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In this study, a comparative analysis of metal-related neuronal vulnerability was performed in two brainstem nuclei, the locus coeruleus (LC) and substantia nigra (SN), known targets of the etiological noxae in Parkinson's disease and related disorders. LC and SN pars compacta neurons both degenerate in Parkinson's disease and other Parkinsonisms; however,(More)
Melanin, the pigment in hair, skin, eyes, and feathers, protects external tissue from damage by UV light. In contrast, neuromelanin (NM) is found in deep brain regions, specifically in loci that degenerate in Parkinson's disease. Although this distribution suggests a role for NM in Parkinson's disease neurodegeneration, the biosynthesis and function of NM(More)
Neuronal pigments of melanic type were identified in the putamen, cortex, cerebellum, and other major regions of human brain. These pigments consist of granules 30 nm in size, contained in organelles together with lipid droplets, and they accumulate in aging, reaching concentrations as high as 1.5-2.6 microg/mg tissue in major brain regions. These pigments,(More)
Rapid photoinduced electron transfer is demonstrated over a distance of greater than 40 angstroms between metallointercalators that are tethered to the 5' termini of a 15-base pair DNA duplex. An oligomeric assembly was synthesized in which the donor is Ru(phen)2dppz2+ (phen, phenanthroline, and dppz, dipyridophenazine) and the acceptor is Rh(phi)2phen3+(More)
Spectroscopic parameters for two novel ruthenium complexes on binding to nucleic acids of varying sequences and conformations have been determined. These complexes, Ru(bpy)2dppz2+ and Ru(phen)2dppz2+ (bpy = 2,2'-bipyridine; phen = 1,10-phenanthroline; dppz = dipyrido[3,2:a-2',3':c]-phenazine) serve as "molecular light switches" for DNA, displaying no(More)
DNA sequencing by synthesis (SBS) on a solid surface during polymerase reaction can decipher many sequences in parallel. We report here a DNA sequencing method that is a hybrid between the Sanger dideoxynucleotide terminating reaction and SBS. In this approach, four nucleotides, modified as reversible terminators by capping the 3'-OH with a small reversible(More)
A2E is one of the bis-retinoid pyridinium compounds that accumulate as lipofuscin pigments in retinal pigment epithelial (RPE) cells in association with aging and in some inherited forms of retinal degeneration. Here we observed that 430nm irradiation of A2E in the presence of the spin trap DMPO, led to the appearance of a superoxide dismutase-inhibitable(More)
Breakdown of chlorophyll is a major contributor to the diagnostic color changes in fall leaves, and in ripening apples and pears, where it commonly provides colorless, nonfluorescent tetrapyrroles. In contrast, in ripening bananas (Musa acuminata) chlorophylls fade to give unique fluorescent catabolites (FCCs), causing yellow bananas to glow blue, when(More)
Here we report on a phenanthridine derivative which has a covalently linked fluorescein molecule in order to increase the light absorption and hence fluorescence signal intensity when bound to duplex RNA. Steady-state fluorescence shows that the energy transfer efficiency from the fluorescein to the phenanthridine fluorophore is approximately 77%, which(More)