- Email: [email protected]
Glossary (of Terms and Definitions)
Glossary (of Terms and Definitions) ABCC8 gene The gene that encodes ATP-binding cassette transporter subfamily C member 8; this gene provides instructions for making the sulfonylurea receptor 1 (SUR1) protein. Acanthosis nigricans A skin pigmentation disorder involving dark patches of skin, with a thick yet soft texture, in various areas of the body; it may be a sign of prediabetes. Acetoacetate A salt or ion of acetoacetic acid; a ketone body formed in ketogenesis; its presence is increased in diabetic ketoacidosis. Acinar cells Secreting cells lining an acinus, which is any of the smallest lobules of a compound gland, especially the pancreatic cells that provide pancreatic enzymes. Acromegaly Excessive enlargement of the limbs due to thickening of bones and soft tissues, caused by hypersecretion of growth hormone, usually from a tumor of the pituitary gland. Adenylate cyclase An enzyme that catalyzes the conversion of ATP to cyclic adenosine monophosphate (cAMP) and inorganic pyrophosphate (PPi); activated by attachment of a hormone or neurotransmitter to a specific membrane-bound receptor. Adipocytes Fat cells; connective tissue cells distended with one or more fat globules. Adipokines Cytokines produced by adipose tissue, acting locally in an autocrine-paracrine fashion as systemically as hormones. Adiponectin A protein hormone produced and secreted by adipocytes into the systemic circulation; it causes sensitivity of peripheral tissues to insulin. Adrenocorticotropic hormone Also called corticotropin, or abbreviated as ACTH; it is secreted by the anterior lobe of the pituitary gland, stimulating the cortex of the adrenal gland to secrete its hormones, including corticosterone Alleles Two or more genes that control the same characteristic. Alpha (α) cells Endocrine cells in the pancreatic islets that make up to 20% of the islet cells synthesizing and secreting glucagon, which elevates glucose levels in the blood. Alpha-glucosidase inhibitors Orally administered agents used to treat type 2 diabetes; examples include acarbose, which slows digestion and absorption of glucose into the bloodstream. Alpha ketoglutarate Abbreviated as AKG; it is the anion of alpha-ketoglutaric acid, and an important biological compound; it is the keto acid produced by deamination of glutamate, and is an intermediate in the Krebs cycle. Amino acids The molecular building blocks of proteins; organic compounds that form the ingredients of proteins. Ampulla of Vater Also called the hepatopancreatic ampulla or the hepatopancreatic duct; it is formed by the union of the pancreatic duct and the common bile duct, and specifically located at the major duodenal papilla. Amputation To surgically remove a body part, often due to a disease such as diabetes mellitus. Amylin A peptide hormone secreted with insulin by the pancreatic beta-cells; it helps regulate blood glucose levels by inhibiting glucagon secretion, and by slowing the rate at which food leaves the stomach. Amylopectin A highly branched polysaccharide of high molecule weight; one of the two main components, along with amylose, of starches. Amylose A linear, unbranched polysaccharides; one of the two main components, along with amylopectin, of starches. Android The type of fat distribution mainly around the trunk and upper body, in areas such as the abdomen, chest, shoulder, and nape of the neck; it is commonly linked to diabetes mellitus. Anion gap A value calculated from results of multiple medical lab tests; the difference in measured cations and measured anions in serum, plasma, or urine; it may help identify the cause of metabolic acidosis. Anti-insulin Anti-islet cell antibodies present in the blood as part of type 1 diabetes. Apgar scores Numerical assessments that measure the health of newborns, immediately after birth; based on appearance, pulse, grimace, activity, and respiration. Apoptosis A process of programmed cell death, following biochemical events leading to morphology of cells, including blebbing (cell blistering), cell shrinkage, nuclear fragmentation, chromatin condensation, chromosomal DNA fragmentation, and global mRNA decay. Apoproteins Conjugated proteins from which the prosthetic group has been removed, such as apohemoglobin. Atherogenesis Formation of atheromatous deposits, especially on the innermost layer of arterial walls.
175
176
Glossary (of Terms and Definitions)
Atherosclerosis A form of arteriosclerosis, characterized by the presence of plaques on the innermost layer of the walls of large and medium-sized arteries; it may lead to heart attack, stroke, and other cardiovascular problems. Autoantibodies Antibodies that react with cells, tissues, or native proteins of the individual in which they are produced. Autoantigens Endogenous antigens that stimulate autoantibody production, as in autoimmune reactions. Basal Related to the base of something; of primary importance; basic; fundamental; essential. Beckwith-Wiedemann syndrome An autosomal dominant syndrome involving enlargement of the tongue and visceral organs, gigantism, umbilical hernia, and often, neonatal hypoglycemia. Bed cradle A frame placed over the body of a patient in bed for application of heat or cold, or for protecting injured parts from coming into contact with bed clothes. Beta (β) cells The insulin-producing cells of the pancreatic islets of Langerhans. Beta-hydroxybutyrate A ketone body or salt of 3-hydroxybutyric acid, involved in fatty acid metabolism, which is increased in diabetic ketoacidosis. Biallelic Of, relating to, or affecting both alleles of a gene. Biguanides Oral antihyperglycemic agents that work by limiting glucose production and absorption, and by increasing the body’s sensitivity to insulin; glucophage is an example. Bile salts Sodium salts of bile acids occurring in bile; or commercial preparations used as hepatic stimulants or laxatives. Binge drinking Consumption of a large number of alcoholic beverages within a short period of time. Blood brain barrier The barrier separating the blood from the brain parenchyma everywhere except in the hypothalamus; it is permeable to water, oxygen, carbon dioxide, and nonionic solutes such as glucose, alcohol, and general anesthetics. Bolus A concentrated mass of pharmaceutical preparation, given intravenously or swallowed. Brown adipose tissue A thermogenic type of adipose tissue containing a dark pigment, arising during embryonic life in certain specific areas such as the neck, chest, abdomen, and back. C-peptide The 30 amino acids chain connecting the A and B chains of insulin in proinsulin; removed in the conversion of proinsulin to insulin. Calpain-10 gene A susceptibility gene for type 2 diabetes mellitus. Carbohydrate exchange system Also called carbohydrate counting; a meal-planning method that involves keeping total carbohydrate intake consistent from day to day; it is used to improve overall blood glucose control. Cardiac autonomic neuropathy (CAN) A serious medical condition that often creates instability in heart rate control, as well as complications with central and peripheral vascular dynamics; it has been linked to greater risk of death due to autonomic performance of the heart. Carotid angioplasty and stenting Procedures that open closed arteries to restore blood flow to the brain; often performed to treat or prevent stroke. Carotid endarterectomy Surgical removal of atherosclerotic plaques in an extracranial carotid artery, usually the common carotid, to prevent stroke in patients with 70% of greater carotid stenosis. Casual blood glucose test Also called the random plasma glucose test; it does not require the patient to fast, and is usually performed when a physician does not want to wait for a fasting blood sugar test, or in an emergency situation. Cataracts Opacities of the lenses of the eyes, or their capsules; most cataracts a part of the normal aging process. Catecholamines Sympathomimetic amines, including dopamine, epinephrine, and norepinephrine that play an important role in the body’s physiological response to stress; they elevated blood glucose levels by hepatic and skeletal muscle glycogenolysis. Celiac disease A disease of the digestive system that damages the small intestine and interferes with absorption of nutrients from food; it occurs when the body reacts abnormally to gluten, a protein in wheat, rye, barley, and possibly oats. Celiac trunk The arterial trunk arising from the abdominal aorta, giving origin to the left gastric, common hepatic, and splenic arteries. Cellulose A carbohydrate forming the skeleton of most plant structures and plant cells; the most abundant polysaccharide in nature and the source of dietary fiber. Ceramide The basic unit of the sphingolipids, consisting of sphingosine or a related base, attached via its amino group to a longchain fatty acid anion. Charcot’s foot A deformity of the foot associated with neuropathies; the nerves are damaged due to loss of blood flow and the bones are also weakened; without treatment, continued walking changes the shape of the foot and the joints are seriously damaged; also called neurogenic arthropathy. Cholecystokinin A polypeptide hormone secreted in the small intestine; it stimulates gallbladder contraction and secretion of pancreatic enzymes. Cholesterol A steroid alcohol in animal fats and oils, bile, blood, brain tissue, milk, egg yolk, and the myelin sheaths of nerve fibers, liver, kidneys, and adrenal glands; high levels of total serum cholesterol are linked to increased risk for coronary artery disease and myocardial infarction. Chromosome 8 One of the 23 pairs of human chromosomes; it is involved in brain development and function, and cancer. Chronic obstructive pulmonary disease (COPD) A progressive lung disease in which there is poor airflow in the lungs, characterized by wheezing, shortness of breath with difficulty exhaling, and coughing.
Glossary (of Terms and Definitions)
177
Chylomicronemia The presence of chylomicrons, especially increased numbers in the circulating blood, as in type I familial hyperlipoproteinemia. Common hepatic artery The visceral branch of the celiac trunk of the abdominal aorta, passing posterior to the pylorus and dividing into the gastroduodenal, right gastric, right hepatic, left hepatic, and middle hepatic branches. Continuous glucose monitoring A system that provides continuous insight into glucose levels through the day and night, using a device that provides information every 5 minutes. Corticotropin-releasing hormone A neuropeptide secreted by the median eminence of the hypothalamus; it binds to specific receptors on the corticotroph cells of the anterior pituitary, stimulating secretion of corticotropin. Cushing syndrome A disorder resulting from increased adrenocortical secretion of cortisol, due to ACTH-dependent adrenocortical hyperplasia or tumor, ectopic ACTH-secreting tumor, or excessive administration of steroids; it involves decreased carbohydrate tolerance. Cystic fibrosis An inherited disease that affects the lungs, digestive system, sweat glands, and male fertility; the most common complication of cystic fibrosis is secondary diabetes, especially in patients under 10 years of age. Cytokines Nonantibody proteins released by one cell population on contact with a specific antigen, which act as intercellular mediators, such as in the generation of the immune response. Dawn phenomenon Abrupt increases in fasting levels of plasma glucose concentrations between 5:00 and 9:00 a.m., without antecedent hypoglycemia; it occurs in diabetic patients receiving insulin therapy. Delta (δ) cells The pancreatic islet of Langerhans cells that secrete somatostatin. Dephosphorylation The process of removing a phosphate group from a compound, usually hydrolytically and by enzyme action. Diabetic ketoacidosis A dangerous complication of diabetes mellitus, in which the chemical balance of the body becomes dangerously acidic. Dipeptidyl peptidase-4 inhibitors Oral hypoglycemics that block dipeptidyl peptidase-4, in the treatment of type 2 diabetes mellitus. Disability adjusted life years Abbreviated as DALYs, a measure of the burden disease upon a population, based on adjustment of life expectancy allowing for long-term disability as estimated from official national statistics. Disaccharides Sugars with molecules that each yield two molecules of monosaccharide upon hydrolysis. Disomy The state of an individual or cell having two members of a pair of homologous chromosomes; it is the normal state in humans, in comparison to monosomy and trisomy. Double diabetes Hybrid diabetes, also called type-3 diabetes or type 1 and a half diabetes; it combines features of type 1 and type 2 diabetes. Dysgeusia Distortion in the perception of a certain taste, such as an unpleasant perception of a normally pleasant taste, or a perception of taste when no stimuli present. Dyslipidemia Abnormality in, or abnormal amounts of lipids and lipoproteins in the blood. Eicosanoids Substances derived from arachidonic acid, including leukotrienes, prostaglandins, and thromboxanes. Emphysematous Related to, or affected with emphysema. Essential An amino acid that must be directly obtained from food; these include valine, leucine, isoleucine, phenylalanine, tryptophan, threonine, lysine, arginine, methionine, and histidine. Esthesiometer A tactometer; an instrument for measuring tactile sensibility. Euglycemia A normal level of glucose in the blood. Excipients Mostly inert substances added as diluents or vehicles to give form or consistency to a medication; examples include syrups, gums, powders, and elixirs. Exogenous Developed or originating outside an organism. Facilitated diffusion The protein-mediated transport of a compound across a biomembrane that is not ion-drive; a saturable transport system. Fasting plasma glucose test A test that measures blood glucose after fasting for at least 8 hours. Fatty acids Monoprotic acids, such as found in animal and vegetable fats and oils, made up of saturated or unsaturated compounds having an even number of carbon atoms; examples include palmitic, stearic, and oleic acids. Fibrinogen A protein in blood plasma that is essential for blood coagulation; it is converted to fibrin by the action of thrombin, in the presence of ionized calcium. Fournier’s gangrene An acute gangrenous infection of the scrotum, penis, or perineum after local trauma, operations, underlying urinary tract disease, or a distant acute inflammatory process. Free fatty acid flux An excessive flow of free fatty acids, used to predict the development of insulin resistance. Free fatty acids Nonesterified fatty acids released by hydrolysis of triglycerides in adipose tissue; they can be used as immediate energy sources by many organs, and can be converted by the liver into ketone bodies. Fructosamine A glycosylated protein measured to monitor control of diabetes mellitus over a period of several weeks. Fructose A monosaccharide in honey and many sweet fruits; used in solution as a fluid and nutrient replenisher; also called levulose or fruit sugar. Galactose A monosaccharide sugar of the aldose group, derived from lactose.
178
Glossary (of Terms and Definitions)
Gangrene The decay or death of an organ or tissue caused by lack of blood supply; resulting from changes associated with diseases such as diabetes mellitus. Gastrin A polypeptide hormone secreted by certain cells of the pyloric glands; it strongly stimulates secretion of gastric acid and pepsin; it also weakly stimulates secretion of pancreatic enzymes and gallbladder contraction. Gastroparesis Paralysis of the stomach; also called gastroparalysis and gastroplegia. Genotypes An individual’s entire genetic makeup. Gestational diabetes mellitus A condition during pregnancy, involves a defect in how the body processes and uses glucose in the diet; the pancreas is not involved while the placenta is implicated. Ghrelin A hormone secreted by the stomach cells that promotes hunger, decreases after eating, and promotes secretion of growth hormone. Glaucoma An ocular disease of many forms, with the primary characteristic being an unstable or sustained increase in intraocular pressure that causes structural and functional impairments, leading to blindness. Glucagon A 29-amino acid pancreatic peptide secreted by the pancreatic alpha cells that plays an important role in regulation of blood glucose concentration, ketone metabolism, and many biochemical and physiological processes. Glucagon-like peptide-1 agonists Also called GLP-1 receptor agonists or incretin mimetics, these are agonists of the GLP-1 receptor used for the treatment of type 2 diabetes. Glucocorticoids A class of corticosteroids that bind to the glucocorticoid receptor; they aid in regulation of glucose metabolism, its synthesis in the adrenal cortex, and the steroidal structure of glucose; also called glucocorticosteroids. Glucokinase An enzyme, which in the presence of ATP, catalyzes glucose to glucose-6-phosphate. Gluconeogenesis The metabolic pathway resulting in generation of glucose from noncarbohydrate carbon substrates; it aids in maintaining blood glucose levels. Glucose Also called dextrose, a simple sugar that is the most abundant monosaccharide; it is the most important source of energy. Glucose-6-phosphatase An enzyme that hydrolyzes glucose-6-phosphate, resulting in creation of a phosphate group and free glucose. Glucose tolerance tests Medical tests in which glucose is given and blood samples are taken to determine how quickly it is cleared from the blood; usually used to test for diabetes, insulin resistance, impaired beta cell function; also to test for reactive hypoglycemia, acromegaly, or rare carbohydrate metabolism disorders. Glucose transporter 4 Abbreviated as GLUT4, it is a protein encoded by the SLC2A4 gene that is regulated by insulin, and found mostly in skeletal and cardiac muscle. Glycated Also called glycosylated, describing a glycoside (especially a glycoprotein) that has the sugar entity intact. Glyceraldehyde A monosaccharide that is the simplest of all common aldoses; an intermediate compound in carbohydrate metabolism, from combining glycerol with one hydroxymethyl group oxidized to an aldehyde. Glycemia The presence or level of glucose in the blood. Glycemic index A number associated with carbohydrates in a food source indicating their effect on the blood glucose level; a value of 100 represents the standard, an equivalent amount of pure glucose. Glycemic load A number estimating how much a food source will raise the blood glucose level after it is eaten; one unit of glycemic load approximates the effect of consuming one gram of glucose. Glycerol Also called glycerin; a simple polyol compound that is the “backbone” of all triglycerides; it is widely used as a food sweetener. Glycogen A polysaccharide of glucose that serves as a form of energy storage; the main storage form of glucose in the body. Glycogenesis The process of glycogen synthesis, which glucose molecules are added to chains of glycogen for storage. Glycogenolysis The breakdown of glycogen to glucose-1-phospahte and glycogen. Glycolipids Lipids with a carbohydrate attached by a covalent bond; they maintain stability of cell membranes and facilitate cellular recognition. Glycoproteins Proteins that contain oligosaccharide chains called glycans that are covalently attached to amino acid side-chains; they are often important integral membrane proteins. Glycosphingolipid A glycolipid subtype, containing the amino alcohol sphingosine; it is part of the cell membrane. Glycosylated hemoglobin Also called hemoglobin A1c, AbA1c, A1C, or Hb1c; a form of hemoglobin mostly measured to identify the 3-month average plasma glucose concentration. Glycosylation The reaction in which a carbohydrate is attached to a hydroxyl or other functional group of another molecule; it mainly refers to the enzymatic process that attaches glycans to proteins or other organic molecules. Gynecoid Also called gynoid; body fat that forms around the hips, breasts, and thighs; it is less dangerous than android fat distribution. Hemoglobin A1c Glycosylated hemoglobin; it is measured to identify the 3-month average plasma glucose concentration. High fructose corn syrup A sweetener made from corn starch, processed by glucose isomerase, converting some of its glucose into fructose. Hippocampus The part of the brain’s limbic system that plays important roles in memory; located under the cerebral cortex; its neurons are vulnerable to severe hypoglycemia or hyperglycemia.
Glossary (of Terms and Definitions)
179
Human leukocyte antigen Abbreviated as HLA, it is a gene complex that encodes the major histocompatibility complex (MHC) proteins responsible for regulation of the immune system. HYMAI gene The hydatidiform mole associated and imprinted long noncoding form of RNA; it is an imprinted gene that is paternally expressed; its overexpression, along with that of the PLAG1 gene, causes transient neonatal type 1 diabetes mellitus. Hyperandrogenism Excessive levels of androgens in the female body; it is linked with polycystic ovary syndrome and certain cancers. Hyperglycemia High blood glucose, usually considered to be more than 11.1 mmol/L, or 200 mg/dL. Hyperinsulinism Higher than normal levels of insulin in the blood; associated with reduced insulin sensitivity, hyperglycemia, excessive insulin secretion, and hypoglycemia. Hyperketonemia An excessive amount of ketones in the blood; ketosis is a metabolic state that occurs when the body is metabolizing fat at a high rate, and converting fatty acids into ketones. Hyperosmolar Pertaining to hyperosmolality, which is an increase in the osmolality of body fluids; related conditions are known as hyperosmolar nonketotic coma and hyperosmolar nonketotic diabetes. Hyperosmolar hyperglycemic nonketotic syndrome Abbreviated as HHNKS or HHNS, it is a complication of diabetes in which high blood glucose results in high osmolarity without significant ketoacidosis; usually caused by type 2 diabetes mellitus, but sometimes by type 1 diabetes, or in patients with no diabetes history. Hyperviscosity Increased blood viscosity, which means “thickness.” Hypoalbuminemia A medical sign in which albumin levels in the blood are abnormally low; it is a type of hypoproteinemia. Hypoglycemia Low blood sugar; it occurs when blood glucose concentration falls below the level necessary to support the body’s need for energy and stability throughout its cells. Hypophyseotropic Also spelled “hypophysiotropic”; acting upon the pituitary gland (hypophysis); usually referring to the effects of a hormone. Hypothyroidism Underactive thyroid; it develops when the thyroid gland fails to produce or secret as much thyroxine (T4) as the body needs. In utero Inside the uterus. Incretin One of a group of gastrointestinal hormones that stimulate secretion of insulin by the pancreas. Indole A crystalline, alkaloid compound that is a decomposition product of proteins containing tryptophan; it can also be manufactured synthetically. Inositol triphosphate Also called triphosphoinositol; along with diacylglycerol, it is a secondary messenger molecule used in signal transduction and lipid signaling in biological cells. INS gene The gene that encodes preproinsulin, a precursor of insulin. Insidious onset Development of a disease that occurs quickly, or follows symptoms that are vague and do not point to any specific disease or condition; diabetes mellitus may develop in this manner. Insulin A peptide hormone produced by the pancreatic islet beta-cells; the main anabolic hormone of the body; it regulates metabolism of carbohydrates, fats, and proteins. Insulin autoimmune syndrome A rare condition that causes hypoglycemia; it occurs suddenly, as antibodies are produced that attack the body’s own insulin. Insulin resistance A pathological condition in which the cells fail to normally respond to insulin; it is linked to poor diet. Interleukin 6 (IL-6) A pro-inflammatory cytokine as well as an anti-inflammatory myokine; it is encoded by the IL-6 gene. Internal limitation The functional limiting of the endocrine system; as a result of this process, diabetes is considered an “invisible disability.” Islet amyloid polypeptide Also called amylin; it is co-secreted with insulin from the pancreatic beta-cells, with insulin being 100 times the amount of amylin; it plays a role in glycemic regulation by slowing gastric emptying and promoting fullness, preventing postprandial blood glucose level spikes. Islets of Langerhans Also called the pancreatic islets; regions of the pancreas that contain its endocrine cells; the islets make up 1% 2% of the pancreas volume, and receive 10% 15% of its blood flow; they are important in the metabolism of glucose. Isodisomy A trait caused by both copies of a chromosomal set being inherited from the biological mother or the father; it may result in the expression of recessive traits in the offspring. Isoenergetic Having the same or constant energy. Kallikreinogen A plasma protein that is the precursor of kallikrein, which is an enzyme that helps produce bradykinin and activates coagulation factors; plasma deficient in pre-kallikrein is abnormal in thromboplastin formation, kinin generation, evolution of a permeability globulin, and plasmin formation. KCNJ11 gene The gene that provides instructions for making subunits of the ATP-sensitive potassium channel; potassium-ATP channels are found in beta-cells of the pancreas. Ketoacids Organic compounds containing a carboxylic acid group and a ketone group; alpha-ketoacids are important for the Krebs cycle and in glycolysis. Ketone bodies Water-soluble molecules (acetoacetate, beta-hydroxybutyrate, and their breakdown product, acetone) that contain the ketone group produced by the liver from fatty acids during fasting, starvation, carbohydrate restrictive diets, prolong intense exercise, alcoholism, or in poorly treated type 2 diabetes mellitus.
180
Glossary (of Terms and Definitions)
Ketosis-prone diabetes Abbreviated as KPD, it is an intermediate form of diabetes with characteristics of both type 1 and type 2 diabetes; its single characteristic is ketoacidosis. Killer T lymphocytes Also known as cytotoxic T cells; white blood cells that kill cancer cells, infected cells—especially with viruses, or cells damaged in other ways. Kussmaul respirations Deep, labored breathing patterns often associated with severe metabolic acidosis—especially diabetic ketoacidosis, but also with kidney failure; the respirations are described as “gasping for air.” Labile Constantly changing, or likely to being changing. Lancet A pricking needle used to obtain drops of blood for testing. Leptin A hormone mostly made by adipose cells; it helps regulate energy balance by inhibiting hunger; it is opposed by the hormone ghrelin; in obesity, a decreased sensitivity to leptin occurs. Linoleic acid A polyunsaturated omega-6 fatty acid that usually occurs as a triglyceride ester; it cannot be synthesized from food sources, and is abundant in many nuts, fatty seeds, and oils such as safflower, sunflower, corn, and soybean. Lipases Enzymes that catalyze the hydrolysis of lipids; human pancreatic lipase is the main enzyme that breaks down dietary fats and converts triglyceride substrates into monoglycerides and two fatty acids. Lipemia retinalis A white appearance of the retina that can occur from lipid deposition in lipoprotein lipase deficiency. Lipids Fats; biomolecules that are soluble in nonpolar solvents (usually, hydrocarbons); lipids are used for storing energy, signaling, and acting as structural components of cell membranes. Lipolysis The breakdown of lipids, which involves hydrolysis of triglycerides into glycerol and free fatty acids; it is directly induced in adipocytes by glucagon, epinephrine, norepinephrine, growth hormone, atrial natriuretic peptide, brain natriuretic peptide, and cortisol. Lipoproteins Molecules made of proteins and fat; they carry cholesterol and similar substances through the blood; a high level of lipoprotein-A is considered a risk factor for heart disease. Macromolecules A very large molecule, such as protein, usually created by polymerization of smaller monomers; the most common macromolecules are nucleic acids, proteins, carbohydrates, lipids, and macrocycles. Macrosomia “Long body”; when an infant’s body is longer than normal while the weight may be varied; sometimes confused with “large for gestational age,” which describes infant birth weight greater than the 97th percentile of most infants. Major histocompatibility complex Abbreviated as MHC, a set of cell surface proteins essential for the acquired immune system to recognize foreign molecules; this determines histocompatibility. Mesangial cell(s) A specialized cell, or cells, in the kidney making up the mesangium of the glomerulus; they help form the vascular pole of the renal corpuscle, and account for 30% 40% of the total cells of the glomerulus. Metabolic programming An adaptive process that occurs in response to a nutritional stimulus or insult during a vulnerable period of susceptibility, early in life. Microalbumin A term referring to very small levels of albumin in the urine; a urine microalbumin test is used to detect early signs of kidney damage in people at risk of developing kidney disease. Microangiopathic Related to disease of the small blood vessels in the body; it is opposite to the term microangiopathic, which describes disease of the large blood vessels. Monosaccharides Simple sugars that cannot be further hydrolyzed to simpler chemical compounds; examples include glucose, fructose, and galactose. Multimer Similar to an oligomer in relation to proteins; an oligomer is a molecular complex of chemicals that consists of a few monomer units, in contrast to a polymer, where the number of monomers may be extremely large. N-acetyl-galactosamine An amino sugar derivative of galactose, which is the terminal carbohydrate forming the antigen of blood group A; it is necessary for intercellular communication and is concentrated in sensory nerve structures. N-acetyl-neuraminic acid The predominant sialic acid, found in complex glycans on mucins and glycoproteins of the cell membrane; it is involved in preventing infections, and can also be used as a nutrient. Necrotizing fasciitis Also called “flesh-eating disease,” an infection that results in death of the body’s soft tissue; it is sudden, severe, and spreads rapidly; risk factors include poor immune function, such as from diabetes. Neonatal diabetes A disease that affects infants and their ability to produce or use insulin; it is a monogenic form that occurs in the first 6 months of life, and only occurs rarely; its two forms are permanent and transient. Nesidioblastosis A term that describes hyperinsulinemic hypoglycemic attributed to excessive pancreatic beta-cell function, with an abnormal microscopic appearance; it also describes a form of acquired hyperinsulism with beta-cell hyperplasia in adults, especially after gastrointestinal surgery. Neuroglycopenia Glycopenia in the brain, usually due to hypoglycemia; it affects the function of neurons, and alters brain function and behavior; if prolonged or recurrent, it can cause loss of consciousness, brain damage, and death. Nodular glomerulosclerosis Hardening of the glomeruli in the kidney, with the presence of nodules, a condition related to diabetes; chronic loss of kidney function occurs, as well as nephrotic syndrome and end-stage kidney disease. Nonessential An amino acid that can be produced by the body; these include: glycine, alanine, serine, asparagine, glutamine, tyrosine, aspartic acid, glutamic acid, proline, and cysteine.
Glossary (of Terms and Definitions)
181
Nonketotic hyperosmolar syndrome (NKHS) A condition that usually affects adults, often as the initial manifestation of type 1 diabetes mellitus, or because of gastroenteritis; diabetic hyperosmolar syndrome is a medical emergency caused by a very high blood glucose level. Oligosaccharides Saccharide polymers containing 3 10 monosaccharides; they have many functions including cell recognition and cell binding. Omental Referring to an omentum, which is a layer of peritoneum that surrounds abdominal organs. Oral glucose tolerance test A medical test in which glucose is ingested by mouth and blood levels are checked 2 hours later; there are many variations of this test for various purposes. Orthostatic hypotension Also called postural hypotension; it occurs when blood pressure falls from suddenly standing up after lying down or sitting; a reduction in systolic blood pressure (at least 20 mmHg), or of the diastolic blood pressure (at least 10 mmHg); it is often related to autonomic neuropathy. Osmotic diuresis The removal of water from the body because of a high concentration of osmotically active substances in the renal tubules, such as urea or sodium sulfate, which limit reabsorption of water. Osteocalcin Also called bone gamma-carboxyglutamic acid-containing protein; a noncollagenous protein hormone in bone and dentin; it requires vitamin K for synthesis and plays roles in metabolic regulation, bone mineralization, calcium ion homeostasis, and insulin release from the pancreatic beta cells. Osteomyelitis A bone infection that is linked to diabetes, intravenous drug use, splenectomy, and trauma to the area of infection. Oxidated A state in which oxidation has occurred; a loss of electrons, or an increase in the oxidation state by a molecule, atom, or ion. Pancreas A glandular organ that is part of the endocrine and digestive systems; it produces insulin, glucagon, somatostatin, and pancreatic polypeptide; it also secretes pancreatic juice and digestive enzymes that help break down carbohydrates, proteins, and lipids. Pancreatic islets Also called the islets of Langerhans; areas of the pancreas that contain its endocrine cells. Paracrine Relating to a type of hormone function in which its effects are restricted to the local environment; also, the secretion of a hormone by an organ other than an endocrine gland. Paresthesias Abnormal dermal sensations with no apparent physical causes; they are most common in the extremities, and often related to metabolic disorders such as diabetes mellitus. Pentose phosphate pathway Also called the phosphogluconate pathway, it is a metabolic pathway parallel to glycolysis; it involves an oxidative phase and the nonoxidative synthesis of 5-carbon sugars. Peptide bond An amide-type of covalent chemical bond linking two alpha-amino acids from carbon number one of one alpha-amino acid and nitrogen number two of another, along a peptide or protein chain; also known as an eupeptide bond; it is a type of condensation reaction. Peripheral insulin resistance Insulin levels in the blood are high, while there is no hypoglycemia; it may be caused by variances in insulin receptors that regulate the effects of insulin. Pheochromocytoma A tumor of the chromaffin cells, most often found in the middle of the adrenal gland. Phospholipids A class of lipids that are a major component of all cell membranes; they form lipid bilayers and usually consist of two hydrophobic fatty acid tails and a hydrophilic head consisting of a phosphate group; the first identified phospholipid was lecithin, in the egg yolk of chickens. Phosphorylates Adding a phosphate group to an organic molecule; causing or going through phosphorylation; or introducing a trivalent group into an organic compound. Photocoagulation The precursor technique to “laser coagulation”; it utilized light coagulation, meaning a beam of light, to treat retinal detachment. Podiatrist A medical professional who studies and treats the feet, ankles, and lower extremities. Polycystic ovary disease A condition in which a female has little or no menstruation, is infertile, has excessive body hair, and is obese; the ovaries may contain several cysts. Polymorphisms Alterations of either chromosomes, genes, genetic branches, lipids, electrical waves, forms within a population, or DNA sequences. Polysaccharides Carbohydrate molecules composed of long chains of monosaccharides bound by glycosidic links; in hydrolysis, they release monosaccharides or oligosaccharides; storage polysaccharides include starch and glycogen; structural polysaccharides include cellulose and chitin. Polyunsaturated fatty acids Forms of carboxylic acids with hydrocarbon chains that possess two or more carbon carbon double bounds; they can be found in nuts, seeds, fish, seed oils, and oysters; they are considered beneficial to health. Postabsorptive stage Also called the postabsorptive state; a metabolic period that occurs when the stomach and intestines are empty; energy needs are fulfilled from energy previously stored in the body. Postprandial After eating a meal. Pramlintide An injectable amylin analog drug for both type 1 and type 2 diabetes. Preeclampsia A disorder of pregnancy characterized by high blood pressure, and often, a significant amount of protein in the urine; it begins after 20 weeks of pregnancy and influences the risk of poor outcomes for both mother and baby; risk factors include obesity, prior hypertension, older age, and diabetes mellitus.
182
Glossary (of Terms and Definitions)
Prevalence In epidemiology, the proportion of a particular population found to be affected by a medical condition; usually expressed as a fraction, percentage, or as the number of cases per 10,000 or 100,000 people. Proinsulin The prohormone precursor to insulin made in the pancreatic beta-cells, and encoded by the INS gene. Pyelonephritis Inflammation of the kidney, usually due to a bacterial infection; risk factors include sexual intercourse, prior urinary tract infections, diabetes, structural problems of the urinary tract, and use of spermicides. Resistin Also called adipose tissue-specific secretory factor (ASDF); a cysteine-rich adipose-derived peptide hormone encoded by the RETN gene that is believed to be involved in obesity and type 2 diabetes mellitus. Retinopathy Any damage to the retina of the eyes, which may cause vision impairment; it often refers to retinal vascular disease, or damage caused by abnormal blood flow; there are proliferative and nonproliferative types, and retinopathy is often related to diabetes or hypertension. Retroperitoneal Located behind a peritoneum of the body; organs are retroperitoneal if they have peritoneum on their anterior side only. Rhabdomyolysis A condition in which damaged skeletal muscle breaks down rapidly; it may damage the kidneys and lead to kidney failure. Ribose A pentose monosaccharide (simple sugar) with derivatives, such as ATP and NADH, that play central roles in metabolism. Saturated fatty acids Forms of carboxylic acids that contain no double bonds between the carbon atoms, being saturated with hydrogen; they cannot be broken down in the body, so they collect and are stored; examples include lauric, myristic, palmitic, and stearic acids; sources include dairy products, fatty meats, and oils. Schwann cells The principal glia of the peripheral nervous system (PNS), supporting neurons; they include satellite cells, olfactory ensheathing cells, enteric glia, glia at sensory nerve endings; they may be myelinating or nonmyelinating. Secretagogues Substances that cause other substances to be secreted; examples include gastrin, histamine, acetylcholine, sulfonylureas, and angiotensin II. Secretin A peptide hormone that regulates water homeostasis in the body, and affects the duodenum by regulating secretions in the stomach, pancreas, and liver; it is encoded by the SCT gene, and also stimulates bile production, emulsifying dietary fats so that pancreatic lipase can act upon them. Serotonergic Pertaining to or affecting serotonin, a neurotransmitter; examples of serotonergic agents include serotonin receptor agonists and antagonists, reuptake inhibitors, and releasing agents. Sialic acid A generic term for the nitrogen or oxygen substituted derivatives of neuraminic acid, a monosaccharide with a ninecarbon backbone; also, another name for N-acetyl-neuraminic acid. Soluble fiber The type of fiber that dissolves in water and is easily fermented in the colon into gases and short-chain fatty acids; it delays gastric emptying, resulting in an extended feeling of fullness. Somatostatin Also called growth hormone-inhibiting hormone (GHIH), a peptide hormone with endocrine effects on neurotransmission and cell proliferation via interaction with G protein-coupled somatostatin receptors, and inhibition of the release of many secondary hormones; it inhibits insulin and glucagon secretion. Soto syndrome Also called Sotos syndrome, cerebral gigantism, or Sotos-Dodge syndrome; a rare genetic disorder characterized by excessive growth in the first few years of life; there may also be autism, intellectual disability, delayed development, hypotonia, and speech impairments. Sphingolipid A type of lipid with a backbone of sphingoid bases; a set of aliphatic amino alcohol including sphingosine; they are important in signal transmission and cell recognition. Sphingomyelin A type of sphingolipid in animal cell membranes, especially in the myelin sheath surrounding some nerve cell axons; it participates in many signaling pathways. Sphingosine An 18-carbon amino alcohol with an unsaturated hydrocarbon chain that forms a main part of sphingolipids. Spirometry The most common pulmonary function test, which measures lung function—especially the volume and flow of air that can be inhaled and exhaled. Splenic artery The blood vessel that supplies oxygenated blood to the spleen, branching from the celiac artery; it follows a course superior to the pancreas. Splenic vein The blood vessel that drains blood from the spleen, stomach fundus, and part of the pancreas. Starch Also called amylum; a polymeric carbohydrate consisting of many glucose units joined by glycosidic bonds; the most common carbohydrate in human diets; found in large amounts in potatoes, wheat, corn, rice, and cassava. Steroids Biologically active organic compounds that are important components of cell membranes, and act as signaling molecules; examples of steroids include the sterols, which include cholesterol, estradiol, testosterone, and dexamethasone. Sulfonylureas Organic compounds used in the management of type 2 diabetes that act by increasing insulin release form the pancreatic beta-cells; examples include tolbutamide, glyburide, glipizide, and glimepiride. Superior mesenteric artery The blood vessel arising from the anterior surface of the abdominal aorta, just inferior to the origin of the celiac trunk; it supplies the intestine from the lower duodenum through two-thirds of the transverse colon, as well as the pancreas. Susceptibility genes Alterations of genes that increase an individual’s predisposition, or susceptibility, to a certain disease or disorder.
Glossary (of Terms and Definitions)
183
Synaptic clefts Small spaces adjacent to neurons, into which neurotransmitter molecules are released from synaptic vesicles. Thermogenesis The process of heat production in the body. Thiazolidinediones Also called glitazones; heterocyclic compounds used in the treatment of type 2 diabetes; they activate peroxisome proliferator-activated receptors. Thrifty gene hypothesis Also called Gianfranco’s hypothesis; an explanation of why certain modern populations are prone to type 2 diabetes mellitus; it has been expanded to include obesity, and is based on genes that can cause fat to deposit when there is plenty of food, to account for later periods of food shortage. Trans fatty acids Also called trans fat or unsaturated fatty acids; they are linked to increased risk of coronary artery disease. Transaminated The use of a chemical reaction to transfer an amino acid group to a ketoacid group, forming new amino acids; it utilizes enzymes called transaminases or aminotransferases. Transmucosal The absorption of a substance through the mucous membranes; examples include membranes of the nose, tongue and mouth, vagina, etc. Triacylglycerol Also known as triglyceride or triacylglycerides; an ester derived from glycerol and three fatty acids; the main constituents of body fat; divided primarily into saturated and unsaturated types. Triglycerides Also called triacylglycerols or triacylglycerides. Trisaccharides Oligosaccharides with three monosaccharides and two connecting glycosidic bonds; examples include maltotriose, melezitose, and raffinose. Tumor necrosis factor-alpha (TNFα) Also called cachexin or cachectin; a cytokine involved in systemic inflammation, involved in the acute phase reaction; mostly produced by activated macrophages; it regulates immune cells. Type 1 diabetes mellitus A form of diabetes in which very little or no insulin is produced by the pancreas; this results in high glucose levels in the body, classic symptoms of frequent urination, increased thirst, increased hunger, and weight loss; it is caused by genetic and environmental factors and involves autoimmune destruction of the insulin-producing beta-cells of the pancreas. Type 2 diabetes mellitus A form of diabetes characterized by high blood glucose insulin resistance, and a relative lack of insulin; it primarily occurs because of obesity and lack of exercise; long-term complications include heart disease, stroke, diabetic retinopathy, kidney failure, and poor blood flow to the limbs. Uncoupling protein (UCP-1) Also called thermogenin; it is found in the mitochondria of brown adipose tissue and used to generate heat by nonshivering thermogenesis; it is very important to prevent heat loss in neonates. Unsaturated fatty acids Those in which there is at least one double bond within the fatty acid chain; they may be monounsaturated or polyunsaturated fatty acids, which can replace saturated fat in the diet; this helps reduce levels of total cholesterol and LDL cholesterol in the blood. Vascular dementia Also called multi-infarct dementia or vascular cognitive impairment; it is caused by alterations in the brain’s blood supply, usually from a series of minor strokes; this leads to worsening cognitive decline over time. Vasoactive intestinal peptide (VIP) Also called vasoactive intestinal polypeptide, it is vasoactive in the intestines; it stimulates heart contractility, causes vasodilation, increases glycogenolysis, lowers arterial blood pressure, and relaxes muscles; this peptide is encoded by the VIP gene. Vitiligo A condition in which a loss of melanocytes results in smooth, white patches in the midst of normally pigmented skin. White adipose tissue Also called white fat; in healthy people, it is composed of 20% of male body weight and 25% of female body weight; it is used as a storage form of energy; upon insulin release from the pancreas, this type of fat’s insulin receptors causes a dephosphorylation cascaded, inactivating lipase. Xanthomas Deposits of yellowish cholesterol-rich material anywhere on the body, due to various diseases; they may be related to hyperlipidemia, chronic biliary tract obstruction, and primary biliary cirrhosis. ZAC gene The zinc-activated ion channel gene, also called the ZACN gene; zinc-activated ion channel mRNA is expressed in the prostate, thyroid, trachea, lung, brain, spinal cord, skeletal muscle, heart, placenta, pancreas, liver, kidney, and stomach. Zedoary seed A herb that was used by the Persian physician Avicenna, along with the flowing plant called lupine and the herb trigonella (fenugreek) to produce a significant reduction in excretion of sugar for diabetic patients. ZFP57 gene The gene that encodes the zinc finger protein 57 homolog or ZFP57; this protein is believed to function as a transcriptional repressor; mutations of the ZFP57 gene may be linked to transient neonatal diabetes mellitus. Zinc transporter 8 autoantibody The antibody to the insulin secretory granule zinc transporter (ZnT8), which is a producer of the SLC30A8 gene; many people with type 1 diabetes have this antibody, while those with type 2 or gestational diabetes do not; the first such antibody is now being used to diagnose type 1 diabetes. Zymogens Also called proenzymes; they are inactive precursors of enzymes that require biochemical changes in order to act.
175
176
Glossary (of Terms and Definitions)
Atherosclerosis A form of arteriosclerosis, characterized by the presence of plaques on the innermost layer of the walls of large and medium-sized arteries; it may lead to heart attack, stroke, and other cardiovascular problems. Autoantibodies Antibodies that react with cells, tissues, or native proteins of the individual in which they are produced. Autoantigens Endogenous antigens that stimulate autoantibody production, as in autoimmune reactions. Basal Related to the base of something; of primary importance; basic; fundamental; essential. Beckwith-Wiedemann syndrome An autosomal dominant syndrome involving enlargement of the tongue and visceral organs, gigantism, umbilical hernia, and often, neonatal hypoglycemia. Bed cradle A frame placed over the body of a patient in bed for application of heat or cold, or for protecting injured parts from coming into contact with bed clothes. Beta (β) cells The insulin-producing cells of the pancreatic islets of Langerhans. Beta-hydroxybutyrate A ketone body or salt of 3-hydroxybutyric acid, involved in fatty acid metabolism, which is increased in diabetic ketoacidosis. Biallelic Of, relating to, or affecting both alleles of a gene. Biguanides Oral antihyperglycemic agents that work by limiting glucose production and absorption, and by increasing the body’s sensitivity to insulin; glucophage is an example. Bile salts Sodium salts of bile acids occurring in bile; or commercial preparations used as hepatic stimulants or laxatives. Binge drinking Consumption of a large number of alcoholic beverages within a short period of time. Blood brain barrier The barrier separating the blood from the brain parenchyma everywhere except in the hypothalamus; it is permeable to water, oxygen, carbon dioxide, and nonionic solutes such as glucose, alcohol, and general anesthetics. Bolus A concentrated mass of pharmaceutical preparation, given intravenously or swallowed. Brown adipose tissue A thermogenic type of adipose tissue containing a dark pigment, arising during embryonic life in certain specific areas such as the neck, chest, abdomen, and back. C-peptide The 30 amino acids chain connecting the A and B chains of insulin in proinsulin; removed in the conversion of proinsulin to insulin. Calpain-10 gene A susceptibility gene for type 2 diabetes mellitus. Carbohydrate exchange system Also called carbohydrate counting; a meal-planning method that involves keeping total carbohydrate intake consistent from day to day; it is used to improve overall blood glucose control. Cardiac autonomic neuropathy (CAN) A serious medical condition that often creates instability in heart rate control, as well as complications with central and peripheral vascular dynamics; it has been linked to greater risk of death due to autonomic performance of the heart. Carotid angioplasty and stenting Procedures that open closed arteries to restore blood flow to the brain; often performed to treat or prevent stroke. Carotid endarterectomy Surgical removal of atherosclerotic plaques in an extracranial carotid artery, usually the common carotid, to prevent stroke in patients with 70% of greater carotid stenosis. Casual blood glucose test Also called the random plasma glucose test; it does not require the patient to fast, and is usually performed when a physician does not want to wait for a fasting blood sugar test, or in an emergency situation. Cataracts Opacities of the lenses of the eyes, or their capsules; most cataracts a part of the normal aging process. Catecholamines Sympathomimetic amines, including dopamine, epinephrine, and norepinephrine that play an important role in the body’s physiological response to stress; they elevated blood glucose levels by hepatic and skeletal muscle glycogenolysis. Celiac disease A disease of the digestive system that damages the small intestine and interferes with absorption of nutrients from food; it occurs when the body reacts abnormally to gluten, a protein in wheat, rye, barley, and possibly oats. Celiac trunk The arterial trunk arising from the abdominal aorta, giving origin to the left gastric, common hepatic, and splenic arteries. Cellulose A carbohydrate forming the skeleton of most plant structures and plant cells; the most abundant polysaccharide in nature and the source of dietary fiber. Ceramide The basic unit of the sphingolipids, consisting of sphingosine or a related base, attached via its amino group to a longchain fatty acid anion. Charcot’s foot A deformity of the foot associated with neuropathies; the nerves are damaged due to loss of blood flow and the bones are also weakened; without treatment, continued walking changes the shape of the foot and the joints are seriously damaged; also called neurogenic arthropathy. Cholecystokinin A polypeptide hormone secreted in the small intestine; it stimulates gallbladder contraction and secretion of pancreatic enzymes. Cholesterol A steroid alcohol in animal fats and oils, bile, blood, brain tissue, milk, egg yolk, and the myelin sheaths of nerve fibers, liver, kidneys, and adrenal glands; high levels of total serum cholesterol are linked to increased risk for coronary artery disease and myocardial infarction. Chromosome 8 One of the 23 pairs of human chromosomes; it is involved in brain development and function, and cancer. Chronic obstructive pulmonary disease (COPD) A progressive lung disease in which there is poor airflow in the lungs, characterized by wheezing, shortness of breath with difficulty exhaling, and coughing.
Glossary (of Terms and Definitions)
177
Chylomicronemia The presence of chylomicrons, especially increased numbers in the circulating blood, as in type I familial hyperlipoproteinemia. Common hepatic artery The visceral branch of the celiac trunk of the abdominal aorta, passing posterior to the pylorus and dividing into the gastroduodenal, right gastric, right hepatic, left hepatic, and middle hepatic branches. Continuous glucose monitoring A system that provides continuous insight into glucose levels through the day and night, using a device that provides information every 5 minutes. Corticotropin-releasing hormone A neuropeptide secreted by the median eminence of the hypothalamus; it binds to specific receptors on the corticotroph cells of the anterior pituitary, stimulating secretion of corticotropin. Cushing syndrome A disorder resulting from increased adrenocortical secretion of cortisol, due to ACTH-dependent adrenocortical hyperplasia or tumor, ectopic ACTH-secreting tumor, or excessive administration of steroids; it involves decreased carbohydrate tolerance. Cystic fibrosis An inherited disease that affects the lungs, digestive system, sweat glands, and male fertility; the most common complication of cystic fibrosis is secondary diabetes, especially in patients under 10 years of age. Cytokines Nonantibody proteins released by one cell population on contact with a specific antigen, which act as intercellular mediators, such as in the generation of the immune response. Dawn phenomenon Abrupt increases in fasting levels of plasma glucose concentrations between 5:00 and 9:00 a.m., without antecedent hypoglycemia; it occurs in diabetic patients receiving insulin therapy. Delta (δ) cells The pancreatic islet of Langerhans cells that secrete somatostatin. Dephosphorylation The process of removing a phosphate group from a compound, usually hydrolytically and by enzyme action. Diabetic ketoacidosis A dangerous complication of diabetes mellitus, in which the chemical balance of the body becomes dangerously acidic. Dipeptidyl peptidase-4 inhibitors Oral hypoglycemics that block dipeptidyl peptidase-4, in the treatment of type 2 diabetes mellitus. Disability adjusted life years Abbreviated as DALYs, a measure of the burden disease upon a population, based on adjustment of life expectancy allowing for long-term disability as estimated from official national statistics. Disaccharides Sugars with molecules that each yield two molecules of monosaccharide upon hydrolysis. Disomy The state of an individual or cell having two members of a pair of homologous chromosomes; it is the normal state in humans, in comparison to monosomy and trisomy. Double diabetes Hybrid diabetes, also called type-3 diabetes or type 1 and a half diabetes; it combines features of type 1 and type 2 diabetes. Dysgeusia Distortion in the perception of a certain taste, such as an unpleasant perception of a normally pleasant taste, or a perception of taste when no stimuli present. Dyslipidemia Abnormality in, or abnormal amounts of lipids and lipoproteins in the blood. Eicosanoids Substances derived from arachidonic acid, including leukotrienes, prostaglandins, and thromboxanes. Emphysematous Related to, or affected with emphysema. Essential An amino acid that must be directly obtained from food; these include valine, leucine, isoleucine, phenylalanine, tryptophan, threonine, lysine, arginine, methionine, and histidine. Esthesiometer A tactometer; an instrument for measuring tactile sensibility. Euglycemia A normal level of glucose in the blood. Excipients Mostly inert substances added as diluents or vehicles to give form or consistency to a medication; examples include syrups, gums, powders, and elixirs. Exogenous Developed or originating outside an organism. Facilitated diffusion The protein-mediated transport of a compound across a biomembrane that is not ion-drive; a saturable transport system. Fasting plasma glucose test A test that measures blood glucose after fasting for at least 8 hours. Fatty acids Monoprotic acids, such as found in animal and vegetable fats and oils, made up of saturated or unsaturated compounds having an even number of carbon atoms; examples include palmitic, stearic, and oleic acids. Fibrinogen A protein in blood plasma that is essential for blood coagulation; it is converted to fibrin by the action of thrombin, in the presence of ionized calcium. Fournier’s gangrene An acute gangrenous infection of the scrotum, penis, or perineum after local trauma, operations, underlying urinary tract disease, or a distant acute inflammatory process. Free fatty acid flux An excessive flow of free fatty acids, used to predict the development of insulin resistance. Free fatty acids Nonesterified fatty acids released by hydrolysis of triglycerides in adipose tissue; they can be used as immediate energy sources by many organs, and can be converted by the liver into ketone bodies. Fructosamine A glycosylated protein measured to monitor control of diabetes mellitus over a period of several weeks. Fructose A monosaccharide in honey and many sweet fruits; used in solution as a fluid and nutrient replenisher; also called levulose or fruit sugar. Galactose A monosaccharide sugar of the aldose group, derived from lactose.
178
Glossary (of Terms and Definitions)
Gangrene The decay or death of an organ or tissue caused by lack of blood supply; resulting from changes associated with diseases such as diabetes mellitus. Gastrin A polypeptide hormone secreted by certain cells of the pyloric glands; it strongly stimulates secretion of gastric acid and pepsin; it also weakly stimulates secretion of pancreatic enzymes and gallbladder contraction. Gastroparesis Paralysis of the stomach; also called gastroparalysis and gastroplegia. Genotypes An individual’s entire genetic makeup. Gestational diabetes mellitus A condition during pregnancy, involves a defect in how the body processes and uses glucose in the diet; the pancreas is not involved while the placenta is implicated. Ghrelin A hormone secreted by the stomach cells that promotes hunger, decreases after eating, and promotes secretion of growth hormone. Glaucoma An ocular disease of many forms, with the primary characteristic being an unstable or sustained increase in intraocular pressure that causes structural and functional impairments, leading to blindness. Glucagon A 29-amino acid pancreatic peptide secreted by the pancreatic alpha cells that plays an important role in regulation of blood glucose concentration, ketone metabolism, and many biochemical and physiological processes. Glucagon-like peptide-1 agonists Also called GLP-1 receptor agonists or incretin mimetics, these are agonists of the GLP-1 receptor used for the treatment of type 2 diabetes. Glucocorticoids A class of corticosteroids that bind to the glucocorticoid receptor; they aid in regulation of glucose metabolism, its synthesis in the adrenal cortex, and the steroidal structure of glucose; also called glucocorticosteroids. Glucokinase An enzyme, which in the presence of ATP, catalyzes glucose to glucose-6-phosphate. Gluconeogenesis The metabolic pathway resulting in generation of glucose from noncarbohydrate carbon substrates; it aids in maintaining blood glucose levels. Glucose Also called dextrose, a simple sugar that is the most abundant monosaccharide; it is the most important source of energy. Glucose-6-phosphatase An enzyme that hydrolyzes glucose-6-phosphate, resulting in creation of a phosphate group and free glucose. Glucose tolerance tests Medical tests in which glucose is given and blood samples are taken to determine how quickly it is cleared from the blood; usually used to test for diabetes, insulin resistance, impaired beta cell function; also to test for reactive hypoglycemia, acromegaly, or rare carbohydrate metabolism disorders. Glucose transporter 4 Abbreviated as GLUT4, it is a protein encoded by the SLC2A4 gene that is regulated by insulin, and found mostly in skeletal and cardiac muscle. Glycated Also called glycosylated, describing a glycoside (especially a glycoprotein) that has the sugar entity intact. Glyceraldehyde A monosaccharide that is the simplest of all common aldoses; an intermediate compound in carbohydrate metabolism, from combining glycerol with one hydroxymethyl group oxidized to an aldehyde. Glycemia The presence or level of glucose in the blood. Glycemic index A number associated with carbohydrates in a food source indicating their effect on the blood glucose level; a value of 100 represents the standard, an equivalent amount of pure glucose. Glycemic load A number estimating how much a food source will raise the blood glucose level after it is eaten; one unit of glycemic load approximates the effect of consuming one gram of glucose. Glycerol Also called glycerin; a simple polyol compound that is the “backbone” of all triglycerides; it is widely used as a food sweetener. Glycogen A polysaccharide of glucose that serves as a form of energy storage; the main storage form of glucose in the body. Glycogenesis The process of glycogen synthesis, which glucose molecules are added to chains of glycogen for storage. Glycogenolysis The breakdown of glycogen to glucose-1-phospahte and glycogen. Glycolipids Lipids with a carbohydrate attached by a covalent bond; they maintain stability of cell membranes and facilitate cellular recognition. Glycoproteins Proteins that contain oligosaccharide chains called glycans that are covalently attached to amino acid side-chains; they are often important integral membrane proteins. Glycosphingolipid A glycolipid subtype, containing the amino alcohol sphingosine; it is part of the cell membrane. Glycosylated hemoglobin Also called hemoglobin A1c, AbA1c, A1C, or Hb1c; a form of hemoglobin mostly measured to identify the 3-month average plasma glucose concentration. Glycosylation The reaction in which a carbohydrate is attached to a hydroxyl or other functional group of another molecule; it mainly refers to the enzymatic process that attaches glycans to proteins or other organic molecules. Gynecoid Also called gynoid; body fat that forms around the hips, breasts, and thighs; it is less dangerous than android fat distribution. Hemoglobin A1c Glycosylated hemoglobin; it is measured to identify the 3-month average plasma glucose concentration. High fructose corn syrup A sweetener made from corn starch, processed by glucose isomerase, converting some of its glucose into fructose. Hippocampus The part of the brain’s limbic system that plays important roles in memory; located under the cerebral cortex; its neurons are vulnerable to severe hypoglycemia or hyperglycemia.
Glossary (of Terms and Definitions)
179
Human leukocyte antigen Abbreviated as HLA, it is a gene complex that encodes the major histocompatibility complex (MHC) proteins responsible for regulation of the immune system. HYMAI gene The hydatidiform mole associated and imprinted long noncoding form of RNA; it is an imprinted gene that is paternally expressed; its overexpression, along with that of the PLAG1 gene, causes transient neonatal type 1 diabetes mellitus. Hyperandrogenism Excessive levels of androgens in the female body; it is linked with polycystic ovary syndrome and certain cancers. Hyperglycemia High blood glucose, usually considered to be more than 11.1 mmol/L, or 200 mg/dL. Hyperinsulinism Higher than normal levels of insulin in the blood; associated with reduced insulin sensitivity, hyperglycemia, excessive insulin secretion, and hypoglycemia. Hyperketonemia An excessive amount of ketones in the blood; ketosis is a metabolic state that occurs when the body is metabolizing fat at a high rate, and converting fatty acids into ketones. Hyperosmolar Pertaining to hyperosmolality, which is an increase in the osmolality of body fluids; related conditions are known as hyperosmolar nonketotic coma and hyperosmolar nonketotic diabetes. Hyperosmolar hyperglycemic nonketotic syndrome Abbreviated as HHNKS or HHNS, it is a complication of diabetes in which high blood glucose results in high osmolarity without significant ketoacidosis; usually caused by type 2 diabetes mellitus, but sometimes by type 1 diabetes, or in patients with no diabetes history. Hyperviscosity Increased blood viscosity, which means “thickness.” Hypoalbuminemia A medical sign in which albumin levels in the blood are abnormally low; it is a type of hypoproteinemia. Hypoglycemia Low blood sugar; it occurs when blood glucose concentration falls below the level necessary to support the body’s need for energy and stability throughout its cells. Hypophyseotropic Also spelled “hypophysiotropic”; acting upon the pituitary gland (hypophysis); usually referring to the effects of a hormone. Hypothyroidism Underactive thyroid; it develops when the thyroid gland fails to produce or secret as much thyroxine (T4) as the body needs. In utero Inside the uterus. Incretin One of a group of gastrointestinal hormones that stimulate secretion of insulin by the pancreas. Indole A crystalline, alkaloid compound that is a decomposition product of proteins containing tryptophan; it can also be manufactured synthetically. Inositol triphosphate Also called triphosphoinositol; along with diacylglycerol, it is a secondary messenger molecule used in signal transduction and lipid signaling in biological cells. INS gene The gene that encodes preproinsulin, a precursor of insulin. Insidious onset Development of a disease that occurs quickly, or follows symptoms that are vague and do not point to any specific disease or condition; diabetes mellitus may develop in this manner. Insulin A peptide hormone produced by the pancreatic islet beta-cells; the main anabolic hormone of the body; it regulates metabolism of carbohydrates, fats, and proteins. Insulin autoimmune syndrome A rare condition that causes hypoglycemia; it occurs suddenly, as antibodies are produced that attack the body’s own insulin. Insulin resistance A pathological condition in which the cells fail to normally respond to insulin; it is linked to poor diet. Interleukin 6 (IL-6) A pro-inflammatory cytokine as well as an anti-inflammatory myokine; it is encoded by the IL-6 gene. Internal limitation The functional limiting of the endocrine system; as a result of this process, diabetes is considered an “invisible disability.” Islet amyloid polypeptide Also called amylin; it is co-secreted with insulin from the pancreatic beta-cells, with insulin being 100 times the amount of amylin; it plays a role in glycemic regulation by slowing gastric emptying and promoting fullness, preventing postprandial blood glucose level spikes. Islets of Langerhans Also called the pancreatic islets; regions of the pancreas that contain its endocrine cells; the islets make up 1% 2% of the pancreas volume, and receive 10% 15% of its blood flow; they are important in the metabolism of glucose. Isodisomy A trait caused by both copies of a chromosomal set being inherited from the biological mother or the father; it may result in the expression of recessive traits in the offspring. Isoenergetic Having the same or constant energy. Kallikreinogen A plasma protein that is the precursor of kallikrein, which is an enzyme that helps produce bradykinin and activates coagulation factors; plasma deficient in pre-kallikrein is abnormal in thromboplastin formation, kinin generation, evolution of a permeability globulin, and plasmin formation. KCNJ11 gene The gene that provides instructions for making subunits of the ATP-sensitive potassium channel; potassium-ATP channels are found in beta-cells of the pancreas. Ketoacids Organic compounds containing a carboxylic acid group and a ketone group; alpha-ketoacids are important for the Krebs cycle and in glycolysis. Ketone bodies Water-soluble molecules (acetoacetate, beta-hydroxybutyrate, and their breakdown product, acetone) that contain the ketone group produced by the liver from fatty acids during fasting, starvation, carbohydrate restrictive diets, prolong intense exercise, alcoholism, or in poorly treated type 2 diabetes mellitus.
180
Glossary (of Terms and Definitions)
Ketosis-prone diabetes Abbreviated as KPD, it is an intermediate form of diabetes with characteristics of both type 1 and type 2 diabetes; its single characteristic is ketoacidosis. Killer T lymphocytes Also known as cytotoxic T cells; white blood cells that kill cancer cells, infected cells—especially with viruses, or cells damaged in other ways. Kussmaul respirations Deep, labored breathing patterns often associated with severe metabolic acidosis—especially diabetic ketoacidosis, but also with kidney failure; the respirations are described as “gasping for air.” Labile Constantly changing, or likely to being changing. Lancet A pricking needle used to obtain drops of blood for testing. Leptin A hormone mostly made by adipose cells; it helps regulate energy balance by inhibiting hunger; it is opposed by the hormone ghrelin; in obesity, a decreased sensitivity to leptin occurs. Linoleic acid A polyunsaturated omega-6 fatty acid that usually occurs as a triglyceride ester; it cannot be synthesized from food sources, and is abundant in many nuts, fatty seeds, and oils such as safflower, sunflower, corn, and soybean. Lipases Enzymes that catalyze the hydrolysis of lipids; human pancreatic lipase is the main enzyme that breaks down dietary fats and converts triglyceride substrates into monoglycerides and two fatty acids. Lipemia retinalis A white appearance of the retina that can occur from lipid deposition in lipoprotein lipase deficiency. Lipids Fats; biomolecules that are soluble in nonpolar solvents (usually, hydrocarbons); lipids are used for storing energy, signaling, and acting as structural components of cell membranes. Lipolysis The breakdown of lipids, which involves hydrolysis of triglycerides into glycerol and free fatty acids; it is directly induced in adipocytes by glucagon, epinephrine, norepinephrine, growth hormone, atrial natriuretic peptide, brain natriuretic peptide, and cortisol. Lipoproteins Molecules made of proteins and fat; they carry cholesterol and similar substances through the blood; a high level of lipoprotein-A is considered a risk factor for heart disease. Macromolecules A very large molecule, such as protein, usually created by polymerization of smaller monomers; the most common macromolecules are nucleic acids, proteins, carbohydrates, lipids, and macrocycles. Macrosomia “Long body”; when an infant’s body is longer than normal while the weight may be varied; sometimes confused with “large for gestational age,” which describes infant birth weight greater than the 97th percentile of most infants. Major histocompatibility complex Abbreviated as MHC, a set of cell surface proteins essential for the acquired immune system to recognize foreign molecules; this determines histocompatibility. Mesangial cell(s) A specialized cell, or cells, in the kidney making up the mesangium of the glomerulus; they help form the vascular pole of the renal corpuscle, and account for 30% 40% of the total cells of the glomerulus. Metabolic programming An adaptive process that occurs in response to a nutritional stimulus or insult during a vulnerable period of susceptibility, early in life. Microalbumin A term referring to very small levels of albumin in the urine; a urine microalbumin test is used to detect early signs of kidney damage in people at risk of developing kidney disease. Microangiopathic Related to disease of the small blood vessels in the body; it is opposite to the term microangiopathic, which describes disease of the large blood vessels. Monosaccharides Simple sugars that cannot be further hydrolyzed to simpler chemical compounds; examples include glucose, fructose, and galactose. Multimer Similar to an oligomer in relation to proteins; an oligomer is a molecular complex of chemicals that consists of a few monomer units, in contrast to a polymer, where the number of monomers may be extremely large. N-acetyl-galactosamine An amino sugar derivative of galactose, which is the terminal carbohydrate forming the antigen of blood group A; it is necessary for intercellular communication and is concentrated in sensory nerve structures. N-acetyl-neuraminic acid The predominant sialic acid, found in complex glycans on mucins and glycoproteins of the cell membrane; it is involved in preventing infections, and can also be used as a nutrient. Necrotizing fasciitis Also called “flesh-eating disease,” an infection that results in death of the body’s soft tissue; it is sudden, severe, and spreads rapidly; risk factors include poor immune function, such as from diabetes. Neonatal diabetes A disease that affects infants and their ability to produce or use insulin; it is a monogenic form that occurs in the first 6 months of life, and only occurs rarely; its two forms are permanent and transient. Nesidioblastosis A term that describes hyperinsulinemic hypoglycemic attributed to excessive pancreatic beta-cell function, with an abnormal microscopic appearance; it also describes a form of acquired hyperinsulism with beta-cell hyperplasia in adults, especially after gastrointestinal surgery. Neuroglycopenia Glycopenia in the brain, usually due to hypoglycemia; it affects the function of neurons, and alters brain function and behavior; if prolonged or recurrent, it can cause loss of consciousness, brain damage, and death. Nodular glomerulosclerosis Hardening of the glomeruli in the kidney, with the presence of nodules, a condition related to diabetes; chronic loss of kidney function occurs, as well as nephrotic syndrome and end-stage kidney disease. Nonessential An amino acid that can be produced by the body; these include: glycine, alanine, serine, asparagine, glutamine, tyrosine, aspartic acid, glutamic acid, proline, and cysteine.
Glossary (of Terms and Definitions)
181
Nonketotic hyperosmolar syndrome (NKHS) A condition that usually affects adults, often as the initial manifestation of type 1 diabetes mellitus, or because of gastroenteritis; diabetic hyperosmolar syndrome is a medical emergency caused by a very high blood glucose level. Oligosaccharides Saccharide polymers containing 3 10 monosaccharides; they have many functions including cell recognition and cell binding. Omental Referring to an omentum, which is a layer of peritoneum that surrounds abdominal organs. Oral glucose tolerance test A medical test in which glucose is ingested by mouth and blood levels are checked 2 hours later; there are many variations of this test for various purposes. Orthostatic hypotension Also called postural hypotension; it occurs when blood pressure falls from suddenly standing up after lying down or sitting; a reduction in systolic blood pressure (at least 20 mmHg), or of the diastolic blood pressure (at least 10 mmHg); it is often related to autonomic neuropathy. Osmotic diuresis The removal of water from the body because of a high concentration of osmotically active substances in the renal tubules, such as urea or sodium sulfate, which limit reabsorption of water. Osteocalcin Also called bone gamma-carboxyglutamic acid-containing protein; a noncollagenous protein hormone in bone and dentin; it requires vitamin K for synthesis and plays roles in metabolic regulation, bone mineralization, calcium ion homeostasis, and insulin release from the pancreatic beta cells. Osteomyelitis A bone infection that is linked to diabetes, intravenous drug use, splenectomy, and trauma to the area of infection. Oxidated A state in which oxidation has occurred; a loss of electrons, or an increase in the oxidation state by a molecule, atom, or ion. Pancreas A glandular organ that is part of the endocrine and digestive systems; it produces insulin, glucagon, somatostatin, and pancreatic polypeptide; it also secretes pancreatic juice and digestive enzymes that help break down carbohydrates, proteins, and lipids. Pancreatic islets Also called the islets of Langerhans; areas of the pancreas that contain its endocrine cells. Paracrine Relating to a type of hormone function in which its effects are restricted to the local environment; also, the secretion of a hormone by an organ other than an endocrine gland. Paresthesias Abnormal dermal sensations with no apparent physical causes; they are most common in the extremities, and often related to metabolic disorders such as diabetes mellitus. Pentose phosphate pathway Also called the phosphogluconate pathway, it is a metabolic pathway parallel to glycolysis; it involves an oxidative phase and the nonoxidative synthesis of 5-carbon sugars. Peptide bond An amide-type of covalent chemical bond linking two alpha-amino acids from carbon number one of one alpha-amino acid and nitrogen number two of another, along a peptide or protein chain; also known as an eupeptide bond; it is a type of condensation reaction. Peripheral insulin resistance Insulin levels in the blood are high, while there is no hypoglycemia; it may be caused by variances in insulin receptors that regulate the effects of insulin. Pheochromocytoma A tumor of the chromaffin cells, most often found in the middle of the adrenal gland. Phospholipids A class of lipids that are a major component of all cell membranes; they form lipid bilayers and usually consist of two hydrophobic fatty acid tails and a hydrophilic head consisting of a phosphate group; the first identified phospholipid was lecithin, in the egg yolk of chickens. Phosphorylates Adding a phosphate group to an organic molecule; causing or going through phosphorylation; or introducing a trivalent group into an organic compound. Photocoagulation The precursor technique to “laser coagulation”; it utilized light coagulation, meaning a beam of light, to treat retinal detachment. Podiatrist A medical professional who studies and treats the feet, ankles, and lower extremities. Polycystic ovary disease A condition in which a female has little or no menstruation, is infertile, has excessive body hair, and is obese; the ovaries may contain several cysts. Polymorphisms Alterations of either chromosomes, genes, genetic branches, lipids, electrical waves, forms within a population, or DNA sequences. Polysaccharides Carbohydrate molecules composed of long chains of monosaccharides bound by glycosidic links; in hydrolysis, they release monosaccharides or oligosaccharides; storage polysaccharides include starch and glycogen; structural polysaccharides include cellulose and chitin. Polyunsaturated fatty acids Forms of carboxylic acids with hydrocarbon chains that possess two or more carbon carbon double bounds; they can be found in nuts, seeds, fish, seed oils, and oysters; they are considered beneficial to health. Postabsorptive stage Also called the postabsorptive state; a metabolic period that occurs when the stomach and intestines are empty; energy needs are fulfilled from energy previously stored in the body. Postprandial After eating a meal. Pramlintide An injectable amylin analog drug for both type 1 and type 2 diabetes. Preeclampsia A disorder of pregnancy characterized by high blood pressure, and often, a significant amount of protein in the urine; it begins after 20 weeks of pregnancy and influences the risk of poor outcomes for both mother and baby; risk factors include obesity, prior hypertension, older age, and diabetes mellitus.
182
Glossary (of Terms and Definitions)
Prevalence In epidemiology, the proportion of a particular population found to be affected by a medical condition; usually expressed as a fraction, percentage, or as the number of cases per 10,000 or 100,000 people. Proinsulin The prohormone precursor to insulin made in the pancreatic beta-cells, and encoded by the INS gene. Pyelonephritis Inflammation of the kidney, usually due to a bacterial infection; risk factors include sexual intercourse, prior urinary tract infections, diabetes, structural problems of the urinary tract, and use of spermicides. Resistin Also called adipose tissue-specific secretory factor (ASDF); a cysteine-rich adipose-derived peptide hormone encoded by the RETN gene that is believed to be involved in obesity and type 2 diabetes mellitus. Retinopathy Any damage to the retina of the eyes, which may cause vision impairment; it often refers to retinal vascular disease, or damage caused by abnormal blood flow; there are proliferative and nonproliferative types, and retinopathy is often related to diabetes or hypertension. Retroperitoneal Located behind a peritoneum of the body; organs are retroperitoneal if they have peritoneum on their anterior side only. Rhabdomyolysis A condition in which damaged skeletal muscle breaks down rapidly; it may damage the kidneys and lead to kidney failure. Ribose A pentose monosaccharide (simple sugar) with derivatives, such as ATP and NADH, that play central roles in metabolism. Saturated fatty acids Forms of carboxylic acids that contain no double bonds between the carbon atoms, being saturated with hydrogen; they cannot be broken down in the body, so they collect and are stored; examples include lauric, myristic, palmitic, and stearic acids; sources include dairy products, fatty meats, and oils. Schwann cells The principal glia of the peripheral nervous system (PNS), supporting neurons; they include satellite cells, olfactory ensheathing cells, enteric glia, glia at sensory nerve endings; they may be myelinating or nonmyelinating. Secretagogues Substances that cause other substances to be secreted; examples include gastrin, histamine, acetylcholine, sulfonylureas, and angiotensin II. Secretin A peptide hormone that regulates water homeostasis in the body, and affects the duodenum by regulating secretions in the stomach, pancreas, and liver; it is encoded by the SCT gene, and also stimulates bile production, emulsifying dietary fats so that pancreatic lipase can act upon them. Serotonergic Pertaining to or affecting serotonin, a neurotransmitter; examples of serotonergic agents include serotonin receptor agonists and antagonists, reuptake inhibitors, and releasing agents. Sialic acid A generic term for the nitrogen or oxygen substituted derivatives of neuraminic acid, a monosaccharide with a ninecarbon backbone; also, another name for N-acetyl-neuraminic acid. Soluble fiber The type of fiber that dissolves in water and is easily fermented in the colon into gases and short-chain fatty acids; it delays gastric emptying, resulting in an extended feeling of fullness. Somatostatin Also called growth hormone-inhibiting hormone (GHIH), a peptide hormone with endocrine effects on neurotransmission and cell proliferation via interaction with G protein-coupled somatostatin receptors, and inhibition of the release of many secondary hormones; it inhibits insulin and glucagon secretion. Soto syndrome Also called Sotos syndrome, cerebral gigantism, or Sotos-Dodge syndrome; a rare genetic disorder characterized by excessive growth in the first few years of life; there may also be autism, intellectual disability, delayed development, hypotonia, and speech impairments. Sphingolipid A type of lipid with a backbone of sphingoid bases; a set of aliphatic amino alcohol including sphingosine; they are important in signal transmission and cell recognition. Sphingomyelin A type of sphingolipid in animal cell membranes, especially in the myelin sheath surrounding some nerve cell axons; it participates in many signaling pathways. Sphingosine An 18-carbon amino alcohol with an unsaturated hydrocarbon chain that forms a main part of sphingolipids. Spirometry The most common pulmonary function test, which measures lung function—especially the volume and flow of air that can be inhaled and exhaled. Splenic artery The blood vessel that supplies oxygenated blood to the spleen, branching from the celiac artery; it follows a course superior to the pancreas. Splenic vein The blood vessel that drains blood from the spleen, stomach fundus, and part of the pancreas. Starch Also called amylum; a polymeric carbohydrate consisting of many glucose units joined by glycosidic bonds; the most common carbohydrate in human diets; found in large amounts in potatoes, wheat, corn, rice, and cassava. Steroids Biologically active organic compounds that are important components of cell membranes, and act as signaling molecules; examples of steroids include the sterols, which include cholesterol, estradiol, testosterone, and dexamethasone. Sulfonylureas Organic compounds used in the management of type 2 diabetes that act by increasing insulin release form the pancreatic beta-cells; examples include tolbutamide, glyburide, glipizide, and glimepiride. Superior mesenteric artery The blood vessel arising from the anterior surface of the abdominal aorta, just inferior to the origin of the celiac trunk; it supplies the intestine from the lower duodenum through two-thirds of the transverse colon, as well as the pancreas. Susceptibility genes Alterations of genes that increase an individual’s predisposition, or susceptibility, to a certain disease or disorder.
Glossary (of Terms and Definitions)
183
Synaptic clefts Small spaces adjacent to neurons, into which neurotransmitter molecules are released from synaptic vesicles. Thermogenesis The process of heat production in the body. Thiazolidinediones Also called glitazones; heterocyclic compounds used in the treatment of type 2 diabetes; they activate peroxisome proliferator-activated receptors. Thrifty gene hypothesis Also called Gianfranco’s hypothesis; an explanation of why certain modern populations are prone to type 2 diabetes mellitus; it has been expanded to include obesity, and is based on genes that can cause fat to deposit when there is plenty of food, to account for later periods of food shortage. Trans fatty acids Also called trans fat or unsaturated fatty acids; they are linked to increased risk of coronary artery disease. Transaminated The use of a chemical reaction to transfer an amino acid group to a ketoacid group, forming new amino acids; it utilizes enzymes called transaminases or aminotransferases. Transmucosal The absorption of a substance through the mucous membranes; examples include membranes of the nose, tongue and mouth, vagina, etc. Triacylglycerol Also known as triglyceride or triacylglycerides; an ester derived from glycerol and three fatty acids; the main constituents of body fat; divided primarily into saturated and unsaturated types. Triglycerides Also called triacylglycerols or triacylglycerides. Trisaccharides Oligosaccharides with three monosaccharides and two connecting glycosidic bonds; examples include maltotriose, melezitose, and raffinose. Tumor necrosis factor-alpha (TNFα) Also called cachexin or cachectin; a cytokine involved in systemic inflammation, involved in the acute phase reaction; mostly produced by activated macrophages; it regulates immune cells. Type 1 diabetes mellitus A form of diabetes in which very little or no insulin is produced by the pancreas; this results in high glucose levels in the body, classic symptoms of frequent urination, increased thirst, increased hunger, and weight loss; it is caused by genetic and environmental factors and involves autoimmune destruction of the insulin-producing beta-cells of the pancreas. Type 2 diabetes mellitus A form of diabetes characterized by high blood glucose insulin resistance, and a relative lack of insulin; it primarily occurs because of obesity and lack of exercise; long-term complications include heart disease, stroke, diabetic retinopathy, kidney failure, and poor blood flow to the limbs. Uncoupling protein (UCP-1) Also called thermogenin; it is found in the mitochondria of brown adipose tissue and used to generate heat by nonshivering thermogenesis; it is very important to prevent heat loss in neonates. Unsaturated fatty acids Those in which there is at least one double bond within the fatty acid chain; they may be monounsaturated or polyunsaturated fatty acids, which can replace saturated fat in the diet; this helps reduce levels of total cholesterol and LDL cholesterol in the blood. Vascular dementia Also called multi-infarct dementia or vascular cognitive impairment; it is caused by alterations in the brain’s blood supply, usually from a series of minor strokes; this leads to worsening cognitive decline over time. Vasoactive intestinal peptide (VIP) Also called vasoactive intestinal polypeptide, it is vasoactive in the intestines; it stimulates heart contractility, causes vasodilation, increases glycogenolysis, lowers arterial blood pressure, and relaxes muscles; this peptide is encoded by the VIP gene. Vitiligo A condition in which a loss of melanocytes results in smooth, white patches in the midst of normally pigmented skin. White adipose tissue Also called white fat; in healthy people, it is composed of 20% of male body weight and 25% of female body weight; it is used as a storage form of energy; upon insulin release from the pancreas, this type of fat’s insulin receptors causes a dephosphorylation cascaded, inactivating lipase. Xanthomas Deposits of yellowish cholesterol-rich material anywhere on the body, due to various diseases; they may be related to hyperlipidemia, chronic biliary tract obstruction, and primary biliary cirrhosis. ZAC gene The zinc-activated ion channel gene, also called the ZACN gene; zinc-activated ion channel mRNA is expressed in the prostate, thyroid, trachea, lung, brain, spinal cord, skeletal muscle, heart, placenta, pancreas, liver, kidney, and stomach. Zedoary seed A herb that was used by the Persian physician Avicenna, along with the flowing plant called lupine and the herb trigonella (fenugreek) to produce a significant reduction in excretion of sugar for diabetic patients. ZFP57 gene The gene that encodes the zinc finger protein 57 homolog or ZFP57; this protein is believed to function as a transcriptional repressor; mutations of the ZFP57 gene may be linked to transient neonatal diabetes mellitus. Zinc transporter 8 autoantibody The antibody to the insulin secretory granule zinc transporter (ZnT8), which is a producer of the SLC30A8 gene; many people with type 1 diabetes have this antibody, while those with type 2 or gestational diabetes do not; the first such antibody is now being used to diagnose type 1 diabetes. Zymogens Also called proenzymes; they are inactive precursors of enzymes that require biochemical changes in order to act.