垂直板等电聚焦法测定基因重组人红细胞生成素(rhEPO)各异构体组分含量

建立了测定基因重组人红细胞生成素(rhEPO)各异构体组分含量的垂直板等电聚焦方法,该方法经济,测定结果准确、可靠,与《欧洲药典》6.0版规定的毛细管区带电泳法的测定结果基本一致,本法为rhEPO生产过程控制及原液质量控制提供了准确、可行的检测手段。     

重组人红细胞生成素体内生物活性检测

建立了测定重组人红细胞生成素（rhEPO）体内生物活性的多血小鼠法。实验表明:rhE-PO在0.05～0.8 iu/鼠剂量范围内.对数剂量与反应（~(59)Fe 摄入量）呈直线关系。经多批rhEPO产品的体内生物活性测定,证明该法结果准确,重现性好.     

毛细管区带电泳分离重组人红细胞生成素方法的改进

目的:针对欧洲药典收载的rhEPO毛细管电泳检测方法中pH限制严格,可操作性差的缺点,进行缓冲液组成的优化。方法:实验将响应面分析法(RSM)用于毛细管区带电泳,用最少的实验次数确定了对分离影响最大的因素,并由此确定了最佳缓冲液组成及pH范围。结果:在此优化条件下rhEPO的8个不同糖基化形式在40min内得到了基线分离,各相邻峰间的分离度达1.63～3.29,柱效达1.63×10~5～3.23×10~5理论塔板数·m~(-1),峰形良好。结论:方法具有较宽泛的pH范围,比欧洲药典更为实用。     

重组人红细胞生成素体内外活性检测方法的比较

目的对重组人红细胞生成素 (rhEPO)体内外活性测定结果进行比较 ,说明体内外活性测定对rhEPO质量控制的意义。方法采用59Fe摄入法、网织红细胞法和ELISA法测定rhEPO制品的体内外生物学活性。结果59Fe摄入法和网织红细胞法测定结果一致 ,与rhEPO唾液酸含量具有相关性。当rhEPO唾液酸含量较低时 ,ELISA法与体内活性测定结果有较大差异。结论rhEPO体内外活性测定方法可以相互补充 ,均是保证rhEPO质量不可缺少的质控手段。     

重组人促红细胞生成素的临床应用

促红细胞生成素(EPO)是由肾脏分泌的一种活性糖蛋白,能刺激骨髓红系造血母细胞的增殖和分化。临床研究显示,EPO除可用于慢性肾性贫血治疗外,对多种疾病如获得性免疫缺陷综合征、肿瘤、充血性心力衰竭、危重疾病以及丙型肝炎病毒感染等疾病所致贫血亦有较好的疗效。本文就该药的作用机制、临床研究、不良反应及注意事项进行简要阐述。     

国外重组人红细胞生成素产品的体内外生物学活性测定

目的 :用WHO提供的红细胞生成素 (EPO)生物学活性国际标准品 ,测定国外重组人红细胞生成素(rhEPO)产品的体内外生物学活性 ,并比较其差异 ,探讨作为工作标准品的可能性。方法 :网织红法测定rhEPO体内生物学活性 ,ELISA法测定体外生物学活性。结果 :生血素、利血宝的体内生物学活性分别为 1880、2 986IU/瓶 ,体外生物学活性分别为 1867、2 880IU/瓶。结论 :国外rhEPO产品体内、体外生物学活性较一致 ,但与标示量有一定差距 ,需经标定后才能作为EPO产品的体内生物学活性标准。     

重组人红细胞生成素治疗肾性贫血

慢性肾功能衰竭(CRF)患者导致的贫血是临床常见的表现,主要由于慢性肾功能衰竭患者肾小管功能受损,导致促红细胞生成素生成减少是引起贫血的直接原因。贫血不能纠正而导致肾功能进行性恶化的理论已得到肾病学家的一致认可[1]。因此,应用何种办法纠正患者的贫血目前得到广泛的重     

Recombinant human erythropoietin reduces plasminogen activator inhibitor and ameliorates pro-inflammatory responses following trauma

Background and the purpose of the study

sBesides its hematopoietic effects, erythropoietin (EPO) by mobilization of iron and modulation of some inflammatory cytokines has antioxidant and anti-inflammatory properties. The purpose of this study was to evaluate these effects of erythropoietin and its impact on organ function in traumatized patients.

Methods

Twenty-six ICU-admitted traumatized patients within 24 hrs after trauma were randomly assigned to the EPO (received EPO, 300 units/Kg/day) and Control (not received EPO) groups. The inflammatory biomarkers including Tumor Necrosis Factor alpha (TNF-α), Interleukin 1 (IL-1), Plasminogen Activator Inhibitor 1 (PAI-1) and Nitrotyrosine were recorded at the admission, 3, 6 and 9 days thereafter. Acute Physiology and Chronic Health Evaluation (APACHE II) and Sequential Organ Failure Assessment (SOFA) scores were also recorded.

Results

Among 12 patients (EPO group) TNF-α level at the day of 9 (P=0.046), and within EPO group at the days of 3 (P=0.026 ameliorate), 6 (P=0.016), and 9 (P=0.052) were significantly lowered. Level of IL-1 and PAI-1 decreased significantly at days of 3, 6 and 9 post intervention. Also there were significant differences between two groups in the SOFA score during three measured time intervals (the first, third and seventh days).

Conclusion

From the results of this study it seems that injection of erythrocyte stimulating agent is well tolerated and inhibits the inflammatory response and oxidative stress following trauma.     

Human serum albumin interaction with oxaliplatin studied by capillary isoelectric focusing with the whole column imaging detection and spectroscopic method

Capillary isoelectric focusing (CIEF) with whole column imaging detection (WCID) was used to investigate drug-protein interactions. This study was designed to examine the interaction between the platinum-based anticancer drug, oxaliplatin, with human serum albumin (HSA) in aqueous solution at physiological pH with drug concentrations of 10 to 100 μM and a constant concentration of HSA (5.0 × 10⁻⁵ M). The reaction mixtures were incubated for 0, 0.5, 1, 12, 24, 48 and 72 h at 37 °C in a water bath. The CIEF results indicate that with increasing the drug concentration, the complex formation of protein adducts increased compared to low-drug concentrations and major structural changes were observed as the incubation time progressed. The altered CIEF profile demonstrated the possible conformation change due to the binding of the drug. Results also showed a significant protein's pI shift for higher HSA–oxaliplatin incubation ratios. Furthermore, spectroscopic evidence shows that oxaliplatin caused the fluorescence quenching of HSA by formation of HSA–oxaliplatin complex. Using the Stern–Volmer equation, the quenching constants were calculated in the linear range. The quenching rate constants K_q at three different temperatures indicating the presence of static quenching mechanism in the interactions of oxaliplatin with HSA. This paper describes the validity of the CIEF-WCID technique for the study of protein–drug interactions and provides useful information and insight into the interaction of anticancer drugs with HSA.     

Antibody-based enzyme-linked lectin assay (ABELLA) for the sialylated recombinant human erythropoietin present in culture supernatant

The terminal sialic acid of human erythropoietin (hEPO) is essential for in vivo activity. The current resorcinol and HPLC methods for analyzing alpha2,3-linked sialic acid require more than a microgram of purified rhEPO, and purification takes a great deal of time and labor. In this study, we assessed the use of an antibody-based enzyme-linked lectin assay (ABELLA) for analyzing non-purified recombinant hEPO (rhEPO). The major problem of this method was the high background due to terminal sialylation of components of the assay (antibody and bovine serum albumin) other than rhEPO. To solve this problem, we used a monoclonal antibody (Mab 287) to capture the rhEPO, and oxidized the bovine serum albumin used for blocking with meta-periodate. The sialic acid content of non-purified rhEPO measured by ABELLA was similar to that obtained by the resorcinol method on purified rhEPO. ABELLA has advantages such as adaptability and need for minimal amounts of rhEPO (40 ng/ml). Our observations suggest that ABELLA should reduce the time and labor needed to improve culture conditions so as to increase protein sialylation, and also facilitate the study of sialylation mechanisms.     

Mycobacterium tuberculosis chaperonin 10 and N-truncated fragments Their synthesis and purification by the isoelectric focusing technique carried out in solution

The Mycobacterium tuberculosis chaperonin 10 protein and fragments corresponding to sequences 59-99, 51-99 and 26-99 were synthesised by the solid-phase methodology using a double coupling protocol and without the aid of capping agents. After the final acid cleavage using the low TFMSA-high HF protocol the polypeptides were purified by either the ion exchange chromatography/RP-HPLC combination or the isoelectric separation carried out in solution and followed by semi-preparative RP-HPLC. Comparison of the results obtained through the two approaches indicated that in general the isoeletricfocusing/HPLC combination was superior both in terms of recovery of final material and its purity. The advantages found were as follows: (i) Unlike ion exchange chromatography, no tailoring of the separation conditions is required. (ii) Several consecutive focusings can be carried out in progressively narrower pH gradients. This increases the separation resolution without the need of changing other separation parameters, (iii) Very little manipulation is needed, and each focusing requires 3-5 h. (iv) Full compatibility with non-ionic denaturants such as 8 M urea. This increases solubility so that using the ROTOFOR instrument described here 50-100 mg crude polypeptide can be processed daily. Thus the isoelectric focusing technique carried out in solution is a valid and inexpensive alternative to ion exchange chromatography. © Munksgaard 1997.     

Sensitivity and specificity of detection methods for erythropoietin doping in cyclists

Recombinant human erythropoietin (rHuEPO) is used as doping a substance. Anti‐doping efforts include urine and blood testing and monitoring the athlete biological passport (ABP). As data on the performance of these methods are incomplete, this study aimed to evaluate the performance of two common urine assays and the ABP. In a randomized, double‐blinded, placebo‐controlled trial, 48 trained cyclists received a mean dose of 6000 IU rHuEPO (epoetin β) or placebo by weekly injection for eight weeks. Seven timed urine and blood samples were collected per subject. Urine samples were analyzed by sarcosyl‐PAGE and isoelectric focusing methods in the accredited DoCoLab in Ghent. A selection of samples, including any with false presumptive findings, underwent a second sarcosyl‐PAGE confirmation analysis. Hematological parameters were used to construct a module similar to the ABP and analyzed by two evaluators from an Athlete Passport Management Unit. Sensitivity of the sarcosyl‐PAGE and isoelectric focusing assays for the detection of erythropoietin abuse were 63.8% and 58.6%, respectively, with a false presumptive finding rate of 4.3% and 6%. None of the false presumptive findings tested positive in the confirmation analysis. Sensitivity was highest between 2 and 6 days after dosing, and dropped rapidly outside this window. Sensitivity of the ABP was 91.3%. Specificity of the urine assays was high; however, the detection window of rHuEPO was narrow, leading to questionable sensitivity. The ABP, integrating longitudinal data, is more sensitive, but there are still subjects that evade detection. Combining these methods might improve performance, but will not resolve all observed shortcomings.     

重组人类促红细胞生成素防治早产儿贫血的临床研究

目的　应用不同剂量国产重组人类促红细胞生成素 (rhu EPO)防治早产儿贫血 ,探讨其最适剂量和疗效。方法　 83例孕周 <36周 ,出生体重 <2 5 0 0克早产儿 ,以入院顺序按rhu EPO剂量随机分为第 1组 2 5例 (rhu EPO 75 0IU·kg-1·w-1) ,第 2组 18例 (45 0IU·kg-1·w-1) ,第 3组 2 0例(30 0IU·kg-1·w-1) ,分为每周 3次 ,静脉注射 ,疗程 4周。另设第 4组 2 0例为对照组。结果　 4组早产儿生后血红蛋白 (Hb)、红细胞压积 (Hct)渐行下降。第 1组下降最轻 ,第 2组次之 ,对照组最明显 ,经方差分析有显著性差异 (P <0 0 1) ;网织红细胞 (Ret)明显增高 ,且Ret升高程度和rhu EPO剂量有关 ;治疗后血清EPO浓度以第 1组最高 ,对照组最低 ,有显著性差异 (P <0 0 1) ,但第 3组与对照组比较无显著性差异 (P >0 0 5 ) ;血清铁 (Fe)生后均逐渐下降 ,治疗各组略低于对照组 ,无显著性差异。结论　早期rhu EPO治疗可提高Hb、Hct、Ret,并且疗效和剂量有关 ,体内充足的铁储备是确保rhu EPO疗效的重要因素。     

Target-mediated pharmacokinetic and pharmacodynamic model of recombinant human erythropoietin (rHuEPO)

A mechanism-based pharmacokinetic–pharmacodynamic (PK/PD) model was developed for recombinant human erythropoietin (rHuEPO) to account for receptor-mediated endocytosis via erythropoietin receptor (EPOR) as a primary mechanism for nonlinear disposition of rHuEPO as well as activation of erythropoietic stimulation. Time profiles of rHuEPO concentrations following a wide range of intravenous (i.v.) doses in rats (10, 100, 450, 1,350, 4,050 IU/kg), monkeys (500, 2,000, 4,000 IU/kg), and man (10, 100, 150, 300, 500 IU/kg) were examined. The mean data of reticulocytes, red blood cells (RBC), and hemoglobin for five different doses in rats were analyzed. The PK model components included receptor binding, subsequent internalization and degradation, EPOR turnover, non-specific tissue distribution, and linear first-order elimination from plasma. The equilibrium dissociation constant (K _D ) was similar between rats and monkeys (0.11 nM) and was 10-fold lower in humans (0.012 nM). The PD effects of rHuEPO were described by an indirect response model with lifespan cell loss and driven by the rHuEPO–EPOR complex. A generalized nonlinear PK model for rHuEPO taking into account EPOR binding of the drug in bone marrow was proposed and well described the PK profiles of rHuEPO following i.v. doses in rats, monkeys, and man. The present receptor-mediated PK/PD model for rHuEPO closely reflects underlying mechanisms of disposition and dynamics of rHuEPO.     

人尿红细胞生成素和血栓调节素的纯化研究

目的从人尿中分离纯化红细胞生成素 (EPO)和血栓调节素 (TM )。方法用超滤浓缩、离子交换层析及亲和层析等方法从新鲜人尿中分别纯化EPO和TM。结果从 2 0 0 0kg新鲜人尿中分别纯化得到了 4.47mgEPO和 9.92mgTM ,得率分别为 31.9%和 2 5 .0 % ,分子量分别为 (38.6± 1.0 )kD和 (6 0± 1.4)kD ;等电点分别为3.6 0± 0 .0 2和 3 .70± 0 .0 2 ;TM富含Glu、Ala和Gly ,毛细管区带电泳分析高度均一 ,有关生化参数与文献报道基本一致。结论该工艺可获得纯度较高的EPO和TM。     

The pharmacokinetics of erythropoietin in the cerebrospinal fluid after intravenous administration of recombinant human erythropoietin

Objectives Erythropoietin (EPO) was originally described as a regulator of erythropoiesis. Recently, synthesis of EPO and expression of the EPO receptor (EPO-R) have been reported for the central nervous system (CNS). The potential use of EPO to prevent or reduce CNS injury and the paucity of information regarding its entry into the human CNS led us to examine the pharmacokinetics (PK) of recombinant human EPO (r-HuEPO) in the serum and cerebrospinal fluid (CSF).Methods Four patients with Ommaya reservoirs were enrolled to facilitate serial CSF sampling. R-HuEPO was given intravenously (IV) in single doses of 40,000 IU or 1,500 IU/kg and in multiple doses of 40,000 IU daily for 3 days.Results The EPO concentrations in the CSF increased after a period of slow equilibration. Linear first-order distribution kinetics were observed for serum and CSF. The concentration of EPO in the CSF was proportional to the serum concentration of EPO and the permeability of the blood-brain barrier (BBB), as determined by the albumin quotient (Q_A=[albumin] CSF/[albumin] serum). A rise in the CSF concentration was seen as early as 3 h after IV administration. Peak levels (C_max) were reached between 9 h and 24 h. After a single dose of 1,500 IU/kg, the C_max in the CSF ranged from 11 mIU/ml to 40 mIU/ml, and the ratios of CSF/serum C_max ranged from 3.6×10^–4 to 10.2×10^–4. The terminal half-life (t_1/2) values of EPO in serum and CSF were similar. The t_1/2 of r-HuEPO in the CSF ranged from 25.6 h to 35.5 h after a single dose of 1,500 IU/l. Using these parameters a PK model was generated that predicts the concentration-time profile of EPO in the CSF.Conclusions We report that r-HuEPO can cross the human BBB and describe for the first time the PK of EPO in the CSF after IV administration. Our data suggest that the concentration-time profile of EPO in the CSF can be predicted for individual patients if the serum concentration of EPO and the Q_A are known. This information may be useful in the design of clinical trials to explore the potential therapeutic effects of EPO during CNS injury.