Daniella Alves Vento

Exhaled nitrite/nitrate levels as a marker of respiratory complications after heart valve surgery.

PURPOSE The purposes of this study are to measure the nitric oxide metabolites nitrite and nitrate (NOx) in the exhaled breath condensates (EBCs) of patients submitted to heart valve surgery and to assess the correlation between NOx levels and postoperative respiratory complications. MATERIALS AND METHODS Exhaled breath condensate and blood samples were collected from each patient during spontaneous breathing preoperatively, during invasive mechanical ventilation in the fourth hour after surgery and 12, 24, 48, and 72 hours after the operation. Nitrite and nitrate levels in the EBC and serum were measured by chemiluminescence. RESULTS Thirty-two patients were included in the study. In patients who presented with postoperative respiratory complications, the postoperative levels of NOx were significantly higher in the EBC from the fourth postoperative hour compared with those who experienced uneventful postoperative periods (P = .027). However, the preoperative and postoperative serum levels of NOx were not significantly different in between-group analyses (P = .995). CONCLUSION Our results suggest that the postoperative NOx level in the EBC is an early marker of respiratory complications after heart valve surgery. Additional studies using large cohorts are necessary to corroborate our results and to better define the clinical usefulness of assessing NOx in the EBC after cardiac surgery.

Óxido nítrico en el condensado de aire espirado de individuos voluntarios sanos recolectado a través de un dispositivo reutilizable

BACKGROUND The analysis of exhaled breath condensate (EBC) is a non-invasive technique that enables the determination of several volatile and nonvolatile substances produced in the respiratory tract, whose measurement may be useful for the diagnosis and monitoring of several respiratory diseases. OBJECTIVE The aim of this study was to produce a low-cost reusable device in order to sample exhaled breath condensate in healthy adult volunteers, and to determine the concentration of nitric oxide in the sample collected. MATERIAL AND METHODS The apparatus was made with a U-shaped tube of borosilicate glass. The tube was placed in a container with ice, and unidirectional respiratory valves were fitted to the distal end. Afterwards, nitric oxide was measured in the exhaled breath condensate (EBC) by chemiluminescence. RESULTS The total cost of the device was

Effects of methylene blue in acute lung injury induced by oleic acid in rats.

120.20. EBC samples were obtained from 116 volunteers of both sexes, aged between 20 and 70. The mean volume of exhaled breath condensate collected during 10 minutes was 1.0 ± 0.6 mL, and the mean level of nitric oxide was 12.99 ± 14.38 μM (median 8.72 μM). There was no correlation between the nitric oxide levels in the exhaled breath condensate and age or gender. CONCLUSION We demonstrate that it is possible to fabricate a low-cost, efficient, reusable device in order to collect and determine nitric oxide levels in EBC. We have identified no correlation between the nitric oxide levels present in the EBC obtained with this method with either age or sex.

An adaptation for exhaled breath condensate collection in rabbits

BACKGROUND In acute lung injury (ALI), rupture of the alveolar-capillary barrier determines the protein-rich fluid influx into alveolar spaces. Previous studies have reported that methylene blue (MB) attenuates such injuries. This investigation was carried out to study the MB effects in pulmonary capillary permeability. METHODS Wistar rats were divided into five groups: (I) Sham: saline bolus; (II) MB, MB infusion for 2 h; (III) oleic acid (OA), OA bolus; (IV) MB/OA, MB infusion for 2 h, and at 5 min after from the beginning, concurrently with an OA bolus; and (V) OA/MB, OA bolus, and after 2 h, MB infusion for 2 h. After 4 h, blood, bronchoalveolar lavage (BAL), and lung tissue were collected from all groups for analysis of plasma and tissue nitric oxide, calculation of the wet weight to dry weight ratio (WW/DW), and histological examination of lung tissue. Statistical analysis was performed using nonparametric test. RESULTS Although favourable trends have been observed for permeability improvement parameters (WW/WD and protein), the results were not statistically significant. However, histological analysis of lung tissue showed reduced lesion areas in both pre- and post-treatment groups. CONCLUSIONS The data collected using this experimental model was favourable only through macroscopic and histological analysis. These observations are valid for both MB infusions before or after induction of ALI.

Nitric Oxide in the Exhaled Breath Condensate of Healthy Volunteers Collected With a Reusable Device

ABSTRACT Aim: To set up and test the feasibility of a handmade apparatus adapted for exhaled breath condensate (EBC) collection in medium-sized animals. Materials and Methods: The apparatus was produced using an 18-mm thick u-shaped borosilicate glass. The u-shaped tube body is 25 cm in diameter, and the horizontal portions are 12 cm in diameter. The base consists of a tube joint 14/20 or 14 mm thick by 20 cm in diameter, and has a length of 5 cm. This has a hole that is plugged for condensate flow to a 1.5 mL polypropylene microtube that stores the condensate during collection. Was placed inside a styrofoam box and immersed in crushed ice and salt to ensure cooling. The temperature was monitored and maintained throughout the collection at −10°C. One of the outputs of the u-shaped tube was connected to the expiratory limb of the ventilator. Results: An experimental model of ALI, induced by oleic acid (OA) was adopted to determine the concentration of biomarkers of oxidative stress: malondialdehyde (MDA), glutathione (GSH), and nitrite/nitrate (NOx). The proposed model allows measurement of NOx, MDA, and GSH. However, the NOx and MDA levels in the EBC were not significant. It was only possible to observe an upward trend, which suggests a temporal evolution of the presence of these markers in the EBC. Conclusion: The EBC collection method adapted is effective to generate sufficient content that allows to determine the levels of different biomarkers, such as NOx, MDA, and GSH, that are involved in oxidative and inflammatory stress processes during respiratory diseases.