bluuebunny/crossref_metadata_2025 huggingface dataset:
Reduced thymocyte proliferation but not increased apoptosis as a possible cause of thymus atrophy in iron-deficient mice
Authors: Kuvibidila Solo R. , Porretta Connie , Baliga B. Surendra , Leiva Lily E.
Published: May 2008

Iron deficiency induces thymus atrophy in laboratory animals and very likely in humans by unknown mechanisms. The atrophy is associated with impaired cell-mediated immunity. In this study, we tested the hypothesis that thymus atrophy is a result of increased apoptosis and reduced thymocyte proliferation. Thymocytes were obtained from twenty-seven control, twenty-seven pairfed, twenty-seven iron-deficient (ID) mice; twelve and fourteen ID mice that received the control diet (0·9 mmol/kg versus 0·09 mmol/kg for the ID diet) for 1 d (repletion, R1) and 3 d (R3), respectively. Cell cycle analysis and apoptosis were studied by flow cytometry using propidium iodide staining and terminal deoxyuridine nick end labeling of DNA breaks assay respectively. When mice were killed, haemoglobin, haematocrit, and liver iron stores of ID, R1, and R3 mice were 25–40 % of those of control and pairfed mice (P<0·01). Absolute and relative thymus weights and thymocyte numbers were 19 to 68 % lower in ID, R1, and R3 than in control and pairfed groups (P<0·05). We found no significant difference among groups in the percentage of cells undergoing apoptosis. A higher percentage of thymocytes from ID and R1 mice than those of control, pairfed, and R3 mice were in the resting phase of the normal cell cycle (P<0·05). Conversely, a lower percentage of thymocytes from ID and R1 mice than those from control, pairfed, and R3 mice were in the DNA synthesis phase and late phase of DNA synthesis and onset of mitosis (G2-M) (P<0·05). Indicators of iron status positively correlated (r 0·3 to 0·56) with the percentage of thymocytes in the G2-M phase (P<0·05). Results suggest that reduced cell proliferation but not increased apoptosis is the cause of thymus atrophy associated with iron deficiency.
Red wine raises plasma HDL and preserves long-chain polyunsaturated fatty acids in rat kidney and erythrocytes
Authors: Araya Jaulia , Rodrigo Ramón , Orellana Myriam , Rivera Gonzalo
Published: May 2008

The effects of red wine and ethanol on plasma lipoproteins and the fatty acid composition of kidney lipids and erythrocytes phospholipids were studied. Lipid peroxidation is one of the main deleterious effects of oxidant attack on biomolecules, due to the disruption of the structural integrity of membranes. The vulnerability of the kidney to oxidative damage has been partly attributed to its high content of long-chain polyunsaturated fatty acids. Antioxidants, such as flavonoids, would be a means of reducing the risk of oxidative damage to membranes. Nutritional sources rich in antioxidants, including those provided by wine, are expected to attenuate the effects of oxidative challenges. Adult rats were fed red wine rich in flavonols, ethanol (125 ml/l), or alcohol-free red wine. The control group drank water. After 10 weeks, blood samples served to measure plasma lipoproteins and antioxidant capacity. Kidney lipids and erythrocyte phospholipids were extracted. The samples were assayed by GLC. Energy intake did not differ between all the groups, but the weight gain of the ethanol group was less than the other three groups. Blood HDL and triacylglycerols were increased by both ethanol and red wine. Ethanol decreased arachidonic and docosahexaenoic acids in both kidney lipids and erythrocyte phospholipids, as compared with either water, red wine or alcohol-free red wine groups. These results indicate that non-alcoholic components of red wine could contribute to avoiding the unfavourable effects of ethanol on plasma lipoproteins, kidney lipids and membrane erythrocyte phospholipids.
In vivomeasurement of lipogenesis in ruminants using [1-14C]acetate
Authors: Greathead H. M. R. , Dawson J. M. , Scollan N. D. , Buttery P. J.
Published: May 2008

A method for the measurement of the rate of lipogenesis in ruminants using a continuous intravenous infusion of [1-14C]acetate and measuring the rate of [1-14C]acetate incorporation into adipose tissue lipid was evaluated. Subcutaneous adipose tissue samples obtained by biopsy over the course of a 6 h continuous intravenous infusion of [1-14C]acetate into a wether and a steer maintained in a ‘metabolic steady state’ demonstrated that the incorporation of [1-14C]acetate into subcutaneous adipose tissue lipid was linear for the duration of the infusion period. Subsequent measures of rates of [1-14C]acetate incorporation into adipose tissue lipid were made on adipose tissue samples taken at a single time point during the infusion period. The technique was used to measure rates of lipogenesis in the subcutaneous adipose tissue of fourteen Hereford × Friesian steers that had been fed a pelleted diet of dried grass at a range of metabolizable energy (ME) intakes from 1·1 × ME requirement for maintenance toad libitumfor 11 weeks. Rates of lipogenesis increased linearly (P<0·001) with increasing ME intake. It was concluded that the method is an effective technique for measuring rates of lipogenesis in specific adipose tissue depotsin vivoin ruminants.
Inter-pregnancy folate and iron status of women in an inner-city population
Authors: Doyle Wendy , Srivastava Apama , Crawford Michael A. , Bhatti Rupinda , Brooke Zoeé , Costeloe Kate L.
Published: May 2008

The purpose of the present study was to evaluate whether micronutrient supplementation improved the nutritional status of women with poor diets during the inter-pregnancy interval. Fifty-five women who had given birth to a low birth weight baby (<2·5 kg), and who planned to have a further pregnancy, were recruited to a prospective randomised study in East London, UK. Of the fifty-five mothers recruited, forty-four (78 %) met fewer than four of sixteen dietary reference values according to the information provided in a 7 d diet diary, and were categorised as having an ‘inadequate’ diet. Half of the mothers in the ‘inadequate’-diet group were randomly assigned to receive a micronutrient and a single cell oil supplement containing docosahexaenoic acid. All participants received dietary advice based on analysis of their diet diaries, and general lifestyle advice on preparing for pregnancy. Mothers had a blood sample taken at 3 and 9 months post-partum to measure their folate, Fe stores and fatty acid status. Mean serum and erythrocyte folate levels increased significantly between 3 and 9 months post-partum in both the adequate-diet group and the supplemented group. At 9 months post-partum, over half of the unsupplemented, inadequate-diet group remained severely deficient in folate (serum folate <230 nmol/l) and had low serum ferritin levels (<15 μg/l). The high prevalence of inadequate diets in this inner-city population and the low motivation of women to participate in a nutrition programme suggests that consideration should be given to the provision of free folate and Fe supplements to all women in this and similar populations, or at least to women who have delivered a low birth weight baby, who plan further pregnancies.
Daily dietary intake of chromium in southern Spain measured with duplicate diet sampling
Authors: Garcia Elena , Carbrera Carmen , Lorenzo M. Luisa , Sánchez Joaquin , López M. Carmen
Published: May 2008

We measured daily dietary Cr intake in southern Spain by sampling duplicate diets for seven consecutive days in different population groups. Cr was determined by electrothermal atomization–atomic absorption spectrometry. The samples were mineralized in a digestion block with HNO3, HClO4and V2O5. A total of 161 duplicate diets from twenty-three subjects were analysed, and mean levels of Cr intake ranged from 9·39 to 205·16 μg/d. Mean Cr intake (100 μg/d) was similar to levels found for most other countries, and was within the range recommended by the National Research Council for a safe and adequate daily intake (50–200 μg/d). Chromium intake correlated significantly with energy, protein and carbohydrate intake, and with the daily intake of Zn, Fe, Mg, K, Na, Ca and nicotinic acid in the diets analysed.
Effects of whole wheat dilution v. substitution on coccidiosis in broiler chickens
Authors: Banfield M.J. , Forbes J.M
Published: May 2008

To test the hypothesis that inclusion of whole cereals in the diet of broiler chickens reduces the severity of a coccidial infection, the effects were investigated, in birds infected with Eimeria acervulina, of feeding a complete pelleted control food, the control food diluted with whole wheat (400 g/kg), or a diet in which ground wheat in the pellets was substituted with whole wheat (400 g/kg) so as to achieve the same composition as the control diet. In the weeks prior to and after infection, (days 14–20 and days 21–27), no significant differences in performance were observed between birds fed the complete pellet and substituted feeds. Birds fed the diluted feeds had significantly lower gains per unit of feed and numerically lower weight gains than the birds fed the control and substituted feeds during this period. No significant differences in performance were observed between treatments from days 28–34. Diluting feeds with whole wheat (400 g/kg) significantly increased ileal digesta viscosity levels, compared with feeding the control and substituted feeds in birds dissected on day 21, although no significant differences in digesta viscosity levels were observed in birds dissected on day 35. Whole wheat feeding, either by dilution or substitution, significantly increased gizzard sizes in birds dissected on day 21 and day 35. Neither dilution nor substitution of feeds with whole wheat (400 g/kg) significantly affected the level of an Eimeria acervulina infection, as measured by daily and total faecal oocyst yields.
Nutrition and cognitive impairment in the elderly
Authors: González-Gross M. , Marcos Ascensión , Pietrzik Klaus
Published: May 2008

As the number of older people is growing rapidly worldwide and the fact that elderly people are also apparently living longer, dementia, the most common cause of cognitive impairment is getting to be a greater public health problem. Nutrition plays a role in the ageing process, but there is still a lack of knowledge about nutrition-related risk factors in cognitive impairment. Research in this area has been intensive during the last decade, and results indicate that subclinical deficiency in essential nutrients (antioxidants such as vitamins C, E and β-carotene, vitamin B12, vitamin B6, folate) and nutrition-related disorders, as hypercholesterolaemia, hypertriacylglycerolaemia, hypertension, and diabetes could be some of the nutrition-related risk factors, which can be present for a long time before cognitive impairment becomes evident. Large-scale clinical trials in high-risk populations are needed to determine whether lowering blood homocysteine levels reduces the risk of cognitive impairment and may delay the clinical onset of dementia and perhaps of Alzheimer's disease. A curative treatment of cognitive impairment, especially Alzheimer's disease, is currently impossible. Actual drug therapy, if started early enough, may slow down the progression of the disease. Longitudinal studies are required in order to establish the possible link of nutrient intake – nutritional status with cognitive impairment, and if it is possible, in fact, to inhibit or delay the onset of dementia.
Phytate levels in diverse rat tissues: influence of dietary phytate
Authors: Grases F. , Simonet B. M. , Prieto R. M. , March J.G
Published: May 2008

Phytate (inositol hexaphosphate; InsP6) was determined in rat tissues fed on diets with different phytate contents, using a GC–mass detection methodology that permitted the evaluation of the total amount of this substance present in such tissues. The highest InsP6concentrations were found in brain (5·89×10-2 (SE 5·7×10-3) MG/G DM), WHEREAS THE CONCENTRATIONS DETECTED IN KIDNEYS, LIVER AND BONE WERE SIMILAR TO EACH OTHER (1·96×10-3 (se 0·20×10-3), 3·11×10-3 (se 0·24×10-3), 1·77×10-3 (se 0·17×10-3) mg/g DM respectively) and 10-fold less than those detected in brain. When rats were fed on a purified diet in which InsP6was undetectable, the InsP6levels of the organs mentioned earlier decreased dramatically (9·0×10-4, 3·8×10-5, 1·4×10-5 mg/g DM in brain, kidneys and liver respectively) and in some cases became undetectable (bone). The addition of InsP6to this purified diet led to the increase of InsP6levels in these tissues. This clearly demonstrated that the majority of the InsP6found in organs and tissues has a dietary origin and is not a consequence of endogenous synthesis. Consequently, considering that InsP6could be involved in some important biological roles, the value of any diet on supplying this substance is noteworthy.
The erythrocyte incorporation of absorbed non-haem iron in pregnant women
Authors: Whittaker Paul G. , Barrett Jon F.R. , Lind Tom
Published: May 2008

Studies of Fe absorption in pregnancy often make unfounded assumptions of erythrocyte incorporation. Therefore, we measured the absorption and utilisation of Fe during early and late pregnancy by the erythrocyte incorporation of two stable isotopes. 8·5 mg57Fe (oral) and 0·5 mg58Fe (intravenous) were given to five non-pregnant women, to five women in early gestation (12 weeks) and five women in late gestation (36 weeks). The stable isotope ratios in whole blood 14 d later were measured by MS. Together with estimation of body Fe mass, this enabled the calculation of Fe absorption and erythrocyte incorporation. In non-pregnant women, Fe absorption averaged 20·3 (range 10·2–34·3) %. It was not significantly different in early pregnancy (11·8 (range, 4·4–24·8) %), but during late pregnancy Fe absorption increased to 59·0 (range 38·2–77·2) %. All non-pregnant and early-pregnancy subjects had normal Fe status, but two women in late pregnancy had evidence of Fe insufficiency. During early and late pregnancy, mean erythrocyte incorporation was 63·4 (SD 12·1) % AND 71·0 (sd 10·4) % respectively, significantly reduced (P=0·003) compared with non-pregnant subjects (90·1 (sd 6·0) %). Decreased erythrocyte incorporation of absorbed Fe in early pregnancy is compatible with reduced Fe demand and low oral absorption. However, during late pregnancy decreased erythrocyte incorporation associated with high absorption and Fe insufficiency is different from the high erythrocyte incorporation which occurs in non-pregnant Fe-deficient women. This suggests that part of the aetiology of Fe deficiency during pregnancy may be the reduction of Fe utilisation.
Learning behaviour and cerebral protein kinase C, antioxidant status, lipid composition in senescence-accelerated mouse: influence of a phosphatidylcholine–vitamin B12diet
Authors: Hung Mei-Chu , Shibasaki Koji , Yoshida Riki , Sato Masao , Imaizumi Katsumi
Published: May 2008

Our objective was to determine whether dietary supplementation with phosphatidylcholine (PC) plus vitamin B12could afford beneficial effects on biochemical and biophysical events in the brain of senescence-accelerated mouse (SAM) substrain SAMP8. We measured learning behaviour, hippocampal protein kinase C (PKC) activity, cerebral antioxidant status, phospholipid composition and fatty acid composition in 6-month-old SAMP8 and in age-matched controls (SAM substrain SAMR1). In comparison with SAMR1, SAMP8 showed a significant elevation in total grading score of senescence (P<0·05) and a significant decline in acquisition (P<0·05). SAMP8 had a lower hippocampal PKC activity and cerebral PKC-β mRNA abundance than SAMR1. SAMP8 had increased cerebral lipid peroxide levels and proportion of sphingomyelin, and a lower proportion of 20 : 4n-6 and 22 : 6n-3 in cerebral phosphtidylethanolamine than SAMR1. SAMP8 fed the PC combined with vitamin B12diet had an increased PKC activity and a higher proportion of 22 : 6n-3 than SAMP8 fed the control diet. These results indicate the potential benefit of PC combined with vitamin B12as a dietary supplement.
The prebiotic effects of biscuits containing partially hydrolysed guar gum and fructo-oligosaccharides – a human volunteer study
Authors: Tuohy K. M. , Kolida S. , Lustenberger A. M. , Gibson G. R.
Published: May 2008

Prebiotics are non-digestible food ingredients that target selected groups of the human colonic microflora, thus having the ability to alter the composition towards a more ‘beneficial’ community, i.e. selectively increasing populations of bifidobacteria and/or lactobacilli. In the present study the prebiotic potential of partially hydrolysed guar gum (PHGG) and fructo-oligosaccharides (FOS) in a biscuit was assessed in human volunteers. Fluorescentin situhybridization using oligonucleotide probes targetingBacteroidesspp.,Bifidobacteriumspp.,Clostridiumspp. andLactobacillus–Enterococcusspp. were used for the bacteriology and total bacteria were enumerated using the fluorescent stain 4′,6-diamidino-2-phenylindole. Thirty-one volunteers consumed daily either three experimental biscuits (providing a total (g/d) of 6·6 FOS and 3·4 PHGG) or three placebo biscuits for two 21-d crossover periods. Bifidobacteria significantly increased in number on ingestion of the experimental biscuits compared with pre-treatment and placebo population levels. Bifidobacterial numbers returned to pretreatment levels within 7 d of the cessation of intake of experimental biscuits. A correlation was observed between the initial faecal bifidobacterial numbers and the magnitude of bifidogenesis, with volunteers who possessed low initial population levels of bifidobacteria experiencing the greatest increase in bifidogenesis. No changes were observed in the other bacterial groups monitored during the trial. Thus, the prebiotic nature of FOS and PHGG was maintained in a final food product as evidenced from the selective increase in bifidobacterial numbers.
Obesity and undernutrition in a very-low-income population in the city of Maceió, northeastern Brazil
Authors: Florêncio Telma Maria de Menezes Toledo , Ferreira Haroldo da Silva , França Anna Patrícia Tojal de , Cavalcante Jairo Calado , Sawaya Ana Lydia
Published: May 2008

Obesity is the nutritional disorder which has shown the greatest increase in prevalence, even in those countries in which deficiency diseases represent a severe public health problem. The goal of the present study was to analyse the anthropometric profile of a community living in the outskirts of Maceió, capital of Alagoas (northeastern Brazil), and to investigate the hypothesis of a coexistence of undernutrition and obesity in a very low-income population. The survey was conducted on 315 families (1247 individuals). Among the children (aged ≤10 years), the prevalence of wasting, stunting and wasting plus stunting was 3·8, 8·3 and 8·7 % respectively. Wasting (10·2 %) was the most prevalent form of undernutrition among adolescents; nonetheless, a higher frequency of stunting (11 %) and overweight–obesity (5·5 %) was seen specifically in girls, in agreement with trends found in other studies. Adults exhibited a high prevalence of overweight–obesity (25 %), but stunting was also present (22 %). Of the stunted individuals, 30 % were overweight–obese and 16·3 % were underweight. There were eighty-six families with at least one parent who was underweight (27 %) and 104 families with at least one parent who was overweight (33 %). Underweight and overweight–obesity were both present in ninety-six households (30 %). These results may indicate that better living conditions in urban areas in a population ‘adapted’ to chronic famine might increase the susceptibility to obesity. Considering the harm caused by the cumulative effect of these two conditions (undernutrition in childhood and obesity in adult life) there is a clear need for new studies to uncover the determinant factors so that preventive measures can be implemented.
Placebo expectancy effects in the relationship between glucose and cognition
Authors: Green Michael W. , Taylor Moira A. , Elliman Nicola A. , Rhodes Oril
Published: May 2008

The present study investigated the extent of expectancy in the ability of glucose to affect cognitive performance. Using a within-subjects design, subjects (n26) completed four experimental sessions (in counterbalanced order and after an initial practice session) during which they were given a 500 ml drink 30 min prior to completing a cognitive assessment battery. In addition, all subjects completed a baseline practice session during which they were given no drink. During two of the sessions, subjects were given a drink containing 50 g glucose and on the other two they were given a drink containing aspartame. A balanced placebo design was used, such that for half the sessions subjects were accurately informed as to the content of the drink (glucose or aspartame), whereas in the other two sessions they were misinformed as to the content of the drink. The task battery comprised a 6 min visual analogue of the Bakan vigilance task, an immediate verbal free-recall task, an immediate verbal recognition memory task and a measure of motor speed (two-finger tapping). Blood glucose and self-reported mood were also recorded at several time points during each session. Glucose administration was found to improve recognition memory times, in direct contrast to previous findings in the literature. Glucose administration also improved performance on the Bakan task (relative to the control drink), but only in sessions where subjects were informed that they would receive glucose and not when they were told that they would receive aspartame. There were no effects either of the nature of the drink or expectancy on the other measures. These results are interpreted in terms of there being some contribution of expectancy concerning the positive effects of glucose on cognition in studies which have not used an equi-sweet dose of aspartame as a control drink.
Viability and dose–response studies on the effects of the immunoenhancing lactic acid bacteriumLactobacillus rhamnosusin mice
Authors: Gill H.S. , Rutherfurd K.J.
Published: May 2008

Previous studies have indicated that the lactic acid bacteriumLactobacillus rhamnosusHN001 can enhance immune function in mice, following oral delivery. However, the influence of bacterial cell viability on immunoenhancement, and the optimum dose of HN001 required for this effect, have not been determined. In the present study, both live and heat-killed preparations ofL. rhamnosusHN001 were shown to enhance the phagocytic activity of blood and peritoneal leucocytes in mice, at a dose of 109micro-organisms daily. In contrast, only live HN001 enhanced gut mucosal antibody responses to cholera toxin vaccine. Feeding mice with 107viable HN001/d for 14 d was shown to enhance the phagocytic capacity of blood leucocytes, with incremental enhancement observed at 109and 1011daily doses. In contrast, a minimum dose of 109viable HN001/d was required to enhance the phagocytic activity of peritoneal leucocytes, and no further increment was observed with 1011daily. This study demonstrates thatL. rhamnosusHN001 exhibits dose-dependent effects on the phagocytic defence system of mice, and suggests that while the innate cellular immune system is responsive to killed forms of food-borne bacteria, specific gut mucosal immunity may only be stimulated by live forms.
Oligofructose and long-chain inulin: influence on the gut microbial ecology of rats associated with a human faecal flora
Authors: Kleessen Brigitta , Hartmann Ludger , Blaut Michael
Published: May 2008

Dietary incorporation of fermentable, indigestible fructans may be of benefit to gastrointestinal health by providing short-chain fatty acids, stimulating the proliferation of bifidobacteria or lactobacilli and suppressing potential pathogenic organisms in the gut. We tested the hypothesis that the effects of fructans on caecal, colonic and faecal short-chain fatty acid concentration and microflora composition depend on their chain length. Germ-free rats associated with a human faecal flora were randomly assigned to one of four treatments as follows: (1) commercial standard diet as a control (Con); (2) Con+50 g short-chain oligofructose/kg (OF); (3) C+50 g long-chain inulin/kg (lcIN); or (4) Con+50 g OF–lcIN/kg (Mix OF–lcIN). Changes in bacterial population groups in response to feeding these diets were investigated with 16S rRNA-targeted probes applied inin situhybridization. Mix OF–lcIN- and lcIN-containing diets resulted in larger numbers of caecal, colonic and faecal bacteria of theClostridium coccoides–Eubacterium rectalecluster than Con (10·6 and 10·3v.9·5 log10/g wet wt), whereas OF alone did not affect this bacterial group in caecum, colon or faeces. A bifidogenic effect was only observed in the colon and faeces of OF-treated rats. More lactobacilli were found in caecal and colonic contents of Mix OF–lcIN-fed rats and in faeces of OF-fed rats compared with Con. Mix OF–lcIN and OF led to significantly smaller numbers of caecal, colonic and faecal bacteria belonging to theClostridium histolyticumandC. lituseburensegroups than Con (6·8 and 6·9v.7·9 log10/g wet wt). Counts of total bacteria,Bacteroides–PrevotellaandEnterobacteriaceaedid not differ between the groups. OF and/or lcIN-containing diets significantly increased the caecal and colonic concentration of butyrate and its relative molar proportion. Only lcIN-containing diets resulted in a higher faecal concentration of butyrate than Con. Higher molar proportions of faecal butyrate were observed with all diets that had been supplemented with OF and/or lcIN. Stimulation of butyrate production could be of interest for the prevention of ulcerative colitis and colon cancer.
Uncoupling proteins: their roles in adaptive thermogenesis and substrate metabolism reconsidered
Authors: Dulloo Abdul G. , Samec Sonia
Published: May 2008

During the past few years, there have been two major developments, if not revolutions, in the field of energy balance and weight regulation. The first at the molecular level, which was catalysed by developments in DNA screening technology together with the mapping of the human genome, has been the tremendous advances made in the identification of molecules that play a role in the control of food intake and metabolic rate. The second, at the systemic level, which centered upon the use of modern technologies or more robust analytical techniques for assessing human energy expenditure in response to starvation and overfeeding, has been the publication of several papers providing strong evidence that adaptive thermogenesis plays a much more important role in the regulation of body weight and body composition than previously thought. Within these same few years, several new members of the mitochondrial carrier protein family have been identified in a variety of tissues and organs. All apparently possess uncoupling properties in genetically-modified systems, with two of them (uncoupling protein (UCP) 2 and UCP3) being expressed in adipose tissues and skeletal muscles, which are generally recognised as important sites for variations in thermogenesis and/or in substrate oxidation. Considered as breakthrough discoveries, the cloning of these genes has generated considerable optimism for rapid advances in our molecular understanding of adaptive thermogenesis, and for the identification of new targets for pharmacological management of obesity and cachexia. The present paper traces first, from a historical perspective, the landmark events in the field of thermogenesis that led to the identification of these genes encoding candidate UCP, and then addresses the controversies and on-going debate about their physiological importance in adaptive thermogenesis, in lipid oxidation or in oxidative stress. The general conclusion is that UCP2 and UCP3 may have distinct primary functions, with UCP3 implicated in regulating the flux of lipid substrates across the mitochondria and UCP2 in the control of mitochondrial generation of reactive oxygen species. The distinct functions of these two UCP1 homologues have been incorporated in a conceptual model to illustrate how UCP2 and UCP3 may act in concert in the overall regulation of lipid oxidation concomitant to the prevention of lipid-induced oxidative damage.
Markers of high fish intake are associated with decreased risk of a first myocardial infarction
Authors: Hallgren C. G. , Hallmans G. , Jansson J.-H. , Marklund S. L. , Huhtasaari F. , Schütz A. , Strömberg U. , Vessby B. , Skerfving S.
Published: May 2008

High intake of fish has been associated with reduced risk of CHD. The high content of n-3 polyunsaturated fatty acids (PUFA) in fish has been suggested to be a protective factor. In addition, fish is the entirely dominating source of methylmercury for the general population, and the concentration of Hg in erythrocytes (Ery-Hg) is often used as an index of fish consumption. Our aim was to study the relationships between a first-ever myocardial infarction, Ery-Hg, activity of gluthathione peroxidase in erythrocytes (Ery-GSH-Px) and plasma concentration of the n-3 PUFA eicosapentaenoic and docosahexaenoic acids (P-PUFA). In a population-based prospective nested case–control study within Northern Sweden seventy-eight cases of a first-ever myocardial infarction were compared with 156 controls with respect to Ery-Hg, P-PUFA and Ery-GSH-Px. Both Ery-Hg and P-PUFA, but not Ery-GSH-Px, were significantly (P<0·0001) higher in subjects reporting high fish intake (at least one meal per week) than in those with lower intake. This finding suggests that Ery-Hg and P-PUFA reflect previous long-term fish intake. Low risk of myocardial infarction was associated with high Ery-Hg or high P-PUFA. In a multivariate model the risk of myocardial infarction was further reduced in subjects with both high Ery-Hg and high P-PUFA (odds ratio 0·16, 95 % CI 0·04, 0·65). In conclusion, there is a strong inverse association between the risk of a first myocardial infarction and the biomarkers of fish intake, Ery-Hg and P-PUFA, and this association is independent of traditional risk factors.
Ingestion of insoluble dietary fibre increased zinc and iron absorption and restored growth rate and zinc absorption suppressed by dietary phytate in rats
Authors: Hayashi Kumiko , Hara Hiroshi , Asvarujanon Patchana , Aoyama Yoritaka , Luangpituksa Pairojana
Published: May 2008

We examined the effects of ingestion of five types of insoluble fibre on growth and Zn absorption in rats fed a marginally Zn-deficient diet (6·75 mg (0·103 mmol) Zn/kg diet) with or without added sodium phytate (12·6 mmol/kg diet). The types of insoluble fibre tested were corn husks, watermelon skin, yam-bean root (Pachyrhizus erosus) and pineapple core, and cellulose was used as a control (100 g/kg diet). Body-weight gain in the cellulose groups was suppressed by 57 % by feeding phytate. Body-weight gain in phytate-fed rats was 80 % greater in the watermelon skin fibre and yam-bean root fibre group than that in the cellulose group. Zn absorption ratio in the cellulose groups was lowered by 46 and 70 % in the first (days 7–10) and second (days 16–19) measurement periods with feeding phytate. In the rats fed the phytate-containing diets, Zn absorption ratio in the watermelon skin, yam-bean root and pineapple core fibre groups was 140, 80 and 54 % higher respectively than that in the cellulose group, in the second period. Fe absorption was not suppressed by phytate, however, feeding of these three types of fibre promoted Fe absorption in rats fed phytate-free diets. The concentration of soluble Zn in the caecal contents in the watermelon skin fibre or yam-bean root fibre groups was identical to that in the control group in spite of a higher short-chain fatty acid concentration and lower pH in the caecum. These findings indicate that ingestion of these types of insoluble fibre recovered the growth and Zn absorption suppressed by feeding a high level of phytate, and factors other than caecal fermentation may also be involved in this effect of insoluble fibre.
Riboflavin deficiency: early effects on post-weaning development of the duodenum in rats
Authors: Yates Catherine A , Evans Gareth S. , Powers Hilary J.
Published: May 2008

The aim of this present study was to identify the earliest point at which riboflavin deficiency affects post-weaning bowel development in rats. After weaning, eighty Wistar rats were weight-matched as pairs, one animal being fed a normal synthetic diet and the other being fed the same diet but deficient in riboflavin. Body weight, feeding and rates of growth were monitored and eight pairs of animals were taken for analysis at 45, 69, 93, 117 and 141 h. Riboflavin status was monitored by determining the erythrocyte glutathione reductase activation coefficient (EGRAC), and hepatic flavins were measured by a fluorescence assay. Changes to the number and dimensions of villi and crypts in the duodenum were determined, as well as crypt division (bifurcation) and the DNA synthesis index of the crypt epithelium by bromodeoxyuridine (BrdU) labelling. Riboflavin deficiency was established in the experimental rats, as demonstrated by a significant increase in EGRAC after 45 h (P<0·001) and decreased liver flavins after 96 h (P<0·001). After 96 h a significant increase in the size and cellularity of the crypts (P<0·001 in both cases) was seen in these riboflavin-deficient animals, with a decreased incidence of bifurcating crypts and of BrdU-labelled cells. No changes to villus number or size were observed. The present study has demonstrated that developmental changes to the duodenal crypt arise shortly after circulating riboflavin measurements show evidence of deficiency. These changes primarily affect cell proliferation and crypt bifurcation, and precede long-term changes such as the reduction of villus number.
Low iron status and enhanced insulin sensitivity in lacto-ovo vegetarians
Authors: Hua Nancy W. , Stoohs Riccardo A. , Facchini Francesco S.
Published: May 2008

The efficacy of insulin in stimulating whole-body glucose disposal (insulin sensitivity) was quantified using direct methodology in thirty lacto-ovo vegetarians and in thirty meat-eaters. All subjects were adult, lean (BMI <23 kg/m2), healthy and glucose tolerant. Lacto-ovo vegetarians were more insulin sensitive than meat-eaters, with a steady-state plasma glucose (mmol/l) of 4·1 (95 % CI 3·5, 5·0)v.6·9 (95 % CI 5·2, 7·5; P=0·0028) respectively. In addition, lacto-ovo vegetarians had lower body Fe stores, as indicated by a serum ferritin concentration (μg/l) of 35 (95 % CI 21, 49) compared with 72 (95 % CI 45, 100) for meat-eaters (P=0·0012). To test whether or not Fe status might modulate insulin sensitivity, body Fe was lowered by phlebotomy in six male meat-eaters to levels similar to that seen in vegetarians, with a resultant approximately 40 % enhancement of insulin-mediated glucose disposal (P=0·0008). Our results demonstrate that lacto-ovo vegetarians are more insulin sensitive and have lower Fe stores than meat-eaters. In addition, it seems that reduced insulin sensitivity in meat-eaters is amenable to improvement by reducing body Fe. The latter finding is in agreement with results from animal studies where, no matter how induced, Fe depletion consistently enhanced glucose disposal.
Changes in piglet tissue composition at birth in response to increasing maternal intake of long-chainn-3 polyunsaturated fatty acids are non-linear
Authors: Rooke J.A , SinclaiR A. G. , Ewen M.
Published: May 2008

Addition of marine oils containing long-chainn-3 polyunsaturated fatty acids to the diet of pregnant sows may reduce piglet mortality. In previous experiments, when marine oils have been fed to pregnant sows, improvements in piglet tissue 22 : 6n-3 status have been accompanied by potentially undesirable decreases in 20 : 4n-6. The objective of the present experiment was to establish an amount of dietary salmon oil which would enhance piglet 22 : 6n-3 status while minimising reductions in 20 : 4n-6. Twenty-four pregnant multiparous sows were used in the experiment which began on day 60 of pregnancy (gestation length 115 d). To give four diets, salmon oil was added in increasing amounts (0, 5, 10 and 20 g/kg diet) to a basal diet; the diets were made isoenergetic by adding palm oil to each diet to give a total of 20 g oil/kg diet. Diets were offered to the sows in fixed amounts (2·5 kg/d) until parturition. Piglet tissue samples (brain, liver and retina) were obtained at birth before consumption of colostrum. The greatest increase in piglet tissue 22 : 6n-3 proportions occurred between 0 and 5 g salmon oil/kg diet, with only small increases between 10 and 20 g salmon oil/kg diet. In contrast, tissue 20 : 4n-6 proportions declined progressively as the amount of salmon oil fed to the sow increased. In brain, the change in the value 22 : 6n-3/22 : 5n-6 was greatest between 0 and 5 g salmon oil/kg diet, whereas in liver the value increased linearly with added salmon oil. In addition, piglet brain weight (g/kg live weight) increased to a maximum at 10 g salmon oil/kg diet. The optimum amount of supplementary salmon oil in the current experiment, defined as that which gave the greatest response in brain 22 : 6n-3 proportions with minimum reduction in 20 : 4n-6,was 10 g salmon oil/kg diet. This corresponds to an intake of approximately 2·4 g 20 : 5n-3 plus 3·6 g 22 : 6n-3/d or 0·6 % digestible energy.
Soya intake and plasma concentrations of daidzein and genistein: validity of dietary assessment among eighty British women (Oxford arm of the European Prospective Investigation into Cancer and Nutrition)
Authors: Verkasalo Pai K. , Appleby Paul N. , Allen Naomi E. , Davey Gwyneth , Adlercreutz Herman , Key Timothy J.
Published: May 2008

Soya products contain high levels of the isoflavones genistein and daidzein, and their glucosides, and may lower the risk of cardiovascular disease, osteoporosis and cancer. The present cross-sectional study investigated plasma concentrations of daidzein and genistein and their correlations with dietary soya consumption in four groups of twenty premenopausal British women. The women were selected from the Oxford arm of the European Prospective Investigation into Cancer and Nutrition using data from food-frequency questionnaires (FFQ) to guarantee a wide variation in soya consumption, and to investigate the utility of the question related to soya milk consumption compared with the utility of the question related to other soya foods. Dietary intakes of isoflavones were additionally assessed by 7 d food diaries. Plasma concentrations of daidzein and genistein were measured by time-resolved fluoroimmunoassay. Geometric mean plasma concentrations (nmol/l) were for the four groups, which were based on increasing soya intake, 4·9, 8·4, 39·2 and 132 for daidzein and 14·3, 16·5, 119 and 378 for genistein. The Spearman correlation coefficients for plasma isoflavone concentrations with estimated dietary intakes were between 0·66 and 0·80 for the diary-based estimates and between 0·24 and 0·74 for the FFQ-based estimates. The correlations for soya milk intakes were clearly higher than the correlations for intakes of other soya foods. We conclude that both the food diary and the FFQ estimate dietary soya isoflavone intakes sufficiently well to use them in epidemiological studies, and that plasma concentrations of daidzein and genistein in Western women who consumed soya products as a part of their regular diet were close to those in Asian populations.
Dietary intake of folate by adolescents and the potential effect of flour fortification with folic acid
Authors: Moynihan P. J. , Rugg-Gunn A. J. , Butler T. J. , Adamson A. J.
Published: May 2008

The UK Department of Health recently recommended that flour be fortified with folic acid, at 2400 μg/kg. The objectives of the present paper were: to determine the consequence of this on folic acid intake of adolescents; to determine the level of fortification necessary to achieve an intake of 400 μg/d in adolescent girls (the amount recommended periconceptionally); to estimate the consequence of fortification on folic acid intake of high flour consumers; and to report on folate intake of adolescents. Dietary intake of folate and flour were determined by analysis of an existing database of the diets of 379 English adolescents. The folic acid intake that would result from white flour fortification with folic acid at 2400 μg/kg was determined and the level of folic acid fortification necessary to achieve an intake of 400 μg/d in girls from this source was also calculated. Without flour fortification, 6·9 % of girls failed to reach the UK lower reference nutrient intake for total folate. Fortification of white flour with folic acid at 2400 μg/kg would result in an additional folic acid intake of 191(SEM 6) μg/d in girls. To ensure 97 % of girls received 400 μg/d from white flour, white flour would need to be fortified at a level of 10 430 μg/kg, resulting in intakes of 1260 μg/d from flour in the highest (97·5 centile) female white flour consumers and 1422 μg/d from flour in the highest (97·5 centile) male white flour consumers.
Short- and long-term effects of calcium and exercise on bone mineral density in ovariectomized rats
Authors: Gala Joseé , Di´az-curiel Manuel , Piedra Concepcioó de la , Calero Jesu´s
Published: May 2008

At the level of prevention of bone mineral loss produced by ovariectomy, the aim of the present study was to determine the effect produced by supplementation of Ca in the diet and a moderate exercise programme (treadmill), simultaneously or separately, in ovariectomized rats, an experimental model of postmenopausal bone loss. Female Wistar rats (n110, 15 weeks old) were divided into five groups: (1) OVX, rats ovariectomized at 15 weeks of age, fed a standard diet; (2) SHAM, rats sham operated at 15 weeks of age, fed a standard diet; (3) OVX–EX, ovariectomized rats, fed a standard diet and performing the established exercise programme; (4) OVX–Ca, ovariectomized rats fed a diet supplemented with Ca; (5) OVX–EXCa, ovariectomized rats with the exercise programme and diet supplemented with Ca. The different treatments were initiated 1 week after ovariectomy and were continued for 13 weeks for subgroup 1 and 28 weeks for subgroup 2, to look at the interaction of age and time passed from ovariectomy on the treatments. Bone mineral density (BMD) was determined, at the end of the study, in the lumbar spine (L2, L3 and L4) and in the left femur using a densitometer. Bone turnover was also estimated at the end of the study, measuring the serum formation marker total alkaline phosphatase (AP) and the resorption marker serum tartrate-resistant acid phosphatase (TRAP). As expected, OVX rats showed a significant decrease (P<0·05) in BMD, more pronounced in subgroup 2, and a significant increase in AP and TRAP with regard to their respective SHAM group. The simultaneous treatment with Ca and exercise produced the best effects on lumbar and femoral BMD of ovariectomized rats, partially avoiding bone loss produced by ovariectomy, although it was not able to fully maintain BMD levels of intact animals. This combined treatment produced a significant increase in AP, both in subgroups 1 and 2, and a decrease in TRAP in subgroup 1, with regard to OVX group. The exercise treatment alone was able to produce an increase in BMD with regard to OVX group only in subgroup 1 of rats (younger animals and less time from ovariectomy), but not in subgroup 2. In agreement with this, there was an increase of AP in both subgroups, lower than that observed in animals submitted to exercise plus Ca supplement, and a decrease of TRAP in subgroup 1, without significant changes in this marker in the older rats. Ca treatment did not produce any significant effect on BMD in OVX rats in both subgroups of animals, showing a decrease of AP and TRAP levels in the younger animals with no significant variations in markers of bone remodelling in the older female rats compared with their respective OVX group.
Effects of two fermentable carbohydrates (inulin and resistant starch) and their combination on calcium and magnesium balance in rats
Authors: Younes Hassan , Coudray Charles , Bellanger Jacques , Demigné Christian , Rayssiguier Yves , Rémésy Christian
Published: May 2008

Resistant starch and inulin are complex carbohydrates that are fermented by the microflora and known to increase colonic absorption of minerals in animals. The fermentation of these substrates in the large bowel to short-chain fatty acids is the main reason for this increase in mineral absorption. The purpose of the present study was to examine the potential synergistic effect of a combination of these two fermentable carbohydrates. For this purpose, thirty-two adult male Wistar rats weighing 200 g were used in the present study. The rats were distributed into four groups, and fed for 21 d a fibre-free basal purified diet or diet containing 100 g inulin, or 150 g resistant starch (raw potato starch)/kg diet or a blend of 50 g inulin and 75 g resistant starch/kg diet. After an adaptation period of 14 d, the rats were then transferred to metabolic cages and dietary intake, faeces and urine were monitored for 5 d. The animals were then anaesthetized and caecal Ca and Mg absorption were measured. Finally, the rats were killed and blood, caecum and tissues were sampled. Ca and Mg levels were assessed in diets, faeces, urine, caecum and plasma by atomic absorption spectrometry. Our results confirmed that inulin and resistant starch ingestion led to considerable caecal fermentation in the three experimental groups compared with the control group diet. Moreover, both carbohydrates significantly increased the intestinal absorption and balance of Ca and Mg, without altering the plasma level of these two minerals. Interestingly, the combination of the studied carbohydrates increased significantly (P<0·05) the caecal soluble Ca and Mg concentrations, the apparent intestinal absorption and balance of Ca, and non-significantly the plasma Mg level. In conclusion, a combination of different carbohydrates showed synergistic effects on intestinal Ca absorption and balance in rats. Further studies with other types of carbohydrate combinations should be carried out to extend these findings.
Differences in tissue fatty acid composition between reared and wild sharpsnout sea bream,Diplodus puntazzo(Cetti, 1777)
Authors: Rueda F. M. , Hernández M. D. , Egea M. A. , Aguado F. , García B. , Martínez F. J.
Published: May 2008

The fatty acid composition and lipid content of white muscle, liver and mesenteric fat, in rearedv.wild sharpsnout sea bream (Diplodus puntazzo) were compared. The mesenteric fat index (100×mesenteric fat weight/body weight) and the lipid contents of both white muscle and liver proved consistently higher in farmedv.wild sharpsnout sea bream (79·0 (SE 13·1)V.38·7 (se 5·1) g/kg, 188·4 (se 30·0)v.58·2 (se 3·9) g/kg and 27·2 (se 3·7)v.17·3 (se 1·9) g/kg, respectively). The higher values of linoleic, eicosapentaenoic, docosahexaenoic andn-3 series acids in reared fish muscle make reared sharpsnout more favourable for human consumption. In reared fish mesenteric fat, polyunsaturated fatty acids reached higher levels (32·54 (se 0·71) g/100 g total fatty acids than those found in wild fish (26·08 (se 1·38) g/100 g total fatty acids or even present in the diet (28·34 g/100 g total fatty acids). Compared with cultured fish, wild sharpsnout displayed a higher content ofn-3 fatty acids in liver fat (31·67 (se 1·13) g/100 g total fatty acids), but lower in mesenteric fat (20·35 (se 1·41) g/100 g total fatty acids). Atherogenic index values were similar for wild and reared fish in all tissues, while the index of thrombogenicity of muscle and mesenteric fat (0·353 (se 0·012) and 0·402 (se 0·021) respectively) was significantly increased in wild fish probably due to the omnivorous habits of the species and/or to seasonal food variations. Depending on the time of the year or the season, reared fish could be more suitable for human consumption than wild fish.