苯系混合物对女性生殖机能影响的研究

对接触苯系混合物的女工１９９人和对照组女工２０５人的月经状况、妊娠经过及妊娠结局进行了调查，应用回顾性队列研究方法分析，结果表明，接触苯系混合物女工的月经周期异常、经期异常、经量过多、痛经、自然流产、妊娠剧吐、妊高征、早产等的发生率均高于对照组（Ｐ＜０．０５）。     

Evaluating the NMDA-glutamate receptor as a site of action for toluene, in vivo.

Acute exposure to toluene and other volatile organic solvents results in neurotoxicity characterized by nervous system depression, cognitive and motor impairment, and alterations in visual function. In vitro, toluene disrupts the function of N-methyl-D-aspartate (NMDA)-glutamate receptors, indicating that effects on NMDA receptor function may contribute to toluene neurotoxicity. NMDA-glutamate receptors are widely present in the visual system and contribute to pattern-elicited visual-evoked potentials (VEPs) in rodents, a measure that is altered by toluene exposure. The present study tested the hypothesis that effects on NMDA receptors contribute to toluene-induced alterations in pattern-elicited VEPs. Prior to examining the effects of NMDA receptor agonists and antagonists on toluene-exposed animals, a dose-range study was conducted to determine the optimal dose for NMDA (agonist) and MK801 (antagonist). Dose levels of 2.5 mg/kg NMDA and 0.1 mg/kg MK801 were selected from these initial studies. In the second study, Long-Evans rats were exposed to toluene by inhalation, and VEPs were measured during toluene exposure in the presence or absence of NMDA or MK801. Pattern-elicited VEPs were collected by exposing rats to a sinusoidal pattern modulated at a temporal frequency of 4.55 Hz. Following collection of baseline VEPs, rats were injected with either saline, NMDA (2.5 mg/kg, ip), or MK801 (0.1 mg/kg, ip) and 10 min later were exposed to air or toluene (2000 ppm). VEP amplitudes were calculated for 1x (F1) and 2x stimulus frequency (F2). The F2 amplitude was reduced by approximately 60, 60, and 50% in the toluene-exposed groups (TOL): SALINE/TOL (n = 11), NMDA/TOL (2.5 mg/kg; n = 13), and NMDA/TOL (10 mg/kg, n = 11), respectively. Thus, NMDA (2.5 and 10 mg/kg) did not significantly affect toluene-mediated F2 amplitude effects. Administration of 0.1 mg/kg MK801 prior to toluene exposure blocked the F2 amplitude decreases caused by toluene (n = 9). However, when 0.1 mg/kg MK801 was administered 20 min after the onset of toluene exposure, toluene-mediated F2 amplitude decreases persisted despite the challenge by MK801. These data support the hypothesis that acute actions of toluene on pattern-elicited VEPs involve NMDA receptors.     

Patch testing with p-toluene diamine preparations of different ages

Analyses of the stability of 1% p-toluene diamine (PTD) in petrolatum used for patch testing showed a rapid decline of the PTD concentration down to 0.1%, possibly due to the generation of dye complexes. To study whether the diagnostic quality of this test preparation is compromised by the chemical reactions taken place, a multicentre study was conducted by the German Contact Dermatitis Research Group (DKG), comparing patch test results in 177 patients with simultaneously tested PTD preparations of different ages. During the 10-month course of this study, the age of the batches ranged from 2 to 11 months for batch A, from 7 to 16 months for batch B and from 11 to 20 months for batch C. There were no statistically significant differences between reactions to batches A and B, A and C, and B and C. Agreement of patch test reactions to the 3 batches was very good and comparable to the general reproducibility of patch test with standard allergens. The chemical reactions mentioned above apparently do not affect the diagnostic quality of PTD patch test preparations because the true allergen probably is not PTD itself, but one or more of the reaction products.     

Change in permeation parameters and the decontamination efficacy of three chemical protective gloves after repeated exposures to solvents and thermal decontaminations

BACKGROUND: Chemical protective clothing (CPC) and gloves, which provide adequate protection, are usually too expensive to be considered disposable. Repeated use of CPC without effective decontamination may result in secondary exposure and injury. However, decontamination may change the physical and/or chemical properties of the barrier material, causing variations in breakthrough time (BT) and steady-state permeation rate (SSPR). METHODS: Glove materials including neoprene, Guardian butyl rubber, and nitrile synthetic rubber were selected for this study. Toluene and acetone were chosen as the challenge chemicals. Permeation was measured in a closed loop system using a 2.5 cm permeation cell and a MIRAN infrared analyzer (Foxboro, MA). Following the permeation test, the samples were thermally decontaminated. After each exposure/decontamination cycle, BT and SSPR were measured. A total of 260 permeation tests were conducted. Permeation test results were collected on each material/chemical combination for up to 10 exposure/decontamination cycles. RESULTS: On average, changes in BT and SSPR in comparison with respect to new swatches were 11.5% and 13.7% after seven exposure/decontamination cycles. The percentages increased to 26.6% and 15.9% after 10 exposure/decontamination cycles, respectively. For at least seven cycles, the BT mean for four out of five material/chemical combinations tested (neoprene/acetone, neoprene/toluene, nitrile/acetone, and nitrile/toluene) was not significantly different from the original value of the BT for each corresponding swatch. Similarly, the SSPR mean for each of the five material/chemical combinations after at least five cycles was not significantly different from those for new swatches. The BT mean for the butyl/toluene combination, however, was significantly different from the new swatches even after the first exposure/decontamination. The SSPR mean was significantly different after five cycles compared to the new swatches. CONCLUSIONS: Except for the butyl/toluene combination, thermal decontamination was an effective method in removing the solvents from the matrix of selected glove materials. Multiple reuses of some chemical protective gloves could be safe if effective decontamination methods are used and the glove materials do not have significant degradation.     

Evaluation of the exposure to organic solvent mixture

Summary A comparative study was conducted in a printing plant regarding various methods of measuring environmental concentrations of a solvent vapour mixture, the major components of which were n-hexane, ethyl acetate and toluene. Introduction of a portable gas-liquid chromatograph made it possible to analyze spot-air samples at the site of the exposure, and thereby obtain immediate information on its quality and quantity. The results were compared with those from personal sampling and continuous stationary sampling coupled with gas-liquid chromatographic analysis well as detection tube methods. Spot-air, personal and continuous stationary sampling methods were in good parallel while the detection tube method was less valid in the case of vapour mixture exposure. Studies on toluene metabolism revealed that the biological half-life of toluene was about 7.5 hrs and that the metabolism was not significantly disrupted by the co-presence of other solvents such as ethyl acetate and n-hexane.This work was supported in part by a research grant from the Fujiwara Memorial Foundation, and presented at the 47th Annual Meeting of the Japanese Association of Industrial Health, Nagoya, Japan, March 29–31, 1974.     

Enzyme immunoassay of bradykinin using β-d-galactosidase as a labeling enzyme

An enzyme immunoassay of bradykinin, using β-d-galactosidase from Escherichia coli as a labeling enzyme, is described. Bradykinin, conjugated to the enzyme with a hetero bifunctional type of coupling agent, N-(m-maleimidobenzoyloxy)succinimide, was prepared as a labeled antigen, Antisera against bradykinin were obtained from male rabbits immunized with bradykinin linked to albumins (ovalbumin or bovine serum albumin) with toluene 2,4-diisocyanate or l-ethyl-3-(3-dimethylaminopropyl) carbodiimide. These antisera were tested for their abilities to bind the labeled antigen and for their sensitivities. The antigen-antibody reaction was performed in an ice bath for 18 hr; this was incubated for another 4 hr, after addition of anti-rabbit IgG antiserum from goat (double antibody method) to separate the bound antigen from free antigen; the enzyme activity in the precipitate was measured with a fluorogenic substrate. Some of the antisera showed good sensitivity when assayed by this method, the sensitivity having been comparable to that of radioimmunoassays of bradykinin. With this method, 30 pg/tube (0.2 ml) of bradykinin could be measured, and the standard curve was obtained in the range of 30 pg to 10 ng of bradykinin. The kininogen level in human plasma was determined by conversion of kininogen to bradykinin by trypsin after heating plasma at 60°. Kininogen levels obtained from six human subjects were in good agreement with those obtained by bioassay.     

D-101型大孔吸附树脂预处理方法的研究

目的建立D-101型大孔吸附树脂的预处理方法。方法采用正交试验设计以洗脱液中甲苯、萘的量及其紫外吸收值为指标(254 nm),考察了D-101型大孔吸附树脂预处理过程中的影响因素。结果溶剂和温度是树脂预处理中两个关键因素。建立了D-101型大孔吸附树脂预处理的优选工艺为柱温为60℃,先用2%N aOH浸泡洗脱,再用乙醇浸泡洗脱,洗脱体积流量为2 BV/h,乙醇用量为3.5倍柱体积(BV),此时乙醇洗脱溶液的吸光度约为0.4。结论该D-101型大孔吸附树脂的预处理工艺简单、生产周期短、环境污染小且预处理过程可用UV在线监测。     

Effect of Chronic Inhalation of Toluene and Dioxane on Activity of Free Radical Processes in Rat Ovaries and Brain

The effects of toluene and dioxane inhalations on the intensity of free radical oxidation in rat ovaries and brain cortex were studied. Both toxins in a dose 10-fold surpassimg the maximum permissible concentration increased activity of glutathione peroxidase in brain tissue; moreover, toluene increased chemiluminescence intensity, which attested to activation of free radical processes. In ovarian tissue toluene increased activities of glutathione peroxidase and catalase and the intensity of lipid peroxidation. These changes were associated with the appearance of normally absent circadian rhythm.     

Reference values for blood toluene in the occupationally nonexposed general population

Summary Blood toluene was measured by gas chromatography — mass spectrometry in 232 occupationally nonexposed subjects, consisting of 126 rural and 106 urban workers, and 37 chemical workers. Mean blood toluene was significantly lower in rural (698 ng/l) and urban workers (984 ng/l) than in chemical workers (2789 ng/l). Blood toluene was not significantly different between the rural and urban workers or among the urban workers with different jobs. Smokers had significantly higher levels (median 606 ng/l) than nonsmokers (median 424 ng/l). Subjects who had smoked at least one cigarette in the last 2 h before blood sampling had significantly higher blood toluene (median 1170 ng/1) than those who had not smoked during this time (median 693 ng/l), for whom the level was not significantly different from that in nonsmokers. Blood toluene in the total population was less than 2863 ng/l in 95% cases.