bluuebunny/crossref_metadata_2025 huggingface dataset:
Microbial thiamin metabolism in the rumen simulating fermenter (RUSITEC): the effect of acidogenic conditions, a high sulfur level and added thiamin
Authors: De Oliveira L. Alves , Jean-Blain C. , Komisarczuk-Bony S. , Durix A. , Durier C.
Published: June 2005

The effects of acidogenic conditions, a high S level and the addition of thiamin on the rumen microbial metabolism of thiamin were investigatedin vitroin a semi-continuous fermenter (RUSITEC), using a factorial design. Acidogenic conditions were obtained by simultaneously increasing the starch: cellulose ratio and the amount of solid substrate fed, and by decreasing the buffering capacity of the liquid phase of the fermenter. S in the form of sulfate was supplied at two levels, one corresponding to a control amount of S (2 g/kg dietary DM), the second to an excess (5 g/ kg DM) which is sufficient to trigger cerebrocortical necrosis (CCN) when usedin vivo.Acidogenic conditions decreased the pH of the fermenters, CH4production and cellulose digestibility, increased the short-chain fatty acid production, but had no effect on thiamin production. The high S level enhanced the production of sulfide considerably, had no effect on the microbial metabolism of energy and N, and decreased thiamin production (326 ν. 266 nmol/d). The added thiamin was rapidly converted into phosphorylated compounds which largely decreased the apparent synthesis of this vitamin by the rumen microflora. The total thiamin flow was increased by added thiamin. In no case was thiaminase activity in the fermenter liquid phase significantly modified. The high level of S induced only a limited decrease of total thiamin flow. Consequently, it is unlikely that the investigated factors could be considered to be high risk factors for the thiamin-dependent CCN.
Effects of dietary L-carnitine on the performance and egg quality of laying hens from 65–73 weeks of age
Authors: Rabie Mahmoud H. , SziláGyi MiháLy , Gippert Tibor
Published: June 2005

The effects of L-carnitine supplementation (50–500 mg/kg diet) of a practical layer diet, based on maize, soyabean and wheat, on the performance of laying hens and some indices of egg quality were studied for 8 weeks, using 65-week-old hens kept in cages. Albumen quality (albumen height and Haugh (1937) unit score) was improved, while yolk index and yolk colour score were not affected by dietary L-carnitine. The percentage of egg-white increased and that of egg yolk decreased in response to dietary supplementation of L-carnitine. Dietary L-carnitine did not influence laying performance (egg production rate, mean egg weight, daily feed intake, daily egg mass and feed conversion) or external egg quality measured by egg weight, egg-shape index or by eggshell quality, either measured directly as shell breaking strength or indirectly as shell weight, shell thickness or shell weight per unit surface area. Based on the results of the present study, L-carnitine had a beneficial effect on albumen quality and could modify the components of the edible part of the egg, during the late laying period.
Soluble-fibre concentrate lowers plasminogen activator inhibitor-1 in baboons (Papio ursinus)
Authors: Venter C. S. , Nel C. J. , Vorster H. H. , Jerling J. C. , Oosthuizen W. , Veldman F. J. , Kellerman J. A. , Smuts C. M. , Vermaak W. J. H. , Van Der Nest D. G. , Ridder J. H.
Published: June 2005

The effects of a soluble NSP (fibre) concentrate (SFC) on plasma fibrinogen and plasminogen activator inhibitor-1 (PAI-1), serum and liver lipids and lipoproteins and glucose tolerance were compared with those of bezafibrate (BF), a lipid-lowering drug, in obese baboons (Papio ursinus) The basal diet was a high-fat (37% of total energy), low-NSP (12.4 g/d) Westernized diet, supplemented for 8 weeks with either 20 SFCg/baboon per d or 6.7 mg BF/kg body weight per baboon per d. SFC supplementation significantly lowered PAI-1, total serum cholesterol, HDL-cholesterol and circulating free fatty acid levels. BF significantly lowered total serum cholesterol, but unexpectedly raised serum triacylglycerol levels. Although not statistically significant, the mean liver tricacylglycerol concentration of baboons fed on BF was lower than that of baboons fed on SFC supplements. These results suggest that: (1) the mechanism of action of the two cholesterol-lowering treatments differ, with BF having a liver triacylglycerol-lowering effect and (2) the SFC had additional beneficial effect on fibrinolysis by lowering PAI-1 levels.
Oral administration of deuterium-labelled polyamines to sucking rat pups: luminal uptake, metabolic fate and effects on gastrointestinal maturation
Authors: Dorhout Bernard , Van Faassen Anet , Van Beusekom Christien M. , Kingma Anneke W. , De Hoog Elly , Nagel Gijs T. , Karrenbeld Arend , Boersma E. Rudy , Muskiet Frits A. J.
Published: June 2005

Non-physiological amounts of oral polyamines have been reported to induce precocious gut maturation in rat pups. The aim of the present study was to investigate organ distribution and metabolic fate of orally administered stable-isotopically labelled polyamines in rat pups. Pups received tetradeuterium-labelled putrescine (Pu-d4; 3 μmol), spermidine (Sd-d4; 5 μmol), spermine (Sp-d4; 3 μmol), or physiological saline twice daily on postnatal days 7–10 or 12–15. They were killed on days 10 and 15. We determined activities of ileal lactase (EC3.2.1.23), maltase (EC3.2.1.20), sucrase (EC3.2.1.48) and diamine oxidase (EC1.4.3.6) and established villus and crypt lengths. Polyamines and their labelling percentages in organs were determined by GC and mass fragmentography. Treatments did not affect growth rate, but caused lower weights of liver, kidneys and heart. Maltase activity increased, lactase decreased, whereas sucrase and diamine oxidase did not change. Villus and crypt lengths increased. Organ polyamine pools were labelled to different extents. Irrespective of the orally administered polyamine, all organs contained Pu-d4, Sd-d4 and Sp-d4. Administered Pu-d4 and Sd-d4 were recovered mainly as Sd-d4, whereas Sp-d4 was recovered as Sp-d4 and Sd-d4. Total polyamines in a caecum, colon and erythrocytes increased, but increases were only to a minor extent with regard to labelled polyamines. Our data confirm precocious gut maturation by exogenous polyamines. Putrescine appears to be the limiting factor. The exogenous polyamines were distributed among all investigated organs. They are not only used for the synthesis of higher polyamines, but also retroconverted to their precursors. Changes in erythrocyte polyamine contents suggest precocious stimulation of erythropoiesis.
Critical evaluation of the factorial and heart-rate recording methods for the determination of energy expenditure of free-living elderly people
Authors: Morio Beatrice , Ritz Patrick , Verdier Elisabeth , Montaurier Christophe , Beaufrere Bernard , Vermorel Michel
Published: June 2005

The aim of the present study was to validate against the doubly-labelled water (DLW) technique the factorial method and the heart rate (HR) recording method for determining daily energy expenditure (DEE) of elderly people in free-living conditions. The two methods were first calibrated and validated in twelve healthy subjects (six males and six females; 70·1 (sd 2·7) years) from opencircuit whole-body indirect calorimetry measurements during three consecutive days and during 1 d respectively. Mean energy costs of the various usual activities were determined for each subject using the factorial method, and individual relationships were set up between HR and energy expenditure for the HR recording method. In free-living conditions, DEE was determined over the same period of time by the DLW, the factorial and the HR recording methods during 17, 14 and 4 d respectively. Mean free-living DEE values for men estimated using the DLW, the factorial and the HR recording methods were 12·8 (sd 3·1), 12·7 (sd 2·2) and 13·5 (sd 2·7) MJ/d respectively. Mean free-living DEE values for women were 9·6 (sd 0·8), 8·8 (sd 1·2) and 10·2 (sd 1·5) MJ/d respectively. No significant differences were found between the three methods for either sex, using the Bland & Altman (1986) test. Mean differences in DEE of men were -0·9 (sd 11·8) % between the factorial and DLW methods, and +4·7 (sd 16·1) % between the HR recording and DLW methods. Similarly, in women, mean differences were -7·7 (sd 12·7) % between the factorial and DLW methods, and +5·9 (sd 8·8) % between the HR recording and DLW methods. It was concluded that the factorial and the HR recording methods are satisfactory alternatives to the DLW method when considering the mean DEE of a group of subjects. Furthermore, mean energy costs of activities calculated in the present study using the factorial method were shown to be suitable for determining free-living DEE of elderly people when the reference value (i.e. sleeping metabolic rate) is accurately measured.
The effects of high oral magnesium supplementation on blood pressure, serum lipids and related variables in apparently healthy Japanese subjects
Authors: Itoh Kazue , Kawasaki Terukazu , Nakamura Motoomi
Published: June 2005

In a double-blind, placebo-controlled study, thirty-three subjects were allocated to undergo either a 4-week treatment with oral Mg supplementation (Mg(OH)2; 411–548 mg Mg/d) or a placebo. The urinary excretion of Mg increased significantly in both the first 2 weeks and the following 2 weeks of Mg supplementation, while the urinary Na excretion also increased significantly over the experimental period. The systolic and diastolic blood pressure values decreased significantly in the Mg group, but not in the placebo group. The urinary aldosterone excretion and packed cell volume increased significantly during the last 2 weeks of the experimental period compared with the run-in period and first 2 weeks of supplementation. There was a statistically significant positive correlation between the values for urinary noradrenaline excretion and diastolic blood pressure at the end of the supplementation period (both expressed as a percentage of the run-in value). Statistically significant increases in lecithin-cholesterol acyltransferase (EC2.3.1.43; LCAT), HDL-cholesterol and apolipoprotein AI were also observed after Mg supplementation. A significant positive correlation was observed between the levels of LCAT and urinary Mg excretion for the experimental period (expressed as a percentage of the run-in value). The total cholesterol: HDL-cholesterol ratio decreased significantly during the last 2 weeks of Mg supplementation compared with the first 2 weeks and the run-in periods, but this did not occur in the placebo group. These results suggest that Mg supplementation may lower blood pressure through the suppression of the adrenergic activity and possible natriuresis, while also improving the serum lipids through the activation of LCAT in human subjects.
Influence of malaria on markers of iron status in children: implications for interpreting iron status in malaria-endemic communities
Authors: Das Bhabani S. , Thurnham David I. , Das Deba B.
Published: June 2005

To investigate Fe nutritional indices in malaria infection in children, haematology (blood haemoglobin, plasma ferritin, transferrin, Fe, and transferrin saturation), acute phase markers (albumin and caeruloplasmin) and liver function tests were studied in fifty consecutive cases of severe and mild falciparum malaria, fifty matched controls and twenty-three cases of asymptomatic malaria. Blood haemoglobin and transferrin were lower, while ferritin and transferrin saturation were higher, in groups with symptomatic malaria in comparison with the control group. The differences were greatest with the severest form of the disease. There were no differences between any of the groups in plasma Fe. Plasma transferrin correlated directly with albumin in asymptomatic, mild and severe malaria groups (r0.48, 0.65 and 0.83;P< 0.05,P< 0.01 andP< 0.001 respectively), and inversely with caeruloplasmin (r−0.65, −0.34 and −0.43;P< 0.01,P< 0.05 andP< 0.01 respectively). For ferritin, the correlation was inverse with albumin (r−0.65, −0.57 and −0.64;P< 0.01,P< 0.001 andP< 0.001 respectively and direct with caeruloplasmin (r0.83, 0.21 and 0.49,P< 0.001, NS andP< 0.001 respectively). Multiple regression analysis on data from all patients combined indicated that albumin, and to a lesser extent alanine aminotransferase (EC2.6.1.2) activity, explained 62 % of the variance in transferrin. Caeruloplasmin, parasite count and albumin explained 59 % of the variance in ferritin, and transferrin and unconjugated bilirubin explained 62 % of the variance in Fe values. In conclusion, these data suggest that low transferrin and high ferritin values are primarily due to the acute phase response. High transferrin saturation and lack of differences in plasma Fe between the groups are probably due to Fe released from lysed erythrocytes. Finally, in both symptomatic and asymptomatic malaria, indices of Fe status can be misleading and may be especially problematic in community studies in malaria-endemic areas where asymptomatic malaria may be common.
Effect of 3 months vitamin E supplementation on indices of the cellular and humoral immune response in elderly subjects
Authors: De Waart Frouwkje G. , Portengen Lützen , Doekes Gert , Verwaal Corné J. , Kok Frans J.
Published: June 2005

It has been suggested that decreased immune responsiveness in the elderly may be counteracted by the antioxidant vitamin E. In a 3-month double-blind placebo-controlled intervention trial among elderly subjects aged 65 years and over we studied the effects of a daily dose of 100 mg dl-α-tocopheryl acetate on the cellular immune responsiveness (n52) measured by thein vitroresponse of peripheral blood mononuclear cells (PBMC) to the mitogens concanavalin A (ConA) and phytohaemagglutinin (PHA). Also effects on the humoral immune responsiveness (n74) were investigated by measuring immunoglobulin (Ig)G, IgG4 and IgA antibody concentrations against various common antigens. In the vitamin E group plasma α-tocopherol increased by 51 % (P= 0.0001) during intervention whereas no significant changes were observed in the control group. Initial proliferative PBMC responses differed between the vitamin E group and the control group whereas all other baseline characteristics were comparable. No significant changes were observed in cellular immune responsiveness when adjusted for initial values in either the control group or the vitamin E group and, after the trial period, responses in the two groups were not significantly different. Similarly, in the vitamin E group no significant changes were found in levels of IgG and IgA raised againstPenicilliumor IgG4 raised against egg, milk, or wheat proteins. In the control group small but significant increases in IgG anti-Penicillium(P<0.05) and decreases in IgG4 against milk proteins (P< 0.05) were observed. Thus, the results of this study performed with the relatively low dose of 100 mg dl-α-tocopheryl acetate do not support the claims of a beneficial effect of vitamin E intake on the overall immune responsiveness of elderly subjects.
The possible significance of parallel changes in plasma lutein and retinol in Pakistani infants during the summer season
Authors: Thurnham D. I. , Northrop-Clewes C. A. , Paracha P. I. , McLoone U. J.
Published: June 2005

Recent evidence suggests that plasma lutein is better correlated than either β-carotene or lycopene with its respective carotenoid intake and therefore may be a better marker of vegetable intake than either β-carotene or lycopene. In the study reported in this paper, measurements of plasma carotenes and retinol were made in infants from two villages near Peshawar in the North West Frontier Province, Pakistan, in July and November 1993. The approximate age at the start was 14 months, and 101 boys and ninety girls completed the study. Of the usual plasma carotenes, only lutein was measurable in all samples and was correlated with retinol in both boys (r0.38,P< 0.0001;r0.35,P< 0.001) and girls (r0.21,P= 0.038;r0.307,P= 0.003) at the two time points respectively. In addition, the change in lutein was even more strongly correlated with the change in retinol in both boys (r0.453,P<0.0001) and girls (r0.439,P< 0.0001). In August β-carotene was measurable in approximately 8 % of samples and this increased to 31 % in November but there was no correlation between β-carotene and retinol at any time. There were negligible amounts of lycopene and β-cryptoxanthin in plasma at both time points. The mean concentration of plasma retinol in the infants was 0.66 μmol/l at baseline and 59 % of the infants had retinol concentrations < 0.7 μmol/l. In addition, there were fifteen infants whose levels were below 0.35 μmol/l suggesting that vitamin A status in the population was marginal. Food intake of the infants was not monitored in the present study but breast feeding continues for up to 2 years in this part of Pakistan and most infants would be weaned onto selected foods eaten by the family. The close correlation between plasma lutein and retinol suggests that the increase in retinol over the summer season may be attributable to an increased availability of green vegetables to the families. The source of lutein to the infants is most likely to be the breast milk since such vegetables are unlikely to be given to infants except to suck as a weaning food. The results may indicate the potential usefulness of plasma lutein as a marker of changes in vegetable intake and changes in vitamin A status in Third World infants and children.
Granulated polyamide as external marker to estimate total faecal excretion of grazing cattle in extensive management systems
Authors: Mahler Friedrich , Schlecht Eva , Sangare Mamadou , Becker Klaus
Published: June 2005

Granulated polyamide (PA) was tested for use as an external marker to estimate faecal DM (FDM) excretion of Zebu cattle (Bos indicus). The study was conducted in Mali, using seven and eighteen animals respectively in four field trials and six indoor experiments. Cattle ate fresh or dry pasture vegetation and half the animals were additionally supplemented with crop byproducts. Gelatine capsules containing 35, 40 or 45 g PA were administered orally at 12 h intervals. Estimates of FDM were based on the average marker concentration in faeces and were correlated with the actual excretion measured by total faecal collection. The pre-measurement period required to establish equilibrium for regular marker dosing was determined at 4 d. Except for diets with a N content of less than 9·26 g/kg organic matter, marker recovery averaged 98·1 (se 0·93) % (n 62), and was not influenced by diet composition and the quantity of feed ingested (P > 0·05). Estimates of FDM based on average PA concentrations in faecal samples were correlated to the actual excretion with r 0·98 (n 62; P ≤ 0·001). Since the PA concentration in individual faecal grab-samples is not correlated with either sample mass or sampling time, accurate estimates of FDM require a grab-sampling schedule that covers the 24 h day. However, estimates of FDM were found to be acceptable if calculations are based on the average PA concentration in the sub-total of samples collected during the day or during night respectively (r 0·95, n 29; P ≤ 0·001 in both cases). It is concluded that the use of PA marker is a simple and inexpensive method resulting in reliable estimates of FDM. Since sophisticated analytical procedures are not required to recover PA in faecal samples, the marker is particularly suitable for application in extensive grazing systems and in studies conducted in less-developed countries.
Influences of dietary methionine and cysteine on metabolic responses to immunological stress byEscherichia colilipopolysaccharide injection, and mitogenic response in broiler chickens
Authors: Takahashi K. , Ohta N. , Akiba Y.
Published: June 2005

The present experiments were conducted to investigate influences of dietary methionine and cysteine on metabolic responses to immunological stress induced by Escherichia coli lipopolysaccharide (LPS) injection, and concanavalin A (Con A)-induced mononuclear cell (MNC) proliferation in male broiler chickens. In Expt 1, chicks (12 d of age) were fed on a S amino acid (SAA)-deficient diet (5.6 g SAA/kg diet) or on three kinds of SAA-sufficient diet (9.3 g SAA/kg diet; low-, medium- and high-cysteine diets) which contained 2.8, 4.65 and 6.5 g cysteine/kg diet, respectively. Plasma a-1 acid glycoprotein (AGP) concentration and interleukin (IL)-1-like activity in chicks fed on the SAA-deficient diet were lower following a single injection of LPS than those in chicks fed on the SAA-sufficient diets. At 16 h after LPS injection, plasma Fe and Zn concentrations and body weight were reduced, but AGP concentration and IL-1-like activity in plasma were significantly increased. These changes in body weight, plasma Zn and Fe concentrations following injection of LPS were not affected by dietary methionine:cysteine ratios. Plasma AGP concentration and IL-1-like activity in chicks fed on the high-cysteine diet were, however, greater than those in chicks fed on the other diets following a single injection of LPS. In Expt 2, chicks (7 d of age) were fed on the SAA-sufficient diets as in Expt 1 for 10 d. MNC proliferation in spleen induced by Con A in chicks fed on the high-cysteine diet was greater than that in chicks fed on the low- or medium-cysteine diet. The results suggest that dietary cysteine has an impact on the immune and inflammatory responses.
Liver intracellular L-cysteine concentration is maintained after inhibition of the trans-sulfuration pathway by propargylglycine in rats
Authors: Triguero Ana , Barber Teresa , GarcÍa Concha , Puertes Inmaculada R. , Sastre Juan , ViÑa Juan R.
Published: June 2005

To study the fate ofl-cysteine and amino acid homeostasis in liver after the inhibition of the trans-sulfuration pathway, rats were treated with propargylglycine (PPG). At 4 h after the administration of PPG, liver cystathionase (EC4.4.1.1) activity was undetectable,l-cystathionine levels were significantly higher,l-cysteine was unchanged and GSH concentration was significantly lower than values found in livers from control rats injected intraperitoneally with 0.15 M-NaCl. The hepatic levels of amino acids that are intermediates of the urea cycle,l-ornithine,l-citrulline andl-arginine and blood urea were significantly greater. Urea excretion was also higher in PPG-treated rats when compared with control rats. These data suggest a stimulation of ureagenesis in PPG-treated rats. The inhibition of γ-cystathionase was reflected in the blood levels of amino acids, because the L-methionine:l-cyst(e)ine ratio was significantly higher in PPG-treated rats than in control rats; blood concentration of cystathionine was also greater. Histological examination of liver and kidney showed no changes in PPG-treated rats when compared with controls. The administration of N-acetylcysteine (NAC) to PPG-treated rats reversed the changes in blood urea and in liver GSH. These data suggest that when liverl-cysteine production was impaired by the blockage of the trans-sulfuration pathway, the concentration of this amino acid was maintained mainly by an increase in protein degradation and by a depletion in GSH concentration that may sparel-cysteine.
Stability of the mRNA encoding some pancreatic hydrolases is modulated by dietary protein intake in the rat
Authors: Carreira Suzanne , Fueri Christian , Chaix Jean-Claude , Puigserver Antoine
Published: June 2005

Wistar rats fed on either a high-protein or a protein-free diet were examined to determine their pancreatic hydrolase mRNA stabilities in comparison with those of control animals receiving a standard diet. Actinomycin D was used to inhibit transcription and, after isolating the pancreatic RNA, the specific messengers were quantified by performing dot-blot hybridization with cDNA probes. In the rats fed on a high-protein diet, only the half-lives of anionic trypsinogen I and elastase I (EC3.4.21.36) were affected. Interestingly, when rats were fed on the protein-free diet, most of the hydrolase mRNA half-lives showed changes, except that corresponding to lipase. In these rats, the half-life values of the mRNA coding for anionic trypsinogen I, chymotrypsinogen and procarboxypeptidase B increased, in sharp contrast with those of the amylase and elastase I mRNA, which decreased. These results strongly suggest that the mechanism whereby the biosynthesis of pancreatic hydrolases is regulated, depending on the presence or absence of proteins in the diet, is not unique and provide evidence that the stability of mRNA encoding most, if not all, the hydrolases in pancreatic cells is modulated by the dietary protein content.
Marked alterations in circulating inflammatory cells during cardiomyopathy development in a magnesium-deficient rat model
Authors: Kurantsin-Mills Joseph , Cassidy Marie M. , Stafford Richard E. , Weglicki William B.
Published: June 2005

Rodents fed on a Mg-deficient (Mg-D) diet develop cardiomyopathic lesions, as well as other types of cardiovascular dysfunction. In the rat, inflammatory cell infiltration of the myocardium begins to occur by week 1, and the lesions develop extensively in the third and fourth weeks on the Mg-D diet. Although the aetiologic mechanisms of Mg-D cardiomyopathy are unknown, we have previously reported that once plasma Mg is markedly reduced, one of the earliest molecular markers of the pathophysiological process is elevation of plasma substance P, calcitonin gene-related peptide and prostaglandin E2, followed by histamine and the inflammatory cytokines (interleukin-1, interleukin-6, and tumor necrosis factor-α). In order to evaluate the potential role of specific circulating inflammatory cell subpopulations in the mechanisms underlying pathophysiological changes observed in Mg-deficiency-induced cardiomyopathy, we analysed these cells by flow cytochemistry. Leucocyte subpopulation pools increased progressively in the Mg-D rats. Elevated circulating levels of neutrophils and lymphocytes appeared to contribute to both the acute (week 1–2) and chronic phases (week 3–4) of the inflammatory responses; monocytes, eosinophils, basophils and large unstained cells which are lymphoid in stained smears, on the other hand, increased significantly in the third and fourth weeks and thus contributed to the chronic inflammatory phase. Changes in the circulating leucocyte subpopulations paralleled the chronological progression of the cardiomyopathic lesions, particularly in weeks 3 and 4. Since a pronounced neutrophilia preceded leucocyte infiltration and deposition within the myocardial tissue, modifications of the microvascular barrier may be a prerequisite for cardiomyopathy in this model of neurogenic inflammation.
Vitamin C status and collagen cross-link ratios in Gambian children
Authors: Munday K. , Fulford A. , Bates C. J.
Published: June 2005

Vitamin C (ascorbate) is essential for hydroxylation of prolyl and lysyl residues in nascent collagen, the failure of which leads to connective tissue lesions of scurvy. Of the pyridinium-type cross-links in mature collagen, pyridinoline requires more hydroxylysyl residues than does deoxypyridinoline. Our study tested the hypothesis that pyridinoline:deoxypyridinoline ratios in urinary degradation products may vary with ascorbate status in man. These ratios were compared between British and Gambian prepubertal boys, mean age 8·3 years, and in Gambian boys between two seasons with contrasting ascorbate availability. The mean cross-links ratio in 216 British boys was 4·36 (sd 0·71), significantly greater (P<0·0001) than in sixty-two Gambian boys: 3·83 (sd 0·52). In the Gambians the cross-links ratio was significantly higher in the dry season (with high ascorbate intake and status) than in the rains (with low intake and status). A 7-week controlled intervention was carried out in Gambian boys during the rainy season (the ‘hungry’ season, when vitamin C-containing foods are virtually unavailable): 100 mg ascorbate/d was given to one group of thirty-two Gambian boys and placebo to another group. The intervention did not, however, significantly alter the cross-link ratio, possibly because the response time and/or intervention–response delay is >7 weeks. If confirmed, the putative association between ascorbate and collagen cross-link ratios in man could become the basis for a functional test for adequacy of ascorbate status.
High rates of exogenous carbohydrate oxidation from a mixture of glucose and fructose ingested during prolonged cycling exercise
Authors: Jentjens Roy L. P. G. , Jeukendrup Asker E.
Published: June 2005

A recent study from our laboratory has shown that a mixture of glucose and fructose ingested at a rate of 1·8 g/min leads to peak oxidation rates of approximately 1·3 g/min and results in approximately 55 % higher exogenous carbohydrate (CHO) oxidation rates compared with the ingestion of an isocaloric amount of glucose. The aim of the present study was to investigate whether a mixture of glucose and fructose when ingested at a high rate (2·4 g/min) would lead to even higher exogenous CHO oxidation rates (>1·3 g/min).Eight trained male cyclists (VO2max: 68±1 ml/kg per min) cycled on three different occasions for 150 min at 50 % of maximal power output (60±1 % VO2max) and consumed either water (WAT) or a CHO solution providing 1·2 g/min glucose (GLU) or 1.2 g/min glucose+1·2 g/min fructose (GLU+FRUC). Peak exogenous CHO oxidation rates were higher (P<0·01) in the GLU+FRUC trial compared with the GLU trial (1·75 (se 0·11) and 1·06 (se 0·05) g/min, respectively). Furthermore, exogenous CHO oxidation rates during the last 90 min of exercise were approximately 50 % higher (P<0·05) in GLU+FRUC compared with GLU (1·49 (se 0·08) and 0·99 (se 0·06) g/min, respectively). The results demonstrate that when a mixture of glucose and fructose is ingested at high rates (2·4 g/min) during 150 min of cycling exercise, exogenous CHO oxidation rates reach peak values of approximately 1·75 g/min.
Response of circulating leptin to Ramadan daytime fasting: a circadian study
Authors: Bogdan André , Bouchareb Belal , Touitou Yvan
Published: June 2005

Although the effects of short-term fasting on serum leptin concentrations are known, those resulting from long-lasting modifications of food intake schedule, as during the month of Ramadan, have not yet been extensively studied. Therefore, serum concentrations of leptin were measured around the clock at 4-hourly intervals before the beginning of Ramadan and on the twenty-third day of Ramadan daytime fasting in ten male subjects keeping the same usual activity pattern and general synchronisation in both situations. Time series were analysed with repeated measures ANOVA and Cosinor. No significant changes in amplitude or 24 h mean concentration were seen, but significant shifts of 5 h 30 min in peak and trough serum leptin levels were found on the twenty-third day of Ramadan.
Early enteral feeding compared with parenteral nutrition after oesophageal or oesophagogastric resection and reconstruction
Authors: Gabor S. , Renner H. , Matzi V. , Ratzenhofer B. , Lindenmann J. , Sankin O. , Pinter H. , Maier A. , Smolle J. , Smolle-Jüttner F. M.
Published: June 2005

After resective and reconstructive surgery in the gastrointestinal tract, oral feeding is traditionally avoided in order to minimize strain to the anastomoses and to reduce the inherent risks of the postoperatively impaired gastrointestinal motility. However, studies have given evidence that the small bowel recovers its ability to absorb nutrients almost immediately following surgery, even in the absence of peristalsis, and that early enteral feeding would preserve both the integrity of gut mucosa and its immunological function. The aim of this study was to investigate the impact of early enteral feeding on the postoperative course following oesophagectomy or oesophagogastrectomy, and reconstruction. Between May 1999 and November 2002, forty-four consecutive patients (thirty-eight males and six females; mean age 62, range 30–82) with oesophageal carcinoma (stages I–III), who had undergone radical resection and reconstruction, entered this study (early enteral feeding group; EEF). A historical group of forty-four patients (thirty-seven males and seven females; mean age 64, range 41–79; stages I–III) resected between January 1997 and March 1999 served as control (parenteral feeding group; PF). The duration of both postoperative stay in the Intensive Care Unit (ICU) and the total hospital stay, perioperative complications and the overall mortality were compared. Early enteral feeding was administered over the jejunal line of a Dobhoff tube. It started 6 h postoperatively at a rate of 10 ml/h for 6 h with stepwise increase until total enteral nutrition was achieved on day 6. In the controls oral enteral feeding was begun on day 7. If compared to the PF group, EEF patients recovered faster considering the duration of both stay in the ICU and in the hospital. There was a significant difference in the interval until the first bowel movements. No difference in overall 30 d mortality was identified. A poor nutritional status was a significant prognostic factor for an increased mortality. Early enteral feeding significantly reduces the duration of ICU treatment and total hospital stay in patients who undergo oesophagectomy or oesophagogastrectomy for oesophageal carcinoma. The mortality rate is not affected.
Defining best practice for microarray analyses in nutrigenomic studies
Authors: Garosi Paola , De Filippo Carlotta , van Erk Marjan , Rocca-Serra Philippe , Sansone Susanna-Assunta , Elliott Ruan
Published: June 2005

Microarrays represent a powerful tool for studies of diet–gene interactions. Their use is, however, associated with a number of technical challenges and potential pitfalls. The cost of microarrays continues to drop but is still comparatively high. This, coupled with the complex logistical issues associated with performing nutritional microarray studies, often means that compromises have to be made in the number and type of samples analysed. Additionally, technical variations between array platforms and analytical procedures will almost inevitably lead to differences in the transcriptional responses observed. Consequently, conflicting data may be produced, important effects may be missed and/or false leads generated (e.g. apparent patterns of differential gene regulation that ultimately prove to be incorrect or not significant). This is likely to be particularly true in the field of nutrition, in which we expect that many dietary bioactive agents at nutritionally relevant concentrations will elicit subtle changes in gene transcription that may be critically important in biological terms but will be difficult to detect reliably. Thus, great care should always be taken in designing and executing microarray studies. This article seeks to provide an overview of both the main practical and theoretical considerations in microarray use that represent potential sources of technical variation and error. Wherever possible, recommendations are made on what we propose to be the best approach. The overall aims are to provide a basic framework of advice for researchers who are new to the use of microarrays and to promote a discussion of standardisation and best practice in the field.
Increasing ursodeoxycholic acid in the enterohepatic circulation of pigs through the administration of living bacteria
Authors: Lepercq Pascale , Hermier Dominique , David Olivier , Michelin Rachel , Gibard Clotilde , Beguet Fabienne , Relano Purification , Cayuela Chantal , Juste Catherine
Published: June 2005

We investigated the feasibility of increasing ursodeoxycholic acid (UDCA) in the enterohepatic circulation of pigs by administering living bacteria capable of epimerising endogenous amidated chenodeoxycholic acid (CDCA) to UDCA. We first demonstrated that combining Bifidobacterium animalis DN-173 010, as a bile salt-hydrolysing bacterium, and Clostridium absonum ATCC 27555, as a CDCA to UDCA epimerising bacterium, led to the efficient epimerisation of glyco- and tauro-CDCA in vitro, with respective UDCA yields of 55·8 (se 2·8) and 36·6 (se 1·5)%. This strain combination was then administered to hypercholesterolaemic pigs over a 3-week period, as two daily preprandial doses of either viable (six experimental pigs) or heat-inactivated bacteria (six controls). The main effects of treatment were on unconjugated bile acids (P=0·035) and UDCA (P<0·0001) absorbed into the portal vein, which increased 1·6–1·7- and 3·5–7·5-fold, respectively, under administration of living compared with inactivated bacteria. In bile, UDCA did not increase significantly, but the increase in biliary lithocholic acid with time in the controls was not observed in the experimental pigs (P=0·007), and the same trend was observed in faeces. All other variables (biliary lipid equilibrium, plasma lipid levels and partition of cholesterol between the different lipoprotein classes) remained unaffected by treatment throughout the duration of the experiment. In conclusion, it is feasible to increase the bioavailability of UDCA to the intestine and the liver by administering active bacteria. This may represent an interesting new probiotic activity, provided that in future it could be expressed by a safe food micro-organism.
Association of fatty acids in serum phospholipids with hay fever, specific and total immunoglobulin E
Authors: Kompauer Iris , Demmelmair Hans , Koletzko Berthold , Bolte Gabriele , Linseisen Jakob , Heinrich Joachim
Published: June 2005

The dietary intake of certain fatty acids might contribute to the development of allergic diseases such as hay fever and asthma. We investigated the association between the concentrations of fifteen fatty acids in serum phospholipids, as a marker of dietary intake and metabolism, and hay fever, allergic sensitisation and total IgE in adults. Data from a population-based cross-sectional study on respiratory health, including the measurement of fatty acids in the serum phospholipids of 740 adults between 20 and 64 years of age, were analysed. Positive associations were found between hay fever and arachidonic acid, and allergic sensitisation and oleic acid. No other fatty acids showed any association with hay fever or allergic sensitisation. Elevated levels of total IgE were not related to fatty acids. Concentrations of long-chain n-3 fatty acids, trans fatty acids or saturated fatty acids in serum phospholipids were not associated with allergic diseases in adults in this study. The present result on the association between hay fever and arachidonic acid is consistent with current hypotheses but warrants further research.
Secondary infection ofNippostrongylus brasiliensisin lactating rats is sensitive to dietary protein content
Authors: Houdijk Jos G. M. , Jessop Neil S. , Knox David P. , Kyriazakis Ilias
Published: June 2005

Lactating mammals usually exhibit a breakdown of immunity to parasites, i.e. they have larger worm burdens than their non-lactating counterparts. Here, we tested the hypothesis that a secondary infection withNippostrongylus brasiliensisin lactating rats is sensitive to dietary protein content. We also tested whether this infection affects host food intake. Rats either remained uninfected throughout the study or were given a single infection before mating (primary infection) and re-infected on day 2 of lactation (secondary infection) with 1600 infective larvae. Infected rats were fed foods during lactation formulated to supply 100 (low protein; LP), 200 (medium protein; MP) or 300 (high protein; HP) g crude protein per kg DM; non-infected rats were fed either the LP or HP food. Litter size was standardized to ten pups between parturition (day 0) and secondary infection (day 2). Ten days after secondary infection, MP and HP rats had excreted fewer nematode eggs, and had fewer adult nematodes in their small intestine and nematode eggs in their colon than the LP rats. Primary infection increased food intake in late pregnancy, and increased maternal body weight and litter size at parturition. Secondary infection did not affect mean food intake, maternal and litter weight, although food intake was reduced for 1 d following infection. These results support the view that a secondary infection withN. brasiliensisis sensitive to dietary protein content, and that the latter infection does not impair lactational performance. Future studies may focus on elucidating the nutritional sensitivity of immune responses underlying the reduced secondaryN. brasiliensisinfection.
Dietary whey protein increases liver and skeletal muscle glycogen levels in exercise-trained rats
Authors: Morifuji Masashi , Sakai Kensuke , Sanbongi Chiaki , Sugiura Katsumi
Published: June 2005

We investigated the effect of different types of dietary protein on glycogen content in liver and skeletal muscle of exercise-trained rats. Twenty-four male Sprague-Dawley rats (approximately 100 g;n6 per group) were divided into sedentary or exercise-trained groups with each group being fed either casein or whey protein as the source of dietary protein. Rats in the exercised groups were trained during 2 weeks using swimming exercise for 120 min/d, 6 d/week. Exercise training resulted in an increase in the skeletal muscle glycogen content. Furthermore, the whey protein group significantly increased the skeletal muscle glycogen content compared with the casein group. The increase in glycogen content in liver was significantly greater in rats fed the whey protein diet compared with those fed the casein diet. We also found that the whey protein diet increased the activity of liver glucokinase, whereas it decreased the activities of 6-phosphofructokinase and pyruvate kinase compared with the casein diet. However, hepatic total glycogen synthase activity and mRNA expression were similar with the two diets. In the skeletal muscle, whey protein decreased only 6-phosphofructokinase activity compared with casein. Total glycogen synthase activity in the skeletal muscle in the whey protein group was significantly higher than that in the casein group. The present study is the first to demonstrate that a diet based on whey protein may increase glycogen content in liver and skeletal muscle of exercise-trained rats. We also observed that whey protein regulated glycogen metabolism in these two tissues by different mechanisms.
Catabolism through the threonine dehydrogenase pathway does not account for the high first-pass extraction rate of dietary threonine by the portal drained viscera in pigs
Authors: Floc'h Nathalie Le , Sève Bernard
Published: June 2005

In pigs the extensive threonine utilization by the splanchnic tissues explains the relative inefficiency of dietary threonine conversion for body protein accretion. Two experiments were conducted to estimate the contribution of the portal drained viscera (PDV) and the liver to threonine metabolism and especially catabolism in growing pigs. In the first experiment, four pigs were surgically prepared for chronic catheter insertion in the portal, hepatic and jugular veins and in the carotid artery. They were continuously infused with l-[1-13C]threonine through the jugular catheter. The PDV and total splanchnic viscera (PDV and the liver) extracted 14·3 and 18·8 % of arterial threonine input, respectively. In a second experiment, we studied the metabolism of dietary threonine in the PDV and the liver in six female growing pigs. Animals were surgically prepared as in the first experiment except that l-[1-13C]threonine and [15N]glycine were continuously infused in the duodenum for 10 h. Unlabelled and labelled threonine and glycine PDV, liver and splanchnic tissues balance were calculated from plasma samples taken during the last 2 h of this infusion. Splanchnic tissues extracted 60 % of infused labelled threonine, 88 % of which was extracted by PDV so that threonine extraction by the liver was low. Both the liver and the pancreas can degrade threonine through the l-threonine 3-dehydrogenase pathway but not the intestine. Our data suggest that threonine catabolism through the l-threonine 3-dehydrogenase pathway was only a minor component of total threonine utilization in the splanchnic tissues.
The effect of dietary vitamin E and fatty acid supplementation of pregnant and lactating ewes on placental and mammary transfer of vitamin E to the lamb
Authors: Capper Judith L. , Wilkinson Robert G. , Kasapidou Eleni , Pattinson Sandra E. , Mackenzie Alexander M. , Sinclair Liam A.
Published: June 2005

The present study investigated the effect of maternal vitamin E and fatty acid supplementation on lamb antioxidant status. Forty-eight ewes were fed one of four concentrate diets supplemented with a basal (50 mg/kg) or supranutritional (500 mg/kg) level of vitamin E plus a source of either saturated fat (Megalac®; Volac Ltd, Royston, Hertfordshire, UK) or long-chain PUFA (fish oil) from 6 weeks prepartum until 4 weeks postpartum. Blood samples were taken from ewes and lambs at intervals throughout the experiment and, at parturition, muscle, brain and blood samples were obtained from twelve lambs (three per treatment). Colostrum and milk samples were obtained at 12 h and 21 d after parturition, respectively. Supranutritional vitamin E supplementation of the ewe significantly increased concentrations of vitamin E in neonatal lamb tissues although plasma concentrations were undetectable. A significant increase in lamb birth weight resulted from increasing the dietary vitamin E supply to the ewe. Furthermore, maternal plasma, colostrum and milk vitamin E concentrations were increased by vitamin E supplementation, as were lamb plasma concentrations at 14 d of age. Neonatal vitamin E status was not significantly affected by fat source although plasma vitamin E concentrations in both ewes and suckling lambs were reduced by fish oil supplementation of the ewe. Fish oil supplementation reduced vitamin E concentrations in colostrum and milk and the activity of glutathione peroxidase in suckling lambs. The data suggest that the vitamin E status of the neonatal and suckling lamb may be manipulated by vitamin E supplementation of the ewe during pregnancy and lactation.
The National School Fruit Scheme produces short-term but not longer-term increases in fruit consumption in primary school children
Authors: Wells Lesley , Nelson Michael
Published: June 2005

The National School Fruit Scheme (NSFS) provides one free piece of fruit each school day to children, aged 4 to 6 years, attending state schools in England. The aims of the present study were to determine if NSFS was associated with a higher fruit consumption in infant school children (4–6 years old), and to assess whether fruit consumption was higher in junior school children (7–8 years old) who had received free fruit as infants compared with those who had not. The present cross-sectional study involved seventeen schools, eight in the NSFS (study schools) and nine not in the NSFS (control schools). Study and control schools were selected in areas of similar levels of deprivation. All schools were on the outskirts of London in Southeast England. A retrospective 24 h food tick list was given to each pupil in Reception to Year 4 to take home for their parents to complete and return. Response rate was 51 %. Median total fruit consumption (excluding fruit juice) in infants receiving free fruit was 117 g/d compared with 67 g/d in infants not receiving free fruit (P<0·001). Median consumption in juniors who had received free fruit at school as infants did not differ from those who had not (83 g/d v. 86 g/d). The NSFS has increased fruit consumption in infant school children. It does not appear to have longer-term effects in junior school children. If the scheme is to affect dietary habits and improve health in the long term, further interventions will be needed.