Objective To investigate the effect of Nifekalant on action potential of atrium and pulmonary vein and the possible clinical efficacy of Nifekalant against atrial tachyarrhythmias.Methods left and right atrium and pulmonary vein removed from 15 white rabbits were made into tissue preparations(0.5 cm?1.5 cm).Action potential was induced by electric stimulation with twofold capture threshold and recorded by standard glass microelectrode technique.Effective refractory periods of left and right atrial and pulmonary vein tissues were measured with burst and programmed stimulation.The Action potentials and effective refractory periods of various tissues were compared between before and after irrigation of Tyrodes fluid containing Nifekalant of 2.13 mg/L.Results After irrigation of Tyrodes fluid containing Nifekalant,APD90 was prolonged[(51?16)ms vs(78?33)ms,P

Objective To investigate the clinical significance of early diagnosis and treatment of impal-pable breast tumor.Methods From Jan.2007 to Dec.2014, 570 patients with impalpable breast tumor were treated.Among them, 107 patients were found with breast nodules by ultrasound scan , 340 patients were found with nodules , calcification or distort gland structure and 123 patients were found with nipple discharge by mam-mography .They were biopsied with various methods such as wire localization guided by ultrasound , X-ray mam-mography and fiberoptic ductoscopy .All patients were treated routinely and followed up .Results The his-topathological examination results were as follows:134 cases of breast cancer (23.51%) and 436 cases of benign lesions.44 breast cancer patients were localized by ultrasound , 78 cases were localized by X-ray mammography, and 12 cases were localized by fiberoptic ductoscopy .All lesions were accurately localized and excised .During the two-year follow up, no recurrence or metastasis occurred .Conclusion Early diagnosis and treatment of im-palpable breast tumor can improve early diagnosis level of breast cancer .

Objective To investigate the clinical correlated problems of immediate breast reconstruction with silicagel prosthesis after modified radical mastectomy.Methods From Jun.2007 to Dec.2011,30 patients were treated with skin sparing modified mastectomy and immediate reconstruction by placing silicone implants into submuscle.15 cases were reserved the nipple-areola complexes.All patients were treated routinely after operation.Results Objective evaluation after operation showed that the excellent rate reached to 90.0％,and subjective evaluation showed that the excellent rate reached to 93.3％.Two cases suffered under-flap hydrops,one case suffered capsular contraction,one case suffered flap ischemia and superficial necrosis of nipple-areola complex,one case suffered gel metastasis,and one cases suffered obvious asymmetry.All the cases were followed up for 12 to 54 months,among whom one case had hepatic and bone metastasis,and the others had no recurrence or metastasis.Conclusions Immediate breast reconstruction with silicagel prosthesis after modified radical mastectomy was proven to be an effective and safe method,with no increase of local recurrence.The modification of operation may avoid the risk of complications.