Uptake, efflux, and mass transfer coefficient of fluorescent PAMAM dendrimers into pancreatic cancer cells.

Targeted delivery of imaging agents to cells can be optimized with the understanding of uptake and efflux rates. Cellular uptake of macromolecules is studied frequently with fluorescent probes. We hypothesized that the internalization and efflux of fluorescently labeled macromolecules into and out of mammalian cells could be quantified by confocal microscopy to determine the rate of uptake and efflux, from which the mass transfer coefficient is calculated.

2D rotational angiography for fast and standardized evaluation of peripheral and visceral artery stenoses.

Purpose: To investigate the value of rotational digital subtraction angiography (rDSA) for evaluation of peripheral and visceral artery stenoses compared to conventional digital subtraction angiography (cDSA).

Methods: A phantom study was performed comparing the radiation dose of cDSA with two projections and rDSA by means of the 2D Dynavision technique (Siemens Medical Solutions, Forchheim, Germany). Subsequently, 33 consecutive patients (18 women, 15 men; mean±SD age 67±15 years) were examined by both techniques.

Physiologically based pharmacokinetics of molecular imaging nanoparticles for mRNA detection determined in tumor-bearing mice.

Disease detection and management might benefit from external imaging of disease gene mRNAs. Previously we designed molecular imaging nanoparticles (MINs) based on peptide nucleic acids complementary to cancer gene mRNAs. The MINs included contrast agents and analogs of insulin-like growth factor 1 (IGF-1).

Design of (Gd-DO3A)n-polydiamidopropanoyl-peptide nucleic acid-D(Cys-Ser-Lys-Cys) magnetic resonance contrast agents.

We hypothesized that chelating Gd(III) to 1,4,7-tris(carboxymethylaza)cyclododecane-10-azaacetylamide (DO3A) on peptide nucleic acid (PNA) hybridization probes would provide a magnetic resonance genetic imaging agent capable of hybridization to a specific mRNA. Because of the low sensitivity of Gd(III) as an magnetic resonance imaging (MRI) contrast agent, a single Gd-DO3A complex per PNA hybridization agent could not provide enough contrast for detection of cancer gene mRNAs, even at thousands of mRNA copies per cell. To increase the Gd(III) shift intensity of MRI genetic imaging agents, we extended a novel DO3An-polydiamidopropanoyl (PDAPm) dendrimer, up to n = 16, from the N-terminus of KRAS PNA hybridization agents by solid phase synthesis.

Cardiac troponin T for prediction of short- and long-term morbidity and mortality after elective open heart surgery.

Background: Increased cardiac troponins in blood are observed after virtually every open heart surgery, indicating perioperative myocardial cell injury. We sought to determine the optimum time point for blood sampling and the respective cutoff value of cardiac troponin T (cTnT) for risk assessment in patients undergoing cardiac surgery.

Methods: In a series of 204 patients undergoing scheduled open heart surgery, mainly for coronary artery bypass grafting (n = 132) or valve repair (n = 27), cTnT concentrations were measured before and 4 and 8 h after cross-clamping and then daily for 7 days.