Transcript Laboratory of Radiobiology
Laboratory of Radiation Biology, JINR Dr. Oleg Belov
Laboratory of Radiation Biology
What is the RADIOBIOLOGY?
Radiobiology (or radiation biology) is the complex fundamental science studying various aspects of influence ionizing and not ionizing radiations on biological objects
The fundamental problem of radiobiology:
the opening of general regularities of the organism's biological response to the influence of ionizing radiation
The basic radiobiological paradox Enormous discrepancy between the insignificant amount of the absorbed energy and the extreme expressiveness of biological object’s response up to a lethal outcome
The irradiation in a dose of 10 Gy kills mammals of all kinds
10 Gy = + 10 -3 0 С
Connection of radiobiology with other disciplines
Genetics Biology Biophysics Cytology Radiobiology Medicine Biochemistry Physiology Nuclear Physics
Phasotron
Protons with energy up to 660 MeV
U-400 M
Heavy ions 7 Li 2+ 86 Kr 9+ Energy up to 50 MeV/amu
Synchrophasotron
Protons, heavy ions Energy up to 10 GeV/amu
Nuclotron
Heavy ions
What radiobiological problems can be solved at use of accelerated heavy particles?
A. Heavy ions is a powerful tool for solving problems in radiation genetics
Tracks of heavy ions in nuclear emulsion
Si Ca Ti Fe Z =14 20 22 26
Mammalian cell
Z = 70
Action of heavy ions can lead to the DNA damages
Z = 70
The dose distribution of radiation in matter
1 unit of the dose 1 unit of the dose X-rays Fe ion
А
DNA double strand breaks in human cells after X-ray (А) and heavy ion irradiation (B)
B
Single DNA damage Sparse ionizing radiation (X-rays) Single strand break Base damage Повреждени е основания Повреждение сахара
Clustered DNA damage Heavy ions irradiation Base damages
Double strand break of DNA
Sugar damage Base damages
Yield of clustered DNA damage as a function of Liner Energy Transfer ( LET )
1E-10 e 1 H 4 He 12 C 1E-11 1E-12 0,1 SSB + damage of opposite strand SSB + damage of opposite strand Base damage + sugar damage Base damage + sugar damage DSB DSB 1 10 L E T , keV/ m 100 1000
“Comet assay” for detection of DNA lesions
Dose, Gy D = 0 Gy D = 5 Gy D =10 Gy D = 20 Gy D = 40 Gy D = 60 Gy
Formation of unstable chromosomal aberration in human cells after heavy ion irradiation
Unstable chromosomal aberration
Dose, Gy Block of cell division
Formation of stable chromosomal aberrations in human cells after heavy ion irradiation
Chromosome № 1
Stable chromosomal aberration
Successful of cell division
Dose, Gy
B. Theoretical studies in Radiobiology
1. Theoretical study of induced mutagenesis
2. Simulation of particle track structure
Model of DNA Model of particle track
3. Molecular dynamics simulation of proteins structure
MDGRAPE-2 Board and Chip
4 MDGRAPE-2 chips PCI card 16 Mbyte SSRAM Broadcast write extension Prion 5 million transistors 0.25μm, 2.5 V from IBM corp.
15 Watt at 100 MHz clock frequency 15 Gflops equivalent RNA
C. Accelerated heavy ions as a tool for modeling of biological action of space radiation
Problem of manned interplanetary space missions
1 2
What will be the radiation environment during space flight?
… and at Mars?
The G alactic C osmic R ays flux
The integral flux of GCR particles of carbon and iron groups equals to
10 5 part/cm 2 per year
Particle flux density interplanetary space z 160 per day per cm 2 20
The energy spectrum of GCR and Nuclotron
Consequences of Galactic heavy ion action
Induction of cancer; Formation of gene and structural mutations; Violation of visual functions:
lesions of retina;
cataract induction;
Central nervous system (CNS) violation
Worgul et al., 2006
In Vitro
Neurotoxic Effects of 56 Fe Ions on Retinal Explants
90000 70000 0
0 cGy 5 cGy 10 cGy
50000 0
50 cGy
30000 20000 0 50 100 Dose, cGy 150 200 250 apoptosis
100 cGy 200 cGy Vazquez, 2006
Cosmic ray hit frequencies in CNS critical areas A A B B CNS in General
2 or 13% cells will be hit at least one Fe particle
8 or 46% would be hit by at least one particle with Z
15
Every nucleus will be traversed by a proton once every 3 days and a alpha particle once every 30 days.
p p p Fe Mixed Field Multi-hit FE ION TRACKS VISUALIZED BY MARKERS OF DNA DSBs (γH2AX) 0 cGy 50 cGy
e TRACK DIRECTION 100 cGy 200 cGy
Control
Cognitive tests (Morris Water Maze)
56 Fe ions, 1 GeV/amu 1.5 Gy
1 month after irradiation
http://lrb.jinr.ru
Laboratory of Radiation Biology, JINR
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