Bioaccessibility of selected trace metals in urban PM<Subscript>2.5</Subscript> and PM<Subscript>10</Subscript> samples: a model study

Bioaccessibility of trace metals originating from urban particulate matter was assessed in a worst case scenario to evaluate the uptake and thus the hazardous potential of these metals via gastric juice. Sampling was performed over a period of about two months at the Getreidemarkt in downtown Vienna. Concentrations of the assayed trace metals (Ti, Cr, Mn, Co, Ni, Cu, Zn, Mo, Ag, Cd, Sn, Sb, Tl and Pb) were determined in PM_2.5 and PM₁₀ samples by ICP-MS. The metal concentrations in sampled air were in the low picogram to high nanogram per cubic metre range. The concentrations in PM_2.5 samples were generally lower than those in PM₁₀ samples. The average daily intake of these metals by inhalation for a healthy adult was estimated to be in the range of <1 ng (Tl) to >1,000 ng (Zn). To estimate the accessibility of the inhaled and subsequently ingested metals (i.e. after lung clearance had taken place) in the size range from 2.5- to 10-μm aerodynamic equivalent diameter, a batch-extraction with synthetic gastric juice was performed. The data were used to calculate the bioaccessibility of the investigated trace metals. Extractable fractions ranged from 2.10% (Ti in PM_2.5) to 91.0% (Cd in PM_2.5), thus yielding bioaccessible fractions (PM_2.5–10) from 0.16 ng (Ag) to 178 ng (Cu).     

基于小波变换分析阻抗胃动力信息

研究了基于小波变换提取胃运动信息的新方法,运用小波多分辨分析对采集的体表胃阻抗信号进行分解,去掉呼吸阻抗信号和血流阻抗信号,提取近似成份作为胃收缩信号.该方法能够提取胃运动的信号和同步胃电信号,可对提取信号的主频进行不同频带的分类,计算功率谱参数、描绘动态谱,从而研究胃动力情况.应用小波变换可以有效消除叠加到阻抗信号中的各种干扰,通过与同步胃电信号共同验证,该方法能完成阻抗信号提取,为临床胃动力信息研究提供一种体表无创伤新途径.     

Iridin Induces G2/M Phase Cell Cycle Arrest and Extrinsic Apoptotic Cell Death through PI3K/AKT Signaling Pathway in AGS Gastric Cancer Cells

Iridin is a natural flavonoid found in Belamcanda chinensis documented for its broad spectrum of biological activities like antioxidant, antitumor, and antiproliferative effects. In the present study, we have investigated the antitumor potential of iridin in AGS gastric cancer cells. Iridin treatment decreases AGS cell growth and promotes G2/M phase cell cycle arrest by attenuating the expression of Cdc25C, CDK1, and Cyclin B1 proteins. Iridin-treatment also triggered apoptotic cell death in AGS cells, which was verified by cleaved Caspase-3 (Cl- Caspase-3) and poly ADP-ribose polymerase (PARP) protein expression. Further apoptotic cell death was confirmed by increased apoptotic cell death fraction shown in allophycocyanin (APC)/Annexin V and propidium iodide staining. Iridin also increased the expression of extrinsic apoptotic pathway proteins like Fas, FasL, and cleaved Caspase-8 in AGS cells. On the contrary, iridin-treated AGS cells did not show variations in proteins related to an intrinsic apoptotic pathway such as Bax and Bcl-xL. Besides, Iridin showed inhibition of PI3K/AKT signaling pathways by downregulation of (p-PI3K, p-AKT) proteins in AGS cells. In conclusion, these data suggest that iridin has anticancer potential by inhibiting PI3K/AKT pathway. It could be a basis for further drug design in gastric cancer treatment.     

From Chemistry to Translational Medicine: The Application of Proteomics to Cancer Biomarker Discovery and Diagnosis

The study of complex protein mixtures and their interactions in cells and tissues has been difficult due to the tedious process involved in their characterization and analysis. The recent emergence of fast‐evolving and state‐of‐the‐art proteomics methodologies has provided a rapid and scalable platform for understanding the comprehensive proteome profiles from complex whole tissues or cells of various biological sources. Therefore, proteomics has been increasingly valuable to examine real‐time changes in protein expression of various tissues or body fluids from patients with various diseases, especially cancer, resulting in the identification of clinically useful biomarkers for diagnosis, prognosis and disease staging. In this review, we focus on potential biomarkers for (1) Helicobacter pylori‐associated gastric cancer, (2) hepatocellular carcinoma (HCC), and (3) renal cell carcinoma (RCC). In addition to the conventional gel‐based proteomics (1‐D or 2‐D gels), we have utilized a more advanced proteomic approach by incorporating stable isotope dimethyl labelling and shotgun proteomics strategy in combination with nanoliquid chromatography and tandem mass spectrometry (nanoLC‐MS/MS) to better characterize the biomarkers in several cancer tissues. By establishing a high‐throughput proteomics platform based on multiple reaction monitoring (MRM), we have successfully detected and analyzed potential protein markers at low concentrations in various normal and tumor tissues. This platform not only highlights the utility of proteomics for biomarker discovery but also can be uniquely applied to disease‐oriented translational medicine for diagnosis of diverse types of cancers and other diseases.     

胃癌术中区域动脉灌注联合腹腔缓释化疗的临床研究

目的探讨胃癌术中区域动脉灌注联合腹腔缓释化疗的临床效果。方法将80例进展期胃癌患者随机分为治疗组和对照组,治疗组于胃癌根治术中经肿瘤的主要供血动脉灌注含5-氟尿嘧啶和丝裂霉素的生理盐水灌注液,术毕将5-Fu缓释剂植入肿瘤病灶区域、吻合口周围及淋巴回流区等区域。对照组术中不进行腹腔内干预性治疗。结果两组术后复发及转移率、3年和5年生存率的差异较大,有统计学意义,治疗组优于对照组。结论胃癌术中区域动脉灌注联合腹腔缓释化疗应用于临床,疗效肯定,具有推广应用价值。     

In-vivo and in-vitro testing to assess the bioaccessibility and the bioavailability of arsenic, selenium and mercury species in food samples

In-vivo and in-vitro gastrointestinal (GI) extractions, also known as oral bioaccessibility and bioavailability, are important approaches to assess chemical risk to humans. We give an overview of in-vivo and in-vitro bioaccessibility and bioavailability assays for testing arsenic, selenium and mercury (As, Se and Hg) species from food samples. We critically evaluate the parameters affecting in-vivo and in-vitro processes. In addition, we consider the effect of cooking food on bioaccessibility and bioavailability, and stability and transformation, of species during in-vivo or in-vitro processes. The bioaccessibility and bioavailability of As, Se and Hg species are affected by the sample matrix, cooking food and the experimental conditions applied (gastric and intestinal pH, incubation temperature and residence time). Regarding species degradation and transformation during in-vitro procedures, good stability has been observed for most As species, except for certain arsenosugars. Important transformations during in-vitro processes have been reported for Se species [e.g., conversion of γ-glu-Se-MeSeCys to Se-MeSeCys, and organic Se species (MeSeCys, SeCys2 and SeMet) degradation to inorganic Se]. Finally, we summarize speciation and detection conditions for As, Se and Hg speciation, and quality control to assure reliable measurements.     

S-1联合奥沙利铂方案一线治疗晚期胃癌 有效性及安全性分析

目的探讨S-1联合奥沙利铂方案一线治疗晚期胃癌的有效性及安全性.方法选取60例晚期胃癌患者作为研究对象,随机将其分为研究组和对照组,研究组采用S-1+L-OHP方案进行治疗,对照组采用FOL-FOX方案进行治疗.结果研究组和对照组患者有效率比较差异无统计学意义(P0.05);研究组疾病控制率为80.0%,优于对照组的53.3%,且差异具有统计学意义(P0.05);研究组和对照组中位TTP比较差异具有统计学意义(P0.05);两组中位OS比较差异无统计学意义(P0.05);研究组外周神经毒性发生率明显高于对照组,差异具有统计学意义(P0.05),其余不良反应发生率比较差异均无统计学意义(P0.05).结论 S-1联合奥沙利铂治疗晚期胃癌具有良好的疗效及安全性,与FOL-FOX方案比较,不良反应低,且静脉滴注时间短,患者依从性好.     

间氯苯基锰卟啉-5-氟尿嘧啶配合物的合成及其对癌细胞的抑制活性

合成了4种新5-氟尿嘧啶-卟啉衍生物：5-[3-(2-(5-氟尿嘧啶-1-基)乙氧基)苯基]-10,15,20-三(3-氯苯基)卟啉(1a)、5-[3-(2-(5-氟尿嘧啶-1-基)乙氧基)苯基]- 10,15,20-三(3-氯苯基)锰卟啉(2a)、5-[3-(3-(5-氟尿嘧啶-1-基)丙氧基)苯基]-10,15,20-三(3-氯苯基)锰卟啉(2b)和5-[3-(4-(5-氟尿嘧啶-1-基)丁氧基)苯基]-10,15,20-三(3-氯苯基)锰卟啉(2c),通过UV-Vis、IR、MS及元素分析表征了它们的结构。 用噻唑蓝法（MTT法）测定了化合物2a、2b和2c对人胃癌细胞株BGC-823的抑制活性。 化合物2b的半数抑制浓度IC50为1.34 μmol/L,表明有一定的细胞毒作用。     

采用氧合血红蛋白吸收带的漫反射光谱比率R540/R575检测人胃癌

采用氧合血红蛋白吸收带的平均漫反射光谱比率(R540/R575)对离体的人正常胃、未分化胃腺癌、胃鳞状细胞癌和低分化胃腺癌的上皮粘膜组织进行鉴别诊断.实验采用带积分球附件的分光光度计测量组织样品在400 nm～600 nm的漫反射光谱.实验结果表明,在相同的波长范围内,人的未分化胃腺癌、胃鳞状细胞癌和低分化胃腺癌的上皮粘膜组织的漫反射光的强度较人正常胃的上皮粘膜组织的漫反射光强度要显著地低的,尤其是在氧合血红蛋白的吸收带540 nm和575 nm波长处,人正常胃、未分化胃腺癌、胃鳞状细胞癌和低分化胃腺癌的上皮粘膜组织的平均漫反射光谱比率分别是(94.25±2.4)%,(109±3.0)%,(1032±2.8)%和(98.6±2.6)%.     

鲇鱼幼鱼的胃排空率及其模型分析

为考察肉食性鱼类摄食后胃内含物的变化情况并探究肉食性鱼类消化生理特征,以鲇鱼幼鱼为对象,在(25.0±0.5) ℃温度下采用实验鱼体重8%的泥鳅为饵料进行投喂,分别在摄食后0、1、3、6、12、18、24、36、48 h测定胃内含物湿重、干重并计算占其摄食量的百分比,随后分别采用线性、指数、平方根3种数学模型对胃内含物百分比的变化进行拟合并比较上述不同方法的拟合程度.结果显示,摄入食物的湿重、干重均呈现随时间减少的趋势;3种模型均能较好地拟合鲇鱼幼鱼的胃内含物百分比的变化(p<0.01).研究认为3个模型中平方根模型对湿重和干重百分比变化的拟合最佳,分别为Y 0.5=10.11-0.26t (r2=0.94,p<0.01) 和Y 0.5=10.27-0.24t (r2=0.87,p<0.01).