Macrocyclic chelators with paramagnetic cations are internalized into mammalian cells via a HIV-tat derived membrane translocation peptide.

A major obstacle to using paramagnetic MR contrast agents for in vivo cell tracking or molecular sensing is their generally low cellular uptake. In this study, we show that a paramagnetically labeled DOTA chelator derivatized with a 13-mer HIV-tat peptide is efficiently internalized into mammalian cells. Intracellular concentrations were attained that were readily detectable by MR imaging using both gadolinium and dysprosium chelates.

Myocardial high-energy phosphate metabolism in patients with stable chronic dilated cardiomyopathy under a dobutamine-induced prolonged mild workload.

Background: The myocardial phosphocreatine (PCr) to beta-adenosine triphosphate ratio measured by phosphorus 31 nuclear magnetic resonance spectroscopy, which is analogous to energy reserve, is one of the important clinical predictors in patients with dilated cardiomyopathy (DCM). However, it may vary with the cardiac workload.

Method: The myocardial PCr to beta-adenosine triphosphate ratio was measured before and during a 5 and 10 microgram/kg/min infusion of dobutamine in 7 patients with DCM and in 8 normal patients.

Elevation of plasma lipid peroxides in non-insulin dependent diabetics with multiple lacunar infarcts.

Our purpose was to determine whether lipid peroxides are elevated in the plasma of patients with non-insulin dependent diabetes with multiple lacunar infarcts as detected by magnetic resonance imaging (MRI), and to confirm whether peroxide levels correlate with glycemic controls and blood lipid levels. The level of lipid peroxide (measured as thiobarbituric acid reactive substances (TBARS)) was measured in 23 healthy controls and 28 diabetics showing normal MRI findings and 22 diabetics with multiple lacunar infarcts. These groups were age-matched.

Copper concentration in hyperintense hepatocellular carcinomas of Long-Evans cinnamon rats on T1-weighted images.

The Long-Evans Cinnamon (LEC) rat has abnormal intrahepatic copper accumulation and spontaneously develops hepatocellular carcinomas following hereditary hepatitis. The hepatocellular carcinomas are very similar to human well-differentiated hepatocellular carcinoma in histopathological features and on MR images. Copper is believed to be one of the causes of hyperintensity of hepatocellular carcinomas compared to surrounding non-cancerous tissues on T1-weighted MR image.