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Biomedical subjects

P Boyer

Publications and source records attributed to P Boyer.

At least 127 records · Page 7Linked to original sources
PubMed1983

[Biochemistry and pharmacology of benzamides].

The pharmacologic characteristics of the action of benzamide derivatives on the central nervous system are discussed, with sulpiride as the reference agent. The pharmacologic study of sulpiride includes the study of its effects on animal behaviour and of the biochemical modifications in the central monoaminergic systems. In animals, sulpiride has a strikingly atypical action, with no cataleptigen effects except at high dosages, a dissociated antagonism towards the effects of apomorphine and activating effects at low dosages. A dissociated antagonism towards the effects of sulpiride on the central monoaminergic receptors results in a typical neuroleptic pattern at high dosages, with a predominating action on mesolimbic structures at low dosages. As for its action on central dopaminergic receptors, sulpiride shows a high affinity for mesolimbic structures and for structures which are not included in the blood-brain barrier: it has no effect on DA receptors bound to adenyl-cyclase; it activates at low dosages (by blocking inhibiting receptors) and inhibits at high dosages (by blocking activating receptors); it has no extrapyramidal effects; according to Schwartz, Costentin et al., it would block D2 and especially D4 receptors in the mesolimbus and striatum at low dosages and striatal D2 receptors at high dosages. In the last chapter, the other benzamide derivatives are discussed relatively to sulpiride.

Animals↗
PubMed1983

Placebo use in clinical trials on psychotropic drugs in France.

The use of placebos is often justified in therapeutic drug testing. They may be employed in order to compare their effects with those of a so-called active treatment, to compare two active medications, in double-blind comparisons of two drugs of different appearance (double-dummy technique) or to carry through initial washout periods. Although the scientific justification for this procedure is hardly contestable, the methodological difficulties and demands must be considered. The clinical use of placebo comparison poses a true ethical dilemma which increases with the effectiveness of psychotropic drugs. Placebos were used relatively rarely in France before 1978 as a general review of 120 controlled psychotropic drug trials published in French shows. Various precautions undertaken in drug testing designs respond, nevertheless, to both ethical and methodological demands in the majority of the cases. Examples are given regarding the testing of major or minor tranquilizers and antidepressive drugs.

Anxiety Disorders↗
PubMed1983

[Plasma concentrations and clinical activity of benzodiazepines].

After ingestion of equal doses of a given benzodiazepine serum concentrations vary greatly from one individual to another, suggesting that it may be advisable to monitor circulating drug levels. But so far, few studies have been conducted on the relation between benzodiazepine serum concentrations and clinical results. In general, these studies conclude that there is no significant relation between circulating drug levels and anxiolytic activity. On the other hand, the kinetic properties of benzodiazepines determine the type, rapidity of onset and duration of action of each drug. Onset of action depends on the speed of absorption of the product, and duration of action depends on how widely it is diffused. After administration of repeated doses of a benzodiazepine, accumulation of the drug depends on its half-life of elimination and metabolic clearance. Finally, the side-effects of benzodiazepines are often related to their concentrations in the plasma, but in cases of massive intoxication, there is often a dissociation between drug serum levels and the clinical picture.

Administration, Oral↗
PubMed1981

[Anatomy of intradural anastomoses between cervical nerve roots (authors' translation)].

In cases of cervical radiculopathy manifested by neural deficit, the exact localization of nerve root compression is hampered by anatomical variations such as anastomoses between bundles of adjacent segmental nerve roots inside the dural sac. A dissecting microscope study of the microsurgical anatomy of cervical nerve roots was carried out on 23 spinal cords, and four types of anastomoses were described. On the basis of embryological observations, the occurrence of such connections between neighboring posterior nerve roots can be explained.

Humans↗
PubMed1980

[Pharmacokinetics and plasma concentration of polycyclic antidepressants. General review of the product].

To date 39 studies have been published on the relationships between the plasma levels of polycyclic antidepressants and their clinical efficacy. The results of 24 of these studies show significant relationships to variable degrees. No correlation was found in the others 15. This quota does not seem to be changed by preliminary results of studies not yet published. The particular analysis of 34 of these studies indicates that plasma levels of two tricyclic (nortriptyline and imipramine) are unequivocally related to clinical efficacy (plasma levels of imipramine are the results of imipramine and desipramine cumulated levels). The correlations are the highest for non delusionnal endogenous depressions. The results are contradictory for amitriptyline, a fact which may be attributed to methodological discrepancies such as: the choice of diagnositc criteria, the choice of sampling week, the number of samples, the sensitiveness and the specificity of the analysis. More recents drugs (butriptyline, maprotiline, mianserine, etc.) have led to a limited number of studies, yet insufficient to allow conclusions. The neuroleptic association increases the plasma levels of polycyclic antidepressants. Benzodiazepines do not change them whereas all the hepatic enzymaic inductors decrease them.

Antidepressive Agents↗
PubMed1978

[Biorheologic study of pathological synovial fluids].

Rheometric studies of 34 synovial fluids done using a rheometer with a cone and stage (Shirley-Ferranti type) showed that arthrotic synovial fluids had pseudoplastic characteristics (non-Newtonian) but in inflammatory rheumatisms, the characteristics index rises, the consistency decreases and the fluid tends to loose its pseudoplastic properties and to become Newtonian. Radioisotope synoviorthosis seems capable of restoring to a certain extent and in certain cases the rheometric characteristics of the pseudoplastic properties.

Adolescent↗
PubMed1978

[Somatic disorders and depressive states].

Somatic disorders in depression can be separated into two main categories. The first comprises those which are true side effets of drug-therapy; the other includes somatic symptoms of the depression itself, which are subsequently considered as apparent side effects. Under the same treatment true side effects occur much more frequently in psychogenic depression, especially if the patient has a personality disorder. During the course of the treatment the disappearance of somatic complaints is noticed more easily by the physicians than the appearance of true side effects (schulterbrandt). The relative frequency of symptoms of depression as compared with all other symptoms seems to be higher in manic-depressive psychoses than in other varieties of depression (Watts). The other somatic disorders might either be symptoms of organic illness with secondary depression, the psycho-somatic equivalents of depression, or finaly the only symptoms of a masked depression.

Amitriptyline↗
PubMedDate not supplied

Research diagnosis of current depressive disorder: a comparison of methods using current symptoms and lifetime history.

Data from the WHO international study of Psychological Problems in General Health Care were used to compare two alternative algorithms for diagnosing current major depression using the Composite International Diagnostic Interview: the traditional method based on lifetime diagnosis and an alternative method based on number of current symptoms. Using DSM-IV criteria for current major depression, 6.2% of 5394 primary care patients were diagnosed by both methods, 2.0% by the lifetime-based method only, and 1.9% by the current symptom method only. Measures of severity (current symptoms, lifetime symptoms, disability, and comorbid anxiety) indicated that those diagnosed by only one method were only slightly less ill than those diagnosed by both. While the symptom-based method identifies a slightly more ill group, use of either method alone may exclude many who differ little from those classified as cases.

Adult↗
PubMedDate not supplied

Anhedonia and negative symptomatology in chronic schizophrenia.

The relationships between negative symptomatology and anhedonia have been studied on 61 subjects who had Research Diagnostic Criteria for chronic schizophrenia. Negative symptomatology was rated by the negative subscales of the Kay Positive and Negative Syndrome Scale (PANSS) and of the Brief Psychiatric Rating Scale (BPRS). Anhedonia was rated by the Physical Anhedonia Scale of Chapman (PAS), the Fawcett-Clark Pleasure Capacity Scale-Physical Pleasure (FCPCS-PP), and the social interest subscale (SIS) of the Nurse Observation Scale for Inpatients (NOSIE-30). Pearson correlations were calculated between negative and anhedonia scales. Schizophrenics were dichotomized first into negatives and positives using the composite score of the PANSS, and second into low and high negatives using the negative subscale of the PANSS. For each dichotomy, the corresponding subgroups were compared on anhedonia scales using Student's test. The results have shown no significant correlations between negative and anhedonia scales (PAS and FCPCS-PP). There were no significant differences concerning the PAS and the FCPCS-PP between negative and positive subgroups of schizophrenics and between low- and high-negative subgroups. Anhedonia is not a negative symptom. Our results confirm the reported studies on subjective experiences in schizophrenia. A search for more restricted forms of schizophrenia characterized by severe anhedonia is needed.

Adult↗
PubMedDate not supplied

[Morningness-Eveningness for Children Scale: psychometric properties and month of birth effect].

There is strong evidence that individuals can be arranged on a continuum from Eveningness to Morningness reflecting their preferred time range for different activities. This preference, which mostly reflects the phase of the circadian pacemaker, is determined in part by mutations on the CLOCK gene, and by environmental factors such as the month of birth. It has been suggested that eveningness might be a susceptibility factor for depressive disorders. Two self-rated questionnaires are available (the Morningness-Eveningness Questionnaire, MEQ, and the Composite Scale for Morningness) and have been adapted for use with youngsters: the Junior-MEQ and the Morningness-Eveningness Scale for Children (MESC), respectively. Most studies concern adult samples, but it is accepted that puberty is associated with a phase delay in the circadian pacemaker die a shift towards eveningness) occuring around age 12 in both genders. In this study, we examined the psychometric properties of the French version of the MESC in 3 independent samples of adolescents (total n = 392) recruited in the community or during hospitalization in paediatric department, most of them after they attempted suicide. A three-way ANCOVA showed no gender or age effect but rather a strong group effect: hospitalized adolescents scored about 3 points below the community samples (ie towards an eveningness tendency). In each sample, the internal consistency for this 10-item measure was satisfactory (mean alpha = 0.76) and the same two-factor structure was found (Morningness and Planification) as shown by procrustes rotations. As expected, there was a negative correlation between the MESC scores and reported times of rising, of going to bed, of best intellectual and physical performances, but no correlation with the number of minutes of sleep needed. The test-retest stability was acceptable within a 8-month delay although the sample size was limited (n = 20). In line with literature data, we found a modest negative correlation about -0.20 in 2 of the samples with two depression measures (MADRS and CES-D). Finally, we assessed the effect of the month of birth on the MESC total score by a non-linear regression adjusted for age and gender that included a one-cycle cosinus function. We found that birth in March-April was associated with eveningness while birth in September-October was associated with morningness. The peak and nadir occur two months before those found in a large sample of young adults. However, this result could not be replicated in the sample of hospitalized adolescents suggesting that the effect might have been smoothed by a "pathological" factor. Reasons for this descrepancy and implications for developmental psychiatry are discussed. More precisely, we postulate a relationship between morningness and impulsivity-related personality traits. In conclusion, the MESC is a psychometrically sound instrument in need of further validity assessment.

Adolescent↗
PubMedDate not supplied

[Clinical and therapeutic characteristics of social phobia in French psychiatry (Phoenix study)].

Only few clinical epidemiologic studies have been conducted on social phobia in France to date. It is however a frequent disorder, with often severe alteration of social adaptation and quality of life, and for which effective treatments exist. Thus, it seems really important to further explore how these patients are nowadays identified and treated in psychiatry. It was the objective of the Phoenix study. In this observational multi-center study, 952 psychiatric in- or out-patients, with a primary diagnosis of social phobia according to DSM IV criteria, were included. Numerous diagnostic and psychometric evaluations were carried out, in order to evaluate the comorbidity (Mini International Neuropsychiatric Interview, Hospital Anxiety and Depression Scale), the intensity of social anxiety (Liebowitz Social Anxiety Scale), and various aspects of the functional and emotional impact (Various Impact of Social Anxiety scale, Sheehan Disability Scale, SF-36, Positive and Negative Emotionality scale). The patients were in majority females (57.6%), with a mean age 37.5 years, and with a mean duration of social anxiety disorder 12.5 years. The mean scores of social anxiety on Liebowitz scale was 40.3 +/- 12.6 for the fear factor, and 38.3 +/- 13.6 for the avoidance factor. The generalized social anxiety subtype (anxiety in most social situations) was present in 67.8% of the patients. A major depressive disorder was found in 47.7% of the sample, and the prevalence of agoraphobia was even higher (49.2%). As known in clinical practice and in other studies, the prevalence rates of current alcohol dependence and substances abuse were also important in this population (respectively 10.6% and 12.7%). Mean scores of the Hospital Anxiety and Depression (HAD) sub-scales were 13.9 +/-3.8 for anxiety and 9.1 +/-4.5 for depression. About 15% of the patients had a history of suicide attempt, and a suicidal risk was present in nearly 40% of the sample. The psychosocial impact and the alteration of quality of life (with especially a poor physical health perception) were very significant, in the family, educational or occupational and social domains. Mean scores of the Sheehan Disability Scale were 6.1 +/- 2.6 for professional impairment, 5.0 +/- 2.7 for familial impairment, and 6.6 +/- 2.3 for social life impairment. In addition to the disability due to social phobia intensity, an important part of the burden was due to depressive symptoms. Approximately 60% of the patients had already a psychiatric treatment at the time of the survey (since 1,7 years in average), but only 17% had a cognitive behavioral therapy (CBT), and 48% had an antidepressant treatment. These proportions increased in a significant way after the consultation during which the investigation was carried out: an antidepressant was prescribed to 72% of the patients, and a CBT is proposed to 48%. On the whole, this study confirmed the severity and the morbidity of social phobia in a very large sample of French psychiatric patients. The depressive disorders, suicidal risk, and social impairment associated with this condition should incite to more detect and treat it. Seeing the long duration of the disease in our sample, and the lack of specific therapies in many cases, the identification and the treatment of social phobia must be improved, and the role of the psychiatrists in this process seems very important.

Adult↗
PubMedDate not supplied

Dysthymia: clinical picture, extent of overlap with chronic fatigue syndrome, neuropharmacological considerations, and new therapeutic vistas.

Dysthymia, as defined in the American Psychiatric Association and International Classification of Mental Disorders, refers to a prevalent form of subthreshold depressive pathology with gloominess, anhedonia, low drive and energy, low self-esteem and pessimistic outlook. Although comorbidity with panic, social phobic, and alcohol use disorders has been described, the most significant association is with major depressive episodes. Family history is loaded with affective, including bipolar, disorders. The latter finding explains why dysthymia, especially when onset is in childhood, can lead to hypomanic switches, both spontaneously and upon pharmacologic challenge in as many as 30%. Indeed, antidepressants from different classes -tricyclic antidepressants (TCAs), monoamine oxidase inhibitors (MAOIs), reversible inhibitors of monoamine oxidase A (RIMAs), selective serotonin-reuptake inhibitors (SSRIs) and, more recently, amisulpride, and spanning noradrenergic, serotonergic as well as dopaminergic mechanisms of action - have been shown to be effective against dysthymia in an average of 65% of cases. This is a promising development because social and characterologic disturbances so pervasive in dysthymia often, though not always, recede with continued pharmacotherapy beyond acute treatment. Despite symptomatic overlap of dysthymia with chronic fatigue syndrome - especially with respect to the cluster of symptoms consisting of low drive, lethargy, lassitude and poor concentration - neither the psychopathologic status, nor the pharmacologic response profile of the latter syndrome is presently understood. Chronic fatigue today is where dysthymia was two decades ago. We submit that the basic science - clinical paradigm that has proven so successful in dysthymia could, before too long, crack down the conundrum of chronic fatigue as well. At a more practical level, we raise the possibility that a subgroup within the chronic fatigue group represents a variant of dysthymia.

Antidepressive Agents↗
PubMedDate not supplied

[Contribution of electromyography to the diagnosis of acute radicular or medullary cervical disc palsies (author's transl)].

Operative treatment was employed in 38 patients with cervical disc lesions. These had produced either compression of spinal cord nerves, especially C6 or C7 (22 cases), or cervical ischemic lesions (16 cases) of the centromedullary region, either isolated or associated with symmetrical, bilateral cord lesions. A study of pre- and post-operative clinical and electromyographic correlations enabled differentiation of acute cervical radioculopathies from myelopathies and definition of their progression as a function of the surgical treatment employed.

Acute Disease↗