bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sodium and potassium intakes in a representative population sample: estimation from 24 h urine collections known to be complete in a Cambridgeshire village
Authors: Williams D. R. R. , Bingham Sheila A. 
Published: May 2005

1. A representative sample of eighty men aged 25–44 years from a Cambridgeshire village, each carried out one 24-h urine collection which was analysed for sodium, potassium, creatinine and urea content. The completeness of the collections was verified using oral doses of p-aminobenzoic acid (PABA; the PABA check test).2. In the seventy-one collections shown to be complete, the average 24 h excretion of Na was 172 mmol and the average 24 h excretion of K was 74 mmol.3. Fifty-one of these men's wives also made complete 24 h collections. The average content of these was 128 mmol Na and 61 mmol K.4. Self reports and creatinine index would have identified as incomplete only 29 and 14% respectively of collections so judged by PABA.5. Average excretion of 150 mmol Na/d was similar to estimated intakes of 140–167 mmol/d from the National Food Survey (Bull & Buss, 1980).
Swallowing food without chewing; a simple way to reduce postprandial glycaemia
Authors: Read N. W. , Welch I. McL. , Austen C. J. , Barnish C. , Bartlett C. E. , Baxter A. J. , Brown G. , Comption M. E. , Hume K. E , Storie I. , Worlding J. 
Published: May 2005

1. The degree to which disruption by mastication affects the glycaemic response to four different carbohydrate foods was investigated in healthy human volunteers; each food was eaten by six subjects.2. Subjects ate meals of sweetcorn, white rice, diced apple or potato on two occasions; on one occasion they chewed the food thoroughly, on the other occasion they swallowed each mouthful without chewing it.3. When the foods were chewed the postprandial blood glucose levels rose to levels which vaned according to the food ingested.4. Swallowing without chewing reduced the glycaemic response to each food, achieving a similar effect as administration of viscous polysaccharides or ‘slow-release’ carbohydrates.
T-lymphocyte subsets and interleukin-2 production in zinc-deficient rats
Authors: Dowd Pauline S. , Kelleher. J. , Guillou P. J. 
Published: May 2005

1. It has been suggested that zinc-deficiency impairs cellular (T-lymphocyte-mediated) immune responses via a selective effect on helper T-lymphocytes. We have addressed this question in the rat by employing recently developed reagents in the form of monoclonal antibodies which specifically identify rat T-lymphocyte subsets (identifying total T-cells, helper T-cells and suppressor T-cells) and also by quantifying helper T-cell function by measurement of the helper T-cell-derived molecule interleukin-2 (IL-2).2. Zn-deficiency induced T-cell atrophy (assessed morphologically and phenotypically with anti-rat T-cell monoclonal antibodies) in both peripheral blood and spleen. The use of these specific monoclonal antibodies failed to demonstrate a selective effect of Zn deficiency on the helper T-cell fraction of the total T-lymphocyte population.3. In contrast, the results of functional assays of the T-lymphocyte response were dependent on the conditions of culture but suggested that the generation of IL-2 and its corresponding receptor were determined by the intracellular Zn status. Thus, in vivo, helper T-lymphocyte numbers are non-specifically reduced since other T-cell subsets are also reduced in response to appropriate stimulation. The functional consequences of this are dependent on the intracellular concentration of Zn but appear to influence both IL-2 production and its receptors on activated T-cells.
α-Tocopherol supplements and high-density-lipoprotein–cholesterol levels
Authors: Kalbfleisch John H. , Barboriak Joseph J. , Else Barbara A. , Hughes C. Vincent , Tristani Felix E. 
Published: May 2005

1. In a randomized, double-blind 6-month study, α-tocopherol (728 mg) or placebo were administered daily to seventy-eight volunteers (forty-nine men, twenty-nine women) to investigate the possible enhancing effect of vitamin E on plasma high-density-lipoprotein-cholesterol (HDL-C) levels. In addition, the available reported values from short-term (4–6 weeks) studies, as well as the 4-week results from the present study, were combined and analysed for factors which may modify the effect of α-tocopherol on HDL-C.2. No consistent effect of α-tocopherol on plasma HDL-C levels was observed either in the combined 4-week values or in the 6-month study. Further analysis of the combined short-term values and 6-month values indicated that, in subjects with low initial HDL-C levels, treatment with α-tocopherol or placebo did not produce significantly different HDL-C changes.
The effects of dietary acid stress on bone metabolism in young ovariectomized and intact rats
Authors: kunkel M. E. , Roughead Z. K. , Nichter E. A. , Navia J. M. 
Published: May 2005

1. Two studies were performed to determine the effects of acid stress and ovariectomy on bone metabolism in young rats. In Expt 1, eighteen female weanling Sprague-Dawley-descended rats were ovariectomized, placed in one of three dietary groups and given a diet containing (g/kg): 6 calcium and 3, 6 or 12 phosphorus for 10 weeks. In Expt 2, thirty-two female weanling Sprague-Dawley-descended rats were ovariectomized, and thirty-two were left intact. Eight rats from each group were given a diet containing (g/kg): 6 Ca and 3 P, 12 P, 3 P+1 S or 3 P+20 ammonium chloride for 10 weeks.2. Feeding diets containing 12 g P/kg resulted in decreased serum Ca and increased urinary P with no changes in femur composition. Feeding high-sulphate and ammonium chloride diets resulted in increased urinary Ca and, when combined with ovariectomy, lower femur Ca and P with no changes in femur hydroxyproline or hexosamines.3. The findings reflect the more rapid turnover of the amorphous calcium phosphate salts found in greater amounts in bones of younger animals than for more stable apatitic crystals that predominate in bones of older animals.
Effect of guar gum on gastric emptying of test meals of varying energy content in growing pigs
Authors: Rainbird Anna L. 
Published: May 2005

1. Existing information on whether the action of guar gum in decreasing postprandial blood glucose concentrations is due, at least in part, to a reduced rate of gastric emptying is conflicting, possibly because three types of test meals have been used. In order to test whether the type of test meal used influences the action of guar gum, these three types of meal were compared, either without or with guar gum, in growing pigs. The meals were: a high-energy meal (HEM), a low-energy milky drink (LEMD) and a glucose drink (GD).2. Six pigs were prepared with a simple gastric cannula which allowed complete removal of the stomach contents just before or 0.5, 1, 2 or 4 h after feeding.3. The three types of test meal without guar gum gave rise to very different postprandial profiles of gastric pH and of digesta and dry matter (DM) emptying from the stomach.4. Addition of guar gum to the GD significantly raised gastric pH at 0.5 and 1 h after feeding but, when it was added to HEM, gastric pH was only significantly raised 4 h after feeding. No significant effect on gastric pH was seen when guar gum was added to LEMD.5. Although addition of guar gum to GD had no significant effect on the emptying of digesta from the stomach, when added to HEM the rate of emptying of digesta was significantly reduced 1, 2 and 4 h after feeding. Addition of guar gum to LEMD only significantly increased the amount of digesta remaining in the stomach 2 h after feeding.6. There was no significant effect on the emptying of DM from the stomach when guar gum was added to either HEM or LEMD. However, addition of guar gum to GD significantly reduced the mean rate of emptying of DM 0.5 h after feeding.7. Addition of guar gum to either LEMD or GD had no significant effect on the DM concentration of the evacuated gastric digesta. However, addition of guar gum to HEM significantly lowered the DM concentration of the evacuated gastric digesta 1, 2 and 4 h after feeding.8. It was concluded that differences in test meal composition and also in the methods used to measure gastric emptying could account for the discrepancies previously reported. The results suggest that although guar gum may reduce the rate of gastric emptying under some conditions, this is unlikely to be the only mechanism by which it acts.
Effects of lactation on circulating plasma metabolites in ‘cafeteria-fed’ rats
Authors: Salvadö J. , Segués T. , Alemany M. , Arola L. L. 
Published: May 2005

1. The effects of ‘cafeteria feeding’ on primiparous Wistar rats during lactation have been studied by measuring circulating levels of glucose, amino acids, lactate, urea and ammonia as well as glycogen levels in liver and muscle.2. No significant changes in glucose levels were observed despite alterations in blood glucose compartmentation.3. Compared with controls, the dams given the cafeteria diet had higher liver glycogen stores which were more easily mobilized at the peak of lactation.4. Rats given the cafeteria diet showed a lower amino acid utilization than controls and adequately maintained circulating levels, as determined by the lower circulating levels of ammonia and urea.5. No significant differences in body-weight were observed in the period studied despite increasing dam weight after weaning in the cafeteria-fed group.6. The size of pups of cafeteria-fed dams was greater than that of controls, and the differences were marked after weaning, when the metabolic machinery of the cafeteria pup maintained high protein accretion and body build-up using fat as the main energy substrate characteristic of the preweaning stage. The controls, however, changed to greater utilization of amino acids as an energy substrate and adapted to high-protein (low- biological-quality) diets with a significantly different pattern of circulating nitrogen distribution.
The distribution of peptidase activity in the small intestine of sheep
Authors: Richardson R. I. , Jouan A. R. P. 
Published: May 2005

1. The activity of peptidase enzyme(s) was measured in homogenates of mucosa taken at slaughter from sites along the length of sheep small intestine.2. The activity of the homogenate towards six dipeptides showed a similar pattern of distribution for each substrate. Activity was lowest in the proximal duodenum, rising through the jejunum to peak in the mid-ileum and declining towards the terminal ileum. The distribution of activity towards two tripeptides was similar.3. Studies using the inhibitor p-hydroxymercuribenzoate showed that the activity towards the dipeptides was mainly localized in the cytosol fraction, while that towards the tripeptides was evenly distributed between the cytosol and the brush-border and activity towards a tetrapeptide was mainly associated with the brush-border.4. The results are discussed in relation to the site and mechanism of protein digestion and absorption in the ruminant small intestine.
Exchanges of water and certain water-soluble minerals during passage of digesta through the stomach compartments of young ruminating bovines
Authors: Edrise B. M. , Smith R. H. , Hewiti D. 
Published: May 2005

1. Four ruminating bull calves were provided with cannulas in the rumen and abomasum and a sleeve sutured at the omosal-abomasal orifice that permitted digesta flowing from the omasum to be diverted and collected.2. The calves were each given in turn a high-roughage (HR) and high-concentrate (HC) diet consisting mainly of dried grass and flaked maize in the proportions 3:2 and 1:2 by weight respectively. Water-soluble non-absorbable marker (polyethylene glycol) was also given and the diets were sometimes supplemented with magnesium sulphate. For each diet (HR(0), HR(Mg), HC(0), HC(Mg)), collections were made from the rumen, reticulum, omasal outflow and abomasum, and flows of water, sodium, potassium and chloride calculated at these sites relative to intakes.3. The general pattern of net exchange was similar for all the diets. Substantial additions of water and Na, a small addition of K and a small absorption of CI occurred between mouth and reticulum. Substantial (approximately 40–60%) absorption of water and Na, a small absorption of K and considerable secretion of Cl occurred in the omasum. Quantitative comparisons indicated that addition of water and Na up to the reticulum, presumably in saliva, was significantly greater for the HR than the HC diets. Addition of Mg appeared to stimulate absorption of Na and water up to the reticulum for unknown reasons. Re-absorption of these components in the omasum varied for different calves and diets but appeared to be influenced primarily by a positive linear relation between amounts of digesta flowing into the omasum and amounts of water and Na absorbed from it. The proportion of water absorbed also increased with increasing entry rates of water.4. Other findings showed that pH values rose slightly (about 0.2 pH units) but significantly in the reticulum compared with the rumen and that the value fell again by about the same amount during the passage of digesta through the omasum. Changes between omasal outflow and the abomasum were as expected, with marked additions of Cl, Na and water and a fall in pH.
Effect of heat on the nutritional value of lupin (Lupinus angustifolius) – seed meal for growing pigs
Authors: Batterham E. S. , Andersen L. M. , Burnham B. V. , Taylor G. A. 
Published: May 2005

1. Two experiments were conducted to determine the effects of heat on the nutritional value of lupin (Lupinus ungustifoliuscv. Uniharvest and Unicrop)-seed meal, relative to soya-bean meal, for growing pigs.2. In both experiments, values for carcass gain/d and food conversion ratio (FCR) on a carcass basis of pigs fed on the diets containing lupin-seed meal were inferior (P < 0.05) to those produced by pigs fed on soya-bean meal.3. In the first experiment, heating lupin seed at temperatures from 105 to 150° for 15 min resulted in a linear depression in carcass gain/d, a quadratic increase in carcass FCR, a linear decrease in lean in the ham and a linear increase in backfat thickness. In the second experiment, autoclaving lupin seed from 5 to 45 min at 121° resulted in a linear depression in carcass gain/d and a linear increase in carcass FCR.4. The addition of L-lysine to the diets containing lupin-seed meal verified that lysine was limiting in both experiments. The additions of L-lysine did not overcome the differences in carcass gains/d of pigs fed on lupin-seed meal relative to those fed on diets containing soya-bean meal.5. It is concluded that the low lysine availability in lupin-seed meal for pigs is not due to the presence of heat-labile anti-nutritional factors in the seed.
The utilization of lysine by young pigs from nine protein concentrates compared with free lysine in young pigs fed ad lib
Authors: Jane Leibholz 
Published: May 2005

1. Pigs (n 195) between 21 and 49 d of age were given a basal diet containing wheat, wheat gluten and cotton-seed meal which was supplemented with one of nine protein concentrates or free L-lysine. The diets were given ad lib. in two experiments.2. Increasing the lysine content of the diets from 6.9 to 10.1 g/kg increased the weight gains of the pigs from 89 to 317 g/d in the first experiment. In the second experiment the weight gains were increased from 68 to 213 g/d by increasing the lysine content of the diets from 5.9 to 9.5 g/kg.3. The utilization of lysine from the protein concentrates was compared with the utilization of free L-lysine.4. The utilization of lysine for weight gain compared with free lysine was 0.86–0.88 for meat meals, 0.95–0.99 for soya-bean meal, 0, 69–0.75 for cotton-seed meal, 0.90 for lupins (Lupinus augustifoh) and 0.99 for milk.
Hexose absorption from jejunal loopsin situin zinc-deficient and Zn-supplemented rats
Authors: Southon Susan , Gee Jennifer M. , Johnson I. T. 
Published: May 2005

1. Immature, male Wistar rats were given a low-zinc semi-synthetic diet (2 mg Zn/kg) for 22–28 d. Control groups received a similar diet supplemented with 58 mg Zn/kg eitherad lib., or in amounts matched to the consumption of the Zn-deficient group. There was a rapid onset of reduced food consumption and growth retardation in the Zn-depleted animals.2. Serosal surface area of small intestines taken from Zn-deficient rats was significantly reduced compared with that of control animals. Villi, dissected from samples of proximal jejunum, were markedly smaller than those of control rats and were present in greater numbers per unit area of serosa.3. Luminal loss of galactose from jejunal loopsin situwas significantly greater in the Zn-deficient rats compared with controls when expressed in terms of unit dry weight of intestine and serosal or villous surface area. Since only a small proportion of the total galactose remained in the mucosal tissue and associated extracellular space, this loss could only be accounted for by an increased efficiency of net transepithelial transport. Differences in total galactose absorption per unit length of jejunum were not so marked.4. This intestinal adaptation to Zn-deficiency allows the maintenance of normal, and possibly increased, rates of hexose transfer into the body of animals exhibiting severe growth retardation, reduced food utilization and abnormal glucose metabolism.
Nitrogen balance in relation to energy intake in entire male pigs weighing 75 kg
Authors: Dunkin A. C. , Black J. L. , James K. J. 
Published: May 2005

1. Nitrogen balance (NB) was determined in entire male pigs weighing 75.6 (SE 0.56) kg and given 1.43 MJ metabolizable energy (ME)/kg live weight (LW)0.75 per d of semi-synthetic liquid diets which varied in crude protein (N x 6.38):ME from 2.5 to 14.5 g/MJ. Maximum NB of 20.8 g/d was reached with diets containing at least 6.2 g protein/MJ ME.2. The relation between energy intake and NB was then examined in pigs of comparable live weight (mean 73.8 (SE 0.39) kg) and receiving a liquid diet not limiting in protein. The diet, containing 10.0 g protein/MJ ME, was given at eight rates from 0.24 MJ ME/kg LW0.75 per d to ad lib. by approximately equal increments. Two animals were allocated to each level and two animals were fasted during the balance period.3. The animals fed ad lib. achieved a mean intake of 1.84 MJ ME/kg LW0.75 per d. NB increased linearly as ME intake increased up to 27.6 MJ/d (1.096 MJ/kg LW0.75per d) but thereafter remained constant at 22.8 g N/d.
Growth and development of rats artificially reared on rats 'milk or rats' milk/milk-substitute combinations
Authors: Tonkiss J. , Smart J. L. , Massey R. F. 
Published: May 2005

1. Rat pups were artificially reared (AR) from post-natal day 5 by intermittent gastric infusion. Mother-reared (MR) siblings served as controls. Fourteen measures of body and organ growth were taken at the end of each experiment.2. In Expt 1, two batches of pups were given rats' milk only, obtained by manual expression from anaesthetized dams.3. The first batch, reared to 12 d, grew less well than the MR group, probably because they received too little milk. However, relative to body-weight, organ weights were as great or greater than those of MR pups, except for heart weight. The second batch, given more milk and reared to 20 d, showed no deficits in organ or body-weights, but excesses in kidney, gastrocnemius muscle, stomach and caecum weights. There were no losses from ‘bloat’, a condition of gastrointestinal distention often encountered in artificial rearing with milk substitutes.4. Obtaining rats' milk is extremely labour-intensive and in Expt 2, more economical regimens were devised in which pups were started off on expressed rats' milk and then changed to a milk substitute resembling rats' milk in composition, either abruptly at 12 d or gradually between 8 and 17 d.5. Both regimens were successful, in that there were no losses from bloat and most measures of growth were at least as great as in the MR group. Only heart weight was lower in both AR groups and adrenal weight in the abruptly changed AR group. The weights of the stomach and caecum and the length of the small intestine were all high in both AR groups.6. It is concluded that giving rat pups expressed rats' milk for the first few days of artificial rearing largely avoids the problem of bloat and results in satisfactory growth.
Studies on the effects of dietary zinc dose on 65Zn absorption in vivo and on the effects of Zn status on 65Zn absorption and body loss in young rats
Authors: Coppen D. E. , Davies N. T. 
Published: May 2005

1. Weanling male rats were maintained on diets containing 5, 10, 20, 40, 80 or 160 mg zinc/kg for 14 d. On day 15 they received 65Zn either by intraperitoneal injection or in a test meal containing 20 mg Zn/kg. After dosing, the rats were again maintained on the diets they had received previously.2. Whole-body 65Zn retention was measured immediately after dosing and daily for a further 9 d. From regression analysis of the semi-logarithmic plots of 65Zn retention from 0 to 192 h after 65Zn administration, the true extent of 65Zn absorption and the biological half-life (t1/2) of body 65Zn stores were calculated.3. At the end of the experiment, the rats were killed and the entire small intestines of some rats from each group were rapidly flushed out to remove food and faecal residues, frozen in liquid nitrogen and stored under an atmosphere of N2 at –20° before separation of cytosolic Zn-binding fractions by gel filtration on Sephadex G–75.4. The results suggest that rats which received diets that were either deficient(5 mg Zn/kg), marginal (10 mg Zn/kg) or adequate (20–80 mg Zn/kg) in Zn achieved homeostatic regulation of body Zn by changes in both the extent of Zn absorption and excretion. However, when Zn supply was excessive, increasing from 80 to 160 mg Zn/kg, no further changes were seen in Zn absorption, and homeostatic control appeared to be effected entirely by changes in rates of body Zn loss.5. Gel chromatography of intestinal cytosol on Sephadex G-75 revealed that Zn was associated with two major fractions. The first (peak 1) had a molecular weight (MW) > 75 kdaltons and the second (peak 2), a MW of approximately 10 kdaltons and was assumed to be metallothionein.6. There was no obvious relation between the amount of Zn bound to peak 1 and dietary Zn content. In contrast, the amount of Zn recovered in peak 2 increased linearly with increasing dietary Zn content.7. Comparisons between the effect of dietary Zn content on Zn bound to peak 2 and 65Zn retention may, depending on the range of Zn intakes, indicate possible roles for intestinal metallothionein in the control of Zn absorption or excretion.8. A study of the effects of dietary dose of 65Zn on the extent of 65Zn absorption in rats of normal Zn status indicated a possible biphasic relation. At low doses (5–40 mg Zn/kg) 65Zn absorption appeared to exhibit a curvilinear response to increasing 65Zn dose, indicating possibly a saturable process. At higher doses (40–160 mg Zn/kg) the capacity of this process appeared to be exceeded and 65Zn absorption increased in a linear fashion.