Download Glossary of Medical Terms - WiRED International—Medical

Glossary A Acute: rapid in onset, aggressive; short‐term initial stage of a disease. Contrast with chronic. Adherence: refers generally to the ability to follow a prescribed treatment regimen, including correct dosage, number of doses per day, and dietary restrictions. Allergy If you have an allergy to something (such as pollen or a medicine), your body always overreacts to it. The reaction happens because your immune system (your body's system for fighting infection) is too sensitive to it. Amino Acid: an organic compound that is a basic structural unit of peptides and proteins. There are over 100 amino acids, eight of which are essential for human metabolism. Anecdotal: refers to evidence based on reports of specific individual cases rather than controlled, clinical studies. Anemia: the reduced ability of blood to carry oxygen due to a low hemoglobin level, an abnormality, or a reduced number of red blood cells. Symptoms include fatigue and weakness. Antibody (AB, Immunoglobulin, IG): an immunoglobulin protein secreted by activated plasma cells, which evolve from B cells. Antibodies are present throughout the blood and tissues; they are produced in response to stimulation by foreign antigens as part of the body's defense against disease. Specific antibodies bind to and act upon specific antigens; the antigen/antibody reaction forms the basis of humoral (TH2) immunity. Neutralizing antibodies destroy or inactivate infectious agents, while enhancing antibodies promote infection. Antigen: any agent or substance that stimulates an immune response. Antigens are often foreign microorganisms such as bacteria or viruses, or the substances they produce. Antiretroviral: an agent that suppresses the activity or replication of retroviruses such as HIV. Antiretroviral drugs interfere with various stages of the virus' life cycle, for example, reverse transcriptase inhibitors (e.g., AZT, ddI, 3TC) and protease inhibitors (e.g., saquinavir, ritonavir). Atrophy: progressive degeneration, wasting, or decrease in size, especially the loss of muscle tissue. Autoimmune Response (Autoimmunity): a condition in which an individual's immune system fails to recognize its own biochemical markers as being "self" and attacks body tissues as if they were foreign matter, possibly leading to autoimmune diseases such as lupus or rheumatoid arthritis. AIDS (Acquired Immunodeficiency Syndrome): A condition characterized by a defect in the body's natural immunity to diseases. Individuals who suffer from it are at risk for severe illnesses that are usually not a threat to anyone whose immune system is working properly. Addiction: A chronic, relapsing disease characterized by compulsive drug‐seeking and abuse and by long‐lasting chemical changes in the brain. Adrenal glands: Glands, located above each, kidney that secrete hormones, e.g., adrenaline. Amphetamine: Stimulant drugs whose effects are very similar to cocaine. Amyl nitrite: A yellowish oily volatile liquid used in certain diagnostic procedures and prescribed to some patients for heart pain. Illegally diverted ampules of amyl nitrite are called "poppers" or "snappers" on the street. Anabolic effects: Drug‐induced growth or thickening of the body's nonreproductive tract tissues‐
including skeletal muscle, bones, the larynx, and vocal cords‐and decrease in body fat. Analgesics: A group of medications that reduce pain. Anesthetic: An agent that causes insensitivity to pain and is used for surgeries and other medical procedures. Androgenic effects: A drug's effects upon the growth of the male reproductive tract and the development of male secondary sexual characteristics. Aplastic anemia: A disorder that occurs when the bone marrow produces too few of all three types of blood cells: red blood cells, white blood cells, and platelets. Axon terminal: The structure at the end of an axon that produces and releases chemicals (neurotransmitters) to transmit the neuron's message across the synapse. Axon: The fiber‐like extension of a neuron by which the cell carries information to target cells. Abscess: A localized collection of pus caused by suppuration buried in tissues, organs or confined spaces. Usually due to an infective process. Achalasia: Constriction of the lower portion of the food pipe (oesophagus) due to inability of the sphincter muscles to relax. Symptoms include difficulty swallowing, chest pain, vomiting and heartburn. Achlorhydria: The absence of hydrochloric acid from the gastric juice. Adenocarcinoma: One of the most common primary lung carcinomas, which appears to be increasing in incidence, and now may be more common than squamous cell carcinoma. This tumor is usually peripheral in location and often is associated with scarring, leading to pleural puckering. This neoplasm may vary in histologic appearance with some tumors having well‐formed glands, others having a papillary architecture, and yet others being less differentiated and having a solid appearance. Adventitia: The outermost connective tissue covering of any organ, vessel, or other structure not covered by a serosa; instead, the covering is properly derived from without (i.e., from the surrounding connective tissue) and does not form an integral part of such organ or structure. Aflatoxins: A harmful substance made by certain types of mold (Aspergillus flavus and Aspergillus parasiticus) that is often found on poorly stored grains and nuts. Consumption of foods contaminated with aflatoxin is a risk factor for primary liver cancer. Agnogenic: Synonym: idiopathic—refers to a disease or condition of unknown cause or origin. Algorithm: The term algorithm (pronounced AL‐go‐rith‐um) is a procedure or formula for solving a problem. Amitotic: Relating to or marked by amitosis ‐‐ an unusual form of nuclear division, in which the nucleus simply constricts, rather like a cell without chromosome condensation or spindle formation. Partitioning of daughter chromosomes is haphazard. Amoeboid: Resembling an amoeba specifically in moving or changing in shape by means of protoplasmic flow. Ampulla: A saccular anatomic swelling or pouch. Amylase: Enzyme, also called diastase. It is found in both plants and animals. Anal Verge: The external or distal boundary of the anal canal. Anaplasia: Lack of differentiated features in a cancer cell, characterized by cellular pleomorphism (variation in size and shape of cells and their nuclei), enlarged and hyperchromatic nuclei, prominant nucleoli, atypical mitoses, and bizarre cells, including giant cells. Anastomosis: An opening created by surgical, traumatic or pathological means between two normally separate spaces or organs. Anemia: Reduction in total circulating red blood cell mass, diagnosed by a decrease in hemoglobin concentration. Anemic patients have low oxygen‐carrying capacity of the blood, with resultant tissue hypoxia. The clinical symptoms are related to the severity of the anemia, and may include pallor, tachycardia, angina, light‐headedness and fatigue. Anemia may be due to increased blood loss, decreased red blood cell production, or increased red blood cell destruction. Aneuploid: Having a chromosome number that is not an exact multiple of the haploid number. Angiosarcoma: Angiosarcomas are uncommon malignant neoplasms characterized by rapidly proliferating, extensively infiltrating anaplastic cells derived from blood vessels and lining irregular blood‐filled spaces. Specialists apply the term angiosarcoma to a wide range of malignant endothelial vascular neoplasms that affect a variety of sites. Angiosarcomas are aggressive and tend to recur locally, spread widely, and have a high rate of lymph node and systemic metastases. Anomaly: A marked deviation from the normal standard, especially as a result of congenital defects. Anorexia: The uncontrolled lack or loss of the appetite for food. Antibodies: Antibodies are special proteins that are part of the body's immune system. White blood cells make antibodies to neutralize harmful germs, or other foreign substances, called antigens. Antibodies are "good guys" that fight inside your body, protecting you from "bad guys" like bacteria and viruses. Antigen: An antigen is a substance that can trigger an immune response, resulting in production of an antibody as part of the body's defense against infection and disease. Many antigens are foreign proteins (those not found naturally in the body). An allergen is a special type of antigen which causes an IgE antibody response. Antrectomy: Removal of the walls of an antrum. Antrum: A general term for cavity or chamber which may have specific meaning in reference certain organs or sites in the body. The antrum of the stomach (gastric antrum) is a portion before the outlet which is lined by mucosa which does not produce acid. The paranasal sinuses can be referred to as the frontal antrum, ethmoid antrum, and maxillary antrum. Aorta: The largest artery in the body which has its origin at the heart. It gives off branches to the extremities, neck and major organs for the purpose of supplying oxygenated blood. Aplastic: Lacking in cell production, as in aplastic anaemia. Ascites: Abnormal buildup of fluid in the abdomen. Ascites can occur as a result of severe liver disease. Atelectasis: Absence of air in the alveolar spaces resulting in incomplete expansion of the lungs at birth or collapse of the lungs of an adult. Atrophy: A wasting away, a diminution in the size of a cell, tissue, organ or part. Atypia: State of being not typical. Axon: A usually long and single nerve‐cell process that usually conducts impulses away from the cell body. B Baseline: an initial or known value (e.g., CD4 cell count, HIV viral load) against which later measurements can be compared. Bilirubin: levels are measured to gauge the health of the liver. Bone: Bone is the substance that forms the skeleton of the body. It is composed chiefly of calcium phosphate and calcium carbonate . It also serves as a storage area for calcium, playing a large role in calcium balance in the blood. See the entire Bone Marrow: the soft, spongy tissue in the interior of certain bones (e.g., the long bones of the limbs). Bone marrow contains stem cells and is the site of blood cell production. Branched‐Chain DNA Assay (bDNA, Quantiplex HIV RNA Assay): a test that measures the amount of virus (viral load) in plasma or tissue using a chemical signal, visible as light, that is produced by viral RNA. Breakthrough: a condition that develops despite measures to prevent it (e.g., PCP that occurs while taking a prophylactic drug). Also, a rise in viral load after it has fallen due to anti‐HIV therapy (virologic breakthrough). Benzene: A volatile liquid solvent found in gasoline. Bind: The attaching of a neurotransmitter or other chemical to a receptor. The neurotransmitter is said to "bind" to the receptor. Brainstem: The major route by which the forebrain sends information to, and receives information from, the spinal cord and peripheral nerves. Butane: A substance found in lighter fluid. Butyl nitrite: An illegal substance that is often packaged and sold in small bottles; also referred to as "poppers." Bacteria Bacteria are single‐celled life forms visible only through a microscope. Bacteria live all around us and within us. Our lives are closely intertwined with theirs, and the health of our planet depends very much on their activities. Barium enema A radiographic diagnostic procedure that involves the introduction of a barium containing contrast material into the lower gastrointestinal tract via the anus. X‐rays taken after instillation of the barium will outline the course and anatomy of the lower GI tract. Barrett esophagus A change in the cells of the tissue that lines the bottom of the esophagus. The esophagus may become irritated when the contents of the stomach back up (reflux). Reflux that happens often over a period of time can lead to Barrett's esophagus. Basal & Squamous Cell Carcinoma Most cancer registries in North America do not register cases of basal and squamous cell carcinoma. Most often, basal and squamous cell carcinomas pose little harm to the individuals if they are detected early and treated properly. Mortality from basal and squamous cell carcinoma is low. Therefore, with our limited public health dollars, and because there are so many diagnoses of basal and squamous cell carcinoma which rarely are serious enough to cause mortality, most registries elect to not register these skin tumors. Basement membrane Basement membrane is a structure that supports an overlying epithelium or endothelium. Keratinocytes, glandular cells, and endothelial cells reside on basement membranes. Basement membrane consists of an electron dense membrane called basal lamina, about 300‐700 angstrom in thickness, and an underlying network of reticular collagen fibrils which average 300 angstrom in diameter. This network is 0.1‐2 micron in thickness. Basophil Basophils make up less than 1% of your white blood cells. They are active in inflammation. Basophils contain histamine and heparin. Benzene A colorless and flammable toxic liquid used in organic synthesis, as a solvent, and as a motor fuel. Exposure to benzene can increase the risk of cancer and lead to anemia and a decrease in blood platelets. B‐cells B‐cells play an important role in humoral immunity because they synthesize and secrete antibodies which protect us from infection, viruses, etc. Biopsy A procedure used to remove cells or tissues in order to look at them under a microscope to check for signs of disease. Billroth operation I (Billroth I anastomosis) Excision of the pylorus with end‐to‐end anastomosis of stomach and duodenum. Return to Top | Close Window Billroth operation II (Billroth II anastomosis) Resection of the pylorus with the greater part of the lesser curvature of the stomach, closure of the cut ends of the duodenum and stomach, followed by a gastrojejunostomy. Bloom Syndrome Congenital telangiectatic erythema, primarily in butterfly distribution, of the face and occasionally of the hands and forearms, with sensitivity of skin lesions and dwarfism with normal body proportions except for a narrow face and dolichocephalic skull; chromosomes are excessively fragile; autosomal recessive inheritance. BPH (Benign Prostatic Hyperplasia) A benign condition in which an overgrowth of prostate tissue pushes against the urethra (which passes through the prostate) and the bladder, blocking the release of urine. BRCA1 BRCA1 or "Breast Cancer 1," is a genetic mutation that is present in about two‐thirds of heritable breast cancers and a smaller number of heritable ovarian cancers. Only about 5% of the female breast cancer in the world is attributable to having the BRCA1 mutation. BRCA2 BRCA2 or "Breast Cancer 2," is a genetic mutation that is present in both male and female heritable breast cancer, heritable ovarian cancer, and heritable prostate cancer. Less than 5% of cancers of the male and female breast, ovary, and prostate are attributable to the BRCA2 mutation. Brenner tumor Brenner tumors are comprised of solid to partly cystic epithelial nests surrounded by stroma composed of bundles of tightly packed spindle‐shaped cells. The epithelial cells are polygonal and of squamoid type, with pale, eosinophilic cytoplasm and oval nuclei with distinct nucleoli and longitudinal grooving, which is commonly described as "coffee‐bean" in appearance. Burkitt's Lymphoma Burkitt's lymphoma is a solid tumor of B lymphocytes, the lymphocytes that the immune system uses to make antibodies. Burkitt's lymphoma is a form of cancer that primarily affects children living in certain areas of Africa. Burkitt's lymphoma is also found in North America, but it is rare. By‐pass Surgical formation of a passage (anastomosis) between two normally distinct spaces or organs. For example, a shunt to divert blood from one part of the body to the other is a by‐pass. A colostomy to short circuit the GI tract, when there is an obstruction of the colon, is a by‐pass. C CD4 Cell: a type of white blood cell that carries the CD4 cell surface receptor and helps the body fight infection. CD4 cells release cytokines (chemical messengers) that coordinate a broad range of immune system activities including killer cell activation and antibody production. See also memory T cell. CD4 Cell Percentage: the number of CD4 cells compared with the number of all lymphocytes. Cell percentage is a more consistent and reliable measure than absolute cell count. Normal CD4 cell percentages are usually 30‐40% of all lymphocytes. Cesarean Delivery (Cesarean Section, C Section): a delivery procedure that involves making an incision through the abdominal wall to permit the removal of an infant from the uterus. Chemotherapy: the use of chemicals or drugs to treat disease; the term is typically used to refer to cancer treatment. Chromosome: a structure of compact, intertwined molecules of DNA (deoxyribonucleic acid) found in the nucleus of cells which carry the cell's genetic information. Humans normally have 46 chromosomes. See DNA. Chronic: less intense, slow, persisting over a long period. Contrast with acute. Cirrhosis: a condition in which the liver becomes scarred, fibrous, and filled with fat, thus reducing its ability to function. Causes include infection (e.g., hepatitis) and excessive alcohol consumption. Cofactor: a factor (e.g., substance, microorganism, environmental condition) that influences the progression of a disease or the action of a disease‐causing agent. Cohort: a group of individuals in a study who share a demographic, clinical, or other statistical characteristic (e.g., age, study site). Collagen: a fibrous protein that makes up connective tissue. Cytokine: an intercellular hormone or chemical messenger protein (e.g., tumor necrosis factor, interleukin) released by white blood cells (e.g., macrophages, T cells). Cytokines facilitate communication among immune system cells and between immune system cells and the rest of the body. See also interferon. Cytomegalovirus (CMV): a herpesvirus that occurs in healthy individuals without causing symptoms. In immunocompromised individuals (usually with CD4 cell counts below 50 cells/mm3), CMV may cause serious illness including retinitis (inflammation of the retina), pneumonia, colitis (inflammation of the large bowel), and encephalitis. CMV infection of a pregnant woman may lead to congenital abnormalities in the newborn. CMV may be treated with ganciclovir, foscarnet, or cidofovir. Cannabinoid receptor: The receptor in the brain that recognizes anandamide and THC, the active ingredient in marijuana. Cannabinoids: Chemicals that help control mental and physical processes when produced naturally by the body and that produce intoxication and other effects when absorbed from marijuana. Cannabis: The botanical name for the plant from which marijuana comes. Carcinogen: Any substance that causes cancer. Cardiovascular system: The heart and blood vessels. Cell body (or soma): The central structure of a neuron, which contains the cell nucleus. The cell body contains the molecular machinery that regulates the activity of the neuron. Central nervous system: The brain and spinal cord. Cerebellum: A portion of the brain that helps regulate posture, balance, and coordination. Cerebral cortex: Region of the brain responsible for cognitive functions including reasoning, mood, and perception of stimuli. Cerebral hemispheres: The two specialized halves of the brain. The left hemisphere is specialized for speech, writing, language, and calculation; the right hemisphere is specialized for spatial abilities, face recognition in vision, and some aspects of music perception and production. Cerebrum: The upper part of the brain consisting of the left and right hemispheres. Chloroform: A colorless volatile liquid used as a medical anesthetic gas. Chronic: Refers to a disease or condition that persists over a long period of time. Coca: The plant, Erythroxylon, from which cocaine is derived. Also refers to the leaves of this plant. Cocaethylene: A substance created in the body when cocaine and alcohol are used together; chemically similar to cocaine. Cocaine: A highly addictive stimulant drug derived from the coca plant that produces profound feelings of pleasure. Crack: "Slang" term for a smokeable form of cocaine. Craving: A powerful, often uncontrollable desire for drugs. Cyclohexyl nitrite: A chemical found in substances marketed as room deodorizers. CA 125 (Cancer Antigen 125) CA 125 is a protein made by certain cells in the body which include those of the uterus, uterine tubes, cervix, abdomen, and chest ( pleura and lungs ). Elevated CA 125 can be caused by many conditions such as peritonitis, pleuritis, menstruation, pregnancy, endometriosis, liver disease, benign ovarian growths, and by cancers of the uterine tubes, endometrium, lung, breast, and gastrointestinal tract. Cachexia A profound and marked state of constitutional disorder, general ill health and malnutrition. Calcium A silver‐white bivalent metallic element of the alkaline‐earth group occurring only in combination. Cancer Cancer is a group of more than 100 different diseases. Benign tumours are not cancer; malignant tumours are cancer. Most cancers are named for the type of cell or the organ in which they begin. When cancer spreads (metastasizes), the new tumour has the same name as the original (primary) tumour Cancer Control Cancer Control is the conduct of research and the translation of knowledge from research into strategies and actions to prevent cancer and to increase survival and quality of life for those touched by cancer. A simplified definition of "cancer control" is: Any activity that reduces the morbidity (sickness, disease) or mortality (death) from cancer. Cancer Prevention Cancer prevention research involves the development and evaluation of strategies for reducing cancer incidence. Such strategies could be aimed at preventing the initiation of the neoplastic process or at avoiding the progression to malignancy of already initiated cells. These efforts, which may be multidisciplinary and multifactorial, can involve a broad range of studies at the molecular, cellular, organismal and population levels. Carbohydrate Any of various neutral compounds of carbon, hydrogen, and oxygen (as sugars, starches, and celluloses) most of which are formed by green plants and which constitute a major class of animal foods. Carcinoid tumor A small tumor (benign or malignant) arising from the mucosa of the gastrointestinal tract; usually associated with excessive secretion of serotonin. Carcinogenesis Process that leads to formation of cancer from normal cells or tissues. Carcinogens Carcinogens are agents that can cause cancer. Carcinoma Carcinoma is a cancer found in body tissues that cover or line surfaces of organs, glands, or body structures. Casefinding Casefinding is a system for locating every patient ‐‐ inpatient or outpatient, public or private ‐‐ who is diagnosed and/or treated with a reportable malignancy. Casefinding Cycle Identifying source documents; determine reporting methods (active, passive, or a combination);linking the identified cases Monitoring completeness of casefinding Catecholamine Any of various amines (as epinephrine, norepinephrine, and dopamine) that function as hormones or neurotransmitters or both. Cautery The application of a caustic substance, a hot instrument, an electric current, or other agent to destroy tissue. CEA (Carcino‐Embryonic Antigen) CEA is a protein produced in the fetus but not in normal adult life. Produced by some carcinomas, particularly of the colon, it is an insensitive marker of malignancy. CEA is an oncofetal antigen that is used as a tumor marker. Celiac Disease A disorder in children and adults; inability to tolerate wheat protein (gluten); symptoms include foul‐
smelling diarrhea and emaciation; often accompanied by lactose intolerance. Centriole A cylinder‐shaped organelle composed of microtubules and found in the nucleus of a cell. During nuclear division it forms the spindle, which ensures that the duplicated chromosomes are equally divided between the daughter cells. Cephalic Of or relating to the head. Chediak‐Higashi Syndrome A generalized cellular disorder which affects all granule‐containing cells resulting in recurrent infections and ocular, neurological, and skin manifestations. Chemotherapy Chemotherapy is the treatment of cancer with drugs that can destroy cancer cells. These drugs often are called "anticancer" drugs. Anticancer drugs destroy cancer cells by stopping them from growing or multiplying. Healthy cells can also be harmed, especially those that divide quickly. Harm to healthy cells is what causes side effects. These cells usually repair themselves after chemotherapy. Cholangiocarcinoma Cholangiocarcinoma is a malignant (cancerous) growth in one of the ducts that carries bile from the liver to the small intestine. Cholecystokinin A hormone secreted especially by the duodenal mucosa that regulates the emptying of the gallbladder and secretion of enzymes by the pancreas and that has been found in the brain. Choriocarcinoma The choriocarcinoma is a non‐seminomatous testicular germ cell tumor characterized by the presence of large cells which express human chorionic gonadotropin. This tumor metastasizes hematogenously early in its development. Chorion (adj. chorionic) The highly vascular outer embryonic membrane of reptiles, birds, and mammals that in placental mammals is associated with the allantois in the formation of the placenta. Chromatin A complex of nucleic acid and basic proteins (as histone) in eukaryotic cells that is usually dispersed in the interphase nucleus and condensed into chromosomes in mitosis and meiosis. Chromosome One of the linear or sometimes circular DNA‐containing bodies of viruses, prokaryotic organisms, and the cell nucleus of eukaryotic organisms that contain most or all of the genes of the individual. Chronic myelogenous leukemia (CML) Chronic myelogenous leukemia (CML) is a malignant cancer of the bone marrow that causes rapid growth of the blood forming cells (known as myeloid precursors) in the bone marrow, peripheral blood, and body tissues. Chyme The semifluid mass of partly digested food expelled by the stomach into the duodenum. Cilium (pl. cilia) A minute, short hairlike process often forming part of a fringe; especially : one on a cell that is capable of lashing movement and serves especially in free unicellular organisms to produce locomotion or in higher forms a current of fluid. Cirrohsis A chronic disease interfering with the normal functioning of the liver; the major cause is chronic alcoholism. Classification Scheme A logical system for the arrangement of knowledge. A fully developed classification scheme specifies categories of knowledge and provides the means to relate the categories to each other and to specify in the classification number all or the most important of the aspects and facets of a subject. Colposcope A magnifying and photographic device used as an aid in the diagnostic examination of the vaginal and cervical epithelia. Confidential Spoken or written in secret and intended to be kept secret. In the cancer registry, all identifiable data is considered to be confidential. Conization Surgery to remove a cone‐shaped piece of tissue from the cervix and cervical canal. Conization may be used to diagnose or treat a cervical condition. Also called cone biopsy. Connective Tissue The supporting or framework tissue of the body, formed of fibrous and ground substance with more or less numerous cells of various kinds; it is derived from the mesenchyme, and this in turn from the mesoderm; the varieties of connective tissue are: areolar or loose; adipose; dense, regular or irregular, white fibrous; elastic; mucous; and lymphoid tissue; cartilage; and bone; the blood and lymph may be regarded as connective tissues the ground substance of which is a liquid. Core Biopsy Similar to needle biopsy, but a larger needle is used because actual tissue is removed, rather than a tiny sampling of cells. A sample of the tumoris removed, but not the whole tumor. The types of core biopsies include ultrasound‐guided core biopsy and stereotactic biopsy. Corpus Callosum The great band of commissural fibers uniting the cerebral hemispheres of higher mammals including humans. Corpus luteum The zona granulosa and theca cells remaining in the ovary after ovulation and some surrounding capillaries and connective tissue evolve into the corpus luteum. Cortex The outer or superficial part of an organ or bodily structure (as the kidney, adrenal gland, or a hair); especially : the outer layer of gray matter of the cerebrum and cerebellum. Cranium The bones of the skull which contain the brain, the brain case. Crohn disease Crohn disease is an inflammatory bowel disease (IBD); it is the general name for diseases that cause inflammation in the intestines. Crohn disease causes inflammation in the small intestine. Crohn's disease usually occurs in the lower part of the small intestine, called the ileum, but it can affect any part of the digestive tract, from the mouth to the anus. Cryptorchidism A condition in which one or both testicles fail to move from the abdomen, where they develop before birth, into the scrotum. Cryptorchidism may increase the risk for development of testicular cancer. Also called undescended testicles. Cryosurgery A surgical technique that utilises freezing tissue to remove unwanted portions. CT A standard medical abbreviation for C omputerized T omography. Culdoscopy The introduction of a viewing tube through the end of the vagina into the cul‐de‐sac. The cul‐de‐sac is also called the rectouterine pouch, an extension of the peritoneal cavity between the rectum and back wall of the uterus. Cutaneous Pertaining to the skin, dermal, dermic. CXR A standard medical abbreviation for C hest X ‐ R ay. Cystic Relating to a cyst ‐‐ any closed cavity or sac that is lined by epithelium often contains liquid or semi‐
solid material. Cytogenetics The study of chromosomes, the visible carriers of DNA, the hereditary material. Cytogenetics is a fusion science due to joining of cytology (the study of cells) with genetics (the study of inherited variation). Cytology Cytology is the study of cells and how they function. Cytoplasm The protoplasm of a cell exclusive of that of the nucleus, it consists of a continuous aqueous solution and the organelles and inclusions suspended in it and is the site of most of the chemical activities of the cell. Cytotoxic Any substance which has the properties to harm or destroy cells. D Demographics: the characteristics of a population (e.g., sex, race, age, geographic location). Disc: Shortened terminology for an intervertebral disc, a disk‐shaped piece of specialized tissue that separates the bones of the spinal column. DNA (Deoxyribonucleic Acid): a molecule that encodes genetic information and is found in the nucleus of cells as a twisted double‐stranded chain. The particular sequence of four chemical building blocks (nucleotides) ‐‐ adenine, cytosine, guanine, and thymine ‐‐ that make up a DNA chain determines the unique genetic code of an individual. Dendrite: The specialized branches that extend from a neuron's cell body and function to receive messages from other neurons. Depressants: Drugs that relieve anxiety and produce sleep. Depressants include barbiturates, benzodiazepines, and alcohol. Dopamine: A brain chemical, classified as a neurotransmitter, found in regions of the brain that regulate movement, emotion, motivation, and pleasure. Drug: A chemical compound or substance that can alter the structure and function of the body. Psychoactive drugs affect the function of the brain, and some of these may be illegal to use and possess. Drug abuse: The use of illegal drugs or the inappropriate use of legal drugs. The repeated use of drugs to produce pleasure, to alleviate stress, or to alter or avoid reality (or all three). Data Set A data set is a named collection of data that contains individual data units organized (formatted) in a specific and prescribed way. Death Clearance The process of linking a file of known decedents against a cancer registry file in order to determine all deaths among registrants and to identify deaths from cancer among persons previously unknown to the registry. Dendrite Any of the usually branching protoplasmic processes that conduct impulses toward the body of a nerve cell. De novo Latin: new. Anew, afresh. A "trial de novo" is a retrial. Diapedesis Passage of blood cells (especially white blood cells) through intact capillary walls and into the surrounding tissue. Diaphragm The diaphragm is the primary muscle of inspiration. It is a thin, dome‐shaped sheet of muscle that inserts into the lower ribs. When it contracts, it pushes downward and spreads out, increasing the vertical dimension of the chest cavity and driving up abdominal pressure. This increase in pressure drives the abdominal contents down and out, which in turn increases the transverse size of the chest cavity. Diarrhea Frequent, loose, and watery bowel movements. Common causes include gastrointestinal infections, irritable bowel syndrome, medicines, and malabsorption. Diethylstilbestrol (DES) A drug given to pregnant women from the early 1940s until 1971 to help with common problems during pregnancy. The drug has been linked to cancer of the cervix or vagina in women whose mother took the drug while pregnant. Differential In performing the blood count, a total of 100 cells are counted. The percent of each type found in these 100 cells is the cell "differential" for each type. Differentiation In cancer, differentiation refers to how mature (developed) the cancer cells are in a tumor. Differentiated tumor cells resemble normal cells and grow at a slower rate than undifferentiated tumor cells, which lack the structure and function of normal cells and grow uncontrollably. Diploid Individual or cell having two complete sets of chromosomes. Disease Index A computerized listing of patients seen in a hospital (inpatient and outpatient) organized by discharge diagnosis code. For example: unspecified hypertension is coded 401.9 (in ICD‐9, but is I10 in ICD‐10) and malignant neoplasm of the central portion of the female breast is coded 174.1 (in ICD‐9, but is C50.1 in ICD‐10). Disease Registry An organized system for the collection, storage, analysis, and interpretation of data on persons with the particular disease of concern. Distal Remote, farther from any point of reference, opposed to proximal. Diverticulum A small sac‐like structure that sometimes forms in the walls of the intestines, diverticula can trap particles of food (especially small seeds and undigested grains) and become very inflammed and painful (this condition is called diverticulitis). DNA DNA (deoxyribonucleic acid) is a double‐stranded helix of nucleotides which carries the genetic information of a cell. It encodes the information for the proteins and is able to self‐replicate. Dorsal Pertaining to, or situated near, the back, or dorsum, of an animal or of one of its parts. Down Syndrome A combination of birth defects caused by the presence of an extra #21 chromosome in each cell of the body. Many children with Down syndrome also have congenital heart disease—usually atrioventricular canal defect. Dysphagia Difficulty in swallowing. Dysplasia Premalignant change characterized by alteration in the size, shape and organization of the cellular components of a tissue. E Estrogen: a female sex hormone; a natural or synthetic substance (e.g., estradiol, Premarin) that stimulates the development of female secondary sex characteristics and regulates the reproductive cycle in women. Estrogens are known to affect the immune system. Ecstasy (MDMA): A chemically modified amphetamine that has hallucinogenic as well as stimulant properties. Emphysema: A lung disease in which tissue deterioration results in increased air retention and reduced exchange of gases. The result is difficult breathing and shortness of breath. It is often caused by smoking. Endogenous: Something produced by the brain or body. Ether: A volatile liquid with a characteristic odor. Used as a medical anesthetic gas. Euphoria: A feeling of well‐being or elation. Echography Echography (ultrasound, ultrasonography or sonography) is a diagnostic test using high frequency sound waves that is utilized by many medical specialities. Electrolyte A substance that, when dissolved in a suitable solvent or when fused, becomes an ionic conductor. Emboli Material, usually blood clot but may be fat, bone fragment, nitrogen bubble or bullet, that travels through the circulation, eventually obstructing blood flow through a smaller calibre vessel (for example stroke, pulmonary embolism, central retinal artery occlusion). Embryo An egg that has been fertilized by a sperm and undergone one or more divisions. Endocrine A system in the body in which substances (hormones) are made and released (secreted) in the body. If the endocrine system is affected by certain drugs then there can be changes in hormones which can affect growth or sexual development and functions. Endocytosis Incorporation of substances into a cell by phagocytosis or pinocytosis. Endoplasmic Reticulum A system of interconnected vesicular and lamellar cytoplasmic membranes that functions especially in the transport of materials within the cell and that is studded with ribosomes in some places. Endoscopic Biopsy Endoscopic biopsy is done through an endoscope (a fiber optic cable for viewing inside the body) which is inserted into the body along with sampling instruments. The endoscope allows the physician to visualize the abnormality and guide the sampling. Endothelial Pertaining to or made up of endothelium. Endothelium An epithelium of mesodermal origin composed of a single layer of thin flattened cells that lines internal body cavities. Enzyme A protein that speeds up chemical reactions in the body. (CNet) Any of a group of chemical substances which are produced by living cells and which cause particular chemical reactions to happen while not being changed themselves. E.g., an enzyme in the saliva of the mouth starts the process of breaking down the food. Eosinophilia Elevated eosinophil count in the circulating blood. Commonly associated with chronic parasite infections. Epidermis The outer epithelial layer of the skin. Epithelium The covering of internal and external surfaces of the body, including the lining of vessels and other small cavities. Erythrocyte Red blood cell. Erythropoietin A glycoprotein hormone produced primarily by cells of the peritubular capillary endothelium of the kidney that is responsible for the regulation of red blood cell production. Estrogen Any of various natural steroids (as estradiol) that are formed from androgen precursors, that are secreted chiefly by the ovaries, placenta, adipose tissue, and testes, and that stimulate the development of female secondary sex characteristics and promote the growth and maintenance of the female reproductive system. Excisional Biopsy Also known as a surgical or open biopsy, the purpose of an excisonal biopsy is to attempt to remove the entire mass or a large portion of the mass. The tissue that is removed is then sent to the pathologist for diagnosis. Exocytosis The release of cellular substances (as secretory products) contained in cell vesicles by fusion of the vesicular membrane with the plasma membrane and subsequent release of the contents to the exterior of the cell. Exophthalmus An abnormal protrusion of the eyeball(s). F Fundus: the bottom or base of an organ (e.g., eye). Fever If you have a fever, your body temperature is above 37 degrees Celsius (98.6 degrees Fahrenheit). With a fever you often get other symptoms, such as shivering, headache or sweating. A fever is usually caused by an infection. Freshwater is water containing less than 1,000 milligrams per liter of dissolved solids, most often salt. Fluorinated hydrocarbons: Gases or liquids commonly found in refrigerants, fire extinguishers, solvents, and anesthetics. Freon is one class of fluorinated hydrocarbons. Forebrain: The largest division of the brain, which includes the cerebral cortex and basal ganglia. It is credited with the highest intellectual functions. Frontal lobe: One of the four divisions of each cerebral hemisphere. The frontal lobe is important for controlling movement and associating the functions of other cortical areas. Familial Polyposis Hereditary, autosomal dominant precancerous syndrome characterized by innumerable adenomatous polyps of the colon. Fanconi Anemia (congenital pancytopenia) A rare congenital anemia characterized by pancytopenia and hypoplasia of the bone marrow Fascia Fascia, a connective tissue, is the packing material of the body. It envelopes the muscles, bones and joints and holds us together supporting the body structure and giving us our shape. Fascia organizes and separates: it provides protection and autonomy for the individual muscles and viscera. It joins and bonds these separate entities and establishes spatial relationships. Chemically it is the collagen in the fascia that enables it to change. Fertilization The process of union of two gametes whereby the somatic chromosome number is restored and the development of a new individual is initiated. Fetus An unborn or unhatched vertebrate especially after attaining the basic structural plan of its kind; specifically : a developing human from usually three months after conception to birth. Fibroblast A connective‐tissue cell of mesenchymal origin that secretes proteins and especially molecular collagen from which the extracellular fibrillar matrix of connective tissue forms. Return to Top | Close Window Fibrosis Refers to the presence of scar tissue or collagen fibers in any tissue. In the liver, fibrosis or scarring of the liver damages the architecture and thus the functionality of the organ. Fibrosis, combined with the liver's ability to regenerate, causes cirrhosis (regeneration within the scar tissue). Return to Top | Close Window Fistula In medicine, a fistula is an abnormal channel that creates an open passageway between two bodily structures that do not normally connect. Flagellum A long tapering process that projects singly or in groups from a cell and is the primary organ of motion of many microorganisms. Flow Cytometry Analysis of biological material by detection of the light‐absorbing or fluorescing properties of cells or subcellular fractions such as chromosomes passing in a narrow stream through a laser beam. Flow cytometry is used with automated sorting devices to sort successive droplets of the stream into different fractions depending on the fluorescence emitted by each droplet. Foramen Magnum The opening in the skull through which the spinal cord passes to become the medulla oblongata. Fossa (pl. fossae) An anatomical pit, groove, or depression. Free Radicals An atom or a group of atoms with an unpaired electron. Radicals are unusually reactive, strongly oxidizing species capable of causing a wide range of biological damage. Freestanding Facility A diagnosing or treatment facility which is not owned by a hospital and owns/maintains it's own patient records. Fulguration Destroying tissue using an electric current. G Gene: the unit of heredity. A gene contains hereditary information encoded in the form of DNA and is located at a specific position on a chromosome in a cell's nucleus. Genes determine many aspects of anatomy and physiology by controlling the production of proteins. Each individual has a unique sequence of genes, or genetic code. Glucose (Blood Sugar): a form of sugar that is the body's primary fuel; glucose broken down from food can be converted into energy or stored. Abnormally low or high levels of glucose in the blood often indicate metabolic disturbances (e.g., diabetes). Glycerol: the central structural component of triglycerides and phospholipids. Gamma Globulin Component of blood serum (plasma) containing antibodies (sometimes abbreviated as IgG). Gamma Ray A highly energized, deeply penetrating photon that radiates from the nucleus during fission and frequently accompanies radioactive decay. Ganglion (pl. ganglia) A mass of nerve tissue containing nerve cells external to the brain or spinal cord. Gastrectomy A surgical procedure where all or a portion of the stomach is removed. Gastropylorectomy Excision of the pylorus. Gastrostomy The operation of making a permanent opening into the stomach, for the introduction of food. Gene A hereditary unit that is composed of a sequence of DNA and occupies a specific position or locus. George Nicolas Papanicolaou George Nicolas Papanicolaou was a Greek physician, anatomist, and cytologist in the United States. Glossitis Inflammation of the tongue. Glucagon A protein hormone that is produced especially by the islets of Langerhans and that promotes an increase in the sugar content of the blood by increasing the rate of glycogen breakdown in the liver. Glucose An optically active sugar C6H12O6 that has an aldehydic carbonyl group; especially : the sweet colorless soluble dextrorotatory form that occurs widely in nature and is the usual form in which carbohydrate is assimilated by animals. Glycoprotein A molecule that consists of a carbohydrate plus a protein. Glycoproteins play essential roles in the body. For instance, in the immune system almost all of the key molecules involved in the immune response are glycoproteins. Goblet Cell A mucus‐secreting epithelial cell (as of intestinal columnar epithelium) that is distended at the free end. Goiter Goiter is an enlargement of the thyroid gland. The resulting bulge on the neck may become extremely large, but most simple goiters are brought under control before this happens. Occasionally a simple goiter may cause some difficulty in breathing and swallowing. Golgi Apparatus A cytoplasmic organelle that consists of a stack of smooth membranous saccules and associated vesicles and that is active in the modification and transport of proteins. Gonagotropin (adj. Gonadotropic) A hormone secreted by the pituitary gland that stimulates gonads. Granule A small quantity of a solid substance, smaller than a grain. Grave's Disease Also known as myasthenia gravis, Grave's disease is a defect in the immune system which causes production of immunoglobulins (antibodies) which stimulate and attack the thyroid gland, causing hyperthyroidism (abnormal growth of the thyroid gland) and overproduction of thyroid hormone. Similar antibodies also attack the tissues in the eye muscles (causing exophthalmus). Growth Factor A substance that promotes the growth of cells. Growth factors include epidermal growth factor (EGF), fibroblast growth factor (FGF), erythropoietin (EPO), hematopoietic cell growth factor (HCGF), platelet‐
derived growth factor (PDGF), stem cell factors, and neurotrophins. Growth factor is produced by normal cells during embryonic development, tisue growth, and wound healing. Tumors, however, produce large amounts of growth factors. H HAART: highly active antiretroviral therapy, a term for potent combination anti‐HIV treatment that usually includes a protease inhibitor. Hematological: see hematology. Hematology: the study of blood and blood‐forming tissues. Hemoglobin (Hb): the red, iron‐based pigment in red blood cells that enables them to transport oxygen. Normal hemoglobin values are 12‐15 grams per deciliter (100 milliliters) for women and 14‐16 g/dL for men. Hepatitis A (HAV, Infectious Hepatitis): an inflammatory viral disease of the liver with a short incubation period. HAV may be transmitted by eating contaminated food, by fecal‐oral contact, and/or through household contact. Hepatitis A may be mild to severe; symptoms include fever, nausea, and jaundice. Two‐dose and three‐dose anti‐HAV vaccines are available. Hepatitis B (HBV, Serum Hepatitis): a viral liver disease that may be acute or chronic, and can be life‐
threatening. Symptoms include fever, malaise, fatigue, jaundice, abdominal tenderness, and elevated liver enzymes. Some individuals are chronic asymptomatic carriers; chronic hepatitis B may result in liver cirrhosis and/or cancer. HBV can be transmitted by sexual contact, shared needles, or contaminated blood products. Interferon alpha is used as a treatment; two three‐dose anti‐HBV vaccines are available. Hepatitis C (HCV): a contagious viral disease that causes inflammation of the liver. A chronic carrier state occurs in some individuals and may result in life‐threatening liver damage, cirrhosis, and/or liver cancer. HCV is spread mainly via contaminated blood products or shared needles. There is no standard treatment or vaccine. Herniation: Abnormal protrusion of tissue through an opening. For example, a intervertebral disk (one situated between the vertebral bodies) can protrude and impinge on a nerve root. Herpesvirus: a group of viruses that includes herpes simplex virus type 1 (HSV‐1) and 2 (HSV‐2), varicella‐zoster virus (VZV), Epstein‐Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus types 6 and 7 (HHV‐6, HHV‐7), and Kaposi's sarcoma‐associated herpesvirus (KSHV). Herpesviruses may act as opportunistic pathogens and/or cofactors in HIV pathogenesis. Horizontal Transmission: contagion or spread of an infectious disease from one individual to another within a population. Contrast with vertical transmission. Hormone: a chemical messenger (e.g., adrenaline, testosterone) involved in the regulation and coordination of cellular and bodily functions. Hormones may act locally or be secreted into the bloodstream. Hyperthyroidism: excessive functionality of the thyroid gland marked by increased metabolic rate, enlargement of the thyroid gland, rapid heart rate, high blood pressure, and various secondary symptoms. Hallucinations: Perceptions of something (such as a visual image or a sound) that does not really exist. Hallucinations usually arise from a disorder of the nervous system or in response to drugs (such as LSD). Hallucinogens: A diverse group of drugs that alter perceptions, thoughts, and feelings. Hallucinogenic drugs include LSD, mescaline, MDMA (ecstasy), PCP, and psilocybin (magic mushrooms). Halothane: Medical anesthetic gas. Hepatitis: Inflammation of the liver. Heroin: The potent, widely abused opiate that produces addiction. It consists of two morphine molecules linked together chemically. Hexane: A hydrocarbon volatile liquid found in glue or gasoline. Hippocampus: An area of the brain crucial for learning and memory. HIV (Human Immunodeficiency Virus): The virus that causes AIDS (Acquired Immunodeficiency Syndrome). Hormone: A chemical substance formed in glands in the body and carried in the blood to organs and tissues, where it influences function, structure, and behavior. Hypothalamus: The part of the brain that controls many bodily functions, including feeding, drinking, and the release of many hormones. HEENT A standard abbreviation for Head, Eyes, Ears, Nose, and Throat. Hematocrit Hematocrit is the percentage of the volume of a blood sample occupied by cells, as determined by a centrifuge or device which separates the cells and other particulate elements of the blood from the plasma. The remaining fraction of the blood sample is called plasmocrit (blood plasma volume). Hematologic Of or relating to blood or to hematology. Hemigastrectomy Return to Top | Close Window Hemorrhage A copious discharge of blood from the blood vessels. Hematogenous Originating in the blood or spread through the bloodstream. Hemotopoiesis (Adj. Hematopoietic) The formation of blood or of blood cells in the living body. Heparin A drug given directly into a vein that thins the blood when there is a danger of clotting (an anticoagulant) Hepatic flexure The hepatic flexure is situated between the ascending and the transverse part of the colon, beneath the liver. Hepatocyte An epithelial cell of the liver responsible for the synthesis, degradation, and storage of a variety of materials. Hernia The bulging of an internal organ through a weak area or tear in the muscle or other tissue that holds it in place. Most hernias occur in the abdomen. Hiatal Hernia A type of hernia that occurs when a portion of the stomach protrudes through the diaphragm (where the oesophagus normally passes through). Hilum A notch in or opening from a bodily part suggesting the hilum of a bean. Histamine Histamine is a chemical present in cells throughout the body that is released during an allergic reaction. Histamine is one of the substances responsible for the symptoms on inflammation and is the major reason for running of the nose, sneezing, and itching in allergic rhinitis. It also stimulates production of acid by the stomach and narrows the bronchi or airways in the lungs. Hodgkin's Disease Hodgkin's disease, or Hodgkin's lymphoma, is a cancer of the lymphatic system. There are two main types of lymphoma: Hodgkin's and non‐Hodgkin's. The presence of Reed‐Sternberg cells is diagnostic of Hodgkin's lymphoma and distinctly separates the Hodgkin's lymphomas from the non‐Hodgkin's lymphomas. Hypodermis The layers beneath the epidermis, comprising thick‐walled sclerenchymatous cells. Hodgkin Lymphoma and Non‐Hodgkin Lymphoma Lymphoma is a cancer of the lymphatic system ‐ the network of lymph glands and channels which occurs throughout the body. There are thirty‐ five different types of lymphoma recognised in the most recent classification system. These are grouped into two main types called Hodgkin's disease (five sub‐types), and non‐Hodgkin's lymphoma (thirty sub‐types). Hodgkin's disease (HD) is distinguished from all other types of lymphoma by the presence of a distinctive abnormal lymphocyte called a Reed‐Sternberg cell. All types of lymphoma except Hodgkin's disease are collectively known as non‐Hodgkin's lymphoma (NHL). The Editorial Committee of the International Classification of Diseases for Oncology, Third Edition, adopted the European eponymic standard, which is to drop the apostrophe 's' on eponyms (such as Hodgkin's ). Therefore, the medical community is learning to refer to Hodgkin's disease as Hodgkin disease (and Hodgkin lymphoma) and Non‐Hodgkin's lymphoma as Non‐Hodgkin lymphoma. Hofmeister‐Finsterer Operation Partial gastrectomy with closure of a portion of the lesser curvature and retrocolic anastomosis of the remainder to the jejunum. Hormonal therapy Treatment of cancer by alteration of the hormonal balance. Some cancer will only grow in the presence of certain hormones. HSM A standard medical abbreviation for Hepato Spleno Megaly (hepatosplenomegaly) ‐‐ HSM = enlarged liver (hepato) and enlarged spleen (spleno). Hyaline Transparent or nearly so and usually homogeneous. Hydatidiform Mole In human pregnancy, abnormal growth of the chorion, the outermost vascular membrane that in a normal pregnancy would enclose the embryo and ultimately give rise to the placenta. In the situation in which the hydatidiform mole develops, the embryo is usually either absent or dead. Hypochromic Anemia Anemia characterized by a decrease in the concentration of corpuscular hemoglobin. I Immunocompromised: a reduction in immune system function that results in increased susceptibility to viral, fungal, or bacterial infection. Immunosuppression: reduced function of the immune system; a state in which the immune system defenses have been suppressed, damaged, or weakened. Inflammation: A basic way in which the body reacts to infection , irritation or other injury, the key feature being redness, warmth, swelling and pain . Inflammation is now recognized as a type of nonspecific immune response . Insulin: a peptide hormone that enables the body to metabolize and use glucose. Lack of or insensitivity to insulin results in diabetes. Interferon: one of a family of cytokines (messenger proteins) that play a role in immune response. Interferons are secreted by infected cells and help protect other cells from infection. The three major classes are alpha, beta, and gamma interferon. Exogenous interferons (produced outside the body) are under study as an immunomodulatory therapy for HIV disease. Side effects of administered interferon include flu‐like symptoms (e.g., fever, aches) and anorexia. Low‐dose oral interferon alpha (Kemron) has not been shown to be effective against HIV disease in clinical trials. Interleukin (IL): a cytokine (chemical messenger) secreted by immune system blood cells that regulates a range of immune functions. Types include IL‐1, IL‐2 (T cell growth factor), IL‐10, and IL‐12. Intracellular: within a cell. Intravenous (IV): injected directly into a vein. Ingestion: The act of taking in food or other material into the body through the mouth. Inhalant: Any drug administered by breathing in its vapors. Inhalants commonly are organic solvents, such as glue and paint thinner, or anesthetic gases, such as ether and nitrous oxide. Inhalation: The act of administering a drug or combination of drugs by nasal or oral respiration. Also, the act of drawing air or other substances into the lungs. Nicotine in tobacco smoke enters the body by inhalation. Injection: A method of administering a substance such as a drug into the skin, subcutaneous tissue, muscle, blood vessels, or body cavities, usually by means of a needle. ICD‐9‐CM ICD‐9‐CM ‐ International Classification of Diseases, Ninth Revision, Clinical Modification. ICD‐9‐CM is a clinically modified statistical classification system that arranges diseases and injuries into groups according to established criteria. It is based on the ICD‐9, which was designed for the classification of morbidity and mortality information for statistical purposes, and published by the World Health Organization (WHO). ICD‐O ICD‐O ‐ International Classification of Diseases for Oncology. Most registries are currently using the Third Edition of the ICD‐O (ICD‐O‐3). Idiopathic Refers to a disease or condition of unknown cause or origin. Islets of Langerhans Also called ISLANDS OF LANGERHANS, irregularly shaped patches of endocrine tissue located within the pancreas of most vertebrates. They are named for the German physician Paul Langerhans, who first described them in 1869. The normal human pancreas contains about 1,000,000 islets. Immune System A complex system of cellular and molecular components having the primary function of distinguishing self from not self and defense against foreign organisms or substances. The primary cellular components are lymphocytes and macrophages, and the primary molecular components are antibodies and lymphokines; granulocytes and complement system are also involved in immune responses, although they are not always considered as part of the immune system per se. Immunoglobulin An antibody or, more generally, antibodies which provide protection against infectious agents. Immunoglobulins are produced by lymphocytes of the B cell type in response to the stimulation of infectious agents or the contents of vaccines. Immunoglobulins are soluble proteins present in blood serum and other body fluids. Temporary protection via immunoglobulins can be transferred to another person through injection of a purified portion of a donor's serum. Immunosuppression The artificial suppression of the immune response, usually through drugs, so that the body will not reject a transplanted organ or tissue. Drugs commonly used to suppress the immune system after transplant include prednisone, azathioprine (Imuran), cyclosporin, OKT3 and ALG. Immunotherapy Treatment of disease by stimulating the body's own immune system. This is a type of therapy currently being researched as a treatment for cancer. Incidence The rate at which a certain event occurs (e.g., the number of new cases of specific disease occurring during a certain period of time). Incisional Biopsy An incisional biopsy is different from an excisional biopsy because the surgeon does not attempt to remove the entire mass. An incisional biopsy is performed to abtain a fragment of tissue to send to the pathologist for diagnosis. Infrared Denoting thermal radiation of wavelength greater than that of the red end of the spectrum (the recorded band of wavelengths of electromagnetic vibrations of variable light). Infundibulum Any of various funnel‐shaped organs or parts. Insulin A hormone that helps the body use glucose (sugar) for energy. Intraepithelial Within the layer of cells that forms the surface or lining of an organ. Ionizing radiation Corpuscular (e.g., neutrons, electrons) or electromagnetic (e.g., gamma) radiation of sufficient energy to ionise the irradiated material. Ipsilateral Situated or appearing on or affecting the same side of the body. Isotope A form of a chemical element which varies from other forms of this element by the number of neutrons in it's nucleus. An isotope can be stable or radioactive depending upon the composition of its nucleus. J Jaundice: a yellowish discoloration of the skin and whites of the eyes due to high bilirubin levels resulting from the breakdown of red blood cells. Jaundice is associated with liver damage or disease (e.g., hepatitis), gallbladder disease, and excessive destruction of red blood cells. See also bilirubin. K Kaposi's Sarcoma (KS): an abnormal or cancerous proliferation of cells of the blood and/or lymph vessels causing tumors on the skin, mucous membranes, and/or internal organs. KS typically appears as purplish or brownish lesions and is associated with a herpesvirus (KSHV, or HHV‐8). It occurs more commonly among HIV positive gay and bisexual men than among others with HIV disease. KSHV is believed to be transmitted sexually and through deep ("French") kissing. Kidney Your kidneys are organs that filter your blood to make urine. You have two kidneys, on either side of your body. They are underneath your ribcage, near your back. Knee: The knee is a joint which has three parts. The thigh bone (the femur) meets the large shin bone (the tibia) to form the main knee joint. This joint has an inner (medial) and an outer (lateral) compartment. The kneecap (the patella) joins the femur to form a third joint, called the patellofemoral joint. The patella protects the front of the knee joint. Kahler Disease A fatal condition with occurrence of multiple malign tumours disease (multiple myeloma) in the bone marrow, causing disturbances of its function. AKA: Kahler‐Bozzolo disease, Bence Jones syndrome, Huppert disease, MacIntyre syndrome, Rustitskii disease, von Rustitskii syndrome. Kaposi sarcoma A malignant neoplastic vascular proliferation characterized by soft purplish nodules that usually occur first on the toes or feet and then slowly spread over the skin, increasing in size and number. Keratinocytes Keratinocytes are the primary cell types found in the epidermis, the outer layer of skin. Klinefelter Syndrome Syndrome in males that is characterized by small testes and long legs and enlarged breasts and reduced sperm production and mental retardation; a genetic defect in which an extra X chromosome (XXY) is present in the male. L Lactic Acidosis: a buildup of lactic acid (a by‐product of carbohydrate metabolism) in body tissues. Lesion: any abnormal tissue change caused by disease or injury. Lipid: a fat. Lipoatrophy: the depletion of subcutaneous fat stores, especially in the limbs and cheeks. Lipodystrophy: a loss of fatty tissue, usually in the limbs and face. In HIV, the term is commonly used to refer to any type of body fat redistribution, including accumulations of visceral, abdominal, and breast adipose tissue. Lipodystrophy may also refer to abnormal blood lipid and/or glucose metabolism. Lumbar: Referring to the 5 lumbar vertebrae which are situated below the thoracic vertebrae and above the sacral vertebrae in the spinal column. The 5 lumbar vertebrae are represented by the symbols L1 through L5. There are correspondingly 5 lumbar nerves. Lymphocyte: a type of white blood cell (e.g., T cell, B cell, natural killer cell) that plays a part in immune defense. Lymphocyte Proliferation Assay (LPA): a test used to measure the memory of CD4 cells (so‐called memory T cells) to antigens or microbes, such as HIV. Limbic system: A set of brain structures that generates our feelings, emotions, and motivations. It is also important in learning and memory. LSD (lysergic acid diethylamide): An hallucinogenic drug that acts on the serotonin receptor. LAD A standard medical abbreviation for LymphADenopathy (lymphadenopathy) ‐‐ LAD = enlarged or swollen lymph nodes. Lamina Propria A highly vascular layer of connective tissue under the basement membrane lining a layer of epithelium. Leiomyosarcoma A rare malignant tumor consisting of smooth muscle cells and small cell sarcoma tumor. Lesion An abnormal change in structure of an organ or part due to injury or disease; especially: one that is circumscribed and well‐defined. Leukemia Malignant proliferation of hematopoietic cells, characterized by replacement of bone marrow by neoplastic cells. The leukemic cells usually are present in peripheral blood, and may infiltrate other organs of the reticuloendothelial system, such as liver, spleen and lymph nodes. Leukemia is broadly classified into acute and chronic leukemia, with multiple distinct clinicopathologic entities subclassified in each category. LFTs A standard medical abbreviation for Liver Function Tests. Ligament A band of fibrous tissue that connects bones or cartilages, serving to support and strengthen joints. Linitis Plastica The name "Linitis plastica" is derived from a Latin word meaning "hard", which refers to gastric cancers with symptoms of the entire stomach swelling up as for an inflammation. Liposarcoma The soft tissue sarcomas are a group of cancers which develop from a number of different supportive tissues in the body including fibrous tissue, muscle, ligaments, tendons and fat. LN A standard medical abbreviation for Lymph Node or Lymph Nodes. Lumen The cavity or channel within a tube or tubular organ. Lye A strong caustic alkaline solution of potassium salts, obtained by leaching wood ashes. It is much used in making soap, etc. Lymphadenopathy Abnormally enlarged lymph nodes. Commonly called "swollen glands." Return to Top | Close Window Lymphangiogram X‐rays of the lymphatic system. A dye is injected to outline the lymphatic vessels and organs. Lymphedema Lymphedema is an accumulation of lymphatic fluid in the interstitial tissue that causes swelling, most often in the arm(s) and/or leg(s), and occasionally in other parts of the body. Lymphedema can develop when lymphatic vessels are missing or impaired (primary), or when lymph vessels are damaged or lymph nodes removed (secondary). Lymphocyte Any of the colorless weakly motile cells originating from stem cells and differentiating in lymphoid tissue (as of the thymus or bone marrow) that are the typical cellular elements of lymph , include the cellular mediators of immunity, and constitute 20 to 30 percent of the white blood cells of normal human blood. Lymphocytopenia An abnormally small number of lymphocytes in the circulating blood. Lymphoid Cells derived from stem cells of the lymphoid lineage: large and small lymphocytes, plasma cells. Lysosome A saclike cellular organelle that contains various hydrolytic enzymes. M Maintenance Therapy (Secondary Prophylaxis): preventive or suppressive therapy that follows successful initial treatment of an illness. Maintenance therapy generally continues for the lifetime of the individual to prevent disease recurrence. Malaise: a generalized feeling of illness and discomfort; a "flu‐like" feeling. Mean: a statistical measurement of the central tendency, or average, of a set of values. Contrast with median. Median: the number within a series that is preceded and followed by an equal number of values. Also, the middle value in a distribution, on either side of which lie an equal number of values. Contrast with mean. Memory T Cell: a T cell that is specialized to respond to a specific pathogen and remains in the body after an initial immune response. Memory T cells respond to a subsequent attack by the same invader in the future. Menopause: the cessation of menstruation. Natural menopause typically occurs between 45 and 60 years of age; women with HIV may experience early menopause. Metabolite: a product of metabolism, including intermediate and waste products. Methadone: an oral opioid drug used for pain therapy and to treat opiate (e.g., heroin) addiction. Methadone maintenance therapy is used to prevent withdrawal symptoms by administering a small dose of methadone on a regular (e.g., daily) basis. Miscarriage A miscarriage is when something happens before the 28th week of pregnancy that means the fetus does not survive. Molecule: a small unit of matter made up of atoms. A molecule is the smallest unit of a substance that retains its unique characteristics. Monotherapy: use of a single drug or other therapy. Multivariate Analysis: a statistical analysis technique in which multiple variables are analyzed separately to determine the contribution made by each variable to an observed result. Muscle: Muscle is the tissue of the body which primarily functions as a source of power. There are three types of muscle in the body. Muscle which is responsible for moving extremities and external areas of the body is called "skeletal muscle." Heart muscle is called "cardiac muscle." Muscle that is in the walls of arteries and bowel is called "smooth muscle." Marijuana: A drug, usually smoked but can be eaten, that is made from the leaves of the cannabis plant. The main psychoactive ingredient is THC. Medication: A drug that is used to treat an illness or disease according to established medical guidelines. Metabolism: The processes by which the body breaks things down or alters them so they can be eliminated. Methamphetamine: A commonly abused, potent stimulant drug that is part of a larger family of amphetamines. Methylphenidate (Ritalin®): Methylphenidate is a central nervous system stimulant. It has effects similar to, but more potent than, caffeine and less potent than amphetamines. It has a notably calming and "focusing" effect on those with ADHD, particularly children. Musculoskeletal system: The muscles, bones, tendons, and ligaments. Myelin: Fatty material that surrounds and insulates axons of most neurons. Macrophage A phagocytic tissue cell of the reticuloendothelial system that may be fixed or freely motile, is derived from a monocyte, and functions in the protection of the body against infection and noxious substances ‐‐ called also histiocyte. Malaise A vague feeling of bodily discomfort. Mammography Mammography is a procedure that involves taking x‐rays of the breasts to detect breast cysts or tumors, especially those that cannot be felt (palpable) by the fingers during a physical examination. A mammogram is the photographic result. The procedure does not prevent breast cancer; it is used to detect cancer early when it is more likely to be successfully treated. Margin Edge of the tissue removed during surgery. A negative surgical margin is usually a sign that no cancer was left behind near the area it was removed from. A positive surgical margin indicates that cancer cells are found at the outer edge of the tissue removed and is usually a sign that some cancer remains in the body. Mast cell Cells that play an important role in the body's allergic response. Mast cells are present in most body tissues, but are particularly numerous in connective tissue, such as the dermis (innermost layer) of skin. In an allergic response, an allergen stimulates the release of antibodies, which attach themselves to mast cells. Following subsequent allergen exposure, the mast cells release substances such as histamine (a chemical responsible for allergic symptoms) into the tissue. Master Patient Index File An alphabetized list (either card file or computerized list) maintained for all patients that have been entered into the database Matrix Ground substance in which things are embedded or that fills a space (as for example the space within the mitochondrion). most common usage is for a loose meshwork within which cells are embedded (e.g. Extracellular matrix), although it may also be used of filters or absorbent material. Mediastinum The space in the chest between the pleural sacs of the lungs that contains all the viscera of the chest except the lungs and pleurae; also : this space with its contents. Megakaryocyte Very large bone marrow cells which release mature blood platelets. Melanocytes Cells in the epidermis that produce melanin, the pigment found in the skin and eyes. Melanoma The most serious, life‐threatening form of skin cancer. Melatonin A hormone produced by the pineal gland that boosts the immune system and helps people with jet lag or insomnia. Return to Top | Close Window Meningioma Common benign brain tumours that arise from the pia‐arachnoid cells of the meninges. Meningiomas tend to occur along the superior sagittal sinus, along the sphenoid ridge or in the vicinity of the optic chiasm. Mesentery The membranes, or one of the membranes (consisting of a fold of the peritoneum and inclosed tissues), which connect the intestines and their appendages with the dorsal wall of the abdominal cavity. The mesentery proper is connected with the jejunum and ilium, the other mesenteries being called mesoccum, mesocolon, mesorectum, etc. Mesothelioma Mesothelioma is a rare form of cancer that invades mesothelial cells, which are specialized cells that make up the membranes lining the chest and abdominal cavity. Mesothelium, or the tissue formed by mesothelial cells, helps protect the organs by producing a lubricating fluid that allows the organs to move without irritating nerves. Metabolism Metabolism is the uptake and digestion of food, and the disposal of waste products. Mitochondrion Any of various round or long cellular organelles of most eukaryotes that are found outside the nucleus, produce energy for the cell through cellular respiration, and are rich in fats, proteins, and enzymes. Mitosis Mitosis is a complex process which allows the cell to give identical copies of its DNA to each of the daughter cells. Molecule The smallest unit of matter of a substance that retains all the physical and chemical properties of that substance, consisting of a single atom or a group of atoms bonded together; e.g., Ne, H2, H2O. Morbidity A diseased condition or state, the incidence of a disease or of all diseases in a population. Motor Any of various power units that develop energy or impart motion. MRI A standard abbreviation for M agnetic R esonance I maging. Mucosa (pl. mucosae) A moist tissue layer that lines hollow organs (stomach, etc.) and body cavities. Muscularis Propria The muscular wall typically made up of two layers of smooth muscle, an inner circular layer and an outer longitudinal layer. Mycosis Any disease caused by a fungus. Mycosis Fungoides A type of non‐Hodgkin's lymphoma that first appears on the skin. Also called cutaneous T‐cell lymphoma. Myelin A soft, white, and somewhat fatty material that forms a thick myelin sheath about the protoplasmic core of a myelinated nerve fiber. Return to Top | Close Window Myeloid A collective term for the non‐lymphocyte groups of white blood cells. It includes cells from the granulocyte, monocyte, and platelet lineages. Myelodysplasia Myelodysplasia is a diagnosis that includes several subcategories with very different findings and different prognoses. Myometrium Uterine smooth muscle. N Nerve: A bundle of fibers that uses chemical and electrical signals to transmit sensory and motor information from one body part to another. Neutropenia: an abnormally low number of neutrophils in the circulating blood, leading to susceptibility to infection. Neutrophil: the most common type of immune system white blood cell. Neutrophils are phagocytes that engulf and destroy bacteria and fungi. The normal count for neutrophils ranges between 3,000 and 7,000; counts below 500 indicate an increased risk of bacterial infection. Non‐Nucleoside Reverse Transcriptase Inhibitor (NNRTI): a drug (e.g., nevirapine, delavirdine, efavirenz) that binds with and inhibits the action of the HIV reverse transcriptase enzyme, thus blocking viral transcription and replication. Nucleoside Reverse Transcriptase Inhibitor (NRTI, also known as Nucleoside Analog): a compound (e.g., AZT, ddI, 3TC) that suppresses HIV replication by interfering with the reverse transcriptase enzyme. Neuron (nerve cell): A unique type of cell found in the brain and body that is specialized to process and transmit information. Neurotransmission: The process that occurs when a neuron releases neurotransmitters to communicate with another neuron across the synapse. Neurotransmitter: A chemical produced by neurons to carry messages to other neurons. Nicotine: The addictive drug in tobacco. Nicotine activates a specific type of acetylcholine receptor. Nitrites: A special class of inhalants that act primarily to dilate blood vessels and relax the muscles. Whereas other inhalants are used to alter mood, nitrites are used primarily as sexual enhancers. (See also amyl nitrite and butyl nitrite). Nitrous oxide: Medical anesthetic gas, especially used in dentistry. Also called "laughing gas." Found in whipped cream dispensers and gas cylinders. Noradrenaline: A chemical neurotransmitter that is made in the brain and can affect the heart. Nucleus: A cluster or group of nerve cells that is dedicated to performing its own special function(s). Nuclei are found in all parts of the brain but are called cortical fields in the cerebral cortex. Nucleus accumbens: A part of the brain reward system, located in the limbic system, that processes information related to motivation and reward. Virtually all drugs of abuse act on the nucleus accumbens to reinforce drug taking. Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various stomach infections. Necrosis The sum of the morphological changes indicative of cell death and caused by the progressive degradative action of enzymes, it may affect groups of cells or part of a structure or an organ. Needle Biopsy Needle biopsy is a procedure using a needle to take a sample of tissue or fluid. The procedure is also called fine needle aspiration. Neoplasia New and abnormal growth of tissue (neoplasm), which may be benign or cancerous, that serves no purpose. Neoplasm Also called tumor. Any new and abnormal growth; specifically a new growth of tissue in which the growth is uncontrolled and progressive. Malignant neoplasms are distinguished from benign in that the former show a greater degree of anaplasia and have the properties of invasion and metastasis. Nephron The nephron is the functional unit of the kidney that is responsible for the actual purification and filtration of the blood. About one million nephrons are in the cortex of each kidney, and each one consists of a renal corpuscle and a renal tubule which carry out the functions of the nephron. Neurilemma The plasma membrane surrounding a Schwann cell of a myelinated nerve fiber and separating layers of myelin. Neuroblastoma A childhood tumor that arises in the adrenal gland or in tissue in the nervous system that is related to the adrenal gland. Neuroendocrine Descriptive of cells that release a hormone into the circulating blood in response to a neural stimulus. Such cells may comprise a peripheral endocrine gland (e.g., the insulin‐secreting beta cells of the islets of Langerhans in the pancreas and the adrenaline‐secreting chromaffin cells of the adrenal medulla); others are neurons in the brain (e.g., the neurons of the supraoptic nucleus that release antidiuretic hormone from their axon terminals in the posterior lobe of the hypophysis). Neurofibromatosis A disorder inherited as an autosomal dominant and characterized especially by brown spots on the skin, neurofibromas of peripheral nerves, and deformities of subcutaneous tissue and bone. Neuroglia Supporting tissue intermingled with the essential elements of nervous tissue especially in the brain, spinal cord, and ganglia. Neuron A grayish or reddish granular cell with specialized processes that is the fundamental functional unit of the nervous tissue. Neutron A neutron is a subatomic particle found in the nucleus of every atom except that of simple hydrogen. The particle derives its name from the fact that it has no electrical charge; it is neutral. NK (Natural Killer) Cells Natural killer cells are large lymphocytes. They are the first line of defense against viruses and other invaders because they do not need to wait for an antibody response to identify foreign cells and invaders. Notochord An axial mesodermal tissue found in embryonic stages of all chordates and protochordates, often regressing as maturity is approached. Typically a rod shaped mass of vacuolated cells. It lies immediately below the nerve cord and may provide mechanical strength to the embryo. Nuclear Medicine Nuclear medicine is a medical specialty that uses very small amounts of radioactive materials or radiopharmaceuticals to diagnose and and treat disease. It is safe, painless, and cost‐effective. O Opiate (Opioid): a class of drugs (e.g., heroin, codeine, methadone) that are derived from the opium poppy plant, contain opium, or are produced synthetically and have opium‐like effects. Opioid drugs relieve pain, dull the senses, and induce sleep. Opportunistic Infection (OI): a disease caused by a microorganism that does not normally cause illness in a person with a healthy immune system, but that may cause serious disease when the immune system is weakened. Common OIs in HIV positive people include Pneumocystis carinii pneumonia (PCP), Mycobacterium avium complex (MAC), and cytomegalovirus (CMV) infection. Osteocalcin (Bone Gla Protein, BGP): the major noncollagenous protein of the bone matrix. It is synthesized by osteoblasts. During bone formation, osteocalcin is partly incorporated into the bone matrix and partly released into the circulation. Circulation of osteocalcin has proved to be a specific marker of bone formation. Osteopenia: a reduction in bone volume to subnormal levels. Osteoporosis: atrophy of the bone tissue; a loss of calcium from the bones. Osteoporosis is influenced by hormonal levels and may be ameliorated by adequate calcium intake. Occipital lobe: The lobe of the cerebral cortex at the back of the head that includes the visual cortex. Omentum A free fold of the peritoneum, or one serving to connect viscera, support blood vessels, etc. The great, or gastrocolic, omentum forms, in most mammals, a great sac, which is attached to the stomach and transverse colon, is loaded with fat, and covers more or less of the intestines. The lesser, or gastrohepatic, omentum connects the stomach and liver and contains the hepatic vessels. The gastrosplenic omentum, or ligament, connects the stomach and spleen. Oncologist A physician who specializes in the treatment of various types of cancer. Osmosis Movement of a solvent through a semipermeable membrane (as of a living cell) into a solution of higher solute concentration that tends to equalize the concentrations of solute on the two sides of the membrane. Osmotic Pertaining to or of the nature of osmosis. P Pain: An unpleasant sensation that can range from mild, localized discomfort to agony. Pain has both physical and emotional components. The physical part of pain results from nerve stimulation. Pain may be contained to a discrete area, as in an injury, or it can be more diffuse, as in disorders like fibromyalgia . Pain is mediated by specific nerve fibers that carry the pain impulses to the brain where their conscious appreciation may be modified by many factors. Palliative: offering symptomatic relief and comfort care (e.g., alleviation of pain) rather than a cure. Perinatal: refers to the period around the time of birth. Pharmacokinetics: the action of drugs in the body, including the processes of absorption, metabolism, transformation, distribution to tissues, and elimination. Phospholipid: a compound (e.g., lecithin) that contains phosphoric acid, fatty acids, and nitrogen. Physical therapy: A branch of rehabilitative health that uses specially designed exercises and equipment to help patients regain or improve their physical abilities. Physical therapists work with many types of patients, from infants born with musculoskeletal birth defects, to adults suffering from sciatica or the after‐ effects of injury, to elderly post‐stroke patients. Placebo: an inert, inactive substance; a "sugar pill." Experimental therapies are compared with a placebo in many clinical trials. Pneumocystis Carinii Pneumonia (PCP): a life‐threatening opportunistic type of pneumonia believed to be caused by a protozoan. PCP is a common infection that can cause severe illness in immunocompromised people (especially those with CD4 cell counts of fewer than 200 cells/mm3); it remains a leading cause of death in people with AIDS. Symptoms include dry cough, fever, chest tightness, and shortness of breath. Pneumocystis carinii can also infect other parts of the body. First‐line treatment and primary prophylaxis is TMP‐SMX (Bactrim, Septra); other treatments and prophylaxes include dapsone, pentamidine, and atovaquone. Polymerase Chain Reaction (PCR) Assay: a highly sensitive test that can detect small amounts of DNA or RNA (genetic material) in a blood or tissue sample using an amplification technique that multiplies the existing DNA/RNA so that it can more easily be detected. PCR assays are used to determine viral loads in persons infected with HIV. Prodrug: an inactive form of a drug that exerts its effects after metabolic processes within the body convert it to a usable or active form. Prolactin: a pituitary hormone that stimulates the secretion of breast milk. Prophylaxis: therapy that helps to prevent a disease or condition before it occurs (primary prophylaxis) or recurs (secondary prophylaxis). Protease Inhibitor (PI): a drug (e.g., saquinavir, ritonavir, indinavir) that blocks the action of the HIV protease enzyme, thereby preventing viral replication. Unlike reverse transcriptase inhibitors, protease inhibitors can inhibit HIV replication in cells that are already infected. Parietal lobe: One of the four subdivisions of the cerebral cortex; it is involved in sensory processes, attention, and language. Physical dependence: An adaptive physiological state that occurs with regular drug use and results in a withdrawal syndrome when drug use is stopped; usually occurs with tolerance. Polyneuropathy: Permanent change or malfunction of nerves. Sudden sniffing death ‐ A type of death that can occur when inhaled fumes fill up the cells in the lungs with poisonous chemicals, leaving no room for the oxygen needed to breathe. This lack of oxygen can lead to suffocation, respiratory failure, and death. Polyneuropathy: A drug that distorts perception, thought, and feeling. This term is typically used to refer to drugs with actions like those of LSD. Psychoactive: Having a specific effect on the mind. Psychoactive drug: A drug that changes the way the brain works. Palliative Palliative means "relief of symptoms." Most often, palliation is the relief of pain. Pallor Unnatural lack of color in the skin (as from bruising or sickness or emotional distress) Pancytopenia An abnormal deficiency in all blood cells (red blood cells and white blood cells and platelets); usually associated with bone marrow tumor or with aplastic anemia Panniculitis Inflammation of subcutaneous fat. Papilla (pl. papillae) A hump or swelling. Parenchyma The essential elements of an organ, used in anatomical nomenclature as a general term to designate the functional elements of an organ, as distinguished from its framework or stroma. Parietal Peritoneum The peritoneum is a thin membrane that lines the abdominal and pelvic cavities, and covers most abdominal viscera. It is composed of layer of mesthelium supported by a thin layer of connective tissue. Parietal peritoneum is that portion that lines the abdominal and pelvic cavities. Pathogen A specific causative agent (such as a bacterium or virus) of disease. Patency The state of being freely open or exposed. Perichondrium A membrane around the surface of cartilage. Peritoneum The smooth serous membrane which lines the cavity of the abdomen and covers most of the abdominal organs forming a closed, or nearly closed sac. Petechiae Pin‐head‐sized sites of bleeding in the skin. This type of bleeding results from a very low platelet count. The small punctate hemorrhages are frequently seen on the legs, feet, trunk and arms. They evolve from red to brown and are eventually disappear. They stop developing when the platelet count increases. Peyer's patch These are quite large aggregates of lymphoid tissue found in the small intestine, part of the lymphatic system which help to fight infection. pH A measure of acidity and alkalinity of a solution. The measure is a number on a scale on which a value of 7 represents neutrality and lower numbers indicate increasing acidity and higher numbers increasing alkalinity. On the scale, each unit of change represents a tenfold change in acidity or alkalinity. Phagocytic Capable of functioning as a phagocyte. A phagocyte is a cell that is able to engulf and break down foreign particles, cell debris and disease producing micro‐organisms in the body. Form an important part of the natural defence mechanism in most animals. Pheochromocytoma A tumor that is derived from chromaffin cells and is usually associated with paroxysmal or sustained hypertension. Phenotype A set of observable physical characteristics of an individual organism. A single characteristic can be referred to as a "trait," although a single trait is sometimes also called a phenotype. For example, blond hair could be called a trait or a phenotype, as could obesity. A phenotype can be the result of many factors, including an individual's genotype, environment, and lifestyle, and the interactions among these factors. The observed manifestation of a genotype, a phenotype may be expressed physically, biochemically, or physiologically. Philadelphia Chromosome Characteristic chromosomal abnormality in which a portion of chromosome 22 is translocated to chromosome 9. This abnormality is found in nearly all cases of chronic myeloid leukaemia and some cases of acute lymphoblastic leukaemia. Placenta The vascular organ in mammals, except monotremes and marsupials, that unites the fetus to the maternal uterus and mediates its metabolic exchanges through a more or less intimate association of uterine mucosal with chorionic and usually allantoic tissues. Plasma The fluid part of blood, lymph, or milk as distinguished from suspended material. Plasmacytoma Any discrete, presumably solitary, mass of neoplastic plasma cells either in bone marrow or various extramedullary sites. Platelets A particle found in the bloodstream that binds at the site of a wound to begin the blood clotting process. Platelets are formed in bone marrow. Pleomorphism A hardening within the nervous system, especially of the brain and spinal cord, resulting from degeneration of nervous elements such as the myelin sheath. Pleura The delicate serous membrane that lines each half of the thorax of mammals and is folded back over the surface of the lung of the same side. Pleural Effusion A collection of fluid (or blood) in the pleural space (in one side of the chest cavity around the lung). May be secondary to trauma, cancer, nephrotic syndrome, kidney disease, pancreatitis, congestive heart failure and cirrhosis. Plicae Circulares Plicae circulares are macroscopically visible, crescent‐shaped folds of the mucosa and submucosa. Plicae circulares extend around one‐half to two‐thirds of the circumference of the lumen of the small intestine. Polypectomy Excision of a polyp. Polyvinylchloride A carcinogenic polymer used in plastics and is commonly known as PVC. Psoriasis Psoriasis is a condition characterized by severe scaling and flakiness. Recent evidence indicates that the skin is rapidly reproducing cells creating an excess build‐up because the skin cannot exfoliate normally. Primary Site The anatomic site where the original tumor is located. Primary cancer is usually named after the organ in which it starts. For example, cancer that starts in the breast is always breast cancer even if it spreads (metastasizes) to other organs such as bones or lungs. Process Any marked prominence or projecting part. Progesterone A female steroid sex hormone C21H30O2 that is secreted by the corpus luteum to prepare the endometrium for implantation and later by the placenta during pregnancy to prevent rejection of the developing embryo or fetus. Prognosis The patient's potential clinical outlook based on the status and probable course of his disease. Prolactin Prolactin,produced from the anterior pituitary gland, it's found in the serum of normal females and males. Prolactin's principal physiological action is to initiate and sustain lactation. Proliferation The reproduction or multiplication of similar forms, especially of cells and morbid cysts. Proptosis Forward displacement (bulging) of an organ, typically the eyeball(s). Protein Any of numerous naturally occurring extremely complex substances that consist of amino‐acid residues joined by peptide bonds, contain the elements carbon, hydrogen, nitrogen, oxygen, usually sulfur, and occasionally other elements (as phosphorus or iron), and include many essential biological compounds (as enzymes, hormones, or immunoglobulins). Proton A proton is a subatomic particle found in the nucleus of every atom. The particle has a positive electrical charge, equal and opposite to that of the electron. Puberty The condition of being or the period of becoming first capable of reproducing sexually marked by maturing of the genital organs, development of secondary sex characteristics, and in the human and in higher primates by the first occurrence of menstruation in the female. Puerperium The period between childbirth and the return of the uterus to its normal size. Purpura Hemorrhage under a surface that is about 1.0 cm. in diameter. Pyelogram X‐ray study of the kidney especially showing the pelvis (urine‐collecting basin) of the kidney and the ureter. R Radiculopathy is a medical term used to describe pain, numbness, tingling, and weakness in the arms or legs caused by a nerve root problem. If the nerve problem is in the neck, it is called a cervical radiculopathy. However, since sciatica affects the low back, it is called a lumbar radiculopathy. Red blood cells Red blood cells are the part of your blood that makes it red. Their main job is to carry oxygen from your heart and lungs to the tissues of your body. Once these cells unload oxygen, they pick up carbon dioxide. They take carbon dioxide back to your lungs so it can be breathed out of your body. Receptor: A large molecule that recognizes specific chemicals (normally neurotransmitters, hormones, and similar endogenous substances) and transmits the message carried by the chemical into the cell on which the receptor resides. Relapse: In drug abuse, relapse is the resumption of drug use after trying to stop taking drugs. Relapse is a common occurrence in many chronic disorders, including addiction, that require behavioral adjustments to treat effectively. Reuptake: The process by which neurotransmitters are removed from the synapse by being "pumped" through transporters back into the axon terminals that first released them. Reuptake pump (transporter): The large molecule that actually transports neurotransmitter molecules back into the axon terminals that released them. Reward: The process that reinforces behavior. It is mediated at least in part by the release of dopamine into the nucleus accumbens. Human subjects report that reward is associated with feelings of pleasure. Reward system (or brain reward system): A brain circuit that, when activated, reinforces behaviors. The circuit includes the dopamine‐containing neurons of the ventral tegmental area, the nucleus accumbens, and part of the prefrontal cortex. The activation of this circuit causes feelings of pleasure. Route of administration: The way a drug is put into the body. Drugs can enter the body by eating, drinking, inhaling, injecting, snorting, smoking, or absorbing a drug through mucous membranes. Rush: A surge of pleasure that rapidly follows administration of some drugs. Radioactive Isotope Isotope refers to one of two or more atoms of the same element that have the same number of protons in their nucleus but different numbers of neutrons. A radioactive isotope is a natural or artificially created isotope of a chemical element having an unstable nucleus that decays, emitting alpha, beta, or gamma rays until stability is reached. Radiotherapy The treatment of disease with radiation (as X rays). Refractory Not readily yielding to treatment. Reportable List A list that identifies all diagnoses and types of cases to be included in the cancer registry data base. For most registries in the world, the "reportable list" is everything listed in ICD‐O‐3 with a /2 or a /3 in the behavior code. Reportable Malignancies Tumors required to be reported. Typically, in most cancer registries, the reportable tumors are those that are listed in the International Classification of Diseases for Oncology, Third Edition which have a behavior defined as in situ (behavior code = /2) or invasive (behavior code = /3). Reproperitoneal Having to do with the area outside or behind the peritoneum (the tissue that lines the abdominal wall and covers most of the organs in the abdomen). Residual Disease The disease has not been eradicated. Reticuloendothelial system A group of cells having the ability to take up and sequester inert particles and vital dyes, including macrophages or macrophage precursors, specialized endothelial cells lining the sinusoids of the liver, spleen, and bone marrow, and reticular cells of lymphatic tissue (macrophages) and of bone marrow (fibroblasts). Retinoblastoma An ocular malignant neoplasm of the retina, usually arise in the first 2 years of life, it is the most form of intraocular malignancy in children. Rhabdomyosarcoma Rhabdomyosarcoma tumors arise from a cell called a "rhabdomyoblast", which is a primitive muscle cell. Instead of differentiating into striated muscle cells, the rhabdomyoblasts grow out of control. Since this type of muscle is located throughout the body, the tumors can appear at numerous locations. Ribosome Any of the RNA‐rich cytoplasmic granules that are sites of protein synthesis. Roentgen The international unit of x‐ or gamma‐radiation, abbreviated r or R; named after the German physicist, Wilhelm Roentgen, who discovered roentgen ray in 1895. Rubric A rubric is a chart or template which specifies the criteria to be used to evaluate an assignment. S Sciatica : Pain resulting from irritation of the sciatic nerve, typically felt from the low back to behind the thigh and radiating down below the knee. While sciatica can result from a herniated disc directly pressing on the nerve, any cause of irritation or inflammation of this nerve can reproduce the painful symptoms of sciatica. Diagnosis is by observation of symptoms, physical and nerve testing, and sometimes by X‐ray or MRI if a herniated disk is suspected. Seroconversion: the development of antibodies directed against an antigen; the change in a person's antibody status from negative to positive. Vaccine‐induced seroconversion is not an infection. Serum: the fluid, noncellular portion of blood that remains after coagulation; lymphatic fluid. Seizure A seizure (or fit) is when there is too much electrical activity in your brain, which results in muscle twitching and other symptoms. Spinal cord: The major column of nerve tissue that is connected to the brain and lies within the vertebral canal and from which the spinal nerves emerge. Thirty‐one pairs of spinal nerves originate in the spinal cord: 8 cervical , 12 thoracic , 5 lumbar, 5 sacral, and 1 coccygeal. The spinal cord and the brain constitute the central nervous system ( CNS ). The spinal cord consists of nerve fibers that transmit impulses to and from the brain. Like the brain, the spinal cord is covered by three connective‐tissue envelopes called the meninges . The space between the outer and middle envelopes is filled with cerebrospinal fluid ( CSF ), a clear colorless fluid that cushions the spinal cord against jarring shock. Also known simply as the cord. Serotonin: A neurotransmitter that regulates many functions, including mood, appetite, and sensory perception. Sex hormones: Hormones that are found in higher quantities in one sex than in the other. Male sex hormones are the androgens, which include testosterone; and the female sex hormones are the estrogens and progesterone. Stimulants: A class of drugs that elevates mood, increases feelings of well‐being, and increases energy and alertness. These drugs produce euphoria and are powerfully rewarding. Stimulants include cocaine, Methamphetamine, and methylphenidate (Ritalin). Synapse: The site where presynaptic and postsynaptic neurons communicate with each other. Synaptic space (or synaptic cleft): The intercellular space between the presynaptic and postsynaptic neurons. Serum The clear liquid that separates from the blood when it is allowed to clot. This fluid retains any antibodies that were present in the whole blood. Sarcoma A malignant neoplasm arising in tissue of mesodermal origin (as connective tissue, bone, cartilage, or striated muscle) Sclerosis A hardening within the nervous system, especially of the brain and spinal cord, resulting from degeneration of nervous elements such as the myelin sheath. Sebaceous Of, relating to, or being fatty material. Sezary Disease This is a variant of a cutaneous T‐cell lymphoma. It likely represents the leukemic phase of mycosis fungoides. Shared Follow‐up Shared follow‐up is the act or process of sharing information or contacting the patient at least once per year to ascertain vial status, cancer status, and other information. Sideroblast An erythroblast having granules of ferritin Signet Ring The early stage of trophozoite development of the malaria parasite in the red blood cell; the parasite cytoplasm stains blue around its circular margin, and the nucleus stains red in Romanowsky stains, while the central vacuole is clear, giving the ringlike appearance. Sinoatrial Node The sinoatrial (SA) node is a section of nodal tissue that is located in the upper wall of the right atrium. The SA node is also referred to as the pacemaker of the heart. Sister Mary Joseph node (Sister Joseph node) A malignant intra‐abdominal neoplasm metastatic to the umbilicus. Sphincter A ringlike band of muscle fibres that constricts a passage or closes a natural orifice, also called musculus sphincter. Splenomegaly Enlargement of the spleen. Squamous cell carcinoma A malignant neoplasm of squamous cells. In the white population, squamous cell carcinoma of the skin is associated with prolonged exposure to ultraviolet light and these neoplasms are slow to metastasis even after becoming invasive. Staging A term used to define the size and physical extent of a cancer; staging is the process of assigning a stage to a particular cancer in a specific patient in light of all the available information. Stem Cell "Master Cells" that generate other differentiated cell types. Each tissue within the body contains a unique type of stem cells that renew and replace that tissue (e.g. nerve, brain, cartilage, blood) when needed due to damage or wear and tear. Stem cells of the blood (hematopoietic stem cells) generate all other blood cells in the human body, including red blood cells, platelets, and white blood cells. Sources of hematopoietic stem cells include umbilical cord blood, bone marrow, peripheral blood and embryos. Stenosis A narrowing, as in aortic stenosis (narrowing of the aortic valve in the heart), pulmonary stenosis (narrowing of the pulmonary valve in the heart), pyloric stenosis (narrowing of the outlet of the stomach), spinal stenosis (narrowing of the vertebral canal, often with impingement upon the spinal cord).From the Greek "stenos" meaning narrow. Stereotactic Biopsy Stereotactic biopsy is a precise method of sampling a small region of brain tissue using image‐guidance and minimally invasive techniques. Through only a skin puncture and tiny bony opening, an instrument is accurately passed into a brain lesion in order to determine its nature. This approach is often used to diagnose brain tumors or other disorders. CT or MRI guidance is used. Steroid Any hormone affecting the development and growth of sex organs. Testosterone and estrogen are steroids. Synthetic steroids are useful cancer treatments, but they might have undesirable side‐effects. Stromal Cells Connective tissue cells of an organ found in the loose connective tissue. These are most often associated with the uterine mucosa and the ovary as well as the haematopoietic system and elsewhere. Subcutis Subcutis the deepest layer of skin and is also known as the subcutaneous layer. Sulcus A groove or furrow, as one of the grooves on the surface of the cerebrum in mammals. Surgicel Hemostatic agent. T Testosterone: a steroid hormone produced by the testes and adrenal glands. Testosterone is required for sperm production, the development of the male reproductive organs, and the emergence of male secondary sexual characteristics. The hormone is also required for the buildup of lean muscle mass. Thrombocytopenia: an abnormally low number of platelets; the condition may result in abnormal bleeding and bruising. The normal platelet range is 150,000‐450,000 per microliter of blood. Thrombocytopenia may be controlled by the administration of certain cytokines or by removal of the spleen. Triglyceride: a combination of glycerol and fatty acid that circulates in the blood. Temporal lobe: The lobe of the cerebral cortex at the side of the head that hears and interprets music and language. Thalamus: Located deep within the brain, the thalamus is the key relay station for sensory information flowing into the brain, filtering out important messages from the mass of signals entering the brain. THC: Delta‐9‐tetrahydrocannabinol; the main active ingredient in marijuana, which acts on the brain to produce its effects. Tobacco: A plant widely cultivated for its leaves, which are used primarily for smoking; the tabacum species is the major source of tobacco products. Tolerance: A condition in which higher doses of a drug are required to produce the same effect as during initial use; often leads to physical dependence. Toluene: A light colorless liquid solvent found in many commonly abused inhalants, including airplane glue, paint sprays, and paint and nail polish removers. Transporter: A light colorless liquid solvent found in many commonly abused inhalants, including airplane glue, paint sprays, and paint and nail polish removers. Trichloroethylene: A liquid used as a solvent and in medicine as an anesthetic and analgesic. Found in cleaning fluid and correction fluid. T‐cells T‐cells are thymus‐derived lymphocytes. T‐cells are the major component of cell‐mediated immunity. There are several types of T Cells: Cytotoxic T‐cells destroy cancer cells and foreign invaders; helper T‐
cells that work in conjunction with white blood cells; and suppressor T cells that play a role in controlling white blood cell function. Technetium A silvery‐grey metallic element, artificially produced by bombardment of molybdenum by deuterons: used to inhibit corrosion in steel. The radioisotope technetium (Tc99m), with a half‐life of six hours, is used in radiotherapy. Teratoma A benign tumor of germ cell origin, composed of nonproliferating somatic tissues. In the testis, teratomas are rare and usually found in prepubertal children. Testosterone A hormone that is produced especially by the testes or made synthetically and that is responsible for inducing and maintaining male secondary sex characters. Tetraploid Individual or cell having four times the haploid number of chromosomes in the cell nucleus. Thoracentesis Removal of fluid in the pleura through a needle. Thyroxine An iodine‐containing hormone C15H11I4NO4 that is an amino acid produced by the thyroid gland as a product of the cleavage of thyroglobulin , increases metabolic rate, and is used to treat thyroid disorders. Tinnitus Noise perceived by the brain when no external sound is present. This sensation can be heard in one or both ears; it can be a sign of an underlying disorder but can occasionally occur for no apparent reason Toluene A solvent used in manufacturing perfumes, detergents, gasoline, other chemicals, and medicines. Acute exposure can irritate the nose, throat, and eyes, and cause headaches, loss of consciousness, and death. Chronic exposure can cause mutations, damage developing fetuses, and damage the liver, kidneys, brain, and bone marrow. Trephine An instrument for removing a circular disc of bone. Triiodothyronine An iodine‐containing hormone C15H12 I 3 NO 4 that is an amino acid derived from thyroxine. Tumor Markers Tumor markers are measurable biochemicals that are associated with a malignancy. They are either produced by tumor cells (tumor‐derived) or by the body in response to tumor cells (tumor‐associated). They are typically substances that are released into the circulation and thus measured in the blood. There are a few exceptions to this, such as tissue‐bound receptors that must be measured in a biopsy from the solid tumor or proteins that are secreted into the urine. U Ulcer An ulcer is an open sore. Ulcers can happen in many parts of your body, such as in your stomach, and the skin of your legs, mouth, or genitals. Ultrasound A set of sound waves at a particular frequency which can be used to image internal organs, for example, a baby in the womb. Umbilical Cord A cord arising from the navel that connects the fetus with the placenta. V Vertical Transmission: the conveyance of a pathogen such as HIV from a mother to a fetus or newborn. Vertical transmission may occur in utero (in the womb), intrapartum (during birth), or postpartum (via breast‐feeding). Contrast with horizontal transmission. Viral Load: the amount of virus in the blood or body tissues. The presence of HIV RNA indicates that the virus is replicating. Changes in viral load may be used to gauge drug effectiveness and disease progression. Viral load is measured using tests such as polymerase chain reaction (PCR) or branched‐
chain DNA (bDNA), and is typically expressed as the number of copies of RNA per milliliter (mL) of blood plasma. Viral Rebound: an increase in viral load following a previous decrease due to anti‐HIV therapy. Viremia: the presence of virus in the blood. Ventral tegmental area (VTA): The group of dopamine‐containing neurons that make up a key part of the brain reward system. These neurons extend axons to the nucleus accumbens and the prefrontal cortex. Vertigo: The sensation of dizziness. Vesicle: A membranous sac within an axon terminal that stores and releases neurotransmitter. Vagus Nerve Either of the 10th pair of cranial nerves that arise from the medulla and supply chiefly the viscera especially with autonomic sensory and motor fibers ‐‐ called also vagus. Vascularity The blood supply of a tumour. Venous Venous refers to the system or veins by which blood is returned to the lungs for oxygenation. Vertigo Dizziness or a sensation of whirling or irregular motion that arises from problems within the vestibular portion of the inner ear. Objective vertigo is the name given the sensation that the world is spinning about the patient. Subjective vertigo indicates the patient feels he is moving in space. Villus (pl. villi) One of the minute finger‐shaped processes of the mucous membrane of the small intestine that serve in the absorption of nutriment. Virchow node (jugular gland, signal node) A firm supraclavicular lymph node, especially on the left side, sufficiently enlarged that it is palpable from the cutaneous surface; such a lymph node is so termed because it may be the first recognised presumptive evidence of a malignant neoplasm in one of the viscera. A signal node that is known to contain a metastasis from a malignant neoplasm is sometimes designated by an old eponym, Troisier ganglion. Viruses Viruses are infectious agents found in virtually all life forms, including humans, animals, plants, fungi, and bacteria. Viruses consist of genetic material‐either deoxyribonucleic acid (DNA) or ribonucleic acid (RNA)‐surrounded by a protective coating of protein, called a capsid, with or without an outer lipid envelope. Viscosity The resistance offered by a fluid (liquid or gas) to flow. The viscosity is a characteristic property and is a measure of the combined effects of adhesion and cohesion. Hyperviscosity syndrome: Blood too thick to flow properly. Vitamin Any of various organic substances that are essential in minute quantities to the nutrition of most animals and some plants, act especially as coenzymes and precursors of coenzymes in the regulation of metabolic processes but do not provide energy or serve as building units, and are present in natural foodstuffs or sometimes produced within the body. Von Recklinghausen disease Neurofibromatosis is an inherited disorder of the nervous system. W Wasting Syndrome: a condition characterized by atrophy of lean body mass and involuntary weight loss of more than 10% of normal body weight. Other symptoms may include chronic diarrhea, fatigue, weakness, and fever. Death typically occurs when body weight falls to one‐third of ideal weight, or when body cell mass decreases by 50%. Withdrawal: Symptoms that occur after chronic use of a drug is reduced or stopped. WNL: A standard abbreviation for W ithin N ormal L imits. Waldenstrom's Macroglobulinemia: Waldenstrom's macroglobulinemia is a cancer of white blood cells known as B lymphoctyes. Waldeyer ring The lymphoid ring of the nasopharynx. A ring of lymphoid tissue that encircles the nasopharynx and oropharynx. It is formed by the lymphatic tissue of the pharynx, the palatine tonsil, and the lingual tonsil, as well as other collections of lymph tissue in the area. Wilms Tumor Wilms' tumor is a solid tumor that originates in the kidney. It usually occurs in children under age 15 and is very different from adult kidney cancer. Xeroderma Pigmentosum Xeroderma Pigmentosum is a rare genetic condition characterized by an eruption of exposed skin occurring in childhood and photosensitivity with severe sunburn; inherited as a recessive autosomal trait in which DNA repair processes are defective so they are more likely to chromosome breaks and cancers when exposed to ultraviolet light.