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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
531

The effect of vitamin D2, vitamin D3 or vitamin D2 in mushroom powder supplements on broad gene expression in human white blood cells

Feigert, Caroline Elizabeth 22 January 2016 (has links)
Sufficient vitamin D is important for overall health. However, cutaneous production of vitamin D is limited by season and little vitamin D naturally occurs in food. Therefore, vitamin D supplementation is necessary. Vitamin D is available in pharmacies as vitamin D2 and vitamin D3, and can also be obtained by irradiating mushrooms to produce vitamin D2. Types of vitamin D supplementation were tested to compare their ability to increase vitamin D status and their effect on broad gene expression in human white blood cells. 2000 IU of vitamin D2, vitamin D3 or vitamin D2 in irradiated mushroom powder were given to subjects daily for twelve weeks. A placebo mushroom powder group was included in the second half of the study. To determine the effect of different supplementation on vitamin D status, whole blood was obtained weekly and serum was assayed for 25(OH)D2 and 25(OH)D3. Change in total 25(OH)D was determined from baseline to twelve weeks; 25(OH)D levels in the placebo mushroom powder group did not change significantly at 1.8 ± 1.8 ng/ml (9.6 ± 9.6%), the mushroom D2 group increased by 10.9 ± 10.2 ng/ml (53.2 ± 49.8%), the supplemental D2 group increased by 11.8 ± 7.4 ng/ml (60.2 ± 37.8%) and the supplemental D3 group increased by 21.7 ± 8.9 ng/ml (114.2 ± 46.8%). As expected, the total active form of vitamin D (1,25-dihydroxyvitamin D) showed no change in all groups because of its tight regulation. To determine the potential influence of vitamin D supplementation on differential gene expression in the immune system, white blood cells were isolated from whole blood samples taken before and after supplementation. RNA was extracted, and microarray assays were performed. Gene Set Enrichment Analysis was completed to determine strongly influenced pathways. However, due to the numerous variables between halves of the study, gene expression data was treated as separate studies. Even so, pathways involving RNA activation and degradation were significant between mushroom powder and mushroom D2 supplementation in both halves of the study, indicating the influence of compounds in mushrooms on RNA metabolism pathways. Supplemental vitamin D2 affected gene expression, though only two pathways showed significant change. Supplemental vitamin D3 was found to influence pathways involved in replication, transcription, and translation in both halves of the study. In conclusion, mushrooms powder, mushroom vitamin D2, supplemental vitamin D2, and supplemental vitamin D3 all influence differential gene expression in human white blood cells.
532

Analys av 25-hydroxyvitamin D i primärvården

Börjesson, Emma January 2015 (has links)
Background: The interest of vitamin D has increased in the last years. That is because there is so many possible positive effects of vitamin D and also because many individuals has vitamin D deficiency. Modern man spends much time indoors which leads to lower levels of vitamin D. People who have emigrated from a sunny climate to a Nordic climate often gets a deficiency due to a more pigmented skin which requires a larger amount of UVB to get an adequate synthesis of vitamin D. Aim: The aim with this study is to compare and evaluate how similar the instrument mini VIDAS measures 25(OH)D total against the current existing method cobas e 602. A discussion about if 25(OH)D total has a place in primary health care is included in the study. Method: The comparison was based on 39 samples. The samples was analyzed on cobas e 602 and mini VIDAS. A precision test was performed. External controls from DEQAS was also included in the study. The results have been presented with simple linear regression analysis, mean value, SD and CV. Results: The comparison between cobas e 602 and mini VIDAS gave a coefficient of determination of 81,34 %. mini VIDAS was closest to the external controls target values. Conclusion: There is no obvious conclusions about if mini VIDAS fulfills the requirement to be introduced to primary health care. The coefficient of determination of 81,34 % should be at least 95 %. However is mini VIDAS closer to the external controls target values then cobas e 602. There is factors that implies that 25(OH)D total has a place in primary health care with regards to demand, use and because many individuals has vitamin D deficiency. The instrument is also user-friendly to a primary health care laboratory. / Bakgrund: Intresset för vitamin D har ökat de senare åren. Det beror dels på att det finns många eventuella positiva effekter av vitamin D och dels på att många individer har brist på vitamin D. Nutidens människa spenderar mycket tid inomhus vilket leder till lägre nivåer av vitamin D. Personer som har utvandrat från ett soligt klimat till nordiskt klimat får ofta brist på grund av en mer pigmenterad hud som behöver större mängd UVB för att få en adekvat syntes av vitamin D. Syfte: Syftet med den här studien är att jämföra och utvärdera hur lika det patientnära instrumentet mini VIDAS mäter 25(OH)D total mot befintlig metod cobas e 602. Diskussion om analysen 25(OH)D total har en plats i primärvården ingår även i studien. Metod: Jämförelsen baserades på 39 st prover. Proven analyserades på cobas e 602 och mini VIDAS. Ett precisionsförsök gjordes. Externkontroller från DEQAS inkluderades även i studien. Resultaten har presenterats genom enkel linjär regressionsanalys, medelvärde, SD och CV. Resultat: Jämförelsen mellan cobas e 602 och mini VIDAS gav en förklaringsgrad på 81,43 %. mini VIDAS var närmst externkontrollernas målvärden. Slutsats: Det går inte att dra självklara slutsatser ifall mini VIDAS uppfyller kraven att införas i primärvården. Förklaringsgraden som är på 81,43 % bör vara minst 95 %. Däremot överensstämmer mini VIDAS med externkontrollerna bättre än cobas e 602. Det finns faktorer som tyder på att analysen 25(OH)D har en plats i primärvården med avseende på efterfrågan, användningsområde och antal individer med brist. Instrumentet är dessutom användarvänligt för ett primärvårdslaboratorium.
533

Postnatal vitamin D supplementation normalizes neonatal bone mass following maternal dietary vitamin D deficiency in the guinea pig

Finch, Sarah L. January 2007 (has links)
Since vitamin D deficiency is common at birth, the objective of this study was to test if postnatal vitamin D supplementation would normalize bone mineralization. Forty guinea pigs were randomized to receive a diet with or without vitamin D3 during pregnancy. Newborn pups were randomized to receive 10 IU of vitamin D3 or a placebo daily until d28. Measurements at birth and d28 included whole body and regional bone mass, osteocalcin and deoxypyridinoline, plus biomechanical testing of excised tibias and femurs. Offspring from deficient sows had lower body weight, whole body and tibia bone mineral content (BMC) and lower osteocalcin and biomechanical integrity. By d28 this group had lower whole body bone density and femur BMC, unless supplemented. Interactions with gender showed males continued to have low 25(OH)D despite supplementation. Therefore, neonates born to sows with dietary vitamin D deficiency require supplemental vitamin D to support normal bone mineral accretion.
534

Vitamin E and atherosclerosis : investigation of novel biological activities and metabolism of gamma-tocopherol in humans

Wu, Jason H. Y January 2006 (has links)
[Truncated abstract] Current understanding of atherosclerosis suggests that it is a chronic inflammatory disease, and that increased oxidative stress may be an important pathological event contributing to the disease process. There has been interest in the ability of dietary derived nutrients such as vitamin E, to act as antioxidants and protect against atherosclerosis. Despite promising epidemiological data which suggested benefits from a higher intake of &alpha-tocopherol (&alphaT), one of the major forms of dietary vitamin E, for protection against atherosclerosis, large scale, randomised controlled trials have generally shown no protective effect of high dose &alphaT supplementation. Recent studies suggest that the other major dietary tocopherol isomer, &gamma-tocopherol (&gammaT), may possess biological activities not shared by &alphaT. Supplementation with &gammaT, or mixtures of tocopherols rich in &gammaT, have shown biological activities that may help protect against atherosclerosis. The aim of this PhD project is to further characterise the biological relevance of ?T for protection against CVD... Both ?- and mixed tocopherol supplementation resulted in reduced plasma F2-isoprostanes (P < 0.001 and P = 0.001, respectively) but did not affect 24 hour urinary F2-isoprostanes and erythrocyte antioxidant enzyme activities. Neither &alphaT nor mixed tocopherol supplementation affected any measured plasma markers of inflammation. The tocopherol supplementation also did not affect COX-2 activity as assessed by 14 stimulated whole blood prostaglandin E2 synthesis, and urinary prostacyclin metabolite output. Compared to the placebo group, stimulated neutrophil leukotriene B4 (LTB4) production decreased significantly in the mixed tocopherol group (P=0.02) but not in the &alphaT group (P=0.15). The ability of both pure &alphaT and mixed tocopherol supplementation to reduce systemic lipid peroxidation in patients with type 2 diabetes, suggests potential benefits of vitamin E supplementation in this population. However, despite decreasing oxidative stress, our results also suggests that in populations with well controlled type 2 diabetes, supplementation with either &alphaT, or mixed tocopherol rich in &gammaT, is unlikely to confer further benefits in reducing systemic inflammation. Future research into the possible unique biological activity of different tocopherol isomers other than &alphaT, for example, their ability to affect the 5-LO pathway and production of inflammatory mediators such as LTB4, is warranted.
535

Vitamin D status as a predictor of outcomes of experimentally-induced muscle pain and weakness in young, healthy volunteers

Ring, Susan M. Peterson, Catherine Ann. January 2009 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2009. / Thesis advisor: Dr. Catherine Peterson. The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. "May 2009" Includes bibliographical references.
536

Vitamin C as biomarker and treatment of oxidative stress caused by smoking : methodological and clinical studies /

Lykkesfeldt, Jens. January 2005 (has links)
Thesis (D. Phil.)--Københavns Universiteit, 2005. / With a summary in Danish. Includes bibliographical references.
537

Evaluation du statut en micronutriments lipophiles au cours de l'obésité : relation avec l'inflammation et l'insulino-résistance / Assessment lipophilic micronutrient status in obesity : relationship with inflammation and insulin resistance

Ben Amara, Nisserine 19 November 2013 (has links)
L’obésité s’accompagne d’un état inflammatoire chronique qui joue un rôle délétère.Cet état associé à l’obésité été impliqué dans le développement de complications métaboliques:insulino-résistance et DT2.Chez les obèses,le TA est un site de production de médiateurs pro et/ou anti-inflammatoires, des adipokines.Les modifications et changements de style de vie et les approches thérapeutiques sont privilégiés pour lutter contre l’obésité.Toutefois,les approches préventives ne doivent pas être négligées,des études épidémiologiques ont mises en évidence une corrélation entre obésité et carence en micronutriments.Par ailleurs,il existe une corrélation inverse entre micronutriments lipophiles et caroténoïdes et la prévalence de l’obésité et du DT2.Le but de cette thèse est de comprendre le lien qui existe entre carence en micronutriments,obésité et complications associés.Une étude clinique transversale a été réalisée chez des obèses non diabétiques.Les résultats nous ont permis de montrer qu’il existe une association positive entre b-carotène et sensibilité à l'insuline chez l'obèse,effet pouvant être lié à une modulation de l'expression de certaines adipokines dont l'adiponectine qui est indépendamment associée à la concentration plasmatique en b-carotène.Une étude préclinique a été menée, dont l'objectif évaluer l'impact de la teneur en vitamines alimentaires sur la prise de poids et l'insulino-sensibilité.Des souris ont été soumises à un régime hypovitaminé.A 10 semaines,ce régime favorise la prise de masse grasse,modifie la sensibilité à l'insuline,en agissant au niveau du métabolisme lipidique hépatique,via une diminution des capacités oxydatives. / Obesity is associated with chronic inflammatory condition that plays a deleterious role.This inflammatory state associated with obesity was involved in the development of metabolic complications : insulin resistance and T2DM.Obese, AT is a site for the production of pro and/or anti-inflammatory adipokines, and plays a major role in the development of chronic inflammation associated with obesity.Modifications and changes in lifestyle and therapeutic approaches are preferred to deal with obesity. However,preventive approaches should not be ignored,several epidemiological studies have shown a correlation between obesity and micronutrient deficiency.In addition,there is an inverse correlation between lipophilic micronutrients and carotenoids and the prevalence of obesity and T2DM.The purpose of this thesis is to understand the possible link between LM and carotenoids deficiency, obesity and associated physiological disorders.A cross-sectional study was performed in non-diabetic obese patients.The results allowed us to conclude the existence of a favorable effect of b-carotene on insulin sensitivity in obese patients.This effect may be related to modulation of inflammation or the expression of some adipokines(such as adiponectin), either directly or through its pro-vitamin A activity.A preclinical study was performed; the objective is to assess the impact of the vitamins on weight gain and insulin sensitivity.Mice were subjected to a hypovitaminic diet.After 10 weeks of regimen, we observed an increased adiposity and an altered insulin sensibility.This diet probably acts on the hepatic lipid metabolism via a decrease in oxidative capacity.
538

Postnatal vitamin D supplementation normalizes neonatal bone mass following maternal dietary vitamin D deficiency in the guinea pig

Finch, Sarah L. January 2007 (has links)
No description available.
539

Studies on the role of vitamin D in asthma patients from a South Florida pulmonary practice

Unknown Date (has links)
Vitamin D insufficiency/deficiency is widespread in asthma, and epidemiological studies point to an association between low serum 25-hydroxyvitamin D level and poor asthma control and increased severity. In humans. Vitamin D is principally derived from sunlight induced cutaneous conversion of 7-dehydrocholesterol to vitamin D and oral supplementation. We sought to determine if established and chronic-persistent adult asthma patients from a South-Florida pulmonary patient population, with abundant sunshine availability and oral vitamin D supplementation exhibit vitamin D insufficiency/deficiency. A trend to vitamin D insufficiency was observed in approximately 65% of both adult asthma patients and apparently healthy (non-asthmatic) volunteers. . The transcription factors required for Th9 conversion, PU.1 and IRF-4, were down-regulated by vitamin D. The generation of Th9 cells was inhibited equally by vitamin D and dexamethasone when used alone, but the effect was additive when both steroids were used in combination. Our studies using non-specifically stimulated cells were extended by analyzing the effect of vitamin D on allergen specific stimulation. The response of CD4+ T cells obtained from the blood of house dust mite positive asthmatics was studied. House dust mite allergen elicited a classical Th2 phenotype response (IL-4, IL-5, IL-9, and IL-13 cytokine profile) and vitamin D effectively inhibited those key Th2 cytokines. We conclude that vitamin D appears to be of significant clinical benefit in our cohort of patients, i.e., established chronic adult human asthma, by down-regulating key immune cells including Th9, Th17, and Th2 involved in this disorder. / by Amjad Munim. / Thesis (Ph.D.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
540

Effekten av vitamin D2 vs. D3 på 25(OH)D-statusen : En litteraturstudie / The effect of vitamin D2 vs. D3 on 25(OH)D status : A litterature study

Beyer, Sarah January 2018 (has links)
Bakgrund: Vitamin D finns i två olika former, det animaliska D3 (kolekalciferol) och det vegetabiliska D2 (ergokalciferol). Det har rått olika åsikter bland läkarkåren och allmänheten om vilken av de två formerna som är mest potent för att höja 25(OH)D-statusen i blodet, det värde som mäts för att avgöra vitamin D-halten i kroppen. Då vitamin D-brist är vanligt förekommande bland befolkningen i Norden är det viktigt att veta vilken form som har bäst effekt och som därför bör användas för att behandla och förebygga vitamin D-brist. Det har även betydelse för veganer som inte äter det animaliska D3, där rekommendationen kanske behöver ändras. Syfte: Syftet med studien var att ta reda på om det finns någon skillnad i potensen av D2 respektive D3 för att höja 25(OH)D-statusen i blodet och i så fall, att hitta möjliga orsaker till denna skillnad. Metod: Sex relevanta vetenskapliga originalartiklar, som har undersökt effekten av D2 vs. D3 på 25(OH)D-statusen i blodet, hittades i databasen PubMed. Studierna genomfördes mellan 2008 och 2017. Studiedeltagarna var vuxna friska människor. Resultat: Fyra av studierna pekade på att D3 var mer effektivt än D2 för att höja 25(OH)D-statusen. En studie kom fram till att det inte fanns någon skillnad i potensen mellan D2 och D3 och en studie visade att D2 var mer effektivt jämfört med D3 när det gällde daglig behandling med låga doser men att D3 uppvisade bättre effekt vid behandling med höga doser med två eller fyra veckors avstånd. Slutsats: Majoriteten av studierna visade en bättre effekt av D3 än D2 för att höja 25(OH)D-nivåer i blodet. De blandade resultaten samt det begränsade antalet studier och deltagare gör att det inte är möjligt att kunna komma fram till en tydlig slutsats. / Background: Vitamin D comes in two different forms, D3 from animals (cholecalciferol) and D2 from plants (ergocalciferol). There has been different opinions among physicians and the general public about which of the calciferols is more potent to raise 25(OH)D-levels in the blood, which is the value that is measured to determine the vitamin D-status in the body. Since vitamin D deficiency is common among the people of the Nordic countries it is important to know which form has the best effect and should be used to treat and prevent vitamin D deficiency. Furthermore, it is relevant for vegans who do not eat the animalic D3, where recommendations might have to be changed. Aim: The aim of the study was to find out if there were differences in potency of D2 vs. D3 to raise 25(OH)D status in the blood and if so, to find possible explanations for those differences. Methods: Six relevant original articles that examined the effect of D2 vs. D3 on 25(OH)D status in the blood, were found in the database PubMed. The studies where published between the years 2008 and 2017. The participants were healthy adults. Results: Four of the studies suggested that D3 is more effective than D2 in order to raise the 25(OH)D status. One study concluded that there is no difference in the effectiveness of D2 vs D3 and one study showed that D2 is more effective than D3 when it comes to daily treatment but that D3 has a better effect than D2 when treatment happens on a two or four weekly basis with large doses. Conclusion: Most of the articles suggested a better effectiveness of D3 than D2 to raise 25(OH)D levels in the blood. However, besides the mixed results, the number of studies and participants was too small to come to a clear conclusion.

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