of unknown cause.
a surgically created connection between the ileum (part of the small intestine) and an opening in the abdominal wall (stoma) that allows for the evacuation of feces when a portion of the bowel has been removed.
Impaired glucose tolerance
a metabolic state between normal glucose regulation and overt diabetes. Impaired glucose tolerance is defined medically as a plasma glucose concentration between 140 and 199 mg/dL (7.8-11.0 mmol) two hours after the ingestion of 75 g of glucose during an oral glucose tolerance test.
inability to control the evacuation of urine or feces.
initiation of or increase in the expression of a gene in response to a physical or chemical stimulus (inducer).
a response to injury or infection, characterized by redness, heat, swelling, and pain. Physiologically, the inflammatory response involves a complex series of events, leading to the migration of white blood cells to the inflamed area.
Inflammatory bowel disease
a group of autoimmune diseases that affect the small and large intestines.
not dissolvable. With respect to bioavailability, certain substances form insoluble complexes that cannot be dissolved in digestive secretions, and therefore cannot be absorbed by the digestive tract.
a peptide hormone secreted by the ß-cells of the pancreas required for normal glucose metabolism.
diminished responsiveness to insulin.
the ability of tissues to respond to insulin.
a condition characterized by leg pain or weakness on walking that diminishes or resolves with rest. It is usually associated with peripheral arterial disease.
International normalized ratio (INR)
the preferred method for reporting prothrombin time, a measure of coagulation status that may be used to evaluate the therapeutic efficacy of anticoagulants, such as warfarin. The INR is a method for standardizing prothrombin time results so as to minimize variability between laboratories.
an experimental study (usually a clinical trial) used to test the effect of a treatment or intervention on a health- or disease-related outcome.
the collection of microbial species that live specifically in the lower gastrointestinal tract (colon).
Intracellular fluid (ICF)
the volume of fluid inside cells.
within a vein.
a relationship between two variables in which they move in opposite directions.
literally “in glass,” referring to a test or research done in the test tube, outside a living organism.
“inside a living organism.” An in vivo assay evaluates a biological process occurring inside the body.
an atom or group of atoms that carries a positive or negative electric charge as a result of having lost or gained one or more electrons.
a protein embedded in a cell membrane that serves as a crossing point for the regulated transfer of an ion or a group of ions across the membrane.
a state of insufficient blood flow to a tissue.
a stroke resulting from insufficient blood flow to an area of the brain, which may occur when a blood vessel supplying the brain becomes obstructed by a clot.
one of two or more compounds that has the same number and kind of atoms but differs in the way the atoms are arranged.
a different form of the same chemical element. Isotopes have the same number of protons but different numbers of neutrons.
a yellowish staining of the skin and whites of the eyes due to increased bilirubin (a bile pigment) levels in the blood. Jaundice can be an indicator of red blood cells rupturing (hemolysis), or disease of the liver or gallbladder.
the process of cell differentiation of a keratinocyte through the different layers of the epidermis. At the end of keratinization, the cell is wider and flatter and attached to its neighboring cells by a variety of protein and lipid attachments.
primary cell type of the epidermis; these cells produce the structural protein keratin, which comprise the epidermal barrier.
any of three acidic chemicals (acetate, acetoacetate, and ß-hydroxybutyrate). Ketone bodies may accumulate in the blood (ketosis) when the body has inadequate glucose to use for energy and must increase the use of fat for fuel. Ketone bodies are acidic, and very high levels in the blood are toxic and may result in ketoacidosis.
solid masses resulting from the crystallization of minerals and other compounds found in urine. Common types of kidney stones include those composed of calcium oxalate, calcium phosphate and urate. Kidney stones may form in the kidneys, ureters, or urinary bladder.
an antigen-presenting cell involved in epidermal immunity.
the area of the throat (pharynx) that contains the vocal cords.
low-density lipoprotein. LDLs transport cholesterol from the liver to the tissues of the body. Elevated serum LDL-cholesterol is associated with increased cardiovascular disease risk.
Left ventricular hypertrophy (LVH)
abnormal thickening of the wall of the left ventricle (lower chamber) of the heart muscle. The ventricles have muscular walls in order to pump blood from the heart through the arteries, but LVH occurs when the ventricle must pump against abnormally high volume or pressure loads. LVH may accompany congestive heart failure (CHF).
members of the large family of plants known as leguminosae. In this context the term refers to the fruit or seeds of leguminous plants (e.g., peas and beans) that are used for food.
the transparent structure inside the eye that focuses light rays onto the retina (the nerve cells at the back of the eye).
hormone secreted by adipose tissue that helps to regulate of food intake, body weight, and energy homeostasis.
resistance to the action of leptin.
an acute or chronic form of cancer that involves the blood-forming organs. Leukemia is characterized by an abnormal increase in the number of white blood cells in the tissues of the body, with or without a corresponding increase of those in the circulating blood, and is classified according to the type of white blood cell most prominently involved.
white blood cell. Leukocytes are part of the immune system. Monocytes, lymphocytes, neutrophils, basophils, and eosinophils are different types of leukocytes.
cell-signaling molecule involved in inflammation. Lipoxygenases catalyze the formation of leukotrienes from eicosanoids, such as arachidonic acid and eicosapentaenoic acid (EPA).
a substance that binds to another molecule, forming a complex.
the process by which lipids are oxidatively modified; so named because lipid hydroperoxides are formed in the process.
a chemical term for fat. Lipids found in the human body include fatty acids, phospholipids, and triglycerides.
the production of fatty acids.
a cofactor, essential for the oxidation of a-keto acids, such as pyruvate, in metabolism.
a lipoprotein particle in which the protein (apolipoprotein B-100) is chemically linked to another protein apolipoprotein(a). Increased blood levels of Lp(a) are associated with an increased risk of cardiovascular disease.
particle composed of lipids and protein that allows for the transport of lipids through the bloodstream. A lipoprotein particle is composed of an outer layer of phospholipids, which renders it soluble in water, and a hydrophobic core that contains triglycerides and cholesterol esters. Different types of lipoproteins are distinguished by their surface proteins (apoproteins), their size, and the types and amounts of lipids they contain.
the portion of the spine between the chest (thorax) and the pelvis. It is commonly referred to as the small of the back.
the channel within a tube such as a blood vessel or the intestine.
see systemic lupus erythematosus (SLE).
leukocyte (white blood cells) that plays important roles in the immune system. T lymphocytes (T cells) differentiate into cells that can kill infected cells or activate other cells in the immune system. B lymphocytes (B cells) differentiate into cells that produce antibodies.
a cellular organelle containing hydrolytic enzymes specialized for breaking down cellular debris. Lysosomal enzymes are separated from the rest of the cell by a lysosomal membrane and function optimally at an acidic pH.
low red blood cell count, characterized by the presence in the blood of larger than normal red blood cells.
nutrients required in relatively large amounts; macronutrients include carbohydrates, proteins, and lipids.
white blood cell that engulfs and degrades pathogens (bacteria) and cellular debris. Macrophages are activated or transformed monocytes.
a small area of the retina where vision is the sharpest. The macula is located in the center of the retina and provides central vision.
Magnetic Resonance Imaging (MRI)
a special imaging technique that uses a powerful magnet and a computer to provide clear images of soft tissues. Tissues that are well-visualized using MRI include the brain and spinal cord, abdomen, and joints.
a disease or condition that results in poor absorption of nutrients from food.
an infectious disease caused by parasitic microorganisms called plasmodia. Malaria can be spread among humans through the sting of certain types of mosquitos (Anopheles) or by a contaminated needle or transfusion. Malaria is a major health problem in the tropics and subtropics, affecting over 200 million people worldwide.
Matrix metalloproteinase (MMP)
a proteolytic enzyme that degrades extracellular matrix proteins, such as collagen and elastin.
membranous or microfold cells; specialized cells in the intestinal epithelium that internalize pathogenic microorganisms to the gut-associated lymphoid tissue.
the difference between a measured value and its true value.
low red blood cell count, characterized by the presence in the blood of large, immature, nucleated cells (megaloblasts) that are forerunners of red blood cells. Red blood cells, when mature, have no nucleus.
a dark brown pigment found in the skin.
a pigment-containing cell of the epidermis. The pigment, melanin, absorbs ultraviolet light and protects the skin from damage. Unlike keratinocytes, melanocytes are not shed over time.
the electrical potential difference across a membrane. The membrane potential is a result of the concentration differences between potassium and sodium across cell membranes, which are maintained by ion pumps. A large proportion of the body’s resting energy expenditure is devoted to maintaining the membrane potential, which is critical for nerve impulse transmission, muscle contraction, heart function, and the transport of nutrients and metabolites in and out of cells.
the first occurrence of menstruation.
the cyclic loss of blood by a woman from her uterus (womb) when she is not pregnant. Menstruation generally occurs every four weeks after a woman has reached sexual maturity and prior to menopause.
a statistical technique used to combine the results from different studies to obtain a quantitative estimate of the overall effect of a particular intervention or exposure on a defined outcome.
a combination of medical conditions that places one at risk for cardiovascular disease and type 2 diabetes. (Metabolic syndrome is also called metabolic syndrome X, syndrome X, and insulin resistance syndrome.) Diagnostic criteria include the presence of three or more of the following conditions:
Abdominal obesity (waist circumference: =40 inches [102 cm] for men, =35 inches [88 cm] for women)
Elevated triglycerides (=150 mg/dL)
High blood pressure (=130/85 mmHg)
Glucose intolerance/insulin resistance (fasting blood glucose =110 mg/dL)
Decreased HDL cholesterol (<40 mg/dL for men, <50 mg/dL for women)
the sum of the processes (reactions) by which a substance is assimilated and incorporated into the body or detoxified and excreted from the body.
a compound derived from the metabolism of another compound is said to be a metabolite of that compound.
to spread from one part of the body to another. Cancer is said to metastasize when it spreads from the primary site of origin to a distant anatomical site.
a sulfur containing amino acid, required for protein synthesis and other vital metabolic processes. It can be obtained through the diet in protein or synthesized from homocysteine.
a biochemical reaction resulting in the addition of a methyl group (-CH3) to another molecule.
an aggregate or cluster of amphipathic molecules in water. Amphipathic molecules have a polar or hydrophilic end and a nonpolar or hydrophobic end. In micelles, amphipathic molecules orient with their hydrophobic ends in the interior and their hydrophilic ends on the exterior surface, exposed to water.
a nutrient required by the body in small amounts, such as a vitamin or a mineral.
small non-coding RNA involved in the regulation of gene expression.
a type of headache thought to be related to abnormal sensitivity of blood vessels (arteries) in the brain to various triggers resulting in rapid changes in the artery size due to spasm (constriction). Other arteries in the brain and scalp then open (dilate), and throbbing pain is perceived in the head. The tendency toward migraine appears to involve serotonin, a neurotransmitter that can trigger the release of vasoactive substances in the blood vessels.
nutritionally significant element. Elements are composed of only one kind of atom. Minerals are inorganic, i.e., they do not contain carbon as do vitamins and other organic compounds.
Minimal Erythemal Dose (MED)
the lowest dose of ultraviolet radiation (UVR) that will produce a detectable erythema 24 hours after UVR exposure.
energy-producing structures within cells. Mitochondria possess two sets of membranes: a smooth continuous outer membrane and an inner membrane arranged in folds. Among other critical functions, mitochondria convert nutrients into energy via the electron transport chain.
the process of cell division.
millimeters of mercury. The unit of measure for blood pressure.
a portion of something, such as a functional group of a molecule.
the fundamental unit for measuring chemical compounds (abbreviated mol). One mole equals the molecular weight of a compound in grams. The number of molecules in a mole is equal to 6.02 x 1023 (Avogadro’s number).
a class of proteins that facilitates in the folding and assembly of other proteins.
white blood cell that is the precursor to a macrophage.
a molecule that can be chemically bound as a unit of a polymer.
the use of a single medication to treat a condition.
Monounsaturated fatty acid
a fatty acid with only one double bond between carbon atoms.
short for messenger ribonucleic acid (RNA). These molecules are the ‘message’ that encodes the proteins produced in cells. Increases or decreases in mRNA levels will alter protein production in cells.
a glycoprotein that lubricates and protects body surfaces.
relating to the mucous membranes of the skin.
refers to diseases or conditions that are the result of interactions between multiple genetic and environmental factors.
Multiple sclerosis (MS)
an autoimmune disorder in which the myelin sheaths of nerves in the brain and spinal cord are damaged, resulting in progressive neurological symptoms.
an agent that can induce mutation.
a change in a gene; in other words, a change in the sequence of base-pairs in the DNA that makes up a gene. Mutations in a gene may or may not result in an altered gene product.
the fatty substance that covers myelinated nerves. Myelin is a layered tissue surrounding the axons or nerve fibers. This sheath acts as a conduit in an electrical system, allowing rapid and efficient transmission of nerve impulses.
the formation of the myelin sheath around a nerve fiber.
derived from bone marrow.
Myocardial infarction (MI)
death (necrosis) of heart muscle tissue due to an interruption in its blood supply. Commonly known as a heart attack, an MI usually results from the obstruction of a coronary artery by a clot in people who have coronary atherosclerosis.
an inflammation of the heart muscle.
a heme-containing pigment in muscle cells that binds and stores oxygen.
any disease of muscle.