Mapping of brain tissue hematocrit in glioma and acute stroke using a dual autoradiography approach.

Hematocrit (Hct) determines the ability of blood to carry oxygen. While changes in systemic Hct are known to impact stroke or tumor control, changes in local (tissue) Hct (tHct) induced by these diseases have however received little attention. In this study, we evaluate tHct in acute stroke and in glioma models using a new approach to map tHct across the brain, a dual isotope autoradiography, based on injections of 125I-labeled albumin and 99mTc-lalbeled red blood cells in the same animal. For validation purpose, tHct was mapped in the rat brain (i) under physiological conditions, (ii) following erythropoietin injection, and (iii) following hemodilution. Then, tHct was then mapped in stroke (middle cerebral artery occlusion) and tumor models (9LGS and C6). The mean tHct values observed in healthy brains (tHct = 29 ± 1.3%), were modified as expected by erythropoietin (tHct = 36.7 ± 2.6%) and hemodilution (tHct = 24.2 ± 2.4%). Using the proposed method, we observed a local reduction, spatially heterogeneous, in tHct following acute stroke (tHct = 19.5 ± 2.5%) and in both glioma models (9LGS: tHct = 18.5 ± 2.3%, C6: tHct = 16.1 ± 1.2%). This reduction and this heterogeneity in tHct observed in stroke and glioma raises methodological issues in perfusion imaging techniques where tHct is generally overlooked and could impact therapeutic strategies.

[Importance of the systematic cytologic examination of breast secretions: 60 cancers diagnosed in 2120 discharges examined]. / Intérêt de l'examen cytologique systématique des sécrétions mammaires: 60 cancers diagnostiqués sur 2 120 écoulements examinés.

The systematic collection of breast secretions by manual expression of the breast and nipple in 2 120 patients examined for breast diseases has led to the following results: 529 (25%) disclose epithelial papillary hyperplasia, 136 of which underwent surgical control. Epithelial hyperplasia without cellular atypias was found in 9 fibroadenomas, 42 fibrocystic diseases, 29 papilloma/papillomatosis and 21 cancers. Atypical or malignant hyperplasia was observed in 42 cases. Out of 60 cancers, thus investigated, 31 (51%) had malignant cells in such induced nipple discharge, 8 (13%) atypical cells and 21 (35%) concomitant papillary hyperplasia. Systematic cytological examination of breast secretion allows to control intraductal epithelial hyperplasia and to eventually disclose malignant tumor.