Objective To investigate the expression of ionic channels of the rat bone marrow mesenchymal stem cells(BMSCs) and provide the basis for the change of ionic channels in the process of differentiation of stem cells.Methods The full marrow from Wistar rats was isolated by Percoll centrifugation and passaged repeatedly.The membrane currents of BMSCs were recorded with the whole-cell patch-clamp technique.The current amplitude of pathway,peal value and time course of activation and deactivation,selectivity of ions pathway,I-V curve were recorded.The currents were identified and analyzed by using various channel blockers.Results The cells began to stick in 24 h and arranged in whirlpool shape after passenger culture.They were positive for CD71,CD44,and negative for CD34,CD45 by flow cytometry,which improved that the cultured cells were BMSCs.The functional ion channels were characterized in cultured rat BMSCs with whole-cell patch clamp and reverse transcription polymerase chain reaction(RT-PCR) techniques.Three types of outward currents were found in BMSCs,including a delayed rectifier K+ current(IKDR),in addition,tetrodotoxin-sensitive sodium current(INa.TTX) and nifedipine-sensitive L-type Ca2+ current(ICa.L) were detected in 24% and 25% BMSCs.Moreover,RT-PCR result revealed the molecular evidence of mRNA for the functional ionic currents,including SCN5A,Kv4.3 and CACNA1C.Conclusion The currents are consistent with the characteristics of excitable cell membrane.

The magnetic anchoring lung nodule positioning device is composed of a target magnet, an anchor magnet, a coaxial puncture needle and a puncture navigation template, through these, a new type of accurate positioning technology for small pulmonary nodules is derived. The device inserts the target magnet into the both sides nearby the lung nodule under the guidance of CT. Helped by the mutual attraction of the two target magnets, they can be fixed in the lung tissue, avoiding the movement in the lung, and accurately positioning the target lung nodule before surgery. In thoracoscopic surgery, the anchor magnet and the target magnet attract each other to achieve the purpose of positioning the target nodule. The device uses the characteristics of non-contact suction of magnetic materials biomedical engineering technology, eliminating the previous procedure of direct interaction with the positioning marks, finally achieves the target of precise positioning of lung nodules and rapid surgical removal.
Humans ; Lung ; Lung Neoplasms ; Magnetic Phenomena ; Magnets ; Solitary Pulmonary Nodule ; Thoracic Surgery, Video-Assisted ; Tomography, X-Ray Computed