Publications by authors named "Gustavo A Souza"

Background And Objectives: A bacterial brain abscess is an emergency and should be drained of pus within 24 hours of diagnosis, as recently recommended. In this cross-sectional study, we investigated whether delaying pus drainage entails brain abscess expansion and what the underlying mechanism might be.

Methods: Repeated brain MRI of 47 patients who did not undergo immediate pus drainage, pus osmolarity measurements, immunocytochemistry, proteomics, and 18F-fluorodeoxyglucose positron emission tomography.

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Introduction: Burns are defined as a traumatic injury, usually of thermal origin, that affects the epithelial and adjacent tissue and is classified according to the depth reached. Tissue repair involved in this type of injury is often a challenge both due to its severity and the multiplicity of complications. Regenerative medicine has focused on the use of low-level laser photobiomodulation therapy (LLLT) and adipose-derived stem cells (ADSC), especially in the early stages of the process, to promote better healing and shorten repair time.

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Background: Uterine leiomyosarcoma (uLMS) are rare and malignant tumors that arise in the myometrium cells and whose diagnosis is based on histopathological features. Identifying diagnostic biomarkers for uLMS is a challenge due to molecular heterogeneity and the scarcity of samples. In vivo and in vitro models for uLMS are urgently needed.

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Background: The growth of malignant tumors is influenced by their microenvironment. Glioblastoma, an aggressive primary brain tumor, may have cysts containing fluid that represents the tumor microenvironment. The aim of this study was to investigate whether the cyst fluid of cystic glioblastomas contains growth-stimulating factors.

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The demographic shift toward an older population will increase the number of prostate cancer cases. A challenge in the treatment of prostate cancer is to avoid undertreatment of patients at high risk of progression following curative treatment. These men can benefit from early salvage treatment.

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The PII family comprises a group of widely distributed signal transduction proteins ubiquitous in prokaryotes and in the chloroplasts of plants. PII proteins sense the levels of key metabolites ATP, ADP, and 2-oxoglutarate, which affect the PII protein structure and thereby the ability of PII to interact with a range of target proteins. Here, we performed multiple ligand fishing assays with the PII protein orthologue GlnZ from the plant growth-promoting nitrogen-fixing bacterium to identify 37 proteins that are likely to be part of the PII protein-protein interaction network.

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In reverse vaccinology approaches, complete proteomes of bacteria are submitted to multiple computational prediction steps in order to filter proteins that are possible vaccine candidates. Most available tools perform such analysis only in a single strain, or a very limited number of strains. But the vast amount of genomic data had shown that most bacteria contain pangenomes, i.

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NAD is a central metabolite participating in core metabolic redox reactions. The prokaryotic NAD synthetase enzyme NadE catalyzes the last step of NAD biosynthesis, converting nicotinic acid adenine dinucleotide (NaAD) to NAD Some members of the NadE family use l-glutamine as a nitrogen donor and are named NadE Previous gene neighborhood analysis has indicated that the bacterial gene is frequently clustered with the gene encoding the regulatory signal transduction protein PII, suggesting a functional relationship between these proteins in response to the nutritional status and the carbon/nitrogen ratio of the bacterial cell. Here, using affinity chromatography, bioinformatics analyses, NAD synthetase activity, and biolayer interferometry assays, we show that PII and NadE physically interact , that this complex relieves NadE negative feedback inhibition by NAD This mechanism is conserved in distantly related bacteria.

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is a diazotrophic microorganism capable of associating with roots of important grasses and cereals, promoting plant growth and increasing crop yields. Nitrogen levels and the Ntr regulatory system control the nitrogen metabolism in . This system comprises the nitrogen regulatory proteins GlnD, which is capable of adding uridylyl groups to the PII proteins, GlnB (PII-1) and GlnZ (PII-2), under limiting nitrogen levels.

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In proteomics, peptide information within mass spectrometry (MS) data from a specific organism sample is routinely matched against a protein sequence database that best represent such organism. However, if the species/strain in the sample is unknown or genetically poorly characterized, it becomes challenging to determine a database which can represent such sample. Building customized protein sequence databases merging multiple strains for a given species has become a strategy to overcome such restrictions.

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In multiple sclerosis (MS), B cells are trafficking across the blood-brain barrier, but it is not known how this relates to the synthesis of oligoclonal IgG. We used quantitative mass spectrometry of oligoclonal bands and high-throughput sequencing of immunoglobulin heavy-chain variable transcripts to study the longitudinal B cell response in the cerebrospinal fluid (CSF) and blood of two MS patients. Twenty of 22 (91%) and 25 of 28 (89%) of oligoclonal band peptides persisted in samples collected 18 months apart, in spite of a dynamic exchange across the blood-CSF barrier of B lineage cells connecting to oligoclonal IgG.

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Costameres are signaling hubs at the sarcolemma and important contact points between the extracellular matrix and cell interior, sensing and transducing biomechanical signals into a cellular response. The transmembrane proteoglycan syndecan-4 localizes to these attachment points and has been shown to be important in the initial stages of cardiac remodeling, but its mechanistic function in the heart remains insufficiently understood. Here, we sought to map the cardiac interactome of syndecan-4 to better understand its function and downstream signaling mechanisms.

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The use of two-implant overdentures improves mastication of edentulous elderly patients. However, little is known about the effects of single-implant overdentures (SIO) on oral perception and masticatory function in such elders. This study compared the effects of conventional complete dentures (CD) and SIO on the oral sensorimotor ability (OSA), masticatory function, and nutritional intake of elderly people with residual alveolar mandibular height classified as Class III or IV according to the American College of Prosthodontics.

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Western blotting (WB) is widely used to test antibody specificity, but the assay has low throughput and precision. Here we used preparative gel electrophoresis to develop a capture format for WB. Fractions with soluble, size-separated proteins facilitated parallel readout with antibody arrays, shotgun mass spectrometry (MS) and immunoprecipitation followed by MS (IP-MS).

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Article Synopsis
  • Advances in mass spectrometry and bioinformatics now allow for global analysis of tissue proteomes from small biopsy samples, particularly useful in studying celiac disease (CD).
  • In CD, gluten triggers an immune response that alters the small intestine; removing gluten normalizes tissue structure and immune activity.
  • This study compared protein expression in biopsy samples before and after a gluten-free diet or after gluten provocation, identifying specific proteins that distinguish treated from untreated CD and revealing markers like IGHV5-51 for ongoing immune activation.
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Recently, FGFR1 was found to be overexpressed in osteosarcoma and represents an important target for precision medicine. However, because targeted cancer therapy based on FGFR inhibitors has so far been less efficient than expected, a detailed understanding of the target is important. We have here applied proximity-dependent biotin labeling combined with label-free quantitative mass spectrometry to identify determinants of FGFR1 activity in an osteosarcoma cell line.

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Article Synopsis
  • The carbohydrate-uptake phosphorelay system (PTS) in bacteria, particularly E. coli, plays a role in regulating the use of secondary carbon sources, although the nitrogen-related version of PTS does not directly influence nitrogen metabolism as previously thought.
  • Research indicated that deleting the ptsN gene in E. coli leads to impaired growth in minimal media, highlighting its importance for bacterial fitness.
  • Proteomic analysis revealed that ptsN does not affect the canonical nitrogen regulatory system but is essential for balancing the activities of sigma factors RpoS and RpoD, causing a shift towards increased expression of RpoS-dependent genes when ptsN is absent.
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Cancer/testis (CT) genes are excellent candidates for cancer immunotherapies because of their restrict expression in normal tissues and the capacity to elicit an immune response when expressed in tumor cells. In this study, we provide a genome-wide screen for CT genes with the identification of 745 putative CT genes. Comparison with a set of known CT genes shows that 201 new CT genes were identified.

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Introduction: Fibrinogen A alpha chain amyloidosis is an autosomal dominant disease associated with mutations in the fibrinogen A alpha chain () gene, and it is the most common cause of hereditary renal amyloidosis in the UK. Patients typically present with kidney impairment and progress to end-stage renal disease over a median time of 4.6 years.

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OBJECTIVE What determines the extent of tissue destruction during brain abscess formation is not known. Pyogenic brain infections cause destruction of brain tissue that greatly exceeds the area occupied by microbes, as seen in experimental studies, pointing to cytotoxic factors other than microbes in pus. This study examined whether brain abscess pus contains cytotoxic proteins that might explain the extent of tissue destruction.

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Mass spectrometry (MS)-based immunopeptidomics investigates the repertoire of peptides presented at the cell surface by major histocompatibility complex (MHC) molecules. The broad clinical relevance of MHC-associated peptides, e.g.

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Article Synopsis
  • Mucosal antigens stimulate the production of plasma cells in the lamina propria that secrete dimeric immunoglobulin A (IgA) for epithelial transport, while blood also contains monomeric IgA.
  • Research on celiac disease patients revealed a connection between gut plasma cells and serum antibody responses, specifically IgA and IgG against gluten-related peptides and transglutaminase 2.
  • Proteomic analysis indicated that B cell clones producing antibodies in the gut also contribute to the serum antibody levels, but the serum IgA has a different molecular makeup compared to the IgA produced in the gut, indicating distinct populations of plasma cells.
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Article Synopsis
  • - The sodium-calcium exchanger 1 (NCX1) helps regulate calcium levels in the heart and is crucial for heart relaxation; its dysfunction is linked to severe heart failure.
  • - Researchers used advanced techniques to identify new proteins that interact with NCX1 in rat heart tissue, resulting in the discovery of 462 potential protein partners, with ten being novel and two enhancing NCX1 activity.
  • - A detailed interaction map of NCX1 was created, revealing clusters of proteins involved in "cell communication" and "signal transduction," indicating potential novel targets for drugs related to cardiovascular diseases.
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In this manuscript we describe Proteogenomics Viewer, a web-based tool that collects MS peptide identification, indexes to genomic sequence and structure, assigns exon usage, reports the identified protein isoforms with genomic alignments and, most importantly, allows the inspection of MS2 information for proper peptide identification. It also provides all performed indexing to facilitate global analysis of the data. The relevance of such tool is that there has been an increase in the number of proteogenomic efforts to improve the annotation of both genomics and proteomics data, culminating with the release of the two human proteome drafts.

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Melanoma is responsible for most deaths among skin cancers and conventional and palliative care chemotherapy are limited due to the development of chemoresistance. We used proteomic analysis to identify cellular responses that lead to chemoresistance of human melanoma cell lines to cisplatin. A systems approach to the proteomic data indicated the participation of specific cellular processes such as oxidative phosphorylation, mitochondrial organization and homeostasis, as well as the unfolded protein response (UPR) to be required for the survival of cells treated with cisplatin.

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