@article{UngruBlueherCoenenetal.2012,
  author    = {Ungru, J. and Bl{\"u}her, M. and C{\"o}nen, M. and Raila, Jens and Boston, R. and Vervuert, I.},
  title     = {Effects of body weight reduction on blood adipokines and subcutaneous adipose tissue adipokine mRNA expression profiles in obese ponies},
  series = {The veterinary record},
  volume    = {171},
  journal   = {The veterinary record},
  number    = {21},
  publisher = {British Veterinary Association},
  address   = {London},
  issn      = {0042-4900},
  doi       = {10.1136/vr.100911},
  pages     = {528 -- +},
  year      = {2012},
  abstract  = {Fifteen obese ponies were used in a body weight (BW) reduction programme (BWRP, daily energy intake: 7.0-8.4 MJ/100 kg BW). A frequently sampled intravenous glucose tolerance test was used to assess insulin sensitivity. Subcutaneous adipose tissue biopsies of the tail head were obtained for mRNA gene expression profiles of adiponectin, retinol-binding protein 4 (RBP4), interleukin 6 (IL-6) and macrophage activation marker (CD68) before and after BWRP. Blood samples were analysed for serum leptin, serum RBP4 and plasma adiponectin. Significant BW losses occurred with 7 MJ DE/100 kg BW. Serum leptin and RBP4 were initially similar between insulin-resistant (IR) and insulin-sensitive (IS) ponies, and both significantly decreased during BWRP. Compared with IS ponies, IR ponies initially had significantly lower plasma adiponectin levels. At the beginning of BWRP, mRNA expression of RBP4, adiponectin, IL-6 and CD68 was similar between IR and IS ponies. Plasma adiponectin was strongly related to IR, whereas serum leptin and RBP4 were closely linked to adiposity, independent of insulin sensitivity. Adipose tissue mRNA expression profiles did not clearly reflect these differences. However, the role of subcutaneous adipose tissue in IR remains open.},
  language  = {en}
}
@article{ThawnashomTungtrongchitrChanchayetal.2011,
  author    = {Thawnashom, Kittisak and Tungtrongchitr, Rungsunn and Chanchay, Siriporn and Tungtrongchitr, Anchalee and Raila, Jens and Henze, Andrea and Schweigert, Florian J.},
  title     = {Association between Retinol-Binding protein and renal function among Asian subjects with type 2 diabetes mellitus a cross-sectiona{\"o} study},
  series = {The Southeast Asian journal of tropical medicine and public health : official publication of the SEAMEO Regional Tropical Medicine and Public Health Project (TROPMED)},
  volume    = {42},
  journal   = {The Southeast Asian journal of tropical medicine and public health : official publication of the SEAMEO Regional Tropical Medicine and Public Health Project (TROPMED)},
  number    = {4},
  publisher = {SEAMEO},
  address   = {Bangkok},
  issn      = {0125-1562},
  pages     = {936 -- 945},
  year      = {2011},
  abstract  = {Retinol-binding protein 4 (RBP4) has been suggested as new adipokine, possibly linking obesity to type 2 diabetes mellitus (T2DM). Since the kidneys are the main site of RBP4 degradation and since renal failure is a frequent co-morbid condition with diabetes mellitus, we evaluated the association among RBP4, renal function and T2DM in an Asian population. RBP4 serum levels were analyzed in 110 subjects (50 with T2DM) using an enzyme-linked immunosorbent assay (ELISA). Based on a cut-off estimated glomerular filtration rate (eGFR) of 60 ml/min per 1.73 m(2) (calculated according the abbreviated MDRD formula which uses serum creatinine level, age and gender) and on the T2DM status, subjects were assigned to four subgroups: Group A - controls with an eGFR > 60 ml/min per 1.73 m(2), Group B - controls with an eGFR < 60 ml/min per 1.73 m(2), Group C- T2DM subjects with an eGFR>60 ml/min per 1.73 m(2), and Group D - T2DM subjects with an eGFR <60 ml/ mm per 1.73 m(2). In both the T2DM and control groups, RBP4 levels were higher in subjects with an eGFR < 60 ml/min per 1.73 m(2) than in subjects with an eGFR >60 ml/min per 1.73 m(2). However, the difference was only significant between the control groups (p <0.05). After adjusting for age, gender, BMI, eGFR and the presence of T2DM, eGFR, not T2DM, was associated with plasma RBP4 levels (p<0.05). These results suggest among Asians the eGFR, but not the presence of T2DM, is a major determinant of RBP4 serum levels. The eGFR should be taken into account when evaluating the role of RBP4 in the pathogenesis of insulin resistance and T2DM.},
  language  = {en}
}
@article{StarzonekRoscherBlitheretal.2019,
  author    = {Starzonek, Janine and Roscher, Katja and Blither, Matthias and Blaue, Dominique and Schedlbauer, Carola and Hire, Manuela and Raila, Jens and Vervuert, Ingrid},
  title     = {Effects of a blend of green tea and curcuma extract supplementation on lipopolysaccharide-induced inflammation in horses and ponies},
  series = {PeerJ},
  volume    = {7},
  journal   = {PeerJ},
  publisher = {PeerJ Inc.},
  address   = {London},
  issn      = {2167-8359},
  doi       = {10.7717/peerj.8053},
  pages     = {17},
  year      = {2019},
  abstract  = {Background. In horses and ponies numerous medical conditions are known to be linked with inflammation in different tissues, especially in the liver. Besides affecting other metabolic pathways such as the expression of certain interleukins (IL), inflammation is associated with stress of the endoplasmic reticulum (ER). In particular, ER stress leads to adaptive stress response and can be measured by several markers of inflammatory and stress signalling pathways, like nuclear factor kappa B (NF-kB). Objectives. To investigate lipopolysaccharide (LPS)-induced inflammatory reactions and their modulation in horses and ponies by feeding a polyphenol-rich supplement consisting of green tea and curcuma. Methods. In a cross-over study, 11 animals were allocated to either a placebo or a supplement group and supplemented with 10 g of a blend of green tea and curcuma extract (GCE) or a placebo (calcium carbonate) once daily. After 21 days of supplementation, all animals underwent a LPS challenge to induce moderate systemic inflammation. Blood samples and liver biopsies were taken at standardized time points: 24 hours before and 12 hours after LPS challenge. Inflammatory blood parameters such as serum amyloid A (SAA), haptoglobin and retinol binding protein 4 (RBP4) were measured in serum. Hepatic mRNA levels of selected markers of inflammation such as haptoglobin, tumor necrosis factor alpha (TNF-alpha), IL-1 beta, IL-6, cluster of differentiation 68 (CD68), fibroblast growth factor 21 (FGF-21), NF-kappa B, activating transcription factor 4 (ATF4) were quantified by RT-qPCR. In addition, liver biopsies were examined histologically for inflammatory alterations. Results. Blood markers of acute inflammatory response increased after LPS challenge. In the liver, the proinflammatory cytokine IL-1 beta showed significantly lower mRNA levels after LPS challenge in the supplemented group (P = 0.04) compared to the placebo group. Levels of the hepatic CD68 mRNA increased significantly in the placebo group (P = 0.04). There were no significant differences between supplemented and placebo groups concerning other markers of inflammation and markers of ER stress within the liver. The number of hepatic macrophages were not different after LPS challenge in both feeding groups. Conclusion. LPS was able to induce inflammation but seemed less suitable to induce ER stress in the horses and ponies. The polyphenol-rich supplement showed some potential to reduce inflammatory responses. Nevertheless, the supplementation did not exert an overall anti-inflammatory effect in horses and ponies.},
  language  = {en}
}
@article{ShahidManchiSlunskyetal.2017,
  author    = {Shahid, Muhammad and Manchi, G. and Slunsky, Pavel and Naseer, O. and Fatima, A. and Leo, B. and Raila, Jens},
  title     = {A systemic review of existing serological possibilities to diagnose canine osteoarthritis with a particular focus on extracellular matrix proteoglycans and protein},
  series = {Polish journal of veterinary sciences : PJVS : the journal of Committee of Veterinary Sciences of Polish Academy of Sciences and University of Warmia and Mazury in Olsztyn},
  volume    = {20},
  journal   = {Polish journal of veterinary sciences : PJVS : the journal of Committee of Veterinary Sciences of Polish Academy of Sciences and University of Warmia and Mazury in Olsztyn},
  number    = {1},
  publisher = {De Gruyter},
  address   = {Berlin},
  issn      = {1505-1773},
  doi       = {10.1515/pjvs-2017-0024},
  pages     = {189 -- 201},
  year      = {2017},
  abstract  = {Extra-cellular matrix (ECM) components are important and their stabilization is significant in maintaining normal healthy joint environment. In osteoarthritis (OA), ECM components are altered and indicate disease progression. The joint ECM is composed of proteoglycans (aggrecan, perlecan,inter α-trypsin inhibitor), glycoproteins (fibronectin, lubricin, COMP) and collagen types (most abundantly collagen type II) which represent structural and functional transformation during disease advancement. ECM investigation revealed significant biomarkers of OA that could be used as a diagnostic and therapeutic tool in different canine orthopedic diseases. This review deliberates our current findings of how the components of ECM change at the molecular level during disease progression in canine OA.},
  language  = {en}
}
@article{SchweigertWirthRaila2004,
  author    = {Schweigert, Florian J. and Wirth, Kerstin and Raila, Jens},
  title     = {Characterization of the microheterogeneity of transthyretin in plasma and urine using SELDI-TOF-MS immunoassay},
  year      = {2004},
  language  = {en}
}
@article{SchweigertRailaSehoulietal.2004,
  author    = {Schweigert, Florian J. and Raila, Jens and Sehouli, Jalid and B{\"u}scher, Ulrich},
  title     = {Accumulation of Selected Carotenoids, alpha-tocopherol and Retinol in Human Ovarian Carcinoma Ascitic Fluid},
  issn      = {1421-9697},
  year      = {2004},
  abstract  = {Background: Patients with severe forms of cancer are reported to have reduced concentrations of micronutrients in plasma due to the chronic reduction of food intake and an increased metabolism of these components. The purpose of this study was to evaluate if an accumulation of carotenoids, alpha-tocopherol and retinol in malignant ascitic fluid in women with ovarian cancer might contribute to a loss of these components from plasma. Methods: Blood and ascitic fluid samples obtained from 21 women with ovarian carcinomas and 17 healthy controls were analyzed for retinol, retinol- binding protein (RBP), alpha-tocopherol and carotenoids. Results: Plasma concentrations of all micronutrients were lower in cancer patients compared to controls. Ascitic fluid concentration of all investigated components was comparable (73- 110\%) to plasma. While the mean concentration of retinol in malignant ascites represented 73\% of that in plasma, the concentration of RBP was less than 10\% resulting in an increased mean molar ratio of retinol to RBP from 1.18 to 10.5. Conclusions: The results suggest that lower plasma concentrations of micronutrients in women suffering from ovarian carcinoma are not only caused by a cachexia-induced decrease of food intake and a higher rate of metabolic utilization, but also by a substantial yet not considered transfer from plasma into ascitic fluid possibly associated with plasma lipoproteins. This raises questions with regard to the protective function of these plasma components in ascitic fluid, the consequences of paracentesis on an additional supplementation and finally the possibility to use one or a combination of these components as an additional marker to discriminate between benign and malignant ascites. Copyright (C) 2004 S. Karger AG, Basel},
  language  = {en}
}
@article{SchweigertRailaHaebel1998,
  author    = {Schweigert, Florian J. and Raila, Jens and Haebel, Sophie},
  title     = {Vitamin A excreted in the urine of canines is associated with a Tamm-Horsfall-like Glycoprotein},
  year      = {1998},
  language  = {en}
}
@article{SchweigertRailaEisenachetal.1997,
  author    = {Schweigert, Florian J. and Raila, Jens and Eisenach, C. and Buchholz, Ingeborg},
  title     = {Distribution of vitamin A and retinol-binding-protein (RBP) in plasma, urine and various tissues of canines},
  year      = {1997},
  language  = {en}
}
@article{SchweigertRaila2005,
  author    = {Schweigert, Florian J. and Raila, Jens},
  title     = {Inadequate attempts to measure the microheterogeneity of transthyretin by low-resolution mass spectrometry : Response},
  issn      = {0009-9147},
  year      = {2005},
  language  = {en}
}
@inproceedings{SchuppRailaWitteetal.2012,
  author    = {Schupp, M. and Raila, Jens and Witte, N. and Tuvia, N. and M{\"u}nzner, Matthias},
  title     = {RBP4 and its membrane receptor stra6 control adipogenesis by regulating cellular retinoid homeostasis},
  series = {Diabetologia : journal of the European Association for the Study of Diabetes (EASD)},
  volume    = {55},
  booktitle = {Diabetologia : journal of the European Association for the Study of Diabetes (EASD)},
  publisher = {Springer},
  address   = {New York},
  issn      = {0012-186X},
  pages     = {S93 -- S93},
  year      = {2012},
  language  = {en}
}
@article{SchmiedchenLongardtLouietal.2016,
  author    = {Schmiedchen, Bettina and Longardt, Ann Carolin and Loui, Andrea and Buehrer, Christoph and Raila, Jens and Schweigert, Florian J.},
  title     = {Effect of vitamin A supplementation on the urinary retinol excretion in very low birth weight infants},
  series = {European journal of pediatrics : official organ of the Belgian Pediatric Association},
  volume    = {175},
  journal   = {European journal of pediatrics : official organ of the Belgian Pediatric Association},
  publisher = {Springer},
  address   = {New York},
  issn      = {0340-6199},
  doi       = {10.1007/s00431-015-2647-9},
  pages     = {365 -- 372},
  year      = {2016},
  abstract  = {Despite high-dose vitamin A supplementation of very low birth weight infants (VLBW, <1500 g), their vitamin A status does not improve substantially. Unknown is the impact of urinary retinol excretion on the serum retinol concentration in these infants. Therefore, the effect of high-dose vitamin A supplementation on the urinary vitamin A excretion in VLBW infants was investigated. Sixty-three VLBW infants were treated with vitamin A (5000 IU intramuscular, 3 times/week for 4 weeks); 38 untreated infants were classified as control group. On days 3 and 28 of life, retinol, retinol-binding protein 4 (RBP4), glomerular filtration rate, proteinuria, and Tamm-Horsfall protein were quantified in urine. On day 3 of life, substantial retinol and RBP4 losses were found in both groups, which significantly decreased until day 28. Notwithstanding, the retinol excretion was higher (P<0.01) under vitamin A supplementation as compared to infants of the control group. On day 28 of life, the urinary retinol concentrations were predictive for serum retinol concentrations in the vitamin A treated (P<0.01), but not in the control group (P=0.570). Conclusion: High urinary retinol excretion may limit the vitamin A supplementation efficacy in VLBW infants. Advanced age and thus postnatal kidney maturation seems to be an important contributor in the prevention of urinary retinol losses.},
  language  = {en}
}
@misc{SchmiedchenLongardtBuehreretal.2017,
  author    = {Schmiedchen, Bettina and Longardt, Ann Carolin and B{\"u}hrer, Christoph and Raila, Jens and Loui, Andrea and Schweigert, Florian J.},
  title     = {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},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-399853},
  pages     = {6},
  year      = {2017},
  abstract  = {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.},
  language  = {en}
}
@article{SchedlbauerBlaueRailaetal.2020,
  author    = {Schedlbauer, Carola and Blaue, Dominique and Raila, Jens and Vervuert, Ingrid},
  title     = {Alterations of serum vitamin E and vitamin A concentrations of ponies and horses during experimentally induced obesity},
  series = {Journal of animal physiology and animal nutrition},
  volume    = {104},
  journal   = {Journal of animal physiology and animal nutrition},
  number    = {5},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {0931-2439},
  doi       = {10.1111/jpn.13385},
  pages     = {1501 -- 1508},
  year      = {2020},
  abstract  = {Vitamin A, vitamin E and retinol-binding protein 4 (RBP4) are a focus of current obesity research in humans. The impact of body weight (BW) gain on fat-soluble vitamins and its associated parameters in equines has not been previously reported. Ten Shetland ponies and 9 Warmblood horses, all adult geldings, non-obese and healthy, were fed an excessive energy diet for 20 months to induce BW gain. Serum alpha-tocopherol (vitamin E), retinol (vitamin A), retinol-binding protein 4 (RBP4) and retinol/RBP4 ratio were analysed before BW gain induction and at six timepoints during the BW gaining period. The mean (+/- SD) \% BW gain achieved during two years of excess energy intake was 29.9 +/- 19.4\% for ponies and 17 +/- 6.74\% for horses. Serum alpha-tocopherol increased significantly in ponies and horses during excess energy intake and circulating alpha-tocopherol levels correlated positively with alpha-tocopherol intake (r = .6; p < .001). Serum retinol concentrations showed variations during the study but without relation to intake. Serum RBP4 decreased at the end of the study. The retinol/RBP4 ratio increased with BW gain without differences between ponies and horses. In comparison with human research, the increase in the retinol/RBP4 ratio was unexpected and needs further elucidation.},
  language  = {en}
}
@misc{SchedlbauerBlaueRailaetal.2020,
  author    = {Schedlbauer, Carola and Blaue, Dominique and Raila, Jens and Vervuert, Ingrid},
  title     = {Alterations of serum vitamin E and vitamin A concentrations of ponies and horses during experimentally induced obesity},
  series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {5},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-51951},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-519515},
  pages     = {10},
  year      = {2020},
  abstract  = {Vitamin A, vitamin E and retinol-binding protein 4 (RBP4) are a focus of current obesity research in humans. The impact of body weight (BW) gain on fat-soluble vitamins and its associated parameters in equines has not been previously reported. Ten Shetland ponies and 9 Warmblood horses, all adult geldings, non-obese and healthy, were fed an excessive energy diet for 20 months to induce BW gain. Serum alpha-tocopherol (vitamin E), retinol (vitamin A), retinol-binding protein 4 (RBP4) and retinol/RBP4 ratio were analysed before BW gain induction and at six timepoints during the BW gaining period. The mean (+/- SD) \% BW gain achieved during two years of excess energy intake was 29.9 +/- 19.4\% for ponies and 17 +/- 6.74\% for horses. Serum alpha-tocopherol increased significantly in ponies and horses during excess energy intake and circulating alpha-tocopherol levels correlated positively with alpha-tocopherol intake (r = .6; p < .001). Serum retinol concentrations showed variations during the study but without relation to intake. Serum RBP4 decreased at the end of the study. The retinol/RBP4 ratio increased with BW gain without differences between ponies and horses. In comparison with human research, the increase in the retinol/RBP4 ratio was unexpected and needs further elucidation.},
  language  = {en}
}
@article{RailaWirthChenetal.2004,
  author    = {Raila, Jens and Wirth, Kerstin and Chen, Frank and B{\"u}scer, Ulrich and Dudenhausen, Joachim W. and Schweigert, Florian J.},
  title     = {Excretion of vitamin A in urine of women during Normal pregnancy and pregnancy complications},
  issn      = {0250-6807},
  year      = {2004},
  abstract  = {Background/Aims: The renal function, including the excretion of low-molecular-weight proteins, changes during pregnancy and may cause a urinary excretion of retinol-binding protein (RBP). Whether it is accompanied by a substantial loss of vitamin A ( retinol) has not been established yet. We therefore determined the excretion of retinol and RBP in urine of pregnant women. Methods: The study involved analyses of urine samples from 40 healthy pregnant women and 29 women with pregnancy complications during the third trimester. Analyses of plasma and urine of 7 healthy women and 5 women with pregnancy complications were also carried out 6 weeks antepartum, at time of delivery and 1 week postpartum. Results: Urinary retinol was higher in women who suffered from pregnancy disorders with an influence on maternal metabolism ( p < 0.01). RBP was excreted at substantial concentrations in the urine of all 69 women, but there were no differences between the groups. Women with a concomitant excretion of retinol had higher levels of urinary RBP than those without a retinol excretion ( p < 0.05). Differences in plasma retinol and RBP were not significant. Conclusion: The excretion of urinary retinol may increase significantly during pregnancy complications, which needs further clarification to which extent this condition may negatively affect the vitamin A status in such women. Copyright (C) 2004 S. Karger AG, Basel},
  language  = {en}
}
@book{RailaWirthBuescheretal.2001,
  author    = {Raila, Jens and Wirth, Kerstin and B{\"u}scher, Ulrich and Dudenhausen, Joachim W. and Schweigert, Florian J.},
  title     = {Einfluss normaler und pathologischer Schwangerschaftsverl{\"a}ufe auf die renale Ausscheidung von Vitamin A und Retinol-Bindungsprotein},
  year      = {2001},
  language  = {de}
}
@article{RailaWillnowSchweigert2005,
  author    = {Raila, Jens and Willnow, T. E. and Schweigert, Florian J.},
  title     = {Megalin-mediated reuptake of retinol in the kidneys of mice is essential for vitamin A homeostasis},
  issn      = {0022-3166},
  year      = {2005},
  abstract  = {The reuptake of retinol (ROH) and retinol-binding protein (RBP) in the kidneys is mediated by the endocytic receptor megalin, suggesting an important role for this receptor in vitamin A (VA) metabolism. We examined the extent to which megalin deficiency may affect urinary ROH excretion, levels of ROH and RBP in plasma, as well as storage of VA in liver and kidney. For this purpose, mice with a kidney-specific megalin gene defect (megalin(lox/lox):; apoE(Cre)) and control mice (megalin(lox/lox)) were fed either a basal diet containing 4500 retinol equivalents (RE)/kg diet or a diet without VA during experimental periods of 42 and 84 d. Urinary ROH excretion was observed only in megalin(lox/lox); apoE(Cre) mice (P < 0.0001, 2-way ANOVA) and not in the controls. Plasma ROH and RBP differed only by diet (P < 0.05), but not genotype (P = 0.615). A major effect of megalin deficiency, however, was evident in retinyl ester levels in the liver (P < 0.05), which were similar to 37\% lower than those in megalin(lox/lox) controls (P < 0.05, Student's t test) during the 84-d period of dietary VA deprivation. Kidney levels of VA were not affected by the receptor gene defect. The findings demonstrate that urinary ROH excretion caused by megalin deficiency requires accelerated mobilization of hepatic VA stores to maintain normal plasma ROH levels, which suggests that megalin plays an essential role in systemic VA homeostasis},
  language  = {en}
}
@article{RailaStohrerForterreetal.2004,
  author    = {Raila, Jens and Stohrer, M. and Forterre, Simone and Stangassinger, M. and Schweigert, Florian J.},
  title     = {Effect of exercise on the mobilization of retinol and retinyl esters in plasma of sled dogs},
  year      = {2004},
  abstract  = {Fasting dogs do transport vitamin A (VA) in plasma not only as retinol but predominantly as retinyl esters. Contrary to retinol, nothing is known concerning the effects of athletic performance on plasma retinyl ester concentrations. The aim of this study was therefore to examine whether physical stress because of exercise and modification of the oxidative stress by supplementation of alpha-tocopherol influences the concentrations of retinol and retinyl esters in plasma of sled dogs. The study was carried out on 41 trained adult sled dogs, which were randomly assigned into two groups. One group (19 dogs) was daily substituted with 50 mg DL-alpha-tocopheryl acetate per kilogram body weight and the control group (22 dogs) was maintained on a basal diet during 3 months prior to exercise. The plasma concentrations of retinol, retinyl esters, alpha-tocopherol and triglycerides were measured immediately before, directly after and 24 h after exercise. The supplementation of alpha-tocopheryl acetate had no effect on plasma retinol and retinyl ester concentrations at any measurement time point. However, retinyl ester levels doubled in the non- supplemented group immediately after the race (p < 0.001), whereas in the supplemented group similar high levels were observed not until 24 h post-racing (p < 0.001). The high levels of retinyl esters were paralleled to some extent by an increase in plasma triglyceride concentrations, which were significantly higher 24 h post-racing than immediately before (p < 0.001) and after exercise (p < 0.001) in both groups. The increase in retinyl ester concentrations might be indicative of their mobilization from liver and adipose tissue. Whether plasma retinyl esters can be used as an indicator for the extent of nutrient mobilization during and post-exercise in sled dogs remains to be elucidated},
  language  = {en}
}
@article{RailaSchweigertStanitznigetal.2017,
  author    = {Raila, Jens and Schweigert, Florian J. and Stanitznig, A. and Lambacher, B. and Franz, S. and Baldermann, Susanne and Wittek, T.},
  title     = {No detectable carotenoid concentrations in serum of llamas and alpacas},
  series = {Journal of animal physiology and animal nutrition},
  volume    = {101},
  journal   = {Journal of animal physiology and animal nutrition},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {0931-2439},
  doi       = {10.1111/jpn.12638},
  pages     = {629 -- 634},
  year      = {2017},
  abstract  = {Carotenoids are lipid-soluble pigments and important for a variety of physiological functions. They are major dietary vitamin A precursors and act as lipophilic antioxidants in a variety of tissues and are associated with important health benefits in humans and animals. All animals must acquire carotenoids from their diet, but to our knowledge, there are no studies investigating the intestinal carotenoid absorption and their blood concentrations in New World camelids. The present study aimed to assess the serum concentrations of selected carotenoids in llamas (n=13) and alpacas (n=27). Serum carotenoids as well as retinol (vitamin A) and -tocopherol (vitamin E) were determined by high-performance liquid chromatography coupled with mass spectrometry and these were unable to detect any carotenoids (- and -carotene, - and -cryptoxanthin, lutein, zeaxanthin, lycopene) in the samples. The concentrations of retinol in alpacas (2.89 +/- 1.13mol/l; mean +/- SD) were higher (p=0.024) than those found in llamas (2.05 +/- 0.87mol/l); however, the concentrations of -tocopherol were not significantly (p=0.166) different (llamas: 3.98 +/- 1.83mol/l; alpacas: 4.95 +/- 2.14mol/l). The results show that both llamas and alpacas are not able to absorb intact carotenoids, but efficiently convert provitamin A carotenoids to retinol.},
  language  = {en}
}
@article{RailaSchweigertKohn2011,
  author    = {Raila, Jens and Schweigert, Florian J. and Kohn, Barbara},
  title     = {C-reactive protein concentrations in serum of dogs with naturally occurring renal disease},
  series = {Journal of veterinary diagnostic investigation},
  volume    = {23},
  journal   = {Journal of veterinary diagnostic investigation},
  number    = {4},
  publisher = {Sage Publ.},
  address   = {Thousand Oaks},
  issn      = {1040-6387},
  doi       = {10.1177/1040638711407896},
  pages     = {710 -- 715},
  year      = {2011},
  abstract  = {The current study was undertaken to investigate the relation between serum C-reactive protein (CRP) concentrations and parameters of renal function in dogs with naturally occurring renal disease. Dogs were assigned to groups according to plasma creatinine concentration, urinary protein-to-creatinine ratio (UP/UC), and exogenous plasma creatinine clearance (P-Cl(Cr)) rates. Group A (healthy control dogs; n = 8): non-azotemic (plasma creatinine <125 mu mol/l) and nonproteinuric (UP/UC <0.2), with P-Cl(Cr) rates >90 ml/min/m(2); group B (n = 11): non-azotemic, nonproteinuric dogs with reduced P-Cl(Cr) rates (50-89 ml/min/m(2)); group C (n = 7): azotemic, borderline proteinuric dogs (P-Cl(Cr) rates: 22-67 ml/min/m(2)); and group D (n = 6): uremic, proteinuric dogs (not tested for P-Cl(Cr)). The serum CRP concentrations were measured via commercial enzyme-linked immunosorbent assay. The CRP concentrations in the clinically healthy dogs (group A) ranged from 2.09 mg/l to 8.60 mg/l (median: 3.21 mg/l). In comparison with dogs of group A, median CRP concentrations were significantly (P < 0.01) elevated in dogs of group B (17.6 mg/l, range: 17.0-19.2 mg/l), group C (24.8 mg/l, range: 18.0-32.5 mg/l), and group D (59.7 mg/l, range: 17.7-123 mg/l). Serum CRP was significantly related to P-Cl(Cr) (r = -0.83; P < 0.001), plasma creatinine (r = 0.81; P < 0.001), UP/UC (r = 0.70; P < 0.001), and leukocytes (r = 0.49; P < 0.01). The significant relations between serum CRP concentrations and biochemical parameters of kidney function in plasma and urine suggest that a stimulation of the acute phase response is implicated in the pathogenesis of canine renal disease.},
  language  = {en}
}
@article{RailaSchweigertKohn2014,
  author    = {Raila, Jens and Schweigert, Florian J. and Kohn, Barbara},
  title     = {Relationship between urinary Tamm-Horsfall protein excretion and renal function in dogs with naturally occurring renal disease},
  series = {Veterinary clinical pathology},
  volume    = {43},
  journal   = {Veterinary clinical pathology},
  number    = {2},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0275-6382},
  doi       = {10.1111/vcp.12143},
  pages     = {261 -- 265},
  year      = {2014},
  abstract  = {Background Tamm-Horsfall protein (THP) is physiologically excreted in urine, but little is known about the role of THP in the diagnosis of renal disease in dogs. Objective The aim of this study was to evaluate to which extent naturally occurring renal disease affects the urinary excretion of THP. Methods Dogs were divided into 5 groups according to plasma creatinine concentration, urinary protein-to-creatinine ratio (UP/UC), and exogenous plasma creatinine clearance (P-ClCr) rates: Group A (healthy control dogs; n=8), nonazotemic and nonproteinuric dogs, with P-ClCr rates > 90mL/min/m2; group B (n=25), nonazotemic and nonproteinuric dogs with reduced P-ClCr rates (51-89mL/min/m2); group C (n=7), nonazotemic but proteinuric dogs with P-ClCr rates 53-98mL/min/m2; group D (n=8), azotemic and borderline proteinuric dogs (P-ClCr rates: 22-45mL/min/m2); and group E (n=15), azotemic and proteinuric dogs (not tested for P-ClCr). THP was measured by quantitative Western blot analysis, and the ratio of THP-to-urinary creatinine (THP/UC) was calculated. Results The THP/UC concentrations were not different among dogs of groups A-D, but were reduced in dogs of group E (P<.001). THP/UC correlated negatively with serum creatinine (P<.01) and UP/UC (P<.01), but was not significantly associated with P-ClCr. Conclusions Decreased levels of THP/UC were present in moderately to severely azotemic and proteinuric dogs. This suggests tubular injury in these dogs and that THP might be useful as urinary marker to study the pathogenesis of renal disease.},
  language  = {en}
}
@misc{RailaSchweigertKohn2017,
  author    = {Raila, Jens and Schweigert, Florian J. and Kohn, Barbara},
  title     = {C-reactive protein concentrations in serum of dogs with naturally occurring renal disease},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-402942},
  pages     = {6},
  year      = {2017},
  abstract  = {The current study was undertaken to investigate the relation between serum C-reactive protein (CRP) concentrations and parameters of renal function in dogs with naturally occurring renal disease. Dogs were assigned to groups according to plasma creatinine concentration, urinary protein-to-creatinine ratio (UP/UC), and exogenous plasma creatinine clearance (P-Cl(Cr)) rates. Group A (healthy control dogs; n = 8): non-azotemic (plasma creatinine <125 mu mol/l) and nonproteinuric (UP/UC <0.2), with P-Cl(Cr) rates >90 ml/min/m(2); group B (n = 11): non-azotemic, nonproteinuric dogs with reduced P-Cl(Cr) rates (50-89 ml/min/m(2)); group C (n = 7): azotemic, borderline proteinuric dogs (P-Cl(Cr) rates: 22-67 ml/min/m(2)); and group D (n = 6): uremic, proteinuric dogs (not tested for P-Cl(Cr)). The serum CRP concentrations were measured via commercial enzyme-linked immunosorbent assay. The CRP concentrations in the clinically healthy dogs (group A) ranged from 2.09 mg/l to 8.60 mg/l (median: 3.21 mg/l). In comparison with dogs of group A, median CRP concentrations were significantly (P < 0.01) elevated in dogs of group B (17.6 mg/l, range: 17.0-19.2 mg/l), group C (24.8 mg/l, range: 18.0-32.5 mg/l), and group D (59.7 mg/l, range: 17.7-123 mg/l). Serum CRP was significantly related to P-Cl(Cr) (r = -0.83; P < 0.001), plasma creatinine (r = 0.81; P < 0.001), UP/UC (r = 0.70; P < 0.001), and leukocytes (r = 0.49; P < 0.01). The significant relations between serum CRP concentrations and biochemical parameters of kidney function in plasma and urine suggest that a stimulation of the acute phase response is implicated in the pathogenesis of canine renal disease.},
  language  = {en}
}
@article{RailaSchweigert2001,
  author    = {Raila, Jens and Schweigert, Florian J.},
  title     = {Zur Bedeutung der Nieren im Vitamin-Stoffwechsel},
  year      = {2001},
  language  = {de}
}
@article{RailaRohnSchweigertetal.2011,
  author    = {Raila, Jens and Rohn, Sascha and Schweigert, Florian J. and Abraham, Getu},
  title     = {Increased antioxidant capacity in the plasma of dogs after a single oral dosage of tocotrienols},
  series = {The British journal of nutrition : an international journal devoted to the science of human and animal nutrition},
  volume    = {106},
  journal   = {The British journal of nutrition : an international journal devoted to the science of human and animal nutrition},
  number    = {7},
  publisher = {Cambridge Univ. Press},
  address   = {Cambridge},
  issn      = {0007-1145},
  doi       = {10.1017/S0007114511000511},
  pages     = {S116 -- S119},
  year      = {2011},
  abstract  = {The intestinal absorption of tocotrienols (TCT) in dogs is, to our knowledge, so far unknown. Adult Beagle dogs (n 8) were administered a single oral dosage of a TCT-rich fraction (TRF; 40 mg/kg body weight) containing 32\% alpha-TCT, 2\% beta-TCT, 27\% gamma-TCT, 14\% delta-TCT and 25\% alpha-tocopherol (alpha-TCP). Blood was sampled at baseline (fasted), 1, 2, 3, 4, 5, 6, 8 and 12 h after supplementation. Plasma and chylomicron concentrations of TCT and alpha-TCP were measured at each time point. Plasma TAG were measured enzymatically, and plasma antioxidant capacity was assessed by the Trolox equivalent antioxidant capacity assay. In fasted dogs, levels of TCT were 0.07 (SD 0.03) mu mol/l. Following the administration of the TRF, total plasma TCT peaked at 2 h (7.16 (SD 3.88) mu mol/l; P<0.01) and remained above baseline levels (0.67 (SD 0.44) mu mol/l; P, 0.01) at 12 h. The TCT response in chylomicrons paralleled the increase in TCT in plasma with a maximum peak (3.49 (SD 2.06) mu mol/l; P, 0.01) at 2 h post-dosage. alpha-TCP was the major vitamin E detected in plasma and unaffected by TRF supplementation. The Trolox equivalent values increased from 2 h (776 (SD 51.2) mu mol/l) to a maximum at 12 h (1130 (SD 7.72) mmol/l; P<0.01). The results show that TCT are detected in postprandial plasma of dogs. The increase in antioxidant capacity suggests a potential beneficial role of TCT supplementation in the prevention or treatment of several diseases in dogs.},
  language  = {en}
}
@article{RailaNeumannSchweigert2003,
  author    = {Raila, Jens and Neumann, U. and Schweigert, Florian J.},
  title     = {Immunochemical Localization of Megalin, Retinol-binding protein and Tamm-Horsfall Glycoprotein in the Kidneys of Dogs},
  year      = {2003},
  language  = {en}
}
@article{RailaMathewsSchweigert2001,
  author    = {Raila, Jens and Mathews, U. and Schweigert, Florian J.},
  title     = {Plasma transport and tissue distribution of ß-carotene, vitamin A and retinol-binding protein in domestic cats},
  year      = {2001},
  language  = {en}
}
@misc{RailaKawashimaSauerweinetal.2017,
  author    = {Raila, Jens and Kawashima, Chiho and Sauerwein, Helga and H{\"u}lsmann, Nadine and Knorr, Christoph and Myamoto, Akio and Schweigert, Florian J.},
  title     = {Validation of blood vitamin A concentrations in cattle: comparison of a new cow-side test (iCheck™ FLUORO) with high-performance liquid chromatography (HPLC)},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-401978},
  pages     = {6},
  year      = {2017},
  abstract  = {Background: Plasma concentration of retinol is an accepted indicator to assess the vitamin A (retinol) status in cattle. However, the determination of vitamin A requires a time consuming multi-step procedure, which needs specific equipment to perform extraction, centrifugation or saponification prior to high-performance liquid chromatography (HPLC). Methods: The concentrations of retinol in whole blood (n = 10), plasma (n = 132) and serum (n = 61) were measured by a new rapid cow-side test (iCheck™ FLUORO) and compared with those by HPLC in two independent laboratories in Germany (DE) and Japan (JP). Results: Retinol concentrations in plasma ranged from 0.033 to 0.532 mg/L, and in serum from 0.043 to 0.360 mg/L (HPLC method). No significant differences in retinol levels were observed between the new rapid cow-side test and HPLC performed in different laboratories (HPLC vs. iCheck™ FLUORO: 0.320 ± 0.047 mg/L vs. 0.333 ± 0.044 mg/L, and 0.240 ± 0.096 mg/L vs. 0.241 ± 0.069 mg/L, lab DE and lab JP, respectively). A similar comparability was observed when whole blood was used (HPLC vs. iCheck™ FLUORO: 0.353 ± 0.084 mg/L vs. 0.341 ± 0.064 mg/L). Results showed a good agreement between both methods based on correlation coefficients of r2 = 0.87 (P < 0.001) and Bland-Altman blots revealed no significant bias for all comparison. Conclusions: With the new rapid cow-side test (iCheck™ FLUORO) retinol concentrations in cattle can be reliably assessed within a few minutes and directly in the barn using even whole blood without the necessity of prior centrifugation. The ease of the application of the new rapid cow-side test and its portability can improve the diagnostic of vitamin A status and will help to control vitamin A supplementation in specific vitamin A feeding regimes such as used to optimize health status in calves or meat marbling in Japanese Black cattle.},
  language  = {en}
}
@article{RailaKawashimaSauerweinetal.2017,
  author    = {Raila, Jens and Kawashima, Chiho and Sauerwein, Helga and H{\"u}lsmann, Nadine and Knorr, Christoph and Myamoto, Akio and Schweigert, Florian J.},
  title     = {Validation of blood vitamin A concentrations in cattle: comparison of a new cow-side test (iCheck™ FLUORO) with high-performance liquid chromatography (HPLC)},
  series = {BMC veterinary research},
  volume    = {13},
  journal   = {BMC veterinary research},
  publisher = {BioMed Central},
  address   = {London},
  doi       = {10.1186/s12917-017-1042-3},
  year      = {2017},
  abstract  = {Background: Plasma concentration of retinol is an accepted indicator to assess the vitamin A (retinol) status in cattle. However, the determination of vitamin A requires a time consuming multi-step procedure, which needs specific equipment to perform extraction, centrifugation or saponification prior to high-performance liquid chromatography (HPLC). Methods: The concentrations of retinol in whole blood (n = 10), plasma (n = 132) and serum (n = 61) were measured by a new rapid cow-side test (iCheck™ FLUORO) and compared with those by HPLC in two independent laboratories in Germany (DE) and Japan (JP). Results: Retinol concentrations in plasma ranged from 0.033 to 0.532 mg/L, and in serum from 0.043 to 0.360 mg/L (HPLC method). No significant differences in retinol levels were observed between the new rapid cow-side test and HPLC performed in different laboratories (HPLC vs. iCheck™ FLUORO: 0.320 ± 0.047 mg/L vs. 0.333 ± 0.044 mg/L, and 0.240 ± 0.096 mg/L vs. 0.241 ± 0.069 mg/L, lab DE and lab JP, respectively). A similar comparability was observed when whole blood was used (HPLC vs. iCheck™ FLUORO: 0.353 ± 0.084 mg/L vs. 0.341 ± 0.064 mg/L). Results showed a good agreement between both methods based on correlation coefficients of r2 = 0.87 (P < 0.001) and Bland-Altman blots revealed no significant bias for all comparison. Conclusions: With the new rapid cow-side test (iCheck™ FLUORO) retinol concentrations in cattle can be reliably assessed within a few minutes and directly in the barn using even whole blood without the necessity of prior centrifugation. The ease of the application of the new rapid cow-side test and its portability can improve the diagnostic of vitamin A status and will help to control vitamin A supplementation in specific vitamin A feeding regimes such as used to optimize health status in calves or meat marbling in Japanese Black cattle.},
  language  = {en}
}
@article{RailaForterreSchweigert2005,
  author    = {Raila, Jens and Forterre, Simone and Schweigert, Florian J.},
  title     = {Markerproteine im Harn von Hunden},
  isbn      = {3-8304-1051-4},
  year      = {2005},
  language  = {de}
}
@article{RailaForterreSchweigert2005,
  author    = {Raila, Jens and Forterre, Simone and Schweigert, Florian J.},
  title     = {Physiologische und pathophysiologische Grundlagen der Proteinurie : eine {\"U}bersicht},
  year      = {2005},
  language  = {de}
}
@article{RailaForterreSchweigert2005,
  author    = {Raila, Jens and Forterre, Simone and Schweigert, Florian J.},
  title     = {Physiology and pathophysiology of proteinuria : a review},
  issn      = {0005-9366},
  year      = {2005},
  abstract  = {The term proteinuria is taken to mean abnormally high protein excretion in the urine. Proteinuria is the consequence of glomerular filtration of plasma proteins, their subsequent reabsorption by the proximal tubular cells and secretion of protein by the tubular cells and distal urinary tract. In physiological conditions, the structural integry of the glomerular filtration barrier prevents the abnormal passage of albumin (molecular mass 66 kDa) and high-molecular- weight proteins (> 66 kDa),whereas the passage of low-molecular-weight proteins (< 66 kDa) is almost completely unrestricted. Proteins that arrive the tubular lumen are reabsorbed by endocytosis after binding to the megalin-cubilin complex. An increased load of proteins in the tubular lumen leads to the saturation of the reabsorptive mechanism and higher urinary protein excretion. Proteinuria can originate from prerenal, renal and postrenal causes. Elevated tubular protein concentrations have been recognized to be toxic to tubular cells and associated with the progression of chronic renal disease. Therefore, the quantitative and qualitative evaluation of proteinuria is important for the diagnosis of renal disease},
  language  = {en}
}
@article{RailaForterreSchweigert2003,
  author    = {Raila, Jens and Forterre, Simone and Schweigert, Florian J.},
  title     = {Die Bedeutung von Megalin in der Pathogenese der tubul{\"a}ren Proteinurie des Hundes},
  isbn      = {3-936815-65-8},
  year      = {2003},
  language  = {de}
}
@article{RailaForterreSchweigert2003,
  author    = {Raila, Jens and Forterre, Simone and Schweigert, Florian J.},
  title     = {Levels of retinol and retinyl esters in plasma and urine of dogs with urolithiasis},
  year      = {2003},
  language  = {en}
}
@article{RailaEnjalbertMothesetal.2012,
  author    = {Raila, Jens and Enjalbert, Francis and Mothes, Ralf and Hurtienne, Andrea and Schweigert, Florian J.},
  title     = {Validation of a new point-of-care assay for determination of ss-carotene concentration in bovine whole blood and plasma},
  series = {Veterinary clinical pathology},
  volume    = {41},
  journal   = {Veterinary clinical pathology},
  number    = {1},
  publisher = {Wiley-Blackwell},
  address   = {Malden},
  issn      = {0275-6382},
  doi       = {10.1111/j.1939-165X.2012.00400.x},
  pages     = {119 -- 122},
  year      = {2012},
  abstract  = {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.},
  language  = {en}
}
@article{RailaEisenachBuchholzetal.1997,
  author    = {Raila, Jens and Eisenach, C. and Buchholz, Ingeborg and Schweigert, Florian J.},
  title     = {Verteilung von Vitamin A und Retinol-Bindungs-Protein (RBP) in verschiedenen Geweben von Caniden},
  year      = {1997},
  language  = {de}
}
@article{RailaEisenachBuchholzetal.1997,
  author    = {Raila, Jens and Eisenach, C. and Buchholz, Ingeborg and Schweigert, Florian J.},
  title     = {Distribution of vitamin A and retinol-binding-protein (RBP) in various tissue of dogs and reccoon dogs},
  year      = {1997},
  language  = {en}
}
@article{RailaBuchholzSchweigert1997,
  author    = {Raila, Jens and Buchholz, Ingeborg and Schweigert, Florian J.},
  title     = {Untersuchungen zur Vitamin-A-Bindung im Harn von Hunden},
  year      = {1997},
  language  = {de}
}
@article{RailaBuchholzAupperleetal.2000,
  author    = {Raila, Jens and Buchholz, Ingeborg and Aupperle, Heike and Raila, Jens and Schoon, Heinz-Adolf and Schweigert, Florian J.},
  title     = {The distribution of vitamin A and retinol-binding protein (RBP) in the blood plasma, urine, liver and kidney of carnivores},
  year      = {2000},
  language  = {en}
}
@article{RailaBokBuchholzetal.1997,
  author    = {Raila, Jens and Bok, V. and Buchholz, Ingeborg and Schweigert, Florian J.},
  title     = {Untersuchungen zum Vitamin-A-Stoffwechsel der Niere des Hundes},
  year      = {1997},
  language  = {de}
}
@article{RailaBokBuchholzetal.1997,
  author    = {Raila, Jens and Bok, V. and Buchholz, Ingeborg and Schweigert, Florian J.},
  title     = {Investigations on the excretion of vitamin A as retinol and retinyl esters bound to a high molecular complex},
  year      = {1997},
  language  = {en}
}
@article{PasslackSchmiedchenRailaetal.2016,
  author    = {Passlack, Nadine and Schmiedchen, Bettina and Raila, Jens and Schweigert, Florian J. and Stumpff, Friederike and Kohn, Barbara and Neumann, Konrad and Zentek, Juergen},
  title     = {Impact of Increasing Dietary Calcium Levels on Calcium Excretion and Vitamin D Metabolites in the Blood of Healthy Adult Cats},
  series = {PLoS one},
  volume    = {11},
  journal   = {PLoS one},
  publisher = {PLoS},
  address   = {San Fransisco},
  issn      = {1932-6203},
  doi       = {10.1371/journal.pone.0149190},
  pages     = {47 -- 67},
  year      = {2016},
  abstract  = {Background Dietary calcium (Ca) concentrations might affect regulatory pathways within the Ca and vitamin D metabolism and consequently excretory mechanisms. Considering large variations in Ca concentrations of feline diets, the physiological impact on Ca homeostasis has not been evaluated to date. In the present study, diets with increasing concentrations of dicalcium phosphate were offered to ten healthy adult cats (Ca/phosphorus (P): 6.23/6.02, 7.77/7.56, 15.0/12.7, 19.0/17.3, 22.2/19.9, 24.3/21.6 g/kg dry matter). Each feeding period was divided into a 10-day adaptation and an 8-day sampling period in order to collect urine and faeces. On the last day of each feeding period, blood samples were taken. Results Urinary Ca concentrations remained unaffected, but faecal Ca concentrations increased (P < 0.001) with increasing dietary Ca levels. No effect on whole and intact parathyroid hormone levels, fibroblast growth factor 23 and calcitriol concentrations in the blood of the cats were observed. However, the calcitriol precursors 25(OH)D-2 and 25(OH)D-3, which are considered the most useful indicators for the vitamin D status, decreased with higher dietary Ca levels (P = 0.013 and P = 0.033). Increasing dietary levels of dicalcium phosphate revealed an acidifying effect on urinary fasting pH (6.02) and postprandial pH (6.01) (P < 0.001), possibly mediated by an increase of urinary phosphorus (P) concentrations (P < 0.001). Conclusions In conclusion, calcitriol precursors were linearly affected by increasing dietary Ca concentrations. The increase in faecal Ca excretion indicates that Ca homeostasis of cats is mainly regulated in the intestine and not by the kidneys. Long-term studies should investigate the physiological relevance of the acidifying effect observed when feeding diets high in Ca and P.},
  language  = {en}
}
@article{NaglLouiRailaetal.2009,
  author    = {Nagl, Britta and Loui, Andrea and Raila, Jens and Felderhoff-Mueser, Ursula and Obladen, Michael and Schweigert, Florian J.},
  title     = {Urinary vitamin A excretion in very low birth weight infants},
  issn      = {0931-041X},
  doi       = {10.1007/s00467-008-0965-0},
  year      = {2009},
  abstract  = {Vitamin A (VA) deficiency in very low birth weight (VLBW) infants is associated with an increased risk for disorders related to kidney and lung maturation and function. VA losses through increased urinary retinol (ROH) excretion might contribute to this deficiency risk. The mechanism accounting for ROH loss in the urine has not yet been clarified. The aim of this study was to assess the excretion of ROH, retinol-binding protein 4 (RBP4) and transthyretin (TTR) in urine from VLBW infants in comparison with that in term infants in relation to kidney function. Urine specimens were collected from 15 VLBW infants (birth weight < 1,500 g) as well as from 20 term infants during the first 2 days after birth. ROH in urine was detectable in 14 of the 15 VLBW infants at a median concentration of 234 nmol/g creatinine. In the group of term infants, 17 of the 20 excreted ROH, but at an approximately five-times lower concentration (P<0.001). Excretion of RBP4 and TTR was also much higher in VLBW infants (both P<0.001). The urinary ROH excretion in VLBW infants may be related to the impaired tubular handling of its carrier proteins RBP4 and TTR. Thus, ROH excretion might contribute to an increased risk of VA deficiency, especially in VLBW infants.},
  language  = {en}
}
@article{MuenznerTuviaDeutschmannetal.2013,
  author    = {M{\"u}nzner, Matthias and Tuvia, Neta and Deutschmann, Claudia and Witte, Nicole and Tolkachov, Alexander and Valai, Atijeh and Henze, Andrea and Sander, Leif E. and Raila, Jens and Schupp, Michael},
  title     = {Retinol-binding protein 4 and its membrane receptor STRA6 control adipogenesis by regulating cellular retinoid homeostasis and retinoic acid receptor alpha activity},
  series = {Molecular and cellular biology},
  volume    = {33},
  journal   = {Molecular and cellular biology},
  number    = {20},
  publisher = {American Society for Microbiology},
  address   = {Washington},
  issn      = {0270-7306},
  doi       = {10.1128/MCB.00221-13},
  pages     = {4068 -- 4082},
  year      = {2013},
  abstract  = {Retinoids are vitamin A (retinol) derivatives and complex regulators of adipogenesis by activating specific nuclear receptors, including the retinoic acid receptor (RAR) and retinoid X receptor (RXR). Circulating retinol-binding protein 4 (RBP4) and its membrane receptor STRA6 coordinate cellular retinol uptake. It is unknown whether retinol levels and the activity of RAR and RXR in adipocyte precursors are linked via RBP4/STRA6. Here, we show that STRA6 is expressed in precursor cells and, dictated by the apo-and holo-RBP4 isoforms, mediates bidirectional retinol transport that controls RAR alpha activity and subsequent adipocyte differentiation. Mobilization of retinoid stores in mice by inducing RBP4 secretion from the liver activated RAR alpha signaling in the precursor cell containing the stromal-vascular fraction of adipose tissue. Retinol-loaded holo-RBP4 blocked adipocyte differentiation of cultured precursors by activating RAR alpha. Remarkably, retinol-free apo-RBP4 triggered retinol efflux that reduced cellular retinoids, RAR alpha activity, and target gene expression and enhanced adipogenesis synergistically with ectopic STRA6. Thus, STRA6 in adipocyte precursor cells links nuclear RAR alpha activity to the circulating RBP4 isoforms, whose ratio in obese mice was shifted toward limiting the adipogenic potential of their precursors. This novel cross talk identifies a retinoldependent metabolic function of RBP4 that may have important implications for the treatment of obesity.},
  language  = {en}
}
@article{MuellerAltenkampRailaetal.2011,
  author    = {M{\"u}ller, Kerstin E. and Altenkamp, Rainer and Raila, Jens and Schmidt, Daniel and Dietrich, Robert and Hurtienne, Andrea and Wink, Michael and Krone, Oliver and Brunnberg, Leo and Schweigert, Florian J.},
  title     = {Plasma concentration of alpha-tocopherol in different free-ranging birds of prey},
  series = {European journal of wildlife research},
  volume    = {57},
  journal   = {European journal of wildlife research},
  number    = {5},
  publisher = {Springer},
  address   = {New York},
  issn      = {1612-4642},
  doi       = {10.1007/s10344-011-0516-z},
  pages     = {1043 -- 1049},
  year      = {2011},
  abstract  = {In this study, we investigated the alpha-tocopherol plasma concentrations in healthy free-ranging nestlings of the white-tailed sea eagle (Haliaeetus albicilla) (n=32), osprey (Pandion haliaetus) (n=39), northern goshawk (Accipiter gentilis) (n=25), common buzzard (Buteo buteo) (n=31), and honey buzzard (Pernis apivorus) (n=18) as well as of free-ranging adults of the white-tailed sea eagle (n=10), osprey (n=31), and northern goshawk (n=45). alpha-Tocopherol plasma concentrations were determined by reverse-phase high-performance liquid chromatography. alpha-Tocopherol plasma concentrations in nestlings of osprey, white-tailed sea eagle, and northern goshawk did not differ significantly amongst the species, but the common buzzard and honey buzzard nestlings had significantly lower alpha-tocopherol plasma concentrations than nestlings of the other species (both P<0.001). Adult male ospreys and white-tailed sea eagles had significantly higher alpha-tocopherol concentrations compared to adult females (both P<0.005). Adult ospreys and northern goshawks had significantly higher alpha-tocopherol plasma concentrations compared to their nestlings (both P<0.001). In adult female northern goshawks, plasma concentrations of alpha-tocopherol increased significantly before egg laying (P<0.001). These results demonstrate alpha-tocopherol plasma concentrations in birds of prey to be species specific and influenced by age and reproductive status.},
  language  = {en}
}
@article{MuellerRailaAltenkampetal.2012,
  author    = {Mueller, K. and Raila, Jens and Altenkamp, Rainer and Schmidt, D. and Dietrich, R. and Hurtienne, Andrea and Wink, M. and Krone, O. and Brunnberg, Leo and Schweigert, Florian J.},
  title     = {Concentrations of retinol, 3,4-didehydroretinol, and retinyl esters in plasma of free-ranging birds of prey},
  series = {Journal of animal physiology and animal nutrition},
  volume    = {96},
  journal   = {Journal of animal physiology and animal nutrition},
  number    = {6},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0931-2439},
  doi       = {10.1111/j.1439-0396.2011.01219.x},
  pages     = {1044 -- 1053},
  year      = {2012},
  abstract  = {This study investigated vitamin A compounds in the plasma of healthy free-ranging Central European raptors with different feeding strategies. Plasma samples of nestlings of white-tailed sea eagle [white-tailed sea eagle (WTSE), Haliaeetus albicilla) (n = 32), osprey (Pandion haliaetus) (n = 39), northern goshawk (Accipiter gentilis) (n = 25), common buzzard (Buteo buteo) (n = 31), and honey buzzard (Pernis apivorus) (n = 18) and adults of WTSE (n = 10), osprey (n = 31), and northern goshawk (n = 45) were investigated with reversed-phase-high-performance liquid chromatography (RP-HPLC). In WTSE, northern goshawks and common buzzards retinol were the main plasma component of vitamin A, whilst in ospreys and honey buzzards, 3,4-didehydroretinol predominated. The median of the retinol plasma concentration in the nestlings group ranged from 0.12 to 3.80 mu M and in the adult group from 0.15 to 6.13 mu M. Median plasma concentrations of 3,4-didehydroretinol in nestlings ranged from 0.06 to 3.55 mu M. In adults, northern goshawks had the lowest plasma concentration of 3,4-didehydroretinol followed by WTSE and ospreys. The plasma of all investigated species contained retinyl esters (palmitate, oleate, and stearate). The results show considerable species-specific differences in the vitamin A plasma concentrations that might be caused by different nutrition strategies.},
  language  = {en}
}
@article{LongardtSchmiedchenRailaetal.2014,
  author    = {Longardt, Ann Carolin and Schmiedchen, B. and Raila, Jens and Schweigert, Florian J. and Obladen, M. and Buehrer, Christoph and Loui, A.},
  title     = {Characterization of the vitamin A transport in preterm infants after repeated high-dose vitamin A injections},
  series = {European journal of clinical nutrition},
  volume    = {68},
  journal   = {European journal of clinical nutrition},
  number    = {12},
  publisher = {Nature Publ. Group},
  address   = {London},
  issn      = {0954-3007},
  doi       = {10.1038/ejcn.2014.202},
  pages     = {1300 -- 1304},
  year      = {2014},
  abstract  = {BACKGROUND/OBJECTIVES: Preterm infants have low vitamin A stores at birth, and parenteral administration of high-dose vitamin A reduces pulmonary morbidity. The aim was to characterize vitamin A transport and status. SUBJECTS/METHODS: Prospective study of 69 preterm infants (median birth weight 995 g, gestational age 28 weeks), in which 51 received 5000 IU vitamin A three times per week intramuscular (i.m.) for 4 weeks and 18 infants without i.m. vitamin A served as controls. Serum retinol, retinyl palmitate, total retinol-binding protein 4 (RBP4), retinol-unbound RBP4 (apo-RBP4) and transthyretin concentrations were determined at days 3 (D3) and 28 (D28) of life. RESULTS: D3 retinol concentrations were low for the entire group (382 (285/531) nmol/l; median/interquartile range) and unrelated to gestational age. D28 retinol was unchanged in controls (382 (280/471) nmol/l), but increased in the vitamin A group (596 (480/825) nmol/l; P < 0.001). A similar pattern was observed for RBP4. The calculated retinol-to-RBP4 ratio rose in vitamin A infants (D3: 0.81 (0.57/0.94), D28: 0.98 (0.77/1.26); P < 0.01) but not in controls. In the vitamin A group, the retinol-to-RBP4 ratio was 41 in 15\% of all infants on D3 and in 45\% of infants on D28, but was <= 1 in all, but one, controls on D28. CONCLUSIONS: In preterm infants receiving a 4-week course of high-dose i. m. vitamin A, serum retinol concentrations increased by 55\%, with molar concentrations of retinol exceeding those of RBP4 in 45\% of the infants suggesting transport mechanisms other than RBP4.},
  language  = {en}
}
@inproceedings{KhalilIsalmRailaetal.2011,
  author    = {Khalil, Mahomound and Isalm, K. Shaiful and Raila, Jens and Schenk, R. and Rawel, Harshadrai Manilal and Schweigert, Florian J.},
  title     = {Content of lutein and lutein ester in tagetes and improvement of their stability},
  series = {Annals of nutrition \& metabolism : journal of nutrition, metabolic diseases and dietetics ; an official journal of International Union of Nutritional Sciences (IUNS)},
  volume    = {58},
  booktitle = {Annals of nutrition \& metabolism : journal of nutrition, metabolic diseases and dietetics ; an official journal of International Union of Nutritional Sciences (IUNS)},
  number    = {3},
  publisher = {Karger},
  address   = {Basel},
  issn      = {0250-6807},
  pages     = {16 -- 16},
  year      = {2011},
  language  = {en}
}
@article{KhalilRailaAlietal.2012,
  author    = {Khalil, Mahmoud and Raila, Jens and Ali, Mostafa and Islam, Khan M. S. and Schenk, Regina and Krause, Jens-Peter and Schweigert, Florian J. and Rawel, Harshadrai Manilal},
  title     = {Stability and bioavailability of lutein ester supplements from Tagetes flower prepared under food processing conditions},
  series = {Journal of functional food},
  volume    = {4},
  journal   = {Journal of functional food},
  number    = {3},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1756-4646},
  doi       = {10.1016/j.jff.2012.03.006},
  pages     = {602 -- 610},
  year      = {2012},
  abstract  = {Tagetes spp. belongs to the Asteraceae family. It is recognized as a major source of lutein ester (lutein esterified with fatty acids such as lauric, myristic and palmitic acids), a natural colorant belonging to the xanthophylls or oxygenated carotenoids. Four species of Tagetes flower (Tagetes tenuifolia, Tagetes erecta, Tagetes patula, and Tagetes lucida) were used to extract lutein and lutein esters with three different methods. The results showed that T. erecta, type "orangeprinz", is the richest source of lutein esters (14.4 +/- 0.234 mg/g) in comparison to other Tagetes spp. No significant differences between extractions of lutein esters with medium-chain triacylglycerols (MCT) oil, orange oil or solvent (hexane/isopropanol) could be observed. MCT oil also improved stability of lutein esters at 100 degrees C for 40 min. Emulsification of MCT oil improved the stability of lutein ester extract against UV light at 365 nm for 72 h. Finally, an emulsion was prepared under food processing conditions, spray dried and its bioavailability investigated in a preliminary human intervention study. The results show a lower resorption, but further data suggest improvements in implementation of such supplements. (c) 2012 Elsevier Ltd. All rights reserved.},
  language  = {en}
}
@article{IslamKhalilMaenneretal.2016,
  author    = {Islam, Khan Shaiful and Khalil, Mahmoud and M{\"a}nner, K. and Raila, Jens and Rawel, Harshadrai Manilal and Zentek, J. and Schweigert, Florian J.},
  title     = {Effect of dietary alpha-tocopherol on the bioavailability of lutein in laying hen},
  series = {Journal of animal physiology and animal nutrition},
  volume    = {100},
  journal   = {Journal of animal physiology and animal nutrition},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0931-2439},
  doi       = {10.1111/jpn.12464},
  pages     = {868 -- 875},
  year      = {2016},
  abstract  = {Lutein and its isomer zeaxanthin have gained considerable interest as possible nutritional ingredient in the prevention of age-related macular degeneration (AMD) in humans. Egg yolk is a rich source of these carotenoids. As an oxidative sensitive component, antioxidants such as -tocopherol (T) might contribute to an improved accumulation in egg yolk. To test this, chickens were fed lutein esters (LE) with and without -tocopherol as an antioxidant. After depletion on a wheat-soya bean-based lutein-poor diet for 21days, laying hens (n=42) were equally divided into three groups and fed the following diets for 21days: control (basal diet), a LE group (40mg LE/kg feed) and LE+T group (40mg LE plus 100mg T/kg feed). Eggs and blood were collected periodically. Carotenoids and -tocopherol in yolk and blood plasma were determined by HPLC. Egg yolk was also analysed for total carotenoids using a one-step spectrophotometric method (iCheck(())). Lutein, zeaxanthin, -tocopherol and total carotenoids in egg yolk were highest after 14days of feeding and decreased slightly afterwards. At the end of the trial, eggs of LE+T group contained higher amount of lutein (13.72), zeaxanthin (0.65), -tocopherol (297.40) and total carotenoids (21.6) compared to the LE group (10.96, 0.55, 205.20 and 18.0mg/kg, respectively, p<0.05). Blood plasma values of LE+T group contain higher lutein (1.3), zeaxanthin (0.06) and tocopherol (20.1) compared to LE group (1.02, 0.04 and 14.90mg/l, respectively, p<0.05). In conclusion, dietary -tocopherol enhances bioavailability of lutein reflecting higher content in egg yolk and blood plasma. Improved bioavailability might be due to increased absorption of lutein in the presence of tocopherol and/or a greater stability of lutein/zeaxanthin due to the presence of -tocopherol as an antioxidant.},
  language  = {en}
}
@article{IslamKhalilMaenneretal.2017,
  author    = {Islam, Khan M. S. and Khalil, Mahmoud Abd Elhamid and Maenner, Klaus and Raila, Jens and Rawel, Harshadrai Manilal and Zentek, J{\"u}rgen and Schweigert, Florian J.},
  title     = {Lutein Specific Relationships among Some Spectrophotometric and Colorimetric Parameters of Chicken Egg Yolk},
  series = {The journal of poultry science},
  volume    = {54},
  journal   = {The journal of poultry science},
  publisher = {Japan Poultry Science Association},
  address   = {Tsukuba},
  issn      = {1346-7395},
  doi       = {10.2141/jpsa.0160065},
  pages     = {271 -- 277},
  year      = {2017},
  abstract  = {Lutein is an essential dietary carotenoid with health benefits and is inter alia responsible for the colouration of egg yolk. The relationship between lutein accumulation and egg yolk colouration was therefore studied in more detail. After feeding a low-luteine diet for 21 days, 14 birds (Lohmann brown hens aged 20 weeks) were fed a diet containing marigold (80 mg lutein/kg feed) and 14 other birds were fed a diet containing oleoresin (45 mg lutein/kg feed) for 21 days; for both groups of birds, this feeding period was followed by withdrawal for 21 days. The Roche Yolk Colour Fan (RYCF) score (0 to 15, where higher values denote greater colour intensity; R-2=0.87; P<0.01) and redness (R-2=0.89; P<0.01) increased with increasing lutein content of egg yolk. Total carotenoid content had a poor relationship with lightness (R-2=0.13; P>0.05) and yellowness (R-2=0.12; P>0.05) of the yolk. It may be concluded that increased lutein is potentially responsible for an increased RYCF score and redness (a*), but decreased yellowness (b*) and lightness (L*), of egg yolk.},
  language  = {en}
}