a small organ located behind the stomach and connected to the duodenum (part of the small intestine). The pancreas synthesizes enzymes that help digest food in the small intestine and hormones, including insulin, that regulate blood glucose levels.
the uppermost layer of the dermis.
glands located behind the thyroid gland in the neck. The parathyroid glands secrete a hormone called parathyroid thormone (PTH) that is critical to calcium and phosphorus metabolism.
a disease of the nervous system caused by degeneration of a part of the brain called the basal ganglia, as well as by low production of the neurotransmitter dopamine. Symptoms include muscle rigidity, tremors, and slow voluntary movement.
disease-causing agents, such as viruses or bacteria.
Peptic ulcer disease
a disease characterized by ulcers or breakdown of the inner lining of the stomach or duodenum. Common risk factors for peptic ulcer disease include the use of nonsteroidal anti-inflammatory drugs (NSAIDs) and infection with Helicobacter pylori.
a chain of amino acids. A protein is made up of one or more peptides.
a hormone that is a protein, as opposed to a steroid hormone, which is made from cholesterol. Insulin is an example of a peptide hormone.
through the skin.
Percutaneous transluminal coronary angioplasty (PTCA)
a nonsurgical technique, in which a balloon catheter is inserted into a peripheral artery and passed into an occluded coronary artery, where the balloon is inflated to dilate the artery.
the period of time just before and after birth (varyingly defined as the time period starting between 20 to 28 weeks’ gestation and ending one to four weeks after birth).
Peripheral arterial disease
atherosclerosis of the arteries of the extremities.
a disease or degenerative state affecting the nerves of the extremities (arms and legs). Symptoms may include numbness, pain, and muscle weakness.
Peripheral vascular disease
atherosclerosis of the vessels of the extremities, which may result in insufficient blood flow or pain in the affected limb, particularly during exercise.
a procedure in which a special dialysis solution is introduced through a tube in the peritoneum. The dialysis solution pulls wastes and extra fluid from the body when the dialysis solution is drained through the same tube. The most common form is called continuous ambulatory peritoneal dialysis and can be performed at home without a machine.
a membrane that lines the walls of the abdominal cavity.
the end stage of an autoimmune inflammation of the stomach, resulting in destruction of stomach cells by one’s own antibodies. Progressive destruction of the cells that line the stomach cause decreased secretion of acid and enzymes required to release food bound vitamin B12. Antibodies to intrinsic factor (IF) bind to IF preventing formation of the IF-B12 complex, further inhibiting vitamin B12 absorption.
positron emission tomography scan. A diagnostic imaging technique that uses a sophisticated camera and computer to produce images of how a person’s body is functioning. A PET scan shows the difference between healthy and abnormally functioning tissues.
a measure of acidity or alkalinity.
a specialized cell, such as a macrophage, that engulfs and digests invading microorganisms through the process of phagocytosis.
process by which phagocytes engulf and digest invading microorganisms and foreign particles.
an intracellular vesicle containing the foreign material engulfed by the phagocyte.
the study of the absorption, distribution, metabolism, and elimination of drugs and other compounds.
the dose or intake level of a nutrient many times the level associated with the prevention of deficiency or the maintenance of health. A pharmacologic dose is generally associated with the treatment of a disease state and considered to be a dose at least 10 times greater than that needed to prevent deficiency.
Phase I clinical trial
a clinical trial in a small group of people aimed at determining bioavailability, optimal dose, safety, and early evidence of the efficacy of a new therapy.
Phase II clinical trial
a clinical trial designed to investigate the effectiveness of a new therapy in larger numbers of people and to further evaluate short-term side effects and safety of the new therapy.
Phase III clinical trial
once a drug or treatment has been shown to be efficacious and safe in phase I and II clinical trials, a large, phase III clinical trial must be conducted before the drug or treatment receives formal FDA approval.
a class of chemical compounds consisting of a hydroxyl functional group (-OH) attached to an aromatic hydrocarbon group. An aromatic hydrocarbon has a ring structure like that of benzene. Polyphenolic compounds contain more than one phenolic group.
an inherited disorder resulting in the inability to process the amino acid, phenylananine. If not treated, the disorder may result in mental retardation. Treatment is a diet low in phenylalanine. Newborns are screened for PKU, in order to determine the need for treatment before brain damage occurs.
the removal of blood from a vein. Phlebotomy may be used to obtain blood for diagnostic tests or to treat certain conditions, for example, iron overload in hemochromatosis.
lipid in which phosphoric acid, as well as fatty acids, are attached to a glycerol backbone. Phospholipids are important structural components of cell membranes.
the creation of a phosphate derivative of an organic molecule. This is usually achieved by transferring a phosphate group (-PO4) from ATP to another molecule.
skin damage induced by ultraviolet (UV) light that is absorbed in an uncontrolled manner by molecules in the body. Depending on the dose, UV light can cause cell death and an inflammatory response.
the dose or intake level of a nutrient associated with the prevention of deficiency or the maintenance of health. A physiologic dose of a nutrient is not generally greater than that which could be achieved through a conscientious diet, as opposed to the use of supplements.
biologically active, non-nutrient compound synthesized by plants.
a plant-derived compound with estrogenic activity.
a compound that gives a plant or animal cell color by the selective absorption of different wavelengths of light.
hair follicles in the skin that are associated with a sebaceous gland.
a preliminary study conducted on a small scale in order to prepare for a larger study.
a small oval gland located at the base of the brain that secretes hormones regulating growth and metabolism. The pituitary gland is divided into two separate glands, the anterior and posterior pituitary glands, which each secrete different hormones.
an inert treatment that is given to a control group while the experimental group is given the active treatment. Placebo-controlled studies are conducted to make sure that the results are due to the experimental treatment, rather than another factor associated with participating in the study.
the organ that connects the fetus to the pregnant woman’s uterus, allowing for the exchange of oxygen, carbon dioxide, nutrients, and waste between woman and fetus.
premature separation of the placenta from the wall of the uterus. Abruption is a potentially serious problem both for the woman and fetus.
whole blood without blood cells; that is, red blood cells and white blood cells have been removed. Plasma is separated from blood cells using a centrifuge. Unlike serum, plasma retains clotting factors because it is obtained from blood that is not allowed to clot.
irregularly shaped cell fragments that assist in blood clotting.
a disease of the lungs characterized by inflammation and accumulation of fluid in the lungs. Pneumonia may be caused by infectious agents (e.g., viruses or bacteria) or by inhalation of certain irritants.
a large molecule formed by combining many similar smaller molecules (monomers) in a regular pattern.
a nucleotide difference (variant) in the DNA sequence of a gene. Most polymorphisms are harmless and are part of normal human genetic variation, but some polymorphisms affect the function of the gene product (protein).
a benign (non-cancerous) mass of tissue that forms on the inside of a hollow organ, such as the colon.
a phenolic compound that contains more than one phenolic group.
Polyunsaturated fatty acid
a fatty acid with more than one double bond between carbons.
after eating or after a meal.
a molecule which is an ingredient, reactant, or intermediate in a synthetic pathway for a particular product.
a condition characterized by a sharp rise in blood pressure during the third trimester of pregnancy. High blood pressure may be accompanied by edema (swelling) and proteinuria (protein in the urine). In some cases, untreated preeclampsia can progress to eclampsia, a life-threatening situation for the woman and child.
the proportion of a population with a specific disease or condition at a given point in time.
live cultures of microorganisms that, when administered in sufficient amounts, benefits the overall health of the host.
a carcinogen precursor that must be modified or metabolized to become an active carcinogen.
predicted outcome based on the course of a disease.
the reproduction or multiplication of cells.
DNA sequence to which RNA polymerase binds to initiate transcription.
an atom or molecule that promotes oxidation of another atom or molecule by accepting electrons. Examples of pro-oxidants include free radicals, reactive oxygen species (ROS), and reactive nitrogen species (RNS).
prevention, often refers to a treatment used to prevent a disease.
Prospective cohort study
an observational study in which a group of people—known as a cohort—are interviewed or tested for risk factors (e.g., nutrient intake), and then followed up at subsequent times to determine their status with respect to a disease or health outcome.
cell-signaling molecule that is involved in inflammation. Cyclooxygenases catalyze the formation of prostaglandins from eicosanoids, such as arachidonic acid and eicosapentaenoic acid (EPA).
a gland in men, located at the base of the bladder and surrounds the urethra. The prostate produces fluid that forms part of semen. If the prostate becomes enlarged it may exert pressure on the urethra and cause urinary symptoms. Prostate cancer is one of the most common types of cancer in men.
Prostate-specific antigen (PSA)
a compound normally secreted by the prostate that can be measured in the blood. If prostate cancer is developing, the prostate secretes larger amounts of PSA. Blood tests for PSA are used to screen for prostate cancer and to follow up on prostate cancer treatment.
a complex organic molecule composed of amino acids in a specific order. The order is determined by the sequence of nucleic acids in a gene coding for the protein. Proteins are required for the structure, function, and regulation of the body’s cells, tissues, and organs, and each protein has unique functions.
a large compound comprised of protein and polysaccharide units known as glycosaminoglycans (GAGs). GAGs are polymers of sugars and amino sugars, such as glucosamine or galactosamine. Proteoglycans are integral components of structural tissues like bone and cartilage.
the breakdown of proteins by protease enzymes.
an elementary particle identical to the nucleus of a hydrogen atom, which along with neutrons, is a constituent of all other atomic nuclei. A proton carries a positive charge equal and opposite to that of an electron.
a chronic skin condition often resulting in a red, scaly rash located over the surfaces of the elbows, knees, scalp, and around or in the ears, navel, genitals, or buttocks. Approximately 10-15% of patients with psoriasis develop joint inflammation (psoriatic arthritis). Psoriasis is thought to be an autoimmune condition.
Pyruvate kinase deficiency
a hereditary deficiency of the enzyme pyruvate kinase. Pyruvate kinase deficiency results in hemolytic anemia.
one-fourth of a sample or population.
one-fifth of a sample or population.