Quantification of AgNOR expression in exfoliated oral mucosal cells of tobacco chewers with and without lesion.

Background: Nucleolar organizer regions (NOR) are associated with proliferative activity and represent a diagnostic and prognostic marker. Materials and Methods: Smears were taken from smokers, tobacco chewers, oral squamous cell carcinoma patients, and normal subjects and evaluated by 2 silver-staining nucleolar organizer region (AgNOR) counting methods: (1) mean number of AgNORs per nucleus (mAgNOR); and (2) percentage of nuclei with >3 and >5 AgNORs (pAgNOR). Results: A statistically significant difference was observed between normal subjects, smokers, tobacco chewers, and oral cancer patients and between tobacco chewers with and without lesion. No significant difference was observed between tobacco chewers and smokers except in the percentage of >5 criteria. Conclusions: AgNOR enumeration using noninvasive methods, such as the cytobrush appears to be useful technique in distinguishing between normal mucosa, mucosa with and without lesions exposed to carcinogens, such as tobacco and frank oral carcinoma.

AgNOR polymorphism association with squamous intraepithelial lesions and invasive carcinoma with HPV infection / Asociación de los polimorfismos AgNORs con lesiones intraepiteliales escamosas, carcinoma cervical e infección por VPH

OBJECTIVE: Evaluate the relationships between AgNORs polymorphisms and squamous intraepithelial lesions (SIL) and squamous cell carcinoma (SCC) with HPV infection. MATERIALS AND METHODS: A study was carried out on sixty women from the state of Guerrero, Mexico. HPV detection was performed by PCR. AgNORs were identified by argentic impregnation. One hundred cells per slide were counted and classified according to the polymorphism of AgNORs dots; typical (spherical) and atypical (large, kidney-shaped and clustered). RESULTS: A total of 100 percent of the cases were positive for HPV infection. Nine different high-risk HPV genotypes were found, type16 was the most common (48.6 percent). The AgNORs showed a significant decrease in spherical shape according to neoplastic development. The three atypical shapes showed a significant increase in SIL and SCC (p-trend<0.001). CONCLUSIONS: AgNORs polymorphism rises progressively according to the grade of histological lesions that can be useful as a prognosis for progression of SCC.

OBJETIVO: Evaluar la relación entre los polimorfismos de AgNORs con las lesiones intraepiteliales escamosas (LIE) y carcinoma de células escamosas (CCE). MATERIAL Y MÉTODOS: Se estudiaron sesenta mujeres del estado de Guerrero, México. La detección del VPH fue por PCR y los AgNORs por impregnación argéntica; se contaron 100 células y se clasificaron por tipo de polimorfismo de AgNORs: típico (esférico) y atípicos (largo, forma de riñón o de racimo). RESULTADOS: El 100 por ciento de los casos presentaron infección por VPH, se encontraron nueve genotipos diferentes de VPH de alto riesgo, el 16 fue el más común (48.6 por ciento). La forma esférica de los polimorfismos de AgNORs mostró una disminución con el desarrollo neoplásico y las atípicas incrementaron progresivamente con SIL y SCC (p-tendencia<0.001). CONCLUSIONES: Los polimorfismos AgNORs se incrementan progresivamente con el grado de lesión histológica, y pueden ser útiles en el pronóstico de progresión del carcinoma cervical.

Evaluation of AgNORs in pulmonary lesions: a cyto-histopathological correlation.

Silver nucleolar organizer regions (AgNORs) were studied in one hundred specimens of endobronchial brushings. Bronchial biopsies were also obtained from these one hundred cases and subjected to AgNOR staining. These included twenty histologically normal cases, ten cases of inflammatory pathology and seventy cases of pulmonary neoplasms. Fixed cytologic smears and three micron thick sections of paraffin embedded tissue were subjected to AgNOR staining. The mean AgNOR counts in bronchial tissue showed a progressive and statistically significant increase from normal, through inflammatory to neoplastic lesions in both cytologic smears and histopathologic specimens. The AgNOR technique is simple, inexpensive and a useful adjunct to routine histopathology, to evaluate pulmonary lesions. The counts, however, cannot be standardized for a particular lesion as there are inter-laboratory variations.

A qualitative and quantitative estimation of AgNORS in dysplastic and non-dysplastic leukoplakias.

Using a silver staining technique, nucleolar organizer region--associated proteins (AgNORS) were studied in formalin, fixed paraffin embedded tissue blocks of normal oral buccal mucosa epithelium, leukoplakia with dysplasias and leukoplakia without dysplasias. Fifty cases, that comprised of 10 cases of normal oral buccal mucosa epithelium and 40 cases, of leukoplakia without dysplasia and with mild, moderate and severe leukoplakia were examined with respect to the relationship between AgNOR counts and histologic grading. The mean AgNOR count per nucleus increased from normal oral buccal mucosa epithelium to leukoplakia without dysplasia to leukoplakia with dysplasia. Higher counts, wider scatter and smaller size of AgNOR in the nuclei were seen as the grading of dysplasia increased from mild to severe. It is suggested that this method has potential in distinguishing between dysplastic and non dysplastic leukoplakias and for early diagnosis, prognosis and treatment planning of dysplastic lesions.

The role of quantitative methods in the cytopathological diagnosis in serous effusions / O papel de métodos quantitativos no diagnóstico citopatológico de derrames cavitários

Uma revisäo crítica dos métodos quantitativos é feita focando suas aplicaçöes na prática laboratorial. Limitaçöes da citopatologia convencional também é discutida. Perspectivas do alcance diagnóstico e prognóstico dos métodos quantitativos säo apresentados

AgNORs in endometrial lesions.

Silver nucleolar organizer region (AgNOR) staining was employed in one hundred specimens of endometrium. These included fifteen normal controls (Proliferative + Secretory endometrium) and eighty five lesions. Endometrial lesions comprised of endometritis (15), endometrial hyperplasia (25) and endometrial carcinoma (45). Three micron thick sections of paraffin embedded tissue were subjected to AgNOR staining as described by Crocker and Smith with a little modification of 0.01% safranin counterstain--The mean AgNOR scores were found to increase steadily from normal to endometritis to endometrial hyperplasia and carcinoma--The observations revealed statistically significant differences in values between atypical hyperplasia and carcinoma also. AgNOR staining and scoring is simple, inexpensive and a useful adjunct to routine histopathology to evaluate endometrial lesions especially to differentiate borderline lesions. Though scores cannot be standardized and fixed for a particular lesion as there are intralaboratory variations.

Activity satellite association and polymorphismo of Ag stained nucleolus organizer regions (Ag+ NORs) in lymphocytes from women with cervical uterine cancer

Thirty five female patients with different stages of neoplastic lesions: cervical intraepithelial neoplasia (CIN) or dysplasia (CIN I and CIN II), in situ carcinoma (CIS), and adenocarcinoma, and 27 healthy women (controls) wee studied to determine the activity, satellite association, and jpolymorphism of Ag stained nucleolus organizer regions (Ag+NORs) in acrocentric chromosomes in metaphases obtained from peripheral blood lymphocytes. For each person, 25 to 50 metaphases stained with ammoniacal silver technique were scored. The average number of Ag+ NORs was higher in women with adenocarcinoma (7.66 ñ 0.72) than in controls (6.65 ñ 0.74). Non-associated chromosomes showing Ag+ NORs were found more frequently in patients (5.85 ñ 0.88) than in controls (4.81 ñ 0.67). Patients aged 30-39 and 60 or more had an increase of Ag+ NORs (7.99 ñ 1.04, and 7.81 ñ0.71) with respect to their controls (6.36 ñ 0.052 and 6.17 ñ 0.88), but the frequency of satellite association showed lower values in 50 -59 year-old patients (0.75 ñ 0.08) than in controls (1.02 ñ 0.19). The most frequent association in patients was the large type (patients = 38.96 perecent, controls 30.49 ). The partial association showed higher values (6.49 percent) than controls (2.44 percent). Otherwise, the spherical association was more frequent for controls (37.80 percent) than for patients (28.57 percent). All these differences were statistically significant (p<0.05). The frequency of Ag+ NORs and the type of polymorphism of satellite association could be related to the neoplastic process, while the frequency of satellite association and of polymorphism of Ag+ NORs seems to be irrelevant

Nucleolar organizer regions in a model of cell hyperactivity and regression

Nucleolar organizer regions stained with colloidal silver techniques (AgNOR) evidence sites of active rRNA transcription. It has been proved that AgNOR undergo a rise in number and variations in size and shape in conditions which traditionally involve enhanced cell proliferation and rRNA transcription. AgNOR have been described as a marker of malignant transformation in multiple entities. Our laboratory has previously described their value as markers of radioinduced damage. The finding, at light microscopy level, that silver staining persisted at later post-irradiation times when cells are characteristically inactive, prompted the present study to correlate findings at light microscopy level with the ultrastructural analysis of nucleoli and their AgNOR in a model of irradiated skin. We herein attempt to explain the biological significance of AgNOR variations in the different phases of radioinduced response (which involves cellular hyperactivity followed by regressive features). Ten Wistar rats were submitted to local irradiation of the left leg (the shielded right leg was used as control) with 50 Gy x rays and killed 15 days post- irradiation. Silver staining was performed on ultrathin sections. In the basal layer of control epithelium silver affinity was established for fibrillar centers (FC) and fibrillar dense components (DFC). During the phase of radioinduced hyperplasia (1-3 days post-exposure) basal cells exhibit large reticular nucleoli, with irregular contours and silver staining on DFC. In the regressive phase (4-5 days post-irradiation) silver staining persists despite the halt in transcriptional activity, associated to homogeneous and compact nucleoli. These findings suggest caution in the interpretation of silver staining patterns.

Estudo comparativo das proteínas p53, PCNA, Ki-67 e das regiöes organizadoras nucleolares (NORs) no epitélio de revestimento da mucosa próximo ao carcinoma epidermóide de boca / p53, PCNA, Ki-67 and NORs in lining epilhelium adjacent to squamous cell carcinoma of human oral mucosa

O epitélio de revestimento da mucosa adjacente aos carcinomas epidermóides pode apresentar alteraçöes morfológicas e histoquímicas representativas da carcinogênese precoce. Essas alteraçöes podem ser expressäo de um processo de "campo de cancerizaçäo". A avaliçäo histopatológica dessas alteraçöes é difícil, subjetiva e nem sempre é uma indicaçäo confiável da progressäo para carcinoma invasivo. O objetivo deste trabalho foi estudar a expressäo do p53, PCNA, Ki-67 e NORs no epitélio de revestimento da mucosa próximo a 26 carcinomas epidermóides de boca, verificando a correlaçäo desses marcadores com grau de atipia epitelial e a correlaçäo entre os mesmos. Foi utilizada a técnica imuno-histoquímica e histoquímica em tecidos rotineiramente fixados e processados, empregando-se anticorpos anti-p53, anti-Ki-67 e a coloraçäo pela prata coloidal, AgNOR. Nós näo encontramos correlaçäo de nenhum dos marcadores com o grau de atipia epitelial. Correlaçäo foi observada apenas entre o PCNA e Ki-67. Nós sugerimos que as alteraçöes relacionadas a estes marcadores podem preceder as alteraçöes morfológicas no epitélio adjacente aos carcinomas epidermóides de boca, e que o estudo dos mesmos podem ajudar na decisäo sobre o manejamento da lesäo

Utility of silver-colloidal staining method in the diagnosis of medulloblastoma.

Histopathological features of medulloblastomas are usually distinctive. However in rare instances, a distinction between the neoplastic cells of medulloblastoma and the neurones in the cerebellar internal granular layer becomes difficult at light microscopic level. In order to distinguish presence of argyrophilic Nucleolar Organizer Regions (Ag-NORs) was analysed in the paraffin sections of medulloblastoma as well as in the cerebellar internal granular layer. The neoplastic cells in medulloblastoma contained a mean 4.78 Ag-NOR per nucleus while the neurones in cerebellar internal granular layer contained a mean Ag-NOR 0.90 +/- 0.12 per nucleus. Compound Ag-NORs were present in the cells of medulloblastoma while they were absent in the neurones of cerebellar internal granular layer. The results of this study indicate that Ag-NOR technique may be useful in an uncommon situation, where a histopathological distinction between cells of medulloblastoma and neurones in the cerebellar internal granular layer becomes difficult.

Nuclear ultrastructure in low and high grade Non-Hodgkin's Lymphomas

Transmission electron microscopy was used to study the ultrastructure of nucleoli in 3 high and 3 low grade non-Hodgkin's lymphomas. Nucleoli with a single large fibrillar center were predominantly seen in the low grade group. While, the majority of nucleoli in high grade lesions contained several small fibrillar centers of approximately equal size. A third type of nucleolus appearance was identified with a large central fibrillar center surrounded by numerous small "satellite" fibrillar center. This nucleolus configuration was the least common but was more often seen in low grade than in high grade lymphomas. These results showed that fibrillar center size and morphology correlates with grade of non-Hodgkin's lymphoma and may reflect differences in ribosomal deoxyribonucleic acid transcription

AgNORs in tumoral pathology. Review of literature and observations on the technic and reaction in normal oral epithelium.

Ten normal oral epithelium were studied for AgNOR demonstration. The AgNOR count decreased, size increased from bottom to top. The areas of basal cell hyperplasia showed higher count more scatter and smaller AgNORs. The AgNORs thus appear to be reflective of the replicatory capacity of the tissue.

Nucleolar organizer regions in smooth muscle and breast tumours.

Paraffin sections of formalin fixed tissues, obtained from patients with smooth muscle and breast tumours, were studied by the silver staining technique to quantitate the Nucleolar Organizer Regions (AgNORs) per nucleus and to assess its significance as an independent variable in predicting the behaviour of these neoplasms. Five benign and five malignant tumours of smooth muscle along with ten benign and ten malignant epithelial tumours of breast were studied. Normal myometrium and breast tissue served as controls. Control, benign and malignant tumours of smooth muscle showed mean AgNOR scores of 2.68, 3.89 and 12.50 per nucleus respectively. Control, benign and malignant tumours of breast showed mean AgNOR scores of 1.75, 7.45 and 12.72 per nucleus respectively. These results suggest that quantitative analysis of AgNORs per nucleus is capable of differentiating benign from malignant lesions of smooth muscle and breast.

Nucleolar organizer region heteromorphism associated with trisomy-21: a risk factor for non-disjunction?

An unusual nucleolar organizer region (double NOR) on chromosome 13 was observed in a Down syndrome child [47, XY, +21, dNOR(13)]. The variant chromosome was inherited from the mother [46, XX, dNOR(13)]. The extra chromosome 21 in the proband was maternal origin. The frequency of NOR chromosome association showed relatively high frequency in the mother and proband as compared to the controls. The result suggest that chromosome variants involving extra copies of NOR may indeed be involved in the meiotic nondisjunction of chromosome-21.