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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.
91

AÃÃo AntiespasmÃdica e Anti-inflamatÃria do Cinamato de Metila em Trato Gastrintestinal de Ratos Submetidos a Modelo de Colite por Ãcido AcÃtico

Francisco Josà Batista de Lima JÃnior 21 February 2013 (has links)
nÃo hà / Previamente demonstrou-se que o Ãleo essencial de Ocimum micranthum (OEOM) e seu constituinte majoritÃrio, cinamato de metila (CM), tÃm aÃÃes miorrelaxante e antinflamatÃria em tecidos traqueais de ratos, e efeito antinociceptivo em camundongos. O objetivo deste estudo foi avaliar o potencial antiespasmÃdico e anti-inflamatÃrio do CM no trato gastrintestinal de ratos submetidos a modelo de colite induzida por Ãcido acÃtico. OEOM inibiu contraÃÃes induzidas por carbamilcolina (CCh; 1 M) e KCl (60 mM) em tiras de fundo de estÃmago com CI50 de 91,9 g/mL e 46,8 g/mL, respectivamente, e reduziu significativamente o tÃnus basal e amplitudes de contraÃÃes espontÃneas de duodeno. CM, em conformaÃÃes isomÃricas (Z)- ou (E)-, tambÃm inibiu essas respostas induzidas por CCh e KCl em fundo, antro, duodeno e cÃlon, sem diferenÃas nos efeitos dos isÃmeros em cada segmento. CM comeÃa a inibir as contraÃÃes induzidas por CCh em concentraÃÃo mais baixa que KCl, contudo com potÃncia menor se comparado aos efeitos da atropina. (E)-CM inibe contraÃÃes dependentes dos estoques intracelulares de cÃlcio, e seu efeito inibitÃrio parece nÃo depender da aÃÃo da Ãxido nÃtrico sintase ou da abertura de canais de potÃssio. Analisadas em microscÃpio confocal, cÃlulas de cÃlon dissociadas a fresco tiveram nÃvel citossÃlico de cÃlcio reduzido para 60% do basal apÃs exposiÃÃo a (E)-CM (600M). Avaliando a pressÃo intragÃstrica in vivo, uma dose de (E)-CM 50 mg/kg nÃo afeta amplitude das contraÃÃes gÃstricas, mas se repetida apÃs 30 minutos, as diminui por atà 10 minutos. A induÃÃo de colite foi atravÃs de instilaÃÃo de Ãcido acÃtico a 5% via retal. O grupo sham recebeu instilaÃÃo apenas de salina, e os grupos tratados, alÃm da instilaÃÃo de Ãcido receberam (E)-CM 50 mg/kg/dia ou prednisolona 1 mg/kg/dia durante trÃs dias. A instilaÃÃo com Ãcido acÃtico induziu colite confirmada por alteraÃÃo macroscÃpica, leucocitose, aumento de interleucina-1 tecidual e dÃficit funcional de resposta dependente de canais para cÃlcio operados por voltagem. Esses parÃmetros foram revertidos pelos tratamentos com (E)-CM e prednisolona. Portanto, OEOM e CM apresentam aÃÃo antiespasmÃdica em trato gastrintestinal de ratos in vitro. O efeito do CM passa pela reduÃÃo dos nÃveis intracelulares basais de cÃlcio e independe da participaÃÃo da enzima Ãxido nÃtrico sintase e de canais de potÃssio. CM possui aÃÃo anti-inflamatÃria de magnitude comparÃvel à prednisolona. / It was previously shown that the essential oil of Ocimum micranthum (EOOM), and its major constituent, methyl cinnamate (MC), have myorelaxant action on tracheal smooth muscle, airway anti-inflammatory and anti-nociceptive on rodents. The present work aimed to evaluate the antispasmodic and anti-inflammatory potential of MC on gastrointestinal tissues from rats subjected to acetic acid-induced colitis model. EOOM inhibited carbamylcholine- (CCh; 1 M) and KCl-induced (60 mM) contractions in stomach fundus strips with IC50 of 91.9 g/mL and 46.8 g/mL, respectively. It significantly reduced the basal tonus as well as the spontaneous contractions in duodenum. The isomers (Z)- or (E)-MC also inhibited CCh and KCl contractions in fundus, antrum, duodenum and colon strips, without differences between the effects caused by the isomers in each segment. MC significantly inhibited CCh in lower concentration in comparison with KCl, but with decreased potency if compared to atropine. (E)-MC inhibited intracellular calcium stores-dependent contractions, and its effect seems not to involve the activity of the nitric oxide synthase or the opening of potassium channels. Analyzed by confocal microscopy, freshly dissociated colon cells showed reduced basal cytosolic calcium levels (60%) after (E)-MC (600 M) exposure. In vivo, a first dose of (E)-MC (50 mg/kg) did not affect gastric contractions, but following a second dosage (50 mg/kg) administered a half an hour later, it reduced gastric contractions for 10 minutes. Colitis was induced by rectal instillation of acetic acid 5%. Sham group received only saline in instillation, while treated groups, beyond acid instillation, received (E)-CM 50 mg/kg/day p.o. or prednisolone 1 mg/kg/day p.o. during three days. Acetic acid instillation induced colitis that was macroscopically confirmed, leukocytosis, increased interleucin-1β and functional response loss due to voltage operated calcium channel disorder. These parameters were recovered by (E)-MC or prednisolone. Therefore, EOOM and CM have in vitro antispasmodic effect on rat gastrointestinal tract. The effect of CM involves reduction of the intracellular levels of calcium being independent of the nitric oxide synthase and potassium channels. CM has anti-inflammatory action comparable to prednisolone in magnitude.
92

Esvaziamento gastrico de liquidos em ratos submetidos a ligadura do ducto biliar

Ribeiro, Antonio Fernando, 1948- 10 October 1999 (has links)
Orientador: Edgard Ferro Collares / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-07-28T14:04:14Z (GMT). No. of bitstreams: 1 Ribeiro_AntonioFernando_D.pdf: 4924120 bytes, checksum: a2847d6429aeeed6598aa46a5ec0f9e6 (MD5) Previous issue date: 1999 / Resumo: O objetivo deste estudo foi avaliar o esvaziamento gástrico (EG) de líquidos em ratos com ligadura do ducto biliar. Numa primeira fase (etapa I), 18 animais foram distribuídos em 2 subgrupos: com ligadura do dueto biliar (L) e simulado (S). Após duas semanas recebendo ração com 10% de gordura, avaliou-se o modelo de obstrução da via biliar do ponto de vista morfológico (macroscópico e histológico), bioquímico (níveis séricos de bilirrubinas, transaminases, fosfatase alcalina, amilase e gama-glutamil-transferase) e funcional (esteatócrito ácido do conteúdo do ceco-apêndice do rato). Numa segunda fase (etapa TI), 132 animais foram distribuídos em 5 grupos de acordo com a refeição de prova líquida ( RP): Grupo salina (GS) em que a RP foi NaCI 0.9% (p/v), com 36 animais divididos nos subgrupos controle C, S e L, com 12 animais cada; grupos maionese a 3% e 6% (GM3% e GM6%) e grupos glicose a 5% e 10% (GG5% e GGI0%), que foram divididos em subgrupos S e L, também com 12 animais cada. Nesta etapa, após 2 semanas recebendo ração comercial Labina (Purina), determinouse a retenção gástrica (RG) das 5 refeições de prova e repetiram-se as determinações realiza~as na etapa I, com exceção do esteatócrito ácido. O estudo do EG foi realizado nos animais em jejum alimentar de 24 horas, recebendo água ad libitum, administrando a RP segundo técnica padronizada e utilizando o'volume de 2mI/g de peso do animal. Na análise estatística, empregou-se o teste não paramétrico de Mann-Whitney (K=2) e Kruskal-Wallis (K ~ 3), sendo estabelecido o valor de a = 0,05. Havendo diferença significativa no teste de Kruskal-Wallis, aplicou-se o teste de comparações múltiplas na diferenciação entre os pares (a = 0,02). Os resultados da etapa I demonstraram a eficácia da ligadura do ducto biliar, sob os aspectos analisados. Destacaram-se os fatos: 1- não foram observadas diferenças significativas nos níveis de amilase sérica na comparação entre os subgrupos; 2- os animais com ligadura do ducto biliar apresentaram valores de esteatócrito significativamente maiores (mediana = 58,5%) em relação ao subgrupo simulado (mediana = 8%). Os resultados da etapa II demonstraram ganho de peso significativamente menor nos animais com ligadura do ducto biliar e valores de peso úmido, seco e conteúdo líquido do fígado, significativamente maiores nos animais com ligadura do ducto biliar em relação aos simulados. Os resultados das determinações bioquímicas realizadas nesta etapa não diferiram daqueles obtidos na etapa I. O esvaziamento da RP salina não foi influenciado pela ligadura do ducto biliar (mediana da RG = 38,5%) em relação ao subgrupo controle ( mediana da RG = 36,3%) e subgrupo simulado (mediana da RG = 36,9%). Com relação as RP de maionese a 3 e 6%, observaram-se valores de RG significativamente menores nos subgrupos com ligadura (mediana da RG do GM3 = 30,4% e do GM6 = 35,4%), quando comparados com os subgrupos simulados (mediana da RG do GM3 = 38,6% e do GM6 = 47,3%). Por outro lado, a RG da RP de glicose a 5% não mostrou diferença significativa no subgrupo com ligadura (mediana da RG do GG5 = 45,2%) em relação ao simulado (mediana da RG do GG5 = 41,5%), mas na RP dê glicose a 10% foram observados valores significativamente maiores da RG nos animais do subgrupo com ligadura do ducto biliar (mediana da RG do GGI0 = 66,8%) quando comparados com o subgrupo simulado (mediana da RG do GGlO = 53,6%). Concluiu-se que, em ratos, a ausência de fluxo biliar para o intestino delgado aumentou o EG de gorduras e retardou o EG de glicose a 10%, quando estes macronutrientes foram administrados na forma de refeições líquidas / Abstract: The objective of this study was to evaluate gastric emptying (GE) of liquids in rats with bile duet ligature. In the first phase (step 1), 18 animals were distributed in 2 subgroups: with bile duet ligature (L) and sham (S). After two weeks receiving ration with 10% fat, the obstruction model of the biliary path was evaluated as to morphology (macroseopic and histological), bioehemistry (plasma levels of bilirubin, aminotransferases, alkaline phosphatase, amylase and y-glutamil-transpeptidase) and function (steatocrit acid of the rats' eeeo-appendix content). In the second phase (step 2), 132 animals were distributed in 5 groups according to the liquid test meal (LTM) Saline group (SG), in which the LTM was 0.9% NaCI, with 36 animals divided into control C, S and L subgroups, with 12 animals in each, the mayonnaise groups at 3% and 6% (MG3 and MG6) and glucose groups at 5% and 10% (GG5 and GGlO), which were divided into subgroups S and L, also with 12 animals in each. In this phase, after 2 weeks receiving commercial ration, Labina (Purina), gastrie retention (GR) for the 5 meals tested was determined and the procedures of phase I were repeated, with the exception of the steatoerit acid. GE was studied in animals undergoing 24 hour fasting, receiving water ad libitum; LTM was administered by standard technique, using the volume of 2mVg the animal's weight. For the statistical analysis, the non parametric Mann-Whitney (K=2) and Kruskal- Wallis (K:::: 3) test was used, having established that the value of a.=0.05. As there was a significant difference in the Kruskal -Wallis test, the multiple comparisons test was applied in the differentiation between the pairs (a. = 0.02). The results of phase I demonstrated the efficacy of the bile duet ligature, as to the aspects analyzed. The following facts stand out: 1- no significant differences were observed in the levels of serie amylase when groups were compared; 2- the animals with bile duet ligature presented significantly greater values of steatocrit (median = 58.5%) in relation to the simulation group (median = 8%). The results of phase II demonstrate significantly lower weight gain in the animais with bile duct ligature, as well as significantly greater values of humid and dry weight, and liquid content of the liver of these in relation to the simulated animais. The results of the biochemical determinations performed in this phase did not differ from those obtained in phase I. The emptying of the saline LTM was not influenced by the bile duct ligature (median of GR = 38.5%) in relation to the control group (median of GR = 36.3%) and simulation group (median ofGR = 36.9%). As to the LTM of mayonnaise at 3 and 6%, a significantly lower GR was observed in the groups with ligature (median of GR of MG3 = 30.4% and MG6 = 35.4%), when compared to the respective simulation groups (median of GR ofthe MG3 = 38.6% and of MG6 = 47.3%). On the other hand, the GR of LTM of glucose at 5% did not show significant difference in the animais with bile duct ligature (median of GR of the GG5 ",;45.2%), in relation to the sham (median GR of the GG5 = 41,5%), however, in the GR of the LTM glucose at 10%, significantly greater values )Vere observed in the animais with bile duct ligature (median of GR of GGI0 = 66.8%), when compared to the respective simulation groups (median ofGR ofGGlO = 53.6%). Thus, the conclusion is that in rats the absence of biliary flux to the small intestine increased the GE of fats and retarded the GE o(glucose to 10%, when macronutrients were administered in liquid meal form / Doutorado / Pediatria / Doutor em Saude da Criança e do Adolescente
93

Efeito da eritromicina, administrada por via oral, no tratamento de crianças com constipação intestinal cronica funcional

Brandão, Maria Angela Bellomo, 1967- 02 June 2002 (has links)
Orientador : Elizete Aparecida Lomazi da Costa Pinto / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-01T09:25:18Z (GMT). No. of bitstreams: 1 Brandao_MariaAngelaBellomo_M.pdf: 3286270 bytes, checksum: 4777c3db43f91503eb2fff1b3d1f88d6 (MD5) Previous issue date: 2002 / Resumo: A constipação intestinal funcional (CIF) é um sintoma freqüente na infância e os escapes fecais caracterizam quadros graves, que podem estar associados a um distúrbio de motilidade gastrintestinal. Nesses casos, a utilização de um agente pró-cinético poderia ser benéfica. O presente estudo teve por objetivo avaliar a resposta terapêutica ao uso da eritromicina, como coadjuvante no tratamento de 14 crianças com CIF grave. O estudo foi do tipo duplo-cego, placebo controlado, "crossover". A dose de 20rnglkg/dia, dividida em 4 tomadas, foi administrada por I mês a um grupo de 6 crianças (GRUPO 1) que, no mês seguinte, receberam o placebo no mesmo esquema de administração. Um outro grupo (GRUPO 2), composto por 8 crianças, recebeu o princípio ativo após I mês de uso do placebo. O controle clínico do efeito terapêutico da droga foi feito utilizando-se um sistema de pontuação onde a maior gravidade correspondia ao maior valor e os parâmetros utilizados na análise foram: freqüência das evacuações, presença de dor ou dificuldade às evacuações, presença de impactação fecaL presença de escapes fecais, consistência das fezes e necessidade de laxativos. A pontuação foi controlada quinzenalmente a partir da introdução do paciente no estudo. A análise do efeito da droga demonstrou que, independente do esquema utilizado, os valores da pontuação nos grupos foram sempre significativamente inferiores, nos períodos de ingestão de eritromicina. Concluiu-se que a adição da eritromicina ao esquema terapêutico de pacientes com CIF grave colaborou na meJhora clínica / Abstract: Functional constipation is a common problem in pediatric practice. Clinical presentation varies among patients and so does treatment. Abdominal mass and soiling indicate severe constipation. Although the pathophysiology is unclear, probably constipated patients present an intestinal motility disturbance, thus, prokinetics agents could be use fui for whose one with severe disease. OBJECTIVE: This study aims to evaluate the value of erythromycin, a prokinetics agent, in addition to the usual therapy in constipated children. METHODS: The study has included fourteen school-aged constipated children who had palpable abdominal mass and soiling. Methodology was based in double blind, placebo-controlled crossover study. Six children have ingested erythromycin, 20rnglKg, orally, divided in 4 doses, during a month, and placebo in the following month (GROUP 1). Eight children have ingested placebo in the first month and erythromycin in the next one (GROUP 2). A score was elaborated to evaluate the clinical evolution. Such score included stool :fTequency, painful defecation, palpable fecal mass, soiling, fecal consistence and use of laxatives. The score was obtained in 0,15, 30, 45 and 60 days after the patients' inc1usion in the study. RESULTS: There was no statistical difference between groups considering in initial score value, sex, age and symptoms duration (Mann- Whitney test p>0,05). Scores values for c1inical evolution was evaluated by statistical analysis ANOV A and they have pointed a significant improve during erythromycin ingestion. We conc1ude that erythromycin inc1usion in the treatment was benefic and presented no side effects. Erythromycin might act in the intestinal motility of children with severe functional constipation / Mestrado / Pediatria / Mestre em Saude da Criança e do Adolescente
94

Estudio de validación diagnóstica de la escala de Glasgow-Blatchford para la predicción de mortalidad en pacientes con hemorragia digestiva alta en un hospital de Lima, Perú (junio 2012-diciembre 2013)

Cassana Abad, Carla Alessandra, Scialom, Silvia, Segura, Eddy R., Chacaltana, Alfonso 07 1900 (has links)
Antecedentes y propósito del estudio: la hemorragia digestiva alta es una causa importante de ingreso hospitalario y constituye la principal emergencia gastroenterológica, con una tasa de mortalidad de hasta el 14%. En el Perú no existen estudios sobre el uso de la escala de Glasgow-Blatchford para predecir mortalidad por hemorragia digestiva alta. El objetivo de este estudio es realizar la validación externa de la escala de Glasgow-Blatchford y establecer su mejor punto de corte para predecir mortalidad por hemorragia digestiva alta en un hospital de Lima, Perú. Métodos: estudio de validación diagnóstica, analítico, longitudinal, de tipo retrospectivo, con datos de pacientes con diagnóstico clínico y endoscópico de hemorragia digestiva alta atendidos en la Unidad de Hemorragia Digestiva del Hospital Nacional Edgardo Rebagliati Martins, entre junio de 2012 y diciembre de 2013. Calculamos el área bajo la curva ROC (receiver operating characteristic) de la escala de Glasgow-Blatchford para predecir mortalidad, con un intervalo de confianza al 95%. Resultados: un total de 339 registros fueron analizados. El 57,5% fueron varones y la edad media (desviación estándar) fue de 67,0 (15,7) años. La mediana de la escala de Glasgow-Blatchford obtenida en la población fue de 12. El análisis ROC para mortalidad dio un área bajo la curva de 0,59 (IC95% 0,5-0,7). Se estratificó por tipo de hemorragia digestiva alta, obteniendo un área bajo la curva de 0,66 (IC95% 0,53-0,78) para el tipo no variceal. Conclusiones: en la población estudiada, la escala de Glasgow-Blatchford no posee una validez diagnóstica adecuada para predecir mortalidad.
95

Development of new targeted prebiotic approaches for optimising the human intestinal microbiota

Chung, Wing Sun Faith January 2016 (has links)
No description available.
96

Factores asociados a mal pronóstico en pacientes con sangrado digestivo bajo en un hospital público

Carvallo Michelena, Alvaro, Rojas Domínguez, Jorge Luis 03 February 2016 (has links)
Introducción: El sangrado digestivo bajo (SDB) es una entidad cuyas tasas de complicaciones y mortalidad se han incrementado en las últimas décadas. Si bien se han identificado algunos factores relacionados a mal pronóstico, aún quedan variables por evaluar. Objetivo: Identificar factores de mal pronóstico en pacientes que presentaron SDB en el Hospital Nacional Edgardo Rebagliati Martins de Lima, Perú. Materiales y métodos: Se realizó un estudio observacional analítico de tipo cohorte retrospectivo. Se realizó un censo de todos los pacientes que presentaron SDB agudo entre Enero 2010 y Diciembre 2013. Las variables principales a evaluar fueron frecuencia cardiaca ≥ 100/min, presión arterial sistólica < 100 mmHg y hematocrito bajo (≤ 35%) al ingreso. Se definió mal pronóstico como cualquiera de los siguientes criterios: muerte durante la hospitalización, sangrado que requiera transfusión de ≥ 4 unidades de sangre, reingreso dentro del primer mes, o necesidad de cirugía de hemostasia. Resultados: Se incluyó un total de 341 pacientes con SDB, de los cuales el 27% tuvo mal pronóstico y 2% fallecieron. Se encontró como variables asociadas a mal pronóstico: frecuencia cardiaca ≥ 100/min al ingreso (RR: 1,75 IC 95% 1,23-2,50), presión arterial sistólica < 100 mmHg al ingreso (RR: 2,18 IC 95% 1,49-3,19), hematocrito ≤ 35% al ingreso (RR: 1,98 IC 95% 1,23-3,18) y sangrado de origen no determinado (RR: 2,74 IC 95% 1,73-4,36). Conclusiones: Frecuencia cardiaca elevada al ingreso, hipotensión sistólica al ingreso, hematocrito bajo al ingreso y presentar un sangrado en el cual no se encuentra el punto de origen son factores que incrementan el riesgo de presentar mal pronóstico, por lo que se recomienda un monitoreo más estricto en estos pacientes. / Background: Lower gastrointestinal bleeding (LGIB) is an event that has shown an increase in complications and mortality rates in the last decades. Although some factors associated with poor outcome have been identified, there are several yet to be evaluated. Objective: To identify risk factors for poor outcome in patients with LGIB in the Hospital Nacional Edgardo Rebagliati Martins of Lima, Peru. Material and methods: A prospective analytic observational cohort study was made, and a census was conducted with all patients with acute LGIB between January 2010 and December 2013. The main variables were heart rate ≥ 100/min, systolic blood pressure < 100 mmHg and low hematocrit (≤ 35%) at admission. Poor outcome was defined as any of the following: death during hospital stay, bleeding requiring transfusion of ≥ 4 blood packs, readmission within one month of hospital discharge, or the need for hemostatic surgery. Results: A total of 341 patients with LGIB were included, of which 27% developed poor outcome and 2% died. Variables found to be statistically related to poor outcome were: heart rate ≥ 100/min at admission (RR: 1,75 IC 95% 1,23-2,50), systolic blood pressure < 100 mmHg at admission (RR: 2,18 IC 95% 1,49-3,19), hematocrit ≤ 35% at admission (RR: 1,98 IC 95% 1,23-3,18) and LGIB of unknown origin (RR: 2,74 IC 95% 1,73-4,36). Conclusions: Elevated heart rate at admission, systolic hypotension at admission, low hematocrit at admission and having a LGIB of unknown origin are factors that increase the risk of developing poor outcome, and these patients should be monitored closely due to their higher risk of complications.
97

Molecular detection and characterization of verocytotoxigenic E. coli from human clinical specimens in Northern Ireland

Watabe, M. January 2002 (has links)
No description available.
98

Absorption of amino acids and B vitamins from the rumen

Smith, Frederick Dabell January 1959 (has links)
The purpose of this investigation was to provide direct experimental evidence for or against the suggestion that amino acids and B vitamins are among the nutrients absorbed from the rumen of the ruminant. The investigation was subdivided into two parts: (1) six ruminal fistula experiments and (2) nine blood-sampling experiments. The goat (Capra) was the experimental animal. In the ruminal fistula experiments, solutions of amino acids, B vitamins, and usually propionic acid were added to an empty rumen for 120 or 150 minutes. Propionic acid, a substance known to be absorbed from the rumen, was included in most of the solutions to provide a positive control for ruminal absorption. In addition, in all but the first two experiments, polyethylene glycol was added to the solutions in order to provide a marker substance for differential water movement into or out of the rumen. Controls for the experiments included the taking of a sample from the solution in the rumen at zero time and incubating the sample for the duration of the experiment in a water-bath held at 37°C. The ruminal and control solutions were sampled at periodic intervals during the experiment. The results demonstrated not only marked decreases in the concentrations of propionic acid in the ruminal solutions but also, in most cases, marked decreases in the concentrations of the amino acids and the B vitamins assayed: tryptophan, methionine, tyrosine, glycine, lysine, riboflavin, nicotinic acid, and pantothenic acid. In contrast, the concentrations of these constituents in the control solutions usually demonstrated either no decrease or a small increase. In the first three blood-sampling experiments, the concentrations of amino acids and nicotinic acid in the plasma draining the rumen were compared with the concentrations in the peripheral plasma. The results demonstrated that seldom were the concentrations of an amino acid or nicotinic acid higher in the plasma draining the rumen than in the peripheral plasma. The results did suggest, however, that there had been slight increases in the plasma concentrations of the amino acids with time. Accordingly, the next six blood-sampling experiments were designed to determine if time-related increases in the blood concentration of alpha amino nitrogen occurred after the addition of amino acids to the rumen. Blood samples were removed periodically from anesthetized goats, both before and after the addition of a solution of amino acids to an empty rumen. The results demonstrated time-related increases in the blood concentrations of alpha amino nitrogen. These results and those obtained for the ruminal fistula experiments are interpreted as supporting the suggestion that amino acids and B vitamins are absorbed from the rumen. In the General Discussion, a preliminary attempt is made to answer three questions: 1) What is the manner of the passage of amino acids and B vitamins across the ruminal epithelium? 2) Does this passage of amino acids and B vitamins occur under normal feeding conditions? 3) How does this passage of amino acids and B vitamins across the ruminal epithelium fit into the scheme pictured for the metabolism and final fate of these compounds in the ruminal contents? As a part of the attempt to answer the first question, literature reviews are presented on the manner of absorption of amino acids and B vitamins in the small intestine, kidney, placenta, and other tissues. Then, after a literature review on the manner of absorption of substances other than amino acids and B vitamins from the rumen, the data of the present investigation are examined for evidence as to the manner of absorption of amino acids and B vitamins from the rumen. The examination led to the following statement: the movement of amino acids across the ruminal wall of the goat is determined by a summation of the effects of chemical, electrical, and possibly metabolic potentials. Unfortunately, other than to suggest that the process of simple diffusion is involved, the nature of the data for the B vitamins was not such as to yield much information on their manner of absorption. In the attempt to answer the second question, the fulfillment or non-fulfillment of the following conditions is considered: (1) the demonstration of the presence of amino acids and B vitamins in the rumen, (2) the demonstration of the relation of the concentrations of individual amino acids and B vitamins in the ruminal liquor to their concentrations in the blood plasma, and (3) the demonstration of the absorption of individual amino acids and B vitamins from an ingesta-filled rumen. Although fulfillment of the third condition was not obtained, fulfillment of the first two conditions was obtained and led to the statement that a strong possibility exists that the absorption of amino acids and B vitamins occurs from the rumen under normal feeding conditions. In the attempt to answer the third question, a number of factors are discussed in turn: (1) the environmental conditions of the rumen, (2) the influence of the diet on the composition of the population of microorganisms in the rumen, (3) the physical and chemical nature of the dietary constituents, (4) the relative stability of amino acids and B vitamins in the ruminal ingesta, and (5) the physiological state of the animal. Evidence is presented to demonstrate that each of these factors probably exerts an important influence on the content of amino acids and B vitamins in the rumen. It is suggested that, when the interaction of the many factors is such as to produce higher concentrations of amino acids and B vitamins in the rumen, the proportions of amino acids and B vitamins that pass from the rumen by absorption through its wall will be an important pathway for these nutrients. To conclude the General Discussion, the possible nutritional implications of the absorption of amino acids and B vitamins from the rumen are considered. One suggestion made is that a general absorption of nutrients from the rumen would permit the simultaneous arrival at the liver, or elsewhere in the body, of volatile fatty acids, amino acids, B vitamins, and inorganic ions. This should promote more efficient utilization of each of the nutrients. Another suggestion made is that ruminal absorption of amino acids and B vitamins places the host ruminant in a better competitive position relative to its contained microbial population in the competition for nutrients. Finally, a suggestion is made that the action of the ruminal wall in absorbing amino acids helps to explain the results that have been obtained for certain nitrogen retention experiments in ruminants. / Science, Faculty of / Zoology, Department of / Graduate
99

Viabilidade de implantação e sobrevivência de lactobacilos no trato intestinal de humanos adultos / iability of implantation and survival of lactobacilli in the adult human intestinal tract

Gersislei Antonia Salado 26 November 1990 (has links)
Com o objetivo de estudar a viabilidade de implantação e a sobrevivência além da ação dos lactobacilos no trato intestinal de humanos adultos, foram realizados dois tipos de tratamento, com duração de 45 dias ininterruptos. Os indivíduos foram divididos em dois grupos designados grupo A e grupo B. O grupo A consumiu iogurte natural e o grupo B consumiu iogurte natural e leite “in natura” tipo C. Para avaliar a ação dos lactobacilos sobre a flora intestinal e sua permanência no trato digestivo, foram efetuadas análises microbiológicas periódicas das fezes dos indivíduos. Os resultados obtidos permitem concluir que os lactobacilos podem permanecer no intestino mesmo após a interrupção da ingestão de iogurte, embora em números inferiores aos encontrados durante o período experimental, e que somente com ingestão diária desse produto será possível sua persistência exercendo efeito controlador sobre a flora intestinal. / With the objective of studying the possibility of the implantation and subsequent survival - as well as the action - of lactobacilli in the adult human intestinal tract, two types of treatment were administered during 45 uninterrupted days. The individual were divided into two groups, designated as group A and group B. Group A consumed natural yogurt, while group B consumed natural yogurt plus ordinary milk (called type C, in Brazil). In order to evaluate the effect of the lactobacilli on the intestinal flora and the permanence of such in the digestive tract, microbiological analyses were effected upon the feces of the same individuals. The results obtained permit to conclud that the lactobacilli may remain in the intestine even after interrupting the yogurt intake, though in smaller numbers than previously encontered during the experimental period, and that only with the daily intake of the said product is any permanence made possible, as well as the exercise of any controlling effect upon the intestinal flora.
100

Determination of aluminum concentration in serum and tissue : factors affecting the gastrointestinal absorption of aluminum /

Thornton, David James January 1986 (has links)
No description available.

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