Aim To investigate the effect of U50488H(a selective κ-opioid receptor agonist)and isoproterenol(ISO,a β-adrenergic receptor agonist)on ventricular arrhythmias and Cx43 during myocardial ischemia and reperfusion in rats.Methods 60 rats were randomly divided into five groups,ie,normal control group,I/R group,ISO+I/R group,U50488H+ISO+I/R group,Nor-BNI+U50488H+ISO+I/R group.The incidence of ventricular arrhythmias and arrhythmia score were determined. The expression of Cx43mRNA was tested by RT-PCR.The expression of Cx43 protein in myocardial cell was tested by an immunohistochemical approach with a quantitative imaging system.Results ① Compared with the I/R group,arrhythmia score was increased with administration of ISO(P<0.05).U50488H intravenously injected before ISO significantly decreased the arrhythmia score(P<0.05).② Compared with the normal control group,the expression of Cx43 mRNA was decreased in the I/R group(P<0.05).With administration of ISO,the amount of Cx43 mRNA was not significantly increased.③ Compared with normal control group,total and phosphorylated Cx43 proteins were significantly decreased in the I/R group(P<0.05),and the phosphorylated Cx43 was also decreased with administration of ISO.Compared with ISO+I/R group,phosphorylated Cx43 was increased with administration of U50488H (P<0.05).Conclusion κ-opioid receptor agonist U50488 H antagonizes the arrhythmias through the regulation of Cx43 during myocardial ischemia and reperfusion via inhibiting β-adrenergic receptor pathway.

Objective To analyze the clinicopathological features,immunohistochemistry and differential diagnosis of metaplastic breast carcinoma.Methods A total of 32 cases of patients with metaplastic breast cancer in our hospital from March 2013 to March 2016 was randomly selected.The specimens were fixed with 4％ neutral formaldehyde solution,then dehydrated,embedded,sliced,stained with HE,and immunohistochemically stained with immunohistochemical staining machine,and then the results of macroscopic examination,microscopic examination and immunohistochemical examination were analyzed.Results Metaplastic breast cancer was lack of clear boundaries,and had no envelope.The tumor diameter was 1-5 cm,and its average was(3.1 ±1.2) cm.Section was tough and solid.Some had nodular shape,and their color was gray.Some had cysts appearance in the section.Among the 32 patients,20 patients underwent sentinel lymph node biopsy without cancer metastasis,and 12 patients underwent axillary lymph node dissection,including 8 cases with axillary lymph node metastasis;32 patients were presented as estrogen receptor (ER) (-),progesterone receptor(PR) (-),epidermal growth factor receptor-2 (HER-2) (-),broad spectrum CK (+),28 patients presented as epidermal growth factor receptor(EGFR)(+),20 patients presented as CK5/6 (+),and 8 patients presented as p53 (+),myoepithelial carcinoma p63 (+),respectively accounting for 100.0％,87.5 ％,62.5 ％ and 25.0％ in their total number.A total of 32 cases of patients with metaplastic breast carcinoma was divided into two types according to the metaplasia:pure epithelial type,including 4 cases of squamous cell carcinoma,2 cases of glandular squamous cell carcinoma and 13 cases of adenocarcinoma differentiated by spindle cell;epithelial/mesenchymal metaplastic carcinoma,its heterologous elements including 3 cases of sarcomatoid components,3 cases of rhabdomyosarcoma-like ingredients and 7 cases of ossification of cartilage and natural ingredients.Conclusion Metaplastic breast cancer,ER(-),PR(-),and HER-2 (-) should be identified with primary breast sarcoma,malignant follicular tumor,sarcomatosis and desmoplastic breast cancer.