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Biomedical subjects

R T Abboud

Publications and source records attributed to R T Abboud.

At least 55 records · Page 3Linked to original sources
PubMed1982

The short-term bronchodilator effects of fenoterol and ipratropium in asthma.

We studied the bronchodilator effects of inhaled fenoterol, a relatively selective beta-2 adrenergic agent, and ipratropium an anticholinergic drug, singly and in combination in 10 patients with asthma. The period of observation was 6 hr after aerosol administration. The six drug regimens used were fenoterol 100 micrograms, fenoterol 200 micrograms fenoterol 50 micrograms combined with 20 micrograms of ipratropium, fenoterol 100 micrograms combined with 40 micrograms of ipratropium, 40 micrograms of ipratropium, and placebo. Measurements consisted of spirometry with determination of forced expiratory volume in one second (FEV1), maximal expiratory flow at 50% of vital capacity (V50), specific airway conductance, lung volumes, and heart rate. Bronchodilation with regimens containing fenoterol was rapid, with 75% of the maximum response achieved by 5 min, while the peak effect of ipratropium was delayed for 1 to 2 hr. Fenoterol 100 micrograms produced approximately half the degree of improvement in FEV1 and V50 compared with 200 micrograms of fenoterol. The addition of 40 micrograms of ipratropium to 100 micrograms of fenoterol resulted in bronchodilation equivalent to 200 micrograms fenoterol and was associated with a more prolonged effect than fenoterol 100 micrograms. Tremor was observed in two-subjects inhaling fenoterol 200 micrograms but was not observed with any other regimen. It is concluded that the combination of inhaled ipratropium and fenoterol is an effective bronchodilator in asthma, achieving efficacy similar to that of fenoterol alone but with fewer side effects.

Adult↗
PubMed1982

Lack of relationship between ABH secretor status and lung function in pulp mill workers.

To evaluate whether persons who do not secrete blood group antigens in their saliva (ABH nonsecretors) are more prone to develop respiratory symptoms or lung function abnormalities than are ABH secretors, we determined ABH secretor status of 1,422 pulp mill workers who took part in an occupational health survey. There were 331 nonsecretors (23.3% of total population), and the remainder were secretors. Respiratory symptoms were not significantly different in nonsecretors when compared with secretors. Spirometric results for forced expiratory volume in one second (FEV1), maximal mid-expiratory flow (MMEF), forced vital capacity (FVC), and FEV1/FVC% were not significantly different in nonsecretors when compared with secretors, irrespective of smoking status or occupational exposure. Likewise, there was no significant difference in prevalence rates of abnormal FEV1, MMEF, or FEV1/FVC%, in nonsecretors when compared with secretors. It is concluded that ABH secretor status is not related to respiratory symptoms or spirometric abnormalities in pulp mill workers. This study suggests that ABH nonsecretor status is not a significant risk factor for the development of chronic obstructive pulmonary disease.

ABO Blood-Group System↗
PubMed1981

Use of maximal expiratory flow-volume curves with air and helium-oxygen in the detection of ventilatory abnormalities in population surveys.

Flow-volume curves with air and helium, and spirometry were obtained in 423 subjects during epidemiologic health surveys; subjects were divided into 4 groups: nonsmokers and smokers not exposed to air pollutants at work, and nonsmoking and smoking grain elevator workers. The data obtained from 78 healthy nonsmokers who were not exposed to any air contaminants at work and had no respiratory symptoms were used to develop "normal" prediction equations for each of the following parameters: forced expiratory volume in one second (FEV1), maximal mid-expiratory flow, maximal expiratory flow at 50% of vital capacity while breathing air (Vmax50), the increase in Vmax50 after breathing a mixture of helium and O2 (delta Vmax50), and the volume of isoflow (VisoV). The prediction equations thus obtained from normal nonsmokers agreed with those published in the literature. The coefficient of variation was higher for delta Vmax50 (40.7%) and VisoV (57.6%) than for FEV1 (17.7%) or Vmax50 (27.7%). Comparison of results in smokers and nonsmokers who were not exposed to any air contaminants at work indicated that Vmax50 was the best test for discriminating the effect of cigarette smoking, whereas delta Vmax50 and VisoV were not significantly different. The FEV1 was the best discriminator of the effects of grain dust. There was poor concordance among FEV1, Vmax50, and delta Vmax50 or VisoV. We concluded that FEV1 and Vmax50 are more useful parameters than are delta Vmax50 and VisoV for detecting ventilatory abnormalities in a smoking, working population and in grain elevator workers. The results suggest that the addition of the more time-consuming test, the helium flow-volume curve, is unlikely to contribute any further useful information among the populations surveyed.

Air Pollutants, Occupational↗
PubMed1979

Interrelationships between neutrophil elastase, serum alpha, -antitrypsin, lung function and chest radiography in patients with chronic airflow obstruction.

We assayed protease and elastase activity of lysosomal granules of purified neutrophil suspensions in 58 patients with chronic irreversible airflow obstruction and compared them to 26 healthy control subjects. Denatured hemoglobin and tritiated elastin were used as substrates for protease and elastase assays. Forty-two patients had M antitrypsin phemotype, five had MS, and 11 had Z variant (five were homozygotes and six were heterozygotes). We did not find significant differences in mean lysosomal elastase or protease activity between patients with normal antitrypsin and control subjects; however, a few patients had concentrations of neutrophil elastase that exceeded the range among control subjects. There was no significant correlation between neutrophil protease or elastase activity and age, smoking, degree of airway obstruction, diffusing capacity, lung elastic recoil, or radiologic presence of emphysema in patients with M and MS antitrypsin. In patients with Z variant antitrypsin, protease and elastase concentrations per unit of lysosomal protein were not significantly different from those in control subjects or M patients; however, both elastase and protease content per 108 neurtophils was significantly higher in homozygous and heterozygous Z patients as compared to normalsubjects and M patients, which suggest an increase in the neutrophil content of protease and elastase in patients with Z antitrypsin deficiency. These results suggest that hte concentrations of protease and elastase in neutrophils do not appear to interact as additive risk factors in the pulmonary impairment of most patients with chronic airflow obstruction, but may be of importance as risk factors in patients with Z or MZ phenotype and in a few patients with M phenotype.

Forced Expiratory Volume↗
PubMed1978

Goodpasture's syndrome: diagnosis by transbronchial lung biopsy.

A 28-year-old man developed recurrent hemoptyses, breathlessness, anemia, and bilateral pulmonary infiltrates after mild smoke inhalation. He had no laboratory evidence of kidney involvement. Transbronchial lung biopsy showed erythrocytes, iron-containing macrophages within alveolar spaces, normal basement membranes, and strongly positive linear staining of alveolar septa for immunoglobulin G (IgG). Serum antiglomerular basement-membrane antibody was strongly positive by radioimmunoassay. Kidney biopsy showed normal findings by light and electron microscopy but strongly positive linear staining of glomerular capillaries for IgG. Follow-up 9 months later while the patient was taking prednisone revealed no clinical evidence of pulmonary or renal disease. This case shows that immunopathologic study of transbronchial lung biopsies is helpful in differentiating between Goodpasture's syndrome and idiopathic pulmonary hemosiderosis, while the absence of clinical and microscopic evidence of kidney disease does not exclude Goodpasture's syndrome.

Adult↗
PubMed1976

Effect of oral administration of delta-tetrahydrocannabinol on airway mechanics in normal and asthmatic subjects.

We performed a double-blind study on the effect of oral administration of 10 mg of delta9-tetrahydrocannabinol on specific airway conductance (Gaw/VL) and the maximal expiratory flow at 50% of vital capacity (Vmax 50%) in six control and six asthmatic subjects. In control subjects, there was a slight but statistically significant increase in Gaw/VL after oral administration of delta9-tetrahydrocannabinol; however, there was no significant increase in Vmax 50%. One of the asthmatic patients developed severe bronchoconstriction following administration of delta9-tetrahydrocannabinol; among the remaining five patients, there were variable changes in Gaw/VL and Vmax 50% after oral administration of delta9-tetrahydrocannabinol, but mean changes were not significant. Mild effects on the central nervous system (CNS) were observed in three subjects; six subjects, three of whom had unpleasant mood changes, had more prominent CNS effects. We concluded that oral administration of delta9-tetrahydrocannabinol is unlikely to be of therepeutic value in asthma, since its bronchodilator action was mild and inconstant and was associated with significant CNS effects. Moreover, one asthmatic patient developed severe bronchoconstriction following oral administration of delta 9-tetrahydrocannabinol.

Adult↗
PubMed1975

Comparison of maximal mid-expiratory flow, flow volume curves, and nitrogen closing volumes in patients with mild airway obstruction.

Maximal mid-expiratory flow (MMEF), maximal expiratory flow volume (MEFV) curves obtained with a wedge spirometer, and nitrogen closing volumes were determined in 38 patients with mild airway obstruction. Seventeen patients had asthma in remission and 21 had bronchitis. In all of them the forced expiratory volume in one second was within the normal range. Results were compared with predicted data in the literature and with a group of normal control subjects. In the patients with asthma, compared to predicted flow rates, MMEF was abnormal in 5, MEFV curves were abnormal in at least 8; closing volume was abnormally increased in only one patient, and an abnormal slope of the alveolar plateau was present in 4 additional patients. In the patients with bronchitis, compared to predicted flow rates, -MEF was reduced in 5, MEFV curves were abnormal in at least 7; increased closing volumes were present in 6, and the slope of the alveolar plateau was abnormal in 3 other patients. When flow rates were compared with those of normal control subjects, MMEF was about as frequently abnormal as MEFV curves, suggesting that the discrepancy between abnormal MMEF AND MEFV curves was due to variability of the predicted data. The results indicated that flow rates can be abnormal in subjects with normal closing volumes and a normal slope of the alveolar plateau, and that MEFV curves can be more sensitive than closing volume in detecting abnormalities in patients with mild airway obstruction. The results suggested that the use of both MEFV curves and the closing volume test for screening would defect functional abnormalities more frequently than either test alone.

Adult↗