George A. Parker

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Perfluorooctanesulfonate (PFOS), a persistent and bioaccumulative compound, is widely distributed in humans and wildlife. Exposure of the human fetus and neonate to PFOS can occur in utero and via the mother's milk, respectively. Developmental studies have been conducted with PFOS in the past, including some developmental neurotoxicity endpoints. The(More)
Perfluorooctanesulfonate (PFOS), a persistent and accumulative compound, is widely distributed in humans and wildlife. Human exposure can occur early in development, as evidenced by the detection of PFOS in umbilical cord blood and breast milk. As part of a developmental neurotoxicology study for which developmental endpoints, including those related to the(More)
The evolution of the subdiscipline of developmental immunotoxicology (DIT) as it exists today has been shaped by significant regulatory pressures as well as key scientific advances. This review considers the role played by legislation to protect children's health, and on the emergence of immunotoxcity and developmental immunotoxicity guidelines, as well as(More)
The objective of this study was to evaluate the pathology time course of the LRRK2 knockout rat model of Parkinson's disease at 1-, 2-, 4-, 8-, 12-, and 16-months of age. The evaluation consisted of histopathology and ultrastructure examination of selected organs, including the kidneys, lungs, spleen, heart, and liver, as well as hematology, serum, and(More)
A retrospective study of 15 thymomas in domestic animals showed four animals had antemortem signs of dyspnea and grossly visible lumps in the thoracic inlet. The neoplasms were single, multilobulated, encapsulated masses in the anterior mediastinum or thoracic inlet. Cells with clear cytoplasm comprised the bulk of two canine thymomas, whereas the remaining(More)
The liver is the primary hematopoietic organ of the mammalian body during the fetal stage. The postnatal liver retains immunologically important functions and contains a substantial population of immunologically active cells, including T and B lymphocytes, Kupffer cells, liver-adapted natural killer (NK) cells (pit cells), natural killer cells expressing T(More)
Hibernomas are rare neoplasms originating in brown adipose tissue of humans and other animal species, including laboratory animals. Background incidence values for these tumors in all common strains of laboratory rats are generally accepted as being <0.1%. Between April 2000 and April 2007, however, sixty-two hibernomas (an overall prevalence of 3.52%) were(More)
Rats were gavaged with 60, 48, 38, 30, or 24 ml/kg of either petroleum (P) or shale (S)-derived distillate fuel, marine (DFM). Surviving rats were killed 14 days after dosing. There was a slight difference in toxicity of the two fuels but neither fuel was very toxic. The LD50/14 was 43 ml/kg for P-DFM and 50 ml/kg for S-DFM. Lesions in rats that died(More)