Synthesis and crystal structure of Pb(Bipy)2B12H12

International Nuclear Information System (INIS)

Lagun, V.L.; Orlova, A.M.; Katser, S.B.; Solntsev, K.A.; Kuznetsov, N.T.

1994-01-01

Lead complex with B 12 H 12 2- anion and 2,2' bipyridine-lead(2) dodecahydro-closo-dodecaborate di(2,2' bipyridine) is synthesized and characterized by IF, UV and NMR spectrography methods. According to roentgen-structural analysis the crystals belong to monoclinic syngony, sp.gr. C2/m,a=17.872(4), b=18.672(5), c=9.228(7)A, β=109.11(4), V=2910(2)A 3 , Z=4. The structure consists of Pb 2 (Bipy) 4 (B 12 H 12 ) 2 dimeric units. The Pb-B distances are within the limits of 3.313-3.514A. 11 refs.; 2 figs.; 2 tabs

Synthesis and crystal structure of Pb(Bipy)(DMFA)B12H12

International Nuclear Information System (INIS)

Lagun, V.L.; Solntsev, K.A.; Katser, S.B.; Orlova, A.M.; Kuznetsov, N.T.

1994-01-01

Lead complex with B 12 H 12 2- anion and neutral ligands -2,2' -bipyridine (Bipy) and dimethylformamide (DMFA) has been prepared by Pb(Bipy) B 12 H 12 recrystallization from mixed solvent DMFA - benzene (1:1). The complex prepared has been studied by the methods of IR spectroscopy, element and X-ray diffraction analyses. Parameters of monoclinic cell are as follows: 1 = 9.583(2), b = 16.958 (4), c = 18.685 (3) A; β = 105.65 (2), V = 2924 (1) A 3 , Z =4; sp.gr. P2 1 /c. The structure consists of dimer units. Pb-B distance is within 3.23-3.71 (3) A. 5 refs.; 2 figs.; 2 tabs

Degradation of vitamin B12 in dietary supplements.

Science.gov (United States)

Yamada, Keiko; Shimodaira, Michiko; Chida, Seiko; Yamada, Noriko; Matsushima, Norio; Fukuda, Morimichi; Yamada, Shoji

2008-01-01

Beverages and solid dietary supplements rich in various added vitamins and minerals have recently become available. It seems reasonable to consider that the intake of these foods is convenient for easy ingestion of nutrients, but problems caused by blending different nutrients in high concentrations have arisen. We focused on vitamin B12 (B12) among vitamins and determined the B12 contents of beverages and solid dietary supplements purchased from a retail shop. The B12 contents of three of five beverages were less than stated on the labels. On the other hand, certain beverages unexpectedly contained much more B12 than stated on the labels. In these beverages the amount of B12 decreased rapidly with time, whereas B12 content was lower than stated on the label in only one of four solid dietary supplements. The content of B12 was affected by storage time, light exposure, temperature and vitamin C. From experimental analysis with a competitive binding assay method employing a ACS Chemiluminescent B12 kit, examining differential binding by intrinsic factors and spectral analysis of B12, it was determined that some of the B12 might have been converted into B12 analogues or small degradation products by multinutrient interaction during storage.

21 CFR 184.1945 - Vitamin B12.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Vitamin B12. 184.1945 Section 184.1945 Food and... Substances Affirmed as GRAS § 184.1945 Vitamin B12. (a) Vitamin B12, also known as cyanocobalamin (C63H88Co... is used in food at levels not to exceed current good manufacturing practice. Vitamin B12 also may be...

Absorption of vitamin B12 and effect of pancreatic juice on gastric vitamin B12 binder in the dog

International Nuclear Information System (INIS)

Kasaki, Yukio

1977-01-01

The effect of pancreatic juice on vitamin B 12 absorption was studied in dogs. It was found that dog gastric juice as well as pancreatic juice contain vitamin B 12 binding proteins which differ in the elution pattern on DEAE-cellulose columns, the former being eluted at much lower sodium chloride concentrations. When radio-active vitamin B 12 was fed or instilled in the proximal bowel and vitamin B 12 recovered at different bowel levels, it was found that vitamin B 12 -protein complex behaved like gastric juice binder in the proximal bowel and like pancreatic binder in the distal. In vitro digestion of gastric binder with pancreatic juice altered vitamin B 12 -protein complex in such a way that elution pattern became similar to that of pancreatic juice. It was also shown that the change was not due to transfer of vitamin B 12 from gastric binder to pancreatic binder. Trypsin digestion had similar effect on gastric binder, and Sephadex G-200 gelfiltration demonstrated reduction in the molecular size. In the doz, vitamin B 12 first bound to gastric binder undergoes chemical changes in the bowel and becomes a readily absorbable form in the distal bowel. (auth.)

Dietary Sources of Vitamin B-12 and Their Association with Vitamin B-12 Status Markers in Healthy Older Adults in the B-PROOF Study

Directory of Open Access Journals (Sweden)

Elske M. Brouwer-Brolsma

2015-09-01

Full Text Available Low vitamin B-12 concentrations are frequently observed among older adults. Malabsorption is hypothesized to be an important cause of vitamin B-12 inadequacy, but serum vitamin B-12 may also be differently affected by vitamin B-12 intake depending on food source. We examined associations between dietary sources of vitamin B-12 (meat, fish and shellfish, eggs, dairy and serum vitamin B-12, using cross-sectional data of 600 Dutch community-dwelling adults (≥65 years. Dietary intake was assessed with a validated food frequency questionnaire. Vitamin B-12 concentrations were measured in serum. Associations were studied over tertiles of vitamin B-12 intake using P for trend, by calculating prevalence ratios (PRs, and splines. Whereas men had significantly higher vitamin B-12 intakes than women (median (25th–75th percentile: 4.18 (3.29–5.38 versus 3.47 (2.64–4.40 μg/day, serum vitamin B-12 did not differ between the two sexes (mean ± standard deviation (SD: 275 ± 104 pmol/L versus 290 ± 113 pmol/L. Higher intakes of dairy, meat, and fish and shellfish were significantly associated with higher serum vitamin B-12 concentrations, where meat and dairy—predominantly milk were the most potent sources. Egg intake did not significantly contribute to higher serum vitamin B-12 concentrations. Thus, dairy and meat were the most important contributors to serum vitamin B-12, followed by fish and shellfish.

The EGG 57-CO B-12 absorption test, in the evaluation of patients with low serum B-12

International Nuclear Information System (INIS)

Sinow, R.M.; Carmel, R.; Siegel, M.E.

1985-01-01

The Schilling Test (ST) is the standard test for diagnosing vitamin B-12 malabsorption (MA). However, patients with subtle gastric dysfunction may have normal ST, but impaired absorption of B-12 given with food. The authors have adapted an Egg B-12 Absorption Test (EBAT) in which 57-Co cyanocobalamin (57-Co B-12) is mixed with scrambled egg to evaluate this phenomenon in patients with low serum B-12, normal ST and possible subtle MA. Lyophilized egg yolk is reconstituted and mixed with 57-Co- B-12 of equal dose to that of ST. The authors studied 46 individuals: 13 controls, 5 patients with known pernicious anemia (PA), in addition to 28 patients with low serum B-12 levels and normal ST. ST/EBAT ratios were calculated. Twenty-eight test patients excreted 13.3% on ST and 3.5% on EBAT. Mean ST/EBAT ratio was 8.2 (1.4-35.9). Five had EBAT results in the PA range (<1%) and ST/EBAT ratios (14.4-35.9) that were significantly elevated. This group is also evaluated with pepsinogen I/II ratios, gastric analysis, deoxyuridine suppression tests, anti intrinsic factor, and antiparietal cell antibodies. The authors' results indicate that the EBAT can differentiate between PA and non PA patients, and that some patients with low serum B-12 levels and normal ST may, in fact, have subtle MA. The EBAT, combined with ST/EBAT ratio, may provide a means for identifying this group of patients

Vitamin B-12 supplementation during pregnancy and early lactation increases maternal, breast milk, and infant measures of vitamin B-12 status.

Science.gov (United States)

Duggan, Christopher; Srinivasan, Krishnamachari; Thomas, Tinku; Samuel, Tinu; Rajendran, Ramya; Muthayya, Sumithra; Finkelstein, Julia L; Lukose, Ammu; Fawzi, Wafaie; Allen, Lindsay H; Bosch, Ronald J; Kurpad, Anura V

2014-05-01

Pregnant women in resource-poor areas are at risk of multiple micronutrient deficiencies, and indicators of low vitamin B-12 status have been associated with adverse pregnancy outcomes, including anemia, low birth weight, and intrauterine growth retardation. To evaluate whether daily oral vitamin B-12 supplementation during pregnancy increases maternal and infant measures of vitamin B-12 status, we performed a randomized, placebo-controlled clinical trial. Pregnant women vitamin B-12 (50 μg) or placebo through 6 wk postpartum. All women were administered iron and folic acid supplements throughout pregnancy. One hundred eighty-three women were randomly assigned to receive vitamin B-12 and 183 to receive placebo. Compared with placebo recipients, vitamin B-12-supplemented women had significantly higher plasma vitamin B-12 concentrations at both the second (median vitamin B-12 concentration: 216 vs. 111 pmol/L, P vitamin B-12 concentration was 136 pmol/L in vitamin B-12-supplemented women vs. 87 pmol/L in the placebo group (P vitamin B-12-supplemented women, the incidence of delivering an infant with intrauterine growth retardation was 33 of 131 (25%) vs. 43 of 125 (34%) in those administered placebo (P = 0.11). In a subset of infants tested at 6 wk of age, median plasma vitamin B-12 concentration was 199 pmol/L in those born to supplemented women vs. 139 pmol/L in the placebo group (P = 0.01). Infant plasma methylmalonic acid and homocysteine concentrations were significantly lower in the vitamin B-12 group as well. Oral supplementation of urban Indian women with vitamin B-12 throughout pregnancy and early lactation significantly increases vitamin B-12 status of mothers and infants. It is important to determine whether there are correlations between these findings and neurologic and metabolic functions. This trial was registered at clinicaltrials.gov as NCT00641862.

21 CFR 582.5945 - Vitamin B12.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Vitamin B12. 582.5945 Section 582.5945 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5945 Vitamin B12. (a) Product. Vitamin B12. (b) Conditions of use. This substance is...

7 CFR 15b.12 - Discrimination prohibited.

Science.gov (United States)

2010-01-01

... 7 Agriculture 1 2010-01-01 2010-01-01 false Discrimination prohibited. 15b.12 Section 15b.12... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Employment Practices § 15b.12 Discrimination prohibited. (a... discrimination in employment under any program or activity receiving assistance from this Department. (2) A...

Electron addition to alkyl cobalamins, coenzyme B12 and vitamin B12

International Nuclear Information System (INIS)

Rao, D.N.R.; Symons, M.C.R.

1983-01-01

Exposure of dilute solutions of methyl and ethyl cobalamins and coenzyme B 12 in dilute solutions (D 2 O+CD 3 OD) to 60 Co #betta#-rays at 77 K gave a single broad feature in the free-spin region assigned to electron-capture species with the excess electron largely confined to a π* corrin orbital. On warming above 77 K the methyl derivative gave a novel species with spectral features characteristic of an unpaired electron in the Co(dsub(x 2 -y 2 )) orbital. The other two substrates gave spectra due to Cosup(II)Bsub(12r) both on warming and after photolyses with visible light. The acetyl derivative gave an electron-capture species whose e.s.r. spectrum was characteristic of an electron in the Co(dsub(z 2 )) orbital, which on warming above 77 K changed to the normal Cosup(II)Bsub(12r) spectrum. The cyano derivative (vitamin B 12 ) gave electron addition into the Co(dsub(z 2 )) orbital, as evidenced by the large hyperfine coupling to 13 C from 13 CN ligands. On annealing, cyanide ions were lost irreversibly, Bsub(12r) being detected by e.s.r. spectroscopy. In contrast, the dicyano derivative on electron addition at 77 K gave a species containing only one 13 CN ligand. Hence in this case one CN - ligand was lost at 77 K, with no return of the dimethylbenzimidazole ligand. These results are discussed in terms of a new mechanism for electron-addition to alkyl cobalamins. (author)

Vitamin B12 absorption from eggs.

Science.gov (United States)

Doscherholmen, A; McMahon, J; Ripley, D

1975-09-01

The assimilation of 57Co B12 from in vivo labeled eggs was much inferior to that of a comparable amount of crystalline 57Co B12. Furthermore, the absorption varied with the form in which the eggs were served. Judged by the urinary excretion test and the plasma absorption of radioactivity the average absorption from boiled and fried eggs was more than twice that from scrambled whole eggs, but less than half that absorbed from crystalline 57Co B12.

Psoriasis is not associated with IL-12p70/IL-12p40 production and IL12B promoter polymorphism

DEFF Research Database (Denmark)

Litjens, Nicolle H R; van der Plas, Mariena J A; Ravensbergen, Bep

2004-01-01

Psoriasis is a type-1 T cell-mediated, chronic inflammatory disease. Since interleukin (IL)-12p70 promotes the development of type-1 T cells, we investigated whether psoriasis is associated with an increased production of this cyctokine by blood cells. Results revealed that the production of IL-12p....... The frequencies of the various genotypes for the promoter region of the gene encoding IL-12p40 (IL12B) did not differ between psoriasis patients and controls. No association was observed between the various IL12B promoter genotypes and the LPS-stimulated production of IL-12p70 or IL-12p40 by blood cells. Together......, psoriasis is not associated with a promoter polymorphism in the IL12B gene nor with the production of IL-12p70 by LPS-stimulated blood cells....

Atypical B12 Deficiency with Nonresolving Paraesthesia

Directory of Open Access Journals (Sweden)

S. Haider

2013-01-01

Full Text Available Vitamin B12 deficiency can present with various hematological, gastrointestinal and neurological manifestations. We report a case of elderly female who presented with neuropathy and vitamin B12 deficiency where the final work-up revealed polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS. This case suggests that, although POEMS syndrome is a rare entity, it can present with vitamin-B12 deficiency and thus specific work up for early diagnosis of POEMS should be considered in patients with B12 deficiency unresponsive to therapy.

Holo-transcobalamin is an indicator of vitamin B-12 absorption in healthy adults with adequate vitamin B-12 status

DEFF Research Database (Denmark)

von Castel-Roberts, Kristina M; Mørkbak, Anne Louise; Nexo, Ebba

2007-01-01

BACKGROUND: It has been hypothesized that the response of holo-transcobalamin (holo-TC) to oral vitamin B-12 may be used to assess absorption. To develop a reliable clinical absorption test that uses holo-TC, it is necessary to determine the optimal timeline for vitamin B-12 administration...... and postdose assessment. OBJECTIVE: The objective of this study was to assess the magnitude and patterns of change in the postabsorption response of holo-TC to oral vitamin B-12. DESIGN: Adult (18-49 y) male and female participants (n = 21) with normal vitamin B-12 status were given three 9-mug doses...... of vitamin B-12 at 6-h intervals beginning early morning (baseline) on day 1. Blood was drawn at 17 timed intervals over the course of 3 d for the analysis of holo-TC and other indicators of vitamin B-12 status. RESULTS: Mean holo-TC increased significantly (P

Vitamin B12 absorption judged by measurement of holotranscobalamin, active vitamin B12: evaluation of a commercially available EIA kit.

Science.gov (United States)

Greibe, Eva; Nexo, Ebba

2011-11-01

Active vitamin B12 absorption is followed by an increase in holotranscobalamin (holoTC) upon loading with a high physiological dose of the vitamin (the CobaSorb test). This study evaluates the use of a newly launched EIA kit for measurement of holoTC (active B12) in relation to the CobaSorb test. Intra-assay imprecision and linearity of the EIA kit was examined, employing serum pools of increasing holoTC concentrations. For the CobaSorb test, holoTC was measured before and after loading with 3-times 9 μg of vitamin B12 employing both the in-house ELISA and the EIA kit (n=25). The EIA kit showed an intra-assay CV between 2.2% and 5.8% for holoTC values ranging from 21 to 80 pmol/L. Employing diluted serum samples resulted in spurious high values of holoTC. The EIA kit performed well in relation to the CobaSorb test and classified the patients studied as capable of absorbing vitamin B12 (n=10) or not (n=15), as did the in-house ELISA. The Active B12 (holoTC) EIA kit proved suitable for use with the CobaSorb test, but not for analysis of diluted serum samples.

Synthesis and crystal structure of MgB12

International Nuclear Information System (INIS)

Adasch, Volker; Hess, Kai-Uwe; Ludwig, Thilo; Vojteer, Natascha; Hillebrecht, Harald

2006-01-01

Single crystals of MgB 12 were synthesized from the elements in a Mg/Cu melt at 1600deg. C. MgB 12 crystallizes orthorhombic in space group Pnma with a=16.632(3)A, b=17.803(4)A and c=10.396(2)A. The crystal structure (Z=30, 5796 reflections, 510 variables, R 1 (F)=0.049, wR 2 (I)=0.134) consists of a three dimensional net of B 12 icosahedra and B 21 units in a ratio 2:1. The B 21 units are observed for the first time in a solid compound. Mg is on positions with partial occupation. The summation reveals the composition MgB 12.35 or Mg 0.97 B 12 , respectively. This is in good agreement with the value of MgB 11.25 as expected by electronic reasons to stabilize the boron polyhedra B 12 2- and B 21 4-

Vitamin B12 and Semen Quality.

Science.gov (United States)

Banihani, Saleem Ali

2017-06-09

Various studies have revealed the effects of vitamin B12, also named cobalamin, on semen quality and sperm physiology; however, these studies collectively are still unsummarized. Here, we systematically discuss and summarize the currently understood role of vitamin B12 on semen quality and sperm physiology. We searched the Web of Science, PubMed, and Scopus databases for only English language articles or abstracts from September 1961 to March 2017 (inclusive) using the key words "vitamin B12" and "cobalamin" versus "sperm". Certain relevant references were included to support the empirical as well as the mechanistic discussions. In conclusion, the mainstream published work demonstrates the positive effects of vitamin B12 on semen quality: first, by increasing sperm count, and by enhancing sperm motility and reducing sperm DNA damage, though there are a few in vivo system studies that have deliberated some adverse effects. The beneficial effects of vitamin B12 on semen quality may be due to increased functionality of reproductive organs, decreased homocysteine toxicity, reduced amounts of generated nitric oxide, decreased levels of oxidative damage to sperm, reduced amount of energy produced by spermatozoa, decreased inflammation-induced semen impairment, and control of nuclear factor-κB activation. However, additional research, mainly clinical, is still needed to confirm these positive effects.

Assay of vitamin B12

International Nuclear Information System (INIS)

Tovey, K.C.; Carrick, D.T.

1982-01-01

A radioassay is described for vitamin B12 which involves denaturing serum protein binding proteins with alkali. In the denaturation step a dithiopolyol and cyanide are used and in the intrinsic factor assay step a vitamin B12 analogue such as cobinamide is used to bind with any remaining serum proteins. The invention also includes a kit in which the dithiopolyol is provided in admixture with the alkali. The dithiopolyol may be dithiothreitol or dithioerythritol. (author)

Theoretical assessment of the electro-optical features of the group III nitrides (B{sub 12}N{sub 12}, Al{sub 12}N{sub 12} and Ga{sub 12}N{sub 12}) and group IV carbides (C{sub 24}, Si{sub 12}C{sub 12} and Ge{sub 12}C{sub 12}) nanoclusters encapsulated with alkali metals (Li, Na and K)

Energy Technology Data Exchange (ETDEWEB)

Tahmasebi, Elham [Chemistry Department, Faculty of Science, Lorestan University, Khorram Abad, Lorestan (Iran, Islamic Republic of); Shakerzadeh, Ehsan, E-mail: e.shakerzadeh@scu.ac.ir [Chemistry Department, Faculty of Science, Shahid Chamran University, Ahvaz (Iran, Islamic Republic of); Biglari, Zeinab [Chemistry Department, Faculty of Science, Lorestan University, Khorram Abad, Lorestan (Iran, Islamic Republic of)

2016-02-15

Graphical abstract: - Highlights: • Encapsulation of Li, Na and K narrow the HOMO–LUMO gaps of the clusters. • The group III nitrides nanoclusters strongly interacted with the alkali metals. • First hyperpolarizabilities remarkably enhance for B{sub 12}N{sub 12} encapsulated with Na/K. - Abstract: Density functional theory (DFT) calculations have been carried out to study the influence of alkali metals (Li, Na and K) encapsulation within the group III nitrides (B{sub 12}N{sub 12}, Al{sub 12}N{sub 12} and Ga{sub 12}N{sub 12}) and the group IV carbides (C{sub 24}, Si{sub 12}C{sub 12}and Ge{sub 12}C{sub 12}) nanoclusters. The encapsulation of Li, Na and K atoms is found to narrow the HOMO–LUMO gaps of the considered clusters. The electronic properties of these clusters, especially the group III nitrides nanoclusters, are strongly sensitive to interaction with the alkali metals. Moreover it is observed that the encapsulation of alkali metals enhances the first hyperpolarizabilities of B{sub 12}N{sub 12} nanocluster. Surprisingly, due to the alkali metals encapsulation within B{sub 12}N{sub 12} nanocluster, the first hyperpolarizability values are remarkably increased to 8505.49 and 122,503.76 a.u. for Na@B{sub 12}N{sub 12} and K@B{sub 12}N{sub 12}, respectively. Also the TD-DFT calculations at both CAM-B3LYP/6-311+G(d) and PBE0/6-311+G(d) levels of theory are also performed to investigate the origin of first hyperpolarizabilities.

Dietary sources of vitamin B-12 and their association with vitamin B-12 status markers in healthy older adults in the B-PROOF study

NARCIS (Netherlands)

Brouwer-Brolsma, E.M.; Dhonukshe-Rutten, R.A.M.; Wijngaarden, van J.P.; Zwaluw, van der N.L.; Velde, van der N.; Groot, de C.P.G.M.

2015-01-01

Low vitamin B-12 concentrations are frequently observed among older adults. Malabsorption is hypothesized to be an important cause of vitamin B-12 inadequacy, but serum vitamin B-12 may also be differently affected by vitamin B-12 intake depending on food source. We examined associations between

Dietary Sources of Vitamin B-12 and Their Association with Vitamin B-12 Status Markers in Healthy Older Adults in the B-PROOF Study

NARCIS (Netherlands)

Brouwer-Brolsma, Elske M.; Dhonukshe-Rutten, Rosalie A. M.; van Wijngaarden, Janneke P.; Zwaluw, Nikita L. van der; Velde, Nathalie van der; de Groot, Lisette C. P. G. M.

2015-01-01

Low vitamin B-12 concentrations are frequently observed among older adults. Malabsorption is hypothesized to be an important cause of vitamin B-12 inadequacy, but serum vitamin B-12 may also be differently affected by vitamin B-12 intake depending on food source. We examined associations between

Dietary sources of vitamin B-12 and their association with vitamin B-12 status markers in healthy older adults in the B-PROOF study

NARCIS (Netherlands)

E.M. Brouwer-Brolsma (Elske); R.A.M. Dhonukshe-Rutten (Rosalie); J.P. van Wijngaarden (Janneke); N.L. van der Zwaluw (N.); N. van der Velde (Nathalie); L.C.P.G.M. de Groot (Lisette)

2015-01-01

textabstractLow vitamin B-12 concentrations are frequently observed among older adults. Malabsorption is hypothesized to be an important cause of vitamin B-12 inadequacy, but serum vitamin B-12 may also be differently affected by vitamin B-12 intake depending on food source. We examined associations

Fuzzy modeling for Vitamin B12 deficiency

NARCIS (Netherlands)

Wilbik, A.M.; van Loon, S.L.M.; Boer, A.K.; Kaymak, U.; Scharnhorst, V.; Carvalho, J.; Lesot, M.J.; Kaymak, U.; Vieira, S.; Bouchon-Meunier, B.; Yager, R.

2016-01-01

Blood vitamin B12 levels are not representative for actual vitamin B12 status in tissue. Instead plasma methylmalonic acid (MMA) levels can be measured because MMA concentrations increase relatively early in the course of vitamin B12 deficiency. However, MMA levels in plasma may also be increased

Simultaneous radioassay of folate and vitamin B12

International Nuclear Information System (INIS)

Gutcho, S.; Mansbach, L.

1979-01-01

A serum sample is heated at an alkaline pH to release folate and vitamin B 12 from endogenous binders. A simultaneous radioassay for folate and vitamin B 12 is effected by contacting the sample with binder for folate, binder for vitamin B 12 , folote labeled with one radioactive isotope and vitamin B 12 labeled with another radioacitve isotope, followed by separation of bound and free portions, and determination of the radioactivity of at least one of the portions. The amounts of folate and vitamin B 12 present in the sample may be determined from standard curves

Solid-phase radioimmunoassay for vitamin B12 in serum, with use of radioiodinated tyrosine methyl ester of vitamin B12

International Nuclear Information System (INIS)

Endres, D.B.; Painter, K.; Niswender, G.D.

1978-01-01

Although radioassays for vitamin B 12 with use of any of several binding proteins have been available for many years, a radioimmunoassay for B 12 has not been reported. We describe here such a radioimmunoassay, incorporating, for the first time, a radioiodinated tyrosine methyl ester of B 12 as the radioactive tracer. Polypropylene tubes are coated with antiserum raised in a rabbit against B 12 /bovine serum albumin to simplify the separation of bound and free radioactivity. Factors affecting the preparation of coated tubes are described. The assay is accurate, sensitive, precise, and specific for vitamin B 12 . Accuracy of the assay is unaffected by the presence of denatured protein. The advantages of this radioimmunoassay over conventional radioassays are discussed

Vitamin B12 and Semen Quality

Directory of Open Access Journals (Sweden)

Saleem Ali Banihani

2017-06-01

Full Text Available Various studies have revealed the effects of vitamin B12, also named cobalamin, on semen quality and sperm physiology; however, these studies collectively are still unsummarized. Here, we systematically discuss and summarize the currently understood role of vitamin B12 on semen quality and sperm physiology. We searched the Web of Science, PubMed, and Scopus databases for only English language articles or abstracts from September 1961 to March 2017 (inclusive using the key words “vitamin B12” and “cobalamin” versus “sperm”. Certain relevant references were included to support the empirical as well as the mechanistic discussions. In conclusion, the mainstream published work demonstrates the positive effects of vitamin B12 on semen quality: first, by increasing sperm count, and by enhancing sperm motility and reducing sperm DNA damage, though there are a few in vivo system studies that have deliberated some adverse effects. The beneficial effects of vitamin B12 on semen quality may be due to increased functionality of reproductive organs, decreased homocysteine toxicity, reduced amounts of generated nitric oxide, decreased levels of oxidative damage to sperm, reduced amount of energy produced by spermatozoa, decreased inflammation-induced semen impairment, and control of nuclear factor-κB activation. However, additional research, mainly clinical, is still needed to confirm these positive effects.

How common is vitamin B-12 deficiency?

Science.gov (United States)

Allen, Lindsay H

2009-02-01

In considering the vitamin B-12 fortification of flour, it is important to know who is at risk of vitamin B-12 deficiency and whether those individuals would benefit from flour fortification. This article reviews current knowledge of the prevalence and causes of vitamin B-12 deficiency and considers whether fortification would improve the status of deficient subgroups of the population. In large surveys in the United States and the United Kingdom, approximately 6% of those aged > or =60 y are vitamin B-12 deficient (plasma vitamin B-12 life. In developing countries, deficiency is much more common, starting in early life and persisting across the life span. Inadequate intake, due to low consumption of animal-source foods, is the main cause of low serum vitamin B-12 in younger adults and likely the main cause in poor populations worldwide; in most studies, serum vitamin B-12 concentration is correlated with intake of this vitamin. In older persons, food-bound cobalamin malabsorption becomes the predominant cause of deficiency, at least in part due to gastric atrophy, but it is likely that most elderly can absorb the vitamin from fortified food. Fortification of flour with vitamin B-12 is likely to improve the status of most persons with low stores of this vitamin. However, intervention studies are still needed to assess efficacy and functional benefits of increasing intake of the amounts likely to be consumed in flour, including in elderly persons with varying degrees of gastric atrophy.

Gastric emptying in patients with vitamin B12 deficiency

International Nuclear Information System (INIS)

Yagci, Muenci; Yamac, Kadri; Acar, Kadir; Haznedar, Rauf; Cingi, Elif; Kitapci, Mehmet

2002-01-01

The clinical presentation of patients with vitamin B 12 deficiency varies in a spectrum ranging from haematological disorders to neuropsychiatric diseases. In rare cases, orthostatic hypotension, impotence, constipation and urinary retention have been attributed to autonomic nervous system dysfunction due to vitamin B 12 deficiency. The aim of this study was to evaluate the effect of vitamin B 12 deficiency on autonomic nervous system function by studying gastric emptying times (T 1/2 ). Twenty patients with newly diagnosed vitamin B 12 deficiency and 12 control patients with gastritis and normal vitamin B 12 levels were enrolled in this study. Gastroduodenoscopy, endoscopic biopsy, histopathological evaluation of the biopsy specimens and radionuclide gastric emptying studies were performed. After vitamin B 12 replacement therapy for 3 months, radionuclide gastric emptying studies were repeated. Mean gastric emptying T 1/2 in patients before and after treatment and in controls were 103.83±48.80 min, 90.00±17.29 min and 74.55±8.52 min, respectively. The difference in mean gastric emptying T 1/2 between patients before treatment and controls was statistically significant (P 12 treatment (P 1/2 was somewhat shorter. There were no positive or negative correlations between gastric emptying T 1/2 and the following parameters: haemoglobin, vitamin B 12 level and Helicobacter pylori positivity. In conclusion, gastric emptying T 1/2 was prolonged in patients with vitamin B 12 deficiency and this prolongation was not corrected after vitamin B 12 replacement therapy. Although autonomic nervous system dysfunction due to vitamin B 12 deficiency rarely gives rise to clinical manifestations, latent dysfunction demonstrated by laboratory tests seems to be a frequent phenomenon. The level of vitamin B 12 does not correlate with the degree of autonomic nervous system dysfunction measured by radionuclide gastric emptying studies. (orig.)

Forms and Amounts of Vitamin B12 in Infant Formula: A Pilot Study

DEFF Research Database (Denmark)

Greibe, Eva; Nexø, Ebba

2016-01-01

12 (cyano-B12). Here we test commercially available infant formulas. METHODS: Eleven commercially available infant formulas were measured for content of B12 and analyzed for the presence of B12-binding proteins and forms of B12 using size exclusion chromatography and HPLC. RESULTS: All infant...... formulas contained B12 by and large in accord with the informations given on the package inserts. None of the formulas contained protein-bound B12, and cyano-B12 accounted for 19-78% of the total amount of B12 present, while hydroxo-B12 constituted more or less the rest. CONCLUSIONS: This pilot study shows...... that infant formula differs from breast milk in providing the infant with free B12, rather than protein-bound B12, and by a relative high content of cyano-B12. The consequence of supplying the infant with synthetic cyano-B12 remains to be elucidated....

Simultaneous radioassay of folate and vitamin B12

International Nuclear Information System (INIS)

1981-01-01

An improved simultaneous radioassay for folate and vitamin B 12 in biological specimens is described. A sample containing folate and vitamin B 12 is contacted with 125 I-folate and 57 Co-vitamin B 12 and their respective specific binders. After separation of the bound and free portions, the radioactivity in the portions is counted and the amounts of folate and vitamin B 12 then determined from standard curves. (U.K.)

Vitamin B12 absorption capacity in healthy children

International Nuclear Information System (INIS)

Hjelt, K.; Krasilnikoff, P.A.

1986-01-01

B12 absorption was investigated in 47 healthy children aged 7 months to 15.8 years (median 4.9 years). The patients had either recovered from giardiasis, the post-gastroenteritis syndrome, or had celiac disease in remission (treated with a gluten-free diet). The B12 absorption was measured by a double-isotope technique using 57 CoB12 and 51 CrCl 3 , the latter being the inabsorbable marker. The radiation dose was minimal. The results were presented as fractional absorption of B12 (FAB12). Within the different age groups, the absorption test was performed by means of the following oral amounts of B12: 0- less than 1 year, 0.5 microgram; 1-3 years: 1.7 micrograms, 4-6 years, 2.5 micrograms; 7-10 years; 3.3 micrograms; and 11-15 years, 4.5 micrograms. When using these oral amounts of B12, the medians (and ranges) of FAB12 were found to be: 1-3 years (n = 18), 37% (16-80%); 4-6 years (n = 10), 27% (19-40%); 7-10 years (n = 9), 32% (21-44%); and 11-15 years (n = 8), 27% (19-59%). The FAB12 in two children aged 7 and 11 months was 31% and 32%, respectively. These results may be interpretated as reference values for B12 absorption in children. Further absorption tests were performed in seven children representing the four age groups from 1 to 15 years. When a high oral amount of B12 was given (i.e., three times the saturation dose), the FAB12 ranged from 0 to 20% (median 9%), whereas a low amount (i.e., one-ninth of the saturation dose) produced fractional absorptions from 65 to 82% (median 74%)

Vitamin B12 absorption capacity in healthy children

Energy Technology Data Exchange (ETDEWEB)

Hjelt, K.; Krasilnikoff, P.A.

1986-03-01

B12 absorption was investigated in 47 healthy children aged 7 months to 15.8 years (median 4.9 years). The patients had either recovered from giardiasis, the post-gastroenteritis syndrome, or had celiac disease in remission (treated with a gluten-free diet). The B12 absorption was measured by a double-isotope technique using /sup 57/CoB12 and /sup 51/CrCl/sub 3/, the latter being the inabsorbable marker. The radiation dose was minimal. The results were presented as fractional absorption of B12 (FAB12). Within the different age groups, the absorption test was performed by means of the following oral amounts of B12: 0- less than 1 year, 0.5 microgram; 1-3 years: 1.7 micrograms, 4-6 years, 2.5 micrograms; 7-10 years; 3.3 micrograms; and 11-15 years, 4.5 micrograms. When using these oral amounts of B12, the medians (and ranges) of FAB12 were found to be: 1-3 years (n = 18), 37% (16-80%); 4-6 years (n = 10), 27% (19-40%); 7-10 years (n = 9), 32% (21-44%); and 11-15 years (n = 8), 27% (19-59%). The FAB12 in two children aged 7 and 11 months was 31% and 32%, respectively. These results may be interpretated as reference values for B12 absorption in children. Further absorption tests were performed in seven children representing the four age groups from 1 to 15 years. When a high oral amount of B12 was given (i.e., three times the saturation dose), the FAB12 ranged from 0 to 20% (median 9%), whereas a low amount (i.e., one-ninth of the saturation dose) produced fractional absorptions from 65 to 82% (median 74%).

New method for the radioactive determination of vitamin B12

International Nuclear Information System (INIS)

Lewin, Nathan; Fries, J.E.; Richards, C.S.

1975-01-01

A description is given of a method for the radioactive determination of vitamin B12 in a sample solution of serum in which a radioactive tracer of vitamin B12 and the vitamin B12 of the serum compete with respect to an intrinsic factor of limited linking capacity. The free radioactive vitamin B12 and the free vitamin B12 of the serum are separated from the intrinsic factor and from the radioactive vitamin B12 and from the serum vitamin B12 linked to this factor, before the radioactivity is measured against standard values. The method consists in separating the free radioactive vitamin B12 and the free serum vitamin B12 of the intrinsic factor and portions of radioactive and serum vitamin B12 linked to this factor, by adding an adequate quantity of bentonite to adsorb the free radioactive vitamin B12 and free serum vitamin B12 so that the intrinsic factor surface floating solution in association with the linked radioactive vitamin B12 and the linked serum vitamin B12 may be physically isolated from the solid bentonite that has adsorbed the free radioactive vitamin B12 and the free serum vitamin B12 [fr

Forms and Amounts of Vitamin B12 in Infant Formula: A Pilot Study.

Directory of Open Access Journals (Sweden)

Eva Greibe

Full Text Available Infant formula is based on cow's milk and designed to mimic breast milk for substitution. Vitamin B12 (B12 is bound to proteins in both breast milk and cow's milk, and in milk from both species the vitamin occurs mainly in its natural form such as hydroxo-B12 with little or no synthetic B12 (cyano-B12. Here we test commercially available infant formulas.Eleven commercially available infant formulas were measured for content of B12 and analyzed for the presence of B12-binding proteins and forms of B12 using size exclusion chromatography and HPLC.All infant formulas contained B12 by and large in accord with the informations given on the package inserts. None of the formulas contained protein-bound B12, and cyano-B12 accounted for 19-78% of the total amount of B12 present, while hydroxo-B12 constituted more or less the rest.This pilot study shows that infant formula differs from breast milk in providing the infant with free B12, rather than protein-bound B12, and by a relative high content of cyano-B12. The consequence of supplying the infant with synthetic cyano-B12 remains to be elucidated.

Forms and Amounts of Vitamin B12 in Infant Formula: A Pilot Study.

Science.gov (United States)

Greibe, Eva; Nexo, Ebba

2016-01-01

Infant formula is based on cow's milk and designed to mimic breast milk for substitution. Vitamin B12 (B12) is bound to proteins in both breast milk and cow's milk, and in milk from both species the vitamin occurs mainly in its natural form such as hydroxo-B12 with little or no synthetic B12 (cyano-B12). Here we test commercially available infant formulas. Eleven commercially available infant formulas were measured for content of B12 and analyzed for the presence of B12-binding proteins and forms of B12 using size exclusion chromatography and HPLC. All infant formulas contained B12 by and large in accord with the informations given on the package inserts. None of the formulas contained protein-bound B12, and cyano-B12 accounted for 19-78% of the total amount of B12 present, while hydroxo-B12 constituted more or less the rest. This pilot study shows that infant formula differs from breast milk in providing the infant with free B12, rather than protein-bound B12, and by a relative high content of cyano-B12. The consequence of supplying the infant with synthetic cyano-B12 remains to be elucidated.

[Vitamin B12 deficiency: what's new?].

Science.gov (United States)

Braillard, O; Casini, A; Samii, K; Rufenacht, P; Junod, Perron N

2012-09-26

Vitamin B12 screening is only recommended among symptomatic patients or in those with risk factors. The main cause of vitamin B12 deficiency is the food cobalamin malabsorption syndrom. Holotranscobalamin is a more reliable marker than cyanocobalamin to confirm vitamin B12 deficiency, but it has not been validated yet in complex situations. An autoimmune gastritis must be excluded in the absence of risk factors but in the presence of a probable deficiency. Oral substitution treatment is effective but requires excellent therapeutic compliance and close follow-up to monitor the response to treatment. It has not yet been studied among patients suffering from severe symptoms, inflammatory bowel disease and ileal resection.

Vitamin B12 and Folate Test

Science.gov (United States)

... offer the folate test. Can taking too many vitamin B12 and folic acid supplements hurt me? Not usually. Since B12 and folic acid are water-soluble, the body will rid itself of any excess by excreting it in the urine. However, taking ...

Direct Rehydrogenation of LiBH4 from H-Deficient Li2B12H12−x

Directory of Open Access Journals (Sweden)

Yigang Yan

2018-03-01

Full Text Available Li2B12H12 is commonly considered as a boron sink hindering the reversible hydrogen sorption of LiBH4. Recently, in the dehydrogenation process of LiBH4 an amorphous H-deficient Li2B12H12−x phase was observed. In the present study, we investigate the rehydrogenation properties of Li2B12H12−x to form LiBH4. With addition of nanostructured cobalt boride in a 1:1 mass ratio, the rehydrogenation properties of Li2B12H12−x are improved, where LiBH4 forms under milder conditions (e.g., 400 °C, 100 bar H2 with a yield of 68%. The active catalytic species in the reversible sorption reaction is suggested to be nonmetallic CoxB (x = 1 based on 11B MAS NMR experiments and its role has been discussed.

On the oxidation of the three-dimensional aromatics [B(12)X(12)](2-) (X=F, Cl, Br, I).

Science.gov (United States)

Boeré, René T; Derendorf, Janis; Jenne, Carsten; Kacprzak, Sylwia; Kessler, Mathias; Riebau, Rainer; Riedel, Sebastian; Roemmele, Tracey L; Rühle, Monika; Scherer, Harald; Vent-Schmidt, Thomas; Warneke, Jonas; Weber, Stefan

2014-04-07

.68 and +2.29 V (lSO2 , versus ferrocene/ferrocenium (Fc(0/+) ))), the second process is irreversible (with oxidation potentials ranging from +2.63 to +2.71 V (lSO2 , versus Fc(0/+) )). [B12 I12 ](2-) showed a complex oxidation behavior in cyclic voltammetry experiments, presumably owing to decomposition of the cluster anion under release of iodide, which also explains the failure to isolate the respective radical by chemical oxidation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Maximal load of the vitamin B12 transport system

DEFF Research Database (Denmark)

Lildballe, Dorte L; Mutti, Elena; Birn, Henrik

2012-01-01

Several studies suggest that the vitamin B12 (B12) transport system can be used for the cellular delivery of B12-conjugated drugs, also in long-term treatment Whether this strategy will affect the endogenous metabolism of B12 is not known. To study the effect of treatment with excess B12...

21 CFR 862.1810 - Vitamin B12 test system.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vitamin B12 test system. 862.1810 Section 862.1810....1810 Vitamin B12 test system. (a) Identification. A vitamin B12 test system is a device intended to measure vitamin B12 in serum, plasma, and urine. Measurements obtained by this device are used in the...

Assessment of Serum Vitamin B12 Concentrations in Patients with a ...

African Journals Online (AJOL)

Serum vitamin B12 levels were obtained preoperatively and every 6 months postoperatively. All patients received 100 microgram of vitamin B-12 twice yearly. Follow up ranged from 3-10 years. Results All 16 patients included in the study had a normal concentration of serum vitamin B12 preoperatively with a range of ...

Hampered Vitamin B12 Metabolism in Gaucher Disease?

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Luciana Hannibal PhD

2017-02-01

Full Text Available Untreated vitamin B 12 deficiency manifests clinically with hematological abnormalities and combined degeneration of the spinal cord and polyneuropathy and biochemically with elevated homocysteine (Hcy and methylmalonic acid (MMA. Vitamin B 12 metabolism involves various cellular compartments including the lysosome, and a disruption in the lysosomal and endocytic pathways induces functional deficiency of this micronutrient. Gaucher disease (GD is characterized by dysfunctional lysosomal metabolism brought about by mutations in the enzyme beta-glucocerebrosidase (Online Mendelian Inheritance in Man (OMIM: 606463; Enzyme Commission (EC 3.2.1.45, gene: GBA1 . In this study, we collected and examined available literature on the associations between GD, the second most prevalent lysosomal storage disorder in humans, and hampered vitamin B 12 metabolism. Results from independent cohorts of patients show elevated circulating holotranscobalamin without changes in vitamin B 12 levels in serum. Gaucher disease patients under enzyme replacement therapy present normal levels of Hcy and MMA. Although within the normal range, a significant increase in Hcy and MMA with normal serum vitamin B 12 was documented in treated GD patients with polyneuropathy versus treated GD patients without polyneuropathy. Thus, a functional deficiency of vitamin B 12 caused by disrupted lysosomal metabolism in GD is a plausible mechanism, contributing to the neurological form of the disorder but this awaits confirmation. Observational studies suggest that an assessment of vitamin B 12 status prior to the initiation of enzyme replacement therapy may shed light on the role of vitamin B 12 in the pathogenesis and progression of GD.

PODAAC-RSX12-L2B11

Data.gov (United States)

National Aeronautics and Space Administration — This dataset contains the RapidScat Level 2B 12.5km Version 1.1 science-quality ocean surface wind vectors. The Level 2B wind vectors are binned on a 12.5 km Wind...

Vitamin B12-Containing Plant Food Sources for Vegetarians

Science.gov (United States)

Watanabe, Fumio; Yabuta, Yukinori; Bito, Tomohiro; Teng, Fei

2014-01-01

The usual dietary sources of Vitamin B12 are animal-derived foods, although a few plant-based foods contain substantial amounts of Vitamin B12. To prevent Vitamin B12 deficiency in high-risk populations such as vegetarians, it is necessary to identify plant-derived foods that contain high levels of Vitamin B12. A survey of naturally occurring plant-derived food sources with high Vitamin B12 contents suggested that dried purple laver (nori) is the most suitable Vitamin B12 source presently available for vegetarians. Furthermore, dried purple laver also contains high levels of other nutrients that are lacking in vegetarian diets, such as iron and n-3 polyunsaturated fatty acids. Dried purple laver is a natural plant product and it is suitable for most people in various vegetarian groups. PMID:24803097

Vitamin B12-Containing Plant Food Sources for Vegetarians

Directory of Open Access Journals (Sweden)

Fumio Watanabe

2014-05-01

Full Text Available The usual dietary sources of Vitamin B12 are animal-derived foods, although a few plant-based foods contain substantial amounts of Vitamin B12. To prevent Vitamin B12 deficiency in high-risk populations such as vegetarians, it is necessary to identify plant-derived foods that contain high levels of Vitamin B12. A survey of naturally occurring plant-derived food sources with high Vitamin B12 contents suggested that dried purple laver (nori is the most suitable Vitamin B12 source presently available for vegetarians. Furthermore, dried purple laver also contains high levels of other nutrients that are lacking in vegetarian diets, such as iron and n-3 polyunsaturated fatty acids. Dried purple laver is a natural plant product and it is suitable for most people in various vegetarian groups.

A first-principles study on the adsorption behavior of amphetamine on pristine, P- and Al-doped B12N12 nano-cages

Science.gov (United States)

Bahrami, Aidin; Seidi, Shahram; Baheri, Tahmineh; Aghamohammadi, Mohammad

2013-12-01

The first-principles computations using density functional theory (DFT) calculations at the M062X/6-311++G** level have been applied to scrutinize the adsorption behavior of amphetamine (AMP) molecule on the external surface of pristine, P- and Al-doped B12N12 nano-cages. In order to gain insight into the binding features of pristine and doped B12N12 complexes as adsorbent with AMP, the structural and electronic parameters as well as the Atoms in Molecules (AIM) properties were examined. The results showed that AMP prefers to adsorb via its nitrogen atom on the Lewis acid sites of B and Al atoms of the nano-cages. On the basis of calculated density of states, the interaction of AMP with the external wall of B12N12 leads to the remarkable differences in their conductivities. Presence of polar solvent increases the AMP adsorption on the nano-cage. In addition, AIM based analyses indicated an electrostatic nature for N-B interaction in Amph-B12N12 and partial covalent for N-Al in AMP-B11AlN12. Based on calculated results, the B12N12 and B11AlN12 nano-cages are expected to be a potential efficient adsorbent as well as sensors for adsorption of AMP in environmental systems.

Characterization of the electronic properties of YB{sub 12}, ZrB{sub 12}, and LuB{sub 12} using {sup 11}B NMR and first-principles calculations

Energy Technology Data Exchange (ETDEWEB)

Jaeger, B [Institut fuer Physikalische Chemie, Universitaet Wien, Waehringer Strasse 42, 1090 Vienna (Austria); Paluch, S [Institute for Low Temperature and Structure Research, Polish Academy of Sciences, PO Box 1410, 50-950 Wroclaw (Poland); Zogal, O J [Institute for Low Temperature and Structure Research, Polish Academy of Sciences, PO Box 1410, 50-950 Wroclaw (Poland); Wolf, W [Materials Design s. a. r. l., 44, avenue F.-A. Bartholdi, 72000 Le Mans (France); Herzig, P [Institut fuer Physikalische Chemie, Universitaet Wien, Waehringer Strasse 42, 1090 Vienna (Austria); Filippov, V B [Institute for Problems of Materials Science, Academy of Sciences of Ukraine, 3 Krzhyzhanovsky street, 03680 Kiev, Ukraine (Ukraine); Shitsevalova, N [Institute for Problems of Materials Science, Academy of Sciences of Ukraine, 3 Krzhyzhanovsky street, 03680 Kiev, Ukraine (Ukraine); Paderno, Y [Institute for Problems of Materials Science, Academy of Sciences of Ukraine, 3 Krzhyzhanovsky street, 03680 Kiev, Ukraine (Ukraine)

2006-03-01

Three metallic dodecaborides, YB{sub 12}, ZrB{sub 12} and LuB{sub 12}, have been investigated by electric-field gradient (EFG) measurements at the boron sites using the {sup 11}B nuclear magnetic resonance (NMR) technique and by performing first-principles calculations. The NMR powder spectra reveal patterns typical for a completely asymmetric EFG tensor, i.e., an {eta} parameter close to unity. The absolute values of V{sub zz} (the largest component of the EFG) are determined from the spectra and they range between 11 x 10{sup 20} V m{sup -2} and 11.6 x 10{sup 20} V m{sup -2} with an uncertainty of 0.8 x 10{sup 20} V m{sup -2}, being in very good agreement with the first-principles results. In addition the electronic structure and chemical bonding are analysed from partial densities of states and electron densities.

Gastric emptying in patients with vitamin B{sub 12} deficiency

Energy Technology Data Exchange (ETDEWEB)

Yagci, Muenci; Yamac, Kadri; Acar, Kadir; Haznedar, Rauf [Department of Hematology, Gazi Medical School (Turkey); Cingi, Elif; Kitapci, Mehmet [Department of Nuclear Medicine, Gazi Medical School (Turkey)

2002-09-01

The clinical presentation of patients with vitamin B{sub 12} deficiency varies in a spectrum ranging from haematological disorders to neuropsychiatric diseases. In rare cases, orthostatic hypotension, impotence, constipation and urinary retention have been attributed to autonomic nervous system dysfunction due to vitamin B{sub 12} deficiency. The aim of this study was to evaluate the effect of vitamin B{sub 12} deficiency on autonomic nervous system function by studying gastric emptying times (T{sub 1/2}). Twenty patients with newly diagnosed vitamin B{sub 12} deficiency and 12 control patients with gastritis and normal vitamin B{sub 12} levels were enrolled in this study. Gastroduodenoscopy, endoscopic biopsy, histopathological evaluation of the biopsy specimens and radionuclide gastric emptying studies were performed. After vitamin B{sub 12} replacement therapy for 3 months, radionuclide gastric emptying studies were repeated. Mean gastric emptying T{sub 1/2} in patients before and after treatment and in controls were 103.83{+-}48.80 min, 90.00{+-}17.29 min and 74.55{+-}8.52 min, respectively. The difference in mean gastric emptying T{sub 1/2} between patients before treatment and controls was statistically significant (P<0.01). The statistically significant difference persisted after vitamin B{sub 12} treatment (P<0.05), though mean gastric emptying T{sub 1/2} was somewhat shorter. There were no positive or negative correlations between gastric emptying T{sub 1/2} and the following parameters: haemoglobin, vitamin B{sub 12} level and Helicobacter pylori positivity. In conclusion, gastric emptying T{sub 1/2} was prolonged in patients with vitamin B{sub 12} deficiency and this prolongation was not corrected after vitamin B{sub 12} replacement therapy. Although autonomic nervous system dysfunction due to vitamin B{sub 12} deficiency rarely gives rise to clinical manifestations, latent dysfunction demonstrated by laboratory tests seems to be a frequent phenomenon

Mechanism of ({sup 14}N, {sup 12}B) reactions at intermediate energy leading to large spin-polarization of {sup 12}B

Energy Technology Data Exchange (ETDEWEB)

Mitsuoka, Shin-ichi [Osaka Univ., Ibaraki (Japan). Research Center for Nuclear Physics; Shimoda, Tadashi; Miyatake, Hiroari [and others

1996-05-01

To study mechanisms of the ({sup 14}N, {sup 12}B) reactions at intermediate energies, double differential cross section and nuclear spin-polarization of the {sup 12}B projectile-like fragments have been measured as a function of longitudinal momentum in the angular range of 0deg - 9deg. Large spin-polarization of the reaction products {sup 12}B has been observed in the {sup 9}Be({sup 14}N, {sup 12}B) reaction at 39.3 MeV/u. The momentum distributions at forward angles exhibit characteristic features which can not be understood by the current projectile fragmentation picture. It is shown that by assuming the existence of direct two-proton transfer process in addition to the fragmentation process, both the cross section and polarization of {sup 12}B fragments are successfully explained. The target and incident energy dependence of the momentum distribution are also explained reasonably. (author)

Vitamin B12 Deficiency in Relation to Functional Disabilities

Directory of Open Access Journals (Sweden)

Heather E. Rasmussen

2013-11-01

Full Text Available This study was designed to assess whether symptoms, functional measures, and reported disabilities were associated with vitamin B12 (B12 deficiency when defined in three ways. Participants, aged 60 or more years of age, in 1999–2002 National Health and Nutrition Examination Surveys (NHANES were categorized in relation to three previously used definitions of B12 deficiency: (1 serum B12 20 μmol/L; and (3 serum B12 0.21 μmol/L. Functional measures of peripheral neuropathy, balance, cognitive function, gait speed, along with self-reported disability (including activities of daily living were examined with standardized instruments by trained NHANES interviewers and technicians. Individuals identified as B12 deficient by definition 2 were more likely to manifest peripheral neuropathy OR (odds (95% confidence intervals, p value: 9.70 (2.24, 42.07, 0.004 and report greater total disability, 19.61 (6.22, 61.86 0.0001 after adjustments for age, sex, race, serum creatinine, and ferritin concentrations, smoking, diabetes, and peripheral artery disease. Smaller, but significantly increased, odds of peripheral neuropathy and total disability were also observed when definition 3 was applied. Functional measures and reported disabilities were associated with B12 deficiency definitions that include B12 biomarkers (homocysteine or methylmalonic acid. Further study of these definitions is needed to alert clinicians of possible subclinical B12 deficiency because functional decline amongst older adults may be correctable if the individual is B12 replete.

Racial difference in serum Vitamin B12 levels

International Nuclear Information System (INIS)

Kwee, H.G.; Bowman, H.S.; Wells, L.W.

1985-01-01

Measurements of the serum Vitamin B 12 concentrations of 49 black and 49 white healthy adults demonstrate a significantly higher mean serum Vitamin B 12 level in blacks when compared to whites. The reason for this difference appears to be genetic, although environmental factors may also be involved. It is suggested that clinical laboratories should establish their own separate reference values of serum Vitamin B 12 for blacks and whites in order to prevent misinterpretation of test results

Vitamin B 12 absorption: correction of intestinal retention by whole-body profile activity of vitamin B 12-58 cobalt and by double tracer technique

International Nuclear Information System (INIS)

Goncalves, M.R. Bencke; Gheldof, R.; Paternot, L. van Tricht; Delmotte, E.; Verschaeren, A.; Martin, P.; Verhas, M.; Universidade Federal, Rio de Janeiro, RJ

1997-01-01

Full text. Intestinal retention could give false negative results in determining the whole-body retention of vitamin B 12 absorption (WBC B12-58Co). After having validate the WBC B12-58Co, taking the Schilling test as reference, we have studied the feasibility to evaluate the intestinal contamination by measurement of the profile activity distribution of vitamin B12-58Co and by a double tracer technique (WBC B12-58Co/ WBC 51 Cr Cl3). Methodology: twenty five patients were studied for the setting up of the new methodology. For eleven of them the WBC B12-58 Co retention was measured at the 7th day after the oral administration of 37KBq of B12-58Co using a four detectors whole body counter. One week later, a Schilling test was performed after the oral absorption of 18,5 KBq B12-57Co. Results were expressed as %ID. In these patients, one single peak of hepatic activity was observed on the whole body profile and thus no further intestinal correction was needed. In order to evaluate the intestinal contribution, we made in nine other patients the profile of the whole body distribution of activity at 1 h, 1 week and two weeks after the oral administration of B12-58Co. For five other patients a double tracer technique was used for intestinal correction after the simultaneous oral administration of 37 KBq of B12-58Co and 1,85 MBq of 51 Cr Cl3. The B12-58Co absorption was evaluated after intestinal correction based on subtraction of the 51Cr Cl3 contribution after the formula: B12-58Co(%ID) = WBC B12-58Co - WBC 51 Cr Cl3/1 - WBC 51 Cr Cl3. Results: the correlation with the Schilling test was found excellent: r=0,94 (n=11). The normality for WBC retention (n=7) was define as 53,2 +-12,4% ID (SD). For nine patients studied at the 7th day, the presence of a double peak (hepatic and intestinal peaks) allowed the subtraction by exponential extrapolation; the correction range was 4,4% to 37,2%. With the exception of one observation there was no difference in the measure of vitamin

Folic acid fortification: why not vitamin B12 also?

Science.gov (United States)

Selhub, Jacob; Paul, Ligi

2011-01-01

Folic acid fortification of cereal grains was introduced in many countries to prevent neural tube defect occurrence. The metabolism of folic acid and vitamin B12 intersect during the transfer of the methyl group from 5-methyltetrahydrofolate to homocysteine catalyzed by B12-dependent methioine synthase. Regeneration of tetrahydrofolate via this reaction makes it available for synthesis of nucleotide precursors. Thus either folate or vitamin B12 deficiency can result in impaired cell division and anemia. Exposure to extra folic acid through fortification may be detrimental to those with vitamin B12 deficiency. Among participants of National Health And Nutrition Examination Survey with low vitamin B12 status, high serum folate (>59 nmol/L) was associated with higher prevalence of anemia and cognitive impairment when compared with normal serum folate. We also observed an increase in the plasma concentrations of total homocysteine and methylmalonic acid (MMA), two functional indicators of vitamin B12 status, with increase in plasma folate under low vitamin B12 status. These data strongly imply that high plasma folate is associated with the exacerbation of both the biochemical and clinical status of vitamin B12 deficiency. Hence any food fortification policy that includes folic acid should also include vitamin B12. Copyright © 2011 International Union of Biochemistry and Molecular Biology, Inc.

Vitamin B12 supplementation during pregnancy and postpartum improves B12 status of both mothers and infants but vaccine response in mothers only: a randomized clinical trial in Bangladesh

Science.gov (United States)

Purpose Poor vitamin B12 (B12) status is associated with adverse outcomes in pregnancy and infancy. Little is known about effects of B12 supplementation on immune function. The present study aimed to evaluate effects of pre- and postnatal B12 supplementation on biomarkers of B12 status and vaccine-s...

Vitamin B12 in metformin-treated diabetic patients: a cross-sectional study in Brazil Vitamina B12 em pacientes diabéticos usando metformina: um corte transversal no Brasil

Directory of Open Access Journals (Sweden)

Monique Nervo

2011-02-01

Full Text Available OBJECTIVE: The objective of this study was to evaluate the presence of vitamin B12 deficiency and the factors associated with serum vitamin B12 levels in a sample of metformin-treated Brazilian diabetic patients. METHOD: Cross-sectional study. RESULTS: 144 patients were included. Serum vitamin B12 levels were low (OBJETIVO: O objetivo deste estudo foi avaliar a prevalência de deficiência de vitamina B12 em pacientes diabéticos brasileiros tratados com metformina e os fatores associados aos níveis séricos de vitamina B12. MÉTODO: Corte transversal. RESULTADOS: 144 pacientes foram incluídos. Os níveis séricos de vitamina B12 foram baixos (< 125 pmol/L em 10 pacientes (6,9% e possivelmente baixos (125 - 250pmol/L em 53 pacientes (36,8%. Os níveis séricos de vitamina B12 foram associados negativamente à idade (B = -3,17; β = -0,171; p = 0,037 e à duração do uso de metformina (B = -33,36; β= -0,161; p = 0,048 e positivamente com a ingestão estimada de vitamina B12 (B = 67,96; β = 0,249; p = 0,002. CONCLUSÃO: Estes resultados sugerem alta prevalência de deficiência de vitamina B12 em pacientes diabéticos tratados com metformina. Pacientes mais velhos, em uso de metformina há muito tempo e com ingestão baixa de vitamina B12 estão provavelmente mais predispostos a essa deficiência.

Electronographic calibration of UK 1.2-m Schmidt plates

International Nuclear Information System (INIS)

Hawkins, M.R.S.

1979-01-01

Two electronographic sequences are given in the South Galactic Pole region down to msub(B) = approximately 23 +- 0.3 mag. These sequences are used to obtain a calibration for COSMOS measures of UK 1.2-m Schmidt plates and evaluate their photometric transfer properties. (author)

Analytical electrochemistry of vitamin B12 on a bismuth-film electrode surface

International Nuclear Information System (INIS)

Kreft, Gabriel L.; Braga, Otoniel C. de; Spinelli, Almir

2012-01-01

Cyclic voltammetry (CV) and square wave adsorptive stripping voltammetry (SWAdSV) were used to investigate the performance of an ex situ plated bismuth-film electrode (BiFE) employed to study the electrochemical behavior and the electroanalytical determination of vitamin B 12 . Two pH-dependent reversible peaks were observed for the B 12r –B 12s (Co(II)–Co(I)) couple after pre-concentration of vitamin B 12 at −1.2 V for 30 s. An adsorption-controlled reaction rate with one electron involved in the electrochemical step was observed for the mechanism implicated. The calibration curve obtained in a Britton–Robinson solution at pH 12.0 was linear in the concentration range of 0.100–1.000 μmol L −1 (r = 0.9980). The detection limit was found to be 33.1 nmol L −1 . The electrode was successfully employed for the determination of vitamin B 12 in two pharmaceutical products. The electrode performance was compared with those of modified and unmodified electrodes as well as with the UV–vis spectrophotometric method.

Vitamin B12 transport from food to the body's cells--a sophisticated, multistep pathway

DEFF Research Database (Denmark)

Nielsen, Marianne J; Rasmussen, Mie R; Andersen, Christian B F

2012-01-01

Vitamin B(12) (B(12); also known as cobalamin) is a cofactor in many metabolic processes; deficiency of this vitamin is associated with megaloblastic anaemia and various neurological disorders. In contrast to many prokaryotes, humans and other mammals are unable to synthesize B(12). Instead...... in the transport pathway are also known culprits of functional B(12) deficiency. Biochemical and genetic approaches have identified novel proteins in the B(12) transport pathway--now known to involve more than 15 gene products--delineating a coherent pathway for B(12) trafficking from food to the body's cells...

Electron addition to alkyl cobalamins, coenzyme B/sub 12/ and vitamin B/sub 12/. [Gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Rao, D N.R.; Symons, M C.R. [Leicester Univ. (UK). Dept. of Chemistry

1983-01-01

Exposure of dilute solutions of methyl and ethyl cobalamins and coenzyme B/sub 12/ in dilute solutions (D/sub 2/O+CD/sub 3/OD) to /sup 60/Co ..gamma..-rays at 77 K gave a single broad feature in the free-spin region assigned to electron-capture species with the excess electron largely confined to a ..pi..* corrin orbital. On warming above 77 K the methyl derivative gave a novel species with spectral features characteristic of an unpaired electron in the Co(dsub(x/sup 2/-y/sup 2/)) orbital. The other two substrates gave spectra due to Cosup(II)Bsub(12r) both on warming and after photolyses with visible light. The acetyl derivative gave an electron-capture species whose e.s.r. spectrum was characteristic of an electron in the Co(dsub(z/sup 2/)) orbital, which on warming above 77 K changed to the normal Cosup(II)Bsub(12r) spectrum. The cyano derivative (vitamin B/sub 12/) gave electron addition into the Co(dsub(z/sup 2/)) orbital, as evidenced by the large hyperfine coupling to /sup 13/C from /sup 13/CN ligands. On annealing, cyanide ions were lost irreversibly, Bsub(12r) being detected by e.s.r. spectroscopy. In contrast, the dicyano derivative on electron addition at 77 K gave a species containing only one /sup 13/CN ligand. Hence in this case one CN/sup -/ ligand was lost at 77 K, with no return of the dimethylbenzimidazole ligand. These results are discussed in terms of a new mechanism for electron-addition to alkyl cobalamins.

Visualizing molecular juggling within a B[subscript 12]-dependent methyltransferase complex

Energy Technology Data Exchange (ETDEWEB)

Kung, Yan; Ando, Nozomi; Doukov, Tzanko I.; Blasiak, Leah C.; Bender, Güne; #351; ; Seravalli, Javier; Ragsdale, Stephen W.; Drennan, Catherine L. (MIT); (Michigan); (UNL)

2013-04-08

Derivatives of vitamin B{sub 12} are used in methyl group transfer in biological processes as diverse as methionine synthesis in humans and CO{sub 2} fixation in acetogenic bacteria. This seemingly straightforward reaction requires large, multimodular enzyme complexes that adopt multiple conformations to alternately activate, protect and perform catalysis on the reactive B{sub 12} cofactor. Crystal structures determined thus far have provided structural information for only fragments of these complexes, inspiring speculation about the overall protein assembly and conformational movements inherent to activity. Here we present X-ray crystal structures of a complete 220 kDa complex that contains all enzymes responsible for B{sub 12}-dependent methyl transfer, namely the corrinoid iron-sulphur protein and its methyltransferase from the model acetogen Moorella thermoacetica. These structures provide the first three-dimensional depiction of all protein modules required for the activation, protection and catalytic steps of B{sub 12}-dependent methyl transfer. In addition, the structures capture B{sub 12} at multiple locations between its 'resting' and catalytic positions, allowing visualization of the dramatic protein rearrangements that enable methyl transfer and identification of the trajectory for B{sub 12} movement within the large enzyme scaffold. The structures are also presented alongside in crystallo spectroscopic data, which confirm enzymatic activity within crystals and demonstrate the largest known conformational movements of proteins in a crystalline state. Taken together, this work provides a model for the molecular juggling that accompanies turnover and helps explain why such an elaborate protein framework is required for such a simple, yet biologically essential reaction.

Vitamin B12 deficiency presenting as an acute confusional state: a ...

African Journals Online (AJOL)

EB

2013-09-03

Sep 3, 2013 ... occurred following parenteral vitamin B12 replacement therapy. Conclusion: This case report highlights one of the neuro-psychiatric presentations of vitamin B12 deficiency .... and Occupational Health Abstract No:.

Simultaneous radiodetermination of folate and vitamin B12

International Nuclear Information System (INIS)

Gutcho, S.; Mansbach, L.

1978-01-01

The invention concerns a method to simultaneously investigate or determine folate and vitamin B12. The differentiation between both compounds is based on the use of radioactive tracers; a radio-iodized folic acid is used as folate tracer; vitamin B12 can be labelled with 57 Co. (VJ) [de

Magnetic Properties of New Triangular Lattice Magnets A${_4}$B'B${_2}$O$_{12}$

OpenAIRE

Rawl, Ryan; Lee, Minseong; Choi, Eun Sang; Li, Guang; Chen, Kuan-Wen; Baumbach, Ryan; Cruz, Clarina R. dela; Ma, Jie; Zhou, Haidong

2017-01-01

The geometrically frustrated two dimensional triangular lattice magnets A${_4}$B'B${_2}$O$_{12}$ (A = Ba, Sr, La; B' = Co, Ni, Mn; B = W, Re) have been studied by x-ray diffraction, AC and DC susceptibilities, powder neutron diffraction, and specific heat measurements. The results reveal that (i) the samples containing Co$^{2+}$ (effective spin-1/2) and Ni$^{2+}$ (spin-1) ions with small spin numbers exhibit ferromagnetic (FM) ordering while the sample containing Mn$^{2+}$ (spin-5/2) ions wit...

The distribution of total vitamin b12 holotranscobalamin and the active vitamin b12 fraction in the first 5 weeks postpartum

NARCIS (Netherlands)

van der Woude, D.A.A.; Pijnenborg, J.M.A.; de Vries, J.; van Wijk, E.M.

2018-01-01

Introduction Total vitamin B12 levels decrease significantly during pregnancy and recover to normal values within 8-week postpartum. Holotranscobalamin (holoTC) reflects the active part of vitamin B12 and has been shown to remain constant during pregnancy and postpartum. A mechanism of

Interleukin 12B (IL12B) Genetic Variation and Pulmonary Tuberculosis: A Study of Cohorts from The Gambia, Guinea-Bissau, United States and Argentina

DEFF Research Database (Denmark)

Morris, Gerard A J; Edwards, Digna R Velez; Hill, Philip C

2011-01-01

We examined whether polymorphisms in interleukin-12B (IL12B) associate with susceptibility to pulmonary tuberculosis (PTB) in two West African populations (from The Gambia and Guinea-Bissau) and in two independent populations from North and South America. Nine polymorphisms (seven SNPs, one...

Vitamin B12 deficiency presenting as an acute confusional state: A ...

African Journals Online (AJOL)

Results: We report a case of a 44 year old female patient referred to the haematology unit with vitamin B12 deficiency presenting as an acute confusional state or delirium. Total resolution of the psychiatric symptoms occurred following parenteral vitamin B12 replacement therapy. Conclusion: This case report highlights one ...

12 CFR Appendixes A-B to Part 41 - [Reserved

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 1 2010-01-01 2010-01-01 false [Reserved] A Appendixes A-B to Part 41 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY FAIR CREDIT REPORTING Appendixes A-B to Part 41 [Reserved] ...

[Folate, vitamin B12 and human health].

Science.gov (United States)

Brito, Alex; Hertrampf, Eva; Olivares, Manuel; Gaitán, Diego; Sánchez, Hugo; Allen, Lindsay H; Uauy, Ricardo

2012-11-01

During the past decade the role of folate and vitamin B12 in human nutrition have been under constant re-examination. Basic knowledge on the metabolism and interactions between these essential nutrients has expanded and multiple complexities have been unraveled. These micronutrients have shared functions and intertwined metabolic pathways that define the size of the "methyl donor" pool utilized in multiple metabolic pathways; these include DNA methylation and synthesis of nucleic acids. In Chile, folate deficiency is virtually nonexistent, while vitamin B12 deficiency affects approximately 8.5-51% depending on the cut-off value used to define deficiency. Folate is found naturally mainly in vegetables or added as folic acid to staple foods. Vitamin B12 in its natural form is present only in foods of animal origin, which is why deficit is more common among strict vegetarians and populations with a low intake of animal foods. Poor folate status in vulnerable women of childbearing age increases the risk of neural tube birth defects, so the critical time for the contribution of folic acid is several months before conception since neural tube closure occurs during the first weeks of life. The absorption of vitamin B12 from food is lower in older adults, who are considered to have higher risk of gastric mucosa atrophy, altered production of intrinsic factor and acid secretion. Deficiency of these vitamins is associated with hematological disorders. Vitamin B12 deficiency can also induce clinical and sub-clinical neurological and of other disorders. The purpose of this review is to provide an update on recent advances in the basic and applied knowledge of these vitamins relative to human health.

Lhermitte's sign and vitamin B12 deficiency: case report

OpenAIRE

Teive, Hélio Afonso Ghizoni; Haratz, Salo; Zavala, Jorge; Munhoz, Renato Puppi; Scola, Rosana Hermínia; Werneck, Lineu César

2009-01-01

CONTEXT AND OBJECTIVE: Lhermitte's sign, a classical neurological sign, is a rare manifestation of vitamin B12 deficiency. The aim here was to report on a case of an elderly patient with vitamin B12 deficiency whose first clinical manifestation was the presence of Lhermitte's sign. CASE REPORT: We describe an elderly patient with vitamin B12 deficiency who presented cognitive dysfunction, peripheral polyneuropathy and sensory ataxia, and whose first clinical manifestation was the presence of ...

Production Of Vitamin B 12 By Streptomyces Fulvissimus | Atta ...

African Journals Online (AJOL)

Fifty five of actinomycete isolates were screened for vitamin B12 production by growing on soybean meal medium fortified with cobalt. Only one AZ-Z-88 among nine actinomycete cultures was found to produce significantly higher yield of the vitamin B12 (64.57 ug/ml). Determination of vitamin B12 production was carried out ...

Vitamin B12 in metformin-treated diabetic patients: a cross-sectional study in Brazil Vitamina B12 em pacientes diabéticos usando metformina: um corte transversal no Brasil

OpenAIRE

Monique Nervo; Adriano Lubini; Fabiana Viegas Raimundo; Gustavo Adolpho Moreira Faulhaber; Carine Leite; Leonardo Moura Fischer; Tania Weber Furlanetto

2011-01-01

OBJECTIVE: The objective of this study was to evaluate the presence of vitamin B12 deficiency and the factors associated with serum vitamin B12 levels in a sample of metformin-treated Brazilian diabetic patients. METHOD: Cross-sectional study. RESULTS: 144 patients were included. Serum vitamin B12 levels were low (< 125 pmol/L) in 10 patients (6.9%) and possibly low (125 - 250 pmol/L) in 53 patients (36.8%). Serum vitamin B12 levels were negatively associated with age (B = -3.17; β= -0.1...

A Computational Tale of Two Enzymes: Glycerol Dehydration With or Without B12.

Science.gov (United States)

Kovačević, Borislav; Barić, Danijela; Babic, Darko; Bilić, Luka; Hanževački, Marko; Sandala, Gregory M; Radom, Leo; Smith, David M

2018-06-12

We present a series of QM/MM calculations aimed at understanding the mechanism of the biological dehydration of glycerol. Strikingly and unusually, this process is catalyzed by two different radical enzymes, one of which is a coenzyme-B 12 - dependent enzyme and the other which is a coenzyme-B 12 - independent enzyme. We show that glycerol dehydration in the presence of the coenzyme-B 12 -dependent enzyme proceeds via a 1,2-OH shift, which benefits from a significant catalytic reduction in the barrier. In contrast, the same reaction in the presence of the coenzyme-B 12 -independent enzyme is unlikely to involve the 1,2-OH shift; instead, a strong preference for direct loss of water from a radical intermediate is indicated. We show that this preference and, ultimately the evolution of such enzymes, is strongly linked with the reactivities of the species responsible for abstracting a hydrogen atom from the substrate. It appears that the hydrogen re-abstraction step involving the product-related radical is fundamental to the mechanistic preference. The unconventional 1,2-OH shift seems to be required to generate a product-related radical of sufficient reactivity to cleave the relatively inactive C-H bond arising from the B 12 cofactor. In the absence of B 12 , it is the relatively weak S-H bond of a cysteine residue that must be homolyzed. Such a transformation is much less demanding and its inclusion apparently enables a simpler overall dehydration mechanism.

Vegan diet, subnormal vitamin B-12 status and cardiovascular health.

Science.gov (United States)

Woo, Kam S; Kwok, Timothy C Y; Celermajer, David S

2014-08-19

Vegetarian diets have been associated with atherosclerosis protection, with healthier atherosclerosis risk profiles, as well as lower prevalence of, and mortality from, ischemic heart disease and stroke. However, there are few data concerning the possible cardiovascular effects of a vegan diet (with no meat, dairy or egg products). Vitamin B-12 deficiency is highly prevalent in vegetarians; this can be partially alleviated by taking dairy/egg products in lact-ovo-vegetarians. However, metabolic vitamin B-12 deficiency is highly prevalent in vegetarians in Australia, Germany, Italy and Austria, and in vegans (80%) in Hong Kong and India, where vegans rarely take vitamin B-12 fortified food or vitamin B-12 supplements. Similar deficiencies exist in northern Chinese rural communities consuming inadequate meat, egg or dairy products due to poverty or dietary habits. Vascular studies have demonstrated impaired arterial endothelial function and increased carotid intima-media thickness as atherosclerosis surrogates in such metabolic vitamin B-12 deficient populations, but not in lactovegetarians in China. Vitamin B-12 supplementation has a favourable impact on these vascular surrogates in Hong Kong vegans and in underprivileged communities in northern rural China. Regular monitoring of vitamin B-12 status is thus potentially beneficial for early detection and treatment of metabolic vitamin B-12 deficiency in vegans, and possibly for prevention of atherosclerosis-related diseases.

Vegan Diet, Subnormal Vitamin B-12 Status and Cardiovascular Health

Directory of Open Access Journals (Sweden)

Kam S. Woo

2014-08-01

Full Text Available Vegetarian diets have been associated with atherosclerosis protection, with healthier atherosclerosis risk profiles, as well as lower prevalence of, and mortality from, ischemic heart disease and stroke. However, there are few data concerning the possible cardiovascular effects of a vegan diet (with no meat, dairy or egg products. Vitamin B-12 deficiency is highly prevalent in vegetarians; this can be partially alleviated by taking dairy/egg products in lact-ovo-vegetarians. However, metabolic vitamin B-12 deficiency is highly prevalent in vegetarians in Australia, Germany, Italy and Austria, and in vegans (80% in Hong Kong and India, where vegans rarely take vitamin B-12 fortified food or vitamin B-12 supplements. Similar deficiencies exist in northern Chinese rural communities consuming inadequate meat, egg or dairy products due to poverty or dietary habits. Vascular studies have demonstrated impaired arterial endothelial function and increased carotid intima-media thickness as atherosclerosis surrogates in such metabolic vitamin B-12 deficient populations, but not in lactovegetarians in China. Vitamin B-12 supplementation has a favourable impact on these vascular surrogates in Hong Kong vegans and in underprivileged communities in northern rural China. Regular monitoring of vitamin B-12 status is thus potentially beneficial for early detection and treatment of metabolic vitamin B-12 deficiency in vegans, and possibly for prevention of atherosclerosis-related diseases.

Vitamin B12 Deficiency Presenting as Pancytopenia in Pregnancy: A Case Report

Directory of Open Access Journals (Sweden)

Idris N

2012-12-01

Full Text Available Vitamin B12 deficiency is a well-known cause of megaloblastic anaemia and pancytopenia. However, the incidence in pregnancy is rarely reported. We present a case of a 32-year old multigravid woman who was diagnosed with megaloblastic anaemia since 22 weeks gestation and progressed to develop severe pancytopenia at 30 weeks gestation. she was also diagnosed with vitamin B12 deficiency related to dietary and sociocultural habits. Folate and iron levels were normal throughout pregnancy. treatment with parenteral cyano-cobalamin resulted in sustained improvement of haematological parameters. the pregnancy was carried to term and the baby was born weighing 2,050gm but otherwise well at birth and had normal developmental milestones thereafter. this case illustrates the clinical presentation of maternal vitamin B12 deficiency and demonstrates the importance of detecting and treating maternal vitamin B12 deficiency during pregnancy in at-risk patients. Failure to diagnose and institute treatment carries significant risks to both mother and child. oral vitamin B12 supplementation should be considered for patients who are strict vegetarians or consume very little animal products.

Administrative Circulars No. 12 A (Rev. 2) - "Education fees” and No. 12 B (Rev. 2) - “Education fees and language courses”

CERN Multimedia

2013-01-01

Administrative Circulars No. 12 A (Rev. 2) entitled “Education fees” and No. 12 B (Rev. 2) entitled “Education fees and language courses”, approved by the Director-General following discussion at the Standing Concertation Committee meeting of 27 June 2013 and entering into force on 1 August 2013, are available on the intranet site of the Human Resources Department (see here).   Administrative Circular No. 12 A (Rev. 2) is applicable to Staff Members (except former “Local Staff Members”) recruited before 1st January 2007. Administrative Circular No. 12 B (Rev. 2) is applicable to Staff Members recruited on or after 1st January 2007, to Fellows, to Scientific Associates, to Guest Professors and to former “Local Staff” recruited before 1st January 2007. They cancel and replace Administrative Circulars No. 12 A (Rev. 1/Corr.) entitled "Education fees” and No. 12 B (Rev. 1/Corr.) entitled “Edu...

Vitamin B-12 supplementation of rural Mexican women changes biochemical B-12 status indicators but does not affect hematology or a bone turnover marker

Science.gov (United States)

Based on the high prevalence of low serum vitamin B-12 concentrations and low dietary intake of the vitamin in Latin American studies including research in Mexico, it appears that vitamin B-12 deficiency is common. Whether this is associated with adverse effects on human function is unknown. To eval...

Vitamin B12 status and the effects of vitamin B12 supplementation during the first year of life of spring calves from pasture-fed dairy herds.

Science.gov (United States)

Grace, N D; Knowles, S O; Nortjé, R

2014-09-01

To determine the vitamin B12 status of dairy calves during their first year of life, and to evaluate the benefits of vitamin B12 supplementation. In Experiment I, 20 17-day-old heifer calves from the AgResearch Flock House herd were monitored until 198 days old. On Days 0 and 90 of the study, half of the animals received an injection of microencapsulated vitamin B12 at 0.12 mg/kg bodyweight. All received colostrum, milk replacer and calf meal, with ad libitum access to pasture. At regular intervals the calves were weighed and serum collected for vitamin B12 measurement. In Experiment II at Flock House and the adjacent Landcorp Tangimoana station, 80 150-day-old heifer calves were monitored until 342 days old. On Days 0 and 97, half of the animals received vitamin B12 as per Experiment I. At regular intervals samples were collected from 12 calves per group, to determine concentrations of vitamin B12 in serum. Mean concentration of vitamin B12 in milk replacer was 63 (SE 4) µg/kg dry matter (DM). Cobalt concentrations in calf meal were 0.45-1.58 and 0.07-0.28 mg/kg DM in pastures. From 17 to 198 days of age (Experiment I) mean concentrations of vitamin B12 in serum of the control group decreased from 119 (SE 8) to 57 (SE 5) pmol/L. From 150 to 342 days of age (Experiment II), overall mean concentrations of the control groups at Flock House and Tangimoana were 90 (SE 2) and 96 (SE 3) pmol/L, respectively. Vitamin B12 injections increased (ppasture-based diet. Supplementation increased concentrations of vitamin B12 in serum but did not improve liveweight gains. Under this calf rearing system, vitamin B12 deficiency is unlikely to occur prior to weaning, and vitamin B12 supplementation is unlikely to increase growth rates of grazing calves when concentrations of vitamin B12 in serum are > 90 pmol/L.

Vitamin B12 deficiency anemia

Science.gov (United States)

... diet Poor diet in infants Poor nutrition during pregnancy Certain health conditions can make it difficult for your body to absorb enough vitamin B12. They include: Chronic alcoholism Crohn disease, celiac disease, infection with the fish ...

[Vitamin B12 Deficiency in Type 2 Diabetes Mellitus].

Science.gov (United States)

Tavares Bello, Carlos; Capitão, Ricardo Miguel; Sequeira Duarte, João; Azinheira, Jorge; Vasconcelos, Carlos

2017-10-31

Type 2 diabetes mellitus is a common disease, affecting up to 13.1% of the Portuguese population. In addition to the known micro and macrovascular complications, drug side effects constitute a major concern, leading to changes in the treatment guidelines, which favor safety over efficacy. Metformin is the first-line pharmacological treatment for most patients with type 2 diabetes mellitus; however, it has been associated with vitamin B12 deficiency in up to 30% of treated patients. The authors describe the prevalence of vitamin B12 deficiency in a diabetic population and explore the possible underlying factors. Retrospective, observational study. Clinical and laboratory data of type 2 diabetes mellitus patients whose vitamin B12 status was evaluated in the last decade (2005 - 2016) were analyzed. Patients with known malabsorptive syndromes or having undergone bariatric surgery were excluded from the study. Statistical analysis of the data was done and the results were considered statistically significant at p values 2.2 years and 11 ± 10.4 years of type 2 diabetes mellitus duration. These patients had a high prevalence of complications: diabetic renal disease 47.7%, neuropathy 9.2%, retinopathy 14.9%, coronary artery disease 8.4%, cerebrovascular disease 10.9%, and peripheral arterial disease 5.5%. Vitamin B12 deficiency (21.4% of the population and this subgroup was older (68.4 vs 65.8 years, p = 0.006), had a longer type 2 diabetes mellitus duration (13.35 vs 10.36 years; p = 0.001), higher prevalence of retinopathy (20.9% vs 13.3%; p = 0.005) and thyroid dysfunction (34% vs 23.7%; p = 0.002). Vitamin B12 deficiency was also more frequent in patients treated with metformin (24.7% vs 15.8%; p = 0.017), antiplatelet agents (25.4% vs 16.2%, p 26.8% vs 18.2%; p = 0.001). After adjustment for possible confounders, the variables associated with B12 deficiency were: metformin, hypothyroidism, age and type 2 diabetes mellitus duration. Despite the retrospective design

Voltammetry of Vitamin B12 on a thin self-assembled monolayer modified electrode

International Nuclear Information System (INIS)

Yang Nianjun; Wan Qijin; Wang, Xiaoxia

2005-01-01

Vitamin B 12 showed three reduction waves at a thin self-assembled monolayer of mercaptoacetic acid modified gold electrode at 0.21, 0.16, -0.41 V in a 0.01 mol l -1 HCl solution at a scan rate of 100 mV s -1 . The overall electrode reaction followed an ECE mechanism, leading to a total two-electron exchange. The predominant Co(III) form was reduced directly at 0.21 V by a one-electron transfer accomplished by CN - cleavage into the cyanocob(II)alamin. The latter species then equilibrated with the base-off B 12r , which was immediately reduced into B 12s at 0.16 V. The wave at -0.41 V might be a catalytic hydrogen wave. The cathodic peak currents at 0.21 V were controlled by the diffusion of Vitamin B 12 . On the base of its diffusion behavior, the semi-derivate voltammetric method for the detection of Vitamin B 12 was presented. The semi-derivate voltammetric peak current of the wave at 0.21 V was linear with the content of Vitamin B 12 in the range of 4.0 x 10 -9 to 4.0 x 10 -5 mol l -1 . The detection limit was 1.0 x 10 -9 mol l -1 . The proposed method was applied successfully to determine the content of Vitamin B 12 in pharmaceutical preparations

True Polar Wander and Hotspot Fixity: A Paleomagnetic Investigation of the Skewness of Magnetic Anomaly 12r (32 Ma B.P.) on the Pacific Plate

Science.gov (United States)

Gordon, R. G.; Horner-Johnson, B. C.

2010-12-01

Prior studies have shown that Pacific hotspots and Indo-Atlantic hotspots have moved in approximate unison relative to the spin axis since 65 Ma B.P. [Morgan, 1981; Gordon and Cape, 1981; Gordon, 1982] and since 56 Ma B.P. [Petronotis et al., 1994], which is most simply interpreted as true polar wander. In contrast, Pacific hotspots and Indo-Atlantic hotspots give conflicting results for 72 Ma B.P. and for 81 Ma B.P., which may indicate motion between Pacific hotspots and Indo-Atlantic hotspots [Tarduno and Cottrell, 1997; Petronotis et al., 1999; Tarduno et al., 2003]. Thus it is important to estimate Pacific plate apparent polar wander (APW) for more time intervals. From such estimates the APW of Pacific hotspots can be inferred and compared with that of Indo-Atlantic hotspots [e.g., Besse and Courtillot 2002]. Here we present a study of the skewness of anomaly 12r between the Galapagos and Clipperton and between the Clipperton and Clarion fracture zones. We chose this region for several reasons: First, numerical experiments, like those conducted by Acton and Gordon [1991], indicate that magnetic profiles between the Galapagos and Clarion fracture zones should contain the most information about the Pacific plate paleomagnetic pole for chron C12r (32 Ma B.P.). Second, in these two spreading rate corridors, spreading half rates range from 72 to 86 mm/a and therefore have negligible anomalous skewness, given that they exceed ≈50 mm/a [Roest et al., 1992; Dyment et al. 1994]. Third, vector aeromagnetic profiles are available for analysis. One of the challenges to interpreting magnetic anomalies in low latitudes where the anomalies strike nearly north-south is the very low amplitude of the signal relative to the noise, the latter of which can be especially intense near the present magnetic equator due to the amplification of diurnal variation by the equatorial electrojet. Previously we showed that vector aeromagnetic profiles record low-latitude Pacific plate

Folato, vitamina B12 e ferritina sérica e defeitos do tubo neural Folate, vitamin B12, serum ferritin and defects of the neural tube

Directory of Open Access Journals (Sweden)

Gizele Thame

1998-09-01

Full Text Available Objetivo: verificar os níveis de folatos, vitamina B12 e ferritina em pacientes cujos fetos apresentaram defeitos de tubo neural (DTN. O folato sangüíneo e a vitamina B12 atuam como cofatores para as enzimas envolvidas na biossíntese do DNA. A interrupção deste processo pode impedir o fechamento do tubo neural. A suplementação vitamínica contendo folato pode reduzir as taxas de ocorrência de defeitos de tubo neural, embora exista a preocupação de que esta prevenção possa mascarar a deficiência de vitamina B12. Métodos: dosagens de vitamina B12 e ferritina pelo método de enzimaimunoensaio com micropartículas e a dosagens de ácido fólico pelo método de captura iônica (IMx ABBOTT. Resultados: a porcentagem de gestantes com deficiência de vitamina B12 (níveis séricos Purpose: to determine folate, vitamin B12 and ferritin levels in patients whose fetuses presented neural-tube defects (NTD. Blood folate and vitamin B12 act as cofactors of enzymes involved in DNA biosynthesis. Interruption of this process may block neural-tube closing. Vitamin supplementation with folate may reduce occurrence rates and recurrence of NTD, although there is concern about the fact that this prevention may mask vitamin B12 deficiency. Methods: vitamin B12 and ferritin determinations by enzyme immunoassay with microparticles and folic acid determination using the ion capture method (IMx ABBOTT. Results: the percentage of pregnant women with vitamin B12 deficirncy (serum levels < 150 pg/ml was 11.8%. There was no case of folate deficiency (serum levels < 3.0 ng/ml and prevalence of pregnant women with iron store deficiency was 47.1% (serum levels < ng/mg. Conclusions: occording to the results obtained in this study (prevalence of 11.8% of vitamin B12 and 0% of folate deficient pregnant women we suggest that supplementation should be administered after serum vitamin B12 determination.

Vitamin B12 deficiency: Characterization of psychometrics and MRI morphometrics.

Science.gov (United States)

Hsu, Yen-Hsuan; Huang, Ching-Feng; Lo, Chung-Ping; Wang, Tzu-Lan; Tu, Min-Chien

2016-01-01

Vitamin B12 is essential for the integrity of the central nervous system. However, performances in different cognitive domains relevant to vitamin B12 deficiency remain to be detailed. To date, there have been limited studies that examined the relationships between cognitions and structural neuroimaging in a single cohort of low-vitamin B12 status. The present study aimed to depict psychometrics and magnetic resonance imaging (MRI) morphometrics among patients with vitamin B12 deficiency, and to examine their inter-relations. We compared 34 consecutive patients with vitamin B12 deficiency (serum level ≤ 250 pg/ml) to 34 demographically matched controls by their cognitive performances and morphometric indices of brain MRI. The correlations between psychometrics and morphometrics were analyzed. The vitamin B12 deficiency group had lower scores than the controls on total scores of Mini-Mental Status Examination (MMSE) and Cognitive Abilities Screening Instrument (CASI) (both P psychometric and morphometric indices, pronounced correlations between bicaudate ratio and long-term memory, mental manipulation, orientation, language, and verbal fluency were noted (all P < 0.01). Vitamin B12 deficiency is associated with a global cognition decline with language, orientation, and mental manipulation selectively impaired. Preferential atrophy in frontal regions is the main neuroimaging feature. Although the frontal ratio highlights the relevant atrophy among patients, the bicaudate ratio might be the best index on the basis of its strong association with global cognition and related cognitive domains, implying dysfunction of fronto-subcortical circuits as the fundamental pathogenesis related to vitamin B12 deficiency.

Vegetarer har høj risiko for at få B12-vitaminmangel

DEFF Research Database (Denmark)

Javid, Parva; Christensen, Erik

2016-01-01

Since vegetarians have a lower intake of vitamin B12 (B12) than non-vegetarians, they are at increased risk of developing B12 deficiency. The less animal products the food contains the worse the B12 status. However, even lacto-ovo-vegetarians run the risk of becoming deficient in B12. Vegetarians...... are recommended regularly to take supplements of B12, and they should be informed of the lacking content of B12 of plant products and the hazards of B12 deficiency. Furthermore, vegetarians should routinely be checked for possible B12 deficiency....

Malabsorption of protein bound vitamin B12.

OpenAIRE

Dawson, D W; Sawers, A H; Sharma, R K

1984-01-01

Patients with subnormal serum vitamin B12 concentrations were tested for absorption of protein bound vitamin B12 and compared with controls. Absorption of the protein bound vitamin appeared to decrease with increasing age in healthy subjects. Differences between the result of this test and the result of the Schilling test in patients who had undergone gastric surgery were confirmed; such differences were also seen in some patients who had iron deficiency anaemia, an excessive alcohol intake, ...

12 CFR 269b.731 - Signature.

Science.gov (United States)

2010-01-01

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Therapeutic role of Vitamin B12 in patients of chronic tinnitus: A pilot study

Directory of Open Access Journals (Sweden)

Charu Singh

2016-01-01

Full Text Available True tinnitus is a phantom auditory perception arising from a source or trigger in the cochlea, brainstem, or at higher centers and has no detectable acoustic generator. The most accepted is the famous neurophysiologic model of Jastreboff, which stresses that tinnitus, is a subcortical perception and results from the processing of weak neural activity in the periphery. The aim of this study is to determine the role of Vitamin B12 in treatment of chronic tinnitus. In this randomized, double-blind pilot study, total 40 patients were enrolled, of which 20 in Group A (cases received intramuscular therapy of 1 ml Vitamin B12 (2500 mcg weekly for a period of 6 weeks and Group B (20 patients received placebo isotonic saline 01 ml intramuscular. The patients were subjected to Vitamin B12 assay and audiometry pre- and post-therapy. Of the total patients of tinnitus, 17 were Vitamin B12 deficient that is 42.5% showed deficiency when the normal levels were considered to be 250 pg/ml. A paired t-test showed that in Group A, patients with Vitamin B12 deficiency showed significant improvement in mean tinnitus severity index score and visual analog scale (VAS after Vitamin B12 therapy. This pilot study highlights the significant prevalence of Vitamin B12 deficiency in North Indian population and improvement in tinnitus severity scores and VAS in cobalamin-deficient patients receiving intramuscular Vitamin B12 weekly for 6 weeks further provides a link between cobalamin deficiency and tinnitus thereby suggestive of a therapeutic role of B12 in cobalamin-deficient patients of tinnitus.

Therapeutic role of Vitamin B12 in patients of chronic tinnitus: A pilot study.

Science.gov (United States)

Singh, Charu; Kawatra, Rahul; Gupta, Jaya; Awasthi, Vishnu; Dungana, Homnath

2016-01-01

True tinnitus is a phantom auditory perception arising from a source or trigger in the cochlea, brainstem, or at higher centers and has no detectable acoustic generator. The most accepted is the famous neurophysiologic model of Jastreboff, which stresses that tinnitus, is a subcortical perception and results from the processing of weak neural activity in the periphery. The aim of this study is to determine the role of Vitamin B12 in treatment of chronic tinnitus. In this randomized, double-blind pilot study, total 40 patients were enrolled, of which 20 in Group A (cases) received intramuscular therapy of 1 ml Vitamin B12 (2500 mcg) weekly for a period of 6 weeks and Group B (20) patients received placebo isotonic saline 01 ml intramuscular. The patients were subjected to Vitamin B12 assay and audiometry pre- and post-therapy. Of the total patients of tinnitus, 17 were Vitamin B12 deficient that is 42.5% showed deficiency when the normal levels were considered to be 250 pg/ml. A paired t-test showed that in Group A, patients with Vitamin B12 deficiency showed significant improvement in mean tinnitus severity index score and visual analog scale (VAS) after Vitamin B12 therapy. This pilot study highlights the significant prevalence of Vitamin B12 deficiency in North Indian population and improvement in tinnitus severity scores and VAS in cobalamin-deficient patients receiving intramuscular Vitamin B12 weekly for 6 weeks further provides a link between cobalamin deficiency and tinnitus thereby suggestive of a therapeutic role of B12 in cobalamin-deficient patients of tinnitus.

Vitamin B12-catalyzed synthesis of some peracetylated alkyl b-D-xylopyranosides

Directory of Open Access Journals (Sweden)

LJILJANA STEVANOVIC

2003-10-01

Full Text Available The vitamin B12-catalyzed glycosylation reaction of brominated b-D-xylose peracetate with alkanols ROH (C1-C8 has been studied. The catalytically active species in this reaction was cob(Ialamin, obtained by chemical reduction of Vitamin B12 with NaBH4 (Co(III to Co(I. The reaction was carried out with 2 mol% of vitamin B12, with respect to xylosyl bromide 1, under argon at room temperature. Under these conditions, peracetylated C1-C8-alkyl b-D-xylopyranosides (3a–3f were obtained in moderate yield (55–70 %. In all cases 3,4-di-O-acetyl-D-xylal (4 was obtained, as the product of reductive elimination of peracetylated xylosyl bromide (15–25 %.

Integral measurement of the $^{12}$C(n,p)$^{12}$B reaction up to 10 GeV

CERN Document Server

Žugec, P; Bosnar, D; Ventura, A; Mengoni, A; Altstadt, S; Andrzejewski, J; Audouin, L; Barbagallo, M; Bécares, V; Bečvář, F; Belloni, F; Berthoumieux, E; Billowes, J; Boccone, V; Brugger, M; Calviani, M; Calviño, F; Cano-Ott, D; Carrapiço, C; Cerutti, F; Chiaveri, E; Chin, M; Cortés, G; Cortés-Giraldo, M.A; Cosentino, L; Diakaki, M; Domingo-Pardo, C; Dressler, R; Duran, I; Eleftheriadis, C; Ferrari, A; Finocchiaro, P; Fraval, K; Ganesan, S; García, A R; Giubrone, G; Gómez-Hornillos, M B; Gonçalves, I F; González-Romero, E; Griesmayer, E; Guerrero, C; Gunsing, F; Gurusamy, P; Heinitz, S; Jenkins, D G; Jericha, E; Käppeler, F; Karadimos, D; Kivel, N; Kokkoris, M; Krtička, M; Kroll, J; Langer, C; Lederer, C; Leeb, H; Leong, L S; Meo, S Lo; Losito, R; Manousos, A; Marganiec, J; Martínez, T; Massimi, C; Mastinu, P; Mastromarco, M; Mendoza, E; Milazzo, P M; Mingrone, F; Mirea, M; Mondalaers, W; Musumarra, A; Paradela, C; Pavlik, A; Perkowski, J; Plompen, A; Praena, J; Quesada, J; Rauscher, T; Reifarth, R; Riego, A; Roman, F; Rubbia, C; Sarmento, R; Saxena, A; Schillebeeckx, P; Schmidt, S; Schumann, D; Tagliente, G; Tain, J L; Tarrío, D; Tassan-Got, L; Tsinganis, A; Valenta, S; Vannini, G; Variale, V; Vaz, P; Versaci, R; Vermeulen, M J; Vlachoudis, V; Vlastou, R; Wallner, A; Ware, T; Weigand, M; Weiß, C; Wright, T

2016-01-01

The integral measurement of the $^{12}$C(n,p)$^{12}$B reaction was performed at the neutron time of flight facility n_TOF at CERN. The total number of $^{12}$B nuclei produced per neutron pulse of the n_TOF beam was determined using the activation technique in combination with a time of flight technique. The cross section is integrated over the n_TOF neutron energy spectrum from reaction threshold at 13.6 MeV to 10 GeV. Having been measured up to 1 GeV on basis of the $^{235}$U(n,f) reaction, the neutron energy spectrum above 200 MeV has been reevaluated due to the recent extension of the cross section reference for this particular reaction, which is otherwise considered a standard up to 200 MeV. The results from the dedicated GEANT4 simulations have been used to evaluate the neutron flux from 1 GeV up to 10 GeV. The experimental results related to the $^{12}$C(n,p)$^{12}$B reaction are compared with the evaluated cross sections from major libraries and with the predictions of different GEANT4 models, which m...

17 CFR 12.12 - Signature.

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2010-04-01

... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Signature. 12.12 Section 12.12... General Information and Preliminary Consideration of Pleadings § 12.12 Signature. (a) By whom. All... document on behalf of another person. (b) Effect. The signature on any document of any person acting either...

Is vitamin B12 deficiency a risk factor for cardiovascular disease in vegetarians?

Science.gov (United States)

Pawlak, Roman

2015-06-01

The goal of this paper is to describe the role of vitamin B12 deficiency in cardiovascular disease development among vegetarians. Vegetarians have a high prevalence of vitamin B12 deficiency. Deficiency of this vitamin is associated with a variety of atherogenic processes that are mainly, but not exclusively, due to vitamin B12 deficiency-induced hyperhomocysteinemia. Each 5-μmol/L increase above 10 μmol/L of serum homocysteine is associated with a 20% increased risk of circulatory health problems. Mean homocysteine concentration >10 μmol/L among vegetarians was reported in 32 of 34 reports. Macrocytosis associated with vitamin B12 deficiency is also associated with fatal and non-fatal coronary disease, myocardial infarction, stroke, and other circulatory health problems. Compared with non-vegetarians, vegetarians have an improved profile of the traditional cardiovascular disease risk factors, including serum lipids, blood pressure, serum glucose concentration, and weight status. However, not all studies that assessed cardiovascular disease incidence among vegetarians reported a protective effect. Among studies that did show a lower prevalence of circulatory health problems, the effect was not as pronounced as expected, which may be a result of poor vitamin B12 status due to a vegetarian diet. Vitamin B12 deficiency may negate the cardiovascular disease prevention benefits of vegetarian diets. In order to further reduce the risk of cardiovascular disease, vegetarians should be advised to use vitamin B12 supplements. Copyright © 2015 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

TMPRSS12 Is an Activating Protease for Subtype B Avian Metapneumovirus.

Science.gov (United States)

Yun, Bingling; Zhang, Yao; Liu, Yongzhen; Guan, Xiaolu; Wang, Yongqiang; Qi, Xiaole; Cui, Hongyu; Liu, Changjun; Zhang, Yanping; Gao, Honglei; Gao, Li; Li, Kai; Gao, Yulong; Wang, Xiaomei

2016-12-15

The entry of avian metapneumovirus (aMPV) into host cells initially requires the fusion of viral and cell membranes, which is exclusively mediated by fusion (F) protein. Proteolysis of aMPV F protein by endogenous proteases of host cells allows F protein to induce membrane fusion; however, these proteases have not been identified. Here, we provide the first evidence that the transmembrane serine protease TMPRSS12 facilitates the cleavage of subtype B aMPV (aMPV/B) F protein. We found that overexpression of TMPRSS12 enhanced aMPV/B F protein cleavage, F protein fusogenicity, and viral replication. Subsequently, knockdown of TMPRSS12 with specific small interfering RNAs (siRNAs) reduced aMPV/B F protein cleavage, F protein fusogenicity, and viral replication. We also found a cleavage motif in the aMPV/B F protein (amino acids 100 and 101) that was recognized by TMPRSS12. The histidine, aspartic acid, and serine residue (HDS) triad of TMPRSS12 was shown to be essential for the proteolysis of aMPV/B F protein via mutation analysis. Notably, we observed TMPRSS12 mRNA expression in target organs of aMPV/B in chickens. Overall, our results indicate that TMPRSS12 is crucial for aMPV/B F protein proteolysis and aMPV/B infectivity and that TMPRSS12 may serve as a target for novel therapeutics and prophylactics for aMPV. Proteolysis of the aMPV F protein is a prerequisite for F protein-mediated membrane fusion of virus and cell and for aMPV infection; however, the proteases used in vitro and vivo are not clear. A combination of analyses, including overexpression, knockdown, and mutation methods, demonstrated that the transmembrane serine protease TMPRSS12 facilitated cleavage of subtype B aMPV (aMPV/B) F protein. Importantly, we located the motif in the aMPV/B F protein recognized by TMPRSS12 and the catalytic triad in TMPRSS12 that facilitated proteolysis of the aMPV/B F protein. This is the first report on TMPRSS12 as a protease for proteolysis of viral envelope

Beta-decay asymmetries in polarized /sup 12/B and /sup 12/N, and the G-parity nonconservation

Energy Technology Data Exchange (ETDEWEB)

Sugimoto, K; Tanihata, I [Osaka Univ., Toyonaka (Japan). Lab. of Nuclear Studies

1976-10-01

The decay asymmetries (A) in polarized /sup 12/B and /sup 12/N have been measured as a function of ..beta..-ray energy, E. The coefficients asub(+-), in A=+-P(p/E)(1+asub(+-)E), have been determined to be a-(/sup 12/B)=+(0.31+-0.06)%/MeV and a+(/sup 12/N)=-(0.21+-0.07)%/MeV. The experimental value, asub(-)-asub(+)=(0.52+-0.09)%/MeV, is larger than the prediction according to conservation of vector current, (asub(-)-asub(+))cvc asymptotically equals 0.27%/MeV, which includes no second-class current. Thus, the result is in favor of the existence of the second-class induced-tensor current.

Intestinal synthesis and absorption of vitamin B-12 in channel catfish

International Nuclear Information System (INIS)

Limsuwan, T.; Lovell, R.T.

1981-01-01

A feeding experiment conducted in a controlled environment and using a vitamin B12-deficient, but otherwise nutritionally complete, purified diet revealed that intestinal microorganisms in channel catfish synthesized approximately 1.4 ng of vitamin B12 per gram of bodyweight per day. Removal of cobalt from the diet or supplementation with an antibiotic (succinylsulfathiazole) significantly reduced the rate of intestinal synthesis and liver stores of vitamin B12. Radiolabeled vitamin B12 in the blood, liver, kidneys, and spleen of fish fed 60Co in the diet indicated that the intestinally synthesized vitamin was absorbed by the fish. The primary route of absorption was directly from the digestive tract into the blood because coprophagy was prevented in the rearing aquariums and the amount of vitamin B12 dissolved in the aquarium water was too low for gill absorption. Dietary supplementation of vitamin B12 was not necessary for normal growth and erythrocyte formation in channel catfish in a 24-week feeding period. A longer period, however, may have caused a vitamin deficiency since liver-stored vitamin B 12 decreased between the 2nd and 24th weeks

Vitamin B(12) Immunoassay on Roche Elecsys 2010: Effects of High Excess Concentration of Serum Vitamin B(12) in CKD Patients on Parenteral Administration.

Science.gov (United States)

Basu, Surupa; Chaudhuri, Subimal

2011-10-01

Vitamin B(12) being water soluble is excreted in the urine when administered in excess. The probability of finding an abnormally excess serum concentration would be almost surreal. We report a peculiar clinical situation that may impact the vitamin B(12) immunoassay on the Roche Elecsys 2010 due to excess analyte concentration. In separate episodes (Feb and June 2010), the Biochemistry laboratory of a tertiary-care hospital, Kolkata, India, encountered two critically ill patients with background chronic kidney disease (CKD), low urine output, and on cyanocoabalamin supplementation, who had serum vitamin B(12) concentrations far exceeding expected values; even post dialysis. The B(12) assays (pmol/l) were performed using electrochemiluminiscence immunoassay on Roche Elecsys 2010, the assay validity confirmed by concomitant quality control runs. The immunoassays failed to deliver results, flagged with "signal level below limit". Biotin therapy was ruled out as a possible interferent. In the first episode, re-assay of a repeat draw yielded same outcome; outsourcing on Immulite provided concentration of >738 pmol/l. Serial dilution gave result of >29520 pmol/l on Elecsys 2010. In the second, we gained from past experience. Vitamin B(12) concentration >59040 pmol/l was conveyed to the treating nephrologist the very day. The B(12) immunoassay on the Elecsys 2010 employs sequential incubation steps for competitive binding that is compromised in the event of abnormally excess B(12) concentration in patient sera akin to the prozone effect. This knowledge may be beneficial while assaying sera of CKD patients to avoid financial loss due unnecessary repeats and delay in turnaround time.

Purification of rat intestinal receptor for intrinsic factor-vitamin B12 complex

International Nuclear Information System (INIS)

Yamada, Shoji; Itaya, Harutaka; Nakazawa, Osamu; Fukuda, Morimichi.

1977-01-01

The intrinsic factor (IF) in a rat gastric mucosal extract was bound efficiently to vitamin B 12 -sepharose without significant change in its nature to produce IF-vitamin B 12 -sepharose. The purification of the intestinal receptor for the IF-vitamin B 12 complex was performed by the affinity chromatography using the IF-vitamin B 12 -sepharose as the affinity adsorbent. As a result of admixing the gastric mucosal extract sample with B 12 -sepharose while stirring for 4 hours, the adsorption was performed without any break through. Further, it was recognized that the B 12 -bound protein purified by the affinity chromatography using B 12 -sepharose was not much changed as compared with that before purification. Furthermore, it was recognized that IF-B 12 -sepharose was able to be made by binding IF with B 12 -sepharose which was made by coupling B 12 with the market-available AH-sepharose. The IF-B 12 -sepharose was washed with buffer solution, and then was loaded with the small intestine mucosal extract. Thereafter, the receptor was eluted by making di-valent cation inert with the buffer solution. After the removal of EDTA in the eluted solution by dialysis, the activity of the receptor was measured. 48.5% of the receptor activity loaded was recovered by the elution with EDTA. The specific activity of the receptor represented by the final amount of B 12 (pg)/the amount of protein (mg) in the purified substance was 335 folds of the original activity. (Iwakiri, K.)

Proton Pump Inhibitors Intake and Iron and Vitamin B12 Status: A Prospective Comparative Study with a Follow up of 12 Months

OpenAIRE

Qorraj-Bytyqi, Hasime; Hoxha, Rexhep; Sadiku, Shemsedin; Bajraktari, Ismet H.; Sopjani, Mentor; Thaçi, Kujtim; Thaçi, Shpetim; Bahtiri, Elton

2018-01-01

BACKGROUND: Proton pump inhibitors (PPIs) represent the most widely prescribed antisecretory agents, but their prolonged use, may influence iron and vitamin B12 status, which could have important implications for clinical practice. AIM: We undertook this study aiming to investigate the association between PPIs use for 12 months and potential changes in iron and vitamin B12 status, as well as whether this potential association varies among four specific PPI drugs used in the study. MET...

WASP-12b and Its Possible Fiery Demise

Science.gov (United States)

Kohler, Susanna

2017-07-01

Jupiter-like planets on orbits close to their hosts are predicted to spiral ever closer to their hosts until they meet their eventual demise and yet weve never observed orbital decay. Could WASP-12b provide the first evidence?Undetected PredictionsSince the discovery of the first hot Jupiter more than 20 years ago, weve studied a number of these peculiar exoplanets. Despite our many observations, two phenomena predicted of hot Jupiters have not yet been detected, due to the long timescales needed to identify them:Tidal orbital decayTidal forces should cause a hot Jupiters orbit to shrink over time, causing the planet to eventually spiral into its host star. This phenomenon would explain a number of statistical properties of observed star-planet systems (for instance, the scarcity of gas giants with periods less than a day).An illustration of apsidal precession. [Mpfiz]Apsidal precessionThe orbits of hot Jupiters should be apsidally precessing on timescales of decades, as long as they are at least slightly eccentric. Since the precession rate depends on the planets tidally deformed mass distribution, measuring this would allow us to probe the interior of the planet.A team of scientists led by Kishore Patra (Massachusetts Institute of Technology) think that the hot Jupiter WASP-12b may be our first chance to study one of these two phenomena. The question is, which one?WASP-12bWASP-12b has orbital period of 1.09 days one of the shortest periods observed for a giant planet and weve monitored it for a decade, making it a great target to test for both of these long-term effects.Timing residuals for WASP-12b. Squares show the new data points, circles show previous data from the past decade. The data are better fit by the decay model than the precession model, but both are still consistent. [Patra et al. 2017]Patra and collaborators made transit observations with the 1.2-m telescope at the Fred Lawrence Whipple Observatory in Arizona and occultation observations with the

Interaction of conjugated bile acids and detergents with a radiosorbent assay of vitamin B-12

International Nuclear Information System (INIS)

Andersen, K.-J.; Romslo, I.

1977-01-01

The effect of conjugated bile acids and detergents on the radiosorbent technique for the determination of vitamin B-12 activity is reported. It is shown that whereas the non-ionic detergent Triton X-100 has no effect on the vitamin B-12-radiosorbent assay, the addition of ionic detergents, e.g. glycocholic acid, taurocholic acid or sodium lauryl sulfate, results in a falsely-elevated vitamin B-12 activity presumably due to the disruption of the binding of vitamin B-12 to the intrinsic factor-Sephadex complex. This effect may be of importance not only to the radiosorbent assaying of vitamin B-12, but to the in vivo intestinal absorption of vitamin B-12 as well

Homocyst(e)ine, folate, and vitamin B12 status in a cohort of Welsh young people aged 12-13 years old.

Science.gov (United States)

Thomas, N E; Cooper, S M; Baker, J S; Graham, M R; Davies, B

2008-01-01

The aim of this unique study was to consider the relationship between folate and vitamin B(12) on homocyst(e)ine (Hcy) concentration in an apparently healthy cohort of Welsh young people. A cohort of 179, 12-13 year olds (88 boys and 91 girls) were measured for Hcy, folate, vitamin B(12), adiposity, and dietary habits. Boys had significantly higher waist circumference and folate concentration than girls. Folate was negatively associated with Hcy in both sexes, whereas vitamin B(12) was negatively associated with Hcy in boys only. Adiposity was not associated with Hcy. Folate was an independent predictor of Hcy in both sexes, whilst vitamin B(12) was an independent determinant of Hcy in boys only. Familial history of cardiovascular disease (CVD) risk factors was identified in 69% of the children with elevated Hcy (> or = 8.5 mumol.L(-1)). Young people might be encouraged to increase their folate intake through diet, particularly by increasing their consumption of leafy vegetables and fruit. Further research is necessary to determine the exact contribution of genetics and diet on Hcy levels in young people, and whether Hcy levels during childhood and adolescence might influence future CVD risk.

Diamagnetism of the B10H12L2 series compounds

International Nuclear Information System (INIS)

Volkov, V.V.; Ikorskij, V.N.; Dunaev, S.T.

1988-01-01

The method of static magnetic susceptibility is used to study diamagnetic susceptibilities of a number of B 10 H 12 L 2 (where L - nitrogen, sulfur, phosphorus-containing organic ligands) decaborane-derivatives and to draw the increment χ M -125 for the nido cluster (B 10 H 12 ) and boron atomic increment χ bar M -9.0 in this cluster. The absolute value χ B in (B 10 H 12 ) cluster is much higher than χ B for noncluster systems (2.7-7.6). This difference proves electron delocalization in (B 10 H 12 ) and the aromatic nature of this nido-cluster

Vitamin B12 Deficiency in Type 2 Diabetes Mellitus

Directory of Open Access Journals (Sweden)

Carlos Tavares Bello

2017-10-01

Conclusion: Further studies are needed to identify the risk factors for the B12 deficit. The recognition of these variables will contribute to optimize the screening and prevention of the B12 deficiency in type 2 diabetes mellitus.

Identification of differentially expressed proteins in vitamin B 12

Directory of Open Access Journals (Sweden)

Swati Varshney

2015-01-01

Full Text Available Background: Vitamin B 12 (cobalamin is a water-soluble vitamin generally synthesized by microorganisms. Mammals cannot synthesize this vitamin but have evolved processes for absorption, transport and cellular uptake of this vitamin. Only about 30% of vitamin B 12 , which is bound to the protein transcobalamin (TC (Holo-TC [HoloTC] enters into the cell and hence is referred to as the biologically active form of vitamin B 12 . Vitamin B 12 deficiency leads to several complex disorders, including neurological disorders and anemia. We had earlier shown that vitamin B 12 deficiency is associated with coronary artery disease (CAD in Indian population. In the current study, using a proteomics approach we identified proteins that are differentially expressed in the plasma of individuals with low HoloTC levels. Materials and Methods: We used isobaric-tagging method of relative and absolute quantitation to identify proteins that are differently expressed in individuals with low HoloTC levels when compared to those with normal HoloTC level. Results: In two replicate isobaric tags for relative and absolute quantitation experiments several proteins involved in lipid metabolism, blood coagulation, cholesterol metabolic process, and lipoprotein metabolic process were found to be altered in individuals having low HoloTC levels. Conclusions: Our study indicates that low HoloTc levels could be a risk factor in the development of CAD.

Vitamin B12 and folate deficiency in chronic heart failure.

Science.gov (United States)

van der Wal, Haye H; Comin-Colet, Josep; Klip, Ijsbrand T; Enjuanes, Cristina; Grote Beverborg, Niels; Voors, Adriaan A; Banasiak, Waldemar; van Veldhuisen, Dirk J; Bruguera, Jordi; Ponikowski, Piotr; Jankowska, Ewa A; van der Meer, Peter

2015-02-01

To determine the prevalence, clinical correlates and the effects on outcome of vitamin B12 and folic acid levels in patients with chronic heart failure (HF). We studied an international pooled cohort comprising 610 patients with chronic HF. The main outcome measure was all-cause mortality. Mean age of the patients was 68±12 years and median serum N-terminal prohormone brain natriuretic peptide level was 1801 pg/mL (IQR 705-4335). Thirteen per cent of the patients had an LVEF >45%. Vitamin B12 deficiency (serum level <200 pg/mL), folate deficiency (serum level <4.0 ng/mL) and iron deficiency (serum ferritin level <100 µg/L, or 100-299 µg/L with a transferrin saturation <20%) were present in 5%, 4% and 58% of the patients, respectively. No significant correlation between mean corpuscular volume and vitamin B12, folic acid or ferritin levels was observed. Lower folate levels were associated with an impaired health-related quality of life (p=0.029). During a median follow-up of 2.10 years (1.31-3.60 years), 254 subjects died. In multivariable proportional hazard models, vitamin B12 and folic acid levels were not associated with prognosis. Vitamin B12 and folate deficiency are relatively rare in patients with chronic HF. Since no significant association was observed between mean corpuscular volume and neither vitamin B12 nor folic acid levels, this cellular index should be used with caution in the differential diagnosis of anaemia in patients with chronic HF. In contrast to iron deficiency, vitamin B12 and folic acid levels were not related to prognosis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Malabsorption of vitamin B12 in homozygous β-thalassemia

International Nuclear Information System (INIS)

Vlachos, P.; Liakakos, D.

1976-01-01

Schilling tests were performed in ten children aged 5-12 years suffering from homozygous β-thalassemia. 57 Co labelled vitamin B 12 values excreted in the urine have been found much lower than normal and remained low when the same procedure was repeated with the addition of intrinsic factor. The possible factors responsible for this malabsorption of vitamin B 12 seemed to be liver damage and folic acid deficiency. (orig.) [de

The determination of serum vitamin B/sub 12/ values using radioassay

Energy Technology Data Exchange (ETDEWEB)

Kariyone, S; Morishita, R; Sato, M; Fujimori, K; Miki, M [Kyoto Univ. (Japan). Faculty of Medicine

1975-04-01

Strong and weak points of both the Phadebas B/sub 12/ test kit by Pharmacia Co. Ltd. and the CIS B/sub 12/ kit by CEA Co. Ltd. were examined to determine and evaluated. One strong point was that both of kits were comparatively easy to operate. Another was that they were very accurate if only one pipet was used and it was correctly handled. The error from the fractional infusion of 0.1 ml of /sup 57/Co-B/sub 12/ sample remained within +-1.8%, including the error of measuring radioactivity. The recovery rate of vitamin B/sub 12/ added to the serum was 100+-10%. Close correlation was found between the serum B/sub 12/ values measured by each kit and with a careful procedure almost accurate, highly reproducible values were obtained. It was necessary to further examine the pH of the buffer solution in the Phadebas kit and the conditions of extraction of B/sub 12/ from the serum in the CIS kit. In reading the B/sub 12/ values from the standard curve, it was preferable to perform a logic change B/B/sub 0/ % in the samples and to make a linear standard curve, so that the accuracy of the reading would not be infuluenced by variations in the data. (Kanao, N.).

B12 deficiency increases with age in hospitalized patients: a study on 14,904 samples.

Science.gov (United States)

Mézière, Anthony; Audureau, Etienne; Vairelles, Stéphane; Krypciak, Sébastien; Dicko, Michèle; Monié, Marguerite; Giraudier, Stéphane

2014-12-01

Cobalamin deficiency is responsible for hematological, neurological, neurocognitive, and neuropsychiatric impairments and is a risk factor for cardiovascular diseases, particularly in the elderly people. In order to determine B12 status in old inpatients, a total number of 14,904 hospitalized patients in whom B12 measurements were performed in five hospitals in the Paris metropolitan area were included from January 1, 2011 to December 31, 2011. The aims of the study were to determine whether age had an impact on B12 and folate deficiencies and to evaluate correlations between B12 and biological parameters-folate, hemoglobin, mean cell volume, homocystein (tHcy)-and age. Patients were aged 70.3±19.5 years. Low B12 concentration ( 17 µmol/L), 20.4% had low folate concentration (folate 17 µmol/L), and 4.7% of patients were both functional B12 and folate deficient. The B12 or folate deficient patients had lower mean cell volume level than nondeficient patients. Increase in mean cell volume and tHcy concentrations with age and decrease in B12, folate, and hemoglobin levels with age were observed. Frequency of functional B12 deficiency was 9.6% in patients aged 30-60 years and 14.2% in patients over 90 years. Frequency of functional folate deficiency was 9.5% in 30-60 years and 12.1% in >90 years. In inpatients, functional B12 deficiency and functional folate deficiency increase with age and are not associated with anemia or macrocytosis. False vitamin B deficiencies are frequent. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Permanent magnet machine and method with reluctance poles and non-identical PM poles for high density operation

Science.gov (United States)

Hsu, John S.

2010-05-18

A method and apparatus in which a stator (11) and a rotor (12) define a primary air gap (20) for receiving AC flux and at least one source (23, 40), and preferably two sources (23, 24, 40) of DC excitation are positioned for inducing DC flux at opposite ends of the rotor (12). Portions of PM material (17, 17a) are provided as boundaries separating PM rotor pole portions from each other and from reluctance poles. The PM poles (18) and the reluctance poles (19) can be formed with poles of one polarity having enlarged flux paths in relation to flux paths for pole portions of an opposite polarity, the enlarged flux paths communicating with a core of the rotor (12) so as to increase reluctance torque produced by the electric machine. Reluctance torque is increased by providing asymmetrical pole faces. The DC excitation can also use asymmetric poles and asymmetric excitation sources. Several embodiments are disclosed with additional variations.

Vitamin b 12 supplementation: effects on some biochemical and ...

African Journals Online (AJOL)

Phenytoin is known to have some toxicological implications. Vitamin B12 supplementation during phenytoin administration was investigated to assess the benefits and risks of single vitamin supplementation. This study evaluated the biochemical and haematological effects of vitamin B12 on phenytoin toxicity. Twenty-four ...

Integral measurement of the {sup 12}C(n, p){sup 12}B reaction up to 10 GeV

Energy Technology Data Exchange (ETDEWEB)

Zugec, P.; Bosnar, D. [University of Zagreb, Department of Physics, Faculty of Science, Zagreb (Croatia); Colonna, N.; Barbagallo, M.; Mastromarco, M.; Tagliente, G.; Variale, V. [Istituto Nazionale di Fisica Nucleare, Bari (Italy); Ventura, A. [Istituto Nazionale di Fisica Nucleare, Bologna (Italy); Mengoni, A. [ENEA, Bologna (Italy); Altstadt, S.; Langer, C.; Lederer, C.; Reifarth, R.; Schmidt, S.; Weigand, M. [Johann-Wolfgang-Goethe Universitaet, Frankfurt (Germany); Andrzejewski, J.; Marganiec, J.; Perkowski, J. [Uniwersytet Lodzki, Lodz (Poland); Audouin, L.; Leong, L.S.; Tassan-Got, L. [Centre National de la Recherche Scientifique/IN2P3 - IPN, Orsay (France); Becares, V.; Cano-Ott, D.; Garcia, A.R.; Gonzalez-Romero, E.; Martinez, T.; Mendoza, E. [Centro de Investigaciones Energeticas Medioambientales y Tecnologicas (CIEMAT), Madrid (Spain); Becvar, F.; Krticka, M.; Kroll, J.; Valenta, S. [Charles University, Prague (Czech Republic); Belloni, F.; Mondalaers, W.; Plompen, A.; Schillebeeckx, P. [European Commission JRC, Institute for Reference Materials and Measurements, Geel (Belgium); Berthoumieux, E.; Fraval, K.; Gunsing, F. [CEA/Saclay - IRFU, Gif-sur-Yvette (France); Billowes, J.; Ware, T.; Wright, T. [University of Manchester, Manchester (United Kingdom); Boccone, V.; Brugger, M.; Calviani, M.; Cerutti, F.; Chiaveri, E.; Chin, M.; Ferrari, A.; Guerrero, C.; Losito, R.; Roman, F.; Rubbia, C.; Tsinganis, A.; Versaci, R.; Vlachoudis, V.; Weiss, C. [CERN, Geneva (Switzerland); Calvino, F.; Cortes, G.; Gomez-Hornillos, M.B.; Riego, A. [Universitat Politecnica de Catalunya, Barcelona (Spain); Carrapico, C.; Goncalves, I.F.; Sarmento, R.; Vaz, P. [Universidade de Lisboa, C2TN-Instituto Superior Tecnico, Lisboa (Portugal); Cortes-Giraldo, M.A.; Praena, J.; Quesada, J. [Universidad de Sevilla, Sevilla (Spain); Cosentino, L.; Finocchiaro, P. [INFN - Laboratori Nazionali del Sud, Catania (Italy); Diakaki, M.; Karadimos, D.; Kokkoris, M.; Vlastou, R. [National Technical University of Athens (NTUA), Athens (Greece); Domingo-Pardo, C.; Giubrone, G.; Tain, J.L. [CSIC-Universidad de Valencia, Instituto de Fisica Corpuscular, Valencia (Spain); Dressler, R.; Heinitz, S.; Kivel, N.; Schumann, D. [Paul Scherrer Institut, Villigen (Switzerland); Duran, I.; Tarrio, D. [Universidade de Santiago de Compostela, Santiago de Compostela (Spain); Eleftheriadis, C.; Manousos, A. [Aristotle University of Thessaloniki, Thessaloniki (Greece); Ganesan, S.; Gurusamy, P.; Saxena, A. [Bhabha Atomic Research Centre (BARC), Mumbai (India); Griesmayer, E.; Jericha, E.; Leeb, H. [Atominstitut der Oesterreichischen Universitaeten, Technische Universitaet Wien, Wien (Austria); Jenkins, D.G.; Vermeulen, M.J. [University of York, York, Heslington (United Kingdom); Kaeppeler, F. [Karlsruhe Institute of Technology (KIT), Institut fuer Kernphysik, Karlsruhe (Germany); Lo Meo, S. [Istituto Nazionale di Fisica Nucleare, Bologna (Italy); ENEA, Bologna (Italy); Massimi, C.; Mingrone, F.; Vannini, G. [Dipartimento di Fisica, Universita di Bologna (IT); INFN, Bologna (IT); Mastinu, P. [Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Legnaro (IT); Milazzo, P.M. [Istituto Nazionale di Fisica Nucleare, Trieste (IT); Mirea, M. [Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN HH, Magurele (RO); Musumarra, A. [Universita di Catania, Dipartimento di Fisica e Astronomia DFA, Catania (IT); INFN-Laboratori Nazionali del Sud, Catania (IT); Paradela, C. [European Commission JRC, Institute for Reference Materials and Measurements, Geel (BE); Universidade de Santiago de Compostela, Santiago de Compostela (ES); Pavlik, A. [Faculty of Physics, University of Vienna, Wien (AT); Rauscher, T. [University of Hertfordshire, Centre for Astrophysics Research, School of Physics, Astronomy and Mathematics, Hatfield (GB); University of Basel, Department of Physics, Basel (CH); Wallner, A. [Faculty of Physics, University of Vienna, Wien (AT); Australian National University, Research School of Physics and Engineering, Canberra (AU)

2016-04-15

The integral measurement of the {sup 12}C(n, p){sup 12}B reaction was performed at the neutron time-of-flight facility nTOF at CERN. The total number of {sup 12}B nuclei produced per neutron pulse of the nTOF beam was determined using the activation technique in combination with a time-of-flight technique. The cross section is integrated over the nTOF neutron energy spectrum from reaction threshold at 13.6 MeV to 10 GeV. Having been measured up to 1GeV on basis of the {sup 235}U(n, f) reaction, the neutron energy spectrum above 200 MeV has been re-evaluated due to the recent extension of the cross section reference for this particular reaction, which is otherwise considered a standard up to 200 MeV. The results from the dedicated GEANT4 simulations have been used to evaluate the neutron flux from 1 GeV up to 10 GeV. The experimental results related to the {sup 12}C(n, p){sup 12}B reaction are compared with the evaluated cross sections from major libraries and with the predictions of different GEANT4 models, which mostly underestimate the {sup 12}B production. On the contrary, a good reproduction of the integral cross section derived from measurements is obtained with TALYS-1.6 calculations, with optimized parameters. (orig.)

Metformin increases liver accumulation of vitamin B12 - An experimental study in rats

DEFF Research Database (Denmark)

Greibe, E; Miller, J W; Foutouhi, S H

2013-01-01

AIMS/HYPOTHESIS: Patients treated with metformin exhibit low levels of plasma vitamin B(12) (B(12)), and are considered at risk for developing B(12) deficiency. In this study, we investigated the effect of metformin treatment on B(12) uptake and distribution in rats. METHODS: Sprague Dawley rats (n...... that metformin has no decreasing effect on the B(12) absorption. CONCLUSIONS/INTERPRETATION: These results show that metformin treatment increases liver accumulation of B(12), thereby resulting in decreases in circulating B(12) and kidney accumulation of the vitamin. Our data questions whether the low plasma B......(12) observed in patients treated with metformin reflects impaired B(12) status, and rather suggests altered tissue distribution and metabolism of the vitamin....

Vitamin B-12 treatment of asymptomatic, deficient, elderly Chileans improves conductivity in myelinated periphreal nerves, but high serum folate impairs vitamin B-12 status response assessed by the combined indicator of..

Science.gov (United States)

Since 2005 the National Feeding Program for the Elderly (PACAM) in Chile has provided a B12 fortified milk drink (1.7 µg B12/d) which is insufficient to ensure B12 adequacy in many individuals. The objective was to evaluate effects of adding 1 mg B12/d to PACAM vs 1 mg B12/d as a pill with PACAM on ...

Bipolaron formation in B/sub 12/ and (B/sub 11/C)/sup +/ icosahedra

International Nuclear Information System (INIS)

Howard, I.A.; Beckel, C.L.; Emin, D.

1987-01-01

Boron carbides, B/sub 1-x/C/sub x/ with 0.085 ≤ x ≤ 0.200, generally contain both B/sub 12/ and B/sub 11/C icosahedra. However, the electronic transport with 0.1 ≤ x ≤ 0.2 is believed to occur by means of bipolaron hopping between only B/sub 11/C icosahedra. The authors have calculated the changes in energy, atomic positions and charge distribution when a pair of electrons is added to the isoelectronic icosahedral clusters B/sub 12/ and (B/sub 11/C)/sup +/. They simulate an icosahedron in a neutral lattice by bonding the icosahedral atoms to hydrogenic atoms which the authors constrain to be neutral. The computations are performed with a self-consistent molecular-orbital method, PRDDO. They find a total energy reduction of -- 3.7 eV for two electrons added to a B/sub 12/ icosahedron. Of this, -- 2.7 eV arises from the electrons filling the icosahedron's bonding orbitals. The remaining -- 1.0 eV comes from the contraction of the icosahedron's radius by -- 0.09 A. For two electrons added to a (B/sub 11/C)/sup +/ icosahedron the authors find a total energy reduction of -- 18.2 eV. Of this, -- 16.5 eV arises from filling the icosahedron's bonding orbitals. The remainder arises from a -- 0.09 A contraction of the icosahedron's radius. Thus, the authors find (B/sub 11/C)/sup +/ icosahedra to be strongly energetically favored over B/sub 12/ icosahedra as bipolaron sites. The positive charge associated with a (B/sub 11/C)/sup +/ icosahedron is distributed over the eleven boron atoms. Concomitantly, they find the added two electrons of the bipolaron to be distributed over all twelve sites of the B/sub 11/C icosahedron. They find the energy difference between an electron pair added to B/sub 12/ and (B/sub 11/C)/sup +/ icosahedra to arise principally from the increased Coulombic attraction provided by the extra positive charge of the (B/sub 11/C)/sup +/ icosahedron

12 CFR 708b.101 - Mergers generally.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Mergers generally. 708b.101 Section 708b.101 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS MERGERS OF FEDERALLY-INSURED CREDIT UNIONS; VOLUNTARY TERMINATION OR CONVERSION OF INSURED STATUS Mergers § 708b.101...

Papel da vitamina B12 na patogenia da mielose funicular

Directory of Open Access Journals (Sweden)

Horacio M. Canelas

1965-12-01

Full Text Available Foi estudada a absorção da vitamina B12 radioativa em 29 casos de mielose funicular. O diagnóstico baseou-se na clássica sintomatologia neu- rológica e na presença de acloridria gástrica e eventuais alterações hemato-lógicas. As manifestações neurológicas foram avaliadas de modo semiquan-titativo e correlacionadas com os resultados do teste de excreção urinária da vitamina B12. Não foi verificada correlação significante da absorção da vitamina B12, quer com a sintomatologia nuerológica total, quer com as síndromes periférica e funicular dorsal. Contudo, foi encontrada significante correlação negativa entre a síndrome piramidal e a absorção da vitamina B12. Os resultados são confrontados com o papel desempenhado pela vitamina B12 na síntese das bainhas de mielina e do ácido ribonuclêico, sendo salientada a importância dêste último para a vida das células nervosas e dos longos axônios.

A general review on vitamin B12 deficiency with focus on the situation in Jordan

International Nuclear Information System (INIS)

Qutob, M. S.; Takruri, H. R.

2011-01-01

Vitamin B 12 (cobalamin) is an essential nutrient that is only obtained from foods of animal origin, such as meat, eggs and dairy products. Vitamin B 12 plays an important role in DNA synthesis and neurological function. Thus its deficiency can lead to several neurological symptoms such as memory loss, dizziness and in severe cases may lead to dementia. Many factors can cause or lead to vitamin B-1 2 deficiency. Among these are malabsorption, several gastron intestinal problems (i.e. celiac disease, Crobn's disease) and gastrointestinal surgeries. diagnosis of vitamin B-1 2 status depends commonly on serum vitamin B 12 which is nonspecific tool for the deficiency. Other more specific tests, which reflect true deficiency, include serum and urine methylmalonic aci de, total serum homocysteine and serum holotranscobalamin. Vitamin B 12 deficiency is a worldwide public health problem; epidemiological studies showed that its prevalence in industrialized countries ranges from 5-60% of the population depending on the used cutoff point of cobalamin level. In Jordan, many reports were published on vitamin B 12 deficiency. However, these reports gave different results of its prevalence ranging from 16-48% depending on the serum vitamin B 12 cutoff point used. A recent study showed a prevalence of true deficiency of 32.7% based on measuring both serum vitamin B 12 level and plasma methylmalonic acid. (authors).

Beta-decay asymmetries in polarized /sup 12/B and /sup 12/N and the G-parity non-conservation

Energy Technology Data Exchange (ETDEWEB)

Sugimoto, K [Osaka Univ., Toyonaka (Japan). Dept. of Physics

1976-07-01

The decay asymmetries (A) in polarized /sup 12/B and /sup 12/N have been measured as a function of ..beta..-ray energies (E). The coefficients ..cap alpha..sub(-+) in A = -+ P(p/E) (1 + ..cap alpha..sub(-+)E)) have been determined to be ..cap alpha..sub(-) (/sup 12/B) = +(0.31+-0.06)%/MeV and ..cap alpha..sub(+) (/sup 12/N) = -(0.21+-0.07)%/MeV. The experimental value, ..cap alpha..sub(-) - ..cap alpha..sub (+) = (0.52+-0.09)%/MeV, is larger than the prediction according to conservation of vector current which includes no second-class current, (..cap alpha..sub(-) - ..cap alpha..sub(+) CVC approximately equal to 0.27%/MeV, and indicates the existence of the second-class induced-tensor current.

Vitamin B12: unique metalorganic compounds and the most complex vitamins.

Science.gov (United States)

Randaccio, Lucio; Geremia, Silvano; Demitri, Nicola; Wuerges, Jochen

2010-04-30

The chemistry and biochemistry of the vitamin B(12) compounds (cobalamins, XCbl) are described, with particular emphasis on their structural aspects and their relationships with properties and function. A brief history of B(12), reveals how much the effort of chemists, biochemists and crystallographers have contributed in the past to understand the basic properties of this very complex vitamin. The properties of the two cobalamins, the two important B(12) cofactors Ado- and MeCbl are described, with particular emphasis on how the Co-C bond cleavage is involved in the enzymatic mechanisms. The main structural features of cobalamins are described, with particular reference to the axial fragment. The structure/property relationships in cobalamins are summarized. The recent studies on base-off/base-on equilibrium are emphasized for their relevance to the mode of binding of the cofactor to the protein scaffold. The absorption, transport and cellular uptake of cobalamins and the structure of the B(12) transport proteins, IF and TC, in mammals are reviewed. The B(12) transport in bacteria and the structure of the so far determined proteins are briefly described. The currently accepted mechanisms for the catalytic cycles of the AdoCbl and MeCbl enzymes are reported. The structure and function of B(12) enzymes, particularly the important mammalian enzymes methyltransferase (MetH) and methyl-malonyl-coenzyme A mutase (MMCM), are described and briefly discussed. Since fast proliferating cells require higher amount of vitamin B(12) than that required by normal cells, the study of B(12 )conjugates as targeting agents has recently gained importance. Bioconjugates have been studied as potential agents for delivering radioisotopes and NMR probes or as various cytotoxic agents towards cancer cells in humans and the most recent studies are described. Specifically, functionalized bioconjugates are used as "Trojan horses" to carry into the cell the appropriate antitumour or diagnostic

Vitamin B12: Unique Metalorganic Compounds and the Most Complex Vitamins

Directory of Open Access Journals (Sweden)

Lucio Randaccio

2010-04-01

Full Text Available The chemistry and biochemistry of the vitamin B12 compounds (cobalamins, XCbl are described, with particular emphasis on their structural aspects and their relationships with properties and function. A brief history of B12, reveals how much the effort of chemists, biochemists and crystallographers have contributed in the past to understand the basic properties of this very complex vitamin. The properties of the two cobalamins, the two important B12 cofactors Ado- and MeCbl are described, with particular emphasis on how the Co-C bond cleavage is involved in the enzymatic mechanisms. The main structural features of cobalamins are described, with particular reference to the axial fragment. The structure/property relationships in cobalamins are summarized. The recent studies on base-off/base-on equilibrium are emphasized for their relevance to the mode of binding of the cofactor to the protein scaffold. The absorption, transport and cellular uptake of cobalamins and the structure of the B12 transport proteins, IF and TC, in mammals are reviewed. The B12 transport in bacteria and the structure of the so far determined proteins are briefly described. The currently accepted mechanisms for the catalytic cycles of the AdoCbl and MeCbl enzymes are reported. The structure and function of B12 enzymes, particularly the important mammalian enzymes methyltransferase (MetH and methyl-malonyl-coenzymeA mutase (MMCM, are described and briefly discussed. Since fast proliferating cells require higher amount of vitamin B12 than that required by normal cells, the study of B12 conjugates as targeting agents has recently gained importance. Bioconjugates have been studied as potential agents for delivering radioisotopes and NMR probes or as various cytotoxic agents towards cancer cells in humans and the most recent studies are described. Specifically, functionalized bioconjugates are used as “Trojan horses” to carry into the cell the appropriate antitumour or

Purification and characterization of nattokinase from Bacillus subtilis natto B-12.

Science.gov (United States)

Wang, Cong; Du, Ming; Zheng, Dongmei; Kong, Fandong; Zu, Guoren; Feng, Yibing

2009-10-28

Bacillus subtilis natto B-12 was isolated from natto, a traditional fermented soybean food in Japan. A fibrinolytic enzyme (B-12 nattokinase) was purified from the supernatant of B. subtilis natto B-12 culture broth and showed strong fibrinolytic activity. The enzyme was homogenously purified to 56.1-fold, with a recovery of 43.2% of the initial activity. B-12 nattokinase was demonstrated to be homogeneous by SDS-PAGE and was identified as a monomer of 29000 +/- 300 Da in its native state by SDS-PAGE and size exclusion methods. The optimal pH value and temperature were 8.0 and 40 degrees C, respectively. Purified nattokinase showed high thermostability at temperatures from 30 to 50 degrees C and alkaline stability within the range of pH 6.0-9.0. The enzyme activity was activated by Zn(2+) and obviously inhibited by Fe(3+) and Al(3+). This study provides some important information for the effect factors of fibrinolytic activity, the purification methods, and characterization of nattokinase from B. subtilis natto B-12, which enriches the theoretical information of nattokinase for the research and development of nattokinase as a functional additive of food.

Vitamin B12 supplement alleviates N'-nitrosodimethylamine-induced hepatic fibrosis in rats.

Science.gov (United States)

Ahmad, Areeba; Afroz, Nishat; Gupta, Umesh D; Ahmad, Riaz

2014-01-10

Abstract Context: Altered vitamin B 12 levels have been correlated with hepatotoxicity; however, further evidence is required to establish its protective role. Objective: To evaluate the effects of vitamin B 12 supplement in protecting N'-nitrosodimethylamine (NDMA)-induced hepatic fibrosis in Wistar rats. Materials and methods: Hepatic fibrosis was induced by administering NDMA in doses of 10 mg/kg body weight thrice a week for 21 days. Another group received equal doses (10 mg/kg body weight) of vitamin B 12 subsequent to NDMA treatment. Animals from either group were sacrificed weekly from the start of the treatment along with their respective controls. Progression of hepatic fibrosis, in addition to the effect of vitamin B 12 , was assessed biochemically for liver function biomarkers, liver glycogen, hydroxyproline (HP) and B 12 reserves along with histopathologically by hematoxylin and eosin (H & E) as well immunohistochemical staining for α-SMA expression. Results and discussion: Elevation in the levels of aminotransferases, SALP, total bilirubin and HP was observed in NDMA treated rats, which was concomitant with remarkable depletion in liver glycogen and B 12 reserves (p < 0.05). Liver biopsies also demonstrated disrupted lobular architecture, collagen amassing and intense fibrosis by NDMA treatment. Immunohistochemical staining showed the presence of activated stellate cells that was dramatically increased up to day 21 in fibrotic rats. Following vitamin B 12 treatment, liver function biomarkers, glycogen contents and hepatic vitamin B 12 reserves were restored in fibrotic rats, significantly. Vitamin B 12 administration also facilitated restoration of normal liver architecture. Conclusion: These findings provide interesting new evidence in favor of protective role for vitamin B 12 against NDMA-induced hepatic fibrosis in rats.

Radioactively labelled vitamin B12

Energy Technology Data Exchange (ETDEWEB)

Charlton, J C; Lewis, A

1976-12-01

A method is described for preparing radioactively labelled vitamin B 12 (cyanocobalamin) by reacting ..cap alpha..-(5,6-dimethylbenzimidazolyl) hydrogenobamide with active (sup(57,58)Co) cobaltous ion. The latter may be in the form of cobaltous chloride or sulphate in aqueous or aqueous alcoholic medium. The reaction is effected by heating the reactants in darkness at pH 4 to 8. An excess of cyanide is added to convert the hydroxocobalamin formed to cyanocobalamin.

Scalable synthesis of 5,11-diethynylated indeno[1,2-b]fluorene-6,12-diones and exploration of their solid state packing

Directory of Open Access Journals (Sweden)

Bradley D. Rose

2014-09-01

Full Text Available We report a new synthetic route to 5,11-disubstituted indeno[1,2-b]fluorene-6,12-diones that is amenable to larger scale reactions, allowing for the preparation of gram amounts of material. With this new methodology, we explored the effects on crystal packing morphology for the indeno[1,2-b]fluorene-6,12-diones by varying the substituents on the silylethynyl groups.

Genetic disorders of vitamin B12 metabolism: eight complementation groups – eight genes

Science.gov (United States)

Froese, D. Sean; Gravel, Roy A.

2010-01-01

Vitamin B12 (cobalamin, Cbl) is an essential nutrient in human metabolism. Genetic diseases of vitamin B12 utilisation constitute an important fraction of inherited newborn disease. Functionally, B12 is the cofactor for methionine synthase and methylmalonyl CoA mutase. To function as a cofactor, B12 must be metabolised through a complex pathway that modifies its structure and takes it through subcellular compartments of the cell. Through the study of inherited disorders of vitamin B12 utilisation, the genes for eight complementation groups have been identified, leading to the determination of the general structure of vitamin B12 processing and providing methods for carrier testing, prenatal diagnosis and approaches to treatment. PMID:21114891

Woodward's Synthesis of Vitamin B12

Indian Academy of Sciences (India)

consistently demonstrating the powerful use of logical reason- ing where it was customary to abandon such approaches. Barton further says, "We were taught to think that mechanism had nothing to do with 'real' Chemistry. With one lecture, Wood- ward showed us the contrary." Vitamin B12 is a large and complex molecule ...

Genetic determinants of serum vitamin B12 and their relation to body mass index

DEFF Research Database (Denmark)

Allin, Kristine H.; Friedrich, Nele; Pietzner, Maik

2017-01-01

for associations between (1) serum vitamin B12 levels and body mass index (BMI), (2) genetic variants and serum vitamin B12 levels, and (3) genetic variants and BMI. The effect of a genetically determined decrease in serum vitamin B12 on BMI was estimated by instrumental variable regression. Decreased serum......Lower serum vitamin B12 levels have been related to adverse metabolic health profiles, including adiposity. We used a Mendelian randomization design to test whether this relation might be causal. We included two Danish population-based studies (ntotal = 9311). Linear regression was used to test...... vitamin B12 associated with increased BMI (P vitamin B12 associated variants associated strongly with serum vitamin B12 (P vitamin B12...

Correlation between serum vitamin B12 level and peripheral neuropathy in atrophic gastritis

Science.gov (United States)

Yang, Guo-Tao; Zhao, Hong-Ying; Kong, Yu; Sun, Ning-Ning; Dong, Ai-Qin

2018-01-01

AIM To explore the correlation between serum vitamin B12 level and peripheral neuropathy in patients with chronic atrophic gastritis (CAG). METHODS A total of 593 patients diagnosed with chronic gastritis by gastroscopy and pathological examination from September 2013 to September 2016 were selected for this study. The age of these patients ranged within 18- to 75-years-old. Blood pressure, height and weight were measured in each patient, and the body mass index value was calculated. Furthermore, gastric acid, serum gastrin, serum vitamin and serum creatinine tests were performed, and peripheral nerve conduction velocity and Helicobacter pylori (H. pylori) were detected. In addition, the type of gastritis was determined by gastroscopy. The above factors were used as independent variables to analyze chronic gastritis with peripheral neuropathy and vitamin B12 deficiency risk factors, and to analyze the relationship between vitamin B12 levels and peripheral nerve conduction velocity. In addition, in the treatment of CAG on the basis of vitamin B12, patients with peripheral neuropathy were observed. RESULTS Age, H. pylori infection, CAG, vitamin B9 and vitamin B12 were risk factors for the occurrence of peripheral nerve degeneration. Furthermore, CAG and H. pylori infection were risk factors for chronic gastritis associated with vitamin B12 deficiency. Serum vitamin B12 level was positively correlated with sensory nerve conduction velocity in the tibial nerve (R = 0.463). After vitamin B12 supplementation, patients with peripheral neuropathy improved. CONCLUSION Serum vitamin B12 levels in patients with chronic gastritis significantly decreased, and the occurrence of peripheral neuropathy had a certain correlation. CAG and H. pylori infection are risk factors for vitamin B12 deficiency and peripheral neuropathy. When treating CAG, vitamin B12 supplementation can significantly reduce peripheral nervous system lesions. Therefore, the occurrence of peripheral neuropathy

Correlation between serum vitamin B12 level and peripheral neuropathy in atrophic gastritis.

Science.gov (United States)

Yang, Guo-Tao; Zhao, Hong-Ying; Kong, Yu; Sun, Ning-Ning; Dong, Ai-Qin

2018-03-28

To explore the correlation between serum vitamin B12 level and peripheral neuropathy in patients with chronic atrophic gastritis (CAG). A total of 593 patients diagnosed with chronic gastritis by gastroscopy and pathological examination from September 2013 to September 2016 were selected for this study. The age of these patients ranged within 18- to 75-years-old. Blood pressure, height and weight were measured in each patient, and the body mass index value was calculated. Furthermore, gastric acid, serum gastrin, serum vitamin and serum creatinine tests were performed, and peripheral nerve conduction velocity and Helicobacter pylori ( H. pylori ) were detected. In addition, the type of gastritis was determined by gastroscopy. The above factors were used as independent variables to analyze chronic gastritis with peripheral neuropathy and vitamin B12 deficiency risk factors, and to analyze the relationship between vitamin B12 levels and peripheral nerve conduction velocity. In addition, in the treatment of CAG on the basis of vitamin B12, patients with peripheral neuropathy were observed. Age, H. pylori infection, CAG, vitamin B9 and vitamin B12 were risk factors for the occurrence of peripheral nerve degeneration. Furthermore, CAG and H. pylori infection were risk factors for chronic gastritis associated with vitamin B12 deficiency. Serum vitamin B12 level was positively correlated with sensory nerve conduction velocity in the tibial nerve ( R = 0.463). After vitamin B12 supplementation, patients with peripheral neuropathy improved. Serum vitamin B12 levels in patients with chronic gastritis significantly decreased, and the occurrence of peripheral neuropathy had a certain correlation. CAG and H. pylori infection are risk factors for vitamin B12 deficiency and peripheral neuropathy. When treating CAG, vitamin B12 supplementation can significantly reduce peripheral nervous system lesions. Therefore, the occurrence of peripheral neuropathy associated with vitamin B12

Vitamin B-12 Concentrations in Breast Milk Are Low and Are Not Associated with Reported Household Hunger, Recent Animal-Source Food, or Vitamin B-12 Intake in Women in Rural Kenya.

Science.gov (United States)

Williams, Anne M; Chantry, Caroline J; Young, Sera L; Achando, Beryl S; Allen, Lindsay H; Arnold, Benjamin F; Colford, John M; Dentz, Holly N; Hampel, Daniela; Kiprotich, Marion C; Lin, Audrie; Null, Clair A; Nyambane, Geoffrey M; Shahab-Ferdows, Setti; Stewart, Christine P

2016-05-01

Breast milk vitamin B-12 concentration may be inadequate in regions in which animal-source food consumption is low or infrequent. Vitamin B-12 deficiency causes megaloblastic anemia and impairs growth and development in children. We measured vitamin B-12 in breast milk and examined its associations with household hunger, recent animal-source food consumption, and vitamin B-12 intake. In a cross-sectional substudy nested within a cluster-randomized trial assessing water, sanitation, hygiene, and nutrition interventions in Kenya, we sampled 286 women 1-6 mo postpartum. Mothers hand-expressed breast milk 1 min into a feeding after 90 min observed nonbreastfeeding. The Household Hunger Scale was used to measure hunger, food intake in the previous week was measured with the use of a food-frequency questionnaire (FFQ), and vitamin B-12 intake was estimated by using 24-h dietary recall. An animal-source food score was based on 10 items from the FFQ (range: 0-70). Breast milk vitamin B-12 concentration was measured with the use of a solid-phase competitive chemiluminescent enzyme immunoassay and was modeled with linear regression. Generalized estimating equations were used to account for correlated observations at the cluster level. Median (IQR) vitamin B-12 intake was 1.5 μg/d (0.3, 9.7 μg/d), and 60% of women consumed hunger prevalence was 27%; the animal-source food score ranged from 0 to 30 item-d/wk. Hunger and recent animal-source food and vitamin B-12 intake were not associated with breast milk vitamin B-12 concentrations. Maternal age was negatively associated with breast milk vitamin B-12 concentrations. Most lactating Kenyan women consumed less than the estimated average requirement of vitamin B-12 and had low breast milk vitamin B-12 concentrations. We recommend interventions that improve vitamin B-12 intake in lactating Kenyan women to foster maternal health and child development. The main trial was registered at clinicaltrials.gov as NCT01704105. © 2016

12 CFR Appendix B to Subpart B of... - Article 4A, Funds Transfers

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 2 2010-01-01 2010-01-01 false Article 4A, Funds Transfers B Appendix B to...—Article 4A, Funds Transfers Part 1—Subject Matter and Definitions Section 4A-101. Short Title This Article... otherwise provided in section 4A-108, this Article applies to funds transfers defined in section 4A-104...

Svaer vitamin B12-mangel hos spaedbørn brysternaeret af veganere

DEFF Research Database (Denmark)

Roed, Casper; Skovby, Flemming; Lund, Allan Meldgaard

2009-01-01

Weight loss and reduction of motor skills resulted in paediatric evaluation of a 10-month-old girl and a 12-month-old boy. Both children suffered form anaemia and delayed development due to vitamin B12 deficiency caused by strict maternal vegan diet during pregnancy and nursing. Therapy with cyan......Weight loss and reduction of motor skills resulted in paediatric evaluation of a 10-month-old girl and a 12-month-old boy. Both children suffered form anaemia and delayed development due to vitamin B12 deficiency caused by strict maternal vegan diet during pregnancy and nursing. Therapy...... with cyanocobalamin was instituted with remission of symptoms. Since infants risk irreversible neurologic damage following severe vitamin B12 deficiency, early diagnosis and treatment are mandatory. Vegan and vegetarian women should take vitamin B12 supplementation during the pregnancy and nursing period...

Vitamin B12 and eicosanoids in insects

International Nuclear Information System (INIS)

Wakayama, J.E.

1985-01-01

Vitamin B 12 was not detected in the house fly, Musca domestica, which apparently cannot interconvert propionate and succinate. In contrast, the termite readily interconverts succinate and methylmalonate, and contains high amounts of vitamin B 12 . The intestinal bacteria were the major source of vitamin B 12 in the termite, Coptotermes formosanus. The presence of arachidonic acid (20:4) and eicosatrienoic acid (20:3,n-6) at low levels in adult male and female house flies was demonstrated by chemical ionization-gas chromatography-mass spectrometry. After injection, over 80% of 20:4 was rapidly incorporated into the phospholipid (PL) fraction. Over 80% of the sequestered 20:4 was in the 2-position of PLs. The 20:4 was injected into the insect or was included in the diet prior to administration of [ 3 H] 20:4; large amounts of radioactivity were recovered in the triacylglycerol and free fatty acid fractions. Arachidonic acid (20:4) injected into house flies was rapidly converted to prostaglandins, and was also catabolized rapidly. Radiolabeled 20:4 injected into the hemolymph was incorporated into the reproductive tissues of male insects. About 2.1% of the total radioactivity from [ 3 H] 20:4 injected into males just prior to mating was transferred to females during mating

Radioactively labelled vitamin B12

International Nuclear Information System (INIS)

Charlton, J.C.; Lewis, A.

1976-01-01

A method is described for preparing radioactively labelled vitamin B 12 (cyanocobalamin) by reacting α-(5,6-dimethylbenzimidazolyl) hydrogenobamide with active (sup(57,58)Co) cobaltous ion. The latter may be in the form of cobaltous chloride or sulphate in aqueous or aqueous alcoholic medium. The reaction is effected by heating the reactants in darkness at pH 4 to 8. An excess of cyanide is added to convert the hydroxocobalamin formed to cyanocobalamin. (U.K.)

Analysis of IL12B gene variants in inflammatory bowel disease.

Directory of Open Access Journals (Sweden)

Jürgen Glas

Full Text Available BACKGROUND: IL12B encodes the p40 subunit of IL-12, which is also part of IL-23. Recent genome-wide association studies identified IL12B and IL23R as susceptibility genes for inflammatory bowel disease (IBD. However, the phenotypic effects and potential gene-gene interactions of IL12B variants are largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed IL12B gene variants regarding association with Crohn's disease (CD and ulcerative colitis (UC. Genomic DNA from 2196 individuals including 913 CD patients, 318 UC patients and 965 healthy, unrelated controls was analyzed for four SNPs in the IL12B gene region (rs3212227, rs17860508, rs10045431, rs6887695. Our analysis revealed an association of the IL12B SNP rs6887695 with susceptibility to IBD (p = 0.035; OR 1.15 [95% CI 1.01-1.31] including a trend for rs6887695 for association with CD (OR 1.41; [0.99-1.31], p = 0.066 and UC (OR 1.18 [0.97-1.43], p = 0.092. CD patients, who were homozygous C/C carriers of this SNP, had significantly more often non-stricturing, non-penetrating disease than carriers of the G allele (p = 6.8×10(-5; OR = 2.84, 95% CI 1.66-4.84, while C/C homozygous UC patients had less often extensive colitis than G allele carriers (p = 0.029; OR = 0.36, 95% CI 0.14-0.92. In silico analysis predicted stronger binding of the minor C allele of rs6887695 to the transcription factor RORα which is involved in Th17 differentiation. Differences regarding the binding to the major and minor allele sequence of rs6887695 were also predicted for the transcription factors HSF1, HSF2, MZF1 and Oct-1. Epistasis analysis revealed weak epistasis of the IL12B SNP rs6887695 with several SNPs (rs11889341, rs7574865, rs7568275, rs8179673, rs10181656, rs7582694 in the STAT4 gene which encodes the major IL-12 downstream transcription factor STAT4 (p<0.05 but there was no epistasis between IL23R and IL12B variants. CONCLUSIONS/SIGNIFICANCE: The IL12B SNP rs6887695

Peniciadametizine A, a Dithiodiketopiperazine with a Unique Spiro[furan-2,7'-pyrazino[1,2-b][1,2]oxazine] Skeleton, and a Related Analogue, Peniciadametizine B, from the Marine Sponge-Derived Fungus Penicillium adametzioides

Directory of Open Access Journals (Sweden)

Yang Liu

2015-06-01

Full Text Available Peniciadametizine A (1; a new dithiodiketopiperazine derivative possessing a unique spiro[furan-2,7'-pyrazino[1,2-b][1,2]oxazine] skeleton, together with a highly oxygenated new analogue, peniciadametizine B (2; as well as two known compounds, brasiliamide A (3; and viridicatumtoxin (4, were isolated and identified from Penicillium adametzioides AS-53, a fungus obtained from an unidentified marine sponge. The unambiguous assignment of the relative and absolute configuration for the spiro center C-2 of compound 1 was solved by the combination of NMR and ECD measurements with Density-Functional Theory (DFT conformational analysis and Time-Dependent Density-Functional Theory-Electronic Circular Dichroism (TDDFT-ECD calculations. The spiro[furan-2,7'-pyrazino[1,2-b][1,2]oxazine] skeleton of 1 has not been reported yet among natural products and the biosynthetic pathway for 1 and 2 was discussed. Compounds 1 and 2 showed inhibitory activity against the pathogenic fungus Alternaria brassicae.

Metabolism of dimethylphthalate by Micrococcus sp. strain 12B.

Science.gov (United States)

Eaton, R W; Ribbons, D W

1982-01-01

During growth of Micrococcus sp. strain 12B with dimethylphthalate, 4-carboxy-2-hydroxymuconate lactone (CHML, X) and 3,4-dihydroxyphthalate-2-methyl ester (XI) were isolated from culture filtrates. CHML is the lactone of intermediate 4-carboxy-2-hydroxymuconate (IX). Accumulation of XI which is not a substrate for 3,4-dihydroxyphthalate-2-decarboxylase in strain 12B afforded an easy access to the preparation of 3,4-dihydroxyphthalate. PMID:7085569

PODAAC-RSX12-L2B13

Data.gov (United States)

National Aeronautics and Space Administration — This dataset contains the RapidScat Level 2B 12.5km Version 1.3 science-quality ocean surface wind vectors, which are intended as a replacement and continuation of...

Vitamin B12 intake and status and cognitive function in elderly people.

Science.gov (United States)

Doets, Esmée L; van Wijngaarden, Janneke P; Szczecińska, Anna; Dullemeijer, Carla; Souverein, Olga W; Dhonukshe-Rutten, Rosalie A M; Cavelaars, Adrienne E J M; van 't Veer, Pieter; Brzozowska, Anna; de Groot, Lisette C P G M

2013-01-01

Current recommendations on vitamin B12 intake vary from 1.4 to 3.0 μg per day and are based on the amount needed for maintenance of hematologic status or on the amount needed to compensate obligatory losses. This systematic review evaluates whether the relation between vitamin B12 intake and cognitive function should be considered for underpinning vitamin B12 recommendations in the future. The authors summarized dose-response evidence from randomized controlled trials and prospective cohort studies on the relation of vitamin B12 intake and status with cognitive function in adults and elderly people. Two randomized controlled trials and 6 cohort studies showed no association or inconsistent associations between vitamin B12 intake and cognitive function. Random-effects meta-analysis showed that serum/plasma vitamin B12 (50 pmol/L) was not associated with risk of dementia (4 cohort studies), global cognition z scores (4 cohort studies), or memory z scores (4 cohort studies). Although dose-response evidence on sensitive markers of vitamin B12 status (methylmalonic acid and holotranscobalamin) was scarce, 4 of 5 cohort studies reported significant associations with risk of dementia, Alzheimer's disease, or global cognition. Current evidence on the relation between vitamin B12 intake or status and cognitive function is not sufficient for consideration in the development of vitamin B12 recommendations. Further studies should consider the selection of sensitive markers of vitamin B12 status. © The Author 2012. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Administrative Circulars Nos. 12 A and B (Rev. 1) – Education Fees

CERN Multimedia

HR Department

2007-01-01

Administrative Circulars Nos. 12 A and B (Rev. 1) – "Education Fees" are now available on the intranet site of the Human Resources Department: http://cern.ch/hr-docs/admincirc/admincirc.asp These Circulars cancel and replace Administrative Circular No.12 – "Education Grant" of April 1981. Copies will shortly be available in Departmental secretariats. Administrative Circular No. 12 A is applicable to staff members (except former "local staff"), fellows and paid associates, recruited before 1st January 2007. It may be noted that, at the initiative of the Human Resources Department, a number of important simplifications have been introduced. These cover in particular lump sum payments to compensate for accommodation, meals and journey expenses. Administrative Circular No. 12 B is applicable to staff members, fellows, scientific associates recruited as of 1st January 2007, as well as to former "local staff" recruited prior to this date. If you require any additional informa...

Administrative Circulars Nos. 12 A and B (Rev. 1) – Education Fees

CERN Multimedia

HR Department

2007-01-01

Administrative Circulars Nos. 12 A and B (Rev. 1) – "Education Fees" are now available on the intranet site of the Human Resources Department: http://https://hr-docs.web.cern.ch/hr-docs/admincirc/admincirc_fr.asp These circulars cancel and replace Administrative Circular No.12 – "Education Grant" of April 1981. Copies will shortly be available in Departmental secretariats. Administrative Circular No. 12 A is applicable to staff members (except former "local staff"), fellows and paid associates, recruited before 1st January 2007. It may be noted that, at the initiative of the Human Resources Department, a number of important simplifications have been introduced. These cover, in particular, lump sum payments to compensate for accommodation, meals and journey expenses. Administrative Circular No. 12 B is applicable to staff members, fellows, scientific associates recruited as of 1st January 2007, as well as to former "local staff" recruited prior to this date. If you requi...

Clinical value of serum vitamin B12 and folate in cerebrovascular disease

International Nuclear Information System (INIS)

Zhan Hao; Zhang Yongxue

2002-01-01

To study the clinical value of serum vitamin B 12 and folate in cerebrovascular disease, the concentration of serum vitamin B 12 and folate in 32 patients with cerebrovascular disease was measured by radioimmunoassay. The results showed that the changes in folate in all groups were not significant. The content of vitamin B 12 in multi-infarct dementia was markedly lower than that in cerebral infarction and cerebral hemorrhage. Moreover, the level of vitamin B 12 was lower in paralytic patients with muscular strength of grade 0-III. It can be concluded that serum vitamin B 12 level had association with intelligent disorder and paralytic degree

Electric-field-induced strain contributions in morphotropic phase boundary composition of (Bi{sub 1/2}Na{sub 1/2})TiO{sub 3}-BaTiO{sub 3} during poling

Energy Technology Data Exchange (ETDEWEB)

Khansur, Neamul H.; Daniels, John E. [School of Materials Science and Engineering, UNSW Australia, New South Wales 2052 (Australia); Hinterstein, Manuel [School of Materials Science and Engineering, UNSW Australia, New South Wales 2052 (Australia); Institute for Applied Materials, Karlsruhe Institute for Technology, P.O. Box 3640, 76021 Karlsruhe (Germany); Wang, Zhiyang [School of Materials Science and Engineering, UNSW Australia, New South Wales 2052 (Australia); The Australian Synchrotron, Clayton, Victoria 3168 (Australia); Groh, Claudia [Institute of Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, 64287 Darmstadt (Germany); Jo, Wook [School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919 (Korea, Republic of)

2015-12-14

The microscopic contributions to the electric-field-induced macroscopic strain in a morphotropic 0.93(Bi{sub 1/2}Na{sub 1/2}TiO{sub 3})−0.07(BaTiO{sub 3}) with a mixed rhombohedral and tetragonal structure have been quantified using full pattern Rietveld refinement of in situ high-energy x-ray diffraction data. The analysis methodology allows a quantification of all strain mechanisms for each phase in a morphotropic composition and is applicable to use in a wide variety of piezoelectric compositions. It is shown that during the poling of this material 24%, 44%, and 32% of the total macroscopic strain is generated from lattice strain, domain switching, and phase transformation strains, respectively. The results also suggest that the tetragonal phase contributes the most to extrinsic domain switching strain, whereas the lattice strain primarily stems from the rhombohedral phase. The analysis also suggests that almost 32% of the total strain is lost or is a one-time effect due to the irreversible nature of the electric-field-induced phase transformation in the current composition. This information is relevant to on-going compositional development strategies to harness the electric-field-induced phase transformation strain of (Bi{sub 1/2}Na{sub 1/2})TiO{sub 3}-based lead-free piezoelectric materials for actuator applications.

Experimental search for second-class currents. Beta-ray angular distributions from aligned nuclei /sup 12/B and /sup 12/N

Energy Technology Data Exchange (ETDEWEB)

Sugimoto, K; Minamisono, T; Nojiri, Y; Masuda, Y [Osaka Univ., Toyonaka (Japan). Lab. of Nuclear Studies

1978-01-01

The ..beta..-energy dependent angular distributions, W(theta) asymptoticaly equals 1 +- P(1 + ..cap alpha../sub +-/E)P/sub 1/(cos theta) + A..cap alpha../sub +-/EP/sub 2/(cos theta), from the aligned nuclei /sup 12/B and /sup 12/N have been measured. Positive A/sup +/ and negative A/sup -/ alignments were successively produced, by use of NMR, after every other production period of polarized nuclei through nuclear reactions; A/sup +/ - A/sup -/ asymptoticaly equals 0.26 for /sup 12/B and /sup +/A/sup +/ - A/sup - +/ asymptoticaly equals 0.55 for /sup 12/N with p asymptoticaly equals 0. The results are ..cap alpha../sub -/(/sup 12/B) = 0.02/sub 5/ +- 0.03/sub 4/%/MeV, /sup +/..cap alpha../sub +/(/sup 12/N)/sup +/ = 0.27/sub 7/ +- 0.05/sub 2/%/MeV, and ..cap alpha../sub -/ - ..cap alpha../sub +/ = 0.30/sub 2/ +- 0.06/sub 2/%/MeV assuming ..cap alpha../sub +/<0. In comparison with available data for CVC test in the mass-12 triad and theoretical predictions, the present ..cap alpha../sub -/ - ..cap alpha../sub +/ value is consistent within 20% level with predictions of the CVC theory and with absence of second-class induced-tensor currents.

SF12: Stata module to alidate sf12 input and calculate sf12 version 2 t scores

DEFF Research Database (Denmark)

2015-01-01

sf12 takes 12 variables in correct order (i1 i2a i2b i3a i3b i4a i4b i5 i6a i6b i6c i7), validate the variables with respect to sf12 requirements. Only rows that are correct are used for calculating the sf12 t scores....

Vitamin B12 Deficiency in Persons with Intellectual Disability in a Vegetarian Residential Care Community

Directory of Open Access Journals (Sweden)

Mohammed Morad

2005-01-01

Full Text Available The goal of this study was to determine the prevalence of vitamin B12 deficiency among intellectually disabled persons in a vegetarian remedial community in Israel. In this community, 47 individuals with intellectual disability (ID live in 7 enlarged families in a kibbutz style agricultural setting. These 47 individuals and 17 of their caregivers were screened for vitamin B12 deficiency. There were 25.5% of the disabled vs. 11.8% of the caregivers found to have levels of vitamin B12 lower than 157 pg/ml. It is concluded that persons with ID in this vegetarian residential care community seemed to be at a higher risk for vitamin B12 deficiency.

Thermodynamic consideration and ground-state search of icosahedral boron subselenide B12(B1-xSex) 2 from a first-principles cluster expansion

Science.gov (United States)

Ektarawong, A.

2018-05-01

The phase stability of icosahedral boron subselenide B12(B1-xSex) 2 , where 0.5 ≤x ≤1 , is explored using a first-principles cluster expansion. The results shows that, instead of a continuous solid solution, B12(B1-xSex) 2 is thermodynamically stable as an individual line compound at the composition of B9.5Se . The ground-state configuration of B9.5Se is represented by a mixture of B12(Se-Se), B12(B-Se), and B12(Se-B) with a ratio of 1:1:1, where they form a periodic A B C A B C ⋯ stacking sequence of B12(Se-Se), B12(B-Se), and B12(Se-B) layers along the c axis of the hexagonal conventional unit cell. The structural and electronic properties of the ground-state B9.5Se are also derived and discussed. By comparing the derived ground-state properties of B9.5Se to the existing experimental data of boron subselenide B˜13Se , I proposed that the as-synthesized boron subselenide B˜13Se , as reported in the literature, has the actual composition of B9.5Se .

vitamin b12 levels in patients with type 2 diabetes mellitus

African Journals Online (AJOL)

is involved in DNA synthesis, fatty acid metabolism. VITAMIN B12 ..... concentrations of homocysteine, folate and vitamin B12 in ... and folic acid: a cross-sectional study in patients with type 2 ... pregnant women with polycystic ovary syndrome.

Current superimposition variable flux reluctance motor with 8 salient poles

Science.gov (United States)

Takahara, Kazuaki; Hirata, Katsuhiro; Niguchi, Noboru; Kohara, Akira

2017-12-01

We propose a current superimposition variable flux reluctance motor for a traction motor of electric vehicles and hybrid electric vehicles, which consists of 10 salient poles in the rotor and 12 slots in the stator. However, iron losses of this motor in high rotation speed ranges is large because the number of salient poles is large. In this paper, we propose a current superimposition variable flux reluctance motor that consists of 8 salient poles and 12 slots. The characteristics of the 10-pole-12-slot and 8-pole-12-slot current superimposition variable flux reluctance motors are compared using finite element analysis under vector control.

Current superimposition variable flux reluctance motor with 8 salient poles

Directory of Open Access Journals (Sweden)

Takahara Kazuaki

2017-12-01

Full Text Available We propose a current superimposition variable flux reluctance motor for a traction motor of electric vehicles and hybrid electric vehicles, which consists of 10 salient poles in the rotor and 12 slots in the stator. However, iron losses of this motor in high rotation speed ranges is large because the number of salient poles is large. In this paper, we propose a current superimposition variable flux reluctance motor that consists of 8 salient poles and 12 slots. The characteristics of the 10-pole-12-slot and 8-pole-12-slot current superimposition variable flux reluctance motors are compared using finite element analysis under vector control.

Analysis of IL12B Gene Variants in Inflammatory Bowel Disease

Science.gov (United States)

Wagner, Johanna; Olszak, Torsten; Fries, Christoph; Tillack, Cornelia; Friedrich, Matthias; Beigel, Florian; Stallhofer, Johannes; Steib, Christian; Wetzke, Martin; Göke, Burkhard; Ochsenkühn, Thomas; Diegelmann, Julia; Czamara, Darina; Brand, Stephan

2012-01-01

Background IL12B encodes the p40 subunit of IL-12, which is also part of IL-23. Recent genome-wide association studies identified IL12B and IL23R as susceptibility genes for inflammatory bowel disease (IBD). However, the phenotypic effects and potential gene-gene interactions of IL12B variants are largely unknown. Methodology/Principal Findings We analyzed IL12B gene variants regarding association with Crohn's disease (CD) and ulcerative colitis (UC). Genomic DNA from 2196 individuals including 913 CD patients, 318 UC patients and 965 healthy, unrelated controls was analyzed for four SNPs in the IL12B gene region (rs3212227, rs17860508, rs10045431, rs6887695). Our analysis revealed an association of the IL12B SNP rs6887695 with susceptibility to IBD (p = 0.035; OR 1.15 [95% CI 1.01–1.31] including a trend for rs6887695 for association with CD (OR 1.41; [0.99–1.31], p = 0.066) and UC (OR 1.18 [0.97–1.43], p = 0.092). CD patients, who were homozygous C/C carriers of this SNP, had significantly more often non-stricturing, non-penetrating disease than carriers of the G allele (p = 6.8×10−5; OR = 2.84, 95% CI 1.66–4.84), while C/C homozygous UC patients had less often extensive colitis than G allele carriers (p = 0.029; OR = 0.36, 95% CI 0.14–0.92). In silico analysis predicted stronger binding of the minor C allele of rs6887695 to the transcription factor RORα which is involved in Th17 differentiation. Differences regarding the binding to the major and minor allele sequence of rs6887695 were also predicted for the transcription factors HSF1, HSF2, MZF1 and Oct-1. Epistasis analysis revealed weak epistasis of the IL12B SNP rs6887695 with several SNPs (rs11889341, rs7574865, rs7568275, rs8179673, rs10181656, rs7582694) in the STAT4 gene which encodes the major IL-12 downstream transcription factor STAT4 (p<0.05) but there was no epistasis between IL23R and IL12B variants. Conclusions/Significance The IL12B SNP rs6887695 modulates

Vitamin B@d12@@ concentrations in Mandovi and Zuari estuaries

Digital Repository Service at National Institute of Oceanography (India)

De; Rajendran, A.

Bioassay method using @iCyclotella nana@@ (clone 13) was employed for the estimation of Vitamin B@d12@@ in Mandovi and Zuari estuaries. At the mouth of the Mandovi estuary, B@d12@@ concentration varied between 0.38 and 7.0 ng/l in surface water...

RSCAT_LEVEL_2B_OWV_COMP_12_V1.1:1

Data.gov (United States)

National Aeronautics and Space Administration — This dataset contains the RapidScat Level 2B 12.5km Version 1.1 science-quality ocean surface wind vectors. The Level 2B wind vectors are binned on a 12.5 km Wind...

Prevalence of Vitamin B12 deficiency in patients of type 2 diabetes ...

African Journals Online (AJOL)

Conclusion: Our study demonstrated significantly high prevalence of vitamin B12 deficiency in patients treated with metformin with significant effect of dose and duration of metformin use on B12 levels. Physicians must recognize this important fact and screen diabetics on metformin therapy for underlying B12 deficiency.

Observation of non-statistical structures in the excitation function of the reaction 10B(14N,12C)12C under extreme forward angles

International Nuclear Information System (INIS)

Klauss, E.U.

1984-01-01

In the present thesis the excitation functions of the reaction 10 B( 14 N, 12 C) 12 C to the ground states, the first excited state at 4.43 MeV (Jsup(π) = 2 1 + ) of a 12 C residual nucleus, and to the double excitation of ejectile and residue nucleus to the 4.43 state are studied. The measurements were performed in an energy range 13MeV 14 N) 0 (in the c.m. system). By a fitting to elastic scattering data the optical potential for 10 B+ 14 N was determined. With this potential it was tried by means of Hauser-Feshbach calculations to calculate the cross sections of the reaction 10 B( 14 N, 12 C) 12 C. The strong 16 + resonance and indications of 18 + in the excitation function of the reaction 10 B( 14 N, 12 Csub(g.s.)) 12 Csub(g.s.) should be pronounced. An unexpected large cross section was observed in the reaction 10 B( 14 N, 12 Csub(g.s.)) 12 C(4 1 + ). This is considered as a further indication to the strong contribution of a direct process. (orig./HSI) [de

Plasma Folate and Vitamin B12 Levels in Patients with Hepatocellular Carcinoma

Directory of Open Access Journals (Sweden)

Lian-Hua Cui

2016-06-01

Full Text Available Folate and vitamin B12 involved in the one-carbon metabolism may play a key role in carcinogenesis and progression of hepatocellular carcinoma (HCC through influencing DNA integrity. The purpose of this study is to evaluate the association of plasma folate and vitamin B12 levels with HCC in a case-control study on 312 HCC patients and 325 cancer-free controls. Plasma concentrations of folate and vitamin B12 in all the subjects were measured by electrochemiluminescence immunoassay. Meanwhile, the information of HCC patients’ clinical characteristics including tumor-node-metastasis (TNM stage, tumor size and tumor markers were collected. The patients of HCC had significantly lower folate levels than those of controls; there was no significant difference in the mean of plasma vitamin B12 levels. We also observed an inverse association between the levels of plasma folate and HCC: the adjusted odds ratios (OR (95% confidence intervals (CI of HCC from the highest to lowest quartile of folate were 0.30 (0.15–0.60, 0.33 (0.17–0.65, and 0.19 (0.09–0.38. Compared to the subjects in the lowest quartile of plasma vitamin B12, only the subjects in the highest quartile of vitamin B12 exhibited a significant positive relationship with HCC, the adjusted OR was 2.01 (95% CI, 1.02–3.98. HCC patients with Stage III and IV or bigger tumor size had lower folate and higher vitamin B12 levels. There was no significant difference in the mean plasma folate levels of the HCC cases in tumor markers status (AFP, CEA and CA19-9 levels, whereas patients with higher CEA or CA19-9 levels retained significantly more plasma vitamin B12 than those with normal-CEA or CA19-9 level. In conclusion, plasma folate and vitamin B12 levels could be associated with HCC, and might be used as predictors of clinical characteristics of HCC patients. However, further prospective studies are essential to confirm the observed results.

Dipstick based immunochemiluminescence biosensor for the analysis of vitamin B12 in energy drinks: A novel approach

International Nuclear Information System (INIS)

Selvakumar, L.S.; Thakur, M.S.

2012-01-01

Graphical abstract: (a) Schematic representation of immunochemiluminescence based dipstick technique for detection of vitamin B 12 . (b) Enzymatic dephosphorylation of dioxetane by alkaline phosphatase. Highlights: ► Dipstick based immunochemiluminescence biosensor proposed for vitamin B 12 analysis. ► The limit of detection of vitamin B 12 is 1 ng mL −1 and applied in energy drinks. ► Chemiluminescence generated was inversely proportional to vitamin B 12 concentration. ► Chemiluminescence analytical procedure was compared with ELISA. ► Alkaline phosphatase was stable chemiluminescent enzyme than Horse Radish Peroxidase. - Abstract: In this article, we describe a dipstick based immunochemiluminescence (immuno-CL) biosensor for the detection of vitamin B 12 in energy drinks. The method is a direct competitive type format involving the immobilization of vitamin B 12 antibody on nitrocellulose membrane (NC) followed by treatment with vitamin B 12 and vitamin B 12 –alkaline phosphatase conjugate to facilitate the competitive binding. The dipstick was further treated with substrate disodium 2-chloro-5-(4-methoxyspiro {1,2-dioxetane-3,2¢-(5¢-chloro)tricyclo[3.3.1.13,7]decan}-4-yl)-1-phenyl phosphate (CDP-Star) to generate chemiluminescence (CL). The number of photons generated was inversely proportional to the vitamin B 12 concentration. After systematic optimization, the limit of detection was 1 ng mL −1 . The coefficient of variation was below 0.2% for both intra- and inter-assay precision. Vitamin B 12 was extracted from energy drinks with recovery ranged from 90 to 99.4%. Two different energy drinks samples were analyzed, and a good correlation was observed when the data were compared with a reference enzyme linked immuno sorbent assay (ELISA) method. The developed method is suitable for an accurate, sensitive, and high-throughput screening of vitamin B 12 in energy drinks samples. The dipstick technique based on immuno-CL is suitable for the

Vitamin B12 deficiency - a major cause of megaloblastic anaemia in patients attending a tertiary care hospital

International Nuclear Information System (INIS)

Iqbal, S.P.; Kakepoto, G.N.; Iqbal, S.P.

2009-01-01

Folate and vitamin B12 deficiencies have been known to cause megaloblastic anaemia. Since the deficiencies of these two vitamins are very common in Pakistani population, it would be imperative to investigate their role in causing megaloblastic anaemia. The objective of this study was to find out the contribution of folate and vitamin B12 deficiencies in causing megaloblastic anaemia in our patient population. Methods: In this retrospective cohort study, clinical records of 220 patients (101 females and 119 males with an age range of 1 - 80 years) who presented themselves with macrocytic anaemia at the Aga Khan University Hospital were collected. Data pertaining to complete blood count and serum levels of folate and vitamin B12 were analysed. Results: The mean haemoglobin (Hb) level was 6.8 +- 0.2 gm/dl. Sixty-nine percent of the patients had severe anaemia (Hb<8 gm/dl). Mean +- SEM values of haemoglobin, serum folate and serum B12 were not significantly different between males and females (Hb 6.4 +- 0.3 gm/dl vs 6.3 +- 0.3 gm/dl; folate 6.9 +- 0.8 mu g/ml vs 7.8 +- 1 mu g/ml; B12 259 +- 65 mu g/ml vs 225 +- 45 mu g/ml, respectively). Linear regression analysis showed that serum folate was inversely related with the mean corpuscular volume (MCV, p=0.04). Spearman's correlation analysis indicated an inverse mild association between MCV and serum folate (correlation coefficient= -0.18). Folate deficiency was 43.4%, while vitamin B12 deficiency was 78.5% in these patients. Seventy-one percent of folate-deficient patients had vitamin B12 deficiency as well, while 26.1% of patients with B12 deficiency had a co-occurrence of folate deficiency. Conclusion: Vitamin B12 deficiency appears to be the major factor leading to megaloblastic anaemia in our study population. Inadequate dietary intake, over-cooking of our food and poor absorption might be contributing to high prevalence of vitamin B12 deficiency in this population. (author)

Stability of added and in situ-produced vitamin B12 in breadmaking.

Science.gov (United States)

Edelmann, Minnamari; Chamlagain, Bhawani; Santin, Marco; Kariluoto, Susanna; Piironen, Vieno

2016-08-01

Vitamin B12 exists naturally in foods of animal origin and is synthesised only by certain bacteria. New food sources are needed to ensure vitamin B12 intake in risk groups. This study aimed to investigate the stability of added cyanocobalamin (CNCbl, chemically modified form) and hydroxocobalamin (OHCbl, natural form) and in situ-synthesised vitamin B12 in breadmaking. Samples were analysed both with a microbiological (MBA) and a liquid chromatographic (UHPLC) method to test applicability of these two methods. Proofing did not affect CNCbl and OHCbl levels. By contrast, 21% and 31% of OHCbl was lost in oven-baking steps in straight- and sponge-dough processes, respectively, whereas CNCbl remained almost stable. In sourdough baking, 23% of CNCbl and 44% of OHCbl were lost. In situ-produced vitamin B12 was almost as stable as added CNCbl and more stable than OHCbl. The UHPLC method showed its superiority to the MBA in determining the active vitamin B12. Copyright © 2016. Published by Elsevier Ltd.

The Singer's and the Clinician's Perspective on Vitamin B12 Treatment for Vocal Benefits.

Science.gov (United States)

Shoffel-Havakuk, Hagit; Lava, Christian X; Hapner, Edie R; O'Dell, Karla; Reder, Lindsay; Johns, Michael M

2018-01-03

There is a belief among vocalists that there are voice benefits from vitamin B 12 treatment. Yet there are no previous reports regarding vitamin B 12 effects on voice. To assess the prevalence of vitamin B 12 use among singers and their beliefs regarding vitamin B 12 therapy. Anonymous online survey administered to singers, singing-teachers, speech-language pathologists, and laryngologists. A total of 192 participants completed the surveys; 128 singers (68 singing-teachers, 30 speech-language pathologists) and 64 laryngologists. Among singers, 12% have perceived voice benefits from vitamin B 12 treatment taken for any reason. Four percent used vitamin B 12 for voice benefits; all perceived voice benefits as a result. The leading voice benefits were improved stamina, reduced effort, confidence, and control. Nineteen percent of the singers would recommend vitamin B 12 treatment to a friend; 15% of the singing-teachers would recommend it to a student. Among laryngologists, 33% been asked by a singer to prescribe vitamin B 12 for voice benefits; 9% have prescribed it in the past. Yet only 3% would you recommend it to a patient. When asked "Do you believe vitamin B 12 therapy improves vocal performance?" 31% of the singers responded "Yes," compared with none in the laryngologists. When asked "Do you think the singing community believes vitamin B 12 therapy improves vocal performance?" 26% of the singers responded "Yes," compared with 53% of the laryngologists (P = 0.0002). There is a discrepancy between the singers' and the laryngologists' beliefs regarding vocal benefits perceived by vitamin B 12 . Blinded randomized trials are required to verify or refute this belief. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Crystal and molecular structure of 6,9-bis(trimethylamine)-nido-decarborane(12) B10H12[N(CH3)3]2

International Nuclear Information System (INIS)

Polyanskaya, T.M.; Volkov, V.V.

1989-01-01

The spatial structure of 6.9-bis(trimethylamine)-nido-decarborane (12) is established on the basis of X-ray diffraction analysis. Crystals are rhombic, a = 12.619, b = 11.804, c = 11.058A, Z=4, sp. gr. P na 2 1 . The structure is of molecular type. Main geometrical parameters of the molecule are: symmetry - C1, interatomic distances - B-B 1.66-1.90, B-N 1.61, N-C 1.50 A, angles - BBB 55.0-66.5, CNC 108, BBN 119.5 deg. The (B 10 H 12 ) cluster size between B(6) and B(9) is 3.30 A. Increase approximately by 0.1 A of lengths of external bonds B-B in comparison with internal ones and tightening approximately by 3 deg of valent angles BBB at external atoms of boron also in comparison with internal ones are observed

NutriPhone: vitamin B12 testing on your smartphone (Conference Presentation)

Science.gov (United States)

Lee, Seoho; O'Dell, Dakota; Hohenstein, Jessica; Colt, Susannah; Mehta, Saurabh; Erickson, David

2016-03-01

Vitamin B12 deficiency is the leading cause of cognitive decline in the elderly and is associated with increased risks of several acute and chronic conditions including anemia. The deficiency is prevalent among the world population, most of whom are unaware of their condition due to the lack of a simple diagnostics system. Recent advancements in the smartphone-enabled mobile health can help address this problem by making the deficiency tests more accessible. Previously, our group has demonstrated the NutriPhone, a smartphone platform for the accurate quantification of vitamin D levels. The NutriPhone technology comprises of a disposable test strip that performs a colorimetric reaction upon collecting a sample, a reusable accessory that interfaces with the smartphone camera, and a smartphone app that stores the algorithm for analyzing the test-strip reaction. In this work, we show that the NutriPhone can be expanded to measure vitamin B12 concentrations by developing a lateral flow assay for B12 that is compatible with our NutriPhone system. Our novel vitamin B12 assay incorporates blood sample processing and key reagent storage on-chip, which advances it into a sample-in-answer-out format that is suitable for point-of-care diagnostic applications. In order to enable the detection of pM levels of vitamin B12 levels, silver amplification of the initial signal is used within the total assay time of less than 15 minutes. We demonstrate the effectiveness of our NutriPhone system by deploying it in a resource-limited clinical setting in India where it is used to test tens of participants for vitamin B12 deficiency.

Low vitamin B12 levels among newly-arrived refugees from Bhutan, Iran and Afghanistan: a multicentre Australian study.

Directory of Open Access Journals (Sweden)

Jill Benson

Full Text Available BACKGROUND: Vitamin B12 deficiency is prevalent in many countries of origin of refugees. Using a threshold of 5% above which a prevalence of low Vitamin B12 is indicative of a population health problem, we hypothesised that Vitamin B12 deficiency exceeds this threshold among newly-arrived refugees resettling in Australia, and is higher among women due to their increased risk of food insecurity. This paper reports Vitamin B12 levels in a large cohort of newly arrived refugees in five Australian states and territories. METHODS: In a cross-sectional descriptive study, we collected Vitamin B12, folate and haematological indices on all refugees (n = 916; response rate 94% of eligible population who had been in Australia for less than one year, and attended one of the collaborating health services between July 2010 and July 2011. RESULTS: 16.5% of participants had Vitamin B12 deficiency (<150 pmol/L. One-third of participants from Iran and Bhutan, and one-quarter of participants from Afghanistan had Vitamin B12 deficiency. Contrary to our hypothesis, low Vitamin B12 levels were more prevalent in males than females. A higher prevalence of low Vitamin B12 was also reported in older age groups in some countries. The sensitivity of macrocytosis in detecting Vitamin B12 deficiency was only 4.6%. CONCLUSION: Vitamin B12 deficiency is an important population health issue in newly-arrived refugees from many countries. All newly-arrived refugees should be tested for Vitamin B12 deficiency. Ongoing research should investigate causes, treatment, and ways to mitigate food insecurity, and the contribution of such measures to enhancing the health of the refugee communities.

Human intrinsic factor expression for bioavailable vitamin B₁₂ enrichment in microalgae

DEFF Research Database (Denmark)

Lima, Serena; Webb, Conner L.; Deery, Evelyne

2018-01-01

Dietary supplements and functional foods are becoming increasingly popular complements to regular diets. A recurring ingredient is the essential cofactor vitamin B12(B12). Microalgae are making their way into the dietary supplement and functional food market but do not produce B12, and their B12 ...... that is suitable for vegetarians and, potentially, more bioavailable for humans....

Effects of γ-irradiation and cooking on vitamins B6 and B12 in grass prawns (Penaeus monodon)

International Nuclear Information System (INIS)

Hau, L.-B.; Liew, M.-S.

1993-01-01

The effects of radiation doses, irradiation temperature and a combined treatment of irradiation and cooking on the vitamin B 6 and B 12 contents of grass prawns have been studied. Grass prawns were irradiated at refrigerated (4 o C) or frozen (-20 o C) temperatures with different doses. A domestic cooling procedure was followed after irradiation. The changes in vitamins B 6 and B 12 of both raw and cooked grass prawns were evaluated. Results showed no significant changes of vitamin B 6 and B 12 in grass prawns with a radiation dose up to 7 kGy at either 4 o C or -20 o C. Irradiation at 4 o C caused more destruction of vitamin B 12 but not vitamin B 6 than did irradiation at -20 o C in grass prawns. There was significant destruction of both vitamins B 6 and B 12 in unirradiated samples during cooking. The introduction of the irradiation process before cooking had no effect on either vitamin. These results indicate that the loss of vitamins B 6 and B 12 in the combined treatments was caused mainly by thermal destruction. (author)

Diffusion of Vitamin B12 Across a Mesoporous Metal Organic Framework

Directory of Open Access Journals (Sweden)

Veronica Valencia

2013-01-01

Full Text Available We measure the rate of uptake and the rate of release of a Vitamin B12 solution (dissolved in water at 2 different temperatures (room temperature and 37°C by the mesoporous metal organic framework TbMOF-100 at 1-hour intervals using a spectrophotometer. Using the Beer-Lambert law, we calculate the concentration of the stock solution based on the absorbance values obtained with the spectrophotometer. These values allow for the quantification of the initial rate of uptake and the rate of uptake at a random incubation time of the Vitamin B12 by the TbMOF-100. We also calculate the value of the coefficient of diffusion for this 2-phase system using Fick’s laws of diffusion.

NutriPhone: a mobile platform for low-cost point-of-care quantification of vitamin B12 concentrations.

Science.gov (United States)

Lee, Seoho; O'Dell, Dakota; Hohenstein, Jess; Colt, Susannah; Mehta, Saurabh; Erickson, David

2016-06-15

Vitamin B12 is necessary for formation of red blood cells, DNA synthesis, neural myelination, brain development, and growth. Vitamin B12 deficiency is often asymptomatic early in its course; however, once it manifests, particularly with neurological symptoms, reversal by dietary changes or supplementation becomes less effective. Access to easy, low cost, and personalized nutritional diagnostics could enable individuals to better understand their own deficiencies as well as track the effects of dietary changes. In this work, we present the NutriPhone, a mobile platform for the analysis of blood vitamin B12 levels in 15 minutes. The NutriPhone technology comprises of a smartphone accessory, an app, and a competitive-type lateral flow test strip that quantifies vitamin B12 levels. To achieve the detection of sub-nmol/L physiological levels of vitamin B12, our assay incorporates an innovative "spacer pad" for increasing the duration of the key competitive binding reaction and uses silver amplification of the initial signal. We demonstrate the efficacy of our NutriPhone system by quantifying physiologically relevant levels of vitamin B12 and performing human trials where it was used to accurately evaluate blood vitamin B12 status of 12 participants from just a drop (~40 μl) of finger prick blood.

Study of vitamin B/sub 12/ absorption by a whole-body counter (plastic). I. The fundamental considerations

Energy Technology Data Exchange (ETDEWEB)

Morishita, R; Furumatsu, C [Kyoto Univ. (Japan). Faculty of Medicine

1975-08-01

An absorption test of vitamin B/sub 12/ was studied by using the whole body spectrometer (plastic) in a low background room. Four plastic scintillation probes were set under the bed. Each plastic scintillation probe contains a 50x50x15 cm/sup 3/ scintillator and four photomultiplier tubes. Each subject was measured in supine and prone positions and the mean was used. Measurement was made before (body background), 35 minutes after (100%), and again 7 days after the oral administration of 0.17 to 0.2 ..mu..g(below 0.16 ..mu..Ci) /sup 60/Co-B/sub 12/ or of 0.2 ..mu..g(below 0.4 ..mu..Ci) /sup 58/Co-B/sub 12/. No meal or medicine was given at least 2 hours after the oral uptake of radioactive B/sub 12/. To correct for the radioactive decay and any counter instability, all measurements were corrected using a standard source. The results of B/sub 12/ absorption were expressed as the retention percentage of the labeled B/sub 12/ within the body on the seventh day. Present methods of measuring intestinal absorption of radioactive B/sub 12/ include measurements of the radioactivity (1) in the feces, (2) in the urine, (3) in the serum, or over the liver projection. While all these methods give clinically valuable results, B/sub 12/ absorption is determined most accurately by direct measurement of the amount remaining in the body with a whole-body counter after the unabsorbed radio-B/sub 12/ is excreted in the feces. It is more quantitative and simpler than the Schilling test and permits the measurement ofradioactive B/sub 12/ at a considerably lower level than the maximum permissible body burdens.

Low vitamin B-12 status and risk of cognitive decline in older adults

DEFF Research Database (Denmark)

Clarke, Robert; Birks, Jacqueline; Nexo, Ebba

2007-01-01

remained significant. CONCLUSIONS: Low vitamin B-12 status was associated with more rapid cognitive decline. Randomized trials are required to determine the relevance of vitamin B-12 supplementation for prevention of dementia. Udgivelsesdato: 2007-Nov......BACKGROUND: Elevated total homocysteine (tHcy) concentrations have been associated with cognitive impairment, but it is unclear whether low vitamin B-12 or folate status is responsible for cognitive decline. OBJECTIVE: We examined the associations of cognitive decline with vitamin B-12 and folate...... status in a longitudinal cohort study performed from 1993 to 2003 in Oxford, United Kingdom. DESIGN: Cognitive function was assessed with the Mini-Mental State Examination on >/=3 occasions during 10 y and related to serum concentrations of vitamin B-12, holotranscobalamin (holoTC), tHcy, methylmalonic...

Study of the ${\\beta}$-decay of $^{12}$B

CERN Multimedia

2002-01-01

We propose to study the ${\\beta}$-decay of $^{12}$B with a modern segmented Si-detector array to get new and much improved information on states in $^{12}$C above the ${\\alpha}$-threshold. These states mainly decay into final states of three ${\\alpha}$-particles and their study therefore is a challenge for nuclear spectroscopy. The properties of these states is of high current interest for nuclear astrophysics and for the nuclear many-body problem in general. We ask for a total of 15 shifts.

Spectroscopic investigations of the B12-binding subunit of glutamate mutase: refined solution structure of the complex with the B12-nucleotide, dynamics and binding studies with two corrinoid cofactors

International Nuclear Information System (INIS)

Eichmueller, C.

2002-06-01

Glutamate mutase is an enzyme isolated from Clostridium tetanomorphum and Clostridium cochlearum. It catalyses the reversible rearrangement of (2S)-glutamate to (2S,3S)-3-methylaspartate. Coenzyme B12 is required as cofactor for an active enzyme, as the first step of the catalytic cycle is the homolytic cleavage of the cobalt-carbon bond. The rearrangement itself follows a radical mechanism. The holoenzyme is an alpha2beta2 heterotetramer containing two identical catalytic and two B12 binding domains, as well as two coenzyme B12 molecules. The smaller B12 binding domain from Clostridium tetanomorphum, MutS, is known to bind coenzyme B12 in its unusual 'base-off' form. A conserved histidine residue coordinates to the cobalt atom instead of the normally coordinated dimethlybenzimidole in free coenzyme B12. In the present work a refined solution structure of the B12 binding subunit from Clostridium tetanomorphum (MutS) in complex with the detached nucleotide loop of coenzyme B12 has been determined using nuclear magnetic resonance. The found topology is almost identical to the crystal structure of glutamate mutase from C.cochlearum [Reitzer et al., 1999], in contrast to the solution structures obtained for apo-MutS [Hoffmann et al., 2001; Tollinger et al., 1998] and apo-GlmS [Hoffmann et al., 1999]. In these two structures a helix at one side of the B12 nucleotide loop binding pocket is mostly unstructured and shows motions on a microsecond to millisecond timescale. The previously found stabilization of this helix upon B12-nucleotide binding [Tollinger et al., 2001] was confirmed using 13C and 15N labeled MutS. Some differences are found in the structure of the binding pocket and the bound nucleotide loop compared to the crystal structure. This indicates that additional conformational changes occur upon binding of the corrin ring of coenzyme B12. NMR-relaxation measurements performed on apo-MutS showed interesting slow molecular motions not only in the mainly

Evaluation of serum Vitamin B12 level and related nutritional status ...

African Journals Online (AJOL)

2016-03-29

Mar 29, 2016 ... This study was aimed to investigate the association between serum. Vitamin B12 ... Consumption of certain types of food contributes to increase vitB12 level. Key words: ... nutritional status among apparently healthy obese.

TRANSIT TIMING VARIATION MEASUREMENTS OF WASP-12b AND QATAR-1b: NO EVIDENCE OF ADDITIONAL PLANETS

Energy Technology Data Exchange (ETDEWEB)

Collins, Karen A.; Stassun, Keivan G. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Kielkopf, John F. [Department of Physics and Astronomy, University of Louisville, Louisville, KY 40292 (United States)

2017-02-01

WASP-12b and Qatar-1b are transiting hot Jupiters for which previous works have suggested the presence of transit timing variations (TTVs) indicative of additional bodies in these systems—an Earth-mass planet in WASP-12 and a brown-dwarf mass object in Qatar-1. Here, we present 23 new WASP-12b and 18 new Qatar-1b complete (or nearly complete) transit observations. We perform global system fits to all of our light curves for each system, as well as RV and stellar spectroscopic parameters from the literature. The global fits provide refined system parameters and uncertainties for each system, including precise transit center times for each transit. The transit model residuals of the combined and five minute binned light curves have an rms of 183 and 255 parts per million (ppm) for WASP-12b and Qatar-1b, respectively. Most of the WASP-12b system parameter values from this work are consistent with values from previous studies, but have ∼40%–50% smaller uncertainties. Most of the Qatar-1b system parameter values and uncertainties from this work are consistent with values recently reported in the literature. We find no convincing evidence for sinusoidal TTVs with a semi-amplitude of more than ∼35 and ∼25 s in the WASP-12b and Qatar-1b systems, respectively.

On silvation and thermal transformations of B10H12(PPh3)2

International Nuclear Information System (INIS)

Il'inchik, E.A.; Dunaev, S.T.; Myakishev, K.G.; Asanov, I.P.

1994-01-01

It is shown, that exchange reaction between B 10 H 12 (SMe 2 ) 2 and triphenylphospohine is benzene leads to formation of B 10 H 12 (PPh 3 ) 2 xPh solvate during B 10 H 12 (PPh 3 ) 2 synthesis. B 10 H 12 (PPh 3 ) 2 x0.7CHCl 3 is prepared by recrystallization of the latest solvate from chloroform, B 10 H 12 (PPh 3 ) 2 - from acetone. The composition is fixed after vacuum drying (1.3 Pa; 60 deg). In all cases, prepared crystals are amorphous ones. Pyrolysis of B 10 H 12 (PPh 3 ) 2 at 250 deg is accompained by the loss of 4 hydrogen and 0.05 triphenylphosphine moles. Besides hydrogen, benzene and methane are determined in gaseous phase. Formation of boron carbide and phosphide in solid phase at 750 deg isn't observed

Vitamin B12–dependent taurine synthesis regulates growth and bone mass

Science.gov (United States)

Roman-Garcia, Pablo; Quiros-Gonzalez, Isabel; Mottram, Lynda; Lieben, Liesbet; Sharan, Kunal; Wangwiwatsin, Arporn; Tubio, Jose; Lewis, Kirsty; Wilkinson, Debbie; Santhanam, Balaji; Sarper, Nazan; Clare, Simon; Vassiliou, George S.; Velagapudi, Vidya R.; Dougan, Gordon; Yadav, Vijay K.

2014-01-01

Both maternal and offspring-derived factors contribute to lifelong growth and bone mass accrual, although the specific role of maternal deficiencies in the growth and bone mass of offspring is poorly understood. In the present study, we have shown that vitamin B12 (B12) deficiency in a murine genetic model results in severe postweaning growth retardation and osteoporosis, and the severity and time of onset of this phenotype in the offspring depends on the maternal genotype. Using integrated physiological and metabolomic analysis, we determined that B12 deficiency in the offspring decreases liver taurine production and associates with abrogation of a growth hormone/insulin-like growth factor 1 (GH/IGF1) axis. Taurine increased GH-dependent IGF1 synthesis in the liver, which subsequently enhanced osteoblast function, and in B12-deficient offspring, oral administration of taurine rescued their growth retardation and osteoporosis phenotypes. These results identify B12 as an essential vitamin that positively regulates postweaning growth and bone formation through taurine synthesis and suggests potential therapies to increase bone mass. PMID:24911144

Dual isotope Schilling test for measuring absorption of food-bound and free vitamin B12 simultaneously

International Nuclear Information System (INIS)

Doscherholmen, A.; Silvis, S.; McMahon, J.

1983-01-01

A prototype food-bound vitamin B12 (food-B12) absorption test has been developed in which 57 Co-B12 was incorporated in vitro into egg yolk (yolk-B12) and served to volunteers in 50-g cooked portions together with toast and coffee for breakfast. Six hours later, 1 mg nonlabeled B12 was given intramuscularly and 24-hour urine was collected for radioactivity measurement. In separate tests, the absorption of yolk-B12 and crystalline 57 Co-B12 was equally poor in patients with pernicious anemia. However, in patients with simple gastric achlorhydria and those who had undergone gastric surgery, the assimilation of yolk-B12 was impaired greatly, whereas the absorption of crystalline radio-B12 was normal. Egg yolk labeled with 58 Co-B12 was administered together with crystalline 57 Co-B12 in a dual isotope test with results similar to those obtained when the tests were prepared separately. This yolk- 58 Co-B12 test with its ability to detect malabsorption of food-B12 may be considered as an addition to the first part of the Schilling test

Clinical Trial Assessing the Efficacy of Gabapentin Plus B Complex (B1/B12 versus Pregabalin for Treating Painful Diabetic Neuropathy

Directory of Open Access Journals (Sweden)

Alberto Mimenza Alvarado

2016-01-01

Full Text Available Introduction. Painful diabetic neuropathy (PDN is a prevalent and impairing disorder. The objective of this study was to show the efficacy and safety of gabapentin (GBP plus complex B vitamins: thiamine (B1 and cyanocobalamine (B12 compared to pregabalin in patients with moderate to severe intensity PDN. Method. Multicenter, randomized, blind study. Two hundred and seventy patients were evaluated, 147 with GBP/B1/B12 and 123 with PGB, with a 7/10 pain intensity on the Visual Analog Scale (VAS. Five visits (12 weeks were scheduled. The GBP/B1 (100 mg/B12 (20 mg group started with 300 mg at visit 1 to 3600 mg at visit 5. The PGB group started with 75 mg/d at visit 1 to 600 mg/d at visit 5. Different safety and efficacy scales were applied, as well as adverse event assessment. Results. Both drugs showed reduction of pain intensity, without significant statistical difference (P=0.900. In the GBP/B1/B12 group, an improvement of at least 30% on VAS correlated to a 900 mg/d dose, compared with PGB 300 mg/d. Likewise, occurrence of vertigo was lower in the GBP/B1-B12 group, with a significant statistical difference, P=0.014. Conclusions. Our study shows that GPB/B1-B12 combination is as effective as PGB. Nonetheless, pain intensity reduction is achieved with 50% of the minimum required gabapentin dose alone (800 to 1600 mg/d in classic NDD trials. Less vertigo and dizziness occurrence was also observed in the GBP/B1/B12 group. This trial is registered with ClinicalTrials.gov NCT01364298.

Screening of the vitamin B12 status in an urban population sample from Romania: a pilot study

Directory of Open Access Journals (Sweden)

Crăciun Elena C.

2014-06-01

Full Text Available Scopul acestui studiu a fost evaluarea statusului vitaminei B12 într-un eşantion al populaţiei urbane adulte din România. În studiu au fost incluşi 80 de subiecţi non-vegetarieni, cu vârste cuprinse între 19 şi 74,6 ani, care nu au utilizat suplimente de vitamina B12 sau alimente fortificate cu vitamina B12. Dozarea vitaminei B12 serice s-a realizat prin metoda imunochimică cu detecţie prin chemiluminiscenţă pe analizor Elecsys 2010 (Roche. Concentraţia serică a vitaminei B12 s-a încadrat în intervalul de referinţă (191-663 pg/ml la 93,75% (95% CI 86,2-97,3% din subiecţi. La aceşti subiecţi nu s-au evidenţiat corelaţii seminificative statistic între concentraţia serică a vitaminei B12 şi vârsta subiecţilor sau concentraţia hemoglobinei. Nu s-au găsit nici diferenţe semnificative (p>0.05 ale statusului vitaminic la femei faţă de bărbaţi. Concentraţia serică a vitaminei B12 s-a situat sub limita inferioară a intervalului de referinţă la 5% (95%CI 1,96-12,16% din subiecţii investigaţi, fiind asociată tratamentului cu contraceptive orale, inhibitori ai pompei de protoni (IPP respectiv sindromului de colon iritabil. La un număr mare de subiecţi cu vârsta sub 50 de ani, concentraţia serică a vitaminei B12 s-a încadrat în limitele corespunzătoare statusului marginal. Rezultatele studiului sugerează necesitatea efectuării screeningului statusului vitaminei B12 la întreaga populaţie, importanţa identificării factorilor responsabili de prevalenţa crescută a statusului marginal şi importanţa monitorizării statusului vitaminei B12 la subiecţii care fac tratament îndelungat cu unele medicamente.

Hyperfine interactions of /sup 12/B implanted in ferromagnetic nickel

Energy Technology Data Exchange (ETDEWEB)

Hamagaki, H; Nojiri, Y; Sugimoto, K [Osaka Univ., Toyonaka (Japan). Dept. of Physics; Nakai, K

1979-12-01

Temperature dependences of hyperfine interactions of /sup 12/B implanted in Ni were investigated in the temperature range of 6 K - 730 K by the NMR method with use of polarized /sup 12/B produced in a nuclear reaction and the asymmetric ..beta.. decay. Two kinds of hyperfine fields with different signs were observed (B sub(hf)sup(+) = +4.161 +- 0.022 kG and B sub(hf)sup(-) = -1.611 +- 0.021 kG at 6 K), which indicated that the implanted /sup 12/B were trapped in two different sites (S/sup +/ and S/sup -/, respectively). The spin-lattice relaxation times T/sub 1/ and the population rates at the two sites were studied. Near the Curie temperature, an effect of critical slowing-down of the spin-spin correlation was observed as steep variation of T/sub 1/. The behavior of local field around T sub(C) was also studied by varying the external field. Results of these experiments near T sub(C) indicate itinerant nature of the electron-spin structure in nickel.

Determination of vitamin B12 (cobalamine) absorption by means of a simple double-isotope technique

International Nuclear Information System (INIS)

Hippe, E.; Brynskov, J.; Gimsing, P.; Hjelt, K.

1986-01-01

The background, practical instruction and clinical results of a simplified method of determining the absorption of cobalamine (vitamin B 12 ) are presented. The simultaneous administration of 57 CO-CN-cobalamine, a non-absorbable marker ( 51 CrCl 3 ), and red carmine tablets enable quantitative assessments of the cobalamine absorption by collection of a small red feaces sample. In contrast to the classical Schilling-test, this vitamin B 12 absorption test (B 12 -ABS-test) or faeces-spot-test is, independent of fasting, flushing dose, renal function and diurnal urinary collection. This is documented in a series of clinical studies. The B 12 -ABS-test provides accurate and precise results compared to the reference method (whole-body-counting). The Schilling test, on the contrary, gives approximately 50% false low values in a reference group of elderly hospitalized patients. A modification of the B 12 -ABS-test, has been used to determine the cobalamine absorption in children, and a set of age-related reference intervals have been established, together with quantitative measurements of the cobalamine absorption in children with small bowel diseases. Based on several years of practical experience, we recommend replacement of the Schilling test by this simple double-isotope technique. (author)

Imerslund-Grasbeck syndrome in a Chinese family with distinct skin lesions refractory to vitamin B12.

OpenAIRE

Lin, S H; Sourial, N A; Lu, K C; Hsueh, E J

1994-01-01

Two brothers in a Chinese family with selective malabsorption of vitamin B12 associated with proteinuria (Imerslund-Grasbeck syndrome) presented with widespread mottled skin pigmentation, termed poikiloderma. In contrast to anaemia, this pigmentary disturbance remained unresponsive to vitamin B12 replacement. This is different from the reported hyperpigmentation sometimes seen in vitamin B12 deficiency which is reversible following treatment. As far as is known, an irreversible and persistent...

Vitamin B12 among Vegetarians: Status, Assessment and Supplementation

Directory of Open Access Journals (Sweden)

Gianluca Rizzo

2016-11-01

Full Text Available Cobalamin is an essential molecule for humans. It acts as a cofactor in one-carbon transfers through methylation and molecular rearrangement. These functions take place in fatty acid, amino acid and nucleic acid metabolic pathways. The deficiency of vitamin B12 is clinically manifested in the blood and nervous system where the cobalamin plays a key role in cell replication and in fatty acid metabolism. Hypovitaminosis arises from inadequate absorption, from genetic defects that alter transport through the body, or from inadequate intake as a result of diet. With the growing adoption of vegetarian eating styles in Western countries, there is growing focus on whether diets that exclude animal foods are adequate. Since food availability in these countries is not a problem, and therefore plant foods are sufficiently adequate, the most delicate issue remains the contribution of cobalamin, which is poorly represented in plants. In this review, we will discuss the status of vitamin B12 among vegetarians, the diagnostic markers for the detection of cobalamin deficiency and appropriate sources for sufficient intake, through the description of the features and functions of vitamin B12 and its absorption mechanism.

Vitamin B12 among Vegetarians: Status, Assessment and Supplementation.

Science.gov (United States)

Rizzo, Gianluca; Laganà, Antonio Simone; Rapisarda, Agnese Maria Chiara; La Ferrera, Gioacchina Maria Grazia; Buscema, Massimo; Rossetti, Paola; Nigro, Angela; Muscia, Vincenzo; Valenti, Gaetano; Sapia, Fabrizio; Sarpietro, Giuseppe; Zigarelli, Micol; Vitale, Salvatore Giovanni

2016-11-29

Cobalamin is an essential molecule for humans. It acts as a cofactor in one-carbon transfers through methylation and molecular rearrangement. These functions take place in fatty acid, amino acid and nucleic acid metabolic pathways. The deficiency of vitamin B12 is clinically manifested in the blood and nervous system where the cobalamin plays a key role in cell replication and in fatty acid metabolism. Hypovitaminosis arises from inadequate absorption, from genetic defects that alter transport through the body, or from inadequate intake as a result of diet. With the growing adoption of vegetarian eating styles in Western countries, there is growing focus on whether diets that exclude animal foods are adequate. Since food availability in these countries is not a problem, and therefore plant foods are sufficiently adequate, the most delicate issue remains the contribution of cobalamin, which is poorly represented in plants. In this review, we will discuss the status of vitamin B12 among vegetarians, the diagnostic markers for the detection of cobalamin deficiency and appropriate sources for sufficient intake, through the description of the features and functions of vitamin B12 and its absorption mechanism.

Structure of 12B from measurement and R-matrix analysis of sigma(theta) for 11B(n,n)11B and 11B(n,n')11Bsup(*)(2.12 MeV), and shell-model calculations

International Nuclear Information System (INIS)

Koehler, P.E.; Knox, H.D.; Resler, D.A.; Lane, R.O.

1983-01-01

Differential cross sections for neutrons, elastically scattered from 11 B and inelastically scattered to the first excited state 11 B*(2.12 MeV) have been measured at 13 incident energies for 4.8 12 B of 7.8 to 10.3 MeV. The cross sections were measured at nine laboratory angles per energy from 20 0 to 160 0 and show considerable resonance structure. Differential inelastic cross sections were also measured for the 4.45 and 5.02 MeV levels of 11 B for 2 to 9 angles at several incident energies. These new elastic and inelastic 2.12 MeV level data have been analyzed together with previously publsihed cross sections for 2 12 B. The shell model was used to calculate states in 12 B as well as spectroscopic amplitudes for reactions leading to these states. The results of this model calculation are compared to those of the R-matrix analysis. Much of the structure observed in the experimental work is predicted by the model for Esub(x) < or approx. 7 MeV. For levels of higher excitation the agreement is not as good. The experimental data are also compared to continuum shell-model calculations. (orig.)

12 CFR Appendix B to Part 345 - CRA Notice

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2010-01-01

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Magnetic substate populations of product nuclei in the /sup 11/B(d,p)/sup 12/B reaction

Energy Technology Data Exchange (ETDEWEB)

Tanaka, M; Ochi, S; Minamisono, T; Mizobuchi, A; Sugimoto, K [Osaka Univ., Toyonaka (Japan). Lab. of Nuclear Studies

1976-05-31

Magnetic substate populations of product nuclei in the /sup 11/B(d,p)/sup 12/B reaction have been measured in an energy range Esub(d) = 1.3-3.0 MeV at recoil angles of thetasub(R) = 55/sup 0/, 45/sup 0/ and 27/sup 0/-37/sup 0/. A static magnetic field (3 kG) was applied normal to the reaction plane to keep the nuclear orientation. Quadrupole effects on the implanted /sup 12/B in Ta were utilized to perturb the Zeeman splitting. NMR transitions were induced, and detected by the asymmetry change in the ..beta..-decay of /sup 12/B. From this information, the magnetic substate populations were determined, for the unique assignment of which the sign of the quadrupole interaction had to be known. For this purpose, a p-..gamma.. angular correlation was measured, which determined the alignment of the first excited state of /sup 12/B. A comparison of the present result with theoretical predictions is given, together with the resultant information about j-mixings in the /sup 12/B states.

[Neurological signs due to isolated vitamin B12 deficiency].

Science.gov (United States)

Martinez Estrada, K M; Cadabal Rodriguez, T; Miguens Blanco, I; García Méndez, L

2013-01-01

Isolated vitamin B12 deficiency is a common condition in elderly patients but uncommon in patients younger than 30 years, with an average age of onset between 60 and 70 years. This is because the dietary cobalamin, which is normally split by enzymes in meat in the presence of hydrochloric acid and pepsin in the stomach, is not released in the stomachs of elderly patients, usually due to achlorhydria. Although the body may be unable to release cobalamin it does retain the ability to absorb vitamin B12 in its crystalline form, which is present in multivitamin preparations. Other causes are due to drugs that suppress gastric acid production. Neurological signs of vitamin B12 deficiency can occur in patients with a normal haematocrit and red cell indices. They include paresthesia, loss of sensation and strength in the limbs, and ataxia. Reflexes may be slowed down or increased. Romberg and Babinsky signs may be positive, and vibration and position sensitivity often decreases. Behavoural disorders range from irritability and memory loss to severe dementia. The symptoms often do not fully respond to treatment. A case is presented of an isolated vitamin B12 deficiency in 27 year-old female patient who was seen in primary health care. During anamnesis she mentioned low back pain, to which she attributed the loss of strength and tenderness in the right side of the body, as well as the slow and progressive onset of accompanied headache for the previous 4 days. Copyright © 2012 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España. All rights reserved.

Determination of four forms of vitamin B12 and other B vitamins in seawater by liquid chromatography/tandem mass spectrometry.

Science.gov (United States)

Heal, Katherine R; Carlson, Laura Truxal; Devol, Allan H; Armbrust, E Virginia; Moffett, James W; Stahl, David A; Ingalls, Anitra E

2014-11-30

Vitamin B(12) is an essential nutrient for more than half of surveyed marine algae species, but methods for directly measuring this important cofactor in seawater are limited. Current mass spectrometry methods do not quantify all forms of B(12), potentially missing a significant portion of the B(12) pool. We present a method to measure vitamins B(1), B(2), B(6), B(7) and four forms of B(12) dissolved in seawater. The method entails solid-phase extraction, separation by ultra-performance liquid chromatography, and detection by triple-quadrupole tandem mass spectrometry using stable-isotope-labeled internal standards. We demonstrated the use of this method in the environment by analyzing B(12) concentrations at different depths in the Hood Canal, part of the Puget Sound estuarine system in Washington State. Recovery of vitamin B(12) forms during the preconcentration steps was >71% and the limits of detection were B(12) in seawater at our field site. We developed a method for quantifying four forms of B(12) in seawater by liquid chromatography/mass spectrometry with the option of simultaneous analysis of vitamins B(1), B(2), B(6), and B(7). We validated the method and demonstrated its application in the field. Copyright © 2014 John Wiley & Sons, Ltd.

The human serum metabolome of vitamin B-12 deficiency and repletion, and associations with neurological function

Science.gov (United States)

We characterize the human serum metabolome in sub-clinical vitamin B-12 (B-12) deficiency and repletion. A pre-post treatment study provided one injection of 10 mg B-12 to 27 community-dwelling elderly Chileans with B-12 deficiency evaluated with serum B-12, plasma homocysteine, methylmalonic acid a...

Polarization of /sup 12/B in deep-inelastic heavy-ion reaction /sup 100/Mo(/sup 14/N,/sup 12/B). [Q value, 200 MeV

Energy Technology Data Exchange (ETDEWEB)

Takahashi, N; Miake, Y; Nojiri, Y; Minamisono, T; Mizobuchi, A; Sugimoto, K [Osaka Univ., Toyonaka (Japan). Lab. of Nuclear Studies; Ishihara, M [Institute of Physical and Chemical Research, Wako, Saitama (Japan)

1978-10-09

Spin polarization of /sup 12/B was measured for /sup 100/Mo(/sup 14/N,/sup 12/B) at Esub(i)(/sup 14/N) approximately 200 MeV as a function of Q value down to Q approximately - 150 MeV, and was found anti-parallel to ksub(f)xksub(i) in the deep-inelastic region. The data together with those at lower incident energies show a systematic trend in Q-value dependence of the polarization.

Measurements of vitamin B12 in human blood serum using resonance Raman spectroscopy

Science.gov (United States)

Tsiminis, G.; Schartner, E. P.; Brooks, J. L.; Hutchinson, M. R.

2016-12-01

Vitamin B12 (cobalamin and its derivatives) deficiency has been identified as a potential modifiable risk factor for dementia and Alzheimer's disease. Chronic deficiency of vitamin B12 has been significantly associated with an increased risk of cognitive decline. An effective and efficient method for measuring vitamin B12 concentration in human blood would enable ongoing tracking and assessment of this potential modifiable risk factor. In this work we present an optical sensor based on resonance Raman spectroscopy for rapid measurements of vitamin B12 in human blood serum. The measurement takes less than a minute and requires minimum preparation (centrifuging) of the collected blood samples.

Metamagnetic behaviour of La1-xGdxFe12B6 compounds

International Nuclear Information System (INIS)

Li, Q.A.; Groot, C.H. de; Boer, F.R. de; Buschow, K.H.J.

1997-01-01

The magnetic properties of compounds of the type La 1-x Gd x Fe 12 B 6 have been studied in high magnetic fields at 4.2 K. LaFe 12 B 6 is a compound with Fe moments close to magnetic instability and values not larger than about 0.5 μ B . Substitution of Gd for part of the La and application of high magnetic fields enhance the Fe moments to values in excess of 2 μ B . The high-moment state in LaFe 12 B 6 is reached via a metamagnetic transition. This first-order transition is associated with an extremely large hysteresis of nearly 7 T at 4.2 K. (orig.)

Loss of vitamin B(12) in fish (round herring) meats during various cooking treatments.

Science.gov (United States)

Nishioka, Michiko; Kanosue, Fuki; Yabuta, Yukinori; Watanabe, Fumio

2011-01-01

The loss of vitamin B(12) in round herring meats during various cooking treatments was evaluated. Although amounts of vitamin B(12) were three times greater in the viscera (37.5 ± 10.6 µg/100 g fresh weight) than in the meats, about 73% of total vitamin B(12) found in the whole fish body (except for head and bones) were recovered in the meats (5.1 ± 1.0 µg of vitamin B(12)). The vitamin B(12) contents of the round herring's meats were significantly decreased up to ~62% during cooking by grilling, boiling, frying, steaming, and microwaving. There was, however, no loss of vitamin B(12) during vacuum-packed pouch cooking. Model experiment using hydroxocobalamin suggest that loss of vitamin B(12) is dependent on the degree of temperature and time used in conventional cooking, and is further affected by the concomitant ingredients of food. Retention of vitamin B(12) was not dependent on vacuum or temperature (or both) used in the vacuum-packed pouch cooking.

Vitamin B-12 concentrations in breast milk are low and are not associated with reported household hunger, recent animal source food or vitamin B-12 intake among women in rural Kenya

Science.gov (United States)

Background: Breastmilk vitamin B-12 concentration may be inadequate in mothers living in regions where animal source food consumption is low or infrequent. Vitamin B-12 deficiency causes megaloglastic anemia and impairs growth and development in children. Objective: To measure vitamin B-12 in breast...

Syntheses, crystal structures, and properties of the isotypic pair [Cr(H{sub 2}O){sub 6}]{sub 2}[B{sub 12}H{sub 12}]{sub 3}.15H{sub 2}O and [In(H{sub 2}O){sub 6}]{sub 2}[B{sub 12}H{sub 12}]{sub 3}.15H{sub 2}O

Energy Technology Data Exchange (ETDEWEB)

Van, Nguyen-Duc; Kleeberg, Fabian M.; Schleid, Thomas [Institut fuer Anorganische Chemie, Universitaet Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart (Germany)

2015-11-15

Single crystals of [Cr(H{sub 2}O){sub 6}]{sub 2}[B{sub 12}H{sub 12}]{sub 3}.15H{sub 2}O and [In(H{sub 2}O){sub 6}]{sub 2}[B{sub 12}H{sub 12}]{sub 3}.15H{sub 2}O were obtained by reactions of aqueous solutions of the acid (H{sub 3}O){sub 2}[B{sub 12}H{sub 12}] with chromium(III) hydroxide and indium metal shot, respectively. The title compounds crystallize isotypically in the trigonal system with space group R anti 3c (a = 1157.62(3), c = 6730.48(9) pm for the chromium, a = 1171.71(3), c = 6740.04(9) pm for the indium compound, Z = 6). The arrangement of the quasi-icosahedral [B{sub 12}H{sub 12}]{sup 2-} dianions can be considered as stacking of two times nine layers with the sequence..ABCCABBCA.. and the metal trications arrange in a cubic closest packed..abc.. stacking sequence. The metal trications are octahedrally coordinated by six water molecules of hydration, while another fifteen H{sub 2}O molecules fill up the structures as zeolitic crystal water or second-sphere hydrating species. Between these free and the metal-bonded water molecules, bridging hydrogen bonds are found. Furthermore, there is also evidence of hydrogen bonding between the anionic [B{sub 12}H{sub 12}]{sup 2-} clusters and the free zeolitic water molecules according to B-H{sup δ-}..{sup δ+}H-O interactions. Vibrational spectroscopy studies prove the presence of these hydrogen bonds and also show slight distortions of the dodecahydro-closo-dodecaborate anions from their ideal icosahedral symmetry (I{sub h}). Thermal decomposition studies for the example of [Cr(H{sub 2}O){sub 6}]{sub 2}[B{sub 12}H{sub 12}]{sub 3}.15H{sub 2}O gave no hints for just a simple multi-stepwise dehydration process. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Measurement of the $^{12}$C($n,p$)$^{12}$B cross section at n_TOF (CERN) by in-beam activation analysis

CERN Document Server

Žugec, P.; Bosnar, D.; Mengoni, A.; Altstadt, S.; Andrzejewski, J.; Audouin, L.; Barbagallo, M.; Bécares, V.; Bečvář, F.; Belloni, F.; Berthoumieux, E.; Billowes, J.; Boccone, V.; Brugger, M.; Calviani, M.; Calviño, F.; Cano-Ott, D.; Carrapiço, C.; Cerutti, F.; Chiaveri, E.; Chin, M.; Cortés, G.; Cortés-Giraldo, M.A.; Cosentino, L.; Diakaki, M.; Domingo-Pardo, C.; Dressler, R.; Duran, I.; Eleftheriadis, C.; Ferrari, A.; Finocchiaro, P.; Fraval, K.; Ganesan, S.; García, A.R.; Giubrone, G.; Gómez-Hornillos, M.B.; Gonçalves, I.F.; González-Romero, E.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Gurusamy, P.; Heinitz, S.; Jenkins, D.G.; Jericha, E.; Käppeler, F.; Karadimos, D.; Kivel, N.; Kokkoris, M.; Krtička, M.; Kroll, J.; Langer, C.; Lederer, C.; Leeb, H.; Leong, L.S.; Lo Meo, S.; Losito, R.; Manousos, A.; Marganiec, J.; Martínez, T.; Massimi, C.; Mastinu, P.; Mastromarco, M.; Mendoza, E.; Milazzo, P.M.; Mingrone, F.; Mirea, M.; Mondalaers, W.; Musumarra, A.; Paradela, C.; Pavlik, A.; Perkowski, J.; Plompen, A.; Praena, J.; Quesada, J.; Rauscher, T.; Reifarth, R.; Riego, A.; Roman, F.; Rubbia, C.; Sarmento, R.; Saxena, A.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Tagliente, G.; Tain, J.L.; Tarrío, D.; Tassan-Got, L.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Versaci, R.; Vermeulen, M.J.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Ware, T.; Weigand, M.; Weiß, C.; Wright, T.

2014-01-01

The integral cross section of the $^{12}$C($n,p$)$^{12}$B reaction has been determined for the first time in the neutron energy range from threshold to several GeV at the n_TOF facility at CERN. The measurement relies on the activation technique, with the $\\beta$-decay of $^{12}$B measured over a period of four half-lives within the same neutron bunch in which the reaction occurs. The results indicate that model predictions, used in a variety of applications, are mostly inadequate. The value of the integral cross section reported here can be used as a benchmark for verifying or tuning model calculations.

Vitamin B12 deficiency presenting as acute ataxia.

Science.gov (United States)

Crawford, John Ross; Say, Daphne

2013-03-26

A previously healthy 7-year-old Caucasian boy was hospitalised for evaluation of acute ataxia and failure to thrive, initially suspicious for an intracranial mass. Weight and body mass index were below the third percentile and he demonstrated loss of joint position and vibratory sense on examination. Laboratory studies revealed megaloblastic anaemia while an initial MRI of the brain showed no evidence of mass lesions or other abnormalities. A dietary history revealed the child subscribed to a restrictive vegan diet with little to no intake of animal products or other fortified foods. The child was diagnosed with presumed vitamin B12 deficiency and was treated with intramuscular B12 injections. Neurological symptoms resolved promptly within several days after starting therapy. This case underlines the importance of assessing nutritional status in the evaluation of neurological dysfunction in the pediatric patient.

Sensory Neuronopathy Revealing Severe Vitamin B12 Deficiency in a Patient with Anorexia Nervosa: An Often-Forgotten Reversible Cause

Directory of Open Access Journals (Sweden)

Jérôme Franques

2017-03-01

Full Text Available Vitamin B12 (B12 deficiency is known to be associated with various neurological manifestations. Although central manifestations such as dementia or subacute combined degeneration are the most classic, neurological manifestations also include sensory neuropathies. However, B12 deficiency is still rarely integrated as a potential cause of sensory neuronopathy. Moreover, as many medical conditions can falsely normalize serum B12 levels even in the context of a real B12 deficiency, some cases may easily remain underdiagnosed. We report the illustrating case of an anorexic patient with sensory neuronopathy and consistently normal serum B12 levels. After all classical causes of sensory neuronopathy were ruled out, her clinical and electrophysiological conditions first worsened after folate administration, but finally improved dramatically after B12 administration. B12 deficiency should be systematically part of the etiologic workup of sensory neuronopathy, especially in a high risk context such as anorexia nervosa.

Homocisteína, folato e vitamina B12 em pacientes colombianos portadores de coronariopatia Homocysteine, folate and vitamin B12 in colombian patients with coronary disease

Directory of Open Access Journals (Sweden)

Gilberto Garcia

2007-08-01

Full Text Available OBJETIVO: Determinar a existência de associação entre os níveis plasmáticos de homocisteína, folato ou vitamina B12 e síndrome coronariana aguda em pacientes colombianos. MÉTODOS: Estudo caso-controle: foram 50 pacientes portadores de síndrome coronariana aguda e 50 pacientes ambulatoriais sem síndrome coronariana. Foram medidos os níveis de homocisteína, folato e vitamina B12 por meio de imunoensaio por quimioluminescência. Foram também medidos os níveis de colesterol e frações, triglicérides, uréia, creatinina, hemoglobina e hematócrito. RESULTADOS: As concentrações plasmáticas médias de homocisteína foram significativamente diferentes entre os casos (12,4 µmol/l ± 6,0 e os controles (9,7 µmol/l ± 2,4, p=0,01. Os níveis de ácido fólico dos casos foram menores que os dos controles (respectivamente 10,5 ng/ml ± 3,5 x 12,6 ng/ml ± 3,6; p=0,01. Foi observada relação inversa entre os níveis de folato e os de homocisteína. Não houve relação entre os níveis de vitamina B12 e os de homocisteína. Houve diferença significativa nos níveis de triglicérides entre os grupos caso e controle (respectivamente 136,91 ± 67,27 x 174,3 ± 77,6; p=0,01. A razão das chances para hiper-homocisteinemia na síndrome coronariana aguda foi de 4,45 (intervalo de confiança de 95%: 1,5 - 13,3. CONCLUSÃO: O presente estudo demonstrou associação significativa entre os níveis de homocisteína e síndrome coronariana aguda em pacientes colombianos semelhante à encontrada em populações européias e norte-americanas. Houve correlação negativa entre os níveis plasmáticos de homocisteína e os de folato. Não houve associação entre os níveis plasmáticos de homocisteína e os de vitamina B12.OBJECTIVE: To determine the occurrence of association between homocysteine, folate, or vitamin B12 plasma levels and acute coronary syndrome in Colombian patients. METHODS: Case control study: cases were 50 patients with acute

4-ethylphenyl-cobalamin impairs tissue uptake of vitamin B12 and causes vitamin B12 deficiency in mice

DEFF Research Database (Denmark)

Mutti, Elena; Ruetz, Markus; Birn, Henrik

2013-01-01

Coβ-4-ethylphenyl-cob(III) alamin (EtPhCbl) is an organometallic analogue of vitamin B12 (CNCbl) which binds to transcobalamin (TC), a plasma protein that facilitates the cellular uptake of cobalamin (Cbl). In vitro assays with key enzymes do not convert EtPhCbl to the active coenzyme forms of Cbl...... treated with EtPhCbl (1.01±0.12 µmol/L) compared to controls (0.30±0.02 µmol/L) and CNCbl (0.29±0.01 µmol/L) treated animals. The same pattern was observed for tHcy. Plasma total Cbl concentration was higher in animals treated with EtPhCbl (128.82±1.87 nmol/L) than in CNCbl treated animals (87.......64±0.93 nmol/L). However, the organ levels of total Cbl were significantly lower in animals treated with EtPhCbl compared to CNCbl treated animals or controls, notably in the liver (157.07±8.56 pmol/g vs. 603.85±20.02 pmol/g, and 443.09±12.32 pmol/g, respectively). Differences between the three groups...

The Relationship of Vitamin B12 Deficiency and Red Cell Distribution Width-Platelet Ratio

Directory of Open Access Journals (Sweden)

Nigar Yilmaz

2016-09-01

Full Text Available Objective: We aimed to investigate the relationship between vitamin B12 deficiency and red cell distribution widthplatelet ratio (RPR, and the variations in the parameters on vitamin B12 treatment. Methods: One hundred fifty-four patients with untreated vitamin B12 deficiency (56% men, mean age: 50 ± 12.7 years (untreated group, 86 patients with vitamin B12 deficiency (62% men, mean age: 42 ± 20.7 years on vitamin B12 treatment (treated group, and 92 age- and sex-matched control group (54% men, mean age: 45 ± 15.1 years were included in the study. Hematological parameters were evaluated by the method of laser-based flow cytometric impedance, using an automated blood cell counter (ABX Pentra 120 Hematology Blood Analyzer. Results: RPR was significantly reduced in treated group compared with untreated group (4.88 ± 1.06; 6.13 ± 1.27; p0.05. Conclusion: We proposed that vitamin B12 deficiency has effects on RPR and supplementation with vitamin B12 corrects the RPR levels. J Clin Exp Invest 2016; 7 (3: 211-215

Status of Vitamin B12 and Folate among the Urban Adult Population in South India.

Science.gov (United States)

Sivaprasad, M; Shalini, T; Balakrishna, N; Sudarshan, M; Lopamudra, P; Suryanarayana, P; Arlappa, N; Ravikumar, B P; Radhika, M S; Reddy, G Bhanuprakash

2016-01-01

Deficiency of vitamin B12 (B12) and folate (FA) leads to a wide spectrum of disorders that affect all age groups. However, reports on B12 and FA status in healthy adults in India are limited. Hence, we determined the plasma levels and dietary intake of B12 and FA in the adult population. We conducted a community-based cross-sectional study in an urban setup among 630 apparently healthy adults distributed into 3 age groups: 21-40, 41-60 and >60 years. Plasma concentrations of B12 and FA were analyzed by radio immunoassay and dietary intake by 24-hour recall method. The overall prevalence of FA deficiency was 12%, but there was no significant difference in plasma FA concentrations among the groups. While the overall prevalence of B12 deficiency was 35%, it was significantly higher in the 21-40 (44%) and 41-60 age groups (40%) when compared with the >60 group (30%). B12 deficiency was higher in vegetarians (54%) compared to those consuming mixed diet (31%), and the reverse was the case with FA. However, the dietary intakes of FA and B12 were not significantly different among the groups. These results indicate a higher prevalence of B12 deficiency in apparently healthy adults in an urban setup. © 2015 S. Karger AG, Basel.

Comparison of virulence of Francisella tularensis ssp. holarctica genotypes B.12 and B.FTNF002-00.

Science.gov (United States)

Kreizinger, Zsuzsa; Erdélyi, Károly; Felde, Orsolya; Fabbi, Massimo; Sulyok, Kinga M; Magyar, Tibor; Gyuranecz, Miklós

2017-02-10

Two main genetic groups (B.12 and B.FTNF002-00) of Francisella tularensis ssp. holarctica are endemic in Europe. The B.FTNF002-00 group proved to be dominant in Western European countries, while strains of the B.12 group were isolated mainly in Northern, Central and Eastern Europe. The clinical course of tularemia in the European brown hare (Lepus europaeus) also shows distinct patterns according to the geographical area. Acute course of the disease is observed in hares in Western European countries, while signs of sub-acute or chronic infection are more frequently detected in the eastern part of the continent. The aim of the present study was to examine whether there is any difference in the virulence of the strains belonging to the B.FTNF002-00 and B.12 genetic clades. Experimental infection of Fischer 344 rats was performed by intra-peritoneal injection of three dilutions of a Hungarian (B.12 genotype) and an Italian (B.FTNF002-00 genotype) F. tularensis ssp. holarctica strain. Moderate difference was observed in the virulence of the two genotypes. Significant differences were observed in total weight loss values and scores of clinical signs between the two genotypes with more rats succumbing to tularemia in groups infected with the B.FTNF002-00 genotype. Results of the experimental infection are consistent with previous clinical observations and pathological studies suggesting that F. tularensis ssp. holarctica genotype B.FTNF002-00 has higher pathogenic potential than the B.12 genotype.

Evaluation of vitamin B 12 deficiency in various clinical condition

International Nuclear Information System (INIS)

Baig, J.A.; Alam, J.M.; Kazmi, T.; Waseem, S.; Hussain, A.; Arif, S.; Shaheen, R.; Sultana, I.

2010-01-01

Low levels of vitamin B 12 have been associated with several clinical conditions. However no single symptom or group of symptoms can be made responsible. Reported causes of deficiency among older population are hematologic or neurological, followed by gastrointestinal and possibly vascular symptoms. The present prospective observational study was, hence, initiated to evaluate the underlying clinical condition or symptoms associated with vitamin B12 deficiency. The study was prospective observational and carried out on 121 patients (males, n=63 and females, n=58) for the period from January 1, 2004 to January 24, 2007. Age ranges were between 16 - 70 years, and categorized as > 60 yrs and < 60 years. All blood parameters were analyzed by standardized methods on automated analyzers. The deficiency was found to be more prevalent in males and increased from 52.06% to 58.10% in individuals with vitamin B12 <150 pg/ml. Mal nourishment was noted among the most subjects and weakness and anemia were frequent clinical findings (35.55%, n=43, 14%, n=51). Other clinical conditions were neuropsychiatric. Whereas less frequent findings were paraesthesia and gastrointestinal symptoms. Hypertension was more prevalent in vitamin B12 deficient individuals followed by diabetes, dementia, stroke, ischemic heart disease and Parkinson's disease. (author)

The tinker, tailor, soldier in intracellular B12 trafficking.

Science.gov (United States)

Banerjee, Ruma; Gherasim, Carmen; Padovani, Dominique

2009-10-01

The recognition of eight discrete genetic complementation groups among patients with inherited cobalamin disorders provided early insights into the complexity of a cofactor-processing pathway that supports only two known B(12)-dependent enzymes in mammals. With the identification of all eight genes now completed, biochemical interrogations of their functions have started and are providing novel insights into a trafficking pathway involving porters that tinker with and tailor the active cofactor forms and editors that ensure the fidelity of the cofactor loading process. The principles of sequestration and escorted delivery of a rare and reactive organometallic cofactor that are emerging from studies on B(12) might be of general relevance to other cofactor trafficking pathways.

Demencia por déficit de vitamina B12: reporte de caso

OpenAIRE

Junco Bonet, Miguel Damián

2014-01-01

Fundamento: la deficiencia de vitamina B12 (cianocobalamina) puede producir varios desórdenes neurológicos, incluida la neuropatía periférica, degeneración subaguda combinada de la médula espinal, neuropatía óptica y alteraciones cognitivas que van desde la confusión leve hasta la demencia o la psicosis. La causa más frecuente de deficiencia de vitamina B12 es la anemia perniciosa. Objetivo: presentar un caso clínico de demencia por déficit de vitamina B12. Caso clínico: paciente masculino de...

Vitamin B12 Phosphate Conjugation and Its Effect on Binding to the Human B12 -Binding Proteins Intrinsic Factor and Haptocorrin

DEFF Research Database (Denmark)

Ó Proinsias, Keith; Ociepa, Michał; Pluta, Katarzyna

2016-01-01

The binding of vitamin B12 derivatives to human B12 transporter proteins is strongly influenced by the type and site of modification of the cobalamin original structure. We have prepared the first cobalamin derivative modified at the phosphate moiety. The reaction conditions were fully optimized...... and its limitations examined. The resulting derivatives, particularly those bearing terminal alkyne and azide groups, were isolated and used in copper-catalyzed alkyne-azide cycloaddition reactions (CuAAC). Their sensitivity towards light revealed their potential as photocleavable molecules. The binding...... abilities of selected derivatives were examined and compared with cyanocobalamin. The interaction of the alkylated derivatives with haptocorrin was less affected than the interaction with intrinsic factor. Furthermore, the configuration of the phosphate moiety was irrelevant to the binding process....

The impact of vegan diet on B-12 status in healthy omnivores: five-year prospective study.

Science.gov (United States)

Mądry, Edyta; Lisowska, Aleksandra; Grebowiec, Philip; Walkowiak, Jarosław

2012-04-02

There are no long-term prospective studies assessing the impact of the vegan diet on vitamin B-12 (B-12) status. Many vegans take B-12 supplements irregularly or refuse to adopt them at all, considering them to be "unnatural" products. The use of B-12 fortified food may be an alternative. Therefore, we aimed to estimate the long-term effect of a vegan diet on serum B-12 concentrations in healthy omnivore adults, comparing the influence of natural products consumption and B-12 fortified food. A five year prospective study was carried out comprising 20 omnivore healthy adult subjects, who moved to strict vegan diet for 5 years. Ten volunteers followed vegan diet based entirely on natural products, while the remaining ten subjects consumed food fortified in B-12. In all subjects serum vitamin B-12 concentration was determined before and 6, 12, 24 and 60 months after the implementation of the diet. A significant decrease (p vegan diet. However, observed changes were in fact limited to the subgroup consuming exclusively natural products (p vegan diet is associated with the risk of vitamin B-12 deficiency. B-12 fortified products might constitute a valuable alternative in vegans refusing to take vitamin supplements.

Treatment of depression: time to consider folic acid and vitamin B12.

Science.gov (United States)

Coppen, Alec; Bolander-Gouaille, Christina

2005-01-01

We review the findings in major depression of a low plasma and particularly red cell folate, but also of low vitamin B12 status. Both low folate and low vitamin B12 status have been found in studies of depressive patients, and an association between depression and low levels of the two vitamins is found in studies of the general population. Low plasma or serum folate has also been found in patients with recurrent mood disorders treated by lithium. A link between depression and low folate has similarly been found in patients with alcoholism. It is interesting to note that Hong Kong and Taiwan populations with traditional Chinese diets (rich in folate), including patients with major depression, have high serum folate concentrations. However, these countries have very low life time rates of major depression. Low folate levels are furthermore linked to a poor response to antidepressants, and treatment with folic acid is shown to improve response to antidepressants. A recent study also suggests that high vitamin B12 status may be associated with better treatment outcome. Folate and vitamin B12 are major determinants of one-carbon metabolism, in which S-adenosylmethionine (SAM) is formed. SAM donates methyl groups that are crucial for neurological function. Increased plasma homocysteine is a functional marker of both folate and vitamin B12 deficiency. Increased homocysteine levels are found in depressive patients. In a large population study from Norway increased plasma homocysteine was associated with increased risk of depression but not anxiety. There is now substantial evidence of a common decrease in serum/red blood cell folate, serum vitamin B12 and an increase in plasma homocysteine in depression. Furthermore, the MTHFR C677T polymorphism that impairs the homocysteine metabolism is shown to be overrepresented among depressive patients, which strengthens the association. On the basis of current data, we suggest that oral doses of both folic acid (800 microg daily

Spin control of 12B and 12N and the axial charge from their β-ray spin-alignment correlations

International Nuclear Information System (INIS)

Yamaguchi, T.; Minamisono, K.; Ikeda, T.; Muramoto, Y.; Fukuda, M.; Matsuta, K.; Nojiri, Y.; Minamisono, T.

1999-01-01

The spin manipulation technique by use of the β-NMR is further refined, based on the recent thorough studies of hyperfine interactions of 12 B and 12 N in Mg. By using this technique, the alignment correlation terms in the β-ray angular distribution of the A = 12 system are precisely measured, so that the axial charge is singled out to be y = 4.66 ± 0.06 (stat.) ± 0.13 (syst.) which shows clear mesonic enhancement over the impulse value

Mathematical modeling of glutathione status in type 2 diabetics with vitamin B12 deficiency

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Varun eKaramshetty

2016-03-01

Full Text Available Deficiencies in vitamin B12 and glutathione (GSH are associated with anumber of diseases including type 2 diabetes mellitus. We tested newly diag-nosed Indian diabetic patients for correlation between their vitamin B12 andGSH, and found it to be weak. Here we seek to examine the theoreticaldependence of GSH on vitamin B12 with a mathematical model of 1-carbonmetabolism due to Reed and co-workers. We study the methionine cycleof the Reed-Nijhout model by developing a simple ‘stylized model’ that cap-tures its essential topology and whose kinetics are analytically tractable. Theanalysis shows – somewhat counter-intuitively – that the flux responsible forthe homeostasis of homocysteine is, in fact, peripheral to the methioninecycle. Elevation of homocysteine arises from reduced activity of methioninesynthase, a vitamin B12-dependent enzyme, however, this does not increaseGSH biosynthesis. The model suggests that the lack of vitamin B12–GSHcorrelation is explained by suppression of activity in the trans-sulfurationpathway that limits the synthesis of cysteine and GSH from homocysteine.We hypothesize this ‘cysteine-block’ is an essential consequence of vitaminB12 deficiency. It can be clinically relevant to appreciate that these secondaryeffects of vitamin B12 deficiency could be central to its pathophysiology.

EVALUATION OF SERUM VITAMIN B12 LEVELS IN TYPE 2 DIABETES PATIENTS ON METFORMIN THERAPY ATTENDING A TERTIARY CARE HOSPITAL

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Anand Kalakappa Koppad

2017-11-01

Full Text Available BACKGROUND Type 2 Diabetes Mellitus (T2DM is an endocrine disorder and a heterogeneous group of syndromes characterised by an elevation of fasting blood glucose that is caused by a relative or absolute deficiency in insulin. Serum vitamin B12 levels have been reported to be inversely associated with the dose and duration of metformin use. Vitamin B12 deficiency is a treatable condition. However, there is insufficient data regarding prevalence of vitamin B12 deficiency in the South Indian population. Hence, the study was undertaken to evaluate serum vitamin B12 levels in T2DM on metformin therapy. MATERIALS AND METHODS A total of 100 T2DM patients attending Outpatient Department (OPD or admitted under Department of General Medicine of KIMS, Hubli, during the time period of 2 years were taken for study considering the inclusion and exclusion criteria. Qualifying patients underwent detailed history, clinical examination, routine investigation and vitamin B12 estimation. RESULTS Majority were in the age group of 45-59 years making 42% of the total. The age group in most patients having vitamin B12 deficiency was >60 years. Males had more vitamin B12 deficiency forming 54.5%. Vitamin B12 deficiency was more in hypertensive group accounting for 71.4%, which was statistically significant. Most of the vitamin B12 deficiency patients had diabetes duration >10 years. Most of the vitamin B12 deficient patients were taking metformin therapy for longer years (≥10 years and in higher dose (>2 g/day. Most of the vitamin B12 deficient diabetes patients were overweight forming 52.5% of the total. CONCLUSION Longer duration of diabetes increases the risk of developing vitamin B12 deficiency on metformin therapy. The higher dose of metformin intake had inverse relation with vitamin B12 levels. Longer duration of metformin intake causes vitamin B12 deficiency and hence should be screened for vitamin B12 deficiency and can be supplemented with vitamin B12.

Smoking Discriminately Changes the Serum Active and Non-Active Forms of Vitamin B12

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Niloofar Shekoohi

2017-08-01

Full Text Available Smoking may modify the appetite, and consequently affect nutrient intake and serum micronutrients. The effect of smoking on vitamin B12 status has been considered in several studies. The research proposed that organic nitrites, nitro oxide, cyanides, and isocyanides of cigarette smoke interfere with vitamin B12 metabolism, and convert it to inactive forms. This research was carried out to determine the serum level of active and inactive forms of vitamin B12 in male smokers in comparison with male nonsmokers. This is a case-control study, in which the participants were 85 male smokers and 85 male nonsmokers. The serum levels of total and active form of vitamin B12 were measured. Dietary intake was recorded by a quantitative food frequency questionnaire and one-day 24-hour dietary recall method. Independent two sample T test was used to compare quantitative variables between the case and control groups. The serum level of total vitamin B12 was not significantly different between two groups, but serum level of active form of vitamin B12 in the smoking group was significantly lower than non-smoking group (P<0.001. This is one of the first studies that evaluated the serum level of active form of vitamin B12 in smokers in the Iranian community. The results of this study identified that serum level of total vitamin B12 might be not different between smoking and non-smoking people, but the function of this vitamin is disturbed in the body of smokers through the reduction of serum level of active form of vitamin B12.

Brucella melitensis VirB12 recombinant protein is a potential marker for serodiagnosis of human brucellosis.

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Mirkalantari, Shiva; Zarnani, Amir-Hassan; Nazari, Mahboobeh; Irajian, Gholam Reza; Amirmozafari, Nour

2017-03-03

The numerous drawbacks of current serological tests for diagnosis of brucellosis which mainly results from cross reactivity with LPS from other gram-negative bacteria have generated an increasing interest to find more specific non-LPS antigens. Previous studies had indicated that Brucella VirB12 protein, a cell surface protein and component of type IV secretion system, induces antibody response during animal infection. However, this protein has not yet been tested as a serological diagnostic marker in human brucellosis. Recombinant VirB12 protein was prepared and evaluated the efficacy of it in an indirect enzyme-linked immunosorbent assay (ELISA) for brucellosis with sera collected from different region of Iran and the results were compared with a commercial ELISA kit. Sera from human brucellosis patients strongly reacted to the purified recombinant VirB12. The sensitivity, specificity, accuracy, negative predictive value and positive predictive value of recombinant VirB12-based ELISA related to the commercial-ELISA method were 87.8, 94, 90, 80 and 96.6% respectively. We concluded that antigenic VirB12 have a property value that can be considered as a candidate for using in serodiagnostic tests for human brucellosis.

Nitrous Oxide Abuse and Vitamin B12 Action in a 20-Year-Old Woman: A Case Report.

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Duque, Miriam Andrea; Kresak, Jesse L; Falchook, Adam; Harris, Neil S

2015-01-01

Herein, we report a case of a 20-year-old (ethnicity not reported) woman with a history of nitrous oxide abuse and clinical symptoms consistent with spinal cord subacute combined degeneration with associated low serum concentrations of vitamin B12, elevated methylmalonic acid levels, and radiologic evidence of demyelination of the dorsal region of the spinal column. The health of the patient improved dramatically with B12 supplementation. In this case, we discuss the interaction of nitrous oxide with the enzymatic pathways involved in the biochemistry of vitamin B12. Copyright© by the American Society for Clinical Pathology (ASCP).

Smoking Discriminately Changes the Serum Active and Non-Active Forms of Vitamin B12.

Science.gov (United States)

Shekoohi, Niloofar; Javanbakht, Mohammad Hassan; Sohrabi, Marjan; Zarei, Mahnaz; Mohammadi, Hamed; Djalali, Mahmoud

2017-06-01

Smoking may modify the appetite, and consequently affect nutrient intake and serum micronutrients. The effect of smoking on vitamin B12 status has been considered in several studies. The research proposed that organic nitrites, nitro oxide, cyanides, and isocyanides of cigarette smoke interfere with vitamin B12 metabolism, and convert it to inactive forms. This research was carried out to determine the serum level of active and inactive forms of vitamin B12 in male smokers in comparison with male nonsmokers. This is a case-control study, in which the participants were 85 male smokers and 85 male nonsmokers. The serum levels of total and active form of vitamin B12 were measured. Dietary intake was recorded by a quantitative food frequency questionnaire and one-day 24-hour dietary recall method. Independent two sample T test was used to compare quantitative variables between the case and control groups. The serum level of total vitamin B12 was not significantly different between two groups, but serum level of active form of vitamin B12 in the smoking group was significantly lower than non-smoking group (Psmokers in the Iranian community. The results of this study identified that serum level of total vitamin B12 might be not different between smoking and non-smoking people, but the function of this vitamin is disturbed in the body of smokers through the reduction of serum level of active form of vitamin B12.

The synthesis, structure, and properties of 5,6,11,12-tetraarylindeno[1,2-b]fluorenes and their applications as donors for organic photovoltaic devices

KAUST Repository

Lo, Yuan-Chih; Ting, Hao-Chun; Li, Ya-Ze; Li, Yi-Hua; Liu, Shun-Wei; Huang, Kuo-Wei; Wong, Ken-Tsung

2016-01-01

The synthesis, structure, and properties of three new 5,6,11,12-tetraarylindeno[1,2-b]fluorenes are reported. The highly twisted conformations between an indeno[1,2-b]fluorene core and peripheral aryl substitutions endow these indeno[1,2-b]fluorene derivatives with good photostability for use as electron donors for vacuum-deposited photovoltaic devices. The optimized device based on a TAInF2 donor blended with C70 as an electron acceptor produces a high open-circuit voltage (>0.9 V) and a power conversion efficiency of 2.91%. This work demonstrates the first application of an indenofluorene derivative as an electron donor in organic solar cells.

The synthesis, structure, and properties of 5,6,11,12-tetraarylindeno[1,2-b]fluorenes and their applications as donors for organic photovoltaic devices

KAUST Repository

Lo, Yuan-Chih

2016-12-01

The synthesis, structure, and properties of three new 5,6,11,12-tetraarylindeno[1,2-b]fluorenes are reported. The highly twisted conformations between an indeno[1,2-b]fluorene core and peripheral aryl substitutions endow these indeno[1,2-b]fluorene derivatives with good photostability for use as electron donors for vacuum-deposited photovoltaic devices. The optimized device based on a TAInF2 donor blended with C70 as an electron acceptor produces a high open-circuit voltage (>0.9 V) and a power conversion efficiency of 2.91%. This work demonstrates the first application of an indenofluorene derivative as an electron donor in organic solar cells.

Elucidation of roles for vitamin B ₁₂ in regulation of folate, ubiquinone, and methionine metabolism

Energy Technology Data Exchange (ETDEWEB)

Romine, Margaret F.; Rodionov, Dmitry A.; Maezato, Yukari; Anderson, Lindsey N.; Nandhikonda, Premchendar; Rodionova, Irina A.; Carre, Alexandre; Li, Xiaoqing; Xu, Chengdong; Clauss, Therese R. W.; Kim, Young-Mo; Metz, Thomas O.; Wright, Aaron T.

2017-01-30

Only a small fraction of vitamin B12-requiring organisms are able to synthesize B12 de novo, making it a common commodity in microbial communities. Initially recognized as an enzyme cofactor of a few enzymes, recent studies have revealed additional B12-binding enzymes and regulatory roles for B12. Here we report the development and use of a B12-based chemical probe to identify B12-binding proteins in a nonphototrophic B12-producing bacterium. Two unexpected discoveries resulted from this study. First, we identified a new light-sensing B12-binding transcriptional regulator and demonstrated that it controls folate and ubiquinone biosynthesis. Second, our probe captured proteins involved in folate, methionine, and ubiquinone metabolism suggesting that it may play a role as an allosteric effector of these processes. These metabolic processes produce precursors for synthesis of DNA, RNA, and protein. Thereby, B12 modulates growth, and by limiting its availability to auxotrophs, B12-producing organisms may facilitate coordination of community metabolism.

Vitamin B-12 concentration, memory performance, and hippocampal structure in patients with mild cognitive impairment.

Science.gov (United States)

Köbe, Theresa; Witte, A Veronica; Schnelle, Ariane; Grittner, Ulrike; Tesky, Valentina A; Pantel, Johannes; Schuchardt, Jan Philipp; Hahn, Andreas; Bohlken, Jens; Rujescu, Dan; Flöel, Agnes

2016-04-01

Low-normal concentrations of vitamin B-12 (VitB12) may be associated with worse cognition. However, previous evidence has been mixed, and the underlying mechanisms remain unclear. We determined whether serum VitB12 concentrations within the normal range were linked to memory functions and related neuronal structures in patients with mild cognitive impairment (MCI). In a cross-sectional design, we assessed 100 amnestic MCI patients (52 women; age range: 50-80 y) with low- and high-normal VitB12 concentration (median split: 304 pmol/L) for memory functions with the use of the Auditory Verbal Learning Test. MRI was performed at 3 tesla (n= 86) for the estimation of the volume and microstructure of the hippocampus and its subfields as indicated by the mean diffusivity on diffusion-weighted images. With the use of a mediation analysis, we examined whether the relation between VitB12 and memory performance was partially explained by volume or microstructure. MCI patients with low-normal VitB12 showed a significantly poorer learning ability (P= 0.014) and recognition performance (P= 0.008) than did patients with high-normal VitB12. Also, the microstructure integrity of the hippocampus was lower in patients with low-normal VitB12, mainly in the cornu ammonis 4 and dentate gyrus region (P= 0.029), which partially mediated the effect of VitB12 on memory performance (32-48%). Adjustments for age, sex, education, apolipoprotein E e4 status, and total homocysteine, folate, and creatinine did not attenuate the effects. Low VitB12 concentrations within the normal range are associated with poorer memory performance, which is an effect that is partially mediated by the reduced microstructural integrity of the hippocampus. Future interventional trials are needed to assess whether supplementation of VitB12 may improve cognition in MCI patients even in the absence of clinically manifested VitB12 deficiency. This trial was registered at clinicaltrials.gov as NCT01219244. © 2016

Dual pathology as a result of spinal stenosis and vitamin B12 deficiency.

Science.gov (United States)

Patel, Mohammed Shakil; Rasul, Zurqa; Sell, Philip

2011-12-01

Vitamin B12 deficiency can confound the clinical assessment of patients presenting with features of spinal disorders. Speciality practice within spinal surgery may lead the clinician to a focus upon spinal explanations for symptoms and that belief may be reinforced by supporting imaging. In the presence of mainly sensory symptoms consideration and exclusion of non surgical causes needs to occur. This study aimed at identifying the prevalence of vitamin B12 deficiency; the presence of dual pathology on imaging performed; the implementation of replacement therapy and their subsequent clinical response as perceived by patients. This was performed through a retrospective review of patients presenting to specialist spine out-patient clinics over a 4-year period via access to pathology reports followed by a telephone survey. 457 patients were investigated of which 8.5% were vitamin B12 deficient. 70% of patients had repeat levels and 31% continued to be deficient. 26% of these patients were not placed on any supplemental therapy. 72% of patients on treatment had self perceived improved outcomes as compared with 55% not on treatment. 73% of patients underwent MRI/CT imaging. 59% of which had evidence of spinal stenosis. In older patients with sensory symptoms, the coexistence of B12 deficiency should be considered. Detection of deficiency with consequent treatment results in better global outcomes than no treatment. Unless the correct blood test is done, the pathology will remain undetected, and patients may continue with their primary symptoms despite high-risk spinal surgical procedures.

RP-HPLC Determination of vitamins B1, B3, B6, folic acid and B12 in multivitamin tablets

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SOTE VLADIMIROV

2005-10-01

Full Text Available Abstract:Asimple and sensitive reversed-phase, ion-pair HPLC method was developed and validated for the simultaneous determination of B-group vitamins, thiamine chloride hydrochloride (B1, nicotinamide (B3, pyridoxine hydrochloride (B6 and folic acid in Pentovit® coated tablets. The cyanocobalamine (B12 was determined separately, because of its low concentration in the investigated multivitamin preparation. RP-HPLC analysis was performed with a LKB 2150 HPLC system, equipped with a UV/VIS Waters M484 detector. The procedures for the determination of B1, B2, B6 and folic acid were carried out on a Supelcosil ABZ+ (15 cm 4.6 mm; 5 µm column with methanol-5mM heptanesulphonic acid sodium salt 0.1%triethylamine TEA(25:75 V/V; pH 2.8 as themobile phase. For the determination of B12 a Suplex pKb-100 (15 cm 4.6 mm; 5 µm column andmethanol–water (22:78 V/V as themobile phase were used. The column effluentsweremonitored at 290 nm for B 1, B3, B6 and folic acid, and at 550 nm for B12. The obtained results and statistical parameters for all the investigated vitamins of the B-group in Pentovit® coated tablets were satisfactory and ranged from 90.4 % to 108.5 % (RSD. from 0.5% to 4.1 %. The parameters for the validation of the methods are given.

Engineering a vitamin B12 high-throughput screening system by riboswitch sensor in Sinorhizobium meliloti.

Science.gov (United States)

Cai, Yingying; Xia, Miaomiao; Dong, Huina; Qian, Yuan; Zhang, Tongcun; Zhu, Beiwei; Wu, Jinchuan; Zhang, Dawei

2018-05-11

As a very important coenzyme in the cell metabolism, Vitamin B 12 (cobalamin, VB 12 ) has been widely used in food and medicine fields. The complete biosynthesis of VB 12 requires approximately 30 genes, but overexpression of these genes did not result in expected increase of VB 12 production. High-yield VB 12 -producing strains are usually obtained by mutagenesis treatments, thus developing an efficient screening approach is urgently needed. By the help of engineered strains with varied capacities of VB 12 production, a riboswitch library was constructed and screened, and the btuB element from Salmonella typhimurium was identified as the best regulatory device. A flow cytometry high-throughput screening system was developed based on the btuB riboswitch with high efficiency to identify positive mutants. Mutation of Sinorhizobium meliloti (S. meliloti) was optimized using the novel mutation technique of atmospheric and room temperature plasma (ARTP). Finally, the mutant S. meliloti MC5-2 was obtained and considered as a candidate for industrial applications. After 7 d's cultivation on a rotary shaker at 30 °C, the VB 12 titer of S. meliloti MC5-2 reached 156 ± 4.2 mg/L, which was 21.9% higher than that of the wild type strain S. meliloti 320 (128 ± 3.2 mg/L). The genome of S. meliloti MC5-2 was sequenced, and gene mutations were identified and analyzed. To our knowledge, it is the first time that a riboswitch element was used in S. meliloti. The flow cytometry high-throughput screening system was successfully developed and a high-yield VB 12 producing strain was obtained. The identified and analyzed gene mutations gave useful information for developing high-yield strains by metabolic engineering. Overall, this work provides a useful high-throughput screening method for developing high VB 12 -yield strains.

Generation of a Circumstellar Gas Disk by Hot Jupiter WASP-12b

Science.gov (United States)

Debrecht, Alex; Carroll-Nellenback, Jonathan; Frank, Adam; Fossati, Luca; Blackman, Eric G.; Dobbs-Dixon, Ian

2018-05-01

Observations of transiting extra-solar planets provide rich sources of data for probing the in-system environment. In the WASP-12 system, a broad depression in the usually-bright MgII h&k lines has been observed, in addition to atmospheric escape from the extremely hot Jupiter WASP-12b. It has been hypothesized that a translucent circumstellar cloud is formed by the outflow from the planet, causing the observed signatures. We perform 3D hydrodynamic simulations of the full system environment of WASP-12, injecting a planetary wind and stellar wind from their respective surfaces. We find that a torus of density high enough to account for the lack of MgII h&k line core emission in WASP-12 can be formed in approximately 13 years. We also perform synthetic observations of the Lyman-alpha spectrum at different points in the planet's orbit, which demonstrate that significant absorption occurs at all points in the orbit, not just during transits, as suggested by the observations.

Axial charge of the weak nucleon current extracted from the β decays of spin aligned 12B and 12N

International Nuclear Information System (INIS)

Yamaguchi, Takayuki

1998-01-01

The alignment correlation terms in the β-ray angular distributions of the 12 B and 12 N mirror nuclei have been precisely measured, in order to investigate the mesonic effect in the axial charge matrix element. The spin alignments were created with the spin manipulation technique in the β-NMR method, which has been improved based on the recent studies of hyperfine interactions of 12 B and 12 N in a Mg crystal. From the sum of the alignment correlation terms, the ratio of the axial charge to the Gamow-Teller term was determined to be y = 4.66 ± 0.06(stat) ± 0.13(syst). The present result gives clear evidence of the mesonic effect in the axial charge and even more shows 16 ± 6% enhancement over the full calculation which includes the meson exchange effect and the core polarization effect. A possible mass renormalization for the decaying nucleon in a finite nucleon density explains this enhancement. (author)

Vitamin B-12 and Depression: Are They Related?

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... al. Nutritional aspects of depression. Cellular Physiology and Biochemistry. 2015;37:1029. Vitamin B12. Natural Medicines. https:// ... Clinic logo are trademarks of Mayo Foundation for Medical Education and Research. © 1998-2018 Mayo Foundation for ...

A triple isotope technique for estimation of fat and vitamin B12 malabsorption in Chrohn's disease

International Nuclear Information System (INIS)

Pedersen, N.T.; Rannem, T.

1991-01-01

A test for simultaneous estimation of vitamin B 12 and fat absorption from stool samples was investigated in 25 patients with severe diarrhoea after operation for Chrohn's disease. 51 CrCl 3 was ingested as a non-absorbable marker, 58 Co-cyanocobalamin as vitamin B 12 tracer, and 14 C-triolein as lipid tracer. Faeces were collected separately for three days. Some stool-to-stool variation in the 58 Co/ 51 Cr and 14 C/ 51 Cr ratios was seen. When the 58 Co-B 12 and 14 C-triolein excretion was estimated in samples of the two stools with the highest activities of 51 Cr, the variations of the estimates were less than ±10% and ±15% of the doses ingested, respectively. 12 of the 25 patients were not able to collect faeces and urine quantitatively and separately. However, in all patients faeces with sufficient radioactivity for simultaneous estimation of faecal 58 Co-B 12 and 14 C-triolein excretion from stool samples were obtained. 16 refs., 3 figs., 1 tab

Reposição de vitamina B12 reduz comportamento depressivo induzido em ratos jovens = Vitamin B12 replacement therapy reduces induced depressive behavior in young rats

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Brito, Adriana Maria de Oliveira

2016-01-01

Conclusões: A depleção suave de vitamina B12 na dieta, em nível não indutor de anemia, favoreceu o estado depressivo em ratos jovens, enquanto a sua suplementação na situação de depleção reverteu esse quadro. Em condições de nutrição adequada, entretanto, a suplementação dessa vitamina não exerceu efeito sobre o estado depressivo. Estes resultados estimulam a realização de mais estudos que aprofundem a avaliação das relações entre vitamina B12 e depressão em jovens. Além disso, este estudo também abre perspectivas para um novo modelo experimental de depressão, induzida por depleção de vitamina B12

Serum vitamin B12, folic acid and ferritin levels in patients with migraine

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Abdullah Acar

2011-06-01

Full Text Available OBJECTIVE: It has been reported that disability due to migraine may be reduced with homocysteine-lowering treatment including folic acid and vitamin B12. In addition, recently the periaqueductal gray matter iron deposits have been found to be increased in migraine patients. There are few studies regarding vitamin B12, folic acid, ferritin and transferrin levels in patients with migraine. The aims of this study was to measure vitamin B12, folic acid, ferritin and transferrin levels in patients with migraine and compare them with the control group. METHODS: Fifty-one consecutive newly diagnosed migraine patients who did not receive any vitamin supplement medication were enrolled. The study group consisted of 51 patients, suffering from migraine with aura (n= 23 and migraine without aura (n= 28. The control group consisted of 28 healthy participants without history of headache, anemia and vitamin supplement. Serum vitamin B12, folic acid, ferritin and transferin levels were measured using a chemiluminescence method. RESULTS: Migraine patients had significantly lower concentrations of vitamin B12 and folic acid compared with the healthy controls (for vitamin B12; 215.6±133.7 pg/ml vs. 289.9±12 pg/ml, respectively, p=0.005; for folic acid; 6.74 ± 4.31 pg/ml vs. 8.47 ± 1.85 pg/ml, respectively, p=0.048. The vitamin B12 levels were found to be significantly lower during attacks in migraine patients than in interictal periods (177.3 ± 139.2 pg/ml vs 252.5 ± 119.5 pg/ml, p=0.043. There were no differences in folic acid, ferritin, and transferritin levels between during attacks and in interictal period of patients with migraine (p>0.05. The ferritin levels were found to be significantly lower during attacks in migraine patients than in interictal periods (43.4 ± 41.1 mg/ml, vs 75.4 ± 51.7, mg/ml, p=0.018. CONCLUSION: Migraine patients had lower serum vitamin B12 and folic acid levels than healthy subjects. These findings supported that vitamin B12

Investigations with a simplified method for radiometric determination of vitamin B12 in body fluids and feeding stuffs

International Nuclear Information System (INIS)

Menke, K.H.; Kohlberger, G.; Koenemund, A.

1979-01-01

A modified method for radiometrical determination of vitamin B 12 is described, which in difference to the known methods is based on measurement of free B 12 after absorption to albumin-coated charcoal instead of measurement of intrinsic factor B 12 -complex. The conditions for extraction from serum, milk, rumen-liquor and urine have been investigated and the effect of pH on IF-B 12 -binding in presence of these body fluids examined. Parallel microbiological determinations (O.m.- and L.1.-test) were in good correlation (r = 0,93-0,97) to radiometrically determined B 12 -contents in milk and rumen-liquor, but not to that in serum of dairy cows (r = 0,54-0,82). The analytical procedures are given in detail. (orig.) [de

Forms of vitamin B12 in radioisotope dilution assays

International Nuclear Information System (INIS)

Begley, J.A.; Hall, C.A.

1981-01-01

Since the presence of analogues of vitamin B 12 (B 12 , cobalamin, Cbl) has been postulated as the basis for the high values obtained by some radioisotope dilution assays (RIDA) of serum Cbl, serum was examined for analogues. None could be demonstrated in the extracts of serum prepared for RIDA as sought by both direct and indirect techniques. The natural forms of serum Cbl were converted to cyanocobalamin (CN Cbl) by this process of extraction which included cyanide (CN). The correctly performed RIDA for Cbl based on R binder gave higher values than a RIDA based on intrinsic factor or than by bioassay. By exclusion, the difference appeared to be due to unidentified factors rather than the presence of analogues. (author)

A combined supplementation of vitamin B12 and omega-3 fatty acids across two generations improves cardiometabolic variables in rats.

Science.gov (United States)

Khaire, Amrita; Rathod, Richa; Randhir, Karuna; Kale, Anvita; Joshi, Sadhana

2016-09-14

Our earlier studies indicate that micronutrients (vitamin B12, folic acid) and omega-3 fatty acids especially docosahexaenoic acid (DHA) are interlinked in one carbon cycle. The present study examines the effects of a sustained vitamin B12 deficiency/supplementation in the presence of omega-3 fatty acids across two generations on the pregnancy outcome and cardiometabolic profile [blood pressure, plasma lipid profile (cholesterol and triglycerides), plasma/liver fatty acid profile and hepatic lipid metabolism] in the second generation adult Wistar rat offspring. Two generations of animals were fed the following diets: control; vitamin B12 deficient; vitamin B12 supplemented; vitamin B12 deficient diet supplemented with omega-3 fatty acids; vitamin B12 and omega-3 fatty acid supplemented diets. Male offspring were sacrificed at 3 months of age. Vitamin B12 deficiency lowered the weight gain (p blood pressure, and lowered the levels of plasma/liver DHA (p lipid profile. Vitamin B12 supplementation showed weight gain, blood pressure and the fatty acid profile similar to the control. However, it increased (p acid supplementation to the vitamin B12 deficient group lowered the weight gain although the levels of cardiometabolic variables were comparable to the control. Omega-3 fatty acid supplementation in the presence of vitamin B12 improved the pregnancy outcome and all cardio-metabolic variables. Our study highlights the adverse effects of sustained vitamin B12 deficiency across two generations on the pregnancy outcome, fatty acid profile and blood pressure while a combined supplementation of vitamin B12 and omega-3 fatty acids is beneficial.

Total serum homocysteine as an indicator of vitamin B12 and folate status

International Nuclear Information System (INIS)

Chu, R.C.; Hall, C.A.

1988-01-01

Presented is a modification of an assay for total serum homocysteine (Hcy) in which the Hcy plus radioactive adenosine is converted enzymatically to labeled S-adenosylhomocysteine (AdoHcy). The modifications included a commerical source for the AdoHcy hydrolase, adenosine labeled with either 14 C or 3 H, and separation of the AdoHcy by thin layer chromatography. The assay was sensitive to 25 pmol. Hcy levels in sera from 18 controls ranged from 6.9 to 12.1 mumol/L with a mean of 9.1 and a SD of 1.5 mumol/L. The total serum Hcy was increased in vitamin B12 and folate deficiency. The level was high in congenital defects of vitamin B12 metabolism, blocking the methylation of Hcy regardless of the serum vitamin B12 levels, but was normal in the absence of tissue deficiency even if the serum vitamin B12 levels were low. The procedure has been found practical in two years of use and requires only 0.1 mL of serum

Targeting of human interleukin-12B by small hairpin RNAs in xenografted psoriatic skin

Directory of Open Access Journals (Sweden)

Jakobsen Maria

2011-02-01

Full Text Available Abstract Background Psoriasis is a chronic inflammatory skin disorder that shows as erythematous and scaly lesions. The pathogenesis of psoriasis is driven by a dysregulation of the immune system which leads to an altered cytokine production. Proinflammatory cytokines that are up-regulated in psoriasis include tumor necrosis factor alpha (TNFα, interleukin-12 (IL-12, and IL-23 for which monoclonal antibodies have already been approved for clinical use. We have previously documented the therapeutic applicability of targeting TNFα mRNA for RNA interference-mediated down-regulation by anti-TNFα small hairpin RNAs (shRNAs delivered by lentiviral vectors to xenografted psoriatic skin. The present report aims at targeting mRNA encoding the shared p40 subunit (IL-12B of IL-12 and IL-23 by cellular transduction with lentiviral vectors encoding anti-IL12B shRNAs. Methods Effective anti-IL12B shRNAs are identified among a panel of shRNAs by potency measurements in cultured cells. The efficiency and persistency of lentiviral gene delivery to xenografted human skin are investigated by bioluminescence analysis of skin treated with lentiviral vectors encoding the luciferase gene. shRNA-expressing lentiviral vectors are intradermally injected in xenografted psoriatic skin and the effects of the treatment evaluated by clinical psoriasis scoring, by measurements of epidermal thickness, and IL-12B mRNA levels. Results Potent and persistent transgene expression following a single intradermal injection of lentiviral vectors in xenografted human skin is reported. Stable IL-12B mRNA knockdown and reduced epidermal thickness are achieved three weeks after treatment of xenografted psoriatic skin with lentivirus-encoded anti-IL12B shRNAs. These findings mimick the results obtained with anti-TNFα shRNAs but, in contrast to anti-TNFα treatment, anti-IL12B shRNAs do not ameliorate the psoriatic phenotype as evaluated by semi-quantitative clinical scoring and by

Blood homocysteine, folic acid, vitamin B12 and vitamin B6 levels in psoriasis patients

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Meltem Uslu

2017-09-01

Full Text Available Background and Design: Homocysteine, a sulfur-containing amino acid, is known to be related with autoimmunity-inflammation, cardiovascular disease and DNA methylation. In this case-control study, we aimed to determine plasma homocysteine, folic acid, vitamin B12 and vitamin B6 levels in patients with psoriasis. Materials and Methods: Smoking, alcohol and coffee consumption habits were recorded in adult patients with plaque-type psoriasis and age- and sex-matched controls. Height and weight measurements were performed and Psoriasis Area and Severity Index (PASI scores were calculated. Fasting venous blood samples were collected to determine homocysteine, folic acid, vitamin B12, vitamin B6, glucose, total cholesterol, triglyceride, high density lipoprotein (HDL, erythrocyte sedimentation rate (ESR, and C-reactive protein (CRP levels. Results: There was no significant difference between psoriasis patients (n=43 and controls (n=47 in body mass index and alcohol and coffee consumption. Smoking rate was significantly high in psoriasis patients. The median PASI score was 10.0 (8.3-12.8. Plasma homocysteine, folic acid, vitamin B12, vitamin B6, total cholesterol, triglyseride, ESR and CRP values were not significantly different between patients and the controls. HDL level was low in psoriasis patients (p=0.001. Plasma homocysteine level was higher in males than in females. There was no relationship of homocysteine levels with patient’s age, PASI scores, ESR, CRP values and lipids. Homocysteine levels were inversely related with folic acid and vitamin B12 (p=0.000, r=-0.436, p=0.047, r=-0.204, respectively. We did not find any relationship between homocysteine and vitamin B6 levels. Conclusion: There was no increase in plasma homocysteine levels in psoriasis patients we followed up. Homocysteine level increases in inflammatory disorders and this increase is accepted as a cardiovascular disease marker. Homocysteine homeostasis may be balanced in our

Non-detection of a Helium Exosphere for the Hot Jupiter WASP-12b

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Kreidberg, Laura; Oklopčić, Antonija

2018-06-01

An exosphere was recently detected around the exoplanet WASP-107b, a low-density, warm Neptune, based on an absorption feature from metastable helium (which has a vacuum wavelength of 10833 \\AA). Inspired by the WASP-107b detection, we reanalyzed archival HST observations of another evaporating exoplanet, WASP-12b, to search for signs of helium in its exosphere. We find no significant increase in transit depth at 10833 \\AA. We compare this result to theoretical predictions from a 1D model, and find that the expected helium feature amplitude is small, in agreement with the observed non-detection. We discuss possible explanations for why the helium feature is weaker for WASP-12b than WASP-107b, and conclude that the amplitude of the signal is highly sensitive to the stellar spectrum and the geometry of the evaporating gas cloud. These considerations should be taken into account in the design of future searches for helium exospheres.

[Carcinogenesis and its mechanism of mutant-type[12Asp]K-ras4B gene].

Science.gov (United States)

Gui, Li-ming; Wei, Li-hui; Zhang, Ying-mei; Wang, Jian-liu; Wang, Ying; Chen, Ying; Ma, Da-long

2002-01-01

Ras gene plays an important role in the extra- and intra-cellular signal transduction pathway. It mediates series cascade reactions, and eventually actives transcriptional factors in nucleus. It is unknown on the mechanism of carcinogenesis of Ras gene in endometrial carcinoma, though K-ras mutant is very common in endometrial atypical hyperplasia and carcinoma. On basis of discovering the mutation in 12th codon of K-ras in endometrial carcinoma cell line, HEC-1A, we explored the carcinogenesis and molecular mechanism of mutant-type [12Asp] K-ras4B gene. (1) Full-length [12Asp]K-ras4B cDNA was amplified with RT-PCR, then inserted into pcDI eukaryotic expressive vector. (2) Morphological change, growth kinetics in vitro and tumorigencity in nude mice in vivo after-before transfection were observed. (3) To test the cell growth kinetics by methyl thiazolium tetrazolium (MTT) and [3H]thymidine incorporation method. (1) The authors have successfully constructed eukaryotic expression plasmid pcDI-[12Asp] K-ras4B; (2) To confirm that [12Asp] K-ras4B mutant can trigger the neoplastic transformation of NIH3T3 cells by test in vitro and in vivo. (3) After pMCV-RasN17 plasmid, a Ras mutant were transfected into pcDI-[12Asp] K-ras4B cells, the growth of this cell were restrained significantly in comparison with control group. (4) These findings indicate the expression of RafS621A resulted in remarkable inhibition in proliferation of pcDI-[12Asp]K-ras4B cell (P ras4B cell growth (P ras4B gene alone is able to cause neoplastic transformation in NIH3T3 cells in vitro and in vivo. (2) [12Asp]K-ras4B-induced NIH3T3 cells neoplastic transformation required Raf signaling pathway.

Low-temperature heat capacity and thermodynamic functions of vitamin B12

International Nuclear Information System (INIS)

Knyazev, A.V.; Smirnova, N.N.; Plesovskikh, A.S.; Shushunov, A.N.; Knyazeva, S.S.

2014-01-01

Graphical abstract: - Highlights: • Temperature dependence of heat capacity of vitamin B 12 has been measured by precision adiabatic vacuum calorimetry. • The thermodynamic functions of the vitamin B 12 have been determined for the range from T → 0 to 343 K. • The character of heterodynamics of structure was detected. • The thermal stability of cyanocobalamin was studied by differential scanning calorimetry. - Abstract: In the present work temperature dependence of heat capacity of vitamin B 12 (cyanocobalamin) has been measured for the first time in the range from 6 to 343 K by precision adiabatic vacuum calorimetry. Based on the experimental data, the thermodynamic functions of the vitamin B 12 , namely, the heat capacity, enthalpy H°(T) − H°(0), entropy S°(T) − S°(0) and Gibbs function G°(T) − H°(0) have been determined for the range from T → 0 to 343 K. The value of the fractal dimension D in the function of multifractal generalization of Debye's theory of the heat capacity of solids was estimated and the character of heterodynamics of structure was detected. The thermal stability of cyanocobalamin was also studied by differential scanning calorimetry

Vitamin B 12 levels in patients with type 2 diabetes mellitus on ...

African Journals Online (AJOL)

Methods: Serum vitamin B12 level was determined using high performance liquid chromatography (HPLC) in 81 T2DM patients who have been on metformin for 5 years or more. Vitamin B12 deficiency was defined as serum concentration of 300 pg/dl as normal.

Vitamin B12 supplementation and cognitive scores in geriatric patients with Mild Cognitive Impairment

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Komal Chauhan

2016-09-01

Full Text Available Background: The Neurodegenerative diseases are increasingly affecting the elderly with a severe impact on their brain health. There is a wide gap in supplementation based studies for increasing the cognition levels of the geriatric population, especially in developing countries like India which are at extreme risk of developing neurological disorders. And recently Vitamin B12 has drawn considerable attention due to its ability to improve the cognitive status. Current literature has linked the possibility of alleviating neurological disorders in the elderly with effective vitamin B12 management. Abundant animal and human models have proved that supplementation of vitamin B12 is beneficial for the restoration of cognitive functions. Objective: To supplement vitamin B12 deficient mild cognitively impaired geriatric patients with injectable doses of vitamin B12 followed by impact evaluation. Methods: Screening of the mild cognitively impaired patients was carried out using the Mini- Mental State Examination and Yamaguchi Fox Pigeon Imitation test. Baseline information was elicited from the patients residing in urban Vadodara (a district in the state of Gujarat, India. This included socio-demographic, medical and drug history, anthropometric and physical activity pattern, in addition to biochemical parameters comprising of serum vitamin B12 and glycated haemoglobin profile. A sub-sample of 60 patients with mild cognitive impairment (MCI demonstrating severe vitamin B12 deficiency were conveniently enrolled for injectable doses of Vitamin B 12 in the dosage of 1,000 µg every day for one week, followed by 1,000 µg every week for 4 weeks & finishing with 1,000 µg for the remaining 4 months. An intervention six- month after the experiment with all the parameters were elicited. Results: Vitamin B12 supplementation resulted in a significant (p<0.001 improvement in the MMSE scores of the patients with a rise of 9.63% in the total patients. Gender

Vitamin B12 Deficiency and the Role of Gender: A Cross-Sectional Study of a Large Cohort.

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Margalit, Ili; Cohen, Eytan; Goldberg, Elad; Krause, Ilan

2018-01-01

Vitamin B12 deficiency is associated with hematological, neurological, and cardiovascular consequences. Epidemiologic data on these related illnesses indicate gender differences. A cross-sectional study was designed to examine gender differences in vitamin B12 deficiency among a healthy population. Data from healthy individuals aged 18-65, who were provided with a routine medical evaluation during 2000-2014, were retrieved from the medical charts. Individuals with background illnesses and those who had used medications or nutritional supplements were excluded. Vitamin B12 deficiency was defined by 2 cutoff values (206 and 140 pmol/L). The multivariate analysis was adjusted for age, body mass index, estimated glomerular filtration rate, hyperhomocysteinemia, folate deficiency, albumin, and transferrin saturation. Sensitivity analyses were implemented by excluding individuals with anemia, hyperhomocysteinemia, or folate deficiency and by age stratification. In all, 7,963 individuals met the inclusion criteria. Serum vitamin B12 mean levels were 312.36 and 284.31 pmol/L for women and men respectively (p variations are therefore hypothesized to play a role. © 2018 S. Karger AG, Basel.

The Folate-Vitamin B12 Interaction, Low Hemoglobin, and the Mortality Risk from Alzheimer's Disease.

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Min, Jin-Young; Min, Kyoung-Bok

2016-03-21

Abnormal hemoglobin levels are a risk factor for Alzheimer's disease (AD). Although the mechanism underlying these associations is elusive, inadequate micronutrients, particularly folate and vitamin B12, may increase the risk for anemia, cognitive impairment, and AD. In this study, we investigated whether the nutritional status of folate and vitamin B12 is involved in the association between low hemoglobin levels and the risk of AD mortality. Data were obtained from the 1999-2006 National Health and Nutrition Examination Survey (NHANES) and the NHANES (1999-2006) Linked Mortality File. A total of 4,688 participants aged ≥60 years with available baseline data were included in this study. We categorized three groups based on the quartiles of folate and vitamin B12 as follows: Group I (low folate and vitamin B12); Group II (high folate and low vitamin B12 or low folate and high vitamin B12); and Group III (high folate and vitamin B12). Of 4,688 participants, 49 subjects died due to AD. After adjusting for age, sex, ethnicity, education, smoking history, body mass index, the presence of diabetes or hypertension, and dietary intake of iron, significant increases in the AD mortality were observed in Quartile1 for hemoglobin (HR: 8.4, 95% CI: 1.4-50.8), and the overall risk of AD mortality was significantly reduced with increases in the quartile of hemoglobin (p for trend = 0.0200), in subjects with low levels of both folate and vitamin B12 at baseline. This association did not exist in subjects with at least one high level of folate and vitamin B12. Our finding shows the relationship between folate and vitamin B12 levels with respect to the association between hemoglobin levels and AD mortality.

Vitamin B12 assays compared by use of patients sera with low vitamin B12 content

International Nuclear Information System (INIS)

Sheridan, B.L.; Pearce, L.C.

1985-01-01

The authors compared four radioisotope dilution (RD) methods and a microbiological assay for measuring concentrations of vitamin B12 in a selected panel of serum samples from patients known to be deficient in the vitamin. Low (less than 100 ng/L) and borderline (100-180 ng/L) results were similar between methods, but use of the manufacturers recommended ranges for borderline results would have changed the diagnostic classifications for 22 of 38 samples. Results of all the RD methods inter-correlated well, but less so with the microbiological assay. Borderline, nondiagnostic results were common to all methods, and no apparent advantage was gained from using the microbiological assay

Prevalence of Vitamin B12 and Folate Deficiencies and ...

African Journals Online (AJOL)

... 2Faculty of Dentistry, International Branch, 3Department of Internal Medicine & Endocrine and ... Keywords: Vitamin B12 deficiency, Folate deficiency, Homocysteinemia, Elderly population ... gastritis, intestinal malabsorption, pancreatic.

High Prevalence of Vitamin B12 Deficiency and No Folate Deficiency in Young Children in Nepal

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Bernadette N. Ng’eno

2017-01-01

Full Text Available Many children in low- and middle-income countries may have inadequate intake of vitamin B12 and folate; data confirming these inadequacies are limited. We used biochemical, demographic, behavioral and anthropometric data to describe the folate and vitamin B12 concentrations among six- to 23-month-old Nepalese children. Vitamin B12 (serum B12 < 150 pmol/L and folate deficiencies (red blood cell (RBC folate < 226.5 nmol/L were assessed. We used logistic regression to identify predictors of vitamin B12 deficiency. The vitamin B12 geometric mean was 186 pmol/L; 30.2% of children were deficient. The mean RBC folate concentration was 13,612 nmol/L; there was no deficiency. Factors associated with vitamin B12 deficiency included: (a age six to 11 months (adjusted odds ratio (aOR 1.51; 95% confidence interval (CI: 1.18, 1.92 or 12–17 months (aOR 1.38; 95% CI: 1.10, 1.72 compared to 18–23 months; (b being stunted (aOR 1.24; 95% CI: 1.03, 1.50 compared to not being stunted; (c and not eating animal-source foods (aOR 1.85; 95% CI: 1.42, 2.41 compared to eating animal-source foods the previous day. There was a high prevalence of vitamin B12 deficiency, but no folate deficiency. Improving early feeding practices, including the consumption of rich sources of vitamin B12, such as animal-source foods and fortified foods, may help decrease deficiency.

Relationship among plasma vitamin B12 and folic acid levels and coronary artery disease

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Masoomeh Tohidhi

2012-04-01

Full Text Available Background: Hyperhomocysteinemia is a new risk factor for cardiovascular disease. It is a sensitive marker of the vitamin B12 and folate insufficiency. Folate and vitamin B12 may be a protective effect on cardiovascular disease. According to limited data about role of vitamin B12 and folate in coronary artery disease (CAD, we conducted this study to measure these factors in patients with coronary artery disease and in control subjects. Methods: This case-control study was performed on 139 subjects who underwent coronary angiography in Shiraz. Plasma vitamin B12 and folate level were measured and compared between patients with CAD and control subjects. Results: 139 individuals with a mean age 56.99±11.93 were enrolled in this study. 31.2% of them had a normal coronary angiography. Mean plasma level of folate in patients with CAD was lower than control subjects (4.46±1.28 ng/ml versus 5.00±1.81 ng/ml, P = 0.04. Also mean plasma level of vitamin B12 in patients CAD and control subjects were 451.43±138.90 and 503.60±199.35 pg/ml respectively. Although mean level of vitamin B12 in patients with CAD was lower than control group, but it was not statistically significant (P = 0.07. Conclusion: Mean plasma level of vitamin B12 and folate were lower in patients with CAD than control group. It seems that supplementation with this vitamins may be useful in patients with CAD.

High-pressure synthesis and crystal structure of In{sub 3}B{sub 5}O{sub 12}

Energy Technology Data Exchange (ETDEWEB)

Vitzthum, Daniela; Schauperl, Michael; Liedl, Klaus R.; Huppertz, Hubert [Univ. Innsbruck (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie

2017-03-01

Orthorhombic In{sub 3}B{sub 5}O{sub 12} was synthesized in a Walker-type multianvil apparatus under high-pressure/high-temperature conditions of 12.2 GPa and 1500 C. Its structure is isotypic to the rare earth analogs RE{sub 3}B{sub 5}O{sub 12} (RE=Sc, Er-Lu). In the field of indium borate chemistry, In{sub 3}B{sub 5}O{sub 12} is the third known ternary indium borate besides InBO{sub 3} and InB{sub 5}O{sub 9}. The crystal structure of In{sub 3}B{sub 5}O{sub 12} has been determined via single-crystal X-ray diffraction data collected at room temperature. It crystallizes in the orthorhombic space group Pmna with the lattice parameters a=12.570(2), b=4.5141(4), c=12.397(2) Aa, and V=703.4(2) Aa{sup 3}. IR and Raman bands of In{sub 3}B{sub 5}O{sub 12} were theoretically determined and assigned to experimentally recorded spectra.

Radioisotope dilution technique for determination of vitamin B12 in foods

International Nuclear Information System (INIS)

Casey, P.J.; Speckman, K.R.; Ebert, F.J.; Hobbs, W.E.

1982-01-01

A radioisotope dilution (RID) method for the determination of vitamin B 12 is presented. The method combines a standard extraction procedure (AOAC 43.108, 12th ed.) with a commercially available RID assay kit. The method was evaluated on a wide range of fortified and unfortified food products. Recovery studies on both groups yielded average recoveries of 98.1 and 95.8%, respectively. Reproducibility data generated from replicate analysis on both groups gave a relative standard deviation of 6.9% for the fortified group and 9.2% for the unfortified group. For the samples studied, the mean vitamin B 12 content determined by the RID method was 8.01 μ/100 g vs a mean of 7.54 μg/100 g by the AOAC microbiological method; the correlation coefficient was r = 0.983

Recreational Nitrous Oxide Abuse-Induced Vitamin B12 Deficiency in a Patient Presenting with Hyperpigmentation of the Skin

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Tsung-Ta Chiang

2013-06-01

Full Text Available Vitamin B12 deficiency causes skin hyperpigmentation, subacute combined degeneration of the spinal cord, and megaloblastic anemia. Although vitamin B12 deficiency rarely occurs in well-nourished, healthy, young people, nitrous oxide (N2O intoxication is an important cause of vitamin B12 deficiency in this cohort. N2O, a colorless gas used as an anesthetic since the late 19th century because of its euphoric and analgesic qualities, is now used as a recreational drug and is available via the Internet and at clubs. Here, we describe the case of a 29-year-old woman presenting with skin hyperpigmentation as her only initial symptom after N2O abuse for approximately 2 years. N2O intoxication-induced vitamin B12 deficiency was diagnosed based on the skin pigmentation that had manifested over the dorsa of her fingers, toes, and trunk, coupled with myeloneuropathy of the posterior and lateral columns, a low serum vitamin B12 level, an elevated serum homocysteine level, and the N2O exposure revealed while establishing the patient's history. Symptoms improved significantly with vitamin B12 treatment. We recommend that dermatologists consider N2O intoxication-induced vitamin B12 deficiency as a potential cause of skin hyperpigmentation and myeloneuropathy of the posterior and lateral columns in young, otherwise healthy patients. Failure to recognize this presentation may result in inappropriate treatment, thus affecting patients' clinical outcomes.

Investigation of the receptor-mediated endocytosis of transcobalamin/intrinsic factor-vitamin B₁₂ complexes

DEFF Research Database (Denmark)

Beedholm, Rasmus; Grissom, Charles B.; Fedosov, Sergey N.

receptor structure. This receptor is suggested to be regulated by the vitamin B12 level in the cells, which is interesting in relation to cancer growth. The cellular endocytosis of TC- B12 complex by this unknown receptor is being investigated, using confocal microscopy. Fluorescently labeled B12 molecules...... (Oregon green linked to B12) have been synthesized to determine the B12 uptake level in normal and various tumour-derived cells (e.g. Hela cells from cervix epithelioid carcinoma and BN- cells from rat yolk sac sarcoma). Costaining of the B12 binders has been performed using fluorescently labelled...

Electronic structure of the boron fullerene B14 and its silicon derivatives B13Si(+), B13Si(-) and B12Si2: a rationalization using a cylinder model.

Science.gov (United States)

Van Duong, Long; Nguyen, Minh Tho

2016-06-29

Geometric and electronic structures of the boron cluster B14 and its silicon derivatives B13Si(+), B13Si(-), and B12Si2 were determined using DFT calculations (TPSSh/6-311+G(d)). The B12Si2 fullerene, which is formed by substituting two B atoms at two apex positions of the B14 fullerene by two Si atoms, was also found as the global minimum structure. We demonstrated that the electronic structure and orbital configuration of these small fullerenes can be predicted by the wavefunctions of a particle on a cylinder. The early appearance of high angular node MOs in B14 and B12Si2 can be understood by this simple model. Replacement of one B atom at a top position of B14 by one Si atom, followed by the addition or removal of one electron does not lead to a global minimum fullerene structure for the anion B13Si(-) and cation B13Si(+). The early appearance of the 5σ1 orbital in B13Si(+) causes a lower stability for the fullerene-type structure.

Bread cofortified with folic acid and vitamin B-12 improves the folate and vitamin B-12 status of healthy older people: a randomized controlled trial

NARCIS (Netherlands)

Winkels, R.M.; Brouwer, I.A.; Clarke, R.; Katan, M.B.; Verhoef, P.

2008-01-01

Background: Mandatory fortification of flour with folic acid has reduced the number of neural tube defects in North America. Concerns that high intakes of folic acid might mask vitamin B-12 deficiency in older persons have delayed the introduction of fortification in many European countries.

Comparative genomic analyses of nickel, cobalt and vitamin B12 utilization

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Gelfand Mikhail S

2009-02-01

Full Text Available Abstract Background Nickel (Ni and cobalt (Co are trace elements required for a variety of biological processes. Ni is directly coordinated by proteins, whereas Co is mainly used as a component of vitamin B12. Although a number of Ni and Co-dependent enzymes have been characterized, systematic evolutionary analyses of utilization of these metals are limited. Results We carried out comparative genomic analyses to examine occurrence and evolutionary dynamics of the use of Ni and Co at the level of (i transport systems, and (ii metalloproteomes. Our data show that both metals are widely used in bacteria and archaea. Cbi/NikMNQO is the most common prokaryotic Ni/Co transporter, while Ni-dependent urease and Ni-Fe hydrogenase, and B12-dependent methionine synthase (MetH, ribonucleotide reductase and methylmalonyl-CoA mutase are the most widespread metalloproteins for Ni and Co, respectively. Occurrence of other metalloenzymes showed a mosaic distribution and a new B12-dependent protein family was predicted. Deltaproteobacteria and Methanosarcina generally have larger Ni- and Co-dependent proteomes. On the other hand, utilization of these two metals is limited in eukaryotes, and very few of these organisms utilize both of them. The Ni-utilizing eukaryotes are mostly fungi (except saccharomycotina and plants, whereas most B12-utilizing organisms are animals. The NiCoT transporter family is the most widespread eukaryotic Ni transporter, and eukaryotic urease and MetH are the most common Ni- and B12-dependent enzymes, respectively. Finally, investigation of environmental and other conditions and identity of organisms that show dependence on Ni or Co revealed that host-associated organisms (particularly obligate intracellular parasites and endosymbionts have a tendency for loss of Ni/Co utilization. Conclusion Our data provide information on the evolutionary dynamics of Ni and Co utilization and highlight widespread use of these metals in the three

17 CFR 270.12b-1 - Distribution of shares by registered open-end management investment company.

Science.gov (United States)

2010-04-01

... registered open-end management investment company. 270.12b-1 Section 270.12b-1 Commodity and Securities... 1940 § 270.12b-1 Distribution of shares by registered open-end management investment company. (a)(1... the printing and mailing of sales literature; (b) A registered, open-end management investment company...

The complete coenzyme B12 biosynthesis gene cluster of Lactobacillus reuteri CRL 1098

NARCIS (Netherlands)

Santos, dos F.; Vera, J.L.; Heijden, van der R.; Valdez, G.F.; Vos, de W.M.; Sesma, F.; Hugenholtz, J.

2008-01-01

The coenzyme B12 production pathway in Lactobacillus reuteri has been deduced using a combination of genetic, biochemical and bioinformatics approaches. The coenzyme B12 gene cluster of Lb. reuteri CRL1098 has the unique feature of clustering together the cbi, cob and hem genes. It consists of 29

Electric quadrupole interactions on /sup 12/B and /sup 12/N implanted in Mg studied by nuclear depolarization due to level mixing

Energy Technology Data Exchange (ETDEWEB)

Tanihata, I; Kogo, S; Sugimoto, K [Osaka Univ., Toyonaka (Japan). Lab. of Nuclear Studies

1977-04-25

Electric quadrupole interactions on polarized /sup 12/B and /sup 12/N implanted in a Mg single crystal have been studied by a new method in which the nuclear depolarization due to level mixing caused by an external magnetic field is detected.

Serum homocysteine, folate, vitamin B12 and total antioxidant status in vegetarian children.

Science.gov (United States)

Ambroszkiewicz, J; Klemarczyk, W; Chełchowska, M; Gajewska, J; Laskowska-Klita, T

2006-01-01

The results of several studies point to the positive role of vegetarian diets in reducing the risk of diabetes, some cancers and cardiovascular diseases. However, exclusion of animal products in vegetarian diets may affect the cobalamin status and cause an elevation of the plasma homocysteine level. The aim of this study was to assess the effect of vegetarian diets on serum concentrations of homocysteine, folate, vitamin B12 and total antioxidant status (TAS) in children. The study included 32 vegetarians (including 5 vegans), age 2-10 years. Dietary constituents were analyzed using a local nutritional programme. Serum homocysteine, folate and vitamin B12 were determined with fluorescence and chemiluminescence immunoassays. The concentration of TAS was measured by a colorimetric method. Average daily energy intake and the percentage of energy from protein, fat and carbohydrates in the diets of the studied children were just above or similar to the recommended amounts. It could be shown that vegetarian diets contain high concentrations of folate. In vegan diets it even exceeds the recommended dietary allowance. Mean daily intake of vitamin B12 in the studied diets was adequate but in vegans was below the recommended range. The serum concentrations of homocysteine, folate, vitamin B12 and TAS in vegetarian children remained within the physiological range. The presented data indicate that vegetarian children, contrary to adults, have enough vitamin B12 in their diet (excluding vegans) and normal serum concentrations of homocysteine, folate and vitamin B12. Therefore, in order to prevent deficiencies in the future, close monitoring of vegetarian children (especially on a vegan diet) is important to make sure that they receive adequate quantities of nutrients needed for healthy growth.

Measurement of FA and VitB12 in serum by TRFIA and its clinical application

International Nuclear Information System (INIS)

Zhou Jinhong; Wang Huimin

2006-01-01

To investigate the correlation between diseases and the quantity of folic acid(FA) and vitamine B 12 (VitB 12 ) in serum, the quantity of FA and VitB 12 in serum was measured by TR- FIA. The results showed that the levels of FA and VitB 12 in 68 controlled subjects were 20.13±5.72 nmol/L and 240.45±58.23 pmol/L respectively. The levels of FA and VitB 12 in 6 patients with megaloblastic anemia, 26 with medium-terminal gestation femineity, 7 with liver cirrhosis, 10 with gastric ulcerand 31 with cerebral infarction were significant lower than those in the control group. The level of FA in 24 with malignant hematopathy and 57 with malignant tumor was significantly lower but VitB 12 between the 31 patients with iron deficiency anemia and 12 with CAA and the control group. The amount of the FA in 9 patients with chronic atrophic gastritis and 42 blood donors were lower than that in the control. The determination of FA and VitB 12 levels may be quite significant in the diagnosis, therapy and prognosis of diseases. Laboratories should establish the reference values which fit the locals specifically. (authors)

High prevalence of suboptimal vitamin B12 status in young adult women of South Asian and European ethnicity.

Science.gov (United States)

Quay, Teo A W; Schroder, Theresa H; Jeruszka-Bielak, Marta; Li, Wangyang; Devlin, Angela M; Barr, Susan I; Lamers, Yvonne