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C E West

Publications and source records attributed to C E West.

At least 19 recordsLinked to original sources
PubMed2006

Characterization of the three Arabidopsis thaliana RAD21 cohesins reveals differential responses to ionizing radiation.

The RAD21/REC8 gene family has been implicated in sister chromatid cohesion and DNA repair in several organisms. Unlike most eukaryotes, Arabidopsis thaliana has three RAD21 gene homologues, and their cloning and characterization are reported here. All three genes, AtRAD21.1, AtRAD21.2, and AtRAD21.3, are expressed in tissues rich in cells undergoing cell division, and AtRAD21.3 shows the highest relative level of expression. An increase in steady-state levels of AtRAD21.1 transcript was also observed, specifically after the induction of DNA damage. Phenotypic analysis of the atrad21.1 and atrad21.3 mutants revealed that neither of the single mutants was lethal, probably due to the redundancy in function of the AtRAD21 genes. However, AtRAD21.1 plays a critical role in recovery from DNA damage during seed imbibition, prior to germination, as atrad21.1 mutant seeds are hypersensitive to radiation damage.

Arabidopsis↗
PubMed2005

Determinants of CD4 counts among HIV-negative Ethiopians: role of body mass index, gender, cigarette smoking, khat (Catha Edulis) chewing, and possibly altitude?

To study the determinants of CD4% and CD4 counts among HIV-negative Ethiopians, and to identify factors susceptible to explain the low CD4 counts observed among Ethiopian subjects. Cohort studies among factory workers in Akaki and Wonji, Ethiopia. Clinical and laboratory examinations, including determination of HIV serological status and T-cell subsets, were performed during follow-up visits every six months. In addition, micronutrients (retinol, carotenoids, tocopherol, transferrin receptor, and selenium) plasma concentrations were determined in a subset of 38 HIV-positive and 121 HIV-negative participants. HIV-negative participants with at least one CD4 count measurement were 157 females in Akaki, 203 males in Akaki, and 712 males in Wonji. CD4 counts were independently and positively associated with body mass index (through an increase in lymphocyte counts), female gender (through an increase in CD4%), cigarette smoking (through an increase in CD4%), khat chewing (through an increase in both lymphocyte counts and CD4%), and Akaki study site (through a large increase in lymphocyte counts compensating a decrease in CD4%). Intestinal parasitic infections were not associated with CD4% or CD4 counts. Retinol, carotenoids, and alpha-tocopherol plasma concentrations decreased with HIV infection and advancing immunosuppression, but were not associated with CD4 counts among HIV-negative subjects. Low body mass index among Ethiopians may have contributed to their overall low CD4 counts. Other factors remain to be elucidated.

Adult↗
PubMed2005

Low plasma selenium concentrations, high plasma human immunodeficiency virus load and high interleukin-6 concentrations are risk factors associated with anemia in adults presenting with pulmonary tuberculosis in Zomba district, Malawi.

BACKGROUND: Although anemia is common among adults with pulmonary tuberculosis and human immunodeficiency virus (HIV) infection in sub-Saharan Africa, the factors contributing to its pathogenesis have not been well characterized. OBJECTIVE: To characterize the antioxidant micronutrient status, interleukin-6 (IL-6) concentrations, and HIV load in relationship with anemia in adults with pulmonary tuberculosis. SETTING: Zomba district, Malawi. METHODS: Erythropoietin, IL-6, plasma HIV load, and markers of micronutrient status (hemoglobin (Hb), plasma concentrations of retinol, alpha-tocopherol, carotenoids, ferritin, zinc, and selenium) were measured in 500 adults who presented with pulmonary tuberculosis in Zomba Central Hospital, Malawi. RESULTS: Among 370 HIV-positive and 130 HIV-negative adults, the prevalence of anemia was 88 and 77%, respectively (P = 0.002), and moderate to severe anemia (Hb < 80 g/l) occurred in 30 and 15%, respectively (P = 0.001). Geometric mean IL-6 concentration was 21.1 pg/ml, with no difference between HIV-positive and -negative adults. The erythropoietin response to anemia was not different between adults with elevated IL-6 and those with lower IL-6 concentrations. In a multivariate logistic regression model, HIV load, and lower plasma selenium concentrations were associated with moderate to severe anemia. In a final multivariate linear regression model, IL-6, plasma HIV load, and plasma selenium concentrations were associated with Hb concentrations. CONCLUSION: This study suggests that low selenium concentrations, high HIV load, and high IL-6 concentrations are associated with anemia in adults with pulmonary tuberculosis in sub-Saharan Africa.

Adult↗
PubMed2005

Bioavailability of folic acid from fortified pasteurised and UHT-treated milk in humans.

OBJECTIVE: The aim of this study was to investigate whether milk fortified with folic acid enhances the folate status of humans and whether the presence of folate-binding proteins (FBP) in pasteurised milk affects the bioavailability of folic acid from fortified milk. In untreated and pasteurised milk, folate occurs bound to FBP, while FBP is (partly) denatured in ultra-high-temperature (UHT)-treated milk. The effect of FBP on folate bioavailability is still unclear. DESIGN, SUBJECTS AND SETTING: Healthy, free-living subjects (n=69) aged 18-49 y participated in a 4-week double-blind, placebo-controlled dietary intervention study. INTERVENTION: In addition to a fully controlled diet, the subjects consumed each day 500 ml of pasteurised or UHT milk, either fortified or not with 200 mug folic acid. RESULTS: Consumption of fortified milk increased folate concentrations in serum and in red blood cells (RBC) by 6.6-7.0 nmol/l (P<0.001) and 32-36 nmol/l (P<0.01), respectively. Similarly, plasma homocysteine concentrations were lowered 0.88-0.89 micromol/l (P=0.001) in subjects who consumed fortified milk. The bioavailability of folic acid from pasteurised milk relative to that of folic acid from UHT milk was 74-94% (NS), depending on the parameter used. CONCLUSIONS: Milk fortified to supply an additional 200 microg of folic acid/s substantially increased folate status, and decreased plasma total homocysteine concentrations in young, healthy subjects. Milk is therefore a suitable matrix for fortification to enhance the folate status in humans. No significant effect of endogenous FBP was found on the bioavailability of folic acid from milk.

Adolescent↗
PubMed2004

Reduced production of immunoregulatory cytokines in vitamin A- and zinc-deficient Indonesian infants.

OBJECTIVE: To determine effects of vitamin A, zinc and iron deficiency in Indonesian infants on the ability to produce immunoregulatory cytokines. DESIGN, SETTING AND SUBJECTS: Immunological assessment was done in 59 infants participating in a cross-sectional nutritional survey in rural West Java, Indonesia. Production of T-helper cell type-1 (Th1, cell-mediated) cytokines interferon-gamma (IFN-gamma), interleukin-12 (IL-12), interleukin-18 (IL-18) and T-helper cell type-2 (Th2, humoral) cytokine interleukin-6 (IL-6) were measured after stimulation with lipopolysaccharide and phytohemagglutinin in an ex vivo whole blood culture system. Circulating neopterin concentrations were determined as an indicator of in vivo macrophage activity. RESULTS: Of the infants, 48% were vitamin A deficient, 44% were anemic (with 17% having iron deficiency anemia), and 17% were zinc deficient. Vitamin-A deficient infants had significantly reduced ex vivo production of IFN-gamma, but also significantly higher circulating neopterin concentrations. Production of IFN-gamma and IL-12 were strongly correlated, IFN-gamma and IL-18 production were not. Zinc deficiency was accompanied by significantly reduced white blood cell counts and reduced ex vivo production of IL-6. Iron status was not related to cytokine production. CONCLUSIONS: This study shows that in vitamin A deficiency there is Th1 dominance in a steady state, combined however with impairment of the Th1 response after stimulation, whereas in zinc deficiency, there is a decreased Th2 response. Overall, vitamin A deficiency and zinc deficiency have marked albeit different effects on the immunocompetence of infants, affecting both cell-mediated and humoral components of the immune system.

Antibody Formation↗
PubMed2004

Choice of a start codon in a single transcript determines DNA ligase 1 isoform production and intracellular targeting in Arabidopsis thaliana.

DNA ligase 1 (AtLIG1) is the only essential DNA ligase activity in Arabidopsis and is implicated in the important processes of DNA replication, repair and recombination and in transgene insertion during Agrobacterium-mediated plant transformations. The mitochondrial and nuclear forms of DNA ligase 1 in Arabidopsis are translated from a single mRNA species through the control of translation initiation from either the first (M1) or second (M2) in-frame AUG codons respectively. Translation from a third in-frame AUG codon (M3) occurs on transcripts in which M1 and M2 are mutagenized to stop codons. Wild-type AtLIG1-GFP constructs (where GFP stands for green fluorescent protein) can be targeted in planta to both the nucleus and mitochondria. AtLIG1-GFP translation from M1 specifically targets the fusion protein only to mitochondria in planta, whereas translation from M2 or M3 targets the fusion protein only to the nucleus. Interestingly, the AtLIG1-GFP fusion protein in which translation is initiated from M1 contains both an N-terminal mtPS (mitochondrial targeting presequence) and a nuclear localization signal; nonetheless, this protein is only targeted to the mitochondria. This result raises intriguing questions on the translational control mechanisms that regulate how the protein products of a single transcript are targeted to more than one cellular compartment.

Amino Acid Sequence↗
PubMed2004

Arabidopsis DNA double-strand break repair pathways.

DSBs (double-strand breaks) are one of the most serious forms of DNA damage that can occur in a cell's genome. DNA replication in cells containing DSBs, or following incorrect repair, may result in the loss of large amounts of genetic material, aneuploid daughter cells and cell death. There are two major pathways for DSB repair: HR (homologous recombination) uses an intact copy of the damaged region as a template for repair, whereas NHEJ (non-homologous end-joining) rejoins DNA ends independently of DNA sequence. In most plants, NHEJ is the predominant DSB repair pathway. Previously, the Arabidopsis NHEJ mutant atku80 was isolated and found to display hypersensitivity to bleomycin, a drug that causes DSBs in DNA. In the present study, the transcript profiles of wild-type and atku80 mutant plants grown in the presence and absence of bleomycin are determined by microarray analysis. Several genes displayed very strong transcriptional induction specifically in response to DNA damage, including the characterized DSB repair genes AtRAD51 and AtBRCA1. These results identify novel candidate genes that encode components of the DSB repair pathways active in NHEJ mutant plants.

Arabidopsis↗
PubMed2002

Antioxidant properties of differently processed spinach products.

The effect of variously processed spinach products (whole-leaf, minced and enzymatically liquefied spinach) on lipid oxidation was determined. In an autoxidative methyl linoleate (MeLo) system the inhibition of hydroperoxide formation, measured by HPLC after three days of oxidation, was in descending order: whole-leaf > liquefied > minced spinach. The inhibition of formation of thiobarbituric acid-reactive substances (TBARS) and hexanal by spinach was determined in cooked meatballs with added spinach after two days of storage at 4 degrees C. The formation of TBARS was inhibited by liquefied spinach at 200 g/kg meat; all other spinach products tested at 100 and 200 g/kg were pro-oxidative. The formation of hexanal was inhibited by both minced and liquefied spinach at 100 and 200 g/kg meat. The variously processed spinach products behaved differently when tested for their antioxidant activity (MeLo) or oxidative stability (meatballs). We conclude that the effect of spinach products on lipid oxidation is affected by processing.

Aldehydes↗
PubMed2002

Randomised double-blind trial of the effect of vitamin A supplementation of Indonesian pregnant women on morbidity and growth of their infants during the first year of life.

OBJECTIVE: To investigate whether supplementation with vitamin A together with iron of Indonesian pregnant women decreases morbidity and improves growth of their infants during the first year of life. DESIGN: Women from a rural area in West Java, Indonesia, were randomly assigned on an individual basis to double-blind supplementation once weekly from approximately 18 weeks of pregnancy until delivery. Supplementation comprised 120 mg iron and 500 microg folic acid with or without 4800 RE vitamin A. Their newborn infants were followed up during the first year of life: weight, length, morbidity and food intake were assessed monthly. RESULTS: Infants whose mothers had taken vitamin A supplements during pregnancy had similar weight, length, weight gain and growth as their counterparts during the follow-up period. The proportions of infants with reported symptoms of morbidity were similar in the vitamin A plus iron group and the iron group. In addition immunisation coverage and feeding mode did not differ between the groups. All infants were breast-fed, but exclusive breast-feeding rapidly declined at 4 months of age. Infants with serum retinol concentrations >0.70 micromol/l increased their weight and length more during the first 6 months of life and had higher weight-for-age Z-scores during the first year of life than infants with serum retinol concentrations <or=0.70 micromol/l. Serum retinol concentrations were not associated with morbidity. CONCLUSION: In this study, vitamin A supplementation in conjunction with iron supplementation of pregnant women did not improve growth or reduce morbidity of their infants during the first year of life.

Adult↗
PubMed2002

Determinants of weight and length of Indonesian neonates.

OBJECTIVE: To investigate the determinants of neonatal weight and length. DESIGN: From 16-20 week of pregnancy, 366 mothers of the neonates had participated in the community-based study to investigate the effect of weekly supplementation during pregnancy with iron and vitamin A on infant growth. Women from five villages were allocated randomly to receive two tablets each containing 60 mg iron as ferrous sulphate and 250 micro g folic acid (n=121) or two tablets each containing 2400 RE vitamin A in addition to the same amount of ferrous sulphate and folic acid (n=122). A third ('daily') group (n=123) participating in the national iron supplementation programme was recruited from four neighbouring villages. RESULTS: Neonatal weight and length did not differ between the two weekly groups and between the weekly iron group and the 'daily' group. Iron and vitamin A status during pregnancy did not influence neonatal weight and length significantly. Boys were 100 g heavier and 0.53 cm longer than girls (P<0.05). First born neonates were lighter (P<0.01) and tended to be shorter (P=0.070) than neonates of higher birth order. Maternal age and education as well as other socioeconomic determinants were not associated with neonatal weight and length. Neonatal weight was 32% explained by gestational age, maternal weight, postnatal measurement, gender and parity, while neonatal length was 28% explained by gestational age, maternal weight, postnatal measurement, gender and maternal height. CONCLUSIONS: Gestational age, maternal weight at second trimester and infant gender were the main predictors of neonatal weight and length. SPONSORSHIP: The study was supported by The Netherlands Organization for Scientific Research-Netherlands Foundation for the Advancement of Tropical Research (NWO-WOTRO; WV 93-280) and Neys-van Hoogstraten Foundation (IN 114), The Netherlands, and German Agency for Technical Cooperation (GTZ)/South East Asian Ministers of Education Organization (SEAMEO), Indonesia.

Adolescent↗
PubMed2002

Social aspects of patients with pulmonary tuberculosis in Indonesia.

Tuberculosis (TB) patients have not only medical but also social problems related to their illness, which may influence their motivation for the completion of treatment. This study investigated the social aspects of patients with TB in an urban area of Jakarta, Indonesia. Most TB patients had poor nutritional status and lived in crowded environments. They faced joblessness and negative attitudes from their neighbors and relatives. A few of the patients were afraid that they would not find a partner; others said that their diseases impaired their marriages. We found that patients with a subnormal body mass index restricted their social contact with their family more than patients with a normal body mass index. In general, patients were supported by their families, both financially and socially. Our findings suggest that priority should be given to developing programs aimed at strengthening the family support of TB patients.

Adolescent↗
PubMed2001

Determination of folates in human plasma using hydrophilic interaction chromatography-tandem mass spectrometry.

Folic acid is an essential nutrient, and folate deficiency is associated with a variety of disorders including neural tube defects (during pregnancy) and heart disease. A fast, sensitive, and robust HPLC-tandem mass spectrometry (LC-MS-MS) method was developed for the quantification of free folic acid, tetrahydrofolate, 5'-methyltetrahydrofolate, and 5'-formyltetrahydrofolate in human plasma. Sample preparation required only acetonitrile precipitation of proteins followed by filtration instead of solid-phase extraction or solvent-solvent extraction as in other methods. The rapid and streamlined sample handling procedure minimized degradation of the highly unstable folate species. Hydrophilic interaction chromatography was used for additional sample cleanup on-line, and baseline separation and detection of all four folate species was achieved in less than 30 min. The folate species were detected using negative ion electrospray-tandem mass spectrometry with multiple reaction monitoring of the diagnostic fragment ions of each deprotonated molecule. The predominately organic (hydrophobic) solvent system combined with the microbore flow rate (50 microL/min) used for the chromatography resulted in enhanced electrospray signal response compared to reversed-phase HPLC using a wider bore column. The recovery of all folate species (from spiked plasma) was >97% over a concentration range from 300 pg/L to 12 mg/L with intraday precision (RSD, n = 5) of 3.7-6.5%. Stability studies were carried out for spiked samples in order to define storage and handling conditions. The folic acid limit of quantification (LOQ) in human plasma was 80 pmol/L +/- 10%, and the limit of detection (LOD) was 37.5 pmol/L. The LOQ and LOD for tetrahydrofolate, 5'-methyltetrahydrofolate, and 5'-formyltetrahydrofolate were 1250, 400, and 360 pmol/L of plasma and 425, 165, and 140 pmol/L of plasma, respectively.

Chromatography↗
PubMed2001

Meeting nutrient and energy requirements in old age.

In old age, the complex relation of food consumption with energy and nutrient requirements finds expression in both single and multiple nutritional problems. Addressing conditions affecting intake -- either from foods or from supplements -- endogenous production, bioefficacy and/or requirements can benefit nutritional health in old age through balancing requirements and supply.

Aged↗
PubMed2001

Mild iodine deficiency is associated with elevated hearing thresholds in children in Benin.

OBJECTIVE: Elevated hearing thresholds have been demonstrated in populations afflicted by endemic cretinism as a result of severe iodine deficiency. However, data on the effects of less severe iodine deficiency on hearing thresholds in apparently normal children are scant. This study addresses the question whether there is a relationship among iodine variables, hearing and mental performance in a mildly iodine-deficient population. DESIGN: A randomized, placebo-controlled intervention trial with an observation period of 11 months. SETTING: An iodine-deficient area in northern Benin. SUBJECTS: A total of 197 school children, aged 7-11 y. INTERVENTIONS: A total of 97 children received an oral dose of iodized oil, containing 540 mg I, while 100 children received a placebo. About 3-4 months after supplementation, the whole population began to have access to iodized salt. Non-verbal mental tests were administered and biochemical indicators (thyrotropin, free thyroxine, thyroglobulin and urinary iodine) were measured at the beginning and the end of the study. Hearing was measured at the end of the study in both ears by pure-tone audiometry at seven frequencies. RESULTS: In this mildly iodine-deficient child population children with higher serum thyroglobulin concentrations had significantly higher hearing thresholds in the higher frequency range (> or = 2000 Hz) than children with lower serum thyroglobulin concentration. Moreover children with lower hearing thresholds performed significantly better on the mental tests used. CONCLUSIONS: Even when iodine deficiency is 'mild', promotion of adequate iodine intake through salt iodization programs and other means remains crucial. SPONSORSHIP: Nestlé Foundation, Lausanne, Switzerland; Wageningen University, Wageningen, The Netherlands.

Administration, Oral↗
PubMed2001

Vitamin A and iron supplementation of Indonesian pregnant women benefits vitamin A status of their infants.

Many Indonesian infants have an inadequate nutritional status, which may be due in part to inadequate maternal nutrition during pregnancy. This study was designed to investigate whether infant nutritional status could be improved by maternal vitamin A and Fe supplementation during gestation. Mothers of these infants from five villages had been randomly assigned on an individual basis, supervised and double-blind, to receive supplementation once weekly from approximately 18 weeks of pregnancy until delivery. Supplementation comprised 120 mg Fe and 500 microg folic acid with or without 4800 retinol equivalent vitamin A. Mothers of infants from four other villages who participated in the national Fe and folic acid supplementation programme were also recruited; intake of tablets was not supervised. Anthropometric and biochemical parameters of infants and their mothers were assessed approximately 4 months after delivery. Infants of mothers supplemented with vitamin A plus Fe had higher serum retinol concentrations than infants of mothers supplemented with Fe alone. However, the proportion of infants with serum retinol concentrations <0.70 micromol/l was >70 % in all groups. Maternal and infant serum retinol concentrations were correlated. Fe status, weight and length of infants were similar in all groups. Fe status of girls was better than that of boys, but boys were heavier and longer. We conclude that supplementation with vitamin A in conjunction with Fe supplementation of women during pregnancy benefits vitamin A status of their infants. However, considering the large proportion of infants with marginal serum retinol concentrations, it may still be necessary to increase their vitamin A intake.

Adolescent↗
PubMed2001

Concurrent micronutrient deficiencies in lactating mothers and their infants in Indonesia.

BACKGROUND: Deficiencies of vitamin A, iron, and zinc are prevalent worldwide, affecting vulnerable groups such as lactating women and infants. However, the existence of concurrent deficiencies has received little attention. OBJECTIVE: The aim was to investigate the extent to which deficiencies of vitamin A, iron, and zinc coexist and the nutritional relation between lactating mothers and their infants. DESIGN: In a cross-sectional survey in rural West Java, Indonesia, 155 lactating mothers and their healthy infants were assessed anthropometrically and blood, urine, and breast-milk samples were obtained. RESULTS: Marginal vitamin A deficiency was found in 54% of the infants and 18% of the mothers. More than 50% of the mothers and infants were anemic and 17% of the infants and 25% of the mothers were zinc deficient. There was a strong interrelation between the micronutrient status of the mothers and infants and the concentrations of retinol and beta-carotene in breast milk. Vitamin A deficiency in infants led to an increased risk of anemia and zinc deficiency (odds ratios: 2.5 and 2.9, respectively), whereas in mothers the risk of anemia and iron deficiency (odds ratios: 3.8 and 4.8, respectively) increased. In infants, concentrations of insulin-like growth factor I were related to concentrations of plasma retinol and beta-carotene but not to zinc. CONCLUSIONS: Micronutrient deficiencies were prevalent in West Java. The micronutrient status of lactating mothers and that of their infants were closely related; breast milk was a key connecting factor for vitamin A status. Furthermore, concurrent micronutrient deficiencies appeared to be the norm.

Adolescent↗
PubMed2001

Bioefficacy of beta-carotene dissolved in oil studied in children in Indonesia.

BACKGROUND: More information on the bioefficacy of carotenoids in foods ingested by humans is needed. OBJECTIVE: We aimed to measure the time required for isotopic enrichment of beta-carotene and retinol in serum to reach a plateau, the extent of conversion of beta-carotene dissolved in oil with use of beta-carotene and retinol specifically labeled with 10 (13)C atoms, and the intraindividual variation in response. DESIGN: Indonesian children aged 8--11 y (n = 35) consumed 2 capsules/d, 7 d/wk, for < or =10 wk. Each capsule contained 80 microg [12,13,14,15,20,12',13',14',15',20'-(13)C(10)]beta-carotene and 80 microg [8,9,10,11,12,13,14,15,19,20-(13)C(10)]retinyl palmitate. Three blood samples were drawn per child over a period of < or =10 wk. HPLC coupled with atmospheric pressure chemical ionization liquid chromatography-mass spectrometry was used to measure the isotopic enrichment in serum of retinol with [(13)C(5)]retinol and [(13)C(10)]retinol and of beta-carotene with [(13)C(10)]beta-carotene. The beta-carotene in the capsules used had a cis-trans ratio of 3:1. RESULTS: Plateau isotopic enrichment was reached by day 21. The amount of beta-carotene in oil required to form 1 microg retinol was 2.4 microg (95% CI: 2.1, 2.7). The amount of all-trans-beta-carotene required to form 1 microg retinol may be lower. CONCLUSIONS: The efficiency of conversion of this beta-carotene in oil was 27% better than that estimated previously (1.0 microg retinol from 3.3 microg beta-carotene with an unknown cis-trans ratio). The method described can be extended to measure the bioefficacy of carotenoids in foods with high precision, requiring fewer subjects than other methods.

Biotransformation↗