Digital Medical Device Companion (MyIUS) for New Users of Intrauterine Systems: App Development Study.

Background: Women choosing a levonorgestrel-releasing intrauterine system may experience changes in their menstrual bleeding pattern during the first months following placement.

Objective: Although health care professionals (HCPs) can provide counseling, no method of providing individualized information on the expected bleeding pattern or continued support is currently available for women experiencing postplacement bleeding changes. We aim to develop a mobile phone-based medical app (MyIUS) to meet this need and provide a digital companion to women after the placement of the intrauterine system.

Efficacy of the iodine-free computed tomography liver contrast agent, Dy-EOB-DTPA, in comparison with a conventional iodinated agent in normal and in tumor-bearing rabbits.

Rationale And Objectives: To investigate the efficacy of the new liver-specific x-ray contrast agent, Dy-EOB-DTPA, in rabbits with VX2 liver tumors by spiral computed tomography (CT) in comparison to iopromide.

Materials And Methods: The time course of liver enhancement was determined in five groups of two normal anesthetized rabbits, which received intravenous injections of Dy-EOB-DTPA before anesthesia at a dose of 0.5 mmol/kg.

Gd-EOB-DTPA and Yb-EOB-DTPA: two prototypic contrast media for CT detection of liver lesions in dogs.

Purpose: To characterize computed tomographic (CT) attenuation of iodine, gadolinium, and ytterbium in vitro and to study CT liver enhancement after administration of two prototypic hepatocyte-directed contrast media in dogs.

Materials And Methods: Samples with increasing concentrations of iodine, gadolinium, and ytterbium were measured for CT attenuation in a water phantom at tube voltages of 80, 120, and 137 kV. Three groups of five adult beagle dogs each received a 0.

Pharmacokinetics of the liver-specific contrast agent Gd-EOB-DTPA in relation to contrast-enhanced liver imaging in humans.

This study was performed to evaluate the effect of dose on the pharmacokinetics and efficacy of the gadolinium-based contrast medium gadoxetic acid, disodium, [gadolinium (4S)-4-(4-ethoxybenzyl)-3,6,9-tris(carboxylatomethyl)-3,6, 9-triazaundecandioic acid-disodium salt] (Gd-EOB-DTPA) as a liver-specific hepatobiliary contrast medium for computed tomography. Pharmacokinetics in serum and the pattern of elimination were investigated in 18 healthy volunteers up to 6 days after a 10-minute infusion of 0.2 mmol, 0.

A prototype liver-specific contrast medium for CT: preclinical evaluation of gadoxetic acid disodium, or Gd-EOB-DTPA.

Purpose: The suitability of the hepatobiliary contrast medium gadoxetic acid disodium, or Gd-EOB-DTPA, for liver enhancement at computed tomography (CT) was studied.

Materials And Methods: CT attenuation levels at 120 kV were measured in samples of increasing concentrations of gadolinium (gadoxetic acid disodium) or iodine (iopromide) in aqueous solutions in vitro. In dogs, CT attenuation in the liver was measured up to 90 minutes after a single intravenous injection of 0.

[Electron-beam tomographic imaging of the coronary arteries: an experimental comparison between monomeric and dimeric x-ray contrast media].

Purpose: Comparison of a monomeric and a dimeric radiographic contrast medium in the visualisation of the coronary arteries via electron beam tomography (EBT).

Material And Methods: In a total of 6 Göttingen minipigs the heart was examined by EBT (40 sections, ECG-triggering, 1.5 mm section thickness, 100 ms acquisition time) after injection of both iopamidol (monomer, 370 mg l/ml) and iotrolan (dimer, 320 mg l/ml) at a dose of 740 mg l/kg.

Ytterbium- and dysprosium-EOB-DTPA. A new prototype of liver-specific contrast agents for computed tomography.

Rationale And Objectives: A series of studies was conducted to determine whether metal complexes of the EOB-DTPA type are useful as contrast agents for computed tomography (CT).

Methods: Metal complexes using EOB-DTPA as ligand were synthesized with lanthanide metal ions (lanthanum [La], cerium [Ce], praseodyme [Pr], gadolinium [Gd], dysprosium [Dy], ytterbium [Yb], and lutetium [Lu]) and with nonlanthanides (lead [Pb] and bismuth [Bi]). Complex stability was assessed by measuring binding to bone meal.

Cardiac and hemodynamic tolerability of iodinated contrast media in the anesthetized rat.

Rationale And Objectives: The study was designed to compare the hemodynamic effects of 11 iodinated contrast media (CM), including ionic (diatrizoate, ioxaglate), nonionic monomeric (iohexol, iopromide, iopamidol, iopentol, ioversol, iomeprol, ZK 139129), and nonionic dimeric (iotrolan, iodixanol) compounds.

Methods: Following left ventricular bolus injection of 1.2 g I/kg body weight in anesthetized rats, cardiohemodynamic parameters were measured.

Liver contrast enhancement in primates using iopromide liposomes.

Rationale And Objectives: We studied the feasibility of using iodinated liposomes as computed tomography (CT) liver contrast agents in nonhuman primates.

Methods: Iopromide-containing liposomes were investigated as reticuloendothelial (RES) contrast agents for CT scanning of the liver in normal adult baboons. For intravenous (i.

Pre-clinical evaluation of gadobutrol: a new, neutral, extracellular contrast agent for magnetic resonance imaging.

The Gd(3+)-complex of 10-(2,3-dihydroxy-1-hydroxymethylpropyl)-1,4,7,10-tetraazacyclo dodecane-1,4,7-triacetic acid(gadobutrol) is a new, neutral Gd-chelate for use as an extracellular contrast agent in magnetic resonance imaging (MRI). The blood level in dogs after intravenous (i.v.

Evaluation of gadobutrol in a rabbit model as a new lanthanide contrast agent for computed tomography.

Rationale And Objectives: The efficacy of the neutral lanthanide contrast agent gadobutrol was compared to that of the iodinated contrast agent iopromide in rabbits.

Methods: The computed tomography (CT) attenuation of increasing concentrations of gadolinium (Gd) (gadobutrol) and iodine (I) (iopromide) was measured in Hounsfield units (HU) in aqueous solution at 80, 120, and 137 kV. The peak enhancement (net increase in CT attenuation compared with baseline) and the time-enhancement product in the aorta and in the renal parenchyma of the outer and inner cortex were measured in rabbits over a 5-minute period after the animals were given single intravenous injections of 0.

Pharmacokinetics of iopromide liposomes in rabbits.

Purpose: The dose-proportionality of pharmacokinetics of an iodinated contrast medium, iopromide, encapsulated into liposomes was investigated.

Methods: Following single intravenous administration of 150 mg iodine/kg (potential diagnostic dose) and a five-fold higher dose in rabbits the pattern of elimination was studied until 7 d and the blood concentrations were monitored up to 72 h after administration. The iodine concentration in the liver was calculated on the basis of the blood concentration and related to the concentration measured in the rabbit liver.

Pharmacokinetics, dose proportionality, and tolerability of gadobutrol after single intravenous injection in healthy volunteers.

Rationale And Objectives: Gadobutrol is a new gadolinium-based hydrophilic and neutral macrocyclic contrast medium for magnetic resonance imaging. In this article, the authors report on the first application of gadobutrol in humans, up to a dose of 0.5 mmol/kg.

Dose proportionality of iopromide pharmacokinetics and tolerability after i.v. injection in healthy volunteers.

Twelve healthy male volunteers participated in a single-blind, randomised, placebo-controlled cross-over study of i.v. iopromide in doses of 15 g iodine or 80 g iodine infused over a period of 15 min.

Characterization of iopromide liposomes.

Rationale And Objectives: Iopromide-carrying liposomes were prepared and were characterized pharmaceutically and biologically.

Methods: The liposomes were prepared by the ethanol evaporation method and were characterized by quasi-elastic light scattering (size) and equilibrium dialysis (encapsulation efficiency and stability). Acute and subchronic toxicity was tested in mice and/or rats and cardiovascular tolerance in rabbits.

Pharmaceutical properties, biodistribution, and imaging characteristics of manganese-mesoporphyrin. A potential hepatobiliary contrast agent for magnetic resonance imaging.

Objectives: Manganese (III) mesoporphyrin (Mn-mesoporphyrin) was investigated for its pharmaceutical properties and magnetic resonance imaging characteristics as a potential hepatobiliary contrast agent.

Methods: Solubility, partition coefficient, plasma binding, proton relaxation enhancement, biodistribution, biliary excretion, liver extraction ratio, and liver enhancement were measured in various in-vitro and in-vivo systems.

Results: Mn-mesoporphyrin was soluble and stable at moderate alkaline pH in phosphate buffer.

Nonlinear pharmacokinetic modeling of a gadolinium chelate used as a liver-specific contrast agent for magnetic resonance imaging.

The introduction of the lipophilic moiety, ethoxybenzyl, into the gadolinium chelate gadopentate dimeglumine (Gd-DTPA, Magnevist, CAS 86050-77-3) yielded gadolinium-(4S)4-(4-ethoxybenzyl)-3,6,9-tris(carboxylatomethyl+ ++)-3,6,9- triazaundecandioic acid, disodium salt (Gd-EOB-DTPA) a compound with a potential as a magnetic resonance contrast agent for liver mass screening. After intravenous administration in rats (0.05 and 0.

Biliary excretion and pharmacokinetics of a gadolinium chelate used as a liver-specific contrast agent for magnetic resonance imaging in the rat.

The introduction of a lipophilic moiety into the gadolinium chelate Gd-DTPA (dimeglumine gadopentetate, Magnevist) yielded Gd-EOB-DTPA (short form), which has potential as a magnetic resonance contrast agent for liver mass screening. The pharmacokinetics of Gd-EOB-DTPA in rats is nonlinear because after correction for the 10-fold difference in dose, the area under the curve of plasma concentration versus time from time zero to infinity after single intravenous application of two different doses were not superimposable, and the amounts excreted renally and extrarenally differed significantly. However, for both dose groups tested, the values of renal clearance (9.

Liver contrast media for magnetic resonance imaging. Interrelations between pharmacokinetics and imaging.

In the development of liver CM for MRI, three mainstream approaches have been undertaken: targeting of water-soluble MRI-CM to the hepatocytes, targeting of particles to the Kupffer cells of the liver, and application of macromolecular CM to tumorous tissue. As with the biliary iodinated CM, the physiological function of the liver has been used to target paramagnetic chelates (T1 agents) to the hepatocytes. Gd-EOB-DTPA and Gd-BOPTA are taken up mainly by hepatocytes and excreted into the bile by organic anion transporter (bilirubin transporter), whereas MnDPDP also uses the ability of hepatocytes to excrete metal ions, such as manganese.

Pharmacokinetics in rats, dogs and monkeys of a gadolinium chelate used as a liver-specific contrast agent for magnetic resonance imaging.

The introduction of the lipophilic moiety, ethoxybenzyl, into the gadolinium chelate dimeglumine gadopentetate (Gd-DTPA, Magnevist, CAS 86050-77-3) yielded (4S) 4-(4-ethoxybenzyl)-3,6,9-tris (carboxylatomethyl)-3,6,9-triazaundecandioic acid, gadolinium complex, disodium salt (Gd-EOB-DTPA), a compound with a potential as a magnetic resonance contrast agent for liver mass screening. Both in the rat and in the dog the pharmacokinetics of Gd-EOB-DTPA were nonlinear in the dose range of 0.05-0.

[Pharmacokinetics of gadolinium-DTPA in chronic renal insufficiency requiring dialysis].

MRT with gadolinium-DTPA (0.1 mmol/kg body weight) was performed in 10 patients with renal insufficiency requiring dialysis and the clearance of gadolinium-DTPA was studied. After 3 dialysis on 3 successive days more than 97% of the initial concentration of gadolinium-DTPA had been eliminated.

Preclinical evaluation of Gd-EOB-DTPA as a contrast agent in MR imaging of the hepatobiliary system.

Gadolinium diethylenetriaminepentaacetic acid (DTPA) covalently linked to the lipophilic ethoxybenzyl moiety (Gd-EOB-DTPA) was designed for use as a contrast agent in hepatobiliary magnetic resonance imaging. With T1 relaxivity values of 8.7 L/mmol.