S(N)1-type alkylating agents, like N-methyl-N-nitrosourea (MNU) and N-ethyl-N-nitrosourea (ENU), are potent mutagens. Exposure to alkylating agents gives rise to O(6)-alkylguanine, a modified base that is recognized by DNA mismatch repair (MMR) proteins but is not repairable, resulting in replication fork stalling and cell death. We used a somatic mutation detection assay to study the in vivo e...

Persistent hepadnavirus infection leads to oxidative stress and DNA damage through increased production of toxic oxygen radicals. In addition, hepadnaviral DNA integrations into chromosomal DNA can promote the process of hepatocarcinogenesis (M. Feitelson, Clin. Microbiol. Rev. 5:275-301, 1992). While previous studies have identified preferred integration sites in hepadnaviral genomes and sugge...

The importance of chromosomal aberrations as a proximate cause of bone marrow toxicity is discussed. Since chemicals that can cause nondisjunction are rare, numerical aberrations (aneuploidy, polyploidy) are not ordinarily important. Many structural aberrations, however, can lead directly to cell death and so are proximate causes of toxicity when they occur. The micronucleus test which utilizes...

Cyclophosphamide is one of most commonly used in malignant lymphomas. The antioxidants such as Vit C inhibits the toxicity of mutagens/carcinogens in animals and Humans. The protective effects of ascorbic acid (AA) on cyclophosmide (CP) induced cytogenetic damage was evaluated suing analysis of chromosomal aberrations in human lymphocytes in vitro. When cultures were treated with various doses ...

background: cyclophosphamide (cyp) is used to treat a wide range of human tumors. however, the mutagenic effect of cyp is still the primary limitation for wider applications to treat a variety of human malignancies. it has been reported that cyp entrapped in liposomes reduces non-specific toxicity and enhances anticancer effects in animal systems. methods: in the present experiment, mice were i...

Pesticides constitute a heterogeneous category of chemicals specifically designed for the control of pests, weeds or plant diseases. Pesticides have been considered potential chemical mutagens: experimental data revealed that various agrochemical ingredients possess mutagenic properties inducing mutations, chromosomal alterations or DNA damage. Biological monitoring provides a useful tool to es...

Various studies have suggested the existence of different pathways of tumor progression in colorectal cancer that associate with specific molecular, chromosomal, and clinicopathological features. We hypothesize that a comprehensive analysis of cumulated genomic damage in colorectal cancers would aid the characterization of different tumor progression pathways and identify the factors determinin...

There is increasing evidence that in eukaryotic cells, DNA undergoes continuous damage, repair and resynthesis. A homeostatic equilibrium exists in which extensive DNA damage is counterbalanced by multiple pathways for DNA repair. In normal cells, most DNA damage is repaired without error. However, in tumor cells this equilibrium may be skewed, resulting in the accumulation of multiple mutation...

OBJECTIVE To evaluate the ameliorative role of grapefruit juice on the cytogenetic and testicular damage induced by the antiarrythmic drug amiodarone in albino rats. METHODS Animals were divided into four groups. Group I was considered as control. Group II was given grapefruit juice at a dose level of 27 mL/kg body weight. Group III was orally administered amiodarone (18 mg/kg body weight) da...

Recent studies suggest increased cancer risk in patients with type 2 diabetes mellitus (T2DM) compared with healthy individuals. The present study aims to assess whether T2DM is associated with increased genome instability and whether a healthy diet with natural foods can improve genome stability in peripheral blood lymphocytes (PBLs). Seventy-six diabetic and 21 non-diabetic individuals were r...