The Experts below are selected from a list of 60 Experts worldwide ranked by ideXlab platform

Kevin P. Moore - One of the best experts on this subject based on the ideXlab platform.

  • Making and working with hydrogen sulfide. The chemistry and generation of hydrogen sulfide in vitro and its measurement in vivo: A review
    Free Radical Biology and Medicine, 2009
    Co-Authors: Martin N. Hughes, Miguel N. Centelles, Kevin P. Moore
    Abstract:

    Hydrogen sulfide is rapidly emerging as an important Vasoactive Mediator formed in health and disease. Its biological action is centered on its reactivity with heme-proteins and its ability to activate K ATP channels. Hydrogen sulfide is a signalling molecule of the inflammatory and nervous systems, and in particular the cardiovascular system where it regulates vascular tone, cardiac work, and exerts cardioprotection. This has led to an explosion of papers in which the role of hydrogen sulfide generated in vitro has been used to stimulate biological responses, and where a variety of methods have been used to measure the concentration of this compound in biological fluids. Understanding the chemistry and the inherent problems in the analytical techniques used to measure hydrogen sulfide concentrations is critical to our expanding knowledge on the biology of hydrogen sulfide. In this brief review we will cover the chemistry of hydrogen sulfide, including sources of hydrogen sulfide, its speciation at physiological pH, the susceptibility of sulfide to aerobic oxidation, and the methods used to measure hydrogen sulfide concentrations in solution, including biological fluids. We also give a brief overview of knockout animals and inhibition of the enzymes involved in the formation of hydrogen sulfide in vivo. © 2009 Elsevier Inc. All rights reserved.

William Kemp - One of the best experts on this subject based on the ideXlab platform.

  • urotensin ii a novel Vasoactive Mediator linked to chronic liver disease and portal hypertension
    Liver International, 2007
    Co-Authors: William Kemp, Henry Krum, John Colman, Michael Bailey, T G Yandle, Mark Richards, Stuart K. Roberts
    Abstract:

    Background/Aims: Urotensin II (UII) is recognised as the most potent human vasoconstrictor; however, its role in chronic liver disease (CLD) is unknown. Aim: We sought to determine serum UII levels in CLD and explore its relationship with clinical features and outcomes of patients with CLD and portal hypertension. Methods: UII was analysed by radio-immunoassay on cirrhotic patients undergoing hepatic venous pressure gradient (HVPG) determination and age- and sex-matched controls. Follow-up data were prospectively recorded. Results: From 1997 to 2004, 80 patients (male/female: 74/6) underwent a total of 94 HVPG assessments. UII was higher in cirrhotic patients compared with controls (2.05±0.06 and 1.55±0.09 pmol/L, P<0.001) and was correlated with HVPG (r=+0.35, P=0.001) and severity of CLD (r=+0.6, P<0.001). UII was higher in patients who developed refractory ascites (2.45±0.13 vs. 1.7±0.12 pmol/L, P<0.001) and in those who died during the follow-up period (2.27±0.15 pmol/L vs. 1.95±0.08 pmol/L, P<0.05). Conclusion: Serum UII is elevated in patients with CLD, and is associated with the severity of the underlying liver disease and the degree of portal hypertension. Baseline levels can predict future complications such as refractory ascites and patient survival.

  • Increased circulating urotensin II in cirrhosis: potential implications in liver disease.
    Peptides, 2007
    Co-Authors: William Kemp, Stuart K. Roberts, Henry Krum
    Abstract:

    Urotensin II (UII) is a potent Vasoactive Mediator which, through interaction with a specific G-protein coupled receptor, can result in either a vasoconstrictive or vasodilatory response. In addition to its effect upon vascular tone, UII possess mitogenic and fibrogenic potential. The influence of UII on vascular tone is to some degree both species-specific and disease-specific. Increased circulating UII levels have been documented in subjects with liver cirrhosis although the significance of this finding with regards to the development of chronic liver disease and portal hypertension has yet to be fully elucidated. In this review we focus on the potential relevance of UII as a Vasoactive Mediator in the chronic liver disease population and postulate as to the site of overproduction of UII.

Stuart K. Roberts - One of the best experts on this subject based on the ideXlab platform.

  • urotensin ii a novel Vasoactive Mediator linked to chronic liver disease and portal hypertension
    Liver International, 2007
    Co-Authors: William Kemp, Henry Krum, John Colman, Michael Bailey, T G Yandle, Mark Richards, Stuart K. Roberts
    Abstract:

    Background/Aims: Urotensin II (UII) is recognised as the most potent human vasoconstrictor; however, its role in chronic liver disease (CLD) is unknown. Aim: We sought to determine serum UII levels in CLD and explore its relationship with clinical features and outcomes of patients with CLD and portal hypertension. Methods: UII was analysed by radio-immunoassay on cirrhotic patients undergoing hepatic venous pressure gradient (HVPG) determination and age- and sex-matched controls. Follow-up data were prospectively recorded. Results: From 1997 to 2004, 80 patients (male/female: 74/6) underwent a total of 94 HVPG assessments. UII was higher in cirrhotic patients compared with controls (2.05±0.06 and 1.55±0.09 pmol/L, P<0.001) and was correlated with HVPG (r=+0.35, P=0.001) and severity of CLD (r=+0.6, P<0.001). UII was higher in patients who developed refractory ascites (2.45±0.13 vs. 1.7±0.12 pmol/L, P<0.001) and in those who died during the follow-up period (2.27±0.15 pmol/L vs. 1.95±0.08 pmol/L, P<0.05). Conclusion: Serum UII is elevated in patients with CLD, and is associated with the severity of the underlying liver disease and the degree of portal hypertension. Baseline levels can predict future complications such as refractory ascites and patient survival.

  • Increased circulating urotensin II in cirrhosis: potential implications in liver disease.
    Peptides, 2007
    Co-Authors: William Kemp, Stuart K. Roberts, Henry Krum
    Abstract:

    Urotensin II (UII) is a potent Vasoactive Mediator which, through interaction with a specific G-protein coupled receptor, can result in either a vasoconstrictive or vasodilatory response. In addition to its effect upon vascular tone, UII possess mitogenic and fibrogenic potential. The influence of UII on vascular tone is to some degree both species-specific and disease-specific. Increased circulating UII levels have been documented in subjects with liver cirrhosis although the significance of this finding with regards to the development of chronic liver disease and portal hypertension has yet to be fully elucidated. In this review we focus on the potential relevance of UII as a Vasoactive Mediator in the chronic liver disease population and postulate as to the site of overproduction of UII.

Martin N. Hughes - One of the best experts on this subject based on the ideXlab platform.

  • Making and working with hydrogen sulfide. The chemistry and generation of hydrogen sulfide in vitro and its measurement in vivo: A review
    Free Radical Biology and Medicine, 2009
    Co-Authors: Martin N. Hughes, Miguel N. Centelles, Kevin P. Moore
    Abstract:

    Hydrogen sulfide is rapidly emerging as an important Vasoactive Mediator formed in health and disease. Its biological action is centered on its reactivity with heme-proteins and its ability to activate K ATP channels. Hydrogen sulfide is a signalling molecule of the inflammatory and nervous systems, and in particular the cardiovascular system where it regulates vascular tone, cardiac work, and exerts cardioprotection. This has led to an explosion of papers in which the role of hydrogen sulfide generated in vitro has been used to stimulate biological responses, and where a variety of methods have been used to measure the concentration of this compound in biological fluids. Understanding the chemistry and the inherent problems in the analytical techniques used to measure hydrogen sulfide concentrations is critical to our expanding knowledge on the biology of hydrogen sulfide. In this brief review we will cover the chemistry of hydrogen sulfide, including sources of hydrogen sulfide, its speciation at physiological pH, the susceptibility of sulfide to aerobic oxidation, and the methods used to measure hydrogen sulfide concentrations in solution, including biological fluids. We also give a brief overview of knockout animals and inhibition of the enzymes involved in the formation of hydrogen sulfide in vivo. © 2009 Elsevier Inc. All rights reserved.

J Elliott - One of the best experts on this subject based on the ideXlab platform.