Gap junction, a special membrane structure communicating many kinds of cells, is composed of connexin.Changes of connexin levels and distribution can lead to changes of conduction velocity of electric couple and increase of reentrant arrhythmia, finally to atrial fibrillation. This article elucidates the relationship between cardiac gap junction protein connexin and atrial fibrillation.

Objective To determine the effects of hypoxia inducible factor-1α(HIF-1α) expression on postoperative adjuvant radiotherapy in esophageal carcinoma. Methods 95 cases with esophageal carcinoms who received radical operation were analyzed with followed-up data from 1995 to 1998.Expression of HIF-1α in 45 patients with esophageal carcinoma who received radiotherapy after radical operation were deternlined by immunohistochemical method in contrast with 50 patients with esophageal carcinoma received surgery alone.Kaplan-Meier method and COX proportional hazard model were used to analyze.Results The positive expression of HIF-1α in esophageal carcinoma was observed mainly in the nucleus of tumor cells.The positive expression rate of HIF-1α in esophageal carcinoma was 58.9%.The expression of HIF-1α had no relationship with age,sex,histologic subtype and T stage,but had positive relationship with recurrence and distant metastasis.There was significant difference between patients with positive and negative HIF-1α protein expression in surgery alone and postoperation radiotherapy group. COX model analysis showed that HIF-1α had separate and significant impacts on prognosis in surgery group and surgery plus radiotherapy group. Conclusion Over expression of HIF-1α protein suggests a poor prognosis,and has tendency to resist radiotherapy in esophageal carcinoma.