花生四烯乙醇胺的研究进展

花生四烯乙醇胺（arachidonoylethanolamide, anandamide，ANA）是近年来确定的大麻素受体的内源性配基，它主要分布在中枢神经系统、免疫系统及子宫等部位，具有大麻的主要活性成分——Δ⁹-四氢大麻酚（Δ⁹-THC）的药理功能.ANA有两种受体，即脑型受体（CB1）和脾型受体（CB2），它们都是与GTP偶联的跨膜受体，是ANA发挥作用的主要途径.脂肪酸酰胺水解酶（fatty acid amide hydrolase，FAAH）是ANA特异性极高的水解酶，它可以迅速调节ANA在体内的含量，从而发挥特异的生理作用.     

内源性大麻系统

大麻是当前西方社会服用人数最多的滥用药,其有效成分为△~9－四氢大麻醇。由于脂溶性高,以往认为其作用系改变神经细胞膜磷脂双层的物化性质。后来找到了一些（人工）合成（的）化合物作用更强,但水溶性增加;用它们作为配体证明有受体存在,并已克隆。CB1受体在脑组织,CB2受体在免疫组织,均系G－蛋白偶合型。根据药物→受体→内源性配体的规律,又找到了大麻受体的内源性配体花生四烯酸乙醇胺。至此证明体内存在着内源性大麻系统,使该领域的研究迈进到一崭新的时期。     

新型靶向化合物——植物大麻素的生物合成途径及 研究进展

植物大麻素是具有生物活性的一系列萜类化合物的总称,被认为是大麻的专有成分。具有主要药理活性的植物大麻素为Δ~9-四氢大麻酚(Δ~9-tetrahydrocannabinol,Δ~9-THC)和大麻二酚(Cannabidiol,CBD),均以内源性大麻素受体为靶点,通过激活内源性大麻素系统而参与人体许多生理病理过程,具有广泛的治疗潜力。目前,Δ~9-THC、CBD及其类似物或组合制剂,已用于治疗癫痫、癌症化疗患者的呕吐、多发性硬化症痉挛和缓解神经性疼痛以及晚期癌症患者的疼痛。随着对Δ~9-THC和CBD应用价值的深度发掘和药用标准化制剂需求量增加,Δ~9-THC和CBD在制药工业中实现规模化生产迫在眉睫。通过综述近年来植物大麻素的药理学研究进展,植物大麻素生物合成途径和关键酶的作用机制以及制药工业中植物大麻素的生产策略,旨在探索利用合成生物学技术解决植物大麻素药源问题的潜力,为合成大麻素的微生物工程研发提供理论基础,促进药用大麻素的规模化生产。     

大麻和大麻受体与免疫应答

大麻类物质通过与免疫细胞表面抑制性G蛋白偶联受体CB1和CB2结合 ,调节免疫细胞的功能和细胞因子的产生。大麻受体可根据组织分布不同分为中枢型和外周型两类 ,前者主要分布在脑组织中而后者主要分布在免疫细胞表面。绝大多数大麻类物质具有结合两种类型受体的能力 ,而且内源性大麻可以快速通过血脑屏障 ,提示其可能是神经 免疫轴中的活跃递质。     

大麻素受体系统对视网膜细胞离子通道和突触传递的调控

内源性大麻素系统在脊椎动物视网膜中广泛分布。大麻素受体(cannbinoid receptor)主要有CB1和CB2两个亚型,与内源性配体N-花生四烯酸氨基乙醇(N-arachidonoylethanolamide,anandamine,AEA)和2-花生四烯酸甘油(2-arachidonyl glycerol,2-AG)结合调控视网膜神经元和胶质细胞的功能,从而参与调控视网膜视觉信息的处理。本文结合我们研究组近年在视网膜大麻素受体系统的研究结果,综述了有关大麻素CB1和CB2受体对视网膜细胞离子通道和突触传递调控及其机制的研究进展。     

大麻素受体在胃肠运动调节中的作用

七次跨膜G蛋白偶联的大麻素受体至少有CB1和CB2两种亚型.尽管两种CB受体在胃肠道的分布不尽相同,但多数分布于肠神经系统.CB1受体激活可通过神经机制抑制瞬时下食管括约肌松弛,抑制小肠收缩和蠕动,减慢胃肠运动.CB2可能与一些特殊病理生理条件下胃肠运动的调节有关.这些结果提示CB特别是CB1受体在胃肠运动调节中的作用.     

类大麻酚(cannabinoid)受体在脑中被定位

最近证明,Δ~9-四氯大麻酚(大麻的有效成份)及合成的类大麻酚的精神效应是介导的受体所致。Herkenham等用新鲜脑切片的放射自显影技术(把切片与放射性[~3H]类大麻酚CP 55940温孵),定位脑中的类大麻酚受体。用这种技术检查所有种属包括人类的脑,发现在基底神经节、大脑皮质、海马及小脑中有大量受体。在脑干及脊髓中存在很少的受体。     

不同储存条件对大麻化学稳定性的影响

为探讨光照和温度对大麻植物中大麻酚类稳定性的影响,该研究将大麻植物检材以固体粉末和甲醇提取溶液的形式分别在室温(22±2)℃见光、室温(22±2)℃避光、4℃避光、-20℃避光条件下储存20 d后,采用超高效液相(UPLC-PDA)检测分析样本中Δ9-四氢大麻酚(Δ9-THC)、大麻二酚(CBD)和大麻酚(CBN)的含量变化情况。结果表明:3种大麻酚类在不同化学表型大麻中的含量变化趋势相同,固体粉末样本的Δ9-THC、CBD含量在室温光照条件下显著下降,CBN含量基本不变;甲醇提取样本中Δ9-THC、CBN和CBD含量在室温光照条件下均显著下降。避光条件下的室温(22±2)℃及低温(4℃、-20℃)可稳定保存两种形式的大麻样本。大麻中的精神活性成分Δ9-THC的降解满足一级反应动力学规律,光照是影响Δ9-THC降解的重要因素,如果在室温避光条件下储存,大麻或其甲醇提取物可稳定保存,可以更好地指导司法实践活动中短期内大麻检材的取证、运送、保存及鉴定。     

大麻及其类似物对动物生殖的影响及其作用机制

大麻是当前社会服用人数最多的毒品,其最有生理活性的成分是（－）－四氢大麻醇。大麻对乳动物生殖功能有一定的生物学作用。在雄性动物中直接抑制精子功能、减少性激素的分泌、阻精子的顶体反应等。在雌性动物中,大麻作用依赖于大麻水平和胚胎发育所处阶段的不同而不同。低浓度的大麻对胚胎发育和着麻有抑制作用,与子宫对胚胎着床的非接受性有关。大麻在生殖系统中的作用主要是通过CB1－R来实现的。     

食物气味如何让人食欲大增

<正>食物的香味为何让你食欲大增?《自然-神经科学》上的一项研究找到了原因——大脑嗅球中1型大麻素(CB1)受体的存在。这项研究还发现CB1受体的激活可以加强气味感知从而促进食物摄取,研究人员同时认为这些受体为改变导致肥胖的进食行为提供了一个潜在的药理学靶向。短时间的节食行为被认为可以增加哺乳动物大脑中内源性大麻素的水平浓度。饥饿也被认为可以增强我们对     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.