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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.
101

Effects of dietary fat and fiber on the oxidative status of the small intestine and colon of rats

Sanders, Lisa Merle 16 August 2006 (has links)
Colon cancer is one of the most commonly diagnosed cancers in the US, yet small intestine cancer is a rare event. While there are many similarities between these two tissues, inherent differences such as redox status, may contribute to the variation in cancer occurrence. We examined the difference in reactive oxygen species (ROS) generation, antioxidant enzyme activity and oxidative DNA damage in the small and large intestine of rats under normal conditions and following exposure to exogenous oxidative stress. Basal ROS and antioxidant enzyme activities were greater in the colon than the small intestine, and the balance of ROS to antioxidant enzymes in the colon was more pro-oxidant than in the small intestine. During oxidative stress, ROS and oxidative DNA damage were greater in the colon than the small intestine. Thus the colon responds to oxidative stress less effectively than the small intestine, possibly contributing to increased cancer incidence at this site. We next wanted to understand how diets containing a combination of fish or corn oil and pectin or cellulose may alter the redox environment of the colon. ROS, oxidative DNA damage, antioxidant enzyme activity and apoptosis were measured in colonocytes of rats fed one of four diets containing either corn oil or fish oil and cellulose or pectin. Measurements were madein rats untreated with carcinogen and rats exposed to a chemical carcinogen and radiation. In rats not treated with a carcinogen, fish oil enhanced ROS, and fish oil/pectin suppressed antioxidant enzymes as compared to corn oil/cellulose. Oxidative DNA damage was inversely related to ROS in the fish oil/pectin diet and apoptosis was enhanced relative to other diets. In carcinogen treated and irradiated rats, a similar protective effect was seen with fish oil/pectin as evidenced by a reduction in oxidative DNA damage and enhancement of apoptosis. This suggests that a diet containing fish oil/pectin may protect against colon carcinogenesis by modulation of the redox environment to promote apoptosis and minimize oxidative DNA damage.
102

Eliminació de contaminants orgànics persistents d’oli de peix

Ortiz Almirall, Xavier 15 June 2011 (has links)
En la present tesi doctoral s’han estudiat diversos mètodes per a l’eliminació de contaminants orgànics persistents en olis de peix amb finalitat alimentària. S’han posat al punt les metodologies d’anàlisi necessàries per a la correcta determinació d’aquests compostos en la matriu d’estudi. S’han avaluat amb detall les etapes de purificació de la mostra, fraccionament dels analits i anàlisi instrumental. El mètode ha estat validat amb resultats satisfactoris, i s’ha comprovat el seu bon funcionament a través de la participació en diversos exercicis d’intercalibtage, així com la realització de diversos estudis amb mostres reals d’oli de peix. S’ha estudiat l’eliminació dels contaminants orgànics persistents a través d’adsorbents sòlids amb base silícica i carbonàcia. Les condicions experimentals han estat estudiades més a fons mitjançant dissenys d’experiències, per acabar optimitzant el mètode d’adsorció amb un disseny d’evolució. Els millors resultats s’han obtingut amb el carbó actiu, que mostra una elevada eficàcia en l’eliminació de PCDD/Fs, d-l PCBs i HCB. S’ha estudiat l’eliminació dels contaminants orgànics persistents mitjançant tècniques de degradació fotoquímiques. Inicialment s’ha fotodegradat cada família de contaminants per separat, per poder estudiar més a fons les condicions necessàries per la seva eliminació, així com els seus mecanismes i productes de degradació. Posteriorment s’ha estudiat la fotodegradació simultània dels analits d’interès en oli de peix. Aquesta tècnica s’ha mostrat efectiva en l’eliminació de DDT, PBDEs, HCB i PCBs similars a dioxines. Paral•lelament als estudis d’eliminació mitjançant adsorbents sòlids i tècniques fotoquímiques, s’ha comprovat la qualitat dels olis de peix abans i després del tractament. El procés d’adsorció en sòlids no afecta significativament a la qualitat de l’oli, mentre que les tècniques fotoquímiques degraden una part dels àcids grassos insaturats. S’ha estudiat l’eliminació de contaminants orgànics persistents en oli de peix mitjançant la combinació de les dues tècniques estudiades anteriorment, amb una primera etapa de degradació fotoquímica i una segona etapa d’adsorció. S’han comparat els resultats finals d’eliminació que s’obtenen amb cada un dels mètodes desenvolupats (adsorció, fotodegradació i combinat). L’adsorció en carbó actiu és el procés més adequat per l’eliminació de COPs en oli de peix. S’ha realitzat un estudi dels nivells diastereomèrics i enantiomèrics d’un contaminant emergent -l’hexabromociclododecà (HBCD)- en oli de peix. S’ha avaluat la seva eliminació de la matriu d’estudi mitjançant adsorbents amb base carbonàcia i degradació fotoquímica, sent principalment eliminat per aquesta segona via. / En la presente tesis doctoral se han estudiado diversos métodos para la eliminación de contaminantes orgánicos persistentes en aceites de pescado con finalidad alimentaria. Se han desarrollado los métodos de análisis necesarios para la correcta determinación de estos compuestos en la matriz de estudio. Se han evaluado con detalle las etapas de purificación de la muestra, fraccionamiento de los analitos y análisis instrumental. El método ha sido validado con resultados satisfactorios, y se ha comprobado su buen funcionamiento mediante ejercicios de intercalibraje, así como la realización de diversos estudios con muestras reales de aceite de pescado. Se ha estudiado la eliminación de los contaminantes persistentes mediante adsorbentes sólidos con base silícica y carbonacea. Las condiciones experimentales han estado estudiadas en profundidad mediante diseños de experiencias y de evolución. Los mejores resultados se han obtenido con carbón activo, que demuestra una elevada eficacia en la eliminación de PCDD/Fs, dl-PCBs y HCB. Se ha estudiado la eliminación de los contaminantes orgánicos persistentes mediante técnicas de degradación fotoquímica. Inicialmente se ha fotodegradado cada familia de contaminantes por separado, para poder estudiar más a fondo las condiciones necesarias para su eliminación. Posteriormente se ha estudiado la degradación simultánea de los analitos de interés en aceite de pescado. Esta técnica se ha mostrado efectiva en la eliminación de DDT, PBDEs, HCB y PCBs similares a dioxinas. Paralelamente a los estudios de eliminación mediante adsorbentes sólidos y técnicas fotoquímicas, se ha comprobado la calidad de los aceites de pescado antes y después del tratamiento. El proceso de adsorción en sólidos no afecta significativamente a la calidad del aceite, mientras que las técnicas fotoquímicas degradan una parte de los ácidos grasos insaturados. Se ha estudiado la eliminación de contaminantes orgánicos persistentes en aceites de pescado mediante la combinación de las dos técnicas estudiadas anteriormente, con una primera etapa de degradación fotoquímica y una segunda etapa de adsorción. Se han comparado los resultados finales de eliminación que se obtienen con cada uno de los métodos desarrollados. La adsorción en carbón activo es el proceso más adecuado para la eliminación de COPs en aceite de pescado. Se ha realizado un estudio de los niveles diastereoisoméricos y enantioméricos de un contaminante emergente –HBCD- en aceite de pescado. Se ha evaluado su capacidad de eliminación de la matriz de estudio mediante adsorbentes con base carbonacia y degradación fotoquímica, siendo principalmente eliminado por la segunda vía. / During the present doctoral thesis several methods for the elimination of persistent organic pollutants from fish oil have been studied. Analytical methodologies for the determination of these compounds in fish oil have been developed. Sample purification, fractionation of the analytes and instrumental determination steps have been deeply studied. The method has been validated with satisfactory results, and its performance has been verified through its participation in several intercalibration exercises and studies with real fish oil samples. Elimination of persistent organic pollutants with silicon and carbon-based adsorbents has been studied. The experimental conditions have been studied in depth with an experimental design, to finally optimize the adsorption method using an evolutionary design. Best results have been obtained with the active carbon, showing high efficiency of the removal of PCDD/Fs, dioxin-like PCBs and HCB. Elimination of persistent organic pollutants with photochemical degradation techniques has been studied. Initially, each family of pollutants has been photodegraded separately, to determine its degradation conditions, as well as degradation mechanisms and by-products. Later, simultaneous photodegradation of the analytes has been studied in fish oil. This technique has shown high efficiency on the degradation of DDT, PBDEs, HCB and dioxin-like PCBs. The quality of the oils before and after the treatments with solid adsorbents and photochemical degradation has also been studied. The adsorption process does not significantly affect the quality of the oils, while photochemical techniques can degrade the unsaturated fatty acids. Elimination of persistent organic pollutants in fish oil combining adsorption in solids and photochemical degradation has been studied. Results obtained with each of the developed methodologies (adsorption, photodegradation and combined method) were compared. Adsorption in active carbon is the most suitable process for COPs elimination in fish oil. Finally, diastereoisomeric and enantiomeric levels of an emerging pollutant –hexabromocyclododecane (HBCD)- in fish oil have been studied. Its elimination has been evaluated with carbon-based adsorbents and photochemical degradation, being mainly eliminated with the photodegradation techniques.
103

The effect of dietary n-3 polyunsaturated fatty acids on T cell subset activation-induced cell death

Switzer, Kirsten Collette 15 November 2004 (has links)
Dietary n-3 polyunsaturated fatty acids (PUFA) have been shown to potently attenuate T cell-mediated inflammation, in part, by suppressing T cell activation and proliferation. Apoptosis is an important mechanism for preventing chronic inflammation by maintaining T cell homeostasis through the contraction of populations of activated T cells. We hypothesized that dietary n-3 PUFA would promote T cell apoptosis, thus, providing an additional mechanism to explain the anti-inflammatory effects. We specifically examined activation-induced cell death (AICD) since it is the form of apoptosis associated with peripheral T cell deletion involved in immunological tolerance and T cell homeostasis. Female C57BL/6 mice were fed diets containing either n-6 PUFA (control) or n-3 PUFA for 14 d. Splenic T cells were stimulated with CD3/CD28, CD3/PMA, or PMA/Ionomycin for 48 h followed by reactivation with the same stimuli for 5 h. Apoptosis was measured using Annexin V/propidium iodide and flow cytometry. Cytokine analyses revealed that n-3 PUFA enhanced AICD only in T cells expressing a Th1-like cytokine profile (high IFN, low IL-4) compared to mice fed the n-6 PUFA control diet. Dietary n-3 PUFA significantly altered the fatty acid composition of phosphatidylcholine and phosphatidylethanolamine in T cell membranes. To examine the apparently selective effect of dietary n-3 PUFA on AICD in Th1 cells, CD4+ T cells were polarized in vitro to a Th1 phenotype by culture with IL-4, IL-2, and IL-12 for 2 d, followed by culture with IL-2 and IL-12 for 3 d in the presence of diet-matched homologous mouse serum (MS) to prevent loss of cell membrane fatty acids. Following polarization and reactivation, we observed that n-3 PUFA enhanced Th1 polarization and AICD only in cells cultured in the presence of MS, but not in fetal bovine serum. The n-3 PUFA enhancement of Th1 polarization and AICD was associated with the maintenance of diet-induced changes in EPA (20:5n-3) and DHA (22:6n-3) in plasma T cell membrane lipid rafts. Overall, these results suggest that dietary n-3 PUFA enhance both the polarization and deletion of pro-inflammatory Th1 cells, possibly as a result of alterations in lipid raft fatty acid composition.
104

Effects of dietary fat and fiber on the oxidative status of the small intestine and colon of rats

Sanders, Lisa Merle 16 August 2006 (has links)
Colon cancer is one of the most commonly diagnosed cancers in the US, yet small intestine cancer is a rare event. While there are many similarities between these two tissues, inherent differences such as redox status, may contribute to the variation in cancer occurrence. We examined the difference in reactive oxygen species (ROS) generation, antioxidant enzyme activity and oxidative DNA damage in the small and large intestine of rats under normal conditions and following exposure to exogenous oxidative stress. Basal ROS and antioxidant enzyme activities were greater in the colon than the small intestine, and the balance of ROS to antioxidant enzymes in the colon was more pro-oxidant than in the small intestine. During oxidative stress, ROS and oxidative DNA damage were greater in the colon than the small intestine. Thus the colon responds to oxidative stress less effectively than the small intestine, possibly contributing to increased cancer incidence at this site. We next wanted to understand how diets containing a combination of fish or corn oil and pectin or cellulose may alter the redox environment of the colon. ROS, oxidative DNA damage, antioxidant enzyme activity and apoptosis were measured in colonocytes of rats fed one of four diets containing either corn oil or fish oil and cellulose or pectin. Measurements were madein rats untreated with carcinogen and rats exposed to a chemical carcinogen and radiation. In rats not treated with a carcinogen, fish oil enhanced ROS, and fish oil/pectin suppressed antioxidant enzymes as compared to corn oil/cellulose. Oxidative DNA damage was inversely related to ROS in the fish oil/pectin diet and apoptosis was enhanced relative to other diets. In carcinogen treated and irradiated rats, a similar protective effect was seen with fish oil/pectin as evidenced by a reduction in oxidative DNA damage and enhancement of apoptosis. This suggests that a diet containing fish oil/pectin may protect against colon carcinogenesis by modulation of the redox environment to promote apoptosis and minimize oxidative DNA damage.
105

Physicochemical properties and microencapsulation process development for fish oil using supercritical carbon dioxide

Seifried, Bernhard Unknown Date
No description available.
106

Body composition analysis in the assessment of cancer cachexia treatment outcomes

Aslani, Alireza January 2009 (has links)
Doctor of Philosophy / Introduction Cachexia is characterised by a marked weight loss and the presence of anorexia, anaemia, and asthenia. Although cachexia is often associated with the presence and growth of tumour and observed in solid tumours of the upper gastrointestinal tract, its presence is not unique to cancer and is often also present in most chronic, end-stage diseases processes. The loss of body fat, altered lipid metabolism, increase in the resting energy expenditure, and the increased loss of body protein the degree of which is associated with poor survival, are all hallmarks of this detrimental disease. The clinical aspects and consequences of cachexia can simply be summarised as morbidity, debilitating conditions, and mortality. The conditions such as loss of muscle mass, impaired muscle function, fatigue, reduced activity and functional capacity by themselves are enough to severely and significantly affect the patients’ QL. Although different interventional procedures and therapies are available for the treatment of cachexia and its symptoms, effective methods to evaluate their benefits and outcomes have not been tested or investigated. It was, therefore, the aim of this project to use body composition analysis as a clinical tool and evaluate the effectiveness and outcome of interventional and therapeutic procedures in three groups of patients with cancer. Methods Three patient groups were investigated: 1) patients with pancreatic cancer undergoing Whipple’s Procedure, 2) patients with pancreatic cancer undergoing cancer chemotherapy and receiving either EPA or placebo, and 3) patients with malignant mesothelioma undergoing cancer chemotherapy plus thalidomide or thalidomide alone. Body composition analysis techniques were used to assess the changes in TBN, TBF, TBK, and TBW. In addition, the body composition parameters together with clinical measures were also used to determine parameters influencing survival. The malignant mesothelioma patients were randomised into patients who received gemcitabine / cisplatin plus thalidomide and those who received thalidomide alone. The pancreatic cancer patients undergoing chemotherapy were randomised into the group who were receiving EPA and those who were receiving placebo. In addition, these patients were also investigated on the basis of their disease extent where they were separated into two groups of metastatic and locally advanced. Unpaired T-Test and ANOVA were used to determine differences between groups. Kaplan-Meier analysis and Cox’s Regression were used to assess survival in all three patient cohorts. The Whipple’s Procedure patients were separated into those who received a Clear Margin and those who received an Unclear Margin during their resection. Results 1) In the pancreatic cancer patients undergoing Whipple’s Procedure, compared to the base-line, there were highly significant changes in Weight (p=0.006), BMI (p=0.005), and FM (p=0.007) followed by significant changes in %BFat (p=0.016), TBK/Ht (p=0.021), LBM (By TBK) (p=0.023), LBM (Van Loan) (p=0.034), and LBM (Segal) (p=0.038) at the 14 week time-point. At the 26 weeks post-operative time point, the only significant changes were in the FM (p=0.012), %BFat (p=0.003), and BMI (p=0.027) parameters. There was also a deviation between the two groups in their TBN, LBM and TBW content observable in a long-term setting and fat content in the relatively shorter-term. Although the Unclear Margin group had lower body composition values, both groups seem to begin to gradually “equalise” around the 14 weeks post-operative time-point. The survival analysis results for the Whipple’s Procedure patients demonstrated that Margin Status (p=0.001), Fat Mass (p=0.003) and Age (p=0.081) were significant and could influence survival. 2) When the second cohort pancreatic cancer patients undergoing chemotherapy were analysed, they were initially separated according to the extent of their disease The results of the analyses of body composition changes between measurement time-points for the each group separately, suggested that the patients with locally advanced disease maintain their Weight, FM, and TBN but are more likely to have a lower TBW by the end of the four month of chemotherapy. However, the patients with metastatic pancreatic cancer maintain their TBW but are more likely to have a decreased fat compartment and a higher FFM. The QL analysis showed that the metastatic group are performing “worse” than the locally advanced group especially in term of their Dyspnoea, Nausea & Vomiting, and Sexuality. In addition, the Karnofsky score showed that the metastatic group are not performing as well as the locally advanced group. Furthermore, for the metastatic group there was an increase in the patients’ pain with a decline in mood and general performance as well as increase in gastrointestinal symptoms. Pain Card scores also showed a general increase for the metastatic group and a general decrease for the locally advanced group. When the pancreatic cancer patients undergoing chemotherapy were separated according to whether they received EPA or placebo, the results demonstrated that firstly, due to the fact that the patients were well randomised, the two groups commenced the trial with similar and statistically non-significantly different body composition parameters. Secondly, the two groups were also found to be statistically not different at their corresponding measurement time-points. And thirdly, the patients receiving placebo compared to those receiving EPA lost more Weight, and FM but less TBW throughout the trial. The TBK/Ht (p=0.044), TBK (p=0.042), and LBM (By TBK) (p=0.042), however, showed statistically significant differences where in all three parameters the EPA showed an increase compared to the base-line (pre-chemotherapy). Results of the survival analysis demonstrated that the use of EPA in this group of pancreatic cancer patients did not provide any benefit. In fact, as it was shown in the Kaplan-Meier plot, the group of patients receiving the EPA had a “worse” survival than the group receiving the placebo. The QL results showed that placebo group improved in their functional scales, but increased their Altered Bowel Habit scores with an increase in the perception of pain and decrease in relief from pain. The EPA group, however, showed a decrease in the Loss of Appetite, Dyspnoea, Pain, Pancreatic Pain, and Fatigue, and improvements in Role Functioning and Sexuality. 3) Results of the malignant mesothelioma patients demonstrated that both study arms show similar weight changes. In addition, body composition measurements indicated that the gemcitabine / cisplatin chemotherapy plus thalidomide group had a greater TBN loss and a greater TBW gain than the thalidomide-alone group. This loss of TBN and gain in TBW looked to be “concealed” in the weight. The results of the survival analysis carried out on the mesothelioma patient group suggested that haemoglobin levels (p=0.001), Age (p=0.007), and NI (p=0.008) are the parameters that can influence the survival of patients with malignant mesothelioma undergoing chemotherapy. Conclusions 1) The trend in body composition changes in the Whipple’s Procedure group showed that, although both groups may start with non-significantly different body composition, they tended to grow closer around the 14 week point indicating that the Clear Margin group may lose more than Unclear Margin group. The implications of these findings, therefore, were that once the most appropriate surgical procedure is performed, an adjuvant therapy regimen (such as chemotherapy) at around 14 weeks may have the most impact on the patient’s overall treatment outcome. 2) When the pancreatic cancer patients were separated by the extent of their disease, the results lead to the conclusion that the patients with locally advanced disease maintain their Weight, FM, and TBN but are more likely to have a lower TBW by the end of the four month of chemotherapy. However, the patients with metastatic pancreatic cancer maintain their TBW but are more likely to have a decreased fat compartment and a higher FFM. The QL analysis concluded that the results may point to a worsening and/or progressing disease which is consistent with classic metastatic disease aetiology. From the results of the pancreatic cancer patients undergoing cancer chemotherapy it was concluded that the use of EPA in this group of pancreatic cancer patients undergoing cancer chemotherapy with gemcitabine results in a non-significant reduction in weight loss, FM loss, and TBW gain with a statistically significant increase in FFM. The results of the survival analysis was, however, contradictory suggesting that patients receiving EPA may have a worse survival than the placebo group. The QL analysis here concluded that that EPA does improve the QL of this group of pancreatic cancer patients. 3) From the malignant mesothelioma group it was concluded that provided that the overall anti-cancer potential of gemcitabine / cisplatin plus thalidomide is comparable with that of thalidomide-alone, then by looking purely from the body composition angle one may be able to suggest the use of thalidomide alone in the treatment of malignant mesothelioma in this group of patients. From the results of the survival analysis, the fact that the Study Arm parameter did not reach statistical significance could indicate that survival in these patients is not affected by the presence or absence of chemotherapy with gemcitabine and cisplatin. The body composition techniques were used here as a tool to monitor changes in various body composition parameters to assess the outcomes, including survival, of the administration of different therapies and interventional procedures in these three groups of cancer patients. For these purposes, these techniques were demonstrated to be an effective and invaluable tool.
107

The independent effects of purified EPA and DHA supplementation on cardiovascular risk in treated-hypertensive type 2 diabetic individuals

Woodman, Richard John January 2003 (has links)
[Formulae and special characters can only be approximated here. Please see the pdf version of the Abtract for an accurate reproduction.] Type 2 diabetes at least doubles the risk of cardiovascular disease. This can partly be explained by the increased prevalence of risk factors such as hypertension, dyslipidaemia and obesity. However, the underlying abnormality of insulin resistance and the presence of more recently identified risk factors including endothelial dysfunction, increased inflammation, and increased oxidative stress might also contribute towards the heightened cardiovascular risk. Fish oil, which contains eicosapentaenoic acid (EPA, 20:5 n-3), has wide-ranging beneficial effects on these and other abnormalities, and has reduced cardiovascular mortality in secondary prevention studies. Animal and human studies have recently established that in addition to EPA, docosahexaenoic acid (DHA, 22:6 n-3) also has beneficial effects, and furthermore, may have less detrimental effects than EPA on glycaemic control which has worsened in some fish and fish oil studies involving Type 2 diabetic subjects. Study 1 : This intervention study aimed to determine the independent effects of EPA and DHA on cardiovascular risk factors and glycaemic control in individuals with Type 2 diabetes receiving treatment for hypertension. In a double-blind placebo-controlled trial of parallel design, 59 subjects in good to moderate glycaemic control (HbA1c < 9%) were recruited from media advertising and randomised to 4 g/day of EPA, DHA or olive oil (placebo) for 6 weeks. Thirty-nine men and 12 post-menopausal women aged 61.2±1.2 yrs completed the study. Relative to placebo, and with Bonferroni adjustments for multiple comparisons, serum triglycerides fell by 19% (p=0.022) and 15% (p=0.022) in the EPA and DHA groups respectively. There were no changes in serum total cholesterol, or LDL- and HDL-cholesterol, although HDL2-cholesterol increased 16% with EPA (p=0.026) and 12% with DHA (p=0.05). HDL3-cholesterol fell by 11% (p=0.026) with EPA supplementation and LDL particle size increased by 0.26±0.10 nm (p=0.02) with DHA. Urinary F2-isoprostanes, an in-vivo marker of oxidative stress was reduced by 19% following EPA (p=0.034) and by 20% following DHA. DHA but not EPA supplementation reduced collagen-stimulated platelet aggregation (16.9%, p=0.05) and thromboxane release (18.8%, p=0.03), but there were no significant changes in PAF-stimulated platelet aggregation. Fasting glucose rose by 1.40±0.29 mmol/l (p=0.002) following EPA and 0.98±0.29 mmol/l (p=0.002) following DHA. Neither EPA nor DHA had any significant effect on HbA1c, fasting serum insulin or C-peptide, insulin sensitivity, stimulated insulin secretion, 24-hr ambulatory blood pressure and heart rate, markers of inflammation, and fibrinolytic or vascular function. Study 2 : This study aimed to examine the influence and causes of increased inflammation on vascular function in subjects recruited for Study 1. Compared with healthy controls (n=17), the diabetic subjects (n=29) had impaired flow-mediated dilatation (FMD) (3.9±3.0% vs 5.5±2.4%, p=0.07) and glyceryl-trinitrate mediated dilatation (GTNMD) (11.4±4.8% vs 15.4±7.1%, p=0.04) of the brachial artery. They also had higher levels of the inflammatory markers C-reactive protein (2.7±2.6 mg/l vs 1.4±1.1 mg/l, p=0.03), fibrinogen (3.4±0.7 g/l vs 2.7±0.3 g/l, p<0.001) and tumor necrosis factor-alpha (20.9±13.4 pg/l vs 2.5±1.7 pg/l, p<0.001). In diabetic subjects, after adjustment for age and gender, leukocyte count was an independent predictor of FMD (p=0.02), accounting for 17% of total variance. Similarly, leukocyte count accounted for 23% (p<0.001) and IL-6 for 12% (p=0.03) of variance in GTNMD. Von Willebrand factor, a marker of endothelial cell activation was correlated with leukocyte count (r=0.38, p=0.04), FMD (r=-0.35, p=0.06) and GTNMD (r=-0.47, p=0.009), whilst P-selectin, a marker of platelet activation was correlated with fibrinogen (r=0.58, p=0.001). Conclusion : EPA and DHA have similar beneficial effects on triglycerides, HDL2 cholesterol and oxidative stress in individuals with Type 2 diabetes and hypertension. However, DHA also increases LDL particle size and reduces collagen-stimulated platelet aggregation and thromboxane release, thus offering more potential than EPA as an anti-thrombotic agent. The beneficial effects of both oils were potentially offset by deterioration in glycaemic control. Neither oil affected blood pressure or vascular function. Longer-term studies with major morbidity and mortality as the primary outcome measures are required to assess the overall benefits and risks of EPA and DHA. The cross-sectional observations from Study 2 are consistent with the hypothesis that impaired vascular function in individuals with Type 2 diabetes and hypertension is at least in part secondary to increased inflammation, with associated endothelial and platelet activation.
108

Potencial antioxidante dos extratos de Moringa oleífera Lamark em sistemas lipídicos de baixa estabilidade oxidativa

Batista, Jaqueline Azevedo Nascimento 25 February 2013 (has links)
Made available in DSpace on 2015-04-17T14:49:26Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3553488 bytes, checksum: c7a68dde18e1eb50115987c8405cadf0 (MD5) Previous issue date: 2013-02-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The species Moringa oleifera Lamarck is a perennial and drought-tolerant plant cultivated as ornamental and medicinal plant. In this study, ethanolic extracts of leaves, flowers, and seed pods of this plant were evaluated for their protective effect against soybean and fish oil oxidation. For this, total extractable phenolics (TEP) were determined by Folin-Ciocalteau method, as well as the antioxidant potential, using the DPPH radical scavenging activity method (RSA-DPPH), iron power reduction (FRAP) and &#946;-carotene/ linoleic acid system. The thermal stability of extracts was measured by thermal analysis (TG / DTA) and the antioxidant effect on soybean and fish oils was investigated by the Rancimat method, pressurized differential scanning calorimetry (P-DSC) and accelerated storage test. The preliminary toxicity assessment of extracts was performed using Artemia salina larvae. The TEP levels in extracts of leaves, flowers and seed pods were (53.69 ± 1.00), (45.85 ± 1.71), (41.75 ± 3.35) and (8.06 ± 0.47) mg GAE / g of extract, respectively. In tests to determine the antioxidant capacity, extract from leaves showed better RSA-DPPH and FRAP and also higher antioxidant activity in the &#946;-carotene/ linoleic acid system. In the thermal stability evaluation, extract from leaves was also more stable than the other extracts. In tests to evaluate the antioxidant effect of extracts, it was found that extract from leaves was more efficient in both oils in Rancimat and P-DSC methods with protective effect equivalent to synthetic antioxidant BHT in soybean oil using the Rancimat method. In the accelerated storage test, it was found that after 16 days of storage, extract from leaves was the most effective in inhibiting the formation of oxidation products in both oils, being more effective than BHT and TBHQ in fish oil. The results of the preliminary toxicity assessment showed low toxicity, suggesting that the extracts may be consumed without health damage. These results suggest that the ethanolic extract of moringa leaves has efficient protective effect when applied to lipid systems of low oxidative stability and could be an alternative source of potential application in the oils and fats industry. / A Moringa oleífera Lamark é uma planta perene e tolerante a seca cultivada como planta ornamental e medicinal. No presente estudo, os extratos etanólicos das folhas, flores, cascas das vagens e sementes desta planta foram avaliados quanto a sua proteção contra a oxidação dos óleos de soja e de peixe. Para isso, foram determinados o teor de fenólicos extraíveis totais (FET) através do método Folin-Ciocalteau e o potencial antioxidante, empregando-se os métodos de sequestro do radical DPPH (RSA-DPPH), poder de redução do ferro (FRAP) e sistema &#946;-caroteno/ácido linoléico. A estabilidade térmica dos referidos extratos foi avaliada através da análise térmica (TG/DTA) e o efeito antioxidante investigado nos óleos de soja e de peixe através dos métodos Rancimat, calorimetria exploratória diferencial pressurizada (PDSC) e teste de estocagem acelerada em estufa. A avaliação preliminar da toxicidade dos extratos foi realizada utilizando larvas de Artemia salina. Os teores FET nos extratos das folhas, flores, casca das vagens e sementes foram (53,69 ± 1,00); (45,85 ± 1,71); (41,75 ± 3,35) e (8,06 ± 0,47) mg GAE/g de extrato, respectivamente. Nos ensaios de determinação da capacidade antioxidante, o extrato das folhas apresentou melhor RSA-DPPH, FRAP e também maior atividade antioxidante no sistema &#946;-caroteno/ácido linoleico. Na avaliação da estabilidade térmica, o extrato das folhas também se mostrou mais estável do que os demais extratos. Nos ensaios de avaliação do efeito antioxidante dos extratos, verificou-se que o extrato das folhas foi o mais eficiente em ambos os óleos nos métodos Rancimat e PDSC, com efeito protetor equivalente ao antioxidante sintético BHT no óleo de soja na técnica Rancimat. No teste de estocagem acelerada em estufa, foi verificado que após 16 dias de armazenamento o extrato das folhas foi o mais eficaz na inibição da formação dos produtos da oxidação primária e secundária em ambos os óleos, sendo mais eficiente do que o BHT e TBHQ no óleo de peixe. Os resultados da avaliação preliminar de toxicidade indicaram uma baixa toxicidade dos extratos, sugerindo que os mesmos podem ser consumidos sem prejuízo à saúde. Estes resultados sugerem que o extrato etanólico das folhas de moringa possui efeito protetor eficiente quando aplicado a sistemas lipídicos de baixa estabilidade oxidativa, podendo vir a ser uma fonte alternativa de potencial aplicação na indústria de óleos e gorduras.
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Concentrado protéico de soja e óleo de soja em rações experimentais para o camarão marinho Litopenaeus vannamei / Soy protein concentrate and soy oil in experimental diets to the marine shrimp Litopenaeus vannamei

Cordeiro Júnior, Evandro Lima January 2011 (has links)
CORDEIRO JÚNIOR, Evandro Lima. Concentrado protéico de soja e óleo de soja em rações experimentais para o camarão marinho Litopenaeus vannamei. 2011. 54 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia de Pesca, Fortaleza-CE, 2011 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-13T15:09:42Z No. of bitstreams: 1 2011_dis_elcodeirojúnior.pdf: 916213 bytes, checksum: bd808548b8b802d6b66ada4e3a7fc8e2 (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-13T15:10:01Z (GMT) No. of bitstreams: 1 2011_dis_elcodeirojúnior.pdf: 916213 bytes, checksum: bd808548b8b802d6b66ada4e3a7fc8e2 (MD5) / Made available in DSpace on 2016-07-13T15:10:01Z (GMT). No. of bitstreams: 1 2011_dis_elcodeirojúnior.pdf: 916213 bytes, checksum: bd808548b8b802d6b66ada4e3a7fc8e2 (MD5) Previous issue date: 2011 / Currently, there are many studies to replace total or part of fishmeal in the artificial feeds by plant protein sources in order to lower costs and greater predictability of production. The study aimed to evaluate the growth performance of juvenile shrimp Litopenaeus vannamei (1.59 ± 0.46 g) reared in the laboratory under controlled conditions for 72 days. They were stored in 50 polyethylene circular tanks of 500 L at the density of 40 shrimp/tank (70 shrimp/m2). Soybean protein concentrate was the main substitute for fish meal and the soybean oil was the main substitute for fish oil. Eight experimental feeds were formulated combining four levels of inclusion of fish meal and two levels of fish oil (120/20, 120/10, 85/20, 85/10, 50/20, 50/10, 0//20 and 0/10). The first number refers to the inclusion of fishmeal (g kg-1) and the second number refers to the inclusion of fish oil (g kg-1). Differences were significant in weekly growth, weight gain, final weight, total feed intake, FCR, yield and PER based on the percentage of inclusion of fishmeal in diets. Survival and ANPU were not significant. Results showed that it is possible to reduce the level of inclusion of fishmeal in the diet of 120 g kg-1 to 85 g.kg-1 and this doesn’t compromise the shrimp growth only if the diet contains at least 10 g.kg -1 of fish oil. If the level of inclusion of fish oil decreases to 10 g kg-1, the minimum inclusion of fish meal, without prejudice, will be subject to 85 g kg-1. There was a reduction in growth rate of L. vannamei when it was removed completely from the fish meal diet. This fact occurred regardless of inclusion level of tested fish oil (20 or 10 g kg-1). Further work is required to evaluate other levels of inclusion, cheap production techniques, alternative ingredients to fish meal etc / Atualmente, há grande esforço de pesquisa no sentido de se substituir, parcial ou totalmente, a farinha de peixe das rações artificiais por fontes protéicas vegetais, visando menores custos, e maior previsibilidade de produção. O presente trabalhou objetivou avaliar o desempenho zootécnico de juvenis do camarão marinho Litopenaeus vannamei (1,59 ± 0,46 g) cultivados em laboratório sob condições controladas durante 72 dias, sendo estocados em 50 tanques circulares de polietileno de 500 L, na densidade de 40 camarões/tanque (70 camarões/m²). No estudo, o concentrado protéico de soja foi o principal substituto da farinha de peixe, e o óleo de soja o principal substituto do óleo de peixe. Oito rações experimentais foram formuladas combinando quatro níveis de inclusão de farinha de peixe e dois níveis de inclusão de óleo de peixe (120/20, 120/ 10, 85/20, 85/10, 50/20, 50/10, 0/20 e 0/10), o primeiro número se refere à inclusão de farinha de peixe em g kg-1 e o segundo número se refere à inclusão de óleo de peixe em g kg-1. Houve diferença significativa no crescimento semanal, peso final, consumo total de ração, FCA, produtividade e TEP em função do percentual de inclusão de farinha de peixe nas dietas, já para sobrevivência e VPP não houve diferença significativa. Pode ser concluído que é possível diminuir o nível de inclusão de farinha de peixe na dieta de 120 g.kg- 1 para 85 g.kg-1 sem comprometer o crescimento dos camarões somente se a dieta contiver, no mínimo, 10 g.kg-1 de óleo de peixe. Se o nível de inclusão de óleo de peixe cair para 10 g kg-1, a inclusão mínima de farinha de peixe sem prejuízo zootécnico será para 85 g kg-1. Houve perda significativa na taxa de crescimento do L. vannamei quando se retirou por completo a farinha de peixe da dieta, independentemente do nível de inclusão de óleo de peixe testado (20 ou 10 g kg-1). Trabalhos futuros são requeridos para avaliar outros níveis de inclusão, técnicas de produção baratas, ingredientes alternativos à farinha de peixe etc
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Suplementação materna com óleo de peixe e efeitos cardiovasculares na prole adulta de ratos submetidos à restrição protéica perinatal / Maternal fish oil supplementation and cardiovascular effects uppon adult rat offspring subjected to perinatal protein restriction

Bianca Martins Gregório 17 January 2007 (has links)
Fêmeas Wistar foram alimentadas durante o período gestacional e a primeira metade da lactação (10 primeiros dias de lactação) com dieta normoprotéica (19 g proteína / Kg dieta) (grupo NP) e dieta restrita em proteínas (5 g proteína / Kg dieta) (grupo LP). Paralelamente a este esquema de alimentação, elas também receberam, diariamente, por gavagem, o óleo de peixe (Fo, rico em ácido graxo poliinsaturado- AGPi n-3). Os filhotes foram subdivididos em 4 grandes grupos: NP, NP-Fo, LP e LP-Fo, sendo acompanhados até os 6 meses de idade, data na qual ocorreu a eutanásia. No momento do sacrifício, o coração foi removido e devidamente preparado para a análise em microscopia de luz e estereologia. A partir do terceiro mês, os animais do grupo LP (ambos os gêneros) exibiram um aumento na pressão arterial sistólica (hipertensão moderada), mantendo esse comportamento até o final do experimento (6 meses de idade). No entanto, a suplementação materna com o Fo foi capaz de minimizar os efeitos da desnutrição sobre a pressão arterial. Não houve diferença significante no índice corporal entre os grupos de mães suplementadas com o Fo. O ventrículo esquerdo do grupo LP (ambos os sexos) demonstrou maior espessura quando comparado ao grupo NP (+25% nos machos, P=0,01, +22% nas fêmeas, P=0,001); entretanto, o grupo LP-Fo manifestou menor espessura quando comparado com o grupo LP (-23% nos machos, P=0,001, -12% nas fêmeas, P=0,02). Os machos do grupo LP apresentaram significativamente menor vascularização intramiocárdica quando correlacionado ao grupo NP (-50%, P=0,01), enquanto os machos do grupo LP-Fo exibiram um incremento de 89% na microcirculação, quando comparados ao grupo LP (P=0,004). Ambos os gêneros do grupo LP manifestaram maior quantidade de fibrose intersticial quando comparados ao grupo NP. Vale ressaltar que a suplementação materna de Fo foi benéfica apenas no grupo LP. Sendo assim, nossos dados sugerem claramente que a suplementação materna com Fo, durante o período perinatal, é capaz de prevenir o remodelamento cardíaco adverso e a hipertensão provocados pela restrição protéica materna in útero e na lactação, tornando-se assim uma opção não farmacológica viável para a prevenção e/ou redução dos danos ocasionados pela programação em humanos. / Female Wistar rats fed in gestation and first 10 lactation days with normal protein diet (19 g protein/kg diet) (NP group) or low-protein diet (5g protein/kg diet) (LP group), also received daily fish oil supplement (Fo, n-3 PUFA rich) during same period. Offspring put in groups NP, NP-Fo, LP, LP-Fo, until sacrifice at 6-mo-old when hearts removed, prepared for light microscopy and stereology. There was mild hypertension in both LP genders from 3- until 6 mo-old. Blood pressure affected by undernutrition was minimized by maternal Fo supplementation. In body index between groups there was no significant difference with maternal Fo supplementation. The left ventricle was thicker in both genders of LP groups compared to counterpart NP groups (+25% in male LP group, P=0.01, +22% in female LP group, P=0.001); however, less thick in LP-Fo groups compared to LP groups (-23% in male LP-Fo group, P=0.001, - 12% in female LP-Fo group, P=0.02). Male LP group offspring had significantly smaller intramyocardial microcirculation than NP group (-50%, P=0.01), while male LP-Fo group had 89% higher microcirculation than LP group (P=0.004). Both gender LP group offspring had significantly higher interstitial fibrosis compared with NP groups. The maternal Fo supplementation has beneficial effects in LP , but not in NP offspring. In conclusion, our data clearly indicate postnatal hypertension and collateral cardiovascular adverse remodeling, programmed by low-protein diet in utero and lactation was prevented by perinatal supplementation with fish oil, n-3 PUFA rich, providing a viable non-pharmacologic option for preventing and/or reducing adverse programming outcomes in human.

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