Human monocyte-derived macrophages ingest diamide-treated red blood cells (RBC), anti-D immunoglobulin (Ig)G-opsonized RBC, or Plasmodium falciparum ring-stage parasitized RBC (RPRBC), degrade ingested hemoglobin rapidly, and can repeat the phagocytic cycle. Monocytes fed with trophozoite-parasitized RBC (TPRBC), which contain malarial pigment, or fed with isolated pigment are virtually unable ...

The presence of carotenoids in animal tissue reflects their sources along the food chain. Astaxanthin, the main carotenoid used for salmonid pigmentation, is usually included in the feed as a synthetic product. However, other dietary sources of astaxanthin such as shrimp or krill wastes, algae meal or yeasts are also available on the market. Astaxanthin possesses two identical asymmetric atoms ...

We performed a histopathologic and immunohistochemical study of eyes obtained at autopsy of an 84-year-old man from a family with X-linked cone degeneration in which affected members have a 6.5-kilobase deletion in the red cone pigment gene. At his most recent ocular examination, at age 71 years, this patient had had a visual acuity of 20/200 OU, fundus changes suggestive of macular degeneratio...

Cone photoreceptors of the vertebrate retina terminate their response to light much faster than rod photoreceptors. However, the molecular mechanisms underlying this rapid response termination in cones are poorly understood. The experiments presented here tested two related hypotheses: first, that the rapid decay rate of metarhodopsin (Meta) II in red-sensitive cones depends on interactions bet...

A novel purple-red pigment from the plant genus of Allium (onions, leeks), subgenus Melanocrommyum (drumstick onions), is described. Because this pigment, which reminds blood, some species are used in Southwest and Central Asia as herbal medications, spices or vegetables. proposal for formation structure provided, first example a tetrathiaporphyrin nature. The described substance shows low stab...

The production of color variants of Serratia marcescens by means of ultraviolet light irradiation has been reported by Labrum and Bunting (1953). These variants exhibited several shades of pink, orange, or white pigmentation, and differed markedly from the natural or wild-type red color. Rizki (1954a) demonstrated that several of these pink, orange, and white variants were capable of inducing r...

The action spectrum for the light-activated destruction of phytochrome in etiolated Avena seedlings has been determined. There are 2 broad maxima, one between 380 and 440 mmu, the other between 600 and 700 mmu. peaking at about 660 mmu. On an incident energy basis, the red region of the spectrum is more efficient than the blue by about one order of magnitude in activating phytochrome disappeara...

Carotenoids from some of the coloured yeasts like Rhodotorula, Phaffia rhodozyma have attracted commercial interest as a natural pigment for foods. Red yeast isolated from the contaminated PDA plate yeast has been found to produce carotenoids. This red was characterized and designated as Rhodotorula glutinis DFR-PDY. The isolated crude pigment from the red yeast Rhodotorula glutinis DFR-PDY was...

The coloration of the common butterflies Aglais urticae (small tortoiseshell), Aglais io (peacock) and Vanessa atalanta (red admiral), belonging to the butterfly subfamily Nymphalinae, is due to the species-specific patterning of differently coloured scales on their wings. We investigated the scales' structural and pigmentary properties by applying scanning electron microscopy, (micro)spectroph...