Search results for "Vitamins"
showing 10 items of 168 documents
Metabolomics of Human Amniotic Fluid and Maternal Plasma during Normal Pregnancy
2016
Metabolic profiles of amniotic fluid and maternal blood are sources of valuable information about fetus development and can be potentially useful in diagnosis of pregnancy disorders. In this study, we applied 1H NMR-based metabolic profiling to track metabolic changes occurring in amniotic fluid (AF) and plasma (PL) of healthy mothers over the course of pregnancy. AF and PL samples were collected in the 2nd (T2) and 3rd (T3) trimester, prolonged pregnancy (PP) until time of delivery (TD). A multivariate data analysis of both biofluids reviled a metabolic switch-like transition between 2nd and 3rd trimester, which was followed by metabolic stabilization throughout the rest of pregnancy proba…
MTHFR 677C → T genotype modulates the effect of a 5-year supplementation with B-vitamins on homocysteine concentration: The SU.FOL.OM3 randomized con…
2018
Aims To study how MTHFR 677C→T genotype modulates the effect of supplementation with B-vitamins on total homocysteine (tHcy) and B-vitamin concentrations. Methods 2381 patients with a personal history of cardiovascular disease were randomly assigned to one of four groups: 1) B-vitamins alone (560 μg of 5-methyl-THF, 3 mg of vitamin B6 and 20 μg of vitamin B12), 2) n-3 fatty acids alone (600 mg of EPA and DHA in a 2:1 ratio), 3) B-vitamins and n-3 fatty acids, and 4) placebo. Participants were followed up for 4.7 years. At baseline and annually thereafter, biological parameters were assessed. Multivariate and linear mixed models were fit to study the interaction between B-vitamins and MTHFR …
Elimination of Vitamin D Signaling Causes Increased Mortality in a Model of Overactivation of the Insulin Receptor: Role of Lipid Metabolism
2022
Vitamin D (VD) deficiency has been associated with cancer and diabetes. Insulin signaling through the insulin receptor (IR) stimulates cellular responses by activating the PI3K/AKT pathway. PTEN is a tumor suppressor and a negative regulator of the pathway. Its absence enhances insulin signaling leading to hypoglycemia, a dangerous complication found after insulin overdose. We analyzed the effect of VD signaling in a model of overactivation of the IR. We generated inducible double KO (DKO) mice for the VD receptor (VDR) and PTEN. DKO mice showed severe hypoglycemia, lower total cholesterol and increased mortality. No macroscopic tumors were detected. Analysis of the glucose metabolism did n…
Effects of oral niacin on endothelial dysfunction in patients with coronary artery disease: Results of the randomized, double-blind, placebo-controll…
2009
High-density-lipoproteins-cholesterol (HDL-C) is invertedly related to the incidence of cardiovascular events. Recent studies suggest that HDL-C directly improves endothelial function. Nicotinic acid (niacin) effectively raises serum HDL-C. We therefore hypothesized that treatment with niacin improves endothelial dysfunction in patients with coronary artery disease (CAD). One hundred seven patients with CAD were randomly assigned to double-blinded treatment for 12 weeks with extended-release (ER)-niacin 1000 mg/day (N) or placebo (C), respectively. Flow-mediated dilation (FMD) of the brachial artery, nitroglycerin-mediated endothelium-independent dilation (NMD) and serum lipid concentration…
A comparative study of the physicochemical properties of iron isomaltoside 1000 (Monofer®), a new intravenous iron preparation and its clinical impli…
2011
Abstract The treatment of iron deficiency anemia with polynuclear iron formulations is an established therapy in patients with chronic kidney disease but also in other disease areas like gastroenterology, cardiology, oncology, pre/post operatively and obstetrics’ and gynecology. Parenteral iron formulations represent colloidal systems in the lower nanometer size range which have traditionally been shown to consist of an iron core surrounded by a carbohydrate shell. In this publication, we for the first time describe the novel matrix structure of iron isomaltoside 1000 which differs from the traditional picture of an iron core surrounded by a carbohydrate. Despite some structural similaritie…
Comparison of quantum dot-binding protein tags: Affinity determination by ultracentrifugation and FRET
2013
Abstract Background Hybrid complexes of proteins and colloidal semiconductor nanocrystals (quantum dots, QDs) are of increasing interest in various fields of biochemistry and biomedicine, for instance for biolabeling or drug transport. The usefulness of protein–QD complexes for such applications is dependent on the binding specificity and strength of the components. Often the binding properties of these components are difficult and time consuming to assess. Methods In this work we characterized the interaction between recombinant light harvesting chlorophyll a / b complex (LHCII) and CdTe/CdSe/ZnS QDs by using ultracentrifugation and fluorescence resonance energy transfer (FRET) assay exper…
Preparation of Native and Recombinant Light-Harvesting Chlorophyll-<I>a/b </I>Complex
2004
Procedures to isolate native light-harvesting chlorophyll-a/b complex (LHCIIb) and to reconstitute recombinant LHCIIb are described. Separation of trimeric from monomeric forms and free pigment by sucrose density-gradient ultracentrifugation can be applied to both native and reconstituted complexes. The preparations are characterized by their pigment composition, protein pattern, and spectral properties.
Light-harvesting chlorophyll a/b-binding protein stably inserts into etioplast membranes supplemented with Zn-pheophytin a/b.
1997
Light-harvesting chlorophyll a/b-binding protein, LHCP, or its precursor, pLHCP, cannot be stably inserted into barley etioplast membranes in vitro. However, when these etioplast membranes are supplemented with the chlorophyll analogs Zn-pheophytin a/b, synthesized in situ from Zn-pheophorbide a/b and digeranyl pyrophosphate, pLHCP is inserted into a protease-resistant state. This proves that chlorophyll is the only component lacking in etioplast membranes that is necessary for stable LHCP insertion. Synthesis of Zn-pheophytin b alone promotes insertion of LHCP in vitro into a protease-resistant state, whereas synthesis of Zn-pheophytin a alone does not. Insertion of pLHCP into etioplast me…
Determination of relative chlorophyll binding affinities in the major light-harvesting chlorophyll a/b complex.
2002
The major light-harvesting complex (LHCIIb) of photosystem II can be reconstituted in vitro from its recombinant apoprotein in the presence of a mixture of carotenoids and chlorophylls a and b. By varying the chlorophyll a/b ratio in the reconstitution mixture, the relative amounts of chlorophyll a and chlorophyll b bound to LHCIIb can be changed. We have analyzed the chlorophyll stoichiometry in recombinant wild type and mutant LHCIIb reconstituted at different chlorophyll a/b ratios in order to assess relative affinities of the chlorophyll-binding sites. This approach reveals five sites that exclusively bind chlorophyll b. Another site exhibits a slight preference of chlorophyll b over ch…
Consecutive binding of chlorophylls a and b during the assembly in vitro of light-harvesting chlorophyll-a/b protein (LHCIIb).
2006
The apoprotein of the major light-harvesting chlorophyll a/b complex (LHCIIb) is post-translationally imported into the chloroplast, where membrane insertion, protein folding, and pigment binding take place. The sequence and molecular mechanism of the latter steps is largely unknown. The complex spontaneously self-organises in vitro to form structurally authentic LHCIIb upon reconstituting the unfolded recombinant protein with the pigments chlorophyll a, b, and carotenoids in detergent micelles. Former measurements of LHCIIb assembly had revealed two apparent kinetic phases, a faster one (tau1) in the range of 10 s to 1 min, and a slower one (tau2) in the range of several min. To unravel th…