Assessment of vascularity and blood-tissue barrier was performed by sequential scintigraphy in 43 patients with brain tumours. The blood-tumour barrier was evaluated by use of 99mTc-pertechnetate, and vascularity using 99mTc-labelled red blood cells. Three groups of tumours were found: tumours with low vascularity and permeable barrier, tumours with high vascularity and permeable barrier, and t...

To determine whether healing arterial wall accumulation of low density lipoproteins (LDL) is mediated by the high affinity LDL receptor, normocholesterolemic rabbits were injected with 125I-LDL, 99mTc-LDL, or the reductively methylated analogs of these compounds (125I-MeLDL, 99mTc-MeLDL), 1 month after balloon catheter deendothelialization of the abdominal aorta. If the mechanism of accumulatio...

Platelets produce a range of bronchoconstrictor mediators. Measurements of plasma factors have implicated platelet activation in allergic asthma, and sensitised guinea pigs challenged with ovalbumin show pulmonary platelet aggregation accompanying bronchoconstriction. To investigate this further we injected autologous platelets labelled with indium 111 and red cells labelled with technetium 99m...

The new histidine derivative 3-[1-[3-(9H-fluoren-9-ylmethoxycarbonylamino)-propyl]-1H-imidazol-4-yl]-2-(3-trimethylsilanyl-ethylcarboxyamino)-propionic acid methyl ester (7) has been prepared via alkylation of the histidine urea derivative (7S)-5,6,7,8-tetrahydro-7-(methoxycarbonyl)-5-oxoimidazo-[1,5-c]-pyrimidine (2) with Fmoc-protected 3-iodopropyl-amine, followed by ring opening with 2-trime...

Following the current hypothesis that acute schizophrenic psychotic illness is associated with a striatal 'hyperdopaminergic state', presynaptic integrity and dopamine transporter (DAT) density in first-episode, neuroleptic-naive schizophrenic patients was measured by single-photon-emission-tomography (SPECT) and compared with that in healthy control subjects. A new SPECT-ligand for assessment ...