Kidney function in stainless steel welders

Summary Seventeen male manual metal-arc stainless steel welders (mean exposure time 20 years) had far higher levels of chromium in urine than individually matched controls (medians 23 vs 1.5 mol/mol creatinine;10.5 vs 0.7 g/g creatinine). However, there were no signs of kidney damage in tests of function of tubuli (-hexosaminidase, lysozyme, and ₂-microglobuline) or glomeruli (albumine clearance).     

泰兴地区肝癌高发因素研究

探讨了泰兴地区人群肝癌的高发因素。采用ELISA法分别检测人群体内HBV感染水平和AFT—SHA含量及生活饮用水水体内MC含量。结果发现该地区人群HBsAg携带率为29．5％,HBV感染阳性率68.1％,肝癌高发乡镇人群HBsAg携带率和HBV感染阳性率分别高达45．8％和94．7％;人群体内AFT—HSA检出率达100％,平均含量为16．39pg／ng;高发乡镇人群体内AFT—HSA平均含量31．99pgM;生活饮用水水体内MC阳性检出率13．2％,河水、沟塘水和浅井水内MC的平均含量分别为36ng／L,29ng／L和25ng／L．结论：人群中的HBV高感染;黄曲霉素强暴露;生活饮用水水体内MC的普遍污染是泰兴地区肝癌高发的三个重要因素．     

Embryotoxicity of chromium: Distribution in pregnant mice and effects on embryonic cells in vitro

The embryonic and fetal uptake of Na₂ ⁵¹Cr₂O₇(Cr VI) was about 10 times higher than that of ⁵¹CrCl₃(Cr III) when these two were given in the same doses i. v. to pregnant C57BL mice. On day 13 of gestation, embryonic concentrations were 12% (Cr VI) and 0.4% (Cr III) of the maternal serum concentration 1 h after injection to the mother. After injection of Cr(III) radioactivity was not detectable in embryonic structures in early gestation, when autoradiographic techniques were used. In late gestation, administration of both forms of Cr resulted in an accumulation in the calcified areas of the fetal skeleton. The radioactivity after administration of Cr(VI) may represent Cr(III) after reduction in the tissues. When added to chick limb bud mesenchymal cells in vitro, Cr(VI) inhibited chondrogenesis at a concentration of about 0.1 g/ml medium, which is around 1/10 of the embryonic concentration achieved after giving teratogenic doses to pregnant mice. Cr(III) on the other hand did not show any overt cytotoxicity even at 15 g/ml ( 500 times higher than the in vivo embryonic concentrations after teratogenic doses). Especially Cr(III) accumulated strongly in the visceral yolk sac, probably after binding to and transport by maternal serum proteins. The possibilities that Cr(III) excerts its teratogenic action by inhibiting embryotrophic nutrition is discussed.     

新砷化合物对小鼠C26移植性肿瘤细胞体内生长抑制作用的研究

目的探讨新砷化合物(AsI3-3Tu)对C26移植性肿瘤细胞的抑制作用及其对肿瘤组织环氧合酶-2(COX-2)及微血管密度(MVD)的影响.方法将Balb/c小白鼠随机分为对照组、5-Fu组和AsI3-3Tu组,于接种C26移植性肿瘤细胞后第6天开始腹腔注射给药,隔天1次,共给药8次,观察抑瘤率,并采用免疫组织化学的方法研究AsI3-3Tu对肿瘤组织COX-2及MVD的影响.结果 AsI3-3Tu对C26移植性肿瘤有明显的抑制作用,抑瘤率为55.07%.免疫组化结果显示,AsI3-3Tu对肿瘤组织的COX-2表达有明显的抑制作用,同时MVD明显降低.结论 AsI3-3Tu对C26移植性肿瘤有抑制作用,其作用途径可能是通过抑制COX-2的表达而抑制肿瘤血管的形成,进而抑制肿瘤的生长.     

妊娠期糖尿病孕妇与正常孕妇血清铬含量的研究

目的　通过对血清铬含量的测定 ,探讨妊娠期糖尿病孕妇是否缺铬。方法　 2 0 0 0～ 2 0 0 1年 ,选择妊娠期糖尿病孕妇 5 0例 ,正常孕妇 4 7例 ,以电感耦合高频等离子体发射光谱法 (ICP AES)测定两组孕妇血清铬含量。结果　妊娠期糖尿病孕妇血清铬含量较正常孕妇明显降低 ,差异有显著性意义 (P <0 0 5 )。结论　建议妊娠期糖尿病孕妇适量补铬     

双波长双指示剂催化动力学光度法测定痕量铬(Ⅵ)

目的:建立测定痕量铬(Ⅵ)的双波长双指示剂催化动力学光度分析的新方法。方法:在稀硫酸介质中,利用痕量铬(Ⅵ)催化溴酸钾氧化甲基橙和结晶紫褪色的指示反应,通过测量510 nm和600 nm下,催化体系和非催化体系吸光度的变化,用双波长双指示剂催化动力学光度测定痕量铬。结果:测定铬的线性范围为0.0010~0.20μg/m l,检出限为1.1×10-10g/m l。结论:该法简单、灵敏度高、选择性好,可用于废水中痕量铬(Ⅵ)的测定。     

Effect of chromium and cobalt ions on primary human lymphocytes in vitro

Cobalt-chromium (Co-Cr) alloy metal-on-metal hip resurfacing is increasingly common among younger more active patients suffering from osteoarthritis. Recent reports have increased awareness of metal ions leaching from metallic articulations; this ion exposure may have adverse effects on the immune system. As previous studies reported alterations in lymphocyte number and function in patients with Co-Cr implants, we investigated effects of clinically relevant concentrations of Cr⁶⁺ and Co²⁺ on primary human lymphocytes in vitro. Here, both resting and activated (anti-CD3 ± anti-CD28 antibodies) primary human lymphocytes were exposed to Cr⁶⁺ or Co²⁺ (0.1–100 µM). Following 24 or 48?h of exposure, cell viability, proliferation, cytokine [interferon-γ (IFNγ and interleukin-2 (IL-2)] release, and apoptosis (with and without pre-treatment of cells with a caspase-3 inhibitor) were assessed. Exposure to 10 and 100 µM Cr⁶⁺ significantly decreased cell viability and increased apoptosis in both resting and activated lymphocytes. Cell proliferation and cytokine release were also significantly reduced in activated lymphocytes following exposure. The exposure of resting lymphocytes to 100 µM Co²⁺ resulted in significant decreases in cell viability accompanied by a significant increase in apoptosis. Activated lymphocytes also showed this response after exposure to 100 µM Co²⁺; in fact, activated cells were significantly more sensitive to Co²⁺ toxicity. Exposure to 10 µM Co²⁺ led to significant decreases in cell proliferation and cytokine release, but no significant increase in apoptosis, in activated cells. The results indicate that exposure to high concentrations of metal ions initiate apoptosis that results in decreased lymphocyte proliferation. IL-2 release is inhibited by both metal ions at concentrations that are not overtly toxic. However, metal ion concentrations not directly cytotoxic to lymphocytes may affect events at a molecular level, thereby impeding lymphocyte proliferation. Hence, this may contribute to altered immune system function in patients with Co-Cr implants.     

Development of an inhalation unit risk factor for hexavalent chromium

A unit risk factor (URF) was developed for hexavalent chromium (CrVI). The URF is based on excess lung cancer mortality in two key epidemiological studies of chromate production workers. The Crump et al. (2003) study concerns the Painesville, OH worker cohort, while Gibb et al. (2000) regards the Baltimore, MD cohort. A supporting assessment was also performed for a cohort from four low-dose chromate plants (Leverkusen and Uerdingen, Germany, Corpus Christi, TX, Castle Hayne, NC). For the Crump et al. (2003) study, grouped observed and expected number of lung cancer mortalities along with cumulative CrVI exposures were used to obtain the maximum likelihood estimate and asymptotic variance of the slope (β) for the linear multiplicative relative risk model using Poisson regression modeling. For the Gibb et al. (2000) study, Cox proportional hazards modeling was performed with optimal exposure lag and adjusting for the effect of covariates (e.g., smoking) to estimate β values. Life-table analyses were used to develop URFs for each of the two key studies, as well as for supporting and related studies. The two key study URFs were combined using weighting factors relevant to confidence to derive the final URF for CrVI of 2.3E-03 per μg CrVI/m³.     

食品中铬的石墨炉原子吸收光谱测定法的改进

目的改进国标方法中石墨炉原子吸收光谱法测定食品中铬的检测方法。方法样品经炭化后,于马弗炉中经灰化完全后,冷却,用浓盐酸溶解样灰,用蒸馏水定容至25 ml,盐酸终浓度为3%,用石墨炉原子吸收仪测定。结果对玉米、花生、萝卜、白菜和鸡肉5种样品进行加标测定,回收率为95.0%～105.0%;有证标准物质测定结果相对标准偏差为1.8%～5.4%,且测定值均在证书给定的标准值范围内;该方法最低检出浓度为0.001 mg/kg(当称样量为2 g时)。结论用该方法对食品样品中铬进行测定,其背景干扰小,步骤简单,操作性强,具有良好的准确度和精密度,完全适合于食品样品中铬的测定。