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RADIOBIOLOGY HUMAN BIOLOGY

RADIOBIOLOGY HUMAN BIOLOGY. RADIOBIOLOGY: THE STUDY OF THE EFFECTS OF IONIZING RADIATION ON BIOLOGIC TISSUE. EARLY EFFECTS OF RADIATION ON HUMANS. HEMATOLOGIC SYNDROME G.I. SYNDROME CNS SYNDROME TISSUE DAMAGE-ERYTHEMA, DESQUAMATION HEMATOLOGIC DAMAGE CYTOGENIC DAMAGE. LATE EFFECTS.

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RADIOBIOLOGY HUMAN BIOLOGY

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  1. RADIOBIOLOGYHUMAN BIOLOGY

  2. RADIOBIOLOGY:THE STUDY OF THE EFFECTS OF IONIZING RADIATION ON BIOLOGIC TISSUE

  3. EARLY EFFECTS OF RADIATION ON HUMANS • HEMATOLOGIC SYNDROME • G.I. SYNDROME • CNS SYNDROME • TISSUE DAMAGE-ERYTHEMA, DESQUAMATION • HEMATOLOGIC DAMAGE • CYTOGENIC DAMAGE

  4. LATE EFFECTS • LEUKEMIA • BONE CANCER • BREAST CANCER • THYROID CANCER • LOCAL TISUE DAMAGE • LIFESPAN SHORTENING • GENETIC DAMAGE • CYTOGENIC DAMAGE

  5. FETAL IRRADIATION EFFECTS • PRENATAL DEATH • NEONATAL DEATH • CONGENITAL MALFORMATION • CHILDHOOD MALIGNANCY • DIMINISHED GROWTH AND DEVELOPMENT

  6. AMERICAN RADIOLOGISTS URANIUM MINERS RADIUM WATCH DIAL PAINTERS PATIENTS TREATED WITH I PATIENTS WITH ANKYLOSIS SPONDYLITIS THOROTRAST TREATMENT PATIENTS CYCLOTRON WORKERS LEUKEMIA, LIFE SHORT. LUNG CANCER BONE CANCER THYROID CANCER LEUKEMIA LIVER CANCER CATARACTS RADIATION EFFECTS IN HUMAN POPULATIONS

  7. RADIATION EFFECT CELL THEORY • RADIATION INTERACTION AT THE ATOMIC LEVEL CAN PRODUCE MOLECULAR CHANGE, AS A RESULT, CELL WILL BE PRODUCED DEFICIENT IN NORMAL GROWTH AND METABOLISM

  8. 80% 25.7% 10.7% 2.4% 0.1% O.1% 0.8% 02 H2 C N2 P S TRACE ELEMENTS ATOMIC COMPOSITION OF BODY:

  9. 80% 15% 2% 1% 1% 1% WATER PROTEIN LIPIDS CARBOHYDRATES NUCLEIC ACID OTHER MOLECULAR COMPOSITION OF THE BODY

  10. WATER –H20

  11. MACROMOLECULESVERY LARGE MOLECULES CONSISTING OF MANY ATOMS- SOMETIMES THOUSANDS

  12. MACROMOLECULES • PROTEINS • LIPIDS • CARBOHYDRATES • NUCLEIC ACIDS

  13. MITOSIS

  14. RADIATION DAMAGE ANALYZED DURING METAPHASE

  15. CELL RESPONSE TO RADIATION • LYNPHOCYTES • SPERMATOGONIA • OSTEOBLASTS • SPERMATIDS • MUSCLE CELL • NERVE CELL RADIOSENSITIVE RADIORESISTANT

  16. Radiation Biology

  17. 1906 Bergonie and Tribondeau realized that cells were most sensitive to radiation when they are: Rapidly dividing Undifferentiated LAW OF BERGOINE AND TRIBONDEAU Have a long mitotic future

  18. RADIATION ENERGY TRANSFER DETERMINANTS • LET • RBE • OER

  19. LET-LINEAR ENERGY TRANSFER • THE AVERAGE ENERGY DEPOSITED PER UNIT LENGTH OF TRACK keV/ μm

  20. LET α X-RAYS

  21. GAMMA RAYS X-RAYS ALPHA PARTICLES IONS OF HEAVY NUCLEI CHARGED PARTICLES LOW ENERGY NEUTRONS LET LOW LET HIGH LET

  22. LOW LET RADIATION DAMAGE TO BIOLOGIC TISSUE:INDIRECT ACTION

  23. HIGHT LET RADIATION DAMAGE TO BIOLOGIC TISSUE:DIRECT ACTION

  24. DIRECT & INDIRECT ACTION

  25. INDIRECT ACTION

  26. RBE –RELATIVE BIOLOGIC EFFECTIVENESS • RELATIVE CAPABILITIES OF OF RADIATION WITH DIFFERING LETs TO PRODUCE PARTICULAR BIOLOGIC RESPONSE

  27. RBE DOSE IN Gy FROM 250 KVP X-RAYS DOSE IN GRAY OF TEST RADIATION

  28. LET RBE

  29. RBE QF (QUALITY FACTOR)

  30. OER-OXYGEN ENHANCEMENT RATIO • THE RATIO OF THE RADIATION DOSE REQUIRED TO CAUSE A PARTICULAR BIOLOGIC RESPONSE OF CELLS OR ORGANISMS IN AN OXYGEN DEPRIVED ENVIRONMENT TO THE RADIATION DOSE REQUIRED TO CAUSE AN IDENTICAL RESPONSE UNDER NORMAL OXYGENATED CONDITIONS

  31. LET OER

  32. DOSE FRACTIONATION& PROTRACTIONLOWER THE EFFECT OF THE RADIATION DOSE

  33. HORMESIS?

  34. RADIATION DOSE RESPONSE

  35. CANCER, LEUKEMIA, & GENETIC EFFECTS FOLLOW: LINEAR NON-TRESHOLD DOSE RESPONSE RELATIONSHIP

  36. SKIN EFFECTS DURING FLUORO FOLLOW: SIGMOID DOSE RESPONSE RELATIONSHIP

  37. DIRECT ACTION, BIOLOGIC DAMAGE OCCURS AS A RESULT OF THE IONIZATION OF ATOMS ON MASTER OR KEY MOLECULE INDIRECT ACTION EFFECTS PRODUCED BY REACTIVE FREE RADICALS CREATED BY THE INTERACTIONOF RADIATION WITH WATER MOLECULE DIRECT & INDIRECT ACTION

  38. DIRECT ACTION • THE IONIZATION OR EXCITATION OF THE ATOMS OF BIOLOGIC MACROMOLECULES RESULTS IN THE BREAKAGE OF MACROMOLECULES’ CHEMICAL BONDS- MACROMOLECULE BECOMES ABNORMAL STRUCTURE

  39. INDIRECT ACTION- RADI0LYSIS OF WATER • HOH + RADIATION HOH + + e • HOH + e HOH - • HOH + H ++OH * • HOH - OH - + H * • H + + OH - HOH ( NO DAMAGE) • OH * + H * HOH ( NO DAMAGE) • OH * + OH * H2O2 • H * + O2 HO2

  40. X-RAY PHOTON FAST ELECTRON ION RADICAL FREE RADICAL CHEMICAL CHANGE BIOLOGIC EFFECT

  41. MOST DAMAGE COMES FROM OH * RADICAL

  42. INDIRECT ACTION ON MACROMOLECULE

  43. EFFECTS OF IONIZING RADIATION ON DNA • BASE DAMAGE • SINGLE STRAND BRAKE • DOUBLE STRAND BRAKE • CROSSLINKING

  44. 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

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

  46. DOUBLE STRAND BRAKES VERY DIFFICULT FOR THE CELL TO BE REPAIRED. CAN LEAD TO CELL KILLING. IF REPAIR DOESN’T TAKE PLACE, THE DNA CHAINS CAN SEPARATE. SERIOUS CONSEQUENCE TO CELL LIFE.

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