国外求购信息

国外求购信息１．法国求购消毒剂ＤＩＳＩＮＦＥＣＩ－ＡＮＩ－ＳＦＯＲＭＥＤＩＣＡＬ＆ＣＯＳＭＥＩ－ＩＥＣＳＦＩＥＬＤ，ＤＩＳＩＮＦＥＣＩ’ＡＮＴＳＦＯＲＦＯＯＤＩＮＤＵＳＴＲＹＭＲ．ＧＡＵＴＨＩＥＲ　ＰＬＯＵＶＩＥＲ　ＣＯＭＥＦＩ４０ＲＵＥＥＵＧＥＮＥ...     

库尔特MD10血球计数仪改MD18的方法

１软件库尔特ＭＤ１０（Ｅ版本）在一张高密小盘上载有：（１）ＤＯＳ５．０系统文件５个：ＩＯ．ＳＹＳ、ＭＳ－ＤＯＳ．ＳＹＳ、ＣＯＭＭＡＮＤ．ＣＯＭ、ＨＩＭＥＭ．ＳＹＳ、ＲＡＭ－ＤＲＩＶＥＲ·ＳＹＳ。其中前三个文件是ＤＯＳ的核心，完成操作系统的基本功能；ＨＩＭＥＭ．ＳＹＳ可以提供上位内存，ＲＡＭＤＲＩＶＥＲ．ＳＹＳ可用建立一个虚拟盘。（２）系统配置、自动批处理文件各１个：ＣＯＮ－ＦＩＧ．ＳＹＳ、ＡＵＴＯＥＸＥＣ．ＢＡＴ。前者为程序的运行提供运行环境，包括用ＨＩＭＥＭ．ＳＹＳ开辟上位内存和用ＲＡＭＤＲＩ…     

IQ CT阴极输出模块故障维修实例

故障现象机架工作正常,控制台高压ＲＥＡＤＹ灯不能点亮,即高压不能上电。打开机架,在高压控制及输出部分分别发现模拟控制板（ＡＮＡＬＯＧＹＣＯＮＴＲＯＬＬＢＯＡＲＤ）的ＤＳ７灯点亮,提示板上 １５Ｖ控制电源（ １５ＶＳＷＩＴＣＨ）故障;在阴极输出模块（ＣＡＴＨＯＤＯＵＴＰＵＴＭＯＤＵＬＥ）上ＤＳ９灯亮,提示模块 １５Ｖ控制电源（ １５ＶＳＷＩＴＣＨ）故障;在逆变诊断控制板（ＩＮＶＥＲＴＥＲＤＩＡＧＮＯＳＴＩＣＢＯＡＲＤ）上的ＤＳ１５灯点亮,提示板上 １５Ｖ控制电源（ １５ＶＳＷＩＴＣＨ）故障;在系统控制板（ＳＹＳ…     

缺锌对大鼠脂质过氧化及抗氧化系统的影响

研究缺锌对３周龄大鼠的脂质过氧化和抗氧化系统的影响。方法：健康Ｗｉｓｔａｒ大鼠３３只,雌雄各半,按体重随机分为Ａ（缺锌组）,Ｂ（自由进食对照组）,Ｃ（配对喂养组）。每组１１只,实验期４０天。观察指标有血清和肝脏锌,肝脏超氧化物歧化酶（ＳＯＤ）、谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）活性,血清和肝脏丙二醛（ＭＤＡ）,并采用电子自旋共振（ｅｌｅｃｔｒｏｎｓｐｉｎｒｅｓｏｎａｎｃｅ,ＥＳＲ）及自旋捕捉技术直接测定大鼠肝组织中的氧自由基。结果：Ａ组大鼠肝脏ＳＯＤ、ＧＳＨ－Ｐｘ活性明显下降,血清和肝脏ＭＤＡ含量显著升高,ＥＳＲ图谱出现了Ｎ－Ｈ偶合的三组双峰波。结论：缺锌可以使大鼠脂质过氧化反应明显加强,而抗氧化能力明显减弱。     

抗氧化剂对黄曲霉毒素染毒的转基因小鼠肝肿瘤的防护

目的研究抗氧化剂２,３叔丁基４羟基茴香醚（ＢＨＡ）对黄曲霉毒素（ＡＦＢ１）染毒的乙型肝炎病毒（ＨＢＶ）转基因小鼠肝肿瘤发生的防护作用。方法对ＡＦＢ１染毒和未染毒的４９只转基因小鼠与４８只非转基因小鼠,测定肝醌还原酶（ＱＲ）和谷胱甘肽Ｓ转移酶（ＧＳＴ）活性、肝丙二醛（ＭＤＡ）含量、肝氧自由基浓度（ＯＦＲ）。结果染毒的转基因小鼠ＢＨＡ组肝腺瘤发生率１７％,癌变率０,显著低于普通饲料组的肝腺瘤发生率（６７％）和癌变率（２２％）。与普通饲料组比较,ＢＨＡ使肝ＯＦＲ和ＭＤＡ含量显著降低;ＢＨＡ组肝ＱＲ和ＧＳＴ活性平均升高３～７倍。结论ＢＨＡ能显著诱导肝脏生物转化Ⅱ相酶活性,清除氧自由基,抑制变异肝细胞生长,可能与抑制或延缓小鼠肝癌的发生、发展进程有关     

β-胡萝卜素和核黄素对大鼠脂质过氧化的影响

目的：进一步探讨亚硝胺通过脂质过氧化而致癌的可能途径,以及研究β－胡萝卜素（β－Ｃ）和核黄素（ＶＢ２）通过抑制脂质过氧化反应而影响亚硝胺致癌的可能途径。方法：将５０只二级ＳＤ雄性大鼠随机分成５组。实验组在每日灌胃二甲基亚硝胺（ＮＤＭＮ）１．７５ｍｇ／ｋｇ的基础上,每日分别给予β－Ｃ２５ｍｇ／ｋｇ和／或ＶＢ２１８ｍｇ／ｋｇ补充,实验期为２８天。实验结束时,收集血液,摘取肝脏和肾脏,测红细胞和肝肾匀浆ＳＯＤ活性,全血ＧＳＨ－Ｐｘ活性,血清和肝肾匀浆ＭＤＡ含量,血清ＲＯＯＨ以及全血Ｈｂ含量。结果：１．ＮＤＭＮ可使ＳＯＤ和ＧＳＨ－Ｐｘ活性下降（Ｐ＜０．０５）,ＭＤＡ和ＲＯＯＨ产生增多（Ｐ＜０．０５）。２．添加β－Ｃ后,ＳＯＤ和ＧＳＨ－Ｐｘ活性有明显提高（Ｐ＜０．０５）,ＭＤＡ和ＲＯＯＨ的含量明显降低（Ｐ＜０．０５）。３．添加ＶＢ２后,肝ＳＯＤ和全血ＧＳＨ－Ｐｘ活性均有明显提高（Ｐ＜０．０５）,但ＭＤＡ和ＲＯＯＨ的含量没有差异（Ｐ＞０．０５）。４．同时补充β－Ｃ和ＶＢ２后,各项指标的变化与单纯β－Ｃ组基本一致。结论：脂质过氧化也是亚硝胺致癌的途径之一;一定剂量的β－Ｃ可对抗ＮＤＭＮ引发的脂质过氧化;核黄素对提高抗氧化?     

DX数字减影DGTEST程序的应用

ＤＧＴＥＳＴ是一种用于诊断美国ＧＥ公司数字减影ＤＸＨＩＬＩＮＥＶＤＰ（视频数字处理）硬件系统的检测程序,由ＰＡＳＣＡＬ语言写成,其主要性能有：１．在ＤＸ系统控制台或遥控台上独立对ＶＤＰ进行硬件测试;２．提供故障诊断在线帮助;３．ＶＤＰ硬件软件仿真等命令工具要运行ＤＧＴＥＳＴ程序,必须预先在ＤＸＨＩ－ＬＩＮＥ系统的软驱里安放一张引导磁盘,在ＶＥＲ－ＳＡＤＯＳ操作系统下“＝”产生后键入ＤＧＴＥＳＴ且回车,ＤＸ系统控制台对话监视器上就显示出如下的诊断主菜单：ＭＡＩＮＴＥＳＴＭＥＮＵ１—ＤＩＡＧＮＯＳＴ…     

谷胱甘肽转硫酶M1,T1基因型与胃癌易感性的关系

目的　探讨谷胱甘肽转硫酶Ｍ１（ＧＳＴＭ１）、Ｔ１（ＧＳＴＴ１）基因型与胃癌危险性的关系。方法　采用病例对照分子流行病学研究方法和聚合酶链反应技术, 检测９５ 例原发性胃癌病例和９４ 例对照者ＧＳＴＭ１ 和ＧＳＴＴ１ 基因型。结果　ＧＳＴＭ１ 基因缺失［ＧＳＴＭ１（－ ）］ 频率在病例组和对照组分别是６３－１６％ 和４５．７４％ ,差异有显著性（χ２ ＝５ ．７５,Ｐ＝ ０．０１６ ５） ,ＧＳＴＭ１ 基因缺失与胃癌易感性有关（ＯＲ＝ ２．０３,９５％ 可信区间＝１．０９～３．８０ ）。携带ＧＳＴＭ１（ －） 和ＧＳＴＴ１（＋ ）基因型者发生胃癌的危险性显著高于ＧＳＴＭ１（ ＋） 和ＧＳＴＴ１（ －） 基因型携带者,比值比ＯＲ＝２．９１,９５％ 可信区间＝１．０９～７．８９。ＧＳＴＭ１ 基因缺失同时暴露于吸烟者患胃癌的危险性显著增高（ ＯＲ＝ ８．０６ ,９５％ 可信区间＝ ２．８３ ～２３．６７） 。结论　ＧＳＴＭ１ 基因缺失型可增加胃癌发生的危险性。     

苦荞蛋白复合物的营养成分及其抗衰老作用的研究

分析苦荞蛋白复合物的营养成分,观察其抗衰老效果。方法：用碱抽提和等电点沉淀法从苦荞麦籽粒中制备出苦荞蛋白复合物（ＴＢＰＣ）,再用含２０％ＴＢＰＣ饲料喂小鼠,观察对小鼠血液和脏器中超氧化物岐化酶（ＳＯＤ）、过氧化氢酶（ＣＡＴ）和谷胱苷肽过氧化物酶（ＧＳＨ－Ｐｘ）的活性的影响。结果：ＴＢＰＣ的蛋白质含量为６３．４％,脂肪１２．７％,碳水化物１０．２％,灰分３．５％,粗纤维０．４％,水分９．８％。用ＴＢＰＣ饲喂后,小鼠血液、肝脏和心脏中ＳＯＤ、ＣＡＴ和ＧＳＨ－Ｐｘ活性均有不同程度提高,脂质过氧化产物丙二醛（ＭＤＡ）含量下降。结论：苦荞蛋白复合物对生物体有一定营养和抗衰老作用。     

卫生防疫计算机网络初探

经过技术调研、方案论证、网络实施和调试运行等阶段工作,深圳市罗湖区卫生防疫站计算机网络系统（ＳＨＥＮＺＨＥＮＬＵＯＨＵＰＵＢＬＩＣＨＥＡＬＴＨＡＮＤＡＮＴＩ－ＥＰＩＤＥＭＩＣＳＩＮＦＯＲＭＡＴＩＯＮＮＥＴＷＯＲＫＳＹＳＴＥＭ,ＳＺＬＨＰＨＮＥＴ）已如...     

温石棉对A549细胞细胞色素P4501A1和谷胱甘肽S转移酶活性的影响

目的：探讨温石棉对体外培养细胞中外源性化合物代谢酶活性的影响。方法：采用不同剂量的UICC温石棉（UC）和国产茫崖温石棉（MC）分别作用于A549细胞,测A549细胞中细胞色素P4501A1（CYPA1）和谷胱甘肽S转移酶（GST）活性,并用苯并（a)芘对酶活性进行诱导,再测定温石棉对2种酶诱导活性的影响。结果：UC与A549细胞作用24h,乙氧基异酚恶唑－O－去乙基酶（EROD）活性随剂量增加呈缓慢递趋势,200mg/L UC可使EROD活性升高40％,但200mg/L UC作用48h则使其活性下降32％,提示UC对A549细胞EROD活性的影响呈现低剂量短时间诱导,而高剂量长时间抑制的趋势,MC对EROD活性的影响呈现多向性,无论作用24h还是48h,25mg/L UC作用48h则使其活性下降32％,提示UC对A549细胞EROD活性的影响呈现低剂量短时间诱导,而高剂量长时间抑制的趋势,MC对EROD活性的影响呈现多向性,无论作用24h还是48h,25mg/L的MC诱导作用最强（分别为对照组的1．86和1．28倍）,但随MC剂量增大和作用时间延长,EROD活性也随之下降,最低仅为对照组的35％,UC作用对GST的影响不明显,最高仅使GST活性升高20％,MC在25mg/L时驿GST的诱导最强,为对照组的1．4倍,但随着剂量的增加,对GST活性的上诱导转为抑制,200mg/L时GST活性下降了18．7％,先用温石棉与A549细胞作用24h,再加入苯并(a)芘对酶活性进行诱导,发现无论是UC还是MC,均未对苯并(a)芘诱导的EROD活性产生明显影响。但200mg/L的UC和100mg/L的MC均可增加GST的诱导活性。结论：不同剂量温石析对EROD和GST活性表现出不同的效应,其原因可能与2种温石棉的物理化学特性及表面活性有关。     

Effects of hepatotoxicants on the induction of microsomal monooxygenase activity in sunfish liver by beta-naphthoflavone and benzo[a]pyrene.

Effects of chemically induced hepatic injury on biotransformation enzymes in fish were studied. Sunfish hybrids (Lepomis macrochirus x L. cyanellus) were dosed per os with allyl formate (ALF) and carbon tetrachloride (CCl4), and the induction of liver EROD (7-ethoxyresorufin O-deethylase) activity was subsequently challenged by injections of beta-naphthoflavone (BNF) and benzo[a]pyrene (B[a]P). Hepatotoxicity of chemical treatments was assessed using blood enzymes (ASAT, ALAT, and LDH) along with other biochemical variables. Both hepatotoxicants partially abolished the induction of EROD (maximally by 76-89%), and the decrease in induction was dose related. The cytosolic activity of glutathione S-transferase (GST) in the liver decreased in parallel with the decrease in EROD induction. Fish receiving high doses of ALF exhibited significantly less microsomal and blood plasma proteins and, occasionally, were jaundiced. These symptoms, however, were less sensitive indicators of hepatotoxicity than alterations in liver EROD and GST. Both ALF and CCl4 increased the activities of hepatic enzymes in the blood plasma, indicating cytotoxicity. In addition B[a]P, unlike BNF, also increased plasma activities of LDH and ALAT at a dose inducing liver EROD, implying simultaneous hepatotoxicity at high sublethal levels of this xenobiotic. These data suggest that hepatotoxic chemicals absorbed by fish may act antagonistically by decreasing the degree of induction of the cytochrome P450 system relative to the inherent capacity of inducing xenobiotic chemicals present in the environment. Therefore, when assessing the toxicological status of water using fish health biomarkers, it is advisable to measure a concert of metabolic and biochemical variables instead of any single biomarker.     

The changes of serum testosterone level and hepatic microsome enzyme activity of crucian carp (Carassius carassius) exposed to a sublethal dosage of pentachlorophenol

Pentachlorophenol (PCP), which was reported to be a typical persistent organic pollutant and environmental endocrine disruptor, may cause threat to aquatic species. In this study, serum testosterone concentration, activity of liver microsome ethoxyresorufin O-deethylase (EROD) and glutathione S-transferases (GST) of crucian carp (Carassius carassius) exposed to PCP for 7 and 15 d, respectively, were examined. The results showed that testosterone concentration was induced remarkably after 7 d (P<0.05), and the testosterone concentrations in 15 d treatment crucian carp were higher than those in 7 d treatment. It was found that there were significant effects on activities of EROD and GST after crucian carp were exposed to PCP for 7 and 15 d (P<0.05), compared to the controls. EROD and GST activities increased with increase in PCP concentration and also with increase in time on exposure. The results indicated that serum testosterone, EROD and GST were sensitive endpoints to PCP. PCP may have endocrine disrupting activities and may affect the reproductive success of this species. It is possible that the changes of hepatic microsome enzyme activities may result in alterations of serum testosterone levels in crucian carp.     

拟除虫菊酯对大鼠脑组织γ-氨基丁酸转氨酶活力的影响

目的　研究拟除虫菊酯对大鼠脑组织γ 氨基丁酸转氨酶 (GABAT)活力的影响。方法　应用偶联酶学紫外分光光度法 ,在体外和整体实验中 ,观察溴氰菊酯 (DM)和氯菊酯 (PM)对大鼠大脑皮层、海马、纹状体和小脑GABAT活力的影响。结果　在体外 ,终浓度为 10 -9～ 10 -4mol/L的DM或PM对大鼠大脑皮层、海马、纹状体和小脑的GABAT活力无明显影响 ;一次性经口给予 37.5mg/kg的DM组大鼠大脑皮层、海马和小脑的GABAT活力分别为 (2 .96± 0 .4 3)、(2 .13± 0 .4 4 )、(5 .12± 1.36 )nmol·mgpro-1·min-1,低于对照组 [(3.4 3± 0 .4 1)、(2 .6 8± 0 .4 7)、(6 .74± 1.6 4 )nmol·mgpro-1·min-1],差异有显著性 (P <0 .0 5 ) ,6 0 0mg/kgPM一次性染毒组大鼠大脑皮层和海马的GABAT活力分别为(4.5 7± 0 .30 )、(4.18± 0 .6 3)nmol·mgpro-1·min-1,高于对照组 ,差异有显著性 (P <0 .0 5 ) ;连续 5d每天 1次经口给予 12 .5mg/kg的DM或 2 0 0mg/kg的PM ,均对大鼠大脑皮层、海马、纹状体和小脑的GABAT活力无明显影响。结论　在体外 ,DM和PM均对大鼠脑组织GABAT活力无明显影响 ;在整体实验中 ,DM和PM对大鼠脑组织GABAT活力的影响可能存在差异。     

Interactions of 2,4,6-trinitrotoluene (TNT) with xenobiotic biotransformation system in European eel Anguilla anguilla (Linnaeus, 1758)

The aim of the present study was to investigate the interaction of 2,4,6-trinitrotoluene (TNT) with liver biotransformation enzymes in European eel Anguilla anguilla (Linnaeus, 1758). Eels were exposed to 0.5, 1 and 2.5 mg/l nominal concentrations of TNT for 6 and 24 h. Modulation of CYP1A1, UDPGT and GST genes was investigated by real-time PCR. Total CYP450 content, NADPH cytochrome c reductase activity, CYP1A and CYP2B-like activities, such as EROD, MROD and BROD, as well as GST and UDPGT activities, were measured by biochemical assays. An in vitro study was performed on EROD in order to evaluate catalytic modulation by TNT. No modulation of the CYP1A1 gene or protein was observed in TNT-exposed eels. On the other hand, a significant decline of EROD and MROD activities was observed in vivo. An increase in NADPH cyt c reductase, and phase II enzymes (UDPGT and GST) were observed at both gene expression and activity levels. The overall results indicated that TNT is a potential competitive inhibitor of CYP1A activities. A TNT metabolic pathway involving NADPH cyt c reductase and phase II enzymes is also suggested.     

Effects of metals and detergents on biotransformation and detoxification enzymes of leaping mullet (Liza saliens)

In this study, feral leaping mullet (Liza saliens) liver microsomal 7-ethoxyresorufin O-deethylase (EROD), and cytosolic glutathione S-transferases (GSTs) activities were investigated using 7-ethoxyresorufin, 1-chloro-2,4-dinitrobenzene (CDNB), and ethacrynic acid (EA) as substrates, respectively. The average EROD activity was found as 1139+/-175 pmol resorufin/min/mg protein. The average GST activities towards CDNB and EA were found as 1364+/-41 and 140+/-19 nmol/min/mg protein, respectively. We have, then, investigated the in vitro effects of some metals and detergents on CYP1A and GST activities in leaping mullet liver. Leaping mullet liver microsomal EROD activity was significantly inhibited by Hg (0.1 mM), Ni (0.1 mM), Cd (0.1 mM), Cu (0.1 mM), Zn (0.1 mM), Sb (0.1 mM), Fe2+ (1 mM), Co (1 mM), Al (1 mM), and Fe3+ (1 mM), with the percent inhibition of 80, 80, 77, 75, 70, 69, 56, 53, 46, and 44, respectively. Similarly, conjugation of CDNB catalyzed by GST was inhibited significantly to lesser extend by Hg (0.1mM), Sb (0.1 mM), Cd (0.1 mM), Cu (0.1 mM), Zn (0.1 mM), Fe3+ (1 mM), Co (1 mM), and Fe2+ (1 mM), with the percent inhibition of 70, 69, 65, 61, 54, 51, 47, and 43, respectively. The degrees of inhibition observed on GST catalyzed EA conjugation by Hg (0.1 mM), Cd (0.1 mM), Sb (0.1 mM), Cu (0.1 mM), and Zn (0.1 mM) were 86, 78, 69, 51, and 42, respectively. In addition to metals, the effect of various detergents on leaping mullet liver EROD, GST-CDNB, and GST-EA activities were studied. It was found that ionic detergents strongly inhibited the EROD activity, whereas much less inhibitions were observed with GST catalyzed activities. Therefore, the CYP1A inhibition potencies of metals and detergents suggest that their contribution to the overall CYP1A induction in polycyclic aromatic hydrocarbons contaminated environmental samples has to be taken into account for better interpretation of environmental studies.     

Bioavailability of PCBs to Male Laboratory Rats Maintained on Litters of Contaminated Soils: PCB Burden and Induction of Alkoxyresorufin O-Dealkylase Activities in Liver and Lung

Male rats from the Sprague-Dawley laboratory strain were maintained in the laboratory during 3 days and 1 night on litters containing a reference soil and different amounts of a soil, mainly polluted by PCBs (207 ppm expressed in Aroclor? 1254; SIII soil). Two categories of biomarkers of exposure were measured in both liver and lung of these rats: PCB burdens and activities of microsomal liver and lung cytochrome P450–dependent mono-oxygenases, namely ethoxy-, pentoxy-, and benzoxy-resorufin O-dealkylase activities (EROD, PROD, and BROD, respectively). PCB burdens in liver and lung of rats exposed to SIII soil were 1,845 and 241 ppb, respectively (expressed in Aroclor? 1254 equivalents). EROD, PROD, and BROD were significantly induced in the liver of rats exposed to SIII soil, while only EROD activity was induced in the lung. Induction of hepatic EROD activity was ∼3- to 5.4-fold; pulmonary EROD activity was induced by 9- to 12-fold. In the lung, PROD and BROD activities were inhibited. When rats were exposed to SIII soil diluted with various amounts of standard ISO soil, a nearly linear dose-response relationship was found between the level of PCBs in the litter and EROD activity in both liver and lung. A nonlinear dose-response relationship exists with hepatic BROD activity; no dose-response relationship was observed with hepatic PROD and pulmonary PROD and BROD activities. EROD activity measurement in both liver and lung of rats maintained on a litter of PCB polluted soil was used to assess the bioavailability to mammals of PCBs. Received: 16 December 1996/Accepted: 18 November 1997     

Oxidative stress responses in different organs of Jenynsia multidentata exposed to endosulfan

We evaluate antioxidant responses of Jenynsia multidentata experimentally exposed to sublethal concentrations of endosulfan (EDS). The main goal was to determine differences in the response between different organs to assess which one was more severely affected. Thus, we exposed females of J. multidentata to EDS during 24h, measuring the activity of GST, GR, GPx, CAT and LPO in brain, gills, liver, intestine and muscle of both exposed fish and controls. GST activity was inhibited in gills, liver, intestine and muscle of exposed fish but was induced in brain. GR and GPx activities were increased in brain and gills at 0.014 and 0.288 microg L(-1), respectively. GPx activity was inhibited in liver and muscle at all studied concentrations whereas inhibition was observed in the intestine above 0.288 microg L(-1). Exposure to 1.4 microg L(-1) EDS caused CAT inhibition and increase of LPO levels in liver. LPO was also increased in brain at almost all concentrations tested. We find that the brain was the most sensitive organ to oxidative damage. Thus, J. multidentata could be used as a suitable bioindicator of exposure to EDS measuring activities of antioxidant enzymes in brain and liver as biomarkers.     

Inhibitory effects of dietary caraway essential oils on 1,2-dimethylhydrazine-induced colon carcinogenesis is mediated by liver xenobiotic metabolizing enzymes

The effects of dietary essential oils prepared from caraway seeds on colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) in rats has been studied. The number of aberrant crypt foci (ACF) and aberrant crypt (AC) induced by DMH were found to be significantly inhibited in colon of rats treated with essential oils in diet (0.01 and 0.1%). To find out the mechanism(s) by which the essential oils reduced colon premalignancies, plasma, liver, and colon tissues were collected and analyzed for parameters related to oxidative stress and xenobiotic metabolizing enzymes. Lack of influence of caraway extracts on hepatic lipid peroxidation products, superoxide dismutase (SOD), catalase (CAT) and ferric reducing ability of plasma (FRAP) may suggest that the oils do not interfere with these factors. However, it was clearly shown that DMH-related changes in hepatic and colonic cytochrome P4501A1 (CYP1A1) and glutathione S-transferae (GST) activities were recovered in liver but not in colon tissue in animals treated with caraway oil preparations. In conclusion, histopathological and biochemical data clearly showed that inhibition of colon premalignant lesions induced by DMH is mediated by interference of caraway oil components in the activities of the main hepatic xenobiotic metabolizing enzymes.     

Organochlorines and Possible Biochemical Effects in Glaucous Gulls (Larus hyperboreus) from Bjørnøya, the Barents Sea

To study possible biochemical effects of organochlorine contaminants (OCs) in glaucous gulls (Larus hyperboreus), 40 adult individuals were collected from colonies on Bjornoya in the Barents Sea. OCs (four pesticides and nine PCB congeners), microsomal 7-ethoxyresorufin O-deethylase (EROD) activity, microsomal testosterone hydroxylation, highly carboxylated porphyrins (HCPs), retinol, and retinyl palmitate were quantified in liver samples. The hepatic vitamin A stores in glaucous gulls were larger than in herring gulls (Larus argentatus) from other studies conducted in contaminated locations in North America. No significant relationships were found between liver retinoid concentrations and OC levels. The hepatic EROD activity was low compared to other studies on fish-eating birds and only marginally associated with PCB levels. Microsomal testosterone hydroxylase activity was only observed at the 6beta-position and could not be related to OC levels. The low P450-associated enzyme activities in the glaucous gull suggests that they have a low capacity for metabolizing OCs, which may contribute to the high accumulation of OCs in this species. HCPs were only elevated (138 pmol g(-1)) in the sample with highest OC levels, whereas the remaining samples contained low levels of HCPs (<30 pmol g(-1)). The weak association between EROD activity and PCB levels and the low level of HCPs suggest that these biochemical parameters were unaffected by OCs in most of the sampled gulls. Thus, the glaucous gull seems not to be particularly sensitive toward Ah-receptor mediated effects.