菲对斑马鱼鳃和肝组织结构的影响

采用浓度为0、0.05和100.0 μg·L-1的菲水溶液对斑马鱼(Brachydanio rerio)进行36 d的暴露实验,研究了菲对斑马鱼鳃、肝结构的影响.H-E染色显示:在0.05和100.0 μg·L-1的菲溶液暴露下,受试鱼的鳃受到损伤,均发生鳃小片上皮细胞肥大和水肿;菲浓度为100.0 μg·L-1时,受试鱼还发生鳃丝上皮增厚、鳃小片上皮隆起现象.此外,菲暴露造成斑马鱼的肝组织损伤,0.05 μg·L-1的菲溶液暴露下,受试鱼的肝细胞发生肿大,胞质产生空泡;菲浓度为100.0 μg·L-1时,受试鱼的肝细胞变得不规则,细胞核萎缩变形和偏离细胞中心,部分肝细胞空泡化程度加重,发生核溶解或细胞溶解,造成局部肝组织坏死.表明水环境中菲浓度达到0.05 μg·L-1即已对斑马鱼的鳃、肝产生毒性作用;而菲浓度达到100.0 μg·L-1时,受试鱼的鳃、肝将受到较严重的损伤;伴随菲浓度的升高,鱼的鳃、肝损伤加重.     

金属铜在日本沼虾体内的分布和积累

应用组织化学、透射电镜和原子吸收光谱分析等方法,研究了铜在日本沼虾各主要器官和组织中的分布和积累情况。结果表明,在铜离子浓度为0.08 mg.L-1的溶液中暴露10 d后的日本沼虾肝胰脏内,具有大量的电子密度较高的铜颗粒,主要分布在肝胰脏的肝小管和R细胞中,在血腔中有从R细胞排出的铜颗粒;电镜观察发现铜主要分布在细胞内的溶酶体中,少量颗粒吸附在滑面内质网上;这些铜颗粒通过积聚,在细胞顶端逐渐增多,从而出现外排现象。中肠细胞内也分布有铜颗粒,细胞质出现空泡化,线粒体内嵴部分解体,并有铜颗粒附着在线粒体上。在触角腺中分布有少量的铜颗粒,触角腺细胞内的铜颗粒主要分布于溶酶体中,内质网出现弯曲。原子吸收光谱分析结果表明,肝胰脏中铜的含量最高,达到546.39 mg.kg-1,肝胰脏有储藏铜元素的功能。     

壬基酚和雌二醇干扰罗氏沼虾卵黄蛋白原VTG基因表达的效应

对刚孵化后的罗氏沼虾(Macrobrachium rosenbergii)亲虾用高低两个浓度的壬基酚(nonylphenol,NP,100μg/L和0·01μg/L)和雌二醇(estradiol,E2,1μg/L和0·01μg/L)进行浸泡处理,分别于3d和5d对罗氏沼虾肝胰腺和卵巢中卵黄蛋白原(vitellogenin,VTG)基因表达变化进行半定量分析。结果显示,NP和E2能够提高罗氏沼虾肝胰腺和卵巢中卵黄蛋白原VTG基因的表达。100μg/LNP对罗氏沼虾表现出雌激素效应,0·01μg/LNP作用效果不明显;而E2则在1μg/L和0·01μg/L两个浓度下均对罗氏沼虾有较强的雌激素效应。在100μg/LNP作用下,卵巢VTG表达量3d和5d均保持较高水平,无明显下降,其他实验组均是3dVTG基因表达量升高,5d后表达量较3d表达量有所降低。结果表明,与其他动物一样,NP对罗氏沼虾具有内分泌干扰作用。     

铅在日本沼虾体内的分布和积累

应用组织化学、透射电镜和原子吸收光谱分析等方法,研究了Pb在日本沼虾各主要器官和组织中的分布和积累情况.结果表明,在浓度为0.625mg·L^-1Pb溶液暴露10d后的日本沼虾触角腺内,具有大量的电子密度较高的Pb颗粒.在电镜下细胞内的溶酶体中沉积有大量的Pb颗粒,这些Pb通过积聚,在细胞顶端部位逐渐增多,从而出现外排现象.中肠细胞内含有Pb颗粒,细胞质出现空泡化,核膜和线粒体内嵴部分解体.肝胰脏细胞内除分布有少量Pb颗粒外,细胞结构基本完整.在沼虾鳃细胞内未发现Pb颗粒,但在鳃丝之间发现少量Pb颗粒吸附在鳃丝的表面.原子吸收光谱分析结果表明,触角腺中Pb含量最高,达637.6mg·kg^-1;触角腺在Pb的解毒方面起着重要作用.     

He-Ne激光照射罗氏沼虾心脏、肌肉、鳃和脑神经节组织细胞光学显微镜观察

本文采用He-Ne激光照射罗氏沼虾的心脏、肌肉、鳃和脑神经节,研究其对罗氏沼虾组织细胞形态结构的影响。结果发现：(1)实验组的心脏、肌肉和鳃组织具有明显异染色质的细胞数量百分比分别为16．70％、6．06％、9．35％,而对照组的心脏、肌肉和鳃组织具有明显异染色质的细胞数量百分比分别为8．10％、2．59％和4．55％,表明He-Ne激光照射后,心脏、肌肉和鳃组织具有明显异染色质的细胞数量均有所增加;(2)在实验组中脑神经节的神经分泌细胞要比对照组的缩小7．4μm,实验组的细胞核要比对照组要缩小1．53μm,表明He-Ne激光照射后,脑神经节的神经细胞和细胞核的大小发生明显变化,尤为突出的是神经细胞发生明显的缩小现象。     

铅在日本沼虾体内的分布和积累

应用组织化学、透射电镜和原子吸收光谱分析等方法,研究了Pb在日本沼虾各主要器官和组织中的分布和积累情况。结果表明,在浓度为0．625mg·L^-1Pb溶液暴露10d后的日本沼虾触角腺内,具有大量的电子密度较高的Pb颗粒．在电镜下细胞内的溶酶体中沉积有大量的Pb颗粒,这些Pb通过积聚,在细胞顶端部位逐渐增多,从而出现外排现象．中肠细胞内含有Pb颗粒,细胞质出现空泡化,核膜和线粒体内嵴部分解体．肝胰脏细胞内除分布有少量Pb颗粒外,细胞结构基本完整．在沼虾鳃细胞内未发现Pb颗粒,但在鳃丝之间发现少量Pb颗粒吸附在鳃丝的表面原子吸收光谱分析结果表明,触角腺中Pb含量最高,达637．6mg·kg^-1;触角腺在Pb的解毒方面起着重要作用。     

不同浓度阿维菌素对鲤鱼过氧化氢酶和谷胱甘肽-S-转移酶活性的影响

采用半静态水质接触染毒法,研究不同浓度(0、3.2、5.6、7.5、10.0和18.0μg.-1)阿维菌素对鲤鱼(Cyprinus carpio)肝胰脏和肌肉过氧化氢酶(CAT)、谷胱甘肽-S-转移酶(GSTs)活性的影响。结果表明:除3.2μg.L-1浓度对CAT和GSTs活性无显著影响外,其余各浓度的阿维菌素均对鲤鱼组织中CAT和GSTs产生显著影响,总体表现为低浓度诱导,高浓度先诱导后抑制;5.6和7.5μg.L-1浓度组的肌肉CAT活性与对照组相比无显著差异,肝胰脏CAT活性以及肌肉和肝胰脏GSTs活性均显著升高;10.0和18.0μg.L-1浓度组的肌肉和肝胰脏中CAT、GSTs活性先显著升高,随后又显著下降;解除污染胁迫10d,18.0μg.L-1浓度组的肝胰脏中酶活性不能恢复到正常水平,其余各组与对照无显著差异,说明高浓度阿维菌素暴露可能对鲤鱼机体造成不可逆损伤;阿维菌素暴露浓度与其对鲤鱼肝胰脏和肌肉CAT、GSTs活性抑制率之间具有显著的剂量-效应关系,可以考虑将其作为水体中阿维菌素类药物污染的生物标志物;同时,由于鲤鱼受污染胁迫时肌肉CAT、GSTs活性变化的显著性均远低于肝胰脏,因此当考虑...     

高效氯氰菊酯对草鱼器官酸性磷酸酶活性的影响

研究了暴露于不同高效氯氰菊酯浓度下草鱼Ctenopharyngodon idellas鳃、肝胰脏和肾脏的酸性磷酸酶(Acid Phosphatase,ACP)的活性变化。实验中高效氯氰菊酯浓度设5组,其中对照组1个(0μg/L),处理组4个(0.5μg/L、1.0μg/L、3.0μg/L、5.0μg/L)。每组随机投放40尾草鱼,分别于1d、5d、12d取样,测定鳃、肝胰脏和肾脏的ACP活性。结果显示,鳃ACP活性低浓度(0.5μg/L、1.0μg/L)短时间(1d)暴露下显著增加(P<0.01),高浓度(3.0μg/L、5.0μg/L)暴露时显著下降(P<0.01);肝胰脏ACP活性暴露1d时,除0.5μg/L组外,其他处理组均显著下降(P<0.05、P<0.01),暴露5d、12d时,各处理组均显著上升(P<0.05、P<0.01);肾脏ACP活性除0.5μg/L组在暴露1d、5d时无显著变化(P>0.05)外,其他处理组在暴露时间内均显著下降(P<0.01)。实验表明:高效氯氰菊酯能够通过影响草鱼鳃、肝胰脏和肾脏中酶的活性,干扰这些器官的代谢平衡,进而对这些器官产生毒害作用。     

溶解氧对线纹海马幼鱼氨氮耐受性的影响及氨氮胁迫下鳃、肝脏组织结构的变化

为了解氨氮对线纹海马(Hippocampus erectus)幼鱼的毒理影响,本实验探讨了在正常溶解氧(4.32~5.12 mg·L-1)和高溶解氧(8.22~9.46 mg·L-1)条件下,线纹海马幼鱼的氨氮半致死浓度,以及6、9、12 mg·L-1的氨氮溶液胁迫下线纹海马幼鱼的鳃、肝脏组织结构的变化。结果表明:正常溶解氧条件下,氨氮对线纹海马幼鱼96 h半致死浓度(96 h LC50)为10.22 mg·L-1,安全浓度(SC)为1.02 mg·L-1;非离子氨的半致死浓度(96 h LC50)为0.16 mg·L-1,安全浓度(SC)为0.016 mg·L-1;高溶解氧条件下,氨氮对幼鱼的96 h LC50为12.68 mg·L-1,SC为1.27 mg·L-1;非离子氨96 h LC50为0.2 mg·L-1,SC为0.02mg·L-1。氨氮胁迫造成线纹海马幼鱼鳃组织在不同时间出现鳃丝血管扩张、泌氯细胞增生,鳃小片基部毛细血管破裂、红细胞溢出、鳃组织充血变性、卷曲变短、呼吸上皮细胞变性脱落等现象,并使肝脏肝细胞出现肿胀、细胞核肿大,肝血窦扩张、细胞轮廓模糊等组织变化;随着胁迫物浓度和胁迫时间增加,肝组织出现水样变性、空泡化、溶解,导致肝组织变得松散无序。综上,适当提高溶解氧能有效减轻氨氮对线纹海马幼鱼的毒性,超过阈值的氨氮胁迫会损害线纹海马幼鱼的鳃和肝脏组织结构。     

罗氏沼虾胸神经节中促肌肉蛋白质合成激素的初步分离

罗氏沼虾(Macrobrachium rosenbergii)成虾的胸神经节匀浆液,经Sephadex G-50柱层析所得的第2个峰,再经HPLC分离得到9个组分。把第2个组分的溶液注入罗氏沼虾幼虾体内,其肌肉蛋白质合成明显增加(P<0.01),这种促进蛋白质合成的能力随该溶液的蛋白质浓度的增加而增强。结果表明罗氏沼虾胸神经节能分泌促进虾肌肉生长的激素。该激素的分子量在3.4?kDa以下,可能是虾的生长激素。     

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