What's the difference between nucleolus and nucleus?

Nucleolus


Definition:

  • (n.) A little nucleus.
  • (n.) A small rounded body contained in the nucleus of a cell or a protozoan.

Example Sentences:

  • (1) Aside from these characteristic findings of HCC, it was important to reveal the following features for the diagnosis of well differentiated type of small HCC: variable thickening or distortion of trabecular structure in association with nuclear crowding, acinar formation, selective cytoplasmic accumulation of Mallory bodies, nuclear abnormalities consisting of thickening of nucleolus, hepatic cords in close contact with bile ducts or blood vessels, and hepatocytes growing in a fibrous environment.
  • (2) Concurrently, stereology was applied to quantitate: (1) the density of RNA labelling, and (2) changes in the size of the nucleus and nucleolus in response to estrogen treatment.
  • (3) Interestingly, actinomycin D treatment dissociated centromeres from localization within the segregated nucleolus.
  • (4) In the hybrid cells the human nucleolus organizer regions are active, as shown by Ag-AS staining and involvement in "satellite association."
  • (5) From these findings it can be concluded that the transcription of ribosomal DNA takes place in the dense fibrillar component of the nucleolus.
  • (6) The existence of two nerve-cell types has been proved: clear ones-big, eggshape with nucleus and an obvious nucleolus; and darker ones-smaller, fusiforms, with nucleus and a less perceptible nucleolus.
  • (7) Immunoelectron microscopy revealed that in spermatogonia, leptotene and pachtyene spermatocytes, and in Golgi phase spermatids, B23 and nucleolin were localized in the dense fibrillar component and granular component of the nucleolus but not in the fibrillar centers.
  • (8) In Drosophila melanogaster males, X-Y meiotic chromosome pairing is mediated by the nucleolus organizers (NOs) which are located in the X heterochromatin (Xh) and near the Y centromere.
  • (9) Peripheral blood specimen showed abnormal lymphoid cells with an oval to cleaved nucleus, rather condensed chromatin, occasional prominent nucleolus, and basophilic cytoplasms with vacuoles which seems to be a T-cell counterpart of B-cell chronic lymphocytic leukemia with mixed cell types.
  • (10) Late in infection, an additional marked accumulation occurred in both fibrillar and granular components of the nucleolus.
  • (11) However, no definite nucleolus has been demonstrated in the endozoite nucleus.
  • (12) It occurs within an intact nuclear membrane and is characterized by the persistence of the nucleolus and its transformation into 2 polar masses.
  • (13) The nucleolus, initially clustered at the nucleus centre, undergoes dispersion and assembles again towards the end of embryonic development.
  • (14) The photodamage was limited to the nucleus and nucleolus.
  • (15) Turnover rates of the components of systems for RNA synthesis of rat-liver nucleus, nucleolus, and nucleoplasm were investigated.
  • (16) The blocking of IP by cordycepin and the lack of inhibition at the nucleolus level under the same conditions, show that the two early effects of the action of estrogen on the immature rat uterus are not directly correlated.
  • (17) The basally-located nucleus is irregularly shaped with fine granular euchromatin and some peripheral heterochromatin: satellite karyosomes border the nucleolus.
  • (18) By using this method, we were able to measure the area, length, and width of the cell, the area of the nucleus and nucleolus, and the position of the nucleus (i.e., eccentricity).
  • (19) The identified pre-rRNA components (45 S, 41 S, 39 S, 36 S, 32 S and 21 S) are confined to the nucleolus and constitute about 70% of its rRNA.
  • (20) At 0 h, there is a single large fibrillar center in each nucleolus which splits into smaller and more numerous FCs until the number of FCs reaches five, the number of nucleolus organizers in normal haploid human cells.

Nucleus


Definition:

  • (n.) A kernel; hence, a central mass or point about which matter is gathered, or to which accretion is made; the central or material portion; -- used both literally and figuratively.
  • (n.) The body or the head of a comet.
  • (n.) An incipient ovule of soft cellular tissue.
  • (n.) A whole seed, as contained within the seed coats.
  • (n.) A body, usually spheroidal, in a cell or a protozoan, distinguished from the surrounding protoplasm by a difference in refrangibility and in behavior towards chemical reagents. It is more or less protoplasmic, and consists of a clear fluid (achromatin) through which extends a network of fibers (chromatin) in which may be suspended a second rounded body, the nucleolus (see Nucleoplasm). See Cell division, under Division.
  • (n.) The tip, or earliest part, of a univalve or bivalve shell.
  • (n.) The central part around which additional growths are added, as of an operculum.
  • (n.) A visceral mass, containing the stomach and other organs, in Tunicata and some mollusks.

Example Sentences:

  • (1) Microionophoretically applied excitatory amino acids induced firing of extracellularly recorded single units in a tissue slice preparation of the mouse cochlear nucleus, and the similarly applied antagonist 2-amino-5-phosphonovalerate (2APV) was demonstrated to be a selective N-methyl-D-aspartate (NMDA) receptor antagonist.
  • (2) The present results provide no evidence for a clear morphological substrate for electrotonic transmission in the somatic efferent portion of the primate oculomotor nucleus.
  • (3) In the caudal spinal trigeminal nucleus (Vc), the collaterals of one half of the periodontium afferent fibers terminated mainly in lamina V at the rostral and middle levels of Vc.
  • (4) It is concluded that in the mouse model the ability of buspirone to reduce the aversive response to a brightly illuminated area may reflect an anxiolytic action, that the dorsal raphe nucleus may be an important locus of action, and that the effects of buspirone may reflect an interaction at 5-hydroxytryptamine receptors.
  • (5) hypoglossal nucleus), whereas in other areas the angiotensinogen gene was expressed only in a certain population of glial cells.
  • (6) Local application of 8-OH-DPAT (0-5 micrograms) into the median raphe nucleus, facilitated male rat sexual behavior, as evidenced by a decrease in number of intromissions preceding ejaculation and in time to ejaculation.
  • (7) In addition, lightly immunostained cells were distinguished in the caudal portion of the hypothalamic arcuate nucleus, area of tuber cinereum, retrochiasmatic area, and rostral portion of the paraventricular thalamic nucleus after colchicine treatment.
  • (8) Arising of the nucleus from a polyheteronomous nucleoid of proeukaryotes.
  • (9) It is possible that the IgE that linked abnormally with the propofol had specific binding sites for the phenyl nucleus and the isopropyl groups, which are present in propofol and many other drugs.
  • (10) We conclude that neuronal activities in the region of the retrofacial nucleus are important both in the integration of stimuli from the central chemoreceptors and in defining the discharge patterns of respiratory neurons.
  • (11) A 68 year-old man with a history of right thalamic hemorrhage demonstrated radiologically in the pulvinar and posterior portion of the dorsomedian nucleus developed a clinical picture of severe physical sequelae associated with major affective, behavioral and psychic disorders.
  • (12) While the heaviest anterogradely labeled ascending projections were observed to the contralateral ventral posterolateral nucleus of the thalamus, pars oralis (VPLo), efferent projections were also observed to the contralateral ventrolateral thalamic nucleus (VLc) and central lateral (CL) nucleus of the thalamic intralaminar complex, magnocellular (and to a lesser extent parvicellular) red nucleus, nucleus of Darkschewitsch, zona incerta, nucleus of the posterior commissure, lateral intermediate layer and deep layer of the superior colliculus, dorsolateral periaqueductal gray, contralateral nucleus reticularis tegmenti pontis and basilar pontine nuclei (especially dorsal and peduncular), and dorsal (DAO) and medial (MAO) accessory olivary nuclei, ipsilateral lateral (external) cuneate nucleus (LCN) and lateral reticular nucleus (LRN), and to a lesser extent the caudal medial vestibular nucleus (MVN) and caudal nucleus prepositus hypoglossi (NPH), and dorsal medullary raphe.
  • (13) In contrast to this, adrenalectomy decreased ANP levels markedly in the organum vasculosum laminae terminalis and preoptic periventricular nucleus, which are reportedly involved in the central regulation of salt and water homeostasis.
  • (14) The shape of the nucleus changes from ovoid to a distinctive, radially splayed lobulated structure.
  • (15) Immunocytochemical analysis also suggested that bFGF immunoreactivity was present in the nucleus as well as the cytoplasm of astrocytes and CA2 neurons.
  • (16) The effect of Y-516 on the hyperactivity induced by dopamine injected bilaterally into the nucleus accumbens was compared with those of clocapramine (CCP), haloperidol (HPD) and chlorpromazine (CPZ).
  • (17) Moderately differentiated tumor revealed a wider range of nucleus size, less clustering (coefficient--3.59) and more hyperchromatic (70.1%) and "bare" (49.4%) nuclei and large nucleoli (22.2%).
  • (18) The majority of intensively stained and densely packed cells have been observed in tv nucleus.
  • (19) Following electrical stimulation of the hypothalamic paraventricular nucleus (PVN) area, 21% of the neurons were orthodromically excited, 6% were inhibited and 2.5% were antidromically activated.
  • (20) Proenkephalin A-related immunoreactive neuronal perikarya were detected in the central gray, reticular formation, nucleus raphes, trapezoid body, nucleus parabrachialis lateralis and medialis, nucleus spinalis nervi trigemini, nucleus dorsalis nervi vagi, and in the nucleus tractus solitarii.