When DNA topoisomerase II (topo II) activity is inhibited with a non-DNA-damaging topo II inhibitor (ICRF-193), mammalian cells become checkpoint arrested in G2-phase. In this study, we analyzed chromosome structure in cells that bypassed this checkpoint. We observed a novel type of chromosome aberration, which we call omega-figures. These are entangled chromosome regions that indicate the persistence of catenations between nonhomologous sequences. The number of omega-figures per cell increased sharply as cells evaded the transient block imposed by the topo II-dependent checkpoint, and the presence of caffeine (a checkpoint-evading agent) potentiated this increase. Thus, the removal of nonreplicative catenations, a process that promotes chromosome individualization in G2, may be monitored by the topo II-dependent checkpoint in mammals.
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http://dx.doi.org/10.1007/s004120000065 | DOI Listing |
Zhongguo Dang Dai Er Ke Za Zhi
January 2025
Department of Children's Hematology and Oncology, First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China.
Objectives: To investigate the clinical characteristics and prognosis of acute erythroleukemia (AEL) in children.
Methods: A retrospective analysis was conducted on the clinical data, treatment, and prognosis of 8 children with AEL treated at the First Affiliated Hospital of Zhengzhou University from January 2013 to December 2023.
Results: Among the 7 patients with complete bone marrow morphological analysis, 4 exhibited trilineage dysplasia, with a 100% incidence of erythroid dysplasia (7/7), a 71% incidence of myeloid dysplasia (5/7), and a 57% incidence of megakaryocytic dysplasia (4/7).
J Appl Toxicol
January 2025
Department of Biosciences, Institute of Health and Society, Federal University of São Paulo, UNIFESP, Santos, São Paulo, Brazil.
The present systematic review aims to put together human population studies that include some relationship between genetic polymorphisms and genotoxicity as well as to evaluate the quality of the published studies induced by cigarette smoke exposure in vivo. The present systematic review was built according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Different genotoxicity assays were used by different authors, although the major goal was the genotoxicity assessment by means of micronucleus, comet, sister chromatid exchange, and chromosomal aberration assays.
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January 2025
Centre for Reproductive Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China.
It has been debated whether endometriosis (EMS) adversely affects oocyte quality, potentially leading to a higher incidence of genetically unbalanced embryos or other egg factors that affect the developmental potential. In this study, we explored the effects of endometriosis on risk of chromosomally aberrant in miscarried products of conception (POC) after assisted reproductive treatment (ART), including fresh and frozen cycles. Miscarried POCs were collected from EMS patients (N = 102) and non-EMS patients (N = 441).
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January 2025
Sexually Transmitted and Bloodborne Infections Surveillance and Molecular Epidemiology, Sexually Transmitted and Bloodborne Infections Division at the JC Wilt Infectious Diseases Research Centre, National Microbiology Laboratories, Public Health Agency of Canada, Winnipeg, MB, R3E 3L5, Canada.
Human Immunodeficiency Virus Type 1 (HIV) set-point viral load is a strong predictor of disease progression and transmission risk. A recent genome-wide association study in individuals of African ancestries identified a region on chromosome 1 significantly associated with decreased HIV set-point viral load. Knockout of the closest gene, CHD1L, enhanced HIV replication in vitro in myeloid cells.
View Article and Find Full Text PDFNeurol Neuroimmunol Neuroinflamm
March 2025
MeLis Institute, SynatAc Team, Inserm U1314/ UMR CNRS5284, France.
Background And Objectives: Breast cancers (BCs) of patients with paraneoplastic neurologic syndromes and anti-Yo antibodies (Yo-PNS) overexpress human epidermal growth factor receptor 2 (HER2) and display genetic alterations and overexpression of the Yo-onconeural antigens. They are infiltrated by an unusual proportion of B cells. We investigated whether these features were also observed in patients with PNS and anti-Ri antibodies (Ri-PNS).
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