高砷暴露致皮肤损伤人群尿砷代谢产物分析

目的 探讨高砷暴露致皮肤损伤人群尿砷代谢的特点.方法 应用氢化物发生.冷阱捕获.原子吸收分光光度法测定高砷暴露地Ⅸ(水砷浓度分别为0.21、0.24、0.36 mg/L)皮肤损伤组人群(77人)和未见皮肤损伤对照组人群(77人,性别、年龄1:1配比)尿中无机砷(iAs)、一甲基胂酸(MMA)和二甲基胂酸(DMA)含量.以iAs、MMA及DMA的总和表示总砷(tAs)水平;以iAs/tAs、MMMtAs和DMA/tAs分别计算iAs%、MMA%、DMA%;以(MMA+DMA)/tAs及DMM(MMA+DMA)分别计算一甲基化率(FMR)和二甲基化率(SMR)水平.结果 皮肤损伤组人群与对照组人群相比尿中各形态砷化合物及总砷含量差异无统计学意义(JD>0.05),而皮肤损伤组尿iAs%水平高于对照组,DMA%、FMR和SMR水平低于对照组差异均有统计学意义(P<0.05).皮肤损伤组人群中男性SMR水平显著低于女性,且尿中MMA%显著高于女性(P<0.05).结论 高砷暴露情况下,出现皮肤损伤症状的人群对砷的甲基化能力较低.

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Objective To explore the characteristics of urine arsenic metabolism of people with skin lesion. Methods The levels of inorganic arsenic (iAs), monomethylated arsenic (MMA), dimethylated arsenic (DMA) in urine were detected with hydride generation-cold trap-atomic absorption spectroscopy among population exposed to higher levels of arsenide (0.24 ,0.36,0.21 mg/L), which consisted of skin lesion group(n=77) and non-skin lesion group (n=77,control group) in Apr.,2009 . Total arsenic (tAs) , iAs %, MMA%, DMA%, the first methylation ratio (FMR) and the secondary methylation ratio (SMR) were calculated as iAs + MMA+ DMA , iAs/tAs, MMA/tAs, DMA/tAs, (MMA + DMA)/ tAs and DMA/(MMA + DMA), respectively. Results No significant difference was observed in urinary concentrations of arsenic species and tAs between two groups (P>0.05), iAs% was much higher and the levels of FMR, SMR and DMA% were significantly lower in skin lesion group compared with the control (P<0.05). There were statistically significant differences in iAs% and SMR between males and females of the skin lesion group(P<0.05). Conclusion The arsenic methylation capacity of the persons with skin lesions is lower at high arsenic exposure.     

吸烟对人类砷代谢和甲基化影响的Meta分析

目的 探讨吸烟是否影响人类对砷的代谢和甲基化.方法 检索纳入有关吸烟和砷代谢产物关系的1994-2008年发表的文献6篇,应用随机效应模型和同定效应模型对吸烟与人尿中无机砷(iAs)、一甲基胂酸(MMA)、二甲基胂酸(DMA)含量占总砷百分比的关系进行综合的定量分析.结果 吸烟组尿中iAs百分比的合并加权均数差(weight meandifference,WMD)为0.59(95%CI:-0.01～1.18);吸烟组尿中MMA百分比的合并WMD为2.44(95%CI:1.95～2.94);吸烟组尿中DMA百分比的合并WMD为-3.04(95%CI:-4.01-2.07). Meta分析提示吸烟组尿中MMA百分比高于非吸烟组,而吸烟组尿中DMA百分比低于非吸烟组.结论 吸烟可能是人类对砷代谢和甲基化影响因素之一.

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Objective To investigate whether smoking affects metabolism and methylation of arsenic. Methods Six papers about the relation between smoking and arsenic metabolism, methylation were collected until December,2008, and the data were quantitatively analyzed with random and fixed effect models. Results In the group of smoking, the summary weighted mean difference of percent of inorganic in urinary was 0.59 (95% CI:-0.01 - 1.18). The summary weighted mean difference of percent of MMA in urinary was 2.44 (95%CI:1.95 - 2.94). The summary weighted mean difference of percent of DMA in urinary was -3.04 (95%CI:-4.01 --2.07). Current evidence suggested that percent of MMA was higher, percent of DMA was lower in smoking or ever smoking group compared with nonsmoking group. Conclusion Smoking may be considered a risk factor for metabolism and methylation of arsenic on human.     

偏食高碘大鼠动物模型的建立

目的 建立偏食及高碘喂养的大鼠动物模型,观察其尿碘的变化规律.方法 将SPF/VAF级动物Wistar大鼠随机分8组(每组8只):常规饲料组分为对照组(NC)、10倍碘组(10 HI-N)、50倍碘组(50HI-N)、100倍碘组(100HI-N);偏食饲料组也分为对照组(MC)、10倍碘组(10 HI-M)、50倍碘组(50 HI-M)、100倍碘组(100 HI-M),高碘组饮水碘含量(以I计)分别为1 400、7 600、15 350 μg/L,每日总碘摄入量分别为对照组的10、50、100倍.每周称体重,并分别于暴露2、4和6个月测定尿碘.结果 与NC组比较,各偏食高碘组体格发育迟滞.常规饲料组和偏食饲料组尿碘均随碘摄入量的增加而明显增加(P＜0.01),50 HI-M、100HI-M组尿碘分别高于相应常规饲料组(均为P<0.01).结论 偏食高碘大鼠生长和尿碘有明显异常,可作为有效的研究模型.

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Objective To observe urinary iodine levels in the rat model for excessive iodine intake and monophagia.Methods Wistar rats were randomly divided into 8 groups:normal diet control group(NC),10-fold iodine+normal diet group(10 HI-N),50-fold iodine+normal diet group(50 HI-N),100-fold iodine+normal diet group(100 HI-N),monophagia control group(MC),10-fold iodine+monophagia group(10 HI-M),50-fold iodine+monophagia group(50 HI-M),100-fold iodine+monophagia group(100HI-M).The excessive iodine intake groups exposed to 1 400,7 600,15 350μg/L I-through drinking water presented higher levels of daily iodine intake,which were 10,50,100 times of those in control groups.During the exposure period,the body weights of the rats were measured weekly,the levels of urinary iodine were determined at the second.the fourth and the sixth month.Results The body weights of the excessive iodine intake groups with monophasia were lower than that of the NC group.In normal diet groups and monophagia diet groups.the levels of urinary iodine increased with the increase of iodine intake.The levels of urine iodine in 50 HI-M group and 100 HI-M group were significantly higher than those of the related groups with higher iodine intake.Conclusion The experimental animal model of excessive iodine intake and monophagia are successfully established in the present research,with physical retardation and higher urinary iodine.     

海苔摄入对尿中多形态砷化物排泄影响

目的 探讨人体摄入海苔后尿中不同形态砷化物随时间的排泄情况,为判定和评价海苔中砷化物的形态和在体内的代谢与排泄规律提供实验依据.方法 采用氢化物发生-超低温捕集-原子吸收分光光度法检测尿中砷代谢产物的形态与含量.结果 男性食用海苔后12 h,尿中无机砷(iAs)浓度增高(P＜0.05);12,24,36h尿中二甲基砷(DMA)浓度增高(P＜0.05);甲基砷(MMA)浓度在食用海苔前后未见明显改变.女性食用海苔后的9,12,36 h,尿中iAs浓度增高(P＜0.05);5,24 h尿中MMA浓度增高(P＜0.05);3～72 h尿中DMA浓度均增高(P＜0.05).男女在食用海苔前后尿中三甲基砷(TMA)浓度均未见明显变化.结果 人体对海苔中的砷化物代谢存在着明显的性别差异,女性对砷的代谢与排泄速率高于男性.     

低蛋白饮食对3/4期慢性肾脏病患者肾功能及营养状况的影响

Objective To assess the influences of low-protein diet on the renal function and nutritional status in patients with stage 3/4 chronic kidney diseases (CKD).Methods Totally 34 patients with stage 3/4 CKD were randomly divided into group A (protein intake:0.6 g·kg~(-1)·d~(-1);n=14) and B (protein intake:0.8 g·kg~(-1)·d~(-1);n=20).Anthropometric measurement and blood biochemical tests were performed,nutri-tional status was assessed,and 24-hour dietary recall survey was conducted before and after the treatment.Patients were followed up for 6 months.Results In group A,the creatinine level significantly decreased (P=0.010),while albumin level (P=0.042) and the intake of energy (P=0.018) and carbohydrate (P<0.001) signifi-cantly increased after the treatment In all the 34 patients,in group A and group B,the malnutrition rates were de-creased by 14.7%,7.2%,and 21.1% after nutritional intervention.Conclusion The low-protein diet (protein intake 0.6 g·kg~(-1)·d~(-1)),in which part of the staple food was replaced by wheat starch,can increase the in-takes of carbohydrate and energy and improve renal function and nutritional status in patients with stage 3/4 CKD.     

田间作业致有机磷农药中毒与口服中毒的临床比较

目的 探讨田间作业中毒和口服有机磷农药中毒在临床表现及治疗上的差异.方法 回顾性分析我院2007年7月至2010年7月收治的85例中、重度急性有机磷农药中毒患者的临床资料,按中毒途径分为口服组(51例)和非口服组(34例),比较不同途径中毒后的临床表现、治疗特点及预后.结果 口服组中度中毒患者的肌颤肌痉挛和共济失调的发生率(86.4%、90.9%)均明显高于非口服组(50.0%、55.0%),差异有统计学意义(P＜0.05,P<0.01);口服组重度中毒患者的肺水肿、肌颤肌痉挛及昏迷的发生率(100.0%、89.7%、93.1%)均明显高于非口服组(71.4%、64.3%、50.0%),差异有统计学意义(P<0.05 ).非口服组解毒时间[中度:(35.0±6.2)h、重度:(45.0±11.1)h]较口服组[中度:(49.0±7.7)h、重度:(77.0±10.3)h]明显缩短,差异有统计学意义(P＜0.05).治疗后24、48、72 h,中、重度非口服组胆碱酯酶活力明显高于口服组,差异有统计学意义(P<0.05或P<0.01);中、重度非口服组的氯磷定用量、阿托品化用量及阿托品总量明显低于口服组,差异有统计学意义(P＜0.05或P<0.01).结论 田间作业有机磷农药中毒在临床表现上与口服中毒不尽相同,且治疗的阿托品及氯磷定用量相对较少,胆碱酯酶活力恢复较快.

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Objective To investigate the differences of clinical manifestation and therapy of organophosphorus pesticide poisoning (OPP) between oral exposure and occupational exposure in field work. Methods From July 2007 to July 2010, 85 patients with acute severe OPP were treated in a hospital, which were divided into oral poisoning group (51 cases) and non-oral poisoning group (34 cases). The differences of clinical manifestations, curative effects and prognosis between two groups were compared. Results The rates of myoclonus and ataxia in cases with moderate poisoning of oral poisoning group were 86.4% and 90.9%, which were significantly higher than those (50.0% and 55.0% ) of non-oral poisoning group (P<0.05 or P< 0.01). The rates of myoclonus, lung fluid and coma in cases with severe poisoning of oral poisoning group were 100.0%, 89.7% and 93.1%, respectively, which were significantly higher than those (71.4%, 64.3% and 50.0%) of non-oral poisoning group (P<0.05). The mean detoxification hours in cases with moderate poisoning and cases with severe poisoning of non-oral poisoning group were (35.0±6.2) and (45.0±11.1) hours which were significantly lower than those [(49.0±7.7) and (77.0±10.3) hours] in cases with moderate poisoning and cases with severe poisoning of oral poisoning group (P<0.05). In 24, 48 and 72 h after treatment, the cholinesterase (ChE) activities of non-oral poisoning group were higher than those of oral poisoning group (P< 0.05 or P<0.01). The used doses of pyraloxime methylchloride (PAM-Cl) or atropine and the used total dose of atropine in non-oral poisoning group were lower than those in oral poisoning group (P<0.05 or P<0.01). Conclusions The clinical manifestation of non-oral poisoning group is different from the clinical manifestation of oral poisoning group due to the high morbidity of OPP occurred at field site in summer. The used doses of atropine and PAM-Cl are less and the ChE activity recovers quickly for non-oral poisoning group.     

超声在女性压力性尿失禁诊治中的应用价值

目的 探讨超声参数在评估女性压力性尿失禁(SUI)中的作用及意义.方法 应用超声测量46例女性SUI患者(研究组)行经闭孔无张力悬吊带术(TVT-O)前后膀胱颈活动度、膀胱尿道后角、尿道角及残余尿量的变化,并与43例体检正常妇女(对照组)进行比较.结果 研究组术前膀胱颈活动度及膀胱尿道后角[(14.46±1.28)mm、(124.87±2.95)°]大于对照组[(7.47±0.55)mm、(107.83±3.24)°](P＜0.01),尿道角[(23.61±2.28)°]小于对照组[(36.24±2.23)°](P＜0.01);研究组术后各参数与对照组比较,差异均无统计学意义(P＞0.05).研究组术后膀胱颈活动度及膀胱尿道后角[(7.84±0.76)mm、(108.74±3.63).]小于术前(P＜0.01),尿道角[(34.39±3.46).]大于术前(P＜0.01),而残余尿量组内、组间比较差异均无统计学意义(P＞0.05).结论 女性SUI患者经手术治疗后膀胱颈活动度、膀胱尿道后角、尿道角都有不同程度的改变,可以基本恢复到正常状态,且疗效相对稳定;手术不增加患者的残余尿量;超声在排除精神心理因素之后,对客观评估病情轻重和治疗后的恢复状态有着其他检查手段不可代替的优势.

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Objective To evaluate the significance and role of ultrasound parameters in the female stress urinary incontinence (SUI). Methods The changes of the distance of bladder neck mobility,posterior urethra-vesical angle,urethral angle and residual urine volume before and after the operation of transobturator tension-free vaginal tape surgery (TVT-O) for 46 cases of female SUI (experimental group ) by ultrasound were studied,and compared with 43 normal women (control group). Results The experimental group before the operation had the greater distance of bladder neck mobility and posterior urethra-vesical angle [(14.46 ± 1.28) mm, (124.87 ±2.95)°] than the control group [(7.47 ±0.55) mm, (107.83 ±3.24)°] (P ＜ 0.01 ), but the urethral angle [( 23.61 ± 2.28 )°] was smaller than the control group [(36.24 ±2.23 )°] (P ＜ 0.01 ). There was no significant difference in the distance of bladder neck mobility, posterior urethra-vesical angle, urethral angle and residual urine volume between the experimental group after the operation and the control group (P ＞ 0.05 ). The experimental group before the operation had the greater distance of bladder neck mobility and posterior urethra-vesieal angle than those after the operation [(7.84±0.76) mm, (108.74±3.63)°] (P ＜0.01), the urethral angle was smaller than that after the operation [(34.39 ± 3.46)°] (P ＜ 0.01 ), but the residual urine volume had no significant difference (P ＞ 0.05 ).Conclusions After the operation, there are some changes in the distance of bladder neck mobility, posterior urethra-vesical angle and urethral angle for the patients with female SUI,and these parameters can be restored the normal state,and have the relatively stable effect. The residual urine volume dosen't increase after the operation. Ultrasound has the advantage in objectively assessing the severity and recovery status after the operation exclusion of mental and psychological factors.     

饮食、C反应蛋白与2型糖尿病颈动脉内膜厚度的关系

Objective To compare the characteristics of food and nutrition intake in type 2 diabetes mellitus (T2DM) patients with or without carotid atherosclerosis and analyze the relationship between diets/C-reactive protein (CRP) and carotid intima-media thickness (C-IMT). Methods Sixty patients with T2DM were enrolled and divided into two groups based on C-IMT: group A (C-IMT ＜ 1 mm, n=30) and group B (C-IMT≥1 mm, n=30). All subjects were investigated with questionnaires including 3-day food recall They all took somatometric measurement. Blood and urine samples were collected in all subjects to examine the levels of high sensitive-CRP,C-peptide, blood glucose, glycosylated hemoglobin, blood lipid, renal function, urine microalbumin, and other indicators. Results The intakes of vegetables, fruits, and aquatic products were significantly higher in group A than in group B ( P ＜ 0. 05 ). The intake of vitamin C in group A was significantly higher than that in group B ( P ＜0. 05 ). The levels of CRP in group B was significant higher than that in group A (P = 0. 000). Positive correlation was found between CRP level and C-IMT in T2DM patients ( r = 0. 36, P = 0. 004). Furthermore, CRP was negatively correlated with the intakes of vegetables and fruits ( r = - 0. 334, P = 0. 01 ), aquatic products ( r = -0. 315, P = 0. 016), and vitamin C ( r = - 0. 2786, P = 0. 038 ), respectively. The intake of fruits was negatively correlated with C-IMT (r, = -0. 33, P = 0. 01 ). Conclusions T2DM patients without carotid atherosclerosis intake more vegetables, fruits, aquatic products and vitamin C than those with atherosclerosis. Vegetables, fruits,sea foods and vitamin C may be the protective factors against atherosclerosis in T2DM patients. CRP is associated with the development of atherosclerosis in T2DM patients.     

微波诱导小胶质细胞的促炎症反应

Objective To explore the relationship between microglia] proinflammatory and electro-magnetic radiation and unveil the role of microglia in microwave radiation induced central nervous system in-jury. Methods N9 microglia cells cultured in vitro were exposed to microwave at 90 mW/cm2. Cell flow cy-tometry was used to observe the expression of CD1 lb at different time points after exposure; ELISA was used to detect the concentration of TNF-α in N9 cell culture supernatant; RT-PCR analysis confirmed iNOS mRNA ex-pression in N9 microglia cells; and Nitrate Reductase Method was used to test NO amount in culture super-natant. Results The CD11b positive microglial cells increased significantly at 3 h after microwave exposure (P<0.05), continued to increase until 24 h and peaked at 6 h after exposure. The amount of TNF-α rose dra-matically from 1 h to 24 h after exposure (P<0.01) and peaked at 3 h [(762.1±61.5) pg/ml] after exposure (P< 0.01). The level of NO started to increase at 1 h [(4.48±0.59) μmol/L] and lasted for 24 h after exposure. The expression of iNOS mRNA increased significantly at 1 h(P<0.05), and tripled the original expression at 6 h af-ter exposure, hereafter, it decreased slightly, but all were higher than the control group within 24 h after exposure. Conclusion Microwave radiation could induce the activation of microglia cells. The activated microglia cells could induce microglial proinflammatory by producing large amounts of TNF-α, NO, etc.     

内蒙古不同浓度砷暴露人群尿砷代谢产物研究

目的 测定内蒙古地区饮用高砷水人群尿砷代谢产物，探讨不同人群砷代谢的特点。方法 采用氢化物发生原子吸收分光光度法检测尿中不同形态的砷代谢产物。结果 2个暴露组人群尿中无机砷（iAs，inorganic arserlic）、甲基砷（MMA，monomethylarsine）、二甲基砷（DMA．dimethylarsine）和总砷（TAs，total arserlic）均高于对照组（P〈0．05）；同样砷暴露水平下，尿中各形态砷含量及其相对比在不同性别问的差异均无统计学意义（P〉0．05），儿童DMA／MMA和DMA％高于成人（P〈0．05），MMA％低于成人（P〈0．05）；2个暴露组儿童、成人分别与对照组比较，暴露组MMA／ias、DMA／MMA、DMA／iAs、DMA％显降低（P〈0．05），而iAs％、MMA％显增高（P〈0．05）；高暴露组与低暴露组相比，儿童DMA／MMA、DMA／iAs、DMA％显增高（P〈0．05），iAs％、MMA％显降低（P〈0．05）。结论 相同砷暴露水平下，男女对砷的甲基化能力无差别，儿童二甲基化能力高于成人。高砷暴露可能降低人群对砷的生物甲基化能力。[编按]     

饮水型砷暴露对人群甲基化代谢能力的影响

目的探讨饮水型砷暴露对人群甲基化代谢能力的影响。方法以带有砷化物预处理装置的原子吸收分光光度计测定砷暴露人群及无砷暴露对照人群血、尿中无机砷(iAs)、甲基胂(MMA)、二甲基胂(DMA)含量。以iAs、MMA及DMA的总和表示总胂(tAs)水平;以(MMA+DMA)/tAs及DMA/(MMA+DMA)分别计算一甲基化率(PMI)和二甲基化率(SMI)水平。结果砷暴露人群血中iAs、MMA、DMA、tAs及PMI水平均显著高于相应对照人群的水平,而SMI水平显著低于对照人群。尿中MMA水平分别与血中PMI及SMI水平呈显著正相关(r=0.419,P<0.01)及负相关(r=-0.326,P<0.05)。暴露组和对照组血中各种砷化物水平及甲基化率水平在男女间差异无显著性。结论砷暴露人群与无砷暴露人群相比甲基化率有差异,PMI显著增高,SMI显著降低。人群甲基化率无显著性别差异。     

HPLC-ICP-MS speciation analysis of arsenic in urine of Japanese subjects without occupational exposure

The toxicity and carcinogenicity of arsenic depend on its species. Individuals living in Japan consume much seafood that contains high levels of organoarsenics. Speciation analysis of urinary arsenic is required to clarify the health risks of arsenic intake. There has been no report of urinary arsenic analysis in Japan using high performance liquid chromatography with inductively coupled plasma mass spectrometry (HPLC-ICP-MS). We performed speciation analysis of urinary arsenic for 210 Japanese male subjects without occupational exposure using HPLC-ICP-MS. The median values of urinary arsenics were as follows: sodium arsenite (AsIII), 3.5; sodium arsenate (AsV), 0.1; monomethylarsonic acid (MMA), 3.1; dimethylarsinic acid (DMA), 42.6; arsenobetaine (AsBe), 61.3; arsenocholine, trimethylarsine oxide, and unidentified arsenics (others), 5.2; and total arsenic (total As), 141.3 microgAs/l. The median creatinine-adjusted values were as follows: AsIII, 3.0; AsV, 0.1; MMA, 2.6; DMA, 35.9; AsBe, 52.1; others 3.5; and total As, 114.9 microgAs/g creatinine. Our findings indicate that DMA and AsBe levels in Japan are much higher than those found in Italian and American studies. It appears that the high levels of DMA and AsBe observed in Japan may be due in part to seafood intake. ACGIH and DFG set the BEI and BAT values for occupational arsenic exposure as 35 microgAs/l and 50 microgAs/l, respectively, using the sum of inorganic arsenic (iAs), MMA, and DMA. In the general Japanese population, the sums of these were above 50 microgAs/l in 115 (55%) samples. We therefore recommend excluding DMA concentration in monitoring of iAs exposure.     

Urinary arsenic metabolites in children and adults exposed to arsenic in drinking water in Inner Mongolia, China

BACKGROUND: We report the concentrations and distributions of urinary arsenic (As) metabolites in 233 residents exposed to 20, 90, or 160 microg/L inorganic arsenic (iAs) in drinking water from three villages in Hohhot, Inner Mongolia, China, that formed one control and two exposed groups. METHODS: We used hydride generation-atomic absorption spectrometry (HGAAS) to determine iAs, monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA). RESULTS: The concentrations of each urinary As species in the two exposed groups were significantly higher than in the control group for both children and adults. Both children and adults in exposed groups had higher percent iAs and MMA and lower percent DMA, and low primary and secondary methylation indices (PMI and SMI, respectively) than those in the control group. However, children showed significant increases in percent DMA and the SMI as well as decreases in the percent MMA when the iAs exposure level increased from 90 to 160 microg/L. In addition, children in the two exposed groups showed lower percent MMA but higher percent DMA and higher SMI than adults in the same exposed group. No significant differences in As metabolite concentrations and distributions were found between males and females in each group. A significant correlation was also found in the SMI between 11 pairs of children and their mothers from the 160-microg/L-exposed group. CONCLUSIONS: Children had higher a capacity for secondary methylation of As than adults when exposed to the same concentrations of iAs in drinking water. Exposure to As may increase the capacity for methylation in children to some extent.     

GSTT1和GSTM1基因多态性与人体砷甲基化代谢水平关系探讨

目的探讨GSTT1、GSTM1基因多态性与人体砷甲基化代谢水平之间的关系。方法选择某工业性砷污染区的247名成年常住居民为研究对象。采用多重PCR法检测GSTM1和GSTT1基因多态性。离子色谱氢化物发生原子荧光法(IC-HG-AFS)测定尿中无机砷(iAs)、一甲基胂酸(MMA)和二甲基胂酸(DMA)。结果GSTT1缺失基因型人群与GSTT1非缺失基因型人群尿中iAs比例、DMA比例和MMA比例相比较,差异均无统计学意义(P>0.05)。GSTM1缺失基因型人群与GSTM1非缺失基因型人群尿中iAs比例、DMA比例和MMA比例相比较,差异均无统计学意义(P>0.05)。四组不同GSTT1和GSTM1联合基因型人群尿中iAs比例、DMA比例和MMA比例相比较,四组间差异也均无统计学意义(P>0.05)。结论本研究未发现GSTT1、GSTM1基因多态性与砷代谢水平之间存在显著关联。     

砷暴露母子砷代谢特点及DNA损伤差异

目的通过尿中各种形态砷水平，探讨高砷暴露下儿童砷代谢特点；测定尿中8-羟基脱氧鸟苷（8-O-HdG）水平。初步探讨砷暴露对儿童DNA的损伤情况；并比较砷暴露对儿童与成人的不同影响。方法以氢化物发生．冷原子捕获．原子吸收分光光度法测定尿中各种砷化物的含量；以试剂盒法测定尿8-OHdG水平。结果砷暴露组妇女和儿童尿中无机砷（iAs）、二甲基砷（MMA）、甲基砷（DMA）及总砷（tAs）水平均显著高于对照组；砷暴露母子间，子女尿中iAs、DMA、tAs及DMA／tAs水平显著高于其母亲，而MMA／（MMA＋DMA）显著低于其母亲。母子间8-O-HdG水平差异无统计学意义。结论高砷暴露下，儿童二甲基化能力高于成人，DNA氧化损伤与成人相比不明显。     

Study on the relationship between GSTM1, GSTT1 gene polymorphisms and arsenic methylation level

OBJECTIVE: To investigate the relationship between genetic polymorphisms of GSTT1, GSTM1 and arsenic methylation level. METHODS: 247 residents in an industrial arsenic polluted village were randomly selected as subjects. The genetic polymorphisms of GSTM1 and GSTT1 were detected by multiple PCR method. Urinary inorganic arsenic (iAs), monomethylarsenic acid (MMA) and dimethylarsenic acid (DMA) concentrations were determined by ion chromatogram combined with HG-AFS. RESULTS: No significant differences in the relative proportion of urinary iAs, MMA and DMA were observed between the individuals with GSTT1 positive genotype and the individuals with GSTT1 null genotype. No significant differences in the relative proportion of urinary iAs, MMA and DMA were observed between the individuals with GSTM1 positive genotype and the individuals with GSTM1 null genotype. And no significant differences in the relative proportion of urinary iAs, MMA and DMA was observed among the individuals with different GSTM1 and GSTT1 associated genotype. CONCLUSION: The polymorphisms of GSTT1 and GSTM1 were not associated with arsenic metabolism level in the studied population.     

Biological monitoring of occupational exposure to inorganic arsenic

OBJECTIVES: This study was undertaken to assess reliable biological indicators for monitoring the occupational exposure to inorganic arsenic (iAs), taking into account the possible confounding role of arsenicals present in food and of the element present in drinking water. METHODS: 51 Glass workers exposed to As trioxide were monitored by measuring dust in the breathing zone, with personal air samplers. Urine samples at the end of work shift were analysed for biological monitoring. A control group of 39 subjects not exposed to As, and eight volunteers who drank water containing about 45 micrograms/l iAs for a week were also considered. Plasma mass spectrometry (ICP-MS) was used for the analysis of total As in air and urine samples, whereas the urinary As species (trivalent, As3; pentavalent, As5; monomethyl arsonic acid, MMA; dimethyl arsinic acid, DMA; arsenobetaine, AsB) were measured by liquid chromatography coupled with plasma mass spectrometry (HPLC-MS) RESULTS: Environmental concentrations of As in air varied widely (mean 84 micrograms/m3, SD 61, median 40) and also the sum of urinary iAs MMA and DMA, varied among the groups of exposed subjects (mean 106 micrograms/l, SD 84, median 65). AsB was the most excreted species (34% of total As) followed by DMA (28%), MMA (26%), and As3 + As5 (12%). In the volunteers who drank As in the water the excretion of MMA and DMA increased (from a median of 0.5 to 5 micrograms/day for MMA and from 4 to 13 micrograms/day for DMA). The best correlations between As in air and its urinary species were found for total iAs and As3 + As5. CONCLUSIONS: To avoid the effect of As from sources other than occupation on urinary species of the element, in particular on DMA, it is proposed that urinary As3 + As5 may an indicator for monitoring the exposure to iAs. For concentrations of 10 micrograms/m3 the current environmental limit for iAs, the limit for urinary As3 + As5 was calculated to be around 5 micrograms/l, even if the wide variation of values needs critical evaluation and application of data. The choice of this indicator might be relevant also from a toxicological point of view. Trivalent arsenic is in fact the most active species and its measure in urine could be the best indicator of some critical effects of the element, such as cancer.

 

     

外源性蛋氨酸对饮水砷暴露雌性小鼠体内砷形态分布的影响

目的 探讨外源性蛋氨酸(methionine,Met)对饮水砷暴露小鼠体内不同组织器官砷形态分布的影响.方法 将健康清洁级雌性昆明小鼠40只,随机分为对照组、单纯砷染毒组及低、中、高剂量Met与砷联合染毒组,每组8只.除对照组小鼠饮蒸馏水外,其余各组小鼠以自由饮水方式饮含50mg/L亚砷酸钠的水,连续染毒4周.在染毒的第4周,低、中、高剂量Met与砷联合染毒组小鼠分别被腹腔注射100、200、400 mg/kg的Met溶液,对照组和单纯砷染毒组小鼠被腹腔注射生理盐水,连续注射7 d.末次注射24 h后,处死小鼠,快速取血,分离肝和脑组织,分别检测无机砷(iAs)、一甲基胂酸(MMA)和二甲基胂酸(DMA)含量,并计算各组织中总砷含鼍(TAs)及砷一甲基化率(primary methylation ratio,PMR)和二甲基化率(secondary methylation ratio,SMR).结果 单纯砷染毒组和高、中、低剂量Met与砷联合染毒组小鼠肝、脑组织及全血中iAs、MMA、DMA和TAs含量均高于对照组,差异有统计学意义(P<0.05).与单纯砷染毒组比较,中、高剂量Met与砷联合染毒组小鼠肝组织中DMA含量和PMR较高,差异有统计学意义(P<0.05).与单纯砷染毒组比较,各剂量Met与砷联合染毒组小鼠全血中iAs、MMA和TAs含量均下降,差异有统计学意义(P<0.05).各剂量Met与砷联合染毒组小鼠脑组织中DMA和TAs含量低于单纯砷染毒组,差异有统计学意义(P<0.05).结论 外源性Met 对小鼠体内砷甲基化代谢具有促进作用,并可加速体内砷化物的排泄,从而减少血液和脑组织中的砷负荷.