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Abstract Objective We aim to describe an experimental model for studying femoral fractures in rats after exposure to ionizing radiation, demonstrating a way to apply a substance for analysis, the method for patterning fracture and irradiation, and how to evaluate its effectiveness based on radiographic studies. Methods We used 24 rats divided into 2 groups of 12 animals each. The STUDY group was exposed to ionizing radiation and treated with saline solution, and the CONTROL group was not exposed to radiation and was treated with saline solution. All animals were subjected to standardized fracture of the right femur that was fixed with intramedullary wire. The efficiency of the bone union was assessed by radiographic exam. Results Fracture healing was more efficient in bones not exposed to ionizing radiation (p = 0.012). All fractures met the criteria of being simple, diaphyseal, transverse or short oblique. Conclusion The experimental model presented is an efficient alternative for the study of fractures in irradiated bones in rats.

The iodine-131 (I-131) content in the thyroid of staff members working with this radionuclides has been measured with about 500 employees in about 25 hospital’s departments of nuclear medicine performing therapy and diagnosis of thyroid disease in Poland. The measurements were performed with portable detection unit for in situ measurements of radioiodine. This is consist with scintillation detector sodium iodine activated by thallium (NaI(Tl)) – battery-powered and portable tube base Multichannel Analyzer Canberra UniSPEC. Based on direct measurements of the iodine content, the effective dose equivalent for workers due to inhalation of I-131 was estimated. All individuals actively working with iodine show measurable amounts of this isotopes in their thyroids. The average measured activity in the thyroid of the nuclear medicine staff was found to be equal at average 550 Bq within the range 70 Bq–2.5 kBq. There is no apparent correlation between the measured I-131 levels and risk categories. Nevertheless the technical and nuclear medicine staff show higher I-131 thyroid level comparing to hospital services staff. Calculated maximum committed effective dose for particular exposed person is

Over the last decades, along with progress and development of using ionizing radiation, including the fields of power engineering or nuclear weapons, it was possible to observe and describe negative effects of the radiation on human body. The phenomenon referred to as acute radiation syndrome describes the effects of radiation on living cells, depending on exposure time and absorbed dose, which affects the functioning of entire organism after the exposure. The following work describes how ionizing radiation causes changes at the cellular and tissue level, both directly and indirectly, taking into account the variables affecting final effects of exposure. Consecutive phases of acute radiation syndrome were distinguished, and the focus was also on individual groups of disorders resulting from exposure, which may overlap and coexist, i.e. hematopoietic syndrome, gastrointestinal syndrome and neurovascular syndrome, as well as developing multi-organ failure in some of the cases, leading to the patient's death. Exposure to ionizing radiation can result in diversified, variably intensified and spread over time symptoms from many organ systems. Depending on the characteristics of the exposure, its effects will differ, and thus the prognosis for the patient.

Aim: To analyze the influence of the hydrogen sulfide donor NaHS on the cardiac control in rats during of low doses of ionizing radiation and characterize the predictors of imbalance in autonomic nervous system activities. Methods: Adult male rats were treated once with NaHS 7,4 mg/kg, i.p. or vehicle (saline) without and with exposure total body radiation (TBR). Heart rate variability (HRV) was recorded in rats after 30 min with NaHS pre-treatment, 24 h of TBR exposure and NaHS and TBR combination. Results: HRV analysis revealed that low doses of radiation causes cardiac autonomic dysfunction. TBR rats had signs of activation sympathetic nervous system, while NaHS-treated rats had shown mobilization of all parts of regulatory systems with predominant activation of the parasympathetic nervous system (PSNS). Taking together, this results indicate, that NaHS involves in cardiac control and decreases sensitivity to low doses of radiation. Conclusions: The gaseous messenger H2S under conditions of radiation modulates of adaptive processes, acting as a regulator for imbalance of autonomic nervous system and may serve as a novel cardioprotective agent for ANS imbalance. Key words: Hydrogen sulfide (H2S), low doses radiation (LDR), autonomic nervous system (ANS), cardiovascular system, heart rate variability (HRV), hydrogen sulfide donor (NaHS).