RAD PROT PT 2 Radiobiology and Cells WEEK 7 – 9 RT 244 2006

1. RAD PROTPT 2Radiobiologyand CellsWEEK 7 – 9RT 2442006

2. RADIOBIOLOGYRadiation Protection & BiologyCD SERIES 2 - 6 RADIATION PROTECTION AND EFFECTS

3. CD # 2CELLULAR RADIATION+ STAT CH 4, 5 & 6

4. RESPONSIBLE FOR THE METABOLISM OF THE CELLS COMPOSED MOSTLY OF WATER (80-85%) # 2 – CELLS MADE OF PROTOPLASM

5. CD 2 - # 2

6. A quick review of interactions Stat Ch 1 & 2

11. PHOTOELECTRIC ABSORBTION IS WHAT GIVES US THE CONTRAST ON THE FILM

12. XXXXX

17. DNA IN THE NUCLEUS • CONTAINS THE GENETIC MATERIAL • CONTROLS CELL DIVISION + MULITPLICATION • AND BIOCHEMICAL REACTIONS THAT OCCUR IN THE LIVING CELL

18. 6 – DNA IS THE ESSENTIAL INGREDIENT IN THE 46 HUMAN CHROMOSOMES • DNA CARRIES THE GENETIC CODE FOR CELL REPRODUCTION AND CELL ACTIVITY • DNA EXISTS MOSTLY IN THE NUCLEUS OF THE CELL • RADIATION INDUCED CHROMOSOME DAMAGE IS ONE OF THE MOST IMPORTANT REASONS FOR LIMITING RADIATION EXPOSURE.

19. Repair Enzymes • SOME CHROMOSOME DAMAGE CAN BE REVERSED BY REPAIR ENZYMES - ( 5 RADS) • IF REPAIR IS NOT POSSIBLE – CELL DEATH OCCURS • TOO MANY CELLS DIE – TISSUE OR ORGAN DAMAGE OCCURS • (Rad Therapy – therapeutic ratio (p 66)

20. WHEN DNA DAMAGE RESULTS IN ABNORMAL METABOLIC ACTIVITY – • THERE CAN BE UNCONTROLLED CELL GROWTH – • THIS IS WHAT OCCURS IN RADIATION INDUCED MALIGNANT DISEASE. • WHEN DNA DAMAGE OCCURS THE EFFECTS MAY NOT SHOW UP UNTIL FUTURE GENERATIONS

22. CD 2 - # 6

23. 21- CELL DAMAGE FROM RADIATION

24. CD2 # 21

25. 23 – Cell DivisionHow and why radiation effects the human body • HITS NUCLEUS – DAMAGE TO DNA • HITS WATER – RADIOLYSIS OCCURS – • CAN SET OFF A REACTION RESULTING IN CELL DEATH • A BREAK IN THE CELL MEMBRANE CAN EXPOSE THE CELL TO OUTSIDE ELEMENTS

26. CD2 - # 24

27. MITOSIS SOMATIC CELLS EVERY CELL THAT IS NOT GENETIC MEIOSIS REPRODUCTIVE CELLS GERM CELLS sperm + eggs CELL DIVISION (#24)Multiplication process where cells divide

28. 4 PHASES OF MITOSIS • INTERPHASE – THE PROCESS BEFORE MITOSIS BEGINS • PROPHASE – nucleus swells – DNA takes structure • METAPHASE • MOST SENSITIVE STAGE FOR DAMAGE • Chromosomes line up in the center • ANAPHASE • TELOPHASE –cells split to daughter cells

29. METAPHASE • DURING THIS PHASE • CELL DIVISION CAN BE STOPPED AND EVALUATED • CHROMOSOME DAMAGE CAUSED BY RADIATION DAMAGE CAN BE SEEN

30. CD2 - #28 CELL DIVISION

32. CD 2 # 33

33. 1 2 4 8 16 32 64 128 256 512 1024 “never ending” CELL DIVISION FROM

34. # 32 MEIOSIS – THE SPERM AND OVUM • 46 Chromosone reduced to • 23 for Females + • 23 for Males • to unite during reproduction

36. 34 * CELLULAR EFFECTS OF RADIATION Vulnerability of all cells to Radiation CD 2 - # 34

37. CD 2 - # 36 36 CELL THEORY – TARGET THEORY – MASTER MOLECULE (DNA Molecule) If this is destroyed the cell can die (Direct or Indirect hit)

39. CD 2 - # 37 MASTER MOLECULE

40. CD 2 # 37

41. CELL DEATH - MASTER MOLECULE USUALLY DNA HIT

42. CD 2 # 35

43. Radiolysispoison water theory • H 2 O molecules - • Ejection of electron = free radical • H2 0 2 = hydrogen peroxide

46. LET linear energy transfer • The amount of energy that may be deposited in tissue as radiation passes • Factor in assessing potential damage to organs/tissues from exposure to ionizing radiation • ↑ ENERGY = ↓ LET - passes through

47. Damage from LET • High – LET (alpha particles – radon) • Internal contamination • implanted, ingested or inhaled • Potiental for irreparable damge

48. RBE ↑ WITH O2Relative Biologic Effectiveness • Describes the capabilities of radiation with differing LET’s to produce a particular biologic reaction • Weighting factor • (EqD) equivalent dose

49. PARTICULATE (HIGH LET) ALPHA BETA FAST NEUTRONS More destructive ELECTROMAGNETIC (LOW LET) XRAY GAMMA (damaged caused by indirect action = free radicals – can be repaired) TYPES OF RADIATON(ALL CAUSE IONIZATION)

50. Quality (Weighting) Factor • How dangerous the type of radiation is • Alpha + fast neutrons = 20 • X-ray, Beta, Gamma = 1 • (why “fluffy” died!)