(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.
Vertebrate
Definition:
(n.) One of the Vertebrata.
(a.) Alt. of Vertebrated
Example Sentences:
(1) Local embolism, vertebral distal-stump embolism, the dynamics of hemorrhagic infarction and embolus-in-transit are briefly described.
(2) An axillo-axillary bypass procedure was performed in a high-risk patient with innominate arterial stenosis who had repeated episodes of transient cerebral ischemia due to decreased blood flow through the right carotid artery and reversal of blood flow through the right vertebral artery.
(3) Two cases of posterior lumbar vertebral rim fracture and associated disc protrusion in adolescents are presented.
(4) The greatest advantages of spinal QCT for noninvasive bone mineral measurement lie in the high precision of the technique, the high sensitivity of the vertebral trabecular measurement site, and the potential for widespread application.
(5) With the successful culture of these tissues, their development, biochemistry, and physiology, potentially of great importance in understanding early vertebrate evolution, can be better understood.
(6) In this paper, we examine corticosteroid 11 beta-oxidation and 11-reduction as properties of the microsomal 11 beta-hydroxysteroid dehydrogenase complex in vertebrate livers.
(7) The bony elements of both adjacent vertebral bodies are secondarily involved.
(8) Depending on local anatomical properties duplex scanning failed to make a decision about the state of the ostium of the vertebral artery in 24% of the cases.
(9) Neural crest cells give rise to various essential tissues in vertebrates.
(10) Per-rotational nystagmus was recorded in rabbits with unilaterally narrowed vertebral arteries or following unilateral cervical sympathectomies.
(11) We advance a structural model to account for the rapid elastic element seen in mechanical transient experiments on vertebrate skeletal muscle (A.F.
(12) Investigations have been made to determine the identity and binding characteristics of the pterins that are bound tightly to dihydrofolate reductases which are isolated from vertebrate sources by a well established procedure.
(13) We concluded that the primitive eukaryote D.discoideum contains proteins which show functional and physical similarity with the alpha-subunits of vertebrate G-proteins.
(14) For dinucleotides, TA is almost universally under-represented, with the exception of vertebrate mitochondrial genomes, and CG is strongly under-represented in vertebrates and in mitochondrial genomes.
(15) Genetic studies in yeast demonstrate that vertebrate calmodulin can functionally replace yeast calmodulin.
(16) The 76-residue protein exhibits one difference towards a murine form, is identical to other characterized vertebrate ubiquitins, and confirms an extensive conservation of the ubiquitin structure.
(17) This was true even when the locations of low resistance areas along the dorsal trunk were compared to only those vertebral palpatory findings rated as "severe."
(18) CT possesses some advantages over roentgenography in the diagnosis of degenerative vertebral diseases and can be recommended as the principal method together with roentgenography for investigation of patients with lumbar pains.
(19) Precedent exists for the early development and subsequent down-regulation of neurotransmitter receptor systems in the vertebrate central nervous system, but the function of such embryonic receptors has not been established.
(20) The authors report a case of primary aspergillus endocarditis with endophthalmitis and vertebral osteomyelitis.