Parametric data. Descriptive statistics of the 8 HKGs were computed by BestKeeper. The comparisons of gene expression levels and demographic characteristics of the participants between subgroups were performed by using the one-way ANOVA (two tailed) for parametric data, Kruskal-Wallis H test for nonparametric data and Student-Newman-Keuls test for multiple comparisons. All analyses were conducted with SPSS software, version 18.0 (IBM Corp, New York, USA). P,0.05 was considered significant.RNA Extraction and Complementary DNA PreparationTotal RNA was isolated using Trizol (Invitrogen, Carlsbad, California, USA) following the manufacturer’s protocol. RNA integrity was assessed on the basis of demonstration of distinct 28 s and 18 s ribosomal RNA bands following 1 agarose electrophoresis and the 28 S RNA was approximately twice as intense as the 18 S rRNA. Complementary DNA (cDNA) synthesis was carried out using the RevertAidTM first strand cDNA synthesis kit (Fermentas Inc, Burlington, Canada). Template RNA and 1 mL of random hexamer primers (10 mM) in a total volume of 12 mL were incubated for 5 min at 65uC and chilled on ice. After adding 4 mL of 56reaction buffer, 1 mL of RiboLockTM RNase Inhibitor (20 U/mL), 2 mL of dNTP Mix (10 mM), 1 mL of RevertAidTM M-MuLV Reverse Transcriptase (200 U/mL), the incubation step for 5 min at 25uC, followed by reverse transcriptase incubation for 60 min at 42uC, termination of the reaction by heating at 70uC for 5 min, finally cooling to 4uC before storage at 220uC. The cDNA for assays of ACTB, GAPDH, B2M, PPIA and RPLP0 was diluted 1:25 because these genes were highly expressed in pilot studies; while assays of RN28S1, GUSB, RPL13A and PGK1 were performed using cDNA diluted 1:15 because they had relatively low expression levels.Results SubjectsCharacteristics of the three groups of participants are summarized in Table 1. By design, all 3 groups (NDA, n = 1, DA, n = 11, and HC, n = 10) were similar in sex and age distribution. All subjects were non-smokers or former smokers and there were only two former smokers, one in NDA group and the other in NC group. Both of them have quitted at least 10 years and had smoked cigarette 4.5 and 0.5 pack-years, respectively. All medications were discontinued for a minimum of 2 weeks before recruitment. In detail, one BML-275 dihydrochloride patient from the NDA group and two from DA group inhaled inhaled corticosteroid (ICS) + Long-acting b2-agonists (LABA). However, all of them used ICS + LABA for a maximum of 1 month and discontinued at least 4 weeks before blood was drawn. Four patients from the NDA 1407003 group and three from the DA group took theophylline, and one patient from each group took antileukotrienes orally. However, the medications were discontinued at least 2 weeks before the experiment. There were significant differences between subgroups in FEV1 predicted, FEV1/forced vital capacity (FVC) , the proportion having anaphylactic history and total immunoglobulin E (IgE) present in each sample. Age, sex, body mass index (BMI), the proportion of participants who were atopic, number of eosinophils and the proportion of eosinophils did not differ among the three groups. There were no significant differences in demographic characteristics such as PD20FEV1 and asthma severity, etc. between NDA and DA groups (see 1407003 group and three from the DA group took theophylline, and one patient from each group took antileukotrienes orally. However, the medications were discontinued at least 2 weeks before the experiment. There were significant differences between subgroups in FEV1 predicted, FEV1/forced vital capacity (FVC) , the proportion having anaphylactic history and total immunoglobulin E (IgE) present in each sample. Age, sex, body mass index (BMI), the proportion of participants who were atopic, number of eosinophils and the proportion of eosinophils did not differ among the three groups. There were no significant differences in demographic characteristics such as PD20FEV1 and asthma severity, etc. between NDA and DA groups (see 1662274 Table 1 for detail).Real-time Quantitative PCRThe expression analysis for all 9 genes was performed using an FTC 2000 qPCR system (Funglyn Biotech Inc, Scarborough, Canada), PC.
