Iodine quantification and detectability thresholds among major dual-energy CT platforms.

Objectives: To estimate the minimum detectable iodine concentration on multiple dual-energy CT (DECT) platforms.

Methods And Materials: A phantom containing iodine concentrations ranging from 0 to 10 mg ml was scanned with five dual-energy platforms (two rapid kilo volt switching (r-kVs), one dual source (DS), one sequential acquisition and one split-filter). Serial dilutions of 300 mg ml iodinated contrast material were used to generate concentrations below 2 mg ml.

Regulation of the pH sensitivity of human P2X receptors by N-linked glycosylation.

The human (h) P2X(3) receptor and its mutants deficient in one out of four N-glycosylation sites were expressed in HEK293 cells. Concentration-response curves were generated by whole-cell recordings of alpha,beta-methylene ATP (alpha,beta-meATP)-induced currents. A gradual change of external pH from the alkaline 8.

Conserved lysin and arginin residues in the extracellular loop of P2X(3) receptors are involved in agonist binding.

Wild-type human (h) P2X(3) receptors expressed in HEK293 cells responded to the prototypic agonist alpha,beta-methylene ATP (alpha,beta-meATP) with rapidly desensitizing inward currents and an increase in the intracellular Ca(2+) concentration. In contrast to electrophysiological recordings, Ca(2+) microfluorimetry showed a lower maximum of the concentration-response curve of alpha,beta-meATP in the transiently than in the permanently transfected HEK293 cells. However, the concentrations causing 50% of the maximum possible effect (EC(50) values) were identical, when measured with either method.

The h-P2X3 glycoprotein receptor as an example of integrating bioinformatics and structural research.

This review deals with the molecular modelling of a subtype of the membrane-embedded purinoreceptor P2X family, which belongs to the large class of membrane-embedded glycoproteins. The P2X family has two transmembrane domains and a core of five extracellularly occurring disulfide bonds. At present, seven different P2X receptor subtypes (P2X1 - X7) have been cloned.