Colonic movements in healthy subjects as monitored by a Magnet Tracking System

Rapport de synthèse : Le Magnet Tracking System (MTS) est une technique peu invasive d'investigation de la motilité de l'entier du tube digestif. Elle repose sur le suivi de la progression d'un aimant par des senseurs externes en temps réel et dans les 3 dimensions. Dans cette étude, le MTS a été utilisé pour étudier les caractéristiques de propulsion propres aux différents segments coliques ainsi que pour comparer le transit de l'aimant permanent du MTS à celui de marqueurs radioopaques habituellement utilisés. Dix hommes et 10 femmes ayant un transit gastro-intestinal régulier ont ingéré simultanément un aimant de MTS et une capsule contenant 10 marqueurs radio-opaques, à 20h00. Les enregistrements se sont ensuite déroulés sur 2 matinées successives de 5 heures. L'analyse des données brutes recueillies a permis de réaliser une projection spatio-temporelle de la trajectoire de l'aimant dans le tube digestif ainsi qu'une description précise de l'origine, de la direction, de l'amplitude et de la vitesse des mouvements coliques. Des radiographies d'abdomen ont permis de comparer les positions respectives des marqueurs radio-opaques et de l'aimant du MTS. Durant 90% du temps d'enregistrement, l'aimant était immobile ou présentait des mouvements alternatifs de faible amplitude. Le reste des enregistrements consiste en activité propulsive dont 20% représentent des déplacements rétrogrades et une description très précise de 34 mouvements de masses. L'analyse des déplacements démontre une distribution bimodales des vitesses voisine de 1.5 et 50 cm /min, ce tant en direction orale que caudale. Deux tiers des distances parcourues le sont à vitesse rapide. L'analyse segmentaire confirme une progression horaire absolue supérieure dans le côlon gauche que droit. L'analyse détaillée par segment colique, reposant sur la description des déplacements enregistrés correspond aux rôles reconnus des différents segments, notamment de aire de stockage et de conditionnement du côlon ascendant ou de transit du côlon descendant. La comparaison des 2 sexes démontre un nombre plus important de mouvements, particulièrement de mouvements de masse chez l'homme. Les radiographies montrent une bonne corrélation entre la position de l'aimant et celle des marqueurs radio-opaques. Le MTS permet ainsi une description précise des caractéristiques propulsives des différents segments coliques, notamment par l'analyse détaillée des progressions à vitesses lente et rapide et leurs directions. Des distinctions peuvent également être notées en fonction du sexe. Ces investigations offrent de nouvelles perspectives pour l'étude des troubles de la motilité digestive.

Direct electrical stimulation using a battery-operated device for induction and modulation of colonic contractions in pigs.

Direct electrical stimulation of the colon offers a promising approach for the induction of propulsive colonic contractions by using an implantable device. The objective of this study was to assess the feasibility to induce colonic contractions using a commercially available battery-operated stimulator (maximum pulse width of 1 ms and maximum amplitude of 10 V). Three pairs of pacing electrodes were inserted into the cecal seromuscular layer of anesthetized pigs. During a first set of in vivo experiments conducted on six animals, a pacing protocol leading to cecum contractions was determined: stimulation bursts with 1 ms pulse width, 10 V amplitude (7-15 mA), 120 Hz frequency, and 30-s burst duration, repeated every 2-5 min. In a second testing phase, an evaluation of the pacing protocol was performed in four animals (120 stimulation bursts in total). By using the battery-operated stimulator, contractions of the cecum and movement of contents could be induced in 92% of all stimulations. A cecal shortening of about 30% and an average intraluminal pressure increase of 10.0 +/- 6.0 mmHg were observed.

Transit Manager's Handbook, September, 2010

This handbook provides an overview of public transit in Iowa and how to do business with the Iowa Department of Transportation (Iowa DOT) Office of Public Transit (OPT). It is intended to be a tool to assist transit managers navigate through the many policies, procedures and requirements of state and federal government. This handbook can be used to provide orientation for new personnel; to help clarify the relationships and required procedures for existing personnel; and to provide easier accessibility to regulations and procedures. Input on the content of the handbook to increase its usefulness is encouraged at any time.

Cedar-Iowa River Rail Transit Project Feasibility Study, November 9, 2006

Five Seasons Transportation & Parking (FSTP) and the Johnson County Council of Governments (JCCOG) are interested in evaluating the feasibility of prospective passenger rail service(s) that would operate over existing trackage of the Cedar Rapids and Iowa City Railway Company (CRANDIC), seen below left, and/or the Iowa Interstate Railroad System (IAIS), seen below right, connecting Cedar Rapids, Iowa City and the Amana Colonies. To perform the study, FSTP and JCCOG selected R.L. Banks & Associates, Inc. (RLBA) as Prime Contractors, HNTB Corporation (HNTB) and Snyder & Associates, Inc. (Snyder) as Subcontractors, hereafter Consultant Team. Both railroads participated in the study and contributed time and resources, as did many local government and civic organizations. The purpose of the study is to determine whether it is feasible to establish regularly scheduled passenger rail service and/or special event excursion rail service, in conjunction with the Five Seasons Transit system, Iowa City Transit, East Central Iowa Transit, Coralville Transit and the University of Iowa CAMBUS.

Evaluation of In-Use Fuel Economy and On-Board Emissions for Hybrid and Regular CyRide Transit Buses, October 2012

The objective of this project was to evaluate the in-use fuel economy and emission differences between hybrid-electric and conventional transit buses for the Ames, Iowa transit authority, CyRide. These CyRide buses were deployed in the fall of 2010. Fuel economy was compared for the hybrid and control buses. Several older bus types were also available and were included in the analysis. Hybrid buses had the highest fuel economy for all time periods for all bus types. Hybrid buses had a fuel economy that was 11.8 percent higher than control buses overall, 12.2 percent higher than buses with model years 2007 and newer, 23.4 percent higher than model years 2004 through 2006, 10.2 percent higher than model years 1998 through 2003, 38.1 percent higher than model years 1994 through 1997, 36.8 percent higher than model years 1991 through 1993, and 36.8 percent higher for model years pre-1991. On-road emissions were also compared for three of the hybrid buses and two control buses using a portable emissions monitor. On-average, carbon dioxide, carbon monoxide, and hybrid carbon emissions were much higher for the control buses than for the hybrid buses. However, on average nitrogen oxide emissions were higher for the hybrid buses.

Endoluminal surgical triangulation: overcoming challenges of colonic endoscopic submucosal dissections using a novel flexible endoscopic surgical platform: feasibility study in a porcine model.

BACKGROUND: Colonic endoscopic submucosal dissection (ESD) is challenging as a result of the limited ability of conventional endoscopic instruments to achieve traction and exposure. The aim of this study was to evaluate the feasibility of colonic ESD in a porcine model using a novel endoscopic surgical platform, the Anubiscope (Karl Storz, Tüttlingen, Germany), equipped with two working channels for surgical instruments with four degrees of freedom offering surgical triangulation. METHODS: Nine ESDs were performed by a surgeon without any ESD experience in three swine, at 25, 15, and 10 cm above the anal verge with the Anubiscope. Sixteen ESDs were performed by an experienced endoscopist in five swine using conventional endoscopic instruments. Major ESD steps included the following for both groups: scoring the area, submucosal injection of glycerol, precut, and submucosal dissection. Outcomes measured were as follows: dissection time and speed, specimen size, en bloc dissection, and complications. RESULTS: No perforations occurred in the Anubis group, while there were eight perforations (50 %) in the conventional group (p = 0.02). Complete and en bloc dissections were achieved in all cases in the Anubis group. Mean dissection time for completed cases was statistically significantly shorter in the Anubis group (32.3 ± 16.1 vs. 55.87 ± 7.66 min; p = 0.0019). Mean specimen size was higher in the conventional group (1321 ± 230 vs. 927.77 ± 229.96 mm(2); p = 0.003), but mean dissection speed was similar (35.95 ± 18.93 vs. 23.98 ± 5.02 mm(2)/min in the Anubis and conventional groups, respectively; p = 0.1). CONCLUSIONS: Colonic ESDs were feasible in pig models with the Anubiscope. This surgical endoscopic platform is promising for endoluminal surgical procedures such as ESD, as it is user-friendly, effective, and safe.

The Influence of Diet and Microbes on Colonic Immune Regulation and their Implications on Type 1 Diabetes

Dietary and microbial factors are thought to contribute to the rapidly increasing prevalence of T1D in many countries worldwide. The impact of these factors on immune regulation and diabetes development in non-obese diabetic (NOD) mice are investigated in this thesis. Diabetes can be prevented in NOD mice through dietary manipulation. Diet affects the composition of intestinal microbiota, which may subsequently influence intestinal immune homeostasis. However, the specific effects of anti-diabetogenic diets on gut immunity and the explicit associations between intestinal immune disruption and type 1 diabetes onset remain unclear. The research presented herein demonstrates that newly weaned NOD mice suffer from a mild level of colitis, which shifts the colonic immune cell balance towards a proinflammatory status. Several aberrations can also be observed in the peritoneal B cells of NOD mice; an increase in activation marker expression, increased trafficking to the pancreatic lymph nodes and significantly higher antigen presenting cell (APC) efficiency towards insulin-specific T cells. A shift towards inflammation is likewise observed in the colon of germ-free NOD mice, but signs of peritoneal B cell activation are lacking in these mice. Remarkably, most of the abnormalities in the colon, peritoneal macrophages and the peritoneal B cell APC activity of NOD mice are abrogated when NOD mice are maintained on a diabetes-preventive, soy-based diet (ProSobee) from the time of weaning. Dietary and microbial factors hence have a significant impact on colonic immune regulation and peritoneal B cell activation and it is suggested that these factors influence diabetes development in NOD mice.

Intrinsic denervation of the colon is associated with a decrease of some colonic preneoplastic markers in rats treated with a chemical carcinogen

Denervation of the colon is protective against the colon cancer; however, the mechanisms involved are unknown. We tested the hypothesis that the denervated colonic mucosa could be less responsive to the action of the chemical carcinogen dimethylhydrazine (DMH). Three groups of 32 male Wistar rats were treated as follows: group 1 (G1) had the colon denervated with 0.3 mL 1.5 mM benzyldimethyltetradecylammonium (benzalkonium chloride, BAC); G2 received a single ip injection of 125 mg/kg DMH; G3 was treated with BAC + the same dose and route of DMH. A control group (Sham, N = 32) did not receive any treatment. Each group was subdivided into four groups according to the sacrifice time (1, 2, 6, and 12 weeks after DMH). Crypt fission index, ß-catenin accumulated crypts, aberrant crypt foci, and cell proliferation were evaluated and analyzed by ANOVA and the Student t-test. G3 animals presented a small number of aberrant crypt foci and low crypt fission index compared to G2 animals after 2 and 12 weeks, respectively. From the second week on, the index of ß-catenin crypt in G3 animals increased slower than in G2 animals. From the 12th week on, G2 animals presented a significant increase in cell proliferation when compared to the other groups. Colonic denervation plays an anticarcinogenic role from early stages of colon cancer development. This finding can be of importance for the study of the role of the enteric nervous system in the carcinogenic process.

Personal soundtracks on public transit : personal listening devices and socio-spatial negotiations of students' bus journeys

One way of exploring the power of sound in the experience and constitution of space is through the phenomenon of personal listening devices (PLDs) in public environments. In this thesis, I draw from in-depth interviews with eleven Brock University students in S1. Catharines, Ontario, to show how PLDs (such as MP3 players like the iPod) are used to create personalized soundscapes and mediate their public transit journeys. I discuss how my interview participants experience the space-time of public transit, and show how PLDs are used to mediate these experiences in acoustic and non-acoustic ways. PLD use demonstrates that acoustic and environmental experiences are co-constitutive, which highlights a kinaesthetic quality of the transit-space. My empirical findings show that PLDs transform space, particularly by overlapping public and private appropriations of the bus. I use these empirical findings to discuss the PLD phenomenon in the theoretical context of spatiality, and more specifically, acoustic space. J develop the ontological notion of acoustic space, stating that space shares many of the properties of sound, and argue that sound is a rich epistemological tool for understanding and explaining our everyday experiences.

Décliner la frontière : transit et contagion de la violence dans la fiction sacrificielle de Bernard-Marie Koltès

Ce mémoire de maîtrise traite de quatre pièces de l’auteur français Bernard-Marie Koltès. Résolument axé sur l’étude du texte écrit, il vise dans un premier temps l’analyse d’un ensemble de désajustements et d’une culture de l’équivoque dans le traitement du lieu, du temps et de l’identité. Le premier but de ces analyses est l’approfondissement de certaines avenues déjà investies par la critique (marginalité des lieux et des personnages, présence constante de la violence et de la mort, etc.), dans la recherche d’une signification globale à un ensemble de pratiques textuelles liées à la notion de limite ou de frontière. Opérant un changement de perspective, la seconde partie de l’étude s’attarde à la violence ainsi qu’aux modalités et implications de sa mise en texte dans une étude croisée de l’acte créateur et de la pratique de lecture. À partir de la théorie du sacrifice élaborée par René Girard dans La violence et le sacré, et faisant dialoguer certains textes importants d’auteurs divers (Aristote, Nietzsche, Artaud, Foucault, Derrida et Adorno), l’analyse vise à inscrire la littérarité du texte koltésien dans une entreprise plus vaste ayant à voir avec la violence, sa régulation et sa diffusion. Au carrefour des études théâtrales, de la littérature et de la philosophie, cette réflexion cherche à concevoir le théâtre de Koltès (particulièrement Roberto Zucco) comme un sacrifice rituel, afin de mieux en comprendre le rapport au réel et certaines de ses particularités du point de vue du mécanisme cathartique.

Differential induction of apoptosis in human colonic carcinoma cells (Caco-2) by Atopobium, and commensal, probiotic and enteropathogenic bacteria: mediation by the mitochondrial pathway

The induction of apoptosis in mammalian cells by bacteria is well reported. This process may assist infection by pathogens whereas for non-pathogens apoptosis induction within carcinoma cells protects against colon cancer. Here, apoptosis induction by a major new gut bacterium, Atopobium minutum, was compared with induction by commensal (Escherichia coli K-12 strains), probiotic (Lactobacillus rhamnosus, Bifidobacterium latis) and pathogenic (E. coli: EPEC and VTEC) gut bacteria within the colon cancer cell line, Caco-2. The results show a major apoptotic effect for the pathogens, mild effects for the probiotic strains and A. minutum, but no effect for commensal E. coli. The mild apoptotic effects observed are consistent with the beneficial roles of probotics in protection against colon cancer and suggest, for the first time, that A. minutum possesses similar advantageous, anti-cancerous activity. Although bacterial infection increased Caco-2 membrane FAS levels, caspase-8 was not activated indicating that apoptosis is FAS independent. Instead, in all cases, apoptosis was induced through the mitochondrial pathway as indicated by BAX translocation, cytorchrome c release, and caspase-9 and -3 cleavage. This suggests that an intracellular stimulus initiates the observed apoptosis responses.

Determinants of Accelerated Small Intestinal Transit in Alcohol-Related Chronic Pancreatitis

Patients with chronic pancreatitis may have abnormal gastrointestinal transit, but the factors underlying these abnormalities are poorly understood. Gastrointestinal transit was assessed, in 40 male outpatients with alcohol-related chronic pancreatitis and 18 controls, by scintigraphy after a liquid meal labeled with (99m)technetium-phytate. Blood and urinary glucose, fecal fat excretion, nutritional status, and cardiovascular autonomic function were determined in all patients. The influence of diabetes mellitus, malabsorption, malnutrition, and autonomic neuropathy on abnormal gastrointestinal transit was assessed by univariate analysis and Bayesian multiple regression analysis. Accelerated gastrointestinal transit was found in 11 patients who showed abnormally rapid arrival of the meal marker to the cecum. Univariate and Bayesian analysis showed that diabetes mellitus and autonomic neuropathy had significant influences on rapid transit, which was not associated with either malabsorption or malnutrition. In conclusion, rapid gastrointestinal transit in patients with alcohol-related chronic pancreatitis is related to diabetes mellitus and autonomic neuropathy.

Alginate-chitosan systems: In vitro controlled release of triamcinolone and in vivo gastrointestinal transit

The aim of this study was to develop multiparticulate therapeutic systems of alginate (AL) and chitosan (CS) containing triamcinolone (TC) to colonic drug delivery. Multiparticulate systems of AL-CS, prepared by a complex coacervation/ionotropic gelation method, were characterized for morphological and size aspects, swelling degree, encapsulation content and efficiency, in vitro release profile in different environments simulating the gastrointestinal tract (GIT) and in vivo gastrointestinal transit. The systems showed suitable morphological characteristics with particle diameters of approximately 1.6 mm. In simulated gastric environment, at pH 1.2, the capsules presented low degree of swelling and in vitro release of drug. A higher swelling degree was observed in simulated enteric environment, pH 7.5, followed by erosion. Practically all the drug was released after 6 h of in vitro assay. The in vivo analysis of gastrointestinal transit, carried out in rats, showed that the systems passed practically intact through the stomach and did not show the same profile of swelling observed in the in vitro tests. It was possible to verify the presence of capsules in the colonic region of GIT. The results indicate that AL-CS multiparticulate systems can be used as an adjuvant for the preparation of therapeutic systems to colonic delivery of drugs. (C) 2010 Elsevier Ltd. All rights reserved.

Chitosan-pectin multiparticulate systems associated with enteric polymers for colonic drug delivery

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

AC Biosusceptometry Technique to Evaluate the Gastrointestinal Transit of Pellets under Influence of Prandial State

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)