Novel organic semiconductors based on 2-amino-anthracene: Synthesis, charge transport and photo-conductive properties.

Anthracene is considered to be a popular choice as a building block for organic semiconductors. The present work is dedicated to the synthesis and characterization of a novel semiconductor (10-OPIA) possessing mesogenic properties, which allows better control over charge transport in the bulk of a material. A novel anthracene-based molecule is characterized for its potential applications: frontier molecular energy levels are studied by optical spectroscopy and cyclic voltammetry and compared to values obtained via ab initio calculations. Thermophysical and mesogenic properties are investigated by optical microscopy and differential scanning calorimetry. Charge transport properties are characterized by means of an OFET device. It is found that this material can be easily aligned and exhibits a field effect hole mobility of 5.22 × 10-5 cm2 V-1 s-1 and an ON/OFF ratio of 104 in the device prepared by drop casting. Finally, the photoconductive properties of this novel material are addressed in order to investigate its potential applications for organic phototransistors: it exhibits a large photoconductive gain of >100 and a photo-responsivity of >1 A W-1.

Electrophysiological assessment methodology of sensory processing dysfunction in schizophrenia and dementia of the Alzheimer type.

Schizophrenia and Alzheimer's disease impacts on various sensory processings are extensively reviewed in the present publication. This article describes aspects of a research project whose aim is to delineate the neurobiology that may underlie Social Withdrawal in Alzheimer's disease, Schizophrenia and Major Depression. This is a European-funded IMI 2 project, identified as PRISM (Psychiatric Ratings using Intermediate Stratified Markers). This paper focuses specifically on the selected electrophysiological paradigms chosen based on a comprehensive review of all relevant literature and practical constraints. The choice of the electrophysiological biomarkers were fundamentality based their metrics and capacity to discriminate between populations. The selected electrophysiological paradigms are resting state EEG, auditory mismatch negativity, auditory and visual based oddball paradigms, facial emotion processing ERP's and auditory steady-state response. The primary objective is to study the effect of social withdrawal on various biomarkers and endophenotypes found altered in the target populations. This has never been studied in relationship to social withdrawal, an important component of CNS diseases.

Cyclodextrin modified PLLA parietal reinforcement implant with prolonged antibacterial activity.

The use of textile meshes in hernia repair is widespread in visceral surgery. Though, mesh infection is a complication that may prolong the patient recovery period and consequently presents an impact on public health economy. Such concern can be avoided thanks to a local and extended antibiotic release on the operative site. In recent developments, poly-l-lactic acid (PLLA) has been used in complement of polyethyleneterephthalate (Dacron®) (PET) or polypropylene (PP) yarns in the manufacture of semi-resorbable parietal implants. The goal of the present study consisted in assigning drug reservoir properties and prolonged antibacterial effect to a 100% PLLA knit through its functionalization with a cyclodextrin polymer (polyCD) and activation with ciprofloxacin. The study focused i) on the control of degree of polyCD functionalization of the PLLA support and on its physical and biological characterization by Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC) and cell viability, ii) on the understanding of drug/meshes interaction using mathematic model and iii) on the correlation between drug release studies in phosphate buffer saline (PBS) and microbiological evaluation of meshes and release medium against E. coli and S. aureus. All above mentioned tests highlighted the contribution of polyCD on the improved performances of the resulting antibacterial implantable material. STATEMENT OF SIGNIFICANCE: 1. We managed for the first time, with well-defined parameters in terms of temperature and time of treatment, to functionalize a bio-absorbable synthetic material to improve drug sorption and drug release properties without affecting its mechanical properties. 2. We analyzed for the first time the degradation of our coating products by mass spectroscopy to show that only citrate and cyclodextrin residues (and glucose units) without any cytotoxicity are formed. 3. We managed to improve the mechanical properties of the PLA with the cyclodextrin polymer to form a composite. The assembly (cyclodextrin polymer and PLLA) remains biodegradable.

Immobilization of fluorescent chemosensor on pyrogenic silica: a promising device for gaseous detection.

A new approach to enhance performances of a cyclodextrin-based fluorescent chemosensor combining grafting on a silica matrix and quaternization reaction is presented. The full characterization of new fluorescent hybrid material has clearly revealed the embedding of cyclodextrin inside the siliceous material. Finally, through a comparison with previous aqueous studies, a preliminary test of toluene detection was presented and highlighted the high potential of this approach, which opens attractive perspectives of evolution toward more sensitive and selective VOC's sensing in air or in hot industrial gaseous waste.

Absolute bioavailability and electroencephalographic effects of conventional and extended-release formulations of venlafaxine in healthy subjects.

Venlafaxine is currently marketed for treatment of depressive disorders as a conventional tablet formulation with a twice or three times daily dosage regimen. The absolute bioavailability of the conventional (CF) and extended-release (XR) formulations and their effects on electroencephalograms (EEG) and on a visual analog scale (VAS) for nausea were assessed in a randomized, double-blind, four-way crossover, placebo-controlled study of 16 healthy young men who were given either a single oral dose of 50 mg of CF venlafaxine, 75 mg of XR venlafaxine, or an intravenous dose of 10 mg of venlafaxine, or a placebo at 1-week intervals. The absolute bioavailability of venlafaxine was between 40% and 45% and was similar for both the CF and XR formulations. Venlafaxine produced central effects of a desipramine-like antidepressant. Regardless of formulation tested, the main EEG changes were an increase in fast beta (20-30 Hz) energy, which was more pronounced over the frontotemporal regions and extended within the full beta range (16-40 Hz). Maximum effect was reached at 6 hours for the CF and reached a plateau from 10 to 24 hours for the XR formulation. A dose-proportional increase in central activity, expressed as area under the effect curve (AUE) of the beta band, was observed between the CF (50 mg) and XR (75 mg) formulations. Compared with the CF tablet, the XR formulation also produced a much less intense maximum effect and a decrease of 63% in the AUE of nausea normalized by dose. The XR formulation has the same absolute bioavailability and the same central activity as assessed by EEG, but produced less intensive nausea than CF venlafaxine. The present findings suggest that a once-daily dosage regimen should be sufficient. This was confirmed by several clinical trials in depressive patients.

Effects of the selective activation of 5-HT3 receptors on sleep: a polysomnographic study in healthy volunteers.

The respective role of various classes of central serotonin (5-HT) receptors in the regulation of sleep-wakefulness cycles has been the subject of many studies. Notably, it has been reported that 5-HT1A/B receptors are involved in the regulation of rapid eye movement sleep (REMS) and that 5-HT2A/C receptors participate in the control of slow wave sleep (SWS), but the role of 5-HT3 receptors is less well characterised. In this study we investigated the effects of SR 57227A, a potent and selective 5-HT3 agonist, on the sleep EEG of normal young male volunteers. SR 57227A (2.5, 5, 10, 20, 40 mg o.d. and 20 mg b.i.d.) or placebo were administered during 7 consecutive days in seven groups of ten subjects using a parallel group design. Sleep EEG recordings were performed on days 6 and 7 after an habituation session. SR 57227A produced a dose-dependent shift of REMS toward the end of the night without changing REMS and SWS duration nor altering sleep continuity. It suggests a role for the 5-HT3 receptor in the human sleep-wakefulness cycle and particularly in REMS regulation.

Sensitivity and specificity to amphetamine of a French version of the 49-item form of the addiction research center inventory.

The main metrological characteristics of a French version of the 49-item addiction research center inventory (ARCI) were evaluated using data collected in three controlled studies in healthy subjects. An analysis of variance showed no study effect, so the three studies were pooled. The test-retest reliability coefficients after placebo evaluated by a Spearman rank correlation test were 0.64 (P < 0.0001) for subscale A, 0.49 (P < 0.0001) for subscale BG, 0.55 (P < 0.0001) for MBG, 0.58 (P < 0.0001) for PCAG and 0.27 for LSD (not significant). Using the same test, the test-retest reliability coefficients after amphetamine were 0.73 (P < 0.0001) for subscale A, 0.61 (P < 0.0001) for subscale BG, 0.71 (P < 0.0001) for MBG, 0.46 (P < 0.0001) for PCAG and 0.66 for LSD (P < 0.0001). In order to assess the predictive validity of the translated questionnaire, areas under curves were calculated from the ROC diagrams for the three scores, amphetamine (A), benzedrine group (BG) and morphine benzedrine group (MBG). Two criteria validity were used: the desire to take amphetamine another time and the discrimination of the allocated treatment (amphetamine or placebo). The calculated areas under curves indicated a good capacity of prediction of the three ARCI subscales (A, BG, MBG) for both criteria.

Beta-adrenoceptor agonists do not stimulate daytime melatonin secretion in healthy subjects. A double blind placebo controlled study.

Noradrenergic stimulation of pineal beta-adrenoceptors results in melatonin secretion. To investigate beta-adrenoceptor mediated plasma melatonin responses in humans, ritodrine, salbutamol (beta 2-adrenoceptor agonists) and dobutamine (beta 1-adrenoceptor agonist) were infused from 0900 to 1200 h to 8 healthy subjects (four men and four women) in a double blind, crossover, placebo controlled study. Ritodrine and salbutamol significantly increased plasma cyclic AMP and decreased serum potassium concentrations indicating the presence of beta 2-adrenoceptor stimulation. Dobutamine substantially increased systolic blood pressure corresponding to its beta 1-adrenoceptor agonist propriety. However, neither beta 2- nor beta 1-adrenoceptor stimulation modified plasma melatonin concentration. These results show that beta-adrenoceptor agonists do not increase daytime plasma melatonin concentration.

Comparative effects of zopiclone, triazolam and placebo on memory and psychomotor performance in healthy volunteers.

This study evaluated the effects of acute doses of zopiclone (7.5 mg), triazolam (0.25 mg) and placebo on memory and psychomotor performance of 12 normal volunteers. The subjects received both drugs in a repeated measure, double-blind Latin square design. The tests (CFF, CRT, DSST, memory assessments) were performed before and 2 and 6 hr after treatment. Zopiclone and triazolam induced an anterograde amnesia affecting short-term and long-term memory which lasted less than 6 hr. No retrograde amnesia was observed. Two hr after drug intake of both hypnotics psychomotor performances were significantly altered compared with placebo. The subjects also felt more drowsy, dizzy, clumsy and tired, and less alert and energetic 2 hr after zopiclone and triazolam compared to placebo. There was no difference between the effects of the two hypnotics at the doses studied.

Pharmacokinetics and pharmacodynamics of zolpidem following repeated doses in hemodialyzed uraemic patients.

Zolpidem, an imidazopyridine derivative, is a chemically novel, non-benzodiazepine hypnotic agent. Many uraemic patients complain of sleep disorders and ask for hypnotic medication which is well tolerated both clinically and biologically in such patients. We studied the pharmacokinetics and pharmacodynamics of zolpidem in 12 end-stage renal patients regularly treated by hemodialysis three times a week. Zolpidem (10 mg) was given orally for 14 or 21 days. Pharmacokinetic and pharmacodynamic evaluations were repeated at the end of the study on day 14 or day 21. Cmax, Tmax, t1/2 and the area under the curve were not modified in hemodialyzed patients. After daytime dosing, zolpidem induced the same level of sleepiness after the first and last dose and was well tolerated as a hypnotic agent after the night-time dosing. From these results, it can be said that zolpidem may be administered safely to patients with severe renal impairment without any modification of the dosage regimen.

Assessment of the interaction between a partial agonist and a full agonist of benzodiazepine receptors, based on psychomotor performance and memory, in healthy volunteers.

Potential interactions between the imidazopyridine anxiolytic alpidem and the full benzodiazepine agonist lorazepam were assessed in a randomized, double-blind, four-way cross-over, placebo-controlled study in 16 healthy young male volunteers. Each volunteer received alpidem, 50 mg, or a placebo twice daily for 8 days with a 1- week wash-out interval. The interaction between alpidem, at the steady state, and a single oral dose of lorazepam 2 mg or a placebo was assessed after concomitant administration on days 7 or 9 of each treatment period. Psycho motor performance and cognitive function were evaluated before and 2, 4, 6 and 8 h post-dose, using objective tests [critical flicker fusion threshold (CFF), choice reaction time (CRT), digit-symbol substitution (DSST), body sway and short-term memory (Sternberg memory scanning)] and self-ratings [line analogue rating scales: (LARS)]. Long-term memory (delayed free recall and recognition of pictures) was assessed before the dose and 2 and 4 h post-dose. Pharmacodynamic interactions were evaluated by applying repeated measures ANOVA to a 2 x 2 factorial interaction model. Alpidem, 50 mg twice daily at the steady state, was free of any clinically relevant detrimental effects on skilled performance, information processing or memory. In contrast, a single 2 mg dose of lorazepam induced marked impairment of psychomotor performance and cognitive function (significant reductions in CFF and DSST and increases in CRT and body sway), as well as subjective sedation from 2 to 8 h post-dose, depending on the test used. In addition, lorazepam induced anterograde amnesia, characterized by a decrease in delayed free recall and recognition, and a deficit in short-term memory. Finally, alpidem 50 mg did not potentiate the detrimental effects of lorazepam 2 mg. On the contrary, alpidem significantly antagonized the lorazepam-induced CRT increase and anterograde amnesia, and produced similar trends on most of the other cognitive parameters; thus, the results obtained with the combination of alpidem and lorazepam consistently indicated less impairment than those measured after lorazepam alone. These results are consistent with the suggested partial agonsist properties of alpidem at the benzodiazepine receptor and indicate that such properties can be assessed in humans based on antagonism of the effects of a full agonist.

Safety and tolerance profile of venlafaxine.

Venlafaxine has been shown in clinical trials to be safe and well tolerated in patients with major depression. Data were pooled from 19 studies in which 2181 patients were given venlafaxine, 451 were given placebo and 591 were given a reference antidepressant (imipramine, trazodone, clomipramine, maprotiline, dothiepin or amineptine). Long-term safety was evaluated in 422 patients who were given venlafaxine for at least 1 year; as well, a total of 229 elderly patients have been treated with venlafaxine, including 66 who were given it for at least 1 year. The adverse events that occurred during short-term treatment in > or = 10% of patients were nausea, headache, insomnia, somnolence, dry mouth, dizziness, constipation, asthenia, sweating and nervousness. In comparator-controlled trials, the frequency of anticholinergic events with the reference agents was approximately twice that with venlafaxine. The safety profile and patient acceptability of venlafaxine are comparable to those of third-generation antidepressants, and possibly better than those of first-generation agents.

Lack of sleep-inducing properties of propranolol (80 mg) in chronic insomniacs previously treated by common hypnotic medications.

In a double-blind, placebo-controlled crossover trial, propranolol 80 mg did not show any hypnotic properties and even increased the insomnia in a sample of 37 patients previously treated chronically with hypnotic medication (mostly benzodiazepines). This worsening of the insomnia is consistent with the observations of sleep disturbance at the beginning of treatment with beta-blocking drugs. This lack of efficacy suggests that the anti-stress or anxiolytic properties of propranolol do not apply to the rebound insomnia seen when stopping treatment with hypnotic drugs.

Effects of dihydroergotamine on psychomotor function, neuroendocrine parameters and blood pressure, in healthy volunteers.

Following the infusion of 15 micrograms/kg of dihydroergotamine (DHE) a 50-fold rise in growth hormone plasma levels was observed in 9 healthy volunteers. Prolactin (PRL) secretion was depressed 240 minutes post infusion. For 170 min, diastolic blood pressure was increased reaching a peak of +19 mmHg at the end of the infusion. Mild sedation and nausea were induced by the treatment for a total duration of 60 min.

Comparative study of the psychomotor and antistress effects of ritanserin, alprazolam and diazepam in healthy subjects: some trait anxiety-independent responses.

The new potential anxiolytic ritanserin was studied in a double-blind manner vs. alprazolam, diazepam and placebo in 23 healthy subjects. The subjects belonged either to a high anxiety level group or a low anxiety level group, in order to study the effect of the anxiety level on the pharmacodynamic responses. The assessments included cognitive function (memory tests), psychomotor performance [Critical Flicker Fusion (CFF), Choice Reaction Time (CRT)], subjective ratings of alertness and overnight sleep and stress paradigm. Ritanserin (10 mg), alprazolam (0.75 mg), diazepam (10 mg) and placebo were given as single oral doses following a latin square design. Groups were well contrasted on the Cattell anxiety scale and were not overlapping. On no psychometric variable have there been any interactions between the anxiety level and the drug factor. At baseline an anxiety-related difference between the two groups was observed: lower CFF value in the high anxiety group (-1.4 Hz). Both benzodiazepines impaired psychomotor assessment and memory function and increased sleepiness. Ritanserin decreased CFF values without significantly affecting CRT on which nevertheless a trend to impairment was observed. Memory tests, and subjective ratings of alertness were unaffected by ritanserin. A trend to an antistress effect was observed on electrodermogram after ritanserin. Both benzodiazepines decreased central nervous system arousal and memory while ritanserin was inactive except on CFF. Recent data support the hypothesis that 5-HT2 blockers decrease pupil diameter which is a well known covariate of flicker frequency.

Lack of amnestic, psychotomimetic or impairing effect on psychomotor performance of eliprodil, a new NMDA antagonist.

The possible effects on memory, psychomotor performance and mood of eliprodil, a new non-competitive NMDA receptor antagonist acting through the polyamine modulatory site, was assessed in a randomized, double-blind, cross-over, placebo-controlled study involving 11 healthy young male volunteers. Eliprodil 30 mg, a placebo and midazolam 15 mg, a positive control, were administered as a single oral dose at 1 week wash-out intervals. Objective tests evaluated both memory (Sternberg memory scanning and paired words for short-term memory, delayed free recall of pictures for long-term memory) and psychomotor functions and arousal (critical flicker fusion threshold, choice reaction time, body sway). Mood was assessed using self-ratings (LARS, POMS, ARCI). Statistical analysis was performed using an ANOVA with pairwise comparisons using Tukey's method. A single dose of eliprodil 30 mg was free of any detrimental effect on memory and skilled performance and did not produce either subjective sedation or excitation or psychotomimetic effects in comparison with placebo. In contrast, a single dose of midazolam 15 mg induced a marked impairment in psychomotor performance and cognitive functions (significant reduction in CFF, increase in CRT and body sway, disruption of short- and long-term memory). The potent sedative activity of midazolam, peaking 1 to 3 h post-dose, was confirmed by subjective evaluation and had disappeared 8 h post-dose.

[Effects of 3 doses of maprotiline (25, 50 and 75 mg) on alertness and memory in healthy volunteers]. / Effets de trois doses de maprotiline (25, 50 et 75 mg) sur la vigilance et la mémoire chez le volontaire sain.

The effects on psychomotor and mnesic performance of acute oral doses of maprotiline (25, 50 and 75 mg) were evaluated in twelve healthy men in a placebo-controlled double blind study. A battery of tests was performed comprising: objective measures (critical flicker frequency, choice reaction time, memory tasks) and self rating evaluation (visual analogue scales). Tests session took place 15 hours after each treatment. Plasma concentrations of maprotiline were determined. Compared with placebo, maprotiline induced psychomotor impairment on both objective and subjective assessment in a dose related manner. No significant difference between maprotiline and placebo on memory test could be evidenced.

[Personality of healthy volunteers. Normality and paradox]. / La personnalité du volontaire sain. Normalité et paradoxe.

The personality characteristics of 62 subjects to be screened for eligibility in psychopharmacology studies have been assessed. The psychological screening comprised the Cattell anxiety scale (CAS), the Eysenck Personality inventory (EPI) and the Minnesota Multiphasic Personality Inventory (MMPI) in its complete version (550 items). The comparison of the results to a population matched for age and status showed that the anxiety level was not different, extraversion factor was higher (p less than 0.001) and various personality traits were different. The most striking differences were observed on the factors: Psychopathic deviation, Mania, Schizophrenia greater than controls and social introversion lower than controls. These differences may evoke several biases, such as a recruitment bias or a specific personality pattern of young healthy subjects. In order to discuss these hypothesis, further comparisons with other centers are required to conclude.

Cognitive impairments induced by triazolam in healthy volunteers: antagonism by a partial inverse agonist of benzodiazepine receptor.

Pharmacological studies revealed that SR 25776 possesses marked stimulant activity characteristic of a partial inverse agonist of benzodiazepine receptor. The effects of SR 25776 500 mg alone and in combination with triazolam 0.25 mg on psychomotor performance and memory were assessed in 8 healthy consenting male volunteers in a double-blind placebo controlled trial. Treatment effects were monitored before and two and half hours following oral medication. The present study suggest that at the studied dose SR 25776 may incompletely antagonize the sedative and amnesic effects of a benzodiazepine agonist without producing marked effects of its own.

Single dose of prednisone does not induce amphetamine-like subjective effects in healthy subjects.

Among the methods developed in assessing abuse liability, the behavioural and subjective effects of drugs can be recorded using the Addiction Research Center Inventory (ARCI) in drug-experienced subjects and normal volunteers. Sixteen healthy volunteers with no history of drug abuse participated in the study. The subjective, behavioural and physiological effects of prednisone (30 and 60 mg) were compared with those of dextroamphetamine (15 mg) and placebo in a randomized double-blind Latin square design. The self-questionnaires (ARCI, Profile of Mood States, Visual Analogue Scales and Sleep Questionnaire) were completed before, 1, 2, 4 and 8 h post single oral dosing. Results showed that subjective effects of the two studied doses of prednisone did not resemble those induced by dextroamphetamine (15 mg). These results indicate that oral single doses of prednisone do not possess amphetamine-like subjective effects in a healthy population. The well established psychostimulant effect of amphetamine have been replicated on almost all subjective assessments.