Biological monitoring of dichloropropene: air concentrations, urinary metabolite, and renal enzyme excretion

Fifteen applicators of dichloropropene (DCP) were studied for personal air exposure to DCP, excretion of the metabolite of DCP (3CNAC), and excretion of the renal tubular enzyme, N-acetyl glucosaminidase (NAG). Each was studied for four 6-8 h consecutive intervals following baseline determinations of 3CNAC and NAG excretion. In accord with pilot data, 24-h urinary excretion of 3CNAC (mg) correlated well with exposure product for DCP (min exposed.mg/m3), r = 0.854, p less than .001. A more precise correlation of the air exposure product with urinary excretion of 3CNAC was discerned by using the morning urine after the previous day of exposure (micrograms/mg of creatinine), r = 0.914, p less than .001. Four workers had clinically elevated activity of NAG (greater than 4 mU/mg creatinine) in any of their urine collections after baseline. Nine workers showed greater than 25% increases in NAG excretion when compared to baseline. Dichloropropene air exposure products of greater than 700 mg.min/m3 or excretion of greater than 1.5 mg 3CNAC/d distinguished abnormally high daily excretion of NAG. These data demonstrate a firm positive relationship between air exposure and internal exposure, and a possible subclinical nephrotoxic effect in DCP workers.     

Effect of dietary calcium and phosphorus levels on the utilization of calcium,phosphorus, magnesium,manganese, and selenium by adult males

The effects of dietary calcium and phosphorus levels on the utilization of phosphorus, calcium, magnesium, manganese, and selenium by nine adult males were examined during a 39-day balance study. The dietary treatments were a moderate calcium-moderate phosphorus diet (MCaMP), a moderate calcium-high phosphorus diet (MCaHP), and a high calcium-high phosphorus diet (HCaHP). The moderate and high levels of phosphorus were 843 and 2443 mg daily, respecitvely; the moderate and high levels of calcium were 780 and 2382 mg daily, respectively. Subjects were unable to maintain positive balance in regard to phosphorus when fed the moderate level of phosphorus (MCaMP) but maintained positive balance in regard to phosphorus when fed the high level of phosphorus (MCaHP, HCaHP). The addition of more calcium to the high phosphorus diets resulted in significantly greater excretion of phosphorus in the feces but significantly less excretion of phosphorus in the urine by subjects. The dietary treatments affected urinary excretion of calcium, magnesium, and selenium significantly, but the effects were small or were compensated for by changes in fecal excretion of the minerals. Thus the dietary treatments had no significant effects on overall retention of calcium, magnesium, manganese, and selenium by these subjects.     

Zinc supplements and serum lipids in young adult white males

A 12-wk double-blind study was conducted to determine the effect of oral zinc supplementation upon serum total cholesterol, lipoprotein-cholesterol fractions, and serum triglycerides in white males. The subjects were randomly assigned to one of three treatment groups and consumed either a placebo tablet (n = 9), 50 mg Zn/d (n = 13), or 75 mg Zn/d (n = 9) as Zn gluconate. Serum total cholesterol, low-density-lipoprotein (LDL) cholesterol, very-low-density-lipoprotein (VLDL) cholesterol, and triglycerides were not affected by Zn supplements. However, serum high-density-lipoprotein (HDL)-cholesterol levels in subjects assigned to the 75 mg Zn/d group were significantly lower at weeks 6 and 12 than those for the placebo group and lower at weeks 6, 8, and 12 than at baseline; subjects assigned to the 50 mg Zn/d group had lower serum HDL-cholesterol levels at week 12 than did the placebo group and lower at week 12 than at base line.     

24 h尿钠、尿钾及钠钾比与微量白蛋白尿的关联分析

目的  分析我国普通人群24 h尿钠、尿钾以及钠钾比与微量白蛋白尿(microalbuminuria, MAU)的关系。方法  2018年在黑龙江省、河北省、四川省、湖南省、江西省、青海省的12个区县开展基线调查,采用问卷调查、体格测量以及24 h尿液收集的方法对抽取的18~75岁对象进行调查。采用多因素logistic回归分析模型分析24 h尿钠、尿钾以及钠钾比和MAU的相关性。结果  最后纳入分析的研究对象共2 604名,年龄为(47.32±12.78)岁,男性有1 287人(49.42%),MAU者共231人(8.87%)。24h尿量为(1 614.80±645.16)mL/d,尿钠为(193.07±78.87)mmol/d,尿钾为(40.18±16.59)mmol/d,钠钾比为(5.18±2.19)。随着24 h尿钠和钠钾比的增长,MAU的检出率均呈上升趋势(P_趋势 < 0.05)。多因素logistic回归分析模型分析结果显示,较高的24 h尿钠排泄量(Q5)与最低五分位数组(Q1)相比,MAU发生的风险增加(OR=2.211, 95% CI: 1.359~3.597)。较高的尿钠钾比水平(Q5)与最低五分位数组(Q1)相比,MAU发生的风险增加(OR=2.498,95% CI: 1.546~4.038)。结论  24 h尿钠、钠钾比与MAU的发生呈正向关联,而24 h尿钾与MAU的发生无关。     

Skin contamination,airborne concentrations,and urinary metabolite excretion of propoxur during harvesting of flowers in greenhouses

In eight greenhouses used for carnation culture, workers engaged in harvesting (n = 16), were monitored for dermal and respiratory exposure and urinary excretion of propoxur. Dermal exposure of hands and forearms was estimated from dislodgeable foliar residue, using a transfer factor (a measure of transfer of pesticides from leaves to the skin) and the total number of working hours. Total estimated dermal and respiratory exposure during harvesting ranged from 0.2 to 46 mg and from 3 to 278 μg, respectively. To study the relationship between external and internal exposure to propoxur, respiratory and dermal exposure levels were compared with the total amount of 2-isopropoxyphenol (IPP), the major metabolite of propoxur, excreted in urine in 24 hr. The Pearson correlation coefficient between dermal exposure and the total amount of excreted IPP was 0.95. A correlation coefficient of 0.84 was found between respiratory exposure and the amount of IPP excreted. The latter association was probably caused by the covariation of respiratory and dermal exposure levels (r = 0.85). Assuming negligible oral absorption, calculations indicated that dermal exposure could account for >80% of the amount of excreted IPP. On the basis of the amount of IPP excreted, there was no reason to suspect increased health risks for workers from exposure to propoxur during harvesting. © 1993 Wiley-Liss, Inc.     

电焊工人唾液锰和血清锰及尿锰的改变

目的 探讨唾液锰是否可作为锰接触的生物检测指标.方法 选择电焊锰作业工人49名,其中高浓度接触组21人、低浓度接触组28人,采用电感耦合等离子体质谱法(ICP-MS)测定唾液锰和血清锰,用石墨炉原子吸收分光光度法测定尿锰.结果 高浓度接触组的车间空气锰浓度达2.21 mg/m3,低浓度接触组为0.24 mg/m3.接触组的唾液锰和血清锰分别为(4.45±2.17)、(4.64±1.30)μg/L,均明显高于对照组[分别为(3.04±1.40)、(2.70±1.50)μg/L],差异有统计学意义(P＜0.01),尿锰略高于对照组,但差异无统计学意义(P＞0.05).高浓度接触组的唾液锰和血清锰升高者分别为85.71%和100.00%,升高均值为3.04和3.00μg/L;低浓度接触组的唾液锰和血清锰升高者为71.43%和89.29%,升高均值为1.04和1.40 μg/L.唾液锰和血清锰未见伴随工龄的升高趋势.结论 唾液锰与血清锰测定均可反映工人的近期锰接触状况,尿锰的变化不敏感.唾液锰测定方便、准确,可作为新的生物检测指标.     

Effect of altered feeding patterns on serum lipids and lipoproteins in adult males

Effects of a three meal per day versus a six meal per day feeding pattern on selected serum lipids and lipoproteins in 17 males were examined. After a two week acclimatization period, subjects were randomly assigned to one of two groups. Each group followed a three meal per day pattern for six weeks and a six meal per day pattern for another six weeks. Serum total cholesterol and LDL-cholesterol levels were not significantly affected by the altered feeding patterns. There was a significant decrease in the triglyceride levels of one group, but not the other, during the six meal per day pattern. For both groups the HDL-cholesterol levels differed significantly (P≤0.05) between the two feeding patterns. However, the findings were dissimilar in that for one group the HDL-cholesterol was higher after the six meal per day pattern and, for the other group, the opposite was true. Only during Phase I, the acclimatization period when both groups were consuming three meals per day, were any significant differences in dietary intakes noticed. Specifically, subjects in Group I consumed significantly more total fat and saturated fat (P=0.01 and P=0.04, respectively). Throughout the study there were no significant differences between the two groups relative to polyunsaturated to saturated fat (P/S) ratios of the diets.     

The effect of dietary caffeine on urinary excretion of calcium,magnesium, phosphorus,sodium, potassium,chloride and zinc in healthy males

Fifteen males drank decaffeinated coffee to which 0, 150 or 300 mg caffeine had been added. Each subject had fasted at least ten hours before drinking each of the three test beverages. Urine samples were collected at one, two and three hours after caffeine consumption. Total urinary three hour excretion of calcium, magnesium, sodium and chloride increased significantly after caffeine intake, while zinc, phosphorus, potassium, creatinine and volume were unchanged. The increased outputs were due to increased urinary mineral concentrations.     

Effect of dietary caffeine and theophylline on urinary calcium excretion in the adult rat

The chronic effects of dietary caffeine or theophylline on urinary calcium excretion were investigated in the adult male rat. When caffeine was added at two concentrations, 0.75 and 1.50 g/kg diet, 24-h urinary calcium excretion rose 300 and 450% on d 7, and 200 and 330% on d 14, respectively. There were no changes in the 24-h urinary excretion of phosphate, sulfate, sodium and cAMP nor did urine volume change. The high dose of caffeine was compared to an equimolar dose of theophylline (1.39 g/kg diet) in both Wistar and Sprague-Dawley rats. Urinary calcium excretion in theophylline-treated rats was significantly greater than in caffeine-treated rats on all sampling days and in both strains of rat; the calciuric effect lasted at least 22 d. When rats were given indomethacin (3.3 mg/kg diet) the calciuria induced by caffeine and theophylline was abolished, and sodium excretion in all groups was reduced by 35-50%, but urine volume was unchanged. The calciuria of methylxanthine feeding may result from a prostaglandin-mediated process distinct from diuresis.