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Papers by Helen Rodrigues Martins

Research paper thumbnail of Encapsulation of benznidazole in nanostructured lipid carriers and increased trypanocidal activity in a resistant Trypanosoma cruzi strain

Brazilian Journal of Pharmaceutical Sciences, 2023

Research paper thumbnail of In-house ELISA method to analyze anti-Trypanosoma cruzi IgG reactivity for differential diagnosis and evaluation of Chagas disease morbidity Método de ELISA in-house na análise da reatividade de IgG anti-Trypanosoma cruzi para o diagnóstico diferencial e avaliação da morbidade da doença de Chagas

Research paper thumbnail of Intestinal parasitosis and environmental contamination with helminths and protozoa in a Quilombola community of southeast Brazil

Revista Cubana de Medicina Tropical, 2018

Introduction: Intestinal parasitosis by helminths and protozoa is still today a global public hea... more Introduction: Intestinal parasitosis by helminths and protozoa is still today a global public health problem mainly affecting people living in conditions of social vulnerability, including rural communities. Objective: Describe human intestinal parasitosis and environmental contamination with helminths and protozoa in the Quilombola community of Quartel do Indaia (of African descent) in the State of Minas Gerais, Brazil. Methods: A cross-sectional study was conducted of stool and soil samples by spontaneous sedimentation, and of plant samples by centrifugation sedimentation, to detect intestinal helminths and protozoa. Water samples were analyzed for total and fecal coliforms. Results: Helminths and protozoa were found in 45.5 % of the people (n = 66). The species detected were Ascaris lumbricoides (18.2 %), Entamoeba coli (18.2 %), Endolimax nana (18.2 %), ancylostoma (6.1 %), Iodamoeba butschlii (4.6 %), Giardia duodenalis (3 %) and Trichuris trichiura (1.5 %). More than one speci...

Research paper thumbnail of Phytochemical screening and biological assays of ethanolic leaf extract of Senna rugosa

Rodriguésia, 2020

Senna rugosa (Fabaceae) is a common specie of the Brazilian territory, especially in the Cerrado ... more Senna rugosa (Fabaceae) is a common specie of the Brazilian territory, especially in the Cerrado biome. It is widely used in the popular medicine although not yet adequately investigated as to its phytoconstituents and pharmacological activities. In this study, the preliminary phytochemical analysis of ethanolic leaf extract of S. rugosa was performed and its cytotoxicity, antitumoral and antimicrobial activities (antibacterial, antifungal, anti-Trypanosoma and anti-Leishmania) were evaluated. The crude extract was analyzed in HPLC-DAD and fractions were also characterized using GC-MS and ESI-MS techniques. Results indicate phenolic compounds majority presence, including flavonol, anthraquinone and anthrones derivatives. Relative antimicrobial activities were detected against Staphylococcus aureus, Pseudomonas aeruginosa, Candida famata, Candida krusei and Candida tropicalis. As well as, a weak anti-trypanosomatids activity against M2269 strain and BH46 strain of Leishmania sp. A re...

Research paper thumbnail of Antimicrobial alumina nanobiostructures of disulfide- and triazole-linked peptides: Synthesis, characterization, membrane interactions and biological activity

Colloids and Surfaces B: Biointerfaces, 2019

Research paper thumbnail of Spatial distribution of triatomines in domiciles of an urban area of the Brazilian Southeast Region

Memórias do Instituto Oswaldo Cruz, 2016

Research paper thumbnail of Trypanosoma cruzi: blood parasitism kinetics and their correlation with heart parasitism intensity during long-term infection of Beagle dogs

Memórias do Instituto Oswaldo Cruz, 2008

Research paper thumbnail of In-house ELISA method to analyze anti-Trypanosoma cruzi IgG reactivity for differential diagnosis and evaluation of Chagas disease morbidity

Revista da Sociedade Brasileira de Medicina Tropical, 2012

INTRODUCTION: The goal was to develop an in-house serological method with high specificity and se... more INTRODUCTION: The goal was to develop an in-house serological method with high specificity and sensitivity for diagnosis and monitoring of Chagas disease morbidity. METHODS: With this purpose, the reactivities of anti-T. cruzi IgG and subclasses were tested in successive serum dilutions of patients from Berilo municipality, Jequitinhonha Valley, Minas Gerais, Brazil. The performance of the in-house ELISA was also evaluated in samples from other relevant infectious diseases, including HIV, hepatitis C (HCV), syphilis (SYP), visceral leishmaniasis (VL), and American tegumentary leishmaniasis (ATL), and noninfected controls (NI). Further analysis was performed to evaluate the applicability of this in-house methodology for monitoring Chagas disease morbidity into three groups of patients: indeterminate (IND), cardiac (CARD), and digestive/mixed (DIG/Mix), based on their clinical status. RESULTS: The analysis of total IgG reactivity at serum dilution 1:40 was an excellent approach to Cha...

Research paper thumbnail of Clinical and laboratory status of patients with chronic Chagas disease living in a vector-controlled area in Minas Gerais, Brazil, before and nine years after aetiological treatment

Memórias do Instituto Oswaldo Cruz, 2009

Research paper thumbnail of Effects of specific treatment on parasitological and histopathological parameters in mice infected with different Trypanosoma cruzi clonal genotypes

Journal of Antimicrobial Chemotherapy, 2004

Research paper thumbnail of Persistence of PCR-positive tissue in benznidazole-treated mice with negative blood parasitological and serological tests in dual infections with Trypanosoma cruzi stocks from different genotypes

Journal of Antimicrobial Chemotherapy, 2008

Research paper thumbnail of Trypanosoma cruzi: Treatment with the iron chelator desferrioxamine reduces parasitemia and mortality in experimentally infected mice

Experimental Parasitology, 2007

Research paper thumbnail of Trypanosoma cruzi: Immunoglobulin isotype profiles during the acute phase of canine experimental infection with metacyclic or blood trypomastigotes

Experimental Parasitology, 2008

Research paper thumbnail of Trypanosoma cruzi: Effect of benznidazole therapy combined with the iron chelator desferrioxamine in infected mice

Experimental Parasitology, 2008

Research paper thumbnail of Development of a label-free immunosensor based on surface plasmon resonance technique for the detection of anti-Leishmania infantum antibodies in canine serum

Biosensors and Bioelectronics, 2013

Research paper thumbnail of New insights into Trypanosoma cruzi genetic diversity, and its influence on parasite biology and clinical outcomes

Frontiers in immunology, Apr 9, 2024

Research paper thumbnail of Trypanosoma cruzi Discret Typing Units (TcII and TcVI) in samples of patients from two municipalities of the Jequitinhonha Valley, MG, Brazil, using two molecular typing strategies

Parasites & Vectors, 2015

Background: Trypanosoma cruzi is classified into six discrete taxonomic units (DTUs). For this cl... more Background: Trypanosoma cruzi is classified into six discrete taxonomic units (DTUs). For this classification, different biological markers and classification criteria have been used. The objective was to identify the genetic profile of T. cruzi samples isolated from patients of two municipalities of Jequitinhonha Valley, MG, Brazil. Methods: Molecular characterization was performed using two different criteria for T. cruzi typing to characterize 63 T. cruzi samples isolated from chronic Chagas disease patients. The characterizations followed two distinct methodologies. Additionally, the RAPD technique was used to evaluate the existence of genetic intragroup variability. Results: The first methodology identified 89 % of the samples as TcII, but it was not possible to define the genetic identity of seven isolates. The results obtained with the second methodology corroborated the classification as TcII of the same samples and defined the classification of the other seven as TcVI. RAPD analysis showed lower intra-group variability in TcII. Conclusions: The results confirmed the preliminary data obtained in other municipalities of the Jequitinhonha Valley, showing a predominance of TcII, similar to that verified in northeast/south axis of Brazil and the first detection of TcVI in the study region. The second protocol was more simple and reliable to identify samples of hybrid character.

Research paper thumbnail of Genetic modulation in Be-78 and Y Trypanosoma cruzi strains after long-term infection in Beagle dogs revealed by molecular markers

Infection, Genetics and Evolution, 2012

The genetic profile of Trypanosoma cruzi was evaluated in parasite populations isolated from Beag... more The genetic profile of Trypanosoma cruzi was evaluated in parasite populations isolated from Beagle dogs experimentally infected with Be-78 and Y strains that present distinct biological and genetic characteristics. Molecular characterization of the isolates obtained 30 days and 2 years after infection was carried out. For typing MLEE, sequence polymorphisms of the mitochondrial cytochrome oxidase subunit II gene (COII) and RAPD profiles were used. The profiles of MLEE were the same for the parental Be-78 strains as their respective isolates. However, changes of MLEE profile were observed in two T. cruzi isolates from dogs inoculated with Y strain. Changes in the mitochondrial DNA (COII) and RAPD profiles of the Y strain were also observed. The dendogram constructed by UPGMA with RAPD results indicated two major branches. Global data show that the genetic modulation in polyclonal strains during the long-term infection occurred and was strain-dependent. This study still suggests that each host (here each dog) harbors a determinate T. cruzi population that may change or be modulated throughout long-term infection. This might to hinder the observation of correlation between the genetics of T. cruzi and their biological properties and behavior in different host species due to the complexity of the parasite-host interaction in which probably the genetic background of both should be considered.

Research paper thumbnail of Encapsulation of benznidazole in nanostructured lipid carriers and increased trypanocidal activity in a resistant Trypanosoma cruzi strain

Brazilian Journal of Pharmaceutical Sciences, 2023

Research paper thumbnail of In-house ELISA method to analyze anti-Trypanosoma cruzi IgG reactivity for differential diagnosis and evaluation of Chagas disease morbidity Método de ELISA in-house na análise da reatividade de IgG anti-Trypanosoma cruzi para o diagnóstico diferencial e avaliação da morbidade da doença de Chagas

Research paper thumbnail of Intestinal parasitosis and environmental contamination with helminths and protozoa in a Quilombola community of southeast Brazil

Revista Cubana de Medicina Tropical, 2018

Introduction: Intestinal parasitosis by helminths and protozoa is still today a global public hea... more Introduction: Intestinal parasitosis by helminths and protozoa is still today a global public health problem mainly affecting people living in conditions of social vulnerability, including rural communities. Objective: Describe human intestinal parasitosis and environmental contamination with helminths and protozoa in the Quilombola community of Quartel do Indaia (of African descent) in the State of Minas Gerais, Brazil. Methods: A cross-sectional study was conducted of stool and soil samples by spontaneous sedimentation, and of plant samples by centrifugation sedimentation, to detect intestinal helminths and protozoa. Water samples were analyzed for total and fecal coliforms. Results: Helminths and protozoa were found in 45.5 % of the people (n = 66). The species detected were Ascaris lumbricoides (18.2 %), Entamoeba coli (18.2 %), Endolimax nana (18.2 %), ancylostoma (6.1 %), Iodamoeba butschlii (4.6 %), Giardia duodenalis (3 %) and Trichuris trichiura (1.5 %). More than one speci...

Research paper thumbnail of Phytochemical screening and biological assays of ethanolic leaf extract of Senna rugosa

Rodriguésia, 2020

Senna rugosa (Fabaceae) is a common specie of the Brazilian territory, especially in the Cerrado ... more Senna rugosa (Fabaceae) is a common specie of the Brazilian territory, especially in the Cerrado biome. It is widely used in the popular medicine although not yet adequately investigated as to its phytoconstituents and pharmacological activities. In this study, the preliminary phytochemical analysis of ethanolic leaf extract of S. rugosa was performed and its cytotoxicity, antitumoral and antimicrobial activities (antibacterial, antifungal, anti-Trypanosoma and anti-Leishmania) were evaluated. The crude extract was analyzed in HPLC-DAD and fractions were also characterized using GC-MS and ESI-MS techniques. Results indicate phenolic compounds majority presence, including flavonol, anthraquinone and anthrones derivatives. Relative antimicrobial activities were detected against Staphylococcus aureus, Pseudomonas aeruginosa, Candida famata, Candida krusei and Candida tropicalis. As well as, a weak anti-trypanosomatids activity against M2269 strain and BH46 strain of Leishmania sp. A re...

Research paper thumbnail of Antimicrobial alumina nanobiostructures of disulfide- and triazole-linked peptides: Synthesis, characterization, membrane interactions and biological activity

Colloids and Surfaces B: Biointerfaces, 2019

Research paper thumbnail of Spatial distribution of triatomines in domiciles of an urban area of the Brazilian Southeast Region

Memórias do Instituto Oswaldo Cruz, 2016

Research paper thumbnail of Trypanosoma cruzi: blood parasitism kinetics and their correlation with heart parasitism intensity during long-term infection of Beagle dogs

Memórias do Instituto Oswaldo Cruz, 2008

Research paper thumbnail of In-house ELISA method to analyze anti-Trypanosoma cruzi IgG reactivity for differential diagnosis and evaluation of Chagas disease morbidity

Revista da Sociedade Brasileira de Medicina Tropical, 2012

INTRODUCTION: The goal was to develop an in-house serological method with high specificity and se... more INTRODUCTION: The goal was to develop an in-house serological method with high specificity and sensitivity for diagnosis and monitoring of Chagas disease morbidity. METHODS: With this purpose, the reactivities of anti-T. cruzi IgG and subclasses were tested in successive serum dilutions of patients from Berilo municipality, Jequitinhonha Valley, Minas Gerais, Brazil. The performance of the in-house ELISA was also evaluated in samples from other relevant infectious diseases, including HIV, hepatitis C (HCV), syphilis (SYP), visceral leishmaniasis (VL), and American tegumentary leishmaniasis (ATL), and noninfected controls (NI). Further analysis was performed to evaluate the applicability of this in-house methodology for monitoring Chagas disease morbidity into three groups of patients: indeterminate (IND), cardiac (CARD), and digestive/mixed (DIG/Mix), based on their clinical status. RESULTS: The analysis of total IgG reactivity at serum dilution 1:40 was an excellent approach to Cha...

Research paper thumbnail of Clinical and laboratory status of patients with chronic Chagas disease living in a vector-controlled area in Minas Gerais, Brazil, before and nine years after aetiological treatment

Memórias do Instituto Oswaldo Cruz, 2009

Research paper thumbnail of Effects of specific treatment on parasitological and histopathological parameters in mice infected with different Trypanosoma cruzi clonal genotypes

Journal of Antimicrobial Chemotherapy, 2004

Research paper thumbnail of Persistence of PCR-positive tissue in benznidazole-treated mice with negative blood parasitological and serological tests in dual infections with Trypanosoma cruzi stocks from different genotypes

Journal of Antimicrobial Chemotherapy, 2008

Research paper thumbnail of Trypanosoma cruzi: Treatment with the iron chelator desferrioxamine reduces parasitemia and mortality in experimentally infected mice

Experimental Parasitology, 2007

Research paper thumbnail of Trypanosoma cruzi: Immunoglobulin isotype profiles during the acute phase of canine experimental infection with metacyclic or blood trypomastigotes

Experimental Parasitology, 2008

Research paper thumbnail of Trypanosoma cruzi: Effect of benznidazole therapy combined with the iron chelator desferrioxamine in infected mice

Experimental Parasitology, 2008

Research paper thumbnail of Development of a label-free immunosensor based on surface plasmon resonance technique for the detection of anti-Leishmania infantum antibodies in canine serum

Biosensors and Bioelectronics, 2013

Research paper thumbnail of New insights into Trypanosoma cruzi genetic diversity, and its influence on parasite biology and clinical outcomes

Frontiers in immunology, Apr 9, 2024

Research paper thumbnail of Trypanosoma cruzi Discret Typing Units (TcII and TcVI) in samples of patients from two municipalities of the Jequitinhonha Valley, MG, Brazil, using two molecular typing strategies

Parasites & Vectors, 2015

Background: Trypanosoma cruzi is classified into six discrete taxonomic units (DTUs). For this cl... more Background: Trypanosoma cruzi is classified into six discrete taxonomic units (DTUs). For this classification, different biological markers and classification criteria have been used. The objective was to identify the genetic profile of T. cruzi samples isolated from patients of two municipalities of Jequitinhonha Valley, MG, Brazil. Methods: Molecular characterization was performed using two different criteria for T. cruzi typing to characterize 63 T. cruzi samples isolated from chronic Chagas disease patients. The characterizations followed two distinct methodologies. Additionally, the RAPD technique was used to evaluate the existence of genetic intragroup variability. Results: The first methodology identified 89 % of the samples as TcII, but it was not possible to define the genetic identity of seven isolates. The results obtained with the second methodology corroborated the classification as TcII of the same samples and defined the classification of the other seven as TcVI. RAPD analysis showed lower intra-group variability in TcII. Conclusions: The results confirmed the preliminary data obtained in other municipalities of the Jequitinhonha Valley, showing a predominance of TcII, similar to that verified in northeast/south axis of Brazil and the first detection of TcVI in the study region. The second protocol was more simple and reliable to identify samples of hybrid character.

Research paper thumbnail of Genetic modulation in Be-78 and Y Trypanosoma cruzi strains after long-term infection in Beagle dogs revealed by molecular markers

Infection, Genetics and Evolution, 2012

The genetic profile of Trypanosoma cruzi was evaluated in parasite populations isolated from Beag... more The genetic profile of Trypanosoma cruzi was evaluated in parasite populations isolated from Beagle dogs experimentally infected with Be-78 and Y strains that present distinct biological and genetic characteristics. Molecular characterization of the isolates obtained 30 days and 2 years after infection was carried out. For typing MLEE, sequence polymorphisms of the mitochondrial cytochrome oxidase subunit II gene (COII) and RAPD profiles were used. The profiles of MLEE were the same for the parental Be-78 strains as their respective isolates. However, changes of MLEE profile were observed in two T. cruzi isolates from dogs inoculated with Y strain. Changes in the mitochondrial DNA (COII) and RAPD profiles of the Y strain were also observed. The dendogram constructed by UPGMA with RAPD results indicated two major branches. Global data show that the genetic modulation in polyclonal strains during the long-term infection occurred and was strain-dependent. This study still suggests that each host (here each dog) harbors a determinate T. cruzi population that may change or be modulated throughout long-term infection. This might to hinder the observation of correlation between the genetics of T. cruzi and their biological properties and behavior in different host species due to the complexity of the parasite-host interaction in which probably the genetic background of both should be considered.