Feasibility and Safety of Radiofrequency Ablation Guided by Bronchoscopic Transparenchymal Nodule Access in Canines.

BACKGROUND: The treatment of pulmonary malignancies remains a challenge. The efficacy and safety of bronchoscopic radiofrequency ablation (RFA) for the treatment of lung cancer are not well elucidated. OBJECTIVE: This study aimed to evaluate the feasibility and safety of RFA guided by bronchoscopic transparenchymal nodule access (BTPNA) in vivo. METHODS: In an attempt to determine the parameters of RFA, we first performed RFA in conjunction with automatic saline microperfusion in the lung in vitro with various ablation energy (10, 15, 20, 25, and 30 W) and ablation times (3, 5, 8, and 10 min). The correlation between ablated area and RFA parameter was recorded and analyzed. Further, we conducted a canine study with RFA by BTPNA in vivo, observing the ablation effect and morphological changes in the lung assessed by chest CT and histopathologic examination at various follow-up time points (1 day, n = 3; 30 days, n = 4; 90 days, n = 4). The related complications were also observed and recorded. RESULTS: More ablation energy, but not ablation time, induced a greater range of ablation area in the lung. Ablation energy applied with 15 W for 3 min served as the appropriate setting for pulmonary lesions ≤1 cm. RFA guided by BTPNA was performed in 11 canines with 100% success rate. Inflammation, congestion, and coagulation necrosis were observed after ablation, which could be repaired within 7 days; subsequently, granulation and fibrotic scar tissue developed after 30 days. No procedure-related complication occurred during the operation or in the follow-up periods. CONCLUSION: The novel RFA system and catheter in conjunction with automatic saline microperfusion present a safe and feasible modality in pulmonary parenchyma. RFA guided by BTPNA appears to be well established with an acceptable tolerance; it might further provide therapeutic benefit in pulmonary malignancies.

Effect of Nitrogen Flow Ratio on Composition, Microstructure, and Mechanical Properties of Cr-B-O-N Films Deposited by Pulsed Direct Current Magnetron Sputtering.

Nano-crystalline CrB2 and Cr-B-O-N films with various nitrogen flow ratios were deposited using a pulsed direct current (PDC) magnetron sputtering technique. By means of electron probe micro-analysis, X-ray diffraction (XRD), X-ray photoelectron spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy (HRTEM), and atomic force microscopy, the influences of the nitrogen flow ratio on the phase constituents and microstructures of CrB2/Cr-B-O-N films were systematically investigated. Mechanical properties including the hardness and elastic modulus were explored by a nano-indentation tester. On increasing the nitrogen flow ratio, the N and O contents in films increased linearly and tended to become saturated, whereas the Cr and B contents decreased. With an increasing nitrogen flow ratio, the microstructure changed from a dense columnar structure to a bulky columnar structure, and then to a fine and stacked dense structure. Meanwhile, the deposition rate also changed with increasing nitrogen flow ratio, owing to the changes in structure. Crystalline phases were observed by the XRD and HRTEM analyses, consisting of several nanometer-size crystallites embedded in an amorphous matrix. The dramatically decreased hardness was attributed to the large fractional volume of the softer amorphous phase BN in films.

Anti-asthma effects of synthetic salidroside through regulation of Th1/Th2 balance.

AIM: The aim of the study was to investigate the effect and mechanism of action of synthetic salidroside in an ovalbumin (OVA)-induced asthma model in mice. METHOD: BALB/c mice were sensitized with an intraperitoneal injection of ovalbumin (OVA) to induce a mouse model of asthma in paracmasis. The mice were treated with dexamethasone as the positive control. At the end of the study, respiratory reactivity was detected, the numbers of various kinds of white blood cells in the bronchoalveolar lavage fluid (BALF) were counted, and the levels of IL-4 and INF-γ in BALF were determined. Quantitative PCR was used to detect the mRNA contents of IL-4 and INF-γ in lung tissue. Histologic examination was performed to observe inflammatory cellular infiltration. RESULTS: Salidroside treatment virtually eliminated airway hyper-reactivity, markedly reduced the eosinophil percent, obviously reduced the levels of IL-4 and raised INF-γ in the bronchoalveolar lavage fluid (BALF) compared with the sham-treated group. Quantitative PCR on the mRNA content of IL-4 and INF-γ provided confirmation. Lung histologic observations showed that salidroside reduced inflammation and edema. These effects were equivalent to the effects of dexamethasone. CONCLUSION: Synthetic salidroside exhibits an anti-asthma effect which is related to the regulation of Th1/Th2 balance. This provides a new possibility for treatment of allergic asthma.