bluuebunny/crossref_metadata_2025 huggingface dataset:
Global Phase Portraits of Kukles Differential Systems with Homogeneous Polynomial Nonlinearities of Degree 6 Having a Center and Their Small Limit Cycles
Authors: Llibre Jaume , da Silva Maurício Fronza
Published: April 2016

We provide the nine topological global phase portraits in the Poincaré disk of the family of the centers of Kukles polynomial differential systems of the form [Formula: see text] [Formula: see text] where [Formula: see text] and [Formula: see text] are real parameters satisfying [Formula: see text] Using averaging theory up to sixth order we determine the number of limit cycles which bifurcate from the origin when we perturb this system first inside the class of all homogeneous polynomial differential systems of degree [Formula: see text] and second inside the class of all polynomial differential systems of degree [Formula: see text]
DYNAMICAL ANALYSES USING VISIBILITIES IN FINANCIAL MARKETS
Authors: MIN SEUNGSIK , LIM KYUSEONG , CHANG KI-HO , PARK IL-HWAN , KIM KYUNGSIK
Published: April 2016

In this paper, the network metrics are studied in a time series of the KOSPI and the KOSDAQ indices converting by the visibility graph algorithm. The degree distributions for the KOSPI and the KOSDAQ are proportional to a power law rather than the Poisson distribution. Since we mainly simulate and analyze the network metrics from the nodes and its links, our result cannot be found unambiguously to have universal and characteristic properties of statistical quantities via financial networks. Particularly, these topological properties may improve by implementing the statistical method and its technique from altered data of financial networks.
Ratliff–Rush closures and linear growth of primary decompositions of ideals
Authors: Sedghi Monireh
Published: April 2016

Let [Formula: see text] be a commutative Noetherian ring, [Formula: see text] a nonzero finitely generated [Formula: see text]-module and [Formula: see text] an ideal of [Formula: see text]. First purpose of this paper is to show that the sequences [Formula: see text] and [Formula: see text], [Formula: see text] of associated prime ideals are increasing and eventually stabilize. This extends the main result of Mirbagheri and Ratliff [On the relevant transform and the relevant component of an ideal, J. Algebra 111 (1987) 507–519, Theorem 3.1]. In addition, a characterization concerning the set [Formula: see text] is included. A second purpose of this paper is to prove that [Formula: see text] has linear growth primary decompositions for Ratliff–Rush closures with respect to [Formula: see text], that is, there exists a positive integer [Formula: see text] such that for every positive integer [Formula: see text], there exists a minimal primary decomposition [Formula: see text] in [Formula: see text] with [Formula: see text], for all [Formula: see text].
Multiplicative canonical ideals of ring extensions
Authors: Tchamna Simplice
Published: April 2016

We study properties of multiplicative canonical (m-canonical) ideals of ring extensions. Let [Formula: see text] be a ring extension. A nonzero [Formula: see text]-regular ideal [Formula: see text] of [Formula: see text] is called an m-canonical ideal of the extension [Formula: see text] if [Formula: see text] for all [Formula: see text]-regular ideal [Formula: see text] of [Formula: see text]. We study m-canonical ideals for pullback diagrams, and we use the notion of m-canonical ideal to characterize Prüfer extensions.
EFFECT OF LOADING RATE ON VISCOELASTIC PROPERTIES AND LOCAL MECHANICAL HETEROGENEITY OF FRESHLY ISOLATED MUSCLE FIBER BUNDLES SUBJECTED TO UNIAXIAL STRETCHING
Authors: TAMURA ATSUTAKA , HAYASHI SADAYUKI , MATSUMOTO TAKEO
Published: April 2016

To investigate the effect of viscoelastic behavior on instantaneous muscle mechanics, the passive mechanical properties for the range of physiologically relevant rates should be clarified. Therefore, a series of uniaxial extension tests were conducted at various stretching rates using the muscle fiber bundles, which contained extracellular matrix (ECM) and interfibrillar microstructural components. We revealed that the tensile strength is strain rate-sensitive over the examined range, i.e., the muscle fiber bundle failed at 109[Formula: see text][Formula: see text][Formula: see text]34, 122[Formula: see text][Formula: see text][Formula: see text]44, and 179[Formula: see text][Formula: see text][Formula: see text]61[Formula: see text]kPa (mean[Formula: see text][Formula: see text][Formula: see text]SD) for strain rates of 0.02, 0.1, and 0.5[Formula: see text]s[Formula: see text], respectively. Moreover, we found that the applied stretch was not distributed uniformly even in relaxed conditions; the ratio between maximum and minimum local strains within a specimen was 2–3 on average during stretching and increased up to approximately four just before failure, indicating local mechanical heterogeneity along a fiber bundle and its exaggeration by stretching. Macroscopically, however, the tensile strain at failure was almost constant, [Formula: see text]50%. The local heterogeneity of muscle strain distribution can lead to unstable oscillation in a computational model. Thus, in addition to the intrinsic viscous effects of the muscle fiber itself, those of ECM and interfibrillar microstructural components should be considered in mathematical modeling of skeletal muscle.
A theoretical study on antioxidant activity of ferulic acid and its ester derivatives
Authors: Borgohain Romesh , Handique Jyotirekha G. , Guha Ankur Kanti , Pratihar Sanjay
Published: April 2016

Phenolic compounds play a very crucial role as antioxidant that can prevent various diseases caused by free radicals in human body. Although, lots of natural phenolic compounds having antioxidant activity are available nowadays, the modeling of compounds with naturally available phenolics as building blocks is very important in order to get enhanced antioxidant activity. In this study, Ferulic acid (FA), one natural phenolic acid present in coffee, apples, orange, etc., is taken as building block and its ester derivatives with different alkyl groups are subjected to measure the antioxidant activity by using density functional theory (DFT). Various parameters like bond dissociation enthalpy (BDE), vertical ionization potential (IP[Formula: see text]), reactivity descriptors, metal chelation ability, etc. are used to measure the antioxidant activity. All the parameters suggest that the ester derivatives are superior antioxidants to the parent FA. Since FA has been reported to be present as esters in many herbs and plants, hence our study provides a route to study the structure activity relationship of this class of natural phenolics with antioxidant activity.
Charge transfer complexes between 2-, 3- and 4-aminopyridines and some π-acceptors in the gas phase and in chloroform: DFT calculations
Authors: Wazzan Nuha Ahmed
Published: April 2016

This work reports density functional theory (DFT) calculations on the molecular structures, electronic distribution, and UV-Vis and IR spectroscopy analysis of charge transfer complexes between aminopyridines (APYs), namely 2-APY, 3-APY and 4-APY, as electron-donors and some [Formula: see text]-electron-acceptors, namely chloranil (CHL), tetracyanoethylene (TCNE) and picryl chloride (PC), formed in the gas phase at the B3LYP/6-31[Formula: see text]G(d,p) method/basis set, and in chloroform at the same method/basis set using PCM as solvation model. Good correspondence was generally obtained between the calculated parameters and the experimental ones.
Multi-Resolution MPS Method for Free Surface Flows
Authors: Tang Zhenyuan , Zhang Youlin , Wan Decheng
Published: April 2016

A multi-resolution moving particle semi-implicit (MPS) method is applied into two-dimensional (2D) free surface flows based on our in-house particle solver MLParticle-SJTU in the present work. Considering the effect of different size particles, both the influence radiuses of two adjacent particles are replaced by the arithmetic mean of their interaction radiuses. Then the modifications for kernel function of differential operator models are derived, respectively. In order to validate the present multi-resolution MPS method, two cases are carried out. Firstly, a hydrostatic case is performed. The results show that the contour of pressure field by multi-resolution MPS is quite in agreement with that by single resolution MPS. Especially, the multi-resolution MPS can still provide a relative smooth pressure together with the single resolution MPS in the vicinity of the interface between the high resolution and low resolution particles. For a long time simulation, the kinetic energy of particles by multi-resolution MPS can decrease quickly to the same level as that of single resolution MPS. In addition, a 2D dam breaking flow is simulated and the multi-resolution case can run stably during the whole simulation. The pressure by the multi-resolution MPS is in agreement with experimental data together with single resolution MPS. The contour of pressure field by the former is also similar to that by the later. Finally, the simulation by multi-resolution MPS is as accurate as the traditional MPS with fine particles distributed in the whole domain and the corresponding CPU time can be reduced.
Low dimensional supersymmetries in SUSY Chern–Simons systems and geometrical implications
Authors: Oikonomou V. K.
Published: April 2016

We study in detail the underlying graded geometric structure of abelian [Formula: see text] supersymmetric Chern–Simons theory in (2 + 1)-dimensions. This structure is an attribute of the hidden unbroken one-dimensional [Formula: see text] supersymmetries that the system also possesses. We establish the result that the geometric structures corresponding to the bosonic and to the fermionic sectors are equivalent fiber bundles over the (2 + 1)-dimensional manifold. Moreover, we find a geometrical answer to the question why some and not all of the fermionic sections are related to a [Formula: see text] supersymmetric algebra. Our findings are useful for the quantum theory of Chern–Simons vortices.
Conformal variations and quantum fluctuations in discrete gravity
Authors: Marzuoli Annalisa , Merzi Dario
Published: April 2016

After an overview of variational principles for discrete gravity, and on the basis of the approach to conformal transformations in a simplicial PL setting proposed by Luo and Glickenstein, we present at a heuristic level an improved scheme for addressing the gravitational (Euclidean) path integral and geometrodynamics.
Linear layouts of weakly triangulated graphs
Authors: Mukhopadhyay Asish , Rao S. V. , Pardeshi Sidharth , Gundlapalli Srinivas
Published: April 2016

A graph [Formula: see text] is said to be triangulated if it has no chordless cycles of length 4 or more. Such a graph is said to be rigid if, for a valid assignment of edge lengths, it has a unique linear layout and non-rigid otherwise. Damaschke [Point placement on the line by distance data, Discrete Appl. Math. 127(1) (2003) 53–62] showed how to compute all linear layouts of a triangulated graph, for a valid assignment of lengths to the edges of [Formula: see text]. In this paper, we extend this result to weakly triangulated graphs, resolving an open problem. A weakly triangulated graph can be constructively characterized by a peripheral ordering of its edges. The main contribution of this paper is to exploit such an edge order to identify the rigid and non-rigid components of [Formula: see text]. We first show that a weakly triangulated graph without articulation points has at most [Formula: see text] different linear layouts, where [Formula: see text] is the number of quadrilaterals (4-cycles) in [Formula: see text]. When [Formula: see text] has articulation points, the number of linear layouts is at most [Formula: see text], where [Formula: see text] is the number of nodes in the block tree of [Formula: see text] and [Formula: see text] is the total number of quadrilaterals over all the blocks. Finally, we propose an algorithm for computing a peripheral edge order of [Formula: see text] by exploiting an interesting connection between this problem and the problem of identifying a two-pair in [Formula: see text]. Using an [Formula: see text] time solution for the latter problem, we propose an [Formula: see text] time algorithm for computing its peripheral edge order, where [Formula: see text] and [Formula: see text] are respectively the number of edges and vertices of [Formula: see text]. For sparse graphs, the time complexity can be improved to [Formula: see text], using the concept of handles [R. B. Hayward, J. P. Spinrad and R. Sritharan, Improved algorithms for weakly chordal graphs, ACM Trans. Algorithms 3(2) (2007) 19pp].
(1 + n) sequential dissection of a rectangle into m-GONS, m ∈{3,5,6,7,8}
Authors: Boonklurb Ratinan , Sanguanlorsit Eakasit
Published: April 2016

This paper gives algorithms to dissect a rectangle sequentially into polygons that can be reassembled to a rectangle, which is similar to the initial rectangle, and [Formula: see text]-similar equilateral triangles or regular hexagons and also pentagons or heptagons or octagons with symmetry.
Nonrigid Registration of Pre-Procedural MRI and Intra-Procedural CT in CT-Guided Cryoablation of Lung Tumors to Improve Lung Tumor Conspicuity
Authors: Hata Nobuhiko , Tatli Servet , Yamada Atsushi , Olubiyi Olutayo , Silverman Stuart G.
Published: April 2016

To improve lung tumor conspicuity during CT-guided cryoablations, we used nonrigid image registrations to fuse pre-procedural MR images and intra-procedural CT images and determined which set of CT images taken at planning, targeting, and monitoring phases of the procedure provided the most accurate and fastest registrations. In 10 percutaneous CT-guided cryoablation procedures, MR images were registered with intra-procedural CT images using a nonrigid registration technique using an intensity-based approach with affine and B-Spline transformations. The time to complete the registration as well as the accuracy of the registration defined by Target Registration Error (TRE), Dice Similarity Coefficient (DSC), and Hausdorff Distance (HD) were measured to assess the performance of the registration. The least significant difference (LSD) method was used as a post-hoc analysis for comparing time and accuracy among planning, targeting, and monitoring phases. The mean TRE of the registration ranged from 6.26 (planning) to 10.31 (monitoring) mm. The mean DSC ranged from 83.86 (monitoring) to 89.22 (planning). The mean HD values ranged from 7.74 (targeting) to 12.20 (monitoring). Mean registration time ranged from 68.67 (monitoring) to 92.02 (planning) s. Using HD, registrations in either the planning or targeting phase were more accurate than in the monitoring phase. The registration was faster using monitoring images than using planning images. Nonrigid registration techniques can be used to fuse pre-procedural MR images with intra-procedural CT images with varying performance depending on the CT images taken at the different phases of the procedure. Therefore, caution should be taken in setting expectations on accuracies and speeds of registration depending on the phases of the CT-guided ablation procedures.
Foundations of Session Types and Behavioural Contracts
Authors: Hüttel Hans , Lanese Ivan , Vasconcelos Vasco T. , Caires Luís , Carbone Marco , Deniélou Pierre-Malo , Mostrous Dimitris , Padovani Luca , Ravara António , Tuosto Emilio , Vieira Hugo Torres , Zavattaro Gianluigi
Published: April 2016

Behavioural type systems, usually associated to concurrent or distributed computations, encompass concepts such as interfaces, communication protocols, and contracts, in addition to the traditional input/output operations. The behavioural type of a software component specifies its expected patterns of interaction using expressive type languages, so types can be used to determine automatically whether the component interacts correctly with other components. Two related important notions of behavioural types are those of session types and behavioural contracts. This article surveys the main accomplishments of the last 20 years within these two approaches.
Clinical Experience with 5-Aminosalicylate Preparations in Inflammatory Bowel Disease - A Review
Authors: Williams C.N.
Published: April 2016

The efficacy of 5-ASA tablets is around 65 co 70% in patients with active ulcerative colitis, whereas the efficacy of the rectal preparations approach 100% when the treatment is for active distal disease. When there is more extensive left sided colonic disease, the efficacy of 5-ASA rectal preparations is not as high, but it is still much improved over that seen with oral 5-ASA preparations. There is no data available for total colonic disease of either ulcerative colitis or Crohn's disease. There is no controlled maintenance data available for Crohn's disease using 5-ASA preparations and no controlled or comparison data available for rectal preparations in Crohn's disease. There are no controlled dose-response studies of 5-ASA in patients with Crohn's disease. Thus, the most "therapeutic" dose is not known. The author's anecdotal evidence reports char patients with Crohn's disease affecting the rectum or left colon respond poorly to 5-ASA enemas. However. with continued use of more than six weeks at least a 50 to 60% respone is seen. In contrast, virtually all patients with ulcerative proctitis respond by six weeks and all are controlled by 10 to 12 weeks. When oral 5-ASA is compared with conventional oral sulfasalazine therapy, the efficacy is comparable. However, with 5-ASA the incidence of side effects is considerably lower; the number of patients discontinuing therapy is less; patient compliance is better, especially for the long term; dosage increase following inadequate action is more readily possible; and bacterial activation of the drug given is not necessary.
Disorders of Mineral and Bone Metabolism in Patients with Crohn's Disease
Authors: Westarp C. Von , Thomson A.B.R. , Overton T.R. , Rogers R.M. , Hodges P.E. , Fornasier V.L. , Crockford P.M.
Published: April 2016

Crohn's disease is known to produce malabsorption of calcium and vitamin D which affect the skeleton. A variety of techniques were used to assess the prevalence of mineral and bone abnormalities in 53 consecutive patients with Crohn's disease. Twenty healthy controls were compared with 28 men and 25 women with Crohn's disease. In males, the mean corrected serum calcium concentration was elevated, the mean winter plasma 25-hydroxyvitamin D was low, as was the bone volume on biopsy and the fractional absorption of {7Ca. In females, the corrected serum calcium was also higher than in controls, as was the serum alkaline phosphatase activity. The female patients had significant decreases in both summer and winter plasma vitamin D levels, metacarpal cortical thickness and fractional absorption of 47Ca. The disturbances in bone and mineral metabolism were generally mild and were not associated with use of glucocorticosteroids but were more severe in patients with a history of bowel resection. Thus, patients with Crohn's disease are at risk of developing metabolic bone disease and consideration should be given for an assessment of the skeleton in patients with Crohn's disease. especially in women and in patients with previous ilea! resection. A battery of tests may be needed to exclude the diagnosis of metabolic bone disease but a 25-hydroxyvitamin D assay and hand x·rays using industrial grade film are recommended as a valuable preliminary assessment.
Granulomatous Hepatitis in Association with Fever and a Palmar Rash
Authors: Leddin Desmond J , Barrowman James A
Published: April 2016

Secondary syphilis may present without the classical features of the disease and should be considered in patients acutely ill with abnormal liver function tests and a nonspecific pattern on liver biopsy. Secondary syphilis may present in association with granulomatous hepatitis and serological testing should be performed if the etiology of the hepatic granulomas is unclear. While the finding of a disproportionate elevation of alkaline phosphatase relative to serum bilirubin may be a useful pointer towards the diagnosis this pattern is not specific and not consistently observed. The definitive answer to the question of whether syphilitic hepatitis exists awaits the development of comprehensive rests to exclude viral pathogens.
Candida Esophagitis in a Male Homosexual with Defective Neutrophil Function. A 'Pseudo-AIDS' Syndrome
Authors: Noble Michael A , Whittaker J Scott , Mangal Anil K , Carter Cedric J , Freeman Hugh J
Published: April 2016

36-year-old male homosexual presented with a prolonged history of odynophagia. Esophageal candidiasis was suspected at endoscopy and confirmed by biopsy ane cultures. Investigations demonstrated no evidence for underlying human immunodeficiency virus (HIV) infection hy either ELISA assay or Wes1ern Blot technique, and lymphocyte helper: supressor ratios were normal. A specific serum-dependent factor that inhibited the candidacidal capability of his neutrophils, as well as those of volunteer controls, was detected. This inhibitor disappeared after treatment of the candidal infection. Severe and extensive esophagitis is not always indicative of an underlying infection with HIV in homosexual mnles. Clinical criteria alone should not be used to establish the diagnosis of AIDS, even in patients from recognized high risk categories.
Injection Therapy for Nonvariceal Gastrointestinal Bleeding
Authors: Kortan Paul
Published: April 2016

Gastrointestinal hemorrhage is a common and serious problem - its average mortality of 10% has changed little over the past 40 years. In 80% of patients the bleeding stops spontaneously. In patients with continuous or recurrent bleeding (20%), mortality and morbidity are high, and emergency surgery is often required, which has a higher mortality than the same operation performed electively. Successful therapeutic endoscopic intervention in this high risk group is necessary to improve outcome. For injection treatment of nonvariceal bleeding lesions, the author has been using the Soehendra method (1:10,000 adrenaline and polidocanol) with success in 90% of actively bleeding patients. Three controlled trials of endoscopic sclerosis in bleeding peptic ulcer disease showed decreased blood transfusions, surgery and hospital stay, but did not find any significant difference in mortality. The ideal solution and the usefulness of additional therapy are questions which must be addressed via prospective controlled trials of a large number of patients.
Primary Sclerosing Cholangitis and Sarcoidosis. Case Report and Review of the Literature
Authors: Schep Gerry N , Scully Linda J
Published: April 2016

A 43-year-old man with longstanding ulcerative colitis developed primary sclerosing cholangitis established by cholangiography and liver biopsy. Within one year of the diagnosis of primary sclerosing cholangitis, pulmonary sarcoidosis developed, proven by chest x-ray and transbronchial biopsy. The sarcoidosis initially presented with systemic systems rather than dyspnea. The relationship between primary sclerosing cholangitis, sarcoidosis and the symptomatology are discussed. Concomitant primary sclerosing cholangitis and sarcoidosis may be more common than previously anticipated and could be a further manifestation of disordered immune regulation.
Clinical Efficacy of Oral Mesalazine in Crohn’s Disease
Authors: Maier Karlernst , Frick Hans-Jurgen , Von Gaisberg Ulrich , Teufel Thorsten , Klotz Ulrich
Published: April 2016

A randomized controlled trial was performed to evaluate in Crohn's disease the clinical efficacy and safety of a higher dose of a new slow-release preparation of mesalazine (500 mg tablets). Twenty-four patients created with 3 g mesalazine/day were compared with 26 patients treated with sulfasalazine (3 g/day) and methylprednisolone (initially 40 mg). All patients had active Crohn's disease diagnosed by endoscopy, sonography and radiology. Patients were characterized before entry into the study and at two, four, eight and 12 weeks of treatment by activity indices according to Best and van Hees, as well as by erythrocyte sedimentation rate, thrombocyte count, Broca index and serum albumin. All clinical and laboratory parameters were well matched for the two groups of patients. During treatment with mesalazine and sulfasalazine/ methylprednisolone, clinical remission could be observed in 20 of 24 patients (83%) and 23 of 26 patients (88%), respectively. There was no difference between the two groups except for a slightly higher increase of the Broca index in the combined treatment group. Side effects were reported in three (12.5%) and six (23%) patients treated with mesalazine and sulfasalazine/methylprednisolone, respectively. In conclusion, oral mesalazine at a dose of 3 g/day was effective in active Crohn's disease and was well tolerated by the patients.
Adenotonsillar Hypertrophy as a Cause of Failure to Thrive
Authors: Sheehan Ann G , Scott R Brent , Machida Helen M
Published: April 2016

Two infant aged 11 and 15 months presented to the Gastroenterology Clinic at Alberta Children's Hospital because of failure to thrive. Clinical and laboratory investigations excluded any underlying abnormality of 1he gastrointestinal tract. Because of a history of obstructive upper respiratory symptoms, both were referred for ear, nose and throat evaluation, and both were found to have partial upper airway obstruction secondary to adenotonsillar hypertrophy. Subsequent adenotonsillectomy led to resolution of obstructive upper respiratory symptoms and dramatic increases in weight gain and growth. Adenotonsillar hypertrophy should be included among the potential causes of failure to thrive in infancy, especially if the child has a history of obstructive upper respiratory symptoms.
Duodenal Lipoma - Report of Two Cases and Review of the Literature
Authors: Goldberg Jeremy , Hamilton Stewart M , Cherry RD , Sherbaniuk RW , Jewell Laurence D
Published: April 2016

Diagnostic upper gastrointestinal endoscopy has increased the frequency with which duodenal lipomas are encountered in clinical practice. Although the smaller lesions are usually incidental endoscopic findings unrelated to symptoms, an accurate diagnosis depends upon biopsy and histological assessment Larger lesions may bleed or obstruct. The authors present two cases: one lipoma was found incidentally during the investigation of an esophageal motility disorder; the other larger one presented as a mass lesion in a patient with upper gastrointestinal bleeding. Pathological findings suggested that the lipoma was the cause of the bleeding. Management is briefly discussed.
Update in Small Bowel Physiology: Part 2
Authors: Fingerote RJ , Churnratanakul S , Keelan M , Madsen K , Thomson ABR
Published: April 2016

The recent advances in clinically important diseases of the small intestine have been reviewed however, the basis for many of these clinical advances rests with important observations on alterations in the physiology of the small intestine, as well as mechanistic observations of alterations in small 1nrestinal function in models of human disease. In this review a summary of the past year's literature is presented which will draw attention to the considerable progress in small bowel physiology which will soon be translated into an improved understanding of the pathophysiology of a variety of intestinal disorders.
Prostaglandins and Mucosal Defensive Mechanisms
Authors: Morris Gerald P , Williamson Todd E , Hynna Taimi T
Published: April 2016

The first line of mucosa! defence includes the juxtamucosal unstirred layer/pH gradient and the apical surface of the luminal epithelial cells. Many damaging agents, including nonsteroidal anti-inflammatory drugs (NSAIDs), can overwhelm these defences and destroy extensive regions of the luminal epithelium. This damage is readily tolerated in the normal mucosa. Furthermore, a combination of increased mucosal bloodflow, epithelial migration, mucus release, and efflux of bicarbonate- rich fluid usually allows rapid recovery of mucosa I integrity. In the presence of vascular damage and congestion, however, luminal acid can kill mucosal cells and destroy the substrate necessary for repair (by epithelial migration). Damage of this type results in the production of hemorrhagic erosions, which may then develop into chronic ulceroinflammatory disease if healing is prevented by excess luminal acid or by impaired mucosal immune response. Endogenous and exogenous prostaglandins could affect all aspects of the mucosal defensive responses, from the juxtamucosal unstirred layer/pH gradient (via effects on secretion of bicarbonate, acid and mucus, as well as stimulation of fluid efflux) to the function of the mucosal immune system. Protection against the acute damage produced by topically administered NSAIDs or concentrated ethanol can result from either administration of prostaglandins or topical application of'mild irritants'. This is referred to as 'adaptive cytoprotection'. Parenterally administered NSAIDs can also produce mucosa! erosions. Protection against this type of damage may depend on the effects of prostaglandins on neural and contractile elements in the mucosa. Studies on animal models also suggest that by preventing acute hemorrhagic erosions, prostaglandins may prevent the development of chronic ulcer in susceptible individuals.
Endoscopic Obturation of Esophageal and Gastric Varices with a Cyanoacrylic Tissue Adhesive
Authors: Gotlib Jean-Pierre
Published: April 2016

An original method of obturation of esophageal and gastric varices with a cyanoacrylic glue has been used for nine years. This method allows treatment of gastric and very large esophageal varices, which is difficult with common endoscopic sclerotherapy, and makes hemostasis in case of acute bleeding easier. There are few complications, none lethal.
Cutting the Difficult Papilla: Ancillary Techniques in the Performance of Endoscopic Sphincterotomy
Authors: Liguory Claude , Lefebvre Jean Francois , Bonnel Didier , Vitale Gary C
Published: April 2016

Of 1040 endoscopic sphincterotomies performed over a five year period, standard papillotomy was possible in 874 (84%). In 166 cases (16%) a difficult papilla was encountered requiring nonstandard techniques of precutting, transpapillary guided endoscopic sphincterotomy, transhepatic guided endoscopic sphincterotomy and percutaneous transhepatic sphincterotomy. The technique first attempted in these 166 cases was successfully completed in 154 (93%). Among the 135 cases with intradiverticular papillas, successful papillotomy was achieved in 125 (92.7%). Early complications of standard endoscopic sphin-.lerotomy included bleeding, perforation, pancreatitis and cholangitis, comprising 4.3% of the 1040 sphincterocomies. There were five deaths (mortality rate 0.5%) and laparotomy was required in six patients (0.6%). Conditions contributing to complications included an intradiverticular papilla and precutting. Evaluation of endoscopic sphincterotomy by transpapillary or transhepatic routes guided by guidewire or drain placement revealed complication rates of 6.6 and 10.6%, respectively. Of the patients with histories of gastric resection and Billroth II anastomoses, standard sphincterotomy was possible in 15 (55.5%); in two cases the papilla was unapproachable endoscopically, requiring use of percutaneous transhepatic sphincterotomy. The percutaneous transhepatic sphincterotomy without endoscopic control is felt to be a higher risk procedure and should be reserved for rare indications. Appropriate use of these techniques should allow performance of endoscopic sphincterotomy in almost all clinical settings.
Dyspepsia Meckeli
Authors: Clark Don , Patel Dilip G
Published: April 2016

A 40-year-old male was seen for evaluation of minor gastrointestinal bleeding. The patient had received an H2blocker as an outpatient for suspicion of duodenal ulcer disease. At endoscopy no lesion was seen and H2blockers were discontinued. The patient developed acute abdomen and at surgery a perforated Meckel's diverticulum was found.
Efficacy of 5-Aminosalicylic Acid Enemas in the Treatment of Distal Ulcerative Colitis
Authors: Robinson MG , Decktor DL
Published: April 2016

The efficacy of 4 g 5-aminosalicylic acid (5-ASA, mesalamine) enemas was assessed in 666 patients with distal ulcerative colitis. Patients were enrolled in an open-label compassionate use program. One 4 g 5-ASA enema was administered each night for a period of four weeks and the disease activity index was assessed at baseline and on days 14 and 28. On days 14 and 28, 78.0% and 88.1% of patients, respectively, demonstrated an improvement in disease activity index. The mean decline in disease activity index on day 14 was 40.7% (P=0.0001) and on day 28 it was 55.4% (P=0.0001). Efficacy was similar whether the disease was confined to or extended beyond 30 cm from the anus. There was no difference in efficacy in patients suffering their first episode of disease compared to patients suffering subsequent attacks. In conclusion, high dose 5-ASA enemas are a highly effective treatment for distal ulcerative colitis.
Pitfalls in Labelled Leukocyte Scanning
Authors: Hodgson H , Roddie M
Published: April 2016

Radiolabelled leukocyte scanning is a valuable tool in the diagnosis and management of inflammatory bowel disease (IBO). As well as determining the presence or absence of disease and its complications, the degree of inflammation may be quantified either visually or numerically following four day fecal collection. The authors discuss the labelling techniques currently in use and the appearance of IBO using both111Indium and99mTechnetium as the labelling isotope. The advantages and disadvantages of each technique are compared. Certain diagnostic pitfalls and causes of false-positive results including radiation enteritis, nonsteroidal anti-inflammatory drug ingestion and intra- and extra-abdominal sepsis are discussed in full, and it is shown that in most cases good labelling technique, careful imaging and awareness of alternative mechanisms for leukocyte appearance in the gastrointestinal tract will ensure correct interpretation of these scans.
Antioxidant Properties of 5-ASA: Potential Mechanism for Its Anti-Inflammatory Activity
Authors: Yamada T , Volkmer C , Grisham MB
Published: April 2016

There is a growing body of experimental data to suggest that the inflamed intestine and/or colon may be subjected to considerable oxidative stress. The most probable source of these oxidants are the phagocytic leukocytes, since these cells are present in large numbers in the inflamed mucosa and are known to produce significant amounts of potentially injurious reactive oxygen species in response to inflammatory stimuli. The authors' laboratory and others have demonstrated that 5-aminosalicylic acid (5-ASA) possesses potent antioxidant activity, including free radical scavenging properties and the ability to decompose neutrophilic oxidants (eg, hypochlorous acid) and detoxify hemoprotein-associated oxidizing agents. 5-ASA has the additional property of being able to chelate iron and render it poorly redox active. Therefore, it is proposed that much of the anti-inflammatory activity of 5-ASA may be due to its numerous antioxidant properties.
Inflammatory Mediators in Inflammatory Bowel Disease
Authors: Peskar BM
Published: April 2016

Tissue responses to an inflammatory stimulus (such as vasodilation, plasma exudation invasion and activation of inflammatory cells) are elicited by locally synthesized chemical mediators. Inhibition of biosynthesis and/or antagonism of action of these mediators is an important target of drug therapy, particularly when the cause of the disease is unknown. Recent investigations have revealed that the mucosa of inflammatory bowel disease (IBD) patients synthesizes a number of inflammatory mediators in increased amounts. These include the potent chemoattractant leukotricne B4, which seems to be responsible for the increase in chemotactic activity found in IBO mucosa, and the cysteinyl leukotrienes, which promote plasma leakage and induce edema formation. Synthesis of leukotrienes in normal and inflamed mucosa is dose-dependently inhibited by sulphasalazine, 5-aminosalicylic acid (5-ASA) and 4-aminosalicylic acid, while indomethacin, which is devoid of therapeutic efficacy in IBD patients, inhibits prostaglandin hut not leukotriene synthesis. These findings suggest that in IBD, mucosal leukotrienes may be more important inflammatory mediators than prostaglandins. ln addition to arachidonic acid-derived products, IBD mucosa generates platelet activating factor and various cytokines including interleukin-1 and tumour necrosis factor, all of which have potent proinflammatory actions. formation of most of these agents is inhibited by sulphasalazine and 5-ASA. The relative importance and the interactions of the various inflammatory mediators synthesized in IBD mucosa remain to be clarified.
Immunogenetic Susceptibilities in Inflammatory Bowel Disease
Authors: Rotter Jerome I
Published: April 2016

It is now clear that the major identified risk factor for the inflammatory bowel diseases (IBDs) is a positive family history. Furthermore, the available data in spouses and twins indicate that the genetic susceptibility is due in large measure to shared familial predisposition. This emphasizes the importance of identifying the actual familial susceptibilities. Given the data for immunopathogenetic etiologies in the genesis of IBD, the logical candidate genes are those that involve the immune system. Data for several of these gene marker systems have been considered confusing or inconclusive. When approached with the concept that IBD is a genetically heterogeneous group of disorders, patterns are beginning to emerge for the human lymphocyte antigen class II region genes on chromosome 6, and the complement C3 gene on chromosome 19. Available data do not yet implicate the immunoglobulin or T cell receptor genes, but further studies are needed, especially for the latter. Firm identification of genetic susceptibilities will require the study of an adequate number of families, which is being facilitated by the establishment of an IBD family-based cell line bank. Identification of the genes that predispose to IBD will allow the study of natural history from susceptibility to clinical disease and, when understood, will provide new approaches to disease therapy and even prevention.
Membrane Function: Its Relationship to Intestinal Absorption and Malabsorption
Authors: Meddings JB
Published: April 2016

It is now clear that both chemical composition and physical properties of the intestinal microvillus membrane are critically important in determining its transport function. Recent advances in this field have been made in research laboratories around the world, and it is important that such data be put in a clinical perspective. The concept of membrane fluidity and the ability to regulate this membrane parameter either pharmacologically or by diet is now an important concept in systemic and local gastrointestinal disease. This review gives an overview of membrane physical properties, how they are measured, and their relationship to nutrient absorption in the intestinal tract. It is not intended to be all inclusive and expressly attempts to make these concepts simple.
Healing of Benign Gastric and Prepyloric Ulcers: A Prospective, Endoscopy-Controlled, Randomized, Double-Blind, Canadian Multicentre Study of Omeprazole 20 and 40 mg Daily and Rantidine 150 mg Twice a Day
Authors: Paré Pierre , Bailey Robert J , Archambault André P , Navert Henri , Williams C Noel , Thomson ABR , Levesque Denis , Farley Alain
Published: April 2016

A double-blind, randomized study was conducted in 118 patients with benign gastric or prepyloric ulcers to compare the efficacy of omeprazole 20 or 40 mg daily with ranitidine 150 mg twice daily. The healing rates at four weeks were 67, 79 and 54% and at eight weeks increased to 90, 97 and 71 % for the omeprazole 20 and 40 mg groups and the ranitidine group, respectively (P< 0.03 for the differences between each of the omeprazole groups and the ranitidine group at eight weeks). Multivariate analysis showed influence on healing rate for ulcer size but not for smoking status, sex or ulcer site. Symptomatic relief was excellent and similar in the three groups. Ulcer recurrence during the six month follow-up off treatment after initial ulcer healing did not differ between the three groups. No serious adverse events could be attributed to the drugs. The authors conclude that treatment with omeprazole 20 or 40 mg daily for a period of four to eight weeks is safe and significantly more effective in ulcer healing than a standard dose of ranitidine.
Endoscopic Placement of Feeding Tubes
Authors: Kandel Gabor P
Published: April 2016

It is no exaggeration to say that percutaneous gastrostomy has revolutionized the feeding of disabled patients with intact gastrointestinal tracts. The most common indication is inability to swallow. It is generally best to place a gastrostomy tube early to prevent malnutrition and minimize complications of procedures on poorly nourished tissue. If a patient is expected to live for only weeks to months, nasoenteric feedings are the nutritional route of choice. Contraindications to percutaneous gastrostomy include coagulation disorders, upper gastrointestinal fistulas, intestinal obstruction, varices, peritoneal dialysis, septicemia and esophageal obstruction. Three techniques are described: 'pull,' 'push' and 'introducer.' The most frequently reported complications are wound infection and pneumoperitoneum. Now that multiple methods for successful insertion of endoscopic percutaneous feeding tubes have been described, the literature appears to be concentrating on complications of the various techniques. Nevertheless, compared to the other options available for patients unable to swallow (allowing malnutrition to proceed, tube feeding, surgical gastrostomy, parenteral nutrition), percutaneous gastrostomy is the procedure of choice in virtually all cases if the intestine is functioning.
Examining the Risks for NSAID-Induced Gastropathy
Authors: Gabriel Sherine E , Bombardier Clarie , Jaakkimainen Liisa
Published: April 2016

The medical literature describing the gastrointestinal risks associated with chronic nonsteroidal anti-inflammatory drug (NSAlD) therapy is increasing rapidly. In spite of this, clinicians remain uncertain about how to translate this information into clinical practice. Clinical decisions regarding the management of adverse reactions to medications have two components. The first involves risk to the patient, and the second an evaluation of available alternatives for managing that risk. Three research designs have been used to examine this association: ecological studies, case control studies and retrospective cohort studies. Although these designs do not provide the strongest evidence for causation, their results point toward the existence of a risk of serious gastrointestinal reactions of between 1.5 and 10 times greater for NSAID users than for nonusers. The wide variation in results is due to multiple factors, including different research designs, study populations and outcome measures. Several subgroups have been suggested to be at particularly high risk. Risk factors include advanced age, female sex, debilitating rheumatoid disease, previous gastrointestinal disease, ethanol abuse and smoking. Only in the elderly has there been adequate data to support this association. Although the data regarding females is compelling, this may be confounded by the documented increased NSAlD use among females. Decision analysis is a useful tool for the quantitative examination of the costs and benefits of management alternatives available for dealing with these risks. Research is needed to identify accurately subgroups of NSAID users at high risk.
Oral Contraceptives, Sex, Pregnancy and Breast Feeding in Inflammatory Bowel Disease
Authors: Allan RN
Published: April 2016

This paper summarizes the scientific basis for advice to inflammatory bowel disease patients concerning oral contraceptives, sex, pregnancy and breast feeding. The physician counselling any individual patient must clearly convert this information into a format suitable for that patient and his family. The information should be reinforced by simple, concise, clear information booklets, such as those produced by the National, Association for Colitis and Crohn's Disease.
The Tight Esophagus - Bougies or Balloons
Authors: Goff John S
Published: April 2016

Esophageal strictures can be managed with a variety of techniques. Each device for dilation has its advantages and disadvantages which are important in selecting the appropriate one for each situation. Stricture management with dilation may require many sessions over a prolonged time. Complications of dilation are infrequent, but perforation must be watched for closely since its consequences are so serious. The most important factor in stricture management with dilators is physician familiarity with the method selected.
Arthritis Associated with Crohn's Disease
Authors: Gilvarry JM , Keeling F , Fitzgerald O , Fielding JF
Published: April 2016

A controlled prospective study was undertaken to determine the incidence and characteristic features of peripheral arthritis, sacroiliitis, ankylosing spondylitis and hypertrophic osteoarthropathy in a group of patients with Crohn's disease, and to define the relationship of such arthritides with disease site, duration and activity. Peripheral arthritis occurred in 14.5% of the patients; it was not seen in the control group. This arthritis, which tended to be pauciarticular, was more common in females with large bowel disease and post dated the bowel symptoms in all but one patient. There was close correlation with disease activity. Radiographic sacroiliitis occurred in 12.7% of the patients and ankylosing spondylitis in 7.3%; neither of these were seen in the control group. Sacroiliitis was more common in females and showed no correlation with either disease activity or human lymphocyte antigen (HLA) B27. Ankylosing spondylitis was seen equally in males and females and showed close correlation with both disease activity and HLA B27. Hypertrophic osteoarthropathy occurred in 9.1% of patients. It was not seen in the control group. All patients were asymptomatic. It showed no correlation with disease activity, finger clubbing, age of disease onset, or HLA B27.