Avaliação do balanço nitrogenado e aparecimento de nitrogênio uréico como marcadores de catabolismo, infecção e mortalidade em pacientes com lesão renal aguda em diálise

Pós-graduação em Fisiopatologia em Clínica Médica - FMB

Nutritional aspects of food extrusion: a review

Extrusion cooking, as a multi-step, multi-functional and thermal/mechanical process, has permitted a large number of food applications. Effects of extrusion cooking on nutritional quality are ambiguous. Beneficial effects include destruction of antinutritional factors, gelatinisation of starch, increased soluble dietary fibre and reduction of lipid oxidation. On the other hand, Maillard reactions between protein and sugars reduce the nutritional value of the protein, depending on the raw material types, their composition and process conditions. Heat-labile vitamins may be lost to varying extents. Changes in proteins and amino acid profile, carbohydrates, dietary fibre, vitamins, mineral content and some non-nutrient healthful components of food may be either beneficial or deleterious. The present paper reviews the mechanisms underlying these changes, as well as the influence of process variables and feed characteristics. Mild extrusion conditions (high moisture content, low residence time, low temperature) improve the nutritional quality, while high extrusion temperatures (200 °C), low moisture contents (<15%) and/or improper formulation (e.g. presence of high-reactive sugars) can impair nutritional quality adversely. To obtain a nutritionally balanced extruded product, careful control of process parameters is essential.

Diet, nutrition and the prevention of chronic diseases : report of a Joint WHO/FAO Expert Consultation

This report examines the science base of the relationship between diet and physical activity patterns and the major nutrition-related chronic diseases. Recommendations are made to help prevent death and disability from major nutrition-related chronic diseases.

Effects of irrigation and nitrogen levels on qualitative and nutritional aspects of fig-trees (Ficus carica L.)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Dietary and nutritional aspects of tooth wear

There is a general perception that the problem of tooth wear is increasing due to elements of the modern diet and due to increased retention of dentition into older age. Tooth wear encompasses erosion, abrasion and attrition of dental tissues – these often co-exist – yet in general, erosion is of more significance to the young and attrition is of more significance to the older population. Diet plays a significant role in the aetiology of tooth wear and likewise advanced tooth wear in older age may impose dietary restrictions with consequences for dietary intake and nutritional status. There is a need to increase the awareness of the disease of tooth wear and the associated nutritional problems. At present, the aetiology of tooth wear is poorly understood – especially with respect to the role of diet. Clearer information on how best to measure and monitor the incidence and prevalence is needed in order to obtain longitudinal data on trends in tooth wear and to monitor the factors that contribute to this condition. These issues will be addressed in the following presentations: 1) What is tooth wear? Aetiology, measurement and monitoring, 2) The role of diet in the aetiology of dental erosion, 3) Groups at increased risk of tooth wear: Eating disorders, ‘dieters' sportsmen and those with impairments, 4) Tooth wear in older adults: nutritional implications. In summary this symposium seeks to: 1) increase awareness of the disease of tooth wear, and its associated nutritional problems 2) increase understanding of the aetiology of tooth wear, especially the dietary role, 3) provide information on how to measure and monitor tooth wear, 4) highlight future research requirements in the area of tooth wear and diet.

Nutritional aspects of cancer

DUE TO COPYRIGHT RESTRICTIONS ONLY AVAILABLE FOR CONSULTATION AT ASTON UNIVERSITY LIBRARY AND INFORMATION SERVICES WITH PRIOR ARRANGEMENT

Ontogeny of Solea senegalensis: digestive system and nutritional aspects

Tese de dout., Faculdade de Ciências do Mar e Ambiente, Univ. do Algarve, 2003

Evaluation of yield parameters and nutritional aspects of different strains of oyster (Pleurotus ostreatus) mushroom

The present study investigates the comparison between three different strains of oyster mushroom Pleurotus ostreatus (oyster (local), WC-537, WC-522) regarding to their yield and nutritional aspects. Four different kinds of substrates (corncob, wheat straw, rice straw, and sugarcane bagasse) were used for the growth of oyster. Oyster strain on corncob was found to be the fast mycelial run in comparison with WC-537 and WC-522. WC-522 on sugarcane bagasse showed the slowest mycellial run. Highest number of flushes was produced by oyster strain on each substrate. Number of days for period between flushes for oyster and WC-537 was about equal on corn cob, wheat straw and rice straw i.e. 4-6 days. Number of days taken for maturation of fruiting bodies of oyster and WC-537 was almost equal 6-7 days. In terms of nutritional aspects all strains have almost the same amount of moisture, fat, ash, fiber and protein with small variation. All the strains have protein content of about 20% by weight.

Effect of dietary arachidonic acid and n-3 polyunsaturated fatty acids on the production of eicosanoids

The major polyunsaturated fatty acid (PUFA) in the western diet is linoleic acid (LA), which is considered to be the major source of tissue arachidonic acid (AA), the principal precursor for the vaso-active eicosanoids via the cyclooxygenase enzymatic pathway. However, dietary AA may contribute significantly to tissue levels of AA in humans, leading to an increase in the production of eicosanoids, particularly the platelet aggregating, vasoconstricting, thromboxane (TXA2), hence increasing thrombosis risk. The aims of this study were to determine the extent to which dietary AA contributed to prostacyclin (PGI2) and TXA2 production in vivo and whether dietary long chain (LC) n-3 PUFA have a modulating influence on the metabolism of AA to these vaso-active eicosanoids. A gas chromatography -mass spectrometry (GCMS) method for urinary PGI2-M determination and a tandem GCMS/MS method for urinary TXA2-M determination were perfected for use within our laboratory (with the assistance of Dr Howard Knapp, University of Iowa and Professor Reinhard Lorenz, Ludwig Maximilian's University, Munich, respectively). An initial animal study compared the in vitro production of PGI2 by aorta segments with the whole body in vivo production of PGI2 in rats fed ethyl arachidonate or the ethyl ester of eicosapentaenoic acid (EPA), at levels many times higher than encountered in human diets. During AA feeding both measures of PGI2 increased, although in vitro TXA2 production was not affected. EPA feeding lowered in vitro TXA2 and in vivo PGI2. Prior to determining the effects of AA and LC n-3 PUFA in humans, a study was carried out to determine the AA and LC n-3 PUFA content of foods and from these, an estimate of the mean daily intake of AA and other LC PUFA. Eggs, organ meats and paté were found to be the richest sources of AA. Of the meat and fish analysed, white meat was found to be relatively rich in AA but poor in LC n-3 PUFA. Lean red meat, particularly kangaroo had similar LC n-3 PUFA and AA content. Fish, although rich in AA, had extremely high levels of LC n-3 PUFA. The calculated mean daily intakes of AA in Australian adults was 130mg (males) and 96mg (females). For total LC n-3 PUFA intake, the mean daily values were 247mg (males) and 197mg (females). Two human pilot studies involving dietary intervention trials examined the effects of dietary AA and AA plus long chain n-3 PUFA on thrombosis risk, gauged by the change in the ratio of PGI2 / TXA2 as well as alterations to other recognised risk factors, such as lipoprotein lipids and platelet aggregation. The desired dietary amounts of AA and LC n-3 PUFA were achieved in the first study by combining food items with known levels of each fatty acid. In the second study, where a diet with approximately equal quantities of AA and LC n-3 PUFA was being examined, kangaroo meat was consumed, following a low-fat vegetarian diet used as a baseline. Diets rich in AA alone (~500mg/day) increased plasma phospholipid (PL) AA levels, PGIi and TXA2 production. When foods containing equal quantities of AA and EPA (∼500mg/day of each) were fed to subjects PGI2 increased, with no change in TXAs production. Low fat vegetarian diets lowered PGI2 production, the level of which was reestablished by an AA rich diet (∼300mg AA/day + ∼260mg/day LC n-3 PUFA) of kangaroo meat. However, TXA2 production was not altered. A final, larger human dietary intervention trial then examined the effects of diets relatively rich in AA alone, AA plus LC n-3 PUFA and LC n-3 PUFA, on the ratio of PGI2/TXA2- The dietary sources of these fatty acids were white meat, red meat and fish, respectively. Each contained a mean level of AA of ∼140mg/day, with varying LC n-3 PUFA levels (59, 161 and 3380mg/day, respectively). Neither meat diet altered PGI2 or TXA2 production significantly, despite increasing serum PL AA levels. The fish diet resulted in a decrease in the serum and platelet PL AA/EPA ratio and TXA2 production, thus increasing the PGI2 / TXA2 ratio. These results would indicate that stores of AA in the body are sufficiently high to have effectively saturated the cyclooxygenase pathway for production of both PGI2 and TXA2, thus making any small change in the plasma level of AA due to 'normal' dietary levels, inconsequential. However, as seen in the rat study and the two pilot studies higher dietary levels of AA can increase both PGI2 and TXA2 production. Increases in platelet levels of EPA and DHA were associated with a decrease in TXA2 production, or the maintenance of a constant TXA2 level, while AA tissue levels and PGI2 production increased. This suggests a possible inhibitory effect of LC n-3 PUFA on the metabolism of AA to TXA2, particularly in platelets. From these short term studies, conducted over 2-3 week periods, it can be concluded that diets rich in lean meats can raise plasma AA levels but do not affect TXA2 or PGI2 production, hence are not pro-thrombotic. Diets rich in long chain n-3 PUFA from fish, raise plasma EPA and DHA levels, lower TXA2 production and are anti-thrombotic. Diets which combine equal quantities of AA and LC n-3 PUFA appear to increase PGI2 production while keeping TXA2 production constant. In order for these LC PUFA to have a significant effect on eicosanoid production the dietary intake of these fatty acids through foods such as red meat or white meat would have to be higher than average current Australian consumption levels.