Biochemical and autoradiographic study of cerebral protein synthesis with [18F]-and [14C]fluorophenylalanine.

Fluorine-18-labeled ortho or para isomers of L-fluorophenylalanine were used in double-label experiments together with L-[3H]phenylalanine for amino acid incorporation into cerebral proteins of Mongolian gerbil brain. It was demonstrated by qualitative regional comparison of the 18F and 3H autoradiographic images that L-p-[18F]fluorophenylalanine is incorporated into proteins and exhibits a regional cerebral protein synthesis pattern. To a minor extent, L-p-fluorophenyl[3-14C]alanine and L-o-[18F]fluorophenylalanine are hydroxylated in vivo to form labeled tyrosine or tyrosine analogues that are incorporated into cerebral proteins as well.

Glucocorticosteroid treatment of vasogenic oedema.

The components of vasogenic oedema associated with brain tumours were investigated in human biopsy material sampled from tumour and peritumoural tissue intraoperatively. Sixty patients with glioblastomas, gliomas, meningiomas and metastases, which had been treated with dexamethasone prior to surgery were employed for tissue measurements of water, electrolyte, haemoglobin, serum protein and dexamethasone concentrations. The quantification of serum proteins was achieved with the method described by Bodsch et al.

Metabolites of 2-deoxyglucose in rat brain at 12-24 h: bounds on kinetic constants.

Activities of 2-deoxy-D-glucose and its metabolites in rat brain were examined at 12, 16, 20, and 24 h after intraperitoneal injection of 14C-labeled 2-deoxy-D-glucose. Plasma radioactivity was monitored for 2 h before each of these determinations. As proportion of total brain radioactivity, 2-deoxy-D-glucose decreased monotonically from the unexpectedly high value of 22% at 12 h to 11% at 24 h after injection, 2-deoxy-D-glucose 6-phosphate decreased monotonically from 69% at 12 h to 23% at 24 h, and unphosphorylated products (of high and low molecular weight) increased from 10% at 12 h to 64% at 24 h.

Factors responsible for the retention of fluid in human tumor edema and the effect of dexamethasone.

The components of vasogenic edema associated with brain tumors were investigated in human biopsy material sampled from tumor and peritumoral tissue during neurosurgical operations. Tissue from 60 patients with glioblastomas, gliomas, meningiomas, and metastases who had been treated with dexamethasone prior to surgery was used for measurement of water, electrolyte, hemoglobin, serum protein, and dexamethasone concentrations. In all samples except metastases, positive correlations were obtained between water content and both serum protein levels and sodium content in tumors and peritumoral edema, suggesting that these components simultaneously determine forces for extravasation of plasma-derived edema fluid.

Triple-tracer autoradiography of cerebral blood flow, glucose utilization, and protein synthesis in rat brain.

A triple-tracer autoradiographic technique is described that permits the simultaneous measurement of cerebral blood flow, glucose consumption, and protein synthesis using 131I-iodoantipyrine (131I-IAP), [14C]deoxyglucose ([14C]DG), and 3H-amino acids as radioactive tracers. Autoradiographic differentiation between isotopes was performed by taking advantage of different half-lives, solubility of labeled tracers in a wash solution, and sensitivity of the photographic material to disintegrations of the radionuclides. Blood flow autoradiograms using 131I-IAP were obtained by immediate exposure of brain sections to Kodak NMB film for 24 h.