bluuebunny/crossref_metadata_2025_split huggingface dataset:
The tryptophan requirement of the kitten
Authors: Hargrove Diane M. , Rogers Quinton R. , Morris James G. 
Published: September 2005

1. To estimate the tryptophan requirement of the kitten, six male and six female kittens were presented diets containing 0·7, 0·9, 1·1, 1·3, 1·5 and 3·0 g tryptophan/kg diet for six experimental periods lasting 10 d in accordance with a 6 × 6 balanced Latin-square design.2. Mean daily weight gain and nitrogen retention (N intake minus urinary and faecal N) plateaued at 1·1 g tryptophan/kg diet indicating that the minimal tryptophan requirement of the kitten was 1·1 g/kg diet.3. Plasma tryptophan concentration exhibited a marked increase at dietary tryptophan concentrations above 1·3 g/kg diet.
Human energy metabolism below, near and above energy equilibrium
Authors: Van Es A. J. H. , Vogt J. E. , Niessen CH. , Veth J. , Rodenburg L. , Teeuwse V. , Dhuyvetter J. , Deurenberg P. , Hautvast J. G. A. J. , Van Der Beek E. 
Published: September 2005

1. Complete 24 h energy and nitrogen balances were measured for fifteen subjects at three levels of energy intake and for two other subjects at two levels of intake.2. At each level, the fifteen subjects ate diets consisting of fifteen to twenty separate foods for 7 or 8 d. Faeces and urine were collected for the final 4 d. Respiratory gas exchange was measured during the final 72 h while the subjects stayed in an 11 m3open-circuit respiration chamber, and simulated office or light household work. The energy balance of the other two subjects was determined initially in a similar way when they consumed a diet which was sufficient for energy equilibrium. Subsequently, the measurements were repeated twice at the same high level of metabolizable energy (ME) intake after 4 and 18 d on that diet.3. Neither energy nor N digestibilities were significantly affected by intake level or subject. Due to relatively small urinary energy losses the ME content of the gross energy increased slightly at the higher intake.4. Respiratory quotient increased with intake level from 0.78 to 0.87.5. The efficiencies of utilization of ME were approximately 1.0 for maintenance (from the low to the intermediate intake level) and decreased to about 0.9 for maintenance and energy deposition (from the intermediate to the high intake level).6. Estimates of daily ME requirements at energy equilibrium were 149 (SD 13) kJ ME/kg body-weight, 432 (SD 33) kJ ME/kg body-weight0.75and 204 (SD 22) kJ/kg lean body mass. The former two values were negatively correlated with percentage body fat although not significantly so.7. ME utilization and heat production of the other two subjects were nearly equal after 6 and 20 d on a diet supplying 1.5–1.7 times the ME needed for energy equilibrium.
Effect of dietary supplements of guar gum and cellulose on intestinal cell proliferation, enzyme levels and sugar transport in the rat
Authors: Johnson I. T. , Gee J. M. , Mahoney R. R. 
Published: September 2005

1. Male Wistar rats (approximately 200 g) were given fibre-free semi-synthetic diets containing either sucrose (S) or a sucrose-starch mixture (SS) as the carbohydrate component, or a diet similar to SS containing 40 g guar gum/kg (G), or 100 g cellulose/kg (C). The animals remained healthy, and weight gain after 30 d was similar in all groups.2. The small intestines of the animals given diet G were significantly longer than those of the other groups, and showed signs of increased mitotic activity and mucosal growth.3. No significant differences in mucosal enzyme activity were detected between the two fibre-free control groups. Lactase (EC3.2.1.23) and alkaline phosphatase (EC3.1.3.1) activities were significantly lower than controls in group G, but were higher in group C.4. Kinetic analysis of 3-O-methyl glucose uptake by isolated intestine indicated that the maximum transport rate (Vmax) of tissue from group G tended to be lower than from the fibre-free group SS and group C.5. It is concluded that materials which are classed as dietary fibre but which differ markedly in their physical properties may also differ in the functional changes to which they give rise in the small intestine. These changes may be at least partially mediated by effects on mucosal cell proliferation.
Effect of guar gum on glucose and water absorption from isolated loops of jejunum in conscious growing pigs
Authors: Rainbird Anna L. , Low A. G. , Zebrowska Teresa 
Published: September 2005

1. Four pigs initially of 30 kg live weight were surgically prepared with two re-entrant cannulas in the jejunum 1.0 m apart which allowed an isolated loop to be formed through which solutions were perfused. 51Cr-EDTA was used as a marker for measuring net secretion or absorption.2. A new Ringer solution was made, the ionic content of which resembled more closely that found in the jejunum of pigs given similar diets, than Krebs-Ringer solution.3. The absorption of glucose and water from Krebs-Ringer and new Ringer solutions was compared.4. The effect of guar gum on the absorption of glucose and water from solutions of glucose and maltose was studied.5. There was a trend (not significant) for greater absorption of glucose and water from the new Ringer solution than from the Κ rebs-Ringer solution.6. Guar gum significantly reduced the net absorption of glucose from glucose or maltose solutions from 74.2 to 41.4% (P < 0.001) and 71.1 to 35.0% (P < 0.001) respectively.7. Guar gum significantly reduced the net absorption of water from the glucose solution from 42.7 to 8.3% (P < 0.01) and from the maltose solution from 49.2 to 5.1% (P < 0.001).8. The lack of differences between the absorption of glucose from solutions of glucose or maltose suggested that maltase (EC 3.2.1.20) activity was not inhibited to the extent that this limited the rate of glucose absorption.
Digestibility of proteins of the histological components of cooked and raw rice
Authors: Bradbury J. Howard , Collins J. Grant , Pyliotis N. A. 
Published: September 2005

1. The aleurone layer, grain coat and embryo which constitute rice bran are rich in vitamins, lipids, protein and lysine compared with the endosperm (milled rice).2. A method was developed to measure the in vitro protein digestibility of raw and cooked brown rice and their histological components.3. The protein digestibility of cooked endosperm by the in vitro method agreed with that of other workers using in vivo techniques.4. The protein digestibility of the aleurone layer and grain coat from raw rice was only 25% but increased to 65% from cooked rice, due to disruption of the cellulosic cell walls at 100°, which was shown by electron microscopy.5. The decreased protein digestibility due to cooking was not the result of formation of ε-lysyl–γ-glutamyl isopeptide cross-links, but may be due to formation of a cystine-rich core that is resistant to proteases.6. The protein digestibility of cooked brown rice was approximately the same as that of cooked milled rice, hence it is advantageous for those for whom rice is a staple food to consume brown rather than milled rice.
The mode of action of anabolic agents: the effect of testosterone on muscle protein metabolism in the female rat
Authors: Martinez J. A. , Buttery P. J. , Pearson J. T. 
Published: September 2005

1. Testosterone (1 mg/kg body-weight per d) given subcutaneously to female rats increased their growth rate and food conversion efficiency but not their food intake compared with that of the placebo-oil controls. A higher dose of testosterone (10 mg/kg body-weight per d) failed to increase the daily weight gain.2. The increased growth rate of the testosterone-treated rats appeared to occur in the whole body and not specifically in muscle. There were no significant changes in body composition.3. The fractional synthetic rate of gastrocnemius muscle protein was higher in the hormone-treated rats than in controls. This contrasts with previous results for the anabolic agent trenbolone acetate and reflects differences in the mode of action of these two different steroids, both with androgenic properties.
The nutritive value of rumen micro-organisms in ruminants
Authors: Strom E. , Øskov E. R. 
Published: September 2005

1. Four experiments were carried out to identify and quantify the limiting amino acids (AA) in rumen microbial protein (RMP).2. A method was developed which involved first, an assessment of the efficiency of utilization of absorbed AA-nitrogen (U) of RMP, defined as the retention of AA-N from RMP absorbed from the small intestine, and second, addition of a mixture of AA similar to the absorbed AA profile in a quantity defined by the U of RMP and equal to (1 – U)/U. Third, it involved removal of each AA in turn and measurement of the resultant N retention. Using this approach it was possible to calculate both the order and extent of AA limitations in RMP.3. Apart from methionine which was found to be the most limiting AA, only lysine, arginine and histidine reduced N retention when omitted, and accordingly only these AA were limiting in RMP.4. The method is discussed in detail and the amount of supplementary AA required to utilize RMP fully is calculated.
Dietary supplementation increases milk output in the rat
Authors: Roberts Susan B. , Coward W. A. 
Published: September 2005

1. The effects of dietary supplementation on milk output and maternal body composition were investigated in the lactating rat. The supplement was a cooked homogeneous mixture of eggs and maize oil, and had the same protein-energy: total energy value as the control diet.2. During 2–12 d post partum rats were fed ad lib., either on the control diet alone or on the control diet plus the supplement. Measurements were made of milk output using an isotope-dilution technique, milk composition, and dam and litter body-composition changes.3. Compared with the dams receiving only the control diet, dams provided with the supplement consumed 19.7% more energy and protein and produced 31.2% more milk and mobilized less body fat.4. By 12 d of age, pups in litters of dams receiving the supplement were significantly heavier than those in litters of dams receiving the control diet only, and they contained more protein and more fat.5. It is concluded that dietary supplementation of lactating rats can enhance lactational performance.
Effects of meal consumption on whole body leucine and alanine kinetics in young adult men
Authors: Hoffer Leonard J. , Yang Russell D. , Matthews Dwight E. , Bistrian Bruce R. , Bier Dennis M. , Young Vernon R. 
Published: September 2005

1. The effects of meal consumption on plasma leucine and alanine kinetics were studied using a simultaneous, primed, continuous infusion of L-[I-13C]leucine and L-[3,3,3-2H3]alanine in four healthy, young, adult male subjects. The study included an evaluation of the effect of sampling site on plasma amino acid kinetics, with blood being drawn simultaneously from an antecubital and dorsal heated hand vein.2. In comparison with the postabsorptive state, the ingestion of small hourly meals resulted in a 35% increase in plasma leucine flux and a 77% increase in leucine oxidation. Calculated entry of leucine into the plasma compartment from endogenous sources decreased by 65%. Plasma alanine flux more than doubled, indicating a significant enhancement in de now alanine synthesis.13C enrichment of leucine in venous and arterialized plasma did not differ significantly, but alanine flux calculated from isotopic measurement in venous plasma was substantially greater than that based on analysis of arterialized blood plasma.
Relation of antigenic structure of cereal proteins to their toxicity in coeliac patients
Authors: Ciclitira P. J. , Ellis H. J. , Evans D. J. , Lennox E. S. 
Published: September 2005

1. Unfractionated gliadin and its α-, β-, γ- and ω-gliadin subfractions were used as rabbit immunogens. The antisera were characterized by (1) Ouchterlony double diffusion, (2) binding of 125I-labelled gliadin subfractions, (3) inhibition by several gliadin subfractions of binding between γgliadin antiserum and 125I-labeIled γgliadin.2. Double diffusion showed identical cross-reactivity between the antisera and the gliadin subfractions with the exception of ω-gliadin. Precipitin lines of partial identity with gliadin were observed against rye secalins and barley hordeins but not oat avenins or maize zeins.3. Binding was observed between unfractionated 125I-labelledα-, β-, γ- and ω-gliadins and all the antisera. There was binding of 125I-labelled ω-gliadin to the ω-gliadin antiserum but poor binding of 125I-labelled ω-gliadin to unfractionated α-, β- and γ-gliadin antisera. Competitive inhibition of binding between 125I-labelled γ-gliadin and γ-gliadin antiserum diluted 1:250 (v/v) demonstrated similar competition between α-, β- and γ-gliadins and this antiserum but poor competition between ω-gliadin, wheat glutenins, albumins and globulins, rye secalins, barley hordeins and oat avenins.4. These findings suggest that there is a good correlation between the antigenic structure of gliadin proteins and their toxicity to patients with coeliac disease.
Gluconeogenesis from caecal propionate in the horse
Authors: Ford E. J. H. , Simmons H. A. 
Published: September 2005

1. The production of propionate in the caecum of the horse has been measured in two Shetland-type ponies fitted with caecal and colonic cannulas and fed on hay or on hay and wheat bran. A continuous intracaecal infusion of14C-labelled sodium propionate was used and samples were obtained from a cannula at the origin of the right ventral colon. A simultaneous intravenous infusion of [2-3H]glucose was used to measure total glucose entry.2. On a hay diet which provided 177 kJ/kg body-weight per d, mean caecal propionate production was 19.6 (range 17.2–21.2) mg/h per kg body-weight and on a hay and wheat bran diet, which provided 187 KJ/kg body-weight per d, mean caecal propionate production was 34.0 (range 28.9–38.3) mg/h per kg body-weight.3. Mean total glucose production (mg/h per kg body-weight) in one pony was 104 (range 100–110) and in the other 135 (range 123–153). Rates were not influenced by diet.4. About 7% of total glucose production was derived from propionate produced in the caecum and this percentage was unaffected by diet or by individual animals.
Differences in intestinal protein synthesis and cellular proliferation in well-nourished rats consuming conventional laboratory diets
Authors: Southon Susan , Livesey G. , Gee Jennifer M. , Johnson I. T. 
Published: September 2005

1. Male Wistar rats (100 g) were given a commercial pellet feed or a semi-synthetic dietad lib. Although the pellet-fed group grew slightly faster than the other group during the early part of the feeding period, there was no significant difference between the final weights of the groups.2. The fractional rates of protein synthesis in jejunum, proximal ileum and liver were measured by a technique based on the determination of L-[4−3H]phenylalanine incorporation over a short time period. Protein synthesis was higher in both jejunum and ileum of the pellet-fed rats compared with those eating the semi-synthetic diet, but there was no difference between the rates of protein synthesis measured in the livers of the groups.3. The rate of mucosal cell division was significantly faster in the ileal mucosa of the pellet-fed group compared with the other group, and there were significant differences in some aspects of mucosal morphology.4. The maintenance of higher rates of cell turnover and protein synthesis in animals given commercial pellet feed is unexplained, but it may be related to the presence of non-absorbable polysaccharides or other complex plant materials in the pellet feed.
The effect of iron substrate on mitochondria1 haem synthesis in copper deficiency
Authors: Williams Darryl M. , Kennedy F. Scott , Green Brenda G. 
Published: September 2005

1. Studies of iron utilization and haem synthesis were carried out with hepatic mitochondria obtained from copper-deficient and pair-fed control rats.2. Ferric chloride can be used as Fe substrate for mitochondrial haem synthesis in the presence of succinate. Utilization is further enhanced by the addition of FMN.3. Ferritin does not support haem synthesis in the presence of succinate alone, but does support haem synthesis when FMN is added.4. Mitochondria1 haem synthesis is impaired in Cu deficiency when either FeCl3or homologous ferritin is used as Fe substrate.5. The results of the present study suggest that impaired haem synthesis in Cu deficiency occurs at a step following the chemical reduction of Fe substrate.
The digestion of protein in young pigs and the utilization of dietary methionine
Authors: Leibholz Jane 
Published: September 2005

1.Forty pigs between 23 and 51 d of age were given adlib. diets containing wheat and one of five protein concentrates: meat meal A, meat meal B, soya-bean meal, milk and lupins (Lupinus augustifolius). Twenty of these pigs were given indigestible markers from 51 to 56 d of age and were killed at 56 d of age.2.The diets containing meat meals A and B, soya-bean meal and milk contained 2.3 g total methionine/kg and the diet containing lupins contained 2.1 g/kg.3.A further forty pigs of the same age were given the same diets supplemented with 1 g synthetic methionine/kg.4.The weight gains and feed conversion ratios of the pigs given the diets containing 2.1–2.3 g methionine and 3.1–3.3 g methionine/kg were not significantly different.5. The weight gains of the pigs given lupins (2.1 g methionine/kg) were less than those of the pigs given the diets containing 2.3 g methionine/kg.6. The apparent digestibility of dry matter (DM) and nitrogen was less for the diets containing the meat meals (0.75 and 0.78 respectively) than for those containing the other protein concentrates (0.80 and 0.84).7.The retention times in the large intestine of the diets containing soya-bean meal and lupins were 965 and 1083 min which were greater than those of the diets containing the other protein concentrates, mean 732 min.8. The major site of N digestion and absorption for the diet containing milk was the area of the small intestine 25–50% of total length from the pylorus, while for the other protein concentrates the major site was 50–75% of its total length from the pylorus.9. The digestion and absorption of N in the large intestine was less (3.4%) for the diet containing milk than for those containing the other protein concentrates (7.5–11.3%).10. The apparent digestibility of the methionine to the ileum for the five diets ranged from 0.74 to 0.86 while the calculated retention of the apparently-absorbed methionine was 1.00. It was suggested that methionine digestibility could be used as an indicator of availability.11. The calculated retention of apparently absorbed N in the carcass was 0.71 for the pigs given the diet containing milk and 0.51–0.58 for the pigs given the other diets.
Some effects of vitamin E and selenium deprivation on tissue enzyme levels and indices of tissue peroxidation in rainbow trout (Salmo gairdneri)
Authors: Bell J. G. , Cowey C. B. , Adron J. W. , Shanks Aileen M. 
Published: September 2005

1. Duplicate groups of rainbow trout (Salrno gairdnert) (mean weight 11 g) were given for 40 weeks one of four partially purified diets that were either adequate or low in selenium or vitamin E or both.2. Weight gains of trout given the dually deficient diet were significantly lower than those of trout given a complete diet or a diet deficient in Se. No mortalities occurred and the only pathology seen was exudative diathesis in the dually deficient trout.3. There was significant interaction between the two nutrients both with respect to packed cell volume and to malondialdehyde formation in the in vitro NADPH-dependent microsomal lipid peroxidation system.4. Tissue levels of vitamin E and Se decreased to very low levels in trout given diets lacking these nutrients. For plasma there was a significant effect of dietary vitamin E on Se concentration.5. Glutathione (GSH) peroxidase (EC1. 1 1. 1.9) activity in liver and plasma was significantly lower in trout receiving low dietary Se but was independent of vitamin E intake. The ratios of hepatic GSH peroxidase activity measured with cumene hydroperoxide and hydrogen peroxide were the same for all treatments. This confirms the absence of a Se-independent GSH peroxidase activity in trout liver.6. Se deficiency did not lead to any compensatory increase in hepatic GSH transferase (EC2. 5. 1. 18) activity; values were essentially the same in all treatments.7. Plasma pyruvate kinase (EC2. 7. 1.40) activity increased significantly in the trout deficient in both nutrients. This was thought to be due to leakage of the enzyme from the muscle and may be indicative of incipient (subclinical) muscle damage.
Evidence suggesting that the elevated plasma triiodothyronine concentration of rats fed on protein deficient diets is physiologically active
Authors: Sawaya Ana Lydia , Lunn P. G. 
Published: September 2005

1. Some metabolic indicators of thyroid hormone activity have been investigated in rats fed on either protein-deficient or energy-restricted diets.2. Rats were divided into three groups. Control animals were maintained on a diet of protein energy: total energy (P:E) value of 0.20, while the low-protein group (LP) were allowed adlib. access to food of P:E 0.03. Energy-restricted (ER) rats were given limited amounts of a control diet (P:E 0.20) such that their rate of growth matched that of LP animals.3. Animals fed on the LP diet had elevated plasma concentrations of both total and free triiodothyronine (T3)concentrations whereas those on the ER regimen showed values below those of controls.4. The activities of mitochondria1 α-glycerol-3-phosphate dehydrogenase (EC1. 1.99.5) and of the αglycerol-3-phosphate shuttle system were elevated in the liver of LP rats, but malate-aspartate shuttle operation was reduced. All three activities were reduced in ER animals.5. Cytochrome c oxidase (EC1.9.3.1) activity of brown adipose tissue indicated a high rate of thermogenic activity in this tissue in LP rats, but ER animals showed some evidence of below normal function.6. The results indicate that both the raised plasma T3of LP rats and the reduced levels observed in ER animals are physiologically significant.
Urea turnover and transfer to the digestive tract in the rabbit
Authors: Forsythe S. J. , Parker D. S. 
Published: September 2005

1.14C and15N isotopes of urea were infused intravenously into rabbits for 6–8 h in order to measure urea synthesis and the extent of degradation in the digestive tract. The results indicate that 0.62 of the urea flux was excreted in the urine and that re-incorporation of urea-N following hydrolysis in the gut represented 0.3 of the urea synthesis rate.2. Sampling of metabolites from the caecum by dialysis provided an opportunity to assess the contribution of urea-N to the caecal ammonia pool. This contribution is calculated to be 0.25 of caecal ammonia turnover.3. Infusion of a urease (EC3. 5. 1. 5) inhibitor during a continuous infusion of [14C]urea into the caecum permitted the measurement of urea turnover within the caecum.4. Results obtained for urea entry into the caecum are contrasted with the measured urea degradation rate in the gut.