bluuebunny/crossref_metadata_2025 huggingface dataset:
Silencing Geranylgeranyl Diphosphate Synthase inNicotiana attenuataDramatically Impairs Resistance to Tobacco Hornworm
Authors: Jassbi Amir Reza , Gase Klaus , Hettenhausen Christian , Schmidt Axel , Baldwin Ian T.
Published: October 2007

In bioassays with artificial diets, the 17-hydroxygeranyllinalool diterpenoid glycosides (HGL-DTGs) of Nicotiana attenuata function as antifeedants for the plant's adapted herbivore, tobacco hornworm (Manduca sexta). To determine whether HGL-DTGs have a defensive function in planta, we suppressed HGL-DTG production by silencing the source of the geranylgeranyl diphosphates (GGPPs) required for geranyllinalool biosynthesis, a key intermediate. We used virus-induced gene silencing to suppress transcript levels of GGPP synthase gene (Naggpps) and farnesyl diphosphate (FPP) synthase gene (Nafpps), northern blotting and real-time polymerase chain reaction to quantify transcript accumulations, and radio gas chromatography to analyze prenyltransferase specificity. Silencing Nafpps had no effect on the accumulation of HGL-DTGs but decreased leaf steroid content, demonstrating that DTG-synthesizing enzymes do not use GGPP derived from FPP and confirming FPP's role as a steroid precursor. Unlike plants silenced in the phytoene desaturase gene (Napds), which rapidly bleached, Naggpps-silenced plants had reduced HGL-DTG but not carotenoids or chlorophyll contents, demonstrating that Naggpps supplies substrates for GGPP biosynthesis for HGL-DTGs, but not for phytoene or phytol. Expression of Naggpps in Escherichia coli revealed that the recombinant protein catalyzes the GGPP synthesis from isopentenyl diphosphate and dimethylallyl diphosphate. When fed on silenced plants, hornworm larvae gained up to 3 times more mass than those that fed on empty vector control plants or plants silenced in Nafpps, the trypsin protease inhibitor gene, or the putrescine N-methyltransferase gene. We conclude that HGL-DTGs or other minor undetected diterpenoids derived from GGPP function as direct defenses for N. attenuata and are more potent than nicotine or trypsin protease inhibitors against attack by hornworm larvae.
SALT TOLERANCE HOMOLOG2, a B-Box Protein in Arabidopsis That Activates Transcription and Positively Regulates Light-Mediated Development
Authors: Datta Sourav , Hettiarachchi Chamari , Johansson Henrik , Holm Magnus
Published: October 2007

CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1) and ELONGATED HYPOCOTYL5 (HY5) are two major regulators of light signaling in plants. Here, we identify SALT TOLERANCE HOMOLOG2 (STH2) as a gene that interacts genetically with both of these key regulators. STH2 encodes a B-box–containing protein that interacts physically with HY5 in yeast and in plant cells. Whereas STH2 is uniformly nuclear by itself, it shows a COP1-dependent localization to speckles when coexpressed with COP1. We identified two independent T-DNA insertion lines in STH2. Both alleles are hyposensitive to blue, red, and far-red light. The sth2 mutant, like hy5, shows an enhanced number of lateral roots and accumulates less anthocyanin. Analysis of double mutants between sth2 and hy5 indicates that STH2 has both HY5-dependent and -independent functions. Furthermore, besides partially suppressing the hypocotyl phenotype of dark-grown cop1 alleles, sth2 also suppresses the reduced number of lateral roots and high anthocyanin levels in light-grown cop1 alleles. Interestingly, we found that STH2 can activate transcription. Transient transfection assays in protoplasts using a LUC reporter driven by the chalcone isomerase promoter show that the B-boxes in STH2 and a functional G-box element in the promoter are required for this activity. In conclusion, we have identified STH2, a B-box protein in Arabidopsis thaliana, as a positive regulator of photomorphogenesis and report that the B-box domain plays a direct role in activating transcription in plants.
The Pentatricopeptide Repeat GeneOTP43Is Required fortrans-Splicing of the Mitochondrialnad1Intron 1 inArabidopsis thaliana
Authors: de Longevialle Andéol Falcon , Meyer Etienne H. , Andrés Charles , Taylor Nicolas L. , Lurin Claire , Millar A. Harvey , Small Ian D.
Published: October 2007

The mitochondrial NADH:ubiquinone oxidoreductase complex (Complex I) is a large protein complex formed from both nuclearly and mitochondrially encoded subunits. Subunit ND1 is encoded by a mitochondrial gene comprising five exons, and the mature transcript requires four RNA splicing events, two of which involve trans-splicing independently transcribed RNAs. We have identified a nuclear gene (OTP43) absolutely required for trans-splicing of intron 1 (and only intron 1) of Arabidopsis thaliana  nad1 transcripts. This gene encodes a previously uncharacterized pentatricopeptide repeat protein. Mutant Arabidopsis plants with a disrupted OTP43 gene do not present detectable mitochondrial Complex I activity and show severe defects in seed development, germination, and to a lesser extent in plant growth. The alternative respiratory pathway involving alternative oxidase is significantly induced in the mutant.
Thiamine diphosphate binds to intermediates in the assembly of adenovirus fiber knob trimers in Escherichia coli
Authors: Schulz Ryan , Zhang Yian‐Biao , Liu Chang‐Jun , Freimuth Paul
Published: October 2007

Assembly of the adenovirus (Ad) homotrimeric fiber protein is nucleated by its C‐terminal knob domain, which itself can trimerize when expressed as a recombinant protein fragment. The non‐interlocked, globular structure of subunits in the knob trimer implies that trimers assemble from prefolded monomers through a dimer intermediate, but these intermediates have not been observed and the mechanism of assembly therefore remains uncharacterized. Here we report that expression of the Ad serotype 2 (Ad2) knob was toxic for thi− strains of Escherichia coli, which are defective in de novo synthesis of thiamine (vitamin B1). Ad2 knob trimers isolated from a thi+ strain copurified through multiple chromatography steps with a small molecule of mass equivalent to that of thiamine diphosphate (ThDP). Mutant analysis did not implicate any specific site for ThDP binding. Our results suggest that ThDP may associate with assembly intermediates and become trapped in assembled trimers, possibly within one of several large cavities that are partially solvent‐accessible or buried completely within the trimer interior.
Monte Carlo refinement of rigid‐body protein docking structures with backbone displacement and side‐chain optimization
Authors: Lorenzen Stephan , Zhang Yang
Published: October 2007

Structures of hitherto unknown protein complexes can be predicted by docking the solved protein monomers. Here, we present a method to refine initial docking estimates of protein complex structures by a Monte Carlo approach including rigid‐body moves and side‐chain optimization. The energy function used is comprised of van der Waals, Coulomb, and atomic contact energy terms. During the simulation, we gradually shift from a novel smoothed van der Waals potential, which prevents trapping in local energy minima, to the standard Lennard‐Jones potential. Following the simulation, the conformations are clustered to obtain the final predictions. Using only the first 100 decoys generated by a fast Fourier transform (FFT)‐based rigid‐body docking method, our refinement procedure is able to generate near‐native structures (interface RMSD <2.5 Å) as first model in 14 of 59 cases in a benchmark set. In most cases, clear binding funnels around the native structure can be observed. The results show the potential of Monte Carlo refinement methods and emphasize their applicability for protein–protein docking.
Protein kinase C delta is phosphorylated on five novel Ser/Thr sites following inducible overexpression in human colorectal cancer cells
Authors: Welman Arkadiusz , Griffiths John R. , Whetton Anthony D. , Dive Caroline
Published: October 2007

Phosphorylation plays an important role in regulation of protein kinase C delta (PKCδ). To date, three Ser/Thr residues (Thr 505, Ser 643, and Ser 662) and nine tyrosine residues (Tyr 52, Tyr 64, Tyr 155, Tyr 187, Tyr 311, Tyr 332, Tyr 512, Tyr 523, and Tyr 565) have been defined as regulatory phosphorylation sites for this protein (rat PKCδ numbering). We combined doxycycline‐regulated inducible gene expression technology with a hypothesis‐driven mass spectrometry approach to study PKCδ phosphorylation pattern in colorectal cancer cells. We report identification of five novel Ser/Thr phosphorylation sites: Thr 50, Thr 141, Ser 304, Thr 451, and Ser 506 (human PKCδ numbering) following overexpression of PKCδ in HCT116 human colon carcinoma cells grown in standard tissue culture conditions. Identification of potential novel phosphorylation sites will affect further functional studies of this protein, and may introduce additional complexity to PKCδ signaling.
A rapid and universal tandem‐purification strategy for recombinant proteins
Authors: McCluskey Andrew J. , Poon Gregory M.K. , Gariépy Jean
Published: October 2007

A major goal in the production of therapeutic proteins, subunit vaccines, as well as recombinant proteins needed for structure determination and structural proteomics is their recovery in a pure and functional state using the simplest purification procedures. Here, we report the design and use of a novel tandem (His)6‐calmodulin (HiCaM) fusion tag that combines two distinct purification strategies, namely, immobilized metal affinity (IMAC) and hydrophobic interaction chromatography (HIC), in a simple two‐step procedure. Two model constructs were generated by fusing the HiCaM purification tag to the N terminus of either the enhanced green fluorescent protein (eGFP) or the human tumor suppressor protein p53. These fusion constructs were abundantly expressed in Escherichia coli and rapidly purified from cleared lysates by tandem IMAC/HIC to near homogeneity under native conditions. Cleavage at a thrombin recognition site between the HiCaM‐tag and the constructs readily produced untagged, functional versions of eGFP and human p53 that were >97% pure. The HiCaM purification strategy is rapid, makes use of widely available, high‐capacity, and inexpensive matrices, and therefore represents an excellent approach for large‐scale purification of recombinant proteins as well as small‐scale protein array designs.
Expression screening of integral membrane proteins fromHelicobacter pylori26695
Authors: Psakis Georgios , Nitschkowski Sandra , Holz Caterina , Kreß Daniel , Maestre‐Reyna Manuel , Polaczek Julia , Illing Gerd , Essen Lars‐Oliver
Published: October 2007

The efficiency ofHelicobacter pylorias a mucosal pathogen is caused by unique soluble and integral membrane proteins, which allow its survival at acidic pH and successful colonization of the gastric environment. With about one‐fourth of theH. pylori's proteome comprising integral membrane proteins, the need for solution of their three‐dimensional (3D) structures becomes persistent as it can potentially drive the generation of more effective drugs. This study presents a medium‐throughput approach for cloning and expression screening of integral membrane proteins fromH. pylori(26695) usingEscherichia colias the expression host. One‐hundred sixteenH. pyloritargets were cloned into two different vector systems and heterologously expressed inE. coli. Eighty‐four percent of these proteins displayed medium to high expression. No clear‐cut correlation was found between expression levels and number of putative transmembrane spans, predicted functionality, and molecular mass. Nonetheless, expression of transporters and hypothetical proteins ≤40 kDa with two to four transmembrane spans displayed generally high expression levels. To statistically strengthen the quality of the data from the medium‐throughput approach, a comparison with data derived from robotic‐based methodologies was conducted. Optimization of expression and solubilization conditions for selected targets was also performed. Seventeen targets have been purified and subjected to crystallization so far. Eighteen percent of these targets (2/17) produced crystals under specific sets of crystallization conditions.
Phosphoinositide binding regulates α‐actinin CH2 domain structure: Analysis by hydrogen/deuterium exchange mass spectrometry
Authors: Full Stephen J. , Deinzer Max L. , Ho P. Shing , Greenwood Jeffrey A.
Published: October 2007

α‐Actinin is an actin bundling protein that regulates cell adhesion by directly linking actin filaments to integrin adhesion receptors. Phosphatidylinositol (4,5)‐diphosphate (PtdIns (4,5)‐P2) and phosphatidylinositol (3,4,5)‐triphosphate (PtdIns (3,4,5)‐P3) bind to the calponin homology 2 domain of α‐actinin, regulating its interactions with actin filaments and integrin receptors. In this study, we examine the mechanism by which phosphoinositide binding regulates α‐actinin function using mass spectrometry to monitor hydrogen–deuterium (H/D) exchange within the calponin homology 2 domain. The overall level of H/D exchange for the entire protein showed that PtdIns (3,4,5)‐P3 binding alters the structure of the calponin homology 2 domain increasing deuterium incorporation, whereas PtdIns (4,5)‐P2 induces changes in the structure decreasing deuterium incorporation. Analysis of peptic fragments from the calponin homology 2 domain showed decreased local H/D exchange within the loop region preceding helix F with both phosphoinositides. However, the binding of PtdIns (3,4,5)‐P3 also induced increased exchange within helix E. This suggests that the phosphate groups on the fourth and fifth position of the inositol head group of the phosphoinositides constrict the calponin homology 2 domain, thereby altering the orientation of actin binding sequence 3 and decreasing the affinity of α‐actinin for filamentous actin. In contrast, the phosphate group on the third position of the inositol head group of PtdIns (3,4,5)‐P3 perturbs the calponin homology 2 domain, altering the interaction between the N and C terminus of the full‐length α‐actinin antiparallel homodimer, thereby disrupting bundling activity and interaction with integrin receptors.
Host–pathogen protein interactions predicted by comparative modeling
Authors: Davis Fred P. , Barkan David T. , Eswar Narayanan , McKerrow James H. , Sali Andrej
Published: October 2007

Pathogens have evolved numerous strategies to infect their hosts, while hosts have evolved immune responses and other defenses to these foreign challenges. The vast majority of host–pathogen interactions involve protein–protein recognition, yet our current understanding of these interactions is limited. Here, we present and apply a computational whole‐genome protocol that generates testable predictions of host–pathogen protein interactions. The protocol first scans the host and pathogen genomes for proteins with similarity to known protein complexes, then assesses these putative interactions, using structure if available, and, finally, filters the remaining interactions using biological context, such as the stage‐specific expression of pathogen proteins and tissue expression of host proteins. The technique was applied to 10 pathogens, including species of Mycobacterium, apicomplexa, and kinetoplastida, responsible for “neglected” human diseases. The method was assessed by (1) comparison to a set of known host–pathogen interactions, (2) comparison to gene expression and essentiality data describing host and pathogen genes involved in infection, and (3) analysis of the functional properties of the human proteins predicted to interact with pathogen proteins, demonstrating an enrichment for functionally relevant host–pathogen interactions. We present several specific predictions that warrant experimental follow‐up, including interactions from previously characterized mechanisms, such as cytoadhesion and protease inhibition, as well as suspected interactions in hypothesized networks, such as apoptotic pathways. Our computational method provides a means to mine whole‐genome data and is complementary to experimental efforts in elucidating networks of host–pathogen protein interactions.
Nutrition in catering
Authors: Lawson J. M. , Hunt C. , Glew G.
Published: October 2007

For the purposes of this paper, catering activities are classified into three parts: If or profit, 2 at breakeven, 3 subsidised. The second group are mainly canteens and the health service and the third group includes the armed forces and some educational authorities. However, the industry has a poor statistical base and quantitive data are only available for broad characteristics. In 1978 the industry in the UK employed 2.14 million and the industry is labour intensive. Also in 1978 the National Health Service provided 600 million meals and some 3.5 million school meals were prepared a day during school term. Overall, it is estimated that, in 1976, eating out accounted for 12 per cent of expenditure on foods.

The newer systems of catering, cook freeze and cook‐chill, are described and the significance of the separation of production from service which these systems make possible are assessed with particular reference to nutrient value at the time of consumption. The most labile nutrients are vitamins C, thiamin and folic acid.

The advantages of Fast Foods in encouraging the consumption of nutritious foods are discussed and particular attention is drawn to the potential risk of over consumption of salt, energy and fat and under consumption of folic acid and iron if total diets consist exclusively of specific fast foods.

The potential use of institutional catering in an educational role is discussed with particular reference to a trial organised with the Mersey Docks and Harbour Company as part of the Port of Liverpool Heart Health Campaign, where an attempt will be made to decrease the intake of fat and salt and to increase the intake of fibre.
Intense sweeteners in the UK
Authors: HENNESSY TESSA J.
Published: October 2007

The article reviews the background to the FA CC report on sweeteners in food, and the recommendations made by the committee, regarding a permitted list of intense and bulk sweeteners.

With the introduction of several new sweeteners onto the UK market imminent, the article describes the properties, applications and nutritional/dietetic implications resulting from the use of the intense sweeteners that have been approved for food use in the UK.
Enzymes in food processing
Authors: COWAN W. D.
Published: October 2007

The purpose of the article is to review the use of food grade industrial enzymes in food processing. Only those enzymes directly added or deliberately used by the food manufacturer are considered. Areas of application covered include the baking industry, the dairy industry, the starch processing industry, the protein processing industry, and the fruit juice industry. The brewing and distilling industries are not included here as part of the food processing area.

In addition, enzymes applied to cleaning of food processing plant and in food analysis are mentioned.

Finally, the future developments of these products are briefly reviewed.
Flavour perception
Authors: THOMSON D. M. H.
Published: October 2007

Flavour is a product of perception and is, thus, a sensory rather than a physical or chemical phenomenon. It is largely the combination of taste (salt, sweet, bitter, acid), perceived when the gustatory receptor cells located on the tongue are stimulated, and odour, perceived when any of 17,000different volatile chemicals enter the nasal cavity and interact with the olfactory receptor cells. However, pain, heat, cold, tactile and other sensations also contribute to flavour.

One manifestation of appetite is change in the perceived pleasantness of flavour during food consumption, and this may influence the amount eaten. Appetite is flavour‐specific to some extent, which encourages variety in food intake and hence the acquisition of a range of nutrients. Flavour pleasantness may also be important in the regulation of weight control. For these reasons, flavour must be taken into account when considering nutritional aspects of diets.
Determination of contaminants in food
Authors: FOLKES D. J.
Published: October 2007

Atomic absorption spectroscopy, chromatography methods and mass spectrometry have had a major impact on the determination of contaminants and the limits of determination are reported. Specific examples of contaminants discussed are arsenic, lead, mercury, cadmium, organochlorine pesticides, polynuclear aromatic hydrocarbons, polychlorinated biphenyls, vinyl chloride monomer, styrene and nitrosamines.
Human metabolic response to exercise
Authors: WILLIAMS C.
Published: October 2007

The energy necessary to support prolonged submaximal exercise is provided by the aerobic metabolism of carbohydrate and fatty acids. Carbohydrate is stored as glycogen, a polymer of glucose, in the liver and in the skeletal muscles, whereas the fatty acids used by working muscles are mainly derived from triglycerides stored in white adipose tissue cells. The relative contributions of carbohydrate and fatty acids to muscle metabolism depend on the relative exercise intensity. The relative exercise intensity is defined as the oxygen cost of the exercise (V02) expressed as a percentage of the individual's maximum oxygen uptake (% V02 max). At exercise intensities which represent a large % V02 max for an individual, muscle glycogen is the main contributor to muscle metabolism. Fatigue is associated with the depletion of the limited intramuscular glycogen stores. When a carbohydrate‐rich diet is consumed during recovery after exercise, the muscle glycogen stores are increased above theirpre‐exercise concentrations. Thus an exercise and diet regime has been developed to exploit the glycogen supercompensa‐tion phenomenon and so increase endurance capacity.
Fluid and electrolyte balance in prolonged exercise
Authors: MAUGHAN R. J.
Published: October 2007

Due to the low efficiency of the metabolic process, large amounts of heat are produced when the demand for energy is high. Since body temperature must be maintained within narrow limits, the excess heat must be dissipated and the only heat loss mechanism which can cope with high rates of heat production is evaporation of sweat from the skin; during exercise in the heat, sweat rates may exceed 2 litres/hour. Total losses in events such as marathon races may be as much as 8 per cent of body weight. In addition to water loss, some depletion of electroytes will occur, though this is generally of lesser importance. The fluid loss is distributed among plasma extracellular and. intracellular water compartments in varying proportions. From the point of view of the ability to continue working, maintenance of plasma volume is the major consideration; even small decreases in plasma volume impair exercise tolerance. The ability to replace fluid losses during exercise is limited by the rates of gastric emptying and intestinal absorption, which fall far short of the rate of loss during severe exercise. Replacement of electrolyte losses can normally wait until the post‐exercise period.
Dietary intake and smoking, social class and season
Authors: FEHILY ANN M.
Published: October 2007

Associations between nutrient intakes and each of the following are discussed: season, social class and smoking habit. Examination of recent data suggests that seasonal variation in nutrient intakes is minimal. Social class has some effect on intakes of energy and carbohydrate, manual workers tending to have greater intakes than non‐manual workers. Smoking habit has the greatest effect on nutrient intakes, smokers tending to have lower intakes of several vitamins and minerals compared with non‐smokers, although total energy intakes are similar.
Practical use of nutrition labels
Authors: YEOMANS LESLEY
Published: October 2007

Nutrition information on food labels is intended to help people make an informed choice of food. Information alone is not sufficient ‐ it must be understood and be capable of being used. This survey provides evidence that some concepts and terms are not understood. They either need reconsidering or a comprehensive education programme is needed to improve knowledge and understanding.
Potato ‐ a gift from the Andes
Authors: WOOLFE JENNIFER A.
Published: October 2007

The potato is a source of high‐quality protein, having a particularly favourable lysine content, which makes it a useful supplement to lysine‐deficient staples. It contains significant quantities of dietary fibre and is the most important source of ascorbic acid in the British diet, as well as supplementing thiamin, niacin, folic acid, vitamin B6 and pantothenic acid, and the minerals iron, copper, zinc and phosphorus.
Immunoassays in food analysis
Authors: ALLEN J. C.
Published: October 2007

Immunoassays have found considerable application in clinical diagnosis, but have so far had surprisingly little impact on food analysis. This situation should now change, with the advent of the first commercially‐produced immunoassay kits specifically for food analysis. Immunoassays differ from other modern methods of analysis in that the high technology resides in the molecules rather than the apparatus. They are thus easy to perform, sensitive, specific and relatively inexpensive. Since they may be adapted for the determination of food toxins, antinutritional factors, additives, vitamins, etc., they offer considerable potential to the nutritional analyst.
Diet and pregnancy
Authors: PASSMORE R.
Published: October 2007

In the past 50years the number of babies who are stillborn or die in the first few weeks of life has fallen dramatically. This is attributed largely to improvements in social conditions and to improved nutrition during childhood and adolescence.

The majority of women who normally eat a varied diet can enjoy their normal foods during pregnancy and require no specific dietary advice other than that which applies to the population as a whole.

The causes of low birth weight (a known risk factor for survival and normal development) and congenital defects remain a challenge to medical science.
Schools, nutrition and the wind of change
Authors: TURNER SHEILA A.
Published: October 2007

Current thinking in education emphasizes the need to make teaching relevant to everyday life and to integrate studies. Nutrition education is an area which can contribute to and benefit from this approach. Snack provision, planned and prepared by 4 to 7year olds; the development of school gardens; the involvement of parents in the selection of items for schools meals; the provision of food related teaching materials by the Association of Science Education and the development of nutrition education guidelines incorporating in‐service training for teachers, are some of the activities which can be seen in schools today.
Fat in baked products
Authors: HODGE D. G.
Published: October 2007

The fat content of biscuits ranges from 5‐20 per cent and from 9‐20per cent for cakes. Cream fillings may be significant additional contributors. Fat has a major functional role to play since it is able to occlude air. Additionally, fat improves eating quality by contributing to “mouthfeel” and carrying flavour. This paper, in the light of the COMA (1984) report “Diet and Cardiovascular Disease”, considers the possibilities for altering the composition of the fat to reduce the proportion of saturated fat and the reduction of the fat content of recipes.
Iron availability – the implications of short‐term regulation
Authors: FAIRWEATHER‐TAIT SUSAN J.
Published: October 2007

The availability of iron depends on a number of dietary and physiological variables, and it is the sum of all these factors that ultimately determines iron status of the body. Iron homeostasis is almost certainly regulated by intestinal absorption via the mucosal cells, the mechanism of which is not yet fully understood. However, studies in animals and man have clearly shown that absorption is influenced by iron status, since the capacity for absorption is enhanced in iron‐deficiency (long‐term regulation), and also by the amount of iron ingested during the days preceding an absorption test (short‐term regulation). Evidence exists to support the hypothesis that the latter regulation is dependent on local effects of iron in the lumen of the intestine; it may well be the feedback mechanism whereby iron homeostasis is maintained in the presence of constantly fluctuating levels of iron. In iron absorption studies, it is important that this short‐term regulation is taken into account in terms of adequate dietary control of experimental subjects.
Nutrition and immunity
Authors: MILLER KLARA
Published: October 2007

It is well recognised that dietary factors play an important role in maintaining immune defences. Malnourished populations are known to have increased incidence and duration of infectious diseases, and data from numerous clinical and experimental studies have demonstrated impaired immunocompetence in the malnourished host. Restoring the food supply to an affected individual restores cell‐mediated immunity, except when malnutrition has occurred during foetal development. The developing immune system is particularly susceptible to nutritional deprivation. The problem of malnourishment is not restricted to developing countries. Malnutrition has been reported among hospitalized patients, generally as a result of illness but also as a consequence of surgery and sometimes from inappropriate feeding regimes. Alterations of the immune response can be demonstrated in obesity as well as in the malnourished state, and excess intake of polyunsaturated fatty acids (PUFA) has been shown to suppress immunity. Vitamins and trace minerals are also important in maintaining immunocompetence. Selenium and vitamin E have enhancing effects, probably due to their ability to prevent peroxidation of PUFA, and deficiency of pyridoxine (B6), zinc and vitamin A has been associated with impairment of immune functions. Knowledge gained of the interactions between nutritional factors and immunity offer the possibility of altering dietary regimes in order to modulate immune function and thus improve resistance to infectious disease and other diseases associated with impaired immunity.
Styles of life and death
Authors: COTTRELL R. C. , SOMMERVILLE MARNIE
Published: October 2007

Different countries show remarkably varied rates of death from coronary heart disease and other chronic diseases. Among developed communities, however, life expectancy is remarkably similar. This article addresses the proposition that diet has a determining influence on coronary heart disease (CHD) death rates and ipso facto on total mortality rates.
The importance of the gastrointestinal microflora to the nutrition of the host
Authors: COATES MARIE E.
Published: October 2007

The microflora of the gastrointestinal tract is responsible for considerable metabolic activity which could have beneficial or detrimental effects on the host. In gnotobiotic animals it has been clearly demonstrated that gut microorganisms synthesize vitamin K and the B complex, take part in the degradation and synthesis of proteins and other nitrogenous compounds, hydrogenate polyunsaturated fatty acids and effect extensive transformations of bile acids and sterols. In non‐ruminants the greatest microbial activity occurs in the lower gut, distal to the main areas of absorption, so that the end‐products are not readily utilized by a non‐coprophagous host. Human subjects on a low protein intake may derive some benefit from microbially recycled nitrogen but in subjects on adequate diets the presence of a microflora imposes a small demand on the host's nutrient economy. This is offset by the protection afforded by the “normal” gut microflora which provides an effective barrier against invasion by pathogens.
Composition of oils and fats
Authors: ROSSELL J. B.
Published: October 2007

Knowledge of the compositions of oil is important in consideration of the dietary influence of the oil, and also in international trade where dug classification and monetary value will be assessed from purity criteria. The Leatherhead Food R A has examined almost 600 samples of authentic vegetable oils and has established new and improved compositional criteria. A series of International Symposia held at Leatherhead have also substantiated and enhanced this information.

The most important aspect of an edible oil's composition is its fatty acid composition, and data for a number of vegetable, animal and fish oils and fats are compared. The distribution of the fat& acids in the component triglycerides is also considered, as the acids at the glyceride 2‐position have a different composition from those at the I and 3 positions. This can be an important purity aspect, and may also have dietary implications as human milk fat is known to concentrate palmitic acid at the 2‐position.

The concentrations of minor components such as vitamins A, D and E, and the sterols such as cholesterol and brassicasterol, are also mentioned.

Compositional characteristics are compared from the separate viewpoints of nutritional value and purity assessment of the oil.
The EEC Scientific Committee for Food
Authors: HAIGH R.
Published: October 2007

The article describes the origins of the EEC Scientific Committee for Food, its terms of reference, working methods and achievements. The committee's past, present and future programmes are reviewed.
60 years of research at the Dunn Nutrition Unit
Authors: PAUL ALISON A.
Published: October 2007

The Medical Research Council's Dunn Nutrition Unit in Cambridge celebrates its Diamond Jubilee this year. This article traces its foundation and some of the factors that have influenced its research activities over the past 60 years.
Chernobyl fallout: measurements in Cambridge
Authors: PALMER K. E. , SZAZ K. F.
Published: October 2007

Following the Chernobyl accident, gamma‐ray measurements were made on environmental samples, water, milk and on people. Iodine 131, caesium 134 and caesium 137 contamination was identified, activities were estimated and radiation doses calculated. Slight, but temporary increases in 131 I were observed in grass, milk and in the human body. Increased 137 Cs was very much less than that observed in the nuclear test fall out era of 1963. Total exposure of Cambridge residents due to the Chernobyl accident was estimated as equivalent to 3 days background radiation.
Psychoactive suostances in food
Authors: HAWTHORN J.
Published: October 2007

The term ‘drug’ originally referred to medicinal substances, but is now used to describe substances which interrupt normal physiological processes, and, in common usage, is associated with addictions. Many substances with such properties occur naturally in the raw materials—cereals, root vegetables, green vegetables, fruits, spices and some species of fish — which are in use on a regular basis as food and generally without obvious ill‐effects. This article, which describes some of these, is mainly based on a more formal and fully referenced paper.1 Does the presence of these substances unconsciously influence our food selection?
Brain mechanisms in the control of food intake—30 years on
Authors: BLUNDELL J. E.
Published: October 2007

Do brain systems exist which control not only increases or decreases in food intake, but also bring about specific changes in the size and distribution of meals consumed, alter the selection of particular macronutrients and adjust feeding responses to the perceived pleasantness (hedonic value) of the food? A cautious yes can be given to each of these questions. Moreover, since most experimental work has been carried out on the brains of animals, we can also ask how well these animal data relate to the human condition; given the methodological issues involved in making such inferences, the answer is remarkably well.
Dietary supplements
Authors: BENDER ARNOLD E.
Published: October 2007

Twenty per cent of the public buy vitamin supplements and a smaller but growing number of dedicated customers buy the products of the health food business. Yet most nutritionists and dietitians say these are quite unnecessary; everything we need can be obtained from the diet. Estimates of nutrient intakes always show a number of individuals well below the acceptable range but with no evidence of any clinical, subclinical or biochemical risk, until recently. Now we have claims that blunderbuss dietary supplementation affects development, behaviour and even IQ. Is this true? Is it applicable to the whole population, to young developing children, to those whose diet is deficient, or will it remain unconfirmed as are the claims for vitamin C and the common cold?
Fashions in nutrition
Authors: HOLLINGSWORTH DOROTHY F.
Published: October 2007

The development of nutritional knowledge and related advice over a century and a half is sketched through the seven eras of: proximate principles of foods; vitamins; energy; protein; controversy about fats; fear of food additives; and reaction to overindulgence. The conclusion is reached that as basic knowledge is strengthened through new findings, interpreters need to be cautious.
Nutrition and diets for endurance runners
Authors: EASTWOOD MARTIN , EASTWOOD MATTHEW
Published: October 2007

The average runner does not require a special diet except to maintain a desired weight. Individuals wishing to lose weight by running must run more than 9 miles a week for as much as a year to achieve weight loss. The muscle glycogen content is a limiting factor in the stamina required to run regularly for more than one and half hours. The levels necessary for endurance running can be achieved and maintained by a daily carbohydrate intake of 500 g a day. During marathon runs it is essential to drink water at regular intervals along with some glucose.
Food labelling ethics
Authors: Conning David M.
Published: October 2007

“I am aware that the industry would find guidance on the criteria to be used in establishing such claims useful in the labelling and marketing of their products”
Oats reassessed
Authors: LEEDS ANTHONY R.
Published: October 2007

Oats, growing well in cool, wet climates, were probably first exploited by Iron Age farmers, and remained an important cereal in some parts of the United Kingdom until the early nineteenth century. Following the decline in cereal (and therefore dietary fibre) consumption until the late 1970's, there is now increasing use of high fibre foods including oats. The relatively high protein content and its characteristic amino acid pattern, the high polyunsaturated fatty acid content of the lipid fraction, the high amylose starch and the presence of oat gum are all features which make oats a highly desirable food for the general population as well as those with diabetes or high blood cholesterol. Large doses (150 g dry weight/day) of rolled oats have sometimes been required to reduce blood cholesterol, but recent evidence suggests that 60 g/day (one large bowl of porridge) can effectively provide further benefit than that of a low fat diet. Recent enthusiasm for preventing coronary heart disease by educational campaigns and by screening to identify those at high risk, means that foods which have cholesterol lowering properties should now be actively promoted as part of “healthy heart” campaigns.
Energy expenditure in human pregnancy
Authors: PRENTICE ANDREW M.
Published: October 2007

Pregnancy and lactation are the most active anabolic phases of adult life and require marked changes in energy metabolism even in humans, in whom the energetic stress of reproduction is slight compared to most other species. Studies of the energetics of pregnancy started in the early 1900's when interest focused on the metabolism of the fetus in utero. More recently attention has turned to the implications of pregnancy for the mother herself. Data from the latest published studies now suggest that a physiological mechanism exists which can monitor a mother's energy stores and the adequacy of her diet during pregnancy, and can modify her metabolism accordingly. In particular, potent energy‐sparing adaptations have been demonstrated in under‐nourished mothers. Such adaptations would be anticipated to have important survival value when dietary intake is marginal. They have also been demonstrated to occur in some affluent women and therefore have implications when setting recommended dietary allowances for all women.
The nutritional effects of microwave heating
Authors: RYLEY JANICE
Published: October 2007

Microwave energy is mainly used for the reheating of cooked foods after chilled or frozen storage and the domestic prime cooking of a relatively small range of items. Comparison of the time‐temperature history in foods heated conventionally and by microwave indicates that microwave heated products should be nutritionally comparable to or better than their conventional counterparts, but the results of studies are sometimes conflicting. This can be attributed to variability in the performance of microwave ovens, difficulties involved in temperature measurement, which make experimental conditions difficult to define, and to the occurrence of “focalised” regions of high temperature in microwaved products.
Diet and coronary heart disease
Authors: CONNING DAVID M.
Published: October 2007

The controversy over the role of diet in the development of coronary heart disease (CHD) continues. Most studies of dietary involvement have concentrated on the possible nutritional basis of the accepted risk factor ‐ raised serum cholesterol. In animals, although high fat diets, particularly high saturated fatty acid diets, cause raised serum cholesterol levels, myocardial infarction rarely occurs. In human studies initial insight into the importance of dietary fat level and fatty acid composition was gleaned from international studies. Within population studies supported the association of raised serum cholesterol concentration with CHD in males up to 60years of age, and recognised the significance of the type of serum cholesterol, currently thought to be under genetic control. Although intervention studies have shown that high serum cholesterol levels can be reduced by dietary means, there has been no convincing evidence of a reduction in total mortality. An imbalance in the formation of inhibitors and promoters of platelet aggregation from polyunsaturated fatty acids in the diet is postulated as a possible nutritional basis for the formation of a thrombus in the coronary artery.
The safety and wholesomeness of irradiated foods
Authors: HAWTHORN JOHN
Published: October 2007

The current interest in extending the shelf life of ‘fresh’ foods and the upward trend of food poisoning make food irradiation an important additional technology. Used as a ‘pasteurising’ process it is remarkably gentle — as yet there is no generally applicable method of detecting that it has occurred. It does not make food radioactive, and intensive research studies have not shown any toxic effects associated with the process. Because it is very gentle compared to heating processes, it does not destroy bacterial toxins so that it cannot make spoiled food safe or palatable. Some losses of vitamins occur as in all methods of food preparation and processing. There are enormous advantages both for the manufacturer and the consumer in the controlled application of food irradiation which on balance, are of greater benefit than the minor disadvantage of nutrient losses comparable to current processing methods.
Nutrition for athletes
Authors: FLYNN A. , CONNOLLY J. F.
Published: October 2007

Athletes require appropriate body composition, power to move and stamina. The paper discusses the role of “good nutrition” in relation to these objectives during training and prior, during and after the event, emphasising the basic principles involved.
Making the most of computers in nutrition education and research
Authors: WISE A.
Published: October 2007

Computers can be used for a wide range of educational and research purposes in addition to the well‐known function as a rapid means of calculating nutrient intakes. The paper describes an example whereby data are entered using an interactive program which is operated by the use of self‐explanatory commands and provides on‐line help facilities. When data have been checked and basic nutritional calculations performed, the data can be stored and used for the analysis of the frequency and distribution of foods and meals, the variety of the diet and the food habits of different groups of the population. The information gathered can be useful in the construction of nutrition education programmes and will even give dietary advice.
Mutagens in cooked foods — and the assessment of their potential risk to health
Authors: ROWLAND IAN , ANDERSON DIANA
Published: October 2007

When meat or fish is cooked, a number of mutagenic pyrolysis products may be formed. The amounts produced depend on the type of food and the cooking conditions used. More mutagenic activity is associated with the cooking of muscle protein than with organ meat such as liver and kidney. Grilling and frying, because of the higher surface temperatures generated, produce more mutagenic activity in meat than do other methods of cooking. The quantities of mutagens formed, even by frying, are very small (about 20ug/kg), but they are, nevertheless, a cause for concern because these compounds are amongst some of the most potent mutagens known. Furthermore, they bind to DNA in vivo and, when fed to rats and mice, induce tumours in various organs, including liver and the intestine. However evidence is accumulating that other dietary components can influence the genotoxic activity of the ‘cooked food mutagens’. For example, dietary fibre reduces the activity of the compounds in mice, whereas feeding quercetin, a flavonoid found in many vegetables, increases the mutagenic activity in vivo.
1992 and the Consumer
Authors: FOSTER ANN
Published: October 2007

This paper summarises the journey so far towards the ‘single market’. Consumers may expect to benefit from increased choice and cheaper prices but the possibility that quality, as judged by % of characterising ingredient, will be lowered, is a cause for concern. The consumer will have to rely increasingly on labels, assuming that the label information is adequate. Quantitative ingredient information is desirable but provides technical difficulties for manufacturers.

A voluntary ‘quality mark’ scheme could be a satisfactory replacement for compositional standards but would have to be carefully controlled by independent assessors. The abolition of frontier controls creates a dilemma between the desire to have free trade within the community and the need to give a high priority to public health.
The impact of 1992 on food law
Authors: COCKBILL CHARLES A.
Published: October 2007

The essential purpose of food law is consumer protection while quality judgement is a matter for the individual, based on informative labelling.

Although the Council has agreed major frameworks directives, much detailed work is still required including; an agreed common list of food additives; the problems of the constituents of packaging materials and their possible migration into food; the assessment of quality of dietary products for their declared aims; limits for environmental contaminants; the approach to be adopted for biotechnology products and the labelling of foods containing ingredients which have been irradiated.