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Search Results: 1 - 10 of 418744 matches for " Antonia M Ramos;Grimaldi Jr "
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Characterization of Endotrypanum (Kinetoplastida: Trypanosomatidae), a Unique Parasite Infecting the Neotropical Tree Sloths (Edentata)
Franco, Antonia M Ramos;Grimaldi Jr, Gabriel;
Memórias do Instituto Oswaldo Cruz , 1999, DOI: 10.1590/S0074-02761999000200026
Abstract: this article reviews current concepts of the biology of endotrypanum spp. data summarized here on parasite classification and taxonomic divergence found among these haemoflagellates come from our studies of molecular characterization of endotrypanum stocks (representing an heterogenous population of reference strains and isolates from the brazilian amazon region) and from scientific literature. using numerical zymotaxonomy we have demonstrated genetic diversity among these parasites. the molecular trees obtained revealed that there are, at least, three groups (distinct species?) of endotrypanum, which are distributed in central and south america. in concordance with this classification of the parasites there are further newer molecular data obtained using distinct markers. moreover, comparative studies (based on the molecular genetics of the organisms) have shown the phylogenetic relationships between some endotrypanum and related kinetoplastid lineages.
Characterization of Endotrypanum (Kinetoplastida: Trypanosomatidae), a Unique Parasite Infecting the Neotropical Tree Sloths (Edentata)
Franco Antonia M Ramos,Grimaldi Jr Gabriel
Memórias do Instituto Oswaldo Cruz , 1999,
Abstract: This article reviews current concepts of the biology of Endotrypanum spp. Data summarized here on parasite classification and taxonomic divergence found among these haemoflagellates come from our studies of molecular characterization of Endotrypanum stocks (representing an heterogenous population of reference strains and isolates from the Brazilian Amazon region) and from scientific literature. Using numerical zymotaxonomy we have demonstrated genetic diversity among these parasites. The molecular trees obtained revealed that there are, at least, three groups (distinct species?) of Endotrypanum, which are distributed in Central and South America. In concordance with this classification of the parasites there are further newer molecular data obtained using distinct markers. Moreover, comparative studies (based on the molecular genetics of the organisms) have shown the phylogenetic relationships between some Endotrypanum and related kinetoplastid lineages.
Minicircle kDNA microheterogeneity in Endotrypanum indicate diversity within this genus
Franco, Antonia MR;Machado, Gérzia MC;Moreira, Célia FS;Grimaldi Jr, Gabriel;
Memórias do Instituto Oswaldo Cruz , 2000, DOI: 10.1590/S0074-02762000000200009
Abstract: a comparison of kdna restriction-endonuclease fragment patterns from strains representing selected endotrypanum zymodemes was done by schizodeme analysis. as the degree of heterogeneity within mini-circles varied among species or strains of endotrypanum, the fingerprint obtained with each of the restriction enzymes was unique for each of these parasites. the data have revealed that this trypanosomatid genus is much more complex than it was originally thought to be.
Minicircle kDNA microheterogeneity in Endotrypanum indicate diversity within this genus
Franco Antonia MR,Machado Gérzia MC,Moreira Célia FS,Grimaldi Jr Gabriel
Memórias do Instituto Oswaldo Cruz , 2000,
Abstract: A comparison of kDNA restriction-endonuclease fragment patterns from strains representing selected Endotrypanum zymodemes was done by schizodeme analysis. As the degree of heterogeneity within mini-circles varied among species or strains of Endotrypanum, the fingerprint obtained with each of the restriction enzymes was unique for each of these parasites. The data have revealed that this trypanosomatid genus is much more complex than it was originally thought to be.
Response to Heterologous Leishmanins in Cutaneous Leishmaniasis in Nigeria: Discovery of a New Focus
Agwale, Simon M;Duhlinska, Dockha D;Grimaldi Jr, Gabriel;
Memórias do Instituto Oswaldo Cruz , 1998, DOI: 10.1590/S0074-02761998000100005
Abstract: a pilot study was undertaken to preliminary illustrate the leishmanin skin test (lst) positivity to distinct antigen preparations (derived from promastigote of either leishmania major or l. amazonensis, or pooled l. mexicana, l. amazonensis and l. guyanensis) in cutaneous leishmaniasis (cl) patients and healthy subjects living in two endemic foci in nigeria. the study was designed to provide insights into whether cross-species leishmanin, such as that prepared from new world leishmania could be useful to detect cases of old world leishmanial infection and to compare the results with lst using l. major-derived leishmanin. the overall lst positivity in individuals from keana tested with the cross-species leishmanin was 28.7% (27/94), while the positivity rate in the subjects from kanana tested with the same leishmanin was 54.5% (6/11). lower positivity values were obtained when l. major (12.5%; 11/88) or l. amazonensis (15.8%; 9/57) was tested as antigen in grossly comparable populations. moreover, the pooled leishmanin identified most of the subjects (13/14; 92.9%) with active or healed cl, and the maximum reaction sizes were found among positive subjects in this group. no healthy controls (10 total) showed specific dth response. the lst was useful for assessing the prevalence of subclinical infection and for measuring cl transmission over time. we report for the first time the occurrence of cl in kanana village of langtang south local government area of plateau state
Response to Heterologous Leishmanins in Cutaneous Leishmaniasis in Nigeria: Discovery of a New Focus
Agwale Simon M,Duhlinska Dockha D,Grimaldi Jr Gabriel
Memórias do Instituto Oswaldo Cruz , 1998,
Abstract: A pilot study was undertaken to preliminary illustrate the leishmanin skin test (LST) positivity to distinct antigen preparations (derived from promastigote of either Leishmania major or L. amazonensis, or pooled L. mexicana, L. amazonensis and L. guyanensis) in cutaneous leishmaniasis (CL) patients and healthy subjects living in two endemic foci in Nigeria. The study was designed to provide insights into whether cross-species leishmanin, such as that prepared from New World Leishmania could be useful to detect cases of Old World leishmanial infection and to compare the results with LST using L. major-derived leishmanin. The overall LST positivity in individuals from Keana tested with the cross-species leishmanin was 28.7% (27/94), while the positivity rate in the subjects from Kanana tested with the same leishmanin was 54.5% (6/11). Lower positivity values were obtained when L. major (12.5%; 11/88) or L. amazonensis (15.8%; 9/57) was tested as antigen in grossly comparable populations. Moreover, the pooled leishmanin identified most of the subjects (13/14; 92.9%) with active or healed CL, and the maximum reaction sizes were found among positive subjects in this group. No healthy controls (10 total) showed specific DTH response. The LST was useful for assessing the prevalence of subclinical infection and for measuring CL transmission over time. We report for the first time the occurrence of CL in Kanana village of Langtang South local government area of Plateau State
The utility of rhesus monkey (Macaca mulatta) and other non-human primate models for preclinical testing of Leishmania candidate vaccines
Grimaldi Jr, Gabriel;
Memórias do Instituto Oswaldo Cruz , 2008, DOI: 10.1590/S0074-02762008000700002
Abstract: leishmaniasis causes significant morbidity and mortality, constituting an important global health problem for which there are few effective drugs. given the urgent need to identify a safe and effective leishmania vaccine to help prevent the two million new cases of human leishmaniasis worldwide each year, all reasonable efforts to achieve this goal should be made. this includes the use of animal models that are as close to leishmanial infection in humans as is practical and feasible. old world monkey species (macaques, baboons, mandrills etc.) have the closest evolutionary relatedness to humans among the approachable animal models. the asian rhesus macaques (macaca mulatta) are quite susceptible to leishmanial infection, develop a human-like disease, exhibit antibodies to leishmania and parasite-specific t-cell mediated immune responses both in vivo and in vitro, and can be protected effectively by vaccination. results from macaque vaccine studies could also prove useful in guiding the design of human vaccine trials. this review summarizes our current knowledge on this topic and proposes potential approaches that may result in the more effective use of the macaque model to maximize its potential to help the development of an effective vaccine for human leishmaniasis.
High-Throughput Analysis of Synthetic Peptides for the Immunodiagnosis of Canine Visceral Leishmaniasis
Angélica R. Faria,Míriam M. Costa,Mário S. Giusta,Gabriel Grimaldi Jr.,Marcus L. O. Penido,Ricardo T. Gazzinelli,Hélida M. Andrade
PLOS Neglected Tropical Diseases , 2011, DOI: 10.1371/journal.pntd.0001310
Abstract: Background Visceral leishmaniasis is the most severe form of leishmaniasis. Approximately 20% of zoonotic human visceral leishmaniasis worldwide is caused by Leishmania infantum, which is also known as Leishmania chagasi in Latin America, and disease incidence is increasing in urban and peri-urban areas of the tropics. In this form of disease, dogs are the main reservoirs. Diagnostic methods used to identify Leishmania infected animals are not able to detect all of the infected ones, which can compromise the effectiveness of disease control. Therefore, to contribute to the improvement of diagnostic methods for canine visceral leishmaniasis (CVL), we aimed to identify and test novel antigens using high-throughput analysis. Methodology/Principal Findings Immunodominant proteins from L. infantum were mapped in silico to predict B cell epitopes, and the 360 predicted peptides were synthesized on cellulose membranes. Immunoassays were used to select the most reactive peptides, which were then investigated with canine sera. Next, the 10 most reactive peptides were synthesized using solid phase peptide synthesis protocol and tested using ELISA. The sensitivity and specificity of these peptides were also compared to the EIE-LVC Bio-Manguinhos kit, which is recommended by the Brazilian Ministry of Health for use in leishmaniasis control programs. The sensitivity and specificity of the selected synthesized peptides was as high as 88.70% and 95.00%, respectively, whereas the EIE-LVC kit had a sensitivity of 13.08% and 100.00% of specificity. Although the tests based on synthetic peptides were able to diagnose up to 94.80% of asymptomatic dogs with leishmaniasis, the EIE-LVC kit failed to detect the disease in any of the infected asymptomatic dogs. Conclusions/Significance Our study shows that ELISA using synthetic peptides is a technique with great potential for diagnosing CVL; furthermore, the use of these peptides in other diagnostic methodologies, such as immunochromatographic tests, could be beneficial to CVL control programs.
Atypical Mucocutaneous Leishmaniasis Caused by Leishmania braziliensis in an Acquired Immunodeficiency Syndrome Patient: T-cell Responses and Remission of Lesions Associated with Antigen Immunotherapy
Da-Cruz, Alda M;Filgueiras, Danilo V;Coutinho, Ziadir;Mayrink, Wilson;Grimaldi Jr, Gabriel;De Luca, Paula M;Mendon?a, Sergio CF;Coutinho, Sergio G;
Memórias do Instituto Oswaldo Cruz , 1999, DOI: 10.1590/S0074-02761999000400020
Abstract: an atypical case of acquired immunodeficiency syndrome-associated mucocutaneous lesions due to leishmania braziliensis is described. many vacuolated macrophages laden with amastigote forms of the parasite were found in the lesions. leishmanin skin test and serology for leishmaniasis were both negative. the patient was resistant to therapy with conventional drugs (antimonial and amphotericin b). interestingly, remission of lesions was achieved after an alternative combined therapy of antimonial associated with immunotherapy (whole promastigote antigens). peripheral blood mononuclear cells were separated and stimulated in vitro with leishmania antigens to test the lymphoproliferative responses (lpr). before the combined immunochemotherapy, the lpr to leishmanial antigens was negligible (stimulation index - si=1.4). after the first course of combined therapy it became positive (si=4.17). the antigen responding cells were predominantly t-cells (47.5%) most of them with cd8+ phenotype (33%). very low cd4+ cells (2.2%) percentages were detected. the increased t-cell responsiveness to leishmanial antigens after combined therapy was accompanied by interferon-g (ifn-g) production as observed in the cell culture supernatants. in this patient, healing of the leishmaniasis lesions was associated with the induction of a specific t-cell immune response, characterized by the production of ifn-g and the predominance of the cd8+ phenotype among the leishmania-reactive t-cells.
First World Congress on Leishmaniasis-World Leish1
Franco Antonia Maria Ramos
Memórias do Instituto Oswaldo Cruz , 1997,
Abstract:
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