Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0010200 (cough)
 23,843 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of inhaled capsaicin, the irritant extract of pepper, on airway tone has been studied in humans. Inhaled capsaicin (2.4 X 10(-10) and 2.4 X 10(-9) mol) caused a dose-dependent fall in specific airways conductance (maximum fall 28 +/- 19 and 38 +/- 19%, respectively; means +/- SD, n = 17). This was maximal within 20 s of exposure and lasted for less than 60 s. There was no difference in the magnitude or duration of bronchoconstriction between normal, smoking, or asthmatic subjects. Capsaicin also caused coughing and retrosternal discomfort. On repeated exposure to capsaicin, there was no evidence for a reduced response (tachyphylaxis). Ipratropium bromide (0.25 mg by inhalation) significantly (P less than 0.05) reduced the bronchoconstriction (maximum falls 34 +/- 14 and 15 +/- 9% after saline and ipratropium bromide, respectively; means +/- SD n = 6), indicating that it was dependent on a cholinergic vagal reflex rather than on local release of substance P from nerves in the airway. Inhaled sodium cromoglycate (10 mg by nebulizer or 40 mg as a dry powder), however, had no significant effect on the bronchoconstrictor response. Capsaicin may be a useful tool for investigating nonmyelinated nerve reflexes in human airways.
 ...
PMID:Bronchoconstrictor response to inhaled capsaicin in humans. 315 68

Experimental and clinical experience with compounds containing antimony have shown that the trivalent compounds are generally more toxic than the pentavalent ones. APT can cause severe pain and tissue necrosis and is therefore not given by intramuscular or subcutaneous injection. APT has the actions and uses of AST, but it is less soluble and more irritating than the sodium salt which is therefore more suitable for intravenous use. Trivalent antimony compounds are toxic when used topically. Adverse effects are similar for all trivalent compounds, and include nausea, vomiting, weakness and myalgia, abdominal colic, diarrhoea, and skin rashes, including pustular eruptions. Hypersensitivity reactions also occur. Respiratory symptoms include cough, dyspnoea, and chronic lung changes. Cardiotoxicity is the most important and may produce arrhythmias, myocardial depression and damage, Stokes-Adams attacks, heart failure, and cardiac arrest. Hepatic damage and necrosis, as well as blood dyscrasias, may occur. Toxic effects on the kidney may follow chronic use. Continuous treatment with small doses of antimony may give rise to symptoms of subacute poisoning, similar to those of chronic arsenic poisoning, due to accumulation of antimony in the body, especially if trivalent compounds are used, because of their long biological half-lives. Reproductive disorders and chromosome damage have been reported; antimony compounds are, therefore, potentially toxic to reproduction and have mutagenic, and oncogenic potential. Antimony compounds should, therefore, not be used during pregnancy or in the presence of hepatic, renal, or heart disease. Pentavalent antimony preparations especially the organic compounds, together with non-metallic synthetic preparations, such as the diamidines, have now replaced APT for use in leishmaniasis. Because of the toxicity of antimony compounds, investigations have been undertaken to reduce their adverse effects by combining them with chelating agents. These preparations appear to have reduced the toxic effects of antimony without affecting the efficacy of the preparations. Liposome-encapsulated antimony products have, more recently, been shown to be much less toxic because of the reduced dose of the antimony compound required for effective therapy. The historical uses of antimony were based on the belief that the topical and systemic adverse effects, for example, skin eruptions and diarrhoea and vomiting, were signs that the condition being treated was responding by being brought to the surface to relieve congestion at the diseased area. There is no evidence in topical use, but there is evidence that such use can cause severe reactions.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Toxicity of antimony and its compounds. 330 36

1. The chemosensitivity of cough receptors stimulated by inhalation of aqueous aerosols was evaluated in 21 normal volunteers in three experiments. 2. The pH of isotonic saline was altered using small amounts of phosphate or glycine buffers to produce solutions with a pH range of 2.6-10.0. These solutions were nebulized ultrasonically and breathed for 1 min periods by seven subjects in random order and on separate days. Cough frequency during each 1 min inhalation was recorded. Only the two solutions of extreme pH (2.6 and 10.0) caused cough. 3. The effect of altering the osmolarity of the inhaled aerosol on cough was assessed using D-glucose over a range of 77-1232 mosmol/l. Saline solutions over the same range of osmolarity were also tested. The pH of D-glucose was raised to match that of saline by adding small amounts of sodium hydroxide. All solutions were nebulized and inhaled by seven subjects as described above for 1 min periods during which cough frequency was recorded. Forced expired volume in 1 s was recorded after each inhalation and did not alter in any subject by more than 10%. Subjects coughed when inhaling all the D-glucose solutions over the whole range of osmolarity. Cough occurred with saline solutions only at low chloride concentration and at the highest concentration. 4. In order to clarify whether the response to hypertonic saline was due to the high ionic content of the solutions or to its hypertonicity, two other solutions were tested. These were an isotonic and a hypertonic mixture of D-glucose and saline, containing 'normal' (150 mmol/l) ionic content.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Effects of pH and osmolarity on aerosol-induced cough in normal volunteers. 335 9

Airborne Ptychodiscus brevis toxin (PBTX), produced by Ptychodiscus brevis (Florida red tide), induces cough, rhinorrhea, watery eyes, and sneezing in normal individuals and wheezing in subjects with asthma. The mechanism of PBTX-induced contractile response has been investigated by the authors in vitro in dog and rat tissue. PBTX stimulates neuronal sodium channels, resulting in activation of autonomic cholinergic and adrenergic nerve endings in canine upper and lower airway smooth muscle and in rat vas deferens, respectively. This article concerns the investigation of the effect and mechanism of action of PBTX on human airways in order to determine the unique role of the toxin in the pathogenesis of asthma. PBTX elicited contractions of isolated human airway smooth muscle with a threshold concentration of 0.1 micrograms/ml, very similar to values obtained in canine lower airways. Pharmacologic analysis demonstrated that atropine (10(-6) mol/L) blocked the response to both PBTX and acetylcholine; tetrodotoxin (10(-7) mol/L) blocked PBTX but not acetylcholine; and verapamil (10(-5) mol/L) attenuated but neostigmine (10(-8) mol/L) potentiated the response to PBTX. Other selected blockers did not affect the PBTX response. These data indicate that PBTX produces contraction of human lower airway smooth muscle via stimulation of cholinergic nerve fiber sodium channels. The concept that PBTX triggers asthma through this mechanism is strengthened by these results.
 ...
PMID:In vitro red tide toxin effects on human bronchial smooth muscle. 337 31

To determine the role of central serotonergic systems in modulating the cough reflex, the effects of serotonergic agonists on the respiration and the cough reflex were comparatively studied. Male and female cats were anesthetized with sodium pentobarbital. Respiration and cough reflex were measured using a pneumotachograph via a cannula inserted into the trachea. The cough reflex was elicited by electrical stimuli to the superior laryngeal nerve. Tranylcypromine, a MAO inhibitor, in a dose of 5 mg/kg, i.v., increased the respiration, but depressed the cough reflex. The serotonin precursor 5-hydroxytryptophan (5 mg/kg, i.v.) depressed the respiration and the cough reflex. Haloperidol (2 mg/kg, i.v.) abolished the tranylcypromine-stimulated respiratory responses, and it intensified the tranylcypromine induced cough depression. It is concluded that the increase in serotonin levels in the brain has a depressant influence on the central generating mechanisms of the cough reflex. Furthermore, central dopaminergic mechanisms seem to play a modulating role on the cough reflex.
 ...
PMID:Involvement of central serotonergic mechanisms in the cough reflex. 349 20

The relationships between mucus rheology, depth of mucus layer and clearance by simulated cough were examined in a study employing a model plexiglass trachea lined with gels formed from locust bean gum crosslinked with sodium tetraborate. The viscoelastic properties of the mucus simulants were determined by magnetic rheometry at 100 rad/s and expressed as mechanical impedance (dynamic stress/strain ratio) and loss tangent. Cough was simulated by opening a solenoid valve connecting the model trachea to a pressurized tank, using an upstream flow-constrictive element to shape the flow profile to approximate the pattern seen in a normal adult. Mucus clearance was quantitated by observing the movement of contrasting marker particles placed in the mucus layer. The median particle displacement was defined as the clearance index, Cl. For any initial depth of mucus, Cl increased with driving pressure in the tank, and for a given driving pressure, Cl increased linearly with increasing mucus depth. For a given driving pressure and depth, Cl decreased with increasing mechanical impedance of the mucus. At constant mechanical impedance, Cl increased with increasing loss tangent, in other words, cough clearance was impeded more by elasticity than viscosity. Mucus clearance was associated with transient wave formation in the lining layer. Thus dependence on viscoelasticity is consistent with observations that airflow-mucus interaction and wave formation are impeded by elasticity. The clearance vs. loss tangent relationship for cough is opposite to that found for ciliary clearance (Biorheology 1980, 17, 249), suggesting a natural balance in viscosity and elasticity for mucus to be cleared by both mechanisms.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:The role of mucus viscoelasticity in cough clearance. 350 60

The effect of bradykinin was studied by inhalation in normal and asthmatic human subjects, as well as on human bronchial smooth muscle in vitro. Bradykinin caused cough and retrosternal discomfort in all subjects and bronchoconstriction in asthmatic subjects. Bradykinin was approximately 10 times more potent than histamine and methacholine, and there was a significant correlation between the subjects' sensitivity to histamine and bradykinin. Bradykinin-induced bronchoconstriction was prolonged when compared with that of histamine and the C-fiber stimulant capsaicin. This bronchoconstriction was subject to tachyphylaxis, which was also associated with desensitization of the subjects to inhaled histamine. The provocative dose causing a 35% fall in specific airway conductance (PD35) was unaffected by aspirin (1 g orally). However, ipratropium bromide (0.25 mg by nebulizer) significantly inhibited the effect of bradykinin, the PD35 being 0.8 mumol (range, 0.16 to 3.4) and 0.15 mumol (range, 0.047 to 1.15) after active dose and placebo, respectively (p less than 0.05). Likewise, cromolyn sodium (40 mg dry powder) also significantly reduced response to bradykinin, with a PD35 of 0.04 mumol (range, 0.13 to 0.31) after placebo and 0.39 mumol (range, 0.05 to 4.45) after SCG (p less than 0.05). Bradykinin only weakly constricted human bronchial smooth muscle in vitro. Bradykinin at 10(-4) caused only 21.5 +/- 5.5% of the maximal carbamylcholine contraction in 11 of 18 airways. Captopril did not enhance the effect of bradykinin. Bradykinin is a potent bronchoconstrictor of human airways in vivo, acting in part through cholinergic mechanisms but not because of the formation of prostaglandins.
 ...
PMID:Bradykinin-induced bronchoconstriction in humans. Mode of action. 354 15

Twenty-five patients were observed in a prospective crossover study to determine whether the new low-osmolality contrast agents would be less prone than conventional agents to produce coughing during pulmonary arteriography. Selective left and right pulmonary arteriography (two views of each side) was performed with alternating administrations of diatrizoate sodium meglumine and ioxaglate sodium meglumine. Twenty-one patients had all four injections while four patients received injections on only one side. Sixteen of 25 patients coughed on at least one injection of diatrizoate, with three of these experiencing explosive coughing. One of 25 patients coughed with ioxaglate, and that was only minimally. This difference is statistically significant (P less than .001, on the basis of McNemar chi 2 test for paired data). When no coughing occurred, the quality of the diatrizoate and ioxaglate radiographs was indistinguishable. We conclude that ioxaglate is useful in pulmonary arteriography because of its lack of cough stimulation.
 ...
PMID:Pulmonary arteriography: comparison of cough stimulation effects of diatrizoate and ioxaglate. 354 28

Predictors of dyspnea were studied during induced airflow obstruction or cough in an attempt to increase understanding of factors related to observed variability in the descriptions of the experience of dyspnea. Thirty-one adult subjects with asthma participated in a 2-day protocol using a laboratory analog of asthma. Air flow obstruction and dyspnea were induced on Day 1 with inhalations of methacholine in doubling concentrations from 0.063 to 2.0 mg/ml. Cough was induced on Day 2 with inhalations of 3% sodium gluconate solution. Dyspnea was assessed on both days by a visual analog technique. The magnitude of dyspnea was not related to airway caliber. There was a significant negative relationship between age and magnitude of dyspnea and between cigarette pack years and dyspnea intensity. Dyspnea at baseline was positively related to dyspnea intensity during induced bronchoconstriction. Dyspnea during cough was not related to airway caliber, but there was a significant difference between males and females in the intensity of dyspnea at cough threshold. These findings may explain some of the variability observed in the experience of dyspnea in asthma.
 ...
PMID:Predictors of dyspnea intensity in asthma. 364 19

We describe a patient who had consumed large quantities of a proprietary cough mixture containing diphenhydramine, ammonium chloride and sodium citrate (Benylin expectorant) daily for several months and subsequently presented with confusion, marked metabolic acidosis and non-ketotic hyperglycaemia.
 ...
PMID:Benylin dependence, metabolic acidosis and hyperglycaemia. 365 71


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>