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Objective: Prostatic diseases are a major cause of morbidity and mortality. The need is to detect the disease early in its natural history and manage it aggressively. Prostate-specific antigen (PSA) is not very sensitive, thus other indices are being employed. Argyrophillic nucleolar organizer region (AgNOR) count is the proliferative index marker used in our study. Our main objective was to evaluate the role of AgNOR in prostatic lesions and to find a correlation between serum PSA and AgNOR counts. Patients and Methods: We evaluated 60 patients of prostate diseases over a year. The patients were classified as benign prostatic hyperplasia (BPH), prostatitis, or prostatic adenocarcinoma (Ca). Patients with suspicious areas or foci of prostatic intraepithelial neoplasia (PIN) on histology were subjected to a slide review. All slides were H&E and AgNOR stained. Results: The difference between the mean AgNOR counts of BPH and prostatitis was significant, as between BPH and PIN (p < 0.001). The difference between low- and high-grade PIN was also significant.Ca prostate showed a significant increase in AgNOR counts from benign diseases; and also between localized and metastatic carcinoma (p < 0.001). On finding a correlation between serum PSA values and AgNOR counts, they were significant for benign and carcinoma cases (p < 0.001), though not for PIN. Conclusions: Our study depicts the usefulness of AgNOR counts in the diagnosis of various prostatic diseases including the pre malignant PIN. The relation between serum PSA and AgNOR was highly significant for BPH and Ca prostate. Hence, AgNOR is an efficient adjunct to our diagnostic armamentarium leading to improved prognostication and management. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

[Display omitted] • Only Leishmania -infected dogs showed biochemical alterations. • AgNORs per cell were significantly higher in clinically affected dogs. • Enhanced histopathological lesion score was observed in Leishmania -infected dogs. • Number of NORs and histopathological lesion score was positively correlated. • AgNOR expression and renal lesions were associated with clinical signs. Hyperactivation of tubular cells contributes for the progression of kidney lesions. The exacerbated expression of immunological proteins and ribosomal DNA (rDNA) transcriptional activity are observed in tubular cells. This intensified expression results in more prominent hypertrophic changes and is often accompanied by increased expression of factors involved in different phases of ribosomal biosynthesis, such as the nucleolar organizer regions (NOR). The aim of this study was to evaluate whether there is an association between NOR proteins, renal impairment, and clinical status in Leishmania -infected dogs (CanL). Forty-five dogs with CanL and six uninfected controls were assessed in this study. PCR was performed to detect parasites' nucleic acids in kidney. Histopathological analyses were performed in kidney fragments, and NOR was detected by Ag stain (AgNOR). Leishmania -infected dogs showed more intense inflammation and collagen deposition compared with uninfected controls. Biochemical alterations were observed only in Leishmania -infected dogs. AgNORs per cell were significantly higher in clinically affected dogs and higher histopathological lesion score was observed in Leishmania -infected dogs. Positive correlations between number of NORs per cell in medullary region and histopathological lesion score were observed. Furthermore, AgNOR expression, intensity of renal lesions, and clinical sigs was associated in Leishmania -infected dogs. We propose that the detection of AgNOR proteins could be used to better estimate the kidney tubular damage at the time of examination in Leishmania -infected dogs as a marker to estimate renal impairment in dogs with CanL. [ABSTRACT FROM AUTHOR]

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This article discusses a study which examined the association of nucleolar organizing regions and Ki-67 expression with recurrence rate of hair follicle tumor in dogs. The study used tissue specimens to prepare sections for histological staining for number of nucleolar organizing region and immunohistochemical staining for Ki-67. It showed that head, dorsum and limbs were the most affected sites. It also found that malignant trichoepithelioma presented significantly higher mitotic index, number of nucleolar organizing regions and Ki-67 expression.

Objectives: We planned this study to evaluate the proliferative activity of the oral mucosal epithelial cells of smokers and non-smokers via nuclear morphometry and AgNOR counts. Patients and Methods: Smears were collected from normal-appearing mouth floor mucosa of 40 non-smokers and 40 smokers between ages of 50 and 70. AgNORs were counted in the first 50 well-fixed, nucleated squamous cells and nuclear areas were calculated via computerized image analyzing system. Results: Statistically mean AgNOR numbers per nucleus in the nonsmoking group (3.47±0.30) was lower than the smoking group (4.22±0.39, p<0.001), and mean nuclear areas of squamous cells of smokers (94.32±1 0.08) was also significantly higher than non-smokers (87±9.4, p<0.05). The mean number of nuclei having more than 5 AgNORs was 14.6% and 36.8% in non-smokers and smokers, respectively. Conclusion: Our results support that smoking is a severe risk factor for oral mucosal proliferative lesions and exfoliative cytology can be the preferred method for screening of oral mucosal lesions. [ABSTRACT FROM AUTHOR]

Summary: The argyrophylic staining of the nucleolar organizer regions (AgNOR positive response) in interphase nuclei is often related directly to the cellular demand for ribosome biogenesis and is considered of relevance in studies of tumor pathology. Transformation of human breast epithelial MCF-10A cells by the c-Ha-ras oncogene results in altered growth, invasiveness and tumorigenicity in nude mice. Since ras transformation may be associated with a more intense nucleolar activity, we examined the influence of transfection by the Ha-ras oncogene on AgNOR staining response in MCF-10A cells. Following assessment of the AgNOR response with video image analysis, the AgNOR-positive areas and the AgNOR area/nuclear area ratio, but not the number of AgNOR aggregates or dots per nucleus, were found to be much higher after ras transformation. A role of the Ha-ras transformation on the nucleolar activity of the MCF-10A is thus suggested as assessed by the AgNOR staining. Based on data in the literature, it is also hypothesized that a decreased wild-type p53 level, possibly promoted by the ras transformation, may be associated with the increased AgNOR response. [Copyright &y& Elsevier]

Analysis of the nucleolus organizer regions by silver nitrate (AgNOR), fluorescent in situ hybridization (FISH) and C-banding of Serrapinnus notomelas from the Paraná River, PR, Brazil revealed intrapopulational polymorphisms that could be classified into six patterns (I–VI). Pattern I consisted of a single nucleolus organizer region (NOR) on chromosome pair 26 with at least one active homologue, indicating that it was a preferential NO. This NOR was also present in all the other patterns. In addition, seven other variable pairs appeared in patterns II–VI. These polymorphisms may indicate transpositions of rDNA genes, located on pair 26, to various sites in the genome. These transpositions may be due to transpose mechanisms or reinsertion into sites that have sequences homologous with the inserts. C-band analysis also reflected this variability and confirmed the various patterns described here. [ABSTRACT FROM AUTHOR]

Background: Distinguishing mild and moderate epithelial dysplasia is difficult and controversial. We demonstrated earlier that silver-stainable nucleolar organizer region (AgNOR) is a simple, inexpensive and quantifiable method which can standardize this distinction reliably. Objective: To establish a cut-point mean AgNOR count for epithelial dysplasia validated by bootstrapping. Methods: One hundred oral leukoplakia biopsies at Dr R. Ahmed Dental College, Kolkata, India, examined for epithelial dysplasia using standard method (gold standard) were assessed for their mean AgNOR counts. A cut-point was selected employing receiver operating characteristic (ROC) curve. This estimate was stabilized by 10 000 resamples (with replacement) using parametric and non-parametric bootstrap, a Monte Carlo statistical method, corrected for bias to estimate standard errors (SE) of cut-point. Results: Area under the curve (AUC) was 74%; non-parametric method suggested mean AgNOR cut-point = 2.42 AgNORs/nucleus; parametric method suggested cut-point = 2.57. The cut-point 95% confidence intervals (CIs) (bias corrected and accelerated) from parametric method (2.31; 2.66) was lower than non-parametric (2.43; 2.82). Conclusion: Applying a conservative paradigm, taking the lowest of all bootstrap 95% CIs, we suggest that mean AgNOR count of 2.3 be used as a cut-point for distinguishing between mild and moderate dysplasia. This strategy will provide an inexpensive, meaningful, definitive, reproducible and consistent diagnostic test for epithelial dysplasia. [ABSTRACT FROM AUTHOR]

The aim of this study was to review all the cases of central giant cell lesions (CGCLs) of the jaws which appeared in archives of Government Dental College and Hospital, Nagpur, during the period 1978-2004. CGCLs which were termed 'aggressive' based on clinical behavior were compared with 'non-aggressive' lesions in order to evaluate if any histologic difference existed between them. In addition, a study of silver (Ag) nucleolar organizing regions (AgNOR) counts was performed to delineate lesions of varying behavior. A total of 34 cases were examined for clinical and radiologic features, and 27 cases were evaluated for histopathology. We identified statistically significant differences between aggressive and on aggressive lesions with respect to certain histological characteristics such as shape of mononuclear cells, shape of giant cells, and number of nuclei per giant cell. It was also found that there was a definite and statistically significant correlation between the aggressiveness of the lesion and the AgNOR count. [ABSTRACT FROM AUTHOR]

Conclusion. While most results concerning DNA and nucleolar organizer region (AgNOR) parameters fit with previous studies, the percentage of aneuploidy looks like a promising prognostic parameter. The observed intratumoral heterogeneity could represent a possible source of conflicting and inconsistent results. Objectives. The aims of our study were to determine the prognostic relevance of different DNA and AgNOR parameters in laryngeal squamous cell carcinoma (SCC) and compare these findings with established prognostic factors including tumor stage and grade, as well as the detection of possible intratumoral heterogeneity. Materials and methods. Sections from 62 laryngeal SCCs were analyzed for DNA content, DNA index, S-phase, percentage of aneuploidy, and AgNOR. Of 62 samples, 31 morphologically similar tumor samples were analyzed for the same parameters in three different tumor areas defined as tumor center, invasive tumor margin, and transformation margin between tumor and normal-appearing mucosa. Results. Our study showed that DNA and AgNOR parameters correlated with T stage, lymph node involvement, and histologic grade regardless of tumor areas. Significant correlation was found between mean number of AgNOR per nucleus and percentage of aneuploidy. Clinical stage and percentage of aneuploidy correlated with survival (p<0.02). Heterogeneity DNA study revealed aneuploidy in central portions of 90% of tumors, while in margins aneuploidy was demonstrated in about half of the patients. [ABSTRACT FROM AUTHOR]

The multidrug resistance 1 (MDR1) gene product, P-glycoprotein (Pgp/p170) is a membrane protein, which acts as an ATP dependant efflux pump that expels a wide variety of organic compounds including chemotherapeutic agents from the cell. Pgp over expression has been demonstrated to be linked with poor treatment outcome and poor prognosis in a number of malignant tumors. AgNORs is a simple, reliable and inexpensive method of evaluating the proliferative activity of a tumor. We have studied MDR1 expression and AgNORS in 41 cases of acute leukemia in children. In this study, AgNOR counts in patients with acute lymphoblastic leukemia (ALL) L2 subtype (FAB classification) were significantly higher as compared to the ALL L1 subtype. Similarly, mean AgNOR count in the acute myeloid Leukemia (AML) M2 subtype was significantly higher as compared to the ALL L1 subtype. However, there was no correlation between AgNOR and treatment outcome or between AgNOR counts and MDR1 expression in any of the subtypes of acute leukemia included in this series. In AML, MDR1 gene expression was found to be related to reduced remission induction rates and hence poorer prognosis. In ALL, our study has shown no difference in remission induction between MDR1 positive and MDR1 negative cases. This would suggest that factors other than MDR1 may be of relevance in Pediatric ALL. [ABSTRACT FROM AUTHOR]

Summary: Abnormalities in any component of the cell cycle regulatory machine may result in oral cancer, and markers of cell proliferation have been used to determine the prognosis of tumor progression. The aim of this study was to determine whether silver-stained nucleolar organizer region (AgNOR) and Ki-67 measurements could improve the assessment of growth rates in oral lesions. Eighty-three oral biopsies were studied, 20 of which were classified as fibrous inflammatory hyperplasia (FIH), 40 as leukoplakia (LKP) and 23 as oral squamous cell carcinoma (OSCC). Within the LKP group, 22 out of 29 biopsies were diagnosed as non-dysplastic leukoplakia (LK) and 18 as dysplastic leukoplakia (DLK), presenting discrete, moderate and severe dysplasia. Ki-67 immunolabeling of the lesions increased steadily in the following order: FIH, DLK, LK and OSCC, indicating that Ki-67 is a good marker for predicting the proliferative fraction among benign, premalignant and malignant oral lesions. The median values of AgNOR parameters indicate that the morphometric index gives better results regarding the proliferative rate than the numerical one. A series of linear regressions between AgNOR parameters and Ki-67 showed positive associations. We conclude that a combination of Ki-67 and morphometric AgNOR analyses could be used as an aid in the determination of the proliferative status of oral epithelial cells in oral cancer. [Copyright &y& Elsevier]

Abstract: Traditional criterions are not sufficient to predict accurately the recurrence of transitional cell carcinoma of the urinary bladder. Therefore, we aimed to evaluate the AgNORs via total AgNOR area/nucleus area (TAA/NA) for each cell as a prognostic parameter, in TCC of urinary bladder. Tumor tissues of 20 consecutive cases of male bladder cancer patients were divided into two groups as middle differentiated (LG) and high grade (HG). The extra-tumoral tissue (ETT) samples of 10 males served as control group. A second control group (HC) consisted of five healthy and normal bladder tissue samples. The 3μm of sections from each paraffin embedded tumoral, extra-tumoral and normal tissue samples served as patient and control groups. After deparaffinization and rehydratation steps, silver (AgNO3) staining of nucleolar organizer regions-associated proteins (AgNORs) was performed. Instead of Giemsa stain, we used Hematoxylin for contra staining. The images of the 100 analyzable nuclei from each tissue sample, transferred by means of a video camera and video capture card from microscope and recorded onto a computer. Software was prepared in Delphi language for analysis. Mean (E+02) TAA/NA values of HC, ETT, LG and HG groups were 6.97+2.80, 5.70+1.82, 7.80+3.22 and 9.24+3.88, respectively. Statistical comparisons have shown significant differences between all groups.In conclusion, mean TAA/NA per cell has a potential to be a prognostic parameter. Therefore, further evaluation of big patient series will be useful. [Copyright &y& Elsevier]

This study was conducted in the department of Pathology King Edward Medical University, from June to December 2002 to introduce the new method of AgNOR staining and its interpretation to increase its reliability. A total of 60 brain specimens were stained with modified AgNOR technique. The diagnosis of malignancy was made on H & E staining. AgNOR counts, variation in size and dispersion of AgNOR dots in cells were graded and compared in malignant and non-malignant lesions. Modified method of AgNOR staining and interpretation was an easy, reliable and reproducible alternative to traditional AgNOR techniques for evaluating proliferation activity of cells in malignant and benign brain lesions. mAgNOR counts of different grades of astrocytoma (2.97 ± 0.96, 3.97 ± 0.43, 6.01 ± 2.74 and 8.01 ± 3.56) were significantly ( P < 0.01) greater when compared with counts of normal brain (0.40 ± 0.01), and reactive gliosis (0.60 ± 0.01). AgNOR size and dispersion were of higher grade in a significantly greater proportion of malignancy when compared with benign conditions ( P < 0.05). The AgNOR dots were brighter and more clear with modified staining when compared with previous studies. We conclude that modified AgNOR staining technique is simple, quick and reliable to evaluate cell proliferation by detecting AgNORs size and dispersion. In future, AgNOR size and dispersion should be considered rather than the count only. We recommend the use of morphometry for AgNOR size in future. We also recommend the use of modified AgNOR staining for obtaining sound and confidant results in routine paraffin sections. [ABSTRACT FROM AUTHOR]

Efficiency and mechanisms of action of photodynamic therapy of M-1 sarcoma were studied experimentally on rats using photodithazine, a novel chlorine photosensitizer. The tissue and cellular targets for this agent are vascular wall, plasma membrane of tumor cells, and intracellular structures responsible for proliferation and biosynthesis. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of the current study was to evaluate the effect of alcohol on the proliferative activity of epithelial cells in the lingual mucosa of mice by means of silver-staining nucleolar organizer region (AgNOR) count and area measurements. Forty-eight CF1 mice were separated into three groups. The test groups were submitted to topical exposure to, or intake of, 40% (volume/volume) ethyl alcohol. Biopsy specimens were collected from the middle third of the dorsal tongue at 0, 6, and 12 months, and samples were stained according to the AgNOR technique. Mean number and mean area of AgNOR per nucleus were calculated for 50 basal layer cells and 50 intermediate layer cells. Increases in mean number and mean area of AgNOR per nucleus in intermediate cells were observed at 12 months in the alcohol intake group (P &#60; .05). Results showed that intake of 40% alcohol increased epithelial cell proliferation in the dorsal surface of lingual mucosa. [Copyright &y& Elsevier]

Pinheiro J J V, Freitas V M, Moretti A I S, Jorge A G & Jaeger R G (2004) Histopathology 45, 65–72 Local invasiveness of ameloblastoma. Role played by matrix metalloproteinases and proliferative activity Ameloblastoma is an odontogenic neoplasm characterized by local invasiveness and recurrence. In this study we analysed the role played by matrix metalloproteinases (MMPs) in the local invasiveness of ameloblastoma. We also attempted to establish a relationship between the presence of MMPs and the proliferative activity of ameloblastoma cells. Immunohistochemistry was carried out to detect different MMPs in formalin-fixed paraffin-embedded samples of human ameloblastoma. Immunohistochemistry, however, does not establish whether a given MMP is latent or active. To address this point, we carried out biochemical methods, namely zymography and Western blotting. Our results showed expression of latent and active forms of MMPs 1, 2 and 9 in ameloblastoma. These enzymes may digest bone matrix and release mitogenic factors, which would increase tumour proliferation. This possibility prompted us to study the proliferation of ameloblastoma cells located in close proximity to bone. Silver-stained nucleolar organizer region morphometry revealed that ameloblastoma cells in the vicinity of bone show increased proliferation, when compared with controls. Our results suggest an interdependent mechanism involving MMPs and proliferation of ameloblastoma cells, which may contribute to the local invasiveness of this tumour. [ABSTRACT FROM AUTHOR]

Background: Expression of argyrophilic nucleolar organizer regions (AgNOR) was counted on mucosal epithelium to detect whether the AgNOR count (the number of AgNOR per nucleus) is, for 20 weeks, affected by streptozotocin-induced diabetes mellitus.Methods: Diabetic rats were applied non-denture wearing, non-pressure contact, continuous pressure (0.5, 1.5 or 3.4 kPa) and intermittent pressure (10.5, 33.0 or 81.7 kPa), respectively.Results: In the non-denture wearing or the non-pressure contact group, AgNOR count was almost constant (ranging 1.86-1.92) without significant difference. Under continuous pressure, AgNOR count significantly decreased at earlier stage and finally recovered to the non-pressure contact group. A similar effect of continuous pressure appeared to manifest itself in intermittent pressure, but to a greater degree. Consequently, AgNOR count under intermittent pressure showed no recovery at 20-week stage.Conclusion: : Diabetes mellitus exerted, by itself, no influence on the cellular proliferative activity under continuous pressure, whereas the activity deteriorated under intermittent pressure. [ABSTRACT FROM AUTHOR]

Background: Diagnosis of epithelial dysplasia has traditionally been subjective, and there is a need for a quantifiable and useful test.Methods: In a double blind study, clinical leukoplakias from 52 people were diagnosed for presence (DLK) or absence (NDLK) of epithelial dysplasia using hematoxylin and eosin (H&E) stain as a gold standard criterion, and results were compared against their mean silver stainable nucleolar organizer region (AgNOR) counts. We used mean AgNOR count cut-point of 2.37 from our prior report as the diagnostic threshold (mean >or= 2.37 being DLK and mean < 2.37 being NDLK).Results: The two methods (H&E and AgNOR) disagreed in 37% of the diagnoses. Both NDLK and DLK had high AgNOR counts. P-AgNOR was non-contributory for diagnosing epithelial dysplasia.Conclusions: Mean AgNOR count can be a useful tool in definitive diagnosis of epithelial dysplasia. [ABSTRACT FROM AUTHOR]

To investigate the behavior of nuclear proteins in apoptotic cells, we examined the changes in nucleolin and proteins of the nucleolar organizing region during apoptosis in human osteoblastic cell lines, Saos-2 and MG63. Apoptosis was induced by treatment of these cells with okadaic acid. Proteins prepared from apoptotic cells were subjected to Western blot analysis and a modified Western blot method using silver nitrate. The anti-nucleolin antibody recognized the 110-kDa band and the staining intensity of this band decreased in the proteins prepared from the okadaic acid-treated apoptotic cells. The additional band of an 80-kDa was also detected in the proteins prepared from the apoptotic cells. Two major silver nitrate-stained bands, 110-kDa and 37-kDa, were detected among the proteins obtained from control cells. Like the Western blot analysis, the intensity of the 110-kDa silver nitrate-staining band decreased; an 80-kDa band appeared and its staining intensity increased in the lysate from the okadaic acid-treated cells. The signal intensity of the 37-kDa protein did not change in the sample from the apoptotic cells. In a cell-free apoptotic system, the 80-kDa protein was also detected and the amount of the 110-kDa protein decreased in the extract of Saos-2 cell nuclei incubated with apoptotic cytosol. The change in nucleolin in Saos-2 cells induced to undergo apoptosis was examined by an immunocytochemical procedure using the anti-nucleolin antibody and Hoechst 33342. Nucleolin was visible as dots in nucleoli in the control cells; however, it was not detected in the cells undergoing apoptosis. The dual-exposure view of Hoechst 33342 and anti-nucleolin staining cells confirmed that nucleolin had disappeared from the apoptotic nuclei of Saos-2. [Copyright &y& Elsevier]

Background: Dysplasia is an important feature of leukoplakia. Because agreement among oral pathologists is poor regarding lesional diagnosis, silver stainable nucleolar organizer regions (AgNORs) as replicatory markers may have a place in objectively characterizing dysplasia in tissue specimens.Methods: We studied 41 normal oral epithelia, 51 oral leukoplakia (26 dysplastic, 25 non-dysplastic), and 51 cases of squamous cell carcinoma specimens for their mean AgNOR counts.Results: Mean AgNOR counts increased gradually from normal epithelium to non-dysplastic to dysplastic leukoplakia to squamous cell carcinoma. Using ROC analysis, we determined a mean AgNOR count cut-point (2.37) that can be used to distinguish between dysplastic and non-dysplastic leukoplakia. The test had a sensitivity of 75% and specificity of 83% with area under the curve being 88%.Conclusions: Mean AgNOR count could be a valuable criterion for defining objective parameters for diagnosis/determination of dysplasia distinguishing between dysplastic and non-dysplastic leukoplakia. [ABSTRACT FROM AUTHOR]

Nucleolar organizer regions (NOR) are chromosomal segments in which ribosomal RNA is encoded. AgNOR technique, which reveals these regions, has rarely been used in the diagnosis and preceding the prognosis of pituitary adenoma. The purpose of this study was to determine and evaluate the correlation of hormonal profile with AgNOR counts, the correlation of recurrence with AgNOR counts, and to determine the consistency between the evaluations of the two independent observers. This study covers 33 patients with pituitary adenoma. The slides were stained with hematoxylin and eosin. Silver colloid method was used for NOR, and immunohistochemistry for hormone expressions. Consistency was significant between the two pathologists (for hormonal profile, the Kappa test was used and P<0.001; for AgNOR count, intra-class correlation coefficient was 0.83). There was no significant correlation between mean AgNOR counts and hormone expressions (P>0.05), and there was also no correlation between mean AgNOR counts and tumor sizes (P>0.05). While no difference between recurrent and non-recurrent patients was found with respect to mean AgNOR numbers (P>0.05), nucleolar silver staining in the form of AgNOR clusters was more frequently detected in recurrent cases. [Copyright &y& Elsevier]

The aim of the present study was to examine age-related changes in the proliferative capacity of acinar and ductal cells in labial salivary glands of healthy subjects as reflected by AgNOR and Ki-67 parameters. The study was conducted on 24 postmortem samples of labial salivary glands free from salivary gland tumors/diseases. Samples were equally divided into three age groups: young (mean age 17 yr), adult (mean age 38 yr) and old (mean age 84 yr). The number of profiles of AgNOR (nNOR) and AgNOR profile area per nucleus (TVNOR) were histomorphometrically assessed by CUE-3 automatic image analyzer on 30 nuclei of acinar and intercalated ductal cells in each age group. The percentage of Ki-67 positively stained acinar and ductal cells was evaluated histomorphometrically. Statistical analysis was carried out by one-way ANOVA and Kruskal–Wallis tests. In the acinar cells, nNOR increased significantly with aging (p<0.00001), while TVNOR did not change significantly. In the ductal cells, both nNOR and TVNOR increased significantly (p<0.00001) with a relatively higher increase in TVNOR. Since only isolated acinar and ductal cells demonstrating Ki-67 positive nuclei were found in the different age groups, the overall proliferation index was estimated to be 0%. Thus, it is suggested that age-related changes in AgNOR parameters could reflect changes in the metabolic cell activity rather than changes in their proliferative capacity. In this context, AgNOR results are in accordance with the histomorphometric and physiologic age-related changes occurring in labial salivary glands. [Copyright &y& Elsevier]

The possibility of detection of incipient cellular alterations is central to early diagnosis and to clinician's capacity to discriminate between samples that appear similar on routine preparations. We examined the value of silver-stained nucleolar organizer regions (AgNOR) in detecting radio-induced alterations in a model of squamous epithelium biologically similar to oral mucosa. Morphometry of AgNOR has been proven to be of value in the detection of incipient cellular alterations. This method allows for the quantitative evaluation of lesions induced by high doses of radiation long before they become apparent in routine preparations. We herein examine the capacity of AgNOR to reveal the response to low doses of radiation, closer to the therapeutic or accidental dose to which the epithelium of oral mucosa may be exposed. [ABSTRACT FROM AUTHOR]

(1) Background: ST-elevation myocardial infarction (STEMI) is an inflammatory disease in which neutrophils, macrophages, and lymphocytes accumulate in the ischemic myocardium and have important functions. Nucleolar-organizing regions (NORs) are the site of the ribosomal genes composed of ribosomal DNA and proteins. We aimed to evaluate AgNOR proteins, which have never been studied in patients with STEMI in the literature. (2) Methods: A total of 140 participants (75 with STEMI and 65 volunteers without any diagnosis of acute coronary syndrome) were included in this study. Echocardiography was carried out, and mean AgNOR number and total AgNOR area/total nuclear area (TAA/TNA) were evaluated for all individuals. (3) Results: The mean AgNOR number and TAA/TNA ratio were significantly higher in the STEMI group than the control ( p < 0.001). Statistically significant relations between both TAA/TNA ratio and mean AgNOR number and interventricular septal thickness, fasting blood sugar, creatinine, HDL, hemoglobin (g/dL), WBC (µL/mL), monocytes, neutrophils, and neutrophil/lymphocyte ratio were detected ( p < 0.05). Moreover, a statistically significant relation between LDL (mg/dL) and mean AgNOR number ( p = 0.005) was detected. (4) Conclusion: Both AgNOR protein amounts increase depending on the hypoxia that occurs in STEMI. The AgNOR proteins may thus be promising markers in STEMI.

Argyrophilic nucleolar organizer region (AgNOR) technique: a helpful tool for differential diagnosis in urinary cytologyThe aim of this study was to investigate whether the AgNOR technique could be helpful for the cytologic diagnosis of neoplastic and non-neoplastic urinary tract lesions. We analysed the AgNOR pattern in urinary cytology in samples from 70 patients. In every case the average number of silver precipitations per nucleus was counted and the range between the minimum and maximum AgNOR value calculated. Furthermore we noted whether the AgNOR precipitations had a homogeneous or heterogeneous distribution. The diseases were classified in three groups: non-neoplastic lesions, low grade and high grade carcinoma. Linear discriminant analysis (with jack-knife procedure) was performed with the AgNOR parameters as independent variables. The final diagnosis of each patient had been established by histological analysis of bladder biopsies. We obtained a correct classification in 84.3% of the cases. All patients with normal or reactive lesions were correctly classified and only two cases of low grade malignancy were erroneously diagnosed as non-malignant. Five high grade neoplasms had been classified as low grade and four low grade carcinomas had been over-diagnosed as high grade neoplasms. We conclude that a combined qualitative and quantitative AgNOR analysis can be useful in the differential diagnosis of urinary cytology. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The cellular changes leading to carcinoma of the lip are still not completely understood. This study was carried out on 44 malignant and potentially malignant lesions of the lower lip [30 squamous cell carcinomas (SCC), 7 actinic cheilitis, 3 leukoplakias, and 4 nodal metastases from lower lip SCC]. Silver-stained nucleolar organizer regions (AgNORs) and the immunohistochemical expression of proliferating cell nuclear antigen (PCNA), p53, and c-myc were evaluated on formalin-fixed, paraffin-embedded sections. The results indicate that the size and numbers of AgNORs and the percentage of PCNA-positive cells are sensitive parameters for discriminating between potentially malignant lesions and SCC, and for the prognostic sub-typing of lower lip SCC. Furthermore, while p53 positivity was found more frequently in high-grade carcinomas, p53-positive cellular clones were also found in some potentially malignant lesions, a finding probably related to ultraviolet-related cellular damage. These p53-positive lesions could be considered at higher risk of progression to malignancy than the p53-negative ones, although there is no evidence for this as yet. c-myc positivity was found only in some high-grade carcinomas and metastases, and appeared correlated with the later phases of lip carcinogenesis. The combined evaluation of the proliferation status, together with the changes in p53 and c-myc oncoproteins, might constitute useful markers for the prognostic evaluation of potentially malignant, as well as malignant, lesions of the lip. [ABSTRACT FROM AUTHOR]

Reduction in receptors for epidermal growth factor (EGF) in cancers appears to be one of the principal mechanisms through which peptide hormone analogs can inhibit tumor growth. In this study, hamsters with nitrosamine-induced pancreatic cancers were treated for 8 weeks with bombesin/gastrin-releasing peptide (GRP) antagonist RC-3095, somatostatin analog RC-160 or the luteinizing hormone-releasing hormone antagonist Cetrorelix, using sustained delivery systems releasing 20, 35 and 20 μg analog/ day respectively. To establish the pattern of changes in the number and affinity of EGF receptors on tumors, groups of animals were sacrificed at regular intervals during therapy. Chronic treatment with RC-3095 or Cetrorelix resulted in an early (day 10) and sustained reduction (71% or 69% respectively) in EGF receptors on pancreatic tumors. In contrast, RC-160 decreased receptor concentration by 60% only after 20 days. Among the histological characteristics of proliferation, the decrease in argyrophilic nucleolar organizer regions, but not apoptotic and mitotic indices, showed a correlation with the fall in EGF receptors. The concentration of the receptors returned to the control level 4 days after cessation of chronic treatment with RC-3095. The effect of single injections of RC-3095, RC-160 and Cetrorelix on EGF receptors was also investigated. RC-160 decreased the number of EGF receptors on pancreatic cancers by 31% 3 h after administration, but the receptors had returned to normal level at 6 h. RC-3095 and Cetrorelix caused a 67% and 59% decline, respectively, in EGF receptors only 6 h after injection and the concentration of receptors remained low for 24 h. Thus, the pattern of down-regulation of EGF receptors in pancreatic cancers appears to depend on the peptide used for therapy. Since the antitumor effect may be the result of the fall in EGF receptors in cancers, information on the time course of changes in these receptors during treatment with these analogs may lead to an improvement in therapeutic regimens. [ABSTRACT FROM AUTHOR]

Odontogenic keratocysts are occasionally (4-5%) associated with the nevoid basal cell carcinoma syndrome, a pleiotropic, autosomal disorder presenting a spectrum of developmental abnormalities and a predisposition for the development of different neoplasms. The aim of this study was to establish whether keratocysts showing clinically aggressive behavior associated with nevoid basal cell carcinoma syndrome reflect differences in cellular proliferation rate and/or in the expression of oncoproteins and tumor suppressor genes. For this reason, formalin-fixed paraffin-embedded sections of odontogenic keratocysts associated with the nevoid basal cell carcinoma syndrome (16 cases) and sporadic odontogenic keratocysts (16 cases) were compared for expression of proliferating cell nuclear antigen (PCNA) and p53, bcl-2, and bcl-l (cyclin D1) onco-proteins. Most of the epithelial lining of odontogenic keratocysts associated with the nevoid basal cell carcinoma syndrome showed nuclear immunopositivity for p53 protein and overexpression of cyclin Dl with various degrees of staining intensity. All sporadic odontogenic keratocysts were negative for p53 and cyclin Dl. The expressions of bcl-2 oncoprotein were found to be substantially similar between the two groups of lesions, with a cytoplasmic immunopositivity localized only in the resting reserve basal layer of the epithelium. PCNA expression showed no statistically significant difference between the two groups of lesions. In conclusion, the finding of cyclin Dl and p53 overexpression in odontogenic keratocysts associated with the nevoid basal cell carcinoma syndrome could be considered a hallmark of a mutated cellular phenotype, thus leading to the hypothesis that their aggressive clinical behavior could be due to a dysregulation of the expression of cyclin Dl and p53 proteins, involved in a check-point control of cellular proliferation. [ABSTRACT FROM AUTHOR]

Hamster cheek pouch mucosa is an accepted model of oral carcinogenesis. We herein examined the value of morphometric evaluation of silver-stained nucleolar organizer regions (AgNOR) in the detection of epithelial foci in malignant transformation following dimethyl-1,2-benzanthracene-induced carcinogenesis of hamster cheek pouch. AgNOR-related parameters were analyzed at different stages of the process of carcinogenesis (control epithelium, epithelium with no unusual microscopic features, "dysplastic" epithelium, exophytic and endophytic carcinomas). Morphometric evaluation of AgNOR revealed incipient cellular alterations which were not evident in routine preparations and contributed to the characterization of different stages of carcinogenesis in this model. [ABSTRACT FROM AUTHOR]

The quantification of argyrophilic nucleolar organizer regions (AgNOR) was performed in 34 cases of adenoid cystic carcinoma (ACC) to determine (1) whether AgNOR count correlates with its different histologic grades pertinent to prognosis, and (2) whether AgNOR counts can offer any additional prognostic advantage over histologic grading. According to SZANTO et al.'s histologic grading criteria (4), 12 cases were Grade 1, 7 cases Grade 2, and 15 were Grade 3. Patients were divided into 20 favorable cases (without metastases) and 14 unfavorable cases (with metastases). Although most Grade 3 tumors had high AgNOR counts (&ges;4) and Grade 1 tumors with low (<4) AgNOR counts outnumbered those with high AgNOR counts, considerable overlap of AgNOR values in different grades was observed. However, all unfavorable cases had high AgNOR counts regardless of their histologic grades, suggesting that the metabolic alterations associated with the malignancy level of ACC may partly be portrayed by the AgNOR count, irrespective of the histologic appearance. Cumulative survival rates of Grade 1 tumors and of tumors with low AgNOR counts were better than those of Grade 3 tumors and those with high AgNOR counts. Within the limited number of cases in this series the AgNOR count exhibits a potential for identifying some aggressive ACCs that cannot be detected by histology alone. [ABSTRACT FROM AUTHOR]

To investigate the process of carcinogenesis in gastric cancer, we studied the histological features and cell kinetics in the gastric mucosa of N-methyl- N′-nitro- N-nitrosoguanidine (MNNG)-treated rats. Samples of gastric mucosa from both MNNG-treated and control rats were histologically examined by staining with nucleolar argylophilic nonhistone (AgNOR) proteins, and their ornithine decarboxylase (ODC) activity was determined every 2 months for 10 months. In 40% of the MNNG-treated rats, atrophy of the gastric mucosa was observed after 2 months, followed by adenomatous proliferation. More AgNOR-positive granules were found in the pyloric glands than in the fundic glands, and the total number of positive granules increased over time. Cancerous and hyperplastic lesions preferentially developed in the pyloric glands and showed significantly more AgNOR-positive granules than the normal mucosa. After 6 months the ODC activity in the MNNG-treated rats was significantly higher than that in the control rats. These results thus suggest that the pyloric glands have a high growth activity, while in addition, adenomatous proliferation is a characteristic pathological feature of precancerous lesions in the stomach in MNNG-treated rats. [ABSTRACT FROM AUTHOR]

Immunostaining of the proliferating cell nuclear antigen (PCNA) provides important information about cell kinetics and is easily performed on routinely obtained formalin-fixed, paraffin-embedded materials. We report herein the results of a retrospective study on PCNA staining in esophageal cancer undertaken to determine its significance. As this study indicated that immunoreactivity was preserved in specimens fixed within 24 h, only 31 specimens from surgical patients were available for this investigation. The mean PCNA index of the patients without invasion to the adventitia (35.7±17.9) was significantly lower than that of those with invasion to the adventitia or neighboring structures (49.7±14.5), while the PCNA index did not correlate with other clinicopathologic parameters such as histologic type, lymph node metastases, or prognosis. However, when an analysis of PCNA staining was combined with an analysis of argyrophilic nucleolar organizer region (AgNOR) staining, a correlation with prognosis was found. In fact, seven patients with a high PCNA index (≧44) and AgNOR count (≧6) had a significantly poorer prognosis than the remaining 22 (P=0.0014), and six of these seven patients died within 2 years. These results indicate that this combined evaluation may be useful for the identification of patients with a poor prognosis among those undergoing surgery for esophageal squamous cell carcinoma. [ABSTRACT FROM AUTHOR]

- A silver colloid technique to identify argyrophilic nucleolar organizer region associated protein (AgNOR) was applied to 43 cases of intrahepatic bile duct carcinoma (cholangiocarcinoma, CC), 2 with bile duct adenoma (BDA), 5 with focal duct epithelial hyperplasia (FEH) associated with hepatolithiasis, 15 with posthepatitic ductular proliferation (PHDP) associated with massive or submassive hepatic necrosis and 20 of normal liver. In the present study, only discrete, easily counted black dots within nuclei and silver-stained nucleolus were counted under a magnification of X 400 without oil-immersion objectives. The mean AgNOR count of CC was significantly higher than those of BDA, FEH, PHDP and normal controls (P>0.05, P>0.001, P>0.01, and P>0.001, respectively). Among CCs the mean AgNOR numbers of papillary adenocarcinoma (pap), moderately (tub2) and poorly differentiated (por) adenocarcinoma, and adeno-squamous carcinoma (as) were significantly higher than that of normal controls (P > 0.01, P > 0.001, P > 0.001 and P > 0.001, respectively), and those of tub2, por and as were also significantly higher than those of BDA, FEH and PHDP, whereas that of well differentiated tubular adenocarcinoma (tub 1) was not different from those of BDA, FEH, PHDP and normal controls, and that of pap was not different from those of BDA, FEH and PHDP. The mean numbers of AgNORs of BDA and FEH were not different from that of normal controls, whereas that of PHDP was significantly higher than that of normal controls (P > 0.01). Interestingly, the mean AgNOR counts of tubular adenocarcinoma were increased with histologic tumor grades. All cases with AgNOR counts of more than 2.24 had CC. Furthermore, not only quantitative but also striking qualitative abnormalities of AgNORs were seen in CCs. Large and/or irregularly shaped AgNORs without uniformity in size and density were characteristic for CCs, even in well differentiated adenocarcinoma, in contrast to the small, round, regular AgNORs seen in normal bile duct epithelium and rather large but regular AgNORs seen in benign bile duct lesions. These results indicate that the enumeration of AgNORs in various bile duct lesions is useful to identify moderate and high grade CCs and to evaluate tumor grade, but not useful to discriminate well differentiated adenocarcinoma from benign lesions. In case of normal or equivocal AgNOR counts, the presence of large and/or irregularly shaped AgNORs without uniformity in size and density would favor a diagnosis of carcinoma rather than benign counterparts. [ABSTRACT FROM AUTHOR]

Background: Odontogenic keratocyst (OKC) is a clinical entity with characteristic microscopic features, high growth potential and propensity to recur. Aggressive behavior and higher tendency for recurrence have been attributed to greater proliferative activity of epithelial lining. The incidence of recurrence in various reported series ranges from 2.5% to 62%. Objectives: The objective of the study was to investigate the clinical behavior of OKC by evaluating p53, MDM2 expression, AgNOR staining and to ascertain if the expression of these markers correlate with the clinical outcome and tendency for recurrence. Materials and Methods: All recurrent and nonrecurrent OKCs from the archives were included, and sections were subjected to AgNOR staining, p53 and MDM2 immunohistochemical staining. Results and Conclusion: There was a significant difference in the staining pattern of MDM2 and AgNOR in the recurrent group as compared to the nonrecurrent group. The higher expression of these markers in recurrent lesions may be important in order to consider additional surgical interventions to improve prognosis. [ABSTRACT FROM AUTHOR]

Background and Objectives : It is of great importance to obtain information about the severity of ischemic damage and duration of testicular torsion for an effective treatment strategy. Nucleolar-organizing regions (NORs) are sites of the ribosomal genes composed of ribosomal DNA and proteins. Post-silver staining NORs are termed "AgNOR". Since AgNORs clearly reveals the self-renewal potential of cells damaged in ischemic events, we performed the current study. Materials and Methods : The study was carried out in four groups as control, sham, early, and late T/D. In the surgical groups, testes were corrected after a 4-h ischemia period. Testicular tissue samples were taken on the third day after detorsion in group 1, 2, 3, and on the tenth day after detorsion in group 4. TUNEL and silver stainings were applied to all samples. Results: The differences were significant among the groups for both mean AgNOR number and total AgNOR area/total nuclear area (TAA/TNA). Moreover, the differences between control and early torsion-detorsion (T/D), between control and late T/D, between sham and early T/D, between sham and late T/D, and between early T/D and late were statistically significant for AgNOR amount. Furthermore, statistically significant differences among the groups for an average number of apoptotic cells per tubule and the percentage of apoptotic tubule values were detected. Discussion : The apoptotic index gives the ratio of cells that are damaged and will die in a programmed way and cells that remain intact, rather than show the viability of the returning testicle. However, by measuring cells that regenerate with AgNOR, we can show not only those that survive but also cells that can repair themselves. Conclusion : AgNOR proteins are usable for the early observation of ischemic injury levels. The amount of AgNOR protein can enlighten us about the extent of testicular damage after T/D treatment. It may also help the physician in the development of effective treatment strategies for cases.