BACKGROUNDTo study the biological effects of multi-electrode radiofrequency ablation on pulmonary tissues of rabbits.

METHODSUnder the guidance of computer tomograph, electrodes were inserted into right lungs of New Zealand white rabbits and radiofrequency was performed. The biological effects were observed through CT image and microscopy.

RESULTSCoagulative necrosis was found immediately in ablation area after the procedure. On the 7th postradiofrequency ablation day, fibrous tissues appeared in the necrotic lesions. On the 30th postradiofrequency ablation day, bronchial and alveolar epithelium began to proliferate. Within 60 to 90 days after treatments, the necrotic lesions were almost replaced by normal pulmonary tissues. In group with electrodes into the right hilum, time for treating and initial impedance were significantly different from those with electrodes into the peripheral sites of the right-lower lobes (P < 0.01, P < 0.01).

CONCLUSIONSMulti-electrode radiofrequency ablation can be safely and effectivly performed in pulmonary tissue and cause coagulative necrosis within a certain extent.

OBJECTIVETo investigate the effect of trans-acting factor(s) on rat glutathione S-transferase P1 gene (rGSTP1) transcription regulation in tumor cells.

METHODSThe binding of trans-acting factor(s) to two enhancers of the rGSTP1 gene, glutathione S-transferase P enhancer I (GPEI) and glutathione S-transferase P enhancer II-1 (GPE II-1), was identified by an electrophoretic mobility shift assay (EMSA). The molecular weight of trans-acting factor was measured in a UV cross-linking experiment.

RESULTSTrans-acting factor interacting with the core sequence of GPEI (cGPEI) were found in human cervical adenocarcinoma cell line (HeLa) and rat hepatoma cell line (CBRH7919). These proteins were not expressed in normal rat liver. Although specific binding proteins that bound to GPE II-1 were detected in all three cell types, a 64 kDa binding protein that exists in HeLa and CBRH7919 cells was absent in normal rat liver.

CONCLUSIONcGPEI, GPEII specific binding proteins expressed in HeLa and CBRH7919 cells may play an important role in the high transcriptional level of the rGSTP1 gene in tumor cells.

Animals ; Carrier Proteins ; metabolism ; Enhancer Elements, Genetic ; physiology ; Gene Expression Regulation, Enzymologic ; Glutathione S-Transferase pi ; Glutathione Transferase ; genetics ; Isoenzymes ; genetics ; Nuclear Proteins ; metabolism ; Rats ; Transcription, Genetic