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Sample records for folate cobalamin cysteine

  1. Iron, folate and cobalamin deficiency in anaemic pregnant females in tertiary care centre at Rawalpindi

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    Khan, D A; Fatima, S; Imran, R; Khan, F A [National Univ. of Science and Technology, Army Medical College, Rawalpindi (Pakistan). Department of Pathology

    2010-01-15

    Background: Anaemia in pregnancy is a common clinical problem contributing to increased maternal and foetal morbidity. This study was carried out to determine frequency of iron, folate and cobalamin deficiency and associated risk factors in the anaemic pregnant females who reported first time during second and third trimester for antenatal check-up in the tertiary care hospital at Rawalpindi. Methods: This case control study was carried out in a tertiary care hospital at Rawalpindi. Two hundred and fifty pregnant women (age: 19-43 years) consisting of 125 anaemic (Hb< 110 g/L) and 125 non-anaemic who reported first time at antenatal clinic were included. Data on socio-demographic characteristics, parity and dietary intake were collected. Complete blood counts were done. Serum ferritin, folate and cobalamin assays were performed by using DPC kits on Immulite-1000. Results: The pregnant women were categorised having mild (Hb up to 54%), moderate (Hb up to 36%), or severe (Hb up to 10%) anaemia during antennal visit. They had significantly lower median (range) levels of haemoglobin 96 (40-110) g/L, ferritin 8 (3-54) nu mu/L, folate 15 (3-54) mu mol/L and cobalamin 171 (111-629) mu mol/L than controls (p=<0.01). Micro nutrient analysis revealed secondary pregnancy related deficiency of Iron (57%), folate (20%), combined iron and folate (19%) and cobalamin (4%) in the female. Among the risk factors, low income (OR: 7.69), multi party (OR: 2.93), lack of iron/folate supplementation (OR 2.91) and inadequate dietary intakes (OR 2.51) were associated with anaemia. Conclusion: The pregnant anaemic women had iron (57%); folate (20%), followed by combined iron folate (19%), and cobalamin (4%) deficiency during first antenatal visit. Low income, multi party, poor diet and lack of supplements are the main contributor in development of anaemia during pregnancy. (author)

  2. Iron, folate and cobalamin deficiency in anaemic pregnant females in tertiary care centre at Rawalpindi

    International Nuclear Information System (INIS)

    Khan, D.A.; Fatima, S.; Imran, R.; Khan, F.A.

    2010-01-01

    Background: Anaemia in pregnancy is a common clinical problem contributing to increased maternal and foetal morbidity. This study was carried out to determine frequency of iron, folate and cobalamin deficiency and associated risk factors in the anaemic pregnant females who reported first time during second and third trimester for antenatal check-up in the tertiary care hospital at Rawalpindi. Methods: This case control study was carried out in a tertiary care hospital at Rawalpindi. Two hundred and fifty pregnant women (age: 19-43 years) consisting of 125 anaemic (Hb< 110 g/L) and 125 non-anaemic who reported first time at antenatal clinic were included. Data on socio-demographic characteristics, parity and dietary intake were collected. Complete blood counts were done. Serum ferritin, folate and cobalamin assays were performed by using DPC kits on Immulite-1000. Results: The pregnant women were categorised having mild (Hb up to 54%), moderate (Hb up to 36%), or severe (Hb up to 10%) anaemia during antennal visit. They had significantly lower median (range) levels of haemoglobin 96 (40-110) g/L, ferritin 8 (3-54) nu mu/L, folate 15 (3-54) mu mol/L and cobalamin 171 (111-629) mu mol/L than controls (p=<0.01). Micro nutrient analysis revealed secondary pregnancy related deficiency of Iron (57%), folate (20%), combined iron and folate (19%) and cobalamin (4%) in the female. Among the risk factors, low income (OR: 7.69), multi party (OR: 2.93), lack of iron/folate supplementation (OR 2.91) and inadequate dietary intakes (OR 2.51) were associated with anaemia. Conclusion: The pregnant anaemic women had iron (57%); folate (20%), followed by combined iron folate (19%), and cobalamin (4%) deficiency during first antenatal visit. Low income, multi party, poor diet and lack of supplements are the main contributor in development of anaemia during pregnancy. (author)

  3. Nutritional Intake and Status of Cobalamin and Folate among Non-Pregnant Women of Reproductive Age in Bhaktapur, Nepal

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    Ram K. Chandyo

    2016-06-01

    Full Text Available Cobalamin and folate are especially important for women of childbearing age due to their ubiquitous role in fetal growth and development. Population-based data on cobalamin and folate status are lacking from Nepal, where diets are mostly vegetarian. The objectives of the study were to investigate cobalamin and folate intake and status, and to explore associations with socio-demographics, anthropometrics, anemia, and dietary habits. Following a random selection of geographical clusters, we collected blood samples from 500 non-pregnant women and 24-h dietary recalls and food frequency questionnaires from a subsample of 379 women. Twenty percent of the women did not consume any food containing cobalamin during the days recalled, and in 72% nutritional cobalamin intake was <1 μg/day. Eighty-four percent of the women had cobalamin intake lower than the estimated average requirement (EAR (<2 μg/day. In contrast, only 12% of the women had a folate intake less than 100 μg per day, whereas 62% had intake between 100 and 320 μg. Low plasma cobalamin (<150 pmol/L was found in 42% of the women, most of whom (88% also had elevated levels of methylmalonic acid. Our results indicated a high prevalence of nutritional cobalamin deficiency, while folate deficiency was uncommon.

  4. Homocysteine, Cobalamin and Folate Status and their Relations to Neurocognitive and Psychological Markers in Elderly in Northeasten of Iran.

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    Manavifar, Lida; Nemati Karimooy, Habibollah; Jamali, Jamshid; Talebi Doluee, Morteza; Shirdel, Abbas; Nejat Shokohi, Amireh; Fatemi Nayyeri, Mahdie

    2013-06-01

    Incidence of neurocognitive and psychological disorders may be related to serum homocystein (Hcy), cobalamin (vitamin B12) and folate levels in old people. The aim of this study was to assess the relation between Hcy, cobalamin, folate and neurocognitive and/or psychological disorders in the elderly. In this cross-sectional study, 280 subjects with ≥ 65 years old ,were evaluated. The subjects were selected from 12 regions of Mashhad, Iran, over March to October 2009. After blood sampling, data were collected by questionnaire, face to face interview and performing neurocognitive and psychological tests. The sera of 250 persons were analyzed for cobalamin and folate by RIA method. Amongst the aforementioned samples, 78 cases with cobalamin <300 pg/ml and folate <6.5 ng/ml were analyzed for Hcy by ELISA method. Amongst the people, 126 (45%) were male and 154 (55%) were female. The prevalence of hyperhomocysteinemia (HHcy) was 59.5% and 37.1% in male and female respectively (P -value =0.049). Hcy inversely correlated to cobalamin (r=-0.282, P=0.014) and to folate (r=-0.203, P=0.014). Hcy, cobalamin and folate correlations to neurocognitive and psychological impairments were not statically significant. Hyper Hcy or low cobalamin and folate in the elderly, are prevalent but their relationships with neurocognitive and psychological impairments is controversial. If these relationships had been confirmed, performing a single serum Hcy or cobalamin test would have been enough enough to diagnose and prevent neurocognitive impairments and inversely, neurocognitive-psychological sign and symptoms could have meant probable tissue vitamin deficiencies. However methods of assessing neurocognitive and psychological markers with validity and reliability of clinical and laboratory tests for finding aforementioned relationships should be revised.

  5. The effect of the oxidation state of the folate standard on the results of the simultaneous radioassay of serum folate and cobalamin

    International Nuclear Information System (INIS)

    Lindemans, J.; Kapel, J. van

    1981-01-01

    The authors have compared a commercial radioisotope dilution assay using pteroylglutamic acid as a standard and a non-commercial assay using L-methyl-tetrahydrofolate as a standard. The iodinated tracer folate was the same in both methods. Both assays measure folate and colabamin simultaneously, which gave the opportunity to discuss also the results of the cobalamin assay. (Auth.)

  6. Homocysteine, Cobalamin and Folate Status and their Relations to Neurocognitive and Psychological Markers in Elderly in Northeastern of Iran

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    Lida Manavifar

    2013-06-01

    Full Text Available       Objective(s: Incidence of neurocognitive and psychological disorders may be related to serum homocystein (Hcy, cobalamin (vitamin B12 and folate levels in old people. The aim of this study was to assess the relation between Hcy, cobalamin, folate and neurocognitive and/or psychological disorders in the elderly.   Materials and Methods: In this cross-sectional study, 280 subjects with ≥ 65 years old, were evaluated. The subjects were selected from 12 regions of Mashhad, Iran, over March to October 2009. After blood sampling, data were collected by questionnaire, face to face interview and performing neurocognitive and psychological tests. The sera of 250 persons were analyzed for cobalamin and folate by RIA method. Amongst the aforementioned samples, 78 cases with cobalamin Results: Amongst the people, 126 (45% were male and 154 (55% were female. The prevalence of hyperhomocysteinemia (HHcy was 59.5% and 37.1% in male and female respectively (P -value =0.049. Hcy inversely correlated to cobalamin (r=-0.282, P=0.014 and to folate (r=-0.203, P=0.014. Hcy, cobalamin and folate correlations to neurocognitive and psychological impairments were not statically significant. Conclusion: Hyper Hcy or low cobalamin and folate in the elderly, are prevalent but their relationships with neurocognitive and psychological impairments is controversial. If these relationships had been confirmed, performing a single serum Hcy or cobalamin test would have been enough to diagnose and prevent neurocognitive impairments and inversely, neurocognitive-psychological sign and symptoms could have meant probable tissue vitamin deficiencies. However methods of assessing neurocognitive and psychological markers with validity and reliability of clinical and laboratory tests for finding aforementioned relationships should be revised.  

  7. Cobalamin and folate status predicts mental development scores in North Indian children 12-18 mo of age.

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    Strand, Tor A; Taneja, Sunita; Ueland, Per M; Refsum, Helga; Bahl, Rajiv; Schneede, Joern; Sommerfelt, Halvor; Bhandari, Nita

    2013-02-01

    Micronutrient deficiencies can affect cognitive function. Many young children in low- and middle-income countries have inadequate cobalamin (vitamin B-12) status. The objective was to measure the association of plasma concentrations of folate, cobalamin, total homocysteine, and methylmalonic acid with cognitive performance at 2 occasions, 4 mo apart, in North Indian children aged 12-18 mo. Bayley Scales of Infant Development II were used to assess cognition. In multiple regression models adjusted for several potential confounders, we measured the association between biomarkers for folate and cobalamin status and psychomotor or mental development scores on the day of blood sampling and 4 mo thereafter. Each 2-fold increment in plasma cobalamin concentration was associated with a significant increment in the mental development index score of 1.3 (95% CI: 0.2, 2.4; P = 0.021). Furthermore, each 2-fold increment in homocysteine or methylmalonic acid concentration was associated with a decrement in mental development index score of 2.0 (95% CI: 0.5, 3.4; P = 0.007) or 1.1 (95% CI: 0.3, 1.8; P = 0.004) points, respectively. Plasma folate concentration was significantly and independently associated with mental development index scores only when children with poor cobalamin status were excluded, ie, in those who had cobalamin concentrations below the 25th percentile. None of these markers was associated with psychomotor scores in the multiple regression models. Cobalamin and folate status showed a statistically significant association with cognitive performance. Given the high prevalence of deficiencies in these nutrients, folate and cobalamin supplementation trials are required to measure any beneficial effect on cognition.

  8. Cobalamin inactivation by nitrous oxide produces severe neurological impairment in fruit bats: protection by methionine and aggravation by folates

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    van der Westhuyzen, J.; Fernandes-Costa, F.; Metz, J.

    1982-11-01

    Nitrous oxide, which inactivates cobalamin when administered to fruit bats, results in severe neurological impairment leading to ataxia, paralysis and death. This occurs after about 6 weeks in animals depleted of cobalamin by dietary restriction, and after about 10 weeks in cobalamin replete bats. Supplementation of the diet with pteroylglutamic acid caused acceleration of the neurological impairment--the first unequivocal demonstration of aggravation of the neurological lesion in cobalamin deficiency by pteroylglutamic acid. The administration of formyltetrahydropteroylglutamic acid produced similar aggravation of the neurological lesion. Supplementation of the diet with methionine protected the bats from neurological impairment, but failed to prevent death. Methionine supplementation protected against the exacerbating effect of folate, preventing the development of neurological changes. These findings lend support to the hypothesis that the neurological lesion in cobalamin deficiency may be related to a deficiency in the methyl donor S-adenosylmethionine which follows diminished synthesis of methionine.

  9. METHYLMALONIC ACID AND HOMOCYSTEIN SERUM IN DIAGNOSING MEGALOBLASTIC ANEMIA DUE TO COBALAMIN AND FOLATE DEFICIENCY IN TRAVEL MEDICINE

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    Made Gian Indra Rahayuda

    2014-01-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE Anemia is a major global health problem, especially in developing countries. Anemia is a condition where the red blood cell mass and / or hemoglobin mass that circulating in the body was decreased to below normal level so it can not function well in providing oxygen to the body tissues. One of the most common type is megaloblastic anemia. Megaloblastic anemia is mostly caused by vitamin B12 (cobalamin and folate deficiency. One of the causes of cobalamin and folate deficiency anemia is tropical sprue. Cobalamin deficiency anemia and folate deficiency anemia gives a similar symptom, but in cobalamin deficiency there is neuropathy symptoms. Normal serum folate is between 3-15 ng/mL. Normal folate erythrocyte is 150-600 ng/mL. In cobalamin deficiency, serum cobalamin decreased below the cut off point 100pg/mL (normally 100 - 400pg/mL. Other examination such as elevated homocysteine??, methylmalonic acid, or formioglutamic acid (FIGLU in the urine can confirm the diagnosis of cobalamin and folic acid deficiency. There is no consensus on the cut-off point of homocysteine ??and MMA. Homocysteine ??has been considered to increase when the levels are above 12-14 ?mol /L in women and in the 14-15 ?mol/L. According to research by Robert et al in the case of cobalamin deficiency, serum tHcy> 15.0 ?mol/L. Most research considers the increase of MMA in cobalamin deficiency is> 0:28 ?mol / L, but the cut off point in circulation varies between 0:21 to 0:48 ?mol/L. MMA level is increased in serum and urine in cobalamin deficiency, whereas MMA normal in folate deficiency. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font

  10. Vitamin-responsive disorders: cobalamin, folate, biotin, vitamins B1 and E.

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    Baumgartner, Matthias R

    2013-01-01

    The catalytic properties of many enzymes depend on the participation of vitamins as obligatory cofactors. Vitamin B12 (cobalamin) and folic acid (folate) deficiencies in infants and children classically present with megaloblastic anemia and are often accompanied by neurological signs. A number of rare inborn errors of cobalamin and folate absorption, transport, cellular uptake, and intracellular metabolism have been delineated and identification of disease-causing mutations has improved our ability to diagnose and treat many of these conditions. Two inherited defects in biotin metabolism are known, holocarboxylase synthetase and biotinidase deficiency. Both lead to multiple carboxylase deficiency manifesting with metabolic acidosis, neurological abnormalities, and skin rash. Thiamine-responsive megaloblastic anemia is characterized by megaloblastic anemia, non-type I diabetes, and sensorineural deafness that responds to pharmacological doses of thiamine (vitamin B1). Individuals affected with inherited vitamin E deficiencies including ataxia with isolated vitamin E deficiency and abetalipoproteinemia present with a spinocerebellar syndrome similar to patients with Friedreich's ataxia. If started early, treatment of these defects by oral or parenteral administration of the relevant vitamin often results in correction of the metabolic defect and reversal of the signs of disease, stressing the importance of early and correct diagnosis in these treatable conditions. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. The biomarker-based validity of a food frequency questionnaire to assess the intake status of folate, pyridoxine and cobalamin among Iranian primary breast cancer patients.

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    Pirouzpanah, S; Taleban, F-A; Mehdipour, P; Atri, M; Hooshyareh-rad, A; Sabour, S

    2014-03-01

    Folate, pyridoxine and cobalamin are coenzymatically essential in one-carbon methyl metabolism, and their deficiencies could explain some alterations during breast carcinogenesis. We aimed to evaluate the validity of folate, pyridoxine and cobalamin estimates from a food frequency questionnaire (FFQ) on the basis of their corresponding fasting plasma biomarkers, in breast cancer (BC) patients. In a prospective, consecutive case series, 149 women with primary BC aged between 30 and 69 years as a representative sample of Iranian women with BC were recruited. The 136-item FFQ was used for the validity assay. Fasting plasma folate and cobalamin were tested by automated electrochemiluminescence. The high-pressure liquid chromatography with fluorescence detection was used to determine the plasma levels of pyridoxal-5'-phosphate (PLP) and total homocysteine (tHcy). Area under the curve (AUC) for assessing the diagnostic accuracy of folate-related data through an FFQ was 0.74 (Pfasting plasma concentrations. Our data supported the validity of new FFQ to rank individuals by dietary intake status of folate and cobalamin.

  12. The Effects of Methionine-Enriched and Vitamins (Folate, Pyridoxine and Cobalamine-Deficient Diet on Exploratory Activity in Rats - A Brief Report

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    Mijailovic Natasa

    2017-12-01

    Full Text Available The aim of this study was to evaluate the impact of increased homocysteine levels induced by methionine nutritional overload (twice as standard and deficiency of the vitamins folate, pyridoxine and cobalamine, which plays an important role in homocysteine metabolism in anxiety-related behaviour, expressed by means of exploratory activity in rats. Twenty-three male Wistar albino rats (4 weeks old, 100±15 g body weight were divided into three groups: control (n=8, methionine-enriched (Meth+, 7.7 g of methionine/kg chow, n=7 and methionine-enriched vitamin-deficient (Meth+Vit-, 7.7 g of methionine/ kg chow, deficient in folate, pyridoxine and cobalamine - 0.08, 0.01 and 0.01 mg/kg, n=8. All animals had free access to food and water for 30 days. Behavioural testing was performed using the elevated plus maze (EPM test. Standard parameters for vertical exploratory activity, the number of rearings and the number of head-dippings, as well as the total exploratory activity (summarizing overall exploratory activity in the EPM were significantly reduced following 30 days of methionine nutritional overload (p<0.05, p<0.05 and p<0.01, respectively. A methionine-enriched diet coupled with a reduction in some B vitamins resulted in a more pronounced decline in exploratory drive observed in the EPM test compared to the control (p<0.01. The decline in total exploratory activity associated with vitamin deficiency was significant compared to the Meth+ group (p<0.05. The results of this study highlight the important role of homocysteine in the modulation of exploratory activity in rats. Decreased exploratory drive induced by both a methionine-enriched and vitamin-deficient diet could be attributed to an anxiogenic effect of hyperhomocysteinemia.

  13. Pyridoxal-5'-phosphate deficiency is associated with hyperhomocysteinemia regardless of antioxidant, thiamine, riboflavin, cobalamine, and folate status in critically ill patients.

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    Molina-López, Jorge; Florea, Daniela; Quintero-Osso, Bartolomé; de la Cruz, Antonio Pérez; Rodríguez-Elvira, Manuel; Del Pozo, Elena Planells

    2016-06-01

    was only associated with hyperhomocysteinemia regardless of antioxidant, riboflavin, cobalamine, and folate statuses in critically ill patients with SIRS at seventh day of ICU stay. PLP deficient patients presented about six times more risk of cardiovascular disease than non deficients. Copyright © 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  14. Correlation of Tc-99 m ethyl cysteinate dimer single-photon emission computed tomography and clinical presentations in patients with low cobalamin status.

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    Tu, Min-Chien; Lo, Chung-Ping; Chen, Ching-Yuan; Huang, Ching-Feng

    2015-12-03

    Cobalamin (Cbl) deficiency has been associated with various neuropsychiatric symptoms of different severities. While some studies dedicated in structural neuroimaging credibly address negative impact of low Cbl status, functional imaging reports are limited. We herein retrospectively review the correlation of Tc-99 m ethyl cysteinate dimer single-photon emission computed tomography (Tc-99 m-ECD SPECT) and clinical presentations among patients with low serum cobalamin (Cbl) status (Tc-99 m-ECD SPECT, and neuropsychological tests were reviewed. Dysexecutive syndrome (67 %), forgetfulness (50 %), attention deficits (42 %), and sleep disorders (33 %) constituted the major clinical presentations. All patients (100 %) had temporal hypoperfusion on the Tc-99 m-ECD SPECT. Five patients (42 %) had hypoperfusion restricted within temporal regions and deep nuclei; seven patients (58 %) had additional frontal hypoperfusion. In patients with hypoperfusion restricted within temporal regions and deep nuclei, psychiatric symptoms with spared cognition were their main presentations. Among patients with additional frontal hypoperfusion, six of seven patients (86 %) showed impaired cognitive performances (two of them were diagnosed as having dementia). Among ten patients who finished neuropsychological tests, abstract thinking (70 %) was the most commonly affected, followed by verbal fluency (60 %), short-term memory (50 %), and attention (50 %). Anxiety and sleep problems were the major clinically remarkable psychiatric features (33 % both). Four Tc-99 m-ECD SPECT follow-up studies were available; the degree and extent of signal reversal correlated with cognitive changes after Cbl replacement therapy. Our TC-99 m-ECD SPECT observations provide pivotal information of neurobiological changes within basal ganglia and fronto-temporal regions in conjunction with disease severity among patients with Cbl deficiency. Hypoperfusion within thalamus/basal ganglia and temporal regions may be

  15. Folate, homocysteine, and cobalamin status in patients with rheumatoid arthritis treated with methotrexate, and the effect of low dose folic acid supplement

    DEFF Research Database (Denmark)

    Hornung, Nete; Ellingsen, Torkell; Stengaard-Pedersen, Kristian

    2004-01-01

    OBJECTIVE: To investigate the effect of methotrexate (MTX) treatment of rheumatoid arthritis (RA) on folate metabolism, and to determine the effect of low dose folic acid on toxicity, efficacy, and folate status. METHODS: A 52-week prospective study of 81 patients with RA treated with MTX and self...

  16. The association of gastric cancer risk with plasma folate, cobalamin, and Methylenetetrahydrofolate reductase polymorphisms in the European prospective investigation into cancer and nutrition

    NARCIS (Netherlands)

    Vollset, Stein Emil; Igland, Jannicke; Jenab, Mazda; Fredriksen, Ase; Meyer, Klaus; Eussen, Simone; Gjessing, Hakon K.; Ueland, Per Magne; Pera, Guillem; Sala, Nuria; Agudo, Antonio; Capella, Gabriel; Del Giudice, Giuseppe; Palli, Domenico; Boeing, Heiner; Weikert, Cornelia; Bueno-de-Mesquita, H. Bas; Carneiro, Fatima; Pala, Valeria; Vineis, Paolo; Tumino, Rosario; Panico, Salvatore; Berglund, Goran; Manjer, Jonas; Stenling, Roger; Hallmans, Goran; Martinez, Carmen; Dorronsoro, Miren; Barricarte, Aurelio; Navarro, Carmen; Quiros, Jose R.; Allen, Naomi; Key, Timothy J.; Bingham, Sheila; Linseisen, Jakob; Kaaks, Rudolf; Overvad, Kim; Tjonneland, Anne; Buchner, Frederike L.; Peeters, Petra H. M.; Numans, Mattijs E.; Clavel-Chapelon, Francoise; Boutron-Ruault, Marie-Christine; Trichopoulou, Antonia; Lund, Eiliv; Slimani, Nadia; Ferrari, Pietro; Riboli, Elio; Gonzalez, Carlos A.

    Previous studies have shown inconsistent associations of folate intake and polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene with gastric cancer risk. Our nested case-control study within the European Prospective Investigation into Cancer and Nutrition cohort is the first

  17. The association of gastric cancer risk with plasma folate, cobalamin, and methylenetetrahydrofolate reductase polymorphisms in the European Prospective Investigation into Cancer and Nutrition.

    NARCIS (Netherlands)

    Vollset, S.E.; Igland, J.; Jenab, M.; Fredriksen, A.; Meyer, K.; Eussen, S.; Gjessing, H.K.; Ueland, P.M.; Pera, G.; Sala, N.; Agudo, A.; Capella, G.; Giudice, G. Del; Palli, D.; Boeing, H.; Weikert, C.; Bueno-De-Mesquita, H.B.; Carneiro, F.; Pala, V.; Vineis, P.; Tumino, R.; Panico, S.; Berglund, G.; Manjer, J.; Stenling, R.; Hallmans, G.; Martinez, C.; Dorronsoro, M.; Barricarte, A.; Navarro, C; Quiros, J.R.; Allen, N.; Key, T.J.; Bingham, S.; Linseisen, J.; Kaaks, R.; Overvad, K.; Tjonneland, A.; Buchner, F.L.; Peeters, P.H.; Numans, M.E.; Clavel-Chapelon, F.; Boutron-Ruault, M.C.; Trichopoulou, A.; Lund, E.; Slimani, N.; Ferrari, P.; Riboli, E.; Gonzalez, C.A.

    2007-01-01

    Previous studies have shown inconsistent associations of folate intake and polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene with gastric cancer risk. Our nested case-control study within the European Prospective Investigation into Cancer and Nutrition cohort is the first

  18. Cobalamin-Independent Methionine Synthase (MetE): A Face-to-Face Double Barrel that Evolved by Gene Duplication

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    Pejcha, Robert; Ludwig, Martha L. (Michigan)

    2010-03-08

    Cobalamin-independent methionine synthase (MetE) catalyzes the transfer of a methyl group from methyltetrahydrofolate to L-homocysteine (Hcy) without using an intermediate methyl carrier. Although MetE displays no detectable sequence homology with cobalamin-dependent methionine synthase (MetH), both enzymes require zinc for activation and binding of Hcy. Crystallographic analyses of MetE from T. maritima reveal an unusual dual-barrel structure in which the active site lies between the tops of the two ({beta}{alpha}){sub 8} barrels. The fold of the N-terminal barrel confirms that it has evolved from the C-terminal polypeptide by gene duplication; comparisons of the barrels provide an intriguing example of homologous domain evolution in which binding sites are obliterated. The C-terminal barrel incorporates the zinc ion that binds and activates Hcy. The zinc-binding site in MetE is distinguished from the (Cys){sub 3}Zn site in the related enzymes, MetH and betaine-homocysteine methyltransferase, by its position in the barrel and by the metal ligands, which are histidine, cysteine, glutamate, and cysteine in the resting form of MetE. Hcy associates at the face of the metal opposite glutamate, which moves away from the zinc in the binary E {center_dot} Hcy complex. The folate substrate is not intimately associated with the N-terminal barrel; instead, elements from both barrels contribute binding determinants in a binary complex in which the folate substrate is incorrectly oriented for methyl transfer. Atypical locations of the Hcy and folate sites in the C-terminal barrel presumably permit direct interaction of the substrates in a ternary complex. Structures of the binary substrate complexes imply that rearrangement of folate, perhaps accompanied by domain rearrangement, must occur before formation of a ternary complex that is competent for methyl transfer.

  19. Cobalamin-Independent Methionine Synthase (MetE): A Face-to-Face Double Barrel that Evolved by Gene Duplication

    International Nuclear Information System (INIS)

    Pejcha, Robert; Ludwig, Martha L.

    2005-01-01

    Cobalamin-independent methionine synthase (MetE) catalyzes the transfer of a methyl group from methyltetrahydrofolate to L-homocysteine (Hcy) without using an intermediate methyl carrier. Although MetE displays no detectable sequence homology with cobalamin-dependent methionine synthase (MetH), both enzymes require zinc for activation and binding of Hcy. Crystallographic analyses of MetE from T. maritima reveal an unusual dual-barrel structure in which the active site lies between the tops of the two (βα) 8 barrels. The fold of the N-terminal barrel confirms that it has evolved from the C-terminal polypeptide by gene duplication; comparisons of the barrels provide an intriguing example of homologous domain evolution in which binding sites are obliterated. The C-terminal barrel incorporates the zinc ion that binds and activates Hcy. The zinc-binding site in MetE is distinguished from the (Cys) 3 Zn site in the related enzymes, MetH and betaine-homocysteine methyltransferase, by its position in the barrel and by the metal ligands, which are histidine, cysteine, glutamate, and cysteine in the resting form of MetE. Hcy associates at the face of the metal opposite glutamate, which moves away from the zinc in the binary E · Hcy complex. The folate substrate is not intimately associated with the N-terminal barrel; instead, elements from both barrels contribute binding determinants in a binary complex in which the folate substrate is incorrectly oriented for methyl transfer. Atypical locations of the Hcy and folate sites in the C-terminal barrel presumably permit direct interaction of the substrates in a ternary complex. Structures of the binary substrate complexes imply that rearrangement of folate, perhaps accompanied by domain rearrangement, must occur before formation of a ternary complex that is competent for methyl transfer.

  20. Cobalamin-independent methionine synthase (MetE: a face-to-face double barrel that evolved by gene duplication.

    Directory of Open Access Journals (Sweden)

    Robert Pejchal

    2005-02-01

    Full Text Available Cobalamin-independent methionine synthase (MetE catalyzes the transfer of a methyl group from methyltetrahydrofolate to L-homocysteine (Hcy without using an intermediate methyl carrier. Although MetE displays no detectable sequence homology with cobalamin-dependent methionine synthase (MetH, both enzymes require zinc for activation and binding of Hcy. Crystallographic analyses of MetE from T. maritima reveal an unusual dual-barrel structure in which the active site lies between the tops of the two (betaalpha(8 barrels. The fold of the N-terminal barrel confirms that it has evolved from the C-terminal polypeptide by gene duplication; comparisons of the barrels provide an intriguing example of homologous domain evolution in which binding sites are obliterated. The C-terminal barrel incorporates the zinc ion that binds and activates Hcy. The zinc-binding site in MetE is distinguished from the (Cys(3Zn site in the related enzymes, MetH and betaine-homocysteine methyltransferase, by its position in the barrel and by the metal ligands, which are histidine, cysteine, glutamate, and cysteine in the resting form of MetE. Hcy associates at the face of the metal opposite glutamate, which moves away from the zinc in the binary E.Hcy complex. The folate substrate is not intimately associated with the N-terminal barrel; instead, elements from both barrels contribute binding determinants in a binary complex in which the folate substrate is incorrectly oriented for methyl transfer. Atypical locations of the Hcy and folate sites in the C-terminal barrel presumably permit direct interaction of the substrates in a ternary complex. Structures of the binary substrate complexes imply that rearrangement of folate, perhaps accompanied by domain rearrangement, must occur before formation of a ternary complex that is competent for methyl transfer.

  1. Cobalamin analogues in humans

    DEFF Research Database (Denmark)

    Hardlei, Tore Forsingdal; Obeid, Rima; Herrmann, Wolfgang

    2013-01-01

    BACKGROUND: Haptocorrin (HC) carries cobalamin analogues (CorA), but whether CorA are produced in the body is unknown. All cobalamins (Cbl) to the foetus are delivered by the Cbl-specific protein transcobalamin (TC), and therefore analysis of cord serum for CorA may help to clarify the origin...

  2. A U-shaped relationship between plasma folate and pancreatic cancer risk in the European Prospective Investigation into Cancer and Nutrition

    NARCIS (Netherlands)

    Chuang, Shu-Chun; Stolzenberg-Solomon, Rachael; Ueland, Per Magne; Vollset, Stein Emil; Midttun, Oivind; Olsen, Anja; Tjonneland, Anne; Overvad, Kim; Boutron-Ruault, Marie-Christine; Morois, Sophie; Clavel-Chapelon, Francoise; Teucher, Birgit; Kaaks, Rudolf; Weikert, Cornelia; Boeing, Heiner; Trichopoulou, Antonia; Benetou, Vassiliki; Naska, Androniki; Jenab, Mazda; Slimani, Nadia; Romieu, Isabelle; Michaud, Dominique S.; Palli, Domenico; Sieri, Sabina; Panico, Salvatore; Sacerdote, Carlotta; Tumino, Rosario; Skeie, Guri; Duell, Eric J.; Rodriguez, Laudina; Molina-Montes, Esther; Maria Huerta, Jose; Larranaga, Nerea; Barricarte Gurrea, Aurelio; Johansen, Dorthe; Manjer, Jonas; Ye, Weimin; Sund, Malin; Peeters, Petra H. M.; Jeurnink, Suzanne; Wareham, Nicholas; Khaw, Kay-Tee; Crowe, Francesca; Riboli, Elio; Bueno-de-Mesquita, Bas; Vineis, Paolo

    Folate intake has shown an inverse association with pancreatic cancer; nevertheless, results from plasma measurements were inconsistent. The aim of this study is to examine the association between plasma total homocysteine, methionine, folate, cobalamin, pyridoxal 5'-phosphate, riboflavin, flavin

  3. Unexpected high plasma cobalamin

    DEFF Research Database (Denmark)

    Arendt, Johan F B; Nexo, Ebba

    2013-01-01

    It is well-established that more than 8% of patients examined for vitamin B12 deficiency unexpectedly have increased plasma levels of the vitamin, but so far there are no guidelines for the clinical interpretation of such findings. In this review, we summarise known associations between high plasma...... cobalamin binding proteins, transcobalamin and haptocorrin. Based on current knowledge, we suggest a strategy for the clinical interpretation of unexpected high plasma cobalamin. Since a number of the associated diseases are critical and life-threatening, the strategy promotes the concept of 'think...

  4. Folate bioavailability

    OpenAIRE

    Öhrvik, Veronica

    2009-01-01

    An inadequate folate status is associated with increased risk of anaemia and neural tube defects. In many countries a folate intake below recommendations has been reported for women in childbearing age. However, data on folate intake and status are not always associated, since factors other than intake, e.g. bioavailability, affect folate status. This thesis studied the bioavailability of folate using in vivo and in vitro models. The effect of two pieces of Swedish nutritional advice on folat...

  5. Cobalamin and haptocorrin in human milk and cobalamin-related variables in mother and child

    DEFF Research Database (Denmark)

    Greibe, Eva; Lildballe, Dorte L; við Streym, Susanna

    2013-01-01

    BACKGROUND: Measurement of milk cobalamin is hampered by the high content of the cobalamin-binding protein haptocorrin, and limited data are available relating trustworthy measures of milk cobalamin to cobalamin status in healthy mothers and their children. OBJECTIVES: The objectives were to expl...

  6. Free and protein-bound cobalamin absorption in healthy middle-aged and older subjects.

    Science.gov (United States)

    van Asselt, D Z; van den Broek, W J; Lamers, C B; Corstens, F H; Hoefnagels, W H

    1996-08-01

    To study free- and protein-bound cobalamin absorption and the correlation with atrophic gastritis in healthy middle-aged and older subjects. A cross-sectional study. Fifty-two healthy subjects, aged 26 to 87 years, apparently free from conditions known to influence the cobalamin status. Middle-aged subjects were defined as those younger than 65 years of age (median age 57 years) and older subjects as those 65 years and older (median age 75 years). Protein-bound cobalamin absorption was assessed by 48-hour urinary excretion method following oral administration of scrambled egg yolk, labeled in vivo with 57 Co-cobalamin by injecting a hen with 57 Co-cyanocobalamin. The percentage of 57 Co-cobalamin bound to protein was 65%. Free cobalamin absorption was assessed by 48-hour urinary excretion method following oral administration of crystalline 57 Co-cyanocobalamin. Plasma cobalamin, folate and fasting plasma gastrin, and pepsinogen A and C concentrations were determined. The median urinary excretion of egg yolk 57 Co-cobalamin in middle-aged subjects was 12.3% (25th and 75th percentiles 10.5%-14.5%) compared with 11.7% (25th and 75th percentiles 9.8%-13.6%) in older subjects (P = .283). The median urinary excretion after administration of free 57 Co-cobalamin in middle-aged subjects was 25.7% (25th and 75th percentiles 20.6%-30.7%) compared with 27.9% (25th and 75th percentiles 21.4%-34.5%) in older subjects (P = .694). Neither egg yolk nor free 57 Co-cobalamin excretion correlated with age. A ratio of pepsinogen A to pepsinogen C less than 1.6, indicating atrophic gastritis, was found in 13 subjects. Within the atrophic gastritis group, 11 subjects had a pepsinogen A concentration greater than or equal to 17 micrograms/L, indicating mild to moderate atrophic gastritis, and two subjects had a pepsinogen A concentration less than 17 micrograms/L, indicating severe atrophic gastritis or gastric atrophy. All subjects had normal fasting plasma gastrin concentrations. Free

  7. Homocyst(e)ine metabolism in hemodialysis patients treated with vitamins B6, B12 and folate.

    Science.gov (United States)

    Henning, B F; Zidek, W; Riezler, R; Graefe, U; Tepel, M

    2001-03-01

    Hyperhomocyst(e)inemia is commonly accepted as an independent atherosclerotic risk factor. In most hemodialysis patients, serum homocyst(e)ine is markedly elevated and may contribute to premature atherosclerosis in these patients. Whereas the beneficial effect of folate supplementation on serum homocyst(e)ine has been extensively studied, there are less detailed studies on the effects of cobalamin and pyridoxal phosphate alone, or in combination with folate. We examined the effect of a four-week course of intravenous treatment with folate (1.1 mg), cobalamin (1.0 mg), and pyridoxal phosphate (5.0 mg), administered once (group 1), twice (group 2) or thrice (group 3) weekly in 33 hemodialysis patients divided in three groups of 11 patients. All patients were followed for a further four weeks after treatment was stopped. Serum homocyst(e)ine, cobalamin, folate and pyridoxal phosphate, as well as the metabolites of homocyst(e)ine, methylmalonate, 2-methylcitrate and cystathionine, were determined before, during and after treatment. Baseline serum homocyst(e)ine correlated significantly with serum folate (P=0.0149), cobalamin (P=0.0047) and pyridoxal phosphate (P=0.0408). Correlations independent from the other metabolites or vitamins were found for methylmalonate (P=0.003) and folate (P=0.029). All regimens increased serum cobalamin significantly (in group 1 from 444 +/- 215 to 17,303 +/- 11,989 pg/ml, Pine was lowered significantly by 39.8% +/- 31.9% (Pine levels. Increasing cobalamin levels and additional treatment with folate and pyridoxal phosphate 156 may decrease serum homocyst(e)ine in the same way as high doses of folate alone.

  8. Alternatively Spliced Methionine Synthase in SH-SY5Y Neuroblastoma Cells: Cobalamin and GSH Dependence and Inhibitory Effects of Neurotoxic Metals and Thimerosal

    Directory of Open Access Journals (Sweden)

    Mostafa Waly

    2016-01-01

    Full Text Available The folate and cobalamin (Cbl- dependent enzyme methionine synthase (MS is highly sensitive to oxidation and its activity affects all methylation reactions. Recent studies have revealed alternative splicing of MS mRNA in human brain and patient-derived fibroblasts. Here we show that MS mRNA in SH-SY5Y human neuroblastoma cells is alternatively spliced, resulting in three primary protein species, thus providing a useful model to examine cofactor dependence of these variant enzymes. MS activity was dependent upon methylcobalamin (MeCbl or the combination of hydroxocobalamin (OHCbl and S-adenosylmethionine (SAM. OHCbl-based activity was eliminated by depletion of the antioxidant glutathione (GSH but could be rescued by provision of either glutathionylcobalamin (GSCbl or MeCbl. Pretreatment of cells with lead, arsenic, aluminum, mercury, or the ethylmercury-containing preservative thimerosal lowered GSH levels and inhibited MS activity in association with decreased uptake of cysteine, which is rate-limiting for GSH synthesis. Thimerosal treatment decreased cellular levels of GSCbl and MeCbl. These findings indicate that the alternatively spliced form of MS expressed in SH-SY5Y human neuronal cells is sensitive to inhibition by thimerosal and neurotoxic metals, and lower GSH levels contribute to their inhibitory action.

  9. A disulfide-stabilized conformer of methionine synthase reveals an unexpected role for the histidine ligand of the cobalamin cofactor

    Energy Technology Data Exchange (ETDEWEB)

    Datta, Supratim; Koutmos, Markos; Pattridge, Katherine A.; Ludwig, Martha L.; Matthews, Rowena G. (Michigan)

    2008-07-08

    B{sub 12}-dependent methionine synthase (MetH) from Escherichia coli is a large modular protein that is alternately methylated by methyltetrahydrofolate to form methylcobalamin and demethylated by homocysteine to form cob(I)alamin. Major domain rearrangements are required to allow cobalamin to react with three different substrates: homocysteine, methyltetrahydrofolate, and S-adenosyl-l-methionine (AdoMet). These same rearrangements appear to preclude crystallization of the wild-type enzyme. Disulfide cross-linking was used to lock a C-terminal fragment of the enzyme into a unique conformation. Cysteine point mutations were introduced at Ile-690 and Gly-743. These cysteine residues span the cap and the cobalamin-binding module and form a cross-link that reduces the conformational space accessed by the enzyme, facilitating protein crystallization. Here, we describe an x-ray structure of the mutant fragment in the reactivation conformation; this conformation enables the transfer of a methyl group from AdoMet to the cobalamin cofactor. In the structure, the axial ligand to the cobalamin, His-759, dissociates from the cobalamin and forms intermodular contacts with residues in the AdoMet-binding module. This unanticipated intermodular interaction is expected to play a major role in controlling the distribution of conformers required for the catalytic and the reactivation cycles of the enzyme.

  10. Cobalamin Deficiency in Elderly Patients: A Personal View

    Directory of Open Access Journals (Sweden)

    Emmanuel Andrès

    2008-01-01

    Full Text Available Cobalamin (vitamin B12 deficiency is particularly common in the elderly (>65 years of age but is often unrecognized because its clinical manifestations are subtle; however, they are also potentially serious, particularly from a neuropsychiatric and hematological perspective. In the elderly, the main causes of cobalamin deficiency are pernicious anemia and food-cobalamin malabsorption. Food-cobalamin malabsorption syndrome is a disorder characterized by the inability to release cobalamin from food or its binding proteins. This syndrome is usually caused by atrophic gastritis, related or unrelated to Helicobacter pylori infection, and long-term ingestion of antacids and biguanides. Management of cobalamin deficiency with cobalamin injections is currently well documented but new routes of cobalamin administration (oral and nasal are being studied, especially oral cobalamin therapy for food-cobalamin malabsorption.

  11. Cobalamin Deficiency Results in Increased Production of Formate Secondary to Decreased Mitochondrial Oxidation of One-Carbon Units in Rats.

    Science.gov (United States)

    MacMillan, Luke; Tingley, Garrett; Young, Sara K; Clow, Kathy A; Randell, Edward W; Brosnan, Margaret E; Brosnan, John T

    2018-03-01

    Formate is produced in mitochondria via the catabolism of serine, glycine, dimethylglycine, and sarcosine. Formate produced by mitochondria may be incorporated into the cytosolic folate pool where it can be used for important biosynthetic reactions. Previous studies from our lab have shown that cobalamin deficiency results in increased plasma formate concentrations. Our goal was to determine the basis for elevated formate in vitamin B-12 deficiency. Male Sprague Dawley rats were randomly assigned to consume either a cobalamin-replete (50 μg cobalamin/kg diet) or -deficient (no added cobalamin) diet for 6 wk. Formate production was measured in vivo and in isolated liver mitochondria from a variety of one-carbon precursors. We also measured the oxidation of [3-14C]-l-serine to 14CO2 in isolated rat liver mitochondria and the expression of hepatic genes involved in one-carbon unit and formate metabolism. Cobalamin-deficient rats produce formate at a rate 55% higher than that of replete rats. Formate production from serine was increased by 60% and from dimethylglycine and sarcosine by ∼200% in liver mitochondria isolated from cobalamin-deficient rats compared with cobalamin-replete rats. There was a 26% decrease in the 14CO2 produced by mitochondria from cobalamin-deficient rats. Gene expression analysis showed that 10-formyltetrahydrofolate dehydrogenase-cytosolic (Aldh1l1) and mitochondrial (Aldh1l2) expression were decreased by 40% and 60%, respectively, compared to control, while 10-formyltetrahydrofolate synthetase, mitochondrial, monofunctional (Mthfd1l) expression was unchanged. We propose that a bifurcation in mitochondrial one-carbon metabolism is a key control mechanism in determining the fate of one-carbon units, to formate or CO2. During cobalamin deficiency in rats the disposition of 10-formyl-tetrahydrofolate carbon is shifted in favor of formate production. This may represent a mechanism to generate more one-carbon units for the replenishment of the S

  12. Folate absorption

    International Nuclear Information System (INIS)

    Baker, S.J.

    1976-01-01

    Folate is the generic term given to numerous compounds of pteroic acid with glutamic acid. Knowledge of absorption is limited because of the complexities introduced by the variety of compounds and because of the inadequacy of investigational methods. Two assay methods are in use, namely microbiological and radioactive. Techniques used to study absorption include measurement of urinary excretion, serum concentration, faecal excretion, intestinal perfusion, and haematological response. It is probably necessary to test absorption of both pteroylmonoglutamic acid and one or more polyglutamates, and such tests would be facilitated by availability of synthesized compounds labelled with radioactive tracers at specifically selected sites. (author)

  13. Cobalamin and its binding protein in rat milk

    DEFF Research Database (Denmark)

    Raaberg, Lasse; Nexø, Ebba; Poulsen, Steen Seier

    1989-01-01

    Cobalamin and its binding protein, haptocorrin, are present in rat milk throughout the lactation period. The concentration of cobalamin is approximately 0.3-times the concentration of the unsaturated binding protein. The concentration of the unsaturated cobalamin-binding protein varies between 18...

  14. Metformin Lowers Serum Cobalamin without Changing Other Markers of Cobalamin Status: A Study on Women with Polycystic Ovary Syndrome

    DEFF Research Database (Denmark)

    Greibe, Eva; Trolle, G. Birgitta; Bor, Mustafa Vakur

    2013-01-01

    Treatment with the anti-diabetic drug metformin is followed by a decline in plasma cobalamin, but it is unsettled whether this denotes an impaired cobalamin status. This study has explored changes in the markers of cobalamin status in women with Polycystic Ovary Syndrome treated with metformin (1...

  15. Cobalamin deficiency, hyperhomocysteinemia, and dementia

    Directory of Open Access Journals (Sweden)

    Steven F Werder

    2010-04-01

    Full Text Available Steven F Werder1,21Kansas University School of Medicine – Wichita, Wichita, KS, USA; 2Community Health Center of Southeast Kansas, Pittsburg, KS, USAIntroduction: Although consensus guidelines recommend checking serum B12 in patients with dementia, clinicians are often faced with various questions: (1 Which patients should be tested? (2 What test should be ordered? (3 How are inferences made from such testing? (4 In addition to serum B12, should other tests be ordered? (5 Is B12 deficiency compatible with dementia of the Alzheimer’s type? (6 What is to be expected from treatment? (7 How is B12 deficiency treated?Methods: On January 31st, 2009, a Medline search was performed revealing 1,627 citations related to cobalamin deficiency, hyperhomocysteinemia, and dementia. After limiting the search terms, all abstracts and/or articles and other references were categorized into six major groups (general, biochemistry, manifestations, associations and risks, evaluation, and treatment and then reviewed in answering the above questions.Results: The six major groups above are described in detail. Seventy-five key studies, series, and clinical trials were identified. Evidence-based suggestions for patient management were developed.Discussion: Evidence is convincing that hyperhomocysteinemia, with or without hypovitaminosis B12, is a risk factor for dementia. In the absence of hyperhomocysteinemia, evidence is less convincing that hypovitaminosis B12 is a risk factor for dementia. B12 deficiency manifestations are variable and include abnormal psychiatric, neurological, gastrointestinal, and hematological findings. Radiological images of individuals with hyperhomocysteinemia frequently demonstrate leukoaraiosis. Assessing serum B12 and treatment of B12 deficiency is crucial for those cases in which pernicious anemia is suspected and may be useful for mild cognitive impairment and mild to moderate dementia. The serum B12 level is the standard initial test

  16. Metformin Lowers Serum Cobalamin without Changing Other Markers of Cobalamin Status: A Study on Women with Polycystic Ovary Syndrome

    Directory of Open Access Journals (Sweden)

    Ebba Nexo

    2013-07-01

    Full Text Available Treatment with the anti-diabetic drug metformin is followed by a decline in plasma cobalamin, but it is unsettled whether this denotes an impaired cobalamin status. This study has explored changes in the markers of cobalamin status in women with Polycystic Ovary Syndrome treated with metformin (1.5–2.5 g per day (n = 29 or placebo (n = 23 for six months. Serum samples were collected before and after two, four, and six months of treatment. We found serum cobalamin to decline and reach significant lower levels after six months of treatment (p = 0.003. Despite the decline in serum cobalamin, we observed no reductions in the physiological active part of cobalamin bound to transcobalamin (holotranscobalamin, or increase in the metabolic marker of cobalamin status, methylmalonic acid. Instead, the non-functional part of circulating cobalamin bound to haptocorrin declined (p = 0.0009. Our results have two implications: The data questions whether metformin treatment induces an impaired cobalamin status in PCOS patients, and further suggests that serum cobalamin is a futile marker for judging cobalamin status in metformin-treated patients.

  17. Naturally occurring cobalamins have antimalarial activity.

    Science.gov (United States)

    Chemaly, Susan M; Chen, Chien-Teng; van Zyl, Robyn L

    2007-05-01

    The acquisition of resistance by malaria parasites towards existing antimalarials has necessitated the development of new chemotherapeutic agents. The effect of vitamin B(12) derivatives on the formation of beta-haematin (synthetic haemozoin) was determined under conditions similar to those in the parasitic food vacuole (using chloroquine, a known inhibitor of haemozoin formation for comparison). Adenosylcobalamin (Ado-cbl), methylcobalamin (CH(3)-cbl) and aquocobalamin (H(2)O-cbl) were approximately forty times more effective inhibitors of beta-haematin formation than chloroquine, cyanocobalamin (CN-cbl) was slightly more inhibitory than chloroquine, while dicyanocobinamide had no effect. It is proposed that the cobalamins exert their inhibitory effect on beta-haematin formation by pi-interactions of their corrin ring with the Fe(III)-protoporphyrin ring and by hydrogen-bonding using their 5,6-dimethylbenzimidazole/ribose/sugar side-chain. The antimalarial activity for the cobalamins (Ado-cbl>CH(3)-cbl>H(2)O-cbl>CN-cbl) was found to be less than that for chloroquine or quinine. Ado-cbl, CH(3)-cbl and CN-cbl do not accumulate in the parasite food vacuole by pH trapping, but H(2)O-cbl does. Unlike humans, the malaria parasite has only one enzyme that uses cobalamin as a cofactor, namely methionine synthase, which is important for growth and metabolism. Thus cobalamins in very small amounts are necessary for Plasmodium falciparum growth but in larger amounts they display antimalarial properties.

  18. Oral cobalamin supplementation in cats with hypocobalaminaemia: a retrospective study.

    Science.gov (United States)

    Toresson, Linda; Steiner, Joerg M; Olmedal, Gunilla; Larsen, MajBritt; Suchodolski, Jan S; Spillmann, Thomas

    2017-12-01

    Objectives The objective of the study was to evaluate whether oral cobalamin supplementation can restore normocobal-aminaemia in cats with hypocobalaminaemia and clinical signs of gastrointestinal disease. Methods This was a retrospective study based on a computerised database search for client-owned cats treated at Evidensia Specialist Animal Hospital, Helsingborg, Sweden, during the period December 2013 to August 2016. Inclusion criteria were cats with clinical signs of chronic enteropathy, an initial serum cobalamin concentration ⩽250 pmol/l (reference interval 214-738 pmol/l) and oral treatment with cobalamin tablets. Results Twenty-five cats met the inclusion criteria. The cats were treated with 0.25 mg cyanocobalamin tablets once daily. Serum cobalamin concentration was rechecked 27-94 days after continuous oral cobalamin supplementation. All cats had serum cobalamin concentrations above the reference interval after oral cobalamin supplementation. Median (range) serum cobalamin concentration was 128 pmol/l (111-250 pmol/l) prior to treatment and 2701 pmol/l (738-16,359 pmol/l) after supplementation. This difference was statistically significant ( P cats with hypocobalaminaemia. Thus, oral cobalamin supplementation is a promising alternative to parenteral administration. Prospective comparative studies in cats being treated with parenteral vs oral cobalamin supplementation in a larger number of patients are warranted before oral supplementation can be recommended for routine use.

  19. Radioassay of folates

    International Nuclear Information System (INIS)

    Givas, J.K.; Gutcho, S.

    1976-01-01

    In the radioassay of folates, the standard is prepared by using folic acid (pteroyl glutamic acid; PGA) as the standard folate at a pH of 9.2 to 9.4. At such pH values, folic acid and 5-methyltetrahydrofolic acid (the predominant folate in human serum) have essentially identical reactivity towards folate binders, whereby folic acid can replace unstable 5-methyltetrahydrofolic acid standard for such assays

  20. The Cobalamin-binding Protein in Zebrafish is an Intermediate Between the Three Cobalamin-binding Proteins in Human

    DEFF Research Database (Denmark)

    Greibe, Eva Holm; Fedosov, Sergey; Nexø, Ebba

    2012-01-01

    are the oldest evolutionary derivatives followed by IF and HC (the latter being present only in reptiles and most but not all mammals). Our findings suggest that the only cobalamin-binding protein in zebrafish is an intermediate between the three human cobalamin binders. These findings support the hypothesis...

  1. 89Zr-Cobalamin PET Tracer

    DEFF Research Database (Denmark)

    Kuda-Wedagedara, Akhila N W; Workinger, Jayme L; Nexo, Ebba

    2017-01-01

    Vitamin B12, or cobalamin (Cbl), is an essential nutrient. Acquisition, transport, and cellular internalization of Cbl are dependent on specific binding proteins and associated receptors. The circulating transport protein transcobalamin (TC) promotes cellular uptake via binding to specific......-Cbl (CN-Cbl). In vitro studies employing the CD320 receptor-positive breast cancer cell line MDA-MB-453 showed a 6- to 10-fold greater uptake of 89Zr-Cbl when compared with the uptake in the presence of 200-fold excess of CN-Cbl at 37 °C. We used nude mice with MDA-MB-453 tumors to study the feasibility...

  2. Cobalamins uncovered by modern electronic structure calculations

    DEFF Research Database (Denmark)

    Kepp, Kasper Planeta; Ryde, Ulf

    2009-01-01

    electronic-structure calculations, in particular density functional methods, the understanding of the molecular mechanism of cobalamins has changed dramatically, going from a dominating view of trans-steric strain effects to a much more complex view involving an arsenal of catalytic strategies. Among...... these are cis-steric distortions, electrostatic stabilization of radical products, the realization that nucleotide units can serve as polar handles, and the careful design of the active sites, with polar residues in the radical enzymes and non-polar residues in the transferases. Together, these strategies...

  3. Human Folate Bioavailability

    OpenAIRE

    Ohrvik, Veronica E.; Witthoft, Cornelia M.

    2011-01-01

    The vitamin folate is recognized as beneficial health-wise in the prevention of neural tube defects, anemia, cardiovascular diseases, poor cognitive performance, and some forms of cancer. However, suboptimal dietary folate intake has been reported in a number of countries. Several national health authorities have therefore introduced mandatory food fortification with synthetic folic acid, which is considered a convenient fortificant, being cost-efficient in production, more stable than natura...

  4. Clinical aspects of cobalamin deficiency in elderly patients. Epidemiology, causes, clinical manifestations, and treatment with special focus on oral cobalamin therapy.

    Science.gov (United States)

    Andrès, Emmanuel; Vidal-Alaball, Josep; Federici, Laure; Loukili, Noureddine Henoun; Zimmer, Jacques; Kaltenbach, Georges

    2007-10-01

    The aim of this work was to review the literature concerning cobalamin deficiency in elderly patients. Articles were identified through searches of PubMed-MEDLINE (January 1990 to June 2006), restricted to: English and French language, human subjects, elderly patients (>65 years), clinical trial, review and guidelines. Additional unpublished data from our cohort with cobalamin deficiency at the University Hospital of Strasbourg, France, were also considered. All of the papers and abstracts were reviewed by at least two senior researchers who selected the data used in the study. In elderly people, the main causes of cobalamin deficiency are pernicious anemia and food-cobalamin malabsorption. The recently identified food-cobalamin malabsorption syndrome is a disorder characterized by the inability to release cobalamin from food or from its binding proteins. This syndrome is usually the consequence of atrophic gastritis, related or not to Helicobacter pylori infection, and of the long-term ingestion of antacids and biguanides (in around 60% of the patients). Management of cobalamin deficiency has been well established with the use of cobalamin injections. However, new routes of cobalamin administration (oral and nasal) are currently being developed, especially the use of oral cobalamin therapy to treat food-cobalamin malabsorption.

  5. Enzymatic extraction of cobalamin from monoclonal antibody captured haptocorrin and transcobalamin

    DEFF Research Database (Denmark)

    Hardlei, Tore Forsingdal; Mørkbak, Anne Louise; Nexo, Ebba

    2007-01-01

    OBJECTIVES: Current extraction methods for cobalamins from serum influence the molecular characteristics of the vitamin. Therefore, an extraction procedure that leaves the cobalamins unchanged is needed. DESIGN AND METHODS: Monoclonal antibodies towards transcobalamin (TC) and haptocorrin (HC) (in...

  6. Cobalamin Deficiency: Clinical Picture and Radiological Findings

    Directory of Open Access Journals (Sweden)

    Chiara Briani

    2013-11-01

    Full Text Available Vitamin B12 deficiency causes a wide range of hematological, gastrointestinal, psychiatric and neurological disorders. Hematological presentation of cobalamin deficiency ranges from the incidental increase of mean corpuscular volume and neutrophil hypersegmentation to symptoms due to severe anemia, such as angor, dyspnea on exertion, fatigue or symptoms related to congestive heart failure, such as ankle edema, orthopnea and nocturia. Neuropsychiatric symptoms may precede hematologic signs and are represented by myelopathy, neuropathy, dementia and, less often, optic nerve atrophy. The spinal cord manifestation, subacute combined degeneration (SCD, is characterized by symmetric dysesthesia, disturbance of position sense and spastic paraparesis or tetraparesis. The most consistent MRI finding is a symmetrical abnormally increased T2 signal intensity confined to posterior or posterior and lateral columns in the cervical and thoracic spinal cord. Isolated peripheral neuropathy is less frequent, but likely overlooked. Vitamin B12 deficiency has been correlated negatively with cognitive functioning in healthy elderly subjects. Symptoms include slow mentation, memory impairment, attention deficits and dementia. Optic neuropathy occurs occasionally in adult patient. It is characterized by symmetric, painless and progressive visual loss. Parenteral replacement therapy should be started soon after the vitamin deficiency has been established.

  7. A Single Rainbow Trout Cobalamin-binding Protein Stands in for Three Human Binders

    DEFF Research Database (Denmark)

    Greibe, Eva Holm; Fedosov, Sergey; Sorensen, Boe S

    2012-01-01

    affinity for the cobalamin analog cobinamide. Like haptocorrin and transcobalamin, the trout cobalamin-binding protein was present in plasma and recognized ligands with altered nucleotide moiety. Like intrinsic factors, the trout cobalamin-binding protein was present in the stomach and resisted degradation...... by trypsin and chymotrypsin. It also resembled intrinsic factor in the composition of conserved residues in the primary cobalamin-binding site in the C terminus. The trout cobalamin-binding protein was glycosylated and displayed spectral properties comparable with those of haptocorrin and intrinsic factor...

  8. Folate and human reproduction.

    Science.gov (United States)

    Tamura, Tsunenobu; Picciano, Mary Frances

    2006-05-01

    The influence of folate nutritional status on various pregnancy outcomes has long been recognized. Studies conducted in the 1950s and 1960s led to the recognition of prenatal folic acid supplementation as a means to prevent pregnancy-induced megaloblastic anemia. In the 1990s, the utility of periconceptional folic acid supplementation and folic acid food fortification emerged when they were proven to prevent the occurrence of neural tube defects. These distinctively different uses of folic acid may well be ranked among the most significant public health measures for the prevention of pregnancy-related disorders. Folate is now viewed not only as a nutrient needed to prevent megaloblastic anemia in pregnancy but also as a vitamin essential for reproductive health. This review focuses on the relation between various outcomes of human reproduction (ie, pregnancy, lactation, and male reproduction) and folate nutrition and metabolism, homocysteine metabolism, and polymorphisms of genes that encode folate-related enzymes or proteins, and we identify issues for future research.

  9. Cobalamin C deficiency in an adolescent with altered mental status and anorexia.

    Science.gov (United States)

    Rahmandar, Maria H; Bawcom, Amanda; Romano, Mary E; Hamid, Rizwan

    2014-12-01

    Although cobalamin (cbl) C deficiency is the most common inherited disorder of vitamin B12 metabolism, the late-onset form of the disease can be difficult to recognize because it has a broad phenotypic spectrum. In this report, we describe an adolescent female exposed to unknown illicit substances and sexual abuse who presented with psychosis, anorexia, seizures, and ataxia. The patient's diagnosis was delayed until a metabolic workup was initiated, revealing hyperhomocysteinemia, low normal plasma methionine, and methylmalonic aciduria. Ultimately, cblC deficiency was confirmed when molecular testing showed compound heterozygosity for mutations (c.271dupA and c.482G>A) in the MMACHC gene. This diagnosis led to appropriate treatment with hydroxocobalamin, betaine, and folate, which resulted in improvement of her clinical symptoms and laboratory values. This patient demonstrates a previously unrecognized presentation of late-onset cblC deficiency. Although neuropsychiatric symptoms are common in late-onset disease, seizures and cerebellar involvement are not. Furthermore, anorexia has not been previously described in these patients. This case emphasizes that inborn errors of metabolism should be part of the differential diagnosis for a teenager presenting with altered mental status, especially when the diagnosis is challenging or neurologic symptoms are unexplained. Correct diagnosis of this condition is important because treatment is available and can result in clinical improvement.(1.) Copyright © 2014 by the American Academy of Pediatrics.

  10. Folate Production by Probiotic Bacteria

    Directory of Open Access Journals (Sweden)

    Stefano Raimondi

    2011-01-01

    Full Text Available Probiotic bacteria, mostly belonging to the genera Lactobacillus and Bifidobacterium, confer a number of health benefits to the host, including vitamin production. With the aim to produce folate-enriched fermented products and/or develop probiotic supplements that accomplish folate biosynthesis in vivo within the colon, bifidobacteria and lactobacilli have been extensively studied for their capability to produce this vitamin. On the basis of physiological studies and genome analysis, wild-type lactobacilli cannot synthesize folate, generally require it for growth, and provide a negative contribution to folate levels in fermented dairy products. Lactobacillus plantarum constitutes an exception among lactobacilli, since it is capable of folate production in presence of para-aminobenzoic acid (pABA and deserves to be used in animal trials to validate its ability to produce the vitamin in vivo. On the other hand, several folate-producing strains have been selected within the genus Bifidobacterium, with a great variability in the extent of vitamin released in the medium. Most of them belong to the species B. adolescentis and B. pseudocatenulatum, but few folate producing strains are found in the other species as well. Rats fed a probiotic formulation of folate-producing bifidobacteria exhibited increased plasma folate level, confirming that the vitamin is produced in vivo and absorbed. In a human trial, the same supplement raised folate concentration in feces. The use of folate-producing probiotic strains can be regarded as a new perspective in the specific use of probiotics. They could more efficiently confer protection against inflammation and cancer, both exerting the beneficial effects of probiotics and preventing the folate deficiency that is associated with premalignant changes in the colonic epithelia.

  11. Validation of Folate-Enriched Eggs as a Functional Food for Improving Folate Intake in Consumers

    OpenAIRE

    Altic, Leslie; McNulty, Helene; Hoey, Leane; McAnena, Liadhan; Pentieva, Kristina

    2016-01-01

    Functional foods enriched with folate may be beneficial as a means of optimizing folate status in consumers. We recently developed novel eggs enriched with folate through folic acid supplementation of the hen’s feed, but their potential to influence consumer folate status is unknown because the natural folate forms incorporated into the eggs may not necessarily be retained during storage and cooking. This study aimed to determine the stability of natural folates in folate-enriched eggs under ...

  12. Successful intrauterine treatment of a patient with cobalamin C defect

    Directory of Open Access Journals (Sweden)

    Friedrich K. Trefz

    2016-03-01

    Full Text Available Cobalamin C (cblC defect is an inherited autosomal recessive disorder that affects cobalamin metabolism. Patients are treated with hydroxycobalamin to ameliorate the clinical features of early-onset disease and prevent clinical symptoms in late-onset disease. Here we describe a patient in whom prenatal maternal treatment with 30 mg/week hydroxycobalamin and 5 mg/day folic acid from week 15 of pregnancy prevented disease manifestation in a girl who is now 11 years old with normal IQ and only mild ophthalmic findings. The affected older sister received postnatal treatment only and is severely intellectually disabled with severe ophthalmic symptoms. This case highlights the potential of early, high-dose intrauterine treatment in a fetus affected by the cblC defect.

  13. 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.

  14. Characterization and immunohistochemical localization of rat salivary cobalamin-binding protein and comparison with human salivary haptocorrin

    DEFF Research Database (Denmark)

    Nexø, Ebba; Poulsen, Steen Seier

    1985-01-01

    Rat saliva contains a cobalamin-binding protein that binds cobalamin as well as cobinamide. The protein binds cobalamin with an affinity constant of 8 X 10(10) l X mol-1, and it binds cobalamin over a more narrow pH range (pH 7.5-10) than does human haptocorrin. It has a Stokes radius of 2.45 nm...

  15. Influence of duration and dose of metformin on cobalamin deficiency in type 2 diabetes patients using metformin

    NARCIS (Netherlands)

    Beulens, Joline W J; Hart, Huberta E.; Kuijs, Ron; Kooijman-Buiting, Antoinette M J; Rutten, Guy E H M

    2015-01-01

    Metformin use is associated with cobalamin (vitamin B12) deficiency. However, the influence of both duration and dose of metformin is unclear. Studies using holotranscobalamin, a marker for cellular cobalamin deficiency, are scarce. We therefore investigated the prevalence of cobalamin deficiency in

  16. Relationship between cobalamin deficiency and delirium in elderly patients undergoing cardiac surgery

    Directory of Open Access Journals (Sweden)

    Sevuk U

    2015-08-01

    Full Text Available Utkan Sevuk,1 Erkan Baysal,2 Nurettin Ay,3 Yakup Altas,2 Rojhat Altindag,2 Baris Yaylak,2 Vahhac Alp,3 Ertan Demirtas4 1Department of Cardiovascular Surgery, Diyarbakir Gazi Yasargil Education and Research Hospital, Diyarbakir, 2Department of Cardiology, Diyarbakir Gazi Yasargil Education and Research Hospital, Diyarbakir, 3Department of General Surgery, Diyarbakir Gazi Yasargil Education and Research Hospital, Diyarbakir, 4Department of Cardiovascular Surgery, Liv Hospital, Ankara, Turkey Background: Delirium is common after cardiac surgery and is independently associated with increased morbidity, mortality, prolonged hospital stays, and higher costs. Cobalamin (vitamin B12 deficiency is a common cause of neuropsychiatric symptoms and affects up to 40% of elderly people. The relationship between cobalamin deficiency and the occurrence of delirium after cardiac surgery has not been examined in previous studies. We examined the relationship between cobalamin deficiency and delirium in elderly patients undergoing coronary artery bypass grafting (CABG surgery.Material and methods: A total of 100 patients with cobalamin deficiency undergoing CABG were enrolled in this retrospective study. Control group comprised 100 patients without cobalamin deficiency undergoing CABG. Patients aged 65 years or over were included. Diagnosis of delirium was made using Intensive Care Delirium Screening Checklist. Delirium severity was measured using the Delirium Rating Scale-revised-98.Results: Patients with cobalamin deficiency had a significantly higher incidence of delirium (42% vs 26%; P=0.017 and higher delirium severity scores (16.5±2.9 vs 15.03±2.48; P=0.034 than patients without cobalamin deficiency. Cobalamin levels were significantly lower in patients with delirium than patients without delirium (P=0.004. Delirium severity score showed a moderate correlation with cobalamin levels (Ρ=-0.27; P=0.024. Logistic regression analysis demonstrated that

  17. Insights into the reactivation of cobalamin-dependent methionine synthase

    Energy Technology Data Exchange (ETDEWEB)

    Koutmos, Markos; Datta, Supratim; Pattridge, Katherine A.; Smith, Janet L.; Matthews, Rowena G.; (Michigan)

    2009-12-10

    Cobalamin-dependent methionine synthase (MetH) is a modular protein that catalyzes the transfer of a methyl group from methyltetrahydrofolate to homocysteine to produce methionine and tetrahydrofolate. The cobalamin cofactor, which serves as both acceptor and donor of the methyl group, is oxidized once every {approx}2,000 catalytic cycles and must be reactivated by the uptake of an electron from reduced flavodoxin and a methyl group from S-adenosyl-L-methionine (AdoMet). Previous structures of a C-terminal fragment of MetH (MetH{sup CT}) revealed a reactivation conformation that juxtaposes the cobalamin- and AdoMet-binding domains. Here we describe 2 structures of a disulfide stabilized MetH{sup CT} ({sub s-s}MetH{sup CT}) that offer further insight into the reactivation of MetH. The structure of {sub s-s}MetH{sup CT} with cob(II)alamin and S-adenosyl-L-homocysteine represents the enzyme in the reactivation step preceding electron transfer from flavodoxin. The structure supports earlier suggestions that the enzyme acts to lower the reduction potential of the Co(II)/Co(I) couple by elongating the bond between the cobalt and its upper axial water ligand, effectively making the cobalt 4-coordinate, and illuminates the role of Tyr-1139 in the stabilization of this 4-coordinate state. The structure of {sub s-s}MetH{sub CT} with aquocobalamin may represent a transient state at the end of reactivation as the newly remethylated 5-coordinate methylcobalamin returns to the 6-coordinate state, triggering the rearrangement to a catalytic conformation.

  18. Effect of gastric anacidity on the intestinal absorption of liver bound 57Co-labelled cobalamins

    International Nuclear Information System (INIS)

    Kittang, E.

    1987-01-01

    57 Co-labelled cyanocobalamin injected in rabbit was transformed within the liver to 57 Co-labelled desoxyadenosylcobalamin and methylcovalamin. The absorption of 57 Co-labelled liver bound cobalamins could be determined with acceptable accuracy by the double isotope fecal excretion method. Treatment with the H 2-receptor antagonist, ranitidine, did not result in decreased absorption of 57 Co-labelled liver bound cobalamins in healthy individuals. R-protein and the R-proteincobalamin complex were determined by the FPLC Mono S chromatography method with a high degree of correlation to the charcoal method in saliva, gastric and duodenal juice, and with a high degree of reproducibility. Omeprazole markedly inhibited the gastric acid and pepsin secretion, but did nor inhibit the IF secretion. Omeprazole treatment resulted in anacidity in 14 of 17 individuals, but did not reduce the absorption of liver bound 57 Co-labelled cobalamins. The intrinsic factor concentration in gastric aspirates measured during the study was unchanged during omeprazole treatment. The release of cobalamins from liver homogenate was markedly inhibited by neutralized gastric juice in vitro, probably due to decreased pepsin mediated proteolysis. In vivo the cobalamin release from liver homogenate was modestly inhibited in the stomach but was unaffected in jejunum during omeprazole treatment. The major part of 57 Co-labelled liver cobalamins bound to R-protein in acid and neutral gastric juice in vitro, and omeprazole induced anacidity, did not influence the cobalamin binding either in gastric or jejunal juice in vivo

  19. Hyperammonaemic encephalopathy secondary to selective cobalamin deficiency in a juvenile Border collie.

    Science.gov (United States)

    Battersby, I A; Giger, U; Hall, E J

    2005-07-01

    An eight-month-old Border collie was presented with anorexia, cachexia, failure to thrive and stupor. Laboratory tests demonstrated a mild anaemia, neutropenia, proteinuria and hyperammonaemia. Serum bile acid concentrations were normal, but an ammonia tolerance test (ATT) was abnormal. The dog responded to symptomatic therapy for hepatoencephalopathy. When a low serum cobalamin (vitamin B12) concentration and methylmalonic aciduria were noted, the dog was given a supplement of parenteral cobalamin. Two weeks later, a repeat ATT was normal. Cobalamin supplementation was continued every two weeks, and all clinical signs, except for proteinuria, resolved despite withdrawing all therapy for hepatoencephalopathy. A presumptive diagnosis of hereditary selective cobalamin malabsorption was made, based on the young age, Border collie breed, low serum cobalamin concentration and methylmalonic aciduria. Although hereditary selective cobalamin malabsorption in Border collies, giant schnauzers, Australian shepherd dogs and beagles has previously been reported in North America, to the authors' knowledge this is the first report of the condition in the UK and the first to document an abnormal ATT in a cobalamin-deficient dog.

  20. Cobalamin deficiency associated with erythroblastic anemia and methylmalonic aciduria in a border collie.

    Science.gov (United States)

    Morgan, L W; McConnell, J

    1999-01-01

    Anemia due to cobalamin deficiency is a rare genetic disorder that has been recognized in dogs only recently. This report concerns a 14-month-old border collie that presented for chronic, nonregenerative anemia. Cytological examination of a peripheral blood smear showed the presence of erythroblasts. Serum cobalamin levels were below reference ranges reported for clinically normal dogs. A methylmalonic aciduria was found on urinalysis. These signs are consistent with the anemia in Imerslund-Graesbeck syndrome reported in humans. Anemia due to cobalamin deficiency responds to parenteral vitamin B12 therapy, and affected animals have a good prognosis for recovery.

  1. Oxidative stress inactivates cobalamin-independent methionine synthase (MetE in Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Elise R Hondorp

    2004-11-01

    Full Text Available In nature, Escherichia coli are exposed to harsh and non-ideal growth environments-nutrients may be limiting, and cells are often challenged by oxidative stress. For E. coli cells confronting these realities, there appears to be a link between oxidative stress, methionine availability, and the enzyme that catalyzes the final step of methionine biosynthesis, cobalamin-independent methionine synthase (MetE. We found that E. coli cells subjected to transient oxidative stress during growth in minimal medium develop a methionine auxotrophy, which can be traced to an effect on MetE. Further experiments demonstrated that the purified enzyme is inactivated by oxidized glutathione (GSSG at a rate that correlates with protein oxidation. The unique site of oxidation was identified by selectively cleaving N-terminally to each reduced cysteine and analyzing the results by liquid chromatography mass spectrometry. Stoichiometric glutathionylation of MetE by GSSG occurs at cysteine 645, which is strategically located at the entrance to the active site. Direct evidence of MetE oxidation in vivo was obtained from thiol-trapping experiments in two different E. coli strains that contain highly oxidizing cytoplasmic environments. Moreover, MetE is completely oxidized in wild-type E. coli treated with the thiol-oxidizing agent diamide; reduced enzyme reappears just prior to the cells resuming normal growth. We argue that for E. coli experiencing oxidizing conditions in minimal medium, MetE is readily inactivated, resulting in cellular methionine limitation. Glutathionylation of the protein provides a strategy to modulate in vivo activity of the enzyme while protecting the active site from further damage, in an easily reversible manner. While glutathionylation of proteins is a fairly common mode of redox regulation in eukaryotes, very few proteins in E. coli are known to be modified in this manner. Our results are complementary to the independent findings of Leichert

  2. The marker of cobalamin deficiency, plasma methylmalonic acid, correlates to plasma creatinine

    DEFF Research Database (Denmark)

    Hvas, A M; Juul, S; Gerdes, Lars Ulrik

    2000-01-01

    OBJECTIVE: To examine the relationship between the two diagnostic tests, plasma methylmalonic acid and plasma cobalamins, and their association with plasma creatinine, age and sex. DESIGN: Cross-sectional study of simultaneous laboratory measurements. SETTING: County of Aarhus, Denmark. SUBJECTS......: Records on 1689 patients who had their first plasma methylmalonic acid measurement during 1995 and 1996, and who had a simultaneous measurement of plasma cobalamins. Plasma creatinine values measured within a week of measurements of plasma methylmalonic acid and plasma cobalamins were available for 1255...... of the patients. MAIN OUTCOME MEASURES: Predictors of variation in plasma methylmalonic acid; plasma cobalamins, plasma creatinine, age and sex. RESULTS: Plasma methylmalonic acid was positively correlated with plasma creatinine, even for plasma creatinine within the normal range. These associations remained...

  3. Cobalamin status during normal pregnancy and postpartum: a longitudinal study comprising 406 danish women

    DEFF Research Database (Denmark)

    Milman, N; Byg, KE; Bergholt, T

    2006-01-01

    -) cobalamin, P-methylmalonic acid and P-homocysteine was measured at 18, 32 and 39 wk gestation and 8 wk postpartum during lactation. RESULTS: P-cobalamin showed a gradual, significant decline during pregnancy (P ... and 8 wk postpartum median values were 225, 172, 161 and 319 pmol/L, respectively. P-methylmalonic displayed a gradual, significant increase during pregnancy as well as postpartum (P homocysteine demonstrated...

  4. Transcellular transport of cobalamin in aortic endothelial cells.

    Science.gov (United States)

    Hannibal, Luciana; Bolisetty, Keerthana; Axhemi, Armend; DiBello, Patricia M; Quadros, Edward V; Fedosov, Sergey; Jacobsen, Donald W

    2018-05-09

    Cobalamin [Cbl (or B 12 )] deficiency causes megaloblastic anemia and a variety of neuropathies. However, homeostatic mechanisms of cyanocobalamin (CNCbl) and other Cbls by vascular endothelial cells are poorly understood. Herein, we describe our investigation into whether cultured bovine aortic endothelial cells (BAECs) perform transcytosis of B 12 , namely, the complex formed between serum transcobalamin and B 12 , designated as holo-transcobalamin (holo-TC). We show that cultured BAECs endocytose [ 57 Co]-CNCbl-TC (source material) via the CD320 receptor. The bound Cbl is transported across the cell both via exocytosis in its free form, [ 57 Co]-CNCbl, and via transcytosis as [ 57 Co]-CNCbl-TC. Transcellular mobilization of Cbl occurred in a bidirectional manner. A portion of the endocytosed [ 57 Co]-CNCbl was enzymatically processed by methylmalonic aciduria combined with homocystinuria type C (cblC) with subsequent formation of hydroxocobalamin, methylcobalamin, and adenosylcobalamin, which were also transported across the cell in a bidirectional manner. This demonstrates that transport mechanisms for Cbl in vascular endothelial cells do not discriminate between various β-axial ligands of the vitamin. Competition studies with apoprotein- and holo-TC and holo-intrinsic factor showed that only holo-TC was effective at inhibiting transcellular transport of Cbl. Incubation of BAECs with a blocking antibody against the extracellular domain of the CD320 receptor inhibited uptake and transcytosis by ∼40%. This study reveals that endothelial cells recycle uncommitted intracellular Cbl for downstream usage by other cell types and suggests that the endothelium is self-sufficient for the specific acquisition and subsequent distribution of circulating B 12 via the CD320 receptor. We posit that the endothelial lining of the vasculature is an essential component for the maintenance of serum-tissue homeostasis of B 12 .-Hannibal, L., Bolisetty, K., Axhemi, A., DiBello, P

  5. Growing Mouse Oocytes Transiently Activate Folate Transport via Folate Receptors As They Approach Full Size1

    OpenAIRE

    Meredith, Megan; MacNeil, Allison H.; Trasler, Jacquetta M.; Baltz, Jay M.

    2016-01-01

    The folate cycle is central to cellular one-carbon metabolism, where folates are carriers of one-carbon units that are critical for synthesis of purines, thymidylate, and S-adenosylmethionine, the universal methyl donor that forms the cellular methyl pool. Although folates are well-known to be important for early embryo and fetal development, their role in oogenesis has not been clearly established. Here, folate transport proteins were detected in developing neonatal ovaries and growing oocyt...

  6. Folate in Skin Cancer Prevention

    OpenAIRE

    Williams, J.D.; Jacobson, Elaine L.; Kim, H.; Kim, M.; Jacobson, M.K.

    2012-01-01

    Skin, the largest, most exposed organ of the body, provides a protective interface between humans and the environment. One of its primary roles is protection against exposure to sunlight, a major source of skin damage where the UV radiation (UVR) component functions as a complete carcinogen. Melanin pigmentation and the evolution of dark skin is an adaptive protective mechanism against high levels of UVR exposure. Recently, the hypothesis that skin pigmentation balances folate preservation an...

  7. Validation of Folate-Enriched Eggs as a Functional Food for Improving Folate Intake in Consumers.

    Science.gov (United States)

    Altic, Leslie; McNulty, Helene; Hoey, Leane; McAnena, Liadhan; Pentieva, Kristina

    2016-11-30

    Functional foods enriched with folate may be beneficial as a means of optimizing folate status in consumers. We recently developed novel eggs enriched with folate through folic acid supplementation of the hen's feed, but their potential to influence consumer folate status is unknown because the natural folate forms incorporated into the eggs may not necessarily be retained during storage and cooking. This study aimed to determine the stability of natural folates in folate-enriched eggs under typical conditions of storage and cooking. Total folate was determined by microbiological assay following tri-enzyme treatment in folate-enriched eggs and un-enriched (barn and free-range) on the day they were laid, after storage (up to 27 days) and after using four typical cooking methods (boiling, poaching, frying, scrambling) for different durations. On the day of laying, the folate content of enriched eggs was found to be significantly higher than that of un-enriched barn or free-range eggs (mean ± SD; 123.2 ± 12.4 vs. 41.2 ± 2.8 vs. 65.6 ± 18.5 µg/100 g; p functional foods with enriched folate content. Further studies will confirm their effectiveness in optimizing the biomarker folate status of consumers.

  8. Genetic Variation in Renal Expression of Folate Receptor 1 (Folr1) Gene Predisposes Spontaneously Hypertensive Rats to Metabolic Syndrome

    Czech Academy of Sciences Publication Activity Database

    Pravenec, Michal; Kožich, V.; Krijt, J.; Sokolová, J.; Zídek, Václav; Landa, Vladimír; Mlejnek, Petr; Šilhavý, Jan; Šimáková, Miroslava; Škop, V.; Trnovská, J.; Kazdová, L.; Kajiya, T.; Wang, J. M.; Kurtz, T. W.

    2016-01-01

    Roč. 67, č. 2 (2016), s. 335-341 ISSN 0194-911X R&D Projects: GA ČR GA14-09283S; GA MŠk(CZ) LH12061; GA MŠk(CZ) LL1204 Institutional support: RVO:67985823 Keywords : blood pressure * cysteine * folate receptor 1 * metabolic syndrome X * rats * inbred SHR Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 6.857, year: 2016

  9. 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)

  10. Synthesis and characterization of nido-carborane-cobalamin conjugates

    International Nuclear Information System (INIS)

    Hogenkamp, Harry P.C.; Collins, Douglas A.; Live, David; Benson, Linda M.; Naylor, Stephen

    2000-01-01

    Three vitamin B 12 (cyanocobalamin) conjugates bearing one nido-carborane molecule or two nido-carborane molecules linked to the propionamide side chains via a four carbon linker have been synthesized. Reaction of o-carboranoylchloride with 1,4-diaminobutane in pyridine produced nido-carboranoyl(4-amidobutyl)amine, which was linked to the b- and d-monocarboxylic acids and the b,d-dicarboxylic acid of cyanocobalamin. Mass spectrometry analysis as well as 11 B nuclear magnetic resonance demonstrated that during the reaction of o-carboranonylchloride with diaminobutane one of the boron atoms was eliminated. In vitro biological activity of the cyanocobalamin-nido-carborane conjugates was assessed by the unsaturated vitamin B 12 binding capacity assay. When compared with 57 Co cyanocobalamin, the biological activity of cyanocobalamin-b-nido-carborane, cyanocobalamin-d-nido-carborane, and cyanocobalamin-b-d-bis-nido-carborane conjugates were 92.93%, 35.75%, and 37.02%, respectively. These findings suggest that the 10 B cobalamin conjugates might be useful agents in treating malignant tumors via neutron capture therapy

  11. Increase in circulating holotranscobalamin after oral administration of cyanocobalamin or hydroxocobalamin in healthy adults with low and normal cobalamin status

    DEFF Research Database (Denmark)

    Greibe, Eva; Mahalle, Namita; Bhide, Vijayshri

    2017-01-01

    PURPOSE: To investigate the absorption of synthetic cyanocobalamin and natural occurring hydroxocobalamin in populations with low and normal cobalamin (vitamin B12) status. METHODS: We included adults with low (n = 59) and normal (n = 42) cobalamin status and measured the change in serum holotran...

  12. Growing Mouse Oocytes Transiently Activate Folate Transport via Folate Receptors As They Approach Full Size.

    Science.gov (United States)

    Meredith, Megan; MacNeil, Allison H; Trasler, Jacquetta M; Baltz, Jay M

    2016-06-01

    The folate cycle is central to cellular one-carbon metabolism, where folates are carriers of one-carbon units that are critical for synthesis of purines, thymidylate, and S-adenosylmethionine, the universal methyl donor that forms the cellular methyl pool. Although folates are well-known to be important for early embryo and fetal development, their role in oogenesis has not been clearly established. Here, folate transport proteins were detected in developing neonatal ovaries and growing oocytes by immunohistochemistry, Western blot, and immunofluorescence. The folate receptors FOLR1 and FOLR2 as well as reduced folate carrier 1 (RFC1, SLC19A1 protein) each appeared to be present in follicular cells including granulosa cells. In growing oocytes, however, only FOLR2 immunoreactivity appeared abundant. Localization of apparent FOLR2 immunofluorescence near the plasma membrane increased with oocyte growth and peaked in oocytes as they neared full size. We assessed folate transport using the model folate leucovorin (folinic acid). Unexpectedly, there was a transient burst of folate transport activity for a brief period during oocyte growth as they neared full size, while folate transport was otherwise undetectable for the rest of oogenesis and in fully grown germinal vesicle stage oocytes. This folate transport was inhibited by dynasore, an inhibitor of endocytosis, but insensitive to the anion transport inhibitor stilbene 4-acetamido-40-isothiocyanato-stilbene-2,20-disulfonic acid, consistent with folate receptor-mediated transport but not with RFC1-mediated transport. Thus, near the end of their growth, growing oocytes may take up folates that could support the final stage of oogenesis or be stored to provide the endogenous folates needed in early embryogenesis. © 2016 by the Society for the Study of Reproduction, Inc.

  13. Radioassay for serum and red cell folate

    International Nuclear Information System (INIS)

    Longo, D.L.; Herbert, V.

    1976-01-01

    A simple, reliable assay for serum and red cell folate is described. It uses plain untreated liquid or powdered milk, requiring no special handling or purification, as binder. Such milk makes it possible to ignore endogenous serum folate binder, since crude (but not purified) milk contains a factor which releases folate from serum binder. It simplifies counting radioactivity by employing a gamma emitting isotope of pteroylglutamic acid (PGA), namely the 125 I-tyramide of PGA. Like the 3 H-PGA assay of Givas and Gutcho, it permits the use of stable PGA rather than unstable methyltetrahydrofolic acid (MeTHFA) standards, because it is carried out at pH 9.3, a pH at which milk folate binder is unable to distinguish PGA from MeTHFA, which is the predominant folate in human tissues. The equipment required to do the radioassay is present in most diagnostic chemistry laboratories. Results are essentially identical to the generally accepted Lactobacillus casei microbiologic method of folate assay, except that false low results are not produced in the radioassay by antibiotics, tranquilizers, and chemotherapeutic agents. Three caveats in its use are the relative instability of 125 I-PGA as compared to 3 H-PGA, the fact that various powdered milks differ widely in folate-binding capacity, and that only about 60 percent of commercially obtained skim or powdered milk preparations appear to contain the substance which splits folate from serum binder

  14. EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2015. Scientific Opinion on Dietary Reference Values for cobalamin (vitamin B12)

    DEFF Research Database (Denmark)

    Tetens, Inge

    2015-01-01

    Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) derived Dietary Reference Values (DRVs) for cobalamin (vitamin B12). The Panel considers that the approach based on a combination of biomarkers of cobalamin status, i.e. serum....... For pregnancy and lactation, additional cobalamin intakes related to the accumulation of cobalamin in fetal tissues and transfer of cobalamin into breast milk are considered and AIs of 4.5 and 5 μg/day, respectively, are proposed....

  15. Validation of Folate-Enriched Eggs as a Functional Food for Improving Folate Intake in Consumers

    Directory of Open Access Journals (Sweden)

    Leslie Altic

    2016-11-01

    Full Text Available Functional foods enriched with folate may be beneficial as a means of optimizing folate status in consumers. We recently developed novel eggs enriched with folate through folic acid supplementation of the hen’s feed, but their potential to influence consumer folate status is unknown because the natural folate forms incorporated into the eggs may not necessarily be retained during storage and cooking. This study aimed to determine the stability of natural folates in folate-enriched eggs under typical conditions of storage and cooking. Total folate was determined by microbiological assay following tri-enzyme treatment in folate-enriched eggs and un-enriched (barn and free-range on the day they were laid, after storage (up to 27 days and after using four typical cooking methods (boiling, poaching, frying, scrambling for different durations. On the day of laying, the folate content of enriched eggs was found to be significantly higher than that of un-enriched barn or free-range eggs (mean ± SD; 123.2 ± 12.4 vs. 41.2 ± 2.8 vs. 65.6 ± 18.5 µg/100 g; p < 0.001. Storage at refrigerator and room temperature for periods up to the Best Before date resulted in no significant losses to the folate content of folate-enriched eggs. Furthermore, folate in enriched eggs remained stable when cooked by four typical methods for periods up to the maximum cooking time (e.g., 135 ± 22.5, 133.9 ± 23.0 and 132.5 ± 35.1; p = 0.73, for raw, scrambled for 50 s and scrambled for 2 min, respectively. Thus, natural folates in folate-enriched eggs remain highly stable with little or no losses following storage and cooking. These findings are important because they demonstrate the feasibility of introducing folate-enriched eggs into the diet of consumers as functional foods with enriched folate content. Further studies will confirm their effectiveness in optimizing the biomarker folate status of consumers.

  16. Folate content and availability in Malaysian cooked foods.

    Science.gov (United States)

    Chew, S C; Khor, G L; Loh, S P

    2012-12-01

    Data on folate availability of Malaysian cooked foods would be useful for estimation of dietary folate intake; however such information is scarce. A total of 53 samples of frequently consumed foods in Malaysia were selected from the Nutrient Composition of Malaysian Foods. Folate content was determined using HPLC method hyphenated with a stainless steel C18 column and ultraviolet detector (lambda = 280 nm). The index of folate availability was defined as the proportion of folate identified as monoglutamyl derivatives from the total folate content. Total folate content of different food samples varied from 30-95 microg/100g fresh weight. Among rice-based dishes, the highest and the lowest total folate was in coconut milk rice (nasi lemak) and ghee rice (nasi minyak), respectively. In noodle dishes, fried rice noodle (kuey teow goreng) and curry noodle (mee kari) had the highest folate contents. The highest index of folate availability was in a flat rice noodle dish (kuey teow bandung) (12.13%), while the lowest was in a festival cake (kuih bakul) (0.13%). Folate content was found to be negatively related to its availability. This study determined folate content and folate availability in commonly consumed cooked foods in Malaysia. The uptake of folate from foods with high folate content may not be necessarily high as folate absorption also depends on the capacity of intestinal deconjugation and the presence of high fibre in the foods.

  17. Systemic Scedosporium prolificans infection in an 11-month-old Border collie with cobalamin deficiency secondary to selective cobalamin malabsorption (canine Imerslund-Gräsbeck syndrome).

    Science.gov (United States)

    Erles, K; Mugford, A; Barfield, D; Leeb, T; Kook, P H

    2018-04-01

    An 11-month-old Border collie presented collapsed and continued to deteriorate rapidly despite supportive treatment. The dog had a history of failure to thrive and recurring respiratory infection. Laboratory abnormalities included neutrophilic leucocytosis, Heinz body anaemia, hyperammonaemia, hyperbilirubinaemia, proteinuria and hypocobalaminaemia. Post-mortem examination revealed multi-focal necrosis within the heart, kidneys, pancreas, liver, meninges and cerebral cortex. Fungal hyphae in lesions were identified as Scedosporium prolificans following culture. Subsequent genotyping confirmed that the dog carried the CUBN:c.8392delC mutation in a homozygous state, verifying hereditary cobalamin deficiency (a.k.a. Imerslund-Gräsbeck syndrome). Cobalamin deficiency may have been a predisposing factor for the development of systemic fungal infection in this dog. © 2017 British Small Animal Veterinary Association.

  18. Role of folate-homocysteine pathway gene polymorphisms and nutritional cofactors in Down syndrome: A triad study.

    Science.gov (United States)

    Sukla, K K; Jaiswal, S K; Rai, A K; Mishra, O P; Gupta, V; Kumar, A; Raman, R

    2015-08-01

    Do gene-gene and gene-environment interactions in folate-homocysteine (Hcy) pathway have a predisposing role for Down syndrome (DS)? The study provides evidence that in addition to advanced age, maternal genotype, micronutrient deficiency and elevated Hcy levels, individually and in combination, are risk factors for Down syndrome. Polymorphisms in certain folate-Hcy-pathway genes (especially the T allele of MTHFR C677T), elevated Hcy and poor folate levels in mothers during pregnancy have been shown to be risk factors for Down syndrome in certain Asian populations (including the eastern region of India), while the same SNPs are not a risk factor in European populations. This conflicting situation alludes to differential gene-environment (nutrition) interactions in different populations which needs to be explored. Between 2008 and 2012, 151 Down syndrome triads and 200 age-matched controls (Control mothers n = 186) were included in the study. Seven polymorphisms in six genes of folate-Hcy metabolic pathway, along with Hcy, cysteine (Cys), vitamin B12 (vit-B12) and folate levels, were analysed and compared among the case and control groups. Genotyping was performed by the PCR-RFLP technique. Levels of homocysteine and cysteine were measured by HPLC while vitamin B12 and folate were estimated by chemiluminescence. We demonstrate that polymorphisms in the folate-Hcy pathway genes in mothers collectively constitute a genotypic risk for DS which is effectively modified by interactions among genes and by the environment affecting folate, Hcy and vitamin B12 levels. The study also supports the idea that these maternal risk factors provide an adaptive advantage during pregnancy supporting live birth of the DS child. Our inability to obtain genotype and nutritional assessments of unaffected siblings of the DS children was an important limitation of the study. Also, its confinement to a specific geographic region (the eastern part) of India, and relatively small sample size

  19. Functional Genomics and Phylogenetic Evidence Suggest Genus-Wide Cobalamin Production by the Globally Distributed Marine Nitrogen Fixer Trichodesmium.

    Science.gov (United States)

    Walworth, Nathan G; Lee, Michael D; Suffridge, Christopher; Qu, Pingping; Fu, Fei-Xue; Saito, Mak A; Webb, Eric A; Sañudo-Wilhelmy, Sergio A; Hutchins, David A

    2018-01-01

    Only select prokaryotes can biosynthesize vitamin B 12 (i.e., cobalamins), but these organic co-enzymes are required by all microbial life and can be vanishingly scarce across extensive ocean biomes. Although global ocean genome data suggest cyanobacteria to be a major euphotic source of cobalamins, recent studies have highlighted that >95% of cyanobacteria can only produce a cobalamin analog, pseudo-B 12 , due to the absence of the BluB protein that synthesizes the α ligand 5,6-dimethylbenzimidizole (DMB) required to biosynthesize cobalamins. Pseudo-B 12 is substantially less bioavailable to eukaryotic algae, as only certain taxa can intracellularly remodel it to one of the cobalamins. Here we present phylogenetic, metagenomic, transcriptomic, proteomic, and chemical analyses providing multiple lines of evidence that the nitrogen-fixing cyanobacterium Trichodesmium transcribes and translates the biosynthetic, cobalamin-requiring BluB enzyme. Phylogenetic evidence suggests that the Trichodesmium DMB biosynthesis gene, bluB , is of ancient origin, which could have aided in its ecological differentiation from other nitrogen-fixing cyanobacteria. Additionally, orthologue analyses reveal two genes encoding iron-dependent B 12 biosynthetic enzymes (cbiX and isiB), suggesting that iron availability may be linked not only to new nitrogen supplies from nitrogen fixation, but also to B 12 inputs by Trichodesmium . These analyses suggest that Trichodesmium contains the genus-wide genomic potential for a previously unrecognized role as a source of cobalamins, which may prove to considerably impact marine biogeochemical cycles.

  20. Subacute combined degeneration of the cord due to folate deficiency: response to methyl folate treatment.

    OpenAIRE

    Lever, E G; Elwes, R D; Williams, A; Reynolds, E H

    1986-01-01

    Subacute combined degeneration of the cord is a rare complication of folate deficiency. Disturbance of methylation reactions in nervous tissue probably underlie subacute combined degeneration of the cord arising from folate as well as vitamin B12 deficiency. Methyl tetrahydrofolate is the form in which folic acid is transported into the CNS. Therefore methyl tetrahydrofolate treatment of the neurological and psychiatric manifestations of folate deficiency would seem to be theoretically advant...

  1. Critical evaluation of lowering the recommended dietary intake of folate.

    Science.gov (United States)

    Obeid, Rima; Koletzko, Berthold; Pietrzik, Klaus

    2014-04-01

    We evaluated the recommendation of the Austrian, German, and Swiss Societies for Nutrition of lowering dietary folate intake from 400 to 300 μg dietary folate equivalents/d. A dose-response relation exists between folate intake or plasma level and disease risk within the normal range. Improving folate status can prevent between 30% and 75% of neural tube defects. A prepregnancy plasma folate of >18.0 nmol/L (mean 26.1 nmol/L) is associated with low total homocysteine (tHcy) (folate intake cannot achieve maximal risk reduction. The Austrian, German, and Swiss Societies for Nutrition recommend that young women should additionally supplement with 400 μg folic acid at least 4 weeks before conception. This short time window is not sufficient to achieve optimal plasma folate and tHcy levels in the majority of women. Factors affecting the relation between folate intake and blood biomarkers are total folate intake, baseline plasma folate, time available for supplement use, dose and form (folic acid or methyl folate), genetic polymorphisms, physiological and lifestyle factors. Lowering the recommended dietary folate intake may have important public health consequences. Elderly people and young women are at risk for diseases related to folate shortage. Reducing birth defects through supplementation of folic acid remains a poor option, as folate intake is crucial for reaching the target protective plasma folate levels in the population. Copyright © 2014 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  2. Diagnosis and management of clinical and subclinical cobalamin deficiencies: why controversies persist in the age of sensitive metabolic testing.

    Science.gov (United States)

    Carmel, Ralph

    2013-05-01

    In the past two decades, sensitive biochemical tests have uncovered cobalamin deficiency much more frequently than ever before. Almost all cases involve mild, biochemical changes without clinical manifestations (subclinical cobalamin deficiency; SCCD), whose health impact is unclear. Because the causes of SCCD are most often unknown, nonmalabsorptive, and seldom documented, controversy and confusion surround the diagnostic criteria and, inevitably, consequences and management of SCCD. To complicate matters, our grasp of the rarer clinical deficiency, usually a serious, progressive medical disease rooted in severe malabsorption, has receded as absorption testing has disappeared. Reexamining the accumulation of assumptions and misperceptions about cobalamin deficiency and distinguishing SCCD from clinical deficiency is long overdue. The biology of cobalamin provides an important starting point: cobalamin stores exceed daily losses so greatly and binding proteins regulate absorption so effectively that deficiency typically achieves clinical expression only after years of severe, relentless malabsorption. Dietary insufficiency, mild, partial malabsorption, and other incomplete, intermittent causes can usually produce only SCCD. Thus, the most fundamental difference between the two deficiencies is the relentlessness of the underlying cause, which determines prognosis and health impact. Inattention to absorptive status has exacerbated the limitations of biochemical testing. All the biochemical tests are highly sensitive but specificity is poor, no diagnostic gold standard exists, and diagnostic cutpoints fluctuate excessively. To limit the adverse diagnostic consequences, the diagnosis of SCCD, whose need for treatment is unclear, should be deferred unless at least two tests are abnormal. Indeed, cobalamin biology indicates that the absorption system, while enhancing cobalamin delivery, also sets a strict upper limit on it, which suggests that cobalamin excess is

  3. Folate

    Science.gov (United States)

    ... aged 14-30 years (especially before and during pregnancy). Non-Hispanic black women. People with disorders that lower nutrient absorption (such as celiac disease and inflammatory bowel disease ). People with alcoholism . What happens if I don't get enough ...

  4. Composite organization of the cobalamin binding and cubilin recognition sites of intrinsic factor

    DEFF Research Database (Denmark)

    Fedosov, Sergey N; Fedosova, Natalya U; Berglund, Lars

    2005-01-01

    Intrinsic factor (IF(50)) is a cobalamin (Cbl)-transporting protein of 50 kDa, which can be cleaved into two fragments: the 30 kDa N-terminal peptide IF(30) and the 20 kDa C-terminal glycopeptide IF(20). Experiments on binding of Cbl to IF(30), IF(20), and IF(50) revealed comparable association r...

  5. Transient plasma cobalamin elevation in patients with pneumonia - two case reports

    DEFF Research Database (Denmark)

    Rahbek, Martin Torp; Scheller, Rudolf; Nybo, Mads

    2018-01-01

    We report two cases of transient significantly elevated plasma cobalamin (B12) in geriatric patients acutely admitted with fever, increased C-reactive protein and X-ray verified pneumonia. Extensive diagnostic workup did not reveal kidney or liver disease, neither any signs of cancer. Furthermore...

  6. Genetics Home Reference: cerebral folate transport deficiency

    Science.gov (United States)

    ... R. Cerebral folate deficiency syndromes in childhood: clinical, analytical, and etiologic aspects. Arch Neurol. 2011 May;68( ... 2009.08.005. Citation on PubMed or Free article on PubMed Central Toelle SP, Wille D, Schmitt ...

  7. Cysteine proteinases and cystatins

    Directory of Open Access Journals (Sweden)

    Adeliana S. Oliveira

    2003-01-01

    Full Text Available This review describeds the definition, localization, functions and examples of cysteine proteinases and their protein inhibitors in vertebrate, non-vertebrate animals and plants. These inhibitors are related with defense mechanisms of plant against pests. It also describes the factors involved in the specific cysteine proteinase-cystatin interaction and high degree of affinity and large specificity in this interaction which are not only represented by the compatibility between amino acid residues of the active site involved in catalysis, but also of all amino acid residues that participante in the enzyme-inhibitor interaction.Nesta revisão foram descritas definições, localizações, funções e exemplos de proteinases cisteínicas e suas proteinas inibidoras em animais vertebrados e invertebrados e plantas. Tratamos principalmente com aqueles inibidores que são relatados com o mecanismo de defesa da planta contra pestes. Em adição, comentamos sobre recentes trabalhos que contribuíram para uma melhor compreenção dos fatores envolvidos na interação específica proteinase cisteínica-cistatina. Por outro lado, chamamos atenção para o alto grau de afinidade e grande especificidade na interação que não são apenas representadas pela compatibilidade entre os residuos de aminoácidos do sítio ativo envolvidos na catalise, mas também de todos os resíduos de aminoácidos que participam da interação enzima-inibidor.

  8. Study on folate receptor PET imaging agent 18F-flurophenethyl folate

    International Nuclear Information System (INIS)

    Guo Congying; Zhu Jianhua; Qian Jun; Yang Yang; Shen Haixing; Zhang Zhengwei

    2009-01-01

    This work is aimed at synthesizing an 18 F-labelled folate derivative that can be used as folate-receptor induced tumor PET imaging agent. Under the optimal reaction and testing specification formulated during the cold-labeling experiments, 18 F labeling of folic acid was achieved in three steps of 18 F pre-labeling,bromination and esterification. The receptor binding property of the newly-synthesized folate radio-derivative was studied through β-lactoglobulin binding test. Tumor-bearing nude mice injected with the new compound were used to study whether the derivative can accumulate within tumor issue. Preliminary studies in vitro and in vivo showed that this new PET agent still possessed receptor binding qualities of folic acid. 18 F-flurophenethyl folate remained good affinity and specificity with β-lactoglobulin. Accumulation of activities in tumor tissues was found in tumor-bearing nude mice. A new folate receptor ligand: 18 F-flurophenethyl folate was synthesized,with high yield and good stability. Since the pre-labeling method was used, the fluorine labeling was not directly imposed upon folic acid.In this way, the structure destruction, which happens in high temperature reaction of folic acid, can be avoided. The synthesized folate derivative remained the binding structural quality of folic acid and could bind with the folate-binding protein: β-lactoglobulin. Through the folate receptors located on tumor tissues, 18 F-flurophenethyl folate accumulated in the tumor tissue, exhibiting its potential as a tumor PET imaging agent. (authors)

  9. Development of CHARMM-Compatible Force-Field Parameters for Cobalamin and Related Cofactors from Quantum Mechanical Calculations.

    Science.gov (United States)

    Pavlova, Anna; Parks, Jerry M; Gumbart, James C

    2018-02-13

    Corrinoid cofactors such as cobalamin are used by many enzymes and are essential for most living organisms. Therefore, there is broad interest in investigating cobalamin-protein interactions with molecular dynamics simulations. Previously developed parameters for cobalamins are based mainly on crystal structure data. Here, we report CHARMM-compatible force field parameters for several corrinoids developed from quantum mechanical calculations. We provide parameters for corrinoids in three oxidation states, Co 3+ , Co 2+ , and Co 1+ , and with various axial ligands. Lennard-Jones parameters for the cobalt center in the Co(II) and Co(I) states were optimized using a helium atom probe, and partial atomic charges were obtained with a combination of natural population analysis (NPA) and restrained electrostatic potential (RESP) fitting approaches. The Force Field Toolkit was used to optimize all bonded terms. The resulting parameters, determined solely from calculations of cobalamin alone or in water, were then validated by assessing their agreement with density functional theory geometries and by analyzing molecular dynamics simulation trajectories of several corrinoid proteins for which X-ray crystal structures are available. In each case, we obtained excellent agreement with the reference data. In comparison to previous CHARMM-compatible parameters for cobalamin, we observe a better agreement for the fold angle and lower RMSD in the cobalamin binding site. The approach described here is readily adaptable for developing CHARMM-compatible force-field parameters for other corrinoids or large biomolecules.

  10. Cobalamin Protection against Oxidative Stress in the Acidophilic Iron-oxidizing Bacterium Leptospirillum group II CF-1

    Directory of Open Access Journals (Sweden)

    Gloria Paz Levicán

    2016-05-01

    Full Text Available Members of the genus Leptospirillum are aerobic iron-oxidizing bacteria belonging to the phylum Nitrospira. They are important members of microbial communities that catalyze the biomining of sulfidic ores, thereby solubilizing metal ions. These microorganisms live under extremely acidic and metal-loaded environments and thus must tolerate high concentrations of reactive oxygen species. Cobalamin (vitamin B12 is a cobalt-containing tetrapyrrole cofactor involved in intramolecular rearrangement reactions and has recently been suggested to be an intracellular antioxidant. In this work, we investigated the effect of the exogenous addition of cobalamin on oxidative stress parameters in Leptospirillum group II strain CF-1. Our results revealed that the external supplementation of cobalamin reduces the levels of intracellular reactive oxygen species and the damage to biomolecules, and also stimulates the growth and survival of cells exposed to oxidative stress exerted by ferric ion, hydrogen peroxide, chromate and diamide. Furthermore, exposure of strain CF-1 to oxidative stress elicitors resulted in the transcriptional activation of the cbiA gene encoding CbiA of the cobalamin biosynthetic pathway. Altogether, these data suggest that cobalamin plays an important role in redox protection of Leptospirillum strain CF-1, supporting survival of this microorganism under extremely oxidative environmental conditions. Understanding the mechanisms underlying the protective effect of cobalamin against oxidative stress may help to develop strategies to make biomining processes more effective.

  11. Failure to thrive and life-threatening complications due to inherited selective cobalamin malabsorption effectively managed in a juvenile Australian shepherd dog

    Science.gov (United States)

    Gold, Ashley J.; Scott, Michael A.; Fyfe, John C.

    2015-01-01

    A juvenile Australian shepherd dog exhibited failure to grow, inappetence, weakness, nonregenerative anemia, neutropenia, and cobalamin deficiency. DNA testing confirmed homozygosity of an amnionless mutation (AMN c.3G > A). Clinical signs resolved with supportive care and parenteral cobalamin supplementation. Inherited selective intestinal cobalamin malabsorption requiring lifelong parenteral supplementation should be considered in Australian shepherds, giant schnauzers, border collies, and beagles that fail to thrive. PMID:26483576

  12. How well do blood folate concentrations predict dietary folate intakes in a sample of Canadian lactating women exposed to high levels of folate? An observational study.

    Science.gov (United States)

    Houghton, Lisa A; Sherwood, Kelly L; O'Connor, Deborah L

    2007-10-25

    In 1998, mandatory folic acid fortification of white flour and select cereal grain products was implemented in Canada with the intention to increase dietary folate intakes of reproducing women. Folic acid fortification has produced a dramatic increase in blood folate concentrations among reproductive age women, and a reduction in neural tube defect (NTD)-affected pregnancies. In response to improved blood folate concentrations, many health care professionals are asking whether a folic acid supplement is necessary for NTD prevention among women with high blood folate values, and how reliably high RBC folate concentrations predict folate intakes shown in randomized controlled trials to be protective against NTDs. The objective of this study was to determine how predictive blood folate concentrations and folate intakes are of each other in a sample of well-educated lactating Canadian women exposed to high levels of synthetic folate. The relationship between blood folate concentrations and dietary folate intakes, determined by weighed food records, were assessed in a sample of predominantly university-educated lactating women (32 +/- 4 yr) at 4-(n = 53) and 16-wk postpartum (n = 55). Median blood folate concentrations of all participants were well above plasma and RBC folate cut-off levels indicative of deficiency (6.7 and 317 nmol/L, respectively) and all, except for 2 subjects, were above the cut-off for NTD-risk reduction (>906 nmol/L). Only modest associations existed between total folate intakes and plasma (r = 0.46, P consuming 151-410 microg/d of synthetic folate (2nd quartile of intake) did not differ from that of women consuming >410 microg/d (3rd and 4th quartile). Folate intakes, estimated by food composition tables, and blood folate concentrations are not predictive of each other in Canadian lactating women exposed to high levels of folate. Synthetic intakes > 151-410 microg/d in these women produced little additional benefit in terms of maximizing RBC

  13. Assay of cysteine dioxygenase activity

    International Nuclear Information System (INIS)

    Bagley, P.J.; Stipanuk, M.H.

    1990-01-01

    It has been proposed that rat liver contains two cysteine dioxygenase enzymes which convert cysteine to cysteinesulfinic acid, one which is stimulated by NAD + and has a pH optimum of 6.8 and one which is not stimulated by NAD + and has a pH optimum of 9.0. This led the authors to reinvestigate assay conditions for measuring cysteine dioxygenase activity in rat liver homogenate. An HPLC method, using an anion exchange column (Dionex Amino-Pac trademark PA1 (4x250 mm)) was used to separate the [ 35 S]cysteinesulfinic acid produced from [ 35 S]cysteine in the incubation mixture. They demonstrated that inclusion of hydroxylamine prevented further metabolism of cysteinesulfinic acid. which occurred rapidly in the absence of hydroxylamine

  14. Increased uracil misincorporation in lymphocytes from folate-deficient rats

    OpenAIRE

    Duthie, S J; Grant, G; Narayanan, S

    2000-01-01

    The development of certain human cancers has been linked with inadequate intake of folates. The effects of folate deficiency in vivo on DNA stability (strand breakage, misincorporated uracil and oxidative base damage) in lymphocytes isolated from rats fed a diet deficient in folic acid was determined. Because the metabolic pathways of folate and other methyl donors are closely coupled, the effects of methionine and choline deficiency alone or in combination with folate deficiency were determi...

  15. Folates in plants: research advances and progress in crop biofortification

    Science.gov (United States)

    Gorelova, Vera; Ambach, Lars; Rébeillé, Fabrice; Stove, Christophe; Van Der Straeten, Dominique

    2017-03-01

    Folates, also known as B9 vitamins, serve as donors and acceptors in one-carbon (C1) transfer reactions. The latter are involved in synthesis of many important biomolecules, such as amino acids, nucleic acids and vitamin B5. Folates also play a central role in the methyl cycle that provides one-carbon groups for methylation reactions. The important functions fulfilled by folates make them essential in all living organisms. Plants, being able to synthesize folates de novo, serve as an excellent dietary source of folates for animals that lack the respective biosynthetic pathway. Unfortunately, the most important staple crops such as rice, potato and maize are rather poor sources of folates. Insufficient folate consumption is known to cause severe developmental disorders in humans. Two approaches are employed to fight folate deficiency: pharmacological supplementation in the form of folate pills and biofortification of staple crops. As the former approach is considered rather costly for the major part of the world population, biofortification of staple crops is viewed as a decent alternative in the struggle against folate deficiency. Therefore strategies, challenges and recent progress of folate enhancement in plants will be addressed in this review. Apart from the ever-growing need for the enhancement of nutritional quality of crops, the world population faces climate change catastrophes or environmental stresses, such as elevated temperatures, drought, salinity that severely affect growth and productivity of crops. Due to immense diversity of their biochemical functions, folates take part in virtually every aspect of plant physiology. Any disturbance to the plant folate metabolism leads to severe growth inhibition and, as a consequence, to a lower productivity. Whereas today’s knowledge of folate biochemistry can be considered very profound, evidence on the physiological roles of folates in plants only starts to emerge. In the current review we will discuss the

  16. 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.)

  17. Receptor-mediated targeting of 67Ga-Deferoxamine-Folate to folate-receptor-positive human kb tumor xenografts

    International Nuclear Information System (INIS)

    Mathias, Carla J.; Wang, Susan; Low, Philip S.; Waters, David J.; Green, Mark A.

    1999-01-01

    The radiochemical synthesis and stability of 67 Ga-deferoxamine-folate ([ 67 Ga]Ga-DF-Folate) were examined as a function of DF-Folate concentration. Optimal labeling occurred at DF-Folate concentrations ≥2.5 μg/mL. To define the possible biological significance of variations in product formulation, the biodistribution of [ 67 Ga]Ga-DF-Folate was examined as a function of administered deferoxamine-folate dose in an athymic mouse KB tumor model. The folate-receptor-positive KB tumors were found to concentrate the 67 Ga radiolabel in a dose-dependent fashion, consistent with saturable involvement of the folate receptor in mediating tumor accumulation of the radiopharmaceutical

  18. Folate overproduction in Lactobacillus plantarum WCFS1 causes methotrexate resistance

    NARCIS (Netherlands)

    Wegkamp, H.B.A.; Vos, de W.M.; Smid, E.J.

    2009-01-01

    Folate overproduction can serve as a mode of resistance against the folate antagonist methotrexate in Lactobacillus plantarum WCFS1. When compared with a wild-type control strain, an engineered high folate-producing strain was found to be insensitive to methotrexate. The growth rate and the viable

  19. Folate Metabolism and the Risk of Down Syndrome

    Science.gov (United States)

    Patterson, David

    2008-01-01

    Folate is an important vitamin that contributes to cell division and growth and is therefore of particular importance during infancy and pregnancy. Folate deficiency has been associated with slowed growth, anaemia, weight loss, digestive disorders and some behavioural issues. Adequate folate intake around the time of conception and early pregnancy…

  20. Trans and cis influences and effects in cobalamins and in their simple models.

    Science.gov (United States)

    De March, Matteo; Demitri, Nicola; Geremia, Silvano; Hickey, Neal; Randaccio, Lucio

    2012-11-01

    The interligand interactions in coordination compounds have been principally interpreted in terms of cis and trans influences and effects, which can be defined as the ability of a ligand X to affect the bond of another ligand, cis or trans to X, to the metal. This review analyzes these effects/influences in cobalamins (XCbl) and their simple models cobaloximes, LCo(chel)X. Important properties of these complexes, such as geometry, stability, and reactivity, can be rationalized in terms of steric and electronic factors of the ligands. Experimental evidence of normal and inverse trans influence is described in alkylcobaloximes for the first time. The study of simple B(12) models has complemented that on the more complex cobalamins, with particular emphasis on the properties of the axial L-Co-X moiety. Some of the conclusions reached for the axial fragment of simple models have also been qualitatively detected in cobalamins and have furnished new insight into the as yet unestablished mechanism for the homolytic cleavage of the Co - C bond in the AdoCbl-based enzymes. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Pernicious Anemia Associated Cobalamin Deficiency and Thrombotic Microangiopathy: Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Farhanah Yousaf

    2017-01-01

    Full Text Available A 43-year-old Hispanic male without significant previous medical history was brought to emergency department for syncope following a blood draw to investigate a 40 lbs weight loss during the past 6 months associated with decreased appetite and progressive fatigue. The patient also reported a 1-month history of jaundice. On examination, he was hemodynamically stable and afebrile with pallor and diffuse jaundice but without skin rash or palpable purpura. Normal sensations and power in all extremities were evident on neurological exam. Presence of hemolytic anemia, schistocytosis, thrombocytopenia, and elevated lactate dehydrogenase (LDH was suggestive of thrombotic thrombocytopenic purpura (TTP. However, presence of leukopenia, macrocytes, and an inadequate reticulocyte response to the degree of anemia served as initial clues to an alternative diagnosis. Two and one units of packed red blood cells were transfused on day 1 and day 3, respectively. In addition, one unit of platelets was transfused on day 2. Daily therapeutic plasma exchange (TPE was initiated and continued until ADAMTS-13 result ruled out TTP. A low cobalamin (vitamin B12 level was evident at initial laboratory work-up and subsequent testing revealed positive intrinsic factor-blocking antibodies supporting a diagnosis of pernicious anemia with severe cobalamin deficiency. Hematological improvement was observed following vitamin B12 supplementation. The patient was discharged and markedly improved on day 9 with outpatient follow-up for cobalamin supplementation.

  2. How well do blood folate concentrations predict dietary folate intakes in a sample of Canadian lactating women exposed to high levels of folate? An observational study

    Directory of Open Access Journals (Sweden)

    Sherwood Kelly L

    2007-10-01

    Full Text Available Abstract Background In 1998, mandatory folic acid fortification of white flour and select cereal grain products was implemented in Canada with the intention to increase dietary folate intakes of reproducing women. Folic acid fortification has produced a dramatic increase in blood folate concentrations among reproductive age women, and a reduction in neural tube defect (NTD-affected pregnancies. In response to improved blood folate concentrations, many health care professionals are asking whether a folic acid supplement is necessary for NTD prevention among women with high blood folate values, and how reliably high RBC folate concentrations predict folate intakes shown in randomized controlled trials to be protective against NTDs. The objective of this study was to determine how predictive blood folate concentrations and folate intakes are of each other in a sample of well-educated lactating Canadian women exposed to high levels of synthetic folate. Methods The relationship between blood folate concentrations and dietary folate intakes, determined by weighed food records, were assessed in a sample of predominantly university-educated lactating women (32 ± 4 yr at 4-(n = 53 and 16-wk postpartum (n = 55. Results Median blood folate concentrations of all participants were well above plasma and RBC folate cut-off levels indicative of deficiency (6.7 and 317 nmol/L, respectively and all, except for 2 subjects, were above the cut-off for NTD-risk reduction (>906 nmol/L. Only modest associations existed between total folate intakes and plasma (r = 0.46, P P nd quartile of intake did not differ from that of women consuming >410 μg/d (3rd and 4th quartile. Conclusion Folate intakes, estimated by food composition tables, and blood folate concentrations are not predictive of each other in Canadian lactating women exposed to high levels of folate. Synthetic intakes > 151–410 μg/d in these women produced little additional benefit in terms of maximizing

  3. Studies on folate binding and a radioassay for serum and whole blood folate using goat milk as binding agent

    International Nuclear Information System (INIS)

    Piyasena, R.D.; Weerasekera, D.A.; Hettiaratchi, N.; Wikramanayake, T.W.; Sri Lanka Univ., Peradeniya Campus. Nuclear Medicine Unit)

    1977-01-01

    Preparations of cow, goat, buffalo, and human milk in addition to pig plasma were tested for folate binding properties. Of these, only pig plasma and goat milk showed sufficient binding to enable use as binding agents in a radioassay for serum and whole blood folate. The binding of folate by cow mild preparations in particular was found to be very poor. (orig.) [de

  4. Folates in Asian noodles: III. Fortification, impact of processing, and enhancement of folate intakes.

    Science.gov (United States)

    Bui, Lan T T; Small, Darryl M

    2007-06-01

    Asian noodles, a widely consumed staple food, were evaluated as potential vehicles for fortification with folic acid. Samples of white salted, yellow alkaline, and instant noodles, prepared under controlled laboratory conditions, were fortified and folates were measured at each stage of processing using a microbiological assay. Although the 3 styles showed differing patterns of retention, overall losses were slightly more than 40% and were similar for all styles. White salted and yellow alkaline noodles showed no significant decrease in total folate content during production. In contrast, significant losses occurred for instant noodles during steaming and deep-frying of the noodle strands. In all cases, substantial losses occurred during subsequent cooking of the dried noodles. Fortification at a rate of 50% of the reference value per serving resulted in retention of folate at levels corresponding to 30% following cooking, whereas unfortified noodles contributed less than 4% per serving. It is concluded that fortifying Asian noodles provides an effective means for enhancing folate intake.

  5. Cysteine Protease Zymography: Brief Review.

    Science.gov (United States)

    Wilkesman, Jeff

    2017-01-01

    Cysteine proteases play multiple roles in basically all aspects of physiology and development. In plants, they are involved in growth and development and in accumulation and mobilization of storage proteins. Furthermore, they are engaged in signalling pathways and in the response to biotic and abiotic stresses. In animals and also in humans, they are responsible for senescence and apoptosis, prohormone processing, and ECM remodelling. When analyzed by zymography, the enzyme must be renaturated after SDS-PAGE. SDS must be washed out and substituted by Triton X-100. Gels are then further incubated under ideal conditions for activity detection. Cysteine proteases require an acidic pH (5.0-6.0) and a reducing agent, usually DTT. When screening biological samples, there is generally no previous clue on what peptidase class will be present, neither optimal proteolysis conditions are known. Hence, it is necessary to assess several parameters, such as incubation time, pH, temperature, influence of ions or reducing agents, and finally evaluate the inhibition profile. For detection of cysteine peptidase activity, the use of specific inhibitors, such as E-64, can be used to prevent the development of cysteine peptidase activity bands and positively confirm its presence. Here four different protocols to assess cysteine protease activity from different sources are presented.

  6. GNMT Expression Increases Hepatic Folate Contents and Folate-Dependent Methionine Synthase-Mediated Homocysteine Remethylation

    OpenAIRE

    Wang, Yi-Cheng; Chen, Yi-Ming; Lin, Yan-Jun; Liu, Shih-Ping; Chiang, En-Pei Isabel

    2011-01-01

    Glycine N-methyltransferase (GNMT) is a major hepatic enzyme that converts S-adenosylmethionine to S-adenosylhomocysteine while generating sarcosine from glycine, hence it can regulate mediating methyl group availability in mammalian cells. GNMT is also a major hepatic folate binding protein that binds to, and, subsequently, may be inhibited by 5-methyltetrafolate. GNMT is commonly diminished in human hepatoma; yet its role in cellular folate metabolism, in tumorigenesis and antifolate therap...

  7. Enhancement of the folate content in Egyptian pita bread.

    Science.gov (United States)

    Hefni, Mohammed; Witthöft, Cornelia M

    2012-01-01

    Egypt has a high incidence of neural tube defects related to folate deficiency. One major food source for folate is pita (baladi) bread, which is consumed daily. Bioprocessing (e.g. germination) has been reported to increase the folate content in cereals. The aim was to produce pita bread with increased folate content using germinated wheat flour (GWF). Prior to milling the effects of germination and drying conditions on folate content in wheat grains were studied. Pita bread was baked from wheat flour substituted with different levels of GWF. The folate content in dough and bread and rheological properties of dough were determined. Germination of wheat grains resulted in, depending on temperature, 3- to 4-fold higher folate content with a maximum of 61 µg/100 g DM (dry matter). The folate content in both flour and bread increased 1.5 to 4-fold depending on the level of flour replacement with GWF. Pita bread baked with 50% sieved GWF was acceptable with respect to colour and layer separation, and had a folate content of 50 µg/100 g DM compared with 30 µg/100 g DM in conventional pita bread (0% GWF). Using 50% GWF, pita bread with increased folate content, acceptable for the Egyptian consumer, was produced. Consumption of this bread would increase the average daily folate intake by 75 µg.

  8. Enhancement of the folate content in Egyptian pita bread

    Directory of Open Access Journals (Sweden)

    Cornelia M. Witthöft

    2012-04-01

    Full Text Available Introduction: Egypt has a high incidence of neural tube defects related to folate deficiency. One major food source for folate is pita (baladi bread, which is consumed daily. Bioprocessing (e.g. germination has been reported to increase the folate content in cereals. The aim was to produce pita bread with increased folate content using germinated wheat flour (GWF.Methods: Prior to milling the effects of germination and drying conditions on folate content in wheat grains were studied. Pita bread was baked from wheat flour substituted with different levels of GWF. The folate content in dough and bread and rheological properties of dough were determined.Results: Germination of wheat grains resulted in, depending on temperature, 3- to 4-fold higher folate content with a maximum of 61 µg/100 g DM (dry matter. The folate content in both flour and bread increased 1.5 to 4-fold depending on the level of flour replacement with GWF. Pita bread baked with 50% sieved GWF was acceptable with respect to colour and layer separation, and had a folate content of 50 µg/100 g DM compared with 30 µg/100 g DM in conventional pita bread (0% GWF.Conclusion: Using 50% GWF, pita bread with increased folate content, acceptable for the Egyptian consumer, was produced. Consumption of this bread would increase the average daily folate intake by 75 µg.

  9. Effect of germination and thermal treatments on folates in rye.

    Science.gov (United States)

    Kariluoto, Susanna; Liukkonen, Kirsi-Helena; Myllymäki, Olavi; Vahteristo, Liisa; Kaukovirta-Norja, Anu; Piironen, Vieno

    2006-12-13

    Effects of germination conditions and thermal processes on folate contents of rye were investigated. Total folate contents were determined microbiologically with Lactobacillus rhamnosus (ATCC 7469) as the growth indicator organism, and individual folates were determined by high-performance liquid chromatography after affinity chromatographic purification. Germination increased the folate content by 1.7-3.8-fold, depending on germination temperature, with a maximum content of 250 micro g/100 g dry matter. Hypocotylar roots with their notably high folate concentrations (600-1180 micro g/100 g dry matter) contributed 30-50% of the folate contents of germinated grains. Germination altered the proportions of folates, increasing the proportion of 5-methyltetrahydrofolate and decreasing the proportion of formylated folate compounds. Thermal treatments (extrusion, autoclaving and puffing, and IR and toasting) resulted in significant folate losses. However, folate levels in grains that were germinated and then were heat processed were higher than for native (nongerminated) grains. Opportunities to optimize rye processing to enhance folate levels in rye-based foods are discussed.

  10. Assessing the Association between Natural Food Folate Intake and Blood Folate Concentrations: A Systematic Review and Bayesian Meta-Analysis of Trials and Observational Studies

    OpenAIRE

    Marchetta, Claire M.; Devine, Owen J.; Crider, Krista S.; Tsang, Becky L.; Cordero, Amy M.; Qi, Yan Ping; Guo, Jing; Berry, Robert J.; Rosenthal, Jorge; Mulinare, Joseph; Mersereau, Patricia; Hamner, Heather C.

    2015-01-01

    Folate is found naturally in foods or as synthetic folic acid in dietary supplements and fortified foods. Adequate periconceptional folic acid intake can prevent neural tube defects. Folate intake impacts blood folate concentration; however, the dose-response between natural food folate and blood folate concentrations has not been well described. We estimated this association among healthy females. A systematic literature review identified studies (1 1992–3 2014) with both natural food folat...

  11. Structures of human folate receptors reveal biological trafficking states and diversity in folate and antifolate recognition.

    Science.gov (United States)

    Wibowo, Ardian S; Singh, Mirage; Reeder, Kristen M; Carter, Joshua J; Kovach, Alexander R; Meng, Wuyi; Ratnam, Manohar; Zhang, Faming; Dann, Charles E

    2013-09-17

    Antifolates, folate analogs that inhibit vitamin B9 (folic acid)-using cellular enzymes, have been used over several decades for the treatment of cancer and inflammatory diseases. Cellular uptake of the antifolates in clinical use occurs primarily via widely expressed facilitative membrane transporters. More recently, human folate receptors (FRs), high affinity receptors that transport folate via endocytosis, have been proposed as targets for the specific delivery of new classes of antifolates or folate conjugates to tumors or sites of inflammation. The development of specific, FR-targeted antifolates would be accelerated if additional biophysical data, particularly structural models of the receptors, were available. Here we describe six distinct crystallographic models that provide insight into biological trafficking of FRs and distinct binding modes of folate and antifolates to these receptors. From comparison of the structures, we delineate discrete structural conformations representative of key stages in the endocytic trafficking of FRs and propose models for pH-dependent conformational changes. Additionally, we describe the molecular details of human FR in complex with three clinically prevalent antifolates, pemetrexed (also Alimta), aminopterin, and methotrexate. On the whole, our data form the basis for rapid design and implementation of unique, FR-targeted, folate-based drugs for the treatment of cancer and inflammatory diseases.

  12. Subcellular distribution of folate and folate binding protein in renal proximal tubules

    International Nuclear Information System (INIS)

    Sharkey, C.; Hjelle, J.T.; Selhub, J.

    1986-01-01

    High affinity folate binding protein (FBP) found in brush border membranes derived from renal cortices is thought to be involved in the renal conservation of folate. To examine the mechanisms of folate recovery, the subcellular distribution of FBP and 3 H-folate in rabbit renal proximal tubules (PT) was examined using analytical cell fractionation techniques. Tubules contain 3.41 +/- 0.32 picomoles FBP/mg protein (X +/- S.D.; n = 5). Postnuclear supernates (PNS) of PT were layered atop Percoll-sucrose gradients, centrifuged, fractions collected and assayed for various marker enzymes and FBP. Pooled fractions from such gradients were subsequently treated with digitonin and centrifuged in a stoichiometric manner with the activity of the microvillar enzyme, alanylaminopeptidase (AAP); excess FBP distributed with more buoyant particles. Infusion of 3 H-folate into rabbit kidneys followed by tubule isolation and fractionation revealed a time dependent shift in distribution of radiolabel from the AAP-rich gradient fractions to a region containing more buoyant particles; radiolevel was not associated with lysosomal markers. EM-radioautography revealed grains over intracellular vesicles. These results are consistent with the hypothesis that folate is recovered by a process involving receptor-mediated endocytosis or transcytosis

  13. Prevention of Folate Deficiency by Food Fortification

    African Journals Online (AJOL)

    storage, specimens were handled as described previously.~. The results of laboratory investigations are summarised in Table H. The haemoglobin level and serum vitamin. B", concentration remained essentially unchanged in all subjects. At the end of the study, the red cell folate concentrations were greater than at the start ...

  14. 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 ...

  15. Oral versus intramuscular cobalamin treatment in megaloblastic anemia: a single-center, prospective, randomized, open-label study.

    Science.gov (United States)

    Bolaman, Zahit; Kadikoylu, Gurhan; Yukselen, Vahit; Yavasoglu, Irfan; Barutca, Sabri; Senturk, Taskin

    2003-12-01

    Cobalamin (vitamin B12) deficiency, the most common cause of megaloblastic anemia, is treated with intramuscular (IM) cobalamin. It has been suggested by some investigators that oral (p.o.) cobalamin treatment may be as effective in the treatment of this condition, with the advantages of ease of administration and lower cost. This study assessed the effects and cost of p.o. versus i.m. cobalamin treatment in patients with megaloblastic anemia due to cobalamin deficiency. This was a 90-day, prospective, randomized, open-label study conducted at the Division of Hematology, Department of Internal Medicine, Adnan Menderes University Research and Practice Hospital (Aydin, Turkey). Patients aged > or =16 years with megaloblastic anemia due to cobalamin deficiency were randomized to receive 1000-microg cobalamin p.o. once daily for 10 days (p.o. group) or 1000-microg cobalamin i.m. once daily for 10 days (i.m. group). After 10 days, both treatments were administered once a week for 4 weeks, and after that, once a month for life. Patients were assessed for the presence of reticulocytosis between treatment days 5 and 10 until it was detected. Therapeutic effectiveness was assessed by measuring hematologic parameters on days 0, 10, 30, and 90 and serum vitamin B12 concentration on days 0 and 90. The Mini-Mental State Examination was used before and after the B12 therapy for cognitive function assessment and 125-Hz diapozone was used for vibration threshold testing. Neurologic sensory assessment, including soft-touch and pinprick examinations, was used to identify neuropathy at baseline and study end. Tolerability was assessed using laboratory tests and patient interview. Cost was assessed using the cost of the study drug and of the injection. Sixty patients completed the study 26 in the p.o. group (16 men, 10 women; mean [SD] age, 60 [15] years) and 34 in the i.m. group (17 men, 17 women; mean [SD] age, 64 [10] years). Reticulocytosis was observed in all patients. In the p

  16. Folate inadequacy in the diet of pregnant women

    Directory of Open Access Journals (Sweden)

    Lívia de Castro Crivellenti

    2014-06-01

    Full Text Available OBJECTIVE: To estimate food and dietary folate inadequacies in the diets of adult pregnant women. METHODS: A prospective study was conducted with 103 healthy pregnant adult users of the Public Health Care System of Ribeirão Preto, São Paulo, Brazil. The present study included the 82 women with complete food intake data during pregnancy, which were collected by three 24-hour dietary recalls. Food folate (folate naturally present in foods and dietary folate (food folate plus folate from fortified wheat flour and cornmeal inadequacies were determined, using the Estimated Average Requirement as cutoff. RESULTS: The diets of 100% and 94% of the pregnant women were inadequate in food folate and dietary folate, respectively. However, fortified foods increased the medium availability of the nutrient by 87%. CONCLUSION: The large number of pregnant women consuming low-folate diets was alarming. Nationwide population studies are needed to confirm the hypothesized high prevalence of low-folate diets among pregnant women.

  17. Folate, colorectal cancer and the involvement of DNA methylation.

    Science.gov (United States)

    Williams, Elizabeth A

    2012-11-01

    Diet is a major factor in the aetiology of colorectal cancer (CRC). Epidemiological evidence suggests that folate confers a modest protection against CRC risk. However, the relationship is complex, and evidence from human intervention trials and animal studies suggests that a high-dose of folic acid supplementation may enhance the risk of colorectal carcinogenesis in certain circumstances. The molecular mechanisms underlying the apparent dual modulatory effect of folate on colorectal carcinogenesis are not fully understood. Folate is central to C1 metabolism and is needed for both DNA synthesis and DNA methylation, providing plausible biological mechanisms through which folate could modulate cancer risk. Aberrant DNA methylation is an early event in colorectal carcinogenesis and is typically associated with the transcriptional silencing of tumour suppressor genes. Folate is required for the production of S-adenosyl methionine, which serves as a methyl donor for DNA methylation events; thereby folate availability is proposed to modulate DNA methylation status. The evidence for an effect of folate on DNA methylation in the human colon is limited, but a modulation of DNA methylation in response to folate has been demonstrated. More research is required to clarify the optimum intake of folate for CRC prevention and to elucidate the effect of folate availability on DNA methylation and the associated impact on CRC biology.

  18. Extremely high concentration of folates in premature newborns.

    Science.gov (United States)

    Zikavska, T; Brucknerova, I

    2014-01-01

    Extremely high concentration of folates in premature newborns: case reports. Folates are a group of water soluble compounds, which are important for metabolic processes in human body. These are important during periods of rapid cell growth. The most accurate indicator of long-term folate level status in the body is the determination of red blood cell (RBC) folate concentrations. The optimal level of RBC folate is not known in neonatal period. Authors discuss the reasons for extremely high level of RBC folate concentrations. In our work we present the cases of two premature newborns with extremely high level of RBC folate concentrations, which were analyzed immunochemically on the first day of life and after six weeks of life. In both cases we measured RBC folate concentrations on the 1st day of life. After 6 weeks we found extremely high RBC folate concentration level (5516.67 ng/ml) in the first case after RBC transfusions. In second case after two months of life the RBC folate concentration level was doubled (2335.1 ng/ml) until 24 hours after RBC transfusion compared to levels after birth. The normal range of RBC folate values vary in newborns. The upper limit of daily dose of folic acid in pregnancy and neonatal period is not known. On the other hand it is an easily excreted water-soluble vitamin but in premature newborn it can lead to the disruption of metabolic balance and slow its degradation. Some factors can have an impact on RBC folate concentration. Blood transfusion can be one of the main influences on RBC folate concentration. To clarify these mechanisms further studies are required (Ref. 29).

  19. Homocysteine and reactive oxygen species in metabolic syndrome, type 2 diabetes mellitus, and atheroscleropathy: The pleiotropic effects of folate supplementation

    Directory of Open Access Journals (Sweden)

    Tyagi Suresh C

    2004-05-01

    Full Text Available Abstract Homocysteine has emerged as a novel independent marker of risk for the development of cardiovascular disease over the past three decades. Additionally, there is a graded mortality risk associated with an elevated fasting plasma total homocysteine (tHcy. Metabolic syndrome (MS and type 2 diabetes mellitus (T2DM are now considered to be a strong coronary heart disease (CHD risk enhancer and a CHD risk equivalent respectively. Hyperhomocysteinemia (HHcy in patients with MS and T2DM would be expected to share a similar prevalence to the general population of five to seven percent and of even greater importance is: Declining glomerular filtration and overt diabetic nephropathy is a major determinant of tHcy elevation in MS and T2DM. There are multiple metabolic toxicities resulting in an excess of reactive oxygen species associated with MS, T2DM, and the accelerated atherosclerosis (atheroscleropathy. HHcy is associated with an increased risk of cardiovascular disease, and its individual role and how it interacts with the other multiple toxicities are presented. The water-soluble B vitamins (especially folate and cobalamin-vitamin B12 have been shown to lower HHcy. The absence of the cystathionine beta synthase enzyme in human vascular cells contributes to the importance of a dual role of folic acid in lowering tHcy through remethylation, as well as, its action of being an electron and hydrogen donor to the essential cofactor tetrahydrobiopterin. This folate shuttle facilitates the important recoupling of the uncoupled endothelial nitric oxide synthase enzyme reaction and may restore the synthesis of the omnipotent endothelial nitric oxide to the vasculature.

  20. 35S cystein chlorhydrate preparation

    International Nuclear Information System (INIS)

    Emiliozzi, R.; Pichat, P.; Herbert, M.

    1960-01-01

    35 S cystein chlorhydrate has been prepared with a quantitative yield by electrolytic reduction of 35 S cystin in hydrochloric medium on a vibrating mercury cathode. Reprint of a paper published in Bulletin de la Societe chimique de France, no. 2653, 4. quarter 1959, p. 1544-1545 [fr

  1. Mutations in THAP11 cause an inborn error of cobalamin metabolism and developmental abnormalities.

    Science.gov (United States)

    Quintana, Anita M; Yu, Hung-Chun; Brebner, Alison; Pupavac, Mihaela; Geiger, Elizabeth A; Watson, Abigail; Castro, Victoria L; Cheung, Warren; Chen, Shu-Huang; Watkins, David; Pastinen, Tomi; Skovby, Flemming; Appel, Bruce; Rosenblatt, David S; Shaikh, Tamim H

    2017-08-01

    CblX (MIM309541) is an X-linked recessive disorder characterized by defects in cobalamin (vitamin B12) metabolism and other developmental defects. Mutations in HCFC1, a transcriptional co-regulator which interacts with multiple transcription factors, have been associated with cblX. HCFC1 regulates cobalamin metabolism via the regulation of MMACHC expression through its interaction with THAP11, a THAP domain-containing transcription factor. The HCFC1/THAP11 complex potentially regulates genes involved in diverse cellular functions including cell cycle, proliferation, and transcription. Thus, it is likely that mutation of THAP11 also results in biochemical and other phenotypes similar to those observed in patients with cblX. We report a patient who presented with clinical and biochemical phenotypic features that overlap cblX, but who does not have any mutations in either MMACHC or HCFC1. We sequenced THAP11 by Sanger sequencing and discovered a potentially pathogenic, homozygous variant, c.240C > G (p.Phe80Leu). Functional analysis in the developing zebrafish embryo demonstrated that both THAP11 and HCFC1 regulate the proliferation and differentiation of neural precursors, suggesting important roles in normal brain development. The loss of THAP11 in zebrafish embryos results in craniofacial abnormalities including the complete loss of Meckel's cartilage, the ceratohyal, and all of the ceratobranchial cartilages. These data are consistent with our previous work that demonstrated a role for HCFC1 in vertebrate craniofacial development. High throughput RNA-sequencing analysis reveals several overlapping gene targets of HCFC1 and THAP11. Thus, both HCFC1 and THAP11 play important roles in the regulation of cobalamin metabolism as well as other pathways involved in early vertebrate development. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. The functional cobalamin (vitamin B12)-intrinsic factor receptor is a novel complex of cubilin and amnionless

    DEFF Research Database (Denmark)

    Fyfe, John C; Madsen, Mette; Højrup, Peter

    2004-01-01

    Imerslund-Gräsbeck syndrome (I-GS, megaloblastic anemia 1) is an autosomal recessive disorder characterized by intestinal cobalamin (vitamin B(12)) malabsorption and proteinuria. I-GS-causing mutations are found in either of 2 genes encoding the epithelial proteins: cubilin and amnionless (AMN...... compartments. However, in cells cotransfected with AMN and the cubilin construct, cubilin trafficked to the cell surface and endosomes, and the cells exhibited IF-cobalamin endocytosis and lysosomal degradation of IF. These data indicate that cubilin and AMN are subunits of a novel cubilin/AMN (cubam) complex...

  3. Three family members with elevated plasma cobalamin, transcobalamin and soluble transcobalamin receptor (sCD320)

    DEFF Research Database (Denmark)

    Hoffmann-Lücke, Elke; Arendt, Johan F B; Nissen, Peter H

    2013-01-01

    deficiency were found. DNA sequencing of the TCN2 gene revealed several known polymorphisms not associated with highly elevated transcobalamin levels. Upon gel filtration, sCD320 eluted as a larger molecule than previously reported. By incubation with anti-transcobalamin antibodies, we precipitated both...... transcobalamin and part of sCD320. CONCLUSIONS: The high cobalamin levels were mainly explained by high levels of holoTC, possibly caused by complex formation with its soluble receptor, sCD320. The family occurrence points to a genetic explanation....

  4. Development and preclinical evaluation of new 124I-folate conjugates for PET imaging of folate receptor-positive tumors

    International Nuclear Information System (INIS)

    AlJammaz, I.; Al-Otaibi, B.; Al-Rumayan, F.; Al-Yanbawi, S.; Amer, S.; Okarvi, S.M.

    2014-01-01

    In an attempt to develop new folate radiotracers with favorable biochemical properties for detecting folate receptor-positive cancers, we have synthesized [ 124 I]-SIB- and [ 124 I]-SIP-folate conjugates using a straightforward and two-step simple reactions. Radiochemical yields for [ 124 I]-SIB- and [ 124 I]-SIP-folate conjugates were greater than 90 and 60% respectively, with total synthesis time of 30–40 min. Radiochemical purities were always greater than 98% without HPLC purification. These synthetic approaches hold considerable promise as rapid and simple method for 124 I-folate conjugate preparation with high radiochemical yield in short synthesis time. In vitro tests on KB cell line showed that the significant amounts of the radioconjugates were associated with cell fractions. In vivo characterization in normal Balb/c mice revealed rapid blood clearance of these radioconjugates and favorable biodistribution profile for [ 124 I]-SIP-folate conjugate over [ 124 I]-SIB-folate conjugate. Biodistribution studies of [ 124 I]-SIP-folate conjugate in nude mice bearing human KB cell line xenografts, demonstrated significant tumor uptake. The uptake in the tumors was blocked by excess injection of folic acid, suggesting a receptor-mediated process. These results demonstrate that [ 124 I]-SIP-folate conjugate may be useful as a molecular probe for detecting and staging of folate receptor-positive cancers, such as ovarian cancer and their metastasis as well as monitoring tumor response to treatment

  5. [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.

  6. Epigenetic Mechanisms of Folate Nutrition in Breast Cancer

    Science.gov (United States)

    2012-04-01

    MDAMB231 clones that express non-leaky TetR systems. Test effects of folate deficiency on global and gene specific DNA methylation and gene...cellular differentiation and function. Aberrant DNA methylation is a characteristic of cancer cells, including mammary tumors. The B vitamin folate ...relationships between folate , one-carbon metabolism, DNA methylation , and gene expression within the context of breast cancer. We hypothesize that

  7. 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.

  8. 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

  9. Folate Deficiency Could Restrain Decidual Angiogenesis in Pregnant Mice

    Directory of Open Access Journals (Sweden)

    Yanli Li

    2015-08-01

    Full Text Available The mechanism of birth defects induced by folate deficiency was focused on mainly in fetal development. Little is known about the effect of folate deficiency on the maternal uterus, especially on decidual angiogenesis after implantation which establishes vessel networks to support embryo development. The aim of this study was to investigate the effects of folate deficiency on decidual angiogenesis. Serum folate levels were measured by electrochemiluminescence. The status of decidual angiogenesis was examined by cluster designation 34 (CD34 immunohistochemistry and the expression of angiogenic factors, including vascular endothelial growth factor A (VEGFA, placental growth factor (PLGF, and VEGF receptor 2 (VEGFR2 were also tested. Serum levels of homocysteine (Hcy, follicle stimulating hormone (FSH, luteinizing hormone (LH, prolactin (PRL, progesterone (P4, and estradiol (E2 were detected by Enzyme-linked immunosorbent assay. The folate-deficient mice had a lower folate level and a higher Hcy level. Folate deficiency restrained decidual angiogenesis with significant abnormalities in vascular density and the enlargement and elongation of the vascular sinus. It also showed a reduction in the expressions of VEGFA, VEGFR2, and PLGF. In addition, the serum levels of P4, E2, LH, and PRL were reduced in folate-deficient mice, and the expression of progesterone receptor (PR and estrogen receptor α (ERα were abnormal. These results indicated that folate deficiency could impaire decidual angiogenesis and it may be related to the vasculotoxic properties of Hcy and the imbalance of the reproductive hormone.

  10. Hepatic folate metabolism in the chronic alcoholic monkey

    International Nuclear Information System (INIS)

    Tamura, T.; Romero, J.J.; Watson, J.E.; Gong, E.J.; Halsted, C.H.

    1981-01-01

    To assess the role of altered hepatic folate metabolism in the pathogenesis of the folate deficiency of chronic alcoholism, the hepatic metabolism of a tracer dose of 3 H-PteGlu was compared in monkeys given 50% of energy as ethanol for 2 years and in control monkeys. Long-term ethanol feeding resulted in mild hepatic injury, with a significant decrease in hepatic folate levels. Chromatographic studies of liver biopsies obtained after the tracer dose indicated that the processes of reduction, methylation, and formylation of reduced folate and the synthesis of polyglutamyl folates were not affected by long-term ethanol feeding. Hepatic tritium levels were significantly decreased in the ethanol-fed group. These studies suggest that the decrease in hepatic folate levels observed after long-term ethanol ingestion is due to a decrease in hepatic folate levels observed after long-term ethanol ingestion is due to a decreased ability to retain folates in the liver, whereas reduction and further metabolism of folates is not affected

  11. Gas chromatographic-mass spectrometric analysis of biomarkers related to folate and cobalamin status in human serum after dimercaptopropanesulfonate reduction and heptafluorobutyl chloroformate derivatization

    Czech Academy of Sciences Publication Activity Database

    Šimek, Petr; Hušek, Petr; Zahradníčková, Helena

    2008-01-01

    Roč. 80, č. 15 (2008), s. 5776-5782 ISSN 0003-2700 R&D Projects: GA ČR GA303/06/1674 Institutional research plan: CEZ:AV0Z50070508 Keywords : biomarkers * gas chromatographic * chloroformate derivatization Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 5.712, year: 2008

  12. Physiological responses to folate overproduction in Lactobacillus plantarum WCFS1

    Directory of Open Access Journals (Sweden)

    de Vos Ric CH

    2010-12-01

    Full Text Available Abstract Background Using a functional genomics approach we addressed the impact of folate overproduction on metabolite formation and gene expression in Lactobacillus plantarum WCFS1. We focused specifically on the mechanism that reduces growth rates in folate-overproducing cells. Results Metabolite formation and gene expression were determined in a folate-overproducing- and wild-type strain. Differential metabolomics analysis of intracellular metabolite pools indicated that the pool sizes of 18 metabolites differed significantly between these strains. The gene expression profile was determined for both strains in pH-regulated chemostat culture and batch culture. Apart from the expected overexpression of the 6 genes of the folate gene cluster, no other genes were found to be differentially expressed both in continuous and batch cultures. The discrepancy between the low transcriptome and metabolome response and the 25% growth rate reduction of the folate overproducing strain was further investigated. Folate production per se could be ruled out as a contributing factor, since in the absence of folate production the growth rate of the overproducer was also reduced by 25%. The higher metabolic costs for DNA and RNA biosynthesis in the folate overproducing strain were also ruled out. However, it was demonstrated that folate-specific mRNAs and proteins constitute 8% and 4% of the total mRNA and protein pool, respectively. Conclusion Folate overproduction leads to very little change in metabolite levels or overall transcript profile, while at the same time the growth rate is reduced drastically. This shows that Lactobacillus plantarum WCFS1 is unable to respond to this growth rate reduction, most likely because the growth-related transcripts and proteins are diluted by the enormous amount of gratuitous folate-related transcripts and proteins.

  13. Human folate metabolism using 14C-accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Arjomand, A; Bucholz, B A; Clifford, A J; Duecker, S R; Johnson, H; Schneider, P D; Zulim, R A.

    1999-01-01

    Folate is a water soluble vitamin required for optimal health, growth and development. It occurs naturally in various states of oxidation of the pteridine ring and with varying lengths to its glutamate chain. Folates function as one-carbon donors through methyl transferase catalyzed reactions. Low-folate diets, especially by those with suboptimal methyltransferase activity, are associated with increased risk of neural tube birth defects in children, hyperhomocysteinemic heart disease, and cancer in adults. Rapidly dividing (neoplastic) cells have a high folate need for DNA synthesis. Chemical analogs of folate (antifolates) that interfere with folate metabolism are used as therapeutic agents in cancer treatment. Although much is known about folate chemistry, metabolism of this vitamin in vivo in humans is not well understood. Since folate levels in blood and tissues are very low and methods to measure them are inadequate, the few previous studies that have examined folate metabolism used large doses of radiolabeled folic acid in patients with Hodgkins disease and cancer (Butterworth et al. 1969, Krumdieck et al. 1978). A subsequent protocol using deuterated folic acid was also insufficiently sensitive to trace a physiologic folate dose (Stites et al. 1997). Accelerator mass spectrometry (AMS) is an emerging bioanalytical tool that overcomes the limitations of traditional mass spectrometry and of decay counting of long lived radioisotopes (Vogel et al. 1995). AMS can detect attomolar concentrations of 14 C in milligram-sized samples enabling in vivo radiotracer studies in healthy humans. We used AMS to study the metabolism of a physiologic 80 nmol oral dose of 14 C-folic acid (1/6 US RDA) by measuring the 14 C-folate levels in serial plasma, urine and feces samples taken over a 150-day period after dosing a healthy adult volunteer

  14. Folate Biofortification of Potato by Tuber-Specific Expression of Four Folate Biosynthesis Genes

    NARCIS (Netherlands)

    Lepeleire, De Jolien; Strobbe, Simon; Verstraete, Jana; Blancquaert, Dieter; Ambach, Lars; Visser, Richard G.F.; Stove, Christophe; Straeten, Van Der Dominique

    2018-01-01

    Insufficient dietary intake of micronutrients, known as "hidden hunger", is a devastating global burden, affecting two billion people. Deficiency of folates (vitamin B9), which are known to play a central role in C1 metabolism, causes birth defects in at least a quarter million people annually.

  15. Association of polymorphisms in folate metabolic genes and ...

    Indian Academy of Sciences (India)

    cancer risk: a case–control study in a Chinese population. DAWEI CAI1, LIN ... 1Department of Urology, Shengjing Hospital of China Medical University, Sanhao Street 36, ... low folate intake and an increased cancer risk. Folate ... labile protein (Weisberg et al. 2001). ..... control study, systematic review, and meta-analysis.

  16. Intake of dietary folate vitamers and risk of colorectal carcinoma

    NARCIS (Netherlands)

    Konings, E.J.M.; Goldbohm, R.A.; Brants, H.A.M.; Saris, W.H.M.; Brandt, P.A. van den

    2002-01-01

    BACKGROUND. Several studies have reported inverse associations between folate intake and colorectal carcinoma risk. Few were prospective studies and none evaluated the association between the intake of individual folate vitamers and colorectal carcinoma risk. METHODS. The aim of the current study

  17. 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

  18. Physiological responses to folate overproduction in Lactobacillus plantarum WCFS1

    NARCIS (Netherlands)

    Wegkamp, A.; Mars, A.E.; Faijes, M.; Molenaar, D.; Vos, de R.C.H.; Klaus, M.J.; Hanson, A.D.; Vos, de W.M.; Smid, E.J.

    2010-01-01

    Background Using a functional genomics approach we addressed the impact of folate overproduction on metabolite formation and gene expression in Lactobacillus plantarum WCFS1. We focused specifically on the mechanism that reduces growth rates in folate-overproducing cells. Results Metabolite

  19. Modulation of folate production in lactic acid bacteria

    NARCIS (Netherlands)

    Wegkamp, H.B.A.

    2008-01-01

    Food fortification has proven to be very useful in reducing health problems associated with mal-intake of essential nutrients, such as the B-vitamin folate. Folate is used as one-carbon donor/acceptor in several biochemical processes like synthesis of DNA, RNA and some amino acids. Sufficient intake

  20. Natural variation of folate tuber content in potato

    Science.gov (United States)

    Folates are essential vitamins in the human diet. Folate deficiency is still a common worldwide problem that is linked to various serious disorders, such as birth defects, certain types of cardiovascular diseases and cancers, megaloblastic anemia, impaired cognitive performance and depression. There...

  1. Justifying the "Folate trap" in folic acid fortification programs.

    Science.gov (United States)

    Mahajan, Niraj N; Mahajan, Kshitija N; Soni, Rajani N; Gaikwad, Nilima L

    2007-01-01

    Many countries have now adopted fortification, where folic acid is added to flour and intended to benefit all with rise in blood folate level. During many transformations of folate from one form to another, a proportion is accidentally converted to N(5)-methyl-THF, an inactive metabolite, the so-called "folate trap". Consideration should be given to including B(12) as well as folic acid in any program of supplementation or food fortification to prevent NTDs. This is especially applicable to developing countries like India where the majority of women are vegetarians and have borderline levels of vitamin B(12). Administration of [6S]-5-MTHF is more effective than is folic acid supplementation at improving folate status. Therefore, we urge to reconsider the "folate trap" in folic acid fortification programs.

  2. Effect of two different sublingual dosages of vitamin B12 on cobalamin nutritional status in vegans and vegetarians with a marginal deficiency: A randomized controlled trial.

    Science.gov (United States)

    Del Bo', Cristian; Riso, Patrizia; Gardana, Claudio; Brusamolino, Antonella; Battezzati, Alberto; Ciappellano, Salvatore

    2018-02-15

    Vegetarians and vegans are more vulnerable to vitamin B 12 deficiency with severe risks of megaloblastic anemia, cognitive decline, neuropathy, and depression. An easy and simple method of supplementation consists of taking one weekly dosage of 2000 μg. However, single large oral doses of vitamin B 12 are poorly absorbed. The present research evaluates the ability of two different sublingual dosages of vitamin B 12 (350 μg/week vs 2000 μg/week) in improving cyanocobalamin (vitamin B 12 ) nutritional status in vegans and vegetarians with a marginal deficiency. A 12-week randomized, double-blind, controlled, parallel intervention trial was performed. Forty subjects with marginal vitamin B 12 deficiency were enrolled and randomly divided into two groups: test group Ld (low dose, 350 μg/week) and control group Hd (high dose, 2000 μg/week) vitamin B 12 supplementation. Blood samples were collected at baseline and after 15, 30, 60, and 90 days from the intervention for the determination of vitamin B 12 , related metabolic markers, and blood cell counts. Two-way analysis of variance showed a significant effect of time (P < 0.0001) and of time × treatment interaction (P = 0.012) on serum concentration of vitamin B 12 that increased after 90-day supplementation (Ld and Hd) compared to baseline. Both the supplements increased (P < 0.0001, time effect) the levels of holotranscobalamin, succinic acid, methionine and wellness parameter, while decreased (P < 0.0001, time effect) the levels of methylmalonic acid, homocysteine and folate compared to baseline. No difference was observed between groups (LdvsHd). No effect was detected for vitamin B 6 and blood cell count. In our experimental conditions, both supplements were able to restore adequate serum concentrations of vitamin B 12 and to improve the levels of related metabolic blood markers in subjects with a marginal deficiency. The results support the use of a sublingual dosage of 50 μg/day (350

  3. Disruption of the folate pathway in zebrafish causes developmental defects

    Directory of Open Access Journals (Sweden)

    Lee Marina S

    2012-04-01

    Full Text Available Abstract Background Folic acid supplementation reduces the risk of neural tube defects and congenital heart defects. The biological mechanisms through which folate prevents birth defects are not well understood. We explore the use of zebrafish as a model system to investigate the role of folate metabolism during development. Results We first identified zebrafish orthologs of 12 human folate metabolic genes. RT-PCR and in situ analysis indicated maternal transcripts supply the embryo with mRNA so that the embryo has an intact folate pathway. To perturb folate metabolism we exposed zebrafish embryos to methotrexate (MTX, a potent inhibitor of dihydrofolate reductase (Dhfr an essential enzyme in the folate metabolic pathway. Embryos exposed to high doses of MTX exhibited developmental arrest prior to early segmentation. Lower doses of MTX resulted in embryos with a shortened anterior-posterior axis and cardiac defects: linear heart tubes or incomplete cardiac looping. Inhibition of dhfr mRNA with antisense morpholino oligonucleotides resulted in embryonic lethality. One function of the folate pathway is to provide essential one-carbon units for dTMP synthesis, a rate-limiting step of DNA synthesis. After 24 hours of exposure to high levels of MTX, mutant embryos continue to incorporate the thymidine analog BrdU. However, additional experiments indicate that these embryos have fewer mitotic cells, as assayed with phospho-histone H3 antibodies, and that treated embryos have perturbed cell cycles. Conclusions Our studies demonstrate that human and zebrafish utilize similar one-carbon pathways. Our data indicate that folate metabolism is essential for early zebrafish development. Zebrafish studies of the folate pathway and its deficiencies could provide insight into the underlying etiology of human birth defects and the natural role of folate in development.

  4. Metagenomic and Metatranscriptomic Analyses Reveal the Structure and Dynamics of a Dechlorinating Community Containing Dehalococcoides mccartyi and Corrinoid-Providing Microorganisms under Cobalamin-Limited Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Men, Yujie; Yu, Ke; Bælum, Jacob; Gao, Ying; Tremblay, Julien; Prestat, Emmanuel; Stenuit, Ben; Tringe, Susannah G.; Jansson, Janet; Zhang, Tong; Alvarez-Cohen, Lisa; Liu, Shuang-Jiang

    2017-02-10

    ABSTRACT

    The aim of this study is to obtain a systems-level understanding of the interactions betweenDehalococcoidesand corrinoid-supplying microorganisms by analyzing community structures and functional compositions, activities, and dynamics in trichloroethene (TCE)-dechlorinating enrichments. Metagenomes and metatranscriptomes of the dechlorinating enrichments with and without exogenous cobalamin were compared. Seven putative draft genomes were binned from the metagenomes. At an early stage (2 days), more transcripts of genes in theVeillonellaceaebin-genome were detected in the metatranscriptome of the enrichment without exogenous cobalamin than in the one with the addition of cobalamin. Among these genes, sporulation-related genes exhibited the highest differential expression when cobalamin was not added, suggesting a possible release route of corrinoids from corrinoid producers. Other differentially expressed genes include those involved in energy conservation and nutrient transport (including cobalt transport). The most highly expressed corrinoidde novobiosynthesis pathway was also assigned to theVeillonellaceaebin-genome. Targeted quantitative PCR (qPCR) analyses confirmed higher transcript abundances of those corrinoid biosynthesis genes in the enrichment without exogenous cobalamin than in the enrichment with cobalamin. Furthermore, the corrinoid salvaging and modification pathway ofDehalococcoideswas upregulated in response to the cobalamin stress. This study provides important insights into the microbial interactions and roles played by members of dechlorinating communities under cobalamin-limited conditions.

    IMPORTANCEThe key

  5. Assessing the association between natural food folate intake and blood folate concentrations: a systematic review and Bayesian meta-analysis of trials and observational studies.

    Science.gov (United States)

    Marchetta, Claire M; Devine, Owen J; Crider, Krista S; Tsang, Becky L; Cordero, Amy M; Qi, Yan Ping; Guo, Jing; Berry, Robert J; Rosenthal, Jorge; Mulinare, Joseph; Mersereau, Patricia; Hamner, Heather C

    2015-04-10

    Folate is found naturally in foods or as synthetic folic acid in dietary supplements and fortified foods. Adequate periconceptional folic acid intake can prevent neural tube defects. Folate intake impacts blood folate concentration; however, the dose-response between natural food folate and blood folate concentrations has not been well described. We estimated this association among healthy females. A systematic literature review identified studies (1 1992-3 2014) with both natural food folate intake alone and blood folate concentration among females aged 12-49 years. Bayesian methods were used to estimate regression model parameters describing the association between natural food folate intake and subsequent blood folate concentration. Seven controlled trials and 29 observational studies met the inclusion criteria. For the six studies using microbiologic assay (MA) included in the meta-analysis, we estimate that a 6% (95% Credible Interval (CrI): 4%, 9%) increase in red blood cell (RBC) folate concentration and a 7% (95% CrI: 1%, 12%) increase in serum/plasma folate concentration can occur for every 10% increase in natural food folate intake. Using modeled results, we estimate that a natural food folate intake of ≥ 450 μg dietary folate equivalents (DFE)/day could achieve the lower bound of an RBC folate concentration (~ 1050 nmol/L) associated with the lowest risk of a neural tube defect. Natural food folate intake affects blood folate concentration and adequate intakes could help women achieve a RBC folate concentration associated with a risk of 6 neural tube defects/10,000 live births.

  6. Assessing the Association between Natural Food Folate Intake and Blood Folate Concentrations: A Systematic Review and Bayesian Meta-Analysis of Trials and Observational Studies

    Directory of Open Access Journals (Sweden)

    Claire M. Marchetta

    2015-04-01

    Full Text Available Folate is found naturally in foods or as synthetic folic acid in dietary supplements and fortified foods. Adequate periconceptional folic acid intake can prevent neural tube defects. Folate intake impacts blood folate concentration; however, the dose-response between natural food folate and blood folate concentrations has not been well described. We estimated this association among healthy females. A systematic literature review identified studies (1 1992–3 2014 with both natural food folate intake alone and blood folate concentration among females aged 12–49 years. Bayesian methods were used to estimate regression model parameters describing the association between natural food folate intake and subsequent blood folate concentration. Seven controlled trials and 29 observational studies met the inclusion criteria. For the six studies using microbiologic assay (MA included in the meta-analysis, we estimate that a 6% (95% Credible Interval (CrI: 4%, 9% increase in red blood cell (RBC folate concentration and a 7% (95% CrI: 1%, 12% increase in serum/plasma folate concentration can occur for every 10% increase in natural food folate intake. Using modeled results, we estimate that a natural food folate intake of ≥450 μg dietary folate equivalents (DFE/day could achieve the lower bound of an RBC folate concentration (~1050 nmol/L associated with the lowest risk of a neural tube defect. Natural food folate intake affects blood folate concentration and adequate intakes could help women achieve a RBC folate concentration associated with a risk of 6 neural tube defects/10,000 live births.

  7. Hemolytic uremic syndrome (HUS) secondary to cobalamin C (cblC) disorder.

    Science.gov (United States)

    Sharma, Ajay P; Greenberg, Cheryl R; Prasad, Asuri N; Prasad, Chitra

    2007-12-01

    Diarrhea-positive hemolytic uremic syndrome (HUS) is a common cause of acute renal failure in children. Diarrhea-negative (D-), or atypical HUS, is etiologically distinct. A Medline search identified seven previously reported D- cases of HUS secondary to cobalamin C (cblC) disease presenting in infancy. An infantile presentation is reported to be associated with a high mortality rate (6/7 cases). We describe the results of a 5-year longitudinal follow-up in a child diagnosed with D- HUS secondary to cblC disease in infancy. Mutation analysis in this patient identified homozygosity for the 271 dupA mutation (c.271 dupA) in the cblC MMACHC gene. We briefly review the published experience in cblC-associated HUS to highlight the clinical characteristics of this uncommon, but potentially treatable, condition.

  8. Advanced glycation end products overload might explain intracellular cobalamin deficiency in renal dysfunction, diabetes and aging.

    Science.gov (United States)

    Obeid, Rima; Shannan, Batool; Herrmann, Wolfgang

    2011-11-01

    Advanced glycation end products (AGEs) contribute to aging. Cobalamin (Cbl) is required for cell growth and functions, and its deficiency causes serious complications. Diabetics and renal patients show high concentrations of Cbl, but metabolic evidence of Cbl deficiency that is reversible after Cbl treatment. Cbl might be sequestered in blood and cannot be delivered to the cell. Megalin mediates the uptake of transcobalamin-Cbl complex into the proximal tubule cells. Megalin is involved in the uptake and degradation of AGEs. In aging, diabetes or renal dysfunction, AGEs might overload megalin thus lowering Cbl uptake. Transcobalamin-Cbl might retain in blood. Shedding of megalin and transcobalamin receptor under glycation conditions is also a possible mechanism of this phenomenon. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. The folate receptor as a molecular target for tumor-selective radionuclide delivery

    International Nuclear Information System (INIS)

    Ke, C.-Y.; Mathias, Carla J.; Green, Mark A.

    2003-01-01

    The cell-membrane folate receptor is a potential molecular target for tumor-selective drug delivery, including radiolabeled folate-chelate conjugates for diagnostic imaging. We review here some background on the folate receptor as tumor-associated molecular target for drug delivery, and briefly survey the literature on tumor-targeting with radiolabeled folate-chelate conjugates

  10. Developmental and feedforward control of the expression of folate biosynthesis genes in tomato fruit

    Science.gov (United States)

    Little is known about how plants regulate their folate content, including whether the expression of folate biosynthesis genes is orchestrated during development or modulated by folate levels. Nor is much known about how folate levels impact the expression of other genes. These points were addressed ...

  11. Clinical characteristics of hemolytic uremic syndrome secondary to cobalamin C disorder in Chinese children.

    Science.gov (United States)

    Li, Qi-Liang; Song, Wen-Qi; Peng, Xiao-Xia; Liu, Xiao-Rong; He, Le-Jian; Fu, Li-Bing

    2015-08-01

    The present study was undertaken to investigate the clinical characteristics of hemolytic uremic syndrome (HUS) secondary to cobalamin C disorder (cbl-C disorder). We reviewed retrospectively the medical records of 3 children with HUS secondary to cbl-C disorder who had been treated between April 1, 2009 and October 31, 2013. The 3 patients with HUS secondary to cbl-C disorder presented with progressive hemolytic anemia, acute renal failure, thrombocytopenia, poor feeding, and failure to thrive. Two of the 3 patients once had high blood pressure. The mutations of c.609G>A (p.W203X), c.217C>T (p.R73X) and c.365A>T (p.H122L) in the methylmalonic aciduria (cobalamin deficiency) cbl-C type, with homocystinuria gene were detected in the 3 patients. In these patients the levels of lactate dehydrogenase and homocysteine in serum were elevated and the level of methylmalonic acid (MMA) in urine was also elevated. After treatment with hydroxocobalamin, 2 patients were discharged with no obvious abnormal growth and neurological development and 1 patient died of multiple organ failure. The results of this study demonstrated that cbl-C disorder should be investigated in any child presenting with HUS. The high concentrations of homocysteine and MMA could be used for timely recognization of the disease. Once the high levels of plasma homocystein and/or plasma or urine MMA are detected, the treatment with parenteral hydroxocobalamin should be prescribed immediately. The early diagnosis and treatment would contribute to the good prognosis of the disease.

  12. 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)

  13. An Amoebal Grazer of Cyanobacteria Requires Cobalamin Produced by Heterotrophic Bacteria.

    Science.gov (United States)

    Ma, Amy T; Beld, Joris; Brahamsha, Bianca

    2017-05-15

    Amoebae are unicellular eukaryotes that consume microbial prey through phagocytosis, playing a role in shaping microbial food webs. Many amoebal species can be cultivated axenically in rich media or monoxenically with a single bacterial prey species. Here, we characterize heterolobosean amoeba LPG3, a recent natural isolate, which is unable to grow on unicellular cyanobacteria, its primary food source, in the absence of a heterotrophic bacterium, a Pseudomonas species coisolate. To investigate the molecular basis of this requirement for heterotrophic bacteria, we performed a screen using the defined nonredundant transposon library of Vibrio cholerae , which implicated genes in corrinoid uptake and biosynthesis. Furthermore, cobalamin synthase deletion mutations in V. cholerae and the Pseudomonas species coisolate do not support the growth of amoeba LPG3 on cyanobacteria. While cyanobacteria are robust producers of a corrinoid variant called pseudocobalamin, this variant does not support the growth of amoeba LPG3. Instead, we show that it requires cobalamin that is produced by the Pseudomonas species coisolate. The diversity of eukaryotes utilizing corrinoids is poorly understood, and this amoebal corrinoid auxotroph serves as a model for examining predator-prey interactions and micronutrient transfer in bacterivores underpinning microbial food webs. IMPORTANCE Cyanobacteria are important primary producers in aquatic environments, where they are grazed upon by a variety of phagotrophic protists and, hence, have an impact on nutrient flux at the base of microbial food webs. Here, we characterize amoebal isolate LPG3, which consumes cyanobacteria as its primary food source but also requires heterotrophic bacteria as a source of corrinoid vitamins. Amoeba LPG3 specifically requires the corrinoid variant produced by heterotrophic bacteria and cannot grow on cyanobacteria alone, as they produce a different corrinoid variant. This same corrinoid specificity is also

  14. Paracellular transport of avidin saturated or not with biotinylated cobalamin through Caco-2 cell epithelium monolayer.

    Science.gov (United States)

    Guy, M; Pons, L; Namour, F; de Nonancourt, M; Michalski, J C; Hatier, R; Guéant, J L

    2001-01-01

    The cationic charge of molecules may promote their uptake across epithelia, which are rich in brush border anionic sites. The transport of unsaturated avidin and avidin saturated with a biotinylated compound was investigated across Caco-2 adenocarcinoma cell with fetal enterocyte phenotype. The unsaturated avidin and avidin saturated with either biotin or a biotinyl-cobalamin conjugate (biotinyl-Cbl) were iodinated to follow their transport through the cell monolayer. Their apparent permeability coefficient (Papp) and transepithelial pathway were determined and compared to those for control radiolabeled markers [3H]-mannitol, [125I]-beta-lactoglobulin and [57Co]-cobalamin/intrinsic factor (Cbl/IF). The Papp of [125I]-avidin estimated at 2.8 x 10(-7) +/- 0.08 cm/s was close to that for mannitol that uses paracellular pathway. The binding of biotin or biotin conjugate to avidin enhanced its tetrameric conformation. The Papp for [125I]-avidin/biotin and [125I]- avidin/biotinyl-Cbl were respectively increased by 2-fold, compared to that for [125I]-avidin and 4-fold, compared to that for [125I]-beta-lactoglobulin and [54Co]-Cbl/IF. The protein was not accumulated in the cell and was found in intact form in the basolateral side, after its transport across the monolayer. Chloroquine (0.66 micromol/ml) did not significantly decrease the Papp for [125I]-avidin/biotinyl-Cbl. Conversely it decreased by 80% the Papp for Cbl/IF, that uses transepithelial pathway. Avidin (either saturated or not with biotin and biotinyl-Cbl) was able to cross the monolayer of Caco-2 cell line through a paracellular pathway. This study pointed out the interest for using this protein as a shuttle for increasing the transport rate of biotinylated compounds through fetal epithelial barriers. Copyright 2001 S. Karger AG, Basel

  15. Folate status and concentrations of serum folate forms in the US population: National Health and Nutrition Examination Survey 2011–2

    OpenAIRE

    Pfeiffer, Christine M.; Sternberg, Maya R.; Fazili, Zia; Lacher, David A.; Zhang, Mindy; Johnson, Clifford L.; Hamner, Heather C.; Bailey, Regan L.; Rader, Jeanne I.; Yamini, Sedigheh; Berry, R. J.; Yetley, Elizabeth A.

    2015-01-01

    Serum and red blood cell (RBC) total folate are indicators of folate status. No nationally representative population data exist for folate forms. We measured serum folate forms [5-methyltetrahydrofolate (5-methylTHF), unmetabolized folic acid (UMFA), non-methyl folate (sum of THF, 5-formylTHF, 5,10-methenylTHF), and MeFox (5-methylTHF oxidation product)] by HPLC-MS/MS and RBC total folate by microbiologic assay in US persons ≥1 year (n ~7500) participating in the National Health and Nutrition...

  16. Folate targeted polymeric 'green' nanotherapy for cancer

    International Nuclear Information System (INIS)

    Narayanan, Sreeja; Binulal, N S; Mony, Ullas; Manzoor, Koyakutty; Nair, Shantikumar; Menon, Deepthy

    2010-01-01

    The concept of 'green' chemotherapy by employing targeted nanoparticle mediated delivery to enhance the efficacy of phytomedicines is reported. Poly (lactide-co-glycolide) (PLGA) nanoparticles encapsulating a well known nutraceutical namely, grape seed extract (GSE)-'NanoGSE'-was prepared by a nanoprecipitation technique. The drug-loaded nanoparticles of size ∼ 100 nm exhibited high colloidal stability at physiological pH. Molecular receptor targeting of this nanophytomedicine against folate receptor over-expressing cancers was demonstrated in vitro by conjugation with a potential cancer targeting ligand, folic acid (FA). Fluorescence microscopy and flow cytometry data showed highly specific cellular uptake of FA conjugated NanoGSE on folate receptor positive cancer cells. Studies were also conducted to investigate the efficiency of targeted (FA conjugated) versus non-targeted (non-FA conjugated) nanoformulations in causing cancer cell death. The IC 50 values were lowered by a factor of ∼ 3 for FA-NanoGSE compared to the free drug, indicating substantially enhanced bioavailability to the tumor cells, sparing the normal ones. Receptor targeting of FA-NanoGSE resulted in a significant increase in apoptotic index, which was also quantified by flow cytometry and fluorescence microscopy. This in vitro study provides a basis for the use of nanoparticle mediated delivery of anticancer nutraceuticals to enhance bioavailability and effectively target cancer by a 'green' approach.

  17. Effects of industrial processing on folate content in green vegetables.

    Science.gov (United States)

    Delchier, Nicolas; Ringling, Christiane; Le Grandois, Julie; Aoudé-Werner, Dalal; Galland, Rachel; Georgé, Stéphane; Rychlik, Michael; Renard, Catherine M G C

    2013-08-15

    Folates are described to be sensitive to different physical parameters such as heat, light, pH and leaching. Most studies on folates degradation during processing or cooking treatments were carried out on model solutions or vegetables only with thermal treatments. Our aim was to identify which steps were involved in folates loss in industrial processing chains, and which mechanisms were underlying these losses. For this, the folates contents were monitored along an industrial canning chain of green beans and along an industrial freezing chain of spinach. Folates contents decreased significantly by 25% during the washing step for spinach in the freezing process, and by 30% in the green beans canning process after sterilisation, with 20% of the initial amount being transferred into the covering liquid. The main mechanism involved in folate loss during both canning green beans and freezing spinach was leaching. Limiting the contact between vegetables and water or using steaming seems to be an adequate measure to limit folates losses during processing. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Role of folate in nonalcoholic fatty liver disease.

    Science.gov (United States)

    Sid, Victoria; Siow, Yaw L; O, Karmin

    2017-10-01

    Nonalcoholic fatty liver disease (NAFLD) is a spectrum of chronic liver conditions that are characterized by steatosis, inflammation, fibrosis, and liver injury. The global prevalence of NAFLD is rapidly increasing in proportion to the rising incidence of obesity and type 2 diabetes. Because NAFLD is a multifaceted disorder with many underlying metabolic abnormalities, currently, there is no pharmacological agent that is therapeutically approved for the treatment of this disease. Folate is a water-soluble B vitamin that plays an essential role in one-carbon transfer reactions involved in nucleic acid biosynthesis, methylation reactions, and sulfur-containing amino acid metabolism. The liver is the primary organ responsible for storage and metabolism of folates. Low serum folate levels have been observed in patients with obesity and diabetes. It has been reported that a low level of endogenous folates in rodents perturbs folate-dependent one-carbon metabolism, and may be associated with development of metabolic diseases such as NAFLD. This review highlights the biological role of folate in the progression of NAFLD and its associated metabolic complications including obesity and type 2 diabetes. Understanding the role of folate in metabolic disease may position this vitamin as a potential therapeutic for NAFLD.

  19. Protein cysteine oxidation in redox signaling

    DEFF Research Database (Denmark)

    Forman, Henry Jay; Davies, Michael J; Krämer, Anna C

    2017-01-01

    Oxidation of critical signaling protein cysteines regulated by H2O2 has been considered to involve sulfenic acid (RSOH) formation. RSOH may subsequently form either a sulfenyl amide (RSNHR') with a neighboring amide, or a mixed disulfide (RSSR') with another protein cysteine or glutathione. Previ...

  20. Synthesis and biological assessment of folate-accepted developer (99m)Tc-DTPA-folate-polymer.

    Science.gov (United States)

    Chen, Fei; Shao, Kejing; Zhu, Bao; Jiang, Mengjun

    2016-05-15

    A novel cancer-targetable folate-poly(2-hydroxyethyl methacrylate) (PFDH) copolymer containing DTPA segment was prepared by conventional chemical synthesis and labeled with (99m)Tc subsequently. The (99m)Tc-labled PFDH could be produced easily with high radiochemical yield of 91% and radiochemical purity of 95%. The LogP octanol-water value for the (99m)Tc-labled PFDH was -2.19 and the radiotracer was stable in phosphate-buffered saline and human serum for 2h (>95% in PBS or ∼90% in human serum). To investigate (99m)Tc-labled PFDH tumor targeting, the in vitro and in vivo stability, cell uptake, in vivo biodistribution, and SPECT imaging were evaluated, respectively. These preliminary results strongly suggest that the novel folate conjugated dendrimer maybe developed to be potential for delivery of therapeutic radionuclides. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Megalin binds and mediates cellular internalization of folate binding protein

    DEFF Research Database (Denmark)

    Birn, Henrik; Zhai, Xiaoyue; Holm, Jan

    2005-01-01

    Folate is an essential vitamin involved in a number of biological processes. High affinity folate binding proteins (FBPs) exist both as glycosylphosphatidylinositol-linked, membrane associated folate binding proteins and as soluble FBPs in plasma and some secretory fluids such as milk, saliva...... to express high levels of megalin, is inhibitable by excess unlabeled FBP and by receptor associated protein, a known inhibitor of binding to megalin. Immortalized rat yolk sac cells, representing an established model for studying megalin-mediated uptake, reveal (125)I-labeled FBP uptake which is inhibited...

  2. Cryptophane-Folate Biosensor for 129Xe NMR

    Science.gov (United States)

    2014-12-01

    normal adult tissue, but as the name implies, this low affinity folate carrier is specific for the physiological form of reduced folic acid, 5- methyl ...yield. Finally, 3 was treated with 1.5 equiv of 6 and N- methyl -1,5,9-triazabicyclo[4.4.0]-decene (MTBD) in dry DMSO to give the folate recognition moiety...Cryptophane- Folate Biosensor for 129Xe NMR Najat S. Khan, Brittany A. Riggle, Garry K. Seward, Yubin Bai, and Ivan J. Dmochowski* Department of

  3. Yeast genes involved in regulating cysteine uptake affect production of hydrogen sulfide from cysteine during fermentation.

    Science.gov (United States)

    Huang, Chien-Wei; Walker, Michelle E; Fedrizzi, Bruno; Gardner, Richard C; Jiranek, Vladimir

    2017-08-01

    An early burst of hydrogen sulfide (H2S) produced by Saccharomyces cerevisiae during fermentation could increase varietal thiols and therefore enhance desirable tropical aromas in varieties such as Sauvignon Blanc. Here we attempted to identify genes affecting H2S formation from cysteine by screening yeast deletion libraries via a colony colour assay on media resembling grape juice. Both Δlst4 and Δlst7 formed lighter coloured colonies and produced significantly less H2S than the wild type on high concentrations of cysteine, likely because they are unable to take up cysteine efficiently. We then examined the nine known cysteine permeases and found that deletion of AGP1, GNP1 and MUP1 led to reduced production of H2S from cysteine. We further showed that deleting genes involved in the SPS-sensing pathway such as STP1 and DAL81 also reduced H2S from cysteine. Together, this study indirectly confirms that Agp1p, Gnp1p and Mup1p are the major cysteine permeases and that they are regulated by the SPS-sensing and target of rapamycin pathways under the grape juice-like, cysteine-supplemented, fermentation conditions. The findings highlight that cysteine transportation could be a limiting factor for yeast to generate H2S from cysteine, and therefore selecting wine yeasts without defects in cysteine uptake could maximise thiol production potential. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Reduced levels of folate transporters (PCFT and RFC) in membrane lipid rafts result in colonic folate malabsorption in chronic alcoholism.

    Science.gov (United States)

    Wani, Nissar Ahmad; Kaur, Jyotdeep

    2011-03-01

    We studied the effect of chronic ethanol ingestion on folate transport across the colonic apical membranes (CAM) in rats. Male Wistar rats were fed 1 g/kg body weight/day ethanol (20%) solution orally for 3 months and folate transport was studied in the isolated colon apical membrane vesicles. The folate transport was found to be carrier mediated, saturable, with pH optima at 5.0. Chronic ethanol ingestion reduced the folate transport across the CAM by decreasing the affinity of transporters (high Km) for the substrate and by decreasing the number of transporter molecules (low Vmax) on the colon luminal surface. The decreased transport activity at the CAM was associated with down-regulation of the proton-coupled folate transporter (PCFT) and the reduced folate carrier (RFC) which resulted in decreased PCFT and RFC protein levels in the colon of rats fed alcohol chronically. Moreover, the PCFT and the RFC were found to be distributed in detergent insoluble fraction of the CAM in rats. Floatation experiments on Optiprep density gradients demonstrated the association of the PCFT and the RFC protein with lipid rafts (LR). Chronic alcoholism decreased the PCFT and the RFC protein levels in the CAM LR in accordance with the decreased synthesis. Hence, we propose that downregulation in the expression of the PCFT and the RFC in colon results in reduced levels of these transporters in colon apical membrane LR as a mechanism of folate malabsorption during chronic alcoholism. Copyright © 2010 Wiley-Liss, Inc.

  5. Absorption of food cobalamins assessed by the double isotope method in healthy volunteers and in patients with chronic diarrhoea

    International Nuclear Information System (INIS)

    Kittang, B.; Hamborg, B.; Schjoensby, H.

    1985-01-01

    To make a food preparation containing radioactively labelled cobalamins, rabbits were given repeated injections with 57 Co-labelled cyanocobalamin. The liver was removed, homogenized and fried for one min. or boiled for 30 min. Of the radioactivity in the fried homogenate, 41.7% was recovered in the centrifuged supernatant compared with 50.8% in the boiled homogenate. The radioactivity in the supernatants had a molecular size close to that of free 57 Co-labelled cyanocobalamin. 42% of the radioactivity in the whole homogenate had been incorporated into 5-deoxyadenosyl-, 10% into methyl-and 16.5% into hydroxy-cobalamin. To assess the validity of a double-isotope method for measuring the intestinal absorption of doses of 57 Co-labelled liver cobalamins, 51 CrCl 3 was used as a non-absorbable marker. In 14 healthy volunteers the correlation coefficient between the absorption measured by the double-isotope technique and the faecal excretion test was highly significant (r = 0.96, p 57 Co/ 51 Cr ratio in successive stool collections. In 11 patients with chronic diarrhoea there was a significant correlation between the absorption measured by the double-isotope technique and the faecal excretion test (r = 0.92, p 57 / 51 Cr ratio in successive stool collections

  6. [High plasma folate in patients with phenylketonuria].

    Science.gov (United States)

    Zielińska, Magdalena; Żółkowska, Joanna; Przybylska-Kruszewska, Amanda; Gładysz, Dominika; Korycińska-Chaaban, Dorota; Nowacka, Maria; Hozyasz, Kamil K

    2016-04-01

    Phenylketonuria is an inborn error of metabolism treated with a closely monitored low phenylalanine diet. Protein substitutes used for treatment are supplemented with vitamins and micronutrients. The aim of this study was to investigate plasma folic acid concentrations in children with phenylketonuria. Retrospective analysis of medical records of 73 patients with phenylketonuria and 28 with mild hyperphenylalaninemia (on normal diet) was carried out. Intake of folic acid was calculated on the basis of protein substitute intake. Folate concentrations were analyzed according to their intake, and concentration of homocysteine and phenylalanine. In 76.7% patients with phenylketonuria intake of folic acid exceeded recommended dietary allowance. Serum folic acid concentrations above upper reference level were detected in 75.3% patients with phenylketonuria and only in 25% patients with hyperphenylalaninemia (pphenylketonuria requires further detailed research. © 2016 MEDPRESS.

  7. High folate production by naturally occurring Lactobacillus sp. with ...

    African Journals Online (AJOL)

    African Journal of Biotechnology. Journal Home ... Milk products are good sources of such vitamins which are produced by probiotics. In order to ... Therefore, two new strains with an ability of high folate production were isolated and identified.

  8. New Roles of Folate Receptor Alpha in Oncogenic Cell Signalling

    DEFF Research Database (Denmark)

    Hansen, Mariann Fagernæs

    I løbet af sine ph.d.-studier har Mariann Fagernæs Hansen undersøgt proteinet Folat Receptoren, der naturligt kan binde folinsyre. Folat Receptoren har betydning for cellevækst og er til stede på overfladen af mange kræftceller. I mange lande tilsættes folinsyre aktivt i f.eks. mel- og morgenmads......I løbet af sine ph.d.-studier har Mariann Fagernæs Hansen undersøgt proteinet Folat Receptoren, der naturligt kan binde folinsyre. Folat Receptoren har betydning for cellevækst og er til stede på overfladen af mange kræftceller. I mange lande tilsættes folinsyre aktivt i f.eks. mel- og...

  9. High folate production by naturally occurring Lactobacillus sp. with ...

    African Journals Online (AJOL)

    USER

    2010-08-16

    Aug 16, 2010 ... high folate production, isolation and identification of Lactobacilli in traditional fermented milk ... mended for pregnant women (Van Der Put et al., 2001; ...... utilization of folic acid and vitamin B12 by lactic cultures in skim milk.

  10. Dynamics of antifolate transport via the reduced folate carrier and the membrane folate receptor in murine leukaemia cells in vitro and in vivo

    NARCIS (Netherlands)

    Mauritz, Robert; Peters, Godefridus; Kathmann, Ietje; Teshale, Habte; Noordhuis, Paul; Comijn, Elizabeth; Pinedo, Herbert; Jansen, Gerrit

    Murine L1210 leukaemia cells expressing either the reduced folate carrier (RFC) or the membrane folate receptor (MFR) were studied in vitro and in vivo to assess the dynamics of membrane transport of two categories antifolates; folate-based inhibitors of dihydrofolate reductase (methotrexate,

  11. Evidence for cysteine sulfinate as a neurotransmitter

    International Nuclear Information System (INIS)

    Recasens, M.; Varga, V.; Nanopoulos, D.; Saadoun, F.; Vincendon, G.; Benavides, J.

    1982-01-01

    The Na + -independent binding of L-[ 3 H]cysteine sulfinate and L-[ 3 H]cysteine sulfinate uptake were investigated in rat brain membranes and vesicles. Specific binding of L-[ 3 H]cysteine sulfinate was saturable and occurred by a single high affinity process with a Ksub(b) of 100 nM +- 9 and a capacity (Bsub(max)) of 2.4 +- 0.22 pmol/mg protein. The regional distribution of the binding of L-[ 3 H]cysteine sulfinate in the brain was found to be heterogeneous. The rate of L-[ 3 H]cysteine sulfinate uptake shows a biphasic dependence on the concentration of L-cysteine sulfinate, corresponding to a high affinity (27.2 μM) and a low affinity (398 μM) transport system. The maximum L-[ 3 H]cysteine sulfinate uptake is reached at 2min and the uptake increases as a function of the sodium concentration. Chloride and potassium ions stimulate the uptake. (Auth.)

  12. Effect of intramuscular injection of butafosfan and cobalamin on the quality of Fresh and Cooled Stallion Semen

    Directory of Open Access Journals (Sweden)

    Nicolás Cazales Penino

    2015-08-01

    Full Text Available The use of butafosfan in combination with cobalamin modulates many cellular metabolic functions in several species. Its use enhances productive and reproductive performance and reduces stress responses in animals. Despite all these attributes, so far there have been no controlled studies to evaluate the effects of butafosfan and cobalamin on the quality of stallion semen. The purpose of this study was to evaluate the action of butafosfan in combination with cobalamin on the quality of fresh and cooled stallion semen. Four healthy stallions were kept in the same place and under the same management conditions during the entire experiment. Stallions were randomly assigned to two treatment groups in a 2x2 crossover design. Group A stallions were treated with an intramuscular injection of butafosfan twice a week for 80 days, while group B did not receive any treatment. After that, both groups were not treated for another 80 days allowing a washout period for the treated group. Then, the groups were reversed, and group B was treated with butafosfan and group A acted as the control for another 80 days. Semen was collected twice a week, diluted in skim milk and evaluated for total sperm count, total and progressive sperm motility, membrane integrity (CFDA/PI staining and membrane functionality (HOS test at 0 and 24 hours after preservation at 5ºC. Data were analyzed by comparing the values obtained from the treated stallions between the 60th and 84th days of treatment and the values obtained from the same stallion during the control period. The ejaculates of the washout period and between days 1 and 63 of treatment were not considered. A total of 85 ejaculates were analyzed by one-way ANOVA. Means were compared by the Tukey test at the 5% level of significance. No significant differences were observed in fresh and cooled semen regarding the total sperm count, total motility, progressive motility, membrane integrity and membrane functionality in the

  13. Folates in foods: reactivity, stability during processing, and nutritional implications.

    Science.gov (United States)

    Hawkes, J G; Villota, R

    1989-01-01

    Nutritional deficiencies are eminent at all socioeconomic levels of the world population and have created a critical need for a reevaluation of the nutritional quality of the food supply. A particular group of vitamers, collectively referred to as folates, has received a great deal of attention due to their significance in human metabolism, their prevalent deficiency worldwide, as well as their complexity of analysis. Severe folate deficiency may result in megaloblastic anemia and is generally attributed to low dietary intake, although it may also result from malabsorption. Such concerns have instigated increased interest in food-fortification programs. In order to ensure appropriate levels of nutrient fortification and optimization of food processes for maximum folate retention, it is of great importance to have a basic understanding of the kinetic behavior of individual vitamers with respect to processing parameters and various environmental conditions. This article reviews kinetic stability of folates as affected by processing conditions, discusses problems associated with current methodology for folate analyses, and integrates this information with the nutritional aspects of folates.

  14. [Folates and fetal programming: role of epigenetics and epigenomics].

    Science.gov (United States)

    Guéant, Jean-Louis; Daval, Jean-Luc; Vert, Paul; Nicolas, Jean-Pierre

    2012-12-01

    Folates are needed for synthesis of methionine, the precursor of S-adenosyl methionine (SAM). They play therefore a key role in nutrition and epigenomics by fluxing monocarbons towards synthesis or methylation of DNA and RNA, and methylation of gene transregulators, respectively. The deficiency produces intrauterine growth retardation and birth dejects. Folate deficiency deregulates epigenomic mechanisms related to fetal programming through decreased cellular availability of SAM. Epigenetic mechanisms of folate deficiency are illustrated by inheritance of coat colour of agouti mice model and altered expression of Igf2/H19 imprinting genes. Dietary exposure to fumonisin FB1 acts synergistically with folate deficiency on alterations of heterochromatin assembly. Deficiency in folate and vitamin B12 produces impaired fatty acid oxidation in liver and heart through imbalanced methylation and acetylation of PGC1-alpha and decreased expression of SIRT1, and long-lasting cognitive disabilities through impaired hippocampal cell proliferation, differentiation and plasticity and atrophy of hippocampal CA1. Deciphering these mechanisms will help understand the discordances between experimental models and population studies on folate supplementation.

  15. Erythrocyte folate, plasma folate and plasma homocysteine during normal pregnancy and postpartum: a longitudinal study comprising 404 danish women

    DEFF Research Database (Denmark)

    Milman, N; Byg, KE; Hvas, Anne-Mette

    2006-01-01

    OBJECTIVE: To assess folate and homocysteine status during normal pregnancy and postpartum in a longitudinal setting. METHODS: This study, performed in 1995-1996, comprised 404 healthy pregnant Danish Caucasian women residential in Copenhagen County. Women taking folic acid tablets or vitamin B12...... injections were not included. Dietary multivitamin supplements containing folic acid 100 microg or vitamin B12 1 microg, taken by 34%, were discontinued at inclusion. Participants had normal renal function. Folate status [erythrocyte (Ery-) folate, plasma (P-) folate, P-homocysteine] was measured at 18, 32...... new guidelines for folic acid supplement since 1997, only 13% of pregnant women followed the guidelines in 2003. The official recommendations for periconceptional folic acid supplement should be reconsidered and reinforced....

  16. Development of new folate-based PET radiotracers: preclinical evaluation of 68Ga-DOTA-folate conjugates

    International Nuclear Information System (INIS)

    Fani, Melpomeni; Maecke, Helmut R.; Wang, Xuejuan; Nicolas, Guillaume; Medina, Christelle; Raynal, Isabelle; Port, Marc

    2011-01-01

    A number of 111 In- and 99m Tc-folate-based tracers have been evaluated as diagnostic agents for imaging folate receptor (FR)-positive tumours. A 68 Ga-folate-based radiopharmaceutical would be of great interest, combining the advantages of PET technology and the availability of 68 Ga from a generator. The aim of the study was to develop a new 68 Ga-folate-based PET radiotracer. Two new DOTA-folate conjugates, named P3026 and P1254, were synthesized using the 1,2-diaminoethane and 3-{2-[2-(3-amino-propoxy)-ethoxy]-ethoxy}-propylamine as a spacer, respectively. Both conjugates were labelled with 67/68 Ga. Binding affinity, internalization and externalization studies were performed using the FR-positive KB cell line. Biodistribution and PET/CT imaging studies were performed in nude mice, on a folate-deficient diet, bearing KB and HT1080 (FR-negative) tumours, concurrently. The new radiotracers were evaluated comparatively to the reference molecule 111 In-DTPA-folate ( 111 In-P3139). The K d values of 67/68 Ga-P3026 (4.65 ± 0.82 nM) and 67/68 Ga-P1254 (4.27 ± 0.42 nM) showed high affinity for the FR. The internalization rate followed the order 67/68 Ga-P3026 > 67/68 Ga-P1254 > 111 In-P3139, while almost double cellular retention was found for 67/68 Ga-P3026 and 67/68 Ga-P1254, compared to 111 In-P3139. The biodistribution data of 67/68 Ga-DOTA-folates showed high and receptor-mediated uptake on the FR-positive tumours and kidneys, with no significant differences compared to 111 In-P3139. PET/CT images, performed with 68 Ga-P3026, showed high uptake in the kidneys and clear visualization of the FR-positive tumours. The DOTA-folate conjugates can be efficiently labelled with 68 Ga in labelling yields and specific activities which allow clinical application. The characteristics of the 67/68 Ga-DOTA-folates are comparable to 111 In-DTPA-folate, which has already been used in clinical trials, showing that the new conjugates are promising candidates as PET radiotracers

  17. Atopy, asthma, and lung function in relation to folate and vitamin B(12) in adults

    DEFF Research Database (Denmark)

    Thuesen, B H; Husemoen, L L N; Ovesen, L

    2010-01-01

    Recent studies suggested low serum folate and impaired folate metabolism as potential risk factors for development of asthma and atopic disease, but the results are inconsistent. The aim of this study was to investigate the relations of markers of folate and vitamin B12 (B12) deficiency with diff......Recent studies suggested low serum folate and impaired folate metabolism as potential risk factors for development of asthma and atopic disease, but the results are inconsistent. The aim of this study was to investigate the relations of markers of folate and vitamin B12 (B12) deficiency...

  18. The Extracellular Heme-binding Protein HbpS from the Soil Bacterium Streptomyces reticuli Is an Aquo-cobalamin Binder*

    Science.gov (United States)

    Ortiz de Orué Lucana, Darío; Fedosov, Sergey N.; Wedderhoff, Ina; Che, Edith N.; Torda, Andrew E.

    2014-01-01

    The extracellular protein HbpS from Streptomyces reticuli interacts with iron ions and heme. It also acts in concert with the two-component sensing system SenS-SenR in response to oxidative stress. Sequence comparisons suggested that the protein may bind a cobalamin. UV-visible spectroscopy confirmed binding (Kd = 34 μm) to aquo-cobalamin (H2OCbl+) but not to other cobalamins. Competition experiments with the H2OCbl+-coordinating ligand CN− and comparison of mutants identified a histidine residue (His-156) that coordinates the cobalt ion of H2OCbl+ and substitutes for water. HbpS·Cobalamin lacks the Asp-X-His-X-X-Gly motif seen in some cobalamin binding enzymes. Preliminary tests showed that a related HbpS protein from a different species also binds H2OCbl+. Furthermore, analyses of HbpS-heme binding kinetics are consistent with the role of HbpS as a heme-sensor and suggested a role in heme transport. Given the high occurrence of HbpS-like sequences among Gram-positive and Gram-negative bacteria, our findings suggest a great functional versatility among these proteins. PMID:25342754

  19. Late Onset Cobalamin Disorder and Hemolytic Uremic Syndrome: A Rare Cause of Nephrotic Syndrome

    Directory of Open Access Journals (Sweden)

    Gianluigi Ardissino

    2017-01-01

    Full Text Available Hemolytic uremic syndrome (HUS is an unrare and severe thrombotic microangiopathy (TMA caused by several pathogenetic mechanisms among which Shiga toxin-producing Escherichia coli infections and complement dysregulation are the most common. However, very rarely and particularly in neonates and infants, disorders of cobalamin metabolism (CblC can present with or be complicated by TMA. Herein we describe a case of atypical HUS (aHUS related to CblC disease which first presented in a previously healthy boy at age of 13.6 years. The clinical picture was initially dominated by nephrotic range proteinuria and severe hypertension followed by renal failure. The specific treatment with high dose of hydroxycobalamin rapidly obtained the remission of TMA and the complete recovery of renal function. We conclude that plasma homocysteine and methionine determinations together with urine organic acid analysis should be included in the diagnostic work-up of any patient with TMA and/or nephrotic syndrome regardless of age.

  20. A Rich Man, Poor Man Story of S-Adenosylmethionine and Cobalamin Revisited.

    Science.gov (United States)

    Bridwell-Rabb, Jennifer; Grell, Tsehai A J; Drennan, Catherine L

    2018-06-20

    S-adenosylmethionine (AdoMet) has been referred to as both "a poor man's adenosylcobalamin (AdoCbl)" and "a rich man's AdoCbl," but today, with the ever-increasing number of functions attributed to each cofactor, both appear equally rich and surprising. The recent characterization of an organometallic species in an AdoMet radical enzyme suggests that the line that differentiates them in nature will be constantly challenged. Here, we compare and contrast AdoMet and cobalamin (Cbl) and consider why Cbl-dependent AdoMet radical enzymes require two cofactors that are so similar in their reactivity. We further carry out structural comparisons employing the recently determined crystal structure of oxetanocin-A biosynthetic enzyme OxsB, the first three-dimensional structural data on a Cbl-dependent AdoMet radical enzyme. We find that the structural motifs responsible for housing the AdoMet radical machinery are largely conserved, whereas the motifs responsible for binding additional cofactors are much more varied.

  1. Folate status and concentrations of serum folate forms in the US population: National Health and Nutrition Examination Survey 2011–2

    Science.gov (United States)

    Pfeiffer, Christine M.; Sternberg, Maya R.; Fazili, Zia; Lacher, David A.; Zhang, Mindy; Johnson, Clifford L.; Hamner, Heather C.; Bailey, Regan L.; Rader, Jeanne I.; Yamini, Sedigheh; Berry, R. J.; Yetley, Elizabeth A.

    2016-01-01

    Serum and red blood cell (RBC) total folate are indicators of folate status. No nationally representative population data exist for folate forms. We measured serum folate forms [5-methyltetrahydrofolate (5-methylTHF), unmetabolized folic acid (UMFA), non-methyl folate (sum of THF, 5-formylTHF, 5,10-methenylTHF), and MeFox (5-methylTHF oxidation product)] by HPLC-MS/MS and RBC total folate by microbiologic assay in US persons ≥1 year (n ~7500) participating in the National Health and Nutrition Examination Survey 2011–2. Data analysis for serum total folate was conducted including and excluding MeFox. Concentrations (geometric mean; detection rate) of 5-methylTHF (37.5 nmol/L; 100%), UMFA (1.21 nmol/L; 99.9%), MeFox (1.53 nmol/L; 98.8%), and THF (1.01 nmol/L; 85.2%) were mostly detectable. 5-FormylTHF (3.6%) and 5,10-methenylTHF (4.4%) were rarely detected. The biggest contributor to serum total folate was 5-methylTHF (86.7%); UMFA (4.0%), non-methyl folate (4.7%), and MeFox (4.5%) contributed smaller amounts. Age was positively related to MeFox but showed a U-shaped pattern for other folates. We generally noted sex and race-ethnic biomarker differences and weak (Spearman r folates. All biomarkers showed significantly higher concentrations with recent folic acid-containing dietary supplement use. These first-time population data for serum folate forms generally show similar associations with demographic, physiologic, and lifestyle variables as serum total folate. Patterns observed for MeFox may suggest altered folate metabolism dependent on biological characteristics. PMID:25917925

  2. Synthesis and Application of Aurophilic Poly(Cysteine and Poly(Cysteine-Containing Copolymers

    Directory of Open Access Journals (Sweden)

    David Ulkoski

    2017-10-01

    Full Text Available The redox capacity, as well as the aurophilicity of the terminal thiol side groups, in poly(Cysteine lend a unique characteristic to this poly(amino acid or polypeptide. There are two major application fields for this polymer: (i biomedical applications in drug delivery and surface modification of biomedical devices and (ii as coating for electrodes to enhance their electrochemical sensitivity. The intended application determines the synthetic route for p(Cysteine. Polymers to be used in biomedical applications are typically polymerized from the cysteine N-carboxyanhydride by a ring-opening polymerization, where the thiol group needs to be protected during the polymerization. Advances in this methodology have led to conditions under which the polymerization progresses as living polymerization, which allows for a strict control of the molecular architecture, molecular weight and polydispersity and the formation of block copolymers, which eventually could display polyphilic properties. Poly(Cysteine used as electrode coating is typically polymerized onto the electrode by cyclic voltammetry, which actually produces a continuous, pinhole-free film on the electrode via the formation of covalent bonds between the amino group of Cysteine and the carbon of the electrode. This resulting coating is chemically very different from the well-defined poly(Cysteine obtained by ring-opening polymerizations. Based on the structure of cysteine a significant degree of cross-linking within the coating deposited by cyclic voltammetry can be assumed. This manuscript provides a detailed discussion of the ring-opening polymerization of cysteine, a brief consideration of the role of glutathione, a key cysteine-containing tripeptide, and examples for the utilization of poly(Cysteine and poly(Cysteine-containing copolymers, in both, the biomedical as well as electrochemical realm.

  3. Dietary intake and biological measurement of folate: A qualitative review of validation studies

    NARCIS (Netherlands)

    Park, Y.H.; Vollset, S.E.; Boonstra, A.; Chajes, V.; Ueland, P.M.; Slimani, N.

    2013-01-01

    Folate is a nutrient of major health significance, but its dietary intake assessment is particularly complex to quantify through traditional approaches. Attempts have been made to validate dietary instruments for assessing folate intake against circulating concentration biomarkers. However, this

  4. Maternal folate status in early pregnancy and child emotional and behavioral problems: The generation R study

    NARCIS (Netherlands)

    J.C.J. Steenweg-de Graaff (Jolien); S.J. Roza (Sabine); E.A.P. Steegers (Eric); A. Hofman (Albert); F.C. Verhulst (Frank); V.W.V. Jaddoe (Vincent); H.W. Tiemeier (Henning)

    2012-01-01

    textabstractBackground: Maternal prenatal folate status has been linked to neurodevelopmental disorders, but the association with child emotional and behavioral problems is unclear. Objectives: We assessed the association of maternal folate status during pregnancy with child emotional and behavioral

  5. Studies on folate binding and a radioassay for serum and whole-blood folate using goat milk as binding agent

    International Nuclear Information System (INIS)

    Piyasena, R.D.; Weerasekera, D.A.; Hettiaratchi, N.; Wikramanayake, T.W.

    1978-01-01

    Preparations of cow, goat, buffalo and human milk in addition to pig plasma were tested for folate binding properties. Of these, only pig plasma and goat milk showed sufficient binding to enable them to be used as binding agents in a radioassay for serum and whole-blood folate. The binding of folate by cow milk preparations in particular was found to be very poor. Goat milk was preferred to pig plasma as a binder for folate radioassay for reasons of convenience, economy and greater stability, and because pteroylglutamic acid (PGA) can be used both as tracer and standard. Where pig plasma is used with the inclusion of folate-free serum in the standard tubes, differences were observed between the standard and serum blanks which themselves varied from sample to sample. By contrast, with goat milk, all blank readings were normally 3% or less. Five out of eight samples of goat milk were seen to contain 'releasing factor' necessary to liberate folate from endogenous binder (FABP). Where present, the factor was found to be stable for at least three months when the partially purified milk was stored freeze dried at 4 0 C. Goat milk binder was found unable to distinguish between PGA and methyltetrahydrofolic acid (MTFA) at pH9.3. This enabled PGA rather than the more unstable MTFA to be used as tracer and standard. The assay employs a one-step incubation procedure at room temperature. It is sensitive to about 0.1 ng of PGA and is reproducible to less than 5% variation. The mean % recovery of inactive added folate was 101+-4%. (author)

  6. The Cysteine Protease–Cysteine Protease Inhibitor System Explored in Soybean Nodule Development

    Directory of Open Access Journals (Sweden)

    Marian Dorcas Quain

    2013-08-01

    Full Text Available Almost all protease families have been associated with plant development, particularly senescence, which is the final developmental stage of every organ before cell death. Proteolysis remobilizes and recycles nitrogen from senescent organs that is required, for example, seed development. Senescence-associated expression of proteases has recently been characterized using large-scale gene expression analysis seeking to identify and characterize senescence-related genes. Increasing activities of proteolytic enzymes, particularly cysteine proteases, are observed during the senescence of legume nodules, in which a symbiotic relationship between the host plant and bacteria (Rhizobia facilitate the fixation of atmospheric nitrogen. It is generally considered that cysteine proteases are compartmentalized to prevent uncontrolled proteolysis in nitrogen-fixing nodules. In addition, the activities of cysteine proteases are regulated by endogenous cysteine protease inhibitors called cystatins. These small proteins form reversible complexes with cysteine proteases, leading to inactivation. However, very little is currently known about how the cysteine protease-cysteine protease inhibitor (cystatin system is regulated during nodule development. Moreover, our current understanding of the expression and functions of proteases and protease inhibitors in nodules is fragmented. To address this issue, we have summarized the current knowledge and techniques used for studying proteases and their inhibitors including the application of “omics” tools, with a particular focus on changes in the cysteine protease-cystatin system during nodule development.

  7. Reduction of Guanosyl Radical by Cysteine and Cysteine-Glycine Studied by Time-Resolved CIDNP

    NARCIS (Netherlands)

    Morozova, O.B.; Kaptein, R.; Yurkovskaya, A.V.

    2012-01-01

    As a model for chemical DNA repair, reduction of guanosyl radicals in the reaction with cysteine or the dipeptide cysteine-glycine has been studied by time-resolved chemically induced dynamic nuclear polarization (CIDNP). Radicals were generated photochemically by pulsed laser irradiation of a

  8. Crystal Structure of Mammalian Cysteine dioxygenase: A Novel Mononuclear Iron Center for Cysteine Thiol Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Simmons,C.; Liu, Q.; Huang, Q.; Hao, Q.; Begley, T.; Karplus, P.; Stipanuk, M.

    2006-01-01

    Cysteine dioxygenase is a mononuclear iron-dependent enzyme responsible for the oxidation of cysteine with molecular oxygen to form cysteinesulfinate. This reaction commits cysteine to either catabolism to sulfate and pyruvate or to the taurine biosynthetic pathway. Cysteine dioxygenase is a member of the cupin superfamily of proteins. The crystal structure of recombinant rat cysteine dioxygenase has been determined to 1.5 Angstroms resolution, and these results confirm the canonical cupin {beta}-sandwich fold and the rare cysteinyl-tyrosine intramolecular crosslink (between Cys93 and Tyr157) seen in the recently reported murine cysteine dioxygenase structure. In contrast to the catalytically inactive mononuclear Ni(II) metallocenter present in the murine structure, crystallization of a catalytically competent preparation of rat cysteine dioxygenase revealed a novel tetrahedrally coordinated mononuclear iron center involving three histidines (His86, His88, and His140) and a water molecule. Attempts to acquire a structure with bound ligand using either co-crystallization or soaks with cysteine revealed the formation of a mixed disulfide involving Cys164 near the active site, which may explain previously observed substrate inhibition. This work provides a framework for understanding the molecular mechanisms involved in thiol dioxygenation and sets the stage for exploring the chemistry of both the novel mononuclear iron center and the catalytic role of the cysteinyl-tyrosine linkage.

  9. Reconstruction of Cysteine Biosynthesis Using Engineered Cysteine-Free and Methionine-Free Enzymes

    Science.gov (United States)

    Wang, Kendrick; Fujishima, Kosuke; Abe, Nozomi; Nakahigashi, Kenji; Endy, Drew; Rothschild, Lynn J.

    2016-01-01

    Ten of the proteinogenic amino acids can be generated abiotically while the remaining thirteen require biology for their synthesis. Paradoxically, the biosynthesis pathways observed in nature require enzymes that are made with the amino acids they produce. For example, Escherichia coli produces cysteine from serine via two enzymes that contain cysteine. Here, we substituted alternate amino acids for cysteine and also methionine, which is biosynthesized from cysteine, in serine acetyl transferase (CysE) and O-acetylserine sulfhydrylase (CysM). CysE function was rescued by cysteine-and-methionine-free enzymes and CysM function was rescued by cysteine-free enzymes. Structural modeling suggests that methionine stabilizes CysM and is present in the active site of CysM. Cysteine is not conserved among CysE and CysM protein orthologs, suggesting that cysteine is not functionally important for its own synthesis. Engineering biosynthetic enzymes that lack the amino acids being synthesized provides insights into the evolution of amino acid biosynthesis and pathways for bioengineering.

  10. Dietary folate deficiency blocks prostate cancer progression in the TRAMP model

    OpenAIRE

    Bistulfi, Gaia; Foster, Barbara A; Karasik, Ellen; Gillard, Bryan; Miecznikowski, Jeff; Dhiman, Vineet K; Smiraglia, Dominic J

    2011-01-01

    Dietary folate is essential in all tissues to maintain several metabolite pools and cellular proliferation. Prostate cells, due to specific metabolic characteristics, have increased folate demand to support proliferation and prevent genetic and epigenetic damage. Although several studies found that dietary folate interventions can affect colon cancer biology in rodent models, impact on prostate is unknown. The purpose of this study was to determine if dietary folate manipulation, possibly bei...

  11. Folate status and concentrations of serum folate forms in the US population: National Health and Nutrition Examination Survey 2011-2.

    Science.gov (United States)

    Pfeiffer, Christine M; Sternberg, Maya R; Fazili, Zia; Lacher, David A; Zhang, Mindy; Johnson, Clifford L; Hamner, Heather C; Bailey, Regan L; Rader, Jeanne I; Yamini, Sedigheh; Berry, R J; Yetley, Elizabeth A

    2015-06-28

    Serum and erythrocyte (RBC) total folate are indicators of folate status. No nationally representative population data exist for folate forms. We measured the serum folate forms (5-methyltetrahydrofolate (5-methylTHF), unmetabolised folic acid (UMFA), non-methyl folate (sum of tetrahydrofolate (THF), 5-formyltetrahydrofolate (5-formylTHF), 5,10-methenyltetrahydrofolate (5,10-methenylTHF)) and MeFox (5-methylTHF oxidation product)) by HPLC-MS/MS and RBC total folate by microbiologic assay in US population ≥ 1 year (n approximately 7500) participating in the National Health and Nutrition Examination Survey 2011-2. Data analysis for serum total folate was conducted including and excluding MeFox. Concentrations (geometric mean; detection rate) of 5-methylTHF (37·5 nmol/l; 100 %), UMFA (1·21 nmol/l; 99·9 %), MeFox (1·53 nmol/l; 98·8 %), and THF (1·01 nmol/l; 85·2 %) were mostly detectable. 5-FormylTHF (3·6 %) and 5,10-methenylTHF (4·4 %) were rarely detected. The biggest contributor to serum total folate was 5-methylTHF (86·7 %); UMFA (4·0 %), non-methyl folate (4·7 %) and MeFox (4·5 %) contributed smaller amounts. Age was positively related to MeFox, but showed a U-shaped pattern for other folates. We generally noted sex and race/ethnic biomarker differences and weak (Spearman's rfolates. All biomarkers showed significantly higher concentrations with recent folic acid-containing dietary supplement use. These first-time population data for serum folate forms generally show similar associations with demographic, physiological and lifestyle variables as serum total folate. Patterns observed for MeFox may suggest altered folate metabolism dependent on biological characteristics.

  12. Cysteine Biosynthesis Controls Serratia marcescens Phospholipase Activity.

    Science.gov (United States)

    Anderson, Mark T; Mitchell, Lindsay A; Mobley, Harry L T

    2017-08-15

    Serratia marcescens causes health care-associated opportunistic infections that can be difficult to treat due to a high incidence of antibiotic resistance. One of the many secreted proteins of S. marcescens is the PhlA phospholipase enzyme. Genes involved in the production and secretion of PhlA were identified by screening a transposon insertion library for phospholipase-deficient mutants on phosphatidylcholine-containing medium. Mutations were identified in four genes ( cyaA , crp , fliJ , and fliP ) that are involved in the flagellum-dependent PhlA secretion pathway. An additional phospholipase-deficient isolate harbored a transposon insertion in the cysE gene encoding a predicted serine O -acetyltransferase required for cysteine biosynthesis. The cysE requirement for extracellular phospholipase activity was confirmed using a fluorogenic phospholipase substrate. Phospholipase activity was restored to the cysE mutant by the addition of exogenous l-cysteine or O -acetylserine to the culture medium and by genetic complementation. Additionally, phlA transcript levels were decreased 6-fold in bacteria lacking cysE and were restored with added cysteine, indicating a role for cysteine-dependent transcriptional regulation of S. marcescens phospholipase activity. S. marcescens cysE mutants also exhibited a defect in swarming motility that was correlated with reduced levels of flhD and fliA flagellar regulator gene transcription. Together, these findings suggest a model in which cysteine is required for the regulation of both extracellular phospholipase activity and surface motility in S. marcescens IMPORTANCE Serratia marcescens is known to secrete multiple extracellular enzymes, but PhlA is unusual in that this protein is thought to be exported by the flagellar transport apparatus. In this study, we demonstrate that both extracellular phospholipase activity and flagellar function are dependent on the cysteine biosynthesis pathway. Furthermore, a disruption of cysteine

  13. Controlles modulation of folate polyglutamyl tail length by metabolic engineering of Lactococcus lactis

    NARCIS (Netherlands)

    Sybesma, W.F.H.; Born, van den E.; Starrenburg, M.; Mierau, I.; Kleerebezem, M.; Vos, de W.M.; Hugenholtz, J.

    2003-01-01

    The dairy starter bacterium Lactococcus lactis is able to synthesize folate and accumulates >90% of the produced folate intracellularly, predominantly in the polyglutamyl form. Approximately 10% of the produced folate is released into the environment. Overexpression of folC in L. lactis led to an

  14. Exploring folate diversity in wild and primitive potatoes for modern crop improvement

    Science.gov (United States)

    Malnutrition is one of the world’s largest health concerns. Folate (a.k.a. vitamin B9) is essential in the human diet and without adequate folate intake several serious health concerns such as congenital birth defects and an increased risk of stroke and heart disease can occur. Most people’s folate ...

  15. Mechanistic insights of intestinal absorption and renal conservation of folate in chronic alcoholism.

    Science.gov (United States)

    Wani, Nissar Ahmad; Thakur, Shilpa; Najar, Rauf Ahmad; Nada, Ritambhara; Khanduja, Krishan Lal; Kaur, Jyotdeep

    2013-03-01

    Folate mediated one-carbon metabolism is of fundamental importance for various cellular processes, including DNA synthesis and methylation of biological molecules. Due to the exogenous requirement of folate in mammals, there exists a well developed epithelial folate transport system for regulation of normal folate homeostasis. The intestinal and renal folate uptake is tightly and diversely regulated and disturbances in folate homeostasis like in alcoholism have pathological consequences. The study was sought to delineate the regulatory mechanism of folate uptake in intestine and reabsorption in renal tubular cells that could evaluate insights of malabsorption during alcoholism. The folate transporters PCFT and RFC were found to be associated with lipid rafts of membrane surfaces in intestine and kidney. Importantly, the observed lower intestinal and renal folate uptake was associated with decreased levels of folate transporter viz. PCFT and RFC in lipid rafts of intestinal and renal membrane surfaces. The decreased association of folate transporters in lipid rafts was associated with decreased protein and mRNA levels. In addition, immunohistochemical studies showed that alcoholic conditions deranged that localization of PCFT and RFC. These findings could explain the possible mechanistic insights that may result in folate malabsorption during alcoholism. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Cobalamin C Deficiency Shows a Rapidly Progressing Maculopathy With Severe Photoreceptor and Ganglion Cell Loss

    Science.gov (United States)

    Bonafede, Lucas; Ficicioglu, Can H.; Serrano, Leona; Han, Grace; Morgan, Jessica I. W.; Mills, Monte D.; Forbes, Brian J.; Davidson, Stefanie L.; Binenbaum, Gil; Kaplan, Paige B.; Nichols, Charles W.; Verloo, Patrick; Leroy, Bart P.; Maguire, Albert M.; Aleman, Tomas S.

    2015-01-01

    Purpose To describe in detail the retinal structure and function of a group of patients with cobalamin C (cblC) disease. Methods Patients (n = 11, age 4 months to 15 years) with cblC disease (9/11, early onset) diagnosed by newborn screening underwent complete ophthalmic examinations, fundus photography, near-infrared reflectance imaging, and spectral-domain optical coherence tomography (SD-OCT). Electroretinograms (ERGs) were performed in a subset of patients. Results Patients carried homozygous or compound heterozygote mutations in the methylmalonic aciduria and homocystinuria type C (MMACHC) gene. Late-onset patients had a normal exam. All early-onset patients showed a maculopathy; older subjects had a retina-wide degeneration (n = 4; >7 years of age). In general, retinal changes were first observed before 1 year of age and progressed within months to a well-established maculopathy. Pseudocolobomas were documented in three patients. Measurable visual acuities ranged from 20/200 to 20/540. Nystagmus was present in 8/11 patients; 5/6 patients had normal ERGs; 1/6 had reduced rod-mediated responses. Spectral-domain OCT showed macular thinning, with severe ganglion cell layer (GCL) and outer nuclear layer (ONL) loss. Inner retinal thickening was observed in areas of total GCL/ONL loss. A normal lamination pattern in the peripapillary nasal retina was often seen despite severe central and/or retina-wide disease. Conclusions Patients with early-onset cblC and MMACHC mutations showed an early-onset, unusually fast-progressing maculopathy with severe central ONL and GCL loss. An abnormally thickened inner retina supports a remodeling response to both photoreceptor and ganglion cell degeneration and/or an interference with normal development in early-onset cblC. PMID:26658511

  17. Hepatic Effects of Pharmacological Doses of Hydroxy-Cobalamin[c-lactam] in Mice.

    Directory of Open Access Journals (Sweden)

    Patrizia Haegler

    Full Text Available The vitamin B12 analog hydroxy-cobalamin[c-lactam] (HCCL impairs hepatic mitochondrial protein synthesis and function of the electron transport chain in rats. We aimed to establish an in vivo model for mitochondrial dysfunction in mice, which could be used to investigate hepatotoxicity of mitochondrial toxicants. In a first step, we performed a dose-finding study in mice treated with HCCL 0.4 mg/kg and 4 mg/kg i.p. for two to four weeks. The plasma methylmalonate concentration was strongly increased at 4 mg/kg starting at three weeks of treatment. We subsequently treated mice daily with 4 mg/kg HCCL i.p. for three weeks and characterized liver function and histology as well as liver mitochondrial function. We found an increase in liver weight in HCCL-treated mice, which was paralleled by hepatocellular accumulation of triglycerides. In liver homogenate of HCCL-treated mice, the complex I activity of the electron transport chain was reduced, most likely explaining hepatocellular triglyceride accumulation. The activity of CPT1 was not affected by methylmalonyl-CoA in isolated liver mitochondria. Despite impaired complex I activity, mitochondrial superoxide anion production was not increased and the hepatocellular glutathione (GSH pool was maintained. Finally, the mitochondrial DNA content was not altered with HCCL treatment. In conclusion, treatment of mice with HCCL is associated with increased liver weight explained by hepatocellular triglyceride accumulation. Hepatocellular fat accumulation is most likely a consequence of impaired activity of the mitochondrial electron transport chain. The impairment of complex I activity is not strong enough to result in ROS accumulation and reduction of the GSH stores.

  18. π-Clamp-mediated cysteine conjugation

    Science.gov (United States)

    Zhang, Chi; Welborn, Matthew; Zhu, Tianyu; Yang, Nicole J.; Santos, Michael S.; van Voorhis, Troy; Pentelute, Bradley L.

    2016-02-01

    Site-selective functionalization of complex molecules is one of the most significant challenges in chemistry. Typically, protecting groups or catalysts must be used to enable the selective modification of one site among many that are similarly reactive, and general strategies that selectively tune the local chemical environment around a target site are rare. Here, we show a four-amino-acid sequence (Phe-Cys-Pro-Phe), which we call the ‘π-clamp’, that tunes the reactivity of its cysteine thiol for site-selective conjugation with perfluoroaromatic reagents. We use the π-clamp to selectively modify one cysteine site in proteins containing multiple endogenous cysteine residues. These examples include antibodies and cysteine-based enzymes that would be difficult to modify selectively using standard cysteine-based methods. Antibodies modified using the π-clamp retained binding affinity to their targets, enabling the synthesis of site-specific antibody-drug conjugates for selective killing of HER2-positive breast cancer cells. The π-clamp is an unexpected approach to mediate site-selective chemistry and provides new avenues to modify biomolecules for research and therapeutics.

  19. Detergent activation of the binding protein in the folate radioassay

    International Nuclear Information System (INIS)

    Hansen, S.I.; Holm, J.; Lyngbye, J.

    1982-01-01

    A minor cow's whey protein associated with β-lactoglobulin is used as binding protein in the competitive radioassay for serum and erythrocyte folate. Seeking to optimize the assay, we tested the performance of binder solutions of increasing purity. The folate binding protein was isolated from cow's whey by means of CM-Sepharose CL-6B cation-exchange chromatography, and further purified on a methotrexate-AH-Sepharose 4B affinity matrix. In contrast to β-lactoglobulin, the purified protein did not bind folate unless the detergents cetyltrimethylammonium (10 mmol/Ll) or Triton X-100 (1 g/L) were present. Such detergent activation was not needed in the presence of serum. There seems to be a striking analogy between these phenomena and the well-known reactivation of certain purified membrane-derived enzymes by surfactants

  20. Xenopus reduced folate carrier regulates neural crest development epigenetically.

    Directory of Open Access Journals (Sweden)

    Jiejing Li

    Full Text Available Folic acid deficiency during pregnancy causes birth neurocristopathic malformations resulting from aberrant development of neural crest cells. The Reduced folate carrier (RFC is a membrane-bound receptor for facilitating transfer of reduced folate into the cells. RFC knockout mice are embryonic lethal and develop multiple malformations, including neurocristopathies. Here we show that XRFC is specifically expressed in neural crest tissues in Xenopus embryos and knockdown of XRFC by specific morpholino results in severe neurocristopathies. Inhibition of RFC blocked the expression of a series of neural crest marker genes while overexpression of RFC or injection of 5-methyltetrahydrofolate expanded the neural crest territories. In animal cap assays, knockdown of RFC dramatically reduced the mono- and trimethyl-Histone3-K4 levels and co-injection of the lysine methyltransferase hMLL1 largely rescued the XRFC morpholino phenotype. Our data revealed that the RFC mediated folate metabolic pathway likely potentiates neural crest gene expression through epigenetic modifications.

  1. The association between atopy and factors influencing folate metabolism: is low folate status causally related to the development of atopy?

    DEFF Research Database (Denmark)

    Husemoen, LL; Toft, U.; Fenger, Mogens

    2006-01-01

    BACKGROUND: Deficiency of folate has been associated with several disorders characterized by enhanced activation of the cellular immune system (non-allergic th1 type immune response). Whether folate status is also associated with atopic disease (allergic th2 type immune response) is unknown. We....../CT individuals [odds ratio 1.76, 95% confidence interval (95% CI) 1.19-2.60]. Additionally, gene-diet interaction effects were identified. Dietary markers were negatively associated with risk of atopy in persons with the TT genotype. Total homocysteine was not related to atopy (odds ratio per 5 mumol/l = 1.......12, 95% CI 0.98-1.29). CONCLUSIONS: The results suggest that an impaired folate metabolism may be causally related to the development of atopy....

  2. Folate bioavailability from foods rich in folates assessed in a short term human study using stable isotope dilution assays.

    Science.gov (United States)

    Mönch, Sabine; Netzel, Michael; Netzel, Gabriele; Ott, Undine; Frank, Thomas; Rychlik, Michael

    2015-01-01

    Different sources of folate may have different bioavailability and hence may impact the standard definition of folate equivalents. In order to examine this, a short term human study was undertaken to evaluate the relative native folate bioavailabilities from spinach, Camembert cheese and wheat germs compared to pteroylmonoglutamic acid as the reference dose. The study had a single-centre, randomised, four-treatment, four-period, four-sequence, cross-over design, i.e. the four (food) items to be tested (referred to as treatments) were administered in sequences according to the Latin square, so that each experimental treatment occurred only once within each sequence and once within each study period. Each of the 24 subjects received the four experimental items separated by a 14-day equilibrium phase and received a pteroylmonoglutamic acid supplement for 14 days before the first testing and between the testings for saturation of body pools. Folates in test foods, plasma and urine samples were determined by stable isotope dilution assays, and in urine and plasma, the concentrations of 5-methyltetrahydrofolate were evaluated. Standard non-compartmental methods were applied to determine the biokinetic parameters C(max), t(max) and AUC from baseline corrected 5-methyltetrahydrofolate concentrations within the interval from 0 to 12 hours. The variability of AUC and C(max) was moderate for spinach and oral solution of pteroylmonoglutamic acid but high for Camembert cheese and very high for wheat germs. The median t(max) was lowest for spinach, though t(max) showed a high variability among all treatments. When comparing the ratio estimates of AUC and C(max) for the different test foods, highest bioavailability was found for spinach followed by that for wheat germs and Camembert cheese. The results underline the dependence of folate bioavailability on the type of food ingested. Therefore, the general assumption of 50% bioavailability as the rationale behind the definition of

  3. Relative bioavailability of folate from the traditional food plant Moringa oleifera L. as evaluated in a rat model

    OpenAIRE

    Saini, R. K.; Manoj, P.; Shetty, N. P.; Srinivasan, K.; Giridhar, P.

    2015-01-01

    Moringa oleifera is an affordable and rich source of dietary folate. Quantification of folate by HPLC showed that 5-formyl-5,6,7,8-tetrahydrofolic acid (502.1 μg/100 g DW) and 5,6,7,8-tetrahydrofolic acid (223.9 μg/100 g DW) as the most dominant forms of folate in M. oleifera leaves. The bioavailability of folate and the effects of folate depletion and repletion on biochemical and molecular markers of folate status were investigated in Wistar rats. Folate deficiency was induced by keeping the...

  4. High plasma folate is negatively associated with leukocyte telomere length in Framingham Offspring cohort.

    Science.gov (United States)

    Paul, Ligi; Jacques, Paul F; Aviv, Abraham; Vasan, Ramachandran S; D'Agostino, Ralph B; Levy, Daniel; Selhub, Jacob

    2015-03-01

    Shortening of telomeres, the protective structures at the ends of eukaryotic chromosomes, is associated with age-related pathologies. Telomere length is influenced by DNA integrity and DNA and histone methylation. Folate plays a role in providing precursors for nucleotides and methyl groups for methylation reactions and has the potential to influence telomere length. We determined the association between leukocyte telomere length and long-term plasma folate status (mean of 4 years) in Framingham Offspring Study (n = 1,044, females = 52.1 %, mean age 59 years) using data from samples collected before and after folic acid fortification. Leukocyte telomere length was determined by Southern analysis and fasting plasma folate concentration using microbiological assay. There was no significant positive association between long-term plasma folate and leukocyte telomere length among the Framingham Offspring Study participants perhaps due to their adequate folate status. While the leukocyte telomere length in the second quintile of plasma folate was longer than that in the first quintile, the difference was not statistically significant. The leukocyte telomere length of the individuals in the fifth quintile of plasma folate was shorter than that of those in the second quintile by 180 bp (P folate concentrations in the upper four quintiles of plasma folate (P for trend = 0.001). Multivitamin use was associated with shorter telomeres in this cohort (P = 0.015). High plasma folate status possibly resulting from high folic acid intake may interfere with the role of folate in maintaining telomere integrity.

  5. Effects of Polyethylene Glycol Spacer Length and Ligand Density on Folate Receptor Targeting of Liposomal Doxorubicin In Vitro

    Directory of Open Access Journals (Sweden)

    Kumi Kawano

    2011-01-01

    Full Text Available The folate receptor is an attractive target for selective tumor delivery of liposomal doxorubicin (DXR because it is abundantly expressed in a large percentage of tumors. This study examined the effect of polyethylene glycol (PEG spacer length and folate ligand density on the targeting ability of folate-modified liposomes. Liposomes were modified with folate-derivatized PEG-distearoylphosphatidylethanolamine with PEG molecular weights of 2000, 3400, or 5000. The association of DXR-loaded liposomes with KB cells, which overexpress the folate receptor, was evaluated by flow cytometry at various ratios of folate modification. A low ratio of folate modification with a sufficiently long PEG chain showed the highest folate receptor-mediated association with the cells, but did not show the highest in vitro cytotoxicity. DXR release from folate-modified liposomes in endosomes might be different. These findings will be useful for designing folate receptor-targeting carriers.

  6. Cysteine proteases as potential antigens in antiparasitic DNA vaccines

    DEFF Research Database (Denmark)

    Jørgensen, Louise von Gersdorff; Buchmann, Kurt

    2011-01-01

    En litteraturgennemgang af muligheder for at bruge cystein proteaser som antigener i antiparasitære vacciner.......En litteraturgennemgang af muligheder for at bruge cystein proteaser som antigener i antiparasitære vacciner....

  7. Evaluation of iron and folate deficiencies as possible causes of ...

    African Journals Online (AJOL)

    Ten (10ml) of venous blood was drawn from each subject and distributed into sodium- EDTA specimen bottle (5ml) for estimation of full blood count within 2 hours of collection and plain disposable plastic tubes (5ml) for the estimation of serum ferritin, serum homocysteine and serum folate in both study and control groups.

  8. Bioavailability of folate from processed spinach in humans

    NARCIS (Netherlands)

    Castenmiller, J.J.M.; Poll, van de C.J.; West, C.E.; Brouwer, I.A.; Thomas, C.M.G.; Dusseldorp, van M.

    2000-01-01

    The effect of the food matrix and dietary fibre on the bioavailability of folate is not known. In a controlled, 3-week dietary intervention study, 28 men and 42 women were divided into six groups to receive either a control diet (n = 10), or the control diet plus 20 g/MJ per day (n = 12 per group)

  9. Research goals for folate and related B vitamin in Europe

    NARCIS (Netherlands)

    Finglas, P.M.; Meer, K. de; Molloy, A.; Verhoef, P.; Pietrzik, K.; Powers, H.J.; Straeten, D. van der; Jägerstad, M.; Varela-Moreiras, G.; Vliet, T. van; Havenaar, R.; Buttriss, J.; Wright, A.J.A.

    2006-01-01

    In the past decade, the understanding of folate bioavailability, metabolism and related health issues has increased, but several problems remain, including the difficulty of delivering the available knowledge to the populations at risk. Owing to the low compliance of taking folic acid supplements,

  10. Synthesis and characterization of folate-poly(ethylene glycol ...

    African Journals Online (AJOL)

    polyethylenimine as a non-viral carrier for tumor-targeted gene delivery. ... It was concluded that FA-PEG-CHI-g-PEI, which has improved transfection efficiency and FRs specificity in vitro and in vivo, may be useful in gene therapy. Key words: Folate ...

  11. EFFECT OF DIETARY FOLATE DEFICIENCY ON ARSENIC GENOTOXICITY IN MICE

    Science.gov (United States)

    Arsenic, a human carcinogen found in drinking water supplies throughout the world, is clastogenic in human and rodent cells. An estimated ten percent of Americans are deficient in folate, a methyl donor necessary for normal nucleotide metabolism, DNA synthesis, and DNA methylatio...

  12. Oxidative-stress-mediated teratogenesis and the role of folate

    NARCIS (Netherlands)

    Tran, Y.H.; Bergman, J.; Bakker, M.; Groen, H.; Wilffert, B.

    2016-01-01

    Background: Oxidative stress (OS) is one of the underlying teratogenic mechanisms of medical drugs. Folate is indirectly involved in OS because of its role in the methylation steps in the detoxification of xenobiotics and in the repair of OS-induced DNA damage. Our study was to explore the

  13. Association of anaemia with micronutrient (iron, folate and Vitamin ...

    African Journals Online (AJOL)

    After informed verbal consent from the guardian or parent was obtained, information on demographic and clinical characteristics was collected from the parent or guardian. The following laboratory tests on blood were done on all subjects: full blood count; serum iron; serum transferrin; serum folate; and active serum vitamin ...

  14. Updated folate data in the Dutch Food Composition Database and implications for intake estimates

    Directory of Open Access Journals (Sweden)

    Susanne Westenbrink

    2012-04-01

    Full Text Available Background and objective: Nutrient values are influenced by the analytical method used. Food folate measured by high performance liquid chromatography (HPLC or by microbiological assay (MA yield different results, with in general higher results from MA than from HPLC. This leads to the question of how to deal with different analytical methods in compiling standardised and internationally comparable food composition databases? A recent inventory on folate in European food composition databases indicated that currently MA is more widely used than HPCL. Since older Dutch values are produced by HPLC and newer values by MA, analytical methods and procedures for compiling folate data in the Dutch Food Composition Database (NEVO were reconsidered and folate values were updated. This article describes the impact of this revision of folate values in the NEVO database as well as the expected impact on the folate intake assessment in the Dutch National Food Consumption Survey (DNFCS. Design: The folate values were revised by replacing HPLC with MA values from recent Dutch analyses. Previously MA folate values taken from foreign food composition tables had been recalculated to the HPLC level, assuming a 27% lower value from HPLC analyses. These recalculated values were replaced by the original MA values. Dutch HPLC and MA values were compared to each other. Folate intake was assessed for a subgroup within the DNFCS to estimate the impact of the update. Results: In the updated NEVO database nearly all folate values were produced by MA or derived from MA values which resulted in an average increase of 24%. The median habitual folate intake in young children was increased by 11–15% using the updated folate values. Conclusion: The current approach for folate in NEVO resulted in more transparency in data production and documentation and higher comparability among European databases. Results of food consumption surveys are expected to show higher folate intakes

  15. 21 CFR 184.1271 - L-Cysteine.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true L-Cysteine. 184.1271 Section 184.1271 Food and... Substances Affirmed as GRAS § 184.1271 L-Cysteine. (a) L-Cysteine is the chemical L-2-amino-3... of total L-cysteine per 100 parts of flour in dough as a dough strengthener as defined in § 170.3(o...

  16. 21 CFR 184.1272 - L-Cysteine monohydrochloride.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true L-Cysteine monohydrochloride. 184.1272 Section 184... Listing of Specific Substances Affirmed as GRAS § 184.1272 L-Cysteine monohydrochloride. (a) L-Cysteine... ingredient is used to supply up to 0.009 part of total L-cysteine per 100 parts of flour in dough as a dough...

  17. Glycine and Folate Ameliorate Models of Congenital Sideroblastic Anemia.

    Directory of Open Access Journals (Sweden)

    J Pedro Fernández-Murray

    2016-01-01

    Full Text Available Sideroblastic anemias are acquired or inherited anemias that result in a decreased ability to synthesize hemoglobin in red blood cells and result in the presence of iron deposits in the mitochondria of red blood cell precursors. A common subtype of congenital sideroblastic anemia is due to autosomal recessive mutations in the SLC25A38 gene. The current treatment for SLC25A38 congenital sideroblastic anemia is chronic blood transfusion coupled with iron chelation. The function of SLC25A38 is not known. Here we report that the SLC25A38 protein, and its yeast homolog Hem25, are mitochondrial glycine transporters required for the initiation of heme synthesis. To do so, we took advantage of the fact that mitochondrial glycine has several roles beyond the synthesis of heme, including the synthesis of folate derivatives through the glycine cleavage system. The data were consistent with Hem25 not being the sole mitochondrial glycine importer, and we identify a second SLC25 family member Ymc1, as a potential secondary mitochondrial glycine importer. Based on these findings, we observed that high levels of exogenous glycine, or 5-aminolevulinic acid (5-Ala a metabolite downstream of Hem25 in heme biosynthetic pathway, were able to restore heme levels to normal in yeast cells lacking Hem25 function. While neither glycine nor 5-Ala could ameliorate SLC25A38 congenital sideroblastic anemia in a zebrafish model, we determined that the addition of folate with glycine was able to restore hemoglobin levels. This difference is likely due to the fact that yeast can synthesize folate, whereas in zebrafish folate is an essential vitamin that must be obtained exogenously. Given the tolerability of glycine and folate in humans, this study points to a potential novel treatment for SLC25A38 congenital sideroblastic anemia.

  18. Endocytosis of GPI-linked membrane folate receptor-alpha.

    Science.gov (United States)

    Rijnboutt, S; Jansen, G; Posthuma, G; Hynes, J B; Schornagel, J H; Strous, G J

    1996-01-01

    GPI-linked membrane folate receptors (MFRs) have been implicated in the receptor-mediated uptake of reduced folate cofactors and folate-based chemotherapeutic drugs. We have studied the biosynthetic transport to and internalization of MFR isoform alpha in KB-cells. MFR-alpha was synthesized as a 32-kD protein and converted in a maturely glycosylated 36-38-kD protein 1 h after synthesis. 32-kD MFR-alpha was completely soluble in Triton X-100 at 0 degree C. In contrast, only 33% of the 36-38-kD species could be solubilized at these conditions whereas complete solubilization was obtained in Triton X-100 at 37 degrees C or in the presence of saponin at 0 degree C. Similar solubilization characteristics were found when MFR-alpha at the plasma membrane was labeled with a crosslinkable 125I-labeled photoaffinity-analog of folic acid as a ligand. Triton X-100-insoluble membrane domains containing MFR-alpha could be separated from soluble MFR-alpha on sucrose flotation gradients. Only Triton X-100 soluble MFR-alpha was internalized from the plasma membrane. The reduced-folate-carrier, an integral membrane protein capable of translocating (anti-)folates across membranes, was completely excluded from the Triton X-100-resistant membrane domains. Internalized MFR-alpha recycled slowly to the cell surface during which it remained soluble in Triton X-100 at 0 degree C. Using immunoelectron microscopy, we found MFR-alpha along the entire endocytic pathway: in clathrin-coated buds and vesicles, and in small and large endosomal vacuoles. In conclusion, our data indicate that a large fraction, if not all, of internalizing MFR-alpha bypasses caveolae.

  19. Enhancing pterin and para-aminobenzoate content is not sufficient to successfully biofortify potato tubers and Arabidopsis thaliana plants with folate

    NARCIS (Netherlands)

    Blancquaert, D.; Storozhenko, S.; Daele, W.; Stove, C.; Visser, R.G.F.; Lambert, W.; Straeten, van der D.

    2013-01-01

    Folates are important cofactors in one-carbon metabolism in all living organisms. Since only plants and micro- organisms are capable of biosynthesizing folates, humans depend entirely on their diet as a folate source. Given the low folate content of several staple crop products, folate deficiency

  20. Temperature effects on separation of Gd3+ from Gd-DTPA-folate using nanofiltration method

    Science.gov (United States)

    Rahayu, I.; Indraneli, R. P.; Yuliyati, Y. B.; Anggraeni, A.; Soedjanaatmadja, U. M. S.; Bahti, H. H.

    2018-05-01

    MRI is one of the best techniques in medical diagnostics. Contrast agents are used to improve the visual of organs that are difficult to distinguish through MRI. Gd-DTPA-folate is one of the specific contrast agents against cancer diagnosis, because it has a high affinity to folate receptors. In the complexing Gd-DTPA-folate, does not rule out the complexity step runs imperfectly, so there is still Gd3+ in the Gd-DTPA-folate complex. The separation of Gd3+ from the Gd-DTPA-folate complex is important to eliminate toxic effects on the contrast agent. This study aims to determine the effect of temperature on the separation of Gd-DTPA-folate from Gd3+ with nanofiltration. The method are preparation Gd-DTPA-folate from GdCl3.6H2O and DTPA-folate by reflux method, then separated Gd-DTPA-folate complex from Gd3+ with nanofiltration at variation temperature (40, 41, 42, 43, 44oC ). Then, the values of flux and rejection coefficients were analyzed. The results showed that the optimum temperature for the separation of Gd3+ from Gd-DTPA-folate was achieved at 42.6°C with the rejection coefficient of 24% and the permeate flux of 403 L.m-2.h-1.

  1. L-Cysteine Metabolism and Fermentation in Microorganisms.

    Science.gov (United States)

    Takagi, Hiroshi; Ohtsu, Iwao

    L-Cysteine is an important amino acid both biologically and commercially. Although most amino acids are industrially produced by microbial fermentation, L-cysteine has been mainly produced by protein hydrolysis. Due to environmental and safety problems, synthetic or biotechnological products have been preferred in the market. Here, we reviewed L-cysteine metabolism, including biosynthesis, degradation, and transport, and biotechnological production (including both enzymatic and fermentation processes) of L-cysteine. The metabolic regulation of L-cysteine including novel sulfur metabolic pathways found in microorganisms is also discussed. Recent advancement in biochemical studies, genome sequencing, structural biology, and metabolome analysis has enabled us to use various approaches to achieve direct fermentation of L-cysteine from glucose. For example, worldwide companies began to supply L-cysteine and its derivatives produced by bacterial fermentation. These companies successfully optimized the original metabolism of their private strains. Basically, a combination of three factors should be required for improving L-cysteine fermentation: that is, (1) enhancing biosynthesis: overexpression of the altered cysE gene encoding feedback inhibition-insensitive L-serine O-acetyltransferase (SAT), (2) weakening degradation: knockout of the genes encoding L-cysteine desulfhydrases, and (3) exploiting export system: overexpression of the gene involved in L-cysteine transport. Moreover, we found that "thiosulfate" is much more effective sulfur source than commonly used "sulfate" for L-cysteine production in Escherichia coli, because thiosulfate is advantageous for saving consumption of NADPH and relating energy molecules.

  2. Folinic acid treatment for schizophrenia associated with folate receptor autoantibodies.

    Science.gov (United States)

    Ramaekers, V T; Thöny, B; Sequeira, J M; Ansseau, M; Philippe, P; Boemer, F; Bours, V; Quadros, E V

    2014-12-01

    Auto-antibodies against folate receptor alpha (FRα) at the choroid plexus that block N(5)-methyltetrahydrofolate (MTHF) transfer to the brain were identified in catatonic schizophrenia. Acoustic hallucinations disappeared following folinic acid treatment. Folate transport to the CNS prevents homocysteine accumulation and delivers one-carbon units for methyl-transfer reactions and synthesis of purines. The guanosine derivative tetrahydrobiopterin acts as common co-factor for the enzymes producing dopamine, serotonin and nitric oxide. Our study selected patients with schizophrenia unresponsive to conventional treatment. Serum from these patients with normal plasma homocysteine, folate and vitamin B12 was tested for FR autoantibodies of the blocking type on serial samples each week. Spinal fluid was analyzed for MTHF and the metabolites of pterins, dopamine and serotonin. The clinical response to folinic acid treatment was evaluated. Fifteen of 18 patients (83.3%) had positive serum FR auto-antibodies compared to only 1 in 30 controls (3.3%) (χ(2)=21.6; pfolate flux to the CNS, which explained low CSF folate values in 6 and normal values in 7 patients. The mean±SD for CSF MTHF was diminished compared to previously established controls (t-test: 3.90; p=0.0002). A positive linear correlation existed between CSF MTHF and biopterin levels. CSF dopamine and serotonin metabolites were low or in the lower normal range. Administration of folinic acid (0.3-1mg/kg/day) to 7 participating patients during at least six months resulted in clinical improvement. Assessment of FR auto-antibodies in serum is recommended for schizophrenic patients. Clinical negative or positive symptoms are speculated to be influenced by the level and evolution of FRα antibody titers which determine folate flux to the brain with up- or down-regulation of brain folate intermediates linked to metabolic processes affecting homocysteine levels, synthesis of tetrahydrobiopterin and neurotransmitters

  3. [Plant signaling peptides. Cysteine-rich peptides].

    Science.gov (United States)

    Ostrowski, Maciej; Kowalczyk, Stanisław

    2015-01-01

    Recent bioinformatic and genetic analyses of several model plant genomes have revealed the existence of a highly abundant group of signaling peptides that are defined as cysteine-rich peptides (CRPs). CRPs are usually in size between 50 and 90 amino acid residues, they are positively charged, and they contain 4-16 cysteine residues that are important for the correct conformational folding. Despite the structural differences among CRP classes, members from each class have striking similarities in their molecular properties and function. The present review presents the recent progress in research on signaling peptides from several families including: EPF/EPFL, SP11/SCR, PrsS, RALF, LURE, and some other peptides belonging to CRP group. There is convincing evidence indicating multiple roles for these CRPs as signaling molecules during the plant life cycle, ranging from stomata development and patterning, self-incompatibility, pollen tube growth and guidance, reproductive processes, and nodule formation.

  4. Trans and cis effects of axial fluoroalkyl ligands in vitamin B12 analogues: relationship between alkyl- and fluoroalkyl-cobalamins.

    Science.gov (United States)

    Randaccio, Lucio; Brancatelli, Giovanna; Demitri, Nicola; Dreos, Renata; Hickey, Neal; Siega, Patrizia; Geremia, Silvano

    2013-12-02

    CF2HCbl, CF3Cbl , and CF3CH2Cbl have been synthesized and characterized in solution by (1)H NMR and UV-vis spectroscopy, and their X-ray crystal structures have been determined using synchrotron radiation. The structure of CF3CH2Cbl is reported for the first time, whereas those of CF2HCbl and CF3Cbl are re-examined to obtain more precise structural data. Comparison of the structural data obtained with the alkylcobalamin analogues, MeCbl and EtCbl, indicates that the Co-C and Co-NB3 bond lengths are shorter in the fluoroalkylcobalamins. The structural data of the fluoroalkylcobalamins previously reported in the literature had been conflicting in this regard. Thus, a much less dramatic shortening of the two axial bonds was found for CF3Cbl, whereas in the case of CF2HCbl, the Co-NB3 bond length is shorter than in MeCbl. Direct comparison of the structures of CF3CH2Cbl and EtCbl indicates a large distortion of the axial fragment in the former case that can be attributed to steric effects. A number of previously reported correlations of the effect of the β-ligand on the structure and properties of cobalamins are re-examined in light of the present results. Particular emphasis is placed on the axial fragment. This analysis substantially confirms and, with the new data reported here, adjusts and expands the data set for correlations between trans and cis influences of the β-ligand of cobalamins and their structure (Co-X and Co-NB3 distances and corrin fold angle) and properties (UV-vis spectra, NMR spectra, and pK(base-off)).

  5. 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.

  6. The mitochondrial toxicity of cysteine-S-conjugates: Studies with pentachlorobutadienyl-L-cysteine

    International Nuclear Information System (INIS)

    Wallin, A.

    1990-01-01

    Nephrotoxic cysteine conjugates, arising from mercapturate biosynthesis, can perturb the mitochondrial membrane potential and calcium homeostasis in renal epithelial cells. Activation of these cysteine conjugates to reactive species by mitochondrial β-lyases results in covalent binding and mitochondrial damage. PCBC and related cysteine conjugates inhibit ADP-stimulated respiration in mitochondria respiring on alpha-ketoglutrate/malate and succinate indicating that both dehydrogenases may be targets. The respiratory inhibition is blocked by aminooxyacetic acid, an inhibitor of the β-lyase. Hence, metabolic activation is required implying that covalent binding of reactive intermediates may be important to the mitochondrial injury. Binding of 35 S-fragments has been found for 5 conjugates with varying degrees of mitochondrial toxicity. PCBC is more lipophilic and has a higher affinity for cellular membranes than other cysteine conjugates. PCBC rapidly depolarizes the inner membrane potential resulting in an inhibition of mitochondrial oxidative phosphorylation and calcium upon sequestration. Consequently, mitochondria and renal epithelial cells exposed to PCBC show a sudden release of calcium upon exposure to PCBC which is followed by a later increase in state 4 respiration leading to an inhibition of oxidative phosphorylation. The primary effect of other cysteine conjugates is an inhibition of the dehydrogenases, thus inhibiting state 3 respiration

  7. Preclinical evaluation of isostructural Tc-99m- and Re-188-folate-Gly-Gly-Cys-Glu for folate receptor-positive tumor targeting.

    Science.gov (United States)

    Kim, Woo Hyoung; Kim, Chang Guhn; Kim, Myoung Hyoun; Kim, Dae-Weung; Park, Cho Rong; Park, Ji Yong; Lee, Yun-Sang; Youn, Hyewon; Kang, Keon Wook; Jeong, Jae Min; Chung, June-Key

    2016-06-01

    The purpose of the present study was to prepare isostructural Tc-99m- and Re-188-folate-Gly-Gly-Cys-Glu (folate-GGCE), and to evaluate the feasibility of their use for folate receptor (FR)-targeted molecular imaging and as theranostic agents in a mouse tumor model. Folate-GGCE was synthesized using solid-phase peptide synthesis and radiolabeled with Tc-99m or Re-188. Radiochemical characterization was performed by radio-high-performance liquid chromatography. The biodistribution of Tc-99m-folate-GGCE was studied, with or without co-injection of excess free folate, in mice bearing both FR-positive (KB cell) and FR-negative (HT1080 cell) tumors. Biodistribution of Re-188-folate-GGCE was studied in mice bearing KB tumors. Serial planar scintigraphy was performed in the dual tumor mouse model after intravenous injection of Tc-99m-folate-GGCE. Serial micro-single photon emission computed tomography/computed tomography (SPECT/CT) studies were performed, with or without co-injection of excess free folate, in the mouse tumor model after injection of Tc-99m-folate-GGCE or Re-188-folate-GGCE. The radiolabeling efficiency and radiochemical stability of Tc-99m- and Re-188-folate-GGCE were more than 95 % for up to 4 h after radiolabeling. Uptake of Tc-99m-folate-GGCE at 1, 2, and 4 h after injection in KB tumor was 16.4, 23.2, and 17.6 % injected dose per gram (%ID/g), respectively. This uptake was suppressed by 97.4 % when excess free folate was co-administered. Tumor:normal organ ratios at 4 h for blood, liver, lung, muscle, and kidney were 54.3, 25.2, 38.3, 97.8, and 0.3, respectively. Tumor uptake of Re-188-folate-GGCE at 2, 4, 8, and 16 h after injection was 17.4, 21.7, 24.1, and 15.6 %ID/g, respectively. Tumor:normal organ ratios at 8 h for blood, liver, lung, muscle, and kidney were 126.8, 21.9, 54.8, 80.3, and 0.4, respectively. KB tumors were clearly visualized at a high intensity using serial scintigraphy and micro-SPECT/CT in mice injected with Tc-99m- or Re

  8. Synthesis and evaluation of boronated folates for BNCT

    International Nuclear Information System (INIS)

    Shukla, S.; Sekido, M.; Guo, W.; Mueller, R.; Sudimack, J.; Lee, R.J.; Tjarks, W.; Adams, D.M.; Barth, R.F.

    2000-01-01

    To study the possible utilization of folic acid as the 10 B carrier for BNCT, folic acid conjugated boron containing liposomes and starburst dendrimers were prepared. In both systems folic acid was used as the recognition part and polyethylene glycol (PEG) as the spacer. In vitro studies were carried out using folate receptor overexpressing 24JK-FBP and KB cells. The results indicated that these boronated folic acid conjugates were incorporated into the tumor cells via receptor-mediated endocytosis. (author)

  9. Effects of yeasts and bacteria on the levels of folates in rye sourdoughs.

    Science.gov (United States)

    Kariluoto, Susanna; Aittamaa, Marja; Korhola, Matti; Salovaara, Hannu; Vahteristo, Liisa; Piironen, Vieno

    2006-02-01

    Fermentation of rye dough is often accompanied with an increase in folate content. In this study, three sourdough yeasts, Candida milleri CBS 8195, Saccharomyces cerevisiae TS 146, and Torulaspora delbrueckii TS 207; a control, baker's yeast S. cerevisiae ALKO 743; and four Lactobacillus spp., L. acidophilus TSB 262, L. brevis TSB 307, L. plantarum TSB 304, and L. sanfranciscensis TSB 299 originally isolated from rye sourdough were examined for their abilities to produce or consume folates. The microorganisms were grown in yeast extract-peptone-d-glucose medium as well as in small-scale fermentations that modelled the sourdough fermentation step used in rye baking. Total folate contents were determined using Lactobacillus rhamnosus (ATCC 7469) as the growth indicator organism. The microorganisms studied did not excrete folates into the media in significant amounts. Yeasts increased the folate contents of sterilised rye flour-water mixtures from 6.5 microg/100 g to between 15 and 23 microg/100 g after 19-h fermentation, whereas lactic acid bacteria decreased it to between 2.9 and 4.2 microg/100 g. Strains of Lactobacillus bulgaricus, L. casei, L. curvatus, L. fermentum, L. helveticus, Pediococcus spp., and Streptococcus thermophilus that were also tested gave folate contents after fermentation that varied between 2 and 10.4 microg/100 g. Although the four Lactobacillus spp. from sourdough consumed folates their effect on folate contents in co-cultivations was minimal. It was concluded that the increase of folate content during fermentation was mainly due to folate synthesis by yeasts. Fermentation of non-sterilised flour-water mixtures as such resulted in three-fold increases in the folate contents. Two folate producing bacteria were isolated from the non-sterilised flour and identified as Enterobacter cowanii and Pantoea agglomerans.

  10. Genetic Variation Throughout the Folate Metabolic Pathway Influences Negative Symptom Severity in Schizophrenia

    OpenAIRE

    Roffman, Joshua L.; Brohawn, David G.; Nitenson, Adam Z.; Macklin, Eric A.; Smoller, Jordan W.; Goff, Donald C.

    2011-01-01

    Low serum folate levels previously have been associated with negative symptom risk in schizophrenia, as has the hypofunctional 677C>T variant of the MTHFR gene. This study examined whether other missense polymorphisms in folate-regulating enzymes, in concert with MTHFR, influence negative symptoms in schizophrenia, and whether total risk allele load interacts with serum folate status to further stratify negative symptom risk. Medicated outpatients with schizophrenia (n = 219), all of European...

  11. Professor John Scott, folate and neural tube defects.

    Science.gov (United States)

    Hoffbrand, A Victor

    2014-02-01

    John Scott (1940-2013) was born in Dublin where he was to spend the rest of his career, both as an undergraduate and subsequently Professor of Biochemistry and Nutrition at Trinity College. His research with the talented group of scientists and clinicians that he led has had a substantial impact on our understanding of folate metabolism, mechanisms of its catabolism and deficiency. His research established the leading theory of folate involvement with vitamin B12 in the pathogenesis of vitamin B12 neuropathy. He helped to establish the normal daily intake of folate and the increased requirements needed either in food or as a supplement before and during pregnancy to prevent neural tube defects. He also suggested a dietary supplement of vitamin B12 before and during pregnancy to reduce the risk of neural tube defects. It would be an appropriate epitaph if fortification of food with folic acid became mandatory in the UK and Ireland, as it is in over 70 other countries. © 2013 John Wiley & Sons Ltd.

  12. Periconceptional Folate Deficiency and Implications in Neural Tube Defects

    Directory of Open Access Journals (Sweden)

    J. Safi

    2012-01-01

    Full Text Available Nutritional deficiencies are preventable etiological and epigenetic factors causing congenital abnormalities, first cause of infant mortality. Folate deficiency has a well-established teratogenic effect, leading to an increasing risk of neural tube defects. This paper highlights the most recent medical literature about folate deficiency, be it maternal or paternal. It then focuses on associated deficiencies as nutritional deficiencies are multiple and interrelated. Observational and interventional studies have all been consistent with a 50–70% protective effect of adequate women consumption of folates on neural tube defects. Since strategies to modify women’s dietary habits and vitamin use have achieved little progress, scientific as well as political effort is mandatory in order to implement global preventive public health strategies aimed at improving the alimentation of women in reproductive age, especially folic acid supplementation. Even with the recent breakthrough of fetal surgery for myelomeningocele, the emphasis should still be on prevention as the best practice rather than treatment of neural tube defects.

  13. Nutriepigenetic regulation by folate-homocysteine-methionine axis: a review.

    Science.gov (United States)

    Bhargava, Seema; Tyagi, S C

    2014-02-01

    Although normally folic acid is given during pregnancy, presumably to prevent neural tube defects, the mechanisms of this protection are unknown. More importantly it is unclear whether folic acid has other function during development. It is known that folic acid re-methylates homocysteine (Hcy) to methionine by methylene tetrahydrofolate reductase-dependent pathways. Folic acid also generates high-energy phosphates, behaves as an antioxidant and improves nitric oxide (NO) production by endothelial NO synthase. Interestingly, during epigenetic modification, methylation of DNA/RNA generate homocysteine unequivocally. The enhanced overexpression of methyl transferase lead to increased yield of Hcy. The accumulation of Hcy causes vascular dysfunction, reduces perfusion in the muscles thereby causing musculopathy. Another interesting fact is that children with severe hyperhomocysteinaemia (HHcy) have skeletal deformities, and do not live past teenage. HHcy is also associated with the progeria syndrome. Epilepsy is primarily caused by inhibition of gamma-amino-butyric-acid (GABA) receptor, an inhibitory neurotransmitter in the neuronal synapse. Folate deficiency leads to HHcy which then competes with GABA for binding on the GABA receptors. With so many genetic and clinical manifestations associated with folate deficiency, we propose that folate deficiency induces epigenetic alterations in the genes and thereby results in disease.

  14. Rethinking Cysteine Protective Groups: S-Alkylsulfonyl-l-Cysteines for Chemoselective Disulfide Formation.

    Science.gov (United States)

    Schäfer, Olga; Huesmann, David; Muhl, Christian; Barz, Matthias

    2016-12-12

    The ability to reversibly cross-link proteins and peptides grants the amino acid cysteine its unique role in nature as well as in peptide chemistry. We report a novel class of S-alkylsulfonyl-l-cysteines and N-carboxy anhydrides (NCA) thereof for peptide synthesis. The S-alkylsulfonyl group is stable against amines and thus enables its use under Fmoc chemistry conditions and the controlled polymerization of the corresponding NCAs yielding well-defined homo- as well as block co-polymers. Yet, thiols react immediately with the S-alkylsulfonyl group forming asymmetric disulfides. Therefore, we introduce the first reactive cysteine derivative for efficient and chemoselective disulfide formation in synthetic polypeptides, thus bypassing additional protective group cleavage steps. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Folate and Colorectal Cancer in Rodents: A Model of DNA Repair Deficiency

    Directory of Open Access Journals (Sweden)

    Rita Rosati

    2012-01-01

    Full Text Available Fortification of grains has resulted in a positive public health outcome vis-a-vis reduced incidence of neural tube defects. Whether folate has a correspondingly beneficial effect on other disease outcomes is less clear. A role for dietary folate in the prevention of colorectal cancer has been established through epidemiological data. Experimental data aiming to further elucidate this relationship has been somewhat equivocal. Studies report that folate depletion increases DNA damage, mutagenesis, and chromosomal instability, all suggesting inhibited DNA repair. While these data connecting folate depletion and inhibition of DNA repair are convincing, we also present data demonstrating that genetic inhibition of DNA repair is protective in the development of preneoplastic colon lesions, both when folate is depleted and when it is not. The purpose of this paper is to (1 give an overview of the data demonstrating a DNA repair defect in response to folate depletion, and (2 critically compare and contrast the experimental designs utilized in folate/colorectal cancer research and the corresponding impact on tissue folate status and critical colorectal cancer endpoints. Our analysis suggests that there is still an important need for a comprehensive evaluation of the impact of differential dietary prescriptions on blood and tissue folate status.

  16. Mechanistic Target of Rapamycin Is a Novel Molecular Mechanism Linking Folate Availability and Cell Function.

    Science.gov (United States)

    Silva, Elena; Rosario, Fredrick J; Powell, Theresa L; Jansson, Thomas

    2017-07-01

    Folate deficiency has been linked to a wide range of disorders, including cancer, neural tube defects, and fetal growth restriction. Folate regulates cellular function mediated by its involvement in the synthesis of nucleotides, which are needed for DNA synthesis, and its function as a methyl donor, which is critical for DNA methylation. Here we review current data showing that folate sensing by mechanistic target of rapamycin (mTOR) constitutes a novel and distinct pathway by which folate modulates cell functions such as nutrient transport, protein synthesis, and mitochondrial respiration. The mTOR signaling pathway responds to growth factors and changes in nutrient availability to control cell growth, proliferation, and metabolism. mTOR exists in 2 complexes, mTOR complex (mTORC) 1 and mTORC2, which have distinct upstream regulators and downstream targets. Folate deficiency in pregnant mice caused a marked inhibition of mTORC1 and mTORC2 signaling in multiple maternal and fetal tissues, downregulation of placental amino acid transporters, and fetal growth restriction. In addition, folate deficiency in primary human trophoblast (PHT) cells resulted in inhibition of mTORC1 and mTORC2 signaling and decreased the activity of key amino acid transporters. Folate sensing by mTOR in PHT cells is independent of the accumulation of homocysteine and requires the proton-coupled folate transporter (PCFT; solute carrier 46A1). Furthermore, mTORC1 and mTORC2 regulate trophoblast folate uptake by modulating the cell surface expression of folate receptor α and the reduced folate carrier. These findings, which provide a novel link between folate availability and cell function, growth, and proliferation, may have broad biological significance given the critical role of folate in normal cell function and the multiple diseases that have been associated with decreased or excessive folate availability. Low maternal folate concentrations are linked to restricted fetal growth, and we

  17. Plasma homocyst(e)ine concentrations in pregnant and nonpregnant women with controlled folate intake.

    Science.gov (United States)

    Bonnette, R E; Caudill, M A; Boddie, A M; Hutson, A D; Kauwell, G P; Bailey, L B

    1998-08-01

    To assess the effects of folate intake and pregnancy on plasma total homocyst(e)ine concentrations in women during the second trimester of pregnancy compared with young, healthy nonpregnant women. The diet provided either 450 or 850 microg of folate per day. These levels are approximately the current (400 microg/day) and previous (800 microg/day) Recommended Dietary Allowances for folate in pregnant women. Folate was provided as both food folate (120 microg/day) and supplemental folic acid (either 330 or 730 microg/day) for a period of 12 weeks. Plasma homocyst(e)ine (sum of free and protein-bound homocysteine), serum folate, and erythrocyte folate concentrations were determined weekly. Homocyst(e)ine concentrations were lower in pregnant women during the second trimester of normal pregnancy than in nonpregnant controls, independent of dietary folate intake. The overall mean (+/- standard deviation) homocyst(e)ine concentration of the pregnant subjects (5.4 +/- 1.4 micromol/L) was significantly lower than that observed in the nonpregnant control group (8.7 +/- 1.7 micromol/L) (P ine concentrations remained constant throughout the 12 weeks of the investigation. The folate intakes in this investigation were adequate to maintain constant homocyst(e)ine concentrations in pregnant and nonpregnant women. The lower homocyst(e)ine concentrations observed in pregnant subjects compared with nonpregnant controls may be a physiologic response to pregnancy.

  18. Chemical synthesis of deuterated folate monoglutamate and in vivo assessment of urinary excretion of deuterated folates in man

    International Nuclear Information System (INIS)

    Gregory, J.F. III; Toth, J.P.

    1988-01-01

    The synthesis and in vivo application of stable-isotopically labeled folic acid was investigated to devise methods suitable for studies of folate metabolism in human subjects. Glutamate-labeled tetradeutero-pteroylglutamic acid (d4-folic acid) was prepared by mixed anhydride coupling of N10-trifluoroacetylpteroic acid and dimethyl L-[3,3,4,4-2H4]glutamic acid, saponification in sodium deuteroxide, and chromatographic purification. Retention of the isotopic label was verified by proton NMR and mass spectrometry of the para-aminobenzoylglutamic acid product of C9-N10 bond cleavage. A method was devised for determination of of isotopic enrichment of urinary d4-folates derived from orally administered d4-folic acid using affinity chromatographic purification, chemical cleavage of the C9-N10 bond, HPLC isolation of the p-[2H4]aminobenzoylglutamate product, followed by negative-ion chemical-ionization gas chromatography/mass spectrometry. Data concerning the urinary excretion of d4-folates derived from an oral dose of d4-folic acid in an adult human are presented

  19. Pulse photolysis of NADH in the presence of cysteine

    International Nuclear Information System (INIS)

    Scheel, H.E.

    1976-01-01

    In the UV irradiation of NADH under anaerobic conditions, cysteine, which often acts as a radioprotective substance, has a sensitizing effect. With the aid of pulse photolysis, it was studied which reaction mechanisms in the presence or absence of cysteine are responsible for the damage to NADH in aqueous solution. In the absence of cysteine, the characteristic NADH absorption at 340 nm is reduced immediately after UV quanta have been absorbed by the adenine fraction of the molecules; in the presence of cysteine, a secondary reaction causes additional damage. The spectra of the intermediate products of NADH and cysteine have been recorded for different cysteine concentrations, and the reaction constants have been determined. These values suggest that the sensitizing effect is due to a reaction of NADH with radical anions produced by photolysis. (orig.) [de

  20. Modulation of ion transport across rat distal colon by cysteine

    Directory of Open Access Journals (Sweden)

    Martin eDiener

    2012-03-01

    Full Text Available The aim of this study was to identify the actions of stimulation of endogenous production of H2S by cysteine, the substrate for the two H2S-producing enzymes, cystathionin-beta-synthase and cystathionin-gamma-lyase, on ion transport across rat distal colon. Changes in short-circuit current (Isc induced by cysteine were measured in Ussing chambers. Free cysteine caused a concentration-dependent, transient fall in Isc, which was sensitive to amino-oxyacetate and beta-cyano-L-alanine, i.e. inhibitors of H2S-producing enzymes. In contrast, Na cysteinate evoked a biphasic change in Isc, i.e. an initial fall followed by a secondary increase, which was also reduced by these enzyme inhibitors. All responses were dependent on the presence of Cl- and inhibited by bumetanide, suggesting that free cysteine induces an inhibition of transcellular Cl- secretion, whereas Na cysteinate – after a transient inhibitory phase – activates anion secretion. The assumed reason for this discrepancy is a fall in the cytosolic pH induced by free cysteine, but not by Na cysteinate, as observed in isolated colonic crypts loaded with the pH-sensitive dye, BCECF. Intracellular acidification is known to inhibit epithelial K+ channels. Indeed, after preinhibition of basolateral K+ channels with tetrapentylammonium or Ba2+, the negative Isc induced by free cysteine was reduced significantly. In consequence, stimulation of endogenous H2S production by Na cysteinate causes, after a short inhibitory response, a delayed activation of anion secretion, which is missing in the case of free cysteine, probably due to the cytosolic acidification. In contrast, diallyl trisulfide, which is intracellularly converted to H2S, only evoked a monophasic increase in Isc without the initial fall observed with Na cysteinate. Consequently, time course and amount of produced H2S seem to strongly influence the functional response of the colonic epithelium evoked by this gasotransmitter.

  1. Protein modification by acrolein: Formation and stability of cysteine adducts

    OpenAIRE

    Cai, Jian; Bhatnagar, Aruni; Pierce, William M.

    2009-01-01

    The toxicity of the ubiquitous pollutant and endogenous metabolite, acrolein, is due in part to covalent protein modifications. Acrolein reacts readily with protein nucleophiles via Michael addition and Schiff base formation. Potential acrolein targets in protein include the nucleophilic side chains of cysteine, histidine, and lysine residues as well as the free amino terminus of proteins. Although cysteine is the most acrolein-reactive residue, cysteine-acrolein adducts are difficult to iden...

  2. [Determination of folate content in ready-to-eat food products].

    Science.gov (United States)

    Fajardo Martín, Violeta; Alonso-Aperte, Elena; Varela-Moreiras, Gregorio

    2013-01-01

    In the last years, the consumption of ready-to-eat foods has become an increasing part of the current Spanish diet. Accordingly, the nutritional composition of these food categories should be investigated in order to estimate its contribution to vitamin and nutrient intakes, in particular its folate content. The broad lack of folate data in food composition tables and databases justifies this approach. The aim of this work was to screen the current availability and to supply new folate data in ready-to-eat commercial products in the Spanish market. Seventeen ready-to-eat foods, including mainly vegetable ingredients, were analysed for total folate content using a validated method that relies on Lactobacillus casei ssp. rhamnosus chloramphenicol-resistant folate dependent growth. The accuracy of the analytical procedure was checked using a certified reference material and by a recovery test. Mean TF content ranged from 13.6 to 103.8 μg/100 g in different food matrices on a fresh weight basis. Higher TF quantity was found for vegetable hamburguers, recipes including chickpeas, peas or artichockes. Selected precooked products were also analysed after a soft heat treatment as recommended by the manufacter before its consumption. No significant differences were found in the folate content after processing. The coefficient of variation for the duplicates of the same product was less than 15%. Folate content in ready-to-eat products indicates the potential to considerably increase folate intake by choosing folate-rich foods. There have been no previous reports on folate data in chilled ready-to-eat meals. The present data will assist dietary studies to estimate and evaluate the adequacy of population folate intakes. Copyright © AULA MEDICA EDICIONES 2013. Published by AULA MEDICA. All rights reserved.

  3. Effects of betaine supplementation and choline deficiency on folate deficiency-induced hyperhomocysteinemia in rats.

    Science.gov (United States)

    Liu, Ying; Liu, Yi-qun; Morita, Tatsuya; Sugiyama, Kimio

    2012-01-01

    The effect of betaine status on folate deficiency-induced hyperhomocysteinemia was investigated to determine whether folate deficiency impairs homocysteine removal not only by the methionine synthase (MS) pathway but also by the betaine-homocysteine S-methyltransferase (BHMT) pathway. For this purpose, we investigated the effect of dietary supplementation with betaine at a high level (1%) in rats fed a folate-deprived 10% casein diet (10C) and 20% casein diet (20C). We also investigated the effect of choline deprivation on folate deficiency-induced hyperhomocysteinemia in rats fed 20C. Supplementation of folate-deprived 10C and 20C with 1% betaine significantly suppressed folate deprivation-induced hyperhomocysteinemia, but the extent of suppression was partial or limited, especially in rats fed 10C, the suppression of plasma homocysteine increment being 48.5% in rats fed 10C and 69.7% in rats fed 20C. Although betaine supplementation greatly increased hepatic betaine concentration and BHMT activity, these increases did not fully explain why the effect of betaine supplementation was partial or limited. Folate deprivation markedly increased the hepatic concentration of N,N-dimethylglycine (DMG), a known inhibitor of BHMT, and there was a significant positive correlation between hepatic DMG concentration and plasma homocysteine concentration, suggesting that folate deficiency increases hepatic DMG concentration and thereby depresses BHMT reaction, leading to interference with the effect of betaine supplementation. Choline deprivation did not increase plasma homocysteine concentration in rats fed 20C, but it markedly enhanced plasma homocysteine concentration when rats were fed folate-deprived 20C. This indicates that choline deprivation reinforced folate deprivation-induced hyperhomocysteinemia. Increased hepatic DMG concentration was also associated with such an effect. These results support the concept that folate deficiency impairs homocysteine metabolism not only

  4. Cysteine-containing peptides having antioxidant properties

    Science.gov (United States)

    Bielicki, John K [Castro Valley, CA

    2008-10-21

    Cysteine containing amphipathic alpha helices of the exchangeable apolipoproteins, as exemplified by apolipoprotein (apo) A-I.sub.Milano (R173C) and apoA-I.sub.Paris, (R151C) were found to exhibit potent antioxidant activity on phospholipid surfaces. The addition of a free thiol, at the hydrophobic/hydrophilic interface of an amphipathic alpha helix of synthetic peptides that mimic HDL-related proteins, imparts a unique antioxidant activity to these peptides which inhibits lipid peroxidation and protects phospholipids from water-soluble free radical initiators. These peptides can be used as therapeutic agents to combat cardiovascular disease, ischemia, bone disease and other inflammatory related diseases.

  5. How is the process of setting micronutrients recommendations reflected in nutrition policies in Poland? The case study of folate

    Directory of Open Access Journals (Sweden)

    Ewa Sicińska

    2018-03-01

    The current Polish nutrition recommendations for folate are consistent with the levels set by most other countries. The constant improvement of nutritional knowledge on folate among consumers, especially young women, is necessary.

  6. Heterologous expression of Hordeum vulgare cysteine protease in yeast

    DEFF Research Database (Denmark)

    Rosenkilde, Anne Lind; Dionisio, Giuseppe; Holm, Preben B

    Cysteine Proteases accounts for more than 90 % of the total proteolytic activity in the degradation of barley seed storage proteins during germination. Several Cysteine proteases have been identified in barley. One of the key enzymes, Hordeum vulgare endoprotease B2 (HvEPB2) was cloned with and w......Cysteine Proteases accounts for more than 90 % of the total proteolytic activity in the degradation of barley seed storage proteins during germination. Several Cysteine proteases have been identified in barley. One of the key enzymes, Hordeum vulgare endoprotease B2 (HvEPB2) was cloned...

  7. Clinical utility of serum folate measurement in tertiary care patients: Argument for revising reference range for serum folate from 3.0 ng/mL to 13.0 ng/mL

    Directory of Open Access Journals (Sweden)

    Gurmukh Singh

    2015-04-01

    Full Text Available Objective: Assess the need for folate testing, frequency of corrective action, and determine reference level for serum folate. Methods: Serum folate levels in 5313 samples from 4448 patients, and clinical data were reviewed for patient characteristics and for (a evidence of corrective action in patients with serum folate values 25.7 ng/mL. Results: The prevalence of serum folate levels, in patients, 25.7 ng/mL the sample was collected after supplementation with folic acid. Of the 128 patients with serum folate 60% of the patients. Since serum folate levels ≥13.0 ng/mL are needed for optimal prevention of neural tube defects in the embryo/fetus, we propose that normal serum folate level should be designated to be ≥13.0 ng/mL. Keywords: Serum folate, Prevalence of folate deficiency, Neural tube defects, Optimum serum folate level, Utility of folate testing

  8. Soft Cysteine Signaling Network: The Functional Significance of Cysteine in Protein Function and the Soft Acids/Bases Thiol Chemistry That Facilitates Cysteine Modification.

    Science.gov (United States)

    Wible, Ryan S; Sutter, Thomas R

    2017-03-20

    The unique biophysical and electronic properties of cysteine make this molecule one of the most biologically critical amino acids in the proteome. The defining sulfur atom in cysteine is much larger than the oxygen and nitrogen atoms more commonly found in the other amino acids. As a result of its size, the valence electrons of sulfur are highly polarizable. Unique protein microenvironments favor the polarization of sulfur, thus increasing the overt reactivity of cysteine. Here, we provide a brief overview of the endogenous generation of reactive oxygen and electrophilic species and specific examples of enzymes and transcription factors in which the oxidation or covalent modification of cysteine in those proteins modulates their function. The perspective concludes with a discussion of cysteine chemistry and biophysics, the hard and soft acids and bases model, and the proposal of the Soft Cysteine Signaling Network: a hypothesis proposing the existence of a complex signaling network governed by layered chemical reactivity and cross-talk in which the chemical modification of reactive cysteine in biological networks triggers the reorganization of intracellular biochemistry to mitigate spikes in endogenous or exogenous oxidative or electrophilic stress.

  9. Folate Biofortification in Hydroponically Cultivated Spinach by the Addition of Phenylalanine.

    Science.gov (United States)

    Watanabe, Sho; Ohtani, Yuta; Tatsukami, Yohei; Aoki, Wataru; Amemiya, Takashi; Sukekiyo, Yasunori; Kubokawa, Seiichi; Ueda, Mitsuyoshi

    2017-06-14

    Folate is an important vitamin mainly ingested from vegetables, and folate deficiency causes various health problems. Recently, several studies demonstrated folate biofortification in plants or food crops by metabolic engineering through genetic modifications. However, the production and sales of genetically modified foods are under strict regulation. Here, we developed a new approach to achieve folate biofortification in spinach (Spinacia oleracea) without genetic modification. We hydroponically cultivated spinach with the addition of three candidate compounds expected to fortify folate. As a result of liquid chromatography tandem mass spectrometry analysis, we found that the addition of phenylalanine increased the folate content up to 2.0-fold (306 μg in 100 g of fresh spinach), representing 76.5% of the recommended daily allowance for adults. By measuring the intermediates of folate biosynthesis, we revealed that phenylalanine activated folate biosynthesis in spinach by increasing the levels of pteridine and p-aminobenzoic acid. Our approach is a promising and practical approach to cultivate nutrient-enriched vegetables.

  10. Folates in Asian noodles: II. A comparison of commercial samples and the impact of cooking.

    Science.gov (United States)

    Bui, Lan T T; Small, Darryl M

    2007-06-01

    The folate contents of 26 commercial noodle samples were investigated. The impact of ingredients, pH, and cooking on folate content was studied for the 3 predominant styles of noodles: white salted, yellow alkaline, and instant. Some variability was found in the proportion of folate present in the free form and the noodles generally had low total folate contents. The pH values of the samples covered a wide range, varying from 3.7 to 10.3; however, the results did not provide strong evidence for a relationship between pH and folate content for any of the noodle styles studied. Higher folate levels were typically found in yellow alkaline samples compared to white salted and instant noodles. The storage of noodles in dry or moist forms did not appear to influence total folate contents, and subsequent losses during cooking depended upon the time of exposure to elevated temperatures. The enzymatic treatment of samples was particularly important for cooked noodles, indicating that folates were bound or entrapped during this process.

  11. Folate intake, lifestyle factors, and homocysteine concentrations in younger and older women

    DEFF Research Database (Denmark)

    Rasmussen, Lone Banke; Ovesen, L.; Bulow, I.

    2000-01-01

    Background: An elevated total homocysteine (tHcy) concentration is considered to be an independent risk factor for cardiovascular diseases and has also been associated with an increased risk of neural tube defects. Objective: The objective of this study was to investigate folate intake, folate st...

  12. Concentration of folate in colorectal tissue biopsies predicts prevalence of adenomatous polyps

    Science.gov (United States)

    Background and aims: Folate has been implicated as a potential aetiological factor for colorectal cancer. Previous research has not adequately exploited concentrations of folate in normal colonic mucosal biopsies to examine the issue. Methods: Logistic regression models were used to estimate ORs ...

  13. Methionine synthase A2756G and reduced folate carrier1 A80G ...

    African Journals Online (AJOL)

    Maha Moustafa

    2015-10-09

    Oct 9, 2015 ... folate carrier (RFC1) A80G gene polymorphisms on the maternal risk for DS. Patients: This ... Peer review under responsibility of Ain Shams University. ... Folate is the general term for a water-soluble B vitamin (vita- min B9) ...

  14. Folate mediated self-assembled phytosterol-alginate nanoparticles for targeted intracellular anticancer drug delivery.

    Science.gov (United States)

    Wang, Jianting; Wang, Ming; Zheng, Mingming; Guo, Qiong; Wang, Yafan; Wang, Heqing; Xie, Xiangrong; Huang, Fenghong; Gong, Renmin

    2015-05-01

    Self-assembled core/shell nanoparticles (NPs) were synthesized from water-soluble alginate substituted by hydrophobic phytosterols. Folate, a cancer-cell-specific ligand, was conjugated to the phytosterol-alginate (PA) NPs for targeting folate-receptor-overexpressing cancer cells. The physicochemical properties of folate-phytosterol-alginate (FPA) NPs were characterized by nuclear magnetic resonance, transmission electron microscopy, dynamic light scattering, electrophoretic light scattering, and fluorescence spectroscopy. Doxorubicin (DOX), an anticancer drug, was entrapped inside prepared NPs by dialysis method. The identification of prepared FPA NPs to folate-receptor-overexpressing cancer cells (KB cells) was confirmed by cytotoxicity and folate competition assays. Compared to the pure DOX and DOX/PA NPs, the DOX/FPA NPs had lower IC50 value to KB cells because of folate-receptor-mediated endocytosis process and the cytotoxicity of DOX/FPA NPs to KB cells could be competitively inhibited by free folate. The cellular uptake and internalization of pure DOX and DOX/FPA NPs was confirmed by confocal laser scanning microscopy image and the higher intracellular uptake of drug for DOX/FPA NPs over pure DOX was observed. The FPA NPs had the potential as a promising carrier to target drugs to cancer cells overexpressing folate receptors and avoid cytotoxicity to normal tissues. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Identification of Genes Encoding the Folate- and Thiamine-Binding Membrane Proteins in Firmicutes

    NARCIS (Netherlands)

    Eudes, Aymerick; Erkens, Guus B.; Slotboom, Dirk J.; Rodionov, Dmitry A.; Naponelli, Valeria; Hanson, Andrew D.

    Genes encoding high-affinity folate- and thiamine-binding proteins (FolT, ThiT) were identified in the Lactobacillus casei genome, expressed in Lactococcus lactis, and functionally characterized. Similar genes occur in many Firmicutes, sometimes next to folate or thiamine salvage genes. Most thiT

  16. Excessive folate synthesis limits lifespan in the C. elegans: E. coli aging model

    Directory of Open Access Journals (Sweden)

    Virk Bhupinder

    2012-07-01

    Full Text Available Abstract Background Gut microbes influence animal health and thus, are potential targets for interventions that slow aging. Live E. coli provides the nematode worm Caenorhabditis elegans with vital micronutrients, such as folates that cannot be synthesized by animals. However, the microbe also limits C. elegans lifespan. Understanding these interactions may shed light on how intestinal microbes influence mammalian aging. Results Serendipitously, we isolated an E. coli mutant that slows C. elegans aging. We identified the disrupted gene to be aroD, which is required to synthesize aromatic compounds in the microbe. Adding back aromatic compounds to the media revealed that the increased C. elegans lifespan was caused by decreased availability of para-aminobenzoic acid, a precursor to folate. Consistent with this result, inhibition of folate synthesis by sulfamethoxazole, a sulfonamide, led to a dose-dependent increase in C. elegans lifespan. As expected, these treatments caused a decrease in bacterial and worm folate levels, as measured by mass spectrometry of intact folates. The folate cycle is essential for cellular biosynthesis. However, bacterial proliferation and C. elegans growth and reproduction were unaffected under the conditions that increased lifespan. Conclusions In this animal:microbe system, folates are in excess of that required for biosynthesis. This study suggests that microbial folate synthesis is a pharmacologically accessible target to slow animal aging without detrimental effects.

  17. Dietary folate deficiency blocks prostate cancer progression in the TRAMP model.

    Science.gov (United States)

    Bistulfi, Gaia; Foster, Barbara A; Karasik, Ellen; Gillard, Bryan; Miecznikowski, Jeff; Dhiman, Vineet K; Smiraglia, Dominic J

    2011-11-01

    Dietary folate is essential in all tissues to maintain several metabolite pools and cellular proliferation. Prostate cells, due to specific metabolic characteristics, have increased folate demand to support proliferation and prevent genetic and epigenetic damage. Although several studies have found that dietary folate interventions can affect colon cancer biology in rodent models, its impact on prostate is unknown. The purpose of this study was to determine whether dietary folate manipulation, possibly being of primary importance for prostate epithelial cell metabolism, could significantly affect prostate cancer progression. Strikingly, mild dietary folate depletion arrested prostate cancer progression in 25 of 26 transgenic adenoma of the mouse prostate (TRAMP) mice, in which tumorigenesis is prostate-specific and characteristically aggressive. The significant effect on prostate cancer growth was characterized by size, grade, proliferation, and apoptosis analyses. Folate supplementation had a mild, nonsignificant, beneficial effect on grade. In addition, characterization of folate pools (correlated with serum), metabolite pools (polyamines and nucleotides), genetic and epigenetic damage, and expression of key biosynthetic enzymes in prostate tissue revealed interesting correlations with tumor progression. These findings indicate that prostate cancer is highly sensitive to folate manipulation and suggest that antifolates, paired with current therapeutic strategies, might significantly improve treatment of prostate cancer, the most commonly diagnosed cancer in American men.

  18. Folate content and retention in commonly consumed vegetables in the South Pacific.

    Science.gov (United States)

    Maharaj, Prayna P P; Prasad, Surendra; Devi, Riteshma; Gopalan, Romila

    2015-09-01

    This paper reports the effect of boiling and frying on the retention of folate in commonly consumed Fijian vegetables (drumstick leaves, taro leaves, bele leaves, amaranth leaves, fern/ota, okra and French bean). The folate content was determined by microbiological assay (Lactobacillus casei rhamnosus) and tri-enzyme (protease, α-amylase and chicken pancreas conjugase) extraction treatment. The folate loss varied among the vegetables from 10-64% on boiling while 1-36% on frying. The higher folate loss was observed during boiling. The folate content in the water derived after boiling different vegetables ranged from 11.9 ± 0.5 to 61.6 ± 2.5 μg/100mL. The folate loss on boiling was accounted for in the cooking water. The predominant way of folate loss on boiling was leaching rather than thermal degradation which makes boiling the better choice of cooking the studied vegetables for folate intake, provided the cooking water is consumed together with the vegetables. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Framework for laboratory harmonization of folate measurements in low- and middle-income countries and regions.

    Science.gov (United States)

    Pfeiffer, Christine M; Zhang, Mindy; Jabbar, Shameem

    2018-02-01

    The measurement of serum and red blood cell folate, two commonly used biomarkers of folate status in populations, is complicated by analytical and data interpretation challenges. Folate results show poor comparability across laboratories, even using the same analytical technique. The folate microbiologic assay produces accurate results and requires simple instrumentation. Thus, it could be set up and maintained in low- and middle-income country laboratories. However, the assay has to be harmonized through the use of common critical reagents (e.g., microorganism and folate calibrator) in order to produce comparable results across laboratories and over time, so that the same cutoff values can be applied across surveys. There is a limited need for blood folate measurements in a country owing to the periodic nature of surveys. Having a network of regional resource laboratories proficient in conducting the folate microbiologic assay and willing and able to perform service work for other countries will be the most efficient way to create an infrastructure wherein qualified laboratories produce reliable blood folate data. Continuous participation of these laboratories in a certification program can verify and document their proficiency. If the resource laboratories conduct the work on a fee-for-service basis, they could become self-sustaining in the long run. © 2018 This article is a U.S. Government work and is in the public domain in the USA.

  20. Elevated homocysteine levels indicate suboptimal folate status in pediatric sickle cell patients

    NARCIS (Netherlands)

    van der Dijs, FPL; Schnog, JJB; Brouwer, DAJ; Velvis, HJR; van den Berg, GA; Bakker, AJ; Duits, AJ; Muskiet, FD

    1998-01-01

    We investigated whether pediatric patients with sickle cell disease (SCD) (9 +/- 4 years; 27 homozygous SCD [HbSS]; 19 sickle-C disease [HbSC]) have different folate status compared with age-, sex-, and race-matched normal hemoglobin (HbAA) controls (n = 20), and whether their folate status can be

  1. Nutrient Intake Values for Folate during Pregnancy and Lactation Vary Widely around the World

    Directory of Open Access Journals (Sweden)

    Lisa A. Houghton

    2013-09-01

    Full Text Available Folate is a B-vitamin with particular importance during reproduction due to its role in the synthesis and maintenance of DNA. Folate is well known for its role in preventing neural tube defects (NTDs during the periconceptional period. There is also an increased need for folate throughout pregnancy to support optimal growth and development of the fetus and blood volume expansion and tissue growth of the mother. During lactation, women are at risk of folate deficiency due to increased demands to accommodate milk folate levels. Nutrient Intake Values (NIVs for folate have been calculated to take into account additional needs during pregnancy and lactation. However, these values vary widely between countries. For example, the folate requirement that is set to meet the needs of almost all healthy women during pregnancy varies from 300 µg/day in the United Kingdom to 750 µg/day in Mexico. Currently, there is no accepted standardized terminology or framework for establishing NIVs. This article reviews country-specific NIVs for folate during pregnancy and lactation and the basis for setting these reference values.

  2. Ordering folate assays is no longer justified for investigation of anemias, in folic acid fortified countries

    Directory of Open Access Journals (Sweden)

    von Kuster Kenneth

    2010-01-01

    Full Text Available Abstract Background Since 1998, in the countries where there is mandatory fortification of grain products with folic acid, folate deficiency has become very rare. Consequently, we decided to find out whether there is any justification for ordering folate assays for investigation of anemias. Methods We reviewed serum folate (SF and red cell folate (RF data at two teaching hospitals in Canada. At the Health Sciences Centre (HSC the folate data for the year 2001 were analyzed and the medical records of those with low SF or low RF were reviewed. At St. Boniface General Hospital(SBGHall folate data between January 1996 and Dec 31,2004 were analyzed and the medical records of all who had low RF between January 1,1999 and December 31,2004 were reviewed. Results In 2001, at HSC, 11 out of 2154(0.5%SF were low( Conclusion In countries where there is mandatory fortification of grain products with folic acid, folate deficiency to the degree that could cause anemia is extremely rare. Ordering folate assays for investigation of anemias, in these countries, is waste of time and money. The result of these tests is more likely to mislead the physicians than to provide any useful information.

  3. Reduced folate carrier polymorphism determines methotrexate uptake by B cells and CD4+ T cells

    DEFF Research Database (Denmark)

    Baslund, B; Gregers, J; Nielsen, Claus Henrik

    2008-01-01

    To examine if polymorphism 80G --> A in the Reduced Folate Carrier (RFC) affects uptake of MTX in B- and CD4+ T-cells.......To examine if polymorphism 80G --> A in the Reduced Folate Carrier (RFC) affects uptake of MTX in B- and CD4+ T-cells....

  4. Effect modification by population dietary folate on the association between MTHFR genotype, homocysteine, and stroke risk

    DEFF Research Database (Denmark)

    Holmes, Michael V; Newcombe, Paul; Hubacek, Jaroslav A

    2011-01-01

    The MTHFR 677C→T polymorphism has been associated with raised homocysteine concentration and increased risk of stroke. A previous overview showed that the effects were greatest in regions with low dietary folate consumption, but differentiation between the effect of folate and small-study bias wa...

  5. Effects of cultivation conditions on folate production by lactic acid bacteria

    NARCIS (Netherlands)

    Sybesma, W.; Starrenburg, M.; Tijsseling, L.; Hoefnagel, M.H.N.; Hugenholtz, J.

    2003-01-01

    A variety of lactic acid bacteria were screened for their ability to produce folate intracellularly and/or extracellularly. Lactococcus lactis, Streptococcus thermophilus, and Leuconostoc spp. all produced folate, while most Lactobacillus spp., with the exception of Lactobacillus plantarum, were not

  6. Methionine synthase A2756G and reduced folate carrier1 A80G ...

    African Journals Online (AJOL)

    Background: Polymorphisms of genes encoding enzymes involved in folate metabolism have long been hypothesized to be maternal risk factors for Down syndrome, however, results are conflicting and inconclusive. Aim of the study: To analyze the effect of methionine synthase (MTR) A2756G, and reduced folate carrier ...

  7. HIV and other predictors of serum folate, serum ferritin, and hemoglobin in pregnancy

    DEFF Research Database (Denmark)

    Friis, Henrik; Gomo, E; Kæstel, Pernille

    2001-01-01

    BACKGROUND: Folate and iron status and hemoglobin concentrations are important to maternal and infant health. OBJECTIVE: Our goal was to identify predictors of serum folate, serum ferritin, and hemoglobin. DESIGN: This was a cross-sectional study of 1669 pregnant women (22-35 wk of gestation) in ...

  8. The folate hydrolase 1561 C>T polymorphism is associated with depressive symptoms in Puerto Rican adults

    Science.gov (United States)

    Low plasma folate has been associated with depression. Variants of genes involved in the uptake, retention and metabolism of folate have been linked with plasma folate and homocysteine concentrations. It remains unclear whether such variants are also associated with depressive symptoms, directly or ...

  9. Cognitive impairment in folate-deficient rats corresponds to depleted brain phosphatidylcholine and is prevented by methionine without lowering homocysteine

    Science.gov (United States)

    Poor folate status is associated with cognitive decline and dementia in older adults. Although impaired brain methylation activity and homocysteine toxicity are widely believed to account for this association, how folate deficiency impairs cognition is uncertain. To better define the role of folate ...

  10. Folate status, folate-related genes and serum miR-21 expression: Implications for miR-21 as a biomarker

    Directory of Open Access Journals (Sweden)

    Emma Louise Beckett

    2015-12-01

    General significance: This study demonstrates that serum miR-21 expression correlates with folate status and related genetic status. This may have consequences for the proposed use of miR-21 as a colorectal cancer biomarker.

  11. 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.

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

    Science.gov (United States)

    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.

  13. Cysteine peroxidase activity in rat blood plasma | Razygraev ...

    African Journals Online (AJOL)

    The rat plasma found to be able to accelerate greatly the H2O2-dependent oxidation of cysteine. The activity was a characteristic of a protein fraction precipitated at 30—44% ammonium sulfate saturation, and the specific activity in protein fraction was significantly higher than in plasma. Cysteine:H2O2 oxidoreductase ...

  14. Antimalarial effects of vinyl sulfone cysteine proteinase inhibitors.

    OpenAIRE

    Rosenthal, P J; Olson, J E; Lee, G K; Palmer, J T; Klaus, J L; Rasnick, D

    1996-01-01

    We evaluated the antimalarial effects of vinyl sulfone cysteine proteinase inhibitors. A number of vinyl sulfones strongly inhibited falcipain, a Plasmodium falciparum cysteine proteinase that is a critical hemoglobinase. In studies of cultured parasites, nanomolar concentrations of three vinyl sulfones inhibited parasite hemoglobin degradation, metabolic activity, and development. The antimalarial effects correlated with the inhibition of falcipain. Our results suggest that vinyl sulfones or...

  15. Cobalamin speciation using reversed-phase micro-high-performance liquid chromatography interfaced to inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Yanes, Enrique G.; Miller-Ihli, Nancy J.

    2004-01-01

    Micro-high-performance liquid chromatography interfaced to inductively coupled plasma mass spectrometry was optimized for the determination and separation of a mixture of cobalt containing species. Four cobalamin species (cyanocobalamin, hydroxocobalamin, methylcobalamin, and 5'-deoxyadenosylcobalamin) representing the various forms of vitamin B12 as well as the harmful corrinoid analogue cobinamide dicyanide were separated using reversed-phase microcapillary chromatography with columns containing C18 packing material with a 2-μm particle size. Selection of organic solvents for the separation took into consideration compatibility with the inductively coupled plasma mass spectrometer being used for element specific detection. Optimized method conditions included use of a methanol gradient and make-up solution for the nebulizer. Some issues associated with dead volume were overcome by the extension of the gradient program. The total analysis time was 52 min. The column-to-column variability was evaluated and was found to be very reasonable (9% RSD on average), confirming that this method is rugged and that the technology should be easily transferred to other laboratories

  16. 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...

  17. Lysosomal cysteine peptidases - Molecules signaling tumor cell death and survival.

    Science.gov (United States)

    Pišlar, Anja; Perišić Nanut, Milica; Kos, Janko

    2015-12-01

    Lysosomal cysteine peptidases - cysteine cathepsins - are general intracellular protein-degrading enzymes that control also a variety of specific physiological processes. They can trigger irreversible events leading to signal transduction and activation of signaling pathways, resulting in cell survival and proliferation or cell death. In cancer cells, lysosomal cysteine peptidases are involved in multiple processes during malignant progression. Their translocation from the endosomal/lysosomal pathway to nucleus, cytoplasm, plasma membrane and extracellular space enables the activation and remodeling of a variety of tumor promoting proteins. Thus, lysosomal cysteine peptidases interfere with cytokine/chemokine signaling, regulate cell adhesion and migration and endocytosis, are involved in the antitumor immune response and apoptosis, and promote cell invasion, angiogenesis and metastasis. Further, lysosomal cysteine peptidases modify growth factors and receptors involved in tyrosine kinase dependent pathways such as MAPK, Akt and JNK, thus representing key signaling tools for the activation of tumor cell growth and proliferation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Systematic Review of Observational Studies with Dose-Response Meta-Analysis between Folate Intake and Status Biomarkers in Adults and the Elderly

    NARCIS (Netherlands)

    Novaković, Romana; Geelen, Anouk; Ristić-Medić, Danijela; Nikolić, Marina; Souverein, Olga W.; McNulty, Helene; Duffy, Maresa; Hoey, Leane; Dullemeijer, Carla; Renkema, Jacoba M.S.; Gurinović, Mirjana; Glibetić, Marija; Groot, de Lisette C.P.G.M.; ’t Veer, van Pieter

    2018-01-01

    Background: Dietary reference values for folate intake vary widely across Europe. Methods: MEDLINE and Embase through November 2016 were searched for data on the association between folate intake and biomarkers (serum/plasma folate, red blood cell [RBC] folate, plasma homocysteine) from

  19. Electrostatic influence of local cysteine environments on disulfide exchange kinetics.

    Science.gov (United States)

    Snyder, G H; Cennerazzo, M J; Karalis, A J; Field, D

    1981-11-10

    The ionic strength dependence of the bimolecular rate constant for reaction of the negative disulfide 5,5'-dithiobis (2-nitrobenzoic acid) with cysteines in fragments of naturally occurring proteins was determined by stopped-flow spectroscopy. The Debye-Hückel relationship was applied to determine the effective charge at the cysteine and thereby determine the extent to which nearby neighbors in the primary sequence influence the kinetics. Corrections for the secondary salt effect on cysteine pKs were determined by direct spectrometric pH titration of sulfhydryl groups or by observation of the ionic strength dependence of kinetics of cysteine reaction with the neutral disulfide 2,2'-dithiodipyridine. Quantitative expressions was verified by model studies with N-acetyl-cystein. At ionic strengths equal to or greater than 20 mM, the net charge at the polypeptide cysteine site is the sum of the single negative charge of the thiolate anion and the charges of the amino acids immediately preceding and following the cysteine in the primary sequence. At lower ionic strengths, more distant residues influence kinetics. At pH 7.0, 23 degree C, and an ionic strength of 20 mM, rate constants for reaction of the negative disulfide with a cysteine having two positive neighbors, one positive and one neutral neighbor, or two neutral neighbors are 132000, 3350, and 367 s-1 M-1, respectively. This corresponds to a contribution to the activation energy of 0.65- 1.1 kcal/mol per ion pair involved in collision between the cysteine and disulfide regions. The results permit the estimation that cysteine local environments may provide a means of achieving a 10(6)-fold range in rate constants in disulfide exchange reactions in random-coil proteins. This range may prove useful in developing strategies for directing disulfide pairing in synthetic proteins.

  20. Cysteine sulfoxide derivatives in Petiveria alliacea.

    Science.gov (United States)

    Kubec, R; Musah, R A

    2001-11-01

    Two diastereomers of S-benzyl-L-cysteine sulfoxide have been isolated from fresh roots of Petiveria alliacea. Their structures and absolute configurations have been determined by NMR, MALDI-HRMS, IR and CD spectroscopy and confirmed by comparison with authentic compounds. Both the R(S) and S(S) diastereomers of the sulfoxide are present in all parts of the plant (root, stem, and leaves) with the latter diastereomer being predominant. Their total content greatly varied in different parts of the plant between 0.07 and 2.97 mg g(-1) fr. wt, being by far the highest in the root. S-Benzylcysteine has also been detected in trace amounts (<10 microg g(-1) fr. wt) in all parts of the plant. This represents the first report of the presence of S-benzylcysteine derivatives in nature.

  1. Retaining in-gel zymographic activity of cysteine proteases via a cysteine-supplemented running buffer.

    Science.gov (United States)

    Vootukuri Reddy, Sreekanth; Philpott, Mike P; Trigiante, Giuseppe

    2016-10-01

    Zymography is a powerful technique to separate and identify different enzymatic activities on a standard acrylamide gel. For oxidation prone enzymes such as cysteine proteases however, the oxidizing species generated by electrolysis of the gel running buffer may result in partial or complete inactivation, thus compromising the final readout. This can be only partially remedied by subsequent treatment of the gel with reducing agents. We demonstrate the generation of reactive oxidizing species during electrophoresis and discovered that supplementation of the gel running buffer with a minimum of 5 mM cysteine prevents enzyme inactivation and allows retention of proteolytic activity as measured by zymography on model substrate N α-benzoyl-l-arginine p-nitroanilide, without at the same time altering the mobilities of the gel proteins. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Simultaneous electrochemical determination of L-cysteine and L-cysteine disulfide at carbon ionic liquid electrode.

    Science.gov (United States)

    Safavi, Afsaneh; Ahmadi, Raheleh; Mahyari, Farzaneh Aghakhani

    2014-04-01

    A linear sweep voltammetric method is used for direct simultaneous determination of L-cysteine and L-cysteine disulfide (cystine) based on carbon ionic liquid electrode. With carbon ionic liquid electrode as a high performance electrode, two oxidation peaks for L-cysteine (0.62 V) and L-cysteine disulfide (1.3 V) were observed with a significant separation of about 680 mV (vs. Ag/AgCl) in phosphate buffer solution (pH 6.0). The linear ranges were obtained as 1.0-450 and 5.0-700 μM and detection limits were estimated to be 0.298 and 4.258 μM for L-cysteine and L-cysteine disulfide, respectively. This composite electrode was applied for simultaneous determination of L-cysteine and L-cysteine disulfide in two real samples, artificial urine and nutrient broth. Satisfactory results were obtained which clearly indicate the applicability of the proposed electrode for simultaneous determination of these compounds in complex matrices.

  3. CHARACTERIZATION OF DANSYLATED CYSTEINE, GLUTATHIONE DISULFIDE, CYSTEINE AND CYSTINE BY NARROW BORE LIQUID CHROMATOGRAPHY/ELECTROSPRAY IONIZATION MASS SPECTROMETRY

    Science.gov (United States)

    A method using reversed phase high performance liquid chromatography/electrospray ionization-mass spectrometric (RP-LC/ESI-MS) method has been developed to confirm the identity of dansylated derivatives of cysteine and glutathione, and their respective dimers. Cysteine, GSH, CSSC...

  4. Folate targeted polymeric 'green' nanotherapy for cancer

    Energy Technology Data Exchange (ETDEWEB)

    Narayanan, Sreeja; Binulal, N S; Mony, Ullas; Manzoor, Koyakutty; Nair, Shantikumar; Menon, Deepthy, E-mail: deepthymenon@aims.amrita.edu [Amrita Center for Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham, Kochi-682 041, Kerala (India)

    2010-07-16

    The concept of 'green' chemotherapy by employing targeted nanoparticle mediated delivery to enhance the efficacy of phytomedicines is reported. Poly (lactide-co-glycolide) (PLGA) nanoparticles encapsulating a well known nutraceutical namely, grape seed extract (GSE)-'NanoGSE'-was prepared by a nanoprecipitation technique. The drug-loaded nanoparticles of size {approx} 100 nm exhibited high colloidal stability at physiological pH. Molecular receptor targeting of this nanophytomedicine against folate receptor over-expressing cancers was demonstrated in vitro by conjugation with a potential cancer targeting ligand, folic acid (FA). Fluorescence microscopy and flow cytometry data showed highly specific cellular uptake of FA conjugated NanoGSE on folate receptor positive cancer cells. Studies were also conducted to investigate the efficiency of targeted (FA conjugated) versus non-targeted (non-FA conjugated) nanoformulations in causing cancer cell death. The IC{sub 50} values were lowered by a factor of {approx} 3 for FA-NanoGSE compared to the free drug, indicating substantially enhanced bioavailability to the tumor cells, sparing the normal ones. Receptor targeting of FA-NanoGSE resulted in a significant increase in apoptotic index, which was also quantified by flow cytometry and fluorescence microscopy. This in vitro study provides a basis for the use of nanoparticle mediated delivery of anticancer nutraceuticals to enhance bioavailability and effectively target cancer by a 'green' approach.

  5. Folate Receptor Targeted Alpha-Therapy Using Terbium-149

    CERN Document Server

    Müller, Cristina; Haller, Stephanie; Dorrer, Holger; Köster, Ulli; Johnston, Karl; Zhernosekov, Konstantin; Türler, Andreas; Schibli, Roger

    2014-01-01

    Terbium-149 is among the most interesting therapeutic nuclides for medical applications. It decays by emission of short-range α-particles (Eα = 3.967 MeV) with a half-life of 4.12 h. The goal of this study was to investigate the anticancer efficacy of a 149Tb-labeled DOTA-folate conjugate (cm09) using folate receptor (FR)-positive cancer cells in vitro and in tumor-bearing mice. 149Tb was produced at the ISOLDE facility at CERN. Radiolabeling of cm09 with purified 149Tb resulted in a specific activity of ~1.2 MBq/nmol. In vitro assays performed with 149Tb-cm09 revealed a reduced KB cell viability in a FR-specific and activity concentration-dependent manner. Tumor-bearing mice were injected with saline only (group A) or with 149Tb-cm09 (group B: 2.2 MBq; group C: 3.0 MBq). A significant tumor growth delay was found in treated animals resulting in an increased average survival time of mice which received 149Tb-cm09 (B: 30.5 d; C: 43 d) compared to untreated controls (A: 21 d). Analysis of blood parameters rev...

  6. Folate content in tomato ( Lycopersicon esculentum ). influence of cultivar, ripeness, year of harvest, and pasteurization and storage temperatures.

    Science.gov (United States)

    Iniesta, M Dolores; Pérez-Conesa, Darío; García-Alonso, Javier; Ros, Gaspar; Periago, M Jesús

    2009-06-10

    The effects of cultivar, on-vine ripening, and year of harvest on the folate content of raw tomatoes were studied. Folate content in hot-break tomato puree (HTP) subjected to pasteurization at different temperatures and its evolution during the shelf life of tomato juice were also investigated. 5-Methyltetrahydrofolate (5-CH(3)-H(4)-folate) was the only folate compound identified in raw tomatoes and HTP, but tetrahydrofolate (H(4)-folate) was 10% of the folate detected in tomato juice. The content of folates in raw tomatoes ranged from 4.1 to 35.3 microg/100 g of fresh weight and was highly influenced by all of the factors studied. No clear trend of folate content with ripening stage was observed. The extractability of 5-CH(3)-H(4)-folate from HTP increased significantly after pasteurization at 98 degrees C for 40 s, but higher temperatures decreased its content. Tomato juice showed folate losses during storage independent of the storage temperature. Folate losses were higher when tomato juice was packed in glass bottles than in Tetra Pak.

  7. Improved Stable Isotope Dilution Assay for Dietary Folates Using LC-MS/MS and Its Application to Strawberries

    Directory of Open Access Journals (Sweden)

    Lisa Striegel

    2018-02-01

    Full Text Available Folates play an important role in the human body and a deficiency of this vitamin can cause several diseases. Therefore, a reliable analytical method is crucial for the determination of folate vitamers in strawberries and other dietary folate sources. A stable isotope dilution LC-MS/MS method for analyzing folates in food was developed and validated. The folate vitamers Pteroylmonoglutamic acid, tetrahydrofolate, 5-methyltetrahydrofolate, and 5-formyltetrahydrofolate were quantified using 13C-labeled internal standards. Validation of the assay was accomplished by determining linearity, precision, recovery, limit of detection, and limit of quantification and revealed to be a precise, sensitive, and accurate method to determine folate vitamers. Strawberries are worldwide consumed and known to be a good dietary source of nutritive compounds. Using this method, folate concentrations in selected commercial strawberry cultivars and experimental breeding lines grown in Germany and Australia were investigated. Total folates varied from 59 to 153 μg/100 g on fresh weight basis. Furthermore, folate content after lyophilizing or freezing did not show any significant differences compared to fresh strawberries. However, significant losses of total folates in pureed strawberries could be observed after 5 days of storage with only 16% of the original concentration retained. In summary, some of the investigated strawberry cultivars/breeding lines can be considered as rich dietary sources of natural folates.

  8. Improved stable isotope dilution assay for dietary folates using LC-MS/MS and its application to strawberries

    Science.gov (United States)

    Striegel, Lisa; Chebib, Soraya; Netzel, Michael E.; Rychlik, Michael

    2018-02-01

    Folates play an important role in the human body and a deficiency of this vitamin can cause several diseases. Therefore, a reliable analytical method is crucial for the determination of folate vitamers in strawberries and other dietary folate sources. A stable isotope dilution LC-MS/MS method for analyzing folates in food was developed and validated. The folate vitamers Pteroylmonoglutamic acid, tetrahydrofolate, 5-methyltetrahydrofolate and 5-formyltetrahydrofolate were quantified using 13C-labelled internal standards. Validation of the assay was accomplished by determining linearity, precision, recovery, limit of detection and limit of quantification and revealed to be a precise, sensitive and accurate method to determine folate vitamers. Strawberries are worldwide consumed and known to be a good dietary source of nutritive compounds. Using this method, folate concentrations in selected commercial strawberry cultivars and experimental breeding lines grown in Germany were investigated. Total folates varied from 59 to 153 µg/100 g on fresh weight basis. Furthermore, folate content after lyophilizing or freezing did not show any significant differences compared to fresh strawberries. However, significant losses of total folates in pureed strawberries could be observed after 5 days of storage with only 16 % of the original concentration retained. In summary, some of the investigated strawberry cultivars/breeding lines can be considered as rich dietary sources of natural folates.

  9. The role of cysteine residues in the sulphate transporter, SHST1: construction of a functional cysteine-less transporter.

    Science.gov (United States)

    Howitt, Susan M

    2005-05-20

    We investigated the role of cysteine residues in the sulphate transporter, SHST1, with the aim of generating a functional cysteine-less variant. SHST1 contains five cysteine residues and none was essential for function. However, replacement of C421 resulted in a reduction in transport activity. Sulphate transport by C205 mutants was dependent on the size of the residue at this position. Alanine at position 205 resulted in a complete loss of function whereas leucine resulted in a 3-fold increase in sulphate transport relative to wild type SHST1. C205 is located in a putative intracellular loop and our results suggest that this loop may be important for sulphate transport. By replacing C205 with leucine and the other four cysteine residues with alanine, we constructed a cysteine-less variant of SHST1 that has transport characteristics indistinguishable from wild type. This construct will be useful for further structure and function studies of SHST1.

  10. Design and optimization of novel paclitaxel-loaded folate-conjugated amphiphilic cyclodextrin nanoparticles.

    Science.gov (United States)

    Erdoğar, Nazlı; Esendağlı, Güneş; Nielsen, Thorbjorn T; Şen, Murat; Öner, Levent; Bilensoy, Erem

    2016-07-25

    As nanomedicines are gaining momentum in the therapy of cancer, new biomaterials emerge as alternative platforms for the delivery of anticancer drugs with bioavailability problems. In this study, two novel amphiphilic cyclodextrins (FCD-1 and FCD-2) conjugated with folate group to enable active targeting to folate positive breast tumors were introduced. The objective of this study was to develop and characterize new folated-CD nanoparticles via 3(2) factorial design for optimal final parameters. Full physicochemical characterization studies were performed. Blank and paclitaxel loaded FCD-1 and FCD-2 nanoparticles remained within the range of 70-275nm and 125-185nm, respectively. Zeta potential values were neutral and -20mV for FCD-1 and FCD-2 nanoparticles, respectively. Drug release studies showed initial burst release followed by a longer sustained release. Blank nanoparticles had no cytotoxicity against L929 cells. T-47D and ZR-75-1 human breast cancer cells with different levels of folate receptor expression were used to assess anti-cancer efficacy. Through targeting the folate receptor, these nanoparticles were efficiently engulfed by the breast cancer cells. Additionally, breast cancer cells became more sensitive to cytotoxic and/or cytostatic effects of PCX delivered by FCD-1 and FCD-2. In conclusion, these novel folate-conjugated cyclodextrin nanoparticles can therefore be considered as promising alternative systems for safe and effective delivery of paclitaxel with a folate-dependent mechanism. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Efficacy and Stability studies of microbial folate fortified fruit juices prepared using probiotic microorganism.

    Science.gov (United States)

    Deep, S; Ojha, S; Kundu, S

    2017-07-31

    Folate, natural form of water soluble vitamin folic acid, is significant for humans as involved in most important metabolic reactions i.e. nucleotide synthesis and amino acid inter conversions. Thus its deficiency causes neural tube defects in newborns and cardiovascular diseases, and cancers. Humans cannot synthesize folate de novo so consumption through diet is essential. Natural food sources, supplements and fortified food products are the choices available to complete the Daily recommended intake. However microbial fortification using probiotics recently gained wide attention due to dual advantage of natural food matrix with enhanced folate content along with the probiotics benefits. Current study was focused on the microbial fortification of fruit juices and their efficacy and stability studies. Freshly filtered orange and tomato juice was prepared and inoculated with Streptococcus thermophilus NCIM 2904. Incubation was done at 40°C and samples were collected at different time interval. Folate extraction was done using human plasma and content was measured by microbiological assay using Lactobacillus casei NCIM No. 2364. Efficacy and stability studies were carried out to ensure the quality of juices to be consumed in terms of folate content, viable cell count and pH after 4 weeks of storage at low temperature. Positive results were observed as folate content was quite stable whereas viable cell count was also found to be significant till some time without adding any preservatives. The results indicated that fortified fruit juices could be used as probiotic beverages with enhanced folate content.

  12. Folates stability in two types of rye breads during processing and frozen storage.

    Science.gov (United States)

    Gujska, Elzbieta; Michalak, Joanna; Klepacka, Joanna

    2009-06-01

    High-performance liquid chromatography was used to study the stability of folate vitamers in two types of rye breads after baking and 16 weeks of frozen storage. Bread made using sourdough seeds contained less total folate (74.6 microg/100 g dry basis, expressed as folic acid) than the whole rye flour (79.8 microg/100 g dry basis) and bread leavened only with baker's yeast (82.8 microg/100 g dry basis). Most importantly, it was generated by a significant decrease in 5-CH3-H4folate form. The baking process caused some changes in folate distribution. Storage of breads at -18 degrees C for 2 weeks did not have a significant effect (p type of breads. After a longer period of storage (16 weeks), a 25% loss of folates in the bread made with baker's yeast and a 38% loss in the bread fermented with sourdough seeds was found. Retention of 5-CH3-H4folate and 10-HCO-H2folate forms were much lower in the bread made with a sourdough addition than with baker's yeast only.

  13. Evaluation of serum homocysteine, high-sensitivity CRP, and RBC folate in patients with alopecia areata

    Directory of Open Access Journals (Sweden)

    Maryam Yousefi

    2014-01-01

    Full Text Available Introduction: Alopecia areata (AA is a common type of hair loss with an autoimmune basis. As the role of homocysteine (Hcys, folate, and CRP has been considered in some autoimmune diseases. Objectives: To evaluate homocysteine, folate and CRP level in AA. Methods: This study was performed on 29 patients who had AA for at least 6 months affecting more than 20% of scalp, and 32 healthy controls. Levels of serum Hcys, blood high-sensitivity CRP, and RBC folate were measured in all subjects. Results: The mean level of RBC folate was significantly lower in the patient group than that in controls (P < 0.001. Also, the level of RBC folate was significantly lower in patients with extensive forms of disease (alopecia totalis/alopecia universalis in comparison with more localized form (patchy hair loss (P < 0.05. Patients with higher "Severity of Alopecia Total" (SALT score had lower RBC folate, as well. Serum Hcys and blood high-sensitivity CRP levels did not show a significant difference in two groups. Conclusion: Patients with alopecia areata have lower level of RBC folate which is in negative correlation with both severity and extension of AA.

  14. Association of Folate Level in Blood with the Risk of Schizophrenia.

    Science.gov (United States)

    Ding, Yujie; Ju, Mingliang; He, Lin; Chen, Wenzhong

    2017-01-01

    The aim of this study was to evaluate the association between folate level and the risk of schizophrenia and to identify possible biomarker for schizophrenia. Data about folate were extracted from 16 high quality studies. The association of folate level in blood and schizophrenia was evaluated using standardized mean difference (SMD) and 95% confidence interval (CI). Totally 1183 (52.1%) cases and 1089 (47.9%) controls were included in the current metaanalysis. Folate level in schizophrenia patients was significantly lower than that in healthy controls (SMD= -0.65; 95% CI: [-0.86, -0.45]; P 0.05). Sensitivity analysis confirmed that these results were stable and reliable, no publication bias existed in our meta-analysis based on Egger's and Begg's tests (P=0.48 and 0.30, respectively). These results suggest that decreased folate may be a risk factor for schizophrenia. More epidemiological and biochemistry studies are required to describe how folate or folate supplementation play roles in the progress of schizophrenia. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  15. Solar cycle predicts folate-sensitive neonatal genotypes at discrete phases of the first trimester of pregnancy: a novel folate-related human embryo loss hypothesis.

    Science.gov (United States)

    Lucock, Mark; Glanville, Tracey; Yates, Zoë; Walker, James; Furst, John; Simpson, Nigel

    2012-08-01

    Folate, a key periconceptional nutrient, is ultraviolet light (UV-R) sensitive. We therefore hypothesise that a relationship exists between sunspot activity, a proxy for total solar irradiance (particularly UV-R) reaching Earth, and the occurrence of folate-sensitive, epigenomic-related neonatal genotypes during the first trimester of pregnancy. Limited data is provided to support the hypothesis that the solar cycle predicts folate-related human embryo loss: 379 neonates born at latitude 54°N between 1998 and 2000 were examined for three folate-sensitive, epigenome-related polymorphisms, with solar activity for trimester one accessed via the Royal Greenwich Observatory-US Air force/National Oceanic and Atmospheric Administration Sunspot Database (34,110 total observation days). Logistic regression showed solar activity predicts C677T-methylenetetrahydrofolate reductase (C677T-MTHFR) and A66G-methionine synthase reductase (A66G-MSR) genotype at discrete phases of trimester one. Total and maximal sunspot activity predicts C677T-MTHFR genotype for days 31-60 of trimester one (p=0.0181 and 0.0366, respectively) and A66G-MSR genotype for days 61-90 of trimester one (p=0.0072 and 0.0105, respectively). Loss of UV-R sensitive folate associated with the sunspot cycle might therefore interact with variant folate genes to perturb DNA methylation and/or elaboration of the primary base sequence (thymidylate synthesis), as well as increase embryo-toxic homocysteine. We hypothesise that this may influence embryo viability leading to 677CC-MTHFR and 66GG-MSR embryo loss at times of increased solar activity. This provides an interesting and plausible link between well recognised 'folate gene originated developmental disorders' and 'solar activity/seasonality modulated developmental disorders'. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Interaction between cytotoxic effects of γ-radiation and folate deficiency in relation to choline reserves

    International Nuclear Information System (INIS)

    Batra, Vipen; Devasagayam, Thomas Paul Asir

    2009-01-01

    The search for non-toxic radio-protective drugs has yielded many potential agents but most of these compounds have certain amount of toxicity. Recent studies have indicated that bio-molecules such as folate and choline might be of radio-protective value as they are, within broad dose ranges, non-toxic to humans and experimental animals. The objective of the present study was to investigate choline dependent adaptive response to potential synergistic cytotoxic effect of folate deficiency and γ-radiation. Male Swiss mice maintained on folate sufficient diet (FSD) and folate free diet (FFD) based on AIN-93 M formula, were subjected to 1-4 Gy total body γ-irradiation. To investigate liver DNA damage, apurinic/apyrimidinic sites (AP sites) were quantified. A significant increase in liver DNA AP sites with concomitant depletion of liver choline reserves was observed when γ-radiation was combined with folate deficiency. Further work in this direction suggested that cytotoxic interaction between folate deficiency and gamma radiation might induce utilization of choline and choline containing moieties by modifying levels of key regulatory enzymes dihydrofolate reductase (DHFR) and choline oxidase (ChoOx). Another major finding of these studies is that significant liver damage at higher doses of radiation (3-4 Gy), might release considerable amounts of choline reserves to serum. In conclusion, a plausible interpretation of the present studies is that folate deprivation and γ-radiation interact to mobilize additional choline reserves of hepatic tissue, for redistribution to other organs, which could not be utilized by folate deficiency alone. Present results clearly indicated a distinct choline pool in liver and kidney tissues that could be utilized by folate deficient animals only under radiation stress conditions

  17. Probes of the catalytic site of cysteine dioxygenase.

    Science.gov (United States)

    Chai, Sergio C; Bruyere, John R; Maroney, Michael J

    2006-06-09

    The first major step of cysteine catabolism, the oxidation of cysteine to cysteine sulfinic acid, is catalyzed by cysteine dioxygenase (CDO). In the present work, we utilize recombinant rat liver CDO and cysteine derivatives to elucidate structural parameters involved in substrate recognition and x-ray absorption spectroscopy to probe the interaction of the active site iron center with cysteine. Kinetic studies using cysteine structural analogs show that most are inhibitors and that a terminal functional group bearing a negative charge (e.g. a carboxylate) is required for binding. The substrate-binding site has no stringent restrictions with respect to the size of the amino acid. Lack of the amino or carboxyl groups at the alpha-carbon does not prevent the molecules from interacting with the active site. In fact, cysteamine is shown to be a potent activator of the enzyme without being a substrate. CDO was also rendered inactive upon complexation with the metal-binding inhibitors azide and cyanide. Unlike many non-heme iron dioxygenases that employ alpha-keto acids as cofactors, CDO was shown to be the only dioxygenase known to be inhibited by alpha-ketoglutarate.

  18. L-Cysteine metabolism and its nutritional implications.

    Science.gov (United States)

    Yin, Jie; Ren, Wenkai; Yang, Guan; Duan, Jielin; Huang, Xingguo; Fang, Rejun; Li, Chongyong; Li, Tiejun; Yin, Yulong; Hou, Yongqing; Kim, Sung Woo; Wu, Guoyao

    2016-01-01

    L-Cysteine is a nutritionally semiessential amino acid and is present mainly in the form of L-cystine in the extracellular space. With the help of a transport system, extracellular L-cystine crosses the plasma membrane and is reduced to L-cysteine within cells by thioredoxin and reduced glutathione (GSH). Intracellular L-cysteine plays an important role in cellular homeostasis as a precursor for protein synthesis, and for production of GSH, hydrogen sulfide (H(2)S), and taurine. L-Cysteine-dependent synthesis of GSH has been investigated in many pathological conditions, while the pathway for L-cysteine metabolism to form H(2)S has received little attention with regard to prevention and treatment of disease in humans. The main objective of this review is to highlight the metabolic pathways of L-cysteine catabolism to GSH, H(2)S, and taurine, with special emphasis on therapeutic and nutritional use of L-cysteine to improve the health and well-being of animals and humans. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Overexpression of Catalase Diminishes Oxidative Cysteine Modifications of Cardiac Proteins.

    Directory of Open Access Journals (Sweden)

    Chunxiang Yao

    Full Text Available Reactive protein cysteine thiolates are instrumental in redox regulation. Oxidants, such as hydrogen peroxide (H2O2, react with thiolates to form oxidative post-translational modifications, enabling physiological redox signaling. Cardiac disease and aging are associated with oxidative stress which can impair redox signaling by altering essential cysteine thiolates. We previously found that cardiac-specific overexpression of catalase (Cat, an enzyme that detoxifies excess H2O2, protected from oxidative stress and delayed cardiac aging in mice. Using redox proteomics and systems biology, we sought to identify the cysteines that could play a key role in cardiac disease and aging. With a 'Tandem Mass Tag' (TMT labeling strategy and mass spectrometry, we investigated differential reversible cysteine oxidation in the cardiac proteome of wild type and Cat transgenic (Tg mice. Reversible cysteine oxidation was measured as thiol occupancy, the ratio of total available versus reversibly oxidized cysteine thiols. Catalase overexpression globally decreased thiol occupancy by ≥1.3 fold in 82 proteins, including numerous mitochondrial and contractile proteins. Systems biology analysis assigned the majority of proteins with differentially modified thiols in Cat Tg mice to pathways of aging and cardiac disease, including cellular stress response, proteostasis, and apoptosis. In addition, Cat Tg mice exhibited diminished protein glutathione adducts and decreased H2O2 production from mitochondrial complex I and II, suggesting improved function of cardiac mitochondria. In conclusion, our data suggest that catalase may alleviate cardiac disease and aging by moderating global protein cysteine thiol oxidation.

  20. Subcellular distribution of glutathione and cysteine in cyanobacteria.

    Science.gov (United States)

    Zechmann, Bernd; Tomasić, Ana; Horvat, Lucija; Fulgosi, Hrvoje

    2010-10-01

    Glutathione plays numerous important functions in eukaryotic and prokaryotic cells. Whereas it can be found in virtually all eukaryotic cells, its production in prokaryotes is restricted to cyanobacteria and proteobacteria and a few strains of gram-positive bacteria. In bacteria, it is involved in the protection against reactive oxygen species (ROS), osmotic shock, acidic conditions, toxic chemicals, and heavy metals. Glutathione synthesis in bacteria takes place in two steps out of cysteine, glutamate, and glycine. Cysteine is the limiting factor for glutathione biosynthesis which can be especially crucial for cyanobacteria, which rely on both the sufficient sulfur supply from the growth media and on the protection of glutathione against ROS that are produced during photosynthesis. In this study, we report a method that allows detection and visualization of the subcellular distribution of glutathione in Synechocystis sp. This method is based on immunogold cytochemistry with glutathione and cysteine antisera and computer-supported transmission electron microscopy. Labeling of glutathione and cysteine was restricted to the cytosol and interthylakoidal spaces. Glutathione and cysteine could not be detected in carboxysomes, cyanophycin granules, cell walls, intrathylakoidal spaces, periplasm, and vacuoles. The accuracy of the glutathione and cysteine labeling is supported by two observations. First, preadsorption of the antiglutathione and anticysteine antisera with glutathione and cysteine, respectively, reduced the density of the gold particles to background levels. Second, labeling of glutathione and cysteine was strongly decreased by 98.5% and 100%, respectively, in Synechocystis sp. cells grown on media without sulfur. This study indicates a strong similarity of the subcellular distribution of glutathione and cysteine in cyanobacteria and plastids of plants and provides a deeper insight into glutathione metabolism in bacteria.

  1. Effect of (L)-cysteine on acetaldehyde self-administration.

    Science.gov (United States)

    Peana, Alessandra T; Muggironi, Giulia; Fois, Giulia R; Zinellu, Manuel; Sirca, Donatella; Diana, Marco

    2012-08-01

    Acetaldehyde (ACD), the first metabolite of ethanol, has been implicated in several behavioural actions of alcohol, including its reinforcing effects. Recently, we reported that l-cysteine, a sequestrating agent of ACD, reduced oral ethanol self-administration and that ACD was orally self-administered. This study examined the effects of l-cysteine pre-treatment during the acquisition and maintenance phases of ACD (0.2%) self-administration as well as on the deprivation effect after ACD extinction and on a progressive ratio (PR) schedule of reinforcement. In a separate PR schedule of reinforcement, the effect of l-cysteine was assessed on the break-point produced by ethanol (10%). Furthermore, we tested the effect of l-cysteine on saccharin (0.2%) reinforcement. Wistar rats were trained to self-administer ACD by nose poking on a fixed ratio (FR1) schedule in 30-min daily sessions. Responses on an active nose-poke caused delivery of ACD solution, whereas responses on an inactive nose-poke had no consequences. l-cysteine reduced the acquisition (40 mg/kg), the maintenance and the deprivation effect (100 mg/kg) of ACD self-administration. Furthermore, at the same dose, l-cysteine (120 mg/kg) decreased both ACD and ethanol break point. In addition, l-cysteine was unable to suppress the different responses for saccharin, suggesting that its effect did not relate to an unspecific decrease in a general motivational state. Compared to saline, l-cysteine did not modify responses on inactive nose-pokes, suggesting an absence of a non-specific behavioural activation. Taken together, these results could support the hypotheses that ACD possesses reinforcing properties and l-cysteine reduces motivation to self-administer ACD. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. 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

  3. A Prospective, Placebo-Controlled Pilot Evaluation of the Effect of Omeprazole on Serum Calcium, Magnesium, Cobalamin, Gastrin Concentrations, and Bone in Cats.

    Science.gov (United States)

    Gould, E; Clements, C; Reed, A; Giori, L; Steiner, J M; Lidbury, J A; Suchodolski, J S; Brand, M; Moyers, T; Emery, L; Tolbert, M K

    2016-05-01

    Chronic proton pump inhibitor administration has been associated with electrolyte and cobalamin deficiency, disrupted bone homeostasis, hypergastrinemia, and rebound acid hypersecretion in humans. It is unknown if this occurs in cats. Prolonged oral omeprazole results in altered bone mineral density or content, serum calcium, magnesium, cobalamin, and gastrin concentrations in healthy cats. Six healthy adult DSH cats. In a within subjects, before and after design, cats received placebo followed by omeprazole (0.83-1.6 mg/kg PO q12h) for 60 days each. Analysis of serum calcium, magnesium, cobalamin, and gastrin concentrations was performed on days 0, 30, and 60. Bone density and content were evaluated on days 0 and 60 of each intervention. Continuous data were analyzed using a two-way ANOVA (α = 0.006). On day 60 of omeprazole administration, continuous intragastric pH monitoring was performed in 2 cats to evaluate the effects of abrupt withdrawal of omeprazole. No significant changes were detected between treatments for any variables, except serum gastrin, which was significantly higher during omeprazole treatment in comparison to placebo (P = 0.002). Evidence of gastric hyperacidity was seen in both cats in which intragastric pH monitoring was performed following cessation of omeprazole. Although further studies with larger populations of cats will be needed to draw any definitive conclusions, these preliminary results suggest that prolonged PPI treatment results in hypergastrinemia and abrupt PPI withdrawal might result in RAH in cats. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  4. A Frameshift Mutation in the Cubilin Gene (CUBN) in Border Collies with Imerslund-Gräsbeck Syndrome (Selective Cobalamin Malabsorption)

    Science.gov (United States)

    Owczarek-Lipska, Marta; Jagannathan, Vidhya; Drögemüller, Cord; Lutz, Sabina; Glanemann, Barbara

    2013-01-01

    Imerslund-Gräsbeck syndrome (IGS) or selective cobalamin malabsorption has been described in humans and dogs. IGS occurs in Border Collies and is inherited as a monogenic autosomal recessive trait in this breed. Using 7 IGS cases and 7 non-affected controls we mapped the causative mutation by genome-wide association and homozygosity mapping to a 3.53 Mb interval on chromosome 2. We re-sequenced the genome of one affected dog at ∼10× coverage and detected 17 non-synonymous variants in the critical interval. Two of these non-synonymous variants were in the cubilin gene (CUBN), which is known to play an essential role in cobalamin uptake from the ileum. We tested these two CUBN variants for association with IGS in larger cohorts of dogs and found that only one of them was perfectly associated with the phenotype. This variant, a single base pair deletion (c.8392delC), is predicted to cause a frameshift and premature stop codon in the CUBN gene. The resulting mutant open reading frame is 821 codons shorter than the wildtype open reading frame (p.Q2798Rfs*3). Interestingly, we observed an additional nonsense mutation in the MRC1 gene encoding the mannose receptor, C type 1, which was in perfect linkage disequilibrium with the CUBN frameshift mutation. Based on our genetic data and the known role of CUBN for cobalamin uptake we conclude that the identified CUBN frameshift mutation is most likely causative for IGS in Border Collies. PMID:23613799

  5. Cobalamin (Vitamin B12) Role on the Biochemical, Histological and Teratological Changes Induced in Diabetic Irradiated Pregnant Rats

    International Nuclear Information System (INIS)

    Ramadan, F.L.

    2013-01-01

    Vitamin B 12 called Cobalamin, is a water soluble vitamin with a key role in the normal function of the brain, nervous system, cell division and for the formation of blood. It is normally involved in the metabolism of every cell of the human body especially affecting DNA synthesis and regulation, fatty acid synthesis and energy production.The aim of the present study was to evaluate the role of vitamin B 12 intake on radiation induced damage in diabetic mothers.Diabetes was induced in female rats by intra-peritoneal injection of alloxan 150 mg/kg b.wt. dissolved in saline. Pregnant diabetic mothers were received vitamin B 12 0.1 mg/100 g b.wt. from the 1st up to 19th day of gestation. Meanwhile, pregnant diabetic rats were exposed to 0.6 Gy on the 7th and the 14th days of gestation. The increased incidence of malformations in diabetic pregnancy with an excess of free oxygen radicals in the embryos was recorded .Vitamin B12 supplementation to diabetic mother ameliorated radiation-induced damage which was obvious by diminishing the increase in glucose level, improving serum insulin level, glycogen content in the liver and ameliorating the decrease in glutathione (GSH) content in the liver of pregnant rats and their fetuses.In addition, vitamin B 12 treatment improved the decrease in red blood cells (RBCs), white blood cells (WBCs) and hemoglobin (Hb) of fetuses and DNA content in the liver tissues. Moreover, vitamin B 12 treatment lead to the regeneration of normal architecture of maternal and fetuses hepatic cells and blood vessels. It could be concluded that vitamin B 12 supplementation to diabetic mothers ameliorated the radiation effect which induced biochemical, histochemical, histological and teratological disorders.Furthermore, the results obtained showed that vitamin B 12 administration caused a protection to diabetic pregnant rats against embryo malformations induced by gamma rays

  6. A novel radioassay for the determination of folate in serum and red cells and new observations on the stability of serum folate

    International Nuclear Information System (INIS)

    Lynch, E.P.J.; Tovey, K.C.; Guilford, H.

    1977-01-01

    A Competitive Protein Binding assay for the determination of folate in serum and red cells has been developed. The assay has been fully validated in hospital trials and comparisons have been made with the microbiological assay. We have based the standardization of the radioassay on N 5 -methyltetrahydrofolate (N 5 -MTHF) as this is the predominant folate derivative in serum samples. At about pH 9.5 pteroylglutamic acid (PGA) and N 5 -MTHF demonstrate the same affinity for folate binding proteins. Therefore, many folate assays have adopted PGA largely because of the popular belief that N 5 -MTHF is highly unstable. However, we have demonstrated that N 5 -MTHF in serum standards is surprisingly stable at -20 0 C. All the reagents for the assay (including the N 5 -MTHF standards) have shown perfectly acceptable stability, permitting their storage for at least three weeks at -20 0 C and one week at 4 0 C. Evidence will be presented to support the use of N 5 -MTHF as being the more appropriate standard. Folate in human serum samples is stable even at room temperature in the presence of 0.1% sodium azide. (orig./AJ) [de

  7. Thiamine absorption is not compromised in folate-deficient rats

    International Nuclear Information System (INIS)

    Walzem, R.L.; Clifford, A.J.

    1988-01-01

    Thiamine absorption and excretion were assessed in rats with severe folate deficiency (FD) by determining the fate of oral 3 H-labeled and intravenous 14 C-labeled thiamine over a 6-h test period. Thiamine status was evaluated in these same rats by measuring transketolase activity levels of blood before (TKA) and after (TPPE) addition of thiamine pyrophosphate to the incubation mixture of the assay procedure. Two additional experiments assessed active transport of thiamine and the effect of dietary succinylsulfathiazole (SST) on TKA and TPPE in rats with moderate FD. Intestinal absorption in general and thiamine absorption in particular and thiamine status were unaltered in rats with severe FD. Inanition associated with severe FD may impair thiamine status. Thiamine absorption by active transport was not compromised in FD, and dietary succinylsulfathiazole did not affect thiamine status

  8. Quantitative flux analysis reveals folate-dependent NADPH production

    Science.gov (United States)

    Fan, Jing; Ye, Jiangbin; Kamphorst, Jurre J.; Shlomi, Tomer; Thompson, Craig B.; Rabinowitz, Joshua D.

    2014-06-01

    ATP is the dominant energy source in animals for mechanical and electrical work (for example, muscle contraction or neuronal firing). For chemical work, there is an equally important role for NADPH, which powers redox defence and reductive biosynthesis. The most direct route to produce NADPH from glucose is the oxidative pentose phosphate pathway, with malic enzyme sometimes also important. Although the relative contribution of glycolysis and oxidative phosphorylation to ATP production has been extensively analysed, similar analysis of NADPH metabolism has been lacking. Here we demonstrate the ability to directly track, by liquid chromatography-mass spectrometry, the passage of deuterium from labelled substrates into NADPH, and combine this approach with carbon labelling and mathematical modelling to measure NADPH fluxes. In proliferating cells, the largest contributor to cytosolic NADPH is the oxidative pentose phosphate pathway. Surprisingly, a nearly comparable contribution comes from serine-driven one-carbon metabolism, in which oxidation of methylene tetrahydrofolate to 10-formyl-tetrahydrofolate is coupled to reduction of NADP+ to NADPH. Moreover, tracing of mitochondrial one-carbon metabolism revealed complete oxidation of 10-formyl-tetrahydrofolate to make NADPH. As folate metabolism has not previously been considered an NADPH producer, confirmation of its functional significance was undertaken through knockdown of methylenetetrahydrofolate dehydrogenase (MTHFD) genes. Depletion of either the cytosolic or mitochondrial MTHFD isozyme resulted in decreased cellular NADPH/NADP+ and reduced/oxidized glutathione ratios (GSH/GSSG) and increased cell sensitivity to oxidative stress. Thus, although the importance of folate metabolism for proliferating cells has been long recognized and attributed to its function of producing one-carbon units for nucleic acid synthesis, another crucial function of this pathway is generating reducing power.

  9. Developing novel anthelmintics from plant cysteine proteinases

    Directory of Open Access Journals (Sweden)

    Stepek Gillian

    2008-09-01

    Full Text Available Abstract Intestinal helminth infections of livestock and humans are predominantly controlled by treatment with three classes of synthetic drugs, but some livestock nematodes have now developed resistance to all three classes and there are signs that human hookworms are becoming less responsive to the two classes (benzimidazoles and the nicotinic acetylcholine agonists that are licensed for treatment of humans. New anthelmintics are urgently needed, and whilst development of new synthetic drugs is ongoing, it is slow and there are no signs yet that novel compounds operating through different modes of action, will be available on the market in the current decade. The development of naturally-occurring compounds as medicines for human use and for treatment of animals is fraught with problems. In this paper we review the current status of cysteine proteinases from fruits and protective plant latices as novel anthelmintics, we consider some of the problems inherent in taking laboratory findings and those derived from folk-medicine to the market and we suggest that there is a wealth of new compounds still to be discovered that could be harvested to benefit humans and livestock.

  10. Cloning and characterization of a novel cysteine protease gene ...

    Indian Academy of Sciences (India)

    PRAKASH KUMAR

    Cysteine proteases can be found in the animal and plant kingdoms as well as in some viruses and bacteria. They have been implemented in many ..... in developing resistance against pathogens and insects in other crops. Acknowledgments.

  11. Biofortification of folates in white wheat bread by selection of yeast strain and process.

    Science.gov (United States)

    Hjortmo, Sofia; Patring, Johan; Jastrebova, Jelena; Andlid, Thomas

    2008-09-30

    We here demonstrate that folate content in yeast fermented food can be dramatically increased by using a proper (i) yeast strain and (ii) cultivation procedure for the selected strain prior to food fermentation. Folate levels were 3 to 5-fold higher in white wheat bread leavened with a Saccharomyces cerevisiae strain CBS7764, cultured in defined medium and harvested in the respiro-fermentative phase of growth prior to dough preparation (135-139 microg/100 dry matter), compared to white wheat bread leavened with commercial Baker's yeast (27-43 microg/100 g). The commercial Baker's yeast strain had been industrially produced, using a fed-batch process, thereafter compressed and stored in the refrigerator until bakings were initiated. This strategy is an attractive alternative to fortification of bread with synthetically produced folic acid. By using a high folate producing strain cultured a suitable way folate levels obtained were in accordance with folic acid content in fortified cereal products.

  12. Dietary folate, methionine, riboflavin, and vitamin B-6 and risk of sporadic colorectal cancer

    NARCIS (Netherlands)

    Vogel, S. de; Dindore, V.; Engeland, M. van; Goldbohm, R.A.; Brandt, P.A. van den; Weijenberg, M.P.

    2008-01-01

    Adequate intake of folate, methionine, riboflavin, and vitamin B-6 may prevent aberrant DNA methylation and thereby protect against colorectal cancer (CRC). However, previous epidemiological studies investigating associations between dietary intakes of these nutrients and CRC have been inconsistent.

  13. Smart dual-functional warhead for folate receptor-specific activatable imaging and photodynamic therapy.

    Science.gov (United States)

    Kim, Jisu; Tung, Ching-Hsuan; Choi, Yongdoo

    2014-09-21

    A smart dual-targeted theranostic agent becomes highly fluorescent and phototoxic only when its linker is cleaved by tumor-associated lysosomal enzyme cathepsin B after internalization into folate receptor-positive cancer cells.

  14. Folate and neural tube defects - Recommendations from a Danish working group

    DEFF Research Database (Denmark)

    Rasmussen, Lone Banke; Andersen, Niels Lyhne; Andersson, G.

    1998-01-01

    acid daily from a multivitamin/folic acid tablet. Women who have had a child with NTD and women who themselves have NTDs are recommended a supplement of 5 mg folic acid daily. Dietary changes and supplements should be initiated when pregnancy is planned........ Folate is a B-vitamin found in most food groups. In case-control studies and randomised studies, a protective effect of folic acid supplements on NTDs has been found. The studies show that a periconceptional folic acid supplement df 360 mu g to 4 mg daily decreases the recurrence rate of NTDs. Likewise......, in the few studies which calculate folate intake from the diet, a lower risk of NTD with higher intake of folate from the diet has been found. The folate intake can be increased by the diet, by folic acid supplements or by fortification of food a with folic acid. It is concluded that the incidence of NTDs...

  15. A novel folate-modified self-microemulsifying drug delivery system of curcumin for colon targeting

    Directory of Open Access Journals (Sweden)

    Zhang L

    2012-01-01

    Full Text Available Lin Zhang1*, Weiwei Zhu2*, Chunfen Yang1, Hongxia Guo1, Aihua Yu1, Jianbo Ji3, Yan Gao1, Min Sun1, Guangxi Zhai11Department of Pharmaceutical Engineering, College of Pharmacy, Shandong University, Jinan; 2Department of Pharmacy, Yantai Yuhuangding Hospital, Yantai; 3Department of Pharmacology, College of Pharmacy, Shandong University, Jinan, China*These authors contributed equally to the workBackground: The objective of this study was to prepare, characterize, and evaluate a folate-modified self-microemulsifying drug delivery system (FSMEDDS with the aim to improve the solubility of curcumin and its delivery to the colon, facilitating endocytosis of FSMEDDS mediated by folate receptors on colon cancer cells.Methods: Ternary phase diagrams were constructed in order to obtain the most efficient self-emulsification region, and the formulation of curcumin-loaded SMEDDS was optimized by a simplex lattice experiment design. Then, three lipophilic folate derivatives (folate-polyethylene glycol-distearoylphosphatidylethanolamine, folate-polyethylene glycol-cholesteryl hemisuccinate, and folate-polyethylene glycol-cholesterol used as a surfactant were added to curcumin-loaded SMEDDS formulations. An in situ colon perfusion method in rats was used to optimize the formulation of FSMEDDS. Curcumin-loaded FSMEDDS was then filled into colon-targeted capsules and the in vitro release was investigated. Cytotoxicity studies and cellular uptake studies was used in this research.Results: The optimal formulation of FSMEDDS obtained with the established in situ colon perfusion method in rats was comprised of 57.5% Cremophor® EL, 32.5% Transcutol® HP, 10% Capryol™ 90, and a small amount of folate-polyethylene glycol-cholesteryl hemisuccinate (the weight ratio of folate materials to Cremophor EL was 1:100. The in vitro release results indicated that the obtained formulation of curcumin could reach the colon efficiently and release the drug immediately. Cellular

  16. Reversible targeting of noncatalytic cysteines with chemically tuned electrophiles

    DEFF Research Database (Denmark)

    Serafimova, Iana M; Pufall, Miles A; Krishnan, Shyam

    2012-01-01

    Targeting noncatalytic cysteine residues with irreversible acrylamide-based inhibitors is a powerful approach for enhancing pharmacological potency and selectivity. Nevertheless, concerns about off-target modification motivate the development of reversible cysteine-targeting strategies. Here we...... of these electrophiles into a noncovalent kinase-recognition scaffold produced slowly dissociating, covalent inhibitors of the p90 ribosomal protein S6 kinase RSK2. A cocrystal structure revealed specific noncovalent interactions that stabilize the complex by positioning the electrophilic carbon near the targeted...

  17. Consumer preferences for micronutrient strategies in China. A comparison between folic acid supplementation and folate biofortification.

    Science.gov (United States)

    De Steur, Hans; Feng, Shuyi; Xiaoping, Shi; Gellynck, Xavier

    2014-06-01

    Despite public health efforts, folate deficiency is still largely prevalent in poor, rural populations and continues to cause a large burden of disease. The present paper determines and compares consumer preferences for two folate strategies: folic acid supplementation v. folate biofortification, i.e. the enhancement of the folate content in staple crops. Experimental auctions with non-repeated information rounds are applied to rice in order to obtain willingness-to-pay for folate products. Thereby, GM or non-GM folate-biofortified rice (FBR) is auctioned together with rice that is supplemented with free folic acid pills (FAR). Shanxi Province (China) as a high-risk region of folate deficiency. One hundred and twenty-six women of childbearing age, divided into a school (n 60) and market sample (n 66). Despite differences according to the targeted sample, a general preference for folate biofortification is observed, regardless of the applied breeding technology. Premiums vary between 33·9 % (GM FBR), 36·5 % (non-GM FBR) and 19·0 % (FAR). Zero bidding behaviour as well as the product choice question, respectively, support and validate these findings. The targeted sample, the timing of the auction, the intention to consume GM food and the responsibility for rice purchases are considered key determinants of product choice. A novel ex-post negative valuation procedure shows low consistency in zero bidding. While the low attractiveness of FAR provides an additional argument for the limited effectiveness of past folic acid supplementation programmes, the positive reactions towards GM FBR further support its potential as a possible complementary micronutrient intervention.

  18. Genetic variation throughout the folate metabolic pathway influences negative symptom severity in schizophrenia.

    Science.gov (United States)

    Roffman, Joshua L; Brohawn, David G; Nitenson, Adam Z; Macklin, Eric A; Smoller, Jordan W; Goff, Donald C

    2013-03-01

    Low serum folate levels previously have been associated with negative symptom risk in schizophrenia, as has the hypofunctional 677C>T variant of the MTHFR gene. This study examined whether other missense polymorphisms in folate-regulating enzymes, in concert with MTHFR, influence negative symptoms in schizophrenia, and whether total risk allele load interacts with serum folate status to further stratify negative symptom risk. Medicated outpatients with schizophrenia (n = 219), all of European origin and some included in a previous report, were rated with the Positive and Negative Syndrome Scale. A subset of 82 patients also underwent nonfasting serum folate testing. Patients were genotyped for the MTHFR 677C>T (rs1801133), MTHFR 1298A>C (rs1801131), MTR 2756A>G (rs1805087), MTRR 203A>G (rs1801394), FOLH1 484T>C (rs202676), RFC 80A>G (rs1051266), and COMT 675G>A (rs4680) polymorphisms. All genotypes were entered into a linear regression model to determine significant predictors of negative symptoms, and risk scores were calculated based on total risk allele dose. Four variants, MTHFR 677T, MTR 2756A, FOLH1 484C, and COMT 675A, emerged as significant independent predictors of negative symptom severity, accounting for significantly greater variance in negative symptoms than MTHFR 677C>T alone. Total allele dose across the 4 variants predicted negative symptom severity only among patients with low folate levels. These findings indicate that multiple genetic variants within the folate metabolic pathway contribute to negative symptoms of schizophrenia. A relationship between folate level and negative symptom severity among patients with greater genetic vulnerability is biologically plausible and suggests the utility of folate supplementation in these patients.

  19. Changing micronutrient intake through (voluntary) behaviour change. The case of folate.

    OpenAIRE

    Jensen, BB; Lähteenmäki, L; Grunert, KG; Brown, KA; Timotijevic, L; Barnett, J; Shepherd, R; Raats, MM

    2012-01-01

    The objective of this study was to relate behaviour change mechanisms to nutritionally relevant behaviour and demonstrate how the different mechanisms can affect attempts to change these behaviours. Folate was used as an example to illuminate the possibilities and challenges in inducing behaviour change. The behaviours affecting folate intake were recognised and categorised. Behaviour change mechanisms from "rational model of man", behavioural economics, health psychology and social...

  20. Cysteine homeostasis plays an essential role in plant immunity.

    Science.gov (United States)

    Álvarez, Consolación; Bermúdez, M Ángeles; Romero, Luis C; Gotor, Cecilia; García, Irene

    2012-01-01

    Cysteine is the metabolic precursor of essential biomolecules such as vitamins, cofactors, antioxidants and many defense compounds. The last step of cysteine metabolism is catalysed by O-acetylserine(thiol)lyase (OASTL), which incorporates reduced sulfur into O-acetylserine to produce cysteine. In Arabidopsis thaliana, the main OASTL isoform OAS-A1 and the cytosolic desulfhydrase DES1, which degrades cysteine, contribute to the cytosolic cysteine homeostasis. • Meta-analysis of the transcriptomes of knockout plants for OAS-A1 and for DES1 show a high correlation with the biotic stress series in both cases. • The study of the response of knockout mutants to plant pathogens shows that des1 mutants behave as constitutive systemic acquired resistance mutants, with high resistance to biotrophic and necrotrophic pathogens, salicylic acid accumulation and WRKY54 and PR1 induction, while oas-a1 knockout mutants are more sensitive to biotrophic and necrotrophic pathogens. However, oas-a1 knockout mutants lack the hypersensitive response associated with the effector-triggered immunity elicited by Pseudomonas syringae pv. tomato DC3000 avrRpm1. • Our results highlight the role of cysteine as a crucial metabolite in the plant immune response. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  1. Synthesis, antioxidative and whitening effects of novel cysteine derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Ji Hoon; Kim, Kyoung Mi; Jeong, Yoon Ju; Park, Young Min; Lee, Jae Young; Park, Soo Nam [Dept. of Fine Chemistry, Cosmetic R and D Center, Cosmetic Industry Coupled Collaboration Center, Seoul National University of Science and Technology, Seoul (Korea, Republic of); Park, Jino [Daebong LS. Ltd, Incheon (Korea, Republic of)

    2017-01-15

    Recently, development of biocompatibility functional cosmetic agents as antioxidant or whitening agent has increased. In this study, synthetic cysteine derivatives (DBLS-21, -24, and -33) were developed containing syringic acid and cysteine moieties (l-cysteine ethyl ester, N-acetyl cysteine methyl ester, and N-acetyl cysteine ethyl ester), and their antioxidative and whitening activities were evaluated. The cellular protective effect (τ{sub 50}) of DBLS-21 was 51.1 min at 50 μM on {sup 1}O{sub 2} -induced hemolysis of erythrocytes. This activity was slightly higher than that of α-tocopherol (43.6 min) as a lipophilic antioxidant. In the melanogenesis inhibitory effect, DBLS-21, -24, and -33 was 1.6-, 1.8-, and 2.5-fold higher than arbutin, respectively. In particular, DBLS-21 and -33 was 112.8- and 6.1-fold higher than arbutin, respectively (293.4 μM) on tyrosinase inhibition activity (IC{sub 50} ). But DBLS-24 had no tyrosinase inhibitory activity. These results suggest that cysteine derivatives possess potential for use as an antioxidant agent (DBLS-21) and whitening agents (all derivatives) in cosmetics.

  2. Synthesis, antioxidative and whitening effects of novel cysteine derivatives

    International Nuclear Information System (INIS)

    Ha, Ji Hoon; Kim, Kyoung Mi; Jeong, Yoon Ju; Park, Young Min; Lee, Jae Young; Park, Soo Nam; Park, Jino

    2017-01-01

    Recently, development of biocompatibility functional cosmetic agents as antioxidant or whitening agent has increased. In this study, synthetic cysteine derivatives (DBLS-21, -24, and -33) were developed containing syringic acid and cysteine moieties (l-cysteine ethyl ester, N-acetyl cysteine methyl ester, and N-acetyl cysteine ethyl ester), and their antioxidative and whitening activities were evaluated. The cellular protective effect (τ_5_0) of DBLS-21 was 51.1 min at 50 μM on "1O_2 -induced hemolysis of erythrocytes. This activity was slightly higher than that of α-tocopherol (43.6 min) as a lipophilic antioxidant. In the melanogenesis inhibitory effect, DBLS-21, -24, and -33 was 1.6-, 1.8-, and 2.5-fold higher than arbutin, respectively. In particular, DBLS-21 and -33 was 112.8- and 6.1-fold higher than arbutin, respectively (293.4 μM) on tyrosinase inhibition activity (IC_5_0 ). But DBLS-24 had no tyrosinase inhibitory activity. These results suggest that cysteine derivatives possess potential for use as an antioxidant agent (DBLS-21) and whitening agents (all derivatives) in cosmetics

  3. Gene-diet-interactions in folate-mediated one-carbon metabolism modify colon cancer risk.

    Science.gov (United States)

    Liu, Amy Y; Scherer, Dominique; Poole, Elizabeth; Potter, John D; Curtin, Karen; Makar, Karen; Slattery, Martha L; Caan, Bette J; Ulrich, Cornelia M

    2013-04-01

    The importance of folate-mediated one-carbon metabolism (FOCM) in colorectal carcinogenesis is emphasized by observations that high dietary folate intake is associated with decreased risk of colon cancer (CC) and its precursors. Additionally, polymorphisms in FOCM-related genes have been repeatedly associated with risk, supporting a causal relationship between folate and colorectal carcinogenesis. We investigated ten candidate polymorphisms with defined or probable functional impact in eight FOCM-related genes (SHMT1, DHFR, DNMT1, MTHFD1, MTHFR, MTRR, TCN2, and TDG) in 1609 CC cases and 1974 controls for association with CC risk and for interaction with dietary factors. No polymorphism was statistically significantly associated with overall risk of CC. However, statistically significant interactions modifying CC risk were observed for DNMT1 I311V with dietary folate, methionine, vitamin B2 , and vitamin B12 intake and for MTRR I22M with dietary folate, a predefined one-carbon dietary pattern, and vitamin B6 intake. We observed statistically significant gene-diet interactions with five additional polymorphisms. Our results provide evidence that FOCM-related dietary intakes modify the association between CC risk and FOCM allelic variants. These findings add to observations showing that folate-related gene-nutrient interactions play an important role in modifying the risk of CC. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Folate status in women of reproductive age as basis of neural tube defect risk assessment.

    Science.gov (United States)

    Bailey, Lynn B; Hausman, Dorothy B

    2018-02-01

    Reliable folate status data for women of reproductive age (WRA) to assess global risk for neural tube defects (NTDs) are needed. We focus on a recent recommendation by the World Health Organization that a specific "optimal" red blood cell (RBC) folate concentration be used as the sole indicator of NTD risk within a population and discuss how to best apply this guidance to reach the goal of assessing NTD risk globally. We also emphasize the importance of using the microbiologic assay (MBA) as the most reliable assay for obtaining comparable results for RBC folate concentration across time and countries, the need for harmonization of the MBA through use of consistent key reagents and procedures within laboratories, and the requirement to apply assay-matched cutoffs for folate deficiency and insufficiency. To estimate NTD risk globally, the ideal scenario would be to have country-specific population-based surveys of RBC folate in WRA determined utilizing a harmonized MBA, as was done in recent studies in Guatemala and Belize. We conclude with guidance on next steps to best navigate the road map toward the goal of generating reliable folate status data on which to assess NTD risk in WRA in low- and middle-income countries. © 2017 The Authors. Annals of the New York Academy of Sciences published by Wiley Periodicals, Inc. on behalf of New York Academy of Sciences.

  5. Chitosan-folate decorated carbon nanotubes for site specific lung cancer delivery.

    Science.gov (United States)

    Singh, Rahul Pratap; Sharma, Gunjan; Sonali; Singh, Sanjay; Bharti, Shreekant; Pandey, Bajarangprasad L; Koch, Biplob; Muthu, Madaswamy S

    2017-08-01

    The aim of this work was to formulate chitosan-folate conjugated multi-walled carbon nanotubes for the lung cancer targeted delivery of docetaxel. The chitosan-folate conjugate was synthesized and the conjugation was confirmed by Fourier transform infrared spectroscopy. The multi-walled carbon nanotubes were characterized for their particle size, polydispersity, zeta potential, surface morphology, drug encapsulation efficiency and in vitro release study. The in vitro cellular uptake, cytotoxicity, and cell cycle analysis of the docetaxel/coumarin-6 loaded multi-walled carbon nanotubes were carried out to compare the effectiveness of the formulations. The biocompatibility and safety of chitosan-folate conjugated multi-walled carbon nanotubes was analyzed by lung histopathology in comparison with marketed docetaxel formulation (Docel™) and acylated multi-walled carbon nanotubes. The cellular internalization study shown that the chitosan-folate conjugated multi-walled carbon nanotubes could be easily internalized into the lung cancer cells through a folate receptor-mediated endocytic pathway. The IC 50 values exhibited that chitosan-folate conjugated multi-walled carbon nanotubes could be 89-fold more effective than Docel™ in human lung cancer cells (A549 cells). Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Comparison of radioassay and microbiological assay for serum folate, with clinical assessment of discrepant results

    International Nuclear Information System (INIS)

    Baril, L.; Carmel, R.

    1978-01-01

    Folate assays by use of radiolabeled folate provide obvious practical advantages over the standard microbiological assay, but remain incompletely tested. We therefore compared results for 415 sera with a kit involving 3 H-labeled folate and the Lactobacillus casei microbiological method. We examined the patients' data when there were discrepancies between the two methods. Although the correlation overall was satisfactory, results were discrepant in 25% of cases. In 74% of the latter, the radioassay result appeared to be the correct one, primarily because L. casei results were suppressed by antibiotics being taken by the patient. The radioassay occasionally gave falsely high values for patients with liver disease and falsely low ones for patients who had received isotopes for scanning purposes. Several assay kits that make use of 125 I- or 75 Se-labeled folate were also tested. Although these results correlated with the results of 3 H-labeled folate assay, various problems appeared, including the possible need for serum-supernate control tubes in one kit. Answers to these and other questions and careful clinical correlation of results are needed for any folate radioassays before their adoption for routine clinical use

  7. Conjugating folate on superparamagnetic Fe3O4@Au nanoparticles using click chemistry

    International Nuclear Information System (INIS)

    Shen, Xiaofang; Ge, Zhaoqiang; Pang, Yuehong

    2015-01-01

    Gold-coated magnetic core@shell nanoparticles, which exhibit magneto-optical properties, not only enhance the chemical stability of core and biocompatibility of surface, but also provide a combination of multimodal imaging and therapeutics. The conjugation of these tiny nanoparticles with specific biomolecules allows researchers to target the desired location. In this paper, superparamagnetic Fe 3 O 4 @Au nanoparticles were synthesized and functionalized with the azide group on the surface by formation of self-assembled monolayers. Folate (FA) molecules, non-immunogenic target ligands for cancer cells, are conjugated with alkyne and then immobilized on the azide-terminated Fe 3 O 4 @Au nanoparticles through copper(I)-catalyzed azide-alkyne cycloaddition (click reaction). Myelogenous leukemia K562 cells were used as a folate receptor (FR) model, which can be targeted and extracted by magnetic field after interaction with the Fe 3 O 4 @Au–FA nanoparticles. - Graphical abstract: Self-assembled azide-terminated group on superparamagnetic Fe 3 O 4 @Au nanoparticles followed by click reaction with alkyne-functionalized folate, allowing the nanoparticles target folate receptor of cancer cells. - Highlights: • Azidoundecanethiol was coated on the superparamagnetic Fe 3 O 4 @Au nanoparticles by forming self-assembled monolayers. • Alkyne-terminated folate was synthesized from a reaction between the amine and the carboxylic acid. • Conjugation of Fe 3 O 4 @Au nanoparticles with folate was made by copper-catalyzed azide-alkyne cycloaddition click chemistry

  8. Improvement of Folate Biosynthesis by Lactic Acid Bacteria Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Norfarina Muhamad Nor

    2010-01-01

    Full Text Available Lactic acid bacteria (Lactococcus lactis NZ9000, Lactococcus lactis MG1363, Lactobacillus plantarum I-UL4 and Lactobacillus johnsonii DSM 20553 have been screened for their ability to produce folate intracellularly and/or extracellularly. L. plantarum I-UL4 was shown to be superior producer of folate compared to other strains. Statistically based experimental designs were used to optimize the medium formulation for the growth of L. plantarum I-UL4 and folate biosynthesis. The optimal values of important factors were determined by response surface methodology (RSM. The effects of carbon sources, nitrogen sources and para-aminobenzoic acid (PABA concentrations on folate biosynthesis were determined prior to RSM study. The biosynthesis of folate by L. plantarum I-UL4 increased from 36.36 to 60.39 µg/L using the optimized medium formulation compared to the selective Man de Rogosa Sharpe (MRS medium. Conditions for the optimal growth of L. plantarum I-UL4 and folate biosynthesis as suggested by RSM were as follows: lactose 20 g/L, meat extract 16.57 g/L and PABA 10 µM.

  9. Impact of Maternal Folate Deficiencies on Early Neurological Development: A Narrative Review

    Directory of Open Access Journals (Sweden)

    Joshua T Emmerson

    2016-07-01

    Full Text Available Context Folates are B-vitamins that cannot be generated de novo and are therefore obtained from the diet. In the brain, these vitamins are involved in nucleotide synthesis, DNA repair, lipid metabolism, methylation and neurotransmitter synthesis. It is well established that adequate levels of maternal folates are required for closure of the neural tube within the first month of pregnancy, however, it is not clear whether maternal folates are needed throughout pregnancy for brain development and whether they influence offspring neurological function after birth. The aim of this review is to outline current literature from epidemiological and animal model studies that shows maternal supplementation of folates throughout pregnancy does indeed affect offspring neurological function after birth. Evidence Acquisition A Medline search was performed using the following mesh terms, maternal-fetal exchange, folic acid, offspring neurologic manifestations, methylenetetrahydrofolate reductase (MTHFR, embryology, and behavior. Results The studies described in the present review have reported that maternal deficiencies in folates during pregnancy result in changes in behavior as well as in blood and brain tissue in offspring, including altered methylation, including reduced levels of the global methyl donor S-adenosylmethionine (SAM, and increased levels of oxidative stress. Conclusions The data summarized here outlines the importance of adequate levels of folates throughout pregnancy to facilitate appropriate neurological development of offspring after birth.

  10. Low molecular weight chitosan conjugated with folate for siRNA delivery in vitro: optimization studies

    Science.gov (United States)

    Fernandes, Julio C; Qiu, Xingping; Winnik, Francoise M; Benderdour, Mohamed; Zhang, Xiaoling; Dai, Kerong; Shi, Qin

    2012-01-01

    The low transfection efficiency of chitosan is one of its drawbacks as a gene delivery carrier. Low molecular weight chitosan may help to form small-sized polymer-DNA or small interfering RNA (siRNA) complexes. Folate conjugation may improve gene transfection efficiency because of the promoted uptake of folate receptor-bearing cells. In the present study, chitosan was conjugated with folate and investigated for its efficacy as a delivery vector for siRNA in vitro. We demonstrate that the molecular weight of chitosan has a major influence on its biological and physicochemical properties, and very low molecular weight chitosan (below 10 kDa) has difficulty in forming stable complexes with siRNA. In this study, chitosan 25 kDa and 50 kDa completely absorbed siRNA and formed nanoparticles (≤220 nm) at a chitosan to siRNA weight ratio of 50:1. The introduction of a folate ligand onto chitosan decreased nanoparticle toxicity. Compared with chitosan-siRNA, folate-chitosan-siRNA nanoparticles improved gene silencing transfection efficiency. Therefore, folate-chitosan shows potential as a viable candidate vector for safe and efficient siRNA delivery. PMID:23209368

  11. [Relationship and interaction between folate and expression of methyl-CpG-binding protein 2 in cervical cancerization].

    Science.gov (United States)

    Li, Q L; Ding, L; Nan, J; Liu, C L; Yang, Z K; Chen, F; Liang, Y L; Wang, J T

    2016-07-01

    To explore the interaction between folate and the expression of methyl-CpG-binding protein 2(MeCP2)in cervical cancerization. Forty one patients diagnosed with cervical squamous cell carcinoma(SCC), 71 patients diagnosed with cervical intraepithelial neoplasm(CIN1, n=34; CIN2 +, n=37)and 61 women with normal cervix(NC)were recruited in this study. Microbiological assay was conducted to detect the levels of serum folate and RBC folate, Western blot assay and real-time PCR were performed to detect the expression levels of MeCP2 protein and mRNA, respectively. The data were analyzed by Kruskal-Wallis H test, χ(2) test, trend χ(2) test and Spearman correlation with SPSS statistical software(version 20.0), and the interaction were evaluated by using generalized multifactor dimensionality reduction(GMDR)model. The levels of serum folate(H=44.71, Pfolate(H=5.28, Pfolate level and RBC folate level(r=0.270, Pfolate level and the expression level of MeCP2 protein(serum folate: r=-0.226, P=0.003; RBC folate: r=-0.164, P=0.004). Moreover, the results by GMDR model revealed there were interaction among serum folate deficiency, RBC folate deficiency, MeCP2 protein high expression and MeCP2 mRNA high expression in SCC and CIN2 + patients. Folate deficiency and high expression of MeCP2 gene might increase the risk of cervical cancer and its precancerous lesions through interaction among serum folate deficiency, RBC folate deficiency, MeCP2 protein high expression and mRNA high expression in the progression of cervical cancerization.

  12. Measuring site occupancy: a new perspective on cysteine oxidation.

    Science.gov (United States)

    Rogowska-Wrzesinska, Adelina; Wojdyla, Katarzyna; Williamson, James; Roepstorff, Peter

    2014-10-01

    Site occupancy is an extremely important aspect of quantification of protein modifications. Knowing the degree of modification of each oxidised cysteine residue is critical to understanding the biological role of these modifications. Yet modification site occupancy is very often overlooked, in part because there are very few analytical tools that allow such measurements. Here we present a new strategy, which provides quantitative analysis of cysteine S-nitrosylation (SNO) and S-sulfenylation (SOH) simultaneously at the resolution of single cysteine and allows for determination of relative oxidation occupancy of the modification site. We show that, on one hand, heavily modified cysteines are not necessarily involved in the response to oxidative stress. On the other hand residues with low modification level can be dramatically affected by mild oxidative imbalance. We make use of high resolution mass spectrometry. The method relies on differential reduction of "total" cysteines, SNO cysteines and SOH cysteines with TCEP, sodium ascorbate and sodium arsenite respectively followed by iodoTMT(TM) alkylation. Enrichment of iodoTMT(TM)-containing peptides is performed using anti-TMT antibody. In vivo model of mild oxidative stress in Escherichia coli is used. To induce endogenous SNO bacteria were grown anaerobically in minimal media supplemented with fumarate or nitrate. Short-term treatment with submilimolar levels of hydrogen peroxide were used to induce SOH. We have quantified 114 SNO/SOH modified peptides corresponding to 90 proteins. Only 6 modified peptides changed significantly under mild oxidative stress. Quantitative information allowed us to determine relative modification site occupancy of each identified modified residue and pin point heavily modified ones. The method proved to be precise and sensitive enough to detect and quantify endogenous levels of oxidative stress on proteome-wide scale and brings a new perspective on the role of the modification site

  13. Synergistic effect of nano-sized mackinawite with cyano-cobalamin in cement slurries for reductive dechlorination of tetrachloroethylene

    Energy Technology Data Exchange (ETDEWEB)

    Kyung, Daeseung [Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of); Sihn, Youngho [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of); Kim, Sangwoo [Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of); Bae, Sungjun [Department of Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029 (Korea, Republic of); Amin, Muhammad Tahir; Alazba, Abdulrahman Ali [Alamoudi Water Chair, King Saud University, Riyadh 11451 (Saudi Arabia); Lee, Woojin, E-mail: woojin_lee@kaist.ac.kr [Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of)

    2016-07-05

    Highlights: • Complete degradation of PCE was observed in nFeS-Cbl(III)-cement at pH 12. • PCE was completely degraded to non-chlorinated organic compounds by this system. • Co redox couple and Ca species in cement played a pivotal role for PCE reduction. • Increases in Cbl(III) concentration, cement ratio, and pH enhanced PCE degradation. • Efficiency of the system for PCE reduction was good even at high concentration of PCE. - Abstract: Experiments were conducted to investigate the reductive dechlorination of tetrachloroethylene (PCE) by nano-Mackinawite (nFeS) with cyano-cobalamin (Cbl(III)) in cement slurries. Almost complete degradation of PCE by nFeS-Cbl(III) was observed in cement slurries in 5 h and its degradation kinetics (k{sub obs-PCE} = 0.57 h{sup −1}) was 6-times faster than that of nFeS-Cbl(III) without the cement slurries. PCE was finally transformed to non-chlorinated organic compounds such as ethylene, acetylene, and C3-C4 hydrocarbons by nFeS-Cbl(III) in cement slurries. X-ray photoelectron spectroscopy and PCE degradation by cement components (SiO{sub 2}, Al{sub 2}O{sub 3}, and CaO) revealed that both the reduced Co species in Cbl(III) and the presence of Ca in cement played an important role for the enhanced reductive dechlorination of PCE. The increase in the concentration of Cbl(III) (0.005–0.1 mM), cement ratio (0.05–0.2), and suspension pH (11.5–13.5) accelerated the PCE degradation kinetics by providing more favorable environments for the production of reactive Ca species and reduction of Co species. We also observed that the degradation efficiency of PCE by nFeS-Cbl(III)-cement lasted even at high concentration of PCE. The experimental results obtained from this study could provide fundamental knowledge of redox interactions among nFeS, Cbl(III), and cement, which could significantly enhance reductive dechlorination of chlorinated organics in contaminated natural and engineered environments.

  14. Synergistic effect of nano-sized mackinawite with cyano-cobalamin in cement slurries for reductive dechlorination of tetrachloroethylene

    International Nuclear Information System (INIS)

    Kyung, Daeseung; Sihn, Youngho; Kim, Sangwoo; Bae, Sungjun; Amin, Muhammad Tahir; Alazba, Abdulrahman Ali; Lee, Woojin

    2016-01-01

    Highlights: • Complete degradation of PCE was observed in nFeS-Cbl(III)-cement at pH 12. • PCE was completely degraded to non-chlorinated organic compounds by this system. • Co redox couple and Ca species in cement played a pivotal role for PCE reduction. • Increases in Cbl(III) concentration, cement ratio, and pH enhanced PCE degradation. • Efficiency of the system for PCE reduction was good even at high concentration of PCE. - Abstract: Experiments were conducted to investigate the reductive dechlorination of tetrachloroethylene (PCE) by nano-Mackinawite (nFeS) with cyano-cobalamin (Cbl(III)) in cement slurries. Almost complete degradation of PCE by nFeS-Cbl(III) was observed in cement slurries in 5 h and its degradation kinetics (k_o_b_s_-_P_C_E = 0.57 h"−"1) was 6-times faster than that of nFeS-Cbl(III) without the cement slurries. PCE was finally transformed to non-chlorinated organic compounds such as ethylene, acetylene, and C3-C4 hydrocarbons by nFeS-Cbl(III) in cement slurries. X-ray photoelectron spectroscopy and PCE degradation by cement components (SiO_2, Al_2O_3, and CaO) revealed that both the reduced Co species in Cbl(III) and the presence of Ca in cement played an important role for the enhanced reductive dechlorination of PCE. The increase in the concentration of Cbl(III) (0.005–0.1 mM), cement ratio (0.05–0.2), and suspension pH (11.5–13.5) accelerated the PCE degradation kinetics by providing more favorable environments for the production of reactive Ca species and reduction of Co species. We also observed that the degradation efficiency of PCE by nFeS-Cbl(III)-cement lasted even at high concentration of PCE. The experimental results obtained from this study could provide fundamental knowledge of redox interactions among nFeS, Cbl(III), and cement, which could significantly enhance reductive dechlorination of chlorinated organics in contaminated natural and engineered environments.

  15. Folate coupled poly(ethyleneglycol) conjugates of anionic poly(amidoamine) dendrimer for inflammatory tissue specific drug delivery.

    Science.gov (United States)

    Chandrasekar, Durairaj; Sistla, Ramakrishna; Ahmad, Farhan J; Khar, Roop K; Diwan, Prakash V

    2007-07-01

    Folate receptor is overexpressed on the activated (but not quiescent) macrophages in both animal models and human patients with naturally occurring rheumatoid arthritis. The aim of this study was to prepare folate targeted poly(ethylene glycol) (PEG) conjugates of anionic dendrimer (G3.5 PAMAM) as targeted drug delivery systems to inflammation and to investigate its biodistribution pattern in arthritic rats. Folate-PEG-PAMAM conjugates, with different degrees of substitution were synthesized by a two-step reaction through a carbodiimide-mediated coupling reaction and loaded with indomethacin. Folate-PEG conjugation increased the drug loading efficiency by 10- to 20-fold and the in vitro release profile indicated controlled release of drug. The plasma pharmacokinetic parameters indicated an increased AUC, circulatory half-life and mean residence time for the folate-PEG conjugates. The tissue distribution studies revealed significantly lesser uptake by stomach for the folate-PEG conjugates, thereby limiting gastric-related side effect. The time-averaged relative drug exposure (r(e)) of the drug in paw for the folate-PEG conjugates ranged from 1.81 to 2.37. The overall drug targeting efficiency (T(e)) was highest for folate-PEG conjugate (3.44) when compared to native dendrimer (1.72). The folate-PEG-PAMAM conjugates are the ideal choice for targeted delivery of antiarthritic drugs to inflammation with reduced side-effects and higher targeting efficiency. Copyright 2007 Wiley Periodicals, Inc.

  16. Reduction in unnecessary red blood cell folate testing by restricting computerized physician order entry in the electronic health record.

    Science.gov (United States)

    MacMillan, Thomas E; Gudgeon, Patrick; Yip, Paul M; Cavalcanti, Rodrigo B

    2018-05-02

    Red blood cell folate is a laboratory test with limited clinical utility. Previous attempts to reduce physician ordering of unnecessary laboratory tests, including folate, have resulted in only modest success. The objective of this study was to assess the effectiveness and impacts of restricting red blood cell folate ordering in the electronic health record. This was a retrospective observational study from January 2010 to December 2016 at a large academic healthcare network in Toronto, Canada. All inpatients and outpatients who underwent at least 1 red blood cell folate or vitamin B12 test during the study period were included. Red blood cell folate ordering was restricted to clincians in gastroenterology and hematology and was removed from other physicians' computerized order entry screen in the electronic health record in June 2013. Red blood cell folate testing decreased by 94.4% during the study, from a mean of 493.0 (SD 48.0) tests/month before intervention to 27.6 (SD 10.3) tests/month after intervention (P<.001). Restricting red blood cell folate ordering in the electronic health record resulted in a large and sustained reduction in red blood cell folate testing. Significant cost savings estimated at over a quarter-million dollars (CAD) over three years were achieved. There was no significant clinical impact of the intervention on the diagnosis of folate deficiency. Copyright © 2018. Published by Elsevier Inc.

  17. Evidence that the low-affinity folate-binding protein in erythrocyte hemolysate is identical to hemoglobin

    International Nuclear Information System (INIS)

    Hansen, S.I.; Holm, J.; Lyngbye, J.

    1981-01-01

    Gel filtration studies on erythrocyte hemolysate demonstrated the presence of a folate binding protein, apparently of the low-affinity type, that co-elutes with hemoglobin. Further, the folate binder eluted with a low salt concentration after DEAE-Sepharose CL-6B anion-exchange chromatography of erythrocyte hemolysate at pH 6.3. The chromatographic behavior of hemoglobin labeled with [3H]folate was so similar to that of the present binder as to suggest that the folate binder in erythrocytes is in fact hemoglobin

  18. On the Dynamical Behavior of the Cysteine Dioxygenase-l-Cysteine Complex in the Presence of Free Dioxygen and l-Cysteine.

    Science.gov (United States)

    Pietra, Francesco

    2017-11-01

    In this work, viable models of cysteine dioxygenase (CDO) and its complex with l-cysteine dianion were built for the first time, under strict adherence to the crystal structure from X-ray diffraction studies, for all atom molecular dynamics (MD). Based on the CHARMM36 FF, the active site, featuring an octahedral dummy Fe(II) model, allowed us observing water exchange, which would have escaped attention with the more popular bonded models. Free dioxygen (O 2 ) and l-cysteine, added at the active site, could be observed being expelled toward the solvating medium under Random Accelerated Molecular Dynamics (RAMD) along major and minor pathways. Correspondingly, free dioxygen (O 2 ), added to the solvating medium, could be observed to follow the same above pathways in getting to the active site under unbiased MD. For the bulky l-cysteine, 600 ns of trajectory were insufficient for protein penetration, and the molecule was stuck at the protein borders. These models pave the way to free energy studies of ligand associations, devised to better clarify how this cardinal enzyme behaves in human metabolism. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  19. Excess folate during adolescence suppresses thyroid function with permanent deficits in motivation and spatial memory.

    Science.gov (United States)

    Sittig, L J; Herzing, L B K; Xie, H; Batra, K K; Shukla, P K; Redei, E E

    2012-03-01

    Cognitive and memory deficits can be caused or exacerbated by dietary folate deficiency, which has been combatted by the addition of folate to grains and dietary supplements. The recommended dose of the B9 vitamin folate is 400 µg/day for adolescents and non-pregnant adults, and consumption above the recommended daily allowance is not considered to be detrimental. However, the effects of excess folate have not been tested in adolescence when neuro and endocrine development suggest possible vulnerability to long-term cognitive effects. We administered folate-supplemented (8.0 mg folic acid/kg diet) or control lab chow (2.7 mg folic acid/kg diet) to rats ad libitum from 30 to 60 days of age, and subsequently tested their motivation and learning and memory in the Morris water maze. We found that folate-supplemented animals had deficits in motivation and spatial memory, but they showed no changes of the learning- and memory-related molecules growth-associated protein-43 or Gs-α subunit protein in the hippocampus. They had decreased levels of thyroxine (T4) and triiodothyronine (T3) in the periphery and decreased protein levels of thyroid receptor-α1 and -α2 (TRα1 and TRα2) in the hippocampus. The latter may have been due to an observed increase of cytosine-phosphate-guanosine island methylation within the putative thyroid hormone receptor-α promoter, which we have mapped for the first time in the rat. Overall, folate supplementation in adolescence led to motivational and spatial memory deficits that may have been mediated by suppressed thyroid hormone function in the periphery and hippocampus. © 2011 The Authors. Genes, Brain and Behavior © 2011 Blackwell Publishing Ltd and International Behavioural and Neural Genetics Society.

  20. The effect of folate status on the uptake of physiologically relevant compounds by Caco-2 cells.

    Science.gov (United States)

    Tavares, Sandra; Sousa, Joana; Gonçalves, Pedro; Araújo, João R; Martel, Fátima

    2010-08-25

    The aim of this work was to investigate the effect of folate status on the uptake of several physiologically relevant substances by Caco-2 cells. For this, Caco-2 cells cultured in high-folate conditions (HF) and low-folate conditions (LF) were compared. Growth rates of HF and LF Caco-2 cells were similar. However, proliferation rate of LF cells was greater than that of HF cells during the first 2days of culture and slightly smaller thereafter, viability of LF cells was greater than that of HF cells, and apoptosis index was similar in both cell cultures. We verified that in LF cells, comparatively to HF cells: (1) uptake of [3H]folic acid is upregulated, via an increase in the Vmax of uptake; (2) uptake of [3H]deoxy-glucose, [3H]O-methyl-glucose and [3H]1-methyl-4-phenylpyridinium (MPP+) is downregulated, via a decrease in the Vmax of uptake; additionally, a reduction in Km was observed for [3H]O-methyl-glucose; (3) uptake of [3H]5-hydroxytryptamine and [14C]butyrate is not changed; and (4) the steady-state mRNA levels of the folic acid transporters RFC (reduced folate carrier), PCFT (proton-coupled folate transporter) and FRalpha (folate receptor alpha), of the organic cation transporter OCT1 (organic cation transporter type 1), of the glucose transporter GLUT2 (facilitative glucose transporter type 2) and of the butyrate transporter MCT1 (monocarboxylate transporter type 1) were decreased. In conclusion, folate deficiency produces substrate-specific changes in the uptake of bioactive compounds by Caco-2 cells. Moreover, these changes are associated with alterations in the mRNA levels of specific transporters for these compounds. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  1. Biotin Switch Assays for Quantitation of Reversible Cysteine Oxidation.

    Science.gov (United States)

    Li, R; Kast, J

    2017-01-01

    Thiol groups in protein cysteine residues can be subjected to different oxidative modifications by reactive oxygen/nitrogen species. Reversible cysteine oxidation, including S-nitrosylation, S-sulfenylation, S-glutathionylation, and disulfide formation, modulate multiple biological functions, such as enzyme catalysis, antioxidant, and other signaling pathways. However, the biological relevance of reversible cysteine oxidation is typically underestimated, in part due to the low abundance and high reactivity of some of these modifications, and the lack of methods to enrich and quantify them. To facilitate future research efforts, this chapter describes detailed procedures to target the different modifications using mass spectrometry-based biotin switch assays. By switching the modification of interest to a biotin moiety, these assays leverage the high affinity between biotin and avidin to enrich the modification. The use of stable isotope labeling and a range of selective reducing agents facilitate the quantitation of individual as well as total reversible cysteine oxidation. The biotin switch assay has been widely applied to the quantitative analysis of S-nitrosylation in different disease models and is now also emerging as a valuable research tool for other oxidative cysteine modifications, highlighting its relevance as a versatile, robust strategy for carrying out in-depth studies in redox proteomics. © 2017 Elsevier Inc. All rights reserved.

  2. Folate-targeted nanoparticles for rheumatoid arthritis therapy.

    Science.gov (United States)

    Nogueira, Eugénia; Gomes, Andreia C; Preto, Ana; Cavaco-Paulo, Artur

    2016-05-01

    Rheumatoid arthritis (RA) is the most common inflammatory rheumatic disease, affecting almost 1% of the world population. Although the cause of RA remains unknown, the complex interaction between immune mediators (cytokines and effector cells) is responsible for the joint damage that begins at the synovial membrane. Activated macrophages are critical in the pathogenesis of RA and showed specifically express a receptor for the vitamin folic acid (FA), folate receptor β (FRβ). This particular receptor allows internalization of FA-coupled cargo. In this review we will address the potential of nanoparticles as an effective drug delivery system for therapies that will directly target activated macrophages. Special attention will be given to stealth degree of the nanoparticles as a strategy to avoid clearance by macrophages of the mononuclear phagocytic system (MPS). This review summarizes the application of FA-target nanoparticles as drug delivery systems for RA and proposes prospective future directions. Rheumatoid arthritis is a debilitating autoimmune disease of the joints which affects many people worldwide. Up till now, there is a lack of optimal therapy against this disease. In this review article, the authors outlined in depth the current mechanism of disease for rheumatoid arthritis and described the latest research in using folic acid-targeted nanoparticles to target synovial macrophages in the fight against rheumatoid arthritis. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Targeting Gallium to Cancer Cells through the Folate Receptor

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    Nerissa Viola-Villegas

    2008-01-01

    Full Text Available The development of gallium(III compounds as anti-cancer agents for both treatment and diagnosis is a rapidly developing field of research. Problems remain in exploring the full potential of gallium(III as a safe and successful therapeutic agent or as an imaging agent. One of the major issues is that gallium(III compounds have little tropism for cancer cells. We have combined the targeting properties of folic acid (FA with long chain liquid polymer poly(ethylene glycol (PEG 'spacers’. This FA-PEG unit has been coupled to the gallium coordination complex of 1,4,7,10-tetraazacyclo-dodecane-N, N′, N′, N′′-tetraacetic acid (DOTA through amide linkages for delivery into target cells overexpressing the folate receptor (FR. In vitro cytotoxicity assays were conducted against a multi-drug resistant ovarian cell line (A2780/AD that overexpresses the FR and contrasted against a FR free Chinese hamster ovary (CHO cell line. Results are rationalized taking into account stability studies conducted in RPMI 1640 media and HEPES buffer at pH 7.4.

  4. Targeting Gallium to Cancer Cells through the Folate Receptor

    Directory of Open Access Journals (Sweden)

    Nerissa Viola-Villegas

    2008-01-01

    Full Text Available The development of gallium(III compounds as anti-cancer agents for both treatment and diagnosis is a rapidly developing field of research. Problems remain in exploring the full potential of gallium(III as a safe and successful therapeutic agent or as an imaging agent. One of the major issues is that gallium(III compounds have little tropism for cancer cells. We have combined the targeting properties of folic acid (FA with long chain liquid polymer poly(ethylene glycol (PEG ‘spacers’. This FA-PEG unit has been coupled to the gallium coordination complex of 1,4,7,10-tetraazacyclo-dodecane-N,N′,N′′,N′′′-tetraacetic acid (DOTA through amide linkages for delivery into target cells overexpressing the folate receptor (FR. In vitro cytotoxicity assays were conducted against a multi-drug resistant ovarian cell line (A2780/AD that overexpresses the FR and contrasted against a FR free Chinese hamster ovary (CHO cell line. Results are rationalized taking into account stability studies conducted in RPMI 1640 media and HEPES buffer at pH 7.4.

  5. A NOS3 polymorphism determines endothelial response to folate in children with type 1 diabetes or obesity.

    Science.gov (United States)

    Wiltshire, Esko J; Peña, Alexia S; MacKenzie, Karen; Bose-Sundernathan, Tulika; Gent, Roger; Couper, Jennifer J

    2015-02-01

    To determine the effect of polymorphisms in NOS3 and folate pathway enzymes on vascular function and folate status and endothelial response to folate in children with diabetes or obesity. A total of 244 subjects (age 13.8 ± 2.8 years, 125 males) were studied for NOS3 and/or folate pathway polymorphisms using polymerase chain reaction/restriction fragment length polymorphism, including at baseline: 139 with type 1 diabetes; 58 with obesity; and 47 controls. The effect of NOS3 genotype on endothelial response to folate (5 mg) was assessed in 85 subjects with diabetes and 28 obese subjects who received active treatment during intervention trials. Vascular function (flow-mediated dilatation [FMD] and glyceryl trinitrate-mediated dilatation), clinical, and biochemical measurements were assessed at baseline and 8 weeks in folate intervention studies. Folate pathway enzyme and NOS3 polymorphisms did not significantly affect baseline vascular function. The polymorphism in intron 4 of endothelial nitric oxide synthase altered endothelial response to folate significantly: in subjects with diabetes FMD improved by 6.4 ± 5% (insertion carriers) vs 2.3 ± 6.6% (deletion carriers), P = .01; in obese subjects FMD improved by 1.8 ± 5.4% (insertion carriers) and deteriorated by -3.2 ± 7.2% (deletion carriers), P = .05. More subjects carrying the insertion normalized FMD after folate supplementation (insertion 64% vs deletion 28%, χ(2) = 10.14, P = .001). A NOS3 polymorphism predicts endothelial response to folate in children with diabetes or obesity, with implications for vascular risk and folate intervention studies. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. High serum folate is associated with reduced biochemical recurrence after radical prostatectomy: Results from the SEARCH Database

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    Daniel M. Moreira

    2013-06-01

    Full Text Available Introduction To analyze the association between serum levels of folate and risk of biochemical recurrence after radical prostatectomy among men from the Shared Equal Access Regional Cancer Hospital (SEARCH database. Materials and Methods Retrospective analysis of 135 subjects from the SEARCH database treated between 1991-2009 with available preoperative serum folate levels. Patients' characteristics at the time of the surgery were analyzed with ranksum and linear regression. Uni- and multivariable analyses of folate levels (log-transformed and time to biochemical recurrence were performed with Cox proportional hazards. Results The median preoperative folate level was 11.6ng/mL (reference = 1.5-20.0ng/mL. Folate levels were significantly lower among African-American men than Caucasians (P = 0.003. In univariable analysis, higher folate levels were associated with more recent year of surgery (P < 0.001 and lower preoperative PSA (P = 0.003. In univariable analysis, there was a trend towards lower risk of biochemical recurrence among men with high folate levels (HR = 0.61, 95%CI = 0.37-1.03, P = 0.064. After adjustments for patients characteristics' and pre- and post-operative clinical and pathological findings, higher serum levels of folate were independently associated with lower risk for biochemical recurrence (HR = 0.42, 95%CI = 0.20-0.89, P = 0.023. Conclusion In a cohort of men undergoing radical prostatectomy at several VAs across the country, higher serum folate levels were associated with lower PSA and lower risk for biochemical failure. While the source of the folate in the serum in this study is unknown (i.e. diet vs. supplement, these findings, if confirmed, suggest a potential role of folic acid supplementation or increased consumption of folate rich foods to reduce the risk of recurrence.

  7. Folate promotes S-adenosyl methionine reactions and the microbial methylation cycle and boosts ruminants production and reproduction.

    Science.gov (United States)

    Abbasi, Imtiaz Hussain Raja; Abbasi, Farzana; Wang, Lamei; Abd El Hack, Mohamed E; Swelum, Ayman A; Hao, Ren; Yao, Junhu; Cao, Yangchun

    2018-04-23

    Folate has gained significant attention due to its vital role in biological methylation and epigenetic machinery. Folate, or vitamin (B 9 ), is only produced through a de novo mechanism by plants and micro-organisms in the rumen of mature animals. Although limited research has been conducted on folate in ruminants, it has been noted that ruminal synthesis could not maintain folate levels in high yielding dairy animals. Folate has an essential role in one-carbon metabolism and is a strong antiproliferative agent. Folate increases DNA stability, being crucial for DNA synthesis and repair, the methylation cycle, and preventing oxidation of DNA by free radicals. Folate is also critical for cell division, metabolism of proteins, synthesis of purine and pyrimidine, and increasing the de novo delivery of methyl groups and S-adenosylmethionine. However, in ruminants, metabolism of B 12 and B 9 vitamins are closely connected and utilization of folate by cells is significantly affected by B 12 vitamin concentration. Supplementation of folate through diet, particularly in early lactation, enhanced metabolic efficiency, lactational performance, and nutritional quality of milk. Impaired absorption, oxidative degradation, or deficient supply of folate in ruminants affects DNA stability, cell division, homocysteine remethylation to methionine, de novo synthesis of S-adenosylmethionine, and increases DNA hypomethylation, uracil misincorporation into DNA, chromosomal damage, abnormal cell growth, oxidative species, premature birth, low calf weight, placental tube defects, and decreases production and reproduction of ruminant animals. However, more studies are needed to overcome these problems and reduce enormous dietary supplement waste and impaired absorption of folate in ruminants. This review was aimed to highlight the vital role of folic acid in ruminants performance.

  8. Super-Resolution Localization Microscopy of γ-H2AX and Heterochromatin after Folate Deficiency.

    Science.gov (United States)

    Bach, Margund; Savini, Claudia; Krufczik, Matthias; Cremer, Christoph; Rösl, Frank; Hausmann, Michael

    2017-08-08

    Folate is an essential water-soluble vitamin in food and nutrition supplements. As a one-carbon source, it is involved in many central regulatory processes, such as DNA, RNA, and protein methylation as well as DNA synthesis and repair. Deficiency in folate is considered to be associated with an increased incidence of several malignancies, including cervical cancer that is etiologically linked to an infection with "high-risk" human papilloma viruses (HPV). However, it is still not known how a recommended increase in dietary folate after its deprivation affects the physiological status of cells. To study the impact of folate depletion and its subsequent reconstitution in single cells, we used quantitative chromatin conformation measurements obtained by super-resolution fluorescence microscopy, i.e., single molecule localization microscopy (SMLM). As a read-out, we examined the levels and the (re)positioning of γ-H2AX tags and histone H3K9me3 heterochromatin tags after immunostaining in three-dimensional (3D)-conserved cell nuclei. As model, we used HPV16 positive immortalized human keratinocytes that were cultivated under normal, folate deficient, and reconstituted conditions for different periods of time. The results were compared to cells continuously cultivated in standard folate medium. After 13 weeks in low folate, an increase in the phosphorylation of the histone H2AX was noted, indicative of an accumulation of DNA double strand breaks. DNA repair activity represented by the formation of those γ-H2AX clusters was maintained during the following 15 weeks of examination. However, the clustered arrangements of tags appeared to relax in a time-dependent manner. Parallel to the repair activity, the chromatin methylation activity increased as detected by H3K9me3 tags. The progress of DNA double strand repair was accompanied by a reduction of the detected nucleosome density around the γ-H2AX clusters, suggesting a shift from hetero- to euchromatin to allow access

  9. Plasma Folate and Vitamin B12 Levels in Patients with Hepatocellular Carcinoma

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    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.

  10. Effects of folate and vitamin B12 deficiencies during pregnancy on fetal, infant, and child development.

    Science.gov (United States)

    Molloy, Anne M; Kirke, Peadar N; Brody, Lawrence C; Scott, John M; Mills, James L

    2008-06-01

    The importance of folate in reproduction can be appreciated by considering that the existence of the vitamin was first suspected from efforts to explain a potentially fatal megaloblastic anemia in young pregnant women in India. Today, low maternal folate status during pregnancy and lactation remains a significant cause of maternal morbidity in some communities. The folate status of the neonate tends to be protected at the expense of maternal stores; nevertheless, there is mounting evidence that inadequate maternal folate status during pregnancy may lead to low infant birthweight, thereby conferring risk of developmental and long-term adverse health outcomes. Moreover, folate-related anemia during childhood and adolescence might predispose children to further infections and disease. The role of folic acid in prevention of neural tube defects (NTD) is now established, and several studies suggest that this protection may extend to some other birth defects. In terms of maternal health, clinical vitamin B12 deficiency may be a cause of infertility or recurrent spontaneous abortion. Starting pregnancy with an inadequate vitamin B12 status may increase risk of birth defects such as NTD, and may contribute to preterm delivery, although this needs further evaluation. Furthermore, inadequate vitamin B12 status in the mother may lead to frank deficiency in the infant if sufficient fetal stores of vitamin B12 are not laid down during pregnancy or are not available in breastmilk. However, the implications of starting pregnancy and lactation with low vitamin B12 status have not been sufficiently researched.

  11. Intergenotypic variation of Vitamin B12 and Folate in AD: In north Indian population

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    Neelam Chhillar

    2014-01-01

    Full Text Available Objectives: Changes in lifestyle habits such as diet modification or supplementation have been indicated as probable protective factors for a number of chronic conditions including Alzheimer′s disease (AD. With this background, we aim to hypothesize that whether C677T polymorphism of methylenetetrahydrofolate reductase (MTHFR gene contributes towards the risk of developing AD and its association with vitamin B12 and folate levels. Materials and Methods: A case-control study comprising of total 200 subjects, within the age group of 50-85 years. Their blood samples were analyzed for serum folate, vitamin B12 levels, and MTHFR C677T polymorphism by restriction fragment length polymorphism (RFLP. Results: The mean plasma levels of vitamin B12 and folate were significantly lower in study group when compared to the control group (P < 0.001. Genotypic and allelic frequency of MTHFR gene in both groups was found to be significant (P < 0.05. The intergenotypic variations of vitamin B12 and folate were found to be significant (P < 0.001. Conclusion: We concluded that the subjects with homozygous mutated alleles are more prone to AD and also pointed out the influence of presence/absence of MTHFR T allelic variants on serum folate and vitamin B12 levels.

  12. Serum folate, vitamin B-12 and cognitive function in middle and older age: The HAPIEE study.

    Science.gov (United States)

    Horvat, Pia; Gardiner, Julian; Kubinova, Ruzena; Pajak, Andrzej; Tamosiunas, Abdonas; Schöttker, Ben; Pikhart, Hynek; Peasey, Anne; Jansen, Eugene; Bobak, Martin

    2016-04-01

    Nutrient status of B vitamins, particularly folate and vitamin B-12, may be related to cognitive ageing but epidemiological evidence remains inconclusive. The aim of this study was to estimate the association of serum folate and vitamin B-12 concentrations with cognitive function in middle-aged and older adults from three Central and Eastern European populations. Men and women aged 45-69 at baseline participating in the Health, Alcohol and Psychosocial factors in Eastern Europe (HAPIEE) study were recruited in Krakow (Poland), Kaunas (Lithuania) and six urban centres in the Czech Republic. Tests of immediate and delayed recall, verbal fluency and letter search were administered at baseline and repeated in 2006-2008. Serum concentrations of biomarkers at baseline were measured in a sub-sample of participants. Associations of vitamin quartiles with baseline (n=4166) and follow-up (n=2739) cognitive domain-specific z-scores were estimated using multiple linear regression. After adjusting for confounders, folate was positively associated with letter search and vitamin B-12 with word recall in cross-sectional analyses. In prospective analyses, participants in the highest quartile of folate had higher verbal fluency (pcognitive domains in older Central and Eastern Europeans. These findings do not lend unequivocal support to potential importance of folate and vitamin B-12 status for cognitive function in older age. Long-term longitudinal studies and randomised trials are required before drawing conclusions on the role of these vitamins in cognitive decline. Copyright © 2016. Published by Elsevier Inc.

  13. Interaction of nitrate and folate on the risk of breast cancer among postmenopausal women.

    Science.gov (United States)

    Inoue-Choi, Maki; Ward, Mary H; Cerhan, James R; Weyer, Peter J; Anderson, Kristin E; Robien, Kim

    2012-01-01

    Ingested nitrate can be endogenously reduced to nitrite, which may form N-nitroso compounds, known potent carcinogens. However, some studies have reported no or inverse associations between dietary nitrate intake and cancer risk. These associations may be confounded by a protective effect of folate, which plays a vital role in DNA repair. We evaluated the interaction of dietary and water nitrate intake with total folate intake on breast cancer risk in the Iowa Women's Health Study. Dietary intake was assessed at study baseline. Nitrate intake from public water was assessed using a historical database on Iowa municipal water supplies. After baseline exclusions, 34,388 postmenopausal women and 2,875 incident breast cancers were included. Overall, neither dietary nor water nitrate was associated with breast cancer risk. Among those with folate intake ≥400 μg/day, breast cancer risk was significantly increased in public water users with the highest nitrate quintile (HR = 1.40, 95% CI = 1.05-1.87) and private well users (HR = 1.38, 95% CI = 1.05-1.82) compared to public water users with the lowest nitrate quintile; in contrast, there was no association among those with lower folate intake. Our findings do not support a previous report of increased risk of breast cancer among individuals with high dietary nitrate but low folate intake.

  14. Optimization of the trienzyme extraction for the microbiological assay of folate in vegetables.

    Science.gov (United States)

    Chen, Liwen; Eitenmiller, Ronald R

    2007-05-16

    Response surface methodology was applied to optimize the trienzyme digestion for the extraction of folate from vegetables. Trienzyme extraction is a combined enzymatic digestion by protease, alpha-amylase, and conjugase (gamma-glutamyl hydrolase) to liberate the carbohydrate and protein-bound folates from food matrices for total folate analysis. It is the extraction method used in AOAC Official Method 2004.05 for assay of total folate in cereal grain products. Certified reference material (CRM) 485 mixed vegetables was used to represent the matrix of vegetables. Regression and ridge analysis were performed by statistical analysis software. The predicted second-order polynomial model was adequate (R2 = 0.947), without significant lack of fit (p > 0.1). Both protease and alpha-amylase have significant effects on the extraction. Ridge analysis gave an optimum trienzyme digestion time: Pronase, 1.5 h; alpha-amylase, 1.5 h; and conjugase, 3 h. The experimental value for CRM 485 under this optimum digestion was close to the predicted value from the model, confirming the validity and adequacy of the model. The optimized trienzyme digestion condition was applied to five vegetables and yielded higher folate levels than the trienzyme digestion parameters employed in AOAC Official Method 2004.05.

  15. IMPACT OF FOOD AND FOLATE SUPPLEMENTATION DURING Salmonella TYPHI INFECTION IN Caenorhabditis elegans

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    Bhagavathi Sundaram Sivamaruthi

    2012-06-01

    Full Text Available Caenorhabditis elegans is an instructive and suitable model for studying pathogenesis of almost all human pathogens. Salmonella Typhi is gram-negative facultative intracellular anaerobe that causes several pathetic infections. Necessary enriched nutrient ingestion during pathological conditions may reduce the harshness of the infection. We investigated the impact of folate and food supplementation during S. Typhi infection on the model system, C. elegans. Our data indicated that folate supplementation (10 µg increases the lifespan of S. Typhi infected C. elegans up to 20%. In combination with laboratory food source E. coli OP50, folate increases the infected the worm’s lifespan to 40%. The wild type C. elegans infected by S. Typhi died with the LT50 of 60 ± 12 h. The LT50 of S. Typhi infected folt-1 mutant strain VC959 was 96 ± 6 h. However, the folate supplemented mutant worms exhibited an extended life with LT50 of 120 ± 6 h. The short time exposure and pharyngeal pumping studies confirmed that folt-1 mutant worm exhibited increased survival rate during pathogenic course at significant level when compared to wild-type. Our data revealed that folt-1 plays a significant role in host defense system against S. Typhi infection and the folate supplementation in combination with food increases the host survival during S. Typhi infection.

  16. Changing micronutrient intake through (voluntary) behaviour change. The case of folate.

    Science.gov (United States)

    Jensen, Birger B; Lähteenmäki, Liisa; Grunert, Klaus G; Brown, Kerry A; Timotijevic, Lada; Barnett, Julie; Shepherd, Richard; Raats, Monique M

    2012-06-01

    The objective of this study was to relate behaviour change mechanisms to nutritionally relevant behaviour and demonstrate how the different mechanisms can affect attempts to change these behaviours. Folate was used as an example to illuminate the possibilities and challenges in inducing behaviour change. The behaviours affecting folate intake were recognised and categorised. Behaviour change mechanisms from "rational model of man", behavioural economics, health psychology and social psychology were identified and aligned against folate-related behaviours. The folate example demonstrated the complexity of mechanisms influencing possible behavioural changes, even though this only targets the intake of a single micronutrient. When considering possible options to promote folate intake, the feasibility of producing the desired outcome should be related to the mechanisms of required changes in behaviour and the possible alternatives that require no or only minor changes in behaviour. Dissecting the theories provides new approaches to food-related behaviour that will aid the development of batteries of policy options when targeting nutritional problems. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Developmental consequences of in utero sodium arsenate exposure in mice with folate transport deficiencies

    International Nuclear Information System (INIS)

    Spiegelstein, Ofer; Gould, Amy; Wlodarczyk, Bogdan; Tsie, Marlene; Lu Xiufen; Le, Chris; Troen, Aron; Selhub, Jacob; Piedrahita, Jorge A.; Salbaum, J. Michael; Kappen, Claudia; Melnyk, Stepan; James, Jill; Finnell, Richard H.

    2005-01-01

    Previous studies have demonstrated that mice lacking a functional folate binding protein 2 gene (Folbp2 -/- ) were significantly more sensitive to in utero arsenic exposure than were the wild-type mice similarly exposed. When these mice were fed a folate-deficient diet, the embryotoxic effect of arsenate was further exacerbated. Contrary to expectations, studies on 24-h urinary speciation of sodium arsenate did not demonstrate any significant difference in arsenic biotransformation between Folbp2 -/- and Folbp2 +/+ mice. To better understand the influence of folate pathway genes on arsenic embryotoxicity, the present investigation utilized transgenic mice with disrupted folate binding protein 1 (Folbp1) and reduced folate carrier (RFC) genes. Because complete inactivation of Folbp1 and RFC genes results in embryonic lethality, we used heterozygous animals. Overall, no RFC genotype-related differences in embryonic susceptibility to arsenic exposure were observed. Embryonic lethality and neural tube defect (NTD) frequency in Folbp1 mice was dose-dependent and differed from the RFC mice; however, no genotype-related differences were observed. The RFC heterozygotes tended to have higher plasma levels of S-adenosylhomocysteine (SAH) than did the wild-type controls, although this effect was not robust. It is concluded that genetic modifications at the Folbp1 and RFC loci confers no particular sensitivity to arsenic toxicity compared to wild-type controls, thus disproving the working hypothesis that decreased methylating capacity of the genetically modified mice would put them at increased risk for arsenic-induced reproductive toxicity

  18. DNA methyltransferase mediates dose-dependent stimulation of neural stem cell proliferation by folate.

    Science.gov (United States)

    Li, Wen; Yu, Min; Luo, Suhui; Liu, Huan; Gao, Yuxia; Wilson, John X; Huang, Guowei

    2013-07-01

    The proliferative response of neural stem cells (NSCs) to folate may play a critical role in the development, function and repair of the central nervous system. It is important to determine the dose-dependent effects of folate in NSC cultures that are potential sources of transplantable cells for therapies for neurodegenerative diseases. To determine the optimal concentration and mechanism of action of folate for stimulation of NSC proliferation in vitro, NSCs were exposed to folic acid or 5-methyltetrahydrofolate (5-MTHF) (0-200 μmol/L) for 24, 48 or 72 h. Immunocytochemistry and methyl thiazolyl tetrazolium assay showed that the optimal concentration of folic acid for NSC proliferation was 20-40 μmol/L. Stimulation of NSC proliferation by folic acid was associated with DNA methyltransferase (DNMT) activation and was attenuated by the DNMT inhibitor zebularine, which implies that folate dose-dependently stimulates NSC proliferation through a DNMT-dependent mechanism. Based on these new findings and previously published evidence, we have identified a mechanism by which folate stimulates NSC growth. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Simulation of Food Folate Digestion and Bioavailability of an Oxidation Product of 5-Methyltetrahydrofolate.

    Science.gov (United States)

    Ringling, Christiane; Rychlik, Michael

    2017-09-01

    Generating bioavailability data from in vivo studies is time-consuming and expensive. In vitro simulation can help to investigate factors influencing bioavailability or facilitate quantifying the impact of such factors. For folates, an efficient deconjugation of polyglutamates to the corresponding monoglutamates is crucial for bioavailability and highly dependent on the food matrix. Therefore, the bioaccessibility of folates of different foodstuffs was examined using a simulated digestion model with respect to folate stability and the efficiency of deconjugation. For realistic simulated deconjugation, porcine brush border membrane was used during the phase of the simulated digestion in the small intestine. For a better understanding of folate behaviour during digestion, single folate monoglutamates were also investigated with this in vitro digestion model. The results for bioaccessibility were compared with data from a human bioavailability study. They support the idea that both stability and deconjugation have an influence on bioaccessibility and thus on bioavailability. Tetrahydrofolate is probably lost completely or at least to a high extent and the stability of 5-methyltetrahydrofolate depends on the food matrix. Additionally, 5-methyltetrahydrofolate can be oxidised to a pyrazino-s-triazine (MeFox), whose absorption in the human intestinal tract was shown tentatively.

  20. Cysteine peptidases and their inhibitors in breast and genital cancer.

    Directory of Open Access Journals (Sweden)

    Magdalena Milan

    2010-11-01

    Full Text Available Cysteine proteinases and their inhibitors probably play the main role in carcinogenesis and metastasis. The metastasis process need external proteolytic activities that pass several barriers which are membranous structures of the connective tissue which includes, the basement membrane of blood vessels. Activities of the proteinases are regulated by endogenous inhibitors and activators. The imbalance between cysteine proteinases and cystatins seems to be associated with an increase in metastatic potential in some tumors. It has also been reported that proteinase inhibitors, specific antibodies for these enzymes and inhibition of the urokinase receptor may prevent cancer cell invasion. Some proteinase inhibitor could serve as agents for cancer treatment.

  1. Neither Folic Acid Supplementation nor Pregnancy Affects the Distribution of Folate Forms in the Red Blood Cells of Women1–3

    OpenAIRE

    Hartman, Brenda A.; Fazili, Zia; Pfeiffer, Christine M.; O’Connor, Deborah L.

    2014-01-01

    It is not known whether folate metabolism is altered during pregnancy to support increased DNA and RNA biosynthesis. By using a state-of-the-art LC tandem mass spectrometry technique, the aim of this study was to investigate differences in RBC folate forms between pregnant and nonpregnant women and between nonpregnant women consuming different concentrations of supplemental folic acid. Forms of folate in RBCs were used to explore potential shifts in folate metabolism during early erythropoies...

  2. Folate content in faba beans (Vicia faba L.)—effects of cultivar, maturity stage, industrial processing, and bioprocessing

    Science.gov (United States)

    Hefni, Mohammed E; Shalaby, Mohamed T; Witthöft, Cornelia M

    2015-01-01

    Faba beans are an important source of folate and commonly consumed in Egypt. This study examined the effects of Egyptian industrial food processing (e.g., canning and freezing), germination, cultivar, and maturity stages on folate content, with the aim to develop a candidate functional canned faba bean food with increased folate content. The folate content in four cultivars of green faba beans ranged from 110 to 130 μg 100 g−1 fresh weight (535–620 μg 100 g−1 dry matter [DM]), which was four- to sixfold higher than in dried seeds. Industrial canning of dried seeds resulted in significant folate losses of ∼20% (P = 0.004), while industrial freezing had no effect. Germination of faba beans increased the folate content by >40% (P beans resulted in a net folate content of 194 μg 100 g−1 DM, which is 52% more than in conventional canned beans. The consumption of green faba beans should be recommended, providing ∼120 μg dietary folate equivalents per 100 g/portion. PMID:25650294

  3. Folate content in faba beans (Vicia faba L.)-effects of cultivar, maturity stage, industrial processing, and bioprocessing.

    Science.gov (United States)

    Hefni, Mohammed E; Shalaby, Mohamed T; Witthöft, Cornelia M

    2015-01-01

    Faba beans are an important source of folate and commonly consumed in Egypt. This study examined the effects of Egyptian industrial food processing (e.g., canning and freezing), germination, cultivar, and maturity stages on folate content, with the aim to develop a candidate functional canned faba bean food with increased folate content. The folate content in four cultivars of green faba beans ranged from 110 to 130 μg 100 g(-1) fresh weight (535-620 μg 100 g(-1) dry matter [DM]), which was four- to sixfold higher than in dried seeds. Industrial canning of dried seeds resulted in significant folate losses of ∼20% (P = 0.004), while industrial freezing had no effect. Germination of faba beans increased the folate content by >40% (P beans resulted in a net folate content of 194 μg 100 g(-1) DM, which is 52% more than in conventional canned beans. The consumption of green faba beans should be recommended, providing ∼120 μg dietary folate equivalents per 100 g/portion.

  4. High-level folate production in fermented foods by the B12 producer Lactobacillus reuteri JCM1112

    NARCIS (Netherlands)

    Santos, F.; Wegkamp, A.; de Vos, W.M.; Smid, E.J.; Hugenholtz, J.

    2008-01-01

    We observed that Lactobacillus reuteri JCM1112 produces B12 and folate. However, the folate/B12 mass ratio found was far below that desired for human consumption (~170:1). We used metabolic engineering applying genetic and physiological approaches to improve this ratio and developed a generic and

  5. Dietary folate and choline status differentially affect lipid metabolism and behavior-mediated neurotransmitters in young rats

    Science.gov (United States)

    The relationship between choline and folate metabolisms is an important issue due to the essential role of these nutrients in brain plasticity and cognitive functions. Present study was designed to investigate whether modification of the dietary folate-choline status in young rats would affect brain...

  6. Explaining the variability in recommended intakes of folate, vitamin B12, iron and zinc for adults and elderly people

    NARCIS (Netherlands)

    Doets, E.L.; Cavelaars, A.J.E.M.; Dhonukshe-Rutten, R.A.M.; Veer, van 't P.; Groot, de C.P.G.M.

    2012-01-01

    Objective To signal key issues for harmonising approaches for establishing micronutrient recommendations by explaining observed variation in recommended intakes of folate, vitamin B12, Fe and Zn for adults and elderly people. Design We explored differences in recommended intakes of folate, vitamin

  7. The Vitamin D–Folate Hypothesis as an Evolutionary Model for Skin Pigmentation: An Update and Integration of Current Ideas

    Directory of Open Access Journals (Sweden)

    Patrice Jones

    2018-04-01

    Full Text Available Vitamin D is unique in being generated in our skin following ultraviolet radiation (UVR exposure. Ongoing research into vitamin D must therefore always consider the influence of UVR on vitamin D processes. The close relationship between vitamin D and UVR forms the basis of the “vitamin D–folate hypothesis”, a popular theory for why human skin colour has evolved as an apparent adaption to UVR environments. Vitamin D and folate have disparate sensitivities to UVR; whilst vitamin D may be synthesised following UVR exposure, folate may be degraded. The vitamin D–folate hypothesis proposes that skin pigmentation has evolved as a balancing mechanism, maintaining levels of these vitamins. There are several alternative theories that counter the vitamin D–folate hypothesis. However, there is significant overlap between these theories and the now known actions of vitamin D and folate in the skin. The focus of this review is to present an update on the vitamin D–folate hypothesis by integrating these current theories and discussing new evidence that supports associations between vitamin D and folate genetics, UVR, and skin pigmentation. In light of recent human migrations and seasonality in disease, the need for ongoing research into potential UVR-responsive processes within the body is also discussed.

  8. Genetic and epigenetic alterations of the reduced folate carrier in untreated diffuse large B-cell lymphoma

    DEFF Research Database (Denmark)

    Kastrup, Ingelise Bjerring; Worm, Jesper; Ralfkiaer, Elisabeth

    2007-01-01

    The reduced folate carrier (RFC) is a transmembrane protein that mediates cellular uptake of reduced folates and antifolate drugs, including methotrexate (MTX). Acquired alterations of the RFC gene have been associated with resistance to MTX in cancer cell lines and primary osteosarcomas. Here, we...

  9. Partitioning of One-Carbon Units in Folate and Methionine Metabolism Is Essential for Neural Tube Closure

    Directory of Open Access Journals (Sweden)

    Kit-Yi Leung

    2017-11-01

    Full Text Available Summary: Abnormal folate one-carbon metabolism (FOCM is implicated in neural tube defects (NTDs, severe malformations of the nervous system. MTHFR mediates unidirectional transfer of methyl groups from the folate cycle to the methionine cycle and, therefore, represents a key nexus in partitioning one-carbon units between FOCM functional outputs. Methionine cycle inhibitors prevent neural tube closure in mouse embryos. Similarly, the inability to use glycine as a one-carbon donor to the folate cycle causes NTDs in glycine decarboxylase (Gldc-deficient embryos. However, analysis of Mthfr-null mouse embryos shows that neither S-adenosylmethionine abundance nor neural tube closure depend on one-carbon units derived from embryonic or maternal folate cycles. Mthfr deletion or methionine treatment prevents NTDs in Gldc-null embryos by retention of one-carbon units within the folate cycle. Overall, neural tube closure depends on the activity of both the methionine and folate cycles, but transfer of one-carbon units between the cycles is not necessary. : Leung at al. find that embryonic neural tube closure depends both on the supply of one-carbon units to the folate cycle from glycine cleavage and on the methionine cycle. In contrast, transfer of one-carbon units from the folate cycle to the methionine cycle by MTHFR is dispensable. Keywords: one-carbon metabolism, folic acid, neural tube defects, spina bifida, glycine cleavage system, non-ketotic hyperglycinemia, eye, Mthfr, Gldc

  10. Consortium analysis of gene and gene–folate interactions in purine and pyrimidine metabolism pathways with ovarian carcinoma risk

    DEFF Research Database (Denmark)

    Kelemen, Linda E; Terry, Kathryn L; Goodman, Marc T

    2014-01-01

    SCOPE: We reevaluated previously reported associations between variants in pathways of one-carbon (1-C) (folate) transfer genes and ovarian carcinoma (OC) risk, and in related pathways of purine and pyrimidine metabolism, and assessed interactions with folate intake. METHODS AND RESULTS: Odds rat...

  11. Relationship between cobalamin-dependent metabolites and both serum albumin and alpha1 -proteinase inhibitor concentrations in hypocobalaminemic dogs of 7 different breeds.

    Science.gov (United States)

    Grützner, Niels; Suchodolski, Jan S; Steiner, Jörg M

    2014-12-01

    Increased serum concentrations of homocysteine (HCY) and methylmalonic acid (MMA), the 2 main cobalamin-dependent metabolites, as well as decreased serum albumin and canine alpha1 -proteinase inhibitor (cα1 -PI) concentrations have previously been described in hypocobalaminemic dogs with gastrointestinal disease. However, no studies have been conducted to evaluate potential relationships between these serum biomarkers. The aim of this study was to evaluate the relationship between HCY and MMA, 2 cobalamin-dependent metabolites, and both serum albumin and cα1 -PI concentrations in hypocobalaminemic dogs. Serum samples from 285 dogs including 7 different breeds (Beagle, Boxer, Cocker Spaniel, German Shepherd, Labrador Retriever, Chinese Shar-Pei, and Yorkshire Terrier) with hypocobalaminemia were used. Serum HCY, MMA, albumin, and cα1 -PI concentrations were determined. There was a significant correlation between serum HCY and albumin concentrations, as well as serum HCY and cα1 -PI concentrations (ρ = 0.62 and ρ = 0.37, respectively; P  .05). In addition, significant breed-specific correlations were observed between serum MMA and albumin concentrations in German Shepherds, and serum HCY and MMA concentrations in Chinese Shar-Peis with hypocobalaminemia. This study shows a correlation between serum albumin and cα1 -PI and HCY concentrations, but not with serum MMA concentration in dogs with hypocobalaminemia. In addition, significant breed-specific correlations were observed between serum MMA and albumin concentrations in German Shepherds, as well as serum HCY and MMA concentrations in Chinese Shar-Peis, emphasizing the unique metabolic interactions in those dog breeds affected by hypocobalaminemia. © 2014 American Society for Veterinary Clinical Pathology.

  12. Synthesis and evaluation of {sup 99m}Tc-labeled folate-tripeptide conjugate as a folate receptor-targeeted imaging agent in a tumor-bearing mouse model

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myoung Hyoun; Kim, Chang Guhn; Kim, Dae Weung [Dept. of Nuclear Medicine, Wonkwang University School of Medicine, Iksan (Korea, Republic of); Kim, Woo Hyoung [Dept. of Nuclear Medicine, Seoul National University Hospital, Seoul (Korea, Republic of)

    2015-09-15

    The folate receptor (FR) is an attractive molecular target since it is overexpressed in a variety of human tumors. The purpose of the present study was to synthesize and evaluate the feasibility of a novel {sup 99m}Tc-ECG-EDA (Glu-Cys-Gly-ethylenediamine)-folate as an FR-positive tumor imaging agent in a mouse tumor model. ECG-EDA-folate was synthesized using solid phase peptide synthesis (SPPS) and radiolabeled with {sup 99m}Tc using tripeptide ECG as a chelator. FR-positive KB cells were inoculated in athymic nude mice. Following injection of {sup 99m}Tc-ECG-EDA-folate, serial scintigraphy and micro-SPECT/CT imaging were performed at various time points with and without pre-administration of excess free folate. Mean count densities (MCD) for regions of interest drawn on KB tumors and major normal organs at each time point were measured, and uptake ratios of tumor to normal organs were calculated. ECG-EDA-folate was labeled with {sup 99m}Tc with high radiolabeling efficiency and stability (>96 %). FR-positive tumors were clearly visualized on both scintigraphy and micro-SPECT/CT images and the tumor uptake of {sup 99m}Tc-ECG-EDA-folate was markedly suppressed with faint visualization of tumors by pre-administration of excess free folate on serial planar scintigraphy, indicating FR-specific binding of the agent. Furthermore, semiquantitative analysis of MCD data showed again that both tumor MCD and tumor-to-normal organ ratios decreased considerably by pre-administration of excess free folate, supporting FR-specific tumor uptake. Tumor-to-normal organ ratios approximately increased with time after injection until 4 h. The present study demonstrated that 9{sup 99m}Tc-ECG-EDA-folate can bind specifically to FR with clear visualization of FR-positive tumors in a mouse tumor model.

  13. The relationship between cerebrovascular disease and homocysteine, folate and vitamin B12 in serum

    International Nuclear Information System (INIS)

    Wang Wei; Yang Chen; Shi Yizhen; Liu Zengli

    2005-01-01

    To investigate the relationship between cerebrovascular disease and the serum levels of homocysteine(Hcy), folate and vitamin B 12 , the serum levels of Hcy, folate and vitamin B 12 in 148 patients with cerebrovascular disease were measured by fluorescence polarization immuno- assay and chemiluminescence and were compared with those in healthy controls. The result showed that the serum Hcy levels in patients with cerebral infarction, cerebral hemorrhage and vertebrobasilar ischemiay were significantly higher than those in healthy controls (P 12 levels were signifieantly lower (P 0.05). No significantly higher ratio of increased Hcy levels was observed in patient with complications (P> 0.05). Our conclusion is that hyperhomocysteinemia may be a new and an independent risk factor for cerebrovascular disease. The serum Hcy level is correlated with decreased levels of folate and vitamin B 12 but not obviously correlated with hypertension, diabetes and coronary heart disease. (authors)

  14. Detection of Dysplastic Intestinal Adenomas Using a Fluorescent Folate Imaging Probe

    Directory of Open Access Journals (Sweden)

    Wei-Tsung Chen

    2005-01-01

    Full Text Available Macrophages have long been recognized as a prominent component of tumors. Activated macrophages overexpress folate receptors and we used this phenomenon to image inflammatory reactions in colon dysplasia using a fluorescent folate probe (FFP. APCΔ468 mice injected with FFP showed fluorescent adenomas (target-to-background ratio, adenoma vs. adjacent normal mucosa, of 2.46 ± 0.41, significantly higher (p < .001 than adenomas in animals injected with a non-folate-containing control probe. Fluorescence-activated cell-sorting analysis revealed a 3-fold higher content of Mac1-positive cells in colonic adenomas compared with normal adjacent mucosa (6.8% vs. 2.2%, and confirmed the source of FFP-positive cells to be primarily an F4/80-positive macrophage subpopulation. Taken together, these results indicate that FFP potentially can be used to image dysplastic intestinal adenomas in vivo.

  15. Quantification of isotope-labelled and unlabelled folates in plasma, ileostomy and food samples.

    Science.gov (United States)

    Büttner, Barbara E; Öhrvik, Veronica E; Witthöft, Cornelia M; Rychlik, Michael

    2011-01-01

    New stable isotope dilution assays were developed for the simultaneous quantitation of [(13)C(5)]-labelled and unlabelled 5-methyltetrahydrofolic acid, 5-formyltetrahydrofolic acid, folic acid along with unlabelled tetrahydrofolic acid and 10-formylfolic acid in clinical samples deriving from human bioavailability studies, i.e. plasma, ileostomy samples, and food. The methods were based on clean-up by strong anion exchange followed by LC-MS/MS detection. Deuterated analogues of the folates were applied as the internal standards in the stable isotope dilution assays. Assay sensitivity was sufficient to detect all relevant folates in the respective samples as their limits of detection were below 0.62 nmol/L in plasma and below 0.73 μg/100 g in food or ileostomy samples. Quantification of the [(13)C(5)]-label in clinical samples offers the possibility to differentiate between folate from endogenous body pools and the administered dose when executing bioavailability trials.

  16. Folate receptor targeting silica nanoparticle probe for two-photon fluorescence bioimaging

    Science.gov (United States)

    Wang, Xuhua; Yao, Sheng; Ahn, Hyo-Yang; Zhang, Yuanwei; Bondar, Mykhailo V.; Torres, Joseph A.; Belfield, Kevin D.

    2010-01-01

    Narrow dispersity organically modified silica nanoparticles (SiNPs), diameter ~30 nm, entrapping a hydrophobic two-photon absorbing fluorenyl dye, were synthesized by hydrolysis of triethoxyvinylsilane and (3-aminopropyl)triethoxysilane in the nonpolar core of Aerosol-OT micelles. The surface of the SiNPs were functionalized with folic acid, to specifically deliver the probe to folate receptor (FR) over-expressing Hela cells, making these folate two-photon dye-doped SiNPs potential candidates as probes for two-photon fluorescence microscopy (2PFM) bioimaging. In vitro studies using FR over-expressing Hela cells and low FR expressing MG63 cells demonstrated specific cellular uptake of the functionalized nanoparticles. One-photon fluorescence microscopy (1PFM) imaging, 2PFM imaging, and two-photon fluorescence lifetime microscopy (2P-FLIM) imaging of Hela cells incubated with folate-modified two-photon dye-doped SiNPs were demonstrated. PMID:21258480

  17. Vitamin B12 and folate levels in normal population of northern Pakistan

    International Nuclear Information System (INIS)

    Madood-ul-mannan; Anwar, M.; Saleem, M.; Waqar, A.; Ahmad, M.

    1990-01-01

    Diagnosis of vitamin B12 or folate deficiency can not be made unless reference ranges of these vitamins in a given population are known. These serum levels depend upon the dietary intake of these vitamins which in turn depends upon the availability of foods containing these vitamins and the methods of cooking/processing. The latter vary in different populations. Therefore serum level of these vitamins would vary in different populations. Serum levels of vitamin B12 and folate were estimated by radioimmunoassay technique in 30 normal subjects of different age groups. The levels of vitamin B12 were found to be 215.2 pg/ml and that of folate 3.9 ng/ml. These values are much lower than those described for European population. It is therefore concluded that the cut off point of the levels of these vitamins should be different than the European figures. (author)

  18. Estimation of folate binding capacity (unsaturated and total) in normal human serum and in β-thalassaemia

    International Nuclear Information System (INIS)

    Moulopoulos, S.; Mantzos, J.; Gyftaki, E.; Kesse-Elias, M.; Alevizou-Terzaki, V.; Souli-Tsimili, E.

    1978-01-01

    A method is described for measuring the total serum folate binding capacity (TBC) after treating the serum with urea at pH5.5, the unsaturated serum folate binding capacity (UBC) being determined without treatment with urea. The method was applied to 50 normal controls and 20 patients with homozygous β-thalassaemia. The results show an increase in folate binding capacity after treating the serum with urea in all cases studied. There is no correlation between serum folic acid level and total or unsaturated folate binding capacity or per cent saturation. The method described is a simple and rapid one for screening the different groups studied for saturated and unsaturated specific folate-binding proteins. (author)

  19. Micronutrient mineral and folate content of Australian and imported dried fruit products.

    Science.gov (United States)

    Bennett, Louise E; Singh, Davinder P; Clingeleffer, Peter R

    2011-01-01

    A selection of Australian and imported fresh and dried fruit products, including sultanas, Sunmuscats, Carina currants, Zante currants, apricots, and prunes, were analyzed for selected minerals (Ca, Mg, Na, S, B, Al, Fe, Mn, Cu, Zn, Mo, and Se), folate and vitamin C, and the capacity of dried fruits for dietary provision of these micronutrients evaluated. Micro-nutrients were concentrated by a factor of 3-5 in dried fruits compared with their fresh fruit counterparts and were consequently present in nutritionally significant levels, in contrast to fresh fruit. Australian dried sultanas, Carina currant, Zante currant, apricots, and prunes contained Cu, Fe, K, and Mn at levels of >20% of daily Required Dietary Intake (RDI, taken as the average for adult men and women as nominated by the Australian National Health and Medical Research Council) and Sunmuscats contained Cu, Fe, and K at >20% of RDI. All dried fruits studied contained boron in the range of 1.5 to 5.4 mg per 100 g; however, the RDI for boron has not been defined by the NHMRC at the present time. All sultanas and currants studied contained folate at levels of 10-20% of RDI per 100 g. Experimental drying methods significantly affected folate levels with higher folate content in non-ground versus ground-based drying methods. Of the micro-nutrients supplying >20% of RDI, folate represents a particular nutrient for which the mean daily intake of adult Australians is typically inadequate. This study shows that dried fruit consumption, in contrast with fresh fruit, can provide significant proportions of daily requirements of several micronutrients, particularly folate.

  20. Homocysteine Lowering by Folate-Rich Diet or Pharmacological Supplementations in Subjects with Moderate Hyperhomocysteinemia

    Directory of Open Access Journals (Sweden)

    Lorenza Mistura

    2013-05-01

    Full Text Available To compare the efficacy of a diet rich in natural folate and of two different folic acid supplementation protocols in subjects with “moderate” hyperhomocysteinemia, also taking into account C677T polymorphism of 5,10-methylenetetrahydrofolate reductase (MTHFR gene. Subjects/Methods: We performed a 13 week open, randomized, double blind clinical trial on 149 free living persons with mild hyperhomocyteinemia, with daily 200 μg from a natural folate-rich diet, 200 μg [6S]5-methyltetrahydrofolate (5-MTHF, 200 μg folic acid or placebo. Participants were stratified according to their MTHFR genotype. Results: Homocysteine (Hcy levels were reduced after folate enriched diet, 5-MTHF or folic acid supplementation respectively by 20.1% (p < 0.002, 19.4% (p < 0.001 and 21.9% (p < 0.001, as compared to baseline levels and significantly as compared to placebo (p < 0.001, p < 0.002 and p < 0.001, respectively for enriched diet, 5-MTHF and folic acid. After this enriched diet and the folic acid supplementation, Hcy in both genotype groups decreased approximately to the same level, with higher percentage decreases observed for the TT group because of their higher pre-treatment value. Similar results were not seen by genotype for 5-MTHF. A significant increase in RBC folate concentration was observed after folic acid and natural folate-rich food supplementations, as compared to placebo. Conclusions: Supplementation with natural folate-rich foods, folic acid and 5-MTHF reached a similar reduction in Hcy concentrations.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. The Rickettsia Endosymbiont of Ixodes pacificus Contains All the Genes of De Novo Folate Biosynthesis

    Science.gov (United States)

    Bodnar, James; Mortazavi, Bobak; Laurent, Timothy; Deason, Jeff; Thephavongsa, Khanhkeo; Zhong, Jianmin

    2015-01-01

    Ticks and other arthropods often are hosts to nutrient providing bacterial endosymbionts, which contribute to their host’s fitness by supplying nutrients such as vitamins and amino acids. It has been detected, in our lab, that Ixodes pacificus is host to Rickettsia species phylotype G021. This endosymbiont is predominantly present, and 100% maternally transmitted in I. pacificus. To study roles of phylotype G021 in I. pacificus, bioinformatic and molecular approaches were carried out. MUMmer genome alignments of whole genome sequence of I. scapularis, a close relative to I. pacificus, against completely sequenced genomes of R. bellii OSU85-389, R. conorii, and R. felis, identified 8,190 unique sequences that are homologous to Rickettsia sequences in the NCBI Trace Archive. MetaCyc metabolic reconstructions revealed that all folate gene orthologues (folA, folC, folE, folKP, ptpS) required for de novo folate biosynthesis are present in the genome of Rickettsia buchneri in I. scapularis. To examine the metabolic capability of phylotype G021 in I. pacificus, genes of the folate biosynthesis pathway of the bacterium were PCR amplified using degenerate primers. BLAST searches identified that nucleotide sequences of the folA, folC, folE, folKP, and ptpS genes possess 98.6%, 98.8%, 98.9%, 98.5% and 99.0% identity respectively to the corresponding genes of Rickettsia buchneri. Phylogenetic tree constructions show that the folate genes of phylotype G021 and homologous genes from various Rickettsia species are monophyletic. This study has shown that all folate genes exist in the genome of Rickettsia species phylotype G021 and that this bacterium has the genetic capability for de novo folate synthesis. PMID:26650541

  3. Cysteine-free peptides in scorpion venom: geographical distribution ...

    African Journals Online (AJOL)

    GRACE

    2006-12-29

    Dec 29, 2006 ... In 1993, the first cysteine-free peptide was isolated from scorpion venom. ..... Venom is produced by 2 venom glands in the tail and stored in 2 ... The resistance of a variety of bacterial micro-organisms .... Biopolymers 55: 4-30.

  4. A Serendipitous Formation of a Cysteine-bridged Disaccharide

    African Journals Online (AJOL)

    NICO

    O-acetyl-b-D-glucopyranosylisothiouronium salt and the iodide or tosyl derivatives of L-serine,3 the desulfurization of disulfide- linked glycosyl cysteine derivatives,4 Lewis acid-catalyzed glycosylation,5,6 and solid phase glycosylation.7. Glycosylation of amino acids has previously relied on the use of amino acids protected ...

  5. Isolation of recombinant cysteine dioxygenase protein from Trichophyton mentagrophytes

    Czech Academy of Sciences Publication Activity Database

    Kašperová, A.; Kunert, J.; Horynová, M.; Weigl, E.; Sebela, M.; Lenobel, René; Raška, M.

    2011-01-01

    Roč. 54, č. 5 (2011), E456-E462 ISSN 0933-7407 R&D Projects: GA ČR GA301/08/1649 Institutional research plan: CEZ:AV0Z50380511 Keywords : Cysteine dioxygenase * dermatophytes * recombinant protein * keratinolytic fungi * cDNA Subject RIV: CE - Biochemistry Impact factor: 2.247, year: 2011

  6. Cysteine Protease Inhibitors as Chemotherapy: Lessons from a Parasite Target

    Science.gov (United States)

    Selzer, Paul M.; Pingel, Sabine; Hsieh, Ivy; Ugele, Bernhard; Chan, Victor J.; Engel, Juan C.; Bogyo, Matthew; Russell, David G.; Sakanari, Judy A.; McKerrow, James H.

    1999-09-01

    Papain family cysteine proteases are key factors in the pathogenesis of cancer invasion, arthritis, osteoporosis, and microbial infections. Targeting this enzyme family is therefore one strategy in the development of new chemotherapy for a number of diseases. Little is known, however, about the efficacy, selectivity, and safety of cysteine protease inhibitors in cell culture or in vivo. We now report that specific cysteine protease inhibitors kill Leishmania parasites in vitro, at concentrations that do not overtly affect mammalian host cells. Inhibition of Leishmania cysteine protease activity was accompanied by defects in the parasite's lysosome/endosome compartment resembling those seen in lysosomal storage diseases. Colocalization of anti-protease antibodies with biotinylated surface proteins and accumulation of undigested debris and protease in the flagellar pocket of treated parasites were consistent with a pathway of protease trafficking from flagellar pocket to the lysosome/endosome compartment. The inhibitors were sufficiently absorbed and stable in vivo to ameliorate the pathology associated with a mouse model of Leishmania infection.

  7. Chemical detection of cysteine-rich circular petides in selected ...

    African Journals Online (AJOL)

    Cysteine-rich circular peptides (CRCs) comprise a large family of gene encoded and low molecular weight polypeptides that has recently engaged the attention of scientists. This class of peptides exhibit a continuous circular configuration and a cystine knot backbone, which defines their resilient nature-directed structural ...

  8. Targeting cysteine proteases in trypanosomatid disease drug discovery.

    Science.gov (United States)

    Ferreira, Leonardo G; Andricopulo, Adriano D

    2017-12-01

    Chagas disease and human African trypanosomiasis are endemic conditions in Latin America and Africa, respectively, for which no effective and safe therapy is available. Efforts in drug discovery have focused on several enzymes from these protozoans, among which cysteine proteases have been validated as molecular targets for pharmacological intervention. These enzymes are expressed during the entire life cycle of trypanosomatid parasites and are essential to many biological processes, including infectivity to the human host. As a result of advances in the knowledge of the structural aspects of cysteine proteases and their role in disease physiopathology, inhibition of these enzymes by small molecules has been demonstrated to be a worthwhile approach to trypanosomatid drug research. This review provides an update on drug discovery strategies targeting the cysteine peptidases cruzain from Trypanosoma cruzi and rhodesain and cathepsin B from Trypanosoma brucei. Given that current chemotherapy for Chagas disease and human African trypanosomiasis has several drawbacks, cysteine proteases will continue to be actively pursued as valuable molecular targets in trypanosomatid disease drug discovery efforts. Copyright © 2017. Published by Elsevier Inc.

  9. Chemoselective PEGylation of Cysteine Analogs of Human Basic ...

    African Journals Online (AJOL)

    Purpose: To improve the stability and bioactivity of human basic fibroblast growth factor (hbFGF) by site-specific pegylation. Methods: Four new mutants of hbFGF were designed with substituted Asp68, Lys77, Glu78 and Arg81 with cysteine with the aid of bioinformatics technique, and then cloned into pET21a plasmid, ...

  10. Baseline investigations of folate status in Aboriginal and non-Aboriginal West Australians prior to the introduction of mandatory fortification.

    Science.gov (United States)

    Maxwell, Susannah J; Brameld, Kate J; Bower, Caroline; D'Antoine, Heather; Hickling, Siobhan; Marley, Julia; O'Leary, Peter

    2013-02-01

    In September 2009, Australia implemented mandatory folic acid fortification of wheat flour for bread-making to reduce the incidence of neural tube defects. Our study aimed to establish baseline folate status data in Aboriginal and non-Aboriginal Western Australians. Patients who presented at a health service or collection centre for blood tests were invited to participate. One hundred and ninety-one Aboriginals and 159 non-Aboriginals were recruited between April 2008 and September 2009. Participants completed a five-minute questionnaire and had blood taken for red blood cell (RBC) folate and serum vitamin B12. Data were analysed using SPSS (version 17.0.2, SPSS Inc., Chicago, IL, USA). Ten per cent (95% confidence intervals (CI): 5, 19) of the Aboriginal women participants and 26% (95% CI: 16, 40) of men had RBC folate concentrations below 250 ng/mL, the cut-off associated with folate deficiency. None of the non-Aboriginal women (95% CI: 0, 4) and 4% of the non-Aboriginal men (95% CI: 2, 12) had RBC folate concentrations below 250 ng/mL. All participants were vitamin B12 replete. None of the 96 Aboriginal and 8% of non-Aboriginal women aged 16-44 reported consumption of supplements with a daily intake of >400 μg folic acid during the previous week. This study established a baseline of RBC folate, folate consumption and supplement use in Aboriginal and non-Aboriginal groups. We identified 10% of Aboriginal women and none of non-Aboriginal women participants with low folate concentrations. The higher prevalence of folate deficiency in Aboriginal participants suggests they are more likely to benefit from a universal program of folate fortification. © 2012 The Authors ANZJOG © 2012 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

  11. MTHFR Gene and Serum Folate Interaction on Serum Homocysteine Lowering: Prospect for Precision Folic Acid Treatment.

    Science.gov (United States)

    Huang, Xiao; Qin, Xianhui; Yang, Wenbin; Liu, Lishun; Jiang, Chongfei; Zhang, Xianglin; Jiang, Shanqun; Bao, Huihui; Su, Hai; Li, Ping; He, Mingli; Song, Yun; Zhao, Min; Yin, Delu; Wang, Yu; Zhang, Yan; Li, Jianping; Yang, Renqang; Wu, Yanqing; Hong, Kui; Wu, Qinhua; Chen, Yundai; Sun, Ningling; Li, Xiaoying; Tang, Genfu; Wang, Binyan; Cai, Yefeng; Hou, Fan Fan; Huo, Yong; Wang, Hong; Wang, Xiaobin; Cheng, Xiaoshu

    2018-03-01

    This post hoc analysis of the CSPPT (China Stroke Primary Prevention Trial) assessed the individual variation in total homocysteine (tHcy)-lowering response after an average 4.5 years of 0.8 mg daily folic acid therapy in Chinese hypertensive adults and evaluated effect modification by methylenetetrahydrofolate reductase ( MTHFR ) C677T genotypes and serum folate levels. This analysis included 16 413 participants from the CSPPT, who were randomly assigned to 2 double-blind treatment groups: either 10-mg enalapril+0.8-mg folic acid or 10-mg enalapril, daily and had individual measurements of serum folate and tHcy levels at baseline and exit visits and MTHFR C677T genotypes. Mean baseline tHcy levels were comparable between the 2 treatment groups (14.5±8.5 versus 14.4±8.1 μmol/L; P =0.561). After 4.5 years of treatment, mean tHcy levels were reduced to 12.7±6.1 μmol/L in the enalapril+folic acid group, but almost stayed the same in the enalapril group (14.4±7.9 μmol/L, group difference: 1.61 μmol/L; 11% reduction). More importantly, tHcy lowering varied by MTHFR genotypes and serum folate levels. Compared with CC and CT genotypes, participants with the TT genotype had a more prominent L-shaped curve between tHcy and serum folate levels and required higher folate levels (at least 15 ng/mL) to eliminate the differences in tHcy by genotypes. Compared with CC or CT, tHcy in the TT group manifested a heightened L-shaped curve from low to high folate levels, but this difference in tHcy by genotype was eliminated when plasma folate levels reach ≈15 ng/mL or higher. Our data raised the prospect to tailor folic acid therapy according to individual MTHFR C677T genotype and folate status. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00794885. © 2018 American Heart Association, Inc.

  12. Genetic architecture of vitamin B12 and folate levels uncovered applying deeply sequenced large datasets

    DEFF Research Database (Denmark)

    Grarup, Niels; Sulem, Patrick; Sandholt, Camilla H

    2013-01-01

    of the underlying biology of human traits and diseases. Here, we used a large Icelandic whole genome sequence dataset combined with Danish exome sequence data to gain insight into the genetic architecture of serum levels of vitamin B12 (B12) and folate. Up to 22.9 million sequence variants were analyzed in combined...... in serum B12 or folate levels do not modify the risk of developing these conditions. Yet, the study demonstrates the value of combining whole genome and exome sequencing approaches to ascertain the genetic and molecular architectures underlying quantitative trait associations....

  13. Cysteine and hydrogen sulfide in the regulation of metabolism:Insights from genetics and pharmacology

    OpenAIRE

    Carter, Roderick N; Morton, Nicholas M

    2016-01-01

    Abstract Obesity and diabetes represent a significant and escalating worldwide health burden. These conditions are characterized by abnormal nutrient homeostasis. One such perturbation is altered metabolism of the sulphur?containing amino acid cysteine. Obesity is associated with elevated plasma cysteine, whereas diabetes is associated with reduced cysteine levels. One mechanism by which cysteine may act is through its enzymatic breakdown to produce hydrogen sulphide (H2S), a gasotransmitter ...

  14. Mutagenicity and cytotoxicity of two regioisomeric mercapturic acids and cysteine S-conjugates of trichloroethylene.

    NARCIS (Netherlands)

    Commandeur, J.N.M.; Boogaard, P.J.; Mulder, G.J.; Vermeulen, N.P.E.

    1991-01-01

    The mutagenicity, cytotoxicity and metabolism of two regioisomic l-cysteine- and N-acetyl-l-cysteine-S-conjugates of trichloroethylene were studied. The 1,2-dichlorovinyl(1,2-DCV) isomers of both the cysteine conjugate and the mercapturate were much stronger mutagens in the Ames test with Salmonella

  15. Effects of cysteine on growth, protease production, and catalase activity of Pseudomonas fluorescens.

    OpenAIRE

    Himelbloom, B H; Hassan, H M

    1986-01-01

    Cysteine inhibits growth of and protease production by Pseudomonas fluorescens NC3. Catalase activity in P. fluorescens NC3 was increased by cysteine. The addition of exogenous hydrogen peroxide did not increase catalase activity, thus suggesting a role for the endogenous generation of hydrogen peroxide via the autoxidation of cysteine.

  16. Bioaccessibility of Folic Acid and (6S)-5-Methyltetrahydrofolate Decreases after the Addiction of Folate-Binding Protein to Yogurt as Studied in a Dynamic In Vitro Gastrointestinal Model

    NARCIS (Netherlands)

    Arkbåge, K.; Verwei, M.; Havenaar, R.; Witthöft, C.

    2003-01-01

    Milk products are only moderate sources of folate. Nevertheless, they are of interest due to their content of folate-binding proteins (FBP), which in some studies have been reported to increase folate bioavailability. The effect of FBP on folate bioavailability has been widely discussed. The aim of

  17. Bioaccessibility of Folic Acid and (6S)-5-Methyltetrahydrofolate Decreases after the Addition of Folate-Binding Protein to Yogurt as Studied in a Dynamic in Vitro Gastrointestinal Model

    NARCIS (Netherlands)

    Arkbåge, K.; Verwei, M.; Havenaar, R.; Witthöft, C.

    2003-01-01

    Milk products are only moderate sources of folate. Nevertheless, they are of interest due to their content of folate-binding proteins (FBP), which in some studies have been reported to increase folate bioavailability. The effect of FBP on folate bioavailability has been widely discussed. The aim of

  18. Neither folic acid supplementation nor pregnancy affects the distribution of folate forms in the red blood cells of women.

    Science.gov (United States)

    Hartman, Brenda A; Fazili, Zia; Pfeiffer, Christine M; O'Connor, Deborah L

    2014-09-01

    It is not known whether folate metabolism is altered during pregnancy to support increased DNA and RNA biosynthesis. By using a state-of-the-art LC tandem mass spectrometry technique, the aim of this study was to investigate differences in RBC folate forms between pregnant and nonpregnant women and between nonpregnant women consuming different concentrations of supplemental folic acid. Forms of folate in RBCs were used to explore potential shifts in folate metabolism during early erythropoiesis. Total RBC folate and folate forms [tetrahydrofolate; 5-methyltetrahydrofolate (5-methyl-THF); 4α-hydroxy-5-methyl-tetrahydrofolate (an oxidation product of 5-methyl-THF); 5-formyl-tetrahydrofolate; and 5,10-methenyl-tetrahydrofolate] were measured in 4 groups of women (n = 26): pregnant women (PW) (30-36 wk of gestation) consuming 1 mg/d of folic acid, and nonpregnant women consuming 0 mg/d (NPW-0), 1 mg/d (NPW-1), and 5 mg/d (NPW-5) folic acid. The mean ± SD RBC folate concentration of the NPW-0 group (890 ± 530 nmol/L) was lower than the NPW-1 (1660 ± 350 nmol/L) and NPW-5 (1980 ± 570 nmol/L) groups as assessed by microbiologic assay (n = 26, P methyl-THF [limit of detection (LOD) = 0.06 nmol/L] in all groups and tetrahydrofolate (LOD = 0.2 nmol/L) in most women regardless of methylenetetrahydrofolate reductase genotype. Most women consuming folic acid supplements had detectable concentrations of 5,10-methenyl-tetrahydrofolate (LOD = 0.31 nmol/L). However, there was no difference in the relative distribution of 5-methyl-THF (83-84%), sum of non-methyl folates (0.6-3%), or individual non-methyl folate forms in RBCs across groups. We conclude that although folic acid supplementation in nonpregnant women increases RBC total folate and the concentration of individual folate forms, it does not alter the relative distribution of folate forms. Similarly, distribution of RBC folate forms did not differ between pregnant and nonpregnant women. This trial was registered at

  19. Barley (Hordeum vulgare L.) cysteine proteases: heterologous expression, purification and characterization

    DEFF Research Database (Denmark)

    Rosenkilde, Anne Lind; Dionisio, Giuseppe; Holm, Preben Bach

    2011-01-01

    During germination of barley seeds, mobilization of protein is essential and cysteine proteases accounts for more than 90 % of the total proteolytic activity in the degradation of barley seed storage proteins. Cysteine proteases exist as pro-enzyme and is activated through reduction of the active...... site cysteines and by removal of the pro-domain. The complement of cysteine proteases is comprehensive and for detailed studies of the individual components of this complement, a fast and efficient eukaryotic expression platform is highly desirable. A cDNA clone of the barley key cysteine endoprotease...

  20. Betaine is as effective as folate at re-synthesizing methionine for protein synthesis during moderate methionine deficiency in piglets.

    Science.gov (United States)

    McBreairty, Laura E; Robinson, Jason L; Harding, Scott V; Randell, Edward W; Brunton, Janet A; Bertolo, Robert F

    2016-12-01

    Both folate and betaine (synthesized from choline) are nutrients used to methylate homocysteine to reform the amino acid methionine following donation of its methyl group; however, it is unclear whether both remethylation pathways are of equal importance during the neonatal period when remethylation rates are high. Methionine is an indispensable amino acid that is in high demand in neonates not only for protein synthesis, but is also particularly important for transmethylation reactions, such as creatine and phosphatidylcholine synthesis. The objective of this study was to determine whether supplementation with folate, betaine, or a combination of both can equally re-synthesize methionine for protein synthesis when dietary methionine is limiting. Piglets were fed a low methionine diet devoid of folate, choline, and betaine, and on day 6, piglets were supplemented with either folate, betaine, or folate + betaine (n = 6 per treatment) until day 10. [1- 13 C]-phenylalanine oxidation was measured as an indicator of methionine availability for protein synthesis both before and after 2 days of supplementation. Prior to supplementation, piglets had lower concentrations of plasma folate, betaine, and choline compared to baseline with no change in homocysteine. Post-supplementation, phenylalanine oxidation levels were 20-46 % lower with any methyl donor supplementation (P = 0.006) with no difference among different supplementation groups. Furthermore, both methyl donors led to similarly lower concentrations of homocysteine following supplementation (P folate to remethylate methionine for protein synthesis, as indicated by lower phenylalanine oxidation.

  1. Aleurone flour increases red-cell folate and lowers plasma homocyst(e)ine substantially in man.

    Science.gov (United States)

    Fenech, Michael; Noakes, Manny; Clifton, Peter; Topping, David

    2005-03-01

    Aleurone flour (ALF) is a rich source of natural folate (>500 microg/100 g wet weight). Our objective was to establish whether intake of ALF in man can significantly improve folate status and reduce plasma homocyst(e)ine. We performed a randomised, controlled intervention, of 16 weeks duration, in free-living healthy individuals (mean age 46-52 years). Participants were assigned to one of three groups: ALF, 175 g bread made with ALF and placebo tablet each day; PCS, 175 g bread made with pericarp seed coat (PCS) flour and placebo tablet each day (low-folate control); or FA, 175 g bread made with PCS flour and tablet containing 640 microg folic acid each day (high-folate control). The daily folate intake contributed by the bread and tablet was 233 microg in the PCS group, 615 microg in the ALF group and 819 microg in the FA group. The number of participants completing all phases of the PCS, ALF and FA interventions was twenty-five, twenty-five and eighteen, respectively. Plasma and red-cell folate increased significantly (Pine decreased significantly (Pine in the ALF group decreased from 9.1 (8.2, 10.0) micromol/l at baseline to 6.8 (6.2, 7.5) micromol/l after 16 weeks. In conclusion, moderate dietary intake of ALF can increase red-cell folate and decrease plasma homocyst(e)ine substantially.

  2. Lifestyle and genetic determinants of folate and vitamin B12 levels in a general adult population

    DEFF Research Database (Denmark)

    Thuesen, Betina H; Husemoen, Lise Lotte N; Ovesen, Lars

    2009-01-01

    and the prevalence was lower with increasing age. Low serum folate was associated with smoking, low alcohol intake, high coffee intake, unhealthy diet, and the TT genotype of the methylenetetrahydrofolate reductase (MTHFR)-C677T polymorphism. The overall prevalence of low serum vitamin B12 (

  3. The importance of (early) folate status to primary and secondary coronary artery disease prevention

    NARCIS (Netherlands)

    Muskiet, FAJ

    2005-01-01

    Folate, methionine, betaine, choline, zinc and Vitamins B-12, B-6 and B-2 are involved in one-carbon metabolism, which includes S-adenosylmethionine (SAM) substrated methylation. Inadequate enzyme activities and imbalances of substrates and cofactors in one-carbon metabolism, together referred to as

  4. Folate, cancer risk, and the greek god, Proteus: a tale of two chameleons

    Science.gov (United States)

    Evidence indicates that an abundant intake of foodstuffs rich in folate conveys protection against the development of colorectal cancer, and perhaps some other common cancers as well. The issue is a complex one however, since some observations in animal and human studies demonstrate that an overly ...

  5. Obesity is associated with increased red blood cell folate despite lower dietary intakes and serum concentrations

    Science.gov (United States)

    Although obesity is prevalent worldwide, few studies have investigated whether obesity interacts with status of the B vitamin, folate. Based on data from the nationally representative NHANES survey, this study examined the association between a measure of obesity (body mass index [BMI],) factors ass...

  6. Vitamin B12, folate, and homocysteine in depression: the Rotterdam Study

    NARCIS (Netherlands)

    H.W. Tiemeier (Henning); H.R. van Tuijl (Ruud); J. Meijer (John); A.J. Kiliaan (Amanda); M.M.B. Breteler (Monique); A. Hofman (Albert)

    2002-01-01

    textabstractOBJECTIVE: The associations of vitamin B(12), folate, and homocysteine with depression were examined in a population-based study. METHOD: The authors screened 3,884 elderly people for depressive symptoms. Subjects with positive screening results had psychiatric workups.

  7. Blood folate is associated with asymptomatic or partially symptomatic Alzheimer's disease in the Nun study.

    Science.gov (United States)

    Wang, Huifen; Odegaard, Andrew; Thyagarajan, Bharat; Hayes, Jennifer; Cruz, Karen Santa; Derosiers, Mark F; Tyas, Suzanne L; Gross, Myron D

    2012-01-01

    Asymptomatic and partially symptomatic Alzheimer's disease (APSYMAD) are a series of cognitive states wherein subjects have substantial Alzheimer's disease (AD) pathology (classification B or C by the Consortium to Establish a Registry for AD criteria), but have normal or only partially impaired cognitive function; all of these subjects are non-demented. These cognitive states may arise from the prevention or delay of clinical symptom expression by exposure to certain nutritional factors. This study examined blood levels of folate and antioxidants (i.e., carotenoids) in relation to APSYMAD, nested in the Nun study, a longitudinal study of aging and AD. Sixty elderly female subjects, who had AD on the basis of neuropathology exams, were included. Following adjustment for APOE4 status, education level, and age at blood draw, subjects with the highest blood folate levels had a higher likelihood of being in the APSYMAD group as compared to the demented (AD) group (odds ratio = 1.09, 95% CI = 1.00-1.18. p < 0.06). This association was not significantly influenced by additional adjustment for blood concentrations of carotenoids. Restriction of the population to subjects with near normal cognition on the cognitive state score (score = 1-3) indicated an elevated association with blood folate (odds ratio = 1.12, 95% CI = 1.01-1.25, p < 0.04). Blood carotenoids were not associated with APSYMAD. Thus, folate status may influence the expression of clinical symptoms of AD disease and aid in the delay or prevention of dementia.

  8. The interrelationship between ligand binding and self-association of the folate binding protein

    DEFF Research Database (Denmark)

    Holm, Jan; Schou, Christian; Babol, Linnea N.

    2011-01-01

    The folate binding protein (FBP) regulates homeostasis and intracellular trafficking of folic acid, a vitamin of decisive importance in cell division and growth. We analyzed whether interrelationship between ligand binding and self-association of FBP plays a significant role in the physiology of ...

  9. Baicalin loaded in folate-PEG modified liposomes for enhanced stability and tumor targeting

    Czech Academy of Sciences Publication Activity Database

    Chen, Y.; Minh, L. V.; Liu, J.; Angelov, Borislav; Drechsler, M.; Garamus, V. M.; Willumeit-Römer, R.; Zou, A.

    2016-01-01

    Roč. 140, 1 April (2016), s. 74-82 ISSN 0927-7765 R&D Projects: GA ČR(CZ) GC15-10527J Institutional support: RVO:61389013 Keywords : baicalin * liposomes * folate receptor Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.887, year: 2016

  10. Prospective study on dietary intakes of folate, betaine, and choline and cardiovascular disease risk in women.

    NARCIS (Netherlands)

    Dalmeijer, G.W.; Olthof, M.R.; Verhoef, P.; Bots, M.L.; van der Schouw, Y.T.

    2008-01-01

    Objective: To investigate the association between dietary intakes of folate, betaine and choline and the risk of cardiovascular disease (CVD). Design: Prospective cohort study. Subjects: A total of 16165 women aged 49-70 years without prior CVD. Subjects were breast cancer screening participants in

  11. Oral facial clefts and gene polymorphisms in metabolism of folate/one-carbon and vitamin A

    DEFF Research Database (Denmark)

    Boyles, Abee L; Wilcox, Allen J; Taylor, Jack A

    2009-01-01

    An increased risk of facial clefts has been observed among mothers with lower intake of folic acid or vitamin A around conception. We hypothesized that the risk of clefts may be further moderated by genes involved in metabolizing folate or vitamin A. We included 425 case-parent triads in which th...

  12. Autoantibodies to folate receptor alpha during early pregnancy and risk of oral clefts in Denmark

    DEFF Research Database (Denmark)

    Bille, Camilla; Pedersen, Dorthe Almind; Andersen, Anne-Marie Nybo

    2010-01-01

    The objective of this study was to determine whether IgG and IgM autoantibodies to folate receptor alpha (FRalpha) in pregnant women are associated with an increased risk of oral cleft-affected offspring. A case-control study nested in the prospective Danish National Birth Cohort (100,418 pregnan...

  13. Methionine synthase A2756G and reduced folate carrier1 A80G ...

    African Journals Online (AJOL)

    Aim of the study: To analyze the effect of methionine synthase (MTR) A2756G, and reduced folate carrier (RFC1) A80G gene polymorphisms on the maternal risk for DS. Patients: This study was conducted in the Medical Genetics Center, Ain-Shams University hospitals, on a total of 170 mothers of children, diagnosed with ...

  14. Cellular imaging and folate receptor targeting delivery of gum kondagogu capped gold nanoparticles in cancer cells.

    Science.gov (United States)

    Kumar, Sathish Sundar Dhilip; Mahesh, Ayyavu; Antoniraj, M Gover; Rathore, Hanumant Singh; Houreld, N N; Kandasamy, Ruckmani

    2018-04-01

    In this study, the green synthesis of gum kondagogu capped gold nanoparticles (GK-GNPs) was prepared using a naturally available polysaccharide. The anionic gum capped GK-GNPs enabled the successful coupling of folic acid (FA) and fluorescein isothiocyanate (FITC) to produce a fluorescently labelled GNP (F2-GNP). F2-GNPs were further characterized using different physicochemical methods Cellular viability, cellular imaging, and targeted delivery of F2-GNPs were further evaluated in both folate receptor positive (MCF-7) and folate receptor negative (A549) cancer cells. Physicochemical characterization revealed a nanoparticle with a small size (37 nm), smooth surface (surface charge of -23.7 mV), crystallinity of gold nanoparticles and existence of gum kondagogu in the F2-GNPs. Cellular uptake of F2-GNPs indicated a greater affinity towards folate receptor positive cells. This study shows that the F2-GNPs is as an effective nanocarrier for targeted drug delivery and cellular imaging via folate receptors. Copyright © 2017. Published by Elsevier B.V.

  15. CoFactor: Folate Requirement for Optimization of 5-Fluouracil Activity in Anticancer Chemotherapy

    Directory of Open Access Journals (Sweden)

    Muhammad Wasif Saif

    2010-01-01

    Full Text Available Intracellular reduced folate exists as a “pool” of more than 6 interconvertable forms. One of these forms, 5,10 methylenetetrahydrofolic acid (CH2THF, is the key one-carbon donor and reduced folate substrate for thymidylate synthase (TS. This pathway has been an important target for chemotherapy as it provides one of the necessary nucleotide substrates for DNA synthesis. The fluoropyrimidine 5-fluorouracil (5-FU exerts its main cytotoxic activity through TS inhibition. Leucovorin (5-formyltetrahydrofolate; LV has been used to increase the intracellular reduced folate pools and enhance TS inhibition. However, it must be metabolized within the cell through multiple intracellular enzymatic steps to form CH2THF. CoFactor (USAN fotrexorin calcium, (dl-5,10,-methylenepteroyl-monoglutamate calcium salt is a reduced folate that potentiates 5-FU cytotoxicity. According to early clinical trials, when 5-FU is modulated by CoFactor instead of LV, there is greater anti-tumor activity and less toxicity. This review presents the emerging role of CoFactor in colorectal and nongastrointestinal malignancies.

  16. Folate intake, alcohol and risk of breast cancer among postmenopausal women in Denmark

    DEFF Research Database (Denmark)

    Tjønneland, A; Christensen, J.; Olsen, A.

    2006-01-01

    There is consistent evidence that alcohol increases the risk of breast cancer. It has been suggested that the increased risk associated with alcohol intake may be reduced by adequate intake of folate. Since many women consume alcohol, detection of a risk-reducing mechanism would have major public...

  17. A prospective cohort study on antioxidant and folate intake and male lung cancer risk

    NARCIS (Netherlands)

    Voorrips, L.E.; Goldbohm, R.A.; Brants, H.A.M.; Poppel, G.A.F.C. van; Sturmans, F.; Hermus, R.J.J.; Brandt, P.A. van den

    2000-01-01

    Many studies have reported inverse associations between vegetable and fruit consumption and lung cancer risk. The aim of the present study was to elucidate the role of several antioxidants and folate in this relationship. In the Netherlands Cohort Study on Diet and Cancer, 58,279 men of ages 55-69

  18. Periconception Maternal Folate Status and Human Embryonic Cerebellum Growth Trajectories : The Rotterdam Predict Study

    NARCIS (Netherlands)

    Koning, Irene V; Groenenberg, Irene A L; Gotink, Anniek W; Willemsen, Sten P; Gijtenbeek, Manon; Dudink, Jeroen; Go, Attie T J I; Reiss, Irwin K M; Steegers, Eric A P; Steegers-Theunissen, Régine P M

    2015-01-01

    We aimed to investigate whether periconceptional maternal folate status affects human embryonic cerebellar size and growth trajectories. In a prospective periconceptional cohort participants filled out questionnaires and received weekly transvaginal 3D-ultrasounds between 7+0 and 12+6 weeks

  19. Clinical Significances of Serum Vitamin B12, Folate and Ferritin Levels in Patients with Malignant Tumors

    International Nuclear Information System (INIS)

    Monn, Youn Sung; Soung, In Whan; Kim, Sam Yong; Ro, Heung Kyu; Lee, Bok Hee

    1987-01-01

    In order to evaluate the clinical significances of the serum vitamin B 12 , folate and ferritin levels in patients with malignant tumors, the levels were measured in 10 normal control subjects, 70 patients with malignant tumors, 7 patients with liver cirrhosis and 25 patients with other benign diseases. The results are as follows: 1) In normal control subjects, mean serum values for vitamin B 12 , folate and ferritin level were 588.80±131.58 pg/ml, 5.59±1.52 ng/ml and 89.22±42.78 ng/ml retrospectively. 2) There was no significant difference in serum levels between patients with benign diseases and normal control subjects. 3) The serum vitamin B 12 and ferritin levels in patients with liver cirrhosis were significantly higher than in normal control, and the serum folate levels in these patients were lower than in normal control subjects. 4) The serum vitamin B 12 and ferritin levels in patients with malignant tumors were significantly higher than in normal control subjects, and the serum folate levels in these patients were significantly lower than in normal control subjects. The above results suggest that the serum vitamin B 12 and ferritin may be useful as tumor markers in patients with malignant tumors.

  20. Effect of Freezing, Thermal Pasteurization, and Hydrostatic Pressure on Fractionation and Folate Recovery in Egg Yolk.

    Science.gov (United States)

    Naderi, Nassim; Pouliot, Yves; House, James D; Doyen, Alain

    2017-09-06

    In this study, the impact of pasteurization and freezing of raw material, as performed at a commercial scale, on egg yolk fractionation and folate recovery was assessed. Freezing induced denaturation of the lipoproteins in egg yolk, which prevented further fractionation of the yolk. Thermal pasteurization of egg yolk at 61.1 °C for 3.5 min as well as high hydrostatic pressure (HHP) treatment (400 MPa for 5 min) did not change (p < 0.05) the composition of egg yolk or yolk fractions after their recovery by centrifugation. Expressed as dry matter, folate in pasteurized yolk was measured to be 599 μg/100 g, while its concentration reached 1969.7 μg/100 g for pasteurized granule and 1902.5 μg/100 g for HHP-treated granule. Folate was not detected in plasma, emphasizing the complete separation of yolk folate into granule. Further, we studied the effect of HHP on different dilutions of egg yolk, which were then fractionated. Egg yolk was diluted with water at different concentrations (0.1, 1.0, 10, 25, and 50%), HHP-treated at 400 MPa for 5 min, and centrifuged. Characterization of the compositions of the separated granule and plasma followed. Folate was stable under the HHP conditions used. However, HHP caused separation of folate from the yolk structure into water-soluble plasma. After HHP processing, the amount of folate detected in the plasma fraction was significantly (p < 0.05) higher (1434.9 μg/100 g) in the 25% diluted samples but was significantly (p < 0.05) lower in HHP-treated granule samples. Native sodium dodecyl sulfate-polyacrylamide gel electrophoresis results showed that phosvitin, α-livetin, and apovitellenin VIa were the proteins most resistant to HHP. This study confirms that dilution of egg yolk before HHP treatment can significantly (p < 0.05) change the composition of granule and plasma fractions after centrifugal fractionation of egg yolk.

  1. Folate deficiency enhances arsenic effects on expression of genes involved in epidermal differentiation in transgenic K6/ODC mouse skin

    International Nuclear Information System (INIS)

    Nelson, Gail M.; Ahlborn, Gene J.; Delker, Don A.; Kitchin, Kirk T.; O'Brien, Thomas G.; Chen Yan; Kohan, Michael J.; Roop, Barbara C.; Ward, William O.; Allen, James W.

    2007-01-01

    Chronic arsenic exposure in humans is associated with cancers of the skin, lung, bladder and other tissues. There is evidence that folate deficiency may increase susceptibility to arsenic effects, including skin lesions. K6/ODC mice develop skin tumors when exposed to 10 ppm sodium arsenite for 5 months. In the current study, K6/ODC mice maintained on either a folate deficient or folate sufficient diet were exposed to 0, 1, or 10 ppm sodium arsenite in the drinking water for 30 days. Total RNA was isolated from skin samples and gene expression analyzed using Affymetrix Mouse 430 2.0 GeneChips. Data from 24 samples, with 4 mice in each of the 6 treatment groups, were RMA normalized and analyzed by two-way ANOVA using GeneSpring TM . Top gene ontology (GO) categories for genes responding significantly to both arsenic treatment and folate deficiency include nucleotide metabolism and cell organization and biogenesis. For many of these genes, folate deficiency magnifies the response to arsenic treatment. In particular, expression of markers of epidermal differentiation, e.g., loricrin, small proline rich proteins and involucrin, was significantly reduced by arsenic in the folate sufficient animals, and reduced further or at a lower arsenic dose in the folate deficient animals. In addition, expression of a number of epidermal cell growth/proliferation genes and cellular movement genes was altered. These results indicate that arsenic disrupts the normal balance of cell proliferation and differentiation, and that folate deficiency exacerbates these effects, consistent with the view that folate deficiency is a nutritional susceptibility factor for arsenic-induced skin tumorigenesis

  2. Folate deficiency in north Indian children undergoing maintenance chemotherapy for acute lymphoblastic leukemia-Implications and outcome.

    Science.gov (United States)

    Roy Moulik, Nirmalya; Kumar, Archana; Agrawal, Suraksha; Mahdi, Abbas Ali

    2018-01-01

    Treatment-related toxicity and mortality are not uncommon during maintenance chemotherapy for childhood acute lymphoblastic leukemia (ALL), especially in the low- and middle-income countries (LMIC). Undernutrition and micronutrient deficiencies are commonly seen in children from LMICs undergoing treatment for ALL. The present study examines the prevalence and clinical implications of folate deficiency in north Indian children with ALL during the maintenance phase of treatment in view of prolonged antifolate treatment and high population prevalence of folate deficiency. Pre-cycle folate levels/deficiency as well as weight for age z-score and serum albumin level were determined and correlated with complications of treatment and mortality encountered during the maintenance phase of treatment. Twenty-nine of 52 children enrolled in the study had folate deficiency at some point during maintenance chemotherapy. Neutropenia (18 of 29 vs. 4 of 23; P = 0.002), thrombocytopenia (17 of 29 vs. 4 of 23; P = 0.005), febrile neutropenia (17 of 29 vs. 4 of 23; P = 0.005), and need for chemotherapy dose reduction (20 of 29 vs. 7 of 21; P = 0.01) were more common in folate-deficient children. Maintenance deaths were higher (8 of 29 vs. 1 of 23; P = 0.03) and survival lower (P = 0.02) in deficient children. In multivariate analysis, hypoalbuminemia (P = 0.02) and folate deficiency (P = 0.01) were associated with febrile neutropenia, and folate deficiency with maintenance deaths (P = 0.03). Folate deficiency was associated with treatment-related complications and adverse outcome in our patients. The risks and benefits of folate supplementation in deficient children during maintenance chemotherapy need to be explored with properly designed randomized studies in similar settings. © 2017 Wiley Periodicals, Inc.

  3. Experimental and metabolic modeling evidence for a folate-cleaving side-activity of ketopantoate hydroxymethyltransferase (PanB

    Directory of Open Access Journals (Sweden)

    Jennifer eThiaville

    2016-03-01

    Full Text Available Tetrahydrofolate (THF and its one-carbon derivatives, collectively termed folates, are essential cofact¬ors, but are inherently unstable. While it is clear that chemical oxidation can cleave folates or damage their pterin precursors, very little is known about enzymatic damage to these molec-ules or about whether the folate biosynthesis pathway responds adaptively to damage to its end-pro¬¬ducts. The presence of a duplication of the gene encoding the folate biosynthesis enzyme 6-hydr¬oxymethyl-7,8-dihydropterin pyrophosphokinase (FolK in many sequenced bacterial gen-omes combined with a strong chromosomal clustering of the folK gene with panB, encoding the 5,10-methylene-THF-dependent enzyme ketopantoate hydroxymethyltransferase, led us to infer that PanB has a side activity that cleaves 5,10-methylene-THF, yielding a pterin product that is recycled by FolK. Genetic and metabolic analyses of Escherichia coli strains showed that over-expression of PanB leads to accumulation of the likely folate cleavage product 6-hydroxy¬methyl-pterin and other pterins in cells and medium, and – unexpectedly – to a 46% increase in total fol-ate content. In silico modeling of the folate bio¬syn¬thesis pathway showed that these observations are consistent with the in vivo cleavage of 5,10-methylene-THF by a side-activity of PanB, with FolK-mediated recycling of the pterin cleavage product, and with regulation of folate biosynth-esis by folates or their damage products.

  4. Electrostatics of cysteine residues in proteins: Parameterization and validation of a simple model

    Science.gov (United States)

    Salsbury, Freddie R.; Poole, Leslie B.; Fetrow, Jacquelyn S.

    2013-01-01

    One of the most popular and simple models for the calculation of pKas from a protein structure is the semi-macroscopic electrostatic model MEAD. This model requires empirical parameters for each residue to calculate pKas. Analysis of current, widely used empirical parameters for cysteine residues showed that they did not reproduce expected cysteine pKas; thus, we set out to identify parameters consistent with the CHARMM27 force field that capture both the behavior of typical cysteines in proteins and the behavior of cysteines which have perturbed pKas. The new parameters were validated in three ways: (1) calculation across a large set of typical cysteines in proteins (where the calculations are expected to reproduce expected ensemble behavior); (2) calculation across a set of perturbed cysteines in proteins (where the calculations are expected to reproduce the shifted ensemble behavior); and (3) comparison to experimentally determined pKa values (where the calculation should reproduce the pKa within experimental error). Both the general behavior of cysteines in proteins and the perturbed pKa in some proteins can be predicted reasonably well using the newly determined empirical parameters within the MEAD model for protein electrostatics. This study provides the first general analysis of the electrostatics of cysteines in proteins, with specific attention paid to capturing both the behavior of typical cysteines in a protein and the behavior of cysteines whose pKa should be shifted, and validation of force field parameters for cysteine residues. PMID:22777874

  5. Fluoresence quenching of riboflavin in aqueous solution by methionin and cystein

    International Nuclear Information System (INIS)

    Droessler, P.; Holzer, W.; Penzkofer, A.; Hegemann, P.

    2003-01-01

    The fluorescence quantum distributions, fluorescence quantum yields, and fluorescence lifetimes of riboflavin in methanol, DMSO, water, and aqueous solutions of the sulphur atom containing amino acids methionin and cystein have been determined. In methanol, DMSO, and water (pH=4-8) only dynamic fluorescence reduction due to intersystem crossing and internal conversion is observed. In aqueous methionin solutions of pH=5.25-9 a pH independent static and dynamic fluorescence quenching occurs probably due to riboflavin anion-methionin cation pair formation. In aqueous cystein solutions (pH range from 4.15 to 9) the fluorescence quenching increases with rising pH due to cystein thiolate formation. The cystein thiol form present at low pH does not react with neutral riboflavin. Cystein thiolate present at high pH seems to react with neutral riboflavin causing riboflavin deprotonation (anion formation) by cystein thiolate reduction to the cystein thiol form

  6. Preparation of a folate-mediated tumor targeting ultraparamagnetic polymeric micelles and its in vitro experimental study

    International Nuclear Information System (INIS)

    Hong Guobin; Zhou Jingxing; Shen Jun; Liang Biling; Yuan Renxu; Shuai Xintao

    2008-01-01

    Objective: To evaluate the tumor targeting characteristic of the Folate-SPIO-DOX- Micelles by in vitro studies, and to test the feasibility of monitor tumor targeting using it and clinical MRI. Methods: The polymeric micelles, Folate-SPIO-DOXO-Micelles were prepared. The in vitro tumor cell targeting efficacy of these folate modified and DOX or SPIO-loaded micelles (Folate-SPIO-DOX- MiceUes) was evaluated by observing the cellular uptake of micelles by human hepatic carcinoma cells (Bel 7402 cells) which overexpressed folate surface receptors. Cell suspensions were incubated with Folate-SPIO- DOXO-Micelles for 1 h. Prussian blue staining was performed to show intracellular irons. Flow cytometry was used to further quantify the cellular uptake of the nanoparticles into Bel 7402 cells. MRI was performed to show the signal intensity changes by using T 2 WI sequences at a clinical 1.5 T MR system. Results Prussian blue staining showed much more intracellular iron in cells incubated with Folate-SPIO-DOX- Micelles than the cells incubated with the non-targeting SPIO-DOX-Micelles. As revealed by flow cytometry, the mean fluorescence intensity of cells in the folate group and the non-folate group were 117.88 and 46. 33, respectively. The T 2 signal intensity in MRI of cells treated with the folate targeting micelles decreased significantly(when the concentration of SPIO in cell culture medium was 5, 10, 20, 40, and 80 μg/ml, respectively, T 2 signal intensity decreased by -5.02%, -23.58%, -45.89%, -70.34%, and -92.41%, respectively). In contrast, T 2 signal intensity did not show obvious decrease for cells treated with the folate-free micelles (when the concentration of SPIO in cell culture medium was at 5, 10, 20, 40, and 80 μg/ml, respectively, T 2 signal intensity decreased by -3.77%, -2.16%, -2.18%, -2.74% and -19.77%, respectively). Conclusion: The polymeric micelles, Folate-SPIO-DOX-Micelles has good targeting ability to the hepatic carcinoma cells in vitro, and

  7. Low-dose radiation potentiates the therapeutic efficacy of folate receptor-targeted hapten therapy.

    Science.gov (United States)

    Sega, Emanuela I; Lu, Yingjuan; Ringor, Michael; Leamon, Christopher P; Low, Philip S

    2008-06-01

    Human cancers frequently overexpress a high-affinity cell-surface receptor for the vitamin folic acid. Highly immunogenic haptens can be targeted to folate receptor-expressing cell surfaces by administration of folate-hapten conjugates, rendering the decorated tumor cell surfaces more recognizable by the immune system. Treatment of antihapten-immunized mice with folate-hapten constructs results in elimination of moderately sized tumors by the immune system. However, when subcutaneous tumors exceed 300 mm(3) before initiation of therapy, antitumor activity is significantly decreased. In an effort to enhance the efficacy of folate-targeted hapten immunotherapy (FTHI) against large tumors, we explored the combination of targeted hapten immunotherapy with low-dose radiotherapy. Mice bearing 300-mm(3) subcutaneous tumors were treated concurrently with FTHI (500 nmol/kg of folate conjugated to fluorescein isothiocyanate, 20,000 U/dose of interleukin 2, and 25,000 U/dose of interferon alpha) and low-dose radiotherapy (3 Gy/dose focused directly on the desired tumor mass). The efficacy of therapy was evaluated by measuring tumor volume. Tumor growth analyses show that radiotherapy synergizes with FTHI in antihapten-immunized mice, thereby allowing for cures of animals bearing tumors greater than 300 mm(3). More importantly, nonirradiated distal tumor masses in animals containing locally irradiated tumors also showed improved response to hapten immunotherapy, suggesting that not all tumor lesions must be identified and irradiated to benefit from the combination therapy. These results suggest that simultaneous treatment with FTHI and radiation therapy can enhance systemic antitumor activity in tumor-bearing mice.

  8. Preclinical development of small-molecular-weight folate-based radioconjugates: a pharmacological perspective

    International Nuclear Information System (INIS)

    Siwowska, K.; Müller, C.

    2015-01-01

    The folate receptor (FR) has attracted attention as a target structure because of its frequent expression in cancer cells (FR-α) and activated macrophages (FR-β). The vitamin folic acid has served as a promising targeting ligand allowing selective delivery of attached radionuclides suitable for imaging of the diseased sites and for therapeutic application. A large number of folate radioconjugates with variable chemical structures have been developed over the last 25 years. Accumulation of radioactivity in healthy organs and tissues was always seen in the kidneys due to the expression of the FR in the proximal tubule cells. In some cases unspecific uptake of radio folates was also seen in the liver and the intestinal tract. To address this situation and improve the target-to-off-target ratios of accumulated radioactivity several strategies were undertaken, including chemical modifications of the folate conjugates, selection of appropriate radionuclides and application of drug combinations. Depending on the radionuclide which was employed various chelators and linker entities were investigated and additional functionalities with albumin-binding properties were tested with the aim to increase the serum half-life of the radioconjugates. A number of diagnostic radionuclides (99mTc, 111In, 67Ga, 155Tb, 125I) emitting γ-radiation were employed for single photon emission computed tomography (SPECT) and, β+-emitting radionuclides (68Ga, 44Sc, 152Tb, 18F) were used for positron emission tomography (PET). Moreover, therapeutic radionuclides emitting β--particles (177Lu, 161Tb, 47Sc, 131I) and α-particles (149Tb) were also used with folate conjugates. The present review focuses on the development of radiofolates and their in vivo properties and on strategies which were employed to modify their pharmacokinetic and pharmacodynamic properties.

  9. Improving the uptake of preconception care and periconceptional folate supplementation: what do women think?

    Directory of Open Access Journals (Sweden)

    Chapman Anna

    2010-12-01

    Full Text Available Abstract Background Despite strong evidence of the benefits of preconception interventions to improve pregnancy outcomes, the delivery and uptake of preconception care in general and periconceptional folate supplementation in particular remains low. The aim of this study was to determine women's views of the barriers and enablers to the uptake of preconception care and periconceptional folate supplementation. Methods Focus groups were undertaken in 2007 with 17 women of reproductive age (18-45 years. To identify key issues and themes within the data, focus groups were analysed using an inductive process of thematic analysis. Results Most women were unaware of the need to attend for preconception care and were surprised at the breadth of issues involved. Women also felt general practitioners (GPs should be more proactive in promoting preconception care availability but acknowledged that they themselves had to be thinking about pregnancy or becoming pregnant to be receptive to it. Barriers to periconceptional folate supplementation included confusion about reasons for use, dose, duration, timing and efficacy of folate use. Enablers included the desire to do anything they could to ensure optimum pregnancy outcomes, and promotional material and letters of invitation from their GP to advise them of the availability and the need for preconception care. Conclusion A number of important barriers and enablers exist for women regarding the delivery and uptake of preconception care and periconceptional folate supplementation. It is essential that these patient perspectives are addressed in both the implementation of evidence based clinical practice guidelines and in the systematic design of an intervention to improve preconception care delivery.

  10. Low-Dose Radiation Potentiates the Therapeutic Efficacy of Folate Receptor-Targeted Hapten Therapy

    International Nuclear Information System (INIS)

    Sega, Emanuela I.; Lu Yingjuan; Ringor, Michael; Leamon, Christopher P.; Low, Philip S.

    2008-01-01

    Purpose: Human cancers frequently overexpress a high-affinity cell-surface receptor for the vitamin folic acid. Highly immunogenic haptens can be targeted to folate receptor-expressing cell surfaces by administration of folate-hapten conjugates, rendering the decorated tumor cell surfaces more recognizable by the immune system. Treatment of antihapten-immunized mice with folate-hapten constructs results in elimination of moderately sized tumors by the immune system. However, when subcutaneous tumors exceed 300 mm 3 before initiation of therapy, antitumor activity is significantly decreased. In an effort to enhance the efficacy of folate-targeted hapten immunotherapy (FTHI) against large tumors, we explored the combination of targeted hapten immunotherapy with low-dose radiotherapy. Methods and Materials: Mice bearing 300-mm 3 subcutaneous tumors were treated concurrently with FTHI (500 nmol/kg of folate conjugated to fluorescein isothiocyanate, 20,000 U/dose of interleukin 2, and 25,000 U/dose of interferon α) and low-dose radiotherapy (3 Gy/dose focused directly on the desired tumor mass). The efficacy of therapy was evaluated by measuring tumor volume. Results: Tumor growth analyses show that radiotherapy synergizes with FTHI in antihapten-immunized mice, thereby allowing for cures of animals bearing tumors greater than 300 mm 3 . More importantly, nonirradiated distal tumor masses in animals containing locally irradiated tumors also showed improved response to hapten immunotherapy, suggesting that not all tumor lesions must be identified and irradiated to benefit from the combination therapy. Conclusions: These results suggest that simultaneous treatment with FTHI and radiation therapy can enhance systemic antitumor activity in tumor-bearing mice

  11. Metabolism and gene polymorphisms of the folate pathway in Brazilian women with history of recurrent abortion.

    Science.gov (United States)

    Boas, Wendell Vilas; Gonçalves, Rozana Oliveira; Costa, Olívia Lúcia Nunes; Goncalves, Marilda Souza

    2015-02-01

    To investigate the association between polymorphisms in genes that encode enzymes involved in folate- and vitamin B12-dependent homocysteine metabolism and recurrent spontaneous abortion (RSA). We investigated the C677T and A1298C polymorphisms of the methylenetetrahydrofalate reductase gene (MTHFR), the A2756G polymorphism of the methionine synthase gene (MS) and the 844ins68 insertion of the cystathionine beta synthetase gene (CBS). The PCR technique followed by RFLP was used to assess the polymorphisms; the serum levels of homocysteine, vitamin B12 and folate were investigated by chemiluminescence. The EPI Info Software version 6.04 was used for statistical analysis. Parametric variables were compared by Student's t-test and nonparametric variables by the Wilcoxon rank sum test. The frequencies of gene polymorphisms in 89 women with a history of idiopathic recurrent miscarriage and 150 controls were 19.1 and 19.6% for the C677T, insertion, 20.8 and 26% for the A1298C insertion, 14.2 and 21.9% for the A2756G insertion, and 16.4 and 18% for the 844ins68 insertion, respectively. There were no significant differences between case and control groups in any of the gene polymorphisms investigated. However, the frequency of the 844ins68 insertion in the CBS gene was higher among women with a history of loss during the third trimester of pregnancy (p=0.003). Serum homocysteine, vitamin B12 and folate levels id not differ between the polymorphisms studied in the case and control groups. However, linear regression analysis showed a dependence of serum folate levels on the maintenance of tHcy levels. The investigated gene polymorphisms and serum homocysteine, vitamin B12 and folate levels were not associated with idiopathic recurrent miscarriage in the present study. Further investigations are needed in order to confirm the role of the CBS 844ins68 insertion in recurrent miscarriage.

  12. Genotoxicity testing of peptides: Folate deprivation as a marker of exaggerated pharmacology

    International Nuclear Information System (INIS)

    Guérard, Melanie; Zeller, Andreas; Festag, Matthias; Schubert, Christine; Singer, Thomas; Müller, Lutz

    2014-01-01

    The incidence of micronucleated-cells is considered to be a marker of a genotoxic event and can be caused by direct- or indirect-DNA reactive mechanisms. In particular, small increases in the incidence of micronuclei, which are not associated with toxicity in the target tissue or any structurally altering properties of the compound, trigger the suspicion that an indirect mechanism could be at play. In a bone marrow micronucleus test of a synthetic peptide (a dual agonist of the GLP-1 and GIP receptors) that had been integrated into a regulatory 13-week repeat-dose toxicity study in the rat, small increases in the incidence of micronuclei had been observed, together with pronounced reductions in food intake and body weight gain. Because it is well established that folate plays a crucial role in maintaining genomic integrity and pronounced reductions in food intake and body weight gain were observed, folate levels were determined from plasma samples initially collected for toxicokinetic analytics. A dose-dependent decrease in plasma folate levels was evident after 4 weeks of treatment at the mid and high dose levels, persisted until the end of the treatment duration of 13-weeks and returned to baseline levels during the recovery period of 4 weeks. Based on these properties, and the fact that the compound tested (peptide) per se is not expected to reach the nucleus and cause DNA damage, the rationale is supported that the elevated incidence of micronucleated polychromatic erythrocytes is directly linked to the exaggerated pharmacology of the compound resulting in a decreased folate level. - Highlights: • A synthetic peptide has been evaluated for potential genotoxicity • Small increases in an integrated (13-weeks) micronucleus test were observed • Further, animals had a pronounced reductions in food intake and body weight gain • A dose-dependent decrease in plasma folate levels was evident from week 4 onwards • Elevated micronuclei-incidence due to the

  13. Circulating folate levels and colorectal adenoma: a case-control study and a meta-analysis.

    Science.gov (United States)

    Park, Yeong Mi; Youn, Jiyoung; Cho, Chang Ho; Kim, Sung Hi; Lee, Jung Eun

    2017-10-01

    The relationship between folate and colorectal neoplasia remains controversial. We examined the association between serum folate concentrations and colorectal adenomas in a case-control study of Korean adults and conducted a meta-analysis. Our case-control study included 113 pairs of case and control who underwent colonoscopy and provided blood samples. We used multivariable conditional logistic regression models to obtain the odds ratios and 95% confidence interval (CIs). For meta-analysis, we identified the relevant studies by searching the PubMed database up to February 2017, included our case-control study and combined the study-specific relative risks (RRs) using a random-effects model. In this case-control study, we included 58 men and 55 women with colorectal adenomas and sex and fasting status matched the controls. We did not find any significant association between the serum folate levels and colorectal adenomas in either men or women. For meta-analysis, a total of eleven studies were included in our analysis and classified into two groups; polyp clearance group (PC) for the studies that included participants who underwent endoscopies and had their polyps removed at baseline; and no polyp clearance group (NPC) for the studies that included participants whose histories of endoscopies were unknown or who underwent their first endoscopies. Four PC (1,311 cases and 1,672 non-cases) and eight NPC studies (3,501 cases and 11,347 non-cases) were included. The combined RRs (95% CIs) comparing the bottom with the top categories of circulating folate levels were 1.07 (0.97-1.18) for the NPC group but 1.45 (1.16-1.74) for the PC group. Low circulating folate levels were associated with new adenoma formation.

  14. Affinity labeling of the folate-methotrexate transporter from Leishmania donovani

    International Nuclear Information System (INIS)

    Beck, J.T.; Ullman, B.

    1989-01-01

    An affinity labeling technique has been developed to identify the folate-methotrexate transporter of Leishmania donovani promastigotes using activated derivatives of the ligands. These activated derivatives were synthesized by incubating folate and methotrexate with a 10-fold excess of 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (EDC) for 10 min at ambient temperature in dimethyl sulfoxide. When intact wild-type (DI700) Leishmania donovani or preparations of their membranes were incubated with a 0.4 μM concentration of either activated [ 3 H]folate or activated [ 3 H]methotrexate, the radiolabeled ligands were covalently incorporated into a polypeptide with a molecular weight of approximately 46,000, as demonstrated by SDS-polyacrylamide gel electrophoresis. No affinity labeling of a 46,000-dalton protein was observed when equimolar concentrations of activated radiolabeled ligands were incubated with intact cells or membranes prepared from a methotrexate-resistant mutant clone of Leishmania donovani, MTXA5, that is genetically defective in folate-methotrexate transport capability. Time course studies indicated that maximal labeling of the 46,000-dalton protein occurred within 5-10 min of incubation of intact cells with activated ligand. These studies provide biochemical evidence that the folate-methotrexate transporter of Leishmania donovani can be identified in crude extracts by an affinity labeling technique and serve as a prerequisite to further analysis of the transport protein by providing a vehicle for subsequent purification of this membrane carrier. Moreover, these investigations suggest that the affinity labeling technique using EDC-activated ligands may be exploitable to analyze other cell surface binding proteins in Leishmania donovani, as well as in other organisms

  15. Ex-ante evaluation of biotechnology innovations: the case of folate biofortified rice in China.

    Science.gov (United States)

    De Steur, Hans; Blancquaert, Dieter; Gellynck, Xavier; Lambert, Willy; Van Der Straeten, Dominique

    2012-12-01

    In order to valorize novel biotechnology innovations, there is a need to evaluate ex-ante their market potential. A case in point is biofortification, i.e. the enhancement of the micronutrient content of staple crops through conventional or genetic breeding techniques. In a recent article in Nature Biotechnology, for example, De Steur et al. (2010) demonstrated the large potential consumer health benefits of folate biofortified rice as a means to reduce folate deficiency and Neural-Tube Defects. By focusing on a Chinese high-risk region of Neural-Tube Defects, the current study defines the potential cost-effectiveness of this genetically modified crop where the need to improve folate intake levels is highest. Building on the Disability-Adjusted Life Years (DALY) approach, both the potential health impacts and costs of its implementation are measured and benchmarked against similar innovations. The results show that this transgenic crop could be a highly cost-effective product innovation (US$ 120.34 - US$ 40.1 per DALY saved) to alleviate the large health burden of folate deficiency and reduce the prevalence of neural-tube birth defects. When compared with other biofortified crops and target regions, folate biofortified rice in China has a relatively high health impact and moderate cost-effectiveness. This research further supports the need for, and importance of ex-ante evaluation studies in order to adequately market and, thus, valorize biotechnology innovations. Although the cost-effectiveness analysis enables to illustrate the market potential of innovative agricultural biotechnology research, further research is required to address policy issues on transgenic biofortification, such as biosafety regulatory requirements.

  16. Genetic Polymorphism of Folate and Methionine Metabolizing Enzymes and their Susceptibility to Malignant Lymphoma

    International Nuclear Information System (INIS)

    Habib, E.E.; Aziz, M.; Kotb, M.

    2005-01-01

    Folate and methionine metabolism is involved in DNA synthesis and methylation. Polymorphisms in the genes of folate metabolism enzymes have been associated with some forms of cancer. In the present study, 2 polymorphisms were evaluated for a folate metabolic enzyme, methylene-tetrahydrofolate reductase (MTHFR), and one was evaluated for methionine synthase (MS). The 2 polymorphisms MTHFR 677 C-7T and MTHFR 1298 A-7C, are reported to reduce the enzyme activity, which causes intracellular accumulation of 5, 10 vm ethylene-tetrahydrofolate and results in a reduced incidence of DNA double strand breakage. The MS 2756 A-7G polymorphism also reduces the enzyme activity and results in the hypo methylation of DNA. Patients and Methods: To test this hypothesis, genetic polymorphisms in the folate metabolic pathway were investigated using the DNA from a case-control study on 31 patients having malignant lymphoma from the Oncology Outpatient Clinic of the New Children's Hospital, Cairo University and 30 controls who were actually normal children attending for vaccination to the same hospital. We found that there is a higher susceptibility with the MTHFR 677CC and MTHFR 1298 AA genotypes (OR=4.3, 95% CI 1.12-16). When those harbor at least one variant allele in either polymorphism of MTHFR they were defined as reference. For the MS 2756 AG genotype polymorphism there was also a higher susceptibility to developing malignant lymphoma (OR=2.6; 95% CI 1.16.4). Results suggest that folate and methionine metabolism may play an important role in the pathogenesis of malignant lymphoma. Further studies to confirm this association and detailed biologic mechanisms are now required

  17. Protection of DNA from radiation damage by the predominant folate in the circulation: 5-Methyltetrahydrofolate

    International Nuclear Information System (INIS)

    Bailey, Steven; Lenton, Kevin; Ayling, June

    2008-01-01

    Full text: Efforts to remediate the physiological harm of ionizing radiation have focused on only a few approaches, mostly aimed at limiting post exposure sequelae. Here we show a previously unrecognized radioprotectant property of two naturally occurring folates. 5-Methyl-6S-tetrahydrofolate (5-MTHF) and the related 5-formyl tetrahydrofolate (5-FTHF) block DNA cleavage during radiation exposure. They may also promote repair after exposure Supercoiled plasmid DNA, PBR 322, in phosphate buffer p H 7.0 was exposed to 6 MV X-rays. Electrophoresis on agarose gels revealed that most of the DNA had been converted to the relaxed or linearized forms by strand cleavage. Addition of 5-MTHF (∼10 -5 M) prevented the majority of this DNA damage. 5-FTHF was also effective at a slightly higher concentration. This protection against ionizing radiation was accompanied by a gradual loss of folate, presumably by reaction with hydroxyl radical, yielding the same compounds produced by air oxidation. The two folates were similarly effective in blocking the degradation of fluorescein by X-rays. Protection of DNA from UV initiated cleavage by photosensitizers was also demonstrated by sub-micromolar concentrations of 5-MTHF (FASEB J. 2007 21, 2101-7. This was found to be due to a different mechanism than in the case of ionizing radiation. During UV irradiation 5-MTHF effectively quenches the excited state of the photo sensitizer, and is also a diffusion limited scavenger of singlet oxygen. The high oral bioavailability, rapid cellular uptake, and extremely low toxicity profile of 5-MTHF suggest that this natural folate may be useful for preventing incipient damage to those who can anticipate radiation, e.g. first responders, when administered shortly before exposure. An increased folate status may also improve the rate of DNA repair subsequent to irradiation by stimulating the biosynthesis of nucleotide bases. (author)

  18. Folik Asit Takviyesi Turk Toplumunda Gebelerde Serum Folat Duzeyini Nasil Etkilemektedir?

    Directory of Open Access Journals (Sweden)

    Alev Ozer

    2016-07-01

    Full Text Available Aim: To determine the effect of the use of folic acid supplementation on serum folate levels in Turkish pregnant women. Material and Method: Clinical records of a total of 397 patients were retrospectively examined. The patients were recruited into 2 groups based on folic acid supplementation. Group 1 included 294 women who did not take any folic acid tablets before or during pregnancy and Group 2 consisted of 103 women who regularly took 400 mcg of folic acid daily, starting from the preconception period. Both groups were compared with respect to demographic and biochemical characteristics. Results: The patients in Group 1 and 2 had statistically similar pre-pregnancy and pregnancy hemoglobin, pre-pregnancy and pregnancy serum calcium, and pre-pregnancy and pregnancy serum folate concentrations (p=0.544, p=0.549, p=0.289, p=0.299, p=0.072, and p=0.061 respectively. No statistically significant difference was determined between pre-pregnancy and pregnancy folate concentrations in Group 1 (p=0.059. Pre-pregnancy and pregnancy folate concentrations were statistically similar in Group 2 (p=0.057. Both study groups were determined as statistically similar with respect to perinatal outcomes, including molar pregnancy, intrauterine demise, neural tube defects, ventricular septal defect, fetal growth restriction, preeclampsia, preterm birth, birth weight, neonatal intensive care unit admission, and 1st minute and 5th minute Apgar scores (p=0.760, p=0.576, p=0.382, p=0.553, p=0.452, p=0.940, p=0.683, p=0.855, p=0.710, p=0.910, and p=0.924 respectively. Discussion: Based on the findings of the present study, it may be considered that serum folate concentrations in pregnant women can be maintained by dietary intake alone of over 4.5 ng/ml.

  19. Identification, classification and expression pattern analysis of sugarcane cysteine proteinases

    Directory of Open Access Journals (Sweden)

    Gustavo Coelho Correa

    2001-12-01

    Full Text Available Cysteine proteases are peptidyl hydrolyses dependent on a cysteine residue at the active center. The physical and chemical properties of cysteine proteases have been extensively characterized, but their precise biological functions have not yet been completely understood, although it is known that they are involved in a number of events such as protein turnover, cancer, germination, programmed cell death and senescence. Protein sequences from different cysteine proteinases, classified as members of the E.C.3.4.22 sub-sub-class, were used to perform a T-BLAST-n search on the Brazilian Sugarcane Expressed Sequence Tags project (SUCEST data bank. Sequence homology was found with 76 cluster sequences that corresponded to possible cysteine proteinases. The alignments of these SUCEST clusters with the sequence of cysteine proteinases of known origins provided important information about the classification and possible function of these sugarcane enzymes. Inferences about the expression pattern of each gene were made by direct correlation with the SUCEST cDNA libraries from which each cluster was derived. Since no previous reports of sugarcane cysteine proteinases genes exists, this study represents a first step in the study of new biochemical, physiological and biotechnological aspects of sugarcane cysteine proteases.Proteinases cisteínicas são peptidil-hidrolases dependentes de um resíduo de cisteína em seu sítio ativo. As propriedades físico-químicas destas proteinases têm sido amplamente caracterizadas, entretanto suas funções biológicas ainda não foram completamente elucidadas. Elas estão envolvidas em um grande número de eventos, tais como: processamento e degradação protéica, câncer, germinação, morte celular programada e processos de senescência. Diferentes proteinases cisteínicas, classificadas pelo Comitê de Nomenclatura da União Internacional de Bioquímica e Biologia Molecular (IUBMB como pertencentes à sub

  20. Divergent unprotected peptide macrocyclisation by palladium-mediated cysteine arylation.

    Science.gov (United States)

    Rojas, Anthony J; Zhang, Chi; Vinogradova, Ekaterina V; Buchwald, Nathan H; Reilly, John; Pentelute, Bradley L; Buchwald, Stephen L

    2017-06-01

    Macrocyclic peptides are important therapeutic candidates due to their improved physicochemical properties in comparison to their linear counterparts. Here we detail a method for a divergent macrocyclisation of unprotected peptides by crosslinking two cysteine residues with bis-palladium organometallic reagents. These synthetic intermediates are prepared in a single step from commercially available aryl bis-halides. Two bioactive linear peptides with cysteine residues at i , i + 4 and i , i + 7 positions, respectively, were cyclised to introduce a diverse array of aryl and bi-aryl linkers. These two series of macrocyclic peptides displayed similar linker-dependent lipophilicity, phospholipid affinity, and unique volume of distributions. Additionally, one of the bioactive peptides showed target binding affinity that was predominantly affected by the length of the linker. Collectively, this divergent strategy allowed rapid and convenient access to various aryl linkers, enabling the systematic evaluation of the effect of appending unit on the medicinal properties of macrocyclic peptides.

  1. Carbon Nanotubes Facilitate Oxidation of Cysteine Residues of Proteins.

    Science.gov (United States)

    Hirano, Atsushi; Kameda, Tomoshi; Wada, Momoyo; Tanaka, Takeshi; Kataura, Hiromichi

    2017-10-19

    The adsorption of proteins onto nanoparticles such as carbon nanotubes (CNTs) governs the early stages of nanoparticle uptake into biological systems. Previous studies regarding these adsorption processes have primarily focused on the physical interactions between proteins and nanoparticles. In this study, using reduced lysozyme and intact human serum albumin in aqueous solutions, we demonstrated that CNTs interact chemically with proteins. The CNTs induce the oxidation of cysteine residues of the proteins, which is accounted for by charge transfer from the sulfhydryl groups of the cysteine residues to the CNTs. The redox reaction simultaneously suppresses the intermolecular association of proteins via disulfide bonds. These results suggest that CNTs can affect the folding and oxidation degree of proteins in biological systems such as blood and cytosol.

  2. Subcellular distribution of glutathione and cysteine in cyanobacteria

    OpenAIRE

    Zechmann, Bernd; Tomašić, Ana; Horvat, Lucija; Fulgosi, Hrvoje

    2010-01-01

    Glutathione plays numerous important functions in eukaryotic and prokaryotic cells. Whereas it can be found in virtually all eukaryotic cells, its production in prokaryotes is restricted to cyanobacteria and proteobacteria and a few strains of gram-positive bacteria. In bacteria, it is involved in the protection against reactive oxygen species (ROS), osmotic shock, acidic conditions, toxic chemicals, and heavy metals. Glutathione synthesis in bacteria takes place in two steps out of cysteine,...

  3. Allicin and derivates are cysteine protease inhibitors with antiparasitic activity.

    Science.gov (United States)

    Waag, Thilo; Gelhaus, Christoph; Rath, Jennifer; Stich, August; Leippe, Matthias; Schirmeister, Tanja

    2010-09-15

    Allicin and derivatives thereof inhibit the CAC1 cysteine proteases falcipain 2, rhodesain, cathepsin B and L in the low micromolar range. The structure-activity relationship revealed that only derivatives with primary carbon atom in vicinity to the thiosulfinate sulfur atom attacked by the active-site Cys residue are active against the target enzymes. Some compounds also show potent antiparasitic activity against Plasmodium falciparum and Trypanosoma brucei brucei. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  4. Effect of cysteine supplementation on in vitro maturation of bovine ...

    African Journals Online (AJOL)

    B Rahim, S Jalal, N Yosef ... Cumulus-oocyte complexes (COCs) from abattoir ovaries were matured in vitro in Hepes-TCM 199 supplemented with 0.2 mM sodium pyruvate, 1 μg/ml 17-β-estradiol, 10% fetal calf serum (FCS), 0.5 μg/ml bFSH and 0 (control) and 100 or 500 μM/ml of cysteine for 24 h. When COCs matured in ...

  5. Acid-Mediated Tumor Proteolysis: Contribution of Cysteine Cathepsins

    Directory of Open Access Journals (Sweden)

    Jennifer M Rothberg

    2013-10-01

    Full Text Available One of the noncellular microenvironmental factors that contribute to malignancy of solid tumors is acidic peritumoral pH. We have previously demonstrated that extracellular acidosis leads to localization of the cysteine pro-tease cathepsin B on the tumor cell membrane and its secretion. The objective of the present study was to determine if an acidic extracellular pH such as that observed in vivo (i.e., pHe 6.8 affects the activity of proteases, e.g., cathepsin B, that contribute to degradation of collagen IV by tumor cells when grown in biologically relevant three-dimensional (3D cultures. For these studies, we used 1 3D reconstituted basement membrane overlay cultures of human carcinomas, 2 live cell imaging assays to assess proteolysis, and 3 in vivo imaging of active tumor proteases. At pHe 6.8, there were increases in pericellular active cysteine cathepsins and in degradation of dye-quenched collagen IV, which was partially blocked by a cathepsin B inhibitor. Imaging probes for active cysteine cathepsins localized to tumors in vivo. The amount of bound probe decreased in tumors in bicarbonate-treated mice, a treatment previously shown to increase peritumoral pHe and reduce local invasion of the tumors. Our results are consistent with the acid-mediated invasion hypothesis and with a role for cathepsin B in promoting degradation of a basement membrane protein substrate, i.e., type IV collagen, in an acidic peritumoral environment.

  6. The effect of cysteine on electrodeposition of gold nanoparticle

    International Nuclear Information System (INIS)

    Dolati, A.; Imanieh, I.; Salehi, F.; Farahani, M.

    2011-01-01

    Highlights: → Cysteine was found as an appropriate additive for electrodeposition of gold nanoparticles. → The deposition mechanism of gold nanoparticle was determined as instantaneous nucleation. → Oxygen reduction on the gold nanoparticle surface was eight times greater than that on the conventional gold deposits. - Abstract: The most applications of gold nanoparticles are in the photo-electronical accessories and bio-chemical sensors. Chloride solution with cysteine additive was used as electrolyte in gold nanoparticles electrodeposition. The nucleation and growing mechanism were studied by electrochemical techniques such as cyclic voltammetry and chronoamperometry, in order to obtain a suitable nano structure. The deposition mechanism was determined as instantaneous nucleation and the dimension of particles was controlled in nanometric particle size range. Atomic Force Microscope was used to evaluate the effect of cysteine on the morphology and topography of gold nanoparticles. Finally the catalytic property of gold nanoparticle electrodeposited was studied in KOH solution, where oxygen reduction on the gold nanoparticle surface was eight times greater than that on the conventional gold deposits.

  7. Analysis of S-nitrosothiols via Copper Cysteine (2C) and Copper Cysteine - Carbon Monoxide (3C) Methods

    Science.gov (United States)

    Rogers, Stephen C.; Gibbons, Lindsey B.; Griffin, Sherraine; Doctor, Allan

    2012-01-01

    This chapter summarizes the principles of RSNO measurement in the gas phase, utilizing ozone-based chemiluminescence and the copper cysteine (2C) ± carbon monoxide (3C) reagent. Although an indirect method for quantifying RSNOs, this assay represents one of the most robust methodologies available. It exploits the NO• detection sensitivity of ozone based chemiluminscence, which is within the range required to detect physiological concentrations of RSNO metabolites. Additionally, the specificity of the copper cysteine (2C and 3C) reagent for RSNOs negates the need for sample pretreatment, thereby minimizing the likelihood of sample contamination (false positive results), NO species inter-conversion, or the loss of certain highly labile RSNO species. Herein, we outline the principles of this methodology, summarizing key issues, potential pitfalls and corresponding solutions. PMID:23116707

  8. The IRC7 gene encodes cysteine desulphydrase activity and confers on yeast the ability to grow on cysteine as a nitrogen source.

    Science.gov (United States)

    Santiago, Margarita; Gardner, Richard C

    2015-07-01

    Although cysteine desulphydrase activity has been purified and characterized from Saccharomyces cerevisiae, the gene encoding this activity in vivo has never been defined. We show that the full-length IRC7 gene, encoded by the YFR055W open reading frame, encodes a protein with cysteine desulphydrase activity. Irc7p purified to homogeneity is able to utilize l-cysteine as a substrate, producing pyruvate and hydrogen sulphide as products of the reaction. Purified Irc7p also utilized l-cystine and some other cysteine conjugates, but not l-cystathionine or l-methionine, as substrates. We further show that, in vivo, the IRC7 gene is both necessary and sufficient for yeast to grow on l-cysteine as a nitrogen source, and that overexpression of the gene results in increased H2 S production. Strains overexpressing IRC7 are also hypersensitive to a toxic analogue, S-ethyl-l-cysteine. While IRC7 has been identified as playing a critical role in converting cysteine conjugates to volatile thiols that are important in wine aroma, its biological role in yeast cells is likely to involve regulation of cysteine and redox homeostasis. Copyright © 2015 John Wiley & Sons, Ltd.

  9. Structure and mechanism leading to formation of the cysteine sulfinate product complex of a biomimetic cysteine dioxygenase model.

    Science.gov (United States)

    Sallmann, Madleen; Kumar, Suresh; Chernev, Petko; Nehrkorn, Joscha; Schnegg, Alexander; Kumar, Devesh; Dau, Holger; Limberg, Christian; de Visser, Sam P

    2015-05-11

    Cysteine dioxygenase is a unique nonheme iron enzyme that is involved in the metabolism of cysteine in the body. It contains an iron active site with an unusual 3-His ligation to the protein, which contrasts with the structural features of common nonheme iron dioxygenases. Recently, some of us reported a truly biomimetic model for this enzyme, namely a trispyrazolylborato iron(II) cysteinato complex, which not only has a structure very similar to the enzyme-substrate complex but also represents a functional model: Treatment of the model with dioxygen leads to cysteine dioxygenation, as shown by isolating the cysteine part of the product in the course of the work-up. However, little is known on the conversion mechanism and, so far, not even the structure of the actual product complex had been characterised, which is also unknown in case of the enzyme. In a multidisciplinary approach including density functional theory calculations and X-ray absorption spectroscopy, we have now determined the structure of the actual sulfinato complex for the first time. The Cys-SO2 (-) functional group was found to be bound in an η(2) -O,O-coordination mode, which, based on the excellent resemblance between model and enzyme, also provides the first support for a corresponding binding mode within the enzymatic product complex. Indeed, this is again confirmed by theory, which had predicted a η(2) -O,O-binding mode for synthetic as well as the natural enzyme. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Identification of novel malarial cysteine protease inhibitors using structure-based virtual screening of a focused cysteine protease inhibitor library.

    Science.gov (United States)

    Shah, Falgun; Mukherjee, Prasenjit; Gut, Jiri; Legac, Jennifer; Rosenthal, Philip J; Tekwani, Babu L; Avery, Mitchell A

    2011-04-25

    Malaria, in particular that caused by Plasmodium falciparum , is prevalent across the tropics, and its medicinal control is limited by widespread drug resistance. Cysteine proteases of P. falciparum , falcipain-2 (FP-2) and falcipain-3 (FP-3), are major hemoglobinases, validated as potential antimalarial drug targets. Structure-based virtual screening of a focused cysteine protease inhibitor library built with soft rather than hard electrophiles was performed against an X-ray crystal structure of FP-2 using the Glide docking program. An enrichment study was performed to select a suitable scoring function and to retrieve potential candidates against FP-2 from a large chemical database. Biological evaluation of 50 selected compounds identified 21 diverse nonpeptidic inhibitors of FP-2 with a hit rate of 42%. Atomic Fukui indices were used to predict the most electrophilic center and its electrophilicity in the identified hits. Comparison of predicted electrophilicity of electrophiles in identified hits with those in known irreversible inhibitors suggested the soft-nature of electrophiles in the selected target compounds. The present study highlights the importance of focused libraries and enrichment studies in structure-based virtual screening. In addition, few compounds were screened against homologous human cysteine proteases for selectivity analysis. Further evaluation of structure-activity relationships around these nonpeptidic scaffolds could help in the development of selective leads for antimalarial chemotherapy.

  11. Results with commercial radioassay kits compared with microbiological assay of folate in serum and whole-blood

    International Nuclear Information System (INIS)

    McGown, E.L.; Lewis, C.M.; Dong, M.H.; Sauberlich, H.E.

    1978-01-01

    Results with three commercial folate radioassay kits [Bio-Rad, New England Nuclear (NEN), and RIA Products] were compared with those by microbiological assay for more than 200 samples of human serum and whole blood. All but one kit (NEN) compared favorably with the microbiological assay for serum samples, although there were notable diagnostic discrepancies. Two kits (NEN and Bio-Rad) were tested on whole-blood samples; both yielded values significantly higher than those by microbiological assay. The frequency distributions of erythrocyte folate data differed strikingly between the two kits; the NEN method yielded a much narrower range of normal values than did either the Bio-Rad or the microbiological assay. Radioassay kits appear to be suitable diagnostic agents for serum folate, if the behavior of a particular kit is investigated thoroughly before its routine use. However, the diagnostic value of radioassays of erythrocyte folate needs to be validated

  12. The epigenetic effects of a high prenatal folate intake in male mouse fetuses exposed in utero to arsenic

    International Nuclear Information System (INIS)

    Tsang, Verne; Fry, Rebecca C.; Niculescu, Mihai D.; Rager, Julia E.; Saunders, Jesse; Paul, David S.; Zeisel, Steven H.; Waalkes, Michael P.; Stýblo, Miroslav; Drobná, Zuzana

    2012-01-01

    Inorganic arsenic (iAs) is a complete transplacental carcinogen in mice. Previous studies have demonstrated that in utero exposure to iAs promotes cancer in adult mouse offspring, possibly acting through epigenetic mechanisms. Humans and rodents enzymatically convert iAs to its methylated metabolites. This reaction requires S-adenosylmethionine (SAM) as methyl group donor. SAM is also required for DNA methylation. Supplementation with folate, a major dietary source of methyl groups for SAM synthesis, has been shown to modify iAs metabolism and the adverse effects of iAs exposure. However, effects of gestational folate supplementation on iAs metabolism and fetal DNA methylation have never been thoroughly examined. In the present study, pregnant CD1 mice were fed control (i.e. normal folate, or 2.2 mg/kg) or high folate diet (11 mg/kg) from gestational day (GD) 5 to 18 and drank water with 0 or 85 ppm of As (as arsenite) from GD8 to 18. The exposure to iAs significantly decreased body weight of GD18 fetuses and increased both SAM and S-adenosylhomocysteine (SAH) concentrations in fetal livers. High folate intake lowered the burden of total arsenic in maternal livers but did not prevent the effects of iAs exposure on fetal weight or hepatic SAM and SAH concentrations. In fact, combined folate-iAs exposure caused further significant body weight reduction. Notably, iAs exposure alone had little effect on DNA methylation in fetal livers. In contrast, the combined folate-iAs exposure changed the CpG island methylation in 2,931 genes, including genes known to be imprinted. Most of these genes were associated with neurodevelopment, cancer, cell cycle, and signaling networks. The canonical Wnt-signaling pathway, which regulates fetal development, was among the most affected biological pathways. Taken together, our results suggest that a combined in utero exposure to iAs and a high folate intake may adversely influence DNA methylation profiles and weight of fetuses

  13. The epigenetic effects of a high prenatal folate intake in male mouse fetuses exposed in utero to arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Tsang, Verne [Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States); Fry, Rebecca C. [Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States); Niculescu, Mihai D. [UNC Nutrition Research Institute, Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States); Rager, Julia E. [Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States); Saunders, Jesse; Paul, David S. [Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States); Zeisel, Steven H. [Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States); UNC Nutrition Research Institute, Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States); Waalkes, Michael P. [NIEHS, Research Triangle Park, NC 27709 (United States); Stýblo, Miroslav [Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States); Drobná, Zuzana, E-mail: drobnazu@med.unc.edu [Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States)

    2012-11-01

    Inorganic arsenic (iAs) is a complete transplacental carcinogen in mice. Previous studies have demonstrated that in utero exposure to iAs promotes cancer in adult mouse offspring, possibly acting through epigenetic mechanisms. Humans and rodents enzymatically convert iAs to its methylated metabolites. This reaction requires S-adenosylmethionine (SAM) as methyl group donor. SAM is also required for DNA methylation. Supplementation with folate, a major dietary source of methyl groups for SAM synthesis, has been shown to modify iAs metabolism and the adverse effects of iAs exposure. However, effects of gestational folate supplementation on iAs metabolism and fetal DNA methylation have never been thoroughly examined. In the present study, pregnant CD1 mice were fed control (i.e. normal folate, or 2.2 mg/kg) or high folate diet (11 mg/kg) from gestational day (GD) 5 to 18 and drank water with 0 or 85 ppm of As (as arsenite) from GD8 to 18. The exposure to iAs significantly decreased body weight of GD18 fetuses and increased both SAM and S-adenosylhomocysteine (SAH) concentrations in fetal livers. High folate intake lowered the burden of total arsenic in maternal livers but did not prevent the effects of iAs exposure on fetal weight or hepatic SAM and SAH concentrations. In fact, combined folate-iAs exposure caused further significant body weight reduction. Notably, iAs exposure alone had little effect on DNA methylation in fetal livers. In contrast, the combined folate-iAs exposure changed the CpG island methylation in 2,931 genes, including genes known to be imprinted. Most of these genes were associated with neurodevelopment, cancer, cell cycle, and signaling networks. The canonical Wnt-signaling pathway, which regulates fetal development, was among the most affected biological pathways. Taken together, our results suggest that a combined in utero exposure to iAs and a high folate intake may adversely influence DNA methylation profiles and weight of fetuses

  14. Synthesis and In Vitro and In Vivo Evaluation of Iodine-131-Labeled Folates: Potential Molecular Diagnostic and Therapeutic Radiopharmaceuticals

    International Nuclear Information System (INIS)

    Al Jammaz, I.

    2009-01-01

    Molecular targeting imaging has a great potential to be able to image molecular changes that are currently defined as predisease states which facilitate earlier detection of cancer and consequently, the greatest chance of cure. Advancement of scintigraphic imaging and radiotherapy is highly determined by development of more specific radiotracers. The Membrane-associated-folic acid receptor is a glycosylphospstidylinositol protein that overexpressed in approximately 100% of serious ovarian adenocarcinomas and various epithelial cancers including cervical, colorectal and renal cancers. Meanwhile, this receptor is highly restricted in most normal tissues which make these tumors as an excellent candidates for molecular targeting imaging and therapy through the folate receptor system. As part of our on-going research effort to develop prosthetic precursors for radiohalogenation of bioactive molecules, we have previously reported the synthesis and biological characterization of [ 18 F]- fluorobenzene and pyridine carbohydrazide-folate conjugates ([ 18 F]-SFB and [ 18 F]-SFP-folates). We here report the synthesis and biological characterization of [ 131 I]-iodobenzenecarbohydrazide-folate conjugate ([ 131 I]-SIB-folate) as a potential therapeutic radiopharmaceutical. The synthetic approaches for preparation of [ 131 I]iodobenzene carbohydrazide-folates ([ 131 I]-SIB-folate) entailed sequence of reactions. Hydrazide-folate was reacted with N-succinimidyl-m-[131I]-iodobenzoate-carboxylate ([ 131 I]-SIB) to give [ 131 I]-SIB-folate conjugate. Radiochemical yield was greater than 80% and synthesis times were ranging between 40-45 min. Radiochemical purity was also greater than 97% without HPLC purification. These synthetic approaches hold considerable promise as rapid and simple method for the radiohalogenation of folate in high radiochemical yield in short time. In vitro tests on KB cell line has shown that significant amount of the radioconjugate associated with cell

  15. A comparison of folate status in women of child-bearing age in Korea and in the United States

    Directory of Open Access Journals (Sweden)

    Hyun T

    2012-07-01

    Full Text Available Taisun Hyun,1 Suguna Badiga,2 Han Byul Jang,1 Young-Hee Han,1 Chandrika J Piyathilake21Department of Food and Nutrition, Chungbuk National University, Cheongju, Korea; 2Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL, USABackground: Even though several studies have demonstrated that periconceptional supplementation with folic acid (FA reduces the occurrence of neural tube defects, FA fortification has been a topic of intense debate due to the possible adverse effects of higher folate status on several health conditions. Several countries, including Korea, have been indecisive as to whether fortification is warranted or not. It is therefore helpful for these countries to compare folate concentrations in their populations with populations exposed to mandatory FA fortification.Purpose: To evaluate the differences in the distribution of circulating concentrations of folate in Korea and the United States (US at different time points.Methods: The Korean study populations consisted of women of child-bearing age recruited in 1999 and in 2009. The US study populations consisted of women of child-bearing age recruited in the post FA fortification era (2005 and 2009. Plasma and red blood cell (RBC folate concentrations were measured using the Lactobacillus casei microbiological assay.Results: The percentage of US women with neural tube defect-protective levels of RBC folate was significantly higher compared to Korean women in 1999 and 2009. However, in 2009, when FA supplements became readily available for Koreans, 50% of Korean women in the study achieved the neural tube defect-protective level of RBC folate; 11% of them demonstrating supraphysiologic concentrations of plasma folate. Even though FA fortification in the US resulted in more than 80of women achieving >400 ng/mL of RBC folate by 2009, nearly 50% also demonstrated having supraphysiologic concentrations of plasma folate, which prompted some researchers to

  16. A novel potentiometric biosensor for selective L-cysteine determination using L-cysteine-desulfhydrase producing Trichosporon jirovecii yeast cells coupled with sulfide electrode

    International Nuclear Information System (INIS)

    Hassan, Saad S.M.; El-Baz, Ashraf F.; Abd-Rabboh, Hisham S.M.

    2007-01-01

    Trichosporon jirovecii yeast cells are used for the first time as a source of L-cysteine desulfhydrase enzyme (EC 4.4.1.1) and incorporated in a biosensor for determining L-cysteine. The cells are grown under cadmium stress conditions to increase the expression level of the enzyme. The intact cells are immobilized on the membrane of a solid-state Ag 2 S electrode to provide a simple L-cysteine responsive biosensor. Upon immersion of the sensor in L-cysteine containing solutions, L-cysteine undergoes enzymatic hydrolysis into pyruvate, ammonia and sulfide ion. The rate of sulfide ion formation is potentiometrically measured as a function of L-cysteine concentration. Under optimized conditions (phosphate buffer pH 7, temperature 37 ± 1 deg. C and actual weight of immobilized yeast cells 100 mg), a linear relationship between L-cysteine concentration and the initial rate of sulfide liberation (dE/dt) is obtained. The sensor response covers the concentration range of 0.2-150 mg L -1 (1.7-1250 μmol L -1 ) L-cysteine. Validation of the assay method according to the quality control/quality assurance standards (precision, accuracy, between-day variability, within-day reproducibility, range of measurements and lower limit of detection) reveals remarkable performance characteristics of the proposed biosensor. The sensor is satisfactorily utilized for determination of L-cysteine in some pharmaceutical formulations. The lower limit of detection is ∼1 μmol L -1 and the accuracy and precision of the method are 97.5% and ±1.1%, respectively. Structurally similar sulfur containing compounds such as glutathione, cystine, methionine, and D-cysteine do no interfere

  17. Maternal folic acid supplementation and dietary folate intake and congenital heart defects.

    Directory of Open Access Journals (Sweden)

    Baohong Mao

    Full Text Available It has been reported that folic acid supplementation before and/or during pregnancy could reduce the risk of congenital heart defects (CHDs. However, the results from limited epidemiologic studies have been inconclusive. We investigated the associations between maternal folic acid supplementation, dietary folate intake, and the risk of CHDs.A birth cohort study was conducted in 2010-2012 at the Gansu Provincial Maternity & Child Care Hospital in Lanzhou, China. After exclusion of stillbirths and multiple births, a total of 94 births were identified with congenital heart defects, and 9,993 births without any birth defects. Unconditional logistic regression was used to estimate the associations.Compared to non-users, folic acid supplement users before pregnancy had a reduced risk of overall CHDs (OR: 0.42, 95% CI: 0.21-0.86, Ptrend = 0.025 after adjusted for potential confounders. A protective effect was observed for certain subtypes of CHDs (OR: 0.37, 95% CI: 0.16-0.85 for malformation of great arteries; 0.26, 0.10-0.68 for malformation of cardiac septa; 0.34, 0.13-0.93 for Atrial septal defect. A similar protective effect was also seen for multiple CHDs (OR: 0.49, 95% CI: 0.26-0.93, Ptrend = 0.004. Compared with the middle quartiles of dietary folate intake, lower dietary folate intake (<149.88 μg/day during pregnancy were associated with increased risk of overall CHDs (OR: 1.63, 95% CI: 1.01-2.62 and patent ductus arteriosus (OR: 1.85, 95% CI: 1.03-3.32. Women who were non-user folic acid supplement and lower dietary folate intake have almost 2-fold increased CHDs risk in their offspring.Our study suggested that folic acid supplementation before pregnancy was associated with a reduced risk of CHDs, lower dietary folate intake during pregnancy was associated with increased risk. The observed associations varied by CHD subtypes. A synergistic effect of dietary folate intake and folic acid supplementation was also observed.

  18. Folate (vitamin B9) and vitamin B12 and their function in the maintenance of nuclear and mitochondrial genome integrity

    International Nuclear Information System (INIS)

    Fenech, Michael

    2012-01-01

    Folate plays a critical role in the prevention of uracil incorporation into DNA and hypomethylation of DNA. This activity is compromised when vitamin B12 concentration is low because methionine synthase activity is reduced, lowering the concentration of S-adenosyl methionine (SAM) which in turn may diminish DNA methylation and cause folate to become unavailable for the conversion of dUMP to dTMP. The most plausible explanation for the chromosome-breaking effect of low folate is excessive uracil misincorporation into DNA, a mutagenic lesion that leads to strand breaks in DNA during repair. Both in vitro and in vivo studies with human cells clearly show that folate deficiency causes expression of chromosomal fragile sites, chromosome breaks, excessive uracil in DNA, micronucleus formation, DNA hypomethylation and mitochondrial DNA deletions. In vivo studies show that folate and/or vitamin B12 deficiency and elevated plasma homocysteine (a metabolic indicator of folate deficiency) are significantly correlated with increased micronucleus formation and reduced telomere length respectively. In vitro experiments indicate that genomic instability in human cells is minimised when folic acid concentration in culture medium is greater than 100 nmol/L. Intervention studies in humans show (a) that DNA hypomethylation, chromosome breaks, uracil incorporation and micronucleus formation are minimised when red cell folate concentration is greater than 700 nmol/L and (b) micronucleus formation is minimised when plasma concentration of vitamin B12 is greater than 300 pmol/L and plasma homocysteine is less than 7.5 μmol/L. These concentrations are achievable at intake levels at or above current recommended dietary intakes of folate (i.e. >400 μg/day) and vitamin B12 (i.e. >2 μg/day) depending on an individual's capacity to absorb and metabolise these vitamins which may vary due to genetic and epigenetic differences.

  19. Genetic and epigenetic alterations of the reduced folate carrier in untreated diffuse large B-cell lymphoma

    DEFF Research Database (Denmark)

    Kastrup, I.B.; Worm, J.; Ralfkiaer, E.

    2008-01-01

    The reduced folate carrier (RFC) is a transmembrane protein that mediates cellular uptake of reduced folates and antifolate drugs, including methotrexate (MTX). Acquired alterations of the RFC gene have been associated with resistance to MTX in cancer cell lines and primary osteosarcomas. Here, w...... with adverse outcome. In DLBCL, genetic and epigenetic alterations of RFC were detected at diagnosis in the absence of a selective MTX pressure, suggesting that these alterations may possibly contribute to the development of lymphoma Udgivelsesdato: 2008/1...

  20. Folate (vitamin B9) and vitamin B12 and their function in the maintenance of nuclear and mitochondrial genome integrity

    Energy Technology Data Exchange (ETDEWEB)

    Fenech, Michael, E-mail: michael.fenech@csiro.au [CSIRO Food and Nutritional Sciences, PO Box 10041 Adelaide BC, SA 5000 (Australia)

    2012-05-01

    Folate plays a critical role in the prevention of uracil incorporation into DNA and hypomethylation of DNA. This activity is compromised when vitamin B12 concentration is low because methionine synthase activity is reduced, lowering the concentration of S-adenosyl methionine (SAM) which in turn may diminish DNA methylation and cause folate to become unavailable for the conversion of dUMP to dTMP. The most plausible explanation for the chromosome-breaking effect of low folate is excessive uracil misincorporation into DNA, a mutagenic lesion that leads to strand breaks in DNA during repair. Both in vitro and in vivo studies with human cells clearly show that folate deficiency causes expression of chromosomal fragile sites, chromosome breaks, excessive uracil in DNA, micronucleus formation, DNA hypomethylation and mitochondrial DNA deletions. In vivo studies show that folate and/or vitamin B12 deficiency and elevated plasma homocysteine (a metabolic indicator of folate deficiency) are significantly correlated with increased micronucleus formation and reduced telomere length respectively. In vitro experiments indicate that genomic instability in human cells is minimised when folic acid concentration in culture medium is greater than 100 nmol/L. Intervention studies in humans show (a) that DNA hypomethylation, chromosome breaks, uracil incorporation and micronucleus formation are minimised when red cell folate concentration is greater than 700 nmol/L and (b) micronucleus formation is minimised when plasma concentration of vitamin B12 is greater than 300 pmol/L and plasma homocysteine is less than 7.5 {mu}mol/L. These concentrations are achievable at intake levels at or above current recommended dietary intakes of folate (i.e. >400 {mu}g/day) and vitamin B12 (i.e. >2 {mu}g/day) depending on an individual's capacity to absorb and metabolise these vitamins which may vary due to genetic and epigenetic differences.

  1. The MTHFR 677TT genotype and folate intake interact to lower global leukocyte DNA methylation in young Mexican American women.

    OpenAIRE

    Axume, Juan; Smith, Steven S; Pogribny, Igor P; Moriarty, David J.; Caudill., Marie A.

    2007-01-01

    DNA methylation is an epigenetic feature that is associated with X chromosome inactivation, genomic imprinting, transcriptional silencing of genes and genomic stability. Folate provides a labile source of methyl groups which may be used for cellular methylation reactions including DNA methylation. The methylenetetrahydrofolate reductase (MTHFR) 677C→T variant is an important determinant of folate nutriture and may influence DNA methylation. This study sought to assess the influence of the MTH...

  2. Amnionless function is required for cubilin brush-border expression and intrinsic factor-cobalamin (vitamin B12) absorption in vivo

    Science.gov (United States)

    He, Qianchuan; Madsen, Mette; Kilkenney, Adam; Gregory, Brittany; Christensen, Erik I.; Vorum, Henrik; Højrup, Peter; Schäffer, Alejandro A.; Kirkness, Ewen F.; Tanner, Stephan M.; de la Chapelle, Albert; Giger, Urs; Moestrup, Søren K.; Fyfe, John C.

    2005-01-01

    Amnionless (AMN) and cubilin gene products appear to be essential functional subunits of an endocytic receptor called cubam. Mutation of either gene causes autosomal recessive Imerslund-Gräsbeck syndrome (I-GS, OMIM no. 261100) in humans, a disorder characterized by selective intestinal malabsorption of cobalamin (vitamin B12) and urinary loss of several specific low-molecular-weight proteins. Vital insight into the molecular pathology of I-GS has been obtained from studies of dogs with a similar syndrome. In this work, we show that I-GS segregates in a large canine kindred due to an in-frame deletion of 33 nucleotides in exon 10 of AMN. In a second, unrelated I-GS kindred, affected dogs exhibit a homozygous substitution in the AMN translation initiation codon. Studies in vivo demonstrated that both mutations abrogate AMN expression and block cubilin processing and targeting to the apical membrane. The essential features of AMN dysfunction observed in vivo are recapitulated in a heterologous cell-transfection system, thus validating the system for analysis of AMN-cubilin interactions. Characterization of canine AMN mutations that cause I-GS establishes the canine model as an ortholog of the human disorder well suited to studies of AMN function and coevolution with cubilin. (Blood. 2005;106:1447-1453) PMID:15845892

  3. Influence of folic acid, pyridoxal phosphate and cobalamin on plasma homocyst(e)ine levels and the susceptibility of low-density lipoprotein to ex-vivo oxidation.

    Science.gov (United States)

    Weiss, N; Feussner, A; Hailer, S; Spengel, F A; Keller, C; Wolfram, G

    1999-10-15

    Mild hyperhomocyst(e)inaemia is a risk factor for atherosclerotic vascular disease. In-vitro studies have shown that autooxidation of homocyst(e)ine is accompanied by the generation of oxygen radicals. This may lead to oxidative modification of low-density lipoproteins (LDL) and promote atherosclerotic vascular lesions. In male patients with peripheral arterial occlusive disease we determined fasting and post methionine load homocyst(e)ine levels by high performance liquid chromatography and the susceptibility of their LDL particles to ex-vivo oxidation by continously measuring the conjugated diene production induced by incubation with copper ions. Oxidation resistance (expressed as lag time), maximal oxidation rate, and extent of oxidation (expressed of total diene production) of LDL from patients with normal or mildly elevated homocyst(e)ine levels did not differ significantly. Folic acid, pyridoxal phosphate and cobalamin supplementation significantly decreased plasma homocyst(e)ine levels in hyperhomocyst(e)inaemic patients. This went along with a significant decrease in the extent of LDL oxidation and additionally increased HDL-cholesterol levels. The clinical relevance of these findings for the long-term course of atherosclerotic vascular disorders has to be determined by intervention studies.

  4. Blood folate concentrations among women of childbearing age by race/ethnicity and acculturation, NHANES 2001-2010.

    Science.gov (United States)

    Marchetta, Claire M; Hamner, Heather C

    2016-01-01

    Hispanic women have higher rates of neural tube defects and report lower total folic acid intakes than non-Hispanic white (NHW) women. Total folic acid intake, which is associated with neural tube defect risk reduction, has been found to vary by acculturation factors (i.e. language preference, country of origin, or time spent in the United States) among Hispanic women. It is unknown whether this same association is present for blood folate status. The objective of this research was to assess the differences in serum and red blood cell (RBC) folate concentrations between NHW women and Mexican American (MA) women and among MA women by acculturation factors. Cross-sectional data from the 2001-2010 National Health and Nutrition Examination Survey (NHANES) were used to investigate how blood folate concentrations differ among NHW or MA women of childbearing age. The impact of folic acid supplement use on blood folate concentrations was also examined. MA women with lower acculturation factors had lower serum and RBC folate concentrations compared with NHW women and to their more acculturated MA counterparts. Consuming a folic acid supplement can minimize these disparities, but MA women, especially lower acculturated MA women, were less likely to report using supplements. Public health efforts to increase blood folate concentrations among MA women should consider acculturation factors when identifying appropriate interventions. © 2014 John Wiley & Sons Ltd.

  5. Vitamin B12 and folate during pregnancy and offspring motor, mental and social development at 2 years of age.

    Science.gov (United States)

    Bhate, V K; Joshi, S M; Ladkat, R S; Deshmukh, U S; Lubree, H G; Katre, P A; Bhat, D S; Rush, E C; Yajnik, C S

    2012-04-01

    Insufficiency of vitamin B12 (B12) and folate during pregnancy can result in low concentrations in the fetus and have adverse effects on brain development. We investigated the relationship between maternal B12 and folate nutrition during pregnancy and offspring motor, mental and social development at two years of age (2 y). Mothers (n = 123) and their offspring (62 girls, 61 boys) from rural and middle-class urban communities in and around Pune city were followed through pregnancy up to 2 y. Maternal B12 and folate concentrations were measured at 28 and 34 weeks of gestation. At 2 y, the Developmental Assessment Scale for Indian Infants was used to determine motor and mental developmental quotients and the Vineland Social Maturity Scale for the social developmental quotient. Overall, 62% of the mothers had low B12 levels (development was associated with maternal folate at 28 and 34 weeks of gestation. Mental and social development quotients were associated positively with head circumference and negatively with birth weight. In addition, pregnancy B12 and folate were positively associated with mental and social development quotients. Maternal B12 and folate during intrauterine life may favorably influence brain development and function. Pregnancy provides a window of opportunity to enhance fetal psychomotor (motor and mental) development.

  6. Enhancement of thioredoxin/glutaredoxin-mediated L-cysteine synthesis from S-sulfocysteine increases L-cysteine production in Escherichia coli

    Science.gov (United States)

    2012-01-01

    Background Escherichia coli has two L-cysteine biosynthetic pathways; one is synthesized from O-acetyl L-serine (OAS) and sulfate by L-cysteine synthase (CysK), and another is produced via S-sulfocysteine (SSC) from OAS and thiosulfate by SSC synthase (CysM). SSC is converted into L-cysteine and sulfite by an uncharacterized reaction. As thioredoxins (Trx1 and Trx2) and glutaredoxins (Grx1, Grx2, Grx3, Grx4, and NrdH) are known as reductases of peptidyl disulfides, overexpression of such reductases might be a good way for improving L-cysteine production to accelerate the reduction of SSC in E. coli. Results Because the redox enzymes can reduce the disulfide that forms on proteins, we first tested whether these enzymes catalyze the reduction of SSC to L-cysteine. All His-tagged recombinant enzymes, except for Grx4, efficiently convert SSC into L-cysteine in vitro. Overexpression of Grx1 and NrdH enhanced a 15-40% increase in the E. coliL-cysteine production. On the other hand, disruption of the cysM gene cancelled the effect caused by the overexpression of Grx1 and NrdH, suggesting that its improvement was due to the efficient reduction of SSC under the fermentative conditions. Moreover, L-cysteine production in knockout mutants of the sulfite reductase genes (ΔcysI and ΔcysJ) and the L-cysteine synthase gene (ΔcysK) each decreased to about 50% of that in the wild-type strain. Interestingly, there was no significant difference in L-cysteine production between wild-type strain and gene deletion mutant of the upstream pathway of sulfite (ΔcysC or ΔcysH). These results indicate that sulfite generated from the SSC reduction is available as the sulfur source to produce additional L-cysteine molecule. It was finally found that in the E. coliL-cysteine producer that co-overexpress glutaredoxin (NrdH), sulfite reductase (CysI), and L-cysteine synthase (CysK), there was the highest amount of L-cysteine produced per cell. Conclusions In this work, we showed that Grx1 and

  7. Activated human CD4 T cells express transporters for both cysteine and cystine

    DEFF Research Database (Denmark)

    Levring, Trine Bøegh; Hansen, Ann Kathrine; Nielsen, Bodil Lisbeth

    2012-01-01

    Because naïve T cells are unable to import cystine due to the absence of cystine transporters, it has been suggested that T cell activation is dependent on cysteine generated by antigen presenting cells. The aim of this study was to determine at which phases during T cell activation exogenous...... cystine/cysteine is required and how T cells meet this requirement. We found that early activation of T cells is independent of exogenous cystine/cysteine, whereas T cell proliferation is strictly dependent of uptake of exogenous cystine/cysteine. Naïve T cells express no or very low levels of both...... cystine and cysteine transporters. However, we found that these transporters become strongly up-regulated during T cell activation and provide activated T cells with the required amount of cystine/cysteine needed for T cell proliferation. Thus, T cells are equipped with mechanisms that allow T cell...

  8. Folic acid derivatives for PET imaging and therapy addressing folate receptor positive tumors

    Energy Technology Data Exchange (ETDEWEB)

    Schieferstein, Hanno

    2013-07-01

    Folic acid, also known as vitamin B9, is the oxidized form of 5,6,7,8-tetrahydrofolate, which serves as methyl- or methylene donor (C1-building blocks) during DNA synthesis. Under physiological conditions the required amount of 5,6,7,8-tetrahydrofolate for survival of the cell is accomplished through the reduced folate carrier (RFC). In contrast, the supply of 5,6,7,8-tetrahydrofolate is insufficient under pathophysiological conditions of tumors due to an increased proliferation rate. Consequently, many tumor cells exhibit an (over)expression of the folate receptor. This phenomenon has been applied to diagnostics (PET, SPECT, MR) to image FR-positive tumors and on the other hand to treat malignancies related to a FR (over)expression. Based on this concept, a new {sup 18}F-labeled folate for PET imaging has been developed and was evaluated in vivo using tumor-bearing mice. The incorporation of oligoethylene spacers into the molecular structure led to a significant enhancement of the pharmacokinetics in comparison to previously developed {sup 18}F-folates. The liver uptake could be reduced by one sixth by remaining a tumor uptake of 3%ID/g leading to better contrast ratios. Encouraged by these results, a clickable {sup 18}F-labeled serine-based prosthetic group has been synthesized, again with the idea to improve the metabolic and pharmacokinetic profile of hydrophilic radiotracers. Therefore, an alkyne-carrying azido-functionalized serine derivative for coupling to biomolecules was synthesized and a chlorine leaving group for {sup 18}F-labeling, which could be accomplished using a microwave-assisted synthesis, a [K is contained in 2.2.2]{sup +}/carbonate system in DMSO. Radiochemical yields of 77±6% could be achieved. The promising results obtained from the FR-targeting concept in the diagnostic field have been transferred to the boron neutron capture therapy. Therefore, a folate derivative was coupled to different boron clusters and cell uptake studies were

  9. Rapid HPLC-MS method for the simultaneous determination of tea catechins and folates.

    Science.gov (United States)

    Araya-Farias, Monica; Gaudreau, Alain; Rozoy, Elodie; Bazinet, Laurent

    2014-05-14

    An effective and rapid HPLC-MS method for the simultaneous separation of the eight most abundant tea catechins, gallic acid, and caffeine was developed. These compounds were rapidly separated within 9 min by a linear gradient elution using a Zorbax SB-C18 packed with sub 2 μm particles. This methodology did not require preparative and semipreparative HPLC steps. In fact, diluted tea samples can be easily analyzed using HPLC-MS as described in this study. The use of mass spectrometry detection for quantification of catechins ensured a higher specificity of the method. The percent relative standard deviation was generally lower than 4 and 7% for most of the compounds tested in tea drinks and tea extracts, respectively. Furthermore, the method provided excellent resolution for folate determination alone or in combination with catechins. To date, no HPLC method able to discriminate catechins and folates in a quick analysis has been reported in the literature.

  10. alpha isoforms of soluble and membrane-linked folate-binding protein in human blood

    DEFF Research Database (Denmark)

    Hoier-Madsen, M.; Holm, J.; Hansen, S.I.

    2008-01-01

    supported the hypothesis that serum FBP (29 kDa) mainly originates from neutrophils. The presence of FBP/FR alpha isoforms were established for the first time in human blood using antibodies specifically directed against human milk FBP alpha. The alpha isoforms identified on erythrocyte membranes......, and in granulocytes and serum, only constituted an almost undetectable fraction of the functional FBP The FBP alpha in neutrophil granulocytes was identified as a cytoplasmic component by indirect immunofluorescence. Gel filtration of serum revealed a peak of FBP alpha (>120 kDa), which could represent receptor...... fragments from decomposed erythrocytes and granulocytes. The soluble FBPs may exert bacteriostatic effects and protect folates in plasma from biological degradation, whereas FRs on the surface of blood cells could be involved in intracellular folate uptake or serve as signal proteins. The latter receptors...

  11. Identification and measurement of a folate-binding protein in human serum by radioimmunoassay

    International Nuclear Information System (INIS)

    Da Costa, M.; Rothenberg, S.P.; Fischer, C.; Rosenberg, Z.

    1978-01-01

    Antiserum raised in rabbits against the FBP obtained from CML cells, and the purified binder labeled with 125 I, have been used for an RIA which can measure an immunologically similar protein in human serum. The concentration of the binding protein in normal serums ranged from 1.2 to 9.3 ng/ml, with a mean +- S.E.M. of 3.8 +- 0.4 ng/ml. Elevated values of the binder protein were measured in the serums from patients with folate deficiency, vitamin B 12 deficiency, liver disease, uremia, myeloproliferative diseases, chronic lymphocytic leukemia, and various types of cancer and in the serum from pregnant women. The concentration of the binder protein and the capacity of the serum to specifically bind isotopically labeled PGA correlated poorly, indicating that the binding protein concentration and degree of saturation by endogenous serum folate vary independently in many instances

  12. Cellular uptake of folate-conjugated lipophilic superparamagnetic iron oxide nanoparticles

    International Nuclear Information System (INIS)

    Woo, Kyoungja; Moon, Jihyung; Choi, Kyu-Sil; Seong, Tae-Yeon; Yoon, Kwon-Ha

    2009-01-01

    We prepared five folate-conjugated lipophilic superparamagnetic iron oxide nanoparticles (F 5 -Liposuperparamagnetic iron oxide nanoparticles(SPIONs), 5.5 and 11 nm) and investigated their cellular uptake with KB cells, which is one of the representative folate-receptor over-expressing human epidermoid carcinoma cells, using MRI. The cellular uptake tests with the respective 5.5 and 11 nm F 5 -LipoSPIONs at a fixed particle concentration showed appreciable amount of receptor-mediated uptakes and the specificity was higher in 5.5 nm SPIONs, due to its higher folic acid (FA) density, without inhibition. However, the numbers of the particles taken up under FA inhibition were similar, irrespective of their sizes.

  13. Cellular uptake of folate-conjugated lipophilic superparamagnetic iron oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Kyoungja [Nano-Materials Research Center, Korea Institute of Science and Technology, P. O. Box 131, Cheongryang, Seoul 130-650 (Korea, Republic of)], E-mail: kjwoo@kist.re.kr; Moon, Jihyung [Nano-Materials Research Center, Korea Institute of Science and Technology, P. O. Box 131, Cheongryang, Seoul 130-650 (Korea, Republic of); Department of Materials Science and Engineering, Korea University, 5-1, Anam-Dong, Sungbook-Ku, Seoul, 136-713 (Korea, Republic of); Choi, Kyu-Sil [Division of Molecular Imaging, Samsung Biomedical Research Institute, Samsung Medical Center, 50 Ilwon-Dong, Kangnam-Ku, Seoul 135-710 (Korea, Republic of); Seong, Tae-Yeon [Department of Materials Science and Engineering, Korea University, 5-1, Anam-Dong, Sungbook-Ku, Seoul, 136-713 (Korea, Republic of); Yoon, Kwon-Ha [Institute for Radiological Imaging Science, Wonkwang University School of Medicine, 344-2, Shinyong, Iksan, Jeonbuk 570-749 (Korea, Republic of)

    2009-05-15

    We prepared five folate-conjugated lipophilic superparamagnetic iron oxide nanoparticles (F{sub 5}-Liposuperparamagnetic iron oxide nanoparticles(SPIONs), 5.5 and 11 nm) and investigated their cellular uptake with KB cells, which is one of the representative folate-receptor over-expressing human epidermoid carcinoma cells, using MRI. The cellular uptake tests with the respective 5.5 and 11 nm F{sub 5}-LipoSPIONs at a fixed particle concentration showed appreciable amount of receptor-mediated uptakes and the specificity was higher in 5.5 nm SPIONs, due to its higher folic acid (FA) density, without inhibition. However, the numbers of the particles taken up under FA inhibition were similar, irrespective of their sizes.

  14. Folic acid derivatives for PET imaging and therapy addressing folate receptor positive tumors

    International Nuclear Information System (INIS)

    Schieferstein, Hanno

    2013-01-01

    Folic acid, also known as vitamin B9, is the oxidized form of 5,6,7,8-tetrahydrofolate, which serves as methyl- or methylene donor (C1-building blocks) during DNA synthesis. Under physiological conditions the required amount of 5,6,7,8-tetrahydrofolate for survival of the cell is accomplished through the reduced folate carrier (RFC). In contrast, the supply of 5,6,7,8-tetrahydrofolate is insufficient under pathophysiological conditions of tumors due to an increased proliferation rate. Consequently, many tumor cells exhibit an (over)expression of the folate receptor. This phenomenon has been applied to diagnostics (PET, SPECT, MR) to image FR-positive tumors and on the other hand to treat malignancies related to a FR (over)expression. Based on this concept, a new 18 F-labeled folate for PET imaging has been developed and was evaluated in vivo using tumor-bearing mice. The incorporation of oligoethylene spacers into the molecular structure led to a significant enhancement of the pharmacokinetics in comparison to previously developed 18 F-folates. The liver uptake could be reduced by one sixth by remaining a tumor uptake of 3%ID/g leading to better contrast ratios. Encouraged by these results, a clickable 18 F-labeled serine-based prosthetic group has been synthesized, again with the idea to improve the metabolic and pharmacokinetic profile of hydrophilic radiotracers. Therefore, an alkyne-carrying azido-functionalized serine derivative for coupling to biomolecules was synthesized and a chlorine leaving group for 18 F-labeling, which could be accomplished using a microwave-assisted synthesis, a [K is contained in 2.2.2] + /carbonate system in DMSO. Radiochemical yields of 77±6% could be achieved. The promising results obtained from the FR-targeting concept in the diagnostic field have been transferred to the boron neutron capture therapy. Therefore, a folate derivative was coupled to different boron clusters and cell uptake studies were conducted. The synthesis of

  15. Cysteine Supplementation May be Beneficial in a Subgroup of Mitochondrial Translation Deficiencies.

    Science.gov (United States)

    Bartsakoulia, Marina; Mϋller, Juliane S; Gomez-Duran, Aurora; Yu-Wai-Man, Patrick; Boczonadi, Veronika; Horvath, Rita

    2016-08-30

    Mitochondrial encephalomyopathies are severe, relentlessly progressive conditions and there are very few effective therapies available to date. We have previously suggested that in two rare forms of reversible mitochondrial disease (reversible infantile respiratory chain deficiency and reversible infantile hepatopathy) supplementation with L-cysteine can improve mitochondrial protein synthesis, since cysteine is required for the 2-thiomodification of mitochondrial tRNAs. We studied whether supplementation with L-cysteine or N-acetyl-cysteine (NAC) results in any improvement of the mitochondrial function in vitro in fibroblasts of patients with different genetic forms of abnormal mitochondrial translation. We studied in vitro in fibroblasts of patients carrying the common m.3243A>G and m.8344A>G mutations or autosomal recessive mutations in genes affecting mitochondrial translation, whether L-cysteine or N-acetyl-cysteine supplementation have an effect on mitochondrial respiratory chain function. Here we show that supplementation with L-cysteine, but not with N-acetyl-cysteine partially rescues the mitochondrial translation defect in vitro in fibroblasts of patients carrying the m.3243A>G and m.8344A>G mutations. In contrast, N-acetyl-cysteine had a beneficial effect on mitochondrial translation in TRMU and MTO1 deficient fibroblasts. Our results suggest that L-cysteine or N-acetyl-cysteine supplementation may be a potential treatment for selected subgroups of patients with mitochondrial translation deficiencies. Further studies are needed to explore the full potential of cysteine supplementation as a treatment for patients with mitochondrial disease.

  16. Enhancement of L-cysteine production by disruption of yciW in Escherichia coli.

    Science.gov (United States)

    Kawano, Yusuke; Ohtsu, Iwao; Takumi, Kazuhiro; Tamakoshi, Ai; Nonaka, Gen; Funahashi, Eri; Ihara, Masaki; Takagi, Hiroshi

    2015-02-01

    Using in silico analysis, the yciW gene of Escherichia coli was identified as a novel L-cysteine regulon that may be regulated by the transcriptional activator CysB for sulfur metabolic genes. We found that overexpression of yciW conferred tolerance to L-cysteine, but disruption of yciW increased L-cysteine production in E. coli. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  17. Effects of cysteine protease inhibitors on rabbit cathepsin D maturation

    International Nuclear Information System (INIS)

    Samarel, A.M.; Ferguson, A.G.; Decker, R.S.; Lesch, M.

    1989-01-01

    To examine the effects of cysteine protease inhibitors on cathepsin D intracellular transport, proteolytic processing, and secretion, primary cultures of rabbit cardiac fibroblasts were grown to confluence and exposed to media containing leupeptin, E 64, or chloroquine. Cathepsin D maturation was then evaluated in pulse-chase biosynthetic labeling experiments. None of the three agents affected the charge modification of procathepsin D within the Golgi apparatus. However, all three agents interfered with the subsequent proteolytic processing of procathepsin D isoforms to active cathepsin D. Both leupeptin and E 64 caused the intracellular accumulation of large amounts of a Mr 51,000 processing intermediate. Trace amounts of this intermediate were also detected in chloroquine-treated cells. Combined activity assay and radioimmunoassay of cell lysates indicated that this partially processed form of cathepsin D possessed proteolytic activity. Whereas low medium concentrations of leupeptin (10-100 microM) but not E 64 appeared to stimulate procathepsin D secretion, neither agent appeared to have a major effect on the rate of proenzyme secretion at doses required to inhibit proteolytic maturation (1-10 mM). Furthermore, pretreatment of cells with 10 mM leupeptin appeared only to delay, but not prevent, the intracellular transport of cathepsin D to lysosomes. In contrast, chloroquine increased procathepsin D secretion in a dose-dependent manner, diverting the majority of newly synthesized procathepsin D from the intracellular protease(s) responsible for proteolytic processing. These results suggest that cysteine proteases participate in the proteolytic maturation of procathepsin D during the transport of newly synthesized enzyme to lysosomes, but cysteine protease-mediated proteolytic processing is not required for cathepsin D activation or lysosomal translocation

  18. Review of current evidence for folate in the prevention of neural tube ...

    African Journals Online (AJOL)

    In view of the association between folic acid status and NiD, we performed a study in rural and urban communities to determine whether folate or vitamin B12 status and/or abnormal homocyst(e)ine metabolism could explain why the incidence of NTD in rural areas is so high. (Homocyst(e)me (tHcy) refers to the sum of ...

  19. Circulating Unmetabolized Folic Acid: Relationship to Folate Status and Effect of Supplementation

    OpenAIRE

    Tam, Carolyn; O'Connor, Deborah; Koren, Gideon

    2012-01-01

    There are increasing concerns that exposure to unmetabolized folic acid, which results from folic acid intakes that overwhelm the liver's metabolic capacity, may be associated with adverse effects. In this paper, we examined the folic acid status of women of reproductive age in relation to dietary intake and the effect of folic acid supplementation (1.1 mg or 5 mg). Plasma unmetabolized folic acid was not significantly correlated with folate intake estimated by food frequency questionnaire or...

  20. Lack of association between folate-receptor autoantibodies and neural-tube defects.

    LENUS (Irish Health Repository)

    Molloy, Anne M

    2009-07-09

    BACKGROUND: A previous report described the presence of autoantibodies against folate receptors in 75% of serum samples from women with a history of pregnancy complicated by a neural-tube defect, as compared with 10% of controls. We sought to confirm this finding in an Irish population, which traditionally has had a high prevalence of neural-tube defects. METHODS: We performed two studies. Study 1 consisted of analysis of stored frozen blood samples collected from 1993 through 1994 from 103 mothers with a history of pregnancy complicated by a neural-tube defect (case mothers), 103 mothers with a history of pregnancy but no complication by a neural-tube defect (matched with regard to number of pregnancies and sampling dates), 58 women who had never been pregnant, and 36 men. Study 2, conducted to confirm that the storage of samples did not influence the folate-receptor autoantibodies, included fresh samples from 37 case mothers, 22 control mothers, 10 women who had never been pregnant, and 9 men. All samples were assayed for blocking and binding autoantibodies against folate receptors. RESULTS: In Study 1, blocking autoantibodies were found in 17% of case mothers, as compared with 13% of control mothers (odds ratio, 1.54; 95% confidence interval [CI], 0.70 to 3.39), and binding autoantibodies in 29%, as compared with 32%, respectively (odds ratio, 0.82; 95% CI, 0.44 to 1.50). Study 2 showed similar results, indicating that sample degradation was unlikely. CONCLUSIONS: The presence and titer of maternal folate-receptor autoantibodies were not significantly associated with a neural-tube defect-affected pregnancy in this Irish population.

  1. Rare allelic variants determine folate status in an unsupplemented European population

    Czech Academy of Sciences Publication Activity Database

    Pavlíková, Markéta; Sokolová, J.; Janošíková, B.; Melenovská, P.; Krupková, L.; Zvárová, Jana; Kožich, V.

    2012-01-01

    Roč. 142, č. 8 (2012), s. 1403-1409 ISSN 0022-3166 R&D Projects: GA MZd(CZ) NS10036 Institutional research plan: CEZ:AV0Z10300504 Keywords : glutamate-carboxypeptidase-ii * coronary-artery-disease * one-carbon metabolism * methylenetetrahydrofolate reductase * homocysteine concentrations * genetic-determinants * common mutation * serum folate * polymorphisms * prevalence Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 4.196, year: 2012

  2. UV-associated decline in systemic folate: implications for human nutrigenetics, health, and evolutionary processes.

    Science.gov (United States)

    Lucock, Mark; Beckett, Emma; Martin, Charlotte; Jones, Patrice; Furst, John; Yates, Zoe; Jablonski, Nina G; Chaplin, George; Veysey, Martin

    2017-03-01

    The purpose of this study was to examine whether UV exposure alters folate status according to C677T-MTHFR genotype, and to consider the relevance of this to human health and the evolutionary model of skin pigmentation. Total Ozone Mapping Spectrometer (TOMS) satellite data were used to examine surface UV-irradiance, as a marker of UV exposure, in a large (n = 649) Australian cross-sectional study population. PCR/RFLP analysis was used to genotype C677T-MTHFR. Overall, cumulative UV-irradiance (42 and 120 days pre-clinic) was significantly negatively related to red cell folate (RCF) levels. When the cohort was stratified by MTHFR-C677T genotype, the relationship between UV-irradiance (42 days pre-clinic) and RCF remained significant only in the cohorts containing carriers of the T allele. Statistically significant z-score statistics and interaction terms from genotype and UV-irradiance (p-interaction) demonstrated that genotype did modify the effect of UV-irradiance on RCF, with the largest effect of UV being demonstrated in the 677TT-MTHFR subjects. Data provide strong evidence that surface UV-irradiance reduces long-term systemic folate levels, and that this is influenced by the C677T-MTHFR gene variant. We speculate this effect may be due to 677TT-MTHFR individuals containing more 5,10CH 2 -H 4 PteGlu, and that this folate form may be particularly UV labile. Since UV-irradiance lowers RCF in an MTHFR genotype-specific way, there are likely implications for human health and the evolution of skin pigmentation. © 2016 Wiley Periodicals, Inc.

  3. Effect of L-cysteine on the oxidation of cyclohexane catalyzed by manganeseporphyrin.

    Science.gov (United States)

    Zhou, Wei-You; Tian, Peng; Chen, Yong; He, Ming-Yang; Chen, Qun; Chen, Zai Xin

    2015-06-01

    Effect of L-cysteine as the cocatalyst on the oxidation of cyclohexane by tert-butylhydroperoxide (TBHP) catalyzed by manganese tetraphenylporphyrin (MnTPP) has been investigated. The results showed that L-cysteine could moderately improve the catalytic activity of MnTPP and significantly increase the selectivity of cyclohexanol. Different from imidazole and pyridine, the L-cysteine may perform dual roles in the catalytic oxidation of cyclohexane. Besides as the axial ligand for MnTPP, the L-cysteine could also react with cyclohexyl peroxide formed as the intermediate to produce alcohol as the main product. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. L-cysteine suppresses ghrelin and reduces appetite in rodents and humans.

    Science.gov (United States)

    McGavigan, A K; O'Hara, H C; Amin, A; Kinsey-Jones, J; Spreckley, E; Alamshah, A; Agahi, A; Banks, K; France, R; Hyberg, G; Wong, C; Bewick, G A; Gardiner, J V; Lehmann, A; Martin, N M; Ghatei, M A; Bloom, S R; Murphy, K G

    2015-03-01

    High-protein diets promote weight loss and subsequent weight maintenance, but are difficult to adhere to. The mechanisms by which protein exerts these effects remain unclear. However, the amino acids produced by protein digestion may have a role in driving protein-induced satiety. We tested the effects of a range of amino acids on food intake in rodents and identified l-cysteine as the most anorexigenic. Using rodents we further studied the effect of l-cysteine on food intake, behaviour and energy expenditure. We proceeded to investigate its effect on neuronal activation in the hypothalamus and brainstem before investigating its effect on gastric emptying and gut hormone release. The effect of l-cysteine on appetite scores and gut hormone release was then investigated in humans. l-Cysteine dose-dependently decreased food intake in both rats and mice following oral gavage and intraperitoneal administration. This effect did not appear to be secondary to behavioural or aversive side effects. l-Cysteine increased neuronal activation in the area postrema and delayed gastric emptying. It suppressed plasma acyl ghrelin levels and did not reduce food intake in transgenic ghrelin-overexpressing mice. Repeated l-cysteine administration decreased food intake in rats and obese mice. l-Cysteine reduced hunger and plasma acyl ghrelin levels in humans. Further work is required to determine the chronic effect of l-cysteine in rodents and humans on appetite and body weight, and whether l-cysteine contributes towards protein-induced satiety.

  5. Properties of Folate Binding Protein Purified from Cow’s Milk

    Directory of Open Access Journals (Sweden)

    SUBANDRATE

    2012-09-01

    Full Text Available Folic acid played an important role in the metabolism of the body. To measure the serum folic acid levels could use the folate binding protein (FBP from cow’s milk with a technique analogous to ELISA. The aims of this study were to identify characteristics of FBP from cow’s milk and binding capacity of FBP to folic acid and to purify FBP from other whey protein passed through DEAE-cellulose chromatography column. Each of DEAE-cellulose peaks was passed in affinity chromatography column. FBP was released from affinity column with sodium acetate buffer pH 3.5. The purity of obtained FBP was demonstrated by a single spot in SDS-PAGE analysis and the estimated molecular weight of FBP was around 31 kDa. Our study indicated that 1 mol FBP bound 1 mol folic acid. Alkylation with iodoacetic acid decreased the binding capacity of FBP which suggested the presence of a–SH or imidazol group in its active site. The importance of disulfide bridge was proven by decreasing of folate binding capacity of FBP after -mercaptoethanol treatment. In contrary, the folate binding didn need Ca2+ ion, as indicated by EDTA test which gave the same result as control.

  6. Gene-Gene Interactions in the Folate Metabolic Pathway and the Risk of Conotruncal Heart Defects

    Directory of Open Access Journals (Sweden)

    Philip J. Lupo

    2010-01-01

    Full Text Available Conotruncal and related heart defects (CTRD are common, complex malformations. Although there are few established risk factors, there is evidence that genetic variation in the folate metabolic pathway influences CTRD risk. This study was undertaken to assess the association between inherited (i.e., case and maternal gene-gene interactions in this pathway and the risk of CTRD. Case-parent triads (n=727, ascertained from the Children's Hospital of Philadelphia, were genotyped for ten functional variants of nine folate metabolic genes. Analyses of inherited genotypes were consistent with the previously reported association between MTHFR A1298C and CTRD (adjusted P=.02, but provided no evidence that CTRD was associated with inherited gene-gene interactions. Analyses of the maternal genotypes provided evidence of a MTHFR C677T/CBS 844ins68 interaction and CTRD risk (unadjusted P=.02. This association is consistent with the effects of this genotype combination on folate-homocysteine biochemistry but remains to be confirmed in independent study populations.

  7. Folate receptor targeted 17-allylamino-17-demethoxygeldanamycin (17-AAG) loaded polymeric nanoparticles for breast cancer.

    Science.gov (United States)

    Saxena, Vipin; Naguib, Youssef; Hussain, M Delwar

    2012-06-01

    Low water solubility and hepatotoxicity limited the clinical use of 17-allylamino-17-demethoxy geldanamycin (17-AAG), an inhibitor of heat shock protein 90 (HSP90). Folate targeted polylactide-co-glycolide-polyethylene glycol-folic acid (PLGA-PEG-FA) nanoparticles containing 17-AAG were prepared and characterized. Cellular uptake and in vitro cytotoxicity of the prepared nanoparticles were determined in MCF-7 human breast cancer cells. The particle size of 17-AAG loaded folate targeted nanoparticles was 238.67±3.52 nm, drug loading was 8.25±2.49% and about 80% of drug was released from the nanoparticles over 10 days. Cellular uptake studies showed much higher intracellular uptake of folate targeted nanoparticle as compared to nontargeted nanoparticles. Cytotoxicity study showed 2 fold increase (PAAG loaded PLGA-PEG-FA nanoparticles might be developed as a targeted delivery system for breast and other cancer treatment. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. The association of folate pathway and DNA repair polymorphisms with susceptibility to childhood acute lymphoblastic leukemia.

    Science.gov (United States)

    Goričar, Katja; Erčulj, Nina; Faganel Kotnik, Barbara; Debeljak, Maruša; Hovnik, Tinka; Jazbec, Janez; Dolžan, Vita

    2015-05-15

    Genetic factors may play an important role in susceptibility to childhood acute lymphoblastic leukemia (ALL). The aim of our study was to evaluate the associations of genetic polymorphisms in folate pathway and DNA repair genes with susceptibility to ALL. In total, 121 children with ALL and 184 unrelated healthy controls of Slovenian origin were genotyped for 14 polymorphisms in seven genes of folate pathway, base excision repair and homologous recombination repair (TYMS, MTHFR, OGG1, XRCC1, NBN, RAD51, and XRCC3). In addition, the exon 6 of NBN was screened for the presence of mutations using denaturing high performance liquid chromatography. Twelve polymorphisms were in Hardy-Weinberg equilibrium in controls and their genotype frequencies were in agreement with those reported in other Caucasian populations. Among the investigated polymorphisms and mutations, NBN Glu185Gln significantly decreased susceptibility to B-cell ALL (p=0.037), while TYMS 3R allele decreased susceptibility to T-cell ALL (p=0.011). Moreover, significantly decreased susceptibility to ALL was observed for MTHFR TA (p=0.030) and RAD51 GTT haplotypes (p=0.016). Susceptibility to ALL increased with the increasing number of risk alleles (ptrend=0.007). We also observed significant influence of hOGG-RAD51 and NBN-RAD51 interactions on susceptibility to ALL. Our results suggest that combination of several polymorphisms in DNA repair and folate pathways may significantly affect susceptibility to childhood ALL. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Vitamin D, Homocysteine, and Folate in Subcortical Vascular Dementia and Alzheimer Dementia.

    Science.gov (United States)

    Moretti, Rita; Caruso, Paola; Dal Ben, Matteo; Conti, Corrado; Gazzin, Silvia; Tiribelli, Claudio

    2017-01-01

    Dementia is a worldwide health problem which affects millions of patients; Alzheimer's disease (AD) and subcortical vascular dementia (sVAD) are the two most frequent forms of its presentation. As no definite therapeutic options have been discovered, different risk factors for cognitive impairment have been searched for potential therapies. This report focuses on the possible evidence that vitamin D deficiency and hyper-homocysteinemia can be considered as two important factors for the development or the progression of neurodegenerative or vascular pathologies. To this end, we assessed: the difference in vascular risk factors and vitamin D-OH25 levels among groups of sVAD, AD, and healthy age-matched controls; the association of folate, B12, homocysteine, and vitamin D with sVAD/AD and whether a deficiency of vitamin D and an increment in homocysteine levels may be related to neurodegenerative or vessel damages. The commonly-considered vascular risk factors were collected in 543 patients and compared with those obtained from a healthy old volunteer population. ANOVA group comparison showed that vitamin D deficiency was present in demented cases, as well as low levels of folate and high levels of homocysteine, more pronounced in sVAD cases. The statistical models we employed, with regression models built, and adjustments for biochemical, demographic and neuropsychiatric scores, confirmed the association between the three measures (folate decrease, hyperhomocysteinemia and vitamin D decrease) and dementia, more pronounced in sVAD than in AD.

  10. Positively charged gold nanoparticles capped with folate quaternary chitosan: Synthesis, cytotoxicity, and uptake by cancer cells.

    Science.gov (United States)

    Yen, Hui-Ju; Young, Yen-An; Tsai, Tsung-Neng; Cheng, Kuang-Ming; Chen, Xin-An; Chen, Ying-Chuan; Chen, Cheng-Cheung; Young, Jenn-Jong; Hong, Po-da

    2018-03-01

    In this study, we synthesized various quaternary chitosan derivatives and used them to stabilize gold nanoparticles (AuNPs). These chitosan derivatives comprised N-(2-hydroxy)propyl-3-trimethylammonium chitosan chloride (HTCC), folate-HTCC, galactosyl-HTCC, and their fluorescein isothiocyanate-conjugated derivatives. Various positively surface-charged AuNPs were prepared under alkaline conditions using glucose as a reducing agent in the presence of the HTCC derivatives (HTCCs). The effects of the concentration of NaOH, glucose, and HTCCs on the particles size, zeta potential, and stability were studied in detail. Cell cycle assays verify that none of the HTCCs or HTCCs-AuNPs was cytotoxic to human umbilical vein endothelial cells. Flow cytometry analysis showed that the folate HTCC-AuNPs were internalized in Caco-2, HepG2, and HeLa cancer cells to a significantly greater extent than AuNPs without folate. But, galactosyl HTCC-AuNPs only showed high cell uptake by HepG2 cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. PENYULUHAN DAN PEMBERIAN TABLET ASAM FOLAT BAGI IBU-IBU USIA REPRODUKTIF DI DESA ABIANSEMAL, BADUNG

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    DESAK MADE WIHANDANI

    2012-09-01

    Full Text Available ABSTRACT Folat deficiency that happened during early period of pregnancy, has known as one of the factor that cause fetal abnormalities. That why it is important for pregnant women to get information about the rule of folic acid in preventing fetal abnormalities. From 93 women within reproductive age, 6 of them were pregnant. Pregnant women were given 30 tablets of 0,4 mg folic acid taken once a day, and the less 87 women who were not in pregnant state received 10 tablets of folic acid to be taken once a day. PENYULUHAN DAN PEMBERIAN TABLET ASAM FOLAT BAGI IBU-IBU USIA REPRODUKTIF DI DESA ABIANSEMAL, BADUNG DESAK MADE WIHANDANI, NYOMAN AGUS BAGIADA DAN WAYAN SURUDARMA Bagian Biokimia Fakultas Kedokteran Universitas Udayana ABSTRACT Folat deficiency that happened during early period of pregnancy, has known as one of the factor that cause fetal abnormalities. That why it is important for pregnant women to get information about the rule of folic acid in preventing fetal abnormalities. From 93 women within reproductive age, 6 of them were pregnant. Pregnant women were given 30 tablets of 0,4 mg folic acid taken once a day, and the less 87 women who were not in pregnant state received 10 tablets of folic acid to be taken once a day.

  12. Lipid-Polymer Nanoparticles for Folate-Receptor Targeting Delivery of Doxorubicin.

    Science.gov (United States)

    Zheng, Mingbin; Gong, Ping; Zheng, Cuifang; Zhao, Pengfei; Luo, Zhenyu; Ma, Yifan; Cai, Lintao

    2015-07-01

    A biocompatible PLGA-lipid hybrid nanoparticles (NPs) was developed for targeted delivery of anticancer drugs with doxorubicin (DOX). The hydrodynamic diameter and zeta potential of DOX-loaded PLGA-lipid NPs (DNPs) were affected by the mass ratio of Lipid/PLGA or DSPE-PEG-COOH/Lecithin. At the 1:20 drug/polymer mass ratio, the mean hydrodynamic diameter of DNPs was the lowest (99.2 1.83 nm) and the NPs presented the encapsulation efficiency of DOX with 42.69 1.30%. Due to the folate-receptor mediated endocytosis, the PLGA-lipid NPs with folic acid (FA) targeting ligand showed significant higher uptake by folate-receptor-positive MCF-7 cells as compared to PLGA-lipid NPs without folate. Confocal microscopic observation and flow cytometry analysis also supported the enhanced cellular uptake of the FA-targeted NPs. The results indicated that the FA-targeted DNPs exhibited higher cytotoxicity in MCF-7 cells compared with non-targeted NPs. The lipid-polymer nanoparticles provide a solution of biocompatible nanocarrier for cancer targeting therapy.

  13. Neonatal hydrocephalus is a result of a block in folate handling and metabolism involving 10-formyltetrahydrofolate dehydrogenase.

    Science.gov (United States)

    Naz, Naila; Jimenez, Alicia Requena; Sanjuan-Vilaplana, Anna; Gurney, Megan; Miyan, Jaleel

    2016-08-01

    Folate is vital in a range of biological processes and folate deficiency is associated with neurodevelopmental disorders such as neural tube defects and hydrocephalus (HC). 10-formyl-tetrahydrofolate-dehydrogenase (FDH) is a key regulator for folate availability and metabolic interconversion for the supply of 1-carbon groups. In previous studies, we found a deficiency of FDH in CSF associated with the developmental deficit in congenital and neonatal HC. In this study, we therefore aimed to investigate the role of FDH in folate transport and metabolism during the brain development of the congenital hydrocephalic Texas (H-Tx) rat and normal (Sprague-Dawley) rats. We show that at embryonic (E) stage E18 and E20, FDH-positive cells and/or vesicles derived from the cortex can bind methyl-folate similarly to folate receptor alpha, the main folate transporter. Hydrocephalic rats expressed diminished nuclear FDH in both liver and brain at all postnatal (P) ages tested (P5, P15, and P20) together with a parallel increase in hepatic nuclear methyl-folate at P5 and cerebral methylfolate at P15 and P20. A similar relationship was found between FDH and 5-methyl cytosine, the main marker for DNA methylation. The data indicated that FDH binds and transports methylfolate in the brain and that decreased liver and brain nuclear expression of FDH is linked with decreased DNA methylation which could be a key factor in the developmental deficits associated with congenital and neonatal HC. Folate deficiency is associated with neurodevelopmental disorders such as neural tube defects and hydrocephalus. 10-formyl-tetrahydrofolate-dehydrogenase (FDH) is a key regulator for folate availability and metabolic interconversion. We show that FDH binds and transports methylfolate in the brain. Moreover, we found that a deficiency of FDH in the nucleus of brain and liver is linked with decreased DNA methylation which could be a key factor in the developmental deficits associated with congenital and

  14. Serum Folate Shows an Inverse Association with Blood Pressure in a Cohort of Chinese Women of Childbearing Age: A Cross-Sectional Study.

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    Minxue Shen

    Full Text Available It has been reported that higher folate intake from food and supplementation is associated with decreased blood pressure (BP. The association between serum folate concentration and BP has been examined in few studies. We aim to examine the association between serum folate and BP levels in a cohort of young Chinese women.We used the baseline data from a pre-conception cohort of women of childbearing age in Liuyang, China, for this study. Demographic data were collected by structured interview. Serum folate concentration was measured by immunoassay, and homocysteine, blood glucose, triglyceride and total cholesterol were measured through standardized clinical procedures. Multiple linear regression and principal component regression model were applied in the analysis.A total of 1,532 healthy normotensive non-pregnant women were included in the final analysis. The mean concentration of serum folate was 7.5 ± 5.4 nmol/L and 55% of the women presented with folate deficiency (< 6.8 nmol/L. Multiple linear regression and principal component regression showed that serum folate levels were inversely associated with systolic and diastolic BP, after adjusting for demographic, anthropometric, and biochemical factors.Serum folate is inversely associated with BP in non-pregnant women of childbearing age with high prevalence of folate deficiency.

  15. Studies of food folates and folic acid deficiency by radioligand competitive binding assay techniques. Part of a coordinated programme on in vitro assay techniques

    International Nuclear Information System (INIS)

    Hettiarachchy, N.S.

    1981-01-01

    Conjugese extracted from winged bean or sweet potato leaves was used to release folate from Sri Lankan foodstuffs. Total folate was then estimated by competitive binding assay using goat milk as binding agent. Of 33 foodstuffs investigated, green gram, cow pea, and red gram among the pulses and mukunuvenna, amaranth and centella among the leafy vegetables were shown to be rich sources of folate. Between 20 and 60% of total folate was lost when such foodstuffs were boiled for 60 minutes. It is thus advisable that pulses and leafy vegetables be boiled only for the minimum time necessary for tenderization before consumption

  16. Copper oxide assisted cysteine hierarchical structures for immunosensor application

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, Chandra Mouli [Biomedical Instrumentation Section, CSIR-National Physical Laboratory, New Delhi 110012 (India); Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi 221005 (India); Sumana, Gajjala, E-mail: sumanagajjala@gmail.com [Biomedical Instrumentation Section, CSIR-National Physical Laboratory, New Delhi 110012 (India); Tiwari, Ida [Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi 221005 (India)

    2014-09-08

    The present work describes the promising electrochemical immunosensing strategy based on copper (II) assisted hierarchical cysteine structures (CuCys) varying from star to flower like morphology. The CuCys having average size of 10 μm have been synthesised using L-Cysteine as initial precursor in presence of copper oxide under environmentally friendly conditions in aqueous medium. To delineate the synthesis mechanism, detailed structural investigations have been carried out using characterization techniques such as X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy. The electrochemical behaviour of self-assembled CuCys on gold electrode shows surface controlled electrode reaction with an apparent electron transfer rate constant of 3.38 × 10{sup −4 }cm s{sup −1}. This innovative platform has been utilized to fabricate an immunosensor by covalently immobilizing monoclonal antibodies specific for Escherichia coli O157:H7 (E. coli). Under the optimal conditions, the fabricated immunosensor is found to be sensitive and specific for the detection of E. coli with a detection limit of 10 cfu/ml.

  17. Folate-modified lipid–polymer hybrid nanoparticles for targeted paclitaxel delivery

    Directory of Open Access Journals (Sweden)

    Zhang L

    2015-03-01

    Full Text Available Linhua Zhang,1 Dunwan Zhu,1 Xia Dong,1 Hongfan Sun,1 Cunxian Song,1 Chun Wang,2 Deling Kong1 1Tianjin Key Laboratory of Biomaterials, Institute of Biomedical Engineering, Peking Union Medical College and Chinese Academy of Medical Sciences, Tianjin, People’s Republic of China; 2Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA Abstract: The purpose of this study was to develop a novel lipid–polymer hybrid drug carrier comprised of folate (FA modified lipid-shell and polymer-core nanoparticles (FLPNPs for sustained, controlled, and targeted delivery of paclitaxel (PTX. The core-shell NPs consist of 1 a poly(ε-caprolactone hydrophobic core based on self-assembly of poly(ε-caprolactone–poly(ethylene glycol–poly(ε-caprolactone (PCL-PEG-PCL amphiphilic copolymers, 2 a lipid monolayer formed with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy (polyethylene glycol-2000] (DSPE-PEG2000, 3 a targeting ligand (FA on the surface, and were prepared using a thin-film hydration and ultrasonic dispersion method. Transmission electron microscopy and dynamic light scattering analysis confirmed the coating of the lipid monolayer on the hydrophobic polymer core. Physicochemical characterizations of PTX-loaded FLPNPs, such as particle size and size distribution, zeta potential, morphology, drug loading content, encapsulation efficiency, and in vitro drug release, were also evaluated. Fluorescent microscopy proved the internalization efficiency and targeting ability of the folate conjugated on the lipid monolayer for the EMT6 cancer cells which overexpress folate receptor. In vitro cytotoxicity assay demonstrated that the cytotoxic effect of PTX-loaded FLPNPs was lower than that of Taxol®, but higher than that of PTX-loaded LPNPs (without folate conjugation. In EMT6 breast tumor model, intratumoral administration of PTX-loaded FLPNPs showed similar antitumor efficacy but low toxicity compared to Taxol®. More

  18. Milder clinical and biochemical phenotypes associated with the c.482G>A (p.Arg161Gln) pathogenic variant in cobalamin C disease: Implications for management and screening.

    Science.gov (United States)

    Almannai, Mohammed; Marom, Ronit; Divin, Kristian; Scaglia, Fernando; Sutton, V Reid; Craigen, William J; Lee, Brendan; Burrage, Lindsay C; Graham, Brett H

    2017-09-01

    Cobalamin C disease is a multisystemic disease with variable manifestations and age of onset. Genotype-phenotype correlations are well-recognized in this disorder. Here, we present a large cohort of individuals with cobalamin C disease, several of whom are heterozygous for the c.482G>A pathogenic variant (p.Arg161Gln). We compared clinical characteristics of individuals with this pathogenic variant to those who do not have this variant. To our knowledge, this study represents the largest single cohort of individuals with the c.482G>A (p.Arg161Gln) pathogenic variant. A retrospective chart review of 27 individuals from 21 families with cobalamin C disease who are followed at our facility was conducted. 13 individuals (48%) are compound heterozygous with the c.482G>A (p.Arg161Gln) on one allele and a second pathogenic variant on the other allele. Individuals with the c.482G>A (p.Arg161Gln) pathogenic variant had later onset of symptoms and easier metabolic control. Moreover, they had milder biochemical abnormalities at presentation which likely contributed to the observation that 4 individuals (31%) in this group were missed by newborn screening. The c.482G>A (p.Arg161Gln) pathogenic variant is associated with milder disease. These individuals may not receive a timely diagnosis as they may not be identified on newborn screening or because of unrecognized, late onset symptoms. Despite the milder presentation, significant complications can occur, especially if treatment is delayed. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Effect of Smoking and Folate Levels on the Efficacy of Folic Acid Therapy in Prevention of Stroke in Hypertensive Men.

    Science.gov (United States)

    Zhou, Ziyi; Li, Jianping; Yu, Yaren; Li, Youbao; Zhang, Yan; Liu, Lishun; Song, Yun; Zhao, Min; Wang, Yu; Tang, Genfu; He, Mingli; Xu, Xiping; Cai, Yefeng; Dong, Qiang; Yin, Delu; Huang, Xiao; Cheng, Xiaoshu; Wang, Binyan; Hou, Fan Fan; Wang, Xiaobin; Qin, Xianhui; Huo, Yong

    2018-01-01

    We aimed to examine whether the efficacy of folic acid therapy in the primary prevention of stroke is jointly affected by smoking status and baseline folate levels in a male population in a post hoc analysis of the CSPPT (China Stroke Primary Prevention Trial). Eligible participants of the CSPPT were randomly assigned to a double-blind daily treatment of a combined enalapril 10-mg and folic acid 0.8-mg tablet or an enalapril 10-mg tablet alone. In total, 8384 male participants of the CSPPT were included in the current analyses. The primary outcome was first stroke. The median treatment duration was 4.5 years. In the enalapril-alone group, the first stroke risk varied by baseline folate levels and smoking status (never versus ever). Specifically, there was an inverse association between folate levels and first stroke in never smokers ( P for linear trend=0.043). However, no such association was found in ever smokers. A test for interaction between baseline folate levels and smoking status on first stroke was significant ( P =0.045). In the total sample, folic acid therapy significantly reduced the risk of first stroke in never smokers with folate deficiency (hazard risk, 0.36; 95% confidence interval, 0.16-0.83) and in ever smokers with normal folate levels (hazard risk, 0.69; 95% confidence interval, 0.48-0.99). Baseline folate levels and smoking status can interactively affect the risk of first stroke. Our data suggest that compared with never smokers, ever smokers may require a higher dosage of folic acid to achieve a greater beneficial effect on stroke. Our findings need to be confirmed by future randomized trials. URL: https://www.clinicaltrials.gov. Unique identifier: NCT00794885. © 2017 American Heart Association, Inc.

  20. SERUM METHYLMALONIC ACID DAN HOMOCYSTEIN DALAM MENDIAGNOSIS ANEMIA MEGALOBLASTIK AKIBAT DEFISIENSI KOBALAMIN DAN FOLAT PADA TRAVEL MEDICINE

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    Made Gian Indra Rahayuda

    2014-09-01

    Full Text Available Anemia adalah salah satu masalah kesehatan global yang utama, terutama pada negara-negara berkembang.Anemia adalah kondisi dimana massa sel darah merah dan/atau massa hemoglobin yang beredar dalam tubuh menurun hingga dibawah kadar normal sehingga tidak dapat berfungsi dengan baik dalam menyediakan oksigen untuk jaringan tubuh. Salah satu jenis yang banyak ditemukan adalah anemia megaloblastik.Anemia megaloblastik paling banyak disebabkan oleh kekurangan vitamin B12(kobalamin dan folat.Salah satu penyebab anemia defisiensi kobalamin dan folat adalah tropical sprue.Anemia defisiensi kobalamin dan asam folat memberikan gambaran yang serupa namun pada defisiensi kobalamin terdapat gejala neuropati.Batas normal serum folat antara 3-15 ng/mL.Folat eritrosit batas normalnya dari 150 – 600 ng/mL.Pada defisiensi kobalamin, serum kobalamin menurun di bawah cut off point100pg/mL (normalnya 100- 400pg/mL.Pemeriksaan lain seperti homocystein, methylmalonic acid, atau formioglutamic acid(FIGLU yang meningkat pada urin dapat memastikan diagnosis defisiensi kobalamindan asam folat. Belum ada konsensus mengenai cut off point Homocystein dan MMA. Homocysteine telah dianggap meningkat bila kadarnya di atas 12-14 µmol/L pada wanita dan di atas 14-15 µmol/L. Menurut penelitian yang dilakukan Robert et al pada kasus defisiensi kobalamin, kadar serum tHcy> 15.0 µmol/L.Kebanyakan penelitian menganggap peningkatan MMA pada defisiensi kobalamin adalah >0.28 µmol/L, tapi cut off point yang beredar bervariasi antara 0.21-0.48 µmol/L.Kadar MMA meningkat dalam serumdan urin pada defisiensi kobalamin, sedangkan pada defisiensi folat MMA normal.