Chapter 17 Terms (Transplantation)

Question 1

Codominance

Answer 1

Genes are expressed whether present as a single copy (heterozygous or hemizygous) or two copies (homozygous)

Question 2

Orthotopic Grafts

Answer 2

With respect to location, tissues or organs that are placed in their normal anatomic location.

Question 3

Heterotopic Grafts

Answer 3

Grafts that are placed into a site other than their normal place

Question 4

Autografts

Answer 4

Those transferred from one part of an individual to another location on the same individual

Question 5

Syngeneic Grafts

Answer 5

Those transferred between individuals who are genetically identical or nearly so (eg, identical twins or members of imbred strain)

Question 6

Allogeneic Grafts (Allografts)

Answer 6

Transferred between two genetically disparate individuals of the same species (eg, brother & sister, paretn & child, or totally unrelated individuals)

Question 7

Xenogeneic Grafts (Xenografts)

Answer 7

Those exchanged between members of different species (eg, the placement of primate heart in to a human recipient)

Question 8

Laws of Transplantation

Answer 8

Originally established in experiment studies, particularly in mice, but are applicable to human transplantation as wel.

Question 9

Imbreeding

Answer 9

Accomplished by mating of closely related individuals

Question 10

Inbred Strains

Answer 10

When laboratory mice are subjected to borther-sister mating for 20 or more consecutive generations

Question 11

Congenic Strains

Answer 11

Permit comparisons among organisms that differ from one another by only a small chromosomal segment in common

Question 12

Direct Recognition

Answer 12

Can occur only when some of the MHC class I or II molecules on the donor cells are identical to those on the recipient

Question 13

Indirect Recognition

Answer 13

Occurs when recipient APCs process & present peptide fragments derived from the ingestion, processing, & presentation of cellular debris from donor cells - debris that contains the donor histocompatibilty antigens - & presents it to recipient T cells.

Question 14

Chronic Rejections

Answer 14

• (Slowest & Least Vigorous)
• Transplanted tissues or organs establish a vascular connection & proceed to function for weeks, months, & even years before signs of deterioration due to immune attack becomes evident

Question 15

Acute Rejection

Answer 15

• (Occur much sooner after the graft emplacement than do chronic rejections)
• Grafts establish vascular connections & function normally for a relatively short period (2-4 weeks) before first signs of rejection appear

Question 16

Hyperacute Rejection

Answer 16

• (Most rapid)
• They are initiated & completed within a few days of graft replacement, usually before the grafted tissue or organs can establish vascular connections

Question 17

Second Set Rejection

Answer 17

Attempts to repeat grafts that have previously been rejected usually result in an accelerated graft rejection.

Question 18

Specific Immune Tolerance

Answer 18

Involves a selective inhibiting of the responsiveness to a given antigen or set of antigens

Question 19

Immune Suppression (Immunosuppression)

Answer 19

Involves inhibiting general immune responsiveness without regard to the specificity

Question 20

Transfusion

Answer 20

The transplantation of blood

Question 21

ABO Antigen System

Answer 21

A set of carbohydrate structures on RBCs surfaces & even some endothelial & epithelial cells

Question 22

Natural Antibodies (Naturally Occuring Antibodies)

Answer 22

Recognize & bind A & B antigens

Question 23

Transfusion Reaction

Answer 23

Massive destruction of RBCs

Question 24

Rh (“Rhesus”) Antigens

Answer 24

• Proteins on RBC surfaces
• When an RH^- individual is exposed to Rh⁺ RBCs, he or she can generate antibodies, some of which are of the IgG isotype

Question 25

Hemolytic Disease of the Newborn (HDN)

Answer 25

• Also called Erythroblastosis Fetalis
• An alloimmune condition that develops in a fetus, when the IgG molecules produced by the mother pass through the placenta.
• Some of these antibodies attack the fetal RBCs

Question 26

Gaft-vs-Host Diseases (GVHD)

Answer 26

• Common complication following an allogeneic tissue transplant.
• Commonly associated with stem cell or bone marrow transplant.