Publications by authors named "Maria C da Silva"

Article Synopsis
  • Chagas disease, sleeping sickness, and malaria are serious infections caused by protozoan parasites that affect millions globally.
  • In an experiment, synthetic polyalanine peptides were tested for their effectiveness against these parasites, showing that two specific peptides inhibited growth significantly.
  • Structural analysis revealed that one peptide interacts more deeply with cell membranes, suggesting different mechanisms of action, which supports the idea of using these peptides as potential treatments for sleeping sickness.
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  • Chagas disease (ChD) is caused by the parasite Trypanosoma cruzi, which has seven genetic groups; this study focused on understanding how these groups relate to chronic Chagas cardiomyopathy (CCC) in Brazilian patients.
  • The research involved clinically assessing 330 patients and conducting DNA extraction and genotyping, finding that the majority of positive cases had the TcII and TcVI genotypes.
  • The study highlighted that TcII is the most prevalent genotype among CCC patients in Brazil, supporting previous research on genetic variability and its potential impact on the disease's clinical forms.
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  • A study analyzed Bacillus thuringiensis (Bt) isolates from Maranhão (BtMA) that are toxic to Aedes aegypti larvae, using rep-PCR techniques with various genetic markers to assess genetic diversity.
  • The rep-PCR analysis identified 38 genetic variations and revealed eight distinct groups, indicating significant genetic diversity among 30 BtMA isolates.
  • Despite the genetic diversity, the study found a low correlation between the collection site and the effectiveness in killing A. aegypti larvae, suggesting that BtMA isolates could be effective alternatives for controlling this mosquito and other harmful pests.
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  • Bacillus thuringiensis produces important toxins, particularly Cry and Cyt toxins, which are effective in controlling mosquito populations during the sporulation process.
  • The study aimed to identify the frequency of the Cyt1Aa gene in various native B. thuringiensis isolates taken from soil, insects, and water samples, examining genetic variations among those isolates.
  • Out of 1,448 analyzed strains, only 32 (2.3%) were found to have the cyt1Aa gene, with the highest occurrence (3.4%) found in samples from the Cerrado biome, indicating that the cyt1Aa gene is conserved without any single-base changes in the examined region.
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  • * A study evaluated 181 CCC patients and found that 77.3% had a preserved left ventricular ejection fraction (LVEF), while the rest showed LV dysfunction.
  • * Results indicated a large variability in parasite load, with a higher parasite load associated with lower LVEF, suggesting a direct relation between parasite levels and heart function in CCC patients.
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  • The study investigates the genetic variability within the discrete typing unit (DTU) TcV of the parasite that causes Chagas disease in Bolivian patients living in Barcelona, Spain.
  • It analyzes DNA extracted from 27 patients and reveals three distinct genetic groups with significant intragroup genetic diversity.
  • The findings suggest that specific alleles of the parasite may be linked to the indeterminate form of Chagas disease, highlighting the importance of identifying genetic markers connected to the disease's clinical manifestations.
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This study is a pioneer in reporting the antibacterial properties of the species Baill. The genus belongs to the family Euphorbiaceae composed of numerous species with documented biological activities. However, the pharmacological properties of remain poorly understood.

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  • Three new marine nematode species were identified in the Potiguar Basin, northeastern Brazil, and classified under a new genus called Spinonema.
  • These nematodes have distinct features like a coarsely annulated cuticle, unique lateral alae resembling the letter C, and variations in spines and spicules among species.
  • The type species, Spinonema cuticulatum, presents specific anatomical traits, while the other two species, Spinonema spirale and Spinonema absente, showcase their own unique attributes, further distinguishing them within the genus.
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Aim: To evaluate the effects of low-volume resistance training on the physical and functional capacity of older patients with Parkinson's disease.

Methods: A total of 54 patients (aged ≥60 years) were randomly divided into two groups: (i) a control group comprising 13 men and 14 women; and (ii) a resistance training group with 14 men and 13 women. The resistance training group, in addition to maintaining their pharmacological treatments, carried out 6 months of resistance training twice a week, whereas the control group maintained their pharmacological treatments.

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The occurrence of Aedes aegypti, Culex quinquefasciatus, and mosquitoes of the genus Anopheles potentiate the spread of several diseases, such as dengue, Zika, chikungunya, urban yellow fever, filariasis, and malaria, a situation currently existing in Brazil and in Latin America. Control of the disease vectors is the most effective tool for containing the transmission of the pathogens causing these diseases, and the bacterium Bacillus thuringiensis var. israelensis has been widely used and has shown efficacy over many years.

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Epidemiological studies found that hepatitis E virus genotype 3 (HEV-3) infection was associated with chronic hepatitis and cirrhosis in immunocompromised patients. Our study aimed to investigate the relationship between the host immunosuppressive status and the occurrence of HEV-related chronic hepatitis. Here we describe a successful experimental study, using cynomolgus monkeys previously treated with tacrolimus, a potent calcineurin inhibitor immunosuppressant, and infected with a Brazilian HEV-3 strain isolated from naturally infected pigs.

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Chemokines (CKs) and chemokine receptors (CKR) promote leukocyte recruitment into cardiac tissue infected by the . This study investigated the long-term treatment with subantimicrobial doses of doxycycline (Dox) in association, or not, with benznidazole (Bz) on the expression of CK and CKR in cardiac tissue. Thirty mongrel dogs were infected, or not, with the Berenice-78 strain of and grouped according their treatments: (i) two months after infection, Dox (50 mg/kg) 2x/day for 12 months; (ii) nine months after infection, Bz (3,5 mg/kg) 2x/day for 60 days; (iii) Dox + Bz; and (iv) vehicle.

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The development of delivery systems efficiently uptaken by cells is of due importance since sites of drug action are generally localized in subcellular compartments. Herein, naked and core-shell polymeric nanoparticles (NPs) have been produced from poly(lactic-co-glycolic acid)-PLGA, poly(ethylene oxide)-b-poly(ε-caprolactone)-PEO-b-PCL, and poly(ethylene oxide)-b-poly(lactic acid)-PEO-b-PLA. The nanostructures are characterized and the cellular uptake behavior is evaluated.

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Vitellogenin (Vg), a yolk protein precursor, is the primary egg nutrient source involved in insect reproduction and embryo development. The Cotton Boll weevil (CBW) Anthonomus grandis Boheman, the most important cotton pest in Americas, accumulates large amounts of Vg during reproduction. However, the precise role of this protein during embryo development in this insect remains unknown.

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Gossypium hirsutum (commercial cooton) is one of the most economically important fibers sources and a commodity crop highly affected by insect pests and pathogens. Several transgenic approaches have been developed to improve cotton resistance to insect pests, through the transgenic expression of different factors, including Cry toxins, proteinase inhibitors, and toxic peptides, among others. In the present study, we developed transgenic cotton plants by fertilized floral buds injection (through the pollen-tube pathway technique) using an DNA expression cassette harboring the cry1Ia12 gene, driven by CaMV35S promoter.

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Background: The presence of nucleated red blood cells (NRBCs) in the peripheral blood of critically ill patients is associated with a poorer prognosis, though data on cardiovascular critical care patients is lacking. The aim of the present study was to assess the role of NRBCs as a predictor of intensive care unit (ICU) and in hospital all-cause mortality among cardiologic patients.

Methods: NRBCs were measured daily in consecutive cardiac ICU patients, including individuals with both coronary and non-coronary acute cardiac care.

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Recovery of mercury from effluents is fundamental for environmental preservation. A new, green method was developed for separation of mercury from effluent containing different metals. The extraction/separation of Hg(II) was studied using aqueous two-phase system (ATPS) comprising by polyethylene oxide (PEO1500) or triblock copolymers (L64 or L35), electrolyte (sodium citrate or sodium sulfate) and water in the presence or absence of chloride ions.

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Sugarcane is a widely cultivated plant that serves primarily as a source of sugar and ethanol. Its annual yield can be significantly reduced by the action of several insect pests including the sugarcane giant borer (Telchin licus licus), a lepidopteran that presents a long life cycle and which efforts to control it using pesticides have been inefficient. Although its economical relevance, only a few DNA sequences are available for this species in the GenBank.

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Bacillus thuringiensis (Bt) is a gram-positive spore-forming soil bacterium that is distributed worldwide. Originally recognized as a pathogen of the silkworm, several strains were found on epizootic events in insect pests. In the 1960s, Bt began to be successfully used to control insect pests in agriculture, particularly because of its specificity, which reflects directly on their lack of cytotoxicity to human health, non-target organisms and the environment.

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Cotton plants are subjected to the attack of several insect pests. In Brazil, the cotton boll weevil, Anthonomus grandis, is the most important cotton pest. The use of insecticidal proteins and gene silencing by interference RNA (RNAi) as techniques for insect control are promising strategies, which has been applied in the last few years.

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Glioblastoma multiforme is the most prevalent and malignant tumor of the central nervous system. In the last few years, accumulating evidence has suggested an association between human cytomegalovirus (HCMV) infection and glioblastoma multiforme. In this study, tumor tissues and peripheral blood of patients with glioblastoma multiforme were examined for the presence of HCMV DNA.

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Numerous species of insect pests attack cotton plants, out of which the cotton boll weevil (Anthonomus grandis) is the main insect in Brazil and must be controlled to avert large economic losses. Like other insect pests, A. grandis secretes a high level of α-amylases in the midgut lumen, which are required for digestion of carbohydrates.

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Background: Root-knot nematodes (RKN- Meloidogyne genus) present extensive challenges to soybean crop. The soybean line (PI 595099) is known to be resistant against specific strains and races of nematode species, thus its differential gene expression analysis can lead to a comprehensive gene expression profiling in the incompatible soybean-RKN interaction. Even though many disease resistance genes have been studied, little has been reported about phytohormone crosstalk on modulation of ROS signaling during soybean-RKN interaction.

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This work developed a new and efficient method of extracting and separating Co(II), Ni(II) and Cd(II) in aqueous two-phase systems (ATPS) composed of triblock copolymer (L64)+Na(2)C(4)H(4)O(6)+water and L64+Li(2)SO(4)+water using the hydrophobic extractant 1-nitroso-2-naphtol, which complexes the metal ions and partitions in the triblock copolymer micelles in the ATPS top phase. Metal extraction from the salt-rich phase to the copolymer - rich phase is strongly affected by the fine-tuning of the following parameters: amount of added extractant, type of electrolyte, pH, and tie-line length. Excellent separation factors (S(i,j)) between the metals were obtained at pH=3.

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In the current study we screened Escherichia coli from intestine of pigs slaughtered in Mato Grosso, Brazil, for virulence-markers related to human disease. Furthermore, we employed for the first time a phylogenetic assay to explore the association between phylogeny and virulence genotype in E. coli from finished swine.

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