(n.) Formation and separation of laminae or layers; one of the methods by which the various blastodermic layers of the ovum are differentiated.
Example Sentences:
(1) Dissecting aneurysms--which should be called incomplete internal aortic disease with delamination of the media--remains a fearsome disease in subjects over 50, despite advances in surgery.
(2) Pathologic examination revealed a damaged luminal surface in 22 grafts, deep folds in 8 grafts and delamination of the graft wall in 16 cases.
(3) Orthopedic surgeons should be aware of early delamination and surface failure in heat-pressed inserts.
(4) Water absorption and subsequent delamination made the plate flexible.
(5) These insights give us several ideas about possible therapeutic interventions: corticosteroids or other drugs might be used to blunt granulocyte responsiveness; iron chelation might be used to limit the production of toxic hydroxyl radical; competitive inhibition of oxidant damage might be possible using such simple compounds as methionine; protease inhibitors might blunt endothelial cell delamination.
(6) Meso1 is a molecule of 380 kDa that is first detected at the time of primary mesenchyme cell delamination from the wall of the blastula.
(7) No delamination was found for either system after vigorous washing with water.
(8) Localization of the transcript and protein in embryos has shown that the gene is predominantly expressed in a restricted set of tissues: the developing tracheal system and the delaminating midline glial and neural cells.
(9) Delamination, consisting of complete breakup of material in flakes and particles, appeared to be initiated by intergranular material defects and propagated by the excessive subsurface stresses beneath the contact zone.
(10) In embryos lacking any one of five genes, the restriction of ac expression to single cells does not occur; instead, all cells of each cluster continue to express ac, enlarge, delaminate and become neuroblasts.
(11) Results indicated that these dentinal bonding agents actually bonded to the smear layer, and samples demonstrated delamination of the smear layer from underlying dentin following thermocycling.
(12) The polyethylene of PCA tibial components showed serious delamination after only short durations, as a result of heat pressing.
(13) As the neural folds elevate, the NE and EE delaminate progressively beginning at the basal surface of the lateral extremes of the neural plate.
(14) The photophores differentiate as an outgrowth of the basal cell layer of the epidermis, from which they delaminate into the dermis.
(15) The polyethylene of the tibial components showed excessive delamination.
(16) Gross morphologic examination, light microscopy, and scanning electron microscopy demonstrated that the umbilical vein grafts appeared to be fragile and easily delaminated.
(17) The mitotic recombination experiment revealed that Notch product is required by epidermal cells subsequent to neuroblast delamination.
(18) At somitic levels, where the convergence is not important, delamination involves the progressive formation of a half-moon-shaped cavity.
(19) Abrasion from cement or bone and delamination wear were particularly pronounced in the knee.
(20) This ultimately resulted in disruption of the lamina, dispersal of the basal layer of the epithelium, and release of the crest precursors in the delaminate gap.
Gastrula
Definition:
(n.) An embryonic form having its origin in the invagination or pushing in of the wall of the planula or blastula (the blastosphere) on one side, thus giving rise to a double-walled sac, with one opening or mouth (the blastopore) which leads into the cavity (the archenteron) lined by the inner wall (the hypoblast). See Illust. under Invagination. In a more general sense, an ideal stage in embryonic development. See Gastraea.
(a.) Of or pertaining to a gastrula.
Example Sentences:
(1) Results obtained from cumulative labeling and pulse-labeling and chase experiments with cells from late gastrulae, yolk plug-stage embryos, and neurulae showed that the 30S RNA is an intermediate in rRNA processing and is derived from 40S pre-rRNA and processed to 28S rRNA.
(2) Cells falling off from ectoderm were observed in normally developing gastrulae of the newt, Cynops pyrrhogaster, in light microscopic examination.
(3) Among such genes, particular interest is focused on three genes encoding putative transcription factors that are expressed specifically in the Spemann organizer region of the gastrula.
(4) Their synthesis is first detectable in stage IV oocytes and continues throughout early embryogenesis until the late gastrula.
(5) The tandemly repeated genes were expressed at a higher rate in blastula than in gastrula stage relative to the single-copy gene, when the two genes were injected into sea urchin zygotes.
(6) RA was applied for one hour at concentrations ranging from 10(-9) to 10(-6) M to embryos at 50% epiboly, the midgastrula stage, and at 10(-7) M to embryos at early and late gastrula stages.
(7) In gastrulae, spectrin accumulates near the embryo surface, especially at the forming amnioproctodeal invagination and cephalic furrow.
(8) The dynamics of protein synthesis in the loach embryos has been studied by means of autoradiography at the stages of cleavage, blastula and gastrula.
(9) GAD activity was undetectable at the early gastrula stage (stage 8a) and was slightly measurable at the early neurula stage (stage 14- onset of the culture).
(10) However, we established an enhanced level of [14C]acetate incorporation at the time of extensive gene activation during gastrulation as well as some quantitative differences in the pattern of acetylation during gastrula and organogenesis.
(11) RNase protection assays demonstrate that transcripts encoding alpha, gamma, and delta subunits are coordinately expressed at late gastrula and that the amount of each transcript increases in parallel with muscle-specific actin mRNA during the ensuing 12 h. After the onset of muscle activity the level of actin mRNA per somite remains relatively constant, whereas the level of alpha subunit and delta subunit transcripts decrease fourfold per somite and the level of gamma subunit transcript decreases greater than 50-fold per somite.
(12) When the supernatant proteins from eggs and gastrulae were subjected to size-exclusion HPLC the neural inducing activity was eluted in different size classes, suggesting a limited proteolysis of a precursor during early embryogenesis.
(13) Isolated neuroblasts from gastrula-stage Drosophila embryos divide and differentiate in vitro to produce clonally derived clusters of neurons.
(14) In both fish embryos, the COI and COII transcripts declined gradually after fertilization until late-blastula stage and then increased in early gastrula stage.
(15) Three of these clones are not represented in the maternal RNA population but are activated at the late gastrula stage; the other three increase from a maternal base.
(16) This led to an attempt to discover the molecular character of cell action by means of transfilter induction in early gastrula ectoderm of Xenopus laevis.
(17) We have demonstrated that a 'wave' of DNA synthesis occurs in the neurectoderm of Xenopus laevis gastrula.
(18) When Xenopus blastula or early gastrula ectoderm is disaggregated and cells are kept dispersed for up to 5 h prior to reaggregation, the resulting spheres will differentiate into large neural structures.
(19) Yolky tissue from the vegetal hemisphere of the gastrula or the archenteron floor of the neurula synthesized mainly polydisperse material of high molecular weight rather than discrete glycoproteins.
(20) The transgenome replicates intensively during the course of early development (until the blastula--early gastrula stages), but later the replication slows down which results in the elimination of the transgenome from the majority of embryos at more advanced stages.