Oxidative ability and toxicity of n-hexane insoluble fraction of diesel exhaust particles.

Diesel exhaust particles (DEP) are known to induce adverse biological responses such as inflammation of the airway. However, the relationship between the chemical characteristics of organic compounds adsorbed on DEP and their biological effects is not yet fully understood. In this study, the dichloromethane-soluble fraction (DMSF) from DEP was fractionated into its n-hexane-soluble fraction (n-HSF) and n-hexane-insoluble fraction (n-HISF). Using these DEP fractions, we designed the present studies to elucidate (1) chemical characteristics, (2) biological characteristics, and (3) the relationship between the chemical and the biological characteristics of these DEP fractions. Dithiothreitol (DTT) assay, Fourier transform-infrared (FT-IR) spectroscopy, proton nuclear magnetic resonance (1H-NMR) spectroscopy, and gas chromatography-mass spectrometry (GC-MS) were used to characterize their chemical properties. Heme oxygenase-1 (HO-1) protein expression, viability of rat alveolar type II epithelial cell line (SV40T2), and inflammatory cell infiltration into the peritoneal cavity of BALB/c mice were evaluated as markers of oxidative stress, cytotoxicity, and inflammatory response, respectively. The oxidative ability of the DEP fractions was n-HISF > DMSF > n-HSF. IR, 1H-NMR, and GC-MS spectra showed that n-HISF was mainly composed of compounds having many functional groups related to oxygenation, such as hydroxyl and carbonyl groups. The relative strength of HO-1 protein expression, cytotoxicity, and inflammatory responses was also n-HISF > DMSF > n-HSF. All of the n-HISF-induced biological activities were decreased by reduction with N-acetyl-L-cysteine (NAC). These results suggest that n-HISF has high oxidative ability and many functional groups related to oxygenation and that this ability strongly contributes to the induction of oxidative stress, cytotoxicity, and inflammatory response.     

苦针汤的组方研究

目的：对苗药苦针汤进行组方基础研究和新药开发研究。方法：以该方对金黄色葡萄球菌、痢疾杆菌、白色葡萄球菌、致病性大肠杆菌（1）的抑制作用为考察指标，运用混料均匀设计法将组成苦针汤中的4味药配制成12种不同比例的复方，通过抗菌实验，测试用药抗菌能力。结果：建立回归方程．对回归方程及其中各项系数进行检验，求抗菌效果最佳时的变量取值。结论：回归方程通过检验，有意义、可用；苦参、黄芩对抑菌效果的贡献不显著，其余两味药以19．56g和11．84g组方时抗菌效果最佳，优于理论计算值。     

常规动力潜艇舱室空气组分容许浓度

潜艇潜航时舱室大气是一个综合性的密闭环境，其舱室空气中污染物多达数百种。消除或降低其浓度以达到安全水平是关系到艇员健康和潜艇战斗力的重要问题。本文介绍了本标准的意义，适用范围，主要技术参数及其确定依据，并与国外同类标准进行了比较。     

Chromate allergy from 'antifreeze-antiboil'

A diesel mechanic developed hand dermatitis after more than 3 years in the trade. Patch testing showed positive reactions to chromate and cobalt. Potassium dichromate is added to antifreeze-antiboil as a corrosion inhibitor.     

Immunohistological study for estrogenic activities of nitrophenols in diesel exhaust particles

We recently isolated 3-methyl-4-nitrophenol (4-nitro-m-cresol; PNMC) and 4-nitro-3-phenylphenol (PNMPP) from diesel exhaust particles (DEP) and identified them as vasodilators and xenoestrogens. The estrogenic activity of PNMC and PNMPP was further examined by using immunohistochemical staining of proliferating cell nuclear antigen (PCNA) in uterine luminal epithelium of ovariectomized 25-d-old immature female rats injected with PNMC and PNMPP subcutaneously for 2 d. Significant increases were observed in uterine luminal epithelium in PCNA positive cells of animals receiving 10 and 100 mg/kg PNMC and 0.1 mg/kg PNMPP compared with controls. These results clearly show the estrogenic activity of PNMC and PNMPP by cell proliferation on the uterine luminal epithelium.     

Multiple myeloma and diesel and other occupational exposures in swedish construction workers

We examined the relationships between occupational exposures and the risk of multiple myeloma among male construction workers in Sweden. A total of 446 myeloma subjects were identified among 365,424 male workers followed from 1971 to 1999. Occupational exposure was assessed using a semiquantitative job-exposure matrix, based on a survey carried out by the Construction Industry's Organization for Working Environment, Occupational Safety and Health in Sweden. Rate ratios (RRs) in the exposed groups relative to the unexposed groups were estimated by Poisson regression. We found an increased risk (RR = 1.3, 95% CI 1.04-1.71) among construction workers exposed to diesel exhaust. Adjustment for other occupational exposures did not change this estimate (RR = 1.3, 95% CI 1.00-1.77). However, there was no monotonic increase in risk with estimated level of exposure (RR for low = 1.4, moderate = 1.1, high = 1.4). There was no evidence of increased risk associated with the other occupational exposures among these construction workers, including asbestos, asphalt, cement dust, metal dust, mineral wool, organic solvents, stone dust and wood dust. Occupational exposure to diesel exhaust in the Swedish construction industry may present a small risk of multiple myeloma, but lack of an exposure-response trend tempers our ability to draw clear conclusions.     

Activation of 3-nitrobenzanthrone and its metabolites by human acetyltransferases,sulfotransferases and cytochrome P450 expressed in Chinese hamster V79 cells

3-nitrobenzanthrone (3-NBA) is a potent mutagen and suspected human carcinogen identified in diesel exhaust and ambient air pollution. 3-aminobenzanthrone (3-ABA), 3-acetylaminobenzanthrone (3-Ac-ABA) and N-acetyl-N-hydroxy-3-aminobenzanthrone (N-Ac-N-OH-ABA) have been identified as 3-NBA metabolites. Recently we found that 3-NBA and its metabolites (3-ABA, 3-Ac-ABA and N-Ac-N-OH-ABA) form the same DNA adducts in vivo in rats. In order to investigate whether human cytochrome P450 (CYP) enzymes (i.e., CYP1A2), human N,O-acetyltransferases (NATs) and sulfotransferases (SULTs) contribute to the metabolic activation of 3-NBA and its metabolites, we developed a panel of Chinese hamster V79MZ-h1A2 derived cell lines expressing human CYP1A2 in conjunction with human NAT1, NAT2, SULT1A1 or SULT1A2, respectively. Cells were treated with 0.01, 0.1 or 1 microM 3-NBA, or its metabolites (3-ABA, 3-Ac-ABA and N-Ac-N-OH-ABA). Using both enrichment versions of the (32)P-postlabeling assay, nuclease P1 digestion and butanol extraction, essentially 4 major and 2 minor DNA adducts were detected in the appropriate cell lines with all 4 compounds. The major ones were identical to those detected in rat tissue; the adducts lack an N-acetyl group. Human CYP1A2 was required for the metabolic activation of 3-ABA and 3-Ac-ABA (probably via N-oxidation) and enhanced the activity of 3-NBA (probably via nitroreduction). The lack of acetylated adducts suggests N-deacetylation of 3-Ac-ABA and N-Ac-N-OH-ABA. Thus, N-hydroxy-3-aminobenzanthrone (N-OH-ABA) appears to be a common intermediate for the formation of the electrophilic arylnitrenium ions capable of reacting with DNA. Human NAT1 and NAT2 as well as human SULT1A1 and SULT1A2 strongly contributed to the high genotoxicity of 3-NBA and its metabolites. Moreover, N,O-acetyltransfer reactions catalyzed by human NATs leading to the corresponding N-acetoxyester may be important in the bioactivation of N-Ac-N-OH-ABA. As human exposure to 3-NBA is likely to occur primarily via the respiratory tract, expression of CYPs, NATs and SULTs in respiratory tissues may contribute significantly and specifically to the metabolic activation of 3-NBA and its metabolites. Consequently, polymorphisms in these genes could be important determinants of lung cancer risk from 3-NBA.     

Diesel motor emissions and lung cancer mortality—Results of the second follow‐up of a cohort study in potash miners

International health authorities have graded diesel motor emissions (DME) as probably cancerogenic in human beings. There are gaps in epidemiological evidence regarding exact exposure quantification, confounder control and the investigation of highly exposed populations. We investigated the association of DME and lung cancer mortality in a historical cohort study of 5,862 German potash miners who were followed from 1970 to 2001. Cumulative exposure (CE) was measured by representative concentrations of total carbon multiplied with exposure years from the mines' medical records. Exposure and smoking behavior were validated by interviews of 3,087 participants. We computed standardized mortality ratios (SMR, external comparison) and performed Cox regression (internal comparison). The relative risk estimates (RR) with 95%‐confidence intervals were adjusted for age and smoking. Vital status and causes of death were confirmed for 98.1% of participants. Sixty‐one lung cancer deaths occurred. SMR‐analysis showed lower than expected lung cancer mortality (healthy‐worker‐effect). Internal comparisons revealed risk elevations from moderate to risk doubling depending on the exposure categories used (dichotomized: up to RR 1.43[0.67–3.03] for a CE of 4.90[mg/m³]*years as compared with less exposure; quintiles: RR 1.13[0.46–2.75], 2.47[1.02–6.02], 1.50[0.56–4.04] and 2.28[0.87–5.97] for a CE up to 2.04, 2.73, 3.90 and >3.90, respectively, as compared with the reference of <1.29[mg/m³]*years). Additional adjustment of length of follow‐up leads to further RR increases and indicates healthy‐worker‐survivor‐phenomena. The analyses of a sub‐cohort (n = 3,335) with particularly accurate exposure measurement revealed a nonsignificant dose‐response‐relationship. Our results support an association of DME and lung cancer mortality. © 2008 Wiley‐Liss, Inc.     

手持式工作能力测试仪的设计和制作

介绍了一种手持式工作能力测试仪。定义了工作能力指数的计算方法,整个软件用汇编语言编程。主要对舰艇工作人员和出租汽车司机进行实验测试,获得满意效果。整个测试过程可以由被测试者自己单独、快速地完成。