PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Methacholine Compounds”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 901 records · Page 50Linked to original sources
PubMed1980

Plasma cyclic nucleotide responses to insulin-induced hypoglycaemia and methacholine in patients with hyperthyroidism.

The effect of insulin-induced hypoglycaemia and methacholine on plasma cAMP and cGMP levels was studied in normal volunteers, hyperthyroid and hypothyroid patients. A significant positive correlation existed between the maximal increase in plasma cAMP and the maximal decrease in plasma glucose in normals during insulin-induced hypoglycaemia. Therefore, the plasma cAMP response is considered to be dependent on the degree of hypoglycaemia, rather than the dose of insulin. The cAMP response to hypoglycaemia was significantly higher in hyperthyroid patient, and was lower in patients with hypothyroidism than in normals. The cAMP response of the hyperthyroid patients was normalized when their hyperthyroidism was controlled after 3 months of treatment. The plasma level of cGMP was slightly elevated during hypoglycaemia, but there was no significant difference between controls and hyperthyroid patients. The cGMP response to methacholine, which is probably mediated by cholinergic receptors, was significantly potentiated in hyperthyroid patients. The cAMP response, which is presumably dependent on endogenous catecholamines secreted during methacholine-induced hypotension, was also enhanced in hyperthyroid patients. It is likely that beta-adrenergic receptor responses and cholinergic receptor responses are both enhanced in hyperthyroidism.

Adolescent↗
PubMed1979

Methacholine and histamine inhalation challenges in asthma: relationships to age of onset, length of illness, and pulmonary functions.

Levels of airways hyperreactivity, as indexed by methacholine and histamine thresholds, were determined for hospitalized asthmatic patients using the serial concentration, constant-breath method. Airways hyperreactivity was categorized into low and high based on a split of the sample of subjects tested. These categories were unrelated to pulmonary function measurements obtained throughout hospitalization. Patients having high airways hyperreactivity to histamine or methacholine were admitted for intensive inpatient care at a young age, had an earlier age of onset, and had asthma of longer duration than patients having low airways hyperreactivity. These latter results suggested that relatively greater airways hyperreacticity is more likely to be associated with early onset of the illness.

Adolescent↗
PubMed1981

Reduction of metacholine-induced nasal secretion by treatment with a new topical steroid in perennial non-allergic rhinitis.

The value of three objective tests of the nasal mucosa in 22 patients with perennial non-allergic rhinitis treated with a topical corticosteroid has been investigated. Placebo and three different dosages of a new steroid, budesonide, were administered intranasally using a double-blind, cross-over technique. Nasal airway resistance was not reduced by the steroid treatment as compared with the placebo treatment. Eosinophilia in nasal smears was reduced by budesonide. However, the value of this test was decreased by the fact that eosinophilia was found in less than 50% of the patients at the beginning of the trial. Metacholine-induced nasal secretion was significantly reduced by the budesonide treatment. Symptom scores for nasal obstruction, secretion and sneezing attacks were also significantly reduced by the steroid.

Administration, Intranasal↗
PubMed1981

Antigen-induced bronchial anaphylaxis in actively sensitized SD rats. Effects of immunization and provocation doses of antigen and of pretreatment with DSCG, theophylline, terbutaline and a new anti-allergic xanthine derivative, D4026.

Bronchial anaphylactic reactions, estimated as increase in intratracheal pressure, were precipitated by intravenous injections of antigen into actively sensitized SD rats. The degree of bronchial reactivity was found to depend on both the challenge dose and the immunization dose of antigen; therefore the course of the capacity to respond was recorded as a function of these variables. The degree of the bronchial anaphylactic response could be reduced by pretreatment with disodium cromoglycate, terbutaline or a new anti-allergic xanthine derivative, D 4026, in some groups of animals. The efficacy of each agent was found to depend on the dose of antigen used for sensitization and for provocation of the bronchial reaction rather than on the strength of the response. Taken together, the data suggest that more than one type of homocytotropic antibody mediates bronchial anaphylactic reactivity in the SD rat.

Adjuvants, Immunologic↗
PubMed1984

Ipratropium in the treatment of patients with perennial rhinitis.

Rhinorrhea is due to increased parasympathetic activity. This study was undertaken in order to study the applicability and efficacy of ipratropium, an anticholinergic drug, in patients with perennial rhinitis seen in an allergy clinic. Thirteen patients were included in the double-blind, cross-over study following screening with methacholine test. The number of paper tissues used during the period with active drug decreased significantly. Other variables did not change significantly. Eight patients preferred the active drug. The findings of this study suggest that ipratropium bromide is a valuable addition in the treatment of patients with perennial rhinitis with rhinorrhea.

Adult↗
PubMed1985

Increased bronchial hypersensitivity after early and late bronchial reactions provoked by allergen inhalation.

The non-specific bronchial reactivity following bronchial allergen challenge was studied in 40 patients with allergic bronchial asthma, particularly in subjects without definite late reactions 6 h after the provocations (reduction in peak expiratory flow or forced expiratory volume in 1 s of less than 15% of the control value at this time). Among a group of 21 patients submitted to bronchial provocation tests, 13 carried out maximal exercise tests 6 and 1 week after the allergen challenge. In another group of 19 patients, the bronchial hyperreactivity to methacholine was assessed before and 6 h and 1 week after challenge. Two patients with a dual response (early & late) reacted with bronchial obstruction to the exercise. Exercise tests performed after 1 week did not provoke asthma in any patient. In the methacholine group a marked increase in responsiveness to methacholine 6 h after the provocation was observed in those patients with a dual response who were tested and in those with equivocal late reactions and even in three patients with an isolated immediate reaction. The increases responsiveness was still present in many patients 1 week after challenge. The airway caliber did not influence the degree of responsiveness to methacholine. Nor did the degree of responsiveness have any influence on the patterns of reactions observed after allergen exposure. It was concluded that in some individuals exposure to the relevant allergen predisposes them to exercise-inducible bronchial obstruction. Further, it was confirmed that non-specific bronchial reactivity can be increased not only in patients with late responses - both definite and equivocal--but also in some patients with immediate reactions alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

Allergen-induced release of sulphidopeptide leukotrienes (SRS-A) and LTB4 in allergic rhinitis.

Leukotrienes are a recently discovered group of arachidonic acid-derived lipid mediators. Using radioimmunoassay and high pressure liquid chromatography (HPLC), we have identified the SRS-A sulphidopeptide leukotrienes (LTC4, LTD4 and LTE4) in nasal washings from patients with allergic rhinitis who underwent nasal challenge with specific allergen. Smaller, but significant, amounts of LTB4 were also detected. The concentrations of nasal leukotrienes were directly related to the dose of allergen, and were recovered in washings in a time-dependent fashion after challenge. When the patients were subjected to methacholine nasal challenge on a control day, we found only negligible amounts of either the sulphidopeptide leukotrienes or LTB4. These findings support the view that LTC4, LTD4 and LTE4 might contribute to the pathogenesis of allergic rhinitis as a result of their recognized effects on mucous hypersecretion and vasopermeability, and that the potent chemoattractant LTB4 might be involved in the subsequent infiltration of inflammatory cells.

Adult↗
PubMed1986

Ketotifen and methacholine-induced bronchospasm.

In a double-blind investigation the aspecific bronchus threshold was estimated by administration of methacholine to 16 young atopic patients with proven airways hyperreactivity (PC20 histamine less than or equal to 2 mg/ml. The influence of prolonged oral administration (12 weeks) of ketotifen (2 mg/day) on the bronchus threshold value has been studied. No significant elevation was found. It could be concluded that administration of ketotifen, even in prolonged administration, has no anticholinergic effects.

Adolescent↗
PubMed1989

Housewives with raw potato-induced bronchial asthma.

Allergy to white potato has rarely been described. We report two cases of atopic patients, housewives, in whom peeling raw potatoes precipitated rhinoconjunctivitis and asthmatic attacks, and, in one of them, contact urticaria. Type I hypersensitivity to raw potato antigens was demonstrated by means of immediate skin test reactivity, specific IgE determination by RAST, basophil degranulation, histamine release test and an immediate bronchial provocation test response to raw potato extract. The controls did not react to any of these tests. Potato allergenic constituent is currently being investigated but, as far as we know, it is heat-labile and has an MW of more than 10 Kd.

Adult↗
PubMed1990

Effect of ketanserin, a new blocking agent of the 5-HT2 receptor, on airway responsiveness in asthma.

Most of the antihypertensive drugs have a liability for adverse effects in asthma. Since there are few available data on the effect of ketanserin, a new antihypertensive drug which is a type-2 serotonin receptor antagonist, on human respiratory function, we have tested whether this drug can modify bronchial hyperresponsiveness to methacholine in asthmatic patients. The protective effect of intravenous ketanserin (0.14 mg/kg) was small, but significant.

Adult↗
PubMed1998

Determinants of bronchial responsiveness in the European Community Respiratory Health Survey in Italy: evidence of an independent role of atopy, total serum IgE levels, and asthma symptoms.

The aim of the analysis was to test whether total serum IgE levels, specific serum IgE levels, and asthma symptoms are independent predictors of bronchial hyperresponsiveness (BHR), after controlling for known risk factors or potential confounders. The study was carried out on a sample of 875 young adults, 20-44 years old, who took part in the European Community Respiratory Health Survey in Italy. The subjects underwent a dose-response methacholine challenge test. We also measured airway caliber as the baseline FEV1 in absolute terms and as percentage of forced vital capacity (FVC); skin wheal response to 11 common environmental allergens; and total and specific serum IgE levels to mites, molds, pets, and respiratory symptoms by means of a standardized questionnaire. Atopy (positive skin prick test and/or positive specific IgE assay), total IgE, asthma symptoms, airway caliber, and age appeared to be independent predictors of BHR. When all the other risk factors were taken into account, atopy and total IgE were associated with a threefold increase in BHR risk and thus emerged as the main determinants of BHR. The importance of symptom status as a determinant of BHR decreased remarkably after controlling for atopy and IgE: the odds ratio of current asthmatics to asymptomatic subjects decreased from 15.3 to 8.8. When controlling for symptoms and atopy, a family history of allergic diseases and early respiratory infections was not found to be associated with BHR. Both FEV1 and FEV1/FVC were strongly and inversely associated with BHR. When airway caliber was taken into account, older age was associated with decreased responsiveness, and the level of responsiveness did not differ significantly between males and females and between smokers and nonsmokers. The results from this analysis indicate that at any given age, irrespective of sex and smoking habits, total serum IgE, specific IgE, airway caliber, and asthma symptoms are the main independent factors influencing the occurrence of BHR in a young adult sample.

Adult↗
PubMed1998

Occupational asthma and food allergy due to carmine.

Carmine (E120), a natural red dye extracted from the dried females of the insect Dactylopius coccus var. Costa (cochineal), has been reported to cause hypersensitivity reactions. We report a case of occupational asthma and food allergy due to carmine in a worker not engaged in dye manufacturing. A 35-year-old nonatopic man, who had worked for 4 years in a spice warehouse, reported asthma and rhinoconjunctivitis for 5 months, related to carmine handling in his work. Two weeks before the visit, he reported one similar episode after the ingestion of a red-colored sweet containing carmine. Peak flow showed drops higher than 25% related to carmine exposure. Prick tests with the cochineal insect and carmine were positive, but negative to common aeroallergens, several mites, foods, and spices. The methacholine test was positive. Specific bronchial challenge test with a cochineal extract was positive with a dual pattern (20% and 24% fall in FEV1). Double-blind oral challenge with E120 was positive. The patient's sera contained specific IgE for various high-molecular-weight proteins from the cochineal extract, as shown by immunoblotting. Carmine proteins can induce IgE-mediated food allergy and occupational asthma in workers using products where its presence could be easily overlooked, as well as in dye manufacture workers.

Adult↗
PubMed1988

The effect of trifluoperazine on bronchial responsiveness in asthma.

1. The protective effects of oral trifluoperazine (TFP) (7 mg) against standardized methacholine and histamine inhalation tests (MIT and HIT) were examined 2 and 22 h post-treatment in eight stable asthmatics using a randomized double-blind protocol. 2. A preliminary study tested whether a preceding MIT influenced the result of a subsequent HIT. 3. The mean baseline forced expiratory volumes in 1 s (FEV1) were similar prior to placebo and TFP. The mean FEV1 values 2 h after ingestion of placebo or TFP were not different from the baseline values. 4. TFP did not alter bronchial responsiveness to inhaled methacholine or histamine 2 h post-ingestion, but at 22 h the PC20 methacholine was greater than placebo, while PC20 histamine did not change. This change in methacholine responsiveness was not clinically significant. 5. There was a correlation between geometric mean provocative concentration of histamine to cause 20% fall in FEV (PC20H) for HIT performed in isolation ('separate day') and for HIT performed after MIT ('same day'). 6. The effect of inhaled TFP (10 mg/ml, nebulized for 5 min) was examined single-blind and placebo-controlled in a separate group of six stable asthmatics. 7. Inhaled TFP had a bronchoconstrictor effect in all six asthmatics. The mean fall in FEV1 was 36.4% after inhaled TFP and 2.1% after saline. 8. In the asthmatics studied, ingested TFP exhibited a weak anticholinergic effect 22 h post-treatment, but a brisk spontaneously self reverting bronchoconstrictor response was invariably seen when TFP was inhaled.

Adolescent↗