Search results for "Diffusing capacity"
showing 10 items of 13 documents
Familial pulmonary arterial hypertension by KDR heterozygous loss of function
2020
Beyond the major gene BMPR2, several new genes predisposing to PAH have been identified during the last decade. Recently, preliminary evidence of the involvement of the KDR gene was found in a large genetic association study.We prospectively analysed the KDR gene by targeted panel sequencing in a series of 311 PAH patients referred to a clinical molecular laboratory for genetic diagnosis of PAH.Two index cases with severe PAH from two different families were found to carry a loss-of-function mutation in the KDR gene. These two index cases were clinically characterised by low diffusing capacity for carbon monoxide adjusted for haemoglobin (DLCOc) and interstitial lung disease. In one family,…
Early Lung Function Abnormalities in Acromegaly.
2014
BACKGROUND: Acromegaly is an insidious disorder caused by a pituitary growth hormone (GH)-secreting adenoma resulting in high circulating levels of GH and insulin-like growth factor I (IGF-I). Respiratory disorders are common complications in acromegaly, and can severely impact on quality of life, eventually affecting mortality. OBJECTIVES: The present study aimed to explore structural and functional lung alterations of acromegalic subjects. METHODS: We enrolled 10 consecutive patients (M/F: 5/5) affected by acromegaly. In all patients, magnetic resonance imaging (MRI) revealed the presence of pituitary tumor. All patients underwent clinical, lung functional, biological, and radiological as…
Type B Niemann-Pick Disease: Findings at Chest Radiography, Thin-Section CT, and Pulmonary Function Testing
2005
To evaluate findings at radiography, computed tomography (CT), and pulmonary function testing in patients with type B Niemann-Pick disease.The study was approved by the institutional review board or ethics committee at each study site and was compliant with HIPAA at the U.S. site. Written informed consent was obtained from each patient or guardian and minor assent was obtained from all children before any study-related procedures. Pulmonary involvement in 53 patients (27 male and 26 female patients; age range, 7-65 years; mean age, 23.3 years) with type B Niemann-Pick disease was evaluated with imaging and pulmonary function tests. All patients underwent chest radiography and thin-section C…
Diffusion capacity of the lung in young and old endurance athletes
2013
Lung diffusion capacity (D LCO) declines with age. A significant proportion of older endurance athletes develop exercise-induced hypoxemia (SaO2<95%). We hypothesised that master endurance athletes have a lower D LCO than age-matched non-athletes. We recruited 33 control (16 young; 17 old) and 29 male endurance athletes (13 young; 16 old) during the World Masters Athletics Indoor Championships, 2012 (Jyvaskyla, Finland). To measure D LCO the participant exhaled to residual volume and then quickly inhaled to ≥ 90% total lung capacity from a gas source with 0.3% carbon monoxide. The D LCO and transfer coefficient (K CO) were corrected for the actual haemoglobin concentration. Spirometric func…
Muscle metabolic profile and oxygen transport capacity as determinants of aerobic and anaerobic thresholds
1988
Aerobic and anaerobic thresholds determined by different methods in repeated exercise tests were correlated with cardiorespiratory variables and variables of muscle metabolic profile in 33 men aged 20–50 years. Aerobic threshold was determined from blood lactate, ventilation, and respiratory gas exchange by two methods (AerT1 and AerT2) and anaerobic threshold from venous lactate (AnTLa), from ventilation and gas exchange (AnTr) and by using the criterion of 4 mmol·l−1 of venous lactate (AnT4mmol). In addition to ordinary correlative analyses, applications of LISREL models were used. The 8 explanatory variables chosen for the regression analyses were height, relative heart volume, relative …
Clinical aspects of the apparent diffusion coefficient in 3He MRI: results in healthy volunteers and patients after lung transplantation.
2007
Purpose To measure the apparent diffusion coefficient (ADC) after inhalation of hyperpolarized 3He in healthy volunteers and lung transplant recipients, and demonstrate the gravity dependence of ADC values. Materials and Methods Six healthy volunteers, 10 patients after single-lung transplantation, and six patients after double-lung transplantation were examined at 1.5T during inspiration and expiration. The inhalation of 300 mL of hyperpolarized 3He was performed with a computer-controlled delivery device. A two-dimensional fast low-angle shot (FLASH) sequence measured the 3He diffusive gas movement. From these data the ADC was calculated. Results The mean ADC was 0.143 cm2/second in healt…
Ventilation-Perfusion Ratio in Perflubron During Partial Liquid Ventilation
2010
BACKGROUND: Functional magnetic resonance imaging (fMRI) of fluorine-19 allows for the mapping of oxygen partial pressure within perfluorocarbons in the alveolar space (Pao(2)). Theoretically, fMRI-detected Pao(2) can be combined with the Fick principle approach, i.e., a mass balance of oxygen uptake by ventilation and delivery by perfusion, to quantify the ventilation-perfusion ratio (Va/Q) of a lung region: The mixed venous blood and the inspiratory oxygen fraction, which are equal for all lung regions, are measured. In addition, the local expiratory oxygen fraction and the end capillary oxygen content, both of which may differ between the lung regions, are calculated using the fMRI-detec…
Determination Of Pulmonary Parameters (V̇A, $$ {D_{{L_{{O^2}}}}} $$ ) From Arterial O2 and CO2 Partial Pressures During Exercise
1984
The arterial O2 and CO2 partial pressures mainly depend on the ventilation-perfusion ratio VA/Q and on the O2 diffusing capacity-perfusion ratio DLO2/Q. According to RAHN’s VA/Q concept, the dependence of the alveolar O2 and CO2 partial pressures on the ventilation-perfusion ratio can be determined graphically, and displayed in the form of a diagram (2,3). However, the application of the RAHN diagram is limited by the fact that during the passage of the blood through the lung capillaries, a complete adjustment of the capillary O2 partial pressure to the alveolar value frequently does not occur. This is particularly valid for gas exchange during exercise. For this case, the alveolar-endcapil…
Acute and sustained increase in endothelial biomarkers in COVID-19.
2020
Endothelial injury is related to poor outcomes in respiratory infections yet little is known in relation to COVID-19. Performing a longitudinal analysis (on emergency department admission and post-hospitalisation follow-up), we evaluated endothelial damage via surrogate systemic endothelial biomarkers, that is, proadrenomedullin (proADM) and proendothelin, in patients with COVID-19. Higher proADM and/or proendothelin levels at baseline were associated with the most severe episodes and intensive care unit admission when compared with ward-admitted individuals and outpatients. Elevated levels of proADM or proendothelin at day 1 were associated with in-hospital mortality. High levels maintaine…
Functional MR imaging of pulmonary ventilation using hyperpolarized noble gases.
2000
The current status of experimental and clinical applications for functional MR imaging of pulmonary ventilation using hyperpolarized noble gases are reviewed. 3-helium (3He) and 129-xenon (129Xe) can be hyperpolarized by optical pumping techniques such as spin exchange or metastability exchange in sufficient amounts. This process leads to an artificial, non-equilibrium increase of the density of excited nuclei which represents the source of the MR signal. Those hyperpolarized gases are administered mostly via inhalation, and will fill airways and airspaces allowing for ventilation imaging. Recent human studies concentrate on imaging the airways and airspaces with high spatial resolution. N…