COPD: Journal of Chronic Obstructive Pulmonary Disease, 2013
Our aim was to describe the population-based distribution of several COPD multi-dimensional indic... more Our aim was to describe the population-based distribution of several COPD multi-dimensional indices and to evaluate their relationship with daily physical activity, co-morbidity, health status and systemic inflammatory biomarkers. From a population-based sample of 3,802 subjects aged 40-80 from the EPI-SCAN study, 382 subjects (10.2%) with a post-bronchodilator FEV1/FVC<0.7 were identified as COPD. Smoking habits, respiratory symptoms, quality of life, co-morbidities, lung function and inflammatory biomarkers were recorded. Health status and daily physical activity were assessed using the EQ-5D and LCADL questionnaires, respectively. The new GOLD grading and the BODE, ADO, DOSE, modified DOSE, e-BODE, BODEx, CPI, SAFE and HRS indices were determined. A notable dispersion in the total scores was observed, although 83-88% of the COPD patients were classified into the mildest level and 1-3% in the most severe. The SAFE index was the best independent determinant of daily physical activity; the SAFE and ADO indices were associated with presence of co-morbidity; and the SAFE and modified DOSE indices were independently related to health status. The systemic biomarkers showed a less consistent relation with several indices. In a population-based sample of COPD patients, the SAFE index reaches the highest relation with physical activity, co-morbidity and health status.
A marked temperature dependence of the 13C and 15N chemical shifts of 3-hydroxypyridine in D2O (p... more A marked temperature dependence of the 13C and 15N chemical shifts of 3-hydroxypyridine in D2O (pD = 7.0) was observed. This dependence is explained in terms of thermally induced equilibrium shifts between the neutral form and the zwitterionic form of 3-hydroxypyridine. A method was developed to characterize the thermodynamics of the equilibria that are rapid on the NMR time scale, using the observed average 13C and 15N chemical shifts at different temperatures. This method was applied to the thermodynamics of the tautomerization equilibria of 3-hydroxypyridine. The equilibrium constants and the standard enthalpy change of the tautomerization equilibrium obtained by 13C and 15N methods agree very well with the results obtained by other spectroscopic methods.
A remarkable temperature dependence on the 13C NMR and 15N NMR chemical shifts of pyridoxine in w... more A remarkable temperature dependence on the 13C NMR and 15N NMR chemical shifts of pyridoxine in water (pH = 7.0) has been observed. C-3, C-6, and N-1 were the most sensitive nuclei to the temperature effect. This dependence has been explained on the basis of an equilibrium shift thermally induced between the neutral and the dipolar form of this molecule. The thermodynamic characterization of tautomeric equilibria that interconvert quickly on the NMR time scale can be carried out from the observed average 13C NMR and 15N NMR chemical shifts at different temperatures (5-90 degrees C). We have developed a new method for the estimation of the thermodynamic parameters of a given equilibrium by fitting the experimental data to a theoretical curve. This new method allows us to improve the fitting results on our previously proposed methodology. We show that there are linear correlations between the average chemical shifts obtained from different nuclei at the same temperature. This indicates that the parameters of the pure forms are related among them. We have carried out a simultaneous multiple function curve fitting of all data obtained from the most sensitive signals together using these linear correlations as restricted conditions in order to diminish the number of independent parameters to fit. To test the new methodology, we have studied the thermodynamics of the tautomeric equilibrium of pyridoxine in water. We have obtained delta H degree values ranging from -23.6 +/- 1.3 to -25.8 +/- 1.7 kJ/mol for this equilibrium depending on the used data set. This kind of methodology has, among others, the following advantages: It allows the use of a great number of experimental points from different signals in the fitting process, it yields very precise and accurate values of the tautomeric process, and it allows the resolution of the problem with only 13C NMR data in some cases saving NMR time.
COPD: Journal of Chronic Obstructive Pulmonary Disease, 2013
Our aim was to describe the population-based distribution of several COPD multi-dimensional indic... more Our aim was to describe the population-based distribution of several COPD multi-dimensional indices and to evaluate their relationship with daily physical activity, co-morbidity, health status and systemic inflammatory biomarkers. From a population-based sample of 3,802 subjects aged 40-80 from the EPI-SCAN study, 382 subjects (10.2%) with a post-bronchodilator FEV1/FVC<0.7 were identified as COPD. Smoking habits, respiratory symptoms, quality of life, co-morbidities, lung function and inflammatory biomarkers were recorded. Health status and daily physical activity were assessed using the EQ-5D and LCADL questionnaires, respectively. The new GOLD grading and the BODE, ADO, DOSE, modified DOSE, e-BODE, BODEx, CPI, SAFE and HRS indices were determined. A notable dispersion in the total scores was observed, although 83-88% of the COPD patients were classified into the mildest level and 1-3% in the most severe. The SAFE index was the best independent determinant of daily physical activity; the SAFE and ADO indices were associated with presence of co-morbidity; and the SAFE and modified DOSE indices were independently related to health status. The systemic biomarkers showed a less consistent relation with several indices. In a population-based sample of COPD patients, the SAFE index reaches the highest relation with physical activity, co-morbidity and health status.
A marked temperature dependence of the 13C and 15N chemical shifts of 3-hydroxypyridine in D2O (p... more A marked temperature dependence of the 13C and 15N chemical shifts of 3-hydroxypyridine in D2O (pD = 7.0) was observed. This dependence is explained in terms of thermally induced equilibrium shifts between the neutral form and the zwitterionic form of 3-hydroxypyridine. A method was developed to characterize the thermodynamics of the equilibria that are rapid on the NMR time scale, using the observed average 13C and 15N chemical shifts at different temperatures. This method was applied to the thermodynamics of the tautomerization equilibria of 3-hydroxypyridine. The equilibrium constants and the standard enthalpy change of the tautomerization equilibrium obtained by 13C and 15N methods agree very well with the results obtained by other spectroscopic methods.
A remarkable temperature dependence on the 13C NMR and 15N NMR chemical shifts of pyridoxine in w... more A remarkable temperature dependence on the 13C NMR and 15N NMR chemical shifts of pyridoxine in water (pH = 7.0) has been observed. C-3, C-6, and N-1 were the most sensitive nuclei to the temperature effect. This dependence has been explained on the basis of an equilibrium shift thermally induced between the neutral and the dipolar form of this molecule. The thermodynamic characterization of tautomeric equilibria that interconvert quickly on the NMR time scale can be carried out from the observed average 13C NMR and 15N NMR chemical shifts at different temperatures (5-90 degrees C). We have developed a new method for the estimation of the thermodynamic parameters of a given equilibrium by fitting the experimental data to a theoretical curve. This new method allows us to improve the fitting results on our previously proposed methodology. We show that there are linear correlations between the average chemical shifts obtained from different nuclei at the same temperature. This indicates that the parameters of the pure forms are related among them. We have carried out a simultaneous multiple function curve fitting of all data obtained from the most sensitive signals together using these linear correlations as restricted conditions in order to diminish the number of independent parameters to fit. To test the new methodology, we have studied the thermodynamics of the tautomeric equilibrium of pyridoxine in water. We have obtained delta H degree values ranging from -23.6 +/- 1.3 to -25.8 +/- 1.7 kJ/mol for this equilibrium depending on the used data set. This kind of methodology has, among others, the following advantages: It allows the use of a great number of experimental points from different signals in the fitting process, it yields very precise and accurate values of the tautomeric process, and it allows the resolution of the problem with only 13C NMR data in some cases saving NMR time.
Uploads
Papers by Luis Muñoz