bluuebunny/crossref_metadata_2025 huggingface dataset:
Whole-body calorimetry studies in adult men
Authors: Dallosso Helen M. , James W. P. T.
Published: June 2005

1. Eight young men of normal weight were maintained for 1 week on a weight-maintenance diet followed by a 1-week period of over-feeding with extra fat designed to increase energy intake by 50%. Two 36 h calorimetry sessions with low and high physical activities were included in each feeding period. Faecal and urine collections permitted checks on energy malabsorption and nitrogen excretion.

2. Over-feeding led to increases in body-weight, faecal energy and N excretion and in estimated N retention. Faecal energy outputs on the maintenance and over-feeding diets were 5 and 4.4% of the respective gross energy intakes.

3. Energy expenditure on fat over-feeding increased by 5.6% on the low-activity regimen and 6.4% on the high-activity regimen. This amounted, in terms of the extra energy intake, to 9 and 11 % on the inactive and active schedules respectively. The increase affected day- and night-time rates of energy expenditure plus the basal metabolic rate. Individuals with a low percentage body fat showed the greatest response to over-feeding.

4. Nutrient-balance studies derived from calorimetry suggested that fat over-feeding led to substantial fat deposition with no evidence of sparing of carbohydrate oxidation. The theoretical cost of depositing dietary fat was exceeded, suggesting that regulatory thermogenic mechanisms may have been stimulated to a small extent.
Whole-body calorimetry studies in adult men
Authors: Dallosso Helen M. , James W. P. T.
Published: June 2005

1. Studies have claimed that an enhancement of the thermic effect of a meal (TEM) is an important adaptive mechanism to account for energy wastage during over-feeding.

2. Eight healthy normal-weight young men were studied during 1 week on a weight-maintenance diet and again during 1 week when they were over-fed by 50% with fat. During each experimental week, the subject occupied a whole-body indirect calorimeter at 26° for two separate periods of 36 h. The periods differed in the amount of exercise they contained. The thermic responses to the identical meals were measured during rest on one occasion and during exercise on a bicycle ergometer on the other.

3. On the maintenance diet the absolute TEM (kJ/min) was 1.51 (SD 0.42) at rest and 1.31 (SD 0.75) during exercise (no significant difference). The equivalent values (kJ/min) on the over-feeding diet were 2.2 (SD 0.48) and 1.97 (SD 0.64) (no significant difference).

4. The absence of a significant interaction between TEM and exercise was also demonstrated by the fact that the effect of over-feeding on total 24 h energy expenditure was unaffected by the subject's level of physical activity while in the calorimeter.

5. In conclusion, the present study has provided no evidence to support the hypothesis that TEM is enhanced during exercise.
The effect of iron supplements on pregnancy in rats given a low-zinc diet
Authors: Fairweather-Talt Susan J. , Payne Viv , Willians Christine M.
Published: June 2005

1. Female Wistar rats were given an adequate-zinc (60 μg/g) or low-Zn (7 μg/g) diet for a minimum of 2 weeks and then mated. They were then either continued on the same diets (+Zn –Fe or –Zn –Fe) or given similar diets supplemented with four times the normal level of iron (+Zn + Fe or –Zn + Fe). The day before parturition they were killed and the fetuses removed and analysed.

2. There were no differences in numbers of fetuses or the number of resorption sites. In the absence of Fe supplementation, the mean fetal wet weight was significantly less (P< 0.05) in the low-Zn group but there was no effect of Zn in the two Fe-supplemented groups. The addition of Fe significantly decreased (P< 0.05) the mean fetal wet weight in the adequate-Zn groups but had no effect in the low-Zn groups. There were no differences in fetal dry weight, fat, protein or DNA content. Both Fe-supplemented groups produced fetuses of higher Fe concentration (P< 0.01), and mothers with higher bone Fe-concentration (P< 0.01) compared with the non-supplemented groups. The low-Zn groups produced fetuses of lower Zn concentration (P< 0,001) than the adequate-Zn groups but there was no effect on maternal bone Zn concentration.

3. It was concluded that Fe-supplements did not adversely affect fetal growth from mothers given a low-Zn diet, but the addition of Zn to the unsupplemented diet increased fetal wet weight. These findings were not accompanied by any other differences in fetal composition or dry weight, and do not therefore lend support to the suggestion of an Fe-Zn interaction.
The yield and nutrient content of colostrum and milk of women from giving birth to 1 month post-partum
Authors: Saint L. , Smith Margaret , Hartmann P. E.
Published: June 2005

1. The intake of mammary secretion from delivery to day 5 post-partum was determined by test-weighing nine infants using an integrating electronic balance. The mean yield of colostrum for the first 24 h after birth was 37.1 (range 7.0–122.5) g and was 408 (range 98.3–775) and 705.4(range 452.5–876)g/24h on days 3 and 5 post-partum respectively.

2. The milk yield of mothers on either day 14 or 28 post-partum was determined by test-weighing the mother. The mean milk yield was 1.156 (SD 0.167) kg/24 h.

3. A significant correlation (P < 0.001; r 0.85, n 42) was found between milk yield measured by test-weighing the infant and milk yield measured by test-weighing the mother, confirming that it is possible to obtain a similar estimate of milk consumed using either of the two methods of test-weighing

4. There was a significant positive correlation (P < 0.001) between lactose concentration and milk yield for the first 5 d post-partum (r 0.76, n 22); a significant negative correlation (P < 0.001) between protein concentration and milk yield (r – 0.74, n 22) and no significant correlation between fat concentration and milk yield for the period studied.

5. The calculated energy intake of infants during the first 24 h after birth was only 0.12 (range 0.02–0.29) mJ. This increased to 1.44 (range 0.83–2.18) and 2.99 (range 2.49–4.06) mJ/24 h by days 3 and 14–28 post-partum respectively.
Effect of guar gum on body-weight, hunger ratings and metabolism in obese subjects
Authors: Krotkiewski Marcin
Published: June 2005

1. The effect of a palatable granulated guar-gum preparation (10 g twice daily) was studied in obese subjects. The acute effect of a single dose of guar gum to reduce the peak postprandial whole blood glucose levels (about 10%) was verified. Following long-term treatment, a further reduction was seen in the obese subjects with the highest postprandial glucose levels. Since the postprandial plasma insulin levels were essentially unchanged, this finding suggested an increased responsiveness to insulin. Total serum cholesterol levels were significantly reduced following long-term treatment but serum α-cholesterol levels, representing the high-density-lipoprotein fraction, was unchanged.

2. Body-weight was significantly reduced during guar-gum treatment even though the patients were asked to maintain their normal dietary habits. Daily hunger ratings recorded for up to 10 weeks showed that guar gum reduced hunger significantly better than commercially available bran taken in the same way.

3. Thus, guar gum seemed to influence carbohydrate and lipid metabolism in a beneficial way in obese subjects. The reduction in hunger would offer an additional benefit to these patients.
Vitamin A metabolism in chick liver: some properties of the cytosolic lipid–protein aggregate
Authors: Sklan D. , Halevy Orna
Published: June 2005

1. Incubation of hepatic microsomes with retinol resulted in formation of retinyl esters and glucuronides. The presence of the cytosolic lipid-protein aggregate (LPA) in the system in addition induced release of holoretinol-binding protein from the microsomes. The extent of these reactions was influenced by the addition of coenzyme A and ATP, or uridine diphosphate glucuronic acid.

2. Incubation of hepatic microsomes containing labelled retinyl esters with the LPA resulted in the appearance of the labelled retinyl esters in the LPA.

3. Small amounts of retinoic acid were formed on incubation of retinol with microsomes (approximately 1% of added retinol); this was found to be associated with a protein of approximately 14500 molecular weight, and less than 10% was associated with the LPA. This is in contrast to retinol, which was found to be almost completely associated with the LPA.

4. The cytosolic LPA was associated both with carotene-cleavage activity and alcohol dehydrogenase (NAD(P)+) (EC1. 1. 1. 71) activity.

5. These findings lend some support to the concept of a specific role for hepatic LPA.
The effect of dietary lysine levels on growth and metabolism of rainbow trout (Salmo gairdneri)
Authors: Walton M. J. , Cowey C. B. , Adron J. W.
Published: June 2005

1. Groups of rainbow trout (Salmo gairdneri; mean weight 5 g) were given diets containing 10, 12, 14, 17, 21, 24 and 26 g lysine/kg diet for 12 weeks.

2. By analysis of the growth values the dietary requirement of lysine in this experiment was found to be 19 g/kg diet. A similar requirement value was obtained from a dose-response curve of expired14CO2(following an intraperitoneal injection of L-[U-14C]lysine) v. dietary lysine concentration.

3. Liver concentrations of total lipid and carnitine and activities of lysine-α-ketoglutarate reductase (saccharopine dehydrogenase (NADP+, lysine-forming),EC1. 5. 1. 8 ) in the liver were not significantly different in fish from the different dietary treatments. Hepatosomatic index, however, was higher in those fish given low levels of dietary lysine.
Hepatic lipogenesis in young rats given proteins of different quality
Authors: Herzberg G. R. , Rogerson Minda
Published: June 2005

1. The effect of feeding casein, lactalbumin, soya-bean protein, gluten or gelatin on hepatic lipogenesis and the levels of hepatic fatty acid synthetase (FAS), glucose-6-phosphate dehydrogenase (EC 1. 1. 1.49; G6PD), malic enzyme (EC1. 1. 1.40; ME) ATP-citrate lyase (EC4. 1. 3. 8; CL), acetyl CoA carboxylase (EC6.4.1.2; ACCx) and glucokinase (EC2. 7. 1. 2; GK) was examined in young growing rats.

2. The total activities of ACCx, FAS, CL, GK, G6PD, GK, ME and fatty acid synthesis in vivo were positively correlated with protein quality.

3. The specific activities of ACCx, FAS, CL, G6PD and fatty acid synthesis in vivo were positively correlated with protein quality.

4. The specific activities of GK and ME were unrelated to protein quality.

5. The results demonstrate a dissociation between ME and hepatic lipogenesis and suggest a role for the NADPH generated by ME which is not related to the needs of fatty acid synthesis.
Effects of cooling in infant rats on growth, maturation, sleep patterns and responses to food deprivation
Authors: Swanson Heidi H. , Bolwerk Eric , Brenner Eli
Published: June 2005

1. The confounding effects of undernourishment and body cooling, resulting from maternal separation, were investigated by separating food and warmth deprivation. Rat pups aged 3–16 d were deprived of food for alternate 24-h periods by removal from the lactating mother. Some of the pups were placed with a foster mother, who kept them warm, whereas others were put in an empty cage at 22° which resulted in a sharp drop in body temperature.

2. Pups which were kept warm showed great fluctuations in weight between periods of starvation and feeding. The cooled pups lost less weight during deprivation but also recovered less on refeeding.

3. The resultant growth rate was much lower in non-fostered (i.e. cooled) than in fostered pups.

4. Up to the age of 8 d, cooled pups failed to raise their body temperature above that of the surroundings and did not digest the milk in their stomachs. Although, thereafter, they were able to raise their temperature to 26° and to digest stomach contents, the extra energy expended resulted in more severe growth restriction.

5. One-third of the pups died at 16 d but the rest were quickly rehabilitated by ad lib. feeding and showed a normal growth rate, although they remained smaller than the controls.

6. The development of nipples, hair, eye opening and vaginal opening was related more to chronological age than to weight.

7. A side effect of cooling was an almost complete abolition of active (REM) sleep, which is normally very high in infants; a slight rebound increase in active sleep was seen at 21 d. Direct as well as side effects of cooling may thus be responsible for some of the observed consequences of maternal separation.
Some studies on the metabolism and the effects of 99Mo- and 35S-labelled thiomolybdates after intravenous infusion in sheep
Authors: Hynes Miriam , Lamand M. , Montel G. , Mason J.
Published: June 2005

1. Sheep were infused intravenously with 88Mo- and 35S-labelled tri- and tetrathiomolybdates (1–2 mg Mo).

2. Most of the plasma radioactivity was trichloroacetic acid (TCA)-insoluble after infusion, but the stability of this fraction was reduced by pre-infusion or subsequent infusion with unlabelled thiomolybdates. Most of the 88Mo and 35S was shown to be associated with albumin.

3. It was concluded that compounds bound to albumin were relatively stable, but displaced or unbound thiomolybdates were rapidly hydrolysed to molybdate and sulphate.

4. There was no evidence of an irreversible interaction of either 35S or 88Mo with copper in plasma, despite the appearance of a TCA-insoluble Cu fraction. Increased dietary Cu did not increase the retention of 35S in plasma or affect the exchangeability of 35S-labelled thiomolybdates bound to albumin.
Thermogenic drugs for the treatment of obesity: sympathetic stimulants in animal models
Authors: Dulloo A. G. , Miller D. S.
Published: June 2005

1. Thirty-three drugs known to stimulate the sympathetic nervous system have been screened for thermogenic properties. The results presented are for seven of them.

2. The drugs were tested in five animal models of obesity (genetic (mice and rats), hypothalamic (mice) and dietary (mice and rats)) as well asin leanmice. Energy-balance studies were undertaken using thecomparative-carcass technique as well as by measurement of daily oxygen consumption.

3. All seven drugs in obese animals tended to reduce body-weight and fat without loss of body protein: they acted by increasing metabolic rate without increasing food intake. They were much less effective in lean animals. These findings lend support to the concept that obesity is due to a diminished activity of the sympathetic nervous system.

4. Differences in the effectiveness of the drugs are discussed in relation to differences between the animal models of obesity. Ephedrine and tranylcypromine were found to be the most effective drugs in this series of experiments and a prima facie case is made for human clinical trials.
Does guar gum improve post-prandial hyperglycaemia in humans by reducing small intestinal contact area?
Authors: Blackburn N. A. , Holgate A. M. , Read N. W.
Published: June 2005

1. The possibility that viscous polysaccharides, such as guar gum, could lower post-prandial blood glucose levels in part by restricting carbohydrate solutions to a smaller area of small intestine was investigated in twenty healthy human volunteers.

2. Addition of guar gum (22.5 g/l) delayed the mouth-to-caecum transit time of a hypotonic lactulose drink, but did not affect gastric emptying.

3. When a 250 ml solution containing 50 g glucose was confined to a 550 mm length of intestine by an occluding balloon attached to an intestinal tube, maximum blood glucose response was significantly reduced (P < 0.05) though only by 0.9 mmol/l.

4. Addition of guar gum (36 g/l) had no effect on the distribution of a radio-labelled glucose drink (250 ml; 200 g glucose/l) in the small intestine, monitored using a gamma camera, although it significantly delayed gastric emptying (t½ (min): guar gum v. control 115 (SE 15) v. 73 (SE 8)).

5. Reduced contact area is unlikely to be one of the mechanisms by which guar gum improves glucose tolerance.
Zinc metabolism in pregnant and lactating rats and the effect of varying iron: Zn in the diet
Authors: Fairweather-Tait Susan J. , Wright A. J. A. , Williams Christine M.
Published: June 2005

1. Pregnant rats were given control (46 mg iron/kg, 61 mg zinc/kg), low-Zn (6.9 mg Zn/kg) or low-Zn plus Fe (168 mg Fe/kg) diets from day 1 of pregnancy. The animals were allowed to give birth and parturition times recorded. Exactly 24 h after the end of parturition the pups were killed and analysed for water, fat, protein, Fe and Zn contents and the mothers' haemoglobin (Hb) and packed cell volume (PCV) were measured.

2. There were no differences in weight gain or food intakes throughout pregnancy. Parturition times were similar (mean time 123 (SE 15) min) and there were no differences in the number of pups born. Protein, water and fat contents of the pups were similar but the low-Zn Fe-supplemented group had higher pup Fe than the low-Zn unsupplemented group, and the control group had higher pup Zn than both the low-Zn groups. The low-Zn groups had a greater incidence of haemorrhaged or deformed pups, or both, than the controls.

3. Pregnant rats were given diets of adequate Zn level (40 mg/kg) but with varying Fe:Zn (0.8, 1.7, 2.9, 3.7). Zn retention from the diet was measured using65Zn as an extrinsic label on days 3, 10 and 17 of pregnancy with a whole-body gamma-counter. A group of non-pregnant rats was also included as controls. The65Zn content of mothers and pups was measured 24–48 h after birth and at 14, 21 and 24 d of age.

4. In all groups Zn retention was highest from the first meal, fell in the second meal and then rose in the third meal of the pregnant but not the non-pregnant rats. There were no differences between the groups given diets of varying Fe:Zn level. Approximately 25% of the65Zn was transferred from the mothers to the pups by the time they were 48 h old, and a further 17% during the first 14 d of lactation. The pup65Zn content did not significantly increase after the first 20 d of lactation but the maternal65Zn level continued to fall gradually.
Growth and development of rats artificially reared on different milk-substitutes
Authors: Smart J. L. , Stephens D. N. , Tonkiss J. , Auestad N. S. , Edmond J.
Published: June 2005

1. Rat pups were artificially reared (AR) from postnatal day 4 or 5 till day 20 or 21, by fitting them with gastric cannulas through which milk-substitutes could be infused automatically.

2. Three milk-substitutes were compared: milk M, the usual diet for AR studies, which was somewhat low in protein and very high in carbohydrate; milk A, which resembled rats' milk much more closely in composition; and milk isoM, which was based on the high-energy milk M but was made isoenergetic with milk A. Pups given these diets were termet ARM, ARA and ARisoM respectively. Siblings of the AR rats were left with their mothers to form a mother-reared (MR) control group. Rats were autopsied at 20 or 21 d.

3. Growth in body-weight of all groups of AR pups lagged behind that of their MR siblings for about the first week of AR, but the ARM group showed complete catch-up and the ARA group partial catch-up in body-weight during the second week. ARisoM rats were growth-retarded throughout.

4. Inspection of organ weights expressed relative to body-weight revealed disturbances of organ growth in all AR groups compared with MR animals. ARM rats showed excessive epididymal fat pad and liver weights, but deficits in gastrocnemius muscle, heart and adrenal weights. In contrast, ARA rats usually displayed increased spleen and stomach weights, but lower weight of interscapular brown adipose tissue. ARisoM rats had high brain, liver and stomach weights and low muscle and spleen weights relative to body-weight. All AR groups had elongated small intestines.

5. Hence the patterns of abnormal organ growth differed between groups. Those shown by the ARM and ARisoM groups seemed the more seriously abnormal. The diet approximating the composition of rats' milk (milk A) appears, as intended, to be an improved milk-substitute.
Nutritional availability of amino acids from protein cross-linked to protect against degradation in the rumen
Authors: Ashes John R. , Mangan Jim L. , Sidhu Gurcharn S.
Published: June 2005

1. Casein was labelled with pairs of radioactive amino acids, lysine, tyrosine and leucine, one with I4C and the other with 3H, by jugular infusion into lactating goats followed by isolation of the double-labelled casein from the milk. Total milk protein was similarly labelled by jugular infusion of [35S]cystine. U-14C-labelled fraction- 1 leaf protein was isolated from lucerne (Medicago sativa) grown in an atmosphere of 14C02

2. The proteins were treated withdifferent levels(333 and667 mmol/kgprotein) offormaldehyde, glutaraldehyde and glyoxal.

3. Absorption from the small intestine was measured in sheep with fistulas in the abomasum and terminal ileum, using Cr-EDTA as the digesta flow marker, by introducing radioactive casein into the abomasum.

4. Lysine, tyrosine and cystine became increasingly unavailable for absorption from the small intestine of sheep with increasing levels of aldehyde. At the lower level (333 mmol/kg) the proportions of the amino acids that were unavailable were 0.192, 0.051 and 0.123 respectively. At the higher level of formaldehyde (667 mmol/kg) the corresponding values were 0.335, 0.201 and 0.432 respectively. Leucine was not made unavailable with formaldehyde.

5. The proportions of lysine, tyrosine and leucine that were unavailable were higher, on a molar basis, after treatment of the proteins with the dialdehydes glutaraldehyde and glyoxal than after treatment with formaldehyde. However, the extent of protein protection provided by the dialdehydes in the rumen, measured using an in vitro procedure, was lower.
Microbial protein synthesis in cattle given roughage–concentrate and all-concentrate diets: the use of 2,6-diaminopimelic acid, 2-aminoethylphosphonic acid and 35S as markers
Authors: Whitelaw F. G. , Eadie J. Margaret , Bruce L. A. , Shand W. J.
Published: June 2005

1. Three steers, each fitted with a rumen cannula and a re-entrant cannula in the proximal duodenum, were offered diets consisting of a barley-based concentrate and chopped hay at a daily intake of 61 g/kg live weight0-75 given in three. equal meals. The ratio, concentrate: hay was changed from 50: 50 to 90: 10 and then to 100: O in successive periods of 12–18 weeks and the flow and composition of digesta at the duodenum was measured over 48-h periods on each dietary treatment.

2. Samples of bacteria and protozoa were separated from rumen contents and the proportions of bacterial and protozoal nitrogen (N) in duodenal digesta were estimated using 2, ddiaminopimelic acid (DAPA) and 2- aminoethylphosphonic acid (AEP) as markers. On separate occasions, radioactive sulphur (35S) was infused into the rumen for 48 h and digesta collected over the final 24 h; the specific radioactivity of S in microbial and digesta fractions was used to estimate the proportions of microbial N.

3. 35S gave reproducible and apparently reliable estimates of microbial protein formation: the proportion of microbial N in digesta was significantly higher (P < 0.05) for the 50:50 diet than for the other treatments but the energetic efficiency of microbial protein formation did not differ significantly between diets.

4. Estimatesof bacterial N based on DAPA concentrations were highly variable and frequently impossibly high. It is suggested that many of the anomalous values were the result of non-representative sampling of the rumen microbial population and that this is particularly likely to occur when conditions within the rumen are unstable. AEP was found to be unsuitable as a marker for rumen protozoa as considerable concentrations of this substance were found also in rumen bacteria.
Methane formation in faunated and ciliate-free cattle and its relationship with rumen volatile fatty acid proportions
Authors: Whitelaw F. G. , Eadie J. Margaret , Bruce L. A. , Shand W. J.
Published: June 2005

1. Twelve steers fitted with rumen cannulas were used in three separate experiments to investigate the effects of the presence or absence of rumen ciliate protozoa on methane production. The diet consisted of 850 g barley and 150 g protein supplement/kg, and was given in three feeds daily at a restricted level of 61 g/kg live weight0.75. Animals were defaunated initially by allowingad lib. consumption of this diet and were then maintained ciliate-free by isolation or were faunated by inoculation with a mixed ciliate suspension. Samples of rumen fluid were taken routinely for the assessment of microbial populations and for volatile fatty acid (VFA) analysis and energy and nitrogen balances and digestibility measurements were made at intervals while animals were confined in respiration chambers.

2. In each experiment the rumen VFA proportions changed from a high-propionate pattern under ciliate-free conditions to a low-propionate, high-butyrate pattern in the presence of ciliates: differences between treatments were highly significant (P < 0.001). There were also marked differences between treatments in CH, production but a reliable comparison was possible only in Expt 3, in which CH4was significantly higher (P < 0.001) in the presence of a rumen ciliate population. In Expt 3 the increased loss of energy as CH4in the faunated animals amounted to 44 MJ/100 MJ energy intake.

3. Stoichiometric estimates of CH4production derived from the observed VFA proportions showed good agreement with CH4production as measured in respiration chambers. On average, the stoichiometric CH4values overestimated CH4production by a factor of 1.08.

4. Highly significant linear relationships (P < 0.001) were observed between the molar proportion of each major VFA and the quantity of CH4produced: the proportion of propionic acid was inversely related to CH4and showed the lowest residual standard deviation of all the relationships examined.

5. The losses of energy in faeces and urine did not differ between treatments hence the increased loss of energy as CH4in the faunated animals resulted in a significant reduction in the metabolizability of the diet from 0.73 to 0.69 (P < 0.05). No significant differences were detected between treatments in heat production, apparent digestibility coefficients or N balance.

6. It is suggested that the rumen ciliates, by modifying the rumen VFA proportions, are directly responsible for the increased CH4production in faunated animals.
Glucose turnover and recycling in unrestrained and unanesthetized 48-h-old fasting or post-absorptive newborn pigs
Authors: Pégorier Jean-Paul , Duée Pierre-Henri , Nunes Carlo Simoes , Peret Jean , Girard J.
Published: June 2005

1. The metabolism of glucose has been studied in 48-h-old unanesthetized fasting and post-absorptive sucking piglets.

2. Both [6-3H]- and [U-14CJglucose were administered either by a single injection method or by a primed infusion technique. The rates of glucose turnover and recycling were estimated under steady-state conditions.

3. The rates of glucose turnover and recycling in 48-h-old fasting or post-absorptive piglets were not statistically different when measured using the single injection technique or the printed infusion method.

4. The mean (with SE) rate of glucose turnover was 65.8 (2.5) in post-absorptive and 31.1 (1–9), μ mol/kg per min in fasted newborn pigs. Glucose utilization was linearly related to blood glucose concentration; regression analysis indicated a y-intercept of 7.2, μ mol/kg per min.

5. As tested by arterio-portal differences the gut was not releasing glucose or galactose in 5 h-post-absorptive sucking newborn pigs. Thus, the higher rates of glucose turnover in post-absorptive newborn pigs compared with fasting ones suggest that hepatic glucose production is enhanced in post-ahsorptive sucking piglets.

6. The mean (with SE) rates of glucose recycling were four times higher in post-absorptive piglets than in tasting ones, i.e. 14.4 (1.6) and 3.7 (0.5)% of [6-3H] glucose turnover respectively. As liver glycogen was exhausted in 48-h-old sucking piglets, this suggests that hepatic glucose production results from gluconeogenesis.
Response of male and female rats to undernutrition
Authors: Harris Patricia M. , Broadhurst R. B. , Hodgson Diane F.
Published: June 2005

1. Female Wistar rats (5 and 11 weeks old) were either left intact or ovariectomized. Animals of each age- and treatment-group were either ad lib.-fed or undernourished for 4 weeks.

2. The bodies of all animals were analysed for protein and fat and the weights, lipid synthesis rate and lipoprotein lipase (EC 3.1. 1.34) activity of four fat depots were determined.

3. The well-nourished ovariectomized animals of both age-groups gained weight more rapidly than the well-nourished intact animals of the same age, but there was no effect of ovariectomy on body composition, lipid synthesis rate or lipoprotein lipase activity in either the well-nourished or the undernourished animals of either age-group.

4. There was a greater efficiency of energy utilization found in the ovariectomized animals than in the intact animals regardless of age or nutritional status.
The effect of abomasal infusion of casein on acetate, palmitate and glucose kinetics in cows during early lactation
Authors: Köning Barbara A. , Oldham J. D. , Parker D. S.
Published: June 2005

1. Four mature Friesian cows were used in a Latin square design experiment to measure the effects of abomasal casein infusion on milk production and the kinetics of glucose, acetate and palmitate in jugular venous blood.

2. The basal ration contained 110 g crude protein/kg dry matter and was offered at the rate of 4 kg hay, 3 kg alkali-treated straw cubes plus 9 kg concentrates/d. Treatments were infusion of casein into the abomasum at the rate of 0, 240 or 460 g/d. The experiment started 1 week post partum. Experimental periods lasted 21 d.

3. [6-3H]glucose, [9, 10-3H]palmitate and [U-14C]acetate were continuously infused into one jugular vein for measurements of whole-body flux rates.

4. The yield of milk protein was increased significantly (P < 0.05) by the first increment of casein infusion, with no further increases.

5. Casein infusion had no effect on blood concentrations of glucose, acetate, palmitate or growth hormone. Mean flux rate of glucose increased with each increment of casein. The effect at 460 g/d was higher (P < 0.1) than with no infusion. Flux rates of palmitate and acetate were increased (P< 0.1) by the first increment of casein. The proportion of blood bicarbonate derived from acetate increased (P < 0.05) with the first increment of casein.

6. Protein status of cows early in lactation influences the dynamics of glucose and fatty acid metabolism.
Insulin response to glucose and glucose tolerance following feeding in sheep
Authors: Sasaki Y. , Takahashi H. , Aso H. , Hikosaka K. , Hagino A. , Oda S.
Published: June 2005

1. Sheep offered a roughage diet for 4 h daily were injected intravenously with glucose before and at various times after feeding. The insulin secretory response to glucose and the rate of disappearance of injected glucose were determined.

2. While the basal concentration of plasma insulin was unchanged, the base-line plasma glucose concentration tended to decrease during the meal.

3. The glucose load brought about an increase in the plasma insulin concentration at each injection, but the insulin response to glucose and the rate of glucose disposal were increased during the meal.

4. On varying the time of feeding between 08.00 and 16.00 hours, the increase in the insulin response to glucose and in the rate of glucose disposal always appeared to be related to the giving of food, independent of the time food was offered.

5. It is concluded that feeding increases the insulin response to an intravenous glucose load even when the increase in the basal level of plasma insulin on feeding is very modest in sheep given a roughage diet. The increased insulin response and glucose disposal rate following feeding did not appear to be related to diurnal rhythms in insulin secretory activity or glucose metabolism.
Whole body and tissue fractional protein synthesis in the ovine fetusin utero
Authors: Schaefer A. L. , Krishnamurti C. R.
Published: June 2005

1. Whole-body and tissue fractional protein synthesis rates were determined in chronically-catheterized ovine fetuses at 120–130 d of gestation following an 8 h continuous infusion of L-[U-14C]-or L-[2, 3, 5, 6-3H]tyrosine.

2. From the net utilization of tyrosine by the fetus, corrected for apparent oxidation, and tyrosine concentration in the fetal carcass protein, whole-body protein synthesis was estimated to be 63 g/d per kg.

3. Following 8 h of infusion of labelled tyrosine the ewes were killed and fetal tissues were removed for the determination of tyrosine specific activity. The fractional rate of protein synthesis (k3) was calculated from the specific activity ratio, protein bound: intracellular free tyrosine. Tissue k, values for the liver, kidney, lungs, brain, skeletal muscle and small intestine were 78, 45, 65, 37, 26 and 93% /d respectively.

4. The absolute rate of synthesis was calculated by multiplying the tissue protein content by k2. Muscles, gastrointestinal tract, liver and lungs contributed approximately 20.5, 20.5, 14.4 and 9.4% respectively to whole- body protein synthesis.

5. The efficiency of protein synthesis as expressed by the RNA activity was higher in liver, lung and brain followed by kidney, skeletal and cardiac muscle.
Hexose transport and mucosal morphology in the small intestine of the zinc-deficient rat
Authors: Southon Susan , Gee Jennifer M. , Johnson I. T.
Published: June 2005

1. Immature male Wistar rats were given a zinc-depleted semi-synthetic diet (2 mg Zn/kg diet) for 4 weeks. Control groups received a similar diet containing 60 mg Zn/kg diet, either ad lib. or in amounts matched to the consumption of the Zn-deficient group. Rates of growth and food conversion efficiency were markedly lower in the Zn-deficient group compared to controls.

2. The phloridzin-sensitive uptake of galactose and 3-0-methyl glucose by everted jejunal rings from each group was measured over a range of concentrations. Kinetic analysis revealed that the maximum transport rate (Vmax)for the uptake of both sugars was significantly higher in the Zn-deficient group than in the control groups.

3. The villi, microdissected from samples of proximal jejunum, were significantly shorter and narrower across the base in the Zn-deficient group than those of the control groups, but were present in greater numbers per unit serosal area.

4. The present study shows that Zn deficiency leads to significant morphological changes in rat small intestine, which are accompanied by an increase in the capacity of the tissue to take up sugars across the mucosal membrane.
The physical digestion of perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) in the foregut of sheep
Authors: Moseley G. , Jones J. R.
Published: June 2005

1. Sheep were fed once daily with 300 or 600 g dried perennial ryegrass (Lolium perenne) or white clover (Trifolium repens). Total rumen contents were sampled once daily at various intervals up to 24 h after feeding for 6 d.

2. Total weight of fresh rumen contents and dry matter (DM), organic matter and particulate matter concentrations were measured and the particle size distribution of rumen contents was analysed using a wet sieving technique.

3. There was a similar exponential loss of DM from the rumen with time after feeding for both perennial ryegrass and white clover. The rate of DM disappearance during the first 3 h after feeding was ten times greater for the higher intake and seven times greater for the lower intake than during the subsequent 21 h. The percentage of particulate material disappearingduring the first 3 h was greater for white clover (57% )than for perennial ryegrass (49%).

4. Particle size distribution analysis of rumen contents showed that the most rapid rate of particle size reduction occurred during the first 3 h after feeding. Despite a rapid rate of breakdown there was no increase in the total weight of small particles in the rumen.

5. The rate of reduction in particle size during this period was greater for white clover than perennial ryegrass.

6. Microscopic examination of rumen particles showed a difference in particle geometry between white clover and perennial ryegrass which appeared to be related to anatomical features of the plant.
The effect of formaldehyde or glutaraldehyde application to lucerne before ensiling on silage fermentation and silage N digestion in sheep
Authors: Siddons R. C. , Arricastres C. , Gale D. L. , Beever D. E.
Published: June 2005

1. The primary growth of lucerne (Medicago sativa) was ensiled after treatment with either formic acid alone (4.1 litres/t; silage F) or with formic acid and either formaldehyde (30.5 g/kg crude protein (nitrogen x 6.25; CP); silage FF), glutaraldehyde (44.2 g/kg CP; silage FG) or a mixture of the two aldehydes at approximately half their individual application rates (silage FFG).

2. Compared with formic acid alone, both formaldehyde and glutaraldehyde reduced protein breakdown and carbohydrate fermentation during ensiling. The extent of protein protection afforded within the silo was similar for the two aldehydes, whereas formaldehyde was more effective in restricting carbohydrate fermentation. The effect of treatment FFG on silage fermentation was confounded by the silo bag bursting and the development of a clostridial-type fermentation. All aldehyde treatments reduced silage soluble-N content but N disappearance when the silages were incubated in polyester bags in the rumen was high for all silages and reductions due to the aldehydes were small.

3. Silage digestion was studied in four mature sheep each fitted with a rumen cannula and re-entrant cannulas in the proximal duodenum and distal ileum.

4. The apparent digestibility of organic matter (OM) in the whole tract was reduced (P < 0.05) to a similar extent by both aldehydes, whereas rumen OM digestion was reduced (P < 0.05) more by glutaraldehyde than by formaldehyde. The effects on digestion appeared to be due to the action of the aldehydes on the foods rather than to any adverse influences of the aldehydes on the metabolism of the rumen microbes because, although rumen ammonia levels were lower (P < 0.05) when the aldehyde-treated silages were given, rumen casein-degrading activity, the degradation of different feedstuffs when incubated in polyester bags in the rumen and microbial N flow at the duodenum did not differ (P < 0.05) between silages.

5. All aldehyde treatments decreased (P < 0.05) the apparent digestibility of N in the whole tract. Silage N degradability in the rumen was also decreased (P < 0.05) from 0.82 for silage F to 0.67, 0.60 and 0.62 for silages FF, FG and FFG respectively, and consequently non-ammonia-N (NAN) flow at the duodenum increased (P < 0.05). The aldehydes did not adversely affect the apparent digestibility of NAN in the small intestine, and net NAN absorption from the small intestine increased from 8.8 g/d with silage F to 11.4, 15.3 and 14.2 g/d with silages FF, FG and FFG respectively. Both the decrease in N degradability in the rumen and the increase in net NAN absorption from the small intestine were greater (P < 0.05) with glutaraldehyde than with formaldehyde.
Absorption of electrolytes and volatile fatty acids in the hind-gut of the rabbit. Circadian rhythm of hind-gut electrolytes and plasma aldosterone
Authors: Vernay Michele , Marty Josetta , Moatti Jean-Pierre
Published: June 2005

1. Interrelationships between the amount of water, solute concentrations in the hind-gut, plasma aldosterone concentrations, and the excretory cycle in the rabbit were studied as well as the effects of hormones generally implicated in electrolyte regulation.

2. It appeared that the levels of water, electrolytes and volatile fatty acids (VFA) in the large intestine varied cyclicly with the excretion pattern: during the soft-phase, water, sodium, chloride and VFA were absorbed and potassium secreted as in other mammals; during the hard-phase two opposite phenomena occurred: secretion in the ascendant colon and absorption in the rest of the colon. Absorption of water, Na, K, chloride and VFA was increased and by this means only material without nutritional value was lost.

3. Plasma levels of aldosterone showed a circadian rhythm parallel to hind-gut changes, i.e. the higher values were found during the hard-phase. Exogenous aldosterone enhanced secretive and absorptive processes, which occurred normally when hard faeces were elaborated.
Effects of semi-starvation and potassium deficiency on the concentration of [3H]ouabain-binding sites and sodium and potassium contents in rat skeletal muscle
Authors: Kjeldsen Keld , Everts Maria Elisabeth , Clausen Torben
Published: June 2005

1. Using vanadate-facilitated [3H]ouabain binding, the effect of semi-starvation on the total concentration of [3H]ouabain-binding sites was determined in samples of rat skeletal muscle. When 12-week-old rats were semi-starved for 1, 2 or 3 weeks on one-third to half the normal daily energy intake, the [3H]ouabain-binding site concentration in soleus muscle was reduced by 19, 24 and 25% respectively. In extensor digitorum longus, diaphragm and gastrocnemius muscles the decrease after 2 weeks of semi-starvation was 15, 18 and 17% respectively. The decrease was fully reversible within 3 d of free access to the diet. Complete deprivation of food for 5 d caused a reduction of 25% in soleus muscle [3H]ouabain-binding-siteconcentration. It was excluded that the reduction in [3H]ouabain binding was due to a reduced affinity of the binding site for [3H]ouabain.

2. Semi-starvation of 12-week-old rats for 3 weeks caused a reduction of 45 and 53% in 3, 5, 3'-triiodothyronine (T3) and thyroxine (T4) levels respectively. As reduced thyroid hormone levels have previously been found to decrease [3H]ouabain-binding-siteconcentration in skeletal muscle, this points to the importance of T3and T4in the down-regulation of the [3H]ouabain-binding-siteconcentration in skeletal muscle with semi-starvation. Whereas potassium depletion caused a decrease in K content as well as in [3H]ouabain-binding-siteconcentration in skeletal muscles, semi-starvation caused only a tendency to a decrease in K content. Thus, K depletion is not a major cause of the reduction in [3H]ouabain-binding-siteconcentration with semi-starvation.

3. Due to its high concentration of Na, K pumps, skeletal muscle has a considerable capacity for clearing K from the plasma as well as for the binding of digitalis glycosides. Semi-starvation causes a severe reduction in the total skeletal muscle pool of Na, K pumps and may therefore be associated with impairment of K tolerance and increased digitalis toxicity.
Seasonal variations in the nutritional status of urban Gambian children
Authors: Tomkins A. M. , Dunn D. T. , Hayes R. J. , Bradley A. K.
Published: June 2005

1. Children aged 6–35 months in an urban community in The Gambia, West Africa, were weighed and their lengths measured at four surveys over an 18-month period, twice towards the end of the rains, and twice during the dry season.

2. Relative to international standards, height-for-age deteriorated steadily with age, while weight-for-age fell sharply in the second-half of infancy but showed no further deterioration from 12 to 35 months of age.

3. Height-for-age showed little seasonal variation, but weight-for-age and weight-for-height were lower at the end of the rains than during the dry season. Weight and height velocities were much lower during the rains than in the dry season, with more than 20% of the children losing weight during the rains. Possible reasons for these seasonal variations are discussed. Compensatory weight gain in the dry season exceeded the velocity expected from the standards in children aged 12 months or more, but height velocity fell below the standards all year.

4. The results are compared with previous findings from Keneba, a rural Gambian village. Weight velocity during the dry season was similar in the two communities, but the village children experienced a sharper decline in weight gain during the rains.

5. These results suggest that seasonal ecological factors may seriously influence the nutritional status of children living in an urban environment with adequate availability of food.
Blood rheology in vegetarians
Authors: Ernst E. , Pietsch L. , Matrai A. , Eisenberg J.
Published: June 2005

1. Blood rheology has been quantified by measuring blood and plasma viscosity, packed cell volume (PCV), erythrocyte filterability and erythrocyte aggregation in forty-eight voluntary vegetarians and compared with matched controls.

2. Results show that in vegetarians, values for PCV were lower than those in controls, leading to reduced native blood viscosity. In addition PCV-standardized blood viscosity was also decreased. This was brought about mostly by lower plasma viscosity. Erythrocyte rheology seemed to be unaltered. Stricter avoidance of animal products was associated with even lower values for these indices.

3. These observations are in agreement with the fact that other low-cardiovascular-risk groups show better than average blood fluidity. They are consistent with the hypothesis that in vitro measurements of blood rheology may provide signs of early atherosclerotic changes in vivo.
Effects of a low-energy diet associated with egg supplementation on plasma cholesterol and lipoprotein levels in normal subjects: results of a cross-over study
Authors: Lacombe Christiane R. , Corraze Geneviève R. , Nibbelink Maryse M. , Boulze Danièle , Douste-Blazy Philippe , Camare Rita
Published: June 2005

1. The influence of a low-energy diet when associated with high-cholesterol intake was investigated in seventeen normal men during an 8-week cross-over study. The subjects were given a daily supplement of two whole eggs and two egg yolks (approximately 1 g cholesterol) either with their usual diet for 4 weeks or with a low-energy diet for 4 weeks. Each subject took part randomly in both dietary periods.

2. During the first part of the study, no changes occurred in the plasma cholesterol of the subjects with egg supplementation of the usual diet.

3. In contrast, the low-energy diet and associated weight loss markedly decreased the tolerance to high- cholesterol intake resulting in increased plasma cholesterol. The mean rise was 22.7% but with wide individual variations in the response. This was almost completely normalized when the subjects returned to their usual energy intake indicating the involvement of weight reduction in the increase observed.

4. Changes in low-density-lipoprotein (LDL) cholesterol were parallel to those of total plasma cholesterol with an increase following the low-energy diet and normalization after body-weight recovery.

5. The opposite effect was shown with the low-energy diet after previous adaptation to the consumption of four eggs per day. This dietary regimen resulted in a decrease in plasma cholesterol although it was not significant. Moreover, the lipoprotein profile was improved with a decrease in very-low-density-lipoprotein (VLDL) cholesterol and an increase in high-density-lipoprotein (HDL) cholesterol.

6. High-cholesterol intake induced significant changes in lipoprotein composition whatever the energy ration. LDL and HDL were enriched in cholesterol esters as early as the 1st month of egg supplementation of the diet.

7. Taken together, the results emphasize the possible adverse effect of slimming diets when associated with high-cholesterol intake. The existence of ‘high-responders’ to these dietary conditions calls for special attention to be paid to the cholesterol content of restricted diets.