Documents central nervous system 8 results

"Treatment and diagnosis of neurodegenerative diseases and other CNS disorders are nowadays considered some of the most challenging tasks in modern medicine. The development of effective strategies for the prevention, diagnosis and treatment of CNS pathologies require better understanding of neurological disorders that is still lacking. The use of nanomaterials is thought to contribute to our further understanding of the CNS and the development of novel therapeutic and diagnostic modalities for neurological interventions. Even though the application of nanoparticles in neuroscience is still embryonic, this article attempts to illustrate the use of different types of nanomaterials and the way in which they have been used in various CNS applications in an attempt to limit or reverse neuropathological processes."

"Although humans have been exposed to airborne nanosized particles (NSPs ; < 100 nm) throughout their evolutionary stages, such exposure has increased dramatically over the last century due to anthropogenic sources. The rapidly developing field of nanotechnology is likely to become yet another source through inhalation, ingestion, skin uptake, and injection of engineered nanomaterials. Information about safety and potential hazards is urgently needed. Results of older biokinetic studies with NSPs and newer epidemiologic and toxicologic studies with airborne ultrafine particles can be viewed as the basis for the expanding field of nanotoxicology, which can be defined as safety evaluation of engineered nanostructures and nanodevices. Collectively, some emerging concepts of nanotoxicology can be identified from the results of these studies. When inhaled, specific sizes of NSPs are efficiently deposited by diffusional mechanisms in all regions of the respiratory tract. The small size facilitates uptake into cells and transcytosis across epithelial and endothelial cells into the blood and lymph circulation to reach potentially sensitive target sites such as bone marrow, lymph nodes, spleen, and heart. Access to the central nervous system and ganglia via translocation along axons and dendrites of neurons has also been observed. NSPs penetrating the skin distribute via uptake into lymphatic channels. Endocytosis and biokinetics are largely dependent on NSP surface chemistry (coating) and in vivo surface modifications. The greater surface area per mass compared with larger-sized particles of the same chemistry renders NSPs more active biologically. This activity includes a potential for inflammatory and pro-oxidant, but also antioxidant, activity, which can explain early findings showing mixed results in terms of toxicity of NSPs to environmentally relevant species. Evidence of mitochondrial distribution and oxidative stress response after NSP endocytosis points to a need for basic research on their interactions with subcellular structures. Additional considerations for assessing safety of engineered NSPs include careful selections of appropriate and relevant doses/concentrations, the likelihood of increased effects in a compromised organism, and also the benefits of possible desirable effects. An interdisciplinary team approach (e.g., toxicology, materials science, medicine, molecular biology, and bioinformatics, to name a few) is mandatory for nanotoxicology research to arrive at an appropriate risk assessment."

A case/control study of occupational risk factors for central nervous system (CNS) malignancies by examining the death certificates of United States (US) workers was conducted. The cases consisted of 28,416 workers who died from brain cancer between 1984 and 1992 identified from a national death certificate database. The database, which was maintained by the National Cancer Institute, NIOSH, and the National Center for Health Statistics, collected and coded death certificates from 24 states. Controls were 113,664 deaths from other causes identified from the database. Associations between CNS cancer risk and employment in 354 industries and 377 occupations as coded in the 1980 US census were evaluated by case/control techniques. Associations between CNS malignancies and electromagnetic fields (EMF), solvents, herbicides, other pesticides, contact with the public, contact with animals, and lead (7439921) were assessed from job exposure matrices (JEMs) for each industry and occupation. Significant increases in CNS cancer risk were seen for employment in 50 specific industries. When analyzed across gender and race, these increases were seen for employment in textile mills, paper mills, printing and publishing, petroleum refining, motor vehicle manufacturing, telephone and electrical utilities, health care services, and care services, and elementary and secondary schools and colleges and universities. Employment in agricultural industries was associated with an increased CNS cancer risk for white men and women. Significant CNS cancer risks were seen in 51 occupations. Consistent increases were seen for employment as administrators in education and related fields, secondary school teachers, and other education and health related occupations. The JEMS showed slight increases in CNS cancer risk associated with exposure to solvents. Exposure to EMF was not associated with a significant increase in CNS cancer risk, but associations with employment in a few electrical occupations such as electrical power installers and repairers were seen. The authors conclude that several occupations are associated with an increase in CNS cancer risk.

"Based on toxicology, metabolism, animal studies, and human studies, occupational exposure to chlorinated aliphatic solvents (methanes, ethanes, and ethenes) has been associated with numerous adverse health effects, including central nervous system, reproductive, liver, and kidney toxicity, and carcinogenicity. However, many of these solvents remain in active, large-volume use. This article reviews the recent occupational epidemiology literature on the most widely used solvents, methylene chloride, chloroform, trichloroethylene, and tetrachloroethylene, and discusses other chlorinated aliphatics. The impact of studies to date has been lessened because of small study size, inability to control for confounding factors, particularly smoking and mixed occupational exposures, and the lack of evidence for a solid pathway from occupational exposure to biological evidence of exposure, to precursors of health effects, and to health effects. International differences in exposure limits may provide a "natural experiment" in the coming years if countries that have lowered exposure limits subsequently experience decreased adverse health effects among exposed workers. Such decreases could provide some evidence that higher levels of adverse health effects were associated with higher levels of solvent exposure. The definitive studies, which should be prospective biomarker studies incorporating body "

"Ethylene glycol alkyl ethers (EGAE), 2-methoxyethanol, 2-ethoxyethanol, 2-isopropoxyethanol, and 2-butoxyethanol, are widely used in a variety of industrial and household products. They are found in a number of paints, varnishes, engine fuels, hydraulic fluids, and also in many household products, including floor polishes and glass, leather, and upholstery cleaners. Human and animal studies have shown that EGAE can cause adverse reproductive, developmental, and hematological effects through inhalation, dermal absorption, and ingestion. The oxidation of these chemicals to appropriate aldehydes and alkoxyacetic acids is responsible for their toxic effects. The central nervous system, blood and blood-forming organs, and reproduction are the targets in acute and chronic intoxications with EGAE. Data on exposure, metabolism, biomonitoring, and toxic effects ofEGAE, especially those on hematological disorders in human and laboratory animals are presented in this paper."

"PURPOSE:
Evidence of whether exposure to extremely low-frequency magnetic fields (ELF-MF) is related to central nervous system diseases is inconsistent. This study updates a previous study of the incidence of such diseases in a large cohort of Danish utility workers by almost doubling the period of follow-up.
METHODS:
We investigated the risks for dementia, motor neurone disease, Parkinson disease, multiple sclerosis and epilepsy among 32,006 men employed at the 99 utility companies that supplied Denmark with electricity during the period 1900-1993. Cases were identified in the Danish National Patient Registry and the cohort was followed during 1982-2010. Exposure was estimated from a job-exposure matrix based on company records of job title and area of work and cohort members were allocated to one of three categories (<0.1, 0.1-0.99 and ?1.0 µT).
RESULTS:
For dementia, multiple sclerosis and epilepsy the incidence rate ratios (IRR) were close to unity, but higher for motor neurone disease [IRR 1.24, 95% confidence interval (CI) 0.86-1.79] and lower for Parkinson disease (IRR 0.81, 95% CI 0.67-0.97) among workers exposed to ?0.1 µT compared with the Danish population. For the highest level of exposure (?1.0 µT), IRRs of 1.44, 1.78, 1.40 and 1.34 were observed for dementia, motor neurone disease, multiple sclerosis and epilepsy, respectively.
CONCLUSIONS:
We observed elevated risks of dementia, motor neurone disease, multiple sclerosis and epilepsy and lower risks of Parkinson disease in relation to exposure to ELF-MF in a large cohort of utility employees."