Cerebral cortical dysplasia is an uncommon pathological substrate of severe intractable childhood epilepsy, sometimes treated by hemispherectomy. Neuropathological findings include abnormal gyrus formation, loss of cortical lamination, unusual giant neurons and 'balloon cells' of indeterminate histogenesis similar in appearance to neoplastic gemistocytic astrocytes. In order to investigate the proliferative potential of 'balloon cells', we used Crocker's silver impregnation technique to demonstrate nucleolar organizer regions (AgNORs) involved in cellular proliferation, together with immunohistochemical evaluation of proliferating cell nuclear antigen (PCNA) expression. Balloon cells (5.56 +/- 0.24) had significantly (P < 0.001) greater AgNOR numbers than reactive astrocytes (3.89 +/- 0.15), neurons (2.30 +/- 0.13) or giant neurons (4.26 +/- 0.20). However, when corrected for nuclear size, results showed that 'balloon cells' (0.093 +/- 0.006) had significantly (P < 0.001) fewer AgNORs/square micrometre of nuclear area than reactive astrocytes (0.225 +/- 0.016) and had significantly (P < 0.001) more AgNORs/square micrometre of nuclear area than normal (0.048 +/- 0.003) or giant neurons(0.054 +/- 0.003). On the assumption that astrocytes are typical interphase cells and that normal neurons are post-mitotic, the results suggest that 'balloon cells' are unlikely to be undergoing proliferative activity and, when adjusted for nuclear size, the number of AgNORs/unit of nuclear area is more reflective of cellular ploidy than of proliferative activity in non-neoplastic neural tissues. The virtual absence of PCNA expression by 'balloon cell' nuclei supports such an interpretation of the AgNOR results.

HistoryVolume 42, Issue 146 p. 197-204 THE SELECTION OF STUDENTS FOR HISTORY HONOURS: II C. PETHERICK, C. PETHERICK Wimbledon High SchoolSearch for more papers by this authorARNOLD FELLOWS, ARNOLD FELLOWS Chigwell SchoolSearch for more papers by this authorL. O. D. BAKER, L. O. D. BAKER The Leys School, CambridgeSearch for more papers by this authorM. T. GHERNIAVSKY, M. T. GHERNIAVSKY Christ's Hospital, HorshamSearch for more papers by this authorL. W. HERNE, L. W. HERNE Warwick SchoolSearch for more papers by this authorM. G. KEY, M. G. KEY Bournemouth School for GirlSearch for more papers by this authorM. M. BURKE, M. M. BURKE Bournemouth School for GirlSearch for more papers by this author C. PETHERICK, C. PETHERICK Wimbledon High SchoolSearch for more papers by this authorARNOLD FELLOWS, ARNOLD FELLOWS Chigwell SchoolSearch for more papers by this authorL. O. D. BAKER, L. O. D. BAKER The Leys School, CambridgeSearch for more papers by this authorM. T. GHERNIAVSKY, M. T. GHERNIAVSKY Christ's Hospital, HorshamSearch for more papers by this authorL. W. HERNE, L. W. HERNE Warwick SchoolSearch for more papers by this authorM. G. KEY, M. G. KEY Bournemouth School for GirlSearch for more papers by this authorM. M. BURKE, M. M. BURKE Bournemouth School for GirlSearch for more papers by this author First published: October 1957 https://doi.org/10.1111/j.1468-229X.1957.tb02283.xRead the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat Volume42, Issue146October 1957Pages 197-204 RelatedInformation

A polarographic assay for khellin in serum has been developed. The method has been applied to in vivo studies and has been found adequate to show the presence of khellin in small amounts (0–10 μg./ml.). The average recovery of khellin was 90 per cent, the precision of the method varying with the blood level. It was ±5 per cent at a level of 10 μg./ml. and was ±40 per cent at 1 μg./ ml.