To check the reliability of the Ames MPS paper spot test, which is based on the Azure A dye, we sent a series of urine samples to three laboratories where the spot test is part of the metabolic screening for mucopolysaccharidoses. In these laboratories false-negative results ranged between 19% and 35% and false-positive results ranged between 12% and 29% of all samples submitted. In contrast, t...

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 cla...

OBJECTIVES We investigated the genotoxic effects of 40-59 nm silver nanoparticles (Ag-NPs) by bacterial reverse mutation assay (Ames test), in vitro comet assay and micronucleus (MN) assay. In particular, we directly compared the effect of cytochalasin B (cytoB) and rat liver homogenate (S9 mix) in the formation of MN by Ag-NPs. METHODS Before testing, we confirmed that Ag-NPs were completely...

INTRODUCTION Many studies on the biological effects of electric and magnetic fields have been conducted since Wertheimer and Leeper reported an association between wiring configuration and childhood cancer among residents in Denver, Colorado. The genetic effects, especially mutagenicity and carcinogenicity, of electromagnetic fields have also been studied experimentally with positive and negati...

In this paper we describe an initial reproducibility study of 12 proprietary compounds followed by the assessment of 51 marketed pharmaceuticals and, lastly, a summary of the data so far from 2698 proprietary compounds from the Johnson & Johnson (J&J) compound library, in the yeast GreenScreen assay (GSA). In this assay, a reporter system in the yeast cells employs the DNA damage inducible prom...

BACKGROUND Different parts of Podocarpus henkelii have been used in many cultures around the world to treat ailments such as cholera, stomach diseases, rheumatism, cancer, canine distemper in dogs and gall sickness in cattle. The aim of this study was to evaluate the biological activity and toxicity of isolated compounds from Podocarpus henkelii after an earlier study indicated a promising acti...