蕨麻多糖对小鼠脾淋巴细胞上清液IFN-γ和可溶性LAG-3分子水平的影响

为了观察蕨麻多糖对急性低剂量镉染毒小鼠脾淋巴细胞上清液中IFN-γ和可溶性LAG-3(soluble LAG-3,s LAG-3)分子水平的影响。将试验小鼠一次性腹腔注射氯化镉溶液(1 mg/kg)染毒,观察24h即造模成功后,腹腔注射低、中、高剂量蕨麻多糖治疗一周,于实验终末测各组小鼠脾脏、胸腺指数,ELISA法测IFN-γ、s LAG-3含量;免疫荧光法观察CD3+、CD4+、CD8+T淋巴细胞。结果表明蕨麻多糖低、中、高剂量组中,IFN-γ、s LAG-3的含量较空白对照组和单纯镉染阳性对照组均增高,以高浓度组增高明显(P0.05);CD3+、CD4+T淋巴细胞较空白对照组和单纯镉染阳性对照组均增多,仍以高浓度组增多明显,CD8+T变化不显著。蕨麻多糖能促进急性低剂量镉染毒小鼠脾淋巴细胞分泌IFN-γ和s LAG-3,CD3+、CD4+T淋巴细胞亦相应增加。     

维生素E对2,3,7,8-四氯二苯并二噁英急性染毒小鼠卵巢内分泌及其结构的影响

为研究维生素E对2,3,7,8-四氯二苯并二噁英(TCDD)染毒小鼠生殖内分泌功能和卵巢的影响,设计了急性染毒实验。将24只4-5周龄的健康雌性小鼠(Mus musculus)随机分为对照组、TCDD(30μg/kg)染毒组和染毒同时给予100mg/kg维生素E组3组。通过放射免疫法测定小鼠血浆孕酮、雌二醇含量的变化,显微镜下计数卵泡数量并观察其形态变化。结果表明,TCDD能导致小鼠血浆孕酮含量的降低及卵巢结构的紊乱、卵泡数量的减少。100mg/kg的维生素E能明显对抗急性TCDD染毒引起的雌鼠孕酮含量和卵泡数量降低,缓解TCDD引起的小鼠卵巢形态结构的病变;TCDD染毒和维生素E对小鼠血浆雌二醇含量均没有明显影响。结果表明,维生素E对TCDD引起的内分泌功能紊乱以及卵泡数量降低有拮抗作用。     

双歧杆菌完整肽聚糖对食物过敏小鼠调节性T细胞影响的研究

目的以食物过敏小鼠为动物模型,通过灌喂双歧杆菌完整肽聚糖(Whole Peptidoglycan,WPG),观察其对调节性T细胞的作用。方法 4～6周龄SPF级无鸡蛋喂养BALB/c雌鼠随机分为3组,每组8只。取其中2组建立食物过敏模型,分别为OVA致敏阳性对照组、OVA激发后灌喂双歧杆菌WPG治疗组和生理盐水对照组。采用ELISA法检测各组血清中OVA特异性IgE、IL-10和TGF-β1水平;流式细胞术分析脾脏单个核细胞悬液中CD4+CD25+调节性T细胞的数量变化。结果 OVA组IL-10、TGF-β1水平显著高于对照组(P分别0.05和0.01);WPG组血清IL-10和TGF-β1水平显著低于OVA组(P0.05)。OVA组脾CD4+CD25+T淋巴细胞的百分比低于对照组(P0.05),WPG组与OVA组相比有升高趋势,差异有统计学意义(P0.05);OVA组脾Foxp3+CD4+CD25+调节性T细胞的百分比显著低于对照组(P0.01),WPG组与OVA组相比有升高趋势,差异有统计学意义(P0.01)。结论双歧杆菌WPG可以增加食物过敏小鼠CD4+CD25+调节性T细胞数量,刺激细胞因子IL-10和TGF-β分泌。     

十全育真汤对H22荷瘤小鼠免疫功能的影响

目的：研究十全育真汤对荷瘤小鼠免疫功能的影响,探讨十全育真汤抗肿瘤的作用机制。方法：SPF级雄性昆明种小鼠30只,制成荷H₂₂小鼠肝癌细胞移植瘤模型,随机分为模型组、阳性对照组及十全育真汤组（n=10）;另选择未接种小鼠10只为正常对照组。正常对照组、模型组每天按10 ml/kg灌胃生理盐水及蒸馏水,阳性对照组、十全育真汤组每天按8 g/kg、18 g/kg灌胃参一药液（80 mg/ml）与十全育真汤剂。连续给药14 d后处死小鼠,测量胸腺、脾脏指数及抑瘤率,检测外周血中白细胞、淋巴细胞含量及T细胞亚群CD3、CD4、CD8细胞百分比,血清中白细胞介素2（IL-2）、肿瘤坏死因子α（TNF-α）及干扰素-β（IFN-β）的含量,淋巴细胞增殖能力及NK细胞杀伤功能。结果：较正常对照组,十全育真汤组小鼠体重明显增加,脾脏指数显著增大（P<0.05）;白细胞、淋巴细胞CD4、CD8、CD3及TNF-α含量明显升高（P<0.05）;IL-2、IFN-β含量显著下降（P<0.05）;淋巴细胞增殖能力、NK细胞杀伤功能明显升高（P<0.05）。与模型组相比,十全育真汤组小鼠胸腺、脾脏指数显著增大（P<0.05）;白细胞、淋巴细胞CD3、CD4、IL-2、IFN-β及TNF-α含量明显升高（P<0.05）,CD8含量则显著降低（P<0.05）;NK细胞杀伤功能及淋巴细胞增殖能力显著增加（P<0.05）。结论：十全育真汤可促进H₂₂荷瘤小鼠免疫器官的生长,增强机体免疫功能,有利于肿瘤机体的恢复。     

京尼平对脓毒血症小鼠T细胞的免疫调节作用及其潜在机制

目的:探究京尼平对脓毒血症小鼠T细胞的免疫调节作用及其潜在机制。方法:小鼠盲肠结扎穿孔手术(CLP)后,分别在0h和24 h尾静脉注射1 mg/kg、2.5 mg/kg、5 mg/kg京尼平和磷酸盐缓冲液(PBS),连续7d观察和记录小鼠的死亡数。另取小鼠分为Sham组(n=8)、Genipin组(n=8)、CLP组(n=8)、Genipin+CLP组(n=14),Sham组注射PBS并实施假手术,Genipin组注射2.5 mg/kg京尼平并实施假手术,CLP组注射PBS并实施手术,Genipin+CLP组注射2.5 mg/kg京尼平并实施手术。CLP手术26 h后收集脾脏,检测脾脏淋巴细胞总数、CD4~+、CD8~+、细胞因子和凋亡蛋白FADD、caspase-3、caspase-8表达水平。结果:给药2.5 mg/kg的京尼平小鼠存活率高于其他小鼠。CLP组小鼠脾脏淋巴细胞总数、CD4~+、CD8~+、白介素(IL)-2、干扰素(IFN)-γ水平低于Sham组,CLP+Genipin组小鼠上述指标高于CLP组(P0.05);CLP组小鼠凋亡蛋白FADD、caspase-3、caspase-8表达、IL-4、IL-10水平高于Sham组,CLP+Genipin组小鼠上述指标低于CLP组(P0.05)。结论:京尼平能够通过抑制T细胞凋亡改善脓毒血症后期的免疫抑制,提高脓毒性小鼠的存活率。     

维生素E对2，3，7，8-四氯二苯并二嗯英急性染毒小鼠卵巢内分泌及其结构的影响

为研究维生素E对2,3,7,8-四氯二苯并二嗯英（TCDD）染毒小鼠生殖内分泌功能和卵巢的影响,设计了急性染毒实验。将24只4—5周龄的健康雌性小鼠（Musmusculus）随机分为对照组、TCDD（30ag／kg）染毒组和染毒同时给予100mg／kg维生素E组3组。通过放射免疫法测定小鼠血浆孕酮、雌二醇含量的变化,显微镜下计数卵泡数量并观察其形态变化。结果表明,TCDD能导致小鼠血浆孕酮含量的降低及卵巢结构的紊乱、卵泡数量的减少。100mg／kg的维生素E能明显对抗急性TCDD染毒引起的雌鼠孕酮含量和卵泡数量降低,缓解TCDD引起的小鼠卵巢形态结构的病变;TCDD染毒和维生素E对小鼠血浆雌二醇含量均没有明显影响。结果表明,维生素E对TCDD引起的内分泌功能紊乱以及卵泡数量降低有拮抗作用。     

高压氧对正常及SIRS大鼠脾T淋巴细胞的影响

本实验以SIRS为基础,以免疫功能和炎症反应中具有代表性的脾T淋巴细胞为研究对象,观察高压氧对正常机体以及SIRS状态机体的影响并探讨其可能的机制。健康雄性SD大鼠40只,体重约140~180 g,随机分为5组,每组8只。A组：腹腔注射生理盐水（5 mL/kg）;B组：腹腔注射等量生理盐水,做3次高压氧;C组：腹腔注射酵母多糖-石蜡悬液（500 mg/kg）;D组：腹腔注射酵母多糖-石蜡悬液（500 mg/kg）,做1次高压氧治疗;E组：腹腔注射酵母多糖-石蜡悬液（500 mg/kg）,做3次高压氧治疗。采用流式细胞仪计算大鼠脾脏淋巴细胞数量及比例。高压氧治疗（B组）降低正常大鼠外周血CD4＋T细胞百分比（P〈0.01）,对CD8＋T细胞无影响,因此CD4＋/CD8＋T细胞比值下降（P〈0.05）。酵母多糖腹腔注射（C组）使大鼠外周血CD4＋、CD8＋T细胞均减少（P〈0.01）,但CD4＋/CD8＋T细胞比值不变。1次和3次HBO治疗（D和E组）可使酵母多糖所致CD4＋T细胞减少（C组）明显恢复（P〈0.01,P〈0.05）,故CD3＋CD4＋/CD3＋CD8＋比值升高（P〈0.01,P〈0.05）,HBO几乎不影响CD8＋T细胞比例（P〉0.05）。酵母多糖导致大鼠脾脏CD4＋和CD8＋T细胞比例减少;高压氧可减少正常大鼠脾脏CD4＋T细胞比例,而增加SIRS脾脏的CD4＋T细胞比例,而对CD8＋T细胞无影响。     

芹菜多糖抑制小鼠肺癌的作用研究*

目的:探讨芹菜多糖抗肺癌的作用及机制。方法:提取纯化芹菜多糖,通过红外光谱和凝胶渗透色谱法对其进行鉴定;每只小鼠腹股沟皮下注射2×10⁷个Lewis肺癌细胞,建立肺癌C57BL/6小鼠模型,随机分为5组,每组10只。两天后,分别0、25、50、75、100 mg/kg芹菜多糖灌胃荷瘤小鼠10 d,流式和qPCR法分析小鼠外周血CD4⁺、CD8⁺淋巴细胞和脾淋巴细胞因子IL-2、IFN-γ与IL-4,并取肿瘤组织拍照和称重。结果:本实验所提取的芹菜多糖纯度为82%,鉴定为不均一的多糖,分子量为1.17×10³ kD;芹菜多糖灌胃小鼠可显著抑制肺癌的生长(P＜0.01),75 mg / kg治疗10 d后,可提高小鼠外周血CD4⁺和CD8⁺淋巴细胞的百分比(P ＜0.01),并明显增加50 mg / kg以上治疗组的脾淋巴细胞IL-2、IFN-γ和IL-4的转录水平(P ＜0.01)。结论:芹菜多糖可通过增强机体免疫,尤其是细胞免疫而发挥抗肺癌的作用。     

灵芝多糖GLP 抑制小鼠骨肉瘤细胞S-180 在体内生长的作用机制

目的:探讨灵芝多糖成分(GLP)抑制肿瘤的作用机制。方法:在小鼠右腋皮下接种1×106TC-1细胞后7天后,用100mg/kg、200mg/kg和400mg/kg 3种剂量给小鼠口服灌胃给药20天,然后观察肿瘤的重量,并用ELISA检测小鼠血清中IL-2、IL-6和TNF-alpha,用流式细胞仪检测其外周血中CD4+和CD8+。结果:100mg/kg、200mg/kg和400mg/kg 3种剂量给小鼠口服灌胃给药20天,与对照组比较,抑瘤率分别可以达到53%、59%和58%,P<0.05;小鼠外周血血清中的IL-2从1.27ng/mL提高到了2.88ng/mL,P<0.05;TNF-α从1.05ng/mL提高到了1.82ng/mL,P<0.05;而IL-6则没有明显的变化。CD4+细胞水平升高(从54.80%提高到了58.27%),但差异无统计学意义(P>0.05);CD8+细胞明显增多(从24.15%提高到了45.36%),差异有统计学意义(P<0.05)。结论:GLP有明显抑瘤作用,但抑瘤作用与GLP剂量不存在依赖关系。GLP对肿瘤细胞生长的抑制是通过提高小鼠的细胞免疫能力来实现,而并非直接杀伤肿瘤细胞。     

维生素E拮抗急性二(噁)英对小鼠肝脏细胞色素P450酶和抗氧化物酶基因转录的影响

为了探讨维生素E对急性2,3,7,8-四氯代二苯并二噁英（TCDD）染毒小鼠肝脏细胞色素P450酶（CYP450）基因和抗氧化物酶基因转录的影响,我们设计了对照组、TCDD（30μg／kg）染毒组和染毒同时给予100mg／kg维生素E组（实验组）3组实验。用Real—Time PCR法检测小鼠细胞色素P450酶1A1、1A2、181、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GSH-Px）基因表达的变化。结果显示：1）急性TCDD染毒小鼠肝脏细胞色素P450酶1A1、1A2、181mRNA水平与对照组相比明显升高,100mg／kg的维生素E具有部分拮抗肝脏细胞色素P450酶1A1、1A2、181 mRNA水平升高的作用;2）急性TCDD染毒小鼠肝脏SOD和GSH-PX mRNA水平呈现降低的趋势,CAT的mRNA水平明显降低,染毒并给予100mg／kg维生素E,SOD和CATmRNA水平与染毒组相比明显升高,GSH．PxmRNA水平也有升高的趋势。上述结果表明：TCDD能影响或部分影响小鼠肝脏细胞色素P450酶1A1、1A2、181、SOD、CAT、GSH-Px的基因转录,而维生素E能在一定程度上缓解TCDD的作用[动物学报54（6）：1038—1043,2008]。     

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.