[Morphometric and cytogenetic studies of the follicular epithelium thyroid of small mammals under chronic exposure to small doses].

We have detected the genotoxic effect (increase of micronuclei) after chronic exposure to low-level ionizing radiation of the thyroid follicular epithelium of the voles living for many generations in the radioactive territory. At the same time, we also discovered the stimulating effect of chronic low-level ionizing radiation on the activity of morphogenetic processes in the thyroid parenchyma of the animals from natural populations (increased micro-follicles). These data were confirmed by the experiments; chronic irradiation of the thyroid gland of rats at the doses of 5 and 50 cGy revealed an increased induction of micronuclei and the increase in the number of small follicles.

[Morphometric analysis of follicular structure of the thyroid gland after chronic low-dose gamma-irradiation].

A quantitative study of follicle average cross-sectional diameter distribution was conducted in the thyroid gland (TG) of mouse like rodents (25 tundra voles, 24 CBA mice, 16 Wistar rats) after chronic exposure to low-level external y-radiation both in the environment and under the experimental condition (absorbed dose range 0.05-0.5 Gy).

[Cytogenetic effects in follicular epithelium of thyroid gland under prolonged exposure to gamma-radiation at low-doses].

The forming processes of micronucleated follicular thyrocytes in thyroid gland of mature Wistar rats under exposure to the prolonged low-intensity gamma-radiation with 5 and 50 cGy (dose rates: 25, 400 microGy/h; duration: 55, 80 days) were investigated. The chronic exposure to low-intensity gamma-radiation in both doses invokes the frequency of micronuclated thyrocytes three times higher in comparison with control animals. As a result of the small-sized micronuclei formation prevalence in irradiated group, the average size of micronuclei was 1.

[Morphological analysis of genetically damaged thyrocytes in nodular pathology of the thyroid gland].

The smears of isolated thyrocytes with micronuclei taken from 25 patients with nodular pathology of the thyroid gland were investigated. In all kinds of benign nodular pathology the number of micronucleated thyrocytes comes to 0.1-0.

[Isolation of cells for cytological and cytogenetic studies of the thyroid epithelium].

This paper presents a detailed description of the method for obtaining of high quality smears of thyrocytes from the fragments of rat (30 animals) and human (20 cases) thyroid gland using the method of enzymatic dissociation in 0.25% aqueous solution of collagenase (collagenase for pancreatic islet isolation type XI, collagen digestive activity 1205 units/mg, Sigma, USA) at 37 degrees C during 1; 1.5; 2; 2.