Acta Trop
April 2024
Understanding the population dynamics of vectors is crucial for effective control of vector-borne diseases. In the Northeastern Brazilian semi-arid region, Triatoma brasiliensis persists as the most significant Chagas disease vector, frequently displaying recurrent domiciliary infestations. This situation raises relevant public health concerns in the municipality of Currais Novos in the state of Rio Grande do Norte.
View Article and Find Full Text PDFExploring the dynamics of disease transmission involves an understanding of complex interactions within the eco-epidemiologic framework. In the context of Chagas disease (CD), elements are mainly represented by the interactions among the pathogen, insect vector, host, humans and the environment. We performed quantitative and qualitative analyses on a dataset derived from 98 Triatoma brasiliensis infected by trypanosomatids, which were linked to a CD outbreak in the semi-arid region of northeastern Brazil.
View Article and Find Full Text PDFInsect Biochem Mol Biol
February 2024
Blood feeding is a secondary adaptation in hematophagous bugs. Many proteins are secreted in the saliva that are devoted to coping with the host's defense and to process the blood meal. Digestive enzymes that are no longer required for a blood meal would be expected to be eventually lost.
View Article and Find Full Text PDFChagas disease (CD) is a neglected illness affecting approximately seven million individuals, with vector transmission occurring via triatomine bugs. The Rhodniini tribe comprises 24 species, grouped into the and genera. Given the importance of accurately identifying CD vectors, the taxonomy of spp.
View Article and Find Full Text PDFThe genome size of five Rhodnius species (R. milesi, R. nasutus, R.
View Article and Find Full Text PDFRadiotherapy plays a key role in breast cancer treatment, and recent technical advances have been made to improve the therapeutic window by limiting the risk of radiation-induced toxicity or by increasing tumor control. Hadrontherapy is a form a radiotherapy relying on particle beams; compared with photon beams, particle beams have specific physical, radiobiological and immunological properties, which can be valuable in diverse clinical situations. To date, available hadrontherapy techniques for breast cancer irradiation include proton therapy, carbon ion radiation therapy, fast neutron therapy and boron neutron capture therapy.
View Article and Find Full Text PDFActa Trop
October 2021
This study aimed to identify the Trypanosoma cruzi genotypes and their relationship with parasitic load in distinct geographic and ecotypic populations of Triatoma brasiliensis in two sites, including one where a Chagas disease (ChD) outbreak occurred in Rio Grande do Norte state, Brazil. Triatomine captures were performed in peridomestic and sylvatic ecotopes in two municipalities: Marcelino Vieira - affected by the outbreak; and Currais Novos - where high pressure of peridomestic triatomine infestation after insecticide spraying have been reported. The kDNA-PCR was used to select 124 T.
View Article and Find Full Text PDFPurpose: Fricke dosimetry has shown great potential in the direct measurement of the absolute absorbed dose for Ir sources used in HDR brachytherapy. This work describes the determination of the correction factors necessary to convert the absorbed dose in the Fricke solution to the absorbed dose to water.
Methods: The experimental setup for Fricke irradiation using a Ir source was simulated.
Purpose: Small animal irradiators are equipped with x-ray beams and cone collimators with millimeter dimensions to be used in preclinical research. The use of small fields in the kV energy range may require the application of energy-dependent, field size-dependent, or depth-dependent correction factors to the dosimetric data acquired for treatment planning system (TPS) commissioning purposes to obtain accurate dose values. Considering that these corrections are also detector dependent, the suitability of a synthetic single-crystal diamond detector for small-field relative dosimetry in a preclinical irradiator (220-kVp) was evaluated to avoid the necessity of applying correction factors during TPS commissioning.
View Article and Find Full Text PDFCobalt-60 irradiators and soft X-ray machines are frequently used for research purposes, but the dosimetry is not always performed using the recommended protocols. This may lead to confusing and untrustworthy results within the conducted research. Postal dosimetry systems have already been approved by the IAEA, with thermoluminescence dosimeters (TLD) and optically stimulated luminescence (OSL) as the most commonly used dosimeter systems in these cases.
View Article and Find Full Text PDFActa Trop
March 2021
Chagas disease is a neglected tropical disease strongly associated with low socioeconomic status, affecting nearly 8 million people - mainly Latin Americans. The current infection risk is based on acute case reports, most of which are typically associated with oral transmissions. In the semi-arid region of Northeastern Brazil, serious outbreaks of this transmission type have surged in the last years.
View Article and Find Full Text PDFInnovative approaches used to combat Chagas disease transmission tend to combine a set of comprehensive efforts to understand the ecology of local vectors. In this work we identified molecularly the blood meal of 181 Triatoma brasiliensis, distributed in 18 populations (8 sylvatic and 10 peridomestic), which were collected across a range of 240 km (East-West) and 95 km (North-South) in the semi-arid region of northeastern, Brazil. We used the vertebrate mitochondrial gene (cytochrome B) sequencing applied to DNA isolated from bug midgut to identify the insect blood meal sources via the BLAST procedure.
View Article and Find Full Text PDFPurpose: The Fricke dosimeter has been shown to be a viable option as an absorbed dose standard. This work aims to provide the dose distribution in an irradiator container during blood irradiation using Fricke dosimetry.
Methods: Measurements were performed using a Gammacell Elan 3000 blood irradiator at Hemocenter in Rio de Janeiro, Brazil.
Purpose: For x-ray beams in the low and medium energy range, reference dosimetry is established in terms of air kerma. Fricke dosimetry has shown great potential in the absolute measurements of the absorbed dose to water for high-energy ranges. Therefore, the main purpose of this work was to compare the absorbed dose to water for medium-energy x-ray beams obtained through Fricke dosimetry with that obtained from the air kerma rate.
View Article and Find Full Text PDFParasit Vectors
September 2020
Background: The protozoan Trypanosoma cruzi circulates in semiarid areas of northeastern Brazil in distinct ecotopes (sylvatic, peridomestic and domestic) where Triatoma brasiliensis Neiva, 1911 is the most important Chagas disease vector. In this study, we analyzed microevolutionary and demographic aspects of T. brasiliensis populations at the ecotypic, micro and macro-geographic scales by combining morphometrics and molecular results.
View Article and Find Full Text PDFThe Triatoma brasiliensis complex is composed of six species (Triatoma bahiensis, T. juazerensis, T. lenti, T.
View Article and Find Full Text PDFInfect Genet Evol
August 2020
In semi-arid areas of northeastern Brazil, Chagas disease vectors of Triatoma brasiliensis species complex comprise a monophyletic group of kissing bugs that inhabit rock outcrops. Most of them exhibit allopatric or parapatric distribution; the exception is T. petrocchiae, which is found in cohabitation with T.
View Article and Find Full Text PDFFor the small animal radiation research platform (SARRP) with X-ray beams in the medium energy range (tube operating voltage at 220 kVp), reference dosimetry is based on the AAPM TG-61 recommendations following the in-phantom method. The objective of this study was to evaluate the feasibility of the Fricke solution as a dosimeter to determine the absorbed dose to water. Feasibility studies at this X-ray energy range are not widely available.
View Article and Find Full Text PDFImprovements in dosimetry in preclinical radiation research facilitate the application of results to the newest radiotherapy techniques, reducing gaps that hinder translation. Currently, guidelines for small-field kV photon dosimetry of small animal irradiators have not been published, and most of the publications are based on radiochromic film dosimetry. In this study, we evaluated the performance of four detectors, three ionization chambers (ICs): (PTW Advanced Markus, PTW Semiflex 31010, PTW PinPoint-3D 31016) and one solid-state detector (PTW 60017 unshielded Diode E) regarding their suitability for relative dosimetry of the small animal radiation research platform SARRP (220 kVp).
View Article and Find Full Text PDFActa Trop
January 2020
Triatoma petrocchiae is the newly member of the Triatoma brasiliensis species complex. This species overlaps with T. brasiliensis in geographic and ecotypic occupation in the sylvatic habitat because both inhabit rocky outcrops in the semi-arid portion of Brazilian northeast.
View Article and Find Full Text PDFChagas disease is one of the most significant systemic parasitosis in Latin America, caused by , which is mainly transmitted by hematophagous insects, the triatomines. This research was carried out in both domestic and wild environments throughout a Northeastern rural locality. Triatomines were captured in both peridomicile and wild environments, obtaining 508 specimens of triatomines, of which 99.
View Article and Find Full Text PDFIn the subfamily Triatominae, exhibits the largest number of species, which are arranged in complexes. For the species complex, recent investigations based on results of geometric morphometrics combined with phylogeny have provided evidence that it should be composed of seven species: , , , , and , in which is divided in two subspecies: and . A taxonomic key is presented to identify each taxon.
View Article and Find Full Text PDFRadiation damage is an important aspect to be considered when analysing biological samples with X-ray techniques as it can induce chemical and structural changes in the specimens. This work aims to provide new insights into the soft X-ray induced radiation damage of the complete sample, including not only the biological tissue itself but also the substrate and embedding medium, and the tissue fixation procedure. Sample preparation and handling involves an unavoidable interaction with the sample matrix and could play an important role in the radiation-damage mechanism.
View Article and Find Full Text PDF