Objective(s): Precision-cut tissue slices are considered an organotypic 3D model widely used in biomedical research. The comet assay is an important screening test for early genotoxicity risk assessment that is mainly applied on in vitro models.  The aim of the present study was to provide a 3D organ system for determination of genotoxicity using a modified method of the comet assay since the s...

Background & Aims: Induced pluripotent stem cells (iPSCs) have the capability to undergo unlimited selfrenewal and differentiation into all cell types in the body. These cells are artificially derived from a nonpluripotent cell, typically human dermal fibroblasts (HDFs). The study of cytogenetic stability of these cells, in order to use iPS cells and apply studies in therapeutic applications, i...

Accurate chromosome segregation requires the spindle assembly checkpoint to be active at the onset of mitosis, before being silenced following chromosome alignment. p31(comet) is a checkpoint antagonist in that its inhibition delays mitotic exit, whereas its overexpression overrides the checkpoint. How exactly p31(comet) antagonises the checkpoint is unclear. A prevalent model is that p31(comet...

The human mitotic arrest-deficient 2 (Mad2) binding protein p31(comet) participates in the spindle checkpoint and coordinates cell cycle events in mitosis although its function in meiosis remains unknown in all organisms. Here, we reveal P31(comet) as a synaptonemal complex (SC) protein in rice (Oryza sativa L.). In p31(comet), homologous pairing and synapsis are eliminated, leading to the homo...

Although the Comet assay, a procedure for quantitating DNA damage in mammalian cells, is considered sensitive, it has never been ascertained that its sensitivity is higher than the sensitivity of other genotoxicity assays in mammalian cells. To determine whether the power of the Comet assay to detect a low level of genotoxic potential is superior to those of other genotoxicity assays in mammali...

We investigated the mechanisms of DNA exit during single-cell gel electrophoresis (the comet assay) by measuring the kinetics of the comet tail formation. In the neutral comet assay, the rate of DNA exit was found to be dependent on the topological state of DNA, which was influenced by either ethidium bromide or a low radiation dose. The results clearly show that the comet tail is formed by ext...

The infrared emission of various comets can be matched within the framework that all comets are made of aggregated interstellar dust[ This is demonstrated by comparing results on Halley "a periodic comet#\ Borrelly "a Jupiter family short period comet#\ HaleÐ Bopp "a long period comet#\ and extra!solar comets in the b Pictoris disk[ Attempts have been made to generalize the chemical composition...

Comet-FISH technique is an extension of commonly used comet assay. Its purpose is to determine whether primary DNA damage which comet assay detects occurred within a sequence of interest that is visualized by hybridization of fluorescent probe. Presence of the signal in comet tail indicates impaired structural integrity of sequence. Our modifications to the original comet-FISH technique describ...

The purpose of this study was to evaluate the frequency of echogenic foci with comet-tail artifact in histologically proven thyroid nodules, and to determine the types of echogenic foci with comet-tail artifact that are associated with malignancy. We retrospectively analyzed the sonographic findings of echogenic foci with comet-tail artifact, present in thyroid nodules in 63 patients who underw...

The secular evolution of comet nucleus rotation states subject to outgassing torques is studied. The dynamical model assumes that the nucleus inertia ellipsoid is axially symmetric. The outgassing torques acting on the surface are modeled using standard cometary activity formulae. The general rotational equations of motion are derived and separately averaged over the fast rotational dynamics te...