AgNOR area in interphase nuclei of human tumours correlates with the proliferative activity evaluated by bromodeoxyuridine labelling and Ki-67 immunostaining

C-type natriuretic peptide (CNP) inhibits 7,12-Dimethylbenz[a]anthracene (DMBA)/Croton oil-induced skin tumor growth by modulating inflammation in Swiss albino mice

C-type natriuretic peptide (CNP) exhibits anti-inflammatory activity besides its natriuretic and diuretic functions. The present study aimed to determine the anticancer and synergistic therapeutic activity of CNP against a 7,12-Dimethylbenz[a]anthracene (DMBA)/Croton oil-induced skin tumor mouse model. CNP (2.5 µg/kg body weight) was injected either alone and/or in combination with Cisplatin (CDDP) (2 mg/kg body weight) for 4 weeks. The dorsal skin tumor incidences/growth and mortality rate were recorded during the experimental period of 16 weeks. The serum C-reactive protein (CRP), and lactate dehydrogenase (LDH) levels, infiltrating mast cells, and AgNORs proliferating cells count were analyzed in control and experimental mice. Further, the expression profile of marker genes of proliferation, inflammation, and progression molecules were analyzed using Reverse transcriptase-polymerase chain reaction (RT-PCR)/quantitative PCR (qPCR), western blot, and immunohistochemistry. The DMBA/Croton oil-induced mice exhibited 100% tumor incidence. Whereas, CNP alone, CDDP alone, and CNP+CDDP combination-treated mice exhibited 58%, 46%, and 24% tumor incidence, respectively. Also, a marked reduction in the levels of serum CRP and LDH, the number of infiltrating mast cells count and AgNORs proliferating cells count were noticed in the mice skin sections. Further, a significant reduction in both mRNA and protein expression levels of proliferation, inflammation, and progression markers were noticed in CNP (p < 0.01), CDDP (p < 0.01), and CNP+CDDP combination (p < 0.001) treated mice, respectively. The results of the present study suggest that CNP has anticancer activity. Further, the CNP+CDDP treatment has more promising anticancer activity as compared with CNP or CDDP alone treatment, probably due to the synergistic antiproliferative and anti-inflammatory activities of CNP and CDDP.

The Ribosome Biogenesis-Cancer Connection

Multifaceted relations link ribosome biogenesis to cancer. Ribosome biogenesis takes place in the nucleolus. Clarifying the mechanisms involved in this nucleolar function and its relationship with cell proliferation: (1) allowed the understanding of the reasons for the nucleolar changes in cancer cells and their exploitation in tumor pathology, (2) defined the importance of the inhibition of ribosome biogenesis in cancer chemotherapy and (3) focused the attention on alterations of ribosome biogenesis in the pathogenesis of cancer. This review summarizes the research milestones regarding these relevant relationships between ribosome biogenesis and cancer. The structure and function of the nucleolus will also be briefly described.

Prognostic Significance of Two Dimensional AgNOR Evaluation in Local Advanced Rectal Cancer Treated with Chemoradiotherapy

The prognostic significance of AgNOR proteins in stage II-III rectal cancers treated with chemoradiotherapy was evaluated. Silver staining was applied to the 3μm sections of parafin blocked tissues from 30 rectal cancer patients who received 5-FU based chemoradiotherapy from May 2003 to June 2006. The microscopic displays of the cells were transferred into the computer via a video camera. AgNOR area (nucleolus organizer region area) and nucleus area values were determined as a nucleolus organizer regions area/total nucleus area (NORa/ TNa). The mean NORa/TNa value was found to be 9.02±3.68. The overall survival and disease free survival in the high NORa/TNa (>9.02) patients were 52.2 months and 39.4 months respectively, as compared to 100.7 months and 98.4 months in the low NORa/TNa (<9.02) cases. (p<0.001 and p<0.001 respectively). In addition, the prognosis in the high NORa/TNa patients was worse than low NORa/TNa patients (p<0.05). In terms of overall survival and disease-free survival, a statistically significant negative correlation was found with the value of NORa/TNa in the correlations tests. Cox regression analyses demostrated that overall survival and disease-free survival were associated with lymph node status (negative or positive) and the NORa/TNa value. We suggest that two-dimensional AgNOR evaluation may be a safe and usable parameter for prognosis and an indicator of cell proliferation instead of AgNOR dots.

AgNORs count and DNA ploidy in liver biopsies from patients with schistosomal liver cirrhosis and hepatocellular carcinoma

OBJECTIVES

Argyrophilic nucleolar organizer regions (AgNOR) proteins are a set of argyrophilic nucleolar proteins that accumulate in highly proliferating cells, whereas their expression is very low in nonproliferating cells. The present study aimed to investigate the potential of DNA flow cytometry (FCM) and AgNORs count in the assessment of cellular kinetics of liver cirrhosis and hepatocellular carcinoma.

DESIGN AND METHODS

Small-needle liver biopsies (217) were included and were taken from 84 patients with hepatocellular carcinoma (HCC) (one biopsy from tumor lesion and the other from residual nontumor) liver tissues. Only one biopsy was taken from 49 patients with liver cirrhosis. One part of biopsy was subjected to flow cytometry, and the other, to histopathology and AgNORs counting.

RESULTS

An aneuploidy was shown in 44.5% of liver cirrhosis and in 78.6% of tumor sites. Aneuploid HCC cases showed high AgNORs count compared with diploid cases (3.407+/-1.18 vs. 1.74+/-0.9). An extremely significant increase in AgNORs count in tumor lesion (P<0.001) was found compared with residual liver tissues, liver cirrhosis and normal liver (3.89+/-0.827, 1.49+/-0.52, 1.62+/-0.29, and 1.3+/-0.17, respectively). In liver cirrhosis, dysplasia showed a significant relationship with ploidy (P<0.001) and AgNORs count (P<0.05).

CONCLUSION

AgNORs count and DNA ploidy analysis of core biopsy specimens are useful in the assessment of cellular kinetics of liver cirrhosis and hepatocellular carcinoma.

Proliferative activity of human thyroid cells in various age groups and its correlation with the risk of thyroid cancer after radiation exposure

CONTEXT

The thyroid gland is vulnerable to the carcinogenic effects of ionizing radiation, and there is a well-documented inverse correlation between thyroid cancer and age at exposure, particularly for ages less than 20 yr. One of the factors responsible for this phenomenon may be more rapid cell proliferation in children.

OBJECTIVE

The objective of this study was to determine the proliferative rate of normal human thyroid cells in different age groups.

DESIGN

We used immunohistochemical analysis to determine the Ki-67 proliferative index in 117 thyroid glands obtained at autopsy, including 25 fetal thyroids (11-40 wk gestation), 55 childhood thyroids (0-19 yr), and 37 adult thyroids (20-60 yr).

RESULTS

The rate of Ki-67 labeling in the three groups was 7.4 +/- 6.10, 0.23 +/- 0.15, and 0.08 +/- 0.04% respectively, demonstrating an overall trend for diminishing proliferative activity of thyroid cells with increasing age. However, a lack of correlation was noted between the slopes of cancer risk calculated from previous studies of irradiated populations and proliferative rate in the pediatric age intervals of 0-4 and 5-9 yr, suggesting that other factors are likely to be responsible for the particularly high sensitivity to radiation-induced thyroid cancer among the youngest children.

CONCLUSIONS

Our findings of a general decrease in proliferative activity of thyroid cells with age may explain, at least in part, the higher risks of radiation-related thyroid cancer in children compared with adults. However, the variation in the rate of cell proliferation is unlikely to be responsible entirely for this phenomenon and other factors may also be involved.

Nucleolar Organizer Regions as a Prognostic Indicator in Epithelial Cancers of the Ovary

Recent studies have shown that quantification of silver-stained nucleolar organizer region associated proteins (AgNORs) is correlated with ploidy and proliferative activity in several neoplasms. The prognostic value of this marker, however, has not been well defined in epithelial ovarian carcinomas (EOCs). We studied 84 cases of EOCs in an attempt to assess the potential prognostic significance of AgNORs and to compare the results with other prognostic factors in EOCs. Clinical, operative and treatment details, and follow-up data were recorded for each case. In univariate analysis, a highly significant correlation of AgNOR count with clinical stage (p < 0.01), histologic grade (p < 0.05), response to chemotherapy (p < 0.05), and biologic behavior (p < 0.01) was found. High AgNOR counts were observed in late stage (III and IV) tumors, grade 3 carcinomas, tumors in patients with partial response to chemotherapy, progressive disease, recurrence, or death from tumor. In multivariate analysis, AgNOR count at cut off 3.5 was found to be the third prognostic variable after response to therapy and stage. These observations suggest that AgNOR count holds promise for prediction of tumor aggressiveness in EOCs. However, its role as an independent prognostic variable of patient survival remains questionable.

Argyrophilic staining of nucleolar organizer region count and morphometry in benign and malignant melanocytic lesions

Differentiation between malignant melanomas (MMs) and benign nevi based on histologic features can sometimes be difficult. This study evaluated the diagnostic effectiveness of argyrophilic staining of nucleolar organizer regions (AgNORs) in separating benign nevi from MMs by assessing 27 compound nevi (CN), 20 dysplastic nevi (DN), 10 Spitz nevi (SN), and 24 MMs. Both AgNOR count and morphology variables were measured from the superficial, middle, and deep zones of the lesions using video image analysis. Malignant melanomas had a significantly greater AgNOR number per nucleus, mean AgNOR area per nucleus, and variation in AgNOR area per nucleus compared with all types of benign nevi (p < 0.05). In multivariate discriminant analysis using a combination of four AgNOR counts and morphometric parameters, all CN and DN, 8 of 10 SN, and 23 of 24 MMs could be correctly classified as benign or malignant. The results suggest that both AgNOR count and morphology help to separate benign and malignant melanocytic lesions and that the combination of both sets of parameters improves their discriminating ability.

Correlation between silver-stained nucleolar organizer region area and cell cycle time

BACKGROUND

The relationship between the population doubling time and the quantity of silver-stained nucleolar organizer region (AgNOR) interphase proteins was studied in cell culture at three different temperatures used to modulate the cell cycle duration.

METHODS

After MIB 1 and AgNOR combined staining, the quantity of AgNOR proteins was measured in cycling cells by image cytometry.

RESULTS

Among the several parameters calculated, the AgNOR relative area showed a strong correlation with the changes of the population doubling time induced by different temperatures.

CONCLUSIONS

The results support the hypothesis that the cell cycle time and the size of the ribogenesis machinery are coregulated and that measurements of AgNORs can thus be used as a static evaluation of the cell cycle duration in arbitrary units.

Morphometric analysis of argyrophilic nucleolar organizer regions (AgNORs) in nasopharyngeal carcinoma

BACKGROUND

Nucleolar organizer regions (NORs), which are loops of DNA containing ribosomal RNA genes, have been shown to correlate with cell proliferation and malignant transformation. Conventional eyeball measurement of silver staining NORs (AgNORs) is time-consuming and subject to error. The diagnostic value of AgNOR area in nasopharyngeal carcinoma (NPC) by computer-assisted morphometric analysis is evaluated.

METHODS

Silver-staining of NORs was applied to 23 paraffin sections of NPC containing both normal squamous epithelial and malignant cells. Various parameters of the AgNORs of these two cell types were analyzed by a computer-assisted image analysis system and then compared.

RESULTS

The mean AgNOR area, AgNOR/nuclear area ratio, and AgNOR area/count ratio of malignant tumors were statistically significantly higher than those for the normal epithelium. There was no significant difference in the AgNOR counts between the two cell types.

CONCLUSIONS

Computer-assisted morphometric analysis of AgNOR is an objective and reliable assessment method applicable to paraffin sections of NPC. The AgNOR area and its derivatives may aid in the diagnosis of NPC.

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.

The asialoglycoprotein receptor in human hepatocellular carcinomas: its expression on proliferating cells

The expression of the asialoglycoprotein receptor (ASGP-R) on human hepatocellular carcinoma (HCC) cells might be exploited to reduce the extrahepatic toxicity of DNA synthesis inhibitors by their conjugation with galactosyl-terminating peptides. In the present study we first assessed the frequency of ASGP-R expression in 60 HCCs. Secondly, we investigated whether the receptor was maintained on the plasma membranes of DNA synthesizing cancer cells. Needle biopsies of HCC were evaluated. Diagnosis and grading of HCC were performed on routine haematoxylin and eosin-stained sections according to Edmondson and Steiner (1953). Thirty-five tumours were grade I and II and were classified as well differentiated, while 25 tumours were grade III and IV and were classified as poorly differentiated. Sections from formalin-fixed, paraffin-embedded samples were incubated, after antigen retrieval, with an anti-ASGP-R monoclonal antibody revealed by secondary biotinylated antibody and streptavidin-biotin-peroxidase-diaminobenzidine reaction. A clear immunolabelling of plasma membranes of HCC cells was observed in 28 out of 35 (80%) well differentiated (grade I and II) and in five out of 25 (20%) poorly differentiated (grade III and IV) HCCs. The presence of the ASGP-R on the surface of DNA synthesizing cancer cells was also investigated after in vitro bromodeoxyuridine (BrdU) labelling of HCC samples by immunohistochemical visualization of both the ASGP-R and incorporated BrdU on the same section. The results obtained clearly demonstrated that DNA synthesizing cancer cells expressed the ASGP-R on their surface. The presence of ASGP-R on cell plasma membrane in the majority of differentiated HCCs and its maintenance on proliferating cells encourages studies in order to restrict the action of the inhibitors of DNA synthesis of HCC cells by their conjugation with galactosyl-terminating carriers internalized through this receptor.

The asialoglycoprotein receptor in human hepatocellular carcinomas: its expression on proliferating cells

The expression of the asialoglycoprotein receptor (ASGP-R) on human hepatocellular carcinoma (HCC) cells might be exploited to reduce the extrahepatic toxicity of DNA synthesis inhibitors by their conjugation with galactosyl-terminating peptides. In the present study we first assessed the frequency of ASGP-R expression in 60 HCCs. Secondly, we investigated whether the receptor was maintained on the plasma membranes of DNA synthesizing cancer cells. Needle biopsies of HCC were evaluated. Diagnosis and grading of HCC were performed on routine haematoxylin and eosin-stained sections according to Edmondson and Steiner (1953). Thirty-five tumours were grade I and II and were classified as well differentiated, while 25 tumours were grade III and IV and were classified as poorly differentiated. Sections from formalin-fixed, paraffin-embedded samples were incubated, after antigen retrieval, with an anti-ASGP-R monoclonal antibody revealed by secondary biotinylated antibody and streptavidin-biotin-peroxidase-diaminobenzidine reaction. A clear immunolabelling of plasma membranes of HCC cells was observed in 28 out of 35 (80%) well differentiated (grade I and II) and in five out of 25 (20%) poorly differentiated (grade III and IV) HCCs. The presence of the ASGP-R on the surface of DNA synthesizing cancer cells was also investigated after in vitro bromodeoxyuridine (BrdU) labelling of HCC samples by immunohistochemical visualization of both the ASGP-R and incorporated BrdU on the same section. The results obtained clearly demonstrated that DNA synthesizing cancer cells expressed the ASGP-R on their surface. The presence of ASGP-R on cell plasma membrane in the majority of differentiated HCCs and its maintenance on proliferating cells encourages studies in order to restrict the action of the inhibitors of DNA synthesis of HCC cells by their conjugation with galactosyl-terminating carriers internalized through this receptor.

The asialoglycoprotein receptor in human hepatocellular carcinomas: its expression on proliferating cells

The expression of the asialoglycoprotein receptor (ASGP-R) on human hepatocellular carcinoma (HCC) cells might be exploited to reduce the extrahepatic toxicity of DNA synthesis inhibitors by their conjugation with galactosyl-terminating peptides. In the present study we first assessed the frequency of ASGP-R expression in 60 HCCs. Secondly, we investigated whether the receptor was maintained on the plasma membranes of DNA synthesizing cancer cells. Needle biopsies of HCC were evaluated. Diagnosis and grading of HCC were performed on routine haematoxylin and eosin-stained sections according to Edmondson and Steiner (1953). Thirty-five tumours were grade I and II and were classified as well differentiated, while 25 tumours were grade III and IV and were classified as poorly differentiated. Sections from formalin-fixed, paraffin-embedded samples were incubated, after antigen retrieval, with an anti-ASGP-R monoclonal antibody revealed by secondary biotinylated antibody and streptavidin-biotin-peroxidase-diaminobenzidine reaction. A clear immunolabelling of plasma membranes of HCC cells was observed in 28 out of 35 (80%) well differentiated (grade I and II) and in five out of 25 (20%) poorly differentiated (grade III and IV) HCCs. The presence of the ASGP-R on the surface of DNA synthesizing cancer cells was also investigated after in vitro bromodeoxyuridine (BrdU) labelling of HCC samples by immunohistochemical visualization of both the ASGP-R and incorporated BrdU on the same section. The results obtained clearly demonstrated that DNA synthesizing cancer cells expressed the ASGP-R on their surface. The presence of ASGP-R on cell plasma membrane in the majority of differentiated HCCs and its maintenance on proliferating cells encourages studies in order to restrict the action of the inhibitors of DNA synthesis of HCC cells by their conjugation with galactosyl-terminating carriers internalized through this receptor.

Distinctive AgNOR patterns of myeloid and lymphoid blasts in acute leukemia

Bone-marrow aspiration smears of 38 cases of acute leukemia (19 acute lymphoblastic leukemia, 19 acute nonlymphocytic leukemia) were stained for argyrophilic nucleolar organiser regions (AgNOR). AgNOR were assessed numerically and morphologically. There were highly significant differences in AgNOR morphology between acute lymphoblastic leukemia and acute nonlymphocytic leukemia ANLL: lymphoblast AgNORs were usually small (<3 microm) "dots/chips," whereas myeloblasts showed larger "blebs," or a combination of the two types (complex structures). AgNOR number was significantly less in acute lymphoblastic leukemia. In acute nonlymphocytic leukemia cases, AgNOR number also showed direct correlation with Ki67 reactivity of leukemic blasts.

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.

Evaluation of argyrophilic nucleolar organizer regions in tongue squamous cell carcinomas

Using a silver staining technique, argyrophilic nucleolar organizer regions (AgNORs) were studied on the biopsy specimens taken from 67 tongue squamous cell carcinomas (SCCs), and the relations of the results of AgNORs to the clinicopathological findings, to the labelling indices of proliferating cell nuclear antigen (PCNA LI), and to the outcomes of the disease were investigated. The mean numbers of AgNORs per cell were 1.67 +/- 0.19 (n = 27) in the control squamous epithelia and 3.58 +/- 1.15 (n = 67) in the tongue SCCs, respectively, and a significant difference was found between the two groups (P < 0.0001). Concerning the clinicopathological findings, the mean numbers of AgNORs in the progressive cases (T3, T4), in the factor N-positive groups (N1, N2), and in the advanced stages (stages III, IV) were statistically higher than those in T1, T2, N0, and earlier stage (stages I, II) tumours, respectively. Similarly, a higher value of the AgNOR count was present in the histological grade III or diffuse invasive tumour. There was also a directly significant correlation between the AgNOR counts and the labelling indices of PCNA (r = 0.53, P < 0.0001). Concerning the outcome of the disease, the mean numbers of AgNORs were higher in the group with local recurrence or with lymph-node metastasis. A lower rate of 5 years' survival was found in the high value group (63.5%) of AgNORs compared with that of the low value group (86.0%), with a significant difference between the two groups (P < 0.05). The results suggest that AgNORs may reflect the degree of malignancy and cellular proliferation in tongue SCCs.

Ki-67 index as indicator of the post-surgical prognosis in feline mammary carcinomas

Forty-eight feline mammary carcinomas (FMC) were resected surgically from 48 cats to determine whether the Ki-67 index (Ki-67I) would provide an indication of the post-surgical survival time (PST). Twenty-four cats (50 per cent) were still alive (group A) one year after surgery, whilst 24 (50 per cent) (group B) had died. Formalin-fixed, paraffin wax-embedded histological sections were immunostained with a monoclonal antibody to Ki-67 (MIB-1) and at least 1000 nuclei in eight to 10 representative fields were counted. The Ki-67I was expressed as the percentage of positive nuclei. In FMC, the Ki-67I ranged from 7.5 to 49.7 (24.8+/-9.5). A statistically significant difference (P = 0.000006) in the Ki-67I was found between group A and group B cats. No other statistically significant differences were found between these groups. The Ki-67I did not correlate with age or different histological type, according to the WHO classification. A Ki-67I cut-off of 25.2 represents a useful tool for identifying FMC with a more aggressive course.

A comparative study of nucleolar organizer region, proliferating cell nuclear antigen and epidermal growth factor receptor staining in colon tumours

Several studies have reported that proliferating cell nuclear antigen (PCNA), nucleolar organizer regions (NOR) and epidermal growth factor receptor (EGF-R) are cellular proliferation parameters in malignant tumours. However, the correlation of EGF-R with PCNA and NOR has not been reported in colon tumours. To clarify this, we investigated the correlation of the expression of EGF-R with PCNA and NOR in colonic epithelial tumours. Using immunohistochemical staining and one-step silver staining techniques, the expressions of EGF-R-, PCNA- and NOR-associated protein were studied in paraffin sections from five normal mucosae, 10 adenomas with mild atypia, 16 adenomas with moderate atypia, 32 adenomas with severe atypia including carcinoma in situ and 47 with invasive colon carcinomas. Significant differences were found among the respective degrees of atypia in Ag-NOR counts, PCNA labelling index (LI), and the expression of EGF-R. However, there were no significant differences among the Ag-NOR counts of the severe atypia and invasive carcinoma. There was a significant positive correlation between Ag-NOR counts and PCNA LI (P < 0.001). The Ag-NOR counts and PCNA LI in EGF-R-positive cases were higher than in EGF-R-negative cases (P < 0.001). These results indicate that each of the parameters increased significantly with the increase in atypia and the progression of cancer. Epidermal growth factor receptor provokes an exacerbation of protein synthesis and the cell cycle in colonic epithelial tumours.

Argyrophilic nucleolar organiser regions (AgNORs) count as indicator of post-surgical prognosis in feline mammary carcinomas

Feline mammary carcinomas (FMC) were surgically resected from 51 cats to verify that the nucleolar organiser regions (AgNORs) count is related to the post-surgical survival time (PST). After one year post-surgery, 27 cats (group A) were still alive (52.9 per cent) while (41.7 per cent) (group B) had died as a consequence of FMC. Formalin-fixed, paraffin wax-embedded histological sections were stained with silver nitrate and the AgNORs were then counted at x 100 oil immersion objective. In FMC AgNORs count ranged from 1.2 to 12.1 (6.10+/-2.3). A statistically significant difference (P=0.000112) in the AgNORs count was found between cats from group A and group B. No other statistically significant differences were found between group A and B. AgNORs count was not correlated to age or different histological type, according to the WHO classification. Using this technique it is possible to identify two populations of FMC with a statistically significant difference in the PST.

Aneuploidy in sclerosing adenosis may predict an increased risk of malignancy. A study using the AgNOR silver stain

Sclerosing adenosis (SA) of the breast if a disease associated with an increase relative risk of malignancy. The exact incidence and factors influencing malignant transformation in association with SA are not well established. Two counts of the AgNOR silver staining technique have been correlated with ploidy and proliferative activity. The first count which is the mean number of AgNOR granules (mAgNOR), correlates with ploidy. The second count is the percentage of nuclei exhibiting > or = 5 AgNORs/nucleus (pAgNOR) and reflects proliferative activity. The hypothesis in the current study was that aneuploidy, as determined by the AgNOR silver staining technique, may potentially identify lesions of SA with an increased association with malignant breast disease. The AgNOR silver staining technique was performed on 69 cases of SA with the application of the two counts. Of these cases 53 were not associated with malignancy and 16 were associated with synchronous or metachronous carcinoma of the breast, these being 11 cases of invasive ductal carcinoma (IDC), four cases of ductal carcinoma in situ (DCIS) and one case of lobular carcinoma in situ (LCIS). The patient ages ranged from 27 to 84 years (median 53 years) with a median follow up of 28 months. Six of the 53 cases of SA no associated with malignancy (11%) had aneuploid mAgNOR counts of > or = 2.4 whereas 12 of the 16 cases associated with carcinoma (80%) had such counts (p < 0.0005). This included nine cases of IDC, two cases of DCIS and the case of LCIS. Of the six aneuploid cases not associated with malignancy, two cases showed cytological atypia, one case was associated with atypical ductal hyperplasia and one case was seen in a leukemic patient who had received chemotherapy and radiation therapy. The pAgNOR counts showed a statistically less significant correlation with malignancy (p < 0.03). These findings suggest that aneuploidy, measured by the AgNOR silver stein, seen in SA may help identify lesions with a higher relative risk of being associated with breast carcinoma and hence that may require more aggressive management than diploid ones.

Increased cell proliferation of urothelium in rat bladder following unilateral nephrectomy

PURPOSE

The aim of this study is to investigate the effect of unilateral nephrectomy on cell proliferation of normal urinary bladder epithelium in adult rats.

MATERIALS AND METHODS

Following unilateral nephrectomy or sham operation 5 rats for each time point were sacrificed and their bladders were removed at 6 and 12 hours and also on 1, 2, 4, 7, 14, 28, and 56 days. Another 5 rats were not operated and served as the control. The percent number of proliferating cell nuclear antigen (PCNA) positive cells and the number of argyrophilic nucleolar organizer regions (AgNORs) were determined for each bladder.

RESULTS

In the nephrectomized groups, a significant increase of PCNA expression in urothelial cells of the bladder was found at each sacrifice time with the exception of 28 and 56 days when compared with that of the control and corresponding sham-operated groups. Percent PCNA labeling index (PCNA-LI) reached a peak value of approximately 9.1% on day 2 post operation. From day 4 post nephrectomy, however, PCNA-LI decreased gradually reaching control levels by day 28. No significant difference was found between the control and sham-operated groups. The mean number of AgNOR dots in nephrectomized rats sacrificed on day 1, 2, 4, 7 and 14 post operation was significantly larger than that of the control and corresponding sham-operated groups.

CONCLUSION

The results suggest that unilateral nephrectomy temporarily enhances normal urothelial cell proliferation in adult rat bladder.

The AgNoR count in ulcerative colitis with and without dysplasia

The numbers of specific intranuclear AgNOR silver precipitates (AgNORs) and their relation to the Inflammatory Bowel Disease-Dysplasia Morphology Study Group's classification were studied in 134 colonscopic biopsy specimens of ulcerative colitis (UC) with and without dysplastic findings from 73 patients with active and inactive disease. In addition, 40 cases of colonic adenocarcinomas and 22 normal colonic mucosae were also assessed for comparison with the one-step silver staining AgNOR technique. Statistical comparison of the mean AgNOR number revealed a highly significant inter-class difference (P < 0.001) between UC without dysplasia and UC with dysplasia as well as between active and inactive UC. On the contrary, the AgNORs count did not separate colonic adenocarcinomas from UC with dysplasia either high or low grade nor these three classes from the group of UC with indefinite dysplasia. The quantitative evaluation of epithelial changes occurring in UC by the AgNOR method may help to establish the clinical management of colitis patients, in addition to qualitative morphological criteria.

Significance of AgNOR counts for distinguishing carcinoma from adenoma and hyperplasia in parathyroid gland

Nucleolar organizer region proteins, which can be stained and visualized by an argyrophil technique (AgNORs), are markers of cell activities, such as DNA transcription and proliferation, and they are useful for differential diagnosis between benign and malignant tumors. We counted both AgNOR numbers in 25 parathyroid lesions (three carcinomas, 11 adenomas, 10 hyperplasias, and one hyperplasia with carcinoma) to determine if the AgNOR number could be useful as a diagnostic aid in parathyroid neoplasms and hyperplasias, because it is often difficult to histopathologically distinguish among these lesions. The AgNOR numbers were significantly higher in carcinomas (3.18 +/- 0.05) than in adenomas (1.67 +/- 0.30, P < .001) or hyperplasias (1.85 +/- 0.16, P < .001), but there was no significant difference between adenomas and hyperplasias. These results suggest that AgNORs may be useful as an adjunct to discriminating carcinomas from adenomas or hyperplasias in the parathyroid gland.

Cell kinetics analysis of surgically resected non-small cell carcinoma of the lung using the AgNOR silver stain

Cell kinetics analysis of lung carcinoma using DNA flow cytometry has shown a significant correlation with the biological behavior of these neoplasms. Ploidy has shown a more significant association with aggressive behavior. The method may however not be available in all centers. Two counts of the AgNOR silver stain have been correlated with ploidy and proliferative activity (PA). The first count, which is the mean number of AgNOR granules (mAgNOR), correlates with ploidy. The second count is the percentage of cells with > 5 AgNORs/nucleus (pAgNOR), reflects PA. We performed the AgNOR silver stain using the two above-mentioned counts in 41 cases of surgically resected nonâsmall cell carcinoma of the lung. The cases included 14 adenocarcinomas, 24 squamous cell carcinomas, and three undifferentiated nonâsmall cell carcinomas. Follow-up data were available on 36 of the patients, ranging from 10 to 31 months (median 18 months). Thirteen of these patients (36%) developed progressive disease. Adenocarcinomas showed mAgNOR counts suggestive of aneuploidy (> 2.4) in nine of the 14 patients (64%) and 16 of the 24 squamous carcinomas (66%). The adenocarcinomas showed high pAgNOR counts (> 8%) in eight of the 14 cases (57%), in contrast to 15 of the 24 squamous carcinomas (62%). The AgNOR counts did not show any statistically significant correlation with tumor type, grade or stage of disease. The mAgNOR counts were aneuploid in all 13 progressive cases and in only 10 of the 23 stable cases (43%)(P=0.001). The pAgNOR counts were high in 12 of the 13 cases that progressed (92%), in contrast to 10 of the 23 stable cases (43%)(P=0.01). There is no significant evidence that squamous carcinoma of the lung may have a higher incidence of aneuploidy and high PA than adenocarcinoma. Our data also confirm previous data showing that aneuploid lung carcinomas have more aggressive behavior than diploid ones. This study also indicates that, despite the short-term follow-up data, the use of the AgNOR silver stain for cell kinetics analysis of nonâsmall cell carcinoma of the lung may potentially provide useful predictive information on the biologic behavior of lung carcinoma. Long-term follow-up may provide more significant information.

Prognostic value of nucleolar organizer regions in supraglottic carcinoma

The relationship of nucleolar organizer regions (NORs) to proliferative activity and tumor progression was studied in 16 supraglottic carcinomas. The number of NORs stained by a silver colloid staining method (AgNOR staining method) was determined. The mean AgNOR number tended to be higher (but not significantly so) in poorly differentiated tumors. Moreover as T and N categories and stage of the tumor rose, the AgNOR number also rose, but not significantly. More interestingly, the mean AgNOR number was significantly higher in the presence than in the absence of lymph node metastasis. These studies indicate that the AgNOR number might be of clinical value as a predictor of lymph node metastasis of supraglottic carcinomas.

Argyrophilic nucleolar organizer regions staining is useful in predicting recurrence-free interval in oral tongue and floor of mouth squamous cell carcinoma

BACKGROUND

Argyrophilic nucleolar organizer regions (AgNORs) represent a tissue marker of cell proliferative activity. The purpose of this study was to assess the prognostic value of AgNORs expression in oral squamous cell carcinoma (SCC).

METHODS

The AgNORs area/nucleus was studied in paraffin sections by means of digital image analysis in 43 cases of stage II oral tongue and floor of the mouth SCC.

RESULTS

Time free of disease was considered a dependent variable of a binary indicator of AgNORs expression (7.77 microns2/nucleus as a cut-off point). High AgNORs level was associated with a statistically significant negative effect on recurrence-free interval of disease in a Cox proportional hazards models controlled for occult lymph node metastasis, involvement of the surgical margins, thickness of the lesion, and vascular invasion.

CONCLUSIONS

The AgNORs area increased the capability of predicting which patients have a high risk of recurrence of cancer, and its evaluation may provide useful information for the therapeutic approach to the oral tongue and floor of the mouth SCC.

Investigation of carcinoma in situ cells of testis by quantification of argyrophilic nucleolar organizer region associated proteins (AgNORs)

The silver staining which specifically stains argyrophilic proteins (AgNORs) in interphase nuclei was applied to paraffin sections of 24 testicular specimens with carcinoma in situ (CIS). AgNOR area per nucleus was quantified by a computerized image analyser. Significant quantitative differences were found between CIS, Sertoli cells, and spermatogonia (P = 0.0001), with median values of 10.3, 2.8, and 1.4 microns2 in the three cell types, respectively. A Sertoli cell index (SCI), defined as the ratio between AgNORs in CIS or spermatogonia and Sertoli cells, was shown to be significant in the differential diagnosis of CIS cells from spermatogonia when 1.0 was used as the cut-off value (CIS > 1; spermatogonia < 1). Furthermore, CIS associated with non-seminoma was found to have a significantly higher level of AgNORs than CIS associated with pure seminoma (P < 0.01), indicating that subclonal variation in transformation potential might be present within morphologically identical CIS of the testis. It remains to be seen whether quantification of AgNORs in isolated CIS could be used to predict transformation of CIS into seminoma or non-seminoma.

Estrogen receptors, progesterone receptors, and cell proliferation in human breast cancer

The breast is a target organ for estrogens and progesterone. These hormones control several functions of the normal and abnormal mammary epithelium including cell proliferation. Most of the actions of estrogens and progesterone are mediated via specific steroid receptors, and one would expect that proliferating cells should contain estrogen receptors (ER) and/or progesterone receptors (PR). However, the correlation between receptor expression and cell proliferation is still controversial. In the present study we have examined 29 human breast cancer samples; in 17 of them we evaluated the simultaneous ER and PR localization with that of proliferating cell nuclear antigen (PCNA) and silver-stained nucleolar organizer regions (AgNORs) in a cell-by-cell study. We found that in almost 50% of the tumor biopsies examined, the cells expressing ER were significantly associated with elevated cell proliferation. In another group (38%) there were not significant differences between ER expression and cell proliferation. In only one of the samples (6%) the cells expressing ER showed lower cell proliferation. The study also revealed that in 44% of the tumors the PR expressing cells were associated with elevated cell proliferation. In a second group the PR expression was not significantly associated with cell proliferation (33% of the cases). Finally, in 22% of the samples the cells carrying PR showed lower cell proliferation. We also detected lower ER immunoreactivity in 30% of the breast cancer biopsies with one of the monoclonal antibodies against ER (antibody 1D5 directed against the A/B domain). This group of tumors was PR-negative (or very weakly positive) and had high proliferation. The presence of tumors with 'abnormal' ER proteins and displaying ER/PR significantly associated with elevated cell proliferation could have implications in human breast cancer treatment.

Staining of the nucleolar organizer regions: relevance in hematology

There is growing interest in staining for the nucleolar organizer regions to detect nucleolar organizer region-associated proteins. In some cases, this technique facilitates the study of hematological disorders and allows us to distinguish between certain pathologies. Furthermore, it can provide information about cell proliferation, activity and malignancy. This paper attempts to give the recent advances in the use of the staining of nucleolar organizer regions and its clinical relevance in hematology.

Interphase ribosomal RNA cistron staining in thyroid epithelial cells in Grave's disease, Hashimoto's thyroiditis and benign and malignant tumours of the thyroid gland

Aim-To evaluate the expression of ribosomal cistrons in human thyroid epithelial cells (TECs) of patients with Grave's disease, Hashimoto's thyroiditis and benign and malignant tumours of the thyroid gland.Methods-TEC nucleoli were investigated in fine needle biopsy specimens from 10 controls, 39 patients with Grave's disease, 15 with Hashimoto's thyroiditis, 56 with benign, and 15 with malignant tumours of the thyroid. A one step silver staining method was applied. In most cases serum concentrations of thyroxine and triiodothyronine as well as goitre size were determined. In every case 100 TECs were evaluated for the mean numbers of nucleoli and for the average number of argyrophilic nucleolar organiser regions (AgNORs) per nucleus.Results-NORs were activated in all patients, but not in controls. The numbers of AgNORs in patients with Grave's disease were closely correlated with thyroxine or triiodothyronine, or both, concentrations and with the size of the thyroid. In patients with Hashimoto's thyroiditis about 30% of TECs nucleoli did not contain AgNORs, whereas others were heavily impregnated with silver. Compared with controls and benign tumours, the nucleoli of carcinomatous TECs were larger and irregular in shape. The mean number of AgNORs per nucleus in malignant cells was higher than that in their benign counterparts.Conclusions-The mechanism by which NORs are activated in TECs varies depending on the type of lesion. The higher AgNOR score in TECs from malignant tumours can be used to distinguish them from their benign counterparts.

Gallbladder carcinoma: a video image analysis of AgNOR distribution and its relation to tumour stage and grade

The amount and distribution of interphase argyrophilic nucleolar organizer regions (AgNORs) was studied in 51 gallbladder surgical specimens including 32 primary carcinomas, 10 adenomas and 9 cases of chronic cholecystitis with calculi. The mean nuclear AgNOR area (NORA) and the AgNOR distribution score (NORDS), i.e. the percentage of cells carrying nucleolar aggregates with more than 6 distinct silver dots, were evaluated in 200 epithelial nuclei per specimen by means of automated image analysis and direct counting respectively. Statistical analysis (variance analysis and Student-Neuman-Keuls' test) performed on the pooled mean AgNOR values showed a significant difference (p < 0.001) between carcinomas and non-carcinomatous lesions. Both NORA and NORDS highly discriminated carcinomas with histopathological grade 4 versus cases with grade 1, 2 or 3 (p < 0.001); a less statistically significative p value (< 0.05) was encountered when NORDS values of well differentiated grade 1 carcinomas and adenomas were compared. The NORA parameter permitted the discrimination of stage IV versus stage I carcinomas (p < 0.001), while carcinomas in stage IV and those in stage II were distinguished with a p < 0.05; the NORDS parameter allowed also to distinguish stage IV from both stage I or II tumours (p < 0.001). Our results indicate that the above-mentioned AgNOR parameters may be utilized as additional, more objective quantitative criteria in the clinical-pathological assessment of the outcome of gallbladder carcinomas.

Nucleolar organizer regions in glottic carcinomas: comparison of DNA cytofluorometry and clinicopathological analysis

The significance of nucleolar organizer regions (NORs) and nuclear DNA content in 73 glottic carcinomas was assessed for proliferative activity and tumor progression. NORs stained with silver colloid were counted, and nuclear DNA content was assayed by cytofluorometry. The cytofluorometric study demonstrated that the percentage of tumors with aneuploidy tended to increase as histological differentiation decreased. Survival rates of patients with diploid and aneuploid tumors were not significantly different. AgNOR staining revealed that mean AgNOR numbers rose as histological differentiation of tumors decreased. Moreover, as T and N categories and stages showed advancing malignancy, mean AgNOR numbers tended to rise. However, there was no significant difference in survival rates between tumors with low and with high AgNOR counts. These studies indicate that while AgNOR staining is better than DNA cytofluorometry for determining histological differentiation of glottic carcinoma, neither is of prognostic value at the present time.

Argyrophilic nucleolar organizer region (AgNOR) area per nucleus as a prognostic factor in breast cancer

Whether argyrophilic nucleolar organizer region (AgNOR) is a predictor of prognosis in breast cancer is controversial. The semiquantitative procedure used to calculate interphasic argyrophilic dots optically is neither reliable nor reproducible. We measured the mean area of AgNOR dots, the mean AgNOR area per nucleus (MA), and the mean AgNOR number per nucleus (MN) by automated image analysis in specimens from 131 patients with breast cancer. Higher MA (> 7.41 microns2), detected in 22 (16.8%) of 131 patients, did not correlate with clinicobiologic variables, except for DNA ploidy status. Overall survival was significantly better in patients with lower MA than in those with higher MA. On multivariate analysis, MA was a significant independent factor, followed by nodal status. These findings indicate that expression of AgNOR should be evaluated in terms of area occupied and that the mean area of AgNOR per nucleus (MA) is an important prognostic factor in the overall survival of breast cancer patients.

Argyrophilic nucleolar organizer regions and bromodeoxyuridine and 3[H]-thymidine labelling indices in colorectal cancer

The count of argyrophilic nucleolar organizer regions (AgNORs) has been proposed as a useful method for evaluating cell replication in human tumours. The current study was undertaken to compare AgNOR values in colorectal cancers with two better established methods for investigating cell proliferation such as bromodeoxyuridine (BrdUrd) and 3[H]-thymidine (3[H]dT) labelling indices (LIs). Because some concern still exists regarding accuracy and reproducibility of AgNOR quantifying methods, we carried out a control study by independently repeating the same measurements (number, area and area per silver-stained NOR particle) in two centres with different operators and computer-assisted image analysers on 40 colorectal carcinomas. AgNOR values recorded in the two centres were strictly correlated (r = 0.75; P < 0.001 for number; r = 0.62, P < 0.01 for area; r = 0.63, P < 0.001 for area per silver-stained NOR particle) and the range of values were almost identical. Then, AgNOR values were compared with BrdUrd and 3[H]dT LIs, respectively obtained by in vivo incorporation and in vitro incubation in the same series of colorectal carcinomas. No correlation was found between AgNOR values and BrdUrd or 3[H]dT LIs. BrdUrd and 3[H]dT LIs were instead reciprocally significantly correlated. No evident correlation was seen between LIs or AgNOR values and clinico-pathological parameters of the tumour. In conclusion, in colorectal neoplasms, AgNOR values did not appear to relate with more direct parameters of cell proliferation. It follows that AgNOR reliability as a biomarker of cell proliferation remains questionable.

Cell proliferation patterns and p53 expression in gastric dysplasia

Gastric dysplasia (high-grade, HGD, and low-grade, LGD) and normal mucosa were tested for anti-p53, anti-Ki-67 and anti-PCNA monoclonal antibodies on paraffin sections, and for relative AgNOR area and number on semithin Epon-Araldite sections. The proliferative compartment in normal mucosa was restricted to the middle layer corresponding to the neck-isthmus region. In LGD and HGD there was an expansion of this compartment to the lower and upper layers of mucosa, and in HGD in particular to the upper layer. p53 was always negative in LGD as well as in normal mucosa, while it was positive in 34 out of 51 cases of HGD. The most discriminant variables between LGD and HGD were relative AgNOR area and the percentages of MIB-1, p53 and PCNA. In p53-positive HGD the highest percentages of PCNA and MIB-1 were in the middle and upper layers (PCNA) or the upper layer (MIB-1), while in p53-negative HGD cases cell proliferation was maximal in the middle layer, although also present in the upper layer. The majority of cases of LGD did not demonstrate cell proliferation in the upper layer, but 5 cases behaved similarly to the p53-negative HGD cases. No significant correlations were found among percentages of MIB-1 and of PCNA and relative AgNOR area and number.

Silver-stained nucleolar (Ag-NOR) cluster size in feline mammary carcinomas: lack of correlation with histological appearance, mitotic activity, tumour stage, and degree of nuclear atypia

The relationship between Ag-NOR cluster size, mitotic index, tumour stage, degree of nuclear atypia and histological appearance was evaluated in a series of feline mammary carcinomas. The mean Ag-NOR cluster area per cell in these tumours ranged from 1.86 to 6.25 microns 2 and was not related to any other parameter studied. This suggests that Ag-NOR cluster size measurement is of poor diagnostic and prognostic value for feline mammary carcinomas.

Nucleolar organizer regions in adenoid cystic carcinoma of the salivary glands

In this study of proliferative activity of adenoid cystic carcinomas (ACCs) with different histological patterns, the argyrophilic staining method of nucleolar organizer regions (AgNORs) was applied to paraffin sections from 25 tumors. Sixteen of the neoplasms showed a mixture of different histological patterns in the same section. The AgNOR numbers in the different histological pattern areas in the same tissue sections of all 16 tumors were lowest in the cribriform, intermediate in the trabecular, and highest in the solid pattern areas. The mean AgNOR number was highest in the solid pattern (3.33 +/- 0.52), and lowest in the cribriform pattern (2.12 +/- 0.43). The results show the order of proliferative activity in the different histological pattern areas of ACC, and explain the previous clinical finding that the prognosis of ACC is poorest in solid pattern ACCs. AgNOR staining appears to be a useful technique for evaluation of the proliferative activity of each histological pattern area of ACC, especially when there are different histological pattern areas in the same tissue section.

Nucleolar organizer regions and image analysis nuclear morphometry of small cell (nevoid) melanoma

Small cell (nevoid) melanomas may provide difficulties in diagnosis as their constituent cell type resembles a benign nevoid melanocyte. In the present study, 10 small cell melanomas were analyzed for the silver staining of their nucleolar organizing regions (AgNORs), and their nuclear area and perimeter were measured by computerized digital image analysis and compared with 10 superficial spreading melanomas lacking small cell differentiation and 10 dermal nevi. The average number of AgNORs per nucleus was 5.83 (SD +/- 1.69) for small cell melanomas and was significantly different when compared with 8.49 (SD +/- 1.58) for superficial spreading melanomas (p < 0.05) and 2.71 (SD +/- 0.50) for dermal nevi (p < 0.05). Digital image analysis confirmed that the nuclear perimeter and nuclear area of cells in nevoid melanomas did not significantly differ from those of ordinary dermal nevi (p > 0.05), but both group were significantly different from superficial spreading melanomas lacking a small cell morphology (p < 0.05). Counting AgNOR numbers may be useful in evaluating small cell (nevoid) melanomas and provides a technique for differentiating their constituent cell from ordinary nevus cells. Nuclear morphometry determined by digital image analysis may help better define the nuclear size in small cell melanomas.

Standardized staining and analysis of argyrophilic nucleolar organizer region associated proteins (AgNORs) in radically resected colorectal adenocarcinoma--correlation with tumour stage and long-term survival

Quantification of silver-stained nucleolar organizer region associated proteins (AgNORs) was introduced in histopathology as a marker of cellular and nucleolar activity. However, due to the poor staining quality obtained on routinely processed archival material, the method yielded controversial and sometimes non-reproducible results. The recent introduction of wet autoclave pretreatment has reliably improved AgNOR staining quality on routinely formalin-fixed and paraffin-embedded tissues. In the present study, 92 routinely processed colorectal carcinomas were investigated, applying this novel staining technique. Subsequent standardized morphometric analysis revealed, irrespective of common tumour staging or grading classifications, a statistically highly significant correlation between AgNOR parameters and clinical course. The usefulness of standardized AgNOR parameters for the independent prediction of patient survival was proven by uni- and multivariate analysis.

Validation of silver-stained nucleolar organizer regions for evaluation of invasive character of urinary bladder carcinoma in rats and mice

A series of 8 rat and 16 mouse invasive bladder carcinomas were investigated for the presence of silver-stained nucleolar organizer regions (AgNORs) to clarify whether this parameter is applicable to the estimation of their invasive character. With regard to number of AgNORs per cell, neither rat nor mouse carcinomas showed any difference between invasive and noninvasive sites within the same tumor. However, the frequency of cancer cells bearing bizarre dots, irregular in size and shape, was significantly higher at sites of actual invasion. Quantitative data generated using an image analyzer revealed significantly lower values for NOR roundness and significantly larger NOR size in invasive sites than in noninvasive sites in all groups. Double staining for the proliferation marker proliferating cell nuclear antigen (PCNA) and AgNORs was performed on eight rat carcinomas and a close correlation between the two was confirmed. Thus the number of AgNORs in PCNA-positive cells was significantly greater than in PCNA-negative cells. Furthermore, a particularly strong correlation was observed for incidences of PCNA-positive cells and bizarre dots (P < 0.01). The quantitative data also demonstrated significant differences in size and shape of dots. It is concluded that AgNORs have diagnostic value for the invasive character of bladder carcinomas.

Prognostic relevance of pretreatment proliferative rapidity of marrow blast cells in childhood acute lymphoblastic leukaemia

Cell proliferation rate is a well-established prognostic factor in cancer, but it has not been considered to identify the risk group of childhood acute lymphoblastic leukaemia (ALL) at presentation. We carried out a study to demonstrate the prognostic importance of the rapidity of cell proliferation in patients with ALL. To measure the rapidity of cell proliferation we used the parameter relative to the area of silver-stained nucleolar organiser regions (AgNORs) as evaluated by morphometric analysis on smeared marrow blast cells. The mean AgNOR area of leukaemic marrow cells was measured in 119 children. By using a cut-off value of 3 microns2, we identified a group of 91 children with low proliferating blast activity (mean AgNOR value 2.11 microns2) and a group of 28 children with high proliferating activity (mean AgNOR value 3.29 microns2). The group of patients with a mean AgNOR value > 3 microns2 was characterised by a higher number of deaths, more frequent relapse and shorter time interval to relapse than the group of patients with mean AgNOR value < 3 microns2 (P < 0.01). Multivariate analysis performed to include T-cell immunophenotype, FAB morphology, leucocyte count and presence of mediastinal mass showed that the mean AgNOR value was the only independent predictor of unfavourable event-free survival probability (P > 0.01). Our results indicate that the rapidity of marrow blast cell proliferation is an important prognostic parameter in childhood ALL and should be routinely introduced in the group risk definition.

Nucleolar organizer regions in tongue carcinomas induced in rats: comparison with DNA cytofluorometric analysis

Eleven papillomas and 25 carcinomas were induced in rat tongues by oral administration of 0.001% 4-nitroquinoline 1-oxide (4NQO) in drinking water, and the biological characteristics and proliferative activity of the tumors were investigated by both DNA cytofluorometry and the argyrophilic nucleolar organizer region (AgNOR) staining method. The histopathological characteristics, the mean number of AgNORs per cell and DNA ploidy patterns were compared. The mean AgNOR number was lowest in normal epithelium (1.65 +/- 0.10), and highest in squamous cell carcinomas (2.97 +/- 0.70) and intermediate in papillomas (1.87 +/- 0.28). The differences were statistically significant. All normal epithelium and all papillomas showed a diploid pattern. Eighteen (72%) of 25 squamous cell carcinomas showed a diploid pattern, while 7 (28%) showed a diploid plus tetraploid pattern. There was a significant difference in the mean AgNOR number between the two ploidy groups of squamous cell carcinomas. These results suggest that the mean AgNOR number may reflect the histological grade in the process of carcinogenesis and polyploidization of carcinomas.

The value of the AgNOR staining method in identifying carcinoma in situ testis

An early and reliable diagnosis is necessary in order to have the chance of a curative therapy of Carcinoma in situ testis (Cis). Forty-six testicular biopsies were investigated to assess the value of the AgNOR staining method in comparison to placental alkaline phosphatase (PLAP) immunostaining. Both methods provided corresponding results and identical tumor cells were recognized in serial sections. The mean AgNOR counts per nucleus were 26.86 (19-52, SD: 2.68) for CIS cells, 8.18 (5-14, SD: 2.20) for spermatogonia and 12.96 (9-18, SD: 2.44) for Sertoli cells, without the counts overlapping within these three groups. Even single CIS cells are easily and reliably recognizable by their typical AgNOR pattern and their high AgNOR count per nucleus. The independent estimation of 9 testicular biopsies with the AgNOR staining method and the PLAP immunostaining correspondingly revealed 7 biopsies with CIS. Two biopsies lacked tumor cells. The AgNOR staining method can be recommended as an additional diagnostic tool in identifying CIS, because of the short and convenient staining procedure, low costs and the applicability on formalin-fixed and paraffin-embedded material.