Biopsy

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.) A biopsy may be done, for example, because of concern about cancer. The physical exam, imaging, endoscopy, and laboratory tests may indicate that something is abnormal, but a biopsy may be the only sure way to know whether the problem is, in fact, cancer. In a biopsy, the doctor removes a sample of tissue from the abnormal area or may remove the whole tumor. A specialist trained to examine such tissues is called a pathologist. A pathologist examines the tissue under a microscope. If cancer is present, the pathologist can usually tell what kind of cancer it is and may be able to judge whether the cells are likely to grow slowly or quickly.

Thyroid stimulating immunoglobulin (TSI)

Thyroid stimulating immunoglobulin (TSI): A form of immunoglobulin G (IgG) that can bind to thyrotropin (TSH) receptors on the thyroid gland. TSIs mimic the action of TSH, causing excess secretion of thyroxine and triiodothyronine. The TSI level is abnormally high in persons with hyperthyroidism due to Graves' disease.Common Misspellings: thyriod stimulating immunoglobulin (tsi), athyroid stimulating immunoglobulin (tsi), throid stimulating immunoglobulin (tsi)

Arterial blood gas (ABG)

Arterial blood gas (ABG): The sampling of the blood levels of oxygen and carbon dioxide within the arteries, as opposed to the levels of oxygen and carbon dioxide in venous blood. Typically the acidity, or pH, of the blood is measured simultaneously with the gas levels in ABG sampling. Common Misspellings: arterial blod gas (abg)

SPECT scan

SPECT scan: Single Photon Emission Computed Tomography, a nuclear medicine procedure in which a gamma camera rotates around the patient and takes pictures from many angles, which a computer then uses to form a tomographic (cross-sectional) image. The calculation process in SPECT is similar to that in CT (X-ray computed tomography) and in PET (positron emission computed tomography).

Desmoplasia

Desmoplasia: This term refers to the growth of fibrous or connective tissue. Some tumors elicit a desmoplastic reaction, the pervasive growth of dense fibrous tissue around the tumor. Scar tissue (adhesion) within the abdomen after abdominal surgery is another type of desmoplastic reaction. "Desmo-" comes from the Greek "desmos" meaning "a fetter or band" and "-plastic" is also borrowed from the Greek, from "plassein" meaning "to form" = to form a band or fetter.

D (drug caution code)

D (drug caution code): Abbreviation on a medication that indicates caution because the medication may cause drowsiness. While not a part of the historical heritage of ancient prescription abbreviations, drug caution codes provide very valuable warnings. If you see a caution code on a prescription, talk to your pharmacist about it before using the medicine. In the United States and some other countries, a system of stickers with pictographs is also used to warn of side effects such as drowsiness.

Zygote

Zygote: The cell formed by the union of a male sex cell (a sperm) and a female sex cell (an ovum). The zygote develops into the embryo following the instruction encoded in its genetic material, the DNA. The unification of a sperm and an ovum to form a zygote constitutes fertilization.