Peripheral airways as a determinant of ventilatory function in the human lung.

We have investigated the morphological differences responsible for the variability in two tests of pulmonary function, maximal expiratory flow rates (MEF) and the frequency dependence of dynamic compliance (CDYN ratio). Functional measurements were obtained from 53 normal and minimally diseased postmortem human lungs. Morphological measurements performed on these same lungs included airway diameter at three levels in the bronchial tree, the amount of bronchial gland mass, and the alveolar surface to volume ratio. Multiple regression analysis suggests that the diameter of the peripheral conduction airways (membranous bronchioles) is the major morphological determinant for both MEF and the CDYN ratio in lungs at any particular age. Age-dependent changes in both functional tests were associated primarily with differences in the alveolar surface to volume ratio. Minimal emphysema and a lesion associated with cigarette smoking, respiratory bronchiolitis, have no demonstrable effect on either MEF or the CDYN ratio. These studies provide further evidence that the peripheral conducting airways are a major determinant of ventilatory function in the normal human lung.

Degradation of basement membrane by murine tumor cells.

Tumor cells from the murine T241 fibrosarcoma, which rapidly and reproducibility produces pulmonary metastases, were tested in vitro for their ability to degrade isolated pulmonary basement membrane. Degradation of basement membrane substrate was quantified by the culture of the substrate with tumor cells and measurement of the solubilized hydroxyproline and hexose glycoprotein at neutral pH. It was found that tumor cells collected in the tumor venous drainage were associated with a significantly greater solubilization of basement membrane than were tumor cells obtained from the primary tumor mass. Tumor cells were also assayed for their ability to solubilize type I collagen purified from human dura. Venous effluent tumor cells solubilized collagen to a significantly greater level than primary tumor cells, spleen cells, or liver cells. These findings raised the possibility that metastasizing tumor cells may be a distinct tumor subpopulation with regard to invasive potential.

Mechanism of Bacillus Calmette-Guérin-induced suppression of metastases in a poorly immunogenic fibrosarcoma.

Bacillus Calmette-Guérin (BCG) reduces the rate of spontaneous pulmonary metastases from a poorly immunogenic fibrosarcoma. To be effective, BCG (1 X 10(6) organisms) must be given in admixture with (1 X 10(6)) tumor cells at the time of transplantation. Reduction of metastasis at this dosage of BCG occurs without a change in the size of the primarytumor or the extent of necrosis within it. Tumors transplanted in admixture with spleen cells from BCG-exposed donors reduced the number of metastases, while spleen cells from normal or tumor-bearing donors had no effect on metastases. Fewer total tumor cells and clumps are collected from the venous effluent of tumors transplanted with BCG than from control tumors. The BCG-treated tumors have more host macrophages intimately associated with the effluent tumor cells then did controls. These data indicate that BCG can inhibit the metastatic potential of a weakly immunogenic fibrosarcoma. The mechanism of this effect appears to be a depression of entry or tumor cells into the tumor vascular channels which may be related to the interaction of tumor cells with BCG-stimulated macrophages.

The significance of hematogenous tumor cell clumps in the metastatic process.

The relationship between the size distribution of vessels in an implanted tumor, the size distribution of tumor cell clumps collected in the venous effluent of the tumor, and the development of pulmonary metastases have been studied. The purpose is to evaluate the importance of clumps and their site of formation in the metastatic process. The results demonstrate a negative exponential character for both the size distribution of effluent tumor clumps and the tumor vessel population. Tumor trauma or massage increases total tumor cells and clumps released into the effluent. Serial amputation demonstrates that tumor cells are continuously being released on a day-by-day basis in vivo. A linear relationship exists between the proportion of vessels with diameters large enough to pass a tumor clump of a given size and the proportion of clumps of that size within the venous effluent. Injection of tumor cells in clumps of 6 to 7 cells produces a significantly greater number of metaststic foci than does a similar number of single tumor cells; larger clumps produce significantly more metastatic foci than do smaller clumps matched for the number of cells. These studies verify the significance of tumor clumps in the metastatic process. It is suggested that tumor cell clumps arise locally within the vascular bed of the tumor.

Diffuse pulmonary ossification.

Diffuse pulmonary ossification (DPO) was a complication of "shock lung" after aortic valve replacement in a 52-year-old man. The relationship of DPO to shock lung is discussed. A possible mechanism for this complication is based on the development of a fibrin-platelet-fibroblastic interaction that may establish an intraalveolar lattice for collagen deposition by the fibroblast. The development of acidosis and mechanical forcer may potentiate fibroblastic transformation into an osteoblast. The mechanical forcer may influence the shape of the bone in the lung.

Pulmonary hypertension and systemic lupus erythematosus.

A combination of systemic lupus erythematosus (SLE) and fatal pulmonary hypertension occurred in a patient who, to our knowledge, had the highest pulmonary artery pressure (120/65 mm Hg) reported without any clinical or autopsy findings of pulmonary interstitial disease or vasculitis. The gradual development of pulmonary hypertension over years is a rare complication in patients with SLE.

Reactive eosinophilic pulmonary vascular infiltration in patients with spontaneous pneumothorax.

Prominent nonnecrotizing eosinophilic inflammation of muscular pulmonary arteries was seen in resected lung tissue from two patients with spontaneous pneumothorax. Other histologic features included reactive eosinophilic pleuritis (REP) and fibrobullous disease. Eosinophilic vascular infiltration was not contiguous to REP. In neither patient was there a specific and recognized cause of eosinophilic vasculitis. Both patients are without pulmonary symptoms 1 and 4 years after pneumothorax. Eosinophilic vascular infiltration initially suggested the diagnosis of allergic angiitis or pulmonary eosinophilic granuloma. These diagnoses were excluded by clinical and morphologic data. We subsequently reviewed 30 cases of lung tissue resected from patients with pneumothorax and found REP in 18 patients (60%) and mild pulmonary vascular and perivascular eosinophilia in five patients (17%). REP was present in all cases with eosinophilic vascular infiltration. We conclude that this eosinophilic vascular lesion is an unusual reaction in patients with REP and pneumothorax. Occasionally this lesion mimics allergic angiitis or eosinophilic granuloma. The pathogenesis is probably related to vascular transport of eosinophils to the injured pleural surface.

Micrometastases formation: a probabilistic model.

A mathematical model of the process of metastases is formulated in which the hematogenous metastatic process from a solid tumor is considered to consist of a series of stages. A mathematical expression is obtained for the probability that no metastases will have been established by a characteristic time interval after tumor initiation. The murine T241 fibrosarcoma that rapidly and reproduceably produces pulmonary metastases was studied. Estimates of parameters required for the expression of probability of metastases formation were derived experimentally. The probability remains close to one for a characteristic time at which point it drops to zero. This indicates that at least in this experimental system there is a predictable critical time period beyond which micrometastases are virtually certain to have been formed.

Respiratory tract pathology in patients with severe burns.

The histologic spectrum, pathogenesis, and clinical correlates of tracheobronchial and pulmonary lesions were studied by autopsy in six children and 27 adult burn victims. The burns covered a mean total body surface area of 57.7 +/- 23%. The mean survival time was 17.6 +/- 14.3 days. Patients over 60 years tended to survive longer than younger adults, but older patients had less extensive burns (P less than .01). Moderate or severe renal failure was an important clinical complication in 19 patients (58%). Diffuse alveolar damage (DAD) was observed in 16 patients, acute bronchopneumonia in seven patients, and necrotizing pneumonia in seven patients. Both DAD and pneumonia coexisted in 11 patients. Children most consistently developed pneumonia, 6 out of 6 versus 4 out of 17 younger adults (P less than .05). Factors which may have contributed to the pathogenesis of DAD included septicemia (12 patients), hypotension (nine patients), necrotizing pneumonia (six patients), and oxygen toxicity (four patients), in addition to the common presence of inhalational injury. The onset of DAD appeared late in eight patients with long survival periods, suggesting causal factors other than inhalational injury. However, survival rate did not differ in patients with or without DAD, and there was no correlation between DAD and the extent of burns. Airway lesions reflected the length of survival and showed the following sequence of changes: (1) mucosal necrosis and denudation, (2) acute inflammation and ulceration, and (3) squamous metaplasia. Endotracheal intubation injury and superinfection were confounding factors beyond the first few days of survival.

Pulmonary complications of the acquired immunodeficiency syndrome: a clinicopathologic study of 70 cases.

The pulmonary complications of 70 patients with the acquired immunodeficiency syndrome (AIDS) are reviewed. Pneumocystis carinii pneumonia (PCP), present in 67 per cent of the patients, was diagnosed by fiberoptic bronchoscopy with transbronchial biopsies in all of the patients except two adults, who required open lung biopsy, and two children, in whom the infection was detected only at autopsy. Other opportunistic infections, such as cytomegalovirus pneumonitis, mycobacterial infections, invasive candidiasis, toxoplasmosis, cryptococcosis, and histoplasmosis, were more difficult to diagnose by fiberoptic bronchoscopy. In only four cases were these conditions detected during life. Neoplasms and lymphoproliferative processes also presented diagnostic problems, and only one case each of Kaposi's sarcoma and lymphoid interstitial pneumonitis were detected by fiberoptic bronchoscopy. In four other cases these conditions, as well as two pulmonary lymphomas, diffuse large cell immunoblastic type, were detected only at autopsy. Sixty-eight per cent of the patients in this study died, usually with progressive intractable respiratory failure and pulmonary complications that had not been diagnosed during life, including potentially treatable diseases, such as bacterial pneumonias, PCP, nontuberculous mycobacteria, invasive candidiasis, toxoplasmosis, and invasive aspergillosis. The need for earlier detection of pulmonary complications in patients with AIDS is discussed.

Serum trypsin inhibitory capacity and Pi phenotypes. I. Methods and control values.

Serum trypsin inhibitory capacity determinations are of considerable value in detecting genetically determined types of obstructive pulmonary disease and hepatic disease. These determinations must frequently be followed by determination of protease inhibitor (Pi) phenotype in order to confirm the diagnosis. Piphenotyping has been a specialized and time-consuming procedure, and suggested improvements in the methodology and technics may make it more generally applicable as a clinical laboratory procedure. The prevalence of phenotypes other than MM in a group of 700 control sera from blood donors is reported as a baseline to evaluate typically American populations of mixed ethnic and racial characteristics. There are suggestive differences in prevalences of S and Z genes relating to ethnic stock and racial groups. It is important when comparing the prevalences of S and Z genes in diseasedpopulations to use control groups of similar ethnic and racial compositions. Pi phenotyping is a necessary laboratory procedure in the diagnosis of certain forms of genetically determined chronic obstructive pulmonary disease and hepatic disease. The distributions of all serum protease inhibitory capacity values and those for S and Z Pi phenotypes are shown.

Regional alveolar damage (RAD). A localized counterpart of diffuse alveolar damage.

Diffuse alveolar damage (DAD) is usually considered a generalized lung process. During five years the authors observed 83 patients with generalized DAD in 827 adult autopsies (10.1%) and 10 patients with identical, but localized, lesions. The authors propose the term regional alveolar damage (RAD) to designate localized "DAD." RAD was unilateral in six patients and most frequently involved the upper lobe. All ten patients had chronic systemic diseases and presented with life-threatening illnesses. The probable causes of RAD were multifactorial and included hypotensive shock, septicemia, pneumonia, hyperoxia, and pancreatitis. All patients developed respiratory failure, requiring supplemental oxygen and, in nine patients, mechanical ventilation. Chest roentgenograms revealed alveolar or combined alveolar and interstitial infiltrates that corresponded to the lesions found at autopsy. The reasons for localization of RAD within the lung are unclear, but the presence of proliferative lesions and frequent involvement of the upper lobe suggests that RAD is not simply an early phase of DAD and implicates additional pathogenetic factors.

Serum trypsin inhibitory capacity and pi phenotypes. II. Prevalence of alpha1-antitrypsin deficiency in an allergy population.

A series of 138 patients seen consecutively in an adult allergy clinic were studied to determine serum alpha1-antitrypsin (alpha1-AT) levels and protease inhibitor (Pi) phenotypes. These were compared with a control group of 700 healthy young adult blood donors. Both total serum trypsin inhibitory capacity (STIC) and alpha1-AT levels as determined by immunoelectrophoresis (IEP) were measured. Phenotypes were determined by antigen-antibody-crossed IEP. Alpha1-AT levels in the allergy group were not significantly different from control values. STIC in the allergy group was 1.34 +/- 0.28 mg. trypsin inhibited per ml. serum and in the controls, 1.32 +/- 0.28 mg. IEP values were 205 +/- vs. 200 +/- 36 mg. per dl. Similarly, no increase in Pi phenotypes known to be related to any disease state was observed. Since Pi phenotypes other than the most common MM are rare in Negro populations, phenotype data were corrected to include only Caucasian subjects. In the allergy group adjusted for racial composition we found 2.86% MZ, 5.72% MS; no SZ, SS or ZZ was detected. A comparable control group contained 3.68% MZ, 6.23% MS, 0.71% SZ-SS, but no ZZ Pi phenotype.

Pi-Z phenotypes in a pulmonary clinic. Their prevalence and physiologic state.

A series of 1,458 consecutive patients referred to the Cleveland Veterans Administration Pulmonary Clinic for pulmonary function studies was evaluated for alpha 1-antitrypsin deficiency by determination of serum trypsin inhibitory capacity (STIC). Protease inhibitor (Pi) phenotyping was performed on all sera with STIC values less than 1.6 mg/ml. The following non-MM phenotypes were found: 1FZ, 32MZ, 2ZZ, 3SZ, 5SS, 33MS, 21M. The prevalence of Pi Z heterozygosity is 2.74%. This figure is not significantly greater than that observed in a healthy population. A group ( n = 12) with heterozygous Z phenotype (MZ + SZ) was compared with a control (MM) group (n = 13) matched for age, race and smoking history from this same population. Our findings indicate similar deviations from predicted normal values in both control (MM) and Z-heterozygotic groups for physiologic tests of airway resistance, lung volumes, diffusing capacity, and static and dynamic compliance. There was no significant difference between MM controls and MZ heterozygotes in the physiologic variables measured.

Structure and function of small airways in health and disease.

During the last two decades, great strides have been made in our understanding of the functional aspects of airflow in the periphery of the lung. It seems that the small airways are the important site of obstruction in a variety of chronic respiratory disorders associated with airflow obstruction. This review deals with the anatomic and functional aspects of small airways in normal and diseased lungs. In particular, the basis of obstruction or narrowing that is not dependent on intrinsic airway lesion is reviewed. The variety of pathologic changes in small airways observed in these diseases are outlined along with physiologic tests that are currently used to detect dysfunction at a stage long before they produce symptoms or alter standard tests of lung function.

Delayed hypersensitivy and experimental interstitial pneumonitis.

The effects of prior sensitization with killed H37Ra tubercle bacilli on the pulmonary reaction to intravenous (IV) challenge with complete Freund's adjuvant (CFA) have been studied and were compared to reactions in nonsensitized CFA-challenged controls. Rabbits that died within 24 hours of challenge demonstrated acute arteritis prior to granuloma formation. Sensitized rabbits had a greater number of exudative cells in the pulmonary lavage fluid and a larger volume of parenchymal infiltrate than did comparable, nonsensitized controls at two and eight weeks. The exudate and infiltrate were diminished in both sensitized and nonsensitized rabbits at eight weeks. An obliterative, granulomatous arteritis was observed in both sensitized and nonsensitized groups receiving IV CFA and was not affected by the state of sensitivation. Granulomatous and collagenous parenchymal lesions regress in both sensitized and nonsensitized groups between two and eight weeks.

Immunocytochemical studies of APUD cells in airways: effects of nitrosodiethylamine and nitrogen dioxide.

The amine precursor uptake and decarboxylase (APUD) cells and neuroepithelial bodies (NEBs) in airways of adult rats have been studied by immunocytochemical methods for the presence of adrenocorticotropic hormone (ACTH), growth hormone (hGH), calcitonin, and bombesin in control animals and following exposure to nitrosodiethylamine and nitrogen dioxide (NO2). Calcitonin-like immunoreactivity (CLIR) is present in APUD cells of the trachea and bronchioles and in NEBs in the lung. Rats treated with nitrosodiethylamine and NO2 exhibit increased numbers of argyrophilic cells but no increase in cells containing specific intracytoplasmic CLIR. The presence of ACTH, hGH, and bombesin in respiratory tract APUD cells was not observed. These studies indicate that APUD cells in the trachea and bronchioles of adult rats harbor endocrine cells with immunohistochemical characteristics similar to C cells of the thyroid, and that these cell do not appear to be altered in number when rats are treated with agents known to produce an increase in APUD cells.

Neoplasms associated with pulmonary eosinophilic granuloma.

We found a high prevalence of pulmonary and extrapulmonary neoplasms in patients with pulmonary eosinophilic granuloma (PEG) who were studied at our institution. Among 21 patients with PEG, 10 (48%) had associated benign (one patient) or malignant (nine patients) tumors. Patients with tumors were older at the time of diagnosis of PEG (48.9 vs 34.5 years). Tumors included three lung carcinomas, one pulmonary carcinoid tumor, two lymphomas, five extrapulmonary carcinomas, and one mediastinal ganglioneuroma. Two malignant neoplasms developed in each of two patients. Six tumors preceded, three followed, and three occurred concomitantly with the diagnosis of PEG. Slides from eight PEG-associated tumors and 18 control neoplasms from patients without PEG were also stained immunohistochemically for S100 protein. Four PEG-associated (50%) and 11 control (61%) tumors contained S100 protein-positive interstitial cells. Our study suggests, but does not prove, that there may be more than a random association between PEG and neoplasms. Cigarette smoking, moreover, is an important risk factor for both PEG and lung carcinomas. Our immunohistochemical findings indicate that S100 protein-positive cells in tumors usually bear little or no relationship to PEG. In patients with an underlying malignant neoplasm, PEG simulates pulmonary metastases clinically and, occasionally, histopathologically.

Transbronchial biopsy in patients with pulmonary eosinophilic granuloma. Comparison with findings on open lung biopsy.

We evaluated the findings on transbronchial biopsy specimens in reference to open lung biopsy specimens from 12 patients with pulmonary eosinophilic granuloma. Features in transbronchial biopsy specimens were further contrasted to those of patients with interstitial fibrosis and nondiagnostic biopsy specimens for localized lesions. Transbronchial biopsy specimens were randomized and graded for histologic features and cellularity. Patients with eosinophilic granuloma had more macrophages (P < .05) but equivalent numbers of eosinophils, neutrophils, and Langerhans' cells compared with those of the other two groups. Only two endoscopic biopsy specimens were histologically diagnostic or highly consistent with eosinophilic granuloma. We conclude that the diagnosis of eosinophilic granuloma is possible on transbronchial biopsy but requires a high index of suspicion. The demonstration of Langerhans' cells by immunohistochemical staining for S100 protein is a useful adjunct. The low diagnostic yield for eosinophilic granuloma on transbronchial biopsy results from inadequate sampling and from the nonspecific appearance of discrete lesions in small tissue samples.

Obliterative central bronchitis due to mineral dust in patients with pneumoconiosis.

OBJECTIVE: We studied at autopsy a distinctive obliterative bronchitis in three persons with pneumoconiosis and hilar node fibrosis. METHODS: Lungs were evaluated macroscopically, microscopically, and with energy-dispersive spectroscopy. RESULTS: Chest roentgenogram demonstrated right middle lobe syndrome in one patient; bronchostenosis was seen at bronchoscopy in another. The stenotic sites were in perihilar bronchi and showed an upper lobe predominance. Fibrosis with silicotic nodules involved the bronchus, peribronchial tissue, and adjacent lymph nodes. Simple coalworkers' pneumoconiosis was observed in two patients; the third had complicated, mixed dust fibrosis. CONCLUSION: Obliterative bronchitis represents an unusual fibrotic response to free crystalline silica. The process may occur simultaneously in the adjacent lymph node and the bronchial wall; however, it need not be associated with complicated pneumoconiosis. Clinically, obliterative bronchitis may masquerade as bronchogenic carcinoma.