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RAD PROT PT 2 Radiobiology and Cells WEEK 7 – 9 RT 244 (2006 – 2010)

RAD PROT PT 2 Radiobiology and Cells WEEK 7 – 9 RT 244 (2006 – 2010). RADIOBIOLOGY Radiation Protection & Biology CD SERIES 2 - 6. RADIATION PROTECTION AND EFFECTS. CD # 2 - CELLULAR RADIATION + STAT CH 4, 5 & 6. What type of Radiation Response is this?

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RAD PROT PT 2 Radiobiology and Cells WEEK 7 – 9 RT 244 (2006 – 2010)

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  1. RAD PROTPT 2Radiobiologyand CellsWEEK 7 – 9 RT 244 (2006 – 2010) RADIOBIOLOGYRadiation Protection & BiologyCD SERIES 2 - 6 RADIATION PROTECTION AND EFFECTS

  2. CD # 2 - CELLULAR RADIATION+ STAT CH 4, 5 & 6 What type of Radiation Response is this? How much rads does it take to see this?

  3. # 2 – CELLS MADE OF PROTOPLASM • RESPONSIBLE FOR THE METABOLISM OF THE CELLS • COMPOSED MOSTLY OF WATER • (80-85%) CD 2 - # 2

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

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

  6. XXXXX

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

  8. 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.

  9. 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)

  10. 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

  11. CD 2 - # 6

  12. CD2 # 21 21- CELL DAMAGE FROM RADIATION

  13. 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

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

  15. 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

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

  17. CD2 - #28 CELL DIVISION

  18. 1 2 4 8 16 32 64 128 256 512 1024 “never ending” CELL DIVISION FROM

  19. # 32 MEIOSIS – THE SPERM AND OVUM • 46 Chromosone reduced to • 23 for Females + • 23 for Males • to unite during reproduction

  20. 34 * CELLULAR EFFECTS OF RADIATION Vulnerability of all cells to Radiation CD 2 - # 34

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

  22. CD 2 - # 37 MASTER MOLECULE

  23. CD 2 # 37

  24. CELL DEATH - MASTER MOLECULE USUALLY DNA HIT

  25. CD 2 # 35

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

  27. 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

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

  29. 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

  30. 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)

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

  32. OER Oxygen Enhancement Ratio • OXYGEN IN CELL INCREASES LET • PT IN HYPERBARIC TREATMENT AND ON OXYGEN • LET IS AFFECTED BY OXYGEN

  33. CD 2 - # 38

  34. # 39 – RADIAITON DAMAGE TO DNA EFFECTS OF RADIATION DAMAGE DNA – LOSS OF CONTROL OVER CELL FUNCTION PRODUCTION OF DAUGHTER CELLS WITH GREATER LOSS OF CELL FUNCTION • Inablity to divide or reproduce • OTHER CELL COMPONENTS • LOSS OF IMPORTANT CELL FUNCTIONS • PRODUCTION OF TOXIC WASTES • CELL DEATH

  35. #40 RADIATION DAMAGE TO CELL’S NUCLEUS • INSTANT DEATH • REPRODUCTIVE DEATH • APOPTOSIS- PROGRAMMED CELL DEATH • MITOTIC, OR GENETIC DEATH OR DELAY • INTERFERENCE OF FUNCTION • CHROMOSOME BREAKAGE

  36. INSTANT DEATH – 1000 GY (100,000 RAD) • REPRODUCTIVE DEATH - 1 – 10 GY ( 100 – 1000) • APOPTOSIS – CELL DEATH BEFORE DIVISION • MITOTIC/ GENETIC DEATH – CELL’S DEATH AFTER DIVISION • OR DELAY – JUST BEFORE CELL DIVISION • INTERFERENCE OF FUNCTION • MAY BE REPARIED BY ENZYMES • OR PERMANENTYLY DAMAGE CELL FUNCTION • CHROMOSOME BREAKAGE – CAUSE GENETIC MUTATIONS IN FUTURE GENERATIONS

  37. Stages of Radiation Damage

  38. # 43 – IONIZING RADIATION CAN • PERMANENTLY DAMAGE CELL FUNCTIONS • TEMPORARILY INTERFERE WITH CELL FUNCTIONS • CAUSE CHROMSOME BREAKAGE • CAUSE GENEITC DAMAGE IN FUTURE GENERATIONS

  39. ALL CELLS ARE NOT EQUAL# 44 – CELL RADIOSENSITIVITY SOME CELLS ARE MORE: • SENSITIVE TO DAMAGE • MORE EAISLY REPAIRED • MORE QUICKLY REPLACED • All of these factors affect the radiosensitivity of the cell

  40. The Law of Bergonie & Tribondeaux CD 2 #45 • Cells that are most sensitive to radiation • Young – immature cells • Stem Cells • Highly dividing (mitotic) cells

  41. Radiosensitivy Is Related To Cell Function, Cell Maturity And Cell Division Rate • Conversely – Cells Least Sensitive Are: • Cells That Reproduce Slowly • Short Mitotic Cycle • Least Degree Of Specialization • Most Mature

  42. CELLS MOST SENSITIVE CELLS THAT REPRODUCE THE MOST – SPEND THE MOST TIME IN THEIR REPRODUCTIVE STATE • WHITE BLOOD CELLS – LYMPHOCYTES • RED BLOOD CELLS – ERYTHOROCYTES • BASAL CELLS OF THE SKIN • INTESTINAL CELLS • DEVELOPING NERVE CELLS OF EMBRYO • IMMATURE REPRODUCTIVE CELLS • EPITHELIAL CELLS THAT LINE BLOOD • LYMPHATIC VESSELLS (80% BODY)

  43. LYMPHOCYTE PG.103 • SUBGROUP OF WBC • ONLY LIVE FOR 24 HOURS • ARE MANUFACTURED IN BONE MARROW • MOST RADIOSENSITIVE BLOOD CELL • 25 RADS CAN DEPRESS # OF CELLS • LESS ABILITY TO FIGHT INFECTIONS

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