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Biomedical subjects

R R Martin

Publications and source records attributed to R R Martin.

At least 181 records · Page 10Linked to original sources
PubMed1977

Comparison of aryl hydrocarbon hydroxylase induction in cultured blood lymphocytes and pulmonary macrophages.

Aryl hydrocarbon hydroxylase induction was studied in cultured peripheral blood lymphocytes and pulmonary alveolar macrophages from 15 smokers and 8 nonsmokers with a variety of pulmonary diseases. Enzyme levels in lymphocytes from cigarette smokers cultured in medium without an inducing agent were 57+/-6 mU/10(6) cells (mean+/-SEM), while enzyme levels in lymphocytes from nonsmokers were 20+/-2 mU/10(6) cells (P < 0.001). When lymphocytes were cultured in the presence of the inducing agent, benzo-(a)anthracene, enzyme activity was increased to 168+/-23 mU/10(6) cells in smokers' cells and 99+/-22 mU/10(6) cells in lymphocytes from nonsmokers (P < 0.04). When noninduced enzyme values in cultured macrophages were compared, smokers' cells had enzyme levels of 45+/-5 mU/10(6) cells, whereas nonsmokers had enzyme activity of 24+/-2 mU/10(6) cells (P < 0.002). However, pulmonary macrophages from smokers or nonsmokers, cultured in the presence of benzo(a)-anthracene, had similar levels of induced enzyme activity (P > 0.1). A positive correlation was observed for nonsmokers (r = 0.596, P > 0.1 <0.2) or smokers (r = 0.640, P < 0.04), when enzyme values for noninduced cultures of macrophages and lymphocytes from individual patients were simultaneously compared. Enzyme values for macrophages and lymphocytes cultured in the presence of an inducer also revealed a positive correlation for individual smokers (r = 0.801, P < 0.001) or nonsmokers (r = 0.785, P < 0.01). Inducibility (expressed as fold-induction) for macrophages and lymphocytes from individual patients was also positively correlated (r = 0.889, P < 0.001 for nonsmokers and r = 0.942, P < 0.001 for smokers). These results indicate that the capacity for aryl hydrocarbon hydroxylase induction is similar whether tested in lymphocytes or pulmonary macrophages from this group of pulmonary disease patients.

Adult↗
PubMed1977

Lymphoproliferative responses to antigens mediated by human pulmonary alveolar macrophages.

We evaluated the ability of human pulmonary alveolar macrophages (PAMs) to mediate (3H)-thymidine incorporation by blood lymphocytes severely depleted of monocytes when stimulated with soluble microbial and allogeneic lymphocyte antigens. Low (less than 2%) concentrations of PAM's from nonsmokers or blood monocytes did not support optimal responses. Over all, at greater than or equal to 10% concentrations, PAM's from nonsmokers supported higher responses than monocytes. At less than or equal to 10% concentrations, PAM's from heavy cigarette smokers mediated significantly less incorporation than did similar concentrations of PAM's from nonsmokers (p less than 0.05). The findings indicate that PAM's from healthy nonsmokers are functionally competent macrophages in terms of mediating lymphoproliferation in cultures stimulated with antigens. This classical macrophage function is impaired with cigarette smoking.

Adult↗
PubMed1977

Mechanical trauma in leukocytes.

Mechanical and surface traumas in cardiopulmonary bypass circuits alter the function and morphology of human leukocytes. The effect of controlled in vitro shear stess (0 to 2,000 dynes/cm2, 2 to 10 min, 37 degrees C) on electronic cell count, morphology, adhesiveness, and phosphatase cytochemical staining was studied on whole blood from normal donors. Electronic cell counts droppped significantly after shear stress exposure (25% at 600 dynes/cm2 for 10 min). The frequency of disrupted leukocytes in blood smears increased with shear stress above 150 dynes/cm2, and aggregates of the disrupted cells appeared after exposure to higher shear stresses (450 dynes/cm2, 10 min). Cytochemical staining of the alkaline phosphatase in the granules of intact neutrophils was significantly reduced by the application of shear stress (150 dynes/cm2 for 10 min, or greater), but staining of acid phosphatase-containing granules was almost unaffected. Increased cell retention in columns of nylon fibers suggests that increased leukocyte adhesiveness results from exposure to shear stress. Thus exposure to shear stress may alter or disrupt leukocyte morphology and function at values somewhat lower than the 1,500 dynes/cm2 for 2 min which is required to hemolyze erythrocytes.

Cell Adhesion↗
PubMed1976

Influence of bronchomotor tone on regional ventilation distribution at residual volume.

We studied the topographical distribution of 133Xe boluses inhaled slowly from RV, as well as the distribution of regional volumes at RV (RVr) in seven seated normal subjects before and after aerosolized isoprenaline (ISO) and after aerosolized methacholine hydrochloride (Mech). After Mech the ratio of inhaled 133Xe in the upper lung regions to that in lower lung regions (U/L) decreased from 3.21 +/- .33 (mean +/- 1 SE) to 1.27 +/- 0.12 (P less than 0.001) and returned to 3.89 +/- 0.55 after Iso. Iso alone increased U/L from 3.23 +/- 0.47 to 5.49 +/- 0.85 (P less than 0.025). The height of phase IV in expired 133Xe vs. volume plots correlated with U/L, being greater after Iso and smaller after Mech in each subject. The difference in RVr between upper and lower lung regions decreased after Mech in four out of five subjects from 0.22 TLC to 0.11 TLC. Iso alone did not change the gradient of RVr. The results are consistent with the concept that increased bronchomotor tone widens the range of critical opening and closing pressures with a more patchy and extensive distribution of airway closure.

Adult↗
PubMed1976

Age and sex differences in lung elasticity, and in closing capacity in nonsmokers.

Static volume-pressure characteristics of the human lung, closing capacity (CC), closing pressure, and subdivisions of lung volumes were measured in 66 adult nonsmokers, aged 24-58 yr. There were systemic differences between the sexes as well as with age. Young females had less elastic recoil at any lung volume than young males. However, males lost elastic recoil with age faster than females so that in the older age groups the recoil was similar. There were no significant changes in compliance over the volume range containing most values of CC in either males or females. By comparing the age regression of CC and of elastic recoil pressures at 40 and 50% TLC we conclude that the increase in CC with age in males was attributable almost entirely to loss of recoil. In females none of the increase in closing capacity with age was attributable to loss of recoil. By exclusion, it is probably attributable to a change in the intrinsic properties of small airways or an increase in the pleural pressure gradient with age.

Adult↗
PubMed1976

Influence of posture on flow dependence of distribution of inhaled 133Xe boli.

The second 100 ml of gas inspired at constant flow rates (V) from 0.1 to 2.5 l/s was tagged with 133Xe to determine the apicobasal bolus distribution ratio (VAlvA/VAlvB) for seven normal subjects in both the upright and supine postures. Gas was preferentially distributed to the base at low V. As V increased, redistribution to the apex occurred but was greater in the supine posture. As apicobasal time constant differences should be minimal in the supine posture, the greater flow dependence of bolus distribution suggests that the pressure swing was greater over apical zones than basal zones. Model studies indicate that the pressure differences (deltaPd) necessary to predict the measured VAlvA/VAlvB at all flow rates are less than 1.0 cmH2O. Such sensitivity of gas distribution to deltaPd at both low and high flow rates makes it appear relatively insensitive to regional compliance and resistance.

Adult↗
PubMed1976

Classification of bronchial lymphocytes from nonsmokers and smokers.

The population of lymphocytes obtained by endobronchial lavage is significantly different from the distribution of lymphocytes in the peripheral blood. Both B and T lymphocytes are found in fluids lavaged from the normal human lung. Of the lymphocytes that can be classified, the T cell population is larger than the B cell population in both nonsmokers and cigarette smokers, whereas a further increment in T cells is noted in smokers. A third population of unclassified lymphocytes, the "null" cells, also comprise a large portion of the lymphocyte population in both smokers and nonsmokers. Their significance has yet to be determined.

Adult↗
PubMed1976

Bacteremic Acinetobacter Herellea pneumonia with survival: case report.

A case of community-acquired pneumonia with Acinetobacter calcoacetium var. anitratus (Herellea vaginicola) is presented. Initial leukopenia and spare leukocytes in the sputum, followed by prolonged leukocytosis and fever, were unusual features of this case. The clinical significance and current antimicrobial drug therapy of acinetobacter infections are discussed.

Acinetobacter↗
PubMed1975

Reversibility of pulmonary function abnormalities in smokers. A prospective study of early diagnostic tests of small airways disease.

A prospective study of the reversibility of pulmonary function abnormalities in cigarette smokers was performed. Base line studies of 50 otherwise healthy cigarett smokers included lung volumes, static volume-pressure curves, closing volume, slope of phase III and maximum expiratory flow-volume curves while the subjects breathed air and while they breathed an 80 per cent helium-20 per cent oxygen mixture (He). Ten subjects, seven women and three men, ages 29 to 61, were restudied 6 to 14 weeks after they had stopped smoking. Two of these people had an abnormal closing volume, four had an abnormal slope of phase III and five had an abnormal response to helium. Static volume-pressure curves, slope of phase III and airflow rates were not improved on the repeat studies. There was increases in maximum expiratory flow rates with He at 50 and 25 per cent of vital capacity, reductions in the lung volume at which the maximum expiratory flow rate of air and He became identical, and decreases in closing volume. These reversible functional changes in smokers are thought to indicate improvement of peripheral airways obstruction.

Adult↗
PubMed1975

Voluntary changes of thoracoabdominal shape and regional lung volumes in humans.

We measured regional lung volumes from apex to base in humans during changes in thoracoabdominal shape which we monitored with magnetometers. In erect subjects, voluntary changes of shape at FRC did not change regional volume distribution. In supine subjects, the effect of negative pressure applied to the abdomen and a similar thoracoabdominal configuration achieved by voluntary means were studied. The distribution of regional volumes in both situations was the same as that measured during relaxation at the same overall lung volumes. We concluded that neither voluntary changes in shape nor negative abdominal pressure influenced the human pleural pressure gradient. This result, which differed from findings in animals, was probably because the human chest was relatively stiff and behaved with one degree of freedom; all parts of the human rib cage changed dimensions proportionally while negative abdominal pressure distorted the rib cage of animals.

Abdomen↗
PubMed1975

The early detection of airway obstruction.

To assess the sensitivity of tests for early, small airway obstruction, we selected 52 cigarette smokers with a ratio of 1-sec forced expiratory volume to forced vital capacity greater than 70 per cent from a smoking cessation clinic. From these subjects, 29 of the 46 tested demonstrated frequency dependence of dynamic compliance, a finding arbitrarily defined as indicative of small airway obstruction in this group. Dynamic compliance was correlated with the British Medical Research Council questionnaire, routine pulmonary function tests, closing volume as a per cent of vital capacity, maximal expiratory flow-volume curves, and flow dependence of distribution of inhaled boluses of xenon-133 (finite difference Xe). Symptoms of respiratory disease, and abnormal flow-volume curves, specific conductances, and ratios of residual volume to total lung capacity were also present in some subjects, but they correlated very poorly with frequency dependence of dynamic compliance. On the other hand, finite difference Xe was abnormal in 85 per cent of cases with frequency dependence of compliance and closing volume was abnormal in 70 per cent. In 8 of 12 subjects restudied 2 months after they stopped smoking, dynamic compliance was less frequency dependent than before smoking cessation. Similar improvements were noted in finite difference Xe, but closing volume was unchanged. Although closing volume and dynamic compliance tended to be abnormal in the same subject, concordance was not excellent, and the effects of smoking cessation suggested that the 2 tests had different determinants.

Adult↗
PubMed1975

Appraisal of a new test: Between-technician variation in the measurement of closing volume.

To determine the between-technician variation in the measurement of closing volume, 24 subjects were divided into 3 blocks of 8 subjects each. Each block was then tested by a pair of technicians. Each of the 3 technicians involved in the study tested 16 subjects. It was later necessary to reject the tracings of 2 subjects in one of the 3 blocks, leaving 22 for analysis. The N2 method of determining closing volume was used. The statistical analysis was performed separately on the following measures derived from the tracings: expired vital capacity, planimetry of the area under the curve, total lung capacity, closing volume as a per cent of expired vital capacity, and closing capacity as a per cent of total lung capacity. All tracings were assessed by each technician. Two separate analyses of variance were then carried out to determine, respectively, the components of variance in the administration of the test and in the interpretation of the tracings. Because different persons were able to administer the test the same way, it seems that closing volume poses no problem in administration, provided that instructions as to how to perform the test are closely followed. In the interpretation of the tracings, significant differences were found for all measures, except planimetry; however, not all of these have the same practical implications. Some tracings were found "difficult" to interpret and contributed more to the over-all variation than did others. When making use of a new test in a population study, the between-technician variation should be determined before the study is begun.

Humans↗