The method that we have previously reported for sputum induction involves collecting the entire expectorate produced over a 20 min inhalation of 3% saline aerosol. This method presents the potential disadvantage of a considerable and variable salivary contribution to the induced sputum sample. In this study, we examined whether separate collection of saliva and sputum represents a better method for collecting induced sputum during sputum induction.In 11 stable asthmatics, we compared the volume, total and differential cell counts, and eosinophil cationic protein (ECP) levels in four induced sputum samples, two performed using our previous method (Method A) and two using another method (Method B) in which subjects spit saliva into one container before coughing sputum into another.We found that the volume of sputum obtained with Method B was lower than that obtained with Method A (6.16±0.61 vs 20.1±2.7 mL; p=0.003), as was the percentage of squamous cells (34±4 vs 47±6; p=0.023). In addition, the ECP levels in samples collected by Method B were higher (261±42 vs 145±26 ng·mL -1 ; p=0.01). The differential counts of nonsquamous cells were similar except for the percentage of neutrophils, which was lower in Method B (37±4 vs 50±5%; p=0.019). The repeatability of measurements of eosinophil percentages and of ECP levels was similar for the two methods.We conclude that separate collection of saliva and sputum yields induced sputum samples with reduced amounts of saliva and is, therefore, a better method for collecting induced sputum. Eur Respir J., 1996Respir J., , 9, 2448Respir J., -2453 Sputum induction has recently been shown to be an effective and noninvasive method for obtaining airway secretions for analysis of their cellular and biochemical constituents [1,2]. Analysis of induced sputum samples from asthmatic subjects has revealed higher than normal eosinophil percentages and higher than normal eosinophil cationic protein (ECP) levels [1,2], data that is qualitatively similar to that obtained from analysis of bronchoalveolar lavage (BAL) [3]. In addition, analysis of induced sputum from asthmatic subjects has documented the expected changes in inflammatory markers accompanying allergen challenge [4,5], isocyanate challenge [6] and prednisone therapy [7].At the present time, there is a lack of consensus on the optimal techniques for obtaining, processing and analysing induced sputum samples. The method that we have previously reported for sputum induction involves collecting and analysing the entire expectorate, including saliva and sputum, produced over a 20 min inhalation of 3% saline aerosol. This method has the advantage of relative simplicity and has been shown to be valid [2,3,5,7], but presents the potential disadvantage of a considerable and variable salivary contribution to the induced sputum sample. Saliva has at least two effects on induced sputum: it contributes cells and chemicals from the oropharynx and it dilutes the concentrations of subglottic cells and chemicals. The cells in saliva ...

The dose dependency of the effects of inhaled corticosteroids on markers of asthmatic airway inflammation have not been well studied. There is a need to study the dose/response effects on this inflammation.In order to determine the dose/response effects of fluticasone propionate (FP), 24 asthmatic subjects were randomized to low-(100 mg . day -1 ) or high-dose (1,000 mg . day -1 ) FP for six weeks followed by placebo for 3 weeks.During treatment, the median increase in forced expiratory volume in one second (FEV1) was 12% in the high-dose group (p<0.05) and 10% in the low-dose group (p<0.05) (p>0.05 between groups); the median decrease in the percentage of sputum eosinophils was 93% in the high-dose group (p<0.05) and 46% in the low-dose group (p<0.05) (p>0.05 between groups). Symptoms, salbutamol use, morning peak flow, provocative concentration of methacholine causing a 20% fall in FEV1 (PC20), sputum eosinophil cationic protein concentration and tryptase activity improved significantly in both groups (p<0.05), but only the improvement in salbutamol use was greater in the highdose group (p<0.05). During the run-out, the improvements in FEV1 and PC20 were rapidly reversed in both groups, but the improvements in peak flow and tryptase activity persisted; the improvement in sputum eosinophil concentration persisted only in the high-dose group (p<0.05).It was concluded that dose/response effects for FP are not easily demonstrable because low-dose FP is quite effective. For most outcomes, the effects of high-and lowdose FP are relatively short-lived after treatment is stopped. This finding raises questions about the extent to which inhaled corticosteroids are disease-modifying in asthma. Eur Respir J 2000; 15: 11±18.

Recombinant Escherichia coli strain GCSC 6576, harboring a high-copy-number plasmid containing the Ralstonia eutropha genes for polyhydroxyalkanoate (PHA) synthesis and the E. coli ftsZ gene, was employed to produce poly-(3-hydroxybutyrate) (PHB) from whey, pH-stat fed-batch fermentation, using whey powder as the nutrient feed, produced cellular dry weight and PHB concentrations of 109 g l-1 and 50 g l-1 respectively in 47 h. When concentrated whey solution containing 210 g l-1 lactose was used as the nutrient feed, cellular dry weight and PHB concentrations of 87 g l-1 and 69 g l-1 respectively could be obtained in 49 h by pH-stat fed-batch culture. The PHB content was as high as 80% of the cellular dry weight. These results suggest that cost-effective production of PHB is possible by fed-batch culture of recombinant E. coli using concentrated whey solution as a substrate.

To determine if RANTES expression is unregulated in the airways of asthmatic subjects, we performed bronchial mucosal biopsies and airway lavage in seven atopic asthmatic subjects and eight healthy subjects. Immunohistochemistry was used to reveal RANTES protein expression in the airway biopsies. An ELISA was used to quantitate RANTES in lavage. In three subjects in each group, we also used in situ hybridization to reveal mRNA for RANTES in airway biopsies. We found that the mean (+/- SD) percent expression for RANTES in the epithelium and submucosa was 26 +/- 9% and 26 +/- 10% in the asthmatic and healthy tissue samples, respectively. RANTES mRNA was demonstrable in the bronchial mucosa of both healthy and asthmatic subjects, predominantly in the epithelial cells but also in the submucosa. We also found that there was no significant difference in the median RANTES concentrations between the groups (healthy: 2.9 pg/ml [range: 0.0 to 28.7 pg/ml]; asthma: 1.8 pg/ml [range: 0.0 to 82.1 pg/ml], p > 0.05) despite a trend for higher concentrations of eosinophil cationic protein (ECP) in the asthmatic group (p = 0.08). In summary, this study confirms that cells in airway mucosal tissue produce RANTES but that the level of production in mild stable asthma is not different from that of healthy control subjects.