bluuebunny/crossref_metadata_2025 huggingface dataset:
Faecal dry weight and potassium are related to faecal sodium and plasma aldosterone in rats chronically fed on varying amounts of sodium or potassium chlorides
Authors: McCabe Richard D. , Smith Manis J. , Dwyer Terry M.
Published: June 2005

Recent studies have shown that faecal residue (dry weight) and Na and K increase with increasing levels of dietary fibre, an effect which may be related to unstirred layers that slow absorption and the flow rate of chyme through the gastrointestinal tract. Salts of Na are the primary osmotic components of chyme and influence both retention of fluid in the bowel and transit of fluid from the small to the large intestine. The present study examines the chronic effects of dietary Na and K intake on faecal Na, K and residue excretion. Male Sprague-Dawley rate were given 12–13 g feed/d (control (g/kg): Na 4, K 8.5) for 1 week, followed by a 4-week period where Na or K intake was altered (0.01–3 times control levels). These diets altered chronic (> 1 week) faecal residue excretion and affected Na and K excretion by 8-, 310-and 2100-fold respectively. Low dietary Na reduced faecal Na and residue; K excretion was doubled during week 1, but fell over weeks 2–4 despite a 4–5-fold increase in plasma aldosterone. Chronic high dietary Na increased faecal Na, residue and K despite a 60% decrease in plasma aldosterone. Chronic low dietary K decreased faecal Na, K and residue and plasma aldosterone. Chronic high dietary K did not alter faecal Na and K despite increased faecal residue and a 4–5-fold increase in plasma aldosterone. Faecal water was unchanged by diet, paralleling changes in faecal residue. Analyses of the results provide systematic models of chronic regulation of faecal Na, K and residue excretions. When plasma aldosterone is low (< 160 ng/I), weekly faecal residue excretion is equal to 3.6 g (fibre intake was 2.6–2.7 g/week) + 2.6 g/mmol Na, and K excretion is equal to 0.55 mmol/mmol Na. When plasma aldosterone is high (> 1500 ng/I) weekly faecal residue excretion is equal to 2.3 g + 2.6 g/mmol Na, and K excretion is equal to 0.7 mmol/week + 0.55 mmol/mmol Na.
Effect of dietary protein source on feed intake, growth, pancreatic enzyme activities and jejunal morphology in newly-weaned piglets
Authors: Makkink Caroline A. , Negulescu George Puia , Guixin Qin , Verstegen Martin W. A.
Published: June 2005

Seventy piglets with no access to creep feed were weaned at 28 d of age and fed on one of four diets based on either skimmed-milk powder (SMP), soya-bean-protein concentrate (SPC), soya-bean meal (SBM) or fish meal (FM). At 0, 3, 6 and 10 d after weaning, piglets were killed and the pancreas and digesta from stomach and small intestine were collected, freeze-dried and analysed for dry matter (DM), N, and trypsin (EC3.4.21.4) and chymotrypsin (EC3.4.21.1) activities. Small-intestinal tissue samples were taken to examine gut wall morphology. Results indicated that dietary protein source affected post-weaning feed intake, pancreatic weight, gastric pH and gastric protein breakdown, and pancreatic and jejunal trypsin and chymotrypsin activities. Post-weaning feed intake appeared to be an important factor in digestive development of newly-weaned piglets.
The effects of experimental malnutrition on albumin metabolism and distribution in rabbits
Authors: Weidel S. E. , Smith G. , Fleck A.
Published: June 2005

In order to determine the extent to which the concentration of albumin in plasma is maintained at the expense of the extravascular pool during protein-energy malnutrition, the rates of exchange between albumin in plasma (1A) and the extravascular pool (EA) and consequently the distribution of albumin between intravascular and extravascular pools (expressed as EA:IA) were measured in protein-energy-depleted and control rabbits. The fractional rates of synthesis (FSR) and catabolism (FCR), the concentration of albumin and the plasma volume (PV) were also measured. In animals in which protein-energy intake was reduced by 58% the concentration of albumin in plasma remained unchanged, whereas FCR decreased by 38 % and FSR by 30 YO. No significant changes in EA: IA or PV were found. We conclude that albumin concentration during proteirrenergy depletion is not maintained at the expense of extravascular albumin, but by parallel changes in the rates of catabolism and synthesis.
β-Carotene-15,15′-dioxygenase (EC1.13.11.21) isolation reaction mechanism and an improved assay procedure
Authors: Devery Jannine , Milborrow B. V.
Published: June 2005

βCarotene-15,15′-dioxygenase (EC1.13.11.21; β-carotene dioxygenase) activity in extracts from guinea-pig intestinal mucosa was assayed by supplying [15,15′-14C2l- or [15,15′-3H2]β-carotene dissolved in Tween 80. Methods were developed to minimize the breakdown of labelled β-carotene and β-carotene cleavage products during the isolation procedure. Antioxidants and unlabelled carriers were added to extracting solvents and C18Sep-Pak cartridges were used to isolate the remaining β-carotene and retinaldehyde, which was the only cleavage product detected. The labelled material produced by the enzyme was analysed by either normal-phase TLC or reversed-phase HPLC and characterized chemically as retinaldehyde. The lack of other labelled up-carotenals isolated in these experiments and the formation of between 1.5 and 2 mol retinaldehyde/mol β-carotene consumed confirm the central cleavage mechanism for the enzyme's action. More β-carotene dioxygenase activity was obtained from guinea-pig mucosa than from chicken or pig intestinal mucosa. The β-carotene dioxygenase was obtained as a soluble enzyme which was partially purified by gel filtration and ion-exchange chromatography to a specific activity of 0.6 nmol retinaldehyde formedlmg protein per h. The formation of a lipid-protein aggregate containing the β-carotene dioxygenase activity, which has been reported to be present in the exclusion volume of Sephadex columns, was avoided if the mucosal serapings were homogenized in buffer at a proportion of 1:4 (w/v).
Iron-deficiency anaemia and physical performance in adolescent girls from different ethnic backgrounds
Authors: Nelson M. , Bakaliou F. , Trivedi A.
Published: June 2005

One hundred and fourteen 11–14-year-old schoolgirls from Wembley, Middlesex, were assessed for Fe status (haemoglobin (Hb), packed cell volume and mean corpuscular Hb concentration, height, weight eating habits, and ethnic origin, and undertook a step test to assess physical performance. Overall, 20% of girls had Hb less than 120 g/l, ranging from 11 % in White girls to 22–25% in girls of Asian origin. Prevalence of low Hb was 20% in vegetarians, higher in White vegetarians compared with non-vegetarians (23 v. 4%), but lower in the Indian vegetarians compared with non-vegetarians (17 v. 32%). Low Hb was present in 25 % of girls who had tried to lose weight in the previous year, and was more common in girls from manual social class backgrounds than non-manual (24 v. 10%). At the start of the step test the twenty-three girls with low Hb had heart rates similar to those with normal Hb, but hear rates in the low Hb group were significantly elevated immediately after the step test, and still significantly elevated 1 min later. The present results confirm the findings of a previous study in White girls, and suggest that physical performance may be compromised at mild levels of anaemia.
Iodine in British foods and diets
Authors: Lee Susan M. , Lewis Janet , Buss David H. , Holcombe Gillian D. , Lawrance Paul R.
Published: June 2005

Levels of I were determined in selected foods and dietary supplements, and in samples of the British ‘Total Diet’. The average concentration of I in British milk collected in thirteen areas on four occasions during 1990 and 1991 was 150 μg/kg (range 40–310 μg/kg), compared with 230 μg/kg in 1977–79. No difference was found between skimmed and whole milk. Winter milk contained 210 μg/kg while summer milk contained 90 μg/kg. Regional differences were less pronounced than seasonal differences. Levels in fish and fish products were between 110 and 3280 μg/kg. Edible seaweed contained I levels of between 4300 and 2660000 μg/kg. Kelp-based dietary supplements contained I at levels that would result in a median intake of 1000 μg if the manufacturers' recommended maximum daily dose of the supplement was taken, while other I-containing supplements contained a median level of 104 μg in the manufacturers' maximum recommended daily dose. Intake of I, as estimated from the Total Diet Study, was 173 μg/d in 1985 (277μgif samples with very high I contents were included) and 166 μg/d in 1991. These levels are above the UK reference nutrient intake of 140 μg/d for adults but well below the Joint Expert Committee on Food Additives provisional maximum tolerable intake of 1000 μg/d.
Ferrous sulphate does not directly affect pteroylmonoglutamic acid absorption in rats
Authors: Campbell Norman R. C. , Hasinoff Brian B. , Slngh Mukhtiar , Robertson Susan
Published: June 2005

A variety of compounds which bind to Fe have substantial reductions in absorption when co-administered with Fe compounds. The binding of both Fe2+ and Fe3+ ions to pteroylmonoglutamic acid and the pteroylmonoglutamate dianion was examined in vitro. In dimethylsulphoxide (DMSO) alone, pteroylmonoglutamate formed a 2:1 (pteroylmonoglutamate: Fe3+ ion) complex. However, in DMSO–aqueous Bis-Tris buffer (4:1, v/v; pH 6.0) no evidence of complex formation could be seen. Likewise spectroscopic evidence was obtained for complex formation with Fe2+ ion and pteroylmonoglutamate in DMSO alone but not in the aqueous DMSO buffer. In vivo studies examined the effect of FeSO4 on pteroylmonoglutamic acid absorption in an isolated perfused rat jejunal model of nutrient absorption. The dose of pteroylmonoglutamic acid approximated a human dose of 1 mg for the rat, while the FeSO4 doses were chosen to represent 6.4 mg, 64 mg and 300 mg human doses. There was no significant effect of FeSO4 on pteroylmonoglutamic acid absorption or instability of pteroylmonoglutamic acid in vivo in the presence of FeSO4 in the rat. Although 2:1 binding of pteroylmonoglutamic acid to Fe ions could be demonstrated in DMSO alone, no binding could be demonstrated in DMSO–Bis-Tris buffer (4:1, v/v; pH 6.0). It is unlikely that there will be a significant reduction in pteroylmonoglutamic acid absorption during concurrent ingestion of Fe preparations.
Degradation of glucosinolates during in vitro incubations of rapeseed meal with myrosinase (EC 3.2.3 1) and with pepsin (EC 3.4.23.l)–hydrochloric acid, and contents of porcine small intestine and caecum
Authors: Maskell Ian , Smithard Ron
Published: June 2005

Changes in the concentrations of glucosinolates from rapeseed meal and some glucosinolate degradation products during incubation in vitro with myrosinase (EC 3.2.3.1), with pepsin (EC 3.4.23.1)–HCI, and with contents of porcine small intestine and caecum were studied. When rapeseed meal was incubated with myrosinase, 5-vinyl oxazolidinethione (OZT) and butenyl and pentenyl isothiocyanates were produced; OZT concentration rose to a plateau after about 2 h. However, when incubated with caecal contents only OZT could be detected; its concentration peaked after about 4–5 h then declined. Under in vitro conditions whirh attempted to simulate peptic and small intestinal digestion no OZT could be detected; the individual glucosinolates differed in susceptibility to peptic conditions, losses ranging from 3 to 23%. Under the small intestinal conditions the losses of individual glucosinolates ranged from about 7 to 28%. Addition of CuSO4, ascorbic acid, tylosin or a probiotic had little effect on the outcome of peptic or small intestinal incubations but tylosin appeared tc slow the degradation of glucosinolates in the presence of caecal contents.
Assay and digestion of 14C-labelled condensed tannins in the gastrointestinal tract of sheep
Authors: Terrill T. H. , Waghorn G. C. , Woolley D. J. , Mcnabb W. C. , Barry T. N.
Published: June 2005

Three experiments were conducted to determine the fate of condensed tannins (CT) during digestion in sheep. CT were measured as extractable, protein-bound and fibre-bound fractions using the butanol-HCI procedure. In Expt 1, purified CT were added to digesta from different parts of the digestive tract obtained from a pasture-fed sheep. Recoveries of CT after 0 and 4 h of anaerobic incubation at 39° averaged: rumen 78.9 and 57.5 %; abomasum 50.9 and 49.0 %; duodenum 64.4 and 46.0 % and ileum 43.4 and 38.8%. In Expt 2, [14C]CT was given per abomasum over a 6.5 h period at 15 min intervals to a sheep previously fed on Lotus pedunculatus (which contains CT). The sheep was killed at the end of the period and 92.4% of the label was recovered. Virtually all of the label was in the digesta, and none was detected in the blood, so that the CT-carbon appeared not to be absorbed from the small intestine. In Expt 3, rumen, abomasal and ileal digesta and faeces samples from sheep fed on Lotus pedunculatus were analysed for CT and CT flow along the digestive tract calculated from reference to indigestible markers. Values were low in all digesta samples, indicating disappearance of CT across the rumen and small intestine, and CT recovery in faeces was only about 15% of intake. However, the 14C results from Expt 2 suggested that little if any CT-carbon was absorbed and the low recoveries in Expt 1 are considered to be a consequence of either conformational changes to the CT molecule such that it is no longer detectable by colorimetric methods, an inability of the analytical method to release bound CT for the butanol–HCI assay, or interference from other digesta constituents. It is concluded that the butanol–HCI method of CT analysis is appropriate for quantifying CT in herbages but not in digesta or faeces, and that a substantial part of CT released during protein digestion in the small intestine may not be detectable by normal CT analytical methods.
The significance of socio-economic characteristics for adult seasonal body-weight fluctuations: a study in north-western Benin
Authors: Van Liere Marti J. , Ategbo Eric-Alain D. , Hoorweg Jan , Den Hartog Adel P. , Hautvast Joseph G. A. J.
Published: June 2005

Large variations in seasonal body-weight fluctuations have been described for individuals from different households living and working under comparable circumstances. In the present study the relationship between socio-economic household characteristics and seasonal body-weight fluctuations of individual members of rural Beninese households were studied. No significant correlation was found for body-weight fluctuation between the two study years, nor for body-weight fluctuation of men and women belonging to the same household. When comparing dichotomized socio-economic classes for relative body-weight fluctuation of men and women in both study years, no consistent trends were observed for both years nor for both sexes. The distribution of subjects with a consistent high weight fluctuation over the two study years did not differ between socio-economic groups. In conclusion it may be stated that there were no indications that socio-economic characteristics play a determining role in the magnitude of body-weight fluctuation of this study population, despite the large variations observed in the latter. Therefore it is most likely that other factors decide the weight fluctuations of individuals, health and sanitation being the most likely candidates.
The use of intragastric nutrition to study saliva secretion and the relationship between rumen osmotic pressure and water transport
Authors: Zhao G. Y. , Durić M. , Macleod N. A. , ØRskov E. R. , Hovell F. D. Deb. , Feng Y. L.
Published: June 2005

Four sheep sustained by intragastric nutrition were used to study saliva secretion and the relationship between osmotic pressure in the rumen and net water transport across the rumen wall. Different concentrations of buffer were infused into the rumen to change the rumen osmotic pressure. Salivary secretion was estimated from entrance of P into the rumen. Net water transport across the rumen wall was calculated as the difference between water inflow and water outflow from the rumen. A negative linear relationship between the rumen osmotic pressure (X, mOsm/kg) and the water absorption across the rumen wall (Y, ml/h) was found: Y = (394 SE 8·3)–(l·22 SE 0·03) X, r20·83, (P < 0·001), and a positive linear relationship was found between the rumen osmotic pressure (X, mOsm /kg) and the outflow rate of rumen fluid (Y, ml/h): Y = (34·0 SE 8·0) + (0·97 SE 0·03), X, r2 0·56, (P < 0·001). The implication is that rumen osmotic pressure can be a key factor in the control of the net water transport across the rumen wall, the outflow of rumen fluid to omasum and the rumen liquid dilution rate. A method is suggested by which salivary secretion in sheep may be calculated from the water balance in the rumen.
The influence of dietary advice on nutrient intake during pregnancy
Authors: Anderson Annie S. , Campbell Doris M. , Shepherd Richard
Published: June 2005

To assess the effect of an antenatal nutrition programme designed specifically for the local population, questionnaires on nutrition knowledge, attitudes to healthier eating and 4 d diet diaries were completed by women attending routine antenatal clinics. Women who received the nutrition education programme were allocated into an Intervention Education Group whilst those women who did not were allocated into a Routine Education Group. The results showed that knowledge about nutrition was significantly higher in the intervention group. However, no significant differences were detected between the two groups for attitude variables or nutrient intake. It is concluded, therefore, that the most-widely-read form of nutrition advice for pregnant women may have some impact on nutrition knowledge but has little effect on nutrient intake during pregnancy.
Adaptation to high-fat diets: effects on eating behaviour and plasma cholecystokinin
Authors: French S. J. , Murray B. , Rumsey R. D. E. , Fadzlin R. , Read N. W.
Published: June 2005

Twelve male subjects took part in a study to investigate the effects of overfeeding a high-fat diet (19·17 MJ/d; 58% energy from fat) for 2 weeks on plasma cholecystokinin (CCK) levels, food intake, and subjective feelings of hunger and fullness. Before and after the diet, subjects completed a 2-week weighed dietary inventory, formal measurements of food intake from a pre-selected appetizing evening meal were carried out, and blood samples were taken after a standard breakfast for measurement of CCK. Hunger and fullness were rated on visual analogue scales before and after each of these meals and at evening meals during the diet period. Following the high-fat diet there was a small non-significant increase in food intake from the pre-selected meal (6919 (SE 615) kJ ν 6405 (SE 540) kJ; P = 0·1) and a significant increase in the average daily food consumption measured from the diaries (10·25 (SE 0·49) MJ/d ν. 9·59 (SE 0·62) MJ/d; P = 0·05). Corresponding trends of increasing feelings of hunger and declining fullness also occurred over the study period. Plasma CCK responses to the standard breakfast were raised following the diet (1285 (SE 153) ν. 897 (SE 78) pM min; 3h integrated CCK production post ν. pre diet; P < ·01) with the major differences observed at 90 and 120 min following the meal. These results suggest that the increase in food intake may be related to a down-regulation in putative CCK receptors responsible for food intake. Elevated CCK levels might suggest a corresponding down-regulation in CCK receptors responsible for feedback inhibition of CCK release.
Adaptation of energy metabolism to undernutrition in ewes. Contribution of portal-drained viscera, liver and hindquarters
Authors: Ortigues Isabelle , Durand D.
Published: June 2005

Adaptation of energy metabolism to undernutrition and to the duration of undernutrition was studied in adult, non-pregnant, non-lactating ewes at the whole-animal, portal-drained viscera, liver and hindquarters levels. Arterio-venous and indirect calorimetry techniques were used. Animals were successively fed at 1 times (3 weeks) and at 0.5 times (7 weeks) their metabolizable energy requirements for maintenance (MEm). Portal, hepatic and hindquarters blood flows in quietly standing ewes decreased by 22, 19 and 11% respectively within the first week of undernutrition and remained at that level thereafter. Standardizing hindquarters blood flow to that in a given posture (quietly standing) reduced blood flow by 9.8%. In the portal-drained viscera and liver, O2 extraction rates decreased, leading to 34 and 38% drops in O2 consumption with underfeeding respectively. In the hindquarters, O2 extraction rate increased, partly counterbalancing the drop in blood flow. Thus O2 consumption of hindquarters tended to decrease but the effect was not significant. All changes appeared to be completed from day 5 of underfeeding. Consequently, the portal-drained viscera, liver and carcass were responsible for 39, 32 and 5% respectively of the drop in whole-animal O2 consumption with underfeeding. At the end of the 0.5 X MEm period, in vivo metabolic rates averaged 1.65, 4.89 and 0.38 mmol O2 consumed/d per g fresh weight of adipose-tissue-free portal-drained viscera, liver and boneless hindquarters respectively. Undernutrition imposed a much greater nutritional challenge to splanchnic tissues than to hindquarters. The former reduced theirenergy expnditure whereas hindquarters metabolism adapted by counteracting the slight drop in nutrient supply.
Metabolism of ornithine, α-ketoglutarate and arginine in isolated perfused rat liver
Authors: De Bandt Jean Pascal , Cynober Luc , Lim Soo Kyung , Coudray-Lucas Colette , Poupon Raoul , Giboudeau Jacqueline
Published: June 2005

Ornithine (Orn; α-ketoglutarate (αKG) salt) and arginine (Arg) supplementation of enteral diets has been advocated in the treatment of hypercatabolism of trauma patients, but both compounds are subject to extensive hepatic metabolism. To compare the metabolism of these two compounds and to evaluate the possible influence of the αKG moiety, livers were perfused with αKG, Orn, ornithine α-ketoglutarate (OKG) or Arg (n6 in each group) for 1 h. Arg uptake was nearly fourfold higher than Orn uptake (690 (SD 162) ν. 178 (SD 30) nmol/min per g liver), and Orn uptake was not modified by αKG. Orn was totally metabolized by the liver, whereas Arg led to Orn release (408 (SD 159) nmol/min per g liver) and a threefold stimulation of urea production (Arg 1·44 (SD 0·22) ν. Orn 0·45 (SD 0.09) μol/min per g liver). αKG alone only increased hepatic aspartate uptake but, when associated with Orn as OKG, it led to an increase in giutamate release and in proiine content in the liver and to a decrease in proiine uptake. From these findings we conclude that (1) Arg load is extensively metabolized by the liver, inducing urea production, (2) in enteral use, Orn supplementation appears preferable to Arg as it is less ureogenic (as also recently demonstratedin vivoin stressed rats receiving isomolar amounts of Arg and Orn), (3) the liver participates in the Orn-αKG metabolic interaction, mostly in proiine metabolism, which occurs in the splanchnic area.
Effects of dietary propionate on hepatic glucose production, whole-body glucose utilization, carbohydrate and lipid metabolism in normal rats
Authors: Boillot Josette , Alamowitch Catherine , Berger Anne-Marie , Luo Jing , Bruzzo Françoise , Bornet Francis R. J. , Slama Gerard
Published: June 2005

Increased intake of dietary fibres is associated with several beneficial effects on carbohydrate and lipid metabolism. The colonic fermentation of dietary fibres produces short-chain fatty acids (SCFA; acetate, propionate and butyrate). Some authors have suggested that SCFA could be partly responsible for the effects of dietary fibres. The purpose of the present study was to test the effects of one of the SCFA, propionate. The effects of moderate amounts of dietary propionate on insulin sensitivity and hepatic glucose production were studied in male Sprague-Dawley rats. Two groups of twenty-one adult rats were fed for 3 weeks on a diet containing 78 g propionate/kg (P) or 78 g/kg of a poorly fermentable cellulose (control group; C). Feed intake, body weight, fasting plasma glucose, insulin, free fatty acids, alanine, lactate, glycerol and β-hydroxybutyrate levels were measured weekly in anaesthetized rats. At the end of the feeding period basal hepatic glucose production (BHGP) was measured with a primed continuous infusion of [3−3H]glucose and thein vivoinsulin sensitivity in rats was quantified by the euglycaemic-hyperinsulinaemic clamp technique (0.6 and 2 U/kg per h). At that time fasting plasma glucose measured in anaesthetized rats was significantly lower in group P than in group C: 7·7 (SE 0·2) v. 8.5 (SE 0·2) mmol/l respectively (P< 0·002); plasma insulin levels were not significantly different. Neither the BHGP (mg/min per kg; C 14·8 (SE 1·3), P 15·1 (SE 1·3);n7, not significant) nor the basal metabolic clearance (ml/min per kg; 8·9 (SE 08) v. 9·9 (SE 1·1); not significant) were different between treatments. Hepatic glucose production and glucose utilization at the two insulin concentrations (approximately 500 and 1500 mU/l respectively,n7) did not differ significantly between the two groups. These results show that dietary propionate chronically ingested by normal rats could decrease fasting glycaemia, but from our findings, no effect on hepatic glucose production and whole-body glucose utilization could be clearly demonstrated.
Meal feeding and leucine utilization in pregnant rats
Authors: Weijs P. J. M. , Schreurs V. V. A. M. , Grooten H. N. A.
Published: June 2005

During pregnancy a higher amino acid requirement may be expected, but the increase in food intake does not match the increased growth rate during pregnancy. It is hypothesized that amino acid utilization can be increased during both fasting and feeding in order to account for the increased requirement. Therefore mature female rats (20 weeks old) were investigated before and at day 18 of pregnancy. Rats were fed on a high-protein (HP) diet (210 g casein/kg diet) for 3 weeks and fasted overnight Rats were then subjected to an 8 h constant infusion of L-[1-14C]leucine with continuous measurement of expired 14CO2 (as a percentage of the infused dose). After 3 h infusion a 5 g HP or low-protein (LP;75 g casein/kg diet) meal was offered for 30 min. Pregnant rats had a significantly lower percentage leucine oxidation in the fasted state (12·5 (SE 0·7) ν. 15·9 (SE 1·1); P < 0·05), which suggests improved reutilization of leucine. Meal ingestion resulted in a fast increase in 14CO2 expiration. After the LP meal the level of 14CO2 expiration decreased again after the acute response (0–1·5 h), but this was not the case after the HP meal. After the HP meal (average 1·5–5 h), no difference was observed between pregnant and non-pregnant status (36·8 (SE 1·6) ν. 35·0 (SE 2·5)). After the LP meal (average 1·5–5 h), however, the percentage leucine oxidation tended to be lower in pregnant rats but this difference did not reach statistical significance (19·7 (SE 1·1) ν. 25·8 (SE 2·8)). In conclusion, pregnancy improved leucine utilization in the fasted state, and tended to improve it after marginal protein feeding.
The effect of heat on amino acids for growing pigs
Authors: Van Barneveld R. J. , Batterham E. S. , Skingle D. C. , Norton B. W.
Published: June 2005

Experiments were conducted to determine the effect of heating field peas (Pisum sativum) on the N balance and urine, serum and plasma composition of growing pigs. In the first experiment, four diets containing raw field peas (cv. Wirrega) or field peas heated to 150° (cv. Wirrega), 165° (cv. Wirrega) or 150° (cv. Dundale) for 15 min respectively were formulated to contain 1·15 g ileal digestible N/MJ digestible energy (DE) and 036 g ileal digestible lysine/MJ DE in a sugar-based diet. Digestibility estimates were based on those for the Dundale cultivar of field peas used in previous experiments. Total urine and faeces collection from eight pigs was conducted over two 7 d collection periods with a 7 d diet change-over period. Serial blood sampling from the external jugular vein was conducted on the final day of each collection period. There was no significant difference (P > 0·05) in the N balance or apparent biological value of the field-pea treatments. Pigs fed on diets containing peas heated to 150° (cv. Wirrega) or 165° (cv. Wirrega) had a significantly lower (P < 0·01) daily output of urea and uric acid in the urine, and depressed serum protein and serum urea concentrations. Plasma lysine concentration and daily urine lysine output were not significantly different (P > 0·05) in pigs fed on heated peas. Protein excretion in the urine of pigs fed on diets containing peas heated to 165° increased 3–7 times (depending on estimation technique) the level observed in pigs fed on diets containing raw peas. A second experiment was conducted to determine the apparent ileal digestibility of N and amino acids in cv. Wirrega field peas. This study revealed that N digestibility (0·44) and lysine digestibility (0·35) in peas heated to 165° were significantly lower than the cv. Dundale estimates (0·57 and 0·62 respectively) used in diet formulations. The depressed serum and urine variables in pigs fed on heated peas were attributed to overestimation of digestibility. The results exemplify the fact that it is not possible to draw general conclusions as to the effects of heat on any particular protein concentrate. Variability in N balance experiments and problems associated with urine analysis are suggested as likely reasons for the current study not reflecting poor utilization of ileal digestible lysine from heat-treated field peas. Despite considerable variation in the results, it is possible that a large proportion of non-utilizable amino acids in heated field peas may be excreted from the pig via the urine in the form of a protein.
Effect of oat saponins on plasma and liver lipids in gerbils (Meriones unguiculatus) and rats
Authors: Önning G. , Asp N.-G.
Published: June 2005

The effects of oat saponins (a mixture of avenacosides A and B) on plasma and liver lipids in gerbils (Meriones unguiculatus) and rats were investigated. Cholesterol-containing diets high in total and saturated fat and with different avenacoside contents (zero (ethanol-extracted oats), normal (oats) and twice normal (ethanol-extracted oats plus added avenacosides)) were used. Compared with a cellulose control group the oat diets in both species gave a significantly higher cholesterol content in the HDL fraction and a significantly lower liver cholesterol content. No significant differences in total plasma cholesterol, HDL-cholesterol and plasma triacylglycerols were found, however, between the groups fed on oats with different avenacoside content. The liver weight, total liver cholesterol and free liver cholesterol were also similar, whereas the liver lipid content was significantly lower in rats given the highest amount of avenacosides compared with zero or normal amounts. The tendency was the same in gerbils. Thus, the oat saponins had only minor effects on lipid metabolism in gerbils and rats.
Both raw and retrograded starch decrease serum triacylglycerol concentration and fat accretion in the rat
Authors: de Deckere Emile A. M. , Kloots Willem J. , van Amelsvoort Johan M. M.
Published: June 2005

Male Wistar rats were meal-fed on diets containing various amounts of resistant starch in the form of raw starch (either amylomaize starch, potato starch or modified high-amylose starch) or retrograded starch (prepared from each of the starches) for 6 weeks. Two diets containing normal maize starch were fed as diets poor in resistant starch. Energy absorption (energy consumption minus faecal energy loss), growth, weight of the epididymal fat pads, serum total cholesterol and triacylglycerol concentrations and a number of intestinal and faecal variables were determined. The resistant starches affected all the variables determined except the serum total cholesterol concentration. Relationships were found between energy absorption and both growth and the weight of the fat pads, and between the weight of the fat pads and both the serum triacylglycerol concentration and the serum total cholesterol concentration. No clear differences between the effects of ihe two types of resistant starch (raw starch ν. retrograded starch) were found except that raw potato starch hardly stimulated H2excretion and led to lower amounts of propionic and butyric acids in the caecal contents than the other starches. The results suggest that dietary resistant starch reduces energy absorption leading to less abdominal depot fat and lower serum triacylglycerol concentrations.
Effects of double-blind controlled calcium supplementation on calcium absorption in chinese children measured with stable isotopes (42Ca and44Ca)
Authors: Lee Warren T. K. , Leung Sophie S. F. , Xu Y. C. , Wang S. H. , Zeng W. P. , Lau Joseph , Fairweather-Tait Susan J.
Published: June 2005

A double-blind controlled Ca supplementation trial was conducted for 6 months in thirty-four 7-year-old Chinese children from Hongkong and Jiangmen, China. The children were randomly allocated to the study group (n17) or control group (n17), and a CaCO3tablet (300 mg Ca) or a placebo tablet was taken daily. True fractional Ca absorption (TFCA) was evaluated before and after the trial using stable isotopes: 8 mg44Ca mixed in 100 g chocolate milk was given after an intravenous injection of 0·75 mg42Ca. There was no significant difference in baseline TFCA between the study group (60·6 (SD 11·4)%) and the controls (58·2 (SD9.0)%P= 0·55). Serum 25-hydroxycholecalciferol levels were comparable between the two groups (P= 0·71). After 6 months, TFCA of the study group (55·6 (SD12·7)%) was significantly lower than that of the controls (64·3 (SD10·7)%P= 0·015). By comparing the individual changes in TFCA after the trial between the two groups there was a non-significant reduction in TFCA (5·03 (SD 12·4)%P= 0·11, Wilcoxon signed-rank test) in the study group (60·6–55·6%), whereas a significant increase in TFCA (6·17(SD 7·7)%P= 0·004, Wilcoxon signed-rank test) was observed in the controls (58·2–64·3%). The differential in TFCA between the two groups after 6 months was significantly different (P= 0·001), and remained significant after adjustment for baseline dietary intakes, weight and height by multiple-regression analysis (P= 0·003). If the mechanism of TFCA from chocolate milk in response to the treatment effects is similar to that from the total diet, then our results suggest that children with adequate vitamin D status can adapt to a change in Ca intake by adjusting the efficiency of TFCA. In corollary, children on habitually-low Ca diets have a higher TFCA than the counterparts with higher Ca diets.
Energy intake and expenditure in elderly patients admitted to hospital with acute illness
Authors: Klipstein-Grobusch K. , Reilly J. J. , Potter J. , Edwards C. A. , Roberts M. A.
Published: June 2005

Studies on hospitalized elderly subjects have demonstrated that negative energy balance is common during hospitalization, but have concentrated primarily on long-stay and psychogeriatric patients. There is little information on energy balance in elderly patients admitted with acute illness from the community, despite the importance of this patient group and the presence of a number of factors likely to predispose such patients to negative energy balance. In the present study energy balance was quantified in twenty patients (eight males, mean age 82 (SD 05) years; twelve females, mean age 84 (SD 6) years) admitted from the community with acute illness, and predicted basal metabolic rate (BMR) was compared with measured resting metabolic rate (RMR). Most patients were in negative energy balance during hospitalization, and median measured energy intake (El):measured RMR ratio was 1·0 (range 0·7–1·8). The mean difference between measured El and estimated total energy expenditure was −1·3 MJ/d (range -3·4 to +2·5 MJ/d). Estimated total energy expenditure exceeded measured El in fifteen of the patients and there was a significant decline in mid-arm muscle circumference (paired t, P < 0·05) during hospitalization. We conclude that moderate negative energy balance is common in this patient group, and that these patients are at risk of undernutrition during their hospital stay.
Multi-frequency impedance for the prediction of extracellular water and total body water
Authors: Deurenberg Paul , Tagliabue Anna , Schouten Frans J. M.
Published: June 2005

The relationship between total body water (TBW) and extracellular water (ECW), measured by deuterium oxide dilution and bromide dilution respectively, and impedance and impedance index (height2/impedance) at 1, 5, 50 and 100 kHz was studied. After correction for TBW, ECW was correlated only with the impedance index at 1 and 5 kHz. After correction for ECW, TBW was best correlated with the impedance index at 100 kHz. The correlation of body-water compartments with impedance values obtained with modelling programs was lower than with measured impedance values. Prediction formulas for ECW (at 1 and 5 kHz) and TBW (at 50 and 100 kHz) were developed. The prediction errors for ECW and TBW were 1·0 and 1·7 kg respectively (coefficient of variation 5%). The residuals of both ECW and TBW were related to the ECW/TBW value. Application of the prediction formulas in a population, independently measured, revealed a slight overestimation of TBW and ECW, which could be largely explained by differences in the validation group in body-water distribution and in body builds. The ratio of impedance at 1 kHz to impedance at 100 kHz was correlated with body-water distribution (ECW/TBW). The relation is however not strong enough to be useful as a predictor. It is concluded that an independent prediction of ECW and TBW, using impedance at low and high frequency respectively, is possible, but that the bias depends on the body-water distribution and body build of the measured subject.
Variation in food group and nutrient intake with day of the week in an elderly population
Authors: Maisey Susan , Loughridge Julie , Southon Susan , Fulcher Robert
Published: June 2005

The present paper is an aalysis of 138 5- or 7-d diet diaries collected from a free-living population of people aged 68–90 years in Norwich. Men had higher intakes than women of energy and most nutrients, but patterns of variation across the week were similar for both sexes. Intakes of meat, meat products, fish and vegetables varied across the week both in frequency and amount eaten, but the other main food groups showed no significant variation. Alcohol was taken more frequently at weekends but the amount did not vary significantly. Intakes of energy, protein and many micronutrients varied significantly with day of the week, with increased intake at weekends, especially of vegetable-derived micronutrients on Sundays, and generally decreased intake on Mondays and Fridays. Nutrient densities of carotene, retinol equivalents, folate, vitamin C, pantothenate and Zn Were all highest on Sundays, providing further evidence of variation of diet quality on different days of the week.
Endogenous purine and pyrimidine derivative excretion in pregnant sows
Authors: Orue S. M. Martin , Balcells J. , Guada J. A. , Castrillo C.
Published: June 2005

The present experiment was carried out to study the endogenous losses of purine and pyrimidine derivatives from pregnant sows. Three pregnant and three non-pregnant Large White × Landrace sows were fed on a purine-free diet composed of starch, glucose, sucrose and vegetable oil, with casein as the protein source. The experiment began, for the six animals, after diagnosis of pregnancy and was divided into six 12 d periods. Urine was collected during the first 3 d of each experimental period by means of a urethral catheter for determination of allantoin, uric acid, xanthine, hypoxanthine and pseudouridine concentrations. In the absence of dietary nucleic acids (N A), allantoin and, as a consequence, excretion of total purine derivatives (PD) decreased significantly to a constant value (128·3 (se 7·07) μmol/kg metabolic live weight (W0·7) per d), an amount assumed to represent endogenous excretion. Excretion of uric acid (38·7 (SE 2·15) μmol/kg W0·75per d), hypoxanthine (21·0 (SE 2·58) μmol/kg W0·75per d) and xanthine (11·2 (SE 0·83) μmol/kg W0·75per d) were not affected by the experimental treatment, although there was a significant decrease in hypoxanthine excretion in pregnant sows (from 25·5 to 5·2 μmol/kg W0·75per d) compared with non-pregnant sows (from 26·7 to 44·8 μmol/kg W0·75per d). Creatinine excretion was not affected by pregnancy and was used as an internal urinary marker. Purine excretion, either expressed as μmol/kg W0·75per d or as the ratio PD:creatinine, was not affected by experimental treatment, although an apparent increase in pseudouridine excretion, a modified unsalvageable catabolite of RNA-pyrimidine, was found in late pregnancy (3·6 ν 52 mol/100 mol creatinine in on-pregnant sows compared with pregnant sows at 102 d collection).
Erythrocyte levels compared with reported dietary intake of marinen-3 fatty acids in pregnant women
Authors: Olsen* Sjúrdúr F. , Hansen Harald S. , Sandström Brittmarie , Jensen Benny
Published: June 2005

It is well established that marinen-3 fatty acids measured in erythrocyte phospholipids of non-pregnant subjects reflect the subjects intake of these fatty acids. In 135 pregnant women in the 30th week of gestation we compared intake of marinen-3 fatty acids and energy, estimated by a combined dietary self-administered questionnaire and interview, with fatty acids measured in erythrocyte phospholipids. Daily intake (g/d) and nutrient density of marinen-3 fatty acids (mg/MJ) correlated with then-3 fatty acid: arachidonic acid ratio (FA-ratio) with correlation coefficients of 0·48 and 0·54 respectively. In a linear regression model with three frequency questions about marine sandwiches, marine cooked meals and fish oil as explanatory variables, and the FA-ratio as dependent variable, the multiple correlation coefficient was 0·46. Conclusions from the study were (1) levels of erythrocyte fatty acids in pregnant women may be employed as a qualitative method to rank subjects according to intake of marinen-3 fatty acids; (2) with respect to the power to explain FA-ratio variability, three simple marine food frequency questions were comparable with intake of marinen-3 fatty acids assessed by an elaborate semiquantitative dietary method involving an interview.
Long-chain polyene status of preterm infants with regard to the fatty acid composition of their diet: Comparison between absolute and relative fatty acid levels in plasma and erythrocyte phospholipids
Authors: Drongelen Magritha M. H. P. Foreman-Van , Houwelingen Adriana C. V. , Kester Arnold D. M. , Jong André E. P. De , Blanco Carlos E. , Hasaart Tom H. M. , Hornstra Gerard
Published: June 2005

The long-chain polyene (LCP) status of thirty-nine premature infants (birth weight < 1800 g) was evaluated. Twenty-seven infants were fed on an artificial formula, twelve received their own mother's breast milk. Fatty acid compositions of both plasma and erythrocyte (RBC) phospholipids (PL) were determined in umbilical venous blood and in weekly postnatal blood samples until the 28th day of life. Individual fatty acid levels were expressed as absolute quantities (mg fatty acid/I plasma or RBC suspension) and as relative (mg/100 mg total fatty acids) values. The changes with time in the absolute values for 22:6n-3 and 20:4n-6 in plasma were strikingly different from those of the relative values for these fatty acids. In plasma PL the inter-group differences in the absolute postnatal values for 22:6n-3 (P< 0·0005) and 20:4n-6 (P< 0·05) and the relative values for 22:6n-3 (P< 0·02) were significant, with lower fatty acid values in the formula-fed infants. In RBC PL, no significant inter-group differences in the postnatal 22: 6n-3 and 20: 4n-6 values were found. Based on the assumption that it is desirable for formula-fed infants to achieve postnatal plasma LCP values at least comparable with those found in infants fed on human milk, the findings of the present study indicate that bothn-3 andn-6 LCP should be added to preterm infant formulas. Moreover, the additional importance of absolute fatty acid levels was demonstrated, although analytical procedures need to be standardized to enable effective comparison of results from different research groups.
Selenoprotein P and glutathione peroxidase (EC1·11·1·9) in plasma as indices of selenium status in relation to the intake of fish
Authors: Huang W. , Åkesson B. , Svensson B. G. , Schütz A. , Burk R. F. , Skerfving S.
Published: June 2005

Department of Occupational and Environmental Medicine, University of Lund, Lund, Sweden In Sweden fish is considered to be an important source of dietary Se. Therefore Se status was assessed in forty-one middle-aged men with widely varying fish consumption. Glutathione peroxidase (EC1·11·1·9) and selenoprotein P in plasma were measured by radioimmunoassay. Plasma Se among the men increased slightly with increasing consumption of fish, but no such increases in the concentrations of glutathione peroxidase and selenoprotein P in plasma were observed. Moreover, no correlation was found between plasma Se and glutathione peroxidase or selenoprotein P. Instead, glutathione peroxidase was significantly correlated with selenoprotein P (r0·73,P<0·001), indicating that both glutathione peroxidase and selenoprotein P were functional indicators of Se status in this group. The proportion of plasma Se located in glutathione peroxidase decreased with increasing plasma Se. The results suggest that the Se consumed from fish had no apparent effect on the amount of Se incorporated into the functional selenoproteins of plasma. It is concluded that in some cases selenoproteins may be better biological markers of Se status than the total concentration of Se.
Distribution of activity of hydrolytic enzymes in the digestive tract of rabbits
Authors: Marounek M. , Vovk S. J. , Skřivanová V.
Published: June 2005

Activities of twelve hydrolytic enzymes in the digestive tract of young rabbits before weaning (4 weeks old) and adult rabbits (3 months old) were measured. The principal digestive enzymes in both groups of rabbits appeared to be amylase (EC3.2.1.1), maltase (EC3.2.1.20), pectinase (EC3.2.1.15) and proteinases. The stomach of young rabbits contained most of the lipolytic activity and 45.7 % of the total proteolytic activity of the digestive tract. The highest specific activities (per g digesta) of amylase, maltase and proteinase in young rabbits were found in the small intestine. Total activities (per segment) of amylase and maltase in the small intestine and the caecum were similar. Activities of cellulase (EC3.2.1.4), inulinase (EC3.2.1.7) and β-glucosidase (EC3.2.1.21) were low and activity of pectinase was fairly high in all segments of the digestive tract. The highest activity of urease (EC3.5.1.5) was found in the caecum. Enzymic profiles of the colonic chymus resembled those of the caecum. Total hydrolytic activity was lower in the colon than in the caecum. Specific activities of amylase and invertase (EC3.2.1.26) were lower and those of inulinase and lactase (EC3.2.1.23) higher in 4-week-old rabbits than in 3-month-old rabbits. Gastric proteinase represented almost half of the total proteolytic activity of the digestive tract, whereas lipolytic activity of gastric contents was not found in measurable quantities in adult rabbits. The caecal contents of adult rabbits contained most of the total activity of lipase (EC3.1.1.3), cellulase, xylanase (EC3.2.1.32), pectinase, lactase, invertase, β-glucosidase and urease present in the digestive tract. The presence of microbial enzymes (pectinase, cellulase, xylanase, inulinase and urease) in non-fermentative segments of the digestive tract reflects the reingestion of caecal contents during coprophagy.