缺锌对大鼠胸腺发育影响及机理探讨

目的：研究缺锌对胸腺发育及Ｔ淋巴细胞活化与增殖功能的影响。方法：建立大鼠缺锌（ＺＤ）模型，测定胸腺肽、胸腺激素活性、胸腺Ｔ淋巴细胞转化、活化Ｔ淋巴细胞钙离子和活性钙调蛋白等。结果：１．ＺＤ组的血清、毛、胸腺细胞锌含量低于对照（ＡＬ）组（Ｐ＜０．０１）。２．ＺＤ组的胸腺重量、指数和细胞大小低于ＡＬ组（Ｐ＜０．０１或Ｐ＜０．０５）。３．ＺＤ组胸腺的胸腺肽含量、胸腺素活性低于ＡＬ组（Ｐ＜０．０１）。４．ＺＤ组胸腺细胞的ＤＮＡ、ＲＮＡ和蛋白质含量低于ＡＬ组（Ｐ＜０．０１）。５．ＺＤ组胸腺细胞中增殖期细胞（Ｓ＋Ｇ２／Ｍ）、增殖指数（ＰＩ）低于ＡＬ组（Ｐ＜０．０１）。６．ＺＤ组胸腺细胞内ｃＡＭＰ含量与ｃＡＭＰ／ｃＧＭＰ比值高于ＡＬ组（Ｐ＜０．０１）。７．ＺＤ组胸腺细胞内的Ｃａ２＋、ＣａＭ、ＩＬ－２、ＩＬ－２Ｒα及Ｔ细胞增殖率低于ＡＬ组（Ｐ＜０．０１）。８．ＺＤ组胸腺Ｔ淋巴细胞内的锌离子与Ｃａ２＋、ＣａＭ、ＩＬ－２、ＩＬ－２Ｒα、Ｔ淋巴细胞增殖率呈正相关（Ｐ＜０．０１）；Ｃａ２＋与ＩＬ－２、ＩＬ－２Ｒα呈正相关（Ｐ＜０．０１）；ＣａＭ与ＩＬ－２、ＩＬ－２Ｒα呈正相关（Ｐ＜０．０１）。结论：适量锌有促进胸腺发育、胸腺激素活?     

高锌饲料对大鼠胸腺发育及其作用机理的探讨

通过建立大鼠高锌（ＺＨ）模型，研究高锌对胸腺发育的影响及其作用机理。结果表明：（１）ＺＨ组的体重、体重增长值、饲料效价均非常显著低于配对（ＰＦ）组；（２）ＺＨ组的血清、毛发、股骨及胸腺细胞锌含量均非常显著地高于ＰＦ组；（３）ＺＨ组的胸腺重量、胸腺指数、胸腺细胞大小、胸腺肽含量和胸腺素活性，均非常显著地低于ＰＦ组；（４）ＺＨ组的胸腺细胞内ＤＮＡ、蛋白质含量低于，而Ｇ１／Ｇ０期细胞（％）数高于ＰＦ组；（５）ＺＨ组胸腺细胞内ｃＡＭＰ、ｃＡＭＰ／ｃＧＭＰ比值非常显著高于ＰＦ组，增殖指数（ＰＩ）与ｃＡＭＰ、ｃＡＭＰ／ｃＧＭＰ比值呈负相关；与ｃＧＭＰ呈正相关，均Ｐ＜０．０１；（６）ＺＨ组血清钙低于ＰＦ组，而胸腺细胞内Ｃａ２＋高于ＰＦ组，Ｐ＜０．０５。结果提示，适量锌有促进胸腺发育、增殖的作用，而高锌则反之。其机理可能是高锌影响细胞内腺苷酸环化酶系统，并与胞浆内游离钙和钙调蛋白的调节活性有关。     

急性髓系白血病细胞自分泌GM-CSF及其凋亡的研究

要探讨急性髓系白血病（ＡＭＬ）原代细胞自分泌的粒细胞－巨噬细胞集落刺激因子（ＧＭ－ＣＳＦ）和重组人粒细胞－巨噬细胞集落刺激因子（ｒｈＧＭ－ＣＳＦ）对原代ＡＭＬ细胞凋亡的影响,应用放射免疫技术检测ＧＭ－ＣＳＦ水平,ＤＮＡ电泳检查梯状条带及流式细胞仪检测细胞凋亡率和ＢｃＩ－２蛋白表达的阳性细胞率和相对荧光强度（ＭＦＩ）。结果在５例原代ＡＭＬ细胞体外培养中,３例的培养上清液可检测到ＧＭ－ＣＳＦ,其自发细     

多环芳香烃空气浓度和焦碳炉工人多环芳香烃-DNA加合的相关性

多环芳香烃空气浓度和焦碳炉工人多环芳香烃－ＤＮＡ加合的相关性Ｇ．Ａｓｓｅｎｎａｔｏｅｔａｌ．不同多环芳香烃（ＰＡＨ）的加合物对人类可有相似的血清学改变，可形成免疫反应抗御单个的ＰＡＨ－ＤＮＡ加合物。据此理论，本研究用周围血液白细胞ＢＮＡ加合物作为ＰＡ...     

苯DNA加合物的组织分布及其与细胞遗传毒性的关系

用Ｐ１增强的３２Ｐ－后标记方法测定了经腹腔注射染苯小鼠不同组织ＤＮＡ加合物的分布及其与苯引起的外周血白细胞（ＷＢＣ）减少、淋巴细胞微核形成及骨髓细胞染色体畸变的关系。结果表明：１．苯在小鼠骨髓、肝脏和外周血ＷＢＣ均可形成ＤＮＡ加合物，其加合物含量以骨髓最高，肝脏次之，ＷＢＣ最低。本结果与苯的代谢及毒性作用特点相一致。２．ＤＮＡ加合物形成与细胞毒性有关系，ＤＮＡ加合物量增加，淋巴细胞微核及骨髓细胞染色体畸变亦增加，而外周血白细胞数明显减少，显示细胞遗传毒性和细胞毒性均增大。本研究为ＤＮＡ加合物作为生物学监测指标，筛选高危人群提供了有力的实验依据。     

UV－DNA和抗UV－DNA血清的研制及初步应用

本文用短波紫外线（ＵＶＣ）照射人胎盘和小牛胸腺ＤＮＡ取得ＵＶ－ＤＮＡ（紫外线导致变性的ＤＮＡ），并分别对新西兰家兔进行长达９周的免疫。结果表明：人胎盘ＵＶ－ＤＮＡ未能引起免疫应答，其抗ＵＶ－ＤＮＡ未能检出。而小牛胸腺的抗ＵＶ－ＤＮＡ的效价为１：８。用兔抗小牛胸腺ＵＶ－ＤＮＡ检测３２例红斑狼疮（ＳＬＥ）病人和２１例正常人的血清，发现ＳＬＥ病人血清中ＵＶ－ＤＮＡ的阳性率为６５．６％，正常人为５％。两者的差异有非常显著性意义（Ｐ＜０．０１）。提示血清中ＵＶ－ＤＮＡ可望成为ＳＬＥ诊断和疗效观察及人群接触紫外线时健康监测的特异和敏感指标之一。     

维生素A对小鼠造血微环境影响的研究

目的：　探讨维生素Ａ（ＶＡ）对造血微环境的影响,揭示ＶＡ缺乏影响红系造血的机制。方法：免疫细胞化学（ＳＰ）法检测视黄酸受体（ＲＡＲａ）蛋白,原位杂交技术动态检测原癌基因ｃ－ｊｕｎ、ｃ－ｆｏｓ和粒－单集落刺激因子（ＧＭ－ＣＳＦ）ｍ ＲＮＡ 的表达,检测细胞因子生物活性和基质细胞层粘附能力。结果：　（１）全反式视黄酸（ＡＴＲＡ）诱导的小鼠骨髓基质细胞条件培养液（ＢＭＳＣＣＭ）能显著促进红系早期祖细胞（ＢＦＵ－Ｅ）的增殖（Ｐ＜ ０．０１）。（２）ＡＴＲＡ明显促进基质细胞层的粘附能力。（３）ＲＡＲａ 蛋白在实验组和对照组ＢＭＳＣ持续表达,ＡＴＲＡ对其表达水平无影响。（４）实验组ＢＭＳＣ与对照组相比ｃ－ｆｏｓ、ｃ－ｊｕｎ ｍ ＲＮＡ的表达水平在３０ｍ ｉｎ 即有显著性差异（Ｐ＜ ０．０１）,持续表达至６０ｍ ｉｎ,１２０ｍ ｉｎ 降至对照组水平。实验组ＧＭ－ＣＳＦｍ ＲＮＡ的表达在３０ｍ ｉｎ,６０ｍ ｉｎ 与对照组水平相比无显著性差别,直至１２０ｍ ｉｎ 才表现出显著性差异（Ｐ＜ ０．０１）。结论：　ＶＡ促进小鼠ＢＭＳＣ分泌造血细胞生长因子并增强其粘附能力,通过调节ＢＭＳＣ中ｃ－ｊｕｎ、ｃ－ｆｏｓ的信号传导通路调节ＢＭＳＣ分泌ＧＭ－Ｃ     

接触室内煤烟的肺癌患者多环芳烃DNA加合物的研究

本实验是为了探索宣威肺癌病因和肺癌早期危险性评价方法做一点尝试，应用３２Ｐ后标记法检测了宣威３０例（实验组）、昆明１０例（对照组）肺癌病人的纤维支气管镜（纤支镜）刷落细胞的多环芳烃（ＰＡＨ）－ＤＮＡ加合物。结果表明宣威肺癌病人的ＰＡＨ－ＤＮＡ加合物水平远远高于对照组。该结果从分子水平上证明宣威室内煤烟污染与肺癌有直接联系，ＤＮＡ加合物的检测可以作为人群危险性评价的指标。     

3种醛类化合物对DNA的交联生成作用

采用溴化乙锭荧光法测定３种醛类污染物对小牛胸腺ＤＮＡ的交联生成作用,结果,甲醛、乙醛均可引起小牛胸腺ＤＮＡ发生交联,甲醛交联率间存在明显的剂量反应关系（甲醛ｒ＝０９３８４,Ｐ＜０００１）,乙醛的剂量反应关系不显著（ｒ＝０２９４７,Ｐ＜００５）,没有检测到丙烯醛对小牛胸腺ＤＮＡ的交联作用,分析与丙烯醛的空间位阻最大可能存在一定关系     

高频作业人员脂质过氧化和免疫功能的改变

观察高频（频率２００￣１０００ｋＨｚ）作业人员６２名血中ＬＰＯ、ＧＳＨ－Ｐｘ、ＳＯＤ、ＣＰ、ＩｇＡ、ＩｇＧ、ＩｇＭ、ｃＧＭＰ、ｃＡＭＰ的变化，探讨慢性低强度高频辐射对作业人员脂质过氧化和免疫功能的影响机制。结果表明：高频作业人员血中ＬＰＯ、ＧＳＨ－Ｐｘ与对照组差异显著，ｃＧＭＰ、ｃＡＭＰ和ＩｇＡ、ＩｇＧ、ＩｇＭ显著高于对照组；ＳＯＤ和ＣＰ的改变无统计学意义；高频淬火机的危害较大。     

苯醌-脱氧鸟苷酸加合物的结构及化学特性初步研究

目的 测定苯醌(BQ)与脱氧鸟苷酸(dGMP)反应形成的加合物结构与化学特性。方法 高效液相色谱—质谱联机技术及紫外分光光度法。结果 苯醌与脱氧鸟苷酸反应形成两种可检测的加台物Ad1和Ad2，质谱显示Ad1的分子量为437，在不同pH条件下的特征紫外吸收光谱及结合键类型测定结果表明，Ad1为BQ与dGMP共价结合而成，推测结合位点在dGMP的N—1和N^2位，分子式为C16H16O8N5P。BQ与小牛胸腺DNA反应水解产物经高效液相色谱(HPLC)分离同样检出了与Ad1具有相同保留时间的化合物。Ad2分子量为241，其分子式为C11H702N5，可能是由BQ进攻dGMP的N—9位并脱掉糖基所得。结论 苯醌可在体外试管反应条件下形成DNA加合物，其中一种主要的加合物结构为(3’-经基)—1，N^2—苯乙烯基—2’—脱氧鸟苷—5’—磷酸。     

Dietary nucleotides and human immune cells. II. Modulation of PBMC growth and cytokine secretion

OBJECTIVE: The immune system is dependent on purines and pyrimidines as building blocks for DNA and RNA synthesis to enable rapid cell proliferation and protein synthesis. Emerging evidence suggests that dietary nucleotides optimize immune function. We investigated whether growth and function of human immune cells were affected by an exogenous source of nucleotides during specific antigen challenge. METHODS: Peripheral blood mononuclear cells from healthy individuals (n = 10) were stimulated with influenza virus antigen and either DNA sodium from fish soft roe (DNA), RNA from bakers yeast (Saccharomyces cerevisiae) (RNA), 2' deoxyadenosine 5'-monophosphate sodium (dAMP), 2' deoxycytidine 5'-monophosphate sodium (dCMP), 2' deoxyguanosine 5'-monophosphate sodium (dGMP), 2' deoxyuridine 5'-monophosphate sodium (dUMP) or thymidine sodium (TMP). Growth effects were ascertained by measuring the amount of tritium-labeled thymidine, incorporated into cell DNA. Cell function was measured by detection of IFN-gamma, TNF-alpha and IL-10 production. RESULTS: Specific nucleotide derivatives alone did not affect the growth of healthy peripheral blood mononuclear cells. However, the nucleotide derivatives influenced immune cell growth and cytokine secretion when cocultured with specific antigen. DNA, RNA, dAMP, dCMP and dUMP increased influenza virus antigen induced immune cell proliferation. In contrast dGMP and TMP inhibited the antigen-induced growth response. RNA and dAMP cocultured with virus antigen significantly increased peripheral blood mononuclear cell secretion of IFN-gamma, IL-10 and TNF-alpha. DNA increased virus antigen-induced immune cell secretion of IFN-gamma only, whereas dUMP significantly increased secretion of IL-10 only. dGMP completely inhibited virus-triggered IFN-gamma secretion, whereas TMP did not change the virus induced secretion pattern of measured cytokines. CONCLUSION: Nucleotide derivatives affect growth and function of specific virus antigen-stimulated human immune cells in vitro.     

HPLC法研究苯乙烯-DNA的加合特性

目的：研究苯乙烯的DNA加合特性。方法：采用高效液相色谱法研究苯乙烯-7，8-氧化物（S0）、苯乙烯、苯乙醇酸（MA）、苯乙醛酸（PGA）和DNA的加合反应。结果：苯乙烯、MA、PGA不与DNA发生加合反应；SO可与脱氧鸟苷酸及脱氧腺苷酸发生加合反应，生成以共价键结合的加合物。结论：苯乙烯进入机体后，通过其活性中间代谢物SO与DNA起加合作用，SO攻击DNA脱氧鸟苷酸及脱氧腺苷酸形成加合物，如果在细胞复制前所形成的DNA加合物没有被修复或者被错误修复的话，就有可能导致基因突变。苯乙烯的其他代谢物未见此效应。     

苯乙烯-DNA加合特性的研究

目的 研究苯乙烯的DNA加合特性。方法 采用紫外光谱移动法测定苯乙烯－7，8－氧化物（SO）、苯乙烯、苯乙醇酸（MA）、苯乙醛酸（PGA）、苯乙烯巯基尿酸（UMA）和DNA的加合反应；以^32P后标记法研究SO－DNA加合物；以气相色谱－质谱、核磁共振研究SO－DAN加合物的结构。结果 苯乙烯、MA、PGA和UMA不与DNA发生加合反应；SO分别在DNA脱氧鸟苷碱基上的O^6位、N^2位形成6种加合物。结论 苯乙烯进入机体后，通过其活性中间代谢物SO与DNA起加合作用，SO攻击DNA脱氧鸟苷碱基上的O^6位、N^2位形成加合物，如果在细胞复制前所形成的DNA加合物没有被修复或者被错误修复的话，就有可能导致基因突变，产生化学损伤。苯乙烯的其他代谢物未见此效应。     

三种醛类化合物-DNA加合特性的研究

目的 探讨甲醛、乙醛和丙烯醛对DNA的损伤机制.方法 采用体外测试系统,应用高效液相色谱法(HPLC)对甲醛、乙醛、丙烯醛及其在人体内的代谢产物甲酸、乙酸、羟丙基巯基尿酸与4种单脱氧核苷酸的加合反应进行研究.结果 经HPLC分离检测,甲醛、醋醛与脱氧鸟苷酸发生加合反应,而丙烯醛、甲酸、醋酸和羟丙基巯基尿酸难以与脱氧鸟苷酸发生加合反应或加合物产量过低,初步确定了甲醛、乙醛与4种单脱氧核苷酸结合的优势反应核苷酸.结论 甲醛、乙醛能够与DNA的脱氧鸟苷酸结合而体现遗传特性.     

Synthesis, characterization, antioxidant activity and DNA-binding studies of two rare earth(III) complexes with naringenin-2-hydroxy benzoyl hydrazone ligand

Two novel rare earth complexes, Y(III) complex (1) and Eu(III) complex (2), with naringenin-2-hydroxy benzoyl hydrazone ligand were synthesized and characterized. The interaction of the two metal complexes and the free ligand with calf thymus DNA (CT DNA) was investigated by electronic absorption spectroscopy, fluorescence spectroscopy and viscosity measurement. All the experimental evidences indicate that these three compounds can strongly bind to CT DNA via an intercalation mechanism. The intrinsic binding constants of the Y(III) complex (1), Eu(III) complex (2) and the free ligand with CT DNA were 2.1x10(4), 8.5x10(4) and 1.6x10(4)M(-1), respectively. Furthermore, the antioxidant activity of the metal complexes was determined by hydroxyl radical scavenging method in vitro.     

Metabolic activation of retronecine and retronecine N-oxide - formation of DHP-derived DNA adducts

We have previously reported that metabolism of a series of pyrrolizidine alkaloids in vitro and in vivo generated a set of (+/-)6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP)-derived DNA adducts. It has also been shown that the levels of the DHP-derived DNA adduct formation correlated closely with the tumorigenic potencies of the mice fed with different doses of riddelliine. Retronecine is the necine base and the structurally smallest chemical of the retronecine-type pyrrolizidine alkaloids. Although it has been reported that microsomal metabolism of retronecine generated DHP as a metabolite, it was yet not known whether metabolism of retronecine in vivo could generate DHP-derived DNA adducts and if formed, whether or not the levels of DNA adducts were comparable with those formed from the other tumorigenic retronecine-type pyrrolizidine alkaloids, such as riddelliine, retrorsine, and monocrotaline. In this investigation, the in-vitro and in-vivo metabolic activation of retronecine was studied. Rat liver microsomal metabolism of retronecine in the presence of calf thymus DNA resulted in the formation of a set of DHP-DNA adducts. The metabolism of retronecine N-oxide under similar conditions also formed the similar set of DHP-DNA adducts. The level of DNA adducts from retronecine was enhanced when metabolism by liver microsomes from phenobarbital (PB)-induced rats were used. The DHP-DNA adducts were also found in the liver DNA of female F344 rats treated with retronecine or retronecine N-oxide. The highest level of the total DHP-DNA adducts was found in liver DNA from the rats treated with dehydroretronecine (DHR). The order of the levels of DNA adducts in the liver DNA samples from rats treated with various pyrrolizidine alkaloids was: DHR > riddelliine > riddelliine N-oxide > retronecine > retronecine N-oxide. The results indicate that 1) retronecine can be metabolized to form DHP by rat liver microsomal enzymes and interacts with DNA to produce DHP-DNA adducts and 2) retronecine N-oxide undergoes the biotransformation to the parent compound, retronecine. The results from this and our previous findings strongly suggest that formation of DHP-DNA adducts may be a potential biomarker for pyrrolizidine alkaloid carcinogenesis.     

Fast repair activities towards dGMP hydroxyl radical adducts by silybin and its analogues

The repair activities of silybin (SLB) and its analogues towards the oxidizing deoxyguanosine monophosphate (dGMP) hydroxyl radical adducts are investigated by pulse radiolytic techniques. On pulse irradiation of nitrous oxide saturated 2.0 mM dGMP aqueous solution containing 0.1 mM silybin at neutral pH, the transient absorption spectrum of the dGMP hydroxyl radical adducts decreases with the formation of the phenoxyl radical of silybin within tens of microseconds, indicating that there is a repair reaction between the dGMP hydroxyl radical adduct and silybin. The rate constant of the repair reaction is calculated to be 1.0 x 10(9) M(-1)s(-1) for silybin. The repair activity of hesperetin (HESP), naringin (NAN) and naringenin (NAR) towards hydroxyl radical adducts of dGMP are also studied.     

丙烯腈对DNA交联作用研究

目的　应用牛胸腺DNA和染毒丙烯腈 (AN)小鼠精细胞研究AN对DNA的交联作用 ,研究AN毒作用的分子机制。方法　应用溴化乙锭荧光法测定加或不加S9条件下AN对牛胸腺DNA交联作用。雄性小鼠随机分为阴性对照 ,3、 6、 9、 12、 18和 2 4mg/kgAN染毒组 ,每组 2只。腹腔注射染毒 1次 ,于染毒第 2 4h处死小鼠 ,分离精细胞 ,观察细胞存活率 ,测定精细胞DNA交联率。结果　加与不加S9条件下 ,AN对牛胸腺DNA均未产生交联作用。小鼠精细胞DNA交联率在 3、 6、 9mg/kgAN剂量范围内随剂量增加而升高 ,呈明确的剂量 反应关系 (r =0 93 5 ,P <0 0 5 )。结论　在体外实验中AN对牛胸腺DNA未产生交联作用 ,对小鼠精细胞DNA在较低剂量时产生了交联作用 ,高剂量产生断裂作用和交联作用。AN对精细胞的DNA交联作用可能是产生生殖毒作用的分子机制之一     

lambda DNA-fragmenting actions of ascorbic acid and triose reductone in the presence of Cu2+

Lambda DNA-fragmenting actions of ascorbic acid (AsA) and triose reductone (TR) in the presence of Cu2+ were studied. The mixture of AsA or TR and Cu2+ caused a marked fragmentation of lambda DNA (3.2 X 10(7) daltons) within the first 1 min of reaction. Further incubation resulted in accumulation of the most abundant species of fragmented lambda DNA having a molecular weight of 1.3 X 10(5) daltons. The mixture of AsA or TR and Cu2+ fragmented calf thymus DNA to produce the fragmented DNA of which 5'-OH terminal groups have a mixture of free OH groups and phosphodiester linkage. The mixture of AsA or TR and Cu2+ was also found to fragment lambda DNA to produce dCMP predominantly as 5'-OH terminal nucleotides.