Publications by authors named "M A Tirmenstein"

Article Synopsis
  • - The study developed a 2-stage model to explore urinary bladder cancer in male Sprague-Dawley rats by first initiating tumors with a chemical called BBN and then testing potential tumor promoters over a 26-week period.
  • - Rats treated with rosiglitazone and uracil showed a significant increase in bladder tumors, with uracil being the most effective, leading to a high percentage of transitional cell carcinomas (TCCs).
  • - Sodium ascorbate appeared to have a protective effect, reducing the development of bladder cell hyperplasia without promoting tumor formation, confirming the model's effectiveness in identifying tumor promoters.
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PEGylation is a proven approach to prolonging the duration of action and enhancing biophysical solubility and stability of peptides. 4-Acetylphenylalanine is a novel amino acid with a ketone side chain that is uniquely reactive in proteins. The ketone functionality can react with an aminooxy functionalized polyethyleneglycol polymer to form a stable oxime adduct of the protein.

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Pancreatic injury in rats is primarily detected through histopathological changes and conventional serum biomarkers such as amylase and lipase. However, amylase and lipase have a short half-life and are markers of acinar, not islet cell injury. We investigated whether circulating microRNA (miR) levels that are enriched in acinar cells (miR-217, miR-216a/b) or islet cells (miR-375) could serve as markers of pancreatic injury.

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Conventional circulating biomarkers of cardiac and skeletal muscle (SKM) toxicity lack specificity and/or have a short half-life. MicroRNAs (miRNAs) are currently being assessed as biomarkers of tissue injury based on their long half-life in blood and selective expression in certain tissues. To assess the utility of miRNAs as biomarkers of cardiac and SKM injury, male Sprague-Dawley rats received a single dose of isoproterenol (ISO); metaproterenol (MET); allylamine (AAM); mitoxantrone (MIT); acetaminophen (APAP) or vehicle.

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Glucokinase (GK) catalyzes the initial step in glycolysis and is a key regulator of glucose homeostasis. Therefore, glucokinase activators (GKa) have potential benefit in treating type 2 diabetes. Administration of a Bristol-Myers Squibb GKa (BMS-820132) to healthy euglycemic Sprague-Dawley (SD) rats and beagle dogs in 1 mo toxicology studies resulted in marked and extended hypoglycemia with associated clinical signs of toxicity and degenerative histopathological changes in the stomach, sciatic nerve, myocardium, and skeletal muscles at exposures comparable to those expected at therapeutic clinical exposures.

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