Showing papers in "The American review of respiratory disease in 1981"
TL;DR: The results suggested that natural exposure to this dust allergen allows occasional fecal particles to enter the lungs and that these particles contain very concentrated allerGEN.
Abstract: Using an inhibition radioimmunoassay for the major allergen from Dermatophagoides pteronyssinus (antigen P1), we studied the distribution of this dust allergen in the houses of patients with asthma. Both bed and floor dust samples contained a wide range of antigen P1, 100 to 100,000 ng/g of fine dust, and this concentration correlated well with the number of mite bodies (r = 0.81, p less than 0.001). We were unable to detect antigen P1 in the air of undisturbed rooms. However, during domestic activity, between 1 and 30 ng were collected on a filter than sampled air for 45 min at 17 L/min. Using a cascade impactor it was shown that greater than 80% of the airborne antigen P1 was associated with particles greater than 10 mu in diameter. Some of the particles containing allergen could be identified because they formed precipitin rings when impacted onto agarose containing rabbit antimite antiserum. These particles had the physical appearance of mite feces, which are the major source of antigen P1 in mite cultures. The results suggested that natural exposure to this dust allergen allows occasional fecal particles to enter the lungs and that these particles contain very concentrated allergen.
295 citations
TL;DR: It is concluded that physiologic and bronchoalveolar lavage data allow predictions of responsiveness to treatment and prognosis that are of practical value to clinicians.
Abstract: A minority of patients with cryptogenic fibrosing alveolitis (idiopathic pulmonary fibrosis) respond to treatment with corticosteroids. The purpose of this study was to identify factors other than histologic features that relate to responsiveness and prognosis. An analysis of 120 patients on whom data were prospectively collected is reported. The relationships between pulmonary function measurements, differential cell counts on bronchoalveolar lavage fluid, physiologic response to treatment, and survival are discussed. Patients responding to treatment with corticosteroids or immunosuppressive drugs had more severe initial impairment of the FVC (p less than 0.0001) and a more recent onset of disease (p less than 0.001). Lavage cell counts showed that increased proportions of lymphocytes were associated with responsiveness to corticosteroids and good prognosis (p less than 0.001), whereas increased eosinophils or increased neutrophils without increased lymphocytes were associated with failure to respond (p less than 0.025), and increased eosinophils were associated with a greater likelihood or progressive deterioration (p less than 0.05). Life table comparisons of survival in different groups showed improved survival in patients responding to treatment (p less than 0.05). Among nonresponders, those with more severe impairment of the FVC had shorter survival (p less than 0.05). We concluded that physiologic and bronchoalveolar lavage data allow predictions of responsiveness to treatment and prognosis that are of practical value to clinicians.
246 citations
TL;DR: The results of this study indicated that the marasmic type of protein calorie malnutrition is a common finding among patients with COPD, and that patients with CopD who are immunoincompetent may be more susceptible to mixed protein calories malnutrition of the kwashiorkor-marasmus type.
Abstract: The nutritional status of 38 patients with chronic obstructive pulmonary disease (COPD) was assessed by dietary intake, anthropometric measurements biochemical analysis, and immunologic testing. The mean intakes for 9 nutrients were significantly greater than the 1974 Recommended Dietary Allowances of the National Academy of Sciences. Results of the anthropometric measurements for usual weight for height, fat stores, and muscle mass were significantly less than standard. Of the 32 subjects evaluated for immunocompetence, 9 were anergic (induration, 0) on all 3 skin tests. The results of this study indicated that the marasmic type of protein calorie malnutrition is a common finding among patients with COPD, and that patients with COPD who are immunoincompetent may be more susceptible to mixed protein calorie malnutrition of the kwashiorkor-marasmus type.
220 citations
TL;DR: The results indicated that the bronchial response to inhaled histamine can be measured as reliably using a nebulizer and tidal breathing as by a more complex dose-metering device.
Abstract: Comparison of methods of aerosol generation and inhalation is required to improve standardization of inhalation provocation tests. We compared two widely used methods in 10 asthmatics, by measuring the dose and distribution of radiolabeled aerosol deposited in the throat and lung, and the provocation concentration of inhaled histamine required to reduce the FEV1 by 20% (PC20). In one method, aerosol was generated by a DeVilbiss 646 nebulizer attached to a dosimeter, and was inhaled by 5 inspiratory capacity breaths. The measurements with each method were repeated once to determine the reproducibility of results. Both methods deposited the same dose in the lung, but the distribution of the dose was different; the dosimeter method deposited more aerosol in the throat and central airways. The PC20 obtained with each method was the same. The reproducibility of all measurements in the same subject was similar. The lung dose deposited by each method in different subjects varied to the same degree. The results indicated that the bronchial response to inhaled histamine can be measured as reliably using a nebulizer and tidal breathing as by a more complex dose-metering device. They also suggested that, when the methods are regulated as described, the PC20 will have the same clinical significance.
220 citations
TL;DR: It is concluded that apneas, sleep arousals and awakenings, and loss of deep sleep occur during nasal obstruction and may explain complaints of poor sleep quality during URI.
Abstract: Anecdotal observations suggested that poor quality of sleep is a frequent complaint during upper respiratory infections (URI). Nasal obstruction occurs frequently during URI and causes sleep apnea in some infants. Sleep apnea disrupts normal sleep and could explain the complaints of poor sleep quality during URI in adults. Accordingly, 10 normal men had full night recordings of sleep stages and breathing rhythm before and during nasal obstruction. The order of obstructed and nonobstructed nights was randomized after a standard acclimatization night. During nasal obstruction, time spent in the deep sleep stages decreased from 90 +/- 11.2 (SEM) to 71 +/- 12.9 min (p less than 0.05), whereas significantly more time was spent in Stage 1 sleep (p less than 0.03). This loss of deep sleep during obstruction was associated with a twofold increase in sleep arousals and awakening (p less than 0.01) resulting from an increased (p less than 0.02) number of apneas (34 +/-19 during control sleep versus 86 +/- 34 during obstructed sleep). Apneas of 20 to 39 s in duration became 2.5 times more frequent (p less than 0.05) during obstruction. Oxygen saturation was studied in the last 4 subjects using an ear oximeter. Desaturation (SaO2 less than 90%) occurred 27 times during control sleep compared with 255 times during obstructed sleep. These desaturation episodes occurred only during apneas. All men complained of poor sleep quality during nasal obstruction. We concluded that apneas, sleep arousals and awakenings, and loss of deep sleep occur during nasal obstruction and may explain complaints of poor sleep quality during URI.
215 citations
TL;DR: It was found that ventilatory responses to both hypercapnia and hypoxia were reduced in the elderly by approximately 50%.
Abstract: Studies were performed to examine the decrease in ventilatory response to hypoxia and hypercapnia in the elderly and to explore its etiology. For this purpose, matched groups of normal elderly (65 to 79 yr of age) and young subjects were used. Standard pulmonary function tests were supplemented in both groups by determination of total respiratory compliance and the ventilatory responses to hyperoxic hypercapnia and isocapnic hypoxia using rebreathing methods. While testing the ventilatory responses, we recorded minute ventilation and its components, as well as mouth occlusion pressures, and rib cage and abdominal-diaphragmatic compartmental ventilation (magnetometry). We found that ventilatory responses to both hypercapnia and hypoxia were reduced in the elderly by approximately 50%. These reductions were not related to any change in control of respiratory timing, but to a large reduction in mean inspiratory airflow. The reduced airflow could not be attributed to alterations in pulmonary mechanics since the differences in mechanics between the groups were small. Instead, since the occlusion pressure responses to hypercapnia and hypoxia were reduced in the elderly proportionately to the ventilatory responses, reduction in neuromuscular inspiratory output was likely to be the major factor.
214 citations
TL;DR: The results supported the possibility that PMN may be involved in the pathogenesis of pulmonary oxygen toxicity and suggested that a close temporal relationship exists between the generation of high concentrations of chemoattractants in lung lavage, PMN influx into lung lavages, and death of rats exposed to hyperoxia.
Abstract: Although the pathogenesis off pulmonary oxygen toxicity is not fully understood, the fact that increased numbers of polymorphonuclear leukocytes (PMN) are found in the lung and that these increases coincide with the massive endothelial damage raises the possibility that PMN may contribute to lung injury caused by hyperoxia. In order to begin to elucidate a mechanism for this influx of PMN, we measured the chemoattractant activity for PMN of lung lavages of rats exposed to > 95% oxygen for various durations. We found that the chemoattractant activity of the lavages of the lungs of rats exposed to hyperoxia for 66 h was markedly increased (9.66 ±1.0 times greater) compared with activities in lavages of normoxic control rats. Furthermore, these increases in chemoattractant activity in lung lavages correlated well with increases in the number of PMN (7 times greater than that in normoxic control animals) in the alveolar lavages that occurred after the rats had been exposed to hyperoxia for 66 h. These increas...
212 citations
TL;DR: The potential importance of enhanced O2 release by AM from cigarette smokers was confirmed by demonstrating that lysis of fibroblasts induced by AMFrom smokers was completely prevented by addition of SOD and catalase.
Abstract: Superoxide anion (O2) release by alveolar macrophages (AM) from young asymptomatic cigarette smokers was greater than that by AM from age-matched nonsmokers. Greater O2 release by AM from cigarette smokers was observed before and after stimulation by bacteria or phorbol myristate acetate (PMA). In contrast, oxygen uptake and glucose (1(-14)C) oxidation by unstimulated or stimulated AM from cigarette smokers was the same as that by AM from non-smokers. The selective increase of O2 release by AM from cigarette smokers was not due to a lack of O2 scavenging agent within the cells, since intracellular superoxide dismutase (SOD) was increased in AM from smokers. The potential importance of enhanced O2 release by AM from cigarette smokers was confirmed by demonstrating that lysis of fibroblasts induced by AM from smokers was completely prevented by addition of SOD and catalase.
206 citations
TL;DR: It is concluded that the spacer devices may have a role to play in aerosol therapy by increasing drug availability to the lung, while at the same time decreasing unwanted drug deposition in the oropharynx.
Abstract: Only a small fraction of the dose from a pressurized aerosol inhaler reaches the lung, because most is deposited on the upper airways by inertial impaction. We have investigated the effects on aerosol deposition of two spacer devices (a 10-cm tube and a 22-cm cone) by incorporating teflon particles (mass median aerodynamic diameter, 3.2 micrometer) labeled with 99mTc into pressurized canisters. Ten subjects with obstructive airway disease inhaled the aerosol in a controlled manner from a conventional actuator alone or in combination with the tube or the cone. Radioaerosol distribution was measured using a shadowshield whole body counter. Deposition on the conducting airways was significantly improved by both spacers, but alveolar deposition was unchanged. Initial oropharyngeal deposition was reduced by both spacers in all 10 patients. We conclude that the spacer devices may have a role to play in aerosol therapy by increasing drug availability to the lung, while at the same time decreasing unwanted drug deposition in the oropharynx.
200 citations
TL;DR: The data suggested that smoking leads, directly or indirectly, to an increase in serum IgE and that this excess IgE may be qualitatively different from that seen in nonsmokers, at least after 35 yr of age.
Abstract: Data from adults enrolled in a general population study in Tucson, Arizona, indicated that smokers have higher serum IgE concentrations than nonsmokers, despite a lower rate of allergy skin test reactivity, at least after 35 yr of age. After 15 yr of age there was a significant decline in serum IgE with age in both allergy skin test positive and skin test negative nonsmokers but no significant age decline was noted in similar groups of smokers. Ex-smokers showed a decline in serum IgE concentrations since quitting cigarettes. Also, the marked increase in geometric mean IgE that was seen in nonsmokers during the spring was not observed in smokers. The data suggested that smoking leads, directly or indirectly, to an increase in serum IgE and that this excess IgE may be qualitatively different from that seen in nonsmokers. Possible mechanisms for the effect are discussed. The observations raised the possibility that some of the adverse health effects of smoking might be immunologically mediated.
196 citations
TL;DR: It is concluded that nasal PD can be accurately measured in vivo in humans, and that measurements of nasal bioelectric properties may serve as a relatively noninvasive index of respiratory epithelial function.
Abstract: Nasal transepithelial electrical potential difference (PD) was estimated in vivo in normal human subjects. The PD between a bridge perfused with Ringer's solution placed on the nasal mucosal surface and a reference electrode in a subcutaneous space was recorded. The magnitude of the PD depended upon the region of the nasal cavity touched by the exploring bridge. The PD values ranged from -4 mV (lumen negative) on the anterior tip of the inferior turbinate to approximately -30 mV on the inferior surface of the turbinate. Biopsies of the anterior turbinate were characterized by squamous epithelial cells, whereas ciliated cells dominated the epithelium from regions of higher PD. Epithelial abrasion abolished PD. No differences in PD were noted between the left and right nasal cavities, and repetitive measurements of PD at the same site yielded comparable values. No differences in nasal PD were noted between young male or female subjects but PD declined as a function of age. Amiloride (10(-4)M) and lidocaine (10(-1)M) reduced PD (-59% and -30%, respectively), whereas amphotericin B (5 X 10(-5)M) raised PD (+29%). We concluded that nasal PD can be accurately measured in vivo in humans, and that measurements of nasal bioelectric properties may serve as a relatively noninvasive index of respiratory epithelial function.
TL;DR: Through newly placed flow-directed pulmonary artery catheters (Swan-Ganz), bedside balloon occlusion angiography is used to assess the frequency of intravascular occlusive disease in patients with chronic obstructive pulmonary disease.
Abstract: Through newly placed flow-directed pulmonary artery catheters (Swan-Ganz), we used bedside balloon occlusion angiography to assess the frequency of intravascular occlusive disease in patients suffe...
TL;DR: In this article, the authors measured the pulmonary function of patients with spinal cord injury within 1 week, 3 weeks, 5 weeks, 3 months, and 5 months of the injury and found that a significant increase in vital capacity occurred within 5 weeks after the injury with an approximate doubling of vital capacity 3 months after injury.
Abstract: Measurements of pulmonary function were made on patients within 1 wk, 3 wk, 5 wk, 3 months, and 5 months of spinal cord injury. In patients with functionally complete transection of the cord between segment C5 and C6, the vital capacity was 30% of predicted in the first week after injury. Patients with injuries at C4 had smaller vital capacities. A significant increase in vital capacity occurred within 5 wk of injury with an approximate doubling of vital capacity 3 months after injury. Expiratory flow rates were directly dependent upon vital capacity. There was a high incidence of arterial hypoxemia, in the acute stage, even in patients with adequate ventilatory ability and normocarbia.
TL;DR: There was a strong correlation of 67Ga uptake and the number of lymphocytes and T-lymphocytes recovered from the lungs of these patients by bronchoalveolar lavage, which suggested that gallium uptake reflects the intensity of the T-LYmphocytes mediated component of the alveolitis in sarcoidosis.
Abstract: Current concepts of the pathogenesis of sarcoidosis suggest that the alveolitis of this disorder is related to increased numbers of mononuclear phagocytes and activated T-lymphocytes within the lung. To determine if 67Ga scanning, a procedure commonly used in the evaluation of inflammation, would be useful in staging the alveolitis of sarcoidosis, we studied 41 patients with this disorder and correlated estimates of pulmonary 67Ga accumulation with clinical, roentgenographic, physiologic, and bronchoalveolar lavage studies in these patients. Although 65% of patients with sarcoidosis showed increased amounts of 67Ga accumulation in the lung compared with control subjects, only weak correlations (r less than +/- 0.42, all comparisons) were found between the degree of gallium uptake and the clinical, roentgenographic, or physiologic data. In contrast, there was a strong correlation of 67Ga uptake and the number of lymphocytes and T-lymphocytes recovered from the lungs of these patients by bronchoalveolar lavage (p less than 0.0001, r greater than or equal to 0.67, both comparisons). This data suggested that gallium uptake reflects the intensity of the T-lymphocytes mediated component of the alveolitis in sarcoidosis. Because 67Ga scans are noninvasive, simple to perform, and widely available, they should prove useful to stage the activity of sarcoidosis and to make decisions regarding therapy directed against the alveolitis of the disease.
TL;DR: It is suggested that these arachidonic acid cyclooxygenase metabolites generated in such sufficient quantities that they may function in important aspects of the modulation of hypersensitivity responses in human lungs.
Abstract: Antigen challenge of passively sensitized chopped human lung resulted in the generation of several arachidonic acid cyclooxygenase metabolites (AACM): thromboxane A2 (TxA2) as measured by its stable metabolite TxB2, prostaglandin D2 (PgD2), prostacyclin (PgI2) as measured by its stable metabolite 6-keto-PgF1α, prostaglandin F20 (PgF2α), and prostaglandin E (PgE). The kinetics of AACM release after antigen challenge paralleled histamine release. All AACM were released in an antigen dose-dependent manner and reached maximal release at antigen concentrations lower than those required for maximal histamine release. Quantitatively, of the AACM measured, PgD2 and PgI2 were found to predominate in anaphylactic reactions of human lung parenchyma. Generation of PgD2 and PgI2 were 3- to 7-fold greater than that of other AACM measured. Thromboxane B2 was generated in quantities comparable to PgE and PgF2α. Studies were designed to test the hypothesis that lung smooth muscle contraction per se can account for the gen...
TL;DR: Two-dimensional polyacrylamide gel electropherograms suggested, and radial immunodiffusion assays confirmed, that the soluble proteins of the bronchoalveolar surface resemble serum in kind and amount with the following significant exceptions.
Abstract: Plasma proteins were measured in bronchoalveolar lavage effluents and serums from normal healthy nonsmokers and smokers, and their concentrations in the 2 fluids were compared. Two-dimensional Polyacrylamide gel electropherograms suggested, and radial immunodiffusion assays confirmed, that the soluble proteins of the bronchoalveolar surface resemble serum in kind and amount with the following significant exceptions. Two immunoglobulins, IgG and IgA, were present in amounts that exceeded their concentrations in serum; of the 2, IgG was more abundant. Large nonimmunoglobulin proteins (> 300,000 daltons) were absent or present at very low concentrations compared with the amounts found in serum. Transferrin was the only nonimmunoglobulin with a concentration significantly higher at the bronchoalveolar surface than in serum. Smoking did not cause a significant change in the concentration of any protein in serum, but did cause an increase in IgG, C4, and C3 and a decrease in alpha2-thioglycoprotein, alpha1-acid...
TL;DR: It is suggested that exercise increases the bronchoconstriction produced by a given concentration of SO2 in subjects with asthma by increasing the minute volume of ventilation and that the delay in bronchconstriction after exercise is due to the large tidal volumes that persist for some minutes during recovery.
Abstract: We undertook a study to determine whether moderate exercise modifies the bronchoconstriction produced by sulfur dioxide (SO2) in subjects with mild asthma. In 7 subjects, we compared the changes in specific airway resistance (SRaw) produced by 10 min of exercise alone (400 kpm/min on a cycle ergometer), inhalation of SO2 alone, and the combination of exercise and SO2. During all studies, a subject breathed SO2 and/or air from a mouthpiece. In 6 additional subjects, we compared the increase in SRaw produced by inhalation of SO2 during exercise with that produced by eucapnic hyperventilation with SO2. Neither inhalation of 0.05 ppm of SO2 at rest nor exercise or hyperventilation alone had any effect on SRaw. Inhalation of SO2 during exercise, however, significantly increased SRaw (from 8.46 +/- 3.58 L x cm H2O/L/s (mean +/- SD) to 18.16 +/- 10.05 at 0.05 ppm and from 8.07 +/- 2.69 to 10.48 +/- 4.49 at 0.25 ppm (p less than 0.05)). In the 2 most responsive subjects, inhalation of 0.10 ppm of SO2 during exercise also significantly increased SRaw. The SRaw increased by the same amount whether SO2 was inhaled during exercise or during eucapnic hyperventilation at the same minute ventilation, but the time course of the increase in SRaw was different. The SRaw was at or near maximal values at the first measurement (30 s) after hyperventilation but not until 2 to 4 min after exercise. When 4 subjects took larger breaths after inhaling SO2 during eucapnic hyperventilation to more closely match the volume of the breaths taken after exercise, the time courses of SO2-induced bronchoconstriction after hyperventilation and after exercise were nearly identical. These results suggested that exercise increases the bronchoconstriction produced by a given concentration of SO2 in subjects with asthma by increasing the minute volume of ventilation and that the delay in bronchoconstriction after exercise is due to the large tidal volumes that persist for some minutes during recovery.
TL;DR: By restricting the reference frame to alveolar septal tissue, surface and volume estimates agree well in most cases with instillation-fixed lungs, although caution is nevertheless indicated in interpreting such comparisons because differing fixation/inflation techniques generate unequal osmotic and oncotic pressure gradients.
Abstract: Four normal rat lungs were positive-pressure inflated (7 mm Hg downslope) and perfusion-fixed for electron microscopy. Morphometric analysis yielded estimates for compartmental volume densities in alveolar septal lung tissue excluding capillaries: type I cells, 0.126; type II cells, 0.097; endothelium, 0.264; interstitial cells, 0.358; interstitial space, 0.116; macrophages, 0.039. Numerically, the largest cell population of the parenchymal tissue was the endothelial cells (43%) followed by interstitial (31.8%), type II (14.5%), and type I (7.5%) epithelial cells; 3.2% were macrophages. Individual type I cells possessed the largest cell volume (915 micron3) as well as th largest luminal surface (4,518 micron3), covering 97.5% of the alveolar surface. Type II cells (volume, 366 micron3; surface, 62 micron2) line only 2.5% of the alveolus. Total endothelial surface is 16% larger than the alveolar surface, although individual endothelial cells are much smaller (volume, 336 micron3; luminal surface, 946 micron 2) than type I cells. Macrophages and interstitial cells (cell volume, 665 and 615 micron3, respectively) are of an intermediate size. By restricting the reference frame to alveolar septal tissue, surface and volume estimates agree well in most cases with instillation-fixed lungs. Caution is nevertheless indicated in interpreting such comparisons because differing fixation/inflation techniques generate unequal osmotic and oncotic pressure gradients.
TL;DR: It is concluded that juxtacardiac pressure increases markedly as the lungs distend, even in an open-chest preparation, and that preload reduction on this basis, not ventricular impairment, best explains diminished cardiac output during ventilation with PEEP.
Abstract: To investigate the contribution of local mechanical factors to the alteration in ventricular function that occurs during ventilation with positive end-expiratory pressure (PEEP), the hemodynamic effects of increasing end-expiratory pressure with both lungs ventilated, and with the upper lobes, lower lobes, right and left lungs selectively ventilated, were examined in 20 anesthetized open-chest dogs. The rise in pressure between the lungs and heart exceeded that of the ipsilateral atrium. Increasing PEEP with both lungs ventilated caused atrial and mediastinal (juxtacardiac) pressures to increase and stroke volume to decrease more than with ventilation of smaller lung volumes. Patterns causing distention of lung tissue adjacent to the right heart were associated with the greatest decrease of stroke volume. Decreasing stroke volume related more closely to increasing right atrial than to left atrial pressure. We concluded that juxtacardiac pressure increases markedly as the lungs distend, even in an open-chest preparation, and that preload reduction on this basis, not ventricular impairment, best explains diminished cardiac output during ventilation with PEEP.
TL;DR: An increasing progression of lung function loss with advancing age in males and females in all smoking categories is revealed, and improvement in lung function after cessation of smoking is suggested.
Abstract: In a cross-sectional survey of 3 separate communities, we studied the white residents 7 year of age and older in order to determine the relation between cigarette smoking and lung function. We identified 2,817 nonsmokers, 664 ex-smokers, and 1,209 smokers who were further classified as light smokers (1 to 20 cigarettes per day) and heavy smokers (greater than 20 cigarettes per day). Residual lung function (observed-predicted) was examined in these groups for forced expiratory volume in one second (rFEV1) and for maximal expiratory flow rates at 50% and 25% of the vital capacity (rVmax50% and rVmax 25%). Mean residuals by sex, age, and smoking category were compared and revealed an increasing progression of lung function loss with advancing age in males and females in all smoking categories. These age-related trends were due primarily to the amount smoked by persons in each group. The age of onset of these abnormalities was found to be as early as the age group 15 to 24 yr. Abnormalities were greater in smokers than ex-smokers, even when the amount smoked was taken into account. This is suggested improvement in lung function after cessation of smoking. Men and women were found to experience the same relative degree of gain. Also, the contribution of the various smoking habits to lung function loss was assessed using regression analyses and accounted for no more than 15% of the variation of the residual lung function. Combinations of variables were found to explain only slightly more variation than a single variable. The two most important variables were duration of smoking and pack-years. Inhalation and use of filters were not significant. Although the same amount of variation explained by the smoking variables after accounting for age, height, weight, and sex was small, this variation accounted for almost all of the decrease, over age, in residual lung function for smokers and ex-smokers.
TL;DR: The predominant radiographic presentation of lung diseases caused by M. xenopi was a nodular or mass shadow, but cavitary disease and multiple nodular densities were also frequently observed and disease was successfully treated with standard antituberculosis drugs.
Abstract: We describe 19 cases of pulmonary disease due to Mycobacterium xenopi, a nosocomial infection related to the hospital water system. Pre-existing lung disease and prolonged environmental exposure during previous hospitalizations were apparent predisposing factors. Twelve patients had respiratory symptoms, including three with hemoptysis, at the time an abnormal chest roentgenogram was obtained. The predominant radiographic presentation of lung diseases caused by M. xenopi was a nodular or mass shadow, but cavitary disease and multiple nodular densities were also frequently observed. One subject had a solitary pulmonary nodule, and surgical resection was performed. In 12 patients who were skin tested with both M. xenopi sensitin and PPD-tuberculin, induration was consistently greater with M. xenopi. Initial isolates of M. xenopi were uniformly sensitive in vitro to 2.0 microgram of streptomycin, 1.0 microgram of isoniazid, and 10.0 microgram of para-aminosalicylic acid. In general, disease due to M. xenopi was successfully treated with standard antituberculosis drugs.
TL;DR: The view that the special part of the bacterial population that is killed more rapidly by rifampin than by isoniazid during short-course chemotherapy consists of bacilli dormant much of the time but occasionally metabolising for short periods.
Abstract: Model systems were set up in vitro to explore the reasons why rifampin is a better sterilizing drug than isoniazid in short-course chemotherapy of tuberculosis. When the growth rate of Mycobacterium tuberculosis strain H37Rv was reduced uniformly by lowering the incubation temperature or the pH of the culture medium, the bactericidal activity of rifampin and isoniazid decreased to a similar extent. However, when a culture was maintained at 8 degrees C and incubated for daily periods of 1 or 6 h at 37 degrees C, rifampin killed more rapidly than isoniazid. Maintenance of control cultures without antimicrobials at 8 degrees C with or without periods at 37 degrees C, had little or no effect on their viability, ability to commence logarithmic growth at 37 degrees C, or to incorporate [14C]uridine. Old cultures left undisturbed or to which small additions of fresh culture medium were regularly added were killed more rapidly by rifampin than by isoniazid. These experiments supported the view that the special part of the bacterial population that is killed more rapidly by rifampin than by isoniazid during short-course chemotherapy consists of bacilli dormant much of the time but occasionally metabolising for short periods.
TL;DR: It is concluded that more sensitive subjects required more daily sequential exposures in order to adapt, but the duration of adaptation was shortest for the more sensitiveSubjects were studied for 125 min while they exercised intermittently.
Abstract: Repeated ozone exposure induces an adaptative response whereby subsequent ozone exposure induces little or no pulmonary function change. The time course of the adaptation and the persistence of this adaptation was determined in 24 subjects. Subjects were studied for 125 min while they exercised intermittently. They were exposed to filtered air for 1 day and then in the next week for 5 consecutive days to 0.5 ppm ozone. After the fifth day, subjects were randomly assigned to return for one more ozone exposure at 1, 2, or 3 wk. The greatest decrement in FEV1 occurred on the second day of exposure. The number of consecutive ozone exposures required to produce adaptation varied from 2 to 5 days. Persistence of adaptation in ozone-sensitive subjects (initial decrease in FEV1 greater than 10%) showed marked individual variability, but the duration of adaptation was shortest for the more sensitive subjects. Adaptation, on the average, lasted for less than 2 wk, being as short as 7 days and as long as 20 days. We concluded that more sensitive subjects required more daily sequential exposures in order to adapt.
TL;DR: In patients with small cell carcinoma whose disease is thoroughly staged and who are given aggressive chemotherapy, certain sites or a small number of sites of extensive disease may be treated as successfully as limited disease.
Abstract: The influence of various sites of distant metastases on response and survival was analyzed in 106 consecutive previously untreated patients with small cell carcinoma whose disease was systematicall...
TL;DR: In this article, 50 patients with either malignant (n = 25) or infectious/inflammatory chest lesions had lung aspirations using ultrathin needles, 24 to 25 gauge, and the procedure's overall sensitivity was...
Abstract: Fifty patients with either malignant (n = 25) or infectious/inflammatory (n = 25) chest lesions had lung aspirations using ultrathin needles, 24 to 25 gauge. The procedure's overall sensitivity was...
TL;DR: The results indicated that the genioglossus muscle behaves like a respiratory muscle and suggested that central control of upper airway and respiratory muscles in humans are intimately related.
Abstract: In order to define the relationship between central control of upper airway and respiratory muscle function, diaphragmatic electromyogram (EMGdi) and genioglossal EMG (EMGge) responses to isocapnic hypoxia were studied in 6 awake supine volunteers. Both EMGs were processed and quantitated as moving time average activity. In all subjects, EMGge showed phasic inspiratory activity synchronous with EMGdi. Increases seen in EMGdi and EMGge were linearly related to the decrease in oxygen saturation (r = 0.89 +/- 0.08 and 0.89 +/- 0.08, respectively). There was also a linear relationship between the relative responses of both EMGs to hypoxia such that a low EMGdi response was associated with a low EMGge response and vice versa (r = 0.92, p less than 0.001). These results indicated that the genioglossus muscle behaves like a respiratory muscle and suggested that central control of upper airway and respiratory muscles in humans are intimately related.
TL;DR: It is concluded that the use of PEEP in patients with acute pulmonary edema, to the degree used in this study, may depress cardiac output by simply decreasing left ventricular preload.
Abstract: We evaluated the effects of positive end-expiratory pressure (PEEP) on left ventricular function in 15 patients with acute respiratory insufficiency secondary to pulmonary edema with invasive (pres...
TL;DR: Cimetidine probably slowed theophylline elimination by relatively nonspecific inhibition of the hepatic microsomal mono-oxygenase system, which may produce clinically significant changes in serum theophyLLine concentrations.
Abstract: This study tested the hypothesis that cimetidine decreases theophylline clearance. Aminophylline (6 mg/kg) was administered intravenously both before and after cimetidine treatment in 5 healthy adults. Cimetidine (300 mg) was administered orally every 6 h for 2 days before and 18 h after the aminophylline dose. Plasma samples were collected before and for 24 h after each aminophylline dose, and theophylline concentrations were determined by an enzyme-mediated immunoassay technique. Cimetidine significantly decreased theophylline clearance, mean decrease, 39% (3.85 +/- 0.27 L/h control versus 2.34 +/- 0.23 L/h with cimetidine treatment, p less than 0.002). The apparent volume of distribution was unchanged (p greater than 0.5), whereas the elimination rate constant was significantly decreased by a mean of 42% (control, 0.091 +/- 0.013 h-1 versus 0.053 +/- 0.007 h-1 with cimetidine treatment, p less than 0.005). This corresponded to an average increase in elimination half-life of 73% (range, 50 to 97%). Cimetidine probably slowed theophylline elimination by relatively nonspecific inhibition of the hepatic microsomal mono-oxygenase system. This effect may produce clinically significant changes in serum theophylline concentrations.
TL;DR: Using bleomycin-induced pulmonary fibrosis as a model, collagen metabolism in the fibrotic process was studied using a technique based on the quantitation of the rate of release of hydroxyproline-containing peptides when lung homogenates were incubated in calcium-containing buffer, and lung collagenolytic activity was markedly diminished as a result ofBleomycin treatment.
Abstract: Using bleomycin-induced pulmonary fibrosis as a model, we have set out to study collagen metabolism in the fibrotic process As was previously shown, intratracheal administration of bleomycin in the rat caused increased deposition and net synthesis of collagen in the lung This was accompanied by marked increases in the tissue-free proline pool size and less dramatic increases in the pool's radioactivity when lung mince was pulsed with radioactive proline to measure the net collagen synthesis Using a technique based on the quantitation of the rate of release of hydroxyproline-containing peptides when lung homogenates were incubated in calcium-containing buffer, lung collagenolytic activity was markedly diminished as a result of bleomycin treatment Concomitant treatment with the steroid methylprednisolone did not affect significantly this decrease in lung collagenolytic activity Such steroid treatment, however, prevented the increase in bleomycin-induced lung collagen deposition and partially suppressed total lung collagen synthesis, without affecting the net rate of lung collagen synthesis expressed per mg of DNA Steroid treatment also inhibited the marked increase in tissue-free proline pool size and radioactivity caused by bleomycin The mechanism of amelioration of the fibrotic response by the steroid is discussed
TL;DR: Prevalence of antibodies to M. faeni was associated with dairy farming, larger farms, and larger dairy herds, and an additive effect of hay acreage and size of dairy herd was observed.
Abstract: The prevalence of farmer's lung disease and antibodies to farmer's lung antigens were studied in a probability sample of over 1,400 farmers in north central Wisconsin. The prevalence rate of farmer's lung disease was 4.2 per 1,000 farmers. The most prevalent antibody type was directed against Micropolyspora faeni, with 6% of the study population precipitin-positive. Prevalence of antibodies to M. faeni was associated with dairy farming, larger farms, and larger dairy herds. An additive effect of hay acreage and size of dairy herd was observed. An independent relationship was also observed for cigarette smoking, with antibodies to M. faeni more prevalent among nonsmokers.