有机修饰改性对旱地土壤吸附镉离子特性的影响

研究了以不同比例十六烷基三甲基溴化铵(CTMAB)单一修饰和十六烷基三甲基溴化铵 十二烷基磺酸钠(CTMAB SDS)混合修饰土娄土耕层对重金属镉离子吸附的影响,结果表明:吸附量顺序为耕层原土>50%CTMAB>100%CTMAB 20%SDS>100%CTMAB,温度升高,吸附量上升;最佳吸附等温线模型可以用BET模型描述,热力学参数的研究表明,吸附自发性与吸附量具有相同的变化规律,反应的焓变与熵变共同决定了反应的自发性。从热力学角度对修饰改性土娄土对Cd2 吸附的机理进行了探讨。     

Expression of cyclooxygenase-2 in IL-1β-stimulated mesangial cells is medicated by NF-κB/IκB signal pathway

AIM: To investigate the role of NF-κB/IκB signal pathway in the regulation of cyclooxygenase-2 (COX-2) expression in human mesangial cells (HMC). METHODS: The PGE₂ concentration in supernatants of HMC was measured by radioimmunoassay. COX-2 mRNA and protein expression were determined by RT-PCR and Western blot. Electrophoretic mobility shift assay (EMSA) and Western blot were used to detect the activity of NF-κB and degradation of IκB. RESULTS: IL-1β significantly upregulated COX-2 expression and PGE₂ production in HMC. Significant up-regulation of NF-κB activation, nuclear translocation of p65 subunit, and degradation of IκB α and IκB β were observed in IL-1β-induced HMC. CONCLUSION: Expression of COX-2 in IL-1β-induced HMC is mediated by NF-κB/IκB signal pathway.     

Regulation of MMP-2 and TIMP-3 expression by uPA signal transduction system in human bone giant cell tumor

AIM: To study effects of urokinase-type plasminogen activator (uPA) signal transduction on expression of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of matrix metalloproteinase-3 (TIMP-3) in giant cell tumor of bone (GCT). METHODS: Expression of uPAR, MMP-2 and TIMP-3 in GCT tissue was detected by immunohistochemistry. Phosphorylation level of mitogen-activated protein kinase (p44) in uPA/uPAR signal pathway in cultured GCT cells was detected by immunoprecipitation. The expression of MMP-2 and TIMP-3 in cultured cells after treatment with uPA-ATF or anti-uPAR antibody was also detected by Western blotting. RESULTS: 1) Urokinase-type plasminogen activator receptor (uPAR) was positive on the cell membrane and in cytoplasm of some mononuclear stromal cells (MSCs) and multinucleated giant cells (MGCs); 2) MMP-2 was positive in the cytoplasm and on the cell membrane of almost all of MSCs and some of MGCs. The polar distribution of MMP-2 in the cytoplasm of MGCs was especially obvious; 3) The expression of TIMP-3 of some MSCs and MGCs in GCT was much lower than MMP-2. The positive signal also showed a prominent polarity; 4) After treatment with uPA-ATF, the phosphorylation level of p44 in GCT cultured cells was much higher than the control. Addition of anti-uPAR antibody in the cells remarkably down-regulated the phosphorylation level of p44 as compared with the control group, suggesting that uPA-ATF participates cell signal transduction and this reaction can be inhibited by anti-uPAR antibody; 5) uPA-ATF cell signal pathway up-regulated expression of MMP-2 and TIMP-3, while anti-uPAR antibody down-regulated the expression of MMP-2 and TIMP-3. CONCLUSION: These results demonstrate for the first time that uPA-ATF directly regulates the expression of MMP-2 and TIMP-3 by signal transduction pathway, and the over-expression of MMP-2 and TIMP-3 may play an important role in local osteolysis of GCT.     

苦皮藤素类似物的合成与结构鉴定

以苦皮藤Celastrus angulatus Max.提取物水解产物中的多羟基β-二氢沉香呋喃为原料,合成了对粘虫Mythimna separata具有毒杀活性的苦皮藤素(Celangulin)类似物,并在活性追踪的指导下分离得到了两个具有杀虫活性的苦皮藤素类似物 A和B, 其结构经核磁共振谱、快原子轰击质谱、高分辨质谱等波谱学方法鉴定为2β,6α,8β,13-四异丁酰氧基-1β,4α,9α-三羟基-β-二氢沉香呋喃及1β,2β,6α,8β,13-五异丁酰氧基-4α,9α-二羟基-β-二氢沉香呋喃。化合物 A和B 均为新化合物,在20 mg/mL的浓度下对三龄粘虫Mythimna separata的胃毒活性(死亡率)分别为89.5%和93.2%。     

Astrocyte proliferation in the rat hippocampus after middle cerebral artery occlusion

AIM: To study rat astrocyte proliferation in ipsilateral hippocampus following focal cerebral ischemia. METHODS: Ischemia was induced by temporary middle cerebral artery occlusion (MCAO). In hippocampus of rats at 3, 7 and 30 days after MCAO, the numbers and anatomic distribution of glial fibrillary acidic protein (GFAP) were detected by immunohistochemistry. The protein expression of GFAP and proliferating cell nuclear antigen (PCNA) in the ipsilateral hippocampus were analyzed by Western blot analysis. RESULTS: Astrocytes appeared hypertrophic, with increased process thickness and numbers at 7 days after MCAO, and the highest density of astrocytes were seen at 30 days in the CA1, CA2 regions of the ipsilateral hippocampus. Western blot analysis revealed that GFAP levels were normal at 3 days, but increased by 7 days and remained elevation at 30 days. Western blot analysis of PCNA protein also revealed identified upregulation PCNA at 3 days after MCAO and the expression peaked at 7 days. CONCLUSION: This study demonstrates that focal cerebral ischemia in the rat results in a rapid response, a process often referred to as reactive astrogliosis or glial scarring, from resident astrocytes of the ipsilateral hippocampus to the side of ischemia.     

Effects of β-ME and RA on expression of GFAP in mesenchymal cells derived from mouse fetal liver

AIM: To investigate the effects of β-mercaptoethanol (β-ME) and all-trans rentinal acid (RA) on glial fibrillary acidic protein (GFAP) expression in mesenchymal cells derived from mouse fetal liver in vitro. METHODS: Cells suspension from 14.5-days-old mouse fetal liver were cultured in DMEM/HEPES/F12 supplemented with 20％ FCS and mesenchymal cells were acquired after discarding nonadherent cells. The 5th passage cells were induced by β-ME and RA. The characteristics of treated cells were assayed by immunocytochemistry staining at 5 hours and 5 days after induction. β-actin as an internal control, GFAP gene expression of mesenchyal cells was detected with semi-quantitative RT-PCR. RESULTS: After being inducted by β-ME and RA, 80％ approximately of the cells exhibited typical neural morphology and about 85％ expressed GFAP phenotype. Semi-quantitative RT-PCR showed that mRNA expression of GFAP increased in treated cells versus untreated cells (P<0.01). CONCLUSION: GFAP expression in mesenchymal cells derived from mouse fetal liver in vitro increases after being treated with β-ME and RA.     

人胰岛素原基因转染绵羊成纤维细胞及细胞株的建立

从动物耳皮肤组织采样 ,采用将组织块剪碎后直接贴附于培养瓶底部的方法进行原代培养 ,该方法使原代细胞出现率及可传代率均达到 10 0 %。根据上皮样细胞和成纤维样细胞贴壁紧实程度的不同 ,用 0 .0 5 %的胰蛋白酶-EDTA对其进行消化 ,可将两种不同类型的细胞进行分离和纯化。通过脂质体介导 ,以BLG -hINS(含乳球蛋白调控基因的人胰岛素原基因 )基因作为目的基因、GFP(绿色荧光蛋白 )基因作为标记基因共转染绵羊成纤维细胞 ,经G - 4 18筛选后 ,得到转染细胞。对转染的细胞分别用单细胞显微操作法和有限稀释法进行细胞克隆 ,两种方法均可得到克隆细胞。选形态正常、生长均匀的 5个细胞克隆进行PCR检测 ,结果 5个克隆均转有GFP基因 ,其中两个转有BLG -hINS基因。高代培养细胞、转染细胞和克隆细胞经核型分析后 ,染色体数目均为 2 7对 ,表明绵羊耳的成纤维细胞建立细胞株后 ,可以作为外源基因转染的有效供体细胞。     

融合表达淋巴细胞脉络丛脑膜炎病毒和卵清白蛋白CD8+T细胞表位的减毒鼠伤寒沙门氏菌的构建与鉴定

依据淋巴细胞脉络丛脑膜炎病毒(LCMV)主要保护性抗原CD8 T细胞表位VRRPQASGVYMGNLTAQ和卵清白蛋白(OVA)CD8 T细胞表位SIINFEKL,设计、合成两条编码LCMV和OVA CD8 T细胞表位的寡核苷酸片段,经退火后,克隆入绿色荧光蛋白表达质粒pYAGFP,经PCR扩增和序列测定分析,证实成功构建T细胞表位与绿色荧光蛋白融合表达的重组质粒pYAGFPL-O,将此重组质粒pYAGFPL-O转化减毒鼠伤寒沙门氏菌X4550,获得重组沙门氏菌X4550(pYAGFPL-O).用SDS-PAGE电泳测得重组菌表达的融合蛋白约为30kD.同时,荧光显微镜下观察到X4550(pYAGFPL-O)发出黄绿色荧光.这些结果表明LCMV和OVA T细胞表位已成功表达.重组菌X4550(pYAGFPL-O)的获得为研究沙门氏菌载体携带外源抗原的T细胞应答规律及调控机理打下了重要基础.     

Results from the treatment of advanced stage squamous cell carcinoma of the nasal planum in cats, using a combination of intralesional carboplatin and superficial radiotherapy: a pilot study

Six cats with an advanced stage squamous cell carcinoma (SCC) of the nasal planum were treated with a combination of superficial radiotherapy and intralesional carboplatin therapy. This multimodality protocol was well tolerated by the majority of cats and resulted in complete responses in all cats (100%). Median follow‐up for all cats is 268 days, and the median time‐to‐recurrence, time‐to‐progression and overall survival have not yet been reached. Our study, although limited in number of animals and with a relatively short median follow‐up compared to other studies for this disease, suggests that a combination of radiotherapy and intralesional carboplatin is a useful treatment option for an advanced stage SCC of the nasal planum in cats and warrants further application of the multimodality approach presented here.     

Footsteps from Insect Larvae Damage Leaf Surfaces and Initiate Rapid Responses

Plant resistance to insect herbivory involves gene expression in response to wounding and the detection of insect elicitors in oral secretions (Kessler and Baldwin, 2002, Ann. Rev. Plant/ Biol. 53: 299–328). However, crawling insect larvae stimulate the synthesis of 4-aminobutyrate within minutes and imprints of larval footsteps can be visualized within seconds through superoxide production or transient increases in chlorophyll fluorescence (Bown et al., 2002, Plant Physiol. 129: 1430–1434). Here cryo-scanning electron microscopy was used to demonstrate that larval feet, which are equipped with a perimeter row of hook-like crochets, damage leaf tissue and result in larval footprints. Staining for cell death shows that areas of wounding correspond to footsteps detected through increased chlorophyll fluorescence. Superoxide production in response to footsteps was inhibited by diphenyleneiodonium, an inhibitor of the plasma membrane NADPH oxidase enzyme. Inhibition of superoxide production, however, did not eliminate the detection of cell death. The results demonstrate that larval footsteps damage leaf tissue, and initiate rapid local responses which are not dependent on herbivory or oral secretions. It is proposed that superoxide production at the wound site prevents opportunistic pathogen infection.