Hepatic Gene Expression Changes in Rats Internally Exposed to Radioactive 56MnO2 Particles at Low Doses.

We have studied the biological effects of the internal exposure to radioactive manganese-56 dioxide (56MnO2), the major radioisotope dust found in soil after atomic bomb explosions. Our previous study of blood chemistry indicated a possible adverse effect of 56MnO2 on the liver. In the present study, we further examined the effects on the liver by determining changes in hepatic gene expressions. Male Wistar rats were exposed to 56MnO2 particles (three groups with the whole-body doses of 41, 90, and 100 mGy), stable MnO2 particles, or external 60Co γ-rays (2 Gy), and were examined together with the non-treated control group on postexposure day 3 and day 61. No histopathological changes were observed in the liver. The mRNA expression of a p53-related gene, the cyclin-dependent kinase inhibitor 1A, increased in 56MnO2 as well as in γ-ray irradiated groups on postexposure day 3 and day 61. The expression of a stress-responsive gene, nuclear factor κB, was also increased by 56MnO2 and γ-rays on postexposure day 3. However, the expression of cytokine genes (interleukin-6 or chemokine ligand 2) or fibrosis-related TGF-ß/Smad genes (Tgfb1, Smad3, or Smad4) was not altered by the exposure. Our data demonstrated that the internal exposure to 56MnO2 particles at less than 0.1 Gy significantly affected the short-term gene expressions in the liver in a similar manner with 2 Gy of external γ-irradiation. These changes may be adaptive responses because no changes occurred in cytokine or TGF-ß/Smad gene expressions.

An Exploration of the Labor, Financial, and Economic Factors Related to Suicide in the Republic of Kazakhstan.

The Republic of Kazakhstan has one of the world's highest suicide rates. A detailed study of the risk factors for suicide in that country is therefore important. We investigated country-wide statistics related to labor, financial, and economic factors and whether any of these factors contribute to the risk of suicide in Kazakhstan. Using the 20 year period from 2000 to 2019, we examined the annual suicide rates overall (all citizens) and for males and females in Kazakhstan, annual unemployment rates, annual rates of increase in the country's consumer price index, annual total exports, and annual total imports. We then calculated the correlations between the suicide rates and these four items. We also performed a multiple regression analysis of the relationship between the suicide rate and those four items. The results of these analyses indicated that the unemployment rate was the correlation coefficient most highly correlated with the suicide rate; unemployment was significantly related to suicide and should be targeted as a risk factor in suicide prevention interventions in Kazakhstan. With this in mind, organizations, government agencies, and professionals in relevant fields need to devise and implement suicide prevention measures.