birth The process of delivering a fetus from the uterus. Normally, the fetus is expelled through the cervix and birth canal with the assistance of rhythmic muscle contractions. Birth may instead be a surgical procedure: a Caesarean section. See also caesarean section.
bipolar disorder A disorder, formerly called manic-depressive illness, in which the patient cycles through uncontrollable mood states. Less prevalent than simple clinical depression, bipolar disorders involve cycles of depression, hypomania (elevated mood), mania (extremely elevated mood), and in some cases psychosis. Sometimes the mood switches are dramatic and rapid, but most often they are gradual….
bioterrorism Terrorism using biologic agents that are harmful to humans. Biological diseases and the agents that might be used for terrorism have been listed by the US Centers for Disease Control and Prevention (CDC). These agents include viruses, bacteria, rickettsiae (microorganisms that have traits common to both bacterial and viruses), fungi, and biological toxins. The…
biotechnology The fusion of biology and technology, the application of biological techniques to product research and development. In particular, biotechnology involves the use by industry of recombinant DNA, cell fusion, and new bioprocessing techniques to produce large molecules useful in treating and preventing disease. Slang biotech.
biopsy, stereotactic needle A procedure in which the spot to be biopsied is located threedimensionally, the information is entered into a computer, and then the computer calculates the information and positions a needle to remove the biopsy sample. Stereotactic needle biopsy can be done in a properly equipped physician’s office, and it carries a minimal…
biopsy, sentinel-lymph-node Examination of the first lymph node that receives lymphatic drainage from a tumor to learn whether that node has tumor cells in it. The sentinel node’s identity is determined by injecting around the tumor a tracer substance that travels through the lymphatic system to the first draining node, thereby identifying it. If the…
biopsy, punch See punch biopsy.
biopsy, needle A procedure in which a small amount of tissue is taken for examination by using a hollow needle. See also biopsy; biopsy, stereotactic needle.
biopsy, incisional A surgical procedure in which only a portion of an abnormal area is removed for diagnostic examination under a microscope. An incisional biopsy is used when the abnormal area is too large for excisional biopsy or when excision would destroy important tissue or pose a cosmetic problem. See also biopsy, excisional.
biopsy, excisional A surgical procedure in which an entire abnormal area is removed for diagnostic examination under a microscope.
biopsy, endometrial A procedure for sampling the lining of the uterus (the endometrium). Endometrial biopsy is usually done to detect the cause of abnormal uterine bleeding, but it may be used to determine the cause of infertility, test for uterine infections, and even monitor responses to certain medications. The procedure can be done in a…
biopsy The removal of a sample of tissue for examination under a microscope to check for cancer cells or other abnormalities.