Chromosomal aberrations and sickness rates in Chernobyl clean-up workers in the years following the accident.

The aim of this investigation was to reveal a possible correlation between chromosomal aberrations and the health status of Chernobyl clean-up workers who suffered from a low dose of ionizing radiation. Unstable chromosomal aberrations in peripheral blood lymphocytes were investigated in 491 Chernobyl clean-up workers. Information about lifestyle factors (all persons) and medical history (212 persons) was collected.

Angiotensin-converting enzyme genotype and encephalopathy in Chernobyl cleanup workers.

Background And Purpose: To identify, using a genetic model, a key role for the renin-angiotensin system (RAS) in the development of dyscirculatory encephalopathy (DE) in Chernobyl cleanup workers (CCW). The insertion/deletion polymorphism of the angiotensin-converting enzyme (ACE) gene denotes a substantial individual variation in RAS activity with the D-allele being associated with higher ACE activity.

Methods: Ninety-three male, Caucasian CCW were recruited from those under regular review at the All-Russia Centre of Emergency and Radiation Medicine, St.

Cytogenetic study of professional rescue rangers of Russian Ministry of Emergencies.

Cytogenetic studies in rescue rangers of the Russian Ministry of Emergencies has shown that this category of specialists are exposed to genotoxic factors during their professional activity. The level of induction of cytogenetic injuries of rescue team members depended on labor conditions, genotype (glutathione-S-transferase M1 and T1 xenobiotic detoxication genes), and tobacco smoking.

[Chromosomal aberrations and parameters of oxidative stress in Chernobyl clean-up workers in a remote period after ionizing radiation].

This investigation was performed to test a supposition about the influence of disturbances in antioxidative system on cytogenetical parameters in Chernobyl' clean-up workers. It was shown that some cytogenetical parameters straightly correlated with the parameters of oxidative stress, while other cytogenetical parameters show just reverse correlations. Apparently, these relationships are not of cause-and-effect type, but they reflect a complex processes occurring in humans for a long period after radiation exposure.

Chromosome alterations in cleanup workers sampled years after the Chernobyl accident.

Cytogenetic analysis performed 4-13 years after the Chernobyl accident showed an elevated frequency of acentrics, chromatid exchanges, dicentrics and rings in Chernobyl cleanup workers compared to the control group. Cytogenetic data were analyzed according to the information on exposure to radiation (the year when the cleanup workers worked at the Chernobyl station, doses rates, time elapsed since exposure to radiation, and cytogenetic examination) and some lifestyle factors. The data obtained suggested that some types of chromosome aberrations could be influenced by the action of different environmental factors or lifestyle factors.

[Some complexities in evaluating radiation-induced mutagenic effects in man].

Chromosomal aberrations in somatic cells (circulating lymphocytes) have been investigated in a remote period in different groups of people who suffered from radiation accidents. The chromosomal radiation markers were found even decades after irradiation. The question about the necessity of registration of non-classical mutagenic effects after human irradiation is raised.

Persistence of dicentrics in Chernobyl clean-up workers who suffered from low doses of radiation.

Blood samples from 243 clean-up workers who undertook duties at Chernobyl in 1986 were examined in order to study temporal changes of chromosomal aberrations over long periods (6-12 yr) following irradiation. From an analysis of the elapsed time between irradiation and cytogenetic examination, it was found that the frequency of dicentrics and rings did not decrease during the 6 yr period of observation.

Cytogenetic investigation of occupationally irradiated persons a long time after exposure.

Chromosomal analyses were performed in blood lymphocytes of 33 persons previously occupationally exposed to ionizing radiation. An increased frequency of chromosome aberrations, mainly dicentrics, a long time, up to 47 years after exposure, suggests that it is possible to use the method of unstable aberration analysis for assessment of previous radiation exposure. The enhanced yield of dicentrics was observed in persons who may have received irradiations above permitted limits.

Cytogenetic investigation of thallium-poisoned people: pilot study.

Thirteen blood samples of thallium-poisoned people were cytogenetically investigated. The thallium concentration in blood varied from 25 to 2700 microg/L. The mean frequency of chromosomal aberrations in the poisoned group significantly exceeded our control level (7.

Increased level of chromosomal aberrations in lymphocytes of Chernobyl liquidators 6-10 years after the accident.

Chromosomal aberrations (CA) were used to investigate the level of cytogenetical damage in peripheral blood lymphocytes from the liquidators in a remote period (6-10 years) after the Chernobyl accident. There was a significantly higher frequency of chromosomal radiation markers (dicentrics and rings) in the peripheral lymphocytes of the liquidators than in the control subjects. No differences between these groups were demonstrated by the micronucleus (MN) test.

[Chromosomal anomalies of human gametes and intrauterine selection. Research on female gametes].

The results of cytogenetical analysis of human oocytes are summarized. The chromosomal disorders in human gametes and in spontaneous abortions are comparatively analyzed.

[Chromosome abnormalities of human gametes and intrauterine selection. Male gametes].

Man appears to be unique among mammals with respect to very high level of reproductive wastage. It seems reasonable to suppose that many early losses attribute to cytogenetical abnormalities. However, this stage of pregnancy is difficult to be studied.

[Nature of the estrous cycle, incidence of anovulation, chromosome gametopathies and fetal death in female rats with 2,4-dichlorophenoxyacetic acid (2,4-D) before pregnancy].

The effect of herbicide--2,4-D, injected before pregnancy begins, on the main parameters of the reproductive function of the female rats has demonstrated that chronic administration in doses 1 mg/kg and 12 mg/kg per day for 2 months results in certain disturbances in the estrus cycle, manifesting as prolongation of the diestrus phase and in changes of estrus and meta-estrus++ duration, as well as in an essential increase in rates of anovulatory cycles. Single administration of the preparation during the preovulatory period (50 mg/kg) produces certain disturbances in the chromosomal complex, manifesting as appearance of numerical chromosomal aberrations. When the administration is acute (10 mg/kg and 50 mg/kg) an essential increase of the embryonal death takes place, in the first case--at the expense of ++pre-implantational, and in the second--both at the expense of pre- and ++post-implantational death.

[Chromosomal disorders in the oocytes of rats after stress exposure in the preovulatory period].

Female rats at the stage of proestrus have been subjected to a stress effect--immobilization for an hour. Oocytes were cytogenetically analyzed and embryonal mortality was determined. It is shown that this stress effect at the end of the fist meiotic division of the oocytes increased the rate of aneuploid gametes and the level of embryonal mortality.

[Chromosome aberrations and dominant lethals in rat oocytes during acute and chronic alcoholic intoxication].

The influence of a single dose and of long-term alcohol administration on cytogenetic processes in the oocytes of Wistar white rats was studied. It is shown that a single dose of alcohol in preovulatory period when the oocytes are in the stage of diakinesismeiosis metaphase I significantly increases the rate of aneuploid gametes and dominant lethality. Analogous effect follows after long-term alcohol administration.

[Variants of chromosome compactization and the estimation of the capacity of mammalian oocytes for further development].

The morphology of chromatin in spontaneously ovulated rat's oocytes was investigated. The degree of chromatin condensation was shown to vary widely: along with the typical cytological picture of metaphase II, both highly condensed (clamped) and decondensed ("not typical") forms of chromosomes were observed. A direct relation was discovered between the prevalence of the not typical morphological forms of oocyte chromosomes and the level of embryonal death.

[Structural and functional indices of disturbances of oocyte maturation in androgenized rats after induction of ovulation with pregnant mare's serum and luliberin].

The ultrastructure of oocytes from large follicles and the meiotic maturation rate of preovulatory oocytes of intact and androgenized rats were studied. The oocytes of defeminized animals were characterized by the lack of organelles and by changes of their structure. According to the rate of meiosis they were divided into two groups.

[Interrelation of the hormonal indices and the cytologic characteristics of the germ cells].

The analysis of the maturation of follicular oocytes as well as of the state of gametes after induction of ovulation with PMSG or with GnRH in intact and androgenized rats revealed the dependence of the heterogeneity extent (in morphologic and chromosomal damages) of population of germ cells maturing in vivo and in vitro upon the character of gonadotropin regulation disturbances of folliculogenesis. Stable disorder of reproductive function (androgenization) is followed by a significant increase in number of abnormal gametes under its hormonal correction.

[Frequency of sister chromatid exchanges in human lymphocytes at different times of day].

Analysis of the frequency of sister chromatid exchanges in the human blood taken from normal female donors was made at 9 a. m. and 9 p.

[Distribution of the frequency of sister chromatid exchange among Leningrad inhabitants].

Peculiarities of frequency variations in sister chromatid exchanges (SCE) were studied in a group of healthy Leningrad citizens who are not engaged in health-risk industries. No relations were found between the SCE frequency and sex, age and smoking habit (10 cigarettes per day as much). The statistical processing of the data obtained was made taking into account the errors in individual measurements of the SCE frequency.