Effects of Radiographic Contrast Media on the Micromorphology of the Junctional Complex of Erythrocytes Visualized by Immunocytology

Effects of radiographic contrast media (RCM) application were demonstrated in vitro and in vivo where the injection of RCM into the A. axillaris of patients with coronary artery disease was followed by a significant and RCM-dependent decrease of erythrocyte velocity in downstream skin capillaries. Another study in pigs revealed that the deceleration of erythrocytes coincided with a significant reduction of the oxygen partial pressure in the myocardium—supplied by the left coronary artery—after the administration of RCM into this artery. Further reports showed RCM dependent alterations of erythrocytes like echinocyte formation and exocytosis, sequestration of actin or band 3 and the buckling of endothelial cells coinciding with a formation of interendothelial fenestrations leading to areas devoid of endothelial cells. Key to morphological alterations of erythrocytes is the membrane cytoskeleton, which is linked to the band 3 in the erythrocyte membrane via the junctional complex. Fundamental observations regarding the cell biological and biochemical aspects of the structure and function of the cell membrane and the membrane cytoskeleton of erythrocytes have been reported. This review focuses on recent results gained, e.g., by advanced confocal laser scanning microscopy of different double-stained structural elements of the erythrocyte membrane cytoskeleton.     

高粱糠不同存在形态酚类物质的AB-8大孔树脂纯化及对红细胞氧化溶血的保护作用

本文对提取得到的高粱糠不同存在形态酚类物质进行AB-8大孔树脂纯化,之后进行高效液相色谱分析及抗AAPH氧化溶血效果的测定。经AB-8大孔树脂纯化后,总酚含量依次为游离酚、束缚型酯型酚、束缚型苷型酚、可溶性苷型酚、可溶性酯型酚。而HPLC的分析结果显示,所检测到的18种酚类化合物的总量顺序依次是:束缚型酯型酚游离酚束缚型苷型酚可溶性酯型酚可溶性苷型酚。200μg/m L的游离型、束缚型和可溶型酯型酚可使AAPH溶血率降至约10%,接近阴性对照组,而可溶性苷型酚仍为28.84%。五类酚类物质的预处理使得AAPH损伤的人血红细胞内的MDA含量减少,GSH/GSSG升高,使红细胞恢复到正常状态;SOD、GSH-Px和CAT酶活力较弱的红细胞也受到了保护。综上,经AB-8大孔树脂纯化后的高粱糠不同存在形态酚类物质可以保护人血红细胞免受AAPH的损伤,其细胞内抗氧化活性与总酚含量和酚类化合物的组成有联系。     

咖啡酸的化学改性及产物抗氧化性的研究

以咖啡酸和氨基酸乙酯盐酸盐为原料,1-(3-二甲基氨基丙基)-3-乙基碳二亚胺盐酸盐(EDC)及1-羟基苯并三唑(HOBt)为催化剂,合成咖啡酰甘氨酸乙酯、咖啡酰丙氨酸乙酯、咖啡酰丝氨酸乙酯、咖啡酰苏氨酸乙酯4种产物。利用核磁共振氢谱(~1H NMR)和高效液相色谱-质谱(HPLC-MS)对产物结构进行表征,考察了咖啡酸化学改性产物对DPPH自由基及羟基自由基活性的抑制率及对红细胞膜的刺激性,并与咖啡酸单体进行了比较。结果表明,通过在咖啡酸中引入甘氨酸乙酯、丙氨酸乙酯、丝氨酸乙酯和苏氨酸乙酯后,4种咖啡酸酰胺类产物均呈现较好的抑制DPPH自由基、羟基自由基活性的效果;咖啡酰丝氨酸乙酯清除DPPH自由基能力较强,其IC_(50)值为13.5 μmol/L;咖啡酰丙氨酸乙酯清除羟基自由基能力较强,其IC_(50)值为0.214 mmol/L。红细胞溶血试验结果表明,4种咖啡酸酰胺类衍生物的红细胞溶血率均低于咖啡酸单体。     

兔血红细胞超氧化物歧化酶的纯化及其性质的研究

采用丙酮分级沉淀和ＤＥＡＥ－纤维素柱层析方法，从兔血红细胞中提取分离到高纯度的超氧化物歧化酶，琼脂糖凝胶电泳和醋酸纤维素薄膜电泳的均显示一条谱带，其等电点为ｐＨ＝４．８，最大紫外光吸收波长为２６２ｎｍ，比活力为５６６８ｕ／ｍｌＰｒｏｔ．浓度为１５ｕｇ／ｍＬ的酶溶液在５０℃放置３０ｍｉｎ，活力保持７６％，表明其热稳定性较高。     

Quantitative DNA measurements in an instrument combining scanning electron microscopy and light microscopy

An instrument for combined scanning electron microscopy (SEM) and light microscopy (LM) to which a photometer unit is attached is described. A special stage in the vacuum chamber of a scanning electron microscope incorporates light microscope optics (objective and condenser) designed for transmission and epi-illumination fluorescence LM. An optical bridge connects these optics to a light microscope, without objective and condenser. The possibility of performing quantitative DNA measurements in this combined microscope (the LM/SEM) was tested using preparations of either chicken erythrocytes, human lymphocytes, or mouse liver cells. The cells were fixed, brought on a cover-glass, quantitatively stained for DNA, dehydrated, and critical point dried (CPD). After mounting the cells were coated with gold. The specimens were brought into the vacuum chamber of the combined microscope and individual cells were studied with SEM and LM. Simultaneously DNA measurements were performed by means of the photometer unit attached to the microscope. It is shown in this study that DNA measurements of cells in the combined microscope give similar results when compared to DNA measurements of embedded cells performed with a conventional fluorescence microscope. Furthermore, it is shown that although the gold layer covering the LM/SEM specimens weakens the fluorescence signal, it does not interfere with the DNA measurements.     

一例肝衰竭婴儿外周血红细胞超微结构改变的电镜观察

目的：观察肝衰竭婴儿红细胞形态的超微结构变化。方法：采集一例肝衰竭婴儿的静脉血,制作扫描电镜和透射电镜样品观察红细胞的超微结构。结果：在扫描电镜下,该婴儿正常双凹圆盘形红细胞数百分比仅为2.5%,而泪滴形、靶形、口形、网织红细胞、刺形、棘形和椭圆形等多种异常形态的红细胞却高达红细胞总数的97.5%。在透射电镜下,网织红细胞和少数成熟红细胞切面具有棒状突起,突起分枝或不分枝,甚至形成了高度曲折凹陷的迷宫图形。结论：该例肝衰竭婴儿红细胞形态从外形到内部超微结构均有显著改变,提示红细胞形态多样性可能与病情复杂和严重程度有关。     

Investigation of chromatin folding patterns by atomic forcemicroscopy

1IntroductionTounderstandthemechamsmsinvolvedingeneexpressionandinthestructuralorgAnzationofchlomatinineukaryoticnucleus,manyeffortshavebeendevotedtoinvestigatethestructuraldetailsofchromatinfoldingpatternsatthedifferentlevels.Amongalloftheusedmethods,theelectronmicroscopy(EM)hasbeenprovedtobeveryusefulinrevealingchromatinstructuraldetails.Somechromatinfoldingpatterns,suchasnucleosomes[1-3],30urnchlomatinfib..,[4]560-80urnchromatinfibersand100-130runcblomonemafibers[5'6]wererevealed,and200-40…     

乌骨鸡红细胞超氧化物歧化酶的分离纯化及部分性质的研究

经氯仿-乙醇分级分离，丙酮沉淀及DE-32纤维素柱层析的方法，从乌骨鸡红细胞中得到纯化的Cu，Zn-SOD。结果表明此酶的比活力为11，954U／mg，提纯倍数为334．71，聚丙烯酰胺凝胶电泳蛋白带与活性带相对应。相对分子量约为32，000，相对亚基分子量约为16，000。最大紫外吸收波长为260nm，对KCN和H2O2敏感，最适pH为6～9，热稳定性在60℃以下。