Nitric oxide (NO) is an endogenous vasoactive compound that contributes to pulmonary vascular homeostasis and is produced by three nitric oxide synthase (NOS) isoforms-neuronal NOS (nNOS); inducible NOS (iNOS); and endothelial NOS (eNOS)-all three of which are present in the lung. Studies using pharmacological inhibitors or knockout mice have shown that eNOS-derived NO plays an important role in modulating pulmonary vascular tone and attenuating pulmonary hypertension. However, studies focusing on the role of iNOS have shown that this isoform contributes to the pathophysiology of acute lung injury and acute respiratory distress syndrome. This review aimed at outlining the role played by NO in the control of pulmonary circulation, both under physiological and pathophysiological conditions. In addition, we review the evidence that the L-arginine-NO-cyclic guanosine monophosphate pathway is a major pharmacological target in the treatment of pulmonary vascular diseases.

Keywords: Nitric oxide; Arginine; Nitric oxide synthase; Cyclic GMP; Pulmonary circulation.

This paper reviews in brief the role of nitric oxide in the respiratory physiology and in the pathology of some pulmonary diseases. The potential diagnostic and monitoring uses in several clinical situations are also discussed.

Keywords: respiratory tract diseases; lung diseases, obstructive; asthma; smoking; cystic fibrosis; bronchiectasis lung; lung transplantation

Knowledge of the structure and function of pulmonary circulation has evolved considerably in the last few decades. The use of non-invasive imaging techniques to assess the anatomy and function of the pulmonary vessels and heart has taken on added importance with the recent advent of novel therapies. Imaging findings not only constitute a diagnostic tool but have also proven to be essential for prognosis and treatment follow-up. This article reviews the myriad of imaging methods currently available for the assessment of pulmonary circulation, from the simple chest X-ray to techniques that are more complex and promising, such as electrical impedance tomography.

Keywords: Pulmonary circulation; Diagnostic imaging; Hypertension, pulmonary.

Lung cancer is the leading cause of cancer-related deaths worldwide. Promising new therapies have recently emerged from the development of molecular targeted drugs; particularly promising are those blocking the signal transduction machinery of cancer cells. One of the most widely studied cell signaling pathways is that of EGFR, which leads to uncontrolled cell proliferation, increased cell angiogenesis, and greater cell invasiveness. Activating mutations in the EGFR gene (deletions in exon 19 and mutation L858R in exon 21), first described in 2004, have been detected in approximately 10% of all non-squamous non-small cell lung cancer (NSCLC) patients in Western countries and are the most important predictors of a response to EGFR tyrosine-kinase inhibitors (EGFR-TKIs). Studies of the EGFR-TKIs gefitinib, erlotinib, and afatinib, in comparison with platinum-based regimens, as first-line treatments in chemotherapy-naïve patients have shown that the EGFR-TKIs produce gains in progression-free survival and overall response rates, although only in patients whose tumors harbor activating mutations in the EGFR gene. Clinical trials have also shown EGFR-TKIs to be effective as second- and third-line therapies in advanced NSCLC. Here, we review the main aspects of EGFR pathway activation in NSCLC, underscore the importance of correctly identifying activating mutations in the EGFR gene, and discuss the main outcomes of EGFR-TKI treatment in NSCLC.

Keywords: Molecular targeted therapy; Receptor, epidermal growth factor; Lung neoplasms/drug therapy; Mutation; Oncogenes.

Multiple respiratory abnormalities can be found in anxiety disorders, especially in panic disorder (PD). Individuals with PD experience unexpected panic attacks, characterized by anxiety and fear, resulting in a number of autonomic and respiratory symptoms. Respiratory stimulation is a common event during panic attacks. The respiratory abnormality most often reported in PD patients is increased CO2 sensitivity, which has given rise to the hypothesis of fundamental abnormalities in the physiological mechanisms that control breathing in PD. There is evidence that PD patients with dominant respiratory symptoms are more sensitive to respiratory tests than are those who do not manifest such symptoms, and that the former group constitutes a distinct subtype. Patients with PD tend to hyperventilate and to panic in response to respiratory stimulants such as CO2, triggering the activation of a hypersensitive fear network. Although respiratory physiology seems to remain normal in these subjects, recent evidence supports the idea that they present subclinical abnormalities in respiration and in other functions related to body homeostasis. The fear network, composed of the hippocampus, the medial prefrontal cortex, the amygdala and its brain stem projections, might be oversensitive in PD patients. This theory might explain why medication and cognitive-behavioral therapy are both clearly effective. Our aim was to review the relationship between respiration and PD, addressing the respiratory subtype of PD and the hyperventilation syndrome, with a focus on respiratory challenge tests, as well as on the current mechanistic concepts and the pharmacological implications of this relationship.

Keywords: Panic disorder; Anxiety; Respiration; Hyperventilation; Carbon dioxide.

The aim of the study was to assess short-term repeatability of measurements of fractional exhaled nitric oxide (FENO) and its correlates in children in the 6- to 9-year age bracket participating in a respiratory epidemiological survey. FENO was measured in two sessions one week apart in 101 children. Participants were divided into three groups: asymptomatic (n = 76); symptomatic (n = 14); and asthma (n = 11). Absolute and relative differences between the measurements, as well as concordance correlation coefficients, were used in order to assess repeatability. The two FENO measurements were strongly correlated (0.98). Although intragroup comparisons of the two measurements were not significantly different (p = 0.2), intergroup comparisons were. FENO measurements are reproducible in children in epidemiological settings.

Keywords: Nitric oxide; Exhalation; Asthma.

Objective: To evaluate whether the acute pain experienced during in-hospital recovery from thoracotomy can be effectively reduced by the use of intraoperative measures (dissection of the neurovascular bundle prior to the positioning of the Finochietto retractor and preservation of the intercostal nerve during closure). Methods: We selected 40 patients who were candidates for elective thoracotomy in the Thoracic Surgery Department of the Federal University of São Paulo/Paulista School of Medicine, in the city of São Paulo, Brazil. The patients were randomized into two groups: conventional thoracotomy (CT, n = 20) and neurovascular bundle preservation (NBP, n = 20). All of the patients underwent thoracic epidural anesthesia and muscle-sparing thoracotomy. Pain intensity was assessed with a visual analog scale on postoperative days 1, 3, and 5, as well as by monitoring patient requests for/consumption of analgesics. Results: On postoperative day 5, the self-reported pain intensity was significantly lower in the NBP group than in the CT group (visual analog scale score, 1.50 vs. 3.29; p = 0.04). No significant differences were found between the groups regarding the number of requests for/consumption of analgesics. Conclusions: In patients undergoing thoracotomy, protecting the neurovascular bundle prior to positioning the retractor and preserving the intercostal nerve during closure can minimize pain during in-hospital recovery.

Keywords: Pain, postoperative; Analgesia; Thoracotomy.

Objective: To report the results obtained in three patients with diffuse pulmonary emphysema during the pre- and post-operative periods following a new surgical technique: collateral ventilation with lung parenchyma drainage. Methods: Patients suffering from pulmonary failure and disabling dyspnea, despite having received the gold standard treatment, including pulmonary rehabilitation, were selected for the evaluation of pulmonary drainage. During the pre- and post-operative periods, patients were submitted to plethysmography and six-minute walk tests, as well as completing the following quality of life questionnaires: Medical Outcomes Study 36-item Short-Form Health Survey, Saint George's Respiratory Questionnaire, Eastern Cooperative Oncology Group Performance Status and Medical Research Council Scale. In all three cases, the post-operative follow-up period was at least 300 days. The tests were performed at the following time points: during the pre-operative period; between post-operative days 30 and 40; and on post-operative day 300. Data were analyzed using profile plots of the means. Results: When the results obtained in the pre-operative period were compared to those obtained at the two post-operative time points evaluated, improvements were observed in all parameters studied. Conclusions: The results suggest that the surgical technique proposed for the treatment of patients suffering from severe diffuse emphysema successfully reduces the debilitating symptoms of these patients, improving their quality of life considerably.

Keywords: Pulmonary emphysema; Lung diseases, obstructive; Lung, hyperlucent.

In many populations, the prevalence of asthma and atopy has increased in recent years. As a result, both conditions have become major public health problems. The possible influence of nutrition-related factors has been demonstrated in an increasing number of studies. Information regarding the role of breastfeeding, diet, nutritional status (obesity in particular), as well as regarding the immunologic responses triggered, helps to improve our understanding of the correlation between oxidative stress, bronchial inflammation, and the development of atopic and asthma symptoms. The article presents a review of the published literature on the relationships established between and among nutrition, asthma, and atopy over the last two decades.

Keywords: Asthma; Nutritional status; Breast feeding; Diet.

The objective of this paper is to report some clinical and therapeutic aspects of inhaled nitric oxide in pediatrics. Some references were obtained from Medline® using the keywords: inhaled nitric oxide and pediatrics, and critical care. Other sources were the University library and personal files. Along the last decade, clinical trials with inhaled nitric oxide demonstrated only a few specific areas of proven efficacy and a variety of possible adverse events. Toxicity related to inhaled nitric oxide included metahemoglobinemia, cytotoxic pulmonary effects, excess production of nitrogen dioxide and peroxynitrite, and injury to the pulmonary surfactant system. The administration of inhaled nitric oxide to patients with severe left ventricular dysfunction and pulmonary hypertension should be cautious, since vasodilatation may increase pulmonary blood flow and lead to excessive preload. Some studies showed the clinical effects related to abrupt nitric oxide withdrawal, including rebound pulmonary hypertension. Current literature supports the therapeutic use of inhaled nitric oxide in persistent pulmonary hypertension of the newborn (gestational age ³ 34 weeks) to improve oxygenation and avoid extracorporeal oxygenation; and in congenital cardiopathy accompanied by pulmonary hypertension, especially in the immediate postoperative period. To date, research in pediatrics and multicentre trials in adults with inhaled nitric oxide therapy have failed to show mortality reduction or decrease the amount of time under mechanical ventilation for acute respiratory distress syndrome and acute lung injury. This indication needs further investigations. Persistent pulmonary hypertension is the most important indication for inhaled nitric oxide. The Food and Drug Administration has not approved inhaled nitric oxide in acute respiratory distress syndrome for adults and children.

Keywords: Nitric oxide/therapeutic use. Pediatrics. Pulmonary hypertension. Critical care.