Medications

Rotator cuff: A group of four tendons that stabilize the shoulder joint. Each of the four tendons hooks up to a muscle that moves the shoulder in a specific direction. The four muscles whose tendons form the rotator cuff are: The subscapularis mu...

Rossi counter - Medical

Rossi counter: An instrument used to measure the energy deposited by radiation in microscopic sites such as cells. Named for its creator Harald H. Rossi (1917-2000), a radiobiophysicist who contributed much to our ability to measure minute amounts of...

Roseola infantum - Medical

Roseola infantum: Roseola infantum is another name for roseola, also formally called roseola infantilis. The following is a brief rundown on roseola: Cause: Roseola is caused by a virus called human herpesvirus 6 (HHV-6) and, possibly, human ...

Roseola infantilis - Medical

Roseola infantilis: Roseola infantilis is another name for roseola, also formally called roseola infantum. The following is a brief rundown on roseola: Cause: Roseola is caused by a virus called human herpesvirus 6 (HHV-6) and, possibly, human herp...

Roseola - Medical

Roseola: Roseola is a childhood illness caused by virus infection characterized by high fevers followed by a skin rash. Roseola is also formally called roseola infantum or roseola infantilis. The following is a brief summary of roseola: Cause: Ro...

Rosary pea - Medical

Rosary pea: See: Abrin. Last Editorial Review: 12/4/2003 Abrin: A phytotoxin (plant poison) found in the seeds of a plant called the rosary pea or jequirity pea. These seeds are red with a black spot covering one end. Abrin is similar to ricin,...

Rorschach test - Medical

Rorschach test: A psychological test involving inkblots. The inkblots are used to determine what a person perceives (reads into) in the enigmatic and highly ambiguous shapes. Ten standardized blots are shown one at a time to a subject and their resp...

Rooting reflex - Medical

Rooting reflex: A reflex seen in newborn babies, who automatically turn their face toward the stimulus and make sucking (rooting) motions with the mouth when the cheek or lip is touched. The rooting reflex helps to ensure breastfeeding.Last Ed...

Roofies - Medical

Roofies: Street term for Rohypnol.Last Editorial Review: 4/21/2003 Rohypnol: The trade name for flunitrazepam, which has been abused as a "date rape" drug. Rohypnol produces sedative-hypnotic effects including muscle relaxation and amnesia. It can...

Roofer's knee - Medical

Roofer's knee: See prepatellar bursitis. Last Editorial Review: 6/15/2007 Prepatellar bursitis: Inflammation of the bursa that is positioned in front of the kneecap (patella). Prepatellar bursitis commonly occurs as a result of repeated trauma t...

Romano-Ward syndrome - Medical

Romano-Ward syndrome: See: Long QT syndrome.Last Editorial Review: 4/5/2003 Long QT syndrome: An inherited defect in heart rhythm that predisposes to syncope without warning (sudden fainting spells), dizziness, palpitations, seizures and sudden deat...

ROMA - Medical

ROMA: Representational oligonucleotide microarray analysis. A method for the detection of genomic aberrations between any two samples of DNA. ROMA measures the relative concentration of DNA in the two samples by hybridizing differentially labeled sam...

Rohypnol - Medical

Rohypnol: The trade name for flunitrazepam, which has been abused as a "date rape" drug. Rohypnol produces sedative-hypnotic effects including muscle relaxation and amnesia. It can produces physical and psychological dependence and can be lethal when...

Roentgenology - Medical

Roentgenology: Radiology, the science of radiation and, specifically, the use of both ionizing (like X-ray) and nonionizing (like ultrasound) modalities for the diagnosis and treatment of disease. Roentgenology is named for Wilhelm Conrad Ro...

Roentgen, Wilhelm - Medical

Roentgen, Wilhelm: Wilhelm Conrad Rontgen (1845-1923), German-born, Dutch-educated physicist who first observed and documented X-rays on November 8, 1895. He made this seminal discovery by accident while experimenting with a set of cathode ray inst...

Roentgen ray - Medical

Roentgen ray: Term coined around 1890 that preceded X-ray and is now synonymous with it. Named for Wilhelm Roentgen, a German professor of physics. Roentgen wanted to prove his hypothesis that cathode rays could penetrate substances besides air. When...

Roentgen - Medical

Roentgen: An international unit of X-radiation or gamma-radiation. Abbreviated R. Named for Wilhelm Roentgen. Last Editorial Review: 4/27/2011 5:27:15 PM...

Rodney K. Beals - Medical

Rodney K. Beals: See: Beals, Rodney K.Last Editorial Review: 11/17/2004 Beals, Rodney K.: (1931- ) American orthopaedic surgeon who described a number of congenital malformation syndromes. After graduating from the University of Oregon Medical Sc...

Rodenticide - Medical

Rodenticide: A chemical or other agent used to destroy rats or other rodent pests or prevent them from damaging food, crops, etc. Rat poison is a familiar rodenticide. Last Editorial Review: 12/4/2003...

Rodenticidal - Medical

Rodenticidal: Capable of killing rats or other rodent pests or preventing them from damaging food, crops, etc.Last Editorial Review: 12/4/2003...

Rodbell, Martin - Medical

Rodbell, Martin: (1925-1998) American biochemist and molecular endocrinologist who shared the Nobel Prize in 1994 in Physiology or Medicine for his discovery of G-proteins and the principles of signal transduction in cellular communication. Martin R...

Rodbell - Medical

Rodbell: See: Rodbell, MartinLast Editorial Review: 10/19/2003 Rodbell, Martin: (1925-1998) American biochemist and molecular endocrinologist who shared the Nobel Prize in 1994 in Physiology or Medicine for his discovery of G-proteins and the princi...

Rod Beals - Medical

Rod Beals: See: Beals, Rodney K.Last Editorial Review: 11/17/2004 Beals, Rodney K.: (1931- ) American orthopaedic surgeon who described a number of congenital malformation syndromes. After graduating from the University of Oregon Medical School i...

Rod - Medical

Rod: A type of specialized light-sensitive cell (photoreceptor) in the retina of the eye that provides side vision and the ability to see objects in dim light (night vision). By contrast, the cones are the retinal photoreceptors that provide sharp...

Rocky Mountain wood tick - Medical

Rocky Mountain wood tick: A tick that can transmit R. rickettsii, the agent of Rocky Mountain spotted fever. This tick is found in the Rocky Mountain states and in southwestern Canada. The life cycle of this tick may require up to 2 to 3 years for co...

Rocky Mountain spotted fever (RMSF) - Medical

Rocky Mountain spotted fever (RMSF): An acute febrile (feverish) disease initially recognized in the Rocky Mountain states, caused by Rickettsia rickettsii transmitted by hard-shelled (ixodid) ticks. Occurs only in the Western Hemisphere. Anyone fre...

Rock (drug) - Medical

Rock (drug): A street name given to cocaine that has been processed from cocaine hydrochloride to a ready-to-use free base for smoking. Rather than requiring the more volatile method of processing cocaine using ether, rock cocaine (also called crack)...

Rochalimaea quintana - Medical

Rochalimaea quintana: Now preferentially referred to as Bartonella quintana, this is an unusual rickettsial organism that can multiply within the gut of the body louse and then can be transmitted to humans. Transmission to people can occur by rubbin...

Robust - Medical

Robust: In statistics, a term applied to a test or procedure that is not seriously disturbed by violations of the assumptions on which it is based. For example, it was an "unexpected and robust difference in the rate of events." (Dr. Harold J. Burst...

Robotripping - Medical

Robotripping: Street name for the high produced by abuse of the cough syrup Robitussin which contains dextromethorphan. Last Editorial Review: 6/16/2004 Dextromethorphan: An oral cough suppressant available in the US without a prescription b...