Hepatitis C Glossary of Terms

Abdomen: The belly , that part of the body that contains all of the structures between the chest and the pelvis . The abdomen is separated anatomically from the chest by the diaphragm , the powerful muscle spanning the body cavity below the lungs .
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Abdominal: Relating to the abdomen, the belly , that part of the body that contains all of the structures between the chest and the pelvis . The abdomen is separated anatomically from the chest by the diaphragm , the powerful muscle spanning the body cavity below the lungs .
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Abdominal cavity: The cavity within the abdomen, the space between the abdominal wall and the spine.
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Abdominal pain: Pain in the belly (the abdomen). Abdominal pain can come from conditions affecting a variety of organs. The abdomen is an anatomical area that is bounded by the lower margin of the ribs above, the pelvic bone (pubic ramus) below, and the flanks on each side. Although abdominal pain can arise from the tissues of the abdominal wall that surround the abdominal cavity (the skin and abdominal wall muscles), the term abdominal pain generally is used to describe pain originating from organs within the abdominal cavity (from beneath the skin and muscles). These organs include the stomach, small intestine, colon, liver, gallbladder, and pancreas.
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Abnormal: Not normal. Deviating from the usual structure, position, condition, or behavior. In referring to a growth, abnormal may mean that it is cancerous or premalignant (likely to become cancer ).
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Acquired: Anything that is not present at birth but develops some time later. In medicine, the word "acquired" implies "new" or "added." An acquired condition is "new" in the sense that it is not genetic (inherited) and "added" in the sense that was not present at birth.
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Acute: Of abrupt onset, in reference to a disease. Acute often also connotes an illness that is of short duration, rapidly progressive, and in need of urgent care.
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Alanine: An amino acid, one of the 20 building blocks of protein. Alanine is not an "essential" amino acid. It is not essential to the diet, but can be made by the body from other substances. Alanine was discovered in protein in 1875. Symbol: Ala.

Alcohol: An organic chemical in which one or more hydroxyl (OH) groups are attached to carbon (C) atoms in place of hydrogen (H) atoms. Common alcohols include ethyl alcohol or ethanol (found in alcoholic beverages), methyl alcohol or methanol (can cause blindness) and propyl alcohol or propanol (used as a solvent and antiseptic ). Rubbing alcohol is a mixture of acetone , methyl isobutyl ketone, and ethyl alcohol. In everyday talk, alcohol usually refers to ethanol as, for example, in wine, beer, and liquor. It can cause changes in behavior and be addictive.
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Aminotransferase: An enzyme that catalyzes the transfer of an amino group from a donor molecule to a recipient molecule. The donor molecule is usually an amino acid while the recipient (acceptor) molecule is usually an alpha-2 keto acid. An aminotransferase is also called a transaminase. Two of the better known enzymes in this class are serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT). Both of these transaminases (SGOT and SGPT) are normally found primarily in cells in the liver and heart, are released into the bloodstream as the result of liver or heart damage, and so are used as liver and heart tests.

Amplification: Making multiple copies of a gene or of any sequence of DNA . Repeated copying of a piece of DNA.
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Anemia: The condition of having less than the normal number of red blood cells or less than the normal quantity of hemoglobin in the blood. The oxygen-carrying capacity of the blood is, therefore, decreased.
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Antibody: An immunoglobulin, a specialized immune protein , produced because of the introduction of an antigen into the body, and which possesses the remarkable ability to combine with the very antigen that triggered its production.
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Antigen: A substance that is capable of causing the production of an antibody .
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Antiviral: An agent that kills a virus or that suppresses its ability to replicate and, hence, inhibits its capability to multiply and reproduce.
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Antiviral agent: An agent that kills viruses or suppresses their replication and, hence, inhibits their capability to multiply and reproduce.
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Arthralgia: Pain in the joints. There are many possible causes of pain in a joint. The Greek "algos" means "pain."

Arthritis: Inflammation of a joint. When joints are inflamed they can develop stiffness, warmth, swelling, redness and pain. There are over 100 types of arthritis. (see osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, lupus, gout, pseudogout).

Ascites: Abnormal buildup of fluid in the abdomen. Ascites can occur as a result of a number of conditions, including severe liver disease and the presence of malignant cells within the abdomen.

Assay: An assay is an analysis done to determine:

1. The presence of a substance and the amount of that substance. Thus, an assay may be done for example to determine the level of thyroid hormones in the blood of a person suspected of being hypothyroid (or hyperthyroid).
2. The biological or pharmacological potency of a drug. For example, an assay may be done of a vaccine to determine its potency.

Asymptomatic: Without symptoms. For example, an asymptomatic infection is an infection with no symptoms.

Attention: The ability to focus selectively on a selected stimulus, sustaining that focus and shifting it at will. The ability to concentrate.
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Autoimmune: Pertaining to autoimmunity, a misdirected immune response that occurs when the immune system goes awry and attacks the body itself.
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Autoimmune disease: An illness that occurs when the body tissues are attacked by its own immune system . The immune system is a complex organization within the body that is designed normally to "seek and destroy" invaders of the body, including infectious agents. Patients with autoimmune diseases frequently have unusual antibodies circulating in their blood that target their own body tissues.
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Biochemical: Relating to biochemistry, the application of the tools and concepts of chemistry to living systems.
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Biopsy: The removal of a sample of tissue for purposes of diagnosis. (Many definitions of "biopsy" stipulate that the sample of tissue is removed for examination under a microscope. This may or may not be the case. The diagnosis may be achieved by other means such as by analysis of chromosomes or genes.)
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Blood: The familiar red fluid in the body that contains white and red blood cells, platelets, proteins, and other elements. The blood is transported throughout the body by the circulatory system. Blood functions in two directions: arterial and venous. Arterial blood is the means by which oxygen and nutrients are transported to tissues while venous blood is the means by which carbon dioxide and metabolic by-products are transported to the lungs and kidneys, respectively, for removal from the body.

Blood transfusion : The transfer of blood or blood components from one person (the donor) into the bloodstream of another person (the recipient). This may be done as a lifesaving maneuver to replace blood cells or blood products lost through bleeding. Transfusion of your own blood (autologous) is the safest method but requires advance planning and not all patients are eligible. Directed donor blood allows the patient to receive blood from known donors. Volunteer donor blood is usually most readily available and, when properly tested has a low incidence of adverse events. Blood conserving techniques are an important aspect of limiting transfusion requirements.
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Cancer: An abnormal growth of cells which tend to proliferate in an uncontrolled way and, in some cases, to metastasize (spread).
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Carcinoma: Cancer that begins in the skin or in tissues that line or cover body organs. For example, carcinoma can arise in the breast , colon, liver, lung, prostate, and stomach.
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CDC: The Centers for Disease Control and Prevention , the US agency charged with tracking and investigating public health trends. The stated mission of the CDC is "To promote health and quality of life by preventing and controlling disease, injury, and disability." The CDC is a part of the U.S. Public Health Services (PHS) under the Department of Health and Human Services (HHS).
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Cell: The basic structural and functional unit in people and all living things. Each cell is a small container of chemicals and water wrapped in a membrane .
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Centers for Disease Control and Prevention: The US agency charged with tracking and investigating public health trends. The stated mission of the Centers for Disease Control and Prevention, commonly called the CDC, is "To promote health and quality of life by preventing and controlling disease, injury, and disability."
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Chemotherapy : 1. In the original sense, a chemical that binds to and specifically kills microbes or tumor cells. The term chemotherapy was coined in this regard by Paul Ehrlich (1854-1915).
2. In oncology, drug therapy for cancer. Also called "chemo" for short.
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Chronic: This important term in medicine comes from the Greek chronos, time and means lasting a long time.
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Cirrhosis: An abnormal liver condition characterized by irreversible scarring of the liver. Alcohol and viral hepatitis B and C are among the many causes of cirrhosis. Cirrhosis can cause yellowing of the skin (jaundice), itching, and fatigue. Diagnosis of cirrhosis can be suggested by physical examination and blood tests, and can be confirmed by liver biopsy in some patients. Complications of cirrhosis include mental confusion, coma, fluid accumulation (ascites), internal bleeding, and kidney failure. Treatment of cirrhosis is designed to limit any further damage to the liver as well as complications. Liver transplantation is becoming an important option for patients with advanced cirrhosis.

Clinical: 1. Having to do with the examination and treatment of patients. 2. Applicable to patients. A laboratory test may be of clinical value (of use to patients).
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Clinical trial: See: Clinical trials. See also: Inconclusive clinical trial; Negative clinical trial; Non-inferior clinical trial; Positive clinical trial.

Clinical trials: Trials to evaluate the effectiveness and safety of medications or medical devices by monitoring their effects on large groups of people.
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Cocaine: The most potent stimulant of natural origin, a bitter addictive anesthetic (pain blocker) which is extracted from the leaves of the coca scrub (Erythroxylon coca) indigenous to the Andean highlands of South America.
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Code: The genetic code is the correspondence between the triplet of bases in DNA with the amino acids. The discovery of the genetic code clearly ranks as one of the premiere events of what has been called the Golden Age of Biology (and Medicine).
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Complication: In medicine, an additional problem that arises following a procedure, treatment or illness and is secondary to it. A complication complicates the situation.
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Condition: The term "condition" has a number of biomedical meanings including the following:

1. An unhealthy state, such as in "this is a progressive condition."
2. A state of fitness, such as "getting into condition."
3. Something that is essential to the occurrence of something else; essentially a "precondition."
4. As a verb: to cause a change in something so that a response that was previously associated with a certain stimulus becomes associated with another stimulus; to condition a person, as in behavioral conditioning.

Contrast: Short for "contrast media." Contrast media are X-ray dyes used to provide contrast, for example, between blood vessels and other tissue.

Cornea: The clear front window of the eye that transmits and focuses light into the eye.
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Cough: A rapid expulsion of air from the lungs typically in order to clear the lung airways of fluids, mucus, or material. Also called tussis.

Cryoglobulinemia: The presence in blood of abnormal proteins called cryoglobulins that, by definition, have the unusual properties of precipitating from the blood serum when it is chilled and redissolving upon rewarming. (Cryoglobulins are gamma globulins with a molecular weight of approximately 200,000.)
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Cut: An area of severed skin. Wash a cut or scrape it with soap and water, and keep it clean and dry. Putting alcohol, hydrogen peroxide, or iodine into a wound can delay healing, and should be avoided. Seek medical care if you think you might need stitches, as delay can increase the rate of wound infection. If the cut results from a puncture wound through the shoe, there is a high risk of infection, and you should see your healthcare professional. Redness, swelling, increased pain, and pus draining from the wound also indicate an infection that requires professional care.

Cytotoxic: Toxic to cells, cell-toxic, cell-killing. Any agent or process that kills cells. Chemotherapy and radiotherapy are forms of cytotoxic therapy. They kill cells.
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Dengue: An acute mosquito-borne viral illness of sudden onset that usually follows a benign course with headache, fever, prostration, severe joint and muscle pain, swollen glands (lymphadenopathy) and rash. The presence (the "dengue triad") of fever, rash, and headache (and other pains) is particularly characteristic of dengue. Dengue is endemic throughout the tropics and subtropics. It goes by other names including breakbone or dandy fever. Victims of dengue often have contortions due to the intense joint and muscle pain. Hence, the name "breakbone fever." Slaves in the West Indies who contracted dengue were said to have "dandy fever" because of their postures and gait.

Depression : An illness that involves the body, mood, and thoughts, that affects the way a person eats and sleeps, the way one feels about oneself, and the way one thinks about things. A depressive disorder is not the same as a passing blue mood. It is not a sign of personal weakness or a condition that can be wished away. People with a depressive disease cannot merely "pull themselves together" and get better. Without treatment, symptoms can last for weeks, months, or years. Appropriate treatment, however, can help most people with depression.
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Diabetes: Refers to diabetes mellitus or, less often, to diabetes insipidus . Diabetes mellitus and diabetes insipidus share the name "diabetes" because they are both conditions characterized by excessive urination (polyuria).
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Diagnosis: 1 The nature of a disease ; the identification of an illness. 2 A conclusion or decision reached by diagnosis. The diagnosis is rabies . 3 The identification of any problem. The diagnosis was a plugged IV.
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Dialysis: The process of cleansing the blood by passing it through a special machine. Dialysis is necessary when the kidneys are not able to filter the blood. Dialysis allows patients with kidney failure a chance to live productive lives. There are two types of dialysis: hemodialysis and peritoneal dialysis. Each type of dialysis has advantages and disadvantages. Patients can often choose the type of long term dialysis that best matches their needs.

Disease: Illness or sickness often characterized by typical patient problems (symptoms) and physical findings (signs). Disruption sequence: The events that occur when a fetus that is developing normally is subjected to a destructive agent such as the rubella (German measles) virus.

DNA: Deoxyribonucleic acid. One of two types of molecules that encode genetic information. (The other is RNA . In humans DNA is the genetic material; RNA is transcribed from it. In some other organisms, RNA is the genetic material and, in reverse fashion, the DNA is transcribed from it.)
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Donor: The giver of a tissue or organ, for example, of blood or a kidney.

Edema: The swelling of soft tissues as a result of excess water accumulation.
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End stage: The last phase in the course of a progressive disease. As in end-stage liver disease, end-stage lung disease, end-stage renal disease, end-stage cancer, etc. The term "end stage" has come to replace "terminal" because somehow "end stage" seems more scientific and less despairing than "terminal." The only "stage" past "end stage" is usually death or a reprieve from it by a transplant.

Enzyme: A protein (or protein-based molecule) that speeds up a chemical reaction in a living organism. An enzyme acts as catalyst for specific chemical reactions , converting a specific set of reactants (called substrates) into specific products. Without enzymes, life as we know it would not exist.
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Enzymes: Proteins that act as a catalysts in mediating and speeding a specific chemical reaction .
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Esophageal: Pertaining to the esophagus.

Esophagus: The tube that connects the pharynx (throat) with the stomach. The esophagus lies between the trachea (windpipe) and the spine. It passes down the neck, pierces the diaphragm just to the left of the midline, and joins the cardiac (upper) end of the stomach. In an adult, the esophagus is about 25 centimeters (10 inches) long. When a person swallows, the muscular walls of the esophagus contract to push food down into the stomach. Glands in the lining of the esophagus produce mucus, which keeps the passageway moist and facilitates swallowing. Also known as the gullet or swallowing tube. From the Greek oisophagos, from oisein meaning to bear or carry + phagein, to eat.

Etiology: The study of the causes. For example, of a disorder.
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Evolution: The continuing process of change, especially in reference to natural selection.
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False negative: A result that appears negative but fails to reveal a situation. An example of a false negative: a particular test designed to detect cancer of the toenail is negative but the person has toenail cancer.
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False positive: A result that is erroneously positive when a situation is normal. An example of a false positive: a particular test designed to detect cancer of the toenail is positive but the person does not have toenail cancer.
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Family: 1. A group of individuals related by blood or marriage or by a feeling of closeness. 2. A biological classification of related plants or animals that is a division below the order and above the genus. 3. A group of genes related in structure and in function that descended from an ancestral gene. 4. A group of gene products similarly related in structure and function and of shared genetic descent. 5. Parents and their children. The most fundamental social group in humans.

Fatigue: A condition characterized by a lessened capacity for work and reduced efficiency of accomplishment, usually accompanied by a feeling of weariness and tiredness. Fatigue can be acute and come on suddenly or chronic and persist.
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FDA: The Food and Drug Administration, an agency within the U.S. Public Health Service, which is a part of the Department of Health and Human Services.
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Feet: The plural of foot, both an anatomic structure and a unit of measure.
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Female: The traditional definition of female was "an individual of the sex that bears young" or "that produces ova or eggs". However, things are not so simple today. Female can be defined by physical appearance, by chromosome constitution (see Female chromosome complement), or by gender identification. Female chromosome complement: The large majority of females have a 46, XX chromosome complement (46 chromosomes including two X chromosomes). A minority of females have other chromosome constitutions such as 45,X (45 chromosomes including only one X chromosome) and 47,XXX (47 chromosomes including three X chromosomes).

Fever : Although a fever technically is any body temperature above the normal of 98.6 degrees F. (37 degrees C.), in practice a person is usually not considered to have a significant fever until the temperature is above 100.4 degrees F (38 degrees C.).
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Flaviviridae: A family of viruses transmitted by mosquitos and ticks that cause some important diseases, including dengue, yellow fever, tick-borne encephalitis virus, and West Nile fever. The flaviviruses are positive-strand RNA viruses containing three structural proteins and a host-derived lipid bilayer.

Genetic: Having to do with genes and genetic information.

Genotype: The genetic constitution (the genome) of a cell, an individual or an organism. The genotype is distinct from its expressed features, or phenotype.
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Gland: 1. A group of cells that secrete a substance for use in the body. For example, the thyroid gland. 2. A group of cells that removes materials from the circulation. For example, a lymph gland.

Graft: Healthy skin, bone, or other tissue taken from one part of the body to replace diseased or injured tissue removed from another part of the body.
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Hair loss : Hair loss is the thinning of hair on the scalp. The medical term for hair loss is alopecia . Alopecia can be temporary or permanent. The most common form of hair loss occurs gradually and is referred to as “androgenetic alopecia,” meaning that a combination of hormones (androgens are male hormones) and heredity ( genetics ) is needed to develop the condition. Other types of hair loss include alopecia areata (patches of baldness that usually grow back), telogen effluvium (rapid shedding after childbirth, fever , or sudden weight loss); and traction alopecia (thinning from tight braids or ponytails).
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HCV: Hepatitis C virus.

Health: As officially defined by the World Health Organization, a state of complete physical, mental, and social well-being, not merely the absence of disease or infirmity.

Heart: The muscle that pumps blood received from veins into arteries throughout the body. It is positioned in the chest behind the sternum (breastbone; in front of the trachea, esophagus, and aorta; and above the diaphragm muscle that separates the chest and abdominal cavities. The normal heart is about the size of a closed fist, and weighs about 10.5 ounces. It is cone-shaped, with the point of the cone pointing down to the left. Two-thirds of the heart lies in the left side of the chest with the balance in the right chest.
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Heart disease: Any disorder that affects the heart. Sometimes the term "heart disease" is used narrowly and incorrectly as a synonym for coronary artery disease. Heart disease is synonymous with cardiac disease but not with cardiovascular disease which is any disease of the heart or blood vessels. Among the many types of heart disease, see, for example: Angina; Arrhythmia; Congenital heart disease; Coronary artery disease (CAD); Dilated cardiomyopathy; Heart attack (myocardial infarction); Heart failure; Hypertrophic cardiomyopathy; Mitral regurgitation; Mitral valve prolapse; and Pulmonary stenosis.

Hemodialysis: A medical procedure that uses a special machine (a dialysis machine) to filter waste products from the blood and to restore normal constituents to it. This shuffling of multiple substances is accomplished by virtue of the differences in the rates of their diffusion through a semipermeable membrane (a dialysis membrane).
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Hemolysis: The destruction of red blood cells which leads to the release of hemoglobin from within the red blood cells into the blood plasma .
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Hepatic: Having to do with the liver. Pronounced hi-'pa-tik. From the Latin hepaticus derived from the Greek hepar meaning (not too surprisingly) the liver.

Hepatic encephalopathy: Brain dysfunction directly due to liver dysfunction, most often recognized in advanced liver disease. Hepatic encephalopathy may cause disturbances of consciousness and progress to coma .
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Hepatitis: Inflammation of the liver from any cause.
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Hepatitis A: Inflammation of the liver caused by the hepatitis A virus (HAV). HAV is usually transmitted from person to person by food or drink that has been contaminated with the stool of a person with hepatitis A. This type of transmission is called "fecal-oral." The virus is more easily spread in areas where there are poor sanitary conditions or where good personal hygiene is not observed. In 2003 there were hepatitis A outbreaks in the US associated with eating raw or lightly cooked green onions (scallions). Casual contact, as in a school, office, or another work setting, does not spread the virus.
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Hepatitis B: Inflammation of the liver due to the hepatitis B virus (HBV), once thought to be passed only through blood products. It is now known that hepatitis B can also be transmitted via needle sticks, body piercing and tattooing using un sterilized instruments, the dialysis process, sexual and even less intimate close contact, and childbirth. Symptoms include fatigue, jaundice , nausea, vomiting, dark urine, light stools. Diagnosis is by blood test. Treatment is via anti-viral drugs and/or hepatitis B immunoglobulin (HBIG).
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Hepatitis C: Inflammation of the liver due to the hepatitis C virus (HCV), which is usually spread by blood transfusion, hemodialysis, and needle sticks. HCV causes most transfusion-associated hepatitis, and the damage it does to the liver can lead to cirrhosis and cancer. Transmission of the virus by sexual contact is rare. At least half of HCV patients develop chronic hepatitis C infection. Diagnosis is by blood test. Treatment is via anti-viral drugs. Chronic hepatitis C may be treated with interferon, sometimes in combination with anti-virals. There is no vaccine for hepatitis C. Previously known as non-A, non-B hepatitis.

Hepatitis C virus: A single-stranded RNA virus in the Flaviviridae family that causes hepatitis C. Abbreviated HCV. The HCV genome contains some 10,000 nucleotides and encodes a single polyprotein of 3,000 amino acids. HCV was discovered in 1989. Before that time, hepatitis C was referred to as non-A, non-B hepatitis.

Hepatocellular carcinoma: A tumor in which the cancer starts during adulthood in cells in the liver . Also called adult primary liver cancer.
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Hepatoma: Cancer originating in the liver, in liver cells. More often called hepatocarcinoma or hepatocellular carcinoma. From hepat-, the liver + -oma, tumor = a liver tumor.

Histology: The study of the form of structures seen under the microscope. Also called microscopic anatomy, as opposed to gross anatomy which involves structures that can be observed with the naked eye. Traditionally, both gross anatomy and histology (microscopic anatomy) have been studied in the first year of medical school in the U.S. The word "anatomy" comes from the Greek ana- meaning up or through + tome meaning a cutting. Anatomy was once a "cutting up" because the structure of the body was originally learned through dissecting it, cutting it up. The word "histology" came from the Greek "histo-" meaning tissue + "logos", treatise. Histology was a treatise about the tissues of the body and the cells thereof.

HIV: Acronym for the Human Immunodeficiency Virus , the cause of AIDS (acquired immunodeficiency syndrome). HIV has also been called the human lymphotropic virus type III, the lymphadenopathy-associated virus and the lymphadenopathy virus . No matter what name is applied, it is a retrovirus. (A retrovirus has an RNA genome and a reverse transcriptase enzyme. Using the reverse transcriptase , the virus uses its RNA as a template for making complementary DNA which can integrate into the DNA of the host organism).
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Host: 1. The organism from which a parasite obtains its nutrition and/or shelter.
2. An organism or cell culture in which a virus can replicate itself.
3. The transplant recipient of a tissue or organ graft.

Human immunodeficiency virus : HIV, the cause of AIDS. HIV has also been called the human lymphotropic virus type III, the lymphadenopathy-associated virus and the lymphadenopathy virus. No matter what name is applied, it is a retrovirus. (A retrovirus has an RNA genome and a reverse transcriptase enzyme. Using the reverse transcriptase, the virus uses its RNA as a template for making complementary DNA which can integrate into the DNA of the host organism). Although the American research Robert Gallo at the National Institutes of Health believed he was the first to find HIV, it is now generally accepted that the French physician Luc Montagnier (1932-) and his team at the Pasteur Institute discovered HIV in 1983- 84.
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Hypertension: High blood pressure , defined as a repeatedly elevated blood pressure exceeding 140 over 90 mmHg -- a systolic pressure above 140 with a diastolic pressure above 90.
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Immune: Protected against infection. The Latin immunis means free, exempt.

Immune response: Any reaction by the immune system.

Immune system: A complex system that is responsible for distinguishing us from everything foreign to us, and for protecting us against infections and foreign substances. The immune system works to seek and kill invaders.
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Immunocompromised: Having an immune system that has been impaired by disease or treatment.
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Immunodeficiency: Inability to mount a normal immune response. Immunodeficiency can be due to a genetic disease or acquired as in AIDS due to HIV.
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Immunoglobulin: A protein produced by plasma cells and lymphocytes and characteristic of these types of cells. Immunoglobulins play an essential role in the body's immune system. They attach to foreign substances, such as bacteria, and assist in destroying them. Immunoglobulin is abbreviated Ig. The classes of immunoglobulins are termed immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM), immunoglobulin D (IgD) and immunoglobulin E (IgE).

Indicate: In medicine, to make a treatment or procedure advisable because of a particular condition or circumstance. For example, certain medications are indicated for the treatment of hypertension during pregnancy while others are contraindicated.

Infection: The growth of a parasitic organism within the body. (A parasitic organism is one that lives on or in another organism and draws its nourishment therefrom.) A person with an infection has another organism (a "germ") growing within him, drawing its nourishment from the person.
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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 .
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Influenza: The flu is caused by viruses that infect the respiratory tract which are divided into three types, designated A, B, and C. Most people who get the flu recover completely in 1 to 2 weeks, but some people develop serious and potentially life-threatening medical complications, such as pneumonia. Much of the illness and death caused by influenza can be prevented by annual influenza vaccination.

Injury: Harm or hurt. The term "injury" may be applied in medicine to damage inflicted upon oneself as in a hamstring injury or by an external agent on as in a cold injury. The injury may be accidental or deliberate, as with a needlestick injury. The term "injury" may be synonymous (depending on the context) with a wound or with trauma.

Insomnia: The perception or complaint of inadequate or poor-quality sleep because of one or more of the following: difficulty falling asleep; waking up frequently during the night with difficulty returning to sleep; waking up too early in the morning; or unrefreshing sleep. Insomnia is not defined by the number of hours of sleep a person gets or how long it takes to fall asleep. Individuals vary normally in their need for, and their satisfaction with, sleep. Insomnia may cause problems during the day, such as tiredness, a lack of energy, difficulty concentrating, and irritability.
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Insulin: A natural hormone made by the pancreas that controls the level of the sugar glucose in the blood. Insulin permits cells to use glucose for energy. Cells cannot utilize glucose without insulin.
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Interferon : A naturally occurring substance that interferes with the ability of viruses to reproduce. Interferon also boosts the immune system.
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Itching: An uncomfortable sensation in the skin that feels as if something is crawling on the skin or in the skin, and makes the person want to scratch the affected area.
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Jaundice: Yellow staining of the skin and sclerae (the whites of the eyes) by abnormally high blood levels of the bile pigment bilirubin . The yellowing extends to other tissues and body fluids. Jaundice was once called the "morbus regius" (the regal disease) in the belief that only the touch of a king could cure it.
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Joint: A joint is the area where two bones are attached for the purpose of motion of body parts. A joint is usually formed of fibrous connective tissue and cartilage. An articulation or an arthrosis is the same as a joint.
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Kidney: One of a pair of organs located in the right and left side of the abdomen which clear "poisons" from the blood, regulate acid concentration and maintain water balance in the body by excreting urine. The kidneys are part of the urinary tract. The urine then passes through connecting tubes called "ureters" into the bladder. The bladder stores the urine until it is released during urination.

Laboratory: A place for doing tests and research procedures and preparing chemicals, etc. Although "laboratory" looks very like the Latin "laboratorium" (a place to labor, a work place), the word "laboratory" came from the Latin "elaborare" (to work out, as a problem, and with great pains), as evidenced by the Old English spelling "elaboratory" designating "a place where learned effort was applied to the solution of scientific problems."
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Leukopenia: Lower than the normal amount of white blood cells.

Lichen planus : A common skin disease with small itchy pink or purple spots on the arms or legs.
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Liver: An organ in the upper abdomen that aids in digestion and removes waste products and worn-out cells from the blood. The liver is the largest solid organ in the body. The liver weighs about three and a half pounds (1.6 kilograms). It measures about 8 inches (20 cm) horizontally (across) and 6.5 inches (17 cm) vertically (down) and is 4.5 inches (12 cm) thick.

Liver biopsy : A procedure in which a small sample of the liver is removed for the diagnosis of abnormal liver conditions.
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Liver disease: Liver disease refers to any disorder of the liver. The liver is a large organ in the upper right abdomen that aids in digestion and removes waste products from the blood.
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Liver transplant: Surgery to remove a diseased liver and replace it with a healthy liver (or part of one) from a donor . The most common reasons for liver transplantation in children is biliary atresia (a disease in which the ducts that carry bile out of the liver are missing or damaged) while in adults the most common reason for a liver transplant is cirrhosis (a disease in which healthy liver cells are killed and replaced with scar tissue ).
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Lymph: An almost colorless fluid that travels through vessels called lymphatics in the lymphatic system and carries cells that help fight infection and disease.

Lymphoma: Tumor of the lymphoid tissue. Diagnosis is by biopsy. Treatment may be chemotherapy, radiation, surgery, or medication, depending on the age of the patient and type of tumor.

Marker: A piece of DNA that lies on a chromosome so close to a gene that the marker and the gene are inherited together. A marker is thus an identifiable heritable spot on a chromosome. A marker can be an expressed region of DNA (a gene) or a segment of DNA with no known coding function. All that matters is that the marker can be detected and trailed.
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Medication: 1. A drug or medicine. 2. The administration of a drug or medicine. (Note that "medication" does not have the dangerous double meaning of "drug.")

Microscopic: So small it cannot be seen without the aid of microscope. As opposed to macroscopic (large enough to be seen with naked eye). A tiny tumor is microscopic while a big tumor is macroscopic.
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Mother: (1) The female parent. (2) To produce offspring as a female. To attribute the maternity of. (3) A cell or other structure from which similar cells or structures are formed. Accordingly, such a cell might be referred to as the mother cell.(4) To provide maternal protection, guidance, and nurturing to children.
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Mouth: 1. The upper opening of the digestive tract, beginning with the lips and containing the teeth, gums, and tongue. Foodstuffs are broken down mechanically in the mouth by chewing and saliva is added as a lubricant. Saliva contains amylase, an enzyme that digests starch. 2. Any opening or aperture in the body. The mouth in both senses of the word is also called the os, the Latin word for an opening, or mouth. The o in os is pronounced as in hope. The genitive form of os is oris from which comes the word oral.

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."

Muscular: Having to do with the muscles. Also, endowed with above average muscle development. Muscular system refers to all of the muscles of the body collectively.

Mutation: A permanent change, a structural alteration, in the DNA or RNA . In humans and many other organisms, mutations occur in DNA. However, in retroviruses like HIV , mutations occur in RNA which is the genetic material of retroviruses.
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Nausea: Nausea is the urge to vomit. It can be brought by many causes including, systemic illnesses, such as influenza, medications, pain, and inner ear disease.

Necrosis: The death of living cells or tissues. Necrosis can be due, for example, to ischemia (lack of blood flow). From the Greek "nekros" (dead body).

Needle stick: See: Needlestick injury.

Nerve: A bundle of fibers that uses chemical and electrical signals to transmit sensory and motor information from one body part to another. See: Nervous system.

Neuropathy: Any and all disease or malfunction of the nerves.

NIH: The National Institutes of Health. The NIH is an important U.S. health agency. It is devoted to medical research. Administratively under the Department of Health and Human Services (HHS), the NIH consists of 20-some separate Institutes and Centers. NIH's program activities are represented by these Institutes and Centers.
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Nucleic acid: One of the family of large molecules which includes deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Nucleic acids were so named because they were first found in the nucleus of cells, but they have since been discovered also to exist outside the nucleus. The two chief types of nucleic acids are, indeed:

• DNA ( deoxyribonucleic acid ) which contains the hereditary information in humans and
• RNA ( ribonucleic acid ) which delivers the instructions coded in this information to the cell's protein manufacturing sites.

Nucleic acids: See nucelic acid.

Onset: In medicine, the first appearance of the signs or symptoms of an illness as, for example, the onset of rheumatoid arthritis . There is always an onset to a disease but never to the return to good health. The default setting is good health.
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Open wound: An injury that is exposed due to broken skin. An open wound is at high risk for infection.
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Organ: A relatively independent part of the body that carries out one or more special functions. The organs of the human body include the eye, ear, heart, lungs, and liver.

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.
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Palpable: Something that can be felt or touched. For example, a palpable tumor is one that can be felt. From the Latin "palpare" (to stroke or to pat).
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PEG: Stands for percutaneous endoscopic gastrostomy, a surgical procedure for placing a feeding tube without having to perform an open laparotomy (operation on the abdomen). The aim of PEG is to feed those who cannot swallow. PEG may be done by a surgeon, otolaryngologist (ENT specialist) or gastroenterologist (GI specialist). It is done in a. hospital or outpatient surgical facility. Local anesthesia (usually lidocaine or another spray) is used to anesthetize the throat. An endoscope (a flexible, lighted instrument) is passed through the mouth, throat and esophagus to the stomach. The surgeon then makes a small incision (cut) in the skin of the abdomen and pushes an intravenous cannula (an IV tube) through the skin into the stomach and sutures (ties) it in place. The patient can usually go home the same day or the next morning. Possible complications include wound infection (as in any kind of surgery) and dislodging or malfunction of the tube. Percutaneous endoscopic gastrostomy may be a mouthful (as a term) but it describes the procedure accurately. A gastrostomy (a surgical opening into the stomach) is made percutaneously (through the skin) using an endoscope to put the feeding tube in place. PEG takes less time, carries less risk and costs less than a classic surgical gastrostomy which requires opening the abdomen.

Piercing: Using a sharp instrument, usually a needle, to make a temporary or permanent hole through an earlobe or other body part. Humans have practiced piercing for body decoration since prehistoric times. Unless it is performed using a sterile needle (preferably disposable), piercing can carry a risk of infection . A piercing should be kept clean; antibiotic cream may be applied if the area becomes inflamed.
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Platelet: An irregular, disc-shaped element in the blood that assists in blood clotting. During normal blood clotting, the platelets clump together (aggregate). Although platelets are often classed as blood cells, they are actually fragments of large bone marrow cells called megakaryocytes.

Platelet count: The calculated number of platelets in a volume of blood, usually expressed as platelets per cubic millimeter (cmm) of whole blood. Platelets are the smallest cell-like structures in the blood and are important for blood clotting and plugging damaged blood vessels. Platelet counts are usually done by laboratory machines that also count other blood elements such as the white and red cells. They can also be counted by use of a microscope. Normal platelet counts are in the range of 150,000 to 400,000 per microliter (or 150 - 400 x 10⁹ per liter). These values many vary slightly between different laboratories.

Porphyria: A diverse group of diseases in which the production of heme is disrupted. Porphyria is derived from the Greek word "porphyra", which means purple. When heme production is faulty, porphyrins are overproduced and lend a reddish-purple color to urine. All forms of porphyrias are inherited. The key clinical features are skin sensitivity to sunlight and/or by intermittent acute attacks of abdominal and nerve pain.
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Porphyria cutanea tarda: Literally, the late skin form of porphyria , a genetic photosensitive (light-sensitive) skin disease with onset in adult life with substances called uroporphyrins in the urine due to a deficiency of uroporphyrinogen decarboxylase (UROD), an enzyme required for the synthesis of heme (part of hemoglobin , the pigment in red blood cells that carries oxygen ). The hallmarks of porphyria cutanea tarda (PCT) are blisters which become ulcerated in areas of the skin exposed to sunlight, especially on the face, ears and dorsum (back) of the hands. The affected areas of skin also tend to be fragile and show hyperpigmentation (excess pigment) and hypertrichosis (excess hair).
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Pregnancy: The state of carrying a developing embryo or fetus within the female body. This condition can be indicated by positive results on an over-the-counter urine test, and confirmed through a blood test, ultrasound, detection of fetal heartbeat, or an X-ray. Pregnancy lasts for about nine months, measured from the date of the woman's last menstrual period (LMP). It is conventionally divided into three trimesters, each roughly three months long.
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Pregnant: The state of carrying a developing fetus within the body.
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Prevalence: The proportion of individuals in a population having a disease. Prevalence is a statistical concept referring to the number of cases of a disease that are present in a particular population at a given time.
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Prognosis: 1. The expected course of a disease .
2. The patient's chance of recovery.
The prognosis predicts the outcome of a disease and therefore the future for the patient . His prognosis is grim, for example, while hers is good.
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Progressive: Increasing in scope or severity. Advancing. Going forward. In medicine, a disease that is progressive is going from bad to worse.
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Prospective: Looking forward. A prospective study or a prospective clinical trial is one in which the participants are identified and then followed forward in time.
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Prospective study: A study in which the subjects are identified and then followed forward in time.
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Protein: A large molecule composed of one or more chains of amino acids in a specific order determined by the base sequence of nucleotides in the DNA coding for the protein.
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Proteins: Large molecules composed of one or more chains of amino acids in a specific order determined by the base sequence of nucleotides in the DNA coding for the protein.
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Psychiatric: Pertaining to or within the purview of psychiatry , the medical specialty concerned with the prevention, diagnosis , and treatment of mental illness.
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Purpura: 1. A hemorrhagic area in the skin. The area of bleeding within the skin, by definition, is greater than 3 millimeters in diameter. The appearance of the purpura depends on age of the lesion. Early purpura is red and becomes darker, then purple, and brown-yellow as it fades. Purpura does not blanch when touched.
2. A condition characterized by purpura such as immune thrombocytopenic purpura and Schönlein-Henoch purpura.

Qualitative: Having to do with quality. In contrast to quantitative (which pertains to quantity, the amount).
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Quality of life: An important consideration in medical care, quality of life refers to the patient's ability to enjoy normal life activities. Some medical treatments can seriously impair quality of life without providing appreciable benefit, while others greatly enhance quality of life.

Quantitative: Having to do with quantity or with the amount.
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Range: In medicine and statistics, the difference between the lowest and highest numerical values. For example, if five premature infants are born weighing two, three, four, four, and five pounds respectively, the range of their birth weights is two to five pounds.

Rash : Breaking out (eruption) of the skin. Medically, a rash is referred to as an exanthem.
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Raynaud's phenomenon: A condition resulting in discoloration of fingers and/or toes when a person is exposed to changes in temperature (cold or hot) or emotional events.
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Recombinant: A person with a new combination of genes, a combination of genes not present in either parent, due to parental recombination of those genes.
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Recurrence: The return of a sign, symptom or disease after a remission. The reappearance of cancer cells at the same site or in another location is, unfortunately, a familiar form of recurrence.
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Recurrent: Back again. A recurrent fever is a fever that has returned after an intermission: a recrudescent fever.

Red blood cells: The blood cells that carry oxygen. Red cells contain hemoglobin and it is the hemoglobin which permits them to transport oxygen (and carbon dioxide). Hemoglobin, aside from being a transport molecule, is a pigment. It gives the cells their red color (and their name).
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Regimen: With the accent on the first syllable (reg as in Reggie Jackson), a regimen is a plan, a regulated course such as a diet, exercise or treatment, designed to give a good result. A low-salt diet is a regimen.

Rehabilitation: The process of restoration of skills by a person who has had an illness or injury so as to regain maximum self-sufficiency and function in a normal or as near normal manner as possible. For example, rehabilitation after a stroke may help the patient walk again and speak clearly again.
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Rejection: In transplantation biology, the refusal by the body to accept transplanted cells, tissues or organs. For example, a kidney transplanted may be rejected.

Relapse: The return of signs and symptoms of a disease after a patient has enjoyed a remission . For example, after treatment a patient with cancer of the colon went into remission with no sign or symptom of the tumor, remained in remission for 4 years, but then suffered a relapse and had to be treated once again for colon cancer.
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Remission: Disappearance of the signs and symptoms of cancer or other disease. When this happens, the disease is said to be "in remission." A remission can be temporary or permanent.
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Renal: Having to do with the kidney. From the Latin renes (the kidneys), which gave the French les reins which mean both the kidneys and the lower back.

Replication: A turning back, repetition, duplication, reproduction.
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Reproduction: The production of offspring. Reproduction need not be sexual. Yeast can reproduce by budding.
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Resistance: Opposition to something, or the ability to withstand it. For example, some forms of staphylococcus are resistant to treatment with antibiotics.
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Retrospective: Looking backward on the past, on what has already taken place. A retrospective study looks backward in time, usually using medical records and interviews with patients who already known to have or have had a disease.

Retrospective study: In medicine, a study that looks backward in time, usually using medical records and interviews with patients who already known to have a disease.
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Rheumatoid factor: Rheumatoid factor is an antibody that is measurable in the blood. It is commonly used as a blood test for the diagnosis of rheumatoid arthritis. Rheumatoid factor is present in about 80% of adults (but a much lower proportion of children) with rheumatoid arthritis. It is also present in patients with other connective tissue diseases (such as systemic lupus erythematosus) and in some with infectious diseases (such as infectious hepatitis).

RNA: Short for ribonucleic acid, a nucleic acid molecule similar to DNA but containing ribose rather than deoxyribose. RNA is formed upon a DNA template. There are several classes of RNA molecules.
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RNA polymerase: A polymerase is an enzyme that catalyzes the joining of many smaller molecules (called monomers) to form a big molecule (a macromolecule). RNA polymerase is a unique enzyme that makes (synthesizes) the macromolecule RNA using DNA as the template.

RNA virus: A virus in which the genetic material is RNA. The RNA may be either double- or single-stranded.
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RT-PCR: RT-PCR (Reverse transcriptase-polymerase chain reaction) is a highly sensitive technique for the detection and quantitation of mRNA (messenger RNA). The technique consists of two parts:
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Safe sex: 1. A sexual practice designed to reduce the risk of catching sexually transmitted infections (STIs). 2. A sexual practice that does not involve the exchange of bodily fluids, including blood, sperm, vaginal secretions, and saliva, to avoid AIDS and other sexually transmitted infections. 3. Sex without penetration, or sex using condoms and Nonoxynol-9 spermacide, and/or vaginal dams, with consistency.
In reality, no matter which meaning one ascribes to safe sex, "safer sex" is a more apt term.

Section: 1) In anatomy, a slice of tissue. A biopsy obtained by surgery is usually sectioned (sliced), and these sections are inspected under a microscope. 2) In obstetrics, short for Caesarian section. 3) In surgery, the division of tissue during an operation.

Semen: The fluid that is released through the penis during orgasm. Semen is made up of fluid and of sperm. The fluid comes from the prostate, seminal vesicle and other sex glands. The sperm are manufactured in the testicles. The seminal fluid helps transport the sperm during orgasm. Seminal fluid contains sugar as an energy source for sperm.
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Sense: In biology and medicine, the faculty of sensory reception. The ability to convey specific types of external or internal stimuli to the brain and perceive them. Sensory reception occurs through a process known as transduction in which stimuli are converted into nerve impulses which are relayed to the brain.
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Sensitivity: 1. In psychology, the quality of being sensitive. As, for example, sensitivity training, training in small groups to develop a sensitive awareness and understanding of oneself and of ones relationships with others. 2. In disease epidemiology, the ability of a system to detect epidemics and other changes in disease occurrence. 3. In screening for a disease, the proportion of persons with the disease who are correctly identified by a screening test. 4. In the definition of a disease, the proportion of persons with the disease who are correctly identified by defined criteria.

Serum: The clear liquid that can be separated from clotted blood. Serum differs from plasma, the liquid portion of normal unclotted blood containing the red and white cells and platelets. It is the clot that makes the difference between serum and plasma.
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Side effects: Problems that occur when treatment goes beyond the desired effect. Or problems that occur in addition to the desired therapeutic effect.
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Skin: The skin is the body's outer covering. It protects us against heat and light, injury, and infection. It regulates body temperature and stores water, fat, and vitamin D. Weighing about 6 pounds, the skin is the body's largest organ. It is made up of two main layers; the outer epidermis and the inner dermis.

Stage: As regards cancer , the extent of a cancer, especially whether the disease has spread from the original site to other parts of the body. See also: Staging .
See the entire definition of Stage

Standard of care: 1. A diagnostic and treatment process that a clinician should follow for a certain type of patient, illness, or clinical circumstance. Adjuvant chemotherapy for lung cancer is "a new standard of care, but not necessarily the only standard of care." (New England Journal of Medicine, 2004)
2. In legal terms, the level at which the average, prudent provider in a given community would practice. It is how similarly qualified practitioners would have managed the patient's care under the same or similar circumstances. The medical malpractice plaintiff must establish the appropriate standard of care and demonstrate that the standard of care has been breached.

Steroid: A general class of chemical substances that are structurally related to one another and share the same chemical skeleton (a tetracyclic cyclopenta[a]phenanthrene skeleton).
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Symptomatic: 1 With symptoms, as a symptomatic infection. 2 Characteristic, as behavior symptomatic of Huntington disease. 3 Directed at the symptoms, as symptomatic treatment.

Syphilis: A sexually transmitted disease caused by Treponema pallidum, a microscopic organism called a spirochete. This worm-like, spiral-shaped organism infects people by burrowing into the moist mucous membranes of the mouth or genitals. From there, the spirochete produces a non-painful ulcer known as a chancre. There are three stages of syphilis:
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Testicles: The testicles (also called testes or gonads) are the male sex glands. They are located behind the penis in a pouch of skin called the scrotum. The testicles produce and store sperm, and they are also the body's main source of male hormones (testosterone). These hormones control the development of the reproductive organs and other male characteristics, such as body and facial hair, low voice, and wide shoulders.

Therapy: The treatment of disease .
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Thymus: A lymphoid organ situated in the center of the upper chest just behind the sternum (breastbone). It is in the thymus that lymphocytes mature, multiply, and become T cells . (That is why they are called T cells. The T is for thymus.)
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Thymus gland: See: Thymus.

Thyroid: 1. The thyroid gland. Also, pertaining to the thyroid gland. 2. A preparation of the thyroid gland used to treat hypothyroidism. 3. Shaped like a shield. (The thyroid gland was so-named by Thomas Wharton in 1656 because it was shaped like an ancient Greek shield.)

Thyroid gland: A gland that makes and stores hormones that help regulate the heart rate, blood pressure, body temperature, and the rate at which food is converted into energy. Thyroid hormones are essential for the function of every cell in the body. They help regulate growth and the rate of chemical reactions ( metabolism ) in the body. Thyroid hormones also help children grow and develop.
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Tissue: A tissue in medicine is not like a piece of tissue paper. It is a broad term that is applied to any group of cells that perform specific functions. A tissue in medicine need not form a layer. Thus,

• The bone marrow is a tissue;
• Connective tissue consists of cells that make up fibers in the framework supporting other body tissues; and
• Lymphoid tissue is the part of the body's immune system that helps protect it from bacteria and other foreign entities.

TMA: See Trimethylaminuria

Transcription: Making an RNA copy from a sequence of DNA (a gene). Transcription is the first step in gene expression.

Transfusion: The transfer of blood or blood products from one person (the donor) into another person (the recipient's) bloodstream. In most situations, this is done as a lifesaving maneuver to replace blood cells or blood products lost through severe bleeding. Transfusion of your own blood (autologous) is the safest method but requires planning ahead and not all patients are eligible. Directed donor blood allows the patient to receive blood from known donors. Volunteer donor blood is usually most readily available and, when properly tested has a low incidence of adverse events.
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Transplant: The grafting of a tissue from one place to another, just as in botany a bud from one plant might be grafted onto the stem of another. The transplanting of tissue can be from one part of the patient to another (autologous transplantation), as in the case of a skin graft using the patient's own skin; or from one patient to another (allogenic transplantation), as in the case of transplanting a donor kidney into a recipient.

Urine: Liquid waste. The urine is a clear, transparent fluid. It normally has an amber color. The average amount of urine excreted in 24 hours is from 40 to 60 ounces (about 1,200 cubic centimeters). Chemically, the urine is mainly an aqueous (watery) solution of salt (sodium chloride) and substances called urea and uric acid. Normally, it contains about 960 parts of water to 40 parts of solid matter. Abnormally, it may contain sugar (in diabetes), albumen (a protein) (as in some forms of kidney disease), bile pigments (as in jaundice), or abnormal quantities of one or another of its normal components.

Vasculitis: Plural: vasculitides. A general term for a group of diseases that feature inflammation of the blood vessels. Each of these diseases is defined by characteristic distributions of blood vessel involvement, patterns of organ involvement, and laboratory test abnormalities. The causes of these vasculitis diseases are usually not known, but immune system abnormality is a common feature.
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Viable: Capable of life. For example, a viable premature baby is one who is able to survive outside the womb.

Viral: Of or pertaining to a virus. For example, "My daughter has a viral rash ."
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Viral infection: Infection caused by the presence of a virus in the body. Depending on the virus and the person's state of health, various viruses can infect almost any type of body tissue, from the brain to the skin. Viral infections cannot be treated with antibiotics; in fact, in some cases the use of antibiotics makes the infection worse. The vast majority of human viral infections can be effectively fought by the body's own immune system, with a little help in the form of proper diet, hydration, and rest. As for the rest, treatment depends on the type and location of the virus, and may include anti-viral or other drugs.

Viremia: The presence of a virus in the blood. Viremia is analogous to bacteremia (the presence of bacteria in the blood) and parasitemia (the presence of a parasite in the blood). Viremia, bacteremia and parasitemia are all forms of sepsis (bloodstream infection).
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Virus: A microorganism smaller than a bacteria, which cannot grow or reproduce apart from a living cell. A virus invades living cells and uses their chemical machinery to keep itself alive and to replicate itself. It may reproduce with fidelity or with errors (mutations)-this ability to mutate is responsible for the ability of some viruses to change slightly in each infected person, making treatment more difficult.
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Viruses: Small living particles that can infect cells and change how the cells function. Infection with a virus can cause a person to develop symptoms. The disease and symptoms that are caused depend on the type of virus and the type of cells that are infected.

Wasting: 1. Gradual loss (for example, of weight), deterioration, emaciation. As in a wasting disease. 2. Excessive depletion. As in salt wasting, the excessive loss of salt.
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Weight loss: Weight loss is a decrease in body weight resulting from either voluntary (diet, exercise) or involuntary (illness) circumstances. Most instances of weight loss arise due to the loss of body fat, but in cases of extreme or severe weight loss, protein and other substances in the body can also be depleted. Examples of involuntary weight loss include the weight loss associated with cancer, malabsorption (such as from chronic diarrheal illnesses ), and chronic inflammation (such as with rheumatoid arthritis).

White blood cell: One of the cells the body makes to help fight infections. There are several types of white blood cells ( leukocytes ). The two most common types are the lymphocytes and neutrophils (also called polymorphonuclear leukocytes, PMNs, or "polys").
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White blood cell count (leukocyte count): The number of white blood cells (WBCs) in the blood. The WBC is usually measured as part of the CBC ( complete blood count ). White blood cells are the infection-fighting cells in the blood and are distinct from the red (oxygen-carrying) blood cells known as erythrocytes. There are different types of white blood cells, including neutrophils (polymorphonuclear leukocytes ; PMNs), band cells (slightly immature neutrophils), T-type lymphocytes (T cells), B-type lymphocytes (B cells), monocytes, eosinophils, and basophils. All the types of white blood cells are reflected in the white blood cell count. The normal range for the white blood cell count varies between laboratories but is usually between 4,300 and 10,800 cells per cubic millimeter of blood. This can also be referred to as the leukocyte count and can be expressed in international units as 4.3 - 10.8 x 109 cells per liter.
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Yellow fever: An acute systemic (bodywide) illness caused by a virus called a Flavivirus . In severe cases, the viral infection causes a high fever, bleeding into the skin, and necrosis (death) of cells in the kidney and liver. The damage done to the liver from the virus results in severe jaundice which yellows the skin. Hence, the "yellow" in "yellow fever."
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From the Doctors at MedicineNet.com

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