For many compounds (neurotrophic factors, antibodies, growth factors, genetic vectors, enzymes) slow diffusion in the brain severely limits drug distribution and effect after direct drug admistration into brain parenchyma.We investigated convection as a means to enhance the distribution of the large and small molecules 51In-labeled trserrin (111In-Tf; Mr, 80,00)

The high rate of GBM formation (82%) following a therapeutic dose of WBRT in nonhuman primates indicates that radioinduction of these neoplasms as a late complication of this therapy may occur more frequently than is currently recognized in human patients. The development of these tumors while monitoring the monkeys' conditions with clinical and serial MR imaging studies, and access to the tumor and the entire brain for histological and molecular analyses offers an opportunity to gather unique insights into the nature and development of GBMs.

Peripheral benzodiazepine receptors (PBR) are increased in gliomas and augmented glucose metabolism is seen in malignant brain tumors. We investigated the relationship between PBR density (Bmax) and glucose utilization rate (GUR) in 17 patients with cerebral gliomas of different grades. PBR Bmax was assessed by [3H]PK-11195 in vitro binding in surgical specimens and GUR was measured by Positron Emission Tomography with [18F]2-Fluorodeoxyglucose before the surgery. In untreated tumors there was a positive correlation between PBR Bmax and GUR (2r = 0.84). This correlation was not observed in patients who had been treated with radiation and/or chemotherapy prior to surgery (r2 = 0.13). In addition, in untreated patients, the increase in PBR density and GUR appeared to be related to the degree of malignancy.