Thesis (M.S.)--University of Wisconsin--Madison, 1984. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 13-15).

Efter operation och anestesi får patienter ofta en negativ påverkan på magsäck och tarmar. Illamående och kräkningar är ett stort problem och många har svårt att komma igång med intag av föda och normal tarmfunktion då magsäcken och tarmarna ”står stilla”. Flera faktorer bidrar- bl.a. smärtan, det kirurgiska traumat och de läkemedel vi ger i samband med anestesin. Av de senare är opioider, d.v.s morfin och morfinliknande läkemedel, starkt bidragande. I detta avhandlings- arbete har opioiders effekter på magsäckens motilitet studerats. Med ett absorptionstest (paracetamolmetoden) studerades hos frivilliga hur opioiden remifentanil påverkar magsäckstömning och om kroppspositionen har betydelse för tömningshastigheten ut i tarmen. Remifentanil fördröjde magsäcks-tömningen och under pågående opioid behandling hade kroppspositionen ingen större betydelse, vilket det däremot hade under kontrollförsöken. Med samma metod jämförde vi hos patienter två anestesimetoder och studerade magsäcks-tömning direkt efter en operation. Ingen skillnad kunde påvisas mellan en opioidbaserad och en opioidfri anestesi, men inom respektive grupp var det en stor variation i magsäckstömning mellan individerna. Med en barostat studerades tonus i övre delen av magsäcken. Hos hälften av de frivilliga orsakade remifentanil en ökning av tonus och hos den andra hälften en minskning av tonus. Vidare undersöktes hos en grupp patienter opioiden fentanyls påverkan på den elektriska aktiviteten i magsäcken. Med en elekroga-strograf (EGG) registrerades de långsamma elektriska vågor som koordinerar muskelrörelserna i magsäcken. Hos hälften av de undersökta påverkades aktiviteten av fentanyl med en sänkt vågfrekvens eller upphörande av vågor, medan aktiviteten var opåverkad hos den övriga hälften. För att finna en förklaring till variationen gjordes genetiska analyser av genen för opioidreceptorn hos de undersökta i barostat och EGG studierna. Variationer i genomet, s.k. polymorfism, var inte associerad till utfallen i studierna. Studierna har visat på att opioider har en uttalad effekt på magsäckens motilitet och att den varierar kraftigt mellan individer. Polymorfism i genen för opioid- receptorn förklarade inte skillnaden mellan individer. Direkt efter operation bidrar sannolikt andra faktorer än anestesimetod till det variabla utfallet i magsäckstömning. / After anesthesia and/or surgical procedures, gastrointestinal motility is commonly impaired. The causes are multifactorial, with surgical trauma, pain and perioperative drugs playing a major role. This thesis explores opioid effects on gastric motility in healthy volunteers and patients undergoing surgery. Gastric emptying was studied by an absorption test (paracetamol method), and in healthy volunteers a remifentanil infusion delayed gastric emptying. Body position altered emptying during the control situations, but not during the remifentanil infusion. Further, two anesthetic methods were compared and no differences were found in immediate postoperative gastric emptying between a remifentanil/propofol based intravenous anesthesia and an opioid free inhalational anesthesia, although the interindividual variability was high. Proximal gastric tone was studied using a gastric barostat. An infusion of remifentanil caused two patterns of reaction regarding gastric tone, with half of the subjects increasing and half decreasing in gastric tone. Gastric myoelectrical activity was evaluated with electrogastrography (EGG), and a bolus dose of fentanyl caused a decrease in frequency of the gastric slow waves or disrupted this activity. However, the activity was unaffected in half of the investigated subjects. Analysis of polymorphisms (A118G and G691C) in the µ-opioid receptor gene was performed to find an explanation for the great interindividual variations seen in the barostat and EGG studies, but no association could be found. These studies have shown that opioids have pronounced effects on gastric motility with variable individual responses that are difficult to predict. Polymorphisms in the µ-opioid receptor gene could not explain the variations. Postoperatively, other factors might contribute more than opioids to the impairment in gastric motility. / ISSN 1652-4063

Electrical activity of the stomach is one determining factor of gastric motility by controlling and coordinating contractions of the gastric musculature. These contractions, both tonic and phasic, are responsible for the storing, mixing, and emptying of food. Gastric electrical activity is therefore a very important factor for normal stomach function. The development of a multi-channel, bandlimited, signal amplifier and recording system, provides a means to record this electrical activity. Many practical issues are addressed to provide a signal of acceptable quality and several basic signal processing techniques are applied to increase the quality of these signals and provide extraction of important information regarding power and frequency content. Gastric electrical activity is recorded from the stomachs of several rats in various experiments. The recorded activity in different regions of the stomach, responsible for different functions, is compared and evaluated with respect to known cellular events. By introducing several stimuli and observing changes in recorded activity, the nervous control of the stomach via mediation of the electrical activity is also examined and modeled briefly. / Thesis / Master of Engineering (ME)

Orientador: Madileine Francely Américo / Resumo: Os imunossupressores são utilizados após o transplante de órgãos e no tratamento de doenças autoimunes, desencadeando diversos efeitos colaterais. No esquema tríplice de imunossupressão pós-transplante, cada droga ou a combinação delas podem alterar a estrutura e/ou funcionamento do trato gastrintestinal. Apesar da importância do trato gastrintestinal e de conhecer os efeitos da ingesta oral de imunossupressores, há poucos estudos enfocando esses aspectos e vários desafios éticos para essas avaliações no homem. Desse modo, objetivou-se avaliar as alterações provocadas pela imunossupressão nos parâmetros de esvaziamento gástrico, frequência e amplitude das contrações gástricas, bem como as alterações histológicas no estômago de ratos. Para isso foram utilizados a Biosusceptometria de Corrente Alternada (BAC) e a Eletrogastrografia (EGG). No primeiro capítulo, avaliou-se individualmente sete imunossupressores de diferentes classes (Tacrolimo, Ciclosporina, Micofenolato Mofetil, Azatioprina, Sirolimo, Everolimo e Prednisona) comumente utilizados na terapia imunossupressora. Todos os imunossupressores estudados, exceto o Micofenolato Mofetil causaram alguma alteração nos parâmetros gastrintestinais analisados em ratos. Já o segundo capítulo apresenta os efeitos da terapia imunossupressora combinada, baseada em três classes de imunossupressores (inibidores da calcineurina, antimetabólitos e glicocorticoides). Um dos grupos experimentais recebeu Tacrolimo associado à Micofenolato S... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Immunosuppressants are used after organ transplantation and in the treatment of autoimmune diseases, triggering several side effects. In the triple regimen of post - transplant immunosuppression, each drug or combination of them may alter the structure and / or function of the gastroin testinal tract. Despite the importance of gastrointestinal tract and knowledge of the effects of oral intake of immunosuppressants, there are few studies focusing on these aspects and several ethical challenges for these evaluations in humans. The aim of t his study was to evaluate the effects provoked by immunosuppression in gastric emptying parameters, frequency and amplitude of gastric contractions, as well as the histological aspects in the stomach of rats. Alternating Current Biosusceptometry (BAC) and Electrogastrography (EGG) were used. In the first chapter, seven immunosuppressants from different classes (Tacrolimus, Cyclosporine, Mycophenolate Mofetil, Azathioprine, Sirolimus, Everolimus and Prednisone) commonly used in immunosuppressive therapy were evaluated individually. All immunosuppressants studied except Mycophenolate Mofetil , caused some alteration in the gastrointestinal parameters analyzed in rats. The second chapter presents the effects of combined immunosuppressive therapy based on three c lasses of immunosuppressants (calcineurin inhibitors, antimetabolites and glucocorticoids). One of the experimental groups received Tacrolimus associated with Mycophenolate Sodium and Pr... (Complete abstract click electronic access below) / Doutor

Author of this dissertation presentation discuss in the begining definition and historical consequences of origin and consecutive evolution of the method of percutaneous electrogastrography. Intimately is described physiology, anatomy, embryology and function of gastrointestinal tract with special interest on construction and function of the stomach. Next to this author analyses current knowledge about location and function of the gastric pace setter. The technique of used perctutaneous electrogastrography equipmentt is described. In the second part results of original studies monitoring restoration of peristalsis in perioperative period at patients after open and laparoscopic cholecystectomy and laparoscopic non-adjustable gastric banding are discussed. Furthermore results of EGG measurement of patients with mechanic, vascular and paralytic intestinal obstruction are presented in correlation with plasma levels of interleukin 1β, interleukin-6, procalcitonin and C-reactive protein. Key words: Percutanous electrogastrography, laparoscopic cholecystectomy, laparoscopic gastric bandage, inflammatory mediators, intestinal obstruction.

Author of this dissertation presentation discuss in the begining definition and historical consequences of origin and consecutive evolution of the method of percutaneous electrogastrography. Intimately is described physiology, anatomy, embryology and function of gastrointestinal tract with special interest on construction and function of the stomach. Next to this author analyses current knowledge about location and function of the gastric pace setter. The technique of used perctutaneous electrogastrography equipmentt is described. In the second part results of original studies monitoring restoration of peristalsis in perioperative period at patients after open and laparoscopic cholecystectomy and laparoscopic non-adjustable gastric banding are discussed. Furthermore results of EGG measurement of patients with mechanic, vascular and paralytic intestinal obstruction are presented in correlation with plasma levels of interleukin 1β, interleukin-6, procalcitonin and C-reactive protein. Key words: Percutanous electrogastrography, laparoscopic cholecystectomy, laparoscopic gastric bandage, inflammatory mediators, intestinal obstruction.