Background:Micronucleus (MN) represents small, additional nuclei formed by the exclusion of chromosome fragments or whole chromosomes lagging at mitosis. MN rates, therefore, indirectly reflect chromosome breakage or impairment of the mitotic apparatus. During the last few decades, micronuclei (“MNi”) in oral exfoliated epithelial cells are widely used as biomarkers of chromosomal damage, genome instability and cancer risk in humans. However, until now only little attention has been given to the effect of different staining procedures on the results of these MN assays.Aim:To compare the MNi frequencies in oral exfoliated epithelial cells using three different stains, i.e.,Feulgen stain, Papanicolaou stain (Pap) and hemotoxylin and eosin stain (H and E).Materials and Methods:Oral exfoliated cells from 45 cases of potentially malignant disorders (15 oral submucous fibrosis, 15 lichen planus and 15 leukoplakia) and 15 controls with healthy mucosa, were taken and MNi frequencies (No. of MNi/1000 cells) were compared using three different stains.Results:Mean MNi frequency in cases was found to be 3.8 with Feulgen stain, 16.8 with PAP and 25.9 with H and E. In controls, mean MNi frequency was 1.6 with Feulgen stain, 7.7 with PAP and 9.6 with H and E stain. Statistically significant value (P < 0.01) were observed when the three stains were compared together using Kruskal Walli's ANOVA test.Conclusion:Feulgen being a DNA-specific stain gave the least counts, although statistically significant results from the comparison of MNi frequency between cases and controls were obtained with all the three stains.

Renal allograft biopsy is the gold standard for diagnosis of rejection. Incorporation of C4d as a marker for humoral rejection is a major addition for Banff Schema, 2005. We evaluated the pattern of C4d staining in indicated renal allograft biopsies from January 2005 to December 2009. Of the 67 biopsies analyzed, 21 were C4d-positive. They were 11 cases of acute rejection, seven chronic rejection and one biopsy each of acute tubular necrosis, BK virus nephropathy and normal biopsy. Morphologic features like peritubular capillary dilatation, tubulitis and interstitial inflammation were seen more frequently in C4d-positive biopsies and this was statistically significant. C4d positivity was noted in 50% of the chronic rejection cases indicating a humoral component in the pathogenesis of chronic rejection. There was no significant difference in the serum creatinine levels of C4d-positive and -negative patients, either at the time of biopsy or during the follow-up. This study supports the role of C4d immunostaining in confirming histologically diagnosed acute and chronic humoral rejections and in detecting histologically unsuspected cases.

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To ensure adequate wear resistance on some of the nuclear reactor components made of Zircaloy-2, a uniform thick buff oxide layer is desirable. Commonly used methods to evaluate oxide thickness (i.e., metallography and weight gain) have certain limitations. In this paper, results of eddy current (ECT) monitoring as a function of oxide layer thickness (determined metallographically) on Zircaloy-2 surface have been reported. A linear correlation between ECT response and oxide layer thickness has been established.