Cytogenetic examination

Nehez M, Boros P, Ferke A, et al. 1988. Cytogenetic examination of people working with agrochemicals in the southern region of Hungary. Regul Toxicol Pharmacol 8 37-44. 

Table 3.6. Results of cytogenetic examination of adolescents from agricultural zones with differing intensity of pesticide use [97]... 

Complete cyto and histopathological examination Electron microscopy Cytogenetic examinations... 

Cytogenetic examination was made of peripheral blood lymphocytes from women whose work involved exposure to chloroprene latex (Fomenko et al., 1973). Twenty women, aged 19-23 years and employed for 1-4 years, were exposed to 3-7 mg/m v eight women, aged 19-50 years and employed for 1-20 years were exposed to 1-4 mg/m3. These two groups were compared with a control group of 181 compiled... 

Katosova, L.D. Pavlenko, G.I. (1985) Cytogenetic examination of the workers of chemical industry (Abstract). Mutat. Res., 197, 300... 

Koudela, K. Spazier, K. (1981) Results of cytogenetic examination of persons working in an environment of increased concentration of dimethylformamide vapours in the atmosphere. Prak. Lek., 33, 121-123 (in Czech)... 

Cytogenetic examination of bone marrow cells showed no increase in aberrations in maternal and neonatal rats following maternal oral exposure to a DeBDE and NoBDE mixture. In vitro assays found that DeBDE did not induce gene mutations in several bacterial tests (Ames assays) or in mammalian cells. DeBDE also did not induce chromosomal aberrations in Chinese hamster ovary cells. However, exposure to the congeners 2,2, 4,4 -tetra-BDE, 3,4-diBDE, and 2-monoBDE caused increased recombinogenic activity at the HGPRT locus in several cell lines. 

Mabille V, Roels H, Jacquet P, et al. 1984. Cytogenetic examination of leukocytes of workers exposed to mercury vapor. Int Arch Occup Environ Health 53 257-260. 

The major Impetus to the development of methods for the prenatal detection of genetic disorders derives. In historical terms, from the roughly simultaneous development of three major techniques (11-14). One was the technique, and the willingness to use It, for obtaining samples of amnlotlc fluid early In gestation. The second was the development of techniques for the culture of human cells in vitro, and the third was the development of better techniques for cytogenetic analysis. As will be described below, with the availability of these three techniques It became possible first to work out methods for the examination of fetal chromosomes, and then, by extension, to devise ways of determining other characteristics of the fetus. 

Cytogenetic Analysis and Sex Determination. Since amnlotlc fluid cells are fetal In origin, they have the chromosome complement of the fetus Itself Therefore, the chromosomes of the fetus can be examined by karyotyping the cultured amnlotlc fluid cells There are two principal reasons for examining fetal chromosomes One, the numerically less frequent reason. 

Although chromosome abnormalities are still commonly visualized by examining metaphase chromosomes under a microscope, several powerful new techniques combine cytogenetics with modern molecular methods. Two of the most important are described here. 

Cytogenetic studies have been conducted using bone marrow cells of rats following inhalation exposure to 1,4-dichlorobenzene (Anderson and Richardson 1976). Three series of exposures were carried out (1) one exposure at 299 or 682 ppm for 2 hours (2) exposures at 75 or 500 ppm, 5 hours per day for 5 days and (3) exposures to 75 or 500 ppm, 5 hours per day, 5 days per week for 3 months. Bone marrow cells from both femurs were examined for chromosome or chromatid gaps, chromatid breaks, fragments, or other complex abnormalities. In all three experiments, exposure to 1,4-dichlorobenzene failed to induce any effects indicative of chromosomal damage. Other genotoxicity studies are discussed in Section 2.5. 

An increased rate of chromosomal abnormalities has been reported for adult-onset schizophrenia (Karayiorgou and Gogos, 1997 Bassett et al., 2000). Cytogenetic abnormalities have been examined in the NIMH COS cohort. Five of our initial 54 patients had cytogenetic abnormalities (a girl with Turner s syndrome, a boy with a balanced translocation of chromosomes 1... 

This test is usually much more sensitive, but considerably more expensive and slower, than the dominant-lethal test,131 and it deals with a clearly defined type of mutation that is transmitted to and scored in viable offspring. Males are exposed to the test substance and mated to untreated females. Male progeny (usually derived only from post-sperroatogonial treatments) are tested for translocations by the fertility test or the cytogenetic test. In the fertility test, males are tested, usually with a sequential procedure, to determine fertility rates.137 Animals suspected of having a translocation (because of decreased fertility) are then subjected to cytologic examination. 

All Ft males are examined in the cytogenetic translocation test.7 Most translocation carriers have characteristic multivalent associations in diakinesis-metaphase I spermatocytes, which produce many unbalanced gametes because of blockage in spermatogenesis. 

In 2005, a study appeared in Cancer Letters that would have evoked widespread media coverage if it had been about an illegal drug, rather than about a pharmaceutical company product (El-Zein, 2005). Researchers from the University of Texas examined 12 children treated with therapeutic effects of Ritalin to determine whether this central nervous system stimulant produces cytogenetic abnormalities in pediatric patients at therapeutic doses. Using peripheral blood lymphocytes taken from the children, they found a 2.4-fold increase in chromosome aberrations and similar defects. They concluded, These findings warrant further investigations of the possible health effects of methylphenidate in humans, especially in view of the well-documented relationship between elevated frequencies of chromosome aberrations and increased cancer risk. ... 

Bone marrow biopsy and aspirate send for morphologic examination, cytochemical staining, immunophenotyping, and cytogenetic (chromosome) analysis. 

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