In vitro antioxidant and protective effects of corn peptides on ethanol-induced damage in HepG2 cells

To assess the effect of corn peptides (CPs) as an antioxidant on ethanol (EtOH)-induced oxidative stress in HepG2 cells, the cells were preincubated with CPs for 4?h before treated with EtOH. Methyl thiazolyl tetrazolium and flow cytometry assay were performed to detect the viability of CP-treated HepG2 cells and control cells. The activities of lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST), malondialdehyde (MDA) and superoxide dismutase (SOD) were determined by corresponding kits, respectively. The results showed that treatment with 300?mmol/L EtOH for 24?h resulted in a death of around 50% of the HepG2 cells. Pretreatments of appropriate concentrations of CPs (more than 5?mg/mL, particularly at 20?mg/mL) significantly prevented EtOH-induced cytotoxicity and reduced the increase of ALT, AST, LDH and MDA contents, as well as inhibited the reduction of SOD contents in the HepG2 cells, indicating that CPs protected the cells from oxidative damage induced by EtOH metabolism, and thus had a great application potential in hepatoprotective nutraceuticals.     

高效液相色谱法测定玉米粉中黄曲霉毒素B_1含量的不确定度评定

目的评定高效液相色谱(HPLC)法测定玉米粉中黄曲霉毒素B1含量测量的不确定度。方法依据《化学分析中的不确定度的评估指南》(CNAS-GL06),对HPLC法测定玉米粉中黄曲霉毒素B1含量进行不确定度分析。结果玉米粉中黄曲霉毒素B1含量测定扩展不确定为10.05%,样品含量为(2.59±0.26)μg/kg,影响含量测定的最主要影响因素为标准曲线的拟合及方法的提取回收率。结论本研究建立了简便易行的玉米粉中黄曲霉毒素B1含量检测结果的不确定度评定方法。     

玉米肽糙米胚芽片对酒精性肝损伤保护作用的实验研究

目的研究玉米肽糙米胚芽片对酒精性肝损伤的保护作用。方法采用无水乙醇诱导大鼠酒精性肝损伤模型,实验设低、中、高3个剂量组,其玉米肽糙米胚芽片剂量分别为400、1 200、2 400 mg/（kg.bw）,另设蒸馏水阴性对照组和乙醇模型对照组,每组10只SD大鼠。分别给大鼠连续经口灌胃45 d后进行肝匀浆中丙二醛（MDA）、还原型谷胱甘肽（GSH）、甘油三酯（TG）测定及肝脏组织病理学检查,观察玉米肽糙米胚芽片对酒精性肝损伤的保护作用。结果与模型对照组相比,玉米肽糙米胚芽片中、高剂量组能升高大鼠肝匀浆GSH含量（均P〈0.05）,高剂量组能降低大鼠肝匀浆TG含量（P〈0.05）和减轻肝细胞脂肪变性（P〈0.05）。结论玉米肽糙米胚芽片对酒精性肝损伤具有保护作用。     

Overview on zein protein: a promising pharmaceutical excipient in drug delivery systems and tissue engineering

Introduction: Natural pharmaceutical excipients have been applied extensively in the past decades owing to their safety and biocompatibility. Zein, a natural protein of plant origin offers great benefit over other synthetic polymers used in controlled drug and biomedical delivery systems. It was used in a variety of medical fields including pharmaceutical and biomedical drug targeting, vaccine, tissue engineering, and gene delivery. Being biodegradable and biocompatible, the current review focuses on the history and the medical application of zein as an attractive still promising biopolymer.

Areas covered: The current review gives a broadscope on zein as a still promising protein excipient in different fields. Zein- based drug and biomedical delivery systems are discussed with special focus on current and potential application in controlled drug delivery systems, and tissue engineering.

Expert opinion: Zein as a protein of natural origin can still be considered a promising polymer in the field of drug delivery systems as well as in tissue engineering. Although different researchers spotted light on zein application in different industrial fields extensively, the feasibility of its use in the field of drug delivery replenished by investigators in recent years has not yet been fully approached.     

A comparison of total inward leakage measured using sodium chloride (NaCl) and corn oil aerosol methods for air-purifying respirators

The International Organization for Standardization (ISO) standard 16900-1:2014 specifies the use of sodium chloride (NaCl) and corn oil aerosols, and sulfur hexafluoride gas for measuring total inward leakage (TIL). However, a comparison of TIL between different agents is lacking. The objective of this study was to measure and compare TIL for respirators using corn oil and NaCl aerosols. TIL was measured with 10 subjects donning two models of filtering facepiece respirators (FFRs) including FFP1, N95, P100, and elastomeric half-mask respirators (ERs) in NaCl and corn oil aerosol test chambers, using continuous sampling methods. After fit testing with a PortaCount (TSI, Inc., St. Paul, MN) using the Occupational Safety and Health Administration (OSHA) protocol, five subjects were tested in the NaCl chamber first and then in the corn oil chamber, while other subjects tested in the reverse order. TIL was measured as a ratio of mass-based aerosol concentrations in-mask to the test chamber, while the subjects performed ISO 16900-1-defined exercises. The concentration of NaCl aerosol was measured using two flame photometers, and corn oil aerosol was measured with one light scattering photometer. The same instruments were used to measure filter penetration in both chambers using a Plexiglas setup. The size distribution of aerosols was determined using a scanning mobility particle sizer and charge was measured with an electrometer. Filter efficiency was measured using an 8130 Automated Filter Tester (TSI). Results showed the geometric mean TIL for corn oil aerosol for one model each of all respirator categories, except P100, were significantly (p?相似文献   

单纯高胆固醇或其合并玉米油饮食建立兔动脉粥样硬化模型的比较

 目的：比较单纯胆固醇饮食与胆固醇合并玉米油饮食用于建立兔动脉粥样硬化模型的可靠性及其所形成斑块面积的大小,为兔动脉粥样硬化模型的建立方法提供基本数据。方法：新西兰兔18只,随机分为3组（每组6只）,即普通饲料组（C组）、单纯高胆固醇饲料组（H1组）和高胆固醇玉米油饲料组（H2组）。实验开始前至第12周,每周末称动物体重。分别于实验开始前、第12周末时检测血清高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、总胆固醇(TC)和甘油三酯(TG) 浓度。12周末将动物麻醉后,从主动脉根部起取胸主动脉8 cm行脂肪染色,观察是否存在动脉粥样硬化斑块,并测定斑块面积（PA）占主动脉内膜面积（IA）百分比（PA/IA）。结果：实验第12周末,H1组和H2组的HDL-C、LDL-C和TC水平均高于C组（P<0.05）,H2组TG高于C组（P<0.05）;H2组HDL-C水平高于H1组（P<0.05）,但2组间LDL-C、TC及TG水平无显著差异（P>0.05）。C组无动脉粥样硬化斑块形成,H1组和H2组兔均有动脉粥样硬化斑块,造模成功率为100%。H1组及H2组PA/IA分别为（49.74±18.78）%和（56.95±26.74）%,2组间无显著差异（P>0.05）,但与C组相比均有显著差异（P<0.05）。结论：单纯高胆固醇饮食或高胆固醇加玉米油饮食均能成功建立兔动脉粥样硬化模型,饲养12周的建模成功率均为100%,且2种方法对形成斑块的面积无明显影响。     

玉米苞叶煎剂对动脉粥样硬化家兔血清内皮素、前列环素及病理形态学影响

为研究玉米苞叶对动脉粥样硬化的治疗作用 ,通过建立高脂食饵性兔动脉粥样硬化模型 ,观察了玉米苞叶煎剂治疗用药后对血清内皮素、6 酮 前列腺素及主动脉粥样硬化病理形态学的影响。结果发现 ,模型组血清内皮素和 6 酮 前列腺素较对照组均明显降低 ,每日饲饮含硅量 2mg (kg·d)玉米苞叶煎剂 10 0mL 只 (低剂量组 )或含硅量 4mg (kg·d)玉米苞叶煎剂 10 0mL 只 (高剂量组 )。于实验 17周末发现 ,血清内皮素较模型组有所上升 ,6 酮 前列腺素F1а较模型组明显升高 (模型组为 6 6± 2 6 ,低剂量组为 12 2 .4± 2 .4 ,高剂量组为 117± 6 4 ,P <0 .0 5 ) ,内皮素与前列环素比值也明显降低 (模型组为 7.0± 1.2 ,低剂量组为 5 .1± 1.4 ,高剂量组为 5 .7± 1.3,P <0 .0 5 ) ,主动脉内膜粥样斑块病变程度和面积较模型组明显减轻和缩小。结果提示 ,玉米苞叶煎剂具有保护动脉内膜损伤 ,调节内皮细胞血管活性物质分泌 ,治疗家兔动脉粥样硬化作用     

玉米苞叶对动脉粥样硬化家兔血管平滑肌细胞凋亡及Bcl-2和p53蛋白表达的影响

目的探讨玉米苞叶煎剂对实验性动脉粥样硬化(AS)家兔血管平滑肌细胞(VSMCs)凋亡及凋亡相关基因Bcl-2和p53蛋白表达的影响。方法选用大耳白家兔,利用高脂饲料复制家兔动AS模型,随机分为模型组、玉米苞叶煎剂组和正常对照组。实验9 w后确认两组动物造模成功,其中一组给予玉米苞叶煎剂治疗,28 m l/kg.d-1(玉米苞叶1.4 g/m l),实验17 w后,处死家兔,观察主动脉内膜的病理形态学改变,采用流式细胞术检测VSMCs凋亡率以及凋亡相关基因Bcl-2和p53蛋白表达。结果模型组VSMCs凋亡率明显高于对照组(P<0.05),p53和Bcl-2蛋白表达均增强(P<0.05),肉眼观察,主动脉内膜出现典型的AS斑块,动脉管腔极度狭窄。玉米苞叶煎剂组VSMCs凋亡率明显降低(P<0.05);p53和Bcl-2蛋白表达均下调(P<0.05);主动脉斑块面积较模型组明显减小,动脉管腔狭窄减轻。结论玉米苞叶通过影响p53和Bcl-2蛋白表达而影响AS家兔VSMCs凋亡;同时缩小AS斑块面积,具有显著治疗家兔AS作用。     

Report of an Expert Panel on the reanalysis by of a 90-day study conducted by Monsanto in support of the safety of a genetically modified corn variety (MON 863).

MON 863, a genetically engineered corn variety that contains the gene for modified Bacillus thuringiensis Cry3Bb1 protein to protect against corn rootworm, was tested in a 90-day toxicity study as part of the process to gain regulatory approval. This study was reanalyzed by Séralini et al. who contended that the study showed possible hepatorenal effects of MON 863. An Expert Panel was convened to assess the original study results as analyzed by the Monsanto Company and the reanalysis conducted by Séralini et al. The Expert Panel concludes that the Séralini et al. reanalysis provided no evidence to indicate that MON 863 was associated with adverse effects in the 90-day rat study. In each case, statistical findings reported by both Monsanto and Séralini et al. were considered to be unrelated to treatment or of no biological or clinical importance because they failed to demonstrate a dose-response relationship, reproducibility over time, association with other relevant changes (e.g., histopathology), occurrence in both sexes, difference outside the normal range of variation, or biological plausibility with respect to cause-and-effect. The Séralini et al. reanalysis does not advance any new scientific data to indicate that MON 863 caused adverse effects in the 90-day rat study.     

An Improved Tissue-Mimicking Polyacrylamide Hydrogel Phantom for Visualizing Thermal Lesions with High-Intensity Focused Ultrasound

A recipe was created to improve the tissue-mimicking (TM) bovine serum albumin (BSA) polyacrylamide hydrogel (PAG) reported in our previous study (Choi MJ, Guntur SR, Lee KI, Paeng DG, Coleman AJ. Ultrasound Med Biol 2013; 29:439–448). In that work, the concentration of acrylamide in TM BSA PAG was increased to make its attenuation coefficient the same as that of a tissue. However, this increase made the PAG stiffer and less homogeneous. In addition, the increase in acrylamide caused a significant increase in temperature over the denaturation threshold of BSA during polymerization, which required forced cooling so that the PAG did not become opaque at room temperature after polymerization. To eliminate those shortcomings, we substituted the increased acrylamide with a viscous polysaccharide liquid (corn syrup). The concentration of corn syrup was optimized to 20% (w/v, tested in the volume of 50 mL), so that the acoustic properties of the PAG would be close to those of human liver. The improved TM (iTM) BSA PAG constructed in this study had a speed of sound of 1588 ± 9 m/s, an attenuation coefficient of 0.51 ± 0.06 dB cm^?1 at 1 MHz and a backscattering coefficient of 0.22 ± 0.09 × 10^?3 sr^?1 cm^?1 MHz^?1. The density and acoustic impedance were 1057 kg/m³ and 1.68 MRayl, respectively, and the non-linear parameter (B/A) was 5.9 ± 0.3. The thermal, optical and mechanical properties were almost the same as those of the BSA PAG (Lafon et al.2005). Experimental verification indicated that the thermal lesions visualized in the proposed iTM BSA PAG by high-intensity focused ultrasound were highly reproducible. In conclusion, iTM BSA PAG was proven to eliminate TM BSA PAG shortcomings effectively and is expected to be a promising test phantom for clinical high-intensity focused ultrasound device.