ABSTRACT
Objective:To study the effects of tetramethylpyrazine on the expressions of ferroptosis related molecules after spinal cord injury; To explore the mechanism of tetramethylpyrazine promoting the repair of spinal cord injury (SCI).Methods:Totally 36 SD rats were divided into sham-operation group, model group and tetramethylpyrazine group according to random number table method, with 12 rats in each group. The rats in the sham-operation group underwent laminectomy without injury to the spinal cord. The SCI model was prepared in the other two groups. The rats in the tetramethylpyrazine group were intraperitoneally injected with tetramethylpyrazine of 80 mg/kg, and the rats in the sham-operation group and model group were intraperitoneally injected with the same volume of normal saline, once a day, continuous intervention for 28 days. One day before operation and 1, 3, 5, 7, 14, 21, 28 days after operation, BBB limb motor function score was used to evaluate the limb motor function of rats. Nissl staining was used to observe the morphology of neurons. Prussian staining was used to observe iron deposition. Assay kit was used to detect the contents of MDA and ROS in spinal cord tissue. Western blot was used to detect the protein expressions of xCT, GPX4 and ACSL4, and qPCR was used to detect the mRNA expressions of mRNA of xCT, GPX4 and ACSL4.Results:On the 14th, 21st and 28th days after operation, compared with the model group, the BBB score of tetramethylpyrazine group increased ( P<0.01); tetramethylpyrazine could significantly improve the morphology and structure of neurons and reduce the iron content in spinal cord tissue; compared with the model group, the contents of MDA and ROS in the spinal cord tissue of tetramethylpyrazine group decreased ( P<0.01); the levels of xCT and GPX4 mRNA and protein increased ( P<0.01), while the expression of ACSL4 mRNA and protein decreased ( P<0.01). Conclusion:Tetramethylpyrazine can regulate lipid peroxidation by regulating the expressions of ferroptosis related molecules, which is conducive to the recovery of limb motor function in rats with spinal cord injury.
ABSTRACT
This study designed an audio signal acquisition system to achieve real-time detection of R peak for heart rate variability (HRV) analysis, substituting ECG-specific data acquisition board with sound card. It is proved that the R peak with low frequency can be gathered by sound card. The comparison with PowerLab signal acquisition system has shown that the acquisition system of R peak could accurately detect the R peak. The R peak detected by sound card and PowerLab signal acquisition system completely overlap each other, while RR intervals has no difference. The HRV analysis was accurate and reliable with the RR interval from sound card. This low cost, high performance, strong compatibility and easy upgraded acquisition system of R peak compared with the traditional data acquisition board has the value of practical uses and might have broad applications in the future.
Subject(s)
Humans , Algorithms , Electrocardiography , Methods , Heart Rate , Physiology , Monitoring, Physiologic , Signal Processing, Computer-Assisted , SoundABSTRACT
This study designed one index of HRV from Poincaré plot named 5SSD1 by the present authors, which can describe the characteristics of the heart rate dynamics with 5-second data. We also investigated the feasibility of its clinical application in real-time monitoring of the activity of autonomic nervous system. We studied 20 patients scheduled for oral maxillofacial surgery. ECG recording was obtained when kept awake and anesthetic states, respectively. We calculated the correlation coefficients between the 5SSD1 and the other quantitative indicators, such as 5-minute HRV in the time domain, the frequency domain, and the Poincaré plot families. The correlation between 5SSD1 and indicators, such as rMSSD, HF and SD1 of 5-minute HRV was significantly high, with r=0.995, 0.895, 0.996, respectively, at P<0.01 for all. However, the correlation between 5SSD1 and the other indicators of 5-minute HRV was relatively poor. It was proved that 5SSD1 could be used to assess the activities of the autonomic nervous system in real-time, and the stable and reliable results might play more roles in the clinical applications.