Nucleolar organizer regions identified by means of an argyrophilic technique (AgNOR) were quantified by digital image analysis in 81 patients with squamous cell carcinoma of the lung. Survival rate was modeled as function of AgNOR expression by Cox regression models controlled for staging, histologic grade, age, and sex. Our results indicate that AgNOR expression has a significant prognostic ro...

Material and Methods: The present study was conducted on 40 specimens of breast carcinoma out of which 12 cases were of Grade II and 28 cases were of Grade III. Percentage positivity and scoring of Ki-67 and mean AgNOR count was done with relation to grades. Observations: Ki-67 positivity was seen in 12 cases with the percentage positivity of 2.33±5.516 in grade II and 9.67±7.671 in grade III t...

The use of Toombak has been reported to play a major role in the etiology of oral cancer in Sudan. The cellular proliferative activity on the oral epithelium of 210 Toombak dippers was assessed by applying the micronuclei frequency, mean argyrophilic nucleolar organizer region (AgNOR) counts, Papanicolaou method, and 1% crystal violet stain. Participants were divided into 3 groups: 200 were app...

The simultaneous ultrastructural localization of the Ag-NOR proteins and ribonucleoproteins (RNP) was carried out during mitosis in human breast cancerous tissues using a one-step silver staining method followed by acetylation. Owing to the good preservation of the cells and to the high precision of the Ag staining we were able to follow the behaviour of the argyrophilic nucleolar components fr...

Cajal bodies (CB) are ubiquitous nuclear structures involved in the biogenesis of small nuclear ribonucleoproteins and show narrow association with the nucleolus. To identify possible relationships between CB and the nucleolus, the localization of coilin, a marker of CB, and of a set of nucleolar proteins was investigated in cultured PtK2 cells undergoing micronucleation. Nocodazol-induced micr...

The level of redundancy of ribosomal genes, and the relationship of this level to nucleolar formation at different stages of embryonic development, have been examined in the Mexican axolotl, Ambystoma mexicanum. Individuals from 4 inbred stocks were examined, as well as descendants from 2 nucleolar variants which, in the heterozygous condition, are distinguished by exceptionally small nucleoli....

Interspecific hybrids of D. melanogaster and D. simulans normally exhibit a secondary constriction only at the D. melanogaster nucleolus organizer (NO). This phenomenon, termed nucleolar dominance, occurs only when the NO-bearing sex chromosomes of both species are present in conjunction. Experiments were initiated to localize regions on the sex chromosomes of D. melanogaster involved in mediat...

Nucleolar RNA synthesis in salivary glands from XX, XY, and XO larvae having different numbers of nucleolus organizers was examined autoradiographically following incubation of the tissues in [H]uridine. In addition, the presence or absence of secondary constrictions was monitored in neuroblast preparations using acridine orange staining. It was observed that: (1) The rate of nucleolar [H]uridi...

In the present study, the chromosomes numbers were confirmed, 2n = 34 for Amaranthus cruentus Linnaeus, 1759, and 2n = 32 for Amaranthus hypochondriacus Linnaeus, 1753, Amaranthus mantegazzianus Passer, 1864, and Amaranthus caudatus Linnaeus, 1753. The distribution and variability of constitutive heterochromatin were detailed using DAPI-CMA3 banding technique. The position of the nucleolus orga...