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Biomedical subjects

D Desjardins

Publications and source records attributed to D Desjardins.

24 records · Page 2Linked to original sources
PubMed1985

Muscarinic cholinergic receptors in mouse pituitary tumor cells: prolonged agonist pretreatment decreases receptor content and increases forskolin- and hormone-stimulated cyclic AMP synthesis and adrenocorticotropin secretion.

Muscarinic receptor activation on the AtT-20 clonal line of mouse pituitary corticotrophs, inhibits forskolin-stimulated cyclic AMP formation and adrenocorticotropin secretion. In this study, the effect of prolonged receptor stimulation with the muscarinic agonist oxotremorine was found to reduce, in a time-dependent manner, the ability of oxotremorine to inhibit the AtT-20 cell response to forskolin. Pretreatment with oxotremorine also reduced the density of muscarinic receptors without affecting the affinity of these sites for [3H]quinuclidinyl benzilate. In addition to desensitizing the muscarinic receptor, oxotremorine pretreatment also enhanced the ability of forskolin to stimulate cyclic AMP formation and adrenocorticotropin secretion. The apparent sensitizing effect on cyclic AMP synthesis, extended to other muscarinic agents as well as other secretory agonists, was dependent on the oxotremorine concentration used during pretreatment and required at least 2 hr of pretreatment. Enhancement of forskolin-stimulated cyclic AMP accumulation by oxotremorine pretreatment was blocked by cycloheximide and reversed by the muscarinic antagonist, (-)-scopolamine, or by a 5-hr recovery period after pretreatment. The data suggest that prolonged muscarinic receptor activation (rather than simple occupancy) leads to an enhancement of adenylate cyclase activity in AtT-20 cells; whether this effect is coupled to the progressive loss of the inhibitory function of the muscarinic receptor and the receptor down-regulation is unknown.

Adrenocorticotropic Hormone↗
PubMed1982

Rotator cuff tears: the role of surgery.

The indications for operative intervention in patients with rotator cuff tears and the reasonable expectations of such surgery are not well defined. This retrospective study of 37 such patients treated operatively at Ottawa General Hospital showed good results in 65% of cases. However, efforts to re-establish continuity of the cuff did not always result in a permanent cuff reconstruction. The persisting defect did not impede functional recovery as long as the edges of the tear were debrided along with division of the coracoacromial ligament, acromioplasty, or excision of osteophytes at the greater tuberosity. Impingement plays a major role in the disability associated with this condition.

Adult↗
PubMed1981

Stimulus-secretion coupling in exocrine pancreas; possible role of calmodulin.

Many calcium-mediated effects in mammalian cells may be activated by calcium-calmodulin stimulated enzymes. These effects are inhibited by various antidepressant drugs which bind to and inactivate calmodulin. In the current study, calmodulin was identified by affinity chromatography and gel electrophoresis in the cytoplasm of dispersed rat pancreatic acinar cells. Its role in enzyme secretion was assessed by evaluating the effects of various antidepressants drugs on the enzyme secretory process. Chlorpromazine, trifluoperazine, thioridazine, chlorprothixene and amitriptyline inhibited amylase secretion stimulated by carbachol, A-23187, and cholecystokinin-pancreozymin but not that elicited by dibutyryl cyclic AMP secretin or vasoactive intestinal peptide (VIP). Haloperidol, sulpiride, phenobarbital, and ethanol were without effect on secretagogue-stimulated enzyme release. Only those agents which blocked secretion also inhibited 45Ca release stimulated by carbachol from isotope preloaded cells. The data suggest that calmodulin may have a functional role in pancreatic enzyme secretion.

Amylases↗
PubMedDate not supplied

[Socio-demographic and soci-professional profile of holistic therapists in Quebec].

A descriptive study of practitioners of holistic therapies in Quebec was done using a questionnaire mailed to the 954 therapists advertising publicly their services. The response rate was 37.9%. This paper presents the sociodemographic and socio-professional data collected. According to the findings, holistic therapists can be found in almost all regions of Quebec with higher concentrations in large urban centers. Their group is almost equally composed of men (51.7%) and women (48.0%) with an age mean of 40.1 years and with a mean of 7 years of experience in their practice. The practice of holistic therapies is the main occupation of most of these practitioners who use a very wide variety of therapies. Acupuncture and its derivatives followed by various types of massotherapies and naturopathy are the most commonly advertised therapies. The great majority of these therapists work in private practice and their average income before deductions was $21,856.38. Due to the legal status of these practices, 10.3% of the respondents declared they had been the object of lawsuits on the part of a professional corporation.

Adult↗