Javier J. Zulueta

Regulation of bovine endothelial constitutive nitric oxide synthase by oxygen.

Oxygen (O2) may regulate pulmonary vascular resistance through changes in endothelial nitric oxide (NO) production. To determine whether constitutive NO synthase (cNOS) is regulated by O2, we assessed cNOS expression and activity in bovine pulmonary artery endothelial cells exposed to different concentrations of O2. In a time-dependent manner, changes in O2 concentration from 95 to 3% produced a progressive decrease in cNOS mRNA and protein levels resulting in 4.8- and 4.3-fold reductions after 24h, respectively. This correlated with changes in cNOS activity as determined by nitrite measurements. Compared with 20% O2, cNOS activity was increased 1.5-fold in 95% O2 and decreased 1.9-fold in 3% O2. A decrease in O2 concentration from 94 to 3% shortened cNOS mRNA half-life from 46 to 24 h and caused a 20-fold repression of cNOS gene transcription. Treatment with cycloheximide produced a threefold increase in cNOS mRNA at all O2 concentrations, suggesting that cNOS mRNA expression is negatively regulated under basal condition. We conclude that O2 upregulates cNOS expression through transcriptional and post-transcriptional mechanisms. A decrease in cNOS activity in the presence of low O2 levels, therefore, may contribute to hypoxia-induced vasoconstriction in the pulmonary circulation.

Lung cancer in patients with chronic obstructive pulmonary disease-- incidence and predicting factors.

RATIONALE Little is known about the clinical factors associated with the development of lung cancer in patients with chronic obstructive pulmonary disease (COPD), although airway obstruction and emphysema have been identified as possible risk factors. OBJECTIVES To explore incidence, histologic type, and factors associated with development of lung cancer diagnosis in a cohort of outpatients with COPD attending a pulmonary clinic. METHODS A cohort of 2,507 patients without initial clinical or radiologic evidence of lung cancer was followed a median of 60 months(30–90). At baseline, anthropometrics, smoking history, lung function,and body composition were recorded. Time to diagnosis and histologic type of lung cancer was then registered. Cox analysis was used to explore factors associated with lung cancer diagnosis. MEASUREMENTS AND MAIN RESULTS A total of 215 of the 2,507 patients with COPD developed lung cancer (incidence density of 16.7 cases per 1,000 person-years). The most frequent type was squamous cell carcinoma (44%). Lung cancer incidence was lower in patients with worse severity of airflow obstruction. Global Initiative for Chronic Obstructive Lung Disease Stages I and II, older age, lower body mass index,and lung diffusion capacity of carbon monoxide less than 80%were associated with lung cancer diagnosis. CONCLUSIONS Incidence density of lung cancer is high in outpatients with COPD and occurs more frequently in older patients with milder airflow obstruction (Global Initiative for Chronic Obstructive Lung Disease Stages I and II) and lower body mass index. A lung diffusion capacity of carbon monoxide less than 80% is associated with cancer diagnosis. Squamous cell carcinoma is the most frequent histologic type. Knowledge of these factors may help direct efforts for early detection of lung cancer and disease management.

Hyperleptinaemia, respiratory drive and hypercapnic response in obese patients

Leptin is a powerful stimulant of ventilation in rodents. In humans, resistance to leptin has been consistently associated with obesity. Raised leptin levels have been reported in subjects with sleep apnoea or obesity–hypoventilation syndrome. The aim of the present study was to assess, by multivariate analysis, the possible association between respiratory centre impairment and levels of serum leptin. In total, 364 obese subjects (body mass index ≥30 kg·m−2) underwent the following tests: sleep studies, respiratory function tests, baseline and hypercapnic response (mouth occlusion pressure (P0.1), minute ventilation), fasting leptin levels, body composition and anthropometric measures. Subjects with airways obstruction on spirometry were excluded. Out of the 346 subjects undergoing testing, 245 were included in the current analysis. Lung volumes, age, log leptin levels, end-tidal carbon dioxide tension, percentage body fat and minimal nocturnal saturation were predictors for baseline P0.1. The hypercapnic response test was performed by 186 subjects; log leptin levels were predictors for hypercapnic response in males, but not in females. Hyperleptinaemia is associated with a reduction in respiratory drive and hypercapnic response, irrespective of the amount of body fat. These data suggest the extension of leptin resistance to the respiratory centre.

Diagnostic Yield of Electromagnetic Navigation Bronchoscopy Is Highly Dependent on the Presence of a Bronchus Sign on CT Imaging: Results From a Prospective Study

BACKGROUND Electromagnetic navigation bronchoscopy (ENB) has been developed as a novel ancillary tool for the bronchoscopic diagnosis of pulmonary nodules. Despite successful navigation in 90% of patients, ENB diagnostic yield does not generally exceed 70%. We sought to determine whether the presence of a bronchus sign on CT imaging conditions diagnostic yield of ENB and might account for the discrepancy between successful navigation and diagnostic yield. METHODS We conducted a prospective, single-center study of ENB in 51 consecutive patients with pulmonary nodules. ENB was chosen as the least invasive diagnostic technique in patients with a high surgical risk, suspected metastatic disease, or advanced-stage disease, or in those who demanded a preoperative diagnosis prior to undergoing curative resection. We studied patient and technical variables that might condition diagnostic yield, including size, cause, location, distance to the pleural surface, and fluorodeoxyglucose uptake of a given nodule; the presence of a bronchus sign on CT imaging; registration point divergence; and the minimum distance from the tip of the locatable guide to the nodule measured during the procedure. RESULTS The diagnostic yield of ENB was 67% (34/51). The sensitivity and specificity of ENB for malignancy in this study were 71% and 100%, respectively. ENB was diagnostic in 79% (30/38) patients with a bronchus sign on CT imaging but only in 4/13 (31%) with no discernible bronchus sign. Univariate analysis identified the bronchus sign (P = .005) and nodule size (P = .04) as statistically significant variables conditioning yield, but on multivariate analysis, only the bronchus sign remained significant (OR, 7.6; 95% CI, 1.8-31.7). No procedure-related complications were observed. CONCLUSIONS ENB diagnostic yield is highly dependent on the presence of a bronchus sign on CT imaging.

Multicentre European study for the treatment of advanced emphysema with bronchial valves

This multicentre, blinded, sham-controlled study was performed to assess the safety and effectiveness of bronchial valve therapy using a bilateral upper lobe treatment approach without the goal of lobar atelectasis. Patients with upper lobe predominant severe emphysema were randomised to bronchoscopy with (n=37) or without (n=36) IBV Valves for a 3-month blinded phase. A positive responder was defined as having both a ≥4-point improvement in St George’s Respiratory Questionnaire (SGRQ) and a lobar volume shift as measured by quantitative computed tomography. At 3 months, there were eight (24%) positive responders in the treated group versus none (0%) in the control group (p=0.002). Also, there was a significant shift in volume in the treated group from the upper lobes (mean±sd -7.3±9.0%) to the non-treated lobes (6.7±14.5%), with minimal change in the control group (p<0.05). Mean SGRQ total score improved in both groups (treatment: -4.3±16.2; control: -3.6±10.7). The procedure and devices were well tolerated and there were no differences in adverse events reported in the treatment and control groups. Treatment with bronchial valves without complete lobar occlusion in both upper lobes was safe, but not effective in the majority of patients.

Original ResearchInterventional PulmonologyDiagnostic Yield of Electromagnetic Navigation Bronchoscopy Is Highly Dependent on the Presence of a Bronchus Sign on CT Imaging: Results From a Prospective Study

BACKGROUND Electromagnetic navigation bronchoscopy (ENB) has been developed as a novel ancillary tool for the bronchoscopic diagnosis of pulmonary nodules. Despite successful navigation in 90% of patients, ENB diagnostic yield does not generally exceed 70%. We sought to determine whether the presence of a bronchus sign on CT imaging conditions diagnostic yield of ENB and might account for the discrepancy between successful navigation and diagnostic yield. METHODS We conducted a prospective, single-center study of ENB in 51 consecutive patients with pulmonary nodules. ENB was chosen as the least invasive diagnostic technique in patients with a high surgical risk, suspected metastatic disease, or advanced-stage disease, or in those who demanded a preoperative diagnosis prior to undergoing curative resection. We studied patient and technical variables that might condition diagnostic yield, including size, cause, location, distance to the pleural surface, and fluorodeoxyglucose uptake of a given nodule; the presence of a bronchus sign on CT imaging; registration point divergence; and the minimum distance from the tip of the locatable guide to the nodule measured during the procedure. RESULTS The diagnostic yield of ENB was 67% (34/51). The sensitivity and specificity of ENB for malignancy in this study were 71% and 100%, respectively. ENB was diagnostic in 79% (30/38) patients with a bronchus sign on CT imaging but only in 4/13 (31%) with no discernible bronchus sign. Univariate analysis identified the bronchus sign (P = .005) and nodule size (P = .04) as statistically significant variables conditioning yield, but on multivariate analysis, only the bronchus sign remained significant (OR, 7.6; 95% CI, 1.8-31.7). No procedure-related complications were observed. CONCLUSIONS ENB diagnostic yield is highly dependent on the presence of a bronchus sign on CT imaging.

Emphysema Scores Predict Death From COPD and Lung Cancer

OBJECTIVE Our objective was to assess the usefulness of emphysema scores in predicting death from COPD and lung cancer. METHODS Emphysema was assessed with low-dose CT scans performed on 9,047 men and women for whom age and smoking history were documented. Each scan was scored according to the presence of emphysema as follows: none, mild, moderate, or marked. Follow-up time was calculated from time of CT scan to time of death or December 31, 2007, whichever came first. Cox regression analysis was used to calculate the hazard ratio (HR) of emphysema as a predictor of death. RESULTS Median age was 65 years, 4,433 (49%) were men, and 4,133 (46%) were currently smoking or had quit within 5 years. Emphysema was identified in 2,637 (29%) and was a significant predictor of death from COPD (HR, 9.3; 95% CI, 4.3-20.2; P < .0001) and from lung cancer (HR, 1.7; 95% CI, 1.1-2.5; P = .013), even when adjusted for age and smoking history. CONCLUSIONS Visual assessment of emphysema on CT scan is a significant predictor of death from COPD and lung cancer.

Lung Cancer in Patients with Chronic Obstructive Pulmonary Disease. Development and Validation of the COPD Lung Cancer Screening Score

RATIONALE Patients with chronic obstructive pulmonary disease (COPD) are at high risk for lung cancer (LC) and represent a potential target to improve the diagnostic yield of screening programs. OBJECTIVES To develop a predictive score for LC risk for patients with COPD. METHODS The Pamplona International Early Lung Cancer Detection Program (P-IELCAP) and the Pittsburgh Lung Screening Study (PLuSS) databases were analyzed. Only patients with COPD on spirometry were included. By logistic regression we determined which factors were independently associated with LC in PLuSS and developed a COPD LC screening score (COPD-LUCSS) to be validated in P-IELCAP. MEASUREMENTS AND MAIN RESULTS By regression analysis, age greater than 60, body mass index less than 25 kg/m(2), pack-years history greater than 60, and emphysema presence were independently associated with LC diagnosis and integrated into the COPD-LUCSS, which ranges from 0 to 10 points. Two COPD-LUCSS risk categories were proposed: low risk (scores 0-6) and high risk (scores 7-10). In comparison with low-risk patients, in both cohorts LC risk increased 3.5-fold in the high-risk category. CONCLUSIONS The COPD-LUCSS is a good predictor of LC risk in patients with COPD participating in LC screening programs. Validation in two different populations adds strength to the findings.

Assessment of Epidermal Growth Factor Receptor and K-Ras Mutation Status in Cytological Stained Smears of Non-Small Cell Lung Cancer Patients: Correlation with Clinical Outcomes

OBJECTIVE Epidermal growth factor receptor (EGFR) and K-ras mutations guide treatment selection in non-small cell lung cancer (NSCLC) patients. Although mutation status is routinely assessed in biopsies, cytological specimens are frequently the only samples available. We determined EGFR and K-ras mutations in cytological samples. METHODS DNA was extracted from 150 consecutive samples, including 120 Papanicolau smears (80%), 10 cell blocks (7%), nine fresh samples (6%), six ThinPrep® tests (4%), and five body cavity fluids (3.3%). Papanicolau smears were analyzed when they had >50% malignant cells. Polymerase chain reaction and direct sequencing of exons 18-21 of EGFR and exon 2 of K-ras were performed. EGFR mutations were simultaneously determined in biopsies and cytological samples from 20 patients. Activity of EGFR tyrosine kinase inhibitors (TKIs) was assessed. RESULTS The cytological diagnosis was adenocarcinoma in 110 samples (73%) and nonadenocarcinoma in 40 (27%) samples. EGFR mutations were identified in 26 samples (17%) and K-ras mutations were identified in 18 (12%) samples. EGFR and K-ras mutations were mutually exclusive. In EGFR-mutated cases, DNA was obtained from stained smears in 24 cases (92%), pleural fluid in one case (4%), and cell block in one case (4%). The response rate to EGFR TKIs in patients harboring mutations was 75%. The mutation status was identical in patients who had both biopsies and cytological samples analyzed. CONCLUSION Assessment of EGFR and K-ras mutations in cytological samples is feasible and comparable with biopsy results, making individualized treatment selection possible for NSCLC patients from whom tumor biopsies are not available.

Prognostic evaluation of COPD patients: GOLD 2011 versus BODE and the COPD comorbidity index COTE

Background The Global Obstructive Lung Disease (GOLD) 2011 revision recommends the multidimensional assessment of COPD including comorbidities and has developed a disease categories system (ABCD) attempting to implement this strategy. The added value provided by quantifying comorbidities and integrating them to multidimensional indices has not been explored. Objective Compare the prognostic value of the GOLD ABCD categories versus the BMI, Obstruction, Dyspnea, Exercise (BODE) index, and explore the added prognostic value of comorbidities evaluation to this multidimensional assessment. Methods From the patients who have been enrolled in the BODE study, we selected the most recent ones who had the available information needed to classify them by the ABCD GOLD categories. Cox proportional hazards ratios for all-cause mortality were performed for GOLD categories and BODE index. The added value of the comorbidity Copd cO-morbidity TEst (COTE) index was also explored using receiver operating curves (ROC) values. Results 707 patients were followed for 50±30 months including all degrees of airway limitation and BODE index severity. ABCD GOLD predicted global mortality (HR: 1.47; 95% CI 1.28 to 1.70) as did the BODE index (HR: 2.02; 95% CI 1.76 to 2.31). Area under the curve (AUC) of ROC for ABCD GOLD was 0.68; (95% CI 0.64 to 0.73) while for the BODE index was 0.71 (95% CI 0.67 to 0.76). The C statistics value was significantly higher for the observed difference. Adding the COTE index to the BODE index improved its AUC to 0.81 (95% CI 0.77 to 0.85), (χ2=40.28, p<0.001). Conclusions In this population of COPD patients, the BODE index had a better survival prediction than the ABCD GOLD categories. Adding the COTE to the BODE index was complimentary and significantly improved outcome prediction.