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 […]

A nonsteroidal anti-inflammatory drug (NSAID) that is commonly used to treat pain, swelling, and fever. Common brand names of ibuprofen include Advil, Motrin, and Nuprin.

Fear of demons: An abnormal and persistent fear of evil supernatural beings in persons who believe such beings exist and roam freely to cause harm. Those who suffer from this phobia realize their fear is excessive or irrational. Nevertheless, they become unduly anxious when discussing demons, when venturing alone into woods or a dark house, […]

unilateral and bilateral. Unilateral acoustic neurinomas affect only one ear. They account for approximately 8 percent of all tumors inside the skull. Symptoms may develop at any age but usually occur between the ages of 30 and 60 years. Bilateral acoustic neurinomas, which affect both ears, are hereditary. Inherited from one’s parents, this tumor results […]

Avoid eating raw or undercooked pork and other meats. Don’t eat meat of pigs that are likely to be infected with the tapeworm. Wash hands with soap and water after using the toilet and before handling food, especially when traveling in developing countries. Wash and peel all raw vegetables and fruits before eating. Avoid food […]

An infection of the upper part of the respiratory system which is above the lungs. An upper respiratory infection can be due to any number of viral or bacterial infections. These infections may affect the throat (pharyngitis), nasopharynx (nasopharyngitis), sinuses (sinusitis), larynx (laryngitis), trachea (tracheitis) or bronchi (bronchitis). Upper respiratory infection is commonly abbreviated URI.