采用同位素示踪技术对头发中微量元素测定预处理方法的研究

目的：通过评价目前常用的4种头发预处理方法对头发中铅，镉，铬和汞元素含量的影响，探讨发样预处理方法的适用条件。方法：用丙酮－水（IAEA法），海鸥洗涤剂，Na2EDTA溶液和稀硝酸溶液对未经沾污和经过放射性同位素沾污的头发进行洗涤，比较头发中铅，镉，铬和汞元素含量及头发pH值对元素含量的影响。结果：丙酮－水（IAEA法）及海鸥洗涤剂对头发中内，外源性的上述4种元素的洗脱量较小；Na2EDTA和硝酸溶液对头发中的元素具有较强的洗脱能力，并对内源性元素也有一定程度的洗脱。结论：当外源性污染不是很严重以致可以忽略不计时，IAEA法与海鸥洗涤剂都可以作为头发中这4种元素分析的预处理方法。当外源性沾污的程度高，上述两种方法不能有效地清洗污染的发样；Na2EDTA和稀硝酸溶液由于对头发中内，外源性的元素都具有较强的洗脱能力，所以不宜作为头发中元素分析的预处理方法。     

毛发铅、镉含量作为不同年龄大鼠机体负荷的指征

一些学者发现毛发的铅、镉含量与对这些金属的接触程度、机体的负荷及临床症状明显相关。由于头发在取样、收集、保存、分析上均较方便,常被视为流行病学调查的理想检材。但是,也有一些学者指出诸如年龄、性别等因素可能对这些金属在毛发中的含量有影响,而使其未能作为一种活检材料得到充分利用。Weis等曾先后注意到儿童头发内有较高的铅、镉含量,但对其是否代表儿童机体内较高的铅、镉负荷,则仍有不同看法。本文作者试图通过有控制的动物实验,观     

产妇毛发、静脉血及胎儿脐血微量元素相关性分析

目的研究必需和非必需微量元素在正常产妇毛发、静脉血及胎儿脐血间的分布规律，探讨胎盘屏障对母体和胎儿间微量元素转运的影响。方法选择60名健康住院分娩的产妇作为研究对象，分别采集每个产妇枕部毛发、静脉血和胎儿脐血，并对产妇日常生活中的洗发频率等因素进行问卷调查。实验室发样洗涤采用国际原子能机构推荐的洗涤程序进行，样品消化利用微波消化的方法，对样品中必需微量元素锌、铜、铬、锰、钴、钼，毒性元素铅、砷、镉、汞，以及稀土元素：镧、镨、钕、钇进行了ICP质谱分析。结果毛发中14种微量元素含量均显著高于静脉血和脐血；相关及偏相关分析均表明，产妇静脉血与胎儿脐血间锌、锰、钴、钼、铅、砷、汞、钇、镧、镨、钕显著正相关；毛发与胎儿脐血间铅、汞呈显著正相关；毛发与静脉血间锰和镉呈显著正相关。结论孕妇体内微量元素水平会直接影响到胎儿，毛发中微量元素含量可反应机体既往一定时期内的平均暴露水平。     

人过中年需补铬

铬是胰岛素不可缺少的辅助成分,参与糖代谢过程,促进脂肪和蛋白质的合成。化验证明,糖尿病人的头发和血液中的含铬量比正常人要低,而且心血管疾病和体内铬的含量低也有关系。 人体在生长发育过程中,体内铬的含量会发生一定的变化。一般来说,从新生儿到10岁的儿童,身体内的铬含量较高,随着年龄增长,人体内的铬含量逐步减少。人过中年之后,若不能及时加以补充,则容易造成血糖增高、血管硬化等多种     

总镉和非蛋白结合镉致大鼠肾脂质过氧化作用的研究

目的：探讨非蛋白结合镉，总镉致肾脂质过氧化的作用。方法 利用染镉动物攻凝胶渗透层析技术，观察非蛋白结合镉，总镉在肾脂质过氧化时的作用。结果 镉染毒组谷胱甘肽过氧化物酶（GSH－Px)，超氧化物歧化酶（SOD）活性逐渐下降，谷胱甘肽（GSH），丙二醛（MDA）含量逐渐增加，总镉，非蛋白结合镉与肾GSH之间存在着明显的正相关关系（r分别为0.898,0.751) ,与肾SOD之间存在着明显的负相关关系（r分别为-0.896,-0.767)，此外总镉还与肾GSH－Px存在着明显的负相关关系（r=-0.756)。结论 总镉，非蛋白结合镉均能引起肾脂质过氧化，但总镉比非蛋白结合镉可能具有更重要的意义。而有关肾GSH升高的机制有待进一步研究。     

“锈”发三宗罪

认识你的秀发。水、蛋白质是人体最主要成分。对毛发而言，蛋白质比水更重要，事实上我们可以概略地说毛发就是蛋白质纤维。导致头发损伤的原因可分为三大类。     

陶瓷容器熬煮酸菜对重金属含量影响

目的探讨酸菜在陶瓷容器中熬煮砷、汞、铅、镉、铬、镍、铜等元素含量的变化。方法以微波消解预处理样品,用电感耦合等离子体质谱法测定熬煮后汤料、酸菜样品中各元素含量。结果用陶瓷容器熬煮酸菜,可使汤料中的汞、铅、镉、铬、铜含量由1.71、22.10、6.10、40.05、128.00μg/L增至3.76、26.75、8.20、53.50、183.75μg/L,分别增加约220%、21%、13%、34%和44%;可使酸菜中的汞、铅、镉、铬、铜含量由35.34、397.96、20.35、213.12、1 070μg/kg增至78.75、460.39、23.02、387.31、2 100μg/kg,分别增加约222%、17%、34%、81%和96%。结论酸菜在陶瓷容器内熬煮,锅体有较多汞、铬、铜和微量铅、镉溶出,基本无砷、镍溶出。     

126例癫痫患者头发9种元素含量测定分析

１２６例癫痫患者头发９种元素含量测定分析周清潮，王国平，夏峰自１９９２年７月─１９９２年１２月，就我院病房、门诊１２６例癫痫患者的头发微量元素铜、铁、硒、锌、镁、锂、铬、镉、钛进行测定如下。一般资料：１２６例癫痫患者经ＥＥＧ、ＣＴ及其它检查方法，确诊...     

镉应答癌基因蛋白对细胞原癌基因表达的影响

目的探讨镉应答癌基因蛋白(TEF-1δ编码蛋白)对多种不同细胞肿瘤相关基因表达的影响，以阐明镉的分子致癌机制。方法应用TEF-1δ基因真核细胞稳定表达系统和Western blot检测技术，用各种单克隆抗体检测细胞肿瘤相关基因蛋白的表达情况。结果相对于载体转染中国地鼠卵巢细胞(CHO)对照细胞，在4株具有高效稳定表达TEF-1δ编码蛋白质的CHO细胞系中均有细胞原癌基因C-fos高表达，其编码蛋白(55kDa)含量均明显高于对照组。同样，4株高效稳定表达TEF-1δ编码蛋白质的CHO系均具有相对较高的细胞周期调控基因Cyclln D1(编码蛋白36kDa)的表达。其余肿瘤相关基因蛋白如pan-ras，c-myc，c-jun，MDM2，ODC，p16，p53的表达在TEF-1δ转基因细胞与对照细胞之间未见明显差别。结论镉应答原癌基因TEF-1δ的超额表达可调高细胞原癌基因c-fos和细胞周期调控基因Cyclin Dl的表达，这可能是镉应答原癌基因TEF-1δ的分子致癌机制。     

筛查掺假蛋白的研究

有暴利的驱动，市场就不断会有造假产生，目前国内外一些不法分子利用蛋白检测技术和标准的缺失，在食品及饲料中掺入普通方法不易检测出的假蛋白。尤其严重的是一些唯利是图的人也将化工原料“三聚氰胺”掺入食品中获取暴利，造成的影响十分恶劣，因此，必须加强对掺假蛋白检验方法的研究。传统的蛋白质含量测定是使用测定氮的总量间接计算蛋白质含量。由于该方法无法确定样品是否掺入了假蛋白，因此，蛋白质含量的测定必须结合GC／MS、HPLC、LC／MS等方法来筛查假蛋白种类，但是假蛋白种类的多样性决定了这种检测流程时间较长，并且会产生很高的检测费用。最新的iTAG蛋白标签技术可以有针对性的测定样品中“氨基酸氨基组分”，从而确定真蛋白质的含量。应用iTAG技术还可以大大简化蛋白质检测过程，节约大量制样和检测时间并降低检验费。因此，它既是一种切实可行的真蛋白快速检测方法，也是一种假蛋白的快速筛查方法。     

Adsorption and Elution of Cadmium on Hair

Adsorption and elution of cadmium on human and mouse hair were studied by the use of radioactive isotope technique. Hair with Cd accumulated solely from the hair follicle was obtained from mice injected with cadmium 109. Cadmium adsorption on human hair, when brought into contact with a solution of cadmium chloride tagged with cadmium 109 occurred with an individual variation, ranging from 0 to 100% of Cd present in the solution. This variation seemed to have been the result of individual variation in hair acidity. A nearly complete removal of Cd from the hair could be obtained by using a sufficiently strong solution of an acid. However, the different treatments applied were not effective for separate analysis of exogenous and endogenous hair Cd.     

Significance of elemental analysis of hair as a means of detecting environmental pollution

The correlation of metal concentrations in hair with those in the critical organs was investigated by tracer studies using 51Cr, 203Hg, 75Se, 109Cd, and 65Zn in mice. The accumulation of these elements in organs of the mouse (including hair) during acute contamination was confirmed. Chronic studies to observe stable zinc and cadmium concentrations in various organs of the mouse at different ages manifested clear differences between zinc and cadmium accumulation patterns. The tracer study data on metal concentrations in 11 organs and those obtained by chemical analysis were compared. In the case of zinc, the correlation between the two is high, irrespective of the age of the mice; for cadmium no correlation was present in young mice but a correlation was seen in mice at ages of 19 weeks or more. Thus, the age-dependent variation of metals in organs is another factor that has been considered. Values for concentrations of several metals in critical organs and hair were compiled from the literature and compared. These studies led to the following conclusions: Hair is a reasonable indicator of mercury and chromium contamination, as these elements are readily deposited into hair and stay a comparatively long time. The time-dependent shifts of zinc and selenium in hair reflected their kinetics in the whole body, though their concentrations in hair were not higher than those in other organs. Hair was found to be a poor indicator of cadmium contamination, as the concentration of cadmium in hair was not parallel to that in the critical organs of the same mouse.     

Lower efficiency of DTPA in reducing cadmium retention in suckling rats

The influence of age on the effectiveness of chelation therapy in enhancing cadmium elimination was studied in 1-, 2-, 8-, and 26-week-old rats. 115mCd was administered intraperitoneally, followed immediately and after 24 hr by an intraperitoneal injection of trisodium calcium diethylenetriaminepentaacetate (DTPA) (600 mumole/kg body wt). The whole body retention determined on the second, fourth, and sixth days of the experiment showed that DTPA greatly decreased cadmium retention in all age groups being about four times more effective in older than younger animals. Determination of 115mCd retention in the gut and organs also revealed that effectiveness of DTPA was lowest for the youngest age group and increased with increasing age. This effect of DTPA was more pronounced in the liver than in the kidney and brain in all age groups. These results indicate that age greatly influences chelation of cadmium and that age might be an important factor in chelation therapy in general.     

Lead and cadmium in hair as an indicator of body burden in rats of different age

Summary The purpose of this work was to evaluate whether hair values of lead and cadmium can be used as an indicator of the body burden of these metals in different age groups.The experiments were performed on rats aged 2 and 18 weeks, which received²⁰³pb and^115mcd by intraperitoneal injection. The whole body retention and the retention of these radioisotopes in the hair (including the skin) was determined 7 days later. Younger animals showed a higher retention in the whole body and hair of radioactive lead and cadmium. The hair values when expressed as the percentage of the whole body retention were for²⁰³pb the same in young and adult rats but for^115mcd they were 2 to 3 times higher in young animals than in adults. It is concluded that lead hair values are a good indicator of the total body burden in both age groups. However, the cadmium body burden of young animals would be greatly overestimated if based on hair values only. This findings might be relevant for interpreting results of hair concentrations of lead and cadmium in children.     

Removal of cadmium ions during stationary growth phase by an extremely cadmium-resistant strain of Stenotrophomonas sp

Stenotrophomonas sp. CD02 was isolated from a site that previously had been contaminated with high concentrations of the heavy metals cadmium (3 mg kg(-1)) and chromium (115 mg kg(-1)). This strain was able to grow on complex (Luria Bertani) medium containing high concentrations of cadmium ion (up to 4 mM). Additionally, it could remove up to 80% of the dissolved ions but only after reaching stationary growth phase. Strain CD02 also tolerated high concentrations of other heavy metals such as chromium, zinc, copper, nickel, and lead at levels more than 2 mM. Although strain CD02 can tolerate much higher cadmium concentrations than the three Stenotrophomonas maltophilia strains tested, they all possess resistance to the same range of antibiotics. This suggests that strain CD02 possesses a mechanism that allows it to tolerate and remove cadmium differently from those conferring resistance to antibiotics. Strain CD02 can be a suitable candidate for heavy metal bioremediation in contaminated environment because it is able to tolerate high concentration of heavy metals and remove cadmium aerobically.     

Microelement composition of the hair of workers in the ceramic paint industry

By means of atomic absorption spectrophotometry, the neutron-activation analysis and chemicospectral procedure the content of 33 trace elements in the hair samples of 48 workers of various professions at the shop of ceramic paints was analyzed. Elevated cadmium and lead concentrations were identified in the air. Increased concentrations of lead, cadmium, tellurium, arsenic, chromium, cobalt, antimony, silver, vanadium, manganese, selenium, aluminum, titanium were also identified in workers' hair.     

Determination of Hymexazol in Cucumber and Soil Samples by Derivatization Using GC-FPD

63 samples of yak milk were analyzed by the method of ICP-AES of metal elements for aluminum, cadmium, silver and chromium which can reveal the exposed level around yak farm. The metal elements of yak milk were compared to reference data for cow milk, sheep milk, buffalo milk and goat milk. In addition, the concentration was compared to PTWI (provisional tolerable weekly intake) established by the JECFA (WHO/FAO) for metal intake/body weight per week of cadmium, aluminum, and chromium level was compared to EVM (Expert Group on Vitamins and Minerals) guidance level, while the threshold of silver was lacking according to the authority standard. Analysis of regression correlation was calculated between Cd and Co, Cr, Cu, Ag, Al, Mn.     

Heavy Metal Exposure from Personal Care Products

Numerous studies have described human exposure to heavy metals from diverse sources in Nigeria, but little is known about the exposure from personal care products, and few or no report is available on the personal care product concentrations of cadmium, chromium, copper and zinc, which have biotic effects. The levels of these elements were determined in 74 samples of 5 different classes of personal care products commonly used in Nigeria using atomic absorption spectrophotometry. Significant levels of Cd, Cr, Cu and Zn were found in all the products. The highest values of Cd (0.553 ppm) and Cu (0.783 ppm) were observed in hair cream, while medicated cream was mostly implicated for Cr (0.383 ppm) and Zn (0.793 ppm). Since no limit relating to cosmetic products is available, it is difficult to ascertain if the values of metals obtained in this study are too high or low; but Cd and Cr are prohibited in any amount in cosmetics. Prolonged use of soaps and creams containing these elements may pose threat to human health and the environment.     

Hair chromium concentration and chromium excretion in tannery workers.

Hair and urine samples were collected from 34 male tannery workers and from 12 normal adults. Eighteen of the workers dealt directly with chromium and the remaining 16 (controls) worked in the offices and kitchen of the same factory. All were found to be clinically healthy. Chromium was determined by flameless atomic absorption spectroscopy. When compared with normal adult values, urinary chromium concentration, Cr/Creatinine ratio, daily chromium excretion, and hair chromium, concentrations were significantly higher and urinary beta 2-microglobulin/Cre ratios significantly lower in both tannery workers and in controls. A significant negative correlation was found between urinary beta 2-microglobulin/Cre and Cr/Cre ratios of tannery workers and controls. A significant positive correlation was shown between hair chromium and urinary Cr/Cre values in all workers. No correlations between the duration of exposure to chromium and hair and urinary chromium values were found. Nevertheless, high values observed in workers with short exposures show that chromium is readily absorbed through the respiratory system.