(n.) The process of generation by development of blastema, or fission of cells, in which the new formation is in all respect like the individual from which it proceeds.
Example Sentences:
Blastema
Definition:
(n.) The structureless, protoplasmic tissue of the embryo; the primitive basis of an organ yet unformed, from which it grows.
Example Sentences:
(1) They are capable of synthesis and accumulation of glycogen and responsible for its transfer to sites of more intense metabolism (growth, bud, blastema).
(2) Blastemas implanted with 2 dorsal root ganglia and simultaneously denervated 14 days after amputation exhibited control levels of cell cycle activity 6 days later, as measured by 3H-thymidine pulse labeling.
(3) A search for specific proteins involved in newt limb regeneration, using monoclonal antibodies against forelimb blastemas, led to the detection of an antigen in the regenerate epithelium.
(4) Between different tumours, heterogeneity in the degree of epithelial differentiation in the blastema was found.
(5) After amputation, limbs of both early and late stages form a regenerative blastema and support lens formation from the outer cornea.
(6) More difficult are clear therapeutic recommendations for the very rare forms of endocrinically active genital tumors which stem from sex cords or which are composed of different components of the complex ovarian blastema.
(7) By 15 days, a dense accumulation of blastema cells is present beneath the apical cap, and these cells are preferentially oriented in a circumferential direction.
(8) Not all cells of the adult newt blastema are randomly distributed and actively progressing through the cell cycle.
(9) Thus, it appears that denervation of medium-bud-stage limb blastemas promotes the lengthening of G1 and premature exiting of cells from the cycle into the G0-1 phase.
(10) Computer-assisted morphometric analysis showed only minor differences between proximal tubular cells from 18-day embryos and tubular cells from 7-day cultures of blastema taken from 11-day embryos.
(11) In the absence of skin, epidermal wound healing failed to occur and blastemas could not develop.
(12) At the contact between the ureter and the mesonephretic blastema, the cells of the primary ureter have special characteristics: existence of an abundant "coat", numerous "villous processes" and a dense network of fibres of collagen.
(13) Serial angiograms and tissue biopsies documented the transition from nodular renal blastema to Wilms' tumor.
(14) After amputation, NvKII mRNA is expressed both in proximal and distal blastemas, although at higher levels distally, indicating that this keratin is regeneration associated.
(15) Since others have shown that denervation at the time of amputation blocks subsequent mitosis in internal stump tissues yet allows normal levels of DNA synthesis for eight days, we conclude that X-irradiation and denervation prevent cell division in potential blastema cells by different mechanisms.
(16) In a study of 71 female foetuses, gonadal blastema was observed at 1.5 cm crown rump length (CRL).
(17) Furthermore, staining with three fucose-binding lectins revealed that the linkage between terminal alpha-fucose residues to the constituent oligosaccharide chains varied between epithelial cells, blastema and stroma.
(18) However, in differentiation phase blastemas, laminin immunoreactivity was concentrated in specific locations.
(19) The fasciculata cells are the direct continuation of the subcapsular blastema.
(20) These results indicate that the limb tissues of the early stage limbs contain non-neural inductive factors at a low level and that after limb amputation and blastema formation the level of these factors becomes high enough to promote lens formation from implanted cornea, even after denervation.