bluuebunny/crossref_metadata_2025 huggingface dataset:
Genistein-induced apoptosis in MCF-7 cells involves changes in Bak and Bcl-x without evidence of anti-oestrogenic effects
Authors: Po Lai See , Wang Thomas T. , Chen Zhen-Yu , Leung Lai K.
Published: April 2003

South-east Asian women have a lower rate of breast cancer compared with their counterparts in western countries and the difference in soyabean consumption has been claimed to be a major contributing factor. Genistein is the most studied phytochemical in the soyabean. An anti-oestrogenic effect is believed to play a crucial part in its chemopreventive mechanism. In the present study, we expressed oestrogen receptor (OR) in an OR-negative cell line, HepG2, to investigate the pro- and anti-oestrogenic effect of genistein on the OR transcriptional activity. Genistein by itself had an estimated concentration that induced 50 % of the maximum response (EC50) of 2·5 μM FOR THE BINDING TO OR-α. IN THESE EXPERIMENTS, GENISTEIN CONCENTRATION AS HIGH AS 50 μM could not reduce the oestrogen response element-driven luciferase activities initiated by oestradiol. Instead, genistein potentiated the OR transactivational activity while cell death was detected. On the other hand, an increased Bak and a reduced Bcl-x(L) was observed at 50 μm-genistein by Western analysis. The combined effect of these two proteins could be important in the apoptotic process. Since plasma genistein >50 μm has never been documented following consuming of soyabean or soyabean products, the present study does not support the notion that dietary soyabean exerts its chemopreventive effect through antagonizing OR.
Increasing the viscosity of the intestinal contents stimulates proliferation of enterotoxigenicEscherichia coliandBrachyspira pilosicoliin weaner pigs
Authors: Hopwood D. E. , Pethick D. W. , Hampson D. J.
Published: April 2003

The present study was designed to evaluate the effect of increased viscosity of the intestinal digesta on proliferation of enterotoxigenicEscherichia coliand the intestinal spirochaeteBrachyspira pilosicoliin weaned pigs. Pigs were fed an experimental diet based on cooked white rice (R), which was supplemented with carboxymethylcellulose (CMC; 40 g/kg diet) to increase digesta viscosity. Thirty-six piglets weaned at 21 d of age were divided into six groups, three of which were fed R and three R+CMC. Addition of CMC increased digesta viscosity in the ileum (P=0·01), caecum (P=0·0007) and colon (P=0·0035), without increasing indices of large intestinal fermentation. Pigs fed R+CMC developed a natural infection with enterotoxigenicE. coliafter weaning and had more (P<0·0001) diarrhoea than pigs fed R. Subsequent experimental infection of two groups of pigs withB. pilosicoliresulted in more (P<0·0001) colonisation in pigs fed R+CMC than R. At this time, all pigs fed R+CMC had wetter (P<0·0001) faeces than those fed R, irrespective of whether they were infected withB. pilosicoli, but infected pigs also had an increased (P=0·025) number of days with diarrhoea post-infection irrespective of diet. In pigs fed R+CMC, it was not clear to what extent the increased viscosity associated with CMC, or the concurrent infection with enterotoxigenicE. coli, was responsible for the increased proliferation ofB. pilosicoli. In a second experiment, five pigs that were weaned onto an R diet were transferred onto R+CMC 3 weeks later. These pigs did not develop a natural infection with enterotoxigenicE. coliafter the diet change, confirming the particular susceptibility of pigs to enterotoxigenicE. coliproliferation immediately post-weaning.
Serum concentrations of homocysteine are elevated during early pregnancy in rodent models of fetal programming
Authors: Petrie Linda , Duthie Susan J. , Rees William D. , McConnell Josie M. L.
Published: April 2003

Maternal malnutrition can lead to fetal abnormalities and increase susceptibility to disease in later life. Rat models have been developed to study the physiology and metabolism underlying this phenomenon. One particular model of 50% protein restriction during pregnancy, the low-protein diet (LPD) supplemented with methionine, has been developed to investigate the underlying mechanisms. Recent studies have shown that rats fed a LPD during only the first 4 d of pregnancy produce offspring that develop hypertension. These results suggest that the very earliest stages of embryo development are susceptible to diet-induced heritable changes. We demonstrate a marked elevation of maternal serum homocysteine (hcy) concentrations during the initial phases of pregnancy in both rats and mice fed an LPD. Fetal growth and many of the circulating amino acids are similarly perturbed in both rats and mice fed the LPD during pregnancy, indicating that the response to the LPD diet is similar in rats and mice. These findings allow us to exploit the advantages of the mouse experimental system in future analyses aimed at understanding the molecular basis of fetal programming. Our present findings are discussed with particular reference to mechanisms which may initiate fetal programming, and to the feasibility of dietary interventions aimed at reducing early pregnancy loss and pre-eclampsia in man.
Morphological and immune response alterations in the intestinal mucosa of the mouse after short periods on a low-magnesium diet
Authors: Zimowska W. , Girardeau J. P. , Kuryszko J. , Bayle D. , Rayssiguier Y. , Mazur A.
Published: April 2003

The importance of Mg for the immune function is well recognized; however, there is no information available about the effect of Mg intake on the modulation of local immune response in the intestine. Thus, in the present study the hypothesis that short periods of Mg deprivation can affect intestinal mucosa and local immune response was tested. For this purpose, OF1 female mice were fed a semipurified diet (1000 mg Mg/kg diet). For 3 d before immunization and 1 d after, half of the animals were fed a Mg-deficient diet (30 mg Mg/kg diet), three immunizationsper oswere performed every 3 weeks withEscherichia coliproducing the CS31A capsule-like protein (1010or 2×109 bacteria per animal). Mice were killed 10 d after the last immunization. The level of specific anti CS31A immunoglobulin (Ig) G and IgA in the serum and secretory IgA in the intestinal secretions and faeces were measured by ELISA. The results indicated that administration of a high dose of immunogen with a low-Mg diet led to lower specific IgA levels in the intestinal mucus and serum. Administration of a low dose of immunogen with a low-Mg diet led to lower IgA and IgG levels in the serum and secretory IgA coproantibodies. To assess alterations of intestinal mucosa caused by a low-Mg diet for a short period, histological and scanning electron microscopy analyses were performed on samples from mice (not submitted to the vaccination protocol) after 3 d on the Mg-deficient diet. These analyses showed several alterations, suggesting perturbations in the growth of the intestinal mucosa. These changes were accompanied by modifications in the expression of several genes involved in cell growth and stress response. From this present work, it may be concluded that short periods of Mg deprivation can affect the intestinal mucosa and local immune response of the intestine.
Age-related association of small intestinal mucosal enteropathy with nutritional status in rural Gambian children
Authors: Campbell David I. , Lunn Peter. G. , Elia Marinos
Published: April 2003

Small bowel enteropathy (assessed by the lactulose (L): mannitol (M) permeability test) is a major factor in infant growth faltering and malnutrition in The Gambia. However, little is known about its persistence and nutritional effect beyond 2 years of age. This was addressed by two cross-sectional studies of intestinal permeability and nutritional status in 162 residents, aged 2–60 years, living in three villages in rural Gambia. L:M ratio was found to be highest in the youngest children and although there was a significant improvement with age (P<0·0001), values were always greater than the range found in UK counterparts. M recovery (mean value 5·68 (SE 0·12)%) was at all times between one-third and one-half of expected UK values and showed no improvement with age. Gut barrier function, assessed by L uptake, improved with age (P<0·001) and fell within the UK normal range beyond age 10 years. Both the L:M permeability ratio and L recovery were significantly associated with height-for-age z-scores (r−0·31 and −0·22 respectively, P<0·001), a relationship that persisted throughout childhood and into adulthood. Change in height-for-age z-score beween the two visits was also related to the L:M ratio (r−0·24, P=0·018). The close within-subject correlation of permeability variabilities between the two visits suggests a long-term persistence of enteropathy within individuals. It appears that the small bowel enteropathy previously described in Gambian infants persists through to adulthood. Although the lesion improves with age, the relationship between attained height and L:M permeability raises the possibility that enteropathy may continue to limit growth throughout childhood and puberty.
Determinants of fat mass in prepubertal children
Authors: Müller M. J. , Grund A. , Krause H. , Siewers M. , Bosy-Westphal A. , Rieckert H.
Published: April 2003

The aim of the present study was to compare variables of metabolism, physical activity and fitness to body composition in normal and overweight children in a cross-sectional study design. Body composition was assessed by anthropometric measurements and bioelectrical impedance analysis in forty-eight prepubertal children (age 5–11 years, thirteen normal-weight, thirty-five overweight). Total energy expenditure (EE) was measured by combination of indirect calorimetry (for measurement of resting EE) and individually calibrated 24 h heart-rate (HR) monitoring. Activity-related EE and physical activity level (PAL) were calculated. Time spent with min-by-min HR>FLEX HR was also used as a marker of moderate habitual and vigorous activities. Aerobic fitness (O2pulse (O2consumption:HR at submaximal steady-state heart rate), submaximal O2consumption (VO2submaximal), RER at a HR of 170 beats per min) was determined by bicycle ergometry. Muscle strength of the legs (maximal isometric strength ofmusculus quadricepsand ofmusculus ischiocruralis(Fa max and Fb max respectively)) was measured by computer tensiometry. When compared with normal children, overweight children had higher skinfold thicknesses (sum of skinfold thicknesses at four sites +160%), fat mass (+142%), waist (+24%) and hip circumferences (+14%), resting EE (+13%) and RER (+5%). No significant group differences were found for fat-free mass, muscle mass, total EE, activity-related EE, PAL, HR>FLEX HR, VO2submaximal, O2pulse, Fa max and Fb max as well as the fat-free mass- or muscle mass-adjusted values for resting EE, aerobic fitness and muscle strength. When compared with normal children, overweight children had a lower measuredv.estimated resting EE (Δ resting EE) and spent more time watching television. There were positive relationships between fat-free mass(x)and resting EE(x), total EE(y), aerobic fitness(y)and muscle strength(y), but only Δ resting EE(x)and HR>FLEX HR(x)correlated with fat mass(y). In a stepwise multivariate regression analysis resting EE adjusted for fat-free mass and Δ resting EE were significant determinants of % fat mass and explained 29·7% of its variance. Thus, in the present cross-sectional study, resting EE was the most important determinant of fat mass.
Large bowel fermentation of maize or sorghum–acorn diets fed as a different source of carbohydrates to Landrace and Iberian pigs
Authors: Morales J. , Pérez J. F. , Martín-Orúe S. M. , Fondevila M. , Gasa J.
Published: April 2003

Twenty-four finishing pigs (twelve Iberian and twelve Landrace) were used in a growing and slaughtering experiment. Animals were fed two diets differing in their ingredients, maize (diet C) or sorghum–acorn (diet A). At an average weight of 107·0 kg pigs were slaughtered and hindgut digesta sampled to study the effect of breed and diet on large bowel fermentation. Flows of digesta to the hindgut compartment were estimated based on an indigestible flow marker (Cr2O3) and were higher in Iberian than in Landrace pigs (P<0·001), and higher in animals fed diet A than diet C (P=0·07). The higher flows in Iberian pigs were mainly associated with a higher voluntary feed intake (3·50v.2·70 kg/d,P<0·01) and lower ileal digestibility of NSP (−12·8v.47·8,P<0·01). Differences between diets were mainly associated with a lower ileal digestibility of starch from diet A (89·2v.96·9%,P=0·06), although no differences in the resistant starch content were observedin vitro. Fermentation of different carbohydrates through the large bowel showed that NSP-glucose had lower digestibility in Iberian than in Landrace pigs (62·5v.94·2%,P<0·001), but no differences were observed in starch, or other NSP-fibre fractions (arabinose, xylose and galactose). The type and amount of carbohydrates reaching the large bowel were related to the diet but also to breed, and promoted differences in the fermentative activity associated with different volatile fatty acid patterns and changes in microbial enzymic activity.
Plasma amino acid concentrations in healthy and cognitively impaired oldest-old individuals: associations with anthropometric parameters of body composition and functional disability
Authors: Ravaglia Giovanni , Forti Paola , Maioli Fabiola , Bianchi Giampaolo , Sacchetti Loredana , Talerico Teresa , Nativio Valeria , Mariani Erminia , Macini Pierluigi
Published: April 2003

Only a few reports exist of plasma amino acid profiles in the oldest-old, and none exist of the oldest-old with cognitive problems. Therefore, we measured fasting plasma amino acid concentrations in twenty-three healthy community-dwellers aged 90–103 years (group A); eighteen community-dwellers with mild cognitive impairment without dementia aged 91–104 years (group B); thirty-three patients with dementia aged 96–100 years (group C); and sixty healthy young controls aged 20–50 years. Biochemical and anthropometric parameters, and the basic activities of daily living (ADL) were also measured. Independent of cognitive status, in all oldest-old groups, essential:non essential amino acids (EAA:NEAA) was lower than in young controls and positively associated with body muscle mass. Patients with dementia were further characterized by a negative association between EAA:NEAA and the number of dependent ADL. All oldest-old groups had higher values of tyrosine:other large neutral amino acids (LNAA) than young controls. Groups B and C also had a higher phenylalanine:other LNAA. These data show that abnormalities in plasma amino acid profile are common in oldest-old individuals independent of their cognitive status, but that, in oldest-old patients with dementia, they are associated with functional disability. The abnormalities in phenylalanine and tyrosine plasma availability could contribute to the cause or aggravation of concurrent cognitive problems because these amino acids are neurotransmitter precursors and compete with other LNAA for transport into the brain.
Nutritional status of drug addicts undergoing detoxification: prevalence of malnutrition and influence of illicit drugs and lifestyle
Authors: Nazrul Islam S. K. , Hossain Kazi Jahangir , Ahmed Afsaruddin , Ahsan Monira
Published: April 2003

The aim of the present study was to investigate the nutritional status of drug addicts, the prevalence of malnutrition among them and the influence of their drug habit and lifestyle factors on their nutritional indices. The study was conducted among 253 male drug addicts, who sought detoxification at the Central Drug Addiction Treatment Hospital, Dhaka, during the period of June 1998–July 1999. One hundred age-, height- and socioeconomic-matched non-addicted healthy men were recruited by convenience as cohort controls. Results showed that the drug addicts had significantly (P<0·001) lowered BMI, haemoglobin, and serum total protein and albumin levels. Clinical signs of nutrient deficiency were diagnosed in about 74 % of drug addicts. The BMI, biochemical values and nutrient deficiency signs indicated that more than 60 % of drug addicts were suffering from multiple malnutrition. One-way ANOVA demonstrated a significant (P<0·05) negative correlation between drug habit, sexually transmitted diseases and selected nutritional indices, and a positive correlation between education, income and the nutritional indices. A series of multiple regression analyses revealed that education, income and age showed significantly predicted BMI and biochemical indices, and the group (non-drug addicts or drug addicts) had a significant negative effect on these parameters in favour of controls.
Predictors of micronutrient status in men and women over 75 years old living in the community
Authors: McNeill Geraldine , Vyvyan Juliet , Peace Heather , McKie Linda , Seymour Gwyn , Hendry Judith , MacPherson Isobel
Published: April 2003

Serum ferritin, serum vitamin B12, erythrocyte folate, plasma vitamin C and plasma 25-hydroxycholecalciferol levels were measured in 208 men and 197 women, >75 years old and living in the community, in order to assess micronutrient status. Anthropometric measurements (height, weight, demispan and mid-upper arm circumference) were made and a 114-item questionnaire covering a wide range of health and diet-related topics was administered by an interviewer. Only 4% of subjects had a BMI <20, but the prevalence of marginal deficiency of the micronutrients ranged from 7% for Fe to 47% for vitamin D. There was no association between low micronutrient status (defined as being in the lowest third of the distribution of micronutrient status) and having BMI or mid-upper arm circumference in the lowest third of the distribution for any of the nutrients. Leaving food on the plate was strongly associated with both low Fe status and low vitamin D status. Having breakfast cereal less than once per week was strongly associated with low folate status, while having fresh fruit juice less than once per week, having had less than two portions of fruits and vegetables the previous day and believing that food is not important for health were strongly associated with low vitamin C status. Low vitamin D status was strongly associated with a wide range of general health and disability measures. Having a weekly household income of less than £150 was associated with low status of Fe, folate, vitamin C and vitamin D.
Assessing sleeping energy expenditure in children using heart-rate monitoring calibrated against open-circuit indirect calorimetry: a pilot study
Authors: Beghin L. , Michaud L. , Guimber D. , Vaksmann G. , Turck D. , Gottrand F.
Published: April 2003

Total energy expenditure (EE) can be assessed in children by the heart-rate (HR) monitoring technique calibrated against open-circuit indirect calorimetry (IC). In this technique, sleeping EE is usually estimated as the lowest value of a 30 min resting EE measurement×0·90 to give an average for the total sleeping period. However, sleeping is a dynamic process in which sleeping EE is modulated by the effect of factors such as body movement and different sleep stages. The aim of the present study was to determine a new method to improve the sleeping EE measurement by taking into account body movements during sleep. Twenty-four non-obese children participated in the present study. All subjects passed through a calibration period. HR and EE measured by IC were simultaneously collected during resting, the postprandial period, and during different levels of activity. Different methods for computing sleeping EE (resting EE×0·90 with different breakpoints (‘flex point’ HR with linear regression or ‘inflection point’ (IP) HR with the third order polynomial regression equation (P3)) were compared with EE measured for least 2·0 h in eight sleeping children. The best method of calculation was then tested in sixteen children undergoing HR monitoring and with a body movement detector. In a subset of eight children undergoing simultaneous sleeping EE measurement by IC and HR, the use of the equation resting EE×0·8 when HRIP during the sleeping period gave the lowest difference (1 (SD 5·4) %) compared with other methods (linear or polynomial regressions). The new formula was tested in an independent subset of sixteen other children. The difference between sleeping ee computed with the formula resting EE×0·90 and sleeping EE computed with resting EE×0·8 when HRIP during sleeping periods was significant (13 (sd 5·9)%) only for active sleeping subjects (n 6 of 16 subjects). The correlation between the difference in the results from the two methods of calculation and body movements was close (r 0·63, P<0·005, Spearman test) as well as computed sleeping EE (Spearman test, r 0·679, P<0·001), indicating that this new method is reliable for computing sleeping EE with HR monitoring if children are moving during sleep and improves the total EE assessment.
Comparison of vitamin C deficiency with food restriction on collagen cross-link ratios in bone, urine and skin of weanling guinea-pigs
Authors: Tsuchiya Harumi , Bates C. J.
Published: April 2003

Mild-to-moderate vitamin C depletion in weanling guinea-pigs affects pyridinoline:deoxypyridinoline (collagen cross-link) ratios in femur shaft and urine, attributed to impairment of hydroxylation of collagen lysine. We investigated: (1) whether the picture at two time points is compatible with progressive accumulation of abnormal collagen; (2) whether any changes are seen in skin, where little deoxypyridinoline occurs; (3) whether total food restriction has similar effects. Male weanling Dunkin–Hartley guinea-pigs were fed diets containing either 0·5 (vitamin C-restricted) or 160·0–320·0 (vitamin C-adequate) mg vitamin /. Two groups receiving the vitamin C-adequate diet received itad libitum. Two other groups received the vitamin C-adequate diet in a restricted amount, limited to that which permitted nearly the same growth rate as in the vitamin C-restricted groups. Animals were fed for 4 or 8 weeks; urine was collected, and vitamin C and collagen indices were measured. In the femur shaft, the hydroxyproline content per unit weight was unaffected by vitamin C restriction or by total food restriction. Deoxypyridinoline was increased and the pyridinoline:deoxypyridinoline ratio was decreased in vitamin C-restricted groups, but not in food-restricted groups. Changes in the value of the ratio were greater after 8 than after 4 weeks. Urine indices mirrored bone indices. In skin, the main effect of vitamin C restriction was to reduce hydroxyproline. Here, the cross-link ratios changed less markedly than in bone, and there was less deoxypyridinoline. We conclude that the picture at two time points is compatible with a progressive accumulation of pyridinoline-enriched collagen in vitamin C-deprived animals, that the picture in skin differs from that of bone and urine, and that cross-link changes are not produced by total food restriction.
Plasma homocysteine concentration is decreased by dietary intervention
Authors: Silaste Marja-Leena , Rantala Maire , Alfthan Georg , Aro Antti , Kesäniemi Y. Antero
Published: April 2003

High plasma total homocysteine (tHcy) concentration is reported to be a risk factor for vascular diseases. We investigated the extent to which serum folate and plasma tHcy respond to a high intake of natural folate from food. Thirty-seven healthy females volunteered to participate in a crossover dietary intervention. The study included a baseline period and two 5-week diet periods (low- and high-folate diets) with a 3-week washout in between. The low-folate diet contained one serving of both vegetables and frui/, while during the high-folate diet the subjects ate at least seven servings of vegetables, berries, and citrus frui/. Serum and erythrocyte (RBC) folate, serum vitamin B12, and plasma tHcy concentrations were measured at the baseline and at the end of each diet period. The mean concentrations of serum and RBC folate were 11·0 (sd 3·0) nmo/ and 412 (sd 120) nmo/ at the end of the low-folate diet and 78 (95 % CI 62, 94) % and 14 (95 % CI 8, 20) % higher in response to the high-folate diet (P<0·001). The serum concentration of vitamin B12remained unchanged during the intervention. The mean plasma tHcy concentration was 8·0 μmo/ at the end of the low-folate diet and decreased by 13 (95 % CI 9, 18) % in response to the high-folate diet (P<0·001). In conclusion, a diet high in fresh berries, citrus fruit, and vegetables effectively increases serum and RBC folate and decreases plasma homocysteine.
Local (gut) and systemic metabolism of rats is altered by consumption of raw bean (Phaseolus vulgarisL. var.athropurpurea)
Authors: de Moya Carmen Cavallé , Grant George , Frühbeck Gema , Urdaneta Elena , García María , Marzo Florencio , Santidrián Santiago
Published: April 2003

The composition of the raw legumePhaseolus vulgarisL. var.athropurpurea(PhVa) and its effects on the metabolism of young growing rats have been evaluated. The levels of protein, unsaturated fatty acids, carbohydrate, fibre and bioactive factors present in PhVa were comparable with those in otherPhaseolus vulgarisvarieties. However, the lectins of PhVa were predominantly of the leucoagglutinating type, and concentrated in the albumin protein fraction. Rats fed a diet (110 g total protein, 16·0 M/g) in which PhVa meal provided about half of the protein excreted high levels of N in faeces and urine, and grew more slowly, than rats fed a high-quality control diet (ad libitumor pair-fed). Small intestine, large intestine and pancreas weights were increased (by almost 100 %,P<0·05), whilst skeletal muscle, thymus and spleen weights were reduced. Blood insulin 16·20v.0·50 m/,P<0·05, thyroxine, glucose, protein (60·5v.48·3 /,P<0·05) and LDL-cholesterol were lowered, whilst glucagon (155·3v.185·4 n/,P<0·05), triiodothyronine and urea were elevated, as were urinary urea, creatinine and glucose. These changes in the local (gut) and systemic metabolism of rats were probably mediated primarily by lectins in PhVa, which were concentrated in the albumin protein fraction, whereas in many otherPhaseolus vulgarislines they are distributed across the globulin and albumin fractions.
An approach to construct simplified measures of dietary patterns from exploratory factor analysis
Authors: Schulze Matthias B. , Hoffmann Kurt , Kroke Anja , Boeing Heiner
Published: April 2003

Exploratory factor analysis might work well in elucidating the major dietary patterns prevailing in specific study populations. However, patterns extracted in one study population and their associations with disease risk cannot be reproduced with this data-specific method in other study populations. To construct less population-dependent pattern variables of similar content as original exploratory patterns, we proposed to derive so-called simplified pattern variables. They represent the sum of the unweighted standardised food variables which loaded high at the pattern of interest. Data from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study suggest that these simplified pattern variables might adequately approximate factor analysis-based dietary patterns. A simplified pattern variable based on the six highest loading food variables showed a correlation >0·95 with the originally derived factor score, which consisted of forty-seven food variables. Moreover, simplified pattern variables might adequately approximate patterns across different study populations. A simplified pattern variable showed similar factor loadings, ranging from 0·34 to 0·52, as well as similar associations with nutrient intake as a ‘western’ pattern originally reported from an US study population. These simplified pattern variables can subsequently be used to study pattern associations with disease risk, especially in multi-centre studies. It is therefore an approach that might overcome one of the most frequently claimed limitations of factor analyses applied in epidemiology: their non-comparable risk estimates.
Folic acid treatment reduces elevated plasma levels of asymmetric dimethylarginine in hyperhomocysteinaemic subjects
Authors: Holven Kirsten B. , Haugstad Tor S. , Holm Torbjørn , Aukrust Pål , Ose Leiv , Nenseter Marit S.
Published: April 2003

Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO synthase, has been suggested to be a novel risk factor for endothelial dysfunction. It has previously been reported that hyperhomocysteinaemia may be associated with impaired endothelium-dependent vasodilation and reduced plasma level of NO-derived endproducts (NOx). In the present study, plasma levels of arginine and ADMA were measured in twenty-one healthy control subjects, and in twenty-one hyperhomocysteinaemic subjects before and after 6 weeks and 12 months of folic acid supplementation, and compared with previously measured plasma NOx values in the hyperhomocysteinaemic subjects. Compared with control subjects, hyperhomocysteinaemic subjects had higher plasma levels of arginine and ADMA. More importantly, folic acid therapy significantly reduced plasma levels of arginine and ADMA. Furthermore, plasma levels of arginine and ADMA were positively correlated with plasma homocysteine levels and negatively correlated with plasma folate, as well as negatively correlated with plasma NOx. Our results suggest that ADMA may be a mediator of the atherogenic effects of homocysteine.
The problem of predicting food intake during the period of adaptation to a new food: a model
Authors: Whittemore Emma C. , Emmans Gerry C. , Kyriazakis Ilias
Published: April 2003

A model is described which aims to predict intake immediately following a change from one food to another that is higher in bulk content; it deals with the transition from one ‘equilibrium’ intake to another. The system considered is an immature pig fedad libitumon a single homogeneous food, which is balanced for nutrients and contains no toxins so that the first limiting resource is always energy. It is assumed that an animal has a desired rate of food intake (DFI) which is that needed to meet the energy requirements for protein and lipid deposition and for maintenance. DFI may not be achieved if a bulk constraint to intake exists. Where a bulk constraint operates intake is calculated as constrained food intake (CFI) where CFI=Cwhc/WHC k/ (where WHC is the water-holding capacity of the food (kg wate/g dry food) and Cwhcis the animal's capacity for WHC (unit/g live weight per d)). Where intake is not constrained it is assumed that genetic potential will be achieved. Potential growth rate is described by the Gompertz growth function. Where intake is constrained, growth will be less than the potential. Constrained growth rate is predicted as (d/t)con=(EI−Em)/egk/ where W is pig weight (kg), EI is energy intake (M/), Emis the energy required for maintenance (M/) and egis the energy required for unit gain (M/g). The value of egdepends on weight and the fattening characteristics of the pig. Actual growth is predicted to be the lesser of potential and constrained growth. To deal with adaptation it is assumed that the time taken to reach equilibrium depends on the difference in WHC values between the previous and current food and that the capacity to consume food bulk is related to the WHC of the current food. It is proposed that the capacity for WHC on the first day on a new food will be equal to the current capacity for WHC on the last day of the previous food. Thus Cwhc=(FI×WHC)/W /g, where FI is food intake (k/). Thereafter Cwhcwill gradually increase over time to a maximum of 0·27 /g. The rate of change in Cwhcis made to be the same for all pigs and all foods. The increase in capacity over time is assumed to be linear at the rate of 0·01 unit/. The model was tested using published data. Qualitatively the predictions of the model were in close agreement with the relevant observed data in at least some cases. It is concluded that the underlying theoretical assumptions of the model are reasonable. However, the model fails to predict initial intake when changed to foods high in wheat-bran content and fails to predict the intake of a non-limiting food where compensatory increases in intake and gain occur. The model could be adapted to overcome the first failure by taking into account the time course of digestive efficiency following a change in food. To deal with the second would require a sufficient understanding of the time course of compensatory growth.
The source of fatty acids incorporated into proliferating lymphoid cells in immune-stimulated lymph nodes
Authors: Pond Caroline M. , Mattacks Christine A.
Published: April 2003

To explore the hypothesis that proliferating lymphoid cells in immune-stimulated lymph nodes obtain nutrients locally from adjacent adipose tissue, adult guinea pigs were fed for 6 weeks on standard chow or on chow supplemented with 100 g suet, sunflower oil or fish oi/g. All the guinea pigs ate standard chow for the last 5 d, during which swelling of one popliteal lymph node was stimulated by repeated local injection of lipopolysaccharide. The fatty acid compositions of phospholipids in both popliteal and in several mesenteric lymph nodes, and of triacylglycerols in eleven samples of adipose tissue defined by their anatomical relations to lymph nodes, were determined by GC. The proportions of fatty acids in the phospholipids extracted from the stimulated popliteal node correlated best with those of triacylglycerols in the surrounding adipocytes, less strongly with those of adipocytes elsewhere in depots associated with lymphoid tissue, but not with those of nodeless depots. The composition of triacylglycerols in the perinodal adipose tissue changed under local immune stimulation. We conclude that proliferating lymphoid cells in activated lymph nodes obtain fatty acids mainly from the triacylglycerols in adjacent perinodal adipose tissue. Immune stimulation prompts changes in the fatty acid composition of the triacylglycerols of adipocytes in node-containing depots that equip the adipose tissue for provisioning immune responses. Such local interactions show that specialised adipocytes can act as an interface between whole-body and cellular nutrition, and may explain why mammalian adipose tissue is partitioned into a few large and many small depots.
Hydrolysis of phytic acid and its availability in rabbits
Authors: Marounek M. , Dušková D. , Skřivanová V.
Published: April 2003

Twenty weaned rabbits were fed ad libitum two granulated feeds containing lucerne meal, barley, oats, wheat bran, oilseed meals and sugarbeet pulp in different proportions. Phytate P in these feeds represented 28·6 and 29·3 % of the total P. Digestibility trials were carried out in rabbits 7 and 10 weeks old. Digestibility of phytate P was 82·1 %, on average. Apparent digestibility of total P was 48·1 and 35·5 % in rabbits aged 7 and 10 weeks, respectively. Concentration of P in the faecal DM of these rabbits averaged 11·9 and 14·7 m/. Most of the faecal P was phosphates P (68·1 %). Proportion of phytate P in total faecal P was 9·0 %. Age effect on total P digestibility and faecal P concentration was significant (P<0·05). In five in vitro experiments twenty-four rabbits were killed at the age of 11 weeks, digesta samples diluted with physiological saline containing phytic acid and incubated anaerobically. Calculations of phytase activity in segments of the digestive tract were based on the estimation of phytic acid hydrolysed during the first 2 h of incubation. The caecum contained 58·6 % of the phytase activity of the digestive tract. Corresponding relative values for the phytase activity in the stomach, small intestine and colon were 22·3, 7·7 and 11·4 %, respectively. In incubations of the caecal contents, phytic acid was hydrolysed more rapidly at pH 5–6 than in the neutral pH region. The hydrolysis was inhibited by Ca cations, and to a small extent also by phosphate anions. Commercial fungal phytase (Natuphos®) was highly active in incubations of the contents of the stomach at pH 1·9. It can be concluded that phytic acid is hydrolysed quite efficiently in the digestive tract of rabbits. This hydrolysis occurred mainly in the caecum. Absorption of soluble inorganic phosphates in the gut is incomplete.
Glycaemic index of cereal products explained by their content of rapidly and slowly available glucose
Authors: Englyst Klaus N. , Vinoy Sophie , Englyst Hans N. , Lang Vincent
Published: April 2003

Elucidating the role of carbohydrate quality in human nutrition requires a greater understanding of how the physico-chemical characteristics of foods relate to their physiological properties. It was hypothesised that rapidly available glucose (RAG) and slowly available glucose (SAG), in vitro measures describing the rate of glucose release from foods, are the main determinants of glycaemic index (GI) and insulinaemic index (II) for cereal products. Twenty-three products (five breakfast cereals, six bakery products and crackers, and twelve biscuits) had their GI and II values determined, and were characterised by their fat, protein, starch and sugar contents, with the carbohydrate fraction further divided into total fructose, RAG, SAG and resistant starch. Relationships between these characteristics and GI and II values were investigated by regression analysis. The cereal products had a range of GI (28–93) and II (61–115) values, which were positively correlated (r2 0·22, P<0·001). The biscuit group, which had the highest SAG content (8·6 (sd 3·7) g per portion) due to the presence of ungelatinised starch, was found to have the lowest GI value (51 (sd 14)). There was no significant association between GI and either starch or sugar, while RAG was positively (r2 0·54, P<0·001) and SAG was negatively (r2 0·63, P<0·001) correlated with GI. Fat was correlated with GI (r2 0·52, P<0·001), and combined SAG and fat accounted for 73·1 % of the variance in GI, with SAG as the dominant variable. RAG and protein together contributed equally in accounting for 45·0 % of the variance in II. In conclusion, the GI and II values of the cereal products investigated can be explained by the RAG and SAG contents. A high SAG content identifies low-GI foods that are rich in slowly released carbohydrates for which health benefits have been proposed.
Consumption of bakery products, sweetened soft drinks and yogurt among children aged 6–7 years: association with nutrient intake and overall diet quality
Authors: Rodríguez-Artalejo Fernando , López García Esther , Gorgojo Lydia , Garcés Carmen , Royo Miguel Ángel , Martín Moreno José María , Benavente Mercedes , Macías Alfonso , de Oya Manuel
Published: April 2003

The present study tests the hypothesis that higher consumption of bakery products, sweetened soft drinks and yogurt is associated with higher intake of energy, saturated fats, sugars and worse overall diet quality among Spanish children. This is a cross-sectional study covering 1112 children aged 6.0–7.0 years in four Spanish cities. Nutrient and food intake were obtained through a food-frequency questionnaire, and overall diet quality calculated using the healthy-eating index (HEI) developed by Kennedyet al.(1995). Standardized methods were used to measure anthropometric variables. Associations of interest were summarized as the difference in nutrient and food consumption between the value of the fifth and the first quintile of consumption (dq) of bakery products, sweetened soft drinks or yogurt, adjusted for energy intake and BMI. Bakery products, sweetened soft drinks and yogurt supplied 15·5, 1·0 and 5·6 % energy intake respectively. Higher consumption of these three foods was associated with greater energy intake (P<0·001), but not with higher BMI. Consumption of bakery products was associated with the proportion of energy derived from intake of total carbohydrates (dq 4·5 %,P<0·001) and sugars (dq 2 %,P<0·001), but did not show association with the HEI. Consumption of sweetened soft drinks was associated with a lower consumption of milk (dq −88 ml,P<0·001) and Ca (dq −175 m/,P<0·001), and worse HEI (dq −2,P<0·01). Consumption of yogurt, while associated with higher energy intake from saturated fats (dq 1·77 %,P<0·001) and sugars (dq 2·02 %,P<0·001), showed no association with the HEI. Differences in the intake of nutrients and foods across quintiles of consumption of bakery products, sweetened soft drinks and yogurt were usually very small. We conclude that the impact of the consumption of bakery products, sweetened soft drinks and yogurt on the quality of the diet of Spanish children is only modest, although it may contribute to aggravating certain unhealthy characteristics of their diet, particularly excess energy, saturated fats and sugars. Therefore, consumption of bakery products and sweetened soft drinks should be moderated, and priority given to consumption of low-fat, low-sugar yogurt.
Carbohydrate-induced manipulation of insulin sensitivity independently of intramyocellular lipids
Authors: Goff Louise M. , Frost Gary S. , Hamilton Gavin , Thomas E. Louise , Dhillo Waljit S. , Dornhorst Anne , Bell Jimmy D.
Published: April 2003

Subjects with insulin resistance have been shown to have higher storage levels of intramyocellular lipid (IMCL) than their insulin-sensitive counterparts. It has been proposed that elevated IMCL stores may be the main cause of insulin resistance. The aim of the present study was to ascertain whether there is a causal relationship between IMCL storage and insulin resistance. IMCL storage was assessed using magnetic resonance spectroscopy and insulin sensitivity was assessed by performing an oral glucose tolerance test. A 4-week intervention of reduction of dietary glycaemic index was used to manipulate insulin sensitivity in a cohort of healthy volunteers; the effects of this intervention on IMCL were measured after 4 weeks of intervention. Significant improvements in the insulin sensitivity index occurred following the dietary intervention (baseline 7·8 (sem 1·11) v. post-intervention 9·7 (sem 1·11), P=0·02). However, there were no changes in IMCL storage levels, suggesting that insulin sensitivity can be manipulated independently of IMCL. This suggests that in healthy volunteers, insulin sensitivity is independent of IMCL storage and the high storage levels that have been found in insulin-resistant subjects may occur as a consequence rather than a cause of insulin resistance.
Role of dietary fat type in the development of adiposity from dietary obesity-susceptible Sprague–Dawley rats
Authors: Jang In Surk , Hwang Dae Yeon , Chae Kab Ryong , Lee Ju Eun , Kim Yong Kyu , Kang Tae Seok , Hwang Jin Hee , Lim Chae Hyung , Huh Young Bum
Published: April 2003

The present study was designed to define how dietary fat type regulates body adiposity in dietary obesity-susceptible (DOS) Sprague–Dawley (SD) rats. Eighty-three SD rats received a purified diet containing 50 g maize oil (MO)/kg for 3 weeks and then thirty-nine of the rats, designated as the DOS rats, were allotted to diets containing 160 g MO (DOS-MO), beef tallow (DOS-BT) or fish oil (DOS-FO)/kg for 9 weeks. As a result of the experiment, the DOS-FO rats had significantly (P<0·05) reduced weight gain and abdominal and epididymal fat-pad mass than the DOS-MO and DOS-BT rats. Serum leptin level was also significantly (P<0·05) lower in the DOS-FO rats; however, hypothalamic leptin receptor (a and b) mRNA and neuropeptide Y expressions were not altered by dietary fat sources. A lower acetyl-CoA carboxylase mRNA expression in the liver was observed in the DOS-FO group, whereas hepatic peroxisome proliferator-activated receptor-γ mRNA and protein expressions were markedly elevated in the DOS-FO group compared with those in the other groups. We did not observe differences in acetyl-CoA carboxylase and peroxisome proliferator-activated receptor-γ expressions in epididymal fat of the DOS rats consuming MO, BT or FO. It is concluded from our present observations that dietary fat type, especially that rich in FO, plays a potential role in down-regulation of adiposity by altering hepatic lipogenic genes, rather than feeding behaviour, in the DOS-SD rats.
Dietary cholesterol reduces lipoprotein lipase activity in the atherosclerosis-susceptible Bio F1B hamster
Authors: McAteer Martina A. , Grimsditch David C. , Vidgeon-Hart Martin , Benson G. Martin , Salter Andrew M.
Published: April 2003

We have compared lipoprotein metabolism in, and susceptibility to atherosclerosis of, two strains of male Golden Syrian hamster, the Bio F1B hybrid and the dominant spot normal inbred (DSNI) strain. When fed a normal low-fat diet containing approximately 40 g fat and 0·3 g cholestero/g, triacylglycerol-rich lipoprotein (chylomicron+VLDL) and HDL-cholesterol were significantly higher (P<0·001) in Bio F1B hamsters than DSNI hamsters. When this diet was supplemented with 150 g coconut oil and either 0·5 or 5·0 g cholestero/g, significant differences were seen in response. In particular, the high-cholesterol diet produced significantly greater increases in plasma cholesterol and triacylglycerol in the Bio F1B compared with the DSNI animals (P=0·002 andP<0·001 for cholesterol and triacylglycerol, respectively). This was particularly dramatic in non-fasting animals, suggesting an accumulation of chylomicrons. In a second experiment, animals were fed 150 g coconut oi/g and 5·0 g cholestero/g for 6 and 12 months. Again, the Bio F1B animals showed dramatic increases in plasma cholesterol and triacylglycerol, and this was confirmed as primarily due to a rise in chylomicron concentration. Post-heparin lipoprotein lipase activity was significantly reduced (P<0·001) in the Bio F1B compared with the DSNI animals at 6 months, and virtually absent at 12 months. Bio F1B animals were also shown to develop significantly more (P<0·001) atherosclerosis. These results indicate that, in the Bio F1B hybrid hamster, cholesterol feeding reduces lipoprotein lipase activity, thereby causing the accumulation of chylomicrons that may be associated with their increased susceptibility to atherosclerosis.
Detection of caseinophosphopeptides in the distal ileostomy fluid of human subjects
Authors: Meisel H. , Meisel H. , Fairweather-Tait S. , FitzGerald R. J. , Hartmann R. , Lane C. N. , McDonagh D. , Teucher B. , Wal J. M.
Published: April 2003

Caseinophosphopeptides (CPP) were detected for the first time in ileostomy fluid, collected at 2 h intervals for 10 h post milk and CPP ingestion, from human volunteers with an ileostomy. The level of CPP present in ileostomy fluid obtained from milk-fed volunteers was markedly higher than that from volunteers fed with selected CPP preparations. The findings are based on HPLC analysis in combination with peptide-bound P determination, thin-layer electrophoresis and amino acid analysis, together with ELISA studies using polyclonal antibodies raised against a set of CPP to detect immunoreactive CPP in ileostomy fluid. These procedures allowed the detection of nm concentrations of CPP. CPP, which can be released during intestinal digestion, may function as bioactive constituents and carriers for different minerals, especially Ca, and may be used as ingredients in functional foods or pharmaceutical preparations.