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PubMed1984

Reduced lung function in leukaemia patients undergoing bone marrow transplantation.

20 patients with leukaemia in remission or early relapse received an allogeneic bone marrow graft. Patients were conditioned according to Seattle protocol with high dose cyclophosphamide and total body irradiation to a total dose of 8 Gray to the lungs delivered by a 6 MV linear accelerator at a dose rate of approximately 0.06 Gray/min. As prophylaxis against the graft versus host reaction, methotrexate and/or cyclosporin A were given. Lung function was studied prior to treatment and every 3 months thereafter. Before treatment a marked decrease was seen in the CO diffusion capacity when compared to the predicted value, while the flow volume relationships were within normal limits. The cause of this is unknown, but may be due to previous infections and the cytostatic treatment given. After bone marrow transplantation, a further irreversible decrease was seen in the CO diffusion capacity and vital capacity indicating an additive effect of the lung irradiation.

Adolescent↗
PubMed1990

Evaluation of elastase and antielastase balance in patients with chronic bronchitis and pulmonary emphysema.

On the basis of the "protease-antiprotease imbalance" theory for the pathogenesis of pulmonary emphysema, we hypothesized that measurement of elastase burden and antielastase capacity in the alveolar space might correlate with emphysema. To evaluate this, the severity of emphysema, the elastase burden, and the elastase inhibitory capacity were estimated in 28 patients with chronic bronchitis and variable degrees of emphysema, none of whom had congenital deficiency of alpha-1-protease inhibitor, and all of whom underwent bronchoalveolar lavage. Emphysema was assessed by both computed tomography and diffusing capacity. To examine "elastase burden," elastase:alpha-1-protease inhibitor complex and free elastase activity in alveolar lavage fluids were measured. To evaluate "antielastase" capacity, elastase inhibiting capacity in alveolar lavage fluid was measured. Elastase burden correlated directly and antielastase capacity correlated inversely with emphysema. These data provide direct support for the "protease-antiprotease imbalance" theory of emphysema in a group of smokers without congenital deficiency of alpha-1-protease inhibitor.

Adult↗
PubMed1986

The effect of transfusion on lung capacity, diffusing capacity, and arterial oxygen saturation in patients with thalassemia major.

Our previous cross-sectional study of patients with thalassemia major suggested progressive lung changes characterized by low total lung capacity, hypoxemia, and elevated transfer factor for carbon monoxide. We reevaluated nine of the patients for three reasons: to determine the relationship of the previous findings to the immediate effects of blood transfusion; to assess the longitudinal progression of the lung changes; and to evaluate the effect of splenectomy on lung volume changes in these patients, all of whom underwent splenectomy in the interval between the two studies. We found that during the 5- to 6-yr period between studies total lung capacity had decreased significantly (p less than 0.05) from a mean 86% predicted to a mean 79% predicted. However, vital capacity increased significantly (p less than 0.05) from a mean 81% predicted to 88% with no significant change in functional residual capacity. There was no significant immediate effect of transfusion on total lung capacity, vital capacity, or functional residual capacity. However, the diffusion constant for carbon monoxide increased significantly (p less than 0.005) immediately following transfusion and there was a positive correlation between the increase and the amount of blood transfused (r = 0.74, p less than 0.05). Arterial oxygen saturation was below 95% in five of eight patients and increased significantly with transfusion (p less than 0.05). We conclude: 1) thalassemia major and/or its treatment is associated with hypoxemia and a progressive reduction in total lung capacity. 2) Despite the progressive reduction in total lung capacity, splenectomy in patients with thalassemia major increases expiratory reserve volume and thereby increases vital capacity.

Adolescent↗
PubMed1995

Persistent reduction in lung function after Pneumocystis carinii pneumonia in AIDS patients.

By means of serial lung function tests we examined the changes in lung function and possible pulmonary long-term sequelae in AIDS patients with a primary episode of Pneumocystis carinii pneumonia (PCP). A total of 19 patients had lung function tests performed prospectively from the time of PCP diagnosis, at 7 days, 14 days, 1, 2, 3, 4.5, 6 and 9 months after PCP. Forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) were both reduced to a median of 61% of predicted at PCP diagnosis, and were normalized within 1 month and 1 week respectively. The median pulmonary diffusing capacity for carbon monoxide (DLCO) was severely reduced to 43% of predicted during the acute infection. Although DLCO improved significantly during the first 2 months, it remained reduced at a median DLCO of 64% of predicted 9 months after PCP. We conclude that despite a general improvement in lung function during the first 2 months following the PCP diagnosis, ther was a persistent reduction in DLCO up to 9 months following PCP. The pathological mechanisms causing this reduction remain to be established.

AIDS-Related Opportunistic Infections↗
PubMed1984

Pulmonary involvement in chronic pancreatitis.

Although the association between acute pancreatitis and pleuropulmonary damage is well documented, so far no information on lung function in patients with chronic pancreatitis is available. In this study functional, radiological, and clinical investigations have been carried out in 42 patients affected by chronic calcific pancreatitis (CCP) and in 50 controls in a case-control study. An impairment of pulmonary diffusing capacity has been detected in CCP patients, while all the parameters of ventilatory function were not different from controls. This finding suggests the presence of early lung parenchymal damage in chronic pancreatitis secondary to either emphysema or pulmonary fibrosis.

Adult↗
PubMed1985

Chronic interstitial pulmonary fibrosis following Mycoplasma pneumoniae pneumonia.

An unusual case of chronic interstitial fibrosis that developed as a sequela of Mycoplasma pneumoniae pneumonia is described. Predominant manifestations included progressive exertional dyspnea, shortness of breath, persisting lung infiltrates, low lung volumes, and low pulmonary diffusing capacity. Open lung biopsy one year after the acute stage of mycoplasma pneumonia revealed focal interstitial fibrosis with early pleural thickening, hypertrophic alveolar lining cells, and peribronchiolar lymphoid cell infiltrates. Improvement in clinical manifestations, radiologic findings, and pulmonary function results occurred with steroid therapy.

Adult↗
PubMed1988

[Pregnancy and the respiratory function].

The respiratory function of pregnant women is changed for more than one reason. There is a mechanical effect due to the increase in the uterine volume and the elevation of the diaphragm. However, there are only modest functional consequences, because the pulmonary volumes are only little changed, with the exception of a reduction in the functional residual capacity. Bronchial permeability is unaltered due to the balancing of constrictors (mechanical, hypocapnia) and dilators (hormonal influences). As regards pulmonary haemodynamics, the hypovolaemia of the pregnant woman has no repercussions on pulmonary vascular pressure. Gas exchange and alveolar-capillary diffusion are normal or even improved as a consequence of chronic hyperventilation. The latter is the most important functional change, sometimes expressed as a sensation of dyspnoea. The origin of this hyperventilation relates to the diminution of the threshold of sensibility in the respiratory centres to CO2 due to the effect of raised progesterone levels.

Female↗
PubMed1978

Progressive interstitial lung disease from prolonged methotrexate therapy.

Progressive interstitial fibrosis with roentgenographic honeycombing developed in the case of a psoriatic patient who had been on a regimen of methotrexate for 18 years. Examination revealed a combined restrictive and obstructive defect in pulmonary mechanics and severe compromise of gas transfer across the pulmonary alveolar-capillary membrane. Improvement in the level of arterial blood gases and pulmonary diffusing capacity occurred after discontinuation of methotrexate therapy. Interstitial fibrosis of the lung is a potential complication of methotrexate therapy for psoriasis.

Aged↗
PubMed1994

Indications of reduced pulmonary function in type 1 (insulin-dependent) diabetes mellitus.

Abnormalities of pulmonary function tests have been described in type 1 (insulin-dependent) diabetes mellitus (IDDM). To better characterise such abnormalities and to verify whether these latter are associated with the presence of diabetic microvascular disease we compared 23 non-smoking patients who had IDDM with 24 non-smoking healthy control subjects strictly matched for sex, age, and body mass index. Compared with controls, diabetic patients had a reduced forced vital capacity (FVC) (87.5 +/- 13.1% vs. 96.4 +/- 13.6% of the predicted; P = 0.03) and forced expiratory volume in 1 s (FEV1) (90.5 +/- 17.7% vs. 101.2 +/- 13.2% of the predicted; P = 0.02). While within the group of patients the presence of retinopathy and autonomic neuropathy were not associated with modifications of pulmonary function tests, those with altered urinary albumin excretion rate (AER > or = 20 micrograms/min; range 21-589) (n = 7) had a significantly lower pulmonary diffusion capacity (DLCO) than the 16 normoalbuminuric subjects (62.6 +/- 7.2% vs. 88.7 +/- 20.1% of the predicted; P = 0.01). Moreover, in the group of patients, DLCO was inversely related with AER (r = -0.43; P = 0.04). In conclusion, IDDM is characterised by reduced FVC and FEV1, while a significant decrease in DLCO may be considered as selectively associated with renal disease.

Adult↗
PubMed1994

[The oxygen pathway: how well-built is the respiratory system?].

The question is explored of how the structural systems that constitute the pathway for oxygen from the air through the lung and the circulation of blood to the mitochondria in muscle cells affect the O2 flow rate, and whether their quantitative structural characteristics conform to the hypothesis of symmorphosis which postulates a match of structural design to overall functional demand. By combining physiological and morphometric studies, it is first demonstrated that the diffusing capacity of the human lung is slightly larger than that needed for maximal O2 uptake. Comparative studies of small and large species (from the mouse to the cow) and of athletic and sedentary species pairs (such as horses and cows) show that the design parameters of muscle cells and their mitochondria, of the capillaries, and of blood and circulation are coadjusted to O2 demand by the muscles during exercise. In contrast, the lung is only partially adjusted to this level of demand, a fact which may be related to the slight excess capacity of its gas exchanger. In the organ that forms the interface to the environment this may be a desirable safety factor.

Animals↗
PubMed1989

Lung function in essential mixed cryoglobulinemia: a short-term follow-up.

Lung involvement in essential mixed cryoglobulinemia (EMC) has been recently described. In order to assess whether patients with EMC experience an accelerated deterioration of lung function, nineteen patients (17 females, 2 males; 49.6 +/- 6.6 years) underwent a short-term follow-up of lung function, chest X-ray and serologic investigations. Reduction of forced expiratory flows and presence of roentgenologic signs of interstitial involvement were confirmed in the baseline evaluation. In addition, a decrease of diffusing capacity was shown. After a mean interval of 15 months, no significant change in lung function was found, with the exception of decrease in maximal expiratory flow at 50% of forced vital capacity, total lung capacity, functional residual capacity, coefficient of transfer of CO. A slight decrease of hemolitic complement (CH50) and of complement fraction (C3) was also observed. This study suggests that patients with EMC tend to have an involvement of pulmonary interstitial space, possibly related to immune complex deposition, but they do not show a severe decline of lung function. Periodical assessment of lung function and chest X-ray is, however, worthwhile.

Adult↗
PubMed1991

What factors explain racial differences in lung volumes?

In order to examine the physical characteristics that may determine racial differences in lung volumes, we studied healthy, nonsmoking Caucasian, Chinese and Indian males of similar ages (range 18-51 yrs). We measured spirometric function, flow volume curves, lung volumes, inspiratory and expiratory muscle pressures, alveolar distensibility and diffusing capacity, together with height, weight and fat free mass. Chest shape was measured using radiographs. The mean total lung capacity and vital capacity in the Caucasian group, expressed as percentage predicted, were 5 and 10% higher than in the Chinese group and 17 and 20% higher than in the Indian group. Chinese values for these measurements were 12 and 10% greater than Indian. We found that Caucasians had higher fat free masses, higher inspiratory and expiratory muscle pressures and wider chests than the other races. The Caucasians and Chinese had longer chests than the Indians. There was no difference in alveolar distensibility or in the diffusion coefficient between the groups. These findings suggest that Caucasians have larger lung volumes than Chinese and Indians because they have increased numbers of alveoli and physically larger chest cavities, and not because of greater alveolar distensibility. Chest dimensions, together with height and race explained 90% of the variation in forced vital capacity and 86% of the variation in total lung capacity. Height multiplied by fat free mass, a "physique factor", previously suggested as the best predictive factor for forced vital capacity in Caucasians, did not account for much of the variation in forced vital capacity between Caucasians and Indians, presumably because it takes no account of differences in chest dimensions.

Adolescent↗
PubMed2003

Helium-3 MRI diffusion coefficient: correlation to morphometry in a model of mild emphysema.

Hyperpolarised gases have been most recently used in magnetic resonance imaging to demonstrate new image-derived pulmonary function parameters. One of these parameters is the apparent diffusion coefficient, which reflects the sizes of the structures that compartmentalise gas within the lung (i.e. alveolar space). In the present study, noninvasive parameters were compared to microscopic measurements (mean linear intercept and mean alveolar internal area). Nonselective helium-3 gas density coronal ex vivo images and apparent diffusion maps were acquired in control and elastase-induced panacinar emphysema rats. Total lung capacity was considered the reference for both imaging experiments and lung fixation. A mild degree of emphysema was found based on mean linear intercept (134 +/- 25 microm) versus control (85 +/- 14 microm). The apparent diffusion coefficients were significantly different between the two groups (0.18 +/- 0.02 and 0.15 +/- 0.01 cm2 x s(-1) for elastase and control, respectively). A significant correlation between the apparent diffusion coefficient and corresponding morphometric parameters in mild emphysema was demonstrated for the first time. This study opens the possibility of estimating absolute airspace size using noninvasive techniques.

Animals↗
PubMed1995

Asbestos-induced visceral pleural fibrosis reduces pulmonary compliance.

To determine the nature of respiratory functional impairment caused by asbestos-induced visceral pleural fibrosis (VPF) and to discover which pulmonary physiological variable best reveals it, we examined 59 asbestos-exposed construction workers having asbestos-related changes on chest radiographs. Computed tomography scans of the thorax were also performed. Visceral pleural fibrosis was diagnosed in 29 subjects: seven had only VPF, 17 had VPF and pleural plaques, and five had VPF, plaques, and asbestosis. In subjects without VPF, 23 had plaques, six had plaques and asbestosis, and one had only minor fibrotic parenchymal changes insufficient for a diagnosis of asbestosis. Flow-volume spirometry, body plethysmography, static and dynamic compliance, and pulmonary diffusing capacity for carbon monoxide were measured. The subjects with VPF had significantly lower static (p = 0.005) and dynamic (p = 0.007) compliance values than those without. Other respiratory function variables failed to show any significant differences. We conclude that the measurement of static and dynamic compliance is a useful method in assessing pulmonary function impairment caused by visceral pleural fibrosis.

Adult↗
PubMed2000

Higher arterial oxygen saturation during submaximal exercise in Bolivian Aymara compared to European sojourners and Europeans born and raised at high altitude.

Arterial oxygen saturation (SaO(2)) was measured at 3,600-3,850 m by pulse oximetry at rest and during submaximal exercise in three study groups: 1) highland Aymara natives of the Bolivian altiplano (n = 25); 2) lowland European/North American sojourners to the highlands with at least 2 months of acclimatization time to 3,600 m (n = 27); and 3) subjects of European ancestry born and raised at 3,600 m (n = 22). Aymara subjects maintained approximately 1 percentage point higher SaO(2) during submaximal work up to 70% of their maximal work capacity, and showed a smaller rate of decline in SaO(2) with increasing work compared to both European study groups. The higher-exercise SaO(2) of Aymara compared to Europeans born and raised at 3,600 m suggests genetic adaptation. The two European study groups, who differed by exposure to high altitude during their growth and development period, did not show any significant difference in either resting or exercise SaO(2). This suggests that the developmental mode of adaptation is less important than the genetic mode of adaptation in determining exercise SaO(2). A weak correlation was detected (across study groups only) between the residual forced vital capacity (FVC) and the residual SaO(2) measured at the highest level of submaximal work output (P = 0.024, R = 0.26). While firm conclusions based on this correlation are problematic, it is suggested that a part of the higher SaO(2) observed in Aymara natives is due to a larger lung volume and pulmonary diffusion capacity for oxygen. Results from this study are compared to similar studies conducted with Tibetan natives, and are interpreted in light of recent quantitative genetic analyses conducted in both the Andes and Himalayas.

Adaptation, Physiological↗