bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of energy source and tryptophan on the rate of protein synthesis and on hormones of the entero-insular axis in the piglet
Authors: Ponter A. A. , Cortamira N. O. , Seve B. , Salter D. N. , Morgan L. M.
Published: June 2005

The present experiment was designed to study the influence of dietary energy source (fat or carbohydrate) and tryptophan (TRP) on protein synthesis and plasma insulin concentrations in the piglet. Six dietary regimens, based on either a high-fat (F) or a high-carbohydrate (C) diet with three levels of TRP (deficient, 1; adequate, 2; excess, 3), were used. Fractional protein synthesis rate (ks; % per d) was measured in the liver,Longissimus dorsi(LD),Semitendinosus(ST), skin, femur, brain, pancreas, stomach, mucosa of the duodenum and jejunum, and the whole body, using a‘flooding dose’of3H-phenylalanine. Mean integrated insulin, gastric inhibitory polypeptide (GIP) and glucose concentrations were higher after the C diets compared with the F diets, TRP supplementation globally augmentedkslinearly in the liver, ST, skin and whole body, while it had quadratic effects in the LD (kshighest in the TRP-adequate diet groups) and jejunal mucosa (kslowest in the TRP-adequate diet groups). Pancreatickswas increased by TRP addition up to a plateau.kswas highest after the F diets in the digestive tissues while in the skin and LDkswas highest after the C diets. Fasting concentrations of gluconeogenic amino acids were lower (and urea higher) with the F than the C diets, suggesting their use as precursors for glucose synthesis. In conclusion, we have confirmed the depressive effects of TRP deficiency onks, RNA activity and growth. We could not establish a relationship between plasma insulin and muscleks. This may be related to the way in which we manipulated plasma insulin concentrations.
Nutrition education of young women
Authors: Fine Gill A. , Conning D. M. , Firmin Cella , De Looy Anne E. , Losowsky M. S. , Richards I. D. G. , Webster John
Published: June 2005

White women aged 25–34 years (n264) from the lower socio-economic classes (C2, D and E) were classified according to their motivation in respect of health and their educational attainment and arithmetical ability. They were randomly allocated to three groups. One group (test) was given a course in basic nutrition consisting of a video and booklet, each embellished with motivational material. Those classed as of low ability also received the training material in simplified format. A second group (control) received a video and booklet with no motivational or simplified materials. The third group (baseline) received no tuition and represented a control of publicly available information during the period of the experiment. The participants answered a series of questions by administered questionnaire to measure their nutritional knowledge before and one week after they viewed the video programme. All participants achieved significantly higher scores at the second questionnaire. The test and control groups achieved significantly higher scores than the baseline group but there was no significant difference between the test and control groups. The presentation of motivational or simplified materials had no significant effect on learning ability though those classified as more highly motivated and of higher ability achieved higher scores at each questionnaire. The results indicate that young adult females can be taught basic nutrition irrespective of their motivation or ability.
Maternal essential fatty acid patterns during normal pregnancy and their relationship to the neonatal essential fatty acid status
Authors: Al Monique D. M. , Van Houwelingen Adriana C. , Kester Arnold D.M. , Hasaart Tom H.M. , De Jong AndrÉ E. P. , Hornstra Gerard
Published: June 2005

Although essential fatty acids (EFA) and their longer chain, more unsaturated derivatives play a major role during pregnancy, hardly any information is available with respect to the course of the maternal EFA status during an uncomplicated pregnancy and its relationship to the neonatal EFA status. Therefore, a longitudinal study was started in which 110 pregnant women gave repeated blood samples from the 10th week of gestation until delivery. After birth a blood sample from the umbilical vein and a maternal venous blood sample were collected as well, and 6 months after delivery a final blood sample from the mother was taken. The absolute (mg/l) and relative (% total fatty acids) amounts of the fatty acids in plasma phospholipids were determined. The total amounts of fatty acids increased significantly during pregnancy. This pattern was similar for the individual fatty acids and fatty acid families. The relative amount of linoleic acid (18:2n−6) did not change during pregnancy, whereas the relative amount of arachidonic acid (20:4n−6) decreased. Despite maternal mobilization of docosahexaenoic acid (22:6n−3, DHA), suggested by a temporary increase in the DHA status until 18 weeks gestation, the DHA status steadily declined thereafter. This pattern was associated with a progressive increase in the DHA deficiency index in maternal blood throughout pregnancy and resulted in a sub-optimal neonatal DHA status. The overall maternal EFA status also declined steadily during pregnancy. Therefore, the question arises whether the mother, under the prevailing dietary conditions, is able to meet the high fetal requirement for EFA.
Effect of dietary protein concentration on responses toEscherichia coliendotoxin in broiler chickens
Authors: Takahashi Kazuaki , Yodogawa Shinichi , Akiba Yukio , Tamura Keiji
Published: June 2005

The effect of dietary protein concentration on stress responses against injection ofEscherichia colilipopolysaccharide (LPS) was studied in male broiler chickens. Chickens (7 d of age) were fed on a 100 (low-protein; LP) or 300 g protein/kg (high-protein; HP) diet for 2 weeks. LPS was injected intraperitoneally every 2 d during the final 6 d, or once 16 h before the end of the experiment, at a concentration of 900 μg/chick. The LPS injection did not affect body-weight gain, feed intake, gain:intake ratio, or plasma Fe concentration. The single injection of LPS reduced plasma Zn concentration, but the repeated injections did not. Feeding the HP diet increased the response of plasma Zn concentration to the single injection of LPS. Plasma albumin concentration was reduced by LPS injection. Feeding the HP diet resulted in a higher plasma α 1-acid glycoprotein (AGP) concentration than feeding the LP diet, in chicks untreated with LPS. An increase in plasma AGP concentration observed after LPS injection in chicks fed on the LP diet was greater than that seen in chicks fed on the HP diet. No significant changes in plasma AGP concentration in response to repeated injections of LPS were observed in chicks fed on the HP diet. Plasma interleukin-1 (IL-l)-like activity was greater in chicks fed on the LP diet than in those fed on the HP diet, when LPS was injected. The response of plasma IL-1-like activity to the single injection of LPS in chicks fed on the LP diet was the greatest among the treatment groups. These results suggest that acute-phase responses to LPS injection are much greater in chicks fed on a LP diet than in those fed on a HP diet, and multiple injection of LPS weakens the responses.
Dietary factors affecting the maximum feed intake and the body composition of pre-ruminant kid goats of the Granadina breed
Authors: Sampelayo M. R. Sanz , Allegretti L. , Mariscal I. Ruiz , Extremera F. Gil , Boza J.
Published: June 2005

An experiment was carried out with kid goats of the Granadina breed to identify the dietary factors affecting voluntary feed intake of the kid goat and those that additively could determine its body composition. The animals used were from birth to 61 d of age, fed ad lib. on different milk replacers containing 200, 240 and 280 g crude protein/kg DM and 200, 240 and 280 g fat/kg DM, thus giving nine dietary treatments. The utilization of the milk replacers and the animals' body composition were determined by balance and slaughter trials. There were significant positive effects of protein concentration of the milk replacers on component digestibilities, energy metabolizability, feed intake, empty-body weights, empty-body composition and protein and fat retention. The concentration of fat in the milk replacers also had a significant positive effect on the digestible and metabolizable energy concentration of the diets and on fat retention. The relationships existing between feed intake and diet composition (concentration of digestible protein, metabolizable energy and digestible protein:metabolizable energy ratio) as well as between empty-body composition or protein and fat retention and diet composition, were examined. From these it was deduced that feed intake was significantly influenced by the digestible protein concentration of the diets. The higher the digestible protein concentration the higher the feed intake up to a maximum digestible protein concentration value. As the digestible protein concentration of the diets was the dietary factor which significantly influenced feed intake, this also significantly influenced the body composition and the protein and fat retention. The protein concentration of the feed at which metabolizable energy intake in these animals would be greatest was estimated to be 347 g/kg DM.
Intake, digestion and small intestinal protein availability in sheep in relation to ammoniation of wheat straw with or without protein supplementation
Authors: Oosting S. J. , Van Bruchem J. , Chen X. B.
Published: June 2005

The effects of ammoniation of wheat straw with or without supplementation of protein sources of either high (casein) or relatively low (potato protein) rumen degradability on intake and digestion were studied with four sheep in a 4 × 4 Latin square design. Rations offered were: (1) untreated wheat straw (UWS), (2) ammoniated wheat straw (AWS), (3) AWS supplemented with 3·2 g casein/kg live weight (W)0·75per d (AWSC) and (4) AWS supplemented with 3·9 g potato protein/kg W0·75per d (AWSP). Straw was offeredad lib.and all rations were supplemented with sugarbeet pulp and a mineral mixture. NH3treatment increased intake and digestion. Supplementation of AWS with potato protein increased total digestible organic matter intake (DOMI) compared with AWS whereas supplementation with casein did not affect total DOMI. Protein supplementation of AWS significantly reduced rumen digestion of cellulose, and when the supplementation was with casein it reduced rumen digestion of neutral-detergent fibre and hemicellulose also. This lower rumen digestion was compensated by a higher proportion of digestion occurring in the hindgut for hemicellulose (P<0·05 for AWSC, P>0·05 for AWSP), but not for cellulose. Across all rations, rumen fluid volume increased with increasing cell-wall intake. The efficiencies of microbial protein synthesis were (average of three different methods of estimation) 23·3, 26·2, 34·8 and 31·7gN/kg apparently-rumen-degraded organic matter for UWS, AWS, AWSC and AWSP respectively. The difference between UWS and AWS was not significant, but values for AWSC and AWSP were significantly higher than that for AWS. The rumen digestion of feed aimno acid-N (AA-N) was significantly higher for AWSC than for the other rations. The apparent small-intestinal digestion of AA-N and N was significantly higher for AWSP than for the other rations. The true small-intestinal digestion values were 0·86, 0·84 and 0·68 for AA-N, N and non-protein-N respectively. Heal endogenous losses of AA-N were approximately 6 mg/g duodenal non-protein dry-matter flow. Linear relationships were observed between DOMI and N balance and truly absorbed AA-N, indicating that DOMI could have been limited by small-intestinal amino acid availability. Regression of N balancev. truly absorbed AA-N resulted in an estimate of net efficiency of utilization of truly absorbed AA-N of 0·54.
Physical activity, body composition and bone density in ballet dancers
Authors: Van Marken Lichtenbelt Wouter D. , Fogelholm Mikael , Ottenheijm Ramon , Westerterp Klaas R.
Published: June 2005

The main purpose of the present study was to examine factors that affect bone mineral density (BMD) in female ballet dancers. Training history, Ca intake, body composition, total body BMD (TBMD) and site-specific BMD, and bone mineral content were described in twenty-four female ballet dancers (mean age 22·6 (SD 4·5) years). Training history was determined by questionnaires, Ca intake by 7 d dietary record, BMD and bone mineral content by dual-energy X-ray absorptiometry (DXA), total body water by2H dilution, extracellular water by bromide dilution, body fat by underwater weighing (UWW; two-component model), DXA, and the four-component (4C) model. Dancers had a significantly lower body mass index (BMI 18·9 (SD 1·0) kg/m2) than controls (21·3 (SD 19) kg/m2), with significantly lower percentage body fat (17·4 (SD 3·9)v. 24·4 (SD 5·1)) but comparable fat-free mass. Mean TBMD (1·147 (SD 0 ·069) g/cm2) was significantly higher (6 %) compared with that of a reference population. These high values could be attributed to the high BMD of legs and pelvis, the weight-bearing sites of the dancer's body. No relationship was found between age, start of ballet classes, period (years) of dancing, Ca intake, and BMD (total and site-specific). However, TBMD was positively related to BMI, and negatively related to the age of menarche. BMD of the legs was significantly related to daily period (h) of training. Depending on the method used the percentage body fat ranged from 16·4 (by DXA) to 18·3 by the 4C model. These differences were significantly related to the TBMD. Percentage body fat by the different methods was not significantly different, except for DXA and 4C model. The present study showed that, despite the factors that have a negative effect on BMD, such as low body mass and late menarche, BMD in female ballet dancers was relatively high. These high values were probably caused by high levels of weight-bearing physical activity.
Replacement of dietary saturated fat with monounsaturated fat: effect on atherogenesis in cholesterol-fed rabbits clamped at the same plasma cholesterol level
Authors: Nielsen Lars B. , Leth-Espensen Per , Nordestgaard Børge G. , Forged Eline , Kjeldsen Knud , Stender Steen
Published: June 2005

The aim was to compare the effect on atherogenesis of dietary monounsaturated and saturated fatty acids in cholesterol-clamped rabbits. To obtain an average plasma cholesterol concentration of 20 mmol/l in each rabbit during the 13-week cholesterol-feeding period, dietary cholesterol was adjusted weekly. The amount of fat fed daily was 10 g per rabbit in Expts A (n23), C (n36), and D (n58) and 5 g per rabbit in Expt B (n24). The source of monounsaturated fatty acids was olive oil in all four experiments. The source of saturated fatty acids was butter in Expt A, lard in Expt B, coconut oil in Expt C, and butter or lard in Expt D. Generally, olive oil-fed groups received more cholesterol and tended to have more cholesterol in VLDL and less in LDL compared with groups receiving saturated fat. Analysis of variance of the combined results of all four experiments showed that, in comparison with saturated fat, olive oil lowered aortic cholesterol by 13 (−9–30, 95% confidence interval) % in the aortic arch, and by 10 (−10–26) % in the thoracic aorta, which was not significant. In the comparison with olive oil, no differences in effects on aortic cholesterol content were detected between butter, lard and coconut oil. These findings do not support the view that replacement of dietary saturated fat with olive oil has a major impact on the development of atherosclerosis in addition to that accounted for by changes in plasma cholesterol levels.
The growth and nutritional status of healthy Asian children aged 4–40 months living in Sheffield
Authors: Duggan M. B. , Harbottle L.
Published: June 2005

Detailed anthropometric measurements were made on 169 healthy children aged between 4 and 40 months during a comprehensive study of the diet and nutritional status of Asian children (of Pakistani and Bangladeshi origin) living in Sheffield. These measurements were used to describe the growth profile of these apparently healthy children and to compare this with both international and UK reference data. The distribution of values for most anthropometric measurements was close to the UK reference data although both boys and girls tended to be slight of build, and girls tended to have relatively smaller head circumferences. Nevertheless, it was concluded that their growth and nutritional status over this age range can be evaluated using standard (UK) growth charts
Effect of food composition on vitamin K absorption in human volunteers
Authors: Gijsbers Birgit L. M. G. , Jie Kon-Siong G. , Vermeer Cees
Published: June 2005

The human vitamin K requirement is not known precisely, but the minimal requirement is often assumed to be between 0·5 and 1 x 10−6g/kg body weight. In the present study we addressed the question to what extent circulating vitamin K concentrations are influenced by the form in which the vitamer is consumed. The experimental group consisted of five healthy volunteers who received phylloquinone after an overnight fast. On the first day of three successive weeks the participants consumed 1 mg (2·2 µmol) phylloquinone, either in the form of a pharmaceutical preparation (Konakion®), or in the form of spinach + butter, or as spinach without added fat. Circulating phylloquinone levels after spinach with and without butter were substantially lower (7·5- and 24·3-fold respectively) than those after taking the pharmaceutical concentrate. Moreover, the absorption of phylloquinone from the vegetables was 1·5 times slower than from Konakion. In a second experiment in the same five volunteers it was shown that relatively high amounts of menaquinone-4 enter the circulation after the consumption of butter enriched with this vitamer. It is concluded that the bioavailability of membrane-bound phylloquinone is extremely poor and may depend on other food components, notably fat. The bioavailability of dietary vitamin K (phylloquinone+menaquinones) is lower than generally assumed, and depends on the form in which the vitamin is ingested. These new insights may lead to a revision of the recommended daily intake for vitamin K.
Flavin metabolism during respiratory infection in mice
Authors: Brijlal Sangeetha , Lakshmi A. V , Bamji Mahtab S. , Suresh P.
Published: June 2005

Previous control studies carried out in children showed that respiratory infection alters riboflavin metabolism and leads to excessive urinary losses of the vitamin. In order to understand the nature of biochemical changes in riboflavin metabolism during respiratory infection, a study was carried out using the mouse as the experimental model, andKlebsiella pneumonjueas the infective organism. Mice were fed on either a low(0·5 mg/kg)- or high(13·3 mg/kg)-riboflavin semi-synthetic diet. Infection resulted in a 5–6-fold higher excretion of riboflavin in the urine of mice fed on the low-riboflavin diet. Higher erythrocyte FAD levels and lower liver FAD levels were also observed during infection. Of the four enzymes involved in the synthesis and breakdownof the flavin coenzymes studied, the activity of hepatic flavokinase (ATP: riboflavin 5'-phosphotransferase;EC2.7.1.26) was significantly lower, and that of FAD synthetase (ATP: FMN adenylyltransferase;EC2.7.7.2) was higher during riboflavin restriction and infection. The activity of FMN (acid) phosphatase (EC3.1.3.2) was unchanged, whereas FAD (nucleotide) pyrophosphatase (EC3.6.1.9) activity was significantly higher both with the low-riboflavin diet and during infection. Thyroid hormone is known to modulate flavokinase activity and, hence, thyroid status was assessed. Plasma triiodothyronine (T3) levels were not affected, but thyroxine levels were lower in the mice fed on the low-riboflavin diet. However, plasma T3 was significantly lower during infection, suggesting a mechanistic role for the hormone in the reduction of flavokinase activity.
Conversion of [15N]ammonia into urea and amino acids in humans and the effect of nutritional status
Authors: Weijs P. J. M. , Calder A. G. , Milne E. , Lobley G. E.
Published: June 2005

Hepatic NH3detoxification by ureagenesis requires an input of aspartate-N, originating either from amino acid-N or NH3-N. The relative importance of these two routes may depend on the nutritional state. To test this, four volunteers were given a liquid diet for 2 d and then on day 3 were either fed every 20 min or fasted. Doses of15NH4Cl were taken orally every 20 min for 6 h (total 1.5 g) and blood was sampled hourly. Urea-N elimination under fasted conditions was only 0.75 of that for the fed state. Considering the increase in body urea pool during feeding, ureagenesis during fasting was probably closer to 0.6 of that during feeding. Since the [14N15N] urea enrichment was not different between the fed and fasted states, the proportion of the15NH3dose converted to urea during fasting was also 0.6 of that during the fed condition. No change in [14N15N] urea and [amide-15N] glutamine enrichment suggested that NH3enrichment was also not affected by nutritional state. Enrichment of [14N15N] urea was approximately 0.05 that of [14N15N] urea which indicates that15NH3can also enter the aspartate route, the importance of which is yet unknown. Both [15N15] urea and [amino-15N]glutamine enrichment in the fasted state were approximately 1.7 times that in the fed state, indicating increased labelling of precursors and/or increased NH3flux through the aspartate route. Glutamate, valine, leucine and isoleucine showed comparable increases in enrichment during fasting. Arginine enrichment was unaltered by nutritional state, but was lower than [14N15N] urea, indicating incomplete equilibration with the arginine pool in periportal hepatocytes. The present study indicates that hepatic NH3detoxification may use the aspartate route, gaining importance in the fasted state. The majority of urea was supplied with only one N atom from NH3, thus provision of the other may have consequences for alternative substrates, in particular amino acids.
Organ-selective growth in the offspring of protein-restricted mothers
Authors: Desai Mina , Crowther Nigel J. , Lucas Alan , Nicholas Hales C.
Published: June 2005

Recent epidemiological studies in people whose birth weights were recorded many years ago suggest links between impaired growth during early life and the development of diseases, including diabetes, much later in life. The long-term effects of retarded early growth are proposed to result from malnutrition at critical periods of fetal or infant development leading to reduction in the growth of organs and permanent changes in their metabolism or structure, or both. In order to investigate this, a rat model was established which involved feeding either a diet containing 200 g protein/kg or an isoenergetic diet containing 80 g protein/kg to pregnant and lactating rats. In addition, cross-fostering techniques were employed which allowed a separate evaluation of the prenatal or the postnatal periods. The offspring were studied at 21 d of age or were weaned onto a normal laboratory chow and studied at 11 months of age. The 80g protein/kg diet during pregnancy did not affect the overall reproductive performance although more subtle differences were evident. Permanent growth retardation was evident in offspring subjected to maternal protein restriction during the postnatal period. At 21 d of age the offspring of protein-restricted mothers exhibited selective changes in organ growth: compared with the body weight, the lung and brain experienced a smaller decrease in weight; the heart, kidney and thymus decreased proportionately; whereas, the pancreas, spleen, muscle and liver showed a greater reduction in weight. In older animals the muscle weight was lower in the male rats and the relative weight ofpancreas was increased in the female rats.
Influence of feeding artificial-formula milks containing docosahexaenoic and arachidonic acids on the postnatal long-chain polyunsaturated fatty acid status of healthy preterm infants
Authors: Foreman-Van Drongelen Magritha M. H. P. , Van Houwelingen Adriana C. , Kester Arnold D. M. , Blanco Carlos E. , Hasaart Tom H. M. , Hornstra Gerard
Published: June 2005

In view of the importance of long-chain polyunsaturated fatty acids (LCP) for growth and development of fetal and infant neural tissue, the influence of the dietaryn-3 andn-6 LCP intake onthe LCP status of forty-three preterm infants (birth weight<1800 g) was studied. Thirty-one formula-fed infants were randomly assigned to receive a conventional formula lacking LCP (n 16), or an 22:6n-3-and 20:4n-6-enriched formula (n15); twelve infants received their own mother's breast milk. Fatty acid compositions of plasma and erythrocyte (RBC) phospholipids (PL) were determined in umbilical venous blood, in weekly postnatal samples until day 35 of life and, for the formula-fed infants, at 3 months of corrected age. Both in plasma (P < 0·001) and RBC (P < 0.01) PLY, the changes with time until day 35 for 22: 6n-3 and 20:4n-6 in the two groups of formula-fed infants were significantly different, with higher values, comparable with those of human-milk-fed infants, in the LCP-enriched-formula group. At 3 months of corrected age, differences between the two formula-fed groups were even more pronounced. In conclusion, adding 22: 6n-3 and 20:4n-6 to artificial formulas in balanced ratios and in amounts similar to those found in preterm human milk raises both the 22:6n-3 and the 20:4n-6 status of formula-fed preterm infants to values found for human-milk-fed preterm infants. Additional studies are necessary to evaluate the potentially favourable effects of this combined addition on the neurodevelopmental outcome of preterm infants.
The effects of excessive amounts of protein on lysine utilization in growing pigs
Authors: Langer Stefan , Fuller Malcolm F.
Published: June 2005

Two experiments were conducted to investigate whether the utilization of lysine in growing pigs is affected by the level of excess protein in the diet. Nine lysine-deficient diets containing 100,200 or 300g crude protein/kg and between 1·2 and 6·8 g ileal digestible lysine/kg were prepared. In the first experiment the apparent ileal digestibility of lysine in three of the nine diets was determined using pigs with simple T-cannulasand Cr2O3, as an indigestible marker. Ileal digestibility of lysine in the other diets was calculated by interpolation. In the second experiment N retention, as a measure of lysine utilization, was determined in all nine diets using growing pigs over the weight range 30–50 kg. The effect of excess protein on lysine utilization was assessed by comparing the regression of N retentionv. lysine (ileal digestible) intake at the three levels of protein. Increasing ileal digestible lysine in the diets resulted in a linear increase in N retention with all three protein levels and there was no significant difference amongst the three regressions, indicating that lysine utilization was not affected by the level of protein.Therefore, all data were pooled together to calculate a single regression for all treatments.An increase of 1·0 g ileal digestible lysine led to an increase of 1·43 g N or 8·96 g protein (N x 6·25) retained. Assuming a lysine concentration in the retained body protein of 65–72 mg/g, lysine was utilized with an efficiency of 0·58–0·65
Vitamin A and carotenoid status in rural China
Authors: Wang Guangya , Brun Thierry A. , Geissler Catherine A. , Parpia Banoo , Root Martin , Li Ming , Campbell T. Colin , Chen Junshi
Published: June 2005

Vitamin A status of 260 groups of twenty-five males or twenty-five females, aged 35–64 years, surveyed in twenty-four provinces of the People's Republic of China, was assessed by measuring plasma retinol, retinol-binding protein and β-carotene concentrations. Direct measurements of food intake over a 3 d period and questionnaire data on the frequency of consumption of vegetables, fruit, animal products and other dietary items were also used. Vitamin A status appeared to be low only in specific counties but in general was satisfactory or only marginally deficient. Plasma harotene levels were strikingly low in comparison with Western levels despite generous vegetable consumption suggwg that intake of vitamin A precursors may have been adequate but not abundant enough to maintain high circulating plasma levels of β-carotene. Plasma β-carotene, for both males and females, was significantly correlated with the frequency of consumption of green vegetables. Plasma retinol, for males, was highly correlated with meat, fish, oil and alcohol consumption expresPed both in quantity or frequency of consumption. Higher levels of plasma retinol, together with lower levels of plasma β-carotene in males compared with females, suggest that men consume more animal products or may have higher retinol requirements and therefore a higher rate of conversion of β-carotene to retinol.
Application of agar-fill method to estimate compartment capacity of gastrointestinal tract in Syrian hamsters (Mesocricetus auretus)
Authors: Sasaki Osamu , Shinohara Hisashi , Yamagishi Toshihiro , Nishida Akira , Mizuma Yutaka
Published: June 2005

In the present study we have developed the agar-fill method for the measurement of gastrointestinal-tract capacity (GTC) to replace the in vitro water-fill method. This would estimate GTC without using complex equipment and techniques, and can be applied to the measurement of GTC for small laboratory animals. We attempted to confirm the efficiency of the agar-fill method by investigating the relationship between dietary neutral-detergent fibre (NDF) content and GTC. The digestion trials were carried out using the Syrian hamster (Mesocricefus auretus). The trials were conducted using both sexes, two age-groups and three levels of dietary NDF with a cross-classified design. The size of each gastrointestinal organ was determined as tissue weight(TW)and GTC. The DM intake, digestible DM intake, DM digestibility, NDF digestibfity, aciddetergent fibre(ADF) digestibfity and digesta transit time were also measured. GTC increased with increasing NDF content of the diets. TW responded similarly to increasing NDF content, but the response was smaller than that of GTC. DM digestibility decreased with increasing NDF content of the diet. The digestible DM intake did not decrease with increasing NDF because DM intake increased with NDF content. Digesta transit time was not shorter of the high-NDF-diet group but DM intake increased with increasing NDF content. NDF digestibility did not differ significantly between low- and medium-NDF diets. ADF digestibility was low in the low-NDF-diet group.The digestion characteristics were highly correlated with TW and GTC, except for TW of small intestine. These correlations were higher with GTC than with TW. The results of the present study confirm previous findings suggesting that the agar-fill method is a useful means of estimating GTC for small laboratory animals.
Role of thyroid hormones in early postnatal development of skeletal muscle and its implications for undernutrition
Authors: Harrison A. P. , Tivey D. R. , Clausen T. , Duchamp C. , Dauncey M. J.
Published: June 2005

Energy intake profoundly influences many endocrine axes which in turn play a central role in development. The specific influence of a short period of mild hypothyroidism, similar to that induced by undernutrition, in regulating muscle development has been assessed in a large mammal during early postnatal life. Hypothyroidism was induced by providing methimazole and iopanoic acid in the feed of piglets between 4 and 14 d of age, and controls were pair-fed to the energy intake of their hypothyroid littermates. Thyroid status was evaluated, and myofibre differentiation and cation pump concentrations were then assessed in the following functionally distinct muscles:longissimus dorsi(l. dorsi),soleusandrhomboideus. Reductions in plasma concentrations of thyroxine (T4; 32%,P< O·Ol), triiodothyronine (T3;48%,P< 0·001), free T3, (58%,P< 0·001)and hepatic 5'-monodeiodinase (EC1.11.1.8) activity (74%,P< 0·001) occurred with treatment. Small, although significant, increases in the proportion of type I slow-twitch oxidative fibres occurred with mild hypothyroidism, inl. dorsi(2%,P< 0·01) andsoleus(7%,P< 0·01). Nuclear T3-receptor concentration inl. dorsiof hypothyroid animals compared with controls increased by 46% (P< 0·001), a response that may represent a homeostatic mechanism making muscle more sensitive to low levels of circulating thyroid hormones. Nevertheless, Na+, K+-ATPase (EC3.6.1.37) concentration was reduced by 15–16% in all muscles (l.dorsiP< 0·05,soleusP< 0·001,rhomboideusP< 0·05), and Ca2+-ATPase (EC3.6.1.38) concentration was significantly reduced in the two slow-twitch muscles: by 22% inrhomboideus(P< 0·001) and 23% insoleus(P< 0·05). It is concluded that during early postnatal development of large mammals a period of mild hypothyroidism, comparable with that found during undernutrition, induces changes in myofibre differentiation and a down-regulation of cation pumps in skeletal muscle. Such changes would result in slowness of movement and muscle weakness, and also reduce ATP hydrolysis with a concomitant improvement in energetic efficiency.
Cytokinetic and structural responses of the rat small intestine to riboflavin depletion
Authors: Williams E. A. , Rumsey R. D. E. , Powers H. J.
Published: June 2005

The impaired absorption and metabolism of Fe seen in riboflavin defiaency is attributed, at least in part, to a hyperproliferative response in the small intestine, associated with an altered morphology. Studies were conducted in female weanling Wistar rats to explore further the effect of riboflavin deficiency on the cytokinetics and structure of the small intestine. Feeding a riboflavin-deficient diet for 8 weeks from weaning resulted in a significantly lower villus number, a significant increase in villus length and an increased rate of transit of enterocytes along the villi, compared with weight-matched controls. A second experiment focused on the 3 weeks after weaning and showed that riboflavin deficiency inhibits the increase in villus number observed in control animals over this period. We suggest that riboflavin deficiency induced at weaning impairs the normal increase in villus number and that prolonged deficiency leads to an adaptive increase in length of villi and depth of crypts.
Dietary fibres reduce blood pressure, serum total cholesterol and platelet aggregation in rats
Authors: Bagger M. , Andersen O. , Nielsen J.B. , Ryttig K.R.
Published: June 2005

The effects of dietary fat and dietary fibres on blood pressure, serum lipids and platelet aggregation in spontaneously hypertensive and Wistar-Kyoto rats have been investigated. The systolic and diastolic blood pressure values were increased with increasing amounts of dietary fat and normalized by dietary fibre supplementation. The greatest reduction in blood pressure was obtained by a combination of reduced dietary fat and supplementary dietary fibre. Addition of dietary fibre when the amount of dietary fat was high or reduction of dietary fat when the amount of dietary fibre was low gave a smaller effect. In both rat strains the decreases in systolic and diastolic blood pressure values after reducing dietary fat and/or increasing dietary fibre were about 10-15 mmHg. Serum total cholesterol and serum HDL-cholesterol concentrations were reduced by reduction of dietary fat or a combination of dietary fat reduction and dietary fibre addition. A combination of dietary fat reduction and dietary fibre addition was the most effective dietary change for reducing serum triacylglycerol concentration and platelet aggregation. The present study demonstrates that in this experimental model it is possible to reduce risk indicators of coronary heart disease significantly by changing dietary habits.
Dietary sources of calcium and the contribution of flour fortification to total calcium intakein the diets of Northumbrian adolescents
Authors: Moynihan Paula , Adamson Ashley , Rugg Andrew , Appleton David , Butler Timothy
Published: June 2005

Abstract Increased Ca intake by adolescents is desirable. In order to achieve this, information on the current dietary sources of Ca by this age group is essential to enable change to build on existing habits. This paper addresses two issues: first, the dietary sources of Ca for adolescents are reported and, second, the importance of fortification of flour with Ca to present-day Ca intakes was determined. In 1990 the diets of 379 children aged 12 years were assessed using the 3 d dietary diary and interview method. Computerized food tables were used to calculate the contributions of different food groups to total Ca intake. The Ca content of eachfood was subdivided into naturally occurring Ca and Ca from fortification, and data were analysed to give the daily intake of each. The four most important sources of Ca were milk (25%), beverages (12%), puddings (10%) and bread (9%). Fortification of flour accounted for 13% of total Ca intake. When the contribution of fortification was removed, the proportion of subjects with intakes of Ca below the lower reference nutrient intake (Department of Health, 1991) increased more than fourfold, to 10% of girls and 12% of boys. Milk is contributing less to Ca intake than in the past and increased consumption should be encouraged. Ca fortification of flour remains an important source of Ca. Therefore, unless dietary habits are modified to ensure adequate Ca from other sources, increased consumption of unfortified products from outside the UK will lead to a further reduction in Ca intake.
Prediction of the chemical composition of lamb carcasses from multi-frequency impedance data
Authors: Hegarty R. S. , McPhee M. J. , Oddy V. H. , Thomas B. J. , Ward L. C.
Published: June 2005

Multi-frequency bioimpedance analysis (MFBIA) was used to determine the impedance, reactance and resistance of 103 lamb carcasses (17·1–34·2 kg) immediately after slaughter and evisceration. Carcasses were halved, frozen and one half subsequently homogenized and analysed for water, crude protein and fat content. Three measures of carcass length were obtained. Diagonal length between the electrodes (right side biceps femoris to left side of neck) explained a greater proportion of the variance in water mass than did estimates of spinal length and was selected for use in the index L2/Z to predict the mass of chemical components in the carcass. Use of impedance (Z) measured at the characteristic frequency (Zc) instead of 50 kHz (Z50) did not improve the power of the model to predict the mass of water, protein or fat in the carcass. While L2/Z50 explained a significant proportion of variation in the masses of body water (r2 0·64), protein (r2 0.34) and fat (r20·35), its inclusion in multi-variate indices offered small or no increases in predictive capacity when hot carcass weight (HCW) and a measure of rib fat-depth (GR) were present in the model. Optimized equations were able to account for 65–90% of the variance observed in the weight of chemical components in the carcass. It is concluded that single frequency impedance data do not provide better prediction of carcass composition than can be obtained from measures of HCW and GR. Indices of intracellular water mass derived from impedance at zero frequency and the characteristic frequency explained a similar proportion of the variance in carcass protein mass as did the index L2/Z50.
Lipid accumulation in obese Zucker rats is reduced by inclusion of raw kidney bean (Phaseolus vulgaris) in the diet
Authors: Pusztai A. , Grant G. , Buchan W. C. , Bardocz S. , de Carvalho A. F. F. U. , Ewen S. W. B.
Published: June 2005

The effects of inclusion of different levels of raw kidney bean (Phaseolus vulgaris) of high lectin content (27 g/kg meal) in a high-quality (lactalbumin) control diet were tested in nutritional trials on the growth and metabolism of obese Zucker (fafa) rats and their lean littermates in comparison with pair-fed controls. All diets contained 100 g total protein/kg and either 50 g lipids/kg (low fat) or 150 g lipids/kg (moderate fat). The growth of both obese and lean rats on bean diets was retarded by the daily bean intake in a dose-dependent manner. However, most of this was because bean-fed rats contained less body fat than the controls after 10 d. Thus, after feeding low-fat diets containing up to 130 g kidney bean/kg (lectin intake ≤ 0·2 g/kg body weight (BW) per d) in both 10 d and 70 d trials, the bodies of obese rats contained less fat but not protein than their pair-fed controls. Moreover, by increasing the lipid content of the diet to 150 g/kg, the level of bean inclusion could be increased to 280 g/kg (lectin intake ≥ 0·4 g/kg BW per d) without loss of body protein and skeletal muscle. Although these rats contained more body fat than those which were fed on low-fat diets, their weight reduction could be accounted for exclusively by reduced lipid content. In contrast, significant body protein loss occurred when the same diet of high lectin content was fed to lean littermates. Plasma insulin levels were significantly depressed in the obese Zucker rats on bean diets but the pancreas was not significantly enlarged nor its insulin content changed in 10 d trials. However, significant pancreatic growth occurred on long-term (70 d) bean feeding compared with pair-fed controls. The results suggest that, in addition to animal nutrition, it may also be possible to use the bean lectin as a dietary adjunct or therapeutic agent to stimulate gut function and ameliorate obesity if a safe and effective dose-range can be established for human subjects.
Metabolic and cardiovascular responses to liquid and solid test meals
Authors: Habas M. Elmukhtar , Macdonald I. A.
Published: June 2005

There is indirect evidence from previous studies that the physiological responses to a liquid test meal may differ from those seen after consumption of a solid meal. The aim of the present study was to determine the metabolic and cardiovascular responses to isoenergetic high-carbohydrate mixed nutrient liquid or solid test meals, providing 2.1 MJ (approximately 70% of which was from carbohydrate), in eight healthy men following an overnight fast. Metabolic rate increased significantly after both meals (P < 0.0001, time effect), but the increase was significantly greater after the solid than after the liquid test meal (0.40 (SE 0.14), 0.26 (SE 0.10) kJ/min respectively, P = 0.001). The respiratory exchange ratio increased significantly after both the liquid and solid test meals, with no significant differences between them. Forearm blood flow increased significantly after the liquid test meal (0.70 (SE 0.33) ml/100 ml per min, P < 0.0001), whilst it decreased after the solid meal (−0.28 (SE 0.16)ml/100ml per min, P< 0.0001). Heart rate increased on both occasions, but the response was significantly greater after the solid meal (P=0.02). There were no significant plasma noradrenaline responses, but there were significantly higher increases in serum insulin and blood glucose following the solid meal. Thus, the physical form of a test meal affects the physiological responses to nutrient ingestion.
Is zinc a limiting nutrient in the diets of rural pregnant Malawian women?
Authors: Huddle Janet-Marie , Gibson Rosalind S. , Cullinan Timothy R.
Published: June 2005

Pregnant women consuming plant-based diets are at risk of Zn deficiency; Zn requirements for fetal growth and maternal tissue accretion are high. Therefore we have studied, at 24 and 33 weeks gestation, the Zn status of eighty-seven pregnant rural Malawian women (mean age 22·7 years) who consume maize-based diets, using anthropometry, dietary intake data, plasma and hair Zn concentrations, and infection status via serum C-reactive protein, leucocyte count, and malaria blood smear. Of the women, 12% were stunted (height-for-age Z score < -2 SD) and 20% lost weight over the 9-week period; weight gain averaged 0·13 kg/week. Mean plasma Zn concentration declined significantly from 24 to 33 weeks (7·9 (SD 2·2)v.6·6 (SD 2·0) μmol/l;P< 0·0003). Both plasma and hair Zn values were very low; nearly 50% of the women had both plasma and hair Zn values below acceptable cut-off values. No significant differences in biochemical Zn indices existed between those who tested positive and negative for infection. Cereals (mainly maize) provided more than two-thirds of mean energy intake compared with less than 5% from flesh foods. As a result about 60% of the subjects had dietary phytate: Zn molar ratios greater than 15, and more than 35% had inadequate Zn intakes based on probability estimates and WHO basal requirements. Biochemical evidence of Zn deficiency was attributed in part to low intakes of poorly available Zn. The anthropometric, biochemical, and dietary data together indicate that Zn deficiency may be a factor limiting pregnancy outcome in rural Malawian women.
The influence of live weight, live-weight change and diet on protein synthesis in the skin and skeletal muscle in young Merino sheep
Authors: Liu S. M. , Mata G. , O'Donoghue H. , Masters D. G.
Published: June 2005

Wool growth is derived directly from protein synthesis in the skin of sheep, and is affected by the nutritional status of the animals. The present experiment examined both protein synthesis in the skin and muscle and wool growth in Merino lambs differing in live weight, intake and dietary protein source. The experiment was a 23 factorial design: twenty-four 5-month-old lambs initially weighing 33 kg (heavy) or 25 kg (light) were fed on a hay-based diet with either lupin seed or rapeseed meal as the major protein sources to maintain live weight (M) for 56 d, or were fed at 0.6M for 28 d (period 1) followed by 28 d at 1.6M (period 2). Fractional protein synthesis rates (FSR, % per d) in the skin and the m. longissimus dorsi on days 4 and 24 of period 1 and day 4 of period 2 were measured by means of a flooding dose of l-[ring-d5]phenylalanine, and wool growth on a skin patch over period 1 was also measured. The FSR ranged from 13.2 to 20.2% per d in the skin, higher than reported for other breeds, and 1.53–3.07% per d in the muscle. Sheep on the low intake (0.6M) had significant reductions in FSR, protein content (g), protein synthesis (g/d) in the skin, and wool growth (g/d). The heavy lambs had similar FSR to the light lambs, but had a higher skin protein content and total protein synthesis per unit of skin area (100 cm2) and, therefore, grew more wool. The rapeseed-meal diet increased FSR and wool growth only in the light lambs over the short term. The protein deposited in wool over period 1 was 0.185 of the total protein synthesis in the skin, regardless of live weight, intake or diet, a result similar to other breeds. With the changes in dietary intake, protein synthesis in the skin and muscle responded differentially, with nutrient partitioning at sub-maintenance in favour of wool growth but at supra-maintenance, following a nutrient restriction, in favour of weight gain in young growing sheep.