The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
Ruud B Minderaa - One of the best experts on this subject based on the ideXlab platform.
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Plasma Kynurenine and related measures in tic disorder patients
European Child & Adolescent Psychiatry, 2007Co-Authors: Pieter J Hoekstra, Pieter W Troost, George M. Anderson, Cees G M Kallenberg, Ruud B MinderaaAbstract:Objective Increased plasma Kynurenine has been reported in tic disorder patients, and this observation has been suggested to be indicative of immune dysregulation. In the present study, we examined plasma levels of Kynurenine and related molecules in a group of tic disorder patients. Methods Plasma concentrations of tryptophan, Kynurenine, cortisol, and neopterin were determined in Dutch tic disorder patients (N = 59), and healthy volunteers (N = 32). Group means were compared and age-controlled intra-individual correlations between tic severity and plasma levels of these molecules were examined. Results No significant differences were found between patient and control groups in plasma levels of tryptophan, Kynurenine, and cortisol concentrations, nor in the Kynurenine/tryptophan ratio. However, neopterin was significantly (p = 0.035) higher in patients (mean = 5.13 nmol/1) than in controls (mean = 3.30 nmol/1). Plasma levels of these molecules did not correlate with tic severity, with the exception of tryptophan (r = -0.289, p = 0.049). In patients, plasma neopterin correlated with Kynurenine (r = 0.438, P = 0.002); in healthy subjects, tryptophan correlated with Kynurenine (r = 0.670, p
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Plasma Kynurenine and related measures in tic disorder patients.
European child & adolescent psychiatry, 2007Co-Authors: Pieter J Hoekstra, Pieter W Troost, George M. Anderson, Cees G M Kallenberg, Ruud B MinderaaAbstract:Increased plasma Kynurenine has been reported in tic disorder patients, and this observation has been suggested to be indicative of immune dysregulation. In the present study, we examined plasma levels of Kynurenine and related molecules in a group of tic disorder patients. Plasma concentrations of tryptophan, Kynurenine, cortisol, and neopterin were determined in Dutch tic disorder patients (N = 59), and healthy volunteers (N = 32). Group means were compared and age-controlled intra-individual correlations between tic severity and plasma levels of these molecules were examined. No significant differences were found between patient and control groups in plasma levels of tryptophan, Kynurenine, and cortisol concentrations, nor in the Kynurenine/tryptophan ratio. However, neopterin was significantly (p = 0.035) higher in patients (mean = 5.13 nmol/l) than in controls (mean = 3.30 nmol/l). Plasma levels of these molecules did not correlate with tic severity, with the exception of tryptophan (r = -0.289, p = 0.049). In patients, plasma neopterin correlated with Kynurenine (r = 0.438, p = 0.002); in healthy subjects, tryptophan correlated with Kynurenine (r = 0.670, p < 0.001). While the observed elevation in plasma neopterin is consistent with immune activation in a subset of tic disorder patients, metabolism of tryptophan through the Kynurenine pathway appears to be unaltered in tic disorder patients.
Pieter J Hoekstra - One of the best experts on this subject based on the ideXlab platform.
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Plasma Kynurenine and related measures in tic disorder patients
European Child & Adolescent Psychiatry, 2007Co-Authors: Pieter J Hoekstra, Pieter W Troost, George M. Anderson, Cees G M Kallenberg, Ruud B MinderaaAbstract:Objective Increased plasma Kynurenine has been reported in tic disorder patients, and this observation has been suggested to be indicative of immune dysregulation. In the present study, we examined plasma levels of Kynurenine and related molecules in a group of tic disorder patients. Methods Plasma concentrations of tryptophan, Kynurenine, cortisol, and neopterin were determined in Dutch tic disorder patients (N = 59), and healthy volunteers (N = 32). Group means were compared and age-controlled intra-individual correlations between tic severity and plasma levels of these molecules were examined. Results No significant differences were found between patient and control groups in plasma levels of tryptophan, Kynurenine, and cortisol concentrations, nor in the Kynurenine/tryptophan ratio. However, neopterin was significantly (p = 0.035) higher in patients (mean = 5.13 nmol/1) than in controls (mean = 3.30 nmol/1). Plasma levels of these molecules did not correlate with tic severity, with the exception of tryptophan (r = -0.289, p = 0.049). In patients, plasma neopterin correlated with Kynurenine (r = 0.438, P = 0.002); in healthy subjects, tryptophan correlated with Kynurenine (r = 0.670, p
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Plasma Kynurenine and related measures in tic disorder patients.
European child & adolescent psychiatry, 2007Co-Authors: Pieter J Hoekstra, Pieter W Troost, George M. Anderson, Cees G M Kallenberg, Ruud B MinderaaAbstract:Increased plasma Kynurenine has been reported in tic disorder patients, and this observation has been suggested to be indicative of immune dysregulation. In the present study, we examined plasma levels of Kynurenine and related molecules in a group of tic disorder patients. Plasma concentrations of tryptophan, Kynurenine, cortisol, and neopterin were determined in Dutch tic disorder patients (N = 59), and healthy volunteers (N = 32). Group means were compared and age-controlled intra-individual correlations between tic severity and plasma levels of these molecules were examined. No significant differences were found between patient and control groups in plasma levels of tryptophan, Kynurenine, and cortisol concentrations, nor in the Kynurenine/tryptophan ratio. However, neopterin was significantly (p = 0.035) higher in patients (mean = 5.13 nmol/l) than in controls (mean = 3.30 nmol/l). Plasma levels of these molecules did not correlate with tic severity, with the exception of tryptophan (r = -0.289, p = 0.049). In patients, plasma neopterin correlated with Kynurenine (r = 0.438, p = 0.002); in healthy subjects, tryptophan correlated with Kynurenine (r = 0.670, p < 0.001). While the observed elevation in plasma neopterin is consistent with immune activation in a subset of tic disorder patients, metabolism of tryptophan through the Kynurenine pathway appears to be unaltered in tic disorder patients.
László Vécsei - One of the best experts on this subject based on the ideXlab platform.
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Changing the Face of Kynurenines and Neurotoxicity: Therapeutic Considerations
International journal of molecular sciences, 2015Co-Authors: Zsuzsanna Bohár, József Toldi, Ferenc Fülöp, László VécseiAbstract:Kynurenines are the products of tryptophan metabolism. Among them, Kynurenine and kynurenic acid are generally thought to have neuroprotective properties, while 3-hydroxyKynurenine, 3-hydroxyanthranilic acid and quinolinic acid are considered neurotoxic. They participate in immunoregulation and inflammation and possess pro- or anti-excitotoxic properties, and their involvement in oxidative stress has also been suggested. Consequently, it is not surprising that Kynurenines have been closely related to neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis and multiple sclerosis. More information about the less-known metabolites, picolinic and cinnabarinic acid, evaluation of new receptorial targets, such as aryl-hydrocarbon receptors, and intensive research on the field of the immunomodulatory function of Kynurenines delineated the high importance of this pathway in general homeostasis. Emerging knowledge about the Kynurenine pathway provides new target points for the development of therapeutical solutions against neurodegenerative diseases.
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The Role of the Kynurenine Pathway in Neurodegenerative Diseases
Targeting the Broadly Pathogenic Kynurenine Pathway, 2015Co-Authors: Zsófi A. Majláth, József Toldi, László VécseiAbstract:The Kynurenine pathway, the main metabolic route of tryptophan degradation, produces several neuroactive molecules. Alterations in the Kynurenine pathway have been described in a number of neurological disorders; a feature of special importance is the elevation of neurotoxic metabolites, which may promote glutamate-mediated excitotoxic neuronal damage. The delicate balance between the neurotoxic and neuroprotective compounds participating in the Kynurenine pathway has been suggested to play an important role in the regulation of glutamatergic neurotransmission and in inflammatory processes. Synthetic kynurenic acid derivatives and Kynurenine-monooxygenase inhibitors have proved in several preclinical studies to have beneficial effects. The Kynurenine pathway offers a promising target for future drug development with the aim of achieving neuroprotection.
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The Kynurenine system and immunoregulation
Journal of neural transmission (Vienna Austria : 1996), 2011Co-Authors: Yvette Mándi, László VécseiAbstract:There is developing interest in the role of the Kynurenines in the immune function. A considerable amount of evidence has accumulated as concerns interactions between the Kynurenine pathway, cytokines and the nervous system. Indoleamine 2,3-dioxygenase (IDO) occupies a key position connecting the immune system and the Kynurenine pathway. There are evidences of the immunosuppressive effect of IDO. Following the interferon (IFN)-mediated activation of antigen presenting cells, the induction of IDO and the Kynurenine system exerts a counter-regulating effect, maintaining the homeostasis. Inhibition of T cell functions, activation of the regulatory T cells, and the inhibition of Natural Killer cells are among the important factors in the immunosuppressive effects of IDO and Kynurenines. There is a close connection between cytokines (IFN-α, IFN-γ, TNF-α, TGF-β, IL-4 and IL-23) and the Kynurenine system, and an imbalance in the TH1/TH2 cytokine profile may possibly lead to neurologic or psychiatric disorders. As the tryptophan metabolic pathway is activated by pro-inflammatory stimuli, the anti-inflammatory effect of kynurenic acid provides a further feedback mechanism in modulating the immune responses.
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Kynurenines and headache
Journal of neural transmission (Vienna Austria : 1996), 2011Co-Authors: Árpád Párdutz, József Toldi, Zsuzsanna Bohár, Annamária Fejes, Lilla Tar, László VécseiAbstract:In parallel to serotonin synthesis, the major route of tryptophan catabolism is the Kynurenine pathway, which produces neuroactive metabolites. Among these substances, kynurenic acid has potential neuroprotective action blocking glutamate release and glutamatergic neurotransmission. Glutamate is a key player in migraine pathogenesis; it is crucial in the communication of first and second-order neurons, and it has an important role in the genesis of cortical spreading depression, which is the electrophysiological correlate for migraine aura and may be involved in the activation of the trigeminal system. Thus, Kynurenines may affect the pathogenesis directly, by acting on glutamate receptors and exerting other neuromodulatory effects, and indirectly via an altered serotonin metabolism. This work summarizes our current results regarding the role of the Kynurenine system in trigeminal activation and other events occurring during migraine headache.
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Kynurenines in chronic neurodegenerative disorders: future therapeutic strategies
Journal of Neural Transmission, 2009Co-Authors: D. Zádori, József Toldi, P. Klivényi, E. Vámos, F. Fülöp, László VécseiAbstract:Parkinson’s, Alzheimer’s and Huntington’s diseases are chronic neurodegenerative disorders of a progressive nature which lead to a considerable deterioration of the quality of life. Their pathomechanisms display some common features, including an imbalance of the tryptophan metabolism. Alterations in the concentrations of neuroactive Kynurenines can be accompanied by devastating excitotoxic injuries and metabolic disturbances. From therapeutic considerations, possibilities that come into account include increasing the neuroprotective effect of kynurenic acid, or decreasing the levels of neurotoxic 3-hydroxy- l -Kynurenine and quinolinic acid. The experimental data indicate that neuroprotection can be achieved by both alternatives, suggesting opportunities for further drug development in this field.
Pieter W Troost - One of the best experts on this subject based on the ideXlab platform.
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Plasma Kynurenine and related measures in tic disorder patients
European Child & Adolescent Psychiatry, 2007Co-Authors: Pieter J Hoekstra, Pieter W Troost, George M. Anderson, Cees G M Kallenberg, Ruud B MinderaaAbstract:Objective Increased plasma Kynurenine has been reported in tic disorder patients, and this observation has been suggested to be indicative of immune dysregulation. In the present study, we examined plasma levels of Kynurenine and related molecules in a group of tic disorder patients. Methods Plasma concentrations of tryptophan, Kynurenine, cortisol, and neopterin were determined in Dutch tic disorder patients (N = 59), and healthy volunteers (N = 32). Group means were compared and age-controlled intra-individual correlations between tic severity and plasma levels of these molecules were examined. Results No significant differences were found between patient and control groups in plasma levels of tryptophan, Kynurenine, and cortisol concentrations, nor in the Kynurenine/tryptophan ratio. However, neopterin was significantly (p = 0.035) higher in patients (mean = 5.13 nmol/1) than in controls (mean = 3.30 nmol/1). Plasma levels of these molecules did not correlate with tic severity, with the exception of tryptophan (r = -0.289, p = 0.049). In patients, plasma neopterin correlated with Kynurenine (r = 0.438, P = 0.002); in healthy subjects, tryptophan correlated with Kynurenine (r = 0.670, p
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Plasma Kynurenine and related measures in tic disorder patients.
European child & adolescent psychiatry, 2007Co-Authors: Pieter J Hoekstra, Pieter W Troost, George M. Anderson, Cees G M Kallenberg, Ruud B MinderaaAbstract:Increased plasma Kynurenine has been reported in tic disorder patients, and this observation has been suggested to be indicative of immune dysregulation. In the present study, we examined plasma levels of Kynurenine and related molecules in a group of tic disorder patients. Plasma concentrations of tryptophan, Kynurenine, cortisol, and neopterin were determined in Dutch tic disorder patients (N = 59), and healthy volunteers (N = 32). Group means were compared and age-controlled intra-individual correlations between tic severity and plasma levels of these molecules were examined. No significant differences were found between patient and control groups in plasma levels of tryptophan, Kynurenine, and cortisol concentrations, nor in the Kynurenine/tryptophan ratio. However, neopterin was significantly (p = 0.035) higher in patients (mean = 5.13 nmol/l) than in controls (mean = 3.30 nmol/l). Plasma levels of these molecules did not correlate with tic severity, with the exception of tryptophan (r = -0.289, p = 0.049). In patients, plasma neopterin correlated with Kynurenine (r = 0.438, p = 0.002); in healthy subjects, tryptophan correlated with Kynurenine (r = 0.670, p < 0.001). While the observed elevation in plasma neopterin is consistent with immune activation in a subset of tic disorder patients, metabolism of tryptophan through the Kynurenine pathway appears to be unaltered in tic disorder patients.
George M. Anderson - One of the best experts on this subject based on the ideXlab platform.
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Plasma Kynurenine and related measures in tic disorder patients
European Child & Adolescent Psychiatry, 2007Co-Authors: Pieter J Hoekstra, Pieter W Troost, George M. Anderson, Cees G M Kallenberg, Ruud B MinderaaAbstract:Objective Increased plasma Kynurenine has been reported in tic disorder patients, and this observation has been suggested to be indicative of immune dysregulation. In the present study, we examined plasma levels of Kynurenine and related molecules in a group of tic disorder patients. Methods Plasma concentrations of tryptophan, Kynurenine, cortisol, and neopterin were determined in Dutch tic disorder patients (N = 59), and healthy volunteers (N = 32). Group means were compared and age-controlled intra-individual correlations between tic severity and plasma levels of these molecules were examined. Results No significant differences were found between patient and control groups in plasma levels of tryptophan, Kynurenine, and cortisol concentrations, nor in the Kynurenine/tryptophan ratio. However, neopterin was significantly (p = 0.035) higher in patients (mean = 5.13 nmol/1) than in controls (mean = 3.30 nmol/1). Plasma levels of these molecules did not correlate with tic severity, with the exception of tryptophan (r = -0.289, p = 0.049). In patients, plasma neopterin correlated with Kynurenine (r = 0.438, P = 0.002); in healthy subjects, tryptophan correlated with Kynurenine (r = 0.670, p
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Plasma Kynurenine and related measures in tic disorder patients.
European child & adolescent psychiatry, 2007Co-Authors: Pieter J Hoekstra, Pieter W Troost, George M. Anderson, Cees G M Kallenberg, Ruud B MinderaaAbstract:Increased plasma Kynurenine has been reported in tic disorder patients, and this observation has been suggested to be indicative of immune dysregulation. In the present study, we examined plasma levels of Kynurenine and related molecules in a group of tic disorder patients. Plasma concentrations of tryptophan, Kynurenine, cortisol, and neopterin were determined in Dutch tic disorder patients (N = 59), and healthy volunteers (N = 32). Group means were compared and age-controlled intra-individual correlations between tic severity and plasma levels of these molecules were examined. No significant differences were found between patient and control groups in plasma levels of tryptophan, Kynurenine, and cortisol concentrations, nor in the Kynurenine/tryptophan ratio. However, neopterin was significantly (p = 0.035) higher in patients (mean = 5.13 nmol/l) than in controls (mean = 3.30 nmol/l). Plasma levels of these molecules did not correlate with tic severity, with the exception of tryptophan (r = -0.289, p = 0.049). In patients, plasma neopterin correlated with Kynurenine (r = 0.438, p = 0.002); in healthy subjects, tryptophan correlated with Kynurenine (r = 0.670, p < 0.001). While the observed elevation in plasma neopterin is consistent with immune activation in a subset of tic disorder patients, metabolism of tryptophan through the Kynurenine pathway appears to be unaltered in tic disorder patients.
