ABSTRACT
In recent years, members of the Coronaviridae family have caused outbreaks of respiratory diseases (MERS, SARS, and COVID-19). At the same time, the potential of radiation-induced inactivation of this group of viruses have been little studied, although radiation technologies can be widely used both in the processing of personal protective equipment and in the sterilization of vaccines. In the present work, the effect of 10 MeV electron beams and 7.6 MeV bremsstrahlung on the coronavirus infection pathogen (transmissible gastroenteritis virus) has been studied in vitro. In the given experimental conditions, irradiation with photons turned out to be more effective. The virus-containing suspension frozen at -86°C was the most resistant to radiation: the dose required for complete inactivation of the virus in this case was from 15 kGy, while for the liquid suspension and lyophilized form the sterilizing dose was from 10 kGy. At lower radiation doses for all samples during passaging in cell culture, residual infectious activity of the virus was observed. These differences in the efficiency of inactivation of liquid and frozen virus-containing samples indicate a significant contribution of the direct effect of radiation.
ABSTRACT
Radiation therapy with heavy particles including neutrons, an otherwise therapeutically perspective because of its high tissue penetration and efficient tumor damage, is currently limited by the lack of adequate equipment. An NG-24 generator (140 kg, 42 × 110 cm, ~1011 particles/s, > 14 MeV) has been designed and engineered to replace the huge and environmentally harmful neutron reactors, cyclotrons, and accelerators with a compact, portable, safe, and potent source of high-energy neutrons. We demonstrate that the neutron beam produced by NG-24 causes a significant antiproliferative effect on human tumor cell lines regardless of the status of the anti-apoptotic p53 protein. Phosphorylation of histone 2A and increased amounts of p21, cyclin D, and phospho-p53 were detectable in HCT116 colon carcinoma cells (wild-type p53) irradiated with 4 Gy several days post-treatment, accompanied by G2/M phase arrest. These treatments dramatically reduced the ability of single cells to form colonies. In the HCT116p53KO subline (p53 -/-), the G2/M arrest was independent of the aforementioned mechanisms. Hence, the NG-24 generator is a source of a powerful, therapeutically relevant neutron flux that triggers a p53-independent antiproliferative response in tumor cells.
ABSTRACT
The paper describes the role of radionuclide technologies among the nuclear-physical methods used in medicine. The condition and prospects of the development of nuclear technology with use of radionuclides in medicine, and in particular, the method of brachytherapy are analyzed. The analysis of the current state of applying radionuclide facilities in medicine is provided.
Subject(s)
Brachytherapy , Medicine , Radioisotopes , Radiosurgery , Humans , Positron-Emission TomographyABSTRACT
Manifestations of regional hypertensive neurocirculatory dystonia in periodontal tissues of young persons living in strong continent climate of Transbaikalia region were determined by two methods: laser doppler flowmetry (LDE) and rheoparodontography. Masticatory loads revealed the restriction of functional reserves and absence of adequate reaction of periodontal vessels. These loads increase vasoconstriction and don't remove the transformational risk of functional changes to organic ones. In prevention and treatment of described disturbances of Transbaikalia region in periodontal tissues the leading role must be given to medicament therapy.
Subject(s)
Climate , Mastication/physiology , Periodontium/blood supply , Adolescent , Adult , Capillaries/physiology , Humans , Laser-Doppler Flowmetry , Plethysmography, Impedance , Regional Blood Flow , Siberia , Vascular Resistance/physiologyABSTRACT
Bibliographic and original experimental data related to the problem of the role of central nervous system in controlling hibernation are analyzed. It is shown that limbic structures (septal zone, hippocamp, hypothalamus) are of great significance. Taking into consideration the key role of medial septum as a generator of hippocampal theta-rhythm, the elevated excitability of septal neurones in brain slices obtained from hibernating animals and other experimental data, a conclusion is drawn about the role of medial septal nuclear complex as the forebrain "watch point" in hibernation. The significance of thyrotropin-releasing hormone in controlling the waking/hibernation cycle is discussed.
