Littérature scientifique sur le sujet « Ph gastrico e duodenale »
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Articles de revues sur le sujet "Ph gastrico e duodenale"
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Van Duijn, B., D. L. Ypey, J. de Goede, A. A. Verveen et W. Hekkens. « A model study of the regulation of gastric acid secretion ». American Journal of Physiology-Gastrointestinal and Liver Physiology 257, no 1 (1 juillet 1989) : G157—G168. http://dx.doi.org/10.1152/ajpgi.1989.257.1.g157.
Texte intégralRésumé :
A computer simulation model is presented of the gastric phase regulation of gastric acid secretion in humans. The model is based on experimental data from the literature and includes terms representing gastric pH and gastric volume-dependent gastrin secretion, gastrin-dependent acid secretion, food storage in the stomach, and gastric emptying. We have explored the predictive value of the model in assessing the relative importance of gastric pH-dependent and gastric volume-dependent acid secretion mechanisms under various conditions. Similarly we have studied the role of gastric acid deregulation in achlorhydria, the Zollinger-Ellison syndrome, and duodenal ulcer, and the influence of the antacid drugs cimetidine and ranitidine under duodenal ulcer conditions. Model analysis of normal gastric acid regulation suggests that gastric volume-controlled acid secretion is of major importance during eating and predicts that pH-dependent gastrin secretion is of major importance in preventing excessively low pH levels between meals and during the night.
2
Woodtli, W., et C. Owyang. « Duodenal pH governs interdigestive motility in humans ». American Journal of Physiology-Gastrointestinal and Liver Physiology 268, no 1 (1 janvier 1995) : G146—G152. http://dx.doi.org/10.1152/ajpgi.1995.268.1.g146.
Texte intégralRésumé :
In this study, we examined the potential influence of duodenal pH in regulating the occurrence of the interdigestive migrating myoelectric complex (IMMC). Fasting gastroduodenal motility, duodenal pH, and plasma motilin were studied in 15 healthy subjects. During phase I, duodenal pH remained stable at 7 +/- 0.2. Phase II was accompanied by a lowering of duodenal pH, which fluctuated between 2.0 and 7.5. During late phase II, the duodenal pH increased to 6.9 +/- 0.3 and remained in the alkaline range during phase III. In six of 46 episodes of the IMMC, the occurrence of gastric phase III was delayed. This was associated with a persistently low duodenal pH (< 4) during late phase II. Despite a normal cyclic increase of plasma motilin, no gastric phase III activity was observed until the duodenal pH exceeded 7.0. Further studies showed that lowering of duodenal pH by intraduodenal perfusion of HCl prevented the occurrence of gastric phase III. We concluded that regularity of IMMC is governed by duodenal pH. An alkaline pH is essential for the initiation of gastric phase III; lowering of duodenal pH prevents its occurrence despite normal cyclic increase of plasma motilin.
3
Nylander, O., G. Flemstrom, D. Delbro et L. Fandriks. « Vagal influence on gastroduodenal HCO3- secretion in the cat in vivo ». American Journal of Physiology-Gastrointestinal and Liver Physiology 252, no 4 (1 avril 1987) : G522—G528. http://dx.doi.org/10.1152/ajpgi.1987.252.4.g522.
Texte intégralRésumé :
Gastric and duodenal secretions of HCO3- were studied simultaneously in chloralose-anesthetized cats. The adrenals were ligated, and the cervical vagal as well as the abdominal splanchnic nerves were cut. Gastric secretions of H+ and HCO3- were calculated from measurements of the pH and PCO2 in the luminal perfusate. A duodenal segment devoid of Brunner's glands and pancreaticobilary secretions was cannulated in situ and the alkaline secretion determined by continuous titration at luminal pH 7.4. Electrical stimulation in the distal direction for 10–15 min of the cervical vagal nerves resulted in a 6- to 10-fold increase in gastric H+ and in a 20–60% rise in gastric HCO-3 secretion. Duodenal HCO3- secretion increased by 65–155%. Gastric basal secretions of H+ and HCO3- were not affected by atropine or hexamethonium, but both agents inhibited basal duodenal HCO3- secretion. Hexamethonium abolished and atropine reduced the rise in all secretions in response to vagal nerve stimulation. Thus gastroduodenal mucosal HCO3- secretion is stimulated by vagal mechanisms involving action on nicotinic as well as on muscarinic receptors and possibly also noncholinergic neurotransmission.
4
Meert, Kathleen L., Mary Caverly, Lauren M. Kelm et Norma A. Metheny. « The pH of Feeding Tube Aspirates From Critically Ill Infants ». American Journal of Critical Care 24, no 5 (1 septembre 2015) : e72-e77. http://dx.doi.org/10.4037/ajcc2015971.
Texte intégralRésumé :
Background The extent to which gastric acid inhibitors and feedings affect gastric pH in infants is unclear. Objectives To compare pH values of gastric aspirates from infants according to use or no use of gastric acid inhibitors and feedings. Methods Colorimetric pH tests were used to measure the pH of aspirates from feeding tubes in 54 critically ill infants; 29 of the gastric aspirates were from infants who did not receive acid inhibitors or feedings, 13 were from infants who received acid inhibitors but no feedings, 3 were from infants who received feedings but no acid inhibitors, and 5 were from infants who received both acid inhibitors and feedings. The remaining 4 feeding tubes were in nongastric sites. Results Individual pH readings of 5.5 or less were found in 97% of the gastric aspirates from infants with no recent feedings or acid inhibitors, 77% of the gastric aspirates from infants who received acid inhibitors, and 67% of the gastric aspirates from infants with recent feedings. Among 2 esophageal aspirates and 2 duodenal aspirates, 1 of each type had a pH less than 5.5. A pH cut point of 5.5 or less did not rule out esophageal or duodenal placement. Conclusions The pH of gastric aspirates from critically ill infants is often 5.5 or less, regardless of the use of acid inhibitors, feedings, or both. Most likely a cut point of 5.5 or less would rule out respiratory placement because tracheal pH is typically 6.0 or higher.
5
Marshall, R. E. K., A. Anggiansah, D. K. Manifold, W. A. Owen et W. J. Owen. « Effect of omeprazole 20 mg twice daily on duodenogastric and gastro-oesophageal bile reflux in Barrett’s oesophagus ». Gut 43, no 5 (1 novembre 1998) : 603–6. http://dx.doi.org/10.1136/gut.43.5.603.
Texte intégralRésumé :
Background—Both acid and duodenal contents are thought to be responsible for the mucosal damage in Barrett’s oesophagus, a condition often treated medically. However, little is known about the effect of omeprazole on duodenogastric reflux (DGR) and duodenogastro-oesophageal reflux (DGOR).Aims—To study the effect of omeprazole 20 mg twice daily on DGR and DGOR, using the technique of ambulatory bilirubin monitoring.Methods—Twenty three patients with Barrett’s oesophagus underwent manometry followed by 24 hour oesophageal and gastric pH monitoring. In conjunction with pH monitoring, 11 patients (group 1) underwent oesophageal bilirubin monitoring and 12 patients (group 2) underwent gastric bilirubin monitoring, both before and during treatment with omeprazole 20 mg twice daily.Results—In both groups there was a significant reduction in oesophageal acid (pH<4) reflux (p<0.005) and a significant increase in the time gastric pH was above 4 (p<0.005). In group 1, median total oesophageal bilirubin exposure was significantly reduced from 28.9% to 2.4% (p<0.005). In group 2, median total gastric bilirubin exposure was significantly reduced from 24.9% to 7.2% (p<0.005). Conclusions—Treatment of Barrett’s oesophagus with omeprazole 20 mg twice daily results in a notable reduction in the exposure of the oesophagus to both acid and duodenal contents. In addition, delivery of duodenal contents to the upper gastric body is reduced.
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J, Greffa, Barrionuevo A, Vilcacundo E et Carrillo W. « GASTROINTESTINAL DIGESTION OF KAHAI PROTEIN CONCENTRATE (CARYODENDRON ORINOCENSE KARST) ». Asian Journal of Pharmaceutical and Clinical Research 11, no 6 (7 juin 2018) : 397. http://dx.doi.org/10.22159/ajpcr.2018.v11i6.20374.
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Objective: The aim of this study was to obtain kahai protein concentrate from Caryodendron orinocense karst cultivated in the region Amazonia of Ecuador and characterizes its gastric and duodenal hydrolysates using the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) electrophoresis method and the reversed-phase ultra-high-performance liquid chromatography (RP-UHPLC) method.Methods: Kahai seeds (C. orinocense karst) were utilized to obtain kahai protein concentrate at pH 5.0 using the isoelectric precipitation method and then subject to gastric hydrolysis with pepsin enzyme (2000 U/mg of protein) at pH 1.2, pH 2.0, and pH 3.2 at 37°C for 2 h with agitation in simulated gastric fluids and then to duodenal hydrolysis with pancreatin (mix enzymes) at pH 7.0 at 37°C for 3 h with agitation in simulated intestinal fluid. Gastric and duodenal hydrolysates from kahai were characterized using the SDS-PAGE electrophoresis method and the RP-UHPLC chromatography method.Results: Proteins obtained from kahai (C. orinocense karst) were hydrolyzed with pepsin, only one protein with molecular weight of 100 kDa presented resistance to hydrolysis with pepsin at all pHs assayed. All proteins from kahai protein concentrate were totally hydrolyzed with pancreatin in in vitro conditions.Conclusion: This study suggests that kahai protein concentrates have a high grade of digestibility in vitro when using the gastroduodenal model of digestion. Kahai protein can be a good source of alternative vegetal proteins to be consumed by animals and humans.
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Golubkina, E. V., V. M. Sorokin, A. P. Umerova et N. V. Kamneva. « Acid formation in gastroenterological patients with colonization of the stomach with virulent and non-virulent strains of helicobacter ». Experimental and Clinical Gastroenterology, no 9 (24 mars 2020) : 32–37. http://dx.doi.org/10.31146/1682-8658-ecg-169-9-32-37.
Texte intégralRésumé :
Objective. To prove that increased acid production in patients with gastric ulcer and duodenal ulcer is associated with the impact of the virulent strains of Helicobacter pylori but due not to the persistence of non-virulent strains.Materials and methods. Patients with active gastroduodenal ulcer and patients with active chronic pancreatitis accompanied by the gastritis were compared in the respect of the level of pH in the antrum and corpus gastricum, as well as Helicobacter pylori virulence according to the presence cagA gene, especially in combination with vacA allele s1 / m1 (if any of the strains were found in gastric biopsy specimen).Results. In patients with gastric ulcer the average values of pH were significantly lower, both in the antrum and corpus gastricum, than in patients with chronic pancreatitis accompanied by gastritis. Helicobacter pylori strains were found only in half of the patients, either in the gastric ulcer group or in the group of chronic pancreatitis accompanied by the gastritis. Significant difference was revealed after virulent genes identification: virulent strains prevailed in patients with gastric ulcer and in contrast to the prevalence of non-virulent strains in patients with chronic pancreatitis accompanied by the gastritis (Mann-Whitney test, p = 0.001). Since there is no available data that Helicobacter has an affinity for a highly acidic medium in comparison with moderately acidic medium, it is concluded that just primary colonization of the stomach with virulent strains results in hyperacidity (as the consequence of cytotoxicity) and that persistence of non-virulent strains hardly effects hyperacidity.
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Al-Judaibi, B., N. Chande, G. K. Dresser, N. Sultan et J. C. Gregor. « Gastric Acid-Related Diseases : Focus on Esomeprazole ». Clinical Medicine Insights : Therapeutics 2 (janvier 2010) : CMT.S4500. http://dx.doi.org/10.4137/cmt.s4500.
Texte intégralRésumé :
Esomeprazole (S-omeprazole) is a single optical enantiomer proton-pump inhibitor (PPI) approved for the management of gastro-oesophageal reflux disease, the prevention and treatment of Non-Steroidal Anti-Inflammatory Drugs (NSAID) associated gastric ulcer disease, treatment of duodenal ulcer disease associated with Helicobacter pylori infection, and the treatment of Zollinger-Ellison syndrome. Esomeprazole has been shown to be safe and effective during pregnancy and was introduced to the market in 2001. PPI therapy may interact with clopidogrel by cytocrome 2C19. Clopidogrel is a prodrug which is partially activated by cytochrome 2C19 and esomeprazole is a competitive inhibitor of 2C19. Esomeprazole is more effective than other PPIs in controlling esophageal and gastric pH, but efficacy in symptom relief is less clear.
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Faruwu, Ardilon Raxel, Riami Riami et Fitri Handajani. « Pengaruh Ekstrak Anggur Laut terhadap pH Lambung dan duodenum pada Rattus norvegicus Jantan yang Diinduksi Indometasin ». Jurnal Ilmiah Kedokteran Wijaya Kusuma 9, no 2 (1 octobre 2020) : 170. http://dx.doi.org/10.30742/jikw.v9i2.884.
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Indomethacin is a nonsteroidal anti-inflammatory drugs (NSAIDs) that act to inhibit COX-1. The inhibition of COX-1 leads to inhibition of prostaglandin production. Prostaglandin is a regulator of gastric acid buffer secretion. Inhibition of prostaglandin decrease gastric and duodenum pH and damage the gastric and duodenum. Sea grapes (Caulerpa racemose var. cylindracea) are marcoalgae that contain flavonoids as antioxidants and anti-inflammatory. The aim of this study was to determine the effect of sea grapes on gastric and duodenum pH in rattus norvegicus induced by indomethacin. 32 male Rattus norvegicus were divided into 4 groups. Group K (-) without treatment. Group K (+) was induced by 30 mg/Kg BW indomethacin for 7 days. Group P1 was induced by 30mg/Kg BW indomethacin for 7 days followed by administration of 1g/100g BW sea grape extract for 14 days. Group P2 was induced by 30mg/Kg BW indomethacin for 7 days followed by administration of 2g/100g BW sea grape extract for 14 days. On the 29th day, rats were terminated, gastric and duodenal were isolated then the fluid pH was measured. One-way Anova test obtained p = 0,023. Post hoc test pH Gaster significantly different between group K (-) and K (+) (p= 0,005) and between group K (-) with P2 (p= 0,020). While in group K (+) with P1 and P2 there was no significant difference in pH. Post hoc test of pH duodenum showed no differences in all group. The administration of sea grape extract did not show a differences of the gastric and duodenal pH significantly between rats induced by indomethacin.
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HADJILOUKA, AGNI, PARASKEVAS GKOLFAKIS, APOSTOLIA PATLAKA, ATHENA GROUNTA, GEORGIA VOURLI, SPIROS PARAMITHIOTIS, GIOTA TOULOUMI, KONSTANTINOS TRIANTAFYLLOU et ELEFTHERIOS H. DROSINOS. « In Vitro Gene Transcription of Listeria monocytogenes After Exposure to Human Gastric and Duodenal Aspirates ». Journal of Food Protection 83, no 1 (19 décembre 2019) : 89–100. http://dx.doi.org/10.4315/0362-028x.jfp-19-210.
Texte intégralRésumé :
ABSTRACT The aim of the present study was to assess, for the first time to our knowledge, Listeria monocytogenes CFU changes, as well as to determine the transcription of key virulence genes, namely, sigB, prfA, hly, plcA, plcB,inlA, inlB, inlC, inlJ, inlP, and lmo2672 after in vitro exposure to human gastric and duodenal aspirates. Furthermore, investigations of the potential correlation between CFU changes and gene regulation with factors influencing gastric (proton pump inhibitor intake and presence of gastric atrophy) and duodenal pH were the secondary study aims. Gastric and duodenal fluids that were collected from 25 individuals undergoing upper gastrointestinal endoscopy were inoculated with L. monocytogenes serotype 4b strain LQC 15257 at 9 log CFU·mL−1 and incubated at 37°C for 100 min and 2 h, respectively, with the time corresponding to the actual exposure time to gastric and duodenal fluids in the human gastrointestinal tract. Sampling was performed upon gastric fluid inoculation, after incubation of the inoculated gastric fluids, upon pathogen resuspension in duodenal fluids and after incubation of the inoculated duodenal fluids. L. monocytogenes CFU changes were assessed by colony counting, as well as reverse transcription quantitative PCR by using inlB as a target. Gene transcription was assessed by reverse transcription quantitative PCR. In 56% of the cases, reduction of the pathogen CFU occurred immediately after exposure to gastric aspirate. Upregulation of hly and inlC was observed in 52 and 58% of the cases, respectively. On the contrary, no upregulation or downregulation was noticed regarding sigB, prfA, plcA, plcB, inlA, inlB, inlJ,inlP, and lmo2672. In addition, sigB and plcA transcription was positively and negatively associated, respectively, with an increase of the pH value, and inlA transcription was negatively associated with the presence of gastric atrophy. Finally, a positive correlation between the transcriptomic responses of plcB, inlA, inlB, inlC, inlJ, inlP, and lmo2672 was detected. This study revealed that the CFU of the pathogen was negatively affected after exposure to human gastroduodenal aspirates, as well as significant correlations between the characteristics of the aspirates with the virulence potential of the pathogen.
Thèses sur le sujet "Ph gastrico e duodenale"
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Coelho, Cristina Bueno Terzi. « Influencia da ranitidina e pantoprazol no pH gastrico em pacientes septicos ». [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/308815.
Texte intégralRésumé :
Orientadores: Desanka Dragosavac, Nelson Adami AndreolloTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas
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Resumo: Objetivo: Avaliar a capacidade da ranitidina e do pantoprazol em elevar e manter o pH gástrico = 4 em pacientes sépticos. Material e métodos: Foram estudados 20 pacientes internados na UTI, com diagnóstico de sepse/choque séptico, em ventilação mecânica. Dez receberam ranitidina (50 mg em bolo 8/8 horas) e outros 10 pacientes receberam pantoprazol 40 mg, em bolo de 12/12 horas. O pH gástrico foi medido de forma contínua por 48 horas. Foi realizada endoscopia digestiva alta antes e após o estudo e encaminhado para análise um fragmento obtido por biópsia e pesquisa de Helicobacter pylori. Resultados: O grupo ranitidina permaneceu por 46,27 ± 38,21 % e o grupo do pantoprazol 81,57 ± 19,65% do tempo estudado com pH gástrico = 4 (p=0,04). No subgrupo de ranitidina sem atrofia gástrica o pH esteve = 4 em 15,97 % e em cinco casos com atrofia em 79,44% do tempo estudado. No subgrupo do pantoprazol que realizou biópsia, quatro pacientes não apresentavam atrofia gástrica e o tempo de pH =4 foi de 81,17%. Em um paciente com atrofia da mucosa gástrica, o pH gástrico se manteve =4 durante todo o período do estudo. Conclusões: A ranitidina intravenosa, usada para profilaxia de úlcera de estresse, não foi capaz de manter o pH gástrico acima de quatro em pacientes sépticos. Todos os casos do grupo ranitidina, onde o pH foi mantido acima de quatro, apresentavam hipotrofia ou atrofia gástrica. O pantoprazol manteve o pH acima que quatro por período maior de tempo durante o estudo
Abstract: Purpose: To evaluate whether ranitidine and pantoprazole are able to maintain gastric pH = 4 in septic patients. Material and methods: Twenty intensive care unit (ICU) patients from a University teaching hospital, with sepsis. Ten patients received ranitidine (50 mg as an intermittent bolus t.i.d.) and ten received pantoprazole (40 mg as an intermittent bolus b.i.d.). Gastric pH was measured continuously for 48 hours. Endoscopy of the upper digestive tract, gastric biopsy and investigation for Helicobacter pylori were carried out prior to and at the end of the study. Results: pH values = 4 were maintained for 46.27 ± 38.21 % and 81.57 ± 19.65% of observation time in the ranitidine and pantoprazole groups, respectively (p=0.04). In the subgroup of ranitidine without atrophy gastric pH was = 4 at 15.97% and in five cases with atrophy in 79.44% of the time studied observation time. In the subgroup of pantoprazole who underwent biopsy, four patients did not have mucosal atrophy and gastric pH was = 4 for 81.17% of the time. In one patient with mucosal atrophy, gastric pH remained = 4 for the entire study period. Conclusions: Intravenous ranitidine was unable to maintain gastric pH above 4 in septic patients. All cases in the ranitidine group in whom pH remained above 4 were found to have mucosal gastric hypotrophy or atrophy. Pantoprazole successfully maintained pH above 4
Doutorado
Pesquisa Experimental
Doutor em Cirurgia
2
Januario, Netto Eden. « Sistema com sensor de fibra optica para a medição de ph gastrico ». [s.n.], 1994. http://repositorio.unicamp.br/jspui/handle/REPOSIP/260391.
Texte intégralRésumé :
Orientador: Eduardo Tavares Costa, Wang BisengTese. (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica
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Resumo: A construção e o desempenho de um sistema com sensor de fibra óptica para medição do pH numa faixa ampla é apresentada. A construção do sensor é baseada no emprego de dois indicadores colorimétricos de pH, fornecendo uma sensibilidade na faixa de pH 1 a pH 7, com uma precisão de 0,1 unidades de pH. Essa faixa se estende até pH 9, mas com uma precisão menor. A aplicação principal deste protótipo é a monitoração do pH gástrico. o sistema é baseado na imobilização conjunta dos indicadores colorimétricos e micropartículas de dispersão em microesferas de gel de "polyacrylamide". O sensor é construído com uma única fibra óptica de plástico de o,25mm, um divisor de luz com fibra óptica, uma lâmpada sub-miniatura de tungstênio halogenado, um fotodetector com grade holográfica e CCD, conectado a um computador, responsável pela análise espectral em duas faixas de comprimentos de onda. O computador apresenta graficamente o valor do pH por um período de até 24 horas. O sistema apresenta uma estabilidade 0,2 unidades de pH por 24 horas, tempo de resposta de alguns minutos e foi testado em amostras de suco gástrico e em um animal
Abstract: The construction and perfomance of a fiber-optic broad-range pH sensor is described. The general construction of the sensor is based on two immobilized colorimetric indicators, providing a sensitivity over the pH range of 1 to 7 with a precision of 0.1 pH unit. The range extends to pH 9 with less precision. The primary objective of the design is for gastric measurements. The system is based on absorbance dyes bound to polyacrylamide gel containing light-scattering particles. The sensor is constructed on a single 0.25mm diameter plastic optical fiber. The optical system consists of a sub-miniature tungsten lamp, fiber-optic splitter, and CCD - grating detector connected to a computer for spectral analysis, using two wavelength regions. The computer displays the pH graphically over 24 hours. The system shows stability within 0,2 pH unit over 24 hours, response time of a few minutes and has been tested with gastric juice samples and in an animal
Doutorado
Engenharia Biomedica
Doutor em Engenharia Elétrica
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David, Flavia Lucia. « Estudo sobre a influencia do pH gastrico na absorção de metronidazol : implicações clinicas para a erradicação do Helicobacter Pylori ». [s.n.], 1998. http://repositorio.unicamp.br/jspui/handle/REPOSIP/310128.
Texte intégralRésumé :
Orientador : Jose Pedrazzoli JuniorDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
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Resumo: A adição de omeprazol na terapia tríplice oral para erradicação do Helicobacter pylori é sugerido para reduzir os sintomas da úlcera, bem como a resistência da bactéria ao metronidazol. O propósito deste estudo foi o de investigar a farmacocinética do metronidazol com bloqueio da secreção ácida por meio da administração do omeprazol, administrados por via oral. O protocolo clínico que consiste de duas fases, com intervalos de vinte e um dias entre elas, foi aprovado pelo comitê de Ciências Médicas da Universidade São Francisco. Catorze voluntários adultos sadios, do sexo masculino, receberam uma dose única de 400mg de metronidazol, em diferentes fases do ensaio clínico, antes e depois do tratamento com omeprazol. Foram colhidas amostras de sangue dos voluntários em intervalos padronizados, dentro do período de vinte e quatro horas, após a administração de metroni4azol via oral em cada fase do estudo. As amostras foram processadas adequadamente e as concentrações plasmáticas de metronidazol foram mensuradas por cromatografia líquida de alta eficiência (HPLC), com fase reversa e detecção ultravioleta, segundo método proposto por Muscará & De Nucci (1991). Nossos resultados indicaram que o bloqueio da secreção ácida com omeprazol em voluntários sadios não altera a farmacocinética do metronidazol
Abstract: The addition of omeprazole to the classical triple therapy for eradication of He/icobacter pylori is suggested to enhance compliance through reducing ulcer symptoms and side effects, as well as overwhelming metronidazole resistance. The aim of this study was to investigate the effects af a tive day administration period of omeprazole on metronidazole pharmacokinetics. Fourteen healthy male volunteers were selected. Plasma concentrations of metronidazole and its hydroxy-metabolite were measured by reversed phase HPLC with ultraviolet detection. Our results indicate that short-term treatment with omeprazole in healthy volunteers does not alter the extent or the rate of metronidazole absorption, and does not affect metronidazole clearance
Mestrado
Farmacologia
Mestre em Ciências
4
MASTROMAURO, Marina. « Variazioni circadiane del Ph gastrico e duodenale in pazienti affetti da pancreatite cronica ». Doctoral thesis, 2007. http://hdl.handle.net/11562/338051.
Texte intégralRésumé :
Il PH duodenale e’ soggetto a fisiologiche variazioni circadiane ad opera di vari fattori. La corretta modulazione dell’ andamento di tali variazioni intraluminali del PH e’ particolarmente importante ai fini di un normale svolgimento dei processi digestivi ed in particolare influenza in maniera significativa sia la solubilizzazione dei grassi sia l’attivita’ degli enzimi pancreatici, quale ad esempio la lipasi che esercita la sua funzione all’interno di un ristretto range di pH ( 4 – 6 ) venendo irreversibilmente degradata per valori inferiori o in gran parte inattivata per valori superiori (1,2,3,4).
L’alterazione dei meccanismi modulatori della concentrazione duodenale di idrogenioni che conduca ad un abbassamento del PH intraluminale puo’condurre quindi ad alterazione dei processi digestivi e di conseguenza a maldigestione.
Diversi studi hanno riportato che in corso di pancreatite cronica il pH intraduodenale e’ significativamente inferiore rispetto ai controlli sani (1,5,6).
Tra i meccanismi responsabili di una alterata modulazione della concentrazione intraluminale di idrogenioni ruolo preminente sembrano avere la secrezione pancreatica di bicarbonati, in grado di esercitare l’effetto tampone , la secrezione acida gastrica e il tempo di svuotamento gastrico, come fattori determinanti il carico di idrogenioni in afflusso al lume duodenale.
Diversi sono gli studi , pur con risultati non univoci, che hanno approfondito tali meccanismi.
Relativamente alla secrezione acida gastrica alcuni autori sostengono che, in corso di pancreatite cronica, l’ipersecrezione possa determinare un significativo carico di idrogenioni nel duodeno e quindi abbassare il pH; a sostegno di questa ipotesi e’ la dimostrazione di ipersecrezione acida sia basale che dopo stimolo ( pasto o pentagastrina), riscontrata in studi effettuati su aspirato gastrico, ed il riscontro di alcuni rilievi ph-metrici delle 24h che dimostrano una aumentata acidificazione gastrica post-prandiale (7-11). Altri autori, peraltro precedentemente, non hanno confermato tali dati non rilevando in realta’ differenze statisticamente significative nella secrezione acida gastrica tra pazienti affetti da pancreatite cronica e controlli sani quando non addirittura non e’ stato osservato un trend inverso (2,12-14).
I risultati degli studi possono peraltro risentire in maniera determinante delle scelte metodologiche nella selezione dei pazienti affetti da pancreatite cronica, come la presenza di insufficienza enzimosecretiva o l’assunzione di alcool, e nella modalita’ di misurazione del pH gastrico e duodenale.
Relativamente alla secrezione pancreatica di bicarbonati , la sua riduzione in corso di pancreatite cronica comporta sicuramente una insufficiente neutralizzazione dell’acidita’gastrica e contribuisce quindi ad abbassare il pH duodenale. (4,15)
Anche lo svuotamento gastrico, modulando i tempi di afflusso del carico di idrogenioni, e, piu’ in generale, la complessa regolazione neuro-ormonale della motilita’ gastrointestinale che concorre in condizioni fisiologiche a mantenere in un range ottimale il ph duodenale, possono assere alterati in corso di pancreatite cronica con insufficienza esocrina.(16-20)
Un ulteriore contributo conoscitivo e’ stato ottenuto con piu’ moderne metodiche di studio e cioe’ con la misurazione simultanea del pH gastrico e duodenale mediante pHmetria. In due studi tale rilievo e’ stato limitato al post prandium, per poche ore (5,6). Altri autori, invece, hanno esteso alle 24 0re la misurazione simultanea del pH gastrico e duodenale con monitoraggio continuo su un campione peraltro relativamente limitato di pazienti (15); pur non emergendo differenze significative nel pH gastrico e duodenale tra pazienti affetti da pancreatite cronica e controlli, la significativita’ statistica si raggiungeva quando si analizzava il tempo totale di esposizione a ph acido, decisamente piu’ lungo nei pazienti affetti da pancreatite cronica rispetto ai controlli.Non disponibile
5
BALLA, ANDREA. « Valutazione pH-manometrica nei pazienti obesi candidati a Sleeve Gastrectomy o bypass gastrico per via laparoscopica ». Doctoral thesis, 2021. http://hdl.handle.net/11573/1500997.
Texte intégralRésumé :
Background: Aim is to evaluate the impact of laparoscopic sleeve gastrectomy (LSG) and gastric bypass (LGB) on gastroesophageal reflux disease (GERD) before and after surgery.
Methods: Before surgery, GERD was evaluated by Modified Italian Gastroesophageal reflux disease-Health-Related Quality of Life (MI-GERD-HRQL) questionnaire, manometry, pH-metry, endoscopy and Rx-esophagogram. Based on these exams, patients without GERD underwent LSG and patients with GERD underwent LGB. These exams were repeated 12 months after surgery.
Results: Thirteen and 6 patients underwent LSG and LGB, respectively. After LSG, all pH-manometry parameters worsened, with statistically significant difference in median DeMeester score (5.7 vs. 22.7, p=0.0026). De novo GERD occurred in 9 patients (69.2%), with erosive esophagitis in one. No statistically significant differences were observed at endoscopy and Rx esophagogram findings. The median MI-GERD-HRQL score improved from a median of 3 to 0. Overall, nine patients underwent LGB, but three were lost at follow-up. Preoperative pH-manometry changed the surgical indication from LSG to LGB in 7 out of 9 patients (77.8%). Six patients who underwent LGB completed the study, and at pH-manometry, statistically significant differences were observed in percentage of total acid exposure time, number of reflux episodes lasting >5 minutes and DeMeester score (93.8 vs. 3.6, p=0.009). No statistically significant differences were observed at endoscopy and Rx-esophagogram findings. The median MI-GERD-HRQL score improved from a median of 6.5 to 0.
Conclusions: LSG has a negative impact on GERD, even in patients without preoperative GERD. LGB was proved to be the intervention of choice in patients with GERD. Preoperative pH-manometry may identify patients with silent GERD, to candidate them to LGB rather than LSG. Preoperative endoscopy, Rx esophagogram and GERD symptoms are not sufficient to decide the most appropriate intervention in obese patients. pH-manometry should be used more liberally to establish the correct surgical indication on objective grounds.
Chapitres de livres sur le sujet "Ph gastrico e duodenale"
1
Weinlich, Michael, C. Baumstark, H. D. Becker et M. J. Sessler. « Humane duodenale Zellkulturen in Vesikelform : Ein geeignetes Modell zur Untersuchung der Ca2+- und pH-Regulierung ». Dans Deutsche Gesellschaft für Chirurgie, 371–75. Berlin, Heidelberg : Springer Berlin Heidelberg, 1999. http://dx.doi.org/10.1007/978-3-642-60133-0_71.
Texte intégralActes de conférences sur le sujet "Ph gastrico e duodenale"
1
Wu, Haizhou, Cecilia Tullberg et Ingrid Undeland. « Formation of reactive aldehydes (MDA, HHE, HNE) during in vitro digestion of cod muscle : role of hemoglobin from trout and bovine sources ». Dans 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/jkrq2423.
Texte intégralRésumé :
Heme-mediated oxidation in red meat is described as one of the potential routes to meat-induced colorectal cancer, which is linked to the ability of this reaction to continue also during gastrointestinal (GI) digestion while generating reactive aldehydes such as e.g. malondialdehyde (MDA), 4-hydroxy-2-nonenal (HNE) and 4-hydroxy-trans-2-hexenal (HHE). Very little is however known about the specific forms of heme being present at different stages of the GI-tract, and how mammal heme-proteins compare to those of for example fish with respect to their lipid pro-oxidative activity under GI-conditions. In the present study, the degradation of trout and bovine Hb and their pro-oxidant activities towards washed cod muscle mince were studied using in vitro GI digestion models. When the two Hb´s were subjected only to the pH-cycle of the GI-digestion model (pH 7→6→3→7) at 37°C, metHb formation increased following the initial gastric acidification to pH 6, especially for trout Hb. Subsequent acidification to pH 3 promoted Hb unfolding and partial or complete loss of the heme group. When digesting the Hb´s in the full digestion model, i.e. with enzymes and bile present, high-performance size-exclusion chromatography (HP-SEC) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of digests showed more extensive Hb-degradation in the gastric phase compared to in the duodenal phase. When washed cod muscle was digested without/with Hb, a strong pro-oxidative effect was seen from the Hb´s, resulting in high MDA, HHE, HNE formation which peaked at the end of the gastric phase. Slightly higher oxidation was seen with trout Hb, especially with respect to HHE. Results thus indicate that partially degraded Hb, and/or free hemin -both from mammal and fish sources- were highly pro-oxidative towards PUFA-rich lipids under GI-conditions, especially in the gastric phase.