Library

Notes: 1. Albino Wistar rats were raised in a normobaric hypoxic environment (10% O2 in N2). Two generations of hypoxic rats were observed for changes in their haemoglobin-oxygen (Hb-O2) dissociation curves (ODC), 2,3-diphosphoglycerate (2,3-DPG), haemoglobin (Hb), and Hill coefficients at P50 (n50). The first generation were called (H1) and the second generation (H2). The control group (N) had a normoxic environment.2. Thirty-five rats (13 N rats, 12 H1 rats and 10 H2 rats) were used. The 2,3-DPG was significantly higher in both hypoxic groups when compared with N rats (2.02 ± 0.51 mmol/L) but 2,3-DPG of H2 rats was significantly lower than that of H1 rats (H1 = 3.48±0.58 mmol/L and H2 = 2.76±0.54 mmol/L). The haemoglobin values were N = 2.00±0.26, H1 = 2.65±0.32and H2 = 2.36±0.30 mmol/L, respectively.3. We observed considerable differences in Hb-O2 affinity between the three groups of rats. In standard conditions (pH = 7.400; pCO2= 40 mmHg at 37°C) the H1 rats showed a significantly decreased Hb-O2 affinity (P50, st= 37.0 ± 1.3 mmHg) when compared with both H2 and N rats; the H2 rats showed a significantly increased Hb-02 affinity (P50, st 1 31.1 ± 1.5 mmHg) when compared with controls N (P50, st= 34.7±2.1 mmHg). There were no significant differences in n50 values: N = 2.88 ± 0.44; H1 = 2.88 ± 0.77; and H2 = 2.94 ± 0.67.4. Therefore, the H1 rats’ ODC was located well to the right of that of N rats; and the H2 rats had an ODC located to the left when compared with both HI and N rats. It is likely that in H2 rats the adaptive processes to the new environment are more advanced; therefore, the magnitude of the compensatory mechanisms required to maintain a sufficient tissue oxygenation may be reduced.

Notes: 1. In our study we followed the growth rate and the haematologic changes occurring in albino rats of Wistar strain when living in a hypoxic environment. Two generations of hypoxic rats were observed for changes in their erythrocytes (RBC), haematocrit (Hct) and haemoglobin (Hb): the first generation (H1) and the second generation (H2). A few hours after birth, the H1 rats were placed and raised in a normobaric hypoxic environment (10% O2 in N2). The H2 rats were born and raised in the environment previously described. The control group had a normoxic environment. The H1 and H2 rats had inferior growth rates in respect to their controls, but H2 were found to have a larger growth rate than the H1 group. The RBC, Hct and Hb had values significantly greater for both H1 and H2 when compared with their controls. However, we did find that the values of H2 were significantly lower than H1. We believe that these results are in relation to the degree of development of the adaptive processes to the hypoxic environment of the H2 rats.

Notes: Background Corticosteroids are considered to be particularly effective in reducing nasal congestion and are therefore recommended as first-line treatment in allergic rhinitis patients with moderate to severe and/or persistent symptoms.Objective We compared the clinical efficacy of fluticasone propionate aqueous nasal spray (FPANS) 200 μg given once daily, administered in mono-therapy or combined therapy with a H1 receptor antagonist (cetirizine, CTZ) or with a leukotriene antagonist (montelukast, MSK), and the combined therapy of CTZ plus MSK in the treatment of patients affected by allergic rhinitis to Parietaria during natural pollen exposure. In addition, we examined the effect of the treatment on eosinophil counts and eosinophil cationic protein (ECP) in nasal lavage performed at beginning of season, during season and at the end of the season.Methods One hundred patients aged 12–50 years (mean±SD 31.8±9.6) with a history of moderate to severe Parietaria pollen-induced seasonal allergic rhinitis were selected. A randomized, double-blind, double dummy, placebo (PLA)-controlled, parallel-group study design was used. Patients were treated FPANS 200 μg once daily (n=20) or with FPANS 200 μg once daily, plus CTZ (10 mg) in the morning (n=20), or with FPANS 200 μg once daily, plus MSK (10 mg) in the evening (n=20) or with CTZ (10 mg) in the morning plus MSK in the evening (n=20) or matched PLA (n=20). Assessment of efficacy was based on scores of daily nasal symptoms and on eosinophil counts and ECP in nasal lavage.Results All treatments showed significant differences (P〈0.001) compared with PLA in terms of total symptom, rhinorrhea, sneezing and nasal itching scores. Concerning nasal congestion on waking and daily only the groups treated with FPANS in mono-therapy or in combined therapy showed significant differences compared with PLA. Comparing the group treated with FPANS alone and the groups treated with FPANS plus CTZ, we found significant differences for total symptom score (P=0.04) and for nasal itching (P=0.003). The comparison between FPANS plus CTZ and FPANS plus MSK showed significant difference for nasal itching (P=0.003). Finally, there were significant differences between the group treated with FPANS and the group treated with CTZ plus MSK for total symptom score (P=0.009), for nasal congestion on waking (P〈0.001) and nasal congestion daily (P〈0.001). Also the comparisons between the group treated with FPANS plus CTZ and the group treated with CTZ plus MSK demonstrated significant differences (P〈0.001) for total symptom, for nasal congestion on waking and for nasal congestion on daily, for rhinorrhea (P=0.04) and for nasal itching (P=0.003) scores. Concerning the comparison between the group treated with FPANS plus MSK and the group treated with CTZ plus MSK we found significant differences for total symptom score (P=0.005), for nasal congestion on waking (P〈0.001) and for nasal congestion on daily (P〈0.001). No other differences were observed between the groups. Concerning blood eosinophil counts, significant differences were found between the treatments with FPANS in mono-therapy or in combined therapy with PLA group during and at the end of the season (P=0.0003 and P〈0.0001, respectively). Concerning eosinophils and ECP in nasal lavage, all treatments showed significant differences (P〈0.001) compared with PLA. Besides, there were significant differences (P〈0.001) between the groups treated with FPANS alone or in combined therapy and the group treated with CTZ plus MSK.Conclusion The results of this comparative study demonstrate that FPANS is highly effective for treating patients affected by allergic rhinitis, with efficacy exceeding that of CTZ plus MSK in combined therapy. In addition, the regular combined therapy of FPANS plus CTZ or plus MSK would not seem to offer substantial advantage with respect to FPANS in mono-therapy in patients affected by seasonal allergic rhinitis.

Notes: Background In atopic asthma there is strong evidence of eosinophils playing an active role in pathogencsis. Some investigations demonstrated that eosinophil cationic protein (ECP) serum levels increased in atopic patients with asthma during pollen season.Objective The aim of the study was to evaluate the effects of short-term (1 week) β2-agonist treatment on lung function and eosinophil activity in asthmatic patients. Methods We used an open, randomized, cross-over design to compare the effects of salbutamol (200μg q.i.d.) and salmeterol (50μg b.i.d.) on peak expiratory flow rate (PEFR), blood eosinophil count and serum levels of ECP as a measure of eosinophil activity in 20 mild atopic asthmatics.Results Morning and evening PEFR values were both significantly higher during salmeterol treatment than during the salbutamol period. Conversely, both morning and evening daily asthma symptom scores were significantly lower during salmeterol treatment compared with those recorded during the salbutamol period. The mean basal eosinophil blood count on salmeterol treatment (601 ± 189mm3) was not higher than the mean count on salbutamol treatment (612 ± 204 mm3). After both treatments the mean eosinophil blood counts were unchanged (619 ± 189mm3 and 576 ±212 mm3, respectively). No significant differences in blood eosinophil counts were observed between or within treatments at any time. No significant difference was observed in baseline mean ECP serum concentration (43.8 ± 263 μg L on salmeterol treatment and 41.7 ± 29.8 μg L on salbutamol treatment, respectively). After salmeterol treatment the mean ECP serum concentration had fallen significantly to 20.9± 18.6μg/L (P 〈 0.01), whereas after salbutamol treatment it was unchanged (42.0 ± 25.1 μg /L). Salmeterol treatment produced a decrease in ECP serum levels without any changes in blood eosinophil count.Conclusion This study demonstrates that salmeterol affords a significant improvement in asthma control during the pollen season, measured by both subjective and objective parameters, compared with salbutamol. This greater efficacy may be related to inhibition of eosinophil degranulation during the pollen season.

Notes: Background Inflammatory cells are increased in the airways of endurance athletes, but their role in causing exercise-induced respiratory symptoms and bronchoconstriction, or their possible long-term consequences, are uncertain.Aim To put the results of athlete studies in perspective, by analysing the pathogenesis of airway cell changes and their impact on respiratory function.Results Athletes of different endurance sports at rest showed increased airway neutrophils. Elite swimmers and skiers also showed large increases in airway eosinophils and lymphocytes, possibly related to chronic, exercise-related exposure to irritants or cold and dry air, respectively. Post-exercise studies reported variable responses of airway cells to exercise, but found no evidence of inflammatory cell activation in the airways, at variance with exercise-induced neutrophil activation in peripheral blood. The increase in airway inflammatory cells in athletes can result from hyperventilation-induced increase in airway osmolarity stimulating bronchial epithelial cells to release chemotactic factors. Hyperosmolarity may also inhibit activation of inflammatory cells by causing shedding of adhesion molecules, possibly explaining why airway inflammation appears ‘frustrated’ in athletes. Data on exhaled nitric oxide are few and variable, not allowing conclusions about its usefulness as a marker of airway inflammation in athletes, or its role in modulating bronchial responsiveness.Conclusions The acute and long-term effects of exercise on airway cells need further study. Airway inflammatory cells are increased but not activated in athletes, both at rest and after exercise, and airway inflammation appears to regress in athletes quitting competitions. Altogether, these findings do not clearly indicate that habitual intense exercise may be detrimental for respiratory health. Rather, airway changes may represent chronic adaptive responses to exercise hyperventilation. An improved understanding of the effects of exercise on the airways will likely have a clinical impact on sports medicine, and on the current approach to exercise-based rehabilitation in respiratory disease.

Notes: Background Initial attempts to evaluate the association between allergic rhinitis and nonspecific bronchial responsiveness has produced conflicting results. In fact, some studies showed a strong correlation and other failed to find an association. However, little is known about the effect of natural specific allergen exposure on the bronchial reactivity of mono-sensitive patients with rhinitis in the southern Mediterranean area, in relation to skin reactivity to allergens, total serum IgE levels and blood eosinophiis.Objectives The significance of the association between allergic rhinitis, and abnormal airway responsiveness with regard to the pathogenesis of asthma is unclear. For this reason, we have studied non-specific bronchiai hyperreactivity. in patients with seasonal allergic rhinitis, with reference to the responsible allergen. The aim of the study was to correlate the responsiveness to bronchoprovocation with methacholine in subjects a with allergic rhinitis during and out of the pollen season with total serum IgE and blood eosinophils.Methods Fourty-nine non-smoking patients with clinical diagnosis of allergic rhinitis and mono-sensitive skinprick tests to pollen allergens were enrolled in the study. Twenty patients suffered from seasonal rhinitis to Parietaria pollen. 15 patients to Gramineae pollen and 14 patients to Olea pollen. In all patients lung function measurements (assessed as response to methacholine). tolal serum IgE and blood eosinophii counts were measured during and out of the pollen season.Results During pollen season. 16 out of 49 rhinitis patients demonstrated values of bronchial responsiveness measured as response to inhaled metbacholine in the asthmatic range whereas out of the pollen season only eight patients were in the asthmatic range. By analysing the results with reference to the responsible allergen, during the pollen season 5 out of 16 patients were Parietaria -sensitive and out of the pollen season seven out of eight patients. Finally, in Parietaria -sensitive rhinitis bronchial responsiveness signifi-cantly correlated, during and out of the pollen season, with total serum IgE and with blood eosinophil counts.Conclusions Our results are consistent with the hypothesis that Parietaria is more important than Olea and Gramineae as a risk for developing non- specific bronchial hyperresponsiveness. On the whole, present observations provide further evidence that there is an interrelationship of allergen kind, total serum IgE. eosinophil and bronchial hyperressponsiveness suggesting that they may play a role in the development of bronchial asthma in rhinitis patients.