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Biomedical subjects

E H Chester

Publications and source records attributed to E H Chester.

At least 37 records · Page 2Linked to original sources
PubMed1978

Pi-Z phenotypes in a pulmonary clinic. Their prevalence and physiologic state.

A series of 1,458 consecutive patients referred to the Cleveland Veterans Administration Pulmonary Clinic for pulmonary function studies was evaluated for alpha 1-antitrypsin deficiency by determination of serum trypsin inhibitory capacity (STIC). Protease inhibitor (Pi) phenotyping was performed on all sera with STIC values less than 1.6 mg/ml. The following non-MM phenotypes were found: 1FZ, 32MZ, 2ZZ, 3SZ, 5SS, 33MS, 21M. The prevalence of Pi Z heterozygosity is 2.74%. This figure is not significantly greater than that observed in a healthy population. A group ( n = 12) with heterozygous Z phenotype (MZ + SZ) was compared with a control (MM) group (n = 13) matched for age, race and smoking history from this same population. Our findings indicate similar deviations from predicted normal values in both control (MM) and Z-heterozygotic groups for physiologic tests of airway resistance, lung volumes, diffusing capacity, and static and dynamic compliance. There was no significant difference between MM controls and MZ heterozygotes in the physiologic variables measured.

Adult↗
PubMed1978

Cardiac arrhythmias during routine tests of pulmonary function in patients with chronic obstruction of airways.

We studied the frequency of cardiac arrhythmias during routine tests of pulmonary function by using continuous electrocardiographic recording and a computerized method to quantitate arrhythmias. A total of 150 patients with chronic obstruction of airways were studied before, during, and after routine tests of pulmonary function performed before and after intermittent positive-pressure breathing (IPPB) with a bronchodilator aerosol. The only significant (P less than 0.01) change was an increased frequency of atrial premature beats during tests of pulmonary function. Spirometric studies, maximal voluntary ventilation, and IPPB with a bronchodilator aerosol were equally likely to induce atrial premature beats. Routine tests of pulmonary function represent an additional causal factor in producing arrhythmias in patients with obstruction of airways, although no clinical consequences were evident in the course of the study.

Adolescent↗
PubMed1978

Beta-adrenergic blockade of the lung. Dose-dependent cardioselectivity of tolamolol in asthma.

Beta-adrenergic blocking agents are widely used to treat disorders of cardiac rhythm and rate, angina, and hypertension. Propranolol is the most widely used beta-adrenergic blocking agent in this country. Because of its nonselective beta-adrenergic blocking effect, propranolol may be associated with significant bronchoconstriction in asthmatic subjects and in some patients with chronic obstructive pulmonary disease. Since tolamolol, a new beta-adrenergic blocking agent, has cardioselectivity in animals, we studied asthmatic subjects for six hours on three separate days in a double-blind crossover comparison of oral therapy with 40 mg of propranolol, its beta-adrenergic blocking equivalent dose of tolamolol (50 mg), and a high dose of tolamolol (100 mg). All three dosages had equipotent effects on heart rate and systolic pressure. The 50-mg dose of tolamolol had no effect on pulmonary function over six hours; however, both propranolol (40 mg) and the 100-mg dose of tolamolol had equivalent deleterious effects on airway resistance and on rates of expiratory flow. We conclude that the cardioselectivity of tolamolol is dose-limited but is present at the dosage of 50 mg, which is equivalent to the usual antiarrhythmic beta-adrenergic blocking dose of propranolol (40 mg).

Adult↗
PubMed1978

A calibrated delivery system for inhalation challenge of toluene di-isocyanate vapor.

The vapor of TDI, a chemical commonly used in the plastics industry, may be associated with pulmonary symptoms at various concentrations. Because of the high volatility and adsorptivity of TDI, it has been difficult to deliver known, dilute concentrations of TDI to test subjects in inhalation challenge studies. A delivery system has been developed which can be calibrated to deliver an air-TDI mixture having a given flow rate and TDI concentration. The delivered gas stream is produced by diluting a gas stream having a low flow rate and a fixed concentration of TDI with a high-flow-rate stream of TDI-free air. A TDI detector continuously monitors the concentration of the resultant mixture, which is delivered to the subject by means of a face mask. For dilute mixtures, the output concentration is proportional to the ratio of the input flow rates; the proportionality factor depends on temperature and the geometry of the system. The flows for the described system could be regulated to produce concentrations in the range 0.0 to 0.08 ppm which remain stable to within +/- 10%.

Cyanates↗
PubMed1978

On respirable organic antigens, mattresses and some idiopathic lung diseases.

In surveying the environment of workers in a mattress factory thermophilic actinomycetes as well as phycomycetes and aspergillus species were isolated readily from work room dust, finished bat, sissal and the interior of baled linters. Those persons working with cotton products were shown to have a heavy, daily exposure to organisms known to be implicated in the pathogenesis of hypersensitivity pneumonitis. The authors suggest that further study of the inhaled antigens to which cotton workers are exposed is indicated before discarding immunologic mechanisms to explain the development of byssinosis and other pulmonary disorders to which such workers are subject.

Alveolitis, Extrinsic Allergic↗
PubMed1977

Phthalic anhydride asthma.

A patient with occupational asthma caused by phthalic anhydride is described. Inhalation challenges under laboratory control produced immediate and delayed asthmatic responses. Repeat exposure to phthalic anhydride after treatment with cromolyn sodium showed inhibition of the late but not early bronchoconstrictive, asthmatic response.

Adult↗
PubMed1977

Pulmonary injury following exposure to chlorine gas. Possible beneficial effects of steroid treatment.

Two sisters were exposed to chlorine gas in toxic quantities in the same room of their home during an industrial accident. One was hospitalized and treated with corticosteroids and oxygen therapy, while the other received evaluation in the emergency room, and brief oxygen therapy and was released without corticosteroid therapy. Pulmonary physiologic studies have been performed on both patients at intervals following the exposure. The treated patient was stable, with normal results on studies of pulmonary function at the end of two years, while the sibling not treated with corticosteroids had demonstrable abnormalities of gas exchange which persisted during 55 months of observation. This "natural experiment" gives evidence of prolonged detrimental effects of sublethal exposure to chlorine gas on human pulmonary function in some patients. The effect of the differences in treatment between the two siblings cannot be definitely assessed in this single situation.

Accidents, Occupational↗
PubMed1977

Multidisciplinary treatment of chronic pulmonary insufficiency. 3. The effect of physical training on cardiopulmonary performance in patients with chronic obstructive pulmonary disease.

We examined the effect of physical training on cardiopulmonary function in 21 patients with chronic obstructive pulmonary disease and compared the results with similar observations in eight untrained patients. The training consisted of daily walking on a treadmill at increasing speeds and grades and other graded physical exercises. Evaluation of pulmonary function, including spirometric studies, lung volumes, and arterial blood gas levels, showed no significant change after training. Hemodynamic functions, including heart rate, cardiac index, stroke index, pulmonary vascular resistance, and arteriovenous oxygen content difference, were similarly unchanged at comparable submaximal loads. Pulmonary arterial wedge pressure increased after training in the treated group at rest and during exercise, but this may be related to changes in respiratory mechanics. Consumption of oxygen and minute ventilation decreased in the treated group during treadmill exercise, suggesting improved neuromuscular coordination and efficiency of walking on the treadmill. Total work performed on the treadmill increased significantly in the trained group. This increase was unexplained by physiologic observations but was thought to be due in part to increased efficiency of walking and increased motivation. We conclude that improvement in the capacity for exercise following physical training for four weeks is not associated with improvement in cardiopulmonary function at submaximal exercise.

Blood Pressure↗
PubMed1977

Multidisciplinary treatment of chronic pulmonary insufficiency. 4. The influence of intrathoracic pressure variations on increases in pulmonary vascular pressure during exercise in patients with chronic obstructive pulmonary disease.

In the present era of direct monitoring of pressure in patients with chronic obstructive pulmonary disease (COPD), an appreciation of all factors that may influence the observed pulmonary vascular pressures is essential. Our study examines the impact of respiratory variations in intrathoracic pressure on the recorded pulmonary vascular pressures in 28 patients with COPD. Althouth pulmonary hypertension was present in only nine subjects at rest, all had an abnormal increase in the mean pulmonary arterial pressure during supine exercise. In 15 subjects, this abnormal response was, in part, related to an increase in pulmonary arterial wedge pressure to 15 mm Hg or more. The increase in pulmonary arterial wedge pressure was directly related to the amplitude of the peak-to-peak respiratory variation of such wedge pressure. This variation correlated with the specific airway resistance but was not related to the arterial oxygen pressure or pulmonary vascular resistance. These findings indicate the important influence of exaggerated respiratory effort on the measurement of pulmonary arterial wedge pressure and mean pulmonary arterial pressure in patients with chronic obstructive pulmonary disease.

Airway Obstruction↗
PubMed1975

Moment analysis of multibreath lung washout.

A moment analysis of multibreath nitrogen washout has been developed to provide a sensitive, quantitative measure that characterizes the inhomogeneity of pulmonary ventilation. To test the analysis scheme, we studied 5 normal subjects and 16 subjects with obstructive lung disease who performed each washout test at constant tidal volume and frequency. Subjects executed the wahout test 3-4 times at different tidal volumes (0.5-1.5 liters) and frequencies (10-30/min). Plotting washout data as dimensionless end-tidal nitrogen concentration versus the cumulative expired volume normalized by the functional residual capacity (CEV/FRC) renders the washout curves of each individual almost superposab le despite changes in breathing frequency and tidal volume from test to test. The dimensionless washout curve is treated as a distribution from which the normalized first (M1/Mo) and second (M2/Mo) moments are obtained. These parameters clearly display diagnostic clustering for various disease states. With respect to the normal subjects, the magnitude of M1/Mo was 26% greater for asthmatics, 38% greater for bronchitics, and 52% greater for emphysematics. This moment analysis provides an objective, quantitative assessment of the extent of ventilation inhomogeneities without specification of a lung model.

Airway Obstruction↗