乙烯硫脲对FRTL-5细胞甲状腺球蛋白合成分泌及摄碘功能的影响

目的探讨乙烯硫脲(ETU)对FRTL-5细胞的甲状腺球蛋白(TG)合成分泌和摄碘能力的影响。方法用30、150和270μg/ml乙烯硫脲处理FRTL-5细胞后,用MTT法和3H掺入法测乙烯硫脲的细胞毒性;放免法和免疫细胞化学法测乙烯硫脲对TG合成分泌的影响;RT-PCR检测乙烯硫脲对nis基因和tg基因的影响;同位素示踪法检测对细胞摄碘能力的影响。结果30～270μg/ml乙烯硫脲对FRTL-5细胞无显著细胞毒性。150μg/ml和270μg/ml乙烯硫脲显著降低培养液中TG浓度,对胞浆内TG无显著影响;使nis基因转录显著降低,对tg基因无显著影响;150μg/ml和270μg/ml乙烯硫脲显著降低细胞摄碘能力。结论乙烯硫脲可抑制FRTL-5细胞分泌TG,对TG合成无显著影响;乙烯硫脲各剂量组显著降低nis基因转录,但仅在高剂量组显著降低细胞摄碘能力。     

磺胺二甲嘧啶对FRTL-5细胞合成、分泌甲状腺球蛋白的影响

[目的 ]研究磺胺二甲嘧啶对FRTL 5细胞株合成、分泌甲状腺球蛋白的影响 ,并探讨FRTL 5细胞株用于筛选环境甲状腺素干扰物的可能性。 [方法 ]FRTL 5细胞分别经 0 .5、1.0、2 .0、4.0、和 8.0 μg/ml磺胺二甲嘧啶染毒处理48h后 ,用MTT实验检测磺胺二甲嘧啶对细胞活力的影响以确定染毒浓度 ;以MTT实验最大无作用浓度作为最高染毒浓度 ,另设中、低浓度共 3组染毒细胞 ,用放射免疫法测定染毒 48h后培养液中细胞分泌甲状腺球蛋白的浓度 ;用活细胞爬片的免疫组化染色观察最高浓度处理组细胞胞质中合成甲状腺球蛋白的表达水平 ,并用透射电镜观察细胞的超微结构。[结果 ]根据MTT实验 ,确定染毒浓度为 0 .5、1.0和 2 .0 μg/ml,随磺胺二甲嘧啶浓度的增大 ,FRTL 5细胞培养液中甲状腺球蛋白的浓度逐渐降低 ,其中 1.0 μg/ml浓度组与对照组相比差异有统计学意义 (P <0 .0 5 ) ,2 .0 μg/ml浓度组培养液中未能检出甲状腺球蛋白 ;免疫组化染色可见染毒组细胞胞质中合成的甲状腺球蛋白表达显著减弱 ,图像分析结果显示其灰度值的差异有统计学意义 (P <0 .0 5 ) ;细胞超微结构观察发现染毒组细胞出现粗面内质网扩张。 [结论 ]通过损伤甲状腺滤泡细胞的粗面内质网 ,而影响甲状腺球蛋白的合成与分泌 ,这可能是磺胺二甲嘧啶干     

应用FRTL-5细胞探索五氯苯酚干扰甲状腺激素作用机制

目的利用FRTL-5细胞,在体外研究五氯苯酚干扰甲状腺激素活性的机制。方法设二甲亚砜溶剂对照组(DMSO);高氯酸钠摄碘阳性对照组;五氯苯酚:0.1μg/ml、0.3μg/ml和0.5μg/ml三个剂量组;五氯苯酚处理FRTL-5细胞24小时,用3H掺入法测其对FRTL-5细胞DNA合成的影响,放免法测其对培养液中甲状腺球蛋白浓度的影响;用五氯苯酚、高氯酸钠处理FRTL-5细胞12和24小时后,用同位素125I测摄碘能力的变化。结果3H掺入法显示五氯苯酚各剂量组对FRTL-5细胞DNA合成无显著影响;放免法显示五氯苯酚0.3μg/ml和0.5μg/ml剂量组显著降低甲状腺球蛋白浓度;五氯苯酚处理FRTL-5细胞12小时后,0.3μg/ml和0.5μg/ml剂量组使FRTL-5细胞摄碘能力显著增强,处理24小时后,FRTL-5细胞摄碘能力无显著改变,但有降低的趋势,高氯酸钠阳性对照组使FRTL-5细胞摄碘能力在12小时和24小时都极显著降低。结论五氯苯酚干扰甲状腺激素作用可能与其使甲状腺球蛋白浓度的改变有关。     

杀草强影响Fischer大鼠甲状腺滤泡上皮细胞甲状腺球蛋白的机制研究

目的 探讨杀草强影响Fischer大鼠甲状腺滤泡上皮细胞(FRTL-5细胞)甲状腺球蛋白(TG)的机制.方法 1、10和100μg/ml杀草强处理FRTL-5细胞后,用3H掺入法测杀草强的细胞毒性;放免法和免疫细胞化学法测杀草强对TG、甲状腺转录因子1(TTF-1)的影响;免疫荧光法检测杀草强对细胞表面促甲状腺素受体(...     

甲状腺素干扰物对甲状腺滤泡细胞分泌甲状腺球蛋白功能的影响

目的了解几种典型甲状腺素干扰物对甲状腺滤泡(FRTL-5)细胞分泌甲状腺球蛋白功能的影响,探讨其干扰甲状腺素水平的细胞学机制及建立甲状腺素干扰物甄别方法的可行性。方法将大鼠FRTL-5细胞体外培养后接种于24孔培养板,每孔细胞数2×105个,待细胞贴壁后分别加入受试物丙硫氧嘧啶、叶枯宁[N,N-甲撑-双(2-氨基-5-巯基-1,3,4-噻二唑)]、磺胺二甲嘧啶和杀草强,各设1组溶剂对照,置CO2孵箱培养48h后,每孔取1ml培养液,用放射免疫法测定甲状腺球蛋白的浓度。结果4个实验组的甲状腺球蛋白浓度与对照组相比均降低,差异有显著性(P<0.05),且可能存在剂量-效应关系。结论降低甲状腺细胞合成或分泌甲状腺球蛋白可能是这4种甲状腺素干扰物的作用机制之一。FRTL-5细胞分泌甲状腺球蛋白的功能是一个相对灵敏的指标,与其他体内体外实验结合可用于甲状腺素干扰物的一阶段甄别(初筛)方法。     

不同锌浓度培养液细胞存活率的测定

为了对锌的细胞毒性提供实验参考 ,利用MTT比色法测定 4种不同锌浓度下HEK 2 93细胞的存活率 ,发现随着培养液锌浓度的增高 ,细胞存活率下降 ,尤其是培养液锌浓度大于 10 0 μmol/L时下降显著。     

四种细胞毒性试验测定柴油机尾气颗粒物提取物急性毒性的比较

目的比较四种体外细胞毒性试验检测柴油机尾气颗粒物(DEP)提取物急性毒性的能力。方法用浓度分别为5、10、20、40、80和160μg/ml的DEP提取物作用于16HBE细胞,于12、24及48h后,通过MTT法、中性红法、乳酸脱氢酶(LDH)法及蛋白测定法测细胞存活率。结果 MTT法在检测急性毒性方面与其它三种方法相比,染毒12h时就表现出了很高的敏感性。随着染毒时间的增加,MTT法与中性红法的敏感性逐渐提高,染毒24h后与对照组相比,各剂量组细胞存活率明显降低(P<0.05)。LDH法测定DEP提取物染毒24h后细胞存活率有所降低,但继续增加染毒时间,存活率不再发生变化。蛋白法测定染毒12h和24h的细胞存活率,仅高剂量组显著降低,染毒48h后,各剂量组细胞存活率均显著降低。结论四种不同的细胞毒性试验测定结果存在差异,MTT法和中性红法比蛋白法和LDH法更为敏感。结合各试验检测的毒性指标可以看出,DEP提取物主要影响16HBE细胞内各细胞器的功能,如线粒体、溶酶体;对于细胞贴壁的影响和细胞膜损伤程度的影响较弱。     

4种方法检测大气颗粒物PM2.5的细胞毒性

目的采用多种检测原理和观察终点的细胞毒性试验综合评估提取PM2.5的细胞毒性效应,为深入研究PM2.5生物学效应提供实验依据。方法用去离子水提取PM2.5,溶于二甲亚砜获得PM2.5悬液。不同浓度PM2.5染毒支气管上皮(HBE)细胞24 h,采用噻唑蓝比色(MTT)、乳酸脱氢酶释放法(LDH法)、台盼蓝拒染法、吖啶橙-溴化乙锭双染法(AO-EB双染法)4种细胞毒性实验评估PM2.5的细胞毒性,并计算半数抑制浓度(IC_(50))。结果去离子水提取的PM2.5溶于二甲亚砜后呈黑褐色,肉眼可见颗粒成分。不同浓度的PM2.5处理HBE细胞24 h后,台盼蓝拒染法(IC_(50)=815.5μg/m L)、LDH释放法(IC_(50)=827.3μg/m L)及AO-EB双染法(IC_(50)=887.5μg/m L)检测结果与空白对照组和溶剂对照组相比,细胞存活率均显著下降(P0.05);而MTT法的细胞存活率检测结果显著高于对照组1.5~4.0倍(P0.05),与细胞实际生长状态不符。结论用去离子水提取PM2.5可减少溶剂带入,能够最大程度反映空气污染实际情况;实验采用的4种方法都可检测出水提PM2.5细胞毒性,但由于样品颜色的特殊性,MTT实验不能准确检测本研究中PM2.5的细胞毒性。     

β-胡萝卜素与香烟烟气颗粒物对体外大鼠肺细胞毒性的交互作用

[目的 ]研究 β 胡萝卜素对香烟烟气颗粒物致肺细胞毒性的交互作用。[方法 ]建立大鼠肺Ⅱ型细胞体外培养模型 ,加入 β 胡萝卜素或 /和香烟烟气颗粒物用MTT比色法检测细胞活性。[结果 ] β 胡萝卜素剂量在 0 1～ 0 5 μg/ml时 ,肺细胞活性明显增加 ;剂量在 1 0～ 2 0 μg/ml时 ,肺细胞活性明显降低。β 胡萝卜素在 0 2 μg/ml剂量时 ,可抑制香烟烟气颗粒物毒性 ;而在 0 5～ 2 0 μg/ml剂量范围内可增强香烟烟气颗粒物的细胞毒性作用。[结论 ] β 胡萝卜素在 0 1～2 0 μg/ml剂量范围内对大鼠肺细胞的生长具有先促进后抑制的双重作用。β 胡萝卜素对香烟烟气颗粒物肺细胞毒性存在交互作用 ,低浓度时表现为拮抗作用 ,高浓度时为协同作用。其交互作用可能是在细胞内实现的     

Induction of hepatic cytochrome P4501A1/2B activity and disruption of thyroglobulin synthesis/secretion by mono-ortho polychlorinated biphenyl and its hydroxylated metabolites in rat cell lines

As the active metabolites of polychlorinated biphenyl (PCBs), hydroxylated polychlorinated biphenyls (OH-PCBs) are found in wildlife and human tissues. They have been proposed as main contributors for endocrine disruption of PCBs in living organisms. In this study, mono-ortho PCB 156 and its hydroxylated metabolites 4'-OH-PCB 159, 4'-OH-PCB 121, and 4'-OH-PCB 72 were selected to investigate the toxic effects on rat hepatoma H4IIE cell line and rat thyroid follicle FRTL-5 cell line at concentrations of 1, 10(2), 10(4) nM. 7-Ethoxyresorufin-O-deethylase (EROD) and 7-pentoxyresorufin-O-dealkylase (PROD) activities were determined with micro-EROD/PROD to indicate cytochrome P4501A1 (CYP1A1) and cytochrome P4502B (CYP2B) induction in the H4IIE cell after exposure for 72 h. To assess thyroid disruption of these compounds, thyroglobulin concentrations also were detected inside FRTL-5 cell with immunocellularchemistry and in its medium with radioimmunoassay after exposure for 24 h. Significant inductions of EROD activity by PCB156 at 10(2) and 10(4) nM (p < 0.05) were observed, but no effects by the three OH-PCBs in H4IIE cell line. 7-Pentoxyresorufin-O-dealkylase activities were induced only by 10(4) nM of PCB156 and the three OH-PCBs (p < 0.05). Meanwhile, significant increases of thyroglobulin concentrations were observed in the medium of FRTL-5 cell exposed to 4'-OH-PCB 121 and 4'-OH-PCB 72 at all of the test concentrations (p < 0.05), but not to the other compounds. The results demonstrated that mono-ortho PCBs mainly could be metabolized to hydroxylated metabolites through CYP1A1 instead of CYP2B. Moreover, after being metabolized, OH-PCBs still sustained the ability to induce PROD activity and did exhibit the disruption on thyroglobulin synthesis/excretion in rat cells.     

避孕套的体外细胞毒性检测实验

目的:通过两种避孕套的体外细胞毒性实验,探讨适合避孕套的细胞毒性检测方法。方法:按照GB/T16886.5的体外细胞毒性评价方法要求,用琼脂覆盖法和MTT比色法检测两种避孕套的细胞毒性。结果:用琼脂覆盖法检测出两种避孕套的细胞毒性均为2级;用MTT比色法检测时,在浸提液浓度为50%时,相对增值率(RGR)避孕套A为5%,避孕套B为7%,两者差异无统计学意义(P>0.05);在浸提液浓度为10%时,避孕套A的RGR为87%,避孕套B为99%,两者差异无统计学意义(P>0.05);在浸提液浓度为20%时,避孕套A的RGR为42%,避孕套B为77%,两者有统计学差异(P<0.05)。结论:由于MTT比色法具有定量评价的优点,更适合避孕套的细胞毒性检测。     

Essential oil of the leaves of Ricinus communis L.: In vitro cytotoxicity and antimicrobial properties

ABSTRACT: BACKGROUND: The aim of the present study was to appraise the antimicrobial activity of Ricinus communis L. essential oil against different pathogenic microorganisms and the cytotoxic activity against HeLa cell lines. METHODS: The agar disk diffusion method was used to study the antibacterial activity of Ricinus communis L. essential oil against 12 bacterial and 4 fungi strains. The disc diameters of zone of inhibition (DD), the minimum inhibitory concentrations (MIC) and the concentration inhibiting 50% (IC50) were investigated to characterize the antimicrobial activities of this essential oil. The in vitro cytotoxicity of Ricinus communis L. essential oil was examined using a modified MTT assay; the viability and the IC50 were used to evaluate this test. RESULTS: The essential oil from the leaves of Ricinus communis L. was analyzed by GC-MS and bioassays were carried out. Five constituents of the oil were identified by GC-MS. The antimicrobial activity of the oil was investigated in order to evaluate its efficacy against twelve bacteria and four fungi species, using disc diffusion and minimum inhibitory concentration methods. The essential oil showed strong antimicrobial activity against all microorganisms tested with higher sensitivity for Bacillus subtilis, Staphylococcus aureus and Enterobacter cloacae. The cytotoxic and apoptotic effects of the essential oil on HeLa cell lines were examined by MTT assay. The cytotoxicity of the oil was quite strong with IC50 values less than 2.63 mg/ml for both cell lines. CONCLUSION: The present study showed the potential antimicrobial and anticarcinogenic properties of the essential oil of Ricinus communis L., indicating the possibilities of its potential use in the formula of natural remedies for the topical treatment of infections.     

天然胶乳橡胶避孕套的体外细胞毒性试验研究

目的研究天橡避的体外细胞毒性,调查国内市售避孕套的细胞毒性现状。方法遵照GB/T16886.5和GB/T14233.2-2005(第2部分:生物学试验方法)体外细胞毒性的实验原则,采用琼脂覆盖法、显微镜观察法、噻唑蓝(MTT)比色法,在小鼠成纤维细胞(L929株)上对受试避。结果用琼脂覆盖法检测,6批不同品牌避孕套均具有2级细胞毒性反应。用显微镜观察法检测,6批不同品牌避孕套(按6 cm2/ml比例浸提)在浸提液浓度为100%、50%、20%和10%时,分别具有4级、4级、2级、1或0级细胞毒性反应。用MTT比色法检测,来自6个品牌的15批避孕套(按6 cm2/ml比例浸提),在浸提液浓度为50%、20%、10%时,分别具有4级(RGR≤15%)、2级(RGR:50%～70%)、1级(RGR≥80%)细胞毒性反应。结论试验表明受试天然胶乳橡胶避孕套均有不同程度的细胞毒性反应。MTT比色法具有定量评价的优点,易于操作,与琼脂覆盖法和显微镜观察法相比更适合避的细试验。     

Iodine status remains critical in mother and infant in Central Anatolia (Kayseri) of Turkey

Summary. Background: Severe iodine deficiency disorders have been eradicated in many parts of the world, but milder forms still exist and may escape detection. Turkey has long been known to be a mild to moderate iodine deficiency area. Aim of the study: The aim of this study was to assess the iodine nutritional status and the thyroid function of pregnant women and their neonates in the region of Kayseri (central Anatolia of Turkey) that appeared to be iodine deficient in previous studies performed before the introduction of mandatory salt iodization. Methods: A cross-sectional voluntary screening study was performed in the Maternity Unit of a university hospital. A total of 70 mothers and their healthy full-term neonates were included in this study. Urinary iodine concentration was estimated in spot urine samples obtained from mothers and their neonates on day 5. All the neonates were breastfed. The iodine content was determined in the breast milk of all mothers on day 5. Serum concentrations of TSH, thyroglobulin (Tg), free triiodothyronine (FT3) and free thyroxine (FT4) were investigated in the cord serum of neonates and compared to those of mothers immediately after parturition Results: The median urinary iodine on day 5 in mothers and their babies were 30.20 and 23.80 µg/l, respectively. These figures are much lower than normal for these age groups (150–200 µg/l). The median iodine content of breast-milk was 73 µg/l. It is again much lower than in iodine sufficient areas, indicating that the status of iodine nutrition of pregnant and lactating women is clearly insufficient. The median concentrations (and ranges) of neonatal TSH, Tg, FT3 and FT4 were 7.44 mU/l, 71.62 ng/ml, 1.30 pg/ml and 1.34 ng/dl respectively. The corresponding levels for the mothers during labor were 2.19 mU/l, 25.65 ng/ml, 1.31 pg/ml and 1.23 ng/dl respectively. The median neonatal serum concentrations of TSH and Tg were significantly higher than the corresponding maternal levels (P < 0.0001, P < 0.0001, respectively) and 27.1% of the neonates had serum TSH concentrations above 10 mU/l and 57.1 % had cord blood serum Tg concentrations above 54 ng/ml. None of the mothers showed TSH concentrations above 5 mU/l and 41.4% had serum Tg concentrations above 30 ng/ml. Conclusion: Iodine deficiency with low urinary iodine excretion and high serum Tg and TSH concentrations were recognized among pregnant women and their babies in Kayseri in spite of the program of salt iodization. National measures are urgently required for improving the correction of iodine deficiency in Turkey. This includes regular supplementation with iodine, starting at preconception or in early pregnancy and continuing during the period of nursing in this region.     

Chemopreventive properties of trans-resveratrol against the cytotoxicity of chloroacetanilide herbicides in vitro

The beneficial effect of trans-resveratrol (RESV) on health is well documented. Our aim was to study the putative preventive effect of RESV on the cytotoxicity of frequently used herbicides (alachlor, acetochlor). Estrogen receptor positive (ER+) MCF-7 human mammary carcinoma, HepG2 (ER+) human hepatocellular carcinoma and VERO estrogen receptor negative (ER-) non-transformed monkey fibroblast cell lines were treated with alachlor and acetochlor (2-500 microg/ml) as toxic agents, and RESV (10 microM) as preventive agent. The MTT dye reduction assay was performed to test cytotoxicity, and flow cytometry to test cell proliferation and apoptosis. RESV is not cytotoxic in the concentration range of 1-100 microM on neither cell lines examined after 24 h, but cytotoxic on Vero and MCF-7 cells at 100 microM after 48h, and on all three cell lines after 72 h. On both ER+ cell lines a stimulation of viability occurs in the low concentration range (0.5-12.5 microM) as detected by the MTT assay. Cell cycle analysis of the culture shows a significant increase of S-phase cells at low concentrations of RESV (10-50 microM) and a decrease in the 100-200 microM concentration range. The ratio of apoptotic cells significantly increases after the administration of 50 microM RESV, depending on the incubation time. The cytotoxicity of 20-65 microg/ml alachlor and 10-65 microg/ml acetochlor was significantly decreased by the addition of 10 microM RESV in Vero ER- cells whereas no significant change was detected on ER+ cell lines MCF-7 and HepG2. These results show that RESV protects non-transformed ER- cells, but has no such effect on ER+ tumor cells.     

The use of recombinant human thyrotropin (Thyrogen) in the diagnosis and treatment of thyroid cancer

The introduction of human recombinant thyrotropin (rhTSH/Thyrogen) into the diagnosis of thyroid cancer has substantially ameliorated the patient's quality of life through the avoidance of debilitating hypothyroidism. With the aim of updating the use of Thyrogen, we report 7 cases which were treated with Thyrogen for diagnostic or therapeutic purposes. All 7 patients were thyroidectomised and radioiodine ablated and all had detectable [> 1 ng/ml] basal serum thyroglobulin (b-Tg) levels. Thyrogen stimulation resulted in a rise of Tg (s-Tg) in all patients. Five patients had negative whole body scanning (WBS) and no clinical or radiological signs of disease. Two patients with a b-Tg value of 5 ng/ml and 11 ng/ml, respectively showed a s-Tg of 17 ng/ml and 84 ng/ml, respectively, whereas WBS was negative. Both of these patients received 100 mCi (3700 MBq) 131I. Owo patients had a positive Tg and positive WBS with skull, lung and hepatic metastases and received 150 131I after preparation with Thyrogen. Six months later one of these patients was free of disease and the other will be evaluated during the coming months. In conclusion, Thyrogen emerges as a reliable and safe agent for the diagnosis of thyroid cancer. Furthermore, it appears that Thyrogen could be used in the treatment of metastases as an alternative to thyroid hormone withdrawal.