(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.
Undifferentiated
Definition:
(a.) Not differentiated; specifically (Biol.), homogenous, or nearly so; -- said especially of young or embryonic tissues which have not yet undergone differentiation (see Differentiation, 3), that is, which show no visible separation into their different structural parts.
Example Sentences:
(1) The subcellular distribution of sialyltransferase and its product of action, sialic acid, was investigated in the undifferentiated cells of the rat intestinal crypts and compared with the pattern observed in the differentiated cells present in the surface epithelium.
(2) Macrophages, undifferentiated fibroblasts and highly differentiated fibroblasts can be observed.
(3) Carcinomas exhibiting atypical behavior are characteristically undifferentiated and aggressive.
(4) Because of its potential significance in human lung cancer, we investigated the expression of the CYP1A1 structural gene in 24 established human lung cancer cell lines including 15 non-small cell (eight adenocarcinomas, three large cell undifferentiated carcinomas, two bronchioloalveolar cell carcinomas, and two squamous cell carcinomas) and nine small cell lung carcinomas.
(5) All 51 undifferentiated NPCs contained significant numbers of EBV-genome copies per cell.
(6) Unfortunately, it does not contain a population of undifferentiated stem cells to supply the necessary healthy neurons.
(7) The anterior division can be further parcellated into dorsal, lateral, and ventral areas, and each of these areas, along with the posterior division, can be thought of as containing more-or-less discrete nuclei embedded within a relatively undifferentiated region.
(8) In undifferentiated glioblastomas, the reverse situation was observed, no SS receptors were found (0 of 14) but EGF receptors were present in a majority of tumors (8 of 14).
(9) The human epidermal growth factor receptor (hEGF-R) was introduced into murine P19 embryonal carcinoma (EC) cells, which do not express endogenous EGF-R. Undifferentiated stable P19 EC transfectants containing multiple copies of the hEGF-R complementary DNA were isolated.
(10) However, the tip cells are slow to differentiate, and hence immature fruiting bodies contain a small population of undifferentiated tip cells.
(11) We report on a patient with AL, which showed a very rapid switch from the lymphoblastic phenotype exhibited at presentation to a myelomonoblastic one, appeared at first relapse, and lastly progressed to an undifferentiated leukemia in the terminal phase.
(12) The pathologic diagnosis was rhabdomyosarcoma in 75% of cases, yolk sac tumor in 13% of cases, malignant mesenchymoma in two cases, clear cell carcinoma in two cases, and undifferentiated sarcoma in one case.
(13) Of 28 rats given 0.15 mg of 1,6-DNP, 21 (75%) developed squamous cell carcinomas, 2 (7%) developed undifferentiated carcinomas, and 2 (7%) had squamous metaplasias in the lung by 72 weeks.
(14) A case of large cell undifferentiated adenocarcinoma of the lung was complicated by an aggressive clinical course and documented placental metastases.
(15) In anurans, the oculomotor neurons receive a variety of visual, somatic, and vestibular afferents and appear relatively undifferentiated, whereas the nInt appears more developed.
(16) In previous specimens, solid undifferentiated carcinoma was absent or was a minor pattern.
(17) There was a nonsignificant trend toward higher MHPG levels in paranoid schizophrenic patients in comparison with patients who had undifferentiated schizophrenia.
(18) The process from the first undifferentiated stage to the second predifferentiated stage with well-developed ER and Golgi apparatus requires both collagen gels and hormones.
(19) The possibility of preventing or influencing the course of these diseases by vaccination has been advocated for a number of years [Epstein, 1976], especially in the case of undifferentiated nasopharyngeal carcinoma, which is the most common tumour of men in southern China and is prevalent in other specific regions; it therefore represents a major world cancer problem [Shanmugaratnam, 1971].
(20) Ultrastructurally, the tumor cells were composed principally of undifferentiated mesenchymal cells, and contained prominent pools of glycogen in the cytoplasm.