• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4
  • 2
  • 1
  • 1
  • Tagged with
  • 14
  • 4
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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.
11

Efeito de IgG e IGF-I das primeiras refeições lácteas sobre a flutuação sérica e características do epitélio intestinal em bezerros recém-nascidos / Effects of IgG and IGF-I of the first milky meals on the serum fluctuation and characteristics of the intestinal epithelium in the newborn calves

Kindlein, Liris 28 April 2006 (has links)
O objetivo deste trabalho foi estudar os efeitos de diferentes manejos de fornecimento de colostro sobre a aquisição sérica de imunoglobulina G (IgG) e do fator de crescimento semelhante à insulina-I (IGF-I), bem como as modificações morfológicas e morfométricas do epitélio intestinal em bezerros recém-nascidos. Foi utilizado o fornecimento prolongado de colostros de diferentes concentrações, incluindo colostro enriquecido com colostro liofilizado e acompanhada a flutuação dos níveis séricos de IgG e proteína total (PT) nas primeiras 72 horas de vida, com diferentes condições iniciais de aquisição de imunidade passiva. Também foi estudada a relação da massa de IGF-I ingerida com possíveis alterações na morfologia entérica e nos enterócitos. Oitenta e dois bezerros da raça Holandesa receberam, ao nascimento, colostro com concentrações variáveis de IgG. Com base na avaliação sérica das imunoglobulinas realizada na décima hora de vida, os animais foram distribuídos em dois grupos, IgG sérica abaixo ou acima de 12 mg mL-1. Cada grupo foi submetido à três tratamentos de acordo com a refeição fornecida às 12 horas de vida, colostro baixo (concentração de IgG inferior à 30 mg mL-1), colostro alto (superior à 100 mg mL-1) ou colostro enriquecido de colostro liofilizado (superior à 120 mg mL-1). Às 0, 10-12, 24, 36, 48 e 72 horas de vida foi coletado sangue dos bezerros para análise de IgG, PT e IGF-I, e amostras do duodeno; jejuno proximal, médio e distal; e íleo para análise histomorfológica. Para análise das variáveis séricas, considerou-se um delineamento experimental inteiramente casualizado com medidas repetidas no tempo. Para análise das variáveis morfométricas dos segmentos intestinais foi considerado um arranjo fatorial 3X3+1, correspondendo à massa total de IGF-I fornecida via colostro, às idades de abate (10, 24-36 e 72 horas de vida) e o grupo controle (nascimento). O fornecimento prolongado de colostro enriquecido em bezerros com alta aquisição inicial não apresentou efeito significativo sobre a flutuação sérica de IgG. A ingestão de sólidos totais acima de 150 g determinou menores valores de IgG sérica. Os animais com baixa aquisição inicial mostraram uma maior eficiência de absorção de anticorpos comparados aos com alta aquisição inicial. A massa de IGF-I consumida não influenciou os níveis séricos desta variável, porém influenciou o comportamento da densidade dos vilos ileais e a altura dos microvilos do duodeno, jejuno proximal e médio. Os valores do volume parcial da mucosa absortiva do nascimento às 10 horas de vida apresentaram diferenças significativas. O fornecimento prolongado de colostro de alta concentração de imunoglobulinas e IGF-I influenciou a morfologia da mucosa entérica. / The objective of this study was to evaluate the effects of different colostrum supply on the serum immunoglobulin G (IgG) acquisition and the insulin-like growth factor-I (IGF-I), as well as the morphologic and morphometric modifications of the intestinal epithelium in the newborn calves. The prolonged supply of colostrum with different concentrations was used, including colostrum enriched with lyophilized colostrum, and was accompanied the fluctuation of serum IgG and total protein (TP) of calves in the first 72 hours of life, according to initial passive immunity acquisition. It was also studied the relation of IGF-I mass ingested with possible alterations in the intestinal morphology and enterocytes. Eighty two Holstein calves received at birth colostrum with different concentrations of IgG. Based on serum immunoglobulins evaluation at ten hour of life, the animals were distributed in two groups, serum IgG below or above 12 mg mL-1. Each group received three treatments in agreement with the meal supplied at 12 hours of life, low colostrum (IgG inferior to 30 mg mL-1), high colostrum (superior to 100 mg mL-1) or enriched with lyophilized colostrum (superior to 120 mg mL-1). At 0, 10-12, 24, 36, 48 and 72 hours of life blood was collected from calves for IgG, TP and IGF-I analysis, and samples from duodenum; proximal, middle and distal jejunum, and ileum for histomorphologic analysis. A completely randomized design was used with the serum variables analyzed as repeated measures on time. The morphometric variables of the intestinal segments were considered a factorial arrangement 3X3+1, corresponding to the total mass of IGF-I supplied in colostrum and the slaughter ages (10, 24-36 and 72 hours of life) plus the control group (birth). The prolonged supply of enriched colostrum in calves with high initial acquisition did not present significant effects on the serum IgG fluctuation. The ingestion of total solids above 150 g determined lower values of serum IgG. The animals with low initial acquisition showed better absorption efficiency of antibodies compared to high initial acquisition. The mass of IGF-I consumed did not influence the serum levels of this variable; however it influenced the behavior of the density of the ileum villi and the height of the microvillus from duodenum, proximal and middle jejunum. The values of the partial volume of the absorptive mucous membrane from birth to 10 hours of life presented significant differences. The prolonged supply of colostrum with high immunoglobulins and IGF-I concentrations influenced the morphology of the intestinal mucosa.
12

Efeito de IgG e IGF-I das primeiras refeições lácteas sobre a flutuação sérica e características do epitélio intestinal em bezerros recém-nascidos / Effects of IgG and IGF-I of the first milky meals on the serum fluctuation and characteristics of the intestinal epithelium in the newborn calves

Liris Kindlein 28 April 2006 (has links)
O objetivo deste trabalho foi estudar os efeitos de diferentes manejos de fornecimento de colostro sobre a aquisição sérica de imunoglobulina G (IgG) e do fator de crescimento semelhante à insulina-I (IGF-I), bem como as modificações morfológicas e morfométricas do epitélio intestinal em bezerros recém-nascidos. Foi utilizado o fornecimento prolongado de colostros de diferentes concentrações, incluindo colostro enriquecido com colostro liofilizado e acompanhada a flutuação dos níveis séricos de IgG e proteína total (PT) nas primeiras 72 horas de vida, com diferentes condições iniciais de aquisição de imunidade passiva. Também foi estudada a relação da massa de IGF-I ingerida com possíveis alterações na morfologia entérica e nos enterócitos. Oitenta e dois bezerros da raça Holandesa receberam, ao nascimento, colostro com concentrações variáveis de IgG. Com base na avaliação sérica das imunoglobulinas realizada na décima hora de vida, os animais foram distribuídos em dois grupos, IgG sérica abaixo ou acima de 12 mg mL-1. Cada grupo foi submetido à três tratamentos de acordo com a refeição fornecida às 12 horas de vida, colostro baixo (concentração de IgG inferior à 30 mg mL-1), colostro alto (superior à 100 mg mL-1) ou colostro enriquecido de colostro liofilizado (superior à 120 mg mL-1). Às 0, 10-12, 24, 36, 48 e 72 horas de vida foi coletado sangue dos bezerros para análise de IgG, PT e IGF-I, e amostras do duodeno; jejuno proximal, médio e distal; e íleo para análise histomorfológica. Para análise das variáveis séricas, considerou-se um delineamento experimental inteiramente casualizado com medidas repetidas no tempo. Para análise das variáveis morfométricas dos segmentos intestinais foi considerado um arranjo fatorial 3X3+1, correspondendo à massa total de IGF-I fornecida via colostro, às idades de abate (10, 24-36 e 72 horas de vida) e o grupo controle (nascimento). O fornecimento prolongado de colostro enriquecido em bezerros com alta aquisição inicial não apresentou efeito significativo sobre a flutuação sérica de IgG. A ingestão de sólidos totais acima de 150 g determinou menores valores de IgG sérica. Os animais com baixa aquisição inicial mostraram uma maior eficiência de absorção de anticorpos comparados aos com alta aquisição inicial. A massa de IGF-I consumida não influenciou os níveis séricos desta variável, porém influenciou o comportamento da densidade dos vilos ileais e a altura dos microvilos do duodeno, jejuno proximal e médio. Os valores do volume parcial da mucosa absortiva do nascimento às 10 horas de vida apresentaram diferenças significativas. O fornecimento prolongado de colostro de alta concentração de imunoglobulinas e IGF-I influenciou a morfologia da mucosa entérica. / The objective of this study was to evaluate the effects of different colostrum supply on the serum immunoglobulin G (IgG) acquisition and the insulin-like growth factor-I (IGF-I), as well as the morphologic and morphometric modifications of the intestinal epithelium in the newborn calves. The prolonged supply of colostrum with different concentrations was used, including colostrum enriched with lyophilized colostrum, and was accompanied the fluctuation of serum IgG and total protein (TP) of calves in the first 72 hours of life, according to initial passive immunity acquisition. It was also studied the relation of IGF-I mass ingested with possible alterations in the intestinal morphology and enterocytes. Eighty two Holstein calves received at birth colostrum with different concentrations of IgG. Based on serum immunoglobulins evaluation at ten hour of life, the animals were distributed in two groups, serum IgG below or above 12 mg mL-1. Each group received three treatments in agreement with the meal supplied at 12 hours of life, low colostrum (IgG inferior to 30 mg mL-1), high colostrum (superior to 100 mg mL-1) or enriched with lyophilized colostrum (superior to 120 mg mL-1). At 0, 10-12, 24, 36, 48 and 72 hours of life blood was collected from calves for IgG, TP and IGF-I analysis, and samples from duodenum; proximal, middle and distal jejunum, and ileum for histomorphologic analysis. A completely randomized design was used with the serum variables analyzed as repeated measures on time. The morphometric variables of the intestinal segments were considered a factorial arrangement 3X3+1, corresponding to the total mass of IGF-I supplied in colostrum and the slaughter ages (10, 24-36 and 72 hours of life) plus the control group (birth). The prolonged supply of enriched colostrum in calves with high initial acquisition did not present significant effects on the serum IgG fluctuation. The ingestion of total solids above 150 g determined lower values of serum IgG. The animals with low initial acquisition showed better absorption efficiency of antibodies compared to high initial acquisition. The mass of IGF-I consumed did not influence the serum levels of this variable; however it influenced the behavior of the density of the ileum villi and the height of the microvillus from duodenum, proximal and middle jejunum. The values of the partial volume of the absorptive mucous membrane from birth to 10 hours of life presented significant differences. The prolonged supply of colostrum with high immunoglobulins and IGF-I concentrations influenced the morphology of the intestinal mucosa.
13

Butyrate Protects Porcine Colon Epithelium from Hypoxia-Induced Damage on a Functional Level

Dengler, Franziska, Kraetzig, Anika, Gäbel, Gotthold 05 May 2023 (has links)
The large intestinal epithelium is confronted with the necessity to adapt quickly to varying levels of oxygenation. In contrast to other tissues, it meets this requirement successfully and remains unharmed during (limited) hypoxic periods. The large intestine is also the site of bacterial fermentation producing short-chain fatty acids (SCFA). Amongst these SCFA, butyrate has been reported to ameliorate many pathological conditions. Thus, we hypothesized that butyrate protects the colonocytes from hypoxic damage. We used isolated porcine colon epithelium mounted in Ussing chambers, incubated it with or without butyrate and simulated hypoxia by changing the gassing regime to test this hypothesis. We found an increase in transepithelial conductance and a decrease in short-circuit current across the epithelia when simulating hypoxia for more than 30 min. Incubation with 50 mM butyrate significantly ameliorated these changes to the epithelial integrity. In order to characterize the protective mechanism, we compared the effects of butyrate to those of iso-butyrate and propionate. These two SCFAs exerted similar effects to butyrate. Therefore, we propose that the protective effect of butyrate on colon epithelium under hypoxia is not (only) based on its nutritive function, but rather on the intracellular signaling effects of SCFA.
14

Bovint serum albumin påverkar överlevnad och Aβ-nivåer i Alzheimers sjuka Drosophila flugor. : Bovine serum albumin affects survival and Aβ-levels in Alzheimer's diseased Drosophila flies.

Tani, Milena January 2024 (has links)
Alzheimer's disease (AD) was first described more than 100 years ago and is today the most common cause of dementia. It is one of the progressive neurodegenerative diseases that affect 47 million people around the world between the ages of 60 and 90. One of the contributing factors to AD is extracellular amyloid – β (Aβ) plaques that form as a result of protein aggregation. These Aβ proteins are neurotoxic, leading to degeneration of brain neurons and loss of cognitive abilities. Because AD largely affects society, researchers are constantly working to find a cure, which currently does not exist. The purpose of this study was to use Drosophila melanogaster as a living organism model for the expression of two types of Aβ proteins related to AD, Arctic (Glu22Gly) and TandemAβ, and to study the survival of these AD flies when Bovine serum albumin (BSA) was added to the fly food. The hypothesis was that BSA would be effective in slowing down and/or preventing formation of toxic Aβ-aggregates. The focus was therefore to investigate whether the AD flies would live longer if they were allowed to eat Bovine serum albumin and whether the soluble/insoluble Aβ levels in these flies would decrease in comparison to the control AD flies that were not allowed to eat BSA. The effect of BSA on toxicity was evaluated using survival assay on male flies and the levels of soluble/insoluble Aβ were evaluated using Meso Scale Discovery (MSD) on female flies. In both experiments, the following six groups of flies were examined: myow1118 ± BSA; myoArctic ± BSA; myoTandemAβ ± BSA. Conclusions from the studies are that the survival of AD flies could not be extended by adding 0.61 mM BSA to the food, rather the data showed a weak but significant toxic effect in the presence of BSA in the AD flies. However, MSD data showed a reduction of insoluble Aβ aggregates and an equilibrium shift from insoluble Aβ aggregates to soluble Aβ aggregates in the presence of BSA in the AD flies. Equilibrium shifts were particularly detectable in Myo-TandemAβ flies fed with BSA. In Myo-Arctic flies fed with BSA only reduction of insoluble Aβ could be detected. This shows that it is not the amount of Aβ aggregates that is decisive for toxicity, but rather the presence of specific aggregates that have toxic properties. If BSA shows good results in further studies, it could be used in the future to improve AD symptoms in patients.

Page generated in 0.0649 seconds