propranolol (pl), a non-selective beta-blocker, is a cardiovascular drug widely used to treat hypertension. the present study was concerned with assessing the cytogenetic effects of this drug on chinese hamster ovary (cho) cell line. mtt assay was then carried out to determine the cytotoxicity index (ic50) of the drug. the ic50 value of pl was 0.43±0.02 mm. to investigate the clastogenic effect...

Propranolol (PL), a non-selective beta-blocker, is a cardiovascular drug widely used to treat hypertension. The present study was concerned with assessing the cytogenetic effects of this drug on Chinese hamster ovary (CHO) cell line. MTT assay was then carried out to determine the cytotoxicity index (IC50) of the drug. The IC50 value of PL was 0.43±0.02 mM. To investigate the clastogenic effect...

Failure to repair DNA damage or defective sister chromatid cohesion, a process essential for correct chromosome segregation, can be causative of chromosomal instability (CIN), which is a hallmark of many types of cancers. We investigated how frequent this occurs in head and neck squamous cell carcinoma (HNSCC) and whether specific mechanisms or genes could be linked to these phenotypes. The gen...

Sister chromatids are often arranged as incompletely aligned entities in interphase nuclei of Arabidopsis thaliana. The STRUCTURAL MAINTENANCE OF CHROMOSOMES (SMC) 5/6 complex, together with cohesin, is involved in double-strand break (DSB) repair by sister chromatid recombination in yeasts and mammals. Here, we analyzed the function of genes in Arabidopsis. The wild-type allele of SMC5 is esse...

Ten long-term survivors of childhood acute lymphoblastic leukemia were studied to determine if cytogenetic abnormalities were present in lymphocytes following discontinuation of therapy. The study included patients diagnosed between 1969 and 1974 who had received radiation therapy and a minimum of 3 years systemic chemotherapy. At study, the patients had been off all therapy from 1.3 to 6.5 yea...

Dicentric chromosomes undergo a breakage-fusion-bridge cycle as a consequence of having two centromeres on the same chromatid attach to opposite spindle poles in mitosis. Suppression of dicentric chromosome breakage reflects loss of kinetochore function at the kinetochore-microtubule or the kinetochore-DNA interface. Using a conditionally functional dicentric chromosome in vivo, we demonstrate ...

The delayed cytotoxicity of 6-thioguanine (TG) may relate to the arrest of cells in G2 upon completion of one cell cycle after drug exposure. In Chinese hamster ovary (CHO) cells, both the unilateral chromatid damage in G2 chromosomes, determined by induction of premature condensed chromosome condensation [Maybaum and Mandel, Cancer Res. 43, 3852 (1983)], and incorporation of TG into DNA result...

NSTABILITY of the wVe ring-X chromosome of Drosophila melanogaster is I attributable to anaphase bridge formation during the cleavage mitoses where loss of the bridge from w""/+ embryos results in gynandromorphs or XO males and breakage of the bridge results in lethality (HINTON 1955). Rod-w"" chromosomes derived from unstable wuc ring chromosomes also cause lethality, but are not lost during c...