大豆异黄酮的测定方法研究

目的:检测大豆及其制品中黄豆甙、大黄豆甙、染料木甙、黄豆甙元、大黄豆素和金雀异黄素,建立大豆及其制品中6种大豆异黄酮的高效液相色谱-二极管阵列检测器(HPLC-PDA)检测方法。方法:保健食品、豆腐等样品中的大豆异黄酮直接用甲醇水(80+20,v/v)超声提取30 m in,定容过0.45μm滤膜后测定;豆粉和豆奶粉等样品中的大豆异黄酮及其酯类用甲醇水(80+20,v/v)超声提取,提取液经碱性皂化,将某些酯类转化成对应的大豆异黄酮,经盐酸中和,甲醇水(80+20,v/v)定容,过滤膜后测定;酱油和豆豉等样品超声提取30 m in,提取液经OASIS HLB柱去杂质,过0.45μm滤膜,进行液相色谱分析。样品中的6种大豆异黄酮用甲醇和醋酸铵(0.025 mol/L,pH 4.1)作流动相,流速2.0 m l/m in进行梯度洗脱,经250×4.6 mm粒径10μm C18柱分离,二极管阵列检测器(210~400 nm)测定。30 m in内6种大豆异黄酮可得到良好分离。结果:测定6种大豆异黄酮的平均加标回收率在86.7%~116%,加标回收相对标准偏差均小于8%,最底检出限量小于0.04μg。结论:本方法适用于大豆及其制品中大豆异黄酮的测定。     

快速溶剂萃取-液相色谱法测定食品中大豆异黄酮的含量

目的建立一种同时测定食品中6种大豆异黄酮[大豆苷元(daidzein)、黄豆黄素(glycitein)、染料木素(genistein)、黄豆黄苷(glycitin)、大豆苷(daidzin)和染料木苷(genistin)]的快速溶剂萃取-高效液相色谱检测方法。方法样品经快速溶剂萃取仪萃取,采用phenomenex LunaC18柱,以0.05%三氟乙酸(TFA)溶液和乙腈为流动相梯度洗脱,二极管阵列检测器检测。结果连续7次测定6种大豆异黄酮,相对标准偏差为1.4%～5.9%。加标回收率82%～112%。在0.01～10μg/ml范围内线性关系良好、最低检出限10μg/kg。结论该方法操作简便,萃取液共存物质对测定方法干扰较小,仪器测定方法准确。适用于大豆异黄酮的检测。     

高效液相色谱法测定保健食品中大豆异黄酮含量的方法改进

目的建立以改进的高效液相色谱法测定保健食品中大豆异黄酮含量的方法。方法固体样品经70%乙醇超生提取30 min,过滤膜后进行液相色谱测定,液体样品过滤后直接进行液相色谱测定。色谱柱：Agilent ZORB-AX SB-C18（250 mm×4.6 mm,5μm）;流动相：甲醇和1%磷酸水溶液梯度洗脱;流速：1.0 ml/min;柱温：30℃;二极管阵列检测器,定量波长254 nm。结果大豆苷、大豆黄素、染料木苷、大豆素、大豆黄苷、染料木素6种组分的回收率在97.5%～105.0%之间,RSD在0.46%～3.33%之间,6种组分检出限分别为0.60、0.57、0.26、0.28、0.55、0.27μg/ml。结论该方法简便、快速、重现性好。     

保健食品中红景天甙的提取和测定方法研究

〔目的〕建立保健食品中红景天甙样品的前处理和高效液相色谱检测方法。〔方法〕保健食品中的红景天甙经 70 %乙醇超声波提取 ,聚酰胺柱净化后 ,以甲醇 -0 .0 1mol LNH4 Ac为流动相 ( 2 0∶80 ) ,用C1 8柱 ,紫外 2 15nm检测。〔结果〕优化了含红景天保健食品中红景天甙的提取、净化和测定条件 ,有效去除样品中的干扰成分 ,定量检测红景天甙。方法检出限为 0 .5 μg ml,样品测定的相对标准差 (RSD)小于 2 .5 % ,加标回收率为 97.1% -10 2 .4%。〔结论〕本方法操作简便 ,灵敏、可靠 ,适用于红景天原料和保健食品中红景天甙的分析测定。     

快速同时检测大豆异黄酮保健食品中三种雌激素的HPLC法

〔目的〕研究检测大豆异黄酮类保健食品中三种雌激素 (雌二醇、雌酮、己烯雌酚 )含量的分析法。〔方法〕采用HypersilODS2C18色谱柱 (2 5 0mm× 4.6mmID ,5 μm) ,流动相甲醇 -水 (体积比 5 3 :47) ,流速 1.0mL/min ,检测波长 2 80nm等作为色谱条件 ,同时检测三种雌激素。〔结果〕该方法的线性范围在 0 .5～ 2 5 0mg/L ,相关系数r在 0 .998以上 ,相对标准偏差 (RSD)为 0 .9%～ 1.8% ,回收率在 91.3 %～ 98.3 %以上。〔结论〕该法具有快速、准确、灵敏等优点 ,适合大豆异黄酮中雌激素的检测     

大豆异黄酮与心血管疾病关系的研究进展

近年来研究表明 ,在以大豆为主食的东方 ,人群心血管疾病的患病率明显低于西方〔1〕,这在一定程度上说明大豆和豆制品具有预防心血管疾病的生物功效 ,有研究报道这些功效均与大豆中的异黄酮成分密切相关。本文就大豆异黄酮的化学组成和结构及与心血管疾病关系进行综述。1　大豆异黄酮的化学组成和结构大豆异黄酮是大豆生长过程中形成的一类次生代谢产物 ,主要存在于大豆种子的子叶和胚轴中 〔2〕。目前发现大豆中异黄酮共有 12种 ,分为游离型甙元 (3种 )和结合型糖甙 (9种 )。甙元约占总量的 2 %～ 3% ,包括染料木素 (也称金雀异黄素 ,三羟…     

高效液相色谱法测定保健食品中大豆异黄酮

目的：建立测定保健食品中大豆异黄酮含量的高效液相色谱法。方法：通过对流动相的优选，以甲醇：水=3：2为流动相，使染料木素、大豆苷元、大豆甙、染料木甙4种大豆异黄酮主要成分达到较好的分离效果，可分别测定4种成分含量及以此4种成分为主要成分的保健食品中大豆异黄酮含量。结果：方法的最低检出浓度分别为大豆甙1．9μg／ml、染料木甙1．2μg／ml、大豆苷元1．0μg／ml、染料木素0．8μg／ml；标准曲线线性范围分别为1．9—100μg／ml、1．2—100μg／ml、1．0—170μg／ml、0．8～140μg／ml；方法平均回收率分别为99．1％、98．5％、97．5％、98．8％；相对标准偏差均（10％。结论：建立的方法可准确、快速的测定大豆异黄酮的含量。     

异黄酮对PC-3细胞凋亡的诱导作用

目的 :　通过观察染料木素 (genistein,GS)、大豆甙元 (daidzein,DA)和黄豆黄素(glycitein,GL)对前列腺癌细胞 (PC- 3 )凋亡的影响 ,探讨通过膳食途径预防前列腺癌发生危险性的可行性。方法 :　将 PC- 3细胞在 RPMI1 6 4 0培养液 (含 1 0 %小牛血清 )中采用开放式单层贴壁培养。实验设溶剂对照及三种受试物各三个剂量组 ,采用流式细胞术 ,DNA凋亡片段凝胶电泳和细胞 HE染色法分析三种常见异黄酮类物质对 PC- 3细胞凋亡的影响。结果 :　与对照组相比 ,流式细胞仪分析结果表明 ,5 0μ mol/L GS、75μ mol/L DA和 75μ mol/L GL对 PC- 3细胞处理 72 h,二倍体细胞 (G1期细胞 )相对减少 ,亚二倍体细胞峰 (即细胞凋亡率 )逐渐增多 ,即凋亡细胞比例逐渐增多 ;DNA凋亡片段凝胶电泳和细胞苏木素染色结果也显示 ,三种受试物能够诱导 PC- 3细胞凋亡 ,且这种作用存在剂量 -效应关系。结论 :　异黄酮类化合物染料木素、大豆甙元和黄豆黄素均具有诱导 PC- 3细胞凋亡的作用 ,这一结果提示 ,该类物质是可通过诱导细胞凋亡而发挥其抗肿瘤作用的。     

大豆异黄酮抗癌防癌机制研究进展

<正>大豆异黄酮(soybean isoflavones,SI)是大豆中一类重要的非营养素成分,包括大豆素(daidzein)、染料木素(genistein)和黄豆黄素(glycitein)。大豆异黄酮具有多种生物活性,如雌激素样作用、抗雌激素样作用、抗氧化和调节细胞周期等作用〔1〕,因其具有显著的防癌抗癌效果而倍受关注。本研究将近期有关大豆异黄酮抗癌防癌机制方面的研究作一综述。     

HPLC法测定肉中五种磺胺兽药残留量及其不确定度评估

〔目的〕建立肉中 5种磺胺兽药残留量测定方法。〔方法〕采用高效液相色谱 (HPLC)梯度洗脱法同时测定肉中磺胺嘧啶、磺胺二甲嘧啶、磺胺 - 5 -甲氧嘧啶、磺胺二甲氧嘧啶、磺胺喹恶啉残留量。使用Capcell-pakC18柱 (SHISEI DO) ,以乙腈和 1% (V/V)乙酸溶液为流动相 ,使用紫外检测器 ,在 2 70nm处对样品中 5种磺胺兽药进行检测。〔结果〕磺胺嘧啶、磺胺二甲嘧啶、磺胺 - 5 -甲氧嘧啶、磺胺二甲氧嘧啶、磺胺喹恶啉分别在 0 196 μg/ml～ 1 96 4 μg/ml,0 199μg/ml～1 992 μg/ml,0 2 2 0 μg/ml～ 2 2 0 4 μg/ml,0 188μg/ml～ 1 884 μg/ml,0 2 0 4 μg/ml～ 2 0 36 μg/ml范围内有良好的线性关系 ,其线性相关系数分别为r=0 9989,r=0 9990 ,r=0 9993,r=0 9993和r=0 9991;回收率在 72 2 3%～ 93 75 %。〔结论〕该方法专属性强、灵敏可靠、重现性好。     

Calcium intake in the elderly: validation of a dietary questionnaire

Epidemiological studies of calcium and osteoporosis have been hampered by the lack of a suitable tool for assessing calcium intake. This report describes a new frequency and amount questionnaire for measuring present and past calcium intake in the elderly. The validity of the questionnaire was tested against two commonly used standards of dietary assessment, five-day duplicate diets and seven-day weighed dietary inventories. The resulting correlation coefficients were, respectively, r = 0.76 and r = 0.69, while that for repeatability was r = 0.84. Furthermore, the questionnaire categorized subjects into thirds of the distribution of intake with almost no gross misclassification. It is suggested that the present findings may be extended to the majority of normal, healthy elderly subjects, implying wide application for the questionnaire in the assessment of calcium intake in the elderly.     

The occurrence of antimicrobial substances in toilet,sink and shower drainpipes of clinical units: A neglected source of antibiotic residues

Antibiotics represent one of the most important drug groups used in the management of bacterial infections in humans and animals. Due to the increasing problem of antibiotic resistance, assurance of the antibacterial effectiveness of these substances has moved into the focus of public health. The reduction in antibiotic residues in wastewater and the environment may play a decisive role in the development of increasing rates of antibiotic resistance. The present study examines the wastewater of 31 patient rooms of various German clinics for possible residues of antibiotics, as well as the wastewater of five private households as a reference.To the best of our knowledge, this study shows for the first time that in hospitals with high antibiotic consumption rates, residues of these drugs can be regularly detected in toilets, sink siphons and shower drains at concentrations ranging from 0.02?μg·L^?1 to a maximum of 79?mg·L^?1. After complete flushing of the wastewater siphons, antibiotics are no longer detectable, but after temporal stagnation, the concentration of the active substances in the water phases of respective siphons increases again, suggesting that antibiotics persist through the washing process in biofilms. This study demonstrates that clinical wastewater systems offer further possibilities for the optimization of antibiotic resistance surveillance.     

Self-reported health problems among Swedish miners one year after unemployment

Unemployment is considered to be a public health concern sincedeterioration in the health of the unemployed is often anticipated.However, for some groups, such as miners, unemployment mightimprove health due to a cessation of potentially harmful occupationalexposures. This study evaluates the health of 79 miners in oneSwedish iron-ore mine, and 226 age-matched controls from thegeneral population, during one year after the closure of themine. The participants received a questionnaire regarding medicalhistory and subjective symptoms at the beginning of the studyperiod, and after one year. Statistically significant negativeeffects on self-reported health attributable to unemploymentwere not found, although neuropsychiatric symptoms were morecommon among the unemployed miners. The miners reported a statisticallysignificant improvement in grip force (p=0.031). They had asignificantly higher prevalence of symptoms associated withmining related exposures when compared with the population controls;pain in the upper extremities [relative risk (RR)=2.27, 95%confidence interval (Cl)=1.44–3.59), back pain (RR=1.84;Cl=1.237–2.75), vasospastic disease of the fingers (RR=2.05;Cl=1.18–3.57) and obstructive respiratory symptoms (attacksof dyspnea and wheezing: RR=3.67; Cl=1.167–11.6).     

Excès de cas humains et animaux de tularémie en France au cours de l’hiver 2007–2008 : émergence ou phénomène isolé ?

Context

Tularemia is a zoonosis affecting humans and hares in France. We describe the results of surveillance in both species, in 2007 and 2008.

Methods

Human tularemia cases are mandatorily notifiable in France since 2003. In hares, surveillance relies on volunteer hunter associations in all districts of the country. Data from mandatory reports and volunteer surveillance in 2007/2008 were analyzed and compared with previous results.

Results

In 2007/2008, 144 cases were reported in humans and 117 cases in hares. This was a 100% increase compared to previous years. Human cases differed from those of previous years only by the frequency of contact with breeding animals. Human cases without any documented risk exposure were also more frequent.

Conclusion

An increase of tularemia cases occurred in 2007/2008 in both species. Complementary studies are needed to identify the species reservoir in France to understand the causes of this peak of cases.     

Occupational health hazards in mining: an overview

This review article outlines the physical, chemical, biological, ergonomic and psychosocial occupational health hazards of mining and associated metallurgical processes. Mining remains an important industrial sector in many parts of the world and although substantial progress has been made in the control of occupational health hazards, there remains room for further risk reduction. This applies particularly to traumatic injury hazards, ergonomic hazards and noise. Vigilance is also required to ensure exposures to coal dust and crystalline silica remain effectively controlled.     

深圳公立医院管理体制改革制度设计

深圳公立医院管理体制改革实行政事分开、管办分开,在理事会架构下按法定机构模式组建市医管中心,落实公立医院运营管理自主权.作者从当前公立医院管理体制的弊端入手,介绍了深圳市进行公立医院管理体制改革的基本思路及改革方案设计的主要举措,深入剖析了的改革方案的特点,并对改革效果进行了预测.     

Manufacture and use of nanomaterials: current status in the UK and global trends

This paper provides an overview of the production and use of nanomaterials (NMs), particularly in the UK. Currently, relatively few companies in the UK are identifiable as NM manufacturers, the main emphasis being the bulk markets in metals and metal oxides, and some niche markets such as carbon nanotubes and quantum dots. NM manufacturing in the UK does not reflect the global emphasis on fullerenes, nanotubes and fibres. Some assumptions have been made about the types of NM that are likely to be imported into the UK, which currently include fullerenes, modified fullerenes and other carbon-based NMs including nanotubes. Many university departments, spin-offs and private companies have developed processes for the manufacture of NMs but may only be producing small quantities for research and development (R&D) purposes. However, some have the potential to scale up to produce large quantities. The nanotechnology industry in the UK has strong R&D backup from universities and related institutions. This review has covered R&D trends at such institutions, and appropriate information has been added to a searchable database. While several companies are including NMs in their products, only a few (e.g. manufacturers of paints, coatings, cosmetics, catalysts, polymer composites) are using nanoparticles (NPs) in any significant quantities. However, this situation is likely to change rapidly. There is a need to collect more information about exposure to NPs in both manufacturing and user scenarios. As the market grows, and as manufacturers switch from the micro- to the nanoscale, the potential for exposure will increase. More research is required to quantify any risks to workers and consumers.     

Effects of nitrogen dioxide on red blood cells of rats: Changes in components of red cell membranes during in vivo exposure to NO2

Red cell membranes, prepared from red blood cells of rats exposed to 4, 10, or 20 ppm nitrogen dioxide (NO₂) for 1 to 10 days, were examined for evidence of changes in membrane components. Appreciable changes were not found in contents of phospholipid and cholesterol during exposure to 10 ppm NO₂. By contrast, protein content altered with the time of exposure. Moreover, changes in protein composition were observed by employing sodium dodecyl sulfate — polyacrylamide gel electrophoresis. Twenty-four-hour exposure to NO₂ at the concentration above 10 ppm resulted in a marked increase in the percentage of lysophosphatidylethanolamine (LysoPE) to the total phospholipids. The prolonged exposure to 10 ppm NO₂ gave rise to a further increase in LysoPE, whereas the percentage of phosphatidylethanolamine (PE) showed a gradual decrease. A 1-day exposure to 4.0 ppm NO₂ also caused an increase in sialic acid content and decreases in those of PE and hexose. In addition to contents of these components the percentage of LysoPE increased 5 days after exposure and the elevated values were maintained up to the end of exposure period. These results demonstrate that red blood cells in circulation exhibit different membrane properties in terms of lipid and carbohydrate composition during 10 days of exposure to 4.0 ppm NO₂.     

Investigating clusters in the workplace and beyond

Clusters of disease are common and occur in the workplace and in the general community. They often arouse considerable concern among the population. Investigations have sometimes lead to exciting new knowledge, but in general the investigation of clusters is difficult and often unrewarding, especially for community clusters. In the workplace, investigations are more likely to find associations and even new causes, but still many clusters remain enigmatic. Despite this, there are many reasons for investigating clusters, including allaying community concern and identifying uncontrolled exposures. A structure for investigating clusters in the workplace is suggested.