bluuebunny/crossref_metadata_2025 huggingface dataset:
North American earthworms native to Vancouver Island and the Olympic Peninsula
Authors: McKey-Fender Dorothy , Fender William M. , Marshall Valin G.
Published: May 2008

The following native earthworms from the spruce-hemlock forest region of western North America are described: Lumbricidae: Bimastos lawrenceae Fender, n.sp. from Vancouver Island; Megascolecidae: five new species of Arctiostrotus McKey-Fender, 1982, including A. vancouverensis McKey-Fender, n.sp. from Vancouver Island and the Olympic Peninsula, A. pluvialis McKey-Fender, n.sp. and A. adunatus McKey-Fender, n.sp. from the Olympic Peninsula, A. fontinalis McKey-Fender, n.sp. from northwestern Oregon and western Washington, and A. johnsoni McKey-Fender, n.sp. from western Washington. The known species A. perrieri (Benham, 1892) and A. altmani (Gates, 1942) are redescribed, as is the Vancouver Island population of Toutellus oregonensis (Smith, 1937). Ecology, biology, and references to some associated biota and a key are included.
Changes in the distribution of extracellular matrix components during neural crest development in Xiphophorus spp. embryos
Authors: Sadaghiani Bahram , Crawford Bruce J. , Vielkind Juergen R.
Published: May 2008

The changes in distribution of chondroitin sulfate proteoglycans (CSs) and fibronectin (FN), two major components of the extracellular matrix (ECM), are described during the development and migration of neural crest cells in two Xiphophorus species offish, X. helleri (swordtail) and X. maculatus (platyfish), using immunohistochemistry. A detailed description of the developmental changes in HNK-1-positive ECM components is also provided and compared with those of CSs and FN. HNK-1 antigen was also used as a marker for the neural crest cells. Weak staining for CSs, FN, and HNK-1-positive ECM was present in the neural crest cell migration pathways prior to migration of the cells. The level of staining increased dramatically during migration of these cells and decreased again after migration was nearly completed. Staining for CSs was more widespread than staining for FN, while the HNK-1 staining pattern was more clearly restricted to the migratory pathways than those seen with the other two antibodies. The correlation between the spatiotemporal relationship of these ECM components and the segregation and migration of neural crest cells suggests that these ECM molecules may be involved in both initiating and guiding the migration of neural crest cells in these fish. The HNK-1-positive ECM may play a more critical role than CSs and FN.
Habitat–abundance relationships of the earthworm Eisenia rosea (Savigny) (Lumbricidae), using principal component regression analysis
Authors: Liang Qiwei , Thomson Alan J.
Published: May 2008

Principal component regression analysis was used to investigate the relationships between the abundance of the earthworm Eisenia rosea and soil characteristics at two Ontario locations. To this end we summarized our environmental data matrix with principal component analysis and then used the first several principal components in a multiple regression analysis. This two-step procedure remedies problems associated with multicollinearity among our environmental variables. At one location, moisture was the main factor correlating with the abundance of E. rosea. At the other location, because high soil bulk density can compensate for low moisture, E. rosea abundance did not correlate with moisture.
ANALYTICAL APPROXIMATIONS TO THE SCHRÖDINGER EQUATION FOR A SECOND PÖSCHL–TELLER-LIKE POTENTIAL WITH CENTRIFUGAL TERM
Authors: DONG SHI-HAI , QIANG WEN-CHAO , GARCÍA-RAVELO J.
Published: May 2008

The bound state solutions of the Schrödinger equation for a second Pöschl–Teller-like potential with the centrifugal term are obtained approximately. It is found that the solutions can be expressed in terms of the hypergeometric functions 2F1(a, b; c; z). To show the accuracy of our results, we calculate the eigenvalues numerically for arbitrary quantum numbers n and l. It is found that the results are in good agreement with those obtained by other method for short-range potential. Two special cases for l = 0 and V1 = V2 are also studied briefly.
GRAVITATIONAL HIGGS MECHANISM AND MASSIVE GRAVITY
Authors: KAKUSHADZE ZURAB
Published: May 2008

In Modern Physics Letters A15, 2265 (2000), in the context of domain wall backgrounds, it was shown that spontaneous breaking of diffeomorphism invariance results in gravitational Higgs mechanism. Recently in arXiv:0708.3184 't Hooft discussed gravitational Higgs mechanism in the context of obtaining massive gravity directly in four dimensions, and pointed out some subtleties with unitarity. We attribute these subtleties to breaking timelike diffeomorphisms, and discuss gravitational Higgs mechanism with all but timelike diffeomorphisms spontaneously broken. The resulting background is no longer flat but exhibits expansion, which is linear in time. For space–time dimensions D ≤ 10 the background is stable and has no nonunitary propagating modes. The absence of nonunitary modes is due to the unbroken timelike diffeomorphism invariance. The physical states correspond to those of a massive graviton. The effective mass squared of the graviton is positive for D < 10, and vanishes for D = 10. For D > 10 the graviton modes become effectively tachyonic. The special value of D = 10, which coincides with the critical dimension of superstring theory, arises in our setup completely classically.
Coordination in emergency response management
Authors: Chen Rui , Sharman Raj , Rao H. Raghav , Upadhyaya Shambhu J.
Published: May 2008

Developing a framework to analyze coordination patterns occurring in the emergency response life cycle.
Correctness-aware high-level functional matching approaches for semantic Web services
Authors: Elgedawy Islam , Tari Zahir , Thom James A.
Published: May 2008

Service matching approaches trade precision for recall, creating the need for users to choose the correct services, which obviously is a major obstacle for automating the service discovery and aggregation processes. Our approach to overcome this problem, is to eliminate the appearance of false positives by returning only the correct services. As different users have different semantics for what is correct, we argue that the correctness of the matching results must be determined according to the achievement of users' goals: that only services achieving users' goals are considered correct. To determine such correctness, we argue that the matching process should be based primarily on the high-level functional specifications (namely goals, achievement contexts, and external behaviors). In this article, we propose models, data structures, algorithms, and theorems required to correctly match such specifications. We propose a model calledG+, to capture such specifications, for both services and users, in a machine-understandable format. We propose a data structure, called a Concepts Substitutability Graph (CSG), to capture the substitution semantics of application domain concepts in a context-based manner, in order to determine the semantic-preserving mapping transformations required to match differentG+models. We also propose a behavior matching approach that is able to match states in an m-to-n manner, such that behavior models with different numbers of state transitions can be matched. Finally, we show how services are matched and aggregated according to theirG+models. Results of supporting experiments demonstrate the advantages of the proposed service matching approaches.
Image retrieval
Authors: Datta Ritendra , Joshi Dhiraj , Li Jia , Wang James Z.
Published: May 2008

We have witnessed great interest and a wealth of promise in content-based image retrieval as an emerging technology. While the last decade laid foundation to such promise, it also paved the way for a large number of new techniques and systems, got many new people involved, and triggered stronger association of weakly related fields. In this article, we survey almost 300 key theoretical and empirical contributions in the current decade related to image retrieval and automatic image annotation, and in the process discuss the spawning of related subfields. We also discuss significant challenges involved in the adaptation of existing image retrieval techniques to build systems that can be useful in the real world. In retrospect of what has been achieved so far, we also conjecture what the future may hold for image retrieval research.
Breaking up is hard to do
Authors: Cobleigh Jamieson M. , Avrunin George S. , Clarke Lori A.
Published: May 2008

Finite-state verification techniques are often hampered by the state-explosion problem. One proposed approach for addressing this problem is assume-guarantee reasoning, where a system under analysis is partitioned into subsystems and these subsystems are analyzed individually. By composing the results of these analyses, it can be determined whether or not the system satisfies a property. Because each subsystem is smaller than the whole system, analyzing each subsystem individually may reduce the overall cost of verification. Often the behavior of a subsystem is dependent on the subsystems with which it interacts, and thus it is usually necessary to provide assumptions about the environment in which a subsystem executes. Because developing assumptions has been a difficult manual task, the evaluation of assume-guarantee reasoning has been limited. Using recent advances for automatically generating assumptions, we undertook a study to determine if assume-guarantee reasoning provides an advantage over monolithic verification. In this study, we considered
all
two-way decompositions for a set of systems and properties, using two different verifiers, FLAVERS and LTSA. By increasing the number of repeated tasks in these systems, we evaluated the decompositions as they were scaled. We found that in only a few cases can assume-guarantee reasoning verify properties on larger systems than monolithic verification can, and in these cases the systems that can be analyzed are only a few sizes larger. Although these results are discouraging, they provide insight about research directions that should be pursued and highlight the importance of experimental evaluation in this area.
Effective typestate verification in the presence of aliasing
Authors: Fink Stephen J. , Yahav Eran , Dor Nurit , Ramalingam G. , Geay Emmanuel
Published: May 2008

This article addresses the challenge of sound typestate verification, with acceptable precision, for real-world Java programs. We present a novel framework for verification of typestate properties, including several new techniques to precisely treat aliases without undue performance costs. In particular, we present a flow-sensitive, context-sensitive, integrated verifier that utilizes a parametric abstract domain combining typestate and aliasing information. To scale to real programs without compromising precision, we present a staged verification system in which faster verifiers run as early stages which reduce the workload for later, more precise, stages.

We have evaluated our framework on a number of real Java programs, checking correct API usage for various Java standard libraries. The results show that our approach scales to hundreds of thousands of lines of code, and verifies correctness for 93% of the potential points of failure.
Combining symbolic execution with model checking to verify parallel numerical programs
Authors: Siegel Stephen F. , Mironova Anastasia , Avrunin George S. , Clarke Lori A.
Published: May 2008

We present a method to verify the correctness of parallel programs that perform complex numerical computations, including computations involving floating-point arithmetic. This method requires that a sequential version of the program be provided, to serve as the specification for the parallel one. The key idea is to use model checking, together with symbolic execution, to establish the equivalence of the two programs. In this approach the path condition from symbolic execution of the sequential program is used to constrain the search through the parallel program. To handle floating-point operations, three different types of equivalence are supported. Several examples are presented, demonstrating the approach and actual errors that were found. Limitations and directions for future research are also described.
Impact of classes of development coordination tools on software development performance
Authors: Tiwana Amrit
Published: May 2008

Although a diverse variety of software development coordination tools are widely used in practice, considerable debate surrounds their impact on software development performance. No large-scale field research has systematically examined their impact on software development performance. This paper reports the results of a multinational field study of software projects in 209 software development organizations to empirically examine the influence of six key classes of development coordination tools on the efficiency (reduction of development rework, budget compliance) and effectiveness (defect reduction) of software development performance.

Based on an in-depth field study, the article conceptualizes six holistic classes of development coordination tools. The results provide nuanced insights—some counter to prevailing beliefs—into the relationships between the use of various classes of development coordination tools and software development performance. The overarching finding is that the performance benefits of development coordination tools are contingent on the salient types of novelty in a project. The dimension of development performance—efficiency or effectiveness—that each class of tools is associated with varies systematically with whether a project involves conceptual novelty, process novelty, multidimensional novelty (both process and conceptual novelty), or neither. Another noteworthy insight is that the use of some classes of tools introduces an efficiency-effectiveness tradeoff. Collectively, the findings are among the first to offer empirical support for the varied performance impacts of various classes of development coordination tools and have important implications for software development practice. The paper also identifies several promising areas for future research.
An Integrated Approach for Modeling Learning Patterns of Students in Web-Based Instruction
Authors: Chen Sherry Y. , Liu Xiaohui
Published: May 2008

Web-based instruction (WBI) programs, which have been increasingly developed in educational settings, are used by diverse learners. Therefore, individual differences are key factors for the development of WBI programs. Among various dimensions of individual differences, the study presented in this article focuses on cognitive styles. More specifically, this study investigates how cognitive styles affect students' learning patterns in a WBI program with an integrated approach, utilizing both traditional statistical and data-mining techniques. The former are applied to determine whether cognitive styles significantly affected students' learning patterns. The latter use clustering and classification methods. In terms of clustering, the K-means algorithm has been employed to produce groups of students that share similar learning patterns, and subsequently the corresponding cognitive style for each group is identified. As far as classification is concerned, the students' learning patterns are analyzed using a decision tree with which eight rules are produced for the automatic identification of students' cognitive styles based on their learning patterns. The results from these techniques appear to be consistent and the overall findings suggest that cognitive styles have important effects on students' learning patterns within WBI. The findings are applied to develop a model that can support the development of WBI programs.
Investigating the Roles of Knowledge and Cognitive Abilities in Older Adult Information Seeking on the Web
Authors: Sharit Joseph , Hernández Mario A. , Czaja Sara J. , Pirolli Peter
Published: May 2008

This study investigated the influences of knowledge, particularly Internet, Web browser, and search engine knowledge, as well as cognitive abilities on older adult information seeking on the Internet. The emphasis on aspects of cognition was informed by a modeling framework of search engine information-seeking behavior. Participants from two older age groups were recruited: twenty people in a younger-old group (ages 60-70) and twenty people in an older-old group (ages 71-85). Ten younger adults (ages 18-39) served as a comparison group. All participants had at least some Internet search experience. The experimental task consisted of six realistic search problems, all involving information related to health and well-being and which varied in degree of complexity. The results indicated that though necessary, Internet-related knowledge was not sufficient in explaining information-seeking performance, and suggested that a combination of both knowledge and key cognitive abilities is important for successful information seeking. In addition, the cognitive abilities that were found to be critical for task performance depended on the search problem's complexity. Also, significant differences in task performance between the younger and the two older age groups were found on complex, but not on simple problems. Overall, the results from this study have implications for instructing older adults on Internet information seeking and for the design of Web sites.
Data Sonification for Users with Visual Impairment
Authors: Zhao Haixia , Plaisant Catherine , Shneiderman Ben , Lazar Jonathan
Published: May 2008

We describe the development and evaluation of a tool, iSonic, to assist users with visual impairment in exploring georeferenced data using coordinated maps and tables, augmented with nontextual sounds and speech output. Our in-depth case studies with 7 blind users during 42 hours of data collection, showed that iSonic enabled them to find facts and discover trends in georeferenced data, even in unfamiliar geographical contexts, without special devices. Our design was guided by an Action-by-Design-Component (ADC) framework, which was also applied to scatterplots to demonstrate its generalizability. Video and download is available at www.cs.umd.edu/hcil/iSonic/.
Compositional schedulability analysis for cyber-physical systems
Authors: Easwaran Arvind , Lee Insup
Published: May 2008

Cyber-physical systems (CPSs) are becoming all-pervasive, and due to increasing complexity they are designed using component-based approaches. Temporal constraints of such complex CPSs are then modeled using hierarchical scheduling frameworks. Therefore, there is a need to develop compositional schedulability analysis techniques for such CPSs. In this essay, we describe one such CPS present in air-crafts. We also discuss the hierarchical frameworks that are found in these systems, and highlight shortcomings of existing techniques in analyzing them.
Cyber-physical systems in industrial process control
Authors: Wang Yunbo , Vuran Mehmet C. , Goddard Steve
Published: May 2008

As a large-scale interconnected system of heterogeneous components integrating computation with physical processes, Cyber-Physical Systems (CPS) can greatly improve the efficiency of industrial process control systems. However, the inherent heterogeneity and the close integration of different components pose new challenges, which can only be solved by a new unifying network and control theory. This article investigates such challenges in industrial process control and proposes a CPS architecture for future research. Some open research issues are also suggested.
Human in the loop
Authors: Wood Anthony D. , Stankovic John A.
Published: May 2008

Emerging research in cyber-physical systems (CPSs) often leaves out a key component--the ordinary user. We present requirements for Immersive CPSs, in which people interact with their local environments, and describe a design for distributed data stream creation and sharing.
A prototype architecture for cyber-physical systems
Authors: Tan Ying , Goddard Steve , Pérez Lance C.
Published: May 2008

Cyber-Physical Systems (CPS) is an exciting emerging research area that has drawn the attention of many researchers. Although the question of "What is a CPS?" remains open, widely recognized and accepted attributes of a CPS include timeliness, distributed, reliability, fault-tolerance, security, scalability and autonomous. In this paper, a CPS definition is given and a prototype architecture is proposed. It is argued that this architecture captures the essential attributes of a CPS and lead to identification of many research challenges.
Spatial organization of neurons in the dorsal motor nucleus of the vagus synapsing with intragastric cholinergic and nitric oxide/VIP neurons in the rat
Authors: Zhou Shi-Yi , Lu Yuan-Xu , Yao HongRen , Owyang Chung
Published: May 2008

The dorsal motor nucleus of the vagus (DMV) contains preganglionic neurons that control gastric motility and secretion. Stimulation of different parts of the DMV results in a decrease or an increase in gastric motor activities, suggesting a spatial organization of vagal preganglionic neurons in the DMV. Little is known about how these preganglionic neurons in the DMV synapse with different groups of intragastric motor neurons to mediate contraction or relaxation of the stomach. We used pharmacological and immunohistochemical methods to characterize intragastric neural pathways involved in mediating gastric contraction and relaxation in rats. Microinjections of l-glutamate (l-Glu) into the rostral or caudal DMV produced gastric contraction and relaxation, respectively, in a dose-related manner. Intravenous infusion of hexamethonium blocked these actions, suggesting mediation via preganglionic cholinergic pathways. Atropine inhibited gastric contraction by 85.5 ± 4.5%. Gastric relaxation was reduced by intravenous administration of NG-nitro-l-arginine methyl ester (l-NAME; 52.5 ± 11.9%) or VIP antagonist (56.3 ± 14.9%). Combined administration of l-NAME and VIP antagonist inhibited gastric relaxation evoked by l-Glu (87.8 ± 4.3%). Immunohistochemical studies demonstrated choline acetyltransferase immunoreactivity in response to l-Glu microinjection into the rostral DMV in 88% of c-Fos-positive intragastric myenteric neurons. Microinjection of l-Glu into the caudal DMV evoked expression of nitric oxide (NO) synthase and VIP immunoreactivity in 81 and 39%, respectively, of all c-Fos-positive intragastric myenteric neurons. These data indicate spatial organization of the DMV. Depending on the location, microinjection of l-Glu into the DMV may stimulate intragastric myenteric cholinergic neurons or NO/VIP neurons to mediate gastric contraction and relaxation.
BRAF Silencing by Short Hairpin RNA or Chemical Blockade by PLX4032 Leads to Different Responses in Melanoma and Thyroid Carcinoma Cells
Authors: Sala Elisa , Mologni Luca , Truffa Silvia , Gaetano Carlo , Bollag Gideon E. , Gambacorti-Passerini Carlo
Published: May 2008

BRAF-activating mutations have been reported in several types of cancer, including melanoma (∼70% of cases), thyroid (30-70%), ovarian (15-30%), and colorectal cancer (5-20%). Mutant BRAF has constitutive kinase activity and causes hyperactivation of the mitogen-activated protein kinase pathway. BRAF silencing induces regression of melanoma xenografts, indicating the essential role of BRAF for cell survival. We set up an inducible short hairpin RNA system to compare the role of oncogenic BRAF in thyroid carcinoma versus melanoma cells. Although BRAF knockdown led to apoptosis in the melanoma cell line A375, the anaplastic thyroid carcinoma cell ARO underwent growth arrest upon silencing, with little or no cell death. Reexpression of the thyroid differentiation marker, sodium iodide symporter, was induced after long-term silencing. The different outcome of BRAF down-regulation in the two cell lines was associated with an opposite regulation of p21CIP1/WAF1 expression levels in response to the block of the BRAF mitogenic signal. These results were confirmed using a specific BRAF small-molecule inhibitor, PLX4032. Restoration of p21CIP1/WAF1 expression rescued melanoma cells from death. Altogether, our data indicate that oncogenic BRAF inhibition can have a different effect on cell fate depending on the cellular type. Furthermore, we suggest that a BRAF-independent mechanism of cell survival exists in anaplastic thyroid cancer cells. (Mol Cancer Res 2008;6(5):751–9)
Do Dual Tasks Have an Added Value Over Single Tasks for Balance Assessment in Fall Prevention Programs? A Mini-Review
Authors: Zijlstra A. , Ufkes T. , Skelton D.A. , Lundin-Olsson L. , Zijlstra W.
Published: May 2008

Background: The Prevention of Falls Network Europe (ProFaNE) aims to bring together European researchers and clinicians to focus on the development of effective falls prevention programs for older people. One of the objectives is to identify suitable balance assessment tools. Assessment procedures that combine a balance task with a cognitive task may be relevant since part of all falls occurs during dual-task performance of walking or other balance activities. Objective: To evaluate whether dual-task balance assessments are more sensitive than single balance tasks in predicting falls and detecting changes in balance performance after fall interventions. Methods: A systematic literature search was performed in the databases PubMed, EMBASE, CINAHL, AMED, PsycINFO and Cochrane. Articles were selected according to the following inclusion criteria: (1) population: older adults (mean age ≧65 years), (2) assessment tool: dual task combining gait or other balance task with a cognitive task, (3) design: prospective or retrospective data collection of falls, or intervention study. Analysis of papers focused on measures of predictive ability or sensitivity-to-change for both tasks during dual-task performance as well as for the single balance and cognitive task. Results: Out of 114 dual-task studies in older people, 19 articles matched the inclusion criteria. Fourteen studies had sample sizes of 60 subjects or less; the studied populations, task combinations as well as other methodological aspects varied. None of the articles reported the same statistical measures for both tasks during dual-task performance as well as single balance and cognitive task. In two studies with prospective data collection of falls, higher odds ratios were found for the dual compared to the single balance task. Conclusions: Upon the available literature, conclusions for an added value of dual balance tasks for fall prediction or assessing fall intervention effects cannot be made due to incomplete comparisons of single and dual balance tasks. Nevertheless, two studies do provide an indication that dual balance tasks may have added value for fall prediction.
Pathogenesis of Dyspepsia
Authors: Mimidis Kostas , Tack Jan
Published: May 2008

Functional dyspepsia (FD) is a highly prevalent and heterogeneous disorder. Although recent studies have investigated various pathophysiological mechanisms, the pathogenesis of FD remains obscure. Pathophysiological mechanisms currently proposed to be involved in FD symptom generation include delayed gastric emptying, impaired gastric accommodation to a meal, hypersensitivity to gastric distention, altered duodenal sensitivity to lipids or acid, abnormal duodenojejunal motility, and others. Pathogenetic factors implicated in the occurrence of FD include genetic susceptibility, Helicobacter pylori status, acute gastrointestinal infections and psychosocial factors. The present article provides an overview of pathogenetic factors, pathophysiologic mechanisms and their potential roles in FD.
The Rome III Classification of Dyspepsia: Will It Help Research?
Authors: Talley Nicholas J. , Ruff Kevin , Jiang Xuan , Jung Hye Kyung
Published: May 2008

A major change in the Rome III criteria relates to the condition previously called functional dyspepsia (FD). Rome I and Rome II defined FD as pain or discomfort centered in the upper abdomen without a definite structural or biochemical explanation. The condition was further sub-classified into ulcer-like or dysmotility-like dyspepsia. However, subsequent studies failed to show that single-symptoms are present in the vast majority of patients, and most symptoms failed to correlate with any physiological abnormalities. In Rome III, FD as a broad category was no longer considered useful in terms of research, but rather was defined by two new symptom entities, namely epigastric pain (epigastric pain syndrome) and meal-related symptoms (postprandial distress syndrome). We predict these changes will stimulate new research into the underlying pathophysiological disturbances, as well as impact the diagnosis and treatment of dyspepsia; the classification should advance the field, and we review the challenges ahead.
Dyspepsia and Helicobacter pylori
Authors: Selgrad Michael , Kandulski Arne , Malfertheiner Peter
Published: May 2008

Dyspepsia is defined as a chronic or recurrent pain centered in the upper abdomen. Dyspeptic symptoms have a high prevalence in the population and represent a common reason for patients to see a primary care physician. Therefore, dyspepsia displays a major health care burden and produces high socioeconomic costs. The etiology of dyspeptic symptoms is various and complex and has opened a wide spectrum of putative mechanisms. In a subset of patients dyspeptic symptoms are likely to originate from Helicobacter pylori infection. Population-based studies have demonstrated that H. pylori is detected more frequently in dyspeptic patients compared to controls. H. pylori eradication therapy gives modest but significant benefit in non-ulcer dyspepsia and leads to long-term symptom improvement. It also reduces the risk of developing peptic ulcer disease and other H. pylori-related gastric pathologies (i.e. atrophic gastritis, gastric cancer). The main therapeutic strategy for managing dyspepsia in patients under the age of 45 years is ‘test and treat’. H. pylori eradication is recommended in patients with dyspepsia and no other gastroduodenal abnormalities than H. pylori induced gastritis. In patients presenting with alarm features a prompt upper endoscopy should be performed to exclude peptic ulcer disease, esophageal and gastric malignancies or other more rare upper gastrointestinal diseases.
Failed Therapy and Directions for the Future in Dyspepsia
Authors: Holtmann Gerald , Gapasin Judith
Published: May 2008

Functional gastrointestinal disorders including functional dyspepsia are highly prevalent. Their clinical course is benign without disease-associated mortality. On the other hand, the impact can be substantial for the affected patients with regard to the decrease of quality of life, and for society with regard to the economical implications. Functional dyspepsia is a clinical syndrome with various underlying pathophysiologies. Thus, it is understandable that there is no single cure available. Reassurance by ruling out relevant differential diagnoses, explanation, and general advice with regard to the underlying causes and dietary and life-style measures are important components of the management of these patients. Well established medical treatments include Helicobacter pylori eradication, acid inhibitory agents and prokinetics. The overall gain over placebo ranges from less than 5% for H. pylori eradication to 15% for antisecretory agents and prokinetics. Thus, even considering a substantial proportion of patients with spontaneous remissions (usually addressed as placebo response in clinical trials), there are 20 to 40% of patients who do not respond properly to these measures. In these patients, other treatment modalities need to be considered. These second- or third-line measures include herbal medicines and psychotropic agents. Some of the herbal preparations have been well studied in controlled clinical trials with sufficient scientific evidence to assume efficacy. Psychotropic drugs on the other hand have, as yet, not been specifically tested in functional dyspepsia. Medications such as clonidine, buspirone or octreotide can be helpful in few selected patients. However, a very careful assessment of potential risks and benefits needs to be undertaken on a case-by-case basis. Other evidence-based measures include psychological interventions such as psychotherapy and hypnotherapy.
Symptomatic Response to Blocked and Unblocked Pentagastrin Stimulation in Functional Dyspepsia
Authors: Madsen Lone Galmstrup , Bytzer Peter
Published: May 2008

Background: The role of acid in functional dyspepsia is controversial and drug treatment trials indicate that only a subset of patients has acid-related symptoms. A novel single-subject trial design, the Random Starting Day trial (RSD trial), was developed to identify acid-related symptoms. We hypothesized that RSD trial responders and non-responders would react differently to gastric acid stimulation. Development of epigastric pain was expected in RSD trial responders after pentagastrin stimulation during placebo treatment, but not during omeprazole treatment. In non-responders, epigastric pain was expected not to be influenced by gastric acid stimulation or type of treatment. Methods: Nineteen patients were evaluated. Symptomatic response to pentagastrin (6 µg/kg) was assessed twice in each patient following placebo and omeprazole (40 mg bid) treatment in a randomized, double-blind, cross-over design. Epigastric pain was assessed every 15 for 90 min after stimulation using a 5-graded Likert scale and a VAS scale. A positive acid provocation test was defined as an increase of the Likert score of epigastric pain by at least one grade after pentagastrin stimulation during placebo treatment but not during omeprazole treatment. Results: The acid provocation test was positive in 43% (3/7) of responders compared to only 17% (2/12) non-responders. VAS-score changes showed trends towards a more pronounced symptom reduction during omeprazole treatment in responders compared to non-responders. Conclusion: Patients identified as having acid-related dyspepsia more often developed epigastric pain following acid stimulation during placebo and not during omeprazole treatment. Due to the low sample size the difference was not considered significant.
Comparison of Bare-Metal and Sirolimus- or Paclitaxel-Eluting Stents for Aorto-Ostial Coronary Disease
Authors: Barlis Peter , Kaplan Sahin , Dimopoulos Konstantinos , Ferrante Giuseppe , Di Mario Carlo
Published: May 2008

Objectives: Aorto-ostial lesions (AOL) are technically challenging, given their greater propensity to be calcific and associated with elastic recoil compared to non-ostial lesions. This study set out to assess angiographic and clinical outcomes in patients with AOL treated using either paclitaxel-eluting stents (PES) or sirolimus-eluting stents (SES) compared to bare-metal stent (BMS) implantation. Methods: We retrospectively identified 175 consecutive patients with 175 AOL involving the left main, right coronary artery or bypass graft. PES, SES and BMS were implanted in 69, 50 and 56 patients, respectively. Results: Angiographic and procedural success was 100 and 97.1% for PES, 100 and 94% for SES, and 100 and 94.6% for BMS, respectively (p not significant). At 12 months, the rates of target lesion (8.7% for PES, 4.0% for SES) and target vessel revascularization (3.0% for PES, 8.0% for SES) were significantly lower in the drug-eluting stent group compared to BMS (32.1 and 35.7%, respectively). There was no difference in the rate of death/MI in the BMS versus drug-eluting stent groups (5.4 vs. 2.4%, p = 0.32). Conclusions: In the treatment of AOL, drug-eluting stents reduce the need for repeat revascularization at 12 month follow-up compared to BMS, with no difference in mortality or MI rate.
Local Delivery of 17-Beta-Estradiol Modulates Collagen Content in Coronary Porcine Arteries after PTCA and Stent Implantation
Authors: Geraldes Pedro , Geoffroy Pascale , Cloutier Isabelle , Sirois Martin G. , Tanguay Jean-François
Published: May 2008

Background: Percutaneous transluminal coronary angioplasty (PTCA) and stent implantation are associated with intimal hyperplasia and extracellular matrix (ECM) accumulation, resulting in restenosis. We showed that local delivery of 17-beta-estradiol (17βE) reduced restenosis following PTCA and stent implantation by 47 and 23%, respectively. Because estrogens decreased type I and type III collagen synthesis in vitro, we hypothesized that local delivery of 17βE may influence intimal hyperplasia formation by modulating ECM expression. Methods: Porcine coronary arteries underwent PTCA or stenting and were randomly assigned to 17βE or placebo. After 28 days, animals were sacrificed for histology and collagen type I and III content analysis. Results: Both collagen subtypes increased in the media by 1.7 to 2.6-fold after PTCA and by 15.7 to 16.1-fold after stenting, as compared to PTCA segments. In the neointima, the ratio of collagen type III to type I was 2.7 in stented arteries and only 0.3 in PTCA arteries. In the neointima of 17βE-treated animals, collagen type I (but not type III) content upregulation was limited by 53% after PTCA and by 74% after stenting. Conclusion: Local delivery of 17βE reduces restenosis, in part by decreasing the density of collagen type I in the neointima in PTCA and stented arteries.
Effects of Insulin on Endothelial and Contractile Function of Subcutaneous Small Resistance Arteries of Hypertensive and Diabetic Patients
Authors: De Ciuceis Carolina , Rizzoni Damiano , Porteri Enzo , Boari Gianluca E.M. , Zani Francesca , Miclini Marco , Tiberio Guido A.M. , Giulini Stefano M. , Paiardi Silvia , Rizzardi Nicola , Platto Caterina , Agabiti-Rosei Enrico
Published: May 2008

The effect of insulin on the vasoconstriction induced by norepinephrine is at present controversial. We have previously demonstrated that high-concentration insulin may induce an increased reactivity to norepinephrine in mesenteric small resistance arteries of spontaneously hypertensive rats. The aim of the present study was to evaluate the effects of low- and high-concentration insulin on the concentration-response curves to norepinephrine and acetylcholine in subcutaneous small resistance arteries of hypertensive and diabetic patients. Twelve normotensive subjects (NT), 11 patients with essential hypertension (EH), 8 patients with non-insulin-dependent diabetes mellitus (NIDDM), and 8 patients with both EH and NIDDM (EH + NIDDM) were included in the study. Subcutaneous small resistance arteries were dissected and mounted on an isometric myograph. Concentration-response curves to norepinephrine (from 10–8 to 10–5 mol/l) and acetylcholine (from 10–9 to 10–5 mol/l) were performed in the presence or absence of insulin 715 pmol/l (low concentration) and 715 nmol/l (high concentration). A significant reduction in the contractile response to norepinephrine was observed in NT after preincubation of the vessels with both low- and high-concentration insulin. No reduction was observed in NIDDM and EH + NIDDM, while a significant decrease was obtained in EH with high-concentration insulin. Moreover, a significant difference in reduction in contractile response at maximal concentration of norepinephrine in the presence of low-concentration insulin was observed in NT compared to EH (p = 0.03), NIDDM (p = 0.02), and EH + NIDDM (p = 0.05), whereas no difference was observed with high-concentration insulin. No differences in the concentration-response curves to acetylcholine before or after precontraction with either low- or high-concentration insulin were observed in any group. In conclusion, insulin at low (physiological) concentrations seems to induce a decreased reactivity to norepinephrine in subcutaneous small resistance arteries of NT, but this effect was lost in EH, NIDDM and EH + NIDDM. This effect does not seem to involve acetylcholine-stimulated nitric oxide release.
Asthma and Sinusitis: Association and Implication
Authors: Matsuno Osamu , Ono Emiko , Takenaka Ryuichi , Okubo Toshiyuki , Takatani Keiko , Ueno Takuya , Nishitake Takahiro , Hiroshige Shigeo , Sawabe Toshiyuki , Matsumoto Tetsuro , Miyazaki Eishi , Kumamoto Toshihide
Published: May 2008

Background: Sinusitis occurs frequently in asthmatic patients. Epidemiologic data on sinusitis and lower airway disease must be evaluated with caution because they are based mostly on symptoms and do not include nasal endoscopic or computed tomography (CT) findings. Clinical support and evidence for this association are lacking. We evaluated the impact of sinusitis on lower airway disease in patients with well-characterized asthma. Methods: Subjects (n = 188) completed a questionnaire designed to provide information about their signs and symptoms related to asthma, allergic rhinitis (AR) and sinus disease. Patients (n = 104) were divided into four groups based on the presence or absence of sinusitis and/or AR. Clinical findings were compared in asthma patients with and without diagnosed sinusitis, by an otorhinolaryngologist or based on sinus CT findings. Results: The prevalence of sinusitis in patients with asthma was 36.7%. Sinus CT scan abnormalities were detected in 66.3% of patients with asthma. The scans revealed abnormal opacity in 17.9% of asthmatic patients without a history of sinusitis. There was a significant correlation between the rate of asthma severity and sinus morphologic abnormalities in patients with and without sinusitis. In adult-onset asthma (≧16 years old), sinusitis frequently preceded asthma, whereas in non-adult-onset asthma (<16 years old) it preceded sinusitis. The complication rate of sinusitis in asthmatic patients was significantly higher in adult-onset asthma than in non-adult-onset asthma. Conclusions: Our findings suggest that bronchial asthma is closely related to sinusitis and the onset age of asthma is important when considering allergic disease frequency. Whether sinus disease directly affects the intensity of bronchial inflammation remains to be elucidated.
Metal Concentrations in Plasma and Cerebrospinal Fluid in Patients with Alzheimer’s Disease
Authors: Gerhardsson Lars , Lundh Thomas , Minthon Lennart , Londos Elisabet
Published: May 2008

Background/Aims: The homeostasis of essential metals such as copper, iron, selenium and zinc may be altered in the brain of subjects with Alzheimer’s disease (AD). Methods: Concentrations of metals (magnesium, calcium, vanadium, manganese, iron, cobalt, nickel, copper, zinc, selenium, rubidium, strontium, molybdenum, cadmium, tin, antimony, cesium, mercury and lead) were determined in plasma and cerebrospinal fluid (CSF) by inductively coupled plasma mass spectrometry in 173 patients with AD and in 87 patients with the combination of AD and minor vascular components (AD + vasc). Comparison was made with 54 healthy controls. Results: The plasma concentrations of manganese and total mercury were significantly higher in subjects with AD (p < 0.001) and AD + vasc (p ≤ 0.013) than in controls. In CSF, however, the concentrations of vanadium, manganese, rubidium, antimony, cesium and lead were significantly lower among subjects with AD (p ≤ 0.010) and AD + vasc (p ≤ 0.047) than in controls. Strong positive correlations were noted between plasma Cs versus CSF Cs in subjects with AD (rs = 0.50; p < 0.001), and AD + vasc (rs = 0.68; p < 0.001). Conclusion: Besides the raised plasma mercury concentrations, no consistent metal pattern in plasma or CSF was observed in patients with AD.
Acute Abdomen from Chylous Peritonitis: A Surgical Diagnosis
Authors: Vettoretto N. , Odeh M. , Romessis M. , Pettinato G. , Taglietti L. , Giovanetti M.
Published: May 2008

Acute accumulation of chyle in the peritoneal cavity is a rare event (less than 100 cases are described in the literature) and is to be distinguished from chylous ascites, which is characteristically chronic. It is frequently idiopathic, and diagnosis is usually made at laparotomy, whenever signs of acute peritonitis impose it. Peritoneal toilette and drainage are the only treatment required, and the prognosis is excellent. We describe the case of a 69-year-old man who underwent emergency surgery for acute peritonitis. Approximately 0.5 liters of chyle were found free in the peritoneal cavity at laparoscopic exploration, without any important underlying pathological condition apart from a blood vessel congestion in the bowel resembling angiomatosis. Laparotomic conversion, peritoneal toilette and drainage, with postoperative low-fat diet, were the pursued treatments. Two years after discharge, chemistry and clinics are normal, without evidence of associated disease or recurrence.
Urinary Concentration Defects and Mechanisms Underlying Nephronophthisis
Authors: Krishnan Rajesh , Eley Lorraine , Sayer John A.
Published: May 2008

The cystic kidney disease nephronophthisis (NPHP) is the commonest genetic cause of end-stage renal failure in young people and children. Histologically the disease is characterized by interstitial fibrosis, tubular atrophy with corticomedullary cyst development and disruption of the tubular basement membrane. Affected children present with polydipsia and polyuria, secondary to a urinary concentration defect, before these structural changes develop. Recently, molecular genetic advances have identified several genes mutated in NPHP, providing novel insights into its pathophysiology for the first time in decades. Here we review the normal physiological mechanisms of urinary concentration and explain, in the context of recent discoveries, the possible mechanisms underlying urinary concentration defects in patients with NPHP. The pattern of a ciliary and adherens junction subcellular localization of nephrocystin proteins is discussed. Recent animal models of cystic kidney disease and treatment with vasopressin V2 receptor antagonists are reviewed and a hypothesis regarding urinary concentration defects in NPHP is proposed. Understanding the cellular mechanisms underlying NPHP and other cystic kidney diseases will provide the rationale for therapeutic interventions in this disease. Early urinary concentration defects provide both a clue to clinical diagnosis of NPHP and potential therapeutic targets for pharmacological treatment of this condition.
Aging, Circadian Weight Change, and Nocturia
Authors: Kaye Michael
Published: May 2008

Background: Normal young individuals excrete more sodium in their urine during the day than overnight, but the reverse occurs in older individuals with nocturia. The reason is unknown. Methods: First, a self-study was performed, determining the relation between morning and night weight change as an index of volume expansion. This was followed for 1 year and modified, in separate experiments, by assessing either a diuretic (furosemide 40 mg) or recumbency. Weight and in some instances ankle circumference were measured, and day and night urines collected. Second, a community study of 102 individuals was done, measuring circadian weight change and nocturia for 3 days in each subject. Third, measurement of day and night urine electrolytes and weight change was performed in 10 non-nocturics and 12 matched nocturics (age ≧60 years). Results: Salt and water retention occurs during the day and natriuresis and diuresis overnight. Nocturia occurs when weight gain is greater. It is prevented by an afternoon diuretic or daytime recumbency. Conclusions: Idiopathic nocturia is due to daytime volume expansion associated with the upright position. It is hypothesized that this is caused by sodium retention during the day mediated by renal nerve sympathetic activity which together with angiotensin II acts on the kidney to increase tubular sodium reabsorption either directly or by reducing daytime glomerular filtration rate.