scholarly journals Role of Carbonate Species on General Acid Catalysis of Bromide Oxidation by Hypochlorous Acid (HOCl) and Oxidation by Molecular Chlorine (Cl2)

2020 ◽  
Vol 54 (24) ◽  
pp. 16186-16194
Author(s):  
Samuel H. Brodfuehrer ◽  
David G. Wahman ◽  
Abdalrahman Alsulaili ◽  
Gerald E. Speitel ◽  
Lynn E. Katz
Keyword(s):  
Acid Catalysis ◽  
Hypochlorous Acid ◽  
Molecular Chlorine ◽  
General Acid ◽  
Carbonate Species

THE ROLE OF MYELOPEROXIDASE AND NEUTROPHIL EXTRACELLULAR TRAPS IN THE PATHOGENESIS OF INFLAMMATORY BOWEL DISEASE

2021 ◽  
Vol 27 (Supplement_1) ◽  
pp. S4-S4
Author(s):  
Belal Chami ◽  
Gulfam Ahmad ◽  
Angie Schroder ◽  
Patrick San Gabriel ◽  
Paul Witting
Keyword(s):  
Disease Severity ◽  
Hypochlorous Acid ◽  
Tissue Injury ◽  
Activity Index ◽  
Critical Role ◽  
Neutrophil Migration ◽  
Sodium Sulphate ◽  
Host Tissue ◽  
Neutrophil Extracellular Trap

Abstract Neutrophils are short-lived immune cells that represent the major cell type recruited to the inflamed bowel releasing their azurophilic granules containing enzymes myeloperoxidase (MPO). Fecal and serum MPO levels has previously been shown to correlate to disease severity in IBD patients. MPO, in the presence of H2O2 and free Cl- undergoes a halogenation cycle, yielding the two-electron oxidant, hypochlorous acid (HOCl) - a potent bactericidal agent. However, chronic intestinal exposure to MPO/HOCl due to perpetual inflammation may cause secondary host-tissue injury and cell death. Neutrophil Extracellular Trap (NET)osis is a specialised form of neutrophil death where MPO is entrapped in a DNA scaffold and continues to elicit HOCl activity and may further contribute to host-tissue injury. We investigated the presence of NETs in surgically excised ileum samples from CD and healthy patients using advanced confocal microscopic techniques and found MPO, Neutrophil Elastase (NE) and Citrullinated Histone h3 (CitH3) - critical components of NET formation, individually positively correlate to the severity of histopathological intestinal injury. Furthermore, multiplex Opal™ IHC performed using LMS880 Airyscan-moduled microscopy with z-stacking revealed colocalization of NE, MPO, CitH3 and DAPI indicating the extensive presence of NETs in severely affected CD tissue. Using two pharmacological inhibitors of MPO in a dextran sodium sulphate (DSS) model of murine colitis, we demonstrated the pathological role of MPO in experimental colitis. MPO inhibitors, TEMPOL and AZD3241 delivered via daily i.p significantly rescued the course of colitis by abrogating clinical indices including body weight loss, disease activity index, inhibiting serum peroxidation, and preserving colon length, while significantly mitigating histoarchitectural damage associated with DSS-induced colitis. We also showed that MPO inhibition decreased neutrophil migration to the gut, suggesting MPO may play a role in perpetuating the inflammatory cell by further recruiting cells to the inflamed gut. Collectively, we have shown for the first time that MPO is not only an important clinical marker of disease severity but may also play a critical role in perpetuating host-tissue damage and inflammation.

Efficient intramolecular general acid catalysis of the hydrolysis of a dialkyl acetal

1996 ◽  
pp. 2355 ◽  
Author(s):  
Christopher J. Brown ◽  
Anthony J. Kirby
Keyword(s):  
Acid Catalysis ◽  
General Acid ◽  
Hydrolysis Of

scholarly journals Glutathione Participation in the Prevention of Cardiovascular Diseases

Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1220
Author(s):  
Deyamira Matuz-Mares ◽  
Héctor Riveros-Rosas ◽  
María Magdalena Vilchis-Landeros ◽  
Héctor Vázquez-Meza
Keyword(s):  
Cardiovascular Diseases ◽  
Superoxide Anion ◽  
Reactive Nitrogen Species ◽  
Hypochlorous Acid ◽  
Reduced Glutathione ◽  
Heart Diseases ◽  
Reactive Species ◽  
Oxygen Species ◽  
Cardiovascular Pathologies

Cardiovascular diseases (CVD) (such as occlusion of the coronary arteries, hypertensive heart diseases and strokes) are diseases that generate thousands of patients with a high mortality rate worldwide. Many of these cardiovascular pathologies, during their development, generate a state of oxidative stress that leads to a deterioration in the patient’s conditions associated with the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS). Within these reactive species we find superoxide anion (O2•–), hydroxyl radical (•OH), nitric oxide (NO•), as well as other species of non-free radicals such as hydrogen peroxide (H2O2), hypochlorous acid (HClO) and peroxynitrite (ONOO–). A molecule that actively participates in counteracting the oxidizing effect of reactive species is reduced glutathione (GSH), a tripeptide that is present in all tissues and that its synthesis and/or regeneration is very important to be able to respond to the increase in oxidizing agents. In this review, we will address the role of glutathione, its synthesis in both the heart and the liver, and its importance in preventing or reducing deleterious ROS effects in cardiovascular diseases.

General acid catalysis in moderately concentrated aqueous sulphuric acid

1965 ◽  
Vol 39 ◽  
pp. 75 ◽  
Author(s):  
A. J. Kresge ◽  
L. E. Hakka ◽  
S. Mylonakis ◽  
Y. Sato
Keyword(s):  
Sulphuric Acid ◽  
Acid Catalysis ◽  
General Acid
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