摘要:

Aim. The aim of this study was (1) to assess the value of common lung function variables in the follow-up of patients with obstructive lesions of the larynx and trachea and (2) to study the respiratory response to progressive upper airway stenosis at rest and during exercise. Methods. Lung function tests, including vital capacity (VC), residual volume (RV), total body plethysmographic resistance (RT), specific body plethysmographic resistance (Rs), total body plethysmographic resistance at low inspiratory/expiratory flows (Rlo), forced expiratory volume in 1 s (FEV1), peak expiratory flow rate (PEF), peak inspiratory flow rate (PIF), maximum expiratory flow at 50% VC(MEF50) and maximum inspiratory flow at 50% VC (MIF50) were performed in 14 normal subjects with added external resistive loads (inner diameter of circular orifice: 15, 10, 8, 6 mm; equivalent to surface areas of 177, 79, 50 and 28 mm2, respectively), applied in random order. The relative sensitivity of each variable to detect a stepwise decrease in orifice size by evoking ‘relevant’ obstructive responses was calculated. In addition, ventilatory and gaz exchange responses to loaded breathing (10-, 8- and 6-mm orifices, randomly inserted) during steady-state bicycle exercise (80 and 160 W) were assessed in a subgroup of 10 subjects. Results. The gradual increase of external load did not influence static lung volumes (VC, RV). MEF50/MIF50 (1.63 ± 1.03 at baseline) remained essentially unchanged, consistent with the rigid nature of the obstructive device. PEF was superior in reproducing the transition from unloaded over mild (15 mm) and moderate (10 mm) to high grade (8 mm) central obstruction. Except for mild loads, PIF was equal in sensitivity to PEF. At high grade (8 mm) and severe loads (6 mm), no difference in sensitivity could be established between RT, Rs, FEV1 PIF and PEF. However, they were all superior to Rlo. Compared to unloaded breathing, ventilation across the 10- and 8-mm orifices at both rest and exercise produced a continuous significant increase in oxygen uptake (VO2). Respiratory rate (RR) fell, and a simultaneous enlargement of tidal volume (VT) was observed to maintain or even enhance minute ventilation (VE). However, ventilation across the 6 mm orifice was associated with a substantial decline in VO2, VCO2 and VE relative to the preceding load (8 mm). Conclusions. It is suggested that the experimental use of inspiratory and expiratory extrinsic loads can mimic rigid obstructive lesions of the larynx and trachea. Among all conventional lung function values, PEF and, to a certain degree, PIF, seem to be the best suitable follow-up parameters to assess airway mechanics before and after surgical/endoscopic procedures. Upper airway stenosis involving surface areas of no more than 50 mm2 can be overcome using adequate respiratory compensation. But any additional narrowing below this limit will result in hypoventilation, inappropriate oxygen uptake and retention of CO2. Thus, experimental evidence indicates that laryngotracheal obstruction within a critical range below 50 mm2 surface area (diameter of circular orifice < 8 mm) compromises respiratory efforts enough to be of clinical import

ISSN:0025-7931    

DOI:10.1159/000196444

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

The present study was undertaken to examine the pulmonary vascular and ventilatory responses to acute hypoxia in healthy individuals. Pulmonary hemodynamics and minute ventilation (VE) were serially measured during inhalation of 13% O2 for 15 min. There was a wide variability in the pulmonary vascular response to acute hypoxia, and a significant negative correlation between the initial increase in VE after the start of hypoxia (ΔVE) and the percent increase in mean pulmonary arterial pressure (r = -0.646; p < 0.01). The fall in arterial oxygen tension significantly decreased in response to an increase in ΔVE. These results support the view that a blunted ventilatory response to acute hypoxic stimulation enhances alveolar hypoxia, thereby favoring the constriction of pulmonary vasculature. Thus, our results suggest that the ventilatory response to acute hypoxia plays a significant role in the pulmonary vascular response to acute hypoxi

ISSN:0025-7931    

DOI:10.1159/000196445

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

As an example of β2 7 times stronger than seen from any plasma concentration after intravenous administration. It is assumed that there are structures near the β2-bronchodilator receptor which are responsible for the long-lasting effect that is observed only after aerosol inhalation. These depot structures cannot be reached from the plasma in concentrations needed under in vivo conditions. Loss of these structures shortens the duration of the bronchodilator effect. In respect to effect/side effect relationship, more frequent administration of smaller doses may be the best method for administering β2-agonists as aerosols in patients with COAD. For many patients with severe forms of this disease, individual optimal dosage with MDI has to be defined following repeated measurements of the airway obstruction so as to achieve the best possible bronchodilatat

ISSN:0025-7931    

DOI:10.1159/000196446

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

We studied 196 patients with suspicion of pulmonary embolism (PE), subsequently confirmed in 98 by positive pulmonary angiography and excluded in 98 by normal or near-normal perfusion lung scan. Patients had a clinical questionnaire for history, and, soon after, a radiograph, blood gas analysis, and an ECG. Clinical and instrumental signs were matched in patients with confirmed and unconfirmed PE to find those more frequent in embolic patients and, thus, more characteristic of PE. The following were: previous PE, immobilization and thrombophlebitis (p < 0.05); dyspnea and cough (p < 0.05); enlarged descending pulmonary artery (DPA), enlarged right heart, pulmonary infarction, Westermark sign (p < 0.001), and elevated diaphragm (p < 0.05); hypoxemia. No ECG sign was more frequent in PE. Thereafter, all variables were processed separately with a logistic multiple regression analysis and those significantly associated to PE were tested in a final logistic model that was able to predict the actual result of angiography or scintigraphy; accordingly, previous PE, immobilization, thrombophlebitis, enlarged DP A, pulmonary infarction, Westermark sign, hypoxemia were significantly associated with a high risk of PE (from 2.8 to 15 times greater than in patients without these signs). Therefore, we may conclude that clinical assessment and noninvasive tests may help to detect patients at higher risk for PE where heparin coverage should be started while waiting for conclusive diagnostic procedures.

ISSN:0025-7931    

DOI:10.1159/000196447

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

The effect of estrogen on smooth muscle in various organs is unpredictable. Little is known about the effect of estrogen on respiratory tract smooth muscle, particularly in humans. In the present study we used the histamine challenge test (HCT) to assess the effect of estrogen replacement therapy (ERT) on airway reactivity in postmenopausal women who did not suffer from respiratory disease. Thirty-six women who were undergoing treatment at the postmenopausal clinic completed the study. All participants were nonsmokers whose pulmonary function tests were normal. HCT was performed twice before the inception of ERT, and a third time 4-6 weeks after ERT was begun. None of the 36 women demonstrated a 20% decrease in FEV1 values (PC20) after inhaling histamine at a concentration of 8 mg/ml, either before or during ERT. The maximal decrease in FEV1 values in response to the maximum concentration of histamine was significantly lower during ERT compared to the pretreatment period. The average maximal decrease in FEV1 during ERT was 2.63 ± 2.72% (mean ± DS) compared to 5.21 ± 4.47% and 6.57 ± 5.28% on the 2 tests prior to therapy (p < 0.0002). We conclude that ERT has an inhibitory effect on the bronchial reactivity of respiratory smooth muscle. There is no cause for concern about increased airway reactivity as an adverse effect of this ther

ISSN:0025-7931    

DOI:10.1159/000196448

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

Fibrosing alveolitis (FA) is a major and often fatal complication of systemic sclerosis (SSC). The critical role of fibroblasts in the pathogenesis of FA has long been recognized. Characterization of fibroblast activation in the lungs may improve our understanding and the management of this disease. We analyzed bronchoalveolar lavage (BAL) fluid samples from 9 healthy controls and 43 patients with FA caused by lung involvement form SSC. The chemoattractant activity (CAA) of cultured human fibroblasts elicited by native BAL fluid was measured in Boyden chambers. In addition, procoUagen III peptide was measured in BAL fluid as a marker of collagen synthesis. CAA (expressed as percentage of the chemoattractant effect of 0.25 ng/ml platelet-derived growth factor; PDGF) was elevated in the SSC patients compared with that of the controls (control: 12.6 ± 4.0%; SSC: 68.8 ± 15.2%; p < 0.01). A positive correlation was found between BAL total cell count and CAA (r = 0.60, p < 0.01). An inverse correlation existed between CAA and total lung capacity (r = -0.55, p < 0.05). The patients were followed up for 13.3 ± 1.4 months (mean ± SEM). Twenty-seven patients received immunosuppressive therapy, whereas 16 refused therapy. The patients were assigned to two groups according to their CAA being lower or higher than 36% of the PDGF response (= mean value of the controls + 2 SD). During follow-up, patients in the high CAA group showed lung function deterioration if untreated, whereas stabilization or improvement of lung function occurred under immunosuppressive therapy; the differences between untreated and treated patients were statistically significant for the changes in vital capacity, total lung capacity and diffusing capacity (p < 0.05). In the low-CAA group, untreated and treated patients did not differ significantly with respect to the change in lung function parameters. We conclude that CAA may serve as a marker of profibrotic activity within the epithelial lining fluid of patients with FA caused by SSC. The results suggest that parameters reflecting activation of pulmonary fibroblasts provide relevant information about disease activity and may improve the management of FA in patients suffering from

ISSN:0025-7931    

DOI:10.1159/000196449

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

To evaluate the effects of roxithromycin in patients with chronic lower respiratory tract disease including diffuse panbronchiolitis, we studied lymphocyte function-associated antigen-1 (LFA-1) and Mac-1, neutrophil adhesion molecules, using peripheral neutrophils from healthy volunteers and from patients with chronic lower respiratory tract disease. The number of Mac-1 expressed on neutrophils of the patients was significantly greater (0.68 ± 0.16) than in the healthy subjects (0.45 ± 0.14), while the number of LFA-1 expressed on neutrophils of the patients was nearly similar to that in the healthy volunteers (0.95 ± 0.10 vs. 0.89 ± 0.11). The neutrophil numbers in bronchoalveolar lavage fluid and the number of Mac-1 expressed on peripheral neutrophils significantly decreased in all patients who responded clinically to a low dose of roxithromycin for a long period of time (56.0 ± 25.2 vs. 22.7 ± 19.7%, p < 0.05 and 0.70 ± 0.16 vs. 0.59 ± 0.08, p < 0.05, respectively), whereas roxithromycin had no effect on the quantitative expression of LFA-1 (0.96 ± 0.14 to 1.00 ± 0.09, not significant) in all r

ISSN:0025-7931    

DOI:10.1159/000196450

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

We immunohistochemically investigated the expression of glutathione S transferase π (GST-π) and clarified the correlation between GST-π and the results of chemosensitivity testing on the tissue of primary human squamous-cell carcinoma of the lung. The expression of GST-π was evaluated in 105 cases and their level of chemosensitivity was estimated by the in vitro succinate dehydrogenase inhibition test for cisplatin, Adriamycin, cyclophosphamide, mitomycin C, vindesine and flurouracil. Tumors in which 25% and more of the cells stained for GST-π were classified as having a high GST-π expression, while those tumors demonstrating less than 25% of the cells staining for GST-π were considered to have a low expression GST-π. The percentage of high GST-π was 52% (53 of 105) while that of low GST- π was 48% (52 of 105). No significant correlation between the expression of GST-π and clinico-pathologic factors was observed, while no significant difference in the survival of the two groups was found either. An increase in succinate dehydrogenase activity was recognized in the high-GST-π group compared with the low-GST-π group for each anticancer drug; however, no statistical significance was seen except for cisplatin. In the cases with adjuvant combination chemotherapy using cisplatin after a complete resection, all cases demonstrating a relapse were associated with a high GST-π. These findings thus indicate that an over-expression of GST-π is related to the resistance to cisplatin in human lung squamous-cell carcinoma. It is therefore important to select carefully the optimal anticancer drug for hi

ISSN:0025-7931    

DOI:10.1159/000196451

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

Severe bronchial hyperresponsiveness to methacholine developed after intravenous therapy with OK-T3 and IL-2 in a patient with multiple myeloma, in whom no factors known to be associated with bronchial hyperresponsiveness were present. A substantial increase and activation of peripheral T-lymphocytes was observed after immunotherapy. Bronchial responsiveness and lymphocyte subsets both returned to normal baseline values 2 months after the patient was shifted to subcutaneous low dose administration of IL-2. The strict association between peripheral T-lymphocytes activation and the development of bronchial hyperresponsiveness suggests a causal relationship.

ISSN:0025-7931    

DOI:10.1159/000196452

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

Case of a 33-year-old female with AIDS who presented with fevers, chills, lower back pain and a large right hilar mass. Biopsy of the right paratracheal nodes revealed poorly differentiated non-small cell carcinoma with extensive necrosis. In patients infected with HIV the incidence of primary lung carcinoma is unknown. Despite these uncertainties, primary lung carcinoma must be considered in the differential diagnosis of young HIV-infected individuals presenting with intrathoracic radiographic abnormalities.

ISSN:0025-7931    

DOI:10.1159/000196453

出版商:S. Karger AG    

年代:1995

数据来源: Karger