变异白色红花总黄酮提取物安全性毒理学评价

本文通过急性毒性试验、三项遗传毒性试验和30 d喂养试验,对变异白色红花总黄酮提取物(TFES)进行安全性毒理评价。结果表明,TFES对小鼠急性毒性试验,LD5010.0 g/kg·BW,按急性毒性剂量分级,属实际无毒物质;三项遗传毒性试验即Ames试验、小鼠骨髓嗜多染红细胞微核试验、小鼠精子畸形试验结果均为阴性;TFES对大鼠30 d喂养试验,动物未见明显的中毒症状和死亡,TFES各剂量组大鼠体重、总食物利用率、血清生化指标、血液学指标、脏器系数指标以及病理组织学等指标与对照组比较,无显著性差异。TFES在本实验条件下,未观察到明显毒性作用,为其进一步开发应用提供了安全依据。     

桑色素对小鼠的急性毒性研究

桑色素是一种天然的黄酮类化合物,具有抗炎、抗肿瘤及抗氧化等作用,本实验中使用上下法主试验,腹腔注射给予ICR雌雄小鼠不同剂量的桑色素(230、280、330、390、450、530、630 mg/kg),观察动物的毒性反应,存活动物观察14 d,计算半数致死量LD50。观察期结束后,通过体重、外周血指标、血清生化指标和病理组织学检查来衡量桑色素对小鼠的急性毒性。研究发现,高剂量桑色素对小鼠有一定的急性毒性,腹腔注射半数致死量LD50为463.24 mg/kg,并且毒性强弱与给药剂量密切相关。     

热感赛比斯坦颗粒毒理学实验研究

观察热感赛比斯坦颗粒对小鼠的急性和大鼠长期毒性反应。将热感赛比斯坦颗粒生药浸膏液干燥,粉碎,以最大浓度及小鼠最大给药体积对小鼠灌胃,进行最大耐受量试验,观察两周之内出现的急性毒性反应。采用SD大鼠分别给予37.50 g/(kg·d)、12.50 g/(kg·d)、3.75 g/(kg·d)药物灌胃,空白组给予同等体积的蒸馏水,进行长期毒性试验。在给药30 d、停药15 d测定生化、血象指标、脏器系数和各主要脏器病理切片。急性毒性试验测得小鼠最大耐受量为299.70 g/kg,无死亡现象,解剖后发现小鼠各主要脏器无肉眼可见病变。长期毒性试验给药及恢复期间各组大鼠体重无统计学差异。血液学、血生化及脏器系数检查,给药组与对照组之间个别指标有差异,无毒性意义。主要脏器的病理组织学检查,未见明显病理改变。本研究证明热感赛比斯坦颗粒临床成人拟用给药剂量远低于其毒性剂量,安全性良好。     

犬传染性肝炎DNA疫苗安全性评价

目的研究犬传染性肝炎核酸疫苗pVAX1-CpG-Loop的安全性。方法 BALB/c小鼠随机分为4组,高剂量组(肌内注射每只200μg)、低剂量组(肌内注射每只100μg)、联合免疫组(肌内注射每只100μg,皮下注射50μg,滴鼻每只50μg)和PBS组,每两周免疫1次,共免疫3次。末次免疫后4周、6个月检测血常规和血液生化及对F1代的影响,用PCR和RT-PCR的方法检测DNA疫苗的生物学分布和存留时间,末次免疫后4周和6个月取脏器观察病理损伤。结果各剂量组的主要血液学检测指标、对F1代的影响差异无显著性。末次免疫后4周各剂量组AST明显高于对照组。DNA疫苗在注射部位可存留8周,其中高剂量组和低剂量组在肝、脾、肾和注射部位有分布,联合免疫组在肺组织也有分布。末次免疫后4周小鼠肝肾有淋巴细胞浸润,6个月后慢性炎症明显好转。结论由犬传染性肝炎病毒DNA疫苗引起的肝肾损伤是一过性的,并且pVAX1-CpG-Loop没有整合到宿主基因组,也没有传递给F1代。     

低聚肽和VC复合固体饮料的安全性毒理学评价

为了评价低聚肽和维生素C复合固体饮料作为功能性食品食用的毒理学安全性,根据我国卫生部《保健食品检验与评价技术规范》(2003)进行安全性毒理学研究。研究结果表明:低聚肽和维生素C复合固体饮料对小鼠急性经口最大耐受剂量大于20 g/kg BW,根据急性毒性分级标准规定,属无毒级;遗传毒性试验(Ames试验、小鼠骨髓细胞微核试验、小鼠精子畸形试验)结果为阴性;30天喂养试验表明,按人体推荐量的25、50和100倍即2.1 g/kg、4.2 g/kg、8.3 g/kg为低、中、高剂量时,各剂量组动物生长发育良好,大鼠体重、增重、食物利用率、脏器重量、脏/体比、血液学指标及血生化指标与对照组比较均无显著性差异(P0.05);大体解剖和组织病理学检查未见与样品有关的异常改变。通过以上的试验结果可以判定低聚肽和维生素C复合固体饮料具有较好的食用安全性。     

薏米黄酒的急性毒性研究

目的：研究薏米黄酒的急性毒性,评价该酒的食用安全性。方法：以ICR小鼠为受试对象,一次性给予最大剂量,观察薏米黄酒对小鼠的急性毒性反应,测定薏米黄酒的LD50和最大耐受剂量。结果：小鼠无一只死亡,无法测出LD50,最大耐受量大于20400 mg/kg。结论：实验检测表明,该黄酒无毒,为薏米黄酒的应用提供了毒理学依据。     

薏米黄酒的急性毒性研究

目的:研究薏米黄酒的急性毒性,评价该酒的食用安全性。方法:以ICR小鼠为受试对象,一次性给予最大剂量,观察薏米黄酒对小鼠的急性毒性反应,测定薏米黄酒的LD50和最大耐受剂量。结果:小鼠无一只死亡,无法测出LD50,最大耐受量大于20400 mg/kg。结论:实验检测表明,该黄酒无毒,为薏米黄酒的应用提供了毒理学依据。     

四种不同方法注射眼镜蛇蛇毒对小鼠LD_(50)的影响分析

目的比较小鼠经不同途径注射眼镜蛇蛇毒的半数致死量(LD_(50)),并观察中毒症状。方法将小鼠分别经四种途径注射眼镜蛇毒冻干粉溶液,并根据各组小鼠死亡情况,运用Bliss软件测定LD_(50)估计值、置信区间等。观察各组小鼠生物学行为及死亡情况,并对死亡小鼠和存活小鼠进行解剖分析。结果小鼠经静脉、腹腔、肌肉和皮下注射眼镜蛇蛇毒的LD_(50)分别为0.691 mg/kg、0.741 mg/kg、0.803 mg/kg和0.915 mg/kg,95%CI分别为0.634～0.742 mg/kg、0.676～0.792 mg/kg、0.754～0.856 mg/kg和0.851～1.05 mg/kg。各组小鼠中毒症状明显,表现为呼吸困难、精神萎靡、眼球昏暗、眼角有分泌物、身体出现扭体抽搐等反应,均在2～9 h内死亡。结论小鼠经静脉注射眼镜蛇毒溶液中毒的毒性剂量最小,皮下注射眼镜蛇毒溶液中毒的毒性剂量最大。小鼠经四种不同途径注射眼镜蛇蛇毒的LD_(50)的值按从大到小的排序为皮下注射,肌肉注射,腹腔注射,静脉注射。     

汉坦病毒核酸疫苗在小鼠体内表达分布的初步研究

运用生物荧光技术,肌肉免疫接种小鼠含汉坦病毒S抗原基因片段的核酸疫苗,观察重组核酸疫苗在其体内的表达分布。进一步探讨汉坦病毒核酸疫苗的应用前景。扩增纯化已构建好的含有汉坦病毒S抗原基因片段和绿色荧光蛋白(GFP)基因的重组质粒pEGFP/S;免疫接种小鼠胫前肌,观察pEGFP/S在小鼠体内的表达分布。免疫接种3 d后在实验组小鼠肝、肾、脾、肌肉各组织均检测到较强的绿色荧光。重组质粒pEGFP/S能在小鼠的多个组织器官表达,为深入研究汉坦病毒核蛋白和有效的核酸疫苗奠定了基础。     

复合生物杀菌剂F6-11的安全性毒理学研究

目的：为研究复合生物杀菌剂F6．11毒性,采用动物实验法进行毒理学评价。方法：对复合生物杀菌剂F6-11进行小鼠急性毒性试验、小鼠骨髓嗜多染红细胞微核试验、亚急性毒性试验、家兔多次完整皮肤刺激试验、急性眼刺激试验、豚鼠皮肤变态反应试验、鱼类延长毒性14天试验。结果：复合生物杀菌剂F6—11对小鼠急性毒性LD50〉5000mg／kg．bw,属于实际无毒级物质;小鼠微核试验该杀菌剂各剂量组与阴性对照组比较,微核率无显著性差异（P〉0．05）;亚急性毒性试验动物血常规、生化指标及各脏器均未发现异常;对家兔多次完整皮肤及眼刺激反应积分均为0,均属无刺激性;对豚鼠皮肤变态反应试验组动物与阴性对照组无可见不同．试验组动物皮肤致敏反应积分为0,无致敏作用;鱼类延长毒性14天试验无异常。结论：毒理学研究表明,复合生物杀菌剂F6．11具有良好的使用安全性。     

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.     

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     

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.     

鸡传染性法氏囊病病毒研究进展

传染性法氏囊病(Infection bursal disease, IBD)是由鸡传染性法氏囊病毒(Infectious bursal disease virus, IBDV)引起的鸡和火鸡的一种高度接触性传染病,给世界各国的禽养殖业带来了巨大损失.自IBDV发现至今新的变异株不断出现,分子结构的改变导致病毒致病力的改变及宿主对疫苗应答的改变,使得传统的疫苗已不能控制其流行,因此各国学者对其基因组结构和功能进行了广泛深入的研究,并积极研制新型有效的疫苗以达到防治的目的.     

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.     

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).     

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.