TY - JOUR A1 - Garcia, Ada Lizbeth A1 - Raila, Jens A1 - Koebnick, Corinna A1 - Eulenberger, Klaus A1 - Schweigert, Florian J. T1 - Great apes show highly selective plasma carotenoids and have physiologically high plasma retinyl esters compared to humans JF - American journal of physical anthropology N2 - Great apes are the closest living relatives of humans. Physiological similarities between great apes and humans provide clues to identify which biological features in humans are primitive or derived from great apes. Vitamin A (VA) and carotenoid metabolism have been only partially studied in great apes, and comparisons between great apes and humans are not available. We aimed to investigate VA and carotenoid intake and plasma concentrations in great apes living in captivity, and to compare them to healthy humans. Dietary intakes of humans (n = 20) and, among the great apes, chimpanzees (n = 15) and orangutans (n = 5) were calculated. Plasma retinol (ROH), retinol-binding protein (RBP), retinyl esters, and major carotenoids were analyzed. The great ape diet was higher in VA than in humans, due to high intake of provitamin A carotenoids. Plasma ROH concentrations in great apes were similar to those in humans, but retinyl esters were higher in great apes than in humans. Differences in plasma carotenoid concentrations were observed between great apes and humans. Lutein was the main carotenoid in great apes, while P-carotene was the main carotenoid for humans. RBP concentrations did not differ between great apes and humans. The molar ratio of ROH to RBP was close to 1.0 in both great apes and humans. In conclusion, great apes show homeostatic ROH regulation, with high but physiological retinyl esters circulating in plasma. Furthermore, great apes show great selectivity in their plasmatic carotenoid concentration, which is not explained by dietary intake. KW - vitamin A KW - diet KW - retinol-binding protein KW - chimpanzee KW - orangutan Y1 - 2006 U6 - https://doi.org/10.1002/ajpa.20428 SN - 0002-9483 VL - 131 IS - 2 SP - 236 EP - 242 PB - Wiley CY - Hoboken ER - TY - GEN A1 - Schmiedchen, Bettina A1 - Longardt, Ann Carolin A1 - Bührer, Christoph A1 - Raila, Jens A1 - Loui, Andrea A1 - Schweigert, Florian J. T1 - The Relative Dose Response Test Based on Retinol-Binding Protein 4 Is Not Suitable to Assess Vitamin A Status in Very Low Birth Weight Infants N2 - Background: The relative dose response (RDR) test, which quantifies the increase in serum retinol after vitamin A administration, is a qualitative measure of liver vitamin A stores. Particularly in preterm infants, the feasibility of the RDR test involving blood is critically dependent on small sample volumes. Objectives: This study aimed to assess whether the RDR calculated with retinol-binding protein 4 (RBP4) might be a substitute for the classical retinol-based RDR test for assessing vitamin A status in very preterm infants. Methods: This study included preterm infants with a birth weight below 1,500 g (n = 63, median birth weight 985 g, median gestational age 27.4 weeks) who were treated with 5,000 IU retinyl palmitate intramuscularly 3 times a week for 4 weeks. On day 3 (first vitamin A injection) and day 28 of life (last vitamin A injection), the RDR was calculated and compared using serum retinol and RBP4 concentrations. Results: The concentrations of retinol (p < 0.001) and RBP4 (p < 0.01) increased significantly from day 3 to day 28. On day 3, the median (IQR) retinol-RDR was 27% (8.4-42.5) and the median RBP4-RDR was 8.4% (-3.4 to 27.9), compared to 7.5% (-10.6 to 20.8) and -0.61% (-19.7 to 15.3) on day 28. The results for retinol-RDR and RBP4-RDR revealed no significant correlation. The agreement between retinol-RDR and RBP4-RDR was poor (day 3: Cohen's κ = 0.12; day 28: Cohen's κ = 0.18). Conclusion: The RDR test based on circulating RBP4 is unlikely to reflect the hepatic vitamin A status in preterm infants. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 342 KW - relative dose response test KW - vitamin A KW - preterm infant Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-399853 ER - TY - JOUR A1 - Chupeerach, Chaowanee A1 - Harnroongroj, Talabporn A1 - Phonrat, Benjaluck A1 - Tungtrongchitr, Anchalee A1 - Schweigert, Florian J. A1 - Tungtrongchitr, Rungsunn A1 - Preutthipan, Sangchai T1 - Decreased retinol transport proteins in thai post-menopausal women with Osteporosis JF - The Southeast Asian journal of tropical medicine and public health : official publication of the SEAMEO Regional Tropical Medicine and Public Health Project (TROPMED) N2 - High vitamin A ingestion or high serum retinol have been postulated to increase the risk of fractures and osteoporosis by reduced bone mineral density (BMD). Retinol is carried and transported to the tissues bound to retinol binding protein 4 (RBP4) and transthyretin (TTR). The relationships between retinol, retinol transport protein, retinol binding protein 4 (RBP4) and transthyretin (TTR) and BMD and osteoporosis are unclear. To examine the association between retinol and RBP4 and TTR and osteoporosis, 73 osteoporotic and 71 normal Thai postmenopausal women were studied. RBP4 and retinol levels did not differ between the groups. Serum TTR was significantly higher in control than osteoporotic subjects (89.47 and 144.53 mu g/ml, respectively, p=0.003, Mann-Whitney U test). TTR was positively correlated with BMD at several sites, such as the total radius bone (r=0.172, p=0.008, Spearman rank test). Osteoporosis risk was analyzed with binary logistic regression. Lean elderly Thais with lower TTR levels had a higher risk of osteoporosis. RBP4 and retinol levels had no relationship with disease status among Thai post-menopausal women. These results suggest calcium, minerals, vitamins and the retinol transport protein, transthyretin may be involved in the pathogenesis of osteoporosis. KW - transthyretin KW - vitamin A KW - retinol binding protein 4 KW - post-menopausal Thai women Y1 - 2011 SN - 0125-1562 VL - 42 IS - 6 SP - 1515 EP - 1520 PB - SEAMEO CY - Bangkok ER - TY - JOUR A1 - Raila, Jens A1 - Enjalbert, Francis A1 - Mothes, Ralf A1 - Hurtienne, Andrea A1 - Schweigert, Florian J. T1 - Validation of a new point-of-care assay for determination of ss-carotene concentration in bovine whole blood and plasma JF - Veterinary clinical pathology N2 - Background: beta-Carotene is an important precursor of vitamin A, and is associated with bovine fertility. beta-Carotene concentrations in plasma are used to optimize beta-carotene supplementation in cattle, but measurement requires specialized equipment to separate plasma and extract and measure beta-carotene, either using spectrophotometry or high performance liquid chromatography (HPLC). Objective: The objective of this study was to validate a new 2-step point-of-care (POC) assay for measuring beta-carotene in whole blood and plasma. Methods: beta-carotene concentrations in plasma from 166 cows were measured using HPLC and compared with results obtained using a POC assay, the iCheck-iEx-Carotene test kit. Whole blood samples from 23 of these cattle were also evaluated using the POC assay and compared with HPLC-plasma results from the same 23 animals. The POC assay includes an extraction vial (iEx Carotene) and hand-held photometer (iCheck Carotene). Results: Concentrations of beta-carotene in plasma measured using the POC assay ranged from 0.40 to 15.84 mg/L (n = 166). No differences were observed between methods for assay of plasma (mean +/- SD; n = 166): HPLC-plasma 4.23 +/- 2.35 mg/L; POC-plasma 4.49 +/- 2.36 mg/L. Similar good agreement was found when plasma analyzed using HPLC was compared with whole blood analyzed using the POC system (n = 23): HPLC-plasma 3.46 +/- 2.12 mg/L; POC-whole blood 3.67 +/- 2.29 mg/L. Conclusions: Concentrations of beta-carotene can be measured in blood and plasma from cattle easily and rapidly using a POC assay, and results are comparable to those obtained by the highly sophisticated HPLC method. Immediate feedback regarding beta-carotene deficiency facilitates rapid and appropriate optimization of beta-carotene supplementation in feed. KW - Biomarker KW - HPLC KW - method comparison KW - nutritional supplements KW - vitamin A Y1 - 2012 U6 - https://doi.org/10.1111/j.1939-165X.2012.00400.x SN - 0275-6382 VL - 41 IS - 1 SP - 119 EP - 122 PB - Wiley-Blackwell CY - Malden ER - TY - JOUR A1 - Kuhl, Juliane A1 - Aurich, Jörg E. A1 - Wulf, Manuela A1 - Hurtienne, A. A1 - Schweigert, Florian J. A1 - Aurich, Christine T1 - Effects of oral supplementation with beta-carotene on concentrations of beta-carotene, vitamin A and alpha-tocopherol in plasma, colostrum and milk of mares and plasma of their foals and on fertility in mares JF - Journal of animal physiology and animal nutrition N2 - In this study, effects of oral beta-carotene supplementation to mares (beta-carotene group: 1000 mg/day, n = 15; control group: n = 15) from 2 weeks before foaling until 6 weeks thereafter on concentrations of beta-carotene, vitamin A and a-tocopherol in plasma, colostrum and milk and plasma of their foals were determined. In addition, effects on fertility were studied. Beta-carotene concentrations increased in plasma and colostrum of beta-carotene-supplemented mares compared to control mares (p < 0.05). In mares of both groups, beta-carotene concentrations were higher in colostrum than in milk (p < 0.05). In foals, beta-carotene concentrations increased with colostrum uptake and were higher in foals born to supplemented mares (p < 0.05; control group: 0.0003 +/- 0.0002 mu g/ml on day 0, 0.008 +/- 0.0023 mu g/ml on day 1; beta-carotene group: 0.0005 +/- 0.0003 mu g/ml on day 0, 0.048 +/- 0.018 mu g/ml on day 1). Concentrations of vitamin A and a-tocopherol were higher in colostrum than in milk (p < 0.05) but did not differ between groups. Concentration of a-tocopherol in plasma of mares decreased over time and in foals, increased markedly within 4 days after birth. All but one mare (control group) showed oestrus within 2 weeks post-partum. Occurrence of oestrus did not differ between groups. More mares of the control group (7/7 vs. 5/12 in the beta-carotene group) became pregnant after being bred in first post-partum oestrus (p < 0.05). In conclusion, beta-carotene supplementation to mares increased beta-carotene concentrations in plasma, colostrum and milk of mares and plasma of their foals but had no positive effects on fertility. KW - carotene KW - colostrum KW - foal KW - mare KW - plasma KW - a-tocopherol KW - vitamin A Y1 - 2012 U6 - https://doi.org/10.1111/j.1439-0396.2011.01150.x SN - 0931-2439 VL - 96 IS - 3 SP - 376 EP - 384 PB - Wiley-Blackwell CY - Malden ER - TY - JOUR A1 - Bechir, Mahamat A1 - Schelling, E. A1 - Krämer, K. A1 - Schweigert, Florian J. A1 - Bonfoh, Bassirou A1 - Crump, L. A1 - Tanner, M. A1 - Zinsstag, J. T1 - Retinol assessment among women and children in sahelian mobile pastoralists JF - EcoHealth : conservation medicine, human health, ecosystem sustainability N2 - Micronutrient deficiencies are widespread in developing countries, particularly in remote communities such as mobile pastoralists. The nutritional and vitamin A status of this population is not well-documented in Chad. This study assessed serum retinol levels among women and children under five-year-old in nomadic and semi-nomadic pastoralist and rural-settled communities, who are similarly exposed to risk factors such as gastrointestinal parasitic infection, anaemia and emaciation. The novel method of portable fluorometry was used for the first time to measure beta-carotene and retinol levels in a pastoral nomadic area. Moderate level blood retinol deficiency (< 0.7 mu mol/L) was observed in 5% (CI 1-11) of nomadic, 29% (CI 13-45) of semi-nomadic and 22% (CI 8-35) of sedentary women. In children, 1% (CI 0.1-4), 17% (CI 9-25) and 28% (CI 18-39), respectively, had moderate level blood retinol deficiency. In nomadic communities, women and children had blood retinol levels close to normal. Deficiency of retinol was strongly linked with lifestyle (nomadic, semi-nomadic and settled) among women and lifestyle and age among children. The results support an ecological linkage between human retinol levels and livestock milk retinol. This study shows the feasibility of portable retinol and beta-carotene measurement in human blood as well as human and animal milk under remote field conditions, but the approach requires further validation. KW - vitamin A KW - retinol KW - nomadic pastoralist KW - Chad Y1 - 2012 U6 - https://doi.org/10.1007/s10393-012-0781-7 SN - 1612-9202 VL - 9 IS - 2 SP - 113 EP - 121 PB - Springer CY - New York ER -