bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure and mesoscale plastic deformation and fracture patterns of materials coated by electron‐beam deposition
Authors: PANIN V. E. , BELYUK S. I. , DURAKOV V. G. , PANIN S. V. , GALCHENKO N. K. , SAMARTSEV V. P.
Published: December 2004

Electron‐beam deposition (EBD) is an advanced technique intended for the formation of protective coatings that exhibit high strength and wear, and fatigue resistance. The investigation of the structure of coated materials and the development of mesoscale plastic deformation shows that these properties depend heavily on EBD modes. It is proposed that the latter can be optimized by: (i) choosing the electron‐beam parameters that ensure a uniform structure of the coating, appropriate width and proper structure of the transient zone, (ii) the trial‐and‐error method of selecting such deposited powder composition that ensure high strength properties, and (iii) mechanical test aimed at distinguishing the coatings whose performance has been advantageously increased by EBD.
Stress and fracture analysis in periodic contact problem for coated bodies
Authors: GORYACHEVA I. G. , TORSKAYA E. V.
Published: December 2004

The periodic contact problem for the system of dies and two‐layered elastic foundation is considered. The imperfect adhesion between the layer and the substrate is taken into account by the boundary conditions at the interface. The solution of the problem is based on Hankel transform and the methods of localisation and superposition. The results are used to evaluate internal stresses in coated bodies which are in contact with rough surface and to analyse the influence of mechanical and geometrical characteristics of the coatings and the roughness parameters on the maximum stress value and its location, and on the types of coating fracture.
Strength estimation of ceramic–metal joints with various interlayer thickness
Authors: TAKAHASHI M. , OKABE N. , ZHU X. , KAGAWA K.
Published: December 2004

ABSTRACT Residual stresses generated by the mismatch of thermal expansion coefficients of ceramics and metals affect the strength of ceramic–metal joints. An interlayer metal can be inserted between the ceramic and metal in order to relax this stress. An analysis was carried out of the residual stresses produced during joint‐cooling and in 4‐point bending tests. The effects of interlayer thickness on ceramic–metal joint strength were then studied by considering a superimposed stress distribution of the residual stress and the bending stress. Finally, joint strength was estimated from fracture mechanics and strength probability analysis by considering the residual stress distribution, defect size and position of pre‐existing defects in the ceramic parts. As a result of this study, we suggest an optimum material selection and interlayer thickness for ceramic–metal joint structures. This approach is generally suitable for the design of electrical and mechanical structures.
Fatigue crack propagation of through cracks in thin sheets under combined traction and bending stresses
Authors: LANCIOTTI A. , POLESE C.
Published: December 2004

ABSTRACT Fatigue crack propagation tests of through cracks in 3 mm thick aluminium alloy 6013‐T6 plates, under combined membrane and bending stresses were carried out. Five different values for the ratio of bending to membrane stresses, SB, were examined: 0, 0.55, 1.25, 1.8 and 2.23. Firstly, the results were elaborated by taking into account only the membrane stress and the front dimension of the crack for the evaluation of the stress intensity factor range. The results relevant to the lower SB values, evaluated in this mode, show good agreement with the results obtained when only the membrane stress was applied, while the results obtained at the higher SB values exhibit a remarkable increase in the crack propagation rate. The results were successively evaluated on the basis of tabular stress intensity factor solutions available in the literature; the agreement between the predicted and the experimental data occurs when mean values of stress intensity factor, rather than local values, were used at the back face of the plate, i.e., the face where the bending produces a compressive stress, to counteract the high gradient of stress intensity factor present in this area.
The effects of macrolocalization of deformation in Al‐based composites with Al2O3 inclusions
Authors: DERYUGIN YE. YE. , PANIN V. E. , SCHMAUDER S. , SOPPA E.
Published: December 2004

Using a television optical TOMSC system, regular features of localization of macroplastic deformation are studied in composite aluminum‐based materials with hard inclusions of Al2O3 under tension. Before investigation, the specimens are subjected to cold rolling, tempering for 30 min at 500 °C with subsequent cooling in air, and annealing at 550 °C during 2 h with subsequent cooling in furnace. It is shown that the tempered and annealed alloys exhibit mobile centers of active macrolocalization long before the formation of a stationary neck preceding material fracture. Physical mesomechanics, relying on the concepts of the leading role of different‐scale stress concentrators that relax and develop in a loaded heterogeneous material, is capable of providing a qualitative description of macrolocalization development.
Crack growth induced delamination on steel members reinforced by prestressed composite patch
Authors: COLOMBI P. , BASSETTI A. , NUSSBAUMER A.
Published: December 2004

ABSTRACT Prestressed composite patch bonded on cracked steel section is a promising technique to reinforce cracked details or to prevent fatigue cracking on steel structural elements. It introduces compressive stresses that produce a crack closure effect. Moreover, it modifies the crack geometry by bridging the crack faces and so reduces the stress intensity range at the crack tip. Fatigue tests were performed on notched steel plate reinforced by CFRP strips as a step toward the validation of crack patching for fatigue life extension of riveted steel bridges. A crack growth induced debonded region in the adhesive‐plate interface was observed using an optical technique. Moreover, the size of the debonded region significantly influences the efficiency of the crack repair. Debond crack total strain energy release rate is computed by the modified virtual crack closure technique (MVCCT). A parametric analysis is performed to investigate the influence of some design parameters such as the composite patch Young's modulus, the adhesive thickness and the pretension level on the adhesive‐plate interface debond.
Crushing behaviour of the energy absorbing ‘tensor skin’ panels
Authors: LABEAS G. , KERMANIDIS T. H.
Published: December 2004

ABSTRACT Research results concerning the simulation of the crushing behaviour of composite systems with energy absorption characteristics are presented in the present work. The study is focused on the ‘tensor skin’ concept, an energy absorbing composite system that was originally developed to improve the crashworthiness of helicopters under water impact and which is promising for utilization in the construction of the lower part of composite fuselage aircraft. The ‘tensor skin’ concept comprises a folded or corrugated composite construction, which upon loading unfolds by forming ‘plastic hinges’, leading to an increase in the load bearing capability of the structure. The numerical modelling issues and the critical aspects of the simulation are discussed. Verification of the numerical simulation procedure is performed by experimental work. The experimental results utilized to assess and validate the numerical procedure were derived within the European Research Project ‘Design for Crash Survivability – CRASURV’ (BRITE – Aeronautics Area). The results of the simulations are generally in good agreement with experimental data.
Global synthesis of leaf area index observations: implications for ecological and remote sensing studies
Authors: Asner Gregory P. , Scurlock Jonathan M. O. , A. Hicke Jeffrey
Published: December 2004

Aim We present the first global synthesis of plant canopy leaf area index (LAI) measurements from more than 1000 published estimates representing ∼400 unique field sites. LAI is a key variable for regional and global models of biosphere‐atmosphere exchanges of energy, carbon dioxide, water vapour, and other materials.

Location The location is global, geographically distributed.

Results Biomes with LAI values well represented in the literature included croplands, forests and plantations. Biomes not well represented were deserts, shrublands, tundra and wetlands. Nearly 40% of the records in the database were published in the past 10 years (1991–2000), with a further 20% collected between 1981 and 1990. Mean (± SD) LAI, distributed between 15 biome classes, ranged from 1.3 ± 0.9 for deserts to 8.7 ± 4.3 for tree plantations, with temperate evergreen forests (needleleaf and broadleaf) displaying the highest average LAI (5.1–6.7) among the natural terrestrial vegetation classes. Following a statistical outlier analysis, the global mean (± SD) LAI decreased from 5.2 (4.1) to 4.5 (2.5), with a maximum LAI of 18. Biomes with the highest LAI values were plantations > temperate evergreen forests > wetlands. Those with the lowest LAI values were deserts < grasslands < tundra. Mean LAI values for all biomes did not differ statistically by the methodology employed. Direct and indirect measurement approaches produced similar LAI results. Mean LAI values for all biomes combined decreased significantly in the 1990s, a period of substantially more studies and improved methodologies.

Main conclusions Applications of the LAI database span a wide range of ecological, biogeochemical, physical, and climate research areas. The data provide input to terrestrial ecosystem and land‐surface models, for evaluation of global remote sensing products, for comparisons to field studies, and other applications. Example uses of the database for global plant productivity, fractional energy absorption, and remote sensing studies are highlighted.
Policy analysis for tropical marine reserves: challenges and directions
Authors: Rudd Murray A , Tupper Mark H , Folmer Henk , Van Kooten G C
Published: December 2004

Marine reserves are considered to be a central tool for marine ecosystem‐based management in tropical inshore fisheries. The arguments supporting marine reserves are often based on both the nonmarket values of ecological amenities marine reserves provide and the pragmatic cost‐saving advantages relating to reserve monitoring and enforcement. Marine reserves are, however, only one of a suite of possible policy options that might be used to achieve conservation and fisheries management objectives, and have rarely been the focus of rigorous policy analyses that consider a full range of economic costs and benefits, including the transaction costs of management. If credible analyses are not undertaken, there is a danger that current enthusiasm for marine reserves may wane as economic performance fails to meet presumed potential. Fully accounting for the value of ecological services flowing from marine reserves requires consideration of increased size and abundance of focal species within reserve boundaries, emigration of target species from reserves to adjacent fishing grounds, changes in ecological resilience, and behavioural responses of fishers to spatially explicit closures. Expanding policy assessments beyond standard cost–benefit analysis (CBA) also requires considering the impact of social capital on the costs of managing fisheries. In the short term, the amount of social capital that communities possess and the capacity of the state to support the rights of individuals and communities will affect the relative efficiency of marine reserves. Reserves may be the most efficient policy option when both community and state capacity is high, but may not be when one and/or the other is weak. In the longer term, the level of social capital that a society possesses and the level of uncertainty in ecological and social systems will also impact the appropriate level of devolution or decentralization of fisheries governance. Determining the proper balance of the state and the community in tropical fisheries governance will require broad comparative studies of marine reserves and alternative policy tools.
Developing robust frequentist and Bayesian fish stock assessment methods
Authors: Chen Yong , Jiao Yan , Chen Liqiao
Published: December 2004

Errors in fitting models to data are usually assumed to follow a normal (or log normal) distribution in fisheries. This assumption is usually used in formulating likelihood functions often required in frequentist and Bayesian stock assessment modelling. Fisheries data are commonly subject to atypical errors, resulting in outliers in stock assessment modelling. Because most stock assessment models are nonlinear and contain multiple variables, it is difficult, if not impossible, to identify outliers by plotting fisheries data alone. Commonly used normal distribution‐based frequentist and Bayesian stock assessment methods are sensitive to outliers, resulting in biased estimates of model parameters that are vital in defining the dynamics of fish stocks and evaluating alternative strategies for fisheries management. Because of the high likelihood of having outliers in fisheries data, frequentist or Bayesian methods robust to outliers are more desirable in fisheries stock assessment. This study reviews three approaches that can be used to develop robust frequentist or Bayesian stock assessment methods. Using simulated fisheries as examples, we demonstrate how these approaches can be used to develop the frequentist and Bayesian stock assessment approaches that are robust to outliers in fisheries data and compare the robust approaches with the commonly used normal distribution‐based approach. The proposed robust approaches provide alternative ways to developing frequentist or Bayesian stock assessment methods.
Learning of foraging skills by fish
Authors: Warburton Kevin
Published: December 2004

This chapter outlines the relationships between a number of key factors that influence learning and memory, and illustrates them by reference to studies on the foraging behaviour of fish. Learning can lead to significant improvements in foraging performance in only a few exposures, and at least some fish species are capable of adjusting their foraging strategy as patterns of patch profitability change. There is also evidence that the memory window for prey varies between fish species, and that this may be a function of environmental predictability. Convergence between behavioural ecology and comparative psychology offers promise in terms of developing more mechanistically realistic foraging models and explaining apparently ‘suboptimal’ patterns of behaviour. Foraging decisions involve the interplay between several distinct systems of learning and memory, including those that relate to habitat, food patches, prey types, conspecifics and predators. Fish biologists, therefore, face an interesting challenge in developing integrated accounts of fish foraging that explain how cognitive sophistication can help individual animals to deal with the complexity of the ecological context.
Impact of a Graduate Entry Programme on a Medical School Library service
Authors: Martin Sam
Published: December 2004

The aim of this study was to compare the use of library facilities by first year undergraduate medical students and Graduate Entry Programme students (GEP). More specifically it tried to determine which library services (if any) were more frequently used by GEP so that this could be taken into account in future Information Services planning. A questionnaire on the use of Library and Information Services was posted to all first year GEP students and undergraduates on the 5‐year course. In addition, user statistics of library entry and borrowing were collated from gate readings and the library Unicorn management system. Overall, GEP students were found to make a greater daily/weekly use of library facilities than undergraduates on the 5‐year course. The facilities most used by both sets of students were essential texts, e‐mail, PCs and study facilities. Computer Aided Learning packages, journals and video facilities were least used. However, on a daily/weekly basis GEP students made 74% more use of journals (P < 0.01), 59% more use of e‐journals (P < 0.05), 36% more use photocopiers (P < 0.05), 42% more use of printers (P < 0.05), 56% more use of the library catalogue (P < 0.05) and 50% more use of databases (P < 0.05). This difference in use should be taken into account by LIS providers as there is expected to be an increase in fast‐track graduate courses offered by medical schools throughout the UK.
Effectiveness of training health professionals in literature search skills using electronic health databases—a critical appraisal
Authors: Garg Anupama , Turtle Kathleen M.
Published: December 2004

The objective was to assess the effect on health professionals’ skills of one to eight hours literature search and retrieval training from electronic health databases. We searched: Cochrane library (2002; Issue 3), medline (1977–2002/5), embase (1980–2002/7); cinahl (1982–2002/5); assia (1982–2002/7), bni (1994–2002/5), eric (1985–2002/6); lisa (1969—current), NRR (2002, Issue 2), the world‐wide‐web and references. The selection criteria consisted of randomised controlled trials, controlled before and after, and controlled cohort studies in comparison with no training. The intervention had to be one to eight hours training in literature search and retrieval skills for health professionals. The outcome was the effect on health professionals’ literature search and retrieval skill levels measured through reliable instruments. For data collection and ana‐lysis, one reviewer extracted data and assessed the quality of the studies and the second reviewer checked it. The results indicate that there is some evidence of positive impact on health professionals’ skill levels in literature searching and they find the training useful. In conclusion, the size of the positive effect is debatable as only three small and methodologically weak studies met the inclusion criteria and out of those only two showed the positive effect.
Effectiveness of cleaning methodologies used for removal of physical, chemical and microbiological residues from produce
Authors: Michaels Barry , Gangar Vidhya , Schattenberg Herb , Blevins Matthew , Ayers Troy
Published: December 2004

An increasing number of disease outbreaks have been associated with produce, while pesticide levels continue to be a safety concern. With increased health awareness, fresh produce consumption has increased. As there is a need for microbial and pesticide removal intervention measures of proven efficacy to maintain confidence in food service produce preparation, a series of experiments were undertaken. Produce cleaning methods were tested by measuring removal of gross dirt, wax and environmental contaminants present on produce surface. Tests were performed on apples, cucumbers and lemons using water wash, produce brush, produce cleaner, produce cleaner with paper towel wipe, and water wash and paper towel wipe. Water rinse and paper towel dry was found superior to all other methods tested. Apples contaminated with a cocktail of pesticides were tested in waxed and unwaxed state. Following cleaning by various methods, including produce wash and produce brush, pesticides on skins were extracted and analyzed to determine concentrations of organophosphorous and organochlorine pesticides. In these experiments, it was shown that any treatment that included wiping with paper towels showed increased effectiveness over similar treatments or controls. Microbial efficacy experiments were performed involving 21 different types of laboratory inoculated produce. Two types of inoculum were employed, Tryptone Soya broth (TSB) and ground beef. After inoculation, produce was cleaned by dry wiping with paper towel, using water wash air dry, water wash paper towel dry or dipped in 200 p.p.m. chlorine dip for either 5 s or 1 min and compared to baseline values. One‐minute dip in 200 p.p.m. chlorine solution was more effective than rinsing and drying with a paper towel when TSB inoculum was used (P < 0.05). The effectiveness of the 200 p.p.m. chlorine dip diminished if ground beef was used as a test inoculum, with water rinse and paper towel providing significantly (P < 0.05) improved results. The efficacy shown by paper towels usage in this diverse set of experiments is based on frictional removal of offending soils.
Energetics of chemolithoautotrophy in the hydrothermal system of Vulcano Island, southern Italy
Authors: Amend Jan P. , Rogers Karyn L. , Shock Everett L. , Gurrieri Sergio , Inguaggiato Salvatore
Published: December 2004

The hydrothermal system at Vulcano, Aeolian Islands (Italy), is home to a wide variety of thermophilic, chemolithoautotrophic archaea and bacteria. As observed in laboratory growth studies, these organisms may use an array of terminal electron acceptors (TEAs), including O2, , Fe(III), , elemental sulphur and CO2; electron donors include H2, , Fe2+, H2S and CH4. Concentrations of inorganic aqueous species and gases were measured in 10 hydrothermal fluids from seeps, wells and vents on Vulcano. These data were combined with standard Gibbs free energies () to calculate overall Gibbs free energies (ΔGr) of 90 redox reactions that involve 16 inorganic N‐, S‐, C‐, Fe‐, H‐ and O‐bearing compounds. It is shown that oxidation reactions with O2 as the TEA release significantly more energy (normalized per electron transferred) than most anaerobic oxidation reactions, but the energy yield is comparable or even higher for several reactions in which , or Fe(III) serves as the TEA. For example, the oxidation of CH4 to CO2 coupled to the reduction of Fe(III) in magnetite to Fe2+ releases between 94 and 123 kJ/mol e−, depending on the site. By comparison, the aerobic oxidation of H2 or reduced inorganic N‐, S‐, C‐ and Fe‐bearing compounds generally yields between 70 and 100 kJ/mol e−. It is further shown that the energy yield from the reduction of elemental sulphur to H2S is relatively low (8–19 kJ/mol e−) despite being a very common metabolism among thermophiles. In addition, for many of the 90 reactions evaluated at each of the 10 sites, values of ΔGr tend to cluster with differences < 20 kJ/mol e−. However, large differences in ΔGr (up to ∼ 60 kJ/mol e−) are observed in Fe redox reactions, due largely to considerable variations in Fe2+, H+ and H2 concentrations. In fact, at the sites investigated, most variations in ΔGr arise from differences in composition and not in temperature.
Multiple sulphur isotopic interpretations of biosynthetic pathways: implications for biological signatures in the sulphur isotope record
Authors: Farquhar James , Johnston David T. , Wing Boswell A. , Habicht Kirsten S. , Canfield Donald E. , Airieau Sabine , Thiemens Mark H.
Published: December 2004

Isotopic fractionations produced by biosynthetic processes are the result of networks of individual biochemical reactions that operate at differing efficiencies and with distinct fractionation factors. These reaction networks determine the magnitude and direction of the net isotopic fractionation associated with a given process. Here we examine the ways that biological reaction networks control mass‐dependent isotopic fractionations of multiple sulphur isotopes. We describe how material‐flow through some networks can produce characteristic multiple‐sulphur‐isotope signatures that differ from those produced by their constituent steps and demonstrate that experimental results with Archaeaglobus fulgidus can be evaluated using multiple sulphur isotopes in the context of previously published models for dissimilatory sulphate reduction. Our evaluation of these data is consistent with the interpretation that the dependence of sulphur isotope fractionation on external sulphate concentration is rooted in differences between the forward and reverse  ↔ adenosine‐5′‐phosphosulphate (APS) ↔  steps. The framework provided by our analysis has the potential to evaluate the biosynthetic pathways that produce the isotopic fractionations, to isolate the primary sources of isotopic fractionations (sulphate reduction or disproportionation reactions) and to establish criteria to identify the signature of specific sulphur metabolisms in the geological record. The results highlight the new types of information that can be obtained by including measurements of δ33S {δ33S = [(33S/32S)sample/(33S/32S)reference − 1]*1000} with measurements of δ34S.
Treatment perspectives for human African trypanosomiasis
Authors: Bouteille Bernard , Oukem Odile , Bisser Sylvie , Dumas Michel
Published: December 2004

Human African trypanosomiasis (HAT), or sleeping sickness, is currently on the rise. HAT develops in two stages, the first involving the hemolymphatic system, and the second, the neurological system. Left untreated, HAT is invariably fatal. There have been no therapeutic advances in more than 40 years. Stage 1 can be treated with pentamidine and suramin, but stage 2 can only be treated with melarsoprol, a toxic arsenic derivative that has a 2–12% incidence of fatal side‐effects (encephalopathy). Eflornithine has never achieved widespread use because it is difficult to administer under field conditions. Nifurtimox has been used successfully in the treatment of American trypanosomiasis, or Chagas disease, but only in small studies or as a compassionate use treatment. There is little research and development for new drugs in this area: only one prodrug is in the clinical development phase, a pentamidine analog that offers hope for the replacement of injectable pentamidine with an orally administered drug. Current efforts appear to be focused on reevaluating older drugs. A course of treatment with melarsoprol for 10 days at 2.2 mg/kg/day is now in the multicenter evaluation phase. Orally administered eflornithine is also slated for reevaluation. In addition, studies of drug combinations are recommended to determine possible combined or synergistic effects and find ways to reduce toxicity.
Albendazole for the treatment of echinococcosis
Authors: John Horton
Published: December 2004

Twenty years after the first cases of echinococcal disease were treated with albendazole, it has become an important component in the overall management of both cystic and alveolar echinococcosis. This paper reviews some of the key steps and issues facing those who work in clinical research and who deal on a day‐to‐day basis with echinococcal disease. In many situations, chemotherapy alone is sufficient, but it is also used as an adjunct to surgery and to minimally invasive approaches to cyst management. While treatment may not be as effective as hoped, attempts to provide new regimens are progressing to increase cure rates further. There is now a greater understanding of the limitations of all approaches, and treatment guidelines as developed by the World Health Organization are now widely followed. As diagnostic tools are ever more widely available, the question as to who should be treated in endemic communities has to be answered.
Treatment of cutaneous larva migrans and Toxocara infection
Authors: Caumes Eric
Published: December 2004

The treatment of cutaneous larva migrans and Toxocara infection relies on antihelminthic agents such as thiabendazole, albendazole and ivermectin. The efficacy of these agents varies according to the helminthic disease.
High Anti‐Helicobacter pylori Antibody Seropositivity Associated with the Combination of IL‐8–251TT and IL‐10–819TT Genotypes
Authors: Hamajima Nobuyuki , Katsuda Nobuyuki , Matsuo Keitaro , Saito Toshiko , Hirose Kaoru , Inoue Manami , Zaki Toshiro Take , Tajima Kazuo , Tominaga Suketami
Published: December 2004

abstract

Background. Helicobacter pylori induces inflammation of gastric mucosa regulated by several interleukins. This study examined associations between anti‐Helicobacter pylori immunoglobulin G antibody seropositivity and functional polymorphisms of interleukin‐8 T‐251 A and interleukin‐10 T‐819C.

Materials and Methods. The subjects were 454 health check‐up examinees (126 males and 328 females) without a history of cancer, aged 35–85 years, residing in Nagoya, Japan. After written informed consent was obtained individually, residual blood was anonymously applied for anti‐Helicobacter pylori immunoglobulin G antibody testing and genotyping by the polymerase chain reaction with confronting two‐pair primers.

Results. The genotype frequency of interleukin‐8 T‐251 A was 52.2% for TT, 39.5% for TA, and 8.3% for AA, and that of interleukin‐10 T‐819C was 49.5% for TT, 39.9% for TC and 10.6% for CC. Although the differences in the positive rates among the genotypes were not marked, 115 individuals with interleukin‐8–251TT (low expression genotype) and interleukin‐10–819TT (high expression genotype) had a higher rate (63.5%) than the others (52.0%). Relative to the combination of interleukin‐8–251TT and interleukin‐10–819TT, the sex‐age‐adjusted odds ratio for those with the other combinations was 0.62 (95% confidence interval, 0.39–0.98). The adjusted odds ratio among 65 current smokers was 0.13 (0.03–0.61).

Conclusions. The observed association suggests that individuals with interleukin‐8–251TT and interleukin‐10–819TT, a combination presumably causing mild inflammation, have a higher probability of the continuing Helicobacter pylori infection, especially among current smokers.
Lafutidine, a Novel Histamine H2‐Receptor Antagonist, vs. Lansoprazole in Combination with Amoxicillin and Clarithromycin for Eradication of Helicobacter pylori
Authors: Isomoto Hajime , Inoue Kenichiro , Furusu Hisashi , Nishiyama Hitoshi , Shikuwa Saburo , Omagari Katsuhisa , Mizuta Yohei , Murase Kunihiko , Murata Ikuo , Kohno Shigeru
Published: December 2004

abstract

Background. In contrast to the growing amount of data concerning proton pump inhibitor‐based triple therapy for Helicobacter pylori infection, it is still controversial whether proton pump inhibitor can be replaced by H2 receptor antagonist without compromising efficacy. Lafutidine is a novel potent H2 receptor antagonist with gastroprotective activities such as enhancement of gastric mucosal blood flow.

Methods. 122 outpatients with positive cultures and subsequent successful cultivation of H. pylori for antimicrobial susceptibility tests were randomized to receive a 7‐day course of either lafutidine (20 mg twice daily) or lansoprazole (30 mg twice daily), plus clarithromycin (200 mg twice daily) and amoxicillin (750 mg twice daily). Eradication was considered successful if the rapid urease test, culture, histology and [13]C‐urea breath test were all negative at least 4 weeks after cessation of therapy. Cytochrome p450 2C19 genotype status using polymerase chain reaction‐restriction fragment length polymorphism was also studied.

Results. On intention‐to‐treat basis, H. pylori cure was achieved in 52 of 61 (85.2%) patients and 49 of 61 (80.3%) patients for the lafutidine‐ and lansoprazole‐based therapies, respectively. The predicted 95% confidential intervals for the 4.9% of the difference were −1.8–11.6%. Using per protocol analysis, the eradication rates were 88.2% (52/59) and 84.5% (49/58), respectively. The predicted 95% confidential intervals for the 3.7% of the difference were −2.6–10.0%. Adverse events were observed in five and six patients, from the lafutidine and lansoprazole groups, respectively, but they were generally mild. Genetic predisposition of cytochrome p450 2C19 had no significant influence on treatment outcome in both regimens.

Conclusions. The lafutidine‐clarithromycin‐amoxicillin therapy yielded satisfactory results for eradicating H. pylori, which was comparable with those of the lansoprazole‐based regimen with the same drug combination.
Does N‐acetyl Cystein Affect the Sensitivity and Specificity of Helicobacter pylori Stool Antigen Test?
Authors: Demirtürk Levent , Yazgan Yusuf , Tarçın Orhan , Özel Melih , Diler Muhittin , Öncül Oral , Yıldırım Şükrü
Published: December 2004

abstract

Background. N‐acetyl cystein, a mucolytic agent, might make Helicobacter pylori antigens shed more easily to stool, and might therefore contribute to the diagnostic accuracy of the Helicobacter pylori stool antigen test. The aim of this study is to investigate if N‐acetyl cystein contributes to the diagnostic accuracy of the Helicobacter pylori stool antigen test by increasing the sensitivity and specificity of the test.

Materials and Methods. 107 patients were separated into treatment and placebo groups. The AC group (n = 53) was given 5 ml of acetyl cystein (4%) t.i.d. and the Placebo group (n = 54) was given placebo, for 3 days. Helicobacter pylori status was determined by both histology and CLOtest. Stool samples were assayed using a specific ELISA kit for Helicobacter pylori stool antigen.

Results. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of Helicobacter pylori stool antigen test were 76%, 79%, 90%, 55%, and 77%, respectively, in AC group; and 85%, 89%, 93%, 76% and 86%, respectively, in placebo group.

Conclusions. N‐acetyl cystein did not increase, and actually decreased, the sensitivity and specificity of the Helicobacter pylori stool antigen test according to our results. We believe that this finding can be taken into consideration when setting up the exclusion criteria for future studies, which will use Helicobacter pylori stool antigen tests.
Gastric Mucosal Blood Flow Changes in Helicobacter pylori Infection and NSAID‐Induced Gastric Injury
Authors: Elizalde J. Ignasi , Mendez Asuncion , Gomez Julia , Del Rivero Maria , Gironella Meritxell , Closa Daniel , Quintero Enrique , Pique Josep M.
Published: December 2004

abstract

Background. The impact of H. pylori infection on gastric mucosal blood flow and NSAID‐induced gastric damage is unclear.

Aim. To study the effects of H. pylori infection on gastric mucosal blood flow, both at basal conditions and after NSAID exposure, and its relation with mucosal damage and nitric oxide production.

Methods. Gastric mucosal blood flow, nitric oxide production and gastric damage were assessed in time after H. pylori SS1 or E. coli inoculation in mice. Experiments were conducted in basal conditions or after oral exposure to indomethacin (20 mg/kg).

Results. H. pylori infected mice exhibited a significant increase in gastric blood flow and gastric nitric oxide production 1 week after infection, but those parameters returned to basal levels by 4 weeks. NSAID challenge elicited a similar reduction in gastric blood flow [25–35%] in H. pylori‐infected and control animals. However, only 1 week H. pylori‐infected mice, which exhibited a significant baseline hyperemia, were able to maintain gastric blood flow values within the normal range after NSAID exposure. NSAID‐induced gastric damage was increased in H. pylori‐infected mice by 4 weeks, but not 1 week after infection.

Conclusions. Underlying H. pylori infection aggravates acute NSAID‐induced gastric damage. However, at early phases, gastric hyperemia associated with increased nitric oxide production may exert some protective role.
Histology of Gastritis and Helicobacter pylori Infection in Thailand: a Nationwide Study of 3776 Cases
Authors: Atisook Kanit , Kachinthorn Udom , Luengrojanakul Pairoj , Tanwandee Tawesak , Pakdirat Puripakorn , Puapairoj Anucha
Published: December 2004

abstract

Background. Dyspepsia is a very common problem in Thailand. Etiology of gastritis, incidence of Helicobacter pylori and mode of transmission of Helicobacter pylori infection in the country was proposed.

Methods. A nation‐wide study of gastric biopsy in 3776 dyspeptic patients from six different geographic regions for incidence of gastritis, type of gastritis, incidence of H. pylori infection, gastric atrophic change and intestinal metaplasia in three age‐groups of each region was done.

Results. 58.7% of dyspeptic patients had histological gastritis. Pangastritis was the most common type (77.3%) with mostly mild active inflammation (60.6%) and was found most commonly in the age group 31–60 years. Incidence of gastritis was slightly lower in the coastal and peninsular community compared with the mountain, jungle, semiarid plateau and fertile plain communities. Geographic factor, socioeconomic status and dietary habit were proposed to be important factors in inducing gastritis. H. pylori infection was found in 48.2% of dyspeptic patients with high incidence in the age‐group 31–60 years (63.7%) and 98.2% of H. pylori infection was found to be associated with gastritis. Semi‐arid plateau, mountain, jungle and fertile plain communities had high incidences of H. pylori infection varying from 54.0 to 67.1% while the coastal and peninsular communities had low incidences of 32%. Oral to oral spread is proposed to be the mode of bacterial transmission. Incidences of gastric atrophic change and intestinal metaplasia were low in this country and were found in 11.6% and 8.2% of subjects, respectively, with no significantly different distribution in geographic regions. Type I or intestinal type was found to be the most common type of intestinal metaplasia.
Cost‐Effectiveness of Antiepileptic Drugs in Migraine Prophylaxis
Authors: Adelman James U. , Adelman Leon C. , Von Seggern Randal
Published: December 2004

Objective.—To analyze the cost‐effectiveness of antiepileptics in migraine prophylaxis.

Methods.—A cost‐effectiveness analysis was performed using efficacy data from three recent, double‐blind, placebo‐controlled, clinical trials of antiepileptic drugs studied for migraine prevention and cost data. Two measures of cost‐effectiveness were used: cost per headache prevented and the cost‐equivalent number.

Results.—In the double‐blind, placebo‐controlled, clinical trials evaluated, three antiepileptic drugs were shown to be effective in migraine prevention. All three antiepileptic drugs had high costs per migraine reduced. Gabapentin was the most costly at $138.00 per migraine prevented, whereas the cost per migraine prevented with topiramate was $114.80 and with divalproex sodium was $48.00. For migraine prevention divalproex sodium became cost‐effective with 10 migraines per month, whereas gabapentin and topiramate required considerably more migraines per month to be cost‐effective.

Conclusions.—Antiepileptic drugs have proven effectiveness in migraine prophylaxis. However, in patients responsive to their acute care medications, the antiepileptic drugs are only cost‐effective for those patients with a high frequency of migraines and those with comorbid diseases. Future studies should be done with antiepileptic drugs in patients exhibiting a migraine frequency of 10 or more headaches per month.
Reliability and Validity of the Migraine Therapy Assessment Questionnaire
Authors: Chatterton Mary Lou , Lofland Jennifer H. , Shechter Aaron , Curtice Walter Scott , Hu X. Henry , Lenow Jeffrey , Smullens Stanton N. , Nash David B. , Silberstein Stephen D.
Published: December 2004

Objective.—To determine the reliability and validity of the Migraine Therapy Assessment Questionnaire (MTAQ).

Design/Methods.—Eligible patients between ages 18 and 65 with at least one migraine per month, a physician visit in the preceding 6 months, and a migraine diagnosis were recruited from physician offices in the Philadelphia area. Participants completed the MTAQ, Short Form‐36 (SF‐36), the Migraine Disability Assessment Score (MIDAS), the Beck Depression Inventory, a demographic questionnaire, and a medication use survey. The first 100 participants completed a second MTAQ approximately 2 weeks later. The test‐retest reliability, construct, and predictive validity of the MTAQ were assessed.

Results.—Two hundred fifty‐one patients were recruited; 243 patients were assessable. All MTAQ questions had a kappa statistic of .5 or higher and an agreement of at least 76%. There was a significant level of agreement (.71) for the MTAQ summary score. MTAQ items regarding control, frequency, work loss, resource use, and satisfaction were associated with significant differences in SF‐36 scores. MTAQ items related to work loss, emergency department use, headache frequency, and control were associated with days missed from work and degree of disability as measured by MIDAS. Suboptimal migraine management was significantly associated with MTAQ items indicating three or more headaches per month, missing time from work or school, taking daily medication for headaches, and having an emergency department visit in the last 6 months.

Conclusion.—MTAQ is a reliable and valid questionnaire to identify migraineurs whose migraine management may be suboptimal in a primary care setting.
Relief of Tension‐type Headache Symptoms in Subjects with Temporomandibular Disorders Treated with Botulinum Toxin‐A
Authors: Freund Brian J. , Schwartz Marvin
Published: December 2004

Background.—Temporomandibular disorder (TMD) and chronic tension headaches clinically coexist in many individuals. Generally considered as separate pathological entities, they have been clinically treated by different means.

Objective.—To determine the utility of treatement with botulinum toxin for patients with coexisting TMD and chronic tension type headache.

Methods.—In this open‐label study of 60 subjects with chronic TMD, 46 subjects also met the diagnostic criteria for chronic tension headache. All 60 subjects were treated with 150 units of botulinum toxin‐A injected into the masticatory muscles, specifically 50 units into each masseter and 25 units into each temporalis muscle.

Results.—Thirty‐eight of 60 subjects (63%) reported a 50% improvement in their facial pain during the follow‐up period. The subset of 46 subjects with chronic tension headache and TMD symptoms reported a 50% or greater improvement in headache pain as well. The number of headache free days also improved postinjection.

Conclusion.—These results suggest that the masticatory muscles, specifically the temporalis, may be involved in the pathogenesis of this form of chronic tension headache found in association with TMD.
Efficacy, Safety, and Tolerability of Oral Eletriptan for Treatment of Acute Migraine: A Multicenter, Double‐Blind, Placebo‐Controlled Study Conducted in the United States
Authors: Sheftell Fred , Ryan Robert , Pitman Verne , For The Eletriptan Steering Committee
Published: December 2004

Objective.—To investigate the efficacy, consistency, safety, and tolerability of oral eletriptan in the acute treatment of three migraine attacks.

Background.—Eletriptan is a selective 5‐HT1B/1D agonist member of a class of agents known to be effective in the acute treatment of migraine.

Methods.—Thirteen hundred thirty‐four patients were randomized to 20 mg, 40 mg, or 80 mg of eletriptan, or placebo and could treat up to three attacks. The primary efficacy endpoint was 2‐hour headache response for the first attack. Secondary endpoints included associated symptom relief, and pain‐free, sustained pain‐free, and consistency of response.

Results.—Eletriptan 20 mg, 40 mg, and 80 mg achieved significantly (P  <  .0001) better headache response rates than placebo at 2 hours (47%, 62%, and 59%, respectively, versus 22%) and 4 hours (64%, 76%, and 79%, respectively, versus 25%). Headache response was observed to be rapid, showing improvement at 0.5 hour and 1 hour. Two‐hour pain‐free response rates for eletriptan 20 mg, 40 mg, and 80 mg were 14%, 27%, and 27%, respectively, compared with 4% for placebo. Sustained pain‐free response rates were significantly (P  <  .001) better for eletriptan 20 mg (10%), 40 mg (20%), and 80 mg (18%) compared with placebo (3%). Eletriptan had a higher consistency of intrapatient response than placebo in two of three (68% to 82%) and three of three attacks (32% to 60%) versus 16% and 8%, respectively. All eletriptan doses yielded significant functional improvement at 2 hours. Adverse events were generally mild or moderate and transient, with eletriptan 20 mg having an adverse event profile comparable to placebo.

Conclusions.—Eletriptan is efficacious, displaying high consistency of response over multiple attacks, and is well tolerated for the acute treatment of migraine.
Real‐World Experiences in Migraine Therapy With Rizatriptan
Authors: Jamieson Dara , Cutrer F. Michael , Goldstein Jerome , Dayno Jeffrey , Hu X. Henry , On Behalf Of The USMAP Investigators
Published: December 2004

Objective.—To evaluate the effectiveness of rizatriptan for acute migraine treatment and patient satisfaction with the drug in usual clinical practice settings.

Background.—Although rizatriptan has been shown to effectively relieve migraine symptoms in clinical trials, we wished to assess its utility in typical patient care settings.

Design.—Multicenter, open‐label design involving the patients of practicing clinicians.

Methods.—Adult migraineurs treated two migraine attacks with either rizatriptan 10‐mg standard tablets or rizatriptan 10‐mg orally disintegrating tablets in a crossover manner. Participants had not taken rizatriptan previously and chose which formulation to take first. Patients reported their treatment experiences via an interactive voice response system approximately 24 hours after treatment. Prior migraine treatment experiences were reported by patients on a baseline questionnaire completed at participating clinics. We used conditional logistic regression analysis adjusted for treatment sequences to test the statistical significance of comparisons with results recorded on the baseline questionnaire.

Results.—Of the 5388 patients enrolled, 3953 (73%) completed at least one follow‐up and 3183 (59%) completed two follow‐up reports. Patients reported the following outcomes for attacks treated with the rizatriptan tablet and orally disintegrating tablet formulations, respectively, compared with their prior responses to oral usual care medications (P  <  .05 in all comparisons with baseline data): onset of pain relief within 30 minutes postdose: 18% and 23% versus 16%; no or mild headache 2 hours postdose: 66% and 67% versus 37%; largely symptom‐free within 2 hours postdose: 52% and 54% versus 35%; return to usual activities within 2 hours postdose: 50% and 51% versus 31%; and very or somewhat satisfied with treatment: 72% and 74% versus 53%.

Conclusions.—In this “real‐world” setting involving a patient population selected by clinicians, rizatriptan appeared to offer better treatment outcomes than those from prior treatments with other oral migraine medications.
Biofeedback‐Assisted Relaxation in Migraine Headache: Relationship to Cerebral Blood Flow Velocity in the Middle Cerebral Artery
Authors: Vasudeva Sachinder , Claggett Alice L. , Tietjen Gretchen E. , McGrady Angele V.
Published: December 2004

Objective.—To determine if migraineurs with aura respond differently to biofeedback/relaxation than those without aura and, if so, whether the variability in outcome can be explained by blood flow velocity.

Background.—The relationship between cerebral blood flow velocity and treatment response to biofeedback/relaxation in migraine with and without aura is uncertain.

Method.—Twenty migraineurs underwent 12 sessions of biofeedback/relaxation therapy, while 20 controls simply were told to relax on their own. Cerebral blood flow velocity was measured bilaterally in the middle cerebral artery with transcranial Doppler.

Results.—The biofeedback group showed significant (P  <  .05) reductions in pain, depression, and anxiety compared to the control group. Patients with and without aura did equally well. There were significant (P  <  .05) left to right blood flow velocity differences only in the migraine with aura group. Maximum blood flow velocities were significantly higher (P  <  .05) in the migraine with aura group than in the cohort without aura. There was an inverse correlation between indicators of anxiety and blood flow velocity, perhaps related to hyperventilation‐induced constriction in the small vessels distal to the middle cerebral artery.

Conclusion.—The positive treatment response to biofeedback/relaxation in migraine headache is not related to presence of aura, nor to changes in blood flow velocity, but may be associated with reduction in anxiety and depression.