Publications by authors named "Roger A"

Introduction: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease predominantly affecting women, particularly in African American populations. While its physical health impacts are well-documented, patients also face significant psychosocial burdens, including barriers to healthcare access, financial constraints, mental health challenges, and inadequate social support.

Study Goal: This cross-sectional study surveyed 294 SLE patients recruited from Facebook and Reddit social media forums to examine how demographic factors such as age, race/ethnicity, and geographic location influence these burdens.

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Understanding the origin of eukaryotic cells is one of the most difficult problems in all of biology. A key challenge relevant to the question of eukaryogenesis is reconstructing the gene repertoire of the last eukaryotic common ancestor (LECA). As data sets grow, sketching an accurate genomics-informed picture of early eukaryotic cellular complexity requires provision of analytical resources and a commitment to data sharing.

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Background: Phosphodiesterase type 4D (PDE4D) breaks down cyclic AMP (cAMP) reducing the signaling of this intracellular second messenger which plays a major role in melanocyte pathophysiology. In advanced melanoma, expression of PDE4D is increased, plays a role in tumor invasion and is negatively associated with survival. In the current work, we investigated the role of PDE4D in the resistance of BRAF-mutated melanoma to mitogen-activated protein kinase (MAPK) pathway-targeted therapy.

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Symbiotic relationships between eukaryotes and prokaryotes played pivotal roles in the evolution of life and drove the emergence of specialized symbiotic structures in animals, plants and fungi. The host-evolved symbiotic structures of microbial eukaryotes - the vast majority of such hosts in nature - remain largely unstudied. Here we describe highly structured symbiosomes within three free-living anaerobic protists (Anaeramoeba spp.

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Background: Chronic spontaneous urticaria (CSU) is a highly prevalent and difficult to manage cutaneous disease characterized by the presence of recurrent urticaria, angioedema, or both, for a period of 6 weeks or longer. One of the biological treatments used for patients with CSU with an autoimmune background and bad control of the disease is omalizumab, an anti-IgE monoclonal antibody. The understanding of the mechanism of action of this biological drug in CSU along with the identification of potential biomarkers of clinical response can be helpful in the personalized management of the disease.

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Metamonads are a large and exclusively anaerobic group of protists. Additionally, they are one of the three clades proposed to ancestrally possess an "excavate" cell morphology, with a conspicuous ventral groove accompanied by a posterior flagellum with a vane. Here, we cultivate and characterize four anaerobic bacterivorous flagellates from hypersaline and alkaline soda lake environments, which represent a novel clade.

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Article Synopsis
  • Profile mixture models help understand how amino acids swap in proteins by using different sets of amino acid compositions at various sites, with a common matrix for their exchangeabilities.
  • The GTRpmix model improves these analyses by estimating a common exchangeability matrix for multiple profiles, leading to better fit and accuracy in phylogenetic studies compared to previously used matrices like LG.
  • Two new exchangeability matrices, ELM for eukaryotic proteins and EAL for eukaryotes and Archaea, enhance the performance of phylogenetic analyses with profile mixture models, and IQ-TREE2 now supports this advanced estimation.
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Metamonads are a diverse group of heterotrophic microbial eukaryotes adapted to living in hypoxic environments. All metamonads but one harbour metabolically altered 'mitochondrion-related organelles' (MROs) with reduced functions, however the degree of reduction varies. Here, we generate high-quality draft genomes, transcriptomes, and predicted proteomes for five recently discovered free-living metamonads.

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Increased inflammation is associated with the pathogenesis of heart failure (HF). Increased circulating levels of cytokines have been previously reported and generally associated with worse clinical outcomes. In this context, the modulation of inflammation-related parameters seems to be a reasonable therapeutic option for improving the clinical course of the disease.

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Duchenne muscular dystrophy (DMD) is the most common X-linked disease. DMD is caused by a lack of dystrophin, a critical structural protein in striated muscle. Dystrophin deficiency leads to inflammation, fibrosis, and muscle atrophy.

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Extremely halophilic archaea (Haloarchaea, Nanohaloarchaeota, Methanonatronarchaeia and Halarchaeoplasmatales) thrive in saturating salt concentrations where they must maintain osmotic equilibrium with their environment. The evolutionary history of adaptations enabling salt tolerance remains poorly understood, in particular because the phylogeny of several lineages is conflicting. Here we present a resolved phylogeny of extremely halophilic archaea obtained using improved taxon sampling and state-of-the-art phylogenetic approaches designed to cope with the strong compositional biases of their proteomes.

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Evolution has created complex mechanisms to sense environmental danger and protect tissues, with the nervous and immune systems playing pivotal roles. These systems work together, coordinating local and systemic reflexes to restore homeostasis in response to tissue injury and infection. By sharing receptors and ligands, they influence the pathogenesis of various diseases.

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Background: Some patients with severe asthma may benefit from treatment with biologics, but evidence has been mostly collected from randomized controlled trials (RCTs), in which patients' characteristics are different from those encountered in asthma patients in the real-world setting. The aim of this study was to describe the clinical features of complete responders versus non-complete responders to long-term treatment with biologics in patients with severe asthma attended in routine daily practice.

Methods: Data of a cohort of 90 patients with severe asthma who were treated with biologics (omalizumab, benralizumab, and mepolizumab) for at least 12 months and were followed up to March 2022.

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"Kingdom-level" branches are being added to the tree of eukaryotes at a rate approaching one per year, with no signs of slowing down. Some are completely new discoveries, whereas others are morphologically unusual protists that were previously described but lacked molecular data. For example, Hemimastigophora are predatory protists with two rows of flagella that were known since the 19 century but proved to represent a new deep-branching eukaryote lineage when phylogenomic analyses were conducted.

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Adsorption isotherms of pure vapors and vapor mixtures of water, methanol, and cyclohexane were studied using a synthesized 13X zeolite (FAU topology), by means of a DVS gravimetric vapor analyzer. These results were validated by GCMC calculations. The surface chemistry of the adsorbent was characterized by the thermodesorption of ammonia, and its textural properties were studied using nitrogen physisorption.

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VitB5 level becomes limiting in sarcomas. It is regulated by the pantetheinase activity of VNN1. VNN1 expression in sarcomas is associated with better prognosis and immune infiltration.

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Inteins are self-splicing protein elements found in viruses and all three domains of life. How the DNA encoding these selfish elements spreads within and between genomes is poorly understood, particularly in eukaryotes where inteins are scarce. Here, we show that the nuclear genomes of three strains of encode between 45 and 103 inteins, in stark contrast to four found in the most intein-rich eukaryotic genome described previously.

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Archamoebae comprises free-living or endobiotic amoebiform protists that inhabit anaerobic or microaerophilic environments and possess mitochondrion-related organelles (MROs) adapted to function anaerobically. We compared reconstructed MRO proteomes of eight species (six genera) and found that the common ancestor of Archamoebae possessed very few typical components of the protein translocation machinery, electron transport chain and tricarboxylic acid cycle. On the other hand, it contained a sulphate activation pathway and bacterial iron-sulphur (Fe-S) assembly system of MIS-type.

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Biochemical constraints on the admissible amino acids at specific sites in proteins lead to heterogeneity of the amino acid substitution process over sites in alignments. It is well known that phylogenetic models of protein sequence evolution that do not account for site heterogeneity are prone to long-branch attraction (LBA) artifacts. Profile mixture models were developed to model heterogeneity of preferred amino acids at sites via a finite distribution of site classes each with a distinct set of equilibrium amino acid frequencies.

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The tumor microenvironment is a dynamic network of stromal, cancer, and immune cells that interact and compete for resources. We have previously identified the Vanin1 pathway as a tumor suppressor of sarcoma development via vitamin B5 and coenzyme A regeneration. Using an aggressive sarcoma cell line that lacks Vnn1 expression, we showed that the administration of pantethine, a vitamin B5 precursor, attenuates tumor growth in immunocompetent but not nude mice.

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A study was conducted in 98 adult patients diagnosed with severe eosinophilic asthma (73.5% women, mean age 47.2 years) and followed prospectively for 1 year.

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Pompe disease is an autosomal recessive glycogen storage disease caused by mutations in the gene that encodes acid alpha-glucosidase (GAA)-an enzyme responsible for hydrolyzing lysosomal glycogen. GAA deficiency results in systemic lysosomal glycogen accumulation and cellular disruption. Glycogen accumulation in skeletal muscles, motor neurons, and airway smooth muscle cells is known to contribute to respiratory insufficiency in Pompe disease.

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Irritable bowel syndrome (IBS) is the most common gastrointestinal (GI) condition treated by GI and primary care physicians. Although IBS symptoms (abdominal pain, bowel problems) are generally refractory to medical therapies, consistent research has shown that they improve following cognitive-behavioral therapy (CBT). Notwithstanding empirical support for CBT, there is less research explicating the reasons for why or how it works.

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