Nicotine acts on nearly every physiological system of the human body. While the actions of nicoti... more Nicotine acts on nearly every physiological system of the human body. While the actions of nicotine on the autonomic nervous system may be of interest in understanding possible deleterious long-term effects of smoking on the cardiovascular system, the actions of nicotine on the central nervous system are of the most interest in understanding why people smoke. Many studies of the effects of nicotine on human cognitive function have been performed. Improvement in attention, learning, reaction time, and problem solving have been reported. However, most of the results are inconclusive owing to methodologic problems. Whether the enhanced performance observed after smoking is attributable to relief of symptoms of abstinence or to a primary effect of nicotine on the brain is not clear. The pharmacodynamic effects of nicotine must be considered in the design of studies of the effects of nicotine on human performance. It is not known if the effects of nicotine on performance are subject to tolerance. The facilitation of performance, perceived as a reinforcement, may tend to lessen throughout the day, as do other effects of nicotine. Studies of chronic tolerance to the behavioral effects of nicotine are needed; comparisons between regular smokers and occasional smokers may be helpful. At present, the facilitatory actions of nicotine on human performance have been explained in terms of arousal. However, nicotine actions cannot be explained in terms of this single concept. Different processes, including attention, stimulus evaluation, and response selection, appear to be involved in the effect of nicotine on human information processing. Finally, one must consider that the predominant effects of nicotine may differ among individuals, as different people smoke for different reasons, and the motives for (rewards of) smoking may vary in different situations.
Presse médicale (Paris, France : 1983), Jan 25, 1986
Tobacco dependence prevents any reduction in morbidity and mortality related to smoking. Nicotine... more Tobacco dependence prevents any reduction in morbidity and mortality related to smoking. Nicotine is widely regarded as responsible for this dependence process. It stimulates ubiquitous cholinergic receptors thus resulting mainly in catecholamine release. The causal role of nicotine in inducing and maintaining tobacco dependence is not so obvious as that of drugs responsible for other addictions. Animal models that have been described are not convincing. Smokers tend to change their smoking patterns so as to keep blood nicotine levels constant when nicotine yields of cigarettes are manipulated. This "nicotine titration phenomenon" is a strong argument in favor of them craving for nicotine. However, other components, such as tar, vary correlatively. Nicotine gum helps to quit smoking, but few people become gum-addicted. A better knowledge of the tobacco components that may induce dependence is needed to understand its neurochemical mechanisms and to provide the tobacco indu...
Progress in Neuro-Psychopharmacology and Biological Psychiatry, 1996
In order to inventory different Event-Related Potentials (ERP) modifications in HIV-infection the... more In order to inventory different Event-Related Potentials (ERP) modifications in HIV-infection the authors have evaluated 23 HIV-positive subjects and 12 HIV-negative subjects. ERP were recorded during an auditory oddball task. 2. Electrophysiological results showed that the latency of the NlOO component of the ERP was significantly increased in HIV-positive subjects compared to the HIV-negative subjects. The latency of the N200 component of the ERP showed a similar tendency which just failed to reach significance when considering HIV-positive subjects vs HIV negative subjects. This result was in agreement with the literature which reported increased latencies in HIV infection. 3. Considering all subjects the authors have observed a correlation between the amplitude of the P300 and the emotional deficit. This correlation was stronger in subjects who presented an emotional deficit and was independent of any other psychopathological symptom. 4. The use of ERP appeared to be a sensitive technique to detect subclinical manifestations in HIV asymptomatic subjects and therefore would help to identify subjects at higher risk for developing cognitive impairments.
The onset of action (during the first 2 weeks of treatment) of moclobemide (450 mg/day), a revers... more The onset of action (during the first 2 weeks of treatment) of moclobemide (450 mg/day), a reversible MAO-A inhibitor, was compared in a double-blind, multi-center trial with clomipramine (150 rag/day) on dimensional and global depressive symptoms in 124 hospitalized patients suffering from a major depressive episode according to DSM-III-R criteria and with blunted affect and retardation. An earlier efficacy was found for moclobemide with significant treatment differences in favor of moclobemide, which were detected on negative symptoms (anhedonia, blunted affect and retardation) on days 7 and 10. The overall effect on depression at the end of the 4-week trial period was similar in both groups. However, a higher termination rate due to lack of efficacy was found with moclobemide (10 vs. 3). The tolerability was significantly better for moclobemide, as shown by the lower frequency of adverse events.
La nicotine est responsable de la dependance au tabac, mais pas des maladies causees par les autr... more La nicotine est responsable de la dependance au tabac, mais pas des maladies causees par les autres constituants de la fumee (goudrons, CO, gaz oxydants...). La nicotine est particulierement addictive, lorsqu'elle est fumee, car elle atteint tres rapidement le cerveau. Elle se fixe sur les recepteurs cholinergiques nicotiniques et stimule les systemes de recompense en modulant la liberation de nombreux neurotransmetteurs. Les traitements nicotiniques de substitution (TNS) ne presentent pas ces memes dangers, car l'absorption de la nicotine est plus lente et ne provoque pas de pics cerebraux de concentration. Il est important que les medecins et les fumeurs comprennent bien cette distinction, car les TNS sont efficaces et presentent beaucoup moins de danger pour le fumeur, meme dans les populations a risque (grossesse, maladies pulmonaires et cardiovasculaires), et meme si certains fumeurs continuent de fumer en l'utilisant.
Les effets de la nicotine sur le systeme nerveux central sont importants pour la comprehension du... more Les effets de la nicotine sur le systeme nerveux central sont importants pour la comprehension du phenomene de dependance au tabac. Les etudes realisees au cours des annees 70 et 80 montrent un effet facilitateur sur les fonctions cognitives (attention, apprentissage, temps de reaction, resolution de problemes). Cependant, beaucoup d'erreurs methodologiques rendent ces experiences difficiles a interpreter. La publication d'un numero special de la revue Psychopharmacology en septembre 92 semble temoigner un regain d'interet pour ce domaine cognitif. Il reste cependant des questions a eclaircir. L'une est de savoir si l'effet de la nicotine sur le cerveau est direct ou indirect (du au comblement d'un syndrome de sevrage deteriorant les performances)
Réduction de consommation tabagique et abstinence temporaire : de nouvelles approches pour l'arrê... more Réduction de consommation tabagique et abstinence temporaire : de nouvelles approches pour l'arrêt du tabac.
Journal de Gynécologie Obstétrique et Biologie de la Reproduction, 2005
Question 3 Comment prendre en charge les femmes fumeuses ? Quelles sont les interventions efficac... more Question 3 Comment prendre en charge les femmes fumeuses ? Quelles sont les interventions efficaces d'aide à l'arrêt du tabac chez la femme enceinte ?
The primary reason why there is such a heavy burden of tobacco smoking induced illness and death ... more The primary reason why there is such a heavy burden of tobacco smoking induced illness and death is dependence on nicotine which makes it difficult for smokers to quit. For clinical or research purposes, the degree of dependence, the intensity of the withdrawal syndrome and/or craving have been evaluated by different scales. This review provides a list of questionnaires that are used in smoking cessation. It pays particular attention to the validated and translated resources that are available in French. Research should be conducted in order to provide French speaking smoking cessation specialists with all the relevant scales allowing better evaluation of tobacco dependence.
Journal de gynécologie, obstétrique et biologie de la reproduction, 2005
Tobacco smoking during pregnancy is the single largest modifiable risk for pregnancy-related morb... more Tobacco smoking during pregnancy is the single largest modifiable risk for pregnancy-related morbidity and mortality. Tobacco smoke contains thousands of chemicals, many of which may contribute to reproductive toxicity. Carbon monoxide is the most biologically significant toxin for the fetus. The use of nicotine replacement therapy is probably not without risk, although the magnitude of risk to the mother and fetus is much lower than continuing smoking. Most pregnant women are motivated to stop. It is, therefore, a good time to initiate smoking cessation as early as possible during pregnancy, and to maintain abstinence during post-partum to protect the infant from passive smoking. If behavioral intervention fail to produce abstinence, a sign of high dependence, nicotine replacement therapy should be initiated promptly. Although bupropion is not recommended during pregnancy, this therapy should be considered when contraindications are carefully observed. It is recommended that all pa...
The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease, 2003
Smoking is a complex behaviour involving both pharmacological and psychological components. Nicot... more Smoking is a complex behaviour involving both pharmacological and psychological components. Nicotine is the main alkaloid found in tobacco, and is responsible for its addictive potential. Nicotine-positive effects on mood and cognition are strong reinforcements for smokers that contribute to their addiction, and cigarette smoking is particularly addictive because inhaled nicotine is absorbed through the pulmonary venous rather than the systemic venous system, and thus reaches the brain in 10-20 seconds. As the likelihood that a substance will be abused depends on the time between administration and central reinforcement, tobacco smoking can easily become addictive. Nicotine replacement therapy (NRT) is available in different forms (gum, transdermal patch, nasal spray, inhaler, sublingual tablet and lozenge), and has been shown to relieve withdrawal symptoms and to double abstinence rates compared to placebo. Most NRT forms deliver nicotine more slowly than smoking, and the increase ...
Nicotine acts on nearly every physiological system of the human body. While the actions of nicoti... more Nicotine acts on nearly every physiological system of the human body. While the actions of nicotine on the autonomic nervous system may be of interest in understanding possible deleterious long-term effects of smoking on the cardiovascular system, the actions of nicotine on the central nervous system are of the most interest in understanding why people smoke. Many studies of the effects of nicotine on human cognitive function have been performed. Improvement in attention, learning, reaction time, and problem solving have been reported. However, most of the results are inconclusive owing to methodologic problems. Whether the enhanced performance observed after smoking is attributable to relief of symptoms of abstinence or to a primary effect of nicotine on the brain is not clear. The pharmacodynamic effects of nicotine must be considered in the design of studies of the effects of nicotine on human performance. It is not known if the effects of nicotine on performance are subject to tolerance. The facilitation of performance, perceived as a reinforcement, may tend to lessen throughout the day, as do other effects of nicotine. Studies of chronic tolerance to the behavioral effects of nicotine are needed; comparisons between regular smokers and occasional smokers may be helpful. At present, the facilitatory actions of nicotine on human performance have been explained in terms of arousal. However, nicotine actions cannot be explained in terms of this single concept. Different processes, including attention, stimulus evaluation, and response selection, appear to be involved in the effect of nicotine on human information processing. Finally, one must consider that the predominant effects of nicotine may differ among individuals, as different people smoke for different reasons, and the motives for (rewards of) smoking may vary in different situations.
Presse médicale (Paris, France : 1983), Jan 25, 1986
Tobacco dependence prevents any reduction in morbidity and mortality related to smoking. Nicotine... more Tobacco dependence prevents any reduction in morbidity and mortality related to smoking. Nicotine is widely regarded as responsible for this dependence process. It stimulates ubiquitous cholinergic receptors thus resulting mainly in catecholamine release. The causal role of nicotine in inducing and maintaining tobacco dependence is not so obvious as that of drugs responsible for other addictions. Animal models that have been described are not convincing. Smokers tend to change their smoking patterns so as to keep blood nicotine levels constant when nicotine yields of cigarettes are manipulated. This "nicotine titration phenomenon" is a strong argument in favor of them craving for nicotine. However, other components, such as tar, vary correlatively. Nicotine gum helps to quit smoking, but few people become gum-addicted. A better knowledge of the tobacco components that may induce dependence is needed to understand its neurochemical mechanisms and to provide the tobacco indu...
Progress in Neuro-Psychopharmacology and Biological Psychiatry, 1996
In order to inventory different Event-Related Potentials (ERP) modifications in HIV-infection the... more In order to inventory different Event-Related Potentials (ERP) modifications in HIV-infection the authors have evaluated 23 HIV-positive subjects and 12 HIV-negative subjects. ERP were recorded during an auditory oddball task. 2. Electrophysiological results showed that the latency of the NlOO component of the ERP was significantly increased in HIV-positive subjects compared to the HIV-negative subjects. The latency of the N200 component of the ERP showed a similar tendency which just failed to reach significance when considering HIV-positive subjects vs HIV negative subjects. This result was in agreement with the literature which reported increased latencies in HIV infection. 3. Considering all subjects the authors have observed a correlation between the amplitude of the P300 and the emotional deficit. This correlation was stronger in subjects who presented an emotional deficit and was independent of any other psychopathological symptom. 4. The use of ERP appeared to be a sensitive technique to detect subclinical manifestations in HIV asymptomatic subjects and therefore would help to identify subjects at higher risk for developing cognitive impairments.
The onset of action (during the first 2 weeks of treatment) of moclobemide (450 mg/day), a revers... more The onset of action (during the first 2 weeks of treatment) of moclobemide (450 mg/day), a reversible MAO-A inhibitor, was compared in a double-blind, multi-center trial with clomipramine (150 rag/day) on dimensional and global depressive symptoms in 124 hospitalized patients suffering from a major depressive episode according to DSM-III-R criteria and with blunted affect and retardation. An earlier efficacy was found for moclobemide with significant treatment differences in favor of moclobemide, which were detected on negative symptoms (anhedonia, blunted affect and retardation) on days 7 and 10. The overall effect on depression at the end of the 4-week trial period was similar in both groups. However, a higher termination rate due to lack of efficacy was found with moclobemide (10 vs. 3). The tolerability was significantly better for moclobemide, as shown by the lower frequency of adverse events.
La nicotine est responsable de la dependance au tabac, mais pas des maladies causees par les autr... more La nicotine est responsable de la dependance au tabac, mais pas des maladies causees par les autres constituants de la fumee (goudrons, CO, gaz oxydants...). La nicotine est particulierement addictive, lorsqu'elle est fumee, car elle atteint tres rapidement le cerveau. Elle se fixe sur les recepteurs cholinergiques nicotiniques et stimule les systemes de recompense en modulant la liberation de nombreux neurotransmetteurs. Les traitements nicotiniques de substitution (TNS) ne presentent pas ces memes dangers, car l'absorption de la nicotine est plus lente et ne provoque pas de pics cerebraux de concentration. Il est important que les medecins et les fumeurs comprennent bien cette distinction, car les TNS sont efficaces et presentent beaucoup moins de danger pour le fumeur, meme dans les populations a risque (grossesse, maladies pulmonaires et cardiovasculaires), et meme si certains fumeurs continuent de fumer en l'utilisant.
Les effets de la nicotine sur le systeme nerveux central sont importants pour la comprehension du... more Les effets de la nicotine sur le systeme nerveux central sont importants pour la comprehension du phenomene de dependance au tabac. Les etudes realisees au cours des annees 70 et 80 montrent un effet facilitateur sur les fonctions cognitives (attention, apprentissage, temps de reaction, resolution de problemes). Cependant, beaucoup d'erreurs methodologiques rendent ces experiences difficiles a interpreter. La publication d'un numero special de la revue Psychopharmacology en septembre 92 semble temoigner un regain d'interet pour ce domaine cognitif. Il reste cependant des questions a eclaircir. L'une est de savoir si l'effet de la nicotine sur le cerveau est direct ou indirect (du au comblement d'un syndrome de sevrage deteriorant les performances)
Réduction de consommation tabagique et abstinence temporaire : de nouvelles approches pour l'arrê... more Réduction de consommation tabagique et abstinence temporaire : de nouvelles approches pour l'arrêt du tabac.
Journal de Gynécologie Obstétrique et Biologie de la Reproduction, 2005
Question 3 Comment prendre en charge les femmes fumeuses ? Quelles sont les interventions efficac... more Question 3 Comment prendre en charge les femmes fumeuses ? Quelles sont les interventions efficaces d'aide à l'arrêt du tabac chez la femme enceinte ?
The primary reason why there is such a heavy burden of tobacco smoking induced illness and death ... more The primary reason why there is such a heavy burden of tobacco smoking induced illness and death is dependence on nicotine which makes it difficult for smokers to quit. For clinical or research purposes, the degree of dependence, the intensity of the withdrawal syndrome and/or craving have been evaluated by different scales. This review provides a list of questionnaires that are used in smoking cessation. It pays particular attention to the validated and translated resources that are available in French. Research should be conducted in order to provide French speaking smoking cessation specialists with all the relevant scales allowing better evaluation of tobacco dependence.
Journal de gynécologie, obstétrique et biologie de la reproduction, 2005
Tobacco smoking during pregnancy is the single largest modifiable risk for pregnancy-related morb... more Tobacco smoking during pregnancy is the single largest modifiable risk for pregnancy-related morbidity and mortality. Tobacco smoke contains thousands of chemicals, many of which may contribute to reproductive toxicity. Carbon monoxide is the most biologically significant toxin for the fetus. The use of nicotine replacement therapy is probably not without risk, although the magnitude of risk to the mother and fetus is much lower than continuing smoking. Most pregnant women are motivated to stop. It is, therefore, a good time to initiate smoking cessation as early as possible during pregnancy, and to maintain abstinence during post-partum to protect the infant from passive smoking. If behavioral intervention fail to produce abstinence, a sign of high dependence, nicotine replacement therapy should be initiated promptly. Although bupropion is not recommended during pregnancy, this therapy should be considered when contraindications are carefully observed. It is recommended that all pa...
The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease, 2003
Smoking is a complex behaviour involving both pharmacological and psychological components. Nicot... more Smoking is a complex behaviour involving both pharmacological and psychological components. Nicotine is the main alkaloid found in tobacco, and is responsible for its addictive potential. Nicotine-positive effects on mood and cognition are strong reinforcements for smokers that contribute to their addiction, and cigarette smoking is particularly addictive because inhaled nicotine is absorbed through the pulmonary venous rather than the systemic venous system, and thus reaches the brain in 10-20 seconds. As the likelihood that a substance will be abused depends on the time between administration and central reinforcement, tobacco smoking can easily become addictive. Nicotine replacement therapy (NRT) is available in different forms (gum, transdermal patch, nasal spray, inhaler, sublingual tablet and lozenge), and has been shown to relieve withdrawal symptoms and to double abstinence rates compared to placebo. Most NRT forms deliver nicotine more slowly than smoking, and the increase ...
Uploads
Papers by J. Le Houezec