The micronucleus assay in exfoliated human cells: a mini-review of papers from the CIS.

The critical analysis of the data concerning micronucleus assay in exfoliated epithelial cells presented by the investigators from the CIS is carried out. Twenty two articles are evaluated, and shortcomings of some of them are discussed. Presented results are compared whenever possible with literature data. The aim of the mini-review is a criticism of shortcomings of the papersforfurther improvement of the presentation of the data on micronucleus assay which will give the possibility to compare the results with the data presented by foreign investigators.

Possible role of the micronucleus assay in diagnostics and secondary prevention of cervix cancer: a minireview.

Recent literature data are presented concerning micronuclei (MN) frequency in exfoliated cells of cervix cancer patients. These data strongly support a positive correlation between the MN level and malignization (changes from premalignant stage to cancer). It is suggested that the evaluation of frequency of MN in exfoliated cervical cells may be an additional criterion for establishing cervical cancer risk and the study of MN in cervix smears will increase the sensitivity and specificity of cytology which could impact in diagnostics and secondary prevention of cervical cancer.

Micronuclei level in exfoliated buccal mucosa cells of patients with benign and malignant tumors of female reproductive organs and breast.

Micronucleus (MN) levels in exfoliated buccal mucosa cells of primary breast, cervix and corpus uteri cancer patients, and patients with benign tumors of uterus (myoma) and breast (fibroadenoma) were studied. Significantly increased number of MN in cells of cancer patients was observed compared to both healthy persons and patients with benign tumors. In patients with benign tumors no increase in MN quantity was observed. The evaluation of MN number in buccal mucosa cells shows genomic instability caused by malignant tumor in somatic cells of humans.

Modification of clastogenesis and carcinogenesis in rats and mice by means of anthrax live vaccine.

Possible micronuclei (MN) inducing activity of anthrax live vaccine (ALV; produced in Armenia and used for immunization of animals) was studied on rats and mice. It has been shown that ALV did not induce MN in rodents' bone marrow erythrocytes. For the first time it has been shown that immunization of rats and mice with ALV led to decrease of micronuclei number induced by cyclophosphamide and 7,12-dimethylbenz(a)anthracene in bone marrow cells. Immunized rats were also resistant to carcinogenic action of 7,12-dimethylbenz(a)anthracene. Immunization reduced significantly the number of rats with tumor and mean tumor weight, and increase the mean latency period of tumor development. It would be of interest to carry out further investigations of the anticlastogenic/anticarcinogenic effects of ALV used for immunization of humans, if only because anthrax was used and may be used again in future as a biological weapon.

The incidence of various types of childhood leukemia in Armenia (1991-2002).

PURPOSE: To analyse the incidence of various types of childhood leukemia in Armenia for the period 1991-2002. MATERIALS AND METHODS: The results presented in this communication were based on the official data obtained from the Center of Haematology, Yerevan, Armenia, where all patients with leukemia are diagnosed and treated. The types of leukemia were classified according to ICD-10; C91.0 - acute lymphoid leukemia (ALL), C91.1 - acute myeloid leukemia (AML) and C92.0 - chronic myeloid leukemia (CML). RESULTS: There was a substantial prevalence of ALL among all cases (85.6%, mean value for 12 years). ALL varied from 74.4% in 1998 to 95.4% in 1992. The mean percentage of AML and CML were 12.3 and 2.1, respectively. The proportion of ALL/AML + CML in Armenian children varied from 20.5 in 1992 to 3.2 in 1998 with a mean value of 7.2. There was not any regularity in various leukemia types in children during the observed period of time. CONCLUSION: No regularity in the incidence of various childhood leukemia types was revealed during 1991-2002. Like in most countries, a substantial prevalence of ALL incidence was observed.

Inhibition of carcinogenic and clastogenic effects of N-nitrosomorpholine in rats immunized with tularemia vaccine.

The aim of the present work was to study whether immunization of rats with tularemia live vaccine (TLV) can influence carcinogenic and mutagenic action of N-nitrosomorpholine (NNM). The experiments were performed with male albino random-bred rats. The first group of rats was immunized with TLV 15 days before the start of experiment. These animals and the second group (positive control) were treated with NNM orally, (total dose was about 250 mg/rat). Rats including solvent (negative) control group were killed 12 months after the start of NNM treatment to study the carcinogenic effect. Experiments to study the influence of TLV on mutagenesis were performed with three groups of rats: the first (on 15th day after immunization with TLV) and the second group were injected intraperitoneally with NNM 100 mg/kg b.w. on 2 consecutive days, third group received only distilled water. The results of long-term experiment have shown that tumor incidence (both malignant and benign) in rats of positive control group was 74.2%. Immunized rats had significantly decreased incidence of tumors compared with the previous group--36.1%. Micronuclei level in bone marrow cells of non-immunized rats was statistically significantly higher than that in immunized rats. The inhibition of carcinogenic and clastogenic effects of NNM in rats immunized with TLV are probably due to a decrease in cytochrome P-450 activity. We suggest that immunization of rats with TLV can protect them against the cacinogenic and clastogenic actions of some chemicals.

Possible genotoxic activity of extracts of Bryonia alba roots on human lymphocytes and transformed cells.

Bryonia alba roots (BAR) are widely used as an adaptogenic and restorative drug with immunomodulatory and stress-protective properties that increase the non-specific resistance of an organism toward harmful stimuli. Potential genotoxic activity of aqueous and methanol extracts of BAR was studied on human normal (lymphocytes) and transformed (HeLa and Caco-2) cells using single cell gel electrophoresis (the comet assay). The results obtained did not show any evidence of genotoxic effects of BAR.

Chromosome aberrations in lymphocytes of persons exposed to an earthquake in Armenia.

OBJECTIVE: This study attempted to determine the level of chromosome aberrations in lymphocytes of victims of the 1988 earthquake in Armenia. METHODS: Chromosome aberrations were measured in blood samples taken from 41 victims of the earthquake that hit Armenia in 1988 and in samples of 47 reference blood donors. The victims suffered from severe psychoemotional stress but were otherwise healthy. All the samples were taken 2 to 3 weeks after the earthquake. All the subjects were lifetime nonsmokers. The cells were scored blind as to the exposure status. RESULTS: The subjects exposed to the earthquake had a higher proportion of cells with chromosome aberrations [3.1 (SD 2.1)%] than the referents [1.7 (SD 1.3)%, P-value for the difference 0.0009]. The difference persisted when the values were adjusted for age and gender [relative risk (RR) 1.9, 95% confidence interval (95% CI) 1.4-2.5]. The difference was present for double breaks (RR 4.1, 95% CI 2.6-6.4), but not for single breaks (RR 1.1, 95% CI 0.8-1.7). The exposed subjects also had a lower percentage of cells with 46 chromosomes (P=0.03) than the referents. CONCLUSIONS: This study suggests an increase in chromosome aberrations in the lymphocytes of victims of a severe earthquake as compared with the levels of referents. If not due to bias or confounding, the difference may reflect the effect of either environmental exposures related to the earthquake or severe psychogenic stress. The levels of chromosome aberrations found among the earthquake victims in this study are comparable with those found in prospective studies of long-term cancer risk.