甘草对大鲵抗嗜水气单胞菌感染的作用

通过投喂甘草提取物, 研究了甘草对大鲵(Andrias davidianus)抗嗜水气单胞菌(Aeromonas hydrophila)感染的作用。连续投喂56d, 从28d开始, 药物组血清溶菌酶活性先升后降, 呈抛物线趋势, 低剂量组在42d出现最大值(158.4±34.7) U/mL, 高剂量组在35d出现最大值(178.3±28.8) U/mL, 两者都显著高于同期对照组(P<0.05)。药物组在最后两次采样期, 即42d和56d时, 肾脏巨噬细胞吞噬活性显著高于对照组(P<0.05)。低剂量组和高剂量组最大值均出现在42d, 分别为(59.4±8.5)%和(58.4±5.2)%。同期相比, 药物组白细胞比容值均高于对照组。其中, 高剂量组在28d时白细胞比容值为(5.8±1.7)%, 低剂量组在56d时为(5.5±0.8)%, 高剂量组在56d时为(5.9±1.7)%, 三者都显著高于同期对照组(P<0.05)。药物组和对照组的脾脏脏器系数之间没有显示出显著差异。最后一次采样(56d)后人工感染嗜水气单胞菌, 对照组死亡率为90%, 低剂量组和高剂量组都为60%, 均低于对照组, 而药物组免疫保护率为33.3%, 也都高于对照组。结果表明, 投喂甘草提取物可在一定程度上提高大鲵对嗜水气单胞菌的抗性。     

超滤得到的海蜇酶解产物的降血脂功能评价

目的:探讨超滤对于海蜇酶解产物降血脂功能的提高作用。方法:海蜇通过中性蛋白酶酶解后,将超滤过的酶解产物和未超滤的酶解产物分别按照高、中、低三个剂量组喂食高血脂症大鼠模型42d,测定各组血脂水平并进行对照分析。结论:未超滤组的高、中剂量组和超滤组高中低剂量组喂食42d后均观察到大鼠血清总胆固醇(TC)、甘油三酯(TG)的降低,其中未超滤中剂量组(灌胃剂量5 mg/kg.BW)血清总胆固醇(TC)值为2.45±0.28mmol/L,超滤低剂量组(灌胃剂量0.3mg/kg.BW)血清总胆固醇(TC)值为2.61±0.33mmol/L,均明显低于高脂模型对照组(3.38±0.22 mmol/L),未超滤低剂量组(灌胃剂量3mg/kg.BW)血清总胆固醇(TC)值为2.82±0.38mmol/L,相对于高脂模型对照组(3.38±0.22 mmol/L)无显著差异;未超滤中剂量组(灌胃剂量5 mg/kg.BW)甘油三酯(TG)值为0.90±0.21mmol/L,超滤低剂量组(灌胃剂量0.3mg/kg.BW)甘油三酯(TG)值为0.93±0.14 mmol/L,均明显低于高脂模型对照组(1.21±0.20 mmol/L),未超滤低剂量组(灌胃剂量3mg/kg.BW)甘油三酯(TG)值为1.18±0.12mmol/L,相对于高脂模型对照组(1.21±0.20 mmol/L)无显著差异。结论:海蜇多肽的酶解产物具有降血脂功能,超滤能够有效提高海蜇酶解产物的降血脂活性。     

鼠李糖乳杆菌grx10降血脂效果初探

目的采用随机、双盲、安慰剂对照研究,观察鼠李糖乳杆菌grx10对血脂异常者血脂水平的改善作用。方法筛选符合纳入排除标准的血脂指标检测异常者,随机分为对照组、低剂量组、高剂量组。对照组给予安慰剂10g/d,低剂量组给予grx10粉剂4g/d(3.2×10~(10) CFU/d)以及安慰剂6g/d,高剂量组给予grx10粉剂10g/d(8.0×10~(10) CFU/d)。试验周期为2周洗脱期+6周干预期。观察记录受试者干预前后血脂水平等。结果 44人完成试验,其中高剂量组17人,低剂量组14人,安慰剂组13人。益生菌高剂量干预组血清TC、TG、LDL-C水平与干预前相比显著下降(P0.05);三组间比较血脂改变差值差异无统计学意义。结论 grx10达到一定剂量时可降低人体血清TC、TG、LDL-C水平,后续本研究将继续扩大样本量,进一步明确grx10的降脂效果。     

陈皮的凝血止血与抗血栓作用研究

目的:研究陈皮水提物的止血与抗血栓作用。方法:(1)凝血止血实验选用40只昆明种SPF小白鼠,按雌雄各半比例,将小鼠随机分为5组(对照组、云南白药组、低中高剂量陈皮水提物组),每组8只。给药组以陈皮2.0、3.0、4.0 g/kg剂量连续灌胃14天,对照组按等体积给予0.9%生理盐水,第14天灌胃1 h后运用毛细管法、剪尾法分别测定凝血时间(CT)、出血时间(BT);(2)运用不同剂量陈皮对SD大鼠体外血浆复钙时间测定,考察了不同剂量陈皮水提物对大鼠体外血浆复钙(PRT)的影响。结果:(1)凝血止血实验中,正常对照组、低剂量组的BT分别为5.44±4.5 min和3.81±1.4 min,与正常对照组相比,陈皮水提物低剂量组可以缩短出血时间(P0.05);(2)体外血浆复钙实验中,正常对照组、中剂量组和高剂量组的PRT分别为1.96±0.6 min、4.57±2.6 min和14.74±6.5 min,与正常对照组相比,陈皮水提物中、高剂量组体外血浆复钙时间明显延长(P0.05)。结论:低剂量陈皮水提物组具有一定的止血作用,中、高剂量陈皮水提物组具有一定的体外抗凝活性,能抑制血栓形成。     

嗜酸乳杆菌MG2_1对大鼠血清脂质代谢的影响研究

利用从蒙古国酸马奶中分离鉴定,并通过耐酸性及体外降胆固醇能力测试筛选获得的L.acidophilusMG2_1菌制备成活菌体和热致死菌体制剂与高脂饲料同时灌喂Wistar系大鼠,研究探讨了对其血清脂质代谢的影响。结果显示,试验第14天时菌活菌体组和热致死菌体组与单纯饲喂高脂饲料对照组比较,对大鼠血清胆固醇浓度的上升分别呈现显著(p<0.05)和极显著的抑制效果(p<0.01),其热致死菌体组大鼠血清HDL_C,显著高于高脂饲料对照组(p<0.05)。并且各试验组大鼠动脉硬化指数均极显著地低于高脂饲料对照组(p<0.01)。热致死菌体组大鼠粪便中总胆汁酸含量也显著高于高脂饲料组(p<0.05)。可见,该菌株具有一定的抑制大鼠血清胆固醇含量上升和预防动脉硬化的作用。但在整个试验期内不改变灌服菌液剂量的情况下,随着试验时间的延长,该菌株对大鼠血清脂质的影响呈减弱趋势。     

溴氰菊酯对大鼠神经细胞凋亡及HO-1活性的影响

目的:探讨溴氰菊酯(DM)对大鼠神经细胞凋亡及血红素氧化酶-1(HO-1)活性的影响.方法:健康SD雄性大鼠48只,随机分为正常对照组、低剂量DM组、高剂量DM组和高剂量DM ZnPP组,连续腹腔注射染毒5天,末次染毒24小时后进行神经细胞凋亡及HO-1活性的测定.结果:各组细胞凋亡数按对照组＜低剂量DM组＜高剂量DM组＜高剂量DM ZnPP组逐渐增加,差异具有统计学意义(P＜0.05).与对照组相比,低剂量DM组、高剂量DM组HO-1活性增加,差异均具统计学意义(P＜0.05);高剂量DM ZnPP组HO-1活性与对照组差异无统计学意义(P＞0.05),但明显低于低、高剂量DM组(P＜0.05).结论:溴氰菊酯可引起脑神经细损伤,HO-1活性增高并对脑损伤发挥一定的保护作用.     

美洲大蠊精粉对小鼠血糖和肌酐的影响

目的研究美洲大蠊Periplaneta americana精粉对高脂饮食小鼠体质量、血糖和肌酐的影响。方法高脂饮食小鼠分为对照组和实验组(给予美洲大蠊精粉:低剂量100 mg·kg~(-1)、中剂量200 mg·kg~(-1)、高剂量400 mg·kg~(-1))。灌胃第42天和第49天取血后,用试剂盒测定血清血糖和肌酐的含量,实时荧光定量PCR法检测肝脏中葡萄糖-6-磷酸酶(G-6-Pase)、葡萄糖转运蛋白2(GLUT2)和肾脏中单核细胞趋化蛋白-1(MCP-1) mRNA的表达水平。结果与对照组相比,中、高剂量组体质量增长率在第42天和第49天均显著低于对照组(P 0. 05,P 0. 01)。第42天实验组小鼠的血糖、肌酐和MCP-1 mRNA水平与对照组相比有降低趋势,但差异无统计学意义(P 0. 05),中、高剂量组的G-6-Pase mRNA水平极显著低于对照组(P 0. 01),GLUT2 mRNA水平的差异无统计学意义(P 0. 05)。第49天,低、高剂量组小鼠的血糖和肌酐水平显著低于对照组(P 0. 05),且低、中、高剂量组的G-6-Pase、GLUT2和MCP-1 mRNA水平显著低于对照组(P 0. 05,P 0. 01)。结论美洲大蠊精粉可降低高脂饮食小鼠的体质量增长率以及血糖、血清肌酐水平,减少肝脏中G-6-Pase mRNA表达和调节GLUT2 mRNA表达水平可能是美洲大蠊精粉降血糖机制之一,并且可能通过降低肾脏中MCP-1 mRNA的表达减轻肾脏损伤。     

美洲大蠊醇提物对大鼠抗氧化应激的影响

目的研究美洲大蠊Periplaneta americana醇提物对大鼠血清和卵巢抗氧化指标的影响。方法 17只成年雌性SD大鼠适应饲养7 d后,随机分为3组:对照组(9 m L·kg~(-1),生理盐水)5只、低剂量组(9 m L·kg~(-1),0.03 g·m L~(-1)美洲大蠊醇提物)6只、高剂量组(9 m L·kg~(-1),0.09 g·m L~(-1)美洲大蠊醇提物)6只。每2天灌胃1次,共饲养30 d。实验结束后,采集大鼠血清和卵巢,检测血清中丙二醛(MDA)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、一氧化氮(NO)、谷胱甘肽过氧化物酶(GSH-PX)指标和卵巢中SOD、GSH-PX、CAT基因表达的变化。结果与对照组相比,高剂量组(P=0.085)、低剂量组(P=0.091)血清中的NO含量均有降低的趋势;高剂量和低剂量的美洲大蠊醇提物均显著提高了大鼠血清中的SOD含量(P<0.05),同时,高剂量组血清中的MDA含量显著降低(P<0.05);此外,高剂量组和低剂量组卵巢SOD基因的表达显著升高(P<0.05)。结论美洲大蠊醇提物升高了大鼠血清SOD的含量,降低了NO和MDA的含量,同时,还提高了卵巢SOD基因的表达,说明美洲大蠊醇提物对大鼠卵巢具有一定的抗氧化应激功能。     

补肾填精法对脑卒中失眠症模型大鼠血清褪黑素含量表达的影响

目的:探讨补肾填精法对脑卒中失眠症模型大鼠血清褪黑素(Melatonin,MT)含量表达的影响。方法:24只建模成功的脑卒中失眠症大鼠随机平分为3组-模型组、低剂量组、高剂量组。于造模第7 d起,三组分别给予生理盐水及补肾填精汤(低剂量组最终含生药浓度低剂量为0.7 g/mL、中剂量为1.4 g/mL)以1 mL/(100 g·d)灌胃,连续14 d,记录血清MT表达变化情况。结果:三组治疗第1 d、第7 d与第14 d的逃避潜伏期在组内与组间对比差异无统计学意义(P>0.05)。低剂量组、高剂量组治疗第7 d与第14 d的进入中央区次数多于模型组(P<0.05),也多于治疗第1 d(P<0.05),高剂量组也多于低剂量组(P<0.05)。低剂量组、高剂量组治疗第14 d的血清MT含量、去甲肾上腺素转运蛋白与褪黑素受体蛋白相对表达水平高于模型组(P<0.05),高剂量组高于低剂量组(P<0.05)。结论:补肾填精法在脑卒中失眠症模型大鼠中的应用能促进血清MT的释放,提高去甲肾上腺素转运蛋白与褪黑素受体蛋白的表达,从而促进缓解失眠症状。     

土人参提取液对D-半乳糖所致衰老小鼠的抗氧化作用研究

本文研究了土人参提取液对D-半乳糖所致衰老小鼠的抗氧化作用的影响。取昆明种小白鼠50只,随机分为5组(正常对照组、衰老模型组、土人参提取液低、中、高剂量组)。除正常对照组外,其余各组每天于颈背皮下注射D-半乳糖125 mg/kg,连续42 d,造成亚急性衰老模型。在注射D-半乳糖的同时,三个不同剂量实验组每天分别灌胃土人参提取液5、10和15g/kg,正常对照组及衰老模型组给予等量生理盐水。于42 d后测定小鼠体内超氧化物歧化酶(Super Oxide Dismutase,SOD)、谷胱甘肽过氧化物酶(Glutathione peroxidase,GSH-PX)等酶的活性,及丙二醛(Maleic Dialdehyde,MDA)的含量。结果显示:与正常对照组相比,衰老模型组小鼠心脏、肝脏组织SOD及血清中GSH-PX活性降低(P0.01),MDA含量增加(P0.01)。与衰老模型组相比,土人参提取液低、中、高剂量组小鼠心脏、肝脏组织SOD及血清中GSH-PX活性明显升高(P0.01);中、高剂量组小鼠心脏、肝脏组织中MDA含量降低明显(P0.01),低剂量组小鼠肝脏的MDA含量明显降低(P0.01)。上述结果表明:土人参提取液对D-半乳糖所致衰老小鼠有抗衰老作用。     

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.