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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Timing and Mechanism of Sepsis-Induced Delayed Gastric Emptying in a Novel Mouse Model

Samis, Andrew James Willis 09 May 2012 (has links)
Sepsis-induced delayed gastric emptying is a significant clinical problem for patients in intensive care units worldwide. A series of studies were carried out to examine the nature and mechanisms of sepsis-induced delayed gastric emptying using a novel mouse model which used a standard food source and was devoid of upper gastrointestinal tract trauma and restraint. Using this model, lipopolysaccharide (LPS) injection produced a dose-dependent decrease in gastric emptying which onset by one hour. LPS produced an alteration in mouse behavior and piloerection at 30 minutes, increased resting respiratory rate at 3 hours, and did not impact body temperature. The onset of sepsis-induced delayed gastric emptying was closer to those centrally-mediated clinical signs of sepsis (altered behavior and piloerection) than to the peripherally-mediated clinical signs (respiratory rate) suggesting a central mechanism. C-Fos activation of the area postrema (AP), the nucleus of the solitary tract (NTS), and the dorsal motor nucleus of the vagus (DMV) was examined 30 minutes after LPS injection which is the onset time for sepsis-induced delayed gastric emptying. LPS exposure produced significantly more activated neurons in the AP and NTS, and less in the DMV. These results may suggest a central mechanism with the AP and NTS inhibiting the DMV. Examination of isolated strips of gastric antrum in a tissue bath showed a decreased contractile response to electrical field stimulation and carbachol after injection of LPS. This occurred at 18 hours post LPS injection, but not at 6 hours. Using the mouse model, sepsis-induced delayed gastric emptying was shown to be occurring at 6 hours when no difference in contractility was measurable suggesting intrinsic changes are not the cause. These studies suggest a new mechanistic paradigm for sepsis-induced delayed gastric emptying in which there is a biphasic response. This involves an initial rapid, centrally-mediated delay in gastric emptying occurring the first hour and followed by an intrinsic tissue-level response several hours later characterized by a decrease in gastric muscle contractility. / Thesis (Ph.D, Biology) -- Queen's University, 2012-05-02 16:17:55.564
2

Clinical and experimental studies of dumping disposition a method for preoperative evaluation of individual dumping disposition /

Fenger, Hans Jørgen. January 1967 (has links)
Thesis (doctoral)--University of Copenhagen.
3

Clinical and experimental studies of dumping disposition a method for preoperative evaluation of individual dumping disposition /

Fenger, Hans Jørgen. January 1967 (has links)
Thesis (doctoral)--University of Copenhagen.
4

Highly Variable Gastric Emptying in Patients With Insulin Dependent Diabetes Mellitus

Nowak, T. V., Johnson, C. P., Kalbfleisch, J. H., Roza, A. M., Wood, C. M., Weisbruch, J. P., Soergel, K. H. 01 January 1995 (has links)
Some diabetic patients - particularly those with nausea and vomiting - frequently have evidence of delayed gastric emptying while other diabetic patients may in fact exhibit accelerated gastric emptying. Whether the presence or absence of symptoms of upper gastrointestinal dysfunction correlated with objective measures of gastric emptying in insulin dependent diabetic subjects was investigated. Twenty one insulin dependent diabetic patients underwent a solid phase gastric emptying scintiscan using in vivo labelled chicken patients had symptoms Thirteen patients had symptoms suggestive of gastrointestinal dysfunction (nausea, vomiting, early satiety, or constipation), while eight patients had no gastrointestinal symptoms. Eleven patients had orthostatic hypotension. All patients had been diabetic since childhood or adolescence. As a group, the diabetic patients showed a half time (T50) of gastric emptying (mean (SD) 150.0 min (163.7) that was not significantly different from that of 12 healthy control subjects (148.1 min (62.4)). Those diabetic patients without gastrointestinal symptoms and without orthostatic hypotension, however, showed a gastric emptying half time (70.1 min (41.6)) that was significantly faster than that of the control subjects. Conversely, those diabetic patients with nausea, vomiting, and early satiety (or early satiety alone) showed T50 values that were significantly greater than those of the diabetic patients without these symptoms. No correlation was found between the T50 value and the duration of diabetes, the fasting blood glucose at the time of study, or the respiratory variation in heart rate (E:I ratio). These observations indicate that highly variable rates of gastric emptying occur in insulin dependent diabetic patients, and that accelerated gastric emptying may occur in diabetic patients who have no symptoms of gastrointestinal dysfunction.
5

Kinetics of starch digestion and glucose assimilation in normal and colectomized humans

Robertson, Margaret Denise January 1997 (has links)
No description available.
6

The relationship between motility and gastrointestinal transit of tablets

Mitchell, Catherine Lindsay January 1996 (has links)
No description available.
7

A development of some simple measures for assessing gastrointestinal transit in clinical pharmacology with special reference to variability and validity

Staniforth, David Harold January 1997 (has links)
No description available.
8

Development of nuclear medicine methods for gastric and small bowel motility : effects of GLP-1 on gastric emptying /

Grybäck, Per, January 2005 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 5 uppsatser.
9

Estado nutricional, sintomas dispÃpticos e nÃveis de grelina em pacientes portadores de doenÃa de Crohn-correlaÃÃo com a atividade da doenÃa

Kamila Maria Oliveira Sales 15 March 2013 (has links)
nÃo hà / A perda de peso à uma queixa comum dos pacientes com doenÃa de Crohn, estando a desnutriÃÃo presente em 30-80% dos portadores dos casos. Foi demonstrado que pacientes com doenÃa de Crohn em inatividade apresentam sintomas dispÃpticos relacionados com alteraÃÃo no esvaziamento gÃstrico. No entanto, a correlaÃÃo da atividade da doenÃa com os parÃmetros antropomÃtricos, nutricionais e de saciedade ainda à objeto de investigaÃÃo. Portanto, o objetivo do nosso estudo foi correlacionar a atividade da doenÃa com o estado nutricional, sintomas dispÃpticos, esvaziamento gÃstrico, saciedade e nÃveis de grelina em pacientes com doenÃa de Crohn. Trata-se de um estudo transversal, analÃtico e quantitativo realizado em vinte pacientes com doenÃa de Crohn, classificados segundo um Ãndice de Atividade de DoenÃa de Crohn (Crohnâs Disease Activity Index â CDAI). Os pacientes foram submetidos a uma avaliaÃÃo nutricional, que se fundamentou na utilizaÃÃo de mÃtodos duplamente indiretos (Ãndice de massa corporal, dobra cutÃnea tricipital e circunferÃncia do braÃo). AlÃm disso, nos pacientes foi avaliado o consumo alimentar atravÃs de um recordatÃrio alimentar. Estes foram tambÃm submetidos a uma anÃlise do tempo de esvaziamento gÃstrico por teste respiratÃrio usando o 13C - Ãcido octanÃico ligado a uma refeiÃÃo sÃlida - e responderam a um questionÃrio validado (QuestionÃrio Porto Alegre de Sintomas DispÃpticos) para avaliar os sintomas dispÃpticos. Outro teste realizado foi o teste de saciedade(drinking test), no qual o paciente ingeriu 15 ml de uma bebida lÃquida padrÃo(Nutridrink), e era lhe perguntado o nÃvel de saciedade atravÃs de uma escala analÃgica. Durante o teste respiratÃrio, foram realizadas coletas de amostras de sangue para dosagem de grelina: basal( jejum) e pÃs-prandial. Os dados foram analisados estatisticamente pelos testes: t de Student, exato de Fisher, Mann-Whitney e correlaÃÃo de Spearman. Observou-se que os parÃmetros CDAI e IMC (p=0,0185) e CB (p=0,023) foram inversamente proporcionais, porÃm nÃo houve diferenÃa estatÃstica entre as correlaÃÃes do CDAI com prega cutÃnea tricipital( p=0,0543). Os pacientes nÃo apresentaram correlaÃÃo da atividade da doenÃa com o esvaziamento gÃstrico ( t Â- p=0,2533; t lag-p=0,3079). Entretanto, houve correlaÃÃo significativa do CDAI com todos os sintomas dispÃpticos (p=0,005). NÃo se verificou correlaÃÃo da atividade da doenÃa e o volume de lÃquido suportado. Entretanto, a atividade da doenÃa influenciou os nÃveis de grelina no pÃs-prandial (p=0,04). CONCLUSÃO: A atividade da doenÃa correlaciona-se com o estado nutricional, a presenÃa de sintomas dispÃpticos e nÃveis de grelina de pacientes portadores de doenÃa de Crohn. Entretanto nÃo existe correlaÃÃo com alteraÃÃes no esvaziamento gÃstrico e saciedade sugerindo que outros mecanismos possam estar envolvidos.
10

Efeito anti-ulcerogenico do extrato de Chlorella vulgaris / Antiulcerogenic effect of Chlorella vulgaris extract

Vinagre, Adriana Mendes 05 September 2005 (has links)
Orientadores: Edgard Ferro Collares, Alba Regina Monteiro Souza Brito / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-05T21:01:46Z (GMT). No. of bitstreams: 1 Vinagre_AdrianaMendes_M.pdf: 520546 bytes, checksum: 8639e020093258b50bba40d8d83f839c (MD5) Previous issue date: 2005 / Resumo: A úlcera péptica acomete cerca de 10% da população mundial; inseridos dentro dessa porcentagem estão milhares de brasileiros. Essa patologia é causada por um desbalanço entre os mecanismos protetores e agressores da mucosa, e é resultado da associação de diversos fatores agressores endógenos (ácido, pepsina e bile), fatores exógenos predisponentes às condições de vida (estresse, fumo, álcool, uso continuo de drogas antiflamatórias não esteróides, ingestão de determinados alimentos e a presença do Helicobacter pylori) e a predisposição genética. Atualmente, as terapêuticas utilizadas no tratamento das lesões são: antiácidos, anticolinérgicos, antagonistas de receptores H2 para histamina, inibidores da bomba de próton, antibióticos e mais raramente alguns procedimentos cirúrgicos. A aplicação de qualquer esquema terapêutico com emprego de uma ou mais destas drogas ou procedimento cirúrgico pode ocasionar alguns efeitos colaterais e não obrigatoriamente é eficaz. A utilização de plantas medicinais no tratamento de doenças vem se desenvolvendo na última década. Algumas plantas têm atividade antiulcerogênica. Há evidências que a alga Chlorella vulgaris pode modificar a resposta imune celular, tem atividade antitumoral, antimetastática e antiulcerogênica. O objetivo do presente estudo foi avaliar a atividade antiulcerogênica da alga Chlorella vulgaris em modelos agudos e um modelo crônico de indução de úlceras. Ratos Wistar foram utilizados para determinação do esvaziamento gástrico (EG) e modelos de úlcera induzida por etanol e ácido acético, enquanto camundongos swiss foram utilizados para os modelos de úlcera através de ligadura do piloro e piroxicam. Para avaliar o efeito sobre o esvaziamento gástrico (EG) do extrato de Chlorella vulgaris (ECV) foi utilizada uma refeição de prova (RP) liquida com extrato nas concentrações de 50mg/mL e 100mg/mL do ECV. Para o estudo dos modelos agudos de ligadura do piloro, etanol e piroxicam e do modelo crônico, foram utilizadas as doses de 250, 500 e 1000mg/kg de ECV para a prevenção e o tratamento das lesões. No modelo crônico também foi utilizada a fração acetato obtida do ECV na dose de 5mg/100g e foi dosada a quantidade de fator de crescimento epidermal (EGF) produzido na região da úlcera. O estudo da toxicidade do ECV foi realizado através da medida de ganho de peso dos ratos e peso dos órgãos como rins, pulmões, fígado e coração, visto que os primeiros sinais da toxicidade dada por um extrato é a perda de peso corporal e dos órgãos.O ECV, nas concentrações empregadas, não interferiu no EG quando preparado como uma RP liquida em comparação com o veículo (água). O extrato não alterou nenhum dos parâmetros bioquímicos como pH, quantidade de H+ e peso do suco gástrico, no modelo de ligadura do piloro. O ECV não preveniu a formação de úlceras no modelo de piroxican, mas evitou a formação de lesões causadas por etanol nas doses de 500 e 1000 mg/kg. Esse efeito desapareceu quando o etanol foi empregado duas horas após o pré-tratamento com ECV na dose de 1000 mg/kg. No modelo de úlcera crônica o ECV, nas doses de 500 e 1000 mg/kg, foi capaz de diminuir significativamente as lesões causadas pelo ácido acético, não alterando no entanto, a quantidade de EGF produzida na zona de cicatrização, quando comparados ao controle água. Além disso, o tratamento prolongado com o ECV na dose de 500 mg/kg alterou significativamente a evolução do ganho de peso desses animais. Em conclusão, o ECV, como complemento alimentar, pode ser uma alternativa no tratamento da úlcera péptica gástrica / Abstract: About 10%of the world¿s population suffer from peptic ulcer, within this percentage we find thousands of Brazilians. This pathology is caused by an unbalance between the protection and attack mechanisms of the stomach lining, and is the result of the association of various endogenous attack factors (pepsin, acid, bile), exogenous factors pertaining to life style (stress, smoking, alcohol intake, continuous use of non-steroidal anti-inflammatory drugs, ingestion of certain types of food and the presence of Helicobacter Pylori) and genetic predisposition. Nowadays, the therapeutic methods used for the treatment of the lesions are: Anti-acids, anti-cholinergic, antagonist H2 receptors for histamine, proton bombs; certain surgical procedures are also applied, though much less frequently. Any therapeutic method that involves the use of one or more of the drugs and/or procedures above mentioned may cause some side effects and is not necessarily effective. The use of medicinal plants in the treatment of diseases has been developing over the past decade. Some plants have an anti-ulcer activity. There is evidence that the Chlorella vulgaris algae may modify cellular immune response, and there is also evidence to its anti-tumor, anti-metastasis, anti-ulcer activity. The objective of this present study was to evaluate the anti-ulcer activity of the Chlorella vulgaris algae acute models of ulcer induction and also in one chronic model of ulcer induction. Wistar rats were used to determine gastric emptying (GE) and in models of ulcer induced by ethanol and acetic acid, while swiss mice were used for the piloro ligature and piroxicam ulcer induction models. In order to evaluate the effect of the Chlorella vulgaris extract (ECV) on gastric emptying (GE) a liquid proof meal (PM) with the extract in the concentration of 50mg/l and 100mg/l was usedIn the study of the acute piloro ligature, ethanol and piroxicam models, and in the chronic model, dosages of 250, 500 and 1000mg/kg of ECV were used in the prevention and treatment of the lesions. In the chronic model the fraction of acetate obtained from the ECV in the dosage of 5mg/100g was also used, and the amount of epidermal growth factor (EGF) produced in the region of the ulcer was measured. The toxicity study of the ECV was done by measuring the weight gain of the rats and the weight of their organs i.e. kidneys, lungs, liver, and heart, once the first signs of toxicity by an extract are loss of body and organ weight. The ECV, in the concentration used, did not interfere with the GE when prepared as a liquid PM in comparison to the vehicle (water). The extract did not alter any of the biochemical parameters such as pH, amount of H+ and weight of the gastric juice in the piloro ligature model. The ECV did not prevent the formation of ulcer in the piroxicam model, but it prevented the formation of lesions caused by ethanol in the dosage of 500 and 1000mg/kg. This effect disappeared when ethanol was ministered two hours after the pre-treatment with ECV in the dosage of 1000mg/kg. The chronic ulcer induction model the ECV, in the dosage of 500 and 1000mg/kg, was able to significantly lessen the lesions caused by acetic acid, not altering, however, the amount of EGF produced in the scar tissue area when compared to the water control. Furthermore, the long-term treatment with ECV in the dosage of 500mg/kg significantly altered the evolution of weight gain of these animals. In conclusion, the ECV, as a dietary complement, may be an alternative in the treatment of gastric peptic ulcer / Mestrado / Fisiologia / Mestre em Biologia Funcional e Molecular

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