In vitro study of safety and co-efficiency of the transbronchial coagulation techniques / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The usual transbronchial coagulation techniques include microwave, argon plasma coagulation (APC), electrocautery and cryotherapy. However, there are serious clinical problems in the safety of each. By analyzing the experimental data and clinical observations, we observed the variable effects of different coagulation techniques via bronchofibroscopy, to look for an optimal interventional management of luminal bronchus diseases, and evaluate the safety and the equivalent point.</p><p><b>METHODS</b>Four kinds of coagulation techniques under bronchoscopy were performed on the fresh bronchus of healthy sheep, and the pathologic changes in all groups were observed under the microscope. The different treatment parameters were as follows: microwave 60 W×1 second, 3 seconds, 5 seconds and 40 W×1 second, 3 seconds, 5 seconds; APC 40 W×1 second, 3 seconds, 5 seconds; electrocautery 40 W×1 second, 3 seconds, 5 seconds; cryotherapy 100 Ω×60 seconds, 120 seconds.</p><p><b>RESULTS</b>After treatment, ovine bronchial mucosa in all groups showed pathologic changes such as local necrosis and amotio of the mucosa lining epithelium, local submucosa coagulative necrosis or tissue defects, while inflammation in the surrounding tissue was not obvious. Under the same output power and action time, different methods had different outcomes. The damage by APC was the most superficial, microwave was the second, and electrocautery caused the worst damage. The study also found that effects of electrocautery at 40 W×3 seconds, microwave at 40 W×5 seconds or 60 W×3 seconds, APC at 40 W×5 seconds and cryotherapy at 100 Ω×120 seconds were the equivalent point conditions. The appearance included mucosa absence, partial submucosa absence, and collagen fiber coagulation in treatment areas.</p><p><b>CONCLUSIONS</b>Each coagulation technique has its own characteristic. It is very important to choose the appropriate power and action time of the suitable method according to the therapy requirement.</p>

Swyer-James syndrome with peculiar course and ipsilateral pulmonary vein defect.

Swyer-James syndrome (SJS) is a rare disease probably resulting from bronchiolitis obliterans. The radiological findings of this entity are characterized by hyperlucent appearance of one or more lobes of a unilateral lung, decreased lung volume, diminished ipsilateral hilar shadow and hardly visible arterial structure on chest radiography. We report a 50-year-old patient, who had unilateral right lower lung hyperlucency on chest radiography. However, the patient reported a history of pulmonary atelectasis of lobus centralis dexter in the course and the corresponding affliction of ipsilateral pulmonary vein, that rendered the diagnosis more complicated. The radiological and pathological features of this syndrome, as well as differential diagnosis were also discussed.

Microwave induces apoptosis in A549 human lung carcinoma cell line / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Microwaves have other biological effects on cancer as well besides killing tumor cells by coagulation. Some studies showed that microwaves may induce apoptosis in some tumor cells. The apoptotic effect of microwaves may help in clinic to remove residual malignant cells nearby the primary lesion and avoid relapse subsequently. However, there is little evidence on this subject from lung cancer. We studied the effect of microwaves on inducing apoptosis in the human lung carcinoma cell line A549 cells, aiming to identify its effect on apoptosis.</p><p><b>METHODS</b>A549 cells were radiated by various intensities and durations of microwaves. Apoptosis induction in A549 cells was analyzed by morphological observations, tetrazolium blue color method (MTT) assays, flow cytometry, immunohistochemistry, and image analyses.</p><p><b>RESULTS</b>Morphological changes in A549 cells, including cell shrinking and nuclear pyknosis, were observed after microwave radiation. Microwaves significantly inhibited metabolic activities and induced apoptosis in A549 cells. The results of the MTT assay showed a significant decrease of cell activities in all the radiation groups compared with the normal control (P < 0.01). The low point of cell activities often appeared at 6 - 12 hours after radiation. Apoptosis was also confirmed by flow cytometry. The early stage apoptotic rate reached 6.10% - 17.98% and the advanced stage apoptotic rate + necrosis rate reached 8.04% - 44.06% at 6 hours after microwave irradiation, in contrast to 2.32% and 4.10% in the respective control groups. Down-regulation of Bcl-2 expression and up-regulation of p53 expression were observed by immunohistochemistry after radiation. In most treated groups, the down-regulation of Bcl-2 expression reached its lowest level at 3 - 6 hours after radiation (integrated optical density (IOD)-6 hours: 2.13 ± 0.08 - 5.14 ± 0.13 vs. control: 5.79 ± 0.10, P < 0.01) and the up-regulation of P53 expression peaked at about 3 hours (IOD-3 hours: 2.61 ± 0.13 - 8.07 ± 0.11 vs. control: 1.29 ± 0.07, P < 0.01). Cell damage, apoptosis, and protein expression levels in the samples differed depending on the radiation intensity and duration.</p><p><b>CONCLUSIONS</b>Microwaves can promote apoptosis in A549 cells. The effect depends on the duration and dosage of microwave radiation. Bcl-2 and p53 proteins may be involved in the apoptotic process of A549 cells induced by microwaves.</p>

Establishment of rat chronic obstructive pulmonary disease model: A comparison between exposure to cigarette smoke alone and in combination with intra-tracheal injection of lipopolysaccharide / 第二军医大学学报

Objective To compare the efficacies of exposure to cigarette smoke alone and in combination with intra-tracheal injection of lipopolysaccharide in establishing rat models of chronic obstructive pulmonary disease (COPD). Methods A total of 24 8-week-old healthy Wistar rats were randomly divided into 2 model groups and a control group (Group C). The rat COPD models were established by two ways; intratracheal injection of lipopolysaccharide (LPS) twice + exposure to cigarette smoke for 1 month (Group A), and cigarette smoke inhalation for 80 days only (Group B). The pathologic characteristics of animal models, including the mean lining interval (MLI) and the mean alveoli number(MAN), were determined. The total and different white blood cell counts in bronchoalveolar lavage fluid(BALF) and blood samples were determined. Results The rats in the two model groups presented with cough or breathlessness periodically, and the white blood cell counts and neutrophil counts in the peripheral blood and BALF were significantly higher than those in the control group (P<0.01). H-E staining showed that the lung tissues of rats in Group A and B had typical pathological features of COPD and emphysema. MLI were significantly higher and MAN were significantly lower in Group A and B than those in group C (both P<0.01), but there was no statistical difference between the two model groups. Group A had more severe inflammatory response in the bronchial and lung tissues than Group B. And Group B was characterized by alveolar overdistension. Conclusion Both the two methods can successfully establish rat COPD model, with its pathophysiological changes similar to those of human COPD, with intra-tracheal injection of lipopolysaccharide being more consistent to the natural development of disease.