maturation arrest


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arrest

 [ah-rest´]
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.

mat·u·ra·tion ar·rest

cessation of complete differentiation of cells at an immature stage; in spermatogenic maturation arrest, the seminiferous tubules contain spermatocytes, but no sperms develop.

maturation arrest

Haematology
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.

arrest

sudden cessation or stoppage.

cardiac arrest
sudden and often unexpected stoppage of effective heart action. Either the periodic impulses which trigger the coordinated heart muscle contractions cease or ventricular fibrillation or flutter occurs in which the individual muscle fibers have a rapid irregular twitching.
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.
sinoatrial arrest
a disturbance in cardiac conduction in which the sinoatrial node intermittently fails to generate an impulse. There are no P waves or PQRS-T complexes for at least twice the normal R-R interval. If the pauses are long enough, junctional or ventricular escape complexes may occur. Occurs most commonly in brachycephalic dogs, causing only minor clinical signs.

maturation

1. the stage or process of attaining maximal development. In biology, a process of cell division during which the number of chromosomes in the germ cell is reduced to one-half the number characteristic of the species.
2. the formation of pus.

maturation arrest
an interruption in the progressive development of erythrocytes, characterized by a bone marrow dominated by macrocytes and megaloblasts. Seen in anemias caused by deficiency of folic acid and vitamin B12.
References in periodicals archive ?
In our study, deletion of only AZFb region resulted in maturation arrest and men having AZFa or AZFb+c deletions had a much more severe phenotype like SCO I and SCO II.
Evaluation for maturation arrest requires evaluating whether spermatogenesis proceeds to full spermatid differentiation across the tubules.
Maturation arrest of stem cell differentiation is a common pathway for the cellular origin of teratocarcinomas and epithelial carcinomas.
A differential count was performed for each bone marrow specimen to determine the degree of maturation arrest, as assessed morphologically, in patients with MDS compared with controls.