1
|
Wang Z, Gou X, Shi Q, Liu K, Chang X, Wang G, Xu W, Lin S, Liu T, Fang Y. Through‐Space Charge Transfer: A New Way to Develop a High‐Performance Fluorescence Sensing Film towards Opto‐Electronically Inert Alkanes. Angew Chem Int Ed Engl 2022; 61:e202207619. [DOI: 10.1002/anie.202207619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Zhaolong Wang
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education School of Chemistry and Chemical Engineering Shaanxi Normal University Xi'an 710119 P. R. China
| | - Xinyu Gou
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education School of Chemistry and Chemical Engineering Shaanxi Normal University Xi'an 710119 P. R. China
| | - Qiyuan Shi
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education School of Chemistry and Chemical Engineering Shaanxi Normal University Xi'an 710119 P. R. China
| | - Ke Liu
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education School of Chemistry and Chemical Engineering Shaanxi Normal University Xi'an 710119 P. R. China
| | - Xingmao Chang
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education School of Chemistry and Chemical Engineering Shaanxi Normal University Xi'an 710119 P. R. China
| | - Gang Wang
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education School of Chemistry and Chemical Engineering Shaanxi Normal University Xi'an 710119 P. R. China
| | - Wenjun Xu
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education School of Chemistry and Chemical Engineering Shaanxi Normal University Xi'an 710119 P. R. China
| | - Simin Lin
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education School of Chemistry and Chemical Engineering Shaanxi Normal University Xi'an 710119 P. R. China
| | - Taihong Liu
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education School of Chemistry and Chemical Engineering Shaanxi Normal University Xi'an 710119 P. R. China
| | - Yu Fang
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education School of Chemistry and Chemical Engineering Shaanxi Normal University Xi'an 710119 P. R. China
| |
Collapse
|
2
|
Wang Z, Gou X, Shi Q, Liu K, Chang X, Wang G, Xu W, Lin S, Liu T, Fang Y. Through‐Space Charge Transfer: A New Way to Develop High‐Performance Fluorescence Sensing Film towards Opto‐Electronically Inert Alkanes. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202207619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Zhaolong Wang
- Shaanxi Normal University School of Chemistry and Chemical Engineering CHINA
| | - Xinyu Gou
- Shaanxi Normal University Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education CHINA
| | - Qiyuan Shi
- Shaanxi Normal University School of Chemistry and Chemical Engineering CHINA
| | - Ke Liu
- Shaanxi Normal University School of Chemistry and Chemical Engineering CHINA
| | - Xingmao Chang
- Shaanxi Normal University School of Chemistry and Chemical Engineering CHINA
| | - Gang Wang
- Shaanxi Normal University School of Chemistry and Chemical Engineering CHINA
| | - Wenjun Xu
- Shaanxi Normal University School of Chemistry and Chemical Engineering CHINA
| | - Simin Lin
- Shaanxi Normal University School of Chemistry and Chemical Engineering CHINA
| | - Taihong Liu
- Shaanxi Normal University School of Chemistry and Chemical Engineering CHINA
| | - Yu Fang
- Shaanxi Normal University School of Chemistry and Chemical Engineering 199 South Chang'an Road 710119 Xi'an CHINA
| |
Collapse
|
3
|
Garcia HD. Acceptable Limits for n-Hexane in Spacecraft Atmospheres. Aerosp Med Hum Perform 2021; 92:956-961. [PMID: 34986934 DOI: 10.3357/amhp.5942.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
INTRODUCTION:The Spacecraft Maximum Allowable Concentrations (SMACs) for C2-C9 alkanes set by NASA in 2008 under the guidance and approval of the National Research Council specifically excluded SMACs for n-hexane. Unlike other C2-C9 alkanes, n-hexane can cause polyneuropathy after metabolism in humans or rodents and so requires more stringent SMACs than the other members of this group do. This document reviews the relevant published studies of n-hexane toxicity to develop exposure duration-specific SMACs for n-hexane of 200 ppm for 1 hour, 30 ppm for 24 hours, and 2.4 ppm for 7 days, 30 days, 180 days, and 1000 days.Garcia HD. Acceptable limits for n-hexane in spacecraft atmospheres. Aerosp Med Hum Perform. 2021; 92(12):956-961.
Collapse
|
4
|
Li S, Guan H, Zhang Y, Li S, Li K, Hu S, Zuo E, Zhang C, Zhang X, Gong G, Wang R, Piao F. Bone marrow mesenchymal stem cells promote remyelination in spinal cord by driving oligodendrocyte progenitor cell differentiation via TNFα/RelB-Hes1 pathway: a rat model study of 2,5-hexanedione-induced neurotoxicity. Stem Cell Res Ther 2021; 12:436. [PMID: 34348774 PMCID: PMC8336089 DOI: 10.1186/s13287-021-02518-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 07/18/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND N-hexane, with its metabolite 2,5-hexanedine (HD), is an industrial hazardous material. Chronic hexane exposure causes segmental demyelination in the peripheral nerves, and high-dose intoxication may also affect central nervous system. Demyelinating conditions are difficult to treat and stem cell therapy using bone marrow mesenchymal stem cells (BMSCs) is a promising novel strategy. Our previous study found that BMSCs promoted motor function recovery in rats modeling hexane neurotoxicity. This work aimed to explore the underlying mechanisms and focused on the changes in spinal cord. METHODS Sprague Dawley rats were intoxicated with HD (400 mg/kg/day, i.p, for 5 weeks). A bolus of BMSCs (5 × 107 cells/kg) was injected via tail vein. Demyelination and remyelination of the spinal cord before and after BMSC treatment were examined microscopically. Cultured oligodendrocyte progenitor cells (OPCs) were incubated with HD ± BMSC-derived conditional medium (BMSC-CM). OPC differentiation was studied by immunostaining and morphometric analysis. The expressional changes of Hes1, a transcription factor negatively regulating OPC-differentiation, were studied. The upstream Notch1 and TNFα/RelB pathways were studied, and some key signaling molecules were measured. The correlation between neurotrophin NGF and TNFα was also investigated. Statistical significance was evaluated using one-way ANOVA and performed using SPSS 13.0. RESULTS The demyelinating damage by HD and remyelination by BMSCs were evidenced by electron microscopy, LFB staining and NG2/MBP immunohistochemistry. In vitro cultured OPCs showed more differentiation after incubation with BMSC-CM. Hes1 expression was found to be significantly increased by HD and decreased by BMSC or BMSC-CM. The change of Hes1 was found, however, independent of Notch1 activation, but dependent on TNFα/RelB signaling. HD was found to increase TNFα, RelB and Hes1 expression, and BMSCs were found to have the opposite effect. Addition of recombinant TNFα to OPCs or RelB overexpression similarly caused upregulation of Hes1 expression. The secretion of NGF by BMSC and activation of NGF receptor was found important for suppression of TNFα production in OPCs. CONCLUSIONS Our findings demonstrated that BMSCs promote remyelination in the spinal cord of HD-exposed rats via TNFα/RelB-Hes1 pathway, providing novel insights for evaluating and further exploring the therapeutical effect of BMSCs on demyelinating neurodegenerative disease.
Collapse
Affiliation(s)
- Shuangyue Li
- School of Public Health, Dalian Medical University, Dalian, Liaoning, 116044, People's Republic of China
| | - Huai Guan
- Department of Obstetrics and Gynecology, No. 967 Hospital of the Joint Logistics Support Force of the Chinese PLA, Dalian, People's Republic of China
| | - Yan Zhang
- School of Public Health, Dalian Medical University, Dalian, Liaoning, 116044, People's Republic of China.,Xunyi Center for Disease Control and Prevention, Xunyi, Shanxi, 711300, People's Republic of China
| | - Sheng Li
- Department of Biochemistry, Dalian Medical University, Dalian, Liaoning, 116044, People's Republic of China
| | - Kaixin Li
- School of Public Health, Dalian Medical University, Dalian, Liaoning, 116044, People's Republic of China.,Xian Center for Disease Control and Prevention, Xian, 710054, People's Republic of China
| | - Shuhai Hu
- College of Stomatology, Dalian Medical University, Dalian, Liaoning, 116044, People's Republic of China
| | - Enjun Zuo
- College of Stomatology, Dalian Medical University, Dalian, Liaoning, 116044, People's Republic of China
| | - Cong Zhang
- School of Public Health, Dalian Medical University, Dalian, Liaoning, 116044, People's Republic of China
| | - Xin Zhang
- Department of Clinical Nutrition, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, 116011, People's Republic of China
| | - Guanyu Gong
- Integrative Laboratory, Affiliated Zhongshan Hospital of Dalian University, Dalian, 116001, People's Republic of China. .,Department of Medical Oncology, Affiliated Zhongshan Hospital of Dalian University, Dalian, People's Republic of China.
| | - Ruoyu Wang
- Integrative Laboratory, Affiliated Zhongshan Hospital of Dalian University, Dalian, 116001, People's Republic of China.
| | - Fengyuan Piao
- Integrative Laboratory, Affiliated Zhongshan Hospital of Dalian University, Dalian, 116001, People's Republic of China.
| |
Collapse
|
5
|
Spencer PS, Chen X. The Role of Protein Adduction in Toxic Neuropathies of Exogenous and Endogenous Origin. TOXICS 2021; 9:toxics9050098. [PMID: 33946924 PMCID: PMC8146965 DOI: 10.3390/toxics9050098] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 04/20/2021] [Accepted: 04/24/2021] [Indexed: 02/07/2023]
Abstract
The peripheral (axonal) neuropathy associated with repeated exposure to aliphatic and aromatic solvents that form protein-reactive γ-diketones shares some clinical and neuropathological features with certain metabolic neuropathies, including type-II diabetic neuropathy and uremic neuropathy, and with the largely sub-clinical nerve damage associated with old age. These conditions may be linked by metabolites that adduct and cross-link neuroproteins required for the maintenance of axonal transport and nerve fiber integrity in the peripheral and central nervous system.
Collapse
Affiliation(s)
- Peter S. Spencer
- Department of Neurology, School of Medicine, and Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR 97239, USA
- Correspondence:
| | - Xiao Chen
- Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Medical Key Subject of Health Toxicology (2020–2024), Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China;
| |
Collapse
|
6
|
Alabdulhadi A, Ramadan A, Devey P, Boggess M, Guest M. Inhalation exposure to volatile organic compounds in the printing industry. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2019; 69:1142-1169. [PMID: 31184550 DOI: 10.1080/10962247.2019.1629355] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 05/21/2019] [Accepted: 05/22/2019] [Indexed: 05/25/2023]
Abstract
This study reports on the occupational inhalation exposure to VOCs of workers in the Kuwaiti printing industry. Using the evacuated canister methodology, we targeted 72 VOCs in three printeries and compared the concentrations to previous reports and relevant occupational exposure levels (OELs). We found that recent efforts in the printing industry to reduce VOC usage had been successful, as concentrations of key hazardous VOCs were substantially lower than anticipated. On the other hand, nearly all target VOCs were found. Non-production areas were sampled along with the offset printing areas, another strength of this study, and revealed exposures to hazardous VOCs among administers and digital printer and CTP operators. Exposure to ototoxic VOCs amounted to 1-3% of the OEL, consisting mostly of ethylbenzene, which was likely in use in two of the study printeries. Exposure to carcinogenic or probably carcinogenic VOCs was 15-20% of the OEL at four locations across the three printeries, consisting mostly of vinyl chloride and benzyl chloride. Vinyl chloride VOC was partially sourced from outdoors, but was also likely used inside the study printeries. Interestingly, concentrations of vinyl chloride were similar in most sampling locations to that of CFC-114, a CFC banned by the Montreal Protocol and not commonly used as a refrigerant. This unexpected finding suggests further study is warranted to identify the use of these VOCs in printeries. Exposure to hazardous VOCs up to nearly 50% of the OEL, consisting largely of bromoform and vinyl chloride. Bromoform was found in all the study printeries, sourced partially from outdoor air. The higher concentrations found inside the study printeries likely resulted from the use of the desalinated water for washing. This finding raises of emissions from sources other than blanket washes, and inks, etc. adding to the total VOC load in printery indoor air. Implications: Results from this study indicate that efforts to reduce worker exposure to VOCs particularly dangerous to human health in recent years have been successful, but there is still much to be done to protect workers. Exposures to ototoxic and carcinogenic VOCs were identified, among both production and non-production workers. Unexpected findings included the apparent use in printing activities of the carcinogen vinyl chloride and CFC-114, banned under the Montreal Protocol. Observed lapses in safety procedures included failure to utilize ventilation systems and closing doors between work areas, indicating management and worker education should remain a priority.
Collapse
Affiliation(s)
- Abdullah Alabdulhadi
- School of Health Sciences, Faculty of Health and Medicine, University of Newcastle , Callaghan , NSW , Australia
- Public Authority of Applied Education and Training , Shuwaikh , Kuwaitu
| | - Ashraf Ramadan
- Kuwait Institute of Scientific Research , Safat , Kuwait
| | - Peter Devey
- School of Health Sciences, Faculty of Health and Medicine, University of Newcastle , Callaghan , NSW , Australia
| | - May Boggess
- School of Mathematical and Statistical Sciences, Arizona State University , Tempe , AZ , USA
| | - Maya Guest
- School of Health Sciences, Faculty of Health and Medicine, University of Newcastle , Callaghan , NSW , Australia
| |
Collapse
|
7
|
Chaqda M, El Mellakh M, Kissani N, Louhab N. Neuropathy caused by addictive inhalation of n-hexane in glue sniffers. Presse Med 2019; 48:568-572. [PMID: 31064686 DOI: 10.1016/j.lpm.2019.04.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 11/08/2018] [Accepted: 04/04/2019] [Indexed: 11/26/2022] Open
Affiliation(s)
- Mustapha Chaqda
- University Hospital Mohammed VI, Neurology department, No. 132 Talloujt 2, Daoudiat, Marrakesh, Morocco.
| | - Meriem El Mellakh
- University Hospital Mohammed VI, Neurology department, No. 132 Talloujt 2, Daoudiat, Marrakesh, Morocco
| | - Najib Kissani
- University Hospital Mohammed VI, Neurology department, No. 132 Talloujt 2, Daoudiat, Marrakesh, Morocco
| | - Nisrine Louhab
- University Hospital Mohammed VI, Neurology department, No. 132 Talloujt 2, Daoudiat, Marrakesh, Morocco
| |
Collapse
|
8
|
n-Hexane intoxication in a Chinese medicine pharmaceutical plant: a case report. J Med Case Rep 2017; 11:120. [PMID: 28454586 PMCID: PMC5410082 DOI: 10.1186/s13256-017-1280-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Accepted: 03/30/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND n-Hexane is a well-known neurotoxicant. Polyneuropathy due to occupational n-hexane exposure has been reported worldwide, however, our case is the first report in the Chinese herb industry. CASE PRESENTATION A 25-year-old Asian man experienced progressive weakness and numbness in his hands and feet after working as an operator in a Chinese medicine pharmaceutical plant for the manufacture of Chinese herbal pain relief patches for 10 months. Electrophysiological studies indicated a reduction in nerve conduction velocity, prolongation of distal latencies, mildly positive sharp waves, and reduced recruitment with polyphasic potentials, particularly at distal sites. Demyelination with axonal degeneration caused by occupational n-hexane exposure was strongly suspected. Through investigation of our patient's workplace, the ambient n-hexane concentration in air was found to considerably exceed the permissible exposure limit/time-weighted average for n-hexane in Taiwan. His symptoms were gradually relieved after 4 months of cessation of exposure to n-hexane. He was then confirmed as a case of occupational n-hexane intoxication. Further effective control measures should be implemented as soon as possible to prevent exposure of workers to n-hexane. CONCLUSIONS Despite a typical clinical presentation, his exposure at workplace was appropriately investigated. Chemical exposure in Chinese medicine pharmaceutical plants could be an emerging issue that may affect workers' health. The lack of knowledge and management of solvents could endanger the health of workers. This case has profound educational implications for occupational health and is worthy of further follow-up for improving hazards control.
Collapse
|
9
|
Corn germ-bran oils extracted with alcoholic solvents: Extraction yield, oil composition and evaluation of protein solubility of defatted meal. FOOD AND BIOPRODUCTS PROCESSING 2016. [DOI: 10.1016/j.fbp.2016.06.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
|
10
|
Beckman S, Eisen EA, Bates MN, Liu S, Haegerstrom-Portnoy G, Hammond SK. Acquired Color Vision Defects and Hexane Exposure: A Study of San Francisco Bay Area Automotive Mechanics. Am J Epidemiol 2016; 183:969-76. [PMID: 27188942 DOI: 10.1093/aje/kwv328] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 11/18/2015] [Indexed: 11/13/2022] Open
Abstract
Occupational exposure to solvents, including n-hexane, has been associated with acquired color vision defects. Blue-yellow defects are most common and may be due to neurotoxicity or retinal damage. Acetone may potentiate the neurotoxicity of n-hexane. We present results on nonhexane solvent and hexane exposure and color vision from a cross-sectional study of 835 automotive repair workers in the San Francisco Bay Area, California (2007-2013). Cumulative exposure was estimated from self-reported work history, and color vision was assessed using the Lanthony desaturated D-15 panel test. Log-binomial regression was used to estimate prevalence ratios for color vision defects. Acquired color vision defects were present in 29% of participants, of which 70% were blue-yellow. Elevated prevalence ratios were found for nonhexane solvent exposure, with a maximum of 1.31 (95% confidence interval (CI): 0.86, 2.00) for blue-yellow. Among participants aged ≤50 years, the prevalence ratio for blue-yellow defects was 2.17 (95% CI: 1.03, 4.56) in the highest quartile of nonhexane solvent exposure and 1.62 (95% CI: 0.97, 2.72) in the highest category of exposure to hexane with acetone coexposure. Cumulative exposures to hexane and nonhexane solvents in the highest exposure categories were associated with elevated prevalence ratios for color vision defects in younger participants.
Collapse
|
11
|
Wang C, Bunes BR, Xu M, Wu N, Yang X, Gross DE, Zang L. Interfacial Donor–Acceptor Nanofibril Composites for Selective Alkane Vapor Detection. ACS Sens 2016. [DOI: 10.1021/acssensors.6b00018] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Chen Wang
- Nano
Institute of Utah and Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, United States
| | - Benjamin R. Bunes
- Nano
Institute of Utah and Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, United States
| | - Miao Xu
- Nano
Institute of Utah and Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, United States
| | - Na Wu
- Nano
Institute of Utah and Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, United States
| | - Xiaomei Yang
- Nano
Institute of Utah and Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, United States
| | - Dustin E. Gross
- Department
of Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Ling Zang
- Nano
Institute of Utah and Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, United States
| |
Collapse
|
12
|
Puri V, Gupta AD, Chaudhry N, Saran RK. Reversible cerebral and brain stem dysfunction in n: Hexane neuropathy. Ann Indian Acad Neurol 2015; 18:464-7. [PMID: 26713026 PMCID: PMC4683893 DOI: 10.4103/0972-2327.160088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A 18-year-old male, screen printer by profession developed sensory motor polyneuropathy, change in his behavior, bilateral 6th and 7th cranial nerve palsies, down beat nystagmus and cerebellar dysarthria. He had bilaterally prolonged P100 latency; left: 137 ms; right: 144 ms. P 37 was not recordable on either side while N 20 was normal. The inter latency difference between Ipsilateral R2 and Contralateral R2 was 6.15 ms, on the left side and normal on the right side. In the follow-up, there was normalization of the blink reflex study, improvement in P100 latency [left: 114 ms; right: 120 ms.] but worsening of peripheral nerve conductions. The sequential clinical recovery was of the behavioral dysfunction, down beat nystagmus, 6th nerve, 7th nerve involvement and ataxia, in that order. Sural nerve biopsy showed loss of large diameter myelinated fibers.
Collapse
Affiliation(s)
- Vinod Puri
- Department of Neurology, Govind Ballabh Pant Institute of Post Graduate Medical Education and Research, New Delhi, India
| | - Abhijit Das Gupta
- Department of Neurology, Govind Ballabh Pant Institute of Post Graduate Medical Education and Research, New Delhi, India
| | - Neera Chaudhry
- Department of Neurology, Govind Ballabh Pant Institute of Post Graduate Medical Education and Research, New Delhi, India
| | - Ravindra Kumar Saran
- Department of Pathology, Govind Ballabh Pant Institute of Post Graduate Medical Education and Research, New Delhi, India
| |
Collapse
|
13
|
Juárez-Pérez CA, Torres-Valenzuela A, Haro-García LC, Borja-Aburto VH, Aguilar-Madrid G. Ototoxicity effects of low exposure to solvent mixture among paint manufacturing workers. Int J Audiol 2014; 53:370-6. [DOI: 10.3109/14992027.2014.888597] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
14
|
Occupational neurotoxic diseases in taiwan. Saf Health Work 2012; 3:257-67. [PMID: 23251841 PMCID: PMC3521924 DOI: 10.5491/shaw.2012.3.4.257] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 09/24/2012] [Accepted: 09/24/2012] [Indexed: 11/26/2022] Open
Abstract
Occupational neurotoxic diseases have become increasingly common in Taiwan due to industrialization. Over the past 40 years, Taiwan has transformed from an agricultural society to an industrial society. The most common neurotoxic diseases also changed from organophosphate poisoning to heavy metal intoxication, and then to organic solvent and semiconductor agent poisoning. The nervous system is particularly vulnerable to toxic agents because of its high metabolic rate. Neurological manifestations may be transient or permanent, and may range from cognitive dysfunction, cerebellar ataxia, Parkinsonism, sensorimotor neuropathy and autonomic dysfunction to neuromuscular junction disorders. This study attempts to provide a review of the major outbreaks of occupational neurotoxins from 1968 to 2012. A total of 16 occupational neurotoxins, including organophosphates, toxic gases, heavy metals, organic solvents, and other toxic chemicals, were reviewed. Peer-reviewed articles related to the electrophysiology, neuroimaging, treatment and long-term follow up of these neurotoxic diseases were also obtained. The heavy metals involved consisted of lead, manganese, organic tin, mercury, arsenic, and thallium. The organic solvents included n-hexane, toluene, mixed solvents and carbon disulfide. Toxic gases such as carbon monoxide, and hydrogen sulfide were also included, along with toxic chemicals including polychlorinated biphenyls, tetramethylammonium hydroxide, organophosphates, and dimethylamine borane. In addition we attempted to correlate these events to the timeline of industrial development in Taiwan. By researching this topic, the hope is that it may help other developing countries to improve industrial hygiene and promote occupational safety and health care during the process of industrialization.
Collapse
|
15
|
Vyskocil A, Truchon G, Leroux T, Lemay F, Gendron M, Gagnon F, Majidi NE, Boudjerida A, Lim S, Emond C, Viau C. A weight of evidence approach for the assessment of the ototoxic potential of industrial chemicals. Toxicol Ind Health 2011; 28:796-819. [PMID: 22064681 DOI: 10.1177/0748233711425067] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
There is accumulating epidemiological evidence that exposure to some solvents, metals, asphyxiants and other substances in humans is associated with an increased risk of acquiring hearing loss. Furthermore, simultaneous and successive exposure to certain chemicals along with noise can increase the susceptibility to noise-induced hearing loss. There are no regulations that require hearing monitoring of workers who are employed at locations in which occupational exposure to potentially ototoxic chemicals occurs in the absence of noise exposure. This project was undertaken to develop a toxicological database allowing the identification of possible ototoxic substances present in the work environment alone or in combination with noise exposure. Critical toxicological data were compiled for chemical substances included in the Quebec occupational health regulation. The data were evaluated only for noise exposure levels that can be encountered in the workplace and for realistic exposure concentrations up to the short-term exposure limit or ceiling value (CV) or 5 times the 8-h time-weighted average occupational exposure limit (TWA OEL) for human data and up to 100 times the 8-h TWA OEL or CV for animal studies. In total, 224 studies (in 150 articles of which 44 evaluated the combined exposure to noise and a chemical) covering 29 substances were evaluated using a weight of evidence approach. For the majority of cases where potential ototoxicity was previously proposed, there is a paucity of toxicological data in the primary literature. Human and animal studies indicate that lead, styrene, toluene and trichloroethylene are ototoxic and ethyl benzene, n-hexane and p-xylene are possibly ototoxic at concentrations that are relevant to the occupational setting. Carbon monoxide appears to exacerbate noise-induced hearing dysfunction. Toluene interacts with noise to induce more severe hearing losses than the noise alone.
Collapse
Affiliation(s)
- A Vyskocil
- Institut de recherche en santé publique de l'Université de Montréal, Département de santé environnementale et santé au travail, Université de Montréal, Canada.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Central nervous system involvement in n-hexane polyneuropathy demonstrated by MRI and proton MR spectroscopy. Clin Neurol Neurosurg 2011; 113:493-5. [DOI: 10.1016/j.clineuro.2011.01.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Revised: 01/19/2011] [Accepted: 01/22/2011] [Indexed: 11/20/2022]
|
17
|
Vyskocil A, Leroux T, Truchon G, Gendron M, El Majidi N, Viau C. Occupational ototoxicity of n-hexane. Hum Exp Toxicol 2008; 27:471-6. [PMID: 18784199 DOI: 10.1177/0960327108093719] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The ability of chemicals to produce hearing loss themselves or to promote noise-induced hearing loss has been reported for some organic solvents. The objective of this study was to review the literature on the effects of low-level exposure to n-hexane on the auditory system and consider its relevance for occupational settings. Both human and animal investigations were evaluated only for realistic exposure concentrations based on the permissible inhalation exposure limits. In Quebec, the time-weighted average exposure value (TWAEV) for 8 h is 50 ppm. In humans, the upper limit for considering ototoxicity data relevant to the occupational exposure situation was set at five times the TWAEV. Animal data were evaluated only for exposure concentrations up to 100 times the TWAEV. There is no convincing evidence of n-hexane-induced hearing loss in workers. In rats, n-hexane seems to affect auditory function; however, the site of these alterations cannot be determined from the present data. Further studies with sufficient data on the exposure of workers to n-hexane are necessary to make a definitive conclusion. In the interim, we recommend considering n-hexane as a possibly ototoxic agent.
Collapse
Affiliation(s)
- A Vyskocil
- Groupe de recherche interdisciplinaire en santé and Département de santé environnementale et santé au travail, Université de Montréal, Montréal, Québec, Canada.
| | | | | | | | | | | |
Collapse
|
18
|
Abstract
Effective brain function is dependent on precise and complex interactions among neurotransmitters, hormones, enzymes, and electrolytes. Many of the chemically complex substances with which we come into contact can disrupt this intricately balanced system. Toxic substances, whether ingested, inhaled, or absorbed through the skin, may cause an encephalopathic state directly by affecting the brain itself or indirectly by compromising the brain's supportive systems. The article focuses on neurotoxins (heavy metals, solvents and vapors, pesticides, and natural neurotoxins) that directly induce an encephalopathic state.
Collapse
Affiliation(s)
- Tracy Eicher
- Wilford Hall Medical Center, Lackland Air Force Base, 2200 Bergquist Drive, Suite 1/MMCN, TX 78236, USA
| | | |
Collapse
|
19
|
Gong Y, Kishi R, Kasai S, Katakura Y, Fujiwara K, Umemura T, Kondo T, Sato T, Sata F, Tsukishima E, Tozaki S, Kawai T, Miyama Y. Visual dysfunction in workers exposed to a mixture of organic solvents. Neurotoxicology 2003; 24:703-10. [PMID: 12900083 DOI: 10.1016/s0161-813x(03)00034-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The aim of this study was to investigate the relationship between the workers occupationally exposed to a mixture of organic solvents and their visual functions. Here the visual functions included color vision (CV), visual contrast sensitivity (CS) and visual evoked potentials (VEP). Test subjects were 182 workers at 53 furniture factories in the same industrial area of Japan. As control, a group consisted of 96 workers without exposure to any organic solvent was also tested. Exposure assessments were made both by the environmental concentration and biological monitoring. CV and CS tests were carried out for all the subjects. VEP was measured for 21 exposed subjects who were considered to have impaired CV and CS. In the results, the color confusion index (CCI) values of the exposed subjects were significantly higher than that of the age-matched controls (P<0.01). Their CS values were significantly lower than those in the controls at spatial frequencies of 6 and 12 cycles per degree (cpd) (P<0.01 and <0.05, respectively). A significant correlation between the concentration of urinary methylhippuric acid and contrast sensitivity was found by a multiple regression analysis (P<0.05). CCI showed a negative correlation at all spatial frequencies of CS in a simple regression analysis, no abnormal data were found by the VEP test in the exposed subjects who were found to have impaired CV and CS. The results suppose that a low concentration of the mixed organic solvents might affect the retina and optic nerve. However, it needs to be further researched if such an impact affects the Brodmann's areas of visual cortex in the brain.
Collapse
Affiliation(s)
- Yingyan Gong
- Department of Public Health, Hokkaido University Graduate School of Medicine, North 15, West 7, Sapporo 060-8638, Japan.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Abstract
The effect of industrial chemicals on the sensory perception of exposed workers has received scant attention from the medical community to date, and the scientific literature is mainly limited to some case-reports or isolated studies. Possible explanations for this include the complexity of sensory perception, and the lack of agreement among researchers on methods for testing large groups of subjects. Nevertheless, some published studies showed that vision, hearing and olfactory function can be affected by various industrial metals and solvents, and some data exist also for touch and taste. This review discusses the main industrial chemicals involved. The pathogenesis of the toxicity of chemicals to sensory perception may be related to an action on receptors, nerve fibers, and/or the brain; probably, different pathogenetic mechanisms are involved. One of the main problems in this research field is that most of the studies to date evaluated the effect of a single industrial chemical on a single sense: as an example, we know that styrene exposure can impair smell and also hearing and vision but we have little idea whether different senses are impaired in the same worker, or whether each impairment is independent. In addition, workers are frequently exposed to different chemicals: co-exposure may have no effect, or result in both an increase or a decrease of the effect, as was observed for hearing loss, but studies on this aspect are largely insufficient. Research shows that both occupational and environmental exposure to industrial chemicals can affect sense organs, and suggests that the decline of perception with age may be, at least partly, related to this exposure. Nevertheless, available evidence is incomplete, and is largely inadequate for an estimation of a "safe" threshold of exposure. Good quality further research in this field is needed. This is certainly complex and demands adequate resources, but is justified by the ultimate result: the possibility to prevent an avoidable part of the decline in sensory function with age.
Collapse
Affiliation(s)
- Fabriziomaria Gobba
- Cattedra di Medicina del Lavoro, Dipartimento di Scienze Igienistiche, Università di Modena e Reggio Emilia, 41100 (MO) Modena, Italy.
| |
Collapse
|
21
|
Barrueto F, Long H, Nelson LS, Osterhoudt KC. A 17-year-old with weakness. PEDIATRIC CASE REVIEWS (PRINT) 2003; 3:55-9. [PMID: 16222140 DOI: 10.1097/00132584-200301000-00008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Affiliation(s)
- Fermin Barrueto
- Department of Emergency Medicine, New York University School of Medicine-Bellevue Hospital, New York, NY 10016, USA.
| | | | | | | |
Collapse
|
22
|
Abstract
The use of the clinical neurological examination to document abnormal signs in suspected neurotoxic disorders is described, recognizing that identifying an abnormal examination does not establish the cause of the problem. Several forms of quantitative tests of neurological function are discussed, and their application to the evaluation of neurotoxic disorders is reviewed. Although results of such testing are rarely specific for toxic exposure, these measures have important application in sequential evaluations to document small changes in neurologic function over time.
Collapse
Affiliation(s)
- M L Bleecker
- Center for Occupational and Environmental Neurology, Baltimore, MD 21211, USA
| |
Collapse
|
23
|
Altmann L, Sveinsson K, Krämer U, Weishoff-Houben M, Turfeld M, Winneke G, Wiegand H. Visual functions in 6-year-old children in relation to lead and mercury levels. Neurotoxicol Teratol 1998; 20:9-17. [PMID: 9511165 DOI: 10.1016/s0892-0362(97)00070-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Within a larger comparative environmental health screening program in East and West Germany we investigated functions of the developing visual system in field experiments in a total of 384 children living in three different areas. Visual functions were assessed neurophysiologically by visual-evoked potentials (VEPs) and psychophysically by measuring the contrast sensitivity (CS). Blood lead concentrations and urinary mercury levels were used as markers of environmental and/or amalgam-derived exposure, respectively. The relationships among lead and mercury concentrations and the neurophysiological and psychophysical outcomes were investigated by means of linear regression analysis. After adjusting for confounding effects, statistically significant lead-related changes were found only for some of the VEP interpeak latencies, while some of the CS values were significantly reduced with increasing mercury concentrations. All other outcome variables were not significantly related to lead or mercury levels. It is concluded that even at blood lead levels in the range of 14 to 174 micrograms/l and at very low urinary mercury levels subtle changes in visual system functions can be measured.
Collapse
Affiliation(s)
- L Altmann
- Medical Institute of Environmental Hygiene, Heinrich-Heine-University, Düsseldorf, Germany.
| | | | | | | | | | | | | |
Collapse
|
24
|
Abstract
n-Hexane neuropathy has been described after glue sniffing and industrial exposure. Onset may be subacute and reminiscent of Guillain-Barré syndrome. Although the primary pathology is axonal, electrophysiologic evaluation is frequently most remarkable for conduction slowing. We describe a patient with a severe subacute neuropathy following n-hexane exposure via glue sniffing. Although symptoms worsened after termination of exposure ("coasting"), strength gradually improved to near normal. Sources of toxic exposure should be sought in all patients with subacute demyelinating neuropathies.
Collapse
Affiliation(s)
- A G Smith
- Department of Neurology, University of Michigan Medical Center, Ann Arbor 48109, USA
| | | |
Collapse
|
25
|
Abstract
We describe the clinical evaluation of the nervous-system effects of solvent exposure. We review the current evidence in the epidemiological literature on neurotoxicological effects of solvents, and outline methods and issues to be taken into account in assessment of the patient whose symptoms may be related to solvent toxicity. Primary prevention of these disorders is essential, because treatment options are limited.
Collapse
Affiliation(s)
- R F White
- Department of Neurology, Boston University School of Medicine, MA, USA
| | | |
Collapse
|
26
|
Murata K, Araki S. Assessment of autonomic neurotoxicity in occupational and environmental health as determined by ECG R-R interval variability: a review. Am J Ind Med 1996; 30:155-63. [PMID: 8844045 DOI: 10.1002/(sici)1097-0274(199608)30:2<155::aid-ajim6>3.0.co;2-#] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Measurement of heart rate variability (coefficient of variation of ECG R-R intervals, CVRR) provides a useful approach for the objective assessment of the autonomic nervous function. It is noninvasive and clinically practical, although it tends to be distorted by confounding factors such as age, alcohol, and tobacco. Specifically, two component coefficients of variation of the respiratory sinus arrhythmia (RSA) and Mayer wave-related sinus arrhythmia (MWSA) in the CVRR (i.e., C-CVRSA and C-CVMWSA), computed from component spectral powers by autoregressive spectral and component analyses, are expected to reflect parasympathetic and sympathetic functions, respectively. This article is intended to present an overview of research, utilizing the CVRR method including the C-CVRSA and C-CVMWSA, in occupational and environmental health. The available literature, addressing the impact of some chemicals and work-related factors on human autonomic nervous system, indicates that parasympathetic activity appears to be more vulnerable to these factors than does sympathetic activity. Since decreased cardiac vagal tone is associated with an increased risk of sudden cardiac death or coronary artery disease, attention should be directed to further discovery of hazardous factors in the environment and work place, which are likely to affect the autonomic nervous system.
Collapse
Affiliation(s)
- K Murata
- Department of Public Health, Faculty of Medicine, University of Tokyo, Japan
| | | |
Collapse
|
27
|
Kulig K. Clinical Neurotoxicology of Industrial and Agricultural Chemicals. Neurotoxicology 1995. [DOI: 10.1016/b978-012168055-8/50048-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
28
|
Otis JA, Handler JS. Evoked Potential Testing in Clinical Neurotoxicology. Neurotoxicology 1995. [DOI: 10.1016/b978-012168055-8/50058-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
29
|
Jabre JF. Electrophysiological Investigations of Toxic Neuropathies. Neurotoxicology 1995. [DOI: 10.1016/b978-012168055-8/50057-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
30
|
Oge AM, Yazici J, Boyaciyan A, Eryildiz D, Ornek I, Konyalioğlu R, Cengiz S, Okşak OZ, Asar S, Baslo A. Peripheral and central conduction in n-hexane polyneuropathy. Muscle Nerve 1994; 17:1416-30. [PMID: 7969242 DOI: 10.1002/mus.880171211] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Electrophysiological findings of 27 males with industrial n-hexane polyneuropathy (HPNP) are presented. The results of needle electromyography and nerve conduction studies were compatible with primarily axonal polyneuropathy with secondary segmental demyelination. Motor conduction velocities were the slowest in distal regions of the nerves. In the proximal nerve segments, which were partly tested by magnetic stimulation of the nerve roots, this slowing was much less pronounced. The reduction in mean motor conduction velocities in the forearm segments of ulnar nerves was more than 30% in comparison to the control group means. This reduction was only 10% in the neck-axilla segments. We think that this finding is a reflection of the distal axonopathy process. Central motor conduction times calculated by transcranial magnetic stimulation and spinal nerve root stimulation were found to be prolonged in HPNP patients, indicating that descending motor pathways are affected in human HPNP.
Collapse
Affiliation(s)
- A M Oge
- Department of Neurology, University of Istanbul, Istanbul Faculty of Medicine, Turkey
| | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Stĕtkárová I, Urban P, Procházka B, Lukás E. Somatosensory evoked potentials in workers exposed to toluene and styrene. BRITISH JOURNAL OF INDUSTRIAL MEDICINE 1993; 50:520-7. [PMID: 8329318 PMCID: PMC1035479 DOI: 10.1136/oem.50.6.520] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Somatosensory evoked potentials (SEPs) were used to evaluate possible subclinical impairment of the nervous system due to occupational exposure to toluene and styrene. A group of 36 rotogravure printers with severe exposure to toluene, 20 workers with severe exposure to styrene in a glass laminate manufacturing plant, and a comparison group of healthy subjects were studied. The severity of exposure was documented by measurements of toluene and styrene concentrations in breathing zone air, by hippuric acid concentration in urine in the group exposed to toluene, and by urinary mandelic acid concentration in the group exposed to styrene. Somatosensory evoked potentials were measured by stimulation of the median nerve at the wrist and the tibial nerve at the ankle. Peripheral conduction velocities (CVs) in both extremities and central conduction time (CCT) after tibial nerve stimulation were significantly decreased in both exposed groups. Significantly prolonged latencies of peripheral and cortical SEPs to median nerve stimulation as well as cortical SEPs to tibial nerve stimulation were found in workers exposed to styrene. Some abnormalities in SEPs at peripheral or spinal and cortical levels were found in eight workers exposed to toluene and six workers exposed to styrene. Of these, in three workers exposed to toluene and two to styrene increased CCT and delayed latencies of cortical responses at normal conduction values in the periphery were found. A trend for increased frequency of abnormal SEPs with duration of exposure to toluene and styrene and alcohol abuse was found. Abnormalities in SEPs in the exposed groups are most probably of multifactorial origin. Central SEP abnormalities in both exposed groups could indicate early signs of subclinical dysfunction at spinal and cortical levels and could be due to toluene or styrene exposure probably potentiated by alcohol consumption in the group exposed to toluene.
Collapse
Affiliation(s)
- I Stĕtkárová
- Department of Neurology, Postgraduate Medical School, Thomayer's Hospital, Prague, Czechoslovakia
| | | | | | | |
Collapse
|
32
|
Abstract
A study was made to determine whether children with a significant history of inhalant abuse but who lack clinical evidence of neurological abnormality have abnormal visual, auditory or somatosensory evoked potentials. Visual, auditory and somatosensory evoked potential studies were obtained from 15 such children aged 9-17 years. Eight of the children had abnormal visual or auditory evoked potentials. Somatosensory evoked potentials were normal in all. It was concluded that evoked potentials may serve as an objective marker of early neurological damage in children who abuse inhalants and demonstrate potential usefulness for counselling and intervention.
Collapse
Affiliation(s)
- M Tenenbein
- Department of Paediatrics, University of Manitoba, Canada
| | | |
Collapse
|
33
|
Chang CM, Yu CW, Fong KY, Leung SY, Tsin TW, Yu YL, Cheung TF, Chan SY. N-hexane neuropathy in offset printers. J Neurol Neurosurg Psychiatry 1993; 56:538-42. [PMID: 8505647 PMCID: PMC1015015 DOI: 10.1136/jnnp.56.5.538] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In an offset printing factory with 56 workers, 20 (36%) developed symptomatic peripheral neuropathy due to exposure to n-hexane. Another 26 workers (46%) were found to have subclinical neuropathy. The initial change in the nerve conduction study was reduced amplitude of the sensory action potentials, followed by reduced amplitude of the motor action potentials, reduction in motor conduction velocities and increase in distal latencies. These changes indicate primary axonal degeneration with secondary demyelination. Sural nerve biopsy in a severe case showed giant axonal swellings due to accumulation of 10nm neurofilaments, myelin sheath attenuation and widening of nodal gaps. The development of neuropathy bore no direct relationship to the duration of exposure, hence factors such as individual susceptibility may be important. Optic neuropathy and CNS involvement were uncommon and autonomic neuropathy was not encountered.
Collapse
Affiliation(s)
- C M Chang
- Department of Medicine, University of Hong Kong
| | | | | | | | | | | | | | | |
Collapse
|
34
|
Deschamps D, Garnier R, Lille F, Tran Dinh Y, Bertaux L, Reygagne A, Dally S. Evoked potentials and cerebral blood flow in solvent induced psycho-organic syndrome. BRITISH JOURNAL OF INDUSTRIAL MEDICINE 1993; 50:325-30. [PMID: 8494772 PMCID: PMC1061289 DOI: 10.1136/oem.50.4.325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Epidemiological studies have provided evidence that neuropsychiatric symptoms are induced by long term exposure to solvents; individual diagnosis with psychometric tests, however, is not always possible (for example, when the patient has linguistic difficulties). Therefore evoked potentials and cerebral blood flow were studied in 50 patients occupationally exposed to solvents who were referred to our department and for whom a solvent induced psycho-organic syndrome was suspected. Degree of exposure was evaluated by its duration (mean 13.9, range 1 to 37 years) and its intensity (from an interview). At the group level, P22 and N35 latencies and amplitude N20-P22 of somatosensory evoked potentials were higher in cases than in controls (p < 0.05), whereas there was no difference for brainstem and visual evoked potentials, nor for hemispheric cerebral blood flow (but a higher distribution in the left occipital region was seen in patients, p < 0.05). Some parameters were linked to degree of exposure (amplitude N20-P22 of somatosensory evoked potentials, interpeak latency I-V of brainstem evoked potentials, distribution of cerebral blood flow in the internal frontal left region). At the individual level, these examinations were not of diagnostic value because sensitivity was low.
Collapse
Affiliation(s)
- D Deschamps
- Service de médecine interne et de toxicologie clinique, Hôpital Fernand Widal, Paris, France
| | | | | | | | | | | | | |
Collapse
|
35
|
Discalzi G, Fabbro D, Meliga F, Mocellini A, Capellaro F. Effects of occupational exposure to mercury and lead on brainstem auditory evoked potentials. Int J Psychophysiol 1993; 14:21-5. [PMID: 8432676 DOI: 10.1016/0167-8760(93)90080-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A study was performed to examine the effects of industrial exposures to lead and mercury on the brainstem auditory pathway by recording brainstem auditory evoked potentials (BAEPs). BAEPs were recorded from 22 workers exposed to lead, from eight exposed to mercury and from two control groups of age- and sex-matched subjects never exposed to neurotoxic substances. The time between BAEP peaks I and V were evaluated. The mean durations of exposure were 9.3 and 11.7 years for lead and mercury, respectively. Blood lead concentration (PbBc) on the morning of the test day was 47.5 micrograms/dl, whereas urinary mercury content at the end of the previous work day was 325 micrograms/g creatinine. Both mercury and lead exposed workers showed a significant prolongation of wave I-V time. In addition, the interwave time was longer in a lead subgroup with the greatest mean level of lead in blood. These results are consistent with other studies and show that BAEPs may provide a sensitive tool for detecting subclinical central neurotoxicity caused by lead and mercury.
Collapse
Affiliation(s)
- G Discalzi
- Institute of Occupational Health, University of Turin, Italy
| | | | | | | | | |
Collapse
|
36
|
Abstract
Recent studies of human beings exposed to environmental chemicals, as well as experimental animal studies, have identified a number of chemical agents that are commercial products, chemical intermediaries, waste products, or contaminants that are potentially ototoxic. The classes of compounds discussed in this review include organic solvents, asphyxiant gases, and heavy metals that are present in the environment as industrial pollutants or byproducts. Both human and animal investigations are summarized in discussing the actions of these ototoxic compounds. The suggested gaps in our knowledge are highlighted to help direct future research.
Collapse
Affiliation(s)
- L P Rybak
- Department of Surgery, School of Medicine, Southern Illinois University, Springfield 62794-9230
| |
Collapse
|
37
|
Karlsson JE, Rosengren LE, Haglid KG. Quantitative and qualitative alterations of neuronal and glial intermediate filaments in rat nervous system after exposure to 2,5-hexanedione. J Neurochem 1991; 57:1437-44. [PMID: 1895114 DOI: 10.1111/j.1471-4159.1991.tb08311.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The precise mechanism for the neurotoxicity of 2,5-hexanedione is not known, but cross-linking of neurofilament proteins has been suggested as one possibility. In this study the effects of long-term exposure to 2,5-hexanedione were studied in the rat nervous system with special reference to regional changes in the quantities of neuronal and glial intermediate filaments. Using enzyme-linked immunosorbent assays the concentrations of 68- and 200-kDa neurofilament polypeptides were shown to be reduced in all brain regions studied. Similar results were obtained in the sciatic nerve. The concentration of glial fibrillary acidic protein was decreased in the cerebellar vermis and the dorsal cerebral cortex, whereas it was increased in the spinal cord, a result suggesting a regional variation in glial sensitivity. The intermediate filaments of the exposed animals were also immunoblotted using polyclonal antisera against the various neurofilament polypeptides and glial fibrillary acidic protein. In all tissues studied, several aggregates with molecular weights higher than those of the monomeric polypeptides were demonstrated. Contrary to clinical observations, these data indicate pronounced effects in both CNS and PNS and call for further studies on CNS effects in humans.
Collapse
Affiliation(s)
- J E Karlsson
- Institute of Neurobiology, University of Göteborg, Sweden
| | | | | |
Collapse
|
38
|
Urban P, Lukás E. Visual evoked potentials in rotogravure printers exposed to toluene. BRITISH JOURNAL OF INDUSTRIAL MEDICINE 1990; 47:819-23. [PMID: 2271388 PMCID: PMC1035288 DOI: 10.1136/oem.47.12.819] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Visual evoked potentials (VEPs) from stimulation by checkerboard pattern reversal were examined in 54 rotogravure printers exposed to toluene (all men, aged 22-64 years, duration of exposure 1-41 years). A control group consisted of 46 subjects (23 men and 23 women; aged 22-54 years). Compared with controls the exposed group showed more frequent responses with reduced reproducibility or absence of some waves, or both; the mean P1 wave latency was prolonged and mean amplitudes N1P1 and P1N2 were reduced. The VEPs were abnormal in 24% of workers. The frequency of abnormal VEPs correlated positively with the duration of exposure to toluene and also with the degree of alcohol drinking. No association was found between measurements of VEP and electroencephalogram (EEG) or electromyogram (EMG) examinations. A VEP measurement was made in 78% of the exposed workers two years after the first examination. No statistically significant difference between the two results was found. This suggests a marked stability of the observed VEP changes. These changes can be interpreted as a subclinical sign of dysfunction of the central nervous system (CNS) related to exposure to toluene and also to alcohol consumption.
Collapse
Affiliation(s)
- P Urban
- Centre of Industrial Hygiene and Occupational Diseases, Institute of Hygiene and Epidemiology, Prague, Czechoslovakia
| | | |
Collapse
|
39
|
Abstract
A case of human parkinsonism, due to n-hexane exposure, was recently described. On the basis of this observation, we treated mice and rats with n-hexane and its principle toxic metabolite 2,5-hexanedione. The mice underwent a chronic treatment intraperitoneum, the rats were treated stereotaxically into the substantia nigra. At biochemical analysis of the striata, dopamine and homovanillic acid levels were significantly lower compared with control animals; norepinephrine, serotonin, 5-hydroxindolacetic acid levels were unchanged. The rats treated with 2,5-hexanedione showed an apomorphine-induced rotational behavior significantly higher compared to controls. Since n-hexane and its metabolites are environmental contaminants and by-products of endogenous metabolic pathways, we propose that they may play a role in inducing parkinsonism in humans.
Collapse
Affiliation(s)
- G Pezzoli
- Ospedale Maggiore Policlinico, University of Milan, Italy
| | | | | | | | | |
Collapse
|
40
|
Chang YC. Patients with n-hexane induced polyneuropathy: a clinical follow up. BRITISH JOURNAL OF INDUSTRIAL MEDICINE 1990; 47:485-489. [PMID: 2166555 PMCID: PMC1035212 DOI: 10.1136/oem.47.7.485] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The prognosis of hexacarbon induced polyneuropathy is usually good, though its clinical course after the cessation of exposure has not been described in detail. Eleven patients with moderate to severe n-hexane induced polyneuropathy due to occupational exposure were regularly followed up for a period of four years at the neurological department of the National Taiwan University Hospital. Sensorimotor neuropathy was diagnosed in nine patients and motor neuropathy in two. All were removed from further exposure to n-hexane after aetiological confirmation, but motor disturbance continued to worsen in five cases. Sensory functions were regained earlier than motor functions. All the patients, including one who was tetraplegic and confined to a wheelchair in the early stages, regained their full motor capabilities within one to four years. Three patients with severe neuropathy had residual muscle atrophy in the intrinsic foot and hand muscles. Signs of damage to the central nervous system, including increased tendon reflexes in two patients and leg tightness in six patients, emerged as muscle power was nearing complete recovery. The tightness of the legs gradually disappeared, but muscle cramps of the calves developed and these were still present at the end of follow up. Two patients had mild abnormal colour vision, and the abnormality was still detectable four years later. It is concluded that n-hexane induced neuropathy has a good prognosis, and that spasticity due to damage to the central nervous system is functionally reversible; muscle cramps and dyschromatopsia persist much longer.
Collapse
Affiliation(s)
- Y C Chang
- Department of Neurology, National Taiwan University Hospital, Taipei
| |
Collapse
|
41
|
Huang CC, Chu NS. Evoked potentials in chronic n-hexane intoxication. CLINICAL EEG (ELECTROENCEPHALOGRAPHY) 1989; 20:162-8. [PMID: 2752587 DOI: 10.1177/155005948902000309] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Somatosensory, brainstem auditory and pattern-reversal visual evoked potentials (SEP, BAEP and PVEP) were studied in 5 patients with n-hexane polyneuropathy to determine if the CNS was affected. In SEPs, the median central conduction (N13-to-N20) was normal but the tibial central conduction (N22-to-P40) was delayed. The central conduction time (I-to-V interval) of the BAEP was also prolonged. However, the P100 latency of the PVEP was normal. The present data indicate that the spinal cord and the brainstem are primarily affected in chronic n-hexane intoxication.
Collapse
Affiliation(s)
- C C Huang
- Department of Neurology, Chang Gung Medical College, Taipei, Taiwan, Republic of China
| | | |
Collapse
|
42
|
Cosi V, Callieco R, Galimberti CA, Manni R, Tartara A, Mumford J, Perucca E. Effects of vigabatrin on evoked potentials in epileptic patients. Br J Clin Pharmacol 1989; 27 Suppl 1:61S-68S. [PMID: 2757911 PMCID: PMC1379681 DOI: 10.1111/j.1365-2125.1989.tb03463.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
1. Somatosensory (SEP) brainstem auditory (BAEP) and visual (VEP) evoked potentials were determined before and after add-on administration of vigabatrin (GVG) in patients with epilepsy. 2. At pre-treatment assessment SEP and BAEP parameters were usually found to be within normal limits, while P100 latencies of the VEP were abnormally prolonged in a considerable proportion of patients. 3. In a double-blind, placebo-controlled trial in 22 patients GVG (1-3 g day-1 stratified according to body weight) given for 7 weeks did not modify any of the evoked potential parameters evaluated. 4. Eighteen patients were evaluated prospectively at regular intervals during long-term GVG (2-4 g day-1) therapy with a mean follow up of 24 months (range 13-42 months). SEP, BAEP and especially VEP parameters showed some interindividual variability, but the within patient variation was relatively small. No consistent important changes were seen in association with GVG, although a possible trend towards a shortening of BAEP latencies and P100 latencies was observed. 5. The relevance of these findings with respect to GVG safety is discussed.
Collapse
Affiliation(s)
- V Cosi
- Institute of Neurology C. Mondino, University of Pavia, Italy
| | | | | | | | | | | | | |
Collapse
|