Zhang S, Niu Q, Gao H, Ma R, Lei R, Zhang C, Xia T, Li P, Xu C, Wang C, Chen J, Dong L, Zhao Q, Wang A. Excessive apoptosis and defective autophagy contribute to developmental testicular toxicity induced by fluoride. Environmental Pollution. 2016 Jan 31;212:97-104. doi: 10.1016/j.envpol.2016.01.059.
Fluoride, a ubiquitous environmental contaminant, is known to impair testicular functions and fertility; however the underlying mechanisms remain obscure. In this study, we used a rat model to mimic human exposure and sought to investigate the roles of apoptosis and autophagy in testicular toxicity of fluoride. Sprague-Dawley rats were developmentally exposed to 25, 50, or 100 mg/L sodium fluoride (NaF) via drinking water from pre-pregnancy to post-puberty, and then the testes of offspring were excised on postnatal day 56. Our results demonstrated that developmental NaF exposure induced an enhanced testicular apoptosis, as manifested by a series of hallmarks such as caspase-3 activation, chromatin condensation and DNA fragmentation. Further study revealed that fluoride exposure elicited significant elevations in the levels of cell surface death receptor Fas with a parallel increase in cytoplasmic cytochrome c, indicating the involvement of both extrinsic and intrinsic apoptotic pathways. Intriguingly, fluoride treatment also simultaneously increased the number of autophagosomes and the levels of autophagy marker LC3-II but not Beclin1. Unexpectedly, the expression of p62, a substrate that is degraded by autophagy, was also significantly elevated, suggesting that the accumulated autophagosomes resulted from impaired autophagy degradation rather than increased formation. Importantly, these were associated with marked histopathological lesions including spermatogenic failure and germ cell loss, along with severe ultrastructural abnormalities in testes. Taken together, our findings provide deeper insights into roles of excessive apoptosis and defective autophagy in the aggravation of testicular damage, which could contribute to a better understanding of fluoride-induced male reproductive toxicity.
Environmentalists like to claim skeptics are making money off hampering global warming regulations, but those same greens are making a lot of money promoting global warming alarmism. Earlier this week, the Feds even took down a green energy scheme that took $1.4 million from taxpayers. click here
” “The president’s decision to treat the Paris agreement as an executive agreement instead of a treaty is just his latest use of executive power to achieve an end that he knows full well would not pass congressional muster,” Steven Groves, a lawyer who is an expert on treaties at The Heritage Foundation, testified Tuesday before a congressional committee.” click here
“Hillary Clinton has been using her campaign website to obscure the foreign policy debacles that marked her disastrous tenure as Secretary of State.” click here for article.
Li J, Moe B, Vemula S, Wang W, Li XF. Emerging Disinfection Byproducts, Halobenzoquinones: Effects of Isomeric Structure and Halogen Substitution on Cytotoxicity, Formation of Reactive Oxygen Species, and Genotoxicity. Environmental Science and Technology. 2016 Jan 26.
Halobenzoquinones (HBQs) are a structurally diverse class of water disinfection byproducts. Here, we report a systematic study on the effects of isomeric structure and the type and number of halogen substitutions of HBQs on their cytotoxicity, formation of reactive oxygen species (ROS), and genotoxicity. Dynamic responses and IC50 histograms were obtained using real time cell analysis, clearly ranking the cytotoxicity of the HBQs in Chinese hamster ovary (CHO-K1) cells. Strong isomeric structure effects were shown with 2,5-HBQ isomers inducing greater cytotoxicity than their corresponding 2,6-HBQ isomers (P<0.05). HBQ-halogen substitution groups also influence cytotoxicity, as cytotoxicity increases across the di-halogenated HBQs: iodo- > bromo- > chloro-HBQs (P<0.05). Determination of HBQ-induced ROS further supports isomeric structure and halogen substitution effects. HBQ-induced genotoxicity was shown as increased levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG) and p53 protein. Pearson correlation analysis of the HBQ toxicity measurements with their physicochemical parameters demonstrates that dipole moment and the lowest unoccupied molecular orbital energy are two major structural influences on toxicity (r=-0.721 or -0.766, P < 0.05). Dipole moment also correlates with isomer toxicity. This study suggests that formation and occurrence of highly toxic iodo-HBQs and 2,5-HBQs warrant further investigation to fully assess the impact of HBQs in drinking water.
El Nino apparently caused a much greater increase in global temperature in 2015 than any “global warming”. The informative essay is here.
Climate changes happen. Alarming statements over insignificant “signals” is not advancing the discussion forward.
Luckmann J, Grethe H, McDonald S. When water saving limits recycling: Modelling economy-wide linkages of wastewater use. Water Research. 2016 Jan 1;88:972-80. doi: 10.1016/j.watres.2015.11.004.
The reclamation of wastewater is an increasingly important water source in parts of the world. It is claimed that wastewater recycling is a cheap and reliable form of water supply, which preserves water resources and is economically efficient. However, the quantity of reclaimed wastewater depends on water consumption by economic agents connected to a sewage system. This study uses a Computable General Equilibrium (CGE) model to analyse such a cascading water system. A case study of Israel shows that failing to include this linkage can lead to an overestimation of the potential of wastewater recycling, especially when economic agents engage in water saving.