Clinical Chemistry

Alanine aminotransferase (ALT)

an enzyme present in high concentration in the liver and measured to assess liver function; formerly called SGPT

albumins

the most abundant protein in normal plasma

Alkaline Phospatase (ALP)

an enzyme widely distributed in the body, especially in the liver and bone

analyte

a chemical substance that is the subject of chemical analysis

Aspartate aminotransferase (AST)

an enzyme present in many tissues, including cardiac, muscle, and liver, and measured to assess liver function; formerly called SGOT

bilirubin

product formed to breakdown hemoglobin

blood urea nitrogen (BUN)

a test measuring urea nitrogen in the blood

B-type natriuretic peptide (BNP)

a peptide hormone released primarily from the ventricles of the heart and used as a marker for cardiac function

cardiovascular disease

a disease of the heart and blood vessels

coronary heart disease

the clogging of the vessels that nourish the heart muscle; the leading cause of death in many developed countries

c-reactive protein

one of the acute phase proteins found in plasma and inflammation

creatine kinase

an enzyme present in large amounts in brain tissue and heart and skeletal muscle and a form of which is measured to aid in diagnosing heart attack

creatinine

a breakdown product of creatine that is normally excreted in the urine

Electrolytes

the cations and anions important in maintaining fluid and acid-base balance

gamma-glutamyltransferase (GGT)

an enzyme present in liver, kidney, pancreas, and prostate, and measured to assess liver function

globulins

a heterogeneous group of serum proteins with varied functions

glomerular filtration rate (GFR)

an estimate of the volume of blood that passes through the glomeruli of the kidney per minute

gout

a painful condition in which blood uric acid is elevated and urates precipitate in joints

HDL cholesterol

good. high density lipoprotein. high protein, low fat

homeostasis

equilibrium

homocysteine

an amino acid, elevated blood levels of which are associated with increased risk for vascular and cardiovascular disease

hypercalcemia

excessive calcium in the blood

hyperlipidemia

excessive fat in the blood

hyperthyroidism

excessive activity of the thyroid gland

hypoalbuminemia

low albumin levels in the blood

hypocalcemia

deficient calcium in the blood

hypothyroidism

underactivity of the thyroid gland

Lactate dehydrogenase (LDH)

an enzyme widely distributed in the body and measured to assess liver function

LDL cholesterol

bad. low density lipoprotein. low protein, high fat

lipids

fats and oils

Thyroid Stimulating Hormone (TSH)

stimulates thyroid gland

thyroxine

Thyroid hormone, commonly called T4

triglycerides

the major storage form of lipids; lipid molecules formed from glycerol and fatty acids

triiodothyronine

one of the thyroid hormones, commonly called T3

troponins

intracellular proteins that are present in skeletal and heart muscle and are released when muscle is injured

uric acid

a breakdown product of nucleic acids

VLDL cholesterol

very low density lipoprotein fraction of blood cholesterol

cerebrospinal fluid (CSF)

Fluid surrounding the brain and spinal cord

diurnal

having a daily cycle

lipemic

having a cloudy appearance because of excess lipid content

order of draw

a standard order of filling blood collection tubes when obtaining blood from a venipuncture in order to avoid cross-contamination between tubes

pericardial fluid

small amount of lubricating fluid in heart.

plasma

liquid portion of blood which blood cells are suspended

pleural fluid

liquid that surrounds the lungs

serum

liquid portion of the blood that remains after clotting

absorbance

The amount of light absorbed by a sample

amperometry

measurement of the current flow produced by an oxidation-reduction reaction

Beer's law

explains the relationship between absorbance, at a given wavelength and concentration, A = εbc

ion-selective electrode

an electrode sensitive to the concentration of a particular ion in solution

light spectrum

How light is absorbed or reflected

monochromator

Isolates specific or individual wavelength of light

nephelometry

measures light scattered

percent transmittance

the percentage of light that makes it through the column

reflectance photometer

an instrument that measures the light reflected from a colored reaction product

solid-phase chemistry

An analytical method in which the sample is added to a strip or slide containing all reagents for the procedure in dried form

spectrophotometer

An instrument that measures the proportions of light of different wavelengths absorbed and transmitted by a pigment solution.

alpha cell

secretes glucagon

beta cell

secretes insulin

cellular respiration

the process by which cells use oxygen to produce energy from food

chromogen

a substance that becomes colored when it undergoes a chemical change

diabetes mellitus

a disorder of carbohydrate metabolism characterized by a state of hyperglycemia resulting from insulin deficiency

glucagon

increase blood glucose

gluconeogenesis

production of glucose from noncarbohydrate sources

glucose dehydrogenase

enzyme that converts glucose to gluconolactone and is used in glucose analytical methods

glucose oxidase

An enzyme that converts glucose to gluconic acid and that is used in glucose analytical methods

glycated hemoglobin (GHb)

see hemoglobin A1c

glycogen

storage form of glucose

glycogenesis

conversion of glucose to glycogen

glycolysis

energy production as a result of the metabolic breakdown of glucose

hemoglobin A1c

hemoglobin modified by the binding of glucose to the beta-globin chains of hemoglobin

hexokinase

an enzyme that converts glucose to glucose-6-phosphate and that is used in glucose analytical methods

hypoglycemia

low blood sugar

hyperglycemia

high blood sugar

insulin

Hormone produced by the pancreas that helps to decrease blood sugar.

islets of Langerhans

cell clusters in the pancreas that form the endocrine part of that organ

Oral Glucose Tolerance Test (OGTT)

analysis of blood glucose at timed intervals following ingestion of a standard glucose dose

peroxidase

breaks down hydrogen peroxide

postprandial

after eating

proinsulin

a precursor of insulin

atherosclerosis

hardening of the arteries

chylomicrons

fat droplets covered in protein that diffuse into capillaries in small intestine

Coronary Heart Disease (CHD)

the buildup of a waxy substance called plaque in the arteries of the heart

endogenous

produced from within; due to internal causes

exogenous

originating from outside the body

myocardial infarction (MI)

heart attack caused by obstruction of the blood supply to or within the heart

acidosis

pH below 7.35

alkalosis

pH above 7.45

anion gap

a mathematical calculation of the difference between the cations and anions measured in the electrolyte assay

guaiac

a chemical derived from the resin of a tree of the genus Guaiacum

malignant

cancerous

occult

concealed or hidden

polyp

growth of tissue projecting from a mucous membrane