OBJECTIVETo observe the changes of surface ECG and cell couplings between sinoatrial node cells and myocardial cells following transplantion of pedicled autologous sinoatrial node tissue graft into the right ventricle of a canine model of complete atrioventricular block.

METHODSTen healthy dogs were randomized into transplantation group and control group. Pedicled autologous sinoatrial node tissue grafts were transplanted into the right ventricle in the transplantation group, while the sinoatrial nodes were only excised in the control group after placement of temporary myocardial pacing wires. The changes of surface ECG were observed at 1, 2, 3 and 4 weeks postoperatively. At 4 weeks, complete atrioventricular block was induced in the dogs by radiofrequency ablation of the His bundle. The heart rate of the dogs in both groups were recorded after the injection of isoproternol (ISO) from the femoral vein, and the transplanted tissue graft was observed under optical and transmission electron microscopes.

RESULTSNo significant changes occurred in the surface ECG. All the dogs showed ECG waveforms specific of complete heart block after the ablation, and the ventricular heart rates were similar between the two groups (P>0.05). The ventricular heart rate did not undergo obvious changes after ISO injection (P>0.05). The transplanted pedicled autologous sinoatrial node survived in the dogs and the sinoatrial node cells established desmosome junctions with the myocardial cells, but the number of junctions was not sufficient to support heart pacing.

CONCLUSIONDesmosome junction can occur between ventricular myocardial cells and sinoatrial node cells at the edge of transplanted pedicled autologous sinoatrial node tissue.

Animals ; Atrioventricular Block ; physiopathology ; surgery ; Cardiotonic Agents ; pharmacology ; Dogs ; Electrocardiography ; Female ; Heart Rate ; drug effects ; Heart Ventricles ; surgery ; Intercellular Junctions ; Isoproterenol ; pharmacology ; Male ; Myocardium ; cytology ; Sinoatrial Node ; cytology ; transplantation ; Tissue Transplantation ; Transplantation, Autologous

Objective:To explore the expression level of exosomal miR-218-5p in the serum of patients with colorectal cancer (CRC) and its correlation with the clinical pathological characteristics, and evaluate its diagnostic efficacy in CRC.Methods:A group of 78 patients with colorectal cancer diagnosed in Tongji Hospital affiliated to Tongji University from October 2016 to October 2018 were selected. Blood was collected before operation and serum was preserved. Forty cases of healthy people in the same period were selected as the control group. ExoQuick kit was used to extract serum exosomes. Transmission electron microscope, NTA and western blot were used to identify the morphology and molecular phenotype of exosomes. MiRNeasy kit was used to extract total RNA in serum exosomes. Real-time fluorescent quantitative PCR (RT-qPCR) was used to detect the expression level of serum exosomal miR-218-5p in each group. CRC patients were divided into high expression and low expression groups using the median relative expression level of miR-218-5p as the cut off value, and the four-square chi-square test (χ 2 test) was used to judge the relationship between miR-218-5p and clinicopathological features. The receiver operating characteristic (ROC) curve was used to evaluate the diagnostic efficacy of miR-218-5p in colorectal cancer. Results:The exosomes in serum were successfully extracted by kit method. The expression level of serum exosomal miR-218-5p in patients with colorectal cancer was significantly lower than that in normal healthy people [0.566(0.364, 0.850) vs 1.054(0.781, 1.709), P<0.001]. The low expression level was significantly better then the correlated with tumor size, TNM stage, lymph node metastasis and depth of invasion (all P<0.05). Receiver operating characteristic (ROC) analysis showed that the area under the curve (AUC) of serum exosomal miR-218-5p for the diagnosis of CRC was 0.827 (95% CI 0.754-0.900), which was significantly better than the conventional tumor marker carcinoembryonic antigen CEA (AUC =0.718, 95% CI 0.626-0.811) and carbohydrate antigen CA199 (AUC = 0.661, 95% CI 0.564-0.758). Conclusions:The down-regulation of miR-218-5p expression in serum exosomes of colorectal cancer patients is associated with a variety of adverse clinicopathological factors, which has the potential to become a diagnostic biomarker for colorectal cancer.

Carbonic anhydrase IX (CAIX) is a transmembrane protein that is specifically overexpressed on the surface of hypoxic tumor cells. With the function of regulating the acidity of tumor cells both inside and outside, CAIX is closely related to tumor proliferation, invasion and metastasis. Therefore, CAIX is a promising target for tumor imaging and therapy. Herein, we summarized recent advances in CAIX-based tumor imaging, therapy and theranostics, and prospected future applications of using CAIX as an anti-tumor target.
Carbonic Anhydrase IX ; Carbonic Anhydrases/metabolism* ; Cell Line, Tumor