Isomers and their metabolites of endosulfan induced cytotoxicity and oxidative damage in SH-SY5Y cells.

As an organochlorine insecticide, endosulfan has been widely banned or restricted, but it is still largely used in many developing countries. Previous studies have shown multiple adverse health effects of endosulfan. However, the neurotoxicity of endosulfan has not been fully elucidated. In this study, endosulfan isomers (α-/ß-endosulfan) and their major metabolites (endosulfan sulfate, endosulfan diol, and endosulfan lactone) were, respectively, exposed to human neuroblastoma SH-SY5Y cells. Results showed that both α-endosulfan and ß-endosulfan caused decrease of cell viability and morphological damages in a dose-dependent manner. Their median effective concentrations (EC50s) were respectively 79.6 µM (α-endosulfan) and 50.37 µM (ß-endosulfan) for 72 h exposure. EC50s of α/ß-endosulfan mixture were lower than that of the single isomer. However, EC50s of its metabolites were higher than that of technical endosulfan. Endosulfan and its metabolites caused increases of reactive oxygen species and the lipid peroxidation, but decrease of superoxide dismutase in a dose-dependent manner. These results indicate that α-endosulfan exhibits higher neurotoxicity than ß-endosulfan. Mixture of endosulfan isomers shows stronger cytotoxicity than the single isomer. After endosulfan is degraded, cytotoxicity of its metabolites decreases gradually. The neurotoxicity of endosulfan and its metabolites is closely related to oxidative damage and antioxidative deficit.

Toxicity bioassays for water from black-odor rivers in Wenzhou, China.

Following urbanization, a large number of urban rivers were contaminated and turned to black-odor rivers. The traditional approach for detecting water quality is based on chemical or physical analysis. However, biological toxicity of black-odor water has been less addressed. As two typical black-odor rivers, Jiushanwai River (JS) and Shanxia River (SX) are tributaries of Wen-Rui Tang River in Wenzhou (south of China). The eco-safety of the urban rivers was evaluated by bioassay for water toxicity in this study. Ten and 5 sampling sites were respectively set along JS and SX. Water samples were collected monthly from October 2010 to October 2011. The general physical and chemical parameters of river water were monitored. In order to investigate the ecotoxicological effects of black-odor water, the following bioassays were used: (1) Fish acute toxicity test (Danio rerio, comprehensive toxicity), (2) luminescent bacteria bioassay (Qinghaiensis vibrio, toxicity to bacteria), and (3) tropical claw embryo assay (Xenopus tropicalis, embryo toxicity). Biotoxicity of black-odor rivers water was demonstrated by D. rerio, Q. vibrio, and X. tropicalis embryos. Toxicological effects of black-odor water were respectively shown by mortality of zebrafish, and by the relative inhibitory light rate of luminescent bacteria. However, luminescent bacteria were more sensitive to inspect biotoxicity than zebrafish. In X. tropicalis embryos test, toxicological effects of black-odor water were mostly shown by embryos' survival rate and teratogenic rate. Bioassay results showed that toxicity of SX water was higher than that of JS water, especially in summer. Statistical analysis of luminescent bacteria toxicity test showed that biotoxicity of SX and JS was high in summer, but low in winter and spring. The seasonal changes of water toxicity of the black-odor river were positively correlative with changes of water temperature (p < 0.05), and related to pH and ammonium nitrogen of water. Typical black-odor river water displays different degrees of biotoxicity to D. rerio, luminescent bacteria, and X. tropicalis embryos. The ecotoxicological risk of black-odor rivers was demonstrated in urban area, which suggests bioassay is necessary for evaluation of water quality. In the present study, spatial and seasonal bioassay for toxicity of JS and SX provides a complete example for evaluation of urban rivers.

Functional change of globus pallidus and Parkinson's disease / 中国病理生理杂志

As an important nucleus of basal ganglia, globus pallidus was concerned to involve in the neural mechanism of Parkins's disease (PD). Previous studies of PD patients and animal model indicate that neurotransmitters and receptors are changed in globus pallidus neurons, the balance between inhibition and excitation is broken in the output nuclei of basal ganglia, and globus pallidus neurons display bursting and oscillatory discharge, the synchronous tendency of neighboring neurons enhances. These neurophysiological changes are associated with PD symptoms, such as bradykinesia, rigidity and tremor, which reflects that globus pallidus plays an important role in the process of PD. In the present paper, the recent advances in pathophysiology in globus pallidus, its clinical application in treatment of Parkinson's disease, and the study direction in the future are reviewed.

Effects of Paraquat and Maneb on System of Substantial Nigra and Striatum in Mice / 环境与健康杂志

0.05) before administration and after 8 weeks and 16 weeks of administration. Cell pyknosis and neurodegeneration in substantial nigra were observed in the PQ+MB group for 8 weeks and 16 weeks (P

Iron Element and Parkinson’s Disease / 环境与健康杂志

Iron is abnormally accumulated in the substantia nigra pars compacta (SNc) in Parkinson’s disease (PD) patients. The disorder of iron metabolism and the neurotoxicity induced by excessive iron are proved in PD patients, and these indicate that iron is closely correlative with PD. This article presented an overview of research advances of three aspects including the distribution and metabolism of iron in the brain, the neurotoxicity of iron, and the relationship between the disorder of iron metabolism in central nervous system and PD.