Yong Chul Lee

Serum levels of interleukins (IL)-4, IL-5, IL-13, and interferon-γ in acute asthma

T-cell activation and alteration of cytokine levels are involved in the pathogenesis of bronchial asthma. However, the profile of circulating T-lymphocyte subsets and related cytokines during acute asthmatic attacks is still unclear. We hypothesized that serum levels of interleukin (IL)-4, IL-5, and IL-13 would be increased, whereas IFN-γ would be decreased in acute asthma. The subjects enrolled in this study included 58 acute asthmatics, 22 asymptomatic asthmatics, and 10 healthy controls. Serum levels of IL-4, IL-5, IL-13, and IFN-γ were measured using a sandwich enzyme-linked immunosorbent assay. We correlated serum levels of IL-4, IL-5, IL-13, and IFN-γ with initial forced expiratory volume in 1 sec (FEV1). Compared with control subjects, acute asthmatics had significantly increased levels of circulating IL-4 (p < 0.001), IL-5 (p < 0.001), and IL-13 (p < 0.001), although the differences were of borderline significance in serum IFN-γ (p = 0.069). There were also significant differences in the circulating levels of IL-4, IL-5, and IL-13 between acute asthmatics and asymptomatic asthmatics. There was no significant association between initial FEV1 and serum levels of IL-4 or IL-13, however, among acute asthmatics, a lower initial FEV1 was associated with higher IL-5 and/or lower IFN-γ levels. Our results suggest that serum levels of IL-4, IL-5, and IL-13 may be elevated in acute asthma, and that higher levels of IL-5 and/or lower levels of IFN-γ are associated with severe airway obstruction.

Radiofrequency Ablation Using a Monopolar Wet Electrode for the Treatment of Inoperable Non-Small Cell Lung Cancer: a Preliminary Report

Objective To assess the technical feasibility and complications of radiofrequency ablation (RFA) using a monopolar wet electrode for the treatment of inoperable non-small cell lung malignancies. Materials and Methods Sixteen patients with a non-small cell lung malignancy underwent RFA under CT guidance. All the patients were non-surgical candidates, with mean maximum tumor diameters ranging from 3 to 6 cm (mean: 4.6 ± 1.1 cm). A single 16-gauge open-perfused electrode with a 2 cm exposed tip was used for the procedure. A 0.9% NaCl saline solution was used as the perfusion liquid with the flow adjusted to 30 mL/h. The radiofrequency energy was applied for 10-40 minutes. The response to RFA was evaluated by performing contrast-enhanced CT immediately after RFA, one month after treatment and then every three months thereafter. Results Technical failure was observed in six (37.5%) of 16 patients: intractable pain (n = 2) and non-stop coughing (n = 4). The mean follow-up interval was 15 ± 8 months (range: 9-31 months). The mean maximum ablated diameter in the technically successful group of patients ranged from 3.5 to 7.5 cm (mean 5.1 ± 1.3 cm). Complete necrosis was attained for eight (80%) of 10 lesions, and partial necrosis was achieved for two lesions. There were two major complications (2/10, 20%) encountered: a hemothorax (n = 1) and a bronchopleural fistula (n = 1). Conclusion Although RFA using a monopolar wet electrode can create a large ablation zone, it is associated with a high rate of technical failure when used to treat inoperable non-small cell lung malignancies.

Radio Frequency Ablation in the Rabbit Lung Using Wet Electrodes: Comparison of Monopolar and Dual Bipolar Electrode Mode

Objective To compare the effect of radio frequency ablation (RFA) on the dimensions of radio frequency coagulation necrosis in a rabbit lung using a wet electrode in monopolar mode with that in dual electrode bipolar mode at different infusion rates (15 mm/hr versus 30 ml/hr) and saline concentrations (0.9% normal versus 5.8% hypertonic saline). Materials and Methods Fifty ablation zones (one ablation zone in each rabbit) were produced in 50 rabbits using one or two 16-guage wet electrodes with a 1-cm active tip. The RFA system used in the monopolar and dual electrode wet bipolar RFA consisted of a 375-kHz generator (Elektrotom HiTT 106, Berchtold, Medizinelektronik, Germany). The power used was 30 watts and the exposure time was 5 minutes. The rabbits were assigned to one of five groups. Group A (n = 10) was infused with 0.9% NaCl used at a rate of 30 ml/hr in a monopolar mode. Groups B (n = 10) and C (n = 10) were infused with 0.9% NaCl at a rate of 15 and 30 ml/hr, respectively in dual electrode bipolar mode; groups D (n = 10) and E (n = 10) were infused with 5.8% NaCl at a rate of 15 and 30 ml/hr, respectively in a dual electrode bipolar mode. The dimensions of the ablation zones in the gross specimens from the groups were compared using one-way analysis of variance by means of the Scheffe test (post-hoc testing). Results The mean largest diameter of the ablation zones was larger in dual electrode bipolar mode (30.9±4.4 mm) than in monopolar mode (22.5±3.5 mm). The mean smallest diameter of the ablation zones was larger in dual electrode bipolar mode (22.3±2.5 mm) than in monopolar mode (19.5±3.5 mm). There were significant differences in the largest and smallest dimension between the monopolar (group A) and dual electrode wet bipolar mode (groups B-E). In dual electrode bipolar mode, the mean largest diameter of the ablation zones was larger at an infusion rate of 15 ml/hr (34.2±4.0 mm) than at 30 ml/hr (27.6±0.1 mm), and the mean smallest diameter of the ablation zones was larger at an infusion rate of 15 ml/hr (27.2±7.5 mm) than at an infusion rate of 30 ml/hr (24±2.9 mm). Conclusion Using a wet electrode, dual electrode bipolar RFA can create a larger ablation zone more efficiently than monopolar RFA.