bluuebunny/crossref_metadata_2025 huggingface dataset:
Iron sufficiency in the population of Northern Ireland: estimates from blood measurements
Authors: Strain J. J. , Thompson K. A. , Barker M. E. , Carville D. G. M.
Published: September 2005

Estimates of iron status in a random sample (218 men, 283 women) of the Northern Ireland population (aged 18–64 years) were obtained from blood measurements. Multiple criteria were used to determine Fe deficiency and body Fe stores were calculated as an index of Fe sufficiency. Three distinct groups with respect to Fe stores were identified on the basis of sex and menstrual status. Estimates of body Fe stores, mean (and SD), were 13.4 (SD 5.97), 5.3 (SD 6.09) and 8.5 (SD 6.72) mM for men, women aged 18–44 years and women aged 45–64 years respectively. The prevalence of Fe-deficincy was low. ranging from 0.5% in men to 6.6% and 4.6% in the younger and older women respectively. The prevalence of Fe deficiency was low in men (1.4%) and older women (5.7%) rising to 11.0% in the younger group of women. The disproportionately elevated serum ferritin relative to transferrimn saturation supported the suggestion that chronic inflammation might have influenced Fe status measurements in men and older women.
Binding of zinc and calcium to inositol phosphates (phytate) in vitro
Authors: Simpson C. J. , Wise A.
Published: September 2005

Inositol compounds with three to five phosphate groups (IP3–IP5) were produced by hydrolysis of phytate (inositol hexaphosphate, IP6) and their binding affinities for calcium and zinc investigated at neutral pH with relative concentrations that had been found in a range of students' meals. Zn solubility was negligible at many of these concentrations, with less Zn bound to precipitates of Ca-IP6 than Ca-IP5. The capacity to precipitate Zn at these ratios fell between IP5 and IP3. Zn was partially desorbed by soluble chelators (histidine and picolinate), especially when it had been adsorbed to preformed Ca-IP precipitates. A lower proportion of Zn was accessible to soluble chelators from Ca-IP4 than the other compounds. IP3-IP4 were hydrolysed. by phytase more readily than IP5–IP6.
Linear programming and pediatric dietetics
Authors: Colavita Ciro , D'orsi Renato
Published: September 2005

The composition of 500 foods has been stored in a computer in order to analyse a child's diet. The methodology of operations research is applied to a very simple problem: a diet with only two foods. The geometrical representation of the ‘feasible region’ and of the ‘objective function’ is illustrated. One of the analytical methods employable with many variables (foods) is considered. This method was used in trying to find diets allowing for the preferential use of selected foods while respecting recommended dietary allowances, the tastes of the child and other constraints. The theoretical difficulty of transferring this methodology to pediatric dietetics was examined. We solved a simple case utilizing this procedure.
Dietary behaviours and sociocultural demographics in Northern Ireland
Authors: Barker M. E. , McClean S. I. , Thompson K. A. , Reid N. G.
Published: September 2005

Subjects aged 16–64 years (592; 258 men and 334 women), randomly selected from the population of Northern Ireland, kept a 7 d weighed record of all food and drink consumed. Social, personal and anthropometric data were also collected. From the weighed records food consumption was described in terms of forty-one food groups. Using principal components analysis, four distinct dietary patterns were generated which were identified as a traditional diet, a cosmopolitan diet, a convenience diet and a ‘meat and two veg’ diet. These dietary patterns were then correlated with sociocultural, lifestyle and anthropometric variables. It is clear that dietary behaviour is influenced by a number of inter-related sociocultural demographics and that identifiable population groups in Northern Ireland have different dietary behaviours.
Nitrogen and purine metabolism at varying energy and protein supplies in sheep sustained on intragastric infusion
Authors: Lindberg J. E. , Jacobsson K.-G.
Published: September 2005

Wether sheep were fitted with rumen fistulas and polyethylene tubes to the abomasum and were given all nutrients by intragastric infusion. In Expt 1 volatile fatty acids (VFA) were given at 340, 450 and 630 kJ gross energy (GE)/kg metabolic weight (W0.75) and protein at 0, 150, 300, 600, 900 and 1500 mg nitrogen/kg W0.75. In Expt 2 VFA were infused at 450 kJ GE/kg W0.75and protein at 0 and 300 mg N/kg W0.75. At all levels of energy intake in Expt 1 the N retention was significantly (P< 0.01) related to N intake. The basal N requirement was estimated to be 281 mg (SE 21.8) N/kg W0.75at 340 kJ VFA/kg W0.75, 226 (SE 21.8) mg N/kg W0.75at 450 kJ VFA/kg W0.75and 207 (SE 19.4) mg N/kg W0.75at 630 kJ VFA/kg W0.75. Plasma urea concentrations varied markedly in relation to protein intake and to energy supply. On the other hand plasma ammonia, glucose, insulin and creatinine concentrations, and also urinary excretion of purine derivatives and creatinine were not significantly affected by the treatments imposed. It was concluded that the urinary excretion of purine derivatives in ruminants was largely unaffected by moderate changes in energy intake and by large changes in protein intake.
Tissue and whole-body oxygen uptake in fed and fasted steers
Authors: Eisemann J. H. , Nienaber J. A.
Published: September 2005

The effect of feeding v. fasting, on tissue blood flow, oxygen uptake and proportional contributions of the portal drained viscera (PDV), liver (Expts 1 and 2) and hindquarters (HQ; Expt 2) to whole-body O2 uptake were studied in beef steers. The combined techniques of indirect calorimetry and net tissue flux, the latter being the product of arterio-venous concentration difference and blood flow, were used in the experiments. In response to fasting, whole-body O2 consumption decreased as did O2 uptake by all measured tissues except the liver (trend only in Expt 1). Blood flow to all measured tissues decreased during fasting and fractional uptake of O2 decreased in PDV and increased in liver and HQ (Expt 2). Proportional contribution of specific tissues to whole-body O2 uptake changed when animals were switched from the fed to the fasted state. The percentage consumed by PDV decreased from 25.4 to 19.9, by liver increased from 20.5 to 26.4 and by HQ was unchanged (9.6 and 10.5) in Expt 2. These significant responses in Expt 2 were observed as trends in Expt 1. The changes in proportional contribution of tissues to whole-animal O2 uptake reflect the changing metabolic role of specific tissues to lack of food supply. These findings emphasize the central role of the liver in metabolism and indicate that fasting (catabolic) measurements may not reflect the previous fed (anabolic) physiological state.
Alcohol and its acute effects on resting metabolic rate and diet-induced thermogenesis
Authors: Weststrate Jan A. , Wunnink Ingrid , Deurenberg Paul , Hautvast Joseph G. A. J.
Published: September 2005

The impact of alcohol (ethanol) on resting energy expenditure of male non-obese volunteers was determined in two studies. In the first study the thermic effect of alcohol on resting metabolic rate (RMR) was assessed in ten male non-obese volunteers. In the second study the impact of alcohol on diet-induced thermogenesis (DIT) was determined in twelve male non-obese volunteers. Energy expenditure was measured with a ventilated-hood system. RMR was measured for 60 min with the subjects in a fasting state. In the first study subjects received in random order 20 g alcohol in concentrations of 75, 180 and 300 ml/I water respectively. After measurement of the RMR the thermic effect of alcohol was measured for 90 min. In the second study volunteers received in random order and in duplicate either a meal of food (2 MJ) plus an alcoholic aperitif (20 g alcohol in a 180 ml/1 solution) or an isoenergetic meal of food alone (2.55 MJ) plus a placebo aperitif containing no alcohol. DIT was measured for 240 min. Alcohol induced a significant thermic effect, which varied between 0.22 and 0.30 kJ/min. No systematic difference in DIT was observed among the different concentrations. DIT was not significantly affected by the ingestion of alcohol. Total DIT was 219 (SE 14) kJ for the alcohol treatment and 185 (SE 20) kJ for the control treatment. The results do not support the suggestion that alcohol is less efficiently used as an energy source in comparison with, for example, fats and carbohydrates.
Level of nutrition and visceral organ size and metabolic activity in sheep
Authors: Burrin D. G. , Ferrell C. L. , Britton R. A. , Bauer Marc
Published: September 2005

Thirty-two crossbred wether lambs (initial live-weight 31 kg) were fed on a diet (metabolizable energy (ME) 12.8 MJ/kg) ad lib. (ADLIB) or restricted to maintain body-weight (MAINT) for a 21 d period. On days 0, 7, 14 and 21, four lambs per treatment were slaughtered, visceral organs weighed and tissues sampled. During the 21 d period, ME intake in ADLIB lambs increased quadratically with an average rate of live-weight gain of 425 g/d. In MAINT lambs, live weight (30 kg) was maintained, and daily ME intake (kJ/kg empty body-weight (EBW)0.75) declined (P < 0.01) quadratically with time. Weights of liver, stomach and small intestines as a percentage of EBW were increased in ADLIB lambs and decreased by 10–33 % in MAINT lambs (treatment × day, P < 0.01). In vitro liver oxygen consumption was not affected by level of feed intake. Estimates of whole-liver O2 consumption (mmol O2/d per kg EBW) increased in ADLIB lambs and were relatively constant in MAINT lambs. These findings suggest that level of feed intake changes the relative proportion of visceral organs to body mass. In addition, the effect of level of feed intake on changes in the relative contribution of visceral organs to whole-body metabolic rate appears to be primarily a result of differences in organ size rather than tissue-specific metabolic activity.
Effects of maternal undernutrition and exercise on glucose kinetics in fetal sheep
Authors: Leury B. J. , Chandler K. D. , Bird A. R. , Bell A. W.
Published: September 2005

Fetal glucose kinetics were measured using a combination of isotope-dilution and Fick-principle methodology in single-pregnant ewes which were either well-fed throughout, or fed at 0.3–0.4 predicted energy requirement for 7–21 d during late pregnancy. All ewes were studied while standing at rest and then while walking on a treadmill at 0.7 m/s on a 10° slope for 60 min. Underfed ewes suffered major decreases in fetal total disposal rate, fetal-placental transfer and umbilical net uptake of glucose, each of which were significantly related to declines in maternal and fetal blood glucose concentrations respectively. In well-fed ewes, fetal endogenous glucose production was negligible, as indicated by the similarity between fetal utilization rate (total glucose disposal rate minus placental uptake of fetal glucose) and umbilical net uptake of glucose, and by nearly identical fetal and maternal arterial blood specific radioactivities of maternally infused D-[2-3H]glucose. By contrast, in underfed ewes, fetal utilization rate greatly exceeded umbilical net uptake of glucose, and the fetal:maternal [3H]glucose specific activity ratio declined significantly, suggesting induction of a substantial rate of fetal endogenous glucogenesis. Exercise caused increases in fetal total glucose disposal rate and glycaemia in fed and underfed ewes. In underfed ewes only, this was accompanied by increased placental uptake of fetal glucose and umbilical net glucose uptake, unchanged fetal glucose utilization and decreased fetal endogenous glucose production. It is concluded that fetal gluconeogenesis makes a major contribution to fetal glucose requirements in undernourished ewes. Increased maternal supply of fetal glucose during exercise substitutes for rather than adds to fetal endogenous glucogenesis.
Dietary animal proteins and cholesterol metabolism in rabbits
Authors: Lovati Maria R. , West Clive E. , Sirtori Cesare R. , Beynen Anton C.
Published: September 2005

The effect in rabbits of giving isonitrogenous purified diets containing casein, ovalbumin, fish protein, milk-whey protein and soya-bean protein were compared. The diets were balanced for cholesterol and for the amount and type of fat. When incorporated into low-cholesterol diets (0.8 g cholesterol/kg), casein, ovalbumin and soya-bean protein produced similar levels of serum cholesterol. With a high background of dietary cholesterol (1.5 g/kg), serum cholesterol concentrations increased with soya-bean protein, whey protein, casein and fish protein, in that order. Thus, the hypercholesterolaemic effect of casein in carefully balanced diets was only seen against a high-cholesterol background. The development of hypercholesterolaemia produced by giving fish protein was different from that produced by casein. First, less cholesterol accumulated in the very-low-density-lipoprotein fractions and more in the lipoproteins of higher density with fish protein than with casein. Second, fish protein, unlike casein, did not increase liver cholesterol. Third, transfer of rabbits from a diet containing soya-bean protein to one containing casein resulted in an immediate marked depression in neutral steroid and bile acid excretion in faeces. However, when rabbits were fed on the diet with fish protein after the diet with soya-bean protein, there was no significant depression in neutral steroid output and the depression in bile acid output was delayed. The present study suggests that different animal proteins cause hypercholesterolaemia by different mechanisms.
The effect of acute feeding of carnitine, acetyl carnitine and propionyl carnitine on basal and A23187-stimulated eicosanoid release from rat carrageenan-elicited peritoneal macrophages
Authors: Elliott G. R. , Lauwen A. P. M. , Bonta I. L.
Published: September 2005

Little is known about the ability of carnitine to modulate cell functions. As carnitine plays an important role in lipid metabolism we investigated the acute effect of L-carnitine, L-acetyl carnitine and L-propionyl carnitine (300 mg/kg per d; 4 d) on the basal and calcium-ionophore (A23187)-stimulated release of arachidonic acid metabolites from rat carrageenan-elicited peritoneal macrophages. A decrease in the number of peritoneal carrageenan-elicited macrophages was observed after feeding all three compounds. The basal release of prostaglandin E2, 6 keto-prostaglandin F1αand leukotriene B4was stimulated by all treatments. In contrast, thromboxane B2production was diminished by feeding carnitine and acetyl carnitine. A23187-stimulated synthesis of 6 keto-prostaglandin F1αand leukotriene B4was further enhanced by all three compounds. Acetyl carnitine and propionyl carnitine also enhanced thromboxane B2synthesis. However, no effects on prostaglandin E2formation were detected. The 6 keto-prostaglandin F1α: thromboxane B2ratio, calculated from the basal and A23187-stimulated values, was increased by carnitine treatment. In the presence of A23187 there was also an increase in the 6 keto-prostaglandin F1α: leukotriene B4ratio. We conclude that carnitine, and possibly some of its derivatives, could modify the macrophage component of an inflammation in vivo.
Protein and energy relations in the broiler chicken
Authors: Rosebrough R. W. , Mitchell A. D. , Vleck M. F. Von , Steele N. C.
Published: September 2005

Chickens were fed on diets containing either 12.8 MJ, 150 g crude protein (nitrogen x 6.25)/kg or 12.8 MJ, 200 g crude protein/kg to determine differences in metabolism. The diet containing 12.8 MJ, 150 g crude protein/kg contained either 8 or 12 g lysine/kg. Treatment variables examined in vitro were lipogenesis, glucose production and hepatic enzyme activities to compare metabolism in chicks fed on a low-protein, lysine-supplemented diet and a diet formulated to contain the required amount of lysine from intact protein. Growth was similar in chicks fed on diets containing either 12.8 MJ, 154 g crude protein with 12 g lysine/kg or 12.8 MJ, 200 g crude protein/kg. Net glucose production was greater (p< 0.05) in liver explants from chickens fed on diets containing either 12.8 MJ, 154 g crude protein with 12 g lysine/kg or 12.8 MJ, 200 g crude protein/kg than in explants from chickens fed on 12.8 MJ, 150 g crude protein with 8 g lysine/kg. Pyruvate use for glucose production was greater (p< 0.05) in chickens fed on a diet containing 12.8 MJ, 150 g crude protein with 8 g lysine/kg. The findings from the present study suggest that crystalline and ‘natural’ lysine additions to chick diets may influence metabolism differently.
Iron absorption from typical West African meals containing contaminating Fe
Authors: Galan Pilar , Cherouvrier Françoise , Zohoun Isidore , Zohoun Théophile , Chauliac Michel , Hercberg Serge
Published: September 2005

Iron absorption from three typical West African meals was measured in fourteen subjects using the extrinsic-tag technique with59Fe and55Fe. All meals consisted of maize as the staple food. Meals were prepared in Benin under realistic conditions from locally grown foods. Of the non-haem-Fe in the meals 39–73% did not exchange with the added inorganic radio-Fe tracer, depending on the degree of Fe contamination of meals. Non-haem-Fe absorption was low in each maize meal, but was even lower for those eaten with a vegetable sauce than for those eaten with a fish sauce. When haem-Fe absorption was included, 70.0–160μg Fe was absorbed. Expressed on an energy basis, the bioavailable nutrient density was 3.2–7.0 μ/100 kJ (13.4–29.5 μ/100 kcal). These findings suggest that total Fe available in the typical diets of West African countries does not meet the physiological requirements of large proportions of the population.
Effect of caffeine on zinc absorption and Zn concentration in rat tissue
Authors: Rossowska Magdalena J. , Nakamoto Tetsuo
Published: September 2005

The purposes of the present study were to determine whether caffeine has an effect on zinc absorption and tissue levels of Zn. Under anaesthesia, one side of the intestine of female rats was connected to infusion pumps and an infused solution (first caffeine and later Zn solution) was collected from the other side of the intestine using either 300 mm or the whole small intestine to determine Zn absorption. In a further study, different doses of caffeine solution were injected directly into the femoral vein and a saline or Zn solution was infused into the intestine to measure Zn absorption and tissue Zn concentrations. The results consistently showed that the caffeine solution infused into the intestine did not affect intestinal Zn absorption nor was absorption affected by the direct injection of caffeine into the vein. In contrast, injection of different doses of the caffeine solution significantly decreased Zn tissue levels for the heart only. Calcium concentrations in the heart tissue were also decreased, but not magnesium concentrations. Tissue Zn levels recovered immediately on infusion of a Zn solution into the intestine.
Large bowel fermentation in rats given diets containing raw peas (Pisum sativum)
Authors: Goodlad J. S. , Mathers J. C.
Published: September 2005

The digestion of non-starch polysaccharides (NSP) was studied in rats given semi-purified diets containing 0-500 g raw peas (Pisum sativum)/kg. NSP were equally well digested at all inclusion levels with digestibilities for individual constituents ranging from 0.58 for xylans to 0.99 for arabinose-containing polymers with a total NSP digestibility of 0.79. Increasing the dietary pea inclusion rate increased the amount of substrate flowing to the large bowel (LB) and this was associated with marked increases in caecal tissue and contents masses, a reduction in caecal transit time from 0.88 to 0.43 d and a threefold increase in faecal bacterial biomass output. Caecal pH fell as did the molar proportions of acetate, isobutyrate, isovalerate and valerate whilst butyrate increased when peas were included in the diet. Possible mechanisms for these fermentation end-product changes are discussed. Pea inclusion in the diet was associated with increased volatile fatty acid and 3-hydroxy butyrate concentrations in portal and heart blood. It was concluded that peas are a rich source of fermentable polysaccharides which produce a LB fermentation pattern of potential health benefit.
Influence of mild cold on 24 h energy expenditure in ‘normally’ clothed adults
Authors: Warwick P. M. , Busby R.
Published: September 2005

Ten subjects aged 19–35 years (four men and six women) underwent two measurements of 24 h energy expenditure (EE) in a whole-body respiration calorimeter, one at a temperature of 28° and one at 20°. Choice of clothing was allowed. Dietary intake was standardized and subjects were asked to follow the same pattern of activity during both measurements. Mean 24 h EE was significantly greater at the cooler temperature by 5.0 (SD 5.5) %, with individual differences ranging from 4.6% lower to 12.6% higher. The difference in EE at the two temperatures was similar during the day and the night and occurred even though subjects wore more clothes and used more bedding at 20°. No relationship was observed between response to 20° and body-weight status. In conclusion, the assumption that mild cold is unlikely to affect EE in subjects wearing normal clothing may be incorrect.
Correlation between the urinary excretion of acid-soluble peptides, fractional synthesis rate of whole body proteins, and plasma immunoreactive insulin-like growth factor-l/somatomedin C concentration in the rat
Authors: Nam Taek Jeong , Noguchi Tadashi , Funabiki Ryuhei , Kato Hisanori , Miura Yutaka , Naito Hiroshi
Published: September 2005

The relations between the urinary excretion of acid-soluble peptide (ASP)-form amino acids, the rate of whole body protein synthesis and plasma immunoreactive insulin-like growth factor-1/somatomedin C concentration were investigated in rats. The urinary ASP-form leucine plus valine excretion correlated well with the rate of whole body protein synthesis and with the plasma immunoreactive insulin-like growth factor-1 concentration. The results provide further evidence for the hypothesis that urinary excretion of ASP is an excellent index of the status of protein metabolism in animals.
Effects of bovine pituitary growth hormone alone or in combination with the β-agonist clenbuterol on muscle growth and composition in veal calves
Authors: Maltin C. A. , Delday M. I. , Hay S. M. , Innes G. M. , Williams P. E. V.
Published: September 2005

Twenty-three British Friesian bull calves at approximately 7 d of age were allocated to one of four treatments: controls untreated (five calves), a group (Clen) given 1 mg clenbuterol/kg diet (five calves), a group (GH) given a daily subcutaneous injection of 3.5 mg bovine pituitary growth hormone (GH) (five calves) and a group (Clen + GH) given a combination of clenbuterol as in the Clen group with GH as in the GH group (seven calves). All calves were given milk-substitute at levels adjusted weekly according to metabolic live weight. The animals were slaughtered over the weight range 150–170 kg. Samples of semimembranosus and triceps muscles were excised a t slaughter. Treatment with GH produced approximately a threefold increase in mean daily serum GH concentration. Calves given Clen + GH were heaviest a t slaughter and the combined treatment produced a significantly higher (P< 0-01) feed conversion ratio. Administration of clenbuterol either alone or in combination with GH increased the cross-sectional area of both fast twitch glycolytic (FG), and fast twitch oxidative glycolytic (FOG) fibres in both muscles. In contrast GH produced little change in fibre size in semimembranosus muscle, although FOG fibres in triceps were slightly larger than in controls. Neither Clen nor GH resulted in any change in fibre percentage frequency in either muscle. Treatments involving clenbuterol produced a significant decrease in muscle glycogen concentration. Muscles from all three treatment groups tended to show small increases in protein and RNA concentration compared with the controls. Muscles from animals treated with GH alone exhibited an increase in DNA concentration not seen in muscles from the two other treatment groups. Overall, the differential response to the two agents suggested that clenbuterol does not mediate its effects via the GH axis, and that an additive response in terms of protein anabolism may be achieved from the use of a combination of clenbuterol plus GH.
The effect of daily consumption of coconut fat and soya-bean fat on plasma lipids and lipoproteins of young normolipidaemic men
Authors: Mendis Shanthi , Kumarasundaram Ravi
Published: September 2005

The present paper reports the influence on plasma lipids of isoenergetic diets containing 30 YO of energy as fat, with a polyunsaturated: saturated fat ratio of 4.00 or 0.25, consumed for 8 weeks by twenty-five young normolipidaemic males. Approximately 70 % of the fat energy was provided by the test fats: soya-bean fat and coconut fat. During the soya-bean-fat-eating period the total plasma cholesterol level fell significantly compared with baseline values (P< 0.001) and during the coconut-fat-eating phase total plasma cholesterol level increased significantly compared with the soya-bean-eating period (P< 0001).On the soya-bean-fat diet, high-density-lipoprotein (HDL)-cholesterol decreased by 15 YO (range 6–35 YO) and plasma triacylglycerols decreased by 25 YO (range 13–37 YO). Results of the present study show that even when the proportion of total fat in the diet is low, a high intake of linoleic acid lowers both total plasma cholesterol and HDL-cholesterol, while a high intake of saturated fat elevates both these lipid fractions. Application of regression formulas to the present findings indicates that short-chain saturated fatty acids have a neutral effect on serum cholesterol
Dietary modification of potential vitamin K supply from enteric bacterial menaquinones in rats
Authors: Mathers J. C. , Fernandez Fresia , Hill M. J. , McCarthy P. T. , Shearer M. J. , Oxley A.
Published: September 2005

Rats given a low-fibre diet based on boiled white rice developed symptoms of severe vitamin K deficiency within 23 d. Inclusion of autoclaved black-eye beans (Vigna unguiculata) in the diet prevented the bleeding syndrome. To test the hypothesis that deficiency resulted from low phylloquinone intake exacerbated by inadequate production of menaquinones by the enteric bacteria, a follow-up experiment was carried out in which groups of rats were given an all-rice diet, a rice+beans diet or a stock diet. Rats on the allrice diet had significantly lower faecal concentrations of the main menaquinone-producing bacterial species (Bacteroides fragilisandBacteroides vulgutus) than animals on either of the other two diets. This coupled with the much lower faecal output on this diet suggests that total menaquinone production was low for the all-rice diet. The alterations in faecal flora were associated with several significant changes in caecal metabolism. Rats given the stock diet had much shorter caecal transit times and a considerably greater proportion of butyric acid in volatile fatty acid end-products than did rats on either of the other two diets.
Dietary fat modifies some metabolic actions of human recombinant tumour necrosis factor α in rats
Authors: Bibby D. C. , Grimble R. F.
Published: September 2005

To examine how fat might influence the metabolic effects of tumour necrosis factor α (TNFα), human recombinant TNFα was given intravenously to rats that had been fed for 12 weeks on diets containing (g/kg) 200 maize oil or 190 coconut oil+10 maize oil. Rectal temperature and tissue composition measurements were made 8 and 24 h after injection. Ambient temperatures of 20° and 25° were employed to accentuate rectal temperature changes. Doses of 30 and 300 μg TNFα/kg body-weight were given, and brought about depression of serum zinc and albumin and elevation of copper. Muscle protein content was decreased and liver protein and Zn content enhanced by TNFα. Serum Zn and liver Zn content were negatively correlated 8 h after injections. Hypothermia developed within 1 h of injection. All responses except the rise in serum Cu and gain in liver Zn were more intense at the higher than at the lower dose of TNFα. Hypothermia was exacerbated by an environmental temperature of 20°. The coconut-oil diet blunted the hypothermia and likewise the changes in serum albumin and Cu content 8 h after injections and in muscle and liver protein after 24 h. Changes in eicosanoid metabolism may be involved in the modulatory effects of the coconut-oil-enriched diet.
Rumen fill and digesta kinetics in lactating Friesian cows given two levels of concentrates with two types of grass silage ad lib
Authors: Gasa J. , Holtenius K. , Sutton J. D. , Dhanoa M. S. , Napper D. J.
Published: September 2005

Four lactating Friesian cows with permanent cannulas in the rumen and proximal duodenum were given early (EC)- or late (LC)-cut grass silage ad lib., each with either 3 or 9 kg concentrate dry matter (DM)/d in a 4 x 4 Latin square design starting about 10 weeks after calving. Feed was offered twice daily at 08.30 hours and 15.30 hours. Periods lasted 5 weeks and measurements were made in the last 15 d. The higher amount of concentrates increased total DM intake but reduced silage DM intake and the fractional rate of degradation of silage-fibre DM. Later cutting date of silage had no effect on DM intake or the fractional rate of degradation of silage-fibre DM but reduced potential degradability of silage fibre. Dilution rate of CoEDTA in rumen fluid was greater during the day (eating period) than during the night (resting period). Dilution rates measured at the duodenum were lower than those measured in the rumen, but neither was affected by diet. Silage-particle passage rates were measured by use of ytterbium-labelled silage fibre (Yb-fibre) and chromium-mordanted faecal particles (Cr-faeces) and samples were taken at the duodenum and in the faeces. Values for slower rate constant (k1) and transit time were higher and for faster rate constant (k2) were lower for Yb-fibre than for Cr-faeces, but differences in total mean retention time were inconsistent. Values for k1 for both markers and k2 for Yb-fibre only were similar at both sampling sites, but values for k2 for Cr-faeces were lower in the faeces. No diet effects were established with Yb-fibre but, with Cr-faeces, k1 was reduced by more concentrates and EC-silage. Daily mean weights of wet digesta, liquid, neutral-detergent fibre (NDF) and indigestible NDF in the rumen were greater with LC-silage but were unaffected by the amount of concentrates whereas weight of rumen DM was increased by the amount of concentrates only. Maximum rumen fill occurred at 18.00 hours with all diets. Particle-size distribution of rumen contents did not vary markedly during the day. Mean particle size was generally greater with LC-silage than EC-silage. Very small particles, passing through the 0.3 mm screen, constituted about half the rumen DM. It is concluded that rumen fill could have limited intake of LC-silage but not EC-silage. The reduced silage intake with greater concentrate intake was associated with a reduction in fibre degradation rate and an increase in rumen DM fill but no other consistent effects on weight or kinetics of rumen fractions were established.
Intestinal absorption of linoleic acid in experimental renal failure
Authors: Pahl M. V. , Barbari A. , Vaziri N. D. , Hollander D. , Yazdani M. , Tran J. , Kan R.
Published: September 2005

Linoleic acid (LA) transport in rats with experimental short-term and long-term renal failure (RF) was compared with that of sham-operated normal animals on liberal food intake and pair-fed animals. The perfusions in vivo and incubations in vitro were conducted using a micellar solution containing a wide range of LA concentrations. Both absorption in vivo and uptake in vitro of LA were significantly reduced in animals with short-term RF. Lipid extraction and separation by thin-layer chromatography revealed a marked LA trapping as trilinolein (TL) in the perfused intestinal tissue in the short-term RF group. The esterification process, as defined by the rate of LA incorporation into TL, was moderately reduced in short-term RF animals. The thickness of the unstirred water layer showed no significant difference among the groups studied. In contrast, animals with long-term RF exhibited normal absorption of LA in vivo at all concentrations tested. In conclusion, LA absorption is reduced in short-term RF and restored in long-term RF. Several steps including LA transport into and TL transport out of the enterocyte and the esterification process were impaired in short-term RF. These changes are not due to alteration in the unstirred water layer, anorexia, weight loss or a rapid effect of uraemic chemical environment or circulatory factors.
Effects of magnesium and zinc deficiencies on growth and protein synthesis in skeletal muscle and the heart
Authors: Dørup Inge , Clausen Torben
Published: September 2005

The effects of magnesium or zinc deficiency on growth, tissue contents of Mg or Zn and protein synthesis have been compared in 4–13-week-old rats. When maintained on Mg-deficient fodder (1.6 mmol/kg) or Zn-deficient fodder (27 μmol/kg) rats showed a reduced weight gain, whereas repletion caused increased growth rates. Pair-feeding experiments showed that this could not be attributed to reduced energy intake only. In rats maintained on Mg-deficient fodder for 14 d [3H]leucine incorporation into skeletal muscle and the heart was reduced by 24–38% compared with pair-fed controls (P <0.001–0.002). The incorporation of [3H]phenylalanine was reduced by 19–31%. Tissue Mg contents, however, were only reduced by 6–7% (not significant). The pair-fed rats showed no reduction in the [3H]leucine incorporation compared with ad lib. fed animals. In rats maintained on Zn-deficient fodder for 15 d [3H]leucine incorporation into skeletal and heart muscle was reduced by 57–64% compared with pair-fed controls. The pair-fed rats showed no reduction in the [3H]leucine incorporation compared with ad lib. fed animals. In the Zn-deficient animals the content of Zn was not reduced in the skeletal muscles, whereas there was a small (15%) but significant loss of Zn in the heart. In another experiment, Zn depletion for 17 d caused a reduction in [3H]leucine incorporation of 35–41 %. After 5 d of Zn repletion this defect was restored, and the [3H]leucine incorporation was above control level in the skeletal muscles. It is concluded that the intact organism is very sensitive to dietary Mg or Zn deficiency, and that the reduced growth and protein synthesis cannot easily be attributed to the reduction of tissue Mg or Zn content per se. This points to the existence of other control mechanisms mediating down-regulation of growth and protein synthesis in response to reduced dietary supplies and the ensuing drop in the plasma concentrations of Mg and Zn.
Vitamin C and the common cold
Authors: Hemilä Harri
Published: September 2005

The effect of vitamin C on the common cold has been the subject of several studies. These studies do not support a considerable decrease in the incidence of the common cold with supplemental vitamin C. However, vitamin C has consistently decreased the duration of cold episodes and the severity of symptoms. The benefits that have been observed in different studies show a large variation and, therefore, the clinical significance may not be clearly inferred from them. The biochemical explanation for the benefits may be based on the antioxidant property of vitamin C. In an infection, phagocytic leucocytes become activated and they produce oxidizing compounds which are released from the cell. By reacting with these oxidants, vitamin C may decrease the inflammatory effects caused by them. Scurvy, which is caused by a deficiency in vitamin C, is mostly attributed to the decreased synthesis of collagen. However, vitamin C also participates in several other reactions, such as the destruction of oxidizing substances. The common cold studies indicate that the amounts of vitamin C which safely protect from scurvy may still be too low to provide an efficient rate for other reactions, possibly antioxidant in nature, in infected people.
The inhibition of nutrient digestion by wheat pentosans
Authors: Choct M. , Annison G.
Published: September 2005

Two pentosan-rich fractions (water-extractable, WEP, and alkali-extractable, AEP) were isolated from a wheat milling by-product. When both WEP and AEP were added to a commercial-type broiler diet the apparent metabolizable energy (AME), nitrogen retention, feed utilization and growth of broilers were significantly (P < 0.001) depressed. These depressions were closely correlated (P < 0.001) to the level of pentosans in the diets. At the highest level of inclusion of pentosans (equivalent to 40 g arabinoxylans as AEP/kg) the ileal digestibilities of starch, protein and lipid were decreased by 14.6, 18.7 and 25.8% respectively.

Anti-nutritive effects: Non-starch polysaccharides: Broiler diets
Effect of dietary protein and energy intakes on whole-body protein turnover and its contribution to heat production in chicks
Authors: Kita K. , Muramatsu T. , Okumura J.
Published: September 2005

A factorial 3 × 3 experiment was conducted with chicks to investigate the effect of manipulating crude protein (N × 6.25) intake (CPI) and metabolizable energyintake (MEI) simultaneously, in the range low to high (including adequate) levels with regard to the respective requirements, on whole-body protein turnover and its contribution to total heat production. The fractional rate of whole-body protein synthesis was increased curvilinearly by increasing MEI or CPI from low to high levels. In terms of absolute rates whole-body protein synthesis was enhanced by increasing MEI from low to adequate levels, the effect being greater at adequate and high CPI than at low CPI. The effect of varying CPI and MEI on whole-body protein degradation was similar, but less sensitive, to that on whole-body protein synthesis. Increasing MEI from low to high levels elevated totalheat production at all CPI levels. There were no interactive effects of varying CPI andMEI on the contribution of whole-body protein synthesis to total heat production, and in general the contribution increased with increasing CPI and decreased with increasing MEI.The contribution of whole-body protein synthesis to total heat production fell within a small range from 11.2 to 16.5%.
Responses in the voluntary intake of hay or silage by lactating cows to intraruminal infusions of sodium acetate or sodium propionate, the tonicity of rumen fluid or rumen distension
Authors: Anil M. H. , Mbanya J. N. , Symonds H. W. , Forbes J. M.
Published: September 2005

Rumen-fistulated lactating cows were individually fed on hay or silage and intakes were monitored during 3 h treatment periods and for 2 h after. Each experiment used five, six or seven animals and the treatments were applied in a Latin Square design. Sodium acetate infusions of 1·8–11·0 mol in 4.5 litres water caused a dose-related depression in hay intake, the extent being 82 g dry matter (DM)/mol infused (P < 0·01). Sodium acetate infusions of 6·0–15·0 mol in 4·5 litres water caused a dose-related depression in silage intake of 118 g DM/mol infused. Rumen fluid pH for both diets was unaffected by treatment. Acetate and Na concentrations were increased and significantly negatively correlated with intake of both diets. Infusions of 2–8 mol sodium propionate caused a dose-related depression of hay intake which was significant when cow and day effects were accounted for. Sodium propionate infusions of 4–8 mol significantly depressed silage intake by 140 g DM/mol infused (P < 0·001). Rumen fluid pH was unaffected by treatment while propionate and Na concentrations were elevated and significantly negatively correlated with intake for both diets. Inflation of a rubber balloon in the rumen with 12.5–20 litres warm water resulted in a dose-dependent depression in hay intake of 66 g DM/1 distension (P < 0·05). There was significant overeating during the 2 h following the 20 litre treatment. With silage, 15–25 litres of balloon distension for 3 h resulted in a dose-dependent depression in intake of 28 g DM/l distension (P < 0·001). There was no significant overeating during the 2 h following distension. When given in physiological amounts, at the lower end of the range used in these experiments, acetate, propionate and distension of the rumen did not significantly affect hay intakes. However, in each case the linear relationship between intake depression and level of treatment suggested that these factors could contribute to the control of feed intake.
The voluntary intake of hay and silage by lactating cows in response to ruminal infusion of acetate or propionate, or both, with or without distension of the rumen by a balloon
Authors: Mbanya J. N. , Anil M. H. , Forbes J. M.
Published: September 2005

In order to test the hypothesis that negative leedback signals from abdominal receptors are integrated in an additive manner in the control of voluntary food intake, cows with rumen fistulas were given intraruminal infusions of sodium acetate or sodium propionate, cr both, with or without distension of the rumen by balloon. Intakes were monitored during the 3 h experimental period and for 2 h after and samples of rumen fluid were taken for estimation of short-chain fatty acid concentrations and osmolality. Six cows in mid-lactation were fed on hay and concentrates and given, into the rumen. 5.5 mol sodium acetate, 5.2 mol sodium propionate and 7.51 of distension. Compared with the control (water infusion), neither acetate, propionate nor distension significantly depressed hay intake when given separately. When given in combination, however, the following significantly depressed intake during the 3 h treatment period: propionate + distension, acetate + distension, acetate + propionate + distension. Seven cows in early lactation were fed on silage and concentrates and given, into the rumen, 9.0 mol sodium acetate, 4.0 mol sodium propionate and 10.0 litres of distension. Again, none of the three given alone depressed silage intake to a significant extent during the 3 h treatment period, whereas the following combinations had a significant effect: propionate + distension, acetate + distension, acetate + propionate + distension. Basal rumen osmolalities were similar for the two types of feed but infusion of the sodium salts caused a very much greater increase with silage than with hay. The results are discussed with regard to the implications for our understanding of the control of voluntary intake and the likely role of chemo-, osmo- and mechano-receptors.
Influence of dietary fish proteins on plasma and liver cholesterol concentrations in rats
Authors: Zhang Xizhong , Beynen Anton C.
Published: September 2005

The effects of amount and type of dietary fish proteins on plasma and liver cholesterol concentrations were evaluated in female rats. The isonitrogenous diets used contained 10 g cholesterol/kg and were carefully balanced for residual fat, cholesterol, Ca, Mg and P in the protein preparations. Cod meal, soya-bean protein or casein was incorporated into the diets as the only source of dietary protein a t three levels: either 24,48 or 72 g N/kg diet. Extra protein was added to the diet at the expense of the glucose component. In a second experiment soya-bean protein, casein, cod meal, whiting meal or plaice meal was added to the diet at a level of 24 g N/kg. When compared with casein, cod meal and soya-bean protein decreased plasma and liver cholesterol concentrations. A further cholesterol-lowering effect was achieved by increasing the proportion of either soya-bean protein or cod meal in the diet. Substitution of casein for glucose did not influence plasma and liver cholesterol concentrations. Plaice meal in the diet produced lower group mean plasma cholesterol concentrations than did whiting meal. In rats fed on the diet containing plaice meal, liver cholesterol concentrations were significantly lower than those in their counterparts fed on either cod meal or whiting meal. The present study demonstrates that different fish proteins in the diet have different effects on cholesterol metabolism and that the cholesterol-influencing properties of cod meal can be enhanced by the incorporation of higher proportions of this protein in the diet.
Biochemical responses of broiler chicks to folate deficiency
Authors: Rennie J. Sarah , Whitehead Colin C. , Armstrong John
Published: September 2005

The effects of folate sufficiency and deficiency in three pathways of folate metabolism were studied in 2- and 3-week-old broiler chicks. Erythrocyte phosphoribosylpyrophosphate concentrations and dihydro- folate reductase (EC 1.5.1.3) activity were significantly elevated in folate deficiency. Percentage incorporation of deoxyuridine into bone marrow DNA was reduced in folate deficiency. There was a trend towards reduced liver dihydrofolate reductase activity in deficient chicks. These studies identify further biochemical criteria that can be used to assess folate status of chicks.
Vitamin A absorption in children with ascariasis
Authors: Ahmed F. , Mohiduzzaman M. , Jackson A. A.
Published: September 2005

The effect of Ascaris lumbricoides infection on retinol absorption was investigated in young children from a slum area of Dhaka City, Bangladesh. Twenty-four children aged 4–10 years were screened and in every case eggs of either Ascaris, Trichuris or hookworm were isolated from the stool. The average serum retinol was 0.91 (sd 0.35) μmol/l and sixteen children had levels below 1.05 μmol/l. This compared with a serum retinol concentration of 1.70 (sd 0.52) μmol/l in five reference children from a more privileged social background. An oral dose of retinol (41.8 μmol) was given, to ten children in whom the concentration of Ascaris eggs in the stool varied. Less than 1% of the supplement could be recovered in the stools collected over the following 48 h. Ascaris worms were isolated from the stool and assayed for retinol content. In no case was retinol detected in the worms. These findings do not support the contention that infection with Ascaris predisposes to malabsorption of vitamin A.
A continuous in vitro method for estimation of the bioavailability of minerals and trace elements in foods: application to breads varying in phytic acid content
Authors: Wolters Mechteldis G. E. , Schreuder Hendrika A. W. , Van Den Heuvel Grietje , Van Lonkhuijsen Henk J. , Hermus Ruud J. J. , Voragen Alfons G. J.
Published: September 2005

A continuous in vitro method for the estimation of the bioavailability of minerals and trace elements is presented. This in vitro method is believed to be more representative of in vivo physiological conditions than in vitro methods based on equilibrium dialysis, because dialysable components are continuously removed from the pancreatic digestion mixture. The continuous in vitro method is compared with the equilibrium in vitro method with respect to the dialysability of Ca, Mg, Fe, Cu and Zn from eight different types of bread (varying in phytic acid content). The results show a pronounced effect of continuous removal of dialysable components from the pancreatic digestion mixture on the dialysability of minerals and trace elements. Furthermore, removal of dialysable components influences the effect of phytic acid on the bioavailability of minerals and trace elements. For these two reasons the importance of removal of dialysable components in vitro for the estimation of bioavailahility in vivo needs further investigation. The bioavailability of minerals and trace elements from bread samples is not related to the phytic acid content only. Therefore, the effect of phytic acid on the bioavailability of minerals and trace elements cannot be studied separately from the effects of other components on bioavailability.