Copper ions influence the toxicity of β-amyloid(1-42) in a concentration-dependent manner in a Caenorhabditis elegans model of Alzheimer's disease.

β-amyloid (Aβ) and copper play important roles in the pathogenesis of Alzheimer's disease (AD). However, the behavioral correlativity and molecular mechanisms of Aβ and copper toxicity have been investigated less often. In the present study, we investigated the interaction and toxicity of Aβ1-42 and copper in the Aβ1-42 transgenic Caenorhabditis elegans worm model CL2006.

Effects of copper nanoparticles on the development of zebrafish embryos.

The environmental behavior and the potential toxicity of copper nanoparticles (nano-Cu) in water are major concerns for assessing their environmental safety. The present study was undertaken to characterize the properties of nano-Cu in E3 medium, such as size changes, solubility, zeta-potential and pH, and to test the toxicity of nano-Cu suspension to zebrafish embryos. Dynamic light scattering and solubility experiments showed that three components coexisted in the nano-Cu exposure system, including small nano-Cu aggregates still suspended in E3 medium, large nano-Cu aggregates deposited on the container bottom and dissolved copper species (Cu(dis)).

Overexpression of mitochondrial ferritin sensitizes cells to oxidative stress via an iron-mediated mechanism.

Mitochondrial ferritin (MtFt) is a newly identified H-ferritin-like protein expressed only in mitochondria. Previous studies have shown that its overexpression markedly affects intracellular iron homeostasis and rescues defects caused by frataxin deficiency. To assess how MtFt exerts its function under oxidative stress conditions, MtFt overexpressing cells were treated with tert-butyl-hydroperoxide (tBHP), and the effects of MtFt expression on cell survival and iron homeostasis were examined.

Ytterbium and trace element distribution in brain and organic tissues of offspring rats after prenatal and postnatal exposure to ytterbium.

Lanthanides, because of their diversified physical and chemical effects, have been widely used in a number of fields. As a result, more and more lanthanides are entering the environment and eventually accumulating in the human body. Previous studies indicate that the impact of lanthanides on brain function cannot be neglected.

Effect of iodine supplement on iodine status and 5'-deiodinase activity in the brain of neonatal rats with iodine deficiency.

The weanling Wistar rats of iodine deficiency were divided into three groups for supplementation of different levels of iodine (iodine-excessive [IE], iodine-adequate [IA], and iodine-deficient [ID]), with a control group (C). The iodine content in the thyroid was determined by epithermal neutron activation analysis. The activities of 5'-deiodinase and 5-deiodinase in the brains were assayed by determining the conversion ratios of T4 to T3 and rT3, respectively.

Delayed changes in T1-weighted signal intensity in a rat model of 15-minute transient focal ischemia studied by magnetic resonance imaging/spectroscopy and synchrotron radiation X-ray fluorescence.

Previous studies have found that rats subjected to 15-min transient middle cerebral artery occlusion (MCAO) show neurodegeneration in the dorsolateral striatum only, and the resulting striatal lesion is associated with increased T1-weighted (T1W) signal intensity (SI) and decreased T2-weighted (T2W) SI at 2-8 weeks after the initial ischemia. It has been shown that the delayed increase in T1W SI in the ischemic region is associated with deposition of paramagnetic manganese ions. However, it has been suggested that other mechanisms, such as tissue calcification and lipid accumulation, also contribute to the relaxation time changes.

Nicotine attenuates beta-amyloid-induced neurotoxicity by regulating metal homeostasis.

Nicotine reduces beta-amyloidosis and has a beneficial effect against Alzheimer's disease (AD), but the underlying mechanism is not clear. The abnormal interactions of beta-amyloid (Abeta) with metal ions such as copper and zinc are implicated in the process of Abeta deposition in AD brains. In the present study, we investigated the effect of nicotine on metal homeostasis in the hippocampus and cortex of APP(V717I) (London mutant form of APP) transgenic mice.

Neurotoxicological consequence of long-term exposure to lanthanum.

Lanthanides, because of their diversified physical and chemical effects, have been widely used in a number of fields. As a result, more and more lanthanides are entering into the environment and eventually accumulated in human body. Recently, a new medicine, lanthanum carbonate (Fosrenol), has been used to treat chronic renal failure (CRF), and the dosage is much higher than the daily intake of lanthanides.

Long-term effects of lanthanum intake on the neurobehavioral development of the rat.

The effects of subchronic exposure to lanthanum on rats' physical and neurobehavioral development were investigated. Wistar rats were exposed to lanthanum through oral administration at 0, 0.1, 2, and 40 mg/kg concentrations from gestation day 0 through 5 months of age.

[Effects of various iodin-nutritional on activity of T4 5'-and 5-deiodinase in rat brain].

Objective: To investigate the changing of T4 5'-and 5-deiodinase within rat brain under various iodin-nutritional states.

Methods: Animal model of iodine-deficiency rat was performed and the rats were divided into 4 groups by the intake of iodine-nutrition, and then killed at an age of 20 days. The thyroid hormones level in serum was measured by ELISA and the activity of T(4) 5'-and 5-deiodinase within brain was analyzed.

The effects of meso-2,3-dimercaptosuccinic acid and oligomeric procyanidins on acute lead neurotoxicity in rat hippocampus.

Oxidative stress is considered to be a mechanism involved in lead neurotoxicity. Apoptosis is also thought to relate to lead neurotoxicity. The present study, focused on the hippocampus, was designed to investigate the two possible mechanisms involved in lead neurotoxicity and the potential protective effects of 2,3-dimercaptosuccinic acid (DMSA) and oligomeric procyanidins (OPC).

Study of trace elements in blood of thyroid disorder subjects before and after 131I therapy.

Both trace elements and thyroid hormones play essential roles in the human body. However, the previous results about the interaction between these two factors are often controversially given. In order to make clear the influence of thyroid hormones on the homeostasis of trace elements, we studied the variation of Fe, Cu, and Zn in erythrocyte and serum from patients with hyperthyroidism before and after 131I therapy by the X-ray fluorescence method.

Variations of elemental distribution in brain regions of neonatal rats at different iodine intakes.

Iodine deficiency (ID) can result in irreversible damage to the brain during the fetal and neonatal stages. As the active center of many enzymes, trace elements play essential roles in brain function. In this work, the relative contents and distributions of elements (Cl, Br, Fe, Cu, and Zn) in two important brain regions, the cerebral cortex and hippocampus, of the iodine-deficient model rats were determined by the synchrotron radiation X-ray fluorescence (SRXRF) method.