New pathological findings in emphysema of childhood: 1. Polyalveolar lobe with emphysema
TL;DR: A detailed and quantitative study of the airways, alveoli and arteries was carried out on the left upper lobe removed because of shortness of breath, finding that emphysema, accepted today as a structural diagnosis, was not present and the condition was a `giantism' of the alveolar region.
Abstract: A new pathological entity is here described—a polyalveolar lobe with or without emphysema—giving rise to the clinical features of childhood lobar emphysema. A detailed and quantitative study of the airways, alveoli and arteries was carried out on the left upper lobe removed because of shortness of breath, thought to be due to `childhood lobar emphysema9. The child was 17 days old and the radiograph showed hypertransradiancy of the left lung. The alveolar number was increased five-fold. Alveolar size was normal, so it was found that emphysema, accepted today as a structural diagnosis, was not present. The increase in alveolar number seemed confined to the apical, posterior, and anterior segments, the lingula being unaffected. By contrast, the airways and arteries were normal for age in number, size and structure, suggesting that the condition was a `giantism9 of the alveolar region. The blood flow was probably too low for the lobar volume; certainly the excessive alveolar number could not be due to increase in blood flow. In two further specimens, previously dissected, a similar polyalveolar condition was found, associated with emphysema. The patients were older at the time of surgical resection and the emphysema may have developed post-natally. In all three cases the radiographic features had suggested emphysema. It is suggested that the condition be called `polyalveolar lobe9, `with emphysema9 or `without emphysema9 being added as a separate item to the description.
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TL;DR: From a case of congenital diaphragmatic hernia the pattern of growth of the airways, alveoli, and pulmonary arteries of both lungs, each hypoplastic, has been analysed quantitatively.
Abstract: From a case of congenital diaphragmatic hernia the pattern of growth of the airways, alveoli, and pulmonary arteries of both lungs, each hypoplastic, has been analysed quantitatively. The impairment of growth for each type of structure is not necessarily the same and differs in each lung. Airway and alveolar numbers are both greatly reduced, although the latter are more nearly normal when related to the number of terminal bronchioli in the lung. In each lung the size of the pulmonary artery at the hilum is appropriate to the lung volume but small for the age of the child. Muscle is found in much smaller arteries than is normal but not to a more peripheral level.
The way the lungs in a case of congenital diaphragmatic hernia might grow after surgical correction of the hernia is discussed and a plea made for respiratory physiological studies in such cases.
378 citations
TL;DR: A malformation sequence based on airway obstruction during development is proposed as a unifying pathogenetic mechanism for some seemingly unrelated lesions.
364 citations
TL;DR: It is suggested that this particular group of patients remained refractory to all current modes of therapy because of these severe structural pulmonary vascular changes and does not merely represent a failure of the fetal pattern to regress.
281 citations
Journal Article•
TL;DR: A gradual increase in arterial wall thickness was demonstrated and also progressive extension of muscle into smaller and more peripheral vessels than normal and maximum increase was reached by 14 days of exposure though changes were apparent after only 3.5 days.
Abstract: Rats have been kept in a hypobaric chamber, and thus hypoxic, for up to 28 days in order to study the structural changes in the pulmonary arteries during the development of pulmonary hypertension. Rats were studied after 3, 5, 7, 10, 14, 21 and 28 days at a pressure of 380 mmHg. Right ventricular hypertrophy was demonstrated after 5 days in the hypoxic environment but increased up to 10 days. After pulmonary arterial injection microscopic counts of small arteries showed that vessels up to 200 mum external diameter were gradually "lost", reducing the ratio of arterial to alveolar number significantly by 14 days. No vestiges of these vessels were found with light microscopy. At the same time a gradual increase in arterial wall thickness was demonstrated and also progressive extension of muscle into smaller and more peripheral vessels than normal. In both these features maximum increase was reached by 14 days of exposure though changes were apparent after only 3. Similar changes have been found in patients with cystic fibrosis and chronic bronchitis using the same measuring techniques.
251 citations
TL;DR: In lungs from 18 children aged between birth and 11 years the development of the branching pattern and structure of the pulmonary arteries, particularly the intralobular and intra-acinar, has been quantitatively analysed after injection with a radio-opaque medium.
Abstract: In lungs from 18 children aged between birth and 11 years the development of the branching pattern and structure of the pulmonary arteries, particularly the intralobular and intra-acinar, has been quantitatively analysed after injection with a radio-opaque medium. Up to 18 months of age as new alveolar ducts appear conventional arterial branches develop within the acinus: supernumerary arteries increase in number up to 8 years as new alveoli form. Both types increase in size with age. After birth there is an immediate drop in wall thickness of the vessels below 200 μm diameter while the larger vessels take up to 4 months to fall to adult thickness, suggesting two types of response—one dilatation, the other a growth rate change of the muscle cells. During childhood muscle cell formation in the intra-acinar arteries lags behind increase in artery size so that during childhood few muscular arteries are found within the acinus. The functional significance of these changes is discussed.
224 citations
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TL;DR: A new principle is derived from mathematical considerations which will allow the calculation of the number of bodies contained in the unit volume by counting the numberOf transections on the unit ...
Abstract: A new principle is derived from mathematical considerations which will allow the calculation of the number of bodies contained in the unit volume by counting the number of transections on the unit ...
788 citations
TL;DR: The purpose of this paper is to show how the methods of quantitation as applied to the lung, but the methods mentioned are capable of adaptation to almost any organ.
Abstract: Clinico-pathological correlation has always been one of the main aims of the morbid anatomist. However, although clinical physiologists have for many years expressed their results in a quantitative form, pathologists have progressed mainly, though not entirely, along a descriptive path. Descriptive pathology has reached a high degree of refinement with the study of ultra-structure by the electron microscope and the probing of cellular chemistry by histochemical methods. Little interest has been shown in the field of quantitative morphology, although a quantitative study of gross and microscopic pathology, correlated with the findings of physiopathologists, might well yield much useful information. Thompson (1917) pointed out many applications of this approach to general biology, and recently Grant (1961) has drawn attention to the importance of this type of study in cardiac pathology and has referred to the work of Linzbach (1960). This paper is concerned with the methods of quantitation as applied to the lung, but the methods mentioned are capable of adaptation to almost any organ. Pulmonary physiology is a subject which has undergone enormous advances over the past 30 years, mainly since the introduction of cardiac catheterization as a safe clinical procedure by Cournand and Ranges (1941). The relatively slow progress of pulmonary pathology is probably due to inadequate descriptions of the various aspects of emphysema and chronic lung disease. This has been remedied largely by the work on chronic bronchitis of Reid (1954) and the description of centrilobular emphysema by Leopold and Gough (1957). What is needed now is precise information concerning volumes of normal and abnormal regions of the lung, the surface area of the airtissue interface, and the number of the various units, such as alveoli and alveolar ducts, in normal and emphysematous lungs. The purpose of this paper is to show how these measurements can be
579 citations
TL;DR: Postnatal development of the human lung occurred, at least until the age of 7 years, with new branches of the peripheral part of the bronchial tree being formed by " centripetal and centrifugal " processes occurring at the same tinme.
Abstract: There are two opposed views on the problem of postnatal lung growth. The first (Short, 1950) considers that the lung at birth has its full complement of alveoli and that further growth takes place by an increase in linear dimensions of existing units. The second, as summarized by Emery and Mithal (1960), proposes that growth occurs by an increase in the number of respiratory units. Willson (1922) investigated two lungs by serial section and wax reconstruction. He found a dichotomous branching system of the air passages and also that the bronchioles do not decrease in diameter as the periphery is approached. He thought that the lung of a child, one case " under 13 years of age," was as complex as that of an adult. Broman (1923) suggested that in higher mammals, including man, the number of alveoli at the time of birth had not reached its adult value. In a further investigation into this problem Willson (1928) observed that there was more connective tissue between the air spaces at birth than at later stages of childhood or in the adult. He concluded that postnatal development of the human lung occurred, at least until the age of 7 years, with new branches of the peripheral part of the bronchial tree being formed by " centripetal and centrifugal " processes occurring at the same tinme. Barnard and Day (1937) found that the lung did not change essentially in structure after the sixth month of foetal life. They inflated foetal lungs artificially by suction in a closed chamber, with or without simultaneous perfusion of the pulmonary artery, and noted that it was impossible to transform the appearance of immature lungs. During and after the sixth month such procedures resulted in the lung resembling that of an adult to varying degrees. Short (1950), in an exhaustive study of lung growth in rabbits, was the first to employ a truly quantitative approach. He estimated the surface area of the air-tissue interface of lungs at various ages. His main interest was in the continuity or discontinuity of the lining alveolar epitbelium. He
425 citations
TL;DR: A statistical survey of the growth of the human terminal respiratory unit during the latter half of intrauterine life and through childhood.
Abstract: Until recently the child's lung was considered to be a miniature of the adult lung (Kolliker, 1881). Broman (1923) demonstrated that the bronchial tree underwent further branching after birth (in cows), that foetal alveolar ducts became bronchioles and that there was a postnatal increase of over 30% in the number of subpleural vesicles in the middle lobe of the right lung in rabbits and man. Much work has been done on the minute structure of the terminal pulmonary units, of which Miller's book (Miller, 1947) is a landmark. Most of the research has been carried out on animals and no one, as far as we are aware, has worked on more than 15 children's lungs. No attempt appears to have been made to estimate postnatal alveolar growth on a quantitative basis. The present report records a statistical survey of the growth of the human terminal respiratory unit during the latter half of intrauterine life and through childhood.
395 citations