Pharmacology of RG W-2938: a cardiotonic agent with vasodilator activity.

The cardiovascular effects of RG W-2938, 6-[6-(3,4-dihydro-3-methyl-2(1H)-2-oxoquinazolinyl)]-4,5-dihydro-3 (2H-pyridazinone, a new nonglycoside, noncatecholamine cardiotonic/vasodilator agent were examined in vivo in anesthetized and conscious dogs and in vitro in isolated guinea pig hearts; in the latter, RG W-2938 5 nmol-5 mumol increased contractility in a dose-related fashion. RG W-2938 30-300 micrograms/kg administered intravenously (i.v.

Pulsed laser-induced damage of metals at 492 nm.

A triaxial flashlamp-pumped dye laser has been used to perform laser damage testing of metal surfaces in the blue-green spectral region. Using LD490 laser dye, the laser produces 0.18-J, 0.

Measurement of optical coupling coefficients based on thermal expansion.

A fundamentally new method for measuring optical coupling coefficients is described. A sample of a particular shape is subjected to a fixed tensile load and heated with pulsed optical radiation. The resulting peak tensile relaxation is proportional to the total absorbed energy; evolution of the coupling coefficient may thus be observed.

Hepatic clearance mechanism of Tc-99m-HIDA and its effect on quantitation of hepatobiliary function: Concise communication.

Parameters affecting the hepatobiliary clearance of Tc-99m N(2,6-dimethylphenyl carbamoylmethyl) iminodiacetic acid (Tc-HIDA) were evaluated in dogs. Competitive clearance studies, were performed with Tc-HIDA after infusion to plasma saturation levels of an anion, sodium sulfobromophthalein (BSP), and a cation, oxyphenonium. The results demonstrated that Tc-HIDA is transported through hepatocytes by a carrier-mediated organic-anion pathway.

Development of new radiopharmaceuticals based on N-substitution of iminodiacetic acid.

A new approach to radiopharmaceutical design is demonstrated, in which small chelating groups capable of binding gamma-emitting radiometals are attached to biologically active molecules, thus producing radiopharmaceuticals based on bifunctional drug and biochemical analogs. The chelating group iminodiacetic acid has been evaluated for this role by examining two N-substituted iminodiacetic acids: methyliminodiacetic acid (MIDA) and N-(2,6-dimethylphenylcarbamoylmethyl)iminodiacetic acid (HIDA). Radiochemical and biologic studies showed that both agents were obtained in high radiochemical purity, were stable in vitro and in vivo, and possessed biologic distributions governed almost exclusively by the N-substituted group.