds inhibit arginase, a central enzyme in Leishmania (Leishmania) amazonensis infection.  

Science.gov (United States)

Fisetin, quercetin, luteolin and 7,8-hydroxyflavone show high activity in Leishmania cultures and present low toxicity to mammalian cells. In this work, the structural aspects of 13 flavonoids were analyzed for their inhibition of the arginase enzyme from Leishmania (Leishmania) amazonensis. A higher potency of arginase inhibition was observed with fisetin, which was four and ten times greater than that of quercetin and luteolin, respectively. These data show that the hydroxyl group at position 3 contributed significantly to the inhibitory activity of arginase, while the hydroxyl group at position 5 did not. The absence of the catechol group on apigenin drastically decreased arginase inhibition. Additionally, the docking of compounds showed that the inhibitors interact with amino acids involved in the Mn(+2)-Mn(+2) metal bridge formation at the catalytic site. Due to the low IC50 values of these flavonoids, they may be used as a food supplement in leishmaniasis treatment. PMID:23870955

Manjolin, Leticia Correa; dos Reis, Matheus Balduíno Goncalves; Maquiaveli, Claudia do Carmo; Santos-Filho, Osvaldo Andrade; da Silva, Edson Roberto

2013-05-18

57

Dietary flavonoids fisetin, luteolin and their derived compounds inhibit arginase, a central enzyme in Leishmania (Leishmania) amazonensis infection.  

UK PubMed Central (United Kingdom)

Fisetin, quercetin, luteolin and 7,8-hydroxyflavone show high activity in Leishmania cultures and present low toxicity to mammalian cells. In this work, the structural aspects of 13 flavonoids were analyzed for their inhibition of the arginase enzyme from Leishmania (Leishmania) amazonensis. A higher potency of arginase inhibition was observed with fisetin, which was four and ten times greater than that of quercetin and luteolin, respectively. These data show that the hydroxyl group at position 3 contributed significantly to the inhibitory activity of arginase, while the hydroxyl group at position 5 did not. The absence of the catechol group on apigenin drastically decreased arginase inhibition. Additionally, the docking of compounds showed that the inhibitors interact with amino acids involved in the Mn(+2)-Mn(+2) metal bridge formation at the catalytic site. Due to the low IC50 values of these flavonoids, they may be used as a food supplement in leishmaniasis treatment.

Manjolin LC; dos Reis MB; Maquiaveli Cdo C; Santos-Filho OA; da Silva ER

2013-12-01

58

Leishmania amazonensis: Biological and biochemical characterization of ecto-nucleoside triphosphate diphosphohydrolase activities.  

Science.gov (United States)

The presence of Leishmania amazonensis ecto-nucleoside triphosphate triphosphohydrolase activities was demonstrated using antibodies against different NTPDase members by Western blotting, flow cytometry, and immunoelectron microscopy analysis. Living promastigote cells sequentially hydrolyzed the ATP molecule generating ADP, AMP, and adenosine, indicating that this surface enzyme may play a role in the salvage of purines from the extracellular medium. The L. amazonensis ecto-NTPDase activities were insensitive to Triton X-100, but they were enhanced by divalent cations, such as Mg(2+). In addition, the ecto-NTPDase activities decreased with time for 96 h when promastigotes were grown in vitro. On the other hand, these activities increased considerably when measured in living amastigote forms. Furthermore, the treatment with adenosine, a mediator of several relevant biological phenomena, induced a decrease in the reactivity with anti-CD39 antibody, raised against mammalian E-NTPDase, probably because of down regulation in the L. amazonensis ecto-NTPDase expression. Also, adenosine and anti-NTPDase antibodies induced a significant diminishing in the interaction between promastigotes of L. amazonensis and mouse peritoneal macrophages. PMID:16603157

Pinheiro, Carla M; Martins-Duarte, Erica S; Ferraro, Rodrigo B; Fonseca de Souza, André Luíz; Gomes, Marta T; Lopes, Angela H C S; Vannier-Santos, Marcos A; Santos, André L S; Meyer-Fernandes, José R

2006-04-17

59

Kinetoplastid membrane protein-11 exacerbates infection with Leishmania amazonensis in murine macrophages  

Directory of Open Access Journals (Sweden)

Full Text Available In Leishmania amazonensis, kinetoplastid membrane protein-11 (KMP-11) expression increases during metacyclogenesis and is higher in amastigotes than in promastigotes, suggesting a role for this protein in the infection of the mammalian host. We show that the addition of KMP-11 exacerbates L. amazonensis infection in peritoneal macrophages from BALB/c mice by increasing interleukin (IL)-10 secretion and arginase activity while reducing nitric oxide (NO) production. The doses of KMP-11, the IL-10 levels and the intracellular amastigote loads were strongly, positively and significantly correlated. The increase in parasite load induced by KMP-11 was inhibited by anti-KMP-11 or anti-IL-10 neutralising antibodies, but not by isotype controls. The neutralising antibodies, but not the isotype controls, were also able to significantly decrease the parasite load in macrophages cultured without the addition of KMP-11, demonstrating that KMP-11-induced exacerbation of the infection is not dependent on the addition of exogenous KMP-11 and that the protein naturally expressed by the parasite is able to promote it. In this study, the exacerbating effect of KMP-11 on macrophage infection with Leishmania is for the first time demonstrated, implicating it as a virulence factor in L. amazonensis. The stimulation of IL-10 production and arginase activity and the inhibition of NO synthesis are likely involved in this effect.

Daniel Ignacchiti Lacerda; Léa Cysne-Finkelstein; Marise Pinheiro Nunes; Paula Mello De-Luca; Marcelo da Silva Genestra; Leonor Laura Pinto Leon; Marcia Berrêdo-Pinho; Leila Mendonça-Lima; Denise Cristina de Souza Matos; Marco Alberto Medeiros; Sergio Coutinho Furtado de Mendonça

2012-01-01

60

Kinetoplastid membrane protein-11 exacerbates infection with Leishmania amazonensis in murine macrophages  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english In Leishmania amazonensis, kinetoplastid membrane protein-11 (KMP-11) expression increases during metacyclogenesis and is higher in amastigotes than in promastigotes, suggesting a role for this protein in the infection of the mammalian host. We show that the addition of KMP-11 exacerbates L. amazonensis infection in peritoneal macrophages from BALB/c mice by increasing interleukin (IL)-10 secretion and arginase activity while reducing nitric oxide (NO) production. The dos (more) es of KMP-11, the IL-10 levels and the intracellular amastigote loads were strongly, positively and significantly correlated. The increase in parasite load induced by KMP-11 was inhibited by anti-KMP-11 or anti-IL-10 neutralising antibodies, but not by isotype controls. The neutralising antibodies, but not the isotype controls, were also able to significantly decrease the parasite load in macrophages cultured without the addition of KMP-11, demonstrating that KMP-11-induced exacerbation of the infection is not dependent on the addition of exogenous KMP-11 and that the protein naturally expressed by the parasite is able to promote it. In this study, the exacerbating effect of KMP-11 on macrophage infection with Leishmania is for the first time demonstrated, implicating it as a virulence factor in L. amazonensis. The stimulation of IL-10 production and arginase activity and the inhibition of NO synthesis are likely involved in this effect.

Lacerda, Daniel Ignacchiti; Cysne-Finkelstein, Léa; Nunes, Marise Pinheiro; De-Luca, Paula Mello; Genestra, Marcelo da Silva; Leon, Leonor Laura Pinto; Berrêdo-Pinho, Marcia; Mendonça-Lima, Leila; Matos, Denise Cristina de Souza; Medeiros, Marco Alberto; Mendonça, Sergio Coutinho Furtado de

2012-03-01

 
 
 
 
61

Mitochondrial damage contribute to epigallocatechin-3-gallate induced death in Leishmania amazonensis.  

Science.gov (United States)

Epigallocatechin-3-gallate (EGCG), the most abundant flavonoid in green tea, has been reported to have antiproliferative effects on Trypanosoma cruzi however, the mechanism of protozoan action of EGCG has not been studied. In the present study, we demonstrate the mechanism for the antileishmanial activity of EGCG against Leishmania amazonensis promastigotes. Incubation with EGCG significantly inhibited L. amazonensis promastigote proliferation in a time- and dose-dependent manner. The IC(50) for EGCG at 120 h was 0.063 mM. Ultrastructural alterations of the mitochondria were observed in promastigote treated with EGCG, being the organelle injury reinforced by the decrease in rhodamine 123 fluorescence. The effects of several drugs that interfere directly with mitochondrial physiology in parasites such as Leishmania have been described. The unique mitochondrial features of Leishmania make this organelle an ideal drug target while minimizing toxicity. These data suggest mitochondrial collapse as a part of the EGCG mechanism of action and demonstrate the leishmanicidal effect of EGCG. PMID:22735546

Inacio, Job D F; Canto-Cavalheiro, Marilene M; Menna-Barreto, Rubem F S; Almeida-Amaral, Elmo E

2012-06-23

62

Reprogramming neutral lipid metabolism in mouse dendritic leucocytes hosting live Leishmania amazonensis amastigotes.  

UK PubMed Central (United Kingdom)

BACKGROUND: After loading with live Leishmania (L) amazonensis amastigotes, mouse myeloid dendritic leucocytes/DLs are known to undergo reprogramming of their immune functions. In the study reported here, we investigated whether the presence of live L. amazonensis amastigotes in mouse bone marrow-derived DLs is able to trigger re-programming of DL lipid, and particularly neutral lipid metabolism. METHODOLOGY/PRINCIPAL FINDINGS: Affymetrix-based transcriptional profiles were determined in C57BL/6 and DBA/2 mouse bone marrow-derived DLs that had been sorted from cultures exposed or not to live L. amazonensis amastigotes. This showed that live amastigote-hosting DLs exhibited a coordinated increase in: (i) long-chain fatty acids (LCFA) and cholesterol uptake/transport, (ii) LCFA and cholesterol (re)-esterification to triacyl-sn-glycerol (TAG) and cholesteryl esters (CE), respectively. As these neutral lipids are known to make up the lipid body (LB) core, oleic acid was added to DL cultures and LB accumulation was compared in live amastigote-hosting versus amastigote-free DLs by epi-fluorescence and transmission electron microscopy. This showed that LBs were both significantly larger and more numerous in live amastigote-hosting mouse dendritic leucocytes. Moreover, many of the larger LB showed intimate contact with the membrane of the parasitophorous vacuoles hosting the live L. amazonensis amastigotes. CONCLUSIONS/SIGNIFICANCE: As leucocyte LBs are known to be more than simple neutral lipid repositories, we set about addressing two related questions. Could LBs provide lipids to live amastigotes hosted within the DL parasitophorous vacuole and also deliver? Could LBs impact either directly or indirectly on the persistence of L. amazonensis amastigotes in rodent skin?

Lecoeur H; Giraud E; Prévost MC; Milon G; Lang T

2013-06-01

63

Technetium-99m labeling anti-amastigote polyclonal antibodies of Leishmania amazonensis  

Energy Technology Data Exchange (ETDEWEB)

Anti-amastigote polyclonal antibody (IgG) was incubated with solutions of stannous chloride and sodium borohidride. After that, 3.7 MBq of technetium-99m ({sup 99m}Tc) was added. A labeling yield of the antibody about 84% was obtained. After filtration of {sup 99m}Tc-IgG, the radiochemical purity increased from 84 to 95%. The labeling of IgG with {sup 99m}Tc did not modify the immunoreactivity of the antibody, since it was able to identify in vitro and in vivo the specific antigen of Leishmania amazonensis.

Araujo, J.G.V.C.; Toledo, V.P.C.P.; Guimaraes, T.M.P.D.; Bernardo-Filho, M.; Simal, C.J.R.; Mota, L.G.; Diniz, S.O.F.; Cardoso, V.N. E-mail: cardosov@farmacia.ufmg.br

2002-05-01

64

Experimental infection with Leishmania (Viannia) braziliensis, and Leishmania (Leishmania) amazonensis in the marmoset, Callithrix penicillata (Primates: Callithricidae)  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Foureen marmosets (Callithrix penicillata) were inoculated intradermally with promastigotes and/or amastigotes of Leishmania (Viannia) brazilensis (L. (V) b.) strains MHOM/BR/83/LTB-300MHOM/BR/85/LTB-12 MHOM/BR/81/LTB-179 and MHOM/BR/82/LTB-250. The evolution of subsequent lesions was studied for 15 to 75 weeks post-inoculation (PI). All but of the L. (V) b. injected marmosets developed a cutaneous lesion at the point of inoculation after 3 to 9 weeks, characterized by th (more) e appearance of subcutaneous nodules containing parasites. parasites were isolated by culture (Difco Blood Agar) from all 11 positive animals. The maximum size of the lesions was variable and ranged between 37 mm² to 107 mm². Ulceration of primary nodules became evident after 3 to 12 weeks in all infected marmosets, but was faster and larger in 5 of the 11 animals. The active lesions persisted in 9 out of 11 Callithrix until the en of the observation period, which varied from 15-75 weeks. In 3 animals spontaneous healing of their lesions (13 to 25 weeks, PI) was observed buth with cryptic parasitism. In another 2 infected animals there was regression followed by reactivation of the cutaneous lesions. The appearance of smaller satellite lesions adjacent to primary ones, as well as metastatic lesions to the ear lobes, were documented in 2 animals. Promastigotes of L. (Leishmania) amazonensis (L.(L)a.) MHOM/BR/77/LTB-16 were inoculated in 1 marmoset. This animal remained chronically infected for 6 months and the lesions developed in a similar manner to L.(V)b. infected marmosets. No significant differences in clinical and parasitological behaviour were observed between promastigote or amastigote derived infections of the 2 species. Both produced chronic, long lasting lesions which eventually healed. The same was true for parameters of size and ulceration. Skin tests converted to parasite in 11 of 15 inected masmosets and in 10 of 12 parasite positive animnals. Moderate levels of circulating antibodies were also observed by IFAT /IgG assays. In spite of the failure to reproduce the mucosal form of the disease, an important aspect of the Callithrix model in experimental cutaneous leishmaniasis lies in the reproduction of 2 clinical events that are common in humans, namely, the chronic ulceration and spontaneous healing of the lesions.

Cuba, César A. Cuba; Ferreira, Vera; Bampi, Maria; Magalhães, Albino; Marsden, Philip D.; Vexenat, Alejandro; Mello, Milton Thiago de

1990-12-01

65

Experimental infection with Leishmania (Viannia) braziliensis, and Leishmania (Leishmania) amazonensis in the marmoset, Callithrix penicillata (Primates: Callithricidae)  

Directory of Open Access Journals (Sweden)

Full Text Available Foureen marmosets (Callithrix penicillata) were inoculated intradermally with promastigotes and/or amastigotes of Leishmania (Viannia) brazilensis (L. (V) b.) strains MHOM/BR/83/LTB-300MHOM/BR/85/LTB-12 MHOM/BR/81/LTB-179 and MHOM/BR/82/LTB-250. The evolution of subsequent lesions was studied for 15 to 75 weeks post-inoculation (PI). All but of the L. (V) b. injected marmosets developed a cutaneous lesion at the point of inoculation after 3 to 9 weeks, characterized by the appearance of subcutaneous nodules containing parasites. parasites were isolated by culture (Difco Blood Agar) from all 11 positive animals. The maximum size of the lesions was variable and ranged between 37 mm² to 107 mm². Ulceration of primary nodules became evident after 3 to 12 weeks in all infected marmosets, but was faster and larger in 5 of the 11 animals. The active lesions persisted in 9 out of 11 Callithrix until the en of the observation period, which varied from 15-75 weeks. In 3 animals spontaneous healing of their lesions (13 to 25 weeks, PI) was observed buth with cryptic parasitism. In another 2 infected animals there was regression followed by reactivation of the cutaneous lesions. The appearance of smaller satellite lesions adjacent to primary ones, as well as metastatic lesions to the ear lobes, were documented in 2 animals. Promastigotes of L. (Leishmania) amazonensis (L.(L)a.) MHOM/BR/77/LTB-16 were inoculated in 1 marmoset. This animal remained chronically infected for 6 months and the lesions developed in a similar manner to L.(V)b. infected marmosets. No significant differences in clinical and parasitological behaviour were observed between promastigote or amastigote derived infections of the 2 species. Both produced chronic, long lasting lesions which eventually healed. The same was true for parameters of size and ulceration. Skin tests converted to parasite in 11 of 15 inected masmosets and in 10 of 12 parasite positive animnals. Moderate levels of circulating antibodies were also observed by IFAT /IgG assays. In spite of the failure to reproduce the mucosal form of the disease, an important aspect of the Callithrix model in experimental cutaneous leishmaniasis lies in the reproduction of 2 clinical events that are common in humans, namely, the chronic ulceration and spontaneous healing of the lesions.

César A. Cuba Cuba; Vera Ferreira; Maria Bampi; Albino Magalhães; Philip D. Marsden; Alejandro Vexenat; Milton Thiago de Mello

1990-01-01

66

Benzaldehyde Thiosemicarbazone Derived from Limonene Complexed with Copper Induced Mitochondrial Dysfunction in Leishmania amazonensis  

Science.gov (United States)

Background Leishmaniasis is a major health problem that affects more than 12 million people. Treatment presents several problems, including high toxicity and many adverse effects, leading to the discontinuation of treatment and emergence of resistant strains. Methodology/Principal Findings We evaluated the in vitro antileishmanial activity of benzaldehyde thiosemicarbazone derived from limonene complexed with copper, termed BenzCo, against Leishmania amazonensis. BenzCo inhibited the growth of the promastigote and axenic amastigote forms, with IC50 concentrations of 3.8 and 9.5 µM, respectively, with 72 h of incubation. Intracellular amastigotes were inhibited by the compound, with an IC50 of 10.7 µM. BenzCo altered the shape, size, and ultrastructure of the parasites. Mitochondrial membrane depolarization was observed in protozoa treated with BenzCo but caused no alterations in the plasma membrane. Additionally, BenzCo induced lipoperoxidation and the production of mitochondrial superoxide anion radicals in promastigotes and axenic amastigotes of Leishmania amazonensis. Conclusion/Significance Our studies indicated that the antileishmania activity of BenzCo might be associated with mitochondrial dysfunction and oxidative damage, leading to parasite death.

Britta, Elizandra Aparecida; Barbosa Silva, Ana Paula; Ueda-Nakamura, Tania; Dias-Filho, Benedito Prado; Silva, Cleuza Conceicao; Sernaglia, Rosana Lazara; Nakamura, Celso Vataru

2012-01-01

67

Benzaldehyde thiosemicarbazone derived from limonene complexed with copper induced mitochondrial dysfunction in Leishmania amazonensis.  

UK PubMed Central (United Kingdom)

BACKGROUND: Leishmaniasis is a major health problem that affects more than 12 million people. Treatment presents several problems, including high toxicity and many adverse effects, leading to the discontinuation of treatment and emergence of resistant strains. METHODOLOGY/PRINCIPAL FINDINGS: We evaluated the in vitro antileishmanial activity of benzaldehyde thiosemicarbazone derived from limonene complexed with copper, termed BenzCo, against Leishmania amazonensis. BenzCo inhibited the growth of the promastigote and axenic amastigote forms, with IC(50) concentrations of 3.8 and 9.5 µM, respectively, with 72 h of incubation. Intracellular amastigotes were inhibited by the compound, with an IC(50) of 10.7 µM. BenzCo altered the shape, size, and ultrastructure of the parasites. Mitochondrial membrane depolarization was observed in protozoa treated with BenzCo but caused no alterations in the plasma membrane. Additionally, BenzCo induced lipoperoxidation and the production of mitochondrial superoxide anion radicals in promastigotes and axenic amastigotes of Leishmania amazonensis. CONCLUSION/SIGNIFICANCE: Our studies indicated that the antileishmania activity of BenzCo might be associated with mitochondrial dysfunction and oxidative damage, leading to parasite death.

Britta EA; Silva AP; Ueda-Nakamura T; Dias-Filho BP; Silva CC; Sernaglia RL; Nakamura CV

2012-01-01

68

A novel alkyl phosphocholine-dinitroaniline hybrid molecule exhibits biological activity in vitro against Leishmania amazonensis.  

UK PubMed Central (United Kingdom)

Parasitic protozoa of the Leishmania genus cause leishmaniasis, an important complex of tropical diseases that affect about 12million people around the world. The drugs used to treat leishmaniasis are pentavalent antimonials, miltefosine, amphotericin B and pentamidine. In the present study, we evaluated the effect of a novel alkyl phosphocholine-dinitroaniline hybrid molecule, TC95, against Leishmania amazonensis promastigotes and intracellular amastigotes. Antiproliferative assays indicated that TC95 is a potent inhibitor of promastigotes and intracellular amastigotes with IC50 values of 2.6 and 1.2?M, respectively. Fluorescence microscopy with anti-?-tubulin antibody revealed changes in the cytoskeleton, whilst scanning electron microscopy showed alterations in the shape, plasma membrane, length of the flagellum, and cell cycle. Flow cytometry confirmed the cell cycle arrest mainly in G1 phase, however a significant population appeared in sub G0/G1 and super-G2. The alterations in the plasma membrane integrity were confirmed by fluorometric analysis using Sytox Blue. Transmission electron microscopy also revealed an accumulation of lipid bodies, confirmed by fluorescence microscopy and fluorometric analysis using Nile Red. Important lesions were also observed in organelles such as mitochondrion, endoplasmic reticulum and Golgi complex. In summary, our study suggests that TC95, an alkyl phosphocholine-trifluralin hybrid molecule, is a promising novel compound against L. amazonensis.

Godinho JL; Georgikopoulou K; Calogeropoulou T; de Souza W; Rodrigues JC

2013-09-01

69

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

Science.gov (United States)

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 ?g/mL). The polysaccharides derived from Bo and Sf demonstrated moderate anti-leishmanial activity (EC50 values of 63.7 ?g/mL and 137.4 ?g/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 ?g/mL, 49.3 ?g/mL, 73.2 ?g/mL, and 99.8 ?g/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

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

70

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 ?g/mL). The polysaccharides derived from Bo and Sf demonstrated moderate anti-leishmanial activity (EC50 values of 63.7 ?g/mL and 137.4 ?g/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 ?g/mL, 49.3 ?g/mL, 73.2 ?g/mL, and 99.8 ?g/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.

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

2013-01-01

71

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

UK PubMed Central (United Kingdom)

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 ?g/mL). The polysaccharides derived from Bo and Sf demonstrated moderate anti-leishmanial activity (EC50 values of 63.7 ?g/mL and 137.4 ?g/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 ?g/mL, 49.3 ?g/mL, 73.2 ?g/mL, and 99.8 ?g/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.

Lehnhardt Pires C; Rodrigues SD; Bristot D; Gaeta HH; de Oliveira Toyama D; Lobo Farias WR; Toyama MH

2013-03-01

72

The stepwise selection for ketoconazole resistance induces upregulation of C14-demethylase (CYP51) in Leishmania amazonensis  

Directory of Open Access Journals (Sweden)

Full Text Available Ketoconazole is a clinically safe antifungal agent that also inhibits the growth of Leishmania spp. A study was undertaken to determine whether Leishmania parasites are prone to becoming resistant to ketoconazole by upregulating C14-demethylase after stepwise pharmacological pressure. Leishmania amazonensis promastigotes [inhibitory concentration (IC)50 = 2 µM] were subjected to stepwise selection with ketoconazole and two resistant lines were obtained, La8 (IC50 = 8 µM) and La10 (IC50 = 10 µM). As a result, we found that the resistance level was directly proportional to the C14-demethylase mRNA expression level; we also observed that expression levels were six and 12 times higher in La8 and La10, respectively. This is the first demonstration that L. amazonensis can up-regulate C14-demethylase in response to drug pressure and this report contributes to the understanding of the mechanisms of parasite resistance.

Valter Viana Andrade-Neto; Herbert Leonel de Matos-Guedes; Daniel Cláudio de Oliveira Gomes; Marilene Marcuzzo do Canto-Cavalheiro; Bartira Rossi-Bergmann; Eduardo Caio Torres-Santos

2012-01-01

73

The stepwise selection for ketoconazole resistance induces upregulation of C14-demethylase (CYP51) in Leishmania amazonensis.  

UK PubMed Central (United Kingdom)

Ketoconazole is a clinically safe antifungal agent that also inhibits the growth of Leishmania spp. A study was undertaken to determine whether Leishmania parasites are prone to becoming resistant to ketoconazole by upregulating C14-demethylase after stepwise pharmacological pressure. Leishmania amazonensis promastigotes [inhibitory concentration (IC)?? = 2 µM] were subjected to stepwise selection with ketoconazole and two resistant lines were obtained, La8 (IC?? = 8 µM) and La10 (IC?? = 10 µM). As a result, we found that the resistance level was directly proportional to the C14-demethylase mRNA expression level; we also observed that expression levels were six and 12 times higher in La8 and La10, respectively. This is the first demonstration that L. amazonensis can up-regulate C14-demethylase in response to drug pressure and this report contributes to the understanding of the mechanisms of parasite resistance.

Andrade-Neto VV; Matos-Guedes HL; Gomes DC; Canto-Cavalheiro MM; Rossi-Bergmann B; Torres-Santos EC

2012-05-01

74

Entry and survival of Leishmania amazonensis amastigotes within phagolysosome-like vacuoles that shelter Coxiella burnetii in Chinese hamster ovary cells.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Coxiella burnetii, a rickettsia, and Leishmania amazonensis, a protozoan flagellate, lodge in their host cells within large phagolysosome-like vacuoles. In the present study, C. burnetii-infected Vero or CHO cells were superinfected with L. amazonensis amastigotes to determine if these parasites can...

Veras, P S; Moulia, C; Dauguet, C; Tunis, C T; Thibon, M; Rabinovitch, M

75

Activity of the Lupane isolated from Combretum leprosum against Leishmania amazonensis promastigotes  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O presente trabalho descreve a atividade do extrato etanólico (EE) dos frutos de Combretum leprosum, do triterpeno 3?, 6?, 16?-triidroxilup-20(29)-eno (1) e seus derivados sintéticos (1a-1d), sobre promastigotas de Leishmaniaamazonensis. O EE apresentou atividade leishmanicida e o valor de IC50 foi de 24,8 µg mL-1. Já o triterpeno 3?, 6?, 16?-trihidroxilup-20(29)-eno (1), na concentração de 5,0 µg mL-1, apresentou uma potente ação in (more) ibitória sobre a proliferação das promastigotas (IC50 = 3,3 µg mL-1). Entre os derivados sintéticos, apenas 1b e 1d apresentaram atividade contra as promastigotas (IC50 = 3,48 µg mL-1e 5,8 µg mL-1, respectivamente). Por outro lado, o derivado sintético 1a não apresentou atividade sobre as promastigotas de L. amazonensis. O EE, (1) e os derivados sintéticos 1a-1d não apresentaram efeito citotóxico sobre macrófagos peritoneais de camundongos. Estes resultados fornecem evidencias de que o extrato etanólico e o lupano isolado de C. leprosum possui atividade contra promastigotas de L. amazonensis, podendo ser utilizados como ferramentas no estudo de novas drogas leishmanicidas. Abstract in english This paper describes the activity of the ethanolic extract (EE), obtained from the fruits of Combretum leprosum, the triterpene 3?, 6?, 16?-trihydroxylup-20(29)-ene (1) and its synthetic derivatives 1a-1d on Leishmania amazonensis promastigotes. The EE displayed leishmanicidal activity and the IC50 was 24.8 mg mL-1. However, the triterpene 3?, 6?, 16?-trihydroxylup-20(29)-ene (1), at a concentration of 5.0 mg mL-1, showed a potent inhibitory (more) activity on promastigotes proliferation (IC50 = 3.3 mg mL-1). Among the synthetic derivatives, only (1b) and (1d) were active against promastigotes (IC50 = 3.48 mg mL-1and 5.8 mg mL-1, respectively). Moreover, the synthetic derivative 1a showed no activity on promastigotes of L. amazonensis. EE, (1) and the synthetic derivatives 1a-1d showed no cytotoxic effect on mice peritoneal macrophages. These results provide evidence that the ethanolic extract and the lupane isolated from C. leprosum was active against promastigotes of L. amazonensis, and may be used as a tool in the studies of new antileishmanial drugs.

Teles, Carolina B. G; Moreira, Leandro S; Silva, Alexandre de A. E; Facundo, Valdir A; Zuliani, Juliana P; Stábeli, Rodrigo G; Silva-Jardim, Izaltina

2011-05-01

76

The action of ionizing radiation on the morphology, physiology and growth of Leishmania Amazonensis, with evaluation of their immunogenic power in experimental models; Acao da radiacao ionizante sobre a morfologia, fisiologia e crescimento da Leishmania amazonensis, com avaliacao de seu poder imunogenico em modelos experimentais  

Energy Technology Data Exchange (ETDEWEB)

Leishmaniasis is a disease which affects thousands of people in the Tropical regions around the world, is caused by a protozoan of the genus Leishmania spp., with urban and wild mammals acting as reservoirs. In the mammal host, the amastigote form of the parasite infects and multiplies into macrophages. Treatments for leishmaniasis have a high cost and are long lasting, frequently resulting in therapy interruption. This procedure culminates with a selection of resistant parasite strains, inducing tolerance to the therapy. Either the control of vectors or the mammal host are difficult due the social and economic implications. Thus, the search for alternatives treatments against these protozoans have been stimulated. The gamma radiation ({sup 60}CO) shown to be an efficient toll to kill these parasites maintaining their immunogenicity. Cellular viability, Electronically microscopy and Multiplex-PCR techniques showed that, after irradiation, the parasites had their growth inhibited by cytoplasmatic and nucleic material disorganisation, appointing the gamma radiation as important in terms of immunogens improvement. (author)

Bonetti, Franco Claudio

2002-07-01

77

Antileishmanial activity of crude extract and coumarin from Calophyllum brasiliense leaves against Leishmania amazonensis.  

UK PubMed Central (United Kingdom)

Infections by protozoans of the genus Leishmania are a major worldwide health problem, with high endemicity in developing countries. The drugs of choice for the treatment of leishmaniasis are the pentavalent antimonials, which show renal and cardiac toxicity. As part of a search for new drugs against leishmaniasis, we evaluated the in vitro leishmanicidal activity of the (-) mammea A/BB. The compound (-) mammea A/BB is a coumarin-type mammea purified from a dichloromethane crude extract of leaves of Calophyllum brasiliense Cambess (Clusiaceae). The isolated compound was characterized using spectral analyses by UV, infrared, nuclear magnetic resonance of (1)H, (13)C, distortionless enhancement by polarization transfer, correlation spectroscopy, heteronuclear multiple bond correlation, and heteronuclear multiple quantum coherence. The compound (-) mammea A/BB showed significant activity against promastigote and amastigote forms of L. amazonensis, with IC(50) (50% inhibition concentration of cell growth) at a concentration of 3.0 and 0.88 mug/ml and IC(90) (90% inhibition concentration of cell growth) of 5.0 and 2.3 microg/ml, respectively. The coumarin (-) mammea A/BB showed no cytotoxicity against J774G8 macrophages in culture, when it was tested at high concentrations that inhibited promastigote forms. Electron microscopy studies revealed considerable ultrastructural changes when promastigote forms of L. amazonensis were treated with 3.0 microg/ml of the coumarin (-) mammea A/BB for 72 h. We observed significant changes such as mitochondrial swelling with concentric membranes in the mitochondrial matrix and intense exocytic activity in the region of the flagellar pocket. Other alterations included the appearance of binucleate cells and multiple cytoplasmic vacuolization. These results showed that (-) mammea A/BB is a potent growth inhibitor of L. amazonensis and caused important changes in the parasite's ultrastructure. This study provided new perspectives on the development of novel drugs with leishmanicidal activity obtained from natural products.

Brenzan MA; Nakamura CV; Prado Dias Filho B; Ueda-Nakamura T; Young MC; Aparício Garcia Cortez D

2007-08-01

78

Antileishmanial activity of crude extract and coumarin from Calophyllum brasiliense leaves against Leishmania amazonensis.  

Science.gov (United States)

Infections by protozoans of the genus Leishmania are a major worldwide health problem, with high endemicity in developing countries. The drugs of choice for the treatment of leishmaniasis are the pentavalent antimonials, which show renal and cardiac toxicity. As part of a search for new drugs against leishmaniasis, we evaluated the in vitro leishmanicidal activity of the (-) mammea A/BB. The compound (-) mammea A/BB is a coumarin-type mammea purified from a dichloromethane crude extract of leaves of Calophyllum brasiliense Cambess (Clusiaceae). The isolated compound was characterized using spectral analyses by UV, infrared, nuclear magnetic resonance of (1)H, (13)C, distortionless enhancement by polarization transfer, correlation spectroscopy, heteronuclear multiple bond correlation, and heteronuclear multiple quantum coherence. The compound (-) mammea A/BB showed significant activity against promastigote and amastigote forms of L. amazonensis, with IC(50) (50% inhibition concentration of cell growth) at a concentration of 3.0 and 0.88 mug/ml and IC(90) (90% inhibition concentration of cell growth) of 5.0 and 2.3 microg/ml, respectively. The coumarin (-) mammea A/BB showed no cytotoxicity against J774G8 macrophages in culture, when it was tested at high concentrations that inhibited promastigote forms. Electron microscopy studies revealed considerable ultrastructural changes when promastigote forms of L. amazonensis were treated with 3.0 microg/ml of the coumarin (-) mammea A/BB for 72 h. We observed significant changes such as mitochondrial swelling with concentric membranes in the mitochondrial matrix and intense exocytic activity in the region of the flagellar pocket. Other alterations included the appearance of binucleate cells and multiple cytoplasmic vacuolization. These results showed that (-) mammea A/BB is a potent growth inhibitor of L. amazonensis and caused important changes in the parasite's ultrastructure. This study provided new perspectives on the development of novel drugs with leishmanicidal activity obtained from natural products. PMID:17483964

Brenzan, Mislaine Adriana; Nakamura, Celso Vataru; Prado Dias Filho, Benedito; Ueda-Nakamura, Tânia; Young, Maria Claudia M; Aparício Garcia Cortez, Diógenes

2007-05-05

79

Synthesis and biological evaluation against Leishmania amazonensis of a series of alkyl-substituted benzophenones.  

Science.gov (United States)

Nine O-alkyl and O-prenyl derivatives were synthesized from commercial 2,4-dihydroxybenzophenone, 4,e4,4'-dihydroxybenzophenone and were evaluated for their leishmanicidal activity against promastigote forms of Leishmania amazonensis, as well their toxicity in murine macrophages. All derivatives exhibited better biological activity than their hydroxylated benzophenones precursors, and new compound LFQM-123 (3c) was 250-fold more active than its precursor 4,4'-dihydroxybenzophenone (3). Moreover, some of the results were comparable to the standard drug Amphotericin B, suggesting that the increase in lipophilicity could facilitate protozoa membrane permeation. In this study we confirmed that benzophenone derivatives exhibit leishmanicidal properties, with relatively low toxicity, and thus could be exploited as promise prototypes for the design and development of new drug for the treatment of leishmaniasis. PMID:23623672

Maciel-Rezende, Claudia Mara; de Almeida, Letícia; Costa, Éderson D'Martin; Pires, Francieli Ribeiro; Alves, Karina Ferreira; Viegas, Cláudio; Dias, Danielle Ferreira; Doriguetto, Antônio Carlos; Marques, Marcos José; dos Santos, Marcelo Henrique

2013-03-30

80

Synthesis and biological evaluation against Leishmania amazonensis of a series of alkyl-substituted benzophenones.  

UK PubMed Central (United Kingdom)

Nine O-alkyl and O-prenyl derivatives were synthesized from commercial 2,4-dihydroxybenzophenone, 4,e4,4'-dihydroxybenzophenone and were evaluated for their leishmanicidal activity against promastigote forms of Leishmania amazonensis, as well their toxicity in murine macrophages. All derivatives exhibited better biological activity than their hydroxylated benzophenones precursors, and new compound LFQM-123 (3c) was 250-fold more active than its precursor 4,4'-dihydroxybenzophenone (3). Moreover, some of the results were comparable to the standard drug Amphotericin B, suggesting that the increase in lipophilicity could facilitate protozoa membrane permeation. In this study we confirmed that benzophenone derivatives exhibit leishmanicidal properties, with relatively low toxicity, and thus could be exploited as promise prototypes for the design and development of new drug for the treatment of leishmaniasis.

Maciel-Rezende CM; de Almeida L; Costa ÉD; Pires FR; Alves KF; Viegas C Jr; Dias DF; Doriguetto AC; Marques MJ; dos Santos MH

2013-06-01

 
 
 
 
81

Pravastatin modulates macrophage functions of Leishmania (L.) amazonensis-infected BALB/c mice.  

UK PubMed Central (United Kingdom)

The control of leishmaniases poses an important challenge due to the scarcity and toxicity of the pharmacological options available. We have previously shown that pravastatin significantly improves the course of the disease in Leishmania (L.) amazonensis-infected BALB/c mice. Since the drug caused no direct effect on the parasite, we decided to evaluate its immunomodulatory action in this experimental model. To evaluate the impact of pravastatin treatment, BALB/c mice infected or not with L. (L.) amazonensis were treated with pravastatin (20 mg/kg daily) or saline during 30 or 90 days and phagocytosis, hydrogen peroxide, nitric oxide and the tumor necrosis factor production by peritoneal macrophages were assessed. We showed that pravastatin increased the phagocytosis mediated by complement and immunoglobulin receptors (63.5 to 130.3; p=0.03, t test), but not that occurring via pattern recognition receptors, induced a rise of nitric oxide production by macrophages (2.1 ?M to 12.9 ?M; p=0.04, Mann-Whitney test), endowing these cells to better kill ingested leishmania organisms, caused no modification of the otherwise increased production of hydrogen peroxide by macrophages, and reduced the overproduction of tumor necrosis factor (166.6 pg/mL to 3.9 pg/mL; p=0.016, Mann-Whitney test), a major component of the exacerbated inflammation associated to leishmaniases. Our findings point to the potential usefulness of pravastatin as an adjunct to the treatment of leishmaniases, based on its powerful immunomodulatory effects and low toxicity.

Kückelhaus CS; Kückelhaus SA; Tosta CE; Muniz-Junqueira MI

2013-05-01

82

Effect of extracts and isolated compounds from Chresta scapigera on viability of Leishmania amazonensis and Trypanosoma cruzi/ Efeito dos extratos e compostos isolados de Chresta scapigera sobre a viabilidade de Leishmania amazonensis e Trypanosoma cruzi  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O fracionamento dos extratos bioativos de Chresta scapigera proporcionou o isolamento de triterpenos e flavonóides, dentre os quais acetato de beta-amirina (1), acetate de 11alfa,12-oxidotaraxeril (2) e lupeol (3), assim como os flavonóides apigenina (6), caenferol (7), crisoeriol (8) e luteolina (9) mostraram-se ativos contra formas amastigotas de Leishmania amazonensis, enquanto, apenas os flavonóides (6), (7) e (9) apresentaram toxicidade contra as formas tripomastigotas de Trypanosoma cruzi. Abstract in english Fractionation of bioactive crude extracts of Chresta scapigera led to the isolation of four triterpenes and five flavonoids, among them beta-amyrin acetate (1), 11alpha,12alpha-oxidetaraxeryl acetate (2) and lupeol (3), as well as the flavonoids apigenin (6), kaempferol (7), crysoeriol (8) and luteolin (9) were active against Leishmania amazonensis amastigotes-like stages, while only the flavonoids (6), (7) and (9) showed toxicity towards bloods trypomastigote forms of Trypanosoma cruzi.

Schinor, Elisandra Cristina; Salvador, Marcos José; Pral, Elisabeth Mieko Furusho; Alfieri, Silvia Celina; Albuquerque, Sérgio; Dias, Diones Aparecida

2007-06-01

83

Effect of extracts and isolated compounds from Chresta scapigera on viability of Leishmania amazonensis and Trypanosoma cruzi Efeito dos extratos e compostos isolados de Chresta scapigera sobre a viabilidade de Leishmania amazonensis e Trypanosoma cruzi  

Directory of Open Access Journals (Sweden)

Full Text Available Fractionation of bioactive crude extracts of Chresta scapigera led to the isolation of four triterpenes and five flavonoids, among them beta-amyrin acetate (1), 11alpha,12alpha-oxidetaraxeryl acetate (2) and lupeol (3), as well as the flavonoids apigenin (6), kaempferol (7), crysoeriol (8) and luteolin (9) were active against Leishmania amazonensis amastigotes-like stages, while only the flavonoids (6), (7) and (9) showed toxicity towards bloods trypomastigote forms of Trypanosoma cruzi.O fracionamento dos extratos bioativos de Chresta scapigera proporcionou o isolamento de triterpenos e flavonóides, dentre os quais acetato de beta-amirina (1), acetate de 11alfa,12-oxidotaraxeril (2) e lupeol (3), assim como os flavonóides apigenina (6), caenferol (7), crisoeriol (8) e luteolina (9) mostraram-se ativos contra formas amastigotas de Leishmania amazonensis, enquanto, apenas os flavonóides (6), (7) e (9) apresentaram toxicidade contra as formas tripomastigotas de Trypanosoma cruzi.

Elisandra Cristina Schinor; Marcos José Salvador; Elisabeth Mieko Furusho Pral; Silvia Celina Alfieri; Sérgio Albuquerque; Diones Aparecida Dias

2007-01-01

84

Structure-activity relationship of (-) mammea A/BB derivatives against Leishmania amazonensis.  

UK PubMed Central (United Kingdom)

To study the structure-activity relationship of coumarin (-) mammea A/BB isolated from the CH(2)Cl(2) extract of Calophyllum brasiliense leaves, we evaluated the antileishmanial activity of natural, synthetic and derivatives of this coumarin, against promastigote and intracellular amastigote forms of Leishmania amazonensis, and their cytotoxicity to J774G8 murine macrophages. The derivatives were obtained by hydrogenation and methoxylation reactions. The compound structures were elucidated on the basis of spectroscopic data. The compounds 5,7-dihydroxy-8-(2-methylbutanoyl)-6-(3-methylbutyl)-4-phenyl-chroman-2-one (3), 7-hydroxy-5-methoxy-8-(2-methylbutanoyl)-6-(3-methylbut-2-en-1-yl)-4-phenylcoumarin (4) and 5,7-dimethoxy-8-(1-methoxy-2-methylbutyl)-6-(3-methylbut-2-en-1-yl)-4 phenylcoumarin (6) were more biologically active than the compound (-) mammea A/BB (1) (7.4 microM), with IC(50) values from 0.9, 2.4 and 1.9 microM respectively; compound (3) displayed the highest activity. The compounds mammea B/BB (2), 5,7-dimethoxy-8-(2-methylbutanoyl)-6-(3-methylbut-2-en-1-yl)-4-phenylcoumarin (5) and 5,7-dihydroxy-4-phenylcoumarin (7) were less active than (-) mammea A/BB (1), with IC(50) of 30.1, 15.1 and 60.2 microM respectively; compound (7) showed the lowest antileishmanial activity of all. Compounds (1), (3), (4) and (6) were active not only against promastigote forms of L. amazonensis, but also against intracellular amastigote forms with IC(50) of 14.3, 0.6, 34.0 and 22.2 microM, respectively. Interestingly, compound (3) showed the most antileishmanial activity of all. This study demonstrated that several aspects of the structure were important for antileishmanial activity.

Brenzan MA; Nakamura CV; Dias Filho BP; Ueda-Nakamura T; Young MC; Côrrea AG; Alvim J Jr; dos Santos AO; Cortez DA

2008-11-01

85

Structure-activity relationship of (-) mammea A/BB derivatives against Leishmania amazonensis.  

Science.gov (United States)

To study the structure-activity relationship of coumarin (-) mammea A/BB isolated from the CH(2)Cl(2) extract of Calophyllum brasiliense leaves, we evaluated the antileishmanial activity of natural, synthetic and derivatives of this coumarin, against promastigote and intracellular amastigote forms of Leishmania amazonensis, and their cytotoxicity to J774G8 murine macrophages. The derivatives were obtained by hydrogenation and methoxylation reactions. The compound structures were elucidated on the basis of spectroscopic data. The compounds 5,7-dihydroxy-8-(2-methylbutanoyl)-6-(3-methylbutyl)-4-phenyl-chroman-2-one (3), 7-hydroxy-5-methoxy-8-(2-methylbutanoyl)-6-(3-methylbut-2-en-1-yl)-4-phenylcoumarin (4) and 5,7-dimethoxy-8-(1-methoxy-2-methylbutyl)-6-(3-methylbut-2-en-1-yl)-4 phenylcoumarin (6) were more biologically active than the compound (-) mammea A/BB (1) (7.4 microM), with IC(50) values from 0.9, 2.4 and 1.9 microM respectively; compound (3) displayed the highest activity. The compounds mammea B/BB (2), 5,7-dimethoxy-8-(2-methylbutanoyl)-6-(3-methylbut-2-en-1-yl)-4-phenylcoumarin (5) and 5,7-dihydroxy-4-phenylcoumarin (7) were less active than (-) mammea A/BB (1), with IC(50) of 30.1, 15.1 and 60.2 microM respectively; compound (7) showed the lowest antileishmanial activity of all. Compounds (1), (3), (4) and (6) were active not only against promastigote forms of L. amazonensis, but also against intracellular amastigote forms with IC(50) of 14.3, 0.6, 34.0 and 22.2 microM, respectively. Interestingly, compound (3) showed the most antileishmanial activity of all. This study demonstrated that several aspects of the structure were important for antileishmanial activity. PMID:18849135

Brenzan, Mislaine Adriana; Nakamura, Celso Vataru; Dias Filho, Benedito Prado; Ueda-Nakamura, Tânia; Young, Maria Claudia M; Côrrea, Arlene Gonçalves; Alvim, Joel; dos Santos, Adriana Oliveira; Cortez, Diógenes Aparício Garcia

2008-09-17

86

Activity of recombinant and natural defensins from Vigna unguiculata seeds against Leishmania amazonensis.  

Science.gov (United States)

Antimicrobial peptides (AMPs), which are differentiated from other antibiotic peptides, such as gramicidins and polymyxins, because they are synthesized by large enzymatic complex and bear modified amino acids including d-amino acids, are short polymers of l-amino acids synthesized by ribosomes upon which all living organisms rely to defend themselves from invaders or competitor microorganisms. AMPs have received a great deal of attention from the scientific community as potential new drugs for neglected diseases such as Leishmaniasis. In plants, they include several families of compounds, including the plant defensins. The aim of the present study was to improve the expression of recombinant defensin from Vigna unguiculata seeds (Vu-Defr) and to test its activity against Leishmania amazonensis promatigotes. Recombinant expression was performed in LB and TB media and under different conditions. The purification of Vu-Defr was achieved by immobilized metal ion affinity and reversed-phase chromatography. The purified Vu-Defr was analyzed by circular dichroism (CD), and its biological activity was tested against L. amazonenis promastigotes. To demonstrate that the recombinant production of Vu-Defr did not interfere with its fold and biological activity, the results of all experiments were compared with the results from the natural defensin (Vu-Def). The CD spectra of both peptides presented good superimposition indicating that both peptides present very similar secondary structure and that the Vu-Defr was correctly folded. L. amazonensis treated with Vu-Defr led to the elimination of 54.3% and 46.9% of the parasites at 24 and 48h of incubation time, respectively. Vu-Def eliminated 50% and 54.8% of the parasites at 24 and 48h, respectively. Both were used at a concentration of 100?g/mL. These results suggested the potential for plant defensins to be used as new antiparasitic substances. PMID:23816644

Souza, Géssika Silva; do Nascimento, Viviane Veiga; de Carvalho, Laís Pessanha; de Melo, Edésio José Tenório; Fernandes, Keysson Vieira; Machado, Olga Lima Tavares; Retamal, Claudio Andres; Gomes, Valdirene Moreira; Carvalho, André de Oliveira

2013-06-28

87

Activity of recombinant and natural defensins from Vigna unguiculata seeds against Leishmania amazonensis.  

UK PubMed Central (United Kingdom)

Antimicrobial peptides (AMPs), which are differentiated from other antibiotic peptides, such as gramicidins and polymyxins, because they are synthesized by large enzymatic complex and bear modified amino acids including d-amino acids, are short polymers of l-amino acids synthesized by ribosomes upon which all living organisms rely to defend themselves from invaders or competitor microorganisms. AMPs have received a great deal of attention from the scientific community as potential new drugs for neglected diseases such as Leishmaniasis. In plants, they include several families of compounds, including the plant defensins. The aim of the present study was to improve the expression of recombinant defensin from Vigna unguiculata seeds (Vu-Defr) and to test its activity against Leishmania amazonensis promatigotes. Recombinant expression was performed in LB and TB media and under different conditions. The purification of Vu-Defr was achieved by immobilized metal ion affinity and reversed-phase chromatography. The purified Vu-Defr was analyzed by circular dichroism (CD), and its biological activity was tested against L. amazonenis promastigotes. To demonstrate that the recombinant production of Vu-Defr did not interfere with its fold and biological activity, the results of all experiments were compared with the results from the natural defensin (Vu-Def). The CD spectra of both peptides presented good superimposition indicating that both peptides present very similar secondary structure and that the Vu-Defr was correctly folded. L. amazonensis treated with Vu-Defr led to the elimination of 54.3% and 46.9% of the parasites at 24 and 48h of incubation time, respectively. Vu-Def eliminated 50% and 54.8% of the parasites at 24 and 48h, respectively. Both were used at a concentration of 100?g/mL. These results suggested the potential for plant defensins to be used as new antiparasitic substances.

Souza GS; do Nascimento VV; de Carvalho LP; de Melo EJ; Fernandes KV; Machado OL; Retamal CA; Gomes VM; Carvalho Ade O

2013-09-01

88

Further observations on clinical, histopathological, and immunological features of borderline disseminated cutaneous leishmaniasis caused by Leishmania (Leishmania) amazonensis  

Directory of Open Access Journals (Sweden)

Full Text Available Leishmania (Leishmania) amazonensis has for some time been considered as the causative agent of two distinct forms of American cutaneous leishmaniasis (ACL): localized cutaneous leishmaniasis (LCL), and anergic diffuse cutaneous leishmaniasis (ADCL). Recently, a new intermediate form of disease, borderline disseminated cutaneous leishmaniasis (BDCL), was introduced into the clinical spectrum of ACL caused by this parasite, and in this paper we record the clinical, histopathological, and immunological features of eight more BDCL patients from Brazilian Amazonia, who acquired the disease in the Pará state, North Brazil. Seven of them had infections of one to two years' evolution and presented with primary skin lesions and the occurrence of metastases at periods varying from six to 12 months following appearance of the first lesion. Primary skin lesions ranged from 1-3 in number, and all had the aspect of an erythematous, infiltrated plaque, variously located on the head, arms or legs. There was lymphatic dissemination of infection, with lymph node enlargement in seven of the cases, and the delayed hypersensitivity skin-test (DTH) was negative in all eight patients prior to their treatment. After that, there was a conversion of DTH to positive in five cases re-examined. The major histopathological feature was a dermal mononuclear infiltration, with a predominance of heavily parasitized and vacuolated macrophages, together with lymphocytes and plasma cells. In one case, with similar histopathology, the patient had acquired his infection seven years previously and he presented with the largest number of disseminated cutaneous lesions. BDCL shows clinical and histopathological features which are different from those of both LCL and ADCL, and there is a good prognosis of cure which is generally not so in the case of frank ADCL.

Fernando T Silveira; Ralph Lainson; Carlos EP Corbett

2005-01-01

89

Inmunización con subgenoteca de Leishmania amazonensis protege contra el reto a ratones BALB/c  

Directory of Open Access Journals (Sweden)

Full Text Available Se construyó una genoteca de Leishmania amazonensis en vector de expresión en células eucariotas (pEF1HisA, pEF1HisB, pEF1HisC). Se prepararon 2 subgenotecas con un número aproximado de 500 clones cada una y ratones BALB/c fueron inmunizados con 50 mg/0,1 mL de ADN de cada una; 2 inmunizaciones por vía IM, con 15 d de intervalo fueron realizadas. Grupos de ratones controles fueron inmunizados con ADN del plásmido vacío, con antígeno soluble del parásito (100 mg/0,1 mL) y solución salina fisiológica. Se midió el tamaño de las lesiones durante 12 semanas y al final del experimento, la carga parasitaria en los sitios de lesión fue determinada por el método de microtitulación en placas. Los ratones inmunizados con ADN 1, controlaron el tamaño de las lesiones, así como también los inmunizados con antígenos solubles, lo que alcanzó diferencia estadística (pA genomic library of Leishmania amazonensis in expression vector of eukaryote cells (pEF1HisA, pEF1HisB, pEF1HisC) was prepared. Also two subgenomic libraries having each 500 clones approximately were created and BALB/c mice were immunized with 50 mg/0,1 mL of DNA from each. Two immunizations were administered intramuscularly at 15-day interval. Groups of control mice were immunized with DNA from empty plasmid pEF1His, with soluble parasite antigen (100 mg/0,1 mL) and saline solution. The size of lesions was measured for 12 weeks and at the end of the experiment, the parasite load at lesion sites was determined by plaque microtitration method. In mice immunized with subgenomic library DNA1 and with soluble antigens,the size of lesions was controlled, which reached an statistical difference (p< 0,05) in relation to the rest of groups whose lesions increased. The parasite load found in lesion sites confirmed the previous results; the number of promastigots was significantly lower in those mice already protected. It was concluded that in subgenomic library DNA1 there should be genes or gene fragments whose in vivo expression induces protective immune response against the challenge in the murine model used

Ana M Montalvo Álvarez; Lianet Monzote Fidalgo; Lisset Fonseca Géigel; Ivón Montano Goodridge; Luis Fonte Galindo; Manuel Soto

2004-01-01

90

Effects of medicinal plant extracts on growth of Leishmania (L.) amazonensis and Trypanosoma cruzi Efeito de extratos de plantas medicinais no crescimento de Leishmania (L.) amazonensis e Trypanosoma cruzi  

Directory of Open Access Journals (Sweden)

Full Text Available This study describes the screening of extracts obtained from 19 species of plants used in Brazilian traditional medicine for treatment of a variety of diseases. The extracts were tested against axenic amastigote and promastigote forms of Leishmania (L.) amazonensis, and epimastigote forms of Trypanosoma cruzi in vitro at a concentration of 100 mg/ml. Baccharis trimera, Cymbopogon citratus, Matricaria chamomilla, Mikania glomerata, Ocimum gratissimum, Piper regnellii, Prunus domestica, Psidium guajava, Sambucus canadensis, Stryphnodendron adstringens, Tanacetum parthenium, and Tanacetum vulgare showed significant effects against one or both parasites, with a percentage of growth inhibition between 49.5 and 99%. The extracts showed no cytotoxic effect on sheep erythrocytes. These medicinal plants may be sources of new compounds that are clinically active against L. amazonensis and T. cruzi.Este estudo descreve a triagem de extratos obtidos de 19 espécies de plantas usadas na medicina tradicional brasileira para o tratamento de várias doenças. Os extratos foram testados contra formas amastigota axênica e promastigota de Leishmania (L.) amazonensis, e formas epimastigota de Trypanosoma cruzi in vitro na concentração de 100 mg/ml. Baccharis trimera, Cymbopogon citratus, Matricaria chamomilla, Mikania glomerata, Ocimum gratissimum, Piper regnellii, Prunus domestica, Psidium guajava, Sambucus canadensis, Stryphnodendron adstringens, Tanacetum parthenium, e Tanacetum vulgare apresentaram efeito significante contra um ou ambos parasitas, com a porcentagem de inibição de crescimento entre 49,5 e 99%. Os extratos não mostraram efeito citotóxico em hemácias de carneiro. Essas plantas medicinais podem ser fontes alternativas de novos compostos clinicamente ativos contra L. amazonensis e T. cruzi.

Patrícia Shima Luize; Tatiana Shioji Tiuman; Luis Gustavo Morello; Paloma Korehiza Maza; Tânia Ueda-Nakamura; Benedito Prado Dias Filho; Diógenes Aparício Garcia Cortez; João Carlos Palazzo de Mello; Celso Vataru Nakamura

2005-01-01

91

Effects of medicinal plant extracts on growth of Leishmania (L.) amazonensis and Trypanosoma cruzi/ Efeito de extratos de plantas medicinais no crescimento de Leishmania (L.) amazonensis e Trypanosoma cruzi  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Este estudo descreve a triagem de extratos obtidos de 19 espécies de plantas usadas na medicina tradicional brasileira para o tratamento de várias doenças. Os extratos foram testados contra formas amastigota axênica e promastigota de Leishmania (L.) amazonensis, e formas epimastigota de Trypanosoma cruzi in vitro na concentração de 100 mg/ml. Baccharis trimera, Cymbopogon citratus, Matricaria chamomilla, Mikania glomerata, Ocimum gratissimum, Piper regnellii, Prunus (more) domestica, Psidium guajava, Sambucus canadensis, Stryphnodendron adstringens, Tanacetum parthenium, e Tanacetum vulgare apresentaram efeito significante contra um ou ambos parasitas, com a porcentagem de inibição de crescimento entre 49,5 e 99%. Os extratos não mostraram efeito citotóxico em hemácias de carneiro. Essas plantas medicinais podem ser fontes alternativas de novos compostos clinicamente ativos contra L. amazonensis e T. cruzi. Abstract in english This study describes the screening of extracts obtained from 19 species of plants used in Brazilian traditional medicine for treatment of a variety of diseases. The extracts were tested against axenic amastigote and promastigote forms of Leishmania (L.) amazonensis, and epimastigote forms of Trypanosoma cruzi in vitro at a concentration of 100 mg/ml. Baccharis trimera, Cymbopogon citratus, Matricaria chamomilla, Mikania glomerata, Ocimum gratissimum, Piper regnellii, Prun (more) us domestica, Psidium guajava, Sambucus canadensis, Stryphnodendron adstringens, Tanacetum parthenium, and Tanacetum vulgare showed significant effects against one or both parasites, with a percentage of growth inhibition between 49.5 and 99%. The extracts showed no cytotoxic effect on sheep erythrocytes. These medicinal plants may be sources of new compounds that are clinically active against L. amazonensis and T. cruzi.

Luize, Patrícia Shima; Tiuman, Tatiana Shioji; Morello, Luis Gustavo; Maza, Paloma Korehiza; Ueda-Nakamura, Tânia; Dias Filho, Benedito Prado; Cortez, Diógenes Aparício Garcia; Mello, João Carlos Palazzo de; Nakamura, Celso Vataru

2005-03-01

92

Leishmania amazonensis Amastigotes Trigger Neutrophil Activation but Resist Neutrophil Microbicidal Mechanisms.  

Science.gov (United States)

Neutrophils are the first cells to infiltrate to the site of Leishmania promastigote infection, and these cells help to reduce parasite burden shortly after infection is initiated. Several clinical reports indicate that neutrophil recruitment is sustained over the course of leishmaniasis, and amastigote-laden neutrophils have been isolated from chronically infected patients and experimentally infected animals. The goal of this study was to compare how thioglycolate-elicited murine neutrophils respond to L. amazonensis metacyclic promastigotes and amastigotes derived from axenic cultures or from the lesions of infected mice. Neutrophils efficiently internalized both amastigote and promastigote forms of the parasite, and phagocytosis was enhanced in lipopolysaccharide (LPS)-activated neutrophils or when parasites were opsonized in serum from infected mice. Parasite uptake resulted in neutrophil activation, oxidative burst, and accelerated neutrophil death. While promastigotes triggered the release of tumor necrosis factor alpha (TNF-?), uptake of amastigotes preferentially resulted in the secretion of interleukin-10 (IL-10) from neutrophils. Finally, the majority of promastigotes were killed by neutrophils, while axenic culture- and lesion-derived amastigotes were highly resistant to neutrophil microbicidal mechanisms. This study indicates that neutrophils exhibit distinct responses to promastigote and amastigote infection. Our findings have important implications for determining the impact of sustained neutrophil recruitment and amastigote-neutrophil interactions during the late phase of cutaneous leishmaniasis. PMID:23918780

Carlsen, Eric D; Hay, Christie; Henard, Calvin A; Popov, Vsevolod; Garg, Nisha Jain; Soong, Lynn

2013-08-05

93

Leishmania amazonensis Amastigotes Trigger Neutrophil Activation but Resist Neutrophil Microbicidal Mechanisms.  

UK PubMed Central (United Kingdom)

Neutrophils are the first cells to infiltrate to the site of Leishmania promastigote infection, and these cells help to reduce parasite burden shortly after infection is initiated. Several clinical reports indicate that neutrophil recruitment is sustained over the course of leishmaniasis, and amastigote-laden neutrophils have been isolated from chronically infected patients and experimentally infected animals. The goal of this study was to compare how thioglycolate-elicited murine neutrophils respond to L. amazonensis metacyclic promastigotes and amastigotes derived from axenic cultures or from the lesions of infected mice. Neutrophils efficiently internalized both amastigote and promastigote forms of the parasite, and phagocytosis was enhanced in lipopolysaccharide (LPS)-activated neutrophils or when parasites were opsonized in serum from infected mice. Parasite uptake resulted in neutrophil activation, oxidative burst, and accelerated neutrophil death. While promastigotes triggered the release of tumor necrosis factor alpha (TNF-?), uptake of amastigotes preferentially resulted in the secretion of interleukin-10 (IL-10) from neutrophils. Finally, the majority of promastigotes were killed by neutrophils, while axenic culture- and lesion-derived amastigotes were highly resistant to neutrophil microbicidal mechanisms. This study indicates that neutrophils exhibit distinct responses to promastigote and amastigote infection. Our findings have important implications for determining the impact of sustained neutrophil recruitment and amastigote-neutrophil interactions during the late phase of cutaneous leishmaniasis.

Carlsen ED; Hay C; Henard CA; Popov V; Garg NJ; Soong L

2013-11-01

94

[Immunization with Leishmania amazonensis subgenomic libraries protects BALB/c mice against the challenge].  

UK PubMed Central (United Kingdom)

A genomic library of Leishmania amazonensis in expression vector of eukaryote cells (pEF1HisA, pEF1HisB, pEF1HisC) was prepared. Also two subgenomic libraries having each 500 clones approximately were created and BALB/c mice were immunized with 50 mg/0,1 mL of DNA from each. Two immunizations were administered intramuscularly at 15-day interval. Groups of control mice were immunized with DNA from empty plasmid pEF1His, with soluble parasite antigen (100 mg/0,1 mL) and saline solution. The size of lesions was measured for 12 weeks and at the end of the experiment, the parasite load at lesion sites was determined by plaque microtitration method. In mice immunized with subgenomic library DNAI and with soluble antigens,the size of lesions was controlled, which reached an statistical difference (p< 0,05) in relation to the rest of groups whose lesions increased. The parasite load found in lesion sites confirmed the previous results; the number of promastigots was significantly lower in those mice already protected. It was concluded that in subgenomic library DNA1 there should be genes or gene fragments whose in vivo expression induces protective immune response against the challenge in the murine model used.

MontalvoAlvarez AM; Fidalgo LM; Géigel LF; Goodridge IM; Galindo LF; Soto M; Requena JM

2004-05-01

95

Infection by Leishmania amazonensis in mice: a potential model for chronic hypoxia.  

Science.gov (United States)

Hypoxia is a common feature of injured and infected tissues. Hypoxia inducible factors 1? and 2? (HIF-1?, HIF-2?) are heterodimeric transcription factors mediating the cellular responses to hypoxia and also the vascular endothelial growth factor (VEGF). VEGF is a cytokine which can be induced by hypoxia, whose pathogenic mechanisms are still unclear and which is the subject of debate. Murine cutaneous lesions during Leishmania amazonensis parasite infection are chronic, although they are small and self-controlled in C57BL/6 mice and severe in BALB/c mice. In the present study we examined the presence of hypoxia, HIF-1?, HIF-2? and VEGF during the course of infection in both mouse strains. Hypoxia was detected in lesions from BALB/c mice by pimonidazole marking, which occurred earlier than in lesions from C57Bl/6 mice. The lesions in the BALB/c mice showed HIF-1? and HIF-2? expression in the cytoplasm of macrophages and failed to promote any VEGF expression, while lesions in the C57BL/6 mice showed HIF-2? nuclear accumulation and subsequent VEGF expression. In conclusion, the animal models of leishmaniasis demonstrated a diversity of patterns of expression, cell localization and activity of the main transducers of hypoxia and may be useful models for studying the pathogenic mechanisms of HIF-1? and HIF-2? during chronic hypoxic diseases. PMID:22360823

Araújo, Alexandra Paiva; Arrais-Silva, Wagner Welber; Giorgio, Selma

2012-02-22

96

Infection by Leishmania amazonensis in mice: a potential model for chronic hypoxia.  

UK PubMed Central (United Kingdom)

Hypoxia is a common feature of injured and infected tissues. Hypoxia inducible factors 1? and 2? (HIF-1?, HIF-2?) are heterodimeric transcription factors mediating the cellular responses to hypoxia and also the vascular endothelial growth factor (VEGF). VEGF is a cytokine which can be induced by hypoxia, whose pathogenic mechanisms are still unclear and which is the subject of debate. Murine cutaneous lesions during Leishmania amazonensis parasite infection are chronic, although they are small and self-controlled in C57BL/6 mice and severe in BALB/c mice. In the present study we examined the presence of hypoxia, HIF-1?, HIF-2? and VEGF during the course of infection in both mouse strains. Hypoxia was detected in lesions from BALB/c mice by pimonidazole marking, which occurred earlier than in lesions from C57Bl/6 mice. The lesions in the BALB/c mice showed HIF-1? and HIF-2? expression in the cytoplasm of macrophages and failed to promote any VEGF expression, while lesions in the C57BL/6 mice showed HIF-2? nuclear accumulation and subsequent VEGF expression. In conclusion, the animal models of leishmaniasis demonstrated a diversity of patterns of expression, cell localization and activity of the main transducers of hypoxia and may be useful models for studying the pathogenic mechanisms of HIF-1? and HIF-2? during chronic hypoxic diseases.

Araújo AP; Arrais-Silva WW; Giorgio S

2012-12-01

97

Intramuscular and topical treatment of cutaneous leishmaniasis lesions in mice infected with Leishmania amazonensis using coumarin (-) mammea A/BB.  

Science.gov (United States)

Treatment of cutaneous leishmaniasis remains limited to a few available options. Recent studies showed in vitro antileishmanial activity of (-) mammea A/BB, a coumarin isolated from leaves of Calophyllum brasiliense. Moreover, the dichloromethane crude extract and hexane fraction from this plant demonstrated in vivo activity in mice infected with Leishmania amazonensis. We evaluated the antileishmanial activity of (-) mammea A/BB in the L. amazonensis BALB/c mice model. The animals were given intramuscular and topical treatment with (-) mammea A/BB for 30 consecutive days. The results demonstrated that 18mg/kg/d intramuscularly or 0.2% topically of (-) mammea A/BB significantly reduced the size of skin lesions in footpads of mice compared with those in the control group (p<0.05). The activity of Glucantime(®) (corresponding to 27mg/kg/d of pentavalent antimony) administered intramuscularly was similar to that of (-) mammea A/BB (p<0.05) by both routes of administration. The histopathological evaluation showed no changes in the organs analyzed. These results indicate that the coumarin obtained from C. brasiliense is the antileishmanially active compound and can be used to control the development of cutaneous leishmaniasis lesions caused by L. amazonensis. PMID:22954418

Tiuman, Tatiana Shioji; Brenzan, Mislaine Adriana; Ueda-Nakamura, Tânia; Filho, Benedito Prado Dias; Cortez, Diógenes Aparicio Garcia; Nakamura, Celso Vataru

2012-09-04

98

Intramuscular and topical treatment of cutaneous leishmaniasis lesions in mice infected with Leishmania amazonensis using coumarin (-) mammea A/BB.  

UK PubMed Central (United Kingdom)

Treatment of cutaneous leishmaniasis remains limited to a few available options. Recent studies showed in vitro antileishmanial activity of (-) mammea A/BB, a coumarin isolated from leaves of Calophyllum brasiliense. Moreover, the dichloromethane crude extract and hexane fraction from this plant demonstrated in vivo activity in mice infected with Leishmania amazonensis. We evaluated the antileishmanial activity of (-) mammea A/BB in the L. amazonensis BALB/c mice model. The animals were given intramuscular and topical treatment with (-) mammea A/BB for 30 consecutive days. The results demonstrated that 18mg/kg/d intramuscularly or 0.2% topically of (-) mammea A/BB significantly reduced the size of skin lesions in footpads of mice compared with those in the control group (p<0.05). The activity of Glucantime(®) (corresponding to 27mg/kg/d of pentavalent antimony) administered intramuscularly was similar to that of (-) mammea A/BB (p<0.05) by both routes of administration. The histopathological evaluation showed no changes in the organs analyzed. These results indicate that the coumarin obtained from C. brasiliense is the antileishmanially active compound and can be used to control the development of cutaneous leishmaniasis lesions caused by L. amazonensis.

Tiuman TS; Brenzan MA; Ueda-Nakamura T; Filho BP; Cortez DA; Nakamura CV

2012-10-01

99

Flagellates in the Malpighian tubules of laboratory-bred Lutzomyia longipalpis fed on a hamster experimentally infected with Leishmania mexicana amazonensis  

Directory of Open Access Journals (Sweden)

Full Text Available As a preparatory stage for a study aiming at identifying the species and subspecies of local Leishmania in naturally infected sandflies through immunoradiometric assay with monoclonal antibodies, we tried to obtain experimental infections of phlebotomines with well characterized stocks of parasites, in order to test the effectiveness of the method.Encontramos abundantes promastigotas nos tubos de Malpighi, além do tubo digestivo, em elevada proporção de fêmeas de Lutzomyia longipalpis experimentalmente infectadas em hamster inoculado com Leishmania mexicana amazonensis.

Elizabeth Ferreira Rangel; Leonidas M. Deane; Gabriel Grimaldi Filho; Nataly A. de Souza; Eduardo D. Wermelinger; André F. Barbosa

1985-01-01

100

Identification of SL addition trans-splicing acceptor sites in the internal transcribed spacer I region of pre-rRNA in Leishmania (Leishmania) amazonensis  

Directory of Open Access Journals (Sweden)

Full Text Available Trypanosomatidae is a family of early branching eukaryotes harbouring a distinctive repertoire of gene expression strategies. Functional mature messenger RNA is generated via the trans-splicing and polyadenylation processing of constitutively transcribed polycistronic units. Recently, trans-splicing of pre-small subunit ribosomal RNA in the 5' external transcribed spacer region and of precursor tRNAsec have been described. Here, we used a previously validated semi-nested reverse transcription-polymerase chain reaction strategy to investigate internal transcribed spacer (ITS) I acceptor sites in total RNA from Leishmania (Leishmania) amazonensis. Two distinct spliced leader-containing RNAs were detected indicating that trans-splicing reactions occur at two AG acceptor sites mapped in this ITS region. These data provide further evidence of the wide spectrum of RNA molecules that act as trans-splicing acceptors in trypanosomatids.

Mario Gustavo Mayer; Lucile Maria Floeter-Winter

2012-01-01

 
 
 
 
101

Identification of SL addition trans-splicing acceptor sites in the internal transcribed spacer I region of pre-rRNA in Leishmania (Leishmania) amazonensis  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Trypanosomatidae is a family of early branching eukaryotes harbouring a distinctive repertoire of gene expression strategies. Functional mature messenger RNA is generated via the trans-splicing and polyadenylation processing of constitutively transcribed polycistronic units. Recently, trans-splicing of pre-small subunit ribosomal RNA in the 5' external transcribed spacer region and of precursor tRNAsec have been described. Here, we used a previously validated semi-nested (more) reverse transcription-polymerase chain reaction strategy to investigate internal transcribed spacer (ITS) I acceptor sites in total RNA from Leishmania (Leishmania) amazonensis. Two distinct spliced leader-containing RNAs were detected indicating that trans-splicing reactions occur at two AG acceptor sites mapped in this ITS region. These data provide further evidence of the wide spectrum of RNA molecules that act as trans-splicing acceptors in trypanosomatids.

Mayer, Mario Gustavo; Floeter-Winter, Lucile Maria

2012-12-01

102

Glycosphingolipid antigens from Leishmania (L.) amazonensis amastigotes: Binding of anti-glycosphingolipid monoclonal antibodies in vitro and in vivo  

Directory of Open Access Journals (Sweden)

Full Text Available Specific glycosphingolipid antigens of Leishmania (L.) amazonensis amastigotes reactive with the monoclonal antibodies (MoAbs) ST-3, ST-4 and ST-5 were isolated, and their structure was partially elucidated by negative ion fast atom bombardment mass spectrometry. The glycan moieties of five antigens presented linear sequences of hexoses and N-acetylhexosamines ranging from four to six sugar residues, and the ceramide moieties were found to be composed by a sphingosine d18:1 and fatty acids 24:1 or 16:0. Affinities of the three monoclonal antibodies to amastigote glycosphingolipid antigens were also analyzed by ELISA. MoAb ST-3 reacted equally well with all glycosphingolipid antigens tested, whereas ST-4 and ST-5 presented higher affinities to glycosphingolipids with longer carbohydrate chains, with five or more sugar units (slow migrating bands on HPTLC). Macrophages isolated from footpad lesions of BALB/c mice infected with Leishmania (L.) amazonensis were incubated with MoAb ST-3 and, by indirect immunofluorescence, labeling was only detected on the parasite, whereas no fluorescence was observed on the surface of the infected macrophages, indicating that these glycosphingolipid antigens are not acquired from the host cell but synthesized by the amastigote. Intravenous administration of 125I-labeled ST-3 antibody to infected BALB/c mice showed that MoAb ST-3 accumulated significantly in the footpad lesions in comparison to blood and other tissues

Straus A.H.; Valero V.B.; Takizawa C.M.; Levery S.B.; Toledo M.S.; Suzuki E.; Salyan M.E.K.; Hakomori S.; Barbieri C.L.; Takahashi H.K.

1997-01-01

103

Effects of (-) mammea A/BB isolated from Calophyllum brasiliense leaves and derivatives on mitochondrial membrane of Leishmania amazonensis.  

Science.gov (United States)

We have previously demonstrated antileishmanial activity on Leishmania amazonensis of the natural (1-2), synthetic (7) and derivatives of coumarin (-) mammea A/BB (3-6) isolated from the dichloromethane extract of Calophyllum brasiliense leaves. The aim of the present study was to evaluate morphological and ultrastructural alterations in Leishmania amazonensis induced by these compounds. In promastigote forms, all seven compounds produced significant morphological and ultrastructural alterations, as revealed by scanning and transmission electron microscopy. The compound 5,7-dihydroxy-8-(2-methylbutanoyl)-6-(3-methylbutyl)-4-phenyl-chroman-2-one (3), the most active antileishmanial with LD?? of 0.9 ?M), induced cell shrinkage and a rounded appearance of the cells. Parasites incubated in the presence of compound (3) showed ultrastructural changes, such as the appearance of mitochondrial swelling with a reduction in the density of the mitochondrial matrix and the presence of vesicles inside the mitochondrion, indicating damage and significant change in this organelle; abnormal chromatin condensation, alterations in the nuclear envelope, intense atypical cytoplasmic vacuolization, and the appearance of autophagic vacuoles were also observed. In addition, the compound (3) may be acting to depolarize the mitochondrial membrane potential of the cells, leading to death of the parasite. PMID:22285848

Brenzan, M A; Santos, A O; Nakamura, C V; Filho, B P Dias; Ueda-Nakamura, T; Young, M C M; Côrrea, A G; Júnior, J Alvim; Morgado-Díaz, J A; Cortez, D A G

2012-01-28

104

Effects of (-) mammea A/BB isolated from Calophyllum brasiliense leaves and derivatives on mitochondrial membrane of Leishmania amazonensis.  

UK PubMed Central (United Kingdom)

We have previously demonstrated antileishmanial activity on Leishmania amazonensis of the natural (1-2), synthetic (7) and derivatives of coumarin (-) mammea A/BB (3-6) isolated from the dichloromethane extract of Calophyllum brasiliense leaves. The aim of the present study was to evaluate morphological and ultrastructural alterations in Leishmania amazonensis induced by these compounds. In promastigote forms, all seven compounds produced significant morphological and ultrastructural alterations, as revealed by scanning and transmission electron microscopy. The compound 5,7-dihydroxy-8-(2-methylbutanoyl)-6-(3-methylbutyl)-4-phenyl-chroman-2-one (3), the most active antileishmanial with LD?? of 0.9 ?M), induced cell shrinkage and a rounded appearance of the cells. Parasites incubated in the presence of compound (3) showed ultrastructural changes, such as the appearance of mitochondrial swelling with a reduction in the density of the mitochondrial matrix and the presence of vesicles inside the mitochondrion, indicating damage and significant change in this organelle; abnormal chromatin condensation, alterations in the nuclear envelope, intense atypical cytoplasmic vacuolization, and the appearance of autophagic vacuoles were also observed. In addition, the compound (3) may be acting to depolarize the mitochondrial membrane potential of the cells, leading to death of the parasite.

Brenzan MA; Santos AO; Nakamura CV; Filho BP; Ueda-Nakamura T; Young MC; Côrrea AG; Júnior JA; Morgado-Díaz JA; Cortez DA

2012-02-01

105

Neutrophils have a protective role during early stages of Leishmania amazonensis infection in BALB/c mice.  

UK PubMed Central (United Kingdom)

Neutrophils are involved in early stages of immune responses to pathogens. Here, we investigated the role of neutrophils during the establishment of Leishmania amazonensis infection in BALB/c and C57BL/6 mice. First, we showed an accumulation of neutrophils between 6 and 24 hours post-infection, followed by a reduction in neutrophil numbers after 72 hours. Next, we depleted neutrophils prior to infection using RB6-8C5 or 1A8 mAb. Neutrophil depletion led to faster lesion development, increased parasite numbers and higher arginase activity during the first week of infection in BALB/c mice, but not in C57BL/6 mice. Increased susceptibility was accompanied by augmented levels of anti-L. amazonensis IgG and increased production of IL-10 and IL-17. Because IL-10 is a mediator of susceptibility to Leishmania infection, we blocked IL-10 signaling in neutrophil-depleted mice using anti-IL-10R. Interestingly, inhibition of IL-10 signaling abrogated the increase in parasite loads observed in neutrophil-depleted mice, suggesting that parasite proliferation is at least partially mediated by IL-10. Additionally, we tested the effect of IL-17 in inflammatory macrophages and observed that IL-17 increased arginase activity and favored parasite growth. Taken together, our data indicate that neutrophils control parasite numbers and limit lesion development during the first week of infection in BALB/c mice. This article is protected by copyright. All rights reserved.

Sousa LM; Carneiro MB; Resende ME; Mello PS; Martins LS; Dos Santos LM; Vaz LG; Mosser DM; Oliveira MA; Vieira LQ

2013-09-01

106

The T-cell anergy induced by Leishmania amazonensis antigens is related with defective antigen presentation and apoptosis  

Directory of Open Access Journals (Sweden)

Full Text Available Leishmania amazonensis is the main agent of diffuse cutaneous leishmaniasis, a disease associated with anergic immune responses. In this study we show that the crude antigen of Leishmania amazonensis (LaAg) but not L. braziliensis promastigotes (LbAg) contains substances that suppress mitogenic and spontaneous proliferative responses of T cells. The suppressive substances in LaAg are thermoresistant (100ºC/1h) and partially dependent on protease activity. T cell anergy was not due to a decreased production of growth factors as it was not reverted by addition of exogenous IL-2, IL-4, IFN-gamma or IL-12. LaAg did not inhibit anti-CD3-induced T cell activation, suggesting that anergy was due to a defect in antigen presentation. It was also not due to cell necrosis, but was accompanied by expressive DNA fragmentation in lymph node cells, indicative of apoptosis. Although pre-incubation of macrophages with LaAg prevented their capacity to present antigens, this effect was not due to apoptosis of the former. These results suggest that the T cell anergy found in diffuse leishmaniasis may be the result of parasite antigen-driven apoptosis of those cells following defective antigen presentation.

Pinheiro Roberta O.; Pinto Eduardo F.; Benedito Alessandra B.; Lopes Ulisses G.; Rossi-Bergmann Bartira

2004-01-01

107

Therapeutic efficacy induced by the oral administration of Agaricus blazei Murill against Leishmania amazonensis.  

Science.gov (United States)

The development of therapeutic alternatives to treat leishmaniasis has received considerable attention. The present study aimed to investigate the efficacy of the Agaricus blazei Murill water extract (AbM) to treat BALB/c mice infected with Leishmania amazonensis. First, a dose-titration curve was performed. The most well-defined concentration able to induce the most effective results in the infected animals, considering a daily administration of the product, was that of 100 mg kg(-1) day(-1). In this context, the AbM was administered orally, beginning on day 0 up to 20 days postinfection. Additional animals were treated with amphotericin B (AmpB, 5 mg kg(-1) day(-1)) by peritoneal route for the same period of time, while the control group received distilled water. The animals were evaluated at 14 weeks post-infection, at which time the parasitological and immunological parameters were analyzed. Mice treated with the AbM presented a 60% reduction in the inflammation of infected footpads as compared to untreated control-infected mice. Moreover, in the treated mice, as compared to the untreated controls, approximately 60 and 66% reductions could be observed in the parasite burdens of the footpad and draining lymph nodes, respectively. In addition, no parasites could be detected in the spleen of treated mice at week 14 postinfection. These treated animals produced significantly higher levels of interferon gamma (IFN-?) and nitric oxide (NO), higher levels of parasite-specific IgG2a isotype antibodies, and lower levels of interleukin (IL)-4, and IL-10 in the spleen and lymph node cell cultures than did the controls. Differences could be observed by comparing animals treated with AbM to those treated with AmpB, as indicated by a significant reduction in tissue parasitism, higher levels of IFN-? and NO, and lower levels of IL-4 and IL-10, as well as by a decreased hepatic toxicity. In conclusion, the present study's data show that the A. blazei Murill water extract presents a high potential for the treatment of leishmaniasis, although additional studies on mice, as well as on other mammal hosts, are warranted in an attempt to determine this extract's true efficacy as compared to other known therapeutic products. PMID:22797606

Valadares, Diogo G; Duarte, Mariana C; Ramírez, Laura; Chávez-Fumagalli, Miguel A; Lage, Paula S; Martins, Vivian T; Costa, Lourena E; Ribeiro, Tatiana G; Régis, Wiliam C B; Soto, Manuel; Fernandes, Ana Paula; Tavares, Carlos A P; Coelho, Eduardo A F

2012-07-15

108

Therapeutic efficacy induced by the oral administration of Agaricus blazei Murill against Leishmania amazonensis.  

UK PubMed Central (United Kingdom)

The development of therapeutic alternatives to treat leishmaniasis has received considerable attention. The present study aimed to investigate the efficacy of the Agaricus blazei Murill water extract (AbM) to treat BALB/c mice infected with Leishmania amazonensis. First, a dose-titration curve was performed. The most well-defined concentration able to induce the most effective results in the infected animals, considering a daily administration of the product, was that of 100 mg kg(-1) day(-1). In this context, the AbM was administered orally, beginning on day 0 up to 20 days postinfection. Additional animals were treated with amphotericin B (AmpB, 5 mg kg(-1) day(-1)) by peritoneal route for the same period of time, while the control group received distilled water. The animals were evaluated at 14 weeks post-infection, at which time the parasitological and immunological parameters were analyzed. Mice treated with the AbM presented a 60% reduction in the inflammation of infected footpads as compared to untreated control-infected mice. Moreover, in the treated mice, as compared to the untreated controls, approximately 60 and 66% reductions could be observed in the parasite burdens of the footpad and draining lymph nodes, respectively. In addition, no parasites could be detected in the spleen of treated mice at week 14 postinfection. These treated animals produced significantly higher levels of interferon gamma (IFN-?) and nitric oxide (NO), higher levels of parasite-specific IgG2a isotype antibodies, and lower levels of interleukin (IL)-4, and IL-10 in the spleen and lymph node cell cultures than did the controls. Differences could be observed by comparing animals treated with AbM to those treated with AmpB, as indicated by a significant reduction in tissue parasitism, higher levels of IFN-? and NO, and lower levels of IL-4 and IL-10, as well as by a decreased hepatic toxicity. In conclusion, the present study's data show that the A. blazei Murill water extract presents a high potential for the treatment of leishmaniasis, although additional studies on mice, as well as on other mammal hosts, are warranted in an attempt to determine this extract's true efficacy as compared to other known therapeutic products.

Valadares DG; Duarte MC; Ramírez L; Chávez-Fumagalli MA; Lage PS; Martins VT; Costa LE; Ribeiro TG; Régis WC; Soto M; Fernandes AP; Tavares CA; Coelho EA

2012-10-01

109

Kinetoplastid membrane protein-11 is present in promastigotes and amastigotes of Leishmania amazonensis and its surface expression increases during metacyclogenesis  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Kinetoplastid membrane protein-11 (KMP-11), a protein present in all kinetoplastid protozoa, is considered a potential candidate for a leishmaniasis vaccine. A suitable leishmaniasis vaccine candidate molecule must be expressed in amastigotes, the infective stage for mammals. However, the expression of KMP-11 in Leishmania amastigotes has been a subject of controversy. We evaluated the expression of this molecule in logarithmic and stationary growth phase promastigotes, a (more) s well as in amastigotes, of Leishmania amazonensis by immunoblotting, flow cytometry and immunocytochemistry, using a monoclonal antibody against KMP-11. We found that KMP-11 is present in promastigotes and amastigotes. In both stages, the protein was found in association with membrane structures (at the cell surface, flagellar pocket and intracellular vesicles). More importantly, its surface expression is higher in amastigotes than in promastigotes and increases during metacyclogenesis. The increased expression of KMP-11 in metacyclic promastigotes, and especially in amastigotes, indicates a role for this molecule in the parasite relationship with the mammalian host. The presence of this molecule in amastigotes is consistent with the previously demonstrated immunoprotective capacity of vaccine prototypes based on the KMP-11-coding gene and the presence of humoral and cellular immune responses to KMP-11 in Leishmania-infected humans and animals.

Matos, Denise CS; Faccioli, Lanuza AP; Cysne-Finkelstein, Léa; Luca, Paula Mello De; Corte-Real, Suzana; Armôa, Geraldo RG; Lemes, Elezer Monte Blanco; Decote-Ricardo, Débora; Mendonça, Sergio CF

2010-05-01

110

Kinetoplastid membrane protein-11 is present in promastigotes and amastigotes of Leishmania amazonensis and its surface expression increases during metacyclogenesis  

Directory of Open Access Journals (Sweden)

Full Text Available Kinetoplastid membrane protein-11 (KMP-11), a protein present in all kinetoplastid protozoa, is considered a potential candidate for a leishmaniasis vaccine. A suitable leishmaniasis vaccine candidate molecule must be expressed in amastigotes, the infective stage for mammals. However, the expression of KMP-11 in Leishmania amastigotes has been a subject of controversy. We evaluated the expression of this molecule in logarithmic and stationary growth phase promastigotes, as well as in amastigotes, of Leishmania amazonensis by immunoblotting, flow cytometry and immunocytochemistry, using a monoclonal antibody against KMP-11. We found that KMP-11 is present in promastigotes and amastigotes. In both stages, the protein was found in association with membrane structures (at the cell surface, flagellar pocket and intracellular vesicles). More importantly, its surface expression is higher in amastigotes than in promastigotes and increases during metacyclogenesis. The increased expression of KMP-11 in metacyclic promastigotes, and especially in amastigotes, indicates a role for this molecule in the parasite relationship with the mammalian host. The presence of this molecule in amastigotes is consistent with the previously demonstrated immunoprotective capacity of vaccine prototypes based on the KMP-11-coding gene and the presence of humoral and cellular immune responses to KMP-11 in Leishmania-infected humans and animals.

Denise CS Matos; Lanuza AP Faccioli; Léa Cysne-Finkelstein; Paula Mello De Luca; Suzana Corte-Real; Geraldo RG Armôa; Elezer Monte Blanco Lemes; Débora Decote-Ricardo; Sergio CF Mendonça

2010-01-01

111

Immune and inflammatory responses to Leishmania amazonensis isolated from different clinical forms of human leishmaniasis in CBA mice  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Leishmania amazonensis causes different diseases depending on the host and parasitic virulence factors. In this study, CBA mice were infected with L. amazonensis isolates from patients with localized (Ba125), diffuse cutaneous (Ba276) or visceral leishmaniasis (Ba109). Mice infected with Ba125 and Ba276 progressed rapidly and lesions displayed an infiltrate rich in parasitized macrophages and were necrotic and ulcerated. Ba109 induced smaller lesions and a mixed inflammat (more) ory infiltrate without necrosis or ulceration. Ba109 induced an insidious disease with lower parasite load in CBA mice, similar to human disease. Levels of IFN-?, IL-4 and IL-10 did not differ among the groups. Because all groups were unable to control the infection, expression of IL-4 associated with low production of IFN-? in the early phase of infection may account for susceptibility, but others factors may contribute to the differences observed in inflammatory responses and infection progression. Evaluation of some parasitic virulence factors revealed that Ba276 exhibits higher ecto-ADPase and 5'-nucleotidase activities compared to the Ba109 and Ba125 strains. Both Ba276 and Ba125 had higher arginase activity in comparison to Ba109. Finally, these data suggest that the differences in enzyme activities among parasites can account for differences in host inflammatory responses and infection progression.

Souza, Valderes L de; Veras, Patrícia ST; Welby-Borges, Marcus; Silva, Tânia MC; Leite, Bruna R; Ferraro, Rodrigo B; Meyer-Fernandes, José R; Barral, Aldina; Costa, Jackson Mauricio Lopes; Freitas, Luiz AR de

2011-02-01

112

Construcción de una biblioteca genómica de Leishmania amazonensis y su expresión en músculo de ratones BALB/c  

Directory of Open Access Journals (Sweden)

Full Text Available Se construyó una biblioteca genómica de Leishmania amazonensis mediante el vector pcDNA3, con promotor de expresión en células eucariotas, con el objetivo de contribuir a la aplicación de la tecnología de inmunización con ácidos nucleicos en la leishmaniosis. Para demostrar la expresión de la genoteca en el músculo de ratones inmunizados con esta, se realizó la técnica de inmunofluorescencia indirecta. Como anticuerpo primario se utilizó una mezcla de sueros con alto título antileishmania, de una zona donde predomina la infección con L. braziliensis. Se obtuvo una biblioteca con 80 % de clones recombinantes. Se demostró la expresión de determinantes antigénicos en el músculo de ratones BALB/c inmunizados, según resultados de la inmunofluorescencia.A genomic library of Leishaminia amazonensis was built through a pcDNA3 vector, with expression promoter in eukaryot cells, to contribute to the application of immunization technology with nucleic acids in leishmaniasis. To show the expression genomic library in the muscles of mice immunized with it, the indirect immunofluoresce technique was used. A mix of sera with high antileishmania titers from an area where L.braziliensis infection is predominant was used as primary antibody. A library of 80% recombinant clones was obtained. Antigen determinant expression was confirmed in immunized BALB/c mice´s muscles, according to the results of immunofluorescence testing.

Ana Margarita Montalvo Álvarez; Esteban Alberti Amador; Marta M. González Elías; Rocío García Miniet; María E. Sarmiento García; Armando Acosta Domínguez

2001-01-01

113

Construcción de una biblioteca genómica de Leishmania amazonensis y su expresión en músculo de ratones BALB/c  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Se construyó una biblioteca genómica de Leishmania amazonensis mediante el vector pcDNA3, con promotor de expresión en células eucariotas, con el objetivo de contribuir a la aplicación de la tecnología de inmunización con ácidos nucleicos en la leishmaniosis. Para demostrar la expresión de la genoteca en el músculo de ratones inmunizados con esta, se realizó la técnica de inmunofluorescencia indirecta. Como anticuerpo primario se utilizó una mezcla de sueros (more) con alto título antileishmania, de una zona donde predomina la infección con L. braziliensis. Se obtuvo una biblioteca con 80 % de clones recombinantes. Se demostró la expresión de determinantes antigénicos en el músculo de ratones BALB/c inmunizados, según resultados de la inmunofluorescencia. Abstract in english A genomic library of Leishaminia amazonensis was built through a pcDNA3 vector, with expression promoter in eukaryot cells, to contribute to the application of immunization technology with nucleic acids in leishmaniasis. To show the expression genomic library in the muscles of mice immunized with it, the indirect immunofluoresce technique was used. A mix of sera with high antileishmania titers from an area where L.braziliensis infection is predominant was used as primary (more) antibody. A library of 80% recombinant clones was obtained. Antigen determinant expression was confirmed in immunized BALB/c mice´s muscles, according to the results of immunofluorescence testing.

Montalvo Álvarez, Ana Margarita; Alberti Amador, Esteban; González Elías, Marta M.; García Miniet, Rocío; Sarmiento García, María E.; Acosta Domínguez, Armando

2001-12-01

114

Immune and inflammatory responses to Leishmania amazonensis isolated from different clinical forms of human leishmaniasis in CBA mice.  

Science.gov (United States)

Leishmania amazonensis causes different diseases depending on the host and parasitic virulence factors. In this study, CBA mice were infected with L. amazonensis isolates from patients with localized (Ba125), diffuse cutaneous (Ba276) or visceral leishmaniasis (Ba109). Mice infected with Ba125 and Ba276 progressed rapidly and lesions displayed an infiltrate rich in parasitized macrophages and were necrotic and ulcerated. Ba109 induced smaller lesions and a mixed inflammatory infiltrate without necrosis or ulceration. Ba109 induced an insidious disease with lower parasite load in CBA mice, similar to human disease. Levels of IFN-?, IL-4 and IL-10 did not differ among the groups. Because all groups were unable to control the infection, expression of IL-4 associated with low production of IFN-? in the early phase of infection may account for susceptibility, but others factors may contribute to the differences observed in inflammatory responses and infection progression. Evaluation of some parasitic virulence factors revealed that Ba276 exhibits higher ecto-ADPase and 5'-nucleotidase activities compared to the Ba109 and Ba125 strains. Both Ba276 and Ba125 had higher arginase activity in comparison to Ba109. Finally, these data suggest that the differences in enzyme activities among parasites can account for differences in host inflammatory responses and infection progression. PMID:21340351

Souza, Valderes L de; Veras, Patrícia S T; Welby-Borges, Marcus; Silva, Tânia M C; Leite, Bruna R; Ferraro, Rodrigo B; Meyer-Fernandes, José R; Barral, Aldina; Costa, Jackson Mauricio Lopes; de Freitas, Luiz A R

2011-02-01

115

In vitro and in vivo activity of meglumine antimoniate produced at Farmanguinhos-Fiocruz, Brazil, against Leishmania (Leishmania) amazonensis, L (L.) chagasi and L (Viannia) braziliensis  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The leishmanicidal activity of four batches of meglumine antimoniate, produced in Farmanguinhos-Fiocruz, Brazil (TAMs), was assessed and compared to Glucantime®-Aventis Pharma Ltda. Using the amastigote-like in vitro model, the active concentrations of Sb v varied from 10µg/ml to 300 µg/ml for L. (L.) chagasi and from 50µg/ml to 300µg/ml for L. (L.) amazonensis, with no statistically significant differences among the four batches of TAMs and Glucantime®. The inhibit (more) ory concentrations (IC50) determined by the amastigote-infected macrophage model for TAM01/03 and Glucantime® were, respectively: 26.3µg/ml and 127.6µg/ml for L. chagasi, 15.4µg /ml and 22.9µg/ml for L. amazonensis, and 12.1µg/ml and 24.2µg/ml for L. (V.) braziliensis. The activities of the four batches of TAMs were confirmed in an in vivo model by assessing, during eight weeks skin lesions caused by L. braziliensis in hamster that were treated with 20mg Sb v/Kg/day for 30 consecutive days. The meglumine antimoniate produced by Farmanguinhos was as effective as the reference drug, Glucantime®-Aventis, against three species of Leishmania that are of medical importance in Brazil.

Morais-Teixeira, Eliane de; Carvalho, Alcione S de; Costa, Jorge CS da; Duarte, Silvio L; Mendonça, Jorge S; Boechat, Núbia; Rabello, Ana

2008-06-01

116

In vitro and in vivo activity of meglumine antimoniate produced at Farmanguinhos-Fiocruz, Brazil, against Leishmania (Leishmania) amazonensis, L (L.) chagasi and L (Viannia) braziliensis  

Directory of Open Access Journals (Sweden)

Full Text Available The leishmanicidal activity of four batches of meglumine antimoniate, produced in Farmanguinhos-Fiocruz, Brazil (TAMs), was assessed and compared to Glucantime®-Aventis Pharma Ltda. Using the amastigote-like in vitro model, the active concentrations of Sb v varied from 10µg/ml to 300 µg/ml for L. (L.) chagasi and from 50µg/ml to 300µg/ml for L. (L.) amazonensis, with no statistically significant differences among the four batches of TAMs and Glucantime®. The inhibitory concentrations (IC50) determined by the amastigote-infected macrophage model for TAM01/03 and Glucantime® were, respectively: 26.3µg/ml and 127.6µg/ml for L. chagasi, 15.4µg /ml and 22.9µg/ml for L. amazonensis, and 12.1µg/ml and 24.2µg/ml for L. (V.) braziliensis. The activities of the four batches of TAMs were confirmed in an in vivo model by assessing, during eight weeks skin lesions caused by L. braziliensis in hamster that were treated with 20mg Sb v/Kg/day for 30 consecutive days. The meglumine antimoniate produced by Farmanguinhos was as effective as the reference drug, Glucantime®-Aventis, against three species of Leishmania that are of medical importance in Brazil.

Eliane de Morais-Teixeira; Alcione S de Carvalho; Jorge CS da Costa; Silvio L Duarte; Jorge S Mendonça; Núbia Boechat; Ana Rabello

2008-01-01

117

Leishmania amazonensis promastigotes induce and are killed by neutrophil extracellular traps.  

UK PubMed Central (United Kingdom)

Neutrophils are short-lived leukocytes that die by apoptosis, necrosis, and NETosis. Upon death by NETosis, neutrophils release fibrous traps of DNA, histones, and granule proteins named neutrophil extracellular traps (NETs), which can kill bacteria and fungi. Inoculation of the protozoan Leishmania into the mammalian skin causes local inflammation with neutrophil recruitment. Here, we investigated the release of NETs by human neutrophils upon their interaction with Leishmania parasites and NETs' ability to kill this protozoan. The NET constituents DNA, elastase, and histones were detected in traps associated to promastigotes by immunofluorescence. Electron microscopy revealed that Leishmania was ensnared by NETs released by neutrophils. Moreover, Leishmania and its surface lipophosphoglycan induced NET release by neutrophils in a parasite number- and dose-dependent manner. Disruption of NETs by DNase treatment during Leishmania-neutrophil interaction increased parasite survival, evidencing NETs' leishmanicidal effect. Leishmania killing was also elicited by NET-rich supernatants from phorbol 12-myristate 13-acetate-activated neutrophils. Immunoneutralization of histone during Leishmania-neutrophil interaction partially reverted Leishmania killing, and purified histone killed the parasites. Meshes composed of DNA and elastase were evidenced in biopsies of human cutaneous leishmaniasis. NET is an innate response that might contribute to diminish parasite burden in the Leishmania inoculation site.

Guimarães-Costa AB; Nascimento MT; Froment GS; Soares RP; Morgado FN; Conceição-Silva F; Saraiva EM

2009-04-01

118

Leishmania amazonensis promastigotes induce and are killed by neutrophil extracellular traps.  

Science.gov (United States)

Neutrophils are short-lived leukocytes that die by apoptosis, necrosis, and NETosis. Upon death by NETosis, neutrophils release fibrous traps of DNA, histones, and granule proteins named neutrophil extracellular traps (NETs), which can kill bacteria and fungi. Inoculation of the protozoan Leishmania into the mammalian skin causes local inflammation with neutrophil recruitment. Here, we investigated the release of NETs by human neutrophils upon their interaction with Leishmania parasites and NETs' ability to kill this protozoan. The NET constituents DNA, elastase, and histones were detected in traps associated to promastigotes by immunofluorescence. Electron microscopy revealed that Leishmania was ensnared by NETs released by neutrophils. Moreover, Leishmania and its surface lipophosphoglycan induced NET release by neutrophils in a parasite number- and dose-dependent manner. Disruption of NETs by DNase treatment during Leishmania-neutrophil interaction increased parasite survival, evidencing NETs' leishmanicidal effect. Leishmania killing was also elicited by NET-rich supernatants from phorbol 12-myristate 13-acetate-activated neutrophils. Immunoneutralization of histone during Leishmania-neutrophil interaction partially reverted Leishmania killing, and purified histone killed the parasites. Meshes composed of DNA and elastase were evidenced in biopsies of human cutaneous leishmaniasis. NET is an innate response that might contribute to diminish parasite burden in the Leishmania inoculation site. PMID:19346483

Guimarães-Costa, Anderson B; Nascimento, Michelle T C; Froment, Giselle S; Soares, Rodrigo P P; Morgado, Fernanda N; Conceição-Silva, Fátima; Saraiva, Elvira M

2009-04-03

119

Ocular experimental leishmaniasis in C57BL/10 and BALB/c mice induced by Leishmania amazonensis infection.  

UK PubMed Central (United Kingdom)

There are few studies on human ocular leishmaniasis found in the literature. The purpose of this study was to describe experimental ocular leishmaniasis, caused by Leishmania amazonensis evaluating two different infection routes: intravitreal and instillation in C57BL/10 and BALB/c mice. In this work all animals presented low anti-Leishmania IgM and IgG titers regardless of the infection route or mouse strain. The histopathological eye analysis showed that the mice inoculated by the intravitreal route developed more severe lesions, presenting parasites in the anterior region of the eye 60 days after infection. The C57BL/10 mice presented cells containing parasitophorous vacuoles associated with pigmented cells and inflammatory infiltrate, which included mast cells. Ninety days after infection no parasites could be found in either mouse strain, which led us to hypothesize that parasites had been eliminated. In this context, we show that both intravitreal and instillation routes were effective in promoting ocular leishmaniasis infections in C57BL/10 and BALB/c mice. There were no differences in the parasite infection between the two mouse models and it mimicked the ocular lesions described in symptomatic dogs in endemic areas of visceral leishmaniasis.

Calabrese KS; Silva LS; Hardoim DJ; Souza CS; Abreu-Silva AL

2013-02-01

120

Flagellates in the Malpighian tubules of laboratory-bred Lutzomyia longipalpis fed on a hamster experimentally infected with Leishmania mexicana amazonensis  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Encontramos abundantes promastigotas nos tubos de Malpighi, além do tubo digestivo, em elevada proporção de fêmeas de Lutzomyia longipalpis experimentalmente infectadas em hamster inoculado com Leishmania mexicana amazonensis. Abstract in english As a preparatory stage for a study aiming at identifying the species and subspecies of local Leishmania in naturally infected sandflies through immunoradiometric assay with monoclonal antibodies, we tried to obtain experimental infections of phlebotomines with well characterized stocks of parasites, in order to test the effectiveness of the method.

Rangel, Elizabeth Ferreira; Deane, Leonidas M.; Grimaldi Filho, Gabriel; Souza, Nataly A. de; Wermelinger, Eduardo D.; Barbosa, André F.

1985-09-01

 
 
 
 
121

BnSP-7 toxin, a basic phospholipase A2 from Bothrops pauloensis snake venom, interferes with proliferation, ultrastructure and infectivity of Leishmania (Leishmania) amazonensis.  

UK PubMed Central (United Kingdom)

This paper reports the effects of BnSP-7 toxin, a catalytically inactive phospholipase A2 from Bothrops pauloensis snake venom, on Leishmania (Leishmania) amazonensis. BnSP-7 presented activity against promastigote parasite forms both in the MTT assay, with IC50 of 58.7 ?g mL(-1) of toxin, and a growth curve, inhibiting parasite proliferation 60-70% at concentrations of 50-200 ?g mL(-1) of toxin 96 h after treatment. Also, the toxin presented effects on amastigotes, reducing parasite viability by 50% at 28.1 ?g mL(-1) and delaying the amastigote-promastigote differentiation process. Ultrastructural studies showed that BnSP-7 caused severe morphological changes in promastigotes such as mitochondrial swelling, nuclear alteration, vacuolization, acidocalcisomes, multiflagellar aspects and a blebbing effect in the plasma membrane. Finally, BnSP-7 interfered with the infective capacity of promastigotes in murine peritoneal macrophages, causing statistically significant infectivity-index reductions (P < 0.05) of 20-35%. These data suggest that the BnSP-7 toxin is an important tool for the discovery of new parasite targets that can be exploited to develop new drugs for treating leishmaniasis.

Nunes DC; Figueira MM; Lopes DS; De Souza DL; Izidoro LF; Ferro EA; Souza MA; Rodrigues RS; Rodrigues VM; Yoneyama KA

2013-06-01

122

Lutzomyia reducta Feliciangeli et al., 1988, a host of Leishmania amazonensis, sympatric with two other members of the Flaviscutellata complex in southern Amazonas and Rondônia, Brazil (Diptera: Psychodidae) Lutzomyia reducta Feliciangeli et al., 1988 um hospedeiro de Leishmania amazonensis, simpátrico com duas outras espécies do complexo flaviscutellata no sul do Amazonas e Rondônica, Brasil (Diptera: Psychodidae)  

Directory of Open Access Journals (Sweden)

Full Text Available A member of the Lutzomyia flaviscutellata complex from Rondônia and southern Amazonas States, Brazil, is so close to the Venezuelan Lutzomyia olmeca recuta Feliciangeli et al., 1988, that it is regarded as belonging to the same species. Since this phlebotomine co-extis with L. olmeca nociva in Brazil, the subspecific status of the former is untenable and is rased to specific rank, as Lutzomyia reducta. The Brazilian material is described and illustrated, and compared with specimens of L. o. nociva and L. flaviscutellata from the same area. Keys to the known taxa of the flaviscutellata complex are presented. Leishmania amazonensis was isolated from one heavily infected specimen of L. reducta, making this the third species of the flaviscutellata complex to be implicated as a vector of this parasite in Brazil. The relative abundance of the three sympatric flaviscutellata complex species varies locally and appears to be related to soil drainage. L. reducta constituted about 25% if all phlebotomines captured in Disney traps at poorly drained and well drained site, but appears not to coloniza areas subject to periodic flooding. L. olmeca nociva was restricted to poorly drained areas not subject to flooding, whereas L. flaviscutellata was ubiquitous L. reducta has never been detected north of the Amazon river in Brazil, but absence of recosrds from western and northwestern Amazonas State may reflect lack of collecting in these areas.Um flebotomíneo do complexo Lutzomyia flaviscutellata, de Rondônia e sul do Amazonas, Brasil é tão parecido com Lutzomyia olmeca reducta, que é considerado como sendo da mesma espécie. Este flebotomíneo ocorre junto com L. olmeca nociva, portanto o nome é emendado para o nível de espécie, como Lutzomyia reducta. O material do Brasil é descrito e ilustrado, e comparado com exemplares de L. o. nociva e L. flaviscutellata da mesma área. Chaves para as espécies e subespécies do complexo flaviscutellata são incluídas. Leishmania amazonensis foi isolada em um exemplar de L. reducta altamente infectado, tornando esta espécie a terceira a ser implicada como vetor desta leishmania no Brasil. A abundância relativa das três espécies simpátricas do complexo flaviscutellata varia em escala local e aparenta ter relação com a drenagem do solo. L. reducta constituiu cerca de 25% dos flebotomíneos capturados em armadilhas Disney em locais mal e bem drenados, porém não foi encontrada em locais sujeitos a inundações. L. olmeca nociva era restrita às áreas mal drenadas não sujeitas a inundações, enquanto L. flaviscutellata foi capturada neste dois ambientes e também numa área periodicamente inundada. L. reducta não tem sido assinalada ao norte do Rio Amazonas no Brasil, porém a ausência de registros do oeste e noroeste do Estado do Amazonas possa refletri a falta de levantamento nestas áreas.

R. A. Freitas; T. V. Barrett; R. D. Naiff

1989-01-01

123

Papel de la vacuola parasitófora de macrófagos de ratón infectados por Leishmania amazonensis en la adquisición de moléculas/ Role of the parasitophorous vacuole of murine macrophages infected with Leishmania amazonensis in molecule acquisition  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Introducción. Leishmania son parásitos intracelulares de macrófagos, confinados en compartimentos denominados vacuolas parasitóforas. La permeabilidad de este compartimento depende de su interacción con el tráfico vesicular y transportadores presentes en su membrana. Objetivo. En este trabajo se estudió la permeabilidad de la membrana de la vacuola parasitófora en la línea celular J774.A1 infectada con Leishmania amazonensis, in situ y en compartimentos aislados. (more) Materiales y métodos. El aislamiento de vacuolas parasitóforas se hizo por gradiente de densidad. La permeabilidad de la membrana de estas se valoró por distribución de sondas fluorescentes y electrofisiología. Para establecer indirectamente el transporte de protones se usó naranja de acridina. La presencia de transportadores ABC sensibles a probenecid se estableció con amarillo lucifer y calceína. Por primera vez con la técnica de patch-clamp se registraron corrientes en la membrana de este compartimento aislado. Resultados. La vacuola parasitófora colorea de rojo con naranja de acridina indicando un pH ácido. Concentra amarillo lucifer a través de un transportador sensible a probenecid, pero excluye la sonda calceína. Vacuolas aisladas se marcan de rojo con naranja de acridina y concentran amarillo lucifer a través de un transportador sensible a probenecid. Estas vacuolas excluyeron calceína y presentaron en su membrana una corriente iónica que se activa a diferencias de potencial cercanas a 60 mV, con una conductancia de 46 ± 3 pS. Conclusiones. Se pueden aislar vacuolas parasitóforas con propiedades de permeabilidad que preservan mecanismos de transporte similares a los encontrados in situ. Se registra por primera vez la presencia de una corriente iónica poco selectiva en la membrana de este compartimiento. Abstract in english Introduction. Leishmania are intracellular parasites of macrophages, confined into compartments known as parasitophorous vacuoles. The permeability of this compartment depends on its interaction with the endocytic pathway and transport proteins present on its membrane. Objective. The membrane permeability of the parasitophorous vacuole was studied in J774.A1- macrophage like cells infected with Leishmania amazonensis, in situ and on isolated compartments. Materials and me (more) thods. The parasitophorous vacuoles were isolated by density gradients. Fluorescent probe distribution and electrophysiological recordings were used to determine parasitophorous vacuole membrane permeability. Proton transport was evaluated indirectly by acridine orange staining. Probenecid sensitive ABC transporters were detected using the fluorescent probes lucifer yellow and calcein. For the first time ion currents were recorded on the membrane of isolated parasitophorous vacuoles using the patch clamp technique. Results. The parasitophorous vacuole stains red with acridine orange indicating an acidic compartment. It concentrates lucifer yellow by means of a probenecid sensitive transporter but excludes calcein. Isolated vacuoles stained red with acridine orange and concentrated lucifer yellow by means of a probenecid sensitive transporter. These vacuoles excluded calcein and showed an ion current in their membrane which is activated at potentials close to 60 mV with a mean conductance of 46 ± 3 pS. Conclusions. Isolated parasitophorous vacuoles with permeability properties preserving transport mechanisms similar to those found in situ can be purified. A poorly selective ion current on the parasitophorous vacuole membrane is reported for the first time.

Cortázar, Tania M; Hernández, Joselín; Echeverry, María Clara; Camacho, Marcela

2006-10-01

124

Role of Natural Killer Cells in Modulating Dendritic Cell Responses to Leishmania amazonensis Infection?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The importance of the interaction between natural killer (NK) cells and dendritic cells (DCs) in the expansion of antiviral and antitumor immune responses is well-documented; however, limited information on DC-NK cell interaction during parasitic infections is available. Given that some Leishmania p...

Sanabria, Mayra X. Hernandez; Vargas-Inchaustegui, Diego A.; Xin, Lijun; Soong, Lynn

125

Leishmania amazonensis promastigotes induce and are killed by neutrophil extracellular traps  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Neutrophils are short-lived leukocytes that die by apoptosis, necrosis, and NETosis. Upon death by NETosis, neutrophils release fibrous traps of DNA, histones, and granule proteins named neutrophil extracellular traps (NETs), which can kill bacteria and fungi. Inoculation of the protozoan Leishmania...

Guimarães-Costa, Anderson B.; Nascimento, Michelle T. C.; Froment, Giselle S.; Soares, Rodrigo P. P.; Morgado, Fernanda N.

126

In vitro initial immune response against Leishmania amazonensis infection is characterized by an increased production of IL-10 and IL-13  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The initial encounter of Leishmania with its host's immune system is important in the outcome of infection. Previous studies have shown that PBMCs from healthy volunteers (HV) exposed to Leishmania differ in IFN-? production. We have expanded such observations evaluating the profile and kinetics of cytokines (IFN-?, IL-12p70, IL-10, IL-13), chemokines (CCL5, CCL3, CCL4, CXCL10), and chemokine receptors (CCR1,CCR5, CXCR3, CCR4) in vitro L. amazonensis-stimulated (more) of HV's PBMCs. HVs were divided in groups of high (HR) or low (LR) IFN-? responders. In both groups, HR and LR, after L. amazonensis infection there was a predominance of IL-10 and IL-13 over IFN-? production, while IL-12 was produced in similar amount. Regarding chemokines, a more striking difference was observed for CCL3 expression that was lower at 12 hours and 48 hours post infection in LR than in HR. Interestingly, a downregulation of CCR5 and a greater expression of CCR4 were found in low IFN-? responders. These data suggest that early after L. amazonensis infection there is a cytokine milieu dominated by IL-13 and IL-10, and despite of this environment, IFN-? is produced, supporting the complexity of the response. It is noteworthy that the pattern of immune response is mounted in first hours after Leishmania stimulation, with the definition of the differentiation of Th1 versus Th2 cells. It remains to be determined if such an in vitro difference has an in vivo counterpart in terms of susceptibility to infection

Coêlho, Zirlane Castelo B; Teixeira, Maria Jania; Mota, Erika Freitas; Frutuoso, Mércia Sindeaux; Silva, João Santana da; Barral, Aldina; Barral-Netto, Manoel; Pompeu, Margarida Maria L

2010-10-01

127

In vitro initial immune response against Leishmania amazonensis infection is characterized by an increased production of IL-10 and IL-13  

Directory of Open Access Journals (Sweden)

Full Text Available The initial encounter of Leishmania with its host's immune system is important in the outcome of infection. Previous studies have shown that PBMCs from healthy volunteers (HV) exposed to Leishmania differ in IFN-? production. We have expanded such observations evaluating the profile and kinetics of cytokines (IFN-?, IL-12p70, IL-10, IL-13), chemokines (CCL5, CCL3, CCL4, CXCL10), and chemokine receptors (CCR1,CCR5, CXCR3, CCR4) in vitro L. amazonensis-stimulated of HV's PBMCs. HVs were divided in groups of high (HR) or low (LR) IFN-? responders. In both groups, HR and LR, after L. amazonensis infection there was a predominance of IL-10 and IL-13 over IFN-? production, while IL-12 was produced in similar amount. Regarding chemokines, a more striking difference was observed for CCL3 expression that was lower at 12 hours and 48 hours post infection in LR than in HR. Interestingly, a downregulation of CCR5 and a greater expression of CCR4 were found in low IFN-? responders. These data suggest that early after L. amazonensis infection there is a cytokine milieu dominated by IL-13 and IL-10, and despite of this environment, IFN-? is produced, supporting the complexity of the response. It is noteworthy that the pattern of immune response is mounted in first hours after Leishmania stimulation, with the definition of the differentiation of Th1 versus Th2 cells. It remains to be determined if such an in vitro difference has an in vivo counterpart in terms of susceptibility to infection

Zirlane Castelo B Coêlho; Maria Jania Teixeira; Erika Freitas Mota; Mércia Sindeaux Frutuoso; João Santana da Silva; Aldina Barral; Manoel Barral-Netto; Margarida Maria L Pompeu

2010-01-01

128

Lutzomyia reducta Feliciangeli et al., 1988, a host of Leishmania amazonensis, sympatric with two other members of the Flaviscutellata complex in southern Amazonas and Rondônia, Brazil (Diptera: Psychodidae)/ Lutzomyia reducta Feliciangeli et al., 1988 um hospedeiro de Leishmania amazonensis, simpátrico com duas outras espécies do complexo flaviscutellata no sul do Amazonas e Rondônica, Brasil (Diptera: Psychodidae)  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Um flebotomíneo do complexo Lutzomyia flaviscutellata, de Rondônia e sul do Amazonas, Brasil é tão parecido com Lutzomyia olmeca reducta, que é considerado como sendo da mesma espécie. Este flebotomíneo ocorre junto com L. olmeca nociva, portanto o nome é emendado para o nível de espécie, como Lutzomyia reducta. O material do Brasil é descrito e ilustrado, e comparado com exemplares de L. o. nociva e L. flaviscutellata da mesma área. Chaves para as espécies e (more) subespécies do complexo flaviscutellata são incluídas. Leishmania amazonensis foi isolada em um exemplar de L. reducta altamente infectado, tornando esta espécie a terceira a ser implicada como vetor desta leishmania no Brasil. A abundância relativa das três espécies simpátricas do complexo flaviscutellata varia em escala local e aparenta ter relação com a drenagem do solo. L. reducta constituiu cerca de 25% dos flebotomíneos capturados em armadilhas Disney em locais mal e bem drenados, porém não foi encontrada em locais sujeitos a inundações. L. olmeca nociva era restrita às áreas mal drenadas não sujeitas a inundações, enquanto L. flaviscutellata foi capturada neste dois ambientes e também numa área periodicamente inundada. L. reducta não tem sido assinalada ao norte do Rio Amazonas no Brasil, porém a ausência de registros do oeste e noroeste do Estado do Amazonas possa refletri a falta de levantamento nestas áreas. Abstract in english A member of the Lutzomyia flaviscutellata complex from Rondônia and southern Amazonas States, Brazil, is so close to the Venezuelan Lutzomyia olmeca recuta Feliciangeli et al., 1988, that it is regarded as belonging to the same species. Since this phlebotomine co-extis with L. olmeca nociva in Brazil, the subspecific status of the former is untenable and is rased to specific rank, as Lutzomyia reducta. The Brazilian material is described and illustrated, and compared wit (more) h specimens of L. o. nociva and L. flaviscutellata from the same area. Keys to the known taxa of the flaviscutellata complex are presented. Leishmania amazonensis was isolated from one heavily infected specimen of L. reducta, making this the third species of the flaviscutellata complex to be implicated as a vector of this parasite in Brazil. The relative abundance of the three sympatric flaviscutellata complex species varies locally and appears to be related to soil drainage. L. reducta constituted about 25% if all phlebotomines captured in Disney traps at poorly drained and well drained site, but appears not to coloniza areas subject to periodic flooding. L. olmeca nociva was restricted to poorly drained areas not subject to flooding, whereas L. flaviscutellata was ubiquitous L. reducta has never been detected north of the Amazon river in Brazil, but absence of recosrds from western and northwestern Amazonas State may reflect lack of collecting in these areas.

Freitas, R. A.; Barrett, T. V.; Naiff, R. D.

1989-09-01

129

Study of ionizing radiation as a tool for select promastigotes forms of Leishmania Amazonensis, and the megalomaniac response in experimental models  

International Nuclear Information System (INIS)

Actually, millions of people around the globe are under the risk of infection by a protozoan transmitted by a bit of a sand fly. This parasite is a Leishmania spp. This causes a wide spectrum disease, since a cutaneous disease to a visceral one. The cutaneous form is the major clinical manifestation (above 90%). The ionizing radiation, produced in a 60Co font, had being successes used to promote physical-chemical transformations on different protozoan, including Leishmania spp. In previous work was determined that promastigotes forms of Leishmania amazonensis, irradiated with different doses of radiation, lost their viability maintaining, however, their immunogenicity. In this work, was studied the use of ionizing radiation as a tool for selection of meta cyclic forms of the parasite in axenic culture, for a possible efficient irradiated immuno gene production. Our results shown that cultures irradiated with 400 Gy of gamma irradiation, has 75% of metacyclic form, which are capable to produce, in vitro, an infection that is similar the natural occurrence. These irradiated parasites have their internal cellular structure modified, maintaining their external structure intact. Susceptible strain of mice immunized with leishmania irradiated with different doses had high immunoglobulin production, and maintained this production after the challenge with naive parasites. In other strains this default was similar, however in lower titles. Immunodeficient mice didn't produce immunoglobulin nor on the immunization or on the challenge. (author)

2006-01-01

130

Interferon-gamma is required for the late but not early control of Leishmania amazonensis infection in C57Bl/6 mice  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The critical role of interferon-gamma (IFN-g) in the resistance of C57Bl/6 mice to Leishmania major is widely established but its role in the relative resistance of these animals to L. amazonensis infection is still not clear. In this work we use C57Bl/6 mice congenitally deficient in the IFN-g gene (IFN-g KO) to address this issue. We found that IFN-g KO mice were as resistant as their wild-type (WT) counterparts at least during the first two months of infection. Afterwa (more) rds, whereas WT mice maintained lesion growth under control, IFN-g KO mice developed devastating lesions. At day 97 of infection, their lesions were 9-fold larger than WT controls, concomitant with an increased parasite burden. At this stage, lesion-draining cells from IFN-g KO mice had impaired capacity to produce interleukin-12 (IL-12) and tumour necrosis factor-a in response to parasite antigens whereas IL-4 was slightly increased in comparison to infected WT mice. Together, these results show that IFN-g is not critical for the initial control of L. amazonensis infection in C57Bl/6 mice, but is essencial for the developmente of a protective Th1 type immune response in the later stages.

Pinheiro, Roberta Olmo; Rossi-Bergmann, Bartira

2007-02-01

131

Eugenia uniflora L. Essential Oil as a Potential Anti-Leishmania Agent: Effects on Leishmania amazonensis and Possible Mechanisms of Action.  

Science.gov (United States)

Eugenia uniflora L. is a member of the Myrtaceae family and is commonly known as Brazilian cherry tree. In this study, we evaluated the chemical composition of Eugenia uniflora L. essential oil (EuEO) by using gas chromatography-mass spectrometry (GC-MS) and assessed its anti-Leishmania activity. We also explored the potential mechanisms of action and cytotoxicity of EuEO. Thirty-two compounds were identified, which constituted 92.65% of the total oil composition. The most abundant components were sesquiterpenes (91.92%), with curzerene (47.3%), ? -elemene (14.25%), and trans- ? -elemenone (10.4%) being the major constituents. The bioactivity shown by EuEO against promastigotes (IC50, 3.04? ? g·mL(-1)) and amastigotes (IC50, 1.92? ? g·mL(-1)) suggested significant anti-Leishmania activity. In the cytotoxicity determination, EuEO was 20 times more toxic to amastigotes than to macrophages. Hemolytic activity was 63.22% at the highest concentration tested (400? ? g·mL(-1)); however, there appeared to be no toxicity at 50? ? g·mL(-1). While the data show that EuEO activity is not mediated by nitric oxide production, they do suggest that macrophage activation may be involved in EuEO anti-Leishmania activity, as evidenced by increases in both the phagocytic capacity and the lysosomal activity. More studies are needed to determine in vivo activity as well as additional mechanisms of the anti-Leishmania activity. PMID:23533469

Rodrigues, Klinger Antonio da Franca; Amorim, Layane Valéria; de Oliveira, Jamylla Mirck Guerra; Dias, Clarice Noleto; Moraes, Denise Fernandes Coutinho; Andrade, Eloisa Helena de Aguiar; Maia, Jose Guilherme Soares; Carneiro, Sabrina Maria Portela; Carvalho, Fernando Aécio de Amorim

2013-02-20

132

Eugenia uniflora L. Essential Oil as a Potential Anti-Leishmania Agent: Effects on Leishmania amazonensis and Possible Mechanisms of Action  

Science.gov (United States)

Eugenia uniflora L. is a member of the Myrtaceae family and is commonly known as Brazilian cherry tree. In this study, we evaluated the chemical composition of Eugenia uniflora L. essential oil (EuEO) by using gas chromatography-mass spectrometry (GC-MS) and assessed its anti-Leishmania activity. We also explored the potential mechanisms of action and cytotoxicity of EuEO. Thirty-two compounds were identified, which constituted 92.65% of the total oil composition. The most abundant components were sesquiterpenes (91.92%), with curzerene (47.3%), ?-elemene (14.25%), and trans-?-elemenone (10.4%) being the major constituents. The bioactivity shown by EuEO against promastigotes (IC50, 3.04??g·mL?1) and amastigotes (IC50, 1.92??g·mL?1) suggested significant anti-Leishmania activity. In the cytotoxicity determination, EuEO was 20 times more toxic to amastigotes than to macrophages. Hemolytic activity was 63.22% at the highest concentration tested (400??g·mL?1); however, there appeared to be no toxicity at 50??g·mL?1. While the data show that EuEO activity is not mediated by nitric oxide production, they do suggest that macrophage activation may be involved in EuEO anti-Leishmania activity, as evidenced by increases in both the phagocytic capacity and the lysosomal activity. More studies are needed to determine in vivo activity as well as additional mechanisms of the anti-Leishmania activity.

Amorim, Layane Valeria; de Oliveira, Jamylla Mirck Guerra; Dias, Clarice Noleto; Moraes, Denise Fernandes Coutinho; Andrade, Eloisa Helena de Aguiar; Maia, Jose Guilherme Soares; Carneiro, Sabrina Maria Portela; Carvalho, Fernando Aecio de Amorim

2013-01-01

133

Saliva of laboratory-reared Lutzomyia longipalpis exacerbates Leishmania (Leishmania) amazonensis infection more potently than saliva of wild-caught Lutzomyia longipalpis.  

UK PubMed Central (United Kingdom)

In order to compare the saliva effect from wild-caught and lab-reared L. longipalpis on the development of experimental cutaneous leishmaniasis, C57BL/6 mice were inoculated subcutaneously into the hind footpads with promastigotes of L. (L.) amazonensis plus salivary gland lysate from wild-caught (SGL-W) and lab-colonized (SGL-C) vectors. Lesion sizes were significantly larger in the mice infected with both saliva compared to mice infected with parasites alone; moreover, the lesions caused by parasite+SGL-C were significantly larger than the lesions caused by parasite+SGL-W. Histopathological morphometric studies regarding the acute phase of infections showed lower numbers of polymorphonuclear cells, greater numbers of mononuclear cells and parasites in SGL-C infected mice compared to SGL-W infected mice. In the chronic phase of infection, the number of mononuclear cells was lower and the number of parasites was greater in SGL-C infected mice than SGL-W infected mice. In vitro studies showed increased infection index of macrophages infected with parasites plus saliva compared to infection with parasites alone, with no difference between the saliva infection indices. SDS-PAGE gel for SGL-C and SGL-W showed differences in the composition and quantity of protein bands, determined by densitometry. These results call attention to the experimental saliva model, which shows exacerbation of infection caused by sandfly saliva.

Laurenti MD; Silveira VM; Secundino NF; Corbett CE; Pimenta PP

2009-09-01

134

Combining diagnostic procedures for the management of leishmaniasis in areas with high prevalence of Leishmania guyanensis/ Procedimentos diagnósticos combinados no manejo da leishmaniose em áreas com alta prevalência de Leishmania guyanensis  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese FUNDAMENTOS: O Amazonas corresponde a aproximadamente 40% dos casos de leishmaniose do país. Nós reportamos um estudo prospectivo com 180 pacientes de uma unidade de saúde que diagnostica 10% dos casos de leishmaniose da amazônia brasileira, com combinação de métodos diagnóstico em área de alta prevalência de Leishmania guyanensis. OBJETIVOS: avaliar métodos diagnóstico da Leishmaniose em área endêmica para Leishmania Amazonensis. MÉTODOS: Todos os paciente (more) s tiveram exame direto positivo com presença de amastigotas. Foi feita também biópsia cutânea, com realização de exame histológico, reação em cadeia da polimerase e cultura. RESULTADO: A reação em cadeia da polimerase detectou aproximadamente 90% de infecção quando foram usados duas técnicas de amplificação (mini-exon and HSP-70). A reação em cadeia da polimerase com HSP-70 foi mais sensível que a cultura associada à histopatologia. CONCLUSÃO: A melhor combinação foi a reação em cadeia da polimerase com histopatologia, com sensibilidade de 94%. A discrimanação das espécies causadoras de infecção humana nessa região mostrou Leishmania guyanensis em 94% dos casos e Leishmania brasiliensis em 6% Abstract in english BACKGROUND: The Amazon region corresponds to approximately 40% of the cases of leishmaniasis in Brazil. We report a prospective study with 180 patients conducted in a health care unit that diagnoses 10% of the cases of leishmaniasis in the Brazilian Amazon. The study addresses how a combination of procedures improves diagnosis in areas with high prevalence of Leishmania guyanensis. OBJECTIVES: to evaluate diagnostic methods in areas with high prevalence of Leishmania guya (more) nensis. METHODS: All subjects were amastigote-positive by direct microscopic examination of lesion scarifications. We conducted skin biopsy and histopathology, polymerase chain reaction and parasite cultivation. RESULTS: Polymerase chain reaction detected almost ninety percent of infections when two amplification protocols were used (mini-exon and HSP-70). HSP-70 specific polymerase chain reaction matched the sensitivity of parasite cultivation plus histopathology. CONCLUSION: The best combination was polymerase chain reaction plus histopathology, which increased diagnostic sensitivity to 94%. Species discrimination by polymerase chain reaction disclosed prevalence of human infections with Leishmania guyanensis of 94% and with Leishmania braziliensis of 6% for this region

Benicio, Ednelza de Almeida; Nunes Gadelha, Ellen Pricilla; Talhari, Anette; Silva Jr, Roberto Moreira da; Ferreira, Luis Carlos; Santos, Mayara Cristina Cordeiro dos; Mira, Marcelo Távora; Oliveira, Cintia Mara Costa de; Talhari, Carolina; Talhari, Sinésio; Machado, Paulo Roberto; Schriefer, Albert

2011-12-01

135

Acercamiento al estudio de la interacción y salida de Leishmania amazonensis en un modelo in vitro con macrófagos murinos de la línea celular J774a.1  

Directory of Open Access Journals (Sweden)

Full Text Available Los miembros del género Leishmania son parásitos intracelulares obligados, responsables de numerosas enfermedades humanas. Cumplen una parte muy importante de su ciclo de vida dentro del mamífero hospedero, en donde después de la fagocitosis por los macrófagos, los parásitos son confinados dentro de un compartimiento endolisosomal denominado vacuola parasitófora (VP), en el cual se replican siendo finalmente liberados infectando otros macrófagos y de esta forma ampliando la infección. Poco es el conocimiento que se tiene acerca de cómo ocurre el proceso de liberación de amastigotes de Leishmania que infectan macrófagos. Se sospecha que este mecanismo puede estar ocurriendo por un proceso de fusión de membranas. Mediciones de capacitanciade la membrana del macrófago y el uso de inhibidores de fusión de membranas soportan esta idea. El objetivo de este trabajo fue realizar seguimientos del ciclo infectivo de Leishmania amazonensis, para confirmar los hallazgos previos en cuanto a los tiempos en que probablemente puede estar ocurriendo la salida del amastigote. Además, se buscó determinar la viabilidad del parásito a lo largo del ciclo infectivo con el fin de comprender mejor la interacción hospedero-patógeno en el modelo in vitro; para ello se midió: viabilidad del parásito con tinción de diacetato de fluoresceína (DAF) y ioduro de propidio (IP), porcentaje de infección y número de parásitos por célula (p/c). Los resultados sugieren que la salida de los parásitos puede presentarse entre las 72 y 78 horas post infección (hpi) y entre las 96 y 120 hpi. Con los resultados de trabajos previos, y los datos presentados en este estudio, se ha propuesto que L. amazonensis puede presentar dos ciclos infectivos que se desarrollan durante cinco días en nuestras condiciones de cultivo in vitro. En las primeras 36-48 hpi el parásito se diferencia a amastigote. Después de su diferenciación comienza su división celular. Luego de las 72 hpi ocurre una disminución en el número de parásitos por célula (p/c) que ha sido relacionada con el momento en el cual podría salir el parásito de su célula hospedera. La recuperación del número de p/c a las 96 hpi y la disminución presentada a las 120 hpi sugieren la ocurrencia de un nuevo ciclo infectivo. La viabilidad del amastigote se vio afectada a medida que transcurrió la infección. Durante las primeras 24 hpi prácticamente todos los parásitos fueron viables (93,85%)y se observaron de color verde intenso dentro de las VP por marcaje con la sonda DAF. Entre el tercer y cuartodía se presentó una disminución significativa en la viabilidad de los parásitos p = 0,017 y p = 0,0097 respectivamente.Entre el tercer y quinto día post infección el cultivo en general se observó más deteriorado y se encontróuna cantidad considerable de macrófagos no viables, pero aún con parásitos viables en el interior de la VP. Estasobservaciones se han interpretado como competencia en el cultivo, lo que generaría déficit alimenticio,explicando la drástica disminución en la viabilidad general del cultivo. El descenso diario de un grupo de células infectadas podría ser la causa de la disminución en los porcentajes de infección. En este trabajo se desarrolló un método eficiente para marcar la membrana de macrófagos infectados con los análogos fluorescentes de fosfolípidos NBD-PE y RHO-PE con el fin de implementar la técnica FRET, y así evidenciar la fusión de una membrana no marcada como la de la VP, con una membrana previamente marcada como la del macrófago. Se estipuló que la concentración de 5 ?g/mL y 10 ?g/mL para las pruebas RHO-PE y NBD-PE respectivamente, puestas en contacto con macrófagos infectados en nuestras condiciones, fueron capaces de marcar clara y continuamente la membrana celular del 95,9% y 97,0% de los macrófagos. Asi mismo, con la menor formación de vesículas de la sonda comparada con otras concentraciones y con una permanencia del marcaje más halla de las cinco horas. Este marcaje constituye un gran a

León Cabrera Sonia Andrea; Camacho Navarro María Marcela

2006-01-01

136

Antigenic extracts of Leishmania braziliensis and Leishmania amazonensis associated with saponin partially protects BALB/c mice against Leishmania chagasi infection by suppressing IL-10 and IL-4 production  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english This study evaluated two vaccine candidates for their effectiveness in protecting BALB/c mice against Leishmania chagasiinfection. These immunogenic preparations were composed of Leishmania amazonensisor Leishmania braziliensisantigenic extracts in association with saponin adjuvant. Mice were given three subcutaneous doses of one of these vaccine candidates weekly for three weeks and four weeks later challenged with promastigotes of L. chagasiby intravenous injection. We (more) observed that both vaccine candidates induced a significant reduction in the parasite load of the liver, while the L. amazonensisantigenic extract also stimulated a reduction in spleen parasite load. This protection was associated with a suppression of both interleukin (IL)-10 and IL-4 cytokines by spleen cells in response to L. chagasiantigen. No change was detected in the production of IFN-?. Our data show that these immunogenic preparations reduce the type 2 immune response leading to the control of parasite replication.

Grenfell, Rafaella FQ; Marques-da-Silva, Eduardo A; Souza-Testasicca, Miriam C; Coelho, Eduardo AF; Fernandes, Ana Paula; Afonso, Luís Carlos C; Rezende, Simone A

2010-09-01

137

Vaccination of C57BL/10 mice against cutaneous leishmaniasis using killed promastigotes of different strains and species of Leishmania Vacinação de camundongos C57BL/10 contra leishmaniose com promastigotas mortas de diferentes cepas e espécies de Leishmania  

Directory of Open Access Journals (Sweden)

Full Text Available Antigenic extracts from five Leishmania stocks were used to vaccinate C57BL/10 mice. The Leishvacin® and PH8 monovalent vaccine yielded the highest IFN-gamma levels in the supernatants of spleen cell culture from vaccinated animals. Each single strain immunized group showed evidence of protective immunity six months after the challenge with promastigotes of Leishmania (Leishmania) amazonensis. No differences were detected between the vaccinated groups. It can be concluded that vaccines composed of single Leishmania stocks can provide protection to C57BL/10 mice against L. (L.) amazonensis infection.Estudos anteriores revelaram que uma vacina preparada com promastigotas mortas de cinco cepas de Leishmania pode induzir uma imunidade protetora para a leishmaniose tegumentar americana no homem e em modelos experimentais. Um dos problemas do uso desta vacina é a complexidade de sua composição e a necessidade de se incorporar diferentes cepas de Leishmania. Por esta razão, extratos antigênicos de cada uma das cinco cepas constituintes da vacina foram preparados e usados individualmente em estudos imunológicos com camundongos C57BL/10. A Leishvacin® e a vacina monovalente PH8 induziram os maiores níveis de Interferon-g (IFN-gama) detectado no sobrenadante de células esplênicas dos animais vacinados. Cada grupo imunizado com vacinas monovalentes desenvolveram uma imunidade protetora seis meses após a infecção desafio com promastigotas de Leishmania (Leishmania) amazonensis e nenhuma diferença estatística foi observada entre os grupos vacinados. Pode-se concluir que vacinas compostas por cepas isoladas de Leishmania protegem camundongos C57BL/10 contra, pelo menos, da infecção por L. (L.) amazonensis.

Wilson Mayrink; Gilmara Cristina dos Santos; Vicente de Paulo Coelho Peixoto de Toledo; Tânia Mara Pinto Dabés Guimarães; George Luis Lins Machado-Coelho; Odair Genaro; Carlos Alberto da Costa

2002-01-01

138

Leishmania mexicana in Proechimys iheringi denigratus Moojen (Rodentia, Echimyidae) in a region endemic for American cutaneous leishmaniasis  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Três isolados de Leishmania foram obtidos de cinco entre 27 exemplares do roedor Proechimys iheringi denigratus, capturados na região de Três Braços, na mata atlântica do Estado da Bahia, Brasil. O isolamento desse parasito foi feito através de inoculação de triturado de pele, baço e fígado em patas de hamsters. Em pelo menos um dos casos, (MTB-574), o parasito foi isolado da pele. Metas- tase foi observada nos hamsters inoculados, os parasitos cresceram abundan (more) temente em meios artificiais de cultura e um padrão suprapapilario típico foi obtido em Lutzomyia longipalpis, indicando que o parasito pertence ao complexo L. mexicana. Todos os isolados reagiram positivamente com anticorpos monoclonais de L. m. mexicana e L. m. amazonensis. A análise isoenzimática diferenciou o parasito de isolados padrões de L. m. mexicana. L. m. amazonensis. L. m. aristedesi. L. m. pifanoi. L. m. garnhami e L. m. ssp(Goiás-W. Barbosa). O parasito parece ser uma subespécie de L. mexicana muito próxima à L. m. amazonensis, da qual difere pela menor mobilidade eletroforêtica de GPI, PEP e ALAT. Este e o primeiro registro do isolamento de um parasito do gênero Leishmania em um roedor capturado no Estado da Bahia. Abstract in english Three isolates of Leishmania were recovered from five of 27 specimens of the rodent Proechimys iheringi denigratus Moojen captured near Três Braços in the Atlantic Forest region of Bahia, Brazil. Two of these isolates were recovered from hamsters inoculated with a pooled triturate of liver, spleen and skin tissue from apparently healthy P. i. denigratus. The third isolate was recovered from a triturate of only skin tissue from another. Metastasis was observed in the ino (more) culated hamsters, the parasites grew abundantly in artificial media and a typical suprapylarial pattern of infection in Lutzomyia longipalpis was produced indicating that the parasites belong to the Leishmania mexicana complex. All isolates reacted with Leishmania mexicana mexicana and Leishmania mexicana amazonensis monoclonal antibodies. The isoenzyme analysis differentiated these isolates from standard isolates of L. m. mexicana, L. m. amazonensis, L. m. aristedesi, L. m. pifanoi, L. m. garnhami and L. m. ssp.(Goiás-W. Barbosa). These isolates seem to be a subspecies of L. mexicana very closely related to L. m. amazonensis from which they differ by decreased electrophoretic mobility of GPI, PEP and ALAT. This is the first record of the isolation of a parasite of thegenus Leishmania in a rodent captured in the State of Bahia.

Barretto, Air C.; Peterson, Norman E.; Lago, Ednaldo; Rosa, Ana C.; Braga, Rosely S.M.; Cuba, Cesar A.C.; Vexenat, Julio A.; Marsden, Philip D.

1985-12-01

139

Assessment of immunity induced in mice by glycoproteins derived from different strains and species of Leishmania  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english A comparative study was undertaken on the immunogenic properties of 63kDa glycoproteins obtained from five different strains/species of Leishmania and assessed in C57BL/10 mice. The humoral immune response was assessed by ELISA against the five different antigens of the immunized animals. The cellular immune response was derived from Leishmania. The response was found to be species-specific in all of determined by means of the cytokine profiles secreted by the spleen cell (more) s of immunized animals. The presence of ³-IFN and IL-2, and the absence of IL-4 in the supernatants of cells stimulated by L. amazonensis antigen established that the cellular response is of Th1 type. The five glycoproteins tested were equally effective in protecting C57BL/10 mice against challenge by L. amazonensis. About 50% of the immunized animals were protected for six months.

Guimarães, Tânia Mara Pinto Dabés; Toledo, Vicente de Paulo Coelho Peixoto de; Costa, Carlos Alberto da; Costa, Roberto Teodoro da; Genaro, Odair; Williams, Paul; Mayrink, Wilson

1996-02-01

140

Cohabitation of Leishmania amazonensis and Coxiella burnetii.  

UK PubMed Central (United Kingdom)

Intracellular pathogens customize the composition and function of the vacuoles they occupy, and can arrest or distort vacuolar maturation. In doubly infected cells, vacuoles that contain two different parasites can be used to test for exclusionary mechanisms, for expression of vacuolar phenotypes that permit or restrict fusion, and for the survival of pathogens targeted to an unusual cellular compartment.

Rabinovitch M; Veras PS

1996-04-01

 
 
 
 
141

Kinetics of growth of Leishmania (Leishmania) chagasi cycle in McCoy cell culture Cinéticas de crescimento do ciclo da Leishmania (Leishmania) chagasi em cultura de células McCoy  

Directory of Open Access Journals (Sweden)

Full Text Available The kinetics of growth of Leishmania performed in vitro after internalization of the promastigote form in the cell and the occurrence of the transformation of the parasite into the amastigote form have been described by several authors. They used explants of macrophages in hamster spleen cell culture or in a human macrophage lineage cell, the U937. Using microscopy, the description of morphologic inter-relationship and the analysis of the production of specific molecules, it has been possible to define some of the peculiarities of the biology of the parasite. The present study shows the growth cycle of Leishmania chagasi during the observation of kinetic analysis undertaken with a McCoy cell lineage that lasted for a period of 144 hours. During the process, the morphologic transformation was revealed by indirect immunofluorescence (IF) and the molecules liberated in the extra cellular medium were observed by SDS-PAGE at 24-hour intervals during the whole 144-hour period. It was observed that in the first 72 hours the promastigote form of L. chagasi adhered to the cell membranes and assumed a rounded (amastigote-like) form. At 96 hours the infected cells showed morphologic alterations; at 120 hours the cells had liberated soluble fluorescent antigens into the extra cellular medium. At 144 hours, new elongated forms of the parasites, similar to promastigotes, were observed. In the SDS-PAGE, specific molecular weight proteins were observed at each point of the kinetic analysis showing that the McCoy cell imitates the macrophage and may be considered a useful model for the study of the infection of the Leishmania/cell binomial.Cinéticas de crescimento de Leishmania realizadas in vitro após a internalização da forma promastigota na célula e a ocorrência da transformação do parasito na forma amastigota foram descritas por vários autores, seja com a utilização de explantes de macrófagos em células de baço de hamster ou atualmente da célula de linhagem de macrófago humano U937. Aliando a microscopia à descrição das inter-relações morfológicas e à síntese de moléculas específicas foi possível esclarecer pontos sobre a biologia do parasito. O presente estudo mostra o acompanhamento do ciclo de crescimento da Leishmania chagasi em uma cinética realizada com células de linhagem McCoy, no período de 144 horas. Durante o processo, as transformações morfológicas foram reveladas pela reação de imunofluorescência indireta (RIFI) e as moléculas liberadas no meio extracelular foram observadas pelo método de SDS-PAGE, em intervalos de 24 horas no período de 144 horas. Observou-se que nas primeiras 72 horas, a forma promastigota da L. chagasi fica aderida à membrana das células com aspecto arredondado (amastigota-like). Em 96 horas as células infectadas apresentaram alterações morfológicas; em 120 horas, as células liberaram, para o meio extracelular, antígenos fluorescentes solúveis; e em 144 horas foram observadas novas formas alongadas dos parasitos como se fossem promastigotas. No SDS-PAGE, proteínas com pesos moleculares específicos são observadas em cada ponto da cinética, mostrando que a célula McCoy parece mimetizar o macrófago e que pode ser um modelo útil para o estudo da infecção do binômio leishmânia/célula.

Yeda L. Nogueira; Paulo M. Nakamura; Eunice A. B. Galati

2006-01-01

142

Kinetics of growth of Leishmania (Leishmania) chagasi cycle in McCoy cell culture/ Cinéticas de crescimento do ciclo da Leishmania (Leishmania) chagasi em cultura de células McCoy  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Cinéticas de crescimento de Leishmania realizadas in vitro após a internalização da forma promastigota na célula e a ocorrência da transformação do parasito na forma amastigota foram descritas por vários autores, seja com a utilização de explantes de macrófagos em células de baço de hamster ou atualmente da célula de linhagem de macrófago humano U937. Aliando a microscopia à descrição das inter-relações morfológicas e à síntese de moléculas espec? (more) ?ficas foi possível esclarecer pontos sobre a biologia do parasito. O presente estudo mostra o acompanhamento do ciclo de crescimento da Leishmania chagasi em uma cinética realizada com células de linhagem McCoy, no período de 144 horas. Durante o processo, as transformações morfológicas foram reveladas pela reação de imunofluorescência indireta (RIFI) e as moléculas liberadas no meio extracelular foram observadas pelo método de SDS-PAGE, em intervalos de 24 horas no período de 144 horas. Observou-se que nas primeiras 72 horas, a forma promastigota da L. chagasi fica aderida à membrana das células com aspecto arredondado (amastigota-like). Em 96 horas as células infectadas apresentaram alterações morfológicas; em 120 horas, as células liberaram, para o meio extracelular, antígenos fluorescentes solúveis; e em 144 horas foram observadas novas formas alongadas dos parasitos como se fossem promastigotas. No SDS-PAGE, proteínas com pesos moleculares específicos são observadas em cada ponto da cinética, mostrando que a célula McCoy parece mimetizar o macrófago e que pode ser um modelo útil para o estudo da infecção do binômio leishmânia/célula. Abstract in english The kinetics of growth of Leishmania performed in vitro after internalization of the promastigote form in the cell and the occurrence of the transformation of the parasite into the amastigote form have been described by several authors. They used explants of macrophages in hamster spleen cell culture or in a human macrophage lineage cell, the U937. Using microscopy, the description of morphologic inter-relationship and the analysis of the production of specific molecules, (more) it has been possible to define some of the peculiarities of the biology of the parasite. The present study shows the growth cycle of Leishmania chagasi during the observation of kinetic analysis undertaken with a McCoy cell lineage that lasted for a period of 144 hours. During the process, the morphologic transformation was revealed by indirect immunofluorescence (IF) and the molecules liberated in the extra cellular medium were observed by SDS-PAGE at 24-hour intervals during the whole 144-hour period. It was observed that in the first 72 hours the promastigote form of L. chagasi adhered to the cell membranes and assumed a rounded (amastigote-like) form. At 96 hours the infected cells showed morphologic alterations; at 120 hours the cells had liberated soluble fluorescent antigens into the extra cellular medium. At 144 hours, new elongated forms of the parasites, similar to promastigotes, were observed. In the SDS-PAGE, specific molecular weight proteins were observed at each point of the kinetic analysis showing that the McCoy cell imitates the macrophage and may be considered a useful model for the study of the infection of the Leishmania/cell binomial.

Nogueira, Yeda L.; Nakamura, Paulo M.; Galati, Eunice A. B.

2006-12-01

143

Constitutive mosaic aneuploidy: a unique genetic feature widespread in the Leishmania genus.  

UK PubMed Central (United Kingdom)

Using fluorescence in situ hybridization, we determined the ploidy of four species of Leishmania: Leishmania infantum, Leishmania donovani, Leishmania tropica and Leishmania amazonensis. We found that each cell in a strain possesses a combination of mono-, di- and trisomies for all chromosomes; ploidy patterns were different among all strains/species. These results extend those we previously described in Leishmania major, demonstrating that mosaic aneuploidy is a genetic feature widespread to the Leishmania genus. In addition to the genetic consequences induced by this mosaicism, the apparent absence of alternation between haploid/diploid stages questions the modality of genetic exchange in Leishmania sp.

Lachaud L; Bourgeois N; Kuk N; Morelle C; Crobu L; Merlin G; Bastien P; Pagès M; Sterkers Y

2013-10-01

144

PCR-RFLP/Hsp70 para identificar y tipificar Leishmania de la región neotropical PCR-RFLP/Hsp70 for identification and tipification of Leishmania from the tropical region  

Directory of Open Access Journals (Sweden)

Full Text Available Se realizó la estandarización de las condiciones de amplificación del gen que codifica para la proteína de choque térmico de 70 kDa (Hsp70) de Leishmania mediante la reacción en cadena de la polimerasa (PCR-Hsp70), así como el análisis posterior de la longitud de los fragmentos de restricción (RFLP) del producto amplificado, utilizando como molde ADN puro de una cepa de referencia de Leishmania mexicana. Se estudió la sensibilidad y especificidad analíticas de la PCR, así como la reproducibilidad, utilizando ADN de L. mexicana, L. amazonensis, L. guyanensis y L. lainsoni. Se obtuvo una banda de 1,3 Kpb, demostrándose la amplificación del gen que codifica para la Hsp70. Los patrones de bandas obtenidos tras la digestión enzimática, utilizando la enzima Hae III, permitieron establecer diferencias entre las especies estudiadas: L. guyanensis y L. lainsoni se diferencian entre sí y estas a su vez de L. mexicana y L. amazonensis, que mostraron un patrón de bandas común. La sensibilidad y especificidad analíticas de la técnica fueron adecuadas. Se demostró la factibilidad de identificar y tipificar especies del continente americano mediante la PCR-RFLP/Hsp70, y de utilizar la restricción enzimática del producto amplificado para distinguir entre Leishmania spp. y Trypanosoma cruzi, dándose un primer paso en el establecimiento de estos métodos moleculares en el laboratorio de referencia del instituto.The optimization of the PCR conditions for amplification of the gene coding for the 70kDa (HSp70) heat shock protein as well as the analysis of the restriction fragment length polymorphism (RFLP) were carried out. DNA from a reference strain of Leishmania mexicana was used as template. Analytical sensitivity and specificity, and reproducibility of PCR using DNA from L. mexicana, L.amazonensis, L. guyanensis and L. lainsoni were determined. A 1.3 kp band was obtained, which confirmed gene amplification. The band patterns derived from Haelll enzyme digestion allowed differentiating several species. L. guyanensis and L. lainsoni were different from each other, while L. mexicana and L. amazonensis, which shared a common pattern, were different from the other two species. Analytical sensitivity and specificity were adequate. The enzymatic restriction of the PCR product made it possible to differentiate Leishmania spp. from T. cruzi. The feasibility of identifying and typifying species from the American continent through PCR-RFLP/Hsp70 and of using enzymatic restriction of amplified product to distinguish Leishmania spp. from Trypanosoma cruzi was shown. This was the first step in implementing these molecular methods in the reference laboratory of the Institute.

Ana Margarita Montalvo; Jorge Fraga; Jaqueline Aylema Romero; Lianet Monzote; Ivon Montano; Jean Claude Dujardin

2006-01-01

145

PCR-RFLP/Hsp70 para identificar y tipificar Leishmania de la región neotropical/ PCR-RFLP/Hsp70 for identification and tipification of Leishmania from the tropical region  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Se realizó la estandarización de las condiciones de amplificación del gen que codifica para la proteína de choque térmico de 70 kDa (Hsp70) de Leishmania mediante la reacción en cadena de la polimerasa (PCR-Hsp70), así como el análisis posterior de la longitud de los fragmentos de restricción (RFLP) del producto amplificado, utilizando como molde ADN puro de una cepa de referencia de Leishmania mexicana. Se estudió la sensibilidad y especificidad analíticas de (more) la PCR, así como la reproducibilidad, utilizando ADN de L. mexicana, L. amazonensis, L. guyanensis y L. lainsoni. Se obtuvo una banda de 1,3 Kpb, demostrándose la amplificación del gen que codifica para la Hsp70. Los patrones de bandas obtenidos tras la digestión enzimática, utilizando la enzima Hae III, permitieron establecer diferencias entre las especies estudiadas: L. guyanensis y L. lainsoni se diferencian entre sí y estas a su vez de L. mexicana y L. amazonensis, que mostraron un patrón de bandas común. La sensibilidad y especificidad analíticas de la técnica fueron adecuadas. Se demostró la factibilidad de identificar y tipificar especies del continente americano mediante la PCR-RFLP/Hsp70, y de utilizar la restricción enzimática del producto amplificado para distinguir entre Leishmania spp. y Trypanosoma cruzi, dándose un primer paso en el establecimiento de estos métodos moleculares en el laboratorio de referencia del instituto. Abstract in english The optimization of the PCR conditions for amplification of the gene coding for the 70kDa (HSp70) heat shock protein as well as the analysis of the restriction fragment length polymorphism (RFLP) were carried out. DNA from a reference strain of Leishmania mexicana was used as template. Analytical sensitivity and specificity, and reproducibility of PCR using DNA from L. mexicana, L.amazonensis, L. guyanensis and L. lainsoni were determined. A 1.3 kp band was obtained, whic (more) h confirmed gene amplification. The band patterns derived from Haelll enzyme digestion allowed differentiating several species. L. guyanensis and L. lainsoni were different from each other, while L. mexicana and L. amazonensis, which shared a common pattern, were different from the other two species. Analytical sensitivity and specificity were adequate. The enzymatic restriction of the PCR product made it possible to differentiate Leishmania spp. from T. cruzi. The feasibility of identifying and typifying species from the American continent through PCR-RFLP/Hsp70 and of using enzymatic restriction of amplified product to distinguish Leishmania spp. from Trypanosoma cruzi was shown. This was the first step in implementing these molecular methods in the reference laboratory of the Institute.

Montalvo, Ana Margarita; Fraga, Jorge; Aylema Romero, Jaqueline; Monzote, Lianet; Montano, Ivon; Dujardin, Jean Claude

2006-12-01

146

Effects of seco-steroids purified from Physalis angulata L., Solanaceae, on the viability of Leishmania sp Efeitos de seco-esteróides purificados de Physalis angulata L., Solanaceae na viabilidade de Leishmania sp  

Directory of Open Access Journals (Sweden)

Full Text Available Physalis angulata L., Solanaceae, is an annual herb commonly used in popular medicine in many tropical and subtropical countries. P. angulata extracts contain a variety of substances, but little is known about their pharmacological activities. In this work we investigated the in vitro antileishmanial activity of seco-steroids (physalins) purified from P. angulata. Addition of physalins B, F, and G caused a concentration-dependent inhibition in the growth of L. amazonensis promastigotes, being the IC50 values were 6.8, 1.4, and 9.2 ?M, respectively. Physalin D was less active and had an IC50 value of 30.5 ?M. Physalins were also active in cultures of other Leishmania species (L. major, L. braziliensis, and L. chagasi). Our results demonstrate the potent antileishmanial activity of physalins in cultures of Leishmania species of the New and Old Worlds and suggest the therapeutic potential of these seco-steroids in leishmaniasis.Physalis angulata L., Solanaceae, é uma erva anual utilizada na medicina popular em muitos países tropicais e subtropicais. Apesar dos extratos da P. angulata apresentarem uma grande variedade de substâncias, pouco é conhecido sobre a sua atividade farmacológica. Neste trabalho foi investigado a atividade antileishmania in vitro de seco-esteroides (fisalinas) purificados da P. angulata. O tratamento com as fisalinas B, F e G causou uma inibição concentração-dependente do crescimento de promastigotas de Leishmania amazonensis em cultura axênica, com valores de IC50 de 6,8, 1,4, e 9,2 ?M respectivamente. A fisalina D foi menos ativa, com valores de IC50 de 30,5 ?M. Foi também observada uma atividade leishmanicida em culturas de outras espécies de Leishmania (L. major, L. braziliensis e L. chagasi). Nossos resultados demonstram que as fisalinas inibem o crescimento dos promastigotas com o tratamento de espécies de Leishmania do Velho e do Novo Mundos e sugerem o potencial terapêutico destas moléculas na leishmaniose.

Elisalva T. Guimarães; Milena S. Lima; Luana A. Santos; Ivone M. Ribeiro; Therezinha B. C. Tomassini; Ricardo Ribeiro dos Santos; Washington L. C. dos Santos; Milena B. P. Soares

2010-01-01

147

Vaccination of C57BL/10 mice against cutaneous leishmaniasis using killed promastigotes of different strains and species of Leishmania  

Directory of Open Access Journals (Sweden)

Full Text Available Antigenic extracts from five Leishmania stocks were used to vaccinate C57BL/10 mice. The Leishvacin® and PH8 monovalent vaccine yielded the highest IFN-gamma levels in the supernatants of spleen cell culture from vaccinated animals. Each single strain immunized group showed evidence of protective immunity six months after the challenge with promastigotes of Leishmania (Leishmania) amazonensis. No differences were detected between the vaccinated groups. It can be concluded that vaccines composed of single Leishmania stocks can provide protection to C57BL/10 mice against L. (L.) amazonensis infection.

Mayrink Wilson; Santos Gilmara Cristina dos; Toledo Vicente de Paulo Coelho Peixoto de; Guimarães Tânia Mara Pinto Dabés; Machado-Coelho George Luis Lins; Genaro Odair; Costa Carlos Alberto da

2002-01-01

148

Cura espontânea da leishmaniose causada por Leishmania Viannia Braziliensis em lesões cutâneas  

Directory of Open Access Journals (Sweden)

Full Text Available Os autores relatam que durante 14 anos de trabalho clínico em campo, realizado nas comunidades de Três Braços e Corte de Pedra, Bahia, acompanharam 1.416 pacientes portadores de Leishmaniose Tegumentar Americana, cuja espécie envolvida na transmissão, é predominantemente a Leishmania Viannia brasilienses. A terapêutica utilizada rotineiramente nos casos é o antimoniato-N-metilglucamina (Glucantime). Contudo, 16 pacientes do sexo masculino recusaram-se a utilizar a medicação e 6 do sexo feminino encontravam-se em período gestacional, portanto não utilizaram o medicamento. Estes pacientes foram acompanhados por um período entre 4 a 12 anos, a partir do diagnóstico. Observou-se que em 9 pacientes (40,9%) desta casuística, o tempo de cicatrizaçâo após o aparecimento da lesão, pode ser calculado em 6 meses de evolução. Quando se eleva a observação para 12 meses, temos que 19 pacientes (86,3%) cicatrizaram suas lesões neste período. Em 3 casos (13,6%) as lesões permaneceram ativas por mais de 12 meses. Conclui-se que os determinantes da cicatrizaçâo natural das lesões produzidas por Leishmania Viannia Braziliensis permanecem desconhecidos, dificultando para nós entendermos e compararmos aos efeitos das drogas utilizadas no tratamento da leishmaniose tegumentar.In field clinics in the comunities of Três Braços and Corte de Pedra, Bahia, we have attended 1.416 patients with tegumentary leishmaniasis in fourteen years, the predomi nant species in transmission is Leishmania Viannia brasiliensis (LVB). Because of the danger of metastasis with this infection treatment was routinely recomended with Glucantime. However sixteen patients refused injection therapy and six women were pregnant when seen and not treated. All patients were followed up in our clinic. All these patients closed their skin ulcers although one subsequently relapsed. Patients were followed up for variable periods (four to twelve years), after the diagnosis. In nine patients (40,9%) of the cohort, the time to healing after initiation of the lesion was calculated as six months of evolution. At twelve months, nineteen patients (86,3%) had complete healing of their lesions. In three patients an active lesion was present for longer than one year. The determinants of this variable natural evolution of human LVB lesion remains completely unknown. It is difficult for us to understand and compare the effects of therapeutic agents in mucocutaneous leishmaniasis.

Jackson Maurício Lopes Costa; Kyola Costa Vale; Flávio França; Ana Cristina R. Saldanha; Joilda Oliveira da Silva; Ednaldo L. Lago; Philip D. Marsden; Albino V. Magalhães; Conceição de Maria P. e Silva; Artur Serra Neto; Clóvis Eduardo S. Galvão

1990-01-01

149

Cura espontânea da leishmaniose causada por Leishmania Viannia Braziliensis em lesões cutâneas  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Os autores relatam que durante 14 anos de trabalho clínico em campo, realizado nas comunidades de Três Braços e Corte de Pedra, Bahia, acompanharam 1.416 pacientes portadores de Leishmaniose Tegumentar Americana, cuja espécie envolvida na transmissão, é predominantemente a Leishmania Viannia brasilienses. A terapêutica utilizada rotineiramente nos casos é o antimoniato-N-metilglucamina (Glucantime). Contudo, 16 pacientes do sexo masculino recusaram-se a utilizar a (more) medicação e 6 do sexo feminino encontravam-se em período gestacional, portanto não utilizaram o medicamento. Estes pacientes foram acompanhados por um período entre 4 a 12 anos, a partir do diagnóstico. Observou-se que em 9 pacientes (40,9%) desta casuística, o tempo de cicatrizaçâo após o aparecimento da lesão, pode ser calculado em 6 meses de evolução. Quando se eleva a observação para 12 meses, temos que 19 pacientes (86,3%) cicatrizaram suas lesões neste período. Em 3 casos (13,6%) as lesões permaneceram ativas por mais de 12 meses. Conclui-se que os determinantes da cicatrizaçâo natural das lesões produzidas por Leishmania Viannia Braziliensis permanecem desconhecidos, dificultando para nós entendermos e compararmos aos efeitos das drogas utilizadas no tratamento da leishmaniose tegumentar. Abstract in english In field clinics in the comunities of Três Braços and Corte de Pedra, Bahia, we have attended 1.416 patients with tegumentary leishmaniasis in fourteen years, the predomi nant species in transmission is Leishmania Viannia brasiliensis (LVB). Because of the danger of metastasis with this infection treatment was routinely recomended with Glucantime. However sixteen patients refused injection therapy and six women were pregnant when seen and not treated. All patients were (more) followed up in our clinic. All these patients closed their skin ulcers although one subsequently relapsed. Patients were followed up for variable periods (four to twelve years), after the diagnosis. In nine patients (40,9%) of the cohort, the time to healing after initiation of the lesion was calculated as six months of evolution. At twelve months, nineteen patients (86,3%) had complete healing of their lesions. In three patients an active lesion was present for longer than one year. The determinants of this variable natural evolution of human LVB lesion remains completely unknown. It is difficult for us to understand and compare the effects of therapeutic agents in mucocutaneous leishmaniasis.

Costa, Jackson Maurício Lopes; Vale, Kyola Costa; França, Flávio; Saldanha, Ana Cristina R.; Silva, Joilda Oliveira da; Lago, Ednaldo L.; Marsden, Philip D.; Magalhães, Albino V.; Silva, Conceição de Maria P. e; Serra Neto, Artur; Galvão, Clóvis Eduardo S.

1990-12-01

150

Análise histomorfométrica da matriz extracelular do linfonodo poplíteo de cães naturalmente infectados por Leishmania (L.) chagasi  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Nas Américas, a leishmaniose visceral canina é causada por Leishmania (Leishmania) chagasi, um protozoário intracelular obrigatório do sistema fagocítico mononuclear; as principais alterações histológicas associadas a essa doença ocorrem nos em órgãos linfóides. Apesar de o cão ser considerado o principal mantenedor e disseminador da leishmaniose no ambiente urbano, são escassos estudos dos aspectos histopatológicos e histomorfométricos, em cães naturalme (more) nte infectados com L. chagasi, que investiguem a interação entre o parasito e a matriz extracelular. Este estudo visou caracterizar e quantificar as alterações dos componentes celulares e da matriz extracelular (colágenos I e III) do linfonodo poplíteo de 22 cães com infecção natural por L. chagasi detectada através da reação de imunofluorescência indireta (RIF) e compará-las com as alterações encontradas no linfonodo poplíteo de 10 cães não-infectados, negativos na RIF e clinicamente saudáveis. Fragmentos dos linfonodos foram seccionados longitudinalmente, processados rotineiramente para exame histológico e corados por hematoxilina-eosina. Cortes adicionais do mesmo linfonodo incluídos em glicol metacrilato foram corados pelo azul de toluidina para histomorfometria. Linfonodos de cães infectados apresentaram linfadenopatia generalizada, aumento do tamanho e do número dos folículos linfóides, hipertrofia da cápsula e hiperplasia linfóide significativa. Nos linfonodos de cães do grupo infectado, a análise quantitativa de fibras colágenas mostrou significativo predomínio do colágeno I sobre o colágeno III. Esses resultados demonstram que cães infectados por L. chagasi apresentam degradação dos constituintes da matriz extracelular e conseqüente destruição do arcabouço linfóide, alterando a morfologia do órgão. Abstract in english In the Americas, canine visceral leishmaniasis is caused by Leishmania (Leishmania) chagasi, an obligatory intracellular parasite of the phagocytic-monocytic system; the main histological changes associated with this disease occur in the lymphoid organs. Although dogs are considered to be the main carriers and disseminators of leishmaniasis in urban areas, there are few studies on the histopathologic and histomorphometric aspects in dogs naturally infected by L.chagasi an (more) alyzing the interaction between parasite and extracellular matrix. The current study characterize and quantify changes in the cellular and extracellular matrix (collagens type I and III) components of the popliteal lymph node from of 22 dogs with the natural infection by L. chagasi confirmed by indirect immuno-fluorescence assay (IFA) and compare theses findings with those fund in the popliteal lymph node from 10 non-infected dogs, that reacted negative in the IFA, and were clinically healthy. Lymph node fragments were longitudinally sliced and sections were processed for routine histopathology and stained by hematoxylin and eosin. For histomorphometry, additional sections from the same lymph node were fixed in glycol methacrylate and stained with toluidine blue. Lymph nodes from affected dogs were systemically enlarged, had increased numbers of lymphoid follicles, capsule hyperplasia and hypertrophy, and significant hyperplasia of lymphoid cells. In the lymph nodes from infected dogs, quantitative analyses of collagen fibers revealed predominance of type I collagen over type III fibers. These results demonstrate that dogs infected by L.chagasi experience degradation of the extracellular matrix components and consequently destruction of the lymphoid framework, thus altering nodal morphology.

Kondo, Kris Régia J.; Fonseca, Cláudio César; Matta, Sérgio Luis P. da; Viloria, Marlene Isabel V.

2009-08-01

151

Diagnóstico molecular da taxa de infecção natural de flebotomíneos (Psychodidae, Lutzomyia) por Leishmania sp na Amazônia maranhense/ Molecular diagnosis of the natural infection rate due to Leishmania sp in sandflies (Psychodidae, Lutzomyia) in the Amazon region of Maranhão, Brazil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A taxa de infecção natural de três diferentes espécies de flebotomíneos por Leishmania foi estudada usando a técnica de reação em cadeia da polimerase. Primers específicos para Leishmania foram designados para examinar se os pools de flebotomíneos estavam infectadas. Um total de 1.100 fêmeas separadas em pools de 10 indivíduos foram examinados, consistindo de 50 Lutzomyia whitmani, 43 Lutzomyia triacantha e 17 Lutzomyia choti. De todos os pools analisados, 4 d (more) e Lutzomyia whitmani estavam positivos, mas nenhum pool das duas espécies restantes estava infectado. Deste modo, uma taxa de infecção de 0,4% foi verificada neste estudo. Esta taxa de infecção associada a estudos anteriores sugere que Lutzomyia whitmani transmite Leishmania aos mamíferos em Buriticupu, Maranhão. Abstract in english The natural infection rate due to Leishmania was studied in three different sandfly species using the polymerase chain reaction technique. Leishmania specific primers were designed to examine whether sandfly pools were infected. In total 1,100 female sandflies separated into pools of 10 individuals, consisting of 50 pools of Lutzomyia whitmani, 43 of Lutzomyia triacantha and 17 of Lutzomyia choti, were analyzed. Among all the pools examined, four pools of Lutzomyia whitma (more) ni were positive, but none of the pools of the other two species were infected. Thus, a total infection rate of 0.4% was established in this study. A similar infection rate was found in previous studies, suggesting that Lutzomyia whitmani transmits Leishmania to mammals in Buriticupu, Maranhão.

Oliveira-Pereira, Yrla Nívea; Rebêlo, José Manuel Macário; Moraes, Jorge Luiz Pinto; Pereira, Silma Regina Ferreira

2006-12-01

152

Diagnóstico molecular da taxa de infecção natural de flebotomíneos (Psychodidae, Lutzomyia) por Leishmania sp na Amazônia maranhense Molecular diagnosis of the natural infection rate due to Leishmania sp in sandflies (Psychodidae, Lutzomyia) in the Amazon region of Maranhão, Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available A taxa de infecção natural de três diferentes espécies de flebotomíneos por Leishmania foi estudada usando a técnica de reação em cadeia da polimerase. Primers específicos para Leishmania foram designados para examinar se os pools de flebotomíneos estavam infectadas. Um total de 1.100 fêmeas separadas em pools de 10 indivíduos foram examinados, consistindo de 50 Lutzomyia whitmani, 43 Lutzomyia triacantha e 17 Lutzomyia choti. De todos os pools analisados, 4 de Lutzomyia whitmani estavam positivos, mas nenhum pool das duas espécies restantes estava infectado. Deste modo, uma taxa de infecção de 0,4% foi verificada neste estudo. Esta taxa de infecção associada a estudos anteriores sugere que Lutzomyia whitmani transmite Leishmania aos mamíferos em Buriticupu, Maranhão.The natural infection rate due to Leishmania was studied in three different sandfly species using the polymerase chain reaction technique. Leishmania specific primers were designed to examine whether sandfly pools were infected. In total 1,100 female sandflies separated into pools of 10 individuals, consisting of 50 pools of Lutzomyia whitmani, 43 of Lutzomyia triacantha and 17 of Lutzomyia choti, were analyzed. Among all the pools examined, four pools of Lutzomyia whitmani were positive, but none of the pools of the other two species were infected. Thus, a total infection rate of 0.4% was established in this study. A similar infection rate was found in previous studies, suggesting that Lutzomyia whitmani transmits Leishmania to mammals in Buriticupu, Maranhão.

Yrla Nívea Oliveira-Pereira; José Manuel Macário Rebêlo; Jorge Luiz Pinto Moraes; Silma Regina Ferreira Pereira

2006-01-01

153

Histopatologia da leishmaniose tegumentar por Leishmania braziliensis braziliensis. 2. Resposta humoral tissular/ Histopathology of mucocutaneous leishmaniasis caused by Leishmania brasiliensis brasiliensis. 2. Tissue humoral response  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Os A.A. analisaram a resposta humoral nas lesões de 90 pacientes de Leishmaniose Tegumentar ? causada por Leishmania braziliensis brasiliensis ?, utilizando o método da imunoperoxidase para identificar nos tecidos a presença de IgA, IgG, IgM, fração C3 do complemento e fibrina. Constataram a presença de IgA, IgC e IgM nos plasmócitos tissulares, com predomínio de IgG. Admitiram aue a passagem dessas imunoglobulinas para os tecidos possibilitando a opsonização (more) do parasites e/ou de seus antígenos, permitiria a ocorrência de fenômenos necróticos que representam um dos mecanismos eficazes de redução da carga parasitária. Efetivamente, nas áreas de necrose e nas paredes dos vasos inflamados identificaram depósito de imunoglobulinas, fração C3 do complemento e fibrina ? elementos do hospedeiro que fazem parte dos imunocomplexos. Interpretaram essa necrose tissular como o resultado da ação de imunocomplexos na região de equivalência ou com discreto excesso de antígenos ítipos ABTHTJS). A presença de antígenos parasitários, expressos nas membranas dos macrófagos quando em contato com imunoglobulinas tissulares, na fase inicial da lesão, possibilitaria a instalação de uma reação antígeno-anticorpo, a qual explicaria o aparecimento da necrose na Leishmaniose Tegumentar. Abstract in english The Authors analysed the humoral response in biopsy material from 90 patients with Mucocutaneous Leishmaniasis caused by Leishmania braziliensis braziliensis, utilising the immunoperoxidase method to identify IgA, IgG, IgM, C3 complement fraction and fibrin in the tissue. The presence of IgG, IgA and IgM was found in tissue plasma cells with a predominance of IgG and this was correlated significantly with the number of plasma cells in the lesion. The presence of immunoglo (more) bulins in the tissues stimulated the opsonisation of parasites and/or their antigens resulting in necrosis which represents one of the effective mechanisms to reduce parasite load. In ne- crotic areas and the walls of inflammed vessels immunoglobulins were deposited as well as the C3 fraction of complement and fibrin ? immunocomplex fractions derived from the host. This tissue necrosis was interpreted as the result of the action of immunocomplexes in a region with equivalent or a smally excess of antigen (Arthus type reaction). The presence of parasite antigens expressed on the macrophage membrane in the initial phase of the lesion when in contact with tissue immunoglobulins, leads to the installation of an antigen-antibody reaction resulting in the appearance of necrosisin Mucocutaneous Leishmaniasis.

Magalhães, Albino Verçosa de; Moraes, Mário A. P.; Raick, Alberto N.; Llanos-Cuentas, Alejandro; Costa, Jackson M. L.; Cuba, César C.; Marsden, Philip D.

1986-10-01

154

Estado atual da leishmaniose cutânea difusa (LCD) no Estado do Maranhão: II. aspectos epidemiológicos, clínico-evolutivos  

Directory of Open Access Journals (Sweden)

Full Text Available Os Autores fazem um estudo retrospectivo e prospectivo de 6 pacientes portadores de leishmaniose cutânea difusa, observados no Estado do Maranhão a partir de 1974. Os casos abordados são oriundos de diversas regiões do estado, observando-se em todos eles o envolvimento da leishmania (Leishmania) amazonensis, sendo que 5 (84%) dos pacientes apresentaram início de doença na 1ª década de vida. Em todos os pacientes envolvidos no estudo, houve relato de lesão inicial nodular única, que, posteriormente, em período variável de tempo, disseminou-se adquirindo outros aspectos. Evolutivamente apresentaram múltiplas lesões nodulares e ulceradas, intradermorreação de Montenegro(-) e refratariedade aos esquemas terapêuticos utilizados até ao presente momento.The authors describe a retrospective and prospective study of 6 patients with diffuse cutaneous leishmaniasis observed in the State of Maranhão, since 1974. The patients comefromdifferentruralregions of the state and in all of them Leishmania (Leishmania) amazonensis was the cause five of the patients initiated their disease in the first decade of life. All the patients first had a solitary, nodular lesion, that after a variable period of time, disseminated and acquired other aspects. Sequentially the patients presented multiple nodular and ulcerative lesions, negative leishmania skin-lests and a refractory response to the therapeutic schedules used up to the present.

Jackson Maurício Lopes Costa; Ana Cristina Rodrigues Saldanha; Ana Carla de Melo e Silva; Artur Serra Neto; Clovis Eduardo Santos Galvão; Conceição de Maria Pedroso e Silva; Antonio Rafael da Silva

1992-01-01

155

Gamma radiation affects the anti-Leishmania activity of Bothrops moojeni venom and correlates with L-amino acid oxidase activity  

International Nuclear Information System (INIS)

[en] Leishmania causes human disfiguring skin disease in endemic areas of Amazon and North Eastern Brazil. Those parasites present a remarkable resistance to most treatments, except those using toxic antimonial salts. We detected a specific anti-Leishmania activity in snake venoms, using an in vitro promastigote assay. In this report, we analyzed the activity of Bothrops moojeni venom against L. Amazonensis, using whole venom or fractions of L-amino acid oxidase (L-AO). Crude venom of B.moojeni, was fractionated by molecular exclusion chromatography. Activity against promastigotes was detected by respiratory oxidative conversion of MTT in a colorimetric assay and L-AO activity was detected by a colorimetric assay with peroxidase and OPD as revealing reagents. Crude venom was irradiated with 500, 1000, and 2000 Gy in a 60 Co gamma radiation source. The venom had an anti-Leishmania activity of 33 pg/promastigote and the active fraction migrates as 100-150 kDa, close to the size described for L-AOs, and also presented L-AO activity. The radiation reduces both the L-AO and anti-Leishmania activity in a dose dependent effect. Those data suggests the anti-Leishmania activity in this venom is closely related to the L-amino acid oxidase activity and also that radiation could be used as a tool to detect specific activities reduction in water solutions, similarly to observed in dry preparations. (author)

1999-09-03

156

Gamma radiation affects the anti-Leishmania activity of Bothrops moojeni venom and correlates with L-amino acid oxidase activity  

Energy Technology Data Exchange (ETDEWEB)

Leishmania causes human disfiguring skin disease in endemic areas of Amazon and North Eastern Brazil. Those parasites present a remarkable resistance to most treatments, except those using toxic antimonial salts. We detected a specific anti-Leishmania activity in snake venoms, using an in vitro promastigote assay. In this report, we analyzed the activity of Bothrops moojeni venom against L. Amazonensis, using whole venom or fractions of L-amino acid oxidase (L-AO). Crude venom of B.moojeni, was fractionated by molecular exclusion chromatography. Activity against promastigotes was detected by respiratory oxidative conversion of MTT in a colorimetric assay and L-AO activity was detected by a colorimetric assay with peroxidase and OPD as revealing reagents. Crude venom was irradiated with 500, 1000, and 2000 Gy in a {sup 60} Co gamma radiation source. The venom had an anti-Leishmania activity of 33 pg/promastigote and the active fraction migrates as 100-150 kDa, close to the size described for L-AOs, and also presented L-AO activity. The radiation reduces both the L-AO and anti-Leishmania activity in a dose dependent effect. Those data suggests the anti-Leishmania activity in this venom is closely related to the L-amino acid oxidase activity and also that radiation could be used as a tool to detect specific activities reduction in water solutions, similarly to observed in dry preparations. (author) 13 refs., 3 figs.

Tempone, A.G.; Lourenco, C.O.; Spencer, P.J.; Rogero, J.R.; Nascimento, N. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Div. de Radiobiologia; Andrade Junior, H.F. [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina. Inst. de Medicina Tropical

1999-11-01

157

Characterization of Leishmania infantum species in dogs from the urban area of Cuiabá, State of Mato Grosso, Brazil/ Caracterização da espécie Leishmania infantum em cães de área urbana de Cuiabá, Estado do Mato Grosso  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese INTRODUÇÃO: A leishmaniose visceral apresenta comportamento urbano em algumas cidades brasileiras, sendo os cães domésticos as principais fontes de infecção. Em Cuiabá-MT, a leishmaniose visceral canina foi diagnosticada e caracterizada, como recomendação do Ministério da Saúde. MÉTODOS: Amostras biológicas de cães suspeitos foram analisadas por eletroforese de isoenzimas. Foram utilizadas a enzima 6PGDH e a cepa de referência IOC/L0566 (MHOM/BR/1975/M2903) (more) de Leishmania (Leishmania) infantum, como um dos controles. RESULTADOS: A análise eletroforética revelou que os isolados pertenciam à espécie L. (L.) infantum. CONCLUSÕES: Os autores ressaltam a importância da caracterização da espécie, principalmente em cidades com infecção mista, como Cuiabá. Abstract in english INTRODUCTION: Visceral leishmaniasis presents urban behavior in some Brazilian cities, with domestic dogs as the main infection source. In Cuiabá, MT, canine visceral leishmaniasis was diagnosed and characterized as recommended by the Ministry of Health. METHODS: Biological samples from suspected canine carriers were analyzed by the isoenzyme electrophoresis technique. The 6PGDH enzyme and reference strain IOC/L0566 (MHOM/BR/1975/M2903) of Leishmania (Leishmania) infantu (more) m was used as one of the controls. RESULTS: Electrophoresis analysis revealed that the canine isolates belonged to the species L. (L.) infantum. CONCLUSIONS: The authors emphasize the importance of species characterization, particularly in areas of mixed infection like Cuiabá.

Santis, Bianca De; Santos, Elizabeth Gloria Oliveira Barbosa; Cupolillo, Elisa; Porrozzi, Renato; Cavalcanti, Amanda dos Santos; Santos, Bárbara Neves dos; Moura, Saulo Teixeira De; Malhado, Kellen; Chaves, Sergio Augusto Miranda

2011-12-01

158

Effect of HIV protease inhibitors on New World Leishmania.  

UK PubMed Central (United Kingdom)

The incidence of HIV/Leishmania co-infection decreases after antiretroviral drug therapy; therefore, the in vitro and in vivo activity of three antiretroviral drugs against Leishmania (Viannia) braziliensis and L. (L.) amazonensis was evaluated. Different concentrations of indinavir (IDV), atazanavir (ATV), and ritonavir (RTV) were added to promastigote cultures, and the 50% inhibitory concentration (IC50) was determined. IDV and RTV were also evaluated against intracellular amastigotes, and the Infection Index determined. BALB/c mice, infected with L. (L.) amazonensis in the left footpad, were treated orally with IDV and RTV for 30 days, and monitored by measuring the footpad thickness and parasite load of regional lymph nodes and spleen. For promastigotes, IDV exhibited an IC50 value of 100 ?M against L.(L.) amazonensis. The RTV IC50 for L. (L.) amazonensis and L. (V.) braziliensis were 40 and 2.3 ?M, respectively, and the ATV IC50 for L. (V.) braziliensis was 266 ?M. For intracellular amastigotes, IDV (25, 50, and 100 ?M) significantly decreased the Infection Index of L. (L.) amazonensis (56.8%, 47.9%, and 65.0%) and L. (V.) braziliensis (37.8%, 48.7%, and 43.2%). RTV (12.5, 25, and 50 ?M) decreased the infection index of L. (L.) amazonensis by 26.3%, 42.4%, and 44.0%, and that of L. (V.) braziliensis by 27.6%, 37.3%, and 39.2%. Antiretroviral-treated mice had a significant reduction in footpad thickness after the third week of IDV and after the fifth week of RTV treatment. However, there was no reduction in parasite load. These results suggest that IDV and RTV have anti-Leishmania activity, but only in higher concentrations.

Demarchi IG; Silveira TG; Ferreira IC; Lonardoni MV

2012-12-01

159

Histological evaluation of the lesion induced by inoculation of Leishmania mexicana in the cheek pouch of the hamster/ Avaliação histológica da lesão induzida pela inoculação de Leishmania mexicana na bolsa jugal do hamster  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese No presente estudo, investigamos o papel da resposta imune na morfologia do granuloma leishmaniótico induzido na bolsa jugal do hamster, um local imunologicamente privilegiado, após inoculação de 3x10(5) Leishmania mexicana. Os animais foram avaliados histológica e imunologicamente até os 120 dias da inoculação. Independente da época do sacrifício, os animais foram sempre não reatores ao teste do coxim plantar. Histologicamente, a inoculação de Leishmania mex (more) icana na bolsa jugal resultou na formação de abcesso que evoluiu para reação granulomatosa rica em formas amastigotas e, posteriormente, para resolução. Esses resultados sugerem que o desenvolvimento da resposta imune não é preponderante no controle da infecção induzida pela Leishmania mexicana inoculada subcutaneamente na bolsa jugal do hamster. Sugerem ainda que os macrófagos que compõe os granulomas leishmanióticos são capazes de eliminar esse parasita, independente da presença de resposta imune avaliável pelo teste do coxim plantar. Abstract in english We have studied the role of the immune response in the morphology of the leishmaniotic granuloma induced in the cheek pouch of hamsters, an immunologically privileged site, after inoculation of 3 x 10(5) Leishmania mexicana. Animals were histologically and immunologically evaluated until 120 days after inoculation. Independent of the time of sacrifice, the animals were always non-reactors to the footpad test (FPT). At histology, the introduction of L. mexicana in the chee (more) k pouch leads to an abscess that evolves to a granulomatous reaction rich in amastigote forms, and later it leads to resolution, even in the absence of immune response detectable by FPT. Our results demonstrate that the development of immune response is not preponderant for the control of infection induced by L. mexicana inoculated subcutaneously in the cheek pouch of the hamster. It also suggests that the macrophages present in the leishmaniotic granuloma are capable of eliminating this parasite, even in the absence of immune response evaluated by FPT.

Arruda, Maria Sueli Parreira de; Nogueira, Maria Esther Salles; Bordon, Ana Paula

2002-08-01

160

Histological evaluation of the lesion induced by inoculation of Leishmania mexicana in the cheek pouch of the hamster Avaliação histológica da lesão induzida pela inoculação de Leishmania mexicana na bolsa jugal do hamster  

Directory of Open Access Journals (Sweden)

Full Text Available We have studied the role of the immune response in the morphology of the leishmaniotic granuloma induced in the cheek pouch of hamsters, an immunologically privileged site, after inoculation of 3 x 10(5) Leishmania mexicana. Animals were histologically and immunologically evaluated until 120 days after inoculation. Independent of the time of sacrifice, the animals were always non-reactors to the footpad test (FPT). At histology, the introduction of L. mexicana in the cheek pouch leads to an abscess that evolves to a granulomatous reaction rich in amastigote forms, and later it leads to resolution, even in the absence of immune response detectable by FPT. Our results demonstrate that the development of immune response is not preponderant for the control of infection induced by L. mexicana inoculated subcutaneously in the cheek pouch of the hamster. It also suggests that the macrophages present in the leishmaniotic granuloma are capable of eliminating this parasite, even in the absence of immune response evaluated by FPT.No presente estudo, investigamos o papel da resposta imune na morfologia do granuloma leishmaniótico induzido na bolsa jugal do hamster, um local imunologicamente privilegiado, após inoculação de 3x10(5) Leishmania mexicana. Os animais foram avaliados histológica e imunologicamente até os 120 dias da inoculação. Independente da época do sacrifício, os animais foram sempre não reatores ao teste do coxim plantar. Histologicamente, a inoculação de Leishmania mexicana na bolsa jugal resultou na formação de abcesso que evoluiu para reação granulomatosa rica em formas amastigotas e, posteriormente, para resolução. Esses resultados sugerem que o desenvolvimento da resposta imune não é preponderante no controle da infecção induzida pela Leishmania mexicana inoculada subcutaneamente na bolsa jugal do hamster. Sugerem ainda que os macrófagos que compõe os granulomas leishmanióticos são capazes de eliminar esse parasita, independente da presença de resposta imune avaliável pelo teste do coxim plantar.

Maria Sueli Parreira de Arruda; Maria Esther Salles Nogueira; Ana Paula Bordon

2002-01-01

 
 
 
 
161

Leishmaniose tegumentar americana causada por Leishmania (Viannia) braziliensis, em área de treinamento militar na Zona da Mata de Pernambuco  

Directory of Open Access Journals (Sweden)

Full Text Available Este estudo tem como objetivo geral caracterizar a epidemiologia da leishmaniose tegumentar americana em unidade de treinamento militar, localizada no Estado de Pernambuco. Entre 2002 e 2003, vinte e três casos foram diagnosticados através de exame clínico, detecção do parasita e teste de intradermoarreação de Montenegro. Sete amostras de Leishmania (Viannia) braziliensis foram isoladas destes pacientes, identificadas através de reações com anticorpos monoclonais específicos e perfil eletroforético com isoenzimas. Um inquérito epidemiológico de prevalência da infecção por IDRM foi realizado na população que realizou treinamento neste período, no qual foi identificada uma prevalência de 25,3% de infecção. Os dados obtidos, associados com achados prévios nesta área, apresentam evidências da manutenção de um ciclo enzoótico, com a ocorrência de surtos periódicos de leishmaniose tegumentar americana posteriormente à realização de treinamentos nas áreas de floresta Atlântica remanescente.

Andrade Maria S.; Brito Maria E. F.; Silva Salomão Thomaz da; Lima Bruna S.; Almeida Éricka L.; Albuquerque Elisângela L.; Marinho Júnior José F.; Ishikawa Edna; Cupolillo Elisa; Brandão-Filho Sinval P.

2005-01-01

162

Immunogold labeling and cerium cytochemistry of the enzyme ecto-5'-nucleotidase in promastigote forms of Leishmania species  

Directory of Open Access Journals (Sweden)

Full Text Available We have applied both enzyme cytochemistry and immunological labeling techniques to characterize the enzyme 5'-nucleotidase (5'-Nase), at the ultrastructural level, in promastigote forms of four Leishmania species: Leishmania amazonensis, Leishmania mexicana, Leishmania donovani and Leishmania chagasi. The cerium phosphate staining was localized at the surface of the cell body, the flagellum and the flagellar pocket membranes of all the parasites studied. The immunogold labelling technique confirmed these results. In this report we localized 5'-Nase in L. chagasi and L. amazonensis which have been implicated respectively in visceral and cutaneous forms of leishmaniasis. In addition, we confirmed the localization of this phosphomonoesterase in the other two species studied. The superior quality of the images, obtained with both methodologies, confirms that these parasites possess mechanisms capable of hydrolyzing nucleotide monophosphates, and that the expression of 5'-Nase is associated with the outer surface of the plasma membrane.

Suzana Corte-Real; Renato Porrozzi; Maria de Nazareth Leal de Meirelles

1993-01-01

163

Effects of seco-steroids purified from Physalis angulata L., Solanaceae, on the viability of Leishmania sp/ Efeitos de seco-esteróides purificados de Physalis angulata L., Solanaceae na viabilidade de Leishmania sp  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Physalis angulata L., Solanaceae, é uma erva anual utilizada na medicina popular em muitos países tropicais e subtropicais. Apesar dos extratos da P. angulata apresentarem uma grande variedade de substâncias, pouco é conhecido sobre a sua atividade farmacológica. Neste trabalho foi investigado a atividade antileishmania in vitro de seco-esteroides (fisalinas) purificados da P. angulata. O tratamento com as fisalinas B, F e G causou uma inibição concentração-depen (more) dente do crescimento de promastigotas de Leishmania amazonensis em cultura axênica, com valores de IC50 de 6,8, 1,4, e 9,2 ?M respectivamente. A fisalina D foi menos ativa, com valores de IC50 de 30,5 ?M. Foi também observada uma atividade leishmanicida em culturas de outras espécies de Leishmania (L. major, L. braziliensis e L. chagasi). Nossos resultados demonstram que as fisalinas inibem o crescimento dos promastigotas com o tratamento de espécies de Leishmania do Velho e do Novo Mundos e sugerem o potencial terapêutico destas moléculas na leishmaniose. Abstract in english Physalis angulata L., Solanaceae, is an annual herb commonly used in popular medicine in many tropical and subtropical countries. P. angulata extracts contain a variety of substances, but little is known about their pharmacological activities. In this work we investigated the in vitro antileishmanial activity of seco-steroids (physalins) purified from P. angulata. Addition of physalins B, F, and G caused a concentration-dependent inhibition in the growth of L. amazonensis (more) promastigotes, being the IC50 values were 6.8, 1.4, and 9.2 ?M, respectively. Physalin D was less active and had an IC50 value of 30.5 ?M. Physalins were also active in cultures of other Leishmania species (L. major, L. braziliensis, and L. chagasi). Our results demonstrate the potent antileishmanial activity of physalins in cultures of Leishmania species of the New and Old Worlds and suggest the therapeutic potential of these seco-steroids in leishmaniasis.

Guimarães, Elisalva T.; Lima, Milena S.; Santos, Luana A.; Ribeiro, Ivone M.; Tomassini, Therezinha B. C.; Santos, Ricardo Ribeiro dos; Santos, Washington L. C. dos; Soares, Milena B. P.

2010-12-01

164

Distinctions between promastigotes of Leishmania species developing in the digestive tract of laboratory reared Lutzomyia longipalpis  

Directory of Open Access Journals (Sweden)

Full Text Available Female Lutzomya longipalpis were exposed to infection by three different species/strains of Leishmania. When the insects were dissected four days after exposure, stained preparations were made of the flagellates contained in the digestive tract. Using traditional morphometric methods, L. amazonensis, L. guyanensis and an unnamed species of the mexicana complex could be distinguished from one another.

Ana Lúcia F. F. da Silva; Paul Williams; Maria Norma Melo; Wilson Mayrink

1991-01-01

165

Estudo evolutivo da leishmaniose mucosa (7 a 17 anos de seguimento) causada por Leishmania (Viannia ) braziliensis em Três Braços, Bahia  

Directory of Open Access Journals (Sweden)

Full Text Available No período de agosto a dezembro de 1993 realizou-se um levantamento de 77 pacientes da casuística de leishmaniose mucosa do programa de Três Braços, registrada no período de 1976 a 1986. Encontrou-se 65 pacientes vivos e 12 falecidos. Os primeiros foram submetidos a exame clínico geral e otorrinolaringológico e à pesquisa de anticorpos por imunofluorescência indireta. Os pacientes com lesões ativas foram submetidos à biópsia da mucosa nasal para isolar o parasita em meio de cultura NNN a partir da inoculação direta do material ou das lesões desenvolvidas no hamster e para estudo histopatológico. Todos os isolados foram caracterizados como Leishmania (Viannia) braziliensis utilizando anticoipos monoclonais. Cinqüenta e seis (86%) pacientes estavam curados e nove (13%) encontravam-se com lesões ativas. Entre os pacientes falecidos, cinco (41%) estavam curados no momento do óbito. O programa teve 79% de pacientes curados ao longo de 17 anos. O tempo médio de seguimento clínico foi de 10 anos (7-17 anos). A doença como causa-mortis foi sugerida em 3 casos.Seventy seven (68%) patients with mucosal leishmaniasis recorded during the period 1976- 1986 in the region of Três Braços, Bahia were traced and re-evaluated clinically, diagnostically and therapeutically. Sixty-five patients were alive. The families of 12 dead patients were interviewed about probable cause of death. The 65 patients had a fresh clinical examination supplemented when necessary by a skilled ENT examination. All had a titre of circulating immunofluorescent antibodies estimated at the time. Eight patients with active mucosal lesions had triturated biopsies which were cultivated in NNN medium and inoculated in hamsters to attempt to recover Leishmania. The isolates were identified by monoclonal antibodies as Leishmania (Viannia) braziliensis. Fifty-six (86%) patients were judged clinically cured. Nine (13%) bad active lesions. Of the 12 patients who died 5 (41%) had no signs of activity at death. Mucosal leishmaniasis was thought to be the direct cause of death in 3 patients. The field treatment programme at Três Braços has managed to clinically cure 61 patients (79%) during 17 years. Follow-up periods were a mean of 10 years (range 7-17).

Maria Regina Fernandes de Oliveira; Vanize de Oliveira Macêdo; Edgar Marcelino de Carvalho; Aldina Barral; Jaqueline Guerreiro Marotti; Achiléa Bittencourt; Maria Virgínia Avelar de Abreu; Maria de La Glória Orge Orge; Hélio de Andrade Lessa; Philip Davis Marsden

1995-01-01

166

Estudo evolutivo da leishmaniose mucosa (7 a 17 anos de seguimento) causada por Leishmania (Viannia ) braziliensis em Três Braços, Bahia  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese No período de agosto a dezembro de 1993 realizou-se um levantamento de 77 pacientes da casuística de leishmaniose mucosa do programa de Três Braços, registrada no período de 1976 a 1986. Encontrou-se 65 pacientes vivos e 12 falecidos. Os primeiros foram submetidos a exame clínico geral e otorrinolaringológico e à pesquisa de anticorpos por imunofluorescência indireta. Os pacientes com lesões ativas foram submetidos à biópsia da mucosa nasal para isolar o paras (more) ita em meio de cultura NNN a partir da inoculação direta do material ou das lesões desenvolvidas no hamster e para estudo histopatológico. Todos os isolados foram caracterizados como Leishmania (Viannia) braziliensis utilizando anticoipos monoclonais. Cinqüenta e seis (86%) pacientes estavam curados e nove (13%) encontravam-se com lesões ativas. Entre os pacientes falecidos, cinco (41%) estavam curados no momento do óbito. O programa teve 79% de pacientes curados ao longo de 17 anos. O tempo médio de seguimento clínico foi de 10 anos (7-17 anos). A doença como causa-mortis foi sugerida em 3 casos. Abstract in english Seventy seven (68%) patients with mucosal leishmaniasis recorded during the period 1976- 1986 in the region of Três Braços, Bahia were traced and re-evaluated clinically, diagnostically and therapeutically. Sixty-five patients were alive. The families of 12 dead patients were interviewed about probable cause of death. The 65 patients had a fresh clinical examination supplemented when necessary by a skilled ENT examination. All had a titre of circulating immunofluorescen (more) t antibodies estimated at the time. Eight patients with active mucosal lesions had triturated biopsies which were cultivated in NNN medium and inoculated in hamsters to attempt to recover Leishmania. The isolates were identified by monoclonal antibodies as Leishmania (Viannia) braziliensis. Fifty-six (86%) patients were judged clinically cured. Nine (13%) bad active lesions. Of the 12 patients who died 5 (41%) had no signs of activity at death. Mucosal leishmaniasis was thought to be the direct cause of death in 3 patients. The field treatment programme at Três Braços has managed to clinically cure 61 patients (79%) during 17 years. Follow-up periods were a mean of 10 years (range 7-17).

Oliveira, Maria Regina Fernandes de; Macêdo, Vanize de Oliveira; Carvalho, Edgar Marcelino de; Barral, Aldina; Marotti, Jaqueline Guerreiro; Bittencourt, Achiléa; Abreu, Maria Virgínia Avelar de; Orge Orge, Maria de La Glória; Lessa, Hélio de Andrade; Marsden, Philip Davis

1995-12-01

167

Potential utility of hyperbaric oxygen therapy and propolis in enhancing the leishmanicidal activity of glucantime/ A utilidade da terapia de oxigenação hiperbárica e própolis em potencializar a atividade leishmanicida do glucantime  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Nesse trabalho foi avaliada a eficácia da terapia da oxigenação hiperbárica (HBO), aplicada em combinação ou não com o tratamento com glucantime, durante a infecção com Leishmania amazonensis. O efeito de gel da própolis vermelha de origem brasileira (propaina) aplicado em combinação ou não com o tratamento com glucantime, também foi avaliado durante infecção com esse parasita. A inibição da infecção de macrófagos tratados com glucantime em combinaç? (more) ?o com HBO foi maior que a de macrófagos tratados apenas com glucantime ou HBO. A linhagem murina susceptível, BALB/c, infectada no dorso com L. amazonensis, tratada com glucantime e exposta a HBO, mostrou durante o curso da doença, fases em que as lesões eram menores do que a de camundongos apenas tratados com glucantime; observou-se revascularização da pele da lesão e baixa produção de interferon-gama em células de linfonodos desses animais. O tratamento com propaina não foi eficiente na cura das lesões, apesar de lesões menos exsudativas serem observadas em animais tratados com propaina ou propaina combinada ao tratamento com glucantime. Os resultados demonstram que tanto HBO como a própolis vermelha em combinação com glucantime, são promissoras no tratamento da leishmaniose cutânea. Novos estudos devem ser realizados para avaliar tratamentos e outros protocolos em diferentes modelos murinos da leishmaniose Abstract in english In this study we investigated the efficacy of hyperbaric oxygen (HBO) therapy, alone or combined with the pentavalent antimonial glucantime on Leishmania amazonensis infection. In parallel, the effect of Brazilian red propolis gel (propain) alone or combined with glucantime on L. amazonensis infection was evaluated. The inhibition of the infection in macrophages treated with glucantime in combination with HBO exposition was greater than that of macrophages treated with gl (more) ucantime alone or HBO alone. The susceptible mouse strain BALB/c infected in the shaved rump with L. amazonensis treated with glucantime and exposed to HBO showed: time points in the course of the disease in which lesions were smaller than those of mice treated with glucantime alone and revascularization of the skin in the lesion site; interferon-gamma (IFN-g) levels were not elevated in lymph node cells from these animals. Propain alone was not efficient against lesions, although less exudative lesions were observed in animals treated with propain alone or combined with glucantime. These results reveal the potential value of HBO and red propolis in combination with glucantime for treating cutaneous leishmaniasis and encourage further studies on the effect of more aggressive HBO, propolis and glucantime therapies on different mouse models of leishmaniasis.

Ayres, Diana Copi; Fedele, Thiago Antonio; Marcucci, Maria Cristina; Giorgio, Selma

2011-12-01

168

Potential utility of hyperbaric oxygen therapy and propolis in enhancing the leishmanicidal activity of glucantime A utilidade da terapia de oxigenação hiperbárica e própolis em potencializar a atividade leishmanicida do glucantime  

Directory of Open Access Journals (Sweden)

Full Text Available In this study we investigated the efficacy of hyperbaric oxygen (HBO) therapy, alone or combined with the pentavalent antimonial glucantime on Leishmania amazonensis infection. In parallel, the effect of Brazilian red propolis gel (propain) alone or combined with glucantime on L. amazonensis infection was evaluated. The inhibition of the infection in macrophages treated with glucantime in combination with HBO exposition was greater than that of macrophages treated with glucantime alone or HBO alone. The susceptible mouse strain BALB/c infected in the shaved rump with L. amazonensis treated with glucantime and exposed to HBO showed: time points in the course of the disease in which lesions were smaller than those of mice treated with glucantime alone and revascularization of the skin in the lesion site; interferon-gamma (IFN-g) levels were not elevated in lymph node cells from these animals. Propain alone was not efficient against lesions, although less exudative lesions were observed in animals treated with propain alone or combined with glucantime. These results reveal the potential value of HBO and red propolis in combination with glucantime for treating cutaneous leishmaniasis and encourage further studies on the effect of more aggressive HBO, propolis and glucantime therapies on different mouse models of leishmaniasis.Nesse trabalho foi avaliada a eficácia da terapia da oxigenação hiperbárica (HBO), aplicada em combinação ou não com o tratamento com glucantime, durante a infecção com Leishmania amazonensis. O efeito de gel da própolis vermelha de origem brasileira (propaina) aplicado em combinação ou não com o tratamento com glucantime, também foi avaliado durante infecção com esse parasita. A inibição da infecção de macrófagos tratados com glucantime em combinação com HBO foi maior que a de macrófagos tratados apenas com glucantime ou HBO. A linhagem murina susceptível, BALB/c, infectada no dorso com L. amazonensis, tratada com glucantime e exposta a HBO, mostrou durante o curso da doença, fases em que as lesões eram menores do que a de camundongos apenas tratados com glucantime; observou-se revascularização da pele da lesão e baixa produção de interferon-gama em células de linfonodos desses animais. O tratamento com propaina não foi eficiente na cura das lesões, apesar de lesões menos exsudativas serem observadas em animais tratados com propaina ou propaina combinada ao tratamento com glucantime. Os resultados demonstram que tanto HBO como a própolis vermelha em combinação com glucantime, são promissoras no tratamento da leishmaniose cutânea. Novos estudos devem ser realizados para avaliar tratamentos e outros protocolos em diferentes modelos murinos da leishmaniose

Diana Copi Ayres; Thiago Antonio Fedele; Maria Cristina Marcucci; Selma Giorgio

2011-01-01

169

BODY WEIGHT AS A DETERMINANT OF CLINICAL EVOLUTION IN HAMSTERS (Mesocricetus auratus) INFECTED WITH Leishmania (Viannia) panamensis/ Peso como determinante da evolução clínica em hamsters (Mesocricetus auratus) infectados com Leishmania (Viannia) panamensis  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese RESUMO O resultado clínico da infecção por espécies de Leishmania do subgênero Viannia no modelo de hamster (Mesocricetus auratus) tem se mostrado diferente, dependendo do protocolo experimental. O peso corporal tem sido um importante determinante da evolução clínica da infecção em hamsters com leishmaniose visceral, mas sua importância como parâmetro clínico em hamsters com leishmaniose cutâ (more) nea não é conhecido. Neste estudo, a evolução clínica da infecção com L. (V) panamensis foi avaliada em jovens e adultos hamsters machos durante 11 semanas, comparando os parâmetros clínicos tais como a atitude, a temperatura, a frequência respiratória, a aparência das fezes, e o peso corporal entre infectado e grupos não infectados. Os resultados mostraram que o peso corporal diminuiu em hamsters adultos após infecção por L. (V) panamensis. Esta observação suporta a utilização do peso corporal, como um parâmetro adicional para definir a administração ou o tratamento de leishmaniose cutânea em hamsters adultos infectados usados como modelo animal experimental para a leishmaniose. Abstract in english SUMMARY The clinical outcome of infection with Leishmania species of the subgenus Viannia in hamster model (Mesocricetus auratus) has shown to be different depending on experimental protocol. Body weight has been a relevant determinant of the clinical outcome of the infection in hamsters with visceral leishmaniasis but its importance as a clinical parameter in hamsters with cutaneous leishmaniasis is not known. In this study, the clinical evolution of infection (more) with L. (V) panamensis was evaluated in juvenile and adult male hamsters during 11 weeks by comparing clinical parameters such as attitude, temperature, respiratory rate, appearance of the stool, and body weight between infected and non-infected groups. Results showed that body weight decreased in adult hamsters after infection by L. (V) panamensis; this observation supports the use of body weight as an additional parameter to define the management or treatment of cutaneous leishmaniasis in infected adult hamsters used as an animal experimental model for leishmaniasis.

Gomez-Galindo, Angela Maria; Delgado-Murcia, Lucy Gabriela

2013-09-01

170

The in vitro leishmanicidal activity of hexadecylphosphocholine (miltefosine) against four medically relevant Leishmania species of Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available The in vitro leishmanicidal activity of miltefosine® (Zentaris GmbH) was assessed against four medically relevant Leishmania species of Brazil: Leishmania (Leishmania) amazonensis, Leishmania (Viannia) braziliensis, Leishmania (Viannia) guyanensis and Leishmania (Leishmania) chagasi. The activity of miltefosine against these New World species was compared to its activity against the Old World strain, Leishmania (Leishmania) donovani, which is known to be sensitive to the effects of miltefosine. The IC50 and IC90 results suggested the New World species harboured similar in vitro susceptibilities to miltefosine; however, miltefosine was approximately 20 times more active against the Old World L. (L.) donovani than against the New World L. (L.) chagasi species. The selectivity index varied from 17.2-28.9 for the New World Leishmania species and up to 420.0 for L. (L.) donovani. The differences in susceptibility to miltefosine suggest that future clinical trials with this drug should include a laboratory pre-evaluation and a dose-defining step.

Eliane de Morais-Teixeira; Quesia Souza Damasceno; Mariana Kolos Galuppo; Alvaro José Romanha; Ana Rabello

2011-01-01

171

The in vitro leishmanicidal activity of hexadecylphosphocholine (miltefosine) against four medically relevant Leishmania species of Brazil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The in vitro leishmanicidal activity of miltefosine® (Zentaris GmbH) was assessed against four medically relevant Leishmania species of Brazil: Leishmania (Leishmania) amazonensis, Leishmania (Viannia) braziliensis, Leishmania (Viannia) guyanensis and Leishmania (Leishmania) chagasi. The activity of miltefosine against these New World species was compared to its activity against the Old World strain, Leishmania (Leishmania) donovani, which is known to be sensitive to the (more) effects of miltefosine. The IC50 and IC90 results suggested the New World species harboured similar in vitro susceptibilities to miltefosine; however, miltefosine was approximately 20 times more active against the Old World L. (L.) donovani than against the New World L. (L.) chagasi species. The selectivity index varied from 17.2-28.9 for the New World Leishmania species and up to 420.0 for L. (L.) donovani. The differences in susceptibility to miltefosine suggest that future clinical trials with this drug should include a laboratory pre-evaluation and a dose-defining step.

Morais-Teixeira, Eliane de; Damasceno, Quesia Souza; Galuppo, Mariana Kolos; Romanha, Alvaro José; Rabello, Ana

2011-06-01

172

In Vitro and In Vivo Activity of a Palladacycle Complex on Leishmania (Leishmania) amazonensis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Leishmaniasis is an important public health problem with an estimated annual incidence of 1.5 million of new human cases of cutaneous leishmaniasis and 500,000 of visceral leishmaniasis. Treatment of the diseases is limited by toxicity and parasite resistance to the drugs currently in use, validatin...

Paladi, Carolina de Siqueira; Pimentel, Isabella Aparecida Salerno; Katz, Simone; Cunha, Rodrigo L. O. R.; Judice, Wagner Alves de Souza

173

Canine visceral leishmaniasis due to Leishmania (L.) infantum chagasi in Amazonian Brazil: comparison of the parasite density from the skin, lymph node and visceral tissues between symptomatic and asymptomatic, seropositive dogs/ Leishmaniose visceral canina causada por Leishmania (L.) infantum chagasi na Amazônia brasileira: comparação da densidade parasitária da pele, linfonodo e vísceras entre cães soropositivos, sintomáticos e assintomáticos  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A leishmaniose visceral canina (LVC) é reconhecida pelas características clínicas da doença e é altamente letal. A infecção, entretanto, pode ser totalmente assintomática em alguns cães soropositivos, o que tem levantado questão polêmica sobre a possibilidade desses animais, serem ou não uma fonte importante da infecção para o flebotomíneo, Lutzomyia longipalpis, o principal vetor da leishmaniose visceral americana (LVA). Neste estudo foram examinados 51 c? (more) ?es com LVC aguda, provenientes de área endêmica de LVA no Estado do Pará, Brasil, e a carga parasitária, formas amastigotas de Leishmania (L.) infantum chagasi, na pele, linfonodo poplíteo e vísceras (fígado e baço) foi comparada com a de nove cães assintomáticos soropositivos (IFAT-IgG). Fragmentos de biópsia desses tecidos obtidos post-mortem foram processados para análise através de imunohistoquímica, usando um anticorpo policlonal contra Leishmania sp. Os testes do Qui-quadrado (X²) e Mann Whitney foram usados para avaliar as médias da densidade de macrófagos infectados (p Abstract in english Canine visceral leishmaniasis (CVL) is recognizable by characteristic signs of disease and is highly lethal. The infection, however, may be quite inapparent in some seropositive dogs, and this has raised the polemic question as to whether or not such animals can be a source of infection for Lutzomyia longipalpis, the vector of American visceral leishmaniasis (AVL). In this study we have examined 51 dogs with acute CVL from an AVL area in Pará State, northern Brazil, and (more) compared the parasite density, amastigotes of Leishmania (L.) infantum chagasi, in the skin, lymph node and viscera of symptomatic with that of nine asymptomatic but seropositive dogs (IFAT-IgG). Post-mortem biopsy fragments of these tissues were processed by immunohistochemistry, using a polyclonal antibody against Leishmania sp. The X² and Mann Whitney tests were used to evaluate the means of infected macrophage density (p

Lima, Luciana Vieira R.; Carneiro, Liliane Almeida; Campos, Marliane Batista; Chagas, Eujênia Janis; Laurenti, Márcia D.; Corbett, Carlos E.P.; Lainson, Ralph; Silveira, Fernando Tobias

2010-10-01

174

Avaliação do teste de aglutinação direta na detecção da infecção por Leishmania (Viannia) braziliensis em possíveis reservatórios de leishmaniose tegumentar americana no estado do Ceará  

Directory of Open Access Journals (Sweden)

Full Text Available Com o objetivo de avaliar a aplicabilidade do Teste de Aglutinação Direta (TAD) como método de detecção da infecção natural canina por Leishmania (Viannia) braziliensis, foi realizado um estudo envolvendo soros de cães residentes em uma área endêmica de leishmaniose tegumentar, Serra de Baturité, CE e soros de cães provenientes da cidade de Curitiba, PR, área não endêmica de leishmaniose. Os resultados obtidos com o TAD neste trabalho indicam a possibilidade do uso deste teste sorológico para levantamentos epidemiólogicos da infecção em reservatórios; neste estudo, o cão doméstico.In order to evaluate the aplicability of the Direct Agglutination Test (DAT) as a method of detection of the natural canine infection for Leishmania (Viannia) braziliensis, it was realized a study involving the serum of naive dogs from Serra de Baturite, Ceara State, an endemic area of cutaneous leishmaniasis, and others from Curitiba, Parana State, a non endemic area. The results indicate the possibility of using this sorologic test to the epidemiologic research of the infection in the reservoir host; in this case, the dog.

Haroldo Sérgio da S. Bezerra; Joseval da Rocha Viana; Maria Jania Texeira; Cristina Sousa Chaves; Daniela Bastos de Araújo; José Hermênio C. Lima Filho

1996-01-01

175

Mefloquina no tratamento da leishmaniose cutânea em uma área endêmica de Leishmania (Viannia) braziliensis Efficacy of mefloquine in the treatment of skin leishmaniasis in an endemic area of Leishmania (Viannia) braziliensis  

Directory of Open Access Journals (Sweden)

Full Text Available O objetivo deste trabalho foi avaliar a eficácia da mefloquina numa região endêmica de leishmaniose cutânea por Leishmania (Viannia) braziliensis, considerando que esta droga de administração oral, eficaz no tratamento da malária, com meia vida prolongada e efeitos colaterais pouco freqüentes poderia ser menos tóxica e de mais fácil administração, quando comparada com os antimoniais pentavalentes. Em Corte de Pedra, no litoral sul do Estado da Bahia, foram tratados, aleatoriamente, dez pacientes portadores de lesões leishmanióticas, subdivididos em dois grupos. O primeiro grupo recebeu mefloquina pela via oral, dose de 250mg/dia, durante seis dias, repetindo-se o mesmo esquema após intervalo de três semanas. O segundo grupo recebeu antimoniato de meglumina (Glucantime®) diariamente, pela via endovenosa, na dose de 20mg/kg por 20 dias. Do grupo da mefloquina só um paciente apresentou cicatrização depois do segundo ciclo. Um desses, com quatro lesões apresentou nova lesão durante o primeiro ciclo de tratamento. A evolução dos outros três foi lenta sendo que em nove semanas nenhum deles tinha cicatrizado as úlceras que permaneciam com grande infiltração e sinais evidentes de atividade. O grupo tratado com Glucantime® apresentou evidente melhora.The aim of this study was to evaluate the efficacy of mefloquine in the treatment of skin leishmaniasis in patients infected with Leishmania (Viannia) braziliensis at an endemic region. Mefloquine is an oral drug effective against malaria with a prolonged half-life, less toxicity and easier administration than pentavalent antimonials. At Corte de Pedra in the Southern litoral of Bahia State, two randomized groups of ten patients with leishmaniasis were treated. The first group was treated with oral mefloquine, 250mg per day in a single dose for six days and repeated three weeks later. The second group received meglumine antimoniate (Glucantime®), 20mg/kg daily administered intravenously for 20 days. Only one patient in the group treated with mefloquine showed evidence of clinical success. During treatment, one patient with four lesions developed a new lesion. The other three patients with clinical leismaniasis did not show evidence of clinical success after nine weeks of treatment. The group treated with Glucantime® showed evident clinical improvement of the skin lesions.

Victor Alberto Laguna-Torres; Carlos A.C. Silva; Dalmo Correia; Edgard M. Carvalho; Albino V. Magalhães; Vanize de Oliveira Macêdo

1999-01-01

176

Leishmania (Viannia) braziliensis is the main species causing cutaneous leishmaniasis in the Federal District of Brazil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The first autochthonous case of American cutaneous leishmaniasis was reported in the Federal District in 1980, and the species involved in this type of leishmaniasis was unknown. This study aimed to identify the species that causes the disease in the Federal District and to investigate its clinical and epidemiological aspects. Between 2000 and 2007, 71 autochthonous cases of leishmaniasis were reported in the Federal District. Leishmania species were identified by means o (more) f direct immunofluorescence reactions using monoclonal antibodies and restriction fragment length polymorphism. The species of 40 (56.33%) out of 71 samples were identified. Thirty-six (90%) were identified as Leishmania (Viannia) braziliensis and four (10%) were identified as Leishmania (Leishmania) amazonensis. In this area, the disease had clinical and epidemiological characteristics similar to those found in other Brazilian regions.

Santos, GM; Kückelhaus, SA; Roselino, AM; Chaer, WK; Sampaio, RNR

2012-01-01

177

Resistance of Leishmania (Leishmania) amazonensis and Leishmania (Viannia) braziliensis to nitric oxide correlates with disease severity in Tegumentary Leishmaniasis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Nitric oxide (NO•) plays a pivotal role as a leishmanicidal agent in mouse macrophages. NO• resistant Escherichia coli and Mycobacterium tuberculosis have been associated with a severe outcome of these diseases. Meth...

Giudice Angela; Camada Ilza; Leopoldo Paulo TG; Pereira Júlia MB; Riley Lee W; Wilson Mary E; Ho John L; de Jesus Amelia

178

Lulo cell line derived from Lutzomyia longipalpis (Diptera: Psychodidae): a novel model to assay Leishmania spp. and vector interaction  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Leishmania (Vianna) braziliensis, Leishmania (Leishmania) amazonensis and Leishmania (Leishmania) chagasi are important parasites in the scenario of leishmaniasis in Brazil. During the life cycle of these parasites, the promastigote forms adhere to the midgut epithelial microvillii of phlebotomine insects to avoid being secreted along with digestive products. Lulo cells are a potential model that will help to understand the features of this adhesion phenomenon. Here, we analyze the interaction between Leishmania spp. promastigotes and Lulo cells in vitro, specifically focusing on adhesion events occurring between three Leishmania species and this cell line. Methods Confluent monolayers of Lulo cells were incubated with promastigotes and adhesion was assessed using both light microscopy and scanning electron microscopy. Findings The results indicate that species from the subgenera Leishmania and Viannia have great potential to adhere to Lulo cells. The highest adherence rate was observed for L. (L.) chagasi after 24 h of incubation with Lulo cells (27.3 ± 1.8% of cells with adhered promastigotes), followed by L. (L.) amazonensis (16.0 ± 0.7%) and L. (V.) braziliensis (3.0 ± 0.7%), both after 48 h. In the ultrastructural analysis, promastigote adherence was also assessed by scanning electron microscopy, showing that, for parasites from both subgenera, adhesion occurs by both the body and the flagellum. The interaction of Lulo cells with Leishmania (L.) chagasi showed the participation of cytoplasmic projections from the former closely associating the parasites with the cells. Conclusions We present evidence that Lulo cells can be useful in studies of insect-parasite interactions for Leishmania species.

Côrtes Luzia MC; Silva Roger MM; Pereira Bernardo AS; Guerra Camila; Zapata Angela C; Bello Felio J; Finkelstein Léa C; Madeira Maria F; Brazil Reginaldo P; Côrte-Real Suzana; Alves Carlos R

2011-01-01

179

Behavior of Leishmania major metacyclic promastigotes during the course of infection and immune response development in resistant versus susceptible hosts/ Comportamento de promastigoteas metacíclicos de Leishmania major durante o curso da infecção e da resposta imune em hospedeiros resistentes versus suscetíveis  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Pouco se conhece sobre os epítopos derivados de promastigotas metacíclicos de Leishmania que são importantes para a regulação ou destruição do parasita, como alvos de ação imunológica no hospedeiro vertebrado. Neste estudo, nós investigamos um método alternativo para obter promastigotas metacíclicos de Leishmania major, pela avaliação do curso da infecção e reação de hipersensibilidade do tipo retardado (HTR) em hospedeiros resistentes e susceptíveis. (more) Promastigotas não-infectantes (procíclicos) de L. major, recentemente isolados de amastigotas, foram selecionados pela adesão a colunas de lã de vidro negativamente carregadas, enquanto que promastigotas metacíclicos não se aderem à coluna e podem ser recuperados com facilidade. Condições ótimas de cromatografia foram validadas por análise estatística. O rendimento médio de parasitas obtidos após separação em colunas de lã de vidro e a viabilidade dos promastigotas foram estimados por microscopia óptica. Os promastigotas metacíclicos tiveram um rendimento médio de 43,5% a 57,5%. Camundongos BALB/c (susceptíveis) e camundongos C57BL/6 (resistentes) apresentaram padrões distintos de lesões cutâneas, os primeiros com lesões mais agressivas, induzidas por promastigotas metacíclicos. As respostas à reação de HTR foram maiores nos grupos de camundongos C57BL/6, submetidos à infecção com promastigotas metacíclicos. Estes resultados indicam que o novo método poderia ser integrado aos protocolos existentes para estudar a metaciclogênese de parasitas do gênero Leishmania in vivo. Abstract in english Little is known on the epitopes derived from metacyclic promastigotes of Leishmania that are important on the regulation or destruction of the parasite, as targets of immune attack in the vertebrate host. In this study we investigated an alternative method to obtain metacyclic promasigotes of Leishmania major, as evaluated by the course of infection and delayed-type hipersensitivity (DTH) in resistant versus susceptible inbred mice. Non-infective (procyclic) promastigotes (more) of L. major recently transformed from tissue amastigotes were attached to a negatively charged glass-wool column, whereas metacyclic promastigotes were not bound to columns and could be easily recovered. Optimal chromatography conditions were validated through statistical analyses. Parasite average yield from glass wool columns and promastigote viability were estimated by light microscopy. Metacyclic promastigotes yielded 43.5% to 57.5%. Different patterns of cutaneous lesions were obtained in BALB/c (susceptible) and C57BL/6 (resistant) mice, the former with highly infective lesions induced by metacyclic promastigotes. DTH responses proved to be higher in groups of C57BL/6 mice which were infected with metacyclic promastigotes. These results indicate that the new method could be integrated with the investigation of metacyclogenesis of Leishmania in vivo.

Dórea, Regina Coeli Cunha; Barboza-Filho, Carlos Gomes; Moreira, Dayson Friaça; Guirro, Mirian; Chaves, Ágtha de Alencar Muniz; Dunder, Ricardo José; Soares, Elaine Amorim; Santos-Júnior, Vitório; Spinosa, Wilma

2003-11-01

180

Behavior of Leishmania major metacyclic promastigotes during the course of infection and immune response development in resistant versus susceptible hosts Comportamento de promastigoteas metacíclicos de Leishmania major durante o curso da infecção e da resposta imune em hospedeiros resistentes versus suscetíveis  

Directory of Open Access Journals (Sweden)

Full Text Available Little is known on the epitopes derived from metacyclic promastigotes of Leishmania that are important on the regulation or destruction of the parasite, as targets of immune attack in the vertebrate host. In this study we investigated an alternative method to obtain metacyclic promasigotes of Leishmania major, as evaluated by the course of infection and delayed-type hipersensitivity (DTH) in resistant versus susceptible inbred mice. Non-infective (procyclic) promastigotes of L. major recently transformed from tissue amastigotes were attached to a negatively charged glass-wool column, whereas metacyclic promastigotes were not bound to columns and could be easily recovered. Optimal chromatography conditions were validated through statistical analyses. Parasite average yield from glass wool columns and promastigote viability were estimated by light microscopy. Metacyclic promastigotes yielded 43.5% to 57.5%. Different patterns of cutaneous lesions were obtained in BALB/c (susceptible) and C57BL/6 (resistant) mice, the former with highly infective lesions induced by metacyclic promastigotes. DTH responses proved to be higher in groups of C57BL/6 mice which were infected with metacyclic promastigotes. These results indicate that the new method could be integrated with the investigation of metacyclogenesis of Leishmania in vivo.Pouco se conhece sobre os epítopos derivados de promastigotas metacíclicos de Leishmania que são importantes para a regulação ou destruição do parasita, como alvos de ação imunológica no hospedeiro vertebrado. Neste estudo, nós investigamos um método alternativo para obter promastigotas metacíclicos de Leishmania major, pela avaliação do curso da infecção e reação de hipersensibilidade do tipo retardado (HTR) em hospedeiros resistentes e susceptíveis. Promastigotas não-infectantes (procíclicos) de L. major, recentemente isolados de amastigotas, foram selecionados pela adesão a colunas de lã de vidro negativamente carregadas, enquanto que promastigotas metacíclicos não se aderem à coluna e podem ser recuperados com facilidade. Condições ótimas de cromatografia foram validadas por análise estatística. O rendimento médio de parasitas obtidos após separação em colunas de lã de vidro e a viabilidade dos promastigotas foram estimados por microscopia óptica. Os promastigotas metacíclicos tiveram um rendimento médio de 43,5% a 57,5%. Camundongos BALB/c (susceptíveis) e camundongos C57BL/6 (resistentes) apresentaram padrões distintos de lesões cutâneas, os primeiros com lesões mais agressivas, induzidas por promastigotas metacíclicos. As respostas à reação de HTR foram maiores nos grupos de camundongos C57BL/6, submetidos à infecção com promastigotas metacíclicos. Estes resultados indicam que o novo método poderia ser integrado aos protocolos existentes para estudar a metaciclogênese de parasitas do gênero Leishmania in vivo.

Regina Coeli Cunha Dórea; Carlos Gomes Barboza-Filho; Dayson Friaça Moreira; Mirian Guirro; Ágtha de Alencar Muniz Chaves; Ricardo José Dunder; Elaine Amorim Soares; Vitório Santos-Júnior; Wilma Spinosa

2003-01-01

 
 
 
 
181

In vitro interaction between paromomycin sulphate and four drugs with leishmanicidal activity against three New World Leishmania species.  

UK PubMed Central (United Kingdom)

OBJECTIVES: To evaluate in vitro interactions between paromomycin sulphate and the antileishmanial drugs meglumine antimoniate, amphotericin B, miltefosine and azithromycin against intracellular Leishmania (Leishmania) infantum chagasi, Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis amastigotes in peritoneal mouse macrophages. METHODS: First, drug susceptibility was assessed in 3, 5 and 7 day assays, followed by drug interaction assays with a modified fixed-ratio method. An overall mean sum fractional inhibitory concentration (?FIC) was calculated for each combination and each Leishmania species. The nature of the interactions was classified as synergistic if the mean ?FIC was ?0.5, indifferent if the mean ?FIC was >0.5-4.0 and antagonistic if the mean ?FIC was >4.0. RESULTS: In vitro synergism was observed for the combinations of paromomycin plus miltefosine [at 50% and 90% inhibitory concentrations (IC50 and IC90, respectively)] and paromomycin plus amphotericin B (at the IC90 level) against L. (L.) amazonensis, paromomycin plus meglumine antimoniate (at the IC50 and IC90 levels) and paromomycin plus amphotericin B (at the IC50 level) against L. (V.) braziliensis, and paromomycin plus miltefosine, paromomycin plus amphotericin B (both at the IC90 level) and paromomycin plus azithromycin (at the IC50 level) against L. (L) infantum chagasi. CONCLUSIONS: This work provides a preclinical dataset that supports future studies on multidrug treatment schedules against New World leishmaniasis.

de Morais-Teixeira E; Gallupo MK; Rodrigues LF; Romanha AJ; Rabello A

2013-08-01

182

Polymerase chain reaction and real-time PCR for diagnosing of Leishmania infantum chagasi in dogs/ Reação em Cadeia da Polimerase e PCR em tempo real para diagnóstico de Leishmania infantum chagasi em cães  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A importância do cão como reservatório de L. infantum chagasi no meio urbano tem estimulado a realização de inúmeros trabalhos de avaliação de técnicas de diagnóstico, uma vez que este procedimento, quando realizado corretamente, torna-se um importante passo na prevenção da doença em humanos. Dentre os métodos de diagnóstico, as técnicas moleculares têm adquirido destaque. Objetivou-se neste trabalho verificar o desempenho da Reação em Cadeia da Polimer (more) ase (PCR) e da PCR em tempo real (qPCR) para diagnóstico da Leishmaniose Visceral Canina (LVC) utilizando diferentes amostras biológicas. Para tanto foram utilizados 35 cães provenientes de uma área endêmica para LVC, onde foram utilizados para o diagnóstico molecular, aspirado de medula óssea, fragmentos de linfonodo e baço. Neste estudo a qPCR foi capaz de detectar um maior número de animais positivos quando comparada com a PCR. Já entre as diferentes amostras biológicas utilizadas não foi observada diferença significativa na detecção de DNA de L. infantumchagasi por meio da PCR e qPCR. Mesmo assim, considerando a facilidade de obtenção, o linfonodo pode ser considerada como a melhor amostra para diagnóstico molecular da infecção por L. infantum chagasi. Abstract in english The importance of dogs as a reservoir for Leishmania infantumchagasi in urban environments has stimulated numerous studies assessing diagnostic techniques. When performed properly, such procedures are an important step in preventing leishmaniasis in humans. Molecular methods have become prominent for this purpose. The aim of the present study was to determine the performance of the polymerase chain reaction (PCR) and real-time PCR (qPCR) for diagnosing of canine visceral (more) leishmaniasis (CVL) using different biological samples. For this, 35 dogs from an area endemic for CVL were used. Bone marrow aspirate and lymph node and spleen fragments from these dogs were used for the molecular diagnosis. In the present study, qPCR was able to detect a greater number of positive animals than seen with PCR. Among the different biological samples used, there was no significant difference in L. infantumchagasi DNA detection between PCR and qPCR. However, considering that lymph nodes are easy to acquire, these can be considered to be the best samples for making molecular diagnoses of L. infantum chagasi infection.

Ramos, Rafael Antonio do Nascimento; Ramos, Carlos Alberto do Nascimento; Jusi, Márcia Mariza Gomes; Araújo, Flábio Ribeiro de; Machado, Rosangela Zacarias; Faustino, Maria Aparecida da Glória; Alves, Leucio Câmara

2012-09-01

183

Histopatologia da leishmaniose tegumentar por Leishmania braziliensis braziliensis: 4. Classificação histopatológica Histopathology of Mucocutaneous Leishmaniasis caused by Leishmania braziliensis braziliensis: 4. A histopathological classification  

Directory of Open Access Journals (Sweden)

Full Text Available Os A A. analisaram as alterações histológicas encontradas em 162 casos de Leishmaniose Tegumentar da localidade de Três Braços, Estado da Bahia, dos quais 131 (80,9%) eram de portadores de lesões cutâneas e 31 (19,1%) de portadores de lesões mucosas. Analisaram, também, o comportamento clínico dos cinco padrões histopatológicos, já antes descritos, em relação à terapêutica. O melhor prognóstico esteve sempre ligado ao padrão de Reação Exsudativa e Granulomatosa, ou seja, a uma fase na qual o organismo, tendo lançado mão de um mecanismo endógeno de lise parasitária, já circunscreveu a área de necrose por uma reação granulomatosa, e esta é agora apenas o elemento residual. A ação terapêutica nessa fase somente acelera a resolução natural do caso. O grupo seguinte é amplo, e compreende os casos em que a lesão pertence aos padrões de Reação Exsudativa Celular (formas cutâneas), Reação Exsudativa e Necrótica e Reação Exsudativa e Necrótico-Granulomatosa. Nesses casos, o mecanismo de auto-controle da lesão encontra-se ainda em curso, e a ação terapêutica encurta o período de evolução natural. Os f.asos do padrão de Reação Exsudativa e Tuberculóide tiveram um prognóstico variável. Houve boa resposta à terapêutica quando o granuloma tuberculóide característico desse padrão surgiu em pacientes jovens, com curto tempo de evolução da doença e intradermorreação não exacerbada. Nos demais casos tuberculóides —. principalmente em pacientes adultos, com longo tempo de evolução da doença e intradermorreação exacerbada —, a resposta foi menos satisfatória. Em último lugar, com prognóstico reservado, ficaram os casos da forma mucosa que apresentaram o padrão de Reação Exsudativa Celular, onde o infiltrado pode estar desempenhando papel de auto-agressão. O presente estudo evoluiu para a proposição de uma classificação da Leishmaniose Tegumentar, baseada nos padrões histopatológicos observados. Esta classificação, estritamente morfológica, deverá ser de fácil aplicação para o Patologista e, como apresenta também uma correspondência clínico-evolutiva poderá constituir auxílio valioso ao médico envolvido no diagnóstico e tratamento da Leishmaniose Tegumentar.The Authors have analysed the histopathological alterations observed in 162 cases of Mucocutaneous Leishmaniasis from Três Braços, Bahia, of whom 131 (80,9%) had purely cutaneous lesions and 31 (19,1%) had only mucosal lesions. The clinical behavior of 5 histopathological forms was documented in relation to treatment. The best prognosis was associated with the exudative granulomatous histopathology, a phase where the a host mechanism to use the parasite is evident leading to necrosis and granuloma formation as a residual sign. Therapy in this phase merely hastened the process. In a further large group the lesions were classified as exudative cellular reaction (cutaneous forms), an exudative necrotic reaction and an exudative necrotic gra- nulomatous reaction. In these cases the mechanisms of host defense are still being developed and the effect of therapy is to reduce the time to healing. Cutaneous cases with an exudative tuberculoid reaction had a worse prognosis, although there was a favourable response to treatment if the patient was young, the lesion was of short duration and the intradermal leishmanin test was not exaggerated Lastly are a group of mucosal cases with an exudative cellular reaction where this infiltrate may be a manifestation of auto agression. These cases, also classified as exudative tuberculoid, occur in adult patients with longstanding lesions and an exaggerated leishmanin skin test. They have a poor prognosis. This study develops suggestions for a classification based on the histopathological picture which could be valuable in predicting prognosis and influencing the choice of treatment. This classification is strictly morphological and is easy for the pathologist to apply. It appears to, correspond to the clinical course of the illness

Albino Verçosa de Magalhães; Mario A. P. Moraes; Alberto N. Raick; Alejandro Llanos-Cuentas; Jackson M. L. Costa; César C. Cuba; Philip D. Marsden

1986-01-01

184

Histopatologia da leishmaniose tegumentar por Leishmania braziliensis braziliensis. 3. Reação celular nos tecidos/ Histopathology of mucocutaneous leishmaniasis caused by Leishmania braziliensis brasiliensis. 3. Cellular reaction.  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Os A.A. analisam as alterações histopatológicas observadas em 378 casos de Leishmaniose Tegumentar da localidade de Três Braços Estado da Bahia, dos quais 307 eram de portadores de lesões exclusivamente cutâneas, 54 de portadores de lesões exclusivamnte mucosas e 17 de portadores de lesões cutâneo-mucosas. A infiltração histiolinfoplasmocitária, na maioria dos casos, parece desempenhar o papel de resposta celular inespecífica à presença de um irritante tec (more) idual, porém, nos casos de forma mucosa, não se pode afastar a possibilidade de que esse infiltrado esteja participando de uma reação de tipo autoagressivo. O plasmócito constitui um elemento quase constante nas lesões desenvolvidas, mas não tem sido observado nas lesões residuais, quer em via de cura ou já cicatrizadas; sua presença nestes casos denota, quase sempre, tendência à recidiva. Os mastdcitos foram observados em lesões tanto da forma cutânea como da forma mucosa, mas predominavam nas primeiras. Seu número foi significantemente maior no padrão de Reação Exsudativa e Neerótico Granulomatosa, onde os fenômenos necróticos são bem desenvolvidos. Os eosinófilos apresentaram associação significativa com os mastócitos, confirmando a existência de um eixo bidirecional entre estás duas células, o qual deve participar da modulação inflamatória, na Leishmaniose Tegumentar. Dois tipos de reação granulomatosa foram observados: um desorganizado, em relação, muitas vezes, com a necrose tissular, e outro organizado, mais raro, do tipo tuberculóide. O primeiro foi interpretado como de origem pós-necrótica, surgindo com a redução da carga parasitária, propiciada pelos fenômenos necróticos: eliminado o antígeno e mantidos os níveis de anticorpos, surgem as condições necessárias ao estabelecimento do granuloma, semelhante àquele observado nas lesões por imunocomplexo em excesso de anticorpos. O outro tipo de reação foi o granuloma de células epiteliódes, que surgiu em dois grupos de pacientes. Nos pacientes jovens, com doença de curto tempo de evolução e intradermorreação não exacerbada, este tipo de granuloma talvez seja a expressão da Hipersensibilidade Granulomatosa Específica, descrita por EPSTEIN (1977). No outro grupo de pacientes, havia em todos intradermorreação exacerbada. Nestes casos a hipersensibilidade granulomatosa, associando-se ã hipersensibilidade mediada por células ? agora ampliada pelo seqüestro do antígeno ?, reforçaria o processo granulomatoso, através da reverberação do estímulo antígênico; isso tornaria o tratamento mais difícil e pior o prognóstico para o caso. Abstract in english The Authors analyse the histopathological alterations observed in 378 cases of Mucocutaneous Leishmaniasis from Três Braços, Bahia, of whom 307 (81,4%) were only cutaneous, 54 (14,2%) only mucosae and in 17 (4,4%) both integuments were involved simultaneously. A cellular infiltration of lymphocytes and plasma cells was invariably present in all forms and during healing. In mucosal cases, this reaction may have an important role in maintaining an auto agression in the pr (more) esence of few or no parasites. The plasma cell is a constant ele-ment in well developed lesions but not present in healing lesions. Its presence almost always denotes a tendancy to relapse. Mast cells were observed in both cutaneous and mucosal lesions but predominate in the former. Its number was significantly greater in those with an exudative and necrotic granulomatous reaction where necrotic phenomena are marked. Eosinophils were significantly associated with mast cells suggesting the existence of association between these cells in the modulation of the inflammatory response. Two types of granulomatous reaction were observed: a disorganized one, often related to tissue necrosis, and an organized, tuberculoid type granuloma. The first type is interpreted as of post necrotic origin resulting in a reduction in antigenic load with maintenance of antibody level

Magalhães, Albino Verçosa de; Moraes, Mário A. P.; Raick, Alberto N.; Llanos-Cuentas, Alejandro; Costa, Jackson M. L.; Cuba, César C.; Marsden, Philip D.

1986-10-01

185

Histopatologia da leishmaniose tegumentar por Leishmania braziliensis braziliensis: 4. Classificação histopatológica/ Histopathology of Mucocutaneous Leishmaniasis caused by Leishmania braziliensis braziliensis: 4. A histopathological classification  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Os A A. analisaram as alterações histológicas encontradas em 162 casos de Leishmaniose Tegumentar da localidade de Três Braços, Estado da Bahia, dos quais 131 (80,9%) eram de portadores de lesões cutâneas e 31 (19,1%) de portadores de lesões mucosas. Analisaram, também, o comportamento clínico dos cinco padrões histopatológicos, já antes descritos, em relação à terapêutica. O melhor prognóstico esteve sempre ligado ao padrão de Reação Exsudativa e Gra (more) nulomatosa, ou seja, a uma fase na qual o organismo, tendo lançado mão de um mecanismo endógeno de lise parasitária, já circunscreveu a área de necrose por uma reação granulomatosa, e esta é agora apenas o elemento residual. A ação terapêutica nessa fase somente acelera a resolução natural do caso. O grupo seguinte é amplo, e compreende os casos em que a lesão pertence aos padrões de Reação Exsudativa Celular (formas cutâneas), Reação Exsudativa e Necrótica e Reação Exsudativa e Necrótico-Granulomatosa. Nesses casos, o mecanismo de auto-controle da lesão encontra-se ainda em curso, e a ação terapêutica encurta o período de evolução natural. Os f.asos do padrão de Reação Exsudativa e Tuberculóide tiveram um prognóstico variável. Houve boa resposta à terapêutica quando o granuloma tuberculóide característico desse padrão surgiu em pacientes jovens, com curto tempo de evolução da doença e intradermorreação não exacerbada. Nos demais casos tuberculóides ?. principalmente em pacientes adultos, com longo tempo de evolução da doença e intradermorreação exacerbada ?, a resposta foi menos satisfatória. Em último lugar, com prognóstico reservado, ficaram os casos da forma mucosa que apresentaram o padrão de Reação Exsudativa Celular, onde o infiltrado pode estar desempenhando papel de auto-agressão. O presente estudo evoluiu para a proposição de uma classificação da Leishmaniose Tegumentar, baseada nos padrões histopatológicos observados. Esta classificação, estritamente morfológica, deverá ser de fácil aplicação para o Patologista e, como apresenta também uma correspondência clínico-evolutiva poderá constituir auxílio valioso ao médico envolvido no diagnóstico e tratamento da Leishmaniose Tegumentar. Abstract in english The Authors have analysed the histopathological alterations observed in 162 cases of Mucocutaneous Leishmaniasis from Três Braços, Bahia, of whom 131 (80,9%) had purely cutaneous lesions and 31 (19,1%) had only mucosal lesions. The clinical behavior of 5 histopathological forms was documented in relation to treatment. The best prognosis was associated with the exudative granulomatous histopathology, a phase where the a host mechanism to use the parasite is evident leadi (more) ng to necrosis and granuloma formation as a residual sign. Therapy in this phase merely hastened the process. In a further large group the lesions were classified as exudative cellular reaction (cutaneous forms), an exudative necrotic reaction and an exudative necrotic gra- nulomatous reaction. In these cases the mechanisms of host defense are still being developed and the effect of therapy is to reduce the time to healing. Cutaneous cases with an exudative tuberculoid reaction had a worse prognosis, although there was a favourable response to treatment if the patient was young, the lesion was of short duration and the intradermal leishmanin test was not exaggerated Lastly are a group of mucosal cases with an exudative cellular reaction where this infiltrate may be a manifestation of auto agression. These cases, also classified as exudative tuberculoid, occur in adult patients with longstanding lesions and an exaggerated leishmanin skin test. They have a poor prognosis. This study develops suggestions for a classification based on the histopathological picture which could be valuable in predicting prognosis and influencing the choice of treatment. This classification is strictly morphological and is easy for the pathologist to apply. It ap

Magalhães, Albino Verçosa de; Moraes, Mario A. P.; Raick, Alberto N.; Llanos-Cuentas, Alejandro; Costa, Jackson M. L.; Cuba, César C.; Marsden, Philip D.

1986-12-01

186

Action of Bothrops moojeni venom and its L-amino acid oxidase fraction, treated with 60Co gamma rays, in Leishmania spp  

International Nuclear Information System (INIS)

[en] Bothrops moojeni venom showed an anti leishmania activity in vitro, as determined by a cell viability assay using the reduction of MTT. After venom purification, by chromatography techniques, the fractions with anti leishmania and L-amino acid oxidase activities, eluted in the same positions. The molecular weight of the enzyme was estimated to be 140 kDa by molecular exclusion chromatography, and 69 kDa, by SDS-PAGE, migrating as a single band, with an isoelectric point of 4.8 as determined by isoelectric focusing. The purified LAO from B. moojeni venom, 135-fold more active than crude venom, showed homo dimeric constitution, and was active against Leishmania spp from the New World, with an effective concentration against L(L). amazonensis of 1.80 ?g/ml (EC50), L.(V.) panamensis (0.78 |?g/ml) and L.(L.) chagasi (0.63 (?g/ml). Ultrastructural studies of promastigotes affected by LAO demonstrated cell death, with edema in several organelles such as mitochondria and nuclear membrane, before cell disruption and necrosis. The action of LAO was demonstrated to be hydrogen peroxide-dependent. Studies with LLCMK-2 cells, treated with LAO, showed a toxic effect, with an EC50 of 11|?g/ml. Irradiation of LAO with 60Co gamma rays, did not affect its whole oxidative activity, neither detoxified the enzyme. Amastigotes treated with LAO were not affected by its hydrogen peroxide, otherwise, the exogenous product, killed amastigotes with an EC50 of 0.67mM. These data could be of help in the development of alternative therapeutic approaches to the treatment of leishmaniasis. (author)

1999-01-01

187

Actividad in vitro de la mezcla de alcaloides de Ervatamia coronaria (Jacq) Staff. Apocynaceae sobre amastigotes de Leishmania braziliensis/ Atividade in vitro da mistura de alcalóides de Ervatamia coronaria (Jacq) Staff. Apocynaceae sobre amastigotas de Leishmania braziliensis/ In vitro activity of the alkaloids mixture of Ervatamia coronaria (Jacq) Staff. Apocynaceae on Leishmania braziliensis amastigotes  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A leishmaniose é considerada uma importante causa de morbidade e mortalidade a nível mundial, principalmente nos países tropicais. As formas cutânea e mucocutânea são causadas, entre outras espécies, por Leishmania braziliensis. Na procura de compostos leishmanicidas de origem natural, foi estudada a atividade da mistura de alcalóides de Ervatamia coronaria (Apocynaceae) contra amastigotas de L. braziliensis em 6 concentrações diferentes (1, 10, 20, 25, 50 e 100 (more) µg/mL). Foram tratados macrófagos de ratos da linha J774, infectados com promastigotas de L. braziliensis, com a mistura de alcalóides 1 hora após-infecção e diariamente por 3 dias sem mudança de meio. As experiências de citotoxicidade foram efetuadas sobre os macrófagos com azul tripam. Todos os cultivos foram feitos de forma triplicada e os grupos de controle não foram submetidos à mistura de alcalóides. Foi obtido que o composto adicionado exerce atividade doses/dependente sobre a parasita. No entanto, as concentrações mais altas (50 e 100 µg/mL), adicionado durante 3 dias, mostraram os maiores índices de infecção, provavelmente devido a diminuição no número de macrófagos, sobre os quais não foi observado efeito tóxico do tratamento durante 24 horas DL50/24h = 233,52 µg/mL. Os resultados dessa pesquisa revelaram uma nova atividade farmacológica de alcalóides da espécie Ervatamia coronaria sobre a forma amastigota de Leishmania braziliensis, com IC50 = 2,6 e 12,4 µg/mL sem mostrar toxicidade sobre a célula hospedeira. Abstract in english Leishmaniasis, caused by Leishmania sp., is one of the mean reason of considerable mortality and morbidity throughout the world, especially in the tropics. Cutaneous and mucocutaneous manifestations are caused by Leishmania braziliensis, and the cutaneous form is the most common one in Colombia. In the search for antileishmanial compounds from natural sources, we studied the alkaloids mixture from Ervatamia coronaria against L. braziliensis at six different concentrations (more) (1.0, 10, 20, 25, 50 and 100 µg/mL). Macrophages J774 infected with L. braziliensis were treated with alkaloids one hour, and once a day for three days, after parasitic infection and preserving the same culture medium. Cytotoxicity with trypan blue was undertaken in macrophages J774 by using the same concentrations. Three different cultures samples were carried out. As a control we used medium alone. The alkaloids mix showed a dose/dependent activity on amastigote, but by increasing concentrations from 50 to 100 µg/mL for three days, we saw a high index of infection, probably caused by cellular death. We did not see any toxic effect on macrophages J774 at 100 µg/mL, LD50/24h= 233.52 µg/mL. These results revealed a novel pharmacological activity of alkaloids from E. coronaria against amastigotes of L. braziliensis IC50 = 2.6 and 12.4 µg/mL without toxicity on host cells.

Moreno Rodríguez, Amanda; Robles Camargo, Jorge; Bello García, Felio J.

2008-09-01

188

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

UK PubMed Central (United Kingdom)

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 ?g/mL and 65 ?g/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.

Monte Neto RL; Sousa LM; Dias CS; Barbosa Filho JM; Oliveira MR; Figueiredo RC

2011-01-01

189

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

Science.gov (United States)

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 ?g/mL and 65 ?g/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. PMID:20691682

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

2010-08-05

190

Action of Bothrops moojeni venom and its L-amino acid oxidase fraction, treated with {sup 60}Co gamma rays, in Leishmania spp; Acao do veneno de Bothrops moojeni e sua fracao L-aminoacido oxidase, submetida ao tratamento com raios gama de {sup 60}Co, em Leishmania spp  

Energy Technology Data Exchange (ETDEWEB)

Bothrops moojeni venom showed an anti leishmania activity in vitro, as determined by a cell viability assay using the reduction of MTT. After venom purification, by chromatography techniques, the fractions with anti leishmania and L-amino acid oxidase activities, eluted in the same positions. The molecular weight of the enzyme was estimated to be 140 kDa by molecular exclusion chromatography, and 69 kDa, by SDS-PAGE, migrating as a single band, with an isoelectric point of 4.8 as determined by isoelectric focusing. The purified LAO from B. moojeni venom, 135-fold more active than crude venom, showed homo dimeric constitution, and was active against Leishmania spp from the New World, with an effective concentration against L(L). amazonensis of 1.80 {mu}g/ml (EC{sub 50}), L.(V.) panamensis (0.78 |{mu}g/ml) and L.(L.) chagasi (0.63 ({mu}g/ml). Ultrastructural studies of promastigotes affected by LAO demonstrated cell death, with edema in several organelles such as mitochondria and nuclear membrane, before cell disruption and necrosis. The action of LAO was demonstrated to be hydrogen peroxide-dependent. Studies with LLCMK-2 cells, treated with LAO, showed a toxic effect, with an EC{sub 50} of 11|{mu}g/ml. Irradiation of LAO with 6{sup 0C}o gamma rays, did not affect its whole oxidative activity, neither detoxified the enzyme. Amastigotes treated with LAO were not affected by its hydrogen peroxide, otherwise, the exogenous product, killed amastigotes with an EC{sub 50} of 0.67mM. These data could be of help in the development of alternative therapeutic approaches to the treatment of leishmaniasis. (author)

Cardoso, Andre Gustavo Tempone

1999-07-01

191

Identification of Leishmania chagasi from skin in Leishmania/HIV co-infection: a case report Identificação de Leishmania chagasi na pele em co-infecção Leishmania/HIV: relato de caso  

Directory of Open Access Journals (Sweden)

Full Text Available A case of HIV/Leishmania co-infection presenting both visceral and cutaneous manifestations is reported. Leishmania infection was confirmed by conventional methods (parasitological approach and serology) and by PCR. Leishmania chagasi isolated from the skin lesion was characterized by enzyme electrophoresis and by restriction fragment length polymorphism of the internal transcribed spacer of the ribosomal gene.É descrito um caso de co-infecção leishmania/HIV com manifestações cutâneas e visceral. Infecção pela leishmania foi confirmada através de métodos convencionais (parasitológicos e sorológicos) e através da PCR. A espécie Leishmania chagasi isolada da pele foi caracterizada por eletroforese enzimática e por polimorfismo de fragmento obtido por enzima de restrição.

Marcela Orsini; Marcelo Silva; Zélia Maria Profeta da Luz; Jolandt Disch; Octávio Fernandes; Dalton Moreira; Antonio Carlos Martins Guedes; Ana Rabello

2002-01-01

192

Activity of Brazilian and Bulgarian propolis against different species of Leishmania  

Directory of Open Access Journals (Sweden)

Full Text Available Extracts of propolis samples collected in Brazil and Bulgaria were assayed against four Leishmania species - Leishmania amazonensis, L. braziliensis, L. chagasi from the New World, and L. major from the Old World - associated to different clinical forms of leishmaniasis. The composition of the extracts has been previously characterized by high temperature high resolution gas chromatography coupled to mass spectrometry. Considering the chemical differences among the extracts and the behavior of the parasites, it was observed significant differences in the leishmanicidal activities with IC50/1 day values in the range of 2.8 to 229.3 µg/ml . An overall analysis showed that for all the species evaluated, Bulgarian extracts were more active than the ethanol Brazilian extract. As the assayed propolis extracts have their chemical composition determined it merits further investigation the effect of individual components or their combinations on each Leishmania species.

Gérzia Maria de Carvalho Machado; Leonor Laura Leon; Solange Lisboa de Castro

2007-01-01

193

Leishmania strains causing self-healing cutaneous leishmaniasis have greater susceptibility towards oxidative stress.  

UK PubMed Central (United Kingdom)

The survival of Leishmania parasites within macrophages is influenced by generation of free radicals. To establish whether generation of free radicals influenced chemotherapeutic response, promastigotes from isolates causing self-healing or delayed/non-self-healing cutaneous leishmaniasis (CL) or visceral leishmaniasis (VL) were evaluated for their susceptibility to nitric oxide (NO), antimony and miltefosine. In a self-healing CL strain of Leishmania major (5ASKH), susceptibility to NO and antimony was higher than other species. Likewise, a Leishmania amazonensis strain, M2269, showed greater susceptibility to NO and antimony than other species but no such correlation was observed with miltefosine. Additionally, 5ASKH and M2269 showed poorer free radical scavenging capacity as also their thiol levels were lower than species causing VL. Collectively, our study suggests that self-healing isolates tend to be more susceptible to oxidative stress.

Sarkar A; Ghosh S; Pakrashi S; Roy D; Sen S; Chatterjee M

2012-05-01

194

A novel A2 allele found in Leishmania (Leishmania) infantum chagasi/ Novo alelo do gene A2 descrito em Leishmania (Leishmania) infantum chagasi  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A leishmaniose visceral (LV) é uma zoonose amplamente disseminada, causada no Brasil pela Leishmania (Leishmania) infantum chagasi. Flebotomíneos vetores adquirem o agente etiológico, alimentando-se do sangue de animais contaminados, como cachorros ou animais selvagens. A doença é endêmica no Brasil, e focos de epidemia são relatados em cidades densamente povoadas por todo o país. Muitas manifestações clínicas relacionadas à infecção por Leishmania estão li (more) gadas à relação parasito-hospedeiro, e vários possíveis fatores de virulência dos parasitas, que causam a LV, são alvos de estudo, tais como os genes A2. O gene A2 foi isolado pela primeira vez em 1994 e, em seguida, em 2005, três novos alelos foram descritos em Leishmania (Leishmania) infantum. No presente estudo, um fragmento do gene A2 de uma população clonal de L.(L.) infantum chagasi foi amplificado por PCR e sua sequência de nucleotídeos determinada. O fragmento mostrou 90% de similaridade com alelos do gene A2 de Leishmania (Leishmania) donovani e de L. (L.) infantum, descritos na literatura. Entretanto, a tradução da sequência de nucleotídeos mostra diferenças na sequência de aminoácidos da proteína, que podem ser essenciais em determinar a variabilidade do gene A2 em espécies do complexo L. (L.) donovani e representa uma ferramenta adicional na compreenssão do papel dessa família de genes na virulência e imunidade da leishmaniose visceral. O conhecimento dessa variação é importante para o desenvolvimento de testes diagnósticos mais precisos e ferramentas mais eficazes no controle da doença. Abstract in english Visceral leishmaniasis (VL) is a widely spread zoonotic disease. In Brazil the disease is caused by Leishmania (Leishmania) infantum chagasi. Peridomestic sandflies acquire the etiological agent by feeding on blood of infected reservoir animals, such as dogs or wildlife. The disease is endemic in Brazil and epidemic foci have been reported in densely populated cities all over the country. Many clinical features of Leishmania infection are related to the host-parasite rela (more) tionship, and many candidate virulence factors in parasites that cause VL have been studied such as A2 genes. The A2 gene was first isolated in 1994 and then in 2005 three new alleles were described in Leishmania (Leishmania) infantum. In the present study we amplified by polymerase chain reaction (PCR) and sequenced the A2 gene from the genome of a clonal population of L. (L.) infantum chagasi VL parasites. The L. (L.) infantum chagasi A2 gene was amplified, cloned, and sequenced in. The amplified fragment showed approximately 90% similarity with another A2 allele amplified in Leishmania (Leishmania) donovani and in L.(L.) infantum described in literature. However, nucleotide translation shows differences in protein amino acid sequence, which may be essential to determine the variability of A2 genes in the species of the L. (L.) donovani complex and represents an additional tool to help understanding the role this gene family may have in establishing virulence and immunity in visceral leishmaniasis. This knowledge is important for the development of more accurate diagnostic tests and effective tools for disease control.

Oliveira, Trícia Maria Ferreira de Sousa; Vasconcelos, Elton José Rosas de; Nakaghi, Andréa Cristina Higa; Defina, Tânia Paula Aquino; Jusi, Márcia Mariza Gomes; Baldani, Cristiane Divan; Cruz, Ângela Kaysel; Machado, Rosangela Zacarias

2011-03-01

195

Reproduction of Leishmania (Leishmania ) infantum chagasi in conditioned cell culture growth medium/ Isolamento e crescimento de Leishmania (Leishmania) infantum chagasi em meio de crescimento condicionado de cultura celular  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Leishmânias podem ser produzidas em meio de crescimento condicionado, após o cultivo de células McCoy (MCC). Promastigotas crescidas em meio semi-sólido NNN foram inoculadas em MCC, inicialmente, 100 parasitos por poço com 2,5 mL de McCoyMCC, em placas com 24 poços, sua multiplicação foi observada por uma cinética de 120 horas. Após este tempo, o meio estava saturado de promastigotas. A reprodução das leishmânias foi acompanhada a cada 24 horas, com contagem (more) do número de parasitos por campo fotomicrografado. Como vantagem da técnica do crescimento da leishmânia em MCC tem-se o seu baixo custo, com pequena quantidade de parasitos pode-se obter o aumento da densidade de promastigotas em tempo reduzido. Com o emprego dessa técnica pode-se estudar o comportamento e a multiplicação das leishmânias nos vertebrados e invertebrados, assim como, obter antígenos, tanto brutos (leishmânia) como solúveis, produzidos pelos parasitos, que poderão ser úteis para se desenvolver kits de diagnósticos. Abstract in english Leishmanias can be produced by inoculation in conditioned McCoy cell culture growth medium (CGM). Leishmania (Leishmania) infantum chagasi (100 parasites) grown in NNN medium was inoculated in 2.5 mL CGM, kept in plates (24 wells) and its multiplication was observed for five days (120 hours). After day 5, the medium was saturated with the flagellate forms of the parasite (promastigotes). The reproduction of the leishmanias was observed every 24 hours and the number of par (more) asites was calculated by counting the parasites in a drop of 10 µ L and photomicrographied. So the number of Leishmanias was adjusted to 1 mL volume. The advantage of the technique by isolation of Leishmania in CGM demonstrated in this study is its low cost and high efficacy even with a small quantity of parasites (10² promastigotes) used as inoculum. Additionally, isolation of the leishmania can be obtained together with an increase in their density (180 times) as observed by growth kinetics, within a shorter time. These results justify the use of this low-cost technique for the isolation and investigation of the behavior and multiplication of Leishmania both in vertebrates and invertebrates, besides offering means of obtaining antigens, whether whole antigens (leishmanias) or the soluble antigens produced by the parasites which may be useful for the production of new diagnostic kits.

Nogueira, Yeda L.; Galati, Eunice A.B.

2006-06-01

196

Reproduction of Leishmania (Leishmania ) infantum chagasi in conditioned cell culture growth medium Isolamento e crescimento de Leishmania (Leishmania) infantum chagasi em meio de crescimento condicionado de cultura celular  

Directory of Open Access Journals (Sweden)

Full Text Available Leishmanias can be produced by inoculation in conditioned McCoy cell culture growth medium (CGM). Leishmania (Leishmania) infantum chagasi (100 parasites) grown in NNN medium was inoculated in 2.5 mL CGM, kept in plates (24 wells) and its multiplication was observed for five days (120 hours). After day 5, the medium was saturated with the flagellate forms of the parasite (promastigotes). The reproduction of the leishmanias was observed every 24 hours and the number of parasites was calculated by counting the parasites in a drop of 10 µ L and photomicrographied. So the number of Leishmanias was adjusted to 1 mL volume. The advantage of the technique by isolation of Leishmania in CGM demonstrated in this study is its low cost and high efficacy even with a small quantity of parasites (10² promastigotes) used as inoculum. Additionally, isolation of the leishmania can be obtained together with an increase in their density (180 times) as observed by growth kinetics, within a shorter time. These results justify the use of this low-cost technique for the isolation and investigation of the behavior and multiplication of Leishmania both in vertebrates and invertebrates, besides offering means of obtaining antigens, whether whole antigens (leishmanias) or the soluble antigens produced by the parasites which may be useful for the production of new diagnostic kits.Leishmânias podem ser produzidas em meio de crescimento condicionado, após o cultivo de células McCoy (MCC). Promastigotas crescidas em meio semi-sólido NNN foram inoculadas em MCC, inicialmente, 100 parasitos por poço com 2,5 mL de McCoyMCC, em placas com 24 poços, sua multiplicação foi observada por uma cinética de 120 horas. Após este tempo, o meio estava saturado de promastigotas. A reprodução das leishmânias foi acompanhada a cada 24 horas, com contagem do número de parasitos por campo fotomicrografado. Como vantagem da técnica do crescimento da leishmânia em MCC tem-se o seu baixo custo, com pequena quantidade de parasitos pode-se obter o aumento da densidade de promastigotas em tempo reduzido. Com o emprego dessa técnica pode-se estudar o comportamento e a multiplicação das leishmânias nos vertebrados e invertebrados, assim como, obter antígenos, tanto brutos (leishmânia) como solúveis, produzidos pelos parasitos, que poderão ser úteis para se desenvolver kits de diagnósticos.

Yeda L. Nogueira; Eunice A.B. Galati

2006-01-01

197

Comparison among three polymerase chain reaction assays on detection of DNA from Leishmania in biological samples from patients with american cutaneous leishmaniasis Comparação entre três ensaios de reação em cadeia da polimerase na detecção de DNA de Leishmania, em amostras biológicas de pacientes com leishmaniose tegumentar americana  

Directory of Open Access Journals (Sweden)

Full Text Available INTRODUCTION: The study analyzed positivity of polymerase chain reaction (PCR) on detection of DNA from Leishmania in patients' samples. METHODS: Extracted DNA was submitted to L150/L152, 13Y/13Z, and seminested PCR (snPCR). RESULTS: Results were evidenced by bands of approximately 120, 720, and 670 bp for L150/L152, 13Y/13Z, and snPCR, respectively. L150/L152, 13Y/13Z, and snPCR positivity indexes were 76.9, 56.4, and 9.2 (p>0.05), respectively, for suspected and 93.7, 68.7, and 84.4 (pINTRODUÇÃO: Analisou-se a positividade da reação em cadeia da polimerase (PCR) na detecção de DNA de Leishmania em pacientes. MÉTODOS: DNA extraído foi submetido a L150/L152, 13Y/13Z e PCR seminested (snPCR). RESULTADOS: Resultados foram evidenciados por bandas de aproximadamente 120; 720 e 670pb para L150/L152, 13Y/13Z e snPCR, respectivamente. Positividades para L150/L152, 13Y/13Z e snPCR foram 76,9; 56,4 e 69,2 (p > 0,05), para suspeitos; e 93,7; 68,7 e 84,4 (p < 0,05) para confirmados, respectivamente. CONCLUSÕES: Resultados preliminares mostraram que os ensaios, principalmente L150/L152 e snPCR, podem detectar DNA de Leishmania e têm potencial para diagnóstico laboratorial das leishmanioses.

João Guilherme Lino da Silva; Thiago Miranda da Silva; Eduardo de Figueiredo Peloso; George Luiz Lins Machado-Coelho; Wilson Mayrink; Marília Caixeta Franco Ariosa; Paulo Márcio de Faria e Silva; Marcos José Marques

2012-01-01

198

Comparison among three polymerase chain reaction assays on detection of DNA from Leishmania in biological samples from patients with american cutaneous leishmaniasis/ Comparação entre três ensaios de reação em cadeia da polimerase na detecção de DNA de Leishmania, em amostras biológicas de pacientes com leishmaniose tegumentar americana  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese INTRODUÇÃO: Analisou-se a positividade da reação em cadeia da polimerase (PCR) na detecção de DNA de Leishmania em pacientes. MÉTODOS: DNA extraído foi submetido a L150/L152, 13Y/13Z e PCR seminested (snPCR). RESULTADOS: Resultados foram evidenciados por bandas de aproximadamente 120; 720 e 670pb para L150/L152, 13Y/13Z e snPCR, respectivamente. Positividades para L150/L152, 13Y/13Z e snPCR foram 76,9; 56,4 e 69,2 (p > 0,05), para suspeitos; e 93,7; 68,7 e 84,4 (more) (p Abstract in english INTRODUCTION: The study analyzed positivity of polymerase chain reaction (PCR) on detection of DNA from Leishmania in patients' samples. METHODS: Extracted DNA was submitted to L150/L152, 13Y/13Z, and seminested PCR (snPCR). RESULTS: Results were evidenced by bands of approximately 120, 720, and 670 bp for L150/L152, 13Y/13Z, and snPCR, respectively. L150/L152, 13Y/13Z, and snPCR positivity indexes were 76.9, 56.4, and 9.2 (p>0.05), respectively, for suspected and 93.7 (more) , 68.7, and 84.4 (p

Silva, João Guilherme Lino da; Silva, Thiago Miranda da; Peloso, Eduardo de Figueiredo; Machado-Coelho, George Luiz Lins; Mayrink, Wilson; Ariosa, Marília Caixeta Franco; Faria e Silva, Paulo Márcio de; Marques, Marcos José

2012-04-01

199

Características clínicas da leishmaniose tegumentar em crianças de 0 a 5 anos em uma área endêmica de Leishmania (Viannia) braziliensis  

Directory of Open Access Journals (Sweden)

Full Text Available Para caracterizar a clínica da leishmaniose tegumentar em crianças de 0 a 5 anos de idade, foram avaliadas, retrospectivamente, 4.464 fichas clínicas do Centro de Saúde de Corte de Pedra, Presidente Tancredo Neves, Bahia, Brasil, área endêmica de leishmaniose tegumentar americana, entre maio de 1987 e dezembro de 1995. Foram registrados neste período 4.275 casos novos de leishmaniose, dos quais, 491 (11,5%) correspondiam a crianças de 0 a 5 anos. A razão entre gênero masculino e feminino nas crianças foi 1,1:1. A forma clínica predominante foi a cutânea (98%) e as lesões ulceradas foram as mais freqüentes (99%). A localização das lesões ocorreu, principalmente, acima da cintura (p<0,05), e 35,5% apresentaram lesões múltiplas. A magnitude da doença em crianças, a freqüência semelhante observada em ambos os gêneros e a localização das lesões sugere a possibilidade de transmissão vetorial no domicílio ou peridomicílio.

Ampuero Julia; Macêdo Vanize; Marsden Philip

2006-01-01

200

The role of surface glycoconjugates in Leishmania midgut attachment examined by competitive binding assays and experimental development in sand flies.  

Science.gov (United States)

Binding of promastigotes to the sand fly midgut epithelium is regarded as an essential part of the Leishmania life cycle in the vector. Among Leishmania surface molecules putatively involved in attachment to the sand fly midgut, two GPI-anchored molecules are the most prominent: lipophosphoglycan (LPG) and promastigote surface protease gp63. In this work, we examined midgut attachment of Leishmania lines mutated in GPI-anchored molecules and compared results from 2 different techniques: in vivo development in sand flies and in vitro competitive binding assays using fluorescently labelled parasites. In combination with previous studies, our data provide additional support for (1) an LPG-independent parasite-binding mechanism of Leishmania major within the midgut of the permissive vector Phlebotomus perniciosus, and provide strong support for (2) the crucial role of L. major LPG in specific vector Phlebotomus papatasi, and (3) a role for Leishmania amazonensis gp63 in Lutzomyia longipalpis midgut binding. Moreover, our results suggest a critical role for GPI-anchored proteins and gp63 in Leishmania mexicana attachment to L. longipalpis midguts, as the wild type (WT) line accounted for over 99% of bound parasites. PMID:23611086

Jecna, Lucie; Dostalova, Anna; Wilson, Ray; Seblova, Veronika; Chang, Kwang-Poo; Bates, Paul A; Volf, Petr

2013-04-23

 
 
 
 
201

Anti-leishmania activity of semi-purified fraction of Jacaranda puberula leaves.  

UK PubMed Central (United Kingdom)

The crude methanolic extract from leaves of Jacaranda puberula showed activity against Leishmania (Leishmania) amazonensis. The extract presented active against promastigote forms with an inhibitory concentration 50% (IC(50)) value of 88.0 mug/ml, but only moderated activity against amastigote forms; however in higher concentrations the extract showed cytotoxic effects. The bio-guided chromatographic fractionation the crude methanolic extract against amastigotes yielded a fraction with an IC(50) value of 14.0 mug/ml (without cytotoxic activity) in relation to the crude extract (IC(50) value, 359.0 microg/ml). These data indicate that J. puberula leaves contain active compounds, which should be further investigated for the development of new potential drugs against cutaneous leishmaniasis.

Passero LF; Castro AA; Tomokane TY; Kato MJ; Paulinetti TF; Corbett CE; Laurenti MD

2007-08-01

202

Anti-leishmania activity of semi-purified fraction of Jacaranda puberula leaves.  

Science.gov (United States)

The crude methanolic extract from leaves of Jacaranda puberula showed activity against Leishmania (Leishmania) amazonensis. The extract presented active against promastigote forms with an inhibitory concentration 50% (IC(50)) value of 88.0 mug/ml, but only moderated activity against amastigote forms; however in higher concentrations the extract showed cytotoxic effects. The bio-guided chromatographic fractionation the crude methanolic extract against amastigotes yielded a fraction with an IC(50) value of 14.0 mug/ml (without cytotoxic activity) in relation to the crude extract (IC(50) value, 359.0 microg/ml). These data indicate that J. puberula leaves contain active compounds, which should be further investigated for the development of new potential drugs against cutaneous leishmaniasis. PMID:17390147

Passero, L F D; Castro, A A; Tomokane, T Y; Kato, M J; Paulinetti, T F; Corbett, C E P; Laurenti, M D

2007-03-28

203

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 gr...

Camila Lehnhardt Pires; Selma Dzimidas Rodrigues; Daniel Bristot; Henrique Hessel Gaeta; Daniela de Oliveira Toyama

204

Expresión heteróloga de ARN mensajeros de Leishmania en ovocitos de anfibios  

Directory of Open Access Journals (Sweden)

Full Text Available La técnica de expresión heteróloga en ovocitos de Xenopus laevis ha sido ampliamente utilizada para la caracterización funcional de canales iónicos. En este estudio se reporta el uso del modelo nativo de ovocitos de Bufo marinus para la expresión heteróloga de ARN poliadenilado (ARNm poli(A)+) de Leishmania amazonensis y la posterior identificación de canales iónicos mediante registros electrofisiológicos utilizando la técnica de voltaje controlado (voltage-clamp). Se logró realizar la maduración, extracción y cultivo de ovocitos de B. marinus bajo condiciones similares a las estandarizadas para X. laevis. El potencial de reposo promedio así como las corrientes endógenas mostraron ser definidas por canales de cloruro dependientes de calcio y rectificadores de salida, de manera similar a lo reportado en X. laevis. La inyección de ARNm poli(A)+ de L. amazonensis generó la expresión de corrientes de cloruro de  amplitud, cinética y características farmacológicas diferentes a las corrientes endógenas, reportadas en estudios previos con X. laevis como posible resultado de la expresión heteróloga de canales iónicos de L. amazonensis.

Arroyo Olarte Rubén Darío; Camacho Navarro María Marcela

2006-01-01

205

Clinical profile of naturally infected dogs from an endemic area for “Leishmania chagasi” (infantum) in Bahia State, Brazil Quadro clínico de cães infectados naturalmente por Leishmania chagasi em uma área endêmica do estado da Bahia, Brasil  

Directory of Open Access Journals (Sweden)

Full Text Available The purpose of this study was to report a description of the clinical profile of naturally infected dogs from an endemic area for Leishmania chagasi (infantum)-caused visceral leishmaniosis in Brazil, where a wide range of clinical signs are attributed to the infection in dogs. Sixty one dogs, seropositives for anti-L. chagasi antibodies by ELISA, from the urban and peri urban areas of Jequie, in Bahia State were studied. Each clinical sign of disease was recorded. Parasitological diagnosis of Leishmania infection was positive by culture of spleen aspirated samples in 21.3 % (13/61) seropositive dogs, although all of them (100%) were defined as symptomatic by physical examination. A positive statistical correlation was found between seropositivity with high levels of optical density (above 1.0) in ELISA and presence of parasites in culture of spleen aspirates (r=0.8555; p=0.00327), cutaneous disease (p=0.0402), conjunctivitis (p=0.050), enlargement of spleen (p=0.0272) and lameness (p=0.0256). A tendency of lowered red blood cell counts was also found among animals with higher seropositivity. The group of animals with positive parasitological tests presented more mucosal lesions (p=0.0106), apathy (p=0.0469), and leucocytosis with left deviation (p=0.0224). The conjunct of clinical alterations associated to positive serological or parasitological diagnosis for Leishmania chagasi infection were similar to the reported signs of disease caused by L infantum and L. donovani in Old World countries.A leishmaniose visceral canina (LVC) é uma zoonose de importância em Saúde Pública, causada no Novo Mundo pela Leishmania chagasi e é associada a uma doença sistêmica crônica à qual se atribui uma gama variada de sinais clínicos. Foram examinados 61 cães, identificados como soropositivos pelo teste ELISA indireto para anticorpos anti-Leishmania, provenientes do município de Jequié, área endêmica para LVC na Bahia, tendo-se como o objetivo delinear o perfil clínico dos animais infectados. Os caninos foram submetidos ao exame físico e estudo parasitológico por cultivo do parasito em amostras de aspirado esplênico. Todos os cães foram classificados como sintomáticos, sendo 13 positivos ao exame parasitológico. Foi encontrada correlação entre os resultados positivos de cultura esplênica e a densidade óptica obtida no ELISA dos cães estudados (r=0,8555; p=0,00327) e entre os resultados de ELISA e a presença de alterações cutâneas (p=0,0402), conjuntivite (p=0,050), esplenomegalia (p=0,0272) e dificuldade de locomoção (p=0,0256), além de tendência à redução no número de hemácias nos animais. Observaram-se positividade na cultura e alterações das mucosas (p=0,0106), apatia (p=0,0469), aumento de bastonetes (p=0,0224) e leucocitose com desvio à esquerda. O conjunto de sinais clínicos encontrados mostrou-se equivalente aos sinais descritos na literatura em cães infectados por L. infantum e L. donovani nos países do velho mundo.

Paulo Henrique Palis Aguiar; Silvana Ornelas Santos; Alisson Azevedo Pinheiro; Diana Vianna Bittencourt; Rafael Lyra Gaspar da Costa; Fred da Silva Julião; Washington Luis Conrado dos Santos; Stella Maria Barrouin Melo

2007-01-01

206

Leishmanicidal activity of the Agaricus blazei Murill in different Leishmania species.  

UK PubMed Central (United Kingdom)

Leishmaniasis is a major public health problem, and the alarming spread of parasite resistance underlines the importance of discovering new therapeutic products. The present study aims to investigate the in vitro leishmanicidal activity of an Agaricus blazei Murill mushroom extract as compared to different Leishmania species and stages. The water extract proved to be effective against promastigote and amastigote-like stages of Leishmania amazonensis, L. chagasi, and L. major, with IC(50) (50% inhibitory concentration) values of 67.5, 65.8, and 56.8 ?g/mL for promastigotes, and 115.4, 112.3, and 108.4 ?g/mL for amastigotes-like respectively. The infectivity of the three Leishmania species before and after treatment with the water extract was analyzed, and it could be observed that 82%, 57%, and 73% of the macrophages were infected with L. amazonensis, L. major, and L. chagasi, respectively. However, when parasites were pre-incubated with the water extract, and later used to infect macrophages, they were able to infect only 12.7%, 24.5%, and 19.7% of the phagocytic cells for L. amazonensis, L. chagasi, and L. major, respectively. In other experiments, macrophages were infected with L. amazonensis, L. chagasi, or L. major, and later treated with the aforementioned extract, presented reductions of 84.4%, 79.6%, and 85.3% in the parasite burden after treatment. A confocal microscopy revealed the loss of the viability of the parasites within the infected macrophages after treatment with the water extract. The applied extract presented a low cytotoxicity in murine macrophages and a null hemolytic activity in type O(+) human red blood cells. No nitric oxide (NO) production, nor inducible nitric oxide syntase expression, could be observed in macrophages after stimulation with the water extract, suggesting that biological activity may be due to direct mechanisms other than macrophage activation by means of NO production. In conclusion, the results demonstrate that the A. blazei Murill water extract can potentially be used as a therapeutic alternative on its own, or in association with other drugs, to treat Visceral and Cutaneous Leishmaniasis.

Valadares DG; Duarte MC; Oliveira JS; Chávez-Fumagalli MA; Martins VT; Costa LE; Leite JP; Santoro MM; Régis WC; Tavares CA; Coelho EA

2011-12-01

207

Leishmanicidal activity of the Agaricus blazei Murill in different Leishmania species.  

Science.gov (United States)

Leishmaniasis is a major public health problem, and the alarming spread of parasite resistance underlines the importance of discovering new therapeutic products. The present study aims to investigate the in vitro leishmanicidal activity of an Agaricus blazei Murill mushroom extract as compared to different Leishmania species and stages. The water extract proved to be effective against promastigote and amastigote-like stages of Leishmania amazonensis, L. chagasi, and L. major, with IC(50) (50% inhibitory concentration) values of 67.5, 65.8, and 56.8 ?g/mL for promastigotes, and 115.4, 112.3, and 108.4 ?g/mL for amastigotes-like respectively. The infectivity of the three Leishmania species before and after treatment with the water extract was analyzed, and it could be observed that 82%, 57%, and 73% of the macrophages were infected with L. amazonensis, L. major, and L. chagasi, respectively. However, when parasites were pre-incubated with the water extract, and later used to infect macrophages, they were able to infect only 12.7%, 24.5%, and 19.7% of the phagocytic cells for L. amazonensis, L. chagasi, and L. major, respectively. In other experiments, macrophages were infected with L. amazonensis, L. chagasi, or L. major, and later treated with the aforementioned extract, presented reductions of 84.4%, 79.6%, and 85.3% in the parasite burden after treatment. A confocal microscopy revealed the loss of the viability of the parasites within the infected macrophages after treatment with the water extract. The applied extract presented a low cytotoxicity in murine macrophages and a null hemolytic activity in type O(+) human red blood cells. No nitric oxide (NO) production, nor inducible nitric oxide syntase expression, could be observed in macrophages after stimulation with the water extract, suggesting that biological activity may be due to direct mechanisms other than macrophage activation by means of NO production. In conclusion, the results demonstrate that the A. blazei Murill water extract can potentially be used as a therapeutic alternative on its own, or in association with other drugs, to treat Visceral and Cutaneous Leishmaniasis. PMID:21723957

Valadares, Diogo G; Duarte, Mariana C; Oliveira, Jamil S; Chávez-Fumagalli, Miguel A; Martins, Vivian T; Costa, Lourena E; Leite, João Paulo V; Santoro, Marcelo M; Régis, Wiliam C B; Tavares, Carlos A P; Coelho, Eduardo A F

2011-06-24

208

Leishmania mexicana: aspectos taxonómicos y rareza de la infección humana en Três Braços, Bahia, Brasil  

Directory of Open Access Journals (Sweden)

Full Text Available Del estúdio de 51 stocks de Leishmania aislados de pacientes humanos de leishmaniasis cutaneomucosa en Três Braços, Bahia, Brasil, los autores describen, en detalle, el análisis de los dos únicos stocks de L. mexicana, identificando uno de ellos como L. mexicana amazonensis. El otro aislado permanece en posición taxonómica no definida pues considerándosele como un miembro de L. mexicana, encuéntranse dificultades para su identificación subespecífica. Evaluan también los parâmetros biológicos e isoenzimáticos y discuten el papel de los anticuerpos monoclonales en la tipificación de éstos stocks. Los autores remarcan la rareza de la transmisión de parásitos del complejo L. mexicana en esta región, aun cuando estudien epidemiológicamente por mais de 8 anos la infección humana.In a study of 51 stocks of Leishmania isolated from patients with cutaneous leishmaniasis in Três Braços, Bahia, Brazil 49 were characterized as L. braziliensis braziliensis. Only two L. mexicana stocks were identified. One was subspeciated as L. mexicana amazonensis. The other differed from this species and to date remains unspeciated. The biological parameters, isoenzyme analysis and monoclonal antibody findings relating to these two strains are discussed. Transmission of parasites of the mexicana complex to man have been rare in this region during the 8 years of study of the human infection.

César Augusto Cuba Cuba; Air Colombo Barreto; Philip Davis Marsden

1984-01-01

209

Leishmania Exploit Sex  

Science.gov (United States)

Access to the article is free, however registration and sign-in are required. Leishmania are the last of the three major groups of trypanosomatid parasites to give up their secret--a healthy capacity for genetic exchange.

Michael Miles (London School of Hygiene and Tropical Medicine;); Matthew Yeo (London School of Hygiene and Tropical Medicine;); Isabel Mauricio (London School of Hygiene and Tropical Medicine;)

2009-04-10

210

Leishmania replication protein A-1 binds in vivo single-stranded telomeric DNA  

International Nuclear Information System (INIS)

Replication protein A (RPA) is a highly conserved heterotrimeric single-stranded DNA-binding protein involved in different events of DNA metabolism. In yeast, subunits 1 (RPA-1) and 2 (RPA-2) work also as telomerase recruiters and, in humans, the complex unfolds G-quartet structures formed by the 3' G-rich telomeric strand. In most eukaryotes, RPA-1 and RPA-2 bind DNA using multiple OB fold domains. In trypanosomatids, including Leishmania, RPA-1 has a canonical OB fold and a truncated RFA-1 structural domain. In Leishmania amazonensis, RPA-1 alone can form a complex in vitro with the telomeric G-rich strand. In this work, we show that LaRPA-1 is a nuclear protein that associates in vivo with Leishmania telomeres. We mapped the boundaries of the OB fold DNA-binding domain using deletion mutants. Since Leishmania and other trypanosomatids lack homologues of known telomere end binding proteins, our results raise questions about the function of RPA-1 in parasite telomeres

2007-06-29

211

Iron uptake controls the generation of Leishmania infective forms through regulation of ROS levels.  

Science.gov (United States)

During its life cycle, Leishmania undergoes extreme environmental changes, alternating between insect vectors and vertebrate hosts. Elevated temperature and decreased pH, conditions encountered after macrophage invasion, can induce axenic differentiation of avirulent promastigotes into virulent amastigotes. Here we show that iron uptake is a major trigger for the differentiation of Leishmania amazonensis amastigotes, independently of temperature and pH changes. We found that iron depletion from the culture medium triggered expression of the ferrous iron transporter LIT1 (Leishmania iron transporter 1), an increase in iron content of the parasites, growth arrest, and differentiation of wild-type (WT) promastigotes into infective amastigotes. In contrast, LIT1-null promastigotes showed reduced intracellular iron content and sustained growth in iron-poor media, followed by cell death. LIT1 up-regulation also increased iron superoxide dismutase (FeSOD) activity in WT but not in LIT1-null parasites. Notably, the superoxide-generating drug menadione or H(2)O(2) was sufficient to trigger differentiation of WT promastigotes into fully infective amastigotes. LIT1-null promastigotes accumulated superoxide radicals and initiated amastigote differentiation after exposure to H(2)O(2) but not to menadione. Our results reveal a novel role for FeSOD activity and reactive oxygen species in orchestrating the differentiation of virulent Leishmania amastigotes in a process regulated by iron availability. PMID:23382545

Mittra, Bidyottam; Cortez, Mauro; Haydock, Andrew; Ramasamy, Gowthaman; Myler, Peter J; Andrews, Norma W

2013-02-04

212

Iron uptake controls the generation of Leishmania infective forms through regulation of ROS levels.  

UK PubMed Central (United Kingdom)

During its life cycle, Leishmania undergoes extreme environmental changes, alternating between insect vectors and vertebrate hosts. Elevated temperature and decreased pH, conditions encountered after macrophage invasion, can induce axenic differentiation of avirulent promastigotes into virulent amastigotes. Here we show that iron uptake is a major trigger for the differentiation of Leishmania amazonensis amastigotes, independently of temperature and pH changes. We found that iron depletion from the culture medium triggered expression of the ferrous iron transporter LIT1 (Leishmania iron transporter 1), an increase in iron content of the parasites, growth arrest, and differentiation of wild-type (WT) promastigotes into infective amastigotes. In contrast, LIT1-null promastigotes showed reduced intracellular iron content and sustained growth in iron-poor media, followed by cell death. LIT1 up-regulation also increased iron superoxide dismutase (FeSOD) activity in WT but not in LIT1-null parasites. Notably, the superoxide-generating drug menadione or H(2)O(2) was sufficient to trigger differentiation of WT promastigotes into fully infective amastigotes. LIT1-null promastigotes accumulated superoxide radicals and initiated amastigote differentiation after exposure to H(2)O(2) but not to menadione. Our results reveal a novel role for FeSOD activity and reactive oxygen species in orchestrating the differentiation of virulent Leishmania amastigotes in a process regulated by iron availability.

Mittra B; Cortez M; Haydock A; Ramasamy G; Myler PJ; Andrews NW

2013-02-01

213

In vitro and in vivo antileishmanial efficacy of a combination therapy of diminazene and artesunate against Leishmania donovani in BALB/c mice/ Estudo in vitro e in vivo da eficácia anti leishmaniótica de terapêutica combinada de Diminazene e Artesunate contra Leishmania donovani em camundongos Balb/c  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A atividade in vitro e in vivo de Diminazene (Dim), Artezunate (Art) e a combinação Dim e Art (Dim-Art) contra Leishmania donovani foi comparada com a droga de referência Anfotericina B. IC50 da Dim-Art foi 2,28 ± 0,24 µg/mL enquanto aquelas de Dim e Art foram 9,16 ± 0,3 µg/mL e 4,64 ± 0,48 µg/mL respectivamente. O IC50 da Anfotericina B foi 0,16 ± 0,32 µg/mL contra a fase estacionária de promastigotas. A avaliação in vivo do modelo de L. donovani em camundo (more) ngos Balb/c indicou que os tratamentos com a terapêutica de drogas combinadas em doses de 12,5 mg/kg por 28 dias consecutivos significantemente (p Abstract in english The in vitro and in vivo activity of diminazene (Dim), artesunate (Art) and combination of Dim and Art (Dim-Art) against Leishmania donovani was compared to reference drug; amphotericin B. IC50 of Dim-Art was found to be 2.28 ± 0.24 µg/mL while those of Dim and Art were 9.16 ± 0.3 µg/mL and 4.64 ± 0.48 µg/mL respectively. The IC50 for Amphot B was 0.16 ± 0.32 µg/mL against stationary-phase promastigotes. In vivo evaluation in the L. donovani BALB/c mice model indi (more) cated that treatments with the combined drug therapy at doses of 12.5 mg/kg for 28 consecutive days significantly (p

Mutiso, Joshua Muli; Macharia, John Chege; Barasa, Mustafa; Taracha, Evans; Bourdichon, Alain J.; Gicheru, Michael M.

2011-06-01

214

Cloning, Characterization, and Inhibition Studies of a ?-Carbonic Anhydrase from Leishmania donovani chagasi , the Protozoan Parasite Responsible for Leishmaniasis.  

Science.gov (United States)

Leishmaniasis is an infection provoked by protozoans belonging to the genus Leishmania . Among the many species and subsepecies of such protozoa, Leishmania donovani chagasi causes visceral leishmaniasis. A ?-carbonic anhydrase (CA, EC 4.2.1.1) was cloned and characterized from this organism, denominated here LdcCA. LdcCA possesses effective catalytic activity for the CO2 hydration reaction, with kcat of 9.35 × 10(5) s(-1) and kcat/KM of 5.9 × 10(7) M(-1) s(-1). A large number of aromatic/heterocyclic sulfonamides and 5-mercapto-1,3,4-thiadiazoles were investigated as LdcCA inhibitors. The sulfonamides were medium potency to weak inhibitors (KI values of 50.2 nM-9.25 ?M), whereas some heterocyclic thiols inhibited the enzyme with KIs in the range of 13.4-152 nM. Some of the investigated thiols efficiently inhibited the in vivo growth of Leishmania chagasi and Leishmania amazonensis promastigotes, by impairing the flagellar pocket and movement of the parasites and causing their death. The ?-CA from Leishmania spp. is proposed here as a new antileishmanial drug target. PMID:23977960

Syrjänen, Leo; Vermelho, Alane Beatriz; de Almeida Rodrigues, Igor; Corte-Real, Suzana; Salonen, Terhi; Pan, Peiwen; Vullo, Daniela; Parkkila, Seppo; Capasso, Clemente; Supuran, Claudiu T

2013-09-13

215

Coinfección VIH leishmania HIV Leishmania coinfection  

Directory of Open Access Journals (Sweden)

Full Text Available La disminución de las defensas del huésped consecutiva a la Infección por el VIH es la base de las complicaciones oportunistas del. paciente con SIDA; una de éstas puede ser la leishmaniosis visceral, reportada recientemente en Brazil, España e Italia. La infección por Leishmania puede tener lugar antes o después de la infección viral. En las zonas endémicas de leishmaniosis la mayoría de la población adquiere el parásito aunque por lo general no desarrolla la enfermedad; la presencia del VIH puede determinar que una infección subclínica llegue a ser leishmaniosis manifiesta; los clínicos deben estar al tanto de esta probabilidad y solicitar las pruebas de diagnóstico parasitológico en los pacientes infectados por VIH, de modo que puedan sustentar el tratamiento y el seguimiento adecuados de la infección por Leishmania. Esta conducta parece de especial importancia, incluso en pacientes de áreas urbanas, en países donde hay gran aflujo de personas a las zonas endémicas de leishmaniosis. The alterations of host defenses resulting from HIV infection is the basis for the appearance of opportunistic complications; cases of visceral leishmaniosis in HIV-Infected adults have been recently reported from Brazil, Spain and Italy; Leishmania infection may take place before or after the viral one. in the endemic leish. maniosis zones most of the population becomes infected with Leishmania but do not necessarily develop the disease; HIV infection may be a factor leading to clinical leishmaniosis. Clinicians should be aware of this possibility and request adequate parasitological tests on HIV-Infected patients in order to provide the proper treatment and follow-up of leishmaniosis.

Iván Vélez

1992-01-01

216

Estudo clínico randomizado comparando antimoniato de meglumina, pentamidina e anfotericina B para o tratamento da leishmaniose cutânea ocasionada por Leishmania guyanensis A randomized clinical trial comparing meglumine antimoniate, pentamidine and amphotericin B for the treatment of cutaneous leishmaniasis by Leishmania guyanensis  

Directory of Open Access Journals (Sweden)

Full Text Available FUNDAMENTOS: O tratamento da leishmaniose tegumentar americana (LTA) ainda constitui desafio, pois a maioria dos medicamentos é injetável e têm-se poucos ensaios clínicos randomizados comparando a eficácia das drogas. Além disso, é provável que as espécies de Leishmania tenham influência nas respostas terapêuticas. OBJETIVOS: Avaliar e comparar a eficácia e a segurança dos esquemas de tratamento na LTA, ocasionada por Leishmania (Viannia) guyanensis. MÉTODOS: 185 pacientes foram selecionados, conforme critérios de elegibilidade, e distribuídos, aleatoriamente, em 3 grupos - 2 com 74 enfermos e outro com 37 - que receberam, respectivamente, antimoniato de meglumina, isotionato de pentamidina e anfotericina B em doses, períodos e vias de administração padronizados. Os enfermos foram reexaminados um, dois e seis meses após o final dos tratamentos. RESULTADOS: Não houve diferença entre os grupos terapêuticos em relação ao sexo, idade, número ou local das lesões. A análise por intenção de tratar (ITT) mostrou eficácias de 58,1% para a pentamidina e 55,5% para o antimoniato (p=0,857). O grupo da anfotericina B foi analisado separadamente, pois 28 (75,7%) pacientes negaram-se a continuar no estudo após a randomização. Eventos adversos leves ou moderados foram relatados por 74 (40%) pacientes, principalmente artralgia (20,3%), para o grupo do antimoniato, e dor (35,1%) ou enduração (10,8%) no local das injeções para a pentamidina. CONCLUSÕES: A pentamidina tem eficácia similar ao antimonial pentavalente para o tratamento da LTA ocasionada por L. guyanensis. Face aos baixos resultados de eficácia apresentados por ambas as drogas, necessita-se, com urgência, investigar novas opções terapêuticas para esta enfermidade.FUNDAMENTALS: American tegumentary leishmaniasis (ATL) treatment remains a challenge, since most available drugs are injectable and only a small number of comparative, randomized clinical trials have been performed to support their use. Moreover, treatment outcome may depend on the causative species of Leishmania. OBJECTIVES: To evaluate and compare the efficacy and tolerability of meglumine antimoniate, pentamidine isethionate, and amphotericin B in the treatment of ATL caused by Leishmania (Viannia) guyanensis. METHODS: 185 patients were selected according to the eligibility criteria and randomly allocated into three groups - two groups with 74 patients each, and one group with 37 patients, which underwent meglumine, pentamidine and amphotericin B treatment, respectively. Doses, mode of administration and time periods of treatment followed the current recommendations for each drug. Patients were re-examined one, two and six months after completion of treatment. RESULTS: No differences were observed among the therapeutic groups in relation to gender, age, number or site of lesions. Intention-to-treat (ITT) analysis showed efficacy of 58.1% for pentamidine and 55.5% for meglumine (p=0.857). The amphotericin B group was analyzed separately, since 28 patients (75.7%) in this group refused to continue participating in the study. Mild or moderate adverse effects were reported by 74 (40%) patients, especially arthralgia (20.3%) in the meglumine group, and pain (35.1%) or induration (10.8%) at the site of injection in the pentamidine group. CONCLUSION: Pentamidine and meglumine show similar efficacy in the treatment of ATL caused by L. guyanensis. Given the low efficacy of both drugs, there is an urgent need for new therapeutical approaches.

Leandro Ourives Neves; Anette Chrusciak Talhari; Ellen Priscilla Nunes Gadelha; Roberto Moreira da Silva Júnior; Jorge Augusto de Oliveira Guerra; Luiz Carlos de Lima Ferreira; Sinésio Talhari

2011-01-01

217

Estudo clínico randomizado comparando antimoniato de meglumina, pentamidina e anfotericina B para o tratamento da leishmaniose cutânea ocasionada por Leishmania guyanensis/ A randomized clinical trial comparing meglumine antimoniate, pentamidine and amphotericin B for the treatment of cutaneous leishmaniasis by Leishmania guyanensis  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese FUNDAMENTOS: O tratamento da leishmaniose tegumentar americana (LTA) ainda constitui desafio, pois a maioria dos medicamentos é injetável e têm-se poucos ensaios clínicos randomizados comparando a eficácia das drogas. Além disso, é provável que as espécies de Leishmania tenham influência nas respostas terapêuticas. OBJETIVOS: Avaliar e comparar a eficácia e a segurança dos esquemas de tratamento na LTA, ocasionada por Leishmania (Viannia) guyanensis. MÉTODOS (more) : 185 pacientes foram selecionados, conforme critérios de elegibilidade, e distribuídos, aleatoriamente, em 3 grupos - 2 com 74 enfermos e outro com 37 - que receberam, respectivamente, antimoniato de meglumina, isotionato de pentamidina e anfotericina B em doses, períodos e vias de administração padronizados. Os enfermos foram reexaminados um, dois e seis meses após o final dos tratamentos. RESULTADOS: Não houve diferença entre os grupos terapêuticos em relação ao sexo, idade, número ou local das lesões. A análise por intenção de tratar (ITT) mostrou eficácias de 58,1% para a pentamidina e 55,5% para o antimoniato (p=0,857). O grupo da anfotericina B foi analisado separadamente, pois 28 (75,7%) pacientes negaram-se a continuar no estudo após a randomização. Eventos adversos leves ou moderados foram relatados por 74 (40%) pacientes, principalmente artralgia (20,3%), para o grupo do antimoniato, e dor (35,1%) ou enduração (10,8%) no local das injeções para a pentamidina. CONCLUSÕES: A pentamidina tem eficácia similar ao antimonial pentavalente para o tratamento da LTA ocasionada por L. guyanensis. Face aos baixos resultados de eficácia apresentados por ambas as drogas, necessita-se, com urgência, investigar novas opções terapêuticas para esta enfermidade. Abstract in english FUNDAMENTALS: American tegumentary leishmaniasis (ATL) treatment remains a challenge, since most available drugs are injectable and only a small number of comparative, randomized clinical trials have been performed to support their use. Moreover, treatment outcome may depend on the causative species of Leishmania. OBJECTIVES: To evaluate and compare the efficacy and tolerability of meglumine antimoniate, pentamidine isethionate, and amphotericin B in the treatment of ATL (more) caused by Leishmania (Viannia) guyanensis. METHODS: 185 patients were selected according to the eligibility criteria and randomly allocated into three groups - two groups with 74 patients each, and one group with 37 patients, which underwent meglumine, pentamidine and amphotericin B treatment, respectively. Doses, mode of administration and time periods of treatment followed the current recommendations for each drug. Patients were re-examined one, two and six months after completion of treatment. RESULTS: No differences were observed among the therapeutic groups in relation to gender, age, number or site of lesions. Intention-to-treat (ITT) analysis showed efficacy of 58.1% for pentamidine and 55.5% for meglumine (p=0.857). The amphotericin B group was analyzed separately, since 28 patients (75.7%) in this group refused to continue participating in the study. Mild or moderate adverse effects were reported by 74 (40%) patients, especially arthralgia (20.3%) in the meglumine group, and pain (35.1%) or induration (10.8%) at the site of injection in the pentamidine group. CONCLUSION: Pentamidine and meglumine show similar efficacy in the treatment of ATL caused by L. guyanensis. Given the low efficacy of both drugs, there is an urgent need for new therapeutical approaches.

Neves, Leandro Ourives; Talhari, Anette Chrusciak; Gadelha, Ellen Priscilla Nunes; Silva Júnior, Roberto Moreira da; Guerra, Jorge Augusto de Oliveira; Ferreira, Luiz Carlos de Lima; Talhari, Sinésio

2011-12-01

218

In vitro and in vivo antileishmanial efficacy of a combination therapy of diminazene and artesunate against Leishmania donovani in BALB/c mice Estudo in vitro e in vivo da eficácia anti leishmaniótica de terapêutica combinada de Diminazene e Artesunate contra Leishmania donovani em camundongos Balb/c  

Directory of Open Access Journals (Sweden)

Full Text Available The in vitro and in vivo activity of diminazene (Dim), artesunate (Art) and combination of Dim and Art (Dim-Art) against Leishmania donovani was compared to reference drug; amphotericin B. IC50 of Dim-Art was found to be 2.28 ± 0.24 µg/mL while those of Dim and Art were 9.16 ± 0.3 µg/mL and 4.64 ± 0.48 µg/mL respectively. The IC50 for Amphot B was 0.16 ± 0.32 µg/mL against stationary-phase promastigotes. In vivo evaluation in the L. donovani BALB/c mice model indicated that treatments with the combined drug therapy at doses of 12.5 mg/kg for 28 consecutive days significantly (p A atividade in vitro e in vivo de Diminazene (Dim), Artezunate (Art) e a combinação Dim e Art (Dim-Art) contra Leishmania donovani foi comparada com a droga de referência Anfotericina B. IC50 da Dim-Art foi 2,28 ± 0,24 µg/mL enquanto aquelas de Dim e Art foram 9,16 ± 0,3 µg/mL e 4,64 ± 0,48 µg/mL respectivamente. O IC50 da Anfotericina B foi 0,16 ± 0,32 µg/mL contra a fase estacionária de promastigotas. A avaliação in vivo do modelo de L. donovani em camundongos Balb/c indicou que os tratamentos com a terapêutica de drogas combinadas em doses de 12,5 mg/kg por 28 dias consecutivos significantemente (p < 0,001) reduziu a carga parasitária no baço quando comparada a tratamentos com uma única droga dada nas mesmas dosagens. Embora a carga parasitária tenha sido levemente mais baixa (p < 0.05) no grupo Anfotericina B quando comparada com o grupo tratado Dim-Art, o estudo presente demonstra a vantagem positiva do uso potencial da terapêutica combinada Dim-Art sobre drogas como Dim ou Art quando usadas isoladamente. Posterior avaliação é recomendada para determinar a média de combinação mais eficaz dos dois compostos.

Joshua Muli Mutiso; John Chege Macharia; Mustafa Barasa; Evans Taracha; Alain J. Bourdichon; Michael M. Gicheru

2011-01-01

219

Morfometria amastigotica y desarrollo de cuatro aislados de Leishmania mexicana pifanoi de Venezuela em Lutzomyia townsendi Amastigote morphometry and development of 4 isolated of Leishmania mexicana pifanoi of Venesuela in Lutzomyia townsendi  

Directory of Open Access Journals (Sweden)

Full Text Available Utilizando parámetros biométricos de la fase amastigota y el tipo de desarrollo de los parásitos en el flebótomo Lutzomyia townsendi, se han estudiado cuatro aislados de Leishmania obtenidos de pacientes con leishmaniasis cutánea difusa, comparándolos con otros aislados de L. mexicana mexicana y L. braziliensis. Los resultados muestran una estrecha semejanza entre los cuatro aislados de pcientes anérgicos y la L. mexicana mexicana y sugieren que el nombre de L. mexicana pifanoi no parece sostenible; los cuatro aislados, por el contrario, podrían identificarse como L. mexicana amazonensis.By means of morphometric parameters of amastigote stage and the type of development in a susceptible sandfly, four isolates of the so called Leishmania mexicanapifanoi are compared with one of L. mexicana mexicana and other of L. braziliensis. The results indicate that those isolates from diffuse chronic cutaneous lesions show a very close similarity with L. mexicana mexicana and suggest that the name L. mexicana pifanoi seems no to be tenable. These isolates may belong instead to L. mexicana amazonensis.

J. V. Scorza; O. Delgado

1982-01-01

220

Características epidemiológicas da leishmaniose tegumentar americana em uma região endêmica do Estado da Bahia: III. Fauna flebotomínica/ Epidemiological characteristics of American tegumentary leishmaniasis in an endemic region of the State of Bahia: III. Phlebotomine fauna  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A fauna flebotomínica da região de Três Braços, uma área endêmica de leishmaniose cutânea-mucosa localizada no sudeste do Estado da Bahia, na região cacaueira, é muito variada. Foram identificadas 30 espécies de Lutzomyia em 13.535 exemplares coletados entre os anos de 1976 e 1984. Lu. withmani foi a espécie altamente predominante no ambiente peridoméstico e no interior das residências, com percentuais de 99,0 e 97,5, respectivamente. Na floresta, as espécie (more) s predominantes foram Lu. ayrozai e Lu. yuilli, aparecendo Lu. whitmani com apenas 1,0% do total de exemplares examinados. Lu. flaviscutellata, vetor comprovado da Leishmania mexicana amazonensis, foi também coletada em baixos índices. Lu. wellcomei, vetor da L. braziliensis braziliensis na Serra dos Carajás, Pará, Brasil, não foi encontrada na região de Três Braços onde o parasito causando infecções humanas é predominantemente L. b. braziliensis. Embora não se tenha encontrado infecção natural por promastigotas em 1.832 fêmeas de diversas espécies examinadas, discute-se a possibilidade de Lu. whitmani ser um vetor da L.b. braziliensis na região, mantendo, provavelmente, a transmissão entre o cão e o homem. Abstract in english The phlebotomine fauna is highly varied in três Braços, an endemic area american cutaneous leishmaniasis, situated in the cacao growing region in the southeast of Bahia State, brazil. Thirty species of the Lutzomyia genus were identified in 13,535 spcecimens collected between 1976 and 1984. Lutzomyia whitmani was the dominant species accounting for 99% or flies in the periodomicile and 97.5% of those caught in homes. In the forest the predominant species were Lu. ayroza (more) i and Lu. yulli. 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, I.u. 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 mantaining transmission in dogs and man.

Vexenat, Julio A.; Barreto, Air C.; Cuba, César A. Cuba; Marsden, Philip Davis

1986-09-01

 
 
 
 
221

Genomic Organization of Leishmania Species  

Directory of Open Access Journals (Sweden)

Full Text Available Leishmania is a protozoan parasite belonging to the family Trypanosomatidae, which is found among 88 different countries. The parasite lives as an amastigote in vertebrate macro­phages and as a promastigote in the digestive tract of sand fly. It can be cultured in the laboratory us­ing appropriate culture media. Although the sexual cycle of Leishmania has not been observed during the promastigote and amastigote stages, it has been reported by some researchers. Leishma­nia has eukaryotic cell organization. Cell culture is convenient and cost effective, and because posttranslational modifications are common processes in the cultured cells, the cells are used as hosts for preparing eukaryotic recombinant proteins for research. Several transcripts of rDNA in the Leishmania genome are suitable regions for conducting gene transfer. Old World Leishmania spp. has 36 chromosomes, while New World Leishmania spp. has 34 or 35 chromo­somes. The genomic organization and parasitic characteristics have been investigated. Leishmania spp. has a unique genomic organization among eukaryotes; the genes do not have introns, and the chromosomes are smaller with larger numbers of genes confined to a smaller space within the nucleus. Leishmania spp. genes are organized on one or both DNA strands and are transcribed as polycistronic (prokaryotic-like) transcripts from undefined promoters. Regulation of gene expres­sion in the members of Trypanosomatidae differs from that in other eukaryotes. The trans-splic­ing phenomenon is a necessary step for mRNA processing in lower eukaryotes and is observed in Leishmania spp. Another particular feature of RNA editing in Leishmania spp. is that mitochon­drial genes encoding respiratory enzymes are edited and transcribed. This review will discuss the chromosomal and mitochondrial (kinetoplast) genomes of Leishmania spp. as well as the phenome­non of RNA editing in the kinetoplast genome.

B Kazemi

2011-01-01

222

Effect of 3-alkylpyridine marine alkaloid analogues in Leishmania species related to American cutaneous leishmaniasis.  

UK PubMed Central (United Kingdom)

A series of oxygenated analogues of marine 3-alkylpyridine alkaloids were synthesized, and their leishmanicidal activity was assayed. All compounds were prepared from 3-pyridinepropanol in few steps and in good yields. The key step for the synthesis of these compounds was a classic Williamson etherification under phase-transfer conditions. Besides toxicity in peritoneal macrophages, the compounds exhibited a significant leishmanicidal activity. Of twelve compounds tested, five showed a strong leishmanicidal activity against promastigote forms of Leishmania amazonensis and L. braziliensis with IC50 below 10 ?m. Compounds 11, 14, 15, and 16 showed a strong leishmanicidal activity on intracellular amastigotes (IC50 values of 2.78; 0.27; 1.03, and 1.33 ?m, respectively), which is unlikely to be owing to the activation of nitric oxide production by macrophages.

Machado PA; Hilário FF; Carvalho LO; Silveira ML; Alves RB; Freitas RP; Coimbra ES

2012-11-01

223

Effect of 3-alkylpyridine marine alkaloid analogues in Leishmania species related to American cutaneous leishmaniasis.  

Science.gov (United States)

A series of oxygenated analogues of marine 3-alkylpyridine alkaloids were synthesized, and their leishmanicidal activity was assayed. All compounds were prepared from 3-pyridinepropanol in few steps and in good yields. The key step for the synthesis of these compounds was a classic Williamson etherification under phase-transfer conditions. Besides toxicity in peritoneal macrophages, the compounds exhibited a significant leishmanicidal activity. Of twelve compounds tested, five showed a strong leishmanicidal activity against promastigote forms of Leishmania amazonensis and L. braziliensis with IC50 below 10 ?m. Compounds 11, 14, 15, and 16 showed a strong leishmanicidal activity on intracellular amastigotes (IC50 values of 2.78; 0.27; 1.03, and 1.33 ?m, respectively), which is unlikely to be owing to the activation of nitric oxide production by macrophages. PMID:22882996

Machado, Patrícia A; Hilário, Flaviane F; Carvalho, Lidiane O; Silveira, Mariana L T; Alves, Rosemeire B; Freitas, Rossimiriam P; Coimbra, Elaine S

2012-09-10

224

Leishmania (Leishmania) hertigi in a porcupine (Coendou sp.) found in Brasília, Federal District, Brazil/ Leishmania (Leishmania) hertigi em porco-espinho (Coendou sp.) encontrado em Brasília, Distrito Federal, Brasil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Alguns estudos relatam o encontro de Leishmania (Leishmania) hertigi em estados da região Norte do Brasil. Na presente investigação, os autores descrevem o isolamento de Leishmania (Leishmania) hertigi em um porco-espinho (Coendou sp.) encontrado em Brasília, Distrito Federal, região Centro-oeste do Brasil. Durante um estudo de leishmaniose visceral canina conduzido na cidade de Brasília, Distrito Federal, um porco-espinho foi encontrado mort (more) o em via pública. O animal foi identificado e fragmentos de pele íntegra e baço foram coletados para isolamento do parasito em cultura. Esse relato da ocorrência de L. hertigi em outra região do Brasil pode contribuir para evidenciar a distribuição desse parasita no país. Vale ressaltar a necessidade de estudos para compreensão do papel L. hertigi na patologia e patogênese da leishmaniose e a sua sobrevivência em mamíferos e possíveis vetores. Abstract in english Studies report the occurrence of Leishmania (Leishmania) hertigi in northern states of Brazil. In the present investigation, we describe the isolation of L. (L.) hertigi from a porcupine (Coendou sp.) found in Brasília, Federal District, center-west region of Brazil. During a study on canine visceral leishmaniasis conducted in the city of Brasília, Federal District, a porcupine was found dead on a public road. The animal was identified and fragments of intact sk (more) in and spleen were collected for isolation of parasite in the culture. This report of the occurrence of L. hertigi in another part of Brazil may help establish the distribution of this parasite in the country. Further studies are needed to better understand the role of L. hertigi in the pathology and pathogenesis of leishmaniasis and its survival in mammals and possible vectors.

Silva, Denise Amaro da; Madeira, Maria de Fatima; Barbosa Filho, Carlos Jose Lima; Schubach, Edvar Yuri Paheco; Barros, Juliana Helena da Silva; Figueiredo, Fabiano Borges

2013-06-01

225

Leishmania (Leishmania) hertigi in a porcupine (Coendou sp.) found in Brasília, Federal District, Brazil/ Leishmania (Leishmania) hertigi em porco-espinho (Coendou sp.) encontrado em Brasília, Distrito Federal, Brasil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Alguns estudos relatam o encontro de Leishmania (Leishmania) hertigi em estados da região Norte do Brasil. Na presente investigação, os autores descrevem o isolamento de Leishmania (Leishmania) hertigi em um porco-espinho (Coendou sp.) encontrado em Brasília, Distrito Federal, região Centro-oeste do Brasil. Durante um estudo de leishmaniose visceral canina conduzido na cidade de Brasília, Distrito Federal, um porco-espinho foi encontrado mort (more) o em via pública. O animal foi identificado e fragmentos de pele íntegra e baço foram coletados para isolamento do parasito em cultura. Esse relato da ocorrência de L. hertigi em outra região do Brasil pode contribuir para evidenciar a distribuição desse parasita no país. Vale ressaltar a necessidade de estudos para compreensão do papel L. hertigi na patologia e patogênese da leishmaniose e a sua sobrevivência em mamíferos e possíveis vetores. Abstract in english Studies report the occurrence of Leishmania (Leishmania) hertigi in northern states of Brazil. In the present investigation, we describe the isolation of L. (L.) hertigi from a porcupine (Coendou sp.) found in Brasília, Federal District, center-west region of Brazil. During a study on canine visceral leishmaniasis conducted in the city of Brasília, Federal District, a porcupine was found dead on a public road. The animal was identified and fragments of intact sk (more) in and spleen were collected for isolation of parasite in the culture. This report of the occurrence of L. hertigi in another part of Brazil may help establish the distribution of this parasite in the country. Further studies are needed to better understand the role of L. hertigi in the pathology and pathogenesis of leishmaniasis and its survival in mammals and possible vectors.

Silva, Denise Amaro da; Madeira, Maria de Fatima; Barbosa Filho, Carlos José Lima Barbosa; Schubach, Edvar Yuri Paheco; Barros, Juliana Helena da Silva; Figueiredo, Fabiano Borges

2013-03-01

226

Características clínicas da leishmaniose tegumentar em crianças de 0 a 5 anos em uma área endêmica de Leishmania (Viannia) braziliensis/ Clinical findings of tegumentary leishmaniasis in children under five years of age in an endemic area of Leishmania (Viannia) braziliensis  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Para caracterizar a clínica da leishmaniose tegumentar em crianças de 0 a 5 anos de idade, foram avaliadas, retrospectivamente, 4.464 fichas clínicas do Centro de Saúde de Corte de Pedra, Presidente Tancredo Neves, Bahia, Brasil, área endêmica de leishmaniose tegumentar americana, entre maio de 1987 e dezembro de 1995. Foram registrados neste período 4.275 casos novos de leishmaniose, dos quais, 491 (11,5%) correspondiam a crianças de 0 a 5 anos. A razão entre g? (more) ?nero masculino e feminino nas crianças foi 1,1:1. A forma clínica predominante foi a cutânea (98%) e as lesões ulceradas foram as mais freqüentes (99%). A localização das lesões ocorreu, principalmente, acima da cintura (p Abstract in english A retrospective study was performed in a field clinic to characterize the clinical findings of tegumentary leishmaniasis in children from 0 to 5 years old. The clinical records of 4,464 patients were analyzed at the Primary Health Center of Corte de Pedra, Presidente Tancredo Neves, Bahia, Brazil, from May 1987 to December 1995. Four hundred and ninety one (11.8%) children were identified among 4,275 new cases of tegumentary leishmaniasis registered at this Unit. The gend (more) er ratio (M:F) for children under six years was 1.1:1. Cutaneous lesions predominated (98%), mainly skin ulcers (99%) located above the waist (p

Ampuero, Julia; Macêdo, Vanize; Marsden, Philip

2006-02-01

227

Características clínicas da leishmaniose tegumentar em crianças de 0 a 5 anos em uma área endêmica de Leishmania (Viannia) braziliensis Clinical findings of tegumentary leishmaniasis in children under five years of age in an endemic area of Leishmania (Viannia) braziliensis  

Directory of Open Access Journals (Sweden)

Full Text Available Para caracterizar a clínica da leishmaniose tegumentar em crianças de 0 a 5 anos de idade, foram avaliadas, retrospectivamente, 4.464 fichas clínicas do Centro de Saúde de Corte de Pedra, Presidente Tancredo Neves, Bahia, Brasil, área endêmica de leishmaniose tegumentar americana, entre maio de 1987 e dezembro de 1995. Foram registrados neste período 4.275 casos novos de leishmaniose, dos quais, 491 (11,5%) correspondiam a crianças de 0 a 5 anos. A razão entre gênero masculino e feminino nas crianças foi 1,1:1. A forma clínica predominante foi a cutânea (98%) e as lesões ulceradas foram as mais freqüentes (99%). A localização das lesões ocorreu, principalmente, acima da cintura (pA retrospective study was performed in a field clinic to characterize the clinical findings of tegumentary leishmaniasis in children from 0 to 5 years old. The clinical records of 4,464 patients were analyzed at the Primary Health Center of Corte de Pedra, Presidente Tancredo Neves, Bahia, Brazil, from May 1987 to December 1995. Four hundred and ninety one (11.8%) children were identified among 4,275 new cases of tegumentary leishmaniasis registered at this Unit. The gender ratio (M:F) for children under six years was 1.1:1. Cutaneous lesions predominated (98%), mainly skin ulcers (99%) located above the waist (p<0.05). Thirty five percent had multiple lesions. The observed magnitude of the disease in children, the similar proportion of cases in both genders and the location of the lesions suggest the possibility of peri or intradomiciliary transmission.

Julia Ampuero; Vanize Macêdo; Philip Marsden

2006-01-01

228

Infecção natural de Equus asinus por Leishmania braziliensis braziliensis - Bahia, Brasil Natural infection of Equus asinus by Leishmania braziliensis braziliensis - Bahia, Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available Em Corte de Pedra, Valença, Bahia, foi encontrado um jumento (Equus asinus), com infecção natural por Leishmania braziliensis braziliensis. O parasito foi isolado de uma lesão localizada na cicatriz da castração e identificado através de anticorpos monoclonais.In Corte de Pedra, Valença, state of Bahia, a donkey, Equus asinus, was found naturally infected with Leishmania braziliensis braziliensis. The parasite was isolated from a lesion located on a castration scar, and identified by means of monoclonal antibodies.

Julio A. Vexenat; Air C. Barretto; Ana de Cassia O. Rosa; Christiane C. Sales; Albino V. Magalhães

1986-01-01

229

Avaliação do poder sensibilizante da reação de Montenegro  

Directory of Open Access Journals (Sweden)

Full Text Available O teste de Montenegro, utilizado no diagnóstico da leishmaniose tegumentar, tem sido recentemente considerado marcador de imunogenicidade após vacinação. Neste estudo, avaliou-se o poder sensibilizante deste teste e a produção de y-IFN in vitro, em indivíduos não expostos a Leishmania. Utilizaram-se para o teste antígenos de L. amazonensis produzido em nosso laboratório (grupo I) ou produzido pela FIOCRUZ-RJ (grupo II). No dia 30, 33% dos indivíduos do grupo I e 42% do grupo II converteram o teste para positivo, comparando-se com 67% do grupo I e 50% do grupo II no dia 90. y-IFN foi detectado em 56% dos indivíduos do grupo I e 17% do grupo II no dia 30 (169±309 e 11±36pg/ml) e em 67% do grupo I e 58% do grupo II no dia 360 (69±107 e 18±20pg/ml). Estes dados demonstram que o teste de Montenegro induz, além de hipersensibilidade tardia, a produção de y-IFN.

José Fábio Freire; Silva Indiara Maria da; Araújo Maria Ilma; Almeida Roque P.; Bacellar Olívia; Carvalho Edgar M.

2001-01-01

230

Occurrence of Leishmania (Leishmania) chagasi in a domestic cat (Felis catus) in Andradina, São Paulo, Brazil: case report Ocorrência de Leishmania (Leishmania) chagasi em gato doméstico (Felis catus) em Andradina, São Paulo, Brasil: relato de caso  

Directory of Open Access Journals (Sweden)

Full Text Available This work describes natural infection by Leishmania in a domestic cat where amastigote forms of the parasite were observed in the popliteal lymph node imprint. Positive and negative serological reactions were observed by enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence assay (IFA), respectively. Polymerase chain reaction (PCR) revealed that the nucleotide sequence of the sample was identical to Leishmania (L.) chagasi. This is the first report of the disease in felines of the city of Andradina, SP, an area considered endemic for canine and human visceral leishmaniasis.Neste trabalho, é relatada a infecção natural por Leishmania em um gato doméstico no qual, formas amastigotas do parasito foram observadas em imprint de linfonodo poplíteo. Reações sorológicas positivas e negativas foram observadas pelo teste de imunoadsorção enzimática (ELISA) e reação de imunofluorescência indireta (RIFI), respectivamente. A reação em cadeia da polimerase (PCR) revelou que a sequência de nucleotídeos foi idêntica à Leishmania (L.) chagasi. Este é o primeiro relato da doença em felino da cidade de Andradina, Estado de São Paulo, Brasil, área considerada endêmica para leishmaniose visceral canina e humana.

Willian Marinho Dourado Coelho; Valéria Marçal Felix de Lima; Alessandro Francisco Talamini do Amarante; Helio Langoni; Virgínia Bodelão Richini Pereira; Aziz Abdelnour; Katia Denise Saraiva Bresciani

2010-01-01

231

Occurrence of Leishmania (Leishmania) chagasi in a domestic cat (Felis catus) in Andradina, São Paulo, Brazil: case report/ Ocorrência de Leishmania (Leishmania) chagasi em gato doméstico (Felis catus) em Andradina, São Paulo, Brasil: relato de caso  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Neste trabalho, é relatada a infecção natural por Leishmania em um gato doméstico no qual, formas amastigotas do parasito foram observadas em imprint de linfonodo poplíteo. Reações sorológicas positivas e negativas foram observadas pelo teste de imunoadsorção enzimática (ELISA) e reação de imunofluorescência indireta (RIFI), respectivamente. A reação em cadeia da polimerase (PCR) revelou que a sequência de nucleotídeos foi idêntica à Leishmania (L.) ch (more) agasi. Este é o primeiro relato da doença em felino da cidade de Andradina, Estado de São Paulo, Brasil, área considerada endêmica para leishmaniose visceral canina e humana. Abstract in english This work describes natural infection by Leishmania in a domestic cat where amastigote forms of the parasite were observed in the popliteal lymph node imprint. Positive and negative serological reactions were observed by enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence assay (IFA), respectively. Polymerase chain reaction (PCR) revealed that the nucleotide sequence of the sample was identical to Leishmania (L.) chagasi. This is the first report of (more) the disease in felines of the city of Andradina, SP, an area considered endemic for canine and human visceral leishmaniasis.

Coelho, Willian Marinho Dourado; Lima, Valéria Marçal Felix de; Amarante, Alessandro Francisco Talamini do; Langoni, Helio; Pereira, Virgínia Bodelão Richini; Abdelnour, Aziz; Bresciani, Katia Denise Saraiva

2010-12-01

232

Leishmania(Leishmania) chagasi in captive wild felids in Brazil.  

UK PubMed Central (United Kingdom)

This study used a PCR-RFLP test to determine the presence of Leishmania (Leishmania) chagasi in 16 captive wild felids [seven Puma concolor (Linnaeus, 1771); five Panthera onca (Linnaeus, 1758) and four Leopardus pardalis (Linnaeus, 1758)] at the zoological park of the Federal University of Mato Grosso, Brazil. Amplification of Leishmania spp. DNA was seen in samples from five pumas and one jaguar, and the species was characterized as L. chagasi using restriction enzymes. It is already known that domestic felids can act as a reservoir of L. chagasi in endemic areas, and further studies are necessary to investigate their participation in the epidemiological chain of leishmaniasis.

Dahroug MA; Almeida AB; Sousa VR; Dutra V; Turbino NC; Nakazato L; de Souza RL

2010-01-01

233

Leishmania(Leishmania) chagasi in captive wild felids in Brazil.  

Science.gov (United States)

This study used a PCR-RFLP test to determine the presence of Leishmania (Leishmania) chagasi in 16 captive wild felids [seven Puma concolor (Linnaeus, 1771); five Panthera onca (Linnaeus, 1758) and four Leopardus pardalis (Linnaeus, 1758)] at the zoological park of the Federal University of Mato Grosso, Brazil. Amplification of Leishmania spp. DNA was seen in samples from five pumas and one jaguar, and the species was characterized as L. chagasi using restriction enzymes. It is already known that domestic felids can act as a reservoir of L. chagasi in endemic areas, and further studies are necessary to investigate their participation in the epidemiological chain of leishmaniasis. PMID:19740501

Dahroug, Magyda A A; Almeida, Arleana B P F; Sousa, Valéria R F; Dutra, Valéria; Turbino, Nívea C M R; Nakazato, Luciano; de Souza, Roberto L

2009-09-08

234

Activation of Leishmania spp. leishporin: evidence that dissociation of an inhibitor not only improves its lipid-binding efficiency but also endows it with the ability to form pores.  

Science.gov (United States)

We have previously shown that various species of Leishmania produce a lytic activity, which, in Leishmania amazonensis, is mediated by a pore-forming cytolysin, called leishporin. It is toxic for macrophages in vitro and optimally active at pH 5.0 to 5.5 and at 37 °C, suggesting that it might be active inside phagolysosomes. Leishporin from both L. amazonensis (a-leishporin) and Leishmania guyanensis (g-leishporin) can be activated by proteases, suggesting either a limited proteolysis of an inactive precursor or a proteolytic degradation of a non-covalently linked inhibitor. Here, we show that both a- and g-leishporin are also activated in dissociating conditions, indicating the second hypothesis as the correct one. In fact, we further demonstrated that inactive leishporin is non-covalently associated with an inhibitor, possibly more than one oligopeptide that, when removed, renders leishporin hemolytically active. This activation was shown to be the result of both the improvement of leishporin's ability to bind to phospholipids and the emergence of its pore-forming ability. In vitro results demonstrate that leishporin can be released by the parasites, as they evolve in axenic cultures, in an inactive form that can be activated. These results are compatible with our hypothesis that leishporin can be activated in the protease-rich, low pH, and dissociating environment of parasitophorous vacuoles, leading to disruption of both vacuoles and plasma membranes with the release of amastigotes. PMID:23812644

Almeida-Campos, Flávia Regina; Castro-Gomes, Thiago; Machado-Silva, Alice; de Oliveira, Jamil Silvano; Santoro, Marcelo Matos; Frézard, Frédéric; Horta, Maria Fátima

2013-06-30

235

Candida amazonensis sp. nov., an ascomycetous yeast isolated from rotting wood in the Amazonian forest.  

Science.gov (United States)

Five strains of a novel yeast species were isolated from rotting wood samples collected in an Amazonian forest site in the state of Roraima, northern Brazil. The sequences of the D1/D2 domains of the large subunit of the rRNA gene showed that this species belongs to the Scheffersomyces clade and is related to Candida coipomoensis, Candida lignicola and Candida queiroziae. The novel species Candida amazonensis sp. nov. is proposed to accommodate these isolates. The type strain of C. amazonensis sp. nov. is UFMG-HMD-26.3(T) ( = CBS 12363(T) = NRRL Y-48762(T)). PMID:21856981

Cadete, Raquel M; Melo, Monaliza A; Lopes, Mariana R; Pereira, Gilmara M D; Zilli, Jerri E; Vital, Marcos J S; Gomes, Fátima C O; Lachance, Marc-André; Rosa, Carlos A

2011-08-19

236

Candida amazonensis sp. nov., an ascomycetous yeast isolated from rotting wood in the Amazonian forest.  

UK PubMed Central (United Kingdom)

Five strains of a novel yeast species were isolated from rotting wood samples collected in an Amazonian forest site in the state of Roraima, northern Brazil. The sequences of the D1/D2 domains of the large subunit of the rRNA gene showed that this species belongs to the Scheffersomyces clade and is related to Candida coipomoensis, Candida lignicola and Candida queiroziae. The novel species Candida amazonensis sp. nov. is proposed to accommodate these isolates. The type strain of C. amazonensis sp. nov. is UFMG-HMD-26.3(T) ( = CBS 12363(T) = NRRL Y-48762(T)).

Cadete RM; Melo MA; Lopes MR; Pereira GM; Zilli JE; Vital MJ; Gomes FC; Lachance MA; Rosa CA

2012-06-01

237

RNA polymerase I promoter and splice acceptor site recognition affect gene expression in non-pathogenic Leishmania species  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Leishmania (Sauroleishmania) tarentolae has biotechnological potential for use as live vaccine against visceral leishmaniasis and as a system for the over expression of eukaryotic proteins that possess accurate post-translational modifications. For both purposes, new systems for protein expression in this non-pathogenic protozoan are necessary. The ribosomal RNA promoter proved to be a stronger transcription driver since its use yielded increased levels of recombinant pro (more) tein in organisms of both genera Trypanosoma or Leishmania. We have evaluated heterologous expression systems using vectors with two different polypyrimidine tracts in the splice acceptor site by measuring a reporter gene transcribed from L. tarentolae RNA polymerase I promoter. Our data indicate that the efficiency of chloramphenicol acetyl transferase expression changed drastically with homologous or heterologous sequences, depending on the polypyrimidine tract used in the construct and differences in size and/or distance from the AG dinucleotide. In relation to the promoter sequence the reporter expression was higher in heterologous lizard-infecting species than in the homologous L. tarentolae or in the mammalian-infecting L. (Leishmania) amazonensis.

Orlando, Tereza Cristina; Mayer, Mário Gustavo; Campbell, David A; Sturm, Nancy R; Floeter-Winter, Lucile Maria

2007-11-01

238

Ocular alterations in dogs naturally infected by Leishmania (Leishmania) chagasi/ Alterações oculares em cães infectados naturalmente por Leishmania (Leishmania) chagasi  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Estudaram-se as condições oculares, os anticorpos anti-Leishmania e os valores de proteína total no humor aquoso de cães infectados naturalmente por Leishmania (Leishmania) chagasi. Analisaram-se 50 cães, divididos em dois grupos de 25 animais. Todos os animais foram submetidos a exame oftálmico rotineiro. Os resultados mostraram que 76% dos cães infectados apresentaram sinais oculares, sendo a uveíte a alteração predominante. A média de proteína total no humo (more) r aquoso dos animais com uveíte foi maior (P Abstract in english Ocular conditions, anti-Leishmania antibodies and total protein of the aqueous humor were studied in dogs naturally infected by Leishmania (Leishmania) chagasi. Fifty dogs were analyzed and assigned into two groups of 25 animals each. All animals were submitted to routine ophthalmic exam. Results showed that 76% of the affected animals presented ocular signs, being uveitis the predominant. The mean of total protein in the aqueous humor of animals with uveitis was higher ( (more) P

Brito, F.L.C.; Alves, L.C.; Maia, F.C.L.; Santos, E.S.C.; Laus, J.L.; Meunier, I.M.J.

2006-10-01

239

Ocular alterations in dogs naturally infected by Leishmania (Leishmania) chagasi Alterações oculares em cães infectados naturalmente por Leishmania (Leishmania) chagasi  

Directory of Open Access Journals (Sweden)

Full Text Available Ocular conditions, anti-Leishmania antibodies and total protein of the aqueous humor were studied in dogs naturally infected by Leishmania (Leishmania) chagasi. Fifty dogs were analyzed and assigned into two groups of 25 animals each. All animals were submitted to routine ophthalmic exam. Results showed that 76% of the affected animals presented ocular signs, being uveitis the predominant. The mean of total protein in the aqueous humor of animals with uveitis was higher (PEstudaram-se as condições oculares, os anticorpos anti-Leishmania e os valores de proteína total no humor aquoso de cães infectados naturalmente por Leishmania (Leishmania) chagasi. Analisaram-se 50 cães, divididos em dois grupos de 25 animais. Todos os animais foram submetidos a exame oftálmico rotineiro. Os resultados mostraram que 76% dos cães infectados apresentaram sinais oculares, sendo a uveíte a alteração predominante. A média de proteína total no humor aquoso dos animais com uveíte foi maior (P<0,05), que a dos animais com outros sinais oculares ou sem qualquer sinal. Os valores de anticorpos anti-L. chagasi obtidos no plasma foram estatisticamente superiores aos encontrados no humor aquoso (P<0,05).

F.L.C. Brito; L.C. Alves; F.C.L. Maia; E.S.C. Santos; J.L. Laus; I.M.J. Meunier

2006-01-01

240

Reacción de antígenos de Leishmania (Leishmania) mexicana con sueros de pacientes con leishmaniosis cutánea de Sinaloa, México/ Reaction of Leishmania (Leishmania) mexicana antigens by sera of patients with cutaneous leishmaniasis from Sinaloa, Mexico  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish OBJETIVO: Detectar los antígenos de Leishmania (Leishmania) mexicana que reaccionan con sueros de pacientes con leishmaniosis cutánea (LC) de Sinaloa, México. MATERIAL Y MÉTODOS: Un extracto crudo de L. (L.) mexicana fue usado como antígeno para Western blots 2-D empleando sueros de cinco pacientes con LC y controles originarios de Sinaloa, México, durante el 2008. RESULTADOS: Cinco antígenos fueron detectados sólo por los sueros de los cinco pacientes estudiados; (more) estos son: 26 kDa (pI 7.8), 27 kDa (pI 8.1), 28 kDa (pI 8.6), 29 kDa (pI 8.5) y 31 kDa (pI 9.0). CONCLUSIONES: Se detectaron nuevos antígenos de L. (L.) mexicana potencialmente inmunodominantes, lo que sugiere a este parásito como el agente causal de la LC en Sinaloa. Abstract in english OBJECTIVE: To detect Leishmania mexicana antigens reacting with sera of patients with cutaneous leishmaniasis (CL). MATERIAL AND METHODS: A crude extract of L. mexicana was used as antigen for 2-D Western blot using sera from 5 patients with CL and controls from Sinaloa, Mexico during 2008. RESULTS: Five antigens were detected in the five infected patients analyzed; their molecular weights and isoelectric points were: 26 kDa (pI 7.8), 27 kDa (pI 8.1), 28 kDa (pI 8.6), 29 (more) kDa (pI 8.5) and 31 kDa (pI 9.0). CONCLUSION: New potentially immunodominant L. mexicana antigens were detected, suggesting that this parasite could be the species responsible for human infection in Sinaloa.

Salazar-Mejía, Patricia Guadalupe; Tejeda-Aguirre, Celia Rosa; López-Moreno, Héctor Samuel

2010-04-01

 
 
 
 
241

Histopathological and immunohistochemical study of the gastrointestinal tract from a dog naturally infected with Leishmania (Leishmania) chagasi: a case report Histopatologia e imunoistoquímica do trato gastrintestinal em cão naturalmente infectado com Leishmania (Leishmania) chagasi: relato de caso  

Directory of Open Access Journals (Sweden)

Full Text Available Samples of stomach, duodenum, jejunun, ileum, cecum and colon were collected for Giemsa-smears ("imprints") from one asymptomatic mongrel dog, naturally infected with Leishmania (L) chagasi. Other fragments were obtained and fixed in formalin (10% and buffered) for histopathological and immunohistochemical studies. The immunohistochemistry was carried out by a streptavidin-peroxidase technique and it allowed to detect amastigote forms of Leishmania chagasi in the different paraffin gut sections. The principal lesion observed was a discrete to moderate chronic inflammatory reaction in the mucosa and submucosa in all fragments of the gastrointestinal tract (GIT). A chronic cellular exsudate was observed in all GIT tissues and it was composed by mononuclear cells (monocytes, plasmocytes and lymphocytes). A comparison between the two techniques showed that the immunohistochemistry study is the best method to detect amastigote forms of Leishmania.Um cão assintomático e naturalmente infectado com Leishmania (L.) chagasi foi sacrificado e fragmentos do estômago, duodeno, jejuno, íleo, ceco e cólon foram coletados para confecção de esfregaços por aposição corados pelo Giemsa ("imprints"). Outros fragmentos foram obtidos e fixados em formol tamponado a 10% para estudos histopatológicos e imunoistoquímicos. Empregou-se a técnica imunoistoquímica de estreptavidina-peroxidase a qual possibilitou detecção de formas amastigotas de Leishmaniachagasi em todos os segmentos do trato gastrintestinal (TGI). A principal lesão observada foi a reação inflamatória crônica de intensidade variável, localizada principalmente na mucosa e submucosa de todos os segmentos do TGI. O exsudato celular era composto de monócitos, plasmócitos e linfócitos. O estudo imunoistoquímico mostrou a presença de amastigotas de Leishmania em todos os fragmentos do TGI. A pesquisa de parasitas não pôde ser observada de forma satisfatória pela técnica da HE. Concluiu-se que a técnica de imunoistoquímica como diagnóstico da doença no caso de envolvimento gastrintestinal é eficaz.

F.L. Silva; W.L. Tafuri; M.R. Oliveira; Wg. L. Tafuri

2002-01-01

242

Amastigota forms resembling Leishmania sp. on corneal ulceration in a dog: case report Formas amastigotas compatíveis com Leishmania sp. em ulceração corneal de cão: relato de caso  

Directory of Open Access Journals (Sweden)

Full Text Available One dog with visceral leishmaniasis is reported presenting cutaneous lesions, cachexia, and corneal ulceration. Parasitological and serological diagnoses were performed by exam of contents of the aspirative punction of the bone marrow and by immunofluorecence, respectively. Amastigota forms resembling Leishmania sp. were visualized by citology.Relata-se o caso de um cão com leishmaniose visceral apresentando lesões cutâneas, caquexia e úlcera de córnea. Realizou-se o diagnóstico parasitológico e sorológico por meio de exame do material da medula óssea e por imunofluorescência indireta, respectivamente. À citologia da úlcera corneana, visibilizaram-se formas amastigotas compatíveis com Leishmania sp.

F.L.C. Brito; L.C. Alves; F.C.L. Maia; A.R. Albuquerque; J.P.D. Ortiz; J.L. Laus

2007-01-01

243

Amastigota forms resembling Leishmania sp. on corneal ulceration in a dog: case report/ Formas amastigotas compatíveis com Leishmania sp. em ulceração corneal de cão: relato de caso  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Relata-se o caso de um cão com leishmaniose visceral apresentando lesões cutâneas, caquexia e úlcera de córnea. Realizou-se o diagnóstico parasitológico e sorológico por meio de exame do material da medula óssea e por imunofluorescência indireta, respectivamente. À citologia da úlcera corneana, visibilizaram-se formas amastigotas compatíveis com Leishmania sp. Abstract in english One dog with visceral leishmaniasis is reported presenting cutaneous lesions, cachexia, and corneal ulceration. Parasitological and serological diagnoses were performed by exam of contents of the aspirative punction of the bone marrow and by immunofluorecence, respectively. Amastigota forms resembling Leishmania sp. were visualized by citology.

Brito, F.L.C.; Alves, L.C.; Maia, F.C.L.; Albuquerque, A.R.; Ortiz, J.P.D.; Laus, J.L.

2007-02-01

244

Ocorrência de Leishmania spp. em felinos do município de Araçatuba, SP Occurrence de Leishmania spp. in domestic cats from Araçatuba, SP  

Directory of Open Access Journals (Sweden)

Full Text Available Este trabalho teve como objetivo comparar a ocorrência de Leishmania spp. em gatos por dois métodos (citológico e sorológico), bem como associar a ocorrência deste protozoário com as variáveis sexo, idade e raça. Amostras séricas de 283 felinos domésticos foram testadas pela Reação de Imunofluorescência Indireta (RIFI), e o exame parasitológico direto de linfonodos também foi realizado para a verificação da positividade para Leishmania spp. Ocorrência de 0,7% (2/283) foi observada nos felinos examinados, por meio de imprint de linfonodos e nenhum animal apresentou títulos de anticorpos para Leishmania spp. As duas fêmeas positivas eram sem raça definida, sendo uma jovem e outra adulta. Por meio dos resultados obtidos, não foi constatada diferença estatisticamente significante em relação às variáveis sexo, raça e idade nos gatos desta pesquisa (p > 0,05). Ocorrência de Leishmania spp. nos gatos deste estudo foi baixa. Devido a esta baixa incidência sugere-se que estes não assumem importância epidemiológica na área do estudo.This study had the purpose to compare the occurrence of Leishmania spp. in felines through two methods (cytological and serological), as well as to associate the occurrence of this protozoan with the sex, age and breed variables. Serum samples from 283 domestic felines were processed by means of Indirect Immunofluorescence Reaction (IIR), and the direct parasitological test for linfonodes was also carried out in order to verify positivity for Leishmania spp. Occurrence of 0.7% (2/283) was observed in the tested felines by means of linfonode imprinting and no animal showed title of antibodies for Leishmania spp. The two positive females were mongrel, a young female and an adult female feline. From the obtained results, no statistically significant difference was observed as regards the sex, breed and age variables in this research (p > 0.05). Occurrence of Leishmania spp. in the cats of this study was low. Such low incidence suggests that these hosts has no epidemiological relevance in the study area.

Katia Denise Saraiva Bresciani; Ana Claudia Marques Serrano; Lucas Vinicius Shigaki de Matos; Elisa San Martin Mouriz Savani; Sandra Regina Nicoletti D'Auria; Silvia Helena Venturoli Perri; Fabio Luiz Bonello; Willian Marinho Dourado Coelho; Carolina Godoi Aoki; Alvimar José da Costa

2010-01-01

245

Ensayos metodologicos para la investigacion de reservorios de Leishmania spp en los Andes venezolanos Methodological assay for research of reservoirs of Leishmania spp. in the Venezuelan Andes  

Directory of Open Access Journals (Sweden)

Full Text Available Se describen dos técnicas, presuntiva y confirmativa, para la investigación de mamíferos que pudieran ser reservorios de Leishmania que parasitan al hombre. Se investigan los cambios en los títulos de inmovilización y aglutinación de promastigotos de cultivo por los sueros de animales normales y expuestos una o varias veces a la inoculación intradérmica de pequeñas dosis de promastigotos vivos. Se registra una caída de los títulos de aglutinación en los sueros de hamsteres, de Holochilus venezuelae y de Didelphis marsupialis después de la inoculación con L. mexicana mexicana de Panamá y de L. gamhami de la región de los Andes venezolanos. Se discute la natureza de estos fenómenos. Se han hecho xenodiagnósticos con Lutzomyia townsendi en Holochilus venezuelae y Sigmodon hispidus infectados experimentalmente com L. mexicana mexicana, L. mexicana amazonensis, L. braziliensis y L. garnhami. Las pruebas fueron leidas mediante el examen microscópico de las gotitas de heces excretadas entre las 108 y 132 horas después de la ingesta infectante, tras colorearlas con Giemsa. Se obtuvieron resultados positivos en 23% de los experimentos usando mamíferos con lesiones localizadas, dejando a los flebótomos ingurgitarse libremente sobre animales anestesiados que poseian una hasta varias lesiones localizadas.Presumptive and confirmative techniques for searching mammals which could be reservoirs for Leishmania parasites from man are described. The changes of immobilising and agglutinating titers for promastigotes from culture by sera from normal and exposed mammals after single or repeated intradermal inoculation of promastigotes are described. A fall in titers of agglunation is observed in sera from hamsters, Holochilus venezuelae and Didelphis marsupialis after inoculation with L. mexicana mexicana from Panama and L. garnhami from the Venezuelan Andes region. The nature of this phenomenon is discussed. Xenodiagnoses were made with Lutzomyia townsendi on Holochilus venezuelae and Sigmodon hispidus experimentally infected with L. mexicana mexicana, L. mexicana amazonensis, L. braziliensis and L. garnhami. The tests were read by means of microscope examination of stained faeces excreted by sandflies between 108 to 132 hours after feeding on infected animals. Positive results were obtained in 23% of experiments using mammals with localized lesions, allowing sandflies to feed freely on anesthetized animals with one to several localized lesions.

Ana Lugo Yarbuh; J. V. Scorza

1982-01-01

246

The expression of HSP83 genes in Leishmania infantum is affected by temperature and by stage-differentiation and is regulated at the levels of mRNA stability and translation  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Exposure of Leishmania promastigotes to the temperature of their mammalian hosts results in the induction of a typical heat shock response. It has been suggested that heat shock proteins play an important role in parasite survival and differentiation. Results Here we report the studies on the expression of the heat shock protein 83 (HSP83) genes of Leishmania infantum. Confirming previous observations for other Leishmania species, we found that the L. infantum HSP83 transcripts also show a temperature-dependent accumulation that is controlled by a post-transcriptional mechanism involving sequences located in the 3'-untranslated region (3'-UTR). However, contrary to that described for L. amazonensis, the accumulation of the HSP83 transcripts in L. infantum is dependent on active protein synthesis. The translation of HSP83 transcripts is enhanced during heat shock and, as first described in L. amazonensis, we show that the 3'-UTR of the L. infantum HSP83 gene is essential for this translational control. Measurement of the steady-state levels of HSP83 transcripts along the promastigote-to-amastigote differentiation evidenced a specific profile of HSP83 RNAs: after an initial accumulation of HSP83 transcripts observed short after (2 h) incubation in the differentiation conditions, the amount of HSP83 RNA decreased to a steady-state level lower than in undifferentiated promastigotes. We show that this transient accumulation is linked to the presence of the 3'-UTR and flanking regions. Again, an 8-fold increase in translation of the HSP83 transcripts is observed short after the initiation of the axenic differentiation, but it is not sustained after 9 h. Conclusions This transient expression of HSP83 genes could be relevant for the differentiation of Leishmania, and the underlying regulatory mechanism may be part of the developmental program of this parasite.

Larreta Ruth; Soto Manuel; Quijada Luis; Folgueira Cristina; Abanades Daniel R; Alonso Carlos; Requena Jose M

2004-01-01

247

First occurrence of an autochthonous canine case of Leishmania (Leishmania) infantum chagasi in the municipality of Campinas, State of São Paulo, Brazil Ocorrência do primeiro caso autóctone canino por Leishmania (Leishmania) infantum chagasi no Município de Campinas, Estado de São Paulo, Brasil  

Directory of Open Access Journals (Sweden)

Full Text Available An autochthonous case of visceral leishmaniasis is reported in a dog (Canis familiaris) as an apparently natural infection in a non-endemic area. DNA obtained from spleen and liver samples produced the expected fragment in a Leishmania-specific rDNA-based nested-PCR assay. The PCR product, a 490 bp fragment, was sequenced and the nucleotide sequence was identical to that of Leishmania (Leishmania) infantum chagasi. These results are surprising since no autochthonous human or canine cases of visceral leishmaniasis have ever been reported in this municipality. This case suggests that natural transmission of this disease is occurring in this area.Caso autóctone de leishmaniose visceral é relatado em cão (Canis familiaris), aparentemente em área não endêmica. DNA obtido a partir de amostras do baço e fígado foram submetidos a nested-PCR baseada no rDNA específico de Leishmania. Os produtos das PCR foram sequenciados e os 490 pares de base foram idênticos a Leishmania (Leishmania) infantum chagasi. Esses resultados são surpreendentes, uma vez que, nenhum caso autóctone canino ou humano de leishmaniose visceral havia sido relatado neste município. Esse caso sugere que a transmissão natural da doença está ocorrendo nesta área.

Elisa San Martin Mouriz Savani; Douglas Presotto; Thais Roberto; Maria Cecília Gibrail de Oliveira Camargo; Sandra Regina Nicoletti D'auria; Débora Veiga Sacramento

2011-01-01

248

First occurrence of an autochthonous canine case of Leishmania (Leishmania) infantum chagasi in the municipality of Campinas, State of São Paulo, Brazil/ Ocorrência do primeiro caso autóctone canino por Leishmania (Leishmania) infantum chagasi no Município de Campinas, Estado de São Paulo, Brasil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Caso autóctone de leishmaniose visceral é relatado em cão (Canis familiaris), aparentemente em área não endêmica. DNA obtido a partir de amostras do baço e fígado foram submetidos a nested-PCR baseada no rDNA específico de Leishmania. Os produtos das PCR foram sequenciados e os 490 pares de base foram idênticos a Leishmania (Leishmania) infantum chagasi. Esses resultados são surpreendentes, uma vez que, nenhum caso autóctone canino ou humano de leishmaniose vi (more) sceral havia sido relatado neste município. Esse caso sugere que a transmissão natural da doença está ocorrendo nesta área. Abstract in english An autochthonous case of visceral leishmaniasis is reported in a dog (Canis familiaris) as an apparently natural infection in a non-endemic area. DNA obtained from spleen and liver samples produced the expected fragment in a Leishmania-specific rDNA-based nested-PCR assay. The PCR product, a 490 bp fragment, was sequenced and the nucleotide sequence was identical to that of Leishmania (Leishmania) infantum chagasi. These results are surprising since no autochthonous human (more) or canine cases of visceral leishmaniasis have ever been reported in this municipality. This case suggests that natural transmission of this disease is occurring in this area.

Savani, Elisa San Martin Mouriz; Presotto, Douglas; Roberto, Thais; Camargo, Maria Cecília Gibrail de Oliveira; D'auria, Sandra Regina Nicoletti; Sacramento, Débora Veiga

2011-08-01

249

Leishmania spp. parasite isolation through inoculation of patient biopsy macerates in interferon gamma knockout mice Leishmania spp.: isolamento de parasitos pela inoculação de macerados de biopsias de pacientes em camundongos deficientes em interferon gama  

Directory of Open Access Journals (Sweden)

Full Text Available Isolation of Leishmania parasite and species identification are important for confirmation and to help define the epidemiology of the leishmaniasis. Mice are often used to isolate pathogens, but the most common mouse strains are resistant to infection with parasites from the Leishmania (Viannia) subgenus. In this study we tested the inoculation of interferon gamma knockout (IFN? KO) mice with biopsy macerates from Leishmania-infected patients to increase the possibility of isolating parasites. Biopsies from twenty five patients with clinical signs of leishmaniasis were taken and tested for the presence of parasites. Immunohistochemical assay (IHC) and conventional histopathology detected the parasite in 88% and 83% of the patients, respectively. Leishmania sp. were isolated in biopsy macerates from 52% of the patients by culture in Grace's insect medium, but 13% of isolates were lost due to contamination. Inoculation of macerates in IFN? KO mice provides isolation of parasites in 31.8% of the biopsies. Most isolates belong to L. (Viannia) subgenus, as confirmed by PCR, except one that belongs to L. (Leishmania) subgenus. Our preliminary results support the use of IFN? KO mice to improve the possibility to isolate New World Leishmania species.O isolamento e a identificação da espécie de parasito do gênero Leishmania são importantes para a confirmação e auxiliam na epidemiologia da leishmaniose. Os camundongos são freqüentemente utilizados para isolar patógenos, porém, as linhagens mais comuns de camundongos são resistentes à infecção por parasitos do subgênero Leishmania (Viannia). Neste estudo, avaliamos a inoculação de macerados de biópsias de pacientes infectados em camundongos deficientes do gene do interferon gama (IFN? KO) como um método para aumentar a possibilidade de isolar Leishmania spp. Biópsias de 25 pacientes infectados com Leishmania sp. foram avaliadas para a presença de parasitos pelos métodos de imunohistoquímica (IHC) e histopatologia convencional. Os parasitos foram observados, respectivamente, em 88% e 83% das biópsias. Leishmania sp. foi isolada de macerados de biópsia de 52% dos pacientes infectados, quando cultivados em meio Grace, porém, 13% destes isolados foram perdidos devido a contaminações. Inoculação dos macerados em camundongos IFN? KO proporcionou o isolamento de parasitos oriundos de 31,8% dos pacientes. A maioria dos isolados pertence ao subgênero L. (Viannia), exceto um que pertence ao subgênero L. (Leishmania), como confirmado pela reação da polimerase em cadeia. Nossos resultados preliminares sugerem que o uso de camundongos IFN? KO pode ser útil para aumentar a possibilidade de isolamento de leishmânias encontradas nas Américas.

Milton Adriano Pelli de Oliveira; Alause da Silva Pires; Rosidete Pereira de Bastos; Glória Maria Collet de Araujo Lima; Sebastião Alves Pinto; Ledice Inácia de Araujo Pereira; Ana Joaquina Cohen Serique Pereira; Ises de Almeida Abrahamsohn; Miriam Leandro Dorta; Fátima Ribeiro-Dias

2010-01-01

250

Infecção natural de Equus asinus por Leishmania braziliensis braziliensis - Bahia, Brasil/ Natural infection of Equus asinus by Leishmania braziliensis braziliensis - Bahia, Brazil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Em Corte de Pedra, Valença, Bahia, foi encontrado um jumento (Equus asinus), com infecção natural por Leishmania braziliensis braziliensis. O parasito foi isolado de uma lesão localizada na cicatriz da castração e identificado através de anticorpos monoclonais. Abstract in english In Corte de Pedra, Valença, state of Bahia, a donkey, Equus asinus, was found naturally infected with Leishmania braziliensis braziliensis. The parasite was isolated from a lesion located on a castration scar, and identified by means of monoclonal antibodies.

Vexenat, Julio A.; Barretto, Air C.; Rosa, Ana de Cassia O.; Sales, Christiane C.; Magalhães, Albino V.

1986-06-01

251

Comparison of the Effects of Leishmania major or Leishmania donovani Infection on Macrophage Gene Expression? †  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The intracellular parasite Leishmania causes a wide spectrum of human disease, ranging from self-resolving cutaneous lesions to fatal visceral disease, depending on the species of Leishmania involved. The mechanisms by which different Leishmania species cause different pathologies are largely unknow...

Gregory, David J.; Sladek, Robert; Olivier, Martin; Matlashewski, Greg

252

Expression of biopterin transporter (BT1) protein in Leishmania.  

UK PubMed Central (United Kingdom)

The present work focuses on the growth phase regulated expression of biopterin transporter gene (BT1) from the LD1 locus on chromosome 35 of Leishmania donovani. Antiserum against recombinant BT1 detected a polypeptide of 45 kDa of equal intensity at lag, log and stationary phases of promastigote growth, both in L. donovani strain LSB-7.1 (MHOM/BL/67/ITMAP263), and strain LSB-146.1 (HOM/IR/95/X81), a natural isolate from Isfehan, Iran that caused cutaneous leishmaniasis. However, in both these strains an additional polypeptide of higher molecular mass (50 kDa) was also observed during lag phase only. In addition, polypeptides of 40, 20, 18 and 16 kDa were seen only during the lag and log phases of both strains. Analysis of L. donovani single, double and triple (null) BT1 knockout mutants confirmed that the 45-kDa polypeptide was the BT1 gene product, as it was absent in the null mutant. These results indicate that 45-kDa BT1 protein in Leishmania is consistently and constitutively expressed in all the growth stages of the parasite.

Dole VS; Myler PJ; Stuart KD; Madhubala R

2002-02-01

253

High content analysis of primary macrophages hosting proliferating Leishmania amastigotes: application to anti-leishmanial drug discovery.  

UK PubMed Central (United Kingdom)

BACKGROUND/OBJECTIVES: Human leishmaniases are parasitic diseases causing severe morbidity and mortality. No vaccine is available and numerous factors limit the use of current therapies. There is thus an urgent need for innovative initiatives to identify new chemotypes displaying selective activity against intracellular Leishmania amastigotes that develop and proliferate inside macrophages, thereby causing the pathology of leishmaniasis. METHODOLOGY/PRINCIPAL FINDINGS: We have developed a biologically sound High Content Analysis assay, based on the use of homogeneous populations of primary mouse macrophages hosting Leishmania amazonensis amastigotes. In contrast to classical promastigote-based screens, our assay more closely mimics the environment where intracellular amastigotes are growing within acidic parasitophorous vacuoles of their host cells. This multi-parametric assay provides quantitative data that accurately monitors the parasitic load of amastigotes-hosting macrophage cultures for the discovery of leishmanicidal compounds, but also their potential toxic effect on host macrophages. We validated our approach by using a small set of compounds of leishmanicidal drugs and recently published chemical entities. Based on their intramacrophagic leishmanicidal activity and their toxicity against host cells, compounds were classified as irrelevant or relevant for entering the next step in the drug discovery pipeline. CONCLUSIONS/SIGNIFICANCE: Our assay represents a new screening platform that overcomes several limitations in anti-leishmanial drug discovery. First, the ability to detect toxicity on primary macrophages allows for discovery of compounds able to cross the membranes of macrophage, vacuole and amastigote, thereby accelerating the hit to lead development process for compounds selectively targeting intracellular parasites. Second, our assay allows discovery of anti-leishmanials that interfere with biological functions of the macrophage required for parasite development and growth, such as organelle trafficking/acidification or production of microbicidal effectors. These data thus validate a novel phenotypic screening assay using virulent Leishmania amastigotes growing inside primary macrophage to identify new chemical entities with bona fide drug potential.

Aulner N; Danckaert A; Rouault-Hardoin E; Desrivot J; Helynck O; Commere PH; Munier-Lehmann H; Späth GF; Shorte SL; Milon G; Prina E

2013-01-01

254

Evolution and species discrimination according to the Leishmania heat-shock protein 20 gene.  

UK PubMed Central (United Kingdom)

The Leishmania genus comprises up to 35 species, of which 20 are responsible for human disease. However, the taxonomic status for many of them is under discussion. The small Heat Shock Proteins (sHSPs) are physiologically relevant, protecting cellular proteins from aggregation and maintaining cellular viability under intensive stress conditions. In Leishmania, a protein of this class was previously described, the 20-kDa heat-shock protein (HSP20), which is encoded by a single gene. In the present study, we used this target, alone or in combination with hsp70 gene, to investigate the phylogenetic relationships among Leishmania species. Using a pair of degenerate primers it was possible amplifying a 370bp fragment of the hsp20 coding region in 39 strains of very different geographic origins, representing in total 16 Leishmania species (14 if L. chagasi and L. archibaldi are considered synonymous names of L. infantum and L. donovani, respectively). Nucleotide sequences were readily obtained by direct sequencing of the amplification products. Both phylogenetic trees and networks based on either hsp20 sequences or combined datasets of hsp20 and hsp70 sequences were constructed. These phylogenic analyses supported the division of the Leishmania genus into nine species: L. (L.) donovani, L. (L.) major, L. (L.) tropica, L. (L.) aethiopica, L. (L.) mexicana, L. (V.) lainsoni, L. (V.) naiffi, L. (V.) guyanensis and L. (V.) braziliensis. Additionally, by network analysis, the subspecies L. (L.) donovani infantum and L. (V.) braziliensis peruviana were recognized within the L. (L.) donovani and L. (V.) braziliensis species, respectively. Therefore, hsp20 gene was found to be a suitable molecular marker for Leishmania typing and classification purposes. In addition, this study represents a solid contribution to the objective of establishing a more reliable taxonomy for the genus Leishmania.

Fraga J; Montalvo AM; Van der Auwera G; Maes I; Dujardin JC; Requena JM

2013-08-01

255

An insight into the Leishmania RNA virus  

Directory of Open Access Journals (Sweden)

Full Text Available Leishmania RNA virus is an ancient virus that has coevolved with its protozoan host. The purpose of this article is to convey current understanding of Leishmania RNA virus as it has emerged over the past decade. The potential of the virus to play a role in modulating parasite virulence is also discussed.

Gupta V; Deep A

2007-01-01

256

First molecular-based detection of mucocutaneous leishmaniasis caused by Leishmania major in Iran.  

Science.gov (United States)

Mucocutaneous leishmaniasis, which mostly occurs in the New World, is mainly associated with Leishmania braziliensis and to a lesser degree L. panamensis and L. amazonensis infections. Primary mucosal leishmaniasis is very rare in Iran in spite of high prevalence of cutaneous and visceral leishmanisis. A nine-year-old boy had cutaneous leishmaniaisis for five years involving the left side of his face; he then developed swelling and ulceration of the lip and left side buccal mucosa five months before hospital admission. He had severe swelling of the lower lip and there was ulceration and bleeding of the buccal mucosa. Direct smear revealed leishman bodies and nested PCR confirmed the presence of kinetoplast DNA of L. major in the oral mucosal specimen. The patient received amphotericin B deoxycholate 1 mg/kg/day for one month. The lip and face inflammatory reaction disappeared to nearly normal after one month of therapy. The patient was discharged with ketoconazole (5mg/kg/day) for six weeks. To our knowledge, this is the first report of mucocutaneous leishmaniasis caused by L. major in Iran. PMID:23669431

Alborzi, Abdolvahab; Pouladfar, Gholam R; Ghadimi Moghadam, Abdolkarim; Attar, Armin; Drakhshan, Nima; Khosravi Maharlooei, Mohsen; Kalantari, Mohsen

2013-05-13

257

First molecular-based detection of mucocutaneous leishmaniasis caused by Leishmania major in Iran.  

UK PubMed Central (United Kingdom)

Mucocutaneous leishmaniasis, which mostly occurs in the New World, is mainly associated with Leishmania braziliensis and to a lesser degree L. panamensis and L. amazonensis infections. Primary mucosal leishmaniasis is very rare in Iran in spite of high prevalence of cutaneous and visceral leishmanisis. A nine-year-old boy had cutaneous leishmaniaisis for five years involving the left side of his face; he then developed swelling and ulceration of the lip and left side buccal mucosa five months before hospital admission. He had severe swelling of the lower lip and there was ulceration and bleeding of the buccal mucosa. Direct smear revealed leishman bodies and nested PCR confirmed the presence of kinetoplast DNA of L. major in the oral mucosal specimen. The patient received amphotericin B deoxycholate 1 mg/kg/day for one month. The lip and face inflammatory reaction disappeared to nearly normal after one month of therapy. The patient was discharged with ketoconazole (5mg/kg/day) for six weeks. To our knowledge, this is the first report of mucocutaneous leishmaniasis caused by L. major in Iran.

Alborzi A; Pouladfar GR; Ghadimi Moghadam A; Attar A; Drakhshan N; Khosravi Maharlooei M; Kalantari M

2013-05-01

258

Visceral leishmaniasis caused by Leishmania (Viannia) braziliensis in a patient infected with human immunodeficiency virus Leishmaniose visceral causada por Leishmania (Viannia) braziliensis em paciente infectado com HIV  

Directory of Open Access Journals (Sweden)

Full Text Available The current article reports the case of a 19-month-old-girl, from the state of Minas Gerais, Brazil, with visceral leishmaniasis, by Leishmania (Viannia) braziliensis, and Human Immunodeficiency Virus (HIV) co-infection. The child's mother and father, aged 22 and 27 years old, respectively, were both HIV positive. The child was admitted to the General Pediatric Center, in Belo Horizonte, presenting high fever, fatigue, weight loss and enlargement of liver and spleen. Indirect immunofluorescent test revealed a titer of 1:320 for Leishmania. Such result was confirmed by the presence of amastigotes in bone marrow aspirate samples and culture of promastigote forms. Parasites were identified as being Leishmania (Viannia) braziliensis through PCR, using a L. braziliensis complex primer and a generic primer, followed by hibridization. Specific leishmaniasis therapy (GlucantimeÒ antimonial) was intravenously administered.No presente artigo os autores relatam caso de uma criança de 1 ano e 07 meses proveniente do estado de Minas Gerais com leishmaniose visceral causada por Leishmania (Viannia) braziliensis e co-infecção HIV. A mãe e o pai da criança de 22 e 27 anos de idade respectivamente também HIV positivo. A criança foi internada no Centro Geral de Pediatria em Belo Horizonte com febre alta, fadiga, perda de peso e aumento de fígado e baço. Foi realizado teste de imunofluorescência indireta para Leishmania e detectado título de 1:320. Este resultado foi confirmado com o encontro de amastigotas em aspirado de medula óssea e o crescimento de promastigotas em meios de cultura. Os parasitos foram identificados como Leishmania (Viannia) braziliensis utilizando PCR com primer específico para o complexo L. braziliensis, e primer genérico seguido de hibridização. Terapia específica para leishmaniose (antimonial de Glucantime) foi administrado por via intravenosa.

Eduardo Sérgio da SILVA; Raquel Silva PACHECO; Célia Maria Ferreira GONTIJO; Inácio Roberto CARVALHO; Reginaldo Peçanha BRAZIL

2002-01-01

259

Estudo, ao microscópio óptico e eletrônico, do rim de caes natural e experimentalmente infectados com Leishmania (Leishmania) chagasi Optical and electron microscopical studies of canine kidney naturally and experimentally infected with Leishmania (Leishmania) chagasi  

Directory of Open Access Journals (Sweden)

Full Text Available Os autores estudam os rins de 4 cães infectados com Leishmania (Leishmania) chagasi. Dois animais (um macho e uma fêmea) naturalmente infectados foram sacrificados 18 meses após sua permanência no laboratório. Dois machos foram inoculados por via endovenosa, com lxlO6 promastigotas da cepa MHO/BR/70/BH46 e sacrificados após 18 meses e 2 anos, respectivamente. Em todos os animais os rins estavam lesados. As alterações encontradas foram: (1) glomerulonefrite mesangioproliferativa focal ou difusa, com pronunciada hipertrofia e hiperplasia das células mesangiais e com alargamento da matriz; (2) espessamento da membrana basal com depósitos eletrondensos; (3) nefrite intersticial intertubular crônica com exsudação plasmocitária intensa. (4) degeneração albuminosa dos túbulos renais. Baseados nos achados os autores discutem os prováveis mecanismos patogenéticos.Two naturally infected dogs (male and fema lei from Teófilo Otoni (MG Brazili were maintained for 18 months in our laboratory. Two other dogs, two months old males were infected with 1 x 10(6) promastigotes of MHO BR 70 BH46 Leishinania (Leishmanial chagasi strain, endo venous route, and autopsied after 10 months and two years. The main findings concerning the kidney were: (1) focal or diffuse mesangial glomerulo nephritis with proliferative and enlargement of mesangial cells; (2) increase in thickness of basement membrane with electron dense deposits: (3) chronic interstitial nephritis with intense exudation of plasmocytes: (4) cloud swelling of renal tubules. The authors discuss the probable pathogenetic mechanisms.

Washington Luiz Tafuri; Marilena Suzan Marques Michalick; Magno Dias; Odair Genaro; Virginia Hora Rios Leite; Alfredo José Afonso Barbosa; Eduardo Alves Bambirra; Carlos Alberto Da Costa; Maria Norma Melo; Wilson Mayrink

1989-01-01

260

Ocorrência de Leishmania spp. em felinos do município de Araçatuba, SP/ Occurrence de Leishmania spp. in domestic cats from Araçatuba, SP  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Este trabalho teve como objetivo comparar a ocorrência de Leishmania spp. em gatos por dois métodos (citológico e sorológico), bem como associar a ocorrência deste protozoário com as variáveis sexo, idade e raça. Amostras séricas de 283 felinos domésticos foram testadas pela Reação de Imunofluorescência Indireta (RIFI), e o exame parasitológico direto de linfonodos também foi realizado para a verificação da positividade para Leishmania spp. Ocorrência de (more) 0,7% (2/283) foi observada nos felinos examinados, por meio de imprint de linfonodos e nenhum animal apresentou títulos de anticorpos para Leishmania spp. As duas fêmeas positivas eram sem raça definida, sendo uma jovem e outra adulta. Por meio dos resultados obtidos, não foi constatada diferença estatisticamente significante em relação às variáveis sexo, raça e idade nos gatos desta pesquisa (p > 0,05). Ocorrência de Leishmania spp. nos gatos deste estudo foi baixa. Devido a esta baixa incidência sugere-se que estes não assumem importância epidemiológica na área do estudo. Abstract in english This study had the purpose to compare the occurrence of Leishmania spp. in felines through two methods (cytological and serological), as well as to associate the occurrence of this protozoan with the sex, age and breed variables. Serum samples from 283 domestic felines were processed by means of Indirect Immunofluorescence Reaction (IIR), and the direct parasitological test for linfonodes was also carried out in order to verify positivity for Leishmania spp. Occurrence of (more) 0.7% (2/283) was observed in the tested felines by means of linfonode imprinting and no animal showed title of antibodies for Leishmania spp. The two positive females were mongrel, a young female and an adult female feline. From the obtained results, no statistically significant difference was observed as regards the sex, breed and age variables in this research (p > 0.05). Occurrence of Leishmania spp. in the cats of this study was low. Such low incidence suggests that these hosts has no epidemiological relevance in the study area.

Bresciani, Katia Denise Saraiva; Serrano, Ana Claudia Marques; Matos, Lucas Vinicius Shigaki de; Savani, Elisa San Martin Mouriz; D'Auria, Sandra Regina Nicoletti; Perri, Silvia Helena Venturoli; Bonello, Fabio Luiz; Coelho, Willian Marinho Dourado; Aoki, Carolina Godoi; Costa, Alvimar José da

2010-06-01

 
 
 
 
261

Fatty acid and hydrocarbon composition in tropical marine Shewanella amazonensis strain SB2B(T).  

Science.gov (United States)

Shewanella amazonensis strain SB2B(T) is an isolate from shallow-water marine sediments derived from the Amazon River delta. This bacterium contained a long-chain polyunsaturated hydrocarbon, all-cis -3,6,9,12,16,19,22,25,28 hentriacontanonaene (C31:9), constituting 1-2% of the total fatty acid methyl ester and hydrocarbon fraction, which was produced dependently of decreased growth temperature. Analysis of its cellular fatty acid composition demonstrated that isopentadecanoic acid was the major fatty acid component and that all the main monounsaturated fatty acids had straight chains with a cis configuration. However, monoenoic cyclopropyl fatty acids, which were previously reported to be present in this bacterium, were not detected by mass spectrometric analysis. The growth temperature affected the content of ?9-cis -hexadecenoic [16:1(?9c)], palmitic, and heptadecanoic acids. These results suggest that C31:9, as well as 16:1(?9c) might be involved in adaptation to low temperature in S. amazonensis strain SB2B(T) . Our result suggests that polyunsaturated fatty acid synthase protein complex may be involved in synthesis of C31:9 but not in production of eicosapentaenoic acid. PMID:21656813

Motoigi, Taro; Okuyama, Hidetoshi

2011-03-24

262

Fatty acid and hydrocarbon composition in tropical marine Shewanella amazonensis strain SB2B(T).  

UK PubMed Central (United Kingdom)

Shewanella amazonensis strain SB2B(T) is an isolate from shallow-water marine sediments derived from the Amazon River delta. This bacterium contained a long-chain polyunsaturated hydrocarbon, all-cis -3,6,9,12,16,19,22,25,28 hentriacontanonaene (C31:9), constituting 1-2% of the total fatty acid methyl ester and hydrocarbon fraction, which was produced dependently of decreased growth temperature. Analysis of its cellular fatty acid composition demonstrated that isopentadecanoic acid was the major fatty acid component and that all the main monounsaturated fatty acids had straight chains with a cis configuration. However, monoenoic cyclopropyl fatty acids, which were previously reported to be present in this bacterium, were not detected by mass spectrometric analysis. The growth temperature affected the content of ?9-cis -hexadecenoic [16:1(?9c)], palmitic, and heptadecanoic acids. These results suggest that C31:9, as well as 16:1(?9c) might be involved in adaptation to low temperature in S. amazonensis strain SB2B(T) . Our result suggests that polyunsaturated fatty acid synthase protein complex may be involved in synthesis of C31:9 but not in production of eicosapentaenoic acid.

Motoigi T; Okuyama H

2011-10-01

263

Evidence for a neotropical origin of Leishmania  

Directory of Open Access Journals (Sweden)

Full Text Available Contradictory biogeographic hypotheses for either a Neotropical or a Palaearctic origin of the genus Leishmania have been proposed. Hypotheses constructed on the basis of biogeographic data must be tested against an independent dataset and cannot be supported by biogeographic data alone. In the absence of a fossil record for the Leishmania these two hypotheses were tested against a combined dataset of sequences from the DNA polymerase A catalytic subunit and the RNA polymerase II largest subunit. The phylogeny obtained provided considerable support for a Neotropical origin of the genus Leishmania and leads us to reject the hypothesis for a Palaearctic origin.

HA Noyes; DA Morrison; ML Chance; JT Ellis

2000-01-01

264

Evidence for a neotropical origin of Leishmania  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Contradictory biogeographic hypotheses for either a Neotropical or a Palaearctic origin of the genus Leishmania have been proposed. Hypotheses constructed on the basis of biogeographic data must be tested against an independent dataset and cannot be supported by biogeographic data alone. In the absence of a fossil record for the Leishmania these two hypotheses were tested against a combined dataset of sequences from the DNA polymerase A catalytic subunit and the RNA polym (more) erase II largest subunit. The phylogeny obtained provided considerable support for a Neotropical origin of the genus Leishmania and leads us to reject the hypothesis for a Palaearctic origin.

Noyes, HA; Morrison, DA; Chance, ML; Ellis, JT

2000-08-01

265

Genetic causes involved in Leishmania Chagasi infection innortheastern: Brazil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Uma amostra de 502 indivíduos, pertencentes a 94 famílias de Jacobina (Estado da Bahia, Brasil), foi estudada com a finalidade de averiguar os mecanismos causais implicados na infecção por Leishmania chagasi (o agente causal do calazar, no hemisfério americano), medida pela reação intradérmica ao antígeno derivado desse parasita, utilizando análises de segregação complexa. Os resultados evidenciaram um mecanismo genético principal atuando sobre a infecção, (more) com o gene recessivo responsável pela susceptibilidade tendo uma freqüência de aproximadamente 0,54. A hipótese da existência de um pequeno componente multifatorial (H = 0,29), agindo em conjunto com o gene principal recessivo (q = 0,37), não pode ser descartada. Abstract in english A sample of 502 individuals from 94 families from Jacobina, State of Bahia, Brazil, was investigated to determine the causal mechanisms involved in Leishmania chagasi (the causal agent of visceral leishmaniasis in the American hemisphere) infection, as measured by the intradermic reaction to antigens derived from this parasite, using complex segregation analyses. The results showed evidence of a major genetic mechanism acting on infection, with a frequency of a recessive (more) (or additive) susceptibility gene (q) of approximately 0.45. A small multifactorial component (H = 0.29) acting in conjunction with a major recessive gene (q = 0.37) is not ruled out as a concomitant causative factor.

Feitosa, Mary Furlan; Azevêdo, Eliane; Lima, Ângela Maria; Krieger, Henrique

1999-03-01

266

Genetic causes involved in Leishmania Chagasi infection innortheastern: Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available A sample of 502 individuals from 94 families from Jacobina, State of Bahia, Brazil, was investigated to determine the causal mechanisms involved in Leishmania chagasi (the causal agent of visceral leishmaniasis in the American hemisphere) infection, as measured by the intradermic reaction to antigens derived from this parasite, using complex segregation analyses. The results showed evidence of a major genetic mechanism acting on infection, with a frequency of a recessive (or additive) susceptibility gene (q) of approximately 0.45. A small multifactorial component (H = 0.29) acting in conjunction with a major recessive gene (q = 0.37) is not ruled out as a concomitant causative factor.Uma amostra de 502 indivíduos, pertencentes a 94 famílias de Jacobina (Estado da Bahia, Brasil), foi estudada com a finalidade de averiguar os mecanismos causais implicados na infecção por Leishmania chagasi (o agente causal do calazar, no hemisfério americano), medida pela reação intradérmica ao antígeno derivado desse parasita, utilizando análises de segregação complexa. Os resultados evidenciaram um mecanismo genético principal atuando sobre a infecção, com o gene recessivo responsável pela susceptibilidade tendo uma freqüência de aproximadamente 0,54. A hipótese da existência de um pequeno componente multifatorial (H = 0,29), agindo em conjunto com o gene principal recessivo (q = 0,37), não pode ser descartada.

Mary Furlan Feitosa; Eliane Azevêdo; Ângela Maria Lima; Henrique Krieger

1999-01-01

267

Characterization of a Monoclonal Antibody Specific for the Parasite Surface Antigen-2 of Leishmania major  

Directory of Open Access Journals (Sweden)

Full Text Available The Leishmania major Parasite surface Antigen-2 (PSA-2) is a family of glycoinositol phospholipids anchored glycoprotoins expressed in both promastigotes and amastigotes. Promastigote PSA-2 comprises three polypeptides with approximate molecular weight of 96, 80 and 50 kDa. Amastigote express a distinct but closely PSA-2 polypeptide with molecular weight of 50 kDa. In this study fusion of SP2/0 myeloma cells with immunized mice spleenocytes infected with promastigotes of L. major intraperitoneally resulted to a clone of hybridoma producing a specific antibody that only reacts with L. major parasite surface antigen (PSA-2). This mAb showed no crossreactivity with either other Leishmania species including L. tropica, L. donovani and L. infantum or recombinant gp63. Western blot analysis of culture supernatant revealed multiple bands with molecular weight of 50, 58, 80 and 96 kDa only in L. major.

"AR Khabiri; F Bagheri; SR Naddaf; M Assmar; A Hosseini Taghavi"

2004-01-01

268

Chronic interstitial pneumonitis in dogs naturally infected with Leishmania (Leishmania) chagasi: a histopathological and morphometric study Pneumonia intersticial crônica em cães naturalmente infectados com Leishmania (Leishmania) chagasi: estudo histopatológico e morfométrico  

Directory of Open Access Journals (Sweden)

Full Text Available Eighteen mongrel dogs of unknown age and naturally infected with Leishmania (Leishmania) chagasi, were obtained from the City Hall of Belo Horizonte, Brazil. Four dogs were used as control. Lung samples were obtained and immediately fixed in formalin. The histopathological picture of all lung tissue sections was a chronic and diffuse interstitial pneumonitis. The thickened inter-alveolar septa were characterized by the cellular exudate (mostly macrophages, lymphocytes and plasmocytes) associated with collagen deposition. Morphometric analysis showed greater septal thickness in the infected animals than in controls. In fact, the morphometric study of collagen stained with ammoniac silver confirmed a larger deposition of collagen in the infected animals. The parasitologic method was carried out during the study of the lesions on the slides. However, we did not observe any correlation between the histopathologic and morphometric data and the clinical status of the animals. We conclude that the pulmonary lesions observed in all naturally infected dogs were correlated with the disease and that the morphometric method used was satisfactory for the analysis of septal thickness and of increased collagen deposition, confirming the presence of fibrosis.Neste estudo, foram utilizados dezoito cães naturalmente infectados com Leishmania (Leishmania) chagasi, sem raça e idade definidos, cedidos pelo Centro de Contole de Zoonoses da Cidade de Belo Horizonte. Quatro cães foram utilizados como controle. Durante a necropsia, amostras do pulmão foram coletadas, e imediatamente fixadas em formalina. A histopatologia mostrou principalmente uma pneumonite intersticial crônica, produtiva, difusa e intensa. Os septos inter-alveolares espessados, eram constituídos principalmente por um infiltrado de células inflamatórias, em sua maioria, macrófagos, linfócitos e plasmócitos, além de fibroblastos e fibras colágenas. A análise morfométrica do espessamento septal mostrou diferença significativa entre animais infectados e controle. De fato, a análise morfométrica do colágeno, corado pela prata, confirmou um aumento na deposição de colágeno em todos os animais infectados. O exame parasitológico foi ralizado durante a análise histopatológica, em todos os casos estudados. Contudo neste trabalho, não observamos qualquer correlação entre os achados histopatológicos e morfométricos quando relacionados aos cães em diferentes formas clínicas. Concluímos que as lesões, encontradas nos cães naturalmente infectados, tem correlação com a doença, e que o método de análise morfométrica utilizado apresentou resultados satisfatórios quanto à análise do espessamento septal e ao aumento da deposição de colágeno, confirmando a fibrose.

Ricardo Gonçalves; Washington Luiz Tafuri; Maria Norma de Melo; Pedro Raso; Wagner Luiz Tafuri

2003-01-01

269

Susceptibility of laboratory-reared female Lutzomyia longipalpis (Lutz & Neiva, 1912) to infection by different species and strains of Leishmania Ross, 1903  

Directory of Open Access Journals (Sweden)

Full Text Available A study was undertaken to compare the susceptibility of laboratory-reared female Lutzomyia longipalpis to infection by different species or strains of New World Leishmania. The sand flies proved to be highly susceptible to infection by a strain of Le. guyanensis, with flagellates developing in all (18/18) of the specimens examined. A lower infection rate of 37 per cents (10/27) was recorded in flies exposed to infection by a strain of Le. amazonensis. Flagellates developed in 13 per cents (6/46) of the sand flies that glood fed on dogs in the earlly stage of experimental infection with an old laboratory strain of Le. chagasi. In contrast, promastigotes did not develop in sand flies that blood fed on dogs with naturally acquired Le. chagasi. The naturally infected dogas were in an advanced stage of disease. Flagellates developed in 9// (3/32) of the sand flies that blood fed on lesions of hamsters infected with a strain of Le. braziliensis and in 9 per cents (3/34) of those that fed on hamsters with lesions due to a parasite fo the mexicana complex (strain MHOM/BR/73/BH121). Sand flies did not develop flagellate infections after blood feeding on hamsters bearing lesions induced by strain MHOM/BR/71/BR49. Factors influencing the susceptibility of Lu. longipalpis to infection by New World species of Leishmania are discussed.

Ana Lúcia F. F. da Silva; Paul Williams; Maria Norma Melo; Wilson Mayrink

1990-01-01

270

In Vitro and In Vivo Activity of an Organic Tellurium Compound on Leishmania (Leishmania) chagasi  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Tellurium compounds have shown several biological properties and recently the leishmanicidal effect of one organotellurane was demonstrated. These findings led us to test the effect of the organotellurium compound RF07 on Leishmania (Leishmania) chagasi, the agent of visceral leishmaniasis in Latin ...

Pimentel, Isabella Aparecida Salerno; Paladi, Carolina de Siqueira; Katz, Simone; Júdice, Wagner Alves de Souza

271

Leishmania major, the predominant Leishmania species responsible for cutaneous leishmaniasis in Mali.  

Science.gov (United States)

Leishmania major is the only species of Leishmania known to cause cutaneous leishmanisis (CL) in Mali. We amplified Leishmania DNA stored on archived Giemsa-stained dermal scraping slides obtained from self-referral patients with clinically suspected CL seen in the Center National d'Appui A La Lutte Contre La Maladie (CNAM) in Bamako, Mali, to determine if any other Leishmania species were responsible for CL in Mali and evaluate its geographic distribution. Polymerase chain reaction (PCR) amplification was performed using a Leishmania species-specific primer pair that can amplify DNA from L. major, L. tropica, L. infantum, and L. donovani parasites, possible causative agents of CL in Mali. L. major was the only species detected in 41 microscopically confirmed cases of CL from five regions of Mali (Kayes, Koulikoro, Ségou, Mopti, and Tombouctou). These results implicate L. major as the predominant, possibly exclusive species responsible for CL in Mali. PMID:23324218

Paz, Carlos; Samake, Sibiry; Anderson, Jennifer M; Faye, Ousmane; Traore, Pierre; Tall, Koureishi; Cisse, Moumine; Keita, Somita; Valenzuela, Jesus G; Doumbia, Seydou

2013-01-16

272

PLGA nanoparticles loaded with KMP-11 stimulate innate immunity and induce the killing of Leishmania.  

UK PubMed Central (United Kingdom)

UNLABELLED: We recently demonstrated that immunization with polyester poly(lactide-co-glycolide acid) (PLGA) nanoparticles loaded with the 11-kDa Leishmania vaccine candidate kinetoplastid membrane protein 11 (KMP-11) significantly reduced parasite load in vivo. Presently, we explored the ability of the recombinant PLGA nanoparticles to stimulate innate responses in macrophages and the outcome of infection with Leishmania braziliensis in vitro. Incubation of macrophages with KMP-11-loaded PLGA nanoparticles significantly decreased parasite load. In parallel, we observed the augmented production of nitric oxide, superoxide, TNF-? and IL-6. An increased release of CCL2/MCP-1 and CXCL1/KC was also observed, resulting in macrophage and neutrophil recruitment in vitro. Lastly, the incubation of macrophages with KMP-11-loaded PLGA nanoparticles triggered the activation of caspase-1 and the secretion of IL-1? and IL-18, suggesting inflammasome participation. Inhibition of caspase-1 significantly increased the parasite load. We conclude that KMP-11-loaded PLGA nanoparticles promote the killing of intracellular Leishmania parasites through the induction of potent innate responses. FROM THE CLINICAL EDITOR: In this novel study, KMP-11-loaded PLGA nanoparticles are demonstrated to promote the killing of intracellular Leishmania parasites through enhanced innate immune responses by multiple mechanisms. Future clinical applications would have a major effect on our efforts to address parasitic infections.

Santos DM; Carneiro MW; de Moura TR; Soto M; Luz NF; Prates DB; Irache JM; Brodskyn C; Barral A; Barral-Netto M; Espuelas S; Borges VM; de Oliveira CI

2013-10-01

273

American cutaneous leishmaniasis caused by Leishmania (Viannia) braziliensis resistant to meglumine antimoniate, but with good response to pentamidine: a case report/ Leishmaniose cutânea americana causada pela Leishmania (Viannia) braziliensis resistente ao antimoniato de meglumina e com boa resposta terapêutica à pentamidina: relato de um caso  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Relatamos um caso de um militar brasileiro com leishmaniose cutânea, cuja lesão reativou após dois tratamentos sistêmicos com antimoniato de meglumina. Foi tratado com anfotericina B, mas precisou interromper por intolerância à medicação. Após isolamento de Leishmania sp, seis infiltrações intralesionais de antimoniato de meglumina foram realizadas, sem resposta. Promastigotas de Leishmania sp. foram novamente isoladas. Foi submetido a tratamento intramuscular (more) com pentamidina (4mg/kg). Parasitas da primeira e segunda biópsias foram identificados como Leishmania (Viannia) braziliensis; os da primeira biópsia eram mais sensíveis ao antimoniato de meglumina in vitro do que os da segunda biópsia. A lesão não reativou. Abstract in english This is a case report of a Brazilian soldier with cutaneous leishmaniasis. The lesion relapsed following two systemic treatments with meglumine antimoniate. The patient was treated with amphotericin B, which was interrupted due to poor tolerance. Following isolation of Leishmania sp., six intralesional infiltrations of meglumine antimoniate resulted in no response. Leishmania sp promastigotes were again isolated. The patient was submitted to intramuscular 4mg/kg pentamidi (more) ne. Parasites from the first and second biopsies were identified as Leishmania (Viannia) braziliensis; those isolated from the first biopsy were more sensitive to meglumine antimoniate in vitro than those isolated from the second biopsy. No relapse was observed.

Pimentel, Maria Inês Fernandes; Baptista, Cibele; Rubin, Évelyn Figueiredo; Vasconcellos, Érica de Camargo Ferreira e; Lyra, Marcelo Rosandiski; Salgueiro, Mariza de Matos; Saheki, Maurício Naoto; Rosalino, Cláudia Maria Valete; Madeira, Maria de Fátima; Silva, Aline Fagundes da; Confort, Eliame Mouta; Schubach, Armando de Oliveira

2011-04-01

274

In vitro anti-leishmania evaluation of nickel complexes with a triazolopyrimidine derivative against Leishmania infantum and Leishmania braziliensis.  

Science.gov (United States)

Studies on the anti-proliferative activity in vitro of seven ternary nickel (II) complexes with a triazolopyrimidine derivative and different aliphatic or aromatic amines as auxiliary ligands against promastigote and amastigote forms of Leishmania infantum and Leishmania braziliensis have been carried out. These compounds are not toxic for the host cells and two of them are effective at lower concentrations than the reference drug used in the present study (Glucantime). In general, the in vitro growth rate of Leishmania spp. was reduced, its capacity to infect cells was negatively affected and the multiplication of the amastigotes decreased. Ultrastructural analysis and metabolism excretion studies were executed in order to propose a possible mechanism for the action of the assayed compounds. Our results show that the potential mechanism is at the level of organelles membranes, either by direct action on the microtubules or by their disorganization, leading to vacuolization, degradation and ultimately cell death. PMID:22542591

Ramírez-Macías, Inmaculada; Maldonado, Carmen R; Marín, Clotilde; Olmo, Francisco; Gutiérrez-Sánchez, Ramón; Rosales, María J; Quirós, Miguel; Salas, Juan M; Sánchez-Moreno, Manuel

2012-03-04

275

In vitro anti-leishmania evaluation of nickel complexes with a triazolopyrimidine derivative against Leishmania infantum and Leishmania braziliensis.  

UK PubMed Central (United Kingdom)

Studies on the anti-proliferative activity in vitro of seven ternary nickel (II) complexes with a triazolopyrimidine derivative and different aliphatic or aromatic amines as auxiliary ligands against promastigote and amastigote forms of Leishmania infantum and Leishmania braziliensis have been carried out. These compounds are not toxic for the host cells and two of them are effective at lower concentrations than the reference drug used in the present study (Glucantime). In general, the in vitro growth rate of Leishmania spp. was reduced, its capacity to infect cells was negatively affected and the multiplication of the amastigotes decreased. Ultrastructural analysis and metabolism excretion studies were executed in order to propose a possible mechanism for the action of the assayed compounds. Our results show that the potential mechanism is at the level of organelles membranes, either by direct action on the microtubules or by their disorganization, leading to vacuolization, degradation and ultimately cell death.

Ramírez-Macías I; Maldonado CR; Marín C; Olmo F; Gutiérrez-Sánchez R; Rosales MJ; Quirós M; Salas JM; Sánchez-Moreno M

2012-07-01

276

Leishmania immune adherence reaction in vertebrates.  

UK PubMed Central (United Kingdom)

In normal human blood, C3-opsonized Leishmania promastigotes immune adhere to erythrocytes, a mechanism believed to enhance their clearance from blood and phagocytosis. Given the potential importance of this reaction in host defence against infection, the promastigote-erythrocyte interaction was studied in blood of individuals from one avian and 12 mammalian genera; [111In]-labelled promastigotes were found to bind only to primate erythrocytes. Nevertheless, previous experiments coincubating platelets isolated from nonprimate mammals with C3-opsonized promastigotes led to promastigote-platelet adherence. To ascertain whether this is a natural mechanism in nonprimate Leishmania infection, normal blood from members of Leishmania animal models of interest, dog, guinea-pig, hamster, mouse and rabbit, was infected ex vivo with promastigotes. Within 1 min of blood contact, the promastigote surface was loaded with platelets, rapidly evolving into large aggregates. These results confirm the physiological nature of the reaction and demonstrate that promastigote-erythrocyte and promastigote-platelet binding are the first parasite-host cell encounters after Leishmania invasion of primates and nonprimate mammals, respectively. Leishmania immune adherence shares the characteristics of the nonanticipatory immune systems, and we consider it should be viewed as an innate vertebrate host effector mechanism.

Domínguez M; Toraño A

2001-05-01

277

Generation of avirulent Leishmania parasites and induction of nitric oxide production in macrophages by using polyacrylic acid.  

Science.gov (United States)

Polyacrylic acid (PAA) is one of the anionic synthetic polyelectrolytes and is used in various immunological and pharmaceutical applications. PAA has been used as adjuvant in veterinary vaccines, in particular. However, to our knowledge, there are no studies that document immunostimulant properties of PAA in Leishmania infection. The main aim of this study was to investigate the interaction of Leishmania parasites with PAA: the possible effects on the infectivity of Leishmania promastigotes; and, induction of nitric oxide (NO) production in macrophages in vitro. The cytotoxicity of PAA on both macrophages and Leishmania infantum promastigotes were determined by MTT assay. NO production in the macrophage culture supernatant was measured by the Griess method. A significant, dose-dependent and time-dependent decrease in the infection index was observed after PAA exposure. The value of this decrease was found to be between 93% and 100% for all concentration and time points. PAA (molecular weight (MW) 30, 100 kDa at 1mg/1h)-exposed parasites stimulate NO production significantly at 48 h post-infection (PI), when compared to the control. This study demonstrates that Leishmania parasites lost their virulence upon interaction with PAA, and this interaction induced NO production in infected macrophages. These results may have important implications in the development of anti-leishmanial vaccines and amelioration of immune response. PMID:23238031

Elcicek, Serhat; Bagirova, Malahat; Allahverdiyev, Adil M

2012-12-10

278

Leishmanicidal, antibacterial, and antioxidant activities of Caryocar brasiliense Cambess leaves hydroethanolic extract/ Atividades leishmanicida, bactericida e antioxidante do extrato hidroetanólico das folhas de Caryocar brasiliense Cambess  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese As atividades antimicrobiana e antioxidante do extrato hidroetanólico das folhas de Caryocar brasiliense foram estudadas. O extrato demonstrou efeito leishmanicida sobre formas promastigotas de Leishmania amazonensis e atividade bactericida sobre estirpes de bactérias patogênicas para o homem. Além disso, o extrato demonstrou relevante capacidade antioxidante, similar às atividades da vitamina C e da rutina. Abstract in english The antimicrobial and antioxidant activities of the hydroethanolic extract from Caryocar brasiliense leaves were evaluated. The extract showed leishmanicidal effect against Leishmania amazonensis promastigote forms and bactericidal activity against some pathogenic bacteria. The extract also showed relevant antioxidant activity, similar to that of vitamin C and rutin.

Paula-Ju, Waldemar de; Rocha, Fabiana H.; Donatti, Lucélia; Fadel-Picheth, Cyntia M.T.; Weffort-Santos, Almeriane M.

2006-12-01

279

Leishmanicidal, antibacterial, and antioxidant activities of Caryocar brasiliense Cambess leaves hydroethanolic extract Atividades leishmanicida, bactericida e antioxidante do extrato hidroetanólico das folhas de Caryocar brasiliense Cambess  

Directory of Open Access Journals (Sweden)

Full Text Available The antimicrobial and antioxidant activities of the hydroethanolic extract from Caryocar brasiliense leaves were evaluated. The extract showed leishmanicidal effect against Leishmania amazonensis promastigote forms and bactericidal activity against some pathogenic bacteria. The extract also showed relevant antioxidant activity, similar to that of vitamin C and rutin.As atividades antimicrobiana e antioxidante do extrato hidroetanólico das folhas de Caryocar brasiliense foram estudadas. O extrato demonstrou efeito leishmanicida sobre formas promastigotas de Leishmania amazonensis e atividade bactericida sobre estirpes de bactérias patogênicas para o homem. Além disso, o extrato demonstrou relevante capacidade antioxidante, similar às atividades da vitamina C e da rutina.

Waldemar de Paula-Ju; Fabiana H. Rocha; Lucélia Donatti; Cyntia M.T. Fadel-Picheth; Almeriane M. Weffort-Santos

2006-01-01

280

Detecção de DNA de Leishmania braziliensis em pacientes de leishmaniose tegumentar americana/ Detection of Leishmania braziliensis DNA in American tegumentary leishmaniasis patients/ Detección de DNA de Leishmania braziliensis en pacientes de leishmaniose tegumentaria americana  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Foi realizado diagnóstico para leishmaniose tegumentar americana a partir de sangue de pacientes residentes em dois municípios endêmicos do estado de Pernambuco. O DNA de 119 amostras de sangue foi extraído e submetido a reação em cadeia da polimerase. Utilizaram-se primers do minicírculo do DNA do cinetoplasto (kDNA) de Leishmania braziliensis, circulante em Pernambuco, cuja seqüência-alvo gera um fragmento de 750 pares de bases. No total 58 (48,7%) indivíduos (more) apresentaram amplificação positiva e 61 (51,3%) negativa. Das amostras positivas para a PCR, 37 (? 64%) pertenciam a indivíduos tratados e sem lesão. Conclui-se que a técnica de PCR é eficaz para identificar o DNA de leishmânia em material de biópsias e em sangue venoso. Abstract in spanish Fue realizado diagnóstico para leishmaniosis tegumentaria americana a partir de sangre de pacientes residentes en dos municipios endémicos del estado de Pernambuco (Noreste de Brasil). El DNA de 119 muestras de sangre fue extraído y sometido a la reacción en cadena de la polimerasa. Se utilizaron primers del minicírculo del DNA del cinetoplasto (kDNA) de Leishmania braziliensis, circulante en Pernambuco, cuya secuencia blanco genera un fragmento de 750 pares de bases (more) . En total 58 (48,7%) individuos presentaron amplificación positiva y 61 (51,3%) negativa. De las muestras positivas para la PCR, 37 (?64%) pertenecían a individuos tratados y sin lesión. Se concluyó que la técnica de la PCR es eficaz para identificar el DNA de Leishmania en material de biopsias y en sangre venosa. Abstract in english Diagnostic tests for American tegumentary leishmaniasis were performed on blood samples of patients living in two endemic municipalities in the state of Pernambuco, Northeastern Brazil. DNA was extracted from 119 samples and used as template for polymerase chain reaction (PCR) analysis. The tests used primers specific for the kinetoplast mini-circle DNA (kDNA) of Leishmania braziliensis, a species circulating in Pernambuco, which amplify a 750 base pair target sequence. I (more) n total, 58 subjects (48.7%) showed positive PCR amplification and 61 (51.3%) were negative. Of the PCR-positive samples, 37 (?64%) were from treated, lesion-free subjects. In conclusion, the PCR technique is efficacious at identifying Leishmania DNA in biopsy and venous blood samples.

Martins, Leila; Alexandrino, Aline; Guimarães, Georgia

2010-06-01

 
 
 
 
281

Comparative genomic studies and in-silco strategies on Leishmania brazilensis, Leishmania infantum and Leishmania major: Conserved features, putative functions and potential drug target  

Directory of Open Access Journals (Sweden)

Full Text Available Leishmaniasis is a parasitic disease found largely in the tropics, which the World Health Organization has estimated infects 12 million people worldwide each year. More recently cases have been reported in Europe among intravenous drug users with HIV. At least 20 Leishmania species infect humans. New world parasite Leishmania. braziliensis is the causative agent of mucocutaneous Leishmaniasis. The old world species Leishmania. major and Leishmania. infantum, which are present in Africa, Europe and Asia, are parasites that cause cutaneous and visceral Leishmaniasis respectively. Aim of this Study is determination of major common genes and Protein identified Gene location on each of the chromosomes, and identification of a common protein drug target Promastigote surface antigen with available lead molecule acetylglucosamine (6-(acetylamino)-6-deoxyhexopyranose) and docking studies on those considered Leishmania species.

Rakesh N. R.; Pradeep S.

2013-01-01

282

T Cell Response of Asymptomatic Leishmania chagasi Infected Subjects to Recombinant Leishmania Antigens  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english In areas of Leishmania chagasi transmission the ability to control leishmania infection is associated with IFN-g production. In visceral leishmaniasis down-regulation of T cell responses is mediated by interleukin-10 (IL-10). In this study we evaluated the lymphoproliferative response, IFN-g and IL-10 production on lymphocyte cultures stimulated with recombinant leishmania antigens in subjects with asymptomatic L. chagasi infection. There was a statistically significant d (more) ifference in the lymphoproliferative response of the subjects with asymptomatic infection as compared to patients with visceral leishmaniasis and healthy subjects with respect to crude antigens (p<0.01), gp-63 (p<0.05) and hsp-70 (p<0.01), as well as between asymptomatic L. chagasi infected subjects and patients with visceral leishmaniasis with respect to the response to all antigens tested. The IFN-g production observed in the group with asymptomatic infection with all the three recombinant antigens tested was higher (p<0.01) than that observed in patients with visceral leishmaniasis and in healthy subjects. Furthermore, in individuals with asymptomatic infection, IL-10 levels in cultures stimulated with recombinant antigens were very low. This study shows that lymphocytes from individuals with asymptomatic L. chagasi infection are able to recognize recombinant leishmania antigens with production of a cytokine that is associated with leishmania killing.

Costa, Sérgio Ricardo; D'Oliveira Júnior, Argemiro; Bacellar, Olívia; Carvalho, Edgar M

1999-05-01

283

Efeito leishmanicida in vitro de Stachytarpheta cayennensis (Rich.) Vahl (Verbenaceae)/ In vitro leishmanicidal effect of Stachytarpheta cayennensis (Rich.) Vahl (Verbenaceae)  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A atividade anti-Leishmania do extrato hidroalcoólico de Stachytarpheta cayennensis, espécie utilizada popularmente no tratamento de lesões cutâneas causadas por Leishmania sp, foi testado em ensaios in vitro utilizando formas promastigotas de Leishmania braziliensis e L. amazonensis. O extrato hidroalcoólico foi preparado a partir das folhas secas e utilizado em culturas de L. amazonensis e L. braziliensis nas concentrações de 500 a 32,5 µg/mL. Após 24 horas as (more) formas promastigotas foram quantificadas para o cálculo da CI50. A citotoxicidade do extrato foi avaliada também em culturas de macrófagos peritoneais. O extrato apresentou efeito leishmanicida dose e espécie-dependente para promastigotas de Leishmania sendo mais eficaz para L. braziliensis. O extrato não apresentou efeito citotóxico quando utilizado nas culturas de macrófagos. Concluiu-se que o extrato hidroalcoólico de S. cayennensis inibe formas promastigotas de Leishmania in vitro o que poderia justificar, pelo menos parcialmente, o uso popular dessa espécie no tratamento de úlceras causadas por Leishmania. Abstract in english Leishmanicidal activity of the hydroalcoholic extract of Stachytarpheta cayennensis, species that is usually employed in ulcers caused by Leishmania, was evaluated in vitro using Leishmania braziliensis and L. amazonensis promastigotes forms. The hydroalcoholic extract was prepared from dried leaves and used in L. amazonensis and L. braziliensis promastigotes cultures at concentrations of 500 to 32.5 µg/mL. After 24 hours the promastigotes forms were quantified and the I (more) C50 was calculated. The cytotoxicity of the extract was evaluated using peritoneal macrophages. The extract presented a dose and specie-dependent leishmanicidal effect to Leishmania promastigotes, mainly to the L. braziliensis ones. The cytotoxic effect was not observed in macrophage cultures. In conclusion, the hydroalcoholic extract of S. cayennensis inhibits the growing of Leishmania promastigotes forms in vitro accounting for the folk use of this vegetal in skin ulcers caused by Leishmania.

Moreira, Rosilene C.R.; Costa, Graciomar C.; Lopes, Thaiana C.; Bezerra, Jeamile L.; Guerra, Rosane N.M.; Rebêlo, José Manuel M.; Ribeiro, Maria Nilce S.; Nascimento, Flávia R.F.; Costa, Jackson M.L.

2007-03-01

284

Efeito leishmanicida in vitro de Stachytarpheta cayennensis (Rich.) Vahl (Verbenaceae) In vitro leishmanicidal effect of Stachytarpheta cayennensis (Rich.) Vahl (Verbenaceae)  

Directory of Open Access Journals (Sweden)

Full Text Available A atividade anti-Leishmania do extrato hidroalcoólico de Stachytarpheta cayennensis, espécie utilizada popularmente no tratamento de lesões cutâneas causadas por Leishmania sp, foi testado em ensaios in vitro utilizando formas promastigotas de Leishmania braziliensis e L. amazonensis. O extrato hidroalcoólico foi preparado a partir das folhas secas e utilizado em culturas de L. amazonensis e L. braziliensis nas concentrações de 500 a 32,5 µg/mL. Após 24 horas as formas promastigotas foram quantificadas para o cálculo da CI50. A citotoxicidade do extrato foi avaliada também em culturas de macrófagos peritoneais. O extrato apresentou efeito leishmanicida dose e espécie-dependente para promastigotas de Leishmania sendo mais eficaz para L. braziliensis. O extrato não apresentou efeito citotóxico quando utilizado nas culturas de macrófagos. Concluiu-se que o extrato hidroalcoólico de S. cayennensis inibe formas promastigotas de Leishmania in vitro o que poderia justificar, pelo menos parcialmente, o uso popular dessa espécie no tratamento de úlceras causadas por Leishmania.Leishmanicidal activity of the hydroalcoholic extract of Stachytarpheta cayennensis, species that is usually employed in ulcers caused by Leishmania, was evaluated in vitro using Leishmania braziliensis and L. amazonensis promastigotes forms. The hydroalcoholic extract was prepared from dried leaves and used in L. amazonensis and L. braziliensis promastigotes cultures at concentrations of 500 to 32.5 µg/mL. After 24 hours the promastigotes forms were quantified and the IC50 was calculated. The cytotoxicity of the extract was evaluated using peritoneal macrophages. The extract presented a dose and specie-dependent leishmanicidal effect to Leishmania promastigotes, mainly to the L. braziliensis ones. The cytotoxic effect was not observed in macrophage cultures. In conclusion, the hydroalcoholic extract of S. cayennensis inhibits the growing of Leishmania promastigotes forms in vitro accounting for the folk use of this vegetal in skin ulcers caused by Leishmania.

Rosilene C.R. Moreira; Graciomar C. Costa; Thaiana C. Lopes; Jeamile L. Bezerra; Rosane N.M. Guerra; José Manuel M. Rebêlo; Maria Nilce S. Ribeiro; Flávia R.F. Nascimento; Jackson M.L. Costa

2007-01-01

285

Sergentomyia schwetzi is not a competent vector for Leishmania donovani and other Leishmania species pathogenic to humans.  

UK PubMed Central (United Kingdom)

BACKGROUND: Sand fly species of the genus Sergentomyia are proven vectors of reptilian Leishmania that are non-pathogenic to humans. However, a consideration of the role of Sergentomyia spp. in the circulation of mammalian leishmaniasis appears repeatedly in the literature and the possibility of Leishmania transmission to humans remains unclear. Here we studied the susceptibility of colonized Sergentomyia schwetzi to Leishmania donovani and two other Leishmania species pathogenic to humans: L. infantum and L. major. METHODS: Females of laboratory-reared S. schwetzi were infected by cultured Leishmania spp. by feeding through a chicken membrane, dissected at different time intervals post bloodmeal and examined by light microscopy for the abundance and location of infections. RESULTS: All three Leishmania species produced heavy late stage infections in Lutzomyia longipalpis or Phlebotomus duboscqi sand flies used as positive controls. In contrast, none of them completed their developmental cycle in Sergentomyia females; Leishmania promastigotes developed within the bloodmeal enclosed by the peritrophic matrix (PM) but were defecated together with the blood remnants, failing to establish a midgut infection. In S. schwetzi, the PM persisted significantly longer than in L. longipalpis and it was degraded almost simultaneously with defecation. Therefore, Leishmania transformation from procyclic to long nectomonad forms was delayed and parasites did not attach to the midgut epithelium. CONCLUSIONS: Sergentomyia schwetzi is refractory to human Leishmania species and the data indicate that the crucial aspect of the refractoriness is the relative timing of defecation versus PM degradation.

Sadlova J; Dvorak V; Seblova V; Warburg A; Votypka J; Volf P

2013-01-01

286

Leishmania (Viannia) panamensis - induced cutaneous leishmaniasis in susceptible and resistant mouse strains/ Leishmaniose cutânea induzida pela Leishmania (Viannia) panamensis em linhagens de camundongos suscetíveis e resistentes  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Estudamos a susceptibilidade à Leishmania (Viannia) panamensis em linhagens de camundongos BALB/c, DBA/2J, CBA/HJ e C57BL/6. Os camundongos da linhagem C57BL/6 eram resistentes, apresentando lesões autolimitantes na pata. Os das linhagens BALB/c e DBA/2J eram suscetíveis, apresentando edema na pata, evidente aos 20 dias pós-infecção que progrediu para uma lesão tipo tumoral nas fases tardias. Os animais da linhagem CBA/HJ apresentaram resistência intermediária. E (more) m contraste a outros modelos de leishmaniose cutânea murina, a lesão nos camundongos infectados pela L. (V.) panamensis mostrou ser restrita ao local de inoculação na pele. Estudamos também o desenvolvimento de resposta celular e anticorpos anti-Leishmania nas linhagens BALB/c c C57BL/6. A resposta proliferativa de células do linfonodo a antígenos de L. (V.) panamensis foi bifásica em ambas as linhagens. Uma resposta inicial foi observada com 20 dias de infecção, seguida por uma fase refratária entre 40 e 80 dias e uma segunda resposta ao redor do quarto mês de infecção. A resposta nesta segunda fase estava mais alta na linhagem C57BL/6 do que na BALB/c. Por outro lado, os camundongos BALB/c apresentaram níveis de anticorpo anti-Leishmania muito mais elevados que os da linhagem C57BL/6. O modelo e a correlação das variáveis imunológicas com o curso da infecção são discutidos. Abstract in english We studied the susceptibility to Leishmania (Viannia) panamensis in strains of mice. The C57BL/6 strain was resistant and showed self-controlled lesion at the injected foot pad. The BALB/c and DBA/2J strains were susceptible and showed a foot swelling that started day 20 post-infection and progressed to a tumour-like lesion in later period of observation. The CBA/HJ strain was found to be of intermediary resistance. In contrast to other known cutaneous leishmaniasis in mi (more) ce, the lesion in L. (V.) panamensis-infected mice was restricted to the inoculation site in the skin. In addition, we studied the development of cellular response and antibodies against Leishmania antigen in BALB/c and C57BL/6 strains. The proliferative response of lymph node cells against L. (V.) panamensis antigen was biphasic in both strains. An initial response was seen on day 20, followed by a refractory period between 40 and 80 days and a second response around fourth month post-infection. The response in the latter period was higher in C57BL/6 strain than in BALB/c strain. BALB/c strain presented much higher anti-Leishmania antibody level than C57BL/6 strain. The model and the correlation of immunological variables and the course of the infection are discussed.

Goto, H.; Rojas, J. I.; Sporrong, L.; Carreira, P. de; Sánchez, C.; Örn, A.

1995-12-01

287

Genes and Chromosomes of Leishmania infantum  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english During recent years, several Leishmania infantum genes have been cloned and characterized. Here, we have summarized the available information on the gene organization and expression in this protozoan parasite. From a comparative analysis, the following outstanding features were found to be common to most of the genes characterized: tandemly organized genes with conserved coding regions and divergent untranslated regions, polycistronic transcription and post-transcriptiona (more) l regulation of gene expression. The analysis of chromosomes of L. infantum by pulsed-field electrophoresis showed the existence of both size and number polymorphisms such that each strain has a distinctive molecular karyotype. Despite this variability, highly conserved physical linkage groups exists among different strains of L. infantum and even among Old World Leishmania species. Gene mapping on the L. infantum molecular karyotype evidenced a bias in chromosomal distribution of, at least, the evolutionary conserved genes

María Requena, Jose; Soto, Manuel; Quijada, Luis; Alonso, Carlos

1997-11-01

288

Shewasin A, an active pepsin homolog from the bacterium Shewanella amazonensis.  

UK PubMed Central (United Kingdom)

The view has been widely held that pepsin-like aspartic proteinases are found only in eukaryotes, and not in bacteria. However, a recent bioinformatics search [Rawlings ND & Bateman A (2009) BMC Genomics10, 437] revealed that, in seven of ? 1000 completely sequenced bacterial genomes, genes were present encoding polypeptides that displayed the requisite hallmark sequence motifs of pepsin-like aspartic proteinases. The implications of this theoretical observation prompted us to generate biochemical data to validate this finding experimentally. The aspartic proteinase gene from one of the seven identified bacterial species, Shewanella amazonensis, was expressed in Escherichia coli. The recombinant protein, termed shewasin A, was produced in soluble form, purified to homogeneity, and shown to display properties remarkably similar to those of pepsin-like aspartic proteinases. Shewasin A was maximally active at acidic pH values, cleaving a substrate that has been widely used for assessment of the proteolytic activity of other aspartic proteinases, and displayed a clear preference for cleaving peptide bonds between hydrophobic residues in the P1*P1' positions of the substrate. It was completely inhibited by the general inhibitor of aspartic proteinases, pepstatin, and mutation of one of the catalytic Asp residues (in the Asp-Thr-Gly motif of the N-terminal domain) resulted in complete loss of enzymatic activity. It can thus be concluded unequivocally that this Shewanella gene encodes an active pepsin-like aspartic proteinase. It is now beyond doubt that pepsin-like aspartic proteinases are not confined to eukaryotes, but are encoded within some species of bacteria. The distinctions between the bacterial and eukaryotic polypeptides are discussed and their evolutionary relationships are outlined.

Simões I; Faro R; Bur D; Kay J; Faro C

2011-09-01

289

Plants used in the treatment of leishmanial ulcers due to Leishmania (Viannia) braziliensis in an endemic area of Bahia, Brazil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Este trabalho relata as plantas usadas no tratamento da leishmaniose cutânea, causada por Leishmania (Viannia) braziliensis (L(V)b), na população rural da faixa litorânea produtora de cacau do estado da Bahia, Brasil. Um inquérito realizado entre 100 pacientes, identificou 49 espécies de plantas usadas para tratar úlceras de pele causadas por esta espécie de Leishmânia. As principais plantas usadas foram o cajueiro-branco (Anacardium occidentale - Anacardiaceae) (more) usado por 65% da população, a folha-fogo (Clidemia hirta - Melastomataceae) 39%, a alfavaca-grossa (Plectranthus amboinicus - Lamiaceae) 33%, o mastruz (Chenopodium ambrosioides - henopodiaceae) 31%, a erva-de-santa-maria (Solanum americanum - Solanaceae) 25% e a transagem (Plantago major - Plantaginaceae) 2%. Abstract in english This paper records the plants used in the treatment of cutaneous leishmaniasis due to Leishmania (Viannia) braziliensis (L(V)b) among the rural population of a cocoa- producing coastal area of Bahia state, Brazil. An enquiry conducted among a hundred patients identified 49 plant species used to treat skin ulceration caused by this Leishmania species. The principal plants used are caju-branco (Anacardium occidentale - Anacardiaceae), used by 65% of the population, folha-fo (more) go (Clidemia hirta - Melastomataceae) 39%, alfavaca-grossa (Plectranthus amboinicus - Lamiaceae) 33%, mastruz (Chenopodium ambrosioides - Chenopodiaceae) 31%, erva-de-santa-maria (Solatium americanum - Solanaceae) (25%) and transagem (Plantago major - Plantaginaceae.) 2%.

França, Flávio; Lago, Ednaldo L.; Marsden, Philip D.

1996-06-01

290

Plants used in the treatment of leishmanial ulcers due to Leishmania (Viannia) braziliensis in an endemic area of Bahia, Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available This paper records the plants used in the treatment of cutaneous leishmaniasis due to Leishmania (Viannia) braziliensis (L(V)b) among the rural population of a cocoa- producing coastal area of Bahia state, Brazil. An enquiry conducted among a hundred patients identified 49 plant species used to treat skin ulceration caused by this Leishmania species. The principal plants used are caju-branco (Anacardium occidentale - Anacardiaceae), used by 65% of the population, folha-fogo (Clidemia hirta - Melastomataceae) 39%, alfavaca-grossa (Plectranthus amboinicus - Lamiaceae) 33%, mastruz (Chenopodium ambrosioides - Chenopodiaceae) 31%, erva-de-santa-maria (Solatium americanum - Solanaceae) (25%) and transagem (Plantago major - Plantaginaceae.) 2%.Este trabalho relata as plantas usadas no tratamento da leishmaniose cutânea, causada por Leishmania (Viannia) braziliensis (L(V)b), na população rural da faixa litorânea produtora de cacau do estado da Bahia, Brasil. Um inquérito realizado entre 100 pacientes, identificou 49 espécies de plantas usadas para tratar úlceras de pele causadas por esta espécie de Leishmânia. As principais plantas usadas foram o cajueiro-branco (Anacardium occidentale - Anacardiaceae) usado por 65% da população, a folha-fogo (Clidemia hirta - Melastomataceae) 39%, a alfavaca-grossa (Plectranthus amboinicus - Lamiaceae) 33%, o mastruz (Chenopodium ambrosioides - henopodiaceae) 31%, a erva-de-santa-maria (Solanum americanum - Solanaceae) 25% e a transagem (Plantago major - Plantaginaceae) 2%.

Flávio França; Ednaldo L. Lago; Philip D. Marsden

1996-01-01

291

Clonal variation within a mucosal isolate derived from a patient with Leishmania (Viannia) braziliensis infection Variação clonal de um isolado derivado de um paciente com infecção mucosa pela Leishmania (Viannia) braziliensis  

Directory of Open Access Journals (Sweden)

Full Text Available Three isolates over 5 years from a patient with persistent relapsing mucosal leishmaniasis due to Leishmania (Viannia) braziliensis and 7 clones from one of these isolates were studied by zymodemes and scrodemes analysis. Results showed evidences of clonal phenotypic variation. Eight isoenzymes markers demonstrated clear differences on Cellulose Acetate (CA) and thin starch gel electrophoresis. Also a panel of specific monoclonal antibodies showed such differences. Our observations provide additional evidence that Leishmania (Viannia) braziliensis is composed by subpopulations of parasites with peculiar biochemical and antigenic characteristics.No transcurso de um período de 5 anos foram estudados 3 isolados de um paciente com leishmaniose mucosa recidivante causada pela Leishmania (Viannia) braziliensis e 7 clones de um desses isolados. Este estudo foi feito pela análise dos serodemas e zimodemas. Os resultados indicaram a ocorrência de variações fenotípicas clonais. Oito marcadores isoenzimáticos demonstraram diferenças nos padrões eletroforéticos em Acetato de Celulose (AC), bem como em camada fina de amido. Da mesma forma foram consultadas diferenças em um painel de anticorpos monoclonais específicos e subespecíficos. Nossas observações indicam ainda que a Leishmania (Viannia) braziliensis está composta por subpopulações de parasitas com características bioquímicas e antigênicas peculiares.

César Augusto Cuba-Cuba; David Evans; Ana de Cassia Rosa; Philip Davis Marsden

1991-01-01

292

Clonal variation within a mucosal isolate derived from a patient with Leishmania (Viannia) braziliensis infection/ Variação clonal de um isolado derivado de um paciente com infecção mucosa pela Leishmania (Viannia) braziliensis  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese No transcurso de um período de 5 anos foram estudados 3 isolados de um paciente com leishmaniose mucosa recidivante causada pela Leishmania (Viannia) braziliensis e 7 clones de um desses isolados. Este estudo foi feito pela análise dos serodemas e zimodemas. Os resultados indicaram a ocorrência de variações fenotípicas clonais. Oito marcadores isoenzimáticos demonstraram diferenças nos padrões eletroforéticos em Acetato de Celulose (AC), bem como em camada fina (more) de amido. Da mesma forma foram consultadas diferenças em um painel de anticorpos monoclonais específicos e subespecíficos. Nossas observações indicam ainda que a Leishmania (Viannia) braziliensis está composta por subpopulações de parasitas com características bioquímicas e antigênicas peculiares. Abstract in english Three isolates over 5 years from a patient with persistent relapsing mucosal leishmaniasis due to Leishmania (Viannia) braziliensis and 7 clones from one of these isolates were studied by zymodemes and scrodemes analysis. Results showed evidences of clonal phenotypic variation. Eight isoenzymes markers demonstrated clear differences on Cellulose Acetate (CA) and thin starch gel electrophoresis. Also a panel of specific monoclonal antibodies showed such differences. Our ob (more) servations provide additional evidence that Leishmania (Viannia) braziliensis is composed by subpopulations of parasites with peculiar biochemical and antigenic characteristics.

Cuba-Cuba, César Augusto; Evans, David; Rosa, Ana de Cassia; Marsden, Philip Davis

1991-10-01

293

Seroprevalence of anti-Leishmania spp. antibodies in rural dogs from the city of Monte Negro, State of Rondônia, Brazil Soroprevalência de anticorpos anti-Leishmania spp. em cães rurais do município de Monte Negro, Estado de Rondônia, Brasil  

Directory of Open Access Journals (Sweden)

Full Text Available The present study assessed the prevalence of anti-Leishmania spp. antibodies in dogs from the city of Monte Negro, State of Rondônia, Brazil. ELISA (NE > 3) and IFAT (>1:40) were used to evaluate 161 serum samples collected from rural dogs from Monte Negro. Forty-five (27.9%) dogs were positive by ELISA tests and five (3.1%) were positive by IFAT. The present study showed for the first time the frequency of exposure to Leishmania spp. in dogs in the State of Rondônia, Amazon Region.O presente estudo determinou a prevalência de anticorpos anti-Leishmania spp. em cães do município de Monte Negro, Estado de Rondônia, Brasil. Foram utilizados os testes de ELISA (NE > 3) e RIFI (>1:40) para avaliar 161 amostras de soro de cães da zona rural do município. Quarenta e cinco cães (27,9%) reagiram no teste de ELISA e cinco (3,1%) na RIFI. O presente estudo demonstra pela primeira vez a freqüência de exposição por Leishmania spp. em cães de Rondônia, Região Amazônica.

Daniel M. Aguiar; Trícia Maria F. de Sousa Oliveira; Guacyara T. Cavalcante; Marcelo B. Labruna; Luis Marcelo A. Camargo; Rosangela Z. Machado; Solange M. Gennari

2010-01-01

294

Qualidade espermática de sêmen de cães naturalmente infectados por Leishmania sp: / Semen quality of dogs naturally infected by Leishmania sp  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Avaliaram-se alterações espermáticas associadas à infecção por leishmaniose no sêmen de cães naturalmente infectados, utilizando-se, durante oito semanas consecutivas, ejaculados de seis cães soronegativos e seis cães soropositivos. As amostras foram colhidas uma vez por semana e avaliadas quanto ao volume, concentração, motilidade, vigor, morfologia espermática, integridade da cromatina, avaliação simultânea da integridade da membrana plasmática, acrosso (more) ma e potencial mitocondrial. Concomitantemente foram dosadas a proteína total do plasma seminal e sanguíneo. A leishmaniose visceral causou aumento dos defeitos maiores e menores nos espermatozoides dos animais acometidos pelo estágio moderado a severo da doença. Em estágios mais avançados da enfermidade, a integridade das membranas acrossomal e plasmática foi afetada negativamente. Não foi possível estabelecer um critério quanto à avaliação do potencial mitocondrial. A incidência de alterações morfológicas nos animais acometidos não promoveu aumento de injurias à cromatina. Todos os animais com leishmaniose apresentaram hiperproteinemia do sêmen. Abstract in english The spermatic changes associated with the natural infection in dogs by Leishmania sp was evaluated during eight consecutive weeks, using ejaculates of six seronegative and six seropositive dogs. The samples were collected once a week and evaluated for volume, concentration, motility, vigor, sperm morphology, chromatin integrity, simultaneous evaluation of the plasmatic membrane integrity, acrosome, and mitochondrial potential. The total proteins of the seminal plasma and (more) blood were measured. The visceral leishmaniasis caused increase of major and minor defects in spermatozoa of animals attacked by moderate to severe stages of the disease. In more advanced stages of the illness, the acrosomal and plasmatic membranes integrity was adversely affected. It was not possible to establish a pattern refering the evaluation of the mitochondrial potential. The incidence of morphological changes in the seropositive animals did not promote an increase of injuries to the chromatin. All animals with leishmaniasis presented hyperproteinemia of the semen.

Labat, É.; Carreira, J.T.; Matsukuma, B.H.; Martins, M.T.A.; Lima, V.M.F.; Bomfim, S.R.M.; Perri, S.H.V.; Koivisto, M.B.

2010-06-01

295

Qualidade espermática de sêmen de cães naturalmente infectados por Leishmania sp: Semen quality of dogs naturally infected by Leishmania sp  

Directory of Open Access Journals (Sweden)

Full Text Available Avaliaram-se alterações espermáticas associadas à infecção por leishmaniose no sêmen de cães naturalmente infectados, utilizando-se, durante oito semanas consecutivas, ejaculados de seis cães soronegativos e seis cães soropositivos. As amostras foram colhidas uma vez por semana e avaliadas quanto ao volume, concentração, motilidade, vigor, morfologia espermática, integridade da cromatina, avaliação simultânea da integridade da membrana plasmática, acrossoma e potencial mitocondrial. Concomitantemente foram dosadas a proteína total do plasma seminal e sanguíneo. A leishmaniose visceral causou aumento dos defeitos maiores e menores nos espermatozoides dos animais acometidos pelo estágio moderado a severo da doença. Em estágios mais avançados da enfermidade, a integridade das membranas acrossomal e plasmática foi afetada negativamente. Não foi possível estabelecer um critério quanto à avaliação do potencial mitocondrial. A incidência de alterações morfológicas nos animais acometidos não promoveu aumento de injurias à cromatina. Todos os animais com leishmaniose apresentaram hiperproteinemia do sêmen.The spermatic changes associated with the natural infection in dogs by Leishmania sp was evaluated during eight consecutive weeks, using ejaculates of six seronegative and six seropositive dogs. The samples were collected once a week and evaluated for volume, concentration, motility, vigor, sperm morphology, chromatin integrity, simultaneous evaluation of the plasmatic membrane integrity, acrosome, and mitochondrial potential. The total proteins of the seminal plasma and blood were measured. The visceral leishmaniasis caused increase of major and minor defects in spermatozoa of animals attacked by moderate to severe stages of the disease. In more advanced stages of the illness, the acrosomal and plasmatic membranes integrity was adversely affected. It was not possible to establish a pattern refering the evaluation of the mitochondrial potential. The incidence of morphological changes in the seropositive animals did not promote an increase of injuries to the chromatin. All animals with leishmaniasis presented hyperproteinemia of the semen.

É. Labat; J.T. Carreira; B.H. Matsukuma; M.T.A. Martins; V.M.F. Lima; S.R.M. Bomfim; S.H.V. Perri; M.B. Koivisto

2010-01-01

296

Leishmania donovani triose phosphate isomerase: a potential vaccine target against visceral leishmaniasis.  

UK PubMed Central (United Kingdom)

Visceral leishmaniasis (VL) is one of the most important parasitic diseases with approximately 350 million people at risk. Due to the non availability of an ideal drug, development of a safe, effective, and affordable vaccine could be a solution for control and prevention of this disease. In this study, a potential Th1 stimulatory protein- Triose phosphate isomerase (TPI), a glycolytic enzyme, identified through proteomics from a fraction of Leishmania donovani soluble antigen ranging from 89.9-97.1 kDa, was assessed for its potential as a suitable vaccine candidate. The protein- L. donovani TPI (LdTPI) was cloned, expressed and purified which exhibited the homology of 99% with L. infantum TPI. The rLdTPI was further evaluated for its immunogenicity by lymphoproliferative response (LTT), nitric oxide (NO) production and estimation of cytokines in cured Leishmania patients/hamster. It elicited strong LTT response in cured patients as well as NO production in cured hamsters and stimulated remarkable Th1-type cellular responses including IFN-ã and IL-12 with extremely lower level of IL-10 in Leishmania-infected cured/exposed patients PBMCs in vitro. Vaccination with LdTPI-DNA construct protected naive golden hamsters from virulent L. donovani challenge unambiguously (?90%). The vaccinated hamsters demonstrated a surge in IFN-ã, TNF-á and IL-12 levels but extreme down-regulation of IL-10 and IL-4 along with profound delayed type hypersensitivity and increased levels of Leishmania-specific IgG2 antibody. Thus, the results are suggestive of the protein having the potential of a strong candidate vaccine.

Kushawaha PK; Gupta R; Tripathi CD; Khare P; Jaiswal AK; Sundar S; Dube A

2012-01-01

297

In vitro cytocidal effects of the essential oil from Croton cajucara (red sacaca) and its major constituent 7- hydroxycalamenene against Leishmania chagasi.  

UK PubMed Central (United Kingdom)

BackgroundVisceral leishmaniasis is the most serious form of leishmaniasis and can be lethal if left untreated. Currently available treatments for these parasitic diseases are frequently associated to severe side effects. The leaves of Croton cajucara are used as an infusion in popular medicine to combat several diseases. Previous studies have demonstrated that the linalool-rich essential oil from C. cajucara (white sacaca) is extremely efficient against the tegumentary specie Leishmania amazonensis. In this study, we investigated the effects of the 7-hydroxycalamenene-rich essential oil from the leaves of C. cajucara (red sacaca) against Leishmania chagasi, as well as on the interaction of these parasites with host cells. METHODS: Promastigotes were treated with different concentrations of the essential oil for determination of its minimum inhibitory concentration (MIC). In addition, the effects of the essential oil on parasite ultrastructure were analyzed by transmission electron microscopy. To evaluate its efficacy against infected cells, mouse peritoneal macrophages infected with L. chagasi promastigotes were treated with the inhibitory and sub-inhibitory concentrations of the essential oil. RESULTS: The minimum inhibitory concentrations of the essential oil and its purified component 7-hydroxycalamenene against L. chagasi were 250 and 15.6 mug/mL, respectively. Transmission electron microscopy analysis revealed important nuclear and kinetoplastic alterations in L. chagasi promastigotes. Pre-treatment of macrophages and parasites with the essential oil reduced parasite/macrophage interaction by 52.8%, while it increased the production of nitric oxide by L. chagasi-infected macrophages by 80%. CONCLUSION: These results indicate that the 7-hydroxycalamenene-rich essential oil from C. cajucara is a promising source of leishmanicidal compounds.

Rodrigues IA; Azevedo MM; Chaves FC; Bizzo HR; Corte-Real S; Alviano DS; Alviano CS; Rosa MS; Vermelho AB

2013-10-01

298

Mucosal leishmaniasis due to Leishmania (Viannia) braziliensis L(V)b in Três Braços, Bahia-Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available Brazilian mucosal leshmaniasis is briefly reviewed, emphasis being given to recent advances clinical management. Patients continue to occupy much hospital bed space and in some cases are notoriously difficult to treat. Indefinite follow up is recommended. Many aspects of the aetiology remain mysterious although Leishmania (Viannia) braziliensis is the most common organism isolated. Perspectives for a more effective treatment, oral and cheap, are still remote.Neste trabalho, é feita uma breve revisão da leishmaniose mucosa existente no Brasil enfatizando os recentes avanços no tratamento clinico. Os pacientes frequentemente ocupam os leitos hospitalares e alguns casos são notoriamente difíceis de tratar. Recomenda-se um acompanhamento por tempo indefinido. Embora a Leishmania (Viannia) braziliensis seja o microorganismo mais comumente isolado, muitos aspectos da etiologia permanecem obscuros. As perpectivas de um tratamento oral e barato são ainda remotas.

Philip Davis Marsden

1994-01-01

299

Mucosal leishmaniasis due to Leishmania (Viannia) braziliensis L(V)b in Três Braços, Bahia-Brazil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Neste trabalho, é feita uma breve revisão da leishmaniose mucosa existente no Brasil enfatizando os recentes avanços no tratamento clinico. Os pacientes frequentemente ocupam os leitos hospitalares e alguns casos são notoriamente difíceis de tratar. Recomenda-se um acompanhamento por tempo indefinido. Embora a Leishmania (Viannia) braziliensis seja o microorganismo mais comumente isolado, muitos aspectos da etiologia permanecem obscuros. As perpectivas de um tratamento oral e barato são ainda remotas. Abstract in english Brazilian mucosal leshmaniasis is briefly reviewed, emphasis being given to recent advances clinical management. Patients continue to occupy much hospital bed space and in some cases are notoriously difficult to treat. Indefinite follow up is recommended. Many aspects of the aetiology remain mysterious although Leishmania (Viannia) braziliensis is the most common organism isolated. Perspectives for a more effective treatment, oral and cheap, are still remote.

Marsden, Philip Davis

1994-06-01

300

Leishmania (Leishmania) infantum chagasi em canídeos silvestres mantidos em cativeiro, no Estado de Mato Grosso/ Leishmania (Leishmania) infantum chagasi in wild canids kept in captivity in the State of Mato Grosso  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese INTRODUÇÃO: Leishmaniose visceral é uma zoonose que acomete diversos mamíferos tendo os canídeos domésticos como principais reservatórios em ambiente urbano. A presente nota descreve a infecção de canídeos silvestres por Leishmania (Leishmania) infantum chagasi mantidos em cativeiro no Estado de Mato Grosso, Brasil. MÉTODOS: De seis raposas (Cerdocyon thous) e um cachorro vinagre (Spheotos venaticus), foram coletadas amostras de pele, medula óssea e linfonodo (more) para detecção e caracterização de Leishmania sp pela técnica de PCR-RFLP. RESULTADOS: Todos as animais pesquisados apresentaram-se positivos para Leishmania (L.) infantum chagasi. CONCLUSÕES: Destaca-se a importância de monitoramento adequado dos mesmos, além do maior controle desta enfermidade já que estes animais estão em ambientes de recreação pública. Abstract in english INTRODUCTION: Visceral leishmaniasis is a zoonosis that affects many mammals, and domestic canids are the main reservoirs in urban environments. This note describes infection by Leishmania (Leishmania) infantum chagasi among wild canids kept in captivity in the State of Mato Grosso, Brazil. METHODS: Skin, bone marrow and lymph node samples were collected from six crab-eating foxes (Cerdocyon thous) and one bush dog (Spheotos venaticus), in order to detect and characterize (more) Leishmania using the PCR-RFLP technique. RESULTS: All the animals studied were positive for Leishmania (L.) infantum chagasi. CONCLUSIONS: This study highlights the importance of adequate monitoring of these animals, as well as greater control of this disease, given that these animals are in a public recreation environment.

Souza, Nely Pinheiro; Almeida, Arleana do Bom Parto Ferreira de; Freitas, Tatiana Pádua Tavares de; Paz, Regina Celia Rodrigues da; Dutra, Valéria; Nakazato, Luciano; Sousa, Valéria Régia Franco

2010-06-01

 
 
 
 
301

Immune Adherence–mediated Opsonophagocytosis: ?The Mechanism of Leishmania Infection  

Digital Repository Infrastructure Vision for European Research (DRIVER)

To mimic the sandfly pool feeding process and characterize the cellular and biochemical events that occur during the early stages of promastigote–host interaction, we developed an ex vivo model of human blood infection with Leishmania promastigotes. Within 30 s of blood contact, Leishmania promas...

Domínguez, Mercedes; Toraño, Alfredo

302

Leukodepletion Filters for Prevention of Transfusion Transmission Of Leishmania  

Canada Institute for Scientific and Technical Information (Canada)

BACKGROUND: Leishmania is an intracellular parasite of monocytes transmissible by transfusion. The feasibility of reducing Leishmania with leukodepletion filters was studied. At collection, infected blood contains the amastigote form of Leishmania within monocytes. Amastigotes cause the rupture of monocytes releasing free amastigotes that convert to promastigotes which exist extracellularly at blood storage temperatures. Leukodepletion filters were tested at various time points in this process. STUDY DESIGN AND METHODS: Blood products were infected with Leishmania organisms then filtered: 1. using whole blood filters at collection, 2. using bedside filters after storage, and 3. to determine whether free promastigotes could be eliminated. RESULTS: Filtration at collection reduced Leishmania by three to four logs or to the level of detection. Filtration of infected packed red cells after two weeks of storage showed a reduction of Leishmania by four logs. Filtration resulted in a six to eight log reduction in promastigotes in either the presence or in the absence of white cells within the filter. CONCLUSION: Filtration at the time of collection and after storage of Leishmania infected blood resulted in a substantial reduction of free and intracellular organisms. There is currently no donor screen for Leishmania. Until adequate testing is developed, the use of leukodepletion filters could add to the safety of the blood supply.

2006-01-01

303

The genome of the kinetoplastid parasite, Leishmania major  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Leishmania species cause a spectrum of human diseases in tropical and subtropical regions of the world. We have sequenced the 36 chromosomes of the 32.8-megabase haploid genome of Leishmania major (Friedlin strain) and predict 911 RNA genes, 39 pseudogenes, and 8272 protein-coding genes, of which 36...

Ivens, AC; Peacock, CS; Worthey, CS; Murphy, L; Aggarwal, G; Berriman, M; Sisk, E; Rajandream, MA; Adlem, E; Aert, R; Anupama, A

304

Avaliaçao do efeito do extrato de casca de cajueiro-branco (Anacardium occidentale L.) Sobre A infecção por Leishmania (Viannia) brasiliensis  

Directory of Open Access Journals (Sweden)

Full Text Available Este trabalho apresenta uma avaliação do efeito terapêutico do extrato hidroalcólico da casca de Anacardium occidentale L sobre a Leishmania (Viannia) brasiliensis. No modelo in vitro o extrato vegetal mostrou-se ativo contra promastigotas do parasita, contrastando com o modelo in vivo, onde não se observou qualquer atividade curativa.This paper presents an evaluation of the therapeutic effect of an hydroalcoholic extract of A. occidentale L. bark against Leishmania (Viannia) brasiliensis. The extract showed high activity in the in vitro model against the promastigotes ofthis species. However in the in vivo model no curative activity was observed.

Flávio França; César A.C. Cuba; Eduardo A. Moreira; Obdúlio Miguel; Marcos Almeida; Maria de L. das Virgens; Philip D. Marsden

1993-01-01

305

Avaliaçao do efeito do extrato de casca de cajueiro-branco (Anacardium occidentale L.) Sobre A infecção por Leishmania (Viannia) brasiliensis  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Este trabalho apresenta uma avaliação do efeito terapêutico do extrato hidroalcólico da casca de Anacardium occidentale L sobre a Leishmania (Viannia) brasiliensis. No modelo in vitro o extrato vegetal mostrou-se ativo contra promastigotas do parasita, contrastando com o modelo in vivo, onde não se observou qualquer atividade curativa. Abstract in english This paper presents an evaluation of the therapeutic effect of an hydroalcoholic extract of A. occidentale L. bark against Leishmania (Viannia) brasiliensis. The extract showed high activity in the in vitro model against the promastigotes ofthis species. However in the in vivo model no curative activity was observed.

França, Flávio; Cuba, César A.C.; Moreira, Eduardo A.; Miguel, Obdúlio; Almeida, Marcos; Virgens, Maria de L. das; Marsden, Philip D.

1993-09-01

306

Quantiferon-Leishmania as an Epidemiological Tool for Evaluating the Exposure to Leishmania Infection  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The aim of the present preliminary study was to investigate the potential of measurement of IFN-? secretion by T cells into blood plasma using QuantiFERON assay with leishmanial antigens to determine the presence of Leishmania infection. Blood samples from cured visceral (N = 18), and cutaneous (N =...

Turgay, Nevin; Balcioglu, I. Cuneyt; Toz, Seray Ozensoy; Ozbel, Yusuf; Jones, Stephen L.

307

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

UK PubMed Central (United Kingdom)

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 10 2 and 2.5 x 10 6 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.

Loría-Cervera EN; Sosa-Bibiano EI; Villanueva-Lizama LE; Van Wynsberghe NR; Canto-Lara SB; Batún-Cutz JL; Andrade-Narváez FJ

2013-04-01

308

Molecular and parasitological detection of Leishmania spp. in dogs caught in Palmas, TO, Brazil Detecção molecular e parasitológica de Leishmania spp. em cães capturados em Palmas, TO, Brasil  

Directory of Open Access Journals (Sweden)

Full Text Available This study evaluated occurrences of Leishmania infantum in dogs in the municipality of Palmas, Tocantins, comparing diagnostic data obtained using the polymerase chain reaction (PCR) and parasitological diagnosis. Blood samples and lymph node aspirates were collected from 63 dogs of males and females and various ages and races, with or without owners, between August 2009 and June 2010. Slides containing smears of lymph node aspirates were stained with Giemsa stained. In PCR, the 145 bp target sequence of the LT1 fragment, located in the Leishmania donovani kDNA minicircle was detected using the RV1 and RV2 oligonucleotide primers. The chi-square test revealed that there was a significant relationship between the symptoms and dogs that were positive for visceral leishmaniasis (VL). The parasitological investigation showed concordance of 66.7% with PCR on blood and 84.1% with PCR on lymph node aspirate. In addition to these tests, evaluations of the diagnoses in parallel and in series were conducted, which showed concordances with the parasitological test of 76.2% and 74.6%, respectively. The results make it possible to suggest that PCR on lymph nodes should be used in evaluating large populations (surveys) and that the parasitological test should be used for initial clinical evaluations in veterinary consultation offices.Avaliou-se a ocorrência de Leishmania infantum em cães do município de Palmas-TO, comparando dados diagnósticos obtidos pela Reação em Cadeia da Polimerase (PCR) e pelo diagnóstico parasitológico. Foram coletadas amostras de sangue e de aspirado de linfonodo de 63 cães machos e fêmeas, várias idades e raças, domiciliares ou não de agosto de 2009 a junho de 2010. As lâminas contendo esfregaço dos aspirados de linfonodos foram coradas pelo corante Giemsa. Na PCR, a sequência alvo de 145 pb do fragmento LT1, situado no minicírculo do kDNA do grupo Leishmania donovani, foi detectada através dos oligonucleotídeos iniciadores RV1 e RV2. O teste ?² (Qui-quadrado), demonstrou haver relação significativa entre a sintomatologia e a positividade dos cães para Leishmaniose Visceral (LV). O exame parasitológico mostrou uma concordância de 66,7% com a PCR em sangue e 84,1% com a PCR de aspirado de linfonodo. Além destas análises, houve a avaliação dos diagnósticos em paralelo e em série, onde as concordâncias com o exame parasitológico foram de 76,2% e 74,6%, respectivamente. Os resultados permitem sugerir a utilização da PCR de linfonodos na avaliação de grandes populações (inquéritos), e o exame parasitológico para a avaliação clínica inicial em consultórios veterinários.

Natália Melquie Monteiro Teles; Maria Augusta Paes Agostini; Júlio Gomes Bigeli; Rosalba Valadares Noleto; Jaqueline Dias Oliveira; Waldesse Piragé de Oliveira Junior

2012-01-01

309

Molecular and parasitological detection of Leishmania spp. in dogs caught in Palmas, TO, Brazil/ Detecção molecular e parasitológica de Leishmania spp. em cães capturados em Palmas, TO, Brasil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Avaliou-se a ocorrência de Leishmania infantum em cães do município de Palmas-TO, comparando dados diagnósticos obtidos pela Reação em Cadeia da Polimerase (PCR) e pelo diagnóstico parasitológico. Foram coletadas amostras de sangue e de aspirado de linfonodo de 63 cães machos e fêmeas, várias idades e raças, domiciliares ou não de agosto de 2009 a junho de 2010. As lâminas contendo esfregaço dos aspirados de linfonodos foram coradas pelo corante Giemsa. Na (more) PCR, a sequência alvo de 145 pb do fragmento LT1, situado no minicírculo do kDNA do grupo Leishmania donovani, foi detectada através dos oligonucleotídeos iniciadores RV1 e RV2. O teste ?² (Qui-quadrado), demonstrou haver relação significativa entre a sintomatologia e a positividade dos cães para Leishmaniose Visceral (LV). O exame parasitológico mostrou uma concordância de 66,7% com a PCR em sangue e 84,1% com a PCR de aspirado de linfonodo. Além destas análises, houve a avaliação dos diagnósticos em paralelo e em série, onde as concordâncias com o exame parasitológico foram de 76,2% e 74,6%, respectivamente. Os resultados permitem sugerir a utilização da PCR de linfonodos na avaliação de grandes populações (inquéritos), e o exame parasitológico para a avaliação clínica inicial em consultórios veterinários. Abstract in english This study evaluated occurrences of Leishmania infantum in dogs in the municipality of Palmas, Tocantins, comparing diagnostic data obtained using the polymerase chain reaction (PCR) and parasitological diagnosis. Blood samples and lymph node aspirates were collected from 63 dogs of males and females and various ages and races, with or without owners, between August 2009 and June 2010. Slides containing smears of lymph node aspirates were stained with Giemsa stained. In P (more) CR, the 145 bp target sequence of the LT1 fragment, located in the Leishmania donovani kDNA minicircle was detected using the RV1 and RV2 oligonucleotide primers. The chi-square test revealed that there was a significant relationship between the symptoms and dogs that were positive for visceral leishmaniasis (VL). The parasitological investigation showed concordance of 66.7% with PCR on blood and 84.1% with PCR on lymph node aspirate. In addition to these tests, evaluations of the diagnoses in parallel and in series were conducted, which showed concordances with the parasitological test of 76.2% and 74.6%, respectively. The results make it possible to suggest that PCR on lymph nodes should be used in evaluating large populations (surveys) and that the parasitological test should be used for initial clinical evaluations in veterinary consultation offices.

Teles, Natália Melquie Monteiro; Agostini, Maria Augusta Paes; Bigeli, Júlio Gomes; Noleto, Rosalba Valadares; Oliveira, Jaqueline Dias; Oliveira Junior, Waldesse Piragé de

2012-09-01

310

Molecular detection of Leishmania infection due to Leishmania major and Leishmania turanica in the vectors and reservoir host in Iran.  

Science.gov (United States)

An epidemiological study was carried out on the vectors and reservoirs of cutaneous leishmaniasis in rural areas of Damghan district, Semnan province, central Iran, during 2008-2009. Totally, 6110 sand flies were collected using sticky papers and were subjected to molecular methods for detection of Leishmania parasite. Phlebotomus papatasi Scopoli was the common species in outdoor and indoor resting places. Polymerase chain reaction technique showed that 24 out of 218 P. papatasi (11%) and 4 out of 62 Phlebotomus caucasicus Marzinovskyi (6.5%) were positive for parasites Leishmania major Yakimoff and Schokhor. Twenty-one rodent reservoir hosts captured using Sherman traps were identified as Rhombomys opimus Lichtenstein (95%) and Meriones libycus Lichtenstein (5%). Microscopic investigation on blood smear of the animals for amastigote parasites revealed 8 (40%) rodents infected with R. opimus. L. major infection in these animals was then confirmed by polymerase chain reaction against internal transcribed spacer ribosomal DNA (rDNA) loci of the parasite followed by restriction fragment length polymorphism. Further, sequence analysis of 297 bp of ITS1-rDNA loci revealed the presence of L. major and Leishmania turanica in P. papatasi, and L. major in R. opimus. This is the first molecular report of L. major infection in both vectors (P. papatasi and P. caucasicus) and reservoir host (R. opimus) in this region. The results indicated that P. papatas was the primary vector of the disease and circulating the parasite between human and reservoirs, and P. caucasicus could be considered as a secondary vector. Further, our study showed that R. opimus is the most important host reservoir for maintenance of the parasite source in the area. PMID:20575646

Rassi, Yavar; Oshaghi, Mohammad Ali; Azani, Sadegh Mohammadi; Abaie, Mohammad Reza; Rafizadeh, Sina; Mohebai, Mehdi; Mohtarami, Fatemeh; Zeinali, Mohammad kazem

2010-06-24

311

Molecular detection of Leishmania infection due to Leishmania major and Leishmania turanica in the vectors and reservoir host in Iran.  

UK PubMed Central (United Kingdom)

An epidemiological study was carried out on the vectors and reservoirs of cutaneous leishmaniasis in rural areas of Damghan district, Semnan province, central Iran, during 2008-2009. Totally, 6110 sand flies were collected using sticky papers and were subjected to molecular methods for detection of Leishmania parasite. Phlebotomus papatasi Scopoli was the common species in outdoor and indoor resting places. Polymerase chain reaction technique showed that 24 out of 218 P. papatasi (11%) and 4 out of 62 Phlebotomus caucasicus Marzinovskyi (6.5%) were positive for parasites Leishmania major Yakimoff and Schokhor. Twenty-one rodent reservoir hosts captured using Sherman traps were identified as Rhombomys opimus Lichtenstein (95%) and Meriones libycus Lichtenstein (5%). Microscopic investigation on blood smear of the animals for amastigote parasites revealed 8 (40%) rodents infected with R. opimus. L. major infection in these animals was then confirmed by polymerase chain reaction against internal transcribed spacer ribosomal DNA (rDNA) loci of the parasite followed by restriction fragment length polymorphism. Further, sequence analysis of 297 bp of ITS1-rDNA loci revealed the presence of L. major and Leishmania turanica in P. papatasi, and L. major in R. opimus. This is the first molecular report of L. major infection in both vectors (P. papatasi and P. caucasicus) and reservoir host (R. opimus) in this region. The results indicated that P. papatas was the primary vector of the disease and circulating the parasite between human and reservoirs, and P. caucasicus could be considered as a secondary vector. Further, our study showed that R. opimus is the most important host reservoir for maintenance of the parasite source in the area.

Rassi Y; Oshaghi MA; Azani SM; Abaie MR; Rafizadeh S; Mohebai M; Mohtarami F; Zeinali Mk

2011-02-01

312

Lutzomyia longipalpis naturally infected by Leishmania (L.) chagasi in Várzea Grande, Mato Grosso State, Brazil, an area of intense transmission of visceral leishmaniasis/ Lutzomyia longipalpis naturalmente infectado por Leishmania (L.) chagasi em Várzea Grande, Mato Grosso, Brasil, uma área de transmissão intensa de leishmaniose visceral  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A leishmaniose visceral americana (LVA) é causada por parasitos pertencentes ao gênero Leishmania (Trypanosomatidae) e transmitida ao homem através da picada de certas espécies de flebotomíneos, previamente infectados. Neste trabalho, investigamos o índice de infecção natural de Lutzomyia longipalpis, principal vetor da LVA no Brasil, em Várzea Grande, Estado do Mato Grosso. De julho de 2004 a junho de 2006, foram feitas capturas de flebotomíneos em áreas perid (more) omésticas utilizando armadilhas de luz CDC. Foram capturadas 420 espécimens de Lu. longipalpis. Quarenta e dois grupos, formados por 10 espécimens de Lu. longipalpis cada um, foram submetidos à extração de DNA genômico e amplificação por PCR (reação em cadeia da polimerase). DNA de Leishmania spp. foi detectado em 3 dos 42 grupos testados, resultando em um índice mínimo de infecção de 0,71%. A análise de polimorfismos de fragmentos de restrição (RFLP) indicou Leishmania (L.) chagasi como a espécie infectante nos grupos positivos. Abstract in english The American visceral leishmaniasis (AVL) is caused by parasites belonging to the genus Leishmania (Trypanosomatidae) and is transmitted to humans through the bite of certain species of infected phlebotomine sand flies. In this study, we investigated the natural infection ratio of Lutzomyia longipalpis, the main vector species of AVL in Brazil, in Várzea Grande, Mato Grosso State. Between July 2004 and June 2006, phlebotomine sand flies were captured in peridomestic area (more) s using CDC light-traps. Four hundred and twenty (420) specimens of Lu. longipalpis were captured. 42 pools, containing 10 specimens of Lu. longipalpis each, were used for genomic DNA extraction and PCR (polymerase chain reaction) amplification. Leishmania spp. DNA was detected in three out of the 42 pools tested, resulting in a minimal infection ratio of 0.71%. Restriction fragment length polymorphism (RFLP) analysis indicated that Leishmania (L.) chagasi was the infective agent in the positive pools.

Missawa, Nanci A.; Michalsky, Érika Monteiro; Fortes-Dias, Consuelo Latorre; Santos Dias, Edelberto

2010-12-01

313

Charaterization of Leishmania major Friedlin Telomeric Terminus  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Here we have characterized Leishmania major (Friedlin) telomeric terminus (the very end) using recombinants obtained by a vector-adaptor cloning protocol. As in L. donovani, the last nine nucleotides of L. major terminus are 5'-GGTTAGGGT-OH 3', differing from Trypanosoma cruzi and T. brucei terminus 5'GGGTTAGGG-OH 3', thus indicating that these sequences are genus specific. We have also made a comparative analysis between L. major and L. donovani telomere-associated seque (more) nces, and described a novel non-repeated telomeric associated sequence common to L. major low molecular weight chromosomal bands.

Chiurillo, Miguel Angel; Ramírez, José Luis

2002-04-01