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Biomedical subjects

D E Clayton

Publications and source records attributed to D E Clayton.

9 recordsLinked to original sources
PubMed1981

Contribution of vascular smooth muscle to contractile responses of guinea-pig isolated lung parenchymal strips.

Parenchymal strips, isolated from the guinea-pig lung, were stimulated transmurally at different electrical frequencies in vitro. Frequency-response analyses for contraction were obtained on paired strips in the absence or presence of antagonists. Tetrodotoxin was shown to block the effects of electrical stimulation, demonstrating that the contractile response was due to activation of efferent neurons in the tissue. Phentolamine, 10(-5) M, and atropine, 10(-6) M, antagonists demonstrated to be selective for blocking alpha-adrenergic and muscarinic receptors, respectively, produced inhibition of the contractile effects of electrical stimulation. When analyzed at the level of the frequency required to produce a contraction equal to 10% of the maximum produced by histamine, the EF10, the frequency-response curves were shifted 3- to 4-fold to the right by each receptor antagonist. Combination of the two receptor antagonists produced a greater degree of blockade than either alone and, at the maximum frequency utilized (32 Hz), the contractile response did not reach the EF10 in al tissues. Propranolol, 10(-6) M, did not alter the effects of electrical stimulation, but increased the magnitude of contraction produced by exogenously applied norepinephrine. In tissues taken from reserpine-pretreated animals, phentolamine did not produce a statistically significant change in EF10 for electrical stimulation. The data provide evidence that both vascular and airway smooth muscles are present and contribute to contractile responses in the guinea-pig lung parenchymal strip.

Animals↗
PubMed1981

Short-term efficacy trial and twenty-four-month follow-up of flunisolide nasal spray in the treatment of perennial rhinitis.

Seventy-eight patients with perennial rhinitis underwent a double-blind, placebo-controlled. 12-wk trial with flunisolide nasal spray, a new potent topical steroid. Eighteen of these patients were followed in an open study and evaluated at intervals for side effects and dosage of spray used. Baseline and plasma cortisol concentrations were performed before and at the end of the 12-wk, double-blind period. Adrenocorticotropic hormone (ACTH) stimulation testing was performed on six patients after 1 yr of flunisolide therapy at 300 micrograms/day or less. Flunisolide was found to be safe and effective over a short period. Over a 2-yr follow-up there were no serious side effects or evidence of adrenal suppression. Ten patients with perennial rhinitis continue to obtain subjective benefit after 2 yr of therapy with flunisolide nasal spray.

Administration, Intranasal↗
PubMed1981

Development of allergic bronchopulmonary aspergillosis during treatment of severe asthma with systemic corticosteroids.

Rapid clinical improvement of allergic bronchopulmonary aspergillosis (ABPA) is usually noted with corticosteroid therapy. We report a case of ABPA that developed in patient who was being treated with prednisone on a maintenance basis for severe asthma. Recovery from the short-term episode of ABPA was protracted and required higher doses of corticosteroids for control of the syndrome than usually necessary. It is suggested that corticosteroids do not prevent the development of ABPA, and that patients who develop the syndrome while on corticosteroids may have a protracted course with poor response to the usually effective doses of corticosteroids.

Adrenal Cortex Hormones↗
PubMed1981

Parainfluenza 3 infection blocks the ability of a beta adrenergic receptor agonist to inhibit antigen-induced contraction of guinea pig isolated airway smooth muscle.

Guinea pigs, actively sensitized to ovalbumin, were inoculated by nasal insufflation with parainfluenza 3 or virus growth medium 4 d before performing in vitro pharmacological studies on tracheal and bronchial smooth muscle. In each airway segment, cumulative dose-response effects of ovalbumin were obtained in the absence and presence of a maximally effective concentration of a beta adrenergic receptor agonist, sulfonterol. Sulfonterol shifted the dose-response curve to the right and reduced the maximum smooth muscle contractile response to ovalbumin. Virus infection did not alter the dose-response effects of ovalbumin. However, the magnitude of the inhibitory effects of sulfonterol was smaller in segments taken from animals inoculated with virus. Blockade by virus infection of the inhibitory effect of sulfonterol was reversed when the concentrations of beta agonist were increased. Sulfonterol did not alter the dose-response effects of histamine at any of the concentrations that markedly antagonized the effects of ovalbumin. Virus infection did not alter the sensitivities to sulfonterol or papaverine in producing relaxation in either airway segment. The magnitude of relaxation produced by papaverine was significantly larger in bronchial rings taken from animals infected with virus for 4 d, but there was no alteration by virus of the dose-response effects of histamine or carbachol. In experiments measuring antigen-induced release of slow reacting substance of anaphylaxis and histamine from minced lung, virus infection did not alter the sensitivity or the maximum effects of ovalbumin. Also, the ability of sulfonterol to inhibit the release of slow reacting substance of anaphylaxis and histamine was not affected by virus infection.These results demonstrate that infection of guinea pigs with respiratory virus results in a selective blockade of the beta adrenergic-mediated inhibition of antigen-induced contraction of airway smooth muscle. The guinea pig may serve as a useful model in physiological studies of virus-induced asthma.

Adrenergic beta-Agonists↗
PubMed1980

Anaphylaxis to wine.

Anaphylaxis following the ingestion of wine was found in a non-atopic woman. The reaction occurred within 15 min of wine ingestion but did not follow other alcoholic beverages. An immediate skin test response to the offending wine was found but specific IgE levels could not be measured by radioallergosorbent testing.

Adult↗
PubMedDate not supplied

Fatal and near fatal idiopathic anaphylaxis.

OBJECTIVE: To document that idiopathic anaphylaxis may have a fatal or near fatal outcome. DESIGN: Review of selected cases seen personally by authors during the past 16 years. SETTING: University faculty practice and private practices. PATIENTS: All cases of idiopathic anaphylaxis seen by the authors are not presented, but 10 cases were selected to demonstrate two fatalities and eight cases of near fatalities. RESULTS: Two fatal cases had expired before emergency service therapy. Eight near fatal cases responded to acute therapy and subsequently were controlled. Remission of idiopathic anaphylaxis was then induced. Idiopathic anaphylaxis may be fatal or potentially fatal and must be treated to prevent a fatal outcome. CONCLUSIONS: The documentation of fatalities and near fatalities should help patients and their physicians accept intense management of idiopathic anaphylaxis that will result in control and induction of a remission in idiopathic anaphylaxis.

Adolescent↗