Re-evaluation of CBMN test reference values of persons continuously occupationally exposed to low doses of ionizing radiation in Serbia.

When established, cytokinesis-block micronucleus (CBMN) test reference values should be periodically evaluated according to the recommendations of reference documents. The biodosimetry cytogenetic laboratory of the Serbian Institute of Occupational Health established the CBMN test reference range for people occupationally exposed to ionizing radiation in 2016. Since then, new occupationally exposed persons have been subjected to micronucleus testing, resulting in the need for re-evaluation of existing CBMN test values. The examined population comprised 608 occupationally exposed subjects - 201 from the previous laboratory database and 407 newly examined. Comparison of groups based on gender, age and cigarette consumption did not show significant differences, although certain CBMN values differed significantly between the old and new groups. Duration of occupational exposure, gender, age and smoking habit influenced micronuclei frequency in all three analyzed groups, while no relation was found between type of work and micronucleus test parameters. Since the mean values of all tested parameters in the new group of examinees are within previously established reference ranges, existing values can be used in further research.

Construction of dose response calibration curves for dicentrics and micronuclei for X radiation in a Serbian population.

Biological dosimetry using chromosome damage biomarkers is a valuable dose assessment method in cases of radiation overexposure with or without physical dosimetry data. In order to estimate dose by biodosimetry, any biological dosimetry service have to have its own dose response calibration curve. This paper reveals the results obtained after irradiation of blood samples from fourteen healthy male and female volunteers in order to establish biodosimetry in Serbia and produce dose response calibration curves for dicentrics and micronuclei. Taking into account pooled data from all the donors, the resultant fitted curve for dicentrics is: Ydic=0.0009 (±0.0003)+0.0421 (±0.0042)×D+0.0602 (±0.0022)×D(2); and for micronuclei: Ymn=0.0104 (±0.0015)+0.0824 (±0.0050)×D+0.0189 (±0.0017)×D(2). Following establishment of the dose response curve, a validation experiment was carried out with four blood samples. Applied and estimated doses were in good agreement. On this basis, the results reported here give us confidence to apply both calibration curves for future biological dosimetry requirements in Serbia.

Review of retrospective dosimetry techniques for external ionising radiation exposures.

The current focus on networking and mutual assistance in the management of radiation accidents or incidents has demonstrated the importance of a joined-up approach in physical and biological dosimetry. To this end, the European Radiation Dosimetry Working Group 10 on 'Retrospective Dosimetry' has been set up by individuals from a wide range of disciplines across Europe. Here, established and emerging dosimetry methods are reviewed, which can be used immediately and retrospectively following external ionising radiation exposure. Endpoints and assays include dicentrics, translocations, premature chromosome condensation, micronuclei, somatic mutations, gene expression, electron paramagnetic resonance, thermoluminescence, optically stimulated luminescence, neutron activation, haematology, protein biomarkers and analytical dose reconstruction. Individual characteristics of these techniques, their limitations and potential for further development are reviewed, and their usefulness in specific exposure scenarios is discussed. Whilst no single technique fulfils the criteria of an ideal dosemeter, an integrated approach using multiple techniques tailored to the exposure scenario can cover most requirements.

Arabidopsis histone deacetylase 6: a green link to RNA silencing.

Epigenetic reprogramming is at the base of cancer initiation and progression. Generally, genome-wide reduction in cytosine methylation contrasts with the hypermethylation of control regions of functionally well-established tumor suppressor genes and many other genes whose role in cancer biology is not yet clear. While insight into mechanisms that induce aberrant cytosine methylation in cancer cells is just beginning to emerge, the initiating signals for analogous promoter methylation in plants are well documented. In Arabidopsis, the silencing of promoters requires components of the RNA interference machinery and promoter double-stranded RNA (dsRNA) to induce a repressive chromatin state that is characterized by cytosine methylation and histone deacetylation catalysed by the RPD3-type histone deacetylase AtHDA6. Similar mechanisms have been shown to occur in fission yeast and mammals. This review focuses on the connections between cytosine methylation, dsRNA and AtHDA6-controlled histone deacetylation during promoter silencing in Arabidopsis and discusses potential mechanistic similarities of these silencing events in cancer and plant cells.

[Significance of serum creatinine levels in respiratory insufficiency conditions]. / Znacenje nivoa kreatininemije u stanjima respiratorne insuficijencije.

Analyses of creatinema in the cases of global respiratory failure was performed in this paper. The patients with global respiratory failure treated in General Hospital in TeSanj have been followed. For all patients laboratory analyses have been performed on the admimtion and in the time of clinical status improvement, including creatinin level, K, Na, Hb, Htc, and blood gas analyses with mesurement of pO2 pCO2 pH, BE, saturation of the blood with oxgen, BE and HCO3-. Creatinine level have been considered in coleration of body mass index, and general nutritional status. The dinamic source of creatinine level in the blood have been followed, in relation of parameters of respiratory status. The statistical significance in relation of creatinine level with the respiratory status was registrated. With the improvement of respiratory status and laboratory analyses related to respiratory status, decrease of creatinin level was registrated. Because of that the therapy given to the patients with respiratory failure could influence on potassium level, the relation of creatinnemia and potassium level in the blood wasn't considered. The high creatinin level couldn't be explained with the initial renal failure, but as the sign of metbolic adaptation to hypoxemic and hypoxyc situation on the body. The registration of high creatinine level in the situations of global respiratory failure could be the guidelines for the choice of the antibiotics for these patients, mostly for potentially nephrotoxic antibiotics, like aminoglicosides, and theirs combinations. The decision and evaluation of benefit and toxicity of antibiotics for these situations could be easier.