Background: Nanotechnology is developing rapidly throughout the world and the production of novel man-made nanoparticles is increasing, it is therefore of concern that nanomaterials have the potential to affect human health. The purpose of this study was to investigate the effects of maternal exposure to nano-sized anatase titanium dioxide (TiO 2 ) on gene expression in the brain during the developmental period using cDNA microarray analysis combined with Gene Ontology (GO) and Medical Subject Headings (MeSH) terms information.
Background
Particles and fibres affect human health as a function of their properties such as chemical composition, size and shape but also depending on complex interactions in an organism that occur at various levels between particle uptake and target organ responses.
While particulate pollution is one of the leading contributors to the global burden of disease, particles are also increasingly used for medical purposes. Over the past decades we have gained considerable experience in how particle properties and particle-bio interactions are linked to human health. This insight is useful for improved risk management in the case of unwanted health effects but also for developing novel medical therapies. The concepts that help us better understand particles’ and fibres’ risks include the fate of particles in the body; exposure, dosimetry and dose-metrics and the 5 Bs: bioavailability, biopersistence, bioprocessing, biomodification and bioclearance of (nano)particles. This includes the role of the biomolecule corona, immunity and systemic responses, non-specific effects in the lungs and other body parts, particle effects and the developing body, and the link from the natural environment to human health. The importance of these different concepts for the human health risk depends not only on the properties of the particles and fibres, but is also strongly influenced by production, use and disposal scenarios.
Conclusions
Lessons learned from the past can prove helpful for the future of the field, notably for understanding novel particles and fibres and for defining appropriate risk management and governance approaches.
A novel ratiometric nanothermometer based on over-1000 nm near-infrared emission of rare-earth doped ceramic nanophosphors was developed for temperature measurement.
BackgroundEpidemiological studies have suggested that suspended particulate matter (SPM) causes detrimental health effects such as respiratory and cardiovascular diseases, and that diesel exhaust particles from automobiles is a major contributor to SPM. It has been reported that neonatal and adult exposure to diesel exhaust damages the central nervous system (CNS) and induces behavioral alteration. Recently, we have focused on the effects of prenatal exposure to diesel exhaust on the CNS. In this study, we examined the effects of prenatal exposure to low concentration of diesel exhaust on behaviour and the monoaminergic neuron system. Spontaneous locomotor activity (SLA) and monoamine levels in the CNS were assessed.MethodsMice were exposed prenatally to a low concentration of diesel exhaust (171 μg DEP/m3) for 8 hours/day on gestational days 2-16. SLA was assessed for 3 days in 4-week-old mice by analysis of the release of temperature-associated infrared rays. At 5 weeks of age, the mice were sacrificed and the brains were used for analysis by high-performance liquid chromatography (HPLC).Results and DiscussionMice exposed to a low concentration of diesel exhaust showed decreased SLA in the first 60 minutes of exposure. Over the entire test period, the mice exposed prenatally to diesel exhaust showed decreased daily SLA compared to that in control mice, and the SLA in each 3 hour period was decreased when the lights were turned on. Neurotransmitter levels, including dopamine and noradrenaline, were increased in the prefrontal cortex (PFC) in the exposure group compared to the control group. The metabolites of dopamine and noradrenaline also increased in the PFC. Neurotransmitter turnover, an index of neuronal activity, of dopamine and noradrenaline was decreased in various regions of the CNS, including the striatum, in the exposure group. The serum corticosterone level was not different between groups. The data suggest that decreased SLA in mice exposed prenatally to diesel exhaust is due to facilitated release of dopamine in the PFC.ConclusionsThese results indicate that exposure of mice in utero to a low concentration of diesel exhaust decreases SLA and alters the neurochemical monoamine metabolism of several regions of the brain.
We
report on the design and synthesis of a green-emitting iridium complex–peptide
hybrid (IPH) 4, which has an electron-donating hydroxyacetic
acid (glycolic acid) moiety between the Ir core and the peptide part.
It was found that 4 is selectively cytotoxic against
cancer cells, and the dead cells showed a green emission. Mechanistic
studies of cell death indicate that 4 induces a paraptosis-like
cell death through the increase in mitochondrial Ca2+ concentrations
via direct Ca2+ transfer from ER to mitochondria, the loss
of mitochondrial membrane potential (ΔΨm),
and the vacuolization of cytoplasm and intracellular organelle. Although
typical paraptosis and/or autophagy markers were upregulated by 4 through the mitogen-activated protein kinase (MAPK) signaling
pathway, as confirmed by Western blot analysis, autophagy is not the
main pathway in 4-induced cell death. The degradation
of actin, which consists of a cytoskeleton, is also induced by high
concentrations of Ca2+, as evidenced by costaining experiments
using a specific probe. These results will be presented and discussed.
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