• Z chromosome

    A sex chromosome in certain animals, such as chickens, turkeys, and moths. In humans, males are XY and females XX, but in animals with a Z chromosome, males are ZZ and females are WZ.

  • ZAP-70

    Zeta-chain-associated protein kinase 70. A member of the protein tyrosine kinase family, ZAP-70 is normally expressed in T cells and natural killer cells and has a critical role in the initiation of T-cell signaling. ZAP-70 is expressed in T cells and tumors of T-cell lineage. A high level of ZAP-70 expression appears restricted to T-cell […]

  • Zebra

    ‘When you hear hoof beats, think of horses, not zebras.’ For example, when someone develops a mild transient cough, a virus infection is the most logical and likely cause, and tuberculosis is a zebra.

  • Zygotic lethal gene

    A gene that is lethal (fatal) for the zygote, the cell formed by the union of a sperm (male sex cell) and an ovum (female sex cell). The zygote would normally develop into an embryo, as instructed by the genetic material within the unified cell. However, a zygotic lethal gene scotches prenatal development at its […]

  • Zygote intrafallopian transfer (ZIFT)

    A technique in which a woman’s egg is fertilized outside the body, then implanted in one of her fallopian tubes. This technique is one of the methods used to overcome infertility, the inability of couples to produce offspring on their own. First, the egg and the male sperm needed to fertilize it are harvested. Then […]

  • OB

    Abbreviation for obstetrician or for obstetrics, the art and science of managing pregnancy, labor and the puerperium, the time immediately after delivery.

  • Salicylic acid

    A substance obtained from plants (white willow back and wintergreen leaves) and also synthesized which is versatile and possesses bacteriostatic, fungicidal, and keratolytic actions. Salicylic acid is used as a food preservative and as an antiseptic in toothpaste. It is a peeling agent in ointments, creams, gels, and shampoos applied to reduce the scaling of […]

  • Immunology

    The study of all aspects of the immune system, including its structure and function, disorders of the immune system, blood banking, immunization, and organ transplantation.

  • Miscarriage

    Inadvertent loss of a pregnancy before the fetus is viable. A considerable proportion of pregnancies end in miscarriage. Also known as spontaneous abortion.

  • Sore

    1. (adjective) A popular term for painful, such as a sore throat. 2. (noun) A nondescript term for nearly any lesion of the skin or mucous membranes. He has a number of sores in his mouth. The word sore traces its origin to the Anglo-Saxon term sar which meant distressing, grievous, painful.