(n.) An eel-like marsipobranch of the genus Petromyzon, and allied genera. The lampreys have a round, sucking mouth, without jaws, but set with numerous minute teeth, and one to three larger teeth on the palate (see Illust. of Cyclostomi). There are seven small branchial openings on each side.
Example Sentences:
(1) The buccal glands of adults of the Southern Hemisphere lamprey Geotria australis consist of a pair of small, bean-shaped, hollow sacs, embedded within the basilaris muscle in the region below the eyes and to either side of the piston cartilage.
(2) The presence in lamprey kidney of a loop which is similar to Henle's loop in mammals and birds indicates that the development of the system of osmotic concentration conditioned by the formation in the kidney of the medulla and from a sharp increase in renal arterial blood supply.
(3) However, the granulocytes of fishes, studied thus far, show granules with only one type of inclusion, whereas in lamprey the granulocyte inclusions are variable in size and shape.
(4) The terminal of the lamprey was nakedly situated on the ventral surface, while that of the hagfish was always covered by the superficial glial layer.
(5) In addition teeth from adult lamprey were successfully cultured in vitro.
(6) Swimming in the lamprey is accomplished by the generation of a travelling wave of body curvature in which the phase coupling between segments is so controlled as to give approximately one full wavelength on the body at any swimming speed.
(7) In lampreys, the majority of HRP-labeled cells were located along the length of the brainstem reticular formation in the inferior, middle, and superior reticular nuclei of the medulla, mesencephalic tegmentum, and nucleus of the medial longitudinal fasciculus.
(8) Immunoreactivity of antisera directed against human neuropeptide Y (NPY), anglerfish polypeptide YG (aPY), bovine pancreatic polypeptide (bPP), salmon pancreatic polypeptide (sPP), porcine peptide tyrosine tyrosine (PYY), and salmon glucagon-like peptide (GLP) was investigated in the endocrine pancreas and anterior intestine of adult lampreys, Petromyzon marinus, by immunohistochemical analysis.
(9) The hemeproteins included human methemoglobin A, lamprey methemoglobin, metchlorocruorin, horse metmyoglobin, and horseradish peroxidase.
(10) In the lamprey only, weakly blue-green fluorescent subependymal cells were seen just beneath the central canal.
(11) Primary lateralis projections in silver lampreys, Ichthyomyzon unicuspis, and young adult sea lampreys, Petromyzon marinus, were examined utilizing silver impregnation of degenerating fibers and transganglionic transport of horseradish peroxidase.
(12) Intracellular recordings were made from 76 neurons belonging to various cell types in the lamprey spinal cord, and these neurons were subsequently stained with Lucifer yellow.
(13) The presumed lack of gonadotropin-releasing hormone in the nervus terminalis of lampreys is discussed.
(14) The structure and fine structure of the pituitary gland in the sea lamprey, Petromyzon marinus L., are described at all major stages in the life cycle.
(15) The results suggest that the lamprey spinal cord has several fiber systems containing peptides sharing immunogenic properties with mammalian neuropeptides.
(16) Antibodies against myelin proteins were utilized in the analysis of total particulate material from the brains of the agnathan hagfish and lamprey.
(17) A similar distribution of opioid binding sites was seen in the eel and lamprey brain.
(18) Fragments that consisted mainly of two polysaccharide chains joined by a short polypeptide bridge (doublets) were prepared from chondroitin sulphate-proteins of lamprey, sturgeon, elasmobranch and ox connective tissues after hydrolysis with trypsin and chymotrypsin.
(19) The presence of elastic-like fibers and elastin-like material within some lamprey cartilages implies that this protein may have evolved earlier in vertebrate history than has been previously suggested.
(20) Some immunological relatedness between the hagfish enzyme and the enzyme from lamprey or skate was demonstrated.
Primitive
Definition:
(a.) Of or pertaining to the beginning or origin, or to early times; original; primordial; primeval; first; as, primitive innocence; the primitive church.
(a.) Of or pertaining to a former time; old-fashioned; characterized by simplicity; as, a primitive style of dress.
(a.) Original; primary; radical; not derived; as, primitive verb in grammar.
(n.) An original or primary word; a word not derived from another; -- opposed to derivative.
Example Sentences:
(1) Cloacal exstrophy, centered on the maldevelopment of the primitive streak mesoderm and cloacal membrane, results in bladder and intestinal exstrophy, omphalocele, gender confusion, and hindgut deformity.
(2) Evx-1 RNA is first detected shortly before the onset of gastrulation in a region of ectoderm containing cells that will soon be found in the primitive streak.
(3) As an extension of the previous study which indicated that mesoglea is a primitive basement membrane which has retained some characteristics of interstitial extracellular matrix, the present study was undertaken to analyze the role of mesoglea components during head regeneration in Hydra vulgaris.
(4) neuroblastomas, primitive neuroectodermal tumours (PNETs), rhabdomyosarcomas and malignant lymphomas.
(5) We concluded that the primitive eukaryote D.discoideum contains proteins which show functional and physical similarity with the alpha-subunits of vertebrate G-proteins.
(6) Mechanisms are suggested whereby rudimentary appetitive programs already encoded along facing dendrite membrane pairs within the specialized intrafascicular milieu, may trigger and control nipple search and suckling in the still blind and only primitively mobile neonate.
(7) Thus, the progeny of infected primitive multipotential cells are competent to express integrated proviruses.
(8) Multiple tuberculomas have simulated either an alcoolic encephalopathy in one case or a primitive cerebral tumour in another one.
(9) This increased cell flow down the early stages of the red cell pathway in CML suggests that heightened proliferation and differentiation of primitive hemopoietic cells may be a more general phenomenon than previously suspected in this disease.
(10) The Lerner & Lerner Scale for assessing primitive defenses is reviewed.
(11) Only tumors of astrocytic lineage like astrocytomas and glioblastomas, or tumors of mixed lineage as oligo-astrocytomas and multipotential primitive neuroectodermal tumors (PNET) expressed TNF-alpha-like immunoreactivity.
(12) This epithelial cell was tentatively identified as primitive extraembryonic endoderm by its ultrastructural appearance and its possession of cytokeratin intermediate filaments.
(13) The long-term culture corresponded to mouse MXT and MCF-7 cell lines whereas the primary culture corresponded to primitive breast cancers squashed onto histologic slides and maintained in cultures for between 12 and 48 h. Cell proliferation was evaluated by means of digital cell image analysis of Feulgen-stained nuclei.
(14) From these facts, it was concluded that the follicular, as well as acanthomatous, ameloblastoma is liable to undergo squamous differentiation, whereas the plexiform ameloblastoma remains in primitive stage of tumor differentiation.
(15) A cluster of spermatogonia may be derived from one primitive germ cell and it develops round a "Sertoli" cell.
(16) Shielded marrow self renewal capacity, a measurement reflecting primitive hematopoietic stem cell function, remained depressed and did not recover with time.
(17) In a 3-year-old child, a rare combination of a Dandy-Walker syndrome, a primitive trigeminal artery and a facial haemangioma was found.
(18) As the histochemical and ultrastructural findings are non specific, we believe, according to recent opinions, that this tumor could originate in a very primitive cell, able to differentiate to endocrine or exocrine elements, almost always incompletely.
(19) It is likely that the development of these malignancies is an expression of the multipotential nature of primitive germ cells.
(20) Morphology of the mature spermatozoon is modified from that of the classic primitive or ect-aquasperm type by having 1) the acrosome embedded in the nucleus (the only known example within the Mollusca), 2) a deep basal invagination in the nucleus containing proximal and distal centrioles and an enveloping matrix (derived from the rootlet), 3) laterally displaced periaxonemal mitochondria, and 4) a tail extending from the basal invagination of the nucleus.