Rosette formation of tumor cells with concanavalin A treated erythrocytes

Summary Trypsinized human erythrocytes were incubated with concanavalin A at 4°C. After removal of free concanavalin A, the erythrocytes were incubated with Ehrlich ascites tumor cells at 37°C. The erythrocytes formed rosettes with the tumor cells.     

An increase in Sendai virus-induced cell fusion of erythrocytes infected with Plasmodium chabaudi

The extent of cell fusion induced by Sendai virus was examined in erythrocytes infected with Plasmodium chabaudi. An increase in cell fusion of erythrocytes with Ehrlich tumor cells and of erythrocytes with erythrocytes was observed with the infected erythrocytes. However, agglutination by the virus was not changed between erythrocytes of normal and malarial mice. These results indicate that the increase in cell fusion occurred in the process of membrane fusion, suggesting that some membrane property of Plasmodium-parasitized erythrocytes is changed in terms of Sendai virus-induced cell fusion.     

An increase in Sendai virus-induced cell fusion of erythrocytes infected withPlasmodium chabaudi

Summary The extent of cell fusion induced by Sendai virus was examined in erythrocytes infected withPlasmodium chabaudi. An increase in cell fusion of erythrocytes with Ehrlich tumor cells and of erythrocytes with erythrocytes was observed wit the infected erythrocytes. However, agglutination by the virus was not changed between erythrocytes of normal and malarial mice. These results indicate that the increase in cell fusion occurred in the process of membrane fusion, suggesting that some membrane property ofPlasmodium-parasitized erythrocytes is changed in terms of Sendai virus-induced cell fusion.We thank Drs George L. Gerton, T. Matsuyama and M. Niwa for their comments on this work and Mr I. Kimata for preparing photographs.     

Immuno-electronmicroscopic study of human EA rosettes

Summary The immuno-electronmicroscopic study of human EA rosettes, using ferritin-labelled anti-human IgG antiserum, showed clusters of ferritin granules at the points of contact between erythrocytes and lymphoid cells, indicating that the links between Fc fragment of IgG on the surface of erythrocytes and specific receptor on the surface of lymphoid cell correspond to the sites of morphological interaction between the 2 cell types.recipient of a Grant of the Italian Consiglio Nazionale Ricerche.     

Immuno-electronmicroscopic study of human EA rosettes.

The immuno-electronmicroscopic study of human EA rosettes, using ferritin-labelled anti-human IgG antiserum, showed clusters of ferritin granules at the points of contact between erythrocytes and lymphoid cells, indicating that the links between Fc fragment of IgG on the surface of erythrocytes and specific receptor on the surface of lymphoid cell correspond to the sites of morphological interaction between the 2 cell types.     

Agglutination of leukemic cells and daunomycin entrapped erythrocytes with lectin in vitro and in vivo

Wheat germ agglutinin (WGA) agglutinated the L1210 leukemic cells and daunomycin entrapped erythrocytes in vitro. Comparing with control preparations, the greatest increase in survival was obtained in vivo when the daunomycin entrapped erythrocytes and WGA were given to BDF1 mice bearing L1210 cells.     

A lectin inNemopanthus mucronatus to papain treated porcine erythrocytes

Summary Extracts of the mountain holly,Nemopanthus mucronatus, contained an agglutinin to papain treated porcine erythrocytes but not untreated or neuraminidase treated cells. Human erythrocytes similarly treated did not react.     

Cyclic AMP level in red blood cells of Plasmodium berghei-infected Mastomys natalensis.

The present report describes the changes in cyclic AMP level which occur upon parasitization of red cells by Plasmodium berghei. Parasitized erythrocytes were separated from the non-parasitized population by percoll density-gradient centrifugation. An increase in the cyclic AMP content of both non-parasitized and parasitized erythrocytes of infected animals compared with that of uninfected animals was observed. The patterns of physiological response to isoproterenol in normal, parasitized and non-parasitized erythrocytes were identical.     

Agglutination of leukemic cells and daunomycin entrapped erythrocytes with lectin in vitro and in vivo

Summary Wheat germ agglutinin (WGA) agglutinated the L₁₂₁₀ leukemic cells and daunomycin entrapped erythrocytes in vitro. Comparing with control preparations, the greatest increase in survival was obtained in vivo when the daunomycin entrapped erythrocytes and WGA were given to BDF₁ mice bearing L₁₂₁₀ cells.     

Cyclic AMP level in red blood cells ofPlasmodium berghei-infectedMastomys natalensis

Summary The present report describes the changes in cyclic AMP level which occur upon parasitization of red cells byPlasmodium berghei. Parasitized erythrocytes were separated from the non-parasitized population by percoll density-gradient centrifugation. An increase in the cyclic AMP content of both non-parasitized and parasitized erythrocytes of infected animals compared with that of uninfected animals was observed. The patterns of physiological response to isoproterenol in normal, parasitized and non-parasitized erythrocytes were identical.     

Changes in erythrocyte membrane lipid composition affect the transient decrease in membrane order which accompanies insulin receptor down-regulation.

We have recently demonstrated, using electron paramagnetic resonance (EPR) spectroscopy, that insulin receptor internalization in response to insulin incubation (down-regulation) in human erythrocytes is accompanied by a transient decrease in membrane order, as measured by the 2T' parallel order parameter. Since membrane lipids play such an important role in receptor internalization, we investigated the possible effects that an alteration of the normally-occurring lipid profile might have on down-regulation and the concomitant transient decrease in membrane order. Consequently, human erythrocytes enriched with cholesterol and erythrocytes from cirrhotic patients were examined, because both of these groups of cells have a higher cholesterol/phospholipid molar ratio (CH/PL) than controls. The 5-nitroxystearate spin label, which inserts into the lipid bilayer of cell membranes, was used to monitor changes in 2T' parallel for a 3-h period at 37 degrees C. We report here that both cholesterol-enriched and cirrhotic erythrocytes do not down-regulate, as demonstrated by binding assays, and that they do not show the typical transient decrease in membrane order observed in controls. The results seem to indicate that a more ordered membrane inhibits internalization of the insulin receptor in erythrocytes, and that an increase in membrane disorder is necessary for insulin receptor down-regulation.     

刚地弓形虫培养上清抑制THP-1细胞增殖及诱导凋亡的研究

摘要：目的提取弓形虫体外细胞共培养上清,并研究上清对人急性单核细胞白血病细胞THP-1增殖及凋亡的影响。方法收集对数生长期的THP-1细胞以5X10^7／ml细胞浓度接种于不同培养瓶中,对照组加入含10％胎牛血清的RPMll640,实验组加入相同体积不同数量（2×10^7／ml、4X10^7／ml、8×10^7／m1）弓形虫速殖子培养上清,采用四甲基氮噻唑蓝（MTY）法检测吸光度（A490值）并计算THP-1细胞增殖抑制率;倒置显微镜下观察细胞形态变化;Annexin-V-FITC／PI染色细胞后上流式细胞仪检测各个时间点细胞凋亡率变化,以Western印迹方法分析凋亡相关蛋白Bax、Bcl-2的表达或活性。结果MTY法检测结果弓形虫培养上清呈时间剂量依赖性抑制THP-1细胞株增殖,倒置显微镜下观察处理组细胞有发泡现象和凋亡小体出现。流式细胞仪检测弓形虫感染后的THP-1细胞凋亡率较对照组有升高趋势（P〈0．05）,呈量效依赖性,Westernblot检测刚地弓形虫培养上清作用于THP-l细胞48h后实验组的Bax、Bcl-2蛋白表达较对照组的比值分别有明显的升高与降低（P〈0．05）。结论刚地弓形虫速殖子培养上清对体外培养THP-l细胞增殖有明显的抑制作用,并可诱导THP-1细胞凋亡。     

Ultrastrukturelle untersuchungen der juxtaepiphysären kapillaren nach perfusionsfixation

Summary Afger perfusion-fixation, the juxtaepiphyseal capillaries reveal endothelial cells with pores and without basement-membrane. Extravasates of erythrocytes are artefacts and are due to overexpanding of the endothelial cells in a loosened cartilage matrix.     

Selective inactivation of catalase during protoporphyrin induced photohemolysis of human red blood cells

Summary The level of some enzymatic activities in red blood cells before and after photohemolysis induced by protoporphyrin IX was studied. A 30% decrease in catalase activity was found both in normal erythrocytes and those from patients affected by favism. Other proteins though present in larger amounts inside the erythrocytes are not affected by the photohemolytic process.     

Selective inactivation of catalase during protoporphyrin induced photohemolysis of human red blood cells

The level of some enzymatic activities in red blood cells before and after photohemolysis induced by protoporphyrin IX was studied. A 30% decrease in catalase activity was found both in normal erythrocytes and those from patients affected by favism. Other proteins though present in larger amounts inside the erythrocytes are not affected by the photohemolytic process.     

Der erythrocytäre Magnesiumstoffwechsel bei intakter und kälteinhibierter Glykolyse

Summary Continuation of glycolysis in human erythrocytes by incubation of heparinized whole blood at 37°C is followed by a decrease in the Mg-content of red cells. On inhibition of glycolysis by cold (4°C), the Mg-content of erythrocytes remains unaltered or, often, slightly increases. These actions are in clear contrast to the behaviour of potassium ions under the same conditions.     

The generation of toxic activity from trypanosoma congolense.

Trypanosoma congolense organism, on incubation at 20 degrees C for 91/2h, were found to generate phospholipase like activity which was capable of mediating lysis of both nucleated cells and erythrocytes as well as acute inflammatory response on intradermal inoculation.     

I and i antigens of human erythrocytes : their detection by means of immunofluorescence technic and their changes during ontogenesis]

I and i antigens were detected by indirect immunofluorescence on human erythrocytes. 80% of the cord blood cells were brightly fluorescent with anti-i, 15% only with anti-I. In adult blood, this ratio is reversed, 2% only of the cells being intensively labelled with anti-i. The percentages characteristic of adult blood are established within the first 8 months of life.     

Permeability of fresh and stored human erthrocytes to glycerol and its acylated derivatives

The effect of copper ions on the permeation of glycerol and its mono-, di-, and triacetate derivatives was studied in fresh and stored erythrocytes. Permeability was unchanged with storage. Acylated glycerols permeate the cells mainly by non-facilitated mechanism, as their transport is almost unaffected by copper ions.     

Relationship between the pentose phosphate shunt and methemoglobin reductase activity in human erythrocytes: Effect of aging on methemoglobin reductase activity.

The increase in methemoglobin reductase activity in human erythrocytes upon incubation with inosine, phosphate, pyruvate occurs only in the presence of methylene blue. No difference in activity of the methemoglobin reductases was observed between enzyme extracts of fresh cells and aged cells.