Occupational exposure to airborne mercury during gold mining operations near El Callao, Venezuela

Objective: The National Institute for Occupational Safety and Health (NIOSH) recently conducted a cross–sectional study during gold mining operations near El Callao, Venezuela. The purpose of the study was to assess mercury exposures and mercury-related microdamage to the kidneys. The study consisted of concurrent occupational hygiene and biological monitoring, and an examination of the processing techniques employed at the different mining facilities. Mercury was used in these facilities to remove gold by forming a mercury-gold amalgam. The gold was purified either by heating the amalgam in the open with a propane torch or by using a small retort. Methods: Thirty-eight workers participated in this study. Some participants were employed by a large mining company, while others were considered “informal miners” (self-employed). Mercury exposure was monitored by sampling air from the workers' breathing zones. These full-shift air samples were used to calculate time-weighted average (TWA) mercury exposure concentrations. A questionnaire was administered and a spot urine sample was collected. Each urine sample was analyzed for mercury, creatinine, and N-acetyl-ß-d-glucosaminidase (NAG). Results: The range for the 8-h TWA airborne mercury exposure concentrations was 0.1 to 6,315?μg/m³, with a mean of 183?μg/m³. Twenty percent of the TWA airborne mercury exposure measurements were above the NIOSH recommended exposure limit (REL) of 50?μg/m³, and 26% exceeded the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) of 25?μg/m³. The mean urine mercury concentration was 101?μg/g creatinine (μg/g-Cr), and the data ranged from 2.5 to 912?μg/g-Cr. Forty–two percent of the study participants had urine mercury concentrations that exceeded the ACGIH biological exposure index (BEI) of 35?μg/g-Cr. Urinary NAG excretion is considered a biological marker of preclinical, nonspecific microdamage to the kidney's proximal tubule cells. The mean urine NAG concentration was 3.6 International Units/g-Cr (IU/g-Cr) with a range of 0.5 to 11.5?IU/g-Cr. Three workers had urine NAG levels in excess of the reference values. Correlation analyses found statistically significant correlations between airborne mercury exposure and urine mercury level (P=0.01), and between urine mercury level and urine NAG excretion (P=0.01). In addition, the airborne mercury exposure data and urine mercury data were segregated by job tasks. A Wilcoxon rank sum test revealed significant correlations between tasks and mercury exposure (P=0.03), and between tasks and urine mercury level (P=0.02). Conclusions: The tasks with the highest mean airborne mercury exposures were “burning the mercury-gold amalgam” and “gold refining/smelting”. Recommendations were provided for improving the retort design to better contain mercury, for ventilation in the gold shops, and for medical surveillance and educational programs.     

Influence of renal compensatory hypertrophy on mitochondrial energetics and redox status

A reduction in functional renal mass is common in numerous renal diseases and aging. The remaining functional renal tissue undergoes compensatory growth primarily due to hypertrophy. This is associated with a series of physiological, morphological and biochemical changes similar to those observed after uninephrectomy. Previous work showed that compensatory renal cellular hypertrophy resulted in an increase in susceptibility to several drugs and environmental chemicals and appeared to be associated with oxidative stress. Compensatory renal cellular hypertrophy was also associated with increases in mitochondrial metabolic activity, uptake of glutathione (GSH) across renal plasma and mitochondrial inner membranes, and intracellular GSH concentrations. Based on these observations, we hypothesize that the morphological, physiological and biochemical changes in the hypertrophied kidney are associated with marked alterations in renal cellular energetics, redox status and renal function in vivo. In this study, we used a uninephrectomized (NPX) rat model to induce compensatory renal growth. Our results show alterations in renal physiological parameters consistent with modest renal injury, altered renal cellular energetics, upregulation of certain renal plasma membrane transporters, including some that have been observed to transport GSH, and evidence of increased oxidative stress in mitochondria from the remnant kidney of NPX rats. These studies provide additional insight into the molecular changes that occur in compensatory renal hypertrophy and should help in the development of novel therapeutic approaches for patients with reduced renal mass.     

肾小管损伤因子在糖尿病高滤过患者中的水平变化

目的探讨肾小管损伤因子与2型糖尿病（T2DM）肾小球高滤过（GHF）的关系。方法以基于光抑素C（CysC）的Macisaac方程式估算肾小球滤过率（eGFR）,筛选T2DM患者高滤过组30例及正常滤过组58例,并设健康对照组24例。常规方法测定肌酐、CysC、血糖、糖化血红蛋白等含量,EEISA及比浊法分别检测肾小管损伤因子NGAL、KIM-1、NAG等的水平。多因素分析各指标与高滤过组eGFR的相关性。结果高滤过组尿液NGAL、KIM-1水平均显著高于其他两组,而血浆NGAL含量却显著降低（均P〈0．05）,尿液NAG水平在三组中差异无统计学意义。相关分析显示高滤过组eGFR与空腹血糖（r=0．250）、糖化血红蛋白（r=0．237）、尿液NGAL（r=0．388）,KIM-1（r=-0．470）等成正相关,与血浆NGAL（r=-0．159）成负相关。结论尿液肾小管损伤因子在DM高滤过组的高水平表达,说明GHF可能直接导致肾小管早期损伤。     

益肾运脾逐瘀方对慢性肾炎患者血肌酐及尿蛋白的影响

目的:观察益肾运脾逐瘀方对慢性肾炎患者血肌酐及尿蛋白的影响。方法:选取本院2013年1月—2014年12月门诊或住院治疗的慢性肾炎患者60例,随机分为对照组和治疗组,每组30例。对照组予颉沙坦、盐酸贝那普利口服治疗,治疗组在对照组基础上加用中药益肾运脾逐瘀方治疗。两组均3个月为1个疗程,1个疗程后比较疗效和尿蛋白、尿NAG酶、血肌酐、尿素氮水平。结果:对照组有效率为80.00%,治疗组有效率为93.33%,治疗组优于对照组(P0.05);治疗组治疗后尿蛋白、尿NAG酶水平优于对照组(P0.05)。结论:益肾运脾逐瘀方治疗慢性肾炎疗效显著,能明显改善患者尿蛋白、尿NAG酶水平。     

Botany,phytochemistry, pharmacology,and potential application of Polygonum cuspidatum Sieb.et Zucc.: A review

Ethnopharmacological relevance

Polygonum cuspidatum Sieb. et Zucc. (Polygonum cuspidatum), also known as Reynoutria japonica Houtt and Huzhang in China, is a traditional and popular Chinese medicinal herb. Polygonum cuspidatum with a wide spectrum of pharmacological effects has been used for treatment of inflammation, favus, jaundice, scald, and hyperlipemia, etc.

Aim of the review

The present paper reviews the traditional applications as well as advances in botany, phytochemistry, pharmacodynamics, pharmacokinetics and toxicology of this plant. Finally, the tendency and perspective for future investigation of this plant are discussed, too.

Materials and methods

A systematic review of literature about Polygonum cuspidatum is carried out using resources including classic books about Chinese herbal medicine, and scientific databases including Pubmed, SciFinder, Scopus, the Web of Science and others.

Results

Polygonum cuspidatum is widely distributed in the world and has been used as a traditional medicine for a long history in China. Over 67 compounds including quinones, stilbenes, flavonoids, counmarins and ligans have been isolated and identified from this plant. The root of this plant is used as the effective agent in pre-clinical and clinical practice for regulating lipids, anti-endotoxic shock, anti-infection and anti-inflammation, anti-cancer and other diseases in China and Japan.

Conclusion

As an important traditional Chinese medicine, Polygonum cuspidatum has been used for treatment of hyperlipemia, inflammation, infection and cancer, etc. Because there is no enough systemic data about the chemical constituents and their pharmacological effects or toxicities, it is important to investigate the pharmacological effects and molecular mechanisms of this plant based on modern realization of diseases’ pathophysiology. Drug target-guided and bioactivity-guided isolation and purification of the chemical constituents from this plant and subsequent evaluation of their pharmacologic effects will promote the development of new drug and make sure which chemical constituent or multiple ingredients contributes its pharmacological effects. Additionally, chemicals and their pharmacological effects of the other parts such as the aerial part of this plant should be exploited in order to avoid resource waste and find new chemical constituents.     

100例老年人尿NAG、尿沉渣定量检测结果分析

通过对老年人进行尿NAG和沉渣定量检测,经统计分析老年人尿NAG与对照成年组、儿童组比较(P<0.05),有显著意义,尿NAG属于细胞内溶酶体酶,主要来源于肾,特别是肾单位、近曲小管上皮细胞是一种灵敏的肾小管标志物,认为NAG活性增高与年龄增大,肾单位数减少,机能减退有一定的相关性.男性老年组尿沉渣红细胞、白细胞计数与对照成青年组、儿童组比较(P>0.05);女性老年组尿沉渣红细胞、白细胞与对照青年组、儿童组比较(P>0.05)均无显著意义.尿沉渣离心浓缩后滴入血细胞池内计数,再换算成每升的数量使其量化,建立老年人尿沉渣血细胞及NAG正常参考范围对泌尿系疾病的诊断及疗效监测有一定的实际意义.     

Influence of pigments and pH of urine on the determination of N-acetyl-beta-D-glucosaminidase activity with 2-methoxy-4-(2'-nitrovinyl)-phenyl-N-acetyl-beta-D-glucosaminide

The influence of urinary pigments and urine pH on the spectrophotometric determination of N-acetyl-beta-D-glucosaminidase (NAG; EC 3.2.1.30) activity with 2-methoxy-4-(2'-nitrovinyl)-phenyl-N-acetyl-beta-D-glucosaminide as a substrate was studied. The investigation was performed with human and rabbit urine samples. It was found that alkaline urine pH values influenced NAG activity in two ways: 1) NAG activity decreased due to enzyme instability with pH increase, and 2) NAG activity increased because of the contribution of urinary pigments to absorbance of 2-methoxy-4-(2'-nitrovinyl)-phenol (MNP) at 505 nm. It was shown that besides the maximum (I) in the range of 350-360 nm of the absorption spectra of alkaline urine, there was a maximum (II) in the range of 380-460 nm. With the increase of pH, maximum II was shifted toward higher wavelengths and contributed to MNP absorption (5-90%). On the other hand, the maximum of MNP absorption was shifted toward lower wavelengths (495-400 nm) with increasing pH. Two procedures to eliminate the influence of urinary pigments are presented. The justification of applying a correction to the values of NAG activity in human and rabbit urine (a model system for studying the toxic effects of cadmium) was discussed.     

铅性肾损害效应生物标志物β2-MG、NAG、RBP的相关影响因素研究

目的研究β2-MG、NAG、RBP在铅性肾损害评价中的影响因素。方法采用相关分析或分组比较法。结果β2-MG、NAG、RBP与年龄、接铅工龄呈明显正相关（r依序为：0．221、0．230、0．433,0．359、0．419、O．365）,β2-MG、RBP与血铅呈明显正相关（r依序为：O．419、0．354）;另外三个指标间也有明显相关关系。结论应用RBP、β2-MG、NAG评价铅性肾损害时,应注意个体的年龄、接铅工龄的影响,并注意与血铅及其各指标间的相互关系。     

Evaluation of a synchronous twin-pulse technique for shock wave lithotripsy: a prospective randomized study of effectiveness and safety in comparison to standard single-pulse technique

OBJECTIVE

To asses the efficacy and safety of bidirectional synchronous twin‐pulse extracorporeal shock wave lithotripsy (ESWL) compared with standard ESWL.

PATIENTS AND METHODS

Between March 2003 and December 2006, 240 patients with a radio‐opaque single renal stone of ≤25 mm were randomized to treatment either by the Twinheads (TH) lithotripter (FMD, Lorton, Virginia, USA) or the Dornier Lithotripter S (DLS, Dornier MedTech Europe GmbH, Germering, Germany). Before and after ESWL, urinary N‐acetyl‐B‐glucosaminidase (NAG) levels were assessed and patients were evaluated with dynamic MRI. The efficacy and complications were compared, with success defined as no residual fragments.

RESULTS

For stones of >10 mm the rate for the failure of disintegration was 13.3% for the DLS vs 1.4% for the TH (P = 0.009). For stones of ≤10 mm the stone‐free rate was 74.4% for the TH vs 67.7% for the DLS (P = 0.6), while for stones of >10 mm it was 78.1% and 66.7%, respectively (P = 0.14). The median (range) number of sessions in both groups was 2 (1–5). After ESWL urinary NAG levels were increased significantly in both groups; in the TH group it declined below the level before ESWL after 2 days, while in the DLS group it remained high after 7 days. In the DLS group four patients developed subcapsular or parenchymal haematoma after ESWL, vs none in the TH group. There was loss of corticomedullary differentiation after ESWL in three patients in the DLS group and only one in the TH group. In the DLS group there was a statistically significantly decrease in bilateral renal perfusion after ESWL, but no changes in the TH group.

CONCLUSIONS

Synchronous twin‐pulse ESWL has clinical advantages over standard ESWL in terms of safety and efficacy.     

N-乙酰-β-D-氨基葡萄糖苷酶活性测定在糖尿病微血管病变诊断中的临床意义

检测了57例糖尿病患者和83例正常对照者的血、尿N-乙酰-β-D-氨基葡萄糖苷酶(NAG)活性。发现糖尿病患者NAG活性显著高于对照组(P＜0.01)，与同时测定的血糖、糖化血红蛋白(HbA_(1c))、尿白蛋白呈显著正相关(P均＜0.01)，治疗后随血糖下降尿NAG活性降低，但有微血管病变组仍显著高于正常对照组。提示NAG活性是反映糖尿病性微血管病变程度的一项指标。