Search PubMedSearch

Biomedical subjects

M A Sackner

Publications and source records attributed to M A Sackner.

At least 19 recordsLinked to original sources

Hemodynamics in teenagers and asthmatic children during exercise.

Seventeen normal teenagers and eight asthmatic children were studied during submaximal exercise on a bicycle ergometer. A modification of a noninvasive multiple gas rebreathing method was utilized for the estimation of pulmonary capillary blood flow (Qc), diffusing capacity (DL), oxygen consumption (VO2), functional residual capacity (FRC), and pulmonary tissue plus capillary blood volume (VTPC). Significant increases in Qc, DL, VO2, and heart rate occurred in both groups of subjects. Regression equation of Qc equaled 6.0 + 0.0078 VO2 (ml/min) in the teenagers and 3.39 + 0.0082 X VO2 (ml/min) in the asthmatic children. The values of DL as a function of VO2 in both groups were similar to previously reported data. No significant changes in FRC or VTPC occurred in either group during exercise. This method appears to be an acceptable noninvasive way of studying exercise physiology in healthy or sick children.

Adolescent

Effect of exercise on nasal mucous velocity and nasal airflow resistance in normal subjects.

Nasal mucous velocity and nasal airflow resistance were measured in nine healthy subjects before, during 5 min, and 1 h after submaximal exercise of 20 min with a cycle ergometer set in such a way that heart rate ranged from 125 to 135 beats/min. Nasal mucous velocity rose from a base line of 7.6-12.7 mm/min during exercise and returned to the base-line value 5 and 60 min after exercise. The mean expiratory nasal airflow resistance at a flow of 0.4 l/s decreased from a base line of 1.6-0.6 cmH2O . (l/s)-1 during exercise and returned to the baseline value 5 and 60 min after exercise.

Adolescent

Effect of local radioactivity on trachael mucous velocity of sheep.

The effects of local isotope radiation and x-ray radiation on mucociliary transport of sheep were investigated. X-ray radiation from fluoroscopy equivalent to that used to determine tracheal mucous velocity in intact animals (approximately 3 min) did not alter transport of teflon discs in an isolated sheep trachael preparation. In conscious sheep, 2 ml of a solution containing 8 mCi of macroaggregates of albumin labeled with technetium-99m (99mTc) and 99mTc-pyrophosphate were instilled under direct vision into the trachea via a fiberoptic bronchoscope, providing an actual deposition on the tracheal epithelium of 1.8 to 2 mCi. Physiologic saline and unlabeled macroaggregates of albumin were instilled as control solutions. Tracheal mucous velocity measured by movement of teflon discs increased by 93.2 per cent with 99mTc-labeled macroaggregated albumin and 86.7 per cent with 99mTc-pyrophosphate (P less than 0.01), but no significant increase occurred after saline or unlabeled macroaggregates of albumin. Discrepancies in the values of trachael mucous velocity determined using inert particles and radioactive tracer solution or aerosols might be related in part to the local effects of the tracer radiation.

Animals

Distribution of ventilation in normal children.

Measurements of closing volume and the distribution fo ventilation by both single-breath (SBN2) and multiple-breath nitrogen washout methods were obtained in 376 healthy boys and girls, ages 6 to 18 years. A closing volume could be demonstrated in 39 percent of the subjects, and closing volume expressed as percentage of vital capacity did not change with height. Closing capacity expressed as percentage of total lung capacity showed a slight decrease with height. The slope of phase III of the SBN2 curve decreased with height. Single compartment N2 washout curves were observed in 72 percent of the subjects, and the incidence of single compartment curves increased with age. In those subjects with two compartment N2 washout curves, the relative compartmental ventilation became more even with increasing height. Our observations suggest that parallel units among peripheral airways grow at different rates.

Adolescent

A roentgenographic method for measuring nasal mucous velocity.

Nasal mucous velocity was estimated by following the motion of radiopaque discs of Teflon by means of a fluoroscopic image intensifier. From 5 to 10 discs were deposited on the superior surface of the inferior turbinate with a forceps. No local anesthesia was employed and the subjects experienced no discomfort. The linear velocity of the discs was obtained by playing the videotape onto a television monitor, measuring distance with a ruler, and dividing by elapsed time. Duplicate runs of 1-2 min, 15 min apart were very reproducible but runs at 4-h intervals or daily over a 5-day period had a coefficient of variation of 30%. Average nasal velocity for individual ranged from 0 to 22.5 mm/min and group means ranged from 6. 8 to 10.8 mm/min. There was no statistically significant difference in nasal mucous velocity between young and elderly subjects nor was there a sexual difference. The saccharin test of nasal mucous transport was unsatisfactory because of inability to repeat the test more often than 1-2 h and its propensity to produce mild discomfort in a significant number of subjects. Saccharin times did not correlate significantly with values of nasal mucous velocity.

Adult

The effect of nasal decongestant on nasal mucous velocity.

Nasal mucous velocity was measured in 13 healthy nonsmokers before and 10 min after topical application of 2 alpha adrenergic nasal decongestant sprays, phenylephrine and tetrahydrozoline. Phenylephrine increased nasal mucous velocity from 8.4 +/- 2.7 mm per min (mean +/- SD) to 13.7 +/- 4.8 mm per min and tetrahydrozoline from 8.1 +/- 3.8 mm per min (mean +/- SD) to 13.8 +/- 5.1 mm per min. These increases were significant (P less than 0.01) when compared to topical application of phenylephrine and tetrahydrozoline vehicles, normal saline, and sham (empty aerosol container).

Administration, Topical

Effects of sulfuric acid aerosol on cardiopulmonary function of dogs, sheep, and humans.

Submicronic aerosol of sulfuric acid (H2SO4) originates from the burning of fossil fuels and discharge of vapor from the automobile engine equipped with the catalytic converter. This study was conducted to determine whether brief exposure to this aerosol in high concentrations adversely affects the cardiopulmonary system. In all studies, submicronic aerosol of sodium chloride was used as a control. Anesthetized dogs that breathed H2SO4 aerosol in concentrations up to 8 mg per m3 showed no effects on respiratory resistance, static lung compliance, and functional residual capacity. A 4-hour exposure to H2SO4 aerosol (4 mg per m3) produced no significant changes in mechanics of breathing, functional residual capacity, pulmonary and systemic arterial blood pressures, cardiac output, heart rate, and arterial blood gas tensions. Conscious sheep that breathed H2SO4 aerosol in concentrations up to 14 mg per m3 for 20 min had no alteration of tracheal mucous velocity in an immediate 3-hour follow-up period or 5 to 10 days later. Conscious sheep that breathed H2SO4 aerosol (4 mg per m3) for 4 hours had no significant alteration of tracheal mucous velocity immediately and 2 hours thereafter. Both normal and asthmatic adults breathing H2SO4 aerosol in concentrations up to 1 mg per m3 for 10 min showed no significant alteration of lung volumes, distribution of ventilation, ear oximetry, dynamic mechanics of breathing, oscillation mechanics of the chest-lung system, pulmonary capillary blood flow, diffusing capacity, O2 consumption, and pulmonary tissue volume. No delayed effects in pulmonary function nor exacerbation of bronchial asthma were observe during a follow-up period of a few weeks. The present study indicates that single exposure to submicronic H2SO4 aerosol does not produce an immediate or a delayed adverse effect on cardiopulmonary function in anesthetized dogs, conscious sheep, and normal and asthmatic adults.

Aerosols

Effects of terbutaline aerosol in reversible airway obstruction.

Aerosol terbutaline is an effective bronchodilator agent with at least a seven-hour duration of action in patients with reversible obstruction of the airways. Inhalation of up to 1.5 mg of this drug is not associated with significant alterations of pulse rate and blood pressure. Although a dose-related improvement of specific airway conductance was demonstrated 30 minutes after administration of the drug, no such effect was observed in measurements of the forced expiratory volume in one second.

Aerosols

Hemodynamic effects of smoking cigarettes of high and low nicotine content.

We studied the hemodynamic effects of smoking cigarettes with high and low contents of nicotine in young smokers free of coronary arterial disease. The smoking of one cigarette with a high content of nicotine produced a peak rise in cardiac output of 32 percent above baseline values, and the effect persisted for one hour. Smoking a cigarette with a low content of nicotine produced a peak rise of 13 percent above baseline values, with a duration of five minutes. The rise in cardiac output was almost entirely attributable to tachycardia, since stroke volume remained relatively constant. The smoking of a cigarette with high nicotine content also caused greater and more sustained elevation in systemic blood pressure than smoking a cigarette with low nicotine content. Thus, there was a responsiveness to the dose of nicotine in cigarettes smoked by young smokers free of coronary arterial disease.

Adolescent

Effects of drinking hot water, cold water, and chicken soup on nasal mucus velocity and nasal airflow resistance.

Nasal mucus velocity and nasal airflow resistance were measured in 15 healthy subjects before and at 5 and 30 minutes after drinking hot water by sip or straw, hot chicken soup by sip or straw, and cold water by sip. A sham drinking procedure with straw was also employed. Hot water by sip increased nasal mucus velocity from 6.2 to 8.4 mm per min, hot chicken soup by sip from 6.9 to 9.2 mm per min, and chicken soup by straw from 6.4 to 7.8 mm per min five minutes after administration. These increases were statistically significant compared to cold water, hot water by straw and sham. All values returned to their baseline at 30 minutes except cold water which significantly decreased the nasal mucus velocity from 7.3 to 4.5 mm per min. There were no significant changes from baseline in nasal airflow resistance 5 and 30 minutes following the above treatments. We conclude that drinking hot fluids transiently increases nasal mucus velocity in part or totally through the nasal inhalation of water vapor. Hot chicken soup, either through the aroma sensed at the posterior nares or through a mechanism related to taste, appears to possess an additional substance for increasing nasal mucus velocity. Finally, hot liquid might be superior to cold liquids in the management of fluids in upper respiratory tract infections.

Adult

Effects of S-carboxymethylcysteine on tracheal mucus velocity.

The effects of S-carboxymethylcysteine on tracheal mucus velocity were assessed in a double blind crossover study between 2 grams S-carboxymethylcysteine and placebo. Subjects included six healthy non-smokers, eight smokers with small airway disease and chronic simple bronchitis, and eight subjects with chronic obstructive bronchitis. Tracheal mucus velocity was measured prior to and two and three hours after each subject had ingested S-carboxymethylcysteine or placebo. No significant change in tracheal mucus velocity occurred after placebo or S-carboxymethylcysteine in any of the groups, indicating that the drug has no acute effect on mucus transport.

Adult