Showing papers in "Toxicological Sciences in 2006"

TL;DR: Concern was expressed about direct application of the TEF/total toxic equivalency (TEQ) approach to abiotic matrices, such as soil, sediment, etc., for direct application in human risk assessment as the present TEF scheme and TEQ methodology are primarily intended for estimating exposure and risks via oral ingestion.

TL;DR: The toxicological paradigms applicable to the toxicity of inhaled CNT are set out, building on the toxicological database on nanoparticles (NP) and fibers, and the current paradigm for fiber toxicology is discussed.

TL;DR: Data suggest that nano-TiO(2) samples optimized for RS production in photocatalysis are also more likely to generate damaging RS species in cell culture, and highlights the important role that ex vivo measures of RS production can play in developing screens for cytotoxicity.

TL;DR: For some BFRs, the potency to induce AR antagonism, E2SULT inhibition, and TTR competition was higher than for natural ligands or clinical drugs used as positive controls, which support further investigation of the potential ED effects of these environmentally relevant B FRs in man and wildlife.

TL;DR: Magnetic nanoparticles of 50-nm size did not cause apparent toxicity under the experimental conditions of this study, indicating that such nanosized materials can penetrate blood-brain barrier without disturbing its function or producing apparent toxicity.

TL;DR: Recommendations regarding how best to approach nanomaterial characterization include using proper sampling and measurement techniques, forming multidisciplinary teams, and making measurements as close to the biological action point as possible.

TL;DR: This review, combining aspects of particle toxicology, material science, and analytical chemistry, is intended to provide a useful basis for developing relevant dissolution assay(s) for nanoscale particles.

TL;DR: The results described herein provide the first example of nanoscale particle types which are not more cytotoxic or inflammogenic to the lung compared to larger sized particles of similar composition, and run counter to the postulation that surface area is a major factor associated with the pulmonary toxicity of nanoparticles.

TL;DR: It appears most promising to therapeutically target either the initiating event (metabolic activation) or the central propagating event (mitochondrial dysfunction and peroxynitrite formation) to prevent acetaminophen-induced liver cell death.

TL;DR: Interindividual variation in sulfonation capacity may be important in determining an individual's response to xenobiotics, and recent studies have begun to suggest roles for SULT polymorphism in disease susceptibility.

TL;DR: Recent toxicity and exposure data, combined with therapeutic and other related literature, are beginning to shape risk assessments that will be used to regulate the use of nanomaterials in consumer products.

TL;DR: It is shown that quantum dots of different sizes, shapes, and surface coatings can penetrate intact skin at an occupationally relevant dose within the span of an average-length work day, suggesting that skin is surprisingly permeable to nanomaterials with diverse physicochemical properties.

TL;DR: Evidence is provided that gallic acid inhibits mast cell-derived inflammatory allergic reactions by blocking histamine release and pro-inflammatory cytokine expression, and the mechanisms of action are suggested to suggest a possible therapeutic application of this agent in inflammatory allergic diseases.

TL;DR: Data indicate maternal and developmental toxicity of PFOA in the mouse, leading to early pregnancy loss, compromised postnatal survival, delays in general growth and development, and sex-specific alterations in pubertal maturation.

TL;DR: This review aims to provide a comprehensive overview of the state of knowledge regarding the mechanisms by which chemicals interfere with the function of steroidogenic enzymes in various tissues and organisms.

TL;DR: Results clearly demonstrate that nanoscale manganese can deplete DA, DOPAC, and HVA in a dose-dependent manner and further study is required to evaluate the specific intracellular distribution of Mn-40 nm nanoparticles, metal dissolution rates in cells and cellular matrices, and the propensity of Mn nanoparticles to cross the blood-brain barrier or be selectively uptaken by nasal epithelium.

TL;DR: Data show that PPARa is the most likely target of PFOA and PFOS, although PPARg is also activated to some extent, and compared to naturally occurring long-chain fatty acids, these perfluorinated fatty acid analogs were more selective and less potent in their activation of the NRs.

TL;DR: The data presented in this symposium illustrate to the toxicologist the central role played by Kupffer cells in mediating hepatotoxicity.

TL;DR: Unlike polyhydroxylated C60 that exerts mainly antioxidant/cytoprotective and only mild ROS-independent pro-apoptotic activity, pure crystalline C60 seems to be endowed with strong pro-oxidant capacity responsible for the rapid necrotic cell death.

TL;DR: It is demonstrated here that coexposure of zebrafish embryos to the PAH-type AHR agonist beta-naphthoflavone (BNF) and the CYP1A inhibitor alpha- naphth oflav one (ANF) significantly enhanced toxicity above that observed for single-compound exposures, and suggested that mechanisms underlying developmental toxicity of PAH -type A HR agonists are different from those of pHAHs.

TL;DR: In man, arsenic has the ability to alter DNA methylation patterns in gene p53 and p16, which are important in carcinogenesis, which were observed in cases of arsenicosis exposed to high level of arsenic.

TL;DR: OATP 1B3 is identified as the human hepatic uptake transporter for amatoxins and substrates and inhibitors of OATP1B3, among others rifampicin, may be useful for the treatment of human amatoxin poisoning.

TL;DR: The study shows, for the first time, estrogenic activities of UV filters in fish both in vitro and in vivo, and proposes that receptor-based assays should be used for in vitro screening prior to in vivo testing, leading to environmental risk assessments based on combined, complementary, and appropriate species-related assays for hormonal activity.

TL;DR: The different toxicities and mechanisms associated with administration of ligands for the three PPARs will be discussed, and important data gaps that could increase the current understanding of how PPAR ligands lead to toxicity will be highlighted.

TL;DR: It was concluded that the induction of rodent liver tumors by porphyrogenic compounds followed a cytotoxic MOA, and that liver tumors formed as a result of sustained cytotoxicity and regenerative proliferation are considered relevant for evaluating human cancer risk if appropriate metabolism occurs in the animal models and in humans.

TL;DR: The effects were dose-dependent with exposure to 10 mg PFOA/kg, bw/day, causing alteration in expression of the greatest number of genes (over 800), and the largest categories of induced genes were those involved in transport and metabolism of lipids, particularly fatty acids.

TL;DR: The data support the conclusion that endonuclease G and AIF translocate to the nucleus in response to AAP-induced mitochondrial dysfunction and may be responsible, at least in part, for the initial DNA fragmentation during AAP hepatotoxicity.

TL;DR: It is found that curcumin induced DNA damage to both the mitochondrial and nuclear genomes in human hepatoma G2 cells and this data reinforce the hypothesis thatCurcumin plays a conflicting dual role in carcinogenesis.

TL;DR: Understanding of TCDD-mediated gene expression responses is expanded and indicates that species-specific toxicity may be mediated by differences in gene expression which may help explain the wide range of species sensitivities and will have important implications in risk assessment strategies.

TL;DR: Findings suggest that in addition to gestational exposure, abnormal lactational development of dams may play a role in early growth retardation of developmentally exposed offspring.