Gentilda Takeda - Academia.edu (original) (raw)

Uploads

Papers by Gentilda Takeda

Research paper thumbnail of STUDIES ON THE PROCEDURE OF MUTATION BREEDING WITH SIX-ROWED BARLEY. I. THE METHODS OF PROCEDURE IN Xâ AND Xâ GENERATIONS

Research paper thumbnail of Trypanosoma (Megatrypanum shawi n. sp., um parasita de capivara, Hydrochaeris hydrochaeris (Linnaeus, 1766) (Rodentia: hydrochoeridae)

Semina: Ciências Agrárias, 1987

Research paper thumbnail of Ocorrência de tripanossomos em bovinos na região de Campo Grande, Mato Grosso do Sul, Brasil

Revista da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo, 1983

Research paper thumbnail of Randomly amplified polymorphic DNA analysis of Trypanosoma rangeli and allied species from human, monkeys and other sylvatic mammals of the Brazilian Amazon disclosed a new group and a species-specific marker

Research paper thumbnail of Genetic relatedness among Trypanosoma evansi stocks by random amplification of polymorphic DNA and evaluation of a synapomorphic DNA fragment for species-specific diagnosis

International Journal for Parasitology, 2002

In this study we employed randomly amplified polymorphic DNA patterns to assess the genetic relat... more In this study we employed randomly amplified polymorphic DNA patterns to assess the genetic relatedness among 14 Brazilian Trypanosoma evansi stocks from domestic and wild hosts, which are known to differ in biological characteristics. These akinetoplastic stocks were compared with one another, to three Old World (Ethiopia, China and Philippines) dyskinetoplastic stocks of T. evansi, and also with Trypanosoma equiperdum, Trypanosoma brucei brucei, Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense. Randomly amplified polymorphic DNA analysis showed limited heterogeneity in T. evansi stocks from different hosts and geographical regions of the world, or in other species of the subgenus Trypanozoon. However, minor variations generated random amplification of polymorphic DNA analysis disclosed a pattern consisting of a unique synapomorphic DNA fragment (termed Te664) for the T. evansi cluster that was not detected in any other trypanosome species investigated. Pulsed field gel electrophoresis analysis demonstrated that the Te664 fragment is a repetitive sequence, dispersed in intermediate and minichromosomes of T. evansi. Based on this sequence, we developed a conventional PCR assay for the detection of T. evansi using crude preparations of blood collected either on glass slides or on filter paper as template DNA. Our results showed that this assay may be useful as a diagnostic tool for field-epidemiological studies of T. evansi.

Research paper thumbnail of Trypanosoma rangeli isolates of bats from Central Brazil: Genotyping and phylogenetic analysis enable description of a new lineage using spliced-leader gene sequences

Acta Tropica, 2009

Trypanosoma rangeli infects several mammalian orders but has never confidently been described in ... more Trypanosoma rangeli infects several mammalian orders but has never confidently been described in Chiroptera, which are commonly parasitized by many trypanosome species. Here, we described trypanosomes from bats captured in Central Brazil identified as T. rangeli, T. dionisii, T. cruzimarinkellei and T. cruzi. Two isolates, Tra643 from Platyrrhinus lineatus and Tra1719 from Artibeus planirostris were identified as T. rangeli by morphological, biological and molecular methods, and confirmed by phylogenetic analyses. Analysis using SSU rDNA sequences clustered these bat trypanosomes together with T. rangeli from other hosts, and separated them from other trypanosomes from bats. Genotyping based on length and sequence polymorphism of PCR-amplified intergenic spliced-leader gene sequences assigned Tra1719 to the lineage A whereas Tra643 was shown to be a new genotype and was assigned to the new lineage E. To our knowledge, these two isolates are the earliest T. rangeli from bats and the first isolates from Central Brazil molecularly characterized. Rhodnius stali captured for this study was found infected by T. rangeli and T. cruzi.

Research paper thumbnail of Ação de raios gama sobre formas sanguícolas de Trypanosoma cruzi: estudo experimental em camundongos

Revista do Instituto de Medicina Tropical de São Paulo, 1986

Page 1. Rev. Inst. Med. trop. São Paulo 28(1}:15-18, janeiro-fevereiro. 1986 AÇÃO DE RAIOS GAMA S... more Page 1. Rev. Inst. Med. trop. São Paulo 28(1}:15-18, janeiro-fevereiro. 1986 AÇÃO DE RAIOS GAMA SOBRE FORMAS SANGUÍCOLAS DE TRYPANOSOMA CRUZ). ESTUDO EXPERIMENTAL EM CAMUNDONGOS Gentilità К. ...

Research paper thumbnail of MOLECULAR AND MORPHOLOGICAL STUDIES OF BRAZILIAN TRYPANOSOMA EVANSI STOCKS: THE TOTAL ABSENCE OF KDNA IN TRYPANOSOMES FROM BOTH LABORATORY STOCKS AND NATURALLY INFECTED DOMESTIC AND WILD MAMMALS

Journal of Parasitology, 2000

The kinetoplast DNA (kDNA) minicircle molecules of 14 Brazilian stocks of Trypanosoma evansi were... more The kinetoplast DNA (kDNA) minicircle molecules of 14 Brazilian stocks of Trypanosoma evansi were studied by morphological approaches (Giemsa and 4'-6'-diamidino-2-phenylindole staining and transmission electron microscopy) and molecular approaches (probing with an oligonucleotide complementary to the minicircle origin of replication and polymerase chain reaction amplification of a minicircle sequence). All methods indicated the absence of both a typical kinetoplast and kDNA minicircles, even in a very small number of parasites of a single stock or in small numbers of copies of molecules per cell. We did not detect any altered kDNA molecules. There were no kDNA molecules in either old or new stocks of T. evansi maintained by successive passages in mice. Similarly, no kDNA minicircles were detected in trypanosomes in blood smears from naturally infected domestic and wild animals. Thus, the total absence of kDNA in Brazilian stocks of T. evansi from both domestic and wild mammals is probably the natural state of Brazilian T. evansi.

Research paper thumbnail of Trypanosoma vivax: Characterization of the Spliced-Leader Gene of a Brazilian Stock and Species-Specific Detection by PCR Amplification of an Intergenic Spacer Sequence

Experimental Parasitology, 2001

investigation of trypanosomes G. A., and Teixeira, M. M. G. 2001. Trypanosoma vivax: Characteriza... more investigation of trypanosomes G. A., and Teixeira, M. M. G. 2001. Trypanosoma vivax: Characterization of the spliced-leader gene of a Brazilian stock and species-specific

Research paper thumbnail of STUDIES ON THE PROCEDURE OF MUTATION BREEDING WITH SIX-ROWED BARLEY. I. THE METHODS OF PROCEDURE IN Xâ AND Xâ GENERATIONS

Research paper thumbnail of Trypanosoma (Megatrypanum shawi n. sp., um parasita de capivara, Hydrochaeris hydrochaeris (Linnaeus, 1766) (Rodentia: hydrochoeridae)

Semina: Ciências Agrárias, 1987

Research paper thumbnail of Ocorrência de tripanossomos em bovinos na região de Campo Grande, Mato Grosso do Sul, Brasil

Revista da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo, 1983

Research paper thumbnail of Randomly amplified polymorphic DNA analysis of Trypanosoma rangeli and allied species from human, monkeys and other sylvatic mammals of the Brazilian Amazon disclosed a new group and a species-specific marker

Research paper thumbnail of Genetic relatedness among Trypanosoma evansi stocks by random amplification of polymorphic DNA and evaluation of a synapomorphic DNA fragment for species-specific diagnosis

International Journal for Parasitology, 2002

In this study we employed randomly amplified polymorphic DNA patterns to assess the genetic relat... more In this study we employed randomly amplified polymorphic DNA patterns to assess the genetic relatedness among 14 Brazilian Trypanosoma evansi stocks from domestic and wild hosts, which are known to differ in biological characteristics. These akinetoplastic stocks were compared with one another, to three Old World (Ethiopia, China and Philippines) dyskinetoplastic stocks of T. evansi, and also with Trypanosoma equiperdum, Trypanosoma brucei brucei, Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense. Randomly amplified polymorphic DNA analysis showed limited heterogeneity in T. evansi stocks from different hosts and geographical regions of the world, or in other species of the subgenus Trypanozoon. However, minor variations generated random amplification of polymorphic DNA analysis disclosed a pattern consisting of a unique synapomorphic DNA fragment (termed Te664) for the T. evansi cluster that was not detected in any other trypanosome species investigated. Pulsed field gel electrophoresis analysis demonstrated that the Te664 fragment is a repetitive sequence, dispersed in intermediate and minichromosomes of T. evansi. Based on this sequence, we developed a conventional PCR assay for the detection of T. evansi using crude preparations of blood collected either on glass slides or on filter paper as template DNA. Our results showed that this assay may be useful as a diagnostic tool for field-epidemiological studies of T. evansi.

Research paper thumbnail of Trypanosoma rangeli isolates of bats from Central Brazil: Genotyping and phylogenetic analysis enable description of a new lineage using spliced-leader gene sequences

Acta Tropica, 2009

Trypanosoma rangeli infects several mammalian orders but has never confidently been described in ... more Trypanosoma rangeli infects several mammalian orders but has never confidently been described in Chiroptera, which are commonly parasitized by many trypanosome species. Here, we described trypanosomes from bats captured in Central Brazil identified as T. rangeli, T. dionisii, T. cruzimarinkellei and T. cruzi. Two isolates, Tra643 from Platyrrhinus lineatus and Tra1719 from Artibeus planirostris were identified as T. rangeli by morphological, biological and molecular methods, and confirmed by phylogenetic analyses. Analysis using SSU rDNA sequences clustered these bat trypanosomes together with T. rangeli from other hosts, and separated them from other trypanosomes from bats. Genotyping based on length and sequence polymorphism of PCR-amplified intergenic spliced-leader gene sequences assigned Tra1719 to the lineage A whereas Tra643 was shown to be a new genotype and was assigned to the new lineage E. To our knowledge, these two isolates are the earliest T. rangeli from bats and the first isolates from Central Brazil molecularly characterized. Rhodnius stali captured for this study was found infected by T. rangeli and T. cruzi.

Research paper thumbnail of Ação de raios gama sobre formas sanguícolas de Trypanosoma cruzi: estudo experimental em camundongos

Revista do Instituto de Medicina Tropical de São Paulo, 1986

Page 1. Rev. Inst. Med. trop. São Paulo 28(1}:15-18, janeiro-fevereiro. 1986 AÇÃO DE RAIOS GAMA S... more Page 1. Rev. Inst. Med. trop. São Paulo 28(1}:15-18, janeiro-fevereiro. 1986 AÇÃO DE RAIOS GAMA SOBRE FORMAS SANGUÍCOLAS DE TRYPANOSOMA CRUZ). ESTUDO EXPERIMENTAL EM CAMUNDONGOS Gentilità К. ...

Research paper thumbnail of MOLECULAR AND MORPHOLOGICAL STUDIES OF BRAZILIAN TRYPANOSOMA EVANSI STOCKS: THE TOTAL ABSENCE OF KDNA IN TRYPANOSOMES FROM BOTH LABORATORY STOCKS AND NATURALLY INFECTED DOMESTIC AND WILD MAMMALS

Journal of Parasitology, 2000

The kinetoplast DNA (kDNA) minicircle molecules of 14 Brazilian stocks of Trypanosoma evansi were... more The kinetoplast DNA (kDNA) minicircle molecules of 14 Brazilian stocks of Trypanosoma evansi were studied by morphological approaches (Giemsa and 4'-6'-diamidino-2-phenylindole staining and transmission electron microscopy) and molecular approaches (probing with an oligonucleotide complementary to the minicircle origin of replication and polymerase chain reaction amplification of a minicircle sequence). All methods indicated the absence of both a typical kinetoplast and kDNA minicircles, even in a very small number of parasites of a single stock or in small numbers of copies of molecules per cell. We did not detect any altered kDNA molecules. There were no kDNA molecules in either old or new stocks of T. evansi maintained by successive passages in mice. Similarly, no kDNA minicircles were detected in trypanosomes in blood smears from naturally infected domestic and wild animals. Thus, the total absence of kDNA in Brazilian stocks of T. evansi from both domestic and wild mammals is probably the natural state of Brazilian T. evansi.

Research paper thumbnail of Trypanosoma vivax: Characterization of the Spliced-Leader Gene of a Brazilian Stock and Species-Specific Detection by PCR Amplification of an Intergenic Spacer Sequence

Experimental Parasitology, 2001

investigation of trypanosomes G. A., and Teixeira, M. M. G. 2001. Trypanosoma vivax: Characteriza... more investigation of trypanosomes G. A., and Teixeira, M. M. G. 2001. Trypanosoma vivax: Characterization of the spliced-leader gene of a Brazilian stock and species-specific