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1.
The prolytic loss of K., i.e. the loss of K which takes place from red cells exposed to hypolytic concentrations of lysins, has been measured in systems containing distearyl lecithin, sodium taurocholate, sodium tetradecyl sulfate, saponin, and digitonin, by means of the flame photometer. The lysins are added in various concentrations to washed red cells from heparinized human blood, and the K in the supernatant fluids is determined after various intervals of time and at various temperatures. The prolytic loss Kp is compared in every experiment with the loss Ks into standard systems containing isotonic NaCl alone, with no lysin. The losses Ks and Kp increase with time, so that new steady states are approached logarithmically. The values of Kp which correspond to the new steady states depend on the lysin used, being greatest with taurocholate and smallest with digitonin. The temperature coefficient of the loss is positive, and the extent and course of the losses have no apparent relation to the prolytic shape changes. In systems in which the loss of K is appreciable, it can be inhibited by the addition of plasma or of either cholesterol or serum albumin. Of these two substances, even when used in quantities which have an approximately equal effect in inhibiting hemolysis, serum albumin is much the more effective. Just as the prolytic loss of K occurs without the loss of any Hb, so in concentrations of lysin sufficient to produce hemolysis the loss of K, expressed as a percentage of the total red cell K, increases much more rapidly with lysin concentration than does the loss of Hb expressed as a percentage of the total Hb. The explanation of these relations depends on whether the loss of K is treated as being all-or-none in the case of the individual cell or as being the result of the loss of part of the K from all of the cells. This point has still to be decided.  相似文献   

2.
3.
When the washed red cells of heparinized human blood are exposed at 4°C. to methanol, ethanol, guaiacol, or resorcinol in hypolytic concentrations in isotonic NaCl, the prolytic loss of K at the end of 20 hours varies from about 25 per cent of the initial K content of the cells in the case of 3.1 M methanol to about 55 per cent of the initial K in the case of 0.04 M resorcinol. As in the case of the prolytic losses observed with other lysins, the K loss is rapid at first and then slows down so that what appears to be a new steady state is reached logarithmically. The K lost from the cells during the period of the prolytic loss is replaced by an approximately equivalent amount of Na, derived from the isotonic NaCl in which the cells are suspended. The Na which enters can be replaced by K by washing the cells in isotonic KCl, and this K can again be replaced by Na by washing the cells in isotonic NaCl. The remainder of the cell K., i.e. the K which was not lost during the period of the prolytic loss, is retained in the cell unaffected by these washing procedures. The capacity of red cells for undergoing disk-sphere transformations is scarcely affected by their having been exposed to hypolytic concentrations of methanol, ethanol, guaiacol, or resorcinol in isotonic NaCl, and their resistance to osmotic hemolysis and to lysis by saponin and digitonin is altered only in minor respects even when as much as 50 per cent of the cell K has been exchanged for Na. Some restriction to the movement of K between the cell and its environment is apparently modified irreversibly when the cell is exposed to hypolytic concentrations of lysins, and the modification is such that only a fraction of the cell K is affected, the fraction being a function of the lysin concentration, the duration of its action, and other factors. A modification of some part of the cell structure and of the properties dependent on its integrity is probably involved: K may be lost more readily from some cells than from others, from some parts of the cell more readily than from other parts, or the explanation may lie in changes in the extent to which Hb binds ions or in modifications of metabolic processes.  相似文献   

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5.
1. Unsensitized sheep cells suspended in sugar solutions are agglutinated by electrolytes whenever the potential is depressed to 6 millivolts or less, except in the case of MgCl2 or CaCl2. 2. With these salts no agglutination occurs although there is practically no potential. The presence of these salts prevents acid agglutination. This is presumably due to a decrease in the "cohesion" between the cells. 3. Cells which have been sensitized with specific antibody, ricin, colloidal stannic hydroxide, or paraffin oil, are agglutinated whenever the potential is decreased below about 12 millivolts. 4. The agglutination by electrolytes is therefore primarily due to a decrease in the potential whereas agglutination by immune serum, ricin, etc., is due primarily to an increase in the critical potential.  相似文献   

6.
人外周血中LAK细胞的克隆化   总被引:5,自引:0,他引:5  
本文报道首次采用半固体-液体两步法克隆正常人外周血单个核细胞(PBMNC)中的淋巴因子激活的杀伤细胞(LAK)获得成功。先用含重组人白细胞介素2(rhIL-2)的软琼脂半固体克隆外周血中的T细胞,再将T细胞克隆转移至96孔板中继续在含rhIL-2的液体中培养。~(51)Cr释放的结果表明,约10~30%的克隆对NK敏感的K562细胞和NK不敏感的H7402、Anip-1肿瘤细胞均有细胞毒性,即为LAK细胞克隆。LAK细胞克隆能在体外含rhIL-2培养液中增殖1.5~3.0个月,每个克隆可扩增至10~9~10~(10)个细胞,仍然维持LAK细胞活性。表型分析的结果表明,克隆的LAK细胞CD3( )、CD8( ),属T细胞系统。有增殖能力的LAK前体细胞在PBMNC中的频率约为1~3×10~(-4)。用有限稀释法将LAK细胞克隆进一步亚克隆,98%以上的亚克隆均有LAK活性,表型也和原克隆相同,证实原克隆具有克隆源性。本文的两步法克隆LAK细胞程序可在较短时间内获得大量均一的LAK细胞,极大地有助于LAK细胞的深入研究和广泛应用。  相似文献   

7.
8.
1. The electrophoretic mobility of unhemolyzed human red cells has been determined as a function of ionic strength at approximately constant pH in isotonic mixtures of glucose solution and saline-phosphate buffer solution. 2. Above an ionic strength of about 0.02 the cells behave as particles with a smooth surface of large radius of curvature. Below an ionic strength of about 0.02, changes of the surface occur, probably involving a decrease of charge density and perhaps connected with injury of the surface. 3. The mobility as a function of pH at an ionic strength of 0.172 has been determined for human red cells, for the lipid extract of the cells, and for the stroma protein of the cells. The isoelectric points of cells, lipid, and protein have been found to be about 1.7, 2.6, and 4.7 respectively. 4. The pH-mobility data lead to the conclusion that a red cell surface is composed largely of lipid and dominated by strong acid groups, possibly the phosphoric acid groups of cephalin molecules.  相似文献   

9.
10.
The anomalously small swelling which the red cells of human oxalated blood undergo in hypotonic plasma is related to the extent to which the cells are crenated. Reasons are given for regarding crenation as corresponding to gelation, and the bulk modulus for crenated cells, calculated from the measurements of swelling in hypotonic plasma, is shown to be of the same order as that for gelatin gels.  相似文献   

11.
1. No significant change with time (to 24 hours) in the cataphoretic velocity of certain mammalian red cells occurs when the cells are suspended in M/15 phosphate buffer at pH = 7.35. Neither successive washings nor standing effect a change. 2. In M/15 phosphate buffer at pH 7.35 ± 0.03 the following order of red cell velocity has been obtained. The numbers in parenthesis are µ per second per volt per centimeter. See PDF for Structure The order, though not the absolute values, was the same in buffered isotonic dextrose. Human and rabbit cells showed similar differences when both were studied simultaneously in the serum of either. Under these conditions, there is no apparent relationship between zoological Order and cataphoretic velocity. 3. Cholesterol and quartz adsorb gelatin from dilute solution in the phosphate buffer. Red cells, on the other hand, even after 24 hours contact with gelatin solution, retain their previous velocity. 4. Pregnant and non-pregnant white female humans have the same red cell cataphoretic velocity. (The cells were not agglutinated.) 5. In a series of severe anemias no significant change in cataphoretic velocity was in general apparent, although marked changes in the morphology of the red cells were present.  相似文献   

12.
In Vol. 19, No. 4, March 20, 1936, page 603, in the eleventh line from the bottom of the page for "zj = 2, zjj = 1", read "zj = 1, zjj = 2". On the same page in the fourteenth line from the bottom of the page for "jj(HPO4-)" read "jj(HPO4--)".  相似文献   

13.
14.
By using chromosome markers in two separate cell lines of a human dispermic chimera, it was shown that 4.9% of metaphases in suspensions of PHA-cultured lymphocytes were paired because of non-random factors. A similar amount of metaphase pairing occurred in cultured lymphocytes of normal donors, and evidence from the relative mitotic cycles of the paired cells indicated that some of this pairing was non-random. Such non-random pairing could be a source of bias in cell kinetic and other studies involving metaphase cells in lymphocyte cultures.  相似文献   

15.
1. The addition of blood serum displaces the optimum for agglutination of red blood cells in a salt-free medium to the reaction characteristic of flocculation of the serum euglobulin. 2. This effect is not due merely to a mechanical entanglement of the cells by the precipitating euglobulin, since at reactions at which the latter is soluble it protects the cells from the agglutination which occurs in its absence. 3. A combination of some sort appears therefore to take place between sheep cells and sheep, rabbit, and guinea pig serum euglobulin, and involves a condensation of the serum protein upon the surface of the red cell. 4. At the optimal point for agglutination of persensitized cells both mid- and end-piece of complement combine with the cells. 5. Agglutination is closely related to an optimal H ion concentration in the suspending fluid, and probably of the cell membrane, and not to a definite reaction in the interior of the cell.  相似文献   

16.
急进高原人群血浆NO和红细胞SOD变化   总被引:2,自引:0,他引:2  
目的:本文旨在探讨急进高原低氧人群血浆NO和红细胞SOD的变化及其相互作用的生理意义。方法:以急进高原的健康人群为研究对象,年龄范围在18~21岁之间,分为对照组和高原低氧组。血浆NO测定采用硝酸还原酶法,红细胞SOD测定采用亚硝酸盐显色法。结果:高原低氧组血浆NO浓度显著低于平原对照组;高原低氧组红细胞SOD含量显著高于平原对照组。结论:急进高原低氧人群红细胞SOD显著升高,NO降低,可能与低氧造成肺血管收缩有关系。但NO、自由基及自由基清除剂(SOD)之间的调控网络,在低氧的病理生理过程中的作用有待进一步研究  相似文献   

17.
人CD34~ 造血细胞是具有高度自我更新、多向分化及重建长期造血与免疫学功能的独特体细胞。为系统探索CD34~ 造血细胞的形态、细胞化学及超微结构特征,新近我们设计组合并建立了CIMS-100-FACS 440无菌二次分选术,可使所获CD34~ 造血细胞的纯度达100%。在此基础上,本研究采用Cambri-dge Quantimet 970全自动图像分析仪对光学显微镜、扫描电镜及透射电镜下的CD34~ 造血细胞进行了体视学方面的某些探讨,进一步从三维结构信息中深刻揭示CD34~ 造血细胞的形态计量学特征。经扫描→模数转换←阴影校正→图像暂存←统计分析等检测,结果表明:CD34~ 造血细胞的直径3.490—6.741μm,周长11.776—26.240μm,面积9.565—35.686μm~2,形状因子1.048—1.840,核浆比0.58—0.72,平均光密度0.17675—0.65100,积分光密度2717.217—9870.643。由此可见CD34~ 造血细胞的确为非均一细胞群,这可能与CD34~ 造血细胞的功能亚群与分化阶段密切相关。据我们所知,这是国际上首次有关人CD34~ 造血细胞体视学特征的报道。  相似文献   

18.
A theoretical treatment is given of the rate of escape of hemoglobin from the hemolyzed red corpuscle. For complete permeability of the surface, as may perhaps be produced by strong lysins, the time taken for the hemoglobin to decrease to 10 per cent of its original concentration is calculated to be 0.16 seconds (for the human cell). For dilute saponin, giving complete lysis of human cells in 3 minutes, Ponder found a time of escape of 4 seconds, from which the permeability of the membrane to the pigment is calculated to be µH = 5 x 10–5 cm./sec.  相似文献   

19.
目的探讨肥大细胞与肠嗜铬细胞在人胃溃疡发病中的作用。方法收集胃溃疡标本90例,正常胃组织30例。采用甲苯胺兰检测肥大细胞的数量、分布,免疫组化染色检测类胰蛋白酶、5-羟色胺表达,另取5例新鲜胃溃疡组织进行电镜检测。结果溃疡组与对照组比较肥大细胞及肠嗜铬细胞数量均明显增加(P〈0.05),肥大细胞在溃疡组脱颗粒现象明显,线性相关分析显示肥大细胞与肠嗜铬细胞数量呈正相关,相关系数为0.741。结论肥大细胞与肠嗜铬细胞在人胃溃疡发病中均发挥了作用。  相似文献   

20.
It has been shown, within the probable limit of error of the methods of measurement employed, that the Donnan equilibrium determines the distribution of H and Cl ions between the cell and the surrounding fluid. This equilibrium is a consequence of the impermeability of the cell membrane to the inorganic cations of the cell. The mechanism responsible for this equilibrium is suggested as that concerned in the secretion of HCl by the cells of the gastric mucosa. If the salt concentration of the medium is low there may result from the Donnan equilibrium a thermodynamic P.D. of considerable magnitude. In the presence of low concentrations of electrolytes, this P.D. is to be regarded as positive in sign at reactions of the medium at which the cataphoretic charge of the cell is negative in sign. The explanation of this discrepancy in sign of charge may lie in the existence at an outer phase-boundary of a second Donnan equilibrium the nature of which is determined by the ionization of the protein of the cell membrane.  相似文献   

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