Number of Nucleoli and Nucleolar Organizer Regions per Nucleus and Nucleolus — Prognostic Value in Canine Mammary Tumors

1996 ◽  
Vol 33 (5) ◽  
pp. 527-532 ◽  
Author(s):  
M. BratuliĆ ◽  
Ž GrabareviĆ ◽  
B. ArtukoviĆ ◽  
D. Capak
Keyword(s):  
Malignant Tumors ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Staining Technique ◽  
Mammary Tumors ◽  
World Health ◽  
Nucleolar Organizer Regions ◽  
Canine Mammary Tumors ◽  
Significant Difference

Twenty-eight canine mammary tumors were evaluated for histopathologic classification as recommended by the World Health Organization and silver-binding nucleolar organizer region (AgNOR) and nucleolus counts. Samples of surgically excised tumors and tumors taken at necropsy were fixed in neutral formalin, embedded in paraffin, and cut into 1-3-μm-thick sections. Two sections were taken from each tumor: one was stained with hematoxylin and eosin and the other was treated with the silver staining technique for the demonstration of AgNORs. After histopathologic classification, the number of nucleoli and the number of AgNORs/nucleus and AgNORs/nucleolus were determined. Statistical analysis (Student's t-test) showed a significant difference in the mean number of nucleoli ( P < 0.005), mean number of AgNORs/nucleolus ( P < 0.001), and mean number of AgNORs/nucleus ( P < 0.005) between benign and malignant canine mammary tumors. There was no significant differences between metastatic and nonmetastatic malignant tumors.

scholarly journals The Role of Argyrophilic Nucleolar Organizer Region (AgNOR) Study in Cytological Evaluation of Fluids, Especially for Detection of Malignancy

2012 ◽  
Vol 10 (1) ◽  
pp. 34-39 ◽  
Author(s):  
S Karki ◽  
A Jha ◽  
G Sayami
Keyword(s):  
Silver Staining ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Staining Technique ◽  
Nucleolar Organizer Regions ◽  
Serous Effusion ◽  
Malignant Cells ◽  
Associated Proteins ◽  
Malignant Effusions

Background Serous effusion smears reported as “suspicious for malignancy” pose problems in clinical management. Silver staining for argyrophilic nucleolar organizer regions (AgNOR) has proved useful in making a cytopathologic differential diagnosis between benign and malignant cells. Nucleolar organizer regions(NORs) are loops of DNA located in acrocentric chromosomes. These NORs are visualized by silver staining technique that recognizes these argyrophilia associated proteins which are increased in malignancy. Objective This study aimed to distinguish reactive mesothelial cells from malignant cells in serous effusions using these NORs. Methods A total of 174 serous effusions received at the Department of Pathology, TUTH, during a period of one year were included in the study. Smears were studied by conventional Papanicolaou and Giemsa stains. AgNOR counts, variation in size and dispersion of AgNOR dots in smears were graded and compared in malignant and non-malignant effusions. Results Mean AgNOR counts of 10.43±0.73 and 10.21±0.51 in malignant peritoneal and pleural effusions, respectively, were significantly (p<0.0001) greater as compared with counts of 2.12±0.54 and 2.11±0.54 in non-malignant effusions. The AgNORs were irregular in shape in malignant effusions whereas they were comparatively larger, single dots in benign effusions. AgNOR size and dispersion were of higher grade in significantly greater proportion of malignant as compared with non malignant effusions (p<0.0001). Of the cytologically suspicious samples, nine were in the malignant range and one was in the benign range. Conclusion AgNOR study appears to be clinically useful as an additional diagnostic tool for use in serous effusion when the cytologic diagnosis is difficult. KATHMANDU UNIVERSITY MEDICAL JOURNAL  VOL.10 | NO. 1 | ISSUE 37 | JAN - MAR 2012 | 44-47 DOI: http://dx.doi.org/10.3126/kumj.v10i1.6913

scholarly journals The Correlate between Argyrophilic Nucleolar Organizer Region Stain and Ki-67 Immnochistochemistry in Diagnostic Breast Cancer

2020 ◽  
Vol 2 (4) ◽  
pp. 285-292
Author(s):  
Hassan ALgarsh ◽  
◽  
Hana Abusaida ◽  
Fairouz Torjman ◽  
◽  
...  
Keyword(s):  
Malignant Tumors ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Breast Lesions ◽  
Silver Stain ◽  
Ki 67 ◽  
Significant Difference ◽  
Argyrophilic Nucleolar Organizer Region ◽  
Brown Color

Introduction: This experimental study gauged the value of argyrophilic nucleolar organizer region (AgNOR) staining as a possible technique for the estimation of cell kinetics in conventional histology sections, in benign and malignant breast lesions. Methods: With a silver staining technique and immunohistochemistry, we associated the numbers of AgNORs and Ki67 scores in 30 breast carcinomas and 10 benign breast lesions. Results: The mean values of Ag NORs silver stain dots count for normal, benign, grade II and III were 1.28±0.17, 2.83±0.68, 5.23±0.87 and 7.32±0.92, respectively. There was a statistically significant difference (p≤0.001) was noticed between the all individual groups, among the normal and breast lesion as well as among the GII and GIII. Immunohistochemical Results of Ki-67 protein exhibited homogenous golden-brown color in control case and a positive brown granules or diffuse dark brown color in the nuclei of both benign and malignant cases under the 400X magnify examined under the light microscope. Discussion: AgNOR counts performed on routine formalin-fixed paraffin sections could provide substantial kinetic evidence. Additionally, the difference in AgNOR counts between benign and malignant tumors is such that they may be of diagnostic worth.

Nucleologenesis in Trypanosoma cruzi

2016 ◽  
Vol 22 (3) ◽  
pp. 621-629 ◽  
Author(s):  
Tomás Nepomuceno-Mejía ◽  
Reyna Lara-Martínez ◽  
Roberto Hernández ◽  
María de Lourdes Segura-Valdez ◽  
Luis F. Jiménez-García
Keyword(s):  
Cell Division ◽  
Trypanosoma Cruzi ◽  
Ethylenediaminetetraacetic Acid ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Light And Electron Microscopy ◽  
Nucleolar Organizer ◽  
Nuclear Bodies ◽  
Nucleolar Organizer Regions ◽  
Nucleolar Material

AbstractNucleolar assembly is a cellular event that requires the synthesis and processing of ribosomal RNA, in addition to the participation of pre-nucleolar bodies (PNBs) at the end of mitosis. In mammals and plants, nucleolar biogenesis has been described in detail, but in unicellular eukaryotes it is a poorly understood process. In this study, we used light and electron microscopy cytochemical techniques to investigate the distribution of nucleolar components in the pathway of nucleolus rebuilding during closed cell division in epimastigotes of Trypanosoma cruzi, the etiologic agent of American trypanosomiasis. Silver impregnation specific for nucleolar organizer regions and an ethylenediaminetetraacetic acid regressive procedure to preferentially stain ribonucleoprotein revealed the conservation and dispersion of nucleolar material throughout the nucleoplasm during cell division. Furthermore, at the end of mitosis, the argyrophilic proteins were concentrated in the nucleolar organizer region. Unexpectedly, accumulation of nucleolar material in the form of PNBs was not visualized. We suggest that formation of the nucleolus in epimastigotes of T. cruzi occurs by a process that does not require the concentration of nucleolar material within intermediate nuclear bodies such as mammalian and plant PNBs.

scholarly journals Silver staining of the nucleolar organizer regions (NORs) on Lowicryl and cryo-ultrathin sections.

1985 ◽  
Vol 33 (5) ◽  
pp. 389-399 ◽  
Author(s):  
F J Moreno ◽  
D Hernandez-Verdun ◽  
C Masson ◽  
M Bouteille
Keyword(s):  
Silver Staining ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Enzymatic Digestion ◽  
Rnase A ◽  
Micrococcal Nuclease ◽  
Nucleolar Organizer Regions ◽  
Step Procedure ◽  
Ultrathin Sections

Nucleolar organizer region (NOR) silver staining was applied to sections of fixed material. A positive reaction on cryo-ultrathin sections was found as well as on semithin and ultrathin Lowicryl sections. Repeatable staining that was easy to control was obtained by a one-step procedure after aldehyde-Carnoy fixation. Fixation of the material by formaldehyde and glutaraldehyde alone in cacodylate buffer also maintained reaction selectivity when ammonium chloride was used after fixation. Enzymatic digestion by pronase, RNase A, DNase I, or micrococcal nuclease was applied to ultrathin Lowicryl sections. Pronase digestion removed the silver-stained proteins, whereas digestion by the nucleases did not. A routine procedure is proposed for easy NOR silver staining of sections that preserves a good tissue ultrastructure and is also compatible with cytochemical and immunological investigations.

scholarly journals Canine Mammary Tumors: Comparison of Classification and Grading Methods in a Survival Study

2018 ◽  
Vol 56 (2) ◽  
pp. 208-219 ◽  
Author(s):  
Ana Canadas ◽  
Miguel França ◽  
Cristina Pereira ◽  
Raquel Vilaça ◽  
Hugo Vilhena ◽  
...  
Keyword(s):  
Prognostic Factors ◽  
Malignant Tumors ◽  
Mammary Tumors ◽  
Classification Systems ◽  
World Health ◽  
Benign Tumors ◽  
Histological Subtype ◽  
Canine Mammary Tumors ◽  
Nottingham Grade ◽  
Health Organization

Histopathology remains the cornerstone for diagnosing canine mammary tumors (CMTs). Recently, 2 classification systems (the World Health Organization [WHO] classification of 1999 and the proposal of 2011) and 2 grading methods based on the human Nottingham grade have been used by pathologists. Despite some evidence that the histological subtype and grade are prognostic factors, there is no comprehensive comparative study of these classification and grading systems in the same series of CMTs. In this study, the 2 classifications and the 2 grading methods were simultaneously applied to a cohort of 134 female dogs with CMTs. In 85 animals with malignant tumors, univariable and multivariable survival analyses were performed. Using the 2 systems, the proportion of benign (161/305, 53%) and malignant (144/305, 47%) tumors was similar and no significant differences existed in categorization of benign tumors. However, the 2011 classification subdivided malignant tumors in more categories—namely, those classified as complex, solid, and tubulopapillary carcinomas by the WHO system. Histological subtype according to both systems was significantly associated with survival. Carcinomas arising in benign tumors, complex carcinomas, and mixed carcinomas were associated with a better prognosis. In contrast, carcinosarcomas and comedocarcinomas had a high risk of tumor-related death. Slight differences existed between the 2 grading methods, and grade was related to survival only in univariable analysis. In this cohort, age, completeness of surgical margins, and 2 index formulas adapted from human breast cancer studies (including tumor size, grade, and vascular/lymph node invasion) were independent prognostic factors.

scholarly journals Nucleolar Organizer Regions (NORs)

1994 ◽  
Vol 112 (4) ◽  
pp. 642-645
Author(s):  
Albina Messias de Almeida Milani Altemani
Keyword(s):  
Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Nucleolar Organizer ◽  
Staining Technique ◽  
Parasitic Infections ◽  
Nucleolar Organizer Regions ◽  
Mean Values ◽  
Significant Difference ◽  
Grade 3

Counts of nucleolar regions (NORs) demonstrated by a silver staining technique in paraffin sections, have been used to distinguish between benign and malignant lesions. AgNORs were studied in 24 biopsies from oral cavity (5 cases of normal oral mucosa, 5 of pseudocarcinomatous hyperplasia and 14 of squamous cell carcinoma, subdivided according to degree of differentiation: 5 grade 1, 5 grade 2 and 4 grade 3) to find whether they were helpful in distinguishing pseudocarcinomatous hyperplasia due to chronic parasitic infections from squamous cell carcinoma. Two methods of counting AgNORs were used: (A) a simpler one which counts nucleolar clusters (AgNU) and satellite AgNORs and the other (B) counting all individual AgNORs, including those within AgNUs. In both methods the lowest mean values were observed for grade 3 carcinoma, while the highest belonged to grade 2 carcinoma. The simpler method (A) was the most useful because AgNU counts showed significant difference when pseudocarcinomatous hyperplasia was compared with grade 1 and 2 carcinomas, which are the most difficult to discriminate from it. However the overlapping of values render the technique of limited use in individual cases.

scholarly journals Preliminary investigation on the variation of the nucleolar organizer region in the breeding chinchilla karyotype

2016 ◽  
Vol 72 (6) ◽  
pp. 373-377 ◽  
Author(s):  
Marta Kuchta-Gładysz ◽  
Agnieszka Otwinowska-Mindur ◽  
Piotr Niedbała ◽  
Olga Szeleszczuk ◽  
Joanna Głowacka
Keyword(s):  
Silver Staining ◽  
Organizer Region ◽  
Preliminary Investigation ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Nucleolar Organizer Regions ◽  
Silver Deposit ◽  
Nor Polymorphism ◽  
The Mean ◽  
Class Iv

The objective of this study was to determine the variation in the number and size of nucleolar organizer regions (NOR) in the chinchilla karyotype. The study was performed with 12 standard chinchillas of two different lines. NORs were visualized on chromosome preparations by Ag-NOR silver staining. Four NOR size classes (I-IV) were determined on the basis of the results obtained, ranging from 0.070 (class I) to 0.229 (class IV). The mean NOR size was 0.144 µm² (SD=0.031 µm²) and fell within class II (from 0.101 to 0.150 µm²). Differences in the relative silver deposit area between the NOR-bearing pair of chromosomes were significant for 3 animals (P < 0.01) and for 1 animal (P < 0.05). The mean number of NORs in the animals ranged from 1.4 to 2.0 (SD=0.00–0.55). It was lower for chinchillas from central Poland (1.53±0.50) compared to those from southern Poland (1.68±0.48), with no significant differences (P > 0.05). The variation observed in the NOR size and number in the chinchilla karyotype indicates the occurrence of NOR polymorphism in the population.

scholarly journals In situ fluorescent visualization of nucleolar organizer region-associated proteins with a thiol reagent.

1993 ◽  
Vol 41 (9) ◽  
pp. 1413-1417 ◽  
Author(s):  
G Méhes ◽  
E Kálmán ◽  
L Pajor
Keyword(s):  
Silver Staining ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Nucleolar Organizer Regions ◽  
Thiol Reagent ◽  
Sh Group ◽  
Associated Proteins ◽  
Rnase Digestion

Nucleolar organizer regions (NORs) are nucleolus-forming rDNA loops associated with argyrophil proteins, the amount of which varies according to the proliferative state of the cell. It has been presumed that the nucleolar protein-related thiol groups may have a role in selective silver staining. We investigated the nuclear thiol distribution with a fluorescent thiol reagent, coumarinyl-phenyl-maleimide (CPM) in human K-562 myeloblast cultures and found that SH group-related fluorescence was brightest in the area of nucleoli, which became highly selective after RNAse digestion. A remarkable co-localization of AgNOR silver reaction and CPM fluorescence was observed, although occupation of the SH groups by CPM did not prevent the silver staining. We applied the stain to dual-parameter flow cytometry in combination with DNA content measurements, which provide further information on nucleolar function and changes in experimental and pathological specimens.

Quantitative analysis of the variability of nucleolar organizer regions in Salmo trutta

Genome ◽  
1993 ◽  
Vol 36 (6) ◽  
pp. 1119-1123 ◽  
Author(s):  
P. Martínez ◽  
A. Viñas ◽  
C. Bouza ◽  
J. Castro ◽  
L. Sánchez
Keyword(s):  
Quantitative Analysis ◽  
Salmo Trutta ◽  
Chromosome Region ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Size Variation ◽  
Nucleolar Organizer ◽  
Chromosome Length ◽  
Nucleolar Organizer Regions ◽  
Structural Polymorphism

A quantitative analysis combined with Ag staining was carried out to study the size variation of the main nucleolar organizer region (NOR) bearing chromosome pair 11 of Salmo trutta. A standardized NOR size measurement was developed by comparing the length of the short arm (NOR-bearing region) to the total chromosome length. Statistical procedures support arguments for the existence of a large and structural polymorphism within this species for this chromosome region. A minimum of five different chromosome classes were identified, which account for the total variation found. Size variation among classes was due both to changes in the number of NOR clusters as well as to the amount of rDNA genes within each cluster. NOR size values were normally distributed in the sample analyzed.Key words: nucleolar organizer region, size polymorphism, brown trout.

Cytogenetic studies in North American minnows (Cyprinidae). XXII. Chromosomal nucleolar organizer regions in the genus Pimephales

1991 ◽  
Vol 69 (11) ◽  
pp. 2826-2830 ◽  
Author(s):  
Yucheng Li ◽  
John R. Gold
Keyword(s):  
North American ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Nucleolar Organizer Regions ◽  
Submetacentric Chromosome ◽  
The North ◽  
Extant Species ◽  
Previous Hypothesis ◽  
Chromosomal Data

Chromosomal nucleolar organizer region (NOR) phenotypes are documented for all four extant species in the North American cyprinid fish genus Pimephales. All four species (P. notatus, P. promelas, P. tenellus, and P. vigilax) possess 2n = 50 chromosomes and a pair of NOR-bearing chromosomes with the NOR situated terminally on the short arm of a medium-sized to large submetacentric chromosome (NOR phenotype C). Trypsin G-banding demonstrated that the C NOR chromosome in all four species is homologous. Two of the species (P. tenellus and P. promelas) also possess a C′ NOR chromosome, which is defined as an NOR situated terminally on the short arm of a large submetacentric chromosome that is also the largest chromosome in the complement. The C′ NOR chromosome occurs infrequently in P. promelas, being found in only 8% or so of all metaphases examined. Trypsin G-banding demonstrated that the C′ NOR chromosomes in the two Pimephales species are homologous to one another and to the C′ NOR chromosomes found in the cyprinid genus Cyprinella. A presumed derivative of the C′ NOR chromosome occurs in the monotypic cyprinid genus Opsopoeodus. The NOR chromosomal data support monophyly of the four extant species of Pimephales, and further suggest that the genus Pimephales belongs in a monophyletic assemblage with, among others, the cyprinid genera Cyprinella and Opsopoeodus. The data do not support the previous hypothesis that Pimephales is a basal clade outside of a larger assemblage of "Notropis"-like, shiners.

Sign in / Sign up

Export Citation Format

Share Document