bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultra-small-angle neutron scattering from dense micrometre-sized colloidal systems: data evaluation and comparison with static light scattering
Authors: Innerlohinger Josef , Villa Mario , Baron Matthias , Glatter Otto
Published: March 2006

Ultra-small-angle neutron scattering (USANS) probes the sameqregime as static light scattering (LS), making USANS an additional tool for the study of structures between 100 nm and 10 µm. Dense oil-in-water emulsions, which have already been characterized intensively by light scattering, are investigated in this study as a model system using USANS. The two basic problems of such scattering studies are the following: on the one hand, one has to use different scattering theories for USANS and LS, and on the other hand, in both cases one has to deal not only with particle interactions but also with multiple-scattering effects. For neutron scattering it is always possible to use the simpler Rayleigh–Debye–Gans (RDG) theory instead of the Lorenz–Mie theory, which generally describes light scattering from micrometre-sized globular objects. The samples have different contrasts in neutron and light scattering, such that only low-contrast (close to index match) LS data can be interpreted by the RDG theory. The data evaluation is performed by means of the generalized indirect Fourier transformation (GIFT) method, which enables the simultaneous calculation of the form and structure factors. The results are discussed and compared with those from light scattering experiments, taking into account the advantages of both methods. The effect of multiple scattering and its influence on data evaluation is also examined. Data evaluation by applying the GIFT method works well for both neutron and light scattering data, with results of comparable quality. The advantages of light scattering are the fast data acquisition and the large number of data points. USANS, on the other hand, covers a widerqrange and the problem of multiple scattering is not as severe as for light scattering, but still must not be neglected.
Activation of a Cu/ZnO catalyst for methanol synthesis
Authors: Andreasen Jens Wenzel , Rasmussen Frank Berg , Helveg Stig , Molenbroek Alfons , Ståhl Kenny , Nielsen Martin Meedom , Feidenhans'l Robert
Published: March 2006

The structural changes during activation by temperature-programmed reduction of a Cu/ZnO catalyst for methanol synthesis have been studied by severalin situtechniques. The catalyst is prepared by coprecipitation and contains 4.76 wt% Cu, which forms a substitutional solid solution with ZnO as determined by resonant X-ray diffraction.In situresonant X-ray diffraction reveals that the Cu atoms are extracted from the solid solution by the reduction procedure, forming metallic Cu crystallites. Cu is redispersed in bulk or surface Zn lattice sites upon oxidation by heating in air. The results are confirmed byin situelectron energy loss spectroscopy andin situresonant small-angle X-ray scattering. The average Cu particle size in the reduced catalyst as determined by the latter technique is ∼27 Å. The observed structural behaviour may have important implications for catalyst design and operation. More than one type of Cu particle with different origins may be present in Cu/ZnO catalysts with Cu loadings higher than the solubility limit of Cu in ZnO: particles formed by extraction of Cu from the (Zn,Cu)O solid solution and particles formed by reduction of CuO primary particles. The former type is highly dispersed and in intimate contact with the surface of the host ZnO particles. The possibility of re-forming the (Zn,Cu)O solid solution by oxidation may provide a means of redispersing Cu in a deactivated catalyst.
Hard X-ray surface modes of a periodic multilayer
Authors: Prudnikov I. R.
Published: March 2006

A specific periodic multilayer has been suggested that is intended for the generation of hard X-ray surface modes of the multilayer. The condition of the effective excitation of these modes is analysed. Possible experimental applications of the X-ray surface modes are briefly discussed.
Analysis of scattering from polydisperse structure using Mellin convolution
Authors: Stribeck Norbert
Published: March 2006

This study extends a mathematical concept for the description of heterogeneity and polydispersity in the structure of materials to multiple dimensions. In one dimension, the description of heterogeneity by means of Mellin convolution is well known. In several papers by the author, the method has been applied to the analysis of data from materials with one-dimensional structure (layer stacks or fibrils along their principal axis). According to this concept, heterogeneous structures built from polydisperse ensembles of structural units are advantageously described by the Mellin convolution of a representative template structure with the size distribution of the templates. Hence, the polydisperse ensemble of similar structural units is generated by superposition of dilated templates. This approach is particularly attractive considering the advantageous mathematical properties enjoyed by the Mellin convolution. Thus, average particle size, and width and skewness of the particle size distribution can be determined from scattering data without the need to model the size distributions themselves. The present theoretical treatment demonstrates that the concept is generally extensible to dilation in multiple dimensions. Moreover, in an analogous manner, a representative cluster of correlated particles (e.g.layer stacks or microfibrils) can be considered as a template on a higher level. Polydispersity of such clusters is, again, described by subjecting the template structure to the generalized Mellin convolution. The proposed theory leads to a simple pathway for the quantitative determination of polydispersity and heterogeneity parameters. Consistency with the established theoretical approach of polydispersity in scattering theory is demonstrated. The method is applied to the best advantage in the field of soft condensed matter when anisotropic nanostructured materials are to be characterized by means of small-angle scattering (SAXS, USAXS, SANS).
A new apparatus for measuring mechanical properties at moderate confining pressures in a neutron beamline
Authors: Covey-Crump Stephen J. , Holloway Robert F. , Schofield Paul F. , Daymond Mark R.
Published: March 2006

A simple pressure vessel suitable for use at room temperature has been developed which allows neutron diffraction data to be collected from cylindrical samples of up to 10 mm diameter, at confining pressures of up to 160 MPa, whilst they are also being deformed in compression by the application of a uniaxially symmetric load. The vessel has been commissioned on the ENGIN-X beamline at the ISIS neutron facility (Rutherford Appleton Laboratory, Chilton, UK). The commissioning results show that neutron diffraction data of quality equivalent to that obtained using an identical experiment geometry at room pressure can be acquired using the pressure vessel with only about a factor of two increase in count times.
Structural redetermination, thermal expansion and refractive indices of KLu(WO4)2
Authors: Pujol M. C. , Mateos X. , Aznar A. , Solans X. , Suriñach S. , Massons J. , Díaz F. , Aguiló M.
Published: March 2006

The crystal structure of monoclinic KLu(WO4)2(KLuW) crystals was determined at room temperature by using single-crystal X-ray diffraction data. The unit-cell parameters werea= 10.576 (7),b= 10.214 (7),c= 7.487 (2) Å, β = 130.68 (4)°, withZ= 4, in space groupC2/c. The unit-cell parameters of KLu1−xYbx(WO4)2were determined in relation to Yb concentration. Vickers micro-indentations were used to study the microhardness of KLuW. The linear thermal expansion tensor was determined and the principal axis with maximum thermal expansion (\alpha_{33}' = 16.72 × 10−6 K−1), X_3', was located 13.51° from thecaxis. The room-temperature optical tensor was studied in the near-infrared (NIR) and visible range. The principal optical axis with maximum refractive index (ng= 2.113),Ng, was located 18.5° from thecaxis at 632.8 nm. Undoped and ytterbium-doped KLuW crystals were grown by the TSSG (top-seeded-solution growth) slow-cooling method. The crystals show {110}, {\bar{1}11}, {010} and {310} faces that basically constitue the habit of the KLuW crystals.
ATSAS2.1, a program package for small-angle scattering data analysis
Authors: Konarev Petr V. , Petoukhov Maxim V. , Volkov Vladimir V. , Svergun Dmitri I.
Published: March 2006

The program packageATSAS2.1 for small-angle X-ray and neutron scattering data analysis is presented. The programs included in the package cover the major processing and interpretation steps from primary data reduction to three-dimensional modelling. This system is primarily oriented towards the analysis of biological macromolecules, but could also be used for non-biological isotropic and partially ordered objects (nanoparticle systems, colloidal solutions, polymers in solution and bulk). Recent developments in the programs included inATSAS2.1 are highlighted. The main programs run on multiple hardware platforms, including Windows PC, Linux RedHat and Suse, DEC Alpha, SGI IRIX and Mac OSX.
Effects of cryoprotectant concentration and cooling rate on vitrification of aqueous solutions
Authors: Berejnov Viatcheslav , Husseini Naji S. , Alsaied Osama A. , Thorne Robert E.
Published: March 2006

Vitrification of aqueous cryoprotectant mixtures is essential in cryopreservation of proteins and other biological samples. Systematic measurements of critical cryoprotective agent (CPA) concentrations required for vitrification during plunge-cooling fromT= 295 K toT= 77 K in liquid nitrogen are reported. Measurements on fourteen common CPAs, including alcohols (glycerol, methanol, 2-propanol), sugars (sucrose, xylitol, dextrose, trehalose), polyethylene glycols (ethylene glycol, PEG 200, PEG 2000, PEG 20000), glycols [dimethyl sulfoxide (DMSO), 2-methyl-2,4-pentanediol (MPD)], and salt (NaCl), were performed for volumes ranging over four orders of magnitude from ∼1 nl to 20 µl, and covering the range of interest in protein crystallography. X-ray diffraction measurements on aqueous glycerol mixtures confirm that the polycrystalline-to-vitreous transition occurs within a span of less than 2%w/vin CPA concentration, and that the form of polycrystalline ice (hexagonal or cubic) depends on CPA concentration and cooling rate. For most of the studied cryoprotectants, the critical concentration decreases strongly with volume in the range from ∼5 µl to ∼0.1 µl, typically by a factor of two. By combining measurements of the critical concentrationversusvolume with cooling timeversusvolume, the function of greatest intrinsic physical interest is obtained: the critical CPA concentrationversuscooling rate during flash-cooling. These results provide a basis for more rational design of cryoprotective protocols, and should yield insight into the physics of glass formation in aqueous mixtures.
Spin-echo small-angle neutron scattering for magnetic samples
Authors: Grigoriev Sergey V. , Kraan Wicher H. , Rekveldt M. Theo , Kruglov Timofey , Bouwman Wim G.
Published: March 2006

A novel real-space scattering technique, spin-echo small-angle neutron scattering for magnetic samples, is described. Previously, this method has been exploited for non-magnetic samples only, in order to measure the nuclear density correlation function. Magnetic scattering is different from nuclear scattering as in the former a partial neutron spin-flip that affects the phase accumulation of the Larmor precession occurs just at the moment of scattering. Because of this intrinsic property of magnetic scattering, one can use a magnetic sample as a flipper in the spin-echo technique. This enables the separation of the magnetic contribution from other sources of scattering. Particular features of the technique are pointed out. Some model examples are considered. The similarity and the differences of magnetic SESANS with respect to the technique of three-dimensional neutron depolarization are discussed. The theoretical description is proven by experiments.
Co-refinement of multiple-contrast neutron/X-ray reflectivity data usingMOTOFIT
Authors: Nelson Andrew
Published: March 2006

The contrast-variation technique is employed in multiple-contrast neutron/X-ray reflectometry experiments to highlight scattering from different structural components that are present at a surface or interface. The advantage of this technique is that the structural model used to describe the interfacial scattering length density profile must apply to all the contrasts measured. A new reflectivity analysis package,MOTOFIT, which runs in theIGOR Proenvironment (http://www.wavemetrics.com), has been created to aid the simultaneous fitting (with the same structural model) of these multiple-contrast data, using an intuitive graphical user interface, which most co-refinement packages do not possess.MOTOFITuses a slab-model approach with the Abeles matrix method, and extensions for surface roughness to perform non-linear least-squares regression on the experimental reflectivity curves. Other features, such as the ability to create complicated interparameter constraints or analyse reflectivity from multilayers, simulated annealing,etc., makeMOTOFITa powerful reflectometry analysis package
HEL– a program for model building based on a phased rotation, conformation and translation function
Authors: Pavelcik Frantisek
Published: March 2006

HELis a program for creating continuous chains of polypeptides or polynucleotides from positioned fragments. Structure fragments are located by the programNUT, which performs a phased rotation, conformation and translation function. The output ofHELis a PDB file.
A new batch-processing data-reduction application for X-ray diffraction data
Authors: Davies R. J.
Published: March 2006

Modern synchrotron radiation facility beamlines offer high-brilliance beams and sensitive area detectors. Consequently, experiments such as scanning X-ray microdiffraction can generate large data sets within relatively short time periods. In these specialist fields there are currently very few automated data-treatment solutions to tackle the large data sets produced. Where there is existing software, it is either insufficiently specialized or cannot be operated in a batch-wise processing mode. As a result, a large gap exists between the rate at which X-ray diffraction data can be generated and the rate at which they can be realistically analysed. This article describes a new software application to perform batch-wise data reduction. It is designed to operate in combination with the commonly usedFit2Dprogram. Through the use of intuitive file selection, numerous processing lists and a generic operation sequence, it is capable of the batch-wise reduction of up to 60 000 diffraction patterns during each treatment session. It can perform automated intensity corrections to large data series, perform advanced background-subtraction operations and automatically organizes results. Integration limits can be set graphically on-screen, uniquely derived from existing peak positions or globally calculated from user-supplied values. The software represents a working solution to a hitherto unsolved problem.
Deregulation of cyclin D2 by juxtaposition with T‐cell receptor alpha/delta locus in t(12;14)(p13;q11)‐positive childhood T‐cell acute lymphoblastic leukemia
Authors: Karrman Kristina , Andersson Anna , Björgvinsdóttir Helga , Strömbeck Bodil , Lassen Carin , Olofsson Tor , Nguyen‐Khac Florence , Berger Roland , Bernard Olivier , Fioretos Thoas , Johansson Bertil
Published: March 2006

Abstract:  Objectives: The t(12;14)(p13;q11) – a recurrent translocation in childhood T‐cell acute lymphoblastic leukemia (T‐ALL) – has very recently been molecularly characterized in one case, which displayed overexpression of the cyclin D2 gene (CCND2). Patients and methods: We have characterized two pediatric t(12;14)‐positive T‐ALLs using fluorescence in situ hybridization (FISH), cDNA microarray, and real‐time polymerase chain reaction (PCR). Results: FISH revealed breakpoints (BPs) in the T‐cell receptor alpha/delta locus (14q11) and in the vicinity of the CCND2 gene at 12p13. To investigate the expression of genes in 12p13, cDNA microarray analysis was performed. Expression data for eight genes, including CCND2, surrounding the 12p BP were compared with those in other T‐ALLs. The t(12;14)‐positive T‐ALL displayed an increased expression of CCND2 compared to the controls, whereas the expression of the other genes was similar in all T‐ALLs. Expression of CCND2 and two additional genes (PARP11 and FGF23), close to the 12p BP, was investigated with real‐time PCR of the two t(12;14)‐positive cases and four controls. Neither PARP11 nor FGF23 displayed expression differences among the T‐ALLs, whereas CCND2 was clearly overexpressed in both t(12;14)‐positive cases as compared to the mean expression level in the controls. Conclusion: We have confirmed, in two additional cases, that the recurrent T‐ALL‐associated t(12;14) results in overexpression of cyclin D2. The t(12;14) is the first neoplasia‐associated translocation shown to result in overexpression of cyclin D2. Furthermore, it is the first example of a T‐cell neoplasm with a targeted deregulation of a member of a cyclin‐encoding gene family.
Understanding Mothers’ Engagement with Antenatal Parent Education Services: A Critical Analysis of a local Sure Start Service
Authors: Pearson Charlotte , Thurston Miranda
Published: March 2006

This article discusses the issue of engagement in antenatal parent education for women living in deprived areas. The article focuses on the findings of a local evaluation of a Sure Start parent education programme designed to improve parental engagement with antenatal services. The article discusses the re‐orientation of this service, the impact on service users and the implications for professionals. Evidence suggests that this service has been beneficial for those involved and resulted in improved levels of engagement, with 9 per cent of eligible women attending prenatal sessions prior to the introduction of the Sure Start local programme's parent education service and 34 per cent of eligible women attending after its introduction. Despite this, the service only reaches a small proportion of the eligible population. The article also discusses the issue of professional resistance from mainstream services as an unintended consequence of the introduction of the Sure Start local programme and considers the implications of this for effective delivery. Copyright © 2006 The Author(s).
‘Someone of Your Own to Love’: Experiences of Being Looked After as Influences on Teenage Pregnancy
Authors: Knight Abigail , Chase Elaine , Aggleton Peter
Published: March 2006

Previous research has shown that children and young people who are looked after are vulnerable to poor life outcomes, including early pregnancy. This paper examines how experiences of being looked after may contribute to teenage pregnancy. Using in‐depth interviews, data were collected from 63 young people recently looked after who are aged 15–24 and 78 professionals, across four research sites. The young people reported feelings of loneliness, rejection, stigma and not being able to trust others, emotions which seriously influenced their decisions about becoming parents. The findings suggest that such young people may benefit from a greater degree of emotional and practical support throughout their lives in care. Copyright © 2006 Institute of Education, University of London.
Educational Issues for Children and Young People in Families Living in Emergency Accommodation—An Irish Perspective
Authors: Keogh Anna Fiona , Halpenny Ann Marie , Gilligan Robbie
Published: March 2006

The article explores how homelessness may impact on the educational participation of children and young people in families living in emergency accommodation in Dublin. Many difficulties arise in terms of maintaining consistent schooling for children when they are part of a homeless family, including problems getting to and from school if living at a distance from their original schools, frequent changes in school and inadequate facilities and overcrowding in their temporary accommodation. Despite the many difficulties involved in maintaining children's regular school attendance, it is evident that school may represent the only stability for a child in an otherwise insecure and changing routine. Copyright © 2006 Children's Research Centre.
Personal view: the paradox of runaway competitions in gastroenterology
Authors: SONNENBERG A.
Published: March 2006

Occasionally, gastroenterologists harbour reservations about the appropriateness of various procedures and management options, yet find themselves drawn into a competition and forced by outside exigencies to provide such services. The aim of the present analysis was to describe patterns of runaway competitions and factors that influence their occurrence in gastroenterology. The interactions between two physicians or physician and patient are modelled as non‐zero‐sum games of two players.

The outcomes associated with two behavioural strategies of two players are arranged in a two‐by‐two game matrix. Many scenarios of clinical gastroenterology and social interactions among gastroenterologists are characterized by the underlying game of prisoner's dilemma, where two players can choose to co‐operate or compete with each other. Although from their joint perspective co‐operation results in a higher joint utility, the perspective of each individual favours competition.

Following the inescapable logic of their individual perspective, the players end up with a worse outcome than through co‐operation. A runaway competition ensues if the game is played repeatedly with players successively increasing their stakes. Ultimately, each player tries to outdo the opponent while heading in the wrong direction. Recognizing the hallmarks of the game of prisoner's dilemma may help gastroenterologists to avoid such competitions.
Effect of lactulose and Saccharomyces boulardii administration on the colonic urea‐nitrogen metabolism and the bifidobacteria concentration in healthy human subjects
Authors: DE PRETER V. , VANHOUTTE T. , HUYS G. , SWINGS J. , RUTGEERTS P. , VERBEKE K.
Published: March 2006

Background  Protein fermentation products, especially ammonia, are implicated in the pathogenesis of certain diseases.

Aim  To investigate the influence of lactulose and Saccharomyces boulardii cells on the composition of the intestinal microbiota and on the metabolic fate of ammonia by means of lactose‐[15N, 15N]‐ureide.

Methods  An at random, placebo‐controlled, crossover study was performed in 43 healthy volunteers to evaluate the influence of lactulose and/or S. boulardii cells either administered as a single dose or after a 4‐week intake period. Urine and faeces were collected. All samples were analysed for 15N‐content by combustion‐isotope ratio mass spectrometry. Real‐time polymerase chain reaction was applied to determine the composition of the predominant faecal microbiota.

Results  A single administration of lactulose significantly decreased urinary 15N‐excretion in a dose‐dependent way. After long‐term administration of lactulose, a significant reduction of the urinary 15N‐excretion was observed, which was accompanied with a significant increase in the faecal 15N‐output, more specifically more 15N was found in the bacterial fraction. A significant rise in the Bifidobacterium population was found after lactulose intake. No significant effects were observed after S. boulardii intake.

Conclusion  Dietary addition of lactulose can exert a bifidogenic effect accompanied by a favourable effect on the colonic NH3‐metabolism.
Altered levels of biochemical indices of bone turnover and bone‐related vitamins in patients with Crohn's disease and ulcerative colitis
Authors: GILMAN J. , SHANAHAN F. , CASHMAN K. D.
Published: March 2006

Background  The pathogenesis of inflammatory bowel disease‐associated osteopenia may be related to pathological rates of bone turnover; however, the literature shows mixed results.

Aim  To compare bone biomarkers in inflammatory bowel disease patients (Crohn's disease: n = 68, and ulcerative colitis: n = 32, separately) with age‐ and sex‐matched healthy controls.

Subjects  Patients and controls were recruited from Cork University Hospital and Cork City area, respectively.

Results  Relative to that in their respective controls, Crohn's disease (n = 47) and ulcerative colitis (n = 26) patients (i.e. excluding supplement users) had significantly (P < 0.05–0.001) higher serum undercarboxylated osteocalcin (by 27% and 63%, respectively) and bone‐specific alkaline phosphatase (by 15% and 21%, respectively) and urinary Type I collagen cross‐linked N‐telopeptides concentrations (by 87% and 112%, respectively). Relative to that in their respective controls, Crohn's disease and ulcerative colitis patients had significantly (P < 0.01) lower serum total osteocalcin (by 20% and 42%, respectively) and 25‐hydroxyvitamin D (by 37% and 42%, respectively), while serum parathyroid hormone levels were similar. In the combined patient group (n = 100), undercarboxylated osteocalcin was positively associated with bone markers.

Conclusions  Both Crohn's disease and ulcerative colitis patients have altered bone turnover relative to that in healthy controls.
Biliary lipids, cholesterol and bile synthesis: different adaptive mechanisms to dietary cholesterol in lean and obese subjects
Authors: KLASS D. M. , BÜHRMANN K. , SAUTER G. , DEL PUPPO M. , SCHEIBNER J. , FUCHS M. , STANGE E. F.
Published: March 2006

Background  Increased biliary cholesterol secretion together with elevated cholesterol synthesis may predispose obese subjects to cholesterol gallstone formation.

Aim  To investigate whether processing of dietary cholesterol is altered in obesity, we enrolled eight lean and seven obese subjects in a double‐blind crossover study.

Methods  Cholesterol consumption was 300 mg/day on low and 1300 mg/day on high cholesterol diet. After 3 weeks on either diet, hepatic bile was collected to determine biliary lipid secretion, and bile salt composition by high‐performance liquid chromatography and cholesterol saturation index was calculated. Cholesterol synthesis was measured employing mass isotopomer distribution analysis. Bile acid synthesis via neutral and acidic pathway was assessed by serum levels of 7α‐hydroxy‐4‐cholesten‐3‐one and 27‐hydroxycholesterol.

Results  Cholesterol synthesis was increased in obese compared with lean and feedback inhibited only in obese. On low cholesterol diet, cholesterol secretion was doubled in obese but bile acid composition and synthesis was similar between the two groups. After high cholesterol diet, cholesterol saturation index and bile secretion were unchanged. In contrast to obese, lean increased bile acid synthesis only via the acidic pathway.

Conclusions  Dietary cholesterol appears to preferentially induce bile acid synthesis via the acidic pathway in lean, whereas cholesterol synthesis was inhibited in obese. Thus, stable cholesterol saturation index may be achieved by different mechanisms.
Personal view: adequate relief as a primary endpoint in irritable bowel syndrome
Authors: MANGEL A. W.
Published: March 2006

The success of a clinical trial is judged by achieving statistical and clinical significance on the primary endpoint. This is particularly relevant in those trials that are initiated to achieve regulatory approval of a new therapeutic agent. Selection of an endpoint for which statistical significance will be too difficult to achieve can result in clinical trial data that fails to meet regulatory requirements for product approval.

Over the past decade, significant progress has been made in development and refinement of the study design for evaluating new therapeutic agents targeted for the treatment of irritable bowel syndrome. One aspect of trial design that has been advanced is recognition of the endpoint of ‘Adequate Relief.’ Adequate relief has been used as a primary endpoint in treatment trials with alosetron, cilansetron and dextofisopam. With each of these agents, statistically significant benefit was seen when compared to placebo.

As an endpoint, adequate relief is responsive, reproducible and moves in the same direction as other meaningful measures, and, therefore, displays properties of a validated endpoint. Adequate relief should be considered an acceptable primary endpoint by regulatory agencies for use in clinical trials of novel therapeutic agents for irritable bowel syndrome.
Unawareness of gastrointestinal symptomatology in adult coeliac patients with unexplained iron‐deficiency anaemia presentation
Authors: BACCINI F. , ALOE SPIRITI M. A. , VANNELLA L. , MONARCA B. , DELLE FAVE G. , ANNIBALE B.
Published: March 2006

Background  Most adults with coeliac disease have a subclinical form of the disease and iron‐deficiency anaemia may be the sole presenting symptom.

Aim  To evaluate demographic, clinical and biochemical characteristics of adult coeliac disease patients presenting with iron‐deficiency anaemia.

Patients  A total of 108 iron‐deficiency anaemia patients in whom coeliac disease has been diagnosed were studied. As a control group 108 non‐coeliac iron‐deficiency anaemia patients, comparable for sex and age, were studied.

Results  Of the 108 coeliac disease patients, 95 (88%) were female (mean age 34 years, range 19–72) and 13 (12%) were male (mean age 33 years, range 15–65). The median duration of iron‐deficiency anaemia before diagnosis was 66 months in coeliac disease patients and 14 months in the iron‐deficiency anaemia control group (P = 0.0001). The occurrence of at least one gastrointestinal symptom, not spontaneously reported, was observed in 92 (85%) patients with coeliac disease and in 67 (62%) patients in the control group (P = 0.001). The concomitant presence of diarrhoea, abdominal pain and abdominal bloating was detected in 14% patients with coeliac disease with respect to 3% in the control group (P = 0.005).

Conclusions  The vast majority of coeliac disease patients with iron‐deficiency anaemia presentation were unaware of the gastrointestinal symptoms and this relationship is useful for diet compliance.
Gastroenterologists utilize the referral for EGD to enhance colon cancer screening more effectively than primary care physicians
Authors: MENEES S. B. , SCHEIMAN J. , CARLOS R. , MULDER A. , FENDRICK A. M.
Published: March 2006

Background  Colorectal cancer screening rates among patients with upper gastrointestinal symptoms undergoing oesophagogastroduodenoscopy have not been previously established. We hypothesize that gastroenterologists seize this opportunity more frequently than primary care providers.

Aims  To assess colorectal cancer screening rates at the time of direct access oesophagogastroduodenoscopy and gastrointestinal clinic evaluation for upper gastrointestinal symptoms. To compare rates in the 6 months following the oesophagogastroduodenoscopy in both cohorts of patients.

Methods  Retrospective review. primary care physician group: direct access oesophagogastroduodenoscopy (n = 247) vs. gastrointestinal group (n = 278). Multivariable regression analysis utilized to assess predictors of screening outcome.

Results  Colorectal cancer screening at the time of referral was 54%. Among the 243 unscreened patients, an additional 29% in the primary care physician group vs. 59% in the gastrointestinal group completed colorectal cancer screening in 6 months of follow‐up. Nearly 60% patients evaluated in gastrointestinal clinic for upper symptoms had documented discussion, and 99% of those patients underwent colonoscopy (P < 0.001). Gastrointestinal consultation increased the probability of colorectal cancer screening completion eightfold (95% CI 3.69–18.96).

Conclusions  At the time of evaluation for upper symptoms, half of patients were not current with colorectal cancer screening recommendations. Referrals for the direct access oesophagogastroduodenoscopy and, more importantly, the gastroenterology consult represent key opportunities for colorectal cancer screening education and improved compliance.
Predictors of the placebo response in functional dyspepsia
Authors: TALLEY N. J. , LOCKE G. R. , LAHR B. D. , ZINSMEISTER A. R. , COHARD‐RADICE M. , D'ELIA T. V. , TACK J. , EARNEST D. L.
Published: March 2006

Background  Trials in functional dyspepsia report placebo response rates of 30% to 40%.

Aim  We aimed to identify predictors of the placebo response.

Methods  Patients from primary, secondary and tertiary practices with functional dyspepsia defined by Rome II criteria were enrolled into one of four clinical trials; 220 patients were randomized to receive placebo. Scintigraphic assessment of gastric emptying at baseline was repeated at the end of the treatment in those with delayed emptying. After a 2 week run‐in period, patients were followed for 8 weeks on placebo. Response was assessed on a weekly basis and a responder was defined as satisfactory relief of meal‐related symptoms on at least 50% of weeks.

Results  The mean age was 44 years (range 18–82) and 74% were female; 76 (35%) were placebo responders. The predominant symptom was an unstable measure over the trial. Independent predictors of a lower placebo response were lower body mass index and a more consistent predominant symptom pattern (both P < 0.05). No association was seen with age, gender, centre type, baseline symptom score, baseline or change in gastric emptying, or baseline quality of life.

Conclusion  In functional dyspepsia, a consistent predominant symptom pattern and lower body mass index may be associated with a lower placebo response rate.
The effects of esomeprazole combined with aspirin or rofecoxib on prostaglandin E2 production in patients with Barrett's oesophagus
Authors: TRIADAFILOPOULOS G. , KAUR B. , SOOD S. , TRAXLER B. , LEVINE D. , WESTON A.
Published: March 2006

Background  Reducing mucosal cyclo‐oxygenase‐2 and prostaglandin E2 production and suppressing intraoesophageal acid may be effective chemopreventive strategies in patients with Barrett's oesophagus.

Aim  To compare the effects of aspirin and rofecoxib when administered with esomeprazole on prostaglandin E2 production, cyclo‐oxygenase‐2 expression and proliferating cell nuclear antigen expression in patients with Barrett's oesophagus.

Methods  This exploratory, multicentre, randomized, open‐label, four‐way crossover study in 45 patients with Barrett's oesophagus evaluated prostaglandin E2 content, proliferating cell nuclear antigen expression, and cyclo‐oxygenase‐2 expression after 10 days of sequential treatments with: esomeprazole 40 mg twice daily plus aspirin 325 mg once daily (E40 b.d. + A325); E40 b.d. plus rofecoxib 25 mg once daily (E40 b.d. + R25); E40 b.d.; and rofecoxib 25 mg once daily (R25).

Results  Prostaglandin E2 content reduction in Barrett's oesophagus tissue was significantly greater with E40 b.d. + A325 compared with E40 b.d. + R25, E40 b.d. or R25 (P < 0.05). All treatments containing E40 b.d. significantly decreased proliferating cell nuclear antigen expression from baseline (P < 0.05). None of the treatments significantly reduced cyclo‐oxygenase‐2 expression.

Conclusions  The combined treatment of esomeprazole 40 mg b.d. and aspirin 325 mg significantly decreased mucosal prostaglandin E2 content and all treatments containing esomeprazole significantly reduced proliferating cell nuclear antigen expression in patients with Barrett's oesophagus.
Dose–response evaluation of the antisecretory effect of continuous infusion intravenous lansoprazole regimens over 48 h
Authors: HOWDEN C. W. , METZ D. C. , HUNT B. , VAKILY M. , KUKULKA M. , AMER F. , SAMRA N.
Published: March 2006

Background  Attainment of intragastric pH < 6.0 may require high‐dose continuously infused proton pump therapy.

Aim  To assess the pharmacokinetic and pharmacodynamic dose–responses of continuous infusion regimens of lansoprazole.

Methods  Healthy adult subjects were assigned to lansoprazole 60‐mg intravenous bolus, followed by 6‐mg/h continuous infusion; a 90‐mg intravenous bolus followed by 6‐, 7.5‐, or 9‐mg/h continuous infusion; or placebo.

Results  Mean intragastric pH values for lansoprazole regimens ranged from 4.8 to 5.2 (0–24 h), 5.5 to 6.0 (>24 to 48 h) and 5.2 to 5.6 (0–48 h). Within these three intervals, the percentages of time intragastric pH exceeded 4, 5 and 6 ranged from 65% to 96%, 54% to 88% and 30% to 61% respectively. Pharmacokinetic parameters were dose‐independent with steady‐state plasma concentrations achieved within 6–12 h postdose and maintained over 48 h. The mean systemic clearance of lansoprazole was lower in CYP2C19 heterozygous metabolizers than in homozygous extensive metabolizers (9.2 vs. 16.5 L/h), with substantial variability resulting in overlapping ranges of clearance values for both subpopulations. All lansoprazole regimens were well‐tolerated.

Conclusions  Lansoprazole administered as a 60‐mg intravenous bolus followed by 6‐mg/h continuous infusion produced intragastric pH effects comparable with those of higher dosage regimens.
Lansoprazole regimens that sustain intragastric pH >6.0: an evaluation of intermittent oral and continuous intravenous infusion dosages
Authors: METZ D. C. , AMER F. , HUNT B. , VAKILY M. , KUKULKA M. J. , SAMRA N.
Published: March 2006

Background  Orally and intravenously administered proton pump inhibitors have been shown to reduce rebleeding rates, surgery and transfusion requirement.

Aim  To compare lansoprazole intravenous and orally disintegrating tablet (Prevacid SoluTab) regimens with a pantoprazole intravenously administered regimen in sustaining intragastric pH >6.0.

Methods  Two similarly designed three‐way, randomized crossover studies each enrolled 36 Helicobacter pylori‐negative healthy volunteers. Study 1 regimens included intravenously administered bolus followed by 24‐h continuous infusion (lansoprazole 90 mg, 6 mg/h; lansoprazole 120 mg, 6 mg/h; pantoprazole 80 mg, 8 mg/h). Study 2 regimens included intravenous bolus followed by lansoprazole orally disintegrating tablet or intravenous continuous infusion for 24 h (lansoprazole 90 mg, lansoprazole orally disintegrating tablet 60 mg every 6 h; lansoprazole 120 mg, 9 mg/h; pantoprazole 80 mg, 8 mg/h). Percentage of time pH >6.0 was assessed with 24‐h intragastric pH monitoring.

Results  All regimens produced comparable gastric acid suppression. In both studies, regimens superior to pantoprazole included lansoprazole 90 mg, 6‐mg/h; lansoprazole 90 mg, lansoprazole orally disintegrating tablet 60 mg q.d.s. and lansoprazole 120 mg, 9 mg/h (P ≤ 0.013). The lansoprazole 120‐mg, 6‐mg/h regimen (P = 0.082) was not superior to pantoprazole in percentage of time intragastric pH >6.0. Mild reaction at the intravenous injection site was the most frequently reported adverse event.

Conclusions  The intravenous bolus and continuously infused lansoprazole or intravenous bolus and intermittent lansoprazole orally disintegrating tablet regimens are as effective as intravenous pantoprazole in sustaining intragastric pH >6.0.
Increased use of selective serotonin reuptake inhibitors in patients admitted with gastrointestinal haemorrhage: a multicentre retrospective analysis
Authors: WESSINGER S. , KAPLAN M. , CHOI L. , WILLIAMS M. , LAU C. , SHARP L. , CROWELL M. D. , KESHAVARZIAN A. , JONES M. P.
Published: March 2006

Background Selective serotonin reuptake inhibitors (SSRIs) can adversely affect platelet function and impair haemostasis. Various bleeding complications have been reported in persons taking SSRIs including an increased risk of gastrointestinal haemorrhage (GIH).

Aim To evaluate SSRI use in patients hospitalized with GIH compared with controls.

Methods A retrospective, multicentre case–control study determined use of SSRIs, non‐steroidal anti‐inflammatory drugs (NSAIDs), aspirin, clopidogrel, coumadin and enoxaparin in patients admitted with GIH and age‐ and sex‐matched controls. Exclusion criteria included liver disease, portal hypertension or bleeding diathesis.

Results A total of 579 cases were matched with 1000 controls. SSRI use was 19.2% in cases and 13.6% in controls [OR (95% CI) = 1.5 (1.2–2.0); P = 0.003]. NSAIDs were used by 7.3% of cases and 3.8% of controls [OR = 2.0 (1.3–3.1); P = 0.003]. SSRI use was more strongly associated with lower [1.8 (1.2–2.8)] rather than upper [1.3 (0.83–1.9)] GIH. Significant interactions existed for SSRI use with NSAIDs and aspirin.

Conclusions Patients admitted with GIH gastrointestinal bleeding were more likely to be taking SSRIs than controls. This association exists for lower as well as upper GIH. Physicians should be aware of this risk particularly in patients already using medications that increase GIH risk.
Comparison of the efficacy and safety of Eudragit‐L‐coated mesalazine tablets with ethylcellulose‐coated mesalazine tablets in patients with mild to moderately active ulcerative colitis
Authors: GIBSON P. R. , FIXA B. , PEKÁRKOVÁ B. , BÁTOVSKÝ M. , RADFORD‐SMITH G. , TIBITANZL J. , GABALEC L. , FLORIN T. H. J. , GREINWALD R.
Published: March 2006

Background  There are no comparative studies of coated mesalazine.

Aim  To compare the efficacy and tolerability of Eudragit‐L‐ and ethylcellulose‐coated mesalazine tablets in patients with mild to moderately active ulcerative colitis.

Methods  A double‐blind, double‐dummy, randomized parallel group trial was performed across 18 centres in Australia, and 20 in Eastern Europe. Patients were treated with 3 g mesalazine for 8 weeks with the primary efficacy end point being clinical remission.

Results  Of 215 patients, 69% achieved clinical remission in both treatment groups (P < 0.001; chi‐square test) with no differences in frequency of adverse events. In the Australian cohort (n = 63), the Eudragit‐L group had a higher remission rate (73% vs. 36%) and responded 13 days faster, compared with those in the European group (67% vs. 84%, and 2 days respectively). No clear reasons for differences in treatment responses were identified.

Conclusions  Eudragit‐L and ethylcellulose‐coated mesalazine tablets are well tolerated and equally effective in achieving remission in mild‐moderately active ulcerative colitis over 8 weeks.
Macro‐scale bird species richness patterns of the East Asian mainland and islands: energy, area and isolation
Authors: Ding Tzung‐Su , Yuan Hsiao‐Wei , Geng Shu , Koh Chao‐Nien , Lee Pei‐Fen
Published: March 2006

Aim  To create a map of bird species richness (BSR) in East Asia and to examine the effect of area, isolation, primary productivity, topographic heterogeneity, and human population density on BSR.

Location  East Asia (from 70° E to 180° E longitude), including the eastern half of the Palaearctic Region, the entire Oriental Region, and the entire Wallacea Subregion.

Methods  The breeding ranges of 2406 terrestrial bird species were mapped and overlaid to create a species richness map. The BSR map was transformed into a 100 × 100 km quadrat system, and BSR was analysed in relation to land area, average normalized difference vegetation index (NDVI), elevation range, and average population density.

Results  In general, BSR declined from the Tropics to the Arctic. In mainland East Asia, however, BSR was highest around the Tropic of Cancer, and fluctuated between 30° and 50° N. Islands had lower BSR than adjacent mainland areas. The NDVI was strongly positively correlated with BSR in mainland areas and on islands. For mainland areas, NDVI explained 65% of the BSR variation, and topographic heterogeneity explained an additional 6% in ordinary least‐squares regression. On islands, NDVI explained 66% of BSR variation, island area explained 13%, and distance to mainland accounted for 1%.

Main conclusions  In East Asia, we suggest that primary productivity is the key factor underpinning patterns of BSR. Primary productivity sets the upper limits of the capacity of habitats to support bird species. In isolated areas such as islands and peninsulas, however, BSR might not reach the richness limits set by primary productivity because the degree of isolation and area size also can affect species richness. Other factors, such as spatial heterogeneity, biotic interactions, and perturbations, may also affect species richness. However, their effects are secondary and are not as strong as primary productivity, isolation, and area size.
Administration of Kisspeptin‐54 into Discrete Regions of the Hypothalamus Potently Increases Plasma Luteinising Hormone and Testosterone in Male Adult Rats
Authors: Patterson M. , Murphy K. G. , Thompson E. L. , Patel S. , Ghatei M. A. , Bloom S. R.
Published: March 2006

Kisspeptin‐54 is the peptide product of the KiSS‐1 gene and an endogenous agonist of the GPR54 receptor. KiSS‐1 was initially discovered as a metastasis suppressor gene, but recent studies demonstrate that the kisspeptin/GPR54 system is a key regulator of the reproductive system. Disrupted GPR54 signalling causes hypogonadotrophic hypogonadism in rodents and man. Intracerebroventricular or peripheral administration of kisspeptin potently stimulates the hypothalamic‐pituitary‐gonadal (HPG) axis via the hypothalamic gonadotrophin‐releasing hormone system. We have investigated the effect of injection of kisspeptin‐54 into discrete hypothalamic regions on the HPG axis. To construct a dose–response curve for the effects of intrahypothalamic kisspeptin administration, adult male Wistar rats were cannulated into the medial preoptic area (MPOA) at the level of the organum vasculosum laminae terminalis (OVLT). Kisspeptin‐54 was injected into the MPOA at doses of 0.01, 0.1, 1, 10 and 100 pmol. At 60 min following injection of 1, 10 or 100 pmol kisspeptin‐54, plasma luteinising hormone (LH) and total testosterone levels were significantly increased. Adult male Wistar rats were then cannulated into the rostral preoptic area at the level of the OVLT (RPOA), the MPOA, the paraventricular (PVN), dorsomedial (DMN) and arcuate hypothalamic nuclei, and the lateral hypothalamic area. A dose of 1 pmol kisspeptin‐54 was administered into all areas. The circulating levels of LH and total testosterone were significantly increased 60 min postinjection of kisspeptin‐54 into the RPOA, MPOA, PVN and arcuate nucleus. Our results suggest that kisspeptin may mediate its effects on the HPG axis via these regions of the hypothalamus.
RNase Z in Escherichia coli plays a significant role in mRNA decay
Authors: Perwez Tariq , Kushner Sidney R.
Published: March 2006

Genetic and biochemical analysis of RNase Z in eukaryotes, such as Arabadopsis thaliana, and prokaryotes like Bacillus subtilis have demonstrated that this endoribonuclease is essential for the maturation of tRNA precursors that do not contain a chromosomally encoded CCA determinant. As all Escherichia coli tRNA transcripts have chromosomally encoded CCA determinants, the function of its putative RNase Z homologue, the product of the elaC gene, is not clear. Here we demonstrate that the E. coli ElaC protein (RNase Z) endonucleolytically processes B. subtilis tRNA precursors lacking a CCA determinant both in vivo and in vitro. More importantly, E. coli RNase Z plays a significant role in mRNA decay, a previously unidentified activity for the enzyme. The purified RNase Z protein cleaves the rpsT mRNA at locations distinct from those obtained with RNase E. As expected, under physiological conditions E. coli and B. subtilis tRNA precursors containing a CCA determinant are not substrates. These results suggest a potentially important new role for the RNase Z family of proteins in RNA metabolism, particularly in organisms lacking RNase E.