bluuebunny/crossref_metadata_2025_split huggingface dataset:
Net protein utilization determined by rat bioassay of a protein hydrolysate and a diet for children with phenylketonuria
Authors: Kindt Elisabeth , Holm Halvor , Halvorsen Sverre , Lie Sverre O. 
Published: May 2005

1. In a previous study (Kindt et al. 1983, 1984) it was assumed that a protein hydrolysate, devoid of phenylalanine, together with intact protein as given to children with phenylketonuria (PKU), was equivalent to egg or milk protein. One group of children was given this ‘PKU protein’ in amounts corresponding to the Joint FAO/WHO ad hoc Expert Committee (1973) recommendations. The results indicated that the Joint FAO/WHO ad hoc Expert Committee (1973) recommended levels of protein intake were marginal.2. The purpose of the present study was to evaluate whether the quality of the protein hydrolysate, together with intact protein (‘PKU protein’), is equivalent to egg or milk protein. This was done using a rat bioassay. Four protein sources were used: (1) egg protein, (2) protein hydrolysate, (3) protein hydrolysate diluted with non-essential amino acids, (4) protein hydrolysate mixed with food proteins (‘PKU protein’), comparable with the diet previously used (Kindt et al. 1983, 1984).3. The results indicated that the ‘PKU protein’ was of very high qua1ity: net protein utilization (NPU) > 90. The protein hydrolysate alone and the protein hydrolysate diluted with non-essential amino acids gave a NPU > 80.4. The conclusion drawn from the present study is that the ‘PKU protein’, as used in the treatment of children with PKU, is equivalent to egg or milk protein. This supported the view that the Joint FAO/WHO ad hoc Expert Committee (1973) recommended levels of intake were marginal.
Family food purchases and home food consumption: comparison of nutrient contents
Authors: Nelson M. , Dyson P. A. , Paul A. A. 
Published: May 2005

1. Estimates of nutrient intakes based on food purchasing records modelled on the National Food Survey (NFS) were compared with nutrient intakes calculated from food consumption records based on a semi-weighed method, a combination of weighing and household measurement techniques. Of eighty-two families in Cambridge who completed the study, thirty-two were volunteers and fifty were from a random sample in which the co-operation rate was 73%.2. The estimated energy and nutrient contents of the Cambridge food purchases were very similar to those reported by the NFS for families of similar composition and income. The energy intakes obtained by the semi-weighed method were compared with results from twenty-five studies of energy intake based on quantitative measurements of food consumption: there was no evidence to suggest that the semi-weighed method consistently under- or overestimated intakes in the Cambridge subjects.3. Purchases adjusted to allow for waste and consumption of food by visitors contained significantly more energy, protein, carbohydrate, calcium, iron and dietary fibre than measured home food consumption. There was no significant difference in the nutrient content of purchases and consumption per 4.184 MJ (1000 kcal), with the exception of Fe and ascorbic acid.4. Measured wastage of edible food in thirty-one families averaged 3.2% of purchases. Estimate of wastage in all eighty-two families was 3.8%, and consumption of food by visitors accounted for 3.0% of purchases.5. The excess of purchases over measured home food energy intake is probably accounted for by a net increase in larder stocks rather than wastage, consumption of food by visitors, or under-recording of intakes.
Studies of zinc metabolism in pregnant and lactating rats
Authors: Fairweather-Tait Susan J. , Wright A. J. A. , Cooke Jacqui , Franklin J. 
Published: May 2005

1. The metabolism of 65Zn administered intramuscularly (Expt 1) or enterally (Expt 2) at the beginning of pregnancy in rats given a control or marginal-Zn diet was measured. In Expt 2 a comparison was also made between pregnant and non-pregnant rats. The loss of 65Zn (assumed to represent labile body Zn) was markedly reduced in animals fed on a marginal-Zn diet compared with controls, and this effect occurred very rapidly, i.e. within 48 h of introducing the marginal-Zn diet. Pregnancy itself had a much less important effect on 65Zn turnover than diet. Transfer of 65Zn to the litter was significantly greater in the animals fed on a marginal-Zn diet compared with controls but total Zn transfer was reduced.2. The effect of length of time on a marginal-Zn diet on fetal growth and composition was examined. Compared with controls, fetal weight was significantly greater in litters from mothers fed on a marginal-Zn diet during the last 4, 7 or 14 d of pregnancy, but no different in litters from mothers fed on a marginal-Zn diet throughout pregnancy. There were no differences in the proportions of protein or fat in the fetuses from mothers fed on the control or marginal-Zn diets but the Zn concentration was lower in litters from mothers fed on a marginal-Zn diet during part or ail of the pregnancy when compared with controls.3. The transfer of 65Zn from mothers to litters during birth and the first 3 d of lactation was measured. There were no differences in maternal or litter 65Zn just before or just after birth, but within 72 h maternal 65Zn had significantly decreased and litter 65Zn increased. Increases in litter size were associated with greater total litter 65Zn but reduced individual fetal 65Zn.4. These experiments demonstrate the importance of an adequate daily supply of Zn during pregnancy. Although there is room for adaptation to a marginal-Zn intake (by reducing Zn excretion) the maintenance of Zn homeostasis is only possible in the absence of other forms of stress, such as pregnancy, to the body. The consequence of insufficient Zn at times of rapid fetal growth on carbohydrate and lipid metabolism warrants further investigation.
The effect of dietary bagasse on the activities of some key enzymes of carbohydrate and lipid metabolism in mouse liver
Authors: Stanley John C. , Newsholme Eric A. 
Published: May 2005

1. The effects of a 100 g/kg diet substitution of bagasse on the body-weight gain, food consumption and faecal dry weight of mice given a high-sucrose diet and on the activities of hepatic glucose-6-phosphate dehydrogenase (EC1. 1. 1. 49), 6-phosphogluconate dehydrogenase (ECI. I. I. 44), malate dehydrogenase (oxaloacetatedecarboxylating) (NADP+) (ECI. I. I. 40), ATP-citrate (pro-3S) lyase (EC4. 1. 3.8), 6-phosphofructokinase (EC2. 7. 1. II), pyruvate kinase (EC2.7. 1. 40) and fructose-1,6-bisphosphatase (EC3. 1. 3. II) were studied.2. Bagasse had no effect on body-weight gain, food consumption or faecal dry weight.3. Bagasse decreased the activities of glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and phosphofructokinase expressed on a wet weight basis and on a protein basis.4. Bagasse decreased the activities of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydro-genase expressed on a body-weight basis.5. These results suggest that bagasse decreases the flux through some pathways of hepatic lipogenesis when mice are given high-sucrose diets.
Experimental zinc deficiency in guinea-pigs: clinical signs and some haematological studies
Authors: Gupta R. P. , Verma P. C. , Gupta R. K. Paul 
Published: May 2005

1. Thirty-three male, weanling guinea-pigs were divided into two groups. One group was fed on a zinc-deficient (ZnD) diet (1.25 mg Zn/kg diet) for 45 d and then divided into two subgroups: subgroup 1 continued on diet ZnD while subgroup 2 was fed on a Zn-repleted diet (100 mg Zn/kg diet) for 15 d. The second group was fed on a Zn-adequate diet (50 mg Zn/kg diet) for 60 d.2. Zn deficiency could be produced within 21 d as evidenced by clinical signs and reduction in serum Zn concentration.3. Clinical signs exhibited were listlessness, scabby lesions on skin near the foot pads, mild alopecia and a reduction in body-weight gain. No effect was observed on food intake.4. Significant decreases in packed cell volume and total leucocyte count from 48 d onwards accompanied by absolute lymphocytopenia and relative neutrophilia were observed.5. Supplementation of Zn in the Zn-repleted group resulted in marked, though incomplete, improvement with regard to serum Zn concentration, clinical signs and haematological changes.
A comparative study of phytate hydrolysis in the gastrointestinal tract of the golden hamster (Mesocricetus auratus) and the laboratory rat
Authors: Williams P. J. , Taylor T. G. 
Published: May 2005

1. The role of bacterial, dietary and intestinal phytases (EC 3. 1. 3. 8) in the hydrolysis of phytate was investigated in the golden hamster and rat by assaying phytase in the small intestine and by measuring the disappearance of phytate from the stomach and large intestine, using chromium oxide as an insoluble solid-phase marker.2. It was confirmed that an active phytase was present in the proximal third of the small intestine of the rat but the enzyme was undetectable in the hamster.3. Extensive bacterial breakdown of phytate occurred in the pregastric pouch and true stomach of the hamster with both phytase-containing and phytase-free diets, with phytate digestibilities in the true stomach ranging from 0.69–0.90, confirming that the hamster can be regarded as a pseudo-ruminant.4. With a phytase-free diet, the digestibility of phytate in the stomach of the rat was very low (0.05) but with a wheat-based diet substantial breakdown of phytate occurred (digestibility up to 0.49), presumably under the influence of the cereal phytase.5. Intestinal phytase did not appear to be of great significance in the rat but some further hydrolysis of the residual phytate probably occurred in the large intestine of both species by bacterial phytase.
Insulin action and glucose metabolism in sheep fed on dried-grass or ground, maize-based diets
Authors: Janes A. N. , Weekes T. E. C. , Armstrong D. G. 
Published: May 2005

1. The effect of an exogenous supply of glucose, provided by the digestion of maize starch in the small intestine, on endogenous glucose metabolism and insulin action was studied in sheep using the euglycaemic insulin clamp procedure.2. Insulin was infused intravenously at rates of 0.2, 0.5, 1.0 and 6.0 mU/min per kg live weight for four consecutive periods in each of four sheep fed on dried-grass and maize-based diets. Glucose was also infused intravenously at a variable rate, sufficient to maintain the plasma glucose concentration at basal levels. Whole-body rates of glucose metabolism were determined using a continuous infusion of [6-3H]glucose.3. From the resultinginsulin dose-response curves, it was observed that, when the sheep were fed on the dried-grass diet, the responsiveness of glucose metabolism to insulin was less than that reported for non-ruminants.4. When fed the maize-based diet, the glucose metabolic clearance rates (MCR) observed during insulin infusions were significantly greater (P < 0.05) than those observed for the dried-grass diet. However, after correcting for the non-insulin-mediated glucose disposal, differences between diets were not significant.5. The sensitivity of glucose utilization to insulin was not affected by diet. The plasma insulin concentrations causing half-maximal insulin-mediated glucose MCR were 103 (SE 21) and 85 (SE 11) mU/l for the dried-grass and maize-based diets respectively.6. The sensitivity of endogenous glucose production to insulin was also unaffected by diet. The plasma insulin concentrations resulting in the suppression of endogenous glucose production to half the basal level were 80 (SE 26) and 89 (SE 29) mU/l for the dried-grass and maize-based diets respectively.7. It is concluded that the observed increase in glucose utilization on the maize-based diet was due partly to a slight change in responsiveness to insulin and also partly to a change in the rate of non-insulin-mediated glucose disposal.
Estimation of microbial nitrogen in nylon-bag residues by feed15N dilution
Authors: Varvikko T. , Lindberg J. E. 
Published: May 2005

1. Rapeseed (Brussicu nupus), barley grain, ryegrass (Loliurnperenne) and barley straw were labelled with15N as an internal marker. The dilution of15N was used to estimate microbial N (RMN15N) in the feed residues in nylon bags incubated in the rumen for 5, 12 and 24 h. For comparative purposes, diaminopimelic acid (DAP) content of the residues was also determined and rumen microbial N (RMNDAP-N) in the feed residues calculated using DAP as a bacterial marker. The influence of two bag pore sizes (20 μm and 40 μm) with different sample sizes (1 g and 5 g respectively) was also studied.2. For all feeds, the average disappearance of15N was faster than that of total N, the difference between N and15N disappearance being marked with barley, ryegrass and barley straw. The disappearance of microbially corrected dry matter (DM; correction calculated from the15N values) was, accordingly, always faster than the uncorrected DM disappearance. Except for the bag pore/sample size effect for N disappearance, significant (P < 0.01–0.001) feed, pore/sample size and incubation-time effects were always found for the disappearance values.3. Errors (%) resulting from the microbial contamination (calculated from the15N values) in N-loss measurement with rapeseed, barley, ryegrass and barley straw, at 5, 12 and 24 h in 20 μm bags were respectively: –1.8, –3.9, –0.9; –3.8, –22.4, –3.8; –7.2, –4.1, –2.9; –164.5, –146.3, –204.6. In 40 μm bags the corresponding errors were respectively: –4.4, –1.2, –0.7; –26.1, –10.5, –3.9; –13.2, –6.4, –5.5; –221.2, –310.1, –1284.6.4. The largest residual proportions of RMN15N, RMNDAP-Nand DAP-N (% of total N) were found in barley straw, followed by barley, ryegrass and rapeseed, in that order. RMN15N(g/kg residual DM) followed the descending order: barley, ryegrass, straw, rapeseed. RMNDAP-N, (g/kg residual DM) and DAP (mg/kg residual DM) followed the descending order: barley, ryegrass, rapeseed and barley straw. Feed, pore/sample size and incubation-time effects were always significant (P < 0.001).5. With 40 μm bags RMN15Nvalues of barley, ryegrass and barley straw (expressed as % of total N or g/kg residual DM) were substantially higher than those of RMNDAP-NWith 20 μm bags the RMN15Nand RMNDAP-Nvalues were generally quite close for these feeds. With rapeseed residues, RMN15Nwas clearly lower than RMNDAP-Nwith 20 μm bags, but only small differences were found with 40 μm bags.6. A more diverse microbial colonization of feed samples was indicated in the 40 μm bags compared with the 20 μm bags. It was also noticed, consequently, that in most cases larger error resulted from the microbial contamination in 40 μm bags.
Biotin deficiency and susceptibility to fatty liver and kidney syndrome in broiler chicks: reduced 6-phosphofructokinase (EC2.7.1.11) activity but normal fructose 2,6-bisphosphate content in birds with hepatomegaly
Authors: Bannister D. W. , Sales D. I. , Lee Alison 
Published: May 2005

1. In two separate experiments, using different strains, broiler chicks were reared on either a commercial-type chick mash (control) or a fatty liver and kidney syndrome (FLKS)-inducing diet.2. In Expt a, chicks were killed on day 29 and in Expt b, on day 32. Body-weights and liver weights were measured, and values from those given the control ration used to construct a hepatomegaly index by employing a variant of linear discriminant analysis.3. Application of the index to FLKS birds revealed a statistically significant bimodal distribution of liver size.4. The birds with enlarged livers (high index) also possessed metabolic abnormalities in that 6- phosphofructokinase (EC2. 7. 1. 11; PFK-1) activity (measured at low substrate concentration) was depressed despite the presence of normal, or even slightly elevated fructose 2,6-bisphosphate concentration.5. This indicates the presence of an uncharacterized regulatory mechanism for PFK- 1 in FLKS-susceptible birds.
Estimation of the degradability of dietary protein in the sheep rumen by in vivo and in vitro procedures
Authors: Siddons R. C , Paradine J , Gale D. L. , Evans R. T. 
Published: May 2005

1. Estimates of degradability of nitrogen in the sheep rumen for a basal hay diet and for soya-bean meal (SBM), groundnut meal (GNM) and fish meal (FM), when given together with the hay, were determined from measurements of (1) duodenal N flow, (2) ammonia kinetics and (3) rumen N disappearance from polyester bags and rumen outflow rate. The ability of various in vitro procedures to predict in vivo N degradability was also examined.2. Four sheep were given a basal hay diet (800 g dry matter (DM) and 19 g N/d) either alone or supplemented with isonitrogenous amounts (15 g N/d) of SBM, GNM or FM. Duodenal non-ammonia-N flow (g/d) was increased more by FM (8.0) than by GNM (5.9) and SBM (5.8), whilst microbial N flow (g/d) was increased more by SBM (3.9) than by GNM (2.3) and FM (1.6). N degradability values calculated from these results were 0.88, 0.76 and 0.57 for the SBM, GNM and FM respectively. The corresponding value for hay was calculated to be 0.76.3. The irreversible loss of ammonia in the forestomachs (g N/d) was increased more by SBM (11.9) than by GNM (7.2) and FM (5.8) whilst ammonia outflow from the rumen (g N/d) was increased to a similar extent by all supplements ( I.1, 0.9 and 0.8 respectively), as was the amount of microbial N (g/d) synthesized from sources other than rumen ammonia (1.8, 2.0 and 1.9 respectively). N degradability values calculated from these results were 0.84, 0.54 and 0.45 for the SBM, GNM and FM respectively.4. The fractional rate of N disappearance (/h) when the feedstuffs were incubated in polyester bags in the rumen of sheep receiving the basal hay diet (800 g DM/d) was the highest for SBM (0,145) and lowest for FM (0.037), with the hay (0.082) and GNM (0.071) intermediate, whilst the fractional outflow rates from the rumen (/h) of the three supplements were similar (0.034, 0.038 and 0,030 for SBM, GNM and FM espectively). N degradability values calculated from these results were 0.82, 0.67 and 0.60 for the SBM, GNM and FM respectively; the value for the hay was 0.73.5. Of a number of in vitro procedures tested, only N solubility in sodium hydroxide and ammonia or total non-protein-N (NPN) production during incubation with rumen fluid in the absence of hydrazine sulphate ranked the supplements, although not the hay, in the same order as the in vivo degradability procedures. In terms of absolute values, N solubility in NaOH, at room temperature, gave estimates similar to those derived from the duodenal flow measurements; estimates derived from ammonia and total NPN production were lower.
Fatigue corrosion cracking of an austenitic stainless steel using electrochemical noise technique
Authors: Acuña N. 
Published: May 2005

PurposeTo study the early stages of damage by corrosion fatigue (CF) in an austenitic stainless steel using the electrochemical noise (EN) Technique.Design/methodology/approachPotential and current transients measured between two nominally identical electrodes during CF of an UNS S31603 SS were continuously monitored using a zero‐resistance‐ammeter at different periods of exposure to seawater. The tests were carried out under cyclic loading of constant amplitude, stress ratio R=0 and load frequency of ω=0.17 Hz. The analysis was focused on both, crack nucleation sites and short fatigue crack growth, and the correlation between corrosion‐fatigue cracking and characteristics of potential transients and the associated intensity current.FindingsMeasurements of EN, showed a good relationship between the potential transients and current fluctuations with the initiation and growth of inter‐granular corrosion‐fatigue cracks. The amplitude and frequency of potential transients and the intensity of current transients became more intense as the number of loading cycles increased. The initiation of crack events and small crack growth could be associated with the noise patterns with amplitudes of 20 and 70 mV and current density between 0.10 and 0.60 μA cm2; while large inter‐granular crack growth events, were due to coalescence of small cracks, and could be associated with patterns of 200 mV in amplitude and a cathodic current density of 8.0 μA cm2. The crack nucleation sites generally were located at grain boundary triple points on the specimen surface.Originality/valueThe EN Technique can be a good alternative to evaluate the early stages of damage by CF.
Cyclic nitrones as novel organic corrosion inhibitors for carbon steel in acidic media
Authors: Rahman S.U. , Saeed M.T. , Ali Sk.A. 
Published: May 2005

PurposeTo demonstrate corrosion inhibition capabilities of new cyclic nitrones, containing hydrophobic substituents.Design/methodology/approachA number of new cyclic nitrones were synthesized. Corrosion inhibition efficiencies of these organic inhibitors were determined by gravimetric and electrochemical methods, using carbon steel as the substrate metal and 1 M HCl at 60°C as the corrosive environment. Concentration of inhibitor was varied between 50 and 400 ppm.FindingsAll compounds exhibited excellent corrosion efficiencies that ranged between 90.0 and 98.3 percent in 1 M HCl at 60°C. Tafel tests corroborated these results.Research limitations/implicationsThe inhibitors were tested in acidic medium. It is unknown how these inhibitors will function in the presence of other ions that are typically present in natural corrosive environment.Originality/valueAll organic compounds presented in this work are new and this is the first time their corrosion inhibition characteristics have been evaluated.
Bitter melon: an exotic vegetable with medicinal values
Authors: Subratty A.H. , Gurib‐Fakim A. , Mahomoodally F. 
Published: May 2005

PurposeThis article focuses on some of the reported medicinal values of bitter melon, an exotic vegetable forming part of the cuisine of various countries.Design/methodology/approachAvailable data in the literature strongly support the anti‐hypoglycaemic properties of Bitter melon. A literature view was carried out and the data were used to validate our findings regarding the effects of extracts of Momordica charantia on uptake of sugar.FindingsOur work adds on to the growing evidence of the anti‐diabetic properties of bitter melon.Practical implicationsIn view of evidence reported in the literature regarding the medicinal properties of vegetables, the importance of vegetables in a well balanced diet should therefore be strongly advocated.Originality/valueThis paper adds on to the evidence of the use of Momordica charantia as a medicinal plant in traditional medicine in the control of blood sugar level.