malaria, falciparum The most dangerous type of malaria, which is caused by the parasite Plasmodium falciparum. Falciparum malaria is associated with high levels of parasites in the blood and has the highest death rate and rate of complications of all types of malaria. Red blood cells that are infected with the parasite tend to sludge…
male 1 Of the sex that produces sperm cells rather than eggs. 2 Having the physical appearance, by chromosome constitution or by gender identification, of the sex that produces sperm cells rather than eggs.
male chromosome complement The whole set of chromosomes for a human male. The large majority of males have a 46,XY chromosome complement: 46 chromosomes, including 1 X and 1 Y chromosome. A minority of males have other chromosome constitutions, such as 47,XXY (47 chromosomes, including 2 X chromosomes and 1 Y chromosome) or 47,XYY (47…
macroangiopathy A disease of the large blood vessels in which fat and blood clots build up and stick to the vessel walls, blocking the flow of blood. Types of macroangiopathy include coronary artery disease (macroangiopathy in the heart), cerebrovascular disease (macroangiopathy in the brain), and peripheral vascular disease (macroangiopathy that affects, for example, vessels in…
macrobiota The living organisms of a region that are large enough to be seen with the naked eye.
macrobiotic Referring to the macrobiota, a region’s living organisms that are large enough to be seen with the naked eye.
macrobiotic diet A diet that incorporates Ayurvedic principles of food combining, is based mainly on brown rice and vegetables, and claims to lengthen life. The macrobiotic diet is strictly not recommended for pregnant women or children and may not provide sufficient protein and nutrients for others.
macrocephaly An abnormally large head. The opposite of macrocephaly is microcephaly. Macrocephaly can be a normal variant or be a sign of pressure within the growing head during childhood, such as from hydrocephalus.
macroglobulinemia A condition in which the blood contains high levels of large proteins and is too thick to flow through small blood vessels. The large protein is an antibody called macroglobulin or IgM. One type of macroglobulinemia is Waldenström macroglobulinemia, a type of cancer.
macroglossia An abnormally large tongue. Macroglossia is sometimes said to be associated with Down syndrome, but in that disorder the tongue is actually large only in relationship to a smaller-thannormal mouth cavity.
macrognathia An abnormally large jaw. Macrognathia can be associated with pituitary gigantism, tumors, and other disorders. Macrognathia can often be corrected with surgery. Also known as prognathic mandible.
macrolide antibiotic One of a family of antibiotics produced by Streptomyces bacteria. Examples of the macrolide antibiotics include erythromycin and azithromycin. See also erythromycin.