Showing papers in "Lung in 1981"
TL;DR: Fifty children and adolescents with obstructive sleep apnea syndrome and related breathing disorders during sleep are reviewed; the most common presenting complaint was excessive daytime somnolence; hyperactivity and antisocial behavior also were cited frequently.
Abstract: Fifty children and adolescents with obstructive sleep apnea syndrome and related breathing disorders during sleep are reviewed. Subjects were subdivided according to whether their breathing irregularity was secondary to a medical problem (group I) or was the primary complaint (group II). The most common presenting complaint was excessive daytime somnolence; hyperactivity and antisocial behavior also were cited frequently. In 20% of cases, substantial personality changes were reported. Clinical symptoms included failure to thrive, abnormal weight for age, acute cardiac or cardiorespiratory failure, hypertension, and frequent upper airway infections. Continuous, heavy snoring was reported in all cases; disrupted nocturnal sleep, sleep walking, nightmares, and enuresis were common. All subjects, and 22 control patients, were monitored polygraphically during sleep for at least one night. Nocturnal sleep in the reported population was severely disrupted. A complete disappearance of stage 3 NREM sleep was noted in 86% of cases; REM sleep was decreased less. The management of these cases is reviewed. Eight patients received permanent tracheostomies. Thirty children had tonsillectomy and/or adenoidectomy (three later required tracheostomy). Non-surgical approaches also were used, particularly in group 1. Follow-up on these cases to date is presented.
439 citations
TL;DR: This review will focus on some aspects of the biochemistry and cell biology of irradiated lungs with two objects: to summarize developments which have occured in research in this area and to relate these, as far as possible to the clinical syndromes which follow therapeutic irradiation of the lungs.
Abstract: The damage which radiations produce in tissues such as the lungs can be discussed at the molecular, biophysical, biochemical, cellular, and organ levels. This review will focus on some aspects of the biochemistry and cell biology of irradiated lungs with two objects: firstly, to summarize developments which have occured in research in this area: and secondly to relate these, as far as possible to the clinical syndromes which follow therapeutic irradiation of the lungs. To a certain extent, also, I hope that radiation serves as a model for the large and growing number of agents which can damage the lungs and will provide insight into the ways in which the lung responds.
126 citations
TL;DR: A dimensional model of the pulmonary veins was elaborated and compared with a previously obtained model ofThe pulmonary arteries and the venous volume was calculated to be 74 ml, 80% of which is located in the upper six orders.
Abstract: Resin casts of the pulmonary veins were made from the lungs of two women and one man Branches were classified by Strahler orders, the number of branches in each order was counted, and their mean diameter and mean length determined All branches down to 10 mm diameter were studied on each of the casts, and a sample of branches down to 02 mm diameter was studied on one cast From the data thus obtained a dimensional model of the pulmonary veins was elaborated and compared with a previously obtained model of the pulmonary arteries The venous volume was calculated to be 74 ml, 80% of which is located in the upper six orders
78 citations
TL;DR: Recent evidence supports the idea that pulsus paradoxus is the result of two mechanisms, and negative pleural pressure surrounding the left ventricle is equivalent to an increase in aortic pressure and impedes emptying of the left Ventricle much like an increased in afterload.
Abstract: Spontaneous inspiration causes an increase in right ventricular stroke volume due to a transient increase in venous return. In contrast, spontaneous inspiration causes a fall in left ventricular stroke volume which is exaggerated in conditions of accentuated pleural pressure swings and pericardial disease. This is manifested by the clinical sign ofpulsus paradoxus. Recent evidence supports the idea thatpulsus paradoxus is the result of two mechanisms. First, negative pleural pressure surrounding the left ventricle is equivalent to an increase in aortic pressure and impedes emptying of the left ventricle much like an increase in afterload. Second, distention of the right ventricle due to the transient increase in venous return causes an elevation of left ventricular diastolic pressure due to ventricular interdependence and therefore impedes left ventricular filling. The mechanism of negative pleural pressure “afterload” is thought to be the major cause of pulsus paradoxus when pleural pressure swings are accentuated. Ventricular interdependence is thought to predominate when pericardial disease is present.
74 citations
TL;DR: The nonadrenergic inhibitorySystem in the lung is the only inhibitory system demonstrated in humans and other primates and the two most likely candidates as mediators of this system are ATP or a related nucleotide and vasoactive intestinal peptide.
Abstract: In conclusion the nonadrenergic inhibitory system in the lung is the only inhibitory system demonstrated in humans and other primates. In other animals there is often the addition of the adrenergic system or in the case of the dog there are only adrenergic inhibitory nerves. In the chicken the inhibitory system is dominant but in mammals it is secondary to the cholinergic system which overrides the inhibition. Defects of this system are known for the gastrointestinal tract in humans where this inhibitory system is vital for the functioning of peristalsis and for the relaxation of sphincters. It is possible that similar defects could exist in the lung where they might play a role in the pathogenesis of hyperreactive airways in asthma or obstructive pulmonary disease. At the present time the two most likely candidates as mediators of this system are ATP or a related nucleotide and vasoactive intestinal peptide. Much work needs to be done to determine the role of this system in the regulation of airways smooth muscle in normal and disease states.
66 citations
TL;DR: This review addresses salient features of lung development in a multidisciplinary fashion with emphasis on recent biochemical observations and their implications.
Abstract: Lung development requires carefully regulated coordination of anatomic, physiologic, and biochemical processes. The result of these maturational events must be an organ having an adequate surface area, sufficient vascularization, and the metabolic capability to sustain oxygenation and ventilation during the neonatal period. Recent investigative efforts have greatly increased our understanding of fetal lung maturation by defining the composition of lung surfactant, by documenting changes in the concentration of surfactant components throughout gestation, and by identifying the role of potential metabolic regulatory mechanisms governing lung phospholipid synthesis and turnover. Accordingly, this review addresses salient features of lung development in a multidisciplinary fashion with emphasis on recent biochemical observations and their implications.
40 citations
TL;DR: Cellular and humoral data obtained in normal sheep are described, which show the conscious sheep offers an excellent model for studying pulmonary functions, for obtaining transbronchial biopsies and for bronchoalveolar lavage.
Abstract: Fiberoptic bronchoscopy was used as a simple and well tolerated technique for segmental bronchoalveolar lavage and cytologic study in unsedated, unanesthetized sheep. In 20 healthy animals, repeated results of analyses (three times every two weeks) of selected humoral and cellular components of lung defense mechanisms are described. Yields of 1×107 free airway cells (FAC) per lavage were easily obtained with greater than 70% cells being macrophages and 10–15% lymphocytes. Phagocytosis by FAC was readily studied provided the animal basal temperature of 39° C was used during cell incubation. DNA synthetic activity of FAC was measured by mitogen stimulation assays and the effect of asbestos on this activity was evaluated. Prostaglandin synthesis and phospholipase A activity in FAC were assessed in similar circumstances. Total proteins, albumin and prostaglandin E2-like activity was also measured in the bronchoalveolar lavage (BAL) supernatant. No significant changes were seen after repeated bimonthly lavages. The conscious sheep offers an excellent model for studying pulmonary functions, for obtaining transbronchial biopsies and for bronchoalveolar lavage. Although the model was developed for future studies on lung defense mechanisms, this paper describes cellular and humoral data obtained in normal sheep.
26 citations
TL;DR: It would appear that the alveolar basement membrane cannot be isolated in a form comparable to ultrastructurally pure basement membranes such as that of the renal glomerulus.
Abstract: A cell-free alveolar extracellular matrix has been prepared from the lungs of several species of young and adult animals by a procedure consisting of extraction of parenchymal fragments with the detergents Triton X-100 and sodium deoxycholate. The isolated extracellular matrix preparations were ultrastructurally heterogeneous consisting of amorphous basement membranes and associated interstitial collagen and microfibrillar components as shown by histochemical staining and their electron microscopic appearance. The amino acid and carbohydrate compositions of these preparations had a collagenous nature which resembled in many respects that of some ultrastructurally pure basement membranes. Urea extraction of extracellular matrix from adult animals solubilized a distinctly less collagenous fraction which was particularly rich in the acidic amino acids, aspartic and glutamic acids, and had a chemical similarity to acidic structural glycoproteins. Extraction of adult samples with ureamercaptoethanol and pepsin digestion of the insolubilized residues gave more collagenous fractions. Our ultrastructural and chemical examination of these alveolar extracellular matrix preparations clearly indicate that they cannot properly be designated as pure alveolar basement membranes. These findings and the anatomical characteristics of the alveolar blood-air interface make it probable that preparations isolated by others using sonication procedures, with chemical characteristics similar to those reported here, were not ultrastructurally pure alveolar basement membranes as reported but were actually heterogeneous mixtures of basement membranes, interstitial collagens and microfibrils. It would appear that the alveolar basement membrane cannot be isolated in a form comparable to ultrastructurally pure basement membranes such as that of the renal glomerulus.
26 citations
TL;DR: It is suggested that a defect in the metabolism of prostacyclin could be an underlying cause of bronchospasm in those cases where histamine and/or prostaglandin F2a is involved as a pathogenetic factor.
Abstract: The responses of human isolated bronchial smooth muscle to electrical stimulation and to different drugs and substances were studied. Field stimulation produced an initial contraction followed by relaxation. In the presence of muscarinic receptor blockade electrical stimulation resulted primarily in relaxation which was partly due to noradrenaline and partly due to a nonadrenergic substance. Prostacyclin (10−7 to 10−6 M) relaxed and indomethacin enhanced the muscle tone. In addition it was found that indomethacin potentiated the effect of histamine. Prostacyclin was capable of relaxing the tissue which had been previously contracted by histamine or prostaglandin F2a
. It is suggested that a defect in the metabolism of prostacyclin could be an underlying cause of bronchospasm in those cases where histamine and/or prostaglandin F2a
is involved as a pathogenetic factor.
23 citations
TL;DR: Patients with severe asthma were randomized into three groups and treated double-blindly with either aminophylline, epinephrine, or a combination of these two for one hour and then with both drugs for an additional hour, finding no difference in FEV1 or PEFR among the three groups.
Abstract: Thirty-seven patients with severe asthma were randomized into three groups and treated double-blindly with either aminophylline, epinephrine, or a combination of these two for one hour and then with both drugs for an additional hour. All patients began with plasma theophylline levels less than 10 µg/ml and all achieved 17 µg/ml. Epinephrine produced 134% improvement in FEV1 in one hour compared to 38% improvement produced by aminophylline. Epinephrine and combination therapy produced the same amount of bronchodilatation in one hour. Patients whose initial PEFR was ≦100 l/min failed to improve with aminophylline alone. After two hours of treatment, there was no difference in FEV1 or PEFR among the three groups. Arrhythmias and vomiting occurred more frequently when aminophylline was used and these adverse responses did not correlate with plasma theophylline levels.
23 citations
TL;DR: The results suggest the existence of a subgroup of patients with bronchial hyperreactivity to inhaled histamine, which may reflect the individual location of the inflammatory process in patients with allergic bronchioloalveolitis.
Abstract: Eighty-two patients with farmer’s lung were given a bronchial challenge with histamine. In 22 of them, a positive reaction occurred during the acute phase of the disease. None of these subjects had asthma or chronic bronchitis. In 16 of the 20 positive reactors who were re-challenged the result was negative after 1–2 months. Our results suggest the existence of a subgroup of patients with bronchial hyperreactivity to inhaled histamine. This may reflect the individual location of the inflammatory process in patients with allergic bronchioloalveolitis.
TL;DR: Application of the recently discovered pathogenetic principles involved in exercise-induced bronchospasm has resulted in further insights into the pathophysiology and therapy of this condition.
Abstract: The weight of current evidence indicates that the initial reaction sequence by which exercise induces airway obstruction is heat loss from the respiratory tract with subsequent cooling of the airways. The critical variables which determine the magnitude of the response are the absolute level of ventilation, and the temperature and water content of the inspired air. Exercise per se is not essential, and serves only as the means to increase ventilation. Although the mechanism by which heat loss produces airway obstruction still remains to be determined, application of the recently discovered pathogenetic principles involved in exercise-induced bronchospasm has resulted in further insights into the pathophysiology and therapy of this condition.
TL;DR: The cellular, biochemical and immunologic characteristics of lavage fluid collected from 9 patients with bird fancier’s lung and from 4 asymptomatic pigeon breeders of whom 3 had positive serum precipitating antibodies were compared with clinical, biological and functional pulmonary responses after inhalation provocation tests.
Abstract: The cellular, biochemical and immunologic characteristics of lavage fluid collected from 9 patients with bird fancier’s lung and from 4 asymptomatic pigeon breeders of whom 3 had positive serum precipitating antibodies were compared with clinical, biological and functional pulmonary responses after inhalation provocation tests. In the symptomatic subjects, the lavage fluid consistently revealed a lymphocytosis (34% to 90%) with elevation of proteins and immunoglobulins G, A and M which varied with the severity of the disease. In 5 of 8 cases, precipitating antibodies to avian antigens were found. All 9 patients with fancier’s lung had a positive bronchial provocation test which was more intense in the acute stage of the disease. In the asymptomatic subjects there was no elevation in the percentage of alveolar fluid lymphocytes, and the bronchial provocation test induced no clinical, biological or functional changes.
TL;DR: This review attempts to synthesize the available and increasing evidence which supports the hypothesis that anaesthesia-induced alterations in chest wall behavior are responsible for the associated changes in lung function and consequent impairment of pulmonary gas exchange.
Abstract: This review examines the possible mechanisms for the impairment in pulmonary gas exchange and ventilatory control associated with general anaesthesia. Venous admixture and physiological dead space are both increased during anaesthesia. These changes result from increased ventilation-perfusion inequality, an effect apparently mainly attributable to alteration in the intrapulmonary distribution of ventilation. Concomitantly, with these changes in pulmonary gas exchange anaesthesia is known to alter the mechanics of the respiratory system and, in particular, to decrease functional residual capacity in recumbent subjects. Recent research has renewed interest in the finding that anaesthesia also alters chest wall shape and motion. This review attempts to synthesize the available and increasing evidence which supports the hypothesis that anaesthesia-induced alterations in chest wall behavior are responsible for the associated changes in lung function and consequent impairment of pulmonary gas exchange. Finally, the important finding that anaesthetic agents depress the ventilatory response to hypercapnia and hypoxia is discussed.
TL;DR: A bronchoscopic video-technical method to measure mucociliary clearance in vivo using 1-mm discs of polyethylene placed on the tracheal mucosa, which can easily be used in connection with routine bronchoscopy.
Abstract: We used a bronchoscopic video-technical method to measure mucociliary clearance in vivo. 1-mm discs of polyethylene were placed on the tracheal mucosa. Their cephalad movement was recorded on video-tape via a videocamera adapted to the bronchoscope optic, and the mucous transport velocity was estimated. In 10 dogs the reproducibility of this method was demonstrated by measuring the mucociliary clearance twice at an interval of 7 days. Measurements performed in 10 smokers and 7 nonsmokers showed differences between the two groups. In nonsmokers the mean mucous transport velocity cephalad in the trachea was 18.5 mm/min and in smokers 6.8 mm/min. Since each measurement took only a few minutes this method can easily be used in connection with routine bronchoscopy. The advantages and shortcomings of the method are discussed.
TL;DR: Clinical observations and experimental evidence suggest that decreased granulocyte number and function predispose to invasive aspergillus infection in diabetic ketoacidosis and the pattern of immunodeficiency in the diabetic host is consistent with these abnormalities in that granulocytes function is impaired in diabetic acidosis.
Abstract: We report a case of diabetic ketoacidosis associated with invasive aspergillosis and no other known immunodeficiency. Immunologic studies revealed normal serum immunoglobulins and normal absolute numbers of T and B lymphocytes. Mitogenic responses of peripheral blood lymphocytes to multiple antigens (PPD, PHA, Con A, Streptodornase, Streptokinase, Candida) were within normal limits The clinical course was characterized by rapid improvement after control of diabetes and amphotericin therapy. Clinical observations and experimental evidence suggest that decreased granulocyte number and function predispose to invasive aspergillus infection. The pattern of immunodeficiency in the diabetic host is consistent with these abnormalities in that granulocyte function is impaired in diabetic acidosis.
TL;DR: It is concluded that Rrs measurement by the RrsEX method may provide information of clinical value, because inspiratory methods for measurement of Rrs fail to identify expiratory limitation of flow through airways of narrowed caliber.
Abstract: The purpose of this study was to evaluate three bedside methods for measuring respiratory system resistance to airflow (Rrs). To this end, we studied 19 intubated patients, 6 of whom had diseases characterized predominantly by acute airway obstruction (Group I) and 13 in whom respiratory failure was attributable to extensive pneumonia or edema (Group II). For two of the methods, pressure and flow were measured during assisted inhalation. In one, designated RrsIP, driving pressure was taken as the difference between peak airway pressure and airway pressure recorded with the lung held at inflation after a tidal breath. Flow was measured during assisted inhalation. Method 2, designated RrsIC, differed from RrsIP in that driving pressure was calculated from the airway pressure measured at mid-tidal inhalation, with a correction for dynamic compliance. In contrast, for Method 3, driving pressure was derived from the static pressure-volume curve of the respiratory system and flow was measured during passive exhalation (RrsEX). RrsEX was significantly higher in Group I than in Group II patients, the values (mean±SD) being 21.3±11.5 and 10.3±7.3 cm H2O/(l/s) respectively (P<0.01). The corresponding values of driving pressures were 10.7±5.7 cm H2O in Group I and 5.3±3.9 cm H2O in Group II. Both inspiratory methods yielded lower values for Rrs, especially in Group I patients with obstructive disease. Neither RrsIP nor RrsIC were significantly different in the two patient groups. We conclude that Rrs measurement by the RrsEX method may provide information of clinical value. We reason that inspiratory methods for measurement of Rrs fail to identify expiratory limitation of flow through airways of narrowed caliber, because the inspiratory pressure in intubated mechanically ventilated patients tends to open rather than compress the flow-limiting regions.
TL;DR: Bronchodilator therapy today presents the practitioner with many choices in the use of theophylline compounds and beta-2 adrenergic agents, and questions of beta tachyphylaxis or tolerance, treatment of the life-threatening asthma attack, and the use in the COPD patient with “fixed” obstruction are discussed.
Abstract: Bronchodilator therapy today presents the practitioner with many choices in the use of theophylline compounds and beta-2 adrenergic agents. There is a logical progression in combining these agents as the disease severity increases. Clinical studies support the use of an inhaled beta-2 agent (when feasible) on a regular schedule as the primary therapy. The technique of sequential inhalation maximizes its effect. Combination with a systemic bronchodilator may provide further bronchodilation. A further escalation of therapy is obtained by combining oral theophylline with an oral beta-2 agent, advancing to full doses of each as needed and as tolerated. However, the combination of suboptimal doses of each produces considerable bronchodilation at a minimum of risk. Theophylline can be prescribed at “full” doses when attention is paid to host factors that influence its metabolism. Guidelines are listed for its acute and chronic use and serum theophylline determinations recommended to facilitate this. Low trough levels of rapidly absorbed oral bronchodilators, particularly beta-2 agents, pose a danger to certain severe asthmatics, especially when the night-time hiatus of a “q.i.d.” or “t.i.d.” dosing schedule coincides with marked circadian nocturnal bronchospasm. This problem deserves better kinetic definition and more attention. The use of sustained-release preparations or more frequent dosing of smaller amounts will reduce this danger. Other problems discussed are the questions of beta tachyphylaxis or tolerance, treatment of the life-threatening asthma attack, and the use of bronchodilators in the COPD patient with “fixed” obstruction.
TL;DR: In this series a definitive diagnosis was established by OLB in all cases and no mortality was related to the operative procedure, therefore, OLB is recommended as the diagnostic procedure of first choice, particularly in critically ill patients.
Abstract: Forty-three consecutive patients with diffuse pulmonary disease who underwent open lung biopsy (OLB) are reviewed Twenty-two of them had severely impaired respiratory function, pulmonary hypertension or coagulopathy, which in this institution are regarded as contraindications to alternative transbronchial or percutaneous biopsies The surgical technique and the schedule of histopathological investigations are briefly described In this series a definitive diagnosis was established by OLB in all cases The incidence of complications was 7% In spite of a high percentage of critically ill patients no mortality was related to the operative procedure OLB, therefore, is recommended as the diagnostic procedure of first choice, particularly in critically ill patients
TL;DR: Ten male patients with pre-existing bullous disease whose chest radiographs showed a pulmonary infiltrate adjacent to thin-walled air space with one or more air-fluid levels were observed, finding no evidence of endobronchial disease, tuberculosis, or cancer.
Abstract: Although air-fluid levels occur commonly within lung bullae, this entity in association with non-tuberculous pneumonitis has received neither adequate nor recent emphasis. We observed ten male patients with pre-existing bullous disease whose chest radiographs showed a pulmonary infiltrate adjacent to thin-walled air space(s) with one or more air-fluid levels. Six patients were symptomatic and only one was acutely ill. Fiberoptic bronchoscopy (8/10 patients) revealed no evidence of endobronchial disease, tuberculosis, or cancer. Air-fluid levels disappeared within 3 days to 36 weeks (mean, 11 weeks), while the alveolar infiltrate cleared at a slower rate. Although the mechanism of fluid formation within a bulla is unknown, it may be analogous to the development of a parapneumonic pleural effusion. Fiberoptic bronchoscopy is useful to exclude the presence of an obstructing endobronchial lesion and to obtain secretions for cytology and culture of specific organisms. Recognition of this entity is important since radiographic resolution can be expected to be slow and surgical intervention is unnecessary.
TL;DR: A difference in the duration of subsensitivity in the two systems suggests that the beta adrenergic effects on airway smooth muscle may be mediated through mechanisms other than tissue cAMP levels.
Abstract: Possible subsensitivity to the bronchodilator effects of beta adrenergic agonists has been a clinical concern for the past decade. We have examined this possibility in guinea pigs who were treated in vivo with isoproterenol, either 375 µg/kg BW (single dose) or 75 µg/kg BW every 20 min for 5 h (multiple dose). Tracheal segments were isolated from control and treated animals at 1/2, 1, 2, 4, and 6 h after the last injection and the isoproterenol cumulative dose-response relaxation curves were examined in vitro (n=92 prep.). Segments of the same tracheas were also used for measurement of “basal” cAMP and cAMP response to isoproterenol stimulation in vitro (n=78 prep.). Subsensitivity to isoproterenol-induced tracheal relaxation was present 1 h after single or multiple doses of in vivo treatment. At all other times the ED50 for tracheal relaxation was similar to the control group. There were marked alterations in tracheal cAMP responses to adrenergic stimulation in vitro. After single doses of in vivo treatment, cAMP response was markedly enhanced at 1/2 h, suppressed at 1 h, and normal thereafter. After multiple doses, cAMP was suppressed for 6 h. This difference in the duration of subsensitivity in the two systems suggests that the beta adrenergic effects on airway smooth muscle may be mediated through mechanisms other than tissue cAMP levels.
TL;DR: The biochemical properties of the pulmonary circulation are reviewed, with special reference to the fate of biologically active substances in the blood.
Abstract: The biochemical properties of the pulmonary circulation are reviewed, with special reference to the fate of biologically active substances in the blood. Possible physiological, pathological, pharmacological and practical implications of clinical relevance are discussed.
TL;DR: Early biochemical response of sheep exposed to asbestos is characterized by a significant eosinophilia and increases ofα1-globulins and cyclic AMP in the bronchoalveolar milieu, which may be involved in the chronic inflammatory reaction to asbestos and possibly in the fibrogenic response.
Abstract: A conscious sheep model which allows sequential analysis of the bronchoalveolar milieu was used to investigate the early biochemical events following asbestos exposure. Segmental bronchoalveolar lavages (BAL) were performed in a group of 15 sheep exposed to repeated doses of UICC chrysotile B asbestos (0–128 mg) over a six month period. BAL cell population was analysed and various humoral components including total proteins, albumin, alpha1-globulins (α1), alpha2-globulins (α2), beta + gamma globulins (β+γ) and adenosine 3′,5′-cyclic monophosphate (cAMP) were determined in cell free supernates. All animals were also studied by pulmonary function tests (PF) and transbronchial lung biopsies (LB). Exposure to asbestos (up to 128 mg/month) did not cause any significant alteration of pulmonary functions and lung histology. However, analyses of the BAL effluent revealed that BAL fluids of sheep exposed to asbestos contained higher levels ofα1-globulins and cyclic AMP as compared to controls. Furthermore this phenomenon was observed without overall change of BAL cell population except for a significant eosinophilia in the asbestos-exposed animals. These data demonstrate that the early biochemical response of sheep exposed to asbestos is characterized by a significant eosinophilia and increases ofα1-globulins and cyclic AMP in the bronchoalveolar milieu. These biochemical events may be involved in the chronic inflammatory reaction to asbestos and possibly in the fibrogenic response.
TL;DR: Using air and 80% helium-20% oxygen maximal expiratory flow-volume curves and measurements of pulmonary mechanics, the site of airway obstruction in asthmatic children without the above clinical factors is found to be in the central or peripheral airways or both.
Abstract: The site of airway obstruction in asthmatics may be in the central or peripheral airways. Recent studies with air and 80% helium/20% oxygen maximal expiratory flow-volume curves have suggested that this obstruction was predominantly in the central airways unless there were complicating clinical factors such as chronic bronchitis, recurrent respiratory infection or smoking. Others have indicated that peripheral airway obstruction is present in some asymptomatic asthmatics. Using air and 80% helium-20% oxygen maximal expiratory flow-volume curves and measurements of pulmonary mechanics, we studied the site of airway obstruction in asthmatic children without the above clinical factors and found it to be in the central or peripheral airways or both.
TL;DR: Occasional patients with superior vena cava syndrome due to lung carcinoma may have long periods of disease-free survival, therefore, curative radiation therapy is indicated for this condition.
Abstract: Prolonged survival in patients with bronchogenic carcinoma and superior vena cava syndrome is rare. One patient with this syndrome due to epidermoid carcinoma of the lung has survived 10 years following radiation therapy. Occasional patients with superior vena cava syndrome due to lung carcinoma may have long periods of disease-free survival. Therefore, curative radiation therapy is indicated for this condition.
TL;DR: Influence of hemoglobin concentration was greater at 3600 m than at sea level, which could be due to capillary oxygen pressure and/or to the ratio DM/Vc but not to racial or genetic factors.
Abstract: Lung diffusing capacity (DLCO) was measured using a steady state method in high altitude (3600 m) natives. Regression coefficients ofDLCO with height, age and hemoglobin concentration were determined and compared with results obtained with the same method at sea level. Influence of hemoglobin concentration was greater at 3600 m than at sea level. This difference could be due to capillary oxygen pressure and/or to the ratio DM/Vc but not to racial or genetic factors.
TL;DR: From both theoretical and practical points of view, total lung capacity (TLC) is a more logical and more reproducible reference for matching air and helium-oxygen MEFV curves.
Abstract: The helium to air difference in maximal expiratory flow at mid-vital capacity (ΔHe 50%) and the volume at which air and helium expired flow rates become identical (Viso\(\mathop V\limits^ \bullet \)) are currently measured from maximal expiratory flow-volume (MEFV) curves with the largest forced vital capacities (FVC) superimposed at residual volume (RV). True FVC and maximal flows may be obtained by superimposing several MEFV tracings to construct a “composite” (envelope) curve. From both theoretical and practical points of view, total lung capacity (TLC) is a more logical and more reproducible reference for matching air and helium-oxygen MEFV curves. The use of composite MEFV matched at TLC was compared to the conventional procedure in 41 healthy subjects aged 18 to 54 years. No significant difference for δHe 50% and Viso\(\mathop V\limits^ \bullet \) resulted from the application of the modifications proposed but the number of subjects with absent Viso\(\mathop V\limits^ \bullet \) increased with superimposition at TLC. The intersubject variability of the ΔHe 50% was decreased and that of Viso\(\mathop V\limits^ \bullet \) was increased. The sensitivity of both variables to the relationship between air and He + O2 FVC is stressed.
TL;DR: The blood monocyte and lymphocyte populations were studied in patients with acute sarcoidosis and normal subjects and it is suggested that the impairment of PHA response might be due to the striking increase of monocytes by a diluting effect in cell cultures or by a suppressor effect.
Abstract: The blood monocyte and lymphocyte populations were studied in 18 patients with acute sarcoidosis and 10 normal subjects. The patients with sarcoidosis were divided in two groups according to their tuberculin sensitivity. Anergic patients (61%) showed fewer lymphocytes, particularly T lymphocytes, relatively more monocytes and an impaired response to PHA. Patients with positive tuberculin test (39%) showed similar results to controls. It is suggested that the impairment of PHA response might be due to the striking increase of monocytes by a diluting effect in cell cultures or by a suppressor effect.
TL;DR: Results from indicator washout and spontaneous deflation reveal that Pmin(+) conditions produce a more even inflation of the lung parenchyma and dilate airways at low lung volumes.
Abstract: Alterations in the PV relationships of isolated rabbit lungs which are dependent on the minimal deflation pressure (Pmin) have been studied. When Pmin remains positive both inflation and deflation limbs of the PV loop are shifted toward lower transpulmonary (P1) pressures throughout most of the cycle. In addition, Pmin(+) conditions eliminate the deflation inflection and increase deflation compliance at low and mid-lung volumes. Results from indicator washout and spontaneous deflation reveal that Pmin(+) conditions produce a more even inflation of the lung parenchyma and dilate airways at low lung volumes. These effects cause a stabilization of the parenchyma and a delay in airway closure resulting in the increased deflation compliance and a decrease in the trapped gas volume during Pmin(+) conditions. The relevance of Pmin(+) and (−) conditions are discussed for several clinical conditions.
TL;DR: This annual review of pulmonary medicine has produced a series which the nonspecialist can read with enjoyment and profit and from which a specialist is bound to derive important information as well as critical insight.
Abstract: The other classic is the article by Reynolds and Merrill on humoral and cellular immune responses in the respiratory tract. This highly technical subject is literally brought to life by the vivid descriptions of events occurring at various sites within the airways and lungs so that the non-expert emerges with a clear picture of the immune response which so effectively maintains health in normal people but may, if disturbed, cause or contribute to disease. It is now clear that this annual review will continue to play a very important role in the continuing education of the pulmonary physician and scientist. There is an inevitable redundancy from year to year and even within a single volume, but this is of little consequence, and the wisdom of the editor in selecting authors and topics has produced a series which the nonspecialist can read with enjoyment and profit and from which a specialist is bound to derive important information as well as critical insight. We owe a great debt to Daniel Simmons who had the foresight to embark on this series and the tenacity to pursue it with vigor and skill.