scholarly journals A hybrid multibreath wash-in wash-out lung function quantification scheme in human subjects using hyperpolarized3He MRI for simultaneous assessment of specific ventilation, alveolar oxygen tension, oxygen uptake, and air trapping

2016 ◽  
Vol 78 (2) ◽  
pp. 611-624 ◽  
Author(s):  
Hooman Hamedani ◽  
Stephen Kadlecek ◽  
Yi Xin ◽  
Sarmad Siddiqui ◽  
Heather Gatens ◽  
...  
Respiration ◽  
2021 ◽  
pp. 1-10
Author(s):  
Marina Aiello ◽  
Marianna Ghirardini ◽  
Laura Marchi ◽  
Annalisa Frizzelli ◽  
Roberta Pisi ◽  
...  

<b><i>Background:</i></b> Alpha-1 antitrypsin deficiency (AATD) is a hereditary disorder involving lungs, characterized by low serum concentration of the protein alpha-1 antitrypsin (AAT) also called proteinase inhibitor (PI). Asthma is common in AATD patients, but there are only few data on respiratory function in asthmatic patients with AATD. <b><i>Objectives:</i></b> The aim of the study was to evaluate lung function in asthmatic outpatients with mutation in the <i>SERPINA1</i> gene coding for AAT versus asthmatic subjects without mutation. <b><i>Methods:</i></b> We performed the quantitative analysis of the serum concentration of AAT in 600 outpatients affected by mild to moderate asthma from the University Hospital of Parma, Italy. Fifty-seven of them underwent the genetic analysis subsequently; they were subdivided into mutated and non-mutated subjects. All the mutated patients had a heterozygous genotype, except 1 (PI*SS). We assessed the lung function through a flow-sensing spirometer and the small airway parameters through an impulse oscillometry system. <b><i>Results:</i></b> The values of forced vital capacity (% predicted) and those of the residual volume to total lung capacity ratio (%) were, respectively, lower and higher in patients mutated versus patients without mutation, showing a significantly greater air trapping (<i>p =</i> 0.014 and <i>p =</i> 0.017, respectively). Moreover, patients with mutation in comparison to patients without mutation showed lower forced expiratory volume in 3 s (% predicted) and forced expiratory volume in 6 s (L) spirometric values, reflecting a smaller airways contribution. <b><i>Conclusions:</i></b> In asthmatic patients, heterozygosity for AAT with PI*MZ and PI*MS genotypes was associated with small airway dysfunction and with lung air trapping.


1976 ◽  
Vol 51 (2) ◽  
pp. 185-188
Author(s):  
P. M. Tweeddale ◽  
R. J. E. Leggett ◽  
D. C. Flenley

1. Oxygen-binding, plasma and intra-erythrocytic pH, and haemoglobin, 2,3-diphosphoglycerate and inorganic phosphate concentrations were measured in sixty-two healthy non-smokers aged between 18 and 89 years. 2. P50 (oxygen tension at 50% oxygen saturation) expressed at plasma pH 7·40 and Pco2 5·33 kPa showed a positive correlation with age. 3. This correlation of P50 with age was closer when P50 was expressed at a constant intra-erythrocytic pH 7·20. On average P50 at intra-erythrocytic pH 7·20 increased from 3·59 kPa at 20 years to 3·96 kPa at 90 years of age. 4. 2,3-Diphosphoglycerate, inorganic phosphate, haemoglobin and mean corpuscular haemoglobin concentrations did not correlate with P50 or with age.


1964 ◽  
Vol 206 (4) ◽  
pp. 858-866 ◽  
Author(s):  
Wendell N. Stainsby ◽  
Arthur B. Otis

The effect of changes in blood flow and of blood oxygen tension on oxygen uptake of the in situ gastrocnemius-plantaris muscle group of the dog was examined. Oxygen uptake by resting muscle was not altered by changes in blood flow or blood oxygen tension except when these parameters were reduced below critical values. When the muscle group was contracting once per second, changes in blood oxygen tension were similarly without effect until a critically low value was reached. Although the contracting muscle used eight times as much oxygen per minute as resting muscle, the critical oxygen tension was lower than that for resting muscle. In an attempt to explain this observation the blood-tissue oxygen tension difference was estimated and used in the Krogh equation to calculate capillary density. The capillary density in contracting muscle was found to be much greater than in resting muscle and was about the same as the capillary density measured by others by histological techniques.


2011 ◽  
Vol 67 (5) ◽  
pp. 1332-1345 ◽  
Author(s):  
Hooman Hamedani ◽  
Stephen J. Kadlecek ◽  
Kiarash Emami ◽  
Nicholas N. Kuzma ◽  
Yinan Xu ◽  
...  

2020 ◽  
Vol 8 (2) ◽  
pp. 86-88
Author(s):  
David Brandt

Background: Extreme prematurity has been associated with exercise intolerance and reduced physical activity. We hypothesized that children with bronchopulmonary dysplasia (BPD) would be especially affected based on longterm lung function impairments. Therefore, the objective of this study was to compare exercise capacity and habitual physical activity between children born very and extremely preterm with and without BPD and term-born children. Methods: Twenty-two school-aged children (aged 8 to 12 years) born with a gestational age < 32 weeks and a birthweight < 1500 g (9 with moderate or severe BPD (=BPD), 13 without BPD (=No-BPD)) and 15 healthy termborn children (=CONTROL) were included in the study. Physical activity was measured by accelerometry, lung function by spirometry and exercise capacity by an incremental cardiopulmonary exercise test. Results: Peak oxygen uptake was reduced in the BPD-group (83 ± 11%predicted) compared to the No-BPD group (91 ± 8%predicted) and the CONTROL group (94 ± 9%predicted). In a general linear model, variance of peak oxygen uptake was significantly explained by BPD status and height but not by prematurity (p < 0.001). Compared to CONTROL, all children born preterm spent significantly more time in sedentary behaviour (BPD 478 ± 50 min, No-BPD 450 ± 52 min, CONTROL 398 ± 56 min, p < 0.05) and less time in moderate-to-vigorous-physical activity (BPD 13 ± 8 min, No-BPD 16 ± 8 min, CONTROL 33 ± 16 min, p < 0.001). Prematurity but not BPD contributed significantly to explained variance in a general linear model of sedentary behaviour and likewise moderate-tovigorous-physical activity (p < 0.05 and p < 0.001 respectively). Conclusion: In our cohort, BPD but not prematurity was associated with a reduced exercise capacity at school-age. However, prematurity regardless of BPD was related to less engagement in physical activity and more time spent in sedentary behaviour. Thus, our findings suggest diverging effects of prematurity and BPD on exercise capacity and physical activity.


2014 ◽  
Vol 27 (12) ◽  
pp. 1439-1450 ◽  
Author(s):  
Hooman Hamedani ◽  
Hoora Shaghaghi ◽  
Stephen J. Kadlecek ◽  
Yi Xin ◽  
Biao Han ◽  
...  

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