Nucleotide nutrition in fish: Current knowledge and future applications

Decreased expression of CD200 and CD200 receptor in Alzheimer's disease: A potential mechanism leading to chronic inflammation

Purpose: Concentrative nucleoside transporter (CNT) 1, CNT3, equilibrative nucleoside transporter (ENT) 1, and, to a lesser extent, ENT2, appear to be the transporters responsible for 2′,2′-difluorodeoxycytidine (gemcitabine; Gemzar) uptake into cells. Gemcitabine is used currently in the treatment of pancreatic cancer, but the role of specific nucleoside carrier proteins in gemcitabine cytotoxicity has not been elucidated. Indeed, it is not known which nucleoside transporters are expressed in human pancreas. Experimental Design: In this study we have used four cell lines [pancreatic neoplasia (NP)9, NP18, NP29, and NP31] derived from human pancreatic adenocarcinomas to monitor the pattern of nucleoside transporter expression, and we have heterologously expressed the high-affinity gemcitabine transporter human orthologue (h) CNT1 to monitor its role in drug responsiveness. Results: All of the cell lines take up gemcitabine mostly via the hENT1 transporter, which is expressed at high levels. Reverse transcription-PCR analysis of the other four cloned plasma membrane transporter mRNAs revealed very different expression patterns among NP cell lines, with apparent selective loss or decrease of hCNT mRNAs. NP cells transiently express hCNT1-type Na + -dependent nucleoside transport activity at low/medium cell density but not in confluent cultures. Cells expressing hCNT1 in a more constitutive manner were cloned after stable transfection of hCNT1. Despite high constitutive hENT1 activity, this increased sensitivity to gemcitabine. Conclusion: In summary, human pancreatic adenocarcinoma cells overexpress hENT1, although they retain the ability to express a functional hCNT1 transporter, an isoform that confers sensitivity to gemcitabine.

https://clincancerres.aacrjournals.org/content/clincanres/9/13/5000.full.pdf

Nucleoside Transporter Profiles in Human Pancreatic Cancer Cells Role of hCNT1 in 2′,2′-Difluorodeoxycytidine- Induced Cytotoxicity

Background and aim A decreased adherence to the Mediterranean Diet (MD) may be related to a rise in chronic non-communicable diseases from childhood onward. The aim of this systematic review was to summarize the available literature regarding MD adherence in children and adolescents, and focusing, more specifically, on the association of MD adherence with demographic and anthropometric variables, body composition, lifestyle, and diet adequacy. Methods and results A search of scientific literature was carried out on PUBMED, SCOPUS, Clinical Trials Results, Google Scholar, and British Library Inside for studies published in the last 20 years. Fifty-eight papers were finally included according to the following criteria: MD adherence evaluated through a quantifying score or index, age 2–20 years, sample size >200 participants, observational or intervention studies regarding the general population. The KIDMED index was the most widely used scoring system. MD adherence widely varied within the Mediterranean countries for both children and adolescents, with also large differences among various European countries, while few data are available for non-Mediterranean countries. Most of the eligible studies showed that MD adherence was directly associated with physical activity (and possibly with diet adequacy) and inversely with sedentary behavior, while the results for gender, age, socioeconomic status and weight status were not consistent. Conclusions Further validation of MD indexes in terms of reproducibility and consistency with the MD is needed. At the same time, more prospective cohort and intervention studies may better elucidate the relationships of MD adherence with behavioral and health outcomes.

Adherence to the Mediterranean Diet in children and adolescents: A systematic review.

Few other aspects of food supply and metabolism are of greater biological importance than the feeding of mothers during pregnancy and lactation, and of their infants and young children. Nutritional factors during early development not only have short-term effects on growth, body composition and body functions but also exert long-term effects on health, disease and mortality risks in adulthood, as well as development of neural functions and behaviour, a phenomenon called 'metabolic programming'. The interaction of nutrients and gene expression may form the basis of many of these programming effects and needs to be investigated in more detail. The relation between availability of food ingredients and cell and tissue differentiation and its possible uses for promoting health and development requires further exploration. The course of pregnancy, childbirth and lactation as well as human milk composition and the short- and long-term outcome of the child are influenced by the intake of foods and particularly micronutrients, e.g. polyunsaturated fatty acids, Fe, Zn and I. Folic acid supplementation from before conception through the first weeks of pregnancy can markedly reduce the occurrence of severe embryonic malformations; other potential benefits of modulating nutrient supply on maternal and child health should be further evaluated. The evaluation of dietary effects on child growth requires epidemiological and field studies as well as evaluation of specific cell and tissue growth. Novel substrates, growth factors and conditionally essential nutrients (e.g. growth factors, amino acids, polyunsaturated fatty acids) may be potentially useful as ingredients in functional foods and need to be assessed carefully. Intestinal growth, maturation, and adaptation as well as long-term function may be influenced by food ingredients such as oligosaccharides, gangliosides, high-molecular-mass glycoproteins, bile salt-activated lipase, pre- and probiotics. There are indications for some beneficial effects of functional foods on the developing immune response, for example induced by antioxidant vitamins, trace elements, fatty acids, arginine, nucleotides, and altered antigen contents in infant foods. Peak bone mass at the end of adolescence can be increased by dietary means, which is expected to be of long-term importance for the prevention of osteoporosis at older ages. Future studies should be directed to the combined effects of Ca and other constituents of growing bone, such as P, Mg and Zn, as well as vitamins D and K, and the trace elements F and B. Pregnancy and the first postnatal months are critical time periods for the growth and development of the human nervous system, processes for which adequate substrate supplies are essential. Early diet seems to have long-term effects on sensory and cognitive abilities as well as behaviour. The potential beneficial effects of a balanced supply of nutrients such as I, Fe, Zn and polyunsaturated fatty acids should be further evaluated. Possible long-term effects of early exposure to tastes and flavours on later food choice preferences may have a major impact on public health and need to be further elucidated. The use of biotechnology and recombinant techniques may offer the opportunity to include various bioactive substances in special dietary products, such as human milk proteins, peptides, growth factors, which may have beneficial physiological effects, particularly in infancy and early childhood.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/3D543771FDD804529A80B473FF6BC65D/S0007114598001184a.pdf/div-class-title-growth-development-and-differentiation-a-functional-food-science-approach-div.pdf

Growth, development and differentiation: a functional food science approach

Objective: The Mediterranean diet is considered one of the healthiest dietary models. Recent changes in the actual Mediterranean diet include a reduction in energy intake and a higher consumption of foods with low nutrient density (e.g. soft drinks, candy, sweets, etc.). In Spain, in association with cultural and lifestyle changes, there has been a reduction in the intake of antioxidants and vitamins, an increase in the proportion of SFA and a decrease in the consumption of fibre, among other changes. Children and adolescents may be the age groups with the most deteriorated Mediterranean diet. The current paper presents the results of applying the Mediterranean Diet Quality Index for children and adolescents (KIDMED) to a large sample of Spanish schoolchildren. Design: Data from questionnaires were used to calculate the KIDMED index. Setting: Granada, Southern Spain. Subjects: Schoolchildren (n 3190) aged 8‐16 years. Results: Among the 8‐10-year-olds, the KIDMED index classification was ‘good’ in 48?6% of the population, ‘average’ in 49?5% and ‘poor’ in 1?6%. Among the 10‐16-year-olds, the KIDMED index classification was good in 46?9% of the population, average in 51?1% and poor in 2?0%. Conclusions: The nutritional behaviour of the present population of schoolchildren is similar to that found in the earlier KIDMED study.

/pdf/evaluation-of-the-mediterranean-diet-quality-index-kidmed-in-3hx3o52n3c.pdf

Evaluation of the Mediterranean Diet Quality Index (KIDMED) in children and adolescents in Southern Spain

Nutritional regulation of nucleoside transporter expression in rat small intestine.

https://www.gastrojournal.org/article/S0016-5085(96)00264-8/pdf

Deprivation of dietary nucleotides decreases protein synthesis in the liver and small intestine in rats.

Previous studies in very young rats have shown that dietary nucleotides improve small intestine repair after injury or malnutrition. To investigate the potential effect of nucleotides in old rats, which have a diminished capability for intestinal repair, 17-mo-old rats were deprived of food for 5 d and then fed a nucleotide-free diet or a nucleotide-supplemented diet for 3 or 6 d. Intestinal jejunal and ileal mucosal weight, protein and DNA were evaluated as intestinal growth markers, and brush-border maltase, sucrase, lactase and aminopeptidase activities were evaluated as intestinal differentiation markers. The adenine nucleotide pool and the adenylate energy charge were also evaluated as indices of nucleotide availability. Food deprivation significantly decreased mucosal growth markers as well as differentiation markers in both jejunum and ileum. The ATP pool was also significantly depressed, but the adenylate energy charge was not significantly altered. To a certain extent, refeeding restored the losses, but in the rats that were fed the nucleotide-free diet, the restoration of the jejunum was significantly slower and the restoration of the ileum differentiation markers was incomplete compared with the rats fed the nucleotide-supplemented diet. The results suggest that dietary nucleotide intake in the elderly may accelerate the normal physiological intestinal response to refeeding after food deprivation.

M.A. Ortega

Papers

Evaluation of the Mediterranean Diet Quality Index (KIDMED) in children and adolescents in Southern Spain

Nutritional regulation of nucleoside transporter expression in rat small intestine.

Deprivation of dietary nucleotides decreases protein synthesis in the liver and small intestine in rats.

Dietary nucleotides accelerate intestinal recovery after food deprivation in old rats.

Characterization of human cd200 glycoprotein receptor gene located on chromosome 3q12-13.