Precursors to pulmonary neoplasia

Squamous dysplasia in the bronchi has been long recognized as a precursor of lung carcinoma, particularly squamous carcinoma. Atypical adenomatous hyperplasia (AAH) has been recently implicated as a precursor to adenocarcinoma. Bronchiolar neuroendocrine cell hyperplasia has also been suggested as a precursor to some pulmonary carcinoid tumors. The atypical adenomatous hyperplasia-adenocarcinoma sequence has been likened to the adenoma-carcinoma sequence in the large intestine. AAH is commonly multifocal, and may explain multicentricity that is observed with some adenocarcinomas. AAH has been shown to have immunohistochemical, morphometric, flow cytometric and genetic abnormalities overlapping with adenocarcinoma. Bronchiolar neuroendocrine cell hyperplasia (carcinoid tumorlets) is classically associated with inflammatory lesions in the airways, but may also be multifocal and bilateral. In the latter setting, lesions may attain a size greater than 0.5 cm and be (arbitrarily) classified as carcinoid tumors.     

Neuroendocrine cell hyperplasia and obliterative bronchiolitis in patients with peripheral carcinoid tumors

Specimens from 25 consecutive patients undergoing lung resection for peripheral carcinoid tumor were examined for evidence of neuroendocrine cell hyperplasia and associated obliterative bronchiolitis. Where available, the CT scans (n = 11) were reviewed for evidence of multiple tumors, and pulmonary function data (n = 16) were reviewed for evidence of airflow obstruction. Nineteen of the 25 patients (76%) had neuroendocrine cell hyperplasia in addition to the dominant carcinoid tumor. Eight patients (32%) had lesions of obliterative bronchiolitis associated with foci of neuroendocrine cell hyperplasia, and two of these patients had asymptomatic airflow obstruction that could not be related to smoking or other lung disease. We conclude that multicentric neuroendocrine cell proliferation is common in patients with peripheral carcinoid tumor of the lung. Associated bronchiolar fibrosis occurs in a high proportion of such patients, but it is usually asymptomatic.     

Associations between breathing pattern during submaximal exercise and exercise capacity in patients with pulmonary emphysema

We sought to clarify the factors associated with exercise capacity in patients with pulmonary emphysema. Exercise capacities of 20 men with pulmonary emphysema were evaluated by bicycle ergometery, and the results were used to divide the subjects into two groups: high exercise capacity (n = 10) and low exercise capacity (n = 10). Pulmonary-function tests were done, emphysema scores were computed from CT scans, breathing pattern was recorded during submaximal exercise (up to 20 watts), and index of rapid shallow breathing was computed. Neither FEV1 nor airway resistance differed between the two groups, and patients with lower exercise capacity tended to have lower tidal volumes and higher values of the index of rapid shallow breathing during submaximal exercise. Functional residual capacity measured by body plethysmography and emphysema scores were inversely associated with exercise capacity. We speculate that among patients with pulmonary emphysema and a given degree of airway obstruction, a high functional residual capacity causes breathing during submaxinal exercise to be rapid and shallow, and that this rapid and shallow breathing makes ventilation inefficient, increases the work of breathing, and limits exercise capacity.     

Radiology of chronic obstructive pulmonary disease

This article reviews the radiologic manifestations and complications of chronic obstructive pulmonary disease, particularly those seen in association with emphysema. Current concepts on the pathogenesis of chronic obstructive pulmonary disease are discussed and related to findings on high-resolution CT scan and histologic examinations. Controversial issues concerning the detection and grading of emphysema using radiologic and physiologic tests are also addressed.     

Evaluation of emphysema progression as measured by computed tomography in patients with chronic obstructive pulmonary disease

It has been difficult to assess the progression of pulmonary emphysema since accurate quantification of the extent of this condition has only previously been possible on post mortem or resected lungs. Previously we have shown that measurements of CT lung density correlated with the degree of emphysema, measured morphometrically in resected lungs. We have therefore employed this technique to assess the progression of emphysema in 17 patients (12M, 5F) with wide range of chronic airflow limitation (FEV1 15-68% predicted). There was little change in the degree of airflow limitation, hyperinflation or arterial blood gas values over 30 +/- 4 months of follow up (p > 0.05). However during this period there was a significant decrease in the lowest 5th percentile of CT density, which fell from -920 +/- 32 to -940 +/- 36 Hounsfield units (p < 0.005) associated with significant fall in the diffusing capacity for carbon monoxide. We believe that these data show the ability of CT scanning to assess the progression of emphysema in patients with chronic obstructive pulmonary disease.     

Pulmonary barotrauma as the cause of pneumoretropharynx in pulmonary lymphangioleiomyomatosis

A 55-year-old white woman with pulmonary lymphangioleiomyomatosis (LAM) presented to the emergency department with odynophagia and subplatysmal emphysema after a paroxysm of coughing. Lateral neck films showed subcutaneous emphysema and a retropharyngeal air stripe. Chest radiographs showed neither pneumothorax nor pneumomediastinum. Patients with LAM frequently develop pulmonary barotrauma and pneumothoracies. This patient, however, had undergone prior bilateral talc pleuradesis as treatment for recurrent pneumothoracies and, thus, could not manifest this complication of barotrauma. This case illustrates the uncommon occurrence of superior dissection of air after pulmonary barotrauma.     

Pathophysiology of chronic obstructive pulmonary disease

Emphysema with bullae is a common feature of patients with chronic obstructive pulmonary disease. Central to the pathophysiology of emphysema is the presence of airflow obstruction and lung and chest hyperinflation. Because of the increased ventilatory demand and the need to maintain gas exchange, patients with emphysema increase their work of breathing. This article reviews the adaptive and maladaptive consequences of these changes. A rationale is given as to the possible mechanism by which surgery aimed at resecting hyperinflated portions of the lungs may be effective.     

Appetite suppressant drugs as inhibitors of human cytochromes P450: in vitro inhibition of P450-2D6 by D- and L-fenfluramine, but not phentermine

BACKGROUND: We compared our results with bullous vs diffuse emphysema by performing a bilateral thoracoscopic stapled volume reduction technique in 15 patients (age 45-80, 10 males, five females). METHODS: Eight patients demonstrated bullous emphysema and seven patients diffuse emphysema. Lung reduction was performed with a bilateral thoracoscopic stapled technique utilizing bovine pericardium in the supine position. RESULTS: Comparison of the bullous versus diffuse groups revealed no significant differences in means for the following variables: length of air leak (7.5 vs 3.3 days); length of stay (8.1 vs 6.5 days); pre-op FEV1, (23% vs 22%); pre-op dyspnea index (3.4 vs 3.6). At 3 months the bullous subset had a highly significant improvement (p < 0.007) in FEV1 (88%) compared with the diffuse subset FEV1 (59%). CONCLUSIONS: These early results suggest that patients with bullous emphysema are at no greater risk and demonstrate a significantly greater improvement in FEV1 than patients with diffuse emphysema.     

Large sub-pleural air cysts: an extreme form of pulmonary interstitial emphysema

Pulmonary interstitial emphysema is a well-documented complication of positive-pressure ventilation. However, the occurrence of large sub-pleural air cysts is a less well-known, extreme manifestation of this entity. We present here an infant who developed this complication of pulmonary barotrauma during cardiopulmonary resuscitative efforts.     

Amiodarone induced pulmonary fibrosis in infancy

We report a case of pulmonary fibrosis in an infant receiving amiodarone for treatment of intractable atrioventricular reentrant tachycardia secondary to Wolff-Parkinson-White syndrome. At 9 months, a screening chest radiograph showed a diffuse interstitial infiltrate in an asymptomatic, thriving infant. Amiodarone was discontinued and the pulmonary fibrosis resolved gradually over 6 months. This case documents the first report of amiodarone induced pulmonary fibrosis in the pediatric age group. We speculate that as amiodarone is used more frequently to manage pediatric arrhythmias, pulmonary fibrosis, a known complication of this antiarrhythmia in adults may be seen with increasing frequency in children.     

Bronchopulmonary dysplasia: the pulmonary pathologic sequel of necrotizing bronchiolitis and pulmonary fibrosis

A light and electron microscopic study was carried out in 21 infants in whom the pathologic diagnosis of bronchopulmonary dysplasia had been made. All the infants except two had the respiratory distress syndrome at birth, and all 21 had been treated with respirator and oxygen therapy for various periods of time. The pathologic alterations observed in all the infants studied were primarily damage of the bronchial and bronchiolar ciliary apparatus and mucous membranes, severe necrotizing bronchiolitis, and marked bronchiolar and alveolar fibrosis. These changes were more pronounced in infants who survived the longest period of time. Such inflammatory and fibrotic changes are known to predispose to destruction of lung tissue, emphysema, and pulmonary hypertension. Six of these 21 infants developed symptoms and signs of cardiac atrial or ventricular stress, including cor pulmonale, prior to their demise. These infants were among those that survived the longest periods of time, had the longest exposure to supplemental oxygen, and showed histopathologically severe pulmonary fibrosis and emphysema.     

Surgical treatment of pulmonary aspergillosis

There is controversy about the optimal treatment for pulmonary aspergillosis. Eight patients with pulmonary aspergilloma underwent surgical treatment. Three patients had tuberculosis, one Sj?gren syndrome, one aortitis syndrome, one malignant lymphoma. Lobectomy was performed in five patients, segmentectomy in three patients. All patients are alive and have no recurrence. We have obtained excellent results from surgery and advocate early surgery for localized lesions to prevent life-threatening hemoptysis. This will allow patients to continue with further treatment for the underlying disease. We encountered a granulocytopenic patient with rapidly progressive aspergillus infection resulting in occlusion of main pulmonary artery leading to death. Surgical intervention could not prevent this fatal outcome. The selection of the patients with diffuse lesions should be made carefully.     

The use of health care services by people with diabetes in rural areas

Stapled lung volume reduction surgery (LVRS) has recently been described for treatment of emphysema. Many questions arise regarding physiologic mechanisms of response from surgical treatment of emphysema. The objective of this study was to develop an animal model for the study of lung volume reduction surgery in diffuse heterogeneous emphysema. We hypothesized that elastic recoil would increase, static respiratory system compliance would decrease, and expiratory flows would increase after lung volume reduction surgery in animals with emphysema. In the study, emphysema was induced in 31 New Zealand White rabbits (3-5 kg) with endotracheally aerosalized porcine elastase (10,000-12,000 U). Lateral thoracotomies were performed 4-6 weeks postinduction under general anesthesia and mechanical ventilatory support. Stapled volume reduction was performed on the right lower lobe using a standard multirow pediatric stapler (U.S. Surgical). Pulmonary function tests were performed at baseline (preinduction), before stapling LVRS (postemphysema induction), immediately post stapling LVRS, and 1 week poststapling. Static respiratory system compliance, flow, conductance and forced expiratory flows, and peak flows at 20 and 40 cm3 of exhaled volume were analyzed. Animals were sacrificed 1 week poststapling, and bilateral lungs were harvested for histopathology. Diffuse but heterogeneous pulmonary emphysema was seen in these animals treated with high-dose aerosolized elastase. Static compliance increased, while expiratory flows and conductance decreased after induction of emphysema. Immediately post stapled volume reduction therapy, animals had decreased static compliance. By 1 week following surgery, animals showed increased forced expiratory flows and decreased expiratory resistance, although compliance was similar to preoperative levels. In conclusion, we describe initial results in an animal model of obstructive emphysema suitable for the study of lung volume reduction surgery. Changes in pulmonary function indicate that unilateral lower lobe LVRS increases airway conductance in the rabbits. Findings from LVRS studies in animal models such as this may help explain clinical improvement following LVRS in humans.     

Cigarette smoking: CT and pathologic findings of associated pulmonary diseases

The health risks associated with cigarette smoking are well known. Cigarette smoking is the most important causative factor in the development of bronchogenic carcinoma. Pulmonary diseases such as chronic bronchitis, centrilobular and panacinar emphysema, respiratory bronchiolitis-associated interstitial lung disease (RB-ILD), and pulmonary Langerhans cell histiocytosis are also related to cigarette smoking. In adenocarcinoma and squamous cell carcinoma, the most common manifestation at computed tomography (CT) is a solitary pulmonary nodule; in small cell carcinoma, hilar and mediastinal adenopathy secondary to metastases; and in large cell carcinoma, a mass with central necrosis or cavitation in the lung periphery. For chronic bronchitis, the most common CT finding is bronchial wall thickening, but this finding is nonspecific. Emphysema, both centrilobular and panacinar associated with alpha-1-antitrypsin deficiency, usually manifests as areas of decreased attenuation and may involve bullous changes. However, centrilobular emphysema more commonly involves the upper lungs, whereas panacinar emphysema more commonly involves the lower lungs. Most patients with RB-ILD have normal high-resolution CT scans; however, abnormalities may be present, the most common of which are areas of ground-glass attenuation. CT appearance of pulmonary Langerhans cell histiocytosis varies depending on the disease stage: In the early stage, typical CT findings include multiple nodules, usually accompanied by cystic spaces with thin, well-defined walls. As the disease progresses, the cystic spaces become more numerous and the number of nodules decreases.     

Aerosolized staphylococcal enterotoxin B-induced pulmonary lesions in rhesus monkeys (Macaca mulatta)

The pathology of aerosolized staphylococcal enterotoxin B (SEB) was studied in the nonhuman primate. Six juvenile rhesus monkeys that received multiple lethal inhaled doses of SEB developed diarrhea and vomiting within 24 hr followed by depression, dyspnea, and shock. Three of 6 animals died by 52 hr. The most striking gross lesion in all 6 monkeys was diffuse severe pulmonary edema. Histologically, edema fluid was present within the peribronchiolar, peribronchial, and perivascular interstitium, alveolar septa, and alveoli. The adventitia of pulmonary vessels was infiltrated by lymphocytes, macrophages, and fewer neutrophils. Numerous large lymphocytes with occasional mitotic figures were within pulmonary vessels, often occluding alveolar capillaries. These cells were strongly immunoreactive with monoclonal antibodies against CD3, establishing them as T cells. Ultrastructurally, endothelial cell junctions were intact, and endothelial cells and type I pneumocytes contained numerous pinocytotic vesicles. Alveolar septal interstitial spaces were expanded by edema. The mechanism of these SEB-induced pulmonary lesions was not determined. We hypothesize that cytokine production by activated T cells may have caused vascular permeability changes leading to widespread pulmonary edema and shock.     

Physiopathology of pulmonary emphysema. Analysis of structural changes in the pulmonary architecture and therapeutic implications

In the pulmonary emphysema a serious respiratory inadequacy can result from the impossibility of the thoracic cage and of the diaphragm to expand beyond a maximum limit, before that a significnat part of pulmonary parenchyma has been destroyed by the pathogenic process. The resection of part of the lung, selectively in the areas where the emphysematous injuries are more pronounced, brings again the ventilation of the residual pulmonary parenchyma toward more physiological expansion values of the thoracic cage and diaphragm, thus decreasing the respiratory work, improving the ventilation mechanics and the bronchial obstruction. The time duration of the improvement achieved with the lung volume reduction is still to be demonstrated. A clinical and therapeutic analysis of this pathology is carried out.     

Transient giant negative T wave in acute anterior myocardial infarction predicts R wave recovery and preservation of left ventricular function

Resection of large bullae to decompress adjacent lung tissue with the goal of improving pulmonary function has been an accepted surgical approach for many years. However, the indication for lung volume reduction is not bullous disease but diffuse emphysema and the surgical approach is based on an entirely different concept. The resection of the most affected parts of the emphysematous parenchyma aims at a reduction of the over expansion of the chest with the goal of improving respiratory mechanics. This concept was introduced by Brantigan in 1959, but has failed to gain widespread acceptance until recently. Based on the extensive experience in lung transplantation for patients with end stage emphysema J. D. Cooper reevaluated the idea successfully. He reported remarkable improvements in FEV1 and a reduction in hyperinflation after performing bilateral lung volume reduction through a median sternotomy. During the last 2 years we performed bilateral lung volume reduction in more than 30 patients with diffuse emphysema using video assisted thoracoscopy (VAT) and studied the results prospectively. In the first 20 patients preoperative mean forced expiratory volume in 1 second (FEV1) was 765 ml/sec and improved by a mean of 42% (0-100%) three months postoperatively. This gain in FEV1 was already observed at the end of hospitalisation approximately two weeks after surgery. The 12 minute walking distance improved over 40%. In our highly selected study population we had no perioperative mortality. Lung volume reduction is a palliative treatment of severe pulmonary emphysema. Currently no data is available on the duration of the improvement. In this selected group of patients dyspnea is reduced and pulmonary mechanics are improved, with a resulting increase in quality of life.     

Development of pulmonary hypertension after lung volume reduction surgery

This prospective, longitudinal study was designed to assess the hemodynamic changes occurring in patients who undergo lung volume reduction surgery (LVRS). Patients with emphysema treated with LVRS underwent hemodynamic evaluation before and after surgery. The study group consisted of nine patients with an average age of 64.4 yr. FEV1 rose significantly from 0.64 preoperatively to 0.99 L postoperatively. After surgery, pulmonary artery (PA) systolic pressure rose to 47.9 +/- 12.4 mm Hg, meeting criteria for development of pulmonary hypertension. In six patients, the elevation in PA pressure was attributed to an increase in the pulmonary vascular resistance, but for all nine patients the change was not statistically significant. The pulmonary artery occulsion pressure (PAOP) did not change postoperatively. There was no correlation of PAOP with global left ventricular ejection fraction. While preoperatively there was a negative correlation between symptoms (Mahler dyspnea index) and PA pressure, after surgery the change in PA pressures did not correlate with the change in symptoms (Mahler transitional dyspnea index). We concluded that development of pulmonary hypertension may occur after LVRS in patients whose symptomatic status improves and in whom this condition was not present preoperatively.     

Clinical evaluation of serum type IV collagen 7S in idiopathic pulmonary fibrosis

Type IV collagen is one of the major components of the basement membrane (BM). 7S domain (7S collagen) of type IV collagen is an N-terminal peptide which is stable against protease and heat. We investigated serum concentration of 7S collagen in patients with idiopathic pulmonary fibrosis (IPF) and other pulmonary diseases. The aim of this study was to evaluate whether changes in the serum concentration of 7S collagen reflect the fibrotic process of IPF. We measured the concentration of serum 7S collagen with radioimmunoassay in patients with IPF, chronic pulmonary emphysema (CPE), sarcoidosis, infectious pulmonary diseases (IPD) and normal healthy controls. We also monitored 7S collagen during the clinical course in some patients with IPF and investigated the correlation between the serum 7S collagen, and lactate dehydrogenase (LDH) and erthrocyte sedimentation rate (ESR) in patients with IPF. Patients with IPF showed significantly higher serum concentration of 7S collagen than other pulmonary diseases and healthy controls. The serum concentration of 7S collagen significantly decreased in IPF patients who showed roentgenographic improvement after corticosteroid treatment. There was a correlation between the serum 7S collagen and LDH, and ESR. In conclusion, serum concentrations of 7S collagen increase in patients with IPF. The measurement of 7S collagen is useful for the evaluation of fibrotic change in the lung.     

Elevation of antibodies to cytomegalovirus and other herpes viruses in pulmonary fibrosis

The aim of this study was to determine whether latent viral infection is associated with idiopathic pulmonary fibrosis (IPF), an interstitial lung disease whose aetiology remains to be elucidated. Cytomegalovirus (CMV) immunoglobulin G (IgG) and complement fixation (CF), Epstein-Barr (EB) viral capsid antigen (VCA) IgG, herpes simplex virus (HSV) IgG, adenovirus CF, and parainfluenza 3 virus haemagglutinin inhibition (HI) titres were measured in the serum from patients with pulmonary diseases. The study included five subject groups: 35 normal controls (aged (mean +/- SD) 38 +/- 17 yrs); 43 IPF (63 +/- 10 yrs), seven collagen vascular disease-related interstitial pneumonitis (CVD-IP) (62 +/- 12 yrs); 22 sarcoidosis (36 +/- 14 yrs); and 17 emphysema (66 +/- 11 yrs). Levels of CMV IgG in IPF (87.6 +/- 51.7) and CVD-IP (101.2 +/- 69.9) were significantly elevated compared to those in the control (30.9 +/- 24.1), sarcoidosis (34.4 +/- 38.3) and emphysema groups (40.3 +/- 24.6), whereas CMV immunoglobulin M (IgM) was generally below the limit of detection. Similarly, CMV CF titres in IPF and CVD-IP were elevated compared to those in other diseases. EB VCA IgG titres in IPF, CVD-IP and emphysema and HSV IgG in IPF were also elevated. In contrast, adenovirus CF and parainfluenza 3 HI titres demonstrated no significant difference among all of the groups investigated. Increases in cytomegalovirus immunoglobulin G and complement fixation titres with negative cytomegalovirus immunoglobulin M suggest that latent cytomegalovirus infection may be more prominent in idiopathic pulmonary fibrosis or collagen vascular disease-related interstitial pneumonitis. Together with the elevation of Epstein-Barr virus viral capsid antigen and herpes simplex virus immunoglobulin G in idiopathic pulmonary fibrosis and/or collagen vascular disease-related interstitial pneumonitis, it is rational to assume that these viruses may be implicated in the development of pulmonary fibrosis. Further study is necessary to investigate the relationship between latent viral infection and pulmonary fibrosis.