Browsing by Author "Diaz, Orlando"

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    C-Reactive protein levels in patients with chronic obstructive pulmonary disease
    (SOC MEDICA SANTIAGO, 2012) Diaz, Orlando; Parada, Alejandra; Ramos, Cristobal; Klaassen, Julieta; Carlos Diaz, Juan; Andresen, Max; Lisboa, Carmen; Saldias, Fernando
    Background: Patients with chronic obstructive pulmonary disease (COPD) have elevated serum levels of ultrasensitive C reactive protein (CRPus). This raise may be related directly to COPD and its associated systemic inflammation or secondary to other factors such as smoking status, disease severity, acute exacerbations, or associated complications. Aim: To evaluate the potential causes of raised levels of CRPus in stable COPD patients. Patients and Methods: Cohorts of 133 mild-to-very severe COPD patients (41 current smokers), 31 never-smokers, and 33 current smoker controls were compared. Clinical assessments included body mass index (BMA fat (FM) and fat-free mass (FFM) measurement by DEXA, forced expiratory volume in one second (FEV1), arterial oxygen tension (PaO2), six-minute walking test (SMWT), emphysema (EMPH) and right thigh muscle cross-sectional area (TMCSA), both quantified by high resolution computed tomography. Results: Serum CRPus levels were significantly higher in COPD patients than in controls (7 +/- 4.2 and 3.7 +/- 2.7 mg/L, respectively; p < 0.0001). Being smoker did not influence CRPus levels. These levels were significantly correlated with FM (r = 0.30), BMI (r = 0.21), FEV1 (r = -0.21), number of acute exacerbations of the disease in the last year (r = 0.28), and PaO2 (r = -0.27). Using multivariate analysis FM, PaO2, and number of acute exacerbations of the disease in the last year had the strongest association with CRPus levels. Conclusions: CRPus is elevated in COPD patients, independent of smoking status. It is weakly associated with fat mass, arterial oxygen tension and frequency of exacerbations. (Rev Med Chile 2012; 140: 569-578).
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    Morphometric analysis of airways in pre-COPD and mild COPD lungs using continuous surface representations of the bronchial lumen
    (2023) Ortiz-Puerta, David; Diaz, Orlando; Retamal, Jaime; Hurtado, Daniel E.
    Introduction: Chronic Obstructive Pulmonary Disease (COPD) is a prevalent respiratory disease that presents a high rate of underdiagnosis during onset and early stages. Studies have shown that in mild COPD patients, remodeling of the small airways occurs concurrently with morphological changes in the proximal airways. Despite this evidence, the geometrical study of the airway tree from computed tomography (CT) lung images remains underexplored due to poor representations and limited tools to characterize the airway structure.Methods: We perform a comprehensive morphometric study of the proximal airways based on geometrical measures associated with the different airway generations. To this end, we leverage the geometric flexibility of the Snakes IsoGeometric Analysis method to accurately represent and characterize the airway luminal surface and volume informed by CT images of the respiratory tree. Based on this framework, we study the airway geometry of smoking pre-COPD and mild COPD individuals.Results: Our results show a significant difference between groups in airway volume, length, luminal eccentricity, minimum radius, and surface-area-to-volume ratio in the most distal airways.Discussion: Our findings suggest a higher degree of airway narrowing and collapse in COPD patients when compared to pre-COPD patients. We envision that our work has the potential to deliver a comprehensive tool for assessing morphological changes in airway geometry that take place in the early stages of COPD.
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    Natriuretic peptide type-B can be a marker of reperfusion in patients with pulmonary thromboembolism subjected to invasive treatment
    (2012) Andresen, Max; Gonzalez, Alejandro; Mercado, Marcelo; Diaz, Orlando; Meneses, Luis; Fava, Mario; Cordova, Samuel; Castro, Ricardo
    This study was intended to investigate changes in cardiac biomarkers and pulmonary hemodynamic effects of invasive treatment in patients with intermediate-risk (hemodynamic stability with evidence of right ventricle dysfunction and/or myocardial injury) pulmonary embolism. Also, to also evaluate if natriuretic peptide type-B (NT-proBNP) plasma levels are associated with right ventricle function and pulmonary arterial pressures. Interventional study: Fourteen normotensive adult patients with acute and radiologically massive pulmonary embolism plus positive biomarkers and evidences of right ventricle dysfunction underwent invasive pulmonary angiography for invasive treatment consisting on mechanical thrombus fragmentation and catheter-directed intrathrombus thrombolysis. Angiography was repeated after 12-24 h to reevaluate perfusion status. Plasma biomarkers were monitored before and 8-h after intervention. Biomarkers were initially elevated in all patients. Eleven patients (78.6%) exhibited significant angiographic reperfusion. NT-proBNP and mean pulmonary arterial pressure decreased significantly in all of them [3693 (1803, 8862) to 1951 (1309, 7918) pg/ml; P = 0.008) and 40.0 (24.0, 46.0) to 22.0 (14.0, 27.0) mmHg; P = 0.003, respectively]. No significant variation was observed in troponin-T levels. In patients with high-risk pulmonary embolism, NT-proBNP plasma levels experience rapid and significant reduction after successful invasive treatment. In pulmonary embolism, serial measurements of NT-proBNP could be useful as a tracking tool to assess the success or failure of the thrombolytic treatment.
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    Prognostic assessment in COPD: Health related quality of life and the BODE index
    (W B SAUNDERS CO LTD, 2011) Marin, Jose M.; Cote, Claudia G.; Diaz, Orlando; Lisboa, Carmen; Casanova, Ciro; Lopez, Maria V.; Carrizo, Santiago J.; Pinto Plata, Victor; Dordelly, Luis J.; Nekach, Hafida; Celli, Bartolome R.
    Rationale: COPD is a debilitating disease with increasing mortality worldwide. The BODE index evaluates disease severity and the St George's Respiratory Questionnaire (SGRQ) measures health status.
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    Six-Minute Walking Distance in Women with COPD
    (TAYLOR & FRANCIS INC, 2011) de Torres, Juan P.; Casanova, Ciro; Cote, Claudia G.; Lopez, Maria V.; Diaz, Orlando; Maria Marin, Jose; Pinto Plata, Victor; Montes de Oca, Maria; Aguirre Jaime, Armando; Celli, Bartolome R.
    Background: The 6-minute walk distance (6MWD) has been useful in the evaluation of men with COPD. Little is known about 6MWD in women with the disease. Objectives: Using healthy women as a reference, to evaluate the factors that help determine 6MWD in women with COPD. To explore if the 350 meters threshold differentiates survival in women as it does in men. Methods: Healthy women (n = 164) and with COPD (n = 223) were included in the study. Age, pack-years history, smoking status, comorbidities (Charlson Index), BMI, MRC dyspnea, spirometry and 6MWD were recorded in all participants and PaO2 and IC/TLC in COPD women. The patients were prospectively followed and deaths registered. Factors predicting 6MWD were determined by multiple regression analysis. ROC analysis was used to calculate the best threshold value for the 6MWD with mortality as gold standard. Kaplan-Meier curves compared survival of patients that walked more or less than 350 m by age categories. Results: The 6MWD is decreased in women with COPD. Values decrease with age and GOLD stages. Age, BMI, smoking status, comorbidities, MRC and FEV1% are statistical significant predictors of 6MWD. A 350 m cut-off value has a good sensitivity and specificity to predict (73% and 80% respectively) and differentiate survival (p < 0.001 for log rank comparisons) in these patients. Conclusions: In women with COPD, the 6MWD decreases with age and GOLD stages. A 350 m distance is a valid threshold to differentiate survival. Further studies in different settings should confirm our findings.