Absorption and storage of [14C]beta-carotene in control and beta-carotene-fed (BC-fed) rats were determined. Pre-feeding with beta-carotene for 2 weeks caused a 1.9-fold stimulation of its own absorption as well as its conversion to retinyl esters, whereas the absorption of [3H]retinyl acetate was unaffected. The liver and the lungs accounted for 60% and 30%, respectively, of the total recovere...

Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) functions both in regulation of insulin secretion and neurotransmitter release through common downstream mediators. Therefore, we hypothesized that pancreatic ß-cells acquire and store the information contained in calcium pulses as a form of "metabolic memory", just as neurons store cognitive information. To test this hypothesis, we develop...

Aim. To explore whether first-trimester levels of pregnancy-associated plasma protein-A (PAPPA) and serum free ß-human chorionic gonadotrophin (free ß-hCG) vary with maternal blood group and rhesus status and to determine their implications for Down syndrome. Methods. Blood samples were collected from all 539 singleton pregnancies undergoing first-trimester screening. Values of maternal serum P...

Photosystem I preparations were obtained from wild type tobacco Nicotiana tabacum var. John William’s Broadleaf (JWB) and from the two chlorophyll-deficient mutants N tabacum Su/su and N. tabacum Su/su var. Aurea. The preparations were characterized with respect to the chlorophyll a/b ratio, their photosynthetic activity and their absorption spectroscopic properties. Peptides from these prepara...

Does beta-carotene increase, rather than decrease, human lung cancer rates? A large body of observational epidemiologic study has demonstrated that individuals who eat more fruits and vegetables rich in carotenoids and/or who have higher levels of serum betacarotene have a lower risk of cancer, particularly lung cancer. This inverse relationship has been particularly strong in lung cancer patie...

A new HPLC/DAD (Diode Array Detector) method is proposed for the identification of some carotene isomers. The operating conditions adopted permit the resolution of α-carotene, all-trans-β-carotene, 9-cis-β-carotene, 13-cis-β-carotene and 15-cis-β-carotene. Moreover, the chromatographic conditions reported are simplified in respect of those reported up to now. The method is applied to the determ...

Patients undergoing carotid endarterectomy were pretreated with low-dose, oral beta carotene to determine whether the carotenoid content of plaque could be increased in vivo. Beta carotene-treated patients had a 50-fold increase in their plaque beta carotene level from 0.066 to 3.3 micrograms beta carotene/g plaque. Microscopy and microspectrophotometry demonstrated that plaque from beta carote...

BACKGROUND Intervention studies have shown an increased mortality in patients who received beta-carotene. However, the mechanisms involved in this phenomenon are still unknown. OBJECTIVE Evaluate the influence of beta-carotene on oxidative stress and the expression of connexin 43 in rat hearts. METHODS Wistar rats, weighing approximately 100 g, were allocated in two groups: CONTROL GROUP (n...

ß-Cyclodextrin (ß-CD) solubilizes stickies from deinked pulp, commercial adhesive formulations, or magazine inserts, which demonstrates its potential as a washing aid. A new test to simulate coater scratches is described; it involves scraping the test paper sample across the surface of a thin layer chromatography plate and measuring the degree of scratching on the plate. Scratching was signific...

Objective: Several studies have shown that the adult pancreas possesses a limited potential for ß– cell regeneration upon tissue injury. One of the difficulties in studying ß-cell regeneration has been the lack of a robust, synchronized animal model system that would allow controlled regulation of ß−cell loss and subsequent proliferation in adult pancreas. Research Design and Methods: Here we p...