Heart rate variation and serum dopamine-beta-hydroxylase activity in workers exposed to vibration

Tests of autonomic nervous function were conducted on 38 workers who had been exposed to vibration [16: VWF(+) group, 22: VWF(-) group, VWF: vibration-induced white finger] and 17 workers who had not been exposed to vibration (control group). Measurements were made of R-R interval variation of the electrocardiogram at rest and during deep breathing, and serum dopamine-beta-hydroxylase (DBH) activity during an immersion test of the hand in 10 degrees C water. Heart-rate variation related to respiratory arrhythmia indicates parasympathetic activity, and serum DBH activity is regarded as an indicator of sympathetic activity. The variations in the R-R interval during deep breathing were smallest in the VWF(+) group, followed by the VWF(-) group (P less than 0.05 and P less than 0.01, compared with the control group). The DBH activity of the VWF(+) group was larger than those of the VWF(-) group and the control group, however, the differences were small and not statistically significant. The reduced R-R interval variations in the VWF(+) and the VWF(-) groups support the hypothesis that autonomic nervous function can be affected by exposure to vibration. The change of DBH activity induced by cold exposure may be an unsuitable index of sympathetic tone. Further study of the autonomic nervous function in workers with vibration syndrome is recommended.     

Free radicals: important cause of pathologies refer to ageing

Free radical are highly reactive chemical species with an unpaired electron in an atomic or molecular orbital. In biological systems, the most important free radicals are superoxide anion and hydrogen peroxide; in the presence of transition metals such as iron, copper and manganese both these free radicals produce hydroxyl radicals. Free radicals attack proteins, nuclei acids and membranes containing large quantities of polyunsaturated fatty acids. Because of their toxicity, the organism has developed ways to deactivate them. The superoxide dismutase enzyme (SOD) catalyzes dismutation of the superoxide radical into hydrogen peroxide and oxygen hydrogen peroxide is in turn reduced to water and oxygen by peroxidase glutathione and catalase enzymes. The production of radicals in the brain is due to catecholamine metabolism such as dopamine and norepinephrine and is increased by the presence of transition metals and by a deficiency of antioxidant agents such as vitamin E. Two main groups of dementia exist in older age: the multi-infarctual dementias, caused by cerebrovascular disorders and the primary degenerative disorders such as Alzheimer, where no vascular disease is evident. Free radicals play an important role in Parkinson's disease, in Alzheimer's disease and in stroke. The value of SOD and CAT activity following the above mentioned degenerative diseases differ among the various studies carried out. In Alzheimer's disease, the value of SOD activity probably increases in the neuropathologically involved areas. In stroke, the SOD value does not vary either in the ischemic area or in the peri-infarctual one during the first 24 hrs after lesion, while the CAT value decreases.     

Lipid peroxidation and concentration of glutathione in erythrocytes from workers exposed to lead

Lipoperoxide concentration in erythrocytes from workers occupationally exposed to lead (mean blood lead concentration 57.1 (SD 17.6) micrograms/dl) was significantly higher than that in controls. It was not different in plasma from the two groups. The activity of superoxide dismutase (SOD) and catalase in erythrocytes from workers exposed to lead was significantly lower than that of control subjects. The effect of lead was also seen in the glutathione concentration of erythrocytes from lead exposed workers, which was reduced to 69% of that found in erythrocytes from control workers. The increase in methaemoglobin content of erythrocytes from workers exposed to lead was less than expected and not significantly different from that of controls. A positive correlation between lipoperoxide concentration in erythrocytes and lead concentration in blood and a negative correlation between glutathione concentration in erythrocytes and blood lead concentration were found. Incubation of erythrocytes for 24 hours at 37 degrees C in the presence of lead (100 micrograms/dl) produced no changes in glutathione and lipoperoxide concentrations, although there was inhibition of activity of SOD (14.3%), catalase (10.1%), and glutathione peroxidase (35.1%). A similar experiment with heparinised whole blood showed increased haemolysis with no changes in membrane lipid peroxidation of erythrocytes. It is postulated that the lowered concentration of glutathione and decreased activity of SOD, catalase, and glutathione peroxidase in erythrocytes from workers exposed to lead may play a part in the increased membrane lipid peroxidation. Furthermore, the results suggest the possibility that leucocytes, or platelets, or both, may induce haemolysis in the presence of lead.     

Lipid peroxidation and concentration of glutathione in erythrocytes from workers exposed to lead.

Lipoperoxide concentration in erythrocytes from workers occupationally exposed to lead (mean blood lead concentration 57.1 (SD 17.6) micrograms/dl) was significantly higher than that in controls. It was not different in plasma from the two groups. The activity of superoxide dismutase (SOD) and catalase in erythrocytes from workers exposed to lead was significantly lower than that of control subjects. The effect of lead was also seen in the glutathione concentration of erythrocytes from lead exposed workers, which was reduced to 69% of that found in erythrocytes from control workers. The increase in methaemoglobin content of erythrocytes from workers exposed to lead was less than expected and not significantly different from that of controls. A positive correlation between lipoperoxide concentration in erythrocytes and lead concentration in blood and a negative correlation between glutathione concentration in erythrocytes and blood lead concentration were found. Incubation of erythrocytes for 24 hours at 37 degrees C in the presence of lead (100 micrograms/dl) produced no changes in glutathione and lipoperoxide concentrations, although there was inhibition of activity of SOD (14.3%), catalase (10.1%), and glutathione peroxidase (35.1%). A similar experiment with heparinised whole blood showed increased haemolysis with no changes in membrane lipid peroxidation of erythrocytes. It is postulated that the lowered concentration of glutathione and decreased activity of SOD, catalase, and glutathione peroxidase in erythrocytes from workers exposed to lead may play a part in the increased membrane lipid peroxidation. Furthermore, the results suggest the possibility that leucocytes, or platelets, or both, may induce haemolysis in the presence of lead.     

苯对作业工人血清中SOD活力及LPO含量影响的研究

９２名油漆工为观察组，５７名行政人员、教师和学生为对照组，观察其白细胞计数（ＷＢＣ）、血清过氧化脂质（ＬＰＯ）含量及超氧化物歧化酶（ＳＯＤ）的活力。结果；观察组ＷＢＣ异常［低于４０００／ｍｍ３（４×１０９／Ｌ）］检出率高于对照组（Ｐ＜０．０１）；ＳＯＤ活力高于对照组（Ｐ＜０．０５），且与ＷＢＣ呈负相关。观察组中ＷＢＣ低于４０００／ｍｍ３（４×１０９／Ｌ）的人群，其血清ＳＯＤ活力高于ＷＢＣ４０００／ｍｍ３以上的人群。在ＷＢＣ高于４０００／ｍｍ３（４×１０９／Ｌ）的人群中，血清ＳＯＤ活力观察组也高于对照组。说明苯对作业工人血清中ＳＯＤ水平有影响，且比较敏感，其意义有待进一步研究。ＬＰＯ两组无差别。Ｐ＜０．０１２．３ＬＰＯ及ＳＯＤ测定结果观察组ＬＰＯ值低于对照组，但统计学处理差异无显著意义。ＳＯＤ活性观察组高于对照组，差异具有显著意义（Ｐ＜０．０５）。观察组按工龄及吸烟与否分组，各组间ＳＯＤ活性无显著性差异（表３）。表３观察组与对照组血清ＬＰＯ、ＳＯＤ测定结果比较＊ｐ＜０．０５２．４ＷＢＣ、ＬＰＯ、ＳＯＤ之间相关性分析ＳＯＤ与ＬＰＯ之间、ＷＢＣ与ＬＰＯ之间相关关系不明显（ｐ＞０．０５），而ＷＢＣ与ＳＯＤ之间呈负相     

Blood superoxide dismutase and plasma malondialdehyde among workers exposed to asbestos

Blood superoxide dismutase (SOD) and plasma malondialdehyde (MDA) (an indicator of lipid peroxidation [LPO]) were determined in 97 randomly selected asbestos exposed workers (age range: 25–60 years, mean duration of exposures 19.8 ± 8.3 years) and in 42 healthy male controls. MDA, SOD, and MDA/SOD ratio in asbestos exposed workers were significantly higher than in controls. Among both the controls and exposed workers neither age nor smoking was related to SOD or MDA levels. SOD was significantly positively correlated with MDA among the exposed workers. Such correlation was not observed among the controls. SOD but not MDA was significantly positively correlated with the duration of exposure to asbestos. Mean levels of SOD or MDA in exposed workers with radiographic signs of lung fibrosis or pleural thickening did not differ significantly from those without such signs. The results confirm the possible involvement of LPO and development of anti-oxidant mechanism(s) of prolonged exposure to asbestos in humans. However, SOD seems not to be the essential anti-asbestos-induced LPO. Relation between these factors and lung fibrosis is still unclear.     

Effect of lead on cardiac parasympathetic function

Summary A cross-sectional survey was performed on 172 male, lead exposed workers to clarify the effects of lead on the cardiac autonomic nervous system expressed as the decrease of R-R interval variation on an electrocardiogram and to obviate the dose-effect relationship between blood-lead level (Pb-B) and the degree of the decrease. For 132 workers who were exposed to lead for more than one year and whose Pb-B levels were relatively stable (Pb-B variation less than 20 g/dl during recent one year), a significant dose-related decrease of R-R interval variation during deep breathing was observed. Age-adjusted R-R interval variation during deep breathing in those whose Pb-B were 30 g/dl or above was significantly decreased compared with those whose Pb-B levels were 20 g/dl or below. This decrease was observed more clearly in younger workers. These results suggest that an effect on autonomic nervous system expressed as decrease of R-R interval variation during deep breathing might be one of the earliest effects of lead exposure.     

丙烯腈对男工脂质过氧化作用研究

目的 探讨不同浓度丙烯脂(ACN)对男工机体产生脂质过氧化作用的规律,筛选早期敏感的损害效应生物标志物。方法 以四名接触ACN男工为接触组,条件相近的不接触毒物的70名男工为对照组,测定血清中MDA、ROS、GSH含量和SOD、GSH-Px、GST、CAT活力。结果 与对照组比较,接触组血清MDA、ROS含量显著升高(P＜0.01),SOD、GSH-Px、GST、GSH显著下降(P＜0.05),上述各指标随工龄增加和车间中ACN浓度升高而升高或下降,均存在良好的剂量—效应关系,且以MDA、ROS和SOD改变出现较早。结论 在本次调查的浓度范围内ACN可引起机体脂质过氧化损伤,提示ACN浓度在低于或接近国家标准时仍可引起损害效应,建议将血清中MDA、ROS和SOD作为较早期损害效应的生物标志物。     

固井水泥粉尘对接触工人抗氧化酶的影响

目的探讨固井水泥粉尘对作业工人和机体脂质过氧化(LPO)的影响.方法对98名固井水泥粉尘接触工人和30名不接尘健康对照进行血清丙二醛(MDA)含量、超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性测定.结果与对照组比较,固井水泥粉尘接触工人血清MDA含量升高,SOD和GSH-Px活性下降,差异均有显著性(P＜0.01);相关分析显示:随着作业工人接尘工龄的延长,血清MDA含量有增高的趋势(r=0.357 0, P＜0.01),血清SOD和全血GSH-Px活性呈下降趋势(r=-0.739 8;-0.301 3, P＜0.01).结论固井水泥粉尘作业工人体内氧自由基反应加剧,氧化/抗氧化状态严重失衡.     

锌对氯化汞免疫毒性的影响及其机理

为了探讨锌对氯化汞免疫毒性的影响,采用免疫毒理学和生化毒理学方法观察氯化汞染毒的ＩＣＲ小鼠血中碳廊清率、绵阳红细胞（ＳＲＢＣ）致敏小鼠迟发型过敏反应（ＤＴＨ）、二硝基氯苯（ＤＮＣＢ）所致的迟发型皮肤过敏反应（ＤＣＨ）、血清溶血素（ＨＣ５０）和免疫脏器系数,结果显示：上述指标均明显低于对照组;预先给予醋酸锌后再给同剂量氯化汞的小鼠上述各指标均有不同程度提高;免疫器官脂质过氧化作用,汞组脂质过氧化物（     

外源性超氧化物歧化酶对氯化汞免疫毒性的影响

采用免疫毒理学方法观察外源性ＳＯＤ对汞的免疫毒性的影响。结果氯化汞染毒的ＩＣＲ小鼠血中碳廓清率、ＳＲＢＣ致敏小鼠迟发型过敏反应（ＤＴＨ），ＤＮＣＢ所致的迟发型皮肤过敏反应（ＤＣＨ），血清溶血素（Ｈｃ５０）和免疫脏器系数均明显低于对照组，预先给予ＳＯＤ后再给同剂量氯化汞的小鼠除Ｈｃ５０外上述各指标均有不同程度提高。免疫器官脂质过氧化作用，汞组脂质过氧化物（ＬＰＯ）含量明显高于对照组，ＳＯＤ活性比对照组明显降低（Ｐ＜０．０１），而ＳＯＤ－汞组与汞组比较，ＬＰＯ含量明显降低，ＳＯＤ活性明显升高（Ｐ＜０．０５）。提示外源性ＳＯＤ能拮抗氯化汞所致的免疫毒性和脂质过氧化作用。     

Plant self-defense mechanisms against oxidative injury and protection of the forest by planting trees of triploids and tetraploids

The depletion of the ozone layer, and the resulting substantial increase in incident ultraviolet (UV) irradiation and subsequent oxygen radical formation on the Earth, have caused an extensive variety of damage to the world's forests. Superoxide dismutase (SOD), catalase, and glutathione peroxidase (GSH-Px), which scavenge harmful oxygen radicals and inhibit lipid peroxides, were examined in two types of Japanese cedars, black pines, and cypresses, namely those with leaves showing premature withering, shedding, or dying and those with leaves not showing these effects prematurely. The effect of homogenates from these trees on lipid peroxide formation in a reaction system which UV light induces was also studied. The results indicate that strong black pines have significantly higher SOD activities than ordinary black pines, the leaves of which prematurely wither or die. Remarkably, trees that had triploid or tetraploid chromosomes showed higher SOD levels than diploid trees and markedly inhibited lipid peroxide formation since the SOD gene resides on a chromosome. This was especially true of plus trees of Japanese cypress, some of which had five times higher SOD activities than common Japanese cypresses although GSH-Px appears to play less of a role in this regard. Rice leaves and osmunda which are resistant to UV damage showed markedly higher SOD and GSH-Px activity. Our experiments suggest that the trees that have high SOD can protect themselves by scavenging oxygen radicals induced by UV irradiation and inhibit harmful lipid peroxide formation. In order to protect forests from oxidative damage by UV light, we should plant trees of natural mutants and artificially crossed triploids and tetraploids.     

灭白蚁药物对人体脂质过氧化水平的影响

为探讨职业性接触氯丹、含砷化合物灭蚁药物对作业人员脂质过氧化水平的影响,对作业人员进行了血清中过氧化脂质代谢物(MDA)和红细胞超氧化物歧化酶(SOD)、谷胱甘肽氧化酶GSH-Px、血清氯丹和尿砷水平的检测分析,并对工龄、吸烟、饮酒和体内毒物的浓度对脂质过氧化各项指标水平的影响进行统计学分析。结果显示,职业接触灭蚁药物使作业人员血清中MDA增高、SOD、GSH-Px水平显著下降,并与工龄相关;吸烟、饮酒能加重灭蚁药物对人体脂质过氧化水平的影响,MDA与血清氯丹和尿砷含量呈正相关,SOD、GSH-Px的水平与血清氯丹和尿砷含量呈负相关。提示职业性接触灭蚁药物能使体内脂质过氧化反应明显增强。     

Genotoxic effects in workers exposed to low levels of benzene from gasoline

To study genotoxic effects of exposure to low levels of benzene, single-strand breaks (SSB) in DNA of leukocytes and urinary levels of the oxidative DNA adduct 8-hydroxydeoxyguanosine (80HdG) were determined in 33 men occupationally exposed to benzene from gasoline and in 33 controls. The average exposure to benzene over a shift was determined by personal air sampling in the breathing zone. The 8-hr time-weighted average exposure to benzene was 0.13 ppm (mean value, range 0.003–0.6 ppm). Exposed workers had a significant increase of SSB (p = 0.04) over the shift compared with controls. Storage time of the samples seemed to affect the results. An analysis of samples with the same storage time showed a nonsignificant increase among the workers compared with controls. Urinary 80HdG increased over the shift among the exposed workers but not among the controls. The highest values among the exposed workers were seen in late evening, with a slight decrease the next morning. Multiple linear analysis adjusting for smoking habits showed a significant association between the exposure level of benzene during the shift and the increase of 80HdG in the urine over the shift among exposed workers (p = 0.02). These findings indicate a genotoxic effect in humans of benzene at relatively low exposure levels, that is, about 0.1 ppm (0.3 mg/m³). © 1996 Wiley-Liss, Inc.     

炼油污水挥发物对作业工人脂质过氧化反应的影响

目的 探讨低浓度炼油污水作业对人体氧化和过氧化反应的影响。方法 检测73例污水处理作业工人和129例健康对照血清丙二醛（MDA）含量和血清超氧化物歧化酶（SOD）、全血谷胱甘肽过氧化物醇（GSH－Px)和过氧化氢酶（CAT）活力。结果 污水处理作业工人血清SOD和全血GSH－Px活力与对照组相比,差异具有显著性（P＜0．01）,CAT的差异不具有显著性。中工龄组（5－20年）GSH－Px活力明显高于对照组,而高工龄组（＞20年）差异不具有显著性。接触组SOD活力仅低工龄组（＜5年）较对照组高（P＜0．05）。结论 低浓度长期接触炼油污水挥发物,体内的脂质过氧化反应和抗氧化机制均处于亢奋状态,后者可能是机体的一种防御机制。     

煤矿粉尘接触和人群脂质过氧化水平的观察

目的 为了解煤矿粉尘接触和人群脂质过氧化水平。方法 检测煤矿粉尘接触量和人群脂质过氧化水平。结果 矿井巷道和采煤面粉尘浓度低于国家标准装渣,放炮作业和各工种一次最高浓度均超国标。除矿井出风口外,地面各监测点可吸入粉尘均在容许范围,粉尘接触人群ＳＯＤ活性降低,井下工人ＭＤＡ增加,吸烟者更显著,煤工尘肺患者两项指标同时提高,结论 提示煤尘接触引起人群脂质过氧化代谢紊乱,紊乱程度和粉尘接触量有关,吸烟是     

放射人员血超氧化物岐化酶等的活性测定

In this study, we measured the superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase GPX) activities in the peripheral blood of radiation workers (111 cases) and the controls (108 cases), also analyzed chromosome aberrations in blood lymphocytes by means of G-banding technique. The chromosome deletions were not found in the controls. There were 7 cases chromosome deletions found by G-banding in 111 cases of radiation workers, their SOD activities were markedly lower than those in the controls (P less than 0.05). SOD and CAT activities in the other 104 cases of radiation workers were significantly higher than those in the controls (P less than 0.01). But there was no difference of GPX activity between the radiation workers and the controls. However, increase of SOD activity mainly occurred in radiation workers who were exposed to radiation over 0.0177 +/- 0.0032 Gy. The possible mechanism of this phenomenon was discussed.     

有机氟作业工人免疫功能及脂质过氧化水平的观察

目的 探讨有机氟加工业对工人的免疫系统及血脂质过氧化水平的影响。方法 对４８名有机氟作业工人及２６名不接触任何毒物的健康者,进行血Ｔ－淋巴细胞酯酶（Ｔ－ＡＮＡＥ）计数、免疫球蛋白（ＩｇＧ、ＩｇＡ、ＩｇＭ）含量、超氧化物歧化酶同工酶活力（ＳＯＤ、Ｍｎ－ＳＯＤ、ＧｕＺｎ－ＳＯＤ）及丙二醛（ＭＤＡ）含量测定。结果 接触组的Ｔ－ＡＮＡＥ计数降低,ＳＯＤ、Ｍｎ－ＳＯＤ活力下降,ＭＤＡ含量升高有显著意义,Ｉｇ     

Erythrocyte antioxidant enzyme activities and lipid peroxidation in the erythrocyte membrane of stainless-steel welders exposed to welding fumes and gases

The erythrocyte antioxidant system (superoxide dismutase, SOD; catalase, CAT) and lipid peroxidation (malondialdehyde, MDA) in the erythrocyte membrane were studied in workers continously exposed to welding fumes and gases, which are thought to be oxidant pollutants. Thirty-five welders using the manual metal arc method on stainless steel and 30 controls were studied. Plasma chromium (Cr), manganese (Mn), and cupper (Cu) levels were determined by atomic absorption spectrophotometer (AAS). The erythrocyte antioxidant system activity and lipid peroxidation in the erythrocyte membrane were evaluated. Not only the possible effects of welding fumes but also the effects of smoking were considered. The plasma concentrations of Cr, Mn, and Cu for the exposed welders were significantly higher compared to the control subjects (p<0.001, p<0.01, p<0.001, respectively,). The erythrocyte CAT (p<0.05) and SOD (p<0.05) enzyme activities were significantly higher in the welders but there were not any significant changes in the MDA levels which reflect the lipid peroxidation in the erythrocyte membrane (p>0.05). Smoking has increased the SOD activity in both controls (p<0.05) and welders (p<0.01) and increased the CAT activity in control subjects (p<0.05). Moreover, regardless of smoking, there were some significant correlations between the duration of the exposure to welding fumes and antioxidant defence system (SOD: p<0.05; CAT: p<0.05). The synergistic effects of smoking and other risk factors (welding fumes and gasses), which had been shown previously by some clinical data should also be taken into account. As a consequence, the welders should be warned and informed of the synergistic effects of smoking on the adverse effect of welding fumes and gases.     

Mercury uptake and enzymatic response of Posidonia oceanica after an experimental exposure to organic and inorganic forms

The aim of this study was to examine the experimental uptake of mercury and the enzymatic response, i.e., glutathione S-transferase (GST) activity, to this metal introduced into the medium under organic (methylmercury chloride) and nonorganic (mercury chloride) forms. Shoots of Posidonia oceanica were collected in a nonpolluted area in the northwestern Mediterranean Sea and were treated in aquaria with increasing mercury concentrations/exposure times (48, 96, and 144 h). Compared with the controls, a significant uptake was noted in the blades contaminated by HgCl2, whereas in the sheaths, a significant decrease of total mercury was noted. The blades exposed to CH3HgCl exhibited higher mercury concentrations than the controls; after 144 h exposure to organic mercury, the levels found in the blades were approximately sevenfold the values of the controls. The uptake noted in the sheaths treated with organic mercury followed the same pattern as with HgCl2 (decreased value compared with the controls) except after 144 h, where a slight increase in mercury was found in this tissue. The percentage of organic mercury in controls and treated blades and sheaths (treatment with both forms of mercury) represented always more than 50% of the total mercury in the plant. Glutathione S-transferase activities were significantly increased in the blades and sheaths of P. oceanica exposed to mercury chloride, whereas exposure to methylmercury was not significant. The presence of a GST isoform of 31 kDa was demonstrated by immunochemical methods (Western blotting) in the sheaths but not in the blades of the phanerogam.