How should we count AgNORS? Proposals for a standardized approach

Abstract

There is interest currently in the AgNOR technique, for NOR-associated proteins. In some cases, this technique enables the distinction to be made between certain grades of malignancy and may enable prognostic assessment. This paper attempts to suggest a standardized means for the enumeration of NORs in histological sections. Attention should be paid to rigorous technique and careful resolution of intranucleolar AgNOR dots. The timing of the reaction and fixation methods are also most important.

Multidrug resistance 1 gene expression and AgNOR in childhood acute leukemias

“…AgNORs counted by Technique 1 of Crocker [8] in different FAB categories are given in Fig. 6.The mean AgNOR count in acute lymphoblastic leukemia was lowerer than the mean AgNOR count in acute myeloid leukemia.…”

“…The leukemias were classifi ed according to FAB criteria [10,11]. AgNOR staining was carried out on one smear from each case using the silver staining method of Crocker et al [8]. AgNORs are visualized as black intranuclear dots.…”

“…Five hundred cells from each smear were examined under oil immersion objective, the number of AgNOR dots counted and the mean number per nucleus determined. The enumeration of AgNORS was done by method of Crocker et al [8]. MDR1 immunostaining [12] was carried out on smears using the APAAP technique.…”

“…Nucleolar organizer regions (AgNORS) are loops of DNA relating to the production of precursor of ribosomal RNA -AgNOR is a simple, inexpensive and reliable method of evaluating proliferative activity of tumors [7,8].…”

Avaliação da técnica de coloração AgNOR em testículos de ovinos

“…Zootec., v.67, n.2, p.447-454, 2015 estudo da proliferação celular, com emprego de técnicas de coloração para fins de estimar o prognóstico e tratamento para as afecções do aparelho reprodutor (Madewell, 2001). A coloração das proteínas argirofílicas, presentes nos cromossomos no estádio de interfase, relacionadas às regiões organizadoras de nucléolo (NORs), pode ser obtida pela técnica denominada de AgNOR, usada em preparações citológicas ou histológicas para a obtenção da taxa de proliferação celular (Crocker et al, 1989;Lindner, 1993) em que, em células normais, as NORs são usualmente organizadas de forma clara em número igual ou maior a um, restritas ao nucléolo, e, em células neoplásicas, as NORs se desagregam do nucléolo e tendem a se dispersar pelo núcleo (Ofner e Schmid, 1996).…”