The effect of low-level exposure to formaldehyde on oral, nasal, and lymphoycte biological markers was studied prospectively in a group of 29 mortician students who were about to take a course in embalming. During the 85-day study period, the subjects performed an average of 6.9 embalmings and had average cumulative formaldehyde exposures of 14.8 ppm-h, with an average air concentration of 1.4 ...

Rodent (9L and 9L-2) and human (SF-126 and SF-188) brain tumor cells were treated with methylating, ethylating, and chloroethylating nitrosoureas. 9L-2 and SF-188 cells were 10-fold and 5.4-fold more resistant to the cytotoxic effects of 1-(2-chloroethyl)-1-nitrosourea (CNU) than were 9L and SF-126 cells. SF-188 cells were 2.5- to 3-fold more resistant to N-methyl-N-nitrosourea (MNU) and strept...

Formaldehyde (FA) is known to be genotoxic and mutagenic in proliferating mammalian cells in vitro. The present study was performed to further characterize its genotoxic potential in the V79 Chinese hamster cell line. The induction of DNA strand breaks and DNA-protein cross-links (DPXs) was measured by the comet assay in relationship to the induction of sister chromatid exchanges (SCEs) and mic...

Aneuploidy in fetal chromosomes is one of the causes of pregnancy loss and of congenital birth defects. It is known that the frequency of oocyte aneuploidy increases with the human maternal age. Recent data have highlighted the contribution of cohesin complexes in the correct segregation of meiotic chromosomes. In mammalian oocytes, cohesion is established during the fetal stages and meiosis-sp...

For cells on the path to carcinogenesis, the key to unlimited growth potential lies in overcoming the steady loss of telomeric sequence commonly referred to as the 'end-replication problem' that occurs with each cell division. Most human tumors have reactivated telomerase, a specialized reverse transcriptase that directs RNA-templated addition of telomeric repeats on to chromosomal termini. How...

The influence of diethylstilbestrol (DES) on the SCE frequency was studied in various cell systems (V79, HTC, DON, WI-38, human lymphocytes) differing in their ability to metabolize the two promutagens benzo(a)pyrene and cyclophosphamide as well as after incubation with exogenous metabolic systems (S9 mix and peroxidase/H2O2) and in vivo on cells from the bone marrow of the Chinese hamster. DES...

Members of the rDNA multigene family within a species do not evolve independently, rather, they evolve together in a concerted fashion. Between species, however, each multigene family does evolve independently indicating that mechanisms exist which will amplify and fix new mutations both within populations and within species. In order to evaluate the possible mechanisms by which mutation, ampli...

Bloom syndrome is a disorder of profound and early cancer predisposition in which cells become hypermutable, exhibit high frequency of sister chromatid exchanges, and show increased micronuclei. BLM, the gene mutated in Bloom syndrome, has been cloned previously, and the BLM protein is a member of the RecQ family of DNA helicases. Many lines of evidence suggest that BLM is involved either direc...

The effect of cis-diamminedichloroplatinum(II) (cPt) on sister chromatid exchange (SCE) induction was determined in 13 human primary tumor cell cultures. Primary cultures were derived from surgical specimens of solid tumors composed of a variety of histologies. Three to 16 days after biopsy, depending on the growth rate, cultures were treated with graded concentrations of cPt for 1 h and the SC...

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...