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Dietary Requirement (dietary + requirement)
Selected AbstractsGene response elements, genetic polymorphisms and epigenetics influence the human dietary requirement for cholineIUBMB LIFE, Issue 6 2007Steven H. Zeisel Abstract Recent progress in the understanding of the human dietary requirement for choline highlights the importance of genetic variation and epigenetics in human nutrient requirements. Choline is a major dietary source of methyl-groups (one of choline's metabolites, betaine, participates in the methylation of homocysteine to form methionine); also choline is needed for the biosynthesis of cell membranes, bioactive phospholipids and the neurotransmitter acetylcholine. A recommended dietary intake for choline in humans was set in 1998, and a portion of the choline requirement can be met via endogenous de novo synthesis of phosphatidylcholine catalyzed by phosphatidylethanolamine N-methyltransferase (PEMT) in the liver. Though many foods contain choline, many humans do not get enough in their diets. When deprived of dietary choline, most adult men and postmenopausal women developed signs of organ dysfunction (fatty liver, liver or muscle cell damage, and reduces the capacity to handle a methionine load, resulting in elevated homocysteine). However, only a portion of premenopausal women developed such problems. The difference in requirement occurs because estrogen induces expression of the PEMT gene and allows premenopausal women to make more of their needed choline endogenously. In addition, there is significant variation in the dietary requirement for choline that can be explained by common polymorphisms in genes of choline and folate metabolism. Choline is critical during fetal development, when it alters DNA methylation and thereby influences neural precursor cell proliferation and apoptosis. This results in long term alterations in brain structure and function, specifically memory function. IUBMB Life, 59: 380 - 387, 2007 [source] The significance of vitamin D for fish: a reviewAQUACULTURE NUTRITION, Issue 1 2010E.-J. LOCK Abstract Fish store large quantities of vitamin D in their liver and fat tissues, including the fat associated with muscle, and this makes fish an important dietary source of vitamin D. Fish do not synthesize vitamin D and are fully dependent on dietary sources to meet their requirement. Under natural circumstances planktonic vitamin D accumulates in the aquatic food chain. In aquaculture, formulated diets are used and vitamin D intake can be manipulated. The minimum dietary requirement for vitamin D has been established in several fish species. The role of vitamin D in fish physiology is still enigmatic. Till the 1970s there was consensus that fish accumulate but not metabolize vitamin D. There is substantial evidence now, four decades later, that fish have a vitamin D endocrine system with similar functions as in mammals. We here summarize the major characteristics of the fish vitamin D endocrine system. The hydroxylation of vitamin D to more polar metabolites, their plasma levels and protein-bound transport in blood plasma will be discussed. The vitamin D receptor profile, receptor distribution and responses to vitamin D are reviewed for the key target tissues (gill, intestine, kidney and bone). We will address the classical slower actions through transcription factors as well as the faster G-protein coupled (membrane) receptor mediated effects. We then review the dietary requirement of vitamin D in aquaculture and address some lesser known functions of the vitamin D endocrine system. [source] Effect of EPA/DHA ratios on the growth and survival of Galaxias maculatus (Jenyns, 1842) larvae reared under different salinity regimesAQUACULTURE RESEARCH, Issue 9 2010Patricio Dantagnan Abstract Despite the importance of certain highly unsaturated fatty acids in osmotic regulation, few studies have been addressed to determine the essential fatty acid requirements for a given species cultured under different salinities. As Galaxias maculatus is a diadromic species, the present study aimed to determine the effect of salinity on the optimum dietary EPA/docosahexaenoic (DHA) ratio for survival and growth during the larval stages. Larvae were fed for 20 days with rotifers containing two different EPA/DHA ratios (low: 0.64 and high: 2.18) at three different salinities (0, 10 and 15 g L,1). The results of this study showed a marked effect of water salinity on larval dietary lipid utilization in G. maculatus larvae. These results suggested that G. maculatus larvae reared at higher salinities may have a higher dietary requirement for DHA, whereas larvae reared at 0, showed higher requirements for EPA. The overall results of the present study indicate that even small changes in salinity can determine the optimum dietary EPA/DHA ratio and the quantitative essential fatty requirements of fish. This may have important repercussions and affect the rearing performance of G. maculatus cultured under different salinities. [source] Phosphorus requirement of Catla (Catla catla Hamilton) fingerlings based on growth, whole-body phosphorus concentration and non-faecal phosphorus excretionAQUACULTURE RESEARCH, Issue 2 2009Krishna Sukumaran Abstract A 120-day feeding trial was conducted to determine the dietary requirement of phosphorus for Indian major carp, catla (Catla catla) fingerlings. Four hundred and eighty fingerlings (mean body weight: 4.23±0.87 g) were randomly distributed among eight treatment groups with three replicates each. Eight isonitrogenous and isocaloric semi-purified diets (crude protein: 35% and crude lipid: 8.5%) were formulated with graded levels of phosphorus using KH2PO4 (T1: control, 0.1%; T2: 0.3%; T3: 0.5%; T4: 0.7%; T5: 0.9%; T6: 1.1%; T7: 1.3%; T8: 1.5%) and fed to the respective groups. Twenty fish were stocked in 150 L plastic tanks and fed to apparent satiation twice a day. Specific growth rate (SGR) significantly (P<0.05) increased with increasing dietary phosphorus concentration from 0.73% to 1.27%, after which there was a slight decline in growth at 1.1% available phosphorus (aP) and remained constant thereafter. The quadratic broken-line model based on growth was Y=317.5,581(0.64,x) (0.64,x); R2=0.73. Moisture and crude protein contents of whole body were similar among all the treatments. However, the ether extract in T1 group was significantly (P<0.05) higher than all the other treatments. The whole-body phosphorus content increased significantly (P<0.05) with an increase in phosphorus in the diets. The one-slope broken-line model based on whole-body phosphorus concentration was Y=4.07,1.63 (0.71,x); R2=0.48. The one-slope broken-line model for non-faecal phosphorus excretion as inorganic phosphorus (Pi) for 24 h revealed a trend of Y=12.67+73.96 (x,0.6); R2=0.81. Minimum aP requirements based on weight gain (%), whole-body phosphorus content and phosphorus excretion were 0.64%, 0.71% and 0.6%, respectively. Hence, the dietary aP requirement of catla fingerlings ranges from 0.6% to 0.71%. [source] Formulation of low phosphorus loading diets for carp (Cyprinus carpio L.)AQUACULTURE RESEARCH, Issue 2001P Jahan Abstract This study focuses on reducing total phosphorus loading (T-P) from carp culture through improved feed formulation. Since phosphorus (P) contained in fish meal (FM) mainly in the form of tricalcium phosphate is not available to carp, which lack a stomach, the reduction of FM from their diets is effective for lowering T-P. Thus in this experiment, six diets (crude protein < 35%, digestible energy > 3.5 kcal g,1) were designed by substituting FM (10%,25%) with alternate protein ingredients such as poultry feather meal (PFM; 5%,10%), blood meal (BM; 5%,7%) and defatted soybean meal (dSBM; 4%,9%). All diets followed the Kasumigaura ,Feed Standard'. The total dietary P was 1.0%,1.4% and water extractable P available to carp was 0.66%,0.71%, the levels meeting the dietary requirement of carp. A feeding trial was conducted with juvenile carp (4.6 ± 0.7 g) for 12 weeks at a mean water temperature of 23.7°C. The T-P loading from fish fed the different diets was estimated based on absorption and retention of dietary P. Growth performance corresponded to increasing levels of FM inclusion, being highest in the fish fed 25% FM diet; however, the decrease in T-P was achieved at the lower FM levels. The T-P (based on P retention) ranged from 8.9 to 11.7 kg t,1 production, much lower than that from the commercial diets (9.1,26.4 kg t,1 production). These results indicated that the reduction of FM levels in carp diets to 15%,20% through the combined use of PFM, BM and dSBM effectively lowered T-P. Moreover, the formulated diets were also found to be better than commercial diets in lowering the N loading from carp culture. [source] Ascorbic acid and reproduction in fish: endocrine regulation and gamete qualityAQUACULTURE RESEARCH, Issue 8 2001K Dabrowski Abstract High ascorbic acid concentrations have been associated with gonad and brain tissues in teleost fishes. Although a direct dietary effect on gamete quality has been given some attention recently, the mechanism of action of ascorbate along the cascade of reproductive events in the hypothalamus, pituitary and gonads has not been defined. Data relating to gamete production and quality, as well as a possible protective role for ascorbate against cumulative genetic defects during gametogenesis and congenital malformation during gestation (embryonic development) is reviewed. It is suggested that the gonad growth in response to gonadotropin stimulation involves direct interaction between catecholamines and steroid hormones and their receptor sites. This interaction acts as a regulatory mechanism of ascorbate absorption, transfer and metabolism (degradation and/or renewal) in the reproductive system. We conclude that ascorbic acid is a leading nutrient in reproductive tissue functions and further research is needed on: (1) its antioxidant effect on gametes' (sperm and ova) capacity to prevent DNA damage occurring prior to (endogenous) and after spawning (environmental insults); (2) its dietary requirement to optimize survival and physiological recovery in multiple spawners; (3) the integration mechanism of ascorbic acid action as part of the overall endocrine regulation of neurohormonal,hormonal pathway in fish reproduction; and (4) the possible role for ascorbate in regulating fish maturation and/or infertility in the presence of enhanced UV-radiation or conditions of intensive aquaculture (hypoxia, oxygen supersaturation, dietary pro,, and antioxidants). [source] Antioxidant supplementation and nasal inflammatory responses among young asthmatics exposed to high levels of ozoneCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 2 2004J. J. SIENRA-MONGE SUMMARY The inflammatory response to ozone in atopic asthma suggests that soluble mediators of inflammation are released in response to oxidant stress. Antioxidants may alleviate additional oxidative stress associated with photochemical oxidant pollution. This study investigates the impact of antioxidant supplementation on the nasal inflammatory response to ozone exposure in atopic asthmatic children. We conducted a randomized trial using a double-blinded design. Children with asthma (n = 117), residents of Mexico City, were given randomly a daily supplement of vitamins (50 mg/day of vitamin E and 250 mg/day of vitamin C) or placebo. Nasal lavages were performed three times during the 4-month follow-up and analysed for content of interleukin-6 (IL-6), IL-8, uric acid and glutathione (GSx). IL-6 levels in the nasal lavage were increased significantly in the placebo group after ozone exposure while no increase was observed in the supplement group. The difference in response to ozone exposure between the two groups was significant (P = 0·02). Results were similar for IL-8, but with no significant difference between the groups (P = 0·12). GSx decreased significantly in both groups. Uric acid decreased slightly in the placebo group. Our data suggest that vitamin C and E supplementation above the minimum dietary requirement in asthmatic children with a low intake of vitamin E might provide some protection against the nasal acute inflammatory response to ozone. [source] The Evolution of Research in Family and Consumer Sciences: Food, Nutrition, and HealthFAMILY & CONSUMER SCIENCES RESEARCH JOURNAL, Issue 2 2001Eleanor D. SchlenkerArticle first published online: 2 JUL 200 Changing perspectives in food, nutrition, and health are bringing new research opportunities. Knowledge that nutrients and other food substances prevent chronic disease expanded the study of dietary requirements beyond merely obviating deficiency. Government policy makers mandate food guidance programs to enable consumers to choose foods that are culturally appropriate yet support health. Intervention strategies leading to suitable food behavior are needed to address the rising health costs associated with aging and chronic diseases. Functional foods carrying added health benefits have gripped the attention of food producers and consumers, yet much is to be learned regarding long term effects. FCS professionals are uniquely qualified to study not only the theoretical bases of these issues but also their impact on the physical and psychosocial well-being of families. Research methods and applications must be incorporated at all academic levels to prepare FCS professionals to meet the research opportunities and challenges ahead. [source] Sex differences in nutrient-dependent reproductive ageingAGING CELL, Issue 3 2009Alexei A. Maklakov Summary Evolutionary theories of aging predict that fitness-related traits, including reproductive performance, will senesce because the strength of selection declines with age. Sexual selection theory predicts, however, that male reproductive performance (especially sexual advertisement) will increase with age. In both bodies of theory, diet should mediate age-dependent changes in reproductive performance. In this study, we show that the sexes exhibit dramatic, qualitative differences in age-dependent reproductive performance trajectories and patterns of reproductive ageing in the cricket Teleogryllus commodus. In females, fecundity peaked early in adulthood and then declined. In contrast, male sexual advertisement increased across the natural lifespan and only declined well beyond the maximum field lifespan. These sex differences were robust to deviations from sex-specific dietary requirements. Our results demonstrate that sexual selection can be at least as important as sex-dependent mortality in shaping the signal of reproductive ageing. [source] A2. The carer's perception of dietitians' advice and its impact on the management of patients receiving haemodialysisJOURNAL OF HUMAN NUTRITION & DIETETICS, Issue 5 2000M. A. Rezaie Background Patients with end stage renal disease and their carers suffer many changes in their daily life style as a result of haemodialysis (HD) treatment. Information and education concerning the management of dietary requirements and restrictions for renal patients should be aimed at both patients and their carers. Aim This study investigated the impact of dietitians' involvement and advice on the carers' ability to manage patients' dietary/fluid requirements. Method A total of 36 carers of renal patients receiving unit haemodialysis treatment were randomly recruited into this study from a hospital in Cardiff, Wales. All the carers completed the Haemodialysis carers questionnaire (HCQ), specifically designed for this study, delivered to them in the outpatient clinic by the dietitian. Results Of the 36 carers, 22 (61%) were female, six (16.7%) were male and eight (22%) did not report their gender. Thirteen (36%) of the carers were between the ages of 20,54 years and 23 (64%) were 55 years of age and older. Twenty-six (72%) of the carers involved in this study were spouses and 34 (94.4%) of the carers lived with the patient. The mean duration of haemodialysis treatment for the patient was found to be 20 months. The results indicated that although the majority of the carers were informed about patients' dietary and fluid restrictions, 45% had not received any dietary information. Dietitians' one-to,one interactions with the carer was the most effective way of providing information in enabling them to better manage the patient compared to other methods such as leaflet and information packs (P = 0.01). The majority of the carers knew how to contact the renal dietitian, however, many did not (P = 0.001). Almost all the carers considered receiving information about the purpose of HD, feed back on the patients' condition, fluid/dietary restriction and details of available community resources as very important. Those carers who had the benefit of a dietitian's involvement believed that their advice was very helpful and enabled them to cope better with the management and complications of patient fluid and dietary requirements (P < 0.02). Strong correlations were found (rs = 0.67; P < 0.01) between the amount of information received by the carers and the level of the carers satisfaction with this information. In contrast, there were no significant correlations between the amount of information received by the carers and different aspects of managing the patients' diet, because 45% of the carers received none or little information. Conclusions Dietitians should involve the carers in the management of HD patient's dietary/fluid requirements and restrictions in order to provide better quality of care and quality of life for both the patient and the carer. [source] Amino acid composition of Arctic charr, Salvelinus alpinus (L.) and the prediction of dietary requirements for essential amino acidsAQUACULTURE NUTRITION, Issue 4 2007R. GURURE Abstract Embryo somatic tissues, non-somatic yolk-sac materials, and whole, individual fingerlings (age 0+) of Arctic charr, Salvelinus alpinus (L.), as well as a commercial trout diet, were analysed for a wide spectrum of amino acids. Analytical material consisted of prefeeding swim-up fry that were separated into discrete yolk sac and somatic embryo tissue samples. Amino acid concentrations in fry somatic tissue and whole fingerlings were generally very similar to each other, but were lower than those measured in yolk materials. Higher correlations were observed between the majority of specific amino acid concentrations in the trout diet when compared with fingerling data (r2 = 0.91) and fry somatic tissue data (r2 = 0.89), than when correlated with fry yolk sac material (r2 = 0.76). These results indicate that the essential amino acid profiles of fry somatic tissue and whole fingerlings are closer to that of a commercial feed than they are to the endogenous profiles found in the embryonic yolk sac material itself. The dietary ratios of individual essential amino acids were also compared with the total essential amino acid concentrations (A/E ratios) in whole fingerling tissues, and these ratios could be used to accurately estimate the apparent essential amino acid requirements of Arctic charr. The rationale for using carcass amino acid composition data to estimate the dietary essential amino acid requirements of Arctic charr is discussed. [source] Biochemical composition of the wild and cultured seahorses, Hippocampus kuda Bleeker and Hippocampus trimaculatus LeachAQUACULTURE RESEARCH, Issue 6 2009Qiang Lin Abstract The biochemical composition of wild and cultured seahorses Hippocampus kuda Bleeker and Hippocampus trimaculatus Leach was analysed in this study. The crude protein contents (% dry weight) of wild seahorses were high: 72.7±2.5% in H. kuda and 78.5±4.2% in H. trimaculatus. The crude lipid contents (% dry weight) of wild and cultured seahorses (1.1±0.1 vs. 1.4±0.2 for H. kuda and 1.2±0.1 vs. 1.2±0.2 for H. trimaculatus) were low and did not differ significantly (F3, 12=1.461, P=0.12). The essential amino acids and flavour-enhancing amino acids in wild seahorses were higher than those in cultured seahorses, although the essential amino acid index in wild and cultured H. kuda and H. trimaculatus were generally low. The total amino acid content decreased with growth in cultured H. trimaculatus (F3, 12=14.927, P<0.05). The poly-unsaturated fatty acid (PUFA) contents in wild and cultured H. kuda and H. trimaculatus were 21.69%, 37.72%, 21.39% and 33.89% respectively. The fatty acid content in seahorses first decreased and then increased with growth both in wild and in cultured H. trimaculatus. The PUFA/saturated fatty acid ratio was 1.31 in cultured H. kuda and 0.87 in cultured H. trimaculatus. The trace metal concentrations in the wild seahorses were relatively low. The results presented in this study provide biochemical information necessary for understanding the medicinal value of H. kuda and H. trimaculatus and for elucidating the potential dietary requirements for their culture. [source] | ||||||||||||||||