高胆固醇血兔红细胞变形能力的改变及其防治

本实验利用激光衍射法研究正常家兔和高胆固醇血兔的红细胞变形能力及衍射图的改变。结果表明：高胆固醇血兔在喂胆固醇粉４周后其红细胞的变形能力和红细胞衍射图开始发生明显改变。血清胆固醇水平增加所引起的脂质过氧化产物的异常增高和脂质过氧化作用致使红细胞膜硬度的增加是导致红细胞变形能力恶化的重要原因。由于黑茶的抗氧化和阻断脂质过氧化物连锁反应的作用,口服黑茶可以有效地改善红细胞的变形能力。     

阿托伐他汀+葡萄籽原花青素预防兔动脉硬化的实验研究

目的:对阿托伐他汀联合葡萄籽原花青素预防兔动脉硬化的效果进行调查。方法:采用电化学发光法对家兔甘油三酯、总胆固醇、低密度脂蛋白固醇、高密度脂蛋白固醇水平进行检测,并采用硫代巴比妥酸法对家兔血清丙二醛含量进行检测。结果:实验前四组家兔的胆固醇、甘油三酯、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇比较无明显差异,P0.05。实验后4组家兔胆固醇、甘油三酯、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇比较存在明显差异,且2组家兔所有指标增长幅度均要明显高于3组、4组。结论:阿托伐他汀联合葡萄籽原花青素能够有效降低兔动脉硬化斑块的发生率。     

重组人可溶性凝血酶调节蛋白对单核细胞源性泡沫细胞形成的影响

目的:研究可溶性凝血酶调节蛋白(Soluble thrombomodulin,sTM)结合的血浆低密度脂蛋白对细胞胆固醇代谢的影响,探索sTM参与或影响动脉粥样硬化发病过程的初步机制。方法:以THP-1巨噬细胞为模型,通过油红O染色、高效液相色谱检测胆固醇含量等方法,以体外重组人可溶性凝血酶调节蛋白结合的低密度脂蛋白(sTM-LDL)作用于巨噬细胞,观察sTM-LDL对细胞胆固醇代谢的影响。结果:研究发现:正常人LDL对细胞内胆固醇代谢影响较小;而sTM-LDL处理细胞72小时后,细胞内大量脂滴形成,细胞内胆固醇含量明显增多,符合典型泡沫细胞的特征;运用NH-1单抗中和／干扰sTM的作用,不能阻断sTM-LDL诱导的THP-1细胞内胆固醇聚集。结论:sTM对LDL的修饰可能改变了LDL的理化特性和代谢途径,可导致细胞内胆固醇聚集和泡沫细胞的形成,且这种作用与sTM本身对细胞的影响可能无明显关系。     

莲房原花青素对家兔血脂及肝组织形态的影响

目的：观察莲房原花青素（LSPC）对实验性高血脂兔及其肝组织形态学的影响。方法：按血胆固醇水平将实验性高血脂兔随机分组：空白对照组,三个不同LSPC剂量（100,200,400mg/kg）组,测定口服LPSC前后血清和肝总胆固醇（TC）、甘油三酯（TG）、血清低密度脂蛋白－胆固醇（LDL－C）、高密度脂蛋白－胆固醇（HDL－C）等指标,并对家兔肝脏进行病理学检查。结果：低剂量LSPC能明显降低高血脂兔的血清及肝脏中TG（P＜0．05）,显著升高血清HDL－C值（P＜0．01）;高剂量LSPC能显著减少高血脂兔血清TC、LD1－C（P＜0．01）,同时升高血清HDL－C值（P＜0．05）,但对肝组织形态有一定的副作用。结论：结论：提示莲房原花青素可能具有调节血脂的作用。     

果蝇视锥细胞聚集形态形成机理的研究

果蝇视锥细胞聚集形态与液态泡沫一致, 视锥细胞N-钙黏附分子间的黏附力可以类比为泡沫的表面张力. 把果蝇视锥细胞排布近似为两维由等同气泡组成的约束边界液态泡沫, 采用两维液态泡沫动力学模型模拟了2~6个视锥细胞稳定聚集形态的形成过程, 提出了在视锥细胞面积恒定的情况下周长达到极小值时(即表面能量极小)细胞即达到稳定聚集的假设, 在此假设基础上确定的排布方式与文献[4]报道的实验观测完全一致, 并预报了一个更稳定的6细胞聚集形态; 计算表明, 果蝇视锥细胞稳定聚集时, 表面能与细胞个数成正比     

高胆固醇血症家兔红细胞在交、直流电场中的电泳行为

本文对高胆固醇血症家兔红细胞在交、直流电场中的电泳行为进行了多指标测定,结果显示,高脂组与正常组相比红细胞聚集能力增强,变形能力及膜流动性下降,表明高脂血症可能较易导致血栓形成。中药有效成分8501有对抗高脂引起的红细胞上述改变的作用,提示8501可能对血栓和动脉粥样硬化斑块形成有防治作用。     

家兔解剖教学中的几个问题

家兔在生物学和医学科学研究中是常用的实验动物,在教学上又常作为哺乳纲的代表动物。当前中学动物学教学中家兔的内容较多,又有实验,现就兔体形态结构中的某些特点及     

三七茎对家兔实验性高脂血症的影响

目的:探究三七茎对家兔实验性高脂血症的影响。方法:将家兔随机分为4组,除对照组外,其余组加喂猪油和胆固醇,并对低剂量组和高剂量组喂以不同剂量的三七茎,利用酶学终点法于给药前和给药后2,4,6周测定其TC、TG、HDL-C、LDL-C值。结果:与对照组比较,高脂组家兔的TC、TG、LDL-C值升高,HDL-C值降低,差异有统计学意义(P<0.05)。与高脂组比较,低剂量组和高剂量组的TC、TG、LDL-C值降低,HDL-C值升高,差异有统计学意义(P<0.05)。结论:三七茎对实验性高脂血症家兔具有降血脂作用。     

氧化低密度脂蛋白诱导主动脉平滑肌细胞胆固醇酯聚集和凋亡(英)

细胞内胆固醇代谢的失衡和细胞凋亡都与动脉粥样硬化的发生有关.为了研究两者之间的关系,我们把猪的主动脉平滑肌细胞与15 mg／L氧化低密度脂蛋白共同孵育72 h,发现细胞内胆固醇酯与总胆固醇的比值由26.2%增加到64.1%,并且细胞内胆固醇酯的积聚有剂量依赖关系,表明细胞已经转化为平滑肌源性的泡沫细胞.另外,使用荧光显微镜、激光共聚焦显微镜和流式细胞仪分别发现,与氧化低密度脂蛋白共孵育的细胞有典型的凋亡形态改变.从实验可以推测,由氧化低密度脂蛋白诱导的平滑肌细胞凋亡,除了低密度脂蛋白氧化的因素外,也可能与细胞内胆固醇酯与总胆固醇的比值升高有关.     

绞股蓝对高脂血症致成年雄性兔睾丸显微结构损害的干预作用

目的观察绞股篮和高脂血症对成年雄性兔睾丸显微结构的影响。方法40只日本雄性大耳白兔随机分为A组、C组、D组、E组,分别喂饲高脂饲料＋绞股蓝5g,kg、高脂饲料、标准饲料＋绞股篮5g／kg、标准饲料。饲养前和饲养后3周、6周、9周末检测三酰甘油（TG）、胆固醇（TC）、低密度脂蛋白胆固醇（LDL-C）、高密度脂蛋白胆固醇（HDL-C）。实验结束观察睾丸显微结构。结果①TG、TC、LDL-C、HDL-C：A组、C组随饲养时间延长,TG、TC、LDL-C渐升,与饲养前比较有显著差异（P〈0．05）,A组HDL-C渐升,与饲养前比较有显著性差异（P〈0．01）;饲养后A组TG、TC、LDL-C低于c组,A组HDL-C高于C组,饲养后组间比较有显著差异（P〈0．05）。②光镜检查：A组、D组、E组生精细胞正常;C组睾丸生精细胞脂肪变性,间质纤维化,基底膜增厚,精子细胞数量下降。结论高脂血症导致睾丸生精细胞脂肪样变,精子细胞数量下降。绞股蓝通过降低血脂、改善血脂代谢,对高脂血症导致的睾丸生精细胞脂肪样变具有抑制作用。绞股篮对标准饲料饲养兔睾丸显微结构无影响。     

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     

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.