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.

Evaluation Of 90-day Oral Rat Toxicity Studies On The Food Additive, Gum Ghatti

Gum ghatti, a polysaccharide of natural origin, is used in foods as a thickening, gelling, emulsifying and stabilizing agent. In a 90-day toxicity study following Organization for Economic Co-operation and Development (OECD) Guideline #408, male and female Sprague–Dawley rats were exposed to 0 (control), 0.5, 1.5 and 5% gum ghatti in AIN-93M basal diet. Expected [...]

Comparative Histomorphological Review of Rat and Human Hepatocellular Proliferative Lesions

In this comparative review, histomorphological features of common nonneoplastic and neoplastic hepatocyte lesions of rats and humans are examined using H&E-stained slides. The morphological similarities and differences of both neoplastic (hepatocellular carcinoma and hepatocellular adenoma) and presumptive preneoplastic lesions (large and small cell change in humans and foci of cellular alteration in rats) are presented [...]

Regulatory Forum Opinion Piece: The Role of the Toxicologic Pathologist in the Postgenomic Era: Challenges and Opportunities*

The “omics,” high-throughput screening, computational modeling, and database mining revolutions have each arrived with euphoric expectations, considerable hand waving, and promises to set toxicity testing priorities and reduce reliance on conventional animal toxicity and carcinogenicity testing. Reflecting back on prior experience with other predictive approaches and alternatives, what follows the rush to endorse a promising [...]

Tracheal Morphologic and Protein Alterations Following Short-Term Cigarette Mainstream Smoke Exposure to Rats

A short-term 5-day nose-only cigarette smoke exposure study was conducted in Fisher 344 rats to identify smoke-induced tracheal protein changes. Groups of 10 male and female 5 week old rats were assigned to 1 of 4 exposure groups. Animals received filtered air, or 75, 200 or 400 mg total particulate matter (TPM)/m3 of diluted 3R4F [...]

Liver Hypertrophy: A Review of Adaptive (Adverse and Non-adverse) Changes—Conclusions from the 3rd International ESTP Expert Workshop

Preclinical toxicity studies have demonstrated that exposure of laboratory animals to liver enzyme inducers during preclinical safety assessment results in a signature of toxicological changes characterized by an increase in liver weight, hepatocellular hypertrophy, cell proliferation, and, frequently in long-term (life-time) studies, hepatocarcinogenesis. Recent advances over the last decade have revealed that for many xenobiotics, [...]

Evaluation Of The Genotoxicity Of The Food Additive, Gum Ghatti

Gum ghatti is a food additive in some parts of the world, serving as an emulsifier, a stabilizer, and a thickening agent. To evaluate its genotoxic potential, we conducted Good Laboratory Practice compliant in vitro and in vivo studies in accordance with the Organisation for Economic Co-operation and Development (OECD) guidelines. No evidence of toxicity [...]

Responsible Authorship and Publication Practices

Robert R. Maronpot A panel and audience discussion co-sponsored by the International Academy of Toxicologic Pathology (IATP) and the Society of Toxicologic Pathology (STP) at the STP Annual Meeting in Denver in June 2011 generated some lively dialogue. The theme of the ninety-minute session was ‘‘Responsible Authorship and Publication Practices.’’ Following some general introductory comments [...]

Proceedings of the 2010 National Toxicology Program Satellite Symposium

The 2010 annual National Toxicology Program (NTP) Satellite Symposium, entitled ‘‘Pathology Potpourri,’’ was held in Chicago, Illinois, in advance of the scientific symposium sponsored jointly by the Society of Toxicologic Pathology (STP) and the International Federation of Societies of Toxicologic Pathologists (IFSTP). The goal of the annual NTP Symposium is to present current diagnostic pathology [...]

Proliferative and Nonproliferative Lesions of the Rat and Mouse Hepatobiliary System

The INHAND Project (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice) is a joint initiative of the Societies of Toxicologic Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP) and North America (STP) to develop an internationally-accepted nomenclature for proliferative and non-proliferative lesions in laboratory animals. The purpose of this [...]

Liver Enlargement – Hepatic Enzyme Induction: Histopathology

Hepatic enzyme induction is generally an adaptive response associated with increases in liver weight, induction of gene expression, and morphological changes in hepatocytes. The additive growth and functional demands that initiated the response to hepatic enzyme induction cover a wide range of stimuli including pregnancy and lactation, hormonal fluctuations, dietary constituents, infections associated with acute-phase [...]