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Biomedical subjects

O Blin

Publications and source records attributed to O Blin.

At least 37 records · Page 2Linked to original sources
PubMed2001

Age and risk-taking in French naval crew.

The purpose of this study was to evaluate the effects of age in French naval crew on risk-proneness. We tested 130 male navy personnel, age range 19-41 yr, with EVAR, a visual analog scale designed to rate risk-proneness and composed of 24 items distributed among 5 factors: "self control," "danger-seeking" "energy," "impulsiveness," and "invincibility." We observed a significant negative correlation between "energy" and age, whereas the other factors were not influenced by age. Risk-proneness change is limited and should not be a safety issue in the decision-making process if the age of navy crews is going to increase moderately.

Adult↗
PubMed2001

Antipsychotic-associated weight gain and clinical outcome parameters.

Weight gain has been observed with many of the antipsychotics, including the atypical antipsychotics. The assessment of whether, and to what degree, a drug causes changes in body weight is not straightforward, since clinical studies performed during a drug development program are not designed to measure changes in body weight. Even when weight change data are obtained from adverse event data or from part of the vital signs measured during a study, assessment is not standardized. Nevertheless, evidence points to the fact that weight gain with the atypical antipsychotics is becoming an increasing problem. This review examines whether antipsychotic-associated weight gain, when it occurs, is associated with clinical outcome parameters.

Ambulatory Care↗
PubMed2001

Risk propensity assessment in military special operations.

Risk taking, decision making, and stress factors are strongly associated in military operations. The authors used the Bond and Lader mood and alertness scale and a new scale, Evaluation of Risks (EVAR), to assess risk proneness in a maritime counter-terrorism exercise. EVAR items are distributed among five factors: self-control, danger seeking, energy, impulsiveness, and invincibility. In the study, 10 pilots were submitted to strenuous night flights with limited sleep deprivation. Compared with baseline data, pilots reported an increase in impulsiveness, whereas EVAR factors were consistent in a control group composed of 9 navy crew member. Correlations were observed between mood and alertness and risk factors. These results illustrate how EVAR can be used to evaluate change in risk proneness in individuals submitted to various stressors. But further studies are required to weigh stress factors and environmental conditions in risk propensity with a larger population of various age and personality traits.

Adult↗
PubMed2000

Lorazepam-induced modifications of saccadic and smooth-pursuit eye movements in humans: attentional and motor factors.

In a placebo-controlled, double-blind study, we measured the effects of low dose lorazepam on attentional and motor factors involved in saccadic and smooth pursuit eye movements. We manipulated the temporal interval between the extinction of the central fixation target and the appearance of a second eccentric target (gap/overlap step paradigm). The second target was either stationary (saccade trial) or moving in a direction opposite to the step (pursuit trial). Gap/overlap effects on the latency of saccadic and smooth pursuit eye movements were measured before and after oral intake of either lorazepam or placebo. Pharmacological effects on the dynamics and the accuracy of both types of eye movements were also investigated. In 14 healthy volunteers, we found that the temporal interval between fixation target offset and eccentric target onset modulates the latency of saccadic and smooth pursuit eye movements in a similar way. As compared to placebo, lorazepam significantly increased the latency of both types of eye movements, but did not modify the gap/overlap effect. Moreover, lorazepam significantly decreased the peak velocity of the first saccade towards the eccentric stationary target, as well as the gain of tracking towards the eccentric moving target. However, the overall accuracy of both behaviors was not significantly affected, indicating that systematic errors in foveating or tracking were detected and corrected by appropriate corrective or catch-up saccades, respectively. Results are discussed in terms of shared/different mechanisms for saccadic and pursuit systems in primates.

Adult↗
PubMed2000

Pronounced effect of caprylocaproyl macrogolglycerides on nasal absorption of IS-159, a peptide serotonin 1B/1D-receptor agonist.

OBJECTIVES: This double-blind, randomized, two-way crossover study in 12 healthy male subjects investigated the influence of caprylocaproyl macrogolglycerides on the pharmacokinetics of IS-159 (serotonin-carboxylmethyleneoxy-L-tyrosylglycinamide), a peptide serotonin 1B/1D-receptor agonist, after intranasal administration. METHODS: A dose of 4 mg IS-159 was administered in a volume of 200 microL, once in the presence and once in the absence of 2% caprylocaproyl macrogolglycerides. Plasma concentrations of IS-159 were measured over a period of 12 hours for determination of pharmacokinetic parameters. Systemic and local tolerability were assessed at regular time points, the latter by rhinoscopy and visual analog scales. RESULTS: Caprylocaproyl macrogolglycerides significantly increased the maximum plasma concentration (from 4.7 +/- 1.7 to 48 +/- 17 ng/mL) and the area under the plasma concentration-time curve (from 12 +/- 4.7 to 56 +/- 22 ng x h/mL) of IS-159. The time to maximum concentration (15 to 20 minutes) and the elimination half-life (2.0 to 2.3 hours) were not different between the two treatments. Rhinoscopic examination revealed no differences between treatments, but in the presence of caprylocaproyl macrogolglycerides subjects reported more local and systemic adverse events and on the visual analog scales greater nasal obstruction and rhinorrhea. CONCLUSION: 2% caprylocaproyl macrogolglyceride markedly increased the absorption of IS-159 through the nasal mucosa and elicited only mild irritant effects.

Administration, Inhalation↗
PubMed2000

Effects of lorazepam on emotional reactivity, performance, and vigilance in subjects with high or low anxiety.

This study examined the hypothesis that low doses of lorazepam modify emotional response. In accord with the results of prior studies that suggest a differential effect of benzodiazepines according to the subjects' anxiety level, the authors tested the effect of lorazepam (0.5 mg twice daily) on 2 groups of 32 subjects: those with high anxiety (HA) and those with low anxiety (LA). These groups were formed a priori on the basis of their scores on the Cattell Anxiety Scale and the Hamilton Rating Scale for Anxiety. The two groups were evaluated for psychomotor function and vigilance (visual analog scales [VAS], digit-symbol substitution test [DSST], and choice reaction time [CRT]), as well as emotional reactivity. Six emotions (fear, anger, disgust, sadness, joy, and neutral state) were induced by the presentation of six movie excerpts, and subjects' emotional responses were measured using the Differential Emotions Scale. The results suggest that at the doses studied, lorazepam led to an increase in negative emotions and a decrease in positive emotions, compared with placebo. This shift of emotional reactivity toward more negative emotions was slightly stronger with the HA than with the LA subjects. However, no reliable differences in the levels of performance and vigilance (CRT, DSST, and VAS) were observed as a function of either treatment or subject group. These findings suggest a possible relationship between benzodiazepine effects and subjects' anxiety level.

Adult↗
PubMed2000

Which role for amisulpride in rehabilitation of schizophrenic patients with acute exacerbation?

Amisulpride is a substituted benzamide derivative with selective binding to the D2/D3 dopamine receptor. In patients, a beneficial effect on negative signs has been demonstrated for doses up to 300 mg daily. On the other hand, amisulpride demonstrate efficacy in the treatment of classical form of schizophrenia at higher doses (400 to 800 mg/day up to 1,200 mg/day at the maximum). Five studies that included acutely ill schizophrenic patients are reviewed. All were double blind, randomized parallel group studies and the primary efficacy criterion was the BPRS total score. In these study amisulpride was at least as efficacious as haloperidol (10-30 mg), risperidone (8 mg daily), or flupentixol (25 mg daily) in controlling positive symptoms, but was significantly more effective than haloperidol on secondary negative symptoms. When quality of life (QLS) was assessed, amisulpride led to a better improvement than haloperidol. In the long term treatment of schizophrenia, amisulpride maintained antipsychotic efficacy over a 12-month period in an open randomized study. In this study, amisulpride led to a better improvement on Global Assessment of Functioning than haloperidol, the standard reference drug. Furthermore, amisulpride has a favorable benefit/risk profile and induces fewer extrapyramidal side effects than haloperidol the standard reference drug. Therefore, amisulpride is proposed for first-line treatment of schizophrenia in acute exacerbations. It contributes to favor a better social rehabilitation of schizophrenic patients.

Acute Disease↗
PubMed1999

Serotonin and human information processing: an electromyographic study of the effects of fluvoxamine on choice reaction time.

Previous studies have shown that fluvoxamine, an inhibitor of serotonin reuptake, shortens choice reaction time. The present study, was intended to explore this effect by using two complementary approaches: (i) Sternberg's additive factor method, and (ii) the analysis of the electromyographic activity of a prime mover. Eight healthy subjects who received either a single oral dose of fluvoxamine (100 mg) or a placebo participated in a choice reaction time experiment in which imperative signal intensity, stimulus-response mapping, and response repertoire were manipulated. Previous results were replicated. Moreover, it was shown that fluvoxamine shortens the interval between prime mover activation and overt response. This supports the hypothesis proposed in a previous study that fluvoxamine affects motor processes. A possible mechanism of this effect is discussed.

Adult↗
PubMed1999

ABT-431, a D1 receptor agonist prodrug, has efficacy in Parkinson's disease.

Studies in animal models show a selective D1 receptor agonist with full functional efficacy compared with dopamine to have antiparkinsonian efficacy of similar magnitude to levodopa, without the same propensity for inducing dyskinesia. To date, no such agent has been tested in humans. ABT-431 is the prodrug of A-86929, a full, selective D1 receptor agonist. Subjects (n = 14) with levodopa-responsive Parkinson's disease received five doses of ABT-431 (5, 10, 20, 30, and 40 mg) and one of placebo after a 12-hour levodopa holiday. Response was assessed by using the Unified Parkinson's Disease Rating Scale motor subsection. Dyskinesia was separately graded. ABT-431 showed efficacy significantly superior to placebo at doses of 10 mg and more, and of similar magnitude to that seen with levodopa. Dyskinesia was reduced in several patients after receiving ABT-431. There were no serious adverse events, the most common minor events being nausea and emesis, dizziness, and hypotension. Assuming that ABT-431 is not transformed in humans into an unknown active D2 metabolite, and remains selective for D1 receptors, it is the first dopamine D1 receptor agonist to demonstrate a full antiparkinsonian effect in patients with Parkinson's disease. These preliminary findings also suggest that it may exhibit a reduced tendency to provoke dyskinesia. The emergence of a well-tolerated D1 agonist should allow for the development of a better understanding of the relation between motor efficacy and dyskinesia in Parkinson's disease.

Aged↗
PubMed1999

Multicenter results of TADpole heart wire system used to treat postoperative atrial fibrillation.

OBJECTIVE: Postoperative atrial fibrillation (AF) affects 20-30% of patients undergoing open-heart surgery, delays mobilization and impairs hemodynamics. Implantation of TADpole Heart Wires offers a new method of applying internal low-energy-shocks to terminate AF. The safety and efficacy of the TADpole system to treat postoperative AF was evaluated in this multicenter trial. METHODS: Two atrial wires, configured with a highly flexible 11.5 cm distal shocking and a 0.5 cm proximal pacing electrode were sutured onto the right and left atrium. Upon detection of AF, R-wave synchronized low-energy-shocks were administered via an energy attenuating External Defibrillator Interface Module or ICD programmer. RESULTS: A total of 296 patients (65+/-9.2 years, 74.7% male) have been enrolled to date in six European centers. The wire placement time was 4.2+/-2.2 min, 65 patients had a total of 83 episodes of AF treated by the TADpole Heart Wire system with a conversion rate of 88.5% (approximate energy of 6+/-2 J), early recurrence of AF was observed in ten patients (12.8%). No clinical complications were reported. The shocks were well tolerated with slight sedation. The ease of withdrawal was 2.3+/-1.2 on a graded scale of 0 (easy) to 10 (difficult). CONCLUSIONS: These multicenter results indicate that postoperative atrial cardioversion using TADpole Heart Wires is both safe and efficient. It is expected that hospital length of stay and its associated economic impact can be reduced with this therapy.

Aged↗
PubMed1999

Pharmacokinetic-pharmacodynamic analysis of mnesic effects of lorazepam in healthy volunteers.

AIMS: To describe the pharmacokinetic-pharmacodynamic modelling of the psychomotor and mnesic effects of a single 2 mg oral dose of lorazepam in healthy volunteers. METHODS: This was a randomized double-blind, placebo-controlled two-way cross-over study. The effect of lorazepam was examined with the following tasks: choice reaction time, immediate and delayed cued recall of paired words and immediate and delayed free recall and recognition of pictures. RESULTS: The mean calculated EC50 values derived from the PK/PD modelling of the different tests ranged from 12.2 to 15.3 ng ml-1. On the basis of the statistical comparison of the EC50 values, the delayed recall trials seemed to be more impaired than the immediate recall trials; similar observations were made concerning the recognition vs recall tasks. CONCLUSIONS: The parameter values derived from PK/PD modelling, and especially the EC50 values, may provide sensitive indices that can be used, rather than the raw data derived from pharmacodynamic measurements, to compare CNS effects of benzodiazepines.

Amnesia, Anterograde↗
PubMed1999

Visual control of locomotion in Parkinson's disease.

The effect of placing parallel lines on the walking surface on parkinsonian gait was evaluated. To identify the kind of visual cues (static or dynamic) required for the control of locomotion, we tested two visual conditions: normal lighting and stroboscopic illumination (three flashes/s), the latter acting to suppress dynamic visual cues completely. Sixteen subjects with idiopathic Parkinson's disease (nine males, seven females; mean age 68.8 years) and the same number of age-matched controls (seven males; nine females, mean age 67.5 years) were studied. During the baseline phase, Parkinson's disease patients walked with a short-stepped, slow velocity pattern. The double limb support duration was increased and the step cadence was reduced relative to normal. Under normal lighting, visual cues from the lines on the walking surface induced a significant improvement in gait velocity and stride length in Parkinson's disease patients. With stroboscopic illumination and without lines, both groups reduced their stride length and velocity but the changes were significant only in the Parkinson's disease group, indicating greater dependence on dynamic visual information. When stroboscopic light was used with stripes on the floor, the improvement in gait due to the stripes was suppressed in parkinsonian patients. These results demonstrate that the perceived motion of stripes, induced by the patient's walking, is essential to improve the gait parameters and thus favour the hypothesis of a specific visual-motor pathway which is particularly responsive to rapidly moving targets. Previous studies have proposed a cerebellar circuit, allowing the visual stimuli to by-pass the damaged basal ganglia.

Aged↗
PubMed1999

A comparative review of new antipsychotics.

OBJECTIVE: To review the preclinical and clinical properties of various established and putative antipsychotic medications, namely clozapine, risperidone, amisulpride, olanzapine, quetiapine, sertindole, and ziprasidone. METHODS: This paper proposes a decision algorithm for comparing drugs used for psychotic disorders, based on biochemical profile, experimental pharmacology, postiron emission tomography (PET) scan results, and clinical efficacy on positive, negative, anxious, depressive, and cognitive symptoms. This "quotient" aims to compare the different available drugs, regardless of their development and registration status. RESULTS: Antipsychotic drugs have been classified in many ways, mainly according to their chemical structure, clinical effects, receptor affinity, or side effects. Preclinical data have indicated that these drugs might be effective antipsychotic agents, causing fewer extrapyramidal side effects than most of the previously marketed drugs. However, the biological basis for the putative superiority of these drugs in treating psychosis has yet to be ascertained. CONCLUSIONS: Although most antipsychotics have been shown to be at least equivalent to haloperidol on positive symptoms, they must be studied further to establish their absolute and relative efficacy on positive symptoms, negative and primary negative symptoms, cognition, psychotic anxiety, psychotic depression, suicidality, and quality of life. These drugs should be valuable in treating schizophrenia, but their merit in the long-term management of patients with schizophrenia still needs to be confirmed.

Antipsychotic Agents↗
PubMed1999

Time-dependent striatal dopamine depletion after injection of 6-hydroxydopamine in the rat. Comparison of single bilateral and double bilateral lesions.

For future investigation of possible perturbation of circadian rhythm in animal models of Parkinson's disease we needed an animal model providing lasting 80-100% striatal dopaminergic depletion in rats, but without induced mortality. We have thus compared the effects of a single hydroxydopamine bilateral striatal lesion (SB-hydroxydopamine) with those of a double hydroxydopamine bilateral lesion (DB-hydroxydopamine) at the same dose (16 microg/striatum) by HPLC determination of dopamine and 3,4-dihydrophenylacetic acid (dopac) levels in the striatum. Two weeks after neurosurgery, SB-hydroxydopamine and DB-hydroxydopamine induced dopaminergic depletion of at least 81% compared with control groups. After eight weeks striatal dopaminergic depletion was only 60.97% in SB-hydroxydopamine rats, suggesting a compensatory phenomenon, whereas in DB-hydroxydopamine rats dopaminergic loss was stable at 88%. For the DB-hydroxydopamine group the dopac/dopamine ratio was significantly increased at week 2 only, whereas no significant change was observed for other groups. This increase might be explained by increased dopamine turnover. We have demonstrated that striatal DB-hydroxydopamine injection induces lasting 80-100% neuronal loss, close to that observed in the disease in man, without induced mortality, and provides a tool which meets our experimental requirements.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1999

[Posture and gait modulation using sensory or attentional cues in Parkinson's disease. A possible approach to the mechanism of episodic freezing].

Parkinsonian patients have difficulties for walking as well as for adapting their posture following a voluntary or automatic movement that will disturb their equilibrium. Furthermore, in Parkinson's disease, the patients can suffer for motor blockades (or freezing) in which the movement is like frozen during its execution. These motor blockades can occur during gait initiation, turning round, as well as during the walking through apertures or small passages, but with a high variability as inter-individual as intra-individual. Cognitive, attentional or sensory stimulation--especially visual information--can interact directly on these motor blockades, either positively inhibiting them or negatively inducing them. The different modulation factors of locomotion as well as posture, in Parkinsonian patient and in healthy elderly, and the special case of the motor blockades in Parkinsonian patients are reviewed here. We also examine the effects of L-DOPA with respect to each of these factors. In the conclusion, the modulation of gait, posture, and freezing are discussed in term of mechanisms involved or hypothesis recently proposed.

Adaptation, Physiological↗
PubMed1998

Disease management: the example of amyotrophic lateral sclerosis.

Disease management is defined as any medical or pharmaceutical intervention designed to improve both outcomes for the patient and overall cost-effectiveness of the health plan. Disease management focuses on the patient throughout the entire course of the disease, involving both health providers and third-party payers. It requires structured management of change, inter- and intra-professional communication and access to information, identification of pertinent economic and clinical outcomes, and the establishment of guidelines, computerized systems and quality assurance. The concept of disease management remains controversial, primarily because its effectiveness is untested. Furthermore, if only economic outcomes are considered, ethical problems such as the selection of populations (for example, the exclusion from health care of people deemed 'too old') will emerge. As a model of neurodegenerative disease, amyotrophic lateral sclerosis (ALS) is a suitable condition for disease management. Many possible targets for disease management initiatives in ALS can be defined, including training, communication, education, guidelines for diagnosis, follow-up, clinical trials and treatments. Medico-economic studies need to be improved if accreditation is planned. Much remains to be done to improve the therapy and disease management of ALS. However, the identification of optimal treatment will improve care of ALS patients, particularly in less affluent countries.

Amyotrophic Lateral Sclerosis↗
PubMed1998

Fluoxetine in orthostatic hypotension of Parkinson's disease: a clinical and experimental pilot study.

Recent clinical studies have reported a beneficial effect of fluoxetine, a serotonin reuptake inhibitor, in patients with severe refractory orthostatic hypotension. The present study was undertaken to investigate the effect of fluoxetine in orthostatic hypotension occurring during Parkinson's disease on both blood pressure values and number of clinical symptoms during orthostatic procedure evaluated using a validated clinical rating scale. In a pilot study performed in fourteen patients with idiopathic Parkinson's disease plus orthostatic hypotension, fluoxetine hydrochloride (20 mg orally daily during one month) significantly reduced the fall in systolic blood pressure [-33 +/- 21 (SD) mmHg before fluoxetine vs -22 +/- 19 mmHg after fluoxetine, P = 0.03] elicited by standing without modifying heart rate. The drug also significantly reduced the number of postural symptoms occurring during the orthostatic procedure [2.9 +/- 1.5 (SD) before fluoxetine vs 1.2 +/- 1.3 after fluoxetine, P = 0.006]. A similar pattern of response was obtained in an experimental model of neurogenic orthostatic hypotension obtained in chronically sino-aortic denervated dogs submitted to an 80 degrees head-up tilt test procedure under chloralose anaesthesia. Fluoxetine did not change plasma noradrenaline levels. This pilot study suggests a slight but clinically significant effect of fluoxetine on both hemodynamic parameters and clinical symptoms in parkinsonian patients suffering from orthostatic hypotension.

Aged↗