BACKGROUND & OBJECTIVES Simultaneous administration of phenytoin and isoniazid (INH) in tuberculous meningitis (TBM) or tuberculoma patients with seizures results in higher plasma phenytoin level and thus phenytoin intoxication. N-acetyltransferase 2 (NAT2) enzyme catalyses two acetylation reactions in INH metabolism and NAT2 gene polymorphism leads to slow and rapid acetylators. The present st...

During cholestasis, accumulation of conjugated bile acids may occur in the liver and lead to hepatocellular damage. Inspired by our recent development of N-11C-methyl-glycocholic acid—that is, 11C-cholylsarcosine—a tracer for PET of the endogenous glycine conjugate of cholic acid, we report here a radiosynthesis of N-11C-methyltaurine–conjugated bile acids and biodistribution studies in pigs by...

Patients with large variations in phenytoin levels despite standard doses may prove to become difficult clinical problems. Our study of 34 head injury patients whose serum phenytoin levels were measured on day one and day five following intravenous loading and maintenance dose of phenytoin, showed 38.24% patients, to have therapeutic phenytoin levels on day one, while 20% were in toxic range. O...

OBJECTIVES Both reconstruction algorithms, filtered backprojection (FBP) and ordered subsets expectation maximization (OSEM), are widely used in clinical positron emission tomography (PET) studies. Image reconstruction for most neurotransmission PET scan data is performed by FBP, while image reconstruction for whole-body [18F]FDG scan data is usually performed by OSEM. Although several investig...

BACKGROUND Androgen deprivation (AD) is generally used as a first-line palliative treatment in prostate cancer (PCa) patients with rising prostate-specific antigen (PSA) after primary therapy. To acquire an accurate detection of tumour viability following AD with positron emission tomography (PET), an androgen-independent uptake of tracers would be advantageous. Several metabolic PET tracers ar...

Tumor uptake of L-[methyl-11C]methionine ([11C]Met) was assessed in six patients with brain tumors and three patients with lung cancer using positron emission tomography (PET). In arterial plasma samples taken at 5, 15, 30, and 60 min after injection, a fraction of [11C]Met was measured using high performance liquid chromatography in individual patients. Employing curve fitting, a history of [1...

Octanoate is taken up into the brain and is converted in astrocytes to glutamine through the TCA cycle after beta-oxidation. We speculate that [1-11C]octanoate may be used as a tracer for astroglial functions and/or fatty acid metabolism in the brain and may be useful for studying cerebral ischemia. In the present study we investigated brain distribution of [1-11C]octanoate and compared it with...

The aim of the present study was to determine the effect of "binge" pattern cocaine administration on dopamine D1 and D2 receptors in the rat brain. Male Sprague Dawley rats were injected three times at 1 hr intervals with saline or cocaine (15 mg/kg) each day for 2, 7, or 14 d. The in vivo binding of [11C]SCH23390 (dopamine D1 receptor antagonist) and [11C]N-methylspiperone (NMSP; dopamine D2 ...

The purpose of this investigation was to determine if administration of heparin causes displacement of an acidic drug from serum protein binding sites in vivo as has been suggested by several groups of investigators. Rats were injected and infused with phenytoin to produce steady-state serum concentrations of about 25 micrograms/ml. After 2 hr, some of the animals also received injections and i...

UNLABELLED The development of the radioligands for PET imaging of the cerebral cannabinoid receptor (CB1) is of great importance for studying its role in neuropsychiatric disorders, obesity, and drug dependence. None of the currently available radioligands for CB1 are suitable for quantitative PET, primarily because of their insufficient binding potential (BP) in brain or low penetration throug...