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Biomedical subjects

P Gaillard

Publications and source records attributed to P Gaillard.

At least 37 records · Page 2Linked to original sources
PubMed1996

Selective inhibition of rat heart cAMP phosphodiesterases by lipophilic C-methyl-2-phenyl-4H-1-benzopyran-4-ones (C-methylflavones).

A series of eight methoxylated C-methyl-2-phenyl-4H-1-benzopyran-4-ones 3, 6, 10-15 was evaluated as inhibitors of rat heart cytosolic cyclic nucleotide phosphodiesterase (PDE). The 2-(3,4-dimethoxyphenyl)-5,7-dimethoxy-3,8-dimethyl-4H-1-benzopyran-4-one (3) and the 2-(4-methoxyphenyl)-5,7-dimethoxy-3,8-dimethyl-4H-1-benzopyran-4-one (10) have never been previously described. Inhibition was performed on the whole cytosolic preparation and on the four PDE isoforms after HPLC purification. The flavones 3, 6, 10, 13 and 14 were selective and potent inhibitors of the isoforms, namely ROI (rolipram-sensitive) and CGI (cGMP-sensitive) PDEs specifically hydrolyzing cAMP. The di-C-methylflavones 3 and 13 have been shown to be potent inhibitors of these two isoforms, with IC50 values in the micromolar range.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1996

Caries prevalence in 12-year-old schoolchildren in New Caledonia.

This study reports on the most recent epidemiological survey undertaken in New Caledonia, a French dependency in the South Pacific. Three hundred and twenty-five 12-year-old children were selected from schools using the World Health Organization pathfinder sampling methodology. The results showed a DMFT of 4.09. This places New Caledonia in the 'moderate' category on the World Health Organization scale of caries severity for 12-year-old children. Two oral health risk groups were identified: Melanesian and Wallisian children. Different approaches to promoting oral health in New Caledonia, taking into account local socio-cultural traditions, are proposed.

Child↗
PubMed1996

[Syndrome secondary to traumatic stress (PTSD) and addictive behaviors].

Ninety psychiatric female inpatients had an interview using structural clinical instruments. The patients were often exposed during their lifetime to psychic trauma and especially to sexual abuse in childhood (27%) and rape (21%). Rape is a risk factor for chronicity and severity of mental disorders. Post-traumatic disorders such as PTSD, dissociative disorders, somatoform disorders and borderline-like disorder are linked to rape. Addictive behavior such as alcohol abuse, drugs use, repeated suicide attempts or eating disorders, is also associated with raped patients and especially with those who developed PTSD after rape.

Adolescent↗
PubMed1995

Inhibition of monoamine oxidase-B by 5H-indeno[1,2-c]pyridazines: biological activities, quantitative structure-activity relationships (QSARs) and 3D-QSARs.

A large series (66 compounds) of indeno[1,2-c]pyridazin-5-ones (IPs) were synthesized and tested on their monoamine oxidase-A (MAO-A) and MAO-B inhibitory activity. All of the tested compounds acted preferentially on MAO-B displaying weak (nonmeasurable IC50 values) to high (submicromolar IC50 values) activities. The most active compound was p-CF3-3-phenyl-IP (IC50 = 90 nM). Multiple linear regression analysis of the substituted 3-phenyl-IPs yielded good statistical results (q2 = 0.74; r2 = 0.86) and showed the importance of lipophilic, electronic, and steric properties of the substituents in determining inhibitory potency. Various comparative molecular field analysis studies were performed with different alignments and including the molecular lipophilicity potential. This led to a model including the steric, electrostatic and lipophilicity fields and having a good predictive value (q2 = 0.75; r2 = 0.93).

Computer Graphics↗
PubMed1995

Inhibition of monoamine oxidase by isoquinoline derivatives. Qualitative and 3D-quantitative structure-activity relationships.

A series of isoquinolines, N-methyl-1,2-dihydroisoquinolines, N-methyl-1,2,3,4-tetrahydroisoquinolines, 1,2,3,4-tetrahydroisoquinolines, and N-methylisoquinolinium ions were tested as inhibitors of monoamine oxidases A and B. All compounds were found to act as reversible and time-independent MAO inhibitors, often with a distinct selectivity towards MAO-A. As a class, the N-methylisoquinolinium ions were found to be the most active MAO-A inhibitors, with N-methyl-6-methoxyisoquinolinium ion emerging as a potent (IC50 = 0.81 microM) and competitive MAO-A inhibitor. Comparative molecular field analysis (CoMFA, a 3D-QSAR method) of MAO-A inhibition was performed using the data reported here and in the literature. Using the steric and lipophilic fields of the inhibitors, quantitative models with reasonable predictive power were obtained that point to the importance of steric, lipophilic, and polar interactions in modulating MAO-A inhibitory activity.

Binding Sites↗
PubMed1995

X-ray crystal structure, partitioning behavior, and molecular modeling study of piracetam-type nootropics: insights into the pharmacophore.

To detect possible molecular determinants of amnesia-reverting activity, the conformational properties of a number of rigid and flexible piracetam-type cognition enhancers have been assessed by X-ray diffraction, NMR spectroscopy, and ab initio and high-temperature-quenched molecular dynamics (QMD) calculations. The structures of the preferred conformers in solution derived from 1H-NMR spectral analysis were in good agreement with those found by QMD calculations. Interestingly, the calculation of the average molecular lipophilicity potential on the water-accessible surface of the selected conformers was helpful in interpreting the partitioning behavior observed by measuring octanol-water partition coefficients and capacity factors in reversed-phase high-performance liquid chromatography. While lipophilicity does not play a relevant role, the distance between polar groups, accounted for by the distance between carbonyl oxygens, emerges as a factor, among others, which should influence the amnesia-reversal activity of piracetam-type nootropics.

Chemical Phenomena↗
PubMed1995

Sexual victimization in women with schizophrenia and bipolar disorder.

Exposure of populations with psychosis to traumatic events (among them sexual trauma) has seldom been studied. In addition, the clinical features developed by victims with psychosis after a traumatic event are rarely taken into account. Sixty-four women with schizophrenia and 26 women with bipolar disorder (DSM-III-R diagnosed, 18-45 years, inpatients and outpatients) were interviewed using a clinician-rated battery of instruments, including a semi-structured questionnaire concerning sexual victimization and its impact. In childhood or adolescence, 36% of women with schizophrenia (vs 28% of those with bipolar disorder) had been victims of sexual abuse involving body contact. In the women with schizophrenia, this sexual abuse was associated with addictions, suicide attempts and becoming psychiatric patients earlier. Over their lifetime, the prevalence of rape was 23% in the two clinical groups. In women with schizophrenia, rape was associated with a greater severity of their disorder and addictions. Moreover, a frequent repetition of sexual trauma was observed in women with schizophrenia, whereas such repeated traumas were less frequent in those with bipolar disorder. The results suggest that these two clinical groups are at risk of rape and the study highlight clinical features in victims with schizophrenia that have been described for other groups of victims of sexual abuse.

Adolescent↗
PubMed1995

Stabilization of the hydrophilic sphere of iobitridol, an iodinated contrast agent, as revealed by experimental and computational investigations.

PURPOSE: The regular distribution in space and the stability in time of the hydrophilic sphere surrounding iobitridol were investigated. This is a novel yet important concept in the design of polyiodinated contrast agents since such a sphere is meant to hide their hydrophobic core and thus prevent hydrophobic interactions with biomacromolecules and hence chemotoxicity. METHODS: The methods used were experimental (HPLC, 1H- and 13C-NMR spectroscopy) and computational (calculation of conformational behavior and molecular electrostatic potentials). RESULTS: Iobitridol exists as a mixture of stereoisomers due to hindered rotation around several bonds. High-temperature molecular dynamics established the existence between 0 and 15 kcal/mol of 238 conformers belonging to 14 classes. Most of these conformers have an inaccessible hydrophobic core, and variable temperature molecular dynamics confirmed that the hydrophilic sphere around iobitridol is stable against external disruption. CONCLUSIONS: This study has demonstrated that iobitridol fulfils the physicochemical and structural criteria believed to render a polyiodinated contrast agent inert toward interacting with biomacromolecules.

Chemical Phenomena↗
PubMed1995

ECG activity in the sleep of insomniac patients under the influence of lormetazepam and zopiclone.

The influence of the benzodiazepine hypnotic lormetazepam (1 mg) and the cyclopyrrolone hypnotic zopiclone (7.5 mg) on heart rate activity was studied in 16 elderly insomniacs in a placebo-controlled, randomised, 3-fold crossover trial. After digital preprocessing of the ECG, QRS complexes were automatically recognised by a detection technique based on adaptative thresholds. Both R-R periodicity and heart rate variability were analysed as a function of sleep stages and time of night. Under placebo, heart rate decreased significantly from the first to the second half of the night. The relationship between sleep stages and heart rate remained constant under both hypnotics. Although the two substances significantly modified the distribution of sleep stages, no relevant changes in ECG activity were observed when the proportion of the different sleep stages was taken into consideration.

Aged↗
PubMed1995

[Psychotic women and their children].

With desinstitutionalization, the social life of psychiatric patients and particularly that of psychotics has arisen in new terms over the past twenty years. In particular, relationships and sexuality of these patients are manifest realities to which few studies are devoted. 61 schizophrenic and 21 bipolar women (18-45 years of age, mean 34 in-or outpatients) were interviewed with a battery of instruments (PANSS, Carpenter's criteria of schizophrenia with deficit syndrome, axis V of DSM-III-R) and with a semi-structured questionnaire related to clinical data, sexuality, relationships, children and motherhood. Half of the schizophrenic women have an active sexual life, and children. The study provides information about the reproduction rate of schizophrenic women, the precocity of their pregnancies and the outcome of their children. The study also treats these women's ability to rear their children, their desire to have children and any hospitalizations during the perinatal period. These results, as well as those related to abortion and contraception, are discussed in the light of those of the bipolar control group.

Adolescent↗
PubMed1995

[Psychological trauma and mental disorders].

Fifty-eight female impatients consecutively hospitalized in the University Hospital Department of Psychiatry in Tours were interviewed with a clinician battery of instruments (among them, the SI-PTSD by Davidson). The diagnoses leading to hospitalization were: severe disorders of psychotic type (schizophrenic, schizophreniform, schizo-affective, schizoid and paranoid delusional disorders as well as bipolar disorder), borderline and narcissistic personalities for 7%, and other disorders for 53%. Among the results, we observed that 59% of these patients had experienced at least one major stressful event (rape 26%, other sexual assault 29%, physical assault 31%, seeing somebody dying in a violent way 8%, war scene 2%, injured in an accident 2%). As a consequence, 61% of the victims have suffered from PTSD and the diagnosis of PTSD was still present in 21%. In addition, in the victims, somatoform and dissociative disorders were significantly more frequent.

Adult↗
PubMed1995

[Role of psychiatry in the preoperative phase of facial reconstructive surgery].

Nowadays, the place of psychiatrist is currently admitted in facial plastic surgery, but is still discussed in reconstructive surgery. This page will stress the importance of a cooperation between surgeon and psychiatrist, preoperatively in orthognathic surgery. After a brief review of literature, we will try to precise when psychiatrist's advice would help, preoperatively, maxillofacial surgeon. On the other end, we will see that psychiatrist having in charge patients with major facial deformity can head them to undergo a reparatrice surgery. A clinical case will end this paper.

Adult↗
PubMed1994

Molecular lipophilicity potential, a tool in 3D QSAR: method and applications.

A new method is presented to calculate the Molecular Lipophilicity Potential (MLP). The method is validated by showing that the MLP thus generated on the solvent-accessible surface can be used to back-calculate log P. Because the MLP is shown to be sensitive to conformational effects, the MLP/log P relation is best sought by taking all conformers into account. The MLP method presented here can be used as a third field in CoMFA studies, as illustrated with two series of alpha 1-adrenoceptor ligands. In the first series, the steric, electrostatic and lipophilic fields are highly intercorrelated, and taken separately yield comparable models. In the second series of ligands, the best model is obtained with the lipophilic field alone, allowing insights into ligand-receptor interactions.

Adrenergic alpha-Agonists↗
PubMed1994

Automatic analysis of sleep using two parameters based on principal component analysis of electroencephalography spectral data.

A computer program for the analysis of a sleep electroencephalogram (EEG) is presented. The method relies on two steps. First, a spectral analysis is performed for signals recorded from one or more electrode locations. Then, two EEG parameters are obtained by storing the spectral activity in a multidimensional space, whose dimension is reduced using principal component analysis (PCA) techniques. The main advantage of these parameters is in describing the process of sleep on a continuous scale as a function of time. Validation of the method was performed with the data collected from 16 subjects (8 young volunteers and 8 elderly insomniacs). Results showed that the parameters correlate highly with the hypnograms established by conventional visual scoring. This signal parametrisation, however, offers more information regarding the time course of sleep, since small variations within individual sleep stages as well as smooth transitions between stages are assessed. Finally, the concurrent use of both parameters provides an original way of considering sleep as a dynamic process evolving cyclically in a single plane.

Adult↗
PubMed1994

Three dimensional representation of brain electrical activity.

Brain topography mapping is a useful technique for the representation of electrical activity recorded on the scalp. It clarifies spatial and temporal relationships between different cortical areas. In this work we propose a system which includes several enhancements over those previously proposed, such as an optimised interpolation method and a three dimensional reconstruction of maps. This system is available in a personal computer environment. Results clearly show a superiority of the 3D representation over 2D maps obtained with different projections. The performance of this system in terms of speed and precision is comparable to that of dedicated image processing and image synthesis workstations proposed for brain mapping.

Brain↗
PubMed1994

[Treating psychic traumas: a psychiatric emergency].

Interest for the psychopathological field of trauma has experienced a revival over the last fifteen years. Early and active treatment of victims is necessary to attenuate the psychopathological consequences of trauma. However, emergency psychiatry still rarely places a high value on it. This paper presents a case which contains in itself many aspects of psychological responses to psychologically traumatizing events. Trauma induced in this case, in particular, Dissociative Disorders (including a Dissociative Fugue), a Post-Traumatic Stress Disorder, Somatoform Disorders and Phobic Disorders. This case gives us the opportunity to situate the psychiatric emergency--"psychological trauma"--and to illustrate our talk with regard to the principles of mid-term and emergency treatment of victims.

Adult↗