(n.) An elastic cartilagelike rod which is developed beneath the medullary groove in the vertebrate embryo, and constitutes the primitive axial skeleton around which the centra of the vertebrae and the posterior part of the base of the skull are developed; the chorda dorsalis. See Illust. of Ectoderm.
Example Sentences:
(1) The histochemical study of the LDH in the Trout embryo during the early organogenesis shows a specific localization in notochord cells, in mesodermic cells of the terminal knob and in some prosencephalic neuroblasts.
(2) The notochord, which is composed of a stack of flat cells surrounded by a connective tissue sheath, elongates dramatically and begins straightening between stages 21 and 25.
(3) Autoradiographic studies show that tritiated proline is taken up by notochordal cells and secreted to the extracellular space where label is associated with basal lamina, microfibrils and ground substance.
(4) Metabolic events in somites related to hyaluronic acid are not influenced by the notochord.
(5) The establishment of myeloschisis was followed by local separation of the notochord from an open area of neural tube, but not by overgrowth of neural tissue.
(6) By 7 days, notochordal uptake is markedly diminished, and no uptake of isotope occurs from 8 days onward.
(7) It first forms on the lateral portion of the neuroepithelium of the neural folds and then extends ventrally into the region adjacent to the notochord; (ii) BL becomes continuous beneath the epidermal ectoderm (EE) that overlies the NC cell region only during the terminal stages of NC cell emigration; (iii) BL does not form over the dorsal portion of the neural tube until NC emigration is terminated; and (iv) the morphology of the BL changes as development proceeds.
(8) Although they are presumed to arise from congenital notochordal remnants, it is rare for these tumors to present in childhood.
(9) Six chordomas, ten fetal notochords and eight adult notochords were stained for keratin, vimentin, GFAP, desmin, CEA, EMA and s-100 protein.
(10) A "diffuse pattern" that was seen in the histological appearance of 4 cases of the chordoma, including 2 cases with metastases, was not observed in the notochord and was considered to indicate the malignant nature of such chordoma.
(11) The results lead to the assumption that the early embryos already possess cholinergic receptors, probably located in the notochord.
(12) Adjacent to the caudal half of each somite, these cells penetrated no further than the myosclerotomal border, but opposite the rostral somite half, they were found next to the sclerotome almost as far ventrally as the notochord.
(13) These results indicate that 1) Engrailed-2 expression is suppressed in the most ventral neural tube owing to induction of the floor plate by the notochord, and 2) that the presence of an underlying notochord is not required for correct rostrocaudal expression, suggesting that multiple pathways act in the patterning of the rudiment of the central nervous system.
(14) Neural induction through the presumptive notochord was tested by means of the sandwich method.
(15) The notochord and neural tube are well developed by 3 days and surrounded by sclerotome, myotome, and dermatome cells.
(16) Minute fragments of the notochord of Balanoglossus sp.
(17) Glycosaminoglycans (GAG) are found primarily in the dorsal fin and in the ECM surrounding the notochord.
(18) Based on these facts, it is to be concluded that it is not the inducer of notochord, but the surrounding mesenchyme that is of primary importance for the determination of the types of neural tissue.
(19) A floor plate-specific chemoattractant was used as a marker to examine the role of the notochord in avian floor plate development.
(20) 2G9 was used to show that both notochord and somites are capable of neural induction, and the stimulus is present as late as stage 22.
Rod
Definition:
(n.) A straight and slender stick; a wand; hence, any slender bar, as of wood or metal (applied to various purposes).
(n.) An instrument of punishment or correction; figuratively, chastisement.
(n.) A kind of sceptor, or badge of office; hence, figuratively, power; authority; tyranny; oppression.
(n.) A support for a fishing line; a fish pole.
(n.) A member used in tension, as for sustaining a suspended weight, or in tension and compression, as for transmitting reciprocating motion, etc.; a connecting bar.
(n.) An instrument for measuring.
(n.) A measure of length containing sixteen and a half feet; -- called also perch, and pole.
Example Sentences:
(1) The NORPLANT-2 rod system on the other hand consists of only 2 rods.
(2) Since resistance is mainly mediated by R plasmids, we undertook to investigate the characteristics of R plasmid-determined beta-lactamase in 6 Gram-negative rods.
(3) Electroretinographic (ERG), morphometric and biochemical studies on retinas from monkeys or rats reveal that moderate level developmental lead (Pb) exposure produces long-term selective rod deficits and degeneration.
(4) Electron microscopy revealed the presence of a hitherto unreported peculiar "pilovacuolar" inclusion in numerous mitochondria, composed of an electron dense pile or rod within a vacuole, while globular or crystalline inclusions were absent.
(5) Changes in protein phosphorylation induced by phagocytic challenge were identified in cultured rat retinal pigment epithelium (RPE) following exposure to isolated rat rod outer segments (ROS) or to polystyrene latex microspheres (PSL).
(6) Thirty-six investigations were made using a number of lithium fluoride micro-rods for each investigation.
(7) After intravenous or dorsal lymph sac injections of 3H-22:6, most of the retinal label was seen in rod photoreceptor cells.
(8) The antigenic determinant defined by 5E9 was also shown to be present in a 87000 molecular weight polypeptide located in the proximal part of the flagellum of Crithidia oncopelti in which a paraflagellar rod is not detectable at the ultrastructural level.
(9) Chloride caused a significant concentration-dependent shortening of myosin rods due to destabilization of the alpha-helical double coiled rod structure.
(10) Rod adaptation was abnormal in both families, but the time course of adaptation differed between patients with the two mutations.
(11) Electron microscopy shows that at neutral pH, CEA particles consist of homogeneous, morphologically distinctive, twisted rod-shaped particles, about 9 X 40 nm.
(12) RCA-1, which is specific for D-galactose, showed patchy fluorescence on the basal and distal portions of the outer segments of the cones and rods, whereas neuraminidase-treated sections had uniform fluorescence throughout the tissues.
(13) All are satisfied by [Formula: see text], where N is the size of rod signal, constant for threshold; theta, theta(D) are steady backgrounds of light and receptor noise; varphi is the threshold flash with sigma a constant of about 2.5 log td sec; B the fraction of pigment in the bleached state.
(14) The territory’s chief executive Leung Chun-ying, has become a lightning rod for the protesters’ anger .
(15) Beyond intraoperative recognition and removal of the rods, effective strategies to prevent this neuronal loss have yet to be developed.
(16) Sensitivities to gentamicin, sissomicin, tobramycin, and amikacin were compared in 196 gentamicin-resistant Gram-negative rods and in 212 similar organisms sensitive to gentamicin, mainly isolated from clinical specimens.
(17) It should be considered as a causative agent in culture-negative cases of endocarditis and also when a gram-negative rod is isolated which is sensitive to all antibiotics.
(18) Rats permitted to recover for 13 weeks and then sacrificed had lost almost all their rods (p less than 0.001) while the cones were reduced by about 50% (p less than 0.01).
(19) The reports of rod-dominated psychophysical spectral sensitivity from the deprived eye of monocularly lid-sutured (MD) monkeys are intriguing but difficult to reconcile with the absence of any reported deprivation effects in retina.
(20) Rod adaptation had no reliable influence on response to rapid onset in cones or bipolar cells.