Macr-/macro: From 1 Different Sources
Pre?x denoting large-sized cell – for example, a MACROPHAGE is a large PHAGOCYTE.
This is a mature form of what is released from the marrow as a monocyte. A macrophage lives long, can digest much detritus, and is able to wear particles of odd food on its outer membrane. This allows T-cell and B-cell Iymphocytes to taste the particle (an epitope) and form an antibody response. Further, these macrophages, traveling as monocytes, will take up permanent residence in many tissues, providing them with immunity. They line the spleen, form the cleansing Kupffer cells in the liver, make up the “dust cells” that protect the lungs, protect the synovial fluids of the joints, and form the microglial cells that provide protection to the brain and nerve tissues. On and on, the macrophages clean up messes and acting as the intermediates between innate and acquired immunity.... macrophage
An abnormally large TONGUE.... macroglossia
Macrocyte is an unusually large red blood cell (see ERYTHROCYTES) especially characteristic of the blood in PERNICIOUS ANAEMIA.... macrocyte
This condition is particularly associated with PERNICIOUS ANAEMIA but can also be caused by a number of other things, such as alcohol, pregnancy, myxoedema (see THYROID GLAND, DISEASES OF – Hypothyroidism) and MYELOMATOSIS, and also by vitamin B12 de?ciency: this occurs sometimes in vegans (see VEGANISM) as well as in patients with CROHN’S DISEASE.... macrocytosis
A group of ANTIBIOTICS. The original macrolide, ERYTHROMYCIN, was discovered in the early 1950s and used successfully as an alternative to PENICILLIN. The name ‘macrolide’ derives from the molecular structure of this group, three others of which are clarithromycin, azithromycin and spiramycin. Macrolides check PROTEIN synthesis in BACTERIA and the latest ones are, like erythromycin, active against several bacterial species including gram-positive COCCI and rods. In addition, they act against Haemophilus in?uenzae. Clarithromycin is potent against Helicobacter pylori; azithromycin is e?ective against infections caused by Legionella spp. (see LEGIONNAIRE’S DISEASE) and GONOCOCCI. Spiramycin is a restricted-use macrolide prescribed for pregnant patients with TOXOPLASMOSIS.... macrolides
A dietary system in which foods with a balance of yin and yang are eaten. Foods are classified as yin or yang depending on factors such as their colour, texture, and taste.... macrobiotics
(macro-) combining form denoting large size. Example: macrencephaly (abnormally enlarged brain).... macr
(megalocephaly) n. abnormal largeness of the head in relation to the rest of the body. Compare microcephaly.... macrocephaly
n. hypertrophy of the lips: a congenital condition in which the lips are abnormally large. Compare microcheilia.... macrocheilia
n. abnormally large size of one or more of the fingers or toes.... macrodactyly
(megadontia, megalodontia) n. a condition in which the teeth are unusually large. Macrodontia may be true generalized (all the teeth are larger than normal), relative generalized (all teeth appear larger than normal, usually because the jaw is abnormally small), or localized (affecting a single tooth or teeth in one part of the mouth).... macrodontia
n. the nonmotile female sex cell of the malarial parasite (Plasmodium) and other protozoans. The macrogamete is similar to the ovum of animals and larger than the male sex cell (see microgamete).... macrogamete
n. a cell that undergoes meiosis to form mature female sex cells (macrogametes) of the malarial parasite (see Plasmodium). Macrogametocytes are found in human blood but must be ingested by a mosquito before developing into macrogametes.... macrogametocyte
n. excessive bodily growth with marked enlargement of the genitalia. Macrogenitosoma praecox is a variant occurring in early childhood.... macrogenitosoma
n. one of the two basic classes of *glia (the non-nervous cells of the central nervous system), divided into *astrocytes and *oligodendrocytes. Compare microglia.... macroglia
n. 1. (immunoglobulin M, IgM) a protein of the globulin series that is present in the blood and functions as an antibody, forming an effective first-line defence against bacteria in the bloodstream. See also immunoglobulin. 2. an abnormal form of IgM (see paraprotein) produced by *lymphoma cells or in other plasma-cell disorders, such as multiple *myeloma.... macroglobulin
n. the presence in the blood of excessive amounts of *macroglobulin (IgM), produced by a malignant proliferation of the lymphocytes in certain *lymphomas. See Waldenstrom’s macroglobulinaemia.... macroglobulinaemia
n. a condition in which one or both jaws are abnormally large. It can be associated with pituitary *gigantism, tumours, and other disorders. It can often be corrected with surgery.... macrognathia
n. abnormally large size of the arms or legs. Compare micromelia.... macromelia
n. an abnormal form of any of the cells (*normoblasts) that form a series of precursors of red blood cells. Macronormoblasts are unusually large but have normal nuclei (compare megaloblast); they are seen in certain anaemias in which red cell production is impaired.... macronormoblast
n. a physiologically inactive form of the hormone prolactin, bound to immunoglobulin G to create a much bigger molecule. It is found in a small proportion of people but is important because some laboratory assays will detect it as prolactin, leading to a falsely elevated prolactin level in the blood and a misdiagnosis of hyperprolactinaemia (see prolactin).... macroprolactin
adj. visible to the naked eye. Compare microscopic.... macroscopic
n. abnormally large size. In fetal macrosomia the baby is large for its gestational age. This condition is associated with poorly controlled maternal diabetes, the increased size being due to excessive production of fetal insulin and thence to increased deposition of glycogen in the fetus, and maternal obesity.... macrosomia
n. a congenital deformity of the external ear in which the *pinna is larger than normal.... macrotia
(lymphoplasmacytic lymphoma) a type of low-grade relatively slow-growing non-Hodgkin’s *lymphoma characterized by enlarged lymph nodes and high levels of abnormal IgM (*macroglobulin) in the blood (see macroglobulinaemia). [J. G. Waldenstrom (1906–96), Swedish physician]... waldenstrom’s macroglobulinaemia
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