六价铬的危害性评价及其检测回顾

目的对六价铬的危害性及检测方式进行总结,为未来铬的监测和质量控制提供思路。方法简要总结六价铬的一般形式及暴露源、毒理作用及危害性评价,系统概括六价铬检验研究的情况。结果对铬水平的监测,需要检测其不同氧化态,结合有关毒理研究数据,方可得到更为准确的结果。结论单纯的总铬或不同价态铬的测试结果,不能反映出人类是否处于一个高潜在性的危害状态,因此,作为一种人类必需的元素,铬的危害性评价需要进行综合性的分析。     

比色法快速检测药用胶囊铬限量

目的 建立一种简便而快速判定药用胶囊中铬限量的方法.方法 选择湿法消解法处理胶囊,加入显色剂二苯碳酰二肼发生显色反应,与标准铬对照液比较,判定其铬含量是否超标.结果 比色法与药典规定的原子吸收光谱法检测结果相符.结论 比色法能简便而快速判定药用胶囊中铬含量是否超标.     

石墨炉原子吸收光谱法测定矿泉水中总铬的不确定度分析

目的分析石墨炉原子吸收光谱法测定矿泉水中总铬的测量不确定度。方法应用测量不确定度评定理论,结合试验方法,建立数学模型,确定和计算测定过程各不确定度分量,分析石墨炉原子吸收光谱法测定矿泉水中总铬的测量不确定度。结果矿泉水中总铬含量为3.87μg/L,取包含因子k=2,其扩展不确定度为0.16μg/L,最终报告矿泉水中的总铬含量为（3.87±0.16）μg/L;同时对影响测定结果的不确定度的各部分因素进行了量化,由标准物质引入的相对不确定度分量urel（标准）=1.1%;由标准曲线引入的相对不确定度分量urel（拟合）=1.3%,由重复测定引入的不确定度分量urel（重复）=0.93%,由回收率引入的不确定度分量urel（Rec）=0.89%。结论影响测量结果的不确定度主要因素是标准曲线拟合引入的误差,标准物质及其稀释过程引入的不确定度次之,其他因素如环境条件、重复测定、回收率等对测量结果的不确定度影响较小。     

^32P胶体联合顺铂胸腔灌注治疗恶性胸腔积液临床观察

目的：探讨采用胸腔内灌注胶体磷酸^32P铬注射液（^32P胶体）和顺铂治疗恶性肿瘤大量胸腔积液的临床疗效和副反应．方法：46例恶性胸腔积液患者随机分为两组,治疗组25例,对照组21例．在胸腔闭式引流使胸水量减少到一定程度后,治疗组分别采用^32P胶体和顺铂胸腔内灌注治疗,对照组以^32P胶体单纯胸腔内灌注治疗．结果：治疗组可统计病例24例,临床反应完全缓解（CR）11例（45．8％）,部分缓解（PR）9例（37．5％）,无效（NC）4例（16．7％）,总有效率83．3％,其中5例CR和2例PR患者经2mo的观察无明显的复发;对照组CR1例（4．8％）,PR7例（33．3％）,NC13例（61．9％）．治疗组总有效率明显高于对照组（x^2=9．75,P〈0．01）,副作用主要是轻度全身反应和轻度骨髓抑制．结论：中心静脉导管胸腔闭式引流后胸腔内注入^32P胶体及顺铂是临床上治疗恶性胸腔积液的有效方法,无严重不良反应.     

Determinants of urinary 8-hydroxy-2'-deoxyguanosine in Chinese children with acute leukemia

The 8-hydroxy-2'-deoxyguanosine (8-OHdG), an oxidized nucleoside of DNA, not only is a widely used biomarker for the measurement of endogenous oxidative DNA damage, but might also be a risk factor for many diseases including cancer. Elevated level of urinary 8-OHdG has been detected in patients with various malignancies. In the present study, the level of urinary 8-OHdG was examined in 116 Chinese children with acute leukemia (94 acute lymphoid leukemia, ALL, 22 acute myeloid leukemia, AML), and its correlation with urinary metal elements was investigated. Our result showed that the level of urinary 8-OHdG in children with acute leukemia before treatment was significantly elevated compared with that in normal controls (11.92 +/- 15.42 vs. 4.03 +/- 4.70 ng/mg creatinine, P < 0.05). In particular, urinary 8-OHdG was higher in children with acute leukemia aged under 3 years (20.86 +/- 21.75 ng/mg creatinine) than in those aged 3-15 years (8.09 +/- 9.65 ng/mg creatinine), whereas no differences were shown in terms of gender, parental smoking and education, household income, place of residence, and use of paracetamol. In addition, urinary 8-OHdG levels were similar among different subtypes of acute lymphoid leukemia (ALL) patients. Furthermore, linear regression analysis revealed a significant correlation between urinary 8-OHdG and urinary Cr, but not Fe or As, in group aged <3 years compared with group aged 3-15 years (P = 0.041), indicating that the metal elements may be involved in increasing urinary 8-OHdG level in younger children with acute leukemia. Our results suggest that children with acute leukemia undergo an increased risk of oxidative DNA damage, which may be correlated with high level of Cr exposure in Chinese children with acute leukemia.     

In vitro bioavailability of heavy metals in pressure-treated wood dust.

Pressure treatment with chromium, copper, and arsenic (CCA) is the most prevalent method for protecting wood used in outdoor construction projects. Although these metals are tightly bound to the wood fibers and are not released under most conditions of use, we examined the bioavailability of metals in CCA pressure-treated wood dust in vitro. Cytotoxicity and metallothionein (MT) mRNA expression were examined in V79 Chinese hamster lung fibroblast cells incubated with respirable-size wood dust generated by sanding CCA-treated and untreated (control) Southern yellow pine. In colony survival studies, increased cytotoxicity (p < 0.05) occurred in V79 cells treated with CCA wood dust (351 +/- 77 microg/ml, mean +/- SE) compared with control wood dust (883 +/- 91 microg/ml). Increased cytotoxicity with CCA wood dust also occurred in an arsenic resistant subline of V79 cells, thus suggesting that arsenic was not responsible for the increased cytotoxicity. Metallothionein mRNA was significantly increased after 48 h of treatment with CCA wood dust compared with control wood dust. Incubation of CCA wood dust in cell culture media resulted in the transfer of copper, but not chromium or arsenic, into the media. Moreover, the treatment of cells with this filtered extract resulted in significantly increased metallothionein mRNA, suggesting that bioavailable copper is responsible for inducing metallothionein mRNA in V79 cells. Thus, these bioassays suggest that metals become bioavailable during in vitro culture of phagocytic V79 cells with CCA wood dust.     

三种牙科钴铬生物烤瓷合金抗拉强度的对比测试研究

目的 对比测试新型国产钴铬生物烤瓷合金（CW-CC）、德国产BEGO Wirron bord C合金和德国Reminum 2000合金的抗拉强度,为进一步的研制开发适合临床要求的生物合金提供实验依据.方法 将3种合金各制备5个试样,打磨修整后用万能测试机测量其合金的抗拉强度,并采用SEM分析其抗拉强度的差异.结果 CW-CC钴铬生物烤瓷合金抗拉强度（785±21）MPa与德国Reminum 2000合金抗拉强度（764±15）MPa比较差异无统计学意义（P＞0.05）,与德国产BEGO Wirron bord C合金抗拉强度（680±12）MPa比较,差异有统计学意义（P＜0.05）.结论 新型国产钴铬生物烤瓷合金的抗拉强度达到烤瓷合金的性能要求.     

高铬酵母的制备及其有机铬含量的研究

目的 :　通过在培养基中添加无机铬化合物的方法制备有机铬含量较高的高铬酵母 ,并对高铬酵母中总铬和有机铬的含量进行分析。方法 :　以麦芽汁为培养基 ,啤酒酵母菌接种量为 1 0 % ,Cr Cl3的添加浓度为 2 0 .0 mg/L,2 8℃ ,培养 48h。结果 :　所得高铬酵母中的总铬和有机铬含量可分别达到 2 60 .2μg/g和 2 1 6.0μg/g;紫外光谱分析 ,高铬酵母在 2 60 nm处有特征吸收峰 ;红外光谱分析 ,高铬酵母在 478cm- 1 (波数 )处有特征吸收峰 ;用氨基酸自动分析仪对高铬酵母中的 1 7种氨基酸含量进行分析 ,证实高铬酵母中的氨基酸含量大多高于普通酵母 ,尤其是赖氨酸、蛋氨酸、亮氨酸、异亮氨酸等人体必需氨基酸的含量明显提高。结论 :　通过该法可以制备有机铬含量及营养价值较高的高铬酵母     

五种常用口腔修复材料对细菌滞留影响的临床研究

目的:评价不同修复材料对牙周组织的潜在危害.方法:采用临床实验的方法观察了5种常用口腔修复材料在体内戴用2个月后的细菌粘附量及其种类.结果:(1)树脂粘附的微生物最多,其次为钴铬合金和镍铬合金,纯钛和Ⅲ型金合金最少;(2)G-杆菌在树脂组明显多于钴铬合金和镍铬合金组,在纯钛和Ⅲ型金合金上粘附最少.对于G-球菌,树脂组明显多于钴铬合金、镍铬合金和纯钛组,Ⅲ型金合金组最少.白色念珠菌在树脂组有少量粘附,但在4种牙科金属上粘附量极少.结论:从对牙周组织的危害程度看,纯钛和Ⅲ型金合金应为临床医生的首选材料,其次为钴铬合金和镍铬合金.