Flow cytometric evaluation of the potential of metal oxide nanoparticles for skin sensitization using 5-Bromo-2-deoxyuridine.

Although skin sensitization potential of various chemicals has been extensively studied, there are only a few reports on nanoparticles induced skin sensitization. Aiming to fill this lacuna, in this study we evaluated the potential of metal oxide nanoparticles (NPs) to induce skin sensitization with flow cytometry. Seven different metal oxide NPs, including copper oxide, cobalt oxide, nickel oxide, titanium oxide, cerium oxide, iron oxide, and zinc oxide were applied to Balb/c mice.

Evaluation of the skin sensitization potential of metal oxide nanoparticles using the ARE-Nrf2 Luciferase KeratinoSens assay.

Numerous studies have reported the potential of chemicals for inducing skin sensitization; however, few studies have examined skin sensitization induced by nanomaterials. This study aimed to evaluate skin sensitization induced by metal oxide nanoparticles (NPs) using the ARE-Nrf2 Luciferase KeratinoSens™ assay. Seven different metal oxide NPs, including copper oxide, cobalt oxide, nickel oxide, titanium oxide, cerium oxide, iron oxide, and zinc oxide, were assessed on KeratinoSens™ cells.

Single- and repeated-dose 28-day oral toxicity study of MDM hydantoin in Sprague-Dawley rats.

1-(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione (MDM hydantoin) is a commonly used antiseptic preservative in cosmetics. However, limited toxicity information data are available for this chemical. The aim of this study was to obtain toxicity data for MDM hydantoin through single- and repeated-dose toxicity studies in Sprague-Dawley (SD) rats.

Orally Administered 6:2 Chlorinated Polyfluorinated Ether Sulfonate (F-53B) Causes Thyroid Dysfunction in Rats.

The compound 6:2 chlorinated polyfluorinated ether sulfonate (F-53B), a replacement for perfluorooctanesulfonate (PFOS) in the electroplating industry, has been widely detected in numerous environmental matrices, human sera, and organisms. Due to regulations that limit PFOS use, F-53B use is expected to increase. Therefore, in this study, we performed a subchronic oral toxicity study of F-53B in Sprague Dawley (SD) rats.

The role of surface functionalization on the pulmonary inflammogenicity and translocation into mediastinal lymph nodes of graphene nanoplatelets in rats.

Graphene, a two-dimensional monocrystalline layer of carbon atoms, has potential in many applications not only in material sciences, but also in the biomedical fields, but there is little information about the role of surface modification on the toxicity of graphene-based nanomaterials. Here, we evaluated the role of surface functionalization of the graphene nanoplatelets (GNPs) on the pulmonary inflammogenicity and translocation into mediastinal lymph nodes using a rat intratracheal instillation model. Six types of GNPs were used: All types of GNPs were based on the pristine GNPs (GNP), and different functional groups were conjugated onto them including a COOH (GNP), COH [Formula: see text], N-H [Formula: see text], F (GNP), and N=H [Formula: see text].

Organ-specific distribution of gold nanoparticles by their surface functionalization.

The behavior and fate of intravenously (i.v.) injected nanoparticles (NPs) can be controlled by several physicochemical factors including size, shape and surface charge.

Lactational coumestrol exposure increases ovarian apoptosis in adult rats.

This study is the first to examine the increased apoptosis in the adult rat ovary after lactational exposure to coumestrol (COU), a potent phytoestrogen. Lactating dams were gavaged at doses of 0.01, 0.

Differentiation of endothelial cells derived from mouse embryoid bodies: a possible in vitro vasculogenesis model.

Mouse embryonic stem cells (mES cells), which are pluripotent and self-renewal cells, are derived from the inner cell mass of mouse blastocysts. The objective of this study was to construct more efficient mES cell-derived embryoid bodies (EBs) for use as a vasculogenesis model and as an in vitro vascular toxicity testing model. EBs were formed for 3 days using hanging drop cultures and plated on gelatin-coated plates in endothelial growth medium-2 (EGM-2) to promote vascular development.

Assessment of estrogenic and androgenic activities of tetramethrin in vitro and in vivo assays.

Tetramethrin, a synthetic pyrethroid insecticide, is used globally for agriculture, and thus potential environmental exposure to tetramethrin is a concern. Environmental chemicals that are hormonally active (particularly estrogen or androgen) may adversely affect the reproductive and endocrine systems. However, little is known about the estrogenic and androgenic activities of tetramethrin.

Multigeneration reproductive and developmental toxicity study of bar gene inserted into genetically modified potato on rats.

Each specific protein has an individual gene encoding it, and a foreign gene introduced to a plant can be used to synthesize a new protein. The identification of potential reproductive and developmental toxicity from novel proteins produced by genetically modified (GM) crops is a difficult task. A science-based risk assessment is needed in order to use GM crops as a conventional foodstuff.

Neurotoxic effects of alcohol and acetaldehyde during embryonic development.

Alcohol drinking during pregnancy results in abnormal fetal development, including fetal alcohol syndrome (FAS) in humans and experimental animals. FAS is characterized by two major effects, including central nervous system (CNS) dysfunction and multiple anomalies recognizable mainly as a typical face. However, the mechanisms of alcohol-induced embryotoxicity have not been clearly demonstrated.

Potential estrogenic and antiandrogenic effects of permethrin in rats.

Many environmental chemicals including pesticides have been reported to possess hormonal activities, and thus are classified as endocrine disruptors. Permethrin, a synthetic pyrethroid insecticide, is used worldwide, which provides potential environmental exposure. However, relatively few studies have reported on hormonal activities, particularly estrogenic and androgenic activities of permethrin, and the results of these studies are in some respects contradictory.

Differential gene profiles in developing embryo and fetus after in utero exposure to ethanol.

Alcohol consumption during pregnancy results in morphological abnormalities in the fetuses of humans and experimental animals, and is referred to as fetal alcohol syndrome (FAS). However, the molecular mechanism underlying FAS has not been completely elucidated. The aim of the present study was to investigate the potential molecular mechanisms of ethanol-induced FAS in the developing embryo and fetus.

Mechanism of antifertility in male rats treated with 3-monochloro-1,2-propanediol (3-MCPD).

3-Monochloro-1,2-propanediol (3-MCPD) is a food contaminant that is often found in foods containing acid-hydrolyzed (AH) protein, like seasonings and savory food products. The purpose of the present study was to investigate the effects of 3-MCPD on male fertility, sperm, and hormonal levels and its antifertility mechanism. In vivo male fertility testing was performed to observe the adverse effects of 3-MCPD on the functioning of the male reproductive system and pregnancy outcome.

No androgenic/anti-androgenic effects of bisphenol-A in Hershberger assay using immature castrated rats.

Several studies have demonstrated that bisphenol A (BPA) exhibited weak estrogenic activity in the 3-day uterotrophic assay using ovariectomized (OVX) and immature rats (Toxicol. Lett. 115 (2000) 231; Regul.

Comparative estrogenic effects of p-nonylphenol by 3-day uterotrophic assay and female pubertal onset assay.

Nonylphenol (NP) is widely used as a component of detergents, paints, pesticides, and many other formulated products. Several studies have demonstrated that NP is estrogenic in fish, avian, and mammalian cells. NP also competitively inhibits the binding of 17 beta-estradiol (E2) to the estrogen receptor (ER).

Evaluation of the 20-day pubertal female assay in Sprague-Dawley rats treated with DES, tamoxifen, testosterone, and flutamide.

The Endocrine Disrupter Screening and Testing Advisory Committee (EDSTAC) has recommended the rodent pubertal female assay as a Tier I test to detect potential endocrine disrupters (EDs). This assay is designed to screen estrogenic activity in immature rats exposed to chemicals during sexual maturation. The aim of this study was to evaluate whether this assay can detect the EDs with effects brought about through various mechanisms.

Effects of flutamide on puberty in male rats: an evaluation of the protocol for the assessment of pubertal development and thyroid function.

To establish a test protocol for the rodent 20-d thyroid/pubertal assay, flutamide, a non-steroidal androgen antagonist, was administered to intact male Sprague-Dawley rats from postnatal d 33 for 20 d, and several reproductive endpoints were examined to assess the sensitivity of a number of parameters with respect to the detection of endocrine-related effects. Immature male rats were divided into 4 groups and given flutamide once daily by oral gavage at doses of 0, 1, 5, or 25 mg/kg/d. Prepuce separation was significantly delayed in flutamide-treated rats (5 and 25 mg/kg/d).