适合于植物花器官的冰冻切片技术

通过对4种植物主要花器官冰冻切片技术的各个环节及参数的研究,建立了一种适合于植物花器官的冰冻切片技术,即蔗糖保护-液氮速冻-冰冻切片法。其具体程序是：材料经固定和冷冻保护(蔗糖为冷冻保护剂)后进行速冻包埋(液氮为包埋剂);尔后进行冰冻切片;切片经干燥和染色(或者不染色)后,在显微镜下观察并摄影。此法为植物花器官的细胞生物学和分子生物学研究提供了简便、快速和高效的切片技术。     

植物冰冻切片条件的优化及其与石蜡切片在组织化学应用中的比较

冰冻切片是植物组织学研究中一项重要的实验技术,冷冻温度和冷冻时间是决定切片质量的关键因素。通过比较15种冰冻切片条件,得出植物组织直接冰冻切片较适宜的冷箱温度、冷台温度和冷冻时间。同时,通过对5种植物的不同组织进行组织化学染色,比较了新鲜材料直接冰冻切片与常规石蜡切片在不同化学成分鉴定上的异同及各自的适用范围。结果表明,对于多糖、蛋白质和角质,两种切片方法的鉴定结果比较一致,但对于脂肪只能采用冰冻切片技术。研究结果对植物组织学实验和研究方法的改进具有一定的参考价值。     

少量贴壁培养细胞电镜原位包埋方法的探讨

该文探讨了对少量贴壁培养细胞较易操作且能保存较好超微结构的透射电镜样品包埋的方法。将Hela细胞分为三组:(1)不使用环氧丙烷,将树脂胶囊直接倒扣包埋于塑料培养皿;(2)不使用环氧丙烷,将细胞爬片倒扣包埋于胶囊;(3)使用环氧丙烷并将细胞爬片倒扣包埋于胶囊。将三组带有细胞的树脂胶囊进行超薄切片,电镜观察后发现,第一种方法包埋简便,超薄切片上无细胞缺失孔洞,且超微结构保存较好。     

碱性磷酸酶钙-钴法染色的不同包埋方法比较

目的探讨石蜡切片、冰冻切片及碳蜡(聚乙二醇)包埋切片在碱性磷酸酶染色中的应用,综合分析几种组织处理方法的优缺点,以便在病理诊断及科研工作中能找到更适合的碱性磷酸酶染色方法。方法取新鲜乳腺组织及肝组织,每份标本各取3块组织,根据包埋方法的不同,分为3组:石蜡切片碱性磷酸酶染色、冰冻切片碱性磷酸酶染色、碳蜡包埋切片碱性磷酸酶染色。结果 3组切片均可见黑色碱性磷酸酶的存在,其中肝组织内显示碱性磷酸酶呈黑色,沿胆小管分布;乳腺组织内显示碱性磷酸酶呈黑色沉淀弥漫分布于乳腺间质中。结论碳蜡包埋切片在碱性磷酸酶染色中,具有冰冻切片和石蜡切片的优点,并弥补了常规冰冻切片和石蜡切片染色的缺点和局限性,在病理诊断及科研工作中具有一定的应用价值。     

高度木质化材料的冰冻切片技术

高度木质化植物材料的切片难度很大,应用常规切片方法不容易取得高质量的图版。本文介绍的冰冻切片方法,不需要进行长时间的软化处理、以及繁琐的脱水、包埋等过程,切片还进行不同的染色或组织化学测定,是一种快速、简捷和有效的制片方法。 其关键步骤是选好甘油浓度, 冰冻温度和展片步骤。     

微小组织冰冻快速制片技术

目的摸索提高微小组织冰冻快速制片质量的方法。方法针对小组织冰冻切片中常常出现组织切完、多粒组织切片不全、冰晶、染色不均匀等问题,采用预先制作冷冻平台、快速冷冻等方法来制作优质的冰冻切片。结果组织铺平可使组织切片完整,快速冷冻可减少冰晶形成,使组织结构更清晰,及时固定和加温染色可使细胞核染色更鲜艳,核、质对比明显。结论组织铺平、速冻、固定、染色等都是提高微小组织制片质量的关键。     

盐生肉质草本植物海马齿叶片石蜡切片简易方法

海马齿是海边盐生肉质草本植物,由于叶片的肉质化,传统石蜡切片制作路线不能制作出结构完整,效果较好的切片.本实验以传统的石蜡切片方法为基础,在固定方法选择,脱水时间控制,包埋温度,染色等方面做了适合海马齿叶片特点的改良,固定方法采用戊二醛固定液固定24 h,并洗脱;脱水每级梯度时间为1 h,包埋温度在100℃,染色方法采用固绿染色法.结果表明:采用这种改良的方法可以制作出染色清晰,组织结构完整的海马齿叶片切片.这对其它肉质化植物的石蜡切片制作有着借鉴作用.     

高度木质化材料的冰冻切片技术

高度木质化植物材料的发片难度大,应用常规切片方法不容易取得高质量的图版。本文介绍了冰切片方法,不需要进行长时间的软化处理、以及繁琐的脱水、包埋等过程,切片还进行不同的染色或组织化学测定,是一种快速、简捷和有效的制片方法。其关键步骤是选好甘油浓度,冰冻温度和展片步骤。     

三种不同脂肪染色方法的比较

目的探讨碳蜡(聚乙二醇)包埋技术、冰冻切片及饿酸染色在脂肪染色中的应用,综合比较几种方法的优缺点,以便在病理工作及科研工作中能找到更适合的脂肪染色方法。方法取新鲜脂肪组织及肝组织,每份标本各取3块组织,分为A、B、C三组:A组和B组标本分别进行碳蜡包埋切片和常规冰冻切片,油红O法染色;C组以饿酸浸染组织块后进行石蜡包埋切片及眦复染。结果 A组切片脂肪滴呈红色,细胞核呈蓝色;B组切片脂肪滴呈红色,细胞核呈蓝色;C组切片脂肪滴呈黑色。结论饿酸染色和碳蜡包埋技术在脂肪染色中,具有冰冻切片和石蜡切片的优点,弥补了常规冰冻切片脂肪染色的缺点和局限性,在病理检验及科研中具有一定应用价值。     

果蝇胚胎石蜡切片制作方法的改良

探索一种不用在卵壳上手工打孔、适用于果蝇胚胎石蜡切片制作的方法。实验前期对果蝇胚胎进行渗透化处理,后期用琼脂糖、明胶、石蜡3种包埋辅佐剂对胚胎进行聚集、包埋、切片,最后进行HE及PASM染色。渗透化处理后的胚胎用琼脂糖或石蜡聚集并包埋后所制切片HE染色均显示胚胎形态结构正常,背景干净,而琼脂糖聚集法所制切片PASM染色背景呈灰色,明胶聚集法所制切片HE染色和PASM染色背景均显杂色且胚胎出现形变。3种包埋辅佐剂中,琼脂糖和石蜡均适于果蝇胚胎结构的保存,石蜡聚集法所制切片2种染色背景均无杂色,因此最适合做包埋辅佐剂。渗透化处理和石蜡聚集法结合后的改良方法适合于大样本且高脂含量的果蝇胚胎石蜡切片的制备。     

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.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细