bluuebunny/crossref_metadata_2025 huggingface dataset:
The activities of some metabolic enzymes in the intestines of germ-free and conventional chicks
Authors: Palmer Maureen F. , Rolls B. A.
Published: June 2005

1. The metabolic enzymes alkaline phosphatase (EC3. 1. 3. 1), acid phosphatase (EC3. 1. 3. 2) and isocitrate dehydrogenase (EC1. 1. 1. 42) were measured in mucosal homogenates and these enzymes, together with glucose-6-phosphatase (EC3. 1. 3. 9), were measured in homogenates of isolated enterocytes from germ-free (GF) and conventional (CV) chicks which were either fed continuously until they were killed or were subjected to a 16 h fast before killing.

2. The intestine of the GF chicks was generally lighter than that of the CV controls. The activity of alkaline phosphatase was greater in the mucosal homogenates of the CV chicks compared with the GF birds, but the concentrations of acid phosphatase and isocitric dehydrogenase were not different in the two groups. In the isolated enterocytes the concentration of all enzymes expressed per mg DNA, except alkaline phosphatase, was higher in the GF chicks. Expressed per mg protein there was no significant difference in enzyme activity in the two groups.

3. Fasting caused a reduction in intestinal weight and total mucosal protein in both groups but the reduction was greater in the GF chicks compared with the CV controls. In the GF chicks, fasting caused a significant fall in acid phosphatase and isocitric dehydrogenase activities of the mucosal homogenate, whereas in the CV chicks only acid phosphatase fell to a significant extent. In the isolated enterocytes feeding caused a marked fall in protein per mg DNA in the CV chicks; fasting tended to reduce enzyme concentrations in the GF chicks but to have less effect in the CV group except for alkaline phosphatase where there was a marked rise in activity.

4. It is suggested that the difference in enzyme activities in the mucosal homogenates and isolated enterocytes might result from (a) the presence of a much greater lamina propria in the CV compared with the GF chicks and (b) the greater mitotic activity in the fed CV chicks yielding a much larger number of smaller immature cells.
High arachidonic acid levels in the cord blood of infants of mothers on vegetarian diets
Authors: Stammers J. P. , Hull D. , Abraham R. , Mcfadyen I. R.
Published: June 2005

1. Maternal and umbilical cord plasma samples were collected from forty-seven Asian women, twenty-eight lifelong vegetarians and seventeen non-vegetarians, during delivery of their babies. The concentrations and fatty acid profiles of the plasma free fatty acid and triacylglycerol fractions were determined.

2. There were no significant differences between the levels of free fatty acid and triacylglycerol in either maternal or cord plasma from vegetarian compared with non-vegetarian Asian women. The fatty acid profiles of the lipid fractions in the two groups were similar. Total plasma free fatty acid levels in the maternal circulation correlated with umbilical cord levels.

3. The levels of linoleic acid in the maternal plasma free fatty acid fraction of the Asian women were much higher than previous reports on mixed populations of European women. In the Asian women arachidonic acid concentrations in both maternal and umbilical circulations were over four times higher than those reported for women unselected for race and diet.
Nutrition and growth of suckling black bears (Ursus americanus) during their mothers' winter fast
Authors: Oftedal Olav T. , Alt Gary L. , Widdowson Elsie M. , Jakubasz Michael R.
Published: June 2005

In black bears the last 6–8 weeks of gestation and the first 10–12 weeks of lactation occur in winter while the mother is in a dormant state, and reportedly does not eat, drink, urinate or defaecate. Measurements were made of the body composition and organ weights of cubs, of the composition of milk, and of milk intake (by dilution of 2H2O), in the first 3 months after birth. Additional milk samples were collected until 10 months postpartum. Bear cubs were small at birth, only 3·7 g/kg maternal weight, and chemically immature, as indicated by the high concentration of water (840 g/kg) in their bodies. Organ weights at birth were similar to those of puppies. In the first month after birth cubs gained 22 g/d or 0·23 g/g milk consumed; the milk was high in fat (220 g/kg) and low in water (670 g/kg). About 30% of the ingested energy and 51% of the ingested N were retained in the body. Over the entire 12-week period bear cubs required about 11 kg milk, containing (kg) water 7, fat 2·5, protein 0·8 and total sugar 0·25, to achieve a 2·5 kg weight gain. The birth of immature young and the production of high-fat, low-carbohydrate milk seem to be maternal adaptations to limit the utilization of glucogenic substrates during a long fast. Isotope recycling indicates that mothers may also recover most of the water (and perhaps much of the N) exported in milk by ingesting the excreta of the cubs. Lactation represents another aspect of the profound metabolic economy of the fasting bear in its winter den.
Iron speciation at physiological pH in media containing ascorbate and oxygen
Authors: Dorey Clare , Cooper Chris , Dickson Dominic P. E. , Gibson John F. , Simpson Robert J. , Peters Timothy J.
Published: June 2005

The stability of iron ascorbate solutions was investigated, under both anaerobic and aerobic conditions, with the Fe2+ and Fe3+ indicators, respectively ferrozine and mimosine, at different pH values. The species present under the differing conditions were investigated by electron paramagnetic resonance (EPR) and Mössbauer spectroscopy and by gel-filtration chromatography. At physiological pH (6·8–7·4) iron ascorbate solutions rapidly form mononuclear chelatable Fe3+ species as reflected by indicator studies and EPR. Mössbauer spectroscopy fails to detect any Fe2+ species. EPR studies show a time-dependent decrease in rhombic Fe3+, particularly in oxygenated buffers, consistent with a conversion to polynuclear Fe. O2 uptake studies show that the conversion of Fe2+ to Fe3+ in Fe–ascorbate solutions at pH > 7·0 was accompanied by rapid O2 consumption but preceded depletion of ascorbate. Addition of high concentrations of mannitol (50–200 mM) reduces the O2 consumption and partly stabilizes the rapidly chelatable Fe form. Gel filtration studies show that the oxidation of Fe–ascorbate solutions at pH 7·4 is accompanied by an increase in the apparent relative molecular mass of the Fe, presumably due to Fe polymer formation. These studies indicate the inherent instability of Fe–ascorbate solutions above neutral pH and clearly have important implications in the use of ascorbate in studies of Fe physiology.
Relationship between long-term calcium intake and bone mineral content of children aged from birth to 5 years
Authors: Lee Warren T. K. , Leung Sophie S. F. , Lui Susan S. H. , Lau Joseph
Published: June 2005

This study evaluated Ca intake in Hong Kong Chinese children and examined the association between long-term Ca intake and bone mineral content (BMC) in children. Longitudinal dietary intake from birth to 5 years was obtained in 128 children (sixty-seven boys, sixty-one girls). Ca intakes were evaluated by dietary history and cross-checked with food frequency and 24 h recall. At age 5 years BMC was determined at the one-third distal radius of the right arm using single-photon absorptiometry. The mean Ca intake of 133 children at 5 years was 546 (SD325) mg/d. Milk was the chief source of Ca (43·5 %). From birth to 5 years, 90 % of the children had been taking milk regularly. The mean BMC and bone width (BW) of these children were 0·317 (SD0·042) g/cm and 0·756 (SD0·074) cm respectively. BMC was not correlated with current intakes of Ca, energy and protein but was positively correlated with weight (r0·57), height (r0·47) and BW (r0·66). However, cumulative Ca intake throughout the past 5 years showed significant correlation with BMC (r0·235,P= 0·0133). The significant correlation remained even after weight, height, BW, sex. and cumulative intakes of energy and protein were adjusted in multiple regression analysis (r0·248,P= 0·0107). Moreover, using principal component analysis, Ca intake during the 2nd year of life had the strongest correlation with BMC at 5 years (r0·240,P= 0·02). Ca intake of Hong Kong Chinese children was higher than the RDA of the Food and Agriculture Organization/World Health Organization (1962) and achieved 66% of the current US recommendation (National Research Council, 1989). The increased regular milk consumption reflects a significant change in dietary habits of the younger generation. Children with a habitually higher Ca intake throughout the past 5 years, particularly in the 2nd year, were found to have higher BMC.
Phosphorus studies in pigs
Authors: Ketaren P. P. , Batterham E. S. , White E. , Farrell D. J. , Milthorpe B. K.
Published: June 2005

Two experiments were conducted to determine the available P requirements of grower and grower/finisher pigs and to define the conditions for conducting a growth assay for P availability. In the first experiment, diets with four levels of calculated available P (1–4 g/kg) and four Ca: available P ratios (1·7–2·9) were used to determine the available P requirements of grower pigs. The diets were formulated by substituting the required amounts of limestone and sodium tripolyphosphate for sugar in a soya-bean meal and sugar-based diet. In addition to measuring growth responses, a range of bones were examined to determine the most suitable criteria for assessing the response to available P. There was a small quadratic response of feed intake and growth rate of the pigs to level of available P, with maximum responses occurring to approximately 3 g available P/kg (P < 0·05). There were linear depressing effects of increasing Ca:available P ratios on carcass gain and feed conversion ratio (P < 0·01) but most of these effects occurred when the ratio exceeded 2·5:1. All bone variables examined increased linearly (P < 0·05) or curvilinearly (P < 0·01) with increasing available P concentration. In general, these variables were not affected by the Ca: available P ratio. The results of the growth responses and bone development indicate that the grower pig requires approximately 3 g available P/kg. However, for availability assays, where linearity of response is needed, the dietary concentration of available P should be a maximum of approximately 2 g/kg. In the second experiment four levels of calculated available P (1–4 g/kg) with a Ca: available P ratio of 2·5:1 were used to determine the available P requirements of grower/finisher pigs from 20 to 90 kg live weight. At 50 kg live weight the dietary available P concentration for half the pigs fed at 2, 3 and 4 g available P/kg was reduced to 1, 2 and 3 g/kg respectively. The pigs were fed ad lib. and growth performance, bone characteristics, P retention and ash concentration in the empty body were taken as response criteria to assess P adequacy. Among the variables tested, the ash concentration in the radius/ulna bone and P and ash concentrations in the empty body appeared to be more responsive than other variables to the changes in dietary P levels. Based on these variables, the P requirements for growth and bone development of growing pigs from 20 to 50 kg live weight was 3 g/kg and reduced to 2 g/kg for finisher pigs from 50 to 90 kg live weight.
The effect of trypsin inhibitor on the pancreas and small intestine of mice
Authors: Ge Y. C. , Morgan R. G. H.
Published: June 2005

Pancreatic and intestinal growth rates were measured in mice fed on raw soya-bean flour (RSF) for up to 24 weeks. Control animals were fed on standard chow. The effects of RSF on the mouse pancreas resembled that seen in rats, showing hypertrophy with some hyperplasia. A marked increase in small intestinal weight was also found in mice fed on RSF but not in rats fed on this diet. Histological studies showed an increase in both villous and crypt thicknesses in the small intestine from these mice, and DNA, RNA and protein measurements indicated that the increase in intestinal weight was due to hypertrophy and hyperplasia of the mucosal layer. To determine whether the intestinal growth in mice fed on RSF was purely a response to the trypsin inhibitor (TI) component of the diet, pancreatic and intestinal growth rates were also determined in mice fed on the synthetic trypsin inhibitor camostate, at levels of 0·5 or 2 g/kg in rat chow, for periods of 1–8 weeks. Control animals were fed on standard chow. RSF and 0·5 g camostate/kg had similar trypsin inhibitor activities (measured against bovine trypsin), and both caused similar increases in pancreatic weight, DNA, RNA and protein content. However, 0·5 g camostate/kg did not affect small intestinal weight. Chow containing 2 g camostate/kg contained twice as much TI activity as the RSF diet but produced only a small increase in small intestinal weight at 2 and 8 weeks. This intestinal growth was significantly less than that seen with RSF. The present study shows that, in the mouse, RSF or a diet containing camostate in the appropriate dose produces pancreatic growth comparable to that seen in the rat. RSF also causes intestinal growth, but camostate-containing diets have little or no effect on the growth of the intestine.
Tissue- and substrate-dependent responses of oxidative phosphorylation to dietary protein level in chicks
Authors: Tanaka Masahiro , Ishibashi Teru , Okamoto Katsuyuki , Toyomizu Masaaki
Published: June 2005

The ADP:O values in both cardiac and hepatic mitochondria have significantly decreased with an increase in protein level after 7, 14 and 21 d of feeding (Toyomizuet al.1992). The present studies were undertaken to clarify tissue-specific effects of dietary protein levels on oxidative phosphorylation in the liver, kidney, skeletal muscles and small intestine and to characterize oxidative metabolism with diverse substrates in the liver. Chicks were fed on semi-purified diets of different protein levels (7, 25, 43 and 61% of metabolizable energy content) for 21 d. The responses of protein levels to oxidative phosphorylation showed tissue-dependency; although liver mitochondria of chickens fed on higher- protein diets exhibited reduced ADP:O values and state 3, neither changes in ADP:O value nor state 3 and state 4 rates were observed in the isolated mitochondria from kidney and skeletal muscles. Small intestinal mucosal mitochondria from chickens fed on a high (61%)-protein-energy diet showed significantly reduced ADP:O value and respiratory control ratio when compared with medium-protein- energy diets (25 and 43%). In liver mitochondria showing the most sensitive dependency to the levels of dietary protein, the ADP:O value decreased with increasing protein levels when pyruvate + malate- or glutamate-requiring complexes I, III and IV of the electron transport chain were used as substrates, but it did not change when succinate-requiring complexes II, III and IV or ascorbate + tetramethyl-p- phenylenediamine requiring complex IV was used. These results imply that impaired oxidative phosphorylation capacities with increasing dietary protein levels may be associated with functional damage to the respiratory chain for electron flow from NAD-linked substrates to the ubiquinone pool.
In vitrodigestibility of different prey species of minke whales (Balaenoptera acutorostrata)
Authors: Nordøy Erling S. , Sørmo Wenche , Blix Arnoldus Schytte
Published: June 2005

Information on diet composition, daily energy expenditure, energy storage and the utilization of energy in the prey are important factors when evaluating the food consumption of minke whales (Balaenoptera acutorostrata) during their summer stay in northern waters. The purpose of the present study was in this context to obtain information on the digestible energy (DE) of different prey selected by minke whales. Anin vitrothree-stage digestion technique, simulating the different compartments of the digestive system, has been developed. The initial step simulated the anaerobic microbial fermentation of substrate in the fortestomach. The next stage included the addition of pepsin (EC3.4.23.1)–HCI, simulating ventricle enzymic decomposition, and finally, in the third step, fresh extract from duodenal contents was used to simulate enzymic intestinal degradation of the remaining components of the food. The inoculum was normally obtained from animals which had recently eaten the prey to be tested. In such tests we obtained a dry matter disappearance (DMD) and a DE for herring (Clupea harengus) of 80·4 (SD 5·0)% (n18) and 92·1 (SD 3·7) % (n16) respectively, and a DMD of krill (Thysanoessasp.) of 83·4 (SD 4·9)% (n6). The DMD of krill was reduced to 73·8 (SD 7·3)% (n8) while the DE was 70·6 (SD 10·4) % (n7) when inoculum from whales which had recently eaten cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) was used. These results indicate a high digestibility of the most common species of prey in these animals, and also that the whales have little difficulty in changing from one prey species to another.
Effects of oat rye fractions on biliary and faecal bile acid profiles in Syrian golden hamsters (Mesocricetus auratus)
Authors: Zhang Jie-Xian , Hallmans Göran , Adlercreutz Herman , Åman Per , Westerland Eric , Lundin Eva , Stenling Roger
Published: June 2005

The effects of bran and starchy endosperm fractions of oat and rye on faecal weight and on biliary and faecal bile acids were studied in Syrian golden hamsters (Mesocricetus auratus). The animals fed on diets supplemented with steam-flaked oat bran, oat bran or rye bran had higher wet and dry weights of faeces compared with the animals fed on the fibre-free or low-fibre endosperm diets. A higher mean percentage of biliary cholic acid and a lower mean percentage of chenodeoxycholie and lithocholic (LCA) acids was observed in the bran-supplemented dietary groups. Animals fed on the bran-supplemented diets had increased daily faecal excretion of both total saponifiable and total free bile acids compared with the animals fed on fibre-free or endosperm-supplemented diets. The mean percentage of total saponifiable bile acids in the faeces was higher, and that of free bile acids lower in the animals fed on bran-supplemented diets. A significantly lower concentration of faecal free LCA was observed in the animals fed on the rye-bran diet. Both bran and endosperm diets reduced the faecal LCA: deoxycholic acid compared with the fibre-free diet, but the bran diets had a more pronounced effect than endosperm diets.
Gastrointestinal responses to oats consumption in young adult and elderly rats: digestion, large bowel fermentation and crypt cell proliferation rates
Authors: Mathers J. C. , Kennard Julia , James O. F. W.
Published: June 2005

The present experiment was designed to test the hypothesis that ageing modifies the gastrointestinal responses to a change in diet composition. Rats of the Wag/Rij strain, either young adult (4 months of age) or elderly (27 months of age), were given a basal semi-purified diet or a diet of similar major nutrient composition containing 500 g oatmeal/kg for 17–18 d. Elderly rats digested the dry matter (DM) and organic matter (OM) of both diets less well than did their young adult counterparts, with more of this digestion occurring in the distal intestine. The greater flow of OM to the caecum of oats-fed animals was accompanied by significant reductions in caecal pH and increases in caecal total short-chain fatty acids (SCFA) concentration which appeared to be independent of age. However, young adults responded to feeding on oats by showing a much larger increase in the molar proportion of butyrate (332%) than did elderly animals (79%). Elderly rats had longer duodenal villi than did young adults but effects of age or diet were not detectable at other sites. With both age-groups oats consumption was associated with significant stimulation of crypt cell proliferation rate (CCPR) in the small intestine and caecum, but for the colon there was a significant reduction in CCPR with oats feeding. A reduced ability of the aged large bowel (LB) to produce butyrate may contribute to the prevelance of LB disorders in the elderly.
Interrelationship between vitamin A, iodine and iron status in schoolchildren in Shoa Region, Central Ethiopia
Authors: Wolde-Gebriel Zewdie , West Clive E. , Gebru Haile , Tadesse Amha-Selassie , Fisseha Tezera , Gabre Petros , Aboye Chernet , Ayana Gonfa , Hautvast Joseph G. A. J.
Published: June 2005

A total of 14740 schoolchildren in seven provinces of Shoa Administrative Region in Central Ethiopia were surveyed for the prevalence of goitre, xerophthalmia and anaemia. Haemoglobin and packed cell volume were assessed in 966 children in one province while an in-depth study was conducted on 344 children in the same province and two others. Goitre, xerophthalmia (Bitot's spots) and clinical anaemia were observed in 34·2, 0·91 and 18·6% respectively of the children. Most biochemical variables were within the normal range while those of haemoglobin (Hb), mean corpuscular Hb concentration (MCHC) and urinary I excretion were lower, and mean corpuscular volume, mean corpuscular Hb (MCH), and immunoglobulins G and M were higher. Hb was strongly correlated with retinol. ferritin, MCHC, MCH, packed cell volume and erythrocyte count while retinol formed a triad with transthyretin (TTR) and retinol-binding protein (RBP) which were all correlated with one another. Total and free thyroxin and total and free triiodothyronine were positively correlated as were the concentrations of the total and free hormones. Thyrotropin (TSH) was negatively correlated with total and free thyroxin and positively correlated with free triiodothyronine. Thyroxin and triiodothyronine in both free and combined forms were all correlated with thyroxin-binding globulin which in turn was negatively correlated with the triad retinol, RBP and TTR. The triad was also negatively correlated with C-reactive protein. Urinary I excretion was positively associated with total thyroxin and negatively associated with TSH. The anaemia found was not nutritional in origin but due to the effect of infestation with intestinal parasites and malaria.
Antioxidant enzyme activity in the muscles of calves depleted of vitamin E or selenium or both
Authors: Walsh Dominic M. , Kennedy D. Glenn , Goodall Edward A. , Kennedy Seamus
Published: June 2005

Feeding diets depleted of vitamin E and Se to cattle can induce a disease known as nutritional degenerative myopathy. It is believed that an increased peroxidative challenge in muscle is involved in the pathogenesis of this disease. A number of species can up-regulate the activity of some antioxidant enzymes, including glutathione reductase (EC1.6.4.2), glutathione transferase (EC2.5.1.18), glucose-6-phosphate dehydrogenase (EC1.1.1.49), catalase (EC1.11.1.6), and superoxide dismutase (EC1.15.1.1), in an attempt to mitigate the effects of a peroxidative challenge. A 2 × 2 factorial study was set up to examine possible changes in the activities of these antioxidant enzymes in muscles of ruminant calves fed on diets low in either vitamin E or Se. Four groups of four calves each were fed on a basal diet of NaOH-treated barley which was supplemented with α-tocopherol or Se or both for a total of 50 weeks. Calves fed on diets depleted of vitamin E, but not those ted on diets low in Se, developed subclinical myopathy, as judged by increases in the activity of plasma creatine kinase (EC2.7.3.2), and had increased muscle concentrations of two indices of lipid peroxidation, namely thiobarbituric acidreactive substances, with and without ascorbate activation. Feeding diets depleted of vitamin E and diets low in Se both increased muscle activities of glucose-6-phosphate dehydregenase in heart, biceps and supraspinatus. This change may have occurred in an attempt to maintain intracellular pools of reduced glutathione. No other changes in antioxidant enzyme activity were observed.
Effects of oral administration of brassica secondary metabolites, allyl cyanide, allyl isothiocyanate and dimethyl disulphide, on the voluntary food intake and metabolism of sheep
Authors: Duncan Alan J. , Milne John A.
Published: June 2005

Glucosinolates, such as sinigrin, and S-methyl cysteine sulphoxide (SMCO), which are found in forage brassica species have been implicated in the low intakes observed among lambs consuming such diets. To test both the individual and interactive effects of these compounds in sheep, all combinations of the sinigrin breakdown products, allyl cyanide (ACN) and allyl isothiocyanate (AITC; 10 mmol/d), and the SMCO metabolite dimethyl disulphide (DMDS; 25 mmol/d) were orally administered twice daily for 5 weeks to forty sheep offered dried grass pelletsad lib. As well as measuring voluntary food intake (VFI), a number of haematological and clinical function tests were conducted to assess the physiological effects of the compounds. VFI was significantly depressed by both ACN and AITC but not by DMDS. DMDS significantly ameliorated the effects of ACN on VFI (P< 0.001). Concentrations of reduced glutathione in the blood were depressed by ACN and AITC and elevated by DMDS but no significant interactions were evident. Elevated plasma γ-glutamyl transpeptidase (EC2.3.2.1) activity on ACN and AITC treatments indicated possible liver damage. DMDS elicited a rise in Heinz bodies to 11 % by week 2 but this was not reflected in packed cell volume and blood haemoglobin levels which were unaffected by treatment. The increased Heinz body count caused by DMDS was not further influenced by ACN or AITC. In conclusion, the depressive effects of sinigrin breakdown products on VFI were not compounded by the additional presence of DMDS which, on the contrary, lessened the depression of VFI caused by ACN.
The effect of condensed tannins inLotus pedunculatuson the digestion and metabolism of methionine, cystine and inorganic sulphur in sheep
Authors: McNabbl W. C. , Waghorn G. C. , Barry T. N. , Shelton I. D.
Published: June 2005

Two experiments were conducted with sheep fed on freshLotus pedunculatuscontaining 50–55 g condensed tannin (CT)/kg dry matter. Effects of CT were assessed by comparing control sheep (CT operating) with sheep receiving a continuous intraruminal infusion of polyethylene glycol (PEG) to bind and inactivate CT. Digestion of methionine and cystine was determined using a continuous intraruminal infusion of indigestible markers, whilst plasma irreversible loss (IRL) of methionine, cystine and inorganic sulphate was determined using35S labelling. The proportion of microbial non-NH3-N (NAN) in whole rumen digesta NAN and the IRL of reducible S from the rumen were determined using a continuous intraruminal infusion of (NH4)235SO4. The proportion of microbial NAN in whole rumen digesta NAN (0·44v. 0·71) and the IRL of reducible S from the rumen (0·84v. 2·49 g S/d) were lower in control than PEG sheep. PEG sheep lost 30% of ingested methionine and cystine across the rumen, whereas the control sheep lost no methionine and cystine across the rumen. Apparent absorption of methionine from the small intestine was 27% higher in control than PEG sheep, but both groups had a similar apparent absorption of cystine. The apparent digestibility of cystine in the small intestine was lower in control (0·42) than PEG (0·53) sheep, whereas the apparent digestibility of methionine was similar (0·78) for both groups. CT had no effect on plasma methionine IRL, but markedly increased the IRL of cystine (39·8v. 22·4 μmol/min) and reduced the IRL of plasma inorganic sulphate (35·9v. 50·2 μmol/min). A three-pool model comparing interconversions between the three plasma metabolites showed that CT increased the flow of cystine to body synthetic reactions (36·5v. 17·3 μmol/min). This was due to trans-sulphuration of methionine to cystine being greater in control than in PEG sheep, whilst the oxidation of both methionine and cystine were reduced in control sheep. It was concluded that CT reduced the proteolysis of forage protein and the degradation of S amino acids to inorganic sulphide in the rumen, resulting in increased net absorption of methionine and increased utilization of cystine for body synthetic reactions in sheep with a high capacity for wool growth (and, hence, high cystine requirement).
Seasonal weight loss and metabolic adaptation in rural Beninese women: the relationship with body mass index
Authors: Schultink J. Werner , Van Raaij Joop M. A. , Hautvast Joseph G. A. J.
Published: June 2005

A large variation in seasonal weight loss between individuals exists in rural communities in developing countries. Therefore, it was investigated whether some individuals show a metabolic adaptation and, through that, prevent large body-weight losses during the preharvest season. Basal metabolic rate (BMR), energy intake and physical activity level (PAL) of rural Beninese women were measured in three seasons. Groups of subjects were: women with a body mass index (BMI) < 18 (n 18), and a BMI > 23 (n 16), and women who had shown small (n 18) and large (n 15) preharvest weight loss. All groups of subjects decreased energy intake during the preharvest season by 0·66–1·09 MJ/d. PAL did not show significant seasonal changes in any of the four groups. Only subjects with a BMI < 18 decreased BMR during the preharvest season with 2·9 (SD 6·7) J/kg per min (P < 0·05), with a decrease of 0·8 (SD 1·4) kg (P < 0·05) in body weight. In very thin women with a BMI < 17 (n 5) BMR expressed per unit body weight decreased even more during the preharvest season (by 12 %).
Pretranslational regulation of the expression of the lipoprotein lipase (EC3.1, l.34) gene by dietary fatty acids in the rat
Authors: Murphy M. C. , Zampelas A. , Puddicombe S. M. , Furlonger N. P. , Morgan L. M. , Williams C. M.
Published: June 2005

Although there have been a number of studies of effects of diet and hormones on lipoprotein lipase (EC3.1.1.34; LPL) activity and levels of LPL mRNA (Raynoldset al.1990), there have been no studies which have investigated effects of different dietary fatty acids on LPL gene expression. In the present study male Wistar Albino rats were pair-fed diets containing 50 g fat/kg of different fatty acid composition for 2 weeks. The diets fed were (1) a mixed oil (450 g saturated fatty acids, 420 g monounsaturated fatty acids, 130 g polyunsaturated fatty acids/kg;n8), (2) maize oil (n8), or (3) fish oil (n8). Animals were killed, RNA was extracted from liver and perirenal and epididymal fat pads, and analysed by ‘Northern methodology’. Samples were hybridized to a human cDNA probe for LPL (Gotodaet al.1989). Two transcripts were identified in epididymai and perirenal adipose tissue which were approximately 3·7 and 1·7 kb in size. The results suggested that (1) fish oil-fed animals had significantly greater production of LPL mRNA in epididymai adipose tissue compared with maize oil-fed animals (P< 0·05), (2) maize oil-fed animals had significantly greater production of LPL mRNA in perirenal fat compared with the other dietary groups (P< 0·05), (3) expression in the liver was not significant. Rats fed on a fish oil diet had significantly reduced plasma triacylglycerol concentrations compared with the mixed-oil group (P< 0·05), but there were no significant differences in plasma cholesterol. The differences in LPL could not be explained directly by the changes in plasma immunoreactive-insulin and glucose-dependent insulinotrophic polypeptide levels in the three groups.
Inter- and intra-fat pad variation in vascularization and the release of14C-labelled fatty acids in mice
Authors: Gibney M. J. , Kearney J.
Published: June 2005

Adult laca mice were dosed orally with 150 μl whole milk containing 2·5 μCi of either labelled stearic acid ([1-14C]18: 0;n20) or labelled linoleic acid ([1 −14C]18: 2;n20). The mice were killed in groups of four at 6, 12, 24, 48 and 96 h following dosing and samples of perirenal and epididymal fat pads were taken from both inner and outer sites at each location. Significant differences in the rate of loss of label between sites were found. No differences (P= 0·018) between fat pad locations (epididymalv. perirenal) were found. A significant interaction between rate of loss of labelled fatty acid and site (P= 0·019) reflected the fact that between-site variations in this context were confined to labelled linoleic acid. In a second study weanling adult (n10) and adult (n10) mice were killed and their epididymal and perirenal fat pads prepared for histological examination. Both transverse and longitudinal sections were taken at the inner and outer sites of each fat pad location. Following staining, both the size and number of blood vessels were measured using computer-linked microscopy. In all instances there were significant differences between sites with the inner site consistently showing greater numbers and areas of blood vessels. In general the number of blood vessels in the inner site tended to be greater in older mice, while the reverse was seen for younger mice. The results lend support to the concept of multiple pools of triacylglycerol-fatty acids in adipose tissue such that the main determinant of shortterm supply of essential fatty acids is the quantity recently ingested.
Ileal pH and apparent absorption of magnesium in rats fed on diets containing either lactose or lactulose
Authors: Heijnen Astrid M. P. , Brink Elizabeth J. , Lemmens Arnoldina G. , Beynen Anton C.
Published: June 2005

The hypothesis was tested that dietary lactosev. glucose stimulates Mg absorption in rats because lactose lowers pH of the ileal lumen, which improves Mg solubility which in turn enhances Mg availability for transport across the ileal epithelium. For comparison, the effects of lactulose were studied because it shares with lactose the characteristic of being poorly digestible. Replacement of glucose by lactose (100 g/Kg) significantly stimulated apparent absorption of Mg. Apart from Mg absorption, lactulose also significantly enhanced absorption of Ca and phosphate. Lactosev. glucose lowered the pH of the ileal lumen from 7·5 to 7·2, whereas lactulose significantly reduced it to 7·0. Inin vitroincubations a decrease in pH within the range of fluctuationin vivowas found to cause an improved solubility of Mg, and to a lesser extent also of Ca and phosphate. The smaller fall of ileal pH induced by feeding lactose instead of lactulose may explain why lactose improved Mg absorption only. For all individual rats combined there were negative relationships between ileal pH and apparent absorption of minerals, the relationship being strongest for Mg. Neither lactose nor lactulose was found to raise ileal solubility of minerals, which could relate to the possibility that the time of sampling was not appropriate. It is suggested that lactose-induced stimulation of Mg absorption in rats is caused by a lowering of ileal pH.
Effects of oat-bran concentrate on rat serum lipids and liver fat infiltration
Authors: Mälkki Y. , Törrönen R. , Pelkonen K. , Myllymäki O. , Hänninen O. , Syrjänen K.
Published: June 2005

Oat bran concentrated with respect to both soluble and insoluble dietary fibre was fed to adult rats, and its effects on serum cholesterol and liver fat infiltration were studied. The feeds contained 15, 30 or 45 g β-glucan/kg, except in control groups where the fibre of the feed was cellulose. Half the experimental groups received the feeds with an addition of 10 g cholesterol and 2 g cholic acid/kg in order to create an hypercholesterolaemic condition. In normocholesterolaemic rats the concentrated oat bran did not cause any significant changes in serum cholesterol concentrations, but reduced liver weight compared with control group rats fed on the cellulose-containing diet. In hypercholesterolaemic rats the concentrated oat bran reduced serum total cholesterol and increased high-density-lipoprotein cholesterol concentration. The effect was seen already at the 15 g/kg concentration of β-glucan, the higher doses tested did not significantly improve the effect. Infiltration of fat into liver cells, especially in the periportal areas, was observed only in hypercholesterolaemic animals. The fat infiltration was accentuated in proportion to the amount of oat-bran concentrate fed.
Consumption of thermally-oxidized sunflower oil by chicks reduces α-tocopherol status and increases susceptibility of tissues to lipid oxidation
Authors: Sheehy P. J. A. , Morrissey P. A. , Flynn A.
Published: June 2005

The effect of heated sunflower oil consumption on α-tocopherol status, fatty acid composition and oxidative stability of chicken tissues was investigated. Chicks were fed on diets containing (g/kg): fresh sunflower oil (FSO) 40, heated sunflower oil (HSO) 40 or heated sunflower oil (40) supplemented with α-tocopheryl acetate (HSE) to a similar α-tocopherol concentration as the FSO diet. Concentrations of α-tocopherol in tissues of chicks fed on HSO and HSE were significantly lower than those of chicks fed on FSO. Significant correlations were observed between plasma α-tocopherol concentration and the α-tocopherol concentrations of other tissues (r< 0·67,P< 0·005) and between log plasma α-tocopherol and plasma thiobarbituric acid-reacting substances (TBARS) concentrations (r– 0·851,P< 0·001). The concentrations of TEARS in tissues of chicks fed on the various diets were generally very similar before stimulation of peroxidation with Fe–ascorbate. Susceptibility of tissues to Fe–ascorbate-induced lipid peroxidation was increased by feeding HSO. Supplementation with α-tocopheryl acetate reduced susceptibility tc lipid oxidation to varying degrees, depending on the tissue. The results suggest that chronic ingesrion of oxidized lipids may compromise free-radical-scavenging activityin vivoby depleting α-tocopherol in the gastrointestinal tract, or possibly in plasma and other tissues.
Persistent diarrhoea: efficacy of a rice-based diet and role of nutritional status in recovery and nutrient absorption
Authors: Roy S. K. , Akramuzzaman S. M. , Haider R. , Khatun M. , Akbar M. S. , Eeckels R.
Published: June 2005

A diet based on rice powder, soya-bean oil, glucose, egg-white and salts was given to twenty-six patients of different nutritional status aged 4–18 months with persistent diarrheoa and twenty-five age-matched controls without diarrhoea. Clinical response was monitored during 1 week of dietary treatment and absorption of macronutrients was estimated during a 72 h balance study. Twenty-one patients (81 %) recovered from diarrhoea within 7 d. There were significant relationships between nutritional indices, recovery, and absorption of total energy, fat and N. The absorption of fat, protein and carbohydrate in the better nourished controls without diarrhoea was significantly higher than in patients with persistent diarrhoea with better nutrition or malnutrition. The duration of diarrhoea was significantly longer in lighter patients (weight-for-age < 65% NCHS (1976) standard), in wasted patients (weight/height < 80% of NCHS) and those with mid upper arm circumference (MUAC) less than 110 mm. There were negative relationships between the period of recovery and the coefficient of absorption of fat (P< 0·001), total energy intake (P< 0·01) and MUAC (P< 0·05). Weight-for-age and MUAC showed most effective discriminative power for absorption of nutrients. However, the coefficients of absorption for carbohydrate were not different for any pair of nutritional groups. Absorption of all nutrients was also correlated negatively with severity of persistent diarrhoea on admission. The results of the present study indicate that a rice-based diet is highly effective in the management of persistent diarrhoea, while malnutrition aggravates nutrient malabsorption, increases duration and severity of diarrhoea and less severely malnourished patients do not absorb nutrients as well as healthy controls. Malnutrition and the initial severity of diarrhoea are significant determinants of clinical prognosis and nutrient absorption in persistent diarrhoea.
A study on lipid metabolism in heart and liver of cholesterol-and pectin-fed rats
Authors: Hexeberg Sofie , Hexeberg Erik , Willumsen Nina , Berge Rolf K.
Published: June 2005

Pectin is known as a cholesterol-reducing dietary fibre, and in the present study we addressed the question whether pectin affected the quantity of lipid in droplets in the myocardial cells and of lipid in the liver cells. Male Wistar rats received either a diet containing cholesterol or a standard diet without cholesterol with 0, 50 or 100gpectin/kg incorporated for 10 d. The fractional volume of lipid droplets in the myocardial cells decreased as a function of pectin dose in both the standard-fed and the cholesterol-fed rats. Serum cholesterol was significantly reduced in both groups after addition of 100 g pectin/kg diet. The cholesterol diet increased the liver cholesterol level, and 100 g pectin/kg diet resulted in a lower concentration of liver cholesterol in the cholesterol-fed animals, but the influence on standard-fed rats was modest. Hydroxymethylglutaryl-CoA reductase (EC1.1.1.88; HMG-CoA reductase) activity-increased when pectin was given in the standard diet. Liver triacylglycerol level increased after cholesterol and pectin feeding. Mitochondrial fatty acid oxidation and phosphatidate phosphohydrolase (EC3.1.3.4) activity tended to decrease, whereas the peroxisomal fatty acid oxidation and acyl-CoA oxidase activity were unchanged. Increased hepatic triacylglycerol content by cholesterol and pectin treatment may be due to inhibited mitochondrial fatty acid oxidation along with increased availability of fatty acid for esterification and triacylglycerol synthesis. The presence of pectin in the diets of cholesterol-fed rats resulted in increased hepatic concentration of triacylglycerols and increased mitochondrial fatty acid oxidation. In this case the hepatic accumulation of triacylglycerol may be mediated by a reduced efflux of triacylglycerols from the liver.
Anthropometric values in an elderly French population
Authors: Delarue Jacques , Constans Thierry , Malvy Denis , Pradignac Alain , Couet Charles , Lamisse Fernand
Published: June 2005

We compared anthropometric indices in samples of elderly people aged 65 years and over living in two French areas. The samples were divided into four age-groups (65–69, 70–74, 75–79 and over 80 years). We observed interregional differences in women aged 65–69 years and in men aged 65–74 years. Weight and anthropometric variables related to body fat percentage and to muscle mass showed a decline with age as already reported by others. We established anthropometric percentile values according to sex in pooled subjects when no integrated difference was found. The 50th percentile of arm circumference, muscle arm circumference and triceps skinfold was higher, and the 50th percentile of body mass index was lower than the one reported for the same indices from an elderly Welsh population. Our results show that an interregional difference in anthropometric indices exists in the elderly. The differences which are observed between our results and those reported from a British population emphasize the importance of establishing local values for the elderly population.
A double stable isotope technique for measuring iron absorption in infants
Authors: Kastenmayer Peter , Davidsson Lena , Galanz Pilar , Cherouvrier Françise , Hercberg Serge , Hurrell Richard F.
Published: June 2005

A stable isotope technique has been developed which uses57Fe and58Fe as labels and which enables the simultaneous measurement of Fe absorption from two test meals in infants. The method was evaluated by measuring Fe absorption from a commercial whey-adjusted infant formula in nine healthy infants aged 13–25 weeks. Each infant was fed 210 ml formula, labelled with either57Fe or58Fe, on four consecutive mornings, in random order. The total Fe content in each feed was 2.5 mg Fe; either as 2.5 mg57Fe, or 0 6 mg58Fe plus 1.9 mg Fe with normal isotopic composition. Isotopic enrichment of Fe in erythrocytes was measured by thermal ionization mass spectrometry 14 d after the last administration, and Fe absorption was calculated based on isotope ratio shifts, total circulating Fe and intake of each isotope. Geometric mean absorption for the57Fe and58Fe labels was 6.72 and 658% respectively, and the absorption of the two isotopes was not significantly different (Student's pairedttest). By this technique, paired comparisons of Fe absorption can be obtained and systematic studies of the influence of dietary factors on Fe absorption during infancy can he conducted.
The cardiovascular, metabolic and hormonal changes accompanying acute starvation in men and women
Authors: Webber J. , Macdonald I. A.
Published: June 2005

The effect of fasting for 12, 36 and 72 h was studied in twenty-nine healthy subjects (seventeen women and twelve men). Measurements were made of cardiovascular variables, metabolic rate, respiratory exchange ratio, plasma metabolites, insulin, thyroid hormones and catecholamines. During starvation there were no significant changes in blood pressure, whilst heart rate (beatslmin) increased at 36 h and remained elevated after 72 h (12 h 625 (SE 1.8), 36 h 68.0 (SE 1.9), 72 h 69 2 (SE 1.8);P< 0.001). Forearm blood flow(FBF),increased progressively from 3.32 (SE 0.20) to 6.21(SE0.46) m1/100 ml per min (P< 0.001). Resting metabolic rate (kJ/min) was significantly increased after 36 h of starvation (12 h 4 60 (SE 0.14), 36 h 4 88 (SE 0.13),P< 0.001), but was not significantly different from the 12 h value after 72 h (72 h 4.72(SE0.15)P= 0.06). The respiratory exchange ratio fell progressively from 0.80 to 076 to 0.72 (P< 0.001). Blood glucose fell, whilst plasma glycerol and β-hydroxybutyrate rose and plasma lactate did not change. Plasma insulin and free triiodothyronine fell during starvation. Plasma adrenaline and noradrenaline were unchanged at 36 h, but were significantly increased after 72 h. Both sexes showed a similar pattern of response to starvation, although absolute values of blood pressure, forearm blood flow, metabolic rate and plasma catecholamines were higher in men than women. Acute starvation produces profound cardiovascular and metabolic changes which are not explained by the accompanying hormonal changes.
The response in the blood of piglets to oral doses of galactose and glucose and intravenous administration of galactose
Authors: Bir P. H. , Hartmann P. E.
Published: June 2005

The kinetics of the response in the blond of piglets to physiological oral intakes of galactose and glucose, and intravenous administration of galactose are described. Following the intravenous administration of galactose to 2- and 10-d-old piglets (n 7), the half-life was 7.98 (SD 0.75) and 7.99 (SD 1.89) min respectively, and efficient elimination rate was 9.09 (SD 2.15) and 8.75 (SD 0.79) % per min respectively. The turnover of galactose in the piglets was 100-3 μg/min per kg body weight. These observations demonstrate that galactose was rapidly removed from the blood of the piglets. While the dosing and sampling procedures stimulated hyperglycaemia, they had no effect on the concentration of galactose in the peripheral plasma. The galactose area under the curve (adjusted to the plasma volume of the animal) following a dose of either galactose or galactose plus glucose was 1.75 (SD 0.15) and 1.95 (SD 0.14) arbitrary units respectively in 2-d-old piglets and 1.96 (SD 0.26) and 1.98 (SD 0.10) arbitrary units respectively in 10-d-old piglets. Since the presence of glucose did not lower the adjusted area under the curve for galactose in the peripheral blood, the effect of glucose on the metabolism of galactose in piglets was more like that reported for rats than that for man, guinea-pigs or mice. It is suggested that the galactose moiety of lactose may make an important contribution to the replenishment of liver glycogen in the neonatal piglet.