三氧化二砷(As2O3)对雄性小鼠的遗传毒性的研究

本以清洁级ICR雄性小鼠为实验动物,研究As2O3对小鼠的遗传毒性。采用小鼠精子畸形实验法以及小鼠骨髓PCE微核实验法,对成年的小鼠腹腔注射0．25—6．0mg/kg/dAs2O3,染毒7d。结果表明,AsO3对小鼠的体重增长及睾丸的重量存在抑制作用,其中1．00mg/kg／d剂量AS2O3对小鼠体重增长及睾丸重量的抑制是最显的(P＜0.001);AS2O3使小鼠精子的畸形率明显增加(P＜0.001),且呈明显的剂量-效应关系;此外As2O3还使小鼠PCE微核率增加,且As2O3与PCE微核率之间也具有明显的剂量效应。结论是As2O3对雄性小鼠具有明显的遗传毒性。     

白细胞介素-18基因肌肉注射产生明显抗肿瘤作用(英文)

 为了探讨人白细胞介素 (h IL ) - 1 8基因转导的抗肿瘤作用 ,构建了 h IL- 1 8c DNA真核表达质粒载体 pc DNA3/h IL- 1 8.将 pc DNA3/h IL- 1 8经脂质体包裹 ,按照 1 0 0μg/只的剂量注射入雄性Balb/c小鼠后肢肌肉 ,在设定时间处死小鼠取注射部位肉提取总 RNA,应用半定量反转录聚合酶链反应 (RT- PCR)及免疫组化法检测了 h IL- 1 8m RNA及其蛋白质在小鼠肌肉中不同时间点的表达水平 .随后 30只雄性 Balb/c小鼠于基因注射后第 7d腹部皮下 (i.d.)或腹腔内 (i.p.)接种 1×1 0 5个同系小鼠 S- 1 80肉瘤细胞 .观察了 S- 1 80肿瘤细胞在腹腔及皮下的生长情况、小鼠体重、肿瘤重量及存活时间 .结果发现 ,pc DNA3/h IL- 1 8注射后 2 d能检测到 h IL- 1 8m RNA表达 ,第 7d表达量较高 ,第 2 8d仍有 h IL- 1 8m RNA表达 .免疫组化染色显示了注射部位散在有 h IL- 1 8蛋白质颗粒 .h IL- 1 8基因注射组小鼠体重、肿瘤重量均比对照组轻 (P值分别小于 0 .0 0 5、0 .0 5) ,存活时间比对照组延长 .结果显示 ,真核表达系统 pc DNA3/h IL - 1 8经脂质体包裹肌注后能有效表达 ,具有明显的抑制肿瘤生长作用 .     

薄荷油对雄性小鼠的抗生育作用研究

目的探讨薄荷油对雄性小鼠的抗生育作用。方法将60只健康的雄性性成熟昆明小鼠随机分成3个试验组和1个对照组,各试验组小鼠灌胃0.135 g/(kg·d),0.27 g/(kg·d)和0.54 g/(kg·d)的薄荷油0.5%羧甲基纤维素钠(sodium carboxymethylcellulose,CMC)混悬液,对照组灌胃0.5%羧甲基纤维素钠溶液,灌胃1周后按雌雄比2∶1合笼,继续对雄鼠灌胃至19 d,采集雄性小鼠的血液并测定血液生化指标,剖检灌胃雌雄小鼠,统计雌性小鼠的怀孕率,测定雄性小鼠睾丸与附睾的脏器系数及附睾精子活力,并固定睾丸和附睾,研究其组织学变化。结果与对照组相比较,雄性小鼠灌胃薄荷油后,导致雌性小鼠的怀孕率降低,睾丸脏器系数和附睾精子活率极显著降低(P<0.01),精子畸形率极显著升高(P<0.01)。光学显微镜下,试验组小鼠睾丸和附睾均有一定程度的损伤,睾丸间质减少,睾丸各级生精细胞排列疏松,曲细精管内有多核巨噬细胞浸润。附睾具正常的管腔结构,但能明显观察到管腔内精子减少。结论薄荷油对雄性小鼠具有抗生育作用,且主要通过影响精子的生成及破坏生精组织而达到,具有实际应用价值,可进一步开发成环境友好型鼠类抗生育药剂。     

环境雌激素硫丹对根田鼠(Microtus oeconomus)生殖毒性效应

为探讨硫丹的生殖毒性,实验选择健康雄性根田鼠20只,随机分成对照组和实验组,分别注射等剂量生理盐水(6mL/kg)和硫丹溶液(7.0mg/kg)。在染毒的第7天和第14天,实验组和对照组各处死5只根田鼠。通过实验,第1阶段实验组与对照组根田鼠的体重变化不大,睾丸系数差异不明显,精子数、精子活动率下降不明显,精子畸形率明显增加(P0.05)。第2阶段实验组与对照组根田鼠的体重变化不大,睾丸系数差异不明显,精子数、精子活动率下降明显,精子畸形率增加,与第1阶段相比,体重没变化,睾丸系数也无明显变化,精子活动率下降明显(P0.05),精子畸形率增加极显著(P0.01)。因此,环境雌激素硫丹可以引起根田鼠睾丸的精子数下降、精子活动率下降、精子畸形率明显增加。     

利褐喷丁衍生物体内外抗结核菌活性的研究

利福喷丁及其衍生物脱乙酰基利福喷丁对人型、牛型和草结核分枝杆菌的MIC10 0 分别为 2和 2、2和 2、0 .5和 0 .2 5mg/L。 10～ 4 0mg/kg剂量的利福喷丁组和脱乙酰基利福喷丁组小鼠半数动物存活时间(ST50 )均超过 2 8d ,2 .5和 5 .0mg/kg剂量的利福喷丁组小鼠ST50 分别为 18和 18d ,2 .5和 5 .0mg/kg剂量的脱乙酰基利福喷丁组小鼠ST50 分别为 16和 2 7d ,感染对照组小鼠ST50 为 13d。实验结果表明利福喷丁及其衍生物脱乙酰基利福喷丁有相似而良好的体内外抗结核分枝杆菌的活性。     

抗鼠疫耶尔森菌F1抗原单克隆抗体对小鼠的被动免疫保护作用

目的研究抗鼠疫耶尔森菌F1抗原单克隆抗体(单抗)被动免疫BALB/c小鼠后的抗鼠疫保护效果,确认鼠疫抗体治疗依据,探索鼠疫免疫学治疗的评价手段。方法将BALB/c小鼠随机分组,用不同剂量的抗鼠疫耶尔森菌F1抗原单抗4C6和2D2分别进行免疫,再分别用不同剂量的鼠疫强毒菌攻击,通过小鼠的存活率和存活时间,判定F1单抗免疫小鼠被动保护其抵抗鼠疫强毒菌攻击的有效性和剂量相关性。结果在14 d的观察期内,在100.0 MLD鼠疫强毒菌攻击下,4C6单抗400.0μg组、200.0μg组、100.0μg组、50.0μg组和25.0μg组小鼠的存活率分别为100%、83%、50%、50%和0%,平均存活时间分别为15.00 d、14.67 d、13.00 d、13.50 d和9.67 d;2D2单抗400.0μg组、200.0μg组、100.0μg组、50.0μg组、25.0μg组小鼠的存活率分别为83%、50%、50%、33%和0%,平均存活时间分别为14.83 d、13.33 d、12.67 d、12.33 d和8.00 d。在10.0 MLD鼠疫强毒菌攻击下,4C6单抗50.0μg组、25.0μg组和12.5μg组小鼠的存活率分别为83%、83%和17%,平均存活时间分别为14.17 d、14.50 d、9.83 d;2D2单抗50.0μg组、25.0μg组、12.5μg组小鼠的存活率分别为100%、33%和33%,平均存活时间分别为15.00 d、12.33d和11.67 d。2.0 MLD和1.0 MLD攻击的未免疫对照组小鼠全部死亡,平均存活时间分别为6.1 d和6.7 d。F1抗原单抗的免疫剂量与小鼠的平均存活时间和存活率有比较明显的相关性(P<0.05)。结论用抗鼠疫耶尔森菌F1抗原单抗被动免疫小鼠,在受到鼠疫强毒菌攻击时,对小鼠具有免疫保护作用。     

虎纹镇痛肽(HWAP-I)在大鼠蜜蜂毒致炎模型中的镇痛作用

研究了在蜜蜂毒致炎模型中虎纹镇痛肽 (HWAP I)的镇痛作用 .HWAP I有 6个剂量组 (n =10 ) ,分别为 0 .1、1、10、2 5、5 0、75 μg/kg .生理盐水作空白对照 .从 10 μg/kg开始不同剂量组表现不同程度的镇痛效果 (P<0 .0 5 ) ,且有一定的量效关系 ;同时用 2 5 μg/kg芋螺毒素SNX III做阳性对照 ,结果表明 2 5 μg/kgSNX III的镇痛效果介于 2 5 μg/kg与 5 0 μg/kgHWAP I之间 .计算得到HWAP I在给药后 1h半有效剂量ED50 大约是 30 μg/kg .     

环境雌激素硫丹对根田鼠(Microtus oeconomous)生殖毒性效应

为探讨硫丹的生殖毒性.实验选择健康雄性根田鼠20只.随机分成对照组和实验组,分别注射等剂量生理盐水(6 mL/kg)和硫丹溶液(7.0 mg/kg).在染毒的第7天和第14天,实验组和对照组各处死5只根田鼠.通过实验,第1阶段实验组与对照组根田鼠的体重变化不大,睾丸系数差异不明显,精子数、精子活动率下降不明显,精子畸形率明显增加(P<0.05).第2阶段实验组与对照组根田鼠的体重变化不大.睾丸系数差异不明显,精子数、精于活动率下降明显,精子畸形率增加,与第1阶段相比,体重没变化,睾丸系数也无明显变化,精子活动率下降明显(P<0.05),精子畸形率增加极显著(P<0.01).因此,环境雌激素硫丹可以引起根田鼠睾丸的精子数下降、精子活动率下降、精子畸形率明显增加.     

合欢皮总皂苷对雄性小鼠的抗生育作用研究

目的探讨合欢皮总皂苷对雄性小鼠的抗生育作用。方法将60只健康的雄性性成熟昆明小鼠随机分成3个试验组和1个对照组,各试验组小鼠灌胃540 mg·(kg·d)-1,270 mg·(kg·d)-1和135 mg·(kg·d)-1的合欢皮总皂苷水溶液,对照组自由饮水,灌胃1周后按雌雄比2∶1合笼,继续对雄鼠灌胃至19 d,采集雄性小鼠的血液并测定血液生化指标,剖检灌胃雌性小鼠,统计雌性小鼠的怀孕率,测定雄性小鼠睾丸与附睾的脏器系数及附睾精子活力,并固定睾丸和附睾,研究其组织学变化。结果与对照组相比较,雄性小鼠灌胃合欢皮总皂苷后,导致雌性小鼠的怀孕率降低,睾丸脏器系数和附睾精子活率极显著降低(P<0.01),精子畸形率极显著升高(P<0.01)。光学显微镜下,试验组小鼠睾丸和附睾均有一定程度的损失,睾丸生精细胞排列疏松,间质减少,可见曲细精管内有多核巨噬细胞浸润,各级生精细胞脱落。附睾具正常的管腔结构,但能明显观察到管腔内精子几乎消失。结论合欢皮总皂苷对雄性小鼠具有抗生育作用,主要通过影响精子的生成及破坏生精组织而达到。     

乙酸铜对雄性小白鼠生殖毒性的影响

以清洁级ICR雄性小白鼠为实验动物,研究不同剂量乙酸铜对小白鼠的生殖毒性。采用小白鼠精子畸形实验及小白鼠骨髓嗜多染红细胞(以下简称PCE)微核实验等方法。分别对成年小白鼠腹腔每天注射0.25~16.00mg/kg8个剂量的乙酸铜,染毒7天。结果表明:乙酸铜对小白鼠的体重增长及睾丸重量具有一定的抑制作用,其中组VI、组VII的最明显。不同剂量的乙酸铜均使雄性小白鼠精子密度(P<0.001)、精子活力明显降低,具有明显的剂量效应。各实验组精子畸形率、PCE微核率均明显高于对照组(P<0.001)(P<0.05或P<0.001),且均随乙酸铜剂量的增加而明显升高。结果表明实验剂量的乙酸铜对ICR雄性小白鼠具有明显的生殖毒性效应。     

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).