【Abstract】Objective To investigate the relationship of expressions of cylooxygenase-2 (COX-2) and hypoxia-inducible factor-1α (HIF-1α) in hepatocelluar carcinoma (HCC) and the possible antineoplastic mechanism of selective COX-2 inhibitor. Methods The expressions of COX-2 and HIF-1α in 53 cases of HCC tissues were detected immunohistochemically. Western blot was employed to evaluate the effects of variant concentration of COX-2 inhibitor meloxicam on expression of HIF-1α in Cobaltchloridestimulated SMMC-7721 cell. ResultsOf 53 tumor tissues, the expression of COX-2 was 22/53 (41.5%) bly positive stained, 11/53 (20.8%) positive stained, and 20/53 (37.7%) negative stained. Meanwhile the expression of HIF-1α was 18/53 （34.0%） bly positive stained, 18/53 （34.0%）positive stained, 17/53（32.1%） negative stained. The expression of COX-2 was correlated positively with HIF-1α in HCC （r=0.440, P＜0.01）. The expression of HIF-1α increased sharply from 0.185±0.057 (no Cobaltchloride-stimulated) to 1.011±0.131 (Cobaltchloride-stimulated), and meloxicam could inhibit the expression of HIF-1α at either condition (P＜0.05). ConclusionMeloxicam could inhibit the expression of HIF-1α in a concentration-dependent manner in the Cobaltchloridestimulated SMMC-7721 cell. The antineoplastic activity of selective COX-2 inhibitor was possibly, at least in part, mediated by HIF-1α.
The implantation of biventricular assist device (BiVAD) is more challenging than that of left ventricular assist device for the interaction in the process of multiple input and output. Besides, ventricular assist device (VAD) often runs in constant speed (CS) mode in clinical use and thus BiVAD also faces the problems of low pulsation and imbalance of blood volume between systemic circulation and pulmonary circulation. In this paper, a delay assist mode for a VAD by shortening the support time of VAD was put forward. Then, the effect of the delay mode on cardiac output, pulsation and the function of the aortic valve was observed by numerical method and the rules of hemodynamics were revealed. The research showed that compared with VAD supported in CS mode, the VAD using delay mode in systolic and diastolic period proposed in this paper could meet the demand of cardiac output perfusion and restore the function of the arterial valves. The open ratio of aortic valve (AV) and pulmonary valve (PV) increased with the time set in delay mode, and the blood through the AV/PV helped to balance the left and the right cardiac volume. Besides, delay mode also improved the pulsation index of arterial blood flow, which is conducive to the recovery of the ventricular pulse function of patients.