the addition of an acetyl group (-COCH3) group to a molecule.
the absence of hydrochloric acid in gastric juice.
having a pH of less than 7.
a condition of the skin characterized by the presence of comedones.
a rare, inherited disorder of impaired zinc absorption.
hyperpigmented patches that occur in sun-exposed skin; also known as liver spots or age spots.
having a short and relatively severe course.
Acute-phase reactant protein
also called acute-phase protein; plasma protein that is synthesized by the liver during acute inflammation. Examples include C-reactive protein (CRP), fibrinogen, serum amyloid A protein, and von Willebrand factor.
the electrochemical signal transmitted in the cell membrane of a neuron or muscle cell. Also called nerve impulse.
specialized connective tissue that functions to store body fat as triglycerides.
a treatment or therapy used in addition to another, not alone.
a pair of small glands, located above the kidneys, consisting of an outer cortex and inner medulla. The adrenal cortex secretes cortisone-related hormones and the adrenal medulla secretes epinephrine (adrenaline) and norepinephrine (noradrenaline).
the nonsugar component of a glycoside. Cleavage of the glycosidic bond of a glycoside results in the formation of a sugar and an aglycone.
adequate intake. Established by the Food and Nutrition Board of the US Institute of Medicine, the AI is a recommended intake value based on observed or experimentally determined estimates of nutrient intake by a group of healthy people that are assumed to be adequate. An AI is established when an RDA cannot be determined.
acquired immune deficiency syndrome. AIDS is caused by the HIV (Human Immunodeficiency Virus) virus, which attacks the immune system, leaving the infected individual vulnerable to opportunistic infections.
basic; having a pH of more than 7.
a plant-derived compound that is biologically active, contains a nitrogen in a heterocyclic ring, is alkaline, has a complex structure, and is of limited distribution in the plant kingdom.
one of a set of alternative forms of a gene. Diploid cells possess two homologous chromosomes (one derived from each parent) and therefore two copies of each gene. In a diploid cell, a gene will have two alleles, each occupying the same position on homologous chromosomes.
loss of hair.
the most common cause of dementia in older adults. Alzheimer’s disease is characterized by the formation of amyloid plaque in the brain and nerve cell degeneration. Symptoms include memory loss and confusion, which worsen over time.
an organic molecule that contains an amino group (-NH2) and a carboxyl group (-COOH); amino acids are as the building blocks of proteins.
a chemical compound having both hydrophilic (water-loving, polar) and lipophilic (fat-loving, nonpolar) properties.
aggregates of a peptide called amyloid-ß, which accumulate and form deposits in the brain in Alzheimer’s disease.
Amyotrophic lateral sclerosis (ALS)
a rapidly progressive and fatal neurological disease caused by degeneration of motor neurons that control voluntary muscle movement. Also known as Lou Gehrig’s disease.
refers to the absence of oxygen or the absence of a need for oxygen.
a chemical compound that is structurally similar to another but differs slightly in composition (e.g., the replacement of one functional group by another).
a rapidly developing and severe systemic allergic reaction. Symptoms may include swelling of the tongue, throat, and trachea, which can result in difficulty breathing, shock and loss of consciousness. If not treated rapidly, anaphylaxis can be fatal.
the condition of having less than the normal number of red blood cells or hemoglobin in the blood, resulting in diminished oxygen transport. Anemia has many cause, including iron, vitamin B12, or folate deficiency; bleeding; abnormal hemoglobin formation (e.g., sickle cell anemia); rupture of red blood cells (hemolytic anemia); and bone marrow diseases.
a birth defect, known as a neural tube defect, resulting from failure of the upper end of the neural tube to close during embryonic development. Anencephaly is a devastating and sometimes fatal birth defect resulting in the absence of most or all of the cerebral hemispheres.
pain generally experienced in the chest, but sometimes radiating to the arms or jaw, due to a lack of oxygen supply to the heart muscle.
the development of new blood vessels.
imaging of the coronary arteries used to identify the location and severity of any obstructions. Coronary angiography typically involves the administration of a contrast medium and imaging of the coronary arteries using an X-ray based technique.
a negatively charged ion.
a substance that counteracts or nullifies the biological effects of another, such as a compound that binds to a receptor but does not elicit a biological response.
a specialized protein produced by white blood cells (lymphocytes) that recognizes and binds to foreign proteins or pathogens in order to neutralize them or mark them for destruction.
a class of compounds that inhibit blood clotting.
a class of medication used to prevent seizures.
a substance that is capable of eliciting an immune response.
a chemical that blocks the effect of histamine in a susceptible tissues. Histamine is released by immune cells during an allergic reaction and also during infection with viruses that cause the common cold. The interaction of histamine with the mucus membranes of the eyes and nose results in “watery eyes” and the “runny nose” often accompanying allergies and colds. Antihistamines can help alleviate such symptoms.
capable of killing or inhibiting the growth of microorganisms, such as bacteria.
any substance that prevents or reduces damage caused by reactive oxygen species (ROS) or reactive nitrogen species (RNS).
a medication or hormone that inhibits bone resorption.
a scoring system used to assess the physical condition of a newborn immediately after birth. Criteria evaluated include respiratory effort, heart rate, skin coloration, muscle tone, and response to stimulation.
gene-directed cell death or programmed cell death that occurs when age, condition, or state of cell health dictates. Cells that die by apoptosis do not usually elicit the inflammatory responses that are associated with necrosis. Cancer cells are resistant to apoptosis.
an abnormal heart rhythm. The heart rhythm may be too fast (tachycardia), too slow (bradycardia) or irregular. Some arrhythmias, such as ventricular fibrillation, may lead to cardiac arrest if not treated promptly.
a lack of oxygen or excess carbon dioxide in the body that causes unconsciousness.
a chronic inflammatory disease of the airways, characterized by recurrent episodes of reversible airflow obstruction.
a lack of coordination or unsteadiness usually related to a disturbance in the cerebellum, a part of the brain that regulates coordination and equilibrium.
capable of producing atherosclerosis.
an inflammatory disease resulting in the accumulation of cholesterol-laden plaque in artery walls. Rupture of atherosclerotic plaque results in clot formation, which may result in myocardial infarction or ischemic stroke.
adenosine triphosphate. An important compound for the storage of energy in cells, as well as the synthesis of nucleic acids.
(singular: atrium) two upper chambers of the heart that receive blood from the veins and contract to force that blood into the ventricles.
a cardiac arrhythmia, characterized by rapid, uncoordinated beating of the atria, which results in ineffective atrial contractions. Atrial fibrillation is known as a supraventricular arrhythmia because it originates above the ventricles.
a chronic inflammation of the lining of the stomach, which ultimately results in the loss of glands in the stomach (atrophy) and decreased stomach acid production.
a decrease in size or wasting away of a body part or tissue.
a reduction in number.
a condition in which the body’s immune system reacts against its own tissues.
the phosphorylation by a protein of one or more of its own amino acid residues. Autophosphorylation does not necessarily occur on the same polypeptide chain as the catalytic site. In a dimer, one subunit may phosphorylate the other.
refers to a trait or gene that is not located on the X or Y chromosome (not sex-linked).
long extension of a neuron that transmits nerve impulses away from the cell body toward other neurons or muscle cells.
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single-celled organisms that can exist independently, symbiotically (in cooperation with another organism) or parasitically (dependent upon another organism, sometimes to the detriment of the other organism). Examples of bacteria include acidophilus (found in yogurt); streptococcus the cause of strep throat; and E. coli (a normal intestinal bacteria, as well as a disease-causing agent).
a nutritional balance study involves the measurement of the intake of a specific nutrient as well as the elimination of that nutrient in urine, feces, sweat, etc. If intake is greater than loss of a particular nutrient the individual is said to be in “positive balance.” If intake is less than loss, an individual is said to be in “negative balance” for the nutrient of interest.
Benign prostatic hyperplasia
the term used to describe a noncancerous enlargement of the prostate.
any systematic error in an epidemiological study that results in an incorrect estimate of the association between an exposure and disease risk.
a yellow, green fluid made in the liver and stored in the gallbladder. Bile may then pass through the common bile duct into the small intestine where some of its components aid in the digestion of fat.
components of bile, which are formed by the metabolism of cholesterol, and aid in the digestion of fats.
the fraction of an administered compound that reaches the systemic circulation and is transported to site of action (target tissue).
a physical, functional, or biochemical indicator of a physiological or disease process.
Biotransformation enzymes (phase I and phase II)
enzymes involved in the metabolism and elimination of a variety of exogenous (drugs, toxins and carcinogens) and endogenous compounds (steroid hormones). In general, phase I biotransformation enzymes, including those of the cytochrome P450 family, catalyze reactions that increase the reactivity of fat-soluble compounds and prepare them for reactions catalyzed by phase II biotransformation enzymes. Reactions catalyzed by phase II enzymes generally increase water solubility and promote the elimination of these compounds.
a mood disorder previously called “manic-depressive illness.” Bipolar disorder is characterized by severe alterations in mood. During “manic” episodes, a person may experience extreme elevation in energy level and mood (euphoria) or extreme agitation and irritability. Episodes of depressed mood are also common in bipolar disorder.
Body mass index (BMI)
body weight in kilograms divided by height in meters squared. In adults, BMI is a measure of body fat: underweight, <18.5; normal weight, 18.5-24.9; overweight, 25-29.9; obese, =30. Calculate your BMI.
Bone mineral density (BMD)
the amount of mineral in a given area of bone. BMD is positively associated with bone strength and resistance to fracture, and measurements of BMD are used to diagnose osteoporosis.
the continuous turnover process of bone that includes bone resorption and bone formation. An imbalance in the regulation of the two contrasting events of bone remodeling (bone resorption and bone formation) increases the fragility of bone and may lead to osteoporosis.
long-standing inflammation of the airways, characterized by excess production of sputum, leading to a chronic cough and obstruction of air flow. Cigarette smoking is the most common cause of chronic bronchitis.
a chemical used to maintain the pH of a system by absorbing hydrogen ions (which would make it more acidic) or absorbing hydroxyl ions (which would make it more alkaline).