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。     

维生素E对TCDD染毒小鼠白细胞介素和T细胞亚群的影响

为研究维生素E(VE)对2,3,7,8四-氯代二苯并-对-二噁英(TCDD)染毒雄性小鼠白细胞介素(IL)和T细胞亚群的影响,我们设计了5个实验组,将40只小鼠随机分为5组,5组动物给予TCDD和维生素E的水平依次为:TCDD 0 ng/kg和VE0 mg/kg、TCDD 100 ng/kg和VE0 mg/kg、TCDD 100 ng/kg和VE20 mg/kg、TCDD 100ng/kg和VE100 mg/kg、TCDD 100 ng/kg和VE500 mg/kg。灌胃7周后取其血液和脾脏,用酶联免疫法测小鼠血清IL的水平,用流式细胞仪法测定脾脏T淋巴细胞亚群的变化。结果表明:TCDD染毒组小鼠血清IL-1α水平明显高于对照组;VE20 mg/kg和100 mg/kg的两组,其血清IL-1α水平均明显低于染毒组;而VE500 mg/kg组,其血清IL-1α水平与染毒组间差异没有统计学意义;TCDD染毒组小鼠血清IL-2水平明显低于对照组;VE100 mg/kg和500 mg/kg两组,其血清IL-2水平明显高于染毒组;TCDD染毒组CD4 T淋巴细胞百分比明显低于对照组;给予VE的三组,其脾CD4 T淋巴细胞百分比与TCDD染毒组相比有升高的趋势,但没有统计学意义;TCDD染毒组小鼠脾CD8 T淋巴细胞百分比明显高于对照组;VE为100 mg/kg组,其脾CD8 T淋巴细胞百分比明显低于染毒组和VE20 mg/kg两组;VE500 mg/kg组,其脾CD8 T淋巴细胞百分比明显低于染毒组。表明TCDD能导致机体白细胞介素分泌的紊乱以及脾脏T淋巴细胞亚群的变化,而适当剂量的VE对TCDD所致的毒性有拮抗作用。     

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]。     

维生素C和B_1对铅致小鼠睾丸损伤保护作用研究

目的探讨维生素C、B1联合用药拮抗铅对睾丸的毒性作用。方法 1.30只雄性小鼠随机分为2组(15只/组):空白对照组和铅染毒组。染铅组雄性小鼠每日腹腔注射醋酸铅20 mg/kg,空白对照组给予等容量的生理盐水,一日一次,第42日结束以上实验。将小鼠取血,用试剂盒检测血浆中谷胱甘肽的含量、谷胱甘肽过氧化物酶(GPx)和谷胱甘肽还原酶(GR)的活性。将睾丸组织经过处理后,在光镜及透射电镜下观察睾丸组织结构变化;2.45只雄性小鼠随机分为3组(15只/组):空白对照组、铅染毒组和维生素联合干预组。染铅组雄性小鼠每日腹腔注射醋酸铅20 mg/kg,维生素干预组在染铅后,即时每组小鼠给予维生素C和维生素B1,一日一次,第42日结束。处死小鼠,取血,用试剂盒检测血浆中谷胱甘肽的含量,谷胱甘肽过氧化物酶(GPx)和谷胱甘肽还原酶(GR)的活性。在光镜以及透射电镜下观察睾丸组织结构变化。结果1.与空白对照组比较,醋酸铅染毒组小鼠血浆中还原型谷胱甘肽(GSH)的水平降低,GSH/GSSG的比例降低,GPX活性升高,GR活性降低;光镜下睾丸组织生精小管变薄,各级生精细胞、支持细胞减少,部分细胞核出现核固缩;3.电镜下染毒组小鼠睾丸组织超微结构变化明显,支持细胞溶酶体增多,线粒体肿胀空泡化;2.与醋酸铅染毒组比较,维生素干预组小鼠血浆中还原型谷胱甘肽(GSH)的水平升高,GSH/GSSG的比例升高,GPx活性降低,GR活性升高;光镜观察结果:与染铅组相比,维生素B1和C联合干预组中破坏的睾丸生精上皮有所恢复;电镜观察结果:与染铅组相比,维生素B1和C联合干预组睾丸组织超微结构基本恢复正常,生精细胞和支持细胞结构正常,细胞器丰富。结果 1.醋酸铅使体内GSH的水平降低,GPX活性升高,GR活性降低,从而诱导氧化应激的发生,导致染铅小鼠睾丸的损伤;2.维生素干预组小鼠血浆中还原型谷胱甘肽(GSH)的水平升高,GSH/GSSG的比例升高,GPx活性降低,GR活性升高,维生素干预组小鼠血浆中氧化型谷胱甘肽还原为还原型谷胱甘肽,从而发挥抗氧化作用,对小鼠睾丸起到保护作用。     

维生素E对三氯乙烯急性染毒大鼠肝脏脂质过氧化与抗氧化酶的影响

本文观察了用抗氧化剂维生素E预处理后,三氯乙烯(3000mg/kg B-W-) 一次性经口染毒24h 大鼠肝脏的超氧化物歧化酶、谷胱甘肽过氧化物酶等抗氧化酶活力及丙二醛含量的变化,结果表明三氯乙烯染毒组肝脏中丙二醛含量、超氧化物歧化酶活力及血清谷丙转氨酶、谷草转氨酶活力均高于对照组(P< 0-01) ;而维生素E干预组的丙二醛含量、超氧化物歧化酶活力及血清谷丙转氨酶、谷草转氨酶活力均分别低于三氯乙烯染毒组(P< 0-01) ,说明三氯乙烯急性染毒可引起肝脏脂质过氧化反应及肝损害,肝脏超氧化物歧化酶活力升高可能是机体受自由基及脂质过氧化反应刺激而诱导产生的一种适应性反应,维生素E对三氯乙烯所致的肝损害有一定的保护作用。     

芹菜素对雌性大鼠生殖轴的影响

目的：探讨芹菜素在10-9mol/L浓度时对雌性大鼠生殖功能的影响。方法：应用侧脑室注射方法观察芹菜素对雌性大鼠生殖轴激素含量的影响。在侧脑室注射后第3天取血浆,采用放免技术测定血浆中促性腺激素释放激素（GnRH）、卵泡刺激素（FSH）、黄体生成素（LH）、雌二醇（E2）、孕酮（P）的含量。结果：在给药后第3天血浆中促性腺激素释放激素（GnRH）、卵泡刺激素（FSH）、黄体生成素（LH）的含量增加而雌二醇（E2）、孕酮（P）的含量降低,差异有显著性。结论：芹菜素抑制雌二醇（E2）合成中芳香化酶的活性实现对雌二醇（E2）、孕酮（P）分泌的抑制。芹菜素通过影响雌激素受体而使下丘脑的促性腺激素释放激素（GnRH）和腺垂体的卵泡刺激素（FSH）、黄体生成素（LH）分泌增加。     

当归多糖通过AKT/FOXO3通路调节免疫性卵巢早衰小鼠内分泌功能

为探讨当归多糖(angelica polysaccharide,AP)对免疫性卵巢早衰小鼠内分泌功能的影响及分子机制,本研究将60只雌性BALB/c小鼠分为正常组、模型组、AP低剂量(100 mg/kg)、中剂量(200 mg/kg)、高剂量(400 mg/kg)组和补佳乐阳性组,以小鼠透明带多肽为抗原,皮下多点注射建立免疫性卵巢早衰(premature ovarian failure,POF)小鼠模型,灌胃相应药物,连续治疗4周后检测各组小鼠卵巢指数,检测各组小鼠血液SOD和MDA水平;通过ELISA检测各组小鼠卵巢组织IL-1β和IL-6水平,Western blotting检测各组小鼠p-AKT和FOXO3蛋白表达水平。与空白组相比,模型组小鼠卵巢指数显著降低,与模型组比较,AP低、中、高剂量组和阳性组小鼠卵巢指数显著升高,差异具有统计学意义(p<0.01)。与空白组比较,模型组小鼠血液SOD活性显著降低,MDA含量显著升高,与模型组比较,AP低、中、高剂量组和阳性组小鼠血液SOD活性显著升高,MDA含量显著降低。ELISA结果显示,与空白组比较,模型组小鼠卵巢组织IL-1β和IL-6含量显著升高,与模型组比较,AP低、中、高剂量组小鼠卵巢组织IL-1β和IL-6含量显著降低,差异具有统计学意义(p<0.01)。Western blotting结果显示,与空白组比较,模型组小鼠卵巢p-AKT和FOXO3蛋白表达显著降低,与模型组比较,AP低、中、高剂量组和阳性组小鼠卵巢p-AKT和FOXO3蛋白表达显著升高,差异具有统计学意义(p<0.01)。本研究结果说明,当归多糖AP激活AKT/FOXO3通路,抑制小鼠氧化应激,改善免疫性卵巢早衰小鼠内分泌功能,可在一定程度上抑制免疫卵巢早衰。     

低剂量三聚氰胺对小鼠精子质量影响的研究

采用灌胃法,研究了三聚氰胺在1.0 mg/kg、2.0 mg/kg、4.0 mg/kg浓度下染毒35 d时,小鼠体重、精子运动参数和精子形态的变化.结果显示,4.0 mg/kg 处理组小鼠部分精子运动参数显著性降低(P＜0.05),1.0 mg/kg 和2.0 mg/kg 浓度组各项精子运动参数与对照比较变化不显著(P＞0.05);在染毒一周后,2.0 mg/kg 浓度组小鼠体重增长显著性下降(P＜0.05),4.0 mg/kg 浓度组小鼠体重极显著降低(P＜0.01);3个处理浓度组对小鼠精子形态影响均不显著.总之,食物中低浓度三聚氰胺对小鼠精子活性和形态无明显的影响.     

维生素E对三氯乙烯急性染毒大鼠

本文观察了用抗氧化剂维生素E预处理后,三氯乙烯(3000mg/kg B.W.)一次性经口染毒24h大鼠肝脏的超氧化物歧化酶、谷胱甘肽过氧化物酶等抗氧化酶活力及丙二醛含量的变化,结果表明三氯乙烯染毒组肝脏中丙二醛含量、超氧化物歧化酶活力及血清谷丙转氨酶、谷草转氨酶活力均高于对照组(P＜0.01);而维生素E干预组的丙二醛含量、超氧化物歧化酶活力及血清谷丙转氨酶、谷草转氨酶活力均分别低于三氯乙烯染毒组(P＜0.01),说明三氯乙烯急性染毒可引起肝脏脂质过氧化反应及肝损害,肝脏超氧化物歧化酶活力升高可能是机体受自由基及脂质过氧化反应刺激而诱导产生的一种适应性反应,维生素E对三氯乙烯所致的肝损害有一定的保护作用。     

亚硒酸钠对西门塔尔母牛发情周期生殖激素分泌的影响

选用12头18月龄,体况良好,体重380 kg的西门塔尔牛育成母牛,采用完全随机区组设计分为4组,研究亚硒酸钠(0、0.3、0.6和0.9 mg Se/kg DM)对发情周期外周血清促黄体素、促卵泡素、孕酮和雌二醇分泌的影响。结果表明:日粮添加亚硒酸钠后发情周期促黄体素、促卵泡素、孕酮和雌二醇分泌水平提高,0.3 mg/kg组和0.6 mg/kg组显著高于对照组(P<0.05),0.3 mg/kg组较0.6 mg/kg组高(P>0.05)。根据试验结果推断以亚硒酸钠为硒源,添加0.3 mg Se/kg DM对发情周期生殖激素分泌有显著促进作用,兼顾基础日粮的含硒量,建议日粮硒水平为0.37 mg Se/kg DM。     

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.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV