(1) Using a silver staining technique (AgNOR technique), we have investigated the nucleolar organizer-associated proteins (NORs) in formalin-fixed paraffin embedded conjunctival specimens of 15 intraepithelial squamous carcinomas, 10 hyperplastic-dysplastic samples and 10 control epithelial fragments; the mean number of intranuclear black dots was determined for each case.
(2) We have cloned and sequenced a DNA fragment from the genome of Drosophila melanogaster which is homologous to Novikoff hepatoma (rat) small nucleolar U3 RNA.
(3) They continuously produced heteropolymeric G6PD and showed strictly additive patterns of silver staining of both parental sets of nucleolar organizing chromosomes.
(4) After treatment, an increase in the nucleolar volume is observed.
(5) Both the usual nucleolar and non-nucleolar transcription complexes were visualized.
(6) When protein biosynthesis is inhibited by either cycloheximide of puromycine, the nucleolar RNA synthesis of Ehrlich ascites tumor cells decreases by approximately 70% within 1 h, while the removal of these protein synthesis inhibitors causes a rapid recovery of nucleolar RNA synthesis, largely within 1 h. A similar pattern of decrease and recovery of endogenous RNA polymerase activity in isolated nucleoli or in nuclei (in the presence of alpha-amanitin) may be demonstrated after addition and removal of these drugs.
(7) The two characteristic forms of eucaryotic DNA-dependent RNA polymerases, polymerase I (nucleolar) and polymerase II (nucleoplasmic), were identified.
(8) The morphologic basis for a nucleolar-cytoplasmic interrelationship via the nucleolar channel system is described.
(9) If purified nuclei were heated for 45 min at 37 degrees C, the final matrix exhibited well-recognizable nucleolar remnants, an inner network and a peripheral lamina.
(10) It is present on all seven rye chromosomes and hybridizes to the entire length of each chromosome, with the exception of some telomeres and the nucleolar organiser region.
(11) The description of the structure of epithelial cells includes: 1) the endoplasmic reticulum and ribosomes, 2) mitochondria, 3) the nucleus, 4) the golgi complex and secretory bodies, 5) lysosomes, 6) annulate lamellae, 7) luminal surface, 8) basal surface, 9) lateral surface, and 10) the nucleolar channel system.
(12) Changes in the nucleolar structure were noticed in hepatocytes administered both suramin and CCl4.
(13) We studied 20 gastric adenocarcinoma to determine DNA ploidy pattern by flow cytometry and nucleolar organizer regions by the colloidal silver method.
(14) Some of these genotypes are aneuploids with deletions or additions of chromosomes bearing nucleolar organisers.
(15) Nucleolar modifications induced by herpes simplex virus type 1 (HSV1) infection were studied at the ultrastructural level with special attention to the fate of a family of proteins serologically related to the nucleolar 100 kDa protein.
(16) The phosphatase was capable of dephosporylating the major phosphorylated nucleolar proteins C23-24 and B23-24 and also histone H1.
(17) Nucleolar organizer regions (NORs) are loops of DNA encoded for ribosomal RNA production.
(18) We analyzed the number and aspect of nucleolar organizer regions in 11 specimens from ampullary carcinoma, by means of silver colloidal staining.
(19) Nucleolar organizer regions are collections of nucleolar proteins associated with ribosomal genes that can be visualized in histologic sections using a silver colloid stain, thus the term silver-staining nucleolar organizer region (AgNOR).
(20) The results show that DHT induces a significant nucleolar enlargement but intranuclear migration of rRNA is not apparently affected by androgens; migration of RNA through euchromatin is delayed by castration and stimulated by DHT; migration through the nuclear envelope is androgen-dependent.
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.