涡虫神经再生与原始脑构建初探

利用石蜡切片、乙酰胆碱酯酶组织化学定位和切割再生实验方法,研究两类涡虫的神经结构,发现AChE 的神经结构在HE染色中,脑周围有许多形态不同的细胞,脑中部组织充满胶质的纤维状结构,几乎不存在典型的细胞.提出涡虫的再生能力与其生殖方式密切相关.对原始脑构建提出新看法,认为脑构建的起源,首先是形成类神经物质,然后是多功能的类神经细胞,之后形成了原始的神经网,进一步分化为神经索.为了功能上的沟通和协调,神经索前端分化、发育、膨大成神经节,同时膨大部位相互接近,发出突触互相联系,协调身体左右边活动、捕食、感觉和反应,形成所谓的“脑”,即脑神经节.     

Ag+‐Gated Surface Chemistry of Gold Nanoparticles and Colorimetric Detection of Acetylcholinesterase

Chemical regulation of enzyme‐mimic activity of nanomaterials is challenging because it requires a precise understanding of the surface chemistry and mechanism, and rationally designed applications. Herein, Ag⁺‐gated peroxidase activity is demonstrated by successfully modulating surface chemistry of cetyltrimethylammonium bromide‐capped gold nanoparticles (CTAB‐AuNPs). A surface blocking effect of long‐chain molecules on surfaces of AuNPs that inhibit peroxidase activity of AuNPs is found. Ag⁺ ions can selectively bind on the surfaces of AuNPs and competitively destroy CTAB membrane forming Ag⁺@CTAB‐AuNPs complexes to result in enhanced peroxidase activity. Ag⁺@CTAB‐AuNPs show the highest peroxidase activity compared to similar‐sized citrate‐capped and ascorbic acid‐capped AuNPs. Ag⁺@CTAB‐AuNPs can potentially develop into analyte‐responsive systems and exhibit advantages in the optical sensing field. For example, the Ag⁺@CTAB‐AuNPs system shows an enhanced sensitivity and selectivity for acetylcholinesterase activity sensing compared to other methods.     

Disorders of the Cholinergic System in COVID-19 Era—A Review of the Latest Research

The appearance of the SARS-CoV-2 virus initiated many studies on the effects of the virus on the human body. So far, its negative influence on the functioning of many morphological and physiological units, including the nervous system, has been demonstrated. Consequently, research has been conducted on the changes that SARS-CoV-2 may cause in the cholinergic system. The aim of this study is to review the latest research from the years 2020/2021 regarding disorders in the cholinergic system caused by the SARS-CoV-2 virus. As a result of the research, it was found that the presence of the COVID-19 virus disrupts the activity of the cholinergic system, for example, causing the development of myasthenia gravis or a change in acetylcholine activity. The SARS-CoV-2 spike protein has a sequence similar to neurotoxins, capable of binding nicotinic acetylcholine receptors (nAChR). This may be proof that SARS-CoV-2 can bind nAChR. Nicotine and caffeine have similar structures to antiviral drugs, capable of binding angiotensin-converting enzyme 2 (ACE 2) epitopes that are recognized by SARS-CoV-2, with the potential to inhibit the formation of the ACE 2/SARS-CoV-2 complex. The blocking is enhanced when nicotine and caffeine are used together with antiviral drugs. This is proof that nAChR agonists can be used along with antiviral drugs in COVID-19 therapy. As a result, it is possible to develop COVID-19 therapies that use these compounds to reduce cytokine production. Another promising therapy is non-invasive stimulation of the vagus nerve, which soothes the body’s cytokine storm. Research on the influence of COVID-19 on the cholinergic system is an area that should continue to be developed as there is a need for further research. It can be firmly stated that COVID-19 causes a dysregulation of the cholinergic system, which leads to a need for further research, because there are many promising therapies that will prevent the SARS-CoV-2 virus from binding to the nicotinic receptor. There is a need for further research, both in vitro and in vivo. It should be noted that in the functioning of the cholinergic system and its connection with the activity of the COVID-19 virus, there might be many promising dependencies and solutions.     

野生和种植藜蒿不同部位提取物的抗氧化活性和酶抑制活性

藜蒿为江西特色食物资源,其嫩茎常被加工成美食,而叶和根被作废弃物直接丢弃。本研究比较了野生藜蒿叶、茎和根及种植藜蒿叶、茎的总酚和总黄酮含量以及提取物的抗氧化、α-葡萄糖苷酶、黄嘌呤氧化酶和乙酰胆碱脂酶活性抑制能力,旨在为藜蒿副产物的高值化利用提供参考。结果表明,野生和种植藜蒿叶分别含有最高的总酚含量(30.12 mg GAE/g DM)和总黄酮含量(0.63 mg QuE/g DM)。野生藜蒿叶提取物的DPPH·清除能力、ABTS^+·清除能力和乙酰胆碱酯酶抑制能力最强,其IC50值分别为0.37,0.39 mg DM/mL和10.06 mg DM/mL。野生藜蒿根提取物的α-葡萄糖苷酶和黄嘌呤氧化酶活性抑制能力最强,其IC50值分别为14.08 mg DM/mL和4.01 mg DM/mL,其次为野生藜蒿叶。相关性分析表明,酚类化合物是藜蒿中最主要的抗氧化活性成分。相比于种植藜蒿和野生藜蒿茎,野生藜蒿叶是天然抗氧剂、α-葡萄糖苷酶抑制剂、黄嘌呤氧化酶抑制剂和乙酰胆碱酯酶抑制剂的更优质的原料来源,具有进一步研究其抗糖尿病、高尿酸血症和老年痴呆症的价值。     

Immobilization of glucose oxidase and acetylcholinesterase onto modified polyamide sorbent

Two types of polyamide (PA) sorbents with high specific area were prepared. The effects of solvent type, concentrations of formic acid, and polymer on the porosity characteristics were studied. The sorbent with the highest specific area was obtained by using C₂H₅OH—HCOOH solvent (60% HCOOH) and the rest of the experiments were carried out with this type of sorbent. The possibility of applying the PA sorbent as carrier for immobilization of glucose oxidase (GOD) and acetylcholinesterase (AChE) was investigated. In order to increase the active groups content (necessary for enzyme immobilization), the sorbent was modified with dimethylaminoethylmethacrylate (DMAEM) and 2-acrylamido-2-methylpropensulfonic acid. The amount of the active groups introduced during the modification and the degree of hydrophilicity were determined. The quantity of bound protein and relative activity of GOD and AChE immobilized onto unmodified and modified sorbents were studied. Optimum pH and temperature of the immobilized GOD and AChE were also determined. The influence of three phosphoroorganic compounds on the activity of the immobilized AChE was investigated. Tetrachlorvinvos was found to be the strongest inhibitor, while AChE immobilized onto PA sorbent modified with DMAEM showed the highest stability. The possibility of using immobilized GOD and AChE in a flow-injection system for determination of the concentrations of glucose and phosphoroorganic compounds was studied. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68:323–329, 1998     

Acetylcholinesterase inhibitors, neuropsychiatric symptoms, and Alzheimer's disease subtypes: An alternate hypothesis to global cognitive enhancement.

Cholinergic neurons are extensively implicated in cognitive functioning. Cholinergic deficiency is a widely accepted hypothesis of cognitive decline in Alzheimer's disease (AD) and is the impetus for the development of cholinesterase inhibitors (ChIs). Studies on the efficacy of ChIs emphasize global cognitive improvement and the amelioration of neuropsychiatric symptoms associated with AD. The authors propose that the current perception of ChIs as global cognitive enhancers may be misleading. It is hypothesized that these drugs improve cognition in specific AD subtypes primarily through psychotropic properties that facilitate attentional processing. In effect, increased attentional capacity through diminished neuropsychiatric symptoms serves to augment results on global cognitive measures: in particular, AD subtypes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

人参皂苷Rg1脂质体对东莨菪碱诱导大鼠学习记忆障碍的改善及其作用机制

目的: 观察人参皂苷Rg1脂质体(Rg1-L)对东莨菪碱诱导大鼠学习记忆障碍的改善,并探讨其相关机制。方法: 制备东莨菪碱诱导大鼠学习记忆障碍模型,采用Y型迷宫评价Rg1-L对模型大鼠学习记忆的影响,并测定大鼠大脑皮质中乙酰胆碱酯酶活性。结果: Rg1-L可以显著改善模型大鼠学习记忆功能,同时抑制大脑皮质中乙酰胆碱酯酶活性。结论: Rg1-L对东莨菪碱诱导大鼠学习记忆障碍模型大鼠的学习记忆功能有显著的改善作用,其机制可能与抑制大脑皮质中乙酰胆碱酯酶活性、提高人参皂苷Rg1生物利用度有关。     

Vectorially Imprinted Hybrid Nanofilm for Acetylcholinesterase Recognition

Effective recognition of enzymatically active tetrameric acetylcholinesterase (AChE) is accomplished by a hybrid nanofilm composed of a propidium‐terminated self‐assembled monolayer (Prop‐SAM) which binds AChE via its peripheral anionic site (PAS) and an ultrathin electrosynthesized molecularly imprinted polymer (MIP) cover layer of a novel carboxylate‐modified derivative of 3,4‐propylenedioxythiophene. The rebinding of the AChE to the MIP/Prop‐SAM nanofilm covered electrode is detected by measuring in situ the enzymatic activity. The oxidative current of the released thiocholine is dependent on the AChE concentration from ≈0.04 × 10^?6 to 0.4 × 10^?6m . An imprinting factor of 9.9 is obtained for the hybrid MIP, which is among the best values reported for protein imprinting. The dissociation constant characterizing the strength of the MIP‐AChE binding is 4.2 × 10^?7m indicating the dominant role of the PAS‐Prop‐SAM interaction, while the benefit of the MIP nanofilm covering the Prop‐SAM layer is the effective suppression of the cross‐reactivity toward competing proteins as compared with the Prop‐SAM. The threefold selectivity gain provided by i) the “shape‐specific” MIP filter, ii) the propidium‐SAM, iii) signal generation only by the AChE bound to the nanofilm shows promise for assessing AChE activity levels in cerebrospinal fluid.     

仿刺参共附生真菌Aspergillus terreus来源的聚酮类化合物的研究

海参是海洋中重要的食物和药物资源,含有丰富的活性物质。海参共附生微生物非常丰富。为了从海参共附生微生物获得具有强生物活性的物质,对山东芝罘岛海域的仿刺参来源的共附生真菌Aspergillus terreus利用分子生物学手段进行了种属鉴定,并利用固体基进行培养,对其次级代谢产物进行了研究。通过薄层层析、柱层析、高效液相色谱对其化学成分进行了分离和纯化,综合核磁波谱、质谱对其进行结构鉴定。从该菌中获得dihydrogeodin(1)、Territrems A(2)、Territrems B(3)、2,4-二羟基苯乙酮(4)、questin(5)和emodin(6)六种物质。利用人口腔上皮癌细胞株(KB)和多药耐药性的细胞株(KBv200)对1,5和6进行了细胞毒活性测试。本研究首次对化合物1进行了完整的谱图解析,并首次发现海洋环境来源的微生物可以代谢化合物dihydrogeodin(1),以及具有强抑制乙酰胆碱酶活性Territrems(3),而这些物质是海参本体不能够产生的,为开发具有预防和治疗帕金森病相关的功能食品提供了新来源。