bluuebunny/crossref_metadata_2025 huggingface dataset:
Urinary excretion of magnesium and calcium as an index of absorption is not affected by lactose intake in healthy adults
Authors: Brink Elizabeth J. , van Beresteijn Emerentia C. H. , Dekker Pieter R. , Beynen Anton C.
Published: September 2005

The effect of lactose on the urinary excretion of Mg and Ca, as an index of absorption, was studied in a double-blind, crossover study during three 1-week periods. Twenty-four healthy, lactose-tolerant, adult volunteers maintained their habitual diets with the exception that all lactose-containing dairy products in the diet were replaced by 600 g/d of three specially prepared dairy products. These products were based on either lactose-enriched cow's milk or lactose-enriched, lactase (EC3.2.1.23)-treated cow's milk, with or without added Mg, and were given in turn during 1 week. Lactose intake was increased by 127 mmol/d (46 g/d) while taking the lactose-enriched products. While taking the Mg-enriched products, Mg intake was increased by 2.8 mmol/d (69 mg/d) which was equivalent to 17% of the habitual Mg intake. Apart from the lactose and Mg intake, nutrient intake was comparable during the three dietary periods. Urinary excretions of Mg and Ca were used as indicators for their absorption. Mg supplementation significantly increased urinary Mg excretion by 0.97 mmol/d (equivalent to an increase of 18%,P< 0.001), indicating that urinary Mg excretion is a valid indicator for intestinal Mg absorption. Hydrolysis of lactose did not affect urinary excretion of Mg and Ca, which implies that lactose intake does not affect the absorption of Mg and Ca in healthy adults.
The influence of a low-boron diet and boron supplementation on bone, major mineral and sex steroid metabolism in postmenopausal women
Authors: Beattie John H. , Peace Heather S.
Published: September 2005

An increase in dietary intake of B from 0.25 to 3.25 mg/d has been reported to increase plasma oestradiol and testosterone and decrease urinary Ca excretion in postmenopausal women. Consequently, it is suggested that the higher level of B intake could reduce bone loss associated with the menopause and cessation of ovarian function. The present study was designed to investigate the effect of a B supplement on bone mineral absorption and excretion, plasma sex steroid levels and urinary excretion of pyridinium crosslink markers of bone turnover in healthy postmenopausal volunteers. The women were accommodated in a metabolic unit, given a low-B diet (LBD; 0.33 mg/d) for 3 weeks and were asked to take a B supplement of 3 mg/d in addition to the LBD for a further 3 weeks. Changing B intake from 0.33 to 3.33 mg/d had no effect on minerals, steroids or crosslinks. However, the LBD appeared to induce hyperabsorption of Ca since positive Ca balances were found in combination with elevated urinary Ca excretion. This phenomenon may have inhibited or obscured any effect of B.
The calcium and phosphorus intakes of rural Gambian women during pregnancy and lactation
Authors: Prentice Ann , Laskey M. Ann , Shaw Jacquie , Hudson Geoffrey J. , Day Kenneth C. , Jarjou Landing M. A. , Dibba Bakary , Paul Alison A.
Published: September 2005

The Ca and P intakes of 148 pregnant and lactating women in a rural village in The Gambia. West Africa, have been estimated by direct weighing of food on a total of 4188 d. The Ca and P contents of local foods were determined by analysis of raw ingredients, snack foods and prepared dishes. Information about the contribution of mineral-rich seasonings was obtained. Efforts were made to discover unusual sources of Ca that might not be perceived as food by subject or observer. The main contributors to daily Ca intake were shown to be leaves, fish, cereals, groundnuts and local salt. Cow's milk accounted for only 5 % of Ca intake. Unusual sources of Ca were discovered, namely baobab (Adansonia digitata) fruit and selected earths, but these were consumed infrequently and their contributions to Ca intakes were small. Cereals and groundnuts were the main sources of P. Ca and P intakes (mg/d) were shown to average 404 (SD 110) and 887 (SD 219) respectively. Seasonal changes in the availability of leaves, cereals and groundnuts resulted in variations in Ca and P intakes. The rainy season was associated with increased Ca intakes (by 16%) but decreased P consumption (by 15%). No difference was observed in Ca intake between pregnant and lactating women but P intake in lactation was 11 % higher than that in pregnancy during the post-harvest season. The implications of these low Ca intakes require investigation.
Effects of galacto-oligosaccharide and bacterial status on mucin distribution in mucosa and on large intestine fermentation in rats
Authors: Meslin J. C. , Andrieux C. , Sakata T. , Beaumatin P. , Bensaada M. , Popot F. , Szylit O. , Durand M.
Published: September 2005

The purpose of the present paper was to study the effects of a dietary undigestible carbohydrate and intestinal microflora on mucin distribution (neutral, acid, sulphonated), glycolytic activities: η-D-galactosidase (EC3.2.1.23),N-acetyl-η-D-galactosaminidase (Ec3.2.1.43),N-acetyl-η-D-gluco-saminidase (EC3.2.1.30), β-L-fucosidase (EC3.2.1.51) and bacterial metabolism (gas production, short-chain fatty acids (SCFA) and lactic acid caecal concentration) in germ-free (GF), conventional (CV) and heteroxenic (HE) rats (GF rats associated with a human flora). Rats were fed on either a control diet or a diet containing 40 gtrans-galactosylated oligosaccharide (TOS)/kg. In GF rats fed on the control diet caecal pH was almost neutral and glycolytic activities negligible. The number of mucus- containing cells increased from the caecum to the colon for the three types of mucin. TOS had no effect in the caecum but it modified mucin cell repartition in the colon. In CV and HE rats fed on the control diet caecal pH was similar (6.8), but caecal SCFA and lactic acid concentrations (μmol/g) and gas production (m1/24 h) were higher in CV (70, 5.9 and 2.3 respectively) than in HE rats (32, 4.6 and 0.4 respectively). In CV, as in HE rats, acid-mucin-containing cells increased from the caecum to the colon and glycolytic activities were similar. TOS reduced acid-mucin-containing cells in the caecum of CV rats by twofold but had no effect in either the caecum or the colon of HE rats. TOS strongly increased η- galactosidase activity and slightly modified the other glycolytic activities. Its effect on bacterial metabolites depended on bacterial status. However, comparison between CV and HE rats showed no evident relationship between the number of mucus-containing cells and measured bacterial metabolites. Differences between CV and HE rats might be due to bacterial microflora specificity. TOS had an intrinsic effect on mucus cell distribution in the colon of GF rats. In CV and HE rats the presence of the flora abolished this effect.
The influence of wheat bran and pectin on the distribution of water in rat caecal contents and faeces
Authors: Armstrong Elizabeth F. , Eastwood Martin A. , Gordon Brydon W.
Published: September 2005

Wheat bran and pectin (100 g/kg) were added to a basal diet and fed to rats. An in vitro dialysis technique was used to measure the distribution of caecal and faecal water between the bound, i.e. that held by bacteria and undigested macromolecules, and free water. Bran increased wet (67%) and dry (74%) faecal weight. Pectin increased wet faecal weight (59 %), but did not influence dry weight. In faeces both bran and pectin increased the amount of total and bound water, but only pectin increased total and bound water when expressed on a dry weight basis. Caecal wet (90%) and dry (67%) weights increased with pectin but not with bran. Bran did not change total water but increased bound water whereas pectin increased both. This suggests that water contributed more to the increase in stool bulk in the pectin- supplemented animals due to free and bound water associated with both increased numbers of bacteria and residual pectin. Pectin altered the distribution of water in faeces. Bran has no effect on water distribution and is only partly fermented. The residual water-holding capacity leads to an increased wet and dry stool output.
Protein synthesisin vivoin rats fed on lipid-rich liquid diets
Authors: Estornell Ernesto , Barber Teresa , Cabo José
Published: September 2005

Changes in tissue composition and protein synthesis ratio were studied in the major tissues of the body in young rats fed on lipid-rich, isonitrogenous purified liquid diets, a convenient method for inducing voluntary overfeeding under controlled nutritional conditions. Overfed rats showed faster growth induced by the energy excess. Analysis of tissue composition (protein, DNA and RNA contents) revealed that growth was due mainly to tissue hyperplasia in which protein and DNA contents increased in parallel. Fractional protein synthesis ratio measuredin vivoby the flooding-dose method of phenylalanine showed a marked increase in all tissues. This change could be attributed to an increase in the ribosomal activity for protein synthesis in most tissues. Therefore, our results indicate that addition of a supplementary energy source (as lipids) to a well-balanced diet improves growth and protein synthesis in growing rats.
Gastro-jejunal digestion of soya-bean-milk protein in humans
Authors: Baglieri Agnes , Mahe Sylvain , Zidi Semia , Huneau Jean-Francois , Thuillier Francois , Marteau Philippe , Tome Daniel
Published: September 2005

In order to determine how soya-bean proteins are digested and metabolized in the human intestine before colonic bacterial fermentation and to estimate their true digestibility, the gastro-jejunal behaviour of soya-bean proteins in water and in two other forms (a concentrated soya-bean-protein solution (isolate) and a drink composed of crude soya-bean proteins (soymilk)) was studied in humans. Experiments were carried out in eight healthy volunteers using a double-lumen steady-state intestinal perfusion method with polyethyleneglycol (PEG) as a non-absorbable volume marker. Gastric emptying and N and electrolyte contents of the jejunal digesta were analysed. Gastric half-emptying time (min) of the liquid phase after water ingestion (12·59 (SE 0·12)) was shorter (P< 0.05) than those for soymilk (37·74 (SE 11·57)) and isolate (36·52 (SE 11·23)). Electrolytic balances showed that for all meals, Na+, Cl−and K+were secreted when Ca2+ was efficiently absorbed from the jejunal lumen. Gastro-jejunal N absorption for isolate and soymilk were 63 and 49% respectively, and were not significantly different from one another; after water ingestion, endogenous N was estimated to be 21 mmol. An estimate of the exogenous: endogenous values for the effluents was obtained from the amino acid compositions of soymilk and effluents after water or soymilk ingestion, indicating that 70% of the total N was exogenous and 30% endogenous. Under these conditions the endogenous fraction represented 31 mmol after soymilk ingestion and the gastro-jejunal N balance indicated that 54% of the soymilk was absorbed. This finding indicates that the true gastro-jejunal digestibility of soya-bean proteins is similar to that of milk proteins.
Intestinal absorption of medium chain fatty acids: in vivo studies in pigs devoid of exocrine pancreatic secretion
Authors: Guillot E. , Lemarchal P. , Dhorne T. , Rerat A.
Published: September 2005

In order to study the influence of pancreatic enzyme secretion on the intestinal absorption of mediumchain fatty acids (MCFA), three growing pigs (mean body-weight 61 kg) with ligated and severed pancreatic ducts were fitted with a permanent fistula in the duodenum and with two catheters in the portal vein and carotid artery respectively. An electromagnetic flow probe was also set up around the portal vein. A mixture of octanoic and decanoic acids, esterified as medium-chain triacylglycerols, together with maltose dextrine and a nitrogenous fraction was continuously infused for 1 h into the duodenum. Samples of blood were withdrawn from the two vessels at regular intervals of time for 8 h and further analysed for their non-esterified octanoic and decanoic acid contents. The concentrations of non-esterified octanoic and decanoic acid in the portal blood increased slowly after the beginning of each infusion, reaching about 10 times higher values than the basal level. Only 26% of octanoic acid infused in the duodenum and 27% of decanoic acid were recovered in the portal flow throughout each experiment. The possible mechanisms underlying the appearance of MCFA in the portal blood in the absence of pancreatic enzyme secretions and the importance of duodenal absorption of MCT in such physiological conditions have been discussed.
Changes in plasma phospholipid fatty acids and their relationship to disease activity in rheumatoid arthritis patients treated with a vegetarian diet
Authors: Haugen Margaretha A. , Kjeldsen-Kragh Jens , Bjervea Kristian S. , Høstmark Arne T. , Førre Øystein
Published: September 2005

In a controlled clinical trial we have recently shown that patients with rheumatoid arthritis (RA) improved after fasting for 7–10 d and that the improvement could be sustained through 3.5 months with a vegan, diet and 9 months with a lactovegetarian diet. Other studies have indicated that the inflammatory process in R A can be reduced through manipulation of dietary fatty acids. A switch to a vegetarian diet significantly alters the intake of fatty acids. Therefore, we have analysed the changes in fatty acid profiles of the plasma phospholipid fraction and related these changes to disease activity. The concentrations of the fatty acids 20: 3n-6 and 20: 4n-6 were significantly reduced after 3.5 months with a vegan diet (P< 0.0001 andP< 0.01 respectively), but the concentration increased to baseline values with a lactovegetarian diet. The concentration of 20: 5n-3 was significantly reduced after the vegan diet (P< 0.0001) and the lactovegetarian diet periods (P< 0.01). There was no significant difference in fatty acid concentrations between diet responders and diet non-responders after the vegan or lactovegetarian diet periods. Our results indicate that the changes in the fatty acid profiles cannot explain the clinical improvement.
Dietary fructose v. glucose in rats raises urinary excretion, true absorption and ileal solubility of magnesium but decreases magnesium retention
Authors: Heijden Annet Van Der , Berg Gerrit J. Van Den , Lemmens Arnoldlna G. , Beynen Anton C.
Published: September 2005

Apparent Mg absorption, that is Mg intake minus faecal excretion, was found to be greater in rats fed on diets containing fructose instead of glucose. This effect of fructose was accompanied by enhanced urinary excretion and diminished retention of Mg. True Mg absorption was then determined with the use of oral and intraperitoneal administration of tracer doses of 28Mg. True Mg absorption was significantly greater in rats fed on fructose. There was no significant effect of fructose v. glucose on faecal excretion of endogenous Mg. It was hypothesized that fructose enhances the solubility of Mg in the ileal lumen and thereby facilitates its absorption. The distribution of Mg between the solid and liquid phases of the ileum was determined in rats fed on either glucose or fructose. Fructose reduced the amount of Mg in the solid phase but raised both the amount and the concentration of Mg in the liquid phase. We conclude that the dietary-fructose-induced stimulation of Mg absorption in rats is caused by a raised solubility of ileal Mg. but the mechanism by which fructose exerts this effect and why it was not associated with a decrease in faecal excretion of endogenous Mg remain unknown. Dietary fructose v. glucose did not systematically affect the apparent absorption of Ca and P.
Comparison of dietary assessment methods in nutritional epidemiology: weighed records v. 24 h recalls, food-frequency questionnaires and estimated-diet records
Authors: Bingham S. A. , Gill C. , Welch A. , Day K. , Cassidy A. , Khaw K. T. , Sneyd M. J. , Key T. J. A. , Roe L. , Day N. E.
Published: September 2005

Women (n 160) aged 50 to 65 years were asked to weigh their food for 4 d on four occasions over the period of 1 year, using the PETRA (Portable Electronic Tape Recorded Automatic) scales. Throughout the year, they were asked to complete seven other dietary assessment methods: a simple 24 h recall, a structured 24 h recall with portion size assessments using photographs, two food-frequency questionnaires, a 7 d estimated record or open-ended food diary, a structured food-frequency (menu) record, and a structured food-frequency (menu) record with portion sizes assessed using photographs. Comparisons between the average of the 16 d weighed records and the first presentation of each method indicated that food-frequency questionnaires were not appreciably better at placing individuals in the distribution of habitual diet than 24 h recalls, due partly to inaccuracies in the estimation of frequency of food consumption. With a 7 d estimated record or open-ended food diary, however, individual values of nutrients were most closely associated with those obtained from 16 d weighed records, and there were no significant differences in average food or nutrient intakes.
Food Photography I: the perception of food portion size from photographs
Authors: Nelson M. , Atkinson M. , Darbyshire S.
Published: September 2005

Fifty-one male and female volunteers aged 18–90 years from a wide variety of social and occupational backgrounds completed 7284 assessments of portion size in relation to food photographs. Subjects were shown six portion sizes (two small, two medium and two large) for each of six foods, and asked to compare the amount on the plate in front of them to (a) a series of eight photographs showing weights of portions from the 5th to the 95th centile of portion size (British Adult Dietary Survey), or (b) a single photograph of the average (median) portion size. Photographs were prepared either in colour or in black and white, and in two different sizes. The order of presentation of foods; use of black and white or colour; the size of photographs; and presentation of eight or average photographs were each randomized independently. On average, the mean differences between the portion size presented and the estimate of portion size using the photographs varied from -8 to + 6g (-4 to + 5%) for the series of eight photographs, and from -34 to −1g (-23 to + 9%) for the single average photograph. Large portion sizes tended to be underestimated more than medium or small portion sizes, especially when using the average photograph (from -79 to -14g, -37 to -13%). Being female, 65 years and over, or retired, or seeing photographs in colour, were all associated with small but statistically significant overestimations of portion size. Having a body mass index ≥ 30 kg/m2was associated with an 8% underestimate of portion size. We conclude that use of a series of eight photographs is associated with relatively small errors in portion size perception, whereas use of an average photograph is consistently associated with substantial underestimation across a variety of foods.
Effect of dose and modification of viscous properties of oat gum on plasma glucose and insulin following an oral glucose load
Authors: J.Wood Peter , Braaten Jan T. , Scott Fraser W. , Riedel K. Doreen , Wolynetz Mark S. , Collins Maurice W.
Published: September 2005

An extract from oats known as oat gum (OG) is composed mainly of the polysaccharide (1→3) (1→4)-β-D-glucan, which is highly viscous in aqueous solution. Viscous polysaccharides are known to attenuate postprandial plasma glucose and insulin responses. The purposes of this study were to determine the dose–response to OG and establish quantitatively the effect of viscosity on plasma glucose and insulin levels of healthy humans consuming 50 g glucose. Increasing the dose of OG successively reduced the plasma glucose and insulin responses relative to a control without gum. Reduction of the viscosity of OG by acid hydrolysis reduced or eliminated the capacity to decrease postprandial glucose and insulin levels. The ability of OG to modify glycaemic response was unchanged following agglomeration in the presence of maltodextrin. Agglomerated gum dispersed smoothly in a drink without formation of lumps, and development of maximum viscosity was delayed. These properties improve palatability. There was a highly significant linear relationship between log[viscosity] of the mixtures consumed and the glucose and insulin responses. The relationship shows that 79–96% of the changes in plasma glucose and insulin are attributable to viscosity, and that changes occur at relatively low doses and viscosities.
Zinc changes in blood and urine during cyclic pareteral nutrition: relationships with amino acid metabolism
Authors: Faure H. , Leverve X. , Arnaud J. , Boujet C. , Favier A.
Published: September 2005

Serum Zn, ultrafiltrable Zn and amino acids in serum and urine samples of twenty-seven patients receiving cyclic (12 h/24 h) parenteral nutrition were measured. These samples were collected in patients after a 12 h period of parenteral nutrition, and in the evening after 12 h without parenteral nutrition. The same determinations were performed in ten control subjects who followed the same sampling scheme. Total serum ultrafiltrable Zn showed no significant variations in the patients during parenteral nutrition, and was not significantly different in the two groups although the proportion of the Zn present in the ultrafiltrable fraction was elevated. Serum cystine levels were significantly higher (P= 0·05) in the patients than the control subjects, and cystine excretion was also higher in patients (P< 0·05) and increased after parenteral nutrition (56·0 (SE 6·5)v. 147·1 (SE 20·6) m/12 h;P< 0·001). Histidine levels did not vary significantly in serum after parenteral nutrition and were not different in the patients in comparison with the control subjects. Histidine excretion was not different in the two groups but increased significantly during parenteral nutrition (P< 0·05). Serum albumin was significantly depressed in the patients compared with the control subjects (45·3 (SE 1·5)v. 33·9 (SE 1·5) g/l;P< 0·001). These results suggest that cystine infusion and excretion relate to the changes occurring in serum Zn and in urinary Zn excretion.
Influence of Korean pine (Pinus koraiensis)-seed oil containingcis-5,cis-9,cis-12-octadecatrienoic acid on polyunsaturated fatty acid metabolism, eicosanoid production and blood pressure of rats
Authors: Sugano Michihiro , Ikeda Ikuo , Wakamatsu Kosaburo , Oka Takayuki
Published: September 2005

The effects of dietary Korean pine (Pinus koraiensis)-seed oil containing a peculiar trienoic acid (cis-5,cis-9,cis-12-18:3, pinolenic acid, approximately 18%) on various lipid variables were compared in rats with those of flaxseed (Linum usitatissimumL.) oil, safflower (Carthamus tinctoriusL.) oil and evening primrose (Oenothera biennisL.) oil under experimental conditions where the effects of different polyunsaturated fatty acids could be estimated. In Sprague-Dawley rats fed on diets containing 100 g fat and 5 g cholesterol/kg, the hypocholesterolaemic activity of pinolenic acid was intermediate between α-linolenic and linoleic acids. Analysis of the fatty acid composition of liver phosphatidylcholine indicated that, in contrast to α-linolenic acid, pinolenic acid does not interfere with the desaturation of linoleic acid to arachidonic acid. However, the effects on ADP-induced platelet aggregation and aortic prostacyclin production were comparable. When spontaneously hypertensive rats were fed on diets containing 100 g fat/kg but free of cholesterol, γ-linolenic and pinolenic acids, as compared with linoleic acid, increased prostacyclin production and tended to reduce platelet aggregation. In addition, pinolenic acid attenuated the elevation of blood pressure after 5 weeks of feeding. Thus, the results of the present studies indicate the beneficial effects of pinolenic acid on various lipid variables.
Effects of short- and long-term feeding of L-carnitine and congeners on the production of eicosanoids from rat peritoneal leucocytes
Authors: Garrelds Ingrid M. , Elliott Graham R. , Zijlstra Freek J. , Bonta Iván L.
Published: September 2005

The effect of short- and long-term feeding with L-carnitine, L-acetyl carnitine and L-propionyl carnitine on the production of eicosanoids frontin vitrostimulated carrageenan-induced rat peritoneal macrophages was investigated. Both young (4 weeks) and old (18 months) rats were used. A lower number of cells was isolated from the peritonea of treated than control young rats after 4 d feeding, but after 60 d no differences were observed. A similar reduction in cell number was found when old animals were given L-acetyl carnitine or L-propionyl carnitine (acutely) or L-acetyl carnitine or L-carnitine (chronically). Plasma carnitine levels were higher in young rats given carnitine both chronically and acutely. Carnitine derivatives were without effect. In contrast, levels of total carnitine in the plasma of old rats given L-carnitine and L-acetyl carnitine for 4 d and 60 d were higher than in controls. There was no correlation between total plasma carnitine level and effects on prostaglandin, thromboxane and leukotriene B4(LTB4) production. In young rats the most important changes were observed in relation to the production of prostacyclin (PGI2), measured as 6 keto-prostaglandin Flα. Prostacyclin production was higher in the groups given carnitine or its derivatives. The net result of the changes in PGI2was that the 6 keto-prostaglandin F1α: thromboxane B2and the 6 keto-prostaglandin Flα:LTB4ratios tended to be higher in cells from young animals following short-term feeding with L-carnitine. When young rats were given carnitine compounds for 60 d PGI2production was lower in cells from L-acetyl carnitine- and L-propionyl carnitine-fed animals. The net result of the changes in PGI2was that the 6 keto-prostaglandin F1α: thromboxane B2and the 6 keto-prostaglandin F1α:LTB4ratios were lower in cells from animals fed with carnitine compounds. In old rats the PGI2production was lower after short-term feeding with carnitine compounds and was higher after long-term feeding. LTB4production was lower after L-carnitine and L-acetyl carnitine treatment for 4 d and also lower after 60 d treatment with L-acetyl carnitine. The net results of the changes in PGI2were that the 6 keto-prostaglandin F1α: thromboxane B2and the 6 keto-prostaglandin F1α:LTB4ratios were lower after short-term feeding of all three compounds and higher after the long-term treatment with L-acetyl carnitine and L-propionyl carnitine in old rats. By long-term treatment with low-dose aspirin of patients with heart failure and claudication, the 6 keto-prostaglandin F1α: thromboxane B2ratio is positively increased, which is a beneficial cardioprotective effect. The mechanism of action of carnitine in heart failure and claudication could also be achieved by an increase of this ratio. Our results suggest that elderly patients could be treated chronically by carnitine to obtain this beneficial effect.
The influence of exercise on the energy requirements of adult males in the UK
Authors: Haggarty P. , McNeill G. , Manneh M. K. Abu , Davidson L.
Published: September 2005

Energy expenditure was measured over 10 d using the doubly-labelled water (DLW) and activity diary methods in summer and winter in subjects with ‘light’ occupations but leisure activities which ranged from ‘non-active’ to ‘very active’. The basal metabolic rate (BMR) and the energy cost of activities were determined by indirect calorimetry. The Department of Health (1991) predicted BMR for the group (6·89 (SD 0·30) MJ/d; n 18) was not significantly different from the measured value (7·17 (SD 0·70) MJ/d; n 18). The range of DLW-derived expenditure values within the group was BMR X 1·41 to 2·41. The largest seasonal change within individuals was BMR X 0·5. The energy expenditure of the group as a whole was lower in winter (BMR X 1·88; SD 0·33; n 9) than summer (BMR X 2·01; SD 0·30; n 9) though the difference was not statistically significant. The average summer and winter DLW-derived expenditure was BMR X 1·96 (SD 0·31; n 17). The activity diary estimate of expenditure was BMR X 1·79 (SD 0·32; n 17). In a subset of the group who were representative of the most active 26% of all adult males in the UK, the DLW-derived expenditure was BMR X 2·08 (SD 0·24; n 11). This is higher than the highest Department of Health (1991) estimate of BMR X 1·6 for individuals in light occupations. The measured energy costs of low-intensity activities were similar to those presented in the Department of Health (1991) report but the value determined for running (BMR X 13·08; SD 2·4; n 6) was higher than the highest value in the report (BMR X 6 to 8). The results indicate that the recent Department of Health (1991) reference values for energy may underestimate the expenditure of a significant proportion of the UK population largely because the energy costs of activity used in the report to calculate expenditure do not accurately reflect those achieved during active leisure in individuals who take regular exercise.
Idendification of sulphur-rich proteins which resist rumen degradation and are hydrolysed rapidly by intestinal proteases
Authors: Hancock Kerrie R. , Ealing Paul M. , White Derek W.R.
Published: September 2005

Several proteins with high proportions of S-containing essential amino acids were incubated in sheep rumen fluidin vitroand their rate of digestion was examined by sodium dodecyl sulphate-polyacrylamide-gel electrophoresis. The S-rich proteins rice prolamin (10 kDa), maize zein (10 kDa) and the 3·2 kDa pumpkin (Cucurbita maximaL.) trypsin inhibitor-1 (CMTI-1) were highly resistant to rumen fluid degradation, relative to control proteins of known degradation rate (casein, bovine serum albumin (BSA) and pea (Pisum sativum) albumin-1 (PA1)). Comparison of PA1 and a recombinant N-terminal epitope-tagged PA1 indicated that addition of the epitope caused a slight increase in resistance to rumen degradation. The proteins were also incubated with a mixture of trypsin (EC3·4·21·4) and chymotrypsin (EC3·4·21.1). PA1, BSA and casein were hydrolysed less rapidly than rice prolamin, maize zein and CMTI-1. Digestion by these intestinal proteases appeared to be complete. Thus, the prolamin, zein and CMTI-1 proteins are suitable candidates for expression as foreign proteins in pasture plants to increase throughput and uptake of essential amino acids in sheep.
True fractional calcium absorption in Chinese children measured with stable isotopes (42Ca and44Ca)
Authors: Lee Warren T.L. , Leung Sophie S.F. , J.Fairweather-Tait Susan , Leung Dora M.Y. , Tsang Heidi S.Y. , Eagles John , Fox Tom , Wang S.H. , Xu Y.C. , Zeng W.P. , Lau Joseph , Masarei J.R.L.
Published: September 2005

True fractional Ca absorption (TFCA) was compared in children with different habitual Ca intakes using a double-label stable-isotope technique. Chinese children aged 7 years from Hongkong (n22) and Jiangmen (n12) participated in the study. An oral administration of 8 mg44Ca in 100 g chocolate milk was given shortly after an intravenous injection of 0·75 mg42Ca. Ca isotopic ratios were determined in urine samples collected 24 h later using thermal-ionization mass spectrometry. There was no significant difference in TFCA between Jiangmen and Hongkong children (P=0·16). TFCA of a lower-Ca-intake group (Ca > 500 mg/d,n19) with mean Ca intake 359 mg/d was 63·1 (SD 10·7)%; and that of a higher-Ca-intake group (Ca > 500 mg/d,n15) with mean Ca intake 862 mg/d was 54·8 (SD 7·3)%; the difference in TFCA was significant (P=0·016). Serum levels of 25-hydroxycholecalciferol of the children were adequate (33·7 (SD 7·7) ng/ml). The present study indicates that growing children accustomed to a low-Ca diet appear to be able to enhance their absorptive capacity. If it is assumed that dietary Ca absorption by Chinese children resembles their TFCA from a single meal of chocolate milk, then the recommended dietary allowance (RDA) for Ca for Chinese children would be lower than the US RDA (800 mg/d), which is based on an estimated 40% Ca absorption as reported for Caucasian children. A comparative absorption study is necessary to determine whether there is any difference in TFCA between Caucasian and Chinese children.
The effect of condensed tannins in Lotus corniculatus on plasma metabolism of methionine, cystine and inorganic sulphate by sheep
Authors: Wang Yuxi , Waghorn G. C. , Barry T. N. , Shelton I. D.
Published: September 2005

Fresh Lotus corniculatus containing 27 g extractable condensed tannin (CT)/kg dry matter (DM) and 8 g bound CT/kg DM was fed at hourly intervals to sheep held in metabolism cages to study the effects of CT on nutrient digestion and on metabolism of methionine, cystine and inorganic sulphate in plasma. Polyethylene glycol (PEG) was continuously infused into the rumen of half the sheep to remove the effects of CT. Principal measurements in the two groups were plasma irreversible loss (IRL) rate and interconversions of methionine, cystine and inorganic sulphate using 35S labelling. CT in Lotus corniculatus had no effects on the apparent digestion of cellulose and minerals, slightly depressed DM, organic matter and hemicellulose digestion and markedly reduced the apparent digestion of N (P 0·01). The concentration of NH3 and molar proportions of iso-butyric acid, iso-valeric acid and n−valeric acid in rumen fluid were markedly increased by the PEG infusion (P 0·01), whereas total volatile fatty acid concentration and molar proportions of acetic acid, propionic acid and n−butyric acid were not affected. PEG infusion temporarily increased rumen protozoa numbers. CT greatly increased the IRL of plasma cystine (131·1 v. 7·0 μmol/min; P 0·05) and reduced IRL of plasma inorganic sulphate (36·8 v. 48·1 μmol/min; P 0·01) but had no effect on methionine IRL. CT increased transulphuration of methionine to cystine (4·37 v. 1·24 μmol/min; P 0·05), increased cystine entering the plasma from whole-body protein turnover plus absorption from the small intestine (9·34 v. 5·75 μmol/min; P 0·05) and increased cystine flux to body synthetic reactions (11·89 v. 5·41 μmol/min; P 0·05). CT had no effect on the proportion of methionine total flux transferred to sulphate (0·05 v. 0·06; P 0·05), reduced the proportion of methionine flux transferred to body synthetic reactions (0·68 v. 0·86) and markedly reduced the proportion of cystine flux transferred to sulphate (0·09 v. 0·27; P 0·01). It was concluded that CT in Lotus corniculatus reduced rumen protein degradation and markedly increased utilization of plasma cystine for body synthetic reactions.
Effective energy: a concept of energy utilization applied across species
Authors: Emmans G.C.
Published: September 2005

An energy system is described in which, in both single-stomachedand ruminant animals, the heat increment of feeding is considered to be linearly related to five measurable quantities. For both kinds of animals there of the quantities, with their heat increments in parentheses, are urinary N(wu;kJ/g),faec alorganic matter (wd; kJ/g) and positive protein retention (wp; kJ/g). Inruminants the other two, with their heat increments in parentheses, are CH4energy (wm; kJ/kJ) and positive lipid retention (w1;kJ/g); in single-stomached animals they are positive lipid retention from feed lipid (wu; kJ/g), and positive lipid retention not from feed lipid (w1; kJ/g). Data from suitable experiments on steers, pig sandchickens were used to test the system and to estimatewu29·2, wd3·80, wp36.5, wm0·616, w116·4 and w114·4. The values for wu, wd, wm and (wI–wII) allow an energy scale, called effective energy, to be defined for both single-stomached animals and ruminants. On this energy scale the values of wp and w1, to gether with the heats of combustion of protein and lipid of 23·8 and 39·6 kJ/g respectively, allow the energyr equirement to be expressed as (MH+ 50 PR+56 LR) for both kinds of animal, where PR and LR are the rates of positive protein an lipid retention (g/d), and MH is the maintenance heat production (kJ/d) which can be estimated as 0·96 of the fast in gheat production. The effective energy (EE) yielded toaruminant animal by a feeding redient can be estimated as EE (MJ/kg organic matter)=1·15 ME–3·84–4·67 DCP, where ME is the metabolizable energy value (MJ/kg organic matter)and DCP is the digested crude protein content (kg/kg organic matter) with both measured at maintenance. Alternatively, EE can be estimated as EE (MJ/kg)=GE (d–0·228)–4·67 DCP, where GE is the gross energy (MJ/kg)and d is the energy digestibility (MJ/MJ) also measured at maintenance. The EE yielded to a single-stomached animal can be estimated as EE(kJ/g)=1·17 ME–4·2 CP–2·44, where ME(kJ/g)is measured at, orcorrected to, zero N-retention and CP (g/g)is the crude protein (N×6·25) content of the feeding redient. The system is simpler for ruminants, and more accurate for both kind soft animal, than those no win use. As effective energy values can be tabulated foring redients, and are additivet othe extent that ME values are additive, they can be used to formul at ediet susing line ar programming.
Prediction equations for the estimation of body composition in the elderly using anthropometric data
Authors: Visser Marjolein , Heuvel Ellen Van Den , Deurenberg Paul
Published: September 2005

To study the relationship between health and nutritional status in elderly populations, information about body composition is essential. To collect this information in large epidemiological studies, practical methods based on anthropometric data must be available. In the present study the relationship between body composition, determined by densitometry, and anthropometric data in 204 elderly men and women, aged 60–87 years, was analysed. Existing prediction equations described in the literature, and mainly based on young and middle-aged subjects, generally underestimated percentage body fat in the elderly study population. Therefore, new prediction equations were developed, based on sex and the sum of two (biceps and triceps) or four (biceps, triceps, suprailiaca and subscapula) skinfolds or the body mass index (BMI). Addition of age or body circumferences to the models did not improve the prediction of body density. Internal cross validation and external validation revealed that the formulas are valid for the estimation of body density in elderly subjects. The standard errors of estimate of the three models, expressed as percentage body fat, were 5.6, 5.4 and 4.8% respectively.
The effect of breed on the relationship between feed composition and the efficiency of protein utilization in pigs
Authors: Kyriazakis I. , Dotas D. , Emmans G.C.
Published: September 2005

The objective of the present experiment was to test whether the relationship between feed composition and the efficiency of protein utilization in pigs was different between two very different breeds. Fortyeight entire male pigs, half Large White × Landrace (LW ×) and half Chinese Meishan (CM), were assigned at 13 kg live weight either to an initial slaughter group or to one of six feeding treatments for 6 weeks. The two feeds used were starch, with 12.52 MJ metabolizable energy (ME) and 0 kg digestible crude protein (DCP)/kg, and a high-protein feed, with 11.95 MJ ME and 0.362 kg DCP/kg. In the first week the LW × pigs were given 400 g high-protein feed/d with 0, 100, 200 or 300 g starch/d, or 200 g high-protein feed/d with 400 or 500 g starch/d. The six diets had ME:DCP ratios of between 33 and 119 MJ/kg. The diet compositions were held constant within each of the six treatments but the allowances were increased weekly on time-based linear scales to be 2.25 as great in week six as in week one. The allowances for the CM pigs were 0.75 of those for the LW ×. The calculated efficiency of protein utilization, ep, was found to be directly proportional, up to a maximum value, to the ME:DCP ratio of the diet for both breeds, as found previously for LW × male and female pigs. The overall constant of proportionality was ep = 0.0108 (SE 0.00024) ME:DCP, the value of which did not differ significantly between the two breeds. The maximum observed ep values were 0.710 (SE 0.014) and 0.824 (SE 0.016) for the LW × and CM pigs respectively. It is likely that the lower maximum value for the LW x pigs was an experimental artefact due to increased feed spillage by these pigs on the two highest starch allowances used. In previous experiments the maximum value of ep was found to be 0.813 for LW × pigs, a value similar to that found here for the CM pigs. The results are consistent with the view that the two very different pig breeds have the same net efficiency in using protein and use the same rules for partitioning a scarce resource such as energy.
Dietary intake and micronutrient status of adolescents: effect of vitamin and trace element supplementation on indices of status and performance in tests of verbal and non-verbal intelligence
Authors: Southon Susan , Wright A. J. A. , Finglas P. M. , Bailey Angela L. , Loughridge Julie M. , Walker A. D.
Published: September 2005

Relationships between micronutrient intake and status, and micronutrient status and performance in tests of intelligence were investigated in a group of adolescents (13–14 years old). Dietary intakes were assessed using a 7 d weighed dietary record method, coupled with the collection of duplicate diets. Vitamin and trace mineral intakes calculated using food composition tables were compared with those obtained by direct analysis of duplicate diets. Micronutrient status was judged via a range of biochemical indices measured in blood samples taken after a 12–15 h fast. Blood samples were taken both before and after a 16-week period of vitamin and trace mineral supplementation. Individual tests of verbal and nonverbal intelligence were also performed pre- and post-supplementation. The results of this study indicate that the use of food table data may lead to substantial over- or underestimation of the intake of several micronutrients. In general, the total calculated or analysed amount of a specific micronutrient consumed did not adequately predict status, as judged by a range of biochemical indices. There were significant changes in status measurements over the 16-week study period, irrespective of supplementation, and these changes were markedly influenced by the initial status of the subject. There was no effect of supplementation on performance in tests of intelligence. However, there was a significant association between plasma ascorbic acid and initial non-verbal intelligence quotient (IQ) in the boys, and between whole blood glutathione peroxidase (EC1.11.1.9) activity and non-verbal and verbal IQ in both sexes. These findings are discussed in relation to other recent studies of the influence of micronutrient supplementation on the psychological performance of children.
Proanthocyanidins inhibit hydrolysis of leaf proteins by rumen microflora in vitro
Authors: Tanner Gregory J. , Moore Andrew E. , Larkin Philip J.
Published: September 2005

Proanthocyanidins (condensed tannins; PA) purified from the leaves of forage legumesTrifolium arvense, Lotus pedunculatus, Lotus corniculatus, Dorycnium rectum, Coronilla varia, Onobrychis viciifolia, orHedysarum coronarium, were added to soluble lucerne (Medicago sativa) leaf protein and incubated with strained rumen fluidin vitro. Fractions were collected and frozen immediately. Denatured proteins were fractionated by sodium dodecylsulphate–polyacrylamide gel electrophoresis (SDS–PAGE), stained, and relative levels were quantified by densitometry. In the absence of PA the large subunit (LSU) of ribulose bisphosphate carboxylase (EC4. 1. 1. 39) was susceptible to proteolysis by rumen microflora but the small subunit (SSU) resisted breakdown. PA purified fromOnobrychiswas added to soluble leaf protein, at PA: protein ratios between 1:1 and 1:20. The rate of proteolysis of LSU1was significantly reduced at PA: protein ratios of 1:2 and 1:1 (P< 0.001) and the rate of digestion was reduced by between 3- and 21-fold. In separate experiments PA isolated from the range of species described was added to rumen fluid to give PA: protein ratios of 1: 5. The addition of PA significantly reduced the rate of proteolysis of LSU, when compared with PA-free control. There were only small differences between PA from different species. The inhibitory effect of PA may have been due to PA binding to the dietary protein or to the rumen proteases, interfering with the action of proteases on susceptible sites within the substrate.
A non-linear compartmental model to describe forage degradation kinetics during incubation in polyester bads in the rumen
Authors: Dhanoa M.S. , France J. , Siddons R. C. , Lopez S. , Buchanan-Smith J.G.
Published: September 2005

A new model for describing forage degradation kinetics during incubation in the rumen using polyester bags is presented. Attention is given to dealing with the problem of deviations from exponential behaviour in the early stages of degradation by devising a function capable of representing exponential or sigmoidal trends. This is achieved by allowing part of the fractional degradation rate to vary with time of incubation, thus enabling responses other than those expected under simple first-order kinetics to be described. Seven sets of data consisting of 620 curves were analysed to study the performance of the new model compared with a commonly used exponential model. The proportion of significantly better fits varied from set to set. The new model deals successfully with sigmoidal behaviour and, thus, provides a means of analysing the degradation profiles of low-quality
Protein v. enzymic protein hydrolysates. Nitrogen utilization in starved rats
Authors: Boza Julio J. , Martínez-Augustin Olga , Baró Luis , Suarez M. Dolores , Gil Angel
Published: September 2005

The present study was carried out to compare the effects of four isoenergetic and isonitrogenous diets on the N utilization, total serum protein concentration and serum amino acid profile in starved rats at weaning. These diets differed only in the molecular form of two milk proteins (whey protein and casein), which were either native or partly hydrolysed. Male Wistar rats at weaning were fasted for 3 d and then refed with one of the four diets for 48 h. No differences were observed in the body weight gain, protein digestibility and total serum protein concentration between groups after the refeeding period and all the N balances were positive. N retention was higher in the two groups of rats given the protein-hydrolysate-based diets compared with those given the intact-protein-based diets. This was associated with a lower urinary N excretion in rats, given the whey-protein-hydrolysate and the casein-hydrolysate diets. Despite this fact, the serum amino acid pattern of rats given the hydrolysed protein diet was very similar to that of those given the corresponding native protein diet. In conclusion, we have proved that enzymic hydrolysates from milk proteins have equivalent effects to native proteins in recovery after starvation in rats at weaning, on N absorption, total serum protein concentration and serum amino acid profile, and even give a higher N retention. We did not observe any harmful effect in using protein hydrolysates instead of native proteins.