(n.) The marrow of bones; the deep or inner portion of an organ or part; as, the medulla, or medullary substance, of the kidney; specifically, the medula oblongata.
(n.) A soft tissue, occupying the center of the stem or branch of a plant; pith.
Example Sentences:
(1) Furthermore, the local interneurons make extensive efferent synaptic connections with unidentified neurons in the terminal medulla.
(2) These findings suggest that AAT participates in the synthesis of transmitter aspartate in the medulla oblongata of the rat.
(3) These included the noradrenergic, TH- and DBH-immunoreactive cell groups of the pons and medulla.
(4) Size of both areas gradually decreased as the medulla filled with plasma cells, 7-30 days after injection.
(5) Obvious restitution of the thymic medulla was evident about 14 days after withdrawal of FK506.
(6) + inf., pons + medulla), rCBF increased toward the control level gradually, and it completely recovered 60 min after recirculation.
(7) It is well established that the renal medulla exerts a potent endocrine-like antihypertensive action.
(8) It was found that within the dorsal part of the well known pressor area there is a narrow strip, 2.5 mm lateral from the mid line, starting ventral to the inferior colliculus and ending in the medulla close to the floor of the IV ventricle, from which vasodilatation in skeletal muscles is selectively obtained.
(9) Urea decreased and valine increased in the TD medulla-pons.
(10) The sizes of adrenaline (A) and noradrenaline (N) cells in the adrenal medulla of nonoperated (NO), sham-operated (SPX), and pinealectomized (PX) male rats (n = 126) were investigated by quantitative light microscopy.
(11) Injection of horseradish peroxidase into the rostral ventrolateral medulla (RVLM) led to heavy retrograde and anterograde labeling in the region of the hypothalamus that yielded the CRDR when stimulated electrically.
(12) The object of these studies was to investigate whether destruction of the renal medulla in normal rats would alter vascular capacitance.
(13) 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.
(14) Our results suggest that multiple receptors and signal transduction pathways are involved in the regulation of the tyrosine hydroxylase gene in the rat adrenal medulla.
(15) In hypertensive rats (SHR) the density of alpha 2-adrenoceptors was reduced in the cerebral cortex, hypothalamus and medulla oblongata (20-27%), as was the dose-pupillary response curve for clonidine (1.8-fold).
(16) An antihypertensive function in systemic blood pressure control has been attributed to the renal medulla.
(17) 1 After the injection of labelled procaine and lidocaine in mice, the location and concentration of radioactivity was demonstrated by autoradiographical methods.2 An accumulation in some endocrine cells such as the pancreatic islets, the hypophysis, the adrenal medulla and certain cells of the thyroid (probably representing the calcitonin-producing parafollicular cells) was shown.3 After the injection of [(14)C]-procaine in chicks, an accumulation of radioactivity was observed in the ultimobranchial gland (which produces calcitonin in birds), but not in the thyroid.4 Radioactivity was also shown to be strongly concentrated in structures containing melanin, such as the pigment of the eye, skin and hair and in some organs involved in the metabolism and excretion of these drugs.
(18) Histologically, increased amounts of fibrotic tissue in the medulla and the cortex were found together with tubular atrophy.
(19) Two well-defined zones are observed both in the medulla and in the cortex.
(20) One infant had a unilateral infarction in the medulla and another showed extensive gliosis in the brainstem tegmentum along with a large infarction in the region of the anterior cerebral artery.
Myelin
Definition:
(n.) A soft white substance constituting the medullary sheats of nerve fibers, and composed mainly of cholesterin, lecithin, cerebrin, albumin, and some fat.
(n.) One of a group of phosphorized principles occurring in nerve tissue, both in the brain and nerve fibers.
Example Sentences:
(1) Histological studies of nerves 2 years following irradiation demonstrated loss of axons and myelin, with a corresponding increase in endoneurial, perineurial, and epineurial connective tissue.
(2) Cranial MRI revealed delayed myelination in the white matter but no brain malformation.
(3) We have examined the initial events in myelin synthesis, including the insertion and orientation of PLP in the plasma membrane, in rat oligodendrocytes which express PLP and the other myelin-specific proteins when cultured without neurons (Dubois-Dalcq, M., T. Behar, L. Hudson, and R. A. Lazzarini.
(4) Electron microscopic observations of the masseter nerve in the aged cats revealed a disruption of the myelin sheaths and a pronounced increase in collagen fibers in the endoneurium and perineurium.
(5) At 7 days axonal swellings were infrequently observed and the main structural feature was a reduction in myelin thickness in affected nerve fibers.
(6) We measured CSF immunoreactive myelin basic protein (MBP), a marker of acute myelin damage, and sIL-2R levels in the CSF from 11 patients with active relapsing remitting (RR) MS, five with stable RR MS, eight with chronic progressive (CP) MS, five with other neurologic diseases, and three normal controls.
(7) Of 533 myelinated sensory fibers, the size range was 2 micron.
(8) However, when beta-xyloside-treated cultures were supplied with exogenous basement membrane, Schwann cells produced numerous myelin segments.
(9) TCR beta chain gene expression of individual T cell clones that share the same MHC class II restriction and similar fine specificity for the encephalitogenic NH2 terminus of the autoantigen myelin basic protein (MBP) has been examined.
(11) This histochemical difference corresponded to more subtle differences in Nissl and myelin staining patterns, and suggests further structural subdivisions of potential functional significance.
(12) At S-L clefts, paranodal-nodal regions, and Schwann cell nuclei, the axonal areas were smaller and the NF densities were higher than at compact myelinated regions.
(13) We find that the labelled cell has a myelinated axon, but that the axon loses its myelin within 50 microns of the soma and has not yet been traced further.
(14) The apparent Km values for the myelin and the microsomal enzyme were 1.3 X 10(-4) M and 4.3 X 10(-4) M, respectively.
(15) The antigen (a protein doublet of Mr 75,000-80,000) is present in, but not restricted to, the myelin lamellae, since it is distributed along the whole myelinating Schwann cell membrane.
(16) It has been shown previously that oligodendrocytes, which synthesize and maintain myelin in the central nervous system (CNS), are susceptible to attack by homologous complement and that injury may be reversible when lysis is resisted by vesicular removal of membrane attack complexes.
(17) To test whether congenital nemaline myopathy (NM) might have a neurogenic basis, we evaluated the number and frequency distribution of L5 motoneuron cell bodies and their myelinated ventral root (VSR) axons in a typical case.
(18) Pre-treatment of human neutrophils with myelin basic protein selectively inhibits the formyl-peptide-induced chemotaxis, without affecting chemotaxis evoked by casein and activated serum.
(19) A rapid loss of nerve fibres apparently occurred early in the course of compression, since there was a marked decrease in the amount of nerve fibre swelling and Marchi stained degenerating myelin with increasing clinical duration.
(20) The results from gel filtration of glycopeptides indicate that there is a higher content of large molecular weight, sialic acid-rich oligosaccharide units in the glycoprotein of immature myelin.