BACKGROUND Previous studies have provided evidence for the importance of platelet-derived nitric oxide (NO) for the regulation of hemostasis. Tetrahydrobiopterin (BH4) is an essential cofactor and regulator of NO synthase activity in the vasculature; however, it is as yet unknown whether platelets dispose over a functional BH4 synthesis. METHODS AND RESULTS We quantified mRNA expression of ge...

materials and methods total protein was determined by lowery method. bovine lens alr2 was partially purified by gel filtration chromatography on sephadextm g25. bovine cortex kidney alr1 was partially purified by diethylaminoethyl (deae) precipitation. the hydroalcoholic extract was obtained from frozen propolis. the enzyme activity and sorbitol accumulation in erythrocytes were determined spec...

We have isolated a dominant mutation, pugilistDominant (pugD), that causes variegated reductions in pteridine and ommochrome pigmentation of the Drosophila eye. The effect of pugD on pteridine pigmentation is most dramatic: the only remaining pigment consists of a thin ring of pigment around the periphery of the eye with a few scattered spots in the center. The pugD mutation disrupts a gene tha...

In cerebrospinal fluid of patients with cerebral infections, elevated concentrations of the pteridine compounds neopterin and 7,8-dihydroneopterin were detected. Here, the potential of pteridines to induce apoptosis of the rat pheochromocytoma cells (PC12) was investigated. In contrast to aromatic pteridines like neopterin, the reduced forms 7,8-dihydroneopterin, 5,6,7,8-tetrahydrobiopterin and...

Background. The age of an insect strongly influences many aspects of behavior and reproduction. The interaction of age and behavior is epitomized in the temporal polyethism of honey bees in which young adult bees perform nurse and maintenance duties within the colony, while older bees forage for nectar and pollen. Task transition is dynamic and driven by colony needs. However, an abundance of p...

The chloroform-soluble pigments of various pseudomonads have been found to be phenazine derivatives (Clemo & Daglish, 1950; Hillemann, 1938; Kogl & Postowsky, 1930; Kluyver, 1956; Haynes et al. 1956), whereas the constitutions of water-soluble fluorescent pigments of various pseudomonads are not well known. This has been mainly due to the failure of previous attempts to obtain the pigments in a...