Acute myocardial infarction (heart attack)
(AMI):
Caused by occlusive thrombosis of a coronary artery, precipitated
by fissure ("cracking") of an atheromatous plaque in the
vessel wall. Interruption of blood flow to a portion of the heart
muscle causes ischemia and necrosis of cardiomyocytes which may
lead to pump failure and death unless blood flow is restored within
a few hours of symptom onset.
Amino acids:
A class of 20 molecules that form the building blocks of proteins
(or polypeptides). Their structure contains a basic amino (NH2)
group, an acidic carboxyl (COOH) group and a side chain (R —
which stands for the 20 different side chains) attached to the alpha
carbon atom. The different amino acids can be represented by three
letters or by one letter symbols (e.g. lysine= Lys= K). The sequence
of amino acids in a protein and hence protein function is determined
by the nucleotide sequence in the genes.
Angina pectoris:
Chest pain, usually caused by "myocardial ischemia," a
low supply of oxygen to the heart muscle due to reduced blood supply
resulting from hardening and narrowing of the coronary arteries.
Angioplasty:
A technique to open up narrowed or blocked coronary arteries with
a balloon catheter.
Angiogram:
A radiograph of blood vessels taken during angiography.
Antibody:
A protein, produced by a B lymphocyte, that recognizes a foreign
antigen and binds to it. It is usually composed of two light and
two heavy chains and has a molecular weight of approximately 150,000.
Anticoagulant:
An agent that slows the blood clotting process.
Antigen:
A molecule that binds to an antibody. An antigenic determinant or
epitope is the region of a molecule that binds to the antibody.
Antiplatelet:
A substance that acts on blood platelets, thereby inhibiting their
function in blood coagulation. Platelets play a pivotal role in
atherosclerosis and thrombosis.
Antithrombotics:
Drugs that reduce blood coagulation (anticoagulants) or platelet
activation (antiplatelet agents).
Arterial thrombosis:
A blood clot that blocks an artery, usually due to atherosclerotic
damage of the wall of the artery.
Atherosclerosis:
A cardiovascular disease in which plaques containing fatty substances,
such as cholesterol, are formed within the inner layers of the arteries.
It is a progressive condition occurring over decades, primarily
affecting the arteries of the heart, brain and extremities. Its
complications include heart attack, stroke or peripheral arterial
occlusion.
Biodegradable:
Denoting a substance that can be chemically degraded or decomposed
by natural effectors (e.g., weather, soil bacteria, plants, animals).
Blood platelets:
Particulate non-nucleated elements in the blood, which play a crucial
role in hemostasis.
Cardiovascular:
Relating to the heart and blood vessels.
Catheter-delivered:
Administration via a tube which is introduced into a blood vessel
and advanced into the vicinity of a thrombus.
Central venous catheter (CVC):
A CVC is an intravenous line that is placed into a large vein in
patients who require regular injections or medication.
Clearance:
Removal of a substance from the blood.
Clinical trials/evaluation of the potential
of a drug for clinical use:
Phase I – Safety studies
and pharmacological profiling–This phase determines the drug’s
pharmacological actions, its safe dosage range, how it is absorbed,
distributed, metabolized and excreted, and the duration of its action.
These tests involve a small number of patients or healthy volunteers.
Phase II – Dose-finding and efficacy
studies–This phase of the clinical development consists of
controlled studies in volunteer patients to assess a drug’s
effectiveness.
Phase III – Randomized clinical trials
in humans–Here the testing moves to larger numbers of volunteer
patients. The drug is administered by practicing physicians to those
suffering from the condition the drug is intended to treat. These
studies must confirm earlier efficacy studies and identify a low-incidence
of adverse reactions.
Phase IV – Post marketing
studies–Studies are conducted after approval, during general
use of the drug by medical practitioners.
Coronary arteries:
The arteries around the heart which supply the heart muscle with
blood.
Coronary artery disease:
Narrowing of the coronary arteries. When they occlude by formation
of a blood clot, the heart becomes severely damaged.
Coronary artery recanalization:
Restoration of a lumen in the coronary artery following thrombotic
or atherosclerotic occlusion.
Deep vein thrombosis (DVT):
Blood clotting within the deep-lying veins, most often in the legs or pelvis.
Endocrine:
Secreting internally (as opposed to exocrine), applied to organs
and structures that release their products into the blood or lymph,
and to substances (hormones) that exert specific effects on other
organs. Called also endosecretory.
Gene:
The fundamental functional unit of heredity, which carries information
from one generation to the next. A gene is an ordered sequence of
nucleotides located in a position on a particular chromosome that
encodes a specific product (i.e., a protein or RNA molecule).
Genotype:
The genetic constitution of an organism. With respect to single
genes the organism may be wild type (two normal genes), heterozygous
(one normal and one abnormal allele) or homozygous (two abnormal
alleles).
Heart attack (acute myocardial infarction):
Necrosis of part of the heart muscle (myocardium) as a result of
blood and oxygen deprivation. Heart attacks usually occur because
the coronary arteries become clogged by a blood clot.
Hemostasis:
The arrest of bleeding from an injured blood vessel, requires the
combined regulated activity of vascular, platelet, and plasma factors.
Hemostatic abnormalities can lead to excessive bleeding or thrombosis.
Heparin:
A large polysaccharide molecule, originally derived from bovine
lung or porcine intestine, which blocks the formation of blood clots
(acts as an anticoagulant) by activating antithrombin III. The polysaccharide
is composed of D-glucosamine-2,6-disulfate and D-glucuronic acid-2-sulfate,
and is used for prevention and treatment of acute thrombosis.
Hormone:
A chemical substance, formed in one organ or part of the body and
carried in the blood to another organ or part; depending on the
specificity of their effects, hormones can alter the functional
activity, and sometimes the structure, of just one organ or tissue
or various numbers of them. A number of hormones are formed by ductless
glands, but secretin, cholecystokinin, and pancreozymin, formed
in the gastrointestinal tract, by definition are also hormones.
Indication:
The basis for initiation of a treatment for a disease or of a diagnostic
test; may be furnished by a knowledge of the cause (causal indication),
by the symptoms present (symptomatic indication), or by the nature
of the disease (specific indication).
Intravenous:
Administration by direct injection into a vein.
Ischemia:
Lack of oxygen which may lead to cell death.
Liposome:
A spherical particle of lipid substance suspended in an aqueous
medium within a tissue, or any small, roughly spherical artificial
vesicle consisting of a lipid bilayer enclosing some of the suspending
medium.
Lyophilized:
To freeze-dry (blood plasma or other biological substances).
Morbidity:
The impact of a disease on health.
Mortality:
The impact of a disease on life.
Mutation:
The process producing a gene differing from the wild type.
Myocardial infarction:
Heart attack.
Nutraceutical:
A food or part of a food that may provide medicinal or health benefits,
including the prevention and treatment of disease. A nutraceutical
may be a naturally nutrient-rich or medicinally active food, such
as garlic or soybeans, or it may be a specific component of a food,
such as the omega-3 fish oil that can be derived from salmon and
other cold-water fish.
Occlusive vascular disease:
Peripheral vascular occlusive disease includes two main categories:
those patients with claudication or cramping of muscle groups with
activity that is alleviated by rest and those individuals who have
a threatened extremity as evidenced by rest pain, non-healing ulcers
or tissue gangrene.
Peripheral arterial disease (PAD) also
called peripheral arterial occlusion disease (PAOD):
Thrombosis in the peripheral arteries is the most common cause of
obstruction of the blood flow to the lower limbs. It is an acute
complication of atherosclerosis.
Phospholipid:
A lipid containing phosphorus, thus including the lecithins and
other phosphatidyl derivatives, sphingomyelin, and plasmalogens;
the basic constituents of biomembranes.
Platelet:
Blood corpuscle. The aggregation of platelets leads to a clot.
Prothrombotic:
Predisposing to thrombosis.
Prostaglandin:
Any of a class of physiologically active substances present in many
tissues, with effects such as vasodilation, vasoconstriction, stimulation
of intestinal or bronchial smooth muscle, uterine stimulation, and
antagonism to hormones influencing lipid metabolism. Prostaglandins
are prostanoic acids with side chains of varying degrees of unsaturation
and varying degrees of oxidation. Often abbreviated PGA, PGB, PGC,
PGD, etc. with numeric subscripts, according to structure.
Prostaglandin E-1:
A potent hormone-like substance that can control blood pressure,
muscle contractions, and inflammation. Letters (and numbers) are
added to designate the type, e.g., prostaglandin E-1 is a relaxant
(vasodilator).
Randomized:
Assigned by chance to a particular group or treatment.
Restenosis:
The narrowing of an arterial lumen following its enlargement.
Saline:
Relating to salt. As an adjective, "saline" means "salty,
containing salt." As a noun "saline" is a salt solution,
often adjusted to the normal salinity of the human body. Salt, in
medicine, is referring to sodium chloride. Sodium chloride is common
table salt and the salt concentrated in the earth and in seawater.
Certain concentrations of both sodium and chloride in the blood
are essential for normal body functions. Saline solutions are commonly
used in medicine as fluid replacements to treat or prevent dehydration.
Severe intermittent claudication:
Intermittent claudication is leg pain (most often in the calves)
that does not clear up after walking and is relieved by rest. In
severe cases even rest offers no benefit and pain can continue even
when lying down. Intermittent claudication is a symptom of peripheral
artery disease (PAD), also called PAOD.
Stem Cell:
A stem cell is a "generic" cell that can make exact copies
of itself indefinitely. In addition, a stem cell has the ability
to produce specialized cells for various tissues in the body --
such as heart muscle, brain tissue, and liver tissue. Scientists
are able to maintain stem cells forever, developing them into specialized
cells as needed.
There are two basic types:
Embryonic stem cells:
These are obtained from either aborted fetuses or fertilized eggs
that are left over from in vitro fertilization (IVF). They are useful
for medical and research purposes because they can produce cells
for almost every tissue in the body.
Adult stem cells:
These are not as versatile for research purposes because they are
specific to certain cell types, such as blood, intestines, skin,
and muscle. The term "adult stem cell" may be misleading
because both children and adults have them.
Stent:
A thread, rod, or catheter, lying within the lumen of tubular structures,
used to provide support during or after their anastomosis, or to
assure patency of an intact but contracted lumen, or the process
of placing a stent. Device used to maintain a bodily orifice or
cavity during skin grafting. To immobilize a skin graft after placement.
Stroke:
A blood clot, usually caused by atherosclerosis, obstructs a major
blood vessel of the brain. It results in death or serious brain
damage, such as paralysis.
Subcutaneous:
Administration by injection under the skin.
Therapeutic index:
Originally, the ratio of the maximum tolerated dose to the minimum
curative dose; now defined, so as to account for variability of
individual response, as the ratio of the median lethal dose (LD50)
to the median effective dose (ED50). It is used in assessing the
safety of a drug.
Thrombolytic agent:
A drug that acts on a blood clot (thrombus) to dissolve this clot
and reopen the blood vessel.
Thrombolytic therapy:
Treatment of thrombosis by infusing thrombolytic agents.
Thrombosis:
The formation of a blood clot that blocks a blood vessel.
Thrombo-embolic disease (thrombotic disease):
Diseases caused by occlusion of blood vessels (includes heart attack,
stroke, peripheral arterial occlusion, deep vein thrombosis, pulmonary
embolism, etc.)
Toxicology:
The various tests conducted to determine the relative toxicity of
a compound to living systems.
Vascular:
Relating to or containing blood vessels.
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