Generation, characterization, and application in serodiagnosis of recombinant swine vesicular disease virus-like particles

Swine vesicular disease (SVD) is a highly contagious viral disease that causes vesicular disease in pigs. The importance of the disease is due to its indistinguishable clinical signs from those of foot-and-mouth disease, which prevents international trade of swine and related products. SVD-specific antibody detection via an enzyme-linked immunosorbent assay (ELISA) is the most versatile and commonly used method for SVD surveillance and export certification. Inactivated SVD virus is the commonly used antigen in SVD-related ELISA. A recombinant SVD virus-like particle (VLP) was generated by using a Bac-to-Bac baculovirus expression system. Results of SVD-VLP analyses from electron microscopy, western blotting, immunofluorescent assay, and mass spectrometry showed that the recombinant SVD-VLP morphologically resemble authentic SVD viruses. The SVD-VLP was evaluated as a replacement for inactivated whole SVD virus in competitive and isotype-specific ELISAs for the detection of antibodies against SVD virus. The recombinant SVD-VLP assay produced results similar to those from inactivated whole virus antigen ELISA. The VLP-based ELISA results were comparable to those from the virus neutralization test for antibody detection in pigs experimentally inoculated with SVD virus. Use of the recombinant SVD-VLP is a safe and valuable alternative to using SVD virus antigen in diagnostic assays.

Dendranthema morifolium attenuated the reduction of contraction of isolated heart and cardiomyocytes induced by ischemia/reperfusion / 中国病理生理杂志

AIM: To investigate the effect of Dendranthema morifolium (Ramat) Tzvel (DM) on isolated rat heart and ventricular myocytes during ischemia/anoxia and reperfusion/reoxygenation.METHODS: The Langendorff perfused rat hearts were used to measure intraventricular pressure and coronary flow. The cell contraction and intracellular calcium transient in enzymatically isolated ventricular myocytes were determined. RESULTS: (1) DM (0.5 g/L) significantly attenuated the inhibitory effects induced by ischemia/reperfusion on left ventricular developed pressure (LVDP), ?dp/dt max, coronary flow and LVDP?HR, meanwhile increased the content of SOD and decreased the content of MDA in the myocardium; (2) DM (0.5 g/L) attenuated the inhibitory effects of anoxia and reoxygenation on [Ca 2+]i transient and cell contraction in isolated ventricular myocytes. CONCLUSION: DM attenuated the effects on contractility and intracellular calcium induced by ischemia/anoxia and reperfusion/reoxygenation in the isolated rat heart and the ventricular myocytes. The mechanism might be related to increase in SOD activity and maintaining [Ca 2+]i homeostasis.

Salvia miltiorrhiza antagonized the alterations of contraction and intracellular calcium of rat ventricular cardiomyocytes induced by anoxia and reoxygenation / 中国病理生理杂志

AIM: To study the effect of salvia miltiorrhiza (SM) on cell contraction and intracellular calcium of enzymatically isolated rat ventricular myocytes during normoxia and anoxia/reoxygenation. METHODS: Contraction and intracellular calcium were determined with video tracking system and spectrofluorometric method, and the chemical anoxic method was employed. RESULTS: The ?d L /d t max , dL of cell contraction and the amplitude of [Ca 2+ ] i in the cardiomyocytes following SM treatment were decreased in a dose-dependent manner. During anoxia, the ?d L /d t max , dL and amplitude of [Ca 2+ ] i were decreased, while the diastolic Ca 2+ level was elevated compared with control group. All the contractile parameters and the diastolic Ca 2+ level were back toward pretreatment values during reoxygenation, but could not return to control level. After the treatment with SM (3 g/L), ?d L /d t max and dL of cell contraction and the amplitude of [Ca 2+ ] i were higher and the diastolic Ca 2+ level was lower than those in anoxia/reoxygenation group. CONCLUSION: SM antagonized effects of anoxia and reoxygenation on cell contraction and intracellular calcium in isolated ventricular myocytes.