霉菌毒素T-2Toxin酶联免疫吸附测定方法

用T - 2毒素免疫家兔 ,获得了抗T - 2毒素的多克隆抗体 ,运用该抗体建立了检测玉米中T - 2毒素的间接竞争性酶联免疫吸附测定法 .该法最低检出量为 1 0 ppb ,平均回收率为 32 %～43%.

基于转录组学分析T-2毒素诱导细胞凋亡作用机制

T-2毒素是一种强毒性单端孢霉烯族毒素,具有多器官效应毒性。为了解T-2毒素对不同细胞系毒性的影响及作用机制,作者分析了T-2毒素暴露对4种细胞系氧化应激、Ca^(2+)水平和凋亡的影响,采用细胞转录组学等技术分析了T-2毒素作用于敏感细胞的关键基因和信号通路。结果表明,相同诱导剂量下,BV2小胶质细胞和HepG2肝癌细胞对T-2毒素敏感,细胞内活性氧(ROS)和Ca^(2+)水平显著升高(P<0.05),细胞凋亡程度高。转录组学和逆转录-聚合酶链式反应(RT-PCR)结果显示,T-2毒素可通过MAPK/AP-1、TNF-NF-κB信号通路并上调AP-1、白细胞介素-6(IL-6)等因子水平引起BV2细胞炎症反应。而与氧化应激和凋亡相关的PI3K/AKT、PERK/P53/Casp3信号通路,通过下调Akt、SIRT1等促凋亡因子并上调超氧化物歧化酶促进了HepG2细胞的凋亡。T-2毒素分别通过促炎和氧化应激相关信号通路诱导BV2细胞和HepG2细胞凋亡,说明T-2毒素可通过不同的分子机制对不同器官产生特异性毒性效应。

辉光放电等离子体降解啤酒中T-2毒素

目的:探讨辉光放电等离子体(GDP)降解啤酒中T-2毒素的最佳工艺及对啤酒理化指标的影响。方法:通过Box-Behnken方法进行四因素三水平的响应面优化试验,确定啤酒中T-2毒素的最佳降解条件。结果:当放电电压为570 V,作用时间为18 min,放电电流为99 mA,T-2毒素初始质量浓度为8.5μg/mL时,T-2毒素降解效率最高(89.21%);经GDP处理后,啤酒泡持性显著降低(P<0.05),其他指标无明显变化。结论:通过响应面优化模型获得的GDP最佳降解条件可以用于啤酒中T-2毒素的降解;GDP处理能够影响啤酒泡持性,但对其他指标无明显影响。

氧化锌纳米颗粒光催化降解T-2毒素性能分析

为了利用光催化技术实现T-2毒素的高效、绿色降解,本研究采用绿色温和的溶剂水热法制备出结晶度高、分散性良好的0D ZnO纳米颗粒光催化材料,并通过高分辨透射电子显微镜、瞬态光电流响应等表征手段对其性质以及光催化降解T-2毒素性能、影响因素和机理进行探究。结果表明:成功制备得到平均粒径约为43.23 nm的ZnO纳米颗粒,经条件优化后可以在240 min内通过光催化降解去除超过95%初始质量浓度为5μg/mL的T-2毒素,降解动力学常数达0.0299μg/(mL·min),催化剂最佳质量浓度为0.5 mg/mL,最佳适用体系的pH值为5~9。光电表征结果确定了ZnO具有良好的光吸收和响应性能以及电荷分离性能,并确定羟自由基在T-2毒素降解中起主导作用。本实验结果可为相关领域绿色高效降解、转化和去除T-2毒素提供有效理论参考和技术支持。

碳化钒免疫层析法检测玉米中T-2毒素

旨在构建一种碳化钒免疫层析试纸条,用于现场灵敏检测玉米中T-2毒素。通过超声辅助-液相剥离法合成碳化钒纳米片(vanadium carbide nanosheets,VCNSs),与T-2单克隆抗体(T-2 monoclonal antibody,T-2-mAb)偶联标记,作为信号探针。基于竞争原理,样品中的T-2毒素与检测线(T线)上T-2抗原竞争结合黑色的VCNSs-mAb探针,试纸条T线读值与T-2毒素质量浓度呈反比。以空白试纸条T线显色情况(信号读值>800,MD-600金标读数仪检测)和0.5、1.5 ng/mL T-2毒素的抑制率为优化指标,获得最佳实验条件,建立标准曲线。结果表明:该方法检测T-2毒素的线性范围在0.14~0.78 ng/mL之间、视觉检出限为0.25 ng/mL、消线值为1.5 ng/mL、半抑制浓度为0.344 ng/mL,灵敏度较传统胶体金试纸条提高了5.6倍。此外,该方法与其他5种常见真菌毒素均无交叉反应。针对玉米样品进行真实检测,回收率在92.8%~117.2%之间、变异系数均小于9.13%、检出限为5.06μg/kg。综上所述,该方法具有操作简便、快速灵敏和成本低等优点,为谷物中T-2的检测提供一定的现场快速检测技术。

T-2毒素毒性分子作用机制与脱毒的研究进展

T-2毒素是一种A类单端孢霉烯族毒素,具有高度致毒作用、毒性较难降解等特点,严重威胁人类和动物安全。目前,用于T-2毒素脱毒的方法有物理吸附法、化学试剂中和法、微生物分解法等。但T-2毒素导致的中毒反应的分子机制还尚未明确,可能涉及多个方面,如线粒体损伤、细胞自噬、免疫逃逸、细胞凋亡等。因此,文章主要探讨了T-2毒素毒性作用分子机制以及T-2毒素脱毒的研究进展,为T-2毒素的深入研究提供参考。

我国饲料原料和配合饲料中T-2毒素、赭曲霉毒素A和伏马毒素的污染研究

本试验旨在研究我国饲料原料和配合饲料中T-2毒素、赭曲霉毒素A(OTA)和伏马毒素(FUM)的单独及联合污染情况。分别对从我国不同地区采集474、385和1905份饲料原料和配合饲料样品,进行T-2毒素、OTA和FUM含量检测。结果显示:饲料原料和配合饲料中T-2毒素、OTA和FUM总污染率分别为26.8%、61.8%和59.3%,其含量平均值分别为0~45.8μg/kg、0.3~11.1μg/kg和0~16.3 mg/kg。值得注意的是,分别有0.4%、0.3%和0.5%的饲料原料和配合饲料中T-2毒素、OTA和FUM含量超过了我国《饲料卫生标准》,并且,60%以上的饲料原料中霉菌毒素的联合污染率达30.3%~88.9%。由此可见,我国饲料原料和配合饲料中T-2毒素、OTA和FUM的污染较严重,生产中加强监测我国饲料原料和配合饲料中上述霉菌毒素的污染情况和实施相关防控措施尤为重要。

The roles of carboxylesterase and CYP isozymes on the in vitro metabolism of T-2 toxin

Background: T-2 toxin poses a great threat to human health because it has the highest toxicity of the currently known trichothecene mycotoxins. To understand the in vivo toxicity and transformation mechanism of T-2 toxin, we investigated the role of two principal phase Ⅰ drug-metabolizing enzymes(cytochrome P450 [CYP450] enzymes) on the metabolism of T-2 toxin, which are crucial to the metabolism of endogenous substances and xenobiotics. We also investigated carboxylesterase, which also plays an important role in the metabolism of toxic substances.Methods: A chemical inhibition method and a recombinant method were employed to investigate the metabolism of the T-2 toxin by the CYP450 enzymes, and a chemical inhibition method was used to study carboxylesterase metabolism. Samples incubated with human liver microsomes were analyzed by high performance liquid chromatography-triple quadrupole mass spectrometry(HPLC- Qq Q MS) after a simple pretreatment.Results: In the presence of a carboxylesterase inhibitor, only 20% T-2 toxin was metabolized. When CYP enzyme inhibitors and a carboxylesterase inhibitor were both present, only 3% of the T-2 toxin was metabolized. The contributions of the CYP450 enzyme family to T-2 toxin metabolism followed the descending order CYP3A4, CYP2E1, CYP1A2, CYP2B6 or CYP2D6 or CYP2C19.Conclusions: Carboxylesterase and CYP450 enzymes are of great importance in T-2 toxin metabolism, in which carboxylesterase is predominant and CYP450 has a subordinate role. CYP3A4 is the principal member of the CYP450 enzyme family responsible for T-2 toxin metabolism. The metabolite produced by carboxylesterase is HT-2, and the metabolite produced by CYP 3A4 is 3'-OH T-2. The different metabolites show different toxicities. Our results will provide useful data concerning the toxic mechanism, the safety evaluation, and the health risk assessment of T-2 toxin.

STUDY ON THE EFFECT OF T-2 TOXIN AND SELENIUM ON CD44 EXPRESSION IN THE CULTURED HUMAN FETAL CHONDROCYTES IN VITRO

Objective To investigate the effect on the structure of reestablished cartilage in vitro and CD44 expression on chondrocytes and compare the inducing effect on the reestablished cartilage in vitro between cortical bone matrix gelatin and cancellous bone matrix gelatin. Methods To plant human fetal chondrocytes on the BMG, the damage of the cultured chondrocytes was observed by the optical microscope (HE staining). The immunohistochemistry of CD44 was quantitative analysis by the image collection and analysis system. Results With the increasing concentration of T 2 toxin, the damage of chondroytes was more and more evident and CD44 expression was lowered. After adding selenium, the damage was relieved and CD44 expression increased. The density of chondrocytes on the cortical bone matrix gelatin was much higher than that on the cancellous bone matrix gelatin. Conclusion T 2 toxin can lower the CD44 expression on the chondrocytes and adding selenium can relieve the damage caused by T 2toxin and increased CD44 expression. The inducing effect on reestablished cartilage in vitro of cortical bone matrix gelatin was much higher than that of cancellous bone matrix gelatin.

Comparison of T-2 Toxin and HT-2 Toxin Distributed in the Skeletal System with That in Other Tissues of Rats by Acute Toxicity Test

Twelve healthy rats were divided into the T-2 toxin group receiving gavage of 1 mg/kg T-2 toxin and the control group receiving gavage of normal saline. Total relative concentrations of T-2 toxin and HT-2 toxin in the skeletal system（thighbone, knee joints, and costal cartilage） were significantly higher than those in the heart, liver, and kidneys（P 〈 0.05）. The relative concentrations of T-2 toxin and HT-2 toxin in the skeletal system（thighbone and costal cartilage） were also significantly higher than those in the heart, liver, and kidneys. The rats administered T-2 toxin showed rapid metabolism compared with that in rats administered HT-2 toxin, and the metabolic conversion rates in the different tissues were 68.20%-90.70%.

Increased Chondrocyte Apoptosis in Kashin-Beck Disease and Rats Induced by T-2 Toxin and Selenium Deficiency

Objective To investigate chondrocyte apoptosis and the expression of biochemical markers associated with apoptosis in Kashin-Beck disease（KBD） and in an established T-2 toxin-and selenium（Se） deficiency-induced rat model. Methods Cartilages were collected from the hand phalanges of five patients with KBD and five healthy children. Sprague-Dawley rats were administered a selenium-deficient diet for 4 weeks prior to T-2 toxin exposure. The apoptotic chondrocytes were observed by terminal deoxynucleotidyl transferase d UTP nick end labeling staining. Caspase-3, p53, Bcl-2, and Bax proteins in the cartilages were visualized by immunohistochemistry, their protein levels were determined by Western blotting, and m RNA levels were determined by real-time reverse transcription polymerase chain reaction. Results Increased chondrocyte apoptosis was observed in the cartilages of children with KBD. Increased apoptotic and caspase-3-stained cells were observed in the cartilages of rats fed with normal and Se-deficient diets plus T-2 toxin exposure compared to those in rats fed with normal and Se-deficient diets. Caspase-3, p53, and Bax proteins and m RNA levels were higher, whereas Bcl-2 levels were lower in rats fed with normal or Se-deficiency diets supplemented with T-2 toxin than the corresponding levels in rats fed with normal diet. Conclusion T-2 toxin under a selenium-deficient nutritional status induces chondrocyte death, which emphasizes the role of chondrocyte apoptosis in cartilage damage and progression of KBD.

Experimental Haematobiochemical Alterations in Broiler Chickens Fed with T-2 Toxin and Co-Infected with IBV

The purpose of this experimental study was to evaluate and record the effects of T-2 toxicity alone and in association with IBV infection on haematobiochemical parameters. A total of 128 one-week-old chicks were divided into four groups of 32 birds each and were treated respectively with T-2 toxin alone, IBV alone, T-2 toxin and co-infected with IBV, and no treatment (control) for a period of 6 weeks. Haematologically, the birds treated with T-2 toxin developed anaemia as indicated by significant decrease in haemoglobin levels, total erythrocyte counts and packed cell volume values;leucopenia, lymphocytopenia heterophilia and thrombocytopenia. The IBV infected birds exhibited lymphocytophilia and heteropoenia;the degrees of severity of leucopenia, lymphocytopenia heterophilia and thrombocytopenia were more pronounced in T-2+IBV groups. The serum biochemistry revealed hypoproteinemia and hypoalbuminemia in all the treated groups consistently. Besides, hypoglobulinemia and increased levels of alanine aminotransferase in T-2+IBV, and increased levels of alkaline phosphatase in toxin group alone were recorded. The changes in biochemical parameters were more in magnitude in the combination treatment group and their severity increased with duration of treatment. It was concluded that T-2 toxin made the birds more susceptible to IBV infection.

QuEChERS-质谱联用仪法测定发酵茶中T-2毒素含量

本文建立QuEChERS-液相质谱联用法测定发酵茶中T-2毒素的含量。茶叶样品粉碎后,样品经乙腈超声均质提取,HC-C18去除大部分杂质,采用增强型碳氢键的非极性化合物PSA净化后,使用高性能液相色谱-串联质谱法多反应监测扫描模式进行定性定量分析。T-2毒素在5~100 ng·mL^(-1)浓度范围内呈现良好的线性关系,线性相关系数为0.999,检出限为5μg·kg^(-1),在5、20、80μL三个不同加标水平下,T-2毒素回收率在85.01%~87.80%内,相对标准偏差(RSD)为1.05%。该方法灵敏度高、回收率稳定、检测快速、定量准确。适用于检测发酵茶叶中的T-2毒素。

Efficacy of Biological Control and Cultivar Resistance on <i>Fusarium</i>Head Blight and T-2 Toxin Contamination in Wheat

Laboratory and green house experiments were carried out to evaluate the efficacy of fungicides, biological agents and host resistance in managing FHB and the associated T-2 toxin. In vitro activity of fungicides and antagonists was determined by paired culture method. Effect of microbial agents on FHB severity and mycotoxin content was determined by co-inoculating F. graminearum and F. poae with Alternaria spp., Epicoccum spp. and Trichoderma spp. Fungicides Pearl? (500 g/L carbendazim), Cotaf? (50 g/L hexaconacole), Thiovit? (micronised sulphur 80% w/w) and Folicur? (430 g/L tebuconazole) were the standard checks. Host resistance was determined by inoculating F. poae and F. graminearum to four wheat cultivars and fifteen lines in pot ex-periments. Fungicides resulted in 100% inhibition of pathogen radial growth in in vitro while microbial agents suppressed pathogen growth by up to 53%. Thiovit? and Trichoderma were the most effective in reducing FHB severity in green house pot experiments. The wheat cultivars and lines varied in susceptibility with cultivar Njoro BW II showing least susceptibility while line R1104, cv. Mbuni and cv. KIBIS were most susceptible. All the wheat cultivars and lines accumulated T-2 toxin by up to 5 to 28 μg/kg. The results indicated that neither fungicides nor antagonists can solely be relied on in managing FHB and toxin accumulation. Therefore, integration of biocontrol agents, fungicides and further breeding efforts to improve lines and cultivars with promising resistance to FHB and T2-toxin contamina-tion is recommended.

Evaluation of Gojiextract and Charcoal as Antioxidant on T-2 Toxin Administration Onliver Male Mice

With a view to study the effects of exposure to T-2 toxin and their amelioration by Goji extract or charcoal, male mice were treated with a sublethal dose of T-2 toxin (200 μg/kg B.W) intraperitoneally. T-2 Toxin showed an increase (P ≤ 0.05) in blood of ALT, ALP, Total Lipids, TAS, and TNF. These were decreased by Goji extracts or charcoal, and were improved partially by the two treatments. It is concluded that the treatment of rats with Goji extract or charcoal ameliorated the adverse effects of toxins but the results suggest that Goji extracts may be used as antioxidant and antidote rather than charcoal for T-2 Toxin in mice.

Epide miological Study on the Cause of Osteoarthrosis Caused by T_2 Toxin in the Grain

采用 Ｋａｌｌｍａｎ 等人的诊断标准，对哈尔滨市区和富裕、双城、尚志等地农村５０ 岁以上３８０ 例普通居民手骨关节病（ Ｏｓｔｅｏａｒｔｈｒｏｓｉｓ ， Ｏ Ａ） 进行 Ｘ 线检查。结果表明，各地的手 Ｏ Ａ 检出率均超过６０ ％ 以上，病情不容轻视。利用病例对照调查法观察与中老年人手 Ｏ Ａ 相关的危险因素，发现与主食种类有关，面粉（ Ｏ Ｒ＝ ３ ．０２） 、玉米面（ Ｏ Ｒ＝ ２ ．４１） 与大米（ Ｏ Ｒ＝ ０ ．３０） 相比，是手 Ｏ Ａ 的危险因素。采用历史前瞻性调查方法，证明了主食中 Ｔ２ 毒素含量与手 Ｏ Ａ 检出率之间存在“剂量效应”联系。据此，作者认为 Ｔ２ 毒素有可能成为 Ｏ Ａ 的致病因子之一。

Occurrence of <i>Fusarium</i>species and associated T2-toxin in Kenyan wheat

Survey covering 120 wheat fields was conducted in three wheat-growing districts of Kenya during the 2008 cropping season to determine the incidence of Fusarium head blight (FHB) and T2-toxin contamination in grain. FHB incidence was determined as the number of blighted ears per 10m2. Information gathered included wheat production practices, rainfall and temperature data. Fungal pathogens were isolated from wheat stems, heads, straw, grains and soil and identified based on cultural and morphological characteristics. Wheat grain samples were analyzed for T2-toxin by competitive Enzyme Linked Immunosorbent Assay (ELISA). High FHB incidences of up to 88% were recorded. Fungal genera isolated included Fusarium, Epicoccum, Trichoderma, Alternaria and Penicilium. Wheat plant parts with high infection with Alternaria and Epicoccum had corresponding low levels of Fusarium spp. Whereas Fusarium spp. were the most common fungal pathogens in stems, heads and soil, Epicoccum was frequently isolated from straw and grains. Fusarium speciesisolated included F. poae, F. graminearum, F. stilboides, F. verticilloides, F. fusarioides, F. tricinctum and F. heterosporum with F. poae and F. graminearum accounting for approximately 40% of all Fusarium infections. T-2 toxin was detected in all the grain samples and varied from 3 to 22 ppb. The study showed that FHB and T2-toxin are prevalent in the study districts and the high diversity of Fusarium species implies a challenge in FHB management as well as a risk of chronic T2-toxin exposure to humans and livestock.

T-2毒素对软骨Ⅱ型胶原蛋白和蛋白聚糖合成的影响以及硒的保护作用

目的探讨T-2毒素对软骨细胞主要间质成分Ⅱ型胶原蛋白和蛋白聚糖合成的影响和硒的保护作用。方法采用 MTT法检测T-2毒素对软骨细胞存活率的影响;用TB染色法检测人软骨细胞蛋白聚糖表达;免疫组织化学检测人软骨细胞胶原蛋白Ⅱ表达;RT-PCR检测人软骨细胞Ⅱ型胶原蛋白和蛋白聚糖mRNA表达。结果 T-2毒素在浓度为 0．001-2 mg／L的范围内,对软骨细胞的作用呈较典型的浓度依赖关系和时间依赖关系,而且随着作用时间的延长,浓度依赖关系更加明显。T-2毒素(10～20μg／L)可以抑制软骨细胞Ⅱ型胶原蛋白和蛋白聚糖的合成及其mRNA表达。而加硒能较明显刺激软骨细胞蛋白聚糖mRNA表达,部分减弱T-2毒素的这种抑制,有一定的保护作用,但不显示对T-2 毒素引起的Ⅱ型胶原蛋白及其mRNA表达的保护作用。结论 T-2毒素对软骨细胞Ⅱ型胶原蛋白和蛋白聚糖合成有明显的抑制作用,微量元素硒对T-2毒素引起的软骨细胞蛋白聚糖改变有一定保护作用。

大骨节病和克山病老病区粮食中T-2毒素和黄绿青霉素污染状况调查

目的观察大骨节病与克山病老病区丰田村和林茂村地产粮食中T鄄2毒素和黄绿青霉素(CIT)的污染状况。方法选40岁以上自愿者作右手X线拍片检查,评估大骨节病历史患病情况;收集文献数据评估克山病历史病情;用ELISA法和高效液相色谱(HPLC)法检测病区地产粮食T鄄2毒素和CIT。结果丰田村和林茂村成人大骨节病患病率很高,是历史上的严重病区。地产面粉中T鄄2毒素阳性检出率为77.78%,T鄄2毒素平均水平为120.64 μg/kg;地产玉米面中CIT阳性检出率为42.31%,CIT毒素平均水平为12.33 μg/kg,均明显地高出本省市场同类粮食。结论丰田村和林茂村是大骨节病、克山病历史上的严重病区,地产粮食中T鄄2毒素、CIT 水平仍然相当高,如果不是当地粮食占居民主食中的比例已经很小(< 20%),这两种病的当前检出率也许达不到现在程度的低水平。

T-2毒素对胎儿软骨细胞凋亡、Bcl-2和Bax表达的影响及硒的保护作用

目的探讨T-2毒素对软骨细胞凋亡的作用,和对凋亡调控蛋白Bcl-2与Bax表达的影响,以及微量元素硒对软骨细胞的保护作用.方法采用电镜,Annexin V/PI法检测T-2毒素致人软骨细胞凋亡的情况,采用流式细胞仪检测凋亡相关蛋白Bcl-2和Bax的表达.结果 T-2毒素可引起软骨细胞发生凋亡的典型电镜形态改变;不同浓度(1～20μg/L)的T-2毒素均可以引起软骨细胞早期凋亡率和晚期凋亡率明显增加,且在一定范围内呈浓度依赖性,T-2毒素浓度为20μg/L时早期凋亡率最高达5.60%,晚期凋亡率最高达8.61%.生理浓度的微量元素硒可部分减弱T-2毒素引起的凋亡;不同浓度(1～20μg/L)的 T-2毒素都能引起Bcl-2和Bax表达水平提高,浓度为10～20μg/L时,Bax/Bcl-2比值升高;硒能部分对抗T-2毒素引起的Bcl-2和Bax 表达的提高,使Bax/Bcl-2比值下降,以降低凋亡率.结论 T-2毒素在浓度为1～20μg/L时,可以引起软骨细胞凋亡;T-2毒素引起的软骨细胞凋亡与软骨细胞内Bax/Bcl-2比值升高有关,硒对T-2毒素引起的软骨细胞凋亡有一定保护作用.