Rad Bio Flashcards
(200 cards)
1
Q
2 purines are ?
A
adenine & guanine
2
Q
2 pyrimidines are?
A
thymine & cytosine
3
Q
adenine binds with
A
thymine
4
Q
guanine binds with
A
cytosine
5
Q
mitosis phases (4)
A
- prophase
- metaphase
- anaphase
- telephase
6
Q
what happens in prophase
A
- spindle forms
- membrane begins to disappear
7
Q
what happens in metaphase
A
chrom line up @ equator
8
Q
what happens in anaphase
A
migrate to opp poles
9
Q
telophase main process
A
division (cytokenesis)
10
Q
what happens during G1?
A
rapid growth & active metabolism
11
Q
S phase fxn & sensitivity?
A
- DNA synthesis
- least sensitive
12
Q
G2 fxn & sensitivity?
A
- prepare for cell division
- highly sensitive
13
Q
M fxn & sensitivity?
A
- cell divides
- most sensitive
14
Q
what happens during G0?
A
resting phase
15
Q
linear quadrant model surviving fx = ?
A
alpha (a)dose + beta (B) dose squared
16
Q
alpha (a) proportional to:
A
dose
17
Q
beta (B) proportional to:
A
dose squared
18
Q
tumor display for a/B ratio?
A
tumors tend to display higher a/B ratio than normal tissue due to lack of repair fxn
19
Q
tumor typical value of a/B
A
10Gy
20
Q
norm tissue typical value of a/B -late effects
A
3 Gy
21
Q
LET definition
A
rate @ which E is deposited as charged particle travels thru matter
22
Q
EMR mass?
A
no mass
23
Q
quantum theory of EMR
A
E is photon traveling in straight but diverging lines
24
Q
RBE stands for
A
relative biologic effect
25
RBE definition
ability to produce specific biologic response w/diff LET
26
what happens in chromosome with damaged base?
- change/loss in base
| - mutation or abberation
27
what happens with double strand break chromosome damage?
both chains break
28
Mammalian cell survival curve shape
semi-log
29
reciprocal of slope & expression of radiosensitivity of cell population value is?
b/n 1-2 Gy
30
radiosensitivity = ? Do
low
31
radioresistant = ? Do
high
32
high dose curve shape
shallow curve
33
curve shape for low doses
steep curve
34
low LET shoulder on cell survival curve
broad shoulder
35
high LET shoulder on cell survival curve
no shoulder
36
division delay dependent on
dose
37
interphase death means
cells die before dividing
38
repair SLD radiation type
x-ray, gamma only
39
repair PLD occurs when
post irradiation conditions are modified
40
inherent sensitivity means
when & if cell divides
41
Bergonie & Tribondeau stated
cell division critical to selective cell killing
42
Ancel & Vitemberger stated
inherent susceptibility of any cell to damage by radiation is same but time of appearance of damage is different
43
appearance of rad damage influenced by ? stress
biological stress
44
greatest stress on cell- ? necessity
necessity for division
45
Rubin & Casarett 5 categories of cell populations
VIM, DIM, multipotential conn tissue, RPM, FPM
46
VIM definition
vegetative intermitotic delay
47
DIM stands for
differential intermitotic delay
48
RPM stands for
reverting post mitotic delay
49
FPM stands for ? & do cells divide?
- fixed post mitotic delay
| - do NOT divide
50
stromal dept found in?
all organs & tissues
51
3 factors that affect cell/tissue after radiation
physical, chemical, biological
52
physical factors (3)
- LET
- RBE
- dose rate
53
large shoulders for neutrons exhibit ? RBE
high RBE than cells & tissues w/small shoulders
54
dose rate most dramatic at what dose rate?
most dramatic b/n 1-100 cGy/min
55
high LET exhibits ? dose rate effect
high LET does NOT show dose rate effect
56
nitroimidazoles mimic
O2
57
halogenated pyrimidines substitute ?
substitute for base thymidine in DNA
58
radiation protectors reduce dose by factor of
1.5-2
59
biological factors (2)
- cell cycle (G, S, G2, M)
| - intracellular repair (SLD, PLD)
60
acute effects have ? a/B ratio
high
61
late effects have ? a/B ratio
low
62
structural tissue tolerance
parallel organiz, serial organiz
63
parallel organization shows pronounced
volume effect (lung)
64
serial organization shows little
volume effect (spinal cord)
65
as dose rate decreases cell killing ?
increases= b/c cells continue to progress thru cell cycle & become arrested in G2 phase
66
acute effect causes depletion of ? cells
parenchymal cells
67
healing is fxn of ?
dose & organ irradiation
68
repair
- replacement by diff cells
| - only after high doses so regen not poss
69
hemopoietic system made up of
bone marrow, circulating blood, lymphoid organs
70
liver rad hepatitis dose
35-45Gy
71
dose lungs respond to
> 10Gy
72
radiation nephritis due to
loss of tubules
73
which part of spine most sensitive
c & t spine more sensitive than L
74
LD 50/30 rad syndrome whole body irrad dose
450 rad (cGy)
75
hemopoietic syndrome dose
1-10 Gy
76
GI system syndrome dose
10-100Gy
77
CNS system syndrome dose
> 100Gy
78
russell & russell developed what
stages of fetal development
79
greatest variety of congenital abnormalities happen when?
23-37 day
80
fetus most sensitive at what time?
1st 6 wks
81
linear model assumes
risk per rad same @ low doses as high
82
committed dose is
exposure is from radionuclide
83
spontaneous abortion dose/time frame
10rad (0.10Gy) during 1st 6 wks
84
cell loss carcinoma vs sarcoma
carcinoma shows > cell loss than sarcoma
85
tumor growth balance of 3 factors
1=cell cycle time
2= growth fx
3= cell loss
86
hyperthermia best in what cell phase
S phase sensitive to heat
87
mean latent time for appearance of all rad-induced CA
25 yrs
88
mean survival time meaning
avg time b/n lethality & death
89
spontaneous abortion dose & time during pregnancy
exposure 50-200 cGy to fetus in 1st trimester
90
dose response relationship y axis is ?
response
91
TER stands for
thermal enhancement ratio
92
RBE stands for
relative biological effectiveness
93
early effects dependency total dose is ?
total dose = high
94
late effects dependency total dose is ?
total dose= high
95
therapeutic ratio
normal tissue tolerance dose/tumor lethal dose
96
deterministic effect aka ?
non-stochastic effect
97
stochastic effect limited to what effects?
ca & genetic effects
98
abnormal cell proliferation occurs when
differentiation is disrupted
99
protoplasm is made mostly of
70-85% H2O
100
nucleus houses
DNA & RNA
101
alpha (a) killing
single hit killing
102
alpha (a) repair?
no repair
103
alpha (a) curve shape
steep curve
104
beta (B) events
2 separate events
105
beta (B) repair?
chance of repair
106
beta (B) curve shape
shallow curve
107
norm tissue typical value/dose of a/B - early effects
10Gy
108
radiation interaction occurs
rapidly
109
radiation interaction selective?
nonselective
110
radiation interaction damage looks like?
no different than if produced by trauma
111
radiation interaction damage occurs after
latent period
112
direct interaction probability occurs more with ? LET
high LET
113
direct interaction probability %
25
114
Puck & Marcus curve type
1st mammalian cell curve
115
Mammalian cell survival curve x-axis
linear
116
Mammalian cell survival curve y-axis
log
117
Mammalian cell survival curve relationship
b/n radiation dose & cell survival
118
Mammalian cell survival curve fxn
cell kill exponential fxn of dose
119
N of cell survival curve #
b/n 2-10 = target #
120
Dq intercepts ? on cell survival curve
Do @ 100% survival
121
Dq dose
quasi-threshold dose
122
Do % die on cell survival curve
63% die
123
high dose curve sensitivity
less sensitive
124
low LET on cell survival-repair?
yes- will repair
125
high LET on cell survival curve- repair?
no
126
fate of rad cells during division
interphase death
127
fate of radiated cells during division
reproductive failure
128
indirect interaction produces
free radicals with H2O
129
indirect interaction occurs ?%
75
130
free radicals produce
ion pair OH & H
131
free radical rxn toxic
join other free rad to make H2O2
132
free radical rxn combine with norm compound
form new free rad
133
LET unit
keV/micrometer
134
EMR charge
no charge
135
EMR speed
- speed of light
- 3 x 10^8 m/s
- 3 X 10^10 cm/s
136
RBE formula
dose of std radiation (250 keV)/dose another radiation
137
does single strand break on chromosome repair?
yes, usually repairs
138
division delay happens in
G2 & S phase
139
interphase death undiff cells
occurs at lower doses
140
interphase death dependent on
dose
141
reproductive failure occurs at what dose
> 10Gy
142
reproductive failure is dependent on
dose
143
SLD repair occurs
when 2 doses separated by time
144
SLD repair happens unless
another dose given
145
SLD repair larger when
2 separate doses than with 1 large dose
146
PLD repair type of radiation
only low LET radiation
147
PLD repair demonstrated after
1 dose radiation
148
Bergonie & Tribondeau dividing cell
actively dividing
149
Bergonie & Tribondeau cell diff
undiff
150
Bergonie & Tribondeau dividing future
long dividing future
151
appearance radiation damage influenced by ? conditions
conditions to which cells exposed pre & post irrad
152
stem cell examples
- basal
- bone marrow
- crypts of Lieberkuhn
- spermatogonia
153
static cell differentiation
fully differentiated
154
static cell examples (2)
- adult nerve cell
| - adult muscle
155
VIM cell characteristics
rapidly dividing, undiff, short life
156
VIM sensitivity
MOST sensitive
157
VIM cell examples
- skin basal
- crypt cell
- type A spermatogonia
- erythroblasts
158
RBE incr as dose per fx ?
decr
159
OER value
2.5
160
OER less after ? doses
low
161
OER more pronounced with ? radiation
low LET
162
nitroimidazoles examples
- miso
- SR2058
- R003 8799
163
halogenated pyrimidines sensitize cell by factor of
2
164
sulfhydryl group is a radiation ?
protector
165
W2721 is a radiation ?
protector
166
radiation protectors used in ? treatments
intra-op & TBI
167
hemorrhage is ? change
acute
168
sebaceous & sweat glands sensitivity
radioresistant
169
eye dose cataracts single dose
4Gy
170
telegiectasia
small dilated blood vessels
171
sclerosis
hardening of tissue
172
both kidneys shielded to total dose of
26 Gy
173
fatal nephritis dose
28Gy in 5 wks to both kidneys
174
exclusion of ?/3 greatly minimizes kidney failure
1/3
175
preimplantation time frame
conception to 10 days
176
organogenesis time frame
10 days to 6 weeks
177
fetal time frame
6 weeks to growth
178
committed dose equivalent time frame
50 yrs following intake of radionuclide (working life of individual)
179
hyperfractionation increases ? over same time
total dose
180
hyperfractionation fraction size is
doubled
181
hyperfractionation total dose incr/decr
incr
182
hyperfractionation spares what kind of tissue
late responding by decreasing size of dose per fx
183
hyperfractionation associated with ? effects
acute
184
accelerated fx dose pattern
- reduces overall duration w/o significant chg in size of dose/fx or total dose
- 2 times a day
185
accelerated is associated with
increased acute effects
186
hyperthermia kills at low ?
pH
187
hyperthermia inhibits repair of
DNA (SLD/PLD)
188
hyperthermia temp/duration
41-45*C (106-113*F) for 30-60 min
189
hyperthermia formula
w/o heat divided by w/heat
190
dose response relationship x- axis is ?
dose in Gy
191
TER formula
ratio of dose w/o heat divided by w/heat for given effect
192
RBE formula
ratio of standard 250 keV divided by given dose of other quality radiation
193
early effects dependency time is ?
high
194
early effects dependency dose per fx is ?
low
195
late effects dependency time is ?
low
196
late effects dependency dose per fx is?
high
197
deterministic effects is defined as
somatic effect that increases in severity as a rad dose increases above dose threshold
198
stochastic effect is ? induced injury
radiation
199
stochastic effect is ? effect
all or nothing
200
OER for photon/electron therapy is
2.5-3
