Background: The role of serotonin in pulmonary arterial hypertension has been extensively studied in recent decades, with preclinical data strongly indicating involvement in disease pathogenesis; however, clinical studies have yielded mixed results.
Methods: ELEVATE-2 was a phase 2b dose-ranging, randomised, double-blind, placebo-controlled, multicentre trial investigating rodatristat ethyl as a treatment for patients with pulmonary arterial hypertension. The study was conducted at 64 sites across 16 countries in Europe and North America.
Serotonin is often referred to as a "happy hormone" as it maintains good mood, well-being, and happiness. It is involved in communication between nerve cells and plays a role in sleeping and digestion. However, too much serotonin can have pathogenic effects and serotonin synthesis is elevated in pulmonary artery endothelial cells from patients with pulmonary arterial hypertension (PAH).
View Article and Find Full Text PDFSerotonin plays a key role in the development and maintenance of the pathobiology associated with pulmonary arterial hypertension (PAH). Platelet-driven and locally produced serotonin from lung tissue and arterial endothelial cells induce excessive growth of pulmonary artery smooth muscle cells. The unchecked growth of these cells is a major driver of PAH including the remodeling of pulmonary arteries that dramatically reduces the diameter and flexibility of the arterial lumen.
View Article and Find Full Text PDFThe polysaccharide capsule is an essential virulence factor for in both community-acquired hypervirulent strains as well as health care-associated classical strains that are posing significant challenges due to multidrug resistance. Capsule production is known to be transcriptionally regulated by a number of proteins, but very little is known about how these proteins collectively control capsule production. RmpA and RcsB are two known regulators of capsule gene expression, and RmpA is required for the hypermucoviscous (HMV) phenotype in hypervirulent strains.
View Article and Find Full Text PDFis widely recognized as a pathogen with a propensity for acquiring antibiotic resistance. It is capable of causing a range of hospital-acquired infections (urinary tract infections [UTI], pneumonia, sepsis) and community-acquired invasive infections. The genetic heterogeneity of isolates complicates our ability to understand the virulence of Characterization of virulence factors conserved between strains as well as strain-specific factors will improve our understanding of this important pathogen.
View Article and Find Full Text PDFis considered a significant public health threat because of the emergence of multidrug-resistant strains and the challenge associated with treating life-threatening infections. Capsule, siderophores, and adhesins have been implicated as virulence determinants of , yet we lack a clear understanding of how this pathogen causes disease. In a previous screen for virulence genes, we identified a potential new virulence locus and constructed a mutant () with this locus deleted.
View Article and Find Full Text PDFKlebsiella pneumoniae is the causative agent of a variety of diseases, including pneumonia, urinary tract infections, septicemia, and the recently recognized pyogenic liver abscesses (PLA). Renewed efforts to identify and understand the bacterial determinants required to cause disease have come about because of the worldwide increase in the isolation of strains resistant to a broad spectrum of antibiotics. The recent increased isolation of carbapenem-resistant strains further reduces the available treatment options.
View Article and Find Full Text PDFInfection with multidrug-resistant Klebsiella pneumoniae is a significant problem worldwide, requiring a better understanding of how various strains are able to defeat current antibiotic therapies and cause disease. Here, we report the draft genome sequences of three K. pneumoniae strains harboring the SHV-18, KPC-2, or NDM-1 β-lactamases.
View Article and Find Full Text PDFMorphine differs from most opiates its poor ability to internalize μ opioid receptors (μORs). However, chronic treatment with morphine produces adaptational changes at the dynamin level, which enhance the efficiency of acute morphine stimulation to promote μOR internalization in enteric neurons. This study tested the effect of chronic treatment with fentanyl, a μOR-internalizing agonist, on ligand-induced endocytosis and the expression of the intracellular trafficking proteins, dynamin and β-arrestin, in enteric neurons using organotypic cultures of the guinea pig ileum.
View Article and Find Full Text PDFYersinia pestis CO92 has 12 open reading frames encoding putative conventional autotransporters (yaps), nine of which appear to produce functional proteins. Here, we demonstrate the ability of the Yap proteins to localize to the cell surface of both Escherichia coli and Yersinia pestis and show that a subset of these proteins undergoes processing by bacterial surface omptins to be released into the supernatant. Numerous autotransporters have been implicated in pathogenesis, suggesting a role for the Yaps as virulence factors in Y.
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