A recent report (Calabrese et al., Mutat. Res. 726 (2011) 91-97) concluded that an analysis of Ames test mutagenicity data provides evidence of hormesis in mutagenicity dose-response relationships. An examination of the data used in this study and the conclusions regarding hormesis reveal a number of concerns regarding the analyses and possible misinterpretations of the Salmonella data. The claim of hormesis is based on test data from the National Toxicology Program using Salmonella strain TA100. Approximately half of the chemicals regarded as hormetic, and the majority of the specific dose-responses identified as hormetic, were actually nonmutagenic. We conclude that the data provide no evidence of hormetic effects. The Ames test is an excellent measure of bacterial mutagenicity, but the numbers of revertant (mutant) colonies on the plate are the result of a complex interaction between mutagenicity and toxicity, which renders the test inappropriate for demonstrating hormesis in bacterial mutagenicity experiments.
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Mutat Res Genet Toxicol Environ Mutagen
January 2025
Research & Development, Kongo Chemical Co., Ltd, Himata, Toyama 9300912, Japan.
Photodegradation of azilsartan yields a phenanthridine derivative (APP). We suspected that APP could be a DNA-reactive substance, since many phenanthridine derivatives are mutagenic. In silico quantitative structure-activity relationship analysis indicated potential mutagenicity of APP, due to DNA reactivity at the 6-aminophenanthridine moiety.
View Article and Find Full Text PDFGeorgian Med News
November 2024
4Department of Pathology, University of Virginia, Charlottesville, USA.
The toxicokinetics of nitrosamines remain a mystery to this day, though it appears that the role of nitrosamines in potentiating the generation of mutations required for the onset of skin cancer continues to be a significant concern. Nitrosamines are mutagens, genotoxic substances, and mediators of phototoxicity/carcinogenicity, whose long-term daily usage, in the context of polypharmacy, can result in the parallel appearance of heterogeneous forms of skin cancer: keratinocytic and melanocytic. But a number of clinical observations suggest that it is the nitrosamines that potentiate the multiple occurrences of skin cancer over the years, or recurrences of skin cancer localized in areas exposed to solar radiation.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Kinesiology, Iowa State University, Ames, Iowa, United States of America.
Purpose: The Youth Activity Profile (YAP) is a 7-day self-report designed to quantify physical activity and sedentary behaviors among youth. This study evaluated the reliability of the online version of the YAP and equivalence with the paper-based version.
Method: A total of 2,490 participants from 17 schools in Iowa and Texas completed the YAP.
J Vet Intern Med
January 2025
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA.
Background: Oxidative injury occurs in septic people, but the role of oxidative stress and antioxidants has rarely been evaluated in foals.
Objectives/hypothesis: To measure reactive oxygen species (ROS), biomarkers of oxidative injury, and antioxidants in neonatal foals. We hypothesized that ill foals would have higher blood concentrations of ROS and biomarkers of oxidative injury and lower concentrations of antioxidants compared to healthy foals.
Behav Sci (Basel)
December 2024
New College of Interdisciplinary Arts and Sciences, Arizona State University, Glendale, AZ 85306, USA.
Inadmissible evidence generally biases jurors toward guilty verdicts; jurors who hear inadmissible evidence are more likely to convict than jurors not exposed to inadmissible evidence-even when evidence is constant. When inadmissible evidence is introduced, the common legal remedy is judicial instructions to jurors to disregard it. Appeals courts repeatedly affirm instructions to disregard as a sufficient safeguard of defendants' constitutional rights, despite research finding that jurors do not disregard when instructed.
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