Hemolysis of Erythrocytes and Erythrocyte Membrane Fluidity Changes by New Lysosomotropic Compounds

This work contains the results of studies on the influence of newly synthesized lysosomotropic substances (lysosomotropes) on human erythrocytes. Six homologous series of the compounds differing in the alkyl chain length and counterions were studied. They were found to hemolyse erythrocytes and to change their osmotic resistance. The observed hemolytic effects were dependent both on the compounds structure (polar head dimension and alkyl chain length of compound) and its form (the kind of the counterion). In parallel, the influence of lysosomotropes on fluidity of the erythrocyte membrane was studied. Three different fluorescent probes were used; 1,6-diphenyl-1,3,5-hexatriene (DPH), 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene, p-toluenesulfonate (TMA-DPH) and 6-dodecanoyl-2-dimethylaminonaphthalene (laurdan). Their anisotropy (DPH and TMA-DPH) or general polarization (laurdan) values after incorporation into ghost erythrocyte membranes were measured. The results obtained show that fluidity changes accompanied the effects observed in hemolytic experiments both quantitatively and qualitatively.     

Radioprotection on nucleated and anucleated erythrocytes by oxide-reduction coenzymes

The protective effects of NAD, FAD and Quinone and mixtures of these compounds were studied on gamma irradiated rabbit and chicken erythrocytes. The dose relative factor (DRF 37) was evaluated by visible absorbancy measurements of liberated hemoglobin. The DRF 37 obtained on rabbit erythrocytes were : NAD+FAD+Quinone mixture : 11,1; NAD+Quinone mixture : 6,1; FAD+Quinone mixture : 6,1; NAD: 1,6; FAD: 5,5; Quinone: 5,1. The DRF 37 obtained with the mixture NAD+FAD+Quinone on chicken erythrocytes was 3,9. The high efficiency of the radioprotective mixture NAD+FAD+Quinone is discussed.     

Biophotonics of the interaction of low-intensity laser radiation with blood erythrocytes

We have studied experimentally how optical radiation affects the neutralization of the toxic action of heavy metals and harmful chemical compounds (ecotoxicants) on the oxygen-transport function of blood erythrocytes. It has been found that the optical radiation has a stabilizing effect and prevents lowering the erythrocyte concentration in the presence of phenol and heavy metals in blood. We have studied the neutralization efficiency of the toxic action of ecotoxicants in relation to the laser irradiation time. The obtained data on the effect of the laser radiation on the thermal denaturation of hemoglobin and erythrocytes yield the scientific substantiation to the development of the optical method for the use in medicine upon drawing and conserving donor blood. We have shown that the obtained data can be used in medicine for improving the reliability of conditions of conservation and storage of donor blood, as well as for preventing the toxic action of harmful chemical compounds in the environment.     

Simple and facile approach to synthesize magnetite nanoparticles and assessment of their effects on blood cells

In this paper, a very simple and facile approach for the large scale synthesis of uniform and size-controllable single-domain magnetite nanoparticles is reported. These magnetite nanoparticles were synthesized via thermal decomposition of a ferric nitrate/ethylene glycol solution. The structural and morphological properties of the synthesized nanoparticles were carefully studied. Nearly spherical nanoparticles with inverted spinel structure and average particle and crystallite sizes smaller than 20 nm were obtained. The magnetic measurements revealed that magnetite nanoparticles have a magnetic saturation value near that of the bulk magnetite. The erythrocyte cytotoxicity assays showed no hemolytic potential of the samples containing magnetite nanoparticles, indicating no cytotoxic activity on human erythrocytes, which makes these interesting for biotechnological applications.     

Effect of chemical additives on the performance of Na/NiCl2 cells

The effect of chemical additives on the performance of sodium/nickel chloride cells was investigated in quasi-sealed laboratory research cells. The performance of these cells was measured by galvanostatic and galvanodynamic methods. It was observed that the use of sodium bromide, sulfur, sodium iodide, and a combination of these additives enhance the performance of the Na/NiCl₂ cells by reducing the area-specific impedance of the nickel chloride electrode. Improved morphology by the use of the poreformer further improves the nickel utilization and the electrode impedance. The performance enhancement is attributed to the chemical and morphological modifications of the nickel chloride electrode in the Na/NiCl₂ cells.     

Mediated trehalose un-loading for reduced erythrocyte osmotic fragility and phosphatidylserine translocation

Recently, high concentrations of intracellular trehalose (>200mM) were employed to enhance the cryoprotection and desiccation protection of human erythrocytes. However, significant challenges must be overcome if this advancement is to be translated into clinical practice. It is here demonstrated that 247 ± 5 mM intracellular trehalose caused the lysis of 60 ± 2 percent of erythrocytes upon resuspension in PBS of physiological osmolality (300 mOsm) and caused surviving cells to swell up to 140 ± 2 percent of isotonic cell volume. Trehalose loaded cells also exhibited 24 ± 1 percent incidence of phosphatidylserine translocation upon resuspension in 300 mOsm PBS, likely due to loading induced cell swelling. Un-loading of trehalose from erythrocytes using the membrane-permeabilizing biopolymer PP-50 was investigated as a technique to mitigate these damaging effects. After erythrocyte un-loading from 247 ± 5 mM to 39 ± 2 mM intracellular trehalose, cell lysis at 300 mOsm PBS was reduced from 60 ± 2 percent to 17 ± 3 percent. Un-loading also reduced cellular incidence of PS translocation in resuspended cells from 24 ± 1 percent to 13 ± 1 percent.     

Sodium 1, 4‐dihydroxy‐9, 10‐anthraquinone‐ 2‐sulphonate interacts with calf thymus DNA in a way that mimics anthracycline antibiotics: an electrochemical and spectroscopic study

The anthracycline drugs, adriamycin and daunorubicin, efficient in the treatment of various human cancers, form strong intercalation complexes with DNA. The therapeutic efficiency and toxic properties of the drugs are associated with electron transfer processes, which correlate well with the redox behaviour of the compounds. Sodium 1,4‐dihydroxy 9,10‐anthraquinone‐2‐sulphonate (sodium quinizarin‐2‐sulphonate, NaLH₂) (Na‐Qz‐2S) is a molecule that resembles anthracycline drugs and has a simpler structure in comparison to these drugs. Two electrons in the course of chemical action reduce this molecule like the anthracyclines. Electrochemical methods were used to identify this process. UV‐Vis and fluorescence spectroscopy were used to analyse binding of the compound to calf thymus DNA. The binding constant and site size were evaluated for Na‐Qz‐2S and the same compared to that of the anthracyclines. Such comparisons are essential in order to understand whether the simpler hydroxy‐anthraquinones can be a substitute for anthracycline drugs in cancer chemotherapy. Copyright © 2009 John Wiley & Sons, Ltd.     

Triboluminescence and the mechanism of discharge of gases between the newly-created surfaces of crystals during their fracture

The present paper reports on the mechanism of discharge of the gases between the newly-created surfaces of sugar, tartaric acid and six other crystals during their fracture. It has been shown that the TBL intensity obtained by crushing the crystals inside ths liquid, anhydrous diethylether, diminishes more considerably than when they are crushed in air but it depends on the mode of mechanical crushing in the same manner as the TBL intensity obtained by crushing the crystals in air does. The TBL intensity obtained by crushing the crystal inside the liquid is higher for those crystals which show higher TBL when crushed in air. It has been concluded that some part of TBL is due to the excitation of the TBL centres and the remaining part to the discharge of the gases between the newly-created surfaces, to the exo-emission of the electrons from the TBL centres at the instant of fracture of the crystal.Thanks are due to Dr. J. N.Das, Professor and Head of the Physics Department, Government Science College, Raipur (M. P.) India for his guidance and help. The author also wishes to thank the Director-General, C. S. I. R. New Delhi, for the award of a Post-Doctoral Fellowship during the tenure of the work.     

Comparative effects of macro-sized aluminum oxide and aluminum oxide nanoparticles on erythrocyte hemolysis: influence of cell source,temperature, and size

Al₂O₃ is the most abundantly produced nanomaterial and has been used in diverse fields, including the medical, military, and industrial sectors. As there are concerns about the health effects of nanoparticles, it is important to understand how they interact with cells, and specifically with red blood cells. The hemolysis induced by three commercial nano-sized aluminum oxide particles (nanopowder 13 nm, nanopowder <50 nm, and nanowire 2–6 × 200–400 nm) was compared to aluminum oxide and has been studied on erythrocytes from humans, rats, and rabbits, in order to elucidate the mechanism of action and the influence of size and shape on hemolytic behavior. The concentrations inducing 50 % hemolysis (HC₅₀) were calculated for each compound studied. The most hemolytic aluminum oxide particles were of nanopowder 13, followed by nanowire and nanopowder 50. The addition of albumin to PBS induced a protective effect on hemolysis in all the nano-forms of Al₂O₃, but not on Al₂O₃. The drop in HC₅₀ correlated to a decrease in nanomaterial size, which was induced by a reduction of aggregation. Aluminum oxide nanoparticles are less hemolytic than other oxide nanoparticles and behave differently depending on the size and shape of the nanoparticles. The hemolytic behavior of aluminum oxide nanoparticles differs from that of aluminum oxide.     

Atomic force microscopy observation of peroxynitrite-induced erythrocyte cytoskeleton reorganization

Atomic force microscopy (AFM) was used to study surface layers of fixed intact erythrocytes. Advantages of simultaneous analysis of surface topography and lateral force maps in the investigation of cytoskeleton structure were shown. Fractal analysis was applied to the lateral force maps of erythrocyte surfaces to evaluate the complexity of the cytoskeleton. Peroxynitrite was used as an oxidant to induce changes in the cytoskeleton structure of intact erythrocytes. Peroxynitrite action on whole blood leads to local abnormalities in the erythrocyte cytoskeleton structure, as well as cytoskeleton reorganization in protruded regions of crenated erythrocytes.     

Photothermal biological effects of monomeric erythrocyte using optical tweezers

The changes of mechanical properties and biological activities of monomeric erythrocytes are studied using optical tweezers micromanipulation technology. Firstly, the mechanical properties of irradiated erythrocyte membranes are obtained. Weaker power laser irradiation can delay the decay of the mechanical properties of erythrocytes and promote the biological activity of erythrocytes, while higher power laser irradiation damages erythrocytes. The stronger the laser irradiation is, the more obvious and rapid the damage will be. The temperature of the cell surface will be changed by regulating the laser power and irradiation time, so the biological functions of erythrocyte can be controlled. Secondly, the finite element simulation of the temperature change on the cell surface under the condition of laser irradiation is carried out using simulation software, and the precise temperature of the cell surface irradiated cumulatively by a laser with different powers is obtained. Finally, the processes of abscission, unfolding, and denaturation of hemoglobins in erythrocytes at different temperatures due to the photothermal effect are analyzed using the model. The mechanism of laser irradiation on the elasticity of erythrocyte membranes is also obtained.     

Light scattering by erythrocytes under conditions of osmotic imbalance in a cell-surrounding medium system

A model for changes in the sizes of erythrocytes under conditions of osmotic imbalance in a hypoosmotic medium is proposed assuming free diffusion of water through the erythrocyte membrane. Equations relating the minimum and maximum osmotic resistances to the shape of an erythrocyte in an isotonic medium are obtained. A numerical simulation is used to determine how the optical attenuation coefficient varies as a result of the swelling and hemolysis of erythrocytes; this provides a foundation for a new optical method for determining the osmotic resistance of erythrocytes. This method does not require exerting a force on the erythrocytes, is distinguished by simplicity and high speed, and can be implemented using standard spectrophotometers.     

Excited‐state structural dynamics and vibronic coupling of 1,3‐dithiole‐2‐thione—resonance Raman spectroscopy and density functional theory calculation study

1,3‐Dithiole‐2‐thione (DTT) was synthesized and characterized using NMR, FT‐Raman, FT‐IR, UV spectroscopies. Resonance Raman spectra (RRs) were obtained with 341.5, 354.7 and 368.9 nm excitation wavelengths and density functional calculations were done to elucidate the electronic transitions and the RRs of DTT in cyclohexane solution. The RRs indicate that the Franck‐Condon region photodynamics is predominantly along the CS stretch+ H‐CC‐H scissor υ₄, accompanied by the H‐CC‐H scissor υ₃, S‐C‐S symmetric stretch υ₆, CC stretch υ₂, and overtone of the non‐totally symmetric SC‐S2 out‐of‐plane deformation 2υ₁₁. The excited‐state dynamics and the force constant of CS stretch calculated by the RRs were discussed. Copyright © 2009 John Wiley & Sons, Ltd.     

Pressure-induced hemolysis of in vivo aged human erythrocytes is enhanced by inhibition of water transport via aquaporin-1

Human erythrocytes are fractionated into young, intermediate, and old cells according to their densities. Pressure-induced hemolysis reflects sensitively membrane perturbations. Therefore, the hemolysis of erythrocytes at 200 MPa was examined using fractionated cells. Pressure-induced hemolysis of old (or in vivo aged) erythrocytes was enhanced, compared with those of young and intermediate cells which showed the same hemolytic values. Flow cytometric analysis showed less fragmentation of old erythrocytes under pressure. Moreover, the water transport through the membrane was suppressed in old erythrocytes than intermediate ones. The low permeability of water in old erythrocytes was confirmed by osmotic hemolysis using a hypotonic buffer. These results suggest that water transport via aquaporin-1 (AQP1) is inhibited in old erythrocytes. As the number of AQP1 molecules remained constant in old erythrocytes, the function of AQP1 may be reduced.     

4-氨基-4'-氯二苯甲酮的合成及光谱表征

对硝基苯甲酰氯和氯苯在无水三氯化铝催化下 ,生成 4 硝基 4’ 氯二苯甲酮。以二硫化钠为还原剂 ,将其还原成重要有机中间体 4 氨基 4’ 氯二苯甲酮。通过多因素正交实验 ,确定了最佳工艺条件为 :反应温度 92℃ ,反应时间 2 5h ,4 硝基 4’ 氯二苯甲酮 :Na2 S2 =1∶1 7(mol) ,回收率为 85 80 % ,纯度为98 0 8% ,熔点 177～ 179℃。采用元素分析 ,1H ,13 C核磁共振波谱 ,红外光谱及质谱法表征了目标化合物的分子结构 ,并对化合物红外光谱吸收峰及核磁谱带进行了归属分析。阐明了质谱主要碎片离子的裂解途径。此研究可为无致癌性的禁用染料中间体替代品开发提供依据。     

生物发光法测定红细胞膜Na+,K+-ATPase活性及其在心血管疾病中的临床应用

本文以生物发光新技术检测了32例心血管病人在钾负荷试验前后的红细胞膜Na+,K+-ATPase活性,结果钾负荷试验阴性病人,冠心加高心组及心肌病变较生的病人,钾负荷后红细胞膜Na+,K+-ATPase活性显著降低(P<0.05),提示心肌功能与Na+,K+-ATPase有内在联系.     

微通道内红细胞流动与变形的可视化研究

微循环条件下,红细胞的尺寸与血管相近,血液不能视为均质流体,其流动表现出较强的颗粒性,红细胞流变特性对血液流动有较大影响。本文使用高倍显微镜对微流控芯片矩形截面微通道内红细胞的流动和变形特性进行可视化观察研究,并使用高速CCD相机拍摄和捕捉了红细胞在微通道内的流动和变形过程。通过观察不同浓度、粘度和速度下红细胞的聚集性、变形性以及常见的运动形态,发现红细胞在低粘度、低速流动条件下表现为两面凹圆盘形,沿流动方向运动过程总是伴随着翻转与旋转;在高粘度、高速运动条件下,红细胞表现为扁平椭圆形、呈坦克履带式(TTM)前进。     

Surface crystallography of rubidium on Ag(111), and the chemical reactivity of nitric oxide on rubidium-dosed silver

Rubidium chemisorbs amorphously on Ag(111) at coverages below one monolayer, but ordered structures are formed in the multilayer regime. For thin layers the Rb grows as an fcc crystal, but above a certain critical thickness a phase transition occurs to yield the ordinary bcc form. The reactivity of Rb-dosed Ag towards NO is examined and compared with earlier work on Ag/Na. Although there are broad similarities between the two systems, certain important differences in chemical behaviour are found. These are mainly the result of reduced penetration of the Ag lattice by Rb, and the very greatly reduced surface → bulk transport of chemisorbed oxygen as compared with the case of Na. Evidence is also found for the formation of surface compounds between Rb, O, and N on Ag(111), and auxilliary experiments with O₂ and N₂O are carried out in an attempt to shed further light on the nature of these compounds.     

多孔PMP聚合物薄膜微结构控制

将二氧化硅(SiO2)微球为模板材料分散在聚-4-甲基-1-戊烯(PMP)溶液中,通过对流自组装方法将其涂覆于基片上,经过热致相分离(TIPS)过程形成含SiO2微球模板的PMP薄膜,然后通过氢氟酸(HF)溶液腐蚀除去SiO2微球,获得了具有规则多孔结构的PMP聚合物薄膜。采用扫描电子显微镜(SEM)对含SiO2微球的PMP薄膜以及除去SiO2微球后的PMP多孔薄膜的微结构进行了表征。研究结果表明:SiO2微球在聚合物中呈有序排列,腐蚀除去SiO2微球后PMP薄膜有效复制了SiO2微球形成的有序结构,形成了有序多孔PMP薄膜。     

Study of optical and nanostructural metal-induced changes in erythrocyte membranes by scattering and atomic force microscopy

The surface topography of erythrocyte membranes is studied by atomic force microscopy. Differences in fine structure of membranes are found. The structure of profiles of erythrocyte membranes modified by metals is smoother compared to unmodified erythrocytes. The autocorrelation function of irregularity pro-files of erythrocyte membranes and its parameter (the correlation length) are informative parameters of the action of toxic metals on the erythrocyte membrane surface. The content of metal in an erythrocyte membrane is determined from optical investigations of a suspension of membranes subjected to the action of lead and zinc ions. It is revealed that the luminescence of erythrocyte membranes is enhanced compared to reference data. The absorption spectra of erythrocyte membranes in the range 325–740 nm are calculated from the diffuse transmission and reflection coefficients of samples taking into account their luminescence. The possibility of determining the content of metals in erythrocyte membranes from optical measurements is demonstrated.