The prevalence of chromosomal aberrations in Argentine air crew members.

The authors analyzed the effects of chronic exposure of Argentine air crew members to low doses of ionizing radiations. Genetic damage induced by either low doses or low rates of ionizing radiation was higher than expected. Seventy-one heparinized blood samples were obtained from technical ground workers (group A; n = 10), pilots of domestic flights (group B; n = 14), pilots of transequatorial flights (group C; n = 17;), pilots of transpolar flights (group D; n = 17) and retired pilots (group E; n = 10) The frequency of dicentric chromosomes was higher in groups B and C compared with groups D and E.

Evaluation of radioadaptive response induced in CHO-K1 cells in a non-traditional model.

Purpose: The present study was designed to evaluate the effects of sequential exposures to low doses of gamma-radiation that induce a radioadaptive response to a later high-dose of radiation in CHO-K1 cells.

Materials And Methods: Cells were cultured in four dilution cycles and grown to confluency. Radiation treatment was performed once per cycle with 0.

Assessment of genotoxic damage in lymphocytes of hospital workers exposed to ionizing radiation in Argentina.

The authors aimed to assess genotoxic damage in the lymphocytes of workers chronically exposed to ionizing radiation. The studied population included 15 exposed donors of the radiology unit of a public hospital in La Plata, Argentina. The control group included 15 nonexposed employers from administrative areas that the authors matched by age, sex, and smoking habits.

Evaluation of p53 codon 72 polymorphism in adenocarcinomas of the colon and rectum in La Plata, Argentina.

Aim: To evaluate the potential association between p53 codon 72 polymorphism and sporadic colorectal adenocarcinoma development,and human papillomavirus (HPV) infection.

Methods: One-hundred and nine controls and 53 patients with colon cancer from the city of La Plata, Argentina were analyzed. p53 codon 72 genotypes and HPV infection were identified using allele-specific polymerase chain reaction and nested polymerase chain reaction, respectively.

Genotoxic effects of benzo[a]pyrene and dibenzo[a,l]pyrene in a human lung cell line.

Several studies have shown that polycyclic aromatic hydrocarbons (PAHs) produce genotoxic effects in assays performed in vivo and in vitro. This study was undertaken to investigate the ability of benzo[a]pyrene (BP) and dibenzo[a,l]pyrene (DBP) to induce DNA damage in a human lung fibroblast cell line (MRC-5), using sister-chromatid exchanges test (SCEs), the comet assay, and evaluating point mutations in codon 12 of the K-ras protooncogene by polymerase chain reaction-single-strand conformation polymorphisms (PCR-SSCPs) and restriction fragment length polymorphisms (RFLP)-enriched PCR methods. Sister-chromatid exchanges frequencies were significantly increased in cells exposed to benzo[a]pyrene and dibenzo[a,l]pyrene in relation to controls (p < .

Herpes simplex virus and human papillomavirus infection in cervical disease in Argentine women.

The aim of the present study was to determine that prevalence of herpes simplex virus (HSV) type 1 and 2 in cervical samples from Argentine women and to assess the role of HSV-2 in cervical cancer. A sample of 79 normal and 200 neoplastic cervical tissues (35 invasive cervical carcinomas, 75 high-grade squamous intraepithelial lesions, 79 low-grade squamous intraepithelial lesions and 11 abnormal squamous cells of undermined significance) was analyzed for herpes simplex and human papillomavirus DNA using the polymerase chain reaction method. Viral genotyping was performed by single strand conformation polymorphisms and restriction fragment length polymorphisms.

Induction of DNA strand breaks, DNA-protein crosslinks and sister chromatid exchanges by arsenite in a human lung cell line.

Based on in vitro studies, several modes of action for arsenic have been suggested, although the mechanisms responsible for arsenic carcinogenesis have not been well established. In our previous study a dose-dependent increment in DNA migration was detected at low doses of sodium arsenite, but at higher dose levels a reduction in the migration was observed, suggesting the induction of DNA adducts. In order to confirm this hypothesis we performed the experiments considering other parameters and modifications of the standard alkaline comet assay.

DNA-protein cross-links and sister chromatid exchanges induced by dimethylarsinic acid in human fibroblasts cells.

Biotransformation of inorganic arsenic to form both methylarsinic acid (MA) and dimethylarsinic acid (DMA) has traditionally been considered as a mechanism to facilitate the detoxification and excretion of arsenic. However, the methylation of inorganic arsenic as a detoxification mechanism has been questioned due to recent studies revealing an important role of organic arsenic in the induction of genetic damage. In a previous report a reduction of DNA migration after treatment of cells with DMA was described.

Chlamydia trachomatis and Human papillomavirus infections in cervical disease in Argentine women.

Objectives: To examine the prevalence of Human papillomavirus and Chlamydia trachomatis DNA in cervical samples among women with normal and abnormal cervical cytology from La Plata, Argentina.

Methods: Two hundred and seventy-nine women (200 with cervical neoplasia or ICC and 79 women with normal cytology) provided cervical samples for the detection of HPV and C. trachomatis DNA by PCR-based assays.

A comparative investigation of DNA strand breaks, sister chromatid exchanges and K-ras gene mutations induced by cadmium salts in cultured human cells.

Cadmium (Cd) is a toxic heavy metal of continuing occupational and environmental concern with a wide variety of adverse effects. Several studies have shown that cadmium produces DNA strand breaks, DNA-protein cross-links, oxidative DNA damage, chromosomal aberrations, dysregulation of gene expression resulting in enhanced proliferation, depressed apoptosis and/or altered DNA repair. This study was undertaken to investigate the ability of cadmium chloride (CdCl(2)) and cadmium sulphate (CdSO(4)) to induce point mutations in codon 12 of the K-ras protooncogene assessed by polymerase chain reaction-single strand conformation polymorphisms (PCR-SSCP) and RFLP-enriched PCR methods.

The c-myc activation in cervical carcinomas and HPV 16 infections.

Despite the prominent role for Human Papillomavirus (HPV) infection in the development of genital cancer, other genetic or environmental co-factors have also been involved. Studies of c-myc activation in cervical carcinomas have reported that gene over-expression (mainly gene amplification) are common in cervical squamous cell carcinomas and may correlate with the biologic behavior of the neoplasm. Using PCR based technology, DNAs from 79 normal cervical samples and 225 abnormal cervical tissue scrapes were analyzed for HPV detection and typing and for c-myc gene amplification.

The hyaluronic acid receptor (CD44) is expressed in bovine oocytes and early stage embryos.

Hyaluronic acid (HA) is a high molecular weight polysaccharide found in the extracellular matrix of most animal tissues, that exerts a profound influence on cell behavior. HA is one of the most abundant glycosaminoglycans (GAGs) in the uterine, oviductal and follicular fluids in mouse, pig, human and cattle. CD44, the principal cell membrane receptor for HA, is expressed from the 1- to 8-cell stage in human embryos, during post-implantation mouse embryogenesis and on the surface of differentiated embryonic stem cells.