in drug research, the ability of a drug to
produce a desired clinical effect, such as protection against a
specific infection, at the optimal dosage and schedule in a given
population. A drug may be tested for efficacy in Phase
3 trials if it appears to be safe and shows some promise in
smaller Phase 1 and Phase
2 trials.
a blood test that detects antibodies to viruses
(eg, HIV) or bacteria(eg, Helicobacter pylori ) based on a
reaction that leads to a detectable color change in the test tube.
The HIV ELISA is commonly used as the initial screening test because
it is relatively easy and inexpensive to perform. Because the HIV
ELISA is designed for optimal sensitivity -- that is, it detects all
persons with HIV antibodies as well as some who don’t have them
(false positives) -- a positive HIV ELISA test must be confirmed by
a second, more specific test such as an HIV Western Blot.
Embolism (EM-buh-liz-em)
the sudden blocking of an artery by a clot or
foreign material that has been brought to the site by the blood
flow.
Embolus (EM-buh-lus)
a mass of clotted blood or other material
brought by the blood from another vessel and forced into a smaller
one, thus obstructing the circulation.
based on experience or observational
information and not necessarily on proven scientific data. In the
past, vaccine trials have been performed based exclusively on
empirical data and without a full understanding of the disease
processes or correlates of immunity.
a suspension of droplets of one liquid in
another liquid (such as oil and water). The two liquids do not
actually combine but are instead suspended within one another.
Encopresis (en-koh-PREE-sis)
Accidental passage of a bowel movement. A
common disorder in children.
Endocrine glands
Glands that release hormones into the
bloodstream. They affect how the body uses food (metabolism). They
also influence other body functions. One endocrine gland is the
pancreas. It releases insulin so the body can use sugar for energy.
See also: Gland.
Endocrinologist
A doctor who treats people who have problems
with their endocrine glands. Diabetes is an endocrine disorder. See
also: Endocrine glands.
Endogenous
Grown or made inside the body. Insulin made by
a person's own pancreas is endogenous insulin. Insulin that is made
from beef or pork pancreas or derived from bacteria is exogenous
because it comes from outside the body and must be injected.
Naturally occurring painkilling chemicals.
Substances produced in the brain or nervous system that stops pain
naturally.
Some scientists theorize that people who
suffer from severe headache have lower levels of endorphins than
people who are generally pain free.
Endoscope (EN-doh-skohp)
A small, flexible tube with a light and a lens
on the end. It is used to look into the esophagus, stomach,
duodenum, colon, or rectum. It can also be used to take tissue from
the body for testing or to take color photographs of the inside of
the body. Colonoscopes and sigmoidoscopes are types of endoscopes.
A test using an x-ray to look into the bile and
pancreatic ducts. The doctor inserts an endoscope through the mouth
into the duodenum and bile ducts. Dye is sent through the tube into
the ducts. The dye makes the ducts show up on an x-ray.
An operation to cut the muscle between the
common bile duct and the pancreatic duct. The operation uses a
catheter and a wire to remove gallstones or other blockages. Also
called endoscopic papillotomy.
Endoscopy (en-DAW-skuh-pee)
A procedure that uses an endoscope
to diagnose or treat a condition.
Endpoint
the results of an intervention such as
vaccination compared among different study groups in a clinical
trial. In early vaccine trials, common endpoints are safety and
specific types and intensities of immune responses (neutralizing
antibodies, CTL responses).
Enhancing antibody
a type of binding antibody, detected in the
test tube and formed in response to viral (eg, HIV) infection, that
may enhance the ability of the virus to produce disease.
Theoretically, enhancing antibodies could attach to virions and
enable macrophages to engulf the viruses. However, instead of being
destroyed, the engulfed virus may remain alive within the
macrophage, which then can carry the virus to other parts of the
body.It is currently unknown whether enhancing antibodies
have any effect on the course of HIV infection. Enhancing antibodies
can be thought of as the opposite of neutralizing
antibodies.
Enema (EN-uh-muh)
A liquid put into the rectum to clear out the
bowel or to administer drugs or food.
Enteral Nutrition (EN-tuh-rul noo-TRISH-un)
A way to provide food through a tube placed in
the nose, the stomach, or the small intestine. A tube in the nose is
called a nasogastric or nasoenteral tube. A tube that goes through
the skin into the stomach is called a gastrostomy or percutaneous
endoscopic gastrostomy (PEG). A tube into the small intestine is
called a jejunostomy or percutaneous endoscopic jejunostomy (PEJ)
tube. Also called tube feeding. See also Gastrostomy
and Jejunostomy.
Enteritis (en-tuh-RY-tis)
An irritation of the small intestine.
Enterocele (EN-tuh-roh-seel)
A hernia in the intestine.
Enteroscopy (en-tuh-RAW-skuh-pee)
An examination of the small intestine with an
endoscope. The endoscope is inserted through the mouth and stomach
into the small intestine.
Enterostomy (en-tuh-RAW-stuh-mee)
An ostomy, or opening, into the intestine
through the abdominal wall.
a protein catalyst that speeds chemical
reactions in living organisms (see catalyze.
a protein produced by cells to accelerate a
specific chemical reaction without itself being altered. Enzymes are
generally named by adding the ending "-ase" to the name of
the substance on which the enzyme acts (for example, protease is an
enzyme that acts on proteins).
Many enzymes require the presence of an additional, nonprotein, cofactor.
Some of these are metal ions such as Zn2+
(the cofactor for carbonic anhydrase), Cu2+, Mn2+,
K+, and Na+.
Some cofactors are small organic molecules
called coenzymes. The B vitamins thiamine (B1), riboflavin
(B2) and nicotinamide are precursors of coenzymes.
Infection and swelling of the lining of the
stomach, small intestine, or large intestine. The infection is
caused by white blood cells (eosinophils).
Epidemiology
The study of a disease that deals with how many
people have it, where they are, how many new cases develop, and how
to control the disease.
Epinephrine
One of the secretions of the adrenal glands. It
helps the liver release glucose (sugar) and limit the release of
insulin. It also makes the heart beat faster and can raise blood
pressure; also called adrenalin.
Epithelial Cells (eh-puh-THEE-lee-ul selz)
One of many kinds of cells that form the
epithelium and absorb nutrients. See also Epithelium.
Red swellings or sores on the lower legs during
flareups of Crohn's disease
and ulcerative colitis. These sores show that the disease is active.
They usually go away when the disease is treated. For detailed
informtion on Crohn's disease click here.
Escherichia coli(eh-shuh-RIK-ee-uh KOH-ly)
Bacteria that cause infection and irritation of
the large intestine. The bacteria are spread by unclean water, dirty
cooking utensils, or undercooked meat. See also Gastroenteritis.
Exam of the upper digestive tract using an
endoscope. See Endoscopy.
Esophagus (eh-SAW-fuh-gus)
The organ that connects the mouth to the
stomach. Also called gullet.
Essential
Describes a substance that the body requires which must be
obtained through diet, since the body cannot independently produce it.
Many fatty acids, amino acids, minerals, and vitamins are essential.
