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At least 253 records · Page 14Linked to original sources
PubMed1980

The oculocardiac reflex as a surgical aid in identifying a slipped or 'lost' extraocular muscle.

The oculocardiac reflex during strabismus surgery has generally been regarded as a hazard capable of causing death. Six cases are presented which show a beneficial use of the oculocardiac reflex. Isolation of a previously slipped or 'lost' extraocular muscle can be difficult. In this series identification of the tissue as muscle was substantiated by observing a positive oculocardiac reflex when traction was placed on the suspected tissue. Each of the 6 dislodged extraocular muscles was the medial rectus muscle. Three of the muscles had been resected and 3 either recessed or tenotomised. In one patient, despite 6 previous strabismus operations, including 2 strabotomies on a muscle that slipped, and in another patient, who had a lapse of 6 years since the last strabotomy, when the slipped muscle was isolated, the oculocardiac reflex could still be elicited. To avoid abolishing the oculocardiac reflex during surgery the anaesthetist should be instructed to avoid the use of an intravenous parasympatholytic agent, such as atropine, at the time of induction and during the operation.

Adult↗
PubMed1980

Atopy and bronchial reactivity in older patients with cystic fibrosis.

We studied 25 adolescent and adult patients with cystic fibrosis (CF) and 25 control subjects to determine if the prevalence of atopy and bronchial hyperreactivity was increased in this disease. Results showed that atopic symptoms, as defined by history, were more frequently present in the CF patients. Prick testing of the skin produced positive reactions in 88% of the CF group and 36% of the control subjects (p less than 0.001), and the mean number of reactions per subject was significantly higher in the former group (p less than 0.001); reactions to fungal antigens were strikingly positive in the CF group. The CF patients had a significantly higher mean serum IgG4 (p less than 0.001), IgE (p less than 0.01), and higher mean eosinophil count (p less than 0.05). Clear-cut bronchial hyperreactivity was demonstrated in the CF group compared with control subjects. Bronchial provocation with 400 micrograms of histamine led to a greater than 15% fall in the preinhalation FEV1 in 35% of the CF subjects compared with 4% of the control group, with a mean percentage fall of 15% and 3% respectively (p less than 0.001). In the CF group a greater than 15% rise in PEFR occurred in 32% after inhalation of the parasympatholytic, ipratropium bromide (54 micrograms), and in 27% after inhalation of the sympathomimetic, fenoterol (400 micrograms). No correlation was found between bronchial reactivity and atopic status, HLA phenotype pattern, or disease severity. The cause of the increased prevalence of atopy and bronchial reactivity in CF patients remains unknown. However, it is clear that a trial of bronchodilator therapy is warranted in adolescents and young adults with CF.

Adolescent↗
PubMed1981

Exercise-induced bronchoconstriction as an expression of bronchial hyperreactivity: a study of its mechanisms in children.

The mechanism of exercise-induced bronchoconstriction (EIB) was studied by observing the protective effects of several aerosol agents in a double-blind, randomised trial. Exercise-induced bronchoconstriction was not affected by placebo, but was reduced by each agent used (p less than 0.001). Blocking the parasympathetic system had the weakest effect, while beta 2 adrenergic stimulation produced the strongest effect which was significantly different from the parasympatholytic (p less than 0.02). The effect of the mast cell stabilizer, sodium cromoglycate (SCG) was found to be intermediate. However in some patients SCG had a stronger effect than the beta 2 adrenergic agonist. A relationship was found between EIB and bronchial hyperreactivity induced by histamine (p less than 0.05).

Adolescent↗
PubMedDate not supplied

Acupuncture in bronchial asthma: bodyplethysmographic measurements of acute bronchospasmolytic effects.

In 12 patients with bronchial asthma the effects of acupuncture (45 tests altogether) on airway resistance have been investigated. In 9 patients there was a significant decrease of airway resistance 10 minutes, 1 hour and 2 hours after the end of acupuncture. The lowest level for airway resistance (70.1% of control value) was reached during the first hour after acupuncture. The possibility of a merely suggestive effect could be excluded, because "placebo-acupunctures" did not change airway resistance significantly. The comparison with a parasympatholytic acting drug as a metered aerosol (Atrovent) demonstrated that acupuncture had a somewhat weaker bronchospasmolytic effect. Three patients did not show any reaction after repeated acupunctures.

Acupuncture Therapy↗
PubMedDate not supplied

Modification of cardiovascular function in dogs by acupuncture: a review.

Acupuncture at Jen Chung (Go-26) in dogs under halothane anesthesia produces sympathomimetic-like effects on the cardiovascular system. This response can be inhibited by pretreatment with propranolol and to a lesser extent with phentolamine. Severe hypotension and cardiac arrest produced by hypoxia in dogs under halothane anesthesia can be reversed by acupuncture at Jen Ying (St-9). This also was interpreted as a sympathomimetic-like effect. Acupuncture at Tsu San Li (St-36) results in a parasympathomimetic-like effect on the cardiovascular system which can be inhibited by atropine. A parasympatholytic-like effect resembling that produced by atropine can be obtained in dogs with sinus arrhythmia and pulsus alternans by acupuncture at Yang Hsi (LI-5).

Acupuncture Therapy↗
PubMed1975

Mucociliary tracheal transport rates in man.

A new method for measuring mucociliary tracheal transport rates (MTTR's) is described. An aqueous aerosol containing albumin microspheres labeled with 99mTc was inhaled in such a manner that it was deposited in local concentrations in the large airways. These boli of microspheres were transported up the trachea and their MTTR's measured using a gamma camera. MTTR's were measured in 42 healthy nonsmoking adults (32 men and 10 women, mean age 28 yr). The mean MTTR's appeared to be log normally distributed with a geometric mean of 3.6 mm/min and a coefficient of variation of 75%. The MTTR's of men and women were similar. Each individual's short-term coefficient of variation was 25%. Twenty-two repeat studies 1 wk to 15 mo apart showed the variation within individuals was less than between individuals. The parasympatholytic drug, atropine (0.6 mg iv) decreased MTTR's for at least 3 h. Inhalation of the sympathomimetic drug, Th1165a increased MTTR's. Chronic and acute smoking did not appreciably change the MTTR'S.

Adrenergic beta-Agonists↗
PubMed1978

Distribution of bronchodilatation in normal subjects: beta agonist versus atropine.

Bronchodilatation was produced in normal subjects by the inhalation of a parasympatholytic agent (atropine) and the response was compared to that occurring after the inhalation of a beta-adrenergic agent (isoetharine). Doses were chosen that resulted in equivalent increases in specific airway conductance (78 +/- 9% for atropine; 88 +/- 21% for isoetharine). Anatomic dead space and volume at the onset of the terminal nitrogen rise (closing volume) were measured before and after each agent. Although there was no difference in the degree of overall bronchodilatation after the two drugs, anatomical dead space increased significantly more after atropine than isoetharine (+17% vs. +6%, P less than 0.01), and closing volume increased significantly after isoetharine (P less than 0.005) but did not change with atropine. We interpret these differences to indicate a greater effect of cholinergic antagonists on the more central airways and a greater effect of beta-adrenergic stimulants on peripheral airways.

Adult↗
PubMed1979

Measurements of the dead space volume.

The "anatomical" dead space is commonly measured by sampling an inert gas (N2) and volume in the exhalation following a large breath of oxygen (VD(F)). It may also be measured from an inert gas washout (VD(O)) that describes both volume and the delivery of VD(O) throughout the expiration. VD(O) is known to increase with age and is enlarged in some obstructive syndromes. VD(O) was appreciably larger than VD(F) in our normal subjects. Both measures increased with lung volume, the increase being entirely due to an increase in the volume of phase I. Physiological dead space (VD(p)) however, did not change significantly with lung volume, showing "alveolar" dead space to diminish as a result. An increase in VD(O) occurred with increasing respiratory frequency that was explained by the increase in volume of phase I. Although an increase in VD(F) occurred with frequency, this was significantly less than that seen by VD(O), i.e., VD(F) did not see the progressive increase in phase I volume with frequency. No lung volume or frequency changes, parasympatholytic or sympathomimetic drugs, or altered patterns of breathing simulated the late delivery of dead space seen in age and some obstructive syndromes.

Aging↗
PubMed1990

Insensitivity of maximum expiratory flow to bronchodilation in normal dogs.

We examined the effects of the inhaled parasympatholytic agent atropine and the sympathomimetic agent salbutamol on partitioned frictional pressure (Pfr) losses to the site of flow limitation (choke point, CP) in dogs to see how changes brought about by these agents would affect maximum expiratory flow (Vmax) and response to breathing 80% He-20% O2 (delta Vmax) in terms of wave-speed theory of flow limitation. In open-chest dogs, a Pitot-static tube was advanced down the right lower lobe to locate CP, to determine CP lateral and end-on pressures (PE), and to partition the airway into peripheral (alveoli to sublobar) and central (sublobar to CP) segments. Measurements were obtained at approximately 50% vital capacity. After inhalation, CP locations were unchanged with both bronchodilating agents. After atropine inhalation, Pfr central was decreased by one-half compared with base line. Despite the decrease in Pfr central, however, Vmax failed to increase after atropine because of altered bronchial area pressure (BAP) behavior at the CP site. After salbutamol inhalation, Pfr peripheral was reduced by about one-half compared with base line. However, Vmax failed to increase, because this reduction was too small to significantly increase the CP pressure head (i.e., PE). delta Vmax was also insensitive to these agents. Our results show mechanisms by which small changes in Pfr, as well as the complex interaction of changes in Pfr and BAP, may limit the use of Vmax in detecting bronchodilation at different airway sites.

Airway Resistance↗
PubMed1995

Autonomic regulation of tissue resistance in the guinea pig lung.

Although the autonomic nervous system is known to influence airway tone and resistance in both the normal and inflamed lung, its effects on tissue resistance (Rti) have not been defined. To characterize autonomic neural control of Rti in the lung, we measured airway resistance (Raw) and Rti, lung elastance, and lung hysteresivity after adrenergic, cholinergic, and nonadrenergic noncholinergic (NANC) blockade in anesthetized mechanically ventilated guinea pigs by using the alveolar capsule technique. Five animals received 1 mg/kg i.v. phentolamine (alpha-blocker), eight received 1 mg/kg i.v. propranolol (beta-blocker), six received 0.1 mg/kg i.v. atropine (parasympatholytic), six had surgical bilateral vagotomy, and five were treated 14 days before study with 50 mg/kg sc capsaicin (peptidergic neurotransmitter depleter). Measurements were recorded at 5- to 10-min intervals for 120 min after pharmacological induction of autonomic blockade. Capsaicin treatment resulted in decreases in lung resistance (RL), Raw, and dynamic elastance (Edyn) compared with controls but Rti was not significantly affected. beta-Blockade resulted in significant increases in RL, Raw, and Edyn but did not affect Rti. alpha-Blockade and vagolytic maneuvers had no effect on RL, Raw, Rti, or Edyn. Furthermore, there was no effect of cholinergic, adrenergic, or NANC blockade on the relationship between Rti or elastance and breathing frequency or mean lung volume during tidal breathing. Our results suggest that, in the normal guinea pig lung, baseline Raw is modulated by both the beta-adrenergic and NANC nervous systems but Rti tone is largely independent of nervous system regulation.

Airway Resistance↗
PubMed2004

Energetic cost of breathing, body composition, and pulmonary function in horses with recurrent airway obstruction.

This study was conducted to determine whether horses with naturally occurring, severe chronic recurrent airway obstruction (RAO) 1). have a greater resting energy expenditure (REE) than control horses, 2). suffer body mass depletion, and 3). have significantly decreased REE after bronchodilation and, therefore, also 4). whether increased work of breathing contributes to the cachexia seen in some horses with RAO. Six RAO horses and six control horses underwent indirect calorimetric measures of REE and pulmonary function testing using the esophageal balloon-pneumotachograph method before and after treatment with ipratropium bromide, a parasympatholytic bronchodilator agent, at 4-h intervals for a 24-h period. Body condition scoring was performed, and an estimate of fat mass was determined via B-mode ultrasonography. O(2) and CO(2) fractions, respiratory airflow, respiratory rate, and pleural pressure changes were recorded, and O(2) consumption, CO(2) production, REE, pulmonary resistance, dynamic elastance, and tidal volume were calculated. In addition, we performed lung function testing and calorimetry both before and after sedation in two control horses. RAO horses had significantly lower body condition scores (2.8 +/- 1.0 vs. 6.4 +/- 1.2) and significantly greater O(2) consumption than controls (4.93 +/- 1.30 vs. 2.93 +/- 0.70 ml.kg(-1).min(-1)). After bronchodilation, there was no significant difference in O(2) consumption between RAO horses and controls, although there remained evidence of residual airway obstruction. There was a strong correlation between O(2) consumption and indexes of airway obstruction. Xylazine sedation was not associated with changes in pulmonary function but did result in markedly decreased REE in controls.

Adrenergic alpha-Agonists↗
PubMed1989

Asthma pharmacology: industrial/clinical interface.

The disease of asthma remains poorly understood. Hence, considerable latitude has been afforded to pharmacologists concerned to identify novel compounds for development as anti-asthma drugs. Compounds can be selected (1) on the basis of known efficacy as bronchodilator (beta-adrenoceptor agonists, parasympatholytics and xanthines) and prophylactic (cromoglycate and ketotifen) or anti-inflammatory (glucocorticosteroids) actions; (2) by reference to current theories of asthma pathogenesis, e.g., inhibition of the formation and action of autoacoids (leukotrienes, platelet-activating factor) or cytokines (GM-CSF, IL-5), or (3) by reference to hitherto unexplored physiological processes (K+ channel activation, PDE isoenzyme inhibition, selective immunosuppressive actions). There is a need to test whether the rationale for drug selection is justified. This can only be resolved by study of asthma patients, since normal subjects may respond inappropriately. Thus, normal subjects do not exhibit airway obstruction or airway hyperreactivity and hence do not respond to bronchodilator substances. Similarly, normal subjects respond to platelet-activating factor with a cellular infiltrate in which neutrophils predominate in contrast to atopic asthmatics who exhibit an eosinophilia. It follows that compound discovery and evaluation must be an iterative procedure in which animal studies are supplemented by clinical studies and vice versa. This is most readily achieved by establishing clinical research that is a complementary to preclinical research.

Asthma↗
PubMed1995

Bilateral acute angle-closure glaucoma after dexfenfluramine treatment.

We report the case of a patient with narrow angles who had an attack of bilateral acute angle-closure glaucoma precipitated by dexfenfluramine, a serotoninergic drug developed for appetite suppression. Although the exact mechanism remains uncertain, the pupillary block observed in our case may be the result of the serotoninergic or indirect parasympatholytic properties of the drug on the iris sphincter muscle. Serotonergic psychoactive drugs should be prescribed cautiously in patients with known narrow angles and should be monitored by an ophthalmologist.

Appetite↗
PubMed1981

Ipratropium nasal spray: a new treatment for rhinorrhea in the common cold.

A need is often present for symptomatic treatment of the common cold. A blocked nose can be opened by a vasoconstrictor, but no effective therapy is known today for rhinorrhea. The aim of the present trial was to study the effect of the topically active parasympatholytic, ipratropium, on rhinorrhea. In a placebo-controlled group comparative trial, 80 micrograms of ipratropium were taken as a nasal spray 4 times daily for 1 wk by 40 adults with spontaneously occurring common colds. All subjects administered an intranasal vasoconstrictor (xylomethazoline, 0.1%) 5 min before administering placebo or ipratropium. Ipratropium treatment resulted in a significant reduction in nasal discharge compared with that of placebo treatment during the whole treatment period (p less than 0.001), but the drug was especially effective the first 3 days, when the watery secretion was predominant. It was concluded that this new spray can be of value in the first days of a cold, when nasal discharge is a nuisance.

Administration, Intranasal↗
PubMed1984

Glycopyrrolate and atropine inhalation: comparative effects on normal airway function.

Bronchodilation was produced in normal subjects by inhalation of high doses of a quaternary parasympatholytic agent (glycopyrrolate), and responses were compared with those of atropine and a placebo. Both drugs induced significant increases in specific airway conductance (SGaw) and forced expiratory flows, but the effects of glycopyrrolate were sustained significantly longer (greater than 6 h). Whereas atropine produced an increased heart rate (26%) and severe dry mouth in all subjects, these symptoms were absent with glycopyrrolate and placebo. Therefore, glycopyrrolate produces significant bronchodilation of long duration but free of the side effects of muscarinic blockade that characterize atropine inhalation.

Adult↗
PubMed1977

Relative contributions of large and small airways to flow limitation in normal subjects before and after atropine and isoproterenol.

Bronchodilatation was produced in normal subjects by the inhalation of atropine, a parasympatholytic agent, and isoproterenol, a beta adrenergic stimulator. Density dependence of maximal expiratory flow (Vmax), expressed as a ratio of Vmax with an 80% helium-20% oxygen gas mixture to Vmax with air at isolung volumes, indicated that the predominant flow regimes across upstream airways changed differently after each agent was given separately. After atropine Vmax increased, elastic recoil pressure did not change, and density dependence decreased. Utilizing the equal pressure points analysis which defines upstream and downstream segments of the intrathoracic airways at flow limitation, these results suggest a greater relative dilatation of the larger upstream airways such that more of the driving pressure is dissipated across the smaller airways in which flow is less dependent upon gas density. After isoproterenol Vmax increased, elastic recoil pressure did not change, and density dependence increased. This suggests a preferential dilatation of the smaller and more peripheral airways with less density-dependent flow regimes such that more of the driving pressure would be dissipated in the larger airways in which flow is more dependent upon gas density. Systematic decreases after isoproterenol lead independently to the same conclusion. After both agents together, Vmax increased and density dependence and critical alveolar pressures did not change from control, suggesting a relatively uniform dilatation of all the airways comprising the upstream segment.

Adult↗
PubMed1990

Autonomic pathophysiology in heart failure patients. Sympathetic-cholinergic interrelations.

We conducted this study in an effort to characterize and understand vagal abnormalities in heart failure patients whose sympathetic activity is known. We measured sympathetic (peroneal nerve muscle sympathetic recordings and antecubital vein plasma norepinephrine levels) and vagal (R-R intervals and their standard deviations) activities in eight heart failure patients and eight age-matched healthy volunteers, before and after parasympathomimetic and parasympatholytic intravenous doses of atropine sulfate. At rest, sympathetic and parasympathetic outflows were related reciprocally: heart failure patients had high sympathetic and low parasympathetic outflows, and healthy subjects had low sympathetic and high parasympathetic outflows. Low dose atropine, which is known to increase the activity of central vagal-cardiac motoneurons, significantly increased R-R intervals in healthy subjects, but did not alter R-R intervals in heart failure patients. Thus, our data document reciprocal supranormal sympathetic and subnormal parasympathetic outflows in heart failure patients and suggest that these abnormalities result in part from abnormalities within the central nervous system.

Adult↗