Category: C

The production of motion pictures or video tapes as a dynamic study of biological function during an x-ray examination. Often a radio-opaque dye is injected or injested and its progress is followed and recorded from the output of a fluoroscope.  

The slight departure in the nuclear magnetic resonance spectrum of an element—hydrogen, say, when it is a constituent in a complex biomolecule—from the spectrum for a sample containing that element in pure form. Detecting this chemical shift is an important step in identifying molecular structure.  

A plot of the amount of blackening that a film or film-screen combination will achieve as a function of differing levels of radiation exposure. A graph represented by plotting the logarithm of exposure on the horizontal scale and the logarithmic measurement of optical density on the vertical scale.  

Since many radioactive isotopes are formed by adding a neutron to a stable isotope of the same element by bombarding a sample in a nuclear reactor, it is impossible to chemically separate the active isotope from the stable one. If it could be done, the active substance would be said to be carrier-free.  

The unit of luminous intensity. One of the base units in the S.I. system. The SI unit of luminous intensity, equal to the intensity in a horizontal direction of a surface of 1/600,000 square meter of a black body at a temperature of 2040 kelvins and a pressure of 101,325 pascals.  

Cancer involving the vulva (the external female genitals). Most cases (nearly 90 percent) are squamous cell carcinomas (a type of skin cancer); about 5 percent are melanoma (another type of skin cancer). The most common symptom of cancer of the vulva is persistent itching. Lumps may appear on the labia, the clitoris, or the perineum…

Most uterine cancers are tumors involving cells in the uterine lining (endometrium). Symptoms include abnormal bleeding, spotting, or discharge from the vagina. Cancer of the uterus is rare before age 40 and most often occurs in women between ages 60 and 75. A malignant neoplasm of the uterus, suggested by size, intermittent bleeding, purulent discharge,…

Also called testicular cancer; a malignant tumor that begins in the testicle, one of the two organs located in the protective pouch between the legs of a boy or man. The testicles produce sperm cells and secrete the principal hormones (including testosterone) that control male sexuality and physical characteristics, such as facial hair, a deeper…

Caring for the teeth involves brushing the teeth at least twice daily with a fluoride toothpaste, and dental flossing at least once a day using the technique recommended by a dentist or dental hygienist.  

Cancer that originates in the rectum, the lower part of the large intestine just below the colon. Colon and rectal cancers are often jointly called colorectal cancer. Most cancers of the large intestine grow slowly; therefore, colorectal cancer can often be cured with early detection and treatment. A cancerous growth in the rectum, the final…