Evaluacion de regiones de organizacion nucleolar (NORs) en infiltrados linfocitarios cutaneos / Valuation of necleolar organizer region (NORs) in cutaneous lymphocytic infiltrates

Los NORs son segmentos del brazo corto de determinados cromosomas acrocentricos, que se ponen en evidencia mediante la tincion argentica. Se estudiaron 10 seudolinfomas cutaneos, 6 reaccion por artropodos, 4 linfadenosis cutaneas benignas, 4 linfomas no Hodgkin de bajo grado, 3 linfomas no Hodgkin de alto grado y especimenes con infiltrado cutaneo no especificos. Los resultados demostraron que el indice de Ag NORs es de utilidad para diferenciar linformas de bajo grado con los de alto grado de malignidad. Tambien es de utilidad en el diagnostico diferencial entre seudolinfomas y linfomas, sumado a otros parametros

Contaje de las regiones de organizacion nucleolar(Ag-NORs)en proliferaciones melanociticas benignas y melanomas malignos / Counting of nucleolar organization regions(Ag-NORs)in bening melanocitic proliferations and malignant melanomas

Las Regiones de Organizacion Nucleolar (NORs), son segmentos delDNA, ubicados en el brazo corto de los cromosomas acrocentricos. En el presente estudio, evaluamos el indice de Ag NORs en las proliferaciones melanociticas benignas y en melanomas malignos cutaneos, en los distintos tipos histologicos y comparamos el contaje de Ag NORs segun la fase de crecimiento del melanoma para establecerlo como posible parametro pronostico. De acuerdo a nuestros resultados, el indice de Ag NORs es de utilidad diagnostica limitada para diferenciar lesiones benignas de malignas. La morfologia irregular y la dispersion de los puntos negros son de ayuda para diferenciar este tipo de lesiones. El grado de malignidad no es diferenciable a traves de este metodo. La diferencia existente entre losindices de Ag NORs en los estadios tempranos y tardios del melanoma, es un elemento mas en el diagnostico diferencial entre los focos de crecimiento

Evaluacion de regiones de organizacion nucleolar (NORs) en infiltrados linfocitarios cutaneos / Valuation of necleolar organizer region (NORs) in cutaneous lymphocytic infiltrates

Los NORs son segmentos del brazo corto de determinados cromosomas acrocentricos, que se ponen en evidencia mediante la tincion argentica. Se estudiaron 10 seudolinfomas cutaneos, 6 reaccion por artropodos, 4 linfadenosis cutaneas benignas, 4 linfomas no Hodgkin de bajo grado, 3 linfomas no Hodgkin de alto grado y especimenes con infiltrado cutaneo no especificos. Los resultados demostraron que el indice de Ag NORs es de utilidad para diferenciar linformas de bajo grado con los de alto grado de malignidad. Tambien es de utilidad en el diagnostico diferencial entre seudolinfomas y linfomas, sumado a otros parametros

Contaje de las regiones de organizacion nucleolar(Ag-NORs)en proliferaciones melanociticas benignas y melanomas malignos / Counting of nucleolar organization regions(Ag-NORs)in bening melanocitic proliferations and malignant melanomas

Las Regiones de Organizacion Nucleolar (NORs), son segmentos delDNA, ubicados en el brazo corto de los cromosomas acrocentricos. En el presente estudio, evaluamos el indice de Ag NORs en las proliferaciones melanociticas benignas y en melanomas malignos cutaneos, en los distintos tipos histologicos y comparamos el contaje de Ag NORs segun la fase de crecimiento del melanoma para establecerlo como posible parametro pronostico. De acuerdo a nuestros resultados, el indice de Ag NORs es de utilidad diagnostica limitada para diferenciar lesiones benignas de malignas. La morfologia irregular y la dispersion de los puntos negros son de ayuda para diferenciar este tipo de lesiones. El grado de malignidad no es diferenciable a traves de este metodo. La diferencia existente entre losindices de Ag NORs en los estadios tempranos y tardios del melanoma, es un elemento mas en el diagnostico diferencial entre los focos de crecimiento

Silver colloid staining technique for analysis of glioma malignancy.

A silver colloid staining technique for identifying nucleolar organizer region-associated proteins (Ag-NOR's) was applied to 51 human gliomas. These comprised 20 glioblastomas multiforme, 15 anaplastic astrocytomas, and 16 astrocytomas, in which the mean numbers of Ag-NOR's per cell (+/- standard error of the mean) were 2.51 +/- 0.12, 2.01 +/- 0.10, and 1.76 +/- 0.06, respectively. Significant differences among these were recognized, and the mean number of Ag-NOR's paralleled the degree of histopathological malignancy. In 16 cases, studies were performed of the number of Ag-NOR's and the S-phase fraction by in vitro labeling using antibromodeoxyuridine monoclonal antibody. A linear relationship was demonstrated between these two factors (r = 0.857, p less than 0.001), although some scatter was seen. In 32 adult patients, the correlation between the number of Ag-NOR's and the prognosis was estimated. The results demonstrated that the group containing patients with less than 1.80 Ag-NOR's per cell had a better prognosis than the group with 1.80 Ag-NOR's or more. Thus, the number of Ag-NOR's reflected the degree of histopathological malignancy, S-phase fraction, and prognosis. Silver colloid staining for Ag-NOR's is a simple, rapid, and reproducible method for estimating the proliferative potential of human gliomas without requiring a complicated technique.

Distribution of rDNA and 28S, 18S, and 5S rRNA in micronuclei containing a single chromosome.

Investigating genes and their transcription products in nuclear compartments corresponding to one mammalian chromosome, the ribosomal genes 18S-28S and 5S were localized in PtK1 micronucleated cells and rRNA was characterized in sorted micronuclei containing single identified chromosomes. In situ hybridization revealed the presence of 18S-28S rRNA genes in two micronuclei per cell and 5S rRNA genes in four micronuclei per cell. Flow cytometry histograms of isolated micronuclei stained with Hoechst 33342 exhibited five peaks (a-e) in which peaks b and c, respectively, corresponded to chromosomes 4 and X. Restricted genomic DNA from sorted peak c micronuclei showed the presence of 28S gene sequences. Direct sorting of the micronuclei from each peak on nitrocellulose and their hybridization with the 18S-28S rDNA probe revealed that the rRNA genes were exclusively located in micronuclei containing X chromosomes. Northern blotting showed the presence of 18S-28S and 5S rRNAs in peak c micronuclei and their absence from peak b micronuclei. Consequently, these procedures allowed us to show the presence of ribosomal genes and the corresponding rRNA in micronuclei containing single X chromosomes, and the absence of rRNA from micronuclei that do not contain the ribosomal genes. In regards to the transcription of these genes, the micronuclei from peak c can be considered as functional interphase X chromosomes.

Nucleolar organizer regions and Ki-67 immunostaining in ductal breast cancer: a comparative study.

53 cases of invasive ductal (NOS) carcinomas of the breast were studied by means of an immunostaining method with Ki-67 monoclonal antibody and an argyrophilic method for the demonstration of Nucleolar Organizer Regions (AgNORs). The percentage of cancer cells with nuclear Ki-67 immunoreactivity and the mean number of NORs for each tumour were statistically related. The data obtained showed a good correlation between Ki-67 index and NOR score (rS = 0.47 - P less than 0.001). The authors suggest that the AgNOR method--which is applicable to routinely processed material--might effectively substitute Ki-67 immunostaining as a marker of cell proliferation in ductal breast cancer.

Nuclear fraction enriched in interchromatin granules.

A fraction enriched in interchromatin granules (IG) has been obtained from isolated liver nuclei by digestion with DNase I and extraction with salt solutions. The fraction contains interchromatin granules in the form of conglomerations and some contaminating material of nucleolar and nuclear matrix origin. The ultrastructure of the fraction enriched in IG and electrophoretic patterns of proteins are described.

Variation within and between nucleolar organizer regions in Australian hylid frogs (Anura) shown by 18S + 28S in-situ hybridization.

Five distinct classes of secondary constriction are found in the hylid frogs from the genera Litoria and Cyclorana, each of which is defined by its C-banding pattern and morphology (King, 1980, 1987). In-situ hybridization experiments utilizing 18S + 28S copy RNA probes derived from Xenopus and Drosophila rDNA templates, were made on nine species of frogs possessing the major constriction types. Types 1, 2, 4, and 5 are confirmed as being NORs. These results also indicate that type 1 and 2 constriction types are not differentially despiralized as previously suggested, but show absolute differences in the quantity of ribosomal DNA present. This variation took two forms, deletion polymorphism and amplification polymorphism. These differences were observed between homologues within cells and between cells within individuals. Animals possessing these 'despiralized' constrictions are therefore mosaics for both deletion and amplification polymorphisms. Polymorphism frequencies vary greatly between constriction types. Some specimens have a higher level of presence/absence heterozygosity, (L. moorei, type 2, L. nannotis type 5, L. raniformis (animal A, pair 8 type 2), than do others (L. peronii, L. rothii, L. caerulea). The above species also vary markedly in the degree and frequency of amplification of the NORs. The type 4 constrictions analysed (L. coplandi, L. lesueuri and C. novaehollandiae) have a particularly low frequency of presence/absence heterozygosity, and they have fewer size heteromorphisms between homologues. The type 3 ephemeral constrictions did not hybridize to cRNA probes at any stage. In all but one of the species studied, a single pair of chromosomes possessed an NOR. However, in L. raniformis these occurred on two pairs of chromosomes.(ABSTRACT TRUNCATED AT 250 WORDS)

Recognition of the retrograde reaction in motoneurons using an image analysing system.

An automatic procedure is described which allows recognition of sectional profiles of alpha-motoneurons of the facial nucleus of the rat. The system is able to distinguish nucleus and nucleolus from the cytoplasm of the nerve cell profile and to characterize those structures by suitable parameters. The region of the nucleus of the facial nerve (FNN) has been measured 7 days after unilateral partial nerve transsection. Based on the resulting data a multivariate analysis was performed to distinguish between normal and retrograde reacting cells. It is shown that this automatic cell characterisation technique is highly sensitive and reliable. The data were used to describe comprehensively the retrograde reaction of the cell.

Prognostic value of nucleolar organizer regions and ploidy values in advanced colorectal cancer.

The prognostic value of nucleolar organizer regions and ploidy status in patients with Dukes' C colorectal cancer was determined. In addition, nucleolar organizer regions and ploidy status were compared with the established prognostic indices age, sex, tumour location and degree of histological differentiation. Fifty-one patients (27 men, 24 women) aged 35-81 years (median 64.8 years) were studied. Five years after presentation, 16 patients were alive and well. Survivors had significantly lower nucleolar organizer region counts (median value and range) in primary tumours 12 (8-15) and lymph node metastases 11 (8-15) than non-survivors 17 (14-25) and 18 (13-25) respectively (P less than 0.05). Fewer survivors had aneuploid tumours than non-survivors: four survivors compared with 17 non-survivors. In a regression analysis model, nucleolar organizer regions were the most important individual variable for predicting survival (chi2 = 15, P less than 0.01) while ploidy values (chi2 = 6, P less than 0.2) were equivalent to histological differentiation.

Differential decondensation of mitotic chromosomes during hypotonic treatment of living cells as a possible cause of G-banding: an ultrastructural study.

The chromosomal ultrastructure of Chinese hamster cells treated with 0.075 M KCl - a solution ordinarily used for making preparations of spread chromosomes - was studied. The hypotonic treatment was shown to result in differential decondensation of chromosomes which consists in the uneven distribution of deoxyribonucleoprotein (DNP) fibrils along chromatids. Fixation of cells with methanol acetic acid causes an abrupt restructuring of chromosomes. However, the DNP preserves its uneven distribution along chromatids. As seen on ultra-thin sections of marker nucleolus organizer chromosomes, the densely packed regions may correspond to G-bands detected in the selfsame chromosomes by standard methods of differential staining. The results suggest that the capacity of chromosomes for differential staining is based on the different resistance of G- and R-bands to the decondensing action of hypotonic solutions on living cells.

Argyrophil organizer region proteins (AgNORs) in adenohypophysial cells and adenomas of the human pituitary.

Nucleolar organizer regions (NORs), claimed to represent valuable markers of tumor proliferation, were visualized on paraffin sections by an argyrophil method and counted in 18 nontumorous adenohypophyses and 132 pituitary tumors. The AgNOR counts could not be correlated with the hormonal activity of nontumorous and adenoma cells. In pituitary adenomas, the mean AgNOR values were higher than in their corresponding nontumorous cell types. Some adenomas, especially growth hormone (GH), and prolactin (PRL) cell adenomas, however, had AgNOR readings in the range of nontumorous cells. Long-acting somatostatin analog and bromocriptine treatment decreased AgNOR counts in GR- and PRL-producing tumors. Most, but not all invasive and/or recurrent adenomas had high AgNOR counts. In a corticotroph carcinoma, AgNORs were not higher than in the adenomas. These inconsistent results limit, at the present time, the use of AgNORs as reliable markers of cell proliferation in pituitary tumors. Further studies may help to establish the value of this promising method in pituitary pathology.

The nucleolar organizer regions associated protein (Ag-NORs) in salivary gland tumors.

A silver colloid technique used to identify nucleolar organizer regions associated protein (Ag-NORs) has been applied to 20 salivary gland tumors. The method was readily applicable to the preparations of paraffin-embedded sections and the Ag-NORs were enumerated with ease. A significant difference was found between the numbers of Ag-NORs in the nuclei of malignant salivary gland tumors, such as adenoid cystic carcinoma, mucoepidermoid tumor and adenocarcinoma (with a mean of from 2.05 to 2.78 per nucleus) and those of benign salivary gland, such as pleomorphic adenoma, adenolymphoma (Wartin tumor) and clear cell adenoma (with a mean of from 1.47 to 1.72 per nucleus). It is proposed that the Ag-NORs technique, which is rapid, simple, and inexpensive, may be useful in the differential diagnosis of malignant and benign salivary gland tumors.

An assessment of the value of Ag NOR staining in the identification of dysplastic and other borderline melanocytic naevi.

One hundred and six melanocytic lesions were studied to determine the value of the so called Ag NOR technique in differentiating dysplastic naevi, Spitz naevi and spindle cell naevi of Reed from malignant melanoma and from 'banal' compound or intradermal naevi. In 79 cases Ag NOR counts were possible. The banal naevi (36) had a mean count of 1.54, (SD 0.3), and the unequivocally malignant superficial spreading melanomas (13), lentigo maligna melanomas (4) and secondary melanomas (4) had a mean count overall of 3.9 (SD 1.59). For dysplastic naevi (16) the mean Ag NOR count was 1.63 (SD 0.36) and for Spitz and spindle cell naevi (in toto 6) the figure was 1.72 (SD 0.55). The difference in Ag NOR counts between all types of naevi and all types of melanoma was highly statistically significant, but there was no difference between banal naevi and dysplastic, Spitz, and spindle cell naevi. Correlation of Ag NOR counts between three independent observers was good. This technique may, therefore, be a useful adjunct in separating true melanoma from borderline melanocytic naevi.

Silver staining of nucleolar organizer regions in malignant melanoma and melanotic nevi.

The recently described method of staining nucleolar organizer regions (NOR) with colloidal silver nitrate was applied to the paraffin sections of five junctional nevi, 13 compound nevi, seven Spitz nevi, nine cellular blue nevi, 11 dysplastic nevi, seven malignant lentigines, 12 superficial spreading melanomas, and 14 secondary melanomas. There was a significant difference between the pooled silver-NOR (AgNOR) numbers of the 45 benign lesions (mean, 1.22; SD, 0.51) and the 33 melanomas (mean, 9.18; SD, 4.05) by t test analysis (P less than .01). The difference was striking enough to be recognized on casual microscopic examination, suggesting that AgNOR staining may be a useful technique to help separate melanocytic nevi from malignant melanomas.