Blastema


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blastema

[bla′stēma]
(embryology)
A mass of undifferentiated protoplasm capable of growth and differentiation.

Blastema

 

in the study of regeneration, the accumulation of homogeneous, nonspecialized cells on the surface of a wound after amputation of an organ. Tissues of the organ that is being restored are formed from blastemas in the course of regeneration.

In embryology: (1) a group of cells from which a new individual develops by asexual reproduction in some multicellular animals (Coelenterata, worms, Ascidia, and others); (2) the surface layer of cytoplasm in the cen-trolecithal ova of many arthropods. By means of fine outgrowths the blastema is connected to the cytoplasm, which surrounds the nucleus situated in the center of the ovum.

References in periodicals archive ?
(e) Wilm's tumor, with regressive changes, of intermediate risk with only small areas of blastema (Hematein-Eosin-Safran, x400).
A wandering ureteral bud may cross the midline to the contralateral side and diffuse with the contralateral metanephric blastema, rather than the same side blastema, resulting in the formation of a crossed ectopic kidney.
(51) From the seventeenth to nineteenth centuries, the lymph and blastema theories dominated the oncology landscape, contending that cancer was formed by the abnormal movement of fluid throughout the body and by small blastemas between pockets of tissue.
MRKH syndrome has been attributed to an initial affection of the intermediate mesoderm, consequently leading to an alteration of the blastema of the cervicothoracic somites and pronephric ducts (4,12).
Salamanders, axolotls, and zebrafish respond to heart injury inducing a blastema tissue, as part of an epimorphic regeneration [77].
Blastema cells then accumulate underneath the healed epidermis, which forms a thickened structure at its apex, called the apical epithelial cap (AEC) [21, 22].
The inadequate stimulation of metanephrogenic blastema by the ureteric bud results in renal maldevelopment.
A German pathologist Johannes Muller first time demonstrated that cancer cells were originated from a bud called Blastema instead of normal cells (Kardinal and Yarbro, 1979).
Unlike urodele limb regeneration, antler regeneration does not involve cell de-differentiation and the formation of a blastema from the de-differentiated cells; rather, antler regeneration appears to a stem-cell-based process that requires the periodic activation of periosteal stem cells of the distal pedicle, which are presumably derived from the neural-crest (Kierdorf et al., 2007).
Radial water canals and ambulacral plates arise from the blastema. Consequently, growth occurs from the proximal to the distal region.
It's thought to come from very specialised cells in the embryo known as metanephric blastema. These cells are involved in the development of the child's kidneys while they're in the womb.