Definition of African American

African American: An American of black African descent. The term may also be written with a hyphen as African-American.
The term entered into usage largely starting in 1988, when the Rev. Jesse Jackson held a news conference to urge Americans to use it to refer to blacks. African American has largely supplanted black in health matters. For example, "Breast cancer tumors in African-American women are more aggressive than tumors in white women."
The term has been a subject of debate, in part because it is ambiguous. It might be limited to Africans who have immigrated to America or to people born to one African and one American parent. Some have argued that the term African American should refer only to the descendents of slaves brought from Africa to America.
From a scientific viewpoint, the term African-American makes absolutely no sense. Most genetic evidence now supports an African origin for all humans on earth. Thus, everyone living in the Americas today is, properly speaking, African American.

Definition of AFP (alpha-fetoprotein)

AFP (alpha-fetoprotein): AFP is a plasma protein
that is
normally produced by the fetus. It serves as the basis for some
valuable tests.
AFP is manufactured principally in the
fetus's liver and, also, in the fetal gastrointestinal (GI) tract and
the yolk sac, a structure temporarily present during embryonic
development.
The level of AFP is typically high in the fetus's blood. It goes
down in
the baby's blood after birth. And by a year of age, it is virtually
undetectable.
During pregnancy, AFP crosses the placenta from the fetal
circulation and appears in the mother's blood. The level of AFP in
the mother's blood (the maternal serum AFP) provides a screening test
for a number of disorders including:
Open neural tube defects (anencephaly and spina
bifida); and
Down syndrome (and other chromosome abnormalities).
The maternal serum AFP (MSAFP) tends to be:
High with open neural tube
defects such as anencephaly and spina bifida (meningomyelocele); and
Low with Down syndrome (trisomy 21, an extra chromosome number
21).
AFP production is essentially nil after a year of age. However,
it starts up again under the stimulus of some diseases in the
liver. It
may, for example, be produced by the liver in viral hepatitis and
cirrhosis of
the liver. AFP is also made by primary liver tumors
(hepatomas) and by germ
cell tumors (teratocarcinoma and embryonal cell carcinomas). A
person's
serum AFP level can therefore be used to help detect these conditions
and monitor their
treatment.

Definition of AFO (ankle-foot orthosis)

AFO (ankle-foot orthosis) : Ankle-foot orthosis.

Definition of Aflatoxin

Aflatoxin: A toxin produced by mold that can damage the liver and may lead to liver cancer. Aflatoxins cause cancer in some animals.
The fungi that produce aflatoxin grow on crops such as peanuts (especially) and wheat, corn, beans and rice. Aflatoxin is a problem particularly in undeveloped and developing countries.
Aflatoxin is a naturally occurring mycotoxin produced by two types of mold: Aspergillus flavus and Aspergillus parasiticus. Aspergillus flavus is common and widespread in nature and is most often found when certain grains are grown under stressful conditions such as drought. The mold occurs in soil, decaying vegetation, hay, and grains undergoing microbiological deterioration and invades all types of organic substrates whenever and wherever the conditions are favorable for its growth. Favorable conditions include high moisture content and high temperature. At least 13 different types of aflatoxin are produced in nature with aflatoxin B1 considered as the most toxic. While the presence of Aspergillus flavus does not always indicate harmful levels of aflatoxin it does mean that the potential for aflatoxin production is present.

Definition of AFIP

AFIP: The Armed Forces Institute of Pathology.

Definition of Affinity

Affinity: In immunology, the strength of binding interaction between antigen and antibody molecules.

Definition of Afferent nerve

Afferent nerve: A nerve that carries impulses toward the central nervous system (CNS). The opposite of an afferent nerve is an efferent nerve that carries impulses away from the CNS.