Search results for "PAM"
showing 10 items of 1768 documents
Association of Low Striatal Dopamine D2Receptor Availability With Nicotine Dependence Similar to That Seen With Other Drugs of Abuse
2008
All drugs of abuse induce a phasic dopamine release within the striatum that does not undergo habituation. Prolonged substance consumption impairs the natural function of the mesolimbic dopamine system, as shown by a decrease in the availability of striatal dopamine 2 (D(2)) receptors in patients suffering from cocaine, heroin, amphetamine, and alcohol dependence. However, it is unclear whether similar changes can also be observed in heavy-smoking nicotine-dependent smokers.In vivo D(2)/D(3) receptor availability was determined with [ (18)F]fallypride positron emission tomography in 17 heavy-smoking nicotine-dependent subjects and in 21 age-matched never-smoking comparison subjects. The smo…
Increased Neural Activity in Mesostriatal Regions after Prefrontal Transcranial Direct Current Stimulation and L-DOPA Administration
2019
Dopamine dysfunction is associated with a wide range of neuropsychiatric disorders commonly treated pharmacologically or invasively. Recent studies provide evidence for a nonpharmacological and noninvasive alternative that allows similar manipulation of the dopaminergic system: transcranial direct current stimulation (tDCS). In rodents, tDCS has been shown to increase neural activity in subcortical parts of the dopaminergic system, and recent studies in humans provide evidence that tDCS over prefrontal regions induces striatal dopamine release and affects reward-related behavior. Based on these findings, we used fMRI in healthy human participants and measured the fractional amplitude of low…
Catecholamine release in human skin--a microdialysis study.
2003
Dermal microdialysis might be a promising tool to investigate properties of sympathetic neurons in the skin as investigation of peripheral noradrenergic neurons in humans usually relies on highly variable vasoconstrictor reflexes or on indirect measurements like skin temperature recordings. To evaluate this technique, 21 experiments were performed in 15 healthy subjects with four intracutaneous microdialysis fibers (diameter, 200 microm; cutoff, 5 kDa) at hands or feet. After 60 min, saline perfusion tyramine at concentrations of 0.195 to 200 microg/ml was applied for 15 min followed by a 15-min saline perfusion again. Catecholamine concentrations were detected through high-performance liqu…
High striatal occupancy of D2-like dopamine receptors by amisulpride in the brain of patients with schizophrenia.
2003
The 'atypicality' of the antipsychotic drug, amisulpride, has been attributed to preferential extrastriatal binding. Previous investigations of striatal D2 receptor occupancy by amisulpride revealed conflicting results. The aim of this PET study was to measure the striatal occupancy by amisulpride and to correlate it with the corresponding drug plasma concentrations. Nine amisulpride-treated patients and 12 healthy volunteers serving as controls were studied with PET and [18F]desmethoxyfallypride. Occupancy values and plasma concentrations were nonlinearly fitted to an E max model. Results showed 43-85% (putamen) and 67-90% (caudate) D2-like receptor occupancy. Plasma amisulpride concentrat…
Dopamine D2 Receptor Occupancy Estimated From Plasma Concentrations of Four Different Antipsychotics and the Subjective Experience of Physical and Me…
2019
Background Impaired subjective well-being in schizophrenia patients treated with antipsychotics has often been linked inter alia to the antidopaminergic effects of medication. Thus, it is important to capture the association between striatal dopamine D2 receptor occupancy (D2-RO) and global subjective well-being. We examined this association using data from our multicenter, randomized, double-blind Neuroleptic Strategy Study (NeSSy). Methods An innovative double randomization process was used for allocation of patients to the specific treatment groups. Plasma drug concentrations were measured after 6 and 24 weeks of treatment to obtain the estimated D2-RO (eD2-RO) relative to literature val…
Association of functional DBH genetic variants with alcohol dependence risk and related depression and suicide attempt phenotypes: Results from a lar…
2012
Abstract Objective Dopamine-beta-hydroxylase (DBH) metabolizes the conversion of dopamine to noradrenaline. DBH, located on chromosome 9q34.2 has variants with potential functional consequences which may be related to alterations of neurotransmitter function and several psychiatric phenotypes, including alcohol dependence (AD), depression (MD) and suicidal behavior (SA). The aim of this association study in a large multicenter sample of alcohol-dependent individuals and controls is to investigate the role of DBH SNPs and haplotypes in AD risk and associated phenotypes (AD with MD or SA). Method 1606 inpatient subjects with DSM-IV AD from four addiction treatment centers and 1866 control sub…
Effect of Sirolimus Exposure on the Need for Preemptive Antiviral Therapy for Cytomeglovirus Infection after Allogeneic Hematopoietic Stem Cell Trans…
2019
The current study evaluates the clinical effect of sirolimus exposure on the occurrence of cytomegalovirus (CMV) DNAemia necessitating preemptive antiviral therapy. A total of 167 consecutive recipients of reduced-intensity conditioning (RIC) allogeneic hematopoietic stem cell transplantation (allo-HSCT) who received sirolimus- and tacrolimus-based graft-versus-host disease (GVHD) prophylaxis and whose CMV serostatus was positive for donors and/or recipients were included in this multicenter retrospective study. A parametric model with consecutive sirolimus blood levels describing the time to CMV DNAemia-RAT was developed using NONMEM version 7.4. Overall, 122 of 167 patients (73%) were all…
Differences in the topographical distribution of EEG activity during surgical anaesthesia and on emergence from volatile anesthetics.
1994
Computerized processing of a 16 channel EEG allows mapping and display of cortical electrical activity in a useful mode for intraoperative monitoring. We studied the topographical distribution of EEG-activity displayed as spectral maps comparing inhalational anaesthesia with isoflurane or enflurane during surgical anaesthesia and emergence. Two groups of nine patients each were anaesthetized with one of the two regimens. The EEG patterns during steady state end-tidal concentrations of isoflurane (0.7-1.1%) or enflurane (0.8-1.3%) showed highest activity in the frontal and occipital areas. At near awakening the frontal and occipital dominance of delta activity disappeared in both groups and …
Savoxepine: invalidation of an "atypical" neuroleptic response pattern predicted by animal models in an open clinical trial with schizophrenic patien…
1991
The new tetracyclic compound savoxepine exhibits potent antidopaminergic effects with preferential activity in the hippocampus as compared to striatum in rat brain. As a result of behavioural animal models and regional differences in dopamine receptor binding characteristics, it has been suggested to possess an "atypical" neuroleptic response pattern. In an open clinical trial, savoxepine was administered to 12 in-patients suffering from paranoid schizophrenia and schizophreniform disorder (DSM-III). Eight patients were treated with a stable dose of 0.5 mg per day throughout the study, while in the remaining patients higher doses up to 20 mg/day were administered. Mean total BPRS scores and…
Impact of NTRK2, DRD2 and ACE polymorphisms on prolactin levels in antipsychotic-treated patients with first-episode psychosis.
2018
Background: Hyperprolactinemia is a common side-effect of antipsychotics (APs), which may trigger serious secondary problems and compromise the adherence to treatment which is crucial for prognosis, especially in patients presenting with a first-episode of psychosis (FEP). Aims: We evaluated, in some cases for the first time, the effect of polymorphisms in multiple candidate genes on serum prolactin (PRL) levels in an AP-treated FEP cohort recruited in the multicenter PEPs study (Phenotype − genotype and environmental interaction; Application of a predictive model in first psychotic episodes). Methods: PRL concentration was measured in serum from 222 patients. A total of 167 polymorphisms w…