Objective To investigate the changes of stem cell factor（SCF） level in serum of asthma patients before and after acute exacerbation.Methods The serum SCF was detected in 30 asthma patients respectively in the onset period and catabasis by ELISA.The SCF levels were also determined in 20 normal subjects as control.Results the content of serum SCF of the asthma patients during the acute attack was increased significantly than normal subjects [（156.8±82.6）pmol/L vs （61.5±15.4）pmol/L，Plt;0.001]，and decreased significantly in remission [（66.2±15.8）pmol/L，Plt;0.001].Conclusions SCF may participate in the pathogenesis of asthma.
【Abstract】 Objective To investigate the effects of respiratory syncytial virus ( RSV) infection on the dynamic changes of airway hyperresponsiveness ( AHR) in ovalbumin ( OVA) -induced asthma in mice.Methods 60 BALB/c female mice were randomly divided into PBS control group ( A group, n = 6) , OVA group, OVA/RSV group, dexamethasone group ( D group, n =6) . Kinetics of AHR of OVA group mice was carried out on day 21, 25, 29 and 33 ( B1, B2, B3, B4 groups, n =6) , and the same with the OVA /RSV group( C1, C2, C3, C4 groups, n = 6 ) . The mouse asthma model was established by OVA-sensitization of intraperitoneal injection and repeated inhalation of OVA while the mice in OVA/RSV group were treated with combined intranasal inoculation with RSV ( 1. 0 ×106 pfu/mL in 50 μL) . Airway resistance of expiringphase ( RL ) and compliance of throax and lung ( CTL ) with different doses of acetylcholine ( Ach) were measured. Lung tissue sections were stained with hematoxylin and eosin ( HE) and periodic acid-Schiff ( PAS) for general morphology. Results Compared with B1 group, RL increased and CTL decreased in C1 group when Ach dose is above 5 g/L ( P lt; 0. 05, respectively) , and the effects prolonged ( 6 d, 10 d after challenge with OVA, respectively) much more than B1 group ( 2 d after challenge with OVA) . Compared with C1 group, RL decreased and CTL increased in D group and the infiltration of inflammatory cells was obviously alleviated in C1 group after treatment with dexamethasone. Conclusions Airway hyperresponsiveness increases obviously in OVA-sensitized and RSV-infected mice. The prolonged increase inRL and decrease in CTL ( 6 d, 10 d, respectively) may imply that RSV infection aggravates airway inflammation. The small airway inflammation may play a critical role in the persistence of airway hyperresponsiveness.
0bjective To evaluate the efficacy of FEV6 and FEV1／FEV6 as surrogates for FVC and FEV1／FVC in the spirometric diagnosis of airway obstruction，and to determine the fixed cut-off point of FEV1／FEV6 which can be used as an alternative for FEV1／FVC lt; 70％.Methods Spirometry measurements were perform ed in 128 participants．FEV1，FEV6，FVC，FEV1％pred，FVC％pred，FEV1／FVC and FEV1／FEV6 were measured and analyzed.FEV1／FVClt;70％ was used as the“gold standard”。Severity of obstruction was based on FEV ％ pred．From ROC curve analysis，the FEV1／FEV6 ratio，which corresponded to optimal combination of sensitivity and specificity，was determined．Correlation between FEV1／FVC and FEV1／FEV6 was studied．Results Of 128 participants，there were 65(51％)with FEV1／FVC ≥70％ ．Of the 63 participants with FEV1／FVC lt;70％ ，there were 5 with FEV1／FEV6 between 70.09％ to 71％。There was no significant difference between the mean value of FVC and that of FEV ．Lifear correlation was revealed between FEV1／FVC and FEV1／FEV6 with the value close to 1(r=0.9979，Plt;0.0001)．From ROC curve analysis，the FEV1／FEV6lt;71.14％ was the best cut-off point coresponding to FEV1／FVC lt;70％ ．Conclusion These results suggest that FEV1／FEV6 is a valid alternative to FEV1／FVC for spirometric diagnosis of airw ay obstruction．There is a b corelation between FEV1／FEV6 and FEV1／FVC．