Carbon fiber nanoelectrodes(200-300 nm) were firstly used to amperometricaly monitor the dopamine release from single PC12 cells with temporal resolution and especially more higher spatial resolution than those obtain...Carbon fiber nanoelectrodes(200-300 nm) were firstly used to amperometricaly monitor the dopamine release from single PC12 cells with temporal resolution and especially more higher spatial resolution than those obtained by using microelectrodes. When the nanoelectrode was in a distance 1 μm above the PC12 cell, only one peak signal corresponding to a single vesicle exocytotic event was detected caused from the stimulation with 1 mmol/L nicotine. The spatial difference of exocytosis was also detected by placing the electrode onto the different locations of the cell body, the results have demostrated that the spatial distribution of dopamine in cells is not uniform and the time for stimulating secretion is very different. Nanoelectrodes electrochemical method can provide a powerful tool for observing the temporal and spatial characteristics of the secretion from single cells directly.展开更多
0231350 L5/S1神经根病时肌肉功能减弱与相关电生理参数变化/Scelsa S N∥Electromyogr Clin Neurophysiol.-2001,41(3).-145～151 冀医图0231351 与量子释放缺陷有关的突触前先天性肌无力综合征/Maselli R A∥Neurol-ogy.-2001,57(2).-...0231350 L5/S1神经根病时肌肉功能减弱与相关电生理参数变化/Scelsa S N∥Electromyogr Clin Neurophysiol.-2001,41(3).-145～151 冀医图0231351 与量子释放缺陷有关的突触前先天性肌无力综合征/Maselli R A∥Neurol-ogy.-2001,57(2).-279～289展开更多
Intravenous immunoglobulin (IVIg) treatment improves mus- cle strength in Lambert-Eaton myasthenic syndrome (LEMS), butits specific mod e of action is unknown. We have delineated its mode of action on neuromuscular b ...Intravenous immunoglobulin (IVIg) treatment improves mus- cle strength in Lambert-Eaton myasthenic syndrome (LEMS), butits specific mod e of action is unknown. We have delineated its mode of action on neuromuscular b locking properties of LEMS IgG. The effect of sera and purified IgG from six pat ients with LEMS on evoked quantal release was investigated after direct applicat ion to the motor nerve terminal by the perfused macro-patch-clamp electrode in mouse hemidiaphragms. The effect of LEMS IgG was analyzed alone and after coinc ubation with different concentrations of IVIg or its Fab fragments. All LEMS ser a and purified LEMS IgG fractions taken before IVIg treatment inhibited evoked q uantal release in a dose-dependent manner. When LEMS IgG was coincubated with a therapeutic IVIg preparation, presynaptic inhibitory activity of LEMS IgG was d iminished in a dose-dependent fashion. Monovalent Fab fragments were as effecti ve in neutralizing the activity of LEMS IgG as whole IVIg. These direct neutrali zing effects of IVIg may explain its therapeutic efficacy.展开更多
文摘Carbon fiber nanoelectrodes(200-300 nm) were firstly used to amperometricaly monitor the dopamine release from single PC12 cells with temporal resolution and especially more higher spatial resolution than those obtained by using microelectrodes. When the nanoelectrode was in a distance 1 μm above the PC12 cell, only one peak signal corresponding to a single vesicle exocytotic event was detected caused from the stimulation with 1 mmol/L nicotine. The spatial difference of exocytosis was also detected by placing the electrode onto the different locations of the cell body, the results have demostrated that the spatial distribution of dopamine in cells is not uniform and the time for stimulating secretion is very different. Nanoelectrodes electrochemical method can provide a powerful tool for observing the temporal and spatial characteristics of the secretion from single cells directly.
文摘0231350 L5/S1神经根病时肌肉功能减弱与相关电生理参数变化/Scelsa S N∥Electromyogr Clin Neurophysiol.-2001,41(3).-145～151 冀医图0231351 与量子释放缺陷有关的突触前先天性肌无力综合征/Maselli R A∥Neurol-ogy.-2001,57(2).-279～289
文摘Intravenous immunoglobulin (IVIg) treatment improves mus- cle strength in Lambert-Eaton myasthenic syndrome (LEMS), butits specific mod e of action is unknown. We have delineated its mode of action on neuromuscular b locking properties of LEMS IgG. The effect of sera and purified IgG from six pat ients with LEMS on evoked quantal release was investigated after direct applicat ion to the motor nerve terminal by the perfused macro-patch-clamp electrode in mouse hemidiaphragms. The effect of LEMS IgG was analyzed alone and after coinc ubation with different concentrations of IVIg or its Fab fragments. All LEMS ser a and purified LEMS IgG fractions taken before IVIg treatment inhibited evoked q uantal release in a dose-dependent manner. When LEMS IgG was coincubated with a therapeutic IVIg preparation, presynaptic inhibitory activity of LEMS IgG was d iminished in a dose-dependent fashion. Monovalent Fab fragments were as effecti ve in neutralizing the activity of LEMS IgG as whole IVIg. These direct neutrali zing effects of IVIg may explain its therapeutic efficacy.
