Comparison of assays for determination of peptide content for lyophilized thymalfasin*

Abstract: Precise determination of the peptide content in drug substance samples depends highly upon the particular peptide compound and methodology used. Four independent methods were evaluated and compared to determine which would produce the best experimental precision for analysis of thymalfasin (thymosin α‐1). Four different methods were evaluated including elemental analysis (CHN), quantitative amino acid analysis (AAA), high‐performance liquid chromatography (HPLC), and Kjeldahl. This study demonstrates that the AAA method is highly variable in one laboratory while quite precise in another laboratory. Similarly, HPLC results depended on the laboratory conducting the study with more precise values obtained under cGMP. On the contrary, the CHN method yielded highly precise [i.e. <2% coefficient of variation (CV)] values. As precise knowledge of protein content is fundamental for the compounding of final pharmaceutical product of a specific potency, the CHN analysis is recommended for peptide content determination of the drug substance thymalfasin.     

以乙二胺为核心的聚酰胺-胺树形高分子的合成及毛细管电泳分离研究

在-30℃下合成了1．0G～6.0G聚酰胺．胺(PAMAM)树形高分子，并采用核磁共振、元素分析对其进行了表征；采用毛细管电泳对1．0GPAMAM进行了分离。结果表明：在该温度下合成的PAMAM具有较好的结构完整性，而毛细管电泳是一种有效的分离提纯PAMAM树形高分子的方法。     

提高H2O2/甲酸体系选择性氧化抽提脱硫效率的研究

为了降低焦化蜡油(CGO)-甲酸／H2O2选择性氧化体系中H2O2的无效分解速度，屏蔽重金属离子对H2O2分解的催化效应，考察了造纸行业中常用的硅酸钠、硅酸镁和乙二胺四乙酸(EDTA)等稳定剂和螯合剂的加入对有机溶剂抽提后CGO中含硫量的影响。实验结果表明，EDTA可以很好地和重金属离子螯合，氧化后CGO抽余油中硫含量大幅降低。     

Computer simulations and the use of radiolabelled sulphur colloid to measure the efficiency of the mononuclear phagocyte system

Technique are described whereby the clearance of the radiolabelled blood borne colloid can be continuously and reproducibly measured non-invasively from the same animal in vivo or from the isolated perfused intact liver in vitro. Using these techniques, the rate of removal of radiolabelled sulphur colloid by the mononuclear phagocytes in vivo and in vitro was shown to be biexponential. The pattern of clearance of colloid and the factors contributing to this were analysed with the aid of a computer program which mimicked the in vitro liver perfusion.     

二氧化硫吸入对小鼠脾细胞凋亡的诱导作用

目的:探讨二氧化硫大剂量吸入对小鼠脾细胞凋亡和脾脏组织学结构的影响.方法:以不同浓度的二氧化硫分别对小鼠连续染毒7d,用透射电镜法、DNA琼脂糖凝胶电泳法和流式细胞技术观察小鼠脾脏组织学结构和细胞凋亡改变.结果:在二氧化硫染毒组小鼠脾脏的红髓区和白髓区均有典型的脾细胞凋亡发生,在边缘区可见大量核变形淋巴细胞,此外还可见巨噬细胞出现明显的凋亡改变和网状内皮细胞受损.168mg/m3二氧化硫染毒可引起小鼠脾细胞凋亡率增加.结论:大剂量二氧化硫吸入可引起小鼠脾脏超微结构改变,在一定剂量和时间范围内可引起脾细胞凋亡加速,从而对机体的免疫功能造成一定损伤.     

Effect of intrajejunal elemental diet perfusion on local secretion of soluble CD4 and CD8

The effects of nutrients on the mucosal immune system are poorly understood. The aim of this work was to study the cellular mucosal immune response to intrajejunal perfusion of an elemental diet (ED) or a control (C) electrolyte solution by measuring jejunal secretion of soluble CD4 (sCD4) and sCD8. sCD4 and sCD8 are markers of helper/inducer and suppressor/cytotoxic regulatory functions of T cells, respectively. A four lumen tube with a proximal occluding balloon at the angle of Treitz was used for jejunal perfusion in seven healthy volunteers (mean age 23 years). The length of the test segment was 40 cm. The jejunum was successively perfused with C for 80 min and then with ED containing 21.3g/l of free amino acids and 104.2g/l of oligosaccharides for 100 min. Jejunal fluid and serum concentrations of sCD4 and sCD8 were measured and their jejunal outputs calculated. When compared with C perfusion, jejunal perfusion with the ED resulted in a significant increase of sCD8 but not sCD4 jejunal secretion rates. sCD8 jejunal values increased early after ED perfusion and stayed at roughly the same level during the perfusion. Serum concentrations of sCD4 and sCD8 were not modified during ED perfusion. These data support the hypothesis that ED suppresses the immunologic tone of the gut, which could explain its beneficial effect in the management of intestinal inflammatory disease.     

rhEPO、rhG-CSF对芥子气全身吸收中毒犬疗效观察

目的　评价重组人红细胞生成素 (rhEPO)、重组人粒细胞集落刺激因子 (rhG CSF)对芥子气全身吸收中毒犬的治疗效果。方法　以成年家犬为中毒模型 ,共 10条 ,中毒剂量为 12mg kg,皮下注射。随机分为中毒对照组 4条 ,治疗组 6条 ,治疗组动物在中毒后 30min即进行相应的药物治疗。中毒前所有犬各测一次血常规的基础值 ,中毒后每日监测血常规的动态变化 ,持续 1周。结果　对照组犬于 3天内死亡 3条 ,治疗组犬全部成活。对照组白细胞计数 (WBC)在中毒后第 3开始剧烈下降 ,红细胞计数 (RBC)在中毒后即有轻度上升 ,之后回落 ;而治疗组WBC、RBC在中毒后 1周内均无显著变化。两组的淋巴细胞计数 (LYM)在中毒后都有显著下降 ,治疗组稍好于对照组。治疗组的网织红细胞计数 (RC)于中毒后第 2天开始显著增长 ,之后维持在高水平 1周左右。治疗组的RC变化不明显。结论　犬芥子气中毒后 ,应用rhEPO、rhG CSF能明显改善中毒犬的部分血常规指标     

Application of LC/MS to determine specific activity variation in a series of sulfonamide tracers from the [35S]methane sulfonate reagent

The specific activities for a series of S‐35 tracers were found to vary from the decay‐corrected specific activity of the labeled reagent. If not known before the stock solution preparation and binding assay, this variation would have resulted in performing the assay at approximately two to three times over the targeted concentration, thereby leading to considerable error in the calculated binding and related conclusions. Copyright © 2012 John Wiley & Sons, Ltd.     

Physiological and inflammatory responses in an anthropomorphically relevant model of acute diesel exhaust particle exposure are sex and dose-dependent

Context: Diesel exhaust particles (DEP) are an important contributor to suspended particulate matter (PM) in urban areas. While epidemiological evidence exists for a sex-influenced dose-response relationship between acute PM exposure and respiratory health, similar data are lacking for DEP. Further, experimental evidence showing deleterious effects on respiratory health due to acute DEP exposure is sparse.

Objective: To establish and characterize a mouse model of acute DEP exposure, comparing male and female mice and assessing the kinetics of the elemental carbon content of alveolar macrophages (AMs) to relate our model to human exposure.

Materials and Methods: Adult BALB/c mice were intranasally inoculated with 0 (control), 10, 30 or 100 µg DEP in saline. Bronchoalveolar lavage cellular inflammation and cytokine levels were assessed 3, 6, 12, 24, 48 and 168 hours post exposure. Elemental carbon uptake by AMs was additionally assessed at 336 and 672 hours post DEP exposure. Thoracic gas volume and lung mechanics were measured 6 and 24 hours post exposure. Results: DEP resulted in dose-dependent cellular inflammation and cytokine production in both sexes. Males and females responded differently with females having more severe and prolonged neutrophilia, monocyte chemoattractant protein-1 and developing greater abnormalities in lung function. The sexual dimorphism in response was not related to the capacity of AMs to phagocytise DEP.

Conclusions: Our mouse model of acute diesel exhaust particle exposure shows a dose dependency and sexual dimorphism in response. Quantification of elemental carbon in AMs allows for comparison of the results of our study with human studies.