a study of distribution and number of nucleolar organizer region (nor)associated proteins in gastritis and gastric carcinoma

introduction: nucleolar organizer region associated proteins are a group of non histone proteins which act in r-dna transcription and r-rna processing. the amount of these proteins increase in transition from g1 to s phase in cell cycle. hence these proteins can show the proliferative index of the cells. material & methods: for this purpose 40 patients (30 gastritis, 10 carcinoma) with average age of 45 years were chosen from pathology file of khatam al anbia of zahedan and shiraz namazi hospitals during the years 1999-2001. paraffin blocks were cut with 3-5 um thickness andstained with h-e and colloidal silver nitrate. the number of nor were counted blindly by two persons. results: pearson correlation test showed significant correlation of nor counting (p< 0.001, r = 96) by two persons. mann-whitney test showed significant difference of nor between gastritis and carcinoma.the shape and distribution of nor in gastritis looked like diffuse black dots in nuclei,but in neoplastic cells the number of nor were increased and theirdistribution differed extensively. conclusion: it seems that nor number is a reliable indicator of cellular proliferation in carcinoma of the stomach.