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.

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 […]

‘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.

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 […]

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 […]

Condition characterized by abnormally elevated levels of uric acid in the blood, recurring attacks of joint inflammation (arthritis), deposits of hard lumps of uric acid in and around the joints, and decreased kidney function and kidney stones. Uric acid is a breakdown product of purines, that are part of many foods we eat. The tendency […]

Mutation of this gene is responsible for an autosomal recessive form of primary microcephaly with no other malformations. Microcephalin 1 (MCPH1) is expressed in fetal brain in the developing forebrain and the walls of the lateral ventricles. Cells in this region divide to produce neurons that migrate to form the cerebral cortex. The MCPH1 gene […]

The branch of medicine concerned with the diagnosis, treatment and prevention of disease in older people and the problems specific to aging. Also called geriatrics. From the Greek “geron” meaning “old man” + “iatreia” meaning “the treatment of disease.”.

Our Symptoms article on Burning Urination provides a comprehensive look at the possible causes and treatments of Burning Urination. Dysuria: Pain during urination, or difficulty urinating. Dysuria is usually caused by inflammation of the urethra, frequently as a result of infection.

Cyto-: Prefix denoting a cell. “Cyto-” is derived from the Greek “kytos” meaning “hollow, as a cell or container.” From the same root come the combining form “-cyto-” and the suffix “-cyte” which similarly denote a cell. Cyto-, -cyto- and -cyte enter into many words and terms used in medicine, including adipocyte, agranulocytosis, cytogenetics, cytokine, […]