Nucleolar organiser regions in pathology

Analysis of Argyrophilic Nucleolar Organizer Regions (AgNORs) in Acute Leukemia in Adults

The evaluation of argyrophilic nucleolar organizer regions (AgNORs) uses a simple method used in research into neoplasm. Bone marrow aspirates from 70 patients with acute leukemia underwent morphological, immunophenotypic, and genetic assessment and were stained with silver nitrate. In leukemic cells, the mean AgNORs number, mean AgNORs area, and mean AgNOR-area-to-nucleus-area ratio were calculated in patients with acute myeloid leukemia (AML), patients with acute lymphoblastic leukemia (ALL), and selected risk groups. A higher value of all measured AgNOR parameters was observed in patients with AML compared to the ALL group. In AML patients, a higher mean AgNOR area was found in the ELN3 cytogenetic group compared to the ELN2 cytogenetic group. A higher value of the mean AgNOR count was observed in patients with white blood cells (WBCs) > 12 × 109/L than in the group with WBCs ≤ 12 × 109/L, as well as in patients with >20% blasts in peripheral blood (PB) than in patients with ≤20% blasts in PB. In the ALL group, a higher mean AgNOR-area-to-nucleus-area ratio was found in group with the presence of Philadelphia chromosome Ph(+) than without the Philadelphia chromosome Ph(−). AgNOR parameter analysis is a valuable method for differentiation of AML and ALL in adults.

Adaptation of the agyrophil technique for nucleolar organizer regions to canine peripheral blood smears

Nucleolar organizer regions (NORs) are chromosomal segments which are selectively stained by silver methods and evaluated as agyrophilic nucleolar organizer regions (AgNORs). The evaluation of AgNORs provides an insight into the level of cellular proliferation. This technique has extensively and sparsely been used in human and veterinary histopathology respectively. However, two major drawbacks have been irreproducible results and excessive staining precipitates. This study seeks to adapt the technique to canine peripheral blood smears in order to establish a routine staining protocol. Standardized volumes and concentrations of silver nitrate, gelatin, and formic acid were applied to smears at different temperatures for varying lengths of time. The technique was applied to unfixed and fixed smears. In some cases, a reducing agent (1% potassium iodide) was applied. It was shown that the optimum staining protocol was achieved by applying standardized solutions to a fixed smear at 46°C for 50 minutes. It is concluded that the staining protocol outlined in this study is practicable, and produces excellent and reproducible results that would enhance evaluation of AgNORs in canine peripheral blood cells.

Quantitative analysis of Argyrophilic Nucleolar organizer regions in odontogenic cysts and tumor - A comparative study

Background

The nucleolar organizer region (NOR) is by definition part of a chromosome, and nucleolus is a structure containing this chromosomal part and in addition the material which accumulate around the NOR, mostly rRNAs and their precursors as well as specific ribosomal proteins. Argyrophilic Nucleolar organizing region (AgNOR) are silver binding NORs often used to study cell proliferation in various types of tumors.

Aim

Quantitative assessment of Argyrophilic Nucleolar organizing region count and its comparison among dentigerous cyst, keratocystic odontogenic tumor and ameloblastoma.

Material and method

Forty-five histologically confirmed cases, 15 cases each of keratocystic odontogenic tumor, dentigerous cysts and ameloblastomas were examined for Argyrophilic Nucleolar organizing region. The sections were obtained and Argyrophilic Nucleolar organizer regions staining was done for comparing the proliferative capacity among these lesions.

Result

Post hoc analysis for inter-group comparison and one way ANOVA were done in all three groups in this study. P < 0.001 was considered significant. The results of AgNOR counts were higher in KCOTs as compared to ameloblastoma and least in dentigerous cysts. The mean AgNOR counts between the study groups were compared using one way ANOVA test and the differences were found to be significant (P < 0.001).

Conclusion

AgNOR counts were significantly higher in KCOT and ameloblastoma as compared to dentigerous cyst suggesting that these lesions have a higher proliferative capacity than dentigerous cyst. The finding of a significantly higher AgNOR counts in KCOT as compared to ameloblastoma represent a difference in proliferative activity and greater growth potential between these two lesions.

Estimation of silver nucleolar organizer regions in oral lichen planus, oral lichenoid reactions and oral lichenoid dysplasia

Aims and Objective:

(1) To study the clinical and histological features of oral lichen planus, oral lichenoid reaction (OLR) and oral lichenoid dysplasia (OLD). (2) To estimate and compare the silver nucleolar organizer regions in OLR and OLD.

Materials and Methods:

A total of 40 biopsies were studied; sections were divided as study group, which consists of OLP, OLR and OLD each of 10 cases and 10 biopsies of normal oral mucosa as control group. Sections were stained by silver staining technique and total number of silver stained nucleolar organizer regions (AgNORs) were counted in nucleoli of 100 cells in each section under x100 objective (oil immersion).

Results:

Our study revealed that the difference between the (AgNOR) count of OLP (2.272 ± 0.09) and OLR (2.27 ± 0.073) is not statistically significant (P = 0.81). The mean AgNOR count of OLD (2.388 ± 0.043) compared to that of OLP (2.272 ± 0.09) and OLR (2.27 ± 0.073) showed an increase and it is statistically highly significant (P = 0.002 and P = 0.003, respectively).

Conclusion:

AgNOR count is an objective test, which has stronger biological basis for diagnosing epithelial dysplasia. It is easy to perform, inexpensive and is performed on biopsied specimen. However, this technique cannot differentiate OLP and OLR, as there is no much difference in the proliferative activity of cells in these two lesions. It is reasonable to suggest that all biopsy tissues from lichenoid lesions where dysplastic features are observed in routine histopathological sections should be additionally stained by silver technique to ascertain dysplastic status of the lesion.

Clinical Significance:

This is an improved diagnostic parameter, which will help pathologists to formulate more definitive final histopathological diagnosis and will in turn facilitate the formulation of patient treatment and follow-up care by clinicians.

Prognostic potential of AgNORs in oral submucous fibrosis

Aim and Objective:

The role of prognosis cannot be stressed enough, especially when it comes to potentially malignant lesions. The argyrophilic nucleolar organizer regions (AgNORs), which is simple and cost-effective has been used in diagnostic and prognostic pathologies. This study seeks to identify the nucleolar organizer regions (NORs) in oral submucous fibrosis (OSMF), to correlate the AgNOR count with the histologic grade of OSMF, and to evaluate the prognostic potential of AgNOR.

Materials and Methods:

The sample size consisted of archival paraffin blocks of 35 cases of varying grades of OSMF and 10 cases of squamous cell carcinoma. Normal mucosa samples served as controls for the study. AgNOR staining in accordance with the method of Smith and Crocker was performed and Student's t-test was used for statistical analysis.

Results:

The results showed an increase in AgNOR counts with corresponding grades of OSMF, the count being least in normal mucosa and also an increase in AgNOR count with corresponding decrease in differentiation of oral squamous cell carcinoma.

Conclusion:

AgNOR staining is a rapid and inexpensive procedure representing cellular proliferation that can be used to assess the nature of the lesion and therefore, the prognosis.

Evaluation of the efficacy of AgNOR as a proliferative marker in oral leukoplakia: A morphometric analysis

Background:

Silver stainable nucleolar organizer regions (AgNORs) are replicatory markers which may have a place in objectively characterizing dysplasia.

Materials and Methods:

A study of various morphometric parameters related to AgNORs was performed in basal and parabasal layers of normal human oral epithelium, nondysplastic leukoplakia, and dysplastic leukoplakia employing photomicrographs of silver stained paraffin embedded sections using image analysis, to assess the usefulness of these parameters in distinguishing dysplastic leukoplakia from nondysplastic oral leukoplakia.

Results:

Out of various mean AgNOR related parameters, AgNOR count, area, perimeter, and proportion were found to be higher in dysplastic leukoplakia as compared to nondysplastic leukoplakia. On statistical analysis, AgNOR count showed statistically significant differentiation between dysplastic and nondysplastic leukoplakia. While other parameters can distinguish normal oral epithelium from dysplastic and nondysplastic leukoplakia.

Conclusion:

To conclude, the AgNOR count is the most appropriate marker to differentiate between dysplastic and nondysplastic leukoplakia.

Early detection of oral cancer: PAP and AgNOR staining in brush biopsies

Aim:

The aim of this study was to determine the diagnostic accuracy of routine Papanicolaou stain (PAP) and Silver stained Nucleolar Organizer Regions (AgNOR) staining in brush biopsies taken from suspected oral lesions for early detection of oral cancer.

Materials and Methods:

Brush biopsies were collected from macroscopically suspicious lesions of the oral cavity of 34 patients and 10 normal-aged and sex-matched controls. The numbers of AgNORs were counted in 100 squamous epithelial cell nuclei per slide after silver staining of the smears (Ploton’s one-step method).

Results:

Sensitivity and specificity of PAP analysis in the oral smears for detection of oral cancer and normal cells was 91.176% and 100%. The positive and negative prediction values were 100% and 76.92%, respectively. Sensitivity and specificity of AgNOR analysis in the oral smears for detection of oral cancer and normal cells was 100%. The positive and negative prediction values were 100% each.

Conclusion:

Based on the above facts, we conclude that brush biopsy in conjunction with AgNOR staining is an easily practicable, non-invasive, safe and accurate screening method for the detection of macroscopically suspicious oral cancerous lesions. Because of its simple technique and high reliability for cellular proliferation, AgNOR staining in brush smears can be used as an adjunct to other routine cytological diagnoses for the early detection of oral cancer. However, further investigations with more number of study samples will be needed to establish this correlation beyond doubt.

Trends and Challenges in Pathology Practice: Choices and necessities

The way we provide healthcare is influenced by ongoing experiences, increased knowledge, new discoveries and scientific as well as technological advances. The rapid pace of important developments that have taken place in recent years have significantly influenced our choices of the ways we provide our health service. Like other medical specialties, pathology and its practice have had to respond to the rising needs and challenges within the health service in general and those facing the speciality in particular. This article addresses some of the challenges, particularly those which are unique to pathology. It discusses the choices that are available to different pathology departments depending on their individual circumstances.

Expression of Fas and Fas-ligand and analysis of argyrophilic nucleolar organizer regions in squamous cell carcinoma: relationships with tumor stage and grade, and apoptosis

The aim of this study was to investigate whether levels of Fas and Fas-ligand (Fas-L) expression in oral and oropharyngeal squamous cell carcinomas (SCCs) are associated with tumor stage and grade, and to assess whether parameters related to argyrophilic nucleolar organizer regions (AgNORs) correlate with apoptosis in SCC cells and adjacent normal epithelium. Fifty-two specimens taken from the tumoral and neighboring normal tissues of 26 patients with oral and oropharyngeal SCC were analyzed for Fas/Fas-L expression, and 24 specimens from 12 patients for AgNOR parameters. Seventeen (65%) of the tumors were Fas and/or Fas-L-positive (by immunohistochemistry). A significant positive correlation was found between Fas/Fas-L expression and clinical tumor stage (P<0.01). Mean AgNOR number per nucleus, AgNOR size and the percentage area of each nucleus occupied by AgNORs (percent of nuclear area) were significantly increased in the SCC cells (4.49+/-1.28, 4.48+/-1.42, 5.56+/-1.22, respectively) when compared with the control neighboring squamous epithelial cells (2.58+/-0.61, 1.64+/-0.59 and 4.35+/-0.62%, respectively) (P<0.01). A significant positive correlation was found between the AgNOR parameters and Fas/Fas-L expression as apoptotic markers in the tumoral cells of SCC (P<0.05). There was also a significant positive correlation between the AgNOR parameters and the grading of tumors (P<0.05). In conclusion, AgNOR count was a strong proliferation marker in patients with SCC, and Fas and Fas-L staining was useful in tumor grading.

The importance of nucleolar organizer regions in pediatric acute lymphoblastic leukemia

The silver-staining of the nucleolar organizer regions (AgNORs) was performed in patients with acute lymphoblastic leukemia (ALL) to verify the role of cell proliferation in predicting complete remission and survival. Bone-marrow aspiration smears of 20 pediatric cases with ALL, were stained with argyrophilic method during the diagnosis, remission, and 3rd, 6th, 9th, and 12th months after remission. The mean NORs count (NORsc) and the mean of (nucleolar organizer regions surface/total nuclear surface x 100) value (NORss/TNs) for each case were calculated. At diagnosis, the NORsc and NORss/TNs value for the whole series were 3.30+/-0.86 and 4.77+/-1.15, respectively. In complete remission, NORsc and NORss/TNs values were 1.23+/-0.20 and 3.45+/-0.87, respectively, and the differences were statistically highly significant (p < .001). The most important parameters of prognostic factors that effect diagnosis NORss/TNs and NORsc values were found to be FAB morphology and leukocyte count according to the multivariant analysis test. AgNORs analysis is a suitable method to assess cell proliferation in bone marrow aspirate and can predict complete remission, remission duration, and survival in pediatric ALL patients.

Modulation of carcinogenic response and antioxidant enzymes of rats administered with 1,2-dimethylhydrazine by Picroliv

The effect of Picroliv treatment on the carcinogenic response and, hepatic and renal antioxidant enzymes of rats administered with 1,2-dimethylhydrazine hydrochloride (DMH) was studied in male Sprague-Dawley rats. DMH-induced hepatic carcinogenic response and necrosis were inhibited by oral administration of Picroliv (40 and 200 mg/kg). Liver gamma-glutamyl transpeptidase, which was elevated to 0.41 +/- 0.06 nmol/mg protein by DMH administration was found to be reduced to 0.22 +/- 0.04 and 0.18 +/- 0.03 nmol/mg protein by Picroliv treatment 40 and 200 mg/kg, respectively. Elevated number of Argyrophilic Nucleolar Organizer Region dots and clusters, an index of proliferation, of DMH treated rat liver was reduced by Picroliv treatment. DMH-induced depletion of hepatic and renal antioxidant enzymes such as catalase and superoxide dismutase levels were restored to normal by Picroliv treatment. Picroliv treatment reduced the DMH-induced elevation of lipidperoxidation in liver, kidney and serum. Elevated levels of serum total bilirubin by DMH administration was reduced by Picroliv treatment. Depleted renal glutathione S-transferase and hepatic glutathione levels after DMH administered rats were found to be significantly increased by Picroliv treatment. Histological analysis of the DMH administered rat liver showed hepatic cell necrosis, coalescent nodular areas and cystic hyperplasia of the bile ducts with inflammation. Picroliv treated liver resembled normal liver except the presence of a few degenerating cells. Renal anatomy was not altered by DMH administration.

Nucleolar organizer regions (NORs) evaluation of lingual salivary glands of chronic alcoholics

BACKGROUND

Chronic alcoholism has been associated with structural and physiological changes in salivary glands. Studies on a variety of pathologies have suggested that variation in number of nucleolar organizer regions (NORs) reveals conditions of cellular activity. The aim of this work was to examine, through the AgNOR technique, changes in number and size of NORs in lingual salivary glands of chronic alcoholics.

METHODS

Samples of mucous and serous lingual salivary glands were obtained from tongues from autopsies of individuals whose cause of death was hepatic alcoholic cirrhosis. Lingual organs from individuals whose cause of death was accidental were used as controls. Number and size of the AgNORs and nuclear area, in ductal and acinar cells, were evaluated through a digital image analyzer.

RESULTS

Statistical analysis revealed differences (P < or = 0.05) in number of AgNORs in mucous acini and ductal cells. Also, we observed changes in the area of the NORs.

CONCLUSION

These results suggest that in alcoholics the activity of glandular cells, mainly in ductal epithelium, could be affected, modifying synthesis, transport and salivary secretions.

Evaluation of argyrophilic nucleolar organiser regions (AgNORs) in multiple myeloma

AIM

To investigate the prognostic value of argyrophylic nucleolar organiser regions (AgNORs) in multiple myeloma.

METHODS

Bone marrow aspirates from 55 newly diagnosed patients with multiple myeloma were stained with the one step AgNO3 technique. The mean number of AgNORs in each plasma cell nucleus (AgNOR count) was tested for a possible correlation with other clinical and laboratory variables at presentation (clinical stage, substage, heavy and light chain isotype, haemoglobin concentration, platelet count, marrow infiltration rate, degree of skeletal lesions, M protein concentration, plasma cell morphology, and serum concentrations of calcium, albumin, lactate dehydrogenase, C reactive protein, and beta 2 microglobulin) and with outcome (response to first line treatment, first remission duration, and overall survival).

RESULTS

A significant association between mean (SD) AgNOR count was found only for clinical stage (stage I, 3.09 (1.19); stage II, 3.80 (1.53); stage III, 5.28 (1.79); p < 0.005) and, from all stage determinants, only for M protein concentration (high, 5.92 (1.80); low, 4.01 (1.92); p < 0.001). There was a linear relation between AgNOR count and serum M protein concentration for patients with both IgG (r = 0.450; p < 0.01) and IgA (r = 0.768; p < 0.002) producing multiple myeloma.

CONCLUSIONS

Unlike previous investigations, no clear prognostic value for the AgNOR count was found in multiple myeloma. Instead, the results indicate that the AgNOR count might be an index for M protein synthesis rate. This is consistent with other findings in tissues with low proliferative potential and high protein synthetic activity, and calls for a cautious interpretation of AgNORs in malignancies with similar features.

Prognostic relevance of AgNORs in tumor pathology

The importance of the analysis of the silver-stained nucleolar organizer regions (AgNORs) for prognostic purposes in tumor pathology has been reviewed. Current available data from the literature demonstrate that the evaluation of the quantity of interphase AgNORs is an independent prognostic factor in several types of human tumors. Results of our investigations indicate that AgNORs are the most powerful variable predicting survival in patients with pharyngeal carcinoma, multiple myeloma, male breast and prostate carcinoma. The combination of AgNOR counts and histologic pattern allows the stratification of patients with multiple myeloma, pharyngeal and prostate carcinoma into low- and high-risk groups, which could benefit from different therapy. Moreover, AgNOR analysis predicts response to treatment in adult patients with acute myelogenous leukemia, and appears as an independent prognostic factor in a prospective study on renal cell carcinoma. Therefore, AgNOR analysis is a really important prognostic factor for several human neoplasias. The experimental and theoretical justifications for AgNORs as a prognostic factor are also reviewed, in particular the strict correlation between AgNOR quantity and tumor cell doubling time. Lastly, the lack of prognostic significance of AgNOR analysis in some circumstances is critically discussed.

PCNA/AgNOR and Ki-67/AgNOR double staining in oral squamous cell carcinoma

This study was performed on oral squamous cell carcinomas (OSCC) in order to investigate the relation between the number of interphase silver-stained nucleolar organizer regions (AgNORs) and the immunolabeling of proliferation-associated markers, using antibodies to Ki-67 and proliferating cell nuclear antigen (PCNA). Fifteen consecutive cases of oral squamous cell carcinoma were used and a double staining technique was performed in order to quantify the number of NORs in PCNA-positive and -negative cells as well as in Ki-67-positive and -negative cells. Our results showed a higher mean number of AgNORs in PCNA- and Ki-67-positive cells than in PCNA- and Ki-67-negative cells. We concluded that there is an association between cell proliferation and AgNOR score in OSCC.

Standardized in situ AgNOR analysis in breast pathology: diagnostic and cell kinetic implications

The aim of the present study was to assess the diagnostic value of the recently standardized morphometric analysis of silver-stained nucleolar organizer region-associated proteins (AgNORs) [30] in a variety of 155 routinely processed benign and malignant breast lesions. 5 normal breast samples, 21 adenoses, 20 ductal hyperplasias, 10 atypical ductal hyperplasias, 20 in situ and 43 invasive ductal carcinomas, 10 in situ and 26 invasive lobular carcinomas were investigated. A statistically highly significant difference was found between normal/ordinary hyperplastic and neoplastic breast lesions with all 4 consensus AgNOR parameters (mean area, mean number, CV of area, CV of number) evaluated. AgNOR quantity was significantly related to histological grade of both in situ and invasive carcinomas. However, variable overlap was found between AgNOR values in different diagnostic groups. We conclude that standardized AgNOR analysis is a prerequisite for objective and reproductible AgNOR assessment in archival tissues. Despite its limited diagnostic utility for individual breast lesions, standardized AgNOR analysis bears a significant potential for characterizing cell kinetic and metabolical activity of breast lesions. This may give insight into the biological background of breast carcinogenesis, differentiation and tumor progression and may also underlie the independent prognostic value of AgNORs in breast cancer.

Argyrophilic nucleolar organizer regions in cells of thymoma and thymic carcinoma: correlation with DNA ploidy and clinicopathologic characteristics

STUDY OBJECTIVES

To evaluate the usefulness of argyrophilic nucleolar organizer region (AgNOR) counting and flow cytometric DNA analysis in the differential diagnosis of thymoma and thymic carcinoma, as well as in the differences among various stages and histologic subtypes of these tumors.

DESIGN AND INTERVENTIONS

Paraffin-embedded blocks of 64 thymic epithelial tumors (20 noninvasive thymomas, 34 invasive thymomas, and 10 thymic carcinomas) were studied by AgNOR counting and flow cytometric DNA analysis. The thymomas were histologically classified as medullary, cortical, or mixed subtype.

MEASUREMENTS AND RESULTS

Invasive thymomas had more AgNORs (-/+ SD) than noninvasive thymomas (7.93+/-2.90 vs 5.97+/-1.77; p < 0.01). The number of AgNORs of thymoma increased progressively with advances in stage (p < 0.01). Cortical thymomas had the highest number of AgNORs among the three subtypes (p < 0.05). Patients with thymoma who presented with myasthenia gravis also had a higher number of AgNORs (8.30+/-3.12 vs 6.50+/-2.03; p < 0.01). The AgNOR number did not correlate with the DNA ploidy of all specimens.

CONCLUSIONS

AgNOR counting is useful in differentiating between invasive and noninvasive thymomas, and in predicting the stage of thymomas. A greater number of AgNORs was observed in patients with cortical thymoma and in those who presented with myasthenia gravis.

The silver reaction of nucleolar proteins in the main structural compartments of ring-shaped nucleoli in smear preparations

The present study was undertaken to provide more information on the conditions which result in preferential silver staining of the main nucleolar structural compartments using silver stainable proteins as their markers at the light microscopic level. For this study the mostly used method in cytology and pathology in which the nucleolar silver-positive structures are "developed" with the colloidal developer (Howell and Black, 1980; Ploton et al., 1986) was selected as silver reaction. Ring-shaped nucleoli of mature human lymphocytes represent a convenient model for such a study because they consist of one large fibrillar center, adjacent nucleolar regions with dense fibrillar components and the nucleolar peripheral shell with dense granular components. All these nucleolar compartments are known to possess characteristic silver stainable proteins. The results demonstrated that proteins of the fibrillar center and possibly adjacent nucleolar regions reacted preferentially with silver after a relatively long fixation with formaldehyde or methanol in unwashed specimens before the silver reaction. In contrast, the preferential staining of proteins in the nucleolar peripheral shell with silver was achieved after the fixation with acidified methanol or ethanol as well as after short fixation with formaldehyde vapors. In addition, the commonly used fixation before the silver reaction are not necessary and may be omitted for the visualization of all silver stainable proteins present in the fibrillar center as well as in the adjacent nucleolar regions and the nucleolar peripheral shell. In addition, similar results were achieved for the simultaneous visualization of proteins in the fibrillar center and nucleolar peripheral shell after fixation with ethanol.

Colchicine therapy for hepatic murine schistosomal fibrosis: image analysis and serological study

Colchicine in a dose of 200 micrograms kg body weight/day (5 days/week) was administered to groups of Schistosoma mansoni infected mice 12 weeks post infection, either alone or following previous praziquantel therapy at the 8th week of infection. Certain groups received colchicine for 6 weeks and others received it for 10 weeks. Colchicine alone did not significantly change the light microscopic appearance of schistosomal liver fibrosis, or hepatic collagen content estimated histomorphometrically, and did not reduce the elevated IL-2 serum level. Colchicine induced hepatic injury consisted of intense inflammatory reaction in granuloma and portal tracts, hepatocytic degeneration, and elevation of serum AST and ALT levels. Colchicine seemed to postpone granulomatous reaction healing and collagen deposition rather than inhibiting collagen formation or degrading it. Colchicine inhibited proliferation of hepatocytes of infected mice by expanding G2-M phases of cell cycle, thus reduced Ag NOR count and raised cell ploidy and cyclic AMP serum level. Subsidence of schistosomal infection by praziquantel prior to colchicine therapy greatly reduced inflammatory cellular reaction, significantly diminished hepatic collagen deposition and serum IL-2 level, minimized the elevated nuclear ploidy and cyclic AMP serum level that followed colchicine therapy when administered alone.

Characterization of topotecan-mediated redistribution of DNA topoisomerase I by digital imaging microscopy

Topographical image measures have been used to characterize the subnuclear distribution of DNA topoisomerase I in human tumor cell lines. This topographical analysis allowed a mathematical description of staining patterns to be produced that did not depend on subjective grading. The redistribution of topoisomerase I in response to increasing concentrations of topotecan was then monitored by this method. The cell lines were stained for topoisomerase I by indirect immunofluorescence methods. Digital imaging microscopy and image analysis were used to extract the nucleus from each cell, and nine parameters describing the topography of the distribution of topoisomerase I within the nucleus were computed for each. Use of multivariate analysis of variance enabled this nine-parameter set to be reduced to a single canonical variable, representing 60-90% of the observed internuclear variance. Plotting the canonical variable vs drug concentration resulted in dose-response curves that could be fitted well by a simple Emax model. From these curve fits, EC50 and Emax values for drug-induced redistribution of topoisomerase I were determined. Our results indicate that neither the maximum extent of topoisomerase I redistribution (Emax) nor the EC50 for drug-induced redistribution correlated well with the growth inhibition produced by continuous exposure to topotecan in these cell lines. However, the EC50 determined for the 1-h high-concentration exposure did reflect the growth inhibition produced in cells exposed to the drug for 1 h. The methodology described may also be generally applied to any antigen of interest.

Evaluation of argyrophilic nucleolar organizer regions (AgNORs) in oral carcinomas in relation to human papillomavirus infection and cytokinetics

The numbers of argyrophilic nucleolar organizer regions (AgNORs) were quantified in oral carcinomas (n = 39) with or without human papillomavirus (HPV) infection. The AgNOR counts of the HPV-positive samples (7.15 +/- 2.13) were not significantly (P = 0.09) higher than those of the HPV-negative ones (6.16 +/- 1.89). Furthermore, the lesions infected with multiple HPV types had greater counts than those with HPV type 16/18 infection alone. Significant differences were observed between the mean counts of the poorly (10.50 +/- 0.54), moderately (7.31 +/- 1.07) and well- (5.12 +/- 0.85) differentiated carcinomas. The mean AgNOR numbers in the oral carcinomas at TNM stages III/IV were found to be significantly (P < 0.01) higher than the numbers in corresponding stage II lesions. Cytokinetics of the lesions assessed by the bromodeoxyuridine (Brdu) labelling index (LI%) showed a linear correlation (r = 0.91; P < 0.0001) with their respective mean AgNOR counts.

Proliferative activity of esophageal carcinomas and their lymph node metastases: comparison using argyrophilic nucleolar organizer region staining

BACKGROUND

Many reports have concluded that quantification of the argyrophilic nucleolar organizer regions (AgNORs) measures proliferative activity and is a prognostic indicator in malignant disease. This retrospective study set out to evaluate the relationship between the AgNORs of the primary tumors and those of lymph node metastases in esophageal carcinoma.

METHODS

Using a one-step silver staining technique, AgNORs were counted in surgical specimens from 54 patients with squamous cell carcinomas.

RESULTS

The AgNOR scores of the lymph nodes metastases were significantly lower than those of the primary tumor (P = 0.0001). In 53 of 54 cases (98%), the AgNOR scores in the nodal metastases were lower than those of the primary tumor. The survival of 22 patients with AgNOR scores > or =4.0 for the primary tumor was significantly less than that of 32 patients with AgNOR scores <4.0 for the primary tumor (P = 0.0014).

CONCLUSIONS

The AgNOR score of the lymph node metastases had no prognostic significance. The AgNOR score of esophageal primary cancer reflects the prognosis of patients. Scores for lymph node metastases were lower and did not reflect prognosis. The lower score in the lymph node metastases may result from the antitumor activity of macrophages in the lymph nodes.

Canine neuroendocrine tumors of the pancreas: a study using image analysis techniques for the discrimination of metastatic versus nonmetastatic tumors

Canine pancreatic neuroendocrine tumors were studied using different image analysis techniques (nuclear image histometry, analysis of argyrophilic proteins of nucleolar organizer regions, determination of the mouse anti-Ki 67 antigen proliferation index, and DNA densitometry) to correlate their biological behavior with objective phenotypic markers. The methods were compared to determine the best method for distinguishing between metastatic and nonmetastatic tumors. Discrimination between the two types of tumor was possible using nuclear image histometry in combination with morphometric analysis of argyrophilic proteins of nucleolar organizer regions. In contrast, the mouse anti-Ki 67 antigen proliferation index, DNA measurement, and immunohistochemical parameters revealed no significant difference between the two types of tumors.

Silver-stained nucleolar organizer regions in adenocarcinoma of the cervix--a light and electron microscopic study

An increase in the number of Ag-NORs has been described as a possible marker for histopathological cancer diagnosis. The ultrastructural correlation of the reaction, however, has never been elucidated. In tissue samples of the endocervix of the uterus, we compared the ultrastructural configuration of Ag-NORs with the number of Ag-NORs dots. Light microscopic studies showed that the number of Ag-NORs in adenocarcinoma cells significantly increased, but the relation to the bromodeoxyuridine labeling index was not determined. By electron microscopy, Ag-NORs were only observed in the nucleoli and the nuclear bodies of nuclei. Ag-NORs were localized on all components of the nucleolar structure, but the dense fibrillar component was the predominant site in several cases. The nuclear bodies were exclusively found in adenocarcinoma cells and were argyrophilic. A spotted distribution of Ag-NORs was often found in the nucleoli of adenocarcinoma cells that showed an increased Ag-NOR count. The number of Ag-NORs was attributed not only to the number of nucleoli and nuclear bodies in a nucleus but also to the speckled distribution of silver deposits in a nucleolus. These results imply that the Ag-NOR count is a more definitive indicator of a hyperactive state of the cells than the combined number of nucleoli and nuclear bodies in adenocarcinoma of the uterine cervix.

Argyrophilic nuclear organizer regions (AgNORs) in pediatric acute lymphoblastic leukemia

Nuclear organizer regions (NORs) code for ribosomal RNA and are associated with non-histone nucleoproteins which can be identified by silver staining (AgNORs). AgNORs have been correlated to proliferative activity of tumors and hence may be prognosis-related. The present study evaluates the possible prognostic importance of the AgNORs in tumor cells of patients with pediatric acute lymphoblastic leukemia (ALL). A significant increase in AgNOR counts was observed in ALL patients as compared to normal controls. Further, a significant positive correlation was observed between AgNOR counts and total WBC count at diagnosis. A negative correlation was also observed between AgNOR counts and age of the patients. Logistic regression analysis revealed further correlation between AgNOR counts and disease with an odds ratio of 1.29 (P = 0.03) as compared to normal controls. These results therefore suggest that AgNOR counts may be significant in the evaluation of pediatric ALL.

Heterogeneity of expression of immunohistochemical tumour markers in testicular carcinoma in situ: pathogenetic relevance

Testicular carcinoma in situ (CIS) is the precursor of germ cell tumours in adults, except for spermatocytic seminoma. The mechanism of the progression from premalignant CIS to invasive and overt tumours is largely unknown. There are currently two main hypotheses: one is that CIS can progress directly to either seminoma or nonseminoma; according to the other, seminoma is the intermediate stage between CIS and nonseminoma. CIS cells express several tumour antigens, such as placental-like alkaline phosphatase (PLAP), TRA-1-60, or the c-kit proto-oncogene protein product (Kit), which are present to varying degrees in the invasive germ cell tumours. In this study, CIS cells adjacent to either pure or combined tumours were examined by double immunohistochemical staining for simultaneous expression of TRA-1-60 (typical for embryonal carcinoma) and either Kit (expressed by seminomas) or PLAP (found mainly in seminomas, but also in some cases of nonseminoma). Marked differences in the expression of these antigens were found among CIS cells, especially those adjacent to mixed tumours. We conclude that CIS is a phenotypically heterogeneous lesion, and that the CIS cells, despite identical morphology and close spatial localization, may be in different stages of progression. The results lend support to the hypothesis that CIS can progress directly to both seminomatous and nonseminomatous tumours.

A new monoclonal antibody for specific immunocytochemical staining of nucleoli

We have isolated a hybridoma cell line (clone 1E10) producing a monoclonal antibody which specifically recognizes nucleoli. The antibody (IgM, k isotype) was found to react in a nucleolar pattern with a variety of cell types. Specific staining was only obtained on cryostat sections of unfixed tissues. Paraffin embedding destroyed the epitope. Tissue specificity or species specificity was not observed. Nucleoli in neoplastic cells were highly reactive, presumably due to the larger size of nucleoli in these cells. Immunoelectron-microscopy (using a pre-embedding as well as a post-embedding technique) confirmed the specific nucleolar localization of the immunoreactivity. Immunoreactivity was confined to the granular component of the nucleolus. The intensity of the immunoreactivity increased after cell or tissue pretreatment with DNase, pronase or trypsin, indicating that the target epitope is not DNA or a protein. On Western blots of immunoreactive cells no specific signal was obtained, which supports the non-protein nature of the epitope. Acid hydrolysis and RNase digestion abolished the immunoreactivity. Parallel staining experiments with methylgreen pyronin and acridin orange confirmed the RNA nature of the epitope. In spot blots, immunoreactivity was not found with tRNA or mRNA. These observations indicate that 1E10 recognizes a conformational RNA epitope which occurs only in the nucleolus.

In vitro effect of ciprofloxacin on HT-29 human colon carcinoma cell line: assessment of cell proliferation by thymidine uptake and silver nucleolar organizer regions (AgNOR) histomorphometry

In an in vitro study, the effect of ciprofloxacin was examined on proliferation of HT-29 human colon carcinoma cell line. Cell proliferation was measured by 3H-thymidine uptake and silver nucleolar organizer region (AgNOR) histomorphometry. A significant increase in [3H]thymidine incorporation (p < 0.05) parallel with a significant increase in the mean AgNOR clusters/cells (p < 0.01) was noted after 5 days of cell exposure to ciprofloxacin. It is suggested that the assessment of AgNOR variables is useful in examination of quinolone effect on HT-29 human colon carcinoma cell proliferation.

A rapid silver staining and destaining technique for the nucleolus organizer region

Silver staining of nucleolar organizing regions (NOR) is common, but a standard protocol is lacking. A modification of a rapid silver nitrate staining technique for NORs is presented here. Advantages of the modified technique include reliability, speed, cost and the fact that it can be carried out in the light.

Nucleolar organizer regions in hepatocellular carcinoma related to the cell cycle, cell proliferation and histologic grade

In order to clarify factors which relate to AgNOR in hepatocellular carcinoma (HCC), AgNOR numbers and the expression of Ki-67 using MIB-1 antibody have been studied in paraffin-embedded specimens of 20 HCCs by means of a double staining method. We found that in individual cases the AgNOR number of MIB-1-positive cells was significantly higher than that of MIB-1-negative cells (p < 0.001). In addition, a significant correlation was seen between MIB-1 labelling index and the total mean AgNOR number (t-AgNOR) (r = 0.882, p < 0.001). The value of t-AgNORs was significantly higher in histologically less differentiated HCC (p < 0.005). The mean AgNOR number of MIB-1-negative cells (n-AgNOR) was also significantly higher in histologically less differentiated HCC (p < 0.04). By contrast, the mean AgNOR number of MIB-1-positive cells (p-AgNOR) did not significantly correlate with histologic grades (p = 0.265). However, the number of t-AgNORs was not significantly different between diploid and aneuploid tumours. In HCCs, it appears that AgNOR numbers were variably influenced by proliferative activities of tumour cells, phases of cell cycle and cell differentiation.

Quantification of nucleolar organiser regions in canine perianal gland tumours

The proliferative activity in 28 canine perianal gland tumours was examined by the quantitative evaluation of the nucleolar organiser regions associated with argyrophil proteins (AgNORs). These regions were stained with a specific silver stain and quantified directly by light microscopy and by computerised image analysis. The relationships between some of the parameters used (the number of AgNORs per nucleus, the area of AgNORs per nucleus and the ratio of the area of AgNORs to the area of the nucleus) were also examined in relation to the histopathological grades of the tumours. All the parameters showed a high correspondence with the tumours' proliferative activity, and the ratio of the area of AgNORs to the area of the nucleus was the most significantly correlated with the tumours' histological patterns.

Clinical and Histological Prognostic Factors in Axillary Node-Negative BreastCancer: Univariate and Multivariate Analysis with Relation to 5-Year Recurrence

In the recent years several studies have shown that about 30% of cases with axillary node-nagative breast cancer suffer relapse of the disease. Our attempt was made to evaluate the most significant prognostic factors to predict this high risk group which may be benefited from adjuvant treatment. For this purpose, we selected 9 patients out of 80 cases of node-negative breast cancer who had been followed up at least for 5 years and had the recurrence of the disease. For comparison, 16 patients from the same group who did not have relapse were selected on a random basis. Histology, receptor status, AgNOR, DNA flow cytometry and various immunohistochemical parameters were compared between the groups with recurrence and that without recurrence. On univariate analysis, tumor size, immunohistochemical expressions of PCNA, MIB-1, c-erbB-2 and S-phase fraction were significantly different between the above two groups. By multivariate analysis, immunohistochemical c-erbB-2 expression (more than 50% of cancer cells) was an independent parameter. As a summary from our studies, c-erbB-2 immunohistochemical staining on paraffin sections might be the best independent prognostic factor in axillary node-negative breast cancers.

Carcinogenesis and histogenesis of esophageal carcinoma

Dysplasia is one of the most important subjects regarding carcinogenesis of the esophagus, because there is continuing controversy as to whether esophageal dysplasia is a cancerous lesion or a noncancerous lesion. In this study, it is histopathologically shown that dysplasia has a close correlation with cancer itself and that there is no substantial difference in the cell proliferative activity of dysplasia and intraepithelial carcinoma. These findings thus show that dysplasia has as high a potential for malignancy, thus it should be treated as an extremely early cancerous lesion of the esophagus to substantially improve the long term results of this disease. Conversely, esophageal carcinoma with glandular and/or mucus-secreting components is commonly found in addition to the ordinary component of squamous cell carcinoma, which indicates that this type of esophageal tumor originates not only from the squamous epithelium but also from the esophageal mucus gland or the ductal epithelium. These findings support the concept of field carcinogenesis in esophageal carcinoma.

Argyrophilic nucleolar organizer regions in the evaluation of tumour progression in the oral mucosa: correlation with tissue pathology

The present study has analysed the numbers of argyrophilic nucleolar organizer regions (AgNOR) in normal tissues and in premalignant and malignant lesions of the oral mucosa in order to assess their potential as a biological marker for tumour progression. On comparison of AgNOR numbers in different lesions, carcinomas showed the highest number (4.65 +/- 0.98) compared to leukoplakias (2.38 +/- 0.47) and normal tissues (1.53 +/- 0.39). Spindle cell carcinomas and poorly differentiated squamous cell carcinomas had higher AgNOR counts than well-differentiated carcinomas. In various clinically different types of oral leukoplakia, the lowest AgNOR counts were observed in homogenous leukoplakia and the highest in speckled leukoplakia. No significant difference in AgNOR number was observed between non-dysplastic and dysplastic leukoplakia, although a significant difference was evident between dysplastic leukoplakia and normal oral mucosa. Correlating the AgNOR count and tumour progression, a significantly high positive correlation coefficient (r = 0.7969, P = 0.0000) was observed.

Which proliferation markers for routine immunohistology? A comparison of five antibodies

AIMS

To determine the best of five antibodies for immunohistochemical assessment of growth fraction in formalin fixed, paraffin wax embedded tissues.

METHODS

Sections from 100 recent, and 17 ten year old or over wax embedded blocks of normal and malignant tissues were immunostained with monoclonal Ki67, polyclonal Ki67, PC10, MIB1, and JC1. The antibodies were evaluated for specificity of nuclear versus cytoplasmic staining, cleanliness of background, and compared with the expected pattern of staining in normal tissues, defined immunohistochemically by monoclonal Ki67 antibody in frozen tissues or by tritiated thymidine uptake.

RESULTS

No marker was ideal, but best results were obtained with MIB1 and polyclonal Ki67, followed by JC1, PC10, and monoclonal Ki67.

CONCLUSIONS

For routine use, MIB1 or polyclonal Ki67 are the best proliferation markers in conventional histological preparations. The other markers tested cannot be recommended.

Argyrophilic nucleolar organizer regions may help the differential diagnostic distinction between chronic pancreatitis and pancreatic ductal adenocarcinoma

BACKGROUND

The aim of this study was to determine whether the number of argyrophilic nucleolar organizer regions (AgNORs) could be of diagnostic significance in differentiating between chronic pancreatitis and pancreatic ductal adenocarcinoma.

METHODS

The number of AgNORs was enumerated in biopsy specimens of normal pancreas, chronic pancreatitis, and pancreatic ductal adenocarcinoma.

RESULTS

The number of AgNORs was lower in patients with normal pancreas than in patients with chronic pancreatitis or pancreatic adenocarcinoma. In addition, the number of AgNORs was significantly lower in chronic pancreatitis than in pancreatic ductal adenocarcinoma (p < 0.001).

CONCLUSIONS

The diagnosis of pancreatic adenocarcinoma is usually clear. Difficulties can be encountered, however, in cases of chronic pancreatitis, specially when biopsy material is small. Our results suggest that the number of AgNORs may help in distinguishing between chronic pancreatitis and pancreatic ductal adenocarcinoma, especially in diagnostically difficult specimens.