BACKGROUND Positron-emission tomography and the radioligand [11C](R)-PK11195 have been used for the imaging of the translocator protein (TSPO) and applied to map microglia cells in the brain in neuropsychiatric disorders. [11C](R)-PK11195 binding has been quantified using reference region approaches, with the reference defined anatomically or using unsupervised or supervised clustering algorith...

Phosphodiesterase 10A (PDE10A) inhibitors show therapeutic effects for diseases with striatal pathology. PET radiotracers have been developed to quantify in vivo PDE10A levels and target engagement for therapeutic interventions. The aim of this study was to compare two potent and selective PDE10A radiotracers, [11C]TZ1964B and [18F]MNI659 in the nonhuman primate (NHP) brain. Double scans in the...

BACKGROUND Tumor to normal tissue ratio (T/N ratio) on 11C-methionine (11C-MET) positron emission tomography/computed tomography (PET/CT) is affected by variable factors. We investigated whether T/N ratio cutoff values corrected according to metabolic tumor volume (MTV) could improve the diagnostic performance of 11C-MET PET/CT for diagnosis of recurrence in patients with metastatic brain tumor...

Despite the fact that the teratogenic effects of phenytoin have been suggested in several case reports, the evidence for a possible oncogenic potential of phenytoin has not been widely recognized. Recently, neuroblastoma as well as other neuroectodermal and non-ectodermal tumors has been seen in several children exposed to phenytoin prenatally. Previous cases have been almost uniformly associat...

BACKGROUND The previously validated NK1-receptor ligand [O-methyl-11C]GR205171 binds with a high affinity to the NK1-receptor and displays a slow dissociation from the receptor. Hence, it cannot be used in vivo for detecting concentration changes in substance P, the endogenous ligand for the NK1-receptor. A radioligand used for monitoring these changes has to enable displacement by the endogeno...

Ambulant patients with recently diagnosed generalised or psychomotor seizure disorders or both were randomly assigned to two dosage regimens of phenytoin. Drug compliance was evaluated with subsequent blood phenytoin levels four to eight weeks after initial enrollment into the study. Although the two groups had similar mg-kg daily dosages of phenytoin, the mean blood levels were statistically d...

Though rare, long term use of phenytoin has been associated with various lymphatic system disorders like pseudolymphoma, Hodgkin lymphoma and non Hodgkin lymphoma. Histopathological changes in phenytoin induced lymphadenopathy may be heterogenous and non specific as well. Phenytoin induced pseudo lymphoma syndrome may show histopathological findings similar to mycosis fungoides and may take a p...

Serum phenytoin concentrations were monitored prospectively in 26 patients with previously untreated partial epilepsy, during monotherapy with phenytoin. Only six remained entirely seizure-free, although only four experienced further tonic-clonic seizures. There was no correlation between serum phenytoin concentrations and freedom from partial seizures in those patients in whom such seizures re...

The present study was performed to determine whether positron emission tomography (PET) performed after i.v. 11C-palmitate permits detection and characterization of nontransmural myocardial infarction. PET was performed after the i.v. injection of 11C-palmitate in 10 normal subjects, 24 patients with initial nontransmural myocardial infarction (defined electrocardiographically), and 22 patients...

The usefulness of [1-11C]acetate as a tracer of overall myocardial oxidative metabolism for use with positron emission tomography has been investigated in 12 closed-chest dogs. Myocardial 11C activity clearance kinetics after intravenous administration of [1-11C]acetate in dogs have been determined noninvasively by positron emission tomography. Biexponential fitting of regional myocardial 11C t...