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https://www.readbyqxmd.com/read/28223907/comparative-bioavailability-and-utilization-of-particular-forms-of-b12-supplements-with-potential-to-mitigate-b12-related-genetic-polymorphisms
#1
REVIEW
Cristiana Paul, David M Brady
CONTEXT: Three natural forms of vitamin B12 are commercially available: methylcobalamin (MeCbl), adenosylcobalamin (AdCbl), and hydroxycobalamin (OHCbl), all of which have been shown in clinical studies to improve vitamin B12 status. They are bioidentical to the B12 forms occurring in human physiology and animal foods. In contrast, cyanocobalamin (CNCbl), a synthetic B12 compound used for food fortification and in some supplements, occurs only in trace amounts in human tissues as a result of cyanide intake from smoking or other sources...
February 2017: Integrative Medicine
https://www.readbyqxmd.com/read/28218226/manic-depressive-psychosis-as-the-initial-symptom-in-adult-siblings-with-late-onset-combined-methylmalonic-aciduria-and-homocystinemia-cobalamin-c-type
#2
Li-Yong Wu, Hong An, Jia Liu, Jie-Ying Li, Yue Han, Ai-Hong Zhou, Fen Wang, Jian-Ping Jia
No abstract text is available yet for this article.
2017: Chinese Medical Journal
https://www.readbyqxmd.com/read/28210839/thrombotic-microangiopathy-caused-by-methionine-synthase-deficiency-diagnosis-and-treatment-pitfalls
#3
Maria Helena Vaisbich, Andressa Braga, Maria Gabrielle, Clarissa Bueno, Flávia Piazzon, Fernando Kok
BACKGROUND: Inborn errors of cobalamin (Cbl) metabolism form a large group of rare diseases. One of these, Cbl deficiency type C (CblC), is a well-known cause of thrombotic microangiopathy (TMA), especially in infants. However, there has only been a single published case of TMA associated to Cbl deficiency type G (CblG), also known as methionine synthase deficiency (MSD). CASE DIAGNOSIS/TREATMENT: A 21-month-old boy presented with pallor and oral ulcers during episodes of upper respiratory infection (URI)...
February 16, 2017: Pediatric Nephrology: Journal of the International Pediatric Nephrology Association
https://www.readbyqxmd.com/read/28193074/cobalamin-concentrations-in-fetal-liver-show-gender-differences-a-result-from-using-a-high-pressure-liquid-chromatography-inductively-coupled-plasma-mass-spectrometry-as-an-ultratrace-cobalt-speciation-method
#4
Janine Bosle, Sven Goetz, Andrea Raab, Eva M Krupp, Kirk G Scheckel, Enzo Lombi, Andrew A Meharg, Paul A Fowler, Jörg Feldmann
Maternal diet and lifestyle choices may affect placental transfer of cobalamin (Cbl) to the fetus. Fetal liver concentration of Cbl reflects nutritional status with regards to vitamin B12, but at these low concentration current Cbl measurement methods lack robustness. An analytical method based on enzymatic extraction with subsequent reversed-phase-high-pressure liquid chromatography (RP-HPLC) separation and parallel ICPMS and electrospray ionization (ESI)-Orbitrap-MS to determine specifically Cbl species in liver samples of only 10-50 mg was developed using 14 pig livers...
December 20, 2016: Analytical Chemistry
https://www.readbyqxmd.com/read/28191552/a-common-mechanism-for-coenzyme-cobalamin-dependent-reductive-dehalogenases
#5
Linus O Johannissen, David Leys, Sam Hay
Distinct mechanisms have been proposed for the biological dehalogenation catalyzed by cobalamin-dependent enzymes, with two recent crystallographic studies suggesting different mechanisms based on the observed interaction between the organohalide substrate and cobalamin. In one case, involving an aromatic dibromide substrate in NpRdhA, a novel Co(II)-Br interaction was observed using EPR, suggesting a mechanism involving a [CoXR] adduct. However, in the case of trichloroethylene in PceA, a significantly longer Co-Cl distance was observed in X-ray crystal structures, suggesting a dissociative electron transfer mechanism...
February 13, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28188205/metagenomic-and-metatranscriptomic-analyses-reveal-structure-and-dynamics-of-a-dechlorinating-community-containing-dehalococcoides-mccartyi-and-corrinoid-providing-microorganisms-under-cobalamin-limited-condition
#6
Yujie Men, Ke Yu, Jacob Bælum, Ying Gao, Julien Tremblay, Emmanuel Prestat, Ben Stenuit, Susannah G Tringe, Janet Jansson, Tong Zhang, Lisa Alvarez-Cohen
The aim of this study is to obtain a systems level understanding of the interactions between Dehalococcoides and corrinoid-supplying microorganisms by analyzing community structures and functional compositions, activities and dynamics in trichloroethene (TCE) - dechlorinating enrichments. Metagenomes and metatranscriptomes of the dechlorinating enrichments with and without exogenous cobalamin were compared. Seven putative draft genomes were binned from the metagenomes. At an early stage (2 d), more transcripts of genes in the Veillonellaceae bin-genome were detected in the metatranscriptome of the enrichment with exogenous cobalamin compared to the one without cobalamin addition...
February 10, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/28186498/underlying-mechanisms-for-syntrophic-metabolism-of-essential-enzyme-cofactors-in-microbial-communities
#7
Margaret F Romine, Dmitry A Rodionov, Yukari Maezato, Andrei L Osterman, William C Nelson
Many microorganisms are unable to synthesize essential B vitamin-related enzyme cofactors de novo. The underlying mechanisms by which such microbes survive in multi-species communities are largely unknown. We previously reported the near-complete genome sequence of two ~18-member unicyanobacterial microbial consortia that maintain stable membership on defined medium lacking vitamins. Here we have used genome analysis and growth studies on isolates derived from the consortia to reconstruct pathways for biogenesis of eight essential cofactors and predict cofactor usage and precursor exchange in these communities...
February 10, 2017: ISME Journal
https://www.readbyqxmd.com/read/28183371/regular-breakfast-consumption-is-associated-with-higher-blood-vitamin-status-in-adolescents-the-helena-healthy-lifestyle-in-europe-by-nutrition-in-adolescence-study
#8
Juan Mielgo-Ayuso, Jara Valtueña, Magdalena Cuenca-García, Fréderic Gottrand, Christina Breidenassel, Marika Ferrari, Yannis Manios, Stefaan De Henauw, Kurt Widhalm, Anthony Kafatos, Mathilde Kersting, Inge Huybrechts, Luis A Moreno, Marcela González-Gross
OBJECTIVE: The present study aimed to examine the association between different breakfast consumption patterns and vitamin intakes and blood vitamin concentrations in European adolescents. DESIGN: Breakfast consumption was assessed by a questionnaire. Vitamin intake was calculated from two 24 h recalls. Blood vitamin and total homocysteine (tHcy) concentrations were analysed from fasting blood samples. SETTING: The European Commission-funded HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study...
February 10, 2017: Public Health Nutrition
https://www.readbyqxmd.com/read/28167430/vitamin-b12-in-the-spotlight-again
#9
REVIEW
Jennifer Bridwell-Rabb, Catherine L Drennan
The ability of cobalamin to coordinate different upper axial ligands gives rise to a diversity of reactivity. Traditionally, adenosylcobalamin is associated with radical-based rearrangements, and methylcobalamin with methyl cation transfers. Recently, however, a new role for adenosylcobalamin has been discovered as a light sensor, and a methylcobalamin-dependent enzyme has been identified that is suggested to transfer a methyl anion. Additionally, recent studies have provided a wealth of new information about a third class of cobalamin-dependent enzymes that do not appear to use an upper ligand...
February 3, 2017: Current Opinion in Chemical Biology
https://www.readbyqxmd.com/read/28167213/metagenomics-approach-to-the-study-of-the-gut-microbiome-structure-and-function-in-zebrafish-danio-rerio-fed-with-gluten-formulated-diet
#10
Hyunmin Koo, Joseph A Hakim, Mickie L Powell, Ranjit Kumar, Peter G Eipers, Casey D Morrow, Michael Crowley, Elliot J Lefkowitz, Stephen A Watts, Asim K Bej
In this study, we report the gut microbial composition and predictive functional profiles of zebrafish, Danio rerio, fed with a control formulated diet (CFD), and a gluten formulated diet (GFD) using a metagenomics approach and bioinformatics tools. The microbial communities of the GFD-fed D. rerio displayed heightened abundances of Legionellales, Rhizobiaceae, and Rhodobacter, as compared to the CFD-fed counterparts. Predicted metagenomics of microbial communities (PICRUSt) in GFD-fed D. rerio showed KEGG functional categories corresponding to bile secretion, secondary bile acid biosynthesis, and the metabolism of glycine, serine, and threonine...
February 3, 2017: Journal of Microbiological Methods
https://www.readbyqxmd.com/read/28165219/redox-potentials-of-cobalt-corrinoids-with-axial-ligands-correlate-with-heterolytic-co-c-bond-dissociation-energies
#11
Yoshitsugu Morita, Koji Oohora, Akiyoshi Sawada, Takashi Kamachi, Kazunari Yoshizawa, Takashi Hayashi
We investigate the correlations between the redox potentials of nonalkylated cobalt corrinoids and the Co-C bond dissociation energies (BDEs) of the methylated species with an aqua or histidine axial ligand. A set of cobalt corrinoids, cobalamin, and its model systems, which include new version of myoglobin reconstituted with cobalt didehydrocorrin, are investigated. The Co(III)/Co(II) and Co(II)/Co(I) redox potentials of myoglobin reconstituted with cobalt tetradehydrocorrin and didehydrocorrin and the bare cofactors were determined...
February 20, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28164751/pernicious-anemia-fundamental-and-practical-aspects-in-diagnosis
#12
Aung Myint Tun, Kyaw Zin Thein, Zin War Myint, Thein Hlaing Oo
Pernicious anemia (PA), the most common cause of cobalamin deficiency anemia worldwide, is an autoimmune disease of multifactorial etiologies involving complex environmental and immunological factors. Although it was first reported by Addison in 1849 with subsequent advances in understanding of pathogenesis and molecular biology, diagnosis of pernicious anemia is still challenging for clinicians because of its complexity and diverse clinical presentations. Herein, we provide an overview of PA, mainly focusing on its scientific and practical aspects in diagnosis...
February 3, 2017: Cardiovascular & Hematological Agents in Medicinal Chemistry
https://www.readbyqxmd.com/read/28161887/evaluation-of-vitamin-and-trace-element-requirements-after-sleeve-gastrectomy-at-long-term
#13
Silvia Pellitero, Eva Martínez, Rocío Puig, Alba Leis, Roxanna Zavala, María Luisa Granada, Cruz Pastor, Pau Moreno, Jordi Tarascó, Manel Puig-Domingo
BACKGROUND: Nutritional deficiencies are common after bariatric surgery, but data are scarce after sleeve gastrectomy (SG) at long term. METHODS: We performed a prospective nutritional status evaluation before and at 2 and 5 years after SG in morbid obese patients receiving mulvitamin and mineral supplementation at a Spanish university hospital. One hundred seventy-six patients (49.3 ± 9.1 years and 46.7 ± 7.4 kg/m(2)) were evaluated; 51 of them were followed during 5 years...
February 4, 2017: Obesity Surgery
https://www.readbyqxmd.com/read/28151490/efficacy-of-early-treatment-in-patients-with-cobalamin-c-disease-identified-by-newborn-screening-a-16-year-experience
#14
Rebecca C Ahrens-Nicklas, Ashley M Whitaker, Paige Kaplan, Sanmati Cuddapah, Jessica Burfield, Jennifer Blair, Ligia Brochi, Marc Yudkoff, Can Ficicioglu
PURPOSE: Despite implementation of newborn screening (NBS), outcomes in cobalamin C disease (cblC) remain poor. Therapy with hydroxycobalamin and betaine is widely used, but dietary recommendations vary among metabolic centers. We present a longitudinal analysis of the relationship between metabolic control, diet, and outcomes in a cohort of cblC patients. METHODS: We completed a retrospective analysis of 12 patients with cblC referred for abnormal NBS results and followed in our center between 1999 and 2015...
February 2, 2017: Genetics in Medicine: Official Journal of the American College of Medical Genetics
https://www.readbyqxmd.com/read/28137297/microbial-production-of-vitamin-b12-a-review-and-future-perspectives
#15
REVIEW
Huan Fang, Jie Kang, Dawei Zhang
Vitamin B12 is an essential vitamin that is widely used in medical and food industries. Vitamin B12 biosynthesis is confined to few bacteria and archaea, and as such its production relies on microbial fermentation. Rational strain engineering is dependent on efficient genetic tools and a detailed knowledge of metabolic pathways, regulation of which can be applied to improve product yield. Recent advances in synthetic biology and metabolic engineering have been used to efficiently construct many microbial chemical factories...
January 30, 2017: Microbial Cell Factories
https://www.readbyqxmd.com/read/28135329/hepatic-effects-of-pharmacological-doses-of-hydroxy-cobalamin-c-lactam-in-mice
#16
Patrizia Haegler, David Grünig, Benjamin Berger, Luigi Terracciano, Stephan Krähenbühl, Jamal Bouitbir
The vitamin B12 analog hydroxy-cobalamin[c-lactam] (HCCL) impairs hepatic mitochondrial protein synthesis and function of the electron transport chain in rats. We aimed to establish an in vivo model for mitochondrial dysfunction in mice, which could be used to investigate hepatotoxicity of mitochondrial toxicants. In a first step, we performed a dose-finding study in mice treated with HCCL 0.4 mg/kg and 4 mg/kg i.p. for two to four weeks. The plasma methylmalonate concentration was strongly increased at 4 mg/kg starting at three weeks of treatment...
2017: PloS One
https://www.readbyqxmd.com/read/28135083/polarized-xanes-monitors-femtosecond-structural-evolution-of-photoexcited-vitamin-b12
#17
Nicholas A Miller, Aniruddha Deb, Roberto Alonso-Mori, Brady D Garabato, James M Glownia, Laura M Kiefer, Jake Koralek, Marcin Sikorski, Kenneth G Spears, Theodore E Wiley, Diling Zhu, Pawel M Kozlowski, Kevin J Kubarych, James E Penner-Hahn, Roseanne J Sension
Ultrafast, polarization-selective time-resolved X-ray absorption near-edge structure (XANES) was used to characterize the photochemistry of vitamin B12, cyanocobalamin (CNCbl), in solution. Cobalamins are important biological cofactors involved in methyl transfer, radical rearrangement, and light-activated gene regulation, while also holding promise as light-activated agents for spatiotemporal controlled delivery of therapeutics. We introduce polarized femtosecond XANES, combined with UV-visible spectroscopy, to reveal sequential structural evolution of CNCbl in the excited electronic state...
January 30, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28128683/oral-cobalamin-supplementation-in-cats-with-hypocobalaminaemia-a-retrospective-study
#18
Linda Toresson, Joerg M Steiner, Gunilla Olmedal, MajBritt Larsen, Jan S Suchodolski, Thomas Spillmann
Objectives The objective was to evaluate whether oral cobalamin supplementation can restore normocobal-aminaemia in cats with hypocobalaminaemia and clinical signs of gastrointestinal disease. Methods This was a retrospective study based on a computerised database search for client-owned cats treated at Evidensia Specialist Animal Hospital, Helsingborg, Sweden, during the period December 2013 to August 2016. Inclusion criteria were cats with clinical signs of chronic enteropathy, an initial serum cobalamin concentration ⩽250 pmol/l (reference interval 214-738 pmol/l) and oral treatment with cobalamin tablets...
January 1, 2017: Journal of Feline Medicine and Surgery
https://www.readbyqxmd.com/read/28128549/identification-of-a-novel-epoxyqueuosine-reductase-family-by-comparative-genomics
#19
Rémi Zallot, Robert Ross, Wei-Hung Chen, Steven D Bruner, Patrick A Limbach, Valerie De Crecy-Lagard
The reduction of epoxyqueuosine (oQ) is the last step in the synthesis of the tRNA modification Queuosine (Q). While the epoxyqueuosine reductase (EC 1.17.99.6) enzymatic activity was first described thirty years ago, the encoding gene queG was only identified in Escherichia coli in 2011. Interestingly, queG is absent from a large number of sequenced genomes that harbor Q synthesis or salvage genes, suggesting the existence of an alternative epoxyqueuosine reductase in these organisms. By analyzing phylogenetic distributions, physical gene clustering and fusions, members of the Domain of Unknown Function 208 (DUF208) family were predicted to encode for an alternative epoxyqueuosine reductase...
January 27, 2017: ACS Chemical Biology
https://www.readbyqxmd.com/read/28128319/conformational-change-of-a-tryptophan-residue-in-btuf-facilitates-binding-and-transport-of-cobinamide-by-the-vitamin-b12-transporter-btucd-f
#20
S A Mireku, M Ruetz, T Zhou, V M Korkhov, B Kräutler, K P Locher
BtuCD-F is an ABC transporter that mediates cobalamin uptake into Escherichia coli. Early in vivo data suggested that BtuCD-F might also be involved in the uptake of cobinamide, a cobalamin precursor. However, neither was it demonstrated that BtuCD-F indeed transports cobinamide, nor was the structural basis of its recognition known. We synthesized radiolabeled cyano-cobinamide and demonstrated BtuCD-catalyzed in vitro transport, which was ATP- and BtuF-dependent. The crystal structure of cobinamide-bound BtuF revealed a conformational change of a tryptophan residue (W66) in the substrate binding cleft compared to the structure of cobalamin-bound BtuF...
January 27, 2017: Scientific Reports
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