Publications by authors named "Raquel C Theodoro"

commonly known as Chañar, is a native Chilean plant widely used in folk medicine for its expectorant, pain relief, and antinociceptive properties. This study explored the antioxidant, cytotoxic, and protective effects of its ethanolic (EE) and aqueous (EA) seed extracts against oxidative stress induced by copper sulfate, using both in vitro and in vivo approaches. Phytochemical analyses revealed the presence of phenolic compounds and flavonoids in the extracts.

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Group I introns are small RNAs (250-500 nt) capable of catalyzing their own splicing from the precursor RNA. They are widely distributed across the tree of life and have intricate relationships with their host genomes. In this work, we review its basic structure, self-splicing and its mechanisms of gene mobility.

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Medicinal plants, such as , are rich in antioxidant biomolecules, which are used in the treatment and prevention of many diseases. The antioxidant potential of extracts obtained from leaves and fruit peels was investigated using biochemical and 3T3 cell line assays as well as in vivo assays using an organism model . Four extracts were tested: hydroethanolic extracts from leaves (HF) and from fruit peels (HC), and infusion extracts from leaves (IF) and from fruit peels (IC).

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Article Synopsis
  • The study focuses on the species complexes that cause cryptococcosis, highlighting variations in virulence and antifungal susceptibility based on fungal genotypes.
  • It evaluates the presence of group I introns in mitochondrial genes across different isolates, using phylogenetic analysis to understand their origin and evolution.
  • The findings reveal significant polymorphism in intron presence and size, showing that while it's difficult to distinguish cryptic species with a single intron, combining multiple PCR methods can differentiate genotypes within each species complex.
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The genus has undergone many updates since it was first described; however, there are some missing pieces in the phylogenetic relationships among species. The present review aimed to: (i) understand the evolutionary meaning of their different spore wall ornamentations; (ii) define the best molecular marker for phylogenetic inferences, (iii) address some specific issues concerning the polyphyletic nature of and , and the inclusion of species; and (iv) update the global geographical distribution of species. As such, the wall ornamentation of previously described species was reviewed and phylogenetic analyses were carried out based on ITS and SSU-ITS-LSU (nrDNA).

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Inteins are genetic mobile elements that are inserted within protein-coding genes, which are usually housekeeping genes. They are transcribed and translated along with the host gene, then catalyze their own splicing out of the host protein, which assumes its functional conformation thereafter. As Prp8 inteins are found in several important fungal pathogens and are absent in mammals, they are considered potential therapeutic targets since inhibiting their splicing would selectively block the maturation of fungal proteins.

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Background: Histoplasmosis is a neglected disease that affects mainly immunocompromised patients, presenting a progressive dissemination pattern and a high mortality rate, mainly due to delayed diagnosis, caused by slow fungal growth in culture. Therefore, a fast, suitable and cost-effective assay is required for the diagnosis of histoplasmosis in resource-limited laboratories. This study aimed to develop and evaluate two new molecular approaches for a more cost-effective diagnosis of histoplasmosis.

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Inteins (internal proteins) are mobile genetic elements, inserted in housekeeping proteins, with self-splicing properties. Some of these elements have been recently pointed out as modulators of genetic expression or protein function. Herein, we evaluated, in silico, the distribution and phylogenetic patterns of PRP8 intein among 93 fungal strains of the order Onygenales.

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Background: Cryptococcosis is a common opportunistic infection in patients infected by Human Immunodeficiency Virus (HIV) and is the second leading cause of mortality in Acquired Immunodeficiency Syndrome (AIDS) patients worldwide. The most frequent presentation of cryptococcal infection is subacute meningitis, especially in patients with a CD4+ T Lymphocytes count below 100 cells/μL. However, in severely immunosuppressed individuals Cryptococcus neoformans can infect virtually any human organ, including the bone marrow, which is a rare presentation of cryptococcosis.

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Cryptococcosis, one of the most important systemic mycosis in the world, is caused by different genotypes of and , which differ in their ecology, epidemiology, and antifungal susceptibility. Therefore, the search for new molecular markers for genotyping, pathogenicity and drug susceptibility is necessary. Group I introns fulfill the requisites for such task because (i) they are polymorphic sequences; (ii) their self-splicing is inhibited by some drugs; and (iii) their correct splicing under parasitic conditions is indispensable for pathogen survival.

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Background: Fluorescence in situ hybridisation (FISH) associated with Tyramide Signal Amplification (TSA) using oligonucleotides labeled with non-radioactive fluorophores is a promising technique for detection and differentiation of fungal species in environmental or clinical samples, being suitable for microorganisms which are difficult or even impossible to culture.

Objective: In this study, we aimed to standardise an in situ hybridisation technique for the differentiation between the pathogenic species Paracoccidioides brasiliensis and Paracoccidioides lutzii, by using species-specific DNA probes targeting the internal transcribed spacer-1 (ITS-1) of the rRNA gene.

Methods: Yeast and mycelial phase of each Paracoccidioides species, were tested by two different detection/differentiation techniques: TSA-FISH for P.

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Inteins are invasive intervening sequences that perform an autocatalytic splicing from their host proteins. Among eukaryotes, these elements are present in many fungal species, including those considered opportunistic or primary pathogens, such as spp. Here we reviewed and updated the list of species containing inteins in the genes and and pointed out the importance of these elements as molecular markers for molecular epidemiological researches and species-specific diagnosis, since the presence, as well as the size of these inteins, is polymorphic among the different species.

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Article Synopsis
  • Dermatophytes are a group of fungi that can degrade keratin and cause infections in humans and animals, belonging to the genera Trichophyton, Epidermophyton, and Microsporum.
  • Molecular techniques, particularly DNA sequencing of ribosomal regions, have improved the identification and understanding of these fungi's evolutionary relationships.
  • In a study of 45 strains from Brazil and Latin America, 95.5% were identified using ITS sequencing, while 100% were identified using D1/D2 sequencing, revealing complex phylogenetic relationships among dermatophyte species.
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Background: Histoplasma capsulatum comprises a worldwide complex of saprobiotic fungi mainly found in nitrogen/phosphate (often bird guano) enriched soils. The microconidia of Histoplasma species may be inhaled by mammalian hosts, and is followed by a rapid conversion to yeast that can persist in host tissues causing histoplasmosis, a deep pulmonary/systemic mycosis. Histoplasma capsulatum sensu lato is a complex of at least eight clades geographically distributed as follows: Australia, Netherlands, Eurasia, North American classes 1 and 2 (NAm 1 and NAm 2), Latin American groups A and B (LAm A and LAm B) and Africa.

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Background: Paracoccidioides brasiliensis and Paracoccidioides lutzii are the etiological agents of Paracoccidioidomycosis (PCM), and are easily isolated from human patients. However, due to human migration and a long latency period, clinical isolates do not reflect the spatial distribution of these pathogens. Molecular detection of P.

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To commemorate Prof. Carlos da Silva Lacaz's centennial anniversary, the authors have written a brief account of a few, out of hundreds, biological, ecological, molecular and phylogenetic studies that led to the arrival of Paracoccidioides lutzii, hidden for more than a century within Paracoccidioides brasiliensis. Lacaz's permanent interest in this fungus, and particularly his conviction on the benefits that research on paracoccidioidomycosis would bring to patients, were pivotal in the development of the field.

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Improved methods for the detection of Histoplasma capsulatum are needed in regions with limited resources in which the organism is endemic, where delayed diagnosis of progressive disseminated histoplasmosis (PDH) results in high mortality rates. We have investigated the use of a loop-mediated isothermal amplification (LAMP) assay to facilitate rapid inexpensive molecular diagnosis of this disease. Primers for LAMP were designed to amplify the Hcp100 locus of H.

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We aimed to evaluate whether the occurrence of cryptic species of Paracoccidioides brasiliensis, S1, PS2, PS3 and Paracoccidioides lutzii, has implications in the immunodiagnosis of paracoccidioidomycosis (PCM). Small quantities of the antigen gp43 were found in culture filtrates of P. lutzii strains and this molecule appeared to be more variable within P.

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Inteins are coding sequences that are transcribed and translated with flanking sequences and then are excised by an autocatalytic process. There are two types of inteins in fungi, mini-inteins and full-length inteins, both of which present a splicing domain containing well-conserved amino acid sequences. Full-length inteins also present a homing endonuclease domain that makes the intein a mobile genetic element.

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Paracoccidioides lutzii, formerly known as 'Pb01-like' strains in the P. brasiliensis complex, is proposed as a new species based on phylogenetic and comparative genomics data, recombination analysis, and morphological characteristics. Conidia of P.

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The PRP8 intein is the most widespread intein among the Kingdom Fungi. This genetic element occurs within the prp8 gene, and is transcribed and translated simultaneously with the gene. After translation, the intein excises itself from the Prp8 protein by an autocatalytic splicing reaction, subsequently joining the N and C terminals of the host protein, which retains its functional conformation.

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The genus Paracoccidioides includes the thermodimorphic species Paracoccidioides brasiliensis and P. lutzii, both of which are etiologic agents of paracoccidioidomycosis, a systemic mycosis that affects humans in Latin America. Despite the common occurrence of a sexual stage among closely related fungi, this has not been observed with Paracoccidioides species, which have thus been considered asexual.

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Article Synopsis
  • This study explores the use of aerosol sampling to detect the Paracoccidioides fungi, responsible for paracoccidioidomycosis, by placing air samplers near armadillo burrows, a known reservoir for the pathogen.
  • Various methods, including direct culture and Nested PCR, were employed for detection, with Nested PCR found to be the most effective despite culturing efforts failing to isolate the pathogen.
  • The research revealed that the ITS sequences matched closely with Paracoccidioides lutzii, suggesting that this species might be more widely distributed than previously thought, potentially extending beyond mid-western Brazil.
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