Category: Z

A cataract with opacity limited to certain layers of the lens.  

A type of health care benefit plan provided by employers who are self-insured and pay for the care as it is given. The ceiling under such a plan is typically “unlimited.” The Internal Revenue Service (IRS) has ruled that funds spent for a beneficiary (here an employee) under such a plan are taxable to the…

An old name for contagious disease, which was formerly thought to develop within the body following infection in a process similar to the fermentation and growth of yeast.  

The process of fermentation or digestion by an enzyme. The mechanism of fermentation initiated by an enzyme during digestion. The changes produced by an enzyme; the action of enzymes. Fermentation or digestion brought about by an enzyme.  

The second stage of the first prophase of meiosis, in which the homologous chromosomes form pairs (bivalents). The second stage of the prophase of the first meiotic division. During this stage, the homologous chromosomes pair side by side.  

An ion that bears a positive and a negative charge. Amino acids can yield zwitterions. A dipolar ion that contains positive and negative charges of equal strength. This ion is therefore not attracted to either an anode or cathode. In a neutral solution, amino acids function as zwitterions. An ion that bears both positive and…

An astringent applied in a lotion for the treatment of ulcers of the skin and mouth and to assist wound healing. It is also used in eye drops and, occasionally, as an emetic. An astringent agent used as a 0.25% solution for temporary relief of minor eye irritation.  

An antimigraine drug. Zolmitriptan (Zomig) is used to treat severe migraine headaches. Zolmitriptan cannot prevent migraine but can only ease a migraine headache that is already occurring. Zolmitriptan relieves symptoms that are associated with migraine, including nausea, vomiting, and sensitivity to light and sound. It is thought to work by narrowing blood vessels in the…

An antiasthma drug. Zileuton (Zyflo) is a type of antiasthma drug called a leukotriene inhibitor, used by people with mild to moderate asthma to decrease symptoms and the number of acute asthma attacks. Zileuton cannot relieve an asthma attack that has already started. It works by inhibiting leukotrienes, substances in the body that are associated…

An antiviral drug. Zanamivir (Relenza) is used to treat influenza virus A and B (flu) in people who have had symptoms such as weakness, headache, fever, cough, and sore throat for less than 2 days. Zanamivir cannot prevent flu, nor can it keep a person from spreading the virus to others, but it seems to…