Tox Exam 2 Questions Verified
Solutions
Metals Continued - ANSWER--Toxic effects are very non-specific
-The young and elderly are the most susceptible to metal toxicity. Occupational hazards
also of concern
-Metals exist in the environment and are neither created nor destroyed by humans. This
property makes them different from all other toxic agents
Carcinogen - ANSWER-An agent (typically a chemical or virus) which when
administered to an organism results in a significant increase in neoplasm
Neoplasm - ANSWER-Genetically altered tissue which shows abnormal gene
expression and growth control Neoplasia lesions can grow into neoplasm (tumor)
Genotoxic - ANSWER-Chemical carcinogens which physically interact with DNA
causing "damage" to the DNA molecule
Benign - ANSWER-Lesions of slow growth that do not invade surrounding tissues. Uses
suffix "oma"; fibroma
Malignant - ANSWER-Lesion which shows aggressive growth and do invade other
tissue/organs. Uses suffix "sarcoma"; fibrosarcoma
Metastases - ANSWER-Secondary growth (surrounding tissues/organ) derived from the
Neoplasm
Cancer - ANSWER-A malignant tumor that has the ability to metastasize or invade into
surrounding tissues
Tumor - ANSWER-A general term for an in trolled growth of cells that becomes
progressively worse with time. Tumors may be benign or malignant
Neoplasia - ANSWER-The growth of new tissue with abnormal and unregulated cellular
proliferation
Non-Genotoxic Carcinogens General - ANSWER--Do not form DNA adducts
-Stimulate cell proliferation
-Can be organic or inorganic (metals)
-As, Cr, Cd, Pb, Ni
, Non-Genotoxic Carcinogens: Mitogens - ANSWER--Stimulation of proliferation
-Mutations may occur secondarily to cell proliferation
-may cause preferential growth of preneoplastic cells
Non-Genotoxic Carcinogens: Cytotoxicants - ANSWER--Cytolethal
-induce regenerative growth
-mutations may occur secondarily to cell proliferation
Stages of Carcinogensis: Initiation - ANSWER--DNA damage resulting in a mutation
-If mutation is detrimental to cell Function cell may die (apoptosis)
Stages of Carcinogensis: Promotion - ANSWER--Cell division (caused by tumor
promotion) of the initiated cells resulting in a preneoplastic lesion
-Tumor Promotors are not mutagenic but cause the proliferation of initiated cells
Stages of Carcinogensis: Progression - ANSWER--Cell division/growth in which the
preneoplastic lesions becomes neoplasm is cancers
-Irreversible
-Metastases can occur at this stage
Genotoxic DNA Reactive Chemical Carcinogens - ANSWER--Chemical carcinogens are
typically electrophilic molecules which react with nucleophilic molecules, including
biological macromolecules such as DNA
Direct Acting Carcinogens - ANSWER-Highly reactive electrophiles which do not require
activation
Indirect Acting Carcinogens - ANSWER-Procarcinogens, require chemical
activation/metabolism in order to be carcinogenic. Majority of chemical carcinogens fall
into this category
Classes of Genotoxic Carcinogens - ANSWER--Polyaromatic Hydrocarbons
-Alkylating Agents
-Aromatic Amines
Polyaromatic Hydrocarbons - ANSWER--Produced in tobacco smoke and in the burning
of fossil fuels
-Procarcinogens are activated by Cytochrome P450 oxidation
-Oxidative products bind to the nitrogen bases of DNA, in particular guanine
Alkylation Agents - ANSWER--Nitrogen mustards, nitrosamines and nitrosoureas are
the most common
-Guanine and adenine nitrogen bases are the typical alkylation target
Aromatic Amines/Amides - ANSWER--Common in the chemical industry but also with
use of tobacco products
Solutions
Metals Continued - ANSWER--Toxic effects are very non-specific
-The young and elderly are the most susceptible to metal toxicity. Occupational hazards
also of concern
-Metals exist in the environment and are neither created nor destroyed by humans. This
property makes them different from all other toxic agents
Carcinogen - ANSWER-An agent (typically a chemical or virus) which when
administered to an organism results in a significant increase in neoplasm
Neoplasm - ANSWER-Genetically altered tissue which shows abnormal gene
expression and growth control Neoplasia lesions can grow into neoplasm (tumor)
Genotoxic - ANSWER-Chemical carcinogens which physically interact with DNA
causing "damage" to the DNA molecule
Benign - ANSWER-Lesions of slow growth that do not invade surrounding tissues. Uses
suffix "oma"; fibroma
Malignant - ANSWER-Lesion which shows aggressive growth and do invade other
tissue/organs. Uses suffix "sarcoma"; fibrosarcoma
Metastases - ANSWER-Secondary growth (surrounding tissues/organ) derived from the
Neoplasm
Cancer - ANSWER-A malignant tumor that has the ability to metastasize or invade into
surrounding tissues
Tumor - ANSWER-A general term for an in trolled growth of cells that becomes
progressively worse with time. Tumors may be benign or malignant
Neoplasia - ANSWER-The growth of new tissue with abnormal and unregulated cellular
proliferation
Non-Genotoxic Carcinogens General - ANSWER--Do not form DNA adducts
-Stimulate cell proliferation
-Can be organic or inorganic (metals)
-As, Cr, Cd, Pb, Ni
, Non-Genotoxic Carcinogens: Mitogens - ANSWER--Stimulation of proliferation
-Mutations may occur secondarily to cell proliferation
-may cause preferential growth of preneoplastic cells
Non-Genotoxic Carcinogens: Cytotoxicants - ANSWER--Cytolethal
-induce regenerative growth
-mutations may occur secondarily to cell proliferation
Stages of Carcinogensis: Initiation - ANSWER--DNA damage resulting in a mutation
-If mutation is detrimental to cell Function cell may die (apoptosis)
Stages of Carcinogensis: Promotion - ANSWER--Cell division (caused by tumor
promotion) of the initiated cells resulting in a preneoplastic lesion
-Tumor Promotors are not mutagenic but cause the proliferation of initiated cells
Stages of Carcinogensis: Progression - ANSWER--Cell division/growth in which the
preneoplastic lesions becomes neoplasm is cancers
-Irreversible
-Metastases can occur at this stage
Genotoxic DNA Reactive Chemical Carcinogens - ANSWER--Chemical carcinogens are
typically electrophilic molecules which react with nucleophilic molecules, including
biological macromolecules such as DNA
Direct Acting Carcinogens - ANSWER-Highly reactive electrophiles which do not require
activation
Indirect Acting Carcinogens - ANSWER-Procarcinogens, require chemical
activation/metabolism in order to be carcinogenic. Majority of chemical carcinogens fall
into this category
Classes of Genotoxic Carcinogens - ANSWER--Polyaromatic Hydrocarbons
-Alkylating Agents
-Aromatic Amines
Polyaromatic Hydrocarbons - ANSWER--Produced in tobacco smoke and in the burning
of fossil fuels
-Procarcinogens are activated by Cytochrome P450 oxidation
-Oxidative products bind to the nitrogen bases of DNA, in particular guanine
Alkylation Agents - ANSWER--Nitrogen mustards, nitrosamines and nitrosoureas are
the most common
-Guanine and adenine nitrogen bases are the typical alkylation target
Aromatic Amines/Amides - ANSWER--Common in the chemical industry but also with
use of tobacco products
