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Flashcards in Dose-Response Relationships Deck (32)
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1
Q

the characteristic of exposure and the spectrum of toxic effects come together as

A

dose-response relationship

2
Q

two types of dose response relationships

A

individual dose-response relationship

quantal dose-response relationship

3
Q

describes the response of and individual organism to varying doses of a chemical

A

individual dose relationship

4
Q

characterizes the distribution of individual responses to different does in a population of individual organisms

A

quantal dose relationship

5
Q

bell shaped curve

A

normal frequency distribution

6
Q

the reason for normal distribution

A

differences in susceptibility to chemicals among individuals

7
Q

animals responding to the left end of the curve are

A

hypersusceptible

8
Q

animals responding to the right end of the curve are

A

resistant

9
Q

the minimally ED of any chemical that evokes a stated all or none response is the ___which cannot be determined experimentally

A

threshold dose

10
Q

units of NED are converted by the addition of five to the value to avoid negative numbers

A

probit units

11
Q

50% of the population will show an effect from a chemical

A

ED50

12
Q

50% of the population will show a toxic dose from a chemical

A

TD50

13
Q

50% of the population will die from exposure to a chemical

A

LD50

14
Q

the “graded” dose relationship in an individual over the entire dose range is actually

A

U-shaped

15
Q

the region of the dose response relationship for essential nutrients is commonly referred to as

A

deficiency

16
Q

there is considerable evidence to suggest that some nonnuritional toxic substances may also impart beneficial or stimulatory effects at low doses but that at high doses they produce adverse effects

A

hormesis

17
Q

factors to consider when talking about the threshold concept

A

test population size
time periods
endpoints
ED01 vs NOAEC

18
Q

important assumptions for generating proper dose-response curves

A

effects are caused by dosed chemical
magnitude of response is actually related to dose
response can be quantified reliable

19
Q

three assumptions that cover “magnitude of response is actually related to the dose”

A

there is a target site with which the chemical interacts
response is related to concentration at target site
concentration at target site is related to dose

20
Q

the ratio of the dose required to produce a toxic effect to the dose needed to elicit the desired therapeutic response

A

therapeutic index

21
Q

the larger the ratio the ____the relative safety

A

greater

22
Q

use the ED99 for the desired effect and the TD1 for the undesired effect

A

Margin of Safety (MOS)

23
Q

a chemical produces injury to one kind of living matter without harming another form of life even though the two may exist in intimate contact

A

selective toxicity

24
Q

generally the first toxicity test performed on a new chemical is

A

acute toxicity

25
Q

5 objectives of acute toxicity

A
  1. provide estimate for intrinsic toxicity of a substance
  2. provide information on target organs
  3. identify species differences and susceptible species
  4. establish the reversibility of the toxic response
  5. provide information that will assists the design and dose selection for longer term studies
26
Q

performed to obtain information on the toxicity of a chemical after repeated administration

A

subacute toxicity

27
Q

common duration for subchronic testing

A

90 days

28
Q

principle goals of subchronic testing

A

establish the NOAEC

further identify and characterize specific organ(s) affected by the test compound

29
Q

use to establish regulatory values for acceptable pollutant levels

A

reference dose

30
Q

uses all the experimental data to fit 1 or more dose-response curves

A

benchmark dose

31
Q

performed similarly to subchronic studies except that the period of exposure is longer than three months

A

chronic toxicity

32
Q

dose that suppresses body weight gain slightly

A

maximum tolerable dose