Robert Maronpot

/Robert Maronpot

About Robert Maronpot

Dr. Maronpot received his doctorate of veterinary medicine in 1965 from Michigan State University, an MS in nutritional pathology from Michigan State University in 1966, and an MPH from Harvard University in 1972. He is a diplomate of the American College of Veterinary Pathologists as well as the American Board of Toxicology and has worked more than forty years in experimental pathology, with an emphasis on animal models of carcinogenesis.

Immunotoxicity and Environment: Immunodysregulation and Systemic Inflammation in Children

Environmental pollutants, chemicals, and drugs have an impact on children’s immune system development. Mexico City (MC) children exposed to significant concentrations of air pollutants exhibit chronic respiratory inflammation, systemic inflammation, neuroinflammation, and cognitive deficits. We tested the hypothesis that exposure to severe air pollution plays a role in the immune responses of asymptomatic, apparently healthy [...]

Summary of Chemically Induced Pulmonary Lesions in the National Toxicology Program (NTP) Toxicology and Carcinogenesis Studies

The lung is the second most common target site of neoplasia of chemicals tested by the National Toxicology Program (NTP). Of all peer-reviewed NTP studies to date (N = 545), a total of sixty-four chemicals in sixty-six reports produced significant site-specific neoplasia in the lungs of rats and/or mice. Of the studies associated with lung [...]

New Insights into Functional Aspects of Liver Morphology

The liver is structurally and functionally complex and has been considered second only to brain in its complexity. Many mysteries still exist in this heterogeneous tissue whose functional unit of the lobule has continued to stump morphologists for over 300 years. The primary lobule, proposed by Matsumoto in 1979, has been gaining acceptance as the [...]

Carcinogenesis

Cancer, or neoplasia, which occurs in one of every four individuals and results in the death of one of every five individuals in the United States, is a complex disease with multiple causes. Many intrinsic and extrinsic factors influence the development of cancer. Intrinsic or host factors include age, sex, genetic constitution, immune system function, [...]

An Investigation of the Effects of Late-Onset Dietary Restriction on Prostate Cancer Development in the TRAMP Mouse

In our previous work we showed that dietary restriction initiated at puberty reduced prostate cancer development in the TRAMP mouse model. The current study was conducted to ascertain whether a dietary restriction regime would similarly reduce lesion development if imposed once tumor development was well established. Male TRAMP mice were maintained on an ad libitum [...]

Microarray Data Analysis of Mouse Neoplasia

Microarray gene expression analysis offers great promise to help us understand the molecular events of experimental carcinogenesis, but have such promises been fulfilled? Studies of gene expression profiles of rodent are being published and demonstrate that yes, indeed, gene array data is furthering our understanding of tumor biology. Recent studies have identified differentially expressed genes [...]

Brain Inflammation and Alzheimer’s-Like Pathology in Individuals Exposed to Severe Air Pollution

Air pollution is a complex mixture of gases (e.g., ozone), particulate matter, and organic compounds present in outdoor and indoor air. Dogs exposed to severe air pollution exhibit chronic inflammation and acceleration of Alzheimer’s-like pathology, suggesting that the brain is adversely affected by pollutants. We investigated whether residency in cities with high levels of air [...]

Applications of Magnetic Resonance Microscopy

Magnetic resonance imaging (MRI) has enjoyed enormous clinical success since the first demonstration of the method more than 30 years ago. An increasing number of pharmaceutical manufacturers seeking new biomarkers for assessing drug efficacy and toxicity are turning to MRI. A specific application of MRI promises to revolutionize pathology for the basic scientist in the [...]

Prediction of Rodent Carcinogenesis: An Evaluation of Prechronic Liver Lesions as Forecasters of Liver Tumors in NTP Carcinogenicity Studies

The National Toxicology Program (NTP) developed the chronic 2-year bioassay as a mechanism for predicting the carcinogenic potential of chemicals in humans. The cost and duration of these studies has limited their use to small numbers of selected chemicals. Many different short-term methods aimed at increasing predictive accuracy and the number of chemicals evaluated have [...]

Follicular Epithelial Cell Hypertrophy Induced by Chronic Oral Administration of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin in Female Harlan Sprague–Dawley Rats

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) affects the thyroid morphologically and/or functionally in adult animals. Recently, the National Toxicology Program conducted a 2-year gavage study of TCDD in female Harlan Sprague–Dawley rats. The only treatment-related alterations found in thyroid follicles were decreased luminal size and increased height of the follicular epithelial cells, without prominent protrusion into the lumen. The [...]