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J M Launay

Publications and source records attributed to J M Launay.

At least 199 records · Page 11Linked to original sources
PubMed1979

[The platelet model applied to the study of depressive illness (author's transl)].

The blood platelets, which serious arguments permit one to consider as valid models of serotoninergic neurones, were studied in various types of depression and during treatment with antidepressor drugs. The modifications of several platelet parameters were analysed in particular. The level of hydroxyndoles (OH-5-tryptamine or 5-HT for example) is generally lowered. The uptake of 5-HT is also reduced with normalisation by antidepressor treatments; the fixation of mepacrine, sign of the passive uptake of bioamines, is modified in the same direction, especially, in our experience, in maniacs, with a rise during treatment with phenothiazines. Finally, among the platelet enzymes, monoamine oxidase has a reduced activity in bipolar depressed patients, certain maniac depressive psychosis, and endogenic melancholias. Other platelet parameters, (liberation or release, nucleotide levels, 5-HT bonds at membrane level, etc.) may provide in the future, interesting information. In spite of sometimes contradictory data, the platelet model may be of interest, especially from pharmacological point of view.

Antidepressive Agents↗
PubMed1977

Blood platelet and "extra-platelet" serotonin in some myeloproliferative disorders.

Most of the blood serotonin is bound to platelets. However, some authors described plasma "free" serotonin; which is normally very low, and might be increased during some diseases. Usual spectrofluorimetric methods and paired by statistical evaluation "extra-platelet" serotonin (not bound to platelets) in the blood of healthy volunteers and patients with myeloproliferative disorders was studied. In these conditions, we cannot be sure of the existence of "extra-platelets" serotonin in the blood of controls and some patients; in others it was present. "Extra-platelet" serotonin is always present in the blood of untreated patients with primary thrombocytosis.

Blood Platelets↗
PubMedDate not supplied

[Histamine-release and migraine].

Some studies suggested a role for histamine in the pathogenesis of the migraine. So we decided to investigate the histamine-release in two groups of patients: 8 common migraine patients, 8 healthy subjects. Plasma from either controls or migraineurs were mixed with the same control whole blood and histamine release was measured using a radio-enzymatic assay. Migraine plasma induced an histamine release significantly more important than control plasma (p less than 0.01). The nature of an "histamine releasing factor" in the plasma of migraine patient is discussed. This work is an argument for a possible immuno-allergic process in migraine.

Adult↗
PubMedDate not supplied

Plasma histamine levels and kinetics in chronic hemodialysis patients.

Pruritus is frequently observed in hemodialyzed patients; its etiology seems to be multifactorial. Increased plasma histamine levels have been reported in chronic renal failure. As histamine is a potent inducer of pruritus. The authors investigated its concentrations and kinetics in plasma of stable hemodialyzed patients.

Adult↗
PubMedDate not supplied

14-3-3 protein, neuron-specific enolase, and S-100 protein in cerebrospinal fluid of patients with Creutzfeldt-Jakob disease.

We explored simultaneously 14-3-3 protein, neuron-specific enolase (NSE), and one astroglial protein, S-100, recently proposed as Creutzfeld-Jakob disease (CJD) markers, in the cerebrospinal fluid (CSF) of 129 patients with suspected CJD. Cutoff values for NSE and S-100 were established at 25 and 2.5 ng/ml, respectively. The highest sensitivity was observed for S-100 (94.2%) followed by 14-3-3 (89.8%) and NSE (79.7%), while the highest specificity in CJD diagnosis was obtained with 14-3-3 protein (100%) as compared with NSE (91.5%) and S-100 (85.4%). No influence of sex, genotype at codon 129 of the prion protein gene, time between sampling, and death or disease duration has been found. Based on 90 cases initially referred as 'probable' or 'possible' CJD, with 14-3-3, NSE, or S-100 we could correctly discriminate between 'CJD' or 'non-CJD' categories in 94.4, 86.5, and 90% of the cases, respectively. When limited to 'possible CJD' cases, diagnosis based on one of the three CSF proteins was accurate in 98, 90.7 and 87.3%, respectively. In view of the fact that the CSF 14-3-3 protein test alone has the highest specificity and good sensitivity, it appears that there is no additional advantage at the moment to include NSE and/or S-100 protein in the exploration of clinically suspected CJD cases.

14-3-3 Proteins↗
PubMedDate not supplied

[Molecular genetics: pre- and post-analytic "best practices"].

Medical prescriptions for molecular genetic analyses are not yet very common in general practice, neverless they are becoming more and more frequent, and therefore it is more difficult to deal with them in part because of the recent french rules. Laboratory managers are supposed to be able to deal with such requests. This document, describing good laboratory practices, has been elaborated by members of the group "molecular genetics" from the "College National de Biochimie des Hôpitaux", providing details about: assessment of the prescriptions, including patient's consent, choice of the executing laboratory, specimen transmission, assessment and control of clinical and biological data, results transmission, confidentiality, archiving system. Such recommendations should facilitate exchanges with specialized laboratories, being specifically approved for practicing such analyses. The authors draw the attention of laboratory managers to the specificities of such requests.

Benchmarking↗
PubMedDate not supplied

[Platelet serotonin in infantile autism. Cross-over effects of a dopamine agonist and an antagonist].

In infantile autism, the serotoninergic (5-HT) hypothesis is corroborated by biological dosages and therapeutic effects of fenfluramine which decrease blood serotonin. However other drugs, such as dopaminergic agonists or antagonists, have therapeutic effects. Therefore, we tested the hypothesis that two dopaminergic (DA) drugs have a similar 5-HT effect underlying the therapeutic efficiency. We evaluated in a randomized, double-blind and cross-over study, the effects of a DA agonist (bromocriptine) and a DA antagonist (amisulpride) on platelet 5-HT in infantile autism. The prolactinemia, reflecting the DA action, has been also measured. Nine children, aged from 4 to 13 years, according to the DSM III for infantile autism, received either drug in a random order during four weeks with an in-between placebo period of six weeks. The dosages of platelet 5-HT and serum prolactin were carried out at the beginning and at the end of every phase of treatment (active or placebo) with radioenzymology and radioimmunoassay methods respectively. The principal results on serum prolactin show neither order x treatment interaction, nor order effect but a significant treatment effect (p < 0.01): amisulpride increases serum prolactin whereas bromocriptine decreases according to the usual data. About platelet 5-HT, there is neither order x treatment interaction, nor treatment effect but a significant order effect (p < 0.01). Both drugs increase platelet 5-HT in the first phase of treatment. This order effect could be explained by a remanent effect of amisulpride after 6 wash-out weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

[Blood platelets: neuronal model in psychiatric disorders].

There are some evidences to propose blood platelets as a model of bioaminergic neurons. Similarities between platelets and neurons are particularly important with respect to serotonin metabolism but now it is possible to extend this model to other neurotransmitters such as dopamine, GABA, glutamate... The reason for these similarities may be due to the common embryonic origin of these two very different cell types. Some changes of platelet functions are observed in psychiatric syndromes. For example: serotonin uptake, bioamine storage, enzymatic activities are modified in different types of depression and schizophrenia, infantile autism, neurologic diseases (migraine, chorea, Down syndrom). Furthermore, psychotropic drugs also alter the platelet functions. Recently, the discovery of neuro-endocrine disorders in psychiatric diseases has led to the proposal of platelets as a model in neuro-endocrinology. Some arguments can be developed to support this hypothesis. In biological psychiatry, the platelet model seems actually useful essentially in the classification of psychiatric diseases, the management of treatments and the study of new psychotropic drugs. However methodologic difficulties still presently limit the development of this model.

Autistic Disorder↗
PubMedDate not supplied

[Platelet release of dopamine in the common migraine attack].

Several arguments suggest that dopamine (DA) plays a role in the physiopathology of migraine. Conjugated and unconjugated plasma and platelet DA, as well as platelet phenolsulfotransferase M activity (responsible for DA sulfatation) were measured in 30 control subjects, 27 common migraine patients between attacks and 9 migraineurs during an attack. No modification of any of the parameters tested was detected in attack-free periods. During the attack no change of conjugated DA was observed; in contrast, a significant decrease of unconjugated platelet DA and a significant and correlated increase of plasma unconjugated DA were demonstrated. This corresponds to a release of unconjugated DA by the very dense bodies in platelets of migraine patients during the attack.

Adolescent↗
PubMedDate not supplied

Stimulation of alpha-(methylamino) isobutyric acid uptake by interleukin-1 in human synovial cells. Involvement of a cAMP dependent pathway.

After one hour incubation with interleukin-1 beta (IL-1 beta), the uptake of alpha-(methylamino) isobutyric acid (MeAIB) by human osteoarthritic synovial cells appeared significantly increased. This effect, observed with 0.1 to 5 ng/ml of cytokine, was inhibited by cycloheximide, indicating that protein synthesis is involved. In addition, this effect seems mediated by a pertussis toxin-sensitive G protein. Finally, intracellular cAMP concentration measurements, the use of a phorbol ester, protein kinase inhibitors and forskolin+3-isobutyl-1-methylxantine (IBMX) provided evidence that a cAMP-dependent protein kinase is associated with interleukin-1 beta-mediated alpha-(methylamino) isobutyric acid uptake.

Biological Transport, Active↗