Comparison of functional parameters of small airways between patients with typical asthma and cough-variant asthma / 南方医科大学学报

<p><b>OBJECTIVE</b>To compare the functional parameters of the small airways and clinical characteristics between patients with typical asthma (TA) and cough-variant asthma (CVA).</p><p><b>METHODS</b>Forty-three newly diagnosed asthmatic patients were enrolled, including 15 with TA and positive bronchial provocation test [TA BPT(+)], 12 with TA and positive bronchial dilation test [TA BDT(+)] and 16 with CVA, and 27 healthy subjects served as the control group. All the subjects were required to complete data acquisition, asthma control test, asthma control test scale, fractional exhaled nitric oxide, airway resistance and pulmonary function tests, BPT or BDT.</p><p><b>RESULTS</b>The interval from onset to a definite diagnosis of TA BDT(+) was longer than that of TA BPT(+), while that of CVA was the shortest (P=0.022). The pulmonary functional parameters of TA BDT (+) was significantly lower than those of the other 3 groups (P<0.05). MMEF, MEF, MEF, and MEFin patients with TA BDT(+), TA BPT(+) and CVA were significantly lower than those in the control group (P<0.01). The resonant frequency, respiratory impedance, resistance at 5 Hz, resistance at 20 Hz, and reactance at 5 Hz were significant higher in patients with TA BDT (+) than in the control subjects, while these parameters showed no significant differences among TA BPT (+), CVA and control groups. The airway resistance in TA BPT(+), CVA, and control groups increased after BPT, and the patients with TA BPT(+) showed greater changes in airway resistance than those in CVA and control groups. In CVA patients, FeNO showed a strong positive correlation with respiratory impedance (r=0.523, P=0.038), resistance at 5 Hz (r=0.542, P=0.030), and resistance at 20 Hz (r=0.524, P=0.037), and the airway responsiveness showed a strong positive correlation with resistance at 20 Hz (Rho=-0.512, P=0.043).</p><p><b>CONCLUSION</b>CVA is the early stage of TA, and CVA, TA BPT(+), and TA BDT(+) may represent different stages of asthma. Uncontrolled, prolonged CVA may evolve into TA BPT (+), whose further progression can cause damages of the pulmonary function and small airway function and leads eventually to TA BDT (+).</p>

Safety and efficacy of a novel plastic stent coated with stone-dissolving agents for the treatment of biliary stones in a porcine model.

BACKGROUND AND STUDY AIM: We previously reported on a plastic stent that was coated with ethylenediaminetetraacetic acid (EDTA) and sodium cholate, which dissolved common bile duct (CBD) stones ex vivo. The aim of this study was to investigate the safety and efficacy of such stents on biliary stones in a live porcine model. METHODS: Stents without coating or with degradable membranes containing 0 % or 50 % EDTA and sodium cholate were inserted together with human CBD stones into the porcine CBD. Serum laboratory variables, histological examinations of the bile duct, and the weight change in stones were compared during and after stent placement for 6 months. RESULTS: A total of 16 pigs were included (5 no coating, 5 0 % coating, 6 50 % coating). Biliary stones showed decreased weight in all groups; however, stones in the group with 50 % coated stents showed a greater reduction in weight compared with the no coating and the 0 % coating groups (269 ±â€Š66 mg vs. 179 ±â€Š51 mg [P = 0.09]; 269 ±â€Š66 mg vs. 156 ±â€Š26 mg [P = 0.01], respectively). CONCLUSIONS: The plastic stent coated with 50 % agent enhanced CBD stone dissolution in vivo and may be a promising tool for patients with difficult biliary stones.

The effect of a novel drug-eluting plastic stent on biliary stone dissolution in an ex vivo bile perfusion model.

BACKGROUND: Temporary plastic stent insertion has been considered a safe and effective bridge therapy for difficult common bile duct (CBD) stones. Infusing chemicals to directly dissolve stones through the bile duct might also be effective. However, there are no studies on the efficacy of the combination of these 2 approaches. OBJECTIVE: To investigate the efficacy of a novel ethylenediaminetetraacetic acid (EDTA) and sodium cholate-eluting plastic stent on biliary stones. DESIGN: Ex vivo model by using different doses of active ingredient. SETTING AND INTERVENTIONS: An ex vivo bile duct model perfused with porcine bile was created. Stents coated with degradable membranes containing various concentrations of EDTA and sodium cholate were placed in the model with CBD stones. MAIN OUTCOME MEASUREMENTS: The change in the weight of stents and stones was measured every week during perfusion until the coated membranes were completely biodegraded. RESULTS: The time that the stents required to be fully degraded and the efficiency of stone dissolution were positively correlated with the percentage of EDTA and sodium cholate in the stent membrane. However, the 50% EDTA and sodium cholate stents achieved the greatest percentage of stone weight loss when the drugs were completely released. LIMITATIONS: Ex vivo study. CONCLUSIONS: The EDTA and sodium cholate-eluting plastic stent effectively dissolved CBD stones and has prospect in the therapy for patients with difficult CBD stones.