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Showing 121 to 126 of 126 (0.039 seconds)Spelling suggestions: "subject:"vitamin B6."" "subject:"citamin B6.""
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Electronic Modulation in Pyridoxal-5’-Phosphate-Dependent EnzymesDajnowicz, Steven January 2018 (has links)
No description available.
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Evaluation of vitamin B-6 status of Saudi adult males in the Riyadh region - Saudi ArabiaAl-Assaf, Abdullah 11 August 2003 (has links)
The aim of this study was to investigate the vitamin B-6 status of Saudi adult
males and compare the status between rural and urban subjects. Fifty-one adult male
subjects were recruited from urban (n=31) and rural (n=20) populations of Riyadh.
These subjects were reclassified to cigarette smokers (n=19), water pipe smokers
(n=5) and non-smokers (n=27). The study also investigated the intake of
macronutrients and selected micronutrients. In addition, the study investigated other
health indicators including Body Mass Index (BMI), hematocrit, hemoglobin, plasma
alkaline phosphatase activity and albumin concentration, urinary creatinine and urea
nitrogen excretion.
The mean of vitamin B-6 intake, B-6 to protein ratio, plasma pyridoxal phosphate
(PLP) concentration and urinary 4-PA excretion in urban group were 2.18 ± 0.62
mg/day, 0.022 ± 0.008 mg/g, 39.3 ± 18.0 nmol/L and 4.6 ± 2.3 μmol/day, respectively. In rural group, these measures were 2.15 ± 0.65 mg/day, 0.021 ± 0.004 mg/g, 40.5 ± 14.6 nmol/L and 4.4 ± 2.3 (μmol/day, respectively. These measures indicated adequate
status with no significant difference between the two groups. The mean intake of
calcium, folate, vitamin D, zinc and dietary fiber was lower than recommendation of
the Dietary Reference Intakes (DRI) in both groups. Health indicators were within
normal range except for BMI, which indicated a prevalence of overweight and obesity
in both urban (27.1 ± 5.5 Kg/m²) and rural (28.2 ± 6.0 Kg/m²) subjects.
Comparison of the three smoking groups showed that the water pipe smokers
compared to cigarette smokers and non-smokers groups had significantly higher mean
intake of vitamin B-6 (2.51 ± 0.73 mg/day), which resulted in higher concentrations of
plasma PLP, pyridoxal (PL), red blood cells PLP and urinary 4-PA (54.9 ± 23.1
nmol/L, 21.5 ± 10.0 nmol/L, 33.7 ± 8.5 nmol/L and 6.9 ± 4.7 μmol/day, respectively).
Cigarette smokers had significantly lower concentration of plasma PLP (30.9 ± 12.5
nmol/L) compared to non-smokers (40.0 ± 12.9 nmol/L) without a significant
difference in vitamin B-6 intake. Hematocrit and hemoglobin were significantly higher
in smokers (50 ± 3% and 167 ± 11 g/L, respectively) compared to non-smokers (48 ±
3% and 160 ± 9 g/L, respectively). The results of this study suggest that vitamin B-6
status of adult males in Riyadh is adequate with no urban vs. rural variation. / Graduation date: 2004
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| 123 |
Vitaminas do complexo B e ferro em farinhas de cereais / Complex B vitamins and iron in cereal flourPresoto, Ana Elisa Ferreira 27 November 2006 (has links)
As vitaminas do complexo B e o ferro estão presentes em farinhas de cereais, alimentos amplamente consumidos pela população brasileira. O teor natural desses compostos em farinhas de cereais pode ser significativo no cálculo de uma dieta bem balanceada e o consumo de produtos industrializados enriquecidos com vitaminas do complexo B e ferro ajuda a contribuir na ingestão diária recomendada desses micronutrientes. Tabelas Mundiais de Composição de Alimentos apresentam dados incompletos das vitaminas do complexo B e do ferro em farinhas de cereais. No Brasil, a adição de ácido fólico e ferro em farinhas de milho e trigo produzidas para fins industriais é obrigatória desde 2002. Deste modo, para a adequação dos teores de rotulagem de produtos enriquecidos com vitaminas e ferro se fazem necessários o desenvolvimento e a validação de metodologias analíticas confiáveis e sensíveis para análise de vitaminas do complexo B e ferro em alimentos que apresentam tais micronutrientes em quantidades baixas, porém significativas, que correspondem aos teores naturalmente presentes. O objetivo do presente trabalho é a avaliação dos teores de sete vitaminas do complexo B (B1, B2, B6, ácido pantotênico, ácido fólico, niacina e biotina) e ferro em cinco farinhas de cereais (aveia, arroz, cevada, milho e trigo) utilizadas como matéria prima de produtos enriquecidos na indústria alimentícia, utilizando métodos validados. / Complex B vitamins and iron are present in some cereal foods, a kind of food largely consumed by Brazilian people. The total of these micronutrients can be significant at the dairy ingestion portion and in the consume of industrialized products enriched with complex B vitamins and iron contribute in the recommended dietary intake of these micronutrients. Table of food composition do not report complete data of complex B vitamins and iron in cereal flours. In Brazil, since 2002 the addition of folic acid and iron in com and wheat flours is compulsory. Therefore, to adapt the label of some products enriched with vitamins and iron, there is necessary the development and validation of analytical methods. These methods must be reliable and with enough sensitivity to analyse complex B vitamins and iron, in low concentration, wich are natural content in food. The purpose of this work is the evaluation, with validated methods, of the content of seven complex B vitamíns (B1, B2, B6, niacin, folic acid, pantothenic acid and biotin) and iron in five kinds of cereal flours (oat, rice, barley, com and wheat). These raw materiais are used in food industry in order to enrich the industrialized products.
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| 124 |
The effects of long-term homocysteine-lowering treatment with folic acid, vitamin B6 and Vitamin B12 on vascular structure and function in strokePotter, Kathleen January 2009 (has links)
[Truncated abstract] An elevated total plasma homocysteine concentration (tHcy) is associated with an increased risk of myocardial infarction and ischemic stroke. Folic acid, vitamin B6 and B12 supplements significantly reduce tHcy even in people who are not overtly vitamin deficient. If homocysteine is a causal risk factor for atherothrombotic events, treatment with B-vitamins might prove a simple and cost-effective means to reduce cardiovascular risk. However, it remains unclear whether elevated tHcy causes atherosclerosis or is simply a risk marker. To prove that homocysteine is a modifiable risk factor for cardiovascular disease it is necessary to show that lowering tHcy reduces vascular risk. The aim of this study was to determine whether long-term homocysteine-lowering with B-vitamins would improve vascular structure and function in people with a history of stroke. This study was a cross-sectional sub-study of the Vitamins TO Prevent Stroke trial (VITATOPS), a multi-centre, randomised, double-blind, placebo-controlled clinical trial designed to test the efficacy and safety of B-vitamins (folic acid 2mg, vitamin B6 25mg and vitamin B12 0.5mg) in the prevention of vascular events in patients with a recent history of stroke or transient ischemic attack. 173 VITATOPS participants were recruited for the current study. Age, sex, stroke type, medications, cardiovascular risk factors and smoking history were recorded and blood pressure, height, weight, waist and hip girth were measured in all subjects at least two years after randomisation. ... After a mean treatment period of 3.9 ± 0.9 years, the subjects randomised to vitamin treatment had significantly lower tHcy than the subjects randomised to placebo (7.9mol/L, 95%CI 7.5, 8.4 versus 11.8mol/L, 95%CI 10.9, 12.8; p<0.001). There were no significant differences between groups in CIMT (0.84 ± 0.17mm vitamins versus 0.83 ± 0.18mm placebo; p=0.74) or FMD (median of 4.0%, IQR 0.9, 7.2, vitamins versus 3.0%, IQR 0.6, 6.6 placebo; p=0.48). Pooled estimates from the meta-analyses showed that B-vitamin treatment reduces CIMT by 0.10mm (95%CI 0.20, -0.01mm) and increases FMD by 1.4%, (95%CI 0.7, 2.2), although these estimates may have been influenced by positive publication bias. The improvement in FMD was significant in studies of less than eight weeks duration but not in studies with longer treatment periods. The association between tHcy and CIMT and FMD was eliminated by adjustment for renal function and long-term B-vitamin treatment did not alter the strong linear relationship between tHcy and cystatin C. Lowering tHcy did not alter arterial wall inflammation assessed by 18FDG-PET, although small subject numbers meant we were unable to exclude a minor treatment effect. Long-term homocysteine-lowering with B-vitamin treatment did not improve CIMT or FMD or reduce arterial wall inflammation in people with a history of stroke. The relationship between tHcy and these markers of vascular risk was eliminated by adjustment for renal function. Our data are consistent with the hypothesis that elevated tHcy is a risk marker for cardiovascular disease rather than a modifiable causal risk factor.
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Vitaminas do complexo B e ferro em farinhas de cereais / Complex B vitamins and iron in cereal flourAna Elisa Ferreira Presoto 27 November 2006 (has links)
As vitaminas do complexo B e o ferro estão presentes em farinhas de cereais, alimentos amplamente consumidos pela população brasileira. O teor natural desses compostos em farinhas de cereais pode ser significativo no cálculo de uma dieta bem balanceada e o consumo de produtos industrializados enriquecidos com vitaminas do complexo B e ferro ajuda a contribuir na ingestão diária recomendada desses micronutrientes. Tabelas Mundiais de Composição de Alimentos apresentam dados incompletos das vitaminas do complexo B e do ferro em farinhas de cereais. No Brasil, a adição de ácido fólico e ferro em farinhas de milho e trigo produzidas para fins industriais é obrigatória desde 2002. Deste modo, para a adequação dos teores de rotulagem de produtos enriquecidos com vitaminas e ferro se fazem necessários o desenvolvimento e a validação de metodologias analíticas confiáveis e sensíveis para análise de vitaminas do complexo B e ferro em alimentos que apresentam tais micronutrientes em quantidades baixas, porém significativas, que correspondem aos teores naturalmente presentes. O objetivo do presente trabalho é a avaliação dos teores de sete vitaminas do complexo B (B1, B2, B6, ácido pantotênico, ácido fólico, niacina e biotina) e ferro em cinco farinhas de cereais (aveia, arroz, cevada, milho e trigo) utilizadas como matéria prima de produtos enriquecidos na indústria alimentícia, utilizando métodos validados. / Complex B vitamins and iron are present in some cereal foods, a kind of food largely consumed by Brazilian people. The total of these micronutrients can be significant at the dairy ingestion portion and in the consume of industrialized products enriched with complex B vitamins and iron contribute in the recommended dietary intake of these micronutrients. Table of food composition do not report complete data of complex B vitamins and iron in cereal flours. In Brazil, since 2002 the addition of folic acid and iron in com and wheat flours is compulsory. Therefore, to adapt the label of some products enriched with vitamins and iron, there is necessary the development and validation of analytical methods. These methods must be reliable and with enough sensitivity to analyse complex B vitamins and iron, in low concentration, wich are natural content in food. The purpose of this work is the evaluation, with validated methods, of the content of seven complex B vitamíns (B1, B2, B6, niacin, folic acid, pantothenic acid and biotin) and iron in five kinds of cereal flours (oat, rice, barley, com and wheat). These raw materiais are used in food industry in order to enrich the industrialized products.
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| 126 |
Investigating the porphyrias through analysis of biochemical pathways.Ruegg, Evonne Teresa Nicole January 2014 (has links)
ABSTRACT
The porphyrias are a diverse group of metabolic disorders arising from diminished
activity of enzymes in the heme biosynthetic pathway. They can present with acute
neurovisceral symptoms, cutaneous symptoms, or both. The complexity of these
disorders is demonstrated by the fact that some acute porphyria patients with the
underlying genetic defect(s) are latent and asymptomatic while others present with
severe symptoms. This indicates that there is at least one other risk factor required in
addition to the genetic defect for symptom manifestation. A systematic review of the
heme biosynthetic pathway highlighted the involvement of a number of micronutrient
cofactors. An exhaustive review of the medical literature uncovered numerous reports
of micronutrient deficiencies in the porphyrias as well as successful case reports of
treatments with micronutrients. Many micronutrient deficiencies present with
symptoms similar to those in porphyria, in particular vitamin B6. It is hypothesized
that a vitamin B6 deficiency and related micronutrient deficiencies may play a major
role in the pathogenesis of the acute porphyrias. In order to further investigate the
porphyrias, a computational model of the heme biosynthetic pathway was developed
based on kinetic parameters derived from a careful analysis of the literature. This
model demonstrated aspects of normal heme biosynthesis and illustrated some of the
disordered biochemistry of acute intermittent porphyria (AIP). The testing of this
model highlighted the modifications necessary to develop a more comprehensive
model with the potential to investigated hypotheses of the disordered biochemistry of
the porphyrias as well as the discovery of new methods of treatment and symptom
control. It is concluded that vitamin B6 deficiency might be the risk factor necessary
in conjunction with the genetic defect to trigger porphyria symptoms.
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