Term
| What is hypersensitivity? |
|
Definition
| Hypersensitivity is an exaggerated response of the immune system to an antigen that results in a pathological immune response after re-exposure. |
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Term
| What are the three main categories of hypersensitivity reactions? |
|
Definition
The three main categories of hypsersensitivity reactions are:
Allergy
Autoimmunity
Alloimmunity |
|
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Term
|
Definition
| An allergy is type of hypersensitivity reaction to environmental antigens. |
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Term
|
Definition
| Autoimmunity is a type of hypersensitivity reaction that occurs when an individual's immune system begins to recognize self-antigens as foreign and mounts an attack against them. |
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Term
|
Definition
| Alloimmunity is a hypsersensitivity reaction that occurs when an individual's immune system reacts against antigens on the tissues of other members of the same species. |
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Term
|
Definition
| Anaphylaxis is the most severe immediate hypersensitivity reaction and is almost life-threatening. It occurs in minutes to a few hours after exposure to some foreign protein or drug. |
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Term
| How long after onset of anaphylactic shock, which may result from anaphylaxis, does a person have before death? |
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Definition
| Measures must be taken within 20 minutes of anaphylactic shock or it may be irreversible. |
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Term
| What sort of antibody response is seen in Type I Hypersensitivity? |
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Definition
| Type I Hypersensitivity is characterized by production of IgE after exporuse to an antigen. |
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Term
| What are most Type I Hypersensitivty reactions against? |
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Definition
| Most Type I Hypersensitivity reactions are against environmental allergens (proteins). |
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Term
| What type of hypersensitivity reaction are most common allergic reactions? |
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Definition
| Most common allergic reactions are Type I Hypersensitivity reactions. |
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Term
| What are the clinical manifestations of Type I Hypersensitivity? |
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Definition
The clinical manifestations of Type I Hypersensitivity are attributable mostly to the effects of histamine.
Itching
Angioedema
Urticaria
Bronchospasm
Hypotension
Dysrhythmias
Gastrointestinal cramping
|
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Term
| Where are the target tissues of Type I Hypersensitivity located and what cell type releases histamine? |
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Definition
The target tissues Type I Hypersensitivity are concentrated in the GI tract, skin, and respiratory tract.
The target tissues of Type I Hypersensitivity contain large numbers of mast cells, which release histamine. |
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Term
| What type of Hypersensitivity is Bronchial asthma? |
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Definition
| Bronchial asthma is Type I Hypersensitivity |
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Term
| What induces Bronchial asthma? |
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Definition
| Bronchial asthma is induced by inhalation of environmental antigens |
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Term
| What three events resulting from inflammation in bronchial asthma result in the narrowing of the airways? |
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Definition
| Inflammation produces mucosal edema, increased mucus secretion, and bronchospasm. All three result in narrowing of the airways in bronchial asthma. |
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Term
| What is the hygeine hypothesis? |
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Definition
| The hygeine hypothesis proposes that the increase of allergies and hypersensitivity reactions in recent years is due to decreasing exposure to common antigens in early childhood. Individuals' immune systems are more likely to react too strongly to foreign antigens. |
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Term
| What are the clinical manifestations of bronchial asthma? |
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Definition
The clinical manifestations of bronchial asthma are:
Dyspnea
Wheezing
Hypertrophy of smooth muscle (Exaggerates bronchoconstriction) |
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Term
|
Definition
| Dyspnea means difficulty breathing. |
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Term
|
Definition
| Urticaria is commonly known as hives. |
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Term
|
Definition
| Angioedema is swelling caused by exudation. It is seen in Type I Hypersensitivity. |
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Term
|
Definition
| Exudation is fluid seepage from blood vessels into the tissues. |
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Term
| What is Type II Hypersensitivity in response to? |
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Definition
| Type II Hypersensitivity reactions are tissue-specific. Antibodies react with antigens on the target cell's plasma membrane. |
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Term
| What kind of hypersensitivity reaction causes hemolysis? |
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Definition
| Hemolytic reactions are Type II Hypersensitivity reactions. |
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Term
| What is a hemolytic reaction? |
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Definition
| A hemolytic reaction causes the destruction of red blood cells. |
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Term
| What sort of reaction causes erythroblastosis fetalis? |
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Definition
| Erythroblastosis, an attack on fetal RBCs by maternal antibodies, is a transfusion reaction, which is Type II Hypersensitivity. |
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Term
| What causes erythroblastosis fetalis? |
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Definition
Erythroblastosis fetalis results from an Rh- mother carrying an Rh+child after previously carrying an Rh+ child.
At parturition of the first Rh+ child, maternal and fetal blood mix, and the mother develops antibodies against the Rh factor. This class of antibody (IgG) is able to cross the placenta, and mounts an attack against the fetal RBCs. |
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Term
| Why do differences in the Rh system cause maternal antibodies to attack the fetus, but not with the ABO system? |
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Definition
There are several different classes of antibodies. IgG antibodies are produced against the Rh factor and IgM is produced against Protein A/B.
IgM is not able to plass through the placenta, however IgG is able to pass through. |
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Term
| What is the treatment for a baby with erythroblastosis fetalis? |
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Definition
In erythroblastosis fetalis, damaged red blood cells release bilirubin, which causes the baby to be born severely jaundiced. Aditionally, bilirubin, can eventually damage organ systems and must be removed. This is done either by:
Placing the child under a blue light incubator
Transfusion |
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Term
| How can Rh- mothers reduce the risk that a second Rh+ child will suffer from erythroblastosis fetalis? |
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Definition
| The risk for the second child can be reduced by administering anti-Rh antibodies, such as RhoGam, within 72 hours after the birth of the first child. |
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Term
| What type of hypersensitivity is drug-induced hemolysis? |
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Definition
| Drug-induced hemolysis is a Type II Hypersensitivity. |
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Term
| Describe drug-induced hemolysis. |
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Definition
A drug may bind to cells or change the surface antigens.
This starts an attack by the immune system.
The attack stops when drug treatment stops and the cell surface antigens return to normal.
This is an example of Type II Hypersensitivity. |
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Term
| What is Goodpasture's Syndrome? |
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Definition
Goodpasture's Syndrome is a Type II Hypersensitivity reaction.
The basement membrane of the glomerulus of the kidney, and possibly the basement membrane of the pulmonary alveoli of the lungs are attacked by the body's immune system. |
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Term
| What type of reaction is Type III Hypersensitivity? |
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Definition
Type III Hypersensitivity is an immune complex-mediated reaction.
It results from the formation of antigen-antibody complexes ("super antigens") |
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Term
| Describe Immune complex-mediated reactions. |
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Definition
Antigen-antibody complexes form and activate a variety of serum factors, especially the complement system.
The complexes precipitate in vulnerable areas (such as joints).
Inflammation results in tissue destruction (flesh-eating bacteria).
Streptococcus pyogenes and serum sickness. |
|
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Term
|
Definition
| Serum sickness results from injection of large doses of foreign material which can result in various types of arthritis, glomerulitis, and vasculitis. |
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Term
| What type of Hypersensitivity reaction is the reaction to penicillin? |
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Definition
| The reaction to penicillin is a Type III Hypersensitivity reaction (Immune Complex-Mediated). |
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Term
| What type of reaction is Type IV Hypersensitivity reaction? |
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Definition
| A Type IV Hypersensitivity reaction is a cell-mediated tissue reaction (specially sensitized T Lymphocytes). It is an enhanced inflammatory response. |
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Term
| What type of hypersensitivity reaction is contact dermatitis? |
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Definition
| Contact dermatitis is a Type IV Hypersensitivity reaction (T-Cell Mediated) |
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Term
| Do Type IV Hypersensitivity reactions occur immediately or are they delayed? |
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Definition
| Type IV Hypersensitivity is a delayed-type response. |
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Term
| Can autoimmune diseases be inherited? |
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Definition
| Autoimmunity can be familial. |
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Term
| Some forms of diabetes mellitus are autoimmune. Which forms tend to be? |
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Definition
| Late-onset diabetes tends to be the result of an autoimmune response against the Islets of Langerhans (inhibiting the production insulin) |
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Term
| What sort of hypersensitivity response is Myasthenia Gravis, Grave's Disease, and Rheumatoid Arthritis? |
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Definition
| All three are autoimmune. |
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Term
| Transplant/Graft rejection is a type of alloimmunity. What events lead to rejection? |
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Definition
| If the MHC antigens of the transplant/graft are too disimilar to the recipient's antigens, the body rejects the transplant/graft. Both antibody- and cell-mediated response. |
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Term
| Give three examples of alloimmunity. |
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Definition
Three examples of alloimmunity are:
Erythroblastosis fetalis
Transfusion reactions
Transplant/Graft rejections |
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Term
| What is the difference in primary and secondary immune deficiencies? |
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Definition
A primary immune deficiency results from a failure of an essential part of the immune system to develop.
A secondary immune deficiency results from the loss of a previously effective immune system |
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Term
| What is a primary immune deficiency? Give an example |
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Definition
| A primary immune deficiency results from a failure of an essential part of the immune system to develop. An example of a primary immune deficiency is Stem Cell Deficiency (Sever Combined Immunodeficiency Disease [SCID]). |
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Term
| What type of disease is Stem Cell Deficiency? How does it act? Treatment? |
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Definition
Stem Cell Deficiency (SCID) is a primary immune deficiency. It is a deficiency of the stem cell population that forms the T and B lymphocytes (which provide cell-mediated and antibody-mediated immunity). Little, if any, immune response is made against an antigen.
The thymus of a person with SCID resembles that of a 6-8 week old fetus.
Infants often die within the 1st year of life unless placed in a germ-free environment.
Treatment of SCID: a matching donor must be found for a bone marrow transplantation. |
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Term
| What does pluripotent mean? |
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Definition
| Pluripotent, referring to stem cells, means that the cell may differentiate into one of many different kinds of cells. |
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Term
| Why does the thymus of a person with SCID (Severe Combined Immunodeficiency Disease) resemble that of a 6-8 week old fetus? |
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Definition
| The thymus of a person with SCID is very underdeveloped, due in part to the absence of lymphocytes to process within it. |
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Term
| What is Graft-versus-host disease? |
|
Definition
| Graft-versus-host disease is a phenomenon that occurs in recipients of a bone marrow transplantation who have a stem cell deficiency. Although native cells cannot mount an attack against the transplant (as they are not able to be made), lymphoyctes made by the transplanted bone marrow can attack the recipient's cells. |
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Term
| What is the current status of the attempt to treat SCID with genetic engineering? |
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Definition
Genetic engineering was suggested as a means to correct Stem Cell Deficiency. A virus was proposed to insert a functional gene to differentiate stem cells into lymphocytes into the cells' DNA.
This method of transfer is very inefficient, as not all cells are infected. Additionally, researchers cannot control where the virus inserts and it may insert into a gene that controls cancer. Results are very variable and currently, this method of research has been stopped in the U.S. |
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Term
| What is a secondary immune deficiency? |
|
Definition
| A secondary immune deficiency is a loss of a previously effective immune system. |
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|
Term
| What may cause a secondary immune deficiency? |
|
Definition
A secondary immune deficiency may be caused by:
Stress
Malnutrition
System infection
Cancer
Renal disease
Radiation therapy
Immunosuppressive drugs
Aging
AIDS |
|
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Term
| How does radiation therapy cause a secondary immune system deficiency? |
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Definition
| Radiation therapy, often used to treat cancer, affects rapidly proliferating cells. In addition to affecting the cancerous cells, it damages cells of the GI tract and the bone marrow. These are cells that divide rapidly. T and B lymphocyte production is affected. |
|
|
Term
| What does pluripotent mean? |
|
Definition
| Pluripotent, referring to stem cells, means that the cell may differentiate into one of many different kinds of cells. |
|
|
Term
| Why does the thymus of a person with SCID (Severe Combined Immunodeficiency Disease) resemble that of a 6-8 week old fetus? |
|
Definition
| The thymus of a person with SCID is very underdeveloped, due in part to the absence of lymphocytes to process within it. |
|
|
Term
| What is Graft-versus-host disease? |
|
Definition
| Graft-versus-host disease is a phenomenon that occurs in recipients of a bone marrow transplantation who have a stem cell deficiency. Although native cells cannot mount an attack against the transplant (as they are not able to be made), lymphoyctes made by the transplanted bone marrow can attack the recipient's cells. |
|
|
Term
| What is the current status of the attempt to treat SCID with genetic engineering? |
|
Definition
Genetic engineering was suggested as a means to correct Stem Cell Deficiency. A virus was proposed to insert a functional gene to differentiate stem cells into lymphocytes into the cells' DNA.
This method of transfer is very inefficient, as not all cells are infected. Additionally, researchers cannot control where the virus inserts and it may insert into a gene that controls cancer. Results are very variable and currently, this method of research has been stopped in the U.S. |
|
|
Term
| What is a secondary immune deficiency? |
|
Definition
| A secondary immune deficiency is a loss of a previously effective immune system. It results in a decreased ability to maintain an inflammatory or immune response and increases susceptibility to infection by viruses, fungi, and bacteria. |
|
|
Term
| What may cause a secondary immune system deficiency? |
|
Definition
A secondary immune deficiency may be caused due to:
Stress
Malnutrition
System infection
Cancer
Renal disease
Radiation therapy
Immunosuppressive drugs
Aging
AIDS |
|
|
Term
| Are humans affected by HIV-1 or by HIV-2? |
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Definition
| HIV-1 is the form of HIV that affects humans. |
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Term
| When and where did AIDS most likely begin to occur [in humans]? |
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Definition
| AIDS most likely arose in the 1950s in sub-Saharan Africa. Scientists believe it occurred by simian-to-human transmission. |
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Term
| When was HIV-1 discovered? |
|
Definition
| HIV-1 was recognized in 1983-1984. |
|
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Term
| What are the modes of transmission of HIV? |
|
Definition
HIV may be transmitted by:
Sexual activity
Blood-to-blood contamination
Perinatal events |
|
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Term
| In the US, what percentage of people with HIV are homosexual or bisexual? |
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Definition
| In the US, 67% of HIV cases are homosexual or bisexual. |
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Term
| In heterosexual transmission of HIV, which is more likely: man-to-woman or woman-to-man? |
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Definition
| Man-to-woman transmission of HIV is more likely to occur than woman-to-man transmission. 75% of cases are man-to-woman. |
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Term
| Which three groups of people are most likely to suffer from blood-to-blood contamination by HIV? |
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Definition
Blood-to-blood contamination of HIV is mostly to occur if a person is a:
Intravenous (recreational) drug user
Recipient of blood products or transplanted tissue
Healthcare worker (occupational hazard) |
|
|
Term
| What is the rate of transmission of HIV to infants of HIV+ mothers? |
|
Definition
| 20-65% of HIV-positive mothers will transmit the virus to their infant. |
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Term
| How can mother-to-baby transmission of HIV occur? |
|
Definition
Mother-to-baby transmission of HIV may occur during:
Gestation (HIV can cross the placental barrier)
Labor and delivery (mixing of maternal and fetal blood)
Breastfeeding |
|
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Term
| In 2002, how many people worldwide were HIV positive or had AIDS? In 2008? |
|
Definition
In 2002, 42 million people were HIV positive or had AIDS.
In 2008, 33.4 million people were HIV positive or had AIDS |
|
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Term
| In 2002, how many people worldwide were newly infected with HIV? In 2008? |
|
Definition
In 2002, 5 million people were newly infected with HIV.
In 2008, 2.7 million people were newly infected with HIV. |
|
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Term
| In 2008, how many people died worldwide of AIDS? How many people in the US? |
|
Definition
In 2008, 3 million people died of AIDS worldwide.
18,000 of these people were in the US |
|
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Term
| In 2002, how many people in the US had died of AIDS? In 2008? |
|
Definition
| In 2002, more than 460,000 people had died of AIDS in the US. In 2008, more than 600,000 people had died of AIDS. Approximately 140,000 people died due to AIDS between 2002 and 2008. |
|
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Term
| What is the difference between incidence and prevalence? |
|
Definition
Incidence--the number of new cases per year
Prevalence--the total number of cases per year |
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Term
| What sort of virus is HIV? What does this mean for how it infects cells? |
|
Definition
| HIV is a retrovirus. This means that its genetic information is in the form of RNA. Once inside the cell, it uses the cell's machinery to change the RNA to DNA and inserts itself into the cell's DNA. |
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Term
| What is the primary cell surface receptor that HIV binds to? |
|
Definition
| The primary cell surface receptor that HIV binds to is CD4. This means that it primarily infects CD4+ helper T lymphocytes. Eventually, the depletion of these cells will diminish the effectiveness of the cell-mediated immune response. |
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Term
| What are the 4 different conditions a person infected with HIV may be diagnosed with? |
|
Definition
A person exposed to HIV may be diagnosed as:
Serologically negative for HIV-1
Serologically positive but asymptomatic
Early stages of HIV disease
AIDS |
|
|
Term
| What are the criteria for an AIDS diagnosis? |
|
Definition
To be diagnosed with AIDS, a person must:
Be producing antibodies against HIV-1
Have lymphoma of the brain and be younger than 60 years old
Or have lymphoid interstitial pneumonitis and be younger than 13 years. |
|
|
Term
| What are the clinical manifestations of a person with AIDS? |
|
Definition
The clinical manifestations of a person with AIDS are:
Histoplasmosis
Tuberculosis
Salmonella septicemia
Recurrent bacterial infections
HIV wasting syndrome
Lymphoma of the brain
Recurrent fever
Opportunistic infections |
|
|
Term
| What are some opportunistic diseases a person with AIDS is particularly susceptible to? |
|
Definition
Pneumonia carnii
Kaposi's sarcoma
Drug-resistant Microbacterium tuberculosis |
|
|
Term
| What is the latency period between infection with HIV and development of AIDS? |
|
Definition
| The latency period between infection with HIV and development of AIDS is 10-12 years. |
|
|
Term
|
Definition
AIDS is treated in several ways:
Treatment of specific opportunistic diseases by prophylactic use of antibiotics
Antiviral agents
Largely unsuccessful attempts have been made with vaccines and immune system boosters. |
|
|
Term
| Why is a vaccine to HIV hard to develop? |
|
Definition
As a retrovirus, HIV has a very high rate of mutation (100 times that of the cold virus).
Most viral particles are not expressed on the cell surface and therefore anti-HIV antibodies cannot neutralize them.
Additionally, until recently, a good animal model for the study of HIV did not exist. |
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Term
| Immune system boosters were proposed to treat people with HIV. What did they try to use, and why didn't it work? |
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Definition
| Immune system boosters were proposed as a way to treat people with HIV. Activated lymphocytes, Interleuken 2, and interferons were all used. Unfortunately, patients had severe side effects and this treatment was not tolerated well by patients. |
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|
Term
| What has been the most effective treatment of HIV? |
|
Definition
The Highly Active Antiretroviral Therapy (HAART) treatment has been the most successful method of treating people with HIV. It is a combination of three drugs from two different classes of antiviral agents (reverse transcriptase inhibitors and protease inhibitors).
Recently, two new classes of antiviral agents have been added: integrase inhibitors and entrance inhibitors. |
|
|
Term
| What is a reverse transcriptase inhibitor? |
|
Definition
| A reverse transcriptase inhibitor is an antivral agent used to treat people with HIV. This drug prevents the conversion of viral RNA to DNA. |
|
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Term
| What is a protease inhibitor? |
|
Definition
| A protease inhibitor is an antiviral agent used to treat people with HIV. This drug blocks the action of protease so that new viral proteins cannot be cut to the right sizes (this means that the viral proteins will be nonfunctional). |
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Term
| What are the two new classes of drugs that are used to treat HIV? |
|
Definition
| In addition to reverse transcriptase inhibitors and protease inhibitors, scientists have developed two new classes of drugs effective against HIV: Integrase inhibitors and entrance inhibitors. |
|
|
Term
| What is an integrase inhibitor? |
|
Definition
| An integrase inhibitor is an antiviral agent used to treat people with HIV. This drug prevents the genetic information of the viruses from being incorporated into the host's chromosomes. |
|
|
Term
| What is an entrance inhibitor? |
|
Definition
| An entrance inhibitor is an antiviral agent used to treat people with HIV. This drug prevents the virus from entering the cells. |
|
|
Term
| Why are antiviral agents administered in combinations? |
|
Definition
| Combinations of antiviral agents are used to reduce the rate of development of resistance by the virus. |
|
|
Term
| Who pioneered the study of stress in the human body? |
|
Definition
| Hans Selye pioneered the study of stress in the human body. (1951) |
|
|
Term
| What is stress? What is a stressor? |
|
Definition
Stress is the non-specific response of the body to any demand placed on it.
Stressor is any factor which poses a challenge to an organism.
(Stress--response; Stressor--challenge) |
|
|
Term
| What is Generalized Adaptation Syndrome (GAS) |
|
Definition
Generalized Adaptation Syndrome (GAS) describes how the body responds to stress. It consists of three stages:
Alarm
Adaptation (or resistance)
Exhaustion (in the case of chronic stress) |
|
|
Term
| What is the Alarm phase of Generalized Adaptation Syndrome? |
|
Definition
| The Alarm phase of GAS is the first stage. This occurs when the organism detects or recognizes a stressor. |
|
|
Term
| What is the Adaptation (Resistance) phase of Generalized Adaptation Syndrome? |
|
Definition
| The Adaptation (Resistance) Phase of GAS is the second stage. This refers to the physiological compensation for change in the environment. |
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|
Term
| What is the Exhaustion phase of Generalized Adaptation Syndrome? |
|
Definition
| The Exhaustion Phase of GAS is the third stage. It is associated with chronic stress. Resources are depleted and injury to cells or the organism is likely. |
|
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Term
| How soon after being subjected to a stressor does an organism release epinephrine? |
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Definition
| Less than two minutes after being subjected to a stressor, epinephrine levels peak. (This makes it difficult to find the baseline levels of epinephrine). |
|
|
Term
| How soon after being subjected to stressor do cortisol levels peak? |
|
Definition
| About 20-40 minutes after being subjected to a stressor, an organism's cortisol levels peak. |
|
|
Term
| How soon after being subjected to a stressor do glucose levels peak? |
|
Definition
| About 1-4 hours after being subjected to a stressor, an organism's glucose levels peak. |
|
|
Term
| What is the secondary stress response? |
|
Definition
| The secondary stress response helps to provide the energy necessary to deal with an immediate crisis, by the fight or flight response. The release of epinephrine and cortisol mobilize amino acids and glucose to provide energy for the action. |
|
|
Term
| What sort of illnesses or alterations are seen with chronic stress? |
|
Definition
If stress is chronic, the body enters the exhaustion phase.
The immune response is decreased
The thymus atrophies
There is an increased susceptibility to diseases
Increased frequency of peptic ulcers
Increased cardiovascular disease
Increased hypertension
Increased cholesterol levels
Increased cancer risk |
|
|
Term
| Stres directly influences the immune system through which two body systems? |
|
Definition
| Stress directly influences the immune system through the Endocrine System response and the Nervous System response. |
|
|
Term
| Which hormones and peptides does the endocrine system release in response to stress that affect the immune system? |
|
Definition
The endocrine response to stress directly influences the immune system by release of:
Hypothalamic peptides
Pituitary peptides
ACTH (stimulates release of cortisol)
Endorphins
Norepinephrine
Growth hormone |
|
|
Term
| By innervations in which organs does the nervous system mediate stress on the immune system? |
|
Definition
By innervation of the following organs, the nervous system mediates the effects of stress.
Thymus
Spleen
Lymph Nodes
Bone marrow |
|
|
Term
| Cancer is not a single disease, but rather is a family of diseases in which affected cells share certain properties. What are these properties? |
|
Definition
The properties shared by all cancer cells are:
Cells that reproduce in defiance of normal restraints
Cells that invade and colonize territories normally reserved for other cell types |
|
|
Term
|
Definition
| Neoplasia, or cancer, is the development of an abnormal type of growth that is unresponsive to normal growth control mechanisms |
|
|
Term
|
Definition
A neoplasm, or tumor, is a group or clump of neoplastic cells.
A neoplasm (tumor) is a manifestation of neoplasia (cancer) |
|
|
Term
| What is benign neoplasia? |
|
Definition
| Benign neoplasia: neoplastic cells that do not invade the surrounding tissue or slough off cells from the neoplasm |
|
|
Term
| What is the largest tumor ever removed intact? |
|
Definition
| The largest tumor ever removed was a multicystic mass of the right ovary weighing 137.6 kg (303 lb) with a diameter of 1 meter |
|
|
Term
| What is malignant neoplasia? |
|
Definition
| Malignant neoplasia: neoplastic cells that grow by invading surrounding tissue and metastasize to receptive tissues. |
|
|
Term
|
Definition
| Metastasis is the ability of cancer cells to disseminate and establish growth in another part of the body than where it originated. |
|
|
Term
| If a person in the United States is diagnosed with liver cancer, caregivers immediately search the body for another neoplasm. Why? |
|
Definition
| In the United States, it is rare for liver cancer to develop as a primary tumor. Therefore, liver cancer has most likely metastasized to the liver from another location in the body. |
|
|
Term
| How is neoplasia classified? |
|
Definition
| Neoplasia is classified based on the tumor cell origin and whether it is benign or malignant. (Origin b/m) |
|
|
Term
|
Definition
A carcinoma is malignant tumor.
Cells are of endothelial or epithelial origin. |
|
|
Term
|
Definition
A sarcoma is a malignant tumor.
It arises in connective tissues or muscle cells. |
|
|
Term
| What is an adenocarcinoma? |
|
Definition
Adenocarcinomas are malignant tumors.
They arise from glandular or ductal epithelium. |
|
|
Term
|
Definition
An adenoma is benign tumor.
It arises from glandular epithelium. |
|
|
Term
| What are the stages of tumorigenesis? |
|
Definition
The stages of tumorigenesis are as follows:
Initiation (insult to DNA)
Dedifferentiation (cells become more generalized)
Cell proliferation (uncontrolled increase in cell number)
Cell migration (metastasis) |
|
|
Term
|
Definition
| A promoter is a chemical that stimulates the rate of cell division in transformed (neoplastic) cells. |
|
|
Term
|
Definition
A carcinogen is a chemical that causes cancer.
A carcinogen is NOT a promoter. |
|
|
Term
|
Definition
Tumor markers are substances produced by cancer cells that are found on the tumor plasma membranes or in the blood, spinal fluid, or urine.
It may be used as the basis for a cancer test. |
|
|
Term
| Alpha-fetoprotein is a tumor marker. What type of cancer is it associated with? |
|
Definition
| The tumor marker alpha-fetoprotein is a tumor marker associated with hepatic or germ-cell cancers. |
|
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Term
| Beta-human chorionic gonadotropin is a tumor marker. What type of cancer is it associated with? |
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Definition
| Beta-human chorionic gonadotropin is a tumor marker associated with germ cell cancer. |
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Term
| Prostate-specific antigen (PSA) is a tumor marker. What type of cancer is it associated with? |
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Definition
| Prostate-specific antigen is a tumor marker associated with prostate cancer. |
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Term
| Adrenocorticotropic hormone (ACTH) is a tumor marker. What type of cancer is it associated with? |
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Definition
| ACTH is a tumor marker associated with pituitary adenomas. |
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Term
| How may cancer-causing mutations be caused? |
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Definition
All cancer is the result of DNA mutation. The mutation may be due to:
Spontaneous mutations (mistakes in DNA copy)
Exposure to mutagens or radiation
Exposure to cancer-inducing viruses |
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Term
| Not just any mutation causes cancer. Where must the mutation occur to cause cancer? |
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Definition
| The mutation must occur in a gene that codes for proteins involved in control of cell division. The three classes of genes that are frequently mutated in cancer are the: proto-oncogenes; tumor suppressor genes, and caretaker (mutator) genes |
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Term
| What is a proto-oncogene? |
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Definition
| A proto-oncogene codes for growth stimulatory factors, or proteins that tell cells to divide. If mutated, the gene becomes an oncogene. More active proteins are produced and/or activity is stimulated at inappropriate times. |
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Term
| What is a tumor suppressor gene? |
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Definition
| A tumor suppressor gene usually functions as an inhibitor of cell proliferation. Mutations lead to a loss of their inhibitory function. |
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Term
| What mutation is found in 50-55% of all cancers? |
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Definition
| In 50-55% of all cancers, p53 is mutated. |
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Term
| What percentage of people with a mutation in BRCA-1 or BRCA-2 will develop breast cancer? |
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Definition
| 27-44% of people with a mutation in BRCA-1 or BRCA-2 will develop breast cancer. |
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Term
| What percentage of people without a mutated BRCA-1 or BRCA-2 will develop breast cancer? |
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Definition
| Without a mutation in either BRCA-1 or BRCA-2, only 2% of people with develop breast cancer. |
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Term
| What are mutator (caretaker) genes? |
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Definition
| Caretaker genes usually function to ensure fidelity of replication and maintenance of genome integrity. Loss of function (due to a mutation) makes the cell prone to accumulating errors. |
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Term
| What are some familial types of cancer? |
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Definition
Some familial forms of cancer are:
retinoblastoma
neurofibromatosis
inherited breast cancer (BRCA-1,2)
Adenoma of the colon |
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Term
| How may ionizing radiation be a causative factor of cancer? |
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Definition
| Ionizing radiation (includes X-rays, UV, gamma, and cosmic rays) damages DNA. If the damage occurs in a proto-oncogene or a tumor suppressor gene, cancer may result. |
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Term
| How may viruses be causative factors of cancer? |
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Definition
Viruses incorporate themselves into the DNA of their host cell. They insert their genetic information nonspecifically, and may damage a proto-oncogene or tumor suppressor gene in doing so.
Examples of cancers caused by viruses include:
Human T-cell leukemia (HTLV I and II)
Human papilloma virus (HPV)
Hepatitis B and C |
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Term
| How may chemicals be causative factors of cancer? |
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Definition
| A chemical may damage DNA in the region of a proto-oncogene or tumor suppressor. |
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Term
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Definition
A mutagen is a chemical that causes changes to DNA structure.
All carcinogens are mutagens; not all mutagens are carcinogens. |
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Term
| What are some environmental risk factors for cancer? |
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Definition
Radiation
Carcinogens
Diet
Sexuality
Habits
Hormones
Drugs/Medicines |
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Term
| How may diet be a risk factor for cancer? |
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Definition
Diets that are high-fat, low-fiber have been shown to increase the risk of colon and breast cancer.
Food preservatives contain nitrites, which the body converts into nitrosamines, which are carcinogenic.
In high concentrations, antioxidants (ascorbic acid, vitamin E) can promote free radical formation. |
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Term
| How may sexuality be a risk factor for cancer? |
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Definition
| Cervical cancer is related to sexual activity. The more partners a woman has, the more likely she is to be infected with the human papilloma virus, which may result in cervical cancer. |
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Term
| Some habits can be risk factors for cancer. Tobacco, alcohol, and sun are examples. What cancers are related to these? |
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Definition
Tobacco: lung and throat cancer
Alcohol: colon and liver cancer
Sun (UV): skin cancer |
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Term
| Does birth control (or hormone therapy) increase cancer occurrence? |
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Definition
Birth control pills use a combination of estrogen and progesterone to mimic pregnancy. There have been some concerns that the hormones could increase cancer risk.
Breast cancer: weak effect, if any (possibly more likely in certain subgroups)
Ovarian cancer: may actually provide protection
Cervical cancer: may increase risk |
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Term
| Is diethylstilbesterol (DES) an environmental risk for cancer? |
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Definition
DES is a drug that was given to pregnant women from 1938-1971 to help sustain pregnancies.
In the actual recipients of DES, no negative side effects were seen. However, their children had a higher likelihood of developing vaginal/testicular cancer. |
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Term
| What is X-linked agammaglobulinemia? |
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Definition
X-linked agammaglobulinemia is a defect in the maturation of stem cells into B cells.
It results in reduced antibody production and extreme susceptibility to bacterial infections. It is congenital. |
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Term
| What may cause acquired IgA deficiency? |
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Definition
Acquired IgA deficiency may be caused by exposure to:
Phenytoin--an anticonvulsant
Penicillamine--a metal chelator |
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Term
| What are the symptoms of IgA deficiency? |
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Definition
The symptoms of IgA deficiency are:
Problems associated with mucosal secretions (infections of sinuses and the respiratory tract; GI problems)
Autoimmune diseases
Increased frequency of cancer |
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Term
| What is DiGeorge Syndrome? |
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Definition
In DiGeorge Syndrome, there is a deficiency in T cells but not in B cells. It i s thought to be caused by environmental agents or drugs prior to the 8th week of gestation.
Hypoplasia or aplasia of the thymus is seen.
Allografts are not rejected and there is no reaction to skin test antigens.
Little or no resistance to viruses, fungi, or gram-negative bacteria |
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Term
| What are complement abnormalities associated with? |
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Definition
Complement abnormalities are associated with:
Autoimmune disease
Allergic reactions
Difficulty in clearing gram-negative bactera |
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Term
| What are immunosuppressive drugs used for? |
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Definition
Immunosuppressive drugs are used to decrease the rejection phenomenon in transplanted tissue, the rate of growth of malignant tumors, and inflammation associated with autoimmune disorders
Cause secondary immune deficiency |
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