Search results for "Catechol O-Methyltransferase"

Lack of association of a functional catechol-O-methyltransferase gene polymorphism with risk of tobacco smoking: results from a multicenter case-cont…

2013

Background The catechol-O-methyltransferase (COMT) modulates dopaminergic neurotransmission in the prefrontal cortex as well as in the mesolimbic reward system. Since the reward system mediates addictive behavior, the COMT gene is a strong candidate gene regarding the pathophysiology of tobacco dependence and smoking behavior. Because of rather conflicting results in previous studies, the purpose of the present study was to test for association between a functional genetic variant in the COMT gene (single nucleotide polymorphism [SNP] rs4680) and tobacco smoking behavior. Methods In a population-based case-control multicenter study designed for tobacco addiction research, a total of 551 cur…

The val158met polymorphism of human catechol-O-methyltransferase (COMT) affects anterior cingulate cortex activation in response to painful laser sti…

2010

Background: Pain is a complex experience with sensory, emotional and cognitive aspects. Genetic and environmental factors contribute to pain-related phenotypes such as chronic pain states. Genetic variations in the gene coding for catechol-O-methyltransferase ( COMT) have been suggested to affect clinical and experimental pain-related phenotypes including regional μ-opioid system responses to painful stimulation as measured by ligand-PET (positron emission tomography). The functional val158met single nucleotide polymorphism has been most widely studied. However, apart from its impact on pain-induced opioid release the effect of this genetic variation on cerebral pain processing has not been…

Gene-environment interaction as a predictor of early adjustment in first episode psychosis.

2017

Abstract Background This study aims to explore the gene-environment interaction hypothesis applied to pre-symptomatic neurodevelopmental phenotypes of first episode psychosis (FEP), that is, genetic factors might increase vulnerability to the effects of environmental adverse conditions occurring at later stages of development. Methods We constructed a schematic ‘two-hit’ model, with Val/Val homozygosity for the catechol- O -methyltransferase ( COMT ) Val158Met polymorphism as the ‘first hit’ and history of obstetric complications and parental socioeconomic status as ‘second hits’. Early adjustment, measured using the Premorbid Adjustment Scale, was considered the main outcome. The study pop…

The catechol-O-methyltransferase Val108/158Met polymorphism affects short-term treatment response to mirtazapine, but not to paroxetine in major depr…

2004

The catechol-O-methyltransferase (COMT) is a major degrading enzyme in the metabolic pathways of catecholaminergic neurotransmitters such as dopamine and norepinephrine. This study investigated whether the functionally relevant Val(108/158)Met gene variant is associated with differential antidepressant response to mirtazapine and/or paroxetine in 102 patients with major depression (DSM-IV criteria) participating in a randomized clinical trial with both drugs. In patients treated with mirtazapine, but not paroxetine, allelic variations in the COMT gene were associated with differential response. COMT(VAL/VAL) and COMT(VAL/MET) genotype carriers showed a better response than COMT(MET/MET)-bea…

COMT genotype predicts BOLD signal and noise characteristics in prefrontal circuits.

2006

Abstract Objective: Prefrontal dopamine (DA) is catabolized by the COMT (catechol- O -methyltransferase) enzyme. Literature suggests that the Val/Met single nucleotide polymorphism (SNP) in the COMT gene predicts executive cognition in humans with Val carriers showing poorer performance due to less available synaptic DA. Recent fMRI studies are thought to agree with these studies having demonstrated prefrontal hyperactivation during n -back and attention-requiring tasks. This was interpreted as “less efficient” processing due to impaired signal-to-noise ratio (SNR) of neuronal activity. However, electrophysiological studies of neuronal SNR in primates and humans imply that prefrontal cortex…

Interaction between gene variants of the serotonin transporter promoter region (5-HTTLPR) and catecholO-methyltransferase (COMT) in borderline person…

2008

Borderline personality disorder (BPD) is characterized by a heterogeneous symptomatology with instability in impulse control, interpersonal relationships and self-image. BPD patients display repeated self-injury, chronic suicidal tendencies and emotional dysregulation, mainly dysregulation of negative affect. In its etiology, genetic and environmental factors have been suggested. Recently, an investigation in male healthy volunteers found gene–gene effects of the catechol-O-methyl-transferase (COMT) low-activity (Met158) and the low-expression allele of the deletion/insertion (short/long or S/L, respectively) polymorphism in the serotonin transporter-linked promoter region (5-HTTLPR) on the…

Lack of modulating effects of the COMT Val158Met polymorphism on the association of serious life events (SLE) and impulsivity in patients with Border…

2009

CB1 cannabinoid receptor-mediated aggressive behavior

2013

This study examined the role of cannabinoid CB1 receptors (CB1r) in aggressive behavior. Social encounters took place in grouped and isolated mice lacking CB1r (CB1KO) and in wild-type (WT) littermates. Cognitive impulsivity was evaluated in the delayed reinforcement task (DRT). Gene expression analyses of monoaminooxidase-A (MAO-A), catechol-o-methyl-transferase (COMT), 5-hydroxytriptamine transporter (5-HTT) and 5-HT1B serotonergic receptor (5HT1Br) in the median and dorsal raphe nuclei (MnR and DR, respectively) and in the amygdala (AMY) were performed by real time-PCR. Double immunohistochemistry studies evaluated COMT and CB1r co-localization in the raphe nuclei and in the cortical (AC…

Catechol-O-Methyltransferase (COMT) Val158Met Polymorphism and Eating Disorders: Data From a New Biobank and Meta-Analysis of Previously Published St…

2017

Objectives: We investigated whether catechol-O-methyltransferase (COMT) Val158Met polymorphism is associated with eating disorders (EDs). Methods: We conducted a systematic literature search of studies published until 15 January 2017 and added data from the Italian ‘Biobanca Veneta per i Disturbi Alimentari’ biobank, performing a meta-analysis comparing COMT Val158Met genotype and allele frequencies in EDs and anorexia nervosa (AN) or bulimia nervosa (BN) patients versus controls. Results: Ten studies plus Biobanca Veneta per i Disturbi Alimentari (ED: n = 920, controls: n = 261 controls) with 3541 ED patients (AN = 2388; BN = 233) and 3684 controls were included. There were no significant …

Hybrid Quantum Mechanics/Molecular Mechanics Simulations with Two-Dimensional Interpolated Corrections:  Application to Enzymatic Processes

2006

Hybrid quantum mechanics/molecular mechanics (QM/MM) techniques are widely used to study chemical reactions in large systems. Because of the computational cost associated with the high dimensionality of these systems, the quantum description is usually restricted to low-level methods, such as semiempirical Hamiltonians. In some cases, the description obtained at this computational level is quite poor and corrections must be considered. We here propose a simple but efficient way to include higher-level corrections to be used in potential energy surface explorations and in the calculation of potentials of mean force. We evaluate a correction energy term as the difference between a high-level …