Alan R Warbritton

Learn More
Topical exposure to nanoscale materials is likely from a variety of sources including sunscreens and cosmetics. Because the in vivo disposition of nanoscale materials is not well understood, we have evaluated the distribution of quantum dots (QDs) following intradermal injection into female SKH-1 hairless mice as a model system for determining tissue(More)
Acetaminophen overdose causes severe hepatotoxicity in humans and laboratory animals, presumably by metabolism to N-acetyl-p-benzoquinone imine: and binding to cysteine groups as 3-(cystein-S-yl)acetaminophen-protein adduct. Antiserum specific for the adduct was used immunohistochemically to demonstrate the formation, distribution, and concentration of this(More)
We recently reported that nitrotyrosine and acetaminophen (APAP)-cysteine protein adducts colocalize in the hepatic centrilobular cells following a toxic dose of APAP to mice. Whereas APAP-adducts are formed by reaction of the metabolite N-acetyl-p-benzoquinone imine with cysteine, nitrotyrosine residues are formed by reaction of tyrosine with(More)
Tattooing is a popular cosmetic practice involving more than 45 million US citizens. Since the toxicology of tattoo inks and pigments used to formulate tattoo inks has not been reported, we studied the immunological impact of tattooing and determined recovery time from this trauma. SKH-1 hairless mice were tattooed using commercial tattoo inks or(More)
Different ovarian follicle counting procedures were investigated to reduce labor while retaining statistical power. Intact ovaries of untreated CD-1 mice (20/group) from National Toxicology Program Reproductive Assessment by Continuous Breeding (RACB) studies were serially sectioned at 6 microm. Mean numbers of small and growing follicles were used to(More)
Acrylamide (AA) is an important industrial chemical that is neurotoxic in rodents and humans and carcinogenic in rodents. The observation of cancer in endocrine-responsive tissues in Fischer 344 rats has prompted hypotheses of hormonal dysregulation, as opposed to DNA damage, as the mechanism for tumor induction by AA. The current investigation examines(More)
The intentional adulteration of pet food with melamine and derivatives, including cyanuric acid, has been implicated in the kidney failure and death of a large number of cats and dogs in the United States. Although individually these compounds present low toxicity, coexposure can lead to the formation of melamine cyanurate crystals in the nephrons and(More)
Coal tar is a complex mixture containing hundreds of compounds, at least 30 of which are polycyclic aromatic hydrocarbons, including the carcinogen benzo[a]pyrene (BaP). Although humans are exposed to complex mixtures on a daily basis, the synergistic or individual effects of components within a mixture on the carcinogenic process remain unclear. We have(More)
Breast cancer is the most common malignancy in women continuing to rise worldwide. Breast cancer emerges through a multi-step process, encompassing progressive changes from a normal cell to hyperplasia (with and without atypia), carcinoma in situ, invasive carcinoma, and metastasis. In the current study, we analyzed the morphological changes and alterations(More)
Ovaries from National Toxicology Program Reproductive Assessment by Continuous Breeding (RACB) bioassays were used to directly compare differential ovarian follicle counts and reproductive performance for 15 chemicals. Ovaries of 10 animals per group from 16 studies in CD-1 mice and 1 study each in C3H and C57BL/6 mice were sectioned serially at 6 microm.(More)