二乙基二硫代氨基甲酸盐对Lewis肺癌转移小鼠的抑制作用

二乙基二硫代氨基甲酸钠(DDC)是超氧化物歧化酶(SOD)的抑制剂,是一有希望的癌化疗剂。迄今未见到其对癌转移作用研究的报道。本研究发现给动物注射不问剂量DDC后,体内的SOD活性明显降低,肺癌转移频率明显减少。 动物实验分3组:对照组:不给药;DDCⅠ组:C_(57)BL小鼠(二月龄,15～20g,购自北医大动物中心),注射DDC(北     

双歧杆菌DNA对J774A.1巨噬细胞的活化作用

双歧杆菌的细胞壁成分能有效的激活免疫细胞,促使这些效应细胞释放免疫活性物质,并对多种肿瘤的发生与发展具有一定的抑制作用。本研究利用我室提取的双歧杆菌DNA观察了其对小鼠J774A.1巨噬细胞的活化作用。收集厌氧培养的双歧杆菌(菌种由山东省防疫站提供),加入溶菌酶(1mgm1)与10%SDS(终浓度为1%)裂解菌体,饱和酚抽提去除菌体蛋白,透析,用紫外分光光度计测定所提取的双歧杆菌DNAA260/A280为1.823,经薄板层析证实所制备的双歧杆菌DNA中无脂多糖存在,经HpaⅡ酶酶切证实所制备的双歧杆菌DNA具有一定的非甲基化CpG基序,冷冻干燥后备用…     

解淀粉芽孢杆菌致BALB/c小鼠哮喘模型的建立

目的:探讨解淀粉芽孢杆菌或解淀粉芽孢杆菌培养液(代表细菌产物)是否导致BALB/c小鼠哮喘。方法:40只SPF级雌性BALB/c小鼠随机分为4组(每组10只),即对照组、卵清蛋白(OVA)组、培养液组、细菌组。于第0天、第7天用OVA小鼠腹腔注射致敏,从第14天到第28天用OVA液对小鼠进行雾化吸入激发,1次/d,每次30 min;对照组、培养液组、细菌组分别用生理盐水、细菌培养液、细菌进行致敏和激发试验。结果:实验表明OVA组和细菌组两组的活体肺功能(APTI)值均高于对照组;与对照组相比较,OVA组、细菌组两组的管壁厚度、肺泡灌洗液中白细胞总数、嗜酸性粒细胞百分比均有显著升高(P<0.01),而淋巴细胞百分比均显著降低,尤其是细菌组更加突出;与对照组比较,OVA组和细菌组的血清中IgE浓度均为显著升高(P<0.01)。结论:用解淀粉芽孢杆菌建立了BALB/c小鼠哮喘动物模型,并证明导致小鼠哮喘的主要因子是细菌。     

金宁益康口服液对细胞免疫、抗菌、SOD、MDA的研究

为了证实金宁益康口服液对细菌的抑制作用、提高细胞免疫及对小白鼠血超氧化物歧化酶(SOD)、脂质过氧化代谢产物丙二醛(MDA)的影响,运用药理生化的方法,观察五种不同浓度金宁益康口服液对金黄葡萄球菌、表皮葡萄球菌、肺炎双球菌、绿脓杆菌、大肠杆菌、变形杆菌的抑制作用和巨噬细胞吞噬活性以及观察用药1月后小白鼠血SOD、MDA的含量,并与对照组进行比较.结果表明该药有提高巨噬细胞的吞噬活性,对以上细菌具有较强的抑制作用,且浓度越大抑制作用越明显,具有一定的量效关系,明显提高小鼠血液中的SOD的含量,降低MDA,用药组与对照组比较差异显著P＜0.05～0.01.该药具有提高细胞免疫、抑菌、提高小鼠血液中SOD含量、降低MDA作用.     

双歧杆菌脂磷壁酸延缓脾脏衰老的研究

目的　研究双歧杆菌表面分子脂磷壁酸 (LTA)在D 半乳糖诱导的衰老小鼠体内 ,对脾脏指数和脾细胞DNA损伤的影响。方法　在建立D 半乳糖诱导的衰老小鼠模型的同时 ,注射双歧杆菌LTA ;然后测定模型对照组、正常对照组、试验组小鼠的脾脏指数 ,并以单细胞凝胶电泳试验检测脾脏淋巴细胞DNA氧化损伤的情况。结果　与正常对照组相比 ,模型对照小鼠的脾脏指数显著升高 (P <0 .0 5 ) ,脾淋巴细胞DNA受到了较严重的损伤 (P <0 .0 5 ) ;用双歧杆菌LTA处理后 ,试验小鼠的脾脏指数明显下降 (P <0 .0 5 ) ,脾淋巴细胞DNA的损伤程度显著降低 (P <0 .0 5 )。结论　双歧杆菌LTA能显著抑制衰老小鼠脾脏淋巴细胞DNA的氧化损伤 ,这可能与双歧杆菌抗衰老有关。     

旋转磁场对小鼠血清超氧化物歧化酶及肝组织过氧化物酶活性的影响

研究旋转磁场对小鼠血清超氧化物歧化酶及肝组织中过氧化物酶活性的影响。用转速为2000r／min,平均场强为0.09T的旋转磁场作用于小白鼠,血清SOD测定采用化学发光法,而肝组织POD测定采用愈创木酚比色法。经旋转磁场处理后小鼠血清SOD活性及肝组织中POD活性均较空白对照组增加,统计学处理采用t检验。结果表明实验组较对照组有显著差异。一定强度且作用一定时间的旋转磁场在一定程度上能提高生物机体抗氧化酶的活性。     

黄芪精口服液对大鼠抗疲劳作用研究

目的:观察黄芪精口服液对小鼠抗疲劳能力的影响。方法:选用单一雄性昆明种小鼠36只,随机分为空白对照组(生理盐水)、黄芪精口服液低剂量组(0.05g·10g-1)、高剂量组(0.1g·10g-1),每天按0.07ml·10g-1,0.14ml·10g-1灌胃一次,连续7d,记录小鼠游泳时间,并用分光光度计法检测小鼠剧烈运动后血尿素氮(BUN)含量、超氧化物歧化酶(SOD)活性。以小鼠游泳时间为指标研究其抗疲劳作用。结果:与对照组比较,高剂量黄芪精口服液可显著提高小鼠负重游泳时间,增加血浆SOD活性,降低BUN含量(P0.05)。结论:黄芪精口服液具有提高小鼠抗疲劳能力的作用。     

双歧杆菌、大肠杆菌总DNA对小鼠免疫功能影响的对比研究

目的提取双歧杆菌、大肠杆菌DNA,与iIEL细胞共同孵育,观察它们对IEL细胞的激活作用,并用DNA免疫小鼠,观察小鼠免疫功能的变化,探讨双歧杆菌、大肠杆菌DNA对免疫功能的影响,并作对比研究。方法以自然杀伤细胞（NK）活性,白细胞介素-2（IL-2）产生能力为指标,测定小鼠上述各项指标变化。结果小鼠以上两项指标与对照组相比有明显提高（P＜0.05）。双歧杆菌DNA提高小鼠NK活性与IL-2水平程度大于大肠杆菌DNA的作用（P＜0.01）。结论表明双歧杆菌DNA可快速激活NK活性,提高体内IL-2水平。其效能优于大肠杆菌DNA。     

双歧杆菌对溃疡性结肠炎小鼠肠黏膜内细胞因子表达和NF-κB激活的影响

目的　建立小鼠溃疡性结肠炎 (UC)动物模型 ;应用双歧杆菌活制剂 ,观察其对UC发生、发展的影响 ,并检测其对TNF α、IL 1β的表达和NF κB活性的影响。方法　用 5%葡聚糖硫酸钠(DSS)口饲法制备小鼠UC模型 ;给小鼠口服双歧杆菌 (Bifidobacterium ,Bf)活菌 ,观察UC的症状和组织学变化 ;采用逆转录 聚合酶链反应 (RT PCR)技术 ,检测UC小鼠肠黏膜内TNF α、IL 1β的表达水平进行半定量测定 ;应用免疫电泳迁移率改变分析 (electrophoreticmobilityshiftassay ,EMSA)法检测UC小鼠肠黏膜细胞NF κB的激活。结果　应用双歧杆菌制剂后 ,UC的症状、组织损害均较模型组明显减轻。同时TNF α、IL 1β的表达较单纯模型组降低 (P <0 .0 5) ,NF κB的核结合活性也降低 ,但较正常对照组仍明显增加。结论　生态制剂Bf对UC的发生有预防作用 ,可能是通过抑制NF κB的核结合活性 ,进而降低致炎细胞因子的表达完成的     

丹参对缺血心肌的保护作用

目的:通过观察丹参注射液(DSZ)对缺血心肌细胞各项生化指标的影响,探讨其对心肌保护作用及其机制。方法:将小鼠随机分为四组,以40%丹参注射液0.25ml/10g灌胃处理,一周后腹腔注射垂体后叶素(Pit),复制心肌缺血模型,观察小鼠心肌组织一氧化氮合酶(NOS)及超氧化物岐化酶(SOD)活性、脂质过氧化物丙二醛(MDA)的含量、血清肌酸激酶(CK)活性。结果:DSZ预处理小鼠心肌组织NOS、SOD活性显著增加,而MDA的含量及血清CK活性显著降低(P<0.01)。结论:丹参减轻心肌缺血引发的损伤,保护心脏,其作用机制可能与增加缺血心肌组织NOS、SOD活性,减少MDA含量和血清CK活性有关。     

The effects of diethyldithiocarbamate,a SOD inhibitor,on endothelial function in sedentary and exercised db/db mice

The study was designed to evaluate the effects of diethyldithiocarbamate (DDC), an superoxide dismutase (SOD) blocker on endothelial function in db/db mice. The db/db and wild-type (WT) mice were randomly divided into low intensity exercise, moderate intensity exercise and control (sedentary) groups. Mice were exercised daily, 5 days per week. After 6 weeks, ring segments of aortae were mounted in wire myograph and acetylcholine (ACh) concentration response curves were recorded in absence or presence of DDC and DDC plus SOD.Results showed that ACh concentration response curve was similar in WT and WT exercised groups. Incubation of aorta rings of WT mice with DDC suppressed the maximum ACh response (p < 0.05). Subsequent incubation with SOD restored vasodilatory response in WT mice. The vasodilatation to ACh was significantly reduced in sedentary db/db mice compare to WT (p < 0.05) and incubation with DDC did not further decrease this response, however, addition of SOD restored the vasodilatation to ACh to that observed in WT mice. Mild and moderate exercised db/db mice had ACh response similar to that in WT mice. Incubation with DDC incubation reduced ACh induced vasodilatation and addition of SOD restored this response.Our results support the conclusion that SOD mimetics can be used to improve superoxide-mediated endothelial dysfunction in diabetic db/db mice.     

CYP2E1 inhibition enhances mallory body formation

Mallory body (MB) formation is a complex phenomenon seen in chronic liver disease. CYP2E1 may play a role in preventing MB formation since it is involved in the elimination of toxic drugs and chemicals. When mice were fed with diethyl-1,4-dihydro-2,4,6-trimethyl-3,5-pyridinedicarboxylate (DDC) for 10 weeks, Mallory bodies (MBs) developed in the liver at the end of this period. When DDC feeding was combined with CMZ (an efficient in vivo CYP2E1 inhibitor), more MBs formed compared to DDC feeding alone. DDC was shown to be a suicide inhibitor of CYP2E1. The level of CYP2E1 protein in the liver was further reduced by the DDC and CMZ treatment when measured by Western blot. To test whether CYP2E1 reduced MB formation, CYP2E1 knockout mice and CYP2E1 overexpressed mice were fed with DDC or DDC and CMZ for 10 weeks. MB formation increased markedly in the liver of CYP2E1 knockout mice when fed with DDC only. CYP2E1 overexpressed mice showed an increase in MB formation when the mice were fed with the combination of DDC and CMZ where the amount of CYP2E1 was reduced to levels seen in wild type mice. It was concluded that CYP2E1 inhibits MB formation by increasing the rate of elimination of DDC and/or its toxic intermediates.     

SOD活性与肺癌细胞染色体异常及DNA合成关系的研究

用ＳＯＤ及其活性抑制剂分别提高和降低体外培养的Ａ５４９肺癌细胞内的ＳＯＤ活性，以达到改变细胞内自由基浓度的目的，动态地观察了ＳＯＤ活性与肺癌细胞的染色体核型、畸变率、Ｓ期细胞比率和细胞增殖指数变化之间的关系。结果，受ＳＯＤ处理的细胞其Ｓ期细胞比率由第１天的６３．４下降到第５天的３８．０，增殖指数由第１天的０．６６下降到第５天的０．４４；培养后第１６天的细胞染色体畸变率明显减少，染色体的干系范围由对照组的５６～６０条下降到４０～５５条。而受ＳＯＤ活性抑制剂处理的细胞的染色体畸变率明显增高，并表现出一定的毒性变化。结果提示，在细胞生物学水平上，提高细胞内ＳＯＤ活性可以部分地促进人肺癌细胞的某些遗传表型向正常方面转化，而降低ＳＯＤ活性则可增加细胞毒性损害作用。     

Mallory body (cytokeratin aggresomes) formation is prevented in vitro by p38 inhibitor

Microarray analysis of livers from mice fed diethyl-1,4-dihydro-2,4,6-trimethyl-3,5-pyridinedicarboxylate (DDC) to induce Mallory body (MB) cytokeratin aggresome formation showed that gene expression for cellular adhesion molecules, cytokeratins, kinases and aggresome forming proteins were upregulated, when MBs were formed in vivo. This response was enhanced when the DDC was refed (mice fed DDC for 10 weeks followed by DDC withdrawal for 1 month, then refed DDC for 7 days). Immunofluorescent antibody staining of the MBs that formed showed that MAPK p38 was colocalized with ubiquitin and p62 in the MBs. To investigate further the mechanisms of MB formation, primary cultures derived from DDC primed mice and their controls were incubated for 6 days. Liver cells cultured for 3 h and 6 days were used for microarray analysis. At 3 h, there were no MBs formed, but MBs were numerous after 6 days of culture. At 3 h, the expression of a large number of genes was different when the control, and the DDC primed hepatocytes were compared, which indicates that the primed hepatocytes were phenotypically changed. The gene expression of many kinases including p38 was upregulated after 6 days where the gene expression of cytokeratins, adhesion molecules and aggresome forming proteins were upregulated when MBs formed. An inhibitor of p38 phosphorylation (SB202190) completely prevented MB formation. Western blot showed that phosphorylated p38 MAPK and total p38 were absent in vitro after the p38 inhibitor treatment. Immunostaining of 6-day DDC-primed hepatocyte cultures stained with antibodies to p62 and phospho-p38 MAPK showed that phosphorylated p38 MAPK was concentrated within the MBs. Antibodies to specific serine phosphorylated sites 73 and 431, located in cytokeratin 8, localized to Mallory bodies in vivo, indicating that cytokeratin 8 was hyperphosphorylated. The data supported the concept that MBs form as the result of hyperphosphorylation of cytokeratin 8 by p38.     

Decreased survival of prostate cancer cells in vitro by combined treatment of heat and an antioxidant inhibitor diethyldithiocarbamate (DDC)

The aim of this study was to examine a modulation of thermotolerance by treatment with combination of heat and the antioxidant inhibitor diethyldithiocarbamate (DDC) of the PC-3 prostate cancer cells. To determine thermotolerance, cells were heated once or twice. Two 1 h exposures at 43 degrees C, with a recovery period in between, revealed better survival/recovery of cells after the second exposure than after the first (fig. 1A + 1B). Additional experiments were performed, heating cells twice (fig. 1B + 1C). First, cells were heated at 43 degrees C for 1 h and, after various recovery times (intervals) at 37 degree C, subsequently reheated at 44 degrees C for 1 h. To ensure effective cell killing, efficiency of the combined treatments of 1 mM DDC and heating at 43 or 44 degrees C for 1 h was estimated by measuring cell survival, reactive oxygen species (ROS) generation, superoxide dismutase (SOD) activity and heat shock protein 70 (hsp 70) expression. To obtain a more effective method for subsequent heat exposure, cells were heated twice after a 24 h interval in the presence or absence of 1 mM DDC. ROS generation and SOD activity immediately increased correlating with duration of heating, but their levels gently decreased with time after discontinuation of heating. On the other hand, hsp 70 levels slowly increased, also correlating with duration of heating but continued to increase with time after discontinuation of heating for a certain period. DDC administration coupled with heating at 43 or 44 degrees C significantly decreased cell survival compared to heating alone (p < 0.05). Furthermore, significant decreases in numbers of viable cells were observed for cells after the first heat exposure when combined with DDC as compared to heat alone at 43 and 44 degrees C (p < 0.05). These findings suggest that heat combined with DDC could have potential benefits in the treatment of prostate cancer.     

Generation of reactive oxygen metabolites by the haemocytes of the mussel Mytilus edulis.

Generation of superoxide anion by stimulated haemocytes of Mytilus edulis was demonstrated using dihydrorhodamine 123 and quantified using reduction of nitroblue tetrazolium (NBT). In the presence of zymosan or phorbol myristate acetate, there was an increased reduction of NBT to formazan. The addition of superoxide dismutase (SOD) and iodoacetamide to the incubation medium resulted in a significant reduction in deposition of reduced formazan. Incubation of haemocytes with the SOD inhibitor diethyldithiocarbamate (DDC) gave rise to a small but significant increase in NBT reduction. The production of hydrogen peroxide by haemocytes was quantified using horseradish peroxidase-dependent oxidation of phenol red. The presence of SOD in the incubation medium together with zymosan resulted in a significant increase in H2O2 production. Haemocytes incubated with DDC prior to the assay or with sodium nitroprusside during the assay showed a decrease in H2O2 production with increasing concentration of the inhibitor.     

Upregulation of Polymeric Immunoglobulin Receptor Expression by the Heat‐Inactivated Potential Probiotic Bifidobacterium bifidum OLB6378 in a Mouse Intestinal Explant Model

We determined whether a potential probiotic bacterium, Bifidobacterium bifidum OLB6378 (BB6378), exerts beneficial effects on the mucosal immune system in a mouse intestinal explant model. The addition of heat‐inactivated BB6378 to intestinal explants prepared from embryonic day 18 BALB/c mice increased the expression of polymeric immunoglobulin receptor (pIgR) mRNA by two‐ to fivefold. These effects were observed on ileal and colonic explants but not on jejunal explants, suggesting that the BB6378‐induced pIgR upregulation is site‐specific within the mouse intestine. The upregulation of pIgR protein expression in colonic explants was also detected after 24 h of culture. The results of DNA microarray analysis of ileal and colonic samples indicated that BB6378 increased the gene expression of interleukin (IL)‐1α and IL‐1β, and IL‐1α content in colonic explants was significantly increased after 20 h of culture with BB6378. We then examined the involvement of endogenously induced IL‐1α in pIgR mRNA upregulation by using IL‐1α knockout (KO) mice. Contrary to our expectations, pIgR mRNA expression was equally upregulated by BB6378 in colonic explants from BALB/c and IL‐1α KO mice. Conversely, we examined the involvement of Toll‐like receptors in pIgR mRNA upregulation by using MyD88 KO mice. The upregulation of pIgR was completely suppressed in the explants derived from MyD88 KO mice. Taken together, we conclude that in a mouse intestinal explant model, the heat‐inactivated potential probiotic BB6378 increases intestinal pIgR expression in a site‐specific manner and that the upregulation of pIgR could be explained by a direct microbial effect on the epithelium via Toll‐like receptors.     

Effects of epithelial growth factor receptor (EGFR) kinase inhibitors on genetically reconstituted mouse mammary glands

The aim of the study was to determine the effects of a specific epithelial growth factor Receptor kinase inhibitor (EGFR-KI) and Taxol on tumor growth in a novel tumor model. MATERIAL & METHODS: A genetically engineered tumor model which uses "transgenic" organs in immune competent mice was used. NeuT-transfected immortalized HC11 epithelial cells and primary mouse mammary epithelial cells have been transplanted into the gland-free mammary fat pad of female BALB/c mice. Mammary tumors developed after a latency period of three to four weeks. The mice were thereafter daily orally treated over a 19 or 22-day period with 0, 38, 75, 2 x 75 mg/kg body weight (b.w.) EGFR-KI (n: 7-9 per group) or intravenously with 10 mg/kg b.w. Taxol. After necropsy the histopathological evaluation of the tumors was performed in a coded manner. The proliferation activity of tumor cells was analyzed by laser scanning cytometry (LSC) using anti-Ki67-antibodies. RESULTS: Oral Treatment with EGFR-KI in this transgenic organ model showed clear antitumor efficacy in a dose-dependent manner in the range between 38 and 75 mg/kg b.w. This antiproliferative effect appears to be minimally increased at 75 mg/kg/day twice per day. For all treatments a strong correlation between the biological behavior of the tumor, histopathology and cell proliferation could be established. In contrast, treatment with Taxol showed no significant reduction of tumor growth or cell proliferation in this model. This new transgenic organ model comprising histopathological evaluation and cell proliferation analysis appears to be a suitable test system for drug candidates that affect specific biochemical pathways. It may have greater predictive nature for clinical effects in humans as compared to conventional tumor models because of its c-erb B2 gene overexpression.     

Characterisation of matrix metalloproteinases and the effects of a broad-spectrum inhibitor (BB-1101) in peripheral nerve regeneration

The effect of treatment with a broad-spectrum inhibitor (BB1101) of the matrix metalloproteinases (MMPs) on nerve regeneration and functional recovery after nerve crush was examined. Drug treatment had no effect on latency but from 63 days the compound muscle action potential was significantly increased and was no different to that in the sham-operated controls at 72 days. Levels of MMP mRNA expression, and the localisation and activity of MMP proteins, were examined in rats for a 2 month period following a nerve crush injury, and compared with sham-operated controls. The mRNA of all the MMPs studied was up-regulated by 5-10 days after nerve crush, and they remained up-regulated for 40-63 days, except for MMP-9 which was down-regulated by 10 days. MMP immunoreactivity was localised to Schwann cells, macrophages and endothelial cells, and with the exception of membrane type 1-MMP (MT1-MMP), it was more intense after nerve crush compared with sham-operated controls. Regenerating axons showed immunoreactivity for MMP-2 and MMP-3. In situ zymography confirmed that the activity of MMPs in the nerve was increased following crush but that the activity was greatly reduced in rats treated with BB-1101. Thus despite the inhibition of MMPs by BB-1101, the drug did not appear to essentially affect nerve degeneration or regeneration following nerve crush but that it could be beneficial in promoting the more effective reinnervation of muscles possibly by actions at the level of the muscles.     

Changes in hepatic superoxide dismutase and xanthine oxidase activity in mice infected with Salmonella typhimurium and Pseudomonas aeruginosa

Liver xanthine oxidase (XOD) and superoxide dismutase (SOD) activities were compared in mice during Salmonella typhimurium and Pseudomonas aeruginosa infections. We observed that XOD activity rose but SOD activity fell for the first 11 days after infection with smooth type S. typhimurium, coinciding with the period of bacterial growth in the liver. Rough type S. typhimurium did not establish an infection and mice inoculated with this strain showed no variation in enzyme activities. P. aeruginosa infection was mild but stimulated both XOD and SOD activities.