Etiology of Neoplasia

Question 1

agents known to cause neoplasia

Answer 1

carcinogen

Question 2

developmental process of neoplastic transformation occuring in cells

Answer 2

carcinogenesis

Question 3

classes of carcinogens

Answer 3

✓ direct-reacting carcinogens
✓ procarcinogen
✓ initiator
✓ promoter or co-carcinogen
✓ complete carcinogen

Question 4

these are reactive substances that require no activation by biologic processes

Answer 4

direct-reacting carcinogens

Question 5

agents that must be metabolized in the animal body to the “proximate” or ultimate carcinogen

Answer 5

procarcinogen

Question 6

these may be direct-reacting or procarcinogen , or may not be a carcinogen at all but are capable of initiating a change in the cell that leads to neoplastic transformation

Answer 6

initiator

Question 7

agents that then applied after initiation promotes the development of tumors

Answer 7

promoter or co-carcinogen

Question 8

act as both initiator and promoter

Answer 8

complete carcinogen

Question 9

Major categories of Carcinogens

Answer 9

✓ physical agents
✓ oncogenic viruses

Question 10

these includes ionizing radiation has some mutational effects on cells that possibly lead to neoplastic transformation

Answer 10

physical agents

Question 11

causes mutational effect and damage the DNA in cells

Answer 11

ultraviolet light

Question 12

such as burns act as co-carcinogen by increasing mitotic rates in the affected area

Answer 12

trauma

Question 13

produces neoplasia due to probably to chronic long-standing irritation

Answer 13

solid state

Question 14

can produce tumors in animals

Answer 14

oncogenic virus

Question 15

Five Major DNA viral families

Answer 15

papova- hepatitis B-, adeno-, herpes-, and pox viruses

Question 16

the genome of retroviruses is?

Answer 16

diploid and single-stranded RNA

Question 17

types of chemical carcinogens include naturally occuring substances such as;

Answer 17

✓ aflatoxin
✓ nitrosamine
✓ cycasin

Question 18

plant alkaloid

Answer 18

cycasin

Question 19

usually occurs over an extended period of exposure to the chemical

Answer 19

chemical carcinogenesis

Question 20

Several theories have been proposed to explain carcinogenesis, what are these?

Answer 20

✓ somatic mutation theory
✓ epigenetic theory
✓ oncogene theory

Question 21

this theory explains that damage DNA leads to transformation that could be heritable and passed from generation to generation

Answer 21

somatic mutation theory

Question 22

this theory states that all cells contain the complete genome capable of producing the characteristics of malignancy

Answer 22

epigenetic theory

Question 23

this theory postulates that the oncogenes of transforming retroviruses are derived from normal cellular genes (called proto-oncogenes)

Answer 23

oncogene theory