BACKGROUND: 6-hydroxydopamine, as an endogenous toxic factor in the pathogenesis of Parkinson's disease, participates in oxidative stress. N-acetylcysteine resists oxidation and removes free radicals effectively.OBJECTIVE: To investigate the toxicity of 6-hydroxydopamine in bone marrow stromal cells and the antagonistic effect of N-acetylcysteine on it. METHODS: Bone marrow stromal cells of Sprague-Dawley rats were cultured in vitro. Bone marrow stromal cells of passage 3 were treated with 6-hydroxydopamine with the final concentrations of 0,0.05,0.1g/L and N-acetylcysteine with the final concentrations of 0, 0.075,0.3,1.2,4.8g/L, respectively.RESULTS AND CONCLUSION: MTT assay showed that 6-hydroxydopamine (0.05 and 0.1 g/L) significantly decreased the viability of bone marrow stromal cells. This toxic effect of 6-hydroxydopamine was significantly inhibited by 0.3 g/L N-acetylcysteine. It suggests that antioxidant N-acetylcysteine may affect the toxic action of 6-hydroxydopamine.

Objective To analyze the electrophysiological characteristics of patients with severe Guillain-Barré syndrome and the related factors causing poor prognosis,and evaluate the value of neuroelectrophysiology in predicting poor prognosis. Methods The clinical data of 78 GBS patients admitted to our hospital from March 2020 to May 2022 were selected,divided into mild (n=52) and severe (n=26) according to the severity of the disease,and the good group (n=45) and bad group (n=33) according to the prognosis;Compare the clinical data of different groups,compare the neuroelectrophysiological characteristics of patients in different disease groups,analyze the relevant factors causing poor prognosis,build a line chart prediction model and verify it;analyze the value of electrophysiological characteristics for poor prognosis through the subject's working characteristics (ROC) curve. Results A comparison of the clinical data of two groups of patients with different severity found that the incidence of facial paralysis,chest tightness,diarrhea,mechanical ventilation,autonomic nervous dysfunction and other autoimmune diseases in the severe group was significantly higher than that of patients in the mild group (P<0.05). By comparing the electrophysiological characteristics of the two groups,it was found that the total peroneal nerve conduction rate and tibia motor conduction rate of the severe severe group were significantly lower than that of the mild group,while the F-wave abnormality rate and dCMAP wave amplitude abnormality rate were significantly higher than that of the mild group (P<0.05);single-factor and multi-factor results showed that the pre-hospital course of hospitalization was >2 weeks,elevated cerebrospinal fluid protein,and MRC score ≤30 at hospital,mechanical ventilation,combined with other autoimmune diseases,slowing of the total peroneal nerve conduction rate,slowing down the tibial motion conduction rate,increased F-wave abnormality rate,increased amplitude abnormality of dCMAP and axial cord injury are all risk factors affecting poor prognosis (OR values are greater than 1,P<0.05);the total score of the line chart prediction model is 613 points,and the corresponding adverse prognosis probability is 74.56%,which has good distinction,accuracy and effectiveness;the ROC curve obtains the total peroneal nerve conduction rate,tibial nerve motion conduction rate,F-wave abnormality,dCMAP wave amplitude abnormality four the area,positive/negative prediction value,sensitivity and specificity under the ROC curve of the joint prediction are significantly higher than that of individual predictions,with better prediction performance. Conclusion Analyzing the electrophysiological characteristics of severe GBS patients is conducive to a clearer understanding of the severity of patients' condition. It has a very important predictive value for poor prognosis,and is worth popularizing and applying in clinic.