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Search Results: 1 - 10 of 52395 matches for " vitamin A "
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Vitamin A, Vitamin E, Lutein and β-Carotene in Lung Tissues from Subjects with Chronic Obstructive Pulmonary Disease and Emphysema  [PDF]
Michael W. Sch?ffer, Somdutta Sinha Roy, Shyamali Mukherjee, Salil K. Das
Open Journal of Respiratory Diseases (OJRD) , 2013, DOI: 10.4236/ojrd.2013.32008
Abstract: Vitamin A (VA) and its active metabolites play an essential role in lung airway function. Patients with moderate to severe chronic obstructive pulmonary disease (COPD) have a lower serum retinol concentration, and improvement of their 1-second Forced Expiratory Volume (FEV1) is achieved with VA supplementation. In order to test our hypothesis that the VA signaling pathway is compromised in COPD, we obtained 20 lung samples from COPD patients differing in the degree of emphysema as judged by their FEV% values. All were smokers or were exposed to secondhand smoke. Levels of VA (retinol/retinyl ester), tocopherols and carotenoids (lutein, beta-carotene) in these samples were determined using HPLC. Additional analytes beside VA were included for their known roles as antioxidants and modulators of VA-action. VA levels (retinol/retinyl ester) decreased significantly with the increase in severity of emphysema. Among other analytes, α-tocopherol levels fell by 25.8% in the severe emphysema group in comparison to the mild emphysema group, and lutein levels similarly decreased in severe compared to moderate emphysema groups. However, beta-carotene levels remained unchanged. Thus there is a significant linear correlation between lung VA-levels and the severity of emphysema. There was also a significant reduction in the levels of α-, δ-tocopherol and lutein in the severe emphysema group of COPD patients who either smoked or were exposed to smoke.
Aspectos Farmacológicos relevantes de las Vitaminas Antioxidantes (E, A y C)
Torres,M; Márquez,M; Sutil de Naranjo,R; de Yépez,C; Leal de García,M; Mu?oz,M; Gómez,ME;
Archivos Venezolanos de Farmacología y Terapéutica , 2002,
Abstract: abstract a balanced nutrition, where is contemplated an adequate intake of fats and four or more rations of fruits and vegetables is a way to provide to the organism of vitamins, such as vitamins e, a and c. those are considered, antioxidants vitamins, attributing them an important role in prevention of pathologies, where free radicals are involved, like infections, cardio -circulatory chronic and degenerative diseases, cancer, aging etc. for this reason, who has established that a optimal plasma status of essentials antioxidants is a prerequisite of health and would decrease the risk of develop chronic diseases. therefore, a adequate information about their dietetic sources, requeriments, pharmacokinetic and toxicity are necessary for the rational use of this vitamins.
Aspectos básicos y determinación de las vitaminas antioxidantes E
Márquez,Mercedes; Yépez,Carmen E; Sútil-Naranjo,Rosalía; Rincón,Manuel;
Investigación Clínica , 2002,
Abstract: vitamin e usually works as a biological antioxidant, preventing the oxidation of poliunsaturated fatty acids and proteins, for which it is considered an important protective factor in the development of diseases related to oxidative processes. beyond its antioxidant properties, it has been involved also in genetic expression, mitochondrial metabolism, cell differentiation and immune system regulation. from the point of view of its antioxidant protection properties, values 3 1200-1300 μg/dl are considered optimum levels (standardized according to plasmatic lipid levels). in relation to the beneficial advantage effects of vitamin e on primary or secondary atherosclerotic disease, data are not conclusive. vitamin a is part of the organism′s defense barrier against free radicals. its antioxidant mechanism of action includes scavenging of singlet oxygen and thiol free radicals, and it also could be related to processes that involve genetic expression and cell differentiation. as an antioxidant, vitamin a plasmatic levels 3 80 μg/dl are considered optimal. the highest risk of using this vitamin is related to its acute or chronic toxicity. quantification of serum vitamin e (alpha tocopherol) and vitamin a (retinol) are made by high performance liquid chromatography (hplc), method of high precision, sensitivity and reproducibility
Estudo da varia??o do pH da pele humana exposta à formula??o cosmética acrescida ou n?o das vitaminas A, E ou de ceramida, por metodologia n?o invasiva
Leonardi, Gislaine Ricci;Gaspar, Lorena Rigo;Campos, Patrícia M. B. G. Maia;
Anais Brasileiros de Dermatologia , 2002, DOI: 10.1590/S0365-05962002000500006
Abstract: background: moisturizers are believed to improve the skin's condition by increasing the water content of the stratum corneum. vitamins a and e and ceramides have been widely used in cosmetic moisturizing products, and these are one of the most important cosmetic and body care products. objective: the aim of this research was to evaluate the effects on the ph of human skin of an o/w emulsion (non ionic self-emulsifying base) with and without vitamin a palmitate, or vitamin e acetate, or ceramide iii, using a non-invasive method. method: the investigations were carried out on a group of 40 healthy female test subjects aged between 30 and 45 years old, using the skin ph meter ph 900 pc. the measurements were performed on the forearm of volunteers at 7 and 30 days after daily use (twice a day) of the products used in the study. results and conclusion: the presence of vitamins a or e or ceramide iii did not change the ph of the skin, consequently the formulations studied are suitable for cosmetic usage.
VITAMINS A AND E AS ANTIOXIDANTS
Jasmina Tomin,Vladmila Bojani?,Marko Jevri?,Jelena ?ivanov-?urlis
Acta Medica Medianae , 2004,
Abstract: Vitamin A is involved in metabolism of proteins, lipids and carbohydrates. It affects tissue respiration and energetic metabolism. The speed of oxidation process of citric acid cycle and process of oxidative phosphorilation are influenced by vitamin A. Anticarcinogenic effect of vitamin A is believed to exist due to β-karoten, which exerts antioxidative properties.Vitamin E proved to be effective in preventing lipid peroxidation and other radical driven oxidative events. Vitamin E acts mainly by being incorporated into cell membranes, thereby protecting them against free radical attack in the lipid phase, especially the lipoperoxyl radical, but also against O2 , singlet oxygen and OH. The antioxidant activity of vitamin E has persuaded many groups to study its ability to prevent chronic disease, especially those believed to have an oxidative stress component such as cardiovascular diseases, atherosclerosis, and cancer.
Determination of Major Carotenoids in Processed Tropical Leafy Vegetables Indigenous to Africa  [PDF]
Viviane Nkonga Djuikwo Djuikwo, Richard Aba Ejoh, Inocent Gouado, Carl Moses Mbofung, Sherry A. Tanumihardjo
Food and Nutrition Sciences (FNS) , 2011, DOI: 10.4236/fns.2011.28109
Abstract: Tropical leafy-vegetables (n = 21) indigenous to Cameroon, Africa, were collected, processed, and analyzed for carotenoids by HPLC. The processing techniques used were oven drying; sun-drying; squeeze-washing and boiling; and a combination of boiling in alkaline salt and squeeze-washing. Carotenoids included lutein, α-carotene, zeaxanthin, β-cryptoxanthin, and β-carotene (all-trans, 13-cis, and 9-cis), which varied by species (P < 0.001). With the exception of P. purpureum and H. sabdarifa, lutein and β-carotene were the predominant carotenoids. In the oven dried vegetables, β-carotene was between 15% and 30% of total carotenoids and the values ranged from 7.46 ± 0.04 in T. indica to 39.86 ± 2.32 mg/100 g DW in V. oleifera. Lutein concentrations for these leafy vegetables ranged from 11.87 ± 0.7 in H. sabdarifa to 75.0 ± 3.6 mg/100 g DW in V. colorata and made up > 40% of total carotenoids. Traditional preparation and processing procedures led to significant losses of carotenoids and β-carotene was most affected during sun-drying with a maximum of 73.8% loss observed in A. acanthochiton.
Prevalência de deficiência de vitamina A e fatores associados em pré-escolares de Teresina, Piauí, Brasil
Paiva, Adriana de Azevedo;Rondó, Patrícia Helen de Carvalho;Gon?alves-Carvalho, Cecília Maria Resende;Illison, Vanessa Kristinne;Pereira, Joilane Alves;Vaz-de-Lima, Lourdes Rehder Andrade;Oliveira, Carmem Aparecida de;Ueda, Mirthes;Bergamaschi, Denise Pimentel;
Cadernos de Saúde Pública , 2006, DOI: 10.1590/S0102-311X2006000900029
Abstract: vitamin a deficiency is a public health problem in the northeast of brazil. this study aimed to determine the prevalence of vitamin a deficiency and associated factors among preschool children in teresina, piauí, brazil. we studied the serum retinol levels and socioeconomic and demographic characteristics of 631 children from 36 to 83 months of age. the statistical association between each of the above characteristics and serum retinol levels was investigated by univariate and multivariate linear regression analysis. mean serum retinol was 1.21mmol/l (95%ci: 1.17-1.25μmol/l) and was independent of gender (p = 0.259). prevalence of vitamin a deficiency (retinol < 0.69μmol/l) was 15.4% (95%ci: 12.7-18.4), with a tendency to decrease with age. acceptable but not adequate retinol levels (0.70 to 1.04μmol/l) were observed in 29% of children (95%ci: 25.2-32.4). there were positive associations between retinol levels and age, income, vitamin a supplementation, and maternal schooling. vitamin a deficiency appeared as a moderately serious public health problem, emphasizing the importance of strategies to combat this problem in the region.
Teratogenia da vitamina A
Chagas, Maria Helena de Castro;Flores, Hernando;Campos, Florisbela de Arruda Camara e Siqueira;Santana, Raquel Araújo de;Lins, Erika Chagas Barreto;
Revista Brasileira de Saúde Materno Infantil , 2003, DOI: 10.1590/S1519-38292003000300003
Abstract: the vitamin a is essential to the preservation and the normal functioning of tissues, as well as, to the growth and development. in the human being it has indirect evidence that the vitamin a in excess, during the first weeks of gestation is teratogenic. of the opposite, it does not have doubts on the deleterious effect, of a devoid feeding in this micronutrient and on the availability of the knowledge technician to prevent them. the concern with the fact of that the vitamin a would lead it the teratogenicity in human beings, has delayed the implementation of combat programs the vitamin a lack, mainly reaching the programs of food enrichment. literature is controverted and makes use of few information on the doses for supplementation of pregnant. as retinol circulating maternal is controlled homeostatic after the food consumption vitamin source, it expects after same metabolic reply the strengthened food consumption, indicating that it does not have teratogenicity risk. consequently, highly seems improbable that the consumption of enriched foods or vitamin supplements the daily pay-formed one, in habitual the single doses, has teratogenic effect in the man.
Prevalência de anemia e hipovitaminose A em puérperas do Centro de Aten??o à Mulher do Instituto Materno Infantil Prof. Fernando Figueira, IMIP: um estudo piloto
Lopes, Renan éboli;Ramos, Karla da Silva;Bressani, Cristiane Campello;Arruda, Ilma Kruse de;Souza, Ariani Impieri de;
Revista Brasileira de Saúde Materno Infantil , 2006, DOI: 10.1590/S1519-38292006000500009
Abstract: objectives: this study assessed anemia and hypovitaminosis a in puerperal women seen at the instituto materno infantil prof. fernando figueira - imip. methods: descriptive cross sectional study using a sample of 72 puerperal hospital discharged women. results: age ranged from 12 to 41 years old, median age of 22.5 years old. a good school level was noted, although seven of these women declared three years or less of education. some type of iron supplement intake during pregnancy was informed by 48 women. it was noted that 43.1% showed hemoglobin concentration below 10,0 g/dl and 65.3% below 11,0 g/dl. microcitosis occurred in 14 patients (19.4%) with no microcitosis case. the levels of hypovitaminosis a were high: 25.0% had retinol levels under 20 μg/dl. an association tendency between puerperal non-anemic women and normocitosis (median corpuscular weight x anemia) was present; with a cut-off point for anemia of 11,0 g/dl, a positive association between anemia during pregnancy and the use of iron supplements was noted. conclusions: anemia prevalence was high, although microcitosis frequency was low. prevalence of hypovitaminosis a was high reaching levels considered a public health issue in brazil.
Dietary Intake of Vitamin A and Macronutrients among Pregnant Women in Ngaoundere Town, Adamawa Region, Cameroon  [PDF]
Damndja Wilfred Ngaha, Edith N. Fombang, Richard Aba Ejoh
Food and Nutrition Sciences (FNS) , 2014, DOI: 10.4236/fns.2014.521219
Abstract: This paper examines the risk of Vitamin A deficiency among selected pregnant women in Ngaoundere, Adamawa Region, Cameroon. A total of one hundred (100) pregnant women attending ante natal visits at the Regional Hospital in Ngaoundere were involved in a survey conducted in 2012 which used a 24-hour dietary recall to assess their dietary intake. Food models were used to assist memory and portion sizes of food taken. Carotenoids were quantified in the meals commonly consumed, as well as proteins, sugar, fibers and oil, nutrients intervening in carotenoids absorption and vitamin A metabolism. The results indicated that the dietary intake of vitamin A was inadequate with 37.5% of the selected pregnant women exposed to acute vitamin A deficiency, while 20% of them were exposed to the severe form. The daily consumption of vitamin A was about 539.09 ± 43.09 μg, corresponding to a contribution of 67.39% to the vitamin A requirement of the pregnant women. The dietary intake of macronutrients was also inadequate with a daily consumption of 57.28 ± 12 g for oils, 177.88 ± 29 g for sugars, 47.34 ± 11 g for proteins and 11.28 ± 3 g for fibers corresponding respectively to a contribution of 63.6%, 70.8%, 78.90% and 45.1% of these nutrients requirement in these women. Given that over 50% of the women surveyed were exposed to vitamin A deficiency, there is a need for urgent intervention programs in the area to alleviate this situation.
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