Nitric oxide and the common cold

Supplementation of L-glutamine enhanced mucosal immunity and improved hormonal status of combat-sport athletes

BACKGROUND

Maintaining proper immune function and hormone status is important for athletes to avoid upper respiratory tract infection (URTI) and insufficient recovery, which is detrimental to sport performance and health. The aim of this study was to evaluate whether three-week supplementation of L-glutamine could benefit the mucosal immunity and hormonal status of combat-sport athletes as well as their rates of upper respiratory tract infection (URTI) and subjective feelings of well-being after intensive training.

METHODS

Twenty-one combat-sport athletes from the National Taiwan University of Sport were recruited in this study. After intensive training, two groups of the participants were asked to consume powder form of 0.3 g/kg body weight of L-glutamine (GLU group) or maltodextrin (PLA group) with drinking water in a randomized design at the same time every day during 3 weeks. Saliva samples were collected to measure immunoglobulin A (IgA), nitric oxide (NO), testosterone (T) and cortisol (C) before and after three-week supplementation; moreover, Hooper's index questionnaires were completed for wellness assessment. The incidence and duration of URTI were recorded by using a health checklist throughout the entire study period.

RESULTS

Supplementation of L-glutamine significantly enhanced the concentrations of IgA and NO in saliva; additionally, the incidence of URTI was significantly reduced. Regarding hormones, T concentration was significantly decreased in the PLA group, whereas C concentration was significantly increased, resulting in a significant decrease of T/C ratio. In contrast, the GLU group showed a significant increase of T/C ratio, while the mood scores of the Hooper's index questionnaire were higher in the PLA group.

CONCLUSIONS

Three-week supplementation of L-glutamine after intensive training enhanced the mucosal immunity, improved hormonal status and reduced the rate of URTI of combat-sport athletes while feelings of well-being were also enhanced. Therefore, L-glutamine would be beneficial for the sports performance and recovery of athletes.

Multiwavelength Photoacoustic Breath Analysis Sensor for the Diagnosis of Lung Diseases: COPD and Asthma

Breath analysis is emerging as a universal diagnostic method for clinical applications. The possibility of breath analysis is being explored vigorously using different analytical techniques. We have designed and assembled a multiwavelength UV photoacoustic spectroscopy (PAS) sensor for the said application. To optimize laser wavelength for sample excitation, photoacoustic signals from disease and normal conditions are recorded with different laser excitations (213, 266, 355, and 532 nm) on exhaled breath samples. Principal component analysis (PCA) of the PA signals has shown that 213, 266, and 355 nm laser excitations are suitable for breath analysis, with reliable descriptive statistics obtained for 266 nm laser. The study has, therefore, been extended for breath samples collected from asthma, chronic obstructive pulmonary disease (COPD), and normal subjects, using 266 nm laser excitation. PCA of the PA data shows good classification among asthma, COPD, and normal subjects. Match/No-match study performed with asthma, COPD, and normal calibration set has demonstrated the potential of using this method for diagnostic application. Sensitivity and specificity are observed as 88 and 89%, respectively. The area under the curve of the ROC curve is found to be 0.948, which justifies the diagnostic capability of the device for lung diseases. The same samples were studied using a commercial E-Nose, and the measurement outcome strongly supports the PAS results.

Inhaled Nitric Oxide in Acute Respiratory Distress Syndrome Subsets: Rationale and Clinical Applications

Acute respiratory distress syndrome (ARDS) is a life-threatening condition, characterized by diffuse inflammatory lung injury. Since the coronavirus disease 2019 (COVID-19) pandemic spread worldwide, the most common cause of ARDS has been the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Both the COVID-19-associated ARDS and the ARDS related to other causes-also defined as classical ARDS-are burdened by high mortality and morbidity. For these reasons, effective therapeutic interventions are urgently needed. Among them, inhaled nitric oxide (iNO) has been studied in patients with ARDS since 1993 and it is currently under investigation. In this review, we aim at describing the biological and pharmacological rationale of iNO treatment in ARDS by elucidating similarities and differences between classical and COVID-19 ARDS. Thereafter, we present the available evidence on the use of iNO in clinical practice in both types of respiratory failure. Overall, iNO seems a promising agent as it could improve the ventilation/perfusion mismatch, gas exchange impairment, and right ventricular failure, which are reported in ARDS. In addition, iNO may act as a viricidal agent and prevent lung hyperinflammation and thrombosis of the pulmonary vasculature in the specific setting of COVID-19 ARDS. However, the current evidence on the effects of iNO on outcomes is limited and clinical studies are yet to demonstrate any survival benefit by administering iNO in ARDS.

SNAP@CQD as a promising therapeutic vehicle against HCoVs: an overview

This report discusses potential therapies for treating human coronaviruses (HCoVs) and their economic impact. Specifically, we explore therapeutics that can support the body's immune response, including immunoglobulin (Ig)A, IgG and T-cell responses, to inhibit the viral replication cycle and improve respiratory function. We hypothesize that carbon quantum dots conjugated with S-nitroso-N-acetylpenicillamine (SNAP) could be a synergistic alternative cure for treating respiratory injuries caused by HCoV infections. To achieve this, we propose developing aerosol sprays containing SNAP moieties that release nitric oxide and are conjugated onto promising nanostructured materials. These sprays could combat HCoVs by inhibiting viral replication and improving respiratory function. Furthermore, they could potentially provide other benefits, such as providing novel possibilities for nasal vaccines in the future. Teaser: Synergistic effect of carbon quantum dots and S-nitroso-N-acetylpenicillamine (SNAP) could be suggested as an alternative treatment for the respiratory damage caused by HCoV infections that further open possibilities of developing novel nasal vaccines.

Respiratory psychophysiology and COVID-19: A research agenda

After multiple waves of the COVID-19 pandemic, it has become clear that the impact of SARS-CoV-2 will carry on for years to come. Acutely infected patients show a broad range of disease severity, depending on virus variant, vaccination status, age and the presence of underlying medical and physical conditions, including obesity. Additionally, a large number of patients who have been infected with the virus present with post-COVID syndrome. In September 2020, the International Society for the Advancement of Respiratory Psychophysiology organized a virtual interest meeting on 'Respiratory research in the age of COVID-19', which aimed to discuss how research in respiratory psychophysiology could contribute to a better understanding of psychophysiological interactions in COVID-19. In the resulting current paper, we propose an interdisciplinary research agenda discussing selected research questions on acute and long-term neurobiological, physiological and psychological outcomes and mechanisms related to respiration and the airways in COVID-19, as well as research questions on comorbidity and potential treatment options, such as physical rehabilitation.

Oxidative Stress-Related Mechanisms in SARS-CoV-2 Infections

The COVID-19 pandemic caused relatively high mortality in patients, especially in those with concomitant diseases (i.e., diabetes, hypertension, and chronic obstructive pulmonary disease (COPD)). In most of aforementioned comorbidities, the oxidative stress appears to be an important player in their pathogenesis. The direct cause of death in critically ill patients with COVID-19 is still far from being elucidated. Although some preliminary data suggests that the lung vasculature injury and the loss of the functioning part of pulmonary alveolar population are crucial, the precise mechanism is still unclear. On the other hand, at least two classes of medications used with some clinical benefits in COVID-19 treatment seem to have a major influence on ROS (reactive oxygen species) and RNS (reactive nitrogen species) production. However, oxidative stress is one of the important mechanisms in the antiviral immune response and innate immunity. Therefore, it would be of interest to summarize the data regarding the oxidative stress in severe COVID-19. In this review, we discuss the role of oxidative and antioxidant mechanisms in severe COVID-19 based on available studies. We also present the role of ROS and RNS in other viral infections in humans and in animal models. Although reactive oxygen and nitrogen species play an important role in the innate antiviral immune response, in some situations, they might have a deleterious effect, e.g., in some coronaviral infections. The understanding of the redox mechanisms in severe COVID-19 disease may have an impact on its treatment.

Using FeNO Measurement in Clinical Asthma Management

Asthma is a common and heterogeneous disease, characterised by lower airway inflammation and airflow limitation. Critical factors in asthma management include establishing an accurate diagnosis and ensuring appropriate selection and dosage of anti-inflammatory therapies. The majority of asthma patients exhibit type 2 (T2) inflammation, with increased interleukin (IL)-4, IL-5, and IL-13 signalling, often with associated eosinophilia. Identifying lower airway eosinophilia with sputum induction improves asthma outcomes, but is time consuming and costly. Increased T2-inflammation leads to upregulation of nitric oxide (NO) release into the airway, with increasing fractional exhaled NO (FeNO) reflecting greater T2-inflammation. FeNO can be easily and quickly measured in the clinic, offering a point of care surrogate measure of the degree of lower airway inflammation. FeNO testing can be used to help confirm an asthma diagnosis, to guide inhaled corticosteroid therapy, to assess adherence to treatment, and to aid selection of appropriate biologic therapy. However, FeNO levels may also be influenced by a variety of intrinsic and extrinsic factors other than asthma, including nasal polyposis and cigarette smoking, and must be interpreted in the broader clinical context rather than viewed in isolation. This review discusses the clinical application of FeNO measurement in asthma care, from diagnosis to treatment selection, and describes its place in current international expert guidelines.

Boosting nitric oxide in stress and respiratory infection: Potential relevance for asthma and COVID-19

Nitric oxide (NO) is a ubiquitous signaling molecule that is critical for supporting a plethora of processes in biological organisms. Among these, its role in the innate immune system as a first line of defense against pathogens has received less attention. In asthma, levels of exhaled NO have been utilized as a window into airway inflammation caused by allergic processes. However, respiratory infections count among the most important triggers of disease exacerbations. Among the multitude of factors that affect NO levels are psychological processes. In particular, longer lasting states of psychological stress and depression have been shown to attenuate NO production. The novel SARS-CoV-2 virus, which has caused a pandemic, and with that, sustained levels of psychological stress globally, also adversely affects NO signaling. We review evidence on the role of NO in respiratory infection, including COVID-19, and stress, and argue that boosting NO bioavailability may be beneficial in protection from infections, thus benefitting individuals who suffer from stress in asthma or SARS-CoV-2 infection.

Utility of fractional exhaled nitric oxide in interstitial lung disease

The majority of interstitial lung diseases (ILDs) develop rapidly and are associated with a poor prognosis. Therefore, new noninvasive markers are needed to guide the classification and prognostication of ILD. We enrolled 95 patients with ILD, including dermatomyositis-associated ILD (n =69), Sjögren's syndrome-associated ILD (n= 7), mixed connective tissue disease-associated ILD (n= 9), idiopathic pulmonary fibrosis (n= 5) and hypersensitivity pneumonitis (n= 5), 82 patients with connective tissue disease but without ILD as well as 24 healthy controls, then evaluated fractional exhaled nitric oxide (FeNO50; 50 ml s^-1) (Bisenkovet al2006Vestn. Khir. Im. I. I. Grek.1659-14), pulmonary function and high-resolution computed tomography (HRCT) scores. Blood samples were analyzed and bronchoalveolar lavage fluid parameters were measured. There was no significant difference in FeNO50 values between different subgroups of ILD patients or between different subgroups of ILD patients and healthy controls. However, we found that FeNO50 was negatively correlated with the HRCT score and positively correlated with forced vital capacity. FeNO50 values did not play a clinical role in the diagnosis, differential diagnosis or prognostication of ILD.

Nitric Oxide to Fight Viral Infections

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) that has quickly and deeply affected the world, with over 60 million confirmed cases. There has been a great effort worldwide to contain the virus and to search for an effective treatment for patients who become critically ill with COVID-19. A promising therapeutic compound currently undergoing clinical trials for COVID-19 is nitric oxide (NO), which is a free radical that has been previously reported to inhibit the replication of several DNA and RNA viruses, including coronaviruses. Although NO has potent antiviral activity, it has a complex role in the immunological host responses to viral infections, i.e., it can be essential for pathogen control or detrimental for the host, depending on its concentration and the type of virus. In this Essay, the antiviral role of NO against SARS-CoV, SARS-CoV-2, and other human viruses is highlighted, current development of NO-based therapies used in the clinic is summarized, existing challenges are discussed and possible further developments of NO to fight viral infections are suggested.

Exhaled nitric oxide measurement before pediatric adenotonsillectomy: A feasibility study

BACKGROUND

Exhaled nitric oxide (eNO) is a known biomarker for the diagnosis and monitoring of bronchial hyperreactivity in adults and children.

AIMS

To investigate the potential role of eNO measurement for predicting perioperative respiratory adverse events in children, we sought to determine its feasibility and acceptability before adenotonsillectomy.

METHODS

We attempted eNO testing in children, 4-12 years of age, immediately prior to admission for outpatient adenotonsillectomy. We used correlations between eNO levels and postoperative adverse respiratory events to make sample size predictions for future studies that address the predictability of the device.

RESULTS

One hundred and three (53%) of 192 children were able to provide an eNO sample. The success rate increased with age from 23% (9%-38%) at age 4 to over 85% (54%-98%) after age 9. Using the eNO normal value (<20 ppb) as a cutoff, an expected sample size to detect a significant difference between children with and without adverse events is 868, assuming that respiratory adverse events occur in 29% of children.

CONCLUSIONS

eNO testing on the day of surgery has limited feasibility in children younger than 7 years of age. The most common reason for failure was inadequate physical performance while interacting with the testing device. The role of this respiratory biomarker in the context of perioperative outcomes for pediatric adenotonsillectomy remains unknown and should be further studied with improved technologies.

Influence of acute high-intensity exercise on salivary nitric oxide levels

This study, employing an exercise versus control crossover design, was conducted to investigate the influence of acute high-intensity exercise on salivary nitric oxide (NO) levels. Nine healthy males (aged 23.8 ± 1.4 years) performed ergometer exercise at 80%VO_2peak for 60 min, whereas controls sat at rest for 60 min. Saliva samples were collected before (Pre: 0800 h) and after (Post 0-h: 0900 h, Post 1-h: 1000 h, Post 2-h: 1100 h, Post 3-h: 1200 h) the interventions. Salivary NO levels were determined by colorimetric assay. It was found that the salivary NO levels in controls were decreased (P < 0.05) at Post 0-h (-94 ± 15), Post 1-h (-80 ± 20), Post 2-h (-92 ± 34) and Post 3-h (-145 ± 39) relative to the Pre values. Under exercise conditions, salivary NO levels did not change after high-intensity ergometer exercise relative to the Pre values. Thus, the response of salivary NO levels appeared to differ between high-intensity ergometer exercise and inactivity, that exercise-related stress induces the production of salivary NO.

Beetroot juice supplementation for the prevention of cold symptoms associated with stress: A proof-of-concept study

OBJECTIVES

Psychological stress has been linked to common cold symptoms. Nitric oxide (NO) is part of the first line of epithelial defense against pathogens, and beetroot juice is a source of dietary nitrate that increases NO availability. We therefore tested whether beetroot juice protects against cold symptoms in a period of sustained acute stress.

DESIGN

Seventy-six students, 16 of these with asthma, were randomly assigned to seven daily doses of beetroot juice or no supplementation control during their final exams.

METHODS

Participants completed stress ratings, a cold symptom questionnaire, and exhaled NO measurements at a low-stress period and two periods during their final exams, with one questionnaire follow-up assessment seven days after finals.

RESULTS

Beetroot juice was associated with reduced symptoms of cold and sickness during and following finals. Those with asthma showed the greatest benefits. Higher exhaled NO was concurrently and prospectively associated with reduced symptomatology.

CONCLUSION

Beetroot juice during periods of psychological stress protects against cold symptoms. Preliminary evidence suggests particular benefits in asthma, which could translate into reduced asthma exacerbations due to respiratory infections. Clinical Trial ID: NCT03159273.

Acute ingestion of beetroot juice increases exhaled nitric oxide in healthy individuals

Background and objective

Nitric oxide (NO) plays an important role in the airways’ innate immune response, and the fraction of exhaled NO at a flow rate of 50mL per second (F_ENO₅₀) has been utilized to capture NO. Deficits in NO are linked to loss of bronchoprotective effects in airway challenges and predict symptoms of respiratory infection. While beetroot juice supplements have been proposed to enhance exercise performance by increasing dietary nitrate consumption, few studies have examined the impact of beetroot juice or nitrate supplementation on airway NO in contexts beyond an exercise challenge, which we know influences F_ENO₅₀.

Methods

We therefore examined the influence of a beetroot juice supplement on F_ENO₅₀ in healthy males and females (n = 38) during periods of rest and in normoxic conditions. F_ENO₅₀, heart rate, blood pressure, and state affect were measured at baseline, 45 minutes, and 90 minutes following ingestion of 70ml beetroot juice (6.5 mmol nitrate). Identical procedures were followed with ingestion of 70ml of water on a control day.

Results

After beetroot consumption, average values of the natural log of F_ENO₅₀ (lnF_ENO₅₀) increased by 21.3% (Cohen’s d = 1.54, p < .001) 45 minutes after consumption and by 20.3% (Cohen’s d = 1.45, p < .001) 90 min after consumption. On the other hand, only very small increases in F_ENO₅₀ were observed after consumption of the control liquid (less than 1% increase). A small subset (n = 4) of participants completed an extended protocol lasting over 3 hours, where elevated levels of F_ENO₅₀ persisted. No significant changes in cardiovascular measures were observed with this small single dose of beetroot juice.

Conclusion

As NO serves a key role in innate immunity, future research is needed to explore the potential clinical utility of beetroot and dietary nitrate to elevate F_ENO₅₀ and prevent respiratory infection.

Exhaled nitric oxide and vascular endothelial growth factor as predictors of cold symptoms after stress

OBJECTIVE

Prior research has demonstrated that psychosocial stress is associated with respiratory infections. Immunologic, endocrine, and cardiovascular predictors of such infections have been explored with varying success. We therefore sought to study the unexplored role of airway mucosal immunity factors, nitric oxide (NO) and vascular endothelial growth factor (VEGF). NO is secreted by airway epithelial cells as part of the first line of defense against bacteria, viruses, and fungi. VEGF is expressed by mast cells in respiratory infections and recruits immune cells to infected sites, but in excess lead to vulnerability of the airway epithelium.

METHODS

In this proof-of-concept study we measured exhaled NO, exhaled breath condensate (EBC) VEGF, salivary VEGF, and salivary cortisol in 36 students undergoing final academic examinations at three occasions: a low-stress baseline during the term, an early phase of finals, and a late phase of finals. Participants also reported on cold symptoms at these time points and approximately 5 and 10days after their last academic examination.

RESULTS

Higher baseline NO was associated with fewer cold symptoms after stress, whereas higher baseline VEGF in EBC and saliva were associated with more cold symptoms after stress. Perceived stress at baseline as well as salivary VEGF and cortisol late in the finals also contributed to the prediction of later cold symptoms.

CONCLUSION

Basal levels of NO and VEGF may inform about mucosal immunocompetence and add to preventative treatments against airway infections from periods of stress in daily life.

A novel biomarker associated with distress in humans: calcium-binding protein, spermatid-specific 1 (CABS1)

Calcium-binding protein spermatid-specific 1 (CABS1) is expressed in the human submandibular gland and has an anti-inflammatory motif similar to that in submandibular rat 1 in rats. Here, we investigate CABS1 in human saliva and its association with psychological and physiological distress and inflammation in humans. Volunteers participated across three studies: 1) weekly baseline measures; 2) a psychosocial speech and mental arithmetic stressor under evaluative threat; and 3) during academic exam stress. Salivary samples were analyzed for CABS1 and cortisol. Additional measures included questionnaires of perceived stress and negative affect; exhaled nitric oxide; respiration and cardiac activity; lung function; and salivary and nasal inflammatory markers. We identified a CABS1 immunoreactive band at 27 kDa in all participants and additional molecular mass forms in some participants. One week temporal stability of the 27-kDa band was satisfactory (test-retest reliability estimate = 0.62-0.86). Acute stress increased intensity of 18, 27, and 55 kDa bands; 27-kDa increases were associated with more negative affect and lower heart rate, sympathetic activity, respiration rate, and minute ventilation. In both acute and academic stress, changes in 27 kDa were positively associated with salivary cortisol. The 27-kDa band was also positively associated with VEGF and salivary leukotriene B4 levels. Participants with low molecular weight CABS1 bands showed reduced habitual stress and negative affect in response to acute stress. CABS1 is readily detected in human saliva and is associated with psychological and physiological indicators of stress. The role of CABS1 in inflammatory processes, stress, and stress resilience requires careful study.

Daily life negative mood and exhaled nitric oxide in asthma

BACKGROUND

Psychosocial stress and negative affect have been linked to asthma exacerbations, but longitudinal studies demonstrating a daily life association between negative affect and airway nitric oxide are missing.

OBJECTIVE

The longitudinal association between negative mood fluctuations, exhaled nitric oxide, and lung function in asthma was examined.

METHODS

Self-assessments of the fraction of exhaled nitric oxide (FeNO), spirometry (forced expiratory volume in the first second, FEV1), negative mood, and daily activities were obtained from 20 patients with asthma for 2 months, resulting in 1108 assessments for the analyses (approximately 55 per patient). Concurrent and prospective associations between FeNO, FEV1, and negative mood were analyzed using mixed effects regression models for longitudinal data.

RESULTS

Negative mood was positively associated with changes in FeNO during the same day, and to a stronger extent when prior day negative mood was included in the prediction. FeNO and negative mood were positively associated with same-day FEV1, with the latter relation being partially mediated by changes in FeNO. Associations between FeNO and FEV1 were stronger in younger patients, with earlier onset of asthma, or with lower asthma control. Findings were not changed when controlling for physical activity, medication, cold symptoms, air pollution, and hours spent outside.

CONCLUSION

Daily life changes of negative mood in asthma are positively associated with FeNO changes and FeNO increases are associated with a mild bronchodilation. These findings indicate that psychological influences need to be considered when using FeNO as indicator of airway inflammation and guide for treatment decisions.

Effects of academic exam stress on nasal leukotriene B4 and vascular endothelial growth factor in asthma and health

OBJECTIVE

To examine the effect of final exam stress on the concentrations of leukotriene B4 (LTB4) and vascular endothelial growth factor (VEGF) in the upper airways among healthy and asthmatic individuals.

METHOD

Nasal samples were collected from 12 individuals with asthma and 23 healthy controls early and late in a final exam period, and during a low-stress period in the semester. We determined LTB4 and VEGF concentrations using Enzyme-Linked Immunoassays.

RESULTS

Mixed effects analysis of variance models showed that asthmatic participants with allergies in contrast to healthy individuals experienced a decrease in nasal LTB4 during the final exam period as compared to mid-semester (low stress period). There were no significant changes in nasal VEGF across the observation period. Changes in nasal LTB4 and VEGF were not associated with salivary cortisol, exhaled nitric oxide, or spirometric lung function.

CONCLUSIONS

Our results suggest that nasal LTB4 concentrations change in periods of psychological stress for asthmatic individuals with allergies.

Rhinovirus in the Pathogenesis and Clinical Course of Asthma

In healthy individuals, human rhinovirus (HRV) infections are the major cause of the common cold. These are generally uncomplicated infections except for occasional cases of otitis media or sinusitis. In individuals with asthma, however, HRV infections can have a major impact on disease development and progression. HRV-induced wheezing illnesses in early life are a significant risk factor for subsequent development of asthma, and growing evidence supports a role of recurrent HRV infections in the development and progression of several aspects of airway remodeling in asthma. In addition, HRV infections are one of the most common triggers for acute exacerbations of asthma, which represent a major burden to health-care systems around the world. None of the currently prescribed medications for asthma are effective in preventing or reversing asthma development and airway remodeling or are ideal for treating HRV-induced exacerbations of asthma. Thus, a better understanding of the role of HRV in asthma is important if we are to develop more effective therapies. In the past decade, we have gained new insights into the role of HRV infections in the development and progression of airway remodeling as well as a new appreciation for the proinflammatory and host defense responses to HRV infections that may help to regulate susceptibility to asthma exacerbations. This article reviews the current understanding of the role HRV infections play in the pathogenesis of asthma and identifies possible avenues to new therapeutic strategies for limiting the effects of HRV infections in asthma.

Exhaled nitric oxide decreases during exercise in non-asthmatic children

INTRODUCTION

Exhaled nitric oxide (FENO) measurements are recommended to be performed before spirometry and exercise challenge tests because forced breathing might influence FENO values. Information on the effect of exercise on FENO is lacking in non-asthmatic children.

AIM

  To investigate the effect on FENO of a standardized exercise challenge test on a treadmill in non-asthmatic children with and without allergic rhinoconjunctivitis (AR) symptoms.

METHODS

From the case-control study 'Asthma and allergy among school children in Nordland', 330 non-asthmatic pupils age 8-16 years were enrolled. FENO was measured at baseline and at 1 min and 30 min after exercise challenge test by the single breath technique with EcoMedics Exhalazer® (Eco Physics, Duernten, Switzerland).

RESULTS

Pair-wise comparison of FENO from baseline demonstrated a highly significant reduction in FENO post-exercise for all children at 1 min (27.4%) and at 30 min (16.1%) (P < 0.001). The AR group had a significantly higher decline in FENO value at 1 min post-exercise compared to the non-AR group, 4.2 parts per billion (ppb) vs 2.6 ppb (P < 0.001). Decline in FENO immediately post-exercise was more significant if baseline FENO was ≥ 20 ppb; mean reduction 9.9 (95% CI: 8.7-11.4) ppb.

CONCLUSION

FENO is reduced by 27.4% immediately after a standardized treadmill exercise test in non-asthmatic children. Pupils reporting AR symptoms demonstrate a larger decline in FENO value at 1 min post-exercise compared to pupils without AR symptoms. These findings confirm that children should refrain from physical activity before FENO measurement.

Measurement of nasal and fractional exhaled nitric oxide in children with upper airway inflammatory disease: Preliminary results

OBJECTIVES

To assess the clinical significance of nasal nitric oxide (nNO) and fractional exhaled nitric oxide (FeNO) concentrations in children with upper airway inflammatory disease.

METHODS

Fifteen healthy children, 30 with allergic rhinitis (AR), 10 with non-allergic rhinitis (NAR), and 30 with sleep disordered breathing (SDB) were enrolled. The FeNO and nNO concentrations were measured non-invasively using a NIOX MINO system.

RESULTS

Both nNO and FeNO were significantly higher in children with AR than in healthy children (P=0.000 and P=0.000, respectively). Compared to healthy children, nNO was also significant higher in children with NAR (P=0.011) or SDB (P=0.027). In contrast, FeNO did not differ from controls in children with NAR or SDB.

CONCLUSIONS

Our data suggest that nNO has potential value for diagnosing upper airway inflammation. Moreover, elevated FeNO distinguishes allergic from non-allergic rhinitis.

Virus-induced modulation of lower airway diseases: pathogenesis and pharmacologic approaches to treatment

Uncomplicated upper respiratory viral infections are the most common cause of days lost from work and school and exert a major economic burden. In susceptible individuals, however, common respiratory viruses, particularly human rhinoviruses, also can have a major impact on diseases that involve the lower airways, including asthma, chronic obstructive pulmonary diseases (COPD) and cystic fibrosis (CF). Respiratory virus-induced wheezing illnesses in early life are a significant risk factor for the subsequent development of asthma, and virus infections may also play a role in the development and progression of airway remodeling in asthma. It is clear that upper respiratory tract virus infections can spread to the lower airway and trigger acute attacks of asthma, COPD or CF. These exacerbations can be life-threatening, and exert an enormous burden on health care systems. In recent years we have gained new insights into the mechanisms by which respiratory viruses may induce acute exacerbations of lower airway diseases, as well as into host defense pathways that may regulate the outcomes to viral infections. In the current article we review the role of viruses in lower airway diseases, including our current understanding on pathways by which they may cause remodeling and trigger acute exacerbations. We also review the efficacy of current and emerging therapies used to treat these lower airway diseases on the outcomes due to viral infection, and discuss alternative therapeutic approaches for the management of virus-induced airway inflammation.

Increases in exhaled nitric oxide after acute stress: association with measures of negative affect and depressive mood

BACKGROUND

Increases in fractional exhaled nitric oxide (FeNO) have been observed after acute laboratory stress, which could indicate a strengthening of immune defenses in acute stress because of the quick onset of the response and the role of nitric oxide in airway-protective functions. In addition, because sustained psychological distress and depression are known to deteriorate immune defenses systems, they may dampen the FeNO response to acute stress.

METHODS

FeNO and negative affect were measured before and after a speech and mental arithmetic stressor. We examined the association of stress-induced FeNO changes with momentary negative affect and questionnaires of perceived stress, anxious mood, and depressive mood in 39 asthma patients and 41 healthy controls.

RESULTS

FeNO increased from baseline to stress in participants with asthma (from 3.38 [0.102] to 3.46 [0.103] ln(ppb)) and controls (2.86 [0.098] to 2.92 [0.099]; F(4,141) = 3.26, p = .014), but the magnitude of the FeNO response did not differ between groups (F < 1). Only low levels of depressive mood were associated with FeNO increases after stress (most pronounced at 0 minute poststress; t(76) = 3.87, p < .001). In contrast, only higher perceived stress was associated with FeNO increases (most pronounced at 0 minute poststress; t(75) = 4.09, p < .001), and momentary negative affect was associated with higher FeNO throughout assessments (β = 0.08, t(114) = 8.27, p = .005). Associations of FeNO with psychological variables were largely unrelated to asthma status and inhaled corticosteroid use.

CONCLUSIONS

Depressive mood is associated with a reduced mobilization of airway nitric oxide in acute stress, whereas other indicators of negative affect are positively associated with overall FeNO levels and reactivity.

Epidemiology of virus-induced asthma exacerbations: with special reference to the role of human rhinovirus

Viral respiratory infections may be associated with the virus-induced asthma in adults as well as children. Particularly, human rhinovirus is strongly suggested a major candidate for the associations of the virus-induced asthma. Thus, in this review, we reviewed and focused on the epidemiology, pathophysiology, and treatment of virus-induced asthma with special reference on human rhinovirus. Furthermore, we added our preliminary data regarding the clinical and virological findings in the present review.

Role of Fat-Soluble Vitamins A and D in the Pathogenesis of Influenza: A New Perspective

Reduced exposure to solar radiation, leading to a deficiency of vitamin D and hence impaired innate immunity, has been suggested as a trigger for influenza viral replication and as an explanation of seasonal influenza. Although this hypothesis accounts for many unexplained facts about the epidemiology of influenza, gaps remain in understanding the pathogenesis and manifestations of the disease. Several observations suggest a role for vitamin A compounds (retinoids) in the disease. This paper presents a new model of the etiopathogenesis of influenza, suggesting that host resistance and susceptibility depend importantly on the ratio of vitamin D to vitamin A activity. Retinoid concentrations within normal physiological limits appear to inhibit influenza pathogenesis whereas higher background concentrations (i.e., very low vitamin D : A ratios) increase the risk of severe complications of the disease. There is also evidence that influenza-induced or preexisting liver disease, diabetes, and obesity worsen the severity of infection, possibly via liver dysfunction and alterations in retinoid metabolism. The model could be tested by determining the presence of retinoids in the secretions of patients with influenza and by studies of retinoid profiles in patients and controls. Potential strategies for prevention and treatment are discussed.

Models of contrasting strategies of rhinovirus immune manipulation

Rhinoviruses, consisting of well over one hundred serotypes that cause a plurality of common colds, are completely cleared by the host immune system after causing minimal cell death, but often without inducing long-term immune memory. We develop mathematical models of two kinds of rhinoviruses, the major group and minor group, that use different receptors to enter target cells. Roughly the 90 serotypes in the major group bind to ICAM-1, a molecule that is upregulated on antigen-presenting cells, and alter the timing, location and type of the immune response. The 12 members of the minor group do not so modulate the response. Our model predicts similar virus dynamics for the major and minor groups but with quite different underlying mechanisms. Over a range of key parameters that quantify immune manipulation, disease outcomes lie within a triangle in the plane describing damage and memory, of which the major and minor group form two corners. This model of infection by a highly adapted and low virulence virus provides a starting point for understanding the development of asthma and other pathologies.

T lymphocytes promote the antiviral and inflammatory responses of airway epithelial cells

HYPOTHESIS

T cells modulate the antiviral and inflammatory responses of airway epithelial cells to human rhinoviruses (HRV).

METHODS

Differentiated primary human nasal epithelial cells (HNEC) grown on collagen-coated filters were exposed apically to HRV14 for 6 h, washed thoroughly and co-cultured with anti-CD3/CD28 activated T cells added in the basolateral compartment for 40 h.

RESULTS

HRV14 did not induce IFNγ, NOS2, CXCL8 and IL-6 in HNEC, but enhanced expression of the T cell attractant CXCL10. On the other hand, HNEC co-cultured with activated T cells produced CXCL10 at a level several orders of magnitude higher than that induced by HRV14. Albeit to a much lower degree, activated T cells also induced CXCL8, IL-6 and NOS2. Anti-IFNγ antibodies and TNF soluble receptor completely blocked CXCL10 upregulation. Furthermore, a significant correlation was observed between epithelial CXCL10 mRNA expression and the amounts of IFNγ and TNF secreted by T cells. Likewise, increasing numbers of T cells to a constant number of HNEC in co-cultures resulted in increasing epithelial CXCL10 production, attaining a plateau at high IFNγ and TNF levels. Hence, HNEC activation by T cells is induced mainly by IFNγ and/or TNF. Activated T cells also markedly inhibited viral replication in HNEC, partially through activation of the nitric oxide pathway.

CONCLUSION

Cross-talk between T cells and HNEC results in activation of the latter and increases their contribution to airway inflammation and virus clearance.

Epithelial cells and airway diseases

The airway epithelial cell is the initial cell type impacted both by inhaled environmental factors, such as pathogens, allergens, and pollutants, and inhaled medications for airway diseases. As such, epithelial cells are now recognized to play a central role in the regulation of airway inflammatory status, structure, and function in normal and diseased airways. This article reviews our current knowledge regarding the roles of the epithelial cell in airway inflammation and host defense. The interactions of inhaled environmental factors and pathogens with epithelial cells are also discussed, with an emphasis on epithelial innate immune responses and contributions of epithelial cells to immune regulation. Recent evidence suggesting that epithelial cells play an active role in inducing several of the structural changes, collectively referred to airway remodeling, seen in the airways of asthmatic subjects is reviewed. Finally, the concept that the epithelium is a major target for the actions of a number of classes of inhaled medications is discussed, as are the potential mechanisms by which selected drugs may alter epithelial function.

Determinants of exhaled nitric oxide levels (FeNO) in childhood atopic asthma: evidence for neonatal respiratory distress as a factor associated with low FeNO levels

BACKGROUND

In allergic asthmatic children exhaled nitric oxide (FeNO) levels are related to eosinophilic inflammation by correlation analysis. Whether FeNO can be modified by factors potentially influencing the natural history of asthma in early life is not known.

OBJECTIVE

To evaluate the frequency of anamnestic factors influencing the natural history of asthma and to identify potential determinants for elevated or low FeNO levels by multivariate analysis.

METHODS

One hundred seventy-one children with mild-moderate asthma were stratified according to their FeNO levels into three groups: low (<20 ppb), mid (20-40 ppb), and high (>40 ppb). The frequency of nine anamnestic factors together with indices of allergic sensitization (total and allergen-specific immunoglobulin E [IgE], blood eosinophil counts) and of airflow limitation (forced expiratory volume in one second [FEV(1)]% predicted) were evaluated. Results. Among factors related to the patient history, neonatal respiratory distress was reported only in children with low FeNO levels, whereas this factor was never reported in children with mid-to-high FeNO levels (p = .008). As compared with low FeNO group, mid and high FeNO groups showed higher eosinophil counts and a tendency to have lower FEV(1) values. By multivariate analysis, four factors (eosinophils >300 cells/mm(3), cat-specific IgE, house dust mites [HDM]-specific IgE, FEV(1) ≤ 86% predicted) turned out to be significantly associated with mid-high FeNO levels and two factors (eosinophils >600 cells/mm(3), total IgE >355 kU/L) with high FeNO levels.

CONCLUSIONS

Besides confirming the well-known tight association between blood eosinophilia and/or allergic sensitization and FeNO, these data provide new evidence for neonatal respiratory distress as potential factor associated with low FeNO levels in childhood atopic asthma.

A single dose of Sildenafil does not enhance FeNO: a randomised, cross-over and placebo-controlled study

Monitoring of asthma control can be performed with different means including measurement of the concentration of nitric oxide (NO) in exhaled air. Due to its action on the NO-metabolism; we hypothesized that the intake of Sildenafil might augment and falsify the NO-values in exhaled air of subjects taking the drug to treat erectile dysfunction. This randomised, placebo-controlled cross-over study including 10 male non-asthmatic volunteers taking a single dose of 50 mg Sildenafil did not confirm this assumption in non-asthmatic subjects. We cannot think of any reason why asthmatics should behave differently. On the basis of these results, it does not seem necessary to ask asthma patients with elevated NO-values if they had taken any selective inhibitor of the cGMP-specific phosphodiesterase Type 5 as Sildenafil prior to the test.

Exhaled nitric oxide as a predictor of exacerbation in children with moderate-to-severe asthma: a prospective, 5-month study

BACKGROUND

Inhaled corticosteroids (ICSs) are recommended as the first line of treatment in children with moderate-to-severe asthma. Exhaled nitric oxide (ENO) has been proposed as a clinically useful marker of control that might help identify patients in whom ICS dose may be safely reduced.

OBJECTIVE

To evaluate the ability of ENO to predict future asthma exacerbations in children with moderate-to-severe asthma undergoing ICS tapering.

METHODS

This is an observational study with no control group. ENO was measured biweekly for 14 weeks in 32 children with moderate-to-severe asthma who were undergoing ICS tapering. Clinical evaluations and spirometry were performed concomitantly, and families kept daily diaries to record symptoms between visits. We used generalized estimating equations to model the In (odds) of an asthma exacerbation in the subsequent 2-week interval as a function of ENO level at the start of the interval while adjusting for age, sex, asthma severity, and current medication use.

RESULTS

We were able to successfully lower ICS doses in 10 (56%) of the 18 children with moderate asthma and in 3 (21%) of the 14 children with severe asthma. In 83 of the 187 follow-up clinical evaluations, children were determined to have had an exacerbation during the preceding 2 weeks. ENO levels, whether expressed as a continuous variable or dichotomized, were not associated with future risk for exacerbations in either unadjusted or adjusted models.

CONCLUSION

ENO was not a useful clinical predictor of future asthma exacerbations for children with moderate-to-severe asthma undergoing ICS tapering.

[Atopic dermatitis aggravates the allergic airways inflammation in acute viral bronchiolitis]

INTRODUCTION

Exhaled nitric oxide (FeNO) is a putative non-invasive marker of eosinophilic airway inflammation with a good predictive value for allergic asthma in preschool children. The aim of the present study was to compare FeNO after acute viral bronchiolitis (AVB) in children aged less than 2 years without atopic dermatitis (AD) vs those with atopic dermatitis, as well as children with AD without any history of AVB.

METHODS

Forty-two children (mean age +/- SD: 12.3 +/- 5.2 months; range 5.0-23.5; sex-ratio M: F=1.3: 1) were included in this prospective study, > 8 wks after an episode of AVB. The patients' atopic status was assessed both by clinical phenotype and IgE- mediated response to inhaled and/or food allergens. FeNO (ppb) was measured off-line by the chemoluminescence method on samples obtained from gas collected in a balloon during tidal breathing.

RESULTS

There was a significant difference between the AVB/AD (23.4 +/- 14.3 ppb, n=15) vs the AVB without AD group (13.5 +/- 10. 1 ppb, n=13) or the AD without AVB group (11.0 +/- 8.3 ppb, n=14). Maternal feeding for more than 2 months decreased FeNO by 50%.

CONCLUSION

Atopic children below 2 years with AD produce more NO after AVB than non-atopic children or atopic children without any history of AVB. Maternal feeding decreases FeNO.

Nitric oxide inhibits human rhinovirus-induced transcriptional activation of CXCL10 in airway epithelial cells

BACKGROUND

Human rhinovirus (HRV) infections trigger exacerbations of asthma and chronic obstructive pulmonary disease. Nitric oxide (NO) inhibits HRV replication in human airway epithelial cells and suppresses HRV-induced epithelial production of several cytokines and chemokines.

OBJECTIVE

We sought to delineate the mechanisms by which NO inhibits HRV-induced epithelial production of CXCL10, a chemoattractant for type 1 T cells and natural killer cells.

METHODS

Primary human bronchial epithelial cells or cells of the BEAS-2B human bronchial epithelial cell line were exposed to HRV-16 in the presence or absence of the NO donor 3-(2-hydroxy-2-nitroso-1-propylhydrazino)-1-propanamine (PAPA NONOate). A cGMP analogue and an inhibitor of soluble guanylyl cyclase were used to examine the role of the cyclic guanosine monophosphate (cGMP) pathway in the actions of NO. BEAS-2B cells were transfected with CXCL10 promoter-luciferase constructs and the effects of PAPA NONOate were examined to study mechanisms of transcriptional regulation. Electrophoretic mobility shift assays were also used.

RESULTS

PAPA NONOate inhibited HRV-16-induced increases in CXCL10 mRNA and protein. Inhibition of CXCL10 production occurred through a cGMP-independent pathway. PAPA NONOate inhibited HRV-16-induced CXCL10 transcription by blocking nuclear translocation, binding, or both of both nuclear factor kappaB and IFN response factors (IRFs) to their respective recognition elements in the CXCL10 promoter.

CONCLUSIONS

NO inhibits HRV-16-induced production of CXCL10 by inhibiting viral activation of nuclear factor kappaB and of IRFs, including IRF-1, through a cGMP-independent pathway. The broad-ranging inhibition of HRV-induced epithelial cytokine and chemokine production by NO suggests a potential therapeutic utility of NO donors in viral exacerbations of asthma and chronic obstructive pulmonary disease.

Viral infections in patients with chronic obstructive pulmonary disease

PURPOSE OF REVIEW

Chronic obstructive pulmonary disease is a major cause of morbidity and mortality worldwide. There is increasing evidence that implicates viral infections as a major risk factor for exacerbations of chronic obstructive pulmonary disease. Recent studies have attempted to better characterize the epidemiology of viral infections in chronic obstructive pulmonary disease, identify unique clinical manifestations of virus-associated exacerbations, and develop new diagnostic tools and treatments.

RECENT FINDINGS

Rhinovirus, the organism most often responsible for causing the common cold, is also the most common infectious cause of chronic obstructive pulmonary disease exacerbations. Coronavirus, influenza, respiratory syncytial virus, parainfluenza, adenovirus, and metapneumovirus are other important viral causes of chronic obstructive pulmonary disease exacerbations. These exacerbations can be severe with prolonged recovery times. Although PCR technology has dramatically increased the detection rate of viruses in patients with chronic obstructive pulmonary disease, it does not differentiate infection from colonization. The use of biomarkers represents an exciting new potential diagnostic tool that may lend new insights into the pathogenesis of viral infections in patients with chronic obstructive pulmonary disease.

SUMMARY

Despite strong epidemiologic evidence linking respiratory virus infection to exacerbations of chronic obstructive pulmonary disease, many of the cellular and molecular mechanisms by which viruses cause exacerbations remain undetermined. Future research efforts to understand these mechanisms would aid the development of novel therapeutics to reduce the morbidity and mortality of this disease.

The value of FeNO measurement in asthma management: the motion for Yes, it's NO--or, the wrong end of the Stick!

The utility of measurements of exhaled nitric oxide (FeNO) will likely depend on context, being most helpful in moderate and severe asthma, rather than mild asthmatics and community based studies. Atopy on its own is a cause of elevation in FeNO. Adult and paediatric studies have clearly established that measurement of some aspect of airway inflammation is part of state of the art management of asthma, but it is as yet unclear which of several techniques is most useful. The relationship between FeNO and sputum eosinophils is relatively loose, but this does not preclude it being a useful test in clinical practice. In fact, there are only poor correlations between sputum, proximal mucosal, and distal eosinophils, and the importance of these different compartments is unclear. A low FeNO in the setting of supposedly poorly controlled asthma should cast doubt on the diagnosis. We certainly cannot treat an isolated elevation in FeNO, which may be due to a simple viral cold, or constitutional. If FeNO is elevated, particularly if asthma is uncontrolled, it suggests an imbalance between anti-inflammatory therapy and pro-inflammatory environmental influences. Inadequate anti-inflammatory therapy may be due to the prescribed dose being too low; the drug delivery device not being used correctly; or the medication not being taken. Adverse pro-inflammatory environmental influences driving up FeNO include IgE and non-IgE mediated allergen sensitivity in the home, and even in the child's school. Novel technology allows home monitoring of FeNO, but the role of these devices is less clear. Although more data is needed properly to define the role of FeNO measurements in clinical practice, there is sufficient data already published to conclude that 'inflammometry' is an important part of asthma management at the more severe end of the spectrum, and that FeNO measurements are probably the most useful at the moment.

Exhaled nitric oxide: independent effects of atopy, smoking, respiratory tract infection, gender and height

Measurement of exhaled nitric oxide is widely used in respiratory research and clinical practice, especially in patients with asthma. However, interpretation is often difficult, due to common interfering factors, and little is known about interactions between factors. We assessed the influences and interactions of factors such as smoking, respiratory tract infections and respiratory allergy concerning exhaled nitric oxide values, with the aim to derive a scheme for adjustment. We studied 897 subjects (514 females, 383 males; mean age+/-standard deviation 34.5+/-13.0 years) with and without respiratory allergy (allergic rhinitis and/or asthma), smoking and respiratory tract infection. Logarithmic nitric oxide levels were described by an additive model comprising respiratory allergy, smoking, respiratory tract infection, gender and height (p0.001 each), without significant interaction terms. Geometric mean was 17.5ppb in a healthy female non smoker of height 170cm, whereby respiratory allergy corresponded to a change by factor 1.50, smoking 0.63, infection 1.24, male gender 1.17, and each 10cm increase (decrease) in height to 1.11 (0.90). Factors were virtually identical when excluding asthma and using the category allergic rhinitis instead of respiratory allergy (n=863). Within each category formed by combinations of these different predictors, the range of residual variation was approximately constant. We conclude that the factors influencing exhaled nitric oxide, which we analyzed, act independently of each other. Thus, circumstances such as smoking and respiratory tract infection do not appear to affect the usefulness of exhaled nitric oxide, provided that appropriate factors for adjustment are applied.

Upper airway viral infections

Upper airway viral infections (URI) are a major cause of absence from school and work. Although morbidity is low in most of the subjects, the complications of URI, including otitis media, sinusitis and exacerbations of asthma and chronic obstructive pulmonary disease (COPD) have an enormous health impact. Despite the major health care consequences associated with these complications, our understanding of how URI trigger upper airway symptoms and cause exacerbations of lower airway diseases remains limited. This article reviews our current understanding of the pathogenesis of URI, and of viral exacerbations of asthma and COPD, and considers host defense parameters that may regulate susceptibility to disease exacerbations. We will also consider current and potential therapeutic approaches for the treatment of URI and their lower airway complications.

Viral-associated exacerbations of asthma and COPD

Exacerbations of asthma and chronic obstructive pulmonary disease are major burdens on the healthcare system, and contribute significantly to the mortality and morbidity associated with these diseases. Upper respiratory viral infections are associated with the majority of such disease exacerbations. The past few years have seen advances in the mechanisms by which viral infections induce pro-inflammatory chemokine production, and in our understanding of host antiviral and anti-inflammatory defence pathways that might regulate responses to infection. A more comprehensive understanding of the molecular basis of these processes could elucidate new therapeutic approaches to reduce the devastating impact that these exacerbations have on quality of life and healthcare costs.

Essential role of nitric oxide in VEGF-induced, asthma-like angiogenic, inflammatory, mucus, and physiologic responses in the lung

VEGF, nitric oxide (NO), inflammation, and vascular- and extravascular remodeling coexist in asthma and other disorders. In these responses, VEGF regulates angiogenesis. VEGF also induces inflammation and remodeling. The mechanisms of the latter responses have not been defined, however. We hypothesized that VEGF-induces extravascular tissue responses via NO-dependent mechanisms. To evaluate this hypothesis, we compared the effects of transgenic VEGF165 in lungs from normal mice, mice treated with pan-NO synthase (NOS) or endothelial NOS (eNOS) inhibitors, and mice with null mutations of inducible NOS (iNOS) or eNOS. These studies demonstrate that VEGF selectively stimulates eNOS and iNOS. They also demonstrate that VEGF induces pulmonary alterations via NO-dependent and -independent mechanisms with angiogenesis, edema, mucus metaplasia, airway hyperresponsiveness, lymphocyte accumulation, dendritic cell hyperplasia and S-nitrosoglutathione reductase stimulation being NO-dependent and dendritic cell activation being NO-independent. Furthermore, they demonstrate that eNOS and iNOS both contribute to these responses. NO/NOS-based interventions may be therapeutic in VEGF-driven inflammation and remodeling.

Role of viral infections in asthma and chronic obstructive pulmonary disease

Substantial evidence implicates common respiratory viral infections in the pathogenesis of asthma and chronic obstructive pulmonary disease (COPD). Children who experience recurrent virally induced wheezing episodes during infancy are at greater risk for developing asthma. In addition, respiratory viral infections are a major trigger for acute exacerbations of both asthma and COPD. Despite the importance of viral infections in asthma and COPD, the mechanisms by which viruses predispose to, or cause exacerbations of, these diseases remain poorly understood. It is clear that viral infections lead to enhanced airway inflammation and can cause airways hyperresponsiveness. The epithelial cell is the principal site of viral infection in the airways and plays a central role in viral modulation of airway inflammation via release of a variety of cytokines, chemokines, and growth factors. The mechanisms by which viral infections modulate epithelial function, therefore, is a topic of intense investigation. The epithelium also contributes to the host innate defense response to viral infection by releasing products that are antiviral and/or can lead to increased recruitment of dendritic cells and lymphocytes. Some evidence supports a role for the epithelial cell in specific immunity, although the response of more conventional cells of the immune system to viral infections is likely the dominant factor in this regard. Although current therapies may help combat virally induced disease exacerbations, they are less than ideal. A better understanding of the mechanisms underlying viral modulation of these diseases, therefore, may lead to new therapeutic approaches.

Strong humming for one hour daily to terminate chronic rhinosinusitis in four days: a case report and hypothesis for action by stimulation of endogenous nasal nitric oxide production

Rhinosinusitis is an inflammation or infection of the nose and air pockets (sinuses) above, below and between the eyes which connect with the back of the nose through tiny openings (ostia). Rhinosinusitis can be caused by bacteria, viruses, fungi (molds) and possibly by allergies. Chronic rhinosinusitis (CRS) is an immune disorder caused by fungi. The immune response produced by eosinophils causes the fungi to be attacked, which leads to damage of the sinus membranes, resulting in full-blown rhinosinusitis symptoms. Gaseous nitric oxide (NO) is naturally released in the human respiratory tract. The major part of NO found in exhaled air originates in the nasal airways, although significant production of NO also takes place in the paranasal sinuses. Proper ventilation is essential for maintenance of sinus integrity, and blockage of the ostium is a central event in pathogenesis of sinusitis. Concentrations of NO in the healthy sinuses are high. Nasal NO is known to be increased 15- to 20-fold by humming compared with quiet exhalation. NO is known to be broadly antifungal, antiviral and antibacterial. This case report shows that a subject hummed strongly at a low pitch ( approximately 130 Hz) for 1h (18 hums per minute) at bedtime the first night, and hummed 60-120 times 4 times a day for the following 4 days as treatment for severe CRS. The humming technique was described as being one that maximally increased intranasal vibrations, but less than that required to produce dizziness. The morning after the first 1-h humming session, the subject awoke with a clear nose and found himself breathing easily through his nose for the first time in over 1 month. During the following 4 days, CRS symptoms slightly reoccurred, but with much less intensity each day. By humming 60-120 times four times per day (with a session at bedtime), CRS symptoms were essentially eliminated in 4 days. Coincidentally, the subject's cardiac arrhythmias (PACs) were greatly lessened. It is hypothesized that strong, prolonged humming increased endogenous nasal NO production, thus eliminating CRS by antifungal means.

Efficacité de Dérinox® chez des patients souffrant d’une rhinite virale évaluée par un PNIF (Peak Nasal Inspiratory Flow)

OBJECTIVES

The aim of this study was to compare the efficacy and tolerance of Dérinox (D) to Rhinofluimucil (R) and placebo (P) in the treatment of common cold, using an objective measure of nasal obstruction, the Peak Nasal Inspiratory Flow (PNIF--Clement Clarke International, Harlow, Angleterre).

PATIENTS AND METHODS

This randomized, double-blind, double-dummy, parallel group study enrolled 354 patients (34 P, 165 D et 155 R) included by 85 general practitioners. The treatment duration was 5 days at usual recommended dosage regimens. PNIF measures were done before drug administration (T0) as well as 15 min and 3 h after each intake. Moreover, nasal obstruction, rhinorrhea and global discomfort were subjectively assessed.

RESULTS

The efficacy of D was superior to that of P and R when comparing PNIF from T0 to T3 h after the first intake. At T15 min, rhinorrhea was significantly improved with both active treatments and global discomfort was significantly improved with D only. Treatment tolerance was satisfactory and comparable between the 3 groups.

CONCLUSION

Efficacy of Dérinox(R) was superior to that of P and R for the improvement of the nasal obstruction (PNIF) between T0 and T3h (main criteria) after the first intake in patients suffering from common cold.