Focal hole versus screw stimulation to prevent false negative results in detecting pedicle breaches during spinal instrumentation

ObjectiveWe describe a stimulus-evoked EMG approach to minimize false negative results in detecting pedicle breaches during lumbosacral spinal instrumentation.MethodsIn 36 patients receiving 176 lumbosacral pedicle screws, EMG threshold to nerve root activation was determined using a focal probe inserted into the pilot hole at a depth, customized to the individual patients, suitable to position the stimulating tip at the point closest to the tested nerve root. Threshold to screw stimulation was also determined.ResultsMean EMG thresholds in 161 correctly fashioned pedicle instrumentations were 7.5 mA ± 2.46 after focal hole stimulation and 21.8 mA ± 6.8 after screw stimulation. Direct comparison between both thresholds in individual pedicles showed that screw stimulation was always biased by an unpredictable leakage of the stimulating current ranging from 10 to 90%. False negative results were never observed with hole stimulation but this was not true with screw stimulation.ConclusionsFocal hole stimulation, unlike screw stimulation, approaches absolute EMG threshold as shown by the lower normal limit (2.6 mA; p < 0.05) that borders the upper limit of threshold to direct activation of the exposed root.SignificanceThe technique provides an early warning of a possible pedicle breakthrough before insertion of the more harmful, larger and threaded screw.     

肉毒毒素注射引起的不良反应

肉毒毒素注射引起的不良反应,是药物本身的组成成分引起的与用药目的无关的有害反应,与医生注射方式和注射技术无关。尽管肉毒毒素生产厂家的药品说明书上也有提示,但其所提供的信息不够全面,也未必能引起医生的足够重视。目前文献上多为散发病例。为此作者对过去20年有关肉毒毒素注射引起的过敏反应、肉瘤样肉芽肿、眼睑水肿、流感样症状等相关不良反应的临床表现、发病机制与治疗方法进行综述。     

Botulinum toxin blocks mast cells and prevents rosacea like inflammation

Background

Rosacea is a chronic inflammatory skin condition whose etiology has been linked to mast cells and the antimicrobial peptide cathelicidin LL-37. Individuals with refractory disease have demonstrated clinical benefit with periodic injections of onabotulinum toxin, but the mechanism of action is unknown.

蛋白质精氨酸甲基转移酶1在肿瘤发生发展中作用的研究进展北大核心

蛋白质精氨酸甲基转移酶1(protein arginine methyltransferase 1,PRMT1)是主要的Ⅰ型精氨酸甲基转移酶,催化一甲基化和不对称二甲基化,其底物被甲基化后参与细胞生物学过程。研究表明,PRMT1在多种恶性肿瘤中异常表达,促进肿瘤细胞的增殖、侵袭和迁移,调控人类多种肿瘤发生发展过程,揭示PRMT1可能成为肿瘤治疗中潜在的生物标志物或靶点。本文对PRMT1的结构、底物、生物学功能、及其在肿瘤发生发展中的作用进行总结,旨在为今后研究PRMT1相关肿瘤提供参考。     

欧前胡素抗肿瘤作用机制及治疗的研究进展

欧前胡素是从中药当归中提取的呋喃香豆素类化合物,临床上常用于治疗头痛、炎症、心血管疾病等。近年来研究发现,欧前胡素对多种类型的肿瘤细胞增殖均有抑制作用,能发挥抗肿瘤的功效。本文就欧前胡素对肿瘤及相关疾病的治疗作用和机制进行探讨,以期从不同的角度为肿瘤治疗提供新思路、新方法,并对欧前胡素的进一步研究和开发利用提供理论基础。     

Spatial Filtering of Electroencephalography Reduces Artifacts and Enhances Signals Related to Spinal Cord Stimulation (SCS)

ObjectivesHow spinal cord stimulation (SCS) in its different modes suppresses pain is poorly understood. Mechanisms of action may reside locally in the spinal cord, but also involve a larger network including subcortical and cortical brain structures. Tonic, burst, and high-frequency modes of SCS can, in principle, entrain distinct temporal activity patterns in this network, but finally have to yield specific effects on pain suppression. Here, we employ high-density electroencephalography (EEG) and recently developed spatial filtering techniques to reduce SCS artifacts and to enhance EEG signals specifically related to neuromodulation by SCS.Materials and MethodsWe recorded high-density resting-state EEGs in patients suffering from pain of various etiologies under different modes of SCS. We established a pipeline for the robust spectral analysis of oscillatory brain activity during SCS, which includes spatial filtering for attenuation of pulse artifacts and enhancement of brain activity potentially modulated by SCS.ResultsIn sensor regions responsive to SCS, neuromodulation strongly reduced activity in the theta and low alpha range (6–10 Hz) in all SCS modes. Results were consistent in all patients, and in accordance with thalamocortical dysrhythmia hypothesis of pain. Only in the tonic mode showing paresthesia as side effect, SCS also consistently and strongly reduced high-gamma activity (>84 Hz).ConclusionsEEG spectral analysis combined with spatial filtering allows for a spatially and temporally specific assessment of SCS-related, neuromodulatory EEG activity, and may help to disentangle therapeutic and side effects of SCS.     

单味中药降尿酸作用机制概述※

降尿酸是治疗痛风和高尿酸血症的基本方法，目前降尿酸作用途径主要是通过抑制黄嘌呤氧化酶、腺苷脱氨酶等合成酶的活性，或（且）影响肾脏尿酸转运蛋白（OAT1、OAT3、URAT1、GLUT9）等的表达，进而降低尿酸的水平。由于中药治疗高尿酸血症及痛风的作用机制尚不明确，因此本文通过检索中国知网、维普、万方、pubMed、Embase等数据库，对相关文献进行筛选，总结了具有明确降尿酸作用机制的单味中药，并进行功效归类，有助于对其作用机制进一步研究，为防治痛风和高尿酸血症提供更可靠、更安全的中医治疗依据。     

Cholinergic hyperactivity in patients with myasthenia gravis with MuSK antibodies: A neurophysiological study

ObjectivePatients with myasthenia gravis associated with muscle-specific tyrosine kinase antibodies (MuSK-MG) often manifest signs of cholinergic hyperactivity with standard doses of acetylcholinesterase inhibitors (AChE-Is). Aim of the study was to investigate whether repetitive compound muscle action potential (R-CMAP), the neurophysiological correlate of cholinergic hyperactivity, was present in MuSK-MG irrespective of AChE-I treatment.MethodsPatients with confirmed diagnosis of MuSK-MG were consecutively enrolled during follow-up visits, from January 2019 to April 2020. All these subjects underwent the same neurophysiological protocol, including motor nerve conduction studies and repetitive nerve stimulation. In patients taking pyridostigmine, neurophysiological testing was performed at least 12 hours after the last dose. For comparison, the presence of R-CMAP was investigated in 20 consecutive acetylcholine receptor antibody positive myasthenia gravis (AChR-MG) patients.ResultsWe enrolled 25 MuSK-MG patients (20 females), aged 16–79 years at the study time, with disease duration ranging 0.6–48.8 years (median: 17.7 years). R-CMAP was detected in 12/25 (48%) MuSK-MG cases and in none of the AChR-MG controls (p = 0.0003). In the MuSK-MG population, a history of muscle cramps and fasciculations, during low-dose pyridostigmine therapy, was significantly more frequent in R-CMAP positive than in R-CMAP negative patients (100% vs 31%, p = 0.001). At the time of the study, the proportion of patients still symptomatic for MG was higher among R-CMAP positive cases (92% vs 23%, p = 0.0005).ConclusionsCholinergic hyperactivity is a relatively common finding in MuSK-MG patients, independent of AChE-I treatment, and may constitute an intrinsic feature of the disease.SignificanceR-CMAP detection can represent a useful diagnostic clue for MuSK-MG and predicts poor tolerance to AChE-Is.     

基于网络药理学和分子对接技术研究黄芪-赤芍治疗COPD的作用机制＊

目的 基于网络药理学和分子对接技术探究黄芪-赤芍配伍对治疗慢性阻塞性肺疾病（chronic obstructive pulmonary disease，COPD）的作用机制。方法 利用TCMSP，Pharmmaper数据库，筛选黄芪-赤芍治疗COPD的活性成分和潜在靶点；结合Genecards数据库挖掘的COPD相关靶点，对黄芪-赤芍药对与COPD靶点进行PPI网络构建，交互处理得到黄芪-赤芍药对治疗COPD的关键靶点，并进行GO分析和KEGG通路富集分析；并采用分子对接技术将主要活性成分与TNF-α（肿瘤坏死因子），IL-6（白细胞介素6）等进行分子对接；最后利用A549炎症细胞与人脐静脉内皮细胞缺氧损伤模型进行体外细胞实验对结果加以验证。结果 黄芪-赤芍药对中44个有效成分作用于COPD，核心成分为：槲皮素、山奈酚、丁子香萜、芍药苷、（2R，3R）-4-methoxyl-distylin、二氢异黄酮；黄芪-赤芍药对通过IL6、PTGS2、TNF等113个靶蛋白，调控Ras、PI3KAkt、IL-17等多条信号通路治疗COPD，且分子对接结果显示槲皮素、山奈酚、丁子香萜、芍药苷与IL-6、PTGS2、TNF大分子蛋白有良好的结合性，体外细胞试验证实，槲皮素与山奈酚均能减少IL-8，MMP-9炎症因子的分泌，具有不同程度的抗炎效果；芍药苷有明显的扩血管、抗血栓之效。结论 黄芪-赤芍药对治疗COPD具有多成分、多靶点、多通路、整体调节的作用特点。初步揭示了黄芪-赤芍药对通过抑制炎症反应、调节上皮细胞生长增强保护屏障等预测出黄芪-赤芍药对治疗COPD的潜在作用机制，以期为其活性成分的药效物质基础提供理论研究和思路。