Influence of atopy on exhaled nitric oxide in patients with stable asthma and rhinitis. Ch. Gratziou, M. Lignos, M. Dassiou, Ch. Roussos. #ERS Journals Ltd 1999. ABSTRACT: The level of exhaled NO is increased in patients with allergic asthma and seasonal rhinitis. The aim of this study was to investigate the significance of atopy on NO production in the lower airways.Measurements of exhaled NO were performed in 131 stable asthmatic patients with chronic mild asthma (95 atopics and 36 nonatopics), 72 patients with perennial rhinitis (57 atopics and 15 nonatopics) and 100 healthy controls (20 atopics and 80 nonatopics).Patients with either asthma or rhinitis had higher exhaled NO values (13.3& 1.2 parts per billion (ppb) and 11.7 1.1 ppb) than control subjects (4.8 0.3 ppb, p<0.01). Exhaled NO levels were significantly higher in atopic asthmatics (19 3.6 ppb) compared with nonatopic patients (5.6 0.8 ppb, p<0.001). Similar findings were observed in patients with rhinitis (13.3 1.3 ppb in atopics and 5.8 1.2 ppb in nonatopics, p<0.001). No difference was found in NO levels between atopic and nonatopic control subjects (4.8 0.8 ppb, and 4.5 0.3 ppb).In summary, this study has shown that increased exhaled NO levels are detected only in atopic patients with asthma and/or rhinitis and not in nonatopic patients. These findings may suggest that it is rather the allergic nature of airways inflammation, which is mainly responsible for the higher NO production in the lower airways. Eur Respir J 1999; 14: 897±901.

Exhaled nitric oxide (eNO) has been proposed as a potential indirect marker of lower airway inflammation in asthma. To investigate the existence of lower airways inflammation in allergic rhinitis eNO measurements were performed in 32 patients with symptomatic and asymptomatic seasonal allergic rhinitis early in and out of pollen seasons and in 80 healthy volunteers. To further define how exhaled NO is modified by therapy, NO levels were detected following 1-month treatment with either inhaled steroids or non-steroids therapy with nedocromil. Exhaled NO (mean +/- SE) was significantly elevated in patients with seasonal allergic rhinitis with and without symptoms (24.2 + 2.5 and 13.9 + 2.9 ppb, respectively) as compared to healthy volunteers (4.5 + 0.3 ppb) both in and out of pollen season (21.2 + 2.1 and 9.0 + 1.4 p.p.b., respectively) with a higher increase during the allergen exposure in season. Higher levels of exhaled NO were detected in patients with symptoms, either from the upper or lower airways, and with bronchial hyperreactivity. The increased exhaled NO in symptomatic patients was reduced only by inhaled steroids and not by nedocromil. These findings possibly suggest the existence of lower airway inflammation in both symptomatic and asymptomatic patients with seasonal allergic rhinitis in and out of pollen season. Thus, exhaled NO may be used as a non-invasive index for early detection of lower airway inflammation and for monitoring the optional treatment in patients with seasonal allergic rhinitis.

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Objective To examine the effects of short-term cyclic stretch on apoptosis in alveolar type II cells (A549). To study in vitro the direct influence of alveolar type II cells on mechanical stretch. Methods A549 were treated with different doses of lipopolysaccharide (LPS), 0 ng/ml, 1 ng/ml, 10 ng/ml, 100 ng/ml, 1000 ng/ml, and then A549 were lengthened 5%, 15%, 30% using a FLEXCELL tension unit 4000, a vacuum-driven device that applies strain to cells, which were cultured in six-well plates coated with collagen-I, and 12 cycles/min for 4 hours. Apoptosis was measured using the flow cytometry method that measures annexin V and propidium iodide (PI) staining. The morphological changes of apoptotic cells were observed by transmission electron microscope. Results Apoptosis could be induced in alveolar type II cells (A549) by mechanical stretch. The percentage of annexin V + PI cells increased after being treated with cyclic stretch for 4 hours by 5%, 15%, 30% in all groups. The morphological features of apoptotic cells demonstrated by transmission electron microscope were as follows: shrinkage of the cell, chromatin condensation and aggregation under the nuclear membrane as a crescent or lump, membrane-encapsulated nuclear fragment or cell organ formed by invagination of the cell membrane, and apoptotic body formation followed by vacuolization. Conclusion Apoptosis induced by mechanical stretch and LPS is dose dependent. Mechanical stretch aggravates apoptosis especially in cells treated with LPS. Annexin V and PI double staining is a specific, sensitive, and quantitative method for analyzing apoptotic cells. It is also helpful to clarify the protective mechanism of low-volume ventilation in ARDS. Acknowledgement The study was funded by the 'One Hundred People' project of Shanghai Sanitary Bureau (03-77-20). Introduction Although extrapulmonary ALI/ARDS is a common clinical entity, most animal models used to study this disease are induced by direct lung injuries. Our intention was therefore to investigate whether a condition resembling ALI/ARDS develops during the course of a fecal peritonitis in pigs; in that case experimental peritonitis would also prove as a clinically relevant ARDS model. Methods In 10 anesthetized, mechanically ventilated, and instrumented pigs fecal peritonitis was induced by inoculating autologue feces pellets suspended in saline. Mechanical ventilation was set with VT = 8 ml/kg, FiO 2 to reach a SaO 2 target of >90%, PEEP = 10 cmH 2 O if PaO 2 /FiO 2 > 300 and 12 cmH 2 O if PaO 2 /FiO 2 < 300, and respiratory rate to obtain a PaCO 2 of 35-45 mmHg. Before as well as 12 and 24 hours after peritonitis induction we measured the PaO 2 /FiO 2 ratio, the total compliance of the respiratory system (C), calculated as VT/(P plateau -PEEP) and inspiratory airway resistance (R i ) calculated as (P max -P plateau ) / mean inspiratory flow. Data are mean [range]. Results For data see Table 1. During the course of the 24-hour study period, six of 10 animals developed gas exchange deteriorations consistent w...

Objective To examine the effects of short-term cyclic stretch on apoptosis in alveolar type II cells (A549). To study in vitro the direct influence of alveolar type II cells on mechanical stretch. Methods A549 were treated with different doses of lipopolysaccharide (LPS), 0 ng/ml, 1 ng/ml, 10 ng/ml, 100 ng/ml, 1000 ng/ml, and then A549 were lengthened 5%, 15%, 30% using a FLEXCELL tension unit 4000, a vacuum-driven device that applies strain to cells, which were cultured in six-well plates coated with collagen-I, and 12 cycles/min for 4 hours. Apoptosis was measured using the flow cytometry method that measures annexin V and propidium iodide (PI) staining. The morphological changes of apoptotic cells were observed by transmission electron microscope. Results Apoptosis could be induced in alveolar type II cells (A549) by mechanical stretch. The percentage of annexin V + PI cells increased after being treated with cyclic stretch for 4 hours by 5%, 15%, 30% in all groups. The morphological features of apoptotic cells demonstrated by transmission electron microscope were as follows: shrinkage of the cell, chromatin condensation and aggregation under the nuclear membrane as a crescent or lump, membrane-encapsulated nuclear fragment or cell organ formed by invagination of the cell membrane, and apoptotic body formation followed by vacuolization. Conclusion Apoptosis induced by mechanical stretch and LPS is dose dependent. Mechanical stretch aggravates apoptosis especially in cells treated with LPS. Annexin V and PI double staining is a specific, sensitive, and quantitative method for analyzing apoptotic cells. It is also helpful to clarify the protective mechanism of low-volume ventilation in ARDS. Acknowledgement The study was funded by the 'One Hundred People' project of Shanghai Sanitary Bureau (03-77-20). Introduction Although extrapulmonary ALI/ARDS is a common clinical entity, most animal models used to study this disease are induced by direct lung injuries. Our intention was therefore to investigate whether a condition resembling ALI/ARDS develops during the course of a fecal peritonitis in pigs; in that case experimental peritonitis would also prove as a clinically relevant ARDS model. Methods In 10 anesthetized, mechanically ventilated, and instrumented pigs fecal peritonitis was induced by inoculating autologue feces pellets suspended in saline. Mechanical ventilation was set with VT = 8 ml/kg, FiO 2 to reach a SaO 2 target of >90%, PEEP = 10 cmH 2 O if PaO 2 /FiO 2 > 300 and 12 cmH 2 O if PaO 2 /FiO 2 < 300, and respiratory rate to obtain a PaCO 2 of 35-45 mmHg. Before as well as 12 and 24 hours after peritonitis induction we measured the PaO 2 /FiO 2 ratio, the total compliance of the respiratory system (C), calculated as VT/(P plateau -PEEP) and inspiratory airway resistance (R i ) calculated as (P max -P plateau ) / mean inspiratory flow. Data are mean [range]. Results For data see Table 1. During the course of the 24-hour study period, six of 10 animals developed gas exchange deteriorations consistent w...