Publications by authors named "Fernanda Madeira"

Background: Vectorial transmission through hematophagous triatomine insects remains the primary mode of Chagas Disease contagion. These insects have become increasingly common in urban environments. Therefore, this study aimed to report an encounter of triatomines with trypanosomatid infection in a vertical residential condominium in Rio Branco, the capital of the state of Acre, in the western Brazilian Amazon.

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Chagas disease affects about eight million people. In view of the issues related to the influence of anthropogenic changes in the dynamics of the distribution and reproductive interaction of triatomines, we performed experimental crosses between species of the Rhodniini tribe in order to evaluate interspecific reproductive interactions and hybrid production capacity. Reciprocal crossing experiments were conducted among , , , , ; × and × .

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Background: Triatomines infest atypical public spaces in the Western Amazon.

Methods: Frequent visitors to these spaces captured the insects in the state of Acre, Brazil (Rio Branco and Cruzeiro do Sul).

Results: Six insects were found in a penitentiary, a church, a school, a university, a hospital, and a health center.

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Several cytogenetic studies have already been performed in Triatominae, such that different karyotypes could be characterized (ranging from 2n = 21 to 25 chromosomes), being the changes in the number of chromosomes related mainly to fusion and fission events. These changes have been associated with reproductive isolation and speciation events in other insect groups. Thus, we evaluated whether different karyotypes could act in the reproductive isolation of triatomines and we analyzed how the events of karyotypic evolution occurred along the diversification of these vectors.

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Article Synopsis
  • * The female genitalia of the hybrids displayed traits from both parent species, and cytogenetic analyses showed normal chromosome structures.
  • * Molecular studies linked the hybrids to both parent species through specific genetic markers, revealing similar feeding and defecation patterns as their parents.
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  • The geniculatus clade includes several species of triatomine bugs, some of which have been studied for their role in transmitting Chagas disease, but no natural hybrids have been previously documented among these species.
  • Experimental crossings between species within the megistus and lignarius groups were performed to assess reproductive compatibility; results showed no egg hatching, indicating prezygotic barriers and confirming specific distinctions among the species.
  • The findings suggest that while hybridization is possible in other triatomine groups, the geniculatus clade displays prezygotic barriers that prevent hybrid formation, suggesting its significance for evolutionary studies in this area.
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Background: Triatoma tibiamaculata is a species distributed in ten Brazilian states which has epidemiological importance as it has already been found infecting household areas. The taxonomy of this triatomine has been quite unstable: it was initially described as Eutriatoma tibiamaculata. Later, the species was transferred from the genus Eutriatoma to Triatoma.

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Article Synopsis
  • The study demonstrated that despite morphological similarities, distinct genetic and reproductive barriers exist between the species, confirming their separate identities.
  • Experimental crossbreeding between these species showed no hybridization, indicating prezygotic reproductive isolation.
  • The findings suggest that one species is the most evolved member of the complex, rather than just a chromatic variant of another.
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Background: Triatoma sordida is one of the main Chagas disease vectors in Brazil. In addition to Brazil, this species has already been reported in Bolivia, Argentina, Paraguay, and Uruguay. It is hypothesized that the insects currently identified as T.

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Triatomines are hematophagous insects of great epidemiological importance, since they are vectors of the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease. Triatoma brasiliensis complex is a monophyletic group formed by two subspecies and six species: T. b.

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Article Synopsis
  • The taxonomy of the Meccus genus has changed multiple times since its first description in 1835, with recent studies supporting its synonymy with the Triatoma genus based on genetic evidence.
  • Natural hybridization among related species within the T. phyllosoma subcomplex has been confirmed, showing the potential for viable offspring across different species.
  • Experimental crosses between T. longipennis and T. mopan produced viable hybrids, indicating reproductive compatibility and supporting the reevaluation of species classification within the Triatominae subfamily.
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Introduction: Triatomines are insect vectors of Trypanosoma cruzi, the etiological agent of Chagas disease.

Methods: Triatomines were collected from households and by dissecting palm trees in the peri-urban areas of Cruzeiro do Sul (Acre); they were identified using a specific key and via genital analyses. Trypanosomatid infection was determined through microscopy and polymerase chain reaction.

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Article Synopsis
  • There are 156 species in the subfamily Triatominae, all potential vectors for Chagas disease, classified into 18 genera and five tribes, with Triatoma being a paraphyletic group.
  • The Triatoma brasiliensis complex, a monophyletic group, includes eight species, and experimental crosses among these species have been conducted to explore systematic and evolutionary questions.
  • The study found that hybrids displayed varying segregation patterns of phenotypic traits, emphasizing the need for integrative taxonomy to accurately identify Chagas disease vectors amid potential natural hybridization.
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Chagas disease is the most prevalent neglected tropical disease in the Americas and makes an important contribution to morbidity and mortality rates in countries where it is endemic since 30 to 40% of patients develop cardiac diseases, gastrointestinal disorders, or both. In this paper, a new species of the genus is described based on specimens collected in the Department San Miguel, Province of Corrientes, Argentina. sp.

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Introduction: Triatomines are hematophagous insects that are important to public health since they are the vectors of American Trypanosomiasis. The objective of this study was to describe the occurrence of triatomines in homes in Cruzeiro do Sul, Acre, Brazil.

Methods: The specimens were collected by an active search inside homes and also by a passive search by the residents.

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The etiological agent of American trypanosomiasis is the protozoan Trypanosoma cruzi , typically transmitted by triatomines. The aim of this study was to investigate the triatomine fauna and trypanosomiasis infections in Acre State , Western Brazilian Amazon. Insect collection was performed by dissecting palm trees and installing traps.

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Article Synopsis
  • Triatoma sordida is a prevalent species in Brazil's peridomestic environments, known for its adaptability to various habitats and food sources.
  • This species has a tendency to invade homes and create multiple colonies, making it a priority for pest control efforts in Brazil.
  • Genetic analysis shows that all Brazilian populations have low genetic variability but high haplotypic diversity, which is crucial for understanding their biology and guiding effective vector control strategies.
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The parasite-vector interaction of Chagas disease is still poorly understood and the understanding of this relationship can help in the development of new strategies to control Trypanosoma cruzi transmission, which is the etiological agent of this disease. Considering the need to know if T. cruzi can cause some pathology in the reproductive system of the Chagas disease vectors, we investigated the spermatogenesis of Triatoma infestans infected by T.

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  • Triatomines, which are blood-feeding insects, are significant because they transmit Chagas disease, and this study reports the discovery of Rhodnius montenegrensis in Amazonas, Brazil.
  • The research involved collecting Triatomines from Attalea butyracea palm trees in Guajará, where two adult female specimens of R. montenegrensis were found.
  • This finding increases the known triatomine species in the Amazon from 10 to 11 and expands the presence of R. montenegrensis in Brazil from two to three states.
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Objective: Warm water immersion therapy (WWIT) has been widely used in the treatment of various clinical conditions, with analgesic and anti-inflammatory effects. However, its mechanism of action has not been fully investigated. The present study analyzed the role of spinal inhibitory neuroreceptors in the antihyperalgesic effect of WWIT in an experimental model of inflammatory pain.

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Chagas disease is caused by the Trypanosoma cruzi and transmitted mainly by triatomines. Triatoma is a paraphyletic group and the species of this genus are grouped into complexes and subcomplexes. Morphological data and geographical distribution grouped initially T.

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The Triatoma genus is paraphyletic, and its species are grouped into complexes and subcomplexes. Given the fact that species that make up a given subcomplex generally share chromosomal traits, we analyzed the distribution of AT- and CG-rich DNA of the T. brasiliensis species subcomplex, in order to establish affinities among members of the T.

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Chagas disease is a public health problem caused by the , and the I (TcI) and II (TcII) groups are considered important genotypes from the clinical point of view. Currently, the groups need to be molecularly analyzed for their identification; thus, we cytogenetically analyzed these groups with the objective of developing more accessible techniques for the characterization of these parasites. TcI and TcII groups were differentiated by nucleus characterization with lacto-acetic orcein (TcI-nucleus with positive heteropycnosis and TcII-nucleus with negative heteropycnosis), emphasizing the importance of the application of this technique for epidemiological and clinical studies of Chagas disease.

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The subfamily Triatominae currently consists of 154 species, most of them being of great importance for public health because they are considered potential vectors of the protozoan , the etiologic agent of Chagas disease. In addition to their epidemiological importance, these insects are considered important biological models for cell studies because they have peculiar characteristics in their cells, for example, persistence of the nucleolus during spermatogenesis. This phenomenon is characterized by the presence of the nucleolus or nucleolar corpuscles during all phases of meiosis.

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