Search results for "double"
showing 10 items of 2879 documents
Serotonergic modulation of response inhibition and re-engagement? Results of a study in healthy human volunteers
2010
Objective Cognitive functions dependent on the prefrontal cortex, such as the ability to suppress behavior (response inhibition) and initiate a new one (response re-engagement) is important in the activities of daily life. Central serotonin (5-HT) function is thought to be a critical component of these cognitive functions. In recent studies, 5-HT failed to affect stop-signal reaction time (SSRT), a fundamental process in behavioral inhibition. We were interested if response inhibition and re-engagement are influenced through central 5-HT activity as mediated via the 5-HT transporter. Methods Here, using a stop-change task, we investigated the effects of acute and repeated treatment with 10 …
Early and late histamine release induced by albumin, hetastarch and polygeline: some unexpected findings.
2003
Objective: The perioperative use of colloidal plasma substitutes is still under discussion. We therefore conducted a prospective randomised study with three commonly used plasma substitutes to examine their histamine releasing effects in 21 volunteers. Material or subjects: 21 male volunteers were enrolled in this prospective, randomised, controlled clinical study. Endpoints were the incidence of early and late histamine release and the time course of the release kinetics. Normovolemic hemodilution technique was used with hydroxyethyl starch (n = 6), human albumin (n = 6) and polygeline (n = 9). Measurement and observation period was 240 min after the start of the plasma substitute infusion…
Lipid-altering efficacy of ezetimibe/simvastatin 10/20 mg compared with rosuvastatin 10 mg in high-risk hypercholesterolaemic patients inadequately c…
2009
SUMMARY Aims: To evaluate the efficacy of switching from a previous statin monotherapy to ezetimibe ⁄simvastatin (EZE ⁄SIMVA) 10 ⁄20 mg vs. rosuvastatin (ROSUVA) 10 mg. Methods: In this randomised, double-blind study, 618 patients with documented hypercholesterolaemia [low-density lipoprotein cholesterol (LDL-C) ‡ 2.59 and £ 4.92 mmol ⁄l] and with high cardiovascular risk who were taking a stable daily dose of one of several statin medications for ‡ 6 weeks prior to the study randomisation visit entered a 6-week open-label stabilisation ⁄screening period during which they continued to receive their prestudy statin dose. Following stratification by study site and statin dose ⁄potency, patien…
S-Ketamine-Induced NMDA Receptor Blockade during Natural Speech Production and Its Implications for Formal Thought Disorder in Schizophrenia: A Pharm…
2017
Structural and functional changes in the lateral temporal language areas have been related to formal thought disorder (FTD) in schizophrenia. Continuous, natural speech production activates the right lateral temporal lobe in schizophrenia, as opposed to the left in healthy subjects. Positive and negative FTD can be elicited in healthy subjects by glutamatergic NMDA blockade with ketamine. It is unclear whether the glutamate system is related to the reversed hemispheric lateralization during speaking in patients. In a double-blind, crossover, placebo-controlled study, 15 healthy, male, right-handed volunteers overtly described 7 pictures for 3 min each while BOLD signal changes were acquired…
Beta-adrenergic stimulation enhances left ventricular diastolic performance in normal subjects.
1997
To determine the effects of beta-adrenergic stimulation on transmitral Doppler echocardiography flow characteristics of left ventricular diastolic filling, we studied 10 healthy volunteers aged 23-31 years (mean age, 26.6 years) during intravenous infusion of isoprenaline in consecutive steps of 0.1, 0.2, 0.4, 0.75, and 1.5 micrograms/min (each for 15 min). Saline control infusion was given in the same manner in a crossover and blinded protocol. Compared with the infusion of placebo, stepwise increasing doses of isoprenaline caused a dose-related increase in early and late diastolic filling velocities and velocity-time integrals, a lengthening of the acceleration time, and a shortening of t…
Relative sensitivity of four noninvasive methods in assessing systolic cardiovascular effects of isoproterenol in healthy volunteers.
1992
Study objective The study was performed to evaluate the relative sensitivity of various noninvasive methods to detect and describe the systolic cardiovascular effects of stepwise increasing doses of isoproterenol: two-dimensional left ventricular echocardiography (main variable, ejection fraction), ACVF (attenuation compensated volume flow)–dual-beam Doppler echoaortography (time-averaged mean velocity), electrical impedance cardiography [(dZ/dtmax)/RZ index], and systolic time intervals from mechanocar-diography (PEP and QS2c). Methods Isoproterenol was administered by constant rate intravenous infusion in consecutive steps of 0.1, 0.2, 0.4, 0.75, and 1.5 µg/min (each for 15 minutes). Sali…
Safety Profile of Methylphenidate Under Long-Term Treatment in Adult ADHD Patients – Results of the COMPAS Study
2020
Abstract Introduction The Comparison of Methylphenidate and Psychotherapy in adult ADHD Study (COMPAS) was a prospective, randomized multicenter clinical trial, comparing methylphenidate (MPH) with placebo (PLAC) in combination with cognitive behavioral group psychotherapy (GPT) or individual clinical management (CM) over the period of 1 year. Here, we report results on treatment safety. Methods MPH and PLAC were flexibly dosed. Among 433 randomized patients, adverse events (AEs) were documented and analyzed on an “as received” basis during week 0–52. Electrocardiogram data were recorded at baseline and week 24. Results Comparing 205 patients who received ≥1 dose of MPH with 209 patients wh…
Effects of antiepileptic drugs on cortical excitability in humans: A TMS-EMG and TMS-EEG study.
2018
Brain responses to transcranial magnetic stimulation (TMS) recorded by electroencephalography (EEG) are emergent noninvasive markers of neuronal excitability and effective connectivity in humans. However, the underlying physiology of these TMS-evoked EEG potentials (TEPs) is still heavily underexplored, impeding a broad application of TEPs to study pathology in neuropsychiatric disorders. Here we tested the effects of a single oral dose of three antiepileptic drugs with specific modes of action (carbamazepine, a voltage-gated sodium channel (VGSC) blocker; brivaracetam, a ligand to the presynaptic vesicle protein VSA2; tiagabine, a gamma-aminobutyric acid (GABA) reuptake inhibitor) on TEP a…
Loss of the preconditioning effect of rosuvastatin during sustained therapy: a human in vivo study
2011
Studies have demonstrated that the acute administration of 3-hydroxy-3 methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors has protective effects in the setting of ischemia-reperfusion (IR). Previously, we demonstrated that a single dose of rosuvastatin prevented IR-induced endothelial dysfunction in humans through a cyclooxygenase-2-dependent mechanism. Whether the chronic administration of HMG-CoA reductase inhibitors provides similar protection remains controversial and is unknown in humans. Eighteen male volunteers were randomized to receive a single dose of rosuvastatin (20 mg) or placebo. Twenty-four hours later, endothelium-dependent, radial artery flow-mediated dilation (FMD) w…
Comparison of short-term light disturbance, optical and visual performance outcomes between a myopia control contact lens and a single-vision contact…
2020
Purpose To compare the optical and visual performance of a dual-focus (DF) contact lens used for myopia control with a single-vision (SV) contact lens of the same material. Methods A randomised, double-masked crossover study. Twenty-eight healthy, myopic volunteers between 18 and 32 years of age (23.49 +/- 4.07 years) participated in this study. The sensory dominant eye for distance vision was determined. Refraction, best-corrected visual acuity (VA) and aberrations for 3 mm and 5 mm pupil diameters were quantified without a contact lens in situ. Subjects were fitted with two contact lens designs: DF and SV, both made of omafilcon A material. The Quality of Vision (QoV) questionnaire, over-…