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Biomedical subjects

P Bovier

Publications and source records attributed to P Bovier.

At least 37 records · Page 2Linked to original sources
PubMed1992

Platelet membrane alpha 2-adrenergic receptors in depression.

The platelet membrane was used as a model system to examine alpha 2-adrenergic receptors in 30 depressed patients and 30 healthy control subjects. The number of binding sites and their affinity for 3H-UK 14304 (5-bromo-6-(2-imidazoline-2-ylamino)-quinoxaline), a potent, highly selective alpha 2-adrenergic receptor agonist, was measured. Plasma magnesium and free 3-methoxy-4-hydroxyphenylglycol (MHPG) concentrations were assayed in the same sample. A decreased agonist-receptor affinity was found in depressed patients, whereas receptor density was not significantly altered compared with that in control subjects. In bipolar depressed and dysthymic patients, there was a tendency toward a higher density of alpha 2-adrenergic receptors. This trend was not apparent in unipolar, recurrent depressed subjects. Moreover, a positive correlation between Bmax and Kd values was observed in patients but not in control subjects--a finding that suggests that a compensatory phenomenon occurs in depression. After the patients were treated with antidepressant drugs, an increased affinity (decrease in Kd) was observed, together with a decrease in binding sites. Plasma magnesium concentrations were higher in drug-free depressed patients than in control subjects. In addition, magnesium concentrations were negatively correlated with the density of alpha 2-adrenergic receptor binding sites in depressed patients, both before and during treatment. Lastly, a trend toward a negative correlation between plasma MHPG concentration and the number of binding sites was also observed. These results suggest a complex multifactorial regulation of alpha 2-adrenergic receptors, which are probably hyposensitive in depressive syndromes.

Adrenergic alpha-Agonists↗
PubMed1992

Decrease in epinephrine-induced attenuation of platelet adenylate cyclase activity in depressed patients: relation with plasma electrolytes.

We have measured the alpha 2-adrenoceptor-mediated inhibition of platelet membrane adenylate cyclase in depressed patients and control subjects. The results showed a decrease in the forskolin-stimulated adenylate cyclase inhibition of depressed patients compared to the healthy subjects. This suggests a subsensitivity of alpha 2-adrenoceptor in depression. However, this subsensitivity was not correlated to the severity of depression as both severely and moderately depressed patients exhibited the same percent of adenylate cyclase inhibition. The antidepressant drugs treatment induced an increase in the percent of adenylate cyclase inhibition with a trend towards the control values. However, this increase did not equal control value, and moreover both remitted and unremitted patients presented a similar change in their alpha 2-adrenoceptor-mediated adenylate cyclase inhibition. This result raises the question about a simple and direct relation between the clinical status of depression and the power of alpha 2-adrenoceptor-mediated adenylate cyclase inhibition. Plasma magnesium and sodium yielded correlations to this alpha 2-adrenoceptor-mediated adenylate cyclase inhibition suggesting a relation between the platelet adrenergic function and plasma electrolytes.

Adenylyl Cyclase Inhibitors↗
PubMed1992

Evolution of blood magnesium, sodium and potassium in depressed patients followed for three months.

No consensus has been obtained about blood electrolyte status, especially about magnesium, in affective disorders. This is mainly due to the lack of information about the distribution of the patients in clinical subgroups, sex, type of treatment and about the severity of their illnesses. Most of these studies concerned treated patients. We confirmed in this study that drug-free depressed patients have higher erythrocyte and plasma magnesium than controls, as shown in previous reports. Significant differences are observed in as shown in previous reports. Significant differences are observed in patients for sex and between clinical subgroups. Low plasma potassium levels are described in both male and female depressed patients. The erythrocyte magnesium level tends to normalize in parallel with clinical improvement, depending on sex and clinical subgroup, and seems then to be related to the intensity of the depression. Plasma magnesium in male and female patients, except for female unipolars, remains higher than controls in all conditions and might be related to the diagnosis of affective disorders.

Adult↗
PubMed1991

Neuropathological observations in a case of autism presenting with self-injury behavior.

We report the neuropathological evaluation of a 24-year-old autistic woman suffering from a residual state of infantile autism and presenting with self-injury behavior since childhood. Her behavior included head-banging, eye-gouging and self-biting. All intended therapeutic measures remained without effect, including high doses of psychotropic drugs. At autopsy, numerous neurofibrillary tangles were found in the perirhinal and entorhinal cortex where they were frequently grouped in nests or clusters. A few neurofibrillary tangles were also observed in the amygdala and in the prepiriform and orbito-frontal cortex. In the cortex, tangles were located in both layers II and III. There were no neuritic plaques or amyloid deposits. Interestingly, neurofibrillary tangles have been described in brains of individuals who had experienced repeated head injuries such as boxers (dementia pugilistica) and soccer players, suggesting that in our case a similar mechanism induced tangle formation and resulted in the loss of selective neuronal populations.

Adult↗
PubMed1990

L-tyrosine and L-tryptophan membrane transport in erythrocytes and antidepressant drug choice.

In the treatment of depression, when antidepressant drug choice is made according to alterations of erythrocyte membrane transport of L-tyrosine and L-tryptophan in the individual patient, the clinical results are superior to those obtained when drugs are prescribed according to the physician's judgment. This is demonstrated by comparing three experimental groups: I, 100 patients treated in relation to their L-tyrosine and L-tryptophan transport; II, 30 patients treated according to the clinician's experience; III, 38 subjects treated against the L-tyrosine and L-tryptophan transport indications. In these groups, the frequency of patients improved by more than 70% is 77%, 47%, and 16%, respectively.

Adult↗
PubMed1990

A multivariate analysis of red blood cell membrane transports and plasma levels of L-tyrosine and L-tryptophan in depressed patients before treatment and after clinical improvement.

The purpose of this study was to examine whether biological variables, such as erythrocyte membrane transports and plasma levels of monoamine precursor amino acids (tyrosine, tryptophan and phenylalanine), exhibit a particular pattern relatively to DSM-III depressive subgroups (dysthymic disorders, major recurrent depression and biopolar depression), when they are treated synthetically by a stepwise discriminant analysis. We conducted two tests in 97 subjects (64 depressed patients vs. 33 controls): the first before any antidepressant treatment, and the second after pharmacotherapy and clinical improvement. Our results clearly indicate a satisfying homogeneity for the controls and bipolar depressed patients as opposed to dysthymic disorders and major recurrent depression in both tests. The most informative biological variables are the erythrocyte membrane transports before treatment, tryptophan parameters after clinical improvement. Evidence is provided that multivariate analysis constitutes an interesting approach in biological psychiatry.

Adult↗
PubMed1989

The heterogeneity of 3-methoxy-4-hydroxyphenylglycol levels among depressed patients.

A previous report by our group and results published by other research groups have indicated a dichotomy in MHPG levels in depressed patients. This study attempted to characterize phenomena associated with this dichotomy in plasma MHPG levels. First, we have noted, at least in female patients, that homogeneity of MHPG levels, as tested by fitting with a normal curve, can be ruled out. In contrast, in the total population, a dichotomy was less evident in this study; the 2 subgroups, high and low levels of MHPG, partially overlap, and this results in a gaussian distribution. However, based on the hypothesis of a bimodal distribution, as shown by others and not excluded here, it was possible to find some factors associated with heterogeneity. Thus, polarity of depression, sex and age of the patients, age of disease onset and depression score affect MHPG levels. On the other hand, other elements suspected to modify MHPG values, such as the different lengths of the washout period (minimum 10 days), or some medication (chloralhydrate or levomepromazine) required during the washout period, did not show any effect. The aim of this study was to better characterize this peripheral index for its possible use in clinical application.

Adult↗
PubMed1989

Involvement of sulfhydryl groups in the transport of L-tyrosine and L-tryptophan across the human red cell membrane in vitro.

In previous papers, we reported a deficit in tyrosine (TYR) and tryptophan (TRP) transport across the erythrocyte membrane in depressed patients. To investigate further the transport mechanism of the two precursors of monoamines, we tested in healthy subjects the role played by sulfhydryl groups (SH). These groups, cysteine residues, are localized on the intrinsic domain such as the transporters of chloride or sugars. We found that all sulfhydryl reagents that inactivated the SH induced a strong inhibition of the transport of amino acid across the red cell membrane when incubated in the plasma as medium. We concluded that a relationship might exist between these neutral amino acids and D-glucose transport.

4-Chloromercuribenzenesulfonate↗
PubMed1989

[Apropos of a probable case of Binswanger encephalopathy].

The psychiatric characteristics of one highly suspected case of Binswanger's disease were discussed. The diagnosis was based on the clinical state and the CAT-scanner; this case was associated with particular psychiatric profile: a major depressive syndrome, an obsessional behavior and a major inhibition, with only slight symptoms of dementia. The psychiatric symptoms might help to the early diagnosis of this subcortical arteriosclerotic encephalopathy.

Atrophy↗
PubMed1988

Evolution of red blood cell membrane transport and plasma level of L-tyrosine and L-tryptophan in depressed treated patients according to clinical improvement.

The erythrocyte membrane transport (MT) of L-tyrosine (TYR) and L-tryptophan (TRP) and their plasma concentration showed abnormal mean values in 37 depressed patients compared to control subjects before treatment. The pattern of these abnormal values differed according to the clinical subgroup (DSM III criteria). In bipolar disorders the TYR values were all low and the TRP values showed little change, except a low level of plasma TRP. In major depression, MT were abnormal (MT TYR low, MT TRP high) with a very low plasma TRP. In dysthymic disorders the TYR and TRP values were normal. The normalization of the above biochemical variables was significantly correlated with the clinical improvement; however, the plasma concentration of TRP remained abnormal in some patients who had recovered. In contrast, only plasma TYR and TRP were significantly increased in patients without recovery.

Adult↗
PubMed1988

[Apropos of a case of functional dysphagia].

Isolated functional dysphagia (IFD) was rarely cited in human adults. Here we reported a case of a patient which presented IFD. A constructivist approach revealed a primacy of the assimilation and an incapacity to overcoming the difficulties. The constructivist approach permitted the disappearing of the symptom. The concept and the technic of such approach are discussed.

Adult↗
PubMed1987

The decrease of erythrocyte catechol-O-methyltransferase activity in depressed patients and its diagnostic significance.

Erythrocyte catechol-O-methyltransferase (COMT) activity was measured in normal and depressed populations before specific medication. In the groups of patients, anxiety and depression scores were evaluated by the AMDP rating scale. The authors found lower enzyme activity in patients with major depression, recurrent and bipolar disorder, depressed, but no change was found in dysthymic disorder when compared to control values. However, there was no relationship between COMT activity and age, anxiety and depression scores of patients. Furthermore, the subdivision into two subpopulations, one with normal COMT activity and another with lower COMT activity, did not make it possible to assign a role to the enzyme in the severity of depression. The enzyme could, however, be considered as a genetic marker of depressive vulnerability.

Adult↗
PubMed1985

[The speech of hebephrenic patients (maladjustment between assimilation and accommodation)].

Previous studies indicate that schizophrenic thought processes show a disturbance in the balance between assimilation and accommodation, as Piaget uses these terms. The authors postulated that this phenomenon could also account for the typical language disorders of hebephrenics, particularly semantic slippage. Every fourth word was deleted from linguistic material produced by eight controls and thirteen hebephrenics (Silverman). Three judges were then asked to fill in the blanks. The deleted words used by the subjects were compared with the replacement words chosen by the judges. The comparison revealed such disorders in hebephrenic speech as semantic alteration (metaphorical and metonymic) of the linguistic tropic type and syntax disorders including inhibition of the expansion of phrases introduced by functional monemes (morphemes), whether primary or secondary. These observations confirm those of other authors, more especially those of Roch Lecours et al. On the basis of Martinet's functional linguistics, Chomsky's generative grammar and Piaget's cognitive psychology, the authors conclude that the psychopathology underlying hebephrenic speech is a disturbance of language rather than of parole and that hebephrenic syntactical distortions are linked to the disturbance in the balance between assimilation and accommodation characteristic of schizophrenic thought processes.

Adult↗
PubMed1984

Ethyl alcohol on escape from electrical periaqueductal gray stimulation in rats.

In a procedure to measure the escape latency and threshold for aversive electrical stimulation of the Peri-Aqueductal Gray (PAG) the effect of ethyl alcohol was tested in order to validate aversive PAG stimulation further as a model for testing potential anxiolytics. Doses of 0.2-1.6 g/kg were given orally in an ascending sequence and were found to increase escape latency and threshold. A second dose of 0.8 g/kg had no effect, suggesting development of tolerance. Spontaneous activity in the test environment was not changed by alcohol. These results indicate specific effects of alcohol on aversive stimulation and reinforce the suggestion to use this phenomenon as a model for human anxiety.

Animals↗