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For the ideal preclinical animal model of hepatitis B virus (HBV), its hepatocytes should allow HBV entry and cccDNA generation and have both innate and adaptive immune systems. However, HBV only naturally infects humans and chimpanzees due to highly restricted species specificity, and no effective model has been established so far to truly reflect the immune mechanism and pathogenesis of HBV infection. This article reviews five commonly used mouse models, i.e., HBV transgenic model, HBV plasmid DNA hydrodynamic injection model, AAV-HBV transfection model, cccDNA surrogate model, and human-mouse chimeric liver model, and looks forward to the new models that will appear in the future, such as hNTCP transgenic cynomolgus monkey, rhesus monkey, or pig models, so as to provide a reference for researchers to select these models, accelerate the process of drug screening, validate new therapies, and better solve the problems of HBV biological pathogenesis.
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AIM:To investigate the effect of cervical lymphatic blockage(CLB)on blood pressure(BP)in conscious unrestrained rats.METHODS:Sprague-Dawley(SD)rats were adopted and randomly divided into two groups as Sham operated group and CLB group.By means of monitoring hemodynamic change in conscious unrestrained rats,twenty-four-hour blood pressure(SBP,DBP and MAP),blood pressure variability(BPV),heart rate(HR)and heart rate variability(HRV)were respectively measured before sham and cervical lymphatic blockage operation as their baseline and at 1st,3rd,7th,11th,15th days after operation.Meanwhile,arterial baroreflex sensitivity(BRS)was measured before and at 1st,7th,15th days after operation.RESULTS:SBP,DBP,MAP and HR significantly decreased at 1st day after CLB operation and their lowest values appeared at 7th day.The tendency of their alternation was descending early and then ascending whereas reverse alterations of BPV and HRV were observed.BRS reduced in CLB rats with no apparent recovery from 7th day.CONCLUSION:CLB results in reduction of blood pressure and dysfunction of nervous regulation on cardiovascular system in conscious unrestrained rats.
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Objective:To elucidate the etiology of the impairment of myocardial cells in Keshan disease. Methods:With intracellular microelectrode technique, we observed the electrophysiological changes of the eight groups of rats fed separately:normal, low Se, low Se+high VC, low Cr, low Cr+high VC, low Se+low Cr and low Se+low Cr+high VC fodders. Results:Compared with the control, there was no change in low Cr group. However, in low Se group, RP and APA decreased, APD 50 and APD 90 prolonged. In low Se+low Cr group, APA decreased, APD 50 and APD 90 prolonged significantly. In low Se with high vitamin C groups, though RP still decreased, no change had been detected on APA and APD. Conclusion:It is suggested that Se and Cr deficiency may jointly change the electrophysiological properties of myocardial cells significantly. However, vitamin C may protect myocardial cells against the injury effectively.
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Objective: To observe the effects of vitamin C(VC)on the electrophysiological property of myocardial cells of the rats fed with low selenium and high cadmium fodder. Method: Eight groups of rats were fed separately with: normal (2 groups), high Cd, high Cd+high VC, low Se+high Cd, low Se+high Cd+high VC, high Se+high Cd and high Se+high Cd+high VC fodder for 14 w. With intracellular microelectrode technique, the electrophysiological changes of rats were observed. Results:Compared with the control, there were no changes in high Cd+high VC group and in high Se+high Cd+high VC group. However,in high Cd group, RP and APA decreased, APD50 and APD90 prolonged; in low Se+high Cd group ,RP and APA decreased, APD50 and APD90 prolonged significantly; in low Se+high Cd+high VC group and high Se+high Cd group, though RP still decreased, no change had been detected on APA and APD. Conclusion: Se deficiency and simultaneous Cd overabundance may change the electrophysiological properties of myocardial cells of the rats significantly. However, VC may protect myocardial cells against the injury effectively.