Radiobiology

1
Radiobiology Radiobiology of Accelerated Heavy
Ions
Haitham A. ShabanAssistant Researcher,
NRCTeaching Assistant, American University in
Cairo
2
RADIOBIOLOGYTHE STUDY OF THE EFFECTS OF
IONIZING RADIATION ON BIOLOGIC TISSUE
3
RADIATION EFFECT CELL THEORY

• Radiation interaction at the atomic level can
  produce molecular change, as a result, cell will
  be produced deficient.

4
ATOMIC COMPOSITION OF BODY

• 80
• 25.7
• 10.7
• 2.4
• 0.1
• O.1
• 0.8

• 02
• H2
• C
• N2
• P
• S
• TRACE ELEMENTS

5
MOLECULAR COMPOSITION OF THE BODY

• 80
• 15
• 2
• 1
• 1
• 1

• WATER
• PROTEIN
• LIPIDS
• CARBOHYDRATES
• NUCLEIC ACID
• OTHER

6
Radiation Biology
7
CELL RESPONSE TO RADIATION

• LYNPHOCYTES
• SPERMATOGONIA
• OSTEOBLASTS
• SPERMATIDS
• MUSCLE CELL
• NERVE CELL

RADIOSENSITIVE
RADIORESISTANT
8
RADIATION ENERGY TRANSFER DETERMINANTS

• LET
• RBE

9
LET-LINEAR ENERGY TRANSFER

• THE AVERAGE ENERGY DEPOSITED PER UNIT LENGTH OF
  TRACK
• keV/ µm

10
LET
a
X-RAYS
11
LET
LOW LET
HIGH LET

• GAMMA RAYS
• X-RAYS

• ALPHA PARTICLES
• IONS OF HEAVY NUCLEI
• CHARGED PARTICLES
• LOW ENERGY NEUTRONS

12
RBE RELATIVE BIOLOGIC EFFECTIVENESS

• Relative capabilities of radiation with different
  LETs to produce particular biologic response.

DOSE IN Gy FROM 250 KVP X-RAYS DOSE IN GRAY OF
TEST RADIATION
13
EFFECTS OF IONIZING RADIATION ON DNA

• BASE DAMAGE
• SINGLE STRAND BRAKE
• DOUBLE STRAND BRAKE
• CROSSLINKING

14
Clustered DNA damages
Fragment of DNA
15
BASE DAMAGE

• LOSS OR CHANGE OF A BASE ON DNA RESULTS IN
  ALTERATION OF THE BASE SEQUENCE. SEQUENCE OF THE
  BASE STORES GENETIC INFO- SERIOUS CONSEQUENCE TO
  THE CELL
• CLASSIFIED AS
• MUTATION

16
Radiation induced mutagenesis
17
SINGLE STRAND BRAKES

• RELATIVELY INCONSEQUENTIAL IN TERMS OF CELL
  KILLING. WILL BE EFFICIENTLY REPAIRED , WITH
  LITTLE, IF ANY, LONG TERM CONSEQUENCES TO THE CELL

18
DOUBLE STRAND BRAKES

• VERY DIFFICULT FOR THE CELL TO BE REPAIRED. CAN
  LEAD TO CELL KILLING. IF REPAIR DOESNT TAKE
  PLACE, THE DNA CHAINS CAN SEPARATE. SERIOUS
  CONSEQUENCE TO CELL LIFE.

19
CROSSLINKING
20
Investigation of biological effects of
accelerated heavy ions forms the new
radiobiology
21
(No Transcript)
22
(No Transcript)
23
The dose distribution of radiation in matter
1 unit of the dose
1 unit of the dose
X-rays
Fe ion
24
What radiobiological problems can be solved at
use of the accelerated heavy particles?
25
Heavy ions is a powerful tool for the solve of
fundamental problems of radiation genetics
26
The RBE problem was solved at the Flerov Lab
accelerators
DNA repair capacity of the living cells
determines the type of RBE on LET dependence
27
LABORATORY OF RADIATION BIOLOGY
Kinetics of DNA repair
PAC 08
28
3D dimension of human chromosome
Chromosome 1 of human lymphocyte nucleus in
interphase with fragment after irradiation 1 GeV
protons at synchropha-sotron. The 3 D dimensi-on
picture was obtained by using FISH technique and
confocal microscopy.
29
Induction of mutagenic DNA repair by heavy ions
luciferase
FMNH2 RCHO O2 ? FMN RCOOH H2O h?
30

• Formation of stable chromosomal aberration after
  heavy ion irradiation of human cells

Stable chromosomal aberration
Successful of cell division
31

• Formation of unstable chromosomal aberration
  after heavy ion irradiation of human cells

Block of cell division
32
Thanks to ASRT - Egypt
Acknowledgment
Thanks to ASRT - Egypt
Thanks to ASRT - Egypt
Thanks to JINR - Dubna
Thanks to JINR - Dubna
Thanks to JINR - Dubna
Thanks to Prof. ?. ?. Krasavin
Thanks to Prof. ?. ?. Krasavin
33
Thank you for the attention ?