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J Lépine

Publications and source records attributed to J Lépine.

15 recordsLinked to original sources
PubMed1981

Parallel stimulation of ACTH, beta-LPH + beta-endorphin and alpha-MSH release by alpha-adrenergic agents in rat anterior pituitary cells in culture.

Characteristics of the alpha-adrenergic stimulation of ACTH, beta-endorphin + beta-LPH and alpha-MSH release were studied in rat anterior pituitary cells in primary culture. Parallel changes of ACTH, beta-endorphin + beta-LPH and alpha-MSh release were found under all stimulatory and inhibitory conditions by natural and synthetic catecholamine agonists and antagonists. (-)Epinephrine and (-)norepinephrine lead to a 8--10-fold stimulation of peptide release at ED50 values of 20 and 90 nM, respectively. The stereoselectivity of the alpha-adrenergic stimulatory action on peptide release is indicated by a 100-fold higher activity of (-)- than (+)norepinephrine while (-)epinephrine is 10 times more potent than the corresponding (+) stereoisomer. The involvement of a typical alpha-adrenergic mechanism in the control of release of ACTH, beta-endorphin and related peptides in rat anterior pituitary gland is indicated by the following order of potency of a series of catecholaminergic agents (ED50 values): (-)epinephrine (20 nM) greater than (-)norepinephrine (90 nm) greater than phenylephrine (400 nM) greater than isoproterenol (6000 nM). The stimulatory effect of (-)epinephrine or phenylephrine is completely reversed by low concentrations of the alpha-adrenergic antagonist phentolamine while the beta-adrenergic antagonist propranolol has no effect up to 10 muM. Beside providing an easily accessible pure population of post-synaptic alpha-adrenergic receptors having potential applications as a model for other less accessible alpha-adrenergic brain systems, the present data suggest the possibility of the direct involvement of a catecholamine in the physiological control of ACTH secretion in the rat anterior pituitary gland.

Adrenergic alpha-Agonists↗
PubMed1981

[Post-fracture osteitis of the mandible and gentamicin acrylic cement pellets (author's transl)].

The authors propose a method for osteosynthesis of mandibular fractures in a stable and even solid manner, to avoid the inconveniences of mandibulomaxillary fixation. These include: -- the duration of the operative period, -- the necessary close supervision to avoid secondary displacement, -- desmodontous lesions, -- the adverse effects on mouth hygiene, -- the nutritional disturbances with subsequent loss of weight. There is also the ever-present risk of infection, particularly in the dentulous zone where a fracture line crossing a dental alveolus is permanently exposed to the risk of infection from the buccal flora. Three cases are described in which gentamicin acrylic cement pellets were employed to treat bone infections after osteosynthesis of mandibular fractures, with subsequent healing of the septic foci.

Acrylates↗
PubMed1980

[A comparison of anaesthetic awakening with out-patients treated by maxillo-facial surgery using 4 different anaesthetic techniques (author's transl)].

To estimate and compare the awakening period following 4 different anaesthetic techniques (enflurane and halothane and two intraveinous anaesthetic substances: propanidide and althesin), the authors examined 120 outpatients who had undergone maxillo-facial surgery distributed over 4 sample groups of 30 each. A statistical analysis of the responses to psycho-dianostic tests has not enabled the authors to decide which anaesthetic ambulatory technique is preferable.

Adolescent↗
PubMed1979

Parallel release of ACTH, beta-endorphin, alpha-MSH and beta-MSH-like immunoreactivities in rat anterior pituitary cells in culture.

Specific radioimmunoassays (RIAs) for ACTH, beta-endorphin, alpha-MSH and beta-MSH were used to identify the immunoreactive components released during incubation of rat anterior pituitary cells in primary culture. Such measurements were performed after separation of the incubation media by chromatography on Sephadex G-50 or G-75. The ACTH-RIA measured approximately equal amounts of 13 and 4.5K ACTH while equal proportions of components migrating at the position of beta-LPH and beta-endorphin were measured in the beta-endorphin RIA system. Immunoreactive components migrating at the position of gamma-LPH and alpha-MSH were measured in the beta-MSH and alpha-MSH RIA systems, resp. 3 purified corticotropin-releasing fractions (CRF) prepared from porcine hypothalami and increasing concentrations of N6,O2'-dibutyryl cyclic AMP and theophylline led to parallel release of ACTH, beta-endorphin, beta-MSH and alpha-MSH immunoreactivities while preincubation with dexamethasone led to a 30-60% inhibition of the release of all peptides. The present data show that the release of ACTH, beta-LPH, beta-endorphin, gamma-LPH and alpha-MSH-like immunoeactivities occurs in parallel in anterior pituitary cells in culture both under basal and acute stimulatory or inhibitory conditions of release.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

[8;21 translocation and leukemia].

The authors report their observations on acute myeloid leukemias associated with the 8;21 translocation. Two cases have less than the required percentage of blasts for the cytological diagnosis of acute myeloid leukemia. In one case, the 8;21 translocation is superimposed on a constitutional trisomy 21. Conclusions from the 4th International Workshop on chromosomes in leukemia are highlighted, as well as certain new data relative to the biology of acute myeloid leukemias.

Adult↗