电离辐射与淋巴细胞

早期的临床工作是了解淋巴细胞的辐射剂量与效应关系,作为初期最敏感的指标之一。对原子弹受害者的淋巴细胞也进行了远期效应的观察。实验室工作方面研究了淋巴细胞的活力、死亡率,玫瑰花结、细胞膜和DNA等分子的变化。染色体畸变,微核率及其相互关系的研讨也引起人们重视。 应用PHA、ConA、PWM、LPS分别激活淋巴细胞的各个亚群,研究其辐射效应。有关PHA激活的T淋巴细胞的辐射效应研究得较多。作者察觉PWM和ConA激活的淋巴细胞对辐射敏感,均减弱了辅助B淋巴细胞转化的作用,PHA激活的淋巴细胞受影响较轻,LPS激活的淋巴细胞变化最小。 单克隆抗体技术研究淋巴细胞亚群的进展为进一步研究淋巴细胞的辐射效应提供条件,可以了解辐射影响免疫功能的主要环节。 有的作者研究了各种病人的淋巴细胞的辐射敏感性,以了解免疫方面存在的缺陷,还可作为制定辐射治疗某些白血病方案的依据。     

栀子油对ConA诱导的小鼠急性免疫性肝损伤的保护作用

研究栀子油对刀豆蛋白A(ConA)诱导的小鼠免疫性肝损伤的保护作用,并探讨其作用机制。将小鼠随机分成空白组、模型组、联苯双酯组,栀子油低、中、高剂量组,各给药组每天给药1次,连续给药10 d,末次给药1 h后,除空白组外,其他各组尾静脉注射ConA(15 mg/kg),制备小鼠急性免疫性肝损伤模型。测定小鼠血清中ALT、AST和LDH的含量及肝脏组织匀浆中SOD活性和NO、MDA的含量,RT-PCR检测肝组织中TNF-α、CXCL-10 mRNA和IFN-γmRNA的表达量,HE染色观察肝组织的病理学变化。结果表明:与模型组相比,栀子油各剂量组均能降低血清ALT、AST和LDH的含量,提高SOD活性,降低肝组织NO、MDA的产生,下调TNF-α、CXCL-10mRNA和IFN-γmRNA的相对表达量,肝组织变性及坏死等病理症状明显改善,尤以栀子油高剂量组效果最佳。栀子油对ConA诱导小鼠免疫性肝损伤有明显的保护作用,其保肝的机制可能与提高抗氧化酶体系活力,抑制氧化应激反应及炎性因子表达有关。     

Acetyl‐α‐d‐mannopyranose‐based cationic polymer via RAFT polymerization for lectin and nucleic acid bindings

Functional cationic polymers carrying mannose moieties were synthesized in a facile manner by employing RAFT polymerization. Initially, a protected carbohydrate based monomer, [2‐(2,3,4,6‐tetra‐O‐acetyl‐α‐d ‐mannopyranosyloxy)ethyl methacrylate (AcManEMA)], was prepared by the O‐glycosylation of 2‐hydroxyethyl methacrylate (HEMA). Subsequently, a macroRAFT agent of poly[2‐(dimethyl)amino ethyl methacrylate] (PDMAEMA) was generated, and a further chain extension polymerization with AcManEMA was carried out in dioxane to form a acetylated mannose cationic diblock copolymer, PDMAEMA‐b‐PAcManEMA. It was attained in high yields and displayed low dispersity (Ð). Acetylated mannose moieties on the polymer were deprotected with sodium methoxide and the amines from the DMAEMA block were protonated to yield a cationic diblock glycopolymer, PDMAEMA‐b‐PManEMA. The cationic property of polymers were characterized by mixing with a negatively charged siRNA duplex and a pDNA, and aggregates of 102 and 233 nm were obtained, respectively. Agarose gel shift assay revealed that the polymers were able to retain the nucleic acids as large polymer complexes. Lectin binding assay proved that the mannose residue on the polymers were only able to bind specifically with ConA. PNA lectin was employed as a control and did not show specific binding. The cationic glycopolymer could be advantageous in targeted nucleic acids delivery in specific cells. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44947.     

ATRP in the design of functional materials for biomedical applications

Atom Transfer Radical Polymerization (ATRP) is an effective technique for the design and preparation of multifunctional, nanostructured materials for a variety of applications in biology and medicine. ATRP enables precise control over macromolecular structure, order, and functionality, which are important considerations for emerging biomedical designs. This article reviews recent advances in the preparation of polymer-based nanomaterials using ATRP, including polymer bioconjugates, block copolymer-based drug delivery systems, cross-linked microgels/nanogels, diagnostic and imaging platforms, tissue engineering hydrogels, and degradable polymers. It is envisioned that precise engineering at the molecular level will translate to tailored macroscopic physical properties, thus enabling control of the key elements for realized biomedical applications.     

刀豆素A诱导巨噬细胞受体介导内吞及溶酶体过程

本文采用电子显微镜对胶体金标记刀豆素与小鼠腹腔巨噬细胞表面ＣｏｎＡ受体的结合、内吞及春在巨噬细胞中转运的形态学变化；同时采用共聚焦对巨噬细胞内Ｃａ＾２＋和ＰＨ的动态变化进行了观察。     

Antifungal and antibacterial activities of lectin from the seeds of Archidendron jiringa Nielsen

A Archidendron jiringa Nielsen lectin was purified by aqueous extraction, 90% ammonium sulphate precipitation and concanavalinA-Sepharose 4B affinity chromatography. Its specific activity was of 88.3 × 10² hemagglutination unit/mg protein for a yield of 51.6% total protein. The molecular weight is of 35.7 kDa. It has hemagglutinating activity against human blood group, rabbit, mouse, rat, guinea pig, geese and sheep erythrocytes. The hemagglutination activity of lectin was relatively insensitive to acidic pH above 2, had an optimal activity at pH 8, and stable below 45 °C for 30 min. The activity was stimulated by Ca²⁺, Mg²⁺ and Mn²⁺. The internal sequence indicated similarity with legume lectin family. Moreover, even at low concentrations antifungal activity was observed against Exserohilum turcicum, Fusarium oxysporum and Colletotrichum cassiicola. The minimal inhibitory concentrations were 0.227, 0.0567 and 0.0567 mg/ml for Bacillus subtilis, Staphylococcus aureus, and Candida albicans, respectively.     

γ线照后PHA、ConA和PWM激活的人血淋巴细胞转化、DNA单链断裂及其修复比较

本文采用~3H-TdR参入法和羟基磷灰石层析法,比较了~(60)Coγ射线照射后PHA、ConA、PWM激活的人血淋巴细胞的转化、DNA单链断裂及其修复,结果表明:受照后淋巴细胞转化受抑,在0—8Gy剂量范围内,剂量效应呈双相线性关系,其中PWM激活的细胞对射线的敏感性最低。三种细胞受照后DNA发生单链断裂,在0—30Gy范围内,与剂量呈线性相关,三者之间无显著差异。受15Gy照射后,细胞在37℃条件下能重接DNA断链,但重接不完全,重接后如经较长时间保温仍会发生再断裂,PWM激活的细胞重接修复率最高。淋巴细胞转化对辐射的敏感性可能与DNA断链的重接修复能力有关。     

Hepatocyte-Derived Igκ Exerts a Protective Effect against ConA-Induced Acute Liver Injury

Immunoglobulin (Igκ) has been reported to be expressed in sorted liver epithelial cells of μMT mice, and the sequence characteristics of hepatocyte-derived Igκ were different from those of classical B-cell-derived Igκ. However, the physiological function of hepatocyte-derived Igκ is still unclear. The expression of Igκ was firstly identified in primary hepatocytes and normal liver cell line (NCTC1469), and hepatocyte-derived Igκ expression was elevated and displayed unique localization in hepatocytes of concanavalin A (ConA)-induced hepatitis model. Moreover, Igκ knockout mice were more sensitive to ConA-induced hepatitis and had higher serum aspartate aminotransferase (AST) levels, more severe histological injury and a greater number of terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL)-positive cells as compared with littermate controls. Furthermore, knockdown of Igκ in primary hepatocytes and NCTC1469 cells led to accelerated activation of the mitochondrial death pathway and caspase-3 cleavage in vitro, which might be related to inhibition of NF-κB signaling pathway and activation of JNK via the cytoskeleton dynamics. Taken together, these results indicate that hepatocyte-derived Igκ mediates cellular resistance to ConA-induced liver injury by inhibiting activation of caspase-3 and the mitochondrial death pathway, suggesting that Igκ plays an important role in hepatocyte survival and exerts a protective effect against ConA-induced liver injury in mice.     

Complex macromolecular architecture design via cyclodextrin host/guest complexes

The design of complex macromolecular architectures has driven macromolecular engineering over the past decades. The introduction of supramolecular chemistry into polymer chemistry provides novel opportunities for the generation of macromolecular architecture with specific functions. Cyclodextrins are attractive design elements as they form supramolecular inclusion complexes with hydrophobic guest molecules in aqueous solution affording the possibility to combine a large variety of building blocks to form novel macromolecular architectures. In the present critical review, the design of a broad range of macromolecular architectures driven by cyclodextrin host/guest chemistry is discussed, including supramolecular block copolymers, polymer brushes, star and branched polymers.     

新型重组人肿瘤坏死因子-α对四氯化碳及刀豆蛋白A 诱导小鼠肝损伤的影响

目的:研究不同剂量的新型重组人肿瘤坏死因子(nrhTNFα)对肝功能及肝脏组织形态学的影响。方法:用四氯化碳(CCl4)或刀豆蛋白A(Con A)诱导小鼠肝损伤, nrhTNFα低、中、高剂量(5×10⁴, 5×10⁵, 5×10⁶ IU°kg^-1)im, 测血清中ALT、AST、LDH、IFN-α、IL-2 和NO 浓度变化, 检查肝脏组织形态学变化。结果:3 个剂量的nrhTNFαim 对正常小鼠肝功能及肝脏组织形态学无影响;低、中剂量nrhTNFα对CCl4 诱导肝损伤小鼠的肝功能及肝脏组织形态学无影响, 高剂量nrhTNFα加重肝损伤;3 个剂量的nrhTNFα降低Con A 诱导的肝损伤小鼠血清ALT、AST、LDH 和IFN-γ浓度增加, 且nrhTNFα低剂量作用明显, 能明显减轻肝脏病理学改变。结论:nrhTNFα低、中、高剂量im 对正常小鼠无肝毒性;nrhTNFα低、中剂量im 不影响CCl4 诱导的肝损伤,高剂量则加重之;3 个剂量的nrhTNFαim 抑制Con A诱导的肝损伤, 其作用机理与抑制Con A 诱导的小鼠IFN-γ产生有关。