神经节苷脂GM_1和GM_3对受体介导的转铁蛋白内吞过程的影响

我们从正常人脑及肝脏中分离得到纯化的神经节苷脂GM_1[Gal-GalNAc-(NeuNAc)Gal-Glc-Cer]和GM_3[NeuNAc-Gal-Glc-Cer],发现外源性GM_1或GM_3的加入能不同程度地抑制SMMC-7721人肝癌细胞的生长,但仅GM_3能抑制转铁蛋白(Tf)促进的细胞生长。进一步的研究发现,GM_3并不影响Tf与细胞膜表面受体的结合,而是抑制了受体介导的Tf内吞过程,内吞囊泡的形成及融合均受到影响。结果提示:GM_3在膜中的嵌入,可能使受体的构象发生变化或影响了膜的流动性,从而抑制Tf的内吞过程。     

Serum erythropoietin and its relation with soluble transferrin receptor in patients with different types of anaemia in a locally defined reference population

Serum erythropoietin (Epo) and soluble transferrin receptor (sTR) were measured in a locally defined reference population (n=100): healthy volunteers (n=50); iron‐ deficiency anaemia (n=41) and haemolytic anaemia (n=9) (β‐thalassaemia, n= 4; autoimmune, n=5). Our data demonstrated an inverse relationship between erythroid activity and Epo levels. The regression line between Ln Epo and haemoglobin (Hb) was highly significant: P < 0.0001, r²=0.8275, Ln Epo=8.5346–0.04275 Hb, confidence limit 95%. The mean observed/predicted (O/P) ratio of Ln (Epo) was 1.01 ± 0.11. We demonstrated that the serum Epo concentration in this particular population correlated consistently with clinical measures of erythropoietic activity. sTR, a new index of erythropoiesis, varied from 16.1 to 148 nmol/l, mean 62.0 nmol/l in the anaemic patients’ group. The relationship between Ln Epo and Ln sTR was highly significant: P < 0.0001. We conclude that locally defined regression analyses are crucial for correct data interpretation and can indicate whether or not Epo production is appropiate or inappropiate. Serial determinations of sTR could help in the assessment of response to therapeutic doses of Epo.     

Evaluation of a bench-top nephelometric immunoassay analyzer

We evaluated the Technicon DPA-1 immunoassay analyzer on its analytical characteristics. Therefore we studied three assays: albumin in cerebrospinal fluid and IgG and transferrin in serum. When tested with the Cusum test for linearity albumin, IgG, and transferrin measurements showed no deviation from linearity. Closer examination revealed an abrupt difference of recovery (from 99 to 87%) in the albumin assay when the automatic dilution changed over from the primary analytical to the high analytical concentration range. One calibration was found sufficient for at least 14 days of measurement. Imprecision was well below the critical limits for reproducibility. We found reasonable agreement between the results from the DPA-1 and the results from comparison methods. However, the correlation plot of IgG showed lack of fit at a distinct segment of the regression line. This appeared to be caused by the poor recovery of the DPA-1 at the lower limit of the high analytical concentration range. The assays of IgG and transferrin were found insensitive for interference by hemoglobin, triglycerides, urea, and bilirubin. The albumin assay was found sensitive for bilirubin and triglycerides. No reagent- and sample-to-sample carry-over could be detected in the assays evaluated.     

间接免疫酶标法检测白血病细胞表面的运铁蛋白受体

用间接免疫酶标法检测急性单核细胞性白血病(急单)、急性粒细胞性白血病(急粒)、急性淋巴细胞性白血病(急淋)、慢性粒细胞性白血病(慢粒)、慢性淋巴细胞性白血病(慢淋)患者外周血细胞表面的运铁蛋白受体(TR)。47例患者中43例阳性,4例阴性;而48例正常血象者及非白血病患者外周血细胞的TR均为阴性。表明白血病细胞表面TR增加。用此法检测2例白血病及5例正常骨髓片TR阳性细胞的百分率与形态检查幼稚细胞总数的百分率基本相符,而1例急性巨核细胞性白血病及1例急淋骨髓片TR阳性细胞百分率明显高于幼稚细胞,提示白血病细胞TR表达可能较早于形态变异。     

Are the serum levels of endotoxin-binding proteins reliable predictors of complications in the course of peritonitis?

Abstract. In the present study, the serum levels of the endotoxin-binding proteins transferrin, α₂-macroglo-bulin and Gc-globulin were nephelometrically determined in the morning of the first day after surgical treatment of peritonitis. The aim was to determine whether the occurrence of organ failure can be predicted by the serum levels of the described proteins. A serum level of transferrin below 1.15 g 1^-1 allows the prediction of organ failure with a sensitivity of 78.6% and a specificity of 81.8%. As in the case of α₂-macroglobulin, sensitivity and specificity reached 67.8% and 72.7% respectively at a border level of 1.05 g 1^-1. The predictive value of Gc-globulin, limit 0.2 g 1^-1, was in the same range. So the serum levels of these proteins allow an early prediction of forthcoming organ failure in the course of peritonitis. Furthermore, these results support the significance of the endotoxin interaction with these proteins.     

肿瘤坏死因子α和干扰素γ对癌性贫血患者红细胞生成素生成和红系增生的影响

目的探讨癌性贫血患者EPO生成及红系增生的变化，以及TNF、IFN等负调控细胞因子对EPO生成及红系增生的影响。方法对50例癌性贫血患者、15例癌症无贫血患者及对照组采用放射免疫法检测血清EPO水平，ELISA方法检测血清可溶性转铁蛋白受体（sTfR）、TNF-α、IFN-γ水平，用直线回归方法及相关分析定量分析体内EPO生成、红系增生情况及其与TNF-α、IFN-γ的关系。结果癌性贫血患者血清EPO水平为（23．11±10．00）IU／L，明显低于同等程度贫血的缺铁性贫血患者的（43．00±22．00）IU／L（P〈0．01）；实测值／预估值（O／P）EPO为0．88（0．54～1．10），明显低于对照组及癌症无贫血患者，后二者之间的O／PEPO差异无统计学意义。癌性贫血患者的血清sTfR水平（30．8±16．95）nmol／L，高于健康对照组的（17．82±6．76）nmol／L，而低于溶血性贫血患者的（65．75±29．12）nmol／L，差异均有统计学意义（P〈0．05）；O／PsTfR为0．89（0．57～1．22），明显低于对照组及癌症无贫血患者，后二者之间O／PsTfR差异无统计学意义。正常情况下存在于log（EPO）与血红蛋白浓度之间以及log（sTfR）与血红蛋白浓度之间的反比关系消失。癌性贫血患者血清TNF-α、IFN-γ水平分别为（25．75±26．71）ng／L、（50．49±42．12）ng／L，均显著高于正常对照组及癌症无贫血组。TNF-α、IFN-γ水平与血红蛋白浓度之间呈负相关关系。TNF-α与O／PEPO、O／PsTfR之间呈负相关。血清IFN-γ水平与O／PEPO之间无相关关系，与O／PsTfR呈负相关。结论TNF-α、IFN-γ等负调控因子的作用下，内源性EPO对贫血的反馈性增生相对不足，以及骨髓红系对EPO的反应性增生相对不足参与癌性贫血的发病机制。     

黎族地中海贫血患者血清促红细胞生成素和转铁蛋白受体水平的研究

为研究地中海贫血患者与血清可溶性转铁蛋白受体(sTfR)和红细胞生成素(EPO)的关系，并估计地中海贫血骨髓红系增生程度，应用酶联免疫法检测50例地中海贫血患者和50例正常人对照的sTfR和EPO水平：结果显示，β—重型地中海贫血患者血清EPO和sTfR水平均明显高于正常对照组(P＜0.05)，而轻型患者与正常人无显著差别。结论：黎族地中海贫血患者血清中EPo和sTfR水平升高与地中海贫血的类型有关。     

缺糖基转铁蛋白对酒精性肝病的诊断

目的 检测酒精性肝病(ALD)患者血清中的缺糖基转铁蛋白(CDT)与总TI的比值％CDT,并与GGT、MCV、ALT、AST等指标比较,评价其对ALD的诊断价值。方法 选择健康不饮酒对照组、非酒精性肝病的其他肝病组(NALD组)、ALD组(3组均为男性),分别检测％CDT、GGT、MCV、ALT、AST等指标,各指标在不同组间的比较用F检验;各项目之间的关系研究用直线相关,计算相关系数;同时绘制各指标的ROC曲线。结果 ALD组中的％CDT显著高于对照组、NAID组。％CDT诊断ALD的ROC曲线下面积为0．857,敏感度0．75,特异度0．88,而GGT这三者分别为0．751、0．75、0．76,MCV分别为0．669、0．30、0．78,ALT分别为0．512、0．25、0．72,AST分别为0．426、0．25、0．68。％CDT、与GGT不相关,但两者联合检测敏感度提高到90％。结论 对于ALD的诊断,％CDT、GGT、MCV均具有一定的诊断价值,尤其％CDT是一个很好的辅助诊断指标。％CDT与GGT联用可提高敏感度。     

不同贫血患儿血清可溶性转铁蛋白受体变化及其临床意义

用单克隆及多克隆双抗体夹心ＥＬＩＳＡ法测定１５例正常小儿及４６例不同贫血患儿血清可溶性转铁蛋白受体（ｓＴｆＲ），发现不同贫血患儿ｓＴｆＲ水平与对照（４．５４±１．０８ｍｇ／Ｌ）相比有显著性差异，溶血性贫血组（９．９４±３．３２ｍｇ／Ｌ）与缺铁性贫血组（１３．９２±４．４５ｍｇ／Ｌ）显著升高；再生障碍性贫血（再障）组（２．０６±０．８２ｍｇ／Ｌ）显著降低，纯红再障最低，重型再障显著低于慢性再障值。ｓＴｆＲ水平可由机体含铁状况和红系生成率共同决定，在诊断缺铁及再障的病情预后估计方面有一定临床价值。