1.Study on propagation form of nerve impulse waves.
Yuzhen CHAI ; Jianwen ZHANG ; Guitong YANG
Journal of Biomedical Engineering 2008;25(5):1184-1188
Hodgkin-Huxley model is the indispensable mathematics basis for the study of neuro-electro-physiology. But so far, there is few analytic study about H-H neuron model. In this paper, the features of the classical H-H model are analyzed, and then a simplified H-H model and Nagumo equation are proposed, and their solitary wave solutions are first obtained with the homogeneous balance method. The study shows that nerve impulse may propagate with the mode of solitary wave.
Action Potentials
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physiology
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Humans
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Mathematics
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Membrane Potentials
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physiology
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Models, Neurological
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Neural Conduction
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physiology
2.Effect of amiodarone and metoprolol on platelet activation, fibrinolytic activity and vasoactive mediators in acute myocardial infarction in rabbits
Hengliang LIU ; Yunkai KANG ; Lihua WU ; Yun KAI ; Dongqin HAO ; Jianwen CHAI
Chinese Journal of Pathophysiology 1986;0(04):-
AIM: To explore the significance of platelet activation, fibrinolytic activity and the changes of vasoactive mediators in acute myocardial infarction in rabbits and the intervention of amiodarone and metoprolol. METHODS: Fifty New Zealand white rabbits were randomly assigned to five groups, ten for each. Group Ⅰ: sham group, group Ⅱ: acute myocardial infarction(AMI) group, group Ⅲ: AMI and lidocaine group, group Ⅳ: AMI and amiodarone group, group Ⅴ: AMI and metoprolol group.The middle point of left ventricular coronary artery was ligated (groupⅡ,Ⅲ, Ⅳ and Ⅴ ) or a sham ligation(group Ⅰ). Four hours later, blood was collected for measuring plasma concentration of TXB 2, 6-Keto-PGF 1?, ET, NO, plasma activity of t-Pa and PAI.After that, the heart was taken out to evaluate the infarction size(IS). RESULTS: Plasma concentration of TXB 2, ET, NO and plasma activity of PAI were significantly higher in groupⅡ,Ⅲ, Ⅳ and Ⅴ than those in group Ⅰ(P0.05).Compared to group Ⅱ, plasma concentration of ET, NO and PAI activity were significantly decresed (P
3.Progress of research on the technology of preservation and repair of severed limbs
Rongji ZHANG ; Ji SHI ; Jianwen ZHAO ; Qing LI ; Jianzheng ZHANG ; Wei CHAI ; Tiansheng SUN
Chinese Journal of Orthopaedics 2024;44(22):1503-1508
Limb preservation techniques of severed limbs play an important role in autologous replantation or allografting. At present, static cold storage (SCS) remains the gold standard for the in vitro preservation of severed limbs, which minimizes oxygen and energy metabolism. However, with a relatively short time window of 4-6 hours, SCS is insufficient for clinical transfer, injury management and other medical resources. To address this issue, researchers have initiated investigations into alternative methods of supplying oxygen and nutrients to severed limbs, leading to the development of mechanical perfusion technology and per-sufflation technology. Mechanical perfusion technology aims to clear metabolic waste and provide essential nutrients by mimicking a physiological state, thereby prolonging the preservation time and improving the outcome of the repair. Per-sufflation technology aims to deliver oxygen directly to the tissue using a vascular system to maintain tissue integrity. With these emerging technologies showing great promise, further exploration and refinement are needed to address their time constraints and complexity in clinical work. Furthermore, for severed limbs that are not suitable for immediate reimplantation, autologous heterotopic parasitism techniques and temporary endovascular shunts offer promising avenues for preservation. Autologous heterotopic parasitism techniques maintain tissue viability by constructing a temporary parasitic environment, while temporary endovascular shunts establish a temporary vascular access at the damaged site to deliver donor blood, thereby maintaining blood flow and promoting repair. Xenogeneic cross-circulation techniques combine recent advances from multiple disciplines and demonstrate remarkable potential; however, they currently face challenges such as ethics, immune rejection, and technical complexity. The combination of these novel techniques has led to a significant advancement in the field of limb preservation and repair. This article aims to provide an overview of the current research status and development of static cold storage, pre-sufflation, mechanical perfusion preservation and temporary ectopic parasitic preservation techniques in limb preservation over recent years, providing information for clinical work, promoting the development of limb reimplantation and transplantation techniques in China and further consolidating China's leadership in the field of amputation reimplantation and allograft transplantation.