introduction: fragile x syndrome (fxs) is one of the most prevalent genetic causes of developmental disability, representing the most frequent form of inherited severe cognitive deficit. the present study was undertaken to investigate fxs and its prevalence in moderate mentally retarded people in patients. materials and methods: nineteen people with moderate mental retardation (mr) who were cli...

Mammography, using 26-30 kV X-rays, is a method routinely used to screen early stages of breast cancer, but some discussion about radiation-related risk associated with this methodology exists. For radioprotection purposes, it has been assigned a quality factor of 1 for all photon energies. However, the relative biological effectiveness (RBE) could increase as photon energy decreases. Analysing...

In recent years there has been a surge in methylphenidate (Ritalin) use for treatment of attention deficit/hyperactivity disorder (ADHD) in children. However, there is a paucity of information on whether this drug poses any potential health risks, such as mutagenicity or carcinogenicity, for humans. To address this issue, we investigated whether this central nervous system stimulant produces cy...

a cytogenetic study was performed on 11 tetraploid cotton cultivars (gossypium hirsutum l.)including the oltan cultivar and its crossing progenies. the chromosome pairing and chiasma frequency, aswell as meiotic abnormalities were compared among the genotypes studied. heterozygote translocations withalternate orientation were observed between some of the chromosomes of the a genome and those of...

A brief description of chromosome aberrations and sister chromatid exchange (SCE) as cytogenetic endpoints for evaluation of DNA damaging agents is presented. Problems associated with the use of cytogenetic assays as population monitors of radiation and chemical exposures are discussed. Adequate cell sample size requirements and accurate assessment of cummulative exposure effects with increasin...

Cytogenetic effects of ciprofloxacin (500 to 2,000 mg daily) and ofloxacin (200 mg daily) were studied in lymphocytes from 31 patients treated for 1 to 10 weeks. Blood samples for cytogenetic analysis were taken before the start of treatment from all patients, after 1 week from 25 patients, and after 2, 4, 6, and 10 weeks from six patients. No chromosome-damaging effect could be demonstrated in...

Polymorphisms of xenobiotic-metabolizing enzymes, responsible for individual differences in metabolic activation and detoxification reactions, may profoundly modulate the effects of chemical carcinogens. In the case of genotoxic carcinogens, differences in biological effects due to genetic polymorphisms can be evaluated by cytogenetic methods such as the analysis of chromosomal aberrations (CAs...