Objective To investigate the feasibility of bacterial cellulose patch to repair and reconstruct rabbit tracheal defect, so as to lay the foundation for the development of bacterial cellulose artificial trachea. Methods Thirty adult rabbits (weighing, 2.5-3.5 kg) were selected to establish full-thickness defect of the cervical trachea (1.0 cm×0.6 cm in size) which involved the anterior and side walls and 2-3 rings. Defect was repaired with sheet bacterial cellulose (1.2 cm in diameter and 6 layers) in experimental group (n=15), and with autologous cervical fascia in control group (n=15). The general condition of the animals was observed after operation; after 4, 8, and 12 weeks, the samples were obtained for measuring the tracheal stenosis degree, counting new microvessels, and observing lumen reconstruction situation by scanning electron microscope. Results Three rabbits died of infection, tracheal stenosis, or asphyxia caused by airway secretions retention in 2 groups respectively, and the other rabbits survived to the end of experiment. Gross observation showed that reconstruction materials gradually adhered to adjacent tissue and were enwrapped by connective tissue, small blood vessels like nutrient vessel were seen in 2 groups; no significant difference was found in the tracheal lumen stenosis degree between 2 groups (P > 0.05). Histological observation showed that the continuous growth of mucosal epithelial cells was observed near patch and anastomosis site with time, and cell morphology gradually turned mature in experimental group; while mucosal epithelial cells arranged loosely in control group. At each time point, new capillaries of experimental group were significantly more than those of control group (P < 0.05). Scanning electron microscope observation showed the continuous epithelioid cells were observed at anastomosis site with time, and gradually grew into the middle of the patch in experimental group; while less and discontinuous epithelioid cells were observed in control group. Conclusion Bacterial cellulose patch is feasible to reconstruct cervical tracheal defect in rabbits, and the new mucosa is formed early and completely, so it is expected to be used as artificial trachea material.
Patch-clamp is used to study all sorts of ionic channels and their regulations with measuring pA current of cell ionic channel, but the fast capacitance (C-fast) compensation and slow capacitance (C-slow) compensation transient currents are caused by measuring objects and measuring instruments themselves which will change the properties of action potentials. The present paper firstly discusses the C-Fast transient currents affecting membrane capacitance and membrane potential, and then draws a conclusion that the changes of membrane potential affect the properties of action potential through analyzing the changes of membrane potential in H-H model. Based on this conclusion, we discuss the influence mechanisms mainly through the analysis of traditional C-fast compensation errors, and focus discussion on the shape of electrode capacitance affecting C-fast. This method can not only improve the compensation speed greatly, but also improve the compensation precision from the electrode shape as much as possible.