Degree Of Pulmonary Fibrosis Research Articles

Effect of lung, liver, and kidney toxicants on respiratory rate in the mouse

The intraperitoneal administration of either butylated hydroxytoluene (BHT) ± thoracic X-irradiation, or cyclophosphamide, and intravenous injection of oleic acid, resulted in lung injury and repair in BALB/c mice which could be assessed in unanesthetized animals by changes in respiratory rate (RR) using a total body plethysmograph. Studies with BHT ± X-rays, and cyclophosphamide found that the RR right before sacrifice (2 weeks after BHT and 3 weeks after cyclophosphamide) correlated well ( r = 0.19) with the degree of pulmonary fibrosis as measured by changes in hydroxyproline content. However, prior to this timepoint, there was a peak and trough in respiratory rate response that could not be correlated with the time course of fibrosis development in the BHT-X-ray model. In an effort to determine the influence of pulmonary edema and lung cell proliferation on respiratory rate changes, an agent (oleic acid) capable of producing lung injury followed by a high level of cellular proliferation with only minimal development of fibrosis was studied. These studies showed that good correlations were found on day 3 following injection (day of peak increase in respiratory rate) between respiratory rate and either lung wet weight ( r = 0.81) or the degree of cellular proliferation as measured by the incorporation of thymidine into pulmonary DNA ( r = 0.80). Liver (carbon tetrachloride) and kidney (mercuric chloride) toxicants, and starvation produced decreases or no changes in RR.

Correlation between the Tissue Response and Asbestos Fiber Content

Asbestos fiber concentration increases in proportion to the degree of pulmonary fibrosis as far as the moderate grade. No such correlation occurs with severe asbestosis, nor with the morphological form which the fibrosis assumes, and here secondary factors may be concerned. Electron microscopy suggests that optically visible fibers constitute a reasonably constant proportion of the total irrespective of the pathological reaction. Light microscopy may thus afford a guide to the total asbestos concentration. Finally, the development of mesothelioma, whether of the pleura or the peritoneum, appears to be unrelated to the concentration of coated or uncoated asbestos fibers residing in the lung.

The occurrence of pulmonaryfibrosis in children who had idiopathic respiratory distress syndrome

The long-term residua of the respiratory distress syndrome have not previously been assessed. Fifty-two infants who had clinical and x-ray evidence of RDS were examined at ages 6 months to 6 89 years, with evaluation of growth, development, and cardiopuhnonary problems. Posteroanterior and lateral chest x-rays were obtained; 19 infants were 6 to 11 months old~ 14 were 12 to 23 months, and 15 were over 24 months. All were apparently well, but 4 had clinical and x-ray findings of congenital heart disease With pulmonary hypervascularity and were excluded. Radiologic findings characteristic of pulmonary fibrosis were frequent, and have been graded as follows: (1) distinct linear densities radiating out from the hilum with peripheral branching, 12 children; (11) heavier, more generalized scarring extending far into the periphery, 17 children; (III) above findings plus overexpansion, extensive scarring, or pleural tenting, 6 children. The degree of pulmonary fibrosis could not be correlated with the clinical severity, birth weight, the duration or concentration of 02 therapy, the use of ventilatory aids, or the extent of x-ray changes in the acute stage. However, 21 of 29 children over 12 months of age had Class II or III pulmonary fibrosis; of these, only 6 had histories of intereurrent pulmonary disease, either bronchiolitis or asthma in each case. Of 48 infants who had RDS and have no evidence of eongenital heart disease, 48 per cent (23) have significant x-ray changes compatible with pulmonary fibrosis.

THE PATHOPHYSIOLOGY OF SCLERODERMA INVOLVING THE HEART AND RESPIRATORY SYSTEM.

Excerpt The lungs from patients with scleroderma show varying degrees of pulmonary fibrosis and medial hypertrophy of the pulmonary arterioles (1). However, little attention has been directed towar...

Pulmonary sarcoidosis

During the last nine years 123 patients with intrathoracic localization of sarcoidosis have been observed. There were six deaths from sarcoidosis. Thirty-nine patients showed varying degrees of pulmonary fibrosis, and eighteen patients among the survivors were left with significant respiratory difficulty. Intrathoracic lesions could be assigned to one of three broad chronologic stages according to the roentgen pattern present on the initial chest film: early, transitional and late. In the early stage, for those patients whose film showed enlarged mediastinal nodes without pulmonary lesions the outlook was best. It was not so favorable for patients whose films showed miliary nodulation of the lung fields and still less favorable when the film first showed a patchy bronchopneumonic pattern. Patients in the transitional and late fibrotic stages often showed disabling symptoms, and five of the six deaths caused by sarcoidosis were in patients with pulmonary lesions in these stages. Scalenus fat pad biopsies and the Nickerson-Kveim intracutaneous reaction are valuable diagnostic aids when involved tissue is not easily accessible for biopsy verification. Cortisone and corticotrophin generally act favorably upon intrathoracic sarcoidosis although the benefits usually prove temporary. In severe pulmonary insufficiency occasionally seen in the early stage and more often in the late fibrotic stage of pulmonary involvement, hormones may be the only means to tide a patient over the crucial period. In early stage lesions consisting of mediastinal lymphadenopathy, treatment is unnecessary because spontaneous regression is the rule. It is still debatable whether patients with asymptomatic miliary nodulation or bronchopneumonic patches in the lung fields should receive hormonal therapy in an attempt to forestall widespread pulmonary fibrosis. In chronic pulmonary sarcoidosis the effects of the hormones are variable. Sometimes symptomatic relief is dramatic and sustained. More often the relief is partial and relapse occurs promptly after the hormones are withdrawn. Pulmonary fibrosis may proceed even while the patient continues to receive the drugs. Indications for the treatment of extrathoracic lesions of sarcoidosis are listed.

Pulmonary Fibrosis: Clinical Aspects

MY CONTRIBUTION to this symposium on pulmonary fibrosis will be short, since my only object is to try to correlate the x-ray, pathological, and clinical findings. I believe that Dr. Mallory2 has made a distinct contribution to our knowledge of pulmonary fibrosis and when we accept his group of cases it changes our previous ideas of classification. From the clinician's standpoint there are now four groups of cases in which varying degrees of pulmonary fibrosis play an important part: first, those with known etiology (tuberculosis, silicosis, and radiation therapy); second, the group with either asthma or emphysema, where the fibrosis seems to be the result of organizing pneumonia; third, Dr. Mallory's cases of fibrosing granulomata; and fourth, a miscellaneous group of unusual conditions. From the standpoint of the practitioner of internal medicine, the group with “senile emphysema” is probably the largest and most important. The age of onset is usually in the fifty's. Acute respiratory infection is often the apparent inciting factor. Dyspnea with exertion is the outstanding symptom, and there are varying degrees of chronic bronchial infection and bronchial spasm. In many of these cases of emphysema, as well as in a large proportion of those with extensive fibrosis, cor pulmonale (right-sided heart failure) plays a definite part, but the severity of symptoms is often independent of the degree of pulmonary fibrosis, and cor pulmonale of alarming proportions may occur in cases with very little scar tissue. Many cases of asthma also fall into this group One of our favorite cases of clinical “idiopathic pulmonary fibrosis” was that of a woman who had had asthma since childhood; from the postmortem standpoint, this was classified as asthma with very extensive organized pneumonia. In reviewing the slides recently Dr. Mallory did not admit it to the group of fibrosing granulomata. In practically all of these cases of asthma and emphysema, such fibrosis as develops seems to be the result of organized pneumonia. The third group is one which in the past we have called “idiopathic pulmonary fibrosis,” but Dr. Mallory has shown that the majority of these cases can be placed in a group of granulomata of the lung which histologically resemble sarcoid disease. For the time being I believe that many cases in which we can safely rule out organized pneumonia should be considered as fibrosing granulomata. This leaves for the fourth group a few miscellaneous unusual cases. We have, for example, cases resembling “fibrosis,” which have proved to be bronchiolectasis, where there is a marked dilatation of the smaller bronchioles with very little dilatation or infection in the larger bronchi. Now let us go back to Dr. Mallory's approach to the problem of “idiopathic pulmonary fibrosis” and his 6 cases of a granulomatous process, histologically similar to sarcoid disease, which have gone on to pulmonary fibrosis with resulting death.

The Method of Expressing the Silica Content of the Lung

Withincreasing knowledge of the effects of inhaled dusts upon the lungs has come an increase in the number of cases of Workmen's Compensation in which pulmonary disease is attributed to exposure to this form of risk during employment. Where a post-mortem examination has been made, and the opinion of a pathologist is sought, no difficulty is encountered in those cases of silicosis in which the disease is well developed, since the lesions are characteristic and easily recognised. The position, however, is by no means so easy where lesser degrees of pulmonary fibrosis are present and, in particular, where it becomes necessary to try to assess the bearing which these may have upon the susceptibility to, and the progress of, intercurrent pulmonary disease—for example lobar pneumonia. In these difficult circumstances recourse is frequently had to the chemical estimation of the quantity of silica recoverable from samples of lung. Certain standards have been set up, and the presence of silica in quantities in excess of the “normal” forms valuable corroborative evidence that a pulmonary fibrosis is attributable to its influence, where the subject in question has been exposed to this risk in his employment, and on the other hand the absence of an excess of silica is evidence that any pathological condition in the lung is due to other causes.

Pathology and Bacteriology at Leeds

THE annual report for 1932 of the Department of Pathology and Bacteriology, University of Leeds, by Profs. M. J. Stewart and J. W. McLeod, recently issued, surveys the teaching and research work carried out in the laboratories. The research work includes investigations on industrial pulmonary diseases, studies in renal function, and on different cultural types of the diphtheria bacillus. In four haematite miners an extreme degree of pulmonary fibrosis was detected. In cancer research, Dr. Bonser has obtained results strongly suggesting that it is possible to breed a race of mice which respond very early to tumour induction by means of tar.