充血性心力衰竭伴消化道症状患者的胃液体排空功能

观察了２７例充血性心力衰竭伴消化道症状患者的胃液体排空功能。结果发现，与正常人比较，心力衰竭患者胃排空时间延迟（２８．１２±６．３３ｍｉｎ比３５．３０±１０．２８ｍｉｎ，Ｐ＜０．０１），胃体收缩频率降低（Ｐ＜０．００１），血浆胃泌素水平较低。消化道症状及心力衰竭严重程度与胃排空障碍有关。说明胃动力学障碍是充血性心力衰竭患者产生消化道症状的机制之一。     

Concurrent use of transgenic plants expressing a single and two Bacillus thuringiensis genes speeds insect adaptation to pyramided plants

Transgenic plants expressing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) were grown on over 13 million ha in the United States and 22.4 million ha worldwide in 2004. Preventing or slowing the evolution of resistance by insects ("resistance management") is critical for the sustainable use of Bt crops. Plants containing two dissimilar Bt toxin genes in the same plant ("pyramided") have the potential to delay insect resistance. However, the advantage of pyramided Bt plants for resistance management may be compromised if they share similar toxins with single-gene plants that are deployed simultaneously. We tested this hypothesis using a unique model system composed of broccoli plants transformed to express different Cry toxins (Cry1Ac, Cry1C, or both) and a synthetic population of the diamondback moth (Plutella xylostella) carrying genes for resistance to Cry1Ac and Cry1C at frequencies of approximately 0.10 and 0.34, respectively. After 24-26 generations of selection in the greenhouse, the concurrent use of one- and two-gene plants resulted in control failure of both types of Bt plants. When only two-gene plants were used in the selection, no or few insects survived on one- or two-gene Bt plants, indicating that concurrent use of transgenic plants expressing a single and two Bt genes will select for resistance to two-gene plants more rapidly than the use of two-gene plants alone. The results of this experiment agree with the predictions of a Mendelian deterministic simulation model and have important implications for the regulation and deployment of pyramided Bt plants.     

Multidrug resistance reversal in human gastric carcinoma cells by neferine

AIIVI: To investigate the reversal effect of neferine on multidrug resistance in human gastric carcinoma cell line. METHODS: Cells of a human gastric cancer cells line, SGC7901, and its vincristine (VCR) -resistant variant, SGC7901/VCR, were cultivated with or without neferine and/or VCR. The cytotoxic effect of VCR was evaluated by the MTT assay. Cell apoptosis induced by VCR was determined by flow cytometry(FCM). The expression of P-glycoprotein (P-gp) and a multidrug-resistance-associated protein (MRP) in cells was examined by immunofluorescence and FCM. RESULTS: Neferine at the concentration from 2.5 μmol/L to 10 μmol/L had no cytotoxicity to SGC7901 cells, and its variant SGC7901/VCR cells. The ICso of VCR against SGC7901 and SGC7901/VCR cells was 0.059 μg/mL and 2.32 μg/mL, respectively, indicating that SGC7901/VCR cells were 39 times more resistant to VCR than its parent SGC7 901 cells. After treatment with neferine at concentrations of 2.5, 5 and 10 μmol/L, the IC50 of VCR to SGC7901/VCR cell line decreased to 0.340, 0.128 and 0.053 μg/mL, respectively,thus, increased the chemosensitivity by 6.8-, 18.1- and 43.8-fold, respectively. SGC7901/VCR cells were apoptosis resistant to VCR. Neferine (2.5, 5 and 10 μmol/L) promoted the VCR-induced apoptosis of SGC7901/VCR cells in a dosedependent manner. The expressions of P-gp and MRP were strongly positive in SGC7901/VCR cells, which were significantly down-regulated after treatment with neferine (10 μmol/L)for 24 h. CONCLUSION: Neferine reverses multidrug resistance of human gastric carcinoma SGC7901/VCR cells, which may be associated with the down-regulations of P-gp and MRP expression in SGC701/VCR cells.     

Profiling of differentially expressed chemotactic-related genes in MCP-1 treated macrophage cell line using human cDNA arrays

AIM: To study the global gene expression of chemotactic genes in macrophage line U937 treated with human monocyte chemoattractant protein-1 (MCP-1) through the use of ExpreeChipTMO2 cDNA array. METHODS: Total RNA was extracted from MCP-1 treated macrophage line U937 and normal U937 cells, reversely transcribed to cDNA, and then screened in parallel with HO2 human cDNA array chip. The scanned result was additionally validated using RT-PCR. RESULTS: The result of cDNA array showed that one chemotactic-related gene was up-regulated more than two-fold (RANTES) and seven chemotactic-related genes were down-regulated more than two-fold (CCR1, CCR5, ccll6, GROβ, GROγ,IL-8 and granulocyte chemotactic protein 2) in MCP-1 treated U937 cells at mRNA level. RT-PCR analysis of four of these differentially expressed genes gave results consistent with cDNA array findings. CONCLUSION: MCP-1 could influence some chemokine and receptor expressions in macrophages in vitro. MCP-1 mainly down-regulates the expression of chemotactic genes influencing neutrophilic granulocyte expression (GROβ, GROγ, IL-8 and granulocyte chemotactic protein 2), and the mRNA level of CCR5, which plays a critical role in many disorders and illnesses.     

Rapid detection of α-amanitin and β-amanitin in rat plasma by ultra-performance liquid chromatography–tandem mass spectrometry and its application to the toxicokinetic study of Lepiota brunneoincarnata

Forensic Toxicology - Lepiota brunneoincarnata is a well-known poisonous mushroom and is responsible for fatal mushroom poisoning cases worldwide. α-Amanitin and β-amanitin are the main...     

千岛湖供水对杭州市主城区饮用水中总放射性水平的影响

目的调查分析千岛湖成为杭州市主城区水源前后, 杭州市饮用水中的总放射性水平。方法自2012年起, 每年分别在丰水期和枯水期采集杭州市主城区的水源水、出厂水和末梢水, 测定总α总β放射性活度浓度并进行比较分析。结果 2012—2020年杭州主城区3类水样总放射性活度浓度均低于《生活饮用水卫生标准》(GB 5749-2006)规定的限值, 3类水样在丰水期和枯水期监测结果比较差异无统计学意义(P>0.05);千岛湖湖水中总α(0.008±0.000)、总β(0.034±0.013)放射性活度浓度均小于钱塘江下游段和东笤溪, 差异具有统计学意义(Z=-3.235, -4.058, -2.181, -4.577, P<0.05);千岛湖供水前后, 杭州市主城区的出厂水和末梢水中总α总β放射性活度浓度差异无统计学意义(P>0.05)。结论 2012—2020年, 杭州市主城区饮用水中总放射性水平较低, 处于安全水平。千岛湖水总放射性水平低于钱塘江下游段和东苕溪, 千岛湖成为主要水源后, 未对杭州市主城区饮用水中总放射性产生影响。     

北京地区急性呼吸道感染住院患儿腺病毒感染临床特征

目的比较北京地区急性呼吸道感染住院患儿中不同型别腺病毒感染临床特征, 明确腺病毒分型的临床必要性。方法采用横断面研究, 纳入2017年11月至2019年10月在首都儿科研究所附属儿童医院因急性呼吸道感染住院的9 022例次患儿呼吸道标本, 经直接免疫荧光(DFA)和(或)核酸检测确定为腺病毒阳性者进行五邻体、六邻体及纤维蛋白基因扩增并测序, 构建系统进化树区分腺病毒型别。收集并分析腺病毒主要型别感染患儿的实验室检查、影像学资料等临床资料, 采用t检验、U检验、χ2检验进行型别间临床特征差异的统计学分析。结果 9 022例次急性呼吸道感染住院患儿中腺病毒阳性检出率为4.34%(392例次), 成功分型205例, 其中男131例、女74例, 年龄22.6(6.7, 52.5)月龄, 3型腺病毒阳性102例(49.76%), 7型86例(41.95%), 1、2、4、6、14、21型共17例。7型与3型腺病毒感染患儿临床特征比较, 在出现喘息[10例(11.63%)比25例(24.51%)]、白细胞计数>15×109/L[4例(4.65%)比14例(13.73%)]、白细胞计数<...     

Induction of cellular glutathione and glutathione S-transferase by 3H-1,2-dithiole-3-thione in rat aortic smooth muscle A10 cells: protection against acrolein-induced toxicity

There is increasing evidence that aldehydes, including acrolein generated endogenously during the degradation process of biological molecules or the metabolism of foreign chemicals may be involved in the pathogenesis of cardiovascular diseases, such as atherosclerosis. Because glutathione (GSH) and GSH S-transferase (GST) are a major cellular defense against the toxic effects of reactive aldehydes, in this study we have characterized the inducibility of GSH and GST by the unique chemoprotective agent, 3H-1,2-dithiole-3-thione (D3T) and their protective effects against acrolein-induced toxicity in rat aortic smooth muscle A10 cells. Incubation of rat aortic A10 cells with micromolar concentrations of D3T resulted in a concentration- and time-dependent induction of both GSH and GST. Treatment of A10 cells with D3T also led to induction of gamma-glutamylcysteine synthetase, the key enzyme involved in GSH biosynthesis. Notably, the levels of GSH and GST remained higher than basal levels 72 h after removal of D3T from the culture media. To examine the protective effects of D3T-induced GSH and GST against reactive aldehyde-mediated toxicity, A10 cells were pretreated with D3T and then exposed to acrolein. Pretreatment of A10 cells with D3T resulted in a marked decrease of acrolein-induced toxicity as determined by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide reduction assay and morphological changes. To further demonstrate the involvement of GSH and GST in protecting against acrolein-induced toxicity, buthionine sulfoximine (BSO) and sulfasalazine were used to inhibit cellular GSH biosynthesis and GST activity, respectively. Either depletion of cellular GSH by BSO or inhibition of cellular GST by sulfasalazine led to a marked potentiation of acrolein-induced toxicity in A10 cells. Furthermore, co-treatment of cells with BSO was found to greatly abolish the protective effects of D3T on acrolein-induced toxicity. Taken together, our results demonstrate for the first time that both GSH and GST in aortic smooth muscle cells can be induced by D3T, and that this increased cellular defense affords great protection against reactive aldehyde-induced cardiovascular cell injury.