• 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 […]

  • MPO deficiency

    Myeloperoxidase deficiency.

  • Syndrome, cavernous sinus

    A cavernous sinus thrombosis is a blood clot within the cavernous sinus, a large channel of venous blood in a cavity bordered by the sphenoid bone and the temporal bone of the skull. The cavernous sinus is an important structure because of its location and its contents which include the third cranial (oculomotor) nerve, the […]

  • Spinocerebellar

    Pertaining to the spinal cord and the cerebellum, as in spinocerebellar ataxia (ataxia with cerebellar malfunction).

  • Thallium

    A metallic element having the symbol Tl and the atomic number 81 and an atomic weight of about 204. Approximately 70% of thallium production is used in electronics with the remaining used in pharmaceuticals, optics, infrared detectors, and nuclear medicine. Thallium was historically used as rat poison and insecticides, however due to its nonselective toxicity, […]

  • Chocolate

    Chocolate: A food or flavoring made from the seeds of the cacao or chocolate tree. Chocolate (especially dark chocolate) is rich in flavonoids, compounds that act as antioxidants. Flavonoids may also lower blood pressure and improve blood flow, by regulating the synthesis of nitric oxide, which dilates blood vessels. Flavonoids, like aspirin, help keep platelets […]