maturation arrest(redirected from maturational arrest)
sudden cessation or stoppage.
cardiac arrest see cardiac arrest.
epiphyseal arrest premature arrest of the longitudinal growth of bone due to fusion of the epiphysis and diaphysis.
maturation arrest interruption of the process of development, as of blood cells, before the final stage is reached.
cessation of complete differentiation of cells at an immature stage; in spermatogenic maturation arrest, the seminiferous tubules contain spermatocytes, but no sperms develop.
The presence of relatively mature cytoplasm and an immature nucleus, seen in patients with megaloblastic anaemia due to a deficiency of vitamin B12 and/or folic acid, and in acute leukaemias.
Maturation arrest affects all cells, is most prominent in the bone marrow, and is characterised by enlarged cells with delicate, open chromatin and prominent parachromatin. This nuclear:cytoplasmic asynchrony is due to decreased DNA synthesis and a block in mitosis, attributed to the slowing of cobalamin-dependent pathway of methionine synthesis; this in turn sequesters folate as N5-methyl FH4, which cannot be used by thymidylate synthetase to generate dTMP from dUMP.
mat·u·ra·tion ar·rest(mach'ūr-ā'shŭn ă-rest')
Cessation of complete differentiation of cells at an immature stage; in spermatogenic maturation arrest, the seminiferous tubules contain spermatocytes, but no sperms develop.