bluuebunny/crossref_metadata_2025 huggingface dataset:
Chlamydial IFN-γ immune evasion is linked to host infection tropism
Authors: Nelson David E. , Virok Dezso P. , Wood Heidi , Roshick Christine , Johnson Raymond M. , Whitmire William M. , Crane Deborah D. , Steele-Mortimer Olivia , Kari Laszlo , McClarty Grant , Caldwell Harlan D.
Published: July 2005

Chlamydiae are obligate intracellular pathogens that can exhibit a broad host range in infection tropism despite maintaining near genomic identity. Here, we have investigated the molecular basis for this unique host-pathogen relationship. We show that human and murine chlamydial infection tropism is linked to unique host and pathogen genes that have coevolved in response to host immunity. This intimate host-pathogen niche revolves around a restricted repertoire of host species-specific IFN-γ-mediated effector responses and chlamydial virulence factors capable of inhibiting these effector mechanisms. In human epithelial cells, IFN-γ induces indoleamine 2,3-dioxygenase expression that inhibits chlamydial growth by depleting host tryptophan pools. Human chlamydial strains, but not the mouse strain, avoid this response by the production of tryptophan synthase that rescues them from tryptophan starvation. Conversely, in murine epithelial cells IFN-γ induces expression of p47 GTPases, but not indoleamine 2,3-dioxygenase. One of these p47 GTPases (Iigp1) was shown by small interfering RNA silencing experiments to specifically inhibit human strains, but not the mouse strain. Like human strains and their host cells, the murine strain has coevolved with its murine host by producing a large toxin possessing YopT homology, possibly to circumvent host GTPases. Collectively, our findings show chlamydial host infection tropism is determined by IFN-γ-mediated immunity.
Memory-influencing intra-basolateral amygdala drug infusions modulate expression of Arc protein in the hippocampus
Authors: McIntyre Christa K. , Miyashita Teiko , Setlow Barry , Marjon Kristopher D. , Steward Oswald , Guzowski John F. , McGaugh James L.
Published: July 2005

Activation of β-adrenoceptors in the basolateral complex of the amygdala (BLA) modulates memory storage processes and long-term potentiation in downstream targets of BLA efferents, including the hippocampus. Here, we show that this activation also increases hippocampal levels of activity-regulated cytoskeletal protein (
Arc
), an immediate-early gene (also termed Arg 3.1) implicated in hippocampal synaptic plasticity and memory consolidation processes. Infusions of the β-adrenoreceptor agonist, clenbuterol, into the BLA immediately after training on an inhibitory avoidance task enhanced memory tested 48 h later. The same dose of clenbuterol significantly increased Arc protein levels in the dorsal hippocampus. Additionally, posttraining intra-BLA infusions of a memory-impairing dose of lidocaine significantly reduced Arc protein levels in the dorsal hippocampus. Increases in Arc protein levels were not accompanied by increases in
Arc
mRNA, suggesting that amygdala modulation of
Arc
protein and synaptic plasticity in efferent brain regions occurs at a posttranscriptional level. Finally, infusions of
Arc
antisense oligodeoxynucleotides into the dorsal hippocampus impaired performance of an inhibitory avoidance task, indicating that the changes in Arc protein expression are related to the observed changes in memory performance.
Bioavailability of isoflavone phytoestrogens in postmenopausal women consuming soya milk fermented with probiotic bifidobacteria
Authors: Tsangalis Dimitri , Wilcox Gisela , Shah Nagendra P. , Stojanovska Lily
Published: July 2005

We investigated the effects of consuming an isoflavone aglycone-enriched soya milk containing viable bifidobacteria on urinary isoflavone excretion and percentage recovery. Sixteen postmenopausal women were randomly divided into two groups to consume either fermented or non-fermented soya milk. Each group participated in a double-blind, crossover study with three 14 d supplementation periods, separated by a 14 d washout. Subjects ingested three daily dosages of isoflavone via the soya milk and collected four 24 h pooled urine specimens per supplementation period. Soya milks were prepared with soya protein isolate and soya germ, followed by fermentation with bifidobacteria. Isoflavone levels were quantified using HPLC. Non-fermented soya milks at 20, 40 and 80 mg isoflavone/200 ml contained 10 %, 9 % and 7 % aglycone, respectively, with their fermented counterparts containing 69 %, 57 % and 36 % aglycone (P<0·001). A trend to a greater percentage urinary recovery of daidzein and glycitein was observed among women consuming fermented soya milk at a dosage of 40 mg isoflavone (P=0·13). A distinct linear dose response for the fermented soya milk group (R2=0·9993) compared with the non-fermented group (R2=0·8865) suggested less interindividual variation in isoflavone absorption. However, total urinary isoflavone excretion was similar for both groups (P>0·05), with urinary isoflavone recovery at approximately 31 %. Increasing the isoflavone dosage correlated positively with its urinary excretion, but urinary percentage recovery of isoflavone was inversely related to dosage level. Hence, a modest dosage ranging from 20 to 30 mg/d may provide the most bioavailable source of isoflavone, regardless of whether it is via an aglycone-rich fermented soya milk or a glucoside-rich soya milk.
Glucagon-like peptide-1 release and satiety after a nutrient challenge in normal-weight and obese subjects
Authors: Adam Tanja C. M. , Westerterp-Plantenga Margriet S.
Published: July 2005

The present study was conducted to assess whether glucagon-like peptide-1 (GLP-1) release and appetite after a breakfast with or without an additional galactose/guar gum stimulation is different in normal-weight compared with overweight/obese subjects. Twenty-eight overweight/obese (BMI 30·3 (sd 2·7) kg/m2; age 44·3 (sd 9·7) years) and thirty normal-weight subjects (BMI 22·8 (sd 1·4), age 31·5 (sd12·8) years) participated in a crossover study. Fasting and postprandial plasma GLP-1, insulin, glucose and free fatty acid concentrations were measured in response to either a galactose (50 g)/guar gum (2·5 g) load (836 kJ) and a standard breakfast (1·9 MJ; GG), or water (250 ml) and the standard breakfast (W) every 30 min relative to the ingestion for 120 min. Appetite was assessed using 100 mm visual analogue scales. GLP-1 concentrations were significantly increased after GG at 30 and 60 min compared with W in both groups. Plasma GLP-1 concentrations in the W condition were higher in normal-weight than overweight/obese subjects (P=0·03). No difference was observed in the GG condition between groups. Satiety was increased in normal-weight compared with overweight/obese subjects in the GG condition at 30 (P=0·02) and 60 (P=0·04) min. We conclude that after a standard breakfast with water, GLP-1 release was lower in the overweight/obese than the normal-weight subjects. However, postprandial GLP-1 release in overweight/obese subjects was no different from that of normal-weight subjects when galactose/guar gum was added to the breakfast. The latter was not mirrored by subjective feelings of satiety. Disturbed perception of the physiological feedback of a satiety hormone rather than disturbed feedback itself might contribute to obesity.
Is coffee a functional food?
Authors: Dórea José G. , da Costa Teresa Helena M.
Published: July 2005

Definitions of functional food vary but are essentially based on foods' ability to enhance the quality of life, or physical and mental performance, of regular consumers. The worldwide use of coffee for social engagement, leisure, enhancement of work performance and well-being is widely recognised. Depending on the quantities consumed, it can affect the intake of some minerals (K, Mg, Mn, Cr), niacin and antioxidant substances. Epidemiological and experimental studies have shown positive effects of regular coffee-drinking on various aspects of health, such as psychoactive responses (alertness, mood change), neurological (infant hyperactivity, Alzheimer's and Parkinson's diseases) and metabolic disorders (diabetes, gallstones, liver cirrhosis), and gonad and liver function. Despite this, most reviews do not mention coffee as fulfilling the criteria for a functional food. Unlike other functional foods that act on a defined population with a special effect, the wide use of coffee-drinking impacts a broad demographic (from children to the elderly), with a wide spectrum of health benefits. The present paper discusses coffee-drinking and health benefits that support the concept of coffee as a functional food.
Dietary protein:lipid ratio and lipid nature affects fatty acid absorption and metabolism in a teleost larva
Authors: Morais Sofia , Koven William , Rønnestad Ivar , Teresa Dinis Maria , Conceição Luís E. C.
Published: July 2005

Studies with teleost larvae have reported poor performance associated with quantitative lipid imbalances in the diet. The present study examined the effect of dietary protein:neutral lipid ratio on fatty acid (FA) absorption efficiency and metabolism in larval Senegalese sole. In addition, the effect of lipid class (triolein (TRI) and l-3-phosphatidylcholine-1,2-di-oleoyl (PC)), carbon number and degree of saturation of the labelled NEFA, stearic acid (SA), oleic acid (OA) and DHA) was tested. FA absorption was determined by tube feeding [1-14C]-labelled lipids and NEFA after a single meal of either non-enrichedArtemia(NEA) orArtemiaenriched on a soyabean oil emulsion (EA), or after feeding these diets over an extended period of time (18 d). The tested dietary protein:lipid ratios had no short-term influence but long-term feeding of a diet higher in neutral lipid (EA) increased lipid accumulation within the gut epithelium and resulted in lower FA absorption (higher label evacuation and lower retention of dietary FA), which may partially explain the trend for lower growth observed with this diet. The lipids and NEFA, showed different digestive and metabolic properties, independent of feeding regime. FA absorption increased with unsaturation, being lowest for SA, followed by OA, and highest for DHA. In addition, sole larvae had a lower capacity to digest and absorb FA esterified to TRI, compared with PC, with the order of decreasing absorption being NEFA>PC≫TRI. Moreover, larvae appeared to discriminate between the source of OA, as this FA in the free form or esterified to PC was catabolised less than TRI.
Deposition of dietary fatty acids and ofde novosynthesised fatty acids in growing pigs: effects of high ambient temperature and feeding restriction
Authors: Kloareg Maela , Le Bellego Laurent , Mourot Jacques , Noblet Jean , van Milgen Jaap
Published: July 2005

Predicting aspects of pork quality becomes increasingly important from both a nutritional and a technological point of view. Little information is, however, available concerning the quantitative relation between nutrient intake and fatty acid (FA) deposition at the whole-animal level. In this study, eight blocks of five littermate barrows were used in a comparative slaughter trial. At 24 kg body weight (BW), one pig from each litter was slaughtered to determine the initial FA composition. The other littermates were assigned to one of four feeding levels (ranging from 70 % to 100 % of intakead libitum) and were given a diet containing 0·36 g/kg lipid and 0·22 g/kg FA. The temperature for each block was maintained at either 23 or 30°C. At 65 kg, the pigs were slaughtered and the body lipid and FA composition was determined. Seventy per cent of the digestedn-6 FA and 50 % of then-3 FA were deposited. The average composition ofde novosynthesised FA corresponded to 1·7, 30·3, 2·4, 19·7 and 45·9 % for 14: , 16: , 16: 1, 18: and 18: 1 FA, respectively. At 23°C and for feedingad libitum, 33 % of 16: FA was deposited, 1·7 % shortened to 14: , 63 % elongated to 18: and 2·8 % unsaturated to 16: 1. Twenty-eight per cent of 18: FA was deposited and 72 % unsaturated to 18: 1. At 30°C, 18: FA desaturation was reduced by 3·5 %. Feed intake and temperature independently affected the elongation of 16: FA. A reduction in feed intake increased the elongation rate, whereas the increase in temperature reduced the elongation rate.
Dietary levels of all-transretinol affect retinoid nuclear receptor expression and skeletal development in European sea bass larvae
Authors: Villeneuve Laure , Gisbert Enric , Le Delliou Hervé , Cahu Chantal L. , Zambonino-Infante Jose L.
Published: July 2005

European sea bass larvae were fed different dietary vitamin A levels. Growth, skeletal development and the expression of genes involved in larval morphogenesis were evaluated. From 7 to 42 d post-hatching, larvae were fed five isoproteic and isolipidic compound diets with graded levels of retinyl acetate (RA; RA0, RA10, RA50, RA250 and RA1000, containing 0, 10, 50, 250 and 1000 mg RA/kg DM, respectively), resulting in an incorporation of 12, 13, 31, 62 and 196 mg all-transretinol/kg DM. Larvae fed extreme levels of RA had weights 19 % and 27 % lower than those of the RA50 group. The RA1000 diet induced a fall in growth with an increase of circulating and storage retinol forms in larvae, revealing hypervitaminosis. High levels of RA affected maturation of the pancreas and intestine. These data indicated that the optimal RA level was close to 31 mg/kg DM. Inappropriate levels of dietary RA resulted in an alteration of head organisation characterised by the abnormal development of the splanchnocranium and neurocranium, and scoliotic fish. Of the larvae fed RA1000, 78·8 % exhibited skeletal abnormalities, whereas the RA50 group presented with 25 % malformations. A linear correlation between vitamin A level and malformation percentage was observed and mainly associated with an upregulation of retinoic acid receptor-γ expression in the RA1000 group during the 2 first weeks after hatching. The expression of retinoid X receptor-α decreased during normal larval development when that of the retinoic acid receptors increased. This work highlights the involvement of retinoid pathways in the appearance of dietary-induced skeletal malformations during post-hatching development in sea bass.
Effect of n-3 fatty acids from fish on electrocardiographic characteristics in patients with frequent premature ventricular complexes
Authors: Geelen Anouk , Zock Peter L. , Brouwer Ingeborg A. , Katan Martijn B. , Kors Jan A. , Ritsema van Eck Henk J. , Schouten Evert G.
Published: July 2005

n-3 Fatty acids may protect against heart disease mortality by preventing fatal arrhythmias. Underlying effects on cardiac electrophysiology may be demonstrable in the standard electrocardiogram (ECG) and provide insight into the mechanism. Therefore, we investigated the effect of dietary n-3 fatty acids on heart-rate-corrected QT interval, T-loop width, spatial QRS-T angle and spatial U-wave amplitude in patients with frequent premature ventricular complexes. Seventy-four patients received either capsules providing 1·5 g n-3 fatty acids daily or placebo for approximately 14 weeks. ECG were recorded before and after intervention. None of the ECG characteristics was significantly affected by treatment. The present results do not provide additional support for the hypothesis that n-3 fatty acids prevent cardiac arrhythmia through generic electrophysiologic effects on heart cell membranes. However, we cannot exclude effects of n-3 fatty acids on clinical relevant endpoints that are not easily detected by prior changes in the ECG.
The influence of the glycaemic index of breakfast and lunch on substrate utilisation during the postprandial periods and subsequent exercise
Authors: Stevenson Emma , Williams Clyde , Nute Maria
Published: July 2005

The present study investigated the effects of mixed high-carbohydrate (CHO) meals (breakfast and lunch) with different glycaemic indices (GI) on substrate metabolism during rest throughout the postprandial periods and during subsequent exercise. Nine recreationally active males completed two trials, high glycaemic index (HGI) and low glycaemic index (LGI), separated by 7 d in a randomised crossover design. In each trial, participants consumed breakfast and lunch, both of which were followed by a 3 h resting postprandial period. Following this, participants completed a 60 min run at 70 % of V˙O2max. The plasma glucose and serum insulin concentrations following both meals were significantly higher in the HGI trial than in the LGI trial (P<0·05). Serum insulin concentrations remained higher throughout the postprandial period following lunch in the HGI trial compared with the LGI trial (P<0·05). The total amount of fat oxidised was higher during the 3 h rest following lunch in the LGI trial than in the HGI trial (P<0·01) and subsequently CHO oxidation was lower (P<0·005). No significant differences in substrate utilisation were observed throughout the subsequent run. At 45 and 60 min, plasma glucose concentrations were higher in the LGI trial v. the HGI trial (P<0·05). The results of the present study provide further support that the GI concept can be successfully applied to mixed meals. The results also suggest that meals composed of LGI CHO may be more beneficial for maintaining a favourable metabolic milieu during the postprandial periods. Furthermore, during subsequent exercise, plasma glucose concentrations were better maintained following the LGI CHO meals.
Evaluation of the independent and combined effects of xylitol and polydextrose consumed as a snack on hunger and energy intake over 10 d
Authors: King Neil A. , Craig Stuart A. S. , Pepper Tammy , Blundell John E.
Published: July 2005

The study assessed the independent and combined effect of two speciality carbohydrates (polydextrose and xylitol) on appetite. Eight female and seven male lean volunteers were recruited from the University of Leeds campus. Using a repeated measures design, volunteers completed four conditions in a counterbalanced order. Each condition varied according to the yoghurt formulation administered: a control yoghurt (C, yoghurt+25 g sucrose) and three experimental yoghurts (X, yoghurt+25 g xylitol; P, yoghurt+25 g polydextrose; and XP, yoghurt+12·5 g xylitol and 12·5 g polydextrose). Each condition lasted for 10 d during which volunteers consumed 200 g yoghurt on each day. On days 1 and 10, the short- and medium-term effects of yoghurt consumption were assessed by measuringad libitumlunch intake and subjective motivation to eat. The three experimental yoghurts (X, P and XP) induced a slight suppression of energy intake compared with the control (C) yoghurt, but the differences were not statistically significant. However, when the energy content of the yoghurt pre-loads were accounted for, there was a significant suppression of energy intake for P compared with C (P=0·002). The XP yoghurt induced a significantly stronger satiating effect (increase in subjective fullness) compared with C, both with (P=0·003) and without (P<0·001) the differential in energy content of the yoghurt pre-loads accounted for. The study demonstrated that pre-loads of xylitol and polydextrose caused a mild increase in satiety and suppression of energy intake, and that the effects persist after repeated daily administration. The effects exerted by the formulations containing xylitol and polydextrose did not arise from the differences in energy content of the yoghurtper se. Therefore, the usefulness of xylitol and polydextrose as ingredients in functional foods for appetite control are as a result of their lower energy content and suppression of appetite.
Urinary excretion of purine derivatives inBos indicus×Bos tauruscrossbred cattle
Authors: Ojeda Álvaro , de Parra Ornella , Balcells Joaquím , Belenguer Álvaro
Published: July 2005

Four experiments were performed to study the kinetics of purine metabolism and urinary excretion in Zebu crossbred cattle. Fasting excretion was established in Expt 1, using eighteen maleBos indicus×Bos tauruscrossbred cattle (261 (se 9·1) kg body weight), six of each of the following genotypes: 5/8Bos indicus, 1/2Bos indicusand 3/8Bos indicus. No significant differences were observed among genotypes in fasting purine derivative excretion (277·3 (se 35·43) μmol/metabolic body weight). In a second experiment we measured the xanthine oxidase activity, which was higher in liver than in duodenal mucosa (0·64 and 0·06 (se 0·12) units/g wet tissue per min respectively;P>0·05) being in plasma 0·60 (se 0·36) units/l per min. The kinetics of uric acid were measured by intravenous pulse dose of [1,3-15N]uric acid (Expt 3). The cumulative recovery of the isotope in urine was 82 (se 6·69) %, and uric acid plasma removal, pool size and mean retention time were 0·284 (se 0·051) per h, 5·45 (se 0·823) mmol and 3·52 (se 0·521) h, respectively. Allantoin was removed from plasma at an estimated fractional rate of 0·273 (se 0·081) per h and mean retention was 3·66 (se 1·08) h. In Expt 4, the relationship between urinary purine derivative excretion (Y; mmol/d) and digestible organic matter intake (X, kg/d) was defined by the equation:Y=7·69 (se 4·2)+5·69 (se 1·68)X;n16, Se 1·31,r0·67.
Traditionalv.modified dietary patterns and their influence on adolescents' nutritional profile
Authors: Song YoonJu , Joung Hyojee , Engelhardt Katrin , Yoo Sun Young , Paik Hee Young
Published: July 2005

Korea has experienced exceptionally rapid economic developments. Even though the country has managed to maintain aspects of its traditional diet, dietary habits are changing, especially among adolescents. This study was carried out to identify prevailing dietary patterns among Korean adolescents and to compare the nutrient intakes and dietary behaviours between the patterns. A 3 d diet record, collected from 671 Korean adolescents aged 12–14 years in Seoul, Korea, was assessed. By cluster analysis, subjects were classified into a modified (69·9 %) and a traditional (30·1 %) dietary pattern group. The modified group consumed more bread, noodles, cookies and pizza/hamburgers compared with the traditional group, which consumed mainly rice and kimchi (fermented cabbage). The modified group had significantly higher intakes of all nutrients. It had a higher total daily energy intake (7719 kJ), a higher daily energy intake from fat (29·8 %) and a higher cholesterol intake (326 mg/d), compared with the traditional group (6686 kJ, 24·8 % and 244 mg/d, respectively). The modified group was more likely to consume fast foods, fried foods and carbonated beverages even though they consumed more fresh fruits and milk, while the traditional group was more likely to have a rice-based diet and not to skip breakfast. These results suggest that monitoring dietary behaviours of adolescents, especially in a society experiencing a nutrition transition, is necessary in order to identify both negative and positive changes in respect of risk factors for nutrition-related chronic diseases as well as for undernutrition.
Eucalyptus leaf extract inhibits intestinal fructose absorption, and suppresses adiposity due to dietary sucrose in rats
Authors: Sugimoto Keiichiro , Suzuki Junko , Nakagawa Kazuya , Hayashi Shuichi , Enomoto Toshiki , Fujita Tomoyuki , Yamaji Ryoichi , Inui Hiroshi , Nakano Yoshihisa
Published: July 2005

Sucrose is more lipogenic than starch, and the extreme ingestion of sucrose induces adiposity and obesity. The aim of this study was to examine the effect of the eucalyptus (Eucalyptus globulus) leaf extract (ELE) on adiposity due to dietary sucrose in rats. In addition, in this study, the effect of ELE on intestinal fructose absorption was also examined. Rats were fed a high-sucrose diet (75 % in calorie base) with or without ELE (10 g/kg diet) for 5 weeks. Body weight was lower in the rats receiving ELE than in the controls (342 (sd 37·9)v. 392 (sd 26·0) g (n7);P<0·05). Furthermore, ELE resulted in decreases in the triacylglycerol concentrations in the plasma (1·44 (sd 0·448)v.2·79 (sd 0·677) mmol/l (n7);P<0·05) and liver (19·1 (sd 5·07)v.44·1 (sd 16·28) μmol/g (n7);P<0·05). In contrast, ELE did not show any significant effects in the rats fed a starch diet. When rats were orally given ELE 10 min before fructose administration, the intestinal fructose absorption, which was examined by measuring the elevated concentration of fructose in the portal vein at 30 min after the fructose administration, was significantly inhibited in a dose-dependent manner. Furthermore, in rats fed a high-fructose diet, the plasma and hepatic triacylglycerol concentrations were significantly decreased by ELE. These results indicate that ELE, which inhibits the intestinal fructose absorption, can suppress adiposity in rats that ingest large amounts of sucrose or fructose.
Purified high-dose anthocyanoside oligomer administration improves nocturnal vision and clinical symptoms in myopia subjects
Authors: Lee Jonghyun , Lee Hyung K. , Kim Chan Y. , Hong Young J. , Choe Chul M. , You Tae W. , Seong Gong J.
Published: July 2005

The aim of the present study was to determine the effect of purified high-dose anthocyanoside oligomer administration on nocturnal visual function and clinical symptoms in low-to-moderate myopia subjects. The study was a randomized, double-blind, placebo-controlled trial and involved sixty subjects with asthenopia and refractive errors between −1·00 and −8·00 diopters in both eyes. Thirty subjects were administered a purified high-dose anthocyanoside oligomer (100 mg tablet comprising 85 % anthocyanoside oligomer), and thirty were given a placebo in tablet form twice daily for 4 weeks. Prior to the treatment, the placebo and anthocyanoside groups were similar in terms of age and contrast sensitivity. Before and after treatment, subjects completed a questionnaire to determine their clinical symptoms and were also assessed for nocturnal visual function using contrast sensitivity testing. Questionnaire data analysis showed that, following treatment, twenty-two (73·3 %) anthocyanoside subjects showed improved symptoms, whereas only one placebo subject showed an improvement (Fisher's exact test,P<0·0001). Contrast sensitivity levels according to each cycle per degree significantly improved in the anthocyanoside group and remained stable in the placebo group. The mean contrast sensitivity change in the anthocyanoside group was 2·41 (SD) 1·91, compared with −0·66 (SD) 2·66 dB for the placebo group (unpaired Student'sttest,P<0·0001). At all cycle per degree levels, contrast sensitivity changes in the anthocyanoside group were better than in the placebo group (unpaired Student'sttest,P<0·05). The present data show that the administration of anthocyanoside oligomer appears to improve subjective symptoms and objective contrast sensitivity in myopia subjects with asthenopia.
Energy-modulating vitamins – a new combinatorial therapy prevents cancer cachexia in rat mammary carcinoma
Authors: Perumal Selvanathan Saravana , Shanthi Palanivelu , Sachdanandam Panchanadham
Published: July 2005

Mitochondria are the major intracellular organelles producing ATP molecules via the electron transport chain. Cancer cells have a deviant energy metabolism, and a high rate of glycolysis is related to a high degree of dedifferentiation and proliferation. The overall net ATP production is diminished with cancer, which ultimately leads to cancer cachexia. The present study was designed to investigate the altered energy metabolism in cancer cells and to enhance ATP production in the normal host cell metabolism by enhancing the activities of mitochondrial enzymes, using energy-modulating vitamins, and thus prevent cancer cachexia. Female Sprague–Dawley rats were selected for the experimental study. Mammary carcinoma was induced by the oral administration of 7,12-dimethylbenz[a]anthracene (25 mg/kg body weight), and treatment was started by the oral administration of the energy-modulating vitamins riboflavin (45 mg/kg body weight per d), niacin (100 mg/kg body weight per d) and coenzyme Q10(40 mg/kg body weight per d) for 28 d. Mitochondria were isolated from the mammary gland and liver of all four groups, and the Krebs cycle and oxidative phosphorylation enzymes were assayed. In mammary carcinoma-bearing animals, the activities of the Krebs cycle and oxidative phosphorylation enzymes were significantly decreased. These activities were restored to a greater extent in animals treated with energy-modulating vitamins. From these experimental results, one may hypothesize that the combination therapy of energy-modulating vitamins could be of major therapeutic value in breast cancer.
Effect ofTheobroma cacaoflavonoids on immune activation of a lymphoid cell line
Authors: Ramiro Emma , Franch Àngels , Castellote Cristina , Andrés-Lacueva Cristina , Izquierdo-Pulido Maria , Castell Margarida
Published: July 2005

We analysed the effect of (−)-epicatechin and cocoa extract on the activation of a lymphoid cell line. Particularly the expression of IL-2 receptor α (IL-2Rα or CD25) and, the secretion of IL-2 and IL-4 were established after flavonoid treatment. Two media culture conditions (1 and 10 % of fetal calf serum supplementation) and the different moments of flavonoid addition (simultaneously or 2 h before cell-activation) were compared. IL-2Rα (CD25) expression on activated cells was significantly reduced by epicatechin and cocoa extract in a dose-dependent manner, achieving the highest inhibition of about 50 % when flavonoids were added 2 h before stimulation. IL-2 secretion was also inhibited by the presence of both epicatechin and cocoa extract, displaying 60 and 75 % of inhibition, respectively. Cocoa flavonoids were also able to enhance 3–4·5-fold IL-4 release. In summary, cocoa extract down-modulated T lymphocyte activation and therefore the acquired immune response. This fact could be important in some states of the immune system hyperactivity such as autoimmune or chronic inflammatory diseases.
Obesity: from molecules to man
Authors: Jebb Susan A.
Published: July 2005

Obesity is now a major public health problem in both developed and developing countries. In the UK over 16 % men and 17.5 % women are obese, an increase of more than 100 % since 1980. However, interventions to prevent and treat obesity are hampered by an inadequate understanding of the aetiology of this condition. The present paper considers the current state of knowledge regarding the causes of obesity, including some of the genetic, metabolic, behavioural and environmental factors which influence energy balance. The present paper comprises The Nutrition Society Medal Lecture and focuses in particular on the research carried out at the MRC Dunn Nutrition Centre in Cambridge. It argues that despite decades of intensive research there is relatively little evidence of genetic or metabolic defects to explain the majority of cases of human obesity. Instead we must look to behavioural and/or environmental factors which may be underpinning the current epidemic of obesity.
Isotopes in nutrition research
Authors: Young Vernon R. , Ajami Alfred
Published: July 2005

The present lecture begins with a brief overview of the professional and scientific journey taken by Rudolf Schoenheimer, before turning to a discussion of the power of isotopic tracers in nutrition research. Schoenheimer's remarkable contributions to the study of intermediary metabolism and the turnover of body constituents, based initially on compounds tagged with2H and later with15N, spanned a mere decade. It is difficult, however, to overestimate the enormous impact of Schoenheimer's research on the evolution of biological science. After a relative hiatus, following Schoenheimer's death in 1941, in the use of stable nuclides as tracers in metabolism and nutrition, especially in human subjects, there is now an expanded and exciting range of techniques, experimental protocols and stable-isotope tracer compounds that are helping to probe the dynamic aspects of the metabolism of the major energy-yielding substrates, amino acids and other N-containing compounds, vitamins and mineral elements in human subjects. Various aspects of the contemporary applications of these tracers in nutrition research are covered in the present lecture.
New techniques in nutritional assessment: Body composition methods
Authors: Elia M. , Ward L. C.
Published: July 2005

New techniques in air-displacement plethysmography seem to have overcome many of the previous problems of poor reproducibility and validity. These have made body-density measurements available to a larger range of individuals, including children, elderly and sick patients who often have difficulties in being submerged underwater in hydrodensitometry systems. The BOD POD air-displacement system (BOD POD body composition system; Life Measurement Instruments, Concord, CA, USA) is more precise than hydrodensitometry, is simple and rapid to operate (approximately 1 min measurements) and the results agree closely with those of hydrodensitometry (e.g. ± 3.4 % for estimation of body fat). Body line scanners employing the principles of three-dimensional photography are potentially able to measure the surface area and volume of the body and its segments even more rapidly (approximately 10s), but the validity of the measurements needs to be established. Advances in i.r. spectroscopy and mathematical modelling for calculating the area under the curve have improved precision for measuring enrichment of 2H2O in studies of water dilution (CV 0.1–0.9 % within the range of 400–1000 μl/1) in saliva, plasma and urine. The technique is rapid and compares closely with mass spectrometry (bias 1 (SD 2) %). Advances in bedside bioelectrical-impedance techniques are making possible potential measurements of skinfold thicknesses and limb muscle mass electronically. Preliminary results suggest that the electronic method is more reproducible (intra- and inter-individual reproducibility for measuring skinfold thicknesses) and associated with less bias (+ 12 %), than anthropometry (+40%). In addition to these selected examples, the ‘mobility’ or transfer of reference methods between centres has made the distinction between reference and bedside or field techniques less distinct than in the past.
Problems of nutritional assessment in the acute setting
Authors: Baxter J. P.
Published: July 2005

Surveys have shown that 20–50 % of hospital admissions suffer from nutritional depletion and that there is failure to recognize its existence and significance. More emphasis must be placed in clinical medicine on identifying subjects who are at high risk of developing disease-related malnutrition. There is a need to screen patients on admission to hospital to identify those at risk of nutrition-related complications. More formal determination of nutritional status should be carried out to define the nutritional status of the patient and to monitor changes in nutritional status during nutritional support. The most frequently used tests of nutritional status include dietary, anthropometric, biochemical and functional indices of nutritional status. It is important, and indeed is the skill of the nutritional care team (particularly the dietitian) to be able to evaluate these measurements, as many of them are affected by non-nutritional factors. There is no consensus on the best method for the accurate assessment of nutritional status. Practical difficulties arise with individual measurements and in their interpretation in the acute setting. The aim of the present paper is to identify the most relevant variables to measure in clinical medicine, and to discuss the limitations of their use in the acute setting.
Eating habits and appetite control: a psychobiological perspective
Authors: Rogers Peter J.
Published: July 2005

An individual's eating behaviour is shaped by factors ranging from economic conditions and cultural practices to biological influences. The physiological system controlling appetite appears to be adapted to solving the problem of an unevenness of food supply across time, and is fairly permissive in its response to undereating and overeating. Consequently, when food is abundant, the diet is energy dense and energy expenditure is low, there is a strong tendency to become obese (i.e. obesity is better viewed as due to a ‘toxic’ environment than to faulty physiological control of appetite). Under such conditions the most common method of avoiding obesity is through the cognitive control of eating. However, dietary restraint and dieting are demanding tasks, and are associated with psychological costs, including significant impairment of cognitive performance. Restraint is also prone to disinhibition, with the result that it can sometimes undermine eating control, even leading to the development of highly disordered eating patterns. In part, these difficulties are due to the self-perpetuating nature of dietary habits: for example, hunger tends to be diminished during strict unbroken dieting, but increased in individuals having a highly variable eating pattern (such as occurs when eating is frequently disinhibited). These features of appetite control provide both barriers and opportunities for changing behaviour. Accordingly, there is a need for future research to focus on the psycho-social factors and the dieting practices predicting successful eating and weight control, with the objective of identifying the actual cognitive and behavioural strategies used by the many dieters and restrained eaters who are able to achieve weight loss and maintain long-term weight stability.
The influence of the maternal uterine immune response on placentation in human subjects
Authors: King Ashley , Loke Y. W.
Published: July 2005

The immunological relationship beween the mammalian fetus and its mother during pregnancy has been considered similar to that between a transplanted allograft and its recipient ever since Medawar (1953) first proposed the concept of the ‘fetus as an allograft’ in the early 1950s. Based on this analogy, it has been assumed that implantation of the fetal placenta in the uterus would be controlled similarly by a maternal immune response mediated by T-cells recognizing paternally-derived alloantigens expressed by the placenta. Surprisingly, recent evidence suggests that implantation might involve predominantly a novel allogeneic recognition system based on natural killer cells rather than T-cells (Loke & King, 1995). The cellular and molecular basis of this local immune interaction between the fetal placenta and maternal uterus is now the focus of intense research interest. Since aberrant implantation can cause a variety of clinical problems, including miscarriage, intrauterine growth retardation and pre-eclampsia, an understanding of the immunological mechanism by which this process is controlled could lead to the development of regimens to improve fetal growth and development.
Prematurity, immune function and infant feeding practices
Authors: Hampton Shelagh M.
Published: July 2005

Recently, there has been much interest in the literature in the role of early nutrition and the health of the individual in adulthood. A majority of infants in the UK are born full term, while preterm infants account for 4–6 % of the total births. Milk feeding practices are divided into three groups: breast, combination (breast-fed with formula as‘top-up) and bottle (formula). In studies conducted by our group and other researchers immune function in full-term and preterm infants has been assessed by monitoring total and specific immunoglobulin E and specific immunoglobulin G levels. Dietary modification by the pregnant mother with a history of allergy in the family has been shown to have a positive effect with respect to allergy outcome and prevention of atopic disease in the infant. However, this dietary modification has to occur before week 22 of pregnancy and continue until the end of lactation to achieve a beneficial outcome to the infant. The stress of mothers restricting their diets may be disadvantageous to the fetus, and therefore any gain due to the dietary restriction may be lost. Researchers have shown that the early introduction of complementary foods and the greater diversity of these foods appeared to result in an increase in the incidence of atopic disease in the infant. In conclusion, in order to reduce the risk in their babies, mothers with a family history of atopic disease should breast-feed for more than 15 weeks and introduce solid foods after 4 months, limiting the variety until at least 6 months.
Effects of dietary antioxidants on the immune function of middle-aged adults
Authors: Hughes David A.
Published: July 2005

The immune system is highly reliant on accurate cell–cell communication for optimal function, and any damage to the signalling systems involved will result in an impaired immune responsiveness. Oxidant-mediated tissue injury is a particular hazard to the immune system, since phagocytic cells produce reactive oxygen species as part of the body's defence against infection. Adequate amounts of neutralizing antioxidants are required, therefore, to prevent damage to the immune cells themselves. Many antioxidants can be obtained directly from the diet (e.g. ascorbic acid, α-tocopherol, carotenoids and polyphenolic flavonoids) or require micronutrients as integral components (e.g. Se in the metalloenzyme glutathione peroxidase (EC 1.11.1.9)). Numerous epidemiological studies have found strong associations between diets rich in antioxidant nutrients and a reduced incidence of cancer, and it has been suggested that a boost to the body's immune system by antioxidants might, at least in part, account for this. Although more striking effects have been observed in the elderly, there is also evidence that antioxidant nutrients can modify cell-mediated immune responses in younger individuals. Indeed, it might be essential to have an adequate intake of antioxidant nutrients from an early age in order to help prevent the development of, or at least delay the onset of, several degenerative disorders. The present paper will review the effects of specific nutrients on immune function in young to middle-aged human subjects, focusing on the antioxidant vitamins C and E, and on Se. A further review, dealing more specifically with the effects of carotenoids on human immune function, will be presented at a forthcoming meeting of the Nutrition Society.
Preparing for inactivity: How insectivorous bats deposit a fat store for hibernation
Authors: Speakman John R. , Rowland Angela
Published: July 2005

During late autumn insectivorous bats must deposit a fat store to cover their energy demands throughout the period of hibernation, yet the density of aerial insects by this time has already declined from its peak in midsummer. Krzanowski (1961) suggested that bats are able to deposit a fat store by manipulating their energy expenditure; specifically by selecting cold roosting locations rather than warm roosts, and depressing their body temperatures during the day roosting period. It was hypothesized that these behavioural changes result in very low daily energy demands, and despite reduced food intake the animals are still able to gain body fat. We made several tests of this hypodiesis. First, we explored the thermo-selection behaviour of long-eared bats (Plecotus auritus) in the summer and in the pre-hibernal period. We found that in summer bats preferred temperatures of about 32–35° (about thermoneutral), but in the pre-hibernal period they preferred much colder temperatures of about 10°. Second, using open-flow respirometry we found that in the cold pre-hibernal bats entered torpor for an average of 14 h each day. Compared with bats held at 30° (that did not go torpid), the bats at 7° expended less energy. The extent of saving was sufficient to positively affect their mass balance, despite the fact that bats at lower temperature also had reduced digestive efficiencies. Our findings support the hypothesis that during the pre-hibernal period insectivorous bats manipulate their mass balance primarily by alterations in their energy expenditure, specifically utilizing energy-sparing mechanisms such as torpor.
The regulation of mineral absorption in the gastrointestinal tract
Authors: Powell J. J. , Jugdaohsingh R. , Thompson R. P. H.
Published: July 2005

The absorption of metal ions in the mammalian single-stomached gut is fortunately highly selective, and both luminal and tissue regulation occur. Initially, assimilation of metal ions in an available form is facilitated by the intestinal secretions, chiefly soluble mucus (mucin) that retards hydrolysis of ions such as Cu, Fe and Zn. Metal ions then bind and traverse the mucosally-adherent mucus layer with an efficiency M+> M2+> M3+. At the mucosa Fe3+is probably uniquely reduced to Fe2+, and all divalent cations (including Fe2+) are transported by a membrane protein (such as divalent cation transporter 1) into the cell. This minimizes absorption of toxic trivalent metals (e.g. A13+). Intracellular metal-binding molecules (such as mobilferrin) may be present at the intracellular side of the apical membrane, anchored to a transmembrane protein such as an integrin complex. This mobilferrin would receive the metal ion from divalent cation transporter 1 and, with part of the integrin molecule, transport the metal to the cytosol for safe sequestration in a larger complex such as ferritin or‘paraferritin’. β2-Microglobulin and HFE (previously termed human leucocyte antigen H) may be involved in stabilizing metal mobilferrin-integrin to form this latter complex. Finally, a systemic metal-binding protein such as transferrin may enter the antiluminal (basolateral) side of the cell for binding of the sequestered metal ion and delivery to the circulation. Regulatory proteins, such as HFE, may determine the degree of ion transport from intestinal cells to the circulation. Gradients in pH and perhaps pCa or even pNa could allow the switching of ions between the different transporters throughout this mechanism.
Bioavailability of carotenoids in human subjects
Authors: Parker Robert S. , Swanson Joy E. , You Cha-Sook , Edwards Alison J. , Huang Tina
Published: July 2005

There is growing need for accurate information regarding the bioavailability of carotenoids, both with respect to carotenoidsper seand to the vitamin A value of provitamin A carotenoids in foods or supplement preparations. Little quantitative information is currently available, owing primarily to the lack of adequate methods to assess carotenoid bioavailability. Methods applied to xenobiotic drugs are in most cases not useful for carotenoids, many of which circulate in appreciable quantities in human plasma. Reported ranges of carotenoid bioavailability (% dose absorbed) range from 1–99, and variability is generally high both within and between treatments. With the current methods, relative bioavailability is more readily assessed than absolute bioavailability. The most commonly applied methods include measuring the increase in plasma carotenoid concentration following chronic intervention, and use of postprandial chylomicron (PPC) carotenoid or retinyl ester response following a single dose of carotenoid. The advantages and limitations of these approaches, together with examples of each, are discussed. A new PPC approach utilizing extrinsic-stable-isotope-labelled vitamin A (2H4-labelled retinyl acetate) is under development in our laboratory, and examples of its application are presented. The currently available data suggest that oil solutions of carotenoids are more bioavailable than those from food matrices, and heating can improve the bioavailability of carotenoids from some food products. Increased availability of labelled carotenoids and retinoids should aid the development of reliable methods of carotenoid bioavailability assessment. Such data are needed for dietary recommendations, supplement formulation, and design of intervention strategies involving carotenoids.