Structural analysis of receptors and actin polarity in platelet protrusions.

During activation the platelet cytoskeleton is reorganized, inducing adhesion to the extracellular matrix and cell spreading. These processes are critical for wound healing and clot formation. Initially, this task relies on the formation of strong cellular-extracellular matrix interactions, exposed in subendothelial lesions. Despite the medical relevance of these processes, there is a lack of high-resolution structural information on the platelet cytoskeleton controlling cell spreading and adhesion. Here, we present in situ structural analysis of membrane receptors and the underlying cytoskeleton in platelet protrusions by applying cryoelectron tomography to intact platelets. We utilized three-dimensional averaging procedures to study receptors at the plasma membrane. Analysis of substrate interaction-free receptors yielded one main structural class resolved to 26 Å, resembling the αIIbß3 integrin folded conformation. Furthermore, structural analysis of the actin network in pseudopodia indicates a nonuniform polarity of filaments. This organization would allow generation of the contractile forces required for integrin-mediated cell adhesion.

Advances in Xmipp for Cryo-Electron Microscopy: From Xmipp to Scipion.

Xmipp is an open-source software package consisting of multiple programs for processing data originating from electron microscopy and electron tomography, designed and managed by the Biocomputing Unit of the Spanish National Center for Biotechnology, although with contributions from many other developers over the world. During its 25 years of existence, Xmipp underwent multiple changes and updates. While there were many publications related to new programs and functionality added to Xmipp, there is no single publication on the Xmipp as a package since 2013. In this article, we give an overview of the changes and new work since 2013, describe technologies and techniques used during the development, and take a peek at the future of the package.

Hospital admissions and exercise capacity decline in patients with COPD.

Exercise capacity declines with time and is an important determinant of health status and prognosis in patients with chronic obstructive pulmonary disease (COPD). We hypothesised that hospital admissions are associated with exercise capacity decline in these patients. Clinical and functional variables were collected for 342 clinically stable COPD patients. The 6-min walk distance (6MWD) was determined at baseline and after a mean±sd of 1.7±0.3 years. Information on hospitalisations during follow-up was obtained from centralised administrative databases. Linear regression was used to model changes in exercise capacity. Patients were mostly male (92%), with mean±sd age 67.9±8.6 years, post-bronchodilator forced expiratory volume in 1 s 54±17% predicted and baseline 6MWD 433±93 m. During follow-up, 6MWD decreased by 21.9±51.0 m·year(-1) and 153 (45%) patients were hospitalised at least once. Among patients admitted only for COPD-related causes (50% of those ever admitted), the proportion presenting a clinically significant loss of 6MWD was higher than in patients admitted for only nonrespiratory conditions (53% versus 29%, p=0.040). After adjusting for confounders, annual 6MWD decline was greater (26 m·year(-1), 95% CI 13-38 m·year(-1); p<0.001) in patients with more than one all-cause hospitalisation per year, as compared with those with no hospitalisations. Hospitalisations are related to a greater decline in exercise capacity in COPD.

Echocardiographic abnormalities in patients with COPD at their first hospital admission.

Cardiovascular disease accounts for significant morbidity and mortality in chronic obstructive pulmonary disease (COPD). Its prevalence and mechanisms of association have not been elucidated. The study aimed to assess the prevalence of echocardiographic abnormalities and potential risk factors in patients with COPD at their first exacerbation requiring hospital admission. Transthoracic echocardiography was prospectively performed in 342 patients (forced expiratory volume in 1 s 52 ± 16% predicted) 3 months after discharge. Significant cardiac alterations were present in 64% of patients; 27% left- and 48% right-heart disorders. The most common were right ventricle enlargement (30%) and pulmonary hypertension (19%). Left ventricle enlargement was present in 6%, left ventricle systolic dysfunction in 13%, left ventricle diastolic impairment in 12% and left atrial dilatation in 29%. Echocardiographic abnormalities were unrelated to COPD severity and were more frequent in patients with self-reported cardiac disease. They were also observed in 63% of patients with no known cardiac disease or cardiovascular risk factors other than smoking. We conclude that cardiac abnormalities are highly prevalent in COPD patients at the time of their first severe exacerbation, even in the absence of established cardiac disease or cardiovascular risk factors. Considering the prognostic and therapeutic implications of cardiac comorbidity, echocardiography should be considered in the assessment of patients with clinically significant COPD.

Salbutamol but not ipratropium abolishes leukotriene D4-induced gas exchange abnormalities in asthma.

PURPOSE: Leukotriene D(4) (LTD(4)) is a central mediator in asthma inducing bronchoconstriction and profound disturbances in pulmonary gas exchange in asthmatic subjects. The aim of the study was to compare, for the first time, the influence of the bronchodilators salbutamol (400 µg) and ipratropium (80 µg) on lung function changes induced by inhaled LTD(4). METHODS: Treatments were evaluated in a randomized, three-period, double-blind, placebo-controlled, cross-over study where spirometric and pulmonary gas exchange indices were followed in 12 subjects with mild asthma before and after LTD(4) challenge. RESULTS: Compared with placebo, salbutamol provided significant protection against the fall in FEV(1) (forced expiratory volume in 1 s) after LTD(4) challenge. Salbutamol also abolished the LTD(4)-induced gas exchange disturbances [decreased arterial oxygen tension (PaO(2)) and increased alveolar-arterial oxygen tension difference (AaPO(2))]. Ipratropium provided significant but less marked attenuation of the changes in FEV(1) and arterial oxygenation induced by LTD(4). CONCLUSION: Despite the equal bronchodilatory effects of salbutamol and ipratropium before the challenge with LTD(4), salbutamol was superior to ipratropium in preventing spirometric and gas exchange abnormalities. This result indicates a broader action of salbutamol on several of the disturbances that contribute to airway obstruction including, for example, exudation of plasma in the airway mucosa. The clinical implication of this new finding is that in this model of acute asthmatic airway obstruction, salbutamol was more effective than ipratropium.

Anti-tissue antibodies are related to lung function in chronic obstructive pulmonary disease.

RATIONALE: Chronic obstructive pulmonary disease (COPD) is a multicomponent disease. Autoimmunity can contribute to the pathogenesis of COPD. OBJECTIVES: This study investigates the prevalence of circulating antinuclear antibodies (ANA) and anti-tissue (AT) antibodies, two common markers of autoimmunity, in COPD and their relationship with several components of the disease. METHODS: We determined lung function, the serum titers of ANA and AT by immunofluorescence, and the serum levels of C-reactive protein (CRP) by high sensitivity nephelometry in 328 patients with clinically stable COPD and in 67 healthy controls recruited in the PAC-COPD study. Multiple linear and logistic regression analysis was used to analyze results. MEASUREMENTS AND MAIN RESULTS: The prevalence of abnormal ANA and AT titers was 34% and 26% in patients and 3% and 6% in controls, respectively. Levels of AT greater than or equal to 1:320 were seen in 21% of patients with COPD and were independently associated with the severity of airflow limitation and gas transfer impairment (P < 0.05). Neither ANA or AT titers was related to body mass index, current smoking status, use of inhaled steroids, the Charlson index, or serum C-reactive protein values. CONCLUSIONS: Between a quarter and a third of patients with clinically stable COPD present abnormal titers of circulating ANA and AT. The observed relationship between AT and lung function supports a role for autoimmunity in the pathogenesis of COPD.

Identification and prospective validation of clinically relevant chronic obstructive pulmonary disease (COPD) subtypes.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is increasingly considered a heterogeneous condition. It was hypothesised that COPD, as currently defined, includes different clinically relevant subtypes. METHODS: To identify and validate COPD subtypes, 342 subjects hospitalised for the first time because of a COPD exacerbation were recruited. Three months after discharge, when clinically stable, symptoms and quality of life, lung function, exercise capacity, nutritional status, biomarkers of systemic and bronchial inflammation, sputum microbiology, CT of the thorax and echocardiography were assessed. COPD groups were identified by partitioning cluster analysis and validated prospectively against cause-specific hospitalisations and all-cause mortality during a 4 year follow-up. RESULTS: Three COPD groups were identified: group 1 (n=126, 67 years) was characterised by severe airflow limitation (postbronchodilator forced expiratory volume in 1 s (FEV(1)) 38% predicted) and worse performance in most of the respiratory domains of the disease; group 2 (n=125, 69 years) showed milder airflow limitation (FEV(1) 63% predicted); and group 3 (n=91, 67 years) combined a similarly milder airflow limitation (FEV(1) 58% predicted) with a high proportion of obesity, cardiovascular disorders, diabetes and systemic inflammation. During follow-up, group 1 had more frequent hospitalisations due to COPD (HR 3.28, p<0.001) and higher all-cause mortality (HR 2.36, p=0.018) than the other two groups, whereas group 3 had more admissions due to cardiovascular disease (HR 2.87, p=0.014). CONCLUSIONS: In patients with COPD recruited at their first hospitalisation, three different COPD subtypes were identified and prospectively validated: 'severe respiratory COPD', 'moderate respiratory COPD', and 'systemic COPD'.

Health changes in fishermen 2 years after clean-up of the Prestige oil spill.

BACKGROUND: In 2002, the oil tanker Prestige spilled more than 67,000 tons of bunker oil, heavily contaminating the coast of northwestern Spain. OBJECTIVE: To assess respiratory effects and chromosomal damage in clean-up workers of the oil spill 2 years after the exposure. DESIGN: Cross-sectional study. SETTING: Fishermen cooperatives in coastal villages. PARTICIPANTS: Local fishermen who were highly exposed (n = 501) or not exposed (n = 177) to oil 2 years after the spill. MEASUREMENTS: Respiratory symptoms; forced spirometry; methacholine challenge; markers of oxidative stress (8-isoprostane), airway inflammation (interleukins, tumor necrosis factor-α, and interferon-γ), and growth factor activity in exhaled breath condensate; and chromosomal lesions and structural alterations in circulating lymphocytes. RESULTS: Compared with nonexposed participants, persons exposed to oil were at increased risk for lower respiratory tract symptoms (risk difference, 8.0 [95% CI, 1.1 to 14.8]). Lung function did not significantly differ between the groups. Among nonsmoking participants, exposed individuals had higher exhaled 8-isoprostane levels than nonexposed individuals (geometric mean ratio, 2.5 [CI, 1.7 to 3.7]), and exposed individuals with lower respiratory tract symptoms had higher 8-isoprostane levels than those of exposed individuals without symptoms. Exposed nonsmoking participants also had higher levels of exhaled vascular endothelial growth factor (risk difference, 44.8 [CI, 27.9 to 61.6]) and basic fibroblast growth factor (risk difference, 16.0 [CI, 3.5 to 28.6]). A higher proportion of exposed participants had structural chromosomal alterations (risk difference, 27.4 [CI, 10.0 to 44.8]), predominantly unbalanced alterations. The risk for elevated levels of exhaled 8-isoprostane, vascular endothelial growth factor, and basic fibroblast growth factor and structural chromosomal alterations seemed to increase with intensity of exposure to clean-up work. LIMITATIONS: The clinical significance of exhaled biomarkers and chromosomal findings are uncertain. The association between oil exposure and the observed changes may not be causal. The findings may not apply to spills involving other types of oil or to different populations of oil spill workers. CONCLUSION: Participation in clean-up of a major oil spill was associated with persistent respiratory symptoms, elevated markers of airway injury in breath condensate, and chromosomal damage.

Graphite to diamond transition induced by photoelectric absorption of ultraviolet photons.

The phase transition from graphite to diamond is an appealing object of study because of many fundamental and also, practical reasons. The out-of-plane distortions required for the transition are a good tool to understand the collective behaviour of layered materials (graphene, graphite) and the van der Waals forces. As today, two basic processes have been successfully tested to drive this transition: strong shocks and high energy femtolaser excitation. They induce it by increasing either pressure or temperature on graphite. In this work, we report a third method consisting in the irradiation of graphite with ultraviolet photons of energies above 4.4 eV. We show high resolution electron microscopy images of pyrolytic carbon evidencing the dislocation of the superficial graphitic layers after irradiation and the formation of crystallite islands within them. Electron energy loss spectroscopy of the islands show that the sp2 to sp3 hybridation transition is a surface effect. High sensitivity X-ray diffraction experiments and Raman spectroscopy confirm the formation of diamond within the islands.

Expansion of the prognostic assessment of patients with chronic obstructive pulmonary disease: the updated BODE index and the ADO index.

BACKGROUND: The BODE index (including body-mass index, airflow obstruction, dyspnoea, and exercise capacity) was an important contribution to the prognostic assessment of patients with chronic obstructive pulmonary disease (COPD). However, no study has assessed whether the risk of mortality predicted by the BODE index matches the observed mortality in different populations. We assessed the calibration of the BODE index, updated it to improve its calibration, and developed and validated a simplified index for use in primary-care settings. METHODS: We included 232 patients from the Swiss Barmelweid cohort with longstanding and severe COPD and 342 patients from the Spanish Phenotype and Course of COPD cohort study who had had their first hospital admission due to moderate-to-severe COPD. In both cohorts we compared the observed 3-year risk of all-cause mortality with the risk predicted by the BODE index. We then updated the BODE index and developed a simplified ADO index (including age, dyspnoea, and airflow obstruction) from the Swiss cohort, and validated both in the Spanish cohort. FINDINGS: Calibration of the BODE index was poor, with relative underprediction of 3-year risk of mortality by 36% in the Swiss cohort (median predicted risk 21.7% [IQR 12.7-31.7] vs 34.1% observed risk; p=0.013) and relative overprediction by 39% in the Spanish cohort (16.7% [12.7-31.7] vs 12.0%; p=0.035). The 3-year risk of mortality predicted by both the updated BODE (median 10.7% [8.1-13.8]) and ADO indices (11.8% [9.1-14.3]) matched the observed mortality in the Spanish cohort well (p=0.99 and p=0.98, respectively). INTERPRETATION: Both the updated BODE and ADO indices could lend support to the prognostic assessment of patients with COPD in specialised and primary-care settings. Such assessment enhances the targeting of treatments to individual patients. FUNDING: Swiss National Science Foundation; Klinik Barmelweid; Fondo de Investigación Sanitaria Ministry of Health, Spain; Agència d'Avaluació de Tecnologia i Recerca Mèdiques, Catalonia Government; Spanish Society of Pneumology and Thoracic Surgery; Catalan Foundation of Pneumology; Red RESPIRA; Red RCESP; Fondo de Investigación Sanitaria; Fondo de Investigación Sanitaria; Fundació La Marató de TV3; Novartis Farmacèutica, Spain.

[Phenotypic heterogeneity of chronic obstructive pulmonary disease]. / La heterogeneidad fenotípica de la EPOC.

A functional definition of chronic obstructive pulmonary disease (COPD) based on airflow limitation has largely dominated the field. However, a view has emerged that COPD involves a complex array of cellular, organic, functional, and clinical events, with a growing interest in disentangling the phenotypic heterogeneity of COPD. The present review is based on the opinion of the authors, who have extensive research experience in several aspects of COPD. The starting assumption of the review is that current knowledge on the pathophysiology and clinical features of COPD allows us to classify phenotypic information in terms of the following dimensions: respiratory symptoms and health status, acute exacerbations, lung function, structural changes, local and systemic inflammation, and systemic effects. Twenty-six phenotypic traits were identified and assigned to one of the 6 dimensions. For each dimension, a summary is provided of the best evidence on the relationships among phenotypic traits, in particular among those corresponding to different dimensions, and on the relationship between these traits and relevant events in the natural history of COPD. The information has been organized graphically into a phenotypic matrix where each cell representing a pair of phenotypic traits is linked to relevant references. The information provided has the potential to increase our understanding of the heterogeneity of COPD phenotypes and help us plan future studies on aspects that are as yet unexplored.

Pulmonary gas exchange response to exercise- and mannitol-induced bronchoconstriction in mild asthma.

Both exercise (EIB) and mannitol challenges were performed in asthmatic patients to assess and compare their pulmonary gas exchange responses for an equivalent degree of bronchoconstriction. In 11 subjects with EIB [27 +/- 4 (SD) yr; forced expiratory volume in 1 s (FEV(1)), 86 +/- 8% predicted], ventilation-perfusion (Va/Q) distributions (using multiple inert gas elimination technique) were measured 5, 15, and 45 min after cycling exercise (FEV(1) fall, 35 +/- 12%) and after mannitol (33 +/- 10%), 1 wk apart. Five minutes after EIB, minute ventilation (Ve; by 123 +/- 60%), cardiac output (Qt, by 48 +/- 29%), and oxygen uptake (Vo2; by 54 +/- 25%) increased, whereas arterial Po2 (Pa(O2); by 14 +/- 11 Torr) decreased due to moderate Va/Q imbalance, assessed by increases in dispersions of pulmonary blood flow (log SD(Q); by 0.53 +/- 0.16) and alveolar ventilation (log SD(V); by 0.28 +/- 0.15) (dimensionless) (P < 0.01 each). In contrast, for an equivalent degree of bronchoconstriction and minor increases in Ve, Qt, and Vo2, mannitol decreased Pa(O2) more intensely (by 24 +/- 9 Torr) despite fewer disturbances in log SDQ (by 0.27 +/- 0.12). Notwithstanding, mannitol-induced increase in log SDV at 5 min (by 0.35 +/- 0.15) was similar to that observed during EIB, as was the slow recovery in log SD(V) and high Va/Q ratio areas, at variance with the faster recovery of log SD(Q) and low Va/Q ratio areas. In asthmatic individuals, EIB provokes more Va/Q imbalance but less hypoxemia than mannitol, primarily due to postexercise increases in Ve and Qt benefiting Pa(O2). Va/Q inequalities during both challenges most likely reflect uneven airway narrowing and blood flow redistribution generating distinctive Va/Q patterns, including the development of areas with low and high Va/Q ratios.

Sustained low diffusing capacity in hepatopulmonary syndrome after liver transplantation.

AIM: To study the presence of sustained low diffusing capacity (DL(CO)) after liver transplantation (LT) in patients with hepatopulmonary syndrome (HPS). METHODS: Six patients with mild-to-severe HPS and 24 without HPS who underwent LT were prospectively followed before and after LT at mid-term (median, 15 mo). HPS patients were also assessed at long-tem (median, 86 mo). RESULTS: Before LT, HPS patients showed lower PaO(2) (71 +/- 8 mmHg), higher AaPO(2) (43 +/- 10 mmHg) and lower DL(CO) (54% +/- 9% predicted), due to a combination of moderate-to-severe ventilation-perfusion (V(A)/Q) imbalance, mild shunt and diffusion limitation, than non-HPS patients (94 +/- 4 mmHg and 19 +/- 3 mmHg, and 85% +/- 3% predicted, respectively) (P<0.05 each). Seven non-HPS patients had also reduced DL(CO) (70% +/- 4% predicted). At mid- and long-term after LT, compared to pre-LT, HPS patients normalized PaO(2) (91 +/- 3 mmHg and 87 +/- 5 mmHg), AaPO(2) (14 +/- 3 mmHg and 23 +/- 5 mmHg) and all V(A)/Q descriptors (P<0.05 each) without changes in DL(CO) (53% +/- 8% and 56% +/- 7% predicted, respectively). Post-LT DL(CO) in non-HPS patients with pre-LT low DL(CO) was unchanged (75% +/- 6% predicted). CONCLUSION: While complete V(A)/Q resolution in HPS indicates a reversible functional disturbance, sustained low DL(CO) after LT also present in some non-HPS patients, points to persistence of sub-clinical liver-induced pulmonary vascular changes.

Persistence of Breakage in Specific Chromosome Bands 6 Years after Acute Exposure to Oil.

BACKGROUND: The identification of breakpoints involved in chromosomal damage could help to detect genes involved in genetic disorders, most notably cancer. Until now, only one published study, carried out by our group, has identified chromosome bands affected by exposure to oil from an oil spill. In that study, which was performed two years after the initial oil exposure in individuals who had participated in clean-up tasks following the wreck of the Prestige, three chromosomal bands (2q21, 3q27, 5q31) were found to be especially prone to breakage. A recent follow-up study, performed on the same individuals, revealed that the genotoxic damage had persisted six years after oil exposure. OBJECTIVES: To determine whether there exist chromosome bands which are especially prone to breakages and to know if there is some correlation with those detected in the previous study. In addition, to investigate if the DNA repair problems detected previously persist in the present study. DESIGN: Follow-up study performed six years after the Prestige oil spill. SETTING: Fishermen cooperatives in coastal villages. PARTICIPANTS: Fishermen highly exposed to oil spill who participated in previous genotoxic study six years after the oil. MEASUREMENTS: Chromosome damage in peripheral lymphocytes. For accurate identification of the breakpoints involved in chromosome damage of circulating lymphocytes, a sequential stain/G-banding technique was employed. To determine the most break-prone chromosome bands, two statistical methods, the Fragile Site Multinomial and the chi-square tests (where the bands were corrected by their length) were used. To compare the chromosome lesions, structural chromosome alterations and gaps/breaks between two groups of individuals we used the GEE test which takes into account a possible within-individual correlation. Dysfunctions in DNA repair mechanisms, expressed as chromosome damage, were assessed in cultures with aphidicolin by the GEE test. RESULTS: Cytogenetic analyses were performed in 47 exposed individuals. A total of 251 breakpoints in exposed individuals) were identified, showing a non-uniform distribution in the human ideogram. Ten chromosome bands were found to be especially prone to breakage through both statistical methods. By comparing these bands with those observed in certain exposed individuals who had already participated the previous study, it was found in both studies that four bands (2q21, 3q27, 5q31 and 17p11.2) are particularly sensitive to breakage. Additionally, the dysfunction in DNA repair mechanisms was not significantly higher in oil-exposed individuals than in non-exposed individuals. LIMITATIONS: The sample size and the possibility of some kind of selection bias should be considered. Genotoxic results cannot be extrapolated to the high number of individuals who participated occasionally in clean-up tasks. CONCLUSION: Our findings show the existence of at least four target bands (2q21, 3q27, 5q31 and 17p11.2) with a greater propensity to break over time after an acute exposure to oil. The breaks in these bands, which are commonly involved in hematological cancer, may explain the increase of cancer risk reported in chronically benzene-exposed individuals. In addition, a more efficiency of the DNA repair mechanisms has been detected six years after in fishermen who were highly exposed to the oil spill. To date, only this study, performed by our group on the previous and present genotoxic effects, has analyzed the chromosomal regions affected by breakage after an acute oil exposure.

Follow-Up Genotoxic Study: Chromosome Damage Two and Six Years after Exposure to the Prestige Oil Spill.

BACKGROUND: The north-west coast of Spain was heavily contaminated by the Prestige oil spill, in 2002. Individuals who participated in the clean-up tasks showed increased chromosome damage two years after exposure. Long-term clinical implications of chromosome damage are still unknown. OBJECTIVE: To realize a follow-up genotoxic study to detect whether the chromosome damage persisted six years after exposure to the oil. DESIGN: Follow-up study. SETTING: Fishermen cooperatives in coastal villages. PARTICIPANTS: Local fishermen who were highly exposed (n = 52) and non-exposed (n = 23) to oil seven years after the spill. MEASUREMENTS: Chromosome damage in circulating lymphocytes. RESULTS: Chromosome damage in exposed individuals persists six years after oil exposure, with a similar incidence than those previously detected four years before. A surprising increase in chromosome damage in non-exposed individual was found six years after Prestige spill vs. those detected two years after the exposure. LIMITATIONS: The sample size and the possibility of some kind of selection bias should be considered. Genotoxic results cannot be extrapolated to the approximately 300,000 individuals who participated occasionally in clean-up tasks. CONCLUSION: The persistence of chromosome damage detected in exposed individuals six years after oil exposure seems to indicate that the cells of the bone marrow are affected. A surprising increase in chromosome damage in non-exposed individuals detected in the follow-up study suggests an indirect exposition of these individuals to some oil compounds or to other toxic agents during the last four years. More long-term studies are needed to confirm the presence of chromosome damage in exposed and non-exposed fishermen due to the association between increased chromosomal damage and increased risk of cancer. Understanding and detecting chromosome damage is important for detecting cancer in its early stages. The present work is the first follow-up cytogenetic study carried out in lymphocytes to determine genotoxic damage evolution between two and six years after oil exposure in same individuals.

Evaluation of the persistence of functional and biological respiratory health effects in clean-up workers 6 years after the prestige oil spill.

Fishermen who had participated in clean-up activities of the Prestige oil spill showed increased bronchial responsiveness and higher levels of respiratory biomarkers 2 years later. We aimed to evaluate the persistence of these functional and biological respiratory health effects 6 years after clean-up work. In 2008/2009 a follow-up study was done in 230 never-smoking fishermen who had been exposed to clean-up work in 2002/2003 and 87 non-exposed fishermen. Lung function and bronchial responsiveness testing and the determination of respiratory biomarkers in exhaled breath condensate were done identically as in the baseline survey in 2004/2005. Associations between participation in clean-up work and respiratory health parameters were assessed using linear and logistic regression analyses adjusting for sex and age. Information from 158 exposed (69%) and 57 non-exposed (66%) fishermen was obtained. Loss to follow-up in the non-exposed was characterised by less respiratory symptoms at baseline. During the 4-year follow-up period lung function, bronchial hyperresponsiveness and the levels of respiratory biomarkers of oxidative stress and growth factors had deteriorated notably more among non-exposed than among exposed. At follow-up, respiratory health indices were similar or better in clean-up workers than in non-exposed. No clear differences between highly exposed and moderately exposed clean-up workers were found. In conclusion, we could not detect long-term respiratory health effects in clean-up workers 6 years after the Prestige oil spill. Methodological issues that need to be considered in this type of studies include the choice of a non-exposed control group and limitation of follow-up to subgroups such as never smokers.

Determinants of exercise capacity in obese and non-obese COPD patients.

BACKGROUND: The effects of obesity in combination with chronic obstructive pulmonary disease (COPD) on exercise capacity are receiving increased attention. But, a comprehensive analysis of factors associated with aerobic capacity in obese COPD patients has not been performed. METHODS: Six-min walking test (6MWT) was performed in 251 COPD patients, and 159 of those also carried out an incremental cardiopulmonary exercise test (CPET) to evaluate exercise capacity. In all patients, anthropometrics, dyspnea and anxiety-depression scores, lung function, daily physical activity, co-morbidities and circulating inflammatory biomarkers were also assessed. Six-min walking distance (6MWD) and peak oxygen uptake (VO2 peak) during CPET were two primary outcome variables. RESULTS: 57% of the patients showed body mass index (BMI) < 30 kg/m2 (COPDN) and the remaining 43% were obese with a BMI ≥ 30 kg/m2 (COPDO). In patients with COPDN, 6MWD showed independent negative associations with age, dyspnea score, sedentarism, depression scores and a positive relationship with arterial oxygenation; whereas in COPDO, 6MWD showed an inverse relationship with BMI. In COPDN, VO2 peak showed a negative association with age and positive relationships with both FEV1 and DLCO. However, in COPDO the dyspnea score was the strongest determinant of VO2 peak. CONCLUSIONS: Obese and non-obese COPD patients show different determinants of aerobic capacity, including pulmonary and non-pulmonary factors that are also dependent on the type of exercise protocol. These results could be considered in the evaluation of obese patients with COPD.

Effect of nitric oxide inhalation on gas exchange in acute severe pneumonia.

Inhaled nitric oxide (NO) causes selective pulmonary vasodilatation and may improve gas exchange. The study was aimed to evaluate the acute effects of inhaled NO on pulmonary gas exchange in severe unilateral pneumonia, where hypoxemia results from increased intrapulmonary shunt. We studied 8 patients without preexisting lung disease (59±18 yr; 4M/4F) with early unilateral severe pneumonia and respiratory failure. Pulmonary and systemic hemodynamics and gas exchange, including ventilation-perfusion (V;A/Q;) distributions, were measured at baseline and while breathing 5 and 40 parts per million (ppm) of NO. Inhaled NO caused a dose-dependent fall in pulmonary vascular resistance (by 12% and 21%, with 5 and 40ppm, respectively; p<0.01, each) and improvement of PaO2 (by 25% and 23%; p<0.05, each), owing to the reduction of intrapulmonary shunt (by 23% and 27%; p<0.05, each), without changes in the amount of perfusion to low V;A/Q; ratio alveolar units. Patients with greater baseline intrapulmonary shunt exhibited greater improvement in arterial oxygenation (r(2)=0.55, p<0.05). We conclude that low doses of inhaled NO improve pulmonary gas exchange in acute severe pneumonia.

Pulmonary vascular abnormalities in chronic obstructive pulmonary disease undergoing lung transplant.

BACKGROUND: Little is known about the structure and function relationships of pulmonary vessels in the most severe chronic obstructive pulmonary disease (COPD) spectrum. We investigated morphometric, cellular, and physiologic characteristics of pulmonary arteries from COPD patients undergoing bilateral lung transplant. METHODS: Seventeen patients with very severe COPD (forced expiratory volume in 1 second, 24% ± 7%) were assessed using inert gas exchange and pulmonary hemodynamics while breathing ambient air and 100% oxygen. Morphometry, in vitro reactivity to hypoxia, and inflammatory cell counts of pulmonary arteries were measured in explanted lungs. RESULTS: Patients had moderate ventilation-perfusion imbalance along with mild release of hypoxic pulmonary vasoconstriction. Mild pulmonary hypertension was observed in 7 patients. Explanted lungs had predominant emphysema with mild small airway involvement. In vitro reactivity was modestly altered, with relatively preserved endothelium-dependent relaxation, and vascular remodelling was discrete, with intense CD8+ T lymphocytes infiltrate. In vitro reactivity correlated with pulmonary vascular resistance (on ambient air) and oxygen-induced pulmonary artery pressure changes. Patients with pulmonary hypertension had more severe morphologic and physiologic emphysema. CONCLUSIONS: In end-stage COPD patients undergoing lung transplant, pulmonary vascular involvement is unexpectedly modest, with low-grade endothelial dysfunction. In this sub-set of COPD patients, pulmonary emphysema may constitute the major determinant of the presence of pulmonary hypertension.

Chromosomal bands affected by acute oil exposure and DNA repair errors.

BACKGROUND: In a previous study, we showed that individuals who had participated in oil clean-up tasks after the wreckage of the Prestige presented an increase of structural chromosomal alterations two years after the acute exposure had occurred. Other studies have also reported the presence of DNA damage during acute oil exposure, but little is known about the long term persistence of chromosomal alterations, which can be considered as a marker of cancer risk. OBJECTIVES: We analyzed whether the breakpoints involved in chromosomal damage can help to assess the risk of cancer as well as to investigate their possible association with DNA repair efficiency. METHODS: Cytogenetic analyses were carried out on the same individuals of our previous study and DNA repair errors were assessed in cultures with aphidicolin. RESULTS: Three chromosomal bands, 2q21, 3q27 and 5q31, were most affected by acute oil exposure. The dysfunction in DNA repair mechanisms, expressed as chromosomal damage, was significantly higher in exposed-oil participants than in those not exposed (p= 0.016). CONCLUSION: The present study shows that breaks in 2q21, 3q27 and 5q31 chromosomal bands, which are commonly involved in hematological cancer, could be considered useful genotoxic oil biomarkers. Moreover, breakages in these bands could induce chromosomal instability, which can explain the increased risk of cancer (leukemia and lymphomas) reported in chronically benzene-exposed individuals. In addition, it has been determined that the individuals who participated in clean-up of the oil spill presented an alteration of their DNA repair mechanisms two years after exposure.