1 / 66

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?

arva
Download Presentation

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

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  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

More Related