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Ultraviolet (UV) radiation damages both eukaryotic and prokaryotic cells by causing the formation of free radicals which damage cell membranes and DNA. Antioxidant vitamins have been shown to protect cells from UV-induced damage by scavenging free radicals. The protection of skin and its normal flora is necessary for the health of individuals in resisting diseases caused by microorganisms and delaying the long-term damage caused by UV radiation.This research investigated the effects of the antioxidants vitamin A and ascorbic acid, as well as UV-irradiation on both prokaryotic (Staphylococcus epidermidis) cells and eukaryotic (human fibroblast skin) cells. This information is important in determining the effects of vitamin treatment on skin and its normal flora.Results indicate that ascorbic acid is rapidly (within six hours) degraded after being dissolved in water or medium. Treatment of cells with ascorbic acid must take into account this rapid degradation. S.epidermidis cells were protected from UV-induced damage by treatment with ascorbic acid but were more sensitive to UV-irradiation when treated with vitamin A. Human fibroblast cells treated with ascorbic acid did not exhibit morphological changes when compared to untreated cells. / Department of Biology

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2004. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2005. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 5 uppsatser.

Background Empirical research on how and why nutritional supplements (including vitamin/mineral supplements and herbal supplements) are being taken by middle-income populations in South Africa is lacking. This study quantifies the types of nutritional supplements being taken. It unpacks beliefs regarding benefits and risks. This information is useful for healthcare practitioners in similar settings as it could affect their practice of history taking and alert practitioners to the need to know more about nutritional supplement benefits and risks. The information could be used to influence policy regarding advertising and labelling of nutritional supplements. Method The study was a cross-sectional survey. An anonymous self-completed structured questionnaire was completed by 123 participants attending a medical centre during the data collection period. Face-to-face semi-structured interviews were conducted on 16 participants to gather qualitative information. Results Nutritional supplements were widely taken in this questionnaire sample (59%). Consumption was not related to age, language, ethnic group, education and smoking, but nutritional supplements were more commonly used by women and higher income groups. Women who felt they had fair/poor health, women with chronic medical conditions, especially those with depression or women on chronic prescription medication were more likely to take nutritional supplements than those without these characteristics. Wellness, treating tiredness and short-term disease prevention were the most common reasons for taking the supplements, although research proving these benefits is lacking. Chronic disease prevention was an uncommon reason for consumption. Participants were mostly unaware of possible drug interactions and side-effects and therefore felt it unnecessary to inform their practitioner of consumption habits. Conclusion Healthcare professionals should include a nutritional supplement question in their routine history taking, especially when prescribing chronic medication and in the presence of chronic conditions. They should be knowledgeable regarding efficacy, safety, possible side-effects and drug interactions of commonly consumed nutritional supplements in order to advise patients appropriately. Further empirical research is needed into proven benefits of nutritional supplements.

Made available in DSpace on 2014-06-11T19:30:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-07-17Bitstream added on 2014-06-13T19:40:15Z : No. of bitstreams: 1 falcon_dr_dr_jabo.pdf: 461595 bytes, checksum: ff7df55be464ec45aac9ae10bfc540cd (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O presente projeto constou de dois estudos com o objetivo de avaliar a inter-relação entre o imunoestimulante β-glucano e a vitamina C em dietas práticas para a tilápia do Nilo (Oreochromis niloticus). No Estudo – I foi avaliado, após 60 dias experimentais (primeira fase), o melhor nível de suplementação do β-glucano (0,1; 0,2; 0,4 e 0,8 % na dieta) e vitamina C (400 e 600 mg/kg da dieta) para desempenho produtivo, parâmetros hematológicos e imunológicos (determinação dos intermediários reativos do oxigênio e do nitrogênio), num delineamento inteiramente casualizado em esquema fatorial 4 x 2, mais um tratamento controle sem suplementação do β-glucano e 125 mg de vitamina C/kg de dieta, totalizando nove tratamentos e quatro repetições. Após essa primeira fase, os peixes foram divididos em dois grupos. Um grupo foi submetido ao estímulo pelo frio e o outro ao desafio com Aeromonas hydrophila, avaliando-se os mesmos parâmetros da primeira fase, além da porcentagem de sobrevivência. No Estudo – II objetivou-se determinar o melhor tempo de administração de β-glucano e da vitamina C (45, 30, 15 e sete dias antecedendo os desafios) utilizando-se o melhor nível de inclusão do β-glucano e da vitamina C, obtidos no estudo I. Os desafios utilizados foram: estímulo pelo frio, estresse por transporte e desafio com Aeromonas hydrophila. Estes foram avaliados por meio dos mesmos parâmetros anteriores. Concluiu-se no estudo I que a suplementação de β-glucano e vitamina C não influenciam o desempenho produtivo da tilápia do Nilo; que a suplementação de 0,1% de β-glucano e 600,0 mg de vitamina C/kg da dieta determina melhores respostas imunológicas frente ao estímulo pelo frio e desafio com a bactéria Aeromonas hydrophila e que, níveis elevados de suplementação de β-glucano (0,4 e 0,8%) promovem redução dos parâmetros imunológicos avaliados,... / The development of aquaculture associated to the intensification of production system determined the interest in immunostimulant in fish diets. Growth performance, hematological and immune responses of Nile tilapia were determined in this research. Fish were fed diets containing 28.0% and DP/3000 kcal DE/kg and supplemented with levels of β-glucan (0.1; 0.2; 0.4 e 0.8%) and vitamin C (400 e 600 mg/kg diet) distributed in a factorial design (4 x 2) plus a control treatment without β-glucan and supplemented with 125.0 mg vit C/diet). After 60 days, growth performance of 252 tilapia (16.86 ± 0.24g), randomly distributed in 36 250L-aquaria were determined, then 108 fish were submitted to cold stress (seven days/18.0ºC) and 108 were challenged with Aeromonas hydrophila (concentration of 105UFCml-1/15 days). Hematological and immunological parameters (reactive oxygen and nitrogen intermediates) were determined before and after challenges. Therefore, it is concluded that β-glucan and vitamin C did not influence growth performance; 0.1% of β-glucan and 600.0 mg of vit C/kg diet determine better immunological response related to cold stress and Aeromonas hydrophila challenge and that high levels of β-glucan supplementation (0.4 and 0.8%) determine a reduction of parameters immunological evaluated, independent of vitamin C supplementation.

Made available in DSpace on 2014-06-11T19:32:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-03-12Bitstream added on 2014-06-13T19:43:50Z : No. of bitstreams: 1 guimaraes_ig_dr_botfmvz.pdf: 795190 bytes, checksum: 857e85c2b9cc52423105a0f4798b81d0 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / O efeito da vitamina A sobre os parâmetros de desempenho da tilápia do Nilo foi avaliado em um experimento com duração de 130 dias. Trezentos e vinte alevinos de tilápia do Nilo (7,43 ± 0,19g) foram aleatoriamente distribuídos em 40 aquários de fibra de vidro com volume total de 250L e alimentados com dieta prática contendo níveis crescentes de vitamina A (0, 200, 400, 800, 1.600, 3.200, 6.400, 12.800 UI de vit. A/kg da dieta). A fonte de vitamina utilizada foi o acetato de retinol (Rovimix A 1000). Ao final do período experimental os peixes foram pesados e a ração quantificada para a avaliação do ganho de peso médio, conversão alimentar aparente (CAA), consumo diário de ração, porcentagem de sobrevivência, taxa de crescimento específico (TCE), taxa de eficiência protéica (TEP) e taxa de retenção protéica (TRP). Foi observado efeito quadrático (P<0,01) para todas as variáveis com o aumento do nível de vitamina A nas dietas com exceção da CAA e TEP. Os peixes alimentados com as dietas não suplementadas apresentaram reduzida TEP e piores índices de CAA. Sinais de deficiência de vitamina A observados neste estudo foram: apatia, natação errática, exoftalmia, petéquias hemorrágicas localizadas na base da nadadeira caudal e superfície corporal, e presença de ascite na cavidade abdominal. A presença de níveis adequados de vitamina A é essencial para o adequado crescimento da tilápia do Nilo e a exigência com base no ganho de peso e taxa de retenção protéica foi de 4.704 e 5.300 UI de vit. A/ kg da dieta, respectivamente. / A 130-day feeding trial was undertaken to evaluate the effect of vitamin A on growth performance of sex reversed Nile tilapia (Oreochromis niloticus). 320 Nile tilapia fingerlings with 7.49 ± 0.19g weight (mean±SD) were randomly stocked into 40 250Laquaria and fed practical diets containing graded levels of vitamin A (0; 200; 400; 800; 1,600; 3,200; 6,400; 12,800 IU vit. A/kg diet). Vitamin A source was retinol acetate (Rovimix A 1000). At the end of the experimental period fish and diets were weighed to evaluate weight gain (WG), feed conversion ratio (FCR), survival (SUR), specific growth rate (SGR), protein efficiency ratio (PER) and protein retention (PR). All gowth parameters showed quadratic effect (P<0.01) according to vitamin A level regardless the FCR and PER. Fish fed the non-supplemented diet showed reduced PER and higher FCR. Clinical signs of vitamin A deficiency observed in this study were resting and abnormal swimming behavior, exophthalmia, hemorrhages at the base of fins and on skin and serous fluids in abdominal cavity. Adequate vitamin A levels are necessary for normal Nile tilapia growth and vitamin A requirement based on WG and PR is 4,704 and 5,300 IU vit. A/kg diet, respectively.

Made available in DSpace on 2015-04-17T14:49:18Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 787297 bytes, checksum: ef844b907c7df9d6b79a546d0a5cdc3b (MD5) Previous issue date: 2009-09-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The carciniculture is an important economic activity for Brazil, basically in the farming of a specific shrimp species (Litopenaeus vannamei). This species has shown in the last years an unsatisfactory performance due to problems caused by illnesses. That has been increasing the interest for the farming of native species like the Farfantepenaeus subtilis which has a better resistance to illnesses, besides being tolerant to several salinity variations they also have an availability of adult females and post larvae and a facility for reproduction in confined places. The nutrition of this species has to be better studied, like the necessities of vitamins A, E and C in these animals s diets. As well as knowing the stability of these vitamins in the processing, storage and handling of this diet. This study consisted of a formulation of eight diets with different levels of vitamins A, E and C and a control diet (with no vitamins). The vitamins were quantified right after the storage period (60 days) to evaluate the losses. The shrimps of the Farfantepenaeus subtilis species were fed with these diets for thirty days, in which it was evaluated the biomass gain and the survival rate. The major vitamin losses were of retinol, α-tocopherol, and ascorbic acid, respectively. The major survival rates (100%) were observed in the R1 and R4 diets which received different levels of vitamin E (184 e 364 UI/Kg), respectively. / A carcinicultura é uma atividade economicamente importante para o Brasil, sendo baseada praticamente no cultivo de uma espécie de camarão (Litopenaeus vannamei). Esta espécie nos últimos anos tem mostrado desempenho insatisfatório devido aos problemas causados por enfermidades. Isso vem despertando o interesse pelo cultivo de espécies nativas como o Farfantepenaeus subtilis que possui uma resistência maior as enfermidades, além de ser tolerante a amplas variações de salinidade, tem disponibilidade de fêmeas maduras e póslarvas e a facilidade de reprodução em ambientes confinados. A nutrição da espécie Farfantepenaeus subtilis precisa ser melhor estudada, como as necessidades de vitaminas A, E e C nas dietas destes animais. Assim como conhecer a estabilidade destas vitaminas frente ao processamento da dieta e ao armazenamento e manejo. O estudo consistiu na formulação de oito dietas com diferentes níveis de vitaminas A, E e C e uma dieta controle (sem vitaminas). As vitaminas foram quantificadas logo após o processamento das dietas e após período de armazenagem (60 dias) para avaliar as perdas. Os camarões da espécie Farfantepenaeus subtilis foram alimentados com estas dietas durante trinta dias, onde foram avaliados o ganho de biomassa e a taxa de sobrevivência. As maiores perdas vitamínicas foram de retinol, α-tocoferol e ácido ascórbico, respectivamente. As maiores taxas de sobrevivência (100%) foram observadas no tratamento R1 e R4 que receberam diferentes níveis de vitamina E (184 e 364 UI/Kg) respectivamente.

Les produits déshydratés permettent d’optimiser la conservation et le transport des aliments. Les poudres alimentaires distribuées au consommateur affichent des garanties nutritionnelles en termes d’apports qualitatif et quantitatif. Cependant, l’apport nutritionnel du produit après reconstitution et cuisson, n’est pas garanti. Ce travail se concentre sur l’évaluation des pertes en vitamines dues aux procédés de transformation alimentaire en lien avec l’effet de la matrice alimentaire. Ces pertes mesurées après le traitement thermique ne sont pas négligeables, rendant l’encapsulation nécessaire pour répondre à l’objectif de la thèse de garantir une teneur en vitamines suffisante après reconstitution et traitement thermique du produit alimentaire déshydraté. Différentes matrices ont été testées à l’échelle laboratoire et industrielle. Parmi ces matrices, certaines comme les protéines laitières et l’amidon se sont avérées très intéressants et ont permis la préservation de la vitamine C du traitement thermique. Pour finaliser l’étude, il a été indispensable de prendre en compte le stockage des poudres de la vitamine C encapsulée avant et après leur commercialisation. Pour assurer leur teneur suffisante en vitamine C lors ce stockage, un vieillissement accéléré a été effectué. Cette thèse a permis d’apporter des réponses concrètes au problème industriel posé, qui était de garantir la teneur en vitamine C des produits commercialisés après reconstitution et traitement thermique / Dehydrated products make it possible to optimize the storage and transport of food products. Food powder mixes distributed to the consumer display nutritional guarantees in terms of qualitative and quantitative inputs. However, the nutritional value of the product after reconstitution and cooking, is not guaranteed. This PhD work focuses on the evaluation of vitamins losses due to food processing in relation to the effect of the food matrix. Losses measured after the heat treatment were not negligible, making the encapsulation necessary to meet the objective of the thesis to guarantee a sufficient vitamins content after reconstitution and heat treatment of the dehydrated food product. Different matrices have been tested at the laboratory scale and industrial scales. Some of these matrices, such as dairy proteins and starch, have proved to be very interesting and allowed the preservation of vitamin C during heat treatment. To finalize the study, it was essential to take into account that the vitamin C-encapsulating powders will be stored before and after their distribution. To ensure that they maintain a sufficient vitamin C content during storage, accelerated aging has been carried out. Thus this thesis made it possible to provide concrete answers to the posed industrial problem, which was to guarantee the vitamin C content of the commercial products after reconstitution and heat treatment