Two major carotenoids of the stick insect were reinvestigated and shown to be /?,/?-caroten-2-ol and /?,/?-carotene-2,2'-diol and not isocryptoxanthin (/?,/?-caroten-4-ol) and isozeaxanthin (/?,/?-carotene-4,4'-diol). Both pigments are esterified with fatty acids. The identification is based on cochromatography with authentic 2-, 3and 4-isomers of the monoand dihydroxy pigment, mass spectra, an...

Concentrations of beta-carotene were determined in maternal and fetal blood. The samples were collected from 33 mothers, their 33 newborns and 50 pregnant and 29 non-pregnant women. Beta-carotene concentrations of the non-pregnant, pregnant, newborn infant and their mothers were 140.31, 171.54, 63.57 and 175.74 micrograms/dl, respectively. There was a significant correlation (P < 0.001) between...

The IARC convened a Working Group of experts in December 1997 to evaluate the cancer-preventive potential of carotenoids and to compile the second volume of the IARC Handbooks of Cancer Prevention. In observational epidemiological studies, beta-carotene is associated with reduced risks for cancer at many but not all sites. It is unclear, however, to what extent beta-carotene itself is responsib...

1. The presence of astaxanthin in the shell of Ophidiaster ophidianus is confirmed, and that of #-carotene and cryptoxanthin demonstrated. neop-Carotene B and y-carotene are also probably present. 2. Three new pigments are reported: two are probably keto-carotenoids. 3. The quantitative distribution of carotenoids in the shell of 0. ophidianus is recorded. 4. A possible biosynthetic route from ...

The Dalkon Shield was an intrauterine contraceptive device (IUD) that women used in the early 1970s and 1980s. Produced by the A.H. Robins Company in the US, the Dalkon Shield was a contraceptive device placed directly into a woman?s uterus [3] that was supposed to prevent pregnancy [4]. In the 1980s, researchers discovered that the Dalkon Shield caused an array of severe injuries, including pe...

Shield tunneling construction of metro infrastructure will continuously disturb the soils. The ground surface will be subjected to uplift or subsidence due to the deep excavation and the extrusion and consolidation of the soils. Implementation of the simultaneous monitoring with the shield tunnel construction will provide an effective reference in controlling the shield driving, while how to de...

When the sub-core complex of photosystem II, D1/D2, is irradiated at 436 or 415 nm (absorption by chlorophyll and pheophytin and ß-carotene) or 540 nm (absorption primarily by pheophytin), the low temperature fluorescence spectrum has two maxima, at 685 and 674 nm. This shows the existence of at least two different fluorescent forms of chlorophyll (chlorophyll a and perhaps pheophytin a). When ...

Induction of gap junctional communication (GJC) and antioxidant activities of carotenoids have been considered as biochemical mechanisms underlying the cancer-preventive properties of these compounds. beta-Carotene and other carotenoids, including those lacking provitamin A activity, proved to be active in both these parameters. The beta-carotene analogs retrodehydro-beta-carotene, echinenone, ...

We measured carotene in the livers of two patients receiving beta-carotene therapy for photosensitivity. In both patients, the amount of carotene was within reported ranges for patients on normal diets; no abnormal amounts of beta-carotene had accumulated in the livers after oral administration of large amounts of beta-carotene. Light-microscopic examination of the liver (specimen obtained at c...

*Corresponding Address: LC Nnaji [email protected] In view of the fundamental role of antioxidants such as beta carotene in human nutrition, this study was designed to determine the concentrations of this antioxidant in chicken egg yolks of the preponderant poultry breeds in Nigeria. Among the strains studied include Harco, White Leghorn, and Local chickens. Again, due to instability...