Chapter 1 Steve

Front 1

Discovery of X-Rays

Back 1

William Conrad Roentgen 1895

Front 2

Discovery of Radium

Back 2

Pierre and Marie Curie 1898

Front 3

Thomas Edison's assitant

Back 3

Clarence Daily 1865-1904

Front 4

Mihran Kassabian

Back 4

1870-1910 Early radiography pioneer, Documented death by radiation, kept a journal and photographs of his hands.

Front 5

Bergonie and Tribondeau

Back 5

Discovery of cells are more radiosensitive when "immature"

Front 6

Law of Bergonie and Tribondeau

Back 6

1. Stem or immature cells are more radiosensitive than mature cells.

2. Younger tissues and organs are more radiosensitive older tissues and organs.

3. The higher the metabolic cell activity, the more radiosensitive it it.

4. The greater the proliferation and growth rate for tissues, the greater the radio sensitivity.

Front 7

Proliferation rate

Back 7

How much a cell divides. The more they divide, the weaker they are.

Front 8

Ancel and Vitemberger

Back 8

1925 Modified the law of Bergonie and Tribondeau. Radiation damages certain cells based on two factors:

1. The amount the biologic stress the cell receives.

2. Pre- and post-irradiation conditions to which the cell is exposed.

Front 9

Direct effects

Back 9

Direct ionization along charged particle tracks caused direct effects (original ionization occurs directly on target molecule.)

Front 10

Indirect effects

Back 10

The formation of free radicals caused indirect effects (original ionization occurs with water and transfers ionization to target molecule)

Front 11

Fractionation theory

Back 11

Spreading out smaller doses.

Front 12

Repopulation and protraction

Back 12

Critically effects normal tissues too.

Front 13

Protraction

Back 13

given small amounts of radiation at a time. Cells can better repair themselves.

Front 14

Mutagenesis

Back 14

1927 Muller studied mutations on fruit flies

Front 15

Effects of oxygen and hydrolysis of water

Back 15

1940 Charles Rick determined oxygen makes cells more radiosensitive.

Front 16

Oxygen effect

Back 16

Increased production of free radicals when ionizing radiation is delivered in the presence of oxygen.

Front 17

D. Lea

Back 17

1946 research on the hydrolysis of water with the resulting liberation of free radicals.

(When radiation hits cytoplasm)

Front 18

John Read and John Thoday

Back 18

1947 Found variations of chromosome aberrations produced by X-rays depends on the amount of oxygen present.