[Allergies in orthodontics]. / Les allergies en orthodontie.

In contrast with work-related allergies amongst dentists and dental prosthetictists, allergies in patients followed in orthodontics concerning the materials placed in the mouth were rare. It may be a question of limited manifestations in the buccal cavity (urticaria, angio-oedema, stomatitis, chellitis), or more generalised manifestations (Quincke's oedema, eczema). The number of materials used in orthodontics is limited. The observations concerning metals are less numerous whilst those that concern the resins are exceptional. On the other hand, the risk linked to latex is very real. Allergy investigations require skin tests, sometimes to mucous tests and in some cases to provocation tests. Use of eviction measures may be not only the only diagnostic method but also a therapeutic method. Systematic search for an allergy to metal or a resin posed by the prosthetic material does not seem to be necessary. In the case of suspicion of latex, confirmed ultimately by an allergic history, this imposes start of the eviction measures.

Substance P induces a cardiovascular defense reaction in the rat: pharmacological characterization.

In this study in conscious rats, we tested the hypothesis that substance P, a central pressor peptide and a potential transmitter substance of pain pathways, could be involved in the cardiovascular defense reaction that is typically associated with unpleasant sensory stimuli. The hemodynamic responses to centrally administered substance P were pharmacologically characterized. The increases in blood pressure and heart rate after intracerebroventricular injections of substance P were accompanied by mesenteric and renal vasoconstriction and hind limb vasodilation (pulsed-Doppler flow probes). The pressor and vasoconstrictor responses were attenuated by peripheral alpha 1-adrenoceptor blockade with prazosin but were not influenced by blockade of vascular vasopressin receptors with d(CH2)5Tyr(Me) arginine vasopressin (AVP). Cardiac beta 1-adrenoceptor blockade with metoprolol abolished the tachycardic and reduced the pressor responses. Substance P-induced hind limb vasodilation was not sensitive to intravenous atropine but was largely prevented by peripheral beta 2-adrenoceptor blockade with ICI 118,551. Thus, the substance P-induced pressor effects are mediated by alpha 1-adrenergic sympathetic vasoconstriction and beta 1-adrenergic cardiac stimulation, whereas the hind limb vasodilation is mainly due to beta 2-adrenergic stimulation. Substance P dose-dependently (0.01-10 micrograms i.c.v.) released oxytocin but not vasopressin or adrenocorticotropic hormone (ACTH) from the pituitary gland. High doses reduced basal ACTH levels. Together with the hemodynamic responses, a behavioral arousal reaction was observed, which included increased locomotion, grooming, scratching, and skin biting. Our results demonstrate that a neuropeptide can induce classic cardiovascular defense reaction.(ABSTRACT TRUNCATED AT 250 WORDS)