Lung cancer mortality among aircraft manufacturing workers with long-term, low-level, hexavalent chromium exposure.

Hexavalent chromium (CrVI) is known to cause lung cancer among workers exposed to high concentrations in certain historical industries. It is also a toxic air contaminant considered to pose a potentially significant cancer risk at comparatively low concentrations in urban air. However, very limited data currently exist to quantify risk at low-concentration occupational or environmental exposures.

Chemistry domain of applicability evaluation against existing estrogen receptor high-throughput assay-based activity models.

Introduction: The U. S. Environmental Protection Agency's Endocrine Disruptor Screening Program (EDSP) Tier 1 assays are used to screen for potential endocrine system-disrupting chemicals.

Optimizing androgen receptor prioritization using high-throughput assay-based activity models.

Computational models using data from high-throughput screening assays have promise for prioritizing and screening chemicals for testing under the U.S. Environmental Protection Agency's Endocrine Disruptor Screening Program (EDSP).

Estimating Hepatotoxic Doses Using High-Content Imaging in Primary Hepatocytes.

Using in vitro data to estimate point of departure (POD) values is an essential component of new approach methodologies (NAMs)-based chemical risk assessments. In this case study, we evaluated a NAM for hepatotoxicity based on rat primary hepatocytes, high-content imaging (HCI), and toxicokinetic modeling. First, we treated rat primary hepatocytes with 10 concentrations (0.

Molecular characterization of a toxicological tipping point during human stem cell differentiation.

Endoderm gives rise to the gut tube in the early embryo. We differentiated human induced pluripotent stem cells (hiPSCs) to embryonic endoderm to identify a "tipping point" at which the developing system did not recover from perturbations caused by exposure to all-trans retinoic acid (ATRA). Differentiating hiPSC-derived endoderm exposed to five concentrations of ATRA between 0.

Modeling order-disorder transition in Low-Density Lipoprotein.

Low Density Lipoproteins (LDL) undergo a reversible order-disorder thermal transition close to biological temperature due to cooperative melting of the cholesteryl esters (CE) in the core of the LDL particle. We have noticed that chain-chain interactions between CE molecules are responsible for the stability of the ordered smectic phase; thus, we formulated a simple "coarse-grained" two-state model to describe the melting process. In this model only nearest neighbor interactions are allowed.

Ordering and stability in lipid droplets with applications to low-density lipoproteins.

In this article, we present a framework for investigating the order-disorder transition in lipid droplets using the standard Ising model. While a single lipid droplet is itself a complex system whose constituent cholesteryl esters each possesses many degrees of freedom, we present justification for using this effective approach to isolate the underlying physics. It is argued that the behavior of the esters confined within lipid droplets is significantly different from that of a bulk system of similar esters, which is adequately described by continuum mean-field theory in the thermodynamic limit.