bluuebunny/crossref_metadata_2025 huggingface dataset:
Modification and bio‐testing of polyethylene films
Authors: Smokal V. , Krupka O. , Kolendo A.
Published: February 2011

New azidobenzenesulfonamides were synthesized and their photochemical properties were investigated. The surface modification of polyethylene (PE) films was carried out by using new azidobenzenesulfonamides was carried out.Antimicrobial activity of PE films with sulfonamide moiety was screened for vitro in the following bacterial: Staphylococcus aureus, Escherichia coli, Mycobacterium luteum. Preliminary screening of PE films with sulfonamide moiety revealed their inhibitory action against some kinds of bacteria and fungi.
Validation of the pelvic floor inventories Leiden (PelFIs) in English
Authors: Voorham‐van der Zalm Petra J. , Berzuk Kelli , Shelly Beth , Kamin Bernadette , Putter Hein , Lycklama à Nijeholt Guus A.B. , Pelger Rob C.M. , Stiggelbout Anne M.
Published: February 2011

Aims

To evaluate the validity and reliability of the English translation of an interviewer‐administered pelvic floor questionnaire, the “Pelvic Floor Inventories Leiden” (PeLFIs) for women, which addresses complaints of prolapse, bladder, and bowel dysfunction, pelvic floor pain and/or sexual dysfunction related to pelvic floor dysfunction.

Methods

The formal forward–backward translation of the PeLFIs was performed by bilingual Dutch/English translators. The final English version was administered to healthy volunteers (N = 94) and patients (N = 180) in Canada and the United States. Psychometric properties of the English version were examined, including internal consistency, test–retest reliability, content, and construct validity. Internal consistency was measured using Cronbach's alpha. Test–retest reliability was assessed by intraclass correlation coefficients. Construct validity was established by comparing scores in healthy volunteers and patients (using t‐tests) and by intercorrelating domains.

Results

The forward–backward translation of the English version of the PeLFIs was consistent with the original Dutch questionnaire. In total, 274 questionnaires were administered. The retest was administered 2 weeks after the initial PeLFIs interview. Internal consistency of the questionnaire was 0.88 for the total scale. Cronbach's alpha of the domains ranged from 0.71 to 0.95. For the test–retest reliability, the agreement rate between the two tests exceeded 95% and the intraclass correlation ranged from 0.6 to 0.8. The differences between healthy volunteers and patients were statistically significant for all domains, but did not exceed the minimal important difference for some domains. Correlations between the domains were moderate to high.

Conclusions

The PeLFIs questionnaire has been translated successfully into English and in its evaluation has shown adequate internal consistency and reliability. 30:536–540, 2011. © 2011 Wiley‐Liss, Inc.
Analysis of the singular function boundary integral method for a biharmonic problem with one boundary singularity
Authors: Christodoulou E. , Elliotis M. , Georgiou G. , Xenophontos C.
Published: February 2011

In this article, we analyze the singular function boundary integral method (SFBIM) for a two‐dimensional biharmonic problem with one boundary singularity, as a model for the Newtonian stick‐slip flow problem. In the SFBIM, the leading terms of the local asymptotic solution expansion near the singular point are used to approximate the solution, and the Dirichlet boundary conditions are weakly enforced by means of Lagrange multiplier functions. By means of Green's theorem, the resulting discretized equations are posed and solved on the boundary of the domain, away from the point where the singularity arises. We analyze the convergence of the method and prove that the coefficients in the local asymptotic expansion, also referred to as stress intensity factors, are approximated at an exponential rate as the number of the employed expansion terms is increased. Our theoretical results are illustrated through a numerical experiment. © 2011 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2011
Innovative Optikdesigns durch Präzisionsblankpressen
Authors: Nollau Sebastian , Kunz Andreas , Rübenach Olaf , Pongs Guido
Published: February 2011

Die neue Technologie des Präzisionsblankpressens ermöglicht hohe Präzision trotz niedriger Kosten in der Herstellung anspruchsvoller optischer Komponenten. Diese Fertigungstechnologie ist leistungsfähig genug, um verschiedenste komplexe Geometrien wie beispielsweise Asphären, Arrays oder diffraktive Optiken herzustellen und kostenaufwändige herkömmliche Verfahren wie Schleifen und Polieren zu substituieren. Um die Fähigkeiten der Technologie optimal ausnutzen zu können, wurde in den letzten Jahren eine entsprechende Befähigung der gesamten dazugehörigen Lieferkette von der Rohmaterialherstellung über die Formwerkzeugfertigung bis hin zur Messtechnik vorangetrieben.
Electron‐beam crystallized large grained silicon solar cell on glass substrate
Authors: Amkreutz D. , Müller J. , Schmidt M. , Hänel T. , Schulze T. F.
Published: February 2011

Thin film hetero‐emitter solar cells with large‐grained poly‐silicon absorbers of around 10 µm thickness have been prepared on glass. The basis of the cell concept is electron‐beam‐crystallization of an amorphous or nanocrystalline silicon layer deposited onto a SiC:B layer. The SiC:B layer covers a commercially well available glass substrate, serving as diffusion barrier, contact layer and dopand source. For silicon absorber deposition a low pressure chemical vapour deposition was used. The successively applied e‐beam crystallization process creates poly‐silicon layers with grain sizes up to 1 × 10 mm2 with low defect densities. The high electronic quality of the absorber is reflected in open circuit voltages as high as 545 mV, which are realized making use of the well‐developed a‐Si:H hetero‐emitter technology. Copyright © 2011 John Wiley & Sons, Ltd.
Gettering in multicrystalline silicon wafers with screen‐printed emitters
Authors: Pletzer T.M. , Stegemann E.F.R. , Windgassen H. , Suckow S. , Bätzner D.L. , Kurz H.
Published: February 2011

In this paper, the gettering potential of phosphorus dopant pastes used in single‐sided screen‐printing processes is investigated including the consequences for essential solar cell parameters. These results are supported by minority carrier lifetime measurements with the quasi‐steady‐state photoconductance method and certified by the analysis of the recombination current density in solar cells on mc‐Si wafers. Copyright © 2011 John Wiley & Sons, Ltd.
Sequential support vector regression with embedded entropy for SNP selection and disease classification
Authors: Liang Yulan , Kelemen Arpad
Published: February 2011

Comprehensive evaluation of common genetic variations through association of single nucleotide polymorphism (SNP) structure with common diseases on the genome‐wide scale is currently a hot area in human genome research. For less costly and faster diagnostics, advanced computational approaches are needed to select the minimum SNPs with the highest prediction accuracy for common complex diseases. In this article, we present a sequential support vector (SV) regression model with embedded entropy algorithm to deal with the redundancy for the selection of the SNPs that have best prediction performance of diseases. We implemented our proposed method for both SNP selection and disease classification, and applied it to simulation data sets and two real disease data sets. Results show that on the average, our proposed method outperforms the well‐known methods of support vector machine recursive feature elimination (SVMRFE), logistic regression, classification and regression tree (CART), and logic regression‐based SNP selections for disease classification. © 2011 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 2011
A case of Leukonychia with scanning electron microscope observation
Authors: Wang Peng , Yang Hanjun , Ran Yuping , Li Conghui
Published: February 2011

Leukonychia is a medical term for white discoloration appearing on nails. The pathophysiologic mechanisms that cause white discoloration are not entirely clear. We processed a case of leukonychia with scanning electron microscope observation and found many crispy, obviously dissociated “layers” in the lower part of the white nail plate. The dissociated “layers” were composed of thick, loose, coarse keratin bundles intertwined with each other. We believe the dissociated “layers” are related to the clinically noted white discoloration appearing on the nails. SCANNING 33: 41–44, 2011. © 2011 Wiley Periodicals, Inc.
An approach to meta‐analysis of dose‐finding studies
Authors: Zohar Sarah , Katsahian Sandrine , O'Quigley John
Published: February 2011

The main goal of a Phase I dose‐finding study is the estimation of the maximal tolerated dose (MTD) from a set of available dose levels. For cytotoxic clinical trials in oncology, it is not unusual to find several phases I studies carried out on a new molecule or procedure. For instance, the molecule Sorafenib (which inhibits particular tyrosine kinase enzymes in several cancers) was used alone in five published clinical trials. Each clinical trial was conducted separately in different indications and the resulting data were never pooled in any way. No attempt was made to synthesize or combine the information from the different studies. For dose‐finding studies, the toxicity itself may not be related to disease. Integrating information across several Phase I trials may lead to improved inference on the dose level, or levels, corresponding to the MTD. Under strong assumptions, we will provide more accurate estimates of the MTD. Under no assumptions a pooled analysis will perform no less well than several separate analyzes and, under intermediary assumptions, there still may be scope for gains. A difficulty is that many methods are sequential in nature so that, in order to group findings under a single heading, it is necessary to retrospectively analyze data obtained according to a dynamic sequential design. We propose a solution to this difficulty. The approach is illustrated via two real examples. Copyright © 2011 John Wiley & Sons, Ltd.
Covariate‐adjusted non‐parametric survival curve estimation
Authors: Jiang Honghua , Symanowski James , Qu Yongming , Ni Xiao , Wang Yanping
Published: February 2011

Kaplan–Meier survival curve estimation is a commonly used non‐parametric method to evaluate survival distributions for groups of patients in the clinical trial setting. However, this method does not permit covariate adjustment which may reduce bias and increase precision. The Cox proportional hazards model is a commonly used semi‐parametric method for conducting adjusted inferences and may be used to estimate covariate‐adjusted survival curves. However, this model relies on the proportional hazards assumption that is often difficult to validate. Research work has been carried out to introduce a non‐parametric covariate‐adjusted method to estimate survival rates for certain given time intervals. We extend the non‐parametric covariate‐adjusted method to develop a new model to estimate the survival rates for treatment groups at any time point when an event occurs. Simulation studies are conducted to investigate the model's performance. This model is illustrated with an oncology clinical trial example. Copyright © 2011 John Wiley & Sons, Ltd.
PCB 9 exposure induces endothelial cell death while increasing intracellular calcium and ROS levels
Authors: Yilmaz Bayram , Sandal Suleyman , Carpenter David O.
Published: February 2011

Cultured porcine endothelial cells were used to determine the effects of several congeners of polychlorinated biphenyls (PCBs) on cell viability and changes induced by these congeners on levels of intracellular calcium and reactive oxygen species (ROS). Cultured endothelial cells were prepared as a single suspension and run on flow cytometry. Cell viability, intracellular calcium, and ROS concentrations were simultaneously determined by using propidium iodide, Fluo‐3, and dihydrorodamine, respectively. The congeners tested included two coplanar tetrachlorinated congeners that have no ortho chlorines, PCBs 77 and 80, a tri‐chloro congener which does not have any ortho chlorine, PCB 39, a di‐ortho, tetrachlorinated congener, PCB 52, and a mono‐ortho congener, PCB 9. PCB 9 was cytotoxic at 5 μM within 5 min of exposure, and the toxicity increased with time and concentration. None of the other congeners showed consistent cytotoxicity. The cytotoxicity was roughly correlated with elevations in cellular ROS levels, but not with changes in intracellular calcium. To the best of our knowledge, toxicity of lower chlorinated, more volatile congeners such as PCB 9 has not been previously studied. These observations may be taken to explain the elevated risk of cardiovascular disease previously reported among residents living near to hazardous waste sites containing PCBs. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Avulsion of the puborectalis muscle is associated with asymmetry of the levator hiatus
Authors: Dietz H. P. , Bhalla R. , Chantarasorn V. , Shek K. L.
Published: February 2011

Objective

To determine the degree of levator hiatal asymmetry in women with unilateral avulsion of the puborectalis muscle in order to estimate the likely effect of successful reconstruction.

Methods

We reviewed datasets of women seen between May 2005 and January 2009 in a tertiary urogynecological unit. Archived ultrasound volume datasets were analyzed for hiatal dimensions and puborectalis muscle trauma in patients with unilateral avulsion.

Results

From 929 eligible datasets we identified 71 patients with isolated complete unilateral tears. Unilateral avulsion was associated with a significant increase in hiatal area (P ≤ 0.002). Relative to a hypothetical normal hiatus (intact hemi‐area × 2), avulsion was associated with a larger hiatus on Valsalva maneuver (+2.1 cm2 or 7%).

Conclusions

Unilateral puborectalis muscle avulsion results in an asymmetric increase in the size of the levator hiatus. This increase is relatively minor, accounting for < 10% of hiatal area. Surgical repair of an avulsion may have only limited effects on hiatal dimensions. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Adapting to climate change to sustain health
Authors: Woodward Alistair , Lindsay Graeme , Singh Sudhvir
Published: February 2011

Adaptation is necessary because climate change has gained considerable momentum. Deep cuts in emissions must be made rapidly to avoid warming of 2° above preindustrial levels but this is most unlikely, given present trends. It is possible that warming may in fact reach 4°C or more by 2100. Risks to health result principally from the effects of climate change on local food production, severity and frequency of storms and floods, threats to water supplies, and the direct effects of heat. The health sector has an important role protecting health in times of climate change. However, other sectors must be involved as well—steps taken in agriculture, urban planning, water and civil defence, for instance, will have implications for prevention of illness and injury. We offer a framework for planning adaptation, taking into account present climate‐sensitive health problems, control options, and constraints. WIREs Clim Change 2011 2 271–282 DOI: 10.1002/wcc.103

This article is categorized under:

Vulnerability and Adaptation to Climate Change > Learning from Cases and Analogies
Graphical user interfaces
Authors: Martinez Wendy L.
Published: February 2011

This article provides a brief introduction to graphical user interfaces or GUIs. The first section defines graphical user interfaces, describes interface components, and the different types of GUIs. This is followed by a short discussion of GUI design principles and descriptions of some tools for easily creating GUIs. The article concludes with some examples of GUIs that would be of interest to researchers and statisticians. WIREs Comp Stat 2011 3 119–133 DOI: 10.1002/wics.150

This article is categorized under:

Software for Computational Statistics > Software/Statistical Software
Surgeon’s occupational exposure to nitrous oxide and sevoflurane during pediatric surgery
Authors: Byhahn Christian , Heller Klaus , Lischke Volker , Westphal Klaus
Published: February 2011

Health hazards from occupational exposure to trace concentrations of anesthetic gases cannot be definitively excluded. The aim of the study was to determine the surgeon’s occupational exposure to nitrous oxide and sevoflurane during pediatric surgical procedures. Twenty young children (age <10 years) and five teenagers (age > 10 years) underwent elective abdominal surgery under general inhalational anesthesia. The operating room was equipped with modern air conditioning and waste anesthetic gas scavenger. Levels of both nitrous oxide and sevoflurane were determined in the breathing zone of the surgeon and the anesthesiologist during the operative procedures by means of a direct‐reading photoacoustic infrared spectrometer. Both the surgeon and the anesthesiologist were exposed to low concentrations of the inhalational agents used. Exposure to sevoflurane and nitrous oxide was clearly higher during surgery in young children than during operative procedures in teenagers. Nonetheless, the concentrations of these agents were well below the threshold limits of 25 ppm for nitrous oxide and 2 ppm for sevoflurane recommended by the National Institute of Occupational Safety and Health. General anesthesia results in operating room air pollution with inhalational anesthetics. Under modern air conditioning, personnel’s occupational exposure is low, and inhalational anesthesia is safe from the standpoint of modern workplace laws and health care regulations. Nonetheless, all efforts must be taken to maintain occupational exposure at this low level.
Lateral approach to laparoscopic repair of left diaphragmatic ruptures
Authors: Goudet Pierre , Cheynel Nicolas , Ferrand Loïc , Peschaud Frédérique , Steinmetz Jean‐Philippe , Letourneau Bernard , Isnardon Jean‐Paul , Noirot Marie‐Thérèse , Poli Laurencia , Freysz Marc , Cougard Patrick
Published: February 2011

Video‐assisted repairs of traumatic diaphragmatic ruptures have been described where thoracoscopy or laparoscopy in the supine position were used. This study aims to validate a new lateral laparoscopic approach for left diaphragmatic repairs. Six consecutive patients were operated on for left diaphragmatic rupture using a lateral approach (Gagner’s position). A series of 362 consecutive patients presenting with abdominal or thoracic trauma with or without diaphragmatic rupture over a 2‐year period were reviewed retrospectively. Contraindications for immediate or delayed lateral laparoscopic approach were studied. The lateral approach provided complete visibility of the subdiaphragmatic space, easy reduction of herniated organs, easy thoracic inspection and cleaning, the use of low peritoneal pressure, full range of instrumental motion, and rapid diaphragmatic repair. No operative mortality or morbidity was noted. Altogether, 14% to 50% of the patients with diaphragmatic ruptures were candidates for immediate lateral laparoscopic repair. Associated spleen injury in 50% of the cases was the main contraindication. The lateral laparoscopic approach provides better exposure of the diaphragm on the left side and facilitates the diaphragmatic repair especially with a large herniation. Immediate repair is possible in selected cases (14–50%). There is no contraindication in case of delayed diagnosis.
Cachexia in heart disease: highlights from the ESC 2010
Authors: Kung Thomas , Szabó Tibor , Springer Jochen , Doehner Wolfram , Anker Stefan D. , von Haehling Stephan
Published: February 2011

Cardiac cachexia is a co‐morbidity that may develop in terminal stages of chronic heart failure (CHF). Up to 15% of ambulatory patients with heart failure are affected. Over the last decades, cardiac cachexia and alterations in muscle metabolism in heart disease have received increasing research interest. This article highlights some recent studies of cardiac cachexia that were presented at the annual meeting of the European Society of Cardiology in September 2010 in Stockholm, Sweden. Studies presented here were focused on effects of exercise training and protein degradation, particularly into the role of the ubiquitin–proteasome complex and its ubiquitin ligases MuRF‐1 and MAFbx. Exercise training in patients with CHF was found to increase maximal oxygen consumption and to reduce MuRF‐1 expression. Lysosomal muscle degradation does not seem to play a major role in patients with CHF, however, inflammatory cytokines such as tumor necrosis factor‐a trigger muscle protein degradation. Other studies found that the serum levels of the adipokine adiponectin are elevated in patients with CHF and that these levels may be correlated with muscle mass, muscle strength in the arms, or with trunk fat mass. Another study showed that the expression of myostatin in skeletal muscle, a negative regulator of muscle growth that is essential for normal regulation of muscle mass, is decreased in spontaneously hypertensive rats with heart failure compared with control animals. This is also true for follistatin, a powerful antagonist, and its potential as a biomarker of muscle wasting. These findings may pave the way for effective treatment approaches to cardiac cachexia.
The relation between small nerve fibre function, age, disease severity and pain in Fabry disease
Authors: Biegstraatenl Marieke , Binderl Andreas , Maagl Rainer , Hollakl Carla E.M. , Baronl Ralf , van Schaikl Ivo N.
Published: February 2011

Background: Small fibre neuropathy supposedly causes pain in Fabry patients, but the relationship between small nerve fibre function and pain severity is unclear.

Methods: A cohort of 15 male and 33 female Fabry patients was studied making use of a quantitative sensory testing protocol, disease severity measures and pain scales to investigate the relationship between nerve fibre function, age, disease severity and pain intensity.

Results: Male Fabry patients exhibited an abnormal cold detection threshold and thermal sensory limen at the upper and lower limb, indicating Aδ‐fibre hypofunction. Female patients showed Z‐scores within normal range for all modalities. Nerve fibre function was worse at older age and with more severe disease. The overall severity of pain was mild, without significant differences between males and females. No linear relationship between pain severity and small nerve fibre function was identified.

Conclusions: In Fabry disease, no linear relationship exists between pain and small nerve fibre function. With older age and more severe disease pain may abate as nerve fibre function further deteriorates.
The Holocene thermal maximum and late-Holocene cooling in the tundra of NE European Russia
Authors: Salonen J. Sakari , Seppä Heikki , Väliranta Minna , Jones Vivienne J. , Self Angela , Heikkilä Maija , Kultti Seija , Yang Handong
Published: February 2011

To investigate the Holocene climate and treeline dynamics in the European Russian Arctic, we analysed sediment pollen, conifer stomata, and plant macrofossils from Lake Kharinei, a tundra lake near the treeline in the Pechora area. We present quantitative summer temperature reconstructions from Lake Kharinei and Lake Tumbulovaty, a previously studied lake in the same region, using a pollen–climate transfer function based on a new calibration set from northern European Russia. Our records suggest that the early-Holocene summer temperatures from 11,500 cal yr BP onwards were already slightly higher than at present, followed by a stable Holocene Thermal Maximum (HTM) at 8000–3500 cal yr BP when summer temperatures in the tundra were ca. 3°C above present-day values. A Picea forest surrounded Lake Kharinei during the HTM, reaching 150 km north of the present taiga limit. The HTM ended with a temperature drop at 3500–2500 cal yr BP associated with permafrost initiation in the region. Mixed spruce forest began to disappear around Lake Kharinei at ca. 3500 cal yr BP, with the last tree macrofossils recorded at ca. 2500 cal yr BP, suggesting that the present wide tundra zone in the Pechora region formed during the last ca. 3500 yr.
The Tragedy of theNomenklatura: Career Incentives and Political Radicalism during China's Great Leap Famine
Authors: KUNG JAMES KAI-SING , CHEN SHUO
Published: February 2011

A salient feature of China's Great Leap Famine is that political radicalism varied enormously across provinces. Using excessive grain procurement as a pertinent measure, we find that such variations were patterned systematically on the political career incentives of Communist Party officials rather than the conventionally assumed ideology or personal idiosyncrasies. Political rank alone can explain 16.83% of the excess death rate: the excess procurement ratio of provinces governed by alternate members of the Central Committee was about 3% higher than in provinces governed by full members, or there was an approximate 1.11‰ increase in the excess death rate. The stronger career incentives of alternate members can be explained by the distinctly greater privileges, status, and power conferred only on the rank of full members of the Central Committee and the “entry barriers” to the Politburo that full members faced.
Digestion rate of dietary starch affects the systemic circulation of lipid profiles and lipid metabolism-related gene expression in weaned pigs
Authors: Yin Fugui , Yin Yulong , Zhang Zhenzhen , Xie Mingyong , Huang Ju , Huang Ruilin , Li Tiejun
Published: February 2011

The present study was conducted to investigate the effect of digestion rate of dietary starch on postprandial systemic circulating glucose, insulin and lipid profiles, and the activity and gene expression of lipid metabolism-related enzymes in weaned pigs. A total of twenty-four weaned pigs, surgically fitted with a catheter in the jugular vein, were randomly assigned to three dietary treatment groups, representing the high digestion rate starch (HDRS) group, the moderate-digestion rate starch (MDRS) group and the low-digestion rate starch (LDRS) group. The amylopectin:amylose ratios in the diets of each group were 27·6:1, 27·6:8·5 and 1:27·6, respectively. The serum concentrations of glucose, TAG, total cholesterol, LDL-cholesterol and HDL-cholesterol in the HDRS group were increased to the peak point at postprandial 1·5, 2·5, 2·5, 1·5 and 1·5 h, those in the MDRS group were at postprandial 2·5, 3·5, 3·5, 3·5 and 3·5 h and those in the LDRS group were at postprandial 2·5, 3·5, 3·5, 1·5 and 3·5 h, respectively. The serum concentration of insulin in the HDRS group was higher (P < 0·05) than those in the MDRS group, and those in the MDRS group was also higher (P < 0·05) than those in the LDRS group at postprandial 0·5, 1·5 and 2·5 h, respectively. The serum concentrations of acetate, propionate and butyrate in the HDRS group were higher (P < 0·05) than those in the MDRS group, and those in the MDRS group were higher (P < 0·05) than in the LDRS group in each feeding cycle, in turn, respectively. The activity of fatty acid synthase (FAS) in the liver and abdominal adipose tissues, that of acetyl CoA carboxylase (ACC) in the myocardium and interscapular brown adipose tissues and that of the ATP-citrate lyase (ATP-CL) in the liver and interscapular brown adipose tissues in pigs of the HDRS group were higher (P < 0·05) than that of the MDRS group. The mRNA levels of FAS in the myocardium, liver and interscapular brown adipose tissues of pigs in the HDRS group were higher (P < 0·05) than those of the MDRS group. The activities and mRNA levels of FAS, ACC and ATP-CL in the myocardium, liver, abdominal and interscapular brown adipose tissues of the HDRS group were higher than those of the LDRS group. We conclude that the digestion rate of dietary starch affected not only the postprandial systemic circulating levels of glucose and insulin but also the lipid metabolism in weaned pigs. Dietary starch with higher digestion rate produces higher blood glucose and insulin response, ameliorates the blood lipid profiles and up-regulates the activity and gene expression profile of lipid metabolism-related genes in weaned pigs.
Long-term adequacy of exclusive breast-feeding: how scientific research has led to revised opinions
Authors: Whitehead R. G. , Paul A. A.
Published: February 2011

The present paper reviews the research of the authors and their colleagues over the past 20 years to provide improved nutritional and anthropometric guidelines for the assessment of lactational adequacy and for when the weaning process might be initiated. The nutritional guidelines are based on revised dietary energy requirements. The basic assumption is that since breast milk is a well-balanced food, if energy needs are satisfied so will those for essential nutrients. Energy requirements for young babies have been derived from the application of the doubly-labelled-water technique. This approach indicated that 460 kJ (110 kcal)/kg per d at 1 month and 397 and 355 kJ (95 and 85 kcal)/kg per d at 3 and 6 months respectively would be satisfactory for a nutrient content of high bioavailability. Translated into a breast-milk intake of 850 ml/d the latter would cover the dietary energy needs of the average child growing along the 50th centile until at least 4 months, but the typical child from many developing countries following the 25th centile until 6 months. The importance of revised growth reference values for infancy, equally crucial for assessing lactational adequacy, is also reviewed. In contrast with the shapes of earlier reference patterns, growth trajectories are different when babies are fed in accordance with modern paediatric advice. Mothers and health professionals using the older growth charts to assess the progress of a baby can be misled into assuming that the weaning process needs to be introduced sooner than necessary. Examples of this situation within the context of a developing country are provided.
Use of maternal reserves as a lactation strategy in large mammals
Authors: Oftedal Olav T.
Published: February 2011

The substrate demands of lactation must be met by increased dietary intake or by mobilization of nutrients from tissues. The capacity of animals to rely on stored nutrients depends to a large extent on body size; large animals have greater stores, relative to the demands of lactation, than do small animals. The substrate demands of lactation depend on the composition and amount of milk produced. Animals that fast or feed little during lactation are expected to produce milks low in sugar but high in fat, in order to minimize needs for gluconeogenesis while sustaining energy transfers to the young. The patterns of nutrient transfer are reviewed for four taxonomic groups that fast during part of or throughout lactation: sea lions and fur seals (Carnivora: Otariidae), bears (Carnivora: Ursidae), true seals (Carnivora: Phocidae) and baleen whales (Cetacea: Mysticeti). All these groups produce low-sugar high-fat milks, although the length of lactation, rate of milk production and growth of the young are variable. Milk protein concentrations also tend to be low, if considered in relation to milk energy content. Maternal reserves are heavily exploited for milk production in these taxa. The amounts of lipid transferred to the young represent about one-fifth to one-third of maternal lipid stores; the relative amount of the gross energy of the body transferred in the milk is similar. Some seals and bears also transfer up to 16–18 % of the maternal body protein via milk. Reliance on maternal reserves has allowed some large mammals to give birth and lactate at sites and times far removed from food resources.
Interactions of perturbations in intrauterine growth and growth during childhood on the risk of adult-onset disease
Authors: Yajnik Chittaranjan
Published: February 2011

The ‘fetal origins’ hypothesis (Barker, 1995) would predict that the rising epidemic of diabetes and CHD in India would be due to poor intrauterine growth of the Indian babies. While this explanation may be valid to an extent, the higher prevalence of these disorders in urban compared with rural India (where birth weights are lower) would suggest a significant role for postnatal factors. In a cohort of 477 children born in the King Edward Memorial Hospital, Pune, we found that at 8 years of age current obesity strongly predicted insulin resistance. When this effect was allowed for, low birth weight was significantly associated with insulin-resistance variables and other cardiovascular risk factors. Children who were born small but had grown heavy (or tall) were the most insulin resistant and had the highest levels of cardiovascular risk factors. Accelerated growth in relation to mid parental height was similarly predictive. Poor intrauterine growth also predicted higher central adiposity at 8 years of age. We have also studied maternal nutrition and fetal growth in six villages near Pune. A newborn Indian baby is small (2650 g, SD score (SDS) –1.6 compared with an average white Caucasian baby born in the UK) and ‘thin’ (ponderal index 2.45 kg/m3, SDS –1.2), but has preserved its subcutaneous fat (subscapular skinfold thickness SDS –0.6). The thinness of the Indian babies is due to poor muscle and small abdominal viscera. We have proposed this composition as the ‘thrifty phenotype’ (Hales & Barker, 1992) of Indian babies. Maternal size and intake of certain food groups during pregnancy were important determinants of the baby’s phenotype. Thus, the small Indian babies are programmed to deposit fat from their intrauterine life. Exaggeration of this tendency in later life is associated with insulin-resistance syndrome. Control of the insulin-resistance epidemic in India might depend on improved intrauterine development and prevention of childhood obesity.
Methodological approaches to assess body-weight regulation and aetiology of obesity
Authors: Marti Amelia , Miguel Carlos De , Jebb Susan A , Lafontan Max , Laville Martine , Palou Andreu , Remesar Xavier , Trayhurn Paul , Martinez J. Alfredo
Published: February 2011

Obesity, which is becoming one of the major health hazards in developed and developing societies, results from a long-term positive energy balance. Body-weight regulation and stability depend on an axis with three interrelated components: food intake, energy expenditure and adipogenesis, although there are still many unknown features concerning fuel homeostasis and energy balance. Biochemical processes are interconnected, and a separate consideration of each component is often useful for methodological purposes and to achieve a better understanding of the whole system. Thus, many different experimental approaches can be applied by using laboratory animals, cell culture or human subjects to unravel the molecular mechanisms which participate in body-weight regulation. Thus, both in vitro (cellular and subcellular models) and in vivo methods have dramatically increased our knowledge of weight control. Several strategies in obesity research are reported here, exploiting the opportunities of the molecular era as well as novel whole-body approaches, which will impact on the development of new targets for obesity management and prevention.
Part 1 Substrate metabolism in the metabolic response to injury
Authors: Romijn J. A.
Published: February 2011

In healthy subjects the metabolic response to starvation invokes regulatory mechanisms aimed at conservation of protein mass. This response is characterized by a decrease in energy expenditure and a progressive decrease in urinary N excretion. Many non-endocrine diseases induce anorexia and a decrease in food intake. However, in contrast to the metabolic reaction to starvation in healthy subjects, anorectic patients with serious diseases have increased energy expenditure and protein catabolism, associated with profound neuroendocrine alterations. These neuroendocrine changes are induced by two mechanisms. First, afferent nerves inform the central nervous system of tissue injury which results in neuroendocrine activation. Second, tissue injury stimulates the production of inflammatory mediators, which in turn results in neuroendocrine and metabolic effects. Although these metabolic changes enable the organism to survive short-lasting diseases by using endogenous substrates, in protracted serious diseases these changes will result in loss of functioning protein mass and may endanger survival. Moreover, tissue injury alters the metabolic responses to nutrition, reflected in the persistence of catabolism as long as serious tissue injury remains.
Phyto-oestrogens through the life cycle
Authors: Cassidy Aedin , Faughnan Marian
Published: February 2011

The growing interest in the role of phyto-oestrogens in human health has prompted scientists to evaluate the risk : benefit which would result from consuming high levels of these compounds at different stages of the life cycle. These compounds have been shown to exert a wide range of hormonal and non-hormonal activities in animals and in vitro, and these activities suggest plausible mechanisms for potential health effects in human subjects consuming phyto-oestrogen-rich diets. In addition, experimental and epidemiological data are available supporting the concept that phyto-oestrogen-rich diets exert physiological effects in vivo; however, their relative importance to human health remains to be elucidated. Our understanding of factors involved in their absorption and metabolism, including the role of intestinal microflora, is limited, and these factors together with dose-related effects may well be important in determining clinical efficacy.
Role of breast-feeding in managing malnutrition and infectious disease
Authors: Filteau Suzanne M.
Published: February 2011

Breast-feeding policy tends to be an emotive issue. International agencies recommend exclusive breast-feeding for 4–6 months followed by continued partial breast-feeding into the second year of life in order to promote infant and child health and minimize the damage caused by the malnutrition–infection cycle. To what extent are these recommendations supported by the experimental evidence? Are they a simplification for emotional reasons or public health purposes? Breast-feeding is believed to benefit infants because breast milk contains the ideal mix of nutrients for infants, because it contains factors which promote development of the infant’s gut and immune system and which prevent pathogen invasion, and because exclusive breast-feeding prevents intake of pathogens in food or water. However, some apparently contradictory evidence exists. First, in environments which are not highly contaminated breast-fed infants tend to growth falter relative to those fed formula. Second, in such environments partial breast-feeding is not associated with significantly increased gut damage relative to exclusive breast-feeding, suggesting that active promotion of gut development by breast-feeding is more important than simple avoidance of pathogens from other foods. Third, many immune factors in breast milk are probably present primarily to protect the mother, not the infant. Finally, breast milk itself may contain bacteria or viruses. This problem has come to the fore with the human immunodeficiency virus epidemic, since it is clear breast-feeding is an important mode of mother-to-child transmission. The present review will examine these challenges to the basis of the international infant feeding recommendations and will suggest that the science does actually support the policy.
Micronutrients and immune function in cattle
Authors: Spears Jerry W.
Published: February 2011

Complex inter-relationships exist between certain micronutrients, immune function and disease resistance in cattle. Several micronutrients have been shown to influence immune responses. The relationship between deficiencies of some micronutrients and disease resistance is less clear. A number of studies have indicated that Cr supplementation may improve cell-mediated and humoral immune response as well as resistance to respiratory infections in stressed cattle. With respiratory-disease challenge models Cr generally does not affect disease resistance. Deficiencies of Cu, Se, vitamin E and Co in cattle reduce the ability of isolated neutrophils to kill yeast and/or bacteria. Cu deficiency reduces antibody production, but cell-mediated immunity is generally not altered. However, Cu deficiency appears to reduce production of interferon and tumour necrosis factor by mononuclear cells. Numerous studies have linked low vitamin E and/or Se status to increased susceptibility of dairy cows to intramammary infections. In contrast to findings in laboratory animals, marginal Zn deficiency does not appear to impair antibody production or lymphocyte responsiveness to mitogen stimulation in ruminants. Co deficiency has been associated with reduced resistance to parasitic infections. It is well documented that vitamin A-deficient animals are more susceptible to various types of infections. β-Carotene, possibly via its antioxidant properties, may affect immune function and disease resistance independent of its role as a precursor of vitamin A.
Optimal intakes of protein in the human diet
Authors: Millward D. Joe
Published: February 2011

For protein, progress is slow in defining quantifiable indicators of adequacy other than balance and growth. As far as current requirements are concerned, only in the case of infants and children is there any case for revision, and this change is to lower values. Such intakes would appear to be safe when consumed as milk formula. In pregnancy, notwithstanding the concern that deficiency may influence programming of disease in later life, there is little evidence of any increased need, and some evidence that increased intakes would pose a risk. For the elderly there is no evidence of an increased requirement or of benefit from increased intakes, except possibly for bone health. For adults, while we now know much more about metabolic adaptation to varying intakes, there would appear to be no case for a change in current recommendations. As far as risks and benefits of high intakes are concerned, there is now only a weak case for risk for renal function. For bone health the established views of risk of high protein intakes are not supported by newly emerging data, with benefit indicated in the elderly. There is also circumstantial evidence for benefit on blood pressure and stroke mortality. With athletes there is little evidence of benefit of increased intakes in terms of performance, with older literature suggesting an adverse influence. Thus, given that a safe upper limit is currently defined as twice the reference nutrient intake, and that for individuals with high energy requirements this value (1.5 g/kg per d) is easily exceeded, there is a case for revising the definition of a safe upper limit.
Optimal nutrition: calcium, magnesium and phosphorus
Authors: Cashman Kevin D. , Flynn Albert
Published: February 2011

In the past, a major challenge for nutrition research was in defining indicators of nutritional adequacy. More recently, the research base related to the role of nutrition in chronic disease has expanded sufficiently to permit moving beyond deficiency indicators to other indicators with broader functional significance. Thus, nutrition research is faced with the new challenge of defining ‘optimal nutrition’. One definition of optimal nutrition with respect to any particular nutrient could be when a functional marker reaches an ‘optimal value’ or plateau beyond which it is no longer affected by intake or stores of the nutrient. A functional marker of nutrient status could be defined as a physiological or biochemical factor which (1) is related to function or effect of the nutrient in target tissue(s) and (2) is affected by dietary intake or stores of the nutrient (which may include markers of disease risk). Examples of such indicators or markers are those related to risk of chronic diseases such as osteoporosis, CHD, or hypertension. The present review focuses on the concept of optimal nutrition with respect to three nutrients, Ca, Mg and P. However, for P and Mg there are as yet no functional indicators which respond to dietary intake, and in such cases nutrient requirements are established using more traditional approaches, e.g. balance data. For Ca, there has been interest in using maximal Ca retention, which is based on balance data, bone mass measurements and biomarkers of bone turnover as useful functional indicators of the adequacy of Ca intake.
Present and future studies on lipogenesis in animals and human subjects
Authors: Vernon Richard G. , Barber Michael C. , Travers Maureen T.
Published: February 2011

Lipogenesis occurs in all vertebrate species and has a critical role in energy balance, providing a means whereby excess energy can be stored as a fat. The metabolic pathways involved and their tissue distribution in different species, including man, are well known. The responses of lipogenesis to diet and to physiological and pathological states have been the subject of many studies. At a molecular level the major rate-controlling enzymes have been identified and their acute, and to a lesser extent chronic, control by hormones have been investigated extensively. However, there is no reason to suppose that all factors regarding lipogenesis have been identified (e.g. the recent discovery of acylation-stimulating protein). Little is known about the movement of newly-synthesized triacylglycerols in cells, either for secretion or storage. The production of leptin and tumour necrosis factor α by adipocytes provides a novel means of feedback control of triacylglycerol production, leptin by decreasing appetite and tumour necrosis factor α by inducing insulin resistance. The synthesis of these peptides appears to vary with the amount of triacylglycerol in adipocytes, but the molecular basis of this process is unknown. Elucidation of the signalling systems involved in the acute and chronic regulation of lipogenesis is also important, both with respect to some homeorhetic adaptations and also in some pathological conditions (e.g. non-insulin-dependent diabetes). Finally, molecular biology is revealing unexpected complexities, such as multiple promoters and different isoforms of enzymes (e.g. acetyl-CoA carboxylase; EC 6.4.1.2) exhibiting tissue specificity. Molecular biology, through transgenesis, also offers novel and powerful means of manipulating lipogenesis.