Diagnostic yield in CT-guided stereotactic biopsy of gliomas

✓ Twenty-seven patients underwent 29 computerized tomography (CT)-guided stereotactic biopsy procedures for untreated or recurrent malignant astrocytomas. Biopsies were obtained from the hypodense center, enhancing margin, and hypodense periphery as seen on contrast-enhanced CT scans, with diagnostic yields of (number of biopsies yielding tumor/number of biopsies obtained): 34/61 (56%), 68/101 (67%), and 8/22 (36%) from these three zones, respectively. Although tumor was identified in all three zones, diagnostic yield was significantly higher in the hypodense center and enhancing margin. Comparison of patients with untreated tumors to those with recurrent tumors demonstrated no statistical difference in tumor distribution, although there was a trend toward a higher yield from the hypodense periphery in the recurrent tumor group. Tumor was found up to 15 mm beyond the CT-enhancing margin, in addition to extending beyond the area of abnormality on T2-weighted magnetic resonance images. These findings suggest that serial stereotactic biopsies should be targeted to the hypodense center and enhancing margin for improved diagnostic yield. Biopsy material obtained from the hypodense periphery that demonstrates tumor also indicates that a tumor volume beyond the confines of the CT-enhancing margin should be considered when calculating dosimetry for interstitial radiation.</jats:p

Palladium-catalyzed cross-coupling reactions and electrocyclizations - efficient combinations for new cascade reactions

Palladium-catalyzed cross-coupling reactions and electrocyclic transformations as well as cycloadditions can efficiently be combined in one-pot sequences to build up complex molecules from simple precursors. 1,3-Dicyclopropyl-1,2-propadiene (1) could be coupled to various aryl halides, and the 1,3,5-hexatrienes resulting after rearrangement were trapped with different dienophiles. Further exploration of the highly reactive building block bicyclopropylidene (8) demonstrates the combinatorial potential of the two reaction modes in terms of two different three-component reactions, and even a novel four-component reaction was readily developed. Additional increase of complexity was gained by combining an intramolecular Heck reaction with consecutive trapping by 8, which can be carried out with or without 6pi-electrocyclization. Finally a Stille-Heck-coupling sequence of substituted 2-bromocycloalkenyl triflates with functionally substituted alkenylstannanes and acrylic esters led to highly substituted 1,3,5-hexatrienes. which smoothly underwent 6pi-electrocyclization at elevated temperatures to yield bi- and tricyclic skeletons. With this methodology at hand, a new versatile access to steroid-analogues with a diene moiety in the B ring and a functionality at C-7 was developed. (C) 2003 Elsevier B.V. All rights reserved

Generalverkehrsplan fuer die Gemeinde Stuhr Teil 1: Analyse des Individualverkehrs

SIGLETIB: AC 8665 (1) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman