Urinary multiple marker screening for down's syndrome

We have examined the possibility of using multiple markers in maternal urine rather than serum in order to screen for Down's syndrome. Urine samples were available from 36 cases (24 Down's syndrome, five Edwards' syndrome, three Turner's syndrome, one Klinefelter's syndrome, one triploidy, one triple-X, one twin discordant for Down's syndrome) and 294 controls, including three twins. Three markers were tested: the β-core fragment of human chorionic gonadotrophin (hCG), total oestrogen (tE) and the free a subunit of hCG. Levels were corrected for creatinine excretion and expressed as multiples of the gestation-specific median (MOM) level from the singleton controls. The median value for the singleton Down's syndrome cases was 6.02, 0.74, and 1.08 MOM for β-core-hCG, tE, and a-hCG, respectively. The increases in β-core-hCG and the reduction in tE levels were highly significant (P<0.0001 and 0.005, respectively; Wilcoxon rank sum test) but the increase in free a-hCG was not (P=0.40). On the basis of a mathematical model, the expected detection rate for a 5 per cent false-positive rate was 79.6 per cent for β-core-hCG alone, which increased to 82.3 per cent when combined with tE. Aneuploidies other than Down's syndrome were characterized by low levels of tE and either low or high β-core-hCG.     

Relation of dietary inorganic arsenic exposure and urinary inorganic arsenic metabolites excretion in Japanese subjects

Inorganic arsenic (InAs) is a ubiquitous metalloid that has been shown to exert multiple adverse health outcomes. Urinary InAs and its metabolite concentration has been used as a biomarker of arsenic (As) exposure in some epidemiological studies, however, quantitative relationship between daily InAs exposure and urinary InAs metabolites concentration has not been well characterized. We collected a set of 24-h duplicated diet and spot urine sample of the next morning of diet sampling from 20 male and 19 female subjects in Japan from August 2011 to October 2012. Concentrations of As species in duplicated diet and urine samples were determined by using liquid chromatography-ICP mass spectrometry with a hydride generation system. Sum of the concentrations of urinary InAs and methylarsonic acid (MMA) was used as a measure of InAs exposure. Daily dietary InAs exposure was estimated to be 0.087 µg kg^?1 day^?1 (Geometric mean, GM), and GM of urinary InAs+MMA concentrations was 3.5 ng mL^?1. Analysis of covariance did not find gender-difference in regression coefficients as significant (P > 0.05). Regression equation Log ₁₀ [urinary InAs+MMA concentration] = 0.570× Log ₁₀ [dietary InAs exposure level per body weight] + 1.15 was obtained for whole data set. This equation would be valuable in converting urinary InAs concentration to daily InAs exposure, which will be important information in risk assessment.     

Simultaneous determination of eight metabolites of organophosphate and pyrethroid pesticides in urine

A simultaneous method for quantifying eight metabolites of organophosphate pesticides and pyrethroid pesticides in urine samples has been established. The analytes were extracted using liquid–liquid extraction coupled with WCX solid phase extraction (SPE) cartridges. Eight metabolites were chemically derivatized before analysis using gas chromatography–tandem mass spectrometry (GC–MS–MS). The separation was performed on a HP-5MS capillary column (30 m × 0.25 mm × 0.25 µm) with temperature programming. The detection was performed under electro-spray ionization (ESI) in multiple reaction monitoring (MRM) mode. An internal standard method was used. The extraction solvent, types of SPE cartridges and eluents were optimized by comparing the sample recoveries under different conditions. The results showed that the calibration curves of the five organophosphorus pesticides metabolites were linear in the range of 0.2–200 μg/L (r² ≥ 0.992) and that of the three pyrethroid pesticides metabolites were linear in the range of 0.025–250 μg/L (r² ≥ 0.991). The limits of detection (LODs, S/N ≥ 3) and the limits of quantification (LOQs, S/N ≥ 10) of the eight metabolites were 0.008–0.833 μg/L and 0.25–2.5 μg/L, respectively. The recoveries of the eight metabolites ranged from 54.08% to 82.49%. This efficient, stable, and cost-effective method is adequate to handle the large number of samples required for surveying the exposure level of organophosphorus and pyrethroid pesticides in the general population.     

Relationship of urinary arsenic metabolites to intake estimates in residents of the Red River Delta, Vietnam

This study investigated the status of arsenic (As) exposure from groundwater and rice, and its methylation capacity in residents from the Red River Delta, Vietnam. Arsenic levels in groundwater ranged from <1.8 to 486 μg/L. Remarkably, 86% of groundwater samples exceeded WHO drinking water guideline of 10 μg/L. Also, estimated inorganic As intake from groundwater and rice were over Provisional Tolerable Weekly Intake (15 μg/week/kg body wt.) by FAO/WHO for 92% of the residents examined. Inorganic As and its metabolite (monomethylarsonic acid and dimethylarsinic acid) concentrations in human urine were positively correlated with estimated inorganic As intake. These results suggest that residents in these areas are exposed to As through consumption of groundwater and rice, and potential health risk of As is of great concern for these people. Urinary concentration ratios of dimethylarsinic acid to monomethylarsonic acid in children were higher than those in adults, especially among men, indicating greater As methylation capacity in children.     

MAP结晶法回收和去除尿液中的磷

以分解后的尿液为研究对象,采用MgCl₂·6H₂Ｏ 溶液作为MAP结晶剂,对MAP结晶同步回收尿液中的磷和部分氮的影响因素Mg/PO^３－₄-P摩尔比、反应pH、反应时间、沉淀时间和搅拌速度等进行小试试验.结果表明,Mg/PO^３－₄-P摩尔比是重要的运行参数,当其摩尔比超过1.3∶1时,磷的回收率超过95%,上清液剩余PO^３－₄-P浓度小于10 mg/Ｌ,而提高反应pH不能明显增加磷的回收率.该工艺的最佳运行条件为反应时间20 min,沉淀时间2.0 h,搅拌速度120 r/min,不需要pH调节控制.选择Mg/PO^３－₄-P摩尔比分别为1∶1、1.3∶1和1.5∶1,对在最佳条件下反应获得的3种产物采用SEM、XRD和ICP分析表明,3种产物都为比较纯净的MAP产品,其主要元素P、N、Mg的含量接近于MAP的理论含量（P=12.62%, N = 5.71%, Mg= 9.91%）,分别为13.54%, 5.34%,9.01% (Mg/PO^３－₄-P =1∶1)、13.78%,5.23%,9.36% (Mg/PO^３－₄-P =1.3∶1)和13.34%,5.12%,9.15% (Mg/PO^３－₄-P=1.5∶1),具有较高的回收利用价值.     

尿中1-羟基芘的研究——人体接触多环芳烃的指标

对尿中1-羟基芘的分离和测定方法进行了研究和改进。10ml尿样经酶水解后,用反相高压液相色谱-荧光检测器分析,一小时左右即可得到定量结果,1-羟基芘的检出限为0.047ng。测定了对照组、交通警和焦炉工人尿中1-羟基芘的含量。讨论了人尿中1-羟基芘的量和接触多环芳烃的关系,认为尿中的1-羟基芘可做为人体接触空气中多环芳烃的一个指标。     

我国部分城市和地区居民尿氟含量与饮用水氟含量的相关性

对中国22个城市、2个直辖市和饮水氟含量极高的河北省霸州地区4个村庄的饮用水氟含量与当地18岁左右居民尿氟含量进行相关性分析。结果表明,全国大部分城市饮用水氟含量处于低水平。而包括氟中毒地区在内的全国部分城市和地区饮用水氟含量与尿氟含量存在正相关关系,表明相对其它摄取氟元素渠道来说,饮用水仍然是中国居民氟的主要摄入来源。     

集约化养殖场羊与兔粪尿产生量的监测

以集约化养羊场、养兔场为研究对象,监测了不同季节羊与兔的粪尿排泄量、粪尿养分含量、饲料养分摄入量等.结果表明,兔日平均粪便排泄量0.37 kg·只-1,年粪便排泄总量135.05 kg·只-1,粪便中氮、磷、钾和有机质平均质量含量分别为25.55、5.07、6.59和660.4 g·kg-1;羊日平均粪便排泄量1.09 kg·只-1,年排泄总量397.85 kg·只-1,粪便中氮、磷、钾以及有机质平均质量含量分别为19.89、4.90、11.79和649.1 g·kg-1.同一季节,同种动物磷的排泄量与摄入量比值高于氮、钾,同种动物养分排泄量与摄入量比值在不同季节也有差异.     

卟啉作为人体早期砷暴露生物标志的研究

采用氢化物发生原子吸收分析了贵州省燃煤污染型砷中毒区和非砷中毒区（对照）居民尿样中砷浓度,采用高效液相色谱法分析了卟啉浓度,考察了燃煤污染造成的人体砷暴露与尿液中卟啉排泄改变的关系,寻求慢性砷中毒早期健康效应的生物标志物.结果显示,与对照组相比,砷暴露组尿卟啉Ⅲ（uroporphyrin-Ⅲ）和粪卟啉Ⅲ（coproporphyrin-Ⅲ）显著增高（P＜0.01,P＜0.01）,粪卟啉Ⅰ（coproporphyrin-Ⅰ）比对照组增高,但不显著;不同性别组间比较,对照组和暴露组的中龄（20～40岁）群体尿液中,尿卟啉Ⅲ的浓度在男性和女性群体之间呈显著性的差异（P<0.01）,其它年龄组中,这一指标在不同性别群体之间未见显著性差异;不同年龄分层比较,低龄组（＜20岁）尿卟啉Ⅲ和粪卟啉Ⅲ比对照显著增高（P＜0.01,P＜0.01）,中龄组（20～40岁）和高龄组（＞40岁）粪卟啉Ⅲ比对照显著增高（P＜0.05,P＜0.05）;此外,砷暴露组尿液中砷与总粪卟啉和总卟啉呈正相关（r=0.623,r=0.549）.结果表明,人体砷暴露会导致尿液中卟啉排泄的改变,提示卟啉有可能作为慢性砷中毒早期健康效应的生物标志.     

Urea hydrolysis and recovery of nitrogen and phosphorous as MAP from stale human urine

Laboratory-scale tests for magnesium ammonium phosphate(MAP)precipitation following urea hydrolysis of human urine were conducted using orthogonal experiment design.The effects of initial pH,temperature and the volumetric ratios of stale urine to fresh urine,on urea hydrolysis in urine were studied to determine the final hydrolysis time to recover most nitrogen from separated human urine by MAP.With a volumetric ratio of stale to fresh urine>10% and at temperature≥20℃,urea hydrolysis could be completed i...