QUANTIFICATION OF NUCLEOLAR ORGANIZER REGIONS IN CANINE PERIANAL GLAND TUMORS

The proliferative activity in 28 canine perianal gland tumours was exa mined by the quantitative evaluation of the nucleolar organiser region s associated with argyrophil proteins (AgNORs). These regions were sta ined with a specific silver stain and quantified directly by light mic roscopy and by computerised image analysis. The relationships between some of the parameters used (the number of AgNORs per nucleus, the are a of AgNORs per nucleus and the ratio of the area of AgNORs to the are a of the nucleus) were also examined in relation to the histopathologi cal grades of the tumours. All the parameters showed a high correspond ence with the tumours' proliferative activity, and the ratio of the ar ea of AgNORs to the area of the nucleus was the most significantly cor related with the tumours' histological patterns.