甲醛降解微生物

<正>甲醛是一种无色、有强烈刺激性气味的化合物,易溶于水、醇和醚,在常温下是气态,通常以水溶液形式出现。环境中甲醛的主要污染来自于合成纤维、染料、木材加工及制漆等化工行业排放的废水、废气等。其主要危害表现为对皮肤粘膜的刺激作用,高浓度甲醛则对神经系统、免疫系统、肝脏等都有毒害[1],国际癌症研究机构(IARC)已将甲醛上升为第I类致癌物质,因此对甲醛污染进行防治工作对人类健康具有重大意义。由于甲醛的分子结构在环境中极为稳定,一般氧化剂无法破坏其结构,也就无法消除其污染。目前去除甲醛污染的     

检测DNA-蛋白质交联的新方法

将彗星实验进行改进以用于DNA-蛋白质交联作用的检测。利用甲醛对受试动物肝细胞的影响来判定此法是否适用于检测DNA-蛋白质交联。由于在实验中添加一定量的蛋白酶K, 可使单细胞在电泳时产生更大的迁移, 因此可以利用添加蛋白酶K前后的彗星尾距比来判断外来化合物对生物机体产生DNA损伤效应的时候是否有出现DNA-蛋白质交联作用。结果表明, 该方法快速、经济、灵敏度较高, 可以在单细胞水平对甲醛等强交联剂引发的不同组织的DNA-蛋白质交联效应进行检测, 希望该方法能成为指示DNA交联能力的有用工具。     

甲基营养微生物的甲醛代谢途径及其在环境生物技术中的应用

甲醛是一种毒性很高的一碳化合物,甲基营养菌是一类能在有高浓度甲醛的环境中生存的微生物,它们体内有多种降解甲醛的氧化途径和将甲醛转化为细胞组分的同化途径。丝氨酸途径和酮糖单磷酸途径是同时存在于甲基营养型细菌中的两种甲醛同化途径,木酮糖单磷酸途径是甲基营养型酵母菌中独有的甲醛同化途径。为了充分挖掘甲基营养型微生物在环境生物技术中的潜在应用价值,最近有很多研究尝试利用甲基营养微生物的细胞及其甲醛代谢途径关键酶开发甲醛污染检测方法和生物治理技术,对这方面的研究进展进行综述。     

Paraoxonase-1介导硫化氢的抗甲醛神经毒性作用

我们以往的研究工作证实了硫化氢(hydrogen sulfide,H2S)对甲醛神经毒性和氧化应激具有拮抗作用.Paraoxonase-1(PON-1)是机体重要的内源性抗氧化剂.本研究的目的是探讨PON-1是否可介导H2S的抗甲醛神经毒性作用.采用甲醛损伤PC12细胞为甲醛神经毒性的细胞模型.硫氢化钠(NaHS,一种H2S的供体)不仅可以上调PC12细胞PON-1的活力,还可恢复甲醛对PC12细胞PON-1表达与活力的抑制作用.2-hydroxyquinoline(2-HQ)是一种选择性PON-1抑制剂,它可显著降低H2S对甲醛细胞毒性、凋亡和活性氧(reactive oxygen species,ROS)累积的抑制作用.而且,2-HQ可阻止H2S逆转甲醛激活PC12细胞caspase-3和下调PC12细胞bcl-2表达.结果提示H2S依赖PON-1去保护PC12细胞对抗甲醛的神经毒性.我们的这一发现表明PON-1有希望成为防治甲醛神经损伤的新靶点.     

体液联系在调节机体活动中的作用

有机体不能脱离开它的周围环境而独立生存,同时,机体的生活环境又是千变万化的,因此,只有机体本身能够时时刻刻对这种不断发生变化的环境进行及时的适应性的反应时才可以维持生存。保证机体能够和周围环境维持适应的那些生理过程就是我们所说的调节作用。这种调节作用也只有当机体内的一切组织或是器官之间建立了联系时才可以实现。     

老年性痴呆发病过程中内源性甲醛慢性损伤机制

通过原子力显微镜、荧光标记、Congo染色等方法,观察到低浓度甲醛可以诱导人类神经Tau蛋白错误折叠并形成具有细胞毒性的似球状聚积物;气相色谱和液相色谱等分析结果表明,神经鞘磷脂N-Acyl-4-sphingoine-1-phosphocholine (myelin的过氧化能够产生甲醛分子;脂质过氧化的代谢产物丙二醛(malondialdehyde)在修饰蛋白质(BSA)的过程中,亦可产生甲醛分子.以上结果为内源性甲醛的产生揭示了新的途径.值得注意的是,在生理条件下,血液中内源性甲醛的水平维持在一个动态平衡((0.087±0.004)retool/L),与体外培养神经细胞时甲醛产生毒性的浓度(～0.1 mmol/L)十分接近,甚至已经达到产生一定细胞毒性的水平.随着机体的衰老,内源性甲醛的调节机能下降,在氧化应激等相关因素的诱导作用下,内源性甲醛浓度可能升高,对中枢神经系统一定部位的神经细胞造成慢性损伤,这可能是散发性老年痴呆发病的机制之一.     

利用酶清除室内甲醛气体的新方法

甲醛脱氢酶是一种可以将甲醛进行转换的氧化还原酶,利用改质甲醛脱氢酶对于甲醛的专一反应性可达到去除甲醛气体的效果.根据密闭空间测试甲醛去除效率,在10min 内可去除空间中85% 的甲醛气体.经过现场测试后发现,将甲醛去除器置放在含有福尔马林的储藏室中可在一周内降低70% 的甲醛浓度,两周后可将甲醛浓度降至安全标准以下.结果显示甲醛去除器不仅能够去除实验室中密闭空间内的甲醛气体,在一般布满甲醛气体的空间中依然可以在短时间内去除空间中的甲醛气体,避免人体受到甲醛的危害.     

某私营木制家具制造企业2004 年与2010 年职业病危害因素检测 与评价报告比较和分析

目的:通过比较2个年份职业病危害因素检测与评价报告,评估职业病防治工作的效果。方法:选取两份有代表性的报告,比较和分析职业病危害防护设施的安装、个人防护用品发放与使用、警示标示以及各项检测结果的合格率。结果:该企业2010年各项调查指标相比2004年明显提高。结论:该企业各项职业病防治工作效果显著,劳动环境明显改善,但仍需注意噪声、木粉尘的危害。     

室内观赏植物对甲醛的吸收及抗逆效果研究

该研究采用密封舱法模拟室内甲醛污染环境(熏蒸箱内甲醛浓度设置为0.1~0.5 mg·m~(-3),熏气时间12 h),对6种常见室内观赏植物进行甲醛熏蒸实验,测定了植物对甲醛的吸收效率、叶面伤害指数及过氧化物酶(POD)等指标。结果表明:这6种常见观赏植物对甲醛均具较好的净化效果,甲醛熏蒸浓度为0.1~0.3 mg·m~(-3),白鹤芋对甲醛的净化效果最好;熏蒸浓度0.5 mg·m~(-3),绿萝和吊兰具有较好的净化和抗逆性能;铁线蕨对甲醛的耐受力较弱,适合作为室内甲醛污染的指示性植物。几种受试植物的POD酶与甲醛吸收率呈显著正相关关系(P0.05),表明植物POD活力变化是受甲醛胁迫后的主要抗逆应答机制之一。     

研究: 甲醛对果蝇寿命及其在应激条件下耐受性的影响

虽然甲醛对人及动物多种器官的毒性作用已经有了大量研究,但不同浓度甲醛影响动物寿命的研究还极其少见.本文用黑腹果蝇作为模式生物,在食物中添加不同浓度的甲醛,观察果蝇寿命及其在应激条件下耐受性的变化.实验结果显示,雌性果蝇的寿命表现出对甲醛浓度的依赖,0.037%甲醛可以极显著地延长雌性果蝇的寿命,较高浓度甲醛(≥0.185%)可以极显著地缩短雌性果蝇与雄性果蝇的寿命.0.037%甲醛还可以极显著地增强雌性和雄性果蝇对饥饿以及高温的耐受性,但减弱其对活性氧的耐受性.这些结果有助于从新的途径研究果蝇寿命及其在应激条件下耐受性的分子机制.     

Biomarkers in risk assessment of asbestos exposure

Developments in the field of molecular epidemiology and toxicology have given valuable tools for early detection of impending disease or toxic condition. Morbidity due to respiratory distress, which may be due to environmental and occupational exposure, has drawn attention of researchers worldwide. Among the occupational exposure to respiratory distress factors, fibers and particles have been found to be main culprits in causing diseases like asbestosis, pleural plaques, mesotheliomas and bronchogenic carcinomas. An early detection of the magnitude of exposure or its’ effect using molecular end points is of growing importance. The early inflammatory responses like release of the inflammatory cells collected by non-invasive methods give an indication of the unwanted exposure and susceptibility to further complications. Since free radicals like O₂⁻, OH, OOH, NO, NOO, etc. are involved in the progression of asbestos-related diseases and lead to cytogenetic changes, an evaluation of antioxidant states reducing equivalents like GSH and ROS generation can be a good biomarker. The cytogenetic end points like chromosomal aberration, micronucleus formation and sister chromatid exchange give indication of genetic damage, hence they are used as effective biomarkers. New techniques like fluorimetric analysis of DNA unwinding, alkaline elution test, fluorescent in situ hybridization and comet assay are powerful tools for early detection of initiation of disease process and may help in planning strategies for minimizing morbidity related to asbestos fiber exposure. The present review article covers in detail possible biomarkers for risk assessment of morbidity due to fibers/particles in exposed population.     

Prevention of occupational asthma in Ontario

Occupational asthma continues to be one of the most common occupational lung diseases in industrialized areas. Primary and secondary preventive measures have been well described, but there are relatively few studies to support the effectiveness of such measures, although the benefits of tertiary measures such as early recognition and removal from further exposure to a causative sensitizing agent are well recognized. In Ontario, a combined approach of preventive measures has shown effectiveness in allergy and asthma from occupational exposure to natural rubber latex. In addition, a program to reduce exposure to diisocyanates and introduce medical surveillance was associated with earlier diagnosis and fewer cases in a compensation population. However there remain barriers to the early diagnosis of occupational asthma in Ontario, especially in workers of lower education and lower income. In addition, there is recognized need for further physician education to allow early suspicion and diagnosis of occupational asthma.     

Emerging technologies for salivaomics in cancer detection

Salivary diagnostics has great potential to be used in the early detection and prevention of many cancerous diseases. If implemented with rigour and efficiency, it can result in improving patient survival times and achieving earlier diagnosis of disease. Recently, extraordinary efforts have been taken to develop non‐invasive technologies that can be applied without complicated and expensive procedures. Saliva is a biofluid that has demonstrated excellent properties and can be used as a diagnostic fluid, since many of the biomarkers suggested for cancers can also be found in whole saliva, apart from blood or other body fluids. The currently accepted gold standard methods for biomarker development include chromatography, mass spectometry, gel electrophoresis, microarrays and polymerase chain reaction‐based quantification. However, salivary diagnostics is a flourishing field with the rapid development of novel technologies associated with point‐of‐care diagnostics, RNA sequencing, electrochemical detection and liquid biopsy. Those technologies will help introduce population‐based screening programs, thus enabling early detection, prognosis assessment and disease monitoring. The purpose of this review is to give a comprehensive update on the emerging diagnostic technologies and tools for the early detection of cancerous diseases based on saliva.     

Role of genetic and environmental influences on heart rate variability in middle-aged men

Our aim was to estimate causal relationships of genetic factors and different specific environmental factors in determination of the level of cardiac autonomic modulation, i.e., heart rate variability (HRV), in healthy male twins and male twins with chronic diseases. The subjects were 208 monozygotic (MZ, 104 healthy) and 296 dizygotic (DZ, 173 healthy) male twins. A structured interview was used to obtain data on lifetime exposures of occupational loading, regularly performed leisure-time sport activities, coffee consumption, smoking history, and chronic diseases from 12 yr of age through the present. A 5-min ECG at supine rest was recorded for the HRV analyses. In univariate statistical analyses based on genetic models with additive genetic, dominance genetic, and unique environmental effects, genetic effects accounted for 31-57% of HRV variance. In multivariate statistical analysis, body mass index, percent body fat, coffee consumption, smoking, medication, and chronic diseases were associated with different HRV variables, accounting for 1-11% of their variance. Occupational physical loading and leisure-time sport activities did not account for variation in any HRV variable. However, in the subgroup analysis of healthy and diseased twins, occupational loading explained 4% of the variability in heart periods. Otherwise, the interaction between health status and genetic effects was significant for only two HRV variables. In conclusion, genetic factors accounted for a major portion of the interindividual differences in HRV, with no remarkable effect of health status. No single behavioral determinant appeared to have a major influence on HRV. The effects of medication and diseases may mask the minimal effect of occupational loading on HRV.     

Some observations on the needs of ergonomics in industries in Hong Kong.

The author's interest in ergonomics lies in the common ground it shares with occupational health, since ergonomics aims to make work easier, safer, and more productive and to promote efficiency, comfort, and health. In Hong Kong, owing to lack of natural resources and guaranteed markets, industrialization has not taken a smooth course. Only light industries exist, and one industry flourishes after another. Occupational health and safety tends to be neglected not only by the employers but by the employees. The government becomes the promoter of labor legislation. There is almost no information on occupational diseases. There are some elementary official statistics on occupational accidents. There is practically no research activities on this area going on. There is a very critical lack of occupational health, workers in Hong Kong. Ergonomics may help in improving the present situation because its aims are more positive to the industrialists and the workers who should be converted into educated consumers of ergonomics. In the long run, advancement in occupational health and safety practice will be made.     

Use of principles of prenosological diagnosis for assessing the functional state of the body under stress conditions as exemplified by bus drivers

The functional state of the body was assessed in healthy subjects performing their daily work under stress conditions. The study sample comprised bus drivers aged 25–65 years. A prenosological approach was used to assess the borderline between the physiologically normal state and pathological conditions. At the first stage of the study (prenosological screening), the subjects were divided into four groups with different adaptive capacities of the body. At the second stage of the study, a detailed prenosological examination was performed to determine the causes and mechanisms of evolution of prenosological conditions into premorbid conditions and further into adaptation failure, resulting in diseases. It was found that the bus drivers experienced chronic occupational stress leading to the overtension and exhaustion of regulatory mechanisms and to the rapid development of cardiovascular pathology. Long-term mental and psychoemotional tension in drivers associated with occupational stress leads to the activation of suprasegmental structures involved in the control of physiological functions; to a decrease in the functional reserves; and, consequently, to the worsening of the psychophysiological and cardiorespiratory function of the body. As a result of the study, a group of bus drivers with an increased risk of diseases, including cardiovascular, was determined and recommendations on workforce health protection were developed for the managers of the motor transport enterprise.     

The remote effects of chronic exposure to ionizing radiation and electromagnetic fields with respect to hygienic standardization

A variety and rate of non-cancer diseases occurred in humans as a result of chronic exposure to ionizing radiation or to electromagnetic radiation (EMR) of high and superhigh frequency have been compared. The intensity of EMR was slightly higher than a sanitary standard for population. A risk of health impairments in workers having occupational exposure to EMR was assessed on the basis of Selie's concept of development of non-specific reaction of the body to chronic stress factors (general adaptation syndrome), models of changes in the body compensatory reserves and calculations of radiation risk after severe and chronic exposure to ionizing radiation.     

脑疾病与游离氨基酸的研究

脑疾病包括肝性脑病 (或肝昏迷 ) ,乙型脑炎 ,儿童智力发育不全 ,脑瘫 ,新生儿缺氧缺血脑病以及脑衰老等。研究结果说明 :( 1 )肝性脑病 (或肝昏迷 )和乙型脑炎患者体液中谷氨酰胺水平升高 ,这种升高可以作为以上两种疾病的早期诊断 ;( 2 )脑瘫 ,智力发育不全以及脑衰老 (动物 )等患者 ,体液中谷氨酸浓度降低而r 氨基酸 (GABA)浓度升高 ,它们可以作为评价大脑损伤程度的指标 ,同时也有早期诊断这些疾病的价值 ;( 3)适当补充必需氨基酸能控制以上各种脑疾病的发展。     

The potential role of exosomes in the diagnosis and therapy of ischemic diseases

In the past, exosomes have been thought of as cellular dust. Today, they are thought to be carriers of real biomarkers and intercellular biological information. The composition of exosomes differs according to their source, and the subsequent information they carry, such as protein, microRNA or mRNA, may also be different. Recent studies have demonstrated that exosomes in ischemic diseases can help to make an early diagnosis, and in cellular experiments and animal models, exosomes promote angiogenesis, restrain cell apoptosis and reduce inflammation, among other actions, to protect ischemic organs. There is evidence that these protective effects are related to microRNAs in exosomes. In this review, we discuss the use of exosomes for early diagnosis of ischemic diseases and recent advances in the therapeutic use of exosomes in cell and mammalian models of ischemic diseases.     

Theory and practice of primary cancer prevention

The primary aim of cancer prevention is to stop carcinogens from entering the body. Since the low doses involved in carcinogenesis do not cause true toxicological effects, usual toxicological analytic methods do not allow the detection of the early effects of carcinogens. Exposure to chemical carcinogens causes damage to nuclear chromatin, the most vulnerable part of the cell, by inducing DNA damage, chromosomal abnormalities and mutations, which foreshadow the danger of cancer development. In such cases intervention is possible in two ways. On the one hand, we attempt to remove the causative agent from the environment, while on the other we aid the elimination of somatic mutations. The latter is called active prevention; the introduction of substances into the body that can help the elimination of defective cells (apoptosis induction) or stop processes responsible for elongation errors (i.e. with antioxidants). Concerning our own studies, we present the results of 25 years of research on the genotoxicological characteristics of workers exposed to various chemicals, which show that active prevention can in fact be effective in conjunction with information on specific biomarkers. We present in detail the genotoxic changes found in hospital nurses who routinely administer intravenous cytostatic therapy, and the relationship of these changes to their immunotoxic and clinical laboratory parameters. Genotoxic substances decrease the oxidative burst and natural killer (NK) cell activity, which may explain the immunosuppressive effects of occupational exposures. We also present the detailed results of a follow-up study involving two groups of industrial workers. We monitored the status of workers involved in benzene production for 15 years and of asphalt industry workers for 8 years. In both studies we concluded that genotoxic effects can be decreased by ensuring appropriate working conditions, while a temporary lapse in these conditions or accidental changes lead to increases in genotoxic parameters. Since genotoxic effects develop over an extended period (4-5 months), they are independent of hygienic conditions at any single inspection and, thus, their detection also offers a way to ascertain true exposure levels. Our studies also show a connection between genotoxic effects and immune function, which is adversely affected not only by occupational exposures, but also by medications and smoking. From our results with workers in the oil and asphalt industries, we concluded that the levels of chromosomal aberrations (CAs) and sister chromatid exchange (SCE) increase in proportion to exposure levels and decrease with a certain delay following the attenuation of the exposure. We could not detect an increased frequency of any chronic disease in industrial workers. The increased numbers of iron deficiency anemia and thyroid disease in nurses providing cytostatic therapy was, however, related to their occupational exposure.